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Sample records for pyrene

  1. Blue-emitting pyrene-based aggregates.

    Science.gov (United States)

    Valera, Jorge S; Calbo, Joaquín; Gómez, Rafael; Ortí, Enrique; Sánchez, Luis

    2015-06-25

    The supramolecular polymerization of pyrene imidazoles 1 and 2, governed by H-bonding and C-H···π interactions, yields aggregates showing the characteristic bluish emission pattern of pyrene-based monomers.

  2. Effect of rhizodeposition on pyrene bioaccessibility and microbial structure in pyrene and pyrene-lead polluted soil.

    Science.gov (United States)

    Wei, Jing; Liu, Xiaoyan; Wang, Qian; Wang, Chuanhua; Chen, Xueping; Li, Hongbing

    2014-02-01

    Phytoremediation for PAH hydrocarbons has been widely studied, but few focus on the influence of rhizodeposition on their bioaccessibility during the process. This literature revealed the effect of celery (Apium graveolens) rhizodeposition on pyrene fractionation and bioaccessibility in simulated pyrene and pyrene-lead contaminated microcosms. A sequential extraction methodology was used to quantify different morphological fractions of pyrene in the soil, and phospholipid fatty acid (PLFA) pattern to monitor shifts in microbial populations. Bioaccessible pyrene accounted for the largest proportion of the total removal. Biodegradation of both bioaccessible and associated pyrene fractions was enhanced by celery rhizodeposition in pyrene spiked soils. However, rhizodeposition promoted the removal of bioaccessible rather than associated fractions in pyrene-lead spiked soils. In contrast, the bound fraction increased over time in pyrene spiked soils without amendment, but kept relatively stable in amended microcosms. It was found that rhizodeposition facilitated the reproduction of all the subgroups of soil microorganisms through PLFA analysis. Although all the subgroups contributed to the removal of bioaccessible pyrene, only abundances of unsaturated and cyclic fatty acids were positively correlated with the removal of associated pyrene. These findings provide meaningful insights into the microecological mechanisms involved in the phytoremediation of PAH polluted sites.

  3. Synthesis of dehydrobenzoannulenes with pyrene core

    Indian Academy of Sciences (India)

    Antony Joseph; Gandikota Venkataramana; Sethuraman Sankararaman

    2012-05-01

    Synthesis of dehydrobenzoannulenes (DBAs) with pyrene core from 1,8-diethynylpyrene and 1,3,6,8-tetraethynylpyrene as building blocks is reported. A sequence involving Sonogashira coupling, Corey- Fuchs reaction and oxidative coupling (Eglinton coupling) is used for the synthesis of pyrene-based dehydrobenzoannulenes. Due to the presence of pyrenechromophore these DBAs and their precursors are highly fluorescent and emit in the visible region, due to extended conjugation of the acetylenic units with the pyrene core.

  4. Fluorescence emission of pyrene in surfactant solutions.

    Science.gov (United States)

    Piñeiro, Lucas; Novo, Mercedes; Al-Soufi, Wajih

    2015-01-01

    The systematic description of the complex photophysical behaviour of pyrene in surfactant solutions in combination with a quantitative model for the surfactant concentrations reproduces with high accuracy the steady-state and the time resolved fluorescence intensity of pyrene in surfactant solutions near the cmc, both in the monomer and in the excimer emission bands. We present concise model equations that can be used for the analysis of the pyrene fluorescence intensity in order to estimate fundamental parameters of the pyrene-surfactant system, such as the binding equilibrium constant K of pyrene to a given surfactant micelle, the rate constant of excimer formation in micelles, and the equilibrium constant of pyrene-surfactant quenching. The values of the binding equilibrium constant K(TX100)=3300·10³ M⁻¹ and K(SDS)=190·10³ M⁻¹ for Triton X-100 (TX100) and SDS micelles, respectively, show that the partition of pyrene between bulk water and micelles cannot be ignored, even at relatively high surfactant concentrations above the cmc. We apply the model to the determination of the cmc from the pyrene fluorescence intensity, especially from the intensity ratio at two vibronic bands in the monomer emission or from the ratio of excimer to monomer emission intensity. We relate the finite width of the transition region below and above the cmc with the observed changes in the pyrene fluorescence in this region.

  5. Pyrene effects on rhizoplane bacterial communities.

    Science.gov (United States)

    Balcom, Ian N; Crowley, David E

    2009-09-01

    Certain plant species promote biodegradation of polycyclic aromatic hydrocarbons (PAHs), but few studies have examined the microbial populations that are associated with the rhizoplane of these plants. In this study, the bacterial composition of the rhizoplane were characterized for four plant species during in soils with different histories of exposure to PAH and in the presence or absence of a pyrene spike at 100 mg kg(-1) pyrene. Three of the plant species including Andropogon gerrardii, Panicum coloratum and Melilotus officinalis were known to stimulate PAH degradation. Wheat (Triticum aestivum) was used as a reference species. Results showed that after 90 days, approximately 45% of the pyrene spike disappeared from soil without plants. In contrast, cultivation of plants resulted in 95% disappearance of pyrene. There were no significant differences in the extent of pyrene disappearance for different plants. In all cases, 16S rRNA gene profiles of the rhizoplane were less complex in the pyrene-spiked soils, suggesting that richness and evenness of the predominant bacteria were reduced. Our results show that pyrene contamination results in significant shifts in the composition of rhizosphere bacterial communities that are still further influenced by the plant species and prior exposure history to PAH contamination.

  6. Biosorption and biodegradation of pyrene by Brevibacillus brevis and cellular responses to pyrene treatment.

    Science.gov (United States)

    Liao, Liping; Chen, Shuona; Peng, Hui; Yin, Hua; Ye, Jinshao; Liu, Zehua; Dang, Zhi; Liu, Zhichen

    2015-05-01

    Biodegradation has been proposed as an effective approach to remove pyrene, however, the information regarding cellular responses to pyrene treatment is limited thus far. In this study, the biodegradation and biosorption of pyrene by Brevibacillus brevis, along with cellular responses caused by pollutant were investigated by means of flow cytometry assay and scanning electron microscopy. The experimental results showed that pyrene was initially adsorbed by B. brevis and subsequently transported and intracellularly degraded. During this process, pyrene removal was primarily dependent on biodegradation. Cell invagination and cell surface corrugation occurred due to pyrene exposure. Nevertheless, cell regrowth after 96h treatment was observed, and the proportion of necrotic cell was only 2.8% after pyrene exposure for 120h, confirming that B. brevis could utilize pyrene as a sole carbon source for growth. The removal and biodegradation amount of pyrene (1mg/L) at 168h were 0.75 and 0.69mg/L, respectively, and the biosorption amount by inactivated cells was 0.41mg/L at this time.

  7. Pyrene-indole exciplexes as positive photocatalysts.

    Science.gov (United States)

    Cuquerella, M Consuelo; El Amrani, Soumaya; Miranda, Miguel Angel; Pérez-Prieto, Julia

    2009-04-17

    Photoinduced charge separation in pyrene-based bichromophoric systems provides an effective strategy in organic synthesis, as shown for the [2 + 2] cycloaddition between 1,3-cyclohexadiene and styrenes as a model reaction.

  8. Phytoremediation for phenanthrene and pyrene contaminated soils

    Institute of Scientific and Technical Information of China (English)

    GAO Yan-zheng; ZHU Li-zhong

    2005-01-01

    Phytoremediation of soil contaminated with phenanthrene and pyrene was investigated using twelve plant species. Plant uptake and accumulation of these chemicals were evaluated. At the end of the experiment(45 d), the remaining respective concentrations of soil phenanthrene and pyrene in spiked vegetated soils, with initial phenanthrene of 133.3 mg/kg and pyrene of 171.5 mg/kg, were 8.71-16.4and 44.9-65.0 mg/kg, generally 4.7%-49.4% and 7.1%-35.9% lower than their concentrations in the nonvegetated soils. The loss of phenanthrene and pyrene in vegetated spiked soils were 88.2%-93.0% and 62.3%-73.8% of the added amounts of these contaminants, respectively. Although plant uptake and accumulation of these compounds were evident, and root concentrations and RCFs(root concentration factors; defined as the ratio of PAH concentrations in roots and in the soils on a dry weight basis) of these compounds significantly positively correlated to root lipid contents, plant uptake and accumulation only accounted for less than 0.01% and 0.23% of the enhanced loss of these chemicals in vegetated versus non-vegetated soils. In contrast, plant-promoted microbial biodegradation was the dominant mechanism of the phytoremediation for soil phenanthrene and pyrene contamination. Results from this study suggested a feasibility of the establishment of phytoremediation for soil PAH contamination.

  9. Bacillus subtilis is a Potential Degrader of Pyrene and Benzo[a]pyrene

    Directory of Open Access Journals (Sweden)

    Lynette Ekunwe

    2005-08-01

    Full Text Available Polycyclic Aromatic Hydrocarbons (PAHs are a group of compounds that pose many health threats to human and animal life. They occur in nature as a result of incomplete combustion of organic matter, as well as from many anthropogenic sources including cigarette smoke and automobile exhaust. PAHs have been reported to cause liver damage, red blood cell damage and a variety of cancers. Because of this, methods to reduce the amount of PAHs in the environment are continuously being sought. The purpose of this study was to find soil bacteria capable of degrading high molecular weight PAHs, such as pyrene (Pyr and benzo[a]pyrene (BaP, which contain more than three benzene rings and so persist in the environment. Bacillus subtilis, identified by fatty acid methyl ester (FAME analysis, was isolated from PAH contaminated soil. Because it grew in the presence of 33μg/ml each of pyrene, 1-AP and 1-HP, its biodegradation capabilities were assessed. It was found that after a four-day incubation period at 30oC in 20μg/ml pyrene or benzo[a]pyrene, B. subtilis was able to transform approximately 40% and 50% pyrene and benzo[a]pyrene, respectively. This is the first report implicating B. subtilis in PAH degradation. Whether or not the intermediates resulting from the transformation are more toxic than their parent compounds, and whether B. subtilis is capable of mineralizing pyrene or benzo[a]pyrene to carbon dioxide and water, remains to be evaluated.

  10. A quencher-free molecular beacon design based on pyrene excimer fluorescence using pyrene-labeled UNA (unlocked nucleic acid)

    DEFF Research Database (Denmark)

    Karlsen, Kasper Kannegård; Okholm, Anders Hauge; Kjems, Jørgen

    2013-01-01

    A quencher-free molecular beacon capable of generating pyrene excimer fluorescence has been constructed using strategically positioned pyrene-UNA monomers. Hybridization of a fully complementary RNA target was accompanied by a pyrene excimer emission increase of more than 900%, and detection of RNA...

  11. A quencher-free molecular beacon design based on pyrene excimer fluorescence using pyrene-labeled UNA (unlocked nucleic acid)

    DEFF Research Database (Denmark)

    Karlsen, Kasper Kannegård; Okholm, Anders Hauge; Kjems, Jørgen

    2013-01-01

    A quencher-free molecular beacon capable of generating pyrene excimer fluorescence has been constructed using strategically positioned pyrene-UNA monomers. Hybridization of a fully complementary RNA target was accompanied by a pyrene excimer emission increase of more than 900%, and detection of RNA...

  12. Removal of Pyrene from Contaminated Soils by White Clover

    Institute of Scientific and Technical Information of China (English)

    XU Sheng-You; CHEN Ying-Xu; LIN Kuang-Fei; CHEN Xin-Cai; LIN Qi; LI Feng; WANG Zhao-Wei

    2009-01-01

    Phytoremediation has been used as an emerging technology for remediation of soil contamination with polycyclic aromatic hydrocarbons (PAHs),ubiquitous persistent environmental pollutants derived from natural and anthropogenic processes,in the last decade.In this study,a pot experiment was conducted to investigate the potential of phytoremediation of pyrcne from spiked soils planted with white clover (Trifolium repens) in the greenhouse with a series of pyrene concentrations ranging from 4.22 to 365.38 mg kg-1.The results showed that growth of white clover on pyrenecontaminated soils was not affected.The removal of pyrene from the spiked soils planted with white clover was obviously higher than that from the unplanted soils.At the end of the experiment (60 d),the average removal ratio of pyrene in the spiked soils with white clover was 77%,which was 31% and 57% higher than those of the controls with or without micobes,respeetivcly.Both roots and shoots of white clover took up pyrene from the spiked soils and pyrene uptake increased with the soil pyrene concentration.However,the plant-enhanced dissipation of soil pyrene may be the result of plant-promoted microbial degradation and direct uptake and accumulation of pyrene by white clover were only a small part of the pyrene dissipation.Bioconcentration factors of pyrene (BCFs,ratio of pyrene,on a dry weight basis,in the plant to that in the soil) tended to decrease with increase in the residual soil pyrene concentration.Therefore,removal of pyrene in the contaminated soils was feasible using white clove.

  13. Substrate effects in the photoenhanced ozonation of pyrene

    Directory of Open Access Journals (Sweden)

    S. A. Styler

    2010-11-01

    Full Text Available We report the effects of actinic illumination on the heterogeneous ozonation kinetics of solid pyrene films and pyrene adsorbed at air-octanol and air-aqueous interfaces. Upon illumination, the ozonation of solid pyrene films and pyrene at the air-aqueous interface proceeds more quickly than in darkness; no such enhancement is observed for pyrene at the air-octanol interface. Under dark conditions, the reaction of pyrene at all three interfaces proceeds via a Langmuir-Hinshelwood-type surface mechanism. In the presence of light, Langmuir-Hinshelwood kinetics are observed for solid pyrene films but a linear dependence upon gas-phase ozone concentration is observed at the air-aqueous interface. We interpret these results as evidence of the importance of charge-transfer pathways for the ozonation of excited-state pyrene. The dramatically different behaviour of pyrene at the surface of these three simple reaction environments highlights the difficulties inherent in representing complex reactive surfaces in the laboratory, and suggests caution in extrapolating laboratory results to environmental surfaces.

  14. Substrate effects in the photoenhanced ozonation of pyrene

    Directory of Open Access Journals (Sweden)

    S. A. Styler

    2011-02-01

    Full Text Available We report the effects of actinic illumination on the heterogeneous ozonation kinetics of solid pyrene films and pyrene adsorbed at air-octanol and air-aqueous interfaces. Upon illumination, the ozonation of solid pyrene films and pyrene at the air-aqueous interface proceeds more quickly than in darkness; no such enhancement is observed for pyrene at the air-octanol interface. Under dark conditions, the reaction of pyrene at all three interfaces proceeds via a Langmuir-Hinshelwood-type surface mechanism. In the presence of light, Langmuir-Hinshelwood kinetics are observed for solid pyrene films but a linear dependence upon gas-phase ozone concentration is observed at the air-aqueous interface. We interpret these results as evidence of the importance of charge-transfer pathways for the ozonation of excited-state pyrene. The dramatically different behaviour of pyrene at the surface of these three simple reaction environments highlights the difficulties inherent in representing complex reactive surfaces in the laboratory, and suggests caution in extrapolating laboratory results to environmental surfaces.

  15. Zero kinetic energy photoelectron spectroscopy of pyrene.

    Science.gov (United States)

    Zhang, Jie; Han, Fangyuan; Kong, Wei

    2010-10-28

    We report zero kinetic energy photoelectron (ZEKE) spectroscopy of pyrene via resonantly enhanced multiphoton ionization. Our analysis centers on the symmetry of the first electronically excited state (S(1)), its vibrational modes, and the vibration of the ground cationic state (D(0)). From comparisons between the observed vibrational frequencies and those from ab initio calculations at the configuration interaction singles level using the 6-311G (d,p) basis set, and based on other previous experimental and theoretical reports, we confirm the (1)B(2u) symmetry for the S(1) state. This assignment represents a reversal in the energy order of the two closely spaced electronically excited states from our theoretical calculation, and extensive configuration interactions are attributed to this result. Among the observed vibrational levels of the S(1) state, three are results of vibronic coupling due to the nearby second electronically excited state. The ZEKE spectroscopy obtained via the vibronic levels of the S(1) state reveals similar modes for the cation as those of the intermediate state. Although we believe that the ground ionic state can be considered a single electron configuration, the agreement between theoretical and experimental frequencies for the cation is limited. This result is somewhat surprising based on our previous work on cata-condensed polycyclic aromatic hydrocarbons and small substituted aromatic compounds. Although a relatively small molecule, pyrene demonstrates its nonrigidity via several out-of-plane bending modes corresponding to corrugation of the molecular plane. The adiabatic ionization potential of neutral pyrene is determined to be 59 888 ± 7 cm(-1).

  16. Benzo[a]pyrene degradation by Sphingomonas yanoikuyae JAR02

    Energy Technology Data Exchange (ETDEWEB)

    Rentz, Jeremy A. [Civil and Environmental Engineering, University of Iowa, Iowa City, IA 52242 (United States)], E-mail: rentz@wsu.edu; Alvarez, Pedro J.J. [Civil and Environmental Engineering, Rice University, Houston, TX 77251 (United States); Schnoor, Jerald L. [Civil and Environmental Engineering, University of Iowa, Iowa City, IA 52242 (United States)

    2008-02-15

    Batch experiments were conducted to characterize the degradation of benzo[a]pyrene, a representative high molecular weight (HMW) polycyclic aromatic hydrocarbon (PAH), by Sphingomonas yanoikuyae JAR02. Concentrations up to the solubility limit (1.2 {mu}g l{sup -1}) of benzo[a]pyrene were completely removed from solution within 20 h when the bacterium was grown on salicylate. Additional experiments with [{sup 14}C]7-benzo[a]pyrene demonstrated 3.8% mineralization over 7 days when salicylate was present is solution, and one major radio-labeled metabolite was observed that accounted for {approx}10% of the initial radio-label. Further characterization of the radio-labeled metabolite using HPLC/MS and HPLC/MS/MS identified radio-labeled pyrene-8-hydroxy-7-carboxylic acid and unlabeled pyrene-7-hydroxy-8-carboxylic acid as novel ring-cleavage metabolites, and a benzo[a]pyrene degradation pathway was proposed. Results indicate that biostimulation of HMW PAH degradation by salicylate, a water-soluble, non-toxic substrate, has significant potential for in situ bioremediation. - Benzo[a]pyrene degradation and mineralization by Sphingomonas yanoikuyae JAR02 was stimulated with salicylate, and novel ring-cleavage metabolites were identified.

  17. 1-Phenyl-3-(pyren-1-ylprop-2-en-1-one

    Directory of Open Access Journals (Sweden)

    Jiannian Yao

    2008-03-01

    Full Text Available The title compound, C25H16O, was prepared by the condensation reaction of pyrene-1-carbaldehyde and acetophenone in ethanol solution at room temperature. The phenyl ring forms a dihedral angle of 39.10 (11° with the pyrene ring system. In the crystal structure, adjacent pyrene ring systems are linked by aromatic π–π stacking interactions, with a perpendicular interplanar distance of 3.267 (6 Å and a centroid–centroid offset of 2.946 (7 Å.

  18. Incorporation of pyrene in polypyrrole/polystyrene magnetic beads.

    Science.gov (United States)

    Głowala, Paulina; Budniak, Adam; Krug, Pamela; Wysocka, Barbara; Berbeć, Sylwia; Dec, Robert; Dołęga, Izabela; Kacprzak, Kamil; Wojciechowski, Jarosław; Kawałko, Jakub; Kępka, Paweł; Kępińska, Daria; Kijewska, Krystyna; Mazur, Maciej

    2014-10-15

    Pyrene, a fluorescent dye, was incorporated into polystyrene particles coated with polypyrrole. The incorporation was achieved by treating the polypyrrole/polystyrene (PPy/PS) beads in a tetrahydrofuran (THF) solution of the pyrene fluorophore followed by rinsing with methanol. The polystyrene cores of the beads swell in THF, allowing penetration of pyrene molecules into the polystyrene structure. The addition of methanol causes contraction of the swollen polystyrene, which encapsulates the dye molecules inside the beads. It is shown that the polypyrrole coating is permeable with respect to both the dye and the solvent, allowing the transport of molecules between the polystyrene cores and the contacting solution. The polypyrrole adlayer can be used as a matrix for the incorporation of magnetic nanoparticles. Embedded particles provide magnetic functionality to the PPy/PS beads. It is demonstrated that the pyrene-loaded beads can be manipulated with an external magnetic field. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Ultrafast third-order nonlinear optical response of pyrene derivatives

    Science.gov (United States)

    Shi, Yufang; Li, Zhongguo; Fang, Yu; Sun, Jinyu; Zhao, Minggen; Song, Yinglin

    2017-05-01

    Two mono-substituted pyrene derivatives with delocalized electron system 1-(pyren-1-yl)-3-(4-Methyl thiophene-2-yl) acrylic ketone (13#) and 1-(pyren-1-yl)-3-(4-bromo thiophene-2-yl) acrylic ketone (15#) were successfully synthesized. The resultant compounds were characterized by nuclear magnetic resonance (NMR), infrared spectroscopy (IR), high resolution mass spectrum (HR-MS), and UV-vis spectra. The third-order nonlinear optical properties of the compounds were investigated using Z-scan technique with femtosecond laser pulses at 500 nm and 700 nm, respectively. Both of the compounds showed a decrease in transmittance about the focus, which are typical of two-photon absorption. It was found that the two-photon absorption behavior of the pyrene derivatives were modified by substituents on thiophene ring. These results indicate that both compounds can be promising candidates for future optoelectronic and bio-imaging applications.

  20. Metabolism of benzo(a)pyrene and identification of the major benzo(a)pyrene-DNA adducts in cultured human colon

    DEFF Research Database (Denmark)

    1978-01-01

    ]benzo(a)pyrene for another 24 hr and the binding to cellular DMA and protein was measured. Two adducts, formed between benzo(a)pyrene and DMA, have been isolated. The major adduct (72 to 100%) was formed between the 10-position of benzo(a)pyrene diol-epoxide I and the 2-amino group of guanine, and the minor adduct...

  1. Bioremediation of Pyrene-Contaminated Soils Using Biosurfactant

    Directory of Open Access Journals (Sweden)

    Jorfi

    2014-10-01

    Full Text Available Background Polycyclic aromatic hydrocarbons (PAHs are persistence organic chemicals with proved carcinogenic and mutagenic hazards. These compounds are usually adsorbed in soils in vicinity of oil and gas industries. Bioremediation of PAHs contaminated soils is difficult due to hydrophobic nature of PAHs. Objectives The main purpose of the current study was to determine the pyrene removal efficiency in synthetically contaminated soil, using biosurfactant. Materials and Methods Four pure bacterial strains capable of pyrene degradation were isolated from contaminated soils via enrichment techniques. The soil samples were spiked with an initial pyrene concentration of 500 mg/kg and subjected to bioremediation using a mixed culture comprised of previously isolated strains, in addition to application of biosurfactant during 63 days. Results The pyrene removal efficiency in samples containing biosurfactant, without biosurfactant and controls, were 86.4%, 59.8% and 14%, respectively, after 63 days. The difference of pyrene removal efficiency between the biosurfactant-containing samples and the ones without it was significant (P < 0.05. Conclusions Application of rhamnolipid biosurfactant produced by Pseudomonas aeruginosa significantly improved pyrene removal in contaminated soils.

  2. EROD activities of liver in Mugil so-iuy exposed to benzo(a) pyrene, pyrene and their mixture

    Institute of Scientific and Technical Information of China (English)

    Wang Chonggang; Chen Jixin; Yu Ang; Zheng Weiyun

    2003-01-01

    The effects on hepatic EROD (7-ethoxyresorufin O-deethylase) in Mugil so-iuy exposed to benzo(a)pyrene (BaP), pyrene and their mixtures of equal concentration were investigated, at concentrations of 0.1, 1.0, 5.0, 10.0, 50.0 μg/dm3, in experimental condition. Time-effects and doseresponse of the biochemical indexs were observed. The results showed that the hepatic EROD activities were induced by the exposure of BaP, pyrene and their mixtures at high concentration. Dose-response connections were that the hepatic EROD activities were elevated with increasing concentration of the pollutants. The combined effect of BaP and pyrene at 1:1 concentration ratio on hepatic EROD activity was antagonism.

  3. How to link pyrene to its host lipid to minimize the extent of membrane perturbations and to optimize pyrene dimer formation

    DEFF Research Database (Denmark)

    Franova, M. D.; Repakova, J.; Holopainen, J. M.;

    2014-01-01

    atomistic molecular dynamics simulations to consider membranes where pyrene moieties are attached to lipid acyl chains in varying positions. We find that in a DOPC bilayer the conformational ordering of lipids around di-pyrenyl-PC probes is altered to a largely similar extent regardless of where the pyrene...... moiety is attached to the hydrocarbon chain. This is in contrast to saturated membranes, where pyrene-induced perturbations have been observed to be more prominent. Meanwhile, the formation of pyrene dimers depends on the linkage point between pyrene and its host lipid. Membrane-spanning dimers between...

  4. Anthracene + Pyrene Solid Mixtures: Eutectic and Azeotropic Character.

    Science.gov (United States)

    Rice, James W; Fu, Jinxia; Suuberg, Eric M

    2010-09-01

    To better characterize the thermodynamic behavior of a binary polycyclic aromatic hydrocarbon mixture, thermochemical and vapor pressure experiments were used to examine the phase behavior of the anthracene (1) + pyrene (2) system. A solid-liquid phase diagram was mapped for the mixture. A eutectic point occurs at 404 K at x(1) = 0.22. A model based on eutectic formation can be used to predict the enthalpy of fusion associated with the mixture. For mixtures that contain x(1) < 0.90, the enthalpy of fusion is near that of pure pyrene. This and X-ray diffraction results indicate that mixtures of anthracene and pyrene have pyrene-like crystal structures and energetics until the composition nears that of pure anthracene. Solid-vapor equilibrium studies show that mixtures of anthracene and pyrene form solid azeotropes at x(1) of 0.03 and 0.14. Additionally, mixtures at x(1) = 0.99 sublime at the vapor pressure of pure anthracene, suggesting that anthracene behavior is not significantly influenced by x(2) = 0.01 in the crystal structure.

  5. Dual partitioning and attachment effects of rhamnolipid on pyrene biodegradation under bioavailability restrictions

    NARCIS (Netherlands)

    Congiu, E.; Parsons, J.R.; Ortega-Calvo, J.J.

    2015-01-01

    We investigated the effects of different bioavailability scenarios on the rhamnolipid-enhanced biodegradation of pyrene by the representative polycyclic aromatic hydrocarbon degrader Mycobacterium gilvum VM552. This biosurfactant enhanced biodegradation when pyrene was provided in the form of solid

  6. Dual partitioning and attachment effects of rhamnolipid on pyrene biodegradation under bioavailability restrictions

    NARCIS (Netherlands)

    Congiu, E.; Parsons, J.R.; Ortega-Calvo, J.J.

    2015-01-01

    We investigated the effects of different bioavailability scenarios on the rhamnolipid-enhanced biodegradation of pyrene by the representative polycyclic aromatic hydrocarbon degrader Mycobacterium gilvum VM552. This biosurfactant enhanced biodegradation when pyrene was provided in the form of solid

  7. Evaluating pyrene toxicity on Arctic key copepod species Calanus hyperboreus

    DEFF Research Database (Denmark)

    Nørregaard, Rasmus Dyrmose; Nielsen, Torkel Gissel; Friis Møller, Eva;

    2014-01-01

    Calanus hyperboreus is a key species in the Arctic regions because of its abundance and role in the Arctic food web. Exploitation of the off shore oil reserves along Western Greenland is expected in the near future, and it is important to evaluate the acute and chronic effects of oil emissions....... Lowered reproductive output, reduced grazing, and reduced ability to metabolize pyrene suggest that oil contamination may constitute a risk to C. hyperboreus recruitment, energy transfer in the food web and transfer of pyrene to higher trophic levels...

  8. Rapid genotyping using pyrene-perylene locked nucleic acid complexes

    DEFF Research Database (Denmark)

    Kumar, Santhosh T.; Myznikova, Anna; Samokhina, Evgeniya

    2013-01-01

    We have developed an assay for single strand DNA and RNA detection which is based on novel pyrene-perylene FRET pairs attached to short LNA/DNA probes. The assay is based on ratiometric emission upon binding of target DNA/RNA by three combinations of fluorescent LNA/DNA reporter strands. Specific...... is achieved with advantages of large Stokes shift (115 nm), high fluorescence quantum yields and low limit of target detection values (Rapid and accurate genotyping of highly polymorphic HIV Pol cDNA and RNA fragments performed herein proves the possibility for broad application of the novel pyrene...

  9. Pyrene intercalating nucleic acids with a carbon linker.

    Science.gov (United States)

    Østergaard, Michael E; Wamberg, Michael C; Pedersen, Erik B

    2011-03-01

    We have synthesized a carbon linker analogue of INA (oligonucleotides containing insertions of 1-O-(1-pyrenylmethyl)glycerol). Thermal stability studies showed an increase in melting temperature in favor of the carbon linker analogue. We also synthesized a carbon linker analogue with two pyrenes geminally attached. Fluorescence studies of this intercalating nucleic acid with the pyrene moieties inserted as a bulge showed formation of an excimer band. When a mismatch was introduced at the site of the intercalator, an excimer band was formed for the destabilized duplexes whereas an exciplex band was observed when the stability of the duplex was retained.

  10. Electrical Properties of Multi-Pyrene/Porphyrin-Dendrimers.

    Science.gov (United States)

    Martínez-Klimov, Mark Euguenii; Organista-Mateos, Ulises; Borja-Miranda, Andrés; Rivera, Margarita; Amelines-Sarria, Oscar; Martínez-García, Marcos

    2015-09-22

    Dendrimers bearing pyrene donor groups have been obtained and act as efficient light-harvesting antennae capable of transferring light energy through space from their periphery to their core. The light-harvesting ability increases with each generation due to an increase in the number of peripheral pyrenes. In order to evaluate the photovoltaic properties of the compounds, thermal evaporated thin films were produced and the voltage response in the presence of visible light was obtained. The energy transfer efficiency was found to be almost quantitative for the first and second generations. The dendrimers have the potential to become integral components of molecular photonic devices.

  11. Electrical Properties of Multi-Pyrene/Porphyrin-Dendrimers

    Directory of Open Access Journals (Sweden)

    Mark Euguenii Martínez-Klimov

    2015-09-01

    Full Text Available Dendrimers bearing pyrene donor groups have been obtained and act as efficient light-harvesting antennae capable of transferring light energy through space from their periphery to their core. The light-harvesting ability increases with each generation due to an increase in the number of peripheral pyrenes. In order to evaluate the photovoltaic properties of the compounds, thermal evaporated thin films were produced and the voltage response in the presence of visible light was obtained. The energy transfer efficiency was found to be almost quantitative for the first and second generations. The dendrimers have the potential to become integral components of molecular photonic devices.

  12. Smartphone-enabled filterless fluorescence assay utilizing the pyrene excimer

    Science.gov (United States)

    Goertz, John P.; White, Ian M.

    2015-03-01

    Fluorescence microscopy offers a number of advantages for cell- and biomarker-based diagnostics with regards to ease of use and interpretation, sensitivity, and specificity. However, its use in low-resource settings is often hindered by the need for bulky microscopes with expensive excitation and filter setups. While many advances have been made towards utilizing smartphones as microscopes, there remains a reliance on complex attachments to facilitate fluorescence microscopy. Here, we report progress towards a filter-less fluorescent assay utilizing ultraviolet light, an unmodified smartphone, and pyrene-labeled aptamers. The pyrene monomer is excited at a wavelength of 350 nm and emits at approximately 390 nm; when two pyrene molecules are brought into close proximity, however, they form an excimer which emits at approximately 490 nm. We have engineered pyrene-conjugated DNA sequences such that the fluorophores, normally in monomeric configuration, are brought into proximity upon binding of the DNA to its target. The large Stokes shift between excitation and emission of the excimer allows us to detect such biorecognition events with an unfiltered smartphone camera, enabling the use of this assay in low-resource settings where portability and easeof- use are paramount.

  13. PYRENE INTERCALATING NUCLEIC ACIDS WITH A CARBON LINKER

    DEFF Research Database (Denmark)

    Østergaard, Michael E.; Wamberg, Michael Chr.; Pedersen, Erik Bjerregaard

    2011-01-01

    geminally attached. Fluorescence studies of this intercalating nucleic acid with the pyrene moieties inserted as a bulge showed formation of an excimer band. When a mismatch was introduced at the site of the intercalator, an excimer band was formed for the destabilized duplexes whereas an exciplex band...

  14. Chimerical pyrene-based [7]helicenes as twisted polycondensed aromatics.

    Science.gov (United States)

    Buchta, Michal; Rybáček, Jiří; Jančařík, Andrej; Kudale, Amit A; Buděšínský, Miloš; Chocholoušová, Jana Vacek; Vacek, Jaroslav; Bednárová, Lucie; Císařová, Ivana; Bodwell, Graham J; Starý, Ivo; Stará, Irena G

    2015-06-01

    Chimerical pyrene-based dibenzo[7]helicene rac-1 and 2H-pyran[7]helicene (M,R,R)-(-)-2, in which two pyrene subunits are fused to the [7]helicene/[7]heterohelicene scaffold, were synthesised by means of Ni(0) - or Co(I) -mediated [2+2+2] cycloisomerisation of dipyrenyl-acetylene-derived triynes. Pyrene-based dibenzo[7]helicene 1 was obtained in enantioenriched form by enantioselective cycloisomerisation under Ni(0) /QUINAP catalysis (57 % ee) or in enantiopure form by racemate resolution by liquid chromatography on a chiral column. 1,3-Allylic-type strain-controlled diastereoselective cycloisomerisation was employed in the synthesis of enantiopure (M,R,R)-(-)-2. Physicochemical properties of 1 and 2 encompassing the helicity assignment, stability to racemisation, X-ray crystal structure, UV/Vis, experimental/calculated electronic circular dichroism and fluorescence spectra were studied. Accordingly, comparison of the X-ray crystal structure of (M,R,R)-(-)-2 with calculated structures (DFT: B3LYP/cc-pVDZ, B97D/cc-pVDZ) indicated that its helical backbone is slightly over-flattened owing to intramolecular dispersion forces between tert-butylated pyrene subunits. Both 1 and 2 are fluorescent (with quantum yields in dichloromethane of ΦF =0.10 and 0.17, respectively) and are suggested to form intramolecular excimer states upon excitation, which are remarkably stabilised and exhibit large Stokes shifts (296 and 203 nm, respectively).

  15. Electronic transmission of three-terminal pyrene molecular bridge

    Institute of Scientific and Technical Information of China (English)

    Wang Li-Guang; Zhang Xiu-Mei; Terence Kin Shun Wong; Katsunori Tagami; Masaru Tsukada

    2009-01-01

    This paper investigates theoretically the electronic transmission spectra of the three terminal pyrene molecular bridge and the quantum current distribution on each bond by the tight-binding model based on nonequilibrium Green's function and the quantum current density approach, in which one π molecular orbital is taken into account per carbon atom when the energy levels and HOMO-LUMO gap are obtained. The transmission spectra show that the electronic transmission of the three terminal pyrene molecular bridge depends obviously on the incident electronic energy and the pyrene eigenencrgy. The symmetrical and oscillation properties of the transmission spectra are illustrated. A novel plus-minus energy switching function is found. The quantum current distribution shows that the loop currents inside the pyrene are induced, and some bond currents are much larger than the input and the output currents. The reasons why the loop currents and the larger bond currents are induced are the phase difference of the atomic orbits and the degeneracy of the molecular orbits. The calculations illustrate that the quantum current distributions are in good agreement with Kirchhoff quantum current conservation law.

  16. Benzo(a)pyrene metabolism by murine spleen microsomes

    Energy Technology Data Exchange (ETDEWEB)

    Kawabata, T.T.; White, K.L. Jr. (Virginia Commonwealth Univ., Richmond (USA))

    1989-11-01

    The immunosuppressive actions of benzo(a)pyrene have been proposed to be mediated by reactive metabolites rather than the parent compound. Reactive metabolites which suppress splenic humoral immune responses are thought to be generated within the spleen rather than in distant tissues. Although the spleen has been shown to be capable of metabolizing benzo(a)pyrene, the relative amounts and types of metabolites generated have not been determined. In this study, high-pressure liquid chromatography was used to separate benzo(a)pyrene metabolites generated by splenic microsomes. The major metabolites generated by the splenic microsomal preparations of untreated female B6C3F1 mice were found to be the 9,10- and 7,8-dihydrodiols and 9-, 7-, and 3-hydroxy benzo(a)pyrene. The 1,3-, 3,6-, and 6,12-diones and 4,5-dihydrodiol constituted only a small fraction of the metabolites generated. The generation of all metabolites were inhibited by alpha-naphthoflavone and antiserum to NADPH-cytochrome P-450 reductase, whereas SKF 525-A had only a minimal effect. Dihydrodiol production was completely inhibited by the epoxide hydrolase inhibitor, trichloropropylene oxide. Benzo(a)pyrene pretreatment of mice produced a dramatic increase in the amount of metabolites formed; however, the pattern of metabolites remained similar to that generated by splenic microsomes of untreated mice. The role of prostaglandin synthetase in generating these metabolites was also examined. The addition of arachidonic acid in place of NADPH resulted in the formation of only quinones. Dihydrodiols and phenols were undetectable. The results of this study indicate that splenocytes may be capable of generating the 7,8-dihydrodiol, the precursor to the highly reactive 7,8-dihydrodiol-9,10-epoxide.

  17. Application of cinder gel-beads/reeds combination strategy for bioremediation of pyrene- and indeno(1,2,3-cd)pyrene-contaminated estuarine wetlands.

    Science.gov (United States)

    Tian, Weijun; Liu, Qing; Huang, Ruying; Jin, Xin; Qiao, Kaili

    2016-06-01

    Pseudomonas putida PYR1 and Acinetobacter baumannii INP1 isolated from Liaohe estuarine wetlands were entrapped in cinder beads to make cinder gel-beads. They were combined with reeds for bioremediation of pyrene- and indeno(1,2,3-cd)pyrene-contaminated estuarine wetlands. The results showed that the removal percentages of pyrene and indeno(1,2,3-cd)pyrene (69.2 and 89.8 % respectively) in 40 days using cinder gel-beads/reeds were obviously higher than those using cinder gel-beads(52.6 and 70.0 %) and reeds (33.5 and 78.6 %) alone, about four times those of the control (13.8 and 31.1 %). The removal efficiency of pyrene was in the order cinder gel-beads/reeds > cinder gel-beads > reeds > control, which was different from cinder gel-beads/reeds > reeds > cinder gel-beads > control of indeno(1,2,3-cd)pyrene. This result indicated that the functional mechanism to remove indeno(1,2,3-cd)pyrene with six benzene rings was different from that of pyrene. The synergistic effect of reeds and cinder gel-beads for indeno(1,2,3-cd)pyrene removal was weaker than that of pyrene. But the absorption and transformation of reeds with high efficiency were beneficial to indeno(1,2,3-cd)pyrene removal from wetlands. Additionally, microbial analysis with high-throughput sequencing presented that Gammaproteobacteria were dominant PAH-degrading groups in bioremediation with immobilized bacteria. This strategy can serve as a model system for the removal of more complex or structurally related organic compounds from contaminated sites.

  18. Effects of oil dispersants on photodegradation of pyrene in marine water

    Energy Technology Data Exchange (ETDEWEB)

    Gong, Yanyan [Environmental Engineering Program, Department of Civil Engineering, Auburn University, Auburn, AL 36849 (United States); College of Environmental Science and Engineering, Nankai University, Tianjin 300071 (China); Fu, Jie [Environmental Engineering Program, Department of Civil Engineering, Auburn University, Auburn, AL 36849 (United States); O’Reilly, S.E. [U.S. Department of the Interior, Gulf of Mexico OCS, Office of Environment, New Orleans, LA 70123 (United States); Zhao, Dongye, E-mail: zhaodon@auburn.edu [Environmental Engineering Program, Department of Civil Engineering, Auburn University, Auburn, AL 36849 (United States)

    2015-04-28

    Highlights: • Oil dispersant enhances pyrene photodegradation in seawater. • Oil dispersant increases formation of superoxide radicals. • Pyrene photodegradation shows a two-stage kinetics and follows first-order rate law. • Pyrene is degraded mainly through electron transfer from excited pyrene to oxygen. • Higher ionic strength and temperature and lower HA favor pyrene photodegradation. - Abstract: This work investigated effects of a popular oil dispersant (Corexit EC9500A) on UV- or sunlight-mediated photodegradation of pyrene (a model polycyclic aromatic hydrocarbon) in seawater. The presence of 18 and 180 mg/L of the dispersant increased the first-order photodegradation rate by 5.5% and 16.7%, respectively, and reduced or ceased pyrene volatilization. By combining individual first-order rate laws for volatilization and photodegradation, we proposed an integrated kinetic model that can adequately predict the overall dissipation of pyrene from seawater. Mechanistic studies indicated that superoxide radicals played a predominant role in pyrene photodegradation, and the dispersant enhanced formation of superoxide radicals. 1-Hydroxypyrene was the main intermediate regardless of the dispersant, suggesting that electrons were transferred from excited pyrene to oxygen. In the presence of 18 mg/L of the dispersant, the photodegradation rate increased with increasing ionic strength and temperature, but decreased with increasing HA concentration, and remained independent of solution pH. The results are important in understanding roles of oil dispersants on environmental fate of persistent oil components in natural and engineered systems.

  19. Association between Mutation Spectra and Stable and Unstable DNA Adduct Profiles in Salmonella for Benzo[a]pyrene and Dibenzo[a.l]pyrene

    Science.gov (United States)

    Benzo[a]pyrene (BP) and dibenzo[a,l]pyrene (DBP) are two polycyclic aromatic hydrocarbons (PAHs) that exhibit distinctly different mutagenicity and carcinogenicity profiles. Although some studies show that these PAHs produce unstable DNA adducts, conflicting data and arguments ha...

  20. Effects of temperature and soil components on emissions from pyrolysis of pyrene-contaminated soil.

    Science.gov (United States)

    Risoul, Véronique; Richter, Henning; Lafleur, Arthur L; Plummer, Elaine F; Gilot, Patrick; Howard, Jack B; Peters, William A

    2005-11-11

    Effects of temperature and soil on yields and identities of light gases (H2, CH4, C2H2, C2H4, C2H6, CO, and CO2) and polycyclic aromatic hydrocarbons (PAH) from thermal treatment of a pyrene-contaminated (5 wt%) soil in the absence of oxygen were determined for a U.S. EPA synthetic soil matrix prepared to proxy U.S. Superfund soils. Shallow piles (140-170 mg) of contaminated soil particles and as controls, neat (non-contaminated) soil (140-160 mg), neat pyrene (10-15 mg), neat sand (230 mg), and pyrene-contaminated sand (160 mg), were heated in a ceramic boat inside a 1.65 cm i.d. pyrex tube at temperatures from 500 to 1100 degrees C under an axial flow of helium. Volatile products spent 0.2-0.4s at temperature before cooling. Light gases, PAH and a dichloromethane extract of the residue in the ceramic boat, were analyzed by gas chromatography or high pressure liquid chromatography (HPLC). Over 99% pyrene removal was observed when heating for a few tens of seconds in all investigated cases, i.e., at 500, 650, 750, 1000, and 1100 degrees C for soil, and 750 and 1000 degrees C for sand. However, each of these experiments gave significant yields (0.2-16 wt% of the initial pyrene) of other PAH, e.g., cyclopenta[cd]pyrene (CPP), which mutates bacterial cells and human cells in vitro. Heating pyrene-polluted soil gave pyrene conversions and yields of acetylene, CPP, and other PAH exceeding those predicted from similar, but separate heating of neat soil and neat pyrene. Up to 750 degrees C, recovered pyrene, other PAH, and light gases accounted for all or most of the initial pyrene whereas at 1000 and 1100 degrees C conversion to soot was significant. A kinetic analysis disentangled effects of soil-pyrene interactions and vapor phase pyrolysis of pyrene. Increase of residence time was found to be the main reason for the enhanced conversion of pyrene in the case of the presence of a solid soil or sand matrix. Light gas species released due to the thermal treatment, such as

  1. Optical nonlinearity and charge transfer analysis of pyrene adsorbed on silver: Computational and experimental investigations

    Science.gov (United States)

    Reeta Felscia, U.; Rajkumar, Beulah J. M.; Sankar, Pranitha; Philip, Reji; Briget Mary, M.

    2017-09-01

    The interaction of pyrene on silver has been investigated using both experimental and computational methods. Hyperpolarizabilities computed theoretically together with experimental nonlinear absorption from open aperture Z-scan measurements, point towards a possible use of pyrene adsorbed on silver in the rational design of NLO devices. Presence of a red shift in both simulated and experimental UV-Vis spectra confirms the adsorption on silver, which is due to the electrostatic interaction between silver and pyrene, inducing variations in the structural parameters of pyrene. Fukui calculations along with MEP plot predict the electrophilic nature of the silver cluster in the presence of pyrene, with NBO analysis revealing that the adsorption causes charge redistribution from the first three rings of pyrene towards the fourth ring, from where the 2p orbitals of carbon interact with the valence 5s orbitals of the cluster. This is further confirmed by the downshifting of ring breathing modes in both the experimental and theoretical Raman spectra.

  2. Adsorption of Pyrene onto the Agricultural By-Product: Corncob.

    Science.gov (United States)

    Li, Xiaojun; Tong, Dongli; Allinson, Graeme; Jia, Chunyun; Gong, Zongqing; Liu, Wan

    2016-01-01

    The adsorption behavior of pyrene on corncob was studied to provide a theoretical basis for the possible use of this material as an immobilized carrier for improving the bioremediation of PAH-contaminated soil. The results were as follows. Kinetic experiments showed that the adsorption processes obeyed a pseudo-second-order model. The intraparticle diffusion of Weber-Morris model fitting showed that the film and intraparticle diffusions were the key rate-limiting processes, and the adsorption process mainly consisted of three steps: boundary layer diffusion and two intra-particle diffusions. Experimental adsorption data for pyrene were successfully described by the adsorption-partition equilibrium model. The maximum adsorption capacity at 25°C was 214.8 μg g(-1). The adsorption contribution decreased significantly when the Ce/Sw (the equilibrium concentration/solubility in water) was higher than 1. Adsorption decreased with increased temperature. Based on the above results, the corncob particles could be helpful in the bioremediation of pyrene-contaminated soil.

  3. Chemical transformations of the pyrene K-region for functional materials

    OpenAIRE

    Zöphel, L.

    2012-01-01

    In dieser Arbeit wurde eine neue Methode zur asymmetrischen Substitution der K-Regionen von Pyren entwickelt, auf welcher das Design und die Synthese von neuartigen, Pyren-basierten funktionalen Materialien beruht. Eine Vielzahl von Substitutionsmustern konnte erfolgreich realisiert werden um die Eigenschaften entsprechend dem Verwendungszweck anzupassen. Der polyzyklische aromatische Kohlenwasserstoff (PAK) Pyren setzt sich aus vier Benzolringen in Form einer planaren Raute mit zwei gegenübe...

  4. Degradation of Polycyclic Aromatic Hydrocarbon Pyrene by Biosurfactant-Producing Bacteria Gordonia cholesterolivorans AMP 10

    OpenAIRE

    2016-01-01

    Pyrene degradation and biosurfactant activity by a new strain identified as Gordonia cholesterolivorans AMP 10 were studied. The strain grew well and produced effective biosurfactants in the presence of glucose, sucrose, and crude oil. The biosurfactants production was detected by the decreased surface tension of the medium and emulsification activity.  Analysis of microbial growth parameters showed that AMP10 grew best at 50 µg mL-1 pyrene concentration, leading to 96 % degradation of pyrene...

  5. Interaction of heavy metals and pyrene on their fates in soil and tall fescue (Festuca arundinacea).

    Science.gov (United States)

    Lu, Mang; Zhang, Zhong-Zhi; Wang, Jing-Xiu; Zhang, Min; Xu, Yu-Xin; Wu, Xue-Jiao

    2014-01-21

    90-Day growth chamber experiments were performed to investigate the interactive effect of pyrene and heavy metals (Cu, Cd, and Pb) on the growth of tall fescue and its uptake, accumulation, and dissipation of heavy metals and pyrene. Results show that plant growth and phytomass production were impacted by the interaction of heavy metals and pyrene. They were significantly decreased with heavy metal additions (100-2000 mg/kg), but they were only slightly declined with pyrene spiked up to 100 mg/kg. The addition of a moderate dosage of pyrene (100 mg/kg) lessened heavy metal toxicity to plants, resulting in enhanced plant growth and increased metal accumulation in plant tissues, thus improving heavy metal removal by plants. In contrast, heavy metals always reduced both plant growth and pyrene dissipation in soils. The chemical forms of Cu, Cd, and Pb in plant organs varied with metal species and pyrene addition. The dissipation and mineralization of pyrene tended to decline in both planted soil and unplanted soils with the presence of heavy metals, whereas they were enhanced with planting. The results demonstrate the complex interactive effects of organic pollutants and heavy metals on phytoremediation in soils. It can be concluded that, to a certain extent, tall fescue may be useful for phytoremediation of pyrene-heavy metal-contaminated sites. Further work is needed to enhance methods for phytoremediation of heavy metal-organics co-contaminated soil.

  6. Separation of water-soluble metabolites of benzo[a]pyrene formed by cultured human colon

    DEFF Research Database (Denmark)

    1979-01-01

    A method has been developed to separate conjugated metabolites of benzo[a]pyrene into three major fractions: sulfate esters, glucuronides and glutathione conjugates. In cultured human colon, formation of sulfate esters and glutathione conjugates is the major conjugation pathway, while formation o......-hydroxybenzo[a]pyrene were the major substrates for sulfotransferase in cultured human colon....

  7. Biotransformering af pyren i havbørsteormen Nereis virens

    DEFF Research Database (Denmark)

    Jørgensen, Anne; Giessing, Anders; Juul Rasmussen, Lene;

    hydroxylase, glucuronosyl transferase og sulfotransferase. Pyren hydroxylase aktivitet blev bestemt til at være cytochrom P450 (CYP) medieret og den fase II reaktion med størst kapacitet var glucuronidering. Sulfotransferase enzymerne havde imidlertid den højeste specificitet. Pyren hydroxylase aktivitet var...

  8. Simple Fluorimetric Determination of Benzo[a]pyrene in Cigarette Smoke without Preseparation Procedure

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Constant-energy synchronous fluorimetry was used for the identification of benzo[a]pyrene in mixtures with a detection limit of 1.34 nmol/L. The recovery experiments in cigarette smoke samples have also obtained satisfactory results of 99.1-103.5% for benzo[a]pyrene.

  9. Pyrene biotransformation and kinetics in the hepatopancreas of the isopod Porcellio scaber.

    Science.gov (United States)

    Stroomberg, G J; Ariese, F; Gestel, C A M van; Hattum Bv, B van; Velthorst, N H; Straalen, N M van

    2004-10-01

    Various techniques exist for polycyclic aromatic hydrocarbon (PAH) determination in environmental samples, but an adequate risk assessment of PAHs should include aspects such as bioavailability of the contaminant and biotransformation capacity of the species under investigation. In this study, we provided an analysis of the kinetics of pyrene in the terrestrial isopod Porcellio scaber. Isopods were exposed to pyrene in their food (10 microg/g d/w) for 7 days followed by an elimination period of 7 days. The animals were dissected, and the hepatopancreases were analyzed for pyrene biotransformation products; nonmetabolised pyrene in the gut was also monitored. Concentrations of 1-hydroxypyrene in the hepatopancreas were very low. Almost all of the pyrene was found as three conjugates: pyrene-1-glucoside, pyrene-1-sulfate, and a third unknown 1-hydroxypyrene conjugate. Concentrations of the metabolites were extremely variable between individuals because of variable feeding activity. An apparent steady state was reached already after 24 hours of exposure, whereas elimination was complete 48 hours after ending the exposure. This rapid response to changes in the exposure concentration shows that terrestrial isopods have a high biotransformation capacity for PAHs. The data show that concentrations of parent PAHs will not provide a good indication of exposure in rapidly metabolizing invertebrates such as isopods; instead, pyrene metabolites may be considered a promising biomarker for bioavailability of PAH contamination in the field.

  10. Bis-pyrene-modified unlocked nucleic acids: synthesis, hybridization studies, and fluorescent properties

    DEFF Research Database (Denmark)

    Perlíková, Pavla; Ejlersen, Maria; Langkjaer, Niels

    2014-01-01

    in DNA*/DNA duplexes. Nevertheless, the destabilization effect of bis-pyrene-modified UNA is weaker than that of unmodified UNA. Some oligonucleotides with bis-pyrene-modified UNA incorporations displayed superior mismatch discrimination capabilities. UV/Vis absorption and molecular modeling studies...

  11. A New Pyrene-Spacer-Maleimide Dyad for Sensing Molecules with One or Two Thiol Groups

    Institute of Scientific and Technical Information of China (English)

    WANG,Zhuo; ZHANG,De-Qing; ZHU,Dao-Ben

    2006-01-01

    A new pyrene-spacer-maleimide dyad 1 was used to selectively detect cysteine in the presence of other amino acids, and sequentially react with dithiols to generate the molecule with two pyrene units showing typical excimer fluorescence. Accordingly, dyad 1 was able to differentiate molecules with one or two thiol groups.

  12. Interindividual variation in binding of benzo[a]pyrene to DNA in cultured human Bronchi

    DEFF Research Database (Denmark)

    Harris, C.C.; Autrup, Herman; Connor, R.

    1976-01-01

    The binding of benzo[a]pyrene to DNA in cultured human bronchus was measured in specimens from 37 patients. The binding values ranged from 2 to 151 picomoles of benzo[a]pyrene per milligram of DNA with an overall mean +/- standard error of 34.2 +/- 5.2. This 75-fold interindividual variation in t...

  13. Kinetic analysis of soil contained pyrene oxidation by a pulsed discharge plasma process

    Science.gov (United States)

    Huijuan, Wang; Guangshun, Zhou; He, Guo; Cong, Geng

    2017-01-01

    A pulsed discharge plasma (PDP) reactor with net anode and net cathode was established for investigating the pyrene degradation in soil under different pulse peak voltage, air flow rate, pyrene content in soil, initial pH value and initial water content of the soil. Pyrene oxidation within the 60 min discharge time was fitting according to the pseudo-first order equation and the corresponding reaction kinetics constants (k values) were calculated. The obtained results show that pyrene oxidation under all the different reaction conditions obeyed the pseudo-first order equation well. Higher pulsed peak voltage and appropriate air flow rate were in favor of the increase of reaction rate of pyrene oxidation. A higher k value could be achieved in the lower initial pyrene content (the value was 100 mg kg-1). The k value of pyrene oxidation in the case of pH = 4 was 11.2 times higher than the value obtained under the condition of pH = 9, while the initial water content of the soil also has a large effect on the oxidation rate of pyrene due to the effect of PDP. Supported by National Natural Science Foundation of China (No. 21207052).

  14. Pyrene removal from contaminated soil using electrokinetic process combined with surfactant

    Directory of Open Access Journals (Sweden)

    Seyed Enayat Hashemi

    2015-07-01

    Full Text Available Background: Pyrene is one of the stable polycyclic aromatic hydrocarbons that is considered as an important pollutants, because of extensive distribution in the environment and carcinogenic and mutagenic properties. Among the various treatment techniques, electrokinetic method is an environmental- friendly process for organic and mineral pollutants adsorbed to soil with fine pore size the same as clay and low hydraulic conductivity soils. For improving the efficiency of pyrene removal from soil, soulobilization of pyrene from soil could be used by surfactants. Materials and Methods : In this study, clay soil was selected as model because of the specific properties. Combined method using surfactant and electrokinetic was applied for pyrene removal from soil. Experiments were designed using response surface methodology (RSM, and effect of three variables includes surfactant concentration, voltage and surfactant type were evaluated for pyrene removal from contaminated soil. Results: Pyrene removal using anionic surfactants(SDS and nonionic surfactants(TX100 as a solubilizing agents has high removal efficiency. In the optimum condition with 95% confidence coefficient, utilizing mixed surfactants of sodium dodecyl sulfate and triton X-100 with the same volume, induced of 18.54 volt and 6.53 percent surfactant concentration have 94.6% pyrene removal efficiency. Conclusion:: Results of this study shows that electrokinetic process combined with surfactant as solubilizing agent could be applied as an efficient method for treating the pyrene-contaminated soils.

  15. Fluorescence chemosensors with pyrene and their interaction with nucleotide phosphate

    Institute of Scientific and Technical Information of China (English)

    李华平; 汪鹏飞; 吴世康

    1999-01-01

    A group of fluorescence chemosensor with pyrene, compounds (Ⅰ), (Ⅱ) and (Ⅲ), were synthesized The fluorescence spectra and the lifetime of these compounds were carefully measured. The fluorescence quenching spec tra of pyrenyl butyric acid, compounds (Ⅰ), (Ⅱ) and (Ⅲ) by different nucleotide phosphates, AMP ADP, ATP dTTP, were also recorded and studied. The quenching and the stability constants were calculated by Stern-Volmer equa tion and eq. (2), respectively. The mechanism of interaction between fluorescence chemosensor and nucleotide phos phate was didscussed based on the comparison of the results obtained with the CPK model of free molecules of these com pounds in the ground state.

  16. Pyrene partition behavior to the NOM: Effect of NOM characteristics and its modification by ozone preoxidation

    Institute of Scientific and Technical Information of China (English)

    Jin GUO; Jun MA

    2009-01-01

    Hydrophobic organic contaminants (HOCs)--pyrene, and natural organic matters (NOM) from different sources were taken as the test compounds to investigate the impact of physicochemical characteristics of NOM on HOCs' partition to the NOM in this study. The effects of solution property, NOM characteristics, and modification by ozone preoxidation on pyrene partition to NOM were systematically evaluated. According to the fluorescence quenching method, the partition coefficient Koc of pyrene to NOM was calculated, which was found to have a great relationship with the aromatic structures and hydrophobic functional groups of the NOM. The NOM characteristic modification corresponding to solution property could influence the interactions between the NOM and pyrene.Preozonation could destroy the aromatic or hydrophobic structures of the NOM and decrease Koc of pyrene.

  17. Enhanced biodegradation of pyrene and indeno(1,2,3-cd)pyrene using bacteria immobilized in cinder beads in estuarine wetlands.

    Science.gov (United States)

    Huang, Ru-Ying; Tian, Wei-Jun; Liu, Qing; Yu, Hui-Bo; Jin, Xin; Zhao, Yang-Guo; Zhou, Yu-Hang; Feng, Gong

    2016-01-15

    Two strains (Pseudomonas taiwanensis PYR1 and Acinetobacter baumannii INP1) were isolated from PAH-contaminated Liaohe estuarine wetland using enrichment. The cells of PYR1 and INP1 were immobilized in cinder beads for pyrene and indeno(1,2,3-cd)pyrene biodegradation in wetland. Biodegradation of pyrene and indeno(1,2,3-cd)pyrene in soils from wetland was carried out in pots using free cells as well as those immobilized in cinder beads to ascertain the role of bioaugmentation. Supported by the cinder beads, the immobilized cells degraded 70.7% and 80.9% of pyrene and indeno(1,2,3-cd)pyrene respectively after 30 days. While the free cells degraded only 58.2% and 55.3%. Additionally, microbial analysis with high-throughput sequencing revealed the changes of microbial communities in soil without and with cinder beads immobilized with strains. The result indicated that Gammaproteobacteria were dominant PAH-degrading groups during bioaugmentation. This effective approach can be used to treat other PAH-contaminated wetlands by immobilizing different species of bacteria in cinder beads.

  18. Biodegradation of phenanthrene and pyrene in compost-amended soil.

    Science.gov (United States)

    Yuan, Shaw Y; Su, Lai M; Chang, Bea V

    2009-06-01

    This study investigated the biodegradation of the polycyclic aromatic hydrocarbons (PAHs) phenanthrene and pyrene in compost and compost-amended soil. The degradation rates of the two PAHs were phenanthrene>pyrene. The degradation of PAH was enhanced when the two PAHs were present simultaneously in the soil. The addition of either of the two types of compost (straw and animal manure) individually enhanced PAH degradation. Compost samples were separated into fractions with various particle size ranges, which spanned 2-50 microm, 50-105 microm, 105-500 microm, and 500-2000 microm. We observed that the compost fractions with smaller particle sizes demonstrated higher PAH degradation rates. However, when the different compost fractions were added to soil, compost particle size had no significant effect on the rate of PAH degradation. Of the micro-organisms isolated from the soil-compost mixtures, strains S1, S2, and S8, which were identified as Arthrobacter nicotianae, Pseudomonas fluorescens, and Bordetella Petrii, respectively, demonstrated the best degradation ability.

  19. Degradation of phenanthrene and pyrene in spiked soils by single and combined plants cultivation.

    Science.gov (United States)

    Cheema, Sardar Alam; Imran Khan, Muhammad; Shen, Chaofeng; Tang, Xianjin; Farooq, Muhammad; Chen, Lei; Zhang, Congkai; Chen, Yingxu

    2010-05-15

    The present study was conducted to investigate the capability of four plant species (tall fescue, ryegrass, alfalfa, and rape seed) grown alone and in combination to the degradation of phenanthrene and pyrene (polycyclic aromatic hydrocarbons, PAHs) in spiked soil. After 65 days of plant growth, plant biomass, dehydrogenase activity, water-soluble phenolic (WSP) compounds, plant uptake and accumulation and residual concentrations of phenanthrene and pyrene were determined. Our results showed that presence of vegetation significantly enhanced the dissipation of phenanthrene and pyrene from contaminated soils. Higher degradation rates of PAHs were observed in the combined plant cultivation (98.3-99.2% phenanthrene and 88.1-95.7% pyrene) compared to the single plant cultivation (97.0-98.0% phenanthrene and 79.8-86.0% pyrene). Contribution of direct plant uptake and accumulation of phenanthrene and pyrene was very low compared to the plant enhanced dissipation. By contrast, plant-promoted biodegradation was the predominant contribution to the remediation enhancement. The correlation analysis indicates a negative relation between biological activities (dehydrogenase activity and WSP compounds) and residual concentrations of phenanthrene and pyrene in planted soils. Our results suggest that phytoremediation could be a feasible choice for PAHs contaminated soil. Moreover, the combined plant cultivation has potential to enhance the process. Copyright (c) 2010 Elsevier B.V. All rights reserved.

  20. Dual partitioning and attachment effects of rhamnolipid on pyrene biodegradation under bioavailability restrictions.

    Science.gov (United States)

    Congiu, Eleonora; Parsons, John R; Ortega-Calvo, José-Julio

    2015-10-01

    We investigated the effects of different bioavailability scenarios on the rhamnolipid-enhanced biodegradation of pyrene by the representative polycyclic aromatic hydrocarbon degrader Mycobacterium gilvum VM552. This biosurfactant enhanced biodegradation when pyrene was provided in the form of solid crystals; no effect was observed when the same amount of the chemical was preloaded on polydimethylsiloxane (PDMS). An enhanced effect was observed when pyrene was sorbed into soil but not with the dissolved compound. Synchronous fluorescence spectrophotometry and liquid scintillation were used to determine the phase exchange of pyrene. We also investigated the phase distribution of bacteria. Our results suggest that the rhamnolipid can enhance the biodegradation of pyrene by micellar solubilization and increase diffusive uptake. These mechanisms increase substrate acquisition by bacterial cells at exposure concentrations well above the half-saturation constant for active uptake. The moderate solubilization of pyrene from PDMS by the rhamnolipid and the prevention of cell attachment may explain the lack of enhancement for pyrene-preloaded PDMS.

  1. Uptake and accumulation of phenanthrene and pyrene in spiked soils by Ryegrass( Lolium perenne L.)

    Institute of Scientific and Technical Information of China (English)

    XU Sheng-you; CHEN Ying-xu; LIN Qi; WU Wei-xiang; XUE Sheng-guo; SHEN Chao-feng

    2005-01-01

    Phytoremediation has long been recognized as a cost-effective method for the removal of polycyclic aromatic hydrocarbons (PAHs) from soil. A study was conducted to investigate the uptake and accumulation of PAHs in root and shoot of Lolium perenne L. Pot experiments were conducted with series of concentrations of 3.31-378.37 mg/kg for phenanthrene and those of 4.22-365.38 mg/kg for pyrene in a greenhouse. The results showed that both ryegrass roots and shoots did take up PAHs from spiked soils, and generally increased with increasing concentrations of PAH in soil. Bioconcentration factors(BCFs) of phenanthrene by shoots and roots were 0.24-4.25 and 0.17-2.12 for the same treatment. BCFs of pyrene by shoots were 0.20-1.5, except for 4.06 in 4.32 mg/kg treatment, much lower than BCFs of pyrene by roots (0.58-2.28). BCFs of phenanthrene and pyrene tended to decrease with increasing concentrations of phenanthrene and pyrene in soil. Direct uptake and accumulation of these compounds by Lolium perenne L. was very low compared with the other loss pathways, which meant that plant-promoted microbial biodegradation might be the main contribution to plant-enhanced removal of phenanthrene and pyrene in soil. However, the presence of Lolium perenne L. significantly enhanced the removal of phenanthrene and pyrene in spiked soil. At the end of 60 d experiment, the extractable concentrations of phenanthrene and pyrene were lower in planted soil than in non-planted soil, about 83.24%-91.98% of phenanthrene and 68.53%-84.10% of pyrene were removed from soils, respectively. The results indicated that the removal of PAHs in contaminated soils was a feasible approach by using Lolium perenne L.

  2. Uptake and elimination of benzo[a]pyrene in the terrestrial isopod Porcellio scaber.

    Science.gov (United States)

    van Brummelen, T C; van Straalen, N M

    1996-08-01

    In isopods from contaminated sites relatively low levels of high molecular weight polycyclic aromatic hydrocarbons (PAHs) have been observed, which may be caused by either a low bioavailability or a high elimination rate. To shed light on this, the uptake and elimination rates of benzo[a]pyrene were estimated for the isopod Porcellio scaber. The isopod was fed contaminated food (100 microg benzo[a]pyrene/g dwt) for seven weeks followed by four weeks of untreated food. The hindguts of the animals were removed prior to analysis to exclude food material from the body. Benzo[a]pyrene concentrations were log-normally distributed among the individuals. The high inter-individual variation in benzo[a]pyrene content could not be explained from differences in sex, the estimated amount of food in the hindgut, or the body weight. A one-compartment model fitted to the isopod concentrations estimated an assimilation rate of 2.9 microg benzo[a]pyrene/g dwt day, an elimination rate constant of 1.1/day and an equilibrium concentration of 2.5 microg benzo[a]pyrene/g dwt. According to the model 68% of the isopod population had an equilibrium concentration between 1.0 and 7.2 microg benzo[a]pyrene/g dwt day with a benzo[a]pyrene half-life ranging between 0.4 and 1.3 days. The assimilation efficiency was estimated at 20 to 40% of the ingested benzo[a]pyrene. The tissue distribution of benzo[a]pyrene was investigated in a separate experiment. Trace levels of benzo[a]pyrene were detected in haemolymph samples, demonstrating absorption and transport of the compound in the isopod. It is concluded that dietary benzo[a]pyrene is available for uptake to the isopod and that low residues of the compound observed in field isopods are the result of a high elimination rate rather than a reduced bioavailability. As PAHs from soil appear to be available to soil invertebrates, the widespread contamination of the soil from atmospheric emissions is of some concern, especially since the observed

  3. Solid-state NMR characterization of pyrene-cuticular matter interactions.

    Science.gov (United States)

    Sachleben, Joseph R; Chefetz, Benny; Deshmukh, Ashish; Hatcher, Patrick G

    2004-08-15

    One- and two-dimensional nuclear magnetic resonance (NMR) experiments were performed on Agave americana cutan and tomato cutin to examine the interactions between a hydrophobic pollutant, pyrene, and cuticular material. Variable-temperature NMR experiments show that cutan, an acid- and base-resistant cuticular biopolymer, undergoes the characteristic melting behavior of "polyethylene-like" crystallites, while the tomato cutin does not. The melting point of A. americana cutan was found to be approximately 360 K, which is consistent with the thickness of the polyethylene crystallites of 30-40 methylene units. Sorption models predict that the sorption behavior of hydrophobic pollutants should depend on the phase of the cuticular material. 13C NMR experiments on labeled pyrene were performed. The 13C T1 of pyrene decreases significantly from that of crystalline pyrene upon sorption to both tomato fruit cutin and A. americana cutan, indicating that the pyrene is mobile upon sorption. Magic angle spinning experiments at low spinning frequencies (2-4 kHz) provided the chemical shift anisotropy (CSA) parameters delta, the anisotropy, and eta, the asymmetry parameter, for crystalline and sorbed pyrene. For crystalline pyrene, two types of crystallographically distinctive pyrenes were observed. The first had delta = -97.4+/-0.5 ppm and eta = 0.934+/-0.006, while the second had delta = -98.1+/-0.5 ppm and eta = 0.823+/-0.008. After sorption to cutan, these CSA parameters were found to be delta = -78.9+/-5.3 ppm and eta < 0.70 independent of the length of time since completion of the sorption procedure. In tomato cutin, the CSA parameters were found to be dependent upon the time since completion of the sorption procedure. One and one-half months after sorption, delta was found to have a value of -30.4 ppm < delta < 0.0 ppm and eta was undeterminable, while after 22 months these values become delta = -80.0 +/-3.3 ppm and eta< 0.42. These changes in the CSA parameters

  4. Photophysical Study of Pyrene-labelled St/DVB Copolymers

    Institute of Scientific and Technical Information of China (English)

    何炳林; 王国昌; 李新松; 陈柳生; 杜金环

    1994-01-01

    The photophysical properties of a series of pyrene-labelled styrene/divinyl benzene (St/ DVB) copolymers have been studied for the first time by steady-state fluorescence spectra. The results indicate that when pyrenyl content (mol%) in the copolymer is lower than 0. 006% , the fluorescence spectra only show the pyrenyl monomer emission, while the 0-0 transition band is much suppressed and the vibronic structure is partially lost. However, in the fluorescence spectra of the copolymers with pyrenyl content higher than 0.3%, there appear some new emission bands at ca 420 nm, 440 nm and 475 nm. These results are explained in terms of the formation of ground-state and excited-state aggregates, which reveals the heterogeneity of the crosslinked networks.

  5. Crystal structure of 2-(thiophen-3-ylethyl pyrene-1-carboxylate

    Directory of Open Access Journals (Sweden)

    Bianca X. Valderrama-García

    2015-12-01

    Full Text Available In the title compound, C23H16O2S, the thiophene group is rotationally disordered into two fractions almost parallel to each other, with occupation factors of 0.523 (7 and 0.477 (7, and subtending dihedral angles of 10.5 (5 and 9.3 (5°, respectively, to the thiophene group. The molecules are held together by weak C—H...O and C—H...π hydrogen bonds, producing a laminar arrangement, which are further connected in a perpendicular fashion by S...π contacts [S...centroid = 3.539 (8 and 3.497 (8 Å]. In spite of the presence of the entended pyrene group, the structure does not present any parallel π–π stacking interactions. The structure was refined as an inversion twin.

  6. Carcinogenicity of the environmental pollutants cyclopenteno-(cd)pyrene and cyclopentano(cd)pyrene in mouse skin

    Energy Technology Data Exchange (ETDEWEB)

    Cavalieri, E.; Rogan, E.; Toth, B.; Munhall, A.

    1981-01-01

    Cyclopenteno(cd)pyrene (CPEP) is a widespread environmental pollutant. This hydrocarbon and its 3,4-dihydro derivative, cyclopentano(cd)pyrene (CPAP), were tested on skin in a two-stage initiation-promotion experiment in CD-1 mice and by repeated application in Swiss mice. The biological effect of CPEP and CPAP was compared to that of benzo(a)-pyrene (BP). Nine-week-old female CD-1 mice in groups of 30 were treated every other day over a 20-day period at mini-dose levels of 0.18, 0.06 and 0.02 mumol of CPEP or CPAP in acetone. One group was treated with BP at the low mini-dose level. Initiation was followed by twice weekly application of tetradecanoyl phorbol acetate for 40 weeks. In the second experiments, nine-week-old female Swiss mice in groups of 30 were treated at dose levels of 1.8, 0.6 and 0.2 mumol CPEP or CPAP in acetone twice weekly for 30 weeks. One group was treated with BP at the low dose. CPAP was virtually inactive in both studies. In the initiation-promotion experiment CPEP was inactive at the low dose level, whereas BP exhibited significant tumorigenicity. At the medium and high doses CPEP showed weak, but statistically insignificant, tumorigenic activity. Repeated application of CPEP at the high, medium and low doses resulted in tumor incidences of 23, 37 and 57%, respectively. This reverse dose-response may be due to the relatively high cytotoxicity of CPEP, BP, which was compared to CPEP at the low dose, elicited tumors in 100% of the mice. Most of the CPEP-induced neoplasms were malignant and some metastasized to lungs and lymph nodes. The inactivity of CPAP suggests the carcinogenicity of CPEP is probably due to formation of the ultimate metabolite CPEP 3,4-oxide. In view of the abundance of CPEP in environmental and occupational pollutants, its moderately potent carcinogenicity may represent a potential health hazard.

  7. Influence of tea saponin on enhancing accessibility of pyrene and cadmium phytoremediated with Lolium multiflorum in co-contaminated soils.

    Science.gov (United States)

    Wang, Qian; Liu, Xiaoyan; Zhang, Xinying; Hou, Yunyun; Hu, Xiaoxin; Liang, Xia; Chen, Xueping

    2016-03-01

    Tea saponin (TS), a kind of biodegradable surfactant, was chosen to improve the accessible solubilization of pyrene and cadmium (Cd) in co-contaminated soils cultivated Lolium multiflorum. TS obviously improved the accessibility of pyrene and Cd for L. multiflorum to accelerate the process of accumulation and elimination of the pollutants. The chemical forms of Cd was transformed from Fe-Mn oxides and associated to carbonates fractions into exchangeable fractions by adding TS in single Cd and pyrene-Cd contaminated soils. Moreover, the chemical forms of pyrene were transformed from associated fraction into bioaccessible fraction by adding TS in pyrene and pyrene-Cd contaminated soils. In pyrene-Cd contaminated soil, the exchangeable fraction of Cd was hindered in the existence of pyrene, and bioaccessible fraction of pyrene was promoted by the cadmium. Besides, in the process of the pyrene degradation and Cd accumulation, the effect could be improved by the elongation of roots with adding TS, and the microorganism activity was stimulated by TS to accelerate the removal of pollutions. Therefore, Planting L. multiflorum combined with adding TS would be an effective method on the phytoremediation of organics and heavy metals co-contaminated soils.

  8. Mineralization of pyrene induced by interaction between Ochrobactrum sp. PW and ryegrass in spiked soil.

    Science.gov (United States)

    Liu, Tuo; Wei, Lianshuang; Qiao, Min; Zou, Dexun; Yang, Xiaojin; Lin, Aijun

    2016-11-01

    This study was conducted to investigate the capability of pyrene-degrading bacterium Ochrobactrum sp. PW and ryegrass (Lolium multiflorum) grown alone and in combination on the degradation of pyrene in soil. After 60 days of ryegrass growth, plant biomass, pyrene-degrading microbial mass, soil enzyme activity (catalase activity and polyphenol oxidase activity) and residual concentration of pyrene in soils were determined. Higher dissipation rates were observed in PW inoculation treatments: ryegrass+PW rhizosphere soil (RP-r) and ryegrass+PW non-rhizosphere soil (RP-nr), than planting of ryegrass alone, rhizosphere (R-r) or non-rhizosphere (R-nr). The inoculation with PW significantly (psoil. Our results suggest that adding of PAHs-degrading bacteria to soil can enhance remediation of PAHs contaminated soil, while improving plant growth.

  9. Optimized cultivation of highly-efficient degradation bacterial strains and their degradation ability towards pyrene

    Institute of Scientific and Technical Information of China (English)

    HOU Shuyu; ZHANG Qingmin; DUO Miao; ZHANG Yang; SUN Hongwen

    2007-01-01

    Two bacterial strains,Pyl and Py4,have been tamed and isolated through long cultivation with polycyclic aromatic hydrocarbon-pyrene as the single carbon source.It has been proven that they are both highly-efficient pyrene degrading bacteria and both Bacillus sp..The pyrene degradation ability of separated Pyl,Py4 and the consortium of equal Pyl and Py4 was studied in this project.It is shown that pyrene degradation rates were 88% in 10hr by Py1,84% in 14hr by Py4,and 88% in 8hr by the consortium.It was also determined that the best degradation temperatures were 37℃ and pH 7.0 respectively.The influence of different nutrient substrates added in the degradation experiments was also studied.It was shown that sodium salicylate,sodium acetate and yeast exuact had obvious simulative effect,but glucose had no obvious effect.

  10. Effect of pyrene and cadmium on microbial activity and community structure in soil.

    Science.gov (United States)

    Lu, Mang; Xu, Kui; Chen, Jun

    2013-04-01

    In this study, a greenhouse experiment was conducted to investigate interactive effects of cadmium (Cd) × pyrene × plant treatments on soil microbial activity and community structure. The results demonstrated that the basal respiration, microbial biomass carbon and metabolic quotient in both unplanted and rhizosphere soil were significantly influenced by interaction of Cd and pyrene. The combined application of Cd and pyrene caused a significantly greater biocidal influence on the soil microorganisms than the single spiking of Cd or pyrene. The soil basal respiration increased with the spiking of 2.5 mg kg(-1) Cd in both unplanted and rhizosphere soil. The eco-physiological index of Cd-tolerant populations was significantly different among the unplanted soil, rhizoplane and rhizosphere soil of tall fescue, indicating a slightly uneven distribution of fast- and slow-growing tolerant bacteria. Obvious differences in microbial activity were observed among treatments due to different physicochemical characteristics of the rhizosphere soils depending on the plant species.

  11. Effect of sunlight irradiation on photocatalytic pyrene degradation in contaminated soils by micro-nano size TiO2.

    Science.gov (United States)

    Chang Chien, S W; Chang, C H; Chen, S H; Wang, M C; Madhava Rao, M; Satya Veni, S

    2011-09-01

    The enhanced catalytic pyrene degradation in quartz sand and alluvial and red soils by micro-nano size TiO(2) in the presence and absence of sunlight was investigated. The results showed that the synergistic effect of sunlight irradiation and TiO(2) was more efficient on pyrene degradation in quartz sand and red and alluvial soils than the corresponding reaction system without sunlight irradiation. In the presence of sunlight irradiation, the photooxidation (without TiO(2)) of pyrene was very pronounced in alluvial and red soils and especially in quartz sand. However, in the absence of sunlight irradiation, the catalytic pyrene degradation by TiO(2) and the photooxidation (without TiO(2)) of pyrene were almost nil. This implicates that ultra-violet (UV) wavelength range of sunlight plays an important role in TiO(2)-enhanced photocatalytic pyrene degradation and in photooxidation (without TiO(2)) of pyrene. The percentages of photocatalytic pyrene degradation by TiO(2) in quartz sand, alluvial and red soils under sunlight irradiation were 78.3, 23.4, and 31.8%, respectively, at 5h reaction period with a 5% (w/w) dose of the amended catalyst. The sequence of TiO(2)-enhanced catalytic pyrene degradation in quartz sand and alluvial and red soils was quartz sand>red soil>alluvial soil, due to different texture and total organic carbon (TOC) contents of the quartz sand and other two soils. The differential Fourier transform infrared (FT-IR) spectra of degraded pyrene in alluvial soil corroborate that TiO(2)-enhanced photocatalytic degradation rate of degraded pyrene was much greater than photooxidation (without TiO(2)) rate of degraded pyrene. Based on the data obtained, the importance for the application of TiO(2)-enhanced photocatalytic pyrene degradation and associated organic contaminants in contaminated soils was elucidated.

  12. Wheat bran and the induction of intestinal benzo(a)pyrene hydroxylase by dietary benzo(a)pyrene.

    Science.gov (United States)

    Clinton, S K; Visek, W J

    1989-03-01

    The mucosa of the intestine responds to polycyclic aromatic hydrocarbons (PAH) with the rapid induction of benzo(a)pyrene hydroxylase (BPH). Studies were conducted to determine if dietary fiber would reduce exposure of the intestine to dietary benzo(a)pyrene (BP) as indicated by intestinal BPH activity. In all studies, female Sprague-Dawley rats were fed a fiber-free purified diet for 7 d, whereupon they were switched to experimental diets for 48 h. After 48 h their small intestinal mucosa was assayed for BPH activity. Diets for the initial study contained 0, 100, 400, 800, or 1200 mg BP/kg diet, each with and without 10% soft white wheat bran. Enzyme induction with 100 and 400 mg BP/kg diet was partially inhibited by bran, but with higher concentrations of BP there was no protective effect. The inhibition in BP-induced intestinal BPH activity was observed with 10% wheat bran but not with 3.3 or 6.6%. Subsequent studies showed no significant inhibition in BPH induction with cellulose or lignin, whereas all forms of wheat bran (hard red, soft white, or finely ground soft white) caused significant inhibition. In the final study, a diet containing charcoal-broiled beef, a known source of PAH, was compared with diets containing raw beef or soybean protein, each with and without 10% soft white wheat bran. BPH activity remained low with raw beef and soybean protein whether or not fiber was added. However, intestinal BPH activity was raised ninefold by charcoal-broiled beef. The addition of bran reduced BPH activity to 65% of that observed with the fiber-free, charcoal-broiled beef diet.(ABSTRACT TRUNCATED AT 250 WORDS)

  13. Surfactant enhanced pyrene degradation in the rhizosphere of tall fescue (Festuca arundinacea).

    Science.gov (United States)

    Cheema, Sardar Alam; Khan, Muhammad Imran; Tang, Xianjin; Shen, Chaofeng; Farooq, Muhammad; Chen, Yingxu

    2016-09-01

    The present study was conducted to evaluate the effect of two non ionic surfactants (Tween 80 and Triton X-100), a biosurfactant (Lecithin), and randomly methylated-β-cyclodextrins (RAMEB) on the remediation of pyrene from soil planted with tall fescue (Festuca arundinacea). Soils with pyrene concentration of about 243 mg kg(-1) was grown with tall fescue and were individually amended with 0, 200, 600, 1000, and 1500 mg kg(-1) of Tween 80, Triton X-100, biosurfactant, and RAMEB. The results show that all surfactants significantly increased plant biomass compared to unamended soil. Dehydrogenase activity was also stimulated as a result of surfactant addition. Only 3.9 and 3.2 % of pyrene was decreased in the uncovered and covered abiotic sterile control, suggesting that microbial degradation was the main removal mechanism of pyrene from soil. In the planted treatment receiving no surfactant, the remediation of pyrene was 45 % which is significantly higher than that of corresponding unplanted control soil, suggesting that the cultivation of tall fescue alone could enhance the overall remediation of pyrene in soil. All surfactants had significantly higher rates of pyrene remediation compared to the unamended planted soil. Generally, RAMEB displayed the highest remediation rates, i.e., 64.4-79.1 % followed by the Triton X-100, i.e., 60.1-74.8 %. The positive impact of surfactants on pyrene remediation could possibly be because of their capacities to increase its bioavailability in soil. The evidence from this study suggests that the addition of surfactants could enhance phytoremediation of PAHs polluted soil.

  14. Topological, functional, and dynamic properties of the protein interaction networks rewired by benzo(a)pyrene

    Energy Technology Data Exchange (ETDEWEB)

    Ba, Qian [Key Laboratory of Food Safety Research, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai (China); Key Laboratory of Food Safety Risk Assessment, Ministry of Health, Beijing (China); Li, Junyang; Huang, Chao [Key Laboratory of Food Safety Research, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai (China); Li, Jingquan; Chu, Ruiai [Key Laboratory of Food Safety Research, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai (China); Key Laboratory of Food Safety Risk Assessment, Ministry of Health, Beijing (China); Wu, Yongning, E-mail: wuyongning@cfsa.net.cn [Key Laboratory of Food Safety Risk Assessment, Ministry of Health, Beijing (China); Wang, Hui, E-mail: huiwang@sibs.ac.cn [Key Laboratory of Food Safety Research, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai (China); Key Laboratory of Food Safety Risk Assessment, Ministry of Health, Beijing (China); School of Life Science and Technology, ShanghaiTech University, Shanghai (China)

    2015-03-01

    Benzo(a)pyrene is a common environmental and foodborne pollutant that has been identified as a human carcinogen. Although the carcinogenicity of benzo(a)pyrene has been extensively reported, its precise molecular mechanisms and the influence on system-level protein networks are not well understood. To investigate the system-level influence of benzo(a)pyrene on protein interactions and regulatory networks, a benzo(a)pyrene-rewired protein interaction network was constructed based on 769 key proteins derived from more than 500 literature reports. The protein interaction network rewired by benzo(a)pyrene was a scale-free, highly-connected biological system. Ten modules were identified, and 25 signaling pathways were enriched, most of which belong to the human diseases category, especially cancer and infectious disease. In addition, two lung-specific and two liver-specific pathways were identified. Three pathways were specific in short and medium-term networks (< 48 h), and five pathways were enriched only in the medium-term network (6 h–48 h). Finally, the expression of linker genes in the network was validated by Western blotting. These findings establish the overall, tissue- and time-specific benzo(a)pyrene-rewired protein interaction networks and provide insights into the biological effects and molecular mechanisms of action of benzo(a)pyrene. - Highlights: • Benzo(a)pyrene induced scale-free, highly-connected protein interaction networks. • 25 signaling pathways were enriched through modular analysis. • Tissue- and time-specific pathways were identified.

  15. Effect of anionic-nonionic mixed surfactant on ryegrass uptake of phenanthrene and pyrene from water

    Institute of Scientific and Technical Information of China (English)

    SUN Lu; ZHU LiZhong

    2009-01-01

    The effect of anionic-nonionic mixed surfactant (SDBS-TX100) on the uptake of phenanthrene and pyrene by ryegrass in a hydroponic system was studied, and the influence factors including the com-positions and concentrations of mixed surfactants and the compounds properties were also discussed. The results showed that SDBS-TX100 mixtures with certain compositions and concentrations could enhance the uptake of phenanthrene and pyrene by ryegrass, which could be attributed to the im-proved uptake capacity of ryegrass roots for phenanthrene and pyrene. SDBS-TX100 can enhance the uptake of phenanthrene and pyrene by ryegrass in a wider range of surfactant concentrations (0-0.8 mmol/L) in comparison with corresponding single surfactants, and the maximal contents of phenan-threne and pyrene in ryegrass roots were obtained with the concentrations of SDBS-TX100 around the corresponding critical micelle concentrations. The uptake of phenanthrene and pyrene by ryegrass increased with the increasing mole fraction of SDBS in mixed surfactant solutions, and SDBS-TX100 mixture with a mole ratio of SDBS to TX100 at 9:1 had the greatest capacity in enhancing the uptake of phenanthrene and pyrene, at which the corresponding maximal concentrations of phenanthrene and pyrene in ryegrass roots were 216 and 8.16 times those without surfactants, respectively. Results from this study indicate that the anionic-nonionic mixed surfactants (SDBS-TX100) would be a preferred selection for the application of surfactant-enhanced phytoremediation technology to contaminated soils.

  16. Evident bacterial community changes but only slight degradation when polluted with pyrene in a red soil

    Directory of Open Access Journals (Sweden)

    Gaidi eRen

    2015-01-01

    Full Text Available Understanding the potential for PAH degradation by indigenous microbiota and the influence of PAHs on native microbial communities is of great importance for bioremediation and ecological evaluation. Various studies have focused on the bacterial communities in the environment where obvious PAH degradation was observed, little is known about the microbiota in the soil where poor degradation was observed. Soil microcosms were constructed with a red soil by supplementation with a high-molecular-weight PAH (pyrene at three dosages (5, 30, and 70 mg.kg-1. Real-time PCR was used to evaluate the changes in bacterial abundance and pyrene dioxygenase gene (nidA quantity. Illumina sequencing was used to investigate changes in diversity, structure, and composition of bacterial communities. After 42 days of incubation, no evident degradation was observed. The poor degradation ability was associated with the stability or significant decrease of abundance of the nidA gene. Although the abundance of the bacterial 16S rRNA gene was not affected by pyrene, the bacterial richness and diversity were decreased with increasing dosage of pyrene and the community structure was changed. Phylotypes affected by pyrene were comprehensively surveyed: (1 at the high taxonomic level, seven of the abundant phyla/classes (relative abundance >1.0% including Chloroflexi, AD3, WPS-2, GAL5, Alphaproteobacteria, Actinobacteria, and Deltaproteobacteria and one rare phylum Crenarchaeota were significantly decreased by at least one dosage of pyrene, while 3 phyla/classes (Acidobacteria, Betaproteobacteria, and Gammaproteobacteria were significantly increased; and (2 at the lower taxonomic level, the relative abundances of twelve orders were significantly depressed, whereas those of nine orders were significantly increased. This work enhanced our understanding of the biodegradation potential of pyrene in red soil and the effect of pyrene on soil ecosystems at the microbial community

  17. Protein Changes in Response to Pyrene Stress in Maize (Zea mays L.) Leaves

    Institute of Scientific and Technical Information of China (English)

    Sheng-You Xu; Ying-Xu Chen; Wei-Xiang Wu; Shao-Jian Zheng; Sheng-Guo Xue; Shi-Ying Yang; Yi-Jin Peng

    2007-01-01

    Phytoremediation is a relatively new approach to remove polycyclic aromatic hydrocarbons (PAHs) from the environment. When plants are grown under pyrene treatment, they respond by synthesizing a set of protective proteins. To learn more about protein changes in response to pyrene treatment, we extracted total proteins from the leaves of maize (Zea mays L.) 1 week after pyrene treatment. The proteins extracted were separated with twodimensional gel electrophoresis. In total, approximately 54 protein spots were found by comparing gels from treated and control groups. According to the isoelectric point, molecular weight, and abundance of these protein spots, 20 pyrene-induced proteins were found to have changed abundance. Of these, 15 protein spots were increased and five protein spots were newly appeared in pyrene-treated plant leaves. Six model upregulated protein spots of different molecular weights were excised from the gels and subjected to trypsin digestion followed by peptide separation using matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Peptlde masses were used to search the matrix-science database for protein identification. Two of the proteins were identified on the basis of the homology of their peptide profiles with existing protein sequences as pyruvate orthophosphate dikinase and the rlbulose-1,5-bisphosphate carboxylase/oxygenase large subunit. These proteins are involved in the regulation of carbohydrate and energy metabolism. The present study gives new insights into the pyrene stress response in maize leaves and demonstrates the power of the proteomlc approach in phytoremediation of PAHs.

  18. Biochemical response of anthracene and benzo [a] pyrene in milkfish Chanos chanos.

    Science.gov (United States)

    Palanikumar, L; Kumaraguru, A K; Ramakritinan, C M; Anand, M

    2012-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are common toxic pollutants found in the aquatic environment, and the assessment of their impact on biota is of considerable concern. The aim of the present research was to study the acute toxicity, bioaccumulation and biochemical response of milkfish Chanos chanos (Forsskal) to two selected PAHs: anthracene and benzo [a] pyrene. Acute toxicity test results were evaluated by the Probit analysis method and 96h LC(50) values for C. chanos exposed to anthracene was 0.030mgl(-1) and 0.014mgl(-1) for benzo [a] pyrene. Bioaccumulation concentration of anthracene was high when compared to benzo [a] pyrene. Biomarkers indicative of neurotoxicity (acetylcholinesterase, AchE), oxidative stress (lipid peroxidation, LPO and catalase, CAT) and phase II biotransformation of xenobiotics (glutathione S transferase, GST and reduced glutathione, GSH) were measured to assess effects of selected PAHs. Anthracene and benzo [a] pyrene increase LPO and CAT level of C. chanos suggesting that these PAHs may induce oxidative stress. Both the PAHs inhibited AchE indicating that they have at least one mechanism of neurotoxicity in common: the disruption of cholinergic transmission by inhibition of AChE. An induction of C. chanos glutathione S-transferase (GST) activity was found in fish exposed to benzo [a] pyrene, while an inhibition was observed after exposure to anthracene. These results suggest that GST is involved in the detoxification of benzo [a] pyrene, but not of anthracene.

  19. Benzo(a)pyrene diol epoxides as intermediates in nucleic acid binding in vivo and in vitro

    DEFF Research Database (Denmark)

    Weinstein, I.B.; Jeffrey, A.M.; Jennette, K.W.

    1976-01-01

    Evidence has been obtained that a specific isomer of a diol epoxide derivative of benzo(a)pyrene, (+/-)-7 beta,8alpha-dihydroxy-9alpha, 10alpha-epoxy-7,8,9,10-tetrahydrobenzo(a)pyrene, is an intermediate in the binding of benzo(a)pyrene to RNA in cultured bovine bronchial mucosa. An adduct is for...... is formed between position 10 of this derivative and the 2-amino group of guanine.......Evidence has been obtained that a specific isomer of a diol epoxide derivative of benzo(a)pyrene, (+/-)-7 beta,8alpha-dihydroxy-9alpha, 10alpha-epoxy-7,8,9,10-tetrahydrobenzo(a)pyrene, is an intermediate in the binding of benzo(a)pyrene to RNA in cultured bovine bronchial mucosa. An adduct...

  20. Evaluation of soil pH and moisture content on in-situ ozonation of pyrene in soils.

    Science.gov (United States)

    Luster-Teasley, S; Ubaka-Blackmoore, N; Masten, S J

    2009-08-15

    In this study, pyrene spiked soil (300 ppm) was ozonated at pH levels of 2, 6, and 8 and three moisture contents. It was found that soil pH and moisture content impacted the effectiveness of PAH oxidation in unsaturated soils. In air-dried soils, as pH increased, removal increased, such that pyrene removal efficiencies at pH 6 and pH 8 reached 95-97% at a dose of 2.22 mg O(3)/mg pyrene. Ozonation at 16.2+/-0.45 mg O(3)/ppm pyrene in soil resulted in 81-98% removal of pyrene at all pH levels tested. Saturated soils were tested at dry, 5% or 10% moisture conditions. The removal of pyrene was slower in moisturized soils, with the efficiency decreasing as the moisture content increased. Increasing the pH of the soil having a moisture content of 5% resulted in improved pyrene removals. On the contrary, in the soil having a moisture content of 10%, as the pH increased, pyrene removal decreased. Contaminated PAH soils were stored for 6 months to compare the efficiency of PAH removal in freshly contaminated soil and aged soils. PAH adsorption to soil was found to increase with longer exposure times; thus requiring much higher doses of ozone to effectively oxidize pyrene.

  1. Lack of contribution of covalent benzo[a]pyrene-7,8-quinone-DNA adducts in benzo[a]pyrene-induced mouse lung tumorigenesis

    Science.gov (United States)

    Benzo[a]pyrene (B[a]P) is a potent human and rodent lung carcinogen. This activity has been ascribed in part to the formation of anti-trans-B[a]P-7,8-diol-9,10-epoxide (BPDE)-DNA adducts. Other carcinogenic mechanisms have been proposed: 1.] The induction of apurinic sites from r...

  2. (E-2-[(Pyren-1-yliminomethyl]quinolin-8-ol

    Directory of Open Access Journals (Sweden)

    Soma Mukherjee

    2016-04-01

    Full Text Available In the title compound, C26H16N2O, the pyrene ring system (r.m.s. deviation = 0.021 Å is inclined to the planar quinoline ring system (r.m.s. deviation = 0.017 Å by 30.62 (5°, and the conformation about the bridging N=C bond is E. There is an intramolecular O—H...N hydrogen bond with an S(5 ring motif present. In the crystal, molecules are linked by pairs of C—H...O hydrogen bonds, forming inversion dimers with an R22(14 ring motif, flanked by two R21(7 ring motifs. The dimers stack along the b axis with slipped parallel π–π interactions involving neighbouring molecules; the shortest π–π interaction involves aromatic rings of the quinoline ring system [inter-centroid distance = 3.6267 (11 Å].

  3. Isolation and Identification of Pyrene Mineralizing Mycobacterium spp. from Contaminated and Uncontaminated Sources

    Directory of Open Access Journals (Sweden)

    Christopher W. M. Lease

    2011-01-01

    Full Text Available Mycobacterium isolates obtained from PAH-contaminated and uncontaminated matrices were evaluated for their ability to degrade three-, four- and five-ring PAHs. PAH enrichment studies were prepared using pyrene and inocula obtained from manufacturing gas plant (MGP soil, uncontaminated agricultural soil, and faeces from Macropus fuliginosus (Western Grey Kangaroo. Three pyrene-degrading microorganisms isolated from the corresponding enrichment cultures had broad substrate ranges, however, isolates could be differentiated based on surfactant, phenol, hydrocarbon and PAH utilisation. 16S rRNA analysis identified all three isolates as Mycobacterium sp. The Mycobacterium spp. could rapidly degrade phenanthrene and pyrene, however, no strain had the capacity to utilise fluorene or benzo[a]pyrene. When pyrene mineralisation experiments were performed, 70–79% of added 14C was evolved as 14CO2 after 10 days. The present study demonstrates that PAH degrading microorganisms may be isolated from a diverse range of environmental matrices. The present study demonstrates that prior exposure to PAHs was not a prerequisite for PAH catabolic activity for two of these Mycobacterium isolates.

  4. Preliminary screening of co-substrates for bioremediation of pyrene-contaminated soil through composting.

    Science.gov (United States)

    Sayara, Tahseen; Sarrà, Montserrat; Sánchez, Antoni

    2009-12-30

    The feasibility of using different organic amendments of different origin and properties in the bioremediation of pyrene-contaminated soil by means of composting has been tested. The selected pyrene concentration was 1g of pyrene per kg of dry soil. The organic amendments used include: raw organic fraction of municipal solid wastes (OFMSW), industrial compost from OFMSW composting (COFMSW), compost derived from home composting of OFMSW (HCOFMSW), anaerobically digested sludge (ADS), non-digested activated sludge (NDS) and centrifuged non-digested activated sludge (CNDS). The degradation rate was related to the amendment properties that directly affected the composting process. Raw OFMSW was not capable to enhance pyrene degradation in comparison to control, but stable HCOFMSW exhibited the highest removal rate (69%). The amendments stability and the temperatures reached as a consequence influenced the process, and thermophilic temperatures showed an inhibition effect on the microbial activity related to pyrene degradation. Some of the tested wastes need to be further investigated to find inexpensive organic amendments for soil bioremediation.

  5. [Preparation and characterization of the recombinant protein containing immunomimetic peptide of benzo[a]pyrene].

    Science.gov (United States)

    Apal'ko, S V; Lunin, V G; Filipenko, M L; Matveeva, V A; Liashchuk, A M; Lavrova, N V; Sherina, E A; Aver'ianov, A V; Kostianko, M V; Glushkov, A N

    2011-01-01

    Two recombinant plasmids were constructed. The first plasmid contained the hybrid gene composed of immunomimetic peptide of benzo[a]pyrene, of the protein pIII of bacteriophage M13 and of cellulose binding domain encoding sequences. The second plasmid contained the hybrid gene composed of the signal peptide of the protein pIII of bacteriophage M13, of immunomimetic peptide of benzo[a]pyrene, of the protein pill of bacteriophage M13 and of cellulose binding domain sequences. The obtained recombinant plasmids were used in expression of chimeric protein containing immunomimetic peptide ofbenzo[a]pyrene based on strain E. coli M15. The lack of the recombinant protein expression using first plasmid was demonstrated. In the same time, it was shown that accumulation of recombinant protein contained immunomimetic peptide with signal peptide of the protein pIIIl of bacteriophage was present. This chimeric protein was produced in "mature" (without signal peptide) and "unprocessing" (with signal peptide) forms. Using the Western-blot analysis, it was shown that the "mature" form only specifically bound to the B2 monoclonal antibody against benzo[a]pyrene. Thus, we expressed, purified, and characterized the recombinant protein containing immunomimetic peptide of benzo[a]pyrene.

  6. Benzo(a)pyrene induced structural and functional modifications in lung cystatin.

    Science.gov (United States)

    Khan, Mohd Shahnawaz; Priyadarshini, Medha; Shah, Aaliya; Tabrez, Shams; Jagirdar, Haseeb; Alsenaidy, Abdulrahman M; Bano, Bilqees

    2013-10-01

    Cystatins are thiol proteinase inhibitors ubiquitously present in the mammalian body. They serve a protective function to regulate the activities of endogenous proteinases, which may cause uncontrolled proteolysis and damage. In the present study, the effect of benzo(a)pyrene [BaP] on lung cystatin was studied to explore the hazardous effects of environmental pollutant on structural and functional integrity of the protein. The basic binding interaction was studied by UV-absorption, FT-IR, and fluorescence spectroscopy. The enhancement of total protein fluorescence with a red shift of 5 nm suggests structural scratch of lung cystatin by benzo(a)pyrene. Further, ANS binding studies reaffirm the unfolding of the thiol protease inhibitor (GLC-I) after treating with benzo(a)pyrene. The results of FT-IR spectroscopy reflect perturbation of the secondary conformation (alpha-helix to β-sheet) in goat lung cystatin on interaction with BaP. Finally, functional inactivation of cystatin on association with BaP was checked by its papain inhibitory activity. Benzo(a)pyrene (10 μM) caused complete inactivation of goat lung cystatin. Benzo(a)pyrene-induced loss of structure and function in the thiol protease inhibitor could provide a caution for lung injury caused by the pollutants and smokers.

  7. The use of proteomic analysis for exploring the phytoremediation mechanism of Scirpus triqueter to pyrene.

    Science.gov (United States)

    Zhang, Xinying; Liu, Xiaoyan; Chai, Wenbo; Wei, Jing; Wang, Qian; Li, Beibei; Li, Hongbing

    2013-09-15

    Scirpus triqueter has been reported to be an effective phytoremediation plant for pyrene dissipation. The study of S. triqueter in response to pyrene is crucial to understand the mechanism of phytoremediation. To gain a certain extent understanding of S. triqueter in response to pyrene, S. triqueter seedlings were exposed to 50 mg kg(-1) pyrene and a comparative proteomic analysis of total proteins was performed. 37 and 55 proteins were significantly differentially expressed in the shoot and root of S. triqueter upon exposure, respectively. 24 proteins (17 proteins in shoot and 7 proteins in root) were identified on the basis of the homology of their peptide profiles with existing protein sequences using mass spectrometry analysis. Analysis of protein expression patterns revealed that proteins in shoot associated with photosynthesis, defense, energy and matter metabolism, coenzyme metabolism and protein metabolism. Moreover, the proteins related photosynthesis accounted for more than 70% of the identified proteins. The proteins in root associated with stress, defense, energy metabolism, protein modification and carbohydrate metabolism. Pyrene appears to have an important deleterious effect on primary carbon metabolism, the synthesis of proteins and signal transduction. The present study demonstrates the use of proteomic approach to help us understand the phytoremediation mechanism of S. triqueter.

  8. Mutations Induced by Benzo[a]pyrene and Dibenzo[a,l]pyrene in lacI Transgenic B6C3F1 Mouse Lung Result from Stable DNA Adducts

    Science.gov (United States)

    Dibenzo[a,l]pyrene (DB[a,l]P) and benzo[a]pyrene (B[a]P) are carcinogenic polycyclic aromatic hydrocarbons (PAH) that are each capable of forming a variety of covalent adducts with DNA. Some of the DNA adducts formed by these PAHs have been demonstrated to spontaneously depurina...

  9. DIBENZO[A,L]PYRENE INDUCTION OF ERYTHROCYTE MICRONUCLEI IN A/J AND P53-DEFICIENT MICE

    Science.gov (United States)

    DIBENZO[a,l]PYRENE INDUCTION OF ERYTHROCYTE MICRONUCLEI IN AlJ AND P53-DEFICIENT MICE Male A/J and C57Bl/6 background p53+/+, p53+/- and p53-/- mice were treated with dibenzo[a,l]pyrene (DB[a,l]P), and micronucleus (MN) frequencies were measured in erythrocytes from bone ...

  10. Biodegradation of pyrene by Phanerochaete chrysosporium and enzyme activities in soils: effect of SOM, sterilization and aging.

    Science.gov (United States)

    Wang, Cuiping; Sun, Hongwen; Liu, Haibin; Wang, Baolin

    2014-05-01

    The impacts of soil organic matter (SOM), aging and sterilization on the production of lignin peroxidase (LiP) and manganese peroxidase (MnP) by Phanerochaete chrysosporium during the biodegradation of pyrene in soils were investigated. The biodegradation of pyrene by P. chrysosporium decreased with increasing SOM content, whereas the maximum activities of LiP and MnP increased, which indicates that SOM outweighed pyrene in controlling enzyme production. Sterilization enhanced the degradation of pyrene due to the elimination of competition from indigenous microbes, whereas aging led to a reduction in the degradation of pyrene primarily through changes in its sorbed forms. Both sterilization and aging could reduce SOM content and alter its structure, which also influenced the bioavailability of pyrene and the enzyme activity. The sterilization and aging processes caused changes in the degradation of pyrene, and the enzyme activities were greater in soils with high SOM contents. MnP was related to the degradation of pyrene to a greater extent, whereas LiP was more related to the decomposition of SOM.

  11. Lithography based on memory effects resulting from photoinduced self-assembly of pyrene dimers in thin polymer films

    NARCIS (Netherlands)

    Ivan, M.G.; Scaiano, J.C.

    2009-01-01

    Pulsed laser irradiation of pyrene in thin films through lithographic masks leads to blue fluorescent images characteristic of pyrene excimer emission. The images are stable at room temperature and are readily observable using fluorescence microscopy. For a constant energy dose, the images are stron

  12. Synthesis, hybridization and fluorescence properties of a 2'-C-pyrene-triazole modified arabino-uridine nucleotide

    DEFF Research Database (Denmark)

    Kumar, Pawan; Sharma, Pawan K.; Nielsen, Poul

    2017-01-01

    A new pyrene-modified nucleotide monomer is introduced, wherein pyrene is attached to the 2'-position of arabino-uridine through a triazolemethyl linker. When the monomer is introduced into oligonucleotides, very stable DNA duplexes and three way junctions are obtained. An oligonucleotide featuri...

  13. Studying Flocculation Mechanism of Chitosan with Pyrene-fluores-cence Probe Method

    Institute of Scientific and Technical Information of China (English)

    吴重亮; 陈亮; 陈东辉

    2003-01-01

    A peak/ratio in pyrene-fluorescence spectrum was employed to measure the polarity of micro-environment of chitosan adsorb-ing py--rene molecules. The authors have in the first time detect-ed the pyrene-fluorescence spectrum of chitosan with different degrees of deacetylation (D. D. ), and found the relationship between the flocculaflon of bentonite colloid by chitosan and the peak/ratio values of different molecular weight (M. W. ) and D .D. of chitosan. We find that M.W. plays a key role in the flocculatlon, but D.D. has limited effect on it. From micro-en-vironmental structure of view, it can be proved that the inter-particle bridging rather than charge neutralization dominates the flocculatlon with chitosan.

  14. Pyrene measurements in sooting low pressure methane flames by jet-cooled laser-induced fluorescence.

    Science.gov (United States)

    Wartel, M; Pauwels, J-F; Desgroux, P; Mercier, X

    2011-12-15

    This paper presents in detail the study we carried out concerning the pyrene measurement by jet-cooled laser-induced fluorescence (JCLIF) in different sooting low pressure methane flames. The aim of this paper is both to demonstrate the potentialities of this technique for the measurement of such moderately sized polycyclic aromatic hydrocarbons under sooting flame conditions and to provide new experimental data for the understanding and the development of chemical models of the soot formation processes. Several concentration profiles of pyrene measured in different sooting flame (various pressure and equivalence ratio) are presented. The validation of the JCLIF method for pyrene measurements is explained in detail as well as the calibration procedure, based on the standard addition method, which has been implemented for the quantification of the concentration profiles. Sensitivity lower than 1 ppb was obtained for the measurement of this species under sooting flame conditions.

  15. Formation of pyrene excimers in mesoporous ormosil thin films for visual detection of nitro-explosives.

    Science.gov (United States)

    Beyazkilic, Pinar; Yildirim, Adem; Bayindir, Mehmet

    2014-04-09

    We report the preparation of mesoporous thin films with bright pyrene excimer emission and their application in visual and rapid detection of nitroaromatic explosive vapors. The fluorescent films were produced by physically encapsulating pyrene molecules in the organically modified silica (ormosil) networks which were prepared via a facile template-free sol-gel method. Formation and stability of pyrene excimer emission were investigated in both porous and nonporous ormosil thin films. Excimer emission was significantly brighter and excimer formation ability was more stable in porous films compared to nonporous films. Rapid and selective quenching was observed in the excimer emission against vapors of nitroaromatic molecules; trinitrotoluene (TNT), dinitrotoluene (DNT), and nitrobenzene (NB). Fluorescence quenching of the films can be easily observed under UV light, enabling the naked-eye detection of nitro-explosives. Furthermore, excimer emission signal can be recovered after quenching and the films can be reused at least five times.

  16. Quantum chemistry and excited states: First investigations on pyrene-like molecules

    Science.gov (United States)

    Parisel, Olivier; Ellinger, Y.

    1994-01-01

    Although the calculations are expected to be accurate within 10%, it follows then that there cannot be proposed unquestionable one-to-one attribution due to the density of the DIB's (Diffuse Interstellar Bands). Nevertheless, it has been shown that if one is interested in the experimental study of methyl-pyrene cations, for example, then, the most promising candidate is the 1-methyl isomer: this isomer has been investigated by d'Hendecourt and Leger (1993,1994) and their spectrum shows very striking features in very good agreement with both our calculations and a few DIB's. However, 1-methyl-pyrene cation is not the only product susceptible of being formed in this experiment, and further investigations are in progress to give a complete interpretations of the results. This preliminary report on pyrene-like molecules illustrates the role that theoretical calculations can ply in both the design and the interpretation of experiments.

  17. Optical Sensing Properties of Pyrene-Schiff Bases toward Different Acids.

    Science.gov (United States)

    Babgi, Bandar A; Alzahrani, Asma

    2016-07-01

    A set of (4-substituted-phenyl)-pyren-1-ylmethylene-amine (PMA) was prepared by the reaction of pyrene-1-carboxaldehyde and the corresponding 4-substituted aniline. The structure of the PMA compounds were confirmed by spectroscopic data (IR, (1)HNMR, (13)CNMR, ISI-MS and elemental analysis. The structure of (4-bromo-phenyl)-pyren-1-ylmethylene-amine (BrPMA) was further confirmed by the single X-ray crystallography. The absorption and emission spectroscopic behaviors were investigated in variant acids. The compounds showed dramatic spectroscopic changes upon acidifying with strong acids and negligible effects when weak acids are used in the acidifications. Hence, the PMA compounds can be used as sensors to distinguish between weak and strong acids.

  18. Electronic absorption spectra of protonated pyrene and coronene in neon matrixes.

    Science.gov (United States)

    Garkusha, Iryna; Fulara, Jan; Sarre, Peter J; Maier, John P

    2011-10-13

    Protonated pyrene and coronene have been isolated in 6 K neon matrixes. The cations were produced in the reaction of the parent aromatics with protonated ethanol in a hot-cathode discharge source, mass selected, and co-deposited with neon. Three electronic transitions of the most stable isomer of protonated pyrene and four of protonated coronene were recorded. The strongest, S(1) ← S(0) transitions, are in the visible region, with onset at 487.5 nm for protonated pyrene and 695.6 nm for protonated coronene. The corresponding neutrals were also observed. The absorptions were assigned on the basis of ab initio coupled-cluster and time-dependent density functional theory calculations. The astrophysical relevance of protonated polycyclic aromatic hydrocarbons is discussed.

  19. Supercritical fluid extraction of vapor-deposited pyrene from carbonaceous coal stack ash.

    Science.gov (United States)

    Mauldin, R F; Vienneau, J M; Wehry, E L; Mamantov, G

    1990-11-01

    The efficiencies of extraction of vapor-deposited pyrene from a high-carbon coal stack ash by Soxhlet extraction with methanol, ultrasonic extraction with toluene, acid pretreatment and subsequent ultrasonic extraction with toluene, batch extraction with toluene, and supercritical fluid extraction (SFE) are compared. SFE using CO(2) or isobutane yielded extraction recoveries virtually identical with those obtained using ultrasonic or Soxhlet extraction processes. Collection of the SFE extract was performed by expansion into a solvent or onto the head of a gas chromatography (GC) column. No loss of extracted pyrene was observed upon collection of methanol-modified CO(2) SFE by expansion into methanol. Also, no loss of pure CO(2) SFE extract was observed upon collection on the head of a GC column. However, use of a methanol or toluene modifier for CO(2) SFE directly coupled to GC effected complete loss of extracted pyrene.

  20. Dual-mode fluorescence switching induced by self-assembly of well-defined poly(arylene ether sulfone)s containing pyrene and amide moieties.

    Science.gov (United States)

    Park, Jeyoung; Kim, Jisung; Seo, Myungeun; Lee, Jinhee; Kim, Sang Youl

    2012-11-04

    A new class of fluorescent organogelators, pyrene-containing poly(arylene ether sulfone)s, showed two fluorescence switching modes in different gelation solvents. The THF gel exhibited excimer emission due to dimerization of the pyrene groups. In contrast, excimer emission was quenched after gelation in MC because of stacking among the pyrene groups.

  1. Evaluation of the removal of pyrene and fluoranthene by Ochrobactrum anthropi, Fusarium sp. and their coculture.

    Science.gov (United States)

    Ortega-González, Diana K; Cristiani-Urbina, Eliseo; Flores-Ortíz, César M; Cruz-Maya, Juan A; Cancino-Díaz, Juan C; Jan-Roblero, J

    2015-01-01

    Fluoranthene and pyrene are polycyclic aromatic hydrocarbons of high molecular weight that are recalcitrant and toxic to humans; therefore, their removal from the environment is crucial. From hydrocarbon-contaminated soil, 25 bacteria and 12 filamentous fungi capable of growth on pyrene and fluoranthene as the sole carbon and energy source were isolated. From these isolates, Ochrobactrum anthropi BPyF3 and Fusarium sp. FPyF1 were selected and identified because they grew quickly and abundantly in both hydrocarbons. Furthermore, O. anthropi BPyF3 and Fusarium sp. FPyF1 were most efficient at removing pyrene (50.39 and 51.32 %, respectively) and fluoranthene (49.85 and 49.36 %, respectively) from an initial concentration of 50 mg L(-1) after 7 days of incubation. Based on this and on the fact that there was no antagonism between the two microorganisms, a coculture composed of O. anthropi BPyF3 and Fusarium sp. FPyF1 was formed to remove fluoranthene and pyrene at an initial concentration of 100 mg L(-1) in a removal kinetic assay during 21 days. Fluoranthene removal by the coculture was higher (87.95 %) compared with removal from the individual cultures (68.95 % for Fusarium sp. FPyF1 and 64.59 % for O. anthropi BPyF3). In contrast, pyrene removal by the coculture (99.68 %) was similar to that obtained by the pure culture of Fusarium sp. FPyF1 (99.75 %). The kinetics of removal for both compounds was adjusted to a first-order model. This work demonstrates that the coculture formed by Fusarium sp. FPyF1 and O. anthropi BPyF3 has greater potential to remove fluoranthene than individual cultures; however, pyrene can be removed efficiently by Fusarium sp. FPyF1 alone.

  2. Pyrene degradation in forest humus microcosms with or without pine and its mycorrhizal fungus.

    Science.gov (United States)

    Koivula, Teija T; Salkinoja-Salonen, Mirja; Peltola, Rainer; Romantschuk, Martin

    2004-01-01

    The mineralization potential of forest humus and the self-cleaning potential of a boreal coniferous forest environment for polycyclic aromatic hydrocarbon (PAH) compounds was studied using a model ecosystem of acid forest humus (pH = 3.6) and pyrene as the model compound. The matrix was natural humus or humus mixed with oil-polluted soil in the presence and absence of Scots pine (Pinus sylvestris L.) and its mycorrhizal fungus (Paxillus involutus). The rates of pyrene mineralization in the microcosms with humus implants (without pine) were initially insignificant but increased from Day 64 onward to 47 microg kg(-1) d(-1) and further to 144 microg kg(-1) d(-1) after Day 105. In the pine-planted humus microcosms the rate of mineralization also increased, reaching 28 microg kg(-1) d(-1) after Day 105. The 14CO2 emission was already considerable in nonplanted microcosms containing oily soil at Day 21 and the pyrene mineralization continued throughout the study. The pyrene was converted to CO2 at rates of 0.07 and 0.6 microg kg(-1) d(-1) in the oily-soil implanted microcosms with and without pine, respectively. When the probable assimilation of 14CO2 by the pine and ground vegetation was taken into account the most efficient microcosm mineralized 20% of the 91.2 mg kg(-1) pyrene in 180 d. The presence of pine and its mycorrhizal fungus had no statistically significant effect on mineralization yields. The rates of pyrene mineralization observed in this study for forest humus exceeded the total annual deposition rate of PAHs in southern Finland. This indicates that accumulation in forest soil is not to be expected.

  3. Synthesis, crystal structures and photoluminescence of anthracen- and pyrene-based coumarin derivatives.

    Science.gov (United States)

    Zhang, Hui; Tong, Hao; Zhao, Yuling; Yu, Tianzhi; Zhang, Peng; Li, Jianfeng; Fan, Duowang

    2015-11-01

    Two new anthracen- and pyrene-based coumarin derivatives, 3-(4-(anthracen-10-yl)phenyl)coumarin (4) and 3-(4-(pyrene-1-yl)phenyl)coumarin (5), were synthesized and characterized by FT-IR, (1)H NMR, element analysis and single crystal X-ray crystallography. The UV-vis absorption and photoluminescence spectra of these coumarin derivatives were investigated. The results show that compound 4 and 5 exhibit blue and blue-green emissions, respectively, under ultraviolet light excitation. Compared with the compound 4, the emission peak of compound 5 was bathochromically shifted by about 80 nm due to the more planar structure and larger π-conjugation.

  4. Preferential Formation of Benzo[a]pyrene Adducts at Lung Cancer Mutational Hotspots in P53

    Science.gov (United States)

    Denissenko, Mikhail F.; Pao, Annie; Tang, Moon-Shong; Pfeifer, Gerd P.

    1996-10-01

    Cigarette smoke carcinogens such as benzo[a]pyrene are implicated in the development of lung cancer. The distribution of benzo[a]pyrene diol epoxide (BPDE) adducts along exons of the P53 gene in BPDE-treated HeLa cells and bronchial epithelial cells was mapped at nucleotide resolution. Strong and selective adduct formation occurred at guanine positions in codons 157, 248, and 273. These same positions are the major mutational hotspots in human lung cancers. Thus, targeted adduct formation rather than phenotypic selection appears to shape the P53 mutational spectrum in lung cancer. These results provide a direct etiological link between a defined chemical carcinogen and human cancer.

  5. Effects of Sludge-amendment on Mineralization of Pyrene and Microorganisms in Sludge and Soil

    DEFF Research Database (Denmark)

    Klinge, C; Gejlsbjerg, B; Ekelund, Flemming

    2001-01-01

    . Sludge-amendment enhanced the mineralization of pyrene in the soil compared to soil without sludge, and the most extensive mineralization was observed when the sludge was kept in a lump. The number of protozoa, heterotrophic bacteria and pyrene-mineralizing bacteria was much higher in the sludge compared...... to the soil. The amendment of sludge did not affect the number of protozoa and bacteria in the surrounding soil, which indicated that organic contaminants in the sludge had a little effect on the number of protozoa and bacteria in the surrounding soil...

  6. Different Photophysical Properties of Aryl-bipyridine Linked Pyrene and Anthracene

    Institute of Scientific and Technical Information of China (English)

    熊飞; 王双青; 何黎明; 李沙瑜; 甘泉; 张国齐; 李嫣; 杨国强

    2005-01-01

    6-Phenyl-2,2'-bipyridine linked pyrene and anthracene were synthesized and their photophysical properties were measured in different solvents with different polarity. 4-Pyren-1""-yl-6-phenyl-2,2'-bipyridine (Ppbpy) showed significant solvent-dependent properities while 4-anthracen-yl-9""-yl-6-phenyl-2,2'-bipyridine (Apbpy) displayed solvent-independence, although they had similar molecular structure. Because of different twist angle between thyarene and aryl-bipyridine, Ppbpy displayed intermixing behaviors of local excited state (1La and 1Lb) and intramolecular charge transfer (ICT), but Apbpy only showed the properties of local excited state 1La.

  7. Bacterial degradation of recalcitrant PAHs: metabolic studies and application to pyrene degradation in a freshwater sediment

    Energy Technology Data Exchange (ETDEWEB)

    Jouanneau, Y.; Demaneche, S.; Meyer, Ch.; Willison, J.C. [CEA-Grenoble, UMR 5092 CNRS-CEA-UJF, 38 - Grenoble (France)

    2005-07-01

    Cost-effective bio-remediation strategies have been proposed to remove toxic chemicals, including polycyclic aromatic hydrocarbons (PAHs), from contaminated sites. However, the efficiency of these strategies is often limited, due to the resistance of certain chemicals to microbial degradation. Our studies deal with the biodegradation of four-ring PAHs using two recently isolated bacteria, Mycobacterium strain 6PY1, which can mineralize pyrene and phenanthrene, and Sphingomonas strain CHY-1, which mineralizes chrysene and various three-ring PAHs. The metabolic pathways for the biodegradation of PAHs have been investigated using GC-MS to identify and assay metabolites. Also, several enzymes involved in PAH catabolism have been identified by a combination of proteomic and genetic approaches. In Mycobacterium 6PY1, two ring-hydroxylating di-oxygenases which catalyze the initial attack of PAHs have been overproduced in E. coli, isolated and characterized. The selectivity of the two enzymes showed marked differences, since one di-oxygenase preferentially oxidized 2- or 3- ring PAHs whereas the other attacked pyrene and 3-ring PAHs exclusively. In Sphingomonas CHY-1, a single di-oxygenase, called PhnI, was found to convert seven PAHs, including chrysene, to the corresponding dihydro-diols. It is the first enzyme to be described which is able to attack the four-ring PAHs chrysene and benz[a]anthracene.. The fate of pyrene was examined in a sediment taken from a freshwater lake of the French Alps. Experiments were carried out in microcosms containing a layer of sediment which was spiked with {sup 14}C-pyrene. Pyrene mineralization was monitored over 61 days by measuring the {sup 14}CO{sub 2} evolved from the microcosms. Some microcosms were planted with young reeds (Phragmites australis), while other were inoculated with Mycobacterium 6PY1. P. australis reeds promoted a significant increase of pyrene degradation, which most likely resulted from a root-mediated increase of

  8. A comparative intracellular proteomic profiling of Pseudomonas aeruginosa strain ASP-53 grown on pyrene or glucose as sole source of carbon and identification of some key enzymes of pyrene biodegradation pathway.

    Science.gov (United States)

    Mukherjee, Ashis K; Bhagowati, Pabitra; Biswa, Bhim Bahadur; Chanda, Abhishek; Kalita, Bhargab

    2017-09-07

    Pseudomonas aeruginosa strain ASP-53, isolated from a petroleum oil-contaminated soil sample, was found to be an efficient degrader of pyrene. PCR amplification of selected hydrocarbon catabolic genes (alkB gene, which encodes for monooxygenase, and the C12O, C23O, and PAH-RHDα genes encoding for the dioxygenase enzyme) from the genomic DNA of P. aeruginosa strain ASP-53 suggested its hydrocarbon degradation potential. The GC-MS analysis demonstrated 30.1% pyrene degradation by P. aeruginosa strain ASP-53 after 144h of incubation at pH6.5, 37°C. Expressions of 115 and 196 intracellular proteins were unambiguously identified and quantitated by shotgun proteomics analysis when the isolate was grown in medium containing pyrene and glucose, respectively. The pyrene-induced uniquely expressed and up-regulated proteins in P. aeruginosa strain ASP-53 in addition to substrate (pyrene) metabolism are also likely to be associated with different cellular functions for example-related to protein folding (molecular chaperone), stress response, metabolism of carbohydrate, proteins and amino acids, and fatty acids; transport of metabolites, energy generation such as ATP synthesis, electron transport and nitrate assimilation, and other oxidation-reduction reactions. Proteomic analyses identified some important enzymes involved in pyrene degradation by P. aeruginosa ASP-53 which shows that this bacterium follows the salicylate pathway of pyrene degradation. This study is the first report on proteomic analysis of pyrene biodegradation pathway by Pseudomonas aeruginosa, isolated from a petroleum-oil contaminated soil sample. The pathway displays partial similarity with deduced pyrene degradation mechanisms of Mycobacterium vanbaalenii PYR-1. The GC-MS analysis as well as PCR amplification of hydrocarbon catabolic genes substantiated the potency of the bacterium under study to effectively degrade high molecular weight, toxic PAH such as pyrene for its filed scale bioremediation

  9. Degradation of pyrene, benz[a]anthracene, and benzo[a]pyrene by Mycobacterium sp. strain RJGII-135, isolated from a former coal gasification site.

    Science.gov (United States)

    Schneider, J; Grosser, R; Jayasimhulu, K; Xue, W; Warshawsky, D

    1996-01-01

    The degradation of three polycyclic aromatic hydrocarbons (PAH), pyrene (PYR), benz[a]anthracene (BAA), and benzo[a]pyrene (BaP), by Mycobacterium sp. strain RJGII-135 was studied. The bacterium was isolated from an abandoned coal gasification site soil by analog enrichment techniques and found to mineralize [14C]PYR. Further degradation studies with PYR showed three metabolites formed by Mycobacterium sp. strain RJGII-135, including 4,5-phenanthrene-dicarboxylic acid not previously isolated, 4-phenanthrene-carboxylic acid, and 4,5-pyrene-dihydrodiol. At least two dihydrodiols, 5,6-BAA-dihydrodiol and 10,11-BAA-dihydrodiol, were confirmed by high-resolution mass spectral and fluorescence analyses as products of the biodegradation of BAA by Mycobacterium sp. strain RJGII-135. Additionally, a cleavage product of BAA was also isolated. Mass spectra and fluorescence data support two different routes for the degradation of BaP by Mycobacterium sp. strain RJGII-135. The 7,8-BaP-dihydrodiol and three cleavage products of BaP, including 4,5-chrysene-dicarboxylic acid and a dihydro-pyrene-carboxylic acid metabolite, have been isolated and identified as degradation products formed by Mycobacterium sp. strain RJGII-135. These latter results represent the first example of the isolation of BaP ring fission products formed by a bacterial isolate. We propose that while this bacterium appears to attack only one site of the PYR molecule, it is capable of degrading different sites of the BAA and BaP molecules, and although the sites of attack may be different, the ability of this bacterium to degrade these PAH is well supported. The proposed pathways for biodegradation of these compounds by this Mycobacterium sp. strain RJGII-135 support the dioxygenase enzymatic processes reported previously for other bacteria. Microorganisms like Mycobacterium sp. strain RJGII-135 will be invaluable in attaining the goal of remediation of sites containing mixtures of these PAH.

  10. Dietary effects on the uptake of benzo[a]pyrene.

    Science.gov (United States)

    Stavric, B; Klassen, R

    1994-08-01

    It has been established that exposure to polycyclic aromatic hydrocarbons (PAHs), or more specifically benzo[a]pyrene (B[a]P), either by inhalation through cigarette smoking or by contact through occupational exposure of the lungs or skin, can result in cancerous lesions. It appears that the general population consumes more B[a]P from food than from smoking. Despite this, epidemiological studies have not implicated B[a]P from foods as a causative factor in some human cancers. This lack of an epidemiological correlation between cancer incidence and intake of dietary PAHs/B[a]P could be due to some 'protective' or 'detoxification' mechanism. Despite the abundance of literature regarding the food content of B[a]P, there are few data concerning its uptake from foods. In the present study we investigated the intestinal absorption of B[a]P from foods using bile duct cannulated rats and radioactive B[a]P. [14C]B[a]P was first added to solvents such as water, corn oil, liquid paraffin or 50% ethanol, which were the administered by gavage to rats fed diets with or without added carbon. Additionally, food polyphenols such as quercetin and chlorogenic acid were also tested for their effect on the absorption of B[a]P. The results indicated that the excretion of B[a]P in the bile was reduced by water, carbon, quercetin and chlorogenic acid but was potentiated by corn oil. To complement the in vivo studies, some in vitro tests to investigate the efficiency of B[a]P extraction from different foods using water or oil as solvents were also performed. These tests indicated that extraction of B[a]P from foods was affected by the solvent. It is postulated that reduced solubility, physical adsorption and the formation of chemical adducts between B[a]P and some food ingredients, play a sporadic, although still not well determined, role in reducing the absorption of B[a]P from the gut. The results of these studies suggest that B[a]P absorption from the intestinal tract is markedly

  11. Toxicity of benzo(a)pyrene and pyrene in the mosquito Aedes aegypti, in the dark and in the presence of ultraviolet light

    Energy Technology Data Exchange (ETDEWEB)

    Kagan, J.; Kagan, E.D.

    1986-03-01

    The phototoxicity of benzo(a)pyrene constitutes a much greater risk to immature forms of the mosquito Aedes aegypti than its mutagenicity of carcinogenicity. First instar larvae, fourth instar larvae, and pupae of the mosquito Aedes aegypti were treated with benzo(a)pyrene at concentrations up to 6.7 ppm, either in the dark or in the presence of long wavelength ultraviolet light (for only 30 min). The irradiations had a profound effect on the fate of first instar larvae. Their LC/sub 50/ value for 24 h survival was about 0.002 ppm. When the adult emergence was determined, the LC/sub 50/ value was about 0.0015 ppm. The development of fourth instar larvae was also modified by the photochemical treatments, with an LC/sub 50/ value for adult emergence of 0.12 ppm. The LC/sub 50/ values for the highly carcinogenic BAP are very similar to those determined for pyrene, its non-carcinogenic parent molecule. This provides one additional proof that the carcinogenicity and the phototoxicity of polycyclic aromatic hydrocarbons are not necessarily related.

  12. Hypoxia diminishes the detoxification of the environmental mutagen benzo[a]pyrene

    NARCIS (Netherlands)

    Schults, Marten A.; Sanen, Kathleen; Godschalk, Roger W.; Theys, Jan; van Schooten, Frederik J.; Chiu, Roland K.

    2014-01-01

    Hypoxia promotes genetic instability and is therefore an important factor in carcinogenesis. We have previously shown that activation of the hypoxia responsive transcription factor HIF alpha can enhance the mutagenic phenotype induced by the environmental mutagen benzo[a]pyrene (BaP). To further elu

  13. Effects of pyrene exposure and temperature on early development of two co-existing Arctic copepods

    DEFF Research Database (Denmark)

    Grenvald, Julie Cornelius; Nielsen, Torkel Gissel; Hjorth, Morten

    2013-01-01

    Oil exploration is expected to increase in the near future in Western Greenland. At present, effects of exposure to oil compounds on early life-stages of the ecologically important Calanus spp. are unknown. We investigated the effects of the oil compound pyrene, on egg hatching and naupliar devel...

  14. Degradation of pyrene by immobilized microorganisms in saline-alkaline soil.

    Science.gov (United States)

    Wang, Shanxian; Li, Xiaojun; Liu, Wan; Li, Peijun; Kong, Lingxue; Ren, Wenjie; Wu, Haiyan; Tu, Ying

    2012-01-01

    Biodegradation of polycyclic aromatic hydrocarbons (PAHs) is very difficult in saline-alkaline soil due to the inhibition of microbial growth under saline-alkaline stress. The microorganisms that can most effectively degrade PAHs were screened by introducing microorganisms immobilized on farm byproducts and assessing the validity of the immobilizing technique for PAHs degradation in pyrene-contaminated saline-alkaline soil. Among the microorganisms examined, it was found that Mycobacterium sp. B2 is the best, and can degrade 82.2% and 83.2% of pyrene for free and immobilized cells after 30 days of incubation. The immobilization technique could increase the degradation of pyrene significantly, especially for fungi. The degradation of pyrene by the immobilized microorganisms Mucor sp. F2, fungal consortium MF and co-cultures of MB+MF was increased by 161.7% (P soil, as the interspace of the carrier material structure was relatively large, providing enough space for cell growth. Co-cultures of different bacterial and fungal species showed different abilities to degrade PAHs. The present study suggests that Mycobacterium sp. B2 can be employed for in situ bioremediation of PAHs in saline-alkaline soil, and immobilization of fungi on farm byproducts and nutrients as carriers will enhance fungus PAH-degradation ability in saline-alkaline soil.

  15. Biotransformation of the polycyclic aromatic hydrocarbon pyrene in the marine polychaete Nereis virens

    DEFF Research Database (Denmark)

    Jørgensen, Anne; Glessing, Anders M B; Rasmussen, Lene Juel

    2005-01-01

    In vivo and in vitro biotransformation of the polycyclic aromatic hydrocarbon (PAH) pyrene was investigated in the marine polychaete Nereis virens. Assays were designed to characterize phase I and II enzymes isolated from gut tissue. High-pressure liquid chromatography measurement of 1-hydroxypyr...

  16. Applications of PDMS partitioning methods in the study of biodegradation of pyrene in the

    DEFF Research Database (Denmark)

    Tejeda-Agredano, MC; Gouliarmou, Varvara; Ortega-Calvo, JJ

    Although there are reports on the inhibition of anthropogenic organic chemicals biodegradation due to binding to dissolved humic substances (HS), there is an increasing body of evidence pointing to an enhancing effect in the case of hydrophobic chemicals, like pyrene. The addition of humic fracti...

  17. Molecular dynamics simulation on adsorption of pyrene-polyethylene onto ultrathin single-walled carbon nanotube

    Science.gov (United States)

    Cai, Lu; Lv, Wenzhen; Zhu, Hong; Xu, Qun

    2016-07-01

    The mechanism of the adsorption of pyrene-polyethylene (Py-PE) onto ultrathin single-walled carbon nanotube (SWNT) was studied by using all-atom molecular dynamics (MD) simulations. We found that solvent polarity and pyrene group are two critical factors in the Py-PE decoration on ultrathin SWNT. Combined MD simulations with free energy calculations, our results indicate that larger solvent polarity can decrease the contribution of conformation entropy, but contributes little to the interaction energy, moreover, larger SWNT diameter can decrease the contribution of conformation entropy but lead to the increasing of the interaction energy. In polar organic solvent (N, N-Dimethylacetamide), the pyrene group plays a key role in the adsorption of Py-PE onto ultrathin SWNT, not only facilitates the spontaneous adsorption of Py-PE onto ultrathin SWNT, but also helps to form compact structure between themselves in the final adsorption states. While in aqueous solution, pyrene group no longer works as an anchor, but still affects a lot to the final adsorption conformation. Our present work provides detailed theoretical clue to understand the noncovalent interaction between aromatic segment appended polymer and ultrathin SWNT, and helps to explore the potential application of ultrathin SWNT in the fields of hybrid material, biomedical and electronic materials.

  18. Metabolic activation and DNA binding of benzo(a)pyrene in cultured human bronchus

    DEFF Research Database (Denmark)

    1977-01-01

    Human bronchus is one target site for the carcinogenic action of tobacco smoke, which contains chemical carcinogens, including benzo(a)pyrene. Human bronchi were obtained from surgery or “immediate” autopsy and then cultured in a chemically defined medium. The cultured bronchi were exposed...

  19. STUDYING THE INFLUENCE OF THE PYRENE INTERCALATOR TINA ON THE STABILITY OF DNA i-MOTIFS

    DEFF Research Database (Denmark)

    El-Sayed, Ahmed A.; Pedersen, Erik Bjerregaard; Khaireldin, Nahid A.

    2012-01-01

    Certain cytosine-rich (C-rich) DNA sequences can fold into secondary structures as four-stranded i-motifs with hemiprotonated base pairs. Here we synthesized C-rich TINA-intercalating oligonucleotides by inserting a nonnucleotide pyrene moiety between two C-rich regions. The stability of their i...

  20. Transcriptomic changes in zebrafish embryos and larvae following benzo[a]pyrene exposure

    Science.gov (United States)

    Benzo[a]pyrene (BaP) is an environmentally relevant carcinogenic and endocrine disrupting compound that causes immediate, long-term, and multigenerational health deficits in mammals and fish. Previously, we found that BaP alters DNA methylation patterns in developing zebrafish, which may affect gene...

  1. Benzo[a]pyrene decreases global and gene specific DNA methylation during zebrafish development

    Science.gov (United States)

    DNA methylation is important for gene regulation and is vulnerable to early-life exposure to environmental contaminants. We found that direct waterborne benzo[a]pyrene (BaP) exposure at 24 'g/L from 2.5 to 96 hours post fertilization (hpf) to zebrafish embryos significantly decreased global cytosine...

  2. Peculiarities of metabolism of anthracene and pyrene by laccase-producing fungus Pycnoporus sanguineus H1.

    Science.gov (United States)

    Li, Xuanzhen; Wang, Yan; Wu, Shijin; Qiu, Lequan; Gu, Li; Li, Jingjing; Zhang, Bao; Zhong, Weihong

    2014-01-01

    The metabolic peculiarities of anthracene and pyrene by Pycnoporus sanguineus H1 were investigated. The fungus H1 could grow on potato dextrose agar plates with anthracene and anthraquinone as carbon sources. In liquid medium, the strain degraded 8.5% of anthracene as the sole carbon source, with no ligninolytic enzymes detected, indicating that intracellular catabolic enzymes might be responsible for the initial oxidation of anthracene. When bran was added to the medium, the degradation rate of anthracene and pyrene increased to 71.3% and 30.2%, respectively, and the laccase activities increased to a maximal value of 501.2 and 587.6 U/L, respectively. By gas chromatography-mass spectrometry analysis, anthraquinone was detected as the unique intermediate product of anthracene oxidation, with a yield molar ratio of 0.3. In vitro experiments showed that the extracellular culture fluid containing laccase transformed anthracene to anthraquinone with a yield molar ratio of 1.0, which was less than that of the in vivo experiment, indicating that anthraquinone could be further metabolized by the strain. Pyrene could not be oxidized by culture fluid. These results showed that both extracellular laccase and intracellular catabolic enzymes might play an important role in the initial oxidation of anthracene, whereas pyrene could be only oxidized by intracellular catabolic enzymes through cometabolism.

  3. Biodegradation of pyrene and phenanthrene by bacterial consortium and evaluation of role of surfactant.

    Science.gov (United States)

    Kumari, B; Rajput, S; Gaur, P; Singh, S N; Singh, D P

    2014-12-24

    High molecular weight poly aromatic hydrocarbons (HMW PAHs) are well known for their hydrophobicity and they get strongly adsorbed onto the soil particles. Generally, surfactants facilitate the biodegradation of PAH by enhancing their solubility and desorption of hydrophobic compounds from soil particles. To investigate the role of synthetic surfactant in biodegradation of PAHs, two bacterial strains BP10 and P2 were incubated in soil spiked with pyrene and phenantherene (100 μg g-1of soil each) in isolation and in combination with/without Tween 80. After 14 days of incubation, pyrene and phenantherene were degraded by a combination of BP10 and P2 to the extent of 98% and 99%, respectively. Addition of tween 80 reduced the degradation of pyrene and phenantherene by 35 and 10%, respectively. Biosurfactant produced by selected strains i.e. BP10 and P2 could enhance desorption of pyrene (100 μg g-1of soil) by about 27% and 12%, respectively. However, desorption activity was relatively higher (32 and 29%, respectively) in case of phenanthrene (100 μg g-1of soil) from the spiked soil. Present study showed that in spite of additional chemical surfactant, bioaugmentation of highly petroleum hydrocarbon degrading bacterial combination was very effective in boosting the bioremediation of PAHs- contaminated sites.

  4. Benzo(A)pyrene Decreases Brain and Ovarian Aromatase mRNA Expression

    Science.gov (United States)

    The higher molecular weight polycyclic aromatic hydrocarbons (PAHs) such as benzo(a)pyrene (BaP) are typically associated with genotoxicity, however newer evidence suggests that these compounds may also act as endocrine system disruptors. We hypothesized that a target for reproductive or development...

  5. Biotransformation of the polycyclic aromatic hydrocarbon pyrene by the marine polychaete Nereis virens

    DEFF Research Database (Denmark)

    Jørgensen, Anne; Giessing, Anders M. B.; Rasmussen, Lene Juel

    2005-01-01

    In vivo and in vitro biotransformation of the polycyclic aromatic hydrocarbon (PAH) pyrene was investigated in the marine polychaete Nereis virens. Assays were designed to characterize phase I and II enzymes isolated from gut tissue. High-pressure liquid chromatography measurement of 1-hydroxypyr...

  6. Patterns of 1-hydroxypyrene excretion in volunteers exposed to pyrene by the dermal route

    Energy Technology Data Exchange (ETDEWEB)

    Viau, C.; Vyskocil, A. [University of Montreal, Montreal, PQ (Canada)

    1995-02-24

    The urinary excretion profiles following exposure to pyrene were established in one psoriasic patient under treatment with a coal tar-based shampoo and in two other volunteers exposed to a single dose of 100{mu}1 creosote and, in a separate experiment, to five consecutive daily dermal applications of 500{mu}g pyrene on 200 cm{sup 2} of the inner face of the forearms. Timed micturitions were collected for up to 48 h following exposure. Both in the psoriasic patient and in the volunteers exposed to creosote, the excretion peaks between 10 and 15 h after application and first-order apparent half lives of 11.5-15 h can be calculated for the elimination phase. Compatible with these observations, repeated exposure to pyrene in the volunteers causes an increase in peak and trough urinary 1-hydroxypyrene (1-OHP) values for the first few days following the first exposure. These results suggest that the difference between beginning-of-shift/beginning of work week and beginning-of-shift/end of work week 1-OHP excretion should reflect the average exposure of the week in workers having a constant exposure to pyrene. The difference between the beginning and end-of-shift excretion values of a given day should reflect the exposure of that day but the maximum excretion would be attained a few hours after termination of exposure.

  7. A ferrocene-pyrene based 'turn-on' chemodosimeter for Cr(3+)- application in bioimaging.

    Science.gov (United States)

    Kaur, Mandeep; Kaur, Paramjit; Dhuna, Vikram; Singh, Sukhdev; Singh, Kamaljit

    2014-04-21

    Structurally simple, ferrocene-pyrene imine dyad 1 has been developed as a 'turn-on' chemodosimeter for Cr(3+). The sensing event is based upon the hydrolysis of the imine functionality. Further, 1, which is also non-cytotoxic (100% cell viability), detects intracellular Cr(3+) in the human breast cancer (MCF-7) cells.

  8. Binding of pyrene to dissolved organic matters:fractionation and characterization

    Institute of Scientific and Technical Information of China (English)

    DAI Jing-yu; ZHOU Jiang-min; QIN Shu-ping

    2004-01-01

    Based on a modified Leenheer DOM fractionation scheme, fractionation of DOM from the paddy soil was conducted by using XAD-8 resin into hydrophobic bases(HOB), hydrophobic acids(HOA), acid-insoluble matter(AIM), hydrophobic neutrals(HON) and hydrophilic matter(HIM). In total carbon content of DOM, 35.32% were the HIM and only 0.73% the HOB. However, HOA and AIM altogether occupied 53.45%, while the HON fraction represented 10%. The sorption experiments were conducted to determine the sorption capcity of pyrene on unfractionated DOM and its fractions. Elemental analysis, 1H-NMR and FTIR spectra were carried out on unfractionated DOM and its fractions to examine the relationship between the structure of DOM and partition coefficients(Koc). The results showed that HON had a greater affinity for binding pyrene than other fractions. While HON was characterized by large long-chain alkylate (aliphatic structure). AIM exhibited relative higher Koc values than HOA and HIM, due to much aromatic structure in AIM, while the high content of carboxylic groups of HOA and HIM depressed their binding capacity. This study demonstrates HON is a key subcomponents of DOM in binding of pyrene, in other words, aliphalic structure in DOM play a important role in binding of pyrene.

  9. Photoinduced electron and energy transfer processes in a bichromophoric pyrene-perylene bisimide system

    NARCIS (Netherlands)

    Kaletas, B.K.; Dobrava, R.; Sautter, A.; Wurthner, F.; Zimine, M.; De Cola, L.; Williams, R.M.

    2004-01-01

    The synthesis and photophysical properties of a system consisting of a bay-functionalized perylene bisimide, containing four appended pyrene and two coordinating pyridine units, and its reference system are described. A complete study of their photophysical properties was obtained using UV-vis absor

  10. Photoinduced Electron and Energy Transfer Processes in a Bichromophoric Pyrene-Perylene Bisimide System

    NARCIS (Netherlands)

    Kaletas, B.K.; Dobrawa, R.; Sautter, A.; Wuerthner, F.; Zimine, M.Y.; De Cola, L.; Williams, R.M.

    2004-01-01

    The synthesis and photophysical properties of a system consisting of a bay-functionalized perylene bisimide, containing four appended pyrene and two coordinating pyridine units, and its reference system are described. A complete study of their photophysical properties was obtained using UV-vis absor

  11. Synthesis, structures, redox and photophysical properties of benzodifuran-functionalised pyrene and anthracene fluorophores.

    Science.gov (United States)

    Keller, Stephan; Yi, Chenyi; Li, Chen; Liu, Shi-Xia; Blum, Carmen; Frei, Gabriela; Sereda, Olha; Neels, Antonia; Wandlowski, Thomas; Decurtins, Silvio

    2011-09-21

    Benzodifuran-functionalised pyrene and anthracene fluorophores 1 and 2 were obtained in reasonable yields. Their single crystal structures, electrochemical, optical absorption, and fluorescence characteristics have been described. They show strong luminescence with high quantum yields of 0.53 for 1 and 0.48 for 2.

  12. Hydroxyl radical generation and oxidative stress in Carassius auratus liver, exposed to pyrene.

    Science.gov (United States)

    Sun, Yuanyuan; Yin, Ying; Zhang, Jingfei; Yu, Hongxia; Wang, Xiaorong; Wu, Jichun; Xue, Yuqun

    2008-10-01

    This paper studied the hydroxy radical generation and oxidative stress in the liver of goldfish Carassius auratus under the effect of pyrene. Fish were exposed to different concentrations (0.001, 0.005, 0.01, 0.05 and 0.1 mg/L) of pyrene for 10 days, with one group assigned as control. Based on the hyperfine splitting constants and shape of the electron paramagnetic resonance (EPR) spectrum, the free radical which was generated in fish liver was identified as hydroxyl radical ((*)OH). The (*)OH signal intensity showed a significant increase compared with the control. The changes of the activities of catalase (CAT), superoxide dismutase (SOD), and glutathione-S-transferase (GST) were detected. The reduced glutathione (GSH) level decreased significantly while oxidized glutathione (GSSG) level was increased at higher concentration (0.005-0.1 mg/L), resulting in a decreased GSH/GSSG ratio, and the malondialdehyde (MDA) content increased significantly at 0.005-0.1 mg/L pyrene. The results clearly showed that C. auratus was subjected to oxidative stress and damage when exposed to pyrene.

  13. Uptake of pyrene in a breast-fed child of a mother treated with coal tar.

    NARCIS (Netherlands)

    Scheepers, P.T.J.; Houtum, J.L.M. van; Anzion, R.B.M.; Harder, R.; Bos, R.P.; Valk, P.G.M. van der

    2009-01-01

    A woman was treated for atopic dermatitis with coal tar containing ointments. Coal tar containing ointments contain genotoxic polycyclic aromatic hydrocarbons. Over a period of 50 days the accumulated dose of different coal tar containing ointments treatments corresponded to 993 mg of pyrene and 464

  14. Sorption of Pyrene by Clay Minerals Coated with Dissolved Organic Matter (DOM from Landfill Leachate

    Directory of Open Access Journals (Sweden)

    Pingxiao Wu

    2015-01-01

    Full Text Available Interactions of dissolved organic matter (DOM from landfill leachate with clays could affect significantly the fate of hydrophobic organic compounds (HOCs in soils. The complexes of montmorillonite (MT and kaolinite (KL with DOM extracted from landfill leachate were prepared under controlled conditions, termed CMT and CKL, respectively. The bare clays and their complexes were characterized by powder X-ray diffraction (XRD, Fourier transform infrared (FTIR, thermogravimetry (TG, differential scanning calorimetry (DSC, and scanning electron microscopy (SEM. Batch experiments were designed to investigate the sorption behavior of pyrene onto the clays in the presence of DOM. The maximum sorption capacities of pyrene on MT, CMT, KL, and CKL were 22.18, 38.96, 42.00, and 44.99 μg·g−1, respectively, at the initial concentration of 1000 ± 150 μg·L−1. The sorption isotherms of pyrene by the bare clays followed the Henry model well, whereas the Freundlich sorption isotherm provided a better fit to the equilibrium data of the sorption by the complexes. The role of montmorillonite and kaolinite complexes with DOM in the retention of pyrene in soils was different. This may be due to the different crystal structures between montmorillonite and kaolinite.

  15. Degradation of Polycyclic Aromatic Hydrocarbon Pyrene by Biosurfactant-Producing Bacteria Gordonia cholesterolivorans AMP 10

    Directory of Open Access Journals (Sweden)

    Tri Handayani Kurniati

    2016-12-01

    Full Text Available Pyrene degradation and biosurfactant activity by a new strain identified as Gordonia cholesterolivorans AMP 10 were studied. The strain grew well and produced effective biosurfactants in the presence of glucose, sucrose, and crude oil. The biosurfactants production was detected by the decreased surface tension of the medium and emulsification activity.  Analysis of microbial growth parameters showed that AMP10 grew best at 50 µg mL-1 pyrene concentration, leading to 96 % degradation of pyrene within 7 days. The result of nested PCR analysis revealed that this isolate possessed the nahAc gene which encodes dioxygenase enzyme for initial degradation of Polycyclic Aromatic Hydrocarbon (PAH. Observation of both tensio-active and emulsifying activities indicated that biosurfactants which produced by AMP 10 when grown on glucose could lower the surface tension of medium from 71.3 mN/m to 24.7 mN/m and formed a stable emulsion in used lubricant oil with an emulsification index (E24 of 74%. According to the results, it is suggested that the bacterial isolates G. cholesterolivorans AMP10 are suitable candidates for bioremediation of PAH-contaminated environments.How to CiteKurniati, T. H.,  Rusmana, I. Suryani, A. & Mubarik, N. R. (2016. Degradation of Polycyclic Aromatic Hydrocarbon Pyrene by Biosurfactant-Producing Bacteria Gordonia cholesterolivorans AMP 10. Biosaintifika: Journal of Biology & Biology Education, 8(3, 336-343. 

  16. Joint toxicity of linear alkylbenzene sulfonates and pyrene on Folsomia fimetaria.

    Science.gov (United States)

    Jensen, John; Sverdrup, Line E

    2002-05-01

    Surfactants may enhance the biodegradation of hydrophobic substances in soils. This has partly been attributed to an increase in the bioavailability, brought about by the presence of surfactants. The aim of this study was to examine the ecotoxicological effects of the detergent linear alkylbenzene sulfonate (LAS) and the polycyclic aromatic hydrocarbon pyrene, alone and in combination, using the survival and reproduction of the collembolan Folsomia fimetaria as endpoints. The EC(50) and EC(10) were 803 and 161 mg kg(-1) for LAS, and 23 and 15 mg kg(-1) for pyrene. If LAS was able to increase the bioavailability of pyrene to springtails, it was expected that the combined effect of the two substances would exceed the effect found for each of the compounds tested separately. However, the results showed no effect of LAS on the toxicity of pyrene in the concentration range tested (1-750 mg LAS kg(-1) dry weight). Both the toxic unit concept and the isobologram method indicated that an additive approach would be the most useful when assessing the risk of these two compounds.

  17. Genotoxicity testing using the Mutatox assay: evaluation of benzo[a]pyrene as a positive control

    NARCIS (Netherlands)

    Klamer, H.J.C.; Villerius, L.A.; Roelsma, J.; Maagd, de P.G.J.; Opperhuizen, A.

    1997-01-01

    In a study on bioassay-directed chemical factionation of sediment extracts, problems were encountered using benzo(a)pyrene (BaP) as a positive control in the Mutatox™ bacterial genotoxicity assay. Genotoxic responses of tests with this compound, prescribed by the Mutatox supplier, could only be meas

  18. Effects of sediment organic matter quality on bioaccumulation, degradation, and distribution of pyrene in two macrofaunal species and their surrounding sediment

    DEFF Research Database (Denmark)

    Granberg, Maria E.; Selck, Henriette

    2007-01-01

    organic matter (SOM) quality affects organism activity and feeding behaviour, and is therefore also likely to affect contaminant fate in benthic systems. We investigated the impact of SOM quality (enrichment with either labile Tetraselmis sp. or refractory lignin) on the accumulation and metabolism...... of sediment-associated pyrene in Nereis diversicolor (Annelida) and Amphiura filiformis (Echinodermata), as well as the combined effect of SOM quality and infaunal bioturbation on pyrene distribution and metabolism in the sediment. After 45 d of exposure, SOM quality almost doubled pyrene bioaccumulation...... in both species, while pyrene metabolism remained unaffected. Metabolites comprised 80% of the total tissue pyrene in N. diversicolor and 40% in A. filiformis. A. filiformis arms contained one fifth of the disk pyrene concentration. Approximately 20% of the pyrene found in A. filiformis arms was found...

  19. The effects of simultaneous application of plant growth regulators and bioaugmentation on improvement of phytoremediation of pyrene contaminated soils.

    Science.gov (United States)

    Rostami, Saeid; Azhdarpoor, Abooalfazl; Rostami, Majid; Samaei, Mohammad Reza

    2016-10-01

    Polycyclic aromatic hydrocarbons (PAHs) refer to a wide group of soil contaminants whose presence in the environment is a cause of concern. The present study aimed to evaluate the effects of Indole Acetic Acid (IAA) and Pseudomonas aeruginosa on the phytoremediation activities of sorghum bicolor and increase in pyrene removal efficiency in the soil. The initial concentration of pyrene was 150 and 300 mg kg(-1) in this experiment. The treatments included unplanted soil (T0), planted soil with sorghum (T1), planted soil with application of IAA (T2), planted soil with application of Pseudomonas sp. (T3), and planted soil with simultaneous application of IAA and Pseudomonas sp. (T4). The pyrene removal rate in the soil was measured every 30 days. Moreover, plant biomass and soil bacteria were measured after 90 days. The results showed that pyrene removal rate significantly increased in the planted treatments compared to the unplanted ones. After 90 days, at the initial concentration of 150-300 mg kg(-1), pyrene removal efficiency was 52-92% in T1-T4 and 35-47% in the unplanted treatment (T0). Application of IAA and Pseudomonas sp. significantly increased plant biomass, soil bacteria, and pyrene removal rate in T2, T3, and T4 compared to T1. Therefore, application of IAA in the planted treatments with sorghum could have a significant effect on increasing the removal efficiency of pyrene.

  20. Bacterial communities predominant in the degradation of 13C(4)-4,5,9,10-pyrene during composting.

    Science.gov (United States)

    Peng, Jingjing; Zhang, Yuan; Su, Jianqiang; Qiu, Qiongfen; Jia, Zhongjun; Zhu, Yong-Guan

    2013-09-01

    An in-vessel composting bioremediation of (13)C4-4,5,9,10-pyrene and unlabeled pyrene spiked soil amended with fresh wastes was investigated by DNA-based stable isotope probing (SIP) of active bacteria involved. Highest dissipation of (13)C4-pyrene was detected at 55 °C after 42 days composting. The active bacterial communities in the composting changed over time, showing a distinct difference among different stages. α-, β-, γ-Proteobacteria, and Actinobacteria were detected mainly involving in pyrene degradation at 38 °C over 14 days composting. Streptomyces appeared to dominate the pyrene degradation at 55 °C. β- and γ-Proteobacteria and Actinobacteria were the dominant pyrene degraders at 70 °C after 42 days composting and at 38 °C after 60 days composting. The results of this study suggest the pyrene degradation was performed by phylogenetically distinct bacterial guilds from the phyla Actinobacteria and Proteobacteria during in-vessel composition processes.

  1. Thermodynamic and structural study of pyrene-1-carboxaldehyde/DNA interactions by molecular spectroscopy: Probing intercalation and binding properties

    Energy Technology Data Exchange (ETDEWEB)

    Grueso, E. [Department of Physical Chemistry, University of Seville, C/Profesor Garcia Gonzalez s/n, 41012 Seville (Spain); Prado-Gotor, R., E-mail: pradogotor@us.es [Department of Physical Chemistry, University of Seville, C/Profesor Garcia Gonzalez s/n, 41012 Seville (Spain)

    2010-08-03

    Graphical abstract: The exocyclic carbonyl compound pyren-1-carboxyaldehyde, (1-PyCHO), binds to the ctDNA in an intercalative mode. Two possible angular orientations for intercalation into base-pairs are possible. Induced circular dichroism measurements indicate that the intercalation orientation of 1-PyCHO into DNA could be heterogeneous, that is, multiple binding orientations of the pyren-1-carboxyaldehyde must be involved. - Abstract: The binding of pyrene-1-carboxaldehyde (1-PyCHO) with ctDNA was investigated through absorption, intrinsic and induced circular dichroism, viscosity measurements and steady-state fluorescence. The binding and the number of monomer units of the polymer involved in the binding of one dye molecule (site size) have been quantified. The results indicated that the 1-PyCHO molecule binds to the ctDNA in an intercalative mode. The spectroscopic evidence of this intercalation process is also corroborated by the effect of urea, iodide-induced fluorescence quenching of pyrene-1-carboxaldehyde and competitive binding using a fluorescent intercalator, SYBR Green I (SG). The induced circular dichroism (ICD) spectra of pyrene-1-carboxaldehyde complexed with ctDNA show that pyrene-1-carboxaldehyde intercalates into ctDNA and that the intercalation orientation of pyrene to the DNA base-pairs long axis is heterogeneous. On the other hand, the intrinsic circular dichroism (CD) spectra show a stabilization of the right-handed B form of ctDNA, due to the intercalation process.

  2. Preparation and Characterization of Palmitoyl Grafted Cellulose Nano Absorbent for the Efficient Adsorption of Pyrene from Aqueous Solution.

    Science.gov (United States)

    Jadhav, Arvind H; Mai, Xuan Thang; Appiah-Ntiamoah, Richard; Lee, Hanyeong; Momade, Francis W Y; Seo, Jeong Gil; Kim, Hern

    2015-10-01

    Palmitoyl grafted modified cellulose were prepared by simple chemical grafting method and applied as nano adsorbent for removal of pyrene from aqueous solution. The chemical properties and morphology of prepared nano-adsorbent were characterized by FT-IR, XRD, SEM, EDX, TGA, and contact angle. Results showed that palmitoyl successfully grafted on the surface of cellulose and possess effective organic functional groups for the adsorption of pyrene from aqueous solution. The adsorption performance of modified cellulose was significantly improved toward pyrene in aqueous solution. It is worthy to note that 0.25 g of palmitoyl grafted cellulose (PMC) removed 92% pyrene compared to unmodified cellulose which adsorbed 36% pyrene from 1.65 ppm aqueous solution of pyrene in very short contact time at room temperature. Results showed that, presence of various organic functional groups from palmitoyl chains grafted on cellulose backbone affected to pyrene removal. After completion of adsorption phenomenon nano-adsorbent can be removed by simply filtration process and reused several times. The adsorption capacity was studied under different experimental conditions and their effects on adsorption such as temperature, pH, and contact time were also studied. The kinetics and isotherms of material were also determined.

  3. Isolation and Identification of Pyrene-degrading Bacteria from Soils around Landfills in Shiraz and Their Growth Kinetic Assay

    Directory of Open Access Journals (Sweden)

    Farshid Kafilzadeh

    2011-12-01

    Full Text Available Background & Objectives: Pyrene is a kind of carcinogen hydrocarbon in environment and one of the top 129 pollutants as ranked by the U.S.Environmental Pretection Agency (USEPA. Today's commodious method that is considered by many researchers is the use of microorganisms to degrade these compounds from the environment. The goal of this research is separation and identification of the indigenous bacterias which are effective in decomposition of Pyrene hydrocarbon from soils around Shiraz Landfills. Isolated bacteria growth in the presence of different concentrations of the aforesaid organic pollutant was evaluated. Materials & Methods: Taking samples from Landfills were done after transportation them to the laboratory. The numbers of the bacterias were counted in a medium including Pyrene 0.6 g/l and in another medium without Pyrene. The isolated bacterias were separated by the enriched medium of hydrocarbon Pyrene and were recognized accordance with standards methods (specialty of colony, microscopic properties, fermentation of sugars and biochemical test.The kinetic growth of the separated bacterias was evaluated every 12 hours during 7 successive days. Results: It was reported that the numbers of the bacterias in the medium without Pyrene is more than those with Pyrene (cfu/g. The separated bacterias were included Bacillus spp., Pseudomonas spp., Micrococcus spp., Mycobacterium spp. These four isolated bacterias showed the best growth with Pyrene 0.6 g/l during third and fourth days. Conclusion: The separating bacterias, effecting in decomposition of PAH, make this possibility that the modern methods with more efficiency to be created for removing the carcinogen organic polluters from the environment. Moreover, the separated bacterias (relating to this research can be applied to develop the microbial population in the areas that polluted with Pyrene.

  4. Study of Necrosis in the Liver of Formaldehyde and Benzo(αPyrene Exposured-Mice

    Directory of Open Access Journals (Sweden)

    Ahmad Soni

    2013-04-01

    Full Text Available Formaldehyde and benzo(αpyrene are compounds that harmful for health. Misapplication of this compound has an impact in the form of organ damage in the body. This study aims to determine the impact of the treatment of the combined exposure of formaldehyde and benzo(αpyrene to cell necrosis in the liver of mice (Mus musculus. Treatment of formaldehyde dose of 25 mg/kg BW to mice was given orally every day for 60 days. Treatment of benzo(αpyrene via intraperitoneal injection at a dose of 250 mg/kg BW were given after 30 days of incubation with four times injection with one day interval. Liver organ histological preparations were made through the HE staining. Observations were made by using a microscope for liver organ preparations. The data obtained that is the percentage of cells necrosis and necrotic foci. This research used Completely Randomized Design (CRD with 95% confidence interval. Liver organ preparations observations indicate that the percentage of necrosis in the untreated control, benzo(αpyrene 250 mg/kg BW, formaldehyde 25 mg/kg BW, combination of formaldehyde 25 mg/kg BW with BaP in a row that is equal to 14.43% ± 0.91; 26.05% ± 3.75; 49.38% ± 2.66; 51.86 ± 1.73. The mean of necrotic foci in liver organ formed in the untreatment control, benzo(αpyrene 250 mg/kg BW, Formaldehyde 25 mg/kg BW, and the combination of formaldehyde 25 mg/kg BW with BaP in a row, equal to 1.3 ± 0,07; 1.63 ± 0.61; 2 ± 0.51, and 3.4 ± 0.76. This suggests that the combined treatment had the highest level of toxicity compared with other treatments.

  5. Microbial communities in pyrene amended soil-compost mixture and fertilized soil.

    Science.gov (United States)

    Adam, Iris K U; Duarte, Márcia; Pathmanathan, Jananan; Miltner, Anja; Brüls, Thomas; Kästner, Matthias

    2017-12-01

    Polycyclic aromatic hydrocarbons are distributed ubiquitously in the environment and form metabolites toxic to most organisms. Organic amendment of PAH contaminated soil with compost and farmyard manure has proven to be efficient for PAH bioremediation mediated by native microorganisms, even though information on the identity of PAH degraders in organic-amended soil is still scarce. Here we provide molecular insight into the bacterial communities in soil amended with compost or farmyard manure for which the degradation mass balances of (13)C-labeled pyrene have been recently published and assess the relevant bacterial genera capable of degrading pyrene as a model PAH. We performed statistical analyses of bacterial genera abundance data based on total DNA and RNA (for comparison) extracted from the soil samples. The results revealed complex pyrene degrading communities with low abundance of individual degraders instead of a limited number of abundant key players. The bacterial degrader communities of the soil-compost mixture and soil fertilized with farmyard manure differed considerably in composition albeit showing similar degradation kinetics. Additional analyses were carried out on enrichment cultures and enabled the reconstruction of several nearly complete genomes, thus allowing to link microcosm and enrichment experiments. However, pyrene mineralizing bacteria enriched from the compost or unfertilized soil-compost samples did not dominate pyrene degradation in the soils. Based on the present findings, evaluations of PAH degrading microorganisms in complex soil mixtures with high organic matter content should not target abundant key degrading species, since the specific degraders may be highly diverse, of low abundance, and masked by high bacterial background.

  6. Degradation of phenanthrene and pyrene using genetically engineered dioxygenase producing Pseudomonas putida in soil

    Directory of Open Access Journals (Sweden)

    Mardani Gashtasb

    2016-01-01

    Full Text Available Bioremediation use to promote degradation and/or removal of contaminants into nonhazardous or less-hazardous substances from the environment using microbial metabolic ability. Pseudomonas spp. is one of saprotrophic soil bacterium and can be used for biodegradation of polycyclic aromatic hydrocarbons (PAHs but this activity in most species is weak. Phenanthrene and pyrene could associate with a risk of human cancer development in exposed individuals. The aim of the present study was application of genetically engineered P. putida that produce dioxygenase for degradation of phenanthrene and pyrene in spiked soil using high-performance liquid chromatography (HPLC method. The nahH gene that encoded catechol 2,3-dioxygenase (C23O was cloned into pUC18 and pUC18-nahH recombinant vector was generated and transformed into wild P. putida, successfully. The genetically modified and wild types of P. putida were inoculated in soil and pilot plan was prepared. Finally, degradation of phenanthrene and pyrene by this bacterium in spiked soil were evaluated using HPLC measurement technique. The results were showed elimination of these PAH compounds in spiked soil by engineered P. putida comparing to dishes containing natural soil with normal microbial flora and inoculated autoclaved soil by wild type of P. putida were statistically significant (p0.05 but it was few impact on this process (more than 2%. Additional and verification tests including catalase, oxidase and PCR on isolated bacteria from spiked soil were indicated that engineered P. putida was alive and functional as well as it can affect on phenanthrene and pyrene degradation via nahH gene producing. These findings indicated that genetically engineered P. putida generated in this work via producing C23O enzyme can useful and practical for biodegradation of phenanthrene and pyrene as well as petroleum compounds in polluted environments.

  7. Degradation of pyrene by immobilized microorganisms in saline-alkaline soil

    Institute of Scientific and Technical Information of China (English)

    Shanxian Wang; Xiaojun Li; Wan Liu; Peijun Li; Lingxue Kong; Wenjie Ren; Haiyan Wu; Ying TU

    2012-01-01

    Biodegradation of polycyclic aromatic hydrocarbons (PAHs) is very difficult in saline-alkaline soil due to the inhibition of microbial growth under saline-alkaline stress.The microorganisms that can most effectively degrade PAHs were screened by introducing microorganisms immobilized on farm byproducts and assessing the validity of the immobilizing technique for PAHs degradation in pyrene-contaminated saline-alkaline soil.Among the microorganisms examined,it was found that Mycobacterium sp.B2 is the best,and can degrade 82.2% and 83.2% of pyrene for free and immobilized cells after 30 days of incubation.The immobilization technique could increase the degradation of pyrene significantly,especially for fungi.The degradation of pyrene by the immobilized microorganisms Mucor sp.F2,fungal consortium MF and co-cultures of MB+MF was increased by 161.7% (P < 0.05),60.1% (P <0.05) and 59.6% (P < 0.05) after 30 days,respectively,when compared with free F2,MF and MB+MF.Scanning electron micrographs of the immobilized microstructure proved the positive effects of the immobilized microbial technique on pyrene remediation in salinealkaline soil,as the interspace of the carrier material structure was relatively large,providing enough space for cell growth.Co-cultures of different bacterial and fungal species showed different abilities to degrade PAHs.The present study suggests that Mycobacterium sp.B2 can be employed for in situ bioremediation of PAHs in saline-alkaline soil,and immobilization of fungi on farm byproducts and nutrients as carriers will enhance fungus PAH-degradation ability in saline-alkaline soil.

  8. Effects of mineral surfaces on pyrene partitioning to well-characterized humic substances.

    Science.gov (United States)

    Hur, Jin; Schlautman, Mark A

    2004-01-01

    Mineral surfaces can alter the ability of humic substances (HS) to bind hydrophobic organic contaminants. In this study, complete adsorption (i.e., to avoid HS adsorptive fractionation effects) of a small subset of well-characterized terrestrial and aquatic HS on kaolinite and hematite significantly changed their subsequent organic carbon-normalized partition coefficients K(ads)(oc) for pyrene relative to their original respective dissolved organic carbon-normalized partition coefficients K(dis)(oc). Parallel experiments with ultrafiltration (UF) fractions obtained from purified Aldrich humic acid (PAHA) (Aldrich Chemical, Milwaukee, WI) gave similar results. The heterogeneity among the PAHA UF fractions was examined via their mineral surface adsorption characteristics and their subsequent ability to bind pyrene. As expected, variations in maximum adsorption densities (q(max)), Langmuir adsorption constants (K(q)), and pyrene K(ads)(oc) values were observed among the PAHA UF fractions. However, general trends of q(max), K(q), and pyrene log K(ads)(oc) values for the PAHA UF fractions versus the logarithm of their weight-average molecular weights (MW(w)) did not typically match the corresponding trends obtained with the four aquatic and terrestrial HS. In general, an ideal mixture competitive adsorption model gave reasonable predictions for PAHA sorption to kaolinite and hematite based on their corresponding UF isotherm parameters. Ideal mixture predictions of pyrene partitioning to adsorbed PAHA from the corresponding UF fraction results were better for kaolinite versus hematite, indicating that the underlying mineral surface can alter the effects of HS heterogeneity on hydrophobic organic contaminant sorption.

  9. Pyrene Removal from Contaminated Soils by Modified Fenton Oxidation Using Iron Nano Particles

    Directory of Open Access Journals (Sweden)

    Sahand Jorfi

    2013-07-01

    Full Text Available Background:The problems related to conventional Fenton oxidation, including low pH required and production of considerable amounts of sludge have led researchers to investigate chelating agents which might improve the operating range of pH and the use of nano iron particle to reduce the excess sludge. The pyrene removal from contaminated soils by modified Fenton oxidation at neutral pH was defined as the main objective of the current study.Methods:Varying concentrations of H2O2 (0-500 mM and iron nano oxide (0-60 mM, reaction times of 0.5-24 hours and variety of chelating agents including sodium pyrophosphate, sodium citrate, ethylene diamine tetraacetic, fulvic and humic acid were all investigated at pyrene concentration levels of 100 – 500 mg/kg.Results:By applying the following conditions (H2O2 concentration of 300 mM, iron nano oxide of 30 mM, sodium pyrophosphate as chelating agent, pH 3 and reaction time of 6 hours the pyrene removal efficiency at an initial concentration of 100 mg/kg was found to be 99%. As a result, the pyrene concentration was reduced from 100 to 93 mg/kg once the above optimum conditions are met.Conclusions:In this research, the modified Fenton oxidation using iron nano oxide at optimum conditions is introduced as an efficient alternative method in lab scale for chemical remediation or pre-treatment of soils contaminated by pyrene at neutral pH.

  10. Unlocked nucleic acids with a pyrene-modified uracil: Synthesis, hybridization studies, fluorescent properties and i-motif stability

    DEFF Research Database (Denmark)

    Perlíková, P.; Karlsen, K.K.; Pedersen, E.B.

    2014-01-01

    .2, both under molecular crowding and noncrowding conditions. The presence of the pyrene-modified UNA monomers in DNA strands led to decreases in the thermal stabilities of DNA/DNA and DNA/RNA duplexes, but these duplexes' thermal stabilities were better than those of duplexes containing unmodified UNA...... intensities upon hybridization to DNA or RNA. Efficient quenching of fluorescence of pyrene-modified UNA monomers was observed after formation of i-motif structures at pH 5.2. The stabilizing/destabilizing effect of pyrene-modified nucleic acids might be useful for designing antisense oligonucleotides...... and hybridization probes....

  11. The supramolecular design of low-dimensional carbon nano-hybrids encoding a polyoxometalate-bis-pyrene tweezer.

    Science.gov (United States)

    Modugno, Gloria; Syrgiannis, Zois; Bonasera, Aurelio; Carraro, Mauro; Giancane, Gabriele; Valli, Ludovico; Bonchio, Marcella; Prato, Maurizio

    2014-05-18

    A novel bis-pyrene tweezer anchored on a rigid polyoxometalate scaffold fosters a unique interplay of hydrophobic and electrostatic supramolecular interactions, to shape carbon nanostructures (CNSs)-based extended architectures.

  12. Effects of Tween 80 on the removal, sorption and biodegradation of pyrene by Klebsiella oxytoca PYR-1.

    Science.gov (United States)

    Zhang, Dong; Zhu, Lizhong

    2012-05-01

    The sorption and biodegradation of pyrene by Klebsiella oxytoca PYR-1 (PYR-1) in the presence of nonionic surfactant Tween 80 were investigated toward a better understanding that how surfactants can affect biodegradation of hydrophobic organic compounds. The results indicated that Tween 80 can promote the removal, sorption and biodegradation of pyrene depending on the surfactant concentration, of which the most significant promotion of biodegradation was achieved at critical micelle concentration of Tween 80 with an improvement of 22.4%. A highly positive correlation (PTween 80. Biosorption experiments showed the same trends as biodegradation and further illustrated the improved biodegradation of pyrene was mainly due to surfactant-facilitated sorption. The regularly changes of cell surface hydrophobicity suggested formation of more hydrophobic surface caused by surfactant sorption lead to stimulation of pyrene sorption.

  13. Topological analysis of the electron density and of the electron localization function of pyrene and its radicals

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez-Trujillo, Jesus [Programa de Ingenieria Molecular, Instituto Mexicano del Petroleo, Eje Central Lazaro Cardenas 152, Colonia San Bartolo Atepehuacan, Mexico, D.F. 07730 (Mexico)]. E-mail: jesus.hernandez@correo.unam.mx; Garcia-Cruz, Isidoro [Programa de Ingenieria Molecular, Instituto Mexicano del Petroleo, Eje Central Lazaro Cardenas 152, Colonia San Bartolo Atepehuacan, Mexico, D.F. 07730 (Mexico); Martinez-Magadan, Jose Manuel [Programa de Ingenieria Molecular, Instituto Mexicano del Petroleo, Eje Central Lazaro Cardenas 152, Colonia San Bartolo Atepehuacan, Mexico, D.F. 07730 (Mexico)

    2005-01-10

    The topological properties of the charge distribution of pyrene and the three derived monoradicals in their ground state and of didehydrogenated pyrenes in the lowest singlet and triplet electronic states are discussed in detail by means of the quantum theory of atoms in molecules (TAIM) and by the electron localization function (ELF). The non-equivalence of the fused aromatic rings of pyrene prevents one from anticipating the stability and reactivity of these species from the chemistry of didehydrogenated species derived from benzene only. Whereas some of these didehydrogenated molecules were found to display a diradical character in the singlet ground state, the topological analysis reveals that others correspond to normal closed shells. Using these theoretical tools, the energetic and geometric details of o-, m- and p-benzyne-like pyrene derivatives are explained.

  14. AbstractApplication of Fenton-like process using iron nano oxides for pyrene removal from contaminated soils

    Directory of Open Access Journals (Sweden)

    S. Jorfi

    2014-05-01

    Conclusion: Fenton oxidation using iron nano oxides under defined optimum conditions and neutral pH, can be a suitable alternative to conventional Fenton for remediation of soils contaminated with pyrene.

  15. Association between mutation spectra and stable and unstable DNA adduct profiles in Salmonella for benzo[a]pyrene and dibenzo[a,l]pyrene

    Energy Technology Data Exchange (ETDEWEB)

    DeMarini, David M., E-mail: demarini.david@epa.gov [Integrated Systems Toxicology Division, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711 (United States); Hanley, Nancy M.; Warren, Sarah H.; Adams, Linda D.; King, Leon C. [Integrated Systems Toxicology Division, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711 (United States)

    2011-09-01

    Highlights: {yields} Benzo[a]pyrene (BP) induces stable DNA adducts and mutations primarily at guanine. {yields} Dibenzo[a,l]pyrene (DBP) induces them primarily at adenine. {yields} BP induces abasic sites, but DBP does not in the Salmonella mutagenicity assay. {yields} Stable DNA adducts alone appear to account for the mutation spectrum of DBP. {yields} Stable DNA adducts and possibly abasic sites account for the mutation spectrum of BP. - Abstract: Benzo[a]pyrene (BP) and dibenzo[a,l]pyrene (DBP) are two polycyclic aromatic hydrocarbons (PAHs) that exhibit distinctly different mutagenicity and carcinogenicity profiles. Although some studies show that these PAHs produce unstable DNA adducts, conflicting data and arguments have been presented regarding the relative roles of these unstable adducts versus stable adducts, as well as oxidative damage, in the mutagenesis and tumor-mutation spectra of these PAHs. However, no study has determined the mutation spectra along with the stable and unstable DNA adducts in the same system with both PAHs. Thus, we determined the mutagenic potencies and mutation spectra of BP and DBP in strains TA98, TA100 and TA104 of Salmonella, and we also measured the levels of abasic sites (aldehydic-site assay) and characterized the stable DNA adducts ({sup 32}P-postlabeling/HPLC) induced by these PAHs in TA104. Our results for the mutation spectra and site specificity of stable adducts were consistent with those from other systems, showing that DBP was more mutagenic than BP in TA98 and TA100. The mutation spectra of DBP and BP were significantly different in TA98 and TA104, with 24% of the mutations induced by BP in TA98 being complex frameshifts, whereas DBP produced hardly any of these mutations. In TA104, BP produced primarily GC to TA transversions, whereas DBP produced primarily AT to TA transversions. The majority (96%) of stable adducts induced by BP were at guanine, whereas the majority (80%) induced by DBP were at adenine

  16. Cyclic up-regulation fluorescence of pyrene excimer for studying polynucleotide kinase activity based on dual amplification.

    Science.gov (United States)

    Xu, Jing; Gao, Yanfang; Li, Baoxin; Jin, Yan

    2016-06-15

    Due to its important biological and clinical roles of polynucleotide kinase (PNK), accurate monitoring of PNK activity and inhibition is highly desirable. Herein, a homogeneous and sensitive fluorescence assay has been proposed for the detection of PNK activity by integrating target recycling signal amplification of DNA toehold strand displacement reaction (TSDR) with gamma-cyclodextrin (γ-CD) enhancement of pyrene excimer. A label-free hairpin DNA1 (H1) and two singly pyrene-labelled DNA, H2 and H3, are designed. Accompanying the occurrence of the efficient enzyme reactions, namely phosphorylation-actuated λ exonuclease reaction, a single-stranded DNA as a trigger DNA (tDNA) of TSDR can be released from H1. Then, tDNA drives circulatory interactions between H2 and H3 to continuously form H2/H3 duplex, resulting in formation of pyrene excimer and a "turn on" fluorescence signal of pyrene excimer. Furthermore, the fluorescence of pyrene excimer is further amplified by introducing gamma-cyclodextrin (γ-CD), which can regulate the space proximity of two pyrene molecules. Thus, TSDR-induced cyclic formation of pyrene excimer and γ-CD enhancement can specifically up-regulate the fluorescence of pyrene excimer for detection of PNK activity, the detection limit is 9.3 × 10(-5)UmL(-1), which is superior to those of most existing approaches. Moreover, the proposed strategy can also be successfully utilized to study inhibition efficiency of different PNK inhibitors as well. Therefore, a dual amplification approach is provided for nucleic acid phosphorylation related researches.

  17. Phthalic acid and benzo[a]pyrene in soil-plant-water systems amended with contaminated sewage sludge

    DEFF Research Database (Denmark)

    Mougin, C.; Dappozze, F.; Brault, A.

    2006-01-01

    We studied the fate of C-14-labelled phthalic acid and benzo[a]pyrene applied to the soil by the way of contaminated sewage sludge in model ecosystems allowing the simultaneous assessment of physicochemical and biological descriptors. Here we show that the mineralisation of phthalic acid is highe......[a]pyrene is recalcitrant to biodegradation whatever the type of soil contamination. We show also that the chemicals present in the sludge are poorly transferred to soil leachates and plant seedlings....

  18. Bioavailability of Pyrene Associated with Suspended Sediment of Different Grain Sizes to Daphnia magna as Investigated by Passive Dosing Devices.

    Science.gov (United States)

    Zhang, Xiaotian; Xia, Xinghui; Li, Husheng; Zhu, Baotong; Dong, Jianwei

    2015-08-18

    Suspended sediment (SPS) is widely present in rivers around the world. However, the bioavailability of hydrophobic organic compounds (HOCs) associated with SPS is not well understood. In this work, the influence of SPS grain size on the bioavailability of SPS-associated pyrene to Daphnia magna was studied using a passive dosing device, which maintained a constant freely dissolved pyrene concentration (Cfree) in the exposure systems. The immobilization and protein as well as enzymatic activities of Daphnia magna were investigated to study the bioavailability of SPS-associated pyrene. With Cfree of pyrene ranging from 20.0 to 60.0 μg L(-1), the immobilization of Daphnia magna in the presence of 1 g L(-1) SPS was 1.11-2.89 times that in the absence of SPS. The immobilization caused by pyrene associated with different grain size SPS was on the order of 50-100 μm > 0-50 μm > 100-150 μm. When pyrene Cfree was 20.0 μg L(-1), the immobilization caused by pyrene associated with 50-100 μm SPS was 1.42 and 2.43 times that with 0-50 and 100-150 μm SPS, respectively. The protein and enzymatic activities of Daphnia magna also varied with the SPS grain size. The effect of SPS grain size on the bioavailability of SPS-associated pyrene was mainly due to the difference in SPS ingestion by Daphnia magna and SPS composition, especially the organic carbon type, among the three size fractions. This study suggests that not only the concentration but also the size distribution of SPS should be considered for the development of a biological effect database and establishment of water quality criteria for HOCs in natural waters.

  19. Effect of bioaugmentation to enhance phytoremediation for removal of phenanthrene and pyrene from soil with Sorghum and Onobrychis sativa

    Science.gov (United States)

    2014-01-01

    The use of plants to remove Poly-aromatic-hydrocarbons (PAHs) from soil (phytoremediation) is emerging as a cost-effective method. Phytoremediation of contaminated soils can be promoted by the use of adding microorganisms with the potential of pollution biodegradation (bioaugmentation). In the present work, the effect of bacterial consortium was studied on the capability of Sorghum and Onobrychis sativa for the phytoremediation of soils contaminated with phenanthrene and pyrene. 1.5 kg of the contaminated soil in the ratio of 100 and 300 mg phenanthrene and/or pyrene per kg of dry soil was then transferred into each pot (nine modes). The removal efficiency of natural, phytoremediation and bioaugmentation, separately and combined, were evaluated. The samples were kept under field conditions, and the remaining concentrations of pyrene and phenanthrene were determined after 120 days. The rhizosphere as well as the microbial population of the soil was also determined. Results indicated that both plants were able to significantly remove pyrene and phenanthrene from the contaminated soil samples. Phytoremediation alone had the removal efficiency of about 63% and 74.5% for pyrene and phenanthrene respectively. In the combined mode, the removal efficiency dramatically increased, leading to pyrene and phenanthrene removal efficiencies of 74.1% and 85.02% for Onobrychis sativa and 73.84% and 85.2% for sorghum, respectively. According to the results from the present work, it can be concluded that Onobrychis sativa and sorghum are both efficient in removing pyrene and phenanthrene from contamination and bioaugmentation can significantly enhance the phytoremediation of soils contaminated with pyrene and phenanthrene by 22% and 16% respectively. PMID:24406158

  20. High-efficiency pyrene-based blue light emitting diodes: Aggregation suppression using a calixarene 3D-scaffold

    KAUST Repository

    Chan, Khaileok

    2012-01-01

    An efficient blue light emitting diode based on solution processable pyrene-1,3-alt-calix[4]arene is demonstrated, providing a record current efficiency of 10.5 cd A -1 in a simple non-doped OLED configuration. Complete suppression of pyrene aggregation in the solid state is achieved by controlling chromophore dispersion using the 1,3-alt-calix[4]arene scaffold. © 2012 The Royal Society of Chemistry.

  1. Combined remediation of pyrene-contaminated soil with a coupled system of persulfate oxidation and phytoremediation with ryegrass.

    Science.gov (United States)

    Chen, Xiao; Li, Hongbing; Liu, Xiaoyan; Zhang, Xinying; Liang, Xia; He, Chiquan; Cao, Liya

    2016-10-01

    The in situ chemical oxidation technology (ISCO) and phytoremediation for PAHs have been studied respectively, but few focus on the feasibility of combining persulfate with ryegrass. This literature revealed the effect of persulfate oxidation on the growth of ryegrass and the removal ratios of pyrene in the couple system of persulfate oxidation and phytoremediation. The results demonstrated that half of pyrene in test soil was oxidized by persulfate in 7 days and then the residual pyrene concentration was decreased to a lower level by ryegrass in the following 2 months in oxidation treatment and drip washing and plants (OWP) and oxidation treatment and drip washing and plants and fertilization (OWFP) treatment. Ryegrass could grow well after persulfate oxidation with the oxidized soil washed by water. Ryegrass in OWP and OWFP treatments had higher ratios of overground and underground biomass. However, the seeds of ryegrass cannot germinate when drip washing was omitted. Pyrene together with residual persulfate changed soil enzyme activities. Drip washing and the growth of ryegrass made soil enzyme activities tend to returned to normal levels. Persulfate oxidation and phytoremediation were compatible to make contributions to the dissipation of pyrene. Persulfate oxidation activated by heat had higher removal efficiency of PAHs and phytoremediation could further decrease the pyrene concentration in spiked soil.

  2. Pyrene appended bile acid conjugates: Synthesis and a structure-gelation property study

    Indian Academy of Sciences (India)

    Shreedhar Bhat; Arto Valkonen; Juha Koivukorpi; Anupama Ambika; Erkki Kolehmainen; Uday Maitra; Kari Rissanen

    2011-07-01

    A wide variety of novel compounds obtained by combining two types of known organogelators, viz., bile acid alkyl amides and pyrene alkanoic acids, were synthesized and screened for their gelation ability. The 3 esters of 1-pyrene butyric acid (PBA) of alkylamides of deoxycholic acid (DCA) turned out to be effective in the gel formation with many organic solvents although the gelation has to be triggered by the addition of a charge transfer (CT) agent 2,4,7-trinitrofluorenone (TNF). The special feature of these molecules is that the organogelation is achieved only after derivatizing the acid moiety of the 1-pyrenealkanoic acids. Additionally, the gelation properties can be fine-tuned by inserting different functional groups at the bile acid side chain. The gels obtained are deep red in colour and optically transparent up to 2% w/v. The SEM studies of the obtained xerogels revealed bundled rod-like morphology without specialized branching.

  3. Charge-transfer interaction mediated organogels from 18β-glycyrrhetinic acid appended pyrene

    Directory of Open Access Journals (Sweden)

    Jun Hu

    2013-12-01

    Full Text Available We describe herein the two-component charge-transfer (CT interaction induced organogel formation with 18β-glycyrrhetinic acid appended pyrene (GA-pyrene, 3 as the donor, and 2,4,7-trinitrofluorenone (TNF, 4 as the acceptor. The use of TNF (4 as a versatile electron acceptor in the formation of CT gels is demonstrated through the formation of gels in a variety of solvents. Thermal stability, stoichiometry, scanning electron microscopy (SEM, optical micrographs, and circular dichroism (CD are performed on these CT gels to investigate their thermal and assembly properties. UV–vis, fluorescence, mass spectrometric as well as variable-temperature 1H NMR experiments on these gels suggest that the CT interaction is one of the major driving forces for the formation of these organogels.

  4. Effects of benzo(a)pyrene on food assimilation and growth efficiency of Porcellio scaber (Isopoda)

    Energy Technology Data Exchange (ETDEWEB)

    Straalen, N.M. van; Verweij, R.A. (Vrije Univ., Amsterdam (Netherlands))

    1991-01-01

    Although the metabolic effects of benzo(a)pyrene have been investigated extensively in rodents, little is known about its effects in the terrestrial environment and nothing is known about its effects on soil invertebrates. In this study, the authors have chosen the woodlouse Porcellio scaber (Latr.) (Crustacea, Isopoda) as a representative from the soil invertebrate community. Experiments were designed to analyze the consequences of benzo(a)pyrene exposure for the energy metabolism. The partitioning of energy between respiration and scope for growth is considered as an ecologically relevant criterion for studying effects of contaminants in the environment. PAH might affect this partitioning by inducing biotransformation reactions that make demands on the assimilated energy.

  5. Occupational exposure to coal tar pitch volatiles, benzo/a/pyrene and dust in tyre production.

    Science.gov (United States)

    Rogaczewska, T; Ligocka, D

    1994-01-01

    Occupational exposure to coal tar pitch volatiles (CTPVs), benzo/a/pyrene (BaP) and dust was evaluated by means of individual measurements carried out in 80 workers and by stationary measurements on 16 work-posts in two divisions of the tyre producing plant. Dust and coal tar pitch volatiles concentrations in the air were determinated by the gravimetric method, measured, in the case of CPTVs, benzene-soluble fraction (BSF) with ultrasonic extraction. Benzo/a/pyrene analysis was performed using high performance liquid chromato-graphy (HPLC) with a spectrofluorimetric detector. It was found that nearly all personal sampling results for BaP were within the range 90%) which exceeded the admissible value (4 mg/m3) was found mainly only in the workers of the Semiproducts Division at some work-posts.

  6. Biotin-mediated epigenetic modifications: Potential defense against the carcinogenicity of benzo[a]pyrene.

    Science.gov (United States)

    Xia, Bo; Pang, Li; Zhuang, Zhi-xiong; Liu, Jian-jun

    2016-01-22

    Environmental pollution and an unhealthy lifestyle result in direct exposure to dangerous chemicals that can modify endogenous pathways and induce malignant transformation of human cells. Although the molecular mechanisms of tumorigenesis are still not well understood, epigenetic alteration may be associated with exogenous chemical-induced carcinogenicity. Given the association between nutrition and cancer, nutrient supplementation may reduce aberrant epigenetic modifications induced by chemicals, thus decreasing carcinogenesis. This paper provides an overview of the epigenetic events caused by benzo[a]pyrene, a procarcinogenic and environmental pollutant, and biotin, an essential water-soluble vitamin, and investigates potential connections between them. This paper also discusses the potential inhibitory effect of biotin-related epigenetic modifications on the carcinogenicity of benzo[a]pyrene. The effect of nutritional supplementation on tumorigenesis involving epigenetic modifications is also discussed.

  7. Biodegradation of pyrene and catabolic genes in contaminated soils cultivated with Lolium multiflorum L

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Sardar [Dept. of Environmental Sciences, Univ. of Preshawar (Pakistan); Hesham, Abd El-Latif [Genetics Dept., Faculty of Agriculture, Assiut Univ. (Egypt); Qing Gu; Shuang Liu; He Jizheng [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences (China)

    2009-10-15

    Background, aim, and scope In the soil environment, polycyclic aromatic hydrocarbons (PAHs) and heavy metals (HMs) are of great environmental and human health concerns due to their widespread occurrence, persistence, and carcinogenic properties. Bioremediation of contaminated soil is a cost-effective, environmentally friendly, and publicly acceptable approach to address the removal of environmental contaminants. However, biore-mediation of contaminants depends on plant-microbe interactions in the rhizosphere. The microorganisms that can mineralize various PAHs have PAH dioxygenase genes like nahAc, phnAc, and pdol. To understand the fate of pyrene in rhizospheric and non-rhizospheric soils in the presence or absence of Pb, pyrene biodegradation, bacterial community structure, and dioxygenase genes were investigated in a pot experiment. (orig.)

  8. Effects of Nereis diversicolor on the Transformation of 1-Methylpyrene and Pyrene

    DEFF Research Database (Denmark)

    Malmquist, Linus Mattias Valdemar; Christensen, Jan Henning; Selck, Henriette

    as the most prominent metabolite. Transformation of 1-methylpyrene (21% transformed) was more than 3 times as efficient as pyrene transformation (5.6% transformed). Because crude oils contain larger amounts of C1−C4-substituted PAHs than nonsubstituted PAHs, the rapid and efficient transformation of sediment......Transformation of nonsubstituted and alkyl-substituted polycyclic aromatic hydrocarbons (PAHs) by the benthic invertebrate Nereis diversicolor was compared in this study. Pyrene and 1-methylpyrene were used as model compounds for nonsubstituted and alkyl-substituted PAHs, respectively. Qualitative...... and quantitative analyses of metabolites and parent compounds in worm tissue, water, and sediment were performed. Transformation of 1-methylpyrene generated the benzylic hydroxylated phase I product, 1-pyrenecarboxylic acid that comprised 90% of the total metabolites of 1-methylpyrene, and was mainly found...

  9. Effects of Nereis diversicolor on the Transformation of 1‑Methylpyrene and Pyrene

    DEFF Research Database (Denmark)

    Malmquist, Linus Mattias Valdemar; Christensen, Jan Henning; Selck, Henriette

    2013-01-01

    as the most prominent metabolite. Transformation of 1-methylpyrene (21% transformed) was more than 3 times as efficient as pyrene transformation (5.6% transformed). Because crude oils contain larger amounts of C1−C4-substituted PAHs than nonsubstituted PAHs, the rapid and efficient transformation of sediment......Transformation of nonsubstituted and alkyl-substituted polycyclic aromatic hydrocarbons (PAHs) by the benthic invertebrate Nereis diversicolor was compared in this study. Pyrene and 1-methylpyrene were used as model compounds for nonsubstituted and alkyl-substituted PAHs, respectively. Qualitative...... and quantitative analyses of metabolites and parent compounds in worm tissue, water, and sediment were performed. Transformation of 1-methylpyrene generated the benzylic hydroxylated phase I product, 1-pyrenecarboxylic acid that comprised 90% of the total metabolites of 1-methylpyrene, and was mainly found...

  10. Photodissociation studies of calcium-coronene and calcium-pyrene cation clusters

    Science.gov (United States)

    Scott, A. C.; Buchanan, J. W.; Flynn, N. D.; Duncan, M. A.

    2008-01-01

    Gas-phase cluster cations combining calcium atoms and the polycyclic aromatic hydrocarbons (PAHs) coronene (C24H12) and pyrene (C16H10) are produced in a molecular beam using laser vaporization in a pulsed nozzle cluster source. Time-of-flight mass spectrometry reveals the formation of clusters of the form Cax(coronene)y+ for up to x = 4 and y = 3 and Cax(pyrene)y+ for up to x = 2 and y = 3. Mass-selected photodissociation studies show that the calcium cation is the most prominent fragment for each system. Photoinduced calcium carbide formation is prominent when two or more calcium atoms are present. Additionally, there is evidence that these clusters can form sandwich structures.

  11. 1,3-Bis(pyren-1-ylimidazolium chloride (IPyr·HCl

    Directory of Open Access Journals (Sweden)

    Peter Schroll

    2011-06-01

    Full Text Available A novel UV-A-light absorbing N-heterocyclic carbene precursor imidazolium salt 2 was synthesized by reaction of 1,4-bis(pyren-1-yl-1,4-diazadiene 1 with paraformaldehyde in the presence of chlorotrimethylsilane. The title compound was characterized by 1H-NMR, 13C-NMR, 2D-NMR, mass spectrometry, IR and UV/VIS spectroscopy.

  12. 1,3-Bis(pyren-1-yl)imidazolium chloride (IPyr·HCl)

    OpenAIRE

    Peter Schroll; Burkhard König

    2011-01-01

    A novel UV-A-light absorbing N-heterocyclic carbene precursor imidazolium salt 2 was synthesized by reaction of 1,4-bis(pyren-1-yl)-1,4-diazadiene 1 with paraformaldehyde in the presence of chlorotrimethylsilane. The title compound was characterized by 1H-NMR, 13C-NMR, 2D-NMR, mass spectrometry, IR and UV/VIS spectroscopy.

  13. Benzo (a) pyrene induced tumorigenesity of human immortalized oral epithelial cells: transcription profiling

    Institute of Scientific and Technical Information of China (English)

    LI Jin-zhong; PAN Hong-ya; ZHENG Jia-wei; ZHOU Xiao-jian; ZHANG Ping; CHEN Wan-tao; ZHANG Zhi-yuan

    2008-01-01

    Background The present study was designed to examine and analyze the global gene expression changes during the tumorigenesis of a human immortalized oral epithelial cell line, and search for the possible genes that may play a role in the carcinogenesis of oral cancer associated with benzo (a) pyrene.Methods The human immortalized oral epithelial cells, which have been established through transfection of E6/E7 genasof human papillomavirus type 16 and proved to be non-tumorigenic in nude mice, were treated with benzo (a) pyrene.Tumorigenesity of the treated cells were examined through nude mice subcutaneous injection. The global gene expression profiles of immortalized cells and the tumorigenic cells were acquired through hybridization of a microarray of Affymetrix U133 plus 2.0. The data were analyzed using Spring 7.0 software and treated statistically using one-way analysis of variance (ANOVA). The differentially expressed genes were classified using a Venn diagram and annotated with gene ontology. Several highlighted genes were validated in cells using a real-time polymerase chain reaction.Results There were 883 differentially expressed genes during the tumorigenesis and most of them changed expression in the early stage of tumorigenesis. These genes mainly involved in macromolecule metabolism and signal transduction,possessed the molecular function of transition metal ion binding, nucleotide binding and kinase activity; their protein products were mainly integral to membranes or localized in the nucleus and cytoskeleton. The expression patterns of IGFBP3, S100A8, MAP2K, KRT6B, GDF15, MET were validated in cells using a real-time polymerase chain reaction; the expression of IGFBP3 was further validated in clinical oral cancer specimens.Concluslona This study provides the global transcription profiling associated with the tumorigenesis of oral epithelial cells exposed to benzo (a) pyrene; IGFBP3 may play a potential role in the initiation of oral cancer related to

  14. Benzo[a]Pyrene: biodegradation by different Trametes versicolor Morphology and enzymatic studies

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, L.; Xavier Gabarrell, X.; Vicent, T.

    2009-07-01

    Benzo[a]pyrene (BaP), a persistent organic pollutant included in the polycyclic aromatic hydrocarbons group (PAH), is of environmental concern due to its known carcinogenicity and bioaccumulation potential. Because of its toxic properties, it is included in the european community (EC) and United States Environmental Agency (EPA) priority pollutant list resulting in a much more strict regulation and complex tasks to be accomplished for remediation of PAH contaminated environments. (Author)

  15. Degradation of phenanthrene, fluorene, fluoranthene, and pyrene by a Mycobacterium sp

    Energy Technology Data Exchange (ETDEWEB)

    Boldrin, B.; Tiehm, A.; Fritzsche, C. (Universitaet Karlsruhe (Germany))

    1993-06-01

    Contamination of the environment with polycyclic aromatic hydrocarbons are considered hazardous so remediation of contaminated sites is of interest. This paper describes the isolation and characterization of a scotochromogenic Mycobacterium sp. that metabolizes pyrene, flouranthene, phenanthrene, and several other aromatic compounds as sole carbon sources. Exponential, non-substrate-limited degradation and growth as characteristic parameters of the bacterium are investigated. 26 refs., 1 fig., 2 tabs.

  16. Proteomic analysis of the marine diatom Thalassiosira pseudonana upon exposure to benzo(a)pyrene

    OpenAIRE

    Carvalho, Raquel N.; Lettieri, Teresa

    2011-01-01

    Background Polycyclic aromatic hydrocarbons (PAHs) are environmental pollutants ubiquitously distributed. They are generated by incomplete combustion of organic materials such as wood or fossil fuels. Due to their carcinogenic, mutagenic effects and to their wide distribution in the environment, these pollutants pose many concerns to researchers and regulators. In our laboratories we investigated the effect of benzo(a)pyrene (BaP) exposure in the marine diatom Thalassiosira pseudonana, which ...

  17. Application of Multimedia Fugacity Model to Assess the Environmental Fate of Benzo (a Pyrene

    Directory of Open Access Journals (Sweden)

    Theoneste Ntakirutimana

    2012-07-01

    Full Text Available This study was undertaken in order to assess the environmental fate of Benzo (a pyrene. We have highlighted the behavior of Benzo (a pyrene in multimedia environment or biosphere of air, water, soil and sediments. Equilibrium Criterion (EQC model which is used to evaluate the environmental fate of Polycyclic Aromatic Hydrocarbons (PAHs is used as our tool. The structure of the model and the required input data are presented. By undertaking a sequence of level I, II and III calculations, increasing information is obtained about the chemical’s partitioning, environmental process and chemical characteristics that influence chemical fate, its susceptibility to transformation and transport from one media to another. Output data, consisting of diagrams, give a complete picture of Benzo (a pyrene’s fate in an evaluative environment. The role of this model as a tool for assessing the fate of Benzo (a pyrene is discussed. We suggested that this assessment can serve as a template which can be applied to other chemicals and groups of chemicals which are present in the environment.

  18. Flux of benzo(a)pyrene to the ground surface and its distribution in the ecosystem

    Energy Technology Data Exchange (ETDEWEB)

    Milukaite, A. [Institute of Physics, Vilnius (Lithuania)

    1998-07-01

    Benzo(a)pyrene (BP) has been investigated in bulk atmospheric deposition, moss, needles of pine and some species of vascular plants. At two remote Lithuanian sites, for 1990-1995 the flux of benzo(a)pyrene from the atmosphere to the ground surface varied between 0.3 to 4.8 {mu}g{sup -2} mo{sup -1}. Consequently the territory of Lithuania (65,000 km{sup 2}) yearly was exposed to 624-2574 kg of carcinogen. The distribution of BP in soil and various vascular plant tissues (trifolium tepens, Elitrygea repens, Thymus serpyllum) indicates that benzo(a)pyrene is assimilated by flora. The concentration of BP is different in various organs of vascular plants and mostly depends on the degree of soil pollution. More than 300 samples of moss, mostly Hylocomium spendens and Pleurozium schreberi were analysed for BP. From 3.1 to 896.0 {mu}g kg{sup -1} of BP were measured in the moss samples. The flux of BP to the ground surface correlates well with its concentration in moss. A map of BP flux across Lithuania was created. 20 refs., 3 figs., 3 tabs.

  19. Influence of organic coatings on pyrene ozonolysis at the air-aqueous interface.

    Science.gov (United States)

    Henderson, Elyse A; Donaldson, D J

    2012-01-12

    Glancing angle laser-induced fluorescence was used to investigate the effects of organic monolayer coatings on the ozonation kinetics of pyrene at the air-aqueous interface. Fluorescence spectra show that both 1-octanol and octanoic acid coatings give rise to similar decreased polarity at the interface relative to the uncoated surface and show a similar propensity of pyrene to partition to the interface. Ozonation kinetics follow a Langmuir-Hinshelwood mechanism, indicating a surface reaction. At high ozone concentrations, a monolayer coating of 1-octanol enhances the rate relative to the uncoated surface and a coating of octanoic acid decreases the rate. Pyrene fluorescence is most efficiently quenched by ozone in the presence of a 1-octanol coating, followed by the uncoated surface, and least efficiently quenched by ozone in the presence of octanoic acid. In agreement with earlier work, a significant photoenhancement of the ozonation is observed at the uncoated surface; however, no enhancement is observed with monolayer coatings of either organic. Quantum chemical calculations indicate a reasonable binding of ozone by the carboxylic acid group (in both its dissociated and undissociated forms). We suggest that the inhibition of the water surface reaction by a monolayer of octanoic acid is due to the sequestration of ozone by the carboxylic acid group.

  20. Photoactive hybrid material based on pyrene functionalized PbS nanocrystals decorating CVD monolayer graphene.

    Science.gov (United States)

    Ingrosso, Chiara; Bianco, Giuseppe V; Corricelli, Michela; Comparelli, Roberto; Altamura, Davide; Agostiano, Angela; Striccoli, Marinella; Losurdo, Maria; Curri, M Lucia; Bruno, Giovanni

    2015-02-25

    A simple and facile solution-based procedure is implemented for decorating a large area, monolayer graphene film, grown by chemical vapor deposition, with size-tunable light absorbing colloidal PbS nanocrystals (NCs). The hybrid is obtained by exposing a large area graphene film to a solution of 1-pyrene butyric acid surface coated PbS NCs, obtained by a capping exchange procedure onto presynthesized organic-capped NCs. The results demonstrate that at the interface, multiple and cooperative π-π stacking interactions promoted by the pyrene ligand coordinating the NC surface lead to a successful anchoring of the nano-objects on the graphene platform which concomitantly preserves its aromatic structure. Interligand interactions provide organization of the nano-objects in highly interconnected nanostructured multilayer coatings, where the NCs retain geometry and composition. The resulting hybrid exhibits a sheet resistance lower than that of bare graphene, which is explained in terms of electronic communication in the hybrid, due to the interconnection of the NC film and to a hole transfer from photoexcited PbS NCs to graphene, channelled at the interface by pyrene. Such a direct electron coupling makes the manufactured hybrid material an interesting component for optoelectronics, sensors and for optical communication and information technology.

  1. Water solubility enhancements of pyrene by single and mixed surfactant solutions

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Water solubility enhancements of pyrene by both single-surfactant and mixed-surfactant solutions were compared andevaluated. The solubility of pyrene in water was greatly enhanced by each of Triton X-100 (TX100), Triton X-405 (TX405), Brij 35 and SDS, in which the water solubility enhancements increased with increasing surfactant concentrations. The extent of solubility enhancements at surfactant concentrations below the CMC is the order of TX100 > Brij 35 > TX405 > SDS; the sequence at surfactantconcentrations above the CMC is TX100 > Brij 35 > SDS > TX405. Pyrene was solubilized synergistically by anionic-nonionic mixed surfactant solutions, especially at low surfactant concentrations. The synergistic power of the mixed surfactants is SDS-TX405 > SDS-Brij 35 > SDS-TX100. The synergism as noted is attributed to increasing Kmc and/or decreasing the CMC of the mixed surfactan solution. For SDS-TX405 and SDS-Brij 35 mixed surfactant solutions, an increase in Kmc is coupled with a decrease in the CMC; for SDS-TX100, only a decreased in the CMC value is noted. Mixed-surfactant solutions may improve the performance of the surfactant-enhanced remediation (SER) of soils by increasing the bioavailability and biodegradation of non-aqueous-phase organic pollutants and reducing the level of surfactant pollution and remediation expenses.

  2. Pyrene metabolites in the hepatopancreas and gut of the isopod Porcellio scaber, a new biomarker for polycyclic aromatic hydrocarbon exposure in terrestrial ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Stroomberg, G.J.; Knecht, J.A. de; Ariese, F.; Gestel, C.A.M. Van; Velthorst, N.H.

    1999-10-01

    The object of this study was to investigate the formation of pyrene metabolites by the isopod Porcellio scaber as a possible tool in the environmental risk assessment of polycyclic aromatic hydrocarbon (PAH) exposure in terrestrial ecosystems. The formation of pyrene metabolites was studied after either pulse exposure to a single high dose, or prolonged exposure (14 d) to a lower dosage. Exposure studies were carried out with unlabeled or radiolabeled pyrene, ion pair chromatography was used for analysis, and reference conjugates were synthesized. The authors also measured pyrene metabolites in field-exposed animals, to explore their use as biomarkers of PAH exposure. Analysis of the hepatopancreas and gut of single isopods revealed the formation of five products, one of which was 1-hydroxypyrene. Four of the remaining products were identified as phase 2 metabolites of 1-hydroxypyrene, with UV absorption and fluorescence characteristics similar to that of pyrene. One metabolite was identified as pyrene-1-glucoside, which is in accordance with high rates of glucosidation, reported for these isopods. Another conjugate was identified as pyrene-1-sulfate. None of the metabolites coeluted with a pyrene-1-glucuronide reference obtained from fish bile. A fifth metabolite detected by on-line scintillation detection did not exhibit any absorption at 340 nm, possibly because one of the aromatic rings of pyrene had lost its aromatic character. Although pyrene is not known for its toxicity, it usually co-occurs with other PAHs that are transformed into toxic products. Investigating the metabolism of pyrene can provide information with regard to the biotransformation capacity of invertebrate species and uptake and elimination kinetics. Because pyrene is one of the most predominant PAHs in the environment, analysis of its metabolites provides an extra tool for the environmental risk assessment of ecosystems with regard to PAH exposure, bioavailability, and biotransformation.

  3. In vivo and in vitro percutaneous absorption of [{sup 14}C]pyrene in sprague dawley male rats: skin reservoir effect and consequence on urinary 1-OH pyrene excretion

    Energy Technology Data Exchange (ETDEWEB)

    Payan, Jean-Paul; Lafontaine, Michel; Simon, Patrice; Marquet, Fabrice; Champmartin-Gendre, Catherine; Beydon, Dominique; Ferrari, Elisabeth [Institut National de Recherche et de Securite, Vandoeuvre (France)

    2008-10-15

    The skin reservoir effect of [{sup 14}C]pyrene (in vivo and in vitro) on percutaneous absorption was determined in male Sprague Dawley rats. The urinary 1-OHpyrene (1-OHPy) excretion was compared between dermal exposure and intravenous administration. In vivo, the percutaneous absorption flux of [{sup 14}C]pyrene (200 {mu}g/cm{sup 2}; 50 {mu}L/cm{sup 2} of ethanol) determined by sacrificing batches of rats after different exposure times over 4.5 h was 1.0{+-}0.1 {mu}g/cm{sup 2} h{sup -1}. During exposure, penetration flux was twofold higher than absorption flux, indicating a gradual accumulation of pyrene in the skin. [{sup 14}C] skin content at the end of exposure was 16{mu}g/cm{sup 2}, which decreased gradually over time to 2 {mu}g/cm{sup 2} 68 h after the end of exposure. The total absorbed dose during exposure was threefold lower than that after exposure, indicating a high contribution of pyrene skin content to the systemic availability of the compound. Similar results were obtained in vitro. The apparent elimination rate of [{sup 14}C]pyrene (23 h) contained in the skin after an exposure of 4.5 h was similar to the apparent urinary excretion half life of 1-OHPy (21 h). These values are threefold higher than the urinary excretion half life of 1-OHPy after an intravenous administration of pyrene (0.5 mg/kg). In conclusion, absorbed dose and percutaneous absorption flux were well estimated from the 1-OHPy urinary excretion rate. For risk assessment purposes, the penetration flux rather than the absorption flux should be taken into account for topical pyrene exposure. (orig.)

  4. Microcalorimetric investigation of the effect of non-ionic surfactant on biodegradation of pyrene by PAH-degrading bacteria Burkholderia cepacia.

    Science.gov (United States)

    Chen, Ke; Zhu, Qing; Qian, Yiguang; Song, Ying; Yao, Jun; Choi, Martin M F

    2013-12-01

    Polycyclic aromatic hydrocarbons (PAHs) are widespread in various ecosystems and are pollutants of great concern due to their potential toxicity, mutagenecity and carcinogenicity. Surfactant has become a hot topic for its wide application in the bioremediation of PAHs. The aim of this work is to explore a microcalorimetric method to determine the toxic effect of pyrene on Bacillus subtilis (B. subtilis) and the PAH-degrading bacteria Burkholderia cepacia (B. cepacia) and to evaluate the effect of Tween 80 on biodegradation of pyrene. Power-time curves were studied and calorimetric parameters including the growth rate constant (k), half inhibitory concentration (IC₅₀), and total thermal effect (Q(T)) were determined. B. subtilis, B. cepacia and B. cepacia with Tween 80 were completely inhibited when the concentration of pyrene were 200, 800 and 1600 µg mL⁻¹, respectively. B. cepacia shows better tolerance to pyrene than B. subtilis. Tween 80 significantly improves the biodegradation of pyrene by increasing the bioavailability of pyrene. In addition, the expression of catechol 2,3-dioxygenase (C23O) in B. cepacia is responsible for the degradation of pyrene and plays an important role in improving the biodegradation of pyrene. Moreover, the activity of C23O increases with the application of Tween 80. The enhanced bioavailability and biodegradation of pyrene by Tween 80 shows the potential use of Tween 80 in the PAHs bioremediation.

  5. A two-stage process using electrokinetic remediation and electrochemical degradation for treating benzo[a]pyrene spiked kaolin.

    Science.gov (United States)

    Gómez, J; Alcántara, M T; Pazos, M; Sanromán, M A

    2009-03-01

    An innovative process that combines soil electrokinetic remediation and liquid electrochemical oxidation for the degradation of organic compounds present in a polluted soil was developed and evaluated by using benzo[a]pyrene spiked kaolin. In order to increase benzo[a]pyrene solubility during electrokinetic treatment, the addition of a co-solvent or surfactant, such as ethanol or Brij 35, as flushing solution was tested. The research carried out demonstrated the influence of the desorption agent employed on benzo[a]pyrene remediation from the kaolin matrix. Thus, if the flushing solution was ethanol at 40%, there was no presence of contaminant in either chamber. On the contrary, when a solution of surfactant Brij 35 was used, benzo[a]pyrene was transported towards the cathode chamber, where it was collected. Moreover, the extent of this recovery depends on the pH profile on the soil. When no pH control was used, around 17% of initial contaminant was detected in the cathode chamber; however, when pH control was applied, the recovery of benzo[a]pyrene could be higher than 76%, when the pH control in the anode chamber was set at 7.0. In order to obtain the total degradation of mobilised benzo[a]pyrene from the contaminated soil, the liquid collected by electrokinetic remediation was oxidised by electrochemical treatment. This oxidation was accomplished via an electrochemical cell with a working volume of 0.4 L, and graphite as electrode material. The benzo[a]pyrene was almost totally degraded in 1d, reaching a degradation of about 73% in 16 h.

  6. Effect of pyrene on hepatic cytochrome P450 1A (CYP1A) expression in Nile Tilapia (Oreochromis niloticus).

    Science.gov (United States)

    Zapata-Pérez, O; Gold-Bouchot, G; Ortega, A; López, T; Albores, A

    2002-05-01

    The effect of pyrene on the regulation of the gene expression of cytochrome P4501A ( CYP1A) was studied in tilapia (Oreochromis niloticus), a tropical fish of great ecological and economical importance. To evaluate CYP1A mRNA, tilapia CYP1A cDNA was cloned, sequenced, and compared with those CYP1A reported sequences in the GeneBank DNA database. The top seven matches corresponded to CYP1A from other teleosts. Hepatic CYP1A mRNA levels showed a significant increase at day 1 after pyrene injection (20 mg kg(-1) body weight [BW]), and this CYP1A mRNA levels did not return to basal levels for up to 5 days. The immunoblot analysis of CYP1A protein levels using polyclonal rabbit-anti-trout antibodies in the liver of pyrene-treated (20 mg kg(-1) BW) tilapias showed a 1.9-fold increase at day 3 after injection. Ethoxyresorufin- O-deethylase (EROD) activity increased 18-fold with respect to control fish at day 3 after injection. CYP1A protein and EROD activity remained increased for 5 days after a single pyrene IP administration. Similarly, the highest concentration of 1-hydroxypyrene (1-OH pyrene) in bile was observed in fish sacrificed at day 3 after injection. EROD activity and 1-OH pyrene concentration showed a statistically significant correlation (r = 0.85) according to the Spearman test, suggesting the participation of this cytochrome in the biotransformation of pyrene.

  7. Importance of suspended sediment (SPS) composition and grain size in the bioavailability of SPS-associated pyrene to Daphnia magna.

    Science.gov (United States)

    Xia, Xinghui; Zhang, Xiaotian; Zhou, Dong; Bao, Yimeng; Li, Husheng; Zhai, Yawei

    2016-07-01

    Hydrophobic organic compounds (HOCs) tend to associate with suspended sediment (SPS) in aquatic environments; the composition and grain size of SPS will affect the bioavailability of SPS-associated HOCs. However, the bioavailability of HOCs sorbed on SPS with different compositions and grain sizes is not well understood. In this work, passive dosing devices were made to control the freely dissolved concentration of pyrene, a typical HOC, in the exposure systems. The effect of pyrene associated with amorphous organic carbon (AOC), black carbon (BC), and minerals of SPS with grain sizes of 0-50 μm and 50-100 μm on the immobilization and enzymatic activities of Daphnia magna was investigated to quantify the bioavailability of pyrene sorbed on SPS with different grain sizes and compositions. The results showed that the contribution of AOC-, BC-, and mineral-associated pyrene to the total bioavailability of SPS-associated pyrene was approximately 50%-60%, 10%-29%, and 20%-30%, respectively. The bioavailable fraction of pyrene sorbed on the three components of SPS was ordered as AOC (22.4%-67.3%) > minerals (20.1%-46.0%) > BC (9.11%-16.8%), and the bioavailable fraction sorbed on SPS of 50-100 μm grain size was higher than those of 0-50 μm grain size. This is because the SPS grain size will affect the ingestion of SPS and the SPS composition will affect the desorption of SPS-associated pyrene in Daphnia magna. According to the results obtained in this study, a model has been developed to calculate the bioavailability of HOCs to aquatic organisms in natural waters considering both SPS grain size and composition.

  8. Self-Assemblies of Single-Walled Carbon Nanotubes through Tunable Tethering of Pyrenes by Dextrin for Rapidly Chiral Sensing

    Directory of Open Access Journals (Sweden)

    Wei-Li Wei

    2011-01-01

    Full Text Available Pyrene-modified dextrin (Py-Dex was synthesized via the Schiff base reaction between reducing end of dextrins and 1-aminopyrene, and then self-assemblies of single-walled carbon nanotubes (SWNTs were fabricated through the tunable tethering of pyrene to SWNTs by dextrin chains. The Py-Dex-SWNTs assemblies were found to be significantly water-soluble because of the synergistic effect of dextrin chains and pyrene moieties. Py-Dex and Py-Dex-SWNTs were adequately characterized by NMR, UV-vis, fluorescence spectroscopy, Raman spectroscopy, matrix-assisted laser desorption/ionization-time of flight mass spectroscopy, and transmission electron microscopy. The tethering effect of dextrin toward pyrene moieties was clearly revealed and was found to be tunable by adjusting the length of dextrin chains. The fluorescence of pyrene moieties was sufficiently quenched by SWNTs with the support of dextrin chains. Furthermore, the Py-Dex-SWNTs assemblies were used for chiral selective sensing by introducing cyclodextrins as chiral binding sites. The rapid chiral sensing was successfully tested for different enantiomers.

  9. Uptake of 7,12-dimethylbenz(a)anthracene and benzo(a)pyrene in melanin-containing tissues

    Energy Technology Data Exchange (ETDEWEB)

    Roberto, A.; Larsson, B.S. [Uppsala Univ., Dept. of Pharmaceutical Biosciences, Div. of Toxicology, Uppsala (Sweden); Tjaelve, H. [The Swedish Univ. of Agricultural Sciences, Dept. of Pharmacology and Toxicology, Uppsala (Sweden)

    1996-08-01

    It is widely accepted that UV exposure is the main etiological factor for malignant melanoma. Epidemiologic studies, however, have indicated that also chemical carcinogens may be a risk factor for the disease. Polycyclic aromatic hydrocarbons such as 7,12-dimethylbenz(a)anthracene and benzo(a)pyrene represent an important class of carcinogenic chemicals. It is known that 7,12-dimethylbenz(a)anthracene can induce melanotic tumours in various animal species, and human melanocytes in culture have been found to be capable of metabolizing benzo(a)pyrene to its proximate carcinogen benzo(a)pyrene-7,8-diol. In the present study the disposition of {sup 14}C- and {sup 3}H-7,12-dimethylbenz(a)anthracene and {sup 14}C-benzo(a)pyrene was studied in pigmented and albino mice and Syrian golden hamsters by whole-body autoradiography. The results showed pronounced retention of label in the melanin-containing structures of the eyes and the hair follicles in the pigmented animals. The labelling of the corresponding structures in the albino animals was low. Additional experiments showed that 7,12-dimethylbenz(a)anthracene and benzo(a)pyrene as well as some of their metabolites are bound to melanin in vitro. The specific localization of the polycyclic aromatic hydrocarbons in pigmented tissues due to melanin affinity, combined with bioactivating capacity of melanocytes, suggest that these substances may play a role in the induction of malignant melanoma. (au).

  10. Thermodynamic and structural study of pyrene-1-carboxaldehyde/DNA interactions by molecular spectroscopy: Probing intercalation and binding properties

    Science.gov (United States)

    Grueso, E.; Prado-Gotor, R.

    2010-08-01

    The binding of pyrene-1-carboxaldehyde (1-PyCHO) with ctDNA was investigated through absorption, intrinsic and induced circular dichroism, viscosity measurements and steady-state fluorescence. The binding and the number of monomer units of the polymer involved in the binding of one dye molecule (site size) have been quantified. The results indicated that the 1-PyCHO molecule binds to the ctDNA in an intercalative mode. The spectroscopic evidence of this intercalation process is also corroborated by the effect of urea, iodide-induced fluorescence quenching of pyrene-1-carboxaldehyde and competitive binding using a fluorescent intercalator, SYBR Green I (SG). The induced circular dichroism (ICD) spectra of pyrene-1-carboxaldehyde complexed with ctDNA show that pyrene-1-carboxaldehyde intercalates into ctDNA and that the intercalation orientation of pyrene to the DNA base-pairs long axis is heterogeneous. On the other hand, the intrinsic circular dichroism (CD) spectra show a stabilization of the right-handed B form of ctDNA, due to the intercalation process.

  11. Conditions for effective removal of pyrene from an artificially contaminated soil using Pseudomonas aeruginosa 57SJ rhamnolipids

    Energy Technology Data Exchange (ETDEWEB)

    Bordas, Francois [Institut national de la recherche scientifique, Centre INRS-Eau-Terre-Environnement, Universite du Quebec, 2800 rue Einstein, C.P. 7500, Sainte-Foy, Quebec, G1V 4C7 (Canada)]. E-mail: francois.bordas@unilim.fr; Lafrance, Pierre [Institut national de la recherche scientifique, Centre Eau, Terre et Environnement, Universite du Quebec, 490, rue de la Couronne, Quebec, G1K 9A9 (Canada)]. E-mail: pierre_lafrance@inrs-ete.uquebec.ca; Villemur, Richard [Institut national de la recherche scientifique, Centre INRS-Institut Armand Frappier, Universite du Quebec, 531 bd des Prairies, Laval, Quebec, H7V 1B7 (Canada)]. E-mail: richard.villemur@inrs-iaf.uquebec.ca

    2005-11-15

    The efficacy of a new rhamnolipid biosurfactants mixture to enhance the removal of pyrene from a soil artificially contaminated was investigated. The molar solubilization ratio (MSR) and the partition coefficient between the micelles and water (log K {sub m}) were found to be 7.5 x 10{sup -3} and 5.7, respectively. From soil column studies, the pyrene removal increased linearly with the concentration of the injected biosurfactants solution above the effective critical micellar concentration (0.4 g L{sup -1}). Flushing with a 5.0 g L{sup -1} biosurfactants solution increased the pyrene concentration in the effluent by 178 times. At high biosurfactants' concentrations (2.5 and 5.0 g L{sup -1}), the cumulative pyrene recovery reached 70%. This pyrene remobilization takes place independently of the soil organic carbon solubilization. This study provides a combination of batch and column experiments in order to find the conditions for effective soil remediation using a new rhamnolipids mixture. - The potential of newly isolated biosurfactants to mobilize PAHs from contaminated soils was evaluated from the determination in dynamic conditions of their effective critical micellar concentration.

  12. Synthesis, characterization and photophysical study of ethynyl pyrene derivatives as promising materials for organic optoelectronics

    Energy Technology Data Exchange (ETDEWEB)

    Gama, Paola E.; Corrêa, Rodrigo J.; Garden, Simon J., E-mail: garden@iq.ufrj.br

    2015-05-15

    Two series of pyrene derivatives, phenylethynyl (4–6) and the previously unknown ethynylcyclohexanol (7–9), were prepared by Sonogashira cross-coupling reactions. The introduction of an increasing number of ethynyl substituents resulted in a progressive bathochromic shift in the absorption and emission spectra which culminated in an inversion of the nature of the first two excited states ({sup 1}L{sub a} and {sup 1}L{sub b}) of the tetra-substituted derivatives (6 and 9) relative to pyrene. In solution, only for the mono-cyclohexanolethynyl pyrene (7) a sufficiently concentrated solution could be obtained so as to observe the excimer. Additionally, the emission band ratio I{sub 1}/I{sub 3} for 7 was found to be moderately sensitive to the nature of the solvent and the ratio directly correlated with the Py scale. TDDFT calculations were used to explore the variation of the properties of the low lying excited states. Fluorescence emission in the solid state, with the appropriate choice of materials, covers the entire visible region of the electromagnetic spectrum due to static excimer emission. A massive red-shift for solid state photoluminescence from 9 resulted in emission at longer wavelength than the more highly conjugated 6. - Highlights: • Phenyl and cyclohexanol ethynylpyrene derivatives: photophysically compared. • Excimer formation and solvent dependent emission from cyclohexanolethynylpyrene. • Systematic red shifting of solid state photoluminescence from static excimers. • Massive red-shift in the solid state photoluminescence of 9. • TDDFT calculations: properties of the lowest singlet states, systematic comparison.

  13. Pyrene-containing peptide-based fluorescent organogels: inclusion of graphene into the organogel.

    Science.gov (United States)

    Adhikari, Bimalendu; Nanda, Jayanta; Banerjee, Arindam

    2011-10-04

    The N-terminally pyrene-conjugated oligopeptide, Py-Phe-Phe-Ala-OMe, (Py=pyrene 1-butyryl acyl) forms transparent, stable, supramolecular fluorescent organogels in various organic solvents. One of these organogels was thoroughly studied using various techniques including transmission electron microscopy (TEM), field-emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), Fourier-transform infrared (FTIR) spectroscopy, photoluminescence (PL) spectroscopy, and rheology. Unfunctionalized and non-oxidized graphene was successfully incorporated into this fluorescent organogel in o-dichlorobenzene (ODCB) to form a stable hybrid organogel. Graphene is well dispersed into the gel medium by using non-covalent π-π stacking interactions with the pyrene-conjugated gelator peptide. In the presence of graphene, the minimum gelation concentration (mgc) of the hybrid organogel was lowered significantly. This suggests that there is a favorable interaction between the graphene and the gelator peptide within the hybrid organogel system. This hybrid organogel was characterized using TEM, AFM, FTIR, PL, and rheological studies. The TEM study of graphene-containing hybrid organogel revealed the presence of both graphene sheets and entangled gel nanofibers. The AFM study indicated the presence of 3 to 4 layers in exfoliated graphene in ODCB and the presence of both graphene nanosheets and the network of gel nanofibers in the hybrid gel system. The rheological investigation suggested that the flow of the hybrid organogel had become more resistant towards the applied angular frequency upon the incorporation of graphene into the organogel. The hybrid gel is about seven times more rigid than that of the native gel.

  14. Molecular mechanics and quantum mechanical modeling of hexane soot structure and interactions with pyrene

    Directory of Open Access Journals (Sweden)

    Kubicki JD

    2000-09-01

    Full Text Available Molecular simulations (energy minimizations and molecular dynamics of an n-hexane soot model developed by Smith and co-workers (M. S. Akhter, A. R. Chughtai and D. M. Smith, Appl. Spectrosc., 1985, 39, 143; ref. 1 were performed. The MM+ (N. L. Allinger, J. Am. Chem. Soc., 1977, 395, 157; ref. 2 and COMPASS (H. Sun, J. Phys. Chem., 1998, 102, 7338; ref. 3 force fields were tested for their ability to produce realistic soot nanoparticle structure. The interaction of pyrene with the model soot was simulated. Quantum mechanical calculations on smaller soot fragments were carried out. Starting from an initial 2D structure, energy minimizations are not able to produce the observed layering within soot with either force field. Results of molecular dynamics simulations indicate that the COMPASS force field does a reasonably accurate job of reproducing observations of soot structure. Increasing the system size from a 683 to a 2732 atom soot model does not have a significant effect on predicted structures. Neither does the addition of water molecules surrounding the soot model. Pyrene fits within the soot structure without disrupting the interlayer spacing. Polycyclic aromatic hydrocarbons (PAH, such as pyrene, may strongly partition into soot and have slow desorption kinetics because the PAH-soot bonding is similar to soot–soot interactions. Diffusion of PAH into soot micropores may allow the PAH to be irreversibly adsorbed and sequestered so that they partition slowly back into an aqueous phase causing dis-equilibrium between soil organic matter and porewater.

  15. Spacial characteristics of pyrene degradation and soil microbial activity with the distance from the ryegrass (Lolium perenne L.) root surface in a multi-interlayer rhizobox.

    Science.gov (United States)

    Xie, Xiaomei; Liao, Min; Fang, Shu; Peng, Ying; Yang, Jing; Chai, Juanjuan

    2012-04-30

    To investigate rhizosphere effects on the biodegradation of pyrene with the distance away from root surface in the rhizosphere of ryegrass (Lolium perenne L.), a glasshouse experiment was conducted using a multi-interlayer rhizobox where ryegrass were grown in a soil spiked with pyrene. The largest and most rapid dissipation of pyrene in planted soil appeared at 2 mm zone from the root zone. The pyrene degradation gradient followed the order: near-rhizosphere>root compartment>far-rhizosphere soil zones. In contrast, there was no difference in pyrene concentration with distance in the unplanted soil. Dynamic changes of soil microbial biomass carbon (C(mic)) and the activities of both soil polyphenol oxidase and dehydrogenase were to some extent coincident with the degradation of pyrene with distance away from the root compartment in planted soils, which indicated the changes of soil microorganisms in different soil zones of rhizosphere were mainly responsible for the observed pyrene degradation. The largest C(mic) and activities of both soil polyphenol oxidase and dehydrogenase also occurred in near-rhizosphere, especially in 2mm zone from the root surface. The above results suggest that the effect of root proximity is important in the degradation of pyrene in ryegrass growing soil.

  16. Metabolism of pyrene by the basidiomycete crinipellis stipitaria and identification of pyrenequinones and their hydroxylated precursors in strain JK375

    Energy Technology Data Exchange (ETDEWEB)

    Lambert, M.; Kremer, S.; Anke, H.; Sterner, O. (Univ. of Lund (Sweden))

    1994-10-01

    The metabolism of pyrene, a polycyclic aromatic hydrocarbon, by submerged cultures of the basidiomycete Crinipellis stipitaria was studied. After incubation for 68 h at 25[degrees]C in a 20-liter fermentor with complex medium and 20 mg of pyrene per liter, five metabolites were detected. The compounds were isolated by preparative high-performance liquid chromatography on RP18 and DIOL gels. By, UV, infrared, and [sup 1]H nuclear magnetic resonance spectroscopy and mass spectrometry, 1-hydroxypyrene, 1,6-dihydroxypyrene, 1,8-dihydroxypyrene, 1,6-pyrenequinone, and 1,8-pyrenequinone were identified 1,6- and 1,8-dihydroxypyrene were obtained from fungal cultures for the first time. The formation of these metabolites was confirmed by investigations with [4,5,9,10-[sup 14]C]pyrene. 29 refs., 2 figs., 2 tabs.

  17. Synthesis, physical properties and self-assembly behavior of azole-fused pyrene derivatives

    Science.gov (United States)

    Xiao, Jinchong; Xiao, Xuyu; Zhao, Yanlei; Wu, Bo; Liu, Zhenying; Zhang, Xuemin; Wang, Sujuan; Zhao, Xiaohui; Liu, Lei; Jiang, Li

    2013-05-01

    A novel selenadiazole-fused pyrene derivative PySe was successfully synthesized and characterized. Its single structure is almost planar and adopts a sandwich-herringbone packing model. The self-assembly behaviors based on compound PySe and its analogue thiadiazole-fused pyrene derivative PyS were studied in detail and the as-formed nanostructures were fully characterized by means of UV-vis absorption, emission spectra, X-ray diffraction, field emission SEM and TEM. We attribute the bathochromic shift absorption and emission spectra of PyS and PySe in aqueous solution to the formation of J-type aggregation. In addition, our investigation demonstrated that the shape and size of the as-prepared nanostructures could be tuned by different chalcogen analogues and the volume ratio of water to organic solvent.A novel selenadiazole-fused pyrene derivative PySe was successfully synthesized and characterized. Its single structure is almost planar and adopts a sandwich-herringbone packing model. The self-assembly behaviors based on compound PySe and its analogue thiadiazole-fused pyrene derivative PyS were studied in detail and the as-formed nanostructures were fully characterized by means of UV-vis absorption, emission spectra, X-ray diffraction, field emission SEM and TEM. We attribute the bathochromic shift absorption and emission spectra of PyS and PySe in aqueous solution to the formation of J-type aggregation. In addition, our investigation demonstrated that the shape and size of the as-prepared nanostructures could be tuned by different chalcogen analogues and the volume ratio of water to organic solvent. Electronic supplementary information (ESI) available: TGA analysis, spectra characterization data for compound 1, 2, 3 and X-ray crystallographic data for compound PySe (2, CIF). CCDC 917821. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c3nr00523b

  18. UV irradiation induced switching of surface charge polarity on pyrene modified Si nanowires

    Science.gov (United States)

    Zhao, Wen-Chao; Wang, Hui; Ou, Xue-Mei; Lee, Chun-Sing; Zhang, Xiao-Hong

    2011-06-01

    It has been widely recognized that surface charge in nanomaterials can significantly affect their electrical properties. In this letter, we demonstrate that polarity of surface charge on pyrene modified silicon nanowires (SiNWs) can be switched by illumination of UV light. Unlike the reported conversion method via changing the surrounding pH value, switching process reported here takes place in real-time and does not require introduction of any other chemical species. Mechanisms of the surface charge polarity switching and potential applications of such systems were discussed.

  19. Steady state and time-resolved fluorimetry of benzo( a)pyrene in liposomes and microsomes

    Science.gov (United States)

    Li, K. P.; Glick, M. R.; Indralingam, R.; Winefordner, J. D.

    1989-01-01

    Comparisons of the steady-state fluorescence signals of benzo( a)pyrene (BP) in liposomes and in microsomes indicate that BP molecules involved in the formation of excimers emitting around 520 nm may be the primary species being oxidized during the first 30 min of metabolism. Moreover, these excimers seem to be kinetically differentiable from BP molecules in other locations in the membrane. Since excimers can be formed only when BP molecules are close together, this implies that the metabolizing BP molecules are more likely on the membrane surface than in the midplane region.

  20. Determination of the level of benzo[a]pyrene in fatty foods and food supplements

    OpenAIRE

    Van Der Wielen-Hustinx, Jacqueline Claire Agnes; Jansen, John; Martena, Martijn J.; De Groot, Henk; In T Veld, Paul

    2006-01-01

    Abstract A routine method was developed for the quantification of benzo[a]pyrene (BaP) in edible oils and food supplements. BaP is often taken as an indicator of the presence of polycyclic aromatic hydrocarbons. The method consists of on-line LC-clean up followed by injection to an HPLC-system connected with fluorescence detection. The method has good performance characteristics and gave good results in proficiency tests. From 2002 to 2004 about 1350 samples, oils and food supp...

  1. Mikrobieller Abbau von 14 C-markiertem Benzo[a]pyren durch PAK-adaptierte Bakterienmischkulturen

    OpenAIRE

    Schwiening, Susanne

    2000-01-01

    In the last years the biodegradation of polycylic aromatic hydrocarbons (PAH) for the bioremediation of polluted soils was studied. Important for a successfull remediation is the degradation of the high molecular weight PAH, a major class of carcinogenic and persistent organic compounds. So the aim of this work was to study the biodegradation of the 5-ring benzo[a]pyrene (BaP) as a priority pollutant of the high molecular weight PAH. With the use of 14C labeled BaP the degradation could be qu...

  2. Novel (Phenylethynyl)pyrene-LNA Constructs for Fluorescence SNP Sensing in Polymorphic Nucleic Acid Targets

    DEFF Research Database (Denmark)

    Astakhova, Irina Kira; Samokhina, Evgeniya; Babu, B Ravindra;

    2012-01-01

    We describe fluorescent oligonucleotide probes labeled with novel (phenylethynyl)pyrene dyes attached to locked nucleic acids. Furthermore, we prove the utility of these probes for the effective detection of single-nucleotide polymorphisms in natural nucleic acids. High-affinity hybridization...... of the probes and excellent fluorescence responses to single-base mismatches in DNA/RNA targets are demonstrated in model dual-probe and doubly labeled probe formats. This stimulated us to develop two diagnostic systems for the homogeneous detection of a drug-resistance-causing mutation in HIV-1 protease c...

  3. Pyrene-Based Small Molecular Nonlinear Optical Materials Modified by ``Click-Reaction''

    Science.gov (United States)

    Liang, Pengxia; Li, Zhengqiang; Mi, Yongsheng; Yang, Zhou; Wang, Dong; Cao, Hui; He, Wanli; Yang, Huai

    2015-08-01

    Two pyrene derivatives were successfully synthesized via an efficient copper(I)-catalyzed azide alkyne 1,3-dipolar cycloaddition. The photophysical and electrochemical properties were characterized using ultraviolet-visible absorption spectra, fluorescence spectra, cyclic voltammograms and density functional theory modulations. These results showed that the symmetry structure of these derivatives formed an electron-delocalized organic system, which have larger effects in achieving a third-order nonlinear optical (NLO) response. The third-order nonlinear properties including the nonlinear absorption and the nonlinear susceptibilities investigated by Z-scan technique indicate that the title compounds can serve as a promising candidate for third-order NLO applications.

  4. Effect of Co-Existing Biologically Relevant Molecules and Ions on DNA Photocleavage Caused by Pyrene and its Derivatives

    Directory of Open Access Journals (Sweden)

    Hongtao Yu

    2005-04-01

    Full Text Available Inorganic ions, coenzymes, amino acids, and saccharides could co-exist with toxic environmental chemicals, such as polycyclic aromatic hydrocarbons (PAHs, in the cell. The presence of these co-existing chemicals can modulate the toxicity of the PAHs. One of the genotoxic effects by PAHs is light-induced cleavage, or photocleavage, of DNA. The effect of inorganic ions I-, Na+, Ca2+, Mg2+, Fe3+, Mn2+, Cu2+, and Zn2+ and biological molecules riboflavin, histidine, mannitol, nicotinamide adenine dinucleotide (NAD, glutathione, and glutamic acid on the DNA photocleavage by pyrene, 1-hydroxypyrene (1-HP, and 1-aminopyrene (1-AP, is studied. The non-transition metal ions Na+, Ca2+, and Mg2+, usually have very little inhibitory effects, while the transition metal ions Fe3+, Cu2+, and Zn2+ enhance, Mn2+ inhibits the DNA photocleavage. The effect by biological molecules is complex, depending on the photochemical reaction mechanisms of the compounds tested (1-AP, 1-HP and pyrene and on the chemical nature of the added biological molecules. Riboflavin, histidine, and mannitol enhance DNA photocleavage by all three compounds, except that mannitol has no effect on the photocleavage of DNA by pyrene. Glutathione inhibits the DNA photocleavage by 1-AP and 1-HP, but has no effect on that by pyrene. NAD enhances the DNA photocleavage by 1-AP, but has no effect on that by 1-HP and pyrene. Glutamic acid enhances the DNA photocleavage by 1-AP and pyrene, but inhibits that by 1-HP. These results show that the co-existing chemicals may have a profound effect on the toxicity of PAHs, or possibly on the toxicity of many other chemicals. Therefore, if one studies the toxic effects of PAHs or other toxic chemicals, the effect of the co-existing chemicals or ions needs to be considered.

  5. Enhanced-electrokinetic remediation of copper-pyrene co-contaminated soil with different oxidants and pH control.

    Science.gov (United States)

    Cang, Long; Fan, Guang-Ping; Zhou, Dong-Mei; Wang, Quan-Ying

    2013-02-01

    Electrokinetic (EK) remediation has potential to simultaneously remove heavy metals and organic compounds from soil, but the removal percent of these pollutants is very low in general if no enhancing treatment is applied. This study developed a new enhanced-EK remediation technology to decontaminate a heavy metal-organic compound co-contaminated soil by applying different oxidants and pH control. A red soil was used as a model clayed soil, and was spiked with pyrene and Cu at about 500 mg kg(-1) for both to simulate real situation. Bench-scale EK experiments were performed using four oxidants (H(2)O(2), NaClO, KMnO(4), and Na(2)S(2)O(8)) and controlling electrolyte pH at 3.5 or 10. After the treatments with 1.0 V cm(-1) of voltage gradient for 335 h, soil pH, electrical conductivity, and the concentrations and chemical fractionations of soil pyrene and Cu were analyzed. The results showed that there was significant migration of pyrene and Cu from the soil, and the removal percent of soil pyrene and Cu varied in the range of 30-52% and 8-94%, respectively. Low pH favoured the migration of soil Cu, while KMnO(4) was the best one for the degradation of pyrene among the tested oxidants, although it unfortunately prevented the migration of soil Cu by forming Cu oxide. Application of Na(2)S(2)O(8) and to control the catholyte pH at 3.5 were found to be the best operation conditions for decontaminating the Cu-pyrene co-contaminated soil.

  6. Impact of bioaccessible pyrene on the abundance of antibiotic resistance genes during Sphingobium sp.- and sophorolipid-enhanced bioremediation in soil.

    Science.gov (United States)

    Sun, Mingming; Ye, Mao; Wu, Jun; Feng, Yanfang; Shen, Fangyuan; Tian, Da; Liu, Kuan; Hu, Feng; Li, Huixin; Jiang, Xin; Yang, Linzhang; Kengara, Fredrick Orori

    2015-12-30

    Soils are exposed to various types of chemical contaminants due to anthropogenic activities; however, research on persistent organic pollutants and the existence of antibiotic resistance genes (ARGs) is limited. To our knowledge, the present work for the first time focused on the bioremediation of soil co-contaminated with pyrene and tetracycline/sulfonamide-resistance genes. After 90 days of incubation, the pyrene concentration and the abundance of the four ARGs (tetW, tetM, sulI, and sulII) significantly decreased in different treatment conditions (psoil treated with sophorolipid alone. Tenax extraction methods and linear correlation analysis indicated a strong positive relationship between the rapidly desorbing fraction (Fr) of pyrene and ARG abundance. Therefore, we conclude that bioaccessible pyrene rather than total pyrene plays a major role in the maintenance and fluctuation of ARG abundance in the soil.

  7. Electrochemical detection of benzo(a)pyrene and related DNA damage using DNA/hemin/nafion–graphene biosensor

    Energy Technology Data Exchange (ETDEWEB)

    Ni, Yongnian, E-mail: ynni@ncu.edu.cn [State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047 (China); Department of Chemistry, Nanchang University, Nanchang 330031 (China); Wang, Pingping; Song, Haiyan [Department of Chemistry, Nanchang University, Nanchang 330031 (China); Lin, Xiaoyun [State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047 (China); Department of Chemistry, Nanchang University, Nanchang 330031 (China); Kokot, Serge, E-mail: s.kokot@qut.edu.au [School of Chemistry, Physics and Mechanical Engineering, Science and Engineering Faculty, Queensland University of Technology, Brisbane 4001 (Australia)

    2014-04-01

    Graphical abstract: A novel electrochemical biosensor, DNA/hemin/nafion–graphene/GCE, was constructed to quantitatively study the DNA damage induced by the metabolite of benzo(a)pyrene in the presence of H{sub 2}O{sub 2}. - Highlights: • Construction of a novel DNA/hemin/nafion-graphene/GCE biosensor. • DNA damage induced by the benzo(a)pyrene metabolite was detected. • DPV analysis of benzo(a)pyrene provided a quantitative estimate of DNA damage. • Hemin/H{sub 2}O{sub 2} system could mimic the cytochrome P450 to metabolize benzo(a)pyrene. - Abstract: A novel electrochemical biosensor, DNA/hemin/nafion–graphene/GCE, was constructed for the analysis of the benzo(a)pyrene PAH, which can produce DNA damage induced by a benzo(a)pyrene (BaP) enzyme-catalytic product. This biosensor was assembled layer-by-layer, and was characterized with the use of cyclic voltammetry, electrochemical impedance spectroscopy (EIS) and atomic force microscopy. Ultimately, it was demonstrated that the hemin/nafion–graphene/GCE was a viable platform for the immobilization of DNA. This DNA biosensor was treated separately in benzo(a)pyrene, hydrogen peroxide (H{sub 2}O{sub 2}) and in their mixture, respectively, and differential pulse voltammetry (DPV) analysis showed that an oxidation peak was apparent after the electrode was immersed in H{sub 2}O{sub 2}. Such experiments indicated that in the presence of H{sub 2}O{sub 2}, hemin could mimic cytochrome P450 to metabolize benzo(a)pyrene, and a voltammogram of its metabolite was recorded. The DNA damage induced by this metabolite was also detected by electrochemical impedance and ultraviolet spectroscopy. Finally, a novel, indirect DPV analytical method for BaP in aqueous solution was developed based on the linear metabolite versus BaP concentration plot; this method provided a new, indirect, quantitative estimate of DNA damage.

  8. Fate and distribution of pyrene in Ilyanassa obsoleta exposed through the diet

    Directory of Open Access Journals (Sweden)

    S Erskine

    2010-02-01

    Full Text Available The ability of Eastern mud snails to bioaccumulate and biotransform a model polycyclic aromatic hydrocarbon (PAH, pyrene (PY, was investigated. The contaminant was added to fish at levels ranging from 2 to 5,000 ng/animal fed 20 mg/each and fed to snails. A linear relationship (p=0.03 was observed between the level of PY and the sum of metabolites consisting predominantly of 1-hydroxypyrene and pyrene-1-sulfate detected in soft tissues of snails. In healthy animals, more PY than metabolites was detected, with more biotransformation relative to the parent compound apparent at lower levels of exposure. In ten snails fed together, the body burden of PY-related compounds displayed 49% variability as well as a similar mean and median. One snail within that group had five times more metabolites than PY and was retracted inside the shell, indicating that the animal was stressed. Radio-labelled PY was detected in the largest proportion in the kidney of the animals. Three snails that died during the exposure had also greater than five times more PY metabolites relative to live counterparts. This study is unique in the links that it establishes between stress and the balance of fates of anthropogenic chemicals in biota

  9. Isolation of marine benzo[a]pyrene-degrading Ochrobactrum sp. BAP5 and proteins characterization

    Institute of Scientific and Technical Information of China (English)

    WU Yirui; HE Tengteng; ZHONG Mingqi; ZHANG Yueling; LI Enmin; HUANG Tongwang; HU Zhong

    2009-01-01

    A bacterial strain BAP5 with a relatively high degradation ability of benzo[a]pyrene (BaP) was isolated from marine sediments of Xiamen Western Sea, China and identified as Ochrobactrum sp. according to 16S rRNA gene sequence as well as biolog microbial identification system. Strain BAP5 could grow in mineral salt medium with 50 mg/L of BaP and degrade about 20% BaP after 30 d of incubation. Ochrobactrum sp. BAP5 was able to utilize other polycyclic aromatic hydrocarbons (PAHs) (such as phenanthrene, pyrene and fluoranthene) as the sole carbon source and energy source, suggesting its potential application in PAHs bioremediation. The profile of total soluble protein from Ochrobactrum sp. BAP5 was also investigated. Some over- and special-expressed proteins of strain BAP5 when incubated with the presence of BaP were detected by using two-dimensional polyacrylamide gel electrophoresis, and found to be related with PAHs metabolism, DNA translation, and energy production based on peptide fingerprint analysis through matrix-assisted laser desorption/ionization-time of flight mass spectrometry.

  10. Potential application of synchronous fluorescence spectroscopy to determine benzo[a]pyrene in soil extracts

    Energy Technology Data Exchange (ETDEWEB)

    Hua Guoxiong [School of Biology, Institute for Research on the Environment and Sustainability, Devonshire Building, University of Newcastle upon Tyne, NE1 7RU (United Kingdom); Killham, Ken [Department of Plant and Soil Science, Cruickshank Building, University of Aberdeen, AB24 3UU (United Kingdom); Singleton, Ian [School of Biology, Institute for Research on the Environment and Sustainability, Devonshire Building, University of Newcastle upon Tyne, NE1 7RU (United Kingdom)]. E-mail: ian.singleton@ncl.ac.uk

    2006-01-15

    Benzo[a]pyrene (BaP) is a significant environmental pollutant and rapid, accurate methods to quantify this compound in soil for both research and environmental investigation purposes are required. In this work, solvent extracts from five contrasting soils spiked with four different polycyclic aromatic hydrocarbons (PAHs) were rapidly analysed by using a synchronous fluorescence spectroscopy (SFS) method. The SFS method was validated using HPLC with ultraviolet detection. A good correlation for the quantification of BaP in soil extracts by the two methods was observed. The detection limit of the SFS method was 1.6 x 10{sup -9} g/ml in CTAB micellar medium (7.8 mmol/l). The work demonstrates that SFS has potential as a sensitive, accurate, rapid, simple and economic methodology and an efficient alternative to HPLC for fast confirmation and quantification of BaP in complex soil extracts. - Synchronous fluorescence spectroscopy has potential as a method for confirmation of benzo[a]pyrene in soil extracts.

  11. Targeting Antibodies to Carbon Nanotube Field Effect Transistors by Pyrene Hydrazide Modification of Heavy Chain Carbohydrates

    Directory of Open Access Journals (Sweden)

    Steingrimur Stefansson

    2012-01-01

    Full Text Available Many carbon nanotube field-effect transistor (CNT-FET studies have used immobilized antibodies as the ligand binding moiety. However, antibodies are not optimal for CNT-FET detection due to their large size and charge. Their size can prevent ligands from reaching within the Debye length of the CNTs and a layer of charged antibodies on the circuits can drown out any ligand signal. In an attempt to minimize the antibody footprint on CNT-FETs, we examined whether pyrene hydrazide modification of antibody carbohydrates could reduce the concentration required to functionalize CNT circuits. The carbohydrates are almost exclusively on the antibody Fc region and this site-specific modification could mediate uniform antibody orientation on the CNTs. We compared the hydrazide modification of anti-E. coli O157:H7 polyclonal antibodies to pyrenebutanoic acid succinimidyl ester-coated CNTs and carbodiimide-mediated antibody CNT attachment. Our results show that the pyrene hydrazide modification was superior to those methods with respect to bacteria detection and less than 1 nM labeled antibody was required to functionalize the circuits.

  12. Simultaneous biodegradation of creosote-polycyclic aromatic hydrocarbons by a pyrene-degrading Mycobacterium

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, Z.; Vila, J.; Grifoll, M. [Barcelona Univ. (Spain). Dept. de Microbiologia; Ortega-Calvo, J.J. [C.S.I.C., Seville (Spain). Inst. de Recursos Naturales y Agrobiologia

    2008-02-15

    When incubated with a creosote-polycyclic aromatic hydrocarbons (PAHs) mixture, the pyrene-degrading strain Mycobacterium sp. AP1 acted on three- and four-ring components, causing the simultaneous depletion of 25% of the total PAHs in 30 days. The kinetics of disappearance of individual PAHs was consistent with differences in aqueous solubility. During the incubation, a number of acid metabolites indicative of distinctive reactions carried out by high-molecular-weight PAH-degrading mycobacteria accumulated in the medium. Most of these metabolites were dicarboxylic aromatic acids formed as a result of the utilization of growth substrates (phenanthrene, pyrene, or fluoranthene) by multibranched pathways including meta- and ortho-ring-cleavage reactions: phthalic acid, naphthalene-1,8-dicarboxylic acid, phenanthrene-4,5-dicarboxylic acid, diphenic acid, Z-9-carboxymethylenefluorene-1-carboxylic acid, and 6,6'-dihydroxy-2,2'-biphenyl dicarboxylic acid. Others were dead-end products resulting from cometabolic oxidations on nongrowth substrates (fluorene meta-cleavage product). These results contribute to the general knowledge of the biochemical processes that determine the fate of the individual components of PAH mixtures in polluted soils. The identification of the partially oxidized compounds will facilitate to develop analytical methods to determine their potential formation and accumulation in contaminated sites. (orig.)

  13. Remediation of benzo[a]pyrene and chrysene-contaminated soil with industrial hemp (Cannabis sativa).

    Science.gov (United States)

    Campbell, Sonia; Paquin, Daniel; Awaya, Jonathan D; Li, Qing X

    2002-01-01

    The phytoremediation, with industrial hemp (Cannabis sativa), of a Hawaiian silty clay soil contaminated with two polycyclic aromatic hydrocarbons (PAHs), chrysene and benzo[a]pyrene, was studied. Hemp showed a very high tolerance to the contaminants. The growth rates of hemp, compared with control, in soils fortified with chrysene and benzo[a]pyrene at concentrations of each varying from 25 to 200 micrograms/g were consistently above 100%. The plants grew from seed for 45 days in soil fortified with PAHs at concentrations of 25, 50, and 75 micrograms/g. Controls were pots with contaminated soil but no plant. PAHs levels were significantly reduced in all pots (control and seeded pots), expect for one set at a high concentration of chrysene, which may be due to uneven spiking. A time course study over 28 days was done to monitor changes of microbial count and levels of chrysene. Little changes were observed for the total microbial count in the soil, and the concentration of chrysene in the soil decreased slightly in the pots containing plants. However, the chrysene levels in those pots were consistently lower than those in the pots without plants.

  14. Molecular modelling of cytochrome CYP1A1: a putative access channel explains differences in induction potency between the isomers benzo(a)pyrene and benzo(e)pyrene, and 2- and 4-acetylaminofluorene.

    Science.gov (United States)

    Lewis, D F; Ioannides, C; Parke, D V

    1994-05-01

    The present studies were undertaken to provide a rationale for the observation that benzo(a)pyrene and 2-acetylaminofluorene induce the hepatic CYP1A1 protein, whereas their non-carcinogenic isomers benzo(e)pyrene and 4-acetylaminofluorene are, at best, relatively very weak inducers. Using amino acid sequence alignment, a molecular model of the CYP1A1 was constructed by analogy to CYP101, the bacterial protein for which the 3-dimensional structure is known from X-ray crystallographic analysis. The putative structure of the active site of the CYP1A1 protein shows the presence of two phenylalanine residues preferentially aligned in parallel orientation, presumably functioning as a 'sieve' for planar molecules, the established substrates of CYP1A1. The molecular dimensions of this putative access channel show a width and depth of 8.321 and 3.261 A, respectively. The width of 4-acetylaminofluorene, 8.794 A, and benzo(e)pyrene, 9.153 A, precludes their passage through this channel access in contrast to benzo(a)pyrene and 2-acetylaminofluorene having a width of 7.150 and 5.283 A, respectively, explaining their difference in CYP1A1 induction potential.

  15. Simple efficient synthesis of strongly luminescent polypyrene with intrinsic conductivity and high carbon yield by chemical oxidative polymerization of pyrene.

    Science.gov (United States)

    Li, Xin-Gui; Liu, You-Wei; Huang, Mei-Rong; Peng, Sai; Gong, Ling-Zhi; Moloney, Mark G

    2010-04-26

    A wholly aromatic polypyrene was synthesized by direct chemical oxidative polymerization of pyrene with ferric chloride as oxidant in hexane/nitromethane. Successful synthesis of polypyrene was thoroughly confirmed by IR, UV/Vis, 1D (1)H NMR, 2D (1)H-(1)H COSY, 2D (1)H-(13)C HSQC, MALDI-TOF MS, elemental analysis, and X-ray diffraction methods. The results indicated that the polypyrene was formed mainly through dehydro coupling between 2- or 1- and 2'- or 1'-positions on pyrene rings having a degree of polymerization of around 24. The polypyrene was purified and then separated into THF-soluble (ca. 10 %) and THF-insoluble (ca. 90 %) fractions. Compared with insulating pyrene monomer, the polypyrene is a controllably conducting polymer that has low conductivity of 3.4x10(-8) S cm(-1) in its virgin state, moderate conductivity of 2.28x10(-4) S cm(-1) upon iodine doping, but much higher conductivity of up to 81.2 S cm(-1) after the insoluble polypyrene was heated up to 1300 degrees C in nitrogen with a high char yield of 70.6 %. In particular, the soluble polypyrene demonstrates much stronger visible color fluorescence and much lower toxicity than pyrene. The soluble polypyrene would be advantageous for detecting Fe(3+) with almost no interference of other metal ions. The soluble and insoluble polypyrene fractions have potential applications as intrinsically luminescent and highly conducting carbon materials, respectively.

  16. Metabolism of (/sup 3/H)benzo(a)pyrene by cultured human bronchus and cultured human pulmonary alveolar macrophages

    DEFF Research Database (Denmark)

    1978-01-01

    The metabolism of (/sup 3/H)benzo(a)pyrene by cultured human bronchial epithelium and pulmonary alveolar macrophages was studied. Explants of bronchus were prepared and pulmonary alveolar macrophages were isolated from peripheral lung by trypsinization and by differential adhesion to plastic tissue...

  17. Species-specific testicular and hepatic microsomal metabolism of benzo(a)pyrene, an ubiquitous toxicant and endocrine disruptor

    Science.gov (United States)

    Information on the metabolism of the environmental toxicant, benzo(a)pyrene (BaP) in the male reproductive system is crucial for understanding BaP-induced infertility. Microsomes were isolated from the liver and testes of rat, mouse, hamster, ram, boar, bull, and monkey and incubated with BaP. Post-...

  18. Förster resonance energy transfer between pyrene and bovine serum albumin: Effect of the hydrophobic pockets of cyclodextrins

    Science.gov (United States)

    Maity, Arnab; Mukherjee, Puspal; Das, Tarasankar; Ghosh, Prasun; Purkayastha, Pradipta

    The phenomenon of Förster resonance energy transfer (FRET) between pyrene and bovine serum albumin (BSA) protein in presence of cyclodextrins (CDs) is explored in the present work. CDs provide hydrophobic environment and thus the aromatic molecules get encapsulated in them depending on the relative size and space. In this work we revealed that along with pyrene monomer, the side chains of amino acids in BSA can get trapped partly in the hydrophobic cavities of CDs if space permits. While being encapsulated by β-CD as pyrene monomer, it can interact with the BSA tryptophan moiety exposed toward the aqueous environment to form a dimer through π-π interaction. This, in turn, affects the energy transfer process by reducing the efficiency. On the other hand, pyrene excimer gets encapsulated in a γ-CD molecule due to availability of enough space. The excimer shows a new band at a higher wavelength. This further reduces FRET efficiency due to scarcity of acceptor for the tryptophan moieties in BSA.

  19. Branched DNA nanostructures efficiently stabilised and monitored by novel pyrene-perylene 2'-α-l-amino-LNA FRET pairs

    DEFF Research Database (Denmark)

    Astakhova, I Kira; Santhosh Kumar, T; Campbell, Meghan A;

    2013-01-01

    Novel pyrene-perylene α-l-LNA FRET pairs described herein effectively detect assembly of 2- and 3-way branched DNA nanostructures prepared by postsynthetic microwave-assisted CuAAC click chemistry. The fluorescent signalling of assembly by internally positioned FRET pairs is achieved with low to ...

  20. Fluorobenzo[a]pyrenes as probes of the mechanism of cytochrome P450-catalyzed oxygen transfer in aromatic oxygenations

    NARCIS (Netherlands)

    Mulder, P.P.J.; Devanesan, P.; Alem, van K.; Lodder, G.; Rogan, E.G.; Cavalieri, E.L.

    2003-01-01

    Fluoro substitution of benzo[a]pyrene (BP) has been very useful in determining the mechanism of cytochrome P450-catalyzed oxygen transfer in the formation of 6-hydroxyBP (6-OHBP) and its resulting BP 1,6-, 3,6-, and 6,12-diones. We report here the metabolism of 1-FBP and 3-FBP, and PM3 calculations

  1. Combined exposure to pyrene and fluoranthene and their molecular effects on the Sydney rock oyster, Saccostrea glomerata.

    Science.gov (United States)

    Ertl, Nicole G; O'Connor, Wayne A; Brooks, Peter; Keats, Michael; Elizur, Abigail

    2016-08-01

    Polycyclic aromatic hydrocarbons (PAHs) are ubiquitously detected in the water column, associated with particulate matter or in the tissue of marine organisms such as molluscs. PAH exposure and their resultant bioaccumulation in molluscs can cause a range of serious physiological effects in the affected animals. To examine the molecular response of these xenobiotics in bivalves, Sydney rock oysters (Saccostrea glomerata) were exposed to pyrene and fluoranthene for seven days. Chemical analysis of the soft-tissue of PAH stressed S. glomerata confirmed that pyrene and fluoranthene could be bioaccumulated by these oysters. RNA-Seq analysis of PAH-exposed S. glomerata showed a total of 765 transcripts differentially expressed between control and PAH-stressed oysters. Closer examination of the transcripts revealed a range genes encoding enzymes involved in PAH detoxification (e.g. cytochrome P450), innate immune responses (e.g. pathogen recognition, phagocytosis) and protein synthesis. Overall, pyrene and fluoranthene exposure appears to have resulted in a suppression of pathogen recognition and some protein synthesis processes, whereas transcripts of genes encoding proteins involved in clearance of cell debris and some transcripts of genes involved in PAH detoxification were induced in response to the stressors. Pyrene and fluoranthene exposure thus invoked a complex molecular response in S. glomerata, with results suggesting that oysters focus on removing the stressors from their system and dealing with the downstream effects of PAH exposure, potentially at the exclusion of other, less immediate concerns (e.g. protection from infection).

  2. Labeling-free fluorescent detection of DNA hybridization through FRET from pyrene excimer to DNA intercalator SYBR green I.

    Science.gov (United States)

    Zhou, Ruyi; Xu, Chen; Dong, Jie; Wang, Guojie

    2015-03-15

    A novel labeling-free fluorescence complex probe has been developed for DNA hybridization detection based on fluorescence resonance energy transfer (FRET) mechanism from pyrene excimer of pyrene-functionalized poly [2-(N, N-dimethylamino) ethyl methacrylate] (PFP) to SYBR Green I (SG, a specific intercalator of double-stranded DNA) in a cost-effective, rapid and simple manner. The complex probe consists of the positively charged PFP, SG and negatively charged single-stranded DNA (ssDNA). Upon adding a complementary strand to the complex probe solution, double-stranded DNA (dsDNA) was formed, followed by the intercalation of SG into dsDNA. The pyrene excimer emission was overlapped with the absorption of SG very well and the electrostatic interactions between PFP and dsDNA kept them in close proximity, enabling efficient FRET from pyrene excimer to SG. The fluorescence of SG in the duplex DNA resulting from FRET can be successfully applied to detect DNA hybridization with high sensitivity for a very low detection limit of 10nM and excellent selectivity for detection of single base pair mismatch. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Effects on specific promoter DNA methylation in zebrafish embryos and larvae following benzo[a]pyrene exposure

    Science.gov (United States)

    Benzo[a]pyrene (BaP) is an established reproductive and developmental toxicant. BaP exposure in humans and animals has been linked to infertility and multigenerational health consequences. DNA methylation is the most studied epigenetic mechanism that regulates gene expression, and mapping of methyla...

  4. Benzo[a]pyrene co-metabolism in the presence of plant root extracts and exudates: Implications for phytoremediation

    Energy Technology Data Exchange (ETDEWEB)

    Rentz, Jeremy A. [Civil and Environmental Engineering, University of Iowa, Iowa City, IA 52242 (United States); Alvarez, Pedro J.J. [Civil and Environmental Engineering, Rice University, Houston, TX 77251 (United States); Schnoor, Jerald L. [Civil and Environmental Engineering, University of Iowa, Iowa City, IA 52242 (United States)]. E-mail: jerald-schnoor@uiowa.edu

    2005-08-15

    Benzo[a]pyrene, a high molecular weight (HMW) polycyclic aromatic hydrocarbon (PAH) was removed from solution by Sphingomonas yanoikuyae JAR02 while growing on root products as a primary carbon and energy source. Plant root extracts of osage orange (Maclura pomifera), hybrid willow (Salix albaxmatsudana), or kou (Cordia subcordata), or plant root exudates of white mulberry (Morus alba) supported 15-20% benzo[a]pyrene removal over 24 h that was similar to a succinate grown culture and an unfed acetonitrile control. No differences were observed between the different root products tested. Mineralization of {sup 14}C-7-benzo[a]pyrene by S. yanoikuyae JAR02 yielded 0.2 to 0.3% {sup 14}CO{sub 2} when grown with plant root products. Collectively, these observations were consistent with field observations of enhanced phytoremediation of HMW PAH and corroborated the hypothesis that co-metabolism may be a plant/microbe interaction important to rhizoremediation. However, degradation and mineralization was much less for root product-exposed cultures than salicylate-induced cultures, and suggested the rhizosphere may not be an optimal environment for HMW PAH degradation by Sphingomonas yanoikuyae JAR02. - Bacterial benzo[a]pyrene cometabolism, a plant-microbe interaction affecting polycyclic aromatic hydrocarbon phytoremediation was demonstrated with Sphingomonas yanoikuyae JAR02 that utilized plant root extracts and exudates as primary substrates.

  5. USE OF MULTIPHOTON LASER SCANNING MICROSCOPY TO IMAGE BENZO[A]PYRENE AND METABOLITES IN FISH EGGS

    Science.gov (United States)

    Multiphoton laser scanning microscopy (MPLSM) is a promising tool to study the tissue distribution of environmental chemical contaminants during fish early life stages. One such chemical for which this is possible is benzo[a]pyrene (BaP), a polycyclic aromatic hydrocarbon that a...

  6. USE OF MULTIPHOTON LASER SCANNING MICROSCOPY TO IMAGE BENZO[A]PYRENE AND METABOLITES IN FISH EARLY LIFE STAGES

    Science.gov (United States)

    Multiphoton laser scanning micrsocopy holds promise as a tool to study the tissue distribution of environmental chemical contaminants during fish early life stage development. One such chemical for which this is possible is benzo[a]pyrene (BaP), a polyaromatic hydrocarbon that a...

  7. Triggering Gel Formation and Luminescence through Donor-Acceptor Interactions in a C3 -Symmetric Tris(pyrene) System.

    Science.gov (United States)

    Lai, Thanh-Loan; Pop, Flavia; Melan, Caroline; Canevet, David; Sallé, Marc; Avarvari, Narcis

    2016-04-18

    Straightforward modulation of the gelation, absorption and luminescent properties of a tris(pyrene) organogelator containing a C3 -symmetric benzene-1,3,5-tricarboxamide central unit functionalized by three 3,3'-diamino-2,2'-bipyridine fragments is achieved through donor-acceptor interactions in the presence of tetracyanoquinodimethane.

  8. EFFECT OF GLYCYRRHETINIC ACID ON DNA DAMAGE AND UNSCHEDULED DNA SYNTHESIS INDUCED BY BENZO (α) PYRENE

    Institute of Scientific and Technical Information of China (English)

    陈晓光; 韩锐

    1995-01-01

    Glycyrrhetinic acid (GA) is an active component of Glycyrrhiza uraleusis fisch. In this study, GA was found to inhibit ear edema and ornithine decarboxykase (ODC)activity induced by croton oil in mice. GA could also protect rapid DNA damage and decrease the unscheduled DNA synthesis induced by benzo(α)pyrene, The results demonstrate that GA has a potential cancer chemopreventive activity.

  9. Influence of diet and ration level on benzo[a]pyrene metabolism and excretion in rainbow trout (Oncorhynchus mykiss).

    Science.gov (United States)

    Kennedy, C J; Higgs, Dave; Tierney, Keith

    2004-10-01

    Juvenile rainbow trout (Oncorhynchus mykiss) were fasted or fed one of three isoenergetic diets varying in protein and lipid content at full satiation levels or half rations for up to 9 weeks. At 3, 6, and 9 weeks, fish in each treatment group were dosed intraperitoneally with 10 mg tritiated benzo[a]pyrene [3H]-B[a]P/kg (B[a]P) to examine the effects of diet composition and energy intake on xenobiotic biotransformation and excretion. The percent dose eliminated during the experiment did not differ among fish receiving the different diet compositions or rations (range 73% to 84%). However, it was significantly decreased (to 53%) in the group that was fasted for 9 weeks. Examination of fish fasted for 6 and 9 weeks showed a significant increase in the proportion of phase I metabolites and a concomitant decrease in the proportion of phase II metabolites found in bile compared with all other groups. Also, fish that were fasted for 9 weeks produced proportionately less 9,10-dihydroxy-benzo[a]pyrene-trans-9,10-diol, more 3-hydroxybenzo[a]pyrene and 9-hydroxybenzo[a]pyrene, and more glucuronic acid conjugates compared with all other groups. Thus, dietary protein and lipid concentration did not appear to affect either the rate of B[a]P metabolism or its excretion; however, prolonged fasting resulted in a shift in metabolite profiles and decreased excretion.

  10. Degradation of pyrene and characterization of Saccharothrix sp. PYX-6 from the oligotrophic Tianchi Lake in Xinjiang Uygur Autonomous Region, China

    Institute of Scientific and Technical Information of China (English)

    HU Yuting; REN Fenghua; ZHOU Peijin; XIA Min; LIU Shuangjiang

    2003-01-01

    Bacterial strain PYX-6 that utilizes anthracene, phenanthrene, or pyrene for carbon and energy sources for growth was isolated from a non-polluted lake (Tianchi Lake) in Xinjiang Uygur Autonomons Region of China. Its morphology, physiological and biochemical properties, cell wall pattern and G+C mol% content of DNA molecules were characterized. The 16S rRNA gene of strain PYX-6 was sequenced and analyzed for similarities to related bacterial species. Results indicated that strain PYX-6 is a member of the Genus Saccharothrix, and the strain was named Saccharothrix sp. PYX-6. When pyrene was the sole carbon source in cultural medium, the strain PYX-6 assimilated pyrene for growth and 0.005% of yeast extract stimulated pyrene degradation and assimilation. The optimal pH of cultural medium and the optimal shaking frequency during cultivation were 6-8 and 200 r/m, respectively. It was found that the disappearance of pyrene in medium occurred before significant growth of strain PYX-6 took place. Phthalic acid, benzylacetic acid, and benzylpropenoic acid were detected as catabolic intermediates during pyrene degradation with mass spectroscopy and this result indicated that Saccharothrix sp. PYX-6 adopted a pathway that is different from the pathway of the previously reported pyrene-degrading Mycobacterium sp. PYR-1.

  11. Pharmacokinetics of benzo(alpha)pyrene in the isolated perfused rabbit lung: the influence of benzo(alpha)pyrene, n-dodecane, particulate, or sulfur dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Morgan, D.D.; Warshawsky, D.; Niemeier, R.W.; Bingham, E.

    1984-12-01

    The pharmacokinetics of benzo(a)pyrene (BaP) in the isolated perfused rabbit lung (IPL) following pretreatment of the whole animal or simultaneous administration to the IPL with n-dodecane, ferric oxide, crude airborne particulate (CAP), fly ash or sulfur dioxide have been investigated using a one compartment model. The rate constant for the appearance (ka) of BaP in the blood, the clearance of BaP from the blood, and the rate of appearance of BaP metabolites (RAM) were the kinetic parameters determined. BaP entered the blood rapidly with an average half-life of 11 min in experiments in which the IPLs received only BaP on perfusion. The logarithms of the clearances from these experiments were linearly correlated with the RAMs. In these experiments, pretreatment of the whole animal with BaP produced a 48-55-fold increase in BaP clearance while pretreatment with n-dodecane increased the clearance 4-fold in comparison with no pretreatment. Pretreatment with ferric oxide or ferric oxide and BaP increased the clearance by factors of 5.5 and 1.5, respectively, over those of unpretreated and BaP pretreated experiments.

  12. Further characterization of benzo[a]pyrene diol-epoxide (BPDE)-induced comet assay effects.

    Science.gov (United States)

    Bausinger, Julia; Schütz, Petra; Piberger, Ann Liza; Speit, Günter

    2016-03-01

    The present study aims to further characterize benzo[a]pyrene diol-epoxide (BPDE)-induced comet assay effects. Therefore, we measured DNA effects by the comet assay and adduct levels by high-performance liquid chromatography (HPLC) in human lymphocytes and A549 cells exposed to (±)-anti-benzo[a]pyrene-7,8-diol 9,10-epoxide [(±)-anti-BPDE] or (+)-anti-benzo[a]pyrene-7,8-diol 9,10-epoxide [(+)-anti-BPDE]. Both, the racemic form and (+)-anti-BPDE, which is the most relevant metabolite with regard to mutagenicity and carcinogenicity, induced DNA migration in cultured lymphocytes in the same range of concentrations to a similar extent in the alkaline comet assay after exposure for 2h. Nevertheless, (+)-anti-BPDE induced significantly enhanced DNA migration after 16 and 18h post-cultivation which was not seen in response to (±)-anti-BPDE. Combination of the comet assay with the Fpg (formamidopyrimidine-DNA glycosylase) protein did not enhance BPDE-induced effects and thus indicated the absence of Fpg-sensitive sites (oxidized purines, N7-guanine adducts, AP-sites). The aphidicolin (APC)-modified comet assay suggested significant excision repair activity of cultured lymphocytes during the first 18h of culture after a 2 h-exposure to BPDE. In contrast to these repair-related effects measured by the comet assay, HPLC analysis of stable adducts did not reveal any significant removal of (+)-anti-BPDE-induced adducts from lymphocytes during the first 22h of culture. On the other hand, HPLC measurements indicated that A549 cells repaired about 70% of (+)-anti-BPDE-induced DNA-adducts within 22h of release. However, various experiments with the APC-modified comet assay did not indicate significant repair activity during this period in A549 cells. The conflicting results obtained with the comet assay and the HPLC-based adduct analysis question the real cause for BPDE-induced DNA migration in the comet assay and the reliability of the APC-modified comet assay for the

  13. Novel Pyrene-armed Calix[4]arenes through Triazole Connec-tion: Ratiometric Fluorescent Chemosensor for Zn2+ and Promising Structure for Integrated Logic Gates

    Institute of Scientific and Technical Information of China (English)

    ZHU Lin-Na; GONG Shao-Long; GONG Shu-Ling; YANG Chu-Luo; QIN Jin-Gui

    2008-01-01

    Two novel pyrene-armed calix[4]arenes by triazole connection were synthesized using "click" chemistry. Com-pound 1 with two pyrene subunits appended to the lower rims of the calix[4]arene shows ratiometric fluorescence response toward Zn2+, and selective fluorescence quenching toward heavy metal ions such as Cu2+, Hg2+ and pb2+; while compound 2 with one pyrene subunit exhibits significant fluorescence quenching toward Cu2+ and moderate quenching behaviour toward Hg2+. By utilizing the different fluorescence behavior of 1 toward Zn2+and Cu2+, inhi-bition (INH) and not or (NOR) logic gates were established.

  14. Evidence for the involvement of cytochrome P-450 in reduction of benzo(a)pyrene 4,5-oxide by rat liver microsomes

    Energy Technology Data Exchange (ETDEWEB)

    Kato, R.; Iwasaki, K.; Shiraga, T.; Noguchi, H.

    1976-01-01

    Benzo(a)pyrene 4,5-oxide is reduced to benzo(a)pyrene by microsomes in the presence of NADPH. Carbon monoxide and oxygen inhibit this reduction. The liver has highest activity which is almost lacking in new-born rats. Phenobarbital as well as 3-methylcholanthrene pretreatment increases the epoxide reduction. Additions of FMN or methylviologen stimulate the epoxide reduction; dimethylaniline N-oxide and cumene hydroperoxide are inhibitory. These results indicate that benzo(a)pyrene 4,5-oxide is reduced by the reduced form of cytochrome P-450.

  15. Remediation of Soils Contaminated with Pyrene and Benzo[a] Pyrene by Microorganisms%微生物对芘和苯并[a]芘污染土壤的修复

    Institute of Scientific and Technical Information of China (English)

    王辰; 王翠苹; 刘海彬; 许伟; 孙红文; 于晨; 张瑞华

    2011-01-01

    Degradation of pyrene and benzo [a]pyrene in soils by Bacillus subtilis, white rot fungus and mixed degrading bacteria that were isolated from oil contaminated soil were investigated. Effects of TweenS0 and glucose on biodegradation of PAHs were also preliminarily discussed. Results showed that the residual rate for pyrene was 7.58%±0.59% and 8.69%±1.35%on the 60th day when degraded by Bacillus sub.tills and the isolated bacteria respectively, while it was 48.18%±0.56% for the uninoculated control soil. Benzo[a] pyrene also showed residual rate with 66.27%±3.03%, 62.28%±2.54% and 67.67%±2.98%on the 60th day in remediation soils by Bacillus subtilis, white rot fungus and the isolated degrading bacteria respectively.And in the control soil, 70.25%±1.62% of the initial benzo [a]pyrene was left after 60d. After adding TweenS0, the residual rate of pyrene by Bacillus subtilis jecreased by 2.41%. As for benzo [a]pyrene, the residual rate decreased by 12.72% for Bacillus subtilis and 14.59% for white rot fungus. Results showed that the residual rate of pyrene by Bacillus subtilis decreased by 2.30% after adding glucose, while it decreased by 5.39% and 11.93% for benzo[a]pyrene degraded by Bacillus subtilis and white rot fungus respectively.%将枯草芽孢杆菌、白腐真菌和分离筛选菌群分别用于芘和苯并[a]芘污染土壤的修复,比较其修复性能,并对表面活性物剂Tween80和葡萄糖对修复效果的影响规律做了初步探讨.结果表明,60 d时,枯草芽孢杆菌和分离筛选菌修复芘污染的土壤,芘的残留率分别为7.58%±0.59%和8.69%±61.35%,空白残留率为48.18%±56%;对于枯草芽孢杆菌,白腐真菌和分离筛选菌对土壤中苯并[a]芘的修复,在60 d时,苯并[a]芘的残留率分别为6627%±3.03%,62.28%±2.54%和67.67%±2.98±,空白残留率为70.25%±1.62%60 d时,加入Tween80后芘的残留率比仪加入枯草芽孢杆菌的降低了2.41%,而苯并[a]

  16. Reduced-glutathione concentrations in Boleophthalmus pectinirostris tissues exposed to benzo(a)pyrene

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The concentrations of reduced-glutathione (GSH) in liver and ovary of Boleophthalmus pectinirostris are quantified. The concentrations of GSH in the ovary are much higher than that of GSH in the liver(nearly 3 times of the liver). The study also investigates the changes of GSH contents in the two organs while the fishes were exposed to benzo(a)pyrene(BaP) at concentrations of 0, 0.05, 0.2 and 0.5mg/L respectively for up to a week. The concentrations of GSH in the liver of BaP-exposed fish increased significantly with dose, whereas the oncentrations of GSH in the ovary decreased significantly compared to controls. The results suggested that both the liver and the ovary are the primary organ in BaP metabolism, and that the changes of GSH levels may represent an adaptive response or toxic effect to BaP exposure.

  17. 1-Imino Nitroxide Pyrene, a Burst-type H+ Fluorescent Switch

    Institute of Scientific and Technical Information of China (English)

    Jun LI; Hong Mei WANG; Hui Min MA; De Qing ZHANG; Shao Xiang XIONG

    2005-01-01

    1-Imino nitroxide pyrene 1 has been characterized as a H+ fluorescent switch. The effects of various interfering species, solvents and the irradiation of ultraviolet light on the fluorescence intensity of 1 are also investigated. 1 fluoresces weakly in the 85% ethanol media containing no more than 4.5×10-5 mol/L of H+ (HCl), but can produce a burst increase of about 4times in the fluorescence intensity when the concentration of H+ is increased to or over 4.9×10-5mol/L. The extremely sharp response of 1 to H+ occurs only within such a narrow concentration range. Moreover, the decrease of H+ concentration through adding sodium hydroxide causes the fluorescence quenching, suggesting that 1 may serve as a fluorescent switch for monitoring the concentration change of H+ around the point of 4.5× 10-5 mol/L.

  18. Liquid chromatographic determination of benzo(a)pyrene in total particulate matter of cigarette smoke

    Energy Technology Data Exchange (ETDEWEB)

    Tomkins, B.A.; Jenkins, R.A.; Griest, W.H.; Reagan, R.R.; Holladay, S.K.

    1985-09-01

    The benzo(a)pyrene (BaP) delivery of reference and commercially available tobacco cigarettes, as well as reference and placebo marijuana cigarettes, is determined using a sequential liquid chromatographic/liquid chromatographic procedure. The total particulate matter of sample cigarette smoke is collected using a Cambridge filter pad, which is ultrasonically extracted with acetone. The resulting extract is filtered, then fractionated using semipreparative-scale normal phase liquid chromatography (LC). Quantitative determination is achieved using analytical-scale reverse phase LC equipped with a fluorescence detector. The method is precise (+/- 10-15% relative standard deviation) and yields 85% or better BaP recovery at the ng/cig. level. A single pad may be analyzed in 8 person-hours, while a more typical lot of 12 pads (6 pads each for 2 cigarette brands) may be analyzed in 10 person-days.

  19. Highly selective fluorescent chemosensor for Na+ based on pyrene-modified calix[4]arene derivative

    Institute of Scientific and Technical Information of China (English)

    WANG KeRang; GUO DongSheng; JIANG BangPing; LIU Yu

    2009-01-01

    A novel calix[4]arene derivative with pyrene fluorophores at the upper rim and tetraester ionophores at the lower rim was synthesized in six steps, and its structure was proved by NMR and ESi-MS spectro-scopies. Furthermore, the chemosensing behavior of the host compound for alkali and alkaline earth metal ions was investigated by fluorescence spectroscopy. The obtained results show that the calix-arene host can selectively bind sodium ion with the complexation stability constant of 2190 mol-1.L. The complexation with sodium ion can pronouncedly induce the excimer emission to decrease and the monomer emission to increase, whereas the addition of the other alkali and alkaline earth metal ions does not cause appreciable changes in the fluorescence spectrum of the host compound. The present calix[4]arene derivative displays potential application as fluorescent chemosensor for sodium ion.

  20. Dynamics of benzo[α]pyrene accumulation in soils under the influence of aerotechnogenic emissions

    Science.gov (United States)

    Sushkova, S. N.; Minkina, T. M.; Mandzhieva, S. S.; Deryabkina, I. G.; Vasil'eva, G. K.; Kızılkaya, R.

    2017-01-01

    The regularities of benzo[α]pyrene (BaP) accumulation and distribution in chernozems (Haplic Chernozems), meadow-chernozemic soils (Haplic Chernozems (Stagnic)), and alluvial soils (Fluvisols) affected by the aerotechnogenic emissions from the Novocherkasskaya Electric Power Station (NEPS) were studied on the basis of long-term (2002-2011) monitoring data. A 5-km-wide zone stretching to the northwest from the electric power station and coinciding with the predominant wind direction was found to be most contaminated, with the maximum accumulation of BaP at about 1.6 km from the source. The coefficients of vertical BaP distribution between the layers of 0-5 and 5-20 cm closely correlated with the contents of physical clay, clay, and humus, and with the cation exchange capacity. The content of BaP in soils was shown to be indicative of the level of technogenic loads related to the combustion products of hydrocarbon fuels.

  1. Chlorophyll catalyse the photo-transformation of carcinogenic benzo[a]pyrene in water.

    Science.gov (United States)

    Luo, Lijuan; Lai, Xueying; Chen, Baowei; Lin, Li; Fang, Ling; Tam, Nora F Y; Luan, Tiangang

    2015-08-04

    Algal blooms cause great damage to water quality and aquaculture. However, this study showed that dead algal cells and chlorophyll could accelerate the photo-transformation of benzo[a]pyrene (BaP), a ubiquitous and persistent pollutant with potently mutagenic and carcinogenic toxicities, under visible light irradiation. Chlorophyll was found to be the major active substance in dead algal cells, and generated a high level of singlet oxygen to catalyse the photo-transformation of BaP. According to various BaP metabolites formed, the degradation mechanism was proposed as that chlorophyll in dead algal cells photo-oxidized BaP to quinones via photocatalytic generation of singlet oxygen. The results provided a good insight into the role of chlorophyll in the photo-transformation of organic contaminants and could be a possible remediation strategy of organic pollutants in natural environment.

  2. -pyrrole substituted porphyrin-pyrene dyads using vinylene spacer: Synthesis, characterization and photophysical properties

    Indian Academy of Sciences (India)

    P Silviya Reeta; Ravi Kumar Kanaparthi; L Giribabu

    2013-03-01

    We have designed and synthesized donor-acceptor conjugates having donor pyrene at the pyrrole- position of either free-base porphyrin or Zn(II) porphyrin using vinylene spacer. Both the dyads have been completely characterized by elemental analysis,MALDI-MS, UV-Vis., and fluorescence (steady state and timeresolved) spectroscopies as well as cyclic voltammetry. The absorption maxima of both dyads are red-shifted by 8-12 nm. The ground state properties showed that there exist minimum - interaction between the aromatic subunits of these D-A systems. Quenched emission was observed in both the dyads when excited at 290 nm. The quenched emission explained in terms of intramolecular excitation energy transfer competes with the photo-induced electron transfer reaction in these D-A system.

  3. Bioremediation of phenanthrene, chrysene and benzo[a]pyrene by fungi screened from nature

    Directory of Open Access Journals (Sweden)

    Tony Hadibarata

    2009-09-01

    Full Text Available Laccase of Polyporus sp. S133 was able to oxidize most of the 3 different rings amount polycyclic aromatic hydrocarbons (PAHs tested. Phenanthrene was removed by 89% followed by chrysene and benzo[a]pyrene which were oxidized by 66 and 55%, respectively. Addition of 1-hydroxybenzotriazole (HBT to the reaction mixture increased oxidation of PAHs, especially phenanthrene was almost completely removed from the reaction mixture. Oxidation of chrysene and benzo[a]anthracene increased 12 and 10% with the mediator to 78 and 65% in the presence of HBT. PAH-quinones as oxidation products were formed from all PAH to different extents. A part of PAH was polymerized in the laccase/mediator system to products of weight-average molecular weight (MW. The correlation of the ionization potentials of PAH with the oxidation of these compounds is limited to the alternating PAH.

  4. The Electronic States of a Double Carbon Vacancy Defect in Pyrene: A Model Study for Graphene

    CERN Document Server

    Machado, Francisco B C; Lischka, Hans

    2016-01-01

    The electronic states occurring in a double vacancy defect for graphene nanoribbons have been calculated in detail based on a pyrene model. Extended ab initio calculations using the MR configuration interaction (MRCI) method have been performed to describe in a balanced way the manifold of electronic states derived from the dangling bonds created by initial removal of two neighboring carbon atoms from the graphene network. In total, this study took into account the characterization of 16 electronic states (eight singlets and eight triplets) considering unrelaxed and relaxed defect structures. The ground state was found to be of 1Ag character with around 50% closed shell character. The geometry optimization process leads to the formation of two five-membered rings in a pentagon octagon pentagon structure. The closed shell character increases thereby to ~70%, the analysis of unpaired density shows only small contributions confirming the chemical stability of that entity. For the unrelaxed structure the first fi...

  5. Applications of PDMS partitioning methods in the study of biodegradation of pyrene in the

    DEFF Research Database (Denmark)

    Tejeda-Agredano, MC; Gouliarmou, Varvara; Ortega-Calvo, JJ

    fractions to contaminated soils often causes an enhanced biodegradation and desorption of these compounds from soils. Other mechanisms proposed as operating in HS-mediated enhancements of biodegradation include the promotion of compound solubility and a direct access to HS-sorbed chemicals due...... to the physical association of bacteria and HS. Here, we propose the use of partitioning techniques using poly(dimethylsiloxane) (PDMS) to study the effect of binding of pyrene to a dissolved humic acid isolated from soil on biodegradation of this PAH by a representative soil bacterium. The application...... of these techniques in biodegradation studies may solve many questions about enhancements in diffusive mass transfer, in capacity/speciation and in dissolution. Therefore, our study may provide new insights into the effects of HS on microbial degradation of polycyclic aromatic hydrocarbons (PAHs)....

  6. Assimilation efficiency for sediment-sorbed benzo(a)pyrene by Diporeia spp.

    Science.gov (United States)

    Lydy, M.J.; Landrum, P.F.

    1993-01-01

    Two methods are currently available for determining contaminant assimilation efficiencies (AE) from ingested material in benthic invertebrates. These methods were compared using the Great Lakes amphipod Diporeia spp. and [14C]benzo(a)pyrene (BaP) sorbed to Florissant sediment (BaP). The failure of the dual-labeled approach was not a result of an uneven distribution of the labels among particle size classes, but more likely resulted from differential sorption of the two isotopically labeled materials to particles of differing composition. The [14C]BaP apparently sorbs to organic particles that are selectively ingested, while the 51Cr apparently sorbs to particles which are selectively excluded by Diporeia. The dual-labeled approach would be a viable and easier experimental approach for determining AE values if the characteristics that govern selective feeding can be determined.

  7. The reaction of N-(1-pyrene)maleimide with sarcoplasmic reticulum.

    Science.gov (United States)

    Papp, S; Kracke, G; Joshi, N; Martonosi, A

    1986-01-01

    The excimer fluorescence of the adduct of N-(1-pyrene)maleimide (PMI) with the Ca2+-ATPase was proposed as a probe of ATPase-ATPase interactions in sarcoplasmic reticulum (Lüdi and Hasselbach, Eur. J. Biochem., 1983, 130:5-8). We tested this proposition by analyzing the spectral properties and stoichiometry of the adducts of pyrenemaleimide with sarcoplasmic reticulum and with dithiothreitol and by comparing the effects of various detergents on the excimer fluorescence of the two adducts, with their influence on the sedimentation characteristics, ATPase activity, and light scattering of the pyrenemaleimide-labeled sarcoplasmic reticulum. These studies indicate that pyrenemaleimide reacts nearly randomly with several SH groups on the Ca2+-ATPase, and suggest that the observed excimer fluorescence of pyrenemaleimide-labeled sarcoplasmic reticulum may reflect intramolecular phenomena rather than ATPase-ATPase interactions. Further work is required to establish the relative contribution of intra- and intermolecular mechanisms to the excimer fluorescence. PMID:2937461

  8. The spectrochemical behavior of composites based on poly (para-phenylenevinylene), reduced graphene oxide and pyrene

    Science.gov (United States)

    Ilie, Mirela; Baibarac, Mihaela

    2017-10-01

    A new composite material based on poly (para-phenylenevinylene) (PPV), pyrene (Py) and reduced graphene oxide (RGO) is synthesized using thermal conversion route. The properties of this material are investigated by Raman scattering, photoluminescence (PL), infrared (IR) and ultraviolet-visible (UV-Vis) spectroscopy. Adding Py at PPV precursor solution (PPV PS) containing RGO, yields to important modifications in both vibrational and electronic properties of these composites. The presence of Py into PPV matrix determines a blue shift of PPV PL. According to Raman and IR studies, PPV is non-covalently functionalized with Py which interacts forward with RGO through π-π interactions causing an important modification into the polymer chains conjugation length.

  9. Tetraaryl pyrenes: photophysical properties, computational studies, crystal structures, and application in OLEDs

    KAUST Repository

    El-Assaad, Tarek H.

    2015-10-15

    Pyrene was derivatized in positions 1, 3, 6, and 8 to yield a series of nine tetraarylpyrenes for which absorption, emission, emission lifetimes and solvatochromism in solution were determined. The fluorescence quantum yields in thin films and crystalline state, electrochemistry, and quantum-chemical calculations were completed for the series along with the X-ray crystal structure analysis of compounds 1, 2, 4, 5, 7, and 9. Compounds 2, 3, 4 as well as 7 were identified as the most suitable candidates for OLED application. Notably, in an unoptimized single-layer device geometry, these compounds exhibited blue electroluminescence coupled with impressively low turn-on voltages and high maximum luminances such as 2.8 V and 13 542 cd m-2 at 8.2 V for compound 2, respectively. © The Royal Society of Chemistry 2016.

  10. Histologic and skeletal abnormalities in benzo(a)pyrene-treated rainbow trout alevins

    Energy Technology Data Exchange (ETDEWEB)

    Hose, J.E.; Hannah, J.B.; Puffer, H.W.; Landolt, M.L.

    1984-11-01

    Histological and skeletal examinations were performed on rainbow trout (Salmo gairdneri Richardson) alevins reared in 0.00, 0.08, 0.21, 0.39, 1.48, 2.40 or 2.99 ng/ml aqueous benzo(a)pyrene (BaP). Nuclear pycnosis and karyorrhexis were most common in neuroectodermal and mesodermal derivatives and in liver of BaP-treated alevins. Microphthalmia was observed in 17% of the test fish and was frequently associated with a patent optic fissure. Depressed mitotic rates in the retina and brain (but not liver) were observed in alevins reared in 0.21 to 1.48 ng/ml aqueous BaP. Test alevins had a significantly higher incidence of skeletal malformations in the skull and vertebral column, and abnormalities of vertebral arcualia often corresponded to areas of kyphoscoliotic flexures. 43 references, 3 figures, 4 tables.

  11. Predicting lung dosimetry of inhaled particleborne benzo[a]pyrene using physiologically based pharmacokinetic modeling

    Science.gov (United States)

    Campbell, Jerry; Franzen, Allison; Van Landingham, Cynthia; Lumpkin, Michael; Crowell, Susan; Meredith, Clive; Loccisano, Anne; Gentry, Robinan; Clewell, Harvey

    2016-01-01

    Abstract Benzo[a]pyrene (BaP) is a by-product of incomplete combustion of fossil fuels and plant/wood products, including tobacco. A physiologically based pharmacokinetic (PBPK) model for BaP for the rat was extended to simulate inhalation exposures to BaP in rats and humans including particle deposition and dissolution of absorbed BaP and renal elimination of 3-hydroxy benzo[a]pyrene (3-OH BaP) in humans. The clearance of particle-associated BaP from lung based on existing data in rats and dogs suggest that the process is bi-phasic. An initial rapid clearance was represented by BaP released from particles followed by a slower first-order clearance that follows particle kinetics. Parameter values for BaP-particle dissociation were estimated using inhalation data from isolated/ventilated/perfused rat lungs and optimized in the extended inhalation model using available rat data. Simulations of acute inhalation exposures in rats identified specific data needs including systemic elimination of BaP metabolites, diffusion-limited transfer rates of BaP from lung tissue to blood and the quantitative role of macrophage-mediated and ciliated clearance mechanisms. The updated BaP model provides very good prediction of the urinary 3-OH BaP concentrations and the relative difference between measured 3-OH BaP in nonsmokers versus smokers. This PBPK model for inhaled BaP is a preliminary tool for quantifying lung BaP dosimetry in rat and humans and was used to prioritize data needs that would provide significant model refinement and robust internal dosimetry capabilities. PMID:27569524

  12. Pyrene-based fluorescent ambidextrous gelators: scaffolds for mechanically robust SWNT-gel nanocomposites.

    Science.gov (United States)

    Mandal, Deep; Kar, Tanmoy; Das, Prasanta Kumar

    2014-01-27

    With the rapid progress in the development of supramolecular soft materials, examples of low-molecular-weight gelators (LMWGs) with the ability to immobilise both water and organic solvents by the same structural scaffold are very limited. In this paper, we report the development of pyrene-containing peptide-based ambidextrous gelators (AGs) with the ability to efficiently gelate both organic and aqueous solvents. The organo- and hydrogelation efficiencies of these gelators are in the range 0.7-1.1% w/v in various organic solvents and 0.5-5% w/v in water at certain acidic pH values (pH 2.0-4.0). Moreover, for the first time, AGs have been utilised to prepare single-walled carbon-nanotube (SWNT)-included soft nanocomposites in both hydro- and organogel matrices. The influence of different non-covalent interactions such as hydrogen bonding, hydrophobic, π-π and van der Waals interactions in self-assembled gelation has been studied in detail by circular dichroism, FTIR, variable-temperature NMR, 2D NOESY and luminescence spectroscopy. Interestingly, the presence of the pyrene moiety in the structure rendered these AGs intrinsically fluorescent, which was quenched upon successful integration of the SWNTs within the gel. The prepared hydro- and organogels along with their SWNT-integrated nanocomposites are thermoreversible in nature. The supramolecular morphologies of the dried gels and SWNT-gel nanocomposites have been studied by transmission electron microscopy, fluorescence microscopy and polarising optical microscopy, which confirmed the presence of three-dimensional self-assembled fibrillar networks (SAFINs) as well as the integrated SWNTs. Importantly, rheological studies revealed that the inclusion of SWNTs within the ambidextrous gels improved the mechanical rigidity of the resulting soft nanocomposites up to 3.8-fold relative to the native gels.

  13. Benzo[a]pyrene in urban environments of eastern Moscow: pollution levels and critical loads

    Science.gov (United States)

    Kasimov, Nikolay S.; Kosheleva, Natalia E.; Nikiforova, Elena M.; Vlasov, Dmitry V.

    2017-02-01

    Polycyclic aromatic hydrocarbons (PAHs), particularly benzo[a]pyrene (BaP), are toxic compounds emitted from various anthropogenic sources. Understanding the BaP concentrations, dynamics and decomposition in soil is required to assess the critical loads of BaP in urban environments. This study is the first attempt to evaluate all major input and output components of benzo[a]pyrene (BaP) balance and to calculate the permissible load on the urban environment in different land-use zones in the Eastern district of Moscow. BaP contamination of the snow cover in the Eastern district of Moscow was related to daily BaP fallout from the atmosphere. In 2010, the mean content of the pollutant in the snow dust was 1942 ng g-1, whereas the average intensity of its fallout was 7.13 ng m-2 per day. Across the territory, BaP winter fallout intensities varied from 0.3 to 1100 ng m-2 per day. The average BaP content in the surface (0-10 cm) soil horizons was 409 ng g-1, which is 83 times higher than the local background value and 20 times higher than the maximum permissible concentration (MPC) accepted in Russia. The variations in soil and snow BaP concentrations among different land-use zones were examined. A significant contribution of BaP from the atmosphere to urban soils was identified. Based on the measurements of BaP atmospheric fallout and BaP reserves in the soils, the critical loads of BaP for the land-use zones in the Eastern district were calculated for different values of degradation intensity and different exposure times. It was established that at an annual degradation intensity of 1-10 %, ecologically safe BaP levels in the soils of all land-use zones, excluding the agricultural zone, will only be reached after many decades or centuries.

  14. Effects of the invasive polychaete, Marenzelleria viridis, on the fate of sediment associated pollutants – a microcosm study with 14C-labelled pyrene

    DEFF Research Database (Denmark)

    Banta, Gary Thomas; Hedman, Jenny Elisabet

    the impact of depositing labile organic matter (seston) on the sediment surface. Worms clearly enhanced the release of pyrene and degradation metabolites from the sediment to the overlying water in all cases, mostly due to the initial flushing of sediments during burrow establishment. Surprisingly...... on the fate of deeply buried sediment-associated pollutants in the historically polluted Baltic Sea. We report here the results of an experimental microcosm study examining the fate of 14C radiolabelled pyrene (a 4-ring PAH) in sediment microcosms with and without Marenzelleria viridis. We also investigated......, there was no clear effect of worms on the mineralization of pyrene to CO2, where a complicated interaction between bioturbation and the presence of labile organic matter was observed. Furthermore, the ultimate fate of the increased release of sediment-associated pyrene and its metabolites to the water is unknown....

  15. SEPARATION AND CHARACTERIZATION OF TETROL METABOLITES OF BENZO[A]PYRENE-DNA ADDUCTS USING HPLC AND SOLID-MATRIX ROOM TEMPERATURE LUMINESCENCE. (R824100)

    Science.gov (United States)

    AbstractFour tetrols of benzo[a]pyrene-DNA adducts were separated using reversed-phase high performance liquid chromatography. Chromatographic fractions containing a given tetrol were readily characterized with solid-matrix room temperature luminescence techniques. So...

  16. Biodegradation of benzo[a]pyrene by the mixed culture of Bacillus cereus and Bacillus vireti isolated from the petrochemical industry.

    Science.gov (United States)

    Mohandass, Ramya; Rout, Pallabi; Jiwal, Sonia; Sasikala, Chitrambalam

    2012-11-01

    Polycyclic aromatic hydrocarbons are a group of compounds that pose threat to humans and animal life. Methods to reduce the amount of PAHs in the environment are continuously being sought. The bacterial consortium capable of utilizing benzo(a)pyrene as the sole source of carbon and energy was isolated from petrochemical soil. The isolates were identified as Bacillus cereus and Bacillus viretibased on morphological characterization, and 16S rDNA gene sequence analysis. About 58.98% of benzo(a)pyrene at concentration of 500 mg l(-1) in mineral salts medium were removed by bacterial consortium. GC mass spectral analysis showed the presence of metabolite cis-4-(7-hydroxypyren-8-yl)-2-oxobut-3enoic acid. The results indicate that the bacterial consortium is a new bacterial resource for biodegrading benzo(a)pyrene and might be used for bioremediation of sites heavily contaminated by benzo[a]pyrene and its derivatives.

  17. Thermal properties and physicochemical behavior in aqueous solution of pyrene-labeled poly(ethylene glycol-polylactide conjugate

    Directory of Open Access Journals (Sweden)

    Chen WL

    2015-04-01

    Full Text Available Wei-Lin Chen,1,2 Yun-Fen Peng,1,3 Sheng-Kuo Chiang,1 Ming-Hsi Huang1–3 1National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Miaoli, Taiwan; 2Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan; 3PhD Program in Tissue Engineering and Regenerative Medicine, National Chung Hsing University, Taichung, Taiwan Abstract: A fluorescence-labeled bioresorbable polymer was prepared by a coupling reaction of poly(ethylene glycol-polylactide (PEG-PLA with carboxyl pyrene, using N,N’-diisopropylcarbodiimide/1-hydroxy-7-azabenzotriazole (DIC/HOAt as a coupling agent and 4-dimethylaminopyridine (DMAP as a catalyst. The obtained copolymer, termed PEG-PLA-pyrene, was characterized using various analytical techniques, such as gel permeation chromatography (GPC, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS, proton nuclear magnetic resonance (1H-NMR, infrared spectroscopy (IR, differential scanning calorimetry (DSC, and thermogravimetric analysis (TGA, to identify the molecular structure and to monitor the thermal property changes before and after the reaction. The presence of a pyrene moiety at the end of polylactide (PLA did not alter the crystallization ability of the poly(ethylene glycol (PEG blocks, indicating that the conjugate preserved the inherent thermal properties of PEG-PLA. However, the presence of PEG-PLA blocks strongly reduced the melting of pyrene, indicating that the thermal characteristics were sensitive to PEG-PLA incorporation. Regarding the physicochemical behavior in aqueous solution, a higher concentration of PEG-PLA-pyrene resulted in a higher ultraviolet-visible (UV-vis absorbance and fluorescence emission intensity. This is of great interest for the use of this conjugate as a fluorescence probe to study the in vivo distribution as well as the internalization and intracellular localization of polymeric micelles

  18. Effects of the polychaetes Arenicola marina and Nereis diversicolor on microbial pyrene mineralization

    DEFF Research Database (Denmark)

    Timmermann, Karen; Banta, Gary T.; Johnsen, Anders R.;

    2008-01-01

    The effects of 2 polychaetes, Nereis diversicolor and Arenicola marina, on the microbial mineralization of the organic contaminant pyrene, a polycyclic aromatic hydrocarbon (PAH), were followed over 44 d. We also examined whether the effect of the polychaetes was caused by enhanced oxygen supply,...... by the increased oxygen supply due to burrow construction and irrigation. In contrast, these worms decreased pyrene bioavailability and, hence, counteracted to some extent the stimulating effect of irrigation....

  19. Effect of eugenol on the mutagenicity of benzo[a]pyrene and the formation of benzo[a]pyrene-DNA adducts in the X-lacZ-transgenic mouse.

    NARCIS (Netherlands)

    Rompelberg, C.J.M.; Steenwinkel, M.J.S.T.; Asten, J.G. van; Delft, J.H.M. van; Baan, R.A.; Verhagen, H.

    1996-01-01

    To study the possible reduction by eugenol of the mutagenicity and genotoxicity of benzoja]pyrene (B[a]P) in vivo, the X-lacZ-transgenic mouse strain 40.6 (Muta(TM)Mouse) was used. Male mice were fed a diet containing 0.4% (w/w) eugenol or a control diet for 58 days. On day 10, half of the mice rece

  20. Hasse diagram as a green analytical metrics tool: ranking of methods for benzo[a]pyrene determination in sediments.

    Science.gov (United States)

    Bigus, Paulina; Tsakovski, Stefan; Simeonov, Vasil; Namieśnik, Jacek; Tobiszewski, Marek

    2016-05-01

    This study presents an application of the Hasse diagram technique (HDT) as the assessment tool to select the most appropriate analytical procedures according to their greenness or the best analytical performance. The dataset consists of analytical procedures for benzo[a]pyrene determination in sediment samples, which were described by 11 variables concerning their greenness and analytical performance. Two analyses with the HDT were performed-the first one with metrological variables and the second one with "green" variables as input data. Both HDT analyses ranked different analytical procedures as the most valuable, suggesting that green analytical chemistry is not in accordance with metrology when benzo[a]pyrene in sediment samples is determined. The HDT can be used as a good decision support tool to choose the proper analytical procedure concerning green analytical chemistry principles and analytical performance merits.

  1. Cassia senna inhibits mutagenic activities of benzo[a]-pyrene, aflatoxin B1, shamma and methyl methanesulfonate.

    Science.gov (United States)

    al-Dakan, A A; al-Tuffail, M; Hannan, M A

    1995-10-01

    Ethanol extract of Senokot tablets (Cassia senna concentrate used as vegetable laxative), was found to be non-mutagenic while it inhibited the mutagenicity of benzo[a]pyrene, shamma, aflatoxin B1 and methyl methanesulfonate in the Ames histidine reversion assay using the Salmonella typhimurium tester strain TA98. While the Senokot extract completely inhibited the mutagenicity of promutagens (i.e. metabolic activation dependent) like benzo[a]pyrene and shamma, it reduced the mutagenic activity of the direct acting mutagen methyl methanesulfonate by only 58%. The mutagen aflatoxin B1 showed a 25-fold increase in the number of histidine revertants per plate at low concentrations (1.0-4.0 micrograms/plate) in the presence of metabolic activation system while at high concentrations (10.0-30.0 micrograms/plate) it proved to be weakly mutagenic (with a 5-fold increase in the number of histidine revertants/plate) without metabolic activation. The Senokot extract completely inhibited the mutagenic effect of low concentrations of aflatoxin B1 in the presence of metabolic activation but not that resulting from higher concentrations without metabolic activation. The results obtained with benzo[a]pyrene, shamma and aflatoxin B1 indicated that the antimutagenic effects of Senokot extract could be largely due to an interaction with the metabolic process involved in the activation of procarcinogens. However, the results obtained with methyl methanesulfonate suggested that factors in Senokot may also interact with direct mutagens to produce some antimutagenic effects. An ethanol extract of crude senna leaves found to be weakly mutagenic also inhibited (though less than Senokot) the mutagenic effect of benzo[a]pyrene suggesting that the antimutagenic principle is present in the complex plant material itself.

  2. The Removal and Remediation of Phenanthrene and Pyrene in Soil by Mixed Cropping of Alfalfa and Rape

    Institute of Scientific and Technical Information of China (English)

    PAN Sheng-wang; WEI Shi-qiang; YUAN Xin; CAO Sheng-xian

    2008-01-01

    The mechanisms and efficiencies of the removal and remediation of polycyclic aromatic hydrocarbons (PAHs) in soils by different planting patterns with rape (Brassica campeslris) and alfalfa (Medicago sativa) were studied by pot experiments in a greenhouse. Results showed that the remediation efficiencies under mixed cropping of alfalfa and rape significantly exceeded those under single cropping when the initial concentrations of phenanthrene and pyrene were at 20.05-322.06 mg kg-1 and 20.24-321.42 mg kg-1, respectively. After 70 days plantation of crops, the contents of extractable PAHs in soils under mixed cropping were much lower than those under single cropping. About 65.17-83.52% of phenanthrene and 60.09%-75.34% of pyrene was removed from the soils under mixed cropping, respectively, which were averagely 43.26 and 40.38% for phenanthrene, and 11.03 and 16.29% for pyren higher than those under single cropping. Alfalfa or rape did absorb and accumulate PAHs from the soils apparently; the PAHs concentrations in plants monotonically increased with the increase of initial PAHs concentrations in soil; the accumulations of PAHs in plants showed following sequence as roots> above parts, phenanthrene> pyrene and single cropping> mixed cropping at same contamination level. Despite the presence of vegetation significantly enhanced the remediation of PAHs in soils, contributions of abiotic loss, plant uptake, accumulation and microbial degradation was much lower than those of plant-microbial interactions in the process of phytoremediation. Thus plant-microbial interactions are the main mechanisms for the remediation enhancement of soil PAHs pollution under mixed cropping models. Results suggested a feasibility of the establishment of multi-species phytoremediation for the improvement of remediation efficiencies of PAHs, which may decrease accumulations of PAHs in crops and thus reduce their risks.

  3. 52. INHIBITORY EFFECTS OF VITAMIN E SUCCINATE ON BENZO(A) PYRENE-INDUCED FORESTOMACH CARCINOGENESIS IN FEMALE MICE

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@This study is a part of an effort to develop effective chemoprevention for carcinogenesis of the forestomach. Vitamin E succinate(VES) administered by oral gavage and by intraperitioneal (IP) injections was used for the studies. Experimental design involved treating mice with Benzo(a) pyrene and VES(1.25 g/kg and 2.5 g/kg for gavage; 20 mg/kg for IP injections) for 4 weeks in order to study the

  4. Studies on Micellization of a Polystyrene-b-poly(acrylic acid) Copolymer in Aqueous Media by Pyrene Fluorescence

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Pyrcnc probc and TEM have been employed to investigate the behavior of a polystyrenc-b-poly(acrylic aeid) (PS-b-PAA) copolymer in aqueous solution. A significant annealing temperature effect on the I1/I3 ratio of pyrene was observed and was interpreted in terms ofthe morphological change ofmicellar cores. Anncaling at a temperature higher than the glass transition temperature (Tg) of PS leads to densification ofthe hydrophobic core.

  5. Ploidy-, gender-, and dose-dependent alteration of selected biomarkers in Clarias gariepinus treated with benzo[a]pyrene.

    Science.gov (United States)

    Karami, Ali; Teh, Swee J; Zakaria, Mohamad Pauzi; Courtenay, Simon C

    2015-12-01

    Naturally-occurring and artificially-induced polyploids have been documented in various fish species but to date no comparison has been reported of the impacts of ploidy on fish biomarker responses to organic pollutants. This study describes effects of ploidy, gender, and dose on biliary fluorescent aromatic compound (FAC) concentrations, hepatic ethoxyresorufin-O-deethylase (EROD) and glutathione S-transferase (GST) activities in one of the most commonly cultured warm-water species, the African catfish Clarias gariepinus. Recently matured male and female diploid and triploid fish were intraperitoneally (i.p.) injected with 0, 5 or 25mg/kg benzo[a]pyrene (BaP) and liver and gallbladder were sampled 48hr later. No significant differences were found between ploidies in bile concentrations of 7,8 dihydrodiolbenzo[a]pyrene (7,8D BaP), 1-hydroxybenzo[a]pyrene (1-OH BaP) or 3-hydroxybenzo[a]pyrene (3-OH BaP). However, concentrations of the biliary FACs did differ between males and females at different dose of injection with generally higher concentrations in females at the low dose of BaP and higher concentrations in males at the higher BaP concentration. Hepatic EROD activity did not exhibit gender-dependent difference, whereas it was significantly higher in triploids than diploids. GST activities were not significantly influenced by any of the tested factors. This work advanced our understanding of the role of ploidy, gender, and dose in biotransformation of pollutants in fish.

  6. Proteomic analysis of the marine diatom Thalassiosira pseudonana upon exposure to benzo(a)pyrene

    OpenAIRE

    Lettieri Teresa; Carvalho Raquel N

    2011-01-01

    Abstract Background Polycyclic aromatic hydrocarbons (PAHs) are environmental pollutants ubiquitously distributed. They are generated by incomplete combustion of organic materials such as wood or fossil fuels. Due to their carcinogenic, mutagenic effects and to their wide distribution in the environment, these pollutants pose many concerns to researchers and regulators. In our laboratories we investigated the effect of benzo(a)pyrene (BaP) exposure in the marine diatom Thalassiosira pseudonan...

  7. Degradation of metabolites of benzo[a]pyrene by coupling Penicillium chrysogenum with KMnO4

    Institute of Scientific and Technical Information of China (English)

    ZANG Shu-yan; LI Pei-jun; YU Xiao-cai; SHI Kun; ZHANG Hui; CHEN Jing

    2007-01-01

    Several main metabolites of benzo[a]pyrene (BaP) formed by Penicillium chrysogenum, Benzo[a]pyrene-l,6-quinone (BP 1,6-quinone), trans-7,8-dihydroxy-7,8-dihydrobenzo[a]pyrene (BP 7,8-diol), 3-hydroxybenzo[a]pyrene (3-OHBP), were identified by high-performance liquid chromatography (HPLC). The three metabolites were liable to be accumulated and were hardly further metabolized because of their toxicity to microorganisms. However, their further degradation was essential for the complete degradation of BaP. To enhance their degradation, two methods, degradation by coupling Penicillium chrysogenum with KMnO4 and degradation only by Penicillium chrysogenum, were compared; Meanwhile, the parameters of degradation in the superior method were optimized.The results showed that (1) the method of coupling Penicillium chrysogenum with KMnO4 was better and was the first method to be used in the degradation of BaP and its metabolites; (2) the metabolite, BP 1,6-quinone was the most liable to be accumulated in pure cultures; (3) the effect of degradation was the best when the concentration of KMnO4 in the cultures was 0.01% (w/v), concentration of the three compounds was 5 mg/L and pH was 6.2. Based on the experimental results, a novel concept with regard to the bioremediation of BaP-contaminated environment was discussed, considering the influence on environmental toxicity of the accumulated metabolites.

  8. Immobilization of pyrene on quartz plate surface via a flexible long spacer and its sensing properties to dicarboxylic acids

    Institute of Scientific and Technical Information of China (English)

    GAO Lining; FANG Yu; Lü Fengting; DING Liping

    2004-01-01

    A novel photo-induced luminescence film has been prepared by immobilizing pyrene on quartz plate surface via a flexible long spacer, 1,3-diaminopropane and 3-glycidoxypropyl trimethoxysilane. The film shows combined monomer and excimer emission of pyrene in both wet and dry states. Steady-state and time-resolved fluorescence emission measurements demonstrated that the excimer emission mainly came from direct excitation of ground state dimers, and/or monomers in aggregated state. Classical Birks' scheme plays little role in the formation of the excimers. The structures of the excimers formed during the excitation are complex. Both "standard excimer" of sandwich-like fully overlapped structure and "distorted excimer" of partially overlapped structure exist in the excited state of the fluorophore. The emission of the film is sensitive to the presence of dicarboxylic acids, including ethanedioic acid, malonic acid, succinic acid, etc. The emission in the monomer and excimer region increases along with increasing the concentration of the dicarboxylic acids. The time needed for the emission to reach equilibrium depends on the nature of the acids. It has been shown that the longer the chain length of the acids, the more the time needed. This observation is explained by considering the conformational reorganization of the immobilized pyrene due to insertion of the dicarboxylic acids into the space between neighboring spacers. Experimental results from similar studies using formic acid and acetic acid are in support of this explanation. Furthermore, the response of the film to dicarboxylic acids is reversible.

  9. Pyrene degradation and copper and zinc uptake by Fusarium solani and Hypocrea lixii isolated from petrol station soil.

    Science.gov (United States)

    Hong, J W; Park, J Y; Gadd, G M

    2010-06-01

    This study aimed to isolate and identify potential polycyclic aromatic hydrocarbon (PAH)-degrading and/or metal-tolerant fungi from PAH-contaminated and metal-contaminated soils. Pyrene-degrading fungi were isolated from contaminated soil and tested for metal (Cu, Zn and Pb) compound solubilization and metal accumulation. Three strains of Fusarium solani and one of Hypocrea lixii were able to degrade more than 60% of initial supplied pyrene (100 mg l(-1)) after 2 weeks. The isolates were grown on toxic metal (Cu, Pb and Zn)-containing media: all isolates accumulated Cu in their mycelia to values ranging from c. 5.9 to 10.4 mmol per kg dry weight biomass. The isolates were also able to accumulate Zn (c. 3.7-7.2 mmol per kg dry weight biomass) from zinc phosphate-amended media. None of the isolates accumulated Pb. These fungal isolates appear to show promise for use in bioremediation of pyrene or related xenobiotics and removal of copper and zinc from wastes contaminated singly or in combination with these substances. Microbial responses to mixed organic and inorganic pollution are seldom considered: this research highlights the abilities of certain fungal strains to interact with both xenobiotics and toxic metals and is relevant to other studies on natural attenuation and bioremediation of polluted sites.

  10. pH-driven wetting switchability of electrodeposited superhydrophobic copolymers of pyrene bearing acid functions and fluorinated chains.

    Science.gov (United States)

    Ramos Chagas, Gabriela; Kiryanenko, Denis; Godeau, Guilhem; Guittard, Frédéric; Darmanin, Thierry

    2017-08-30

    A smart stimuli responsive surface is fabricated by the subsequent electro-copolymerization of pyrene monomers followed by a basic and acid treatment, respectively. Copolymers of fluorinated pyrenes and pyreneacetic acid were produced with different molar concentration of each monomer (0, 25, 50, 75 and 100% of Py-nF6 vs. Py-COOH) by an electrochemical process. Two different perfluorinated pyrenes containing ester and amide groups are used to reach superhydrophobic properties. The relation of those bonds with the final properties of the surface is reported. The pH-sensitive group of the Py-COOH allows the surfaces to be reversibly switched from superhydrophobic (w > 150º and very low hysteresis) to a hydrophilic behavior (w superhydrophobic properties with ultra-low water adhesion, the recovery of the original wettability for the copolymers is much more important with amide bonds due to their lower pH-sensitivity. This strategy offers the opportunity to access superhydrophobic films with switchable wettability by a simple pH treatment. The films showed to be a good tool to use towards biological applications as bacterial-resistant film when superhydrophobic or bacterial-adherent film when hydrophilic, for example. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Laboratory Determination of the Infrared Band Strengths of Pyrene Frozen in Water Ice: Implications for the Composition of Interstellar Ices

    CERN Document Server

    Hardegree-Ullman, E E; Boogert, A C A; Lignell, H; Allamandola, L J; Stapelfeldt, K R; Werner, M

    2014-01-01

    Broad infrared emission features (e.g., at 3.3, 6.2, 7.7, 8.6, and 11.3 microns) from the gas phase interstellar medium have long been attributed to polycyclic aromatic hydrocarbons (PAHs). A significant portion (10%-20%) of the Milky Way's carbon reservoir is locked in PAH molecules, which makes their characterization integral to our understanding of astrochemistry. In molecular clouds and the dense envelopes and disks of young stellar objects (YSOs), PAHs are expected to be frozen in the icy mantles of dust grains where they should reveal themselves through infrared absorption. To facilitate the search for frozen interstellar PAHs, laboratory experiments were conducted to determine the positions and strengths of the bands of pyrene mixed with H2O and D2O ices. The D2O mixtures are used to measure pyrene bands that are masked by the strong bands of H2O, leading to the first laboratory determination of the band strength for the CH stretching mode of pyrene in water ice near 3.25 microns. Our infrared band str...

  12. Pyrene biodegradation in an industrial soil exposed to simulated rhizodeposition: how does it affect functional microbial abundance?

    Science.gov (United States)

    Meng, Liang; Zhu, Yong-Guan

    2011-02-15

    Rhizodeposition is an important biogeochemical process for the phytoremediation of contaminated substrates. This study investigated the effects of various rhizodeposition components from celery (Apium graveolens) on pyrene biodegradation and microbial abundance in a long-term contaminated soil. Batch microcosms simulating in situ contaminated soil were amended with lipophilic extract, water-soluble extract, or debris from celery root to mimic plant rhizodeposition within 70 days. Soil was intermittently analyzed for pyrene concentration and target gene abundance estimated by real-time PCR. Lipophilic extract was the major simulated rhizodeposit enhancing pyrene biodegradation, while water-soluble extract stimulated microbial growth most efficiently. The relative abundance of total polycyclic aromatic hydrocarbon (PAH) degraders was enhanced by lipophilic extract but inhibited by the other two rhizodeposits, indicating that these components exerted different selective pressures on PAH degrader community. Moreover, PAH catabolic pathway may involve in the pollutant detoxification and fatty acid metabolism by microorganisms, which were also affected by rhizodeposition. These results provide insights into plant-microbe interactions responsible for PAH biodegradation and offer opportunities to facilitate PAH phytoremediation in industrial sites.

  13. Selective Determination of tetrabromobisphenol A by liquid chromatography following intramolecular excimer-forming fluorescence derivatization with pyrene-labeling reagent

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, H.; Tsunetomo, S.; Todoroki, K.; Nohta, H.; Yamaguchi, M. [Fukuoka Univ. (Japan); Hayama, T. [Foundation for Kyushu Environmental and Occupational Health, Kurume (Japan); Kuroki, H. [Daiichi College of Pharmaceutical Sciences, Fukuoka (Japan)

    2004-09-15

    A large number of compounds have been used as flame-retardants to protect different products from catching fire, and one of the most widely used flameretardants is tetrabromobisphenol A (TBBPA). Trace amounts of TBBPA have been determined by gas chromatography (GC) with electron-capture detection or GC-mass spectrometry (MS) as reviewed in. Only a few liquid chromatographic (LC) methods have been reported. Recently, we developed highly selective and sensitive determination methods for polyamines and dicarboxylic acids based on intramolecular excimer-forming fluorescence derivatization using pyrene reagents. By the derivatization, the resulting polypyrene-labeled derivatives of polyamines and dicarboxylic acids provided intramolecular excimer fluorescence at the wavelength region of 440 - 520 nm, which was shifted markedly to the higher emission wavelengths as compared to the wavelengths of the pyrene reagent itself and monopyrene-labeled concomitants (360 - 420 nm). This chemistry allowed to selectively analyzing poly-functional compounds even in the complex samples containing monofunctional compounds. More recently, we have found that 4-(1-pyrene)butanoyl chloride (PBC) reacts with not only polyamines, but also phenol compounds such as bisphenols, and the obtained PBC derivatives form strong intramolecular excimers. The aim of this work was to develop an intramolecular excimer-forming derivatization method for fluorimetric determination of halogenated-bisphenols including TBBPA following their derivatization with PBC. The new method allows a highly sensitive and selective determination of tetrabromobisphenol A.

  14. Rate constants for H abstraction from benzo(a)pyrene and chrysene: a theoretical study.

    Science.gov (United States)

    Semenikhin, A S; Savchenkova, A S; Chechet, I V; Matveev, S G; Liu, Z; Frenklach, M; Mebel, A M

    2017-09-12

    Density functional B3LYP/6-31G(d) and ab initio G3(MP2,CC) calculations have been carried out to determine thermal rate constants of direct H abstraction reactions from four- and five-ring polycyclic aromatic hydrocarbons (PAH) chrysene and benzo[a]pyrene by various radicals abundant in combustion flames, such as H, CH3, C3H3, and OH, using transition state theory. The results show that the H abstraction reactions with OH have the lowest barriers of ∼4 kcal mol(-1), followed by those with H and CH3 with barriers of 16-17 kcal mol(-1), and then with propargyl radicals with barriers of 24-26 kcal mol(-1). Thus, the OH radical is predicted to be the fastest H abstractor from PAH. Even at 2500 K, the rate constant for H abstraction by H is still 34% lower than the rate constant for H abstraction by OH. The reaction with H is calculated to have rate constants 35-19 times higher than those for the reaction with CH3 due to a more favorable entropic factor. The reactions of H abstraction by C3H3 are predicted to be orders of magnitude slower than the other reactions considered and their equilibrium is strongly shifted toward the reactants, making propargyl an inefficient H abstractor from the aromatics. The calculations showed strong similarity of the reaction energetics in different H abstraction positions of benzo[a]pyrene and chrysene within armchair and zigzag edges in these molecules, but clear distinction between the armchair and zigzag sites. The zigzag sites appear to be more reactive, with H abstraction rate constants by H, CH3, and OH being respectively 37-42%, a factor of 2.1, and factors of 8-9 higher than the corresponding rate constants for the H abstraction reactions from armchair sites. Although the barrier heights for the two types of edges are similar, the entropic factor makes zigzag sites more favorable for H abstraction. Rate expressions have been generated for all studied reactions with the goal to rectify current combustion kinetics mechanisms.

  15. Transition from melting to carbonization of naphthalene, anthracene, pyrene and coronene at high pressure

    Science.gov (United States)

    Chanyshev, Artem D.; Litasov, Konstantin D.; Shatskiy, Anton F.; Sharygin, Igor S.; Higo, Yuji; Ohtani, Eiji

    2017-09-01

    We have examined the decomposition of naphthalene, anthracene, pyrene and coronene at high pressures and temperatures. Experiments were performed using in situ X-ray diffraction in multianvil apparatus at the SPring-8 synchrotron radiation facility. In the pressure range of 1.5-3.7 GPa decomposition of studied polycyclic aromatic hydrocarbons (PAHs) was detected at 773-973 K. Melting was identified only for naphthalene at 727-730 K and 1.5 GPa. Quenched products analyzed by Raman spectroscopy consist of nano- and microcrystalline graphite. The triple points between solid, liquid and carbonized (decomposed) PAHs were placed at 1-2 GPa and 800-850 K. Analyses of P-V-T data indicate that anthracene and coronene possess very low thermal expansion at 1.3-4.2 GPa. The obtained melting and decomposition parameters for PAH restrict PT-conditions of their formation by local impacts during early planetary history, as well as provide evidences for secondary origin of PAH inclusions in natural mantle minerals from kimberlites.

  16. Remediation of soil contaminated with pyrene using ground nanoscale zero-valent iron

    Energy Technology Data Exchange (ETDEWEB)

    Ming-Chin Chang; Hung-Yee Shu; Wen-Pin Hsieh; Min-Chao Wang [Hungkuang University, Taichung (China). Department of Environmental Engineering

    2007-02-15

    The sites contaminated with recalcitrant polycyclic aromatic hydrocarbons (PAHs) are serious environmental problems ubiquitously. Some PAHs have proven to be carcinogenic and hazardous. Therefore, the innovative PAH in situ remediation technologies have to be developed instantaneously. Recently, the nanoscale zero-valent iron (ZVI) particles have been successfully applied for dechlorination of organic pollutants in water, yet little research has investigated for the soil remediation so far. The objective in this work was to take advantage of nanoscale ZVI particles to remove PAHs in soil. The experimental factors such as reaction time, particle diameter and iron dosage and surface area were considered and optimized. From the results, both microscale and nanoscale ZVI were capable to remove the target compound. The higher removal efficiencies of nanoscale ZVI particles were obtained because the specific surface areas were about several dozens larger than that of commercially microscale ZVI particles. The optimal parameters were observed as 0.2 g iron/2 mL water in 60 min and 150 rpm by nanoscale ZVI. Additionally, the results proved that nanoscale ZVI particles are a promising technology for soil remediation and are encouraged in the near future environmental applications. Additionally, the empirical equation developed for pyrene removal efficiency provided the good explanation of reaction behavior. Ultimately, the calculated values by this equation were in a good agreement with the experimental data. 19 refs., 9 figs., 2 tabs.

  17. Detection of benzo[a]pyrene-induced immunotoxicity in orange spotted grouper (Epinephelus coioides).

    Science.gov (United States)

    Khaniyan, Maryam; Salamat, Negin; Safahieh, Alireza; Movahedinia, Abdolali

    2016-03-01

    This study aimed to investigate the effects of benzo[a]pyrene (BaP) on immune status of orange spotted grouper (Epinephelus coioides). Fish were injected with 2, 20 and 35 mg/kg-bw of BaP and were kept under laboratory conditions for 14 days. Blood samples were taken at days 1, 4, 7, and 14 and changes in total WBC and RBC, phagocytosis, lysozyme activity, lysosomal membrane stability, immunoglobulin M (IgM) level and antibacterial activity were evaluated. Also BaP bioaccumulation in fish muscle was measured. BaP concentration in the muscle of treated fish reached a maximum level after 4 days (P < 0.05). Exposure of fish to BaP resulted in a significant decrease of total RBC and WBC, lysozyme activity, lysosomal membrane stability, IgM level and antibacterial activity after 4 days and phagocytosis after 7 days of the experiment (P < 0.05). Totally, the results revealed BaP ability to suppress the fish immune function.

  18. Detection of the carcinogenic water pollutant benzo[a]pyrene with an electro-switchable biosurface.

    Science.gov (United States)

    Lux, Gregor; Langer, Andreas; Pschenitza, Michael; Karsunke, Xaver; Strasser, Ralf; Niessner, Reinhard; Knopp, Dietmar; Rant, Ulrich

    2015-04-21

    The toxic nature of polycyclic aromatic hydrocarbons (PAHs), in particular benzo[a]pyrene (B[a]P), neccessitates the monitoring of PAH contamination levels in food and the environment. Here we introduce an indirect immunoassay format using electro-switchable biosurfaces (ESB) for the detection of B[a]P in water. The association of anti-B[a]P antibodies to microelectrodes is analyzed in real-time by measuring changes in the oscillation dynamics of DNA nanolever probes, which are driven to switch their orientations by high-frequency electrical actuation. From the association kinetics, the active concentration of anti-B[a]P, and hence the B[a]P contamination of the sample, can be determined with picomolar sensitivity. The detection limit of the assay improves with measurement time because increasingly accurate analyses of the binding kinetics become possible. It is demonstrated that an exceedance of the permissible 10 ng/L (40 pM) limit for B[a]P is detectable in an unprecedented short assay time (deviations below 5%. Further, the utility of the assay for practical applications is exemplified by analyzing a river water sample.

  19. Dissolved organic matter conformation and its interaction with pyrene as affected by water chemistry and concentration.

    Science.gov (United States)

    Pan, Bo; Ghosh, Saikat; Xing, Baoshan

    2008-03-01

    Water chemistry and concentration of dissolved organic matter (DOM) have been reported to affect DOM conformation and binding properties with hydrophobic organic contaminants (HOCs). However, relationship between DOM conformation and its binding properties remains unclear. We designed a multibag equilibration system (MBES) to investigate the variation of carbon-normalized sorption coefficients (K(DOC)) of pyrene at different DOM concentrations based on an identical free solute concentration at different pHs and in the presence of Al ions. In addition, we studied the conformation of DOM under different conditions via atomic force microscopy (AFM) imaging, dynamic light scattering, and zeta potential measurements. Zeta potential measurements indicated that intra- and intermolecular interaction was facilitated at low pH or with the presence of Al ions, and a more organized molecular aggregate (such as a micelle-like structure) could form, thus, enhancing K(DOC). As DOM concentration increased, DOM molecular aggregation was promoted in a way reducing K(DOC). This research is a first attempt to correlate DOM conformation with K(DOC). Aggregation of DOM molecules resulting from increased zeta potential (less negative) generally led to an increased K(DOC). Further study in this area will provide valuable information on HOC-DOM interactions, thus, leading to more accurate predictions of K(DOC).

  20. Effect of rhizosphere on soil microbial community and in-situ pyrene biodegradation

    Science.gov (United States)

    Su, Y.; Yang, X.; Chiou, C.T.

    2008-01-01

    To access the influence of a vegetation on soil microorganisms toward organic pollutant biogegration, this study examined the rhizospheric effects of four plant species (sudan grass, white clover, alfalfa, and fescue) on the soil microbial community and in-situ pyrene (PYR) biodegradation. The results indicated that the spiked PYR levels in soils decreased substantially compared to the control soil without planting. With equal planted densities, the efficiencies of PYR degradation in rhizosphere with sudan grass, white clover, alfalfa and fescue were 34.0%, 28.4%, 27.7%, and 9.9%, respectively. However, on the basis of equal root biomass the efficiencies were in order of white clover >> alfalfa > sudan > fescue. The increased PYR biodegradation was attributed to the enhanced bacterial population and activity induced by plant roots in the rhizosphere. Soil microbial species and biomasses were elucidated in terms of microbial phospholipid ester-linked fatty acid (PLFA) biomarkers. The principal component analysis (PCA) revealed significant changes in PLFA pattern in planted and non-planted soils spiked with PYR. Total PLFAs in planted soils were all higher than those in non-planted soils. PLFA assemblages indicated that bacteria were the primary PYR degrading microorganisms, and that Gram-positive bacteria exhibited higher tolerance to PYR than Gram-negative bacteria did. ?? 2008 Higher Education Press and Springer-Verlag GmbH.

  1. Quercetin Attenuates Benzo(α)pyrene-induced CYP1A Expression.

    Science.gov (United States)

    Perepechaeva, M L; Seredina, T A; Sidorova, Y A; Pivovarova, E N; Markel, A L; Lyakhovich, V V; Grishanova, A Y

    2017-04-01

    We studied effects of nutrient quercetin on cytochromes' Р450 1А (CYP1A) activities (measured spectrofluorimetrically using 7-ethoxy-resorufin for CYP1A1 and 7-methoxy-resorufin for CYP1A2 as substrates), on mRNA levels (measured by RT-PCR), and on DNA-binding activities (evaluated by an electrophoretic mobility shift assay) of proteins regulating CYP1A expression in untreated and benzo(α)pyrene (BaP)-treated rats. Wistar rats received quercetin, BaP, or both once daily for 1-3 days. Quercetin did not influence CYP1A1 in untreated rats but inhibited BaP-mediated CYP1A induction on the transcriptional level decreasing positive input (AhR functional activity) and increasing negative input (AhRR/ARNT expression and Oct-1 and C/EBP functional activities). Copyright © 2017 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

  2. Mouth-Level Intake of Benzo[a]pyrene from Reduced Nicotine Cigarettes

    Directory of Open Access Journals (Sweden)

    Yan S. Ding

    2014-11-01

    Full Text Available Cigarette smoke is a known source of exposure to carcinogenic polycyclic aromatic hydrocarbons (PAHs, especially benzo[a]pyrene (BaP. Exposure to BaP in cigarette smoke is influenced by how a person smokes and factors, such as tobacco blend. To determine whether sustained use of reduced-nicotine cigarettes is associated with changes in exposure to nicotine and BaP, levels of BaP in spent cigarette filter butts were correlated with levels of BaP in cigarette smoke to estimate mouth-level intake (MLI of BaP for 72 daily smokers given three progressively reduced nicotine content cigarettes. Urinary cotinine, a marker of nicotine exposure, and urinary 1-hydroxypyrene (1-HOP, a marker of PAH exposure, were measured throughout the study. Median daily BaP MLI and urine cotinine decreased in a similar manner as smokers switched to progressively lower nicotine cigarettes, despite relatively constant daily cigarette consumption. 1-HOP levels were less responsive to the use of reduced nicotine content cigarettes. We demonstrate that spent cigarette filter butt analysis is a promising tool to estimate MLI of harmful chemicals on a per cigarette or per-day basis, which partially addresses the concerns of the temporal influence of smoking behavior or differences in cigarette design on exposure.

  3. Benzo[a]pyrene and Benzo[k]fluoranthene in Some Processed Fish and Fish Products

    Directory of Open Access Journals (Sweden)

    Olatunde S. Olatunji

    2015-01-01

    Full Text Available In this study, the concentration levels of the probable carcinogenic PAH fractions, benzo[a]pyrene (BaP and benzo[k]fluoranthrene (BkF in fillets of some processed fish species were investigated. Fish species comprising Merluccius poli (hake, Tyrsites atun (snoek, Seriola lalandi (yellow-tail and Brama brama (angel fish were bought in fish shops at Gordon’s Bay, Western Cape, South Africa. The fish were gutted, filleted and prepared for edibility by frying, grilling and boiling. Polycyclic aromatic hydrocarbons were extracted from each homogenized fish sample, cleaned-up using solid phase extraction (SPE, and analysed for the PAH fractions, BaP and BkF using a Gas Chromatograph coupled with a Flame Ionization Detector (GC-FID. The sum of the two PAHs (∑2PAH i.e., BaP and BkF ranged between 0.56 and 1.46 µg/kg, in all boiled, grilled and fried fish species. The fried fish extracts showed significantly higher (p < 0.05 abundance of ∑2PAH, than grilled and boiled fish. Dietary safety and PAHs toxicity was also discussed.

  4. Analysis of benzo[a]pyrene diolepoxide mutagenesis in a mammalian in vitro DNA replication system

    Energy Technology Data Exchange (ETDEWEB)

    Vasunia, K.; Cheng, L.; Carty, M. [Univ. of Cincinnati, OH (United States)] [and others

    1995-11-01

    Chemicals that interact with DNA and cause mutations, thereby activating protooncogenes or inactivating tumor suppressor genes, are thought to initiate the process of carcinogenesis. To elucidate the molecular mechanisms involved in mutagenesis of bulky adducts, we used an in vitro DNA replication system. An SV40-based shuttle vector, PZ189, was treated with anti-benzo[a]pyrene-7,8- dihydrodiol-9,10-epoxide (BPDE) and then replicated in vitro using hypotonic extracts of human HeLa cells. The replication efficiency was monitored by the incorporation of a radiolabelled nucleotide into DNA. The products of the replication reaction were then digested with Dpn-1 to inactivate the unreplicated plasmid and the mutation frequency was evaluated by transfection into E. coli MBM7070. Our results show that BPDE-damaged plasmids undergo replication in the in vitro system. The efficiency of replication and the mutant frequency is dose-dependent, such that the replication efficiency decreases and mutation frequency increases with increasing BPDE dose to the plasmid. This study further validates the in vitro DNA replication system by demonstrating the mutagenicity of bulky adducts of BPDE.

  5. Biodegradation of Benzo[a]pyrene by Arthrobacter oxydans B4

    Institute of Scientific and Technical Information of China (English)

    PENG Hui; YIN Hua; DENG Jun; YE Jin-Shao; CHEN Shuo-Na; HE Bao-Yan; ZHANG Na

    2012-01-01

    A bacterial strain,Arthrobacter oxydans (B4),capable of degrading benzo[a]pyrene (BaP) in water body,was isolated from a polycyclic aromatic hydrocarbons-contaminated site.Effects of different factors,such as reaction time,pH value,temperature and organic nutrients,on BaP biodegradation by the strain B4 were studied.After 5 d treatment,the concentration of BaP in mineral salts medium was reduced to 0.318 mg L-1,compared to the initial concentration of 1.000 mg L-1.There was a process of acid formation during the degradation with pH failing from initial 7.01 to 4.61 at 5 d,so keeping the water body under slightly alkaline condition was propitious to BaP degradation.Strain B4 efficiently degraded BaP at 20 to 37 ℃ with addition of organic nutrients.The biodegradation and transformation of BaP mainly occurred on cell surfaces,and extracellular secretions played an important role in these processes.Fourier transform infrared spectroscopy and gas chromatograph-mass spectrometer analyses of metabolites showed that ring cleavage occurred in the BaP degradation process and the resulting metabolically utilizable substrates were generated as sole carbon sources for B4 growth.Furthermore,mineralization extent of metabolites was verified by determining the total organic carbon and inorganic carbon in the degradation system.

  6. Protective effects of lupeol against benzo[a]pyrene induced clastogenicity in mouse bone marrow cells.

    Science.gov (United States)

    Prasad, Sahdeo; Kumar Yadav, Vinay; Srivastava, Smita; Shukla, Yogeshwer

    2008-10-01

    Fruits and vegetables contain a variety of ingredients that exhibit chemopreventive effects against an array of xenobiotics. In the present study, the antigenotoxic potential of lupeol, a triterpene, and mango pulp extract (MPE) was evaluated in Swiss albino mice. Benzo[a]pyrene (B[a]P), a well-known mutagen, was given at a single dose of 100 mg/kg body weight intraperitoneally. Pretreatment with lupeol (1 mg/animal) and MPE (1 mL, 20%) was given through oral intubation for 7 days prior to B[a]P administration. Animals from all the groups were killed at sampling time of 24 h and their bone marrow tissue was analyzed for chromosomal damage and micronuclei induction. In B[a]P-treated animals a significant induction of chromosomal aberration and micronuclei was recorded, with a decrease in mitotic index. In lupeol- or MPE-supplemented groups, a significant decrease in B[a]P-induced clastogenicity was recorded. The incidence of aberrant cells and micronuclei was found to be reduced by both lupeol and MPE when compared to the B[a]P-treated group. The anti-cytotoxic effects of lupeol or MPE were also evident, as observed by significant increase in mitotic index. Thus, results of the present investigation revealed that lupeol and MPE have protective effects against B[a]P-induced clastogenic changes in Swiss albino mice.

  7. Triple recognition of B-DNA by a neomycin-Hoechst 33258-pyrene conjugate.

    Science.gov (United States)

    Willis, Bert; Arya, Dev P

    2010-01-26

    Recent developments have indicated that aminoglycoside binding is not limited to RNA, but to nucleic acids that, like RNA, adopt conformations similar to its A-form. We further sought to expand the utility of aminoglycoside binding to B-DNA structures by conjugating neomycin, an aminoglycoside antibiotic, with the B-DNA minor groove binding ligand Hoechst 33258. Envisioning a dual groove binding mode, we have extended the potential recognition process to include a third, intercalative moiety. Similar conjugates, which vary in the number of binding moieties but maintain identical linkages to allow direct comparisons to be made, have also been prepared. We report herein novel neomycin- and Hoechst 33258-based conjugates developed in our laboratories for exploring the recognition potential with B-DNA. Spectroscopic studies such as UV melting, differential scanning calorimetry, isothermal fluorescence titrations, and circular dichroism together illustrate the triple recognition of the novel conjugate containing neomycin, Hoechst 33258, and pyrene. This study represents the first example of DNA molecular recognition capable of minor versus major groove recognition in conjunction with intercalation.

  8. Pyrene-functionalised single-walled carbon nanotubes for mediatorless dioxygen bioelectrocatalysis

    Energy Technology Data Exchange (ETDEWEB)

    Joensson-Niedziolka, Martin, E-mail: martinj@ichf.edu.p [Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw (Poland); Kaminska, Agnieszka; Opallo, Marcin [Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw (Poland)

    2010-12-01

    We have prepared electrodes for bioelectrocatalytic dioxygen reduction modified with single-walled carbon nanotubes non-covalently functionalised with 1-pyrenesulfonic acid, 1-pyrenecarboxylic acid, 1-pyrenebutyric acid or 1-pyrenemethylamine. The nanotubes were immobilised in a hydrophilic or hydrophobic silicate matrix on tin-doped indium oxide and bilirubin oxidase was either adsorbed from solution or co-immobilised with the nanotubes in the silicate matrix. In the cases where the oxidase was absorbed from solution the charge of the functionalised nanotubes was decisive for the efficiency of the bioelectrocatalytic reduction of oxygen; very low electrocatalytic current was measured with positively charged pyrene functionalisation. In the case of co-immobilised enzyme the sign of the charge of the functional group has no effect on the catalytic efficiency of the modified electrodes. Rotating disk experiments show that the main limitation of the catalytic current is the supply of oxygen to the enzyme. The PSA-functionalised SWCNT electrodes were used as a cathode in zinc-oxygen battery.

  9. Benzo[a]pyrene treatment leads to changes in nuclear protein expression and alternative splicing

    Energy Technology Data Exchange (ETDEWEB)

    Yan Chunlan; Wu Wei [Department of Toxicology, Zhejiang University School of Public Health, 388 Yu-Hang-Tang Road, Hangzhou, Zhejiang 310058 (China); Li Haiyan [Department of Toxicology, Zhejiang University School of Public Health, 388 Yu-Hang-Tang Road, Hangzhou, Zhejiang 310058 (China); Huzhou Maternity and Child Care Hospital, Huzhou, Zhejiang 313000 (China); Zhang Guanglin [Department of Toxicology, Zhejiang University School of Public Health, 388 Yu-Hang-Tang Road, Hangzhou, Zhejiang 310058 (China); Duerksen-Hughes, Penelope J. [Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA 92354 (United States); Zhu Xinqiang, E-mail: zhuxq@zju.edu.cn [Department of Toxicology, Zhejiang University School of Public Health, 388 Yu-Hang-Tang Road, Hangzhou, Zhejiang 310058 (China); Yang Jun, E-mail: gastate@zju.edu.cn [Department of Toxicology, Zhejiang University School of Public Health, 388 Yu-Hang-Tang Road, Hangzhou, Zhejiang 310058 (China); Zhejiang-California International Nanosystems Institute, Hangzhou, Zhejiang 310029 (China)

    2010-04-01

    Benzo[a]pyrene (BaP) is a potent pro-carcinogen generated from the combustion of fossil fuel and cigarette smoke. Previously, using a proteomic approach, we have shown that BaP can induce changes in the expression of many cellular proteins, including transcription regulators. In the present study, using a similar approach, we examined the nuclear protein response to BaP in HeLa cells and found that BaP treatment caused expression changes in many nuclear proteins. Twenty-four of these proteins were successfully identified, several of which are involved in the alternative splicing of mRNA, DNA replication, recombination, and repair. The changed expression levels were further confirmed by immunoblot analysis using specific antibodies for two proteins, Lamin A and mitotic checkpoint protein Bub3. The nuclear localization of these two proteins was also confirmed by confocal microscopy. To determine whether alternative splicing was activated following BaP treatment, we examined Fas and CD44, two genes previously shown to be targets of alternative splicing in respond to DNA damage. While no significant activation of alternative splicing was observed for Fas, CD44 splicing variants were found after BaP treatment. Together, these data show that DNA damage induces dramatic changes in nuclear protein expression, and that alternative splicing might be involved in the cellular response to DNA damage.

  10. Comparative Studies on the Toxicokinetics of Benzo[a]pyrene in Pinctada martensii and Perna viridis.

    Science.gov (United States)

    Wang, Haihua; Cui, Lili; Cheng, Huamin; Zhang, Yu; Diao, Xiaoping; Wang, Jun

    2017-05-01

    Research on the kinetics of Benzo[a]pyrene (B[a]P) bioaccumulation in the clam Pinctada martensii and mussel Perna viridis showed that the initial rate of uptake was directly related to the PAH concentrations in the ambient environment. The uptake and depuration rate constants were different at the four B[a]P exposure levels, which indicated that the toxicokinetic rate constants mainly depended on the exposure levels of pollutants to the environment. In addition, the uptake rate constants of B[a]P were higher than the depuration rate constants in the entire experiment. The comparison demonstrated that mussels release B[a]P more rapidly than clams. The bioconcentration factors (BCFs) of B[a]P varied from 3335 to 12892 in the clam and 2373-6235 in the mussel. These findings on the bioaccumulation kinetics for petroleum hydrocarbons, in association with the critical body residue, will be valuable when choosing sensitive organisms to assess the potential ecotoxicological risk to the marine environment.

  11. Transcriptomic responses of Perna viridis embryo to Benzo(a)pyrene exposure elucidated by RNA sequencing.

    Science.gov (United States)

    Jiang, Xiu; Qiu, Liguo; Zhao, Hongwei; Song, Qinqin; Zhou, Hailong; Han, Qian; Diao, Xiaoping

    2016-11-01

    The green mussel Perna viridis is an ideal biomonitor to evaluate marine environmental pollution. Benzo(a)pyrene (BaP) is a typical polycyclic aromatic hydrocarbon (PAH), which is well known for the mutagenic and carcinogenic characteristics. However, the toxicological effects of BaP on Perna viridis embryo are still unclear. In this study, we investigated the embryo transcriptomic profile of Perna viridis treated with BaP via digital gene expression analysis. A total of 92,362,742 reads were produced from two groups (control and BaP exposure) by whole transcriptome sequencing (RNA-Seq). Gene Ontology (GO) and Kyoto Encyclopaedia of Genes and Genomes (KEGG) pathway analysis were used on all genes to determine the biological functions and processes. Genes involved in various molecular pathways of toxicological effects were enriched further. The differential expression genes (DEGs) were related to stress response, infectious disease and innate immunity. Quantitative real-time PCR (qRT-PCR) measured expressional levels of six genes confirmed through the DGE analysis. This study reveals that RNA-seq for transcriptome profiling of P. viridis embryo can better understand the embryo toxic effects of BaP. Furthermore, it also suggests that RNA-seq is a superior tool for generating novel and valuable information for revealing the toxic effects caused by BaP at transcriptional level. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Effects of benzo(a)pyrene exposure on the antioxidant enzyme activity of scallop Chlamys farreri

    Science.gov (United States)

    Pan, Luqing; Ren, Jiayun; Zheng, Debin

    2009-02-01

    Scallop Chlamys farreri was exposed to different concentrations of benzo(a)pyrene (BaP) (0.5 μg/L, 1.0 μg/L, 10.0 μg/L and 50.0 μg/L) for 30 days in seawater. The 7-ethoxyresorufin O-deethylase (EROD) activity was significantly induced, and increased with the increasing BaP concentration. The glutathione-S-transferase (GST), superoxide dismutase (SOD), catalase (CAT), Glutathione peroxidase (GPx) activities increased in short time at low concentration of BaP, and was significantly depressed at high concentrations. Scallop gill was more sensitive to BaP than the digestive gland, and the digestive gland was the main tissue to deal with oxyradicals. The contents of malondialdehyde (MDA) increased with the exposure time and there was a positive correlation (concentration-effect) between the MDA content and the concentration of BaP. The biomarkers determined in this experiment had important roles in detoxification, and showed great potential as biomarkers for oxidative stress. Controlled laboratory experiments designed to simulate field exposure scenarios are particularly useful in ascertaining biomarkers suitable for use with complex contaminant mixtures in the marine environment.

  13. Effect of rhizosphere on soil microbial community and in-situ pyrene biodegradation

    Institute of Scientific and Technical Information of China (English)

    Yuhong SU; Xueyun YANG; Cary T CHIOU

    2008-01-01

    To access the influence of a vegetation on soil microorganisms toward organic pollutant biogegration, this study examined the rhizospheric effects of four plant species (sudan grass, white clover, alfalfa, and rescue) on the soil microbial community and in-situ pyrene (PYR) bio-degradation. The results indicated that the spiked PYR levels in soils decreased substantially compared to the con-trol soil without planting. With equal planted densities, the efficiencies of PYR degradation in rhizosphere with sudan grass, white clover, alfalfa and fescue were 34.0%, 28.4%, 27.7%, and 9.9%, respectively. However, on the basis of equal root biomass the efficiencies were in order of white clover >> alfalfa > sudan > rescue, The increased PYR biodegradation was attributed to the enhanced bacterial population and activity induced by plant roots in the rhizo-sphere. Soil microbial species and biomasses were eluci-dated in terms of microbial phospholipid ester-linked fatty acid (PLFA) biomarkers. The principal component analysis (PCA) revealed significant changes in PLFA pat-tern in planted and non-planted soils spiked with PYR. Total PLFAs in planted soils were all higher than those in non-planted soils. PLFA assemblages indicated that bac-teria were the primary PYR degrading microorganisms, and that Gram-positive bacteria exhibited higher tolerance to PYR than Gram-negative bacteria did.

  14. Synthesis of a new conjugated polymer composed of pyrene and bithiophene units for organic solar cells.

    Science.gov (United States)

    Lee, Sun-Young; Jung, Choong-Hwa; Kang, Jun; Kim, Hee-Joon; Shin, Won Suk; Yoon, Sung Cheol; Moon, Sang-Jin; Lee, Changjin; Hwang, Do-Hoon

    2011-05-01

    An alternating conjugated copolymer composed of pyrene and bithiophene units, poly(DHBT-alt-PYR) has been synthesized. The synthesized polymer was found to exhibit good solution processibility and thermal stability, losing less than 5% of their weight on heating to approximately 370 degrees C. The synthesized polymer showed its maximum absorption and peak PL emission at 401 and 548 nm, respectively. The optical band gap energy of the polymer was determined by absorption onset to be 2.64 eV. Highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels of the polymer was determined to be -5.48 and -2.84 eV by cyclic voltametry (CV) and the optical band gap. The polymer photovoltaic devices were fabricated with a typical sandwich structure of ITO/PEDOT:PSS/active layer/LiF/Al using poly(DHBT-alt-PYR) as an electron donor and C60-PCBM or C70-PCBM as electron acceptors. The open circuit voltage, short circuit current and fill factor of the device using C70-PCBM as an acceptor were 0.75 V, 3.80 mA/cm2 and 0.28, respectively, and the maximum power conversion efficiency of the device was 0.80%.

  15. INTERACTION OF BENZO(A)PYRENE DIOL EPOXIDE WITH SVAO MINICHROMOSOMES

    Energy Technology Data Exchange (ETDEWEB)

    Gamper, Howard B.; Yokota, Hisao A.; Bartholomew, James C.

    1980-03-01

    SV40 minichromosomes were reacted with (+)7{beta},8{alpha}-dihydroxy-9{alpha},10{alpha}-epoxy- 7,8,9,10-tetrahydrobenzo[a]pyrene (BaP diol epoxide). Low levels of modification (< 5 DNA adducts/minichromosome) did not detectably alter the structure of the minichromosomes but high levels (> 200 DNA adducts/minichromosome) led to extensive fragmentation. Relative to naked SV40 DNA BaP diol epoxide induced alkylation and strand scission of minichromosomal DNA was reduced or enhanced by factors of 1.5 and 2.0, respectively. The reduction in covalent binding was attributed to the presence of histones, which competed with DNA for the hydrocarbon and reduced the probability of BaP diol epoxide intercalation by tightening the helix. The enhancement of strand scission was probably due to the catalytic effect of histones on the rate of S-elimination at apurinic sites, although an altered adduct profile or the presence of a repair endonuclease were not excluded. Staphylococcal nuclease digestion indicated that BaP dial epoxide randomly alkylated the minichromosomal DNA. This is in contrast to studies with cellular chromatin where internucleosomal DNA was preferentially modified. Differences in the minichromosomal protein complement were responsible for this altered susceptibility.

  16. Anthracene and pyrene photolysis kinetics in aqueous, organic, and mixed aqueous-organic phases

    Science.gov (United States)

    Grossman, Jarod N.; Stern, Adam P.; Kirich, Makena L.; Kahan, Tara F.

    2016-03-01

    Condensed phases in the atmosphere, such as cloud droplets and aerosols, often contain both water and organic matter (OM). Reactivity can differ significantly between aqueous and organic phases. We have measured photolysis kinetics of the polycyclic aromatic hydrocarbons (PAHs) anthracene and pyrene in several organic solvents and in water, as well as in miscible and phase-separated aqueous-organic mixtures at atmospherically-relevant wavelengths. Photolysis rate constants generally increased with increasing solvent polarity; photolysis of both PAHs was more than ten times faster in water than in octanol. Local polarity had a much greater effect on PAH photolysis kinetics than changes in PAH absorptivity or singlet oxygen concentrations. Photolysis kinetics in homogeneous aqueous-organic mixtures varied monotonically with2 OM volume fraction. Kinetics in immiscible (phase-separated) solutions were more complex, with different dependences on OM content observed in stagnant and turbulent solutions. Our results suggest that OM could greatly affect the photochemical lifetimes of PAHs in atmospheric condensed phases such as aerosols, even if the OM does not itself absorb photons.

  17. Direct observation of the photodegradation of anthracene and pyrene adsorbed onto mangrove leaves.

    Directory of Open Access Journals (Sweden)

    Ping Wang

    Full Text Available An established synchronous fluorimetry method was used for in situ investigation of the photodegradation of pyrene (PYR and anthracene (ANT adsorbed onto fresh leaves of the seedlings of two mangrove species, Aegiceras corniculatum (L. Blanco (Ac and Kandelia obovata (Ko in multicomponent mixtures (mixture of the ANT and PYR. Experimental results indicated that photodegradation was the main transformation pathway for both ANT and PYR in multicomponent mixtures. The amount of the PAHs volatilizing from the leaf surfaces and entering the inner leaf tissues was negligible. Over a certain period of irradiation time, the photodegradation of both PYR and ANT adsorbed onto the leaves of Ac and Ko followed first-order kinetics, with faster rates being observed on Ac leaves. In addition, the photodegradation rate of PYR on the leaves of the mangrove species in multicomponent mixtures was much slower than that of adsorbed ANT. Compared with the PAHs adsorbed as single component, the photodegradation rate of ANT adsorbed in multicomponent mixtures was slower, while that of PYR was faster. Moreover, the photodegradation of PYR and ANT dissolved in water in multicomponent mixtures was investigated for comparison. The photodegradation rate on leaves was much slower than in water. Therefore, the physical-chemical properties of the substrate may strongly influence the photodegradation rate of adsorbed PAHs.

  18. Cucurbit[6]uril nanocavity as an enhanced spectrofluorimetric method for the determination of pyrene

    Energy Technology Data Exchange (ETDEWEB)

    Sueldo Occello, Valeria N. [Instituto de Investigaciones en Fisico Quimica de Cordoba (INFIQC), Departamento de Quimica Organica, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, Ciudad Universitaria, 5000 Cordoba (Argentina); Veglia, Alicia V., E-mail: aveglia@fcq.unc.edu.ar [Instituto de Investigaciones en Fisico Quimica de Cordoba (INFIQC), Departamento de Quimica Organica, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, Ciudad Universitaria, 5000 Cordoba (Argentina)

    2011-03-09

    The effect of the addition of macrocyclic host cucurbit[6]uril (CB6) on the photophysical properties of polycyclic aromatic hydrocarbon pyrene (PYR) was analyzed. The fluorescence emission spectra of the aromatic compound were determined at 25.0 {sup o}C in different acidic media (HCl 18%, w/v, or HCOOH 55%, w/v) with and without CB6. A significant enhancement in the fluorescence signals in the presence of CB6 was observed. The average values of the association constant (K{sub A}) for the 1:1 stoichiometry complex and the relative fluorescence quantum yield ratio between the complexed and free PYR ({phi}{sup PYR-CB6}/{phi}{sup PYR}) in acidic media were (4.0 {+-} 0.5) x 10{sup 2} M{sup -1} and (5.7 {+-} 0.2), respectively. The analytical parameters improved in the presence of CB6. The relative decrease in the limit of detection was 92%. The matrix effect was evaluated in fortified samples of tap water and tea extracts. Apparent recoveries obtained by the proposed method in tap water and tea extracts were (82-103)% and (89-99)%, respectively. Selectivity studies with inorganic and organic species were performed. The method is rapid, direct, selective and simple.

  19. Proton-transfer mediated quenching of pyrene/indole charge-transfer states in isooctane solutions.

    Science.gov (United States)

    Altamirano, Marcela S; Bohorquez, María del Valle; Previtali, Carlos M; Chesta, Carlos A

    2008-01-31

    The fluorescence quenching of pyrene (Py) by a series of N-methyl and N-H substituted indoles was studied in isooctane at 298 K. The fluorescence quenching rate constants were evaluated by mean of steady-state and time-resolved measurements. In all cases, the quenching process involves a charge-transfer (CT) mechanism. The I(o)/I and tau(o)/tau Stern-Volmer plots obtained for the N-H indoles show a very unusual upward deviation with increasing concentration of the quenchers. This behavior is attributed to the self-quenching of the CT intermediates by the free indoles in solution. The efficiency of quenching of the polyaromatic by the N-H indoles increases abruptly in the presence of small amount of added pyridine (or propanol). A detailed analysis of the experimental data obtained in the presence of pyridine provides unambiguous evidence that the self-quenching process involves proton transfer from the CT states to indoles.

  20. Photochemical behavior of benzo[a]pyrene on soil surfaces under UV light irradiation

    Institute of Scientific and Technical Information of China (English)

    ZHANG Li-hong; LI Pei-jun; GONG Zong-qiang; Oni Adeola A.

    2006-01-01

    The rates of photodegradation and photocatalysis of benzo [a]pyrene (BaP) on soil surfaces under UV light have been studied. Different parameters such as temperature, soil particle sizes, and soil depth responsible for photodegradation, catalyst loads and wavelength of UV irradiation blamed for photocatalysis have been monitored. The results obtained indicated that BaP photodegradation follows pseudo-first-order kinetics. BaP photodegradation was the fastest at 30℃. The rates of BaP photodegradation at different soil particle size followed the order: less than 1 mm>less than 0.45 mm>less than 0.25 mm. When the soil depth increased from 1 mm to 4 mm, the half-life increased from 13.23 d to 17.73 d. The additions of TiO2 or Fe2O3 accelerated the photodegradation of BaP, and the photocatalysis of BaP follows pseudo-first-order kinetics. Changes in catalyst loads of TiO2 (0.5%,1%, 2%, and 3% (wt)) or Fe2O3 (2%, 5%, 7%, and 10% (wt)) did not significantly affect the degradation rates. Both BaP photocatalysis in the presence of TiO2 and Fe2O3 were the fastest at 254 nm UV irradiation.

  1. Effects of benzo(a)pyrene exposure on the antioxidant enzyme activity of scallop Chlamys farreri

    Institute of Scientific and Technical Information of China (English)

    PAN Luqing; REN Jiayun; ZHENG Debin

    2009-01-01

    Scallop Chlamys farreri was exposed to different concentrations of benzo(a)pyrene (BaP) (0.5 μg/L, 1.0 μg/L, 10.0 μg/L and 50.0 μg/L) for 30 days in seawater. The 7-ethoxyresorufin O-deethylase (EROD) activity was significantly induced, and increased with the increasing BaP concentration. The glutathione-S-transferase (GST), superoxide dismutase (SOD), catalase (CAT), Glutathione peroxidase (GPx) activities increased in short time at low concentration of BaP, and was significantly depressed at high concentrations. Scallop gill was more sensitive to BaP than the digestive gland, and the digestive gland was the main tissue to deal with oxyradicals. The contents of malondialdehyde (MDA) increased with the exposure time and there was a positive correlation (concentration-effect) between the MDA content and the concentration of BaP. The biomarkers determined in this experiment had important roles in detoxification, and showed great potential as biomarkers for oxidative stress. Controlled laboratory experiments designed to simulate field exposure scenarios are particularly useful in ascertaining biomarkers suitable for use with complex contaminant mixtures in the marine environment.

  2. Biochemical biomarkers in Oreochromis niloticus exposed to mixtures of benzo[a]pyrene and diazinon.

    Science.gov (United States)

    Pereira Trídico, Camila; Ferreira Rodrigues, Aline Cristina; Nogueira, Lilian; da Silva, Daniele Caetano; Benedito Moreira, Altair; de Almeida, Eduardo Alves

    2010-07-01

    Biochemical biomarkers (the activities of acetylcholinesterase, 7-ethoxyresorufin-O-deetilase, carboxylesterase, catalase, glutathione peroxidase and glutathione S-transferase) were evaluated in Nile tilapia (Oreochromis niloticus) that had been exposed to benzo[a]pyrene (BaP) and the organophosphate pesticide diazinon (DZ), at 0.5mg/L. The animals were pre-exposed to BaP for three days, and DZ was then added to both non-exposed and pre-exposed groups, being exposed for 2 and 7 additional days. The level of BaP was also measured in the bile. BaP caused the induction of phase I and II enzymes, and DZ caused carboxylesterase inhibition in gills but not in liver. AChE activity was unchanged. No significant modulation was observed in antioxidant enzymes. When in combination with BaP, DZ caused a significant decrease of EROD and GST induction. Levels of BaP in the bile were also increased in fish exposed to BaP combined with DZ, indicating an interference of DZ in responses activated by BaP.

  3. Reproductive toxicity assessment of benzo[a]pyrene in the marine polychaete Perinereis nuntia

    Science.gov (United States)

    Wu, Qingyang; Wang, Shuqi; Chen, Xiaopeng; Li, Ping

    2017-07-01

    Benzo[a]pyrene (B[a]P) is an increasingly present marine environmental pollutant, yet our understanding of the long-term consequences of reproductive toxicity in marine benthic polychaetes remains limited. To test the reproductive toxicity of B[a]P on polychaetes, Perinereis nuntia was exposed to B[a]P-contaminated artificial seawater and sexual maturation, the sex ratio, number of eggs spawned, fertilization and hatching rated, as well as vitellogenin (VTG) mRNA expression levels were analyzed. A low concentration of B[a]P (2.5 μg/L) had no effects on the rate of sexual maturation, spawning, or fertilization but significantly increased the sex ratio (female: male) from 1.6±0.15:1 to 2.3±0.18:1, inhibited hatching rate by 27%, and significantly increased VTG mRNA expression level by 3.7-fold following a 60-day exposure, compared with those in the solvent controls. A higher concentration of B[a]P (25 μg/L) caused more serious effects; sexual maturation, fertilization success, and hatching decreased by 31%, 17% and 46%, respectively, and the sex ratio (female: male) and VTG mRNA gene expression level increased by 54% and 7.1-fold, respectively. These results demonstrate that sublethal concentrations of B[a]P negatively affect reproductive performance of the sandworm P. nuntia.

  4. Benzo(a)pyrene induced lung cancer: Role of dietary phytochemicals in chemoprevention.

    Science.gov (United States)

    Kasala, Eshvendar Reddy; Bodduluru, Lakshmi Narendra; Barua, Chandana C; Sriram, Chandra Shekhar; Gogoi, Ranadeep

    2015-10-01

    Lung cancer is the major cause of overall cancer deaths, and chemoprevention is a promising strategy to control this disease. Benzo(a)pyrene [B(a)P], a polycyclic aromatic hydrocarbon, is one among the principal constituents of tobacco smoke that plays a key role in lung carcinogenesis. The B(a)P induced lung cancer in mice offers a relevant model to study the effect of natural products and has been widely used by many researchers and found considerable success in ameliorating the pathophysiological changes of lung cancer. Currently available synthetic drugs that constitute the pharmacological armamentarium are themselves effective in managing the condition but not without setbacks. These hunches have accelerated the requisite for natural products, which may be used as dietary supplement to prevent the progress of lung cancer. Besides, these agents also supplement the conventional treatment and offer better management of the condition with less side effects. In the context of soaring interest toward dietary phytochemicals as newer pharmacological interventions for lung cancer, in the present review, we are attempting to give a silhouette of mechanisms of B(a)P induced lung carcinogenesis and the role of dietary phytochemicals in chemoprevention.

  5. Transcriptional signatures of regulatory and toxic responses to benzo-[a]-pyrene exposure

    Directory of Open Access Journals (Sweden)

    Schirmer Kristin

    2011-10-01

    Full Text Available Abstract Background Small molecule ligands often have multiple effects on the transcriptional program of a cell: they trigger a receptor specific response and additional, indirect responses ("side effects". Distinguishing those responses is important for understanding side effects of drugs and for elucidating molecular mechanisms of toxic chemicals. Results We explored this problem by exposing cells to the environmental contaminant benzo-[a]-pyrene (B[a]P. B[a]P exposure activates the aryl hydrocarbon receptor (Ahr and causes toxic stress resulting in transcriptional changes that are not regulated through Ahr. We sought to distinguish these two types of responses based on a time course of expression changes measured after B[a]P exposure. Using Random Forest machine learning we classified 81 primary Ahr responders and 1,308 genes regulated as side effects. Subsequent weighted clustering gave further insight into the connection between expression pattern, mode of regulation, and biological function. Finally, the accuracy of the predictions was supported through extensive experimental validation. Conclusion Using a combination of machine learning followed by extensive experimental validation, we have further expanded the known catalog of genes regulated by the environmentally sensitive transcription factor Ahr. More broadly, this study presents a strategy for distinguishing receptor-dependent responses and side effects based on expression time courses.

  6. Degradation of benzo[a]pyrene by Pleurotus ostreatus PO-3 in the presence of defined fungal and bacterial co-cultures.

    Science.gov (United States)

    Bhattacharya, Sourav; Das, Arijit; Palaniswamy, Muthusamy; Angayarkanni, Jayaraman

    2017-02-01

    Benzo[a]pyrene, a high molecular weight polycyclic aromatic hydrocarbon possesses carcinogenic, teratogenic, and mutagenic properties. The present study focuses on benzo[a]pyrene degradation by Pleurotus ostreatus PO-3, characterization and identification of metabolites produced and the extent of degradation in the presence of axenic culture of P. ostreatus PO-3 and defined co-cultures of the basidiomycete with bacteria and non-basidiomycete fungi. Thin-layer chromatography revealed that P. ostreatus PO-3 transformed benzo[a]pyrene to polar metabolites. Following degradation, appearance of numerous peaks in the mass spectrum indicated that benzo[a]pyrene degradation was a result of the metabolic activity of P. ostreatus PO-3. A degradation product corresponding to the m/z 284.2 was detected which could possibly be BaP-quinone, resulting from the oxidation of benzo[a]pyrene. Compared to the axenic culture of P. ostreatus PO-3 (64.3%), co-cultures of P. ostreatus PO-3 and Penicillium chrysogenum MTCC 787 and P. ostreatus PO-3 and Pseudomonas aeruginosa MTCC 1688 could degrade 86.1 and 75.1% of benzo[a]pyrene, respectively. Thus it could be inferred from the present investigation that the combined catabolic activities of P. ostreatus PO-3 with bacteria and non-basidiomycete fungi can produce synergistic effects to enhance BaP degradation. The increase in the generation of polar metabolites as degradation products from the recalcitrant parent compound advocates the potential application of P. ostreatus PO-3 in benzo[a]pyrene bioremediation. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. 短短芽孢杆菌降解芘的细胞毒性分析%Cytotoxicity Assay of Pyrene Biodegradation byBrevibacillus brevis

    Institute of Scientific and Technical Information of China (English)

    廖丽萍; 尹华; 刘芷辰; 叶锦韶; 彭辉; 刘则华

    2015-01-01

    近年来国内外对芘微生物降解过程中的菌种选育、降解性能和降解产物分析等相关报道较多,但针对芘降解菌与芘的分子作用机制研究却不多见。为了探明降解菌短短芽孢杆菌(Brevibacillus brevis)与芘的分子作用机制,考察了B. brevis对质量浓度为1.0 mg·L-1的芘的生物降解,分析了在无机盐培养基中B. brevis与芘作用过程中,其细胞凋亡规律及膜电位的变化,以期从细胞毒性的角度揭示PAHs的微生物降解机理。实验结果显示芘的降解率随着处理时间的增加而呈上升趋势, B. brevis对芘的降解率在168 h达到56.5%。在芘的降解过程中,细胞出现显著的凋亡现象,细胞总凋亡率与细胞早期凋亡率均在48 h时达到峰值,之后均随时间的延长而下降,168 h时细胞早期凋亡率与总凋亡率均小于0.5%,菌体依然对芘具有降解能力。随着细胞凋亡的发生,细胞膜电位下降,即细胞膜电位发生去极化现象,说明细胞外的芘与 K+共转运进入细胞内,从而有助于菌体对芘的吸收与降解。%Although there have been many reports on the isolation of pyrene degrading stains, pyrene degradation characteristics and its catabolites, the information regarding molecular mechanism between degrading bacteria and pyrene is limited thus far. To explore the molecular mechanism between degrading bacteriumBrevibacillus brevis and pyrene, the biodegradation of pyrene (1.0 mg·L-1) byB. brevis, as well as the cell apoptosis and changes of membrane potential ofB. brevis under pyrene exposure in mineral salt medium (MSM) was conducted to reveal the mechanism of pyrene biodegradation from the perspective of cytotoxicity. The experimental results showed that pyrene degradation efficiency increased with time. And the biodegradation efficiency of pyrene by B. brevis reached 56.5% after 168 h. In the degradation process, pyrene significantly induced the cell

  8. 降解菌ZQ5与紫茉莉对芘污染土壤的联合修复%Microbial-phytoremediation of pyrene contaminated soil using pyrene-degrading strain ZQ5 with Mirabilis Jalapa

    Institute of Scientific and Technical Information of China (English)

    赵媛媛; 张万坤; 马慧; 白鹏; 林景卫; 钟鸣

    2013-01-01

    在温室盆栽条件下,通过单独种植紫茉莉、单独接种多环芳烃(PAHs)模式化合物芘的专性降解菌ZQ5和两者的联合修复的3种处理,对芘污染土壤的修复效果进行了研究.结果表明,经90 d修复后,植物-微生物联合修复可将人工污染土壤中的芘降解81.1%,将石油污染土壤中的芘降解50.3%,其修复效率明显高于其他2种处理,是紫茉莉修复的1.98倍,是降解菌ZQ5修复的1.39倍.ZQ5的不同接菌量对于修复60 d后的降解率影响不大.外源生物修复条件下,10 ~ 20 cm土壤的修复效率要高于5 cm土壤;自然降解条件下,5 cm土层降解率略高于其他土层.%A pot-experiment in greenhouse was carried out to investigate the remediation efficiency of pyrene contaminated soil by planting Mirabilis Jalapa L alone,inoculating with PAHs-pyrene degrading bacteria ZQ5 strains alone and microbial-phytoremediation treatment.After 90 days,the results indicate that the microbial-phytoremediation has obvious superiority.It can remove 81.1% pyrene in the artificially contaminated soil,and 50.3% pyrene in the petroleum-contaminated soil.The microbial-phytoremediation efficiency is 1.98 times of Mirabilis Jalapa L and 1.39 times of ZQ5 strains.Different amounts of inoculating ZQ5 strains have obvious difference for initial repairment,but have little effect in the long-term repairment process.Under exogenous bioremediation conditions,the soil in depth of 10 cm to 20 cm has higher remediation efficiency than 5 cm; under natural degradation conditions,degradation rate of 5 cm depth soil is slightly higher than other soil.

  9. Polycyclic aromatic hydrocarbon (PAH) metabolizing enzyme activities in human lung, and their inducibility by exposure to naphthalene, phenanthrene, pyrene, chrysene, and benzo(a)pyrene as shown in the rat lung and liver

    Energy Technology Data Exchange (ETDEWEB)

    Elovaara, Eivor; Mikkola, Jouni; Stockmann-Juvala, Helene; Vainio, Harri [Finnish Institute of Occupational Health, Helsinki (Finland); Luukkanen, Leena [Finnish Institute of Occupational Health, Helsinki (Finland); University of Helsinki, Division of Pharmaceutical Chemistry, Faculty of Pharmacy, Helsinki (Finland); Keski-Hynnilae, Helena; Kostiainen, Risto [University of Helsinki, Division of Pharmaceutical Chemistry, Faculty of Pharmacy, Helsinki (Finland); Pasanen, Markku [University of Oulu, Department of Pharmacology and Toxicology, Oulu (Finland); University of Kuopio, Department of Pharmacology and Toxicology, Kuopio (Finland); Pelkonen, Olavi [University of Oulu, Department of Pharmacology and Toxicology, Oulu (Finland)

    2007-03-15

    In order to survey changes and activities in the polycyclic aromatic hydrocarbon (PAH)-metabolizing enzymes implicated in lung cancer susceptibility studies, we investigated enzyme induction by 2-5-ring-sized 'biomarker' PAHs in rat liver and lung, and the activities in five human lung specimens. Naphthalene, phenanthrene, pyrene, chrysene, and benzo[a]pyrene (BaP) were administered to rats for 3 days (25-128 mg/kg/day) and the responses compared with those of model inducers. PAH treatment increased the CYP1A-catalyzed activity of pyrene 1-hydroxylation and 7-ethoxyresorufin O-deethylation in rat liver by up to 28- and 279-fold, and in rat lung by up to 22- and 51-fold, respectively. 1-Naphthol (hUGT1A6), 1-hydroxypyrene (hUGT1A6/1A9), and entacapone (hUGT1A9) are markers of PAH-glucuronidating human uridine diphosphate-glucuronosyltransferases (UGT). These activities increased up to 6.4-fold in rat liver and up to 1.9-fold in rat lung. NADPH:quinone oxidoreductase 1 (NQO1) and glutathione S-transferase activities increased up to 5.3- and 1.6-fold (liver), and up to 4.4- and 1.4-fold (lung), respectively. CYP1A showed the best liver-to-lung relationship (R {sup 2} = 0.90). The inducing efficiency by PAHs differed extensively: control {<=} naphthalene < phenanthrene, pyrene << chrysene < BaP. In human lung (non-smokers), the marker activities of CYP1A1, UGT1A6/1A9, and NQO1 were lower than those in rat lung. Epoxide hydrolase activity was 1,000-fold higher than the pulmonary CYP1A1 activities. Human UGT and NQO1 displayed large variations (>60-fold), many times greater than the experimental (inducible/constitutive) variation in the rat. Kinetics of 1-hydroxypyrene glucuronidation showed two low-K{sub m} forms both in rat and human lung. Since the 2-4-ring PAHs (major constituents) were poor enzyme inducers, it appears that the PAH-metabolizing pathways are mainly induced by BaP-type minor constituents. Gene-environmental interactions which magnify

  10. Air quality assessment of benzo(a)pyrene from asphalt plant operation.

    Science.gov (United States)

    Gibson, Nigel; Stewart, Robert; Rankin, Erika

    2012-01-01

    A study has been carried out to assess the contribution of Polycyclic Aromatic Hydrocarbons (PAHs) from asphalt plant operation, utilising Benzo(a)pyrene (BaP) as a marker for PAHs, to the background air concentration around asphalt plants in the UK. The purpose behind this assessment was to determine whether the use of published BaP emission factors based on the US Environmental Protection Agency (EPA) methodology is appropriate in the context of the UK, especially as the EPA methodology does not give BaP emission factors for all activities. The study also aimed to improve the overall understanding of BaP emissions from asphalt plants in the UK, and determine whether site location and operation is likely to influence the contribution of PAHs to ambient air quality. In order to establish whether the use of US EPA emissions factors is appropriate, the study has compared the BaP emissions measured and calculated emissions rates from two UK sites with those estimated using US EPA emission factors. A dispersion modelling exercise was carried out to show the BaP contribution to ambient air around each site. This study showed that, as the US EPA methodology does not provide factors for all emission sources on asphalt plants, their use may give rise to over- or under-estimations, particularly where sources of BaP are temperature dependent. However, the contribution of both the estimated and measured BaP concentrations to environmental concentration were low, averaging about 0.05 ng m(-3) at the boundary of the sites, which is well below the UK BaP assessment threshold of 0.25 ng m(-3). Therefore, BaP concentrations, and hence PAH concentrations, from similar asphalt plant operations are unlikely to contribute negatively to ambient air quality.

  11. Protective effects of coffee against oxidative stress induced by the tobacco carcinogen benzo[α]pyrene.

    Science.gov (United States)

    Kalthoff, Sandra; Landerer, Steffen; Reich, Julia; Strassburg, Christian P

    2017-07-01

    Coffee consumption has been epidemiologically associated with a lower risk for liver cirrhosis and cancer. UDP-glucuronosyltransferases (UGT1A) catalyze the detoxification of reactive metabolites thereby acting as indirect antioxidants. Aim of the study was to examine UGT1A regulation in response to Benzo[α]pyrene (BaP) to elucidate the potentially protective effects of coffee on BaP-induced oxidative stress and toxicity. In cell culture (HepG2, KYSE70 cells) and in htgUGT1A-WT mice, UGT1A transcription was activated by BaP, while it was reduced or absent htgUGT1A-SNP (containing 10 commonly occurring UGT1A-SNPs) mice. siRNA-mediated knockdown identified aryl hydrocarbon receptor (AhR) and nuclear factor erythroid2-related factor-2 (Nrf2) as mediators of BaP-induced UGT1A upregulation. Exposure to coffee led to a reduction of BaP-induced production of reactive oxygen species in vitro and in htgUGT1A-WT and -SNP mice. After UGT1A silencing by UGT1A-specific siRNA in cell culture, the coffee-mediated reduction of ROS production was significantly impaired compared to UGT1A expressing cells. A common UGT1A haplotype, prevalent in 9% (homozygous) of the White population, significantly impairs the expression of UGT1A enzymes in response to the putative tobacco carcinogen BaP and is likely to represent a significant risk factor for reduced detoxification and increased genotoxicity. Coffee was demonstrated to inhibit BaP-induced production of oxidative stress by UGT1A activation, and is therefore an attractive candidate for chemoprotection in risk groups for HCC or other tumors. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Hypoxia diminishes the detoxification of the environmental mutagen benzo[a]pyrene.

    Science.gov (United States)

    Schults, Marten A; Sanen, Kathleen; Godschalk, Roger W; Theys, Jan; van Schooten, Frederik J; Chiu, Roland K

    2014-11-01

    Hypoxia promotes genetic instability and is therefore an important factor in carcinogenesis. We have previously shown that activation of the hypoxia responsive transcription factor HIFα can enhance the mutagenic phenotype induced by the environmental mutagen benzo[a]pyrene (BaP). To further elucidate the mechanism behind the ability of hypoxia to increase mutagenicity of carcinogens, we examined the activation and detoxification of BaP under hypoxic conditions. To this end, the human lung carcinoma cell line A549 was treated with BaP under 20%, 5% or 0.2% oxygen for 18h and alterations in BaP metabolism were assayed. First, BaP-induced expression of key metabolic enzymes was analysed; expression levels of the activating CYP1A1 and CYP1B1 were increased, while the detoxifying enzymes UGT1A6 and UGT2B7 were significantly reduced by hypoxia. To evaluate whether these changes had an effect on metabolism, levels of BaP and several of its metabolites were determined. Cells under hypoxia have a reduced capacity to metabolise BaP leaving more of the parent molecule intact. Additionally, BaP-7,8-dihydrodiol, the pre-cursor metabolite of the reactive metabolite BaP-7,8-dihydroxy-9,10-epoxide (BPDE), was formed in higher concentrations. Finally, under hypoxia, DNA adducts accumulated over a period of 168 h, whereas adducts were efficiently removed in 20% oxygen conditions. The delayed detoxification kinetics resulted in a 1.5-fold increase in DNA adducts. These data indicate that the metabolism under hypoxic conditions has shifted towards increased activation of BaP instead of detoxification and support the idea that modulation of carcinogen metabolism is an important additional mechanism for the observed HIF1 mediated genetic instability.

  13. Immunomodulatory Effect of Mangiferin in Experimental Animals with Benzo(a)Pyrene-induced Lung Carcinogenesis

    Science.gov (United States)

    Rajendran, Peramaiyan; Jayakumar, Thangavel; Nishigaki, Ikuo; Ekambaram, Ganapathy; Nishigaki, Yutaka; Vetriselvi, Jayabal; Sakthisekaran, Dhanapal

    2013-01-01

    The immunomodulatory activity of mangiferin was studied in various groups of animals. For this study, adult Swiss albino male mice were treated with benzo(a)pyrene, abbreviated as B(a)P, at 50 mg/kg body weight orally twice a week for 4 weeks; and mangiferin was also given orally (pre- and post-initiation of carcinoma) at 100 mg/kg body weight. Immunocompetence and immune complexes as measured by phagocyte index, avidity index, and soluble immune complex (SIC) levels (p<0.001), as well as NBT reduction, were decreased in the B(a)P-treated animals;whereas increased levels of immunocompetence were noted in the mangiferin-treated animals given B(a)P (p<0.001, p<0.05). The levels of immunoglobulins such as IgG and IgM were decreased considerably (p<0.001) in the B(a)P-treated animals compared with their levels in the control animals; whereas the IgA level was increased (p<0.001). In the mangiferin-treated experimental animals given B(a)P, the levels of IgG and IgM were significantly (p<0.001, p<0.05) increased whereas the IgA level was decreased compared with those for the B(a)P-treated mice. Oxidative changes in lymphocytes, neutrophils, and macrophages were also measured. The enhanced lipid peroxidation and decreased catalase and superoxide dismutase activities found in the lymphocytes, polymorphonuclear cells (PMN), and macrophages from B(a)P-treated mice were significantly reduced and increased, respectively, by the mangiferin treatment. This study confirms the immunomodulatory effect of mangiferin and shows an immunoprotective role arbitrated through a reduction in the reactive intermediate-induced oxidative stress in lymphocytes, neutrophils, and macrophages. PMID:23847456

  14. Elimination of dysfunctional mitochondria through mitophagy suppresses benzo[a]pyrene-induced apoptosis.

    Science.gov (United States)

    Das, Durgesh Nandini; Naik, Prajna Paramita; Mukhopadhyay, Subhadip; Panda, Prashanta Kumar; Sinha, Niharika; Meher, Biswa Ranjan; Bhutia, Sujit K

    2017-11-01

    Mitophagy, a special type of autophagy, plays an important role in the mitochondria quality control and cellular homeostasis. In this study, we examined the molecular mechanism of mitophagy induction with benzo[a]pyrene (B[a]P), a ubiquitous polycyclic aromatic hydrocarbon, which acts as a prosurvival response against apoptotic cell death. Our study showed that B[a]P displayed higher cytotoxicity in autophagy-deficient HaCaT cells as compared to control. Further, we showed that B[a]P triggered the Beclin-1-dependent autophagy through the mammalian target of rapamycin (mTOR)/AMP-activated protein kinase (AMPK) pathway. Moreover, our study indicated that the B[a]P-induced autophagy was initiated through the activation of cytochrome P450 1B1 (CYP1B1) and the aryl hydrocarbon receptor (AhR) in HaCaT cells. Intriguingly, the B[a]P-induced Beclin-1-mediated mitophagy was suppressed in CYP1B1 and AhR knockdown HaCaT cells, indicating a crucial role of B[a]P activation in the mitophagy induction to regulate cell death. B[a]P was shown to increase the mitochondrial dysfunction and decrease the mitochondrial membrane potential, resulting in depletion of ATP level along with the inhibition of the oxygen consumption rate in HaCaT cells. Importantly, the supplementation of methyl pyruvate compensated for the B[a]P-induced drop in the ATP level and mitigated the reactive oxygen species burden and autophagy. Mechanistically, B[a]P inhibited the manganese superoxide dismutase (MnSOD) activity and we found that the activated mitochondrial CYP1B1 interacted with MnSOD, inflicting mitophagy to protect from B[a]P-induced apoptosis. In summary, our study reveals mitophagy induction as a cellular protection mechanism against B[a]P-triggered toxicity and carcinogenesis. Copyright © 2017. Published by Elsevier Inc.

  15. Effect of benzo(a)pyrene exposure on fluoranthene metabolism by mouse adipose tissue microsomes.

    Science.gov (United States)

    Huderson, Ashley C; Harris, Deacqunita L; Niaz, Mohammad S; Ramesh, Aramandla

    2010-02-01

    The present study has been undertaken to examine whether exposure to benzo(a)pyrene (BaP), a polycyclic aromatic hydrocarbon (PAH) compound, influences the metabolism of fluoranthene (FLA), another PAH compound. Microsomes were isolated from the adipose tissue of mice that received 50 microg/kg BaP and incubated with FLA (3 microM) alone; FLA in combination with BaP at equimolar concentrations, and a control group that received nothing. Post-incubation, samples were extracted with ethyl acetate and analyzed for FLA metabolites by reverse-phase HPLC with fluorescence detection. The rate of FLA metabolism (pmol of metabolite/min/mg protein) was increased when microsomes from BaP-treated mice were exposed to FLA alone and FLA in combination with BaP, compared to controls. On the other hand, the difference in FLA metabolic rate between microsomes that were exposed to FLA + BaP was higher than the ones that received FLA. The microsomes from BaP-pre-treated mice produced a considerably higher proportion of FLA 2, 3-diol, and 2, 3 D FLA when microsomes were incubated with FLA. There were no differences in the FLA metabolite types formed when BaP-pre-treated mice were co-incubated with BaP and FLA than with FLA alone. The enhanced biotransformation of FLA as a result of prior and concomitant exposure to BaP may have implications for assessment of risks arising from human exposure to PAH mixtures.

  16. Dietary exposure estimation of benzo[a]pyrene and cancer risk assessment.

    Science.gov (United States)

    Lee, Byung Mu; Shim, Geun Ae

    2007-08-01

    Dietary benzo[a]pyrene (BaP) levels were analyzed by high-performance liquid chromatography with fluorescence detection (HPLC-FLD) in various foods (e.g., snack, potato chip, bread, vegetable oil, meat, cereal, etc.) to estimate dietary intake levels of BaP for the assessment of BaP related-cancer risk in Koreans. Higher levels of BaP were detected in fried chicken (5.25-5.55 BaP microg/kg) and smoked dried beef (5.47 microg/kg) compared to relatively lower levels measured in sesame oil (0.36 microg/kg) and peanut (0.44 microg/kg). The BaP levels in nonmeat items were generally low in detection, but certain potato chip products showed levels up to 4.06 BaP microg/kg. In terms of chronic daily intake of BaP, fried chicken was shown to be the highest (70.09 ng/person/d) and perilla oil was the lowest (0.05 ng/person/d). The total daily intake of BaP due to the consumption of various food items investigated was estimated to be 124.55 ng/person/d, based on daily food consumption and the contaminant level of BaP. The dietary BaP-related cancer risk using carcinogenic potency factor of BaP as 7.3E + 0 (mg/kg/d)(-1) was assessed to be 1.52 x 10(-5). These data suggest that cancer risk due to dietary exposure to BaP is of concern in Koreans and needs to be reduced either by regulatory efforts or by modifying food manufacturing procedures.

  17. Effect of ageing on benzo[a]pyrene extractability in contrasting soils

    Energy Technology Data Exchange (ETDEWEB)

    Duan, Luchun [CERAR-Centre for Environmental Risk Assessment and Remediation and Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), Building X, University of South Australia, Mawson Lakes, SA 5095 (Australia); Naidu, Ravi, E-mail: Ravi.Naidu@newcastle.edu.au [CERAR-Centre for Environmental Risk Assessment and Remediation and Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), Building X, University of South Australia, Mawson Lakes, SA 5095 (Australia); Liu, Yanju; Palanisami, Thavamani; Dong, Zhaomin; Mallavarapu, Megharaj [CERAR-Centre for Environmental Risk Assessment and Remediation and Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), Building X, University of South Australia, Mawson Lakes, SA 5095 (Australia); Semple, Kirk T. [Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ (United Kingdom)

    2015-10-15

    Highlights: • In vitro assessment of B[a]P in contaminated soils using 4 different methods. • An exponential kinetic model fits well with the extractability data. • Fitting parameter and {sup 14}C residue correlates with key soil properties. • Fractionation of B[a]P was obtained based on extractability by extractants. - Abstract: Changes in benzo[a]pyrene (B[a]P) extractability over 160 days ageing in four contrasting soils varying in organic matter content and clay mineralogy were investigated using dichloromethane: acetone 1:1 (DCM/Ace), 60 mM hydroxypropyl-β-cyclodextrin (HPCD) solution, 1-butanol (BuOH) and Milli-Q water. The B[a]P extractability by the four methods decreased with ageing and a first-order exponential model could be used to describe the kinetics of release. Correlation of the kinetic rate constant with major soil properties showed a significant effect of clay and sand contents and pore volume fraction (<6 nm) on sequestration of the desorbable fraction (by HPCD) and the water-extractable fraction. Analysis of {sup 14}C-B[a]P in soils after ageing showed a limited loss of B[a]P via degradation. Fractionation of B[a]P pools associated with the soil matrix was analysed according to extractability of B[a]P by the different extraction methods. A summary of the different fractions is proposed for the illustration of the effect of ageing on different B[a]P-bound fractions in soils. This study provides a better understanding of the B[a]P ageing process associated with different fractions and also emphasises the extraction capacity of the different methods employed.

  18. [Carcinogens in the urban environment of Italian cities: benzene and benzo(a)pyrenes].

    Science.gov (United States)

    Bini, G; Di Vaio, V; Liguori, E; Marini, E; Pagliai, L

    1998-01-01

    In Italian urban areas air pollution from benzene and benzo(a)pyrene-B(a)P--is mostly caused by traffic. The concentration limits in the atmosphere fixed by Italian legislation up to December 31, 1998 expressed as annual means are 15 micrograms/m3 and 2.5 ng/m3 for benzene and B(a)P respectively and, starting from January 1, 1999, 10 micrograms/m3 and 1 ng/m3. In the city of Florence the concentrations detected and expressed as annual means of benzene and B(a)P in an area with heavy traffic (32.1 micrograms/m3 and 3.5 ng/m3), in a densely populated area (9.2 micrograms/m3 and 1.86 ng/m3), and in a city park (6.0 micrograms/m3 and 0.25 ng/m3), suggest a marked progressive reduction in the atmospheric levels of these chemicals with the distance from the main roads. The environmental data obtained from densely populated areas of a number of Italian cities (Firenze, Milano, Roma, Bologna, Bolzano, Pavia, Modena), the only ones that allow evaluation of the health risk, show benzene concentrations ranging from 6.0 to 11.3 micrograms/m3 and B(a)P levels, measured in heavy traffic areas, from 1.0 to 3.5 ng/m3 respectively (annual mean in 1996). The data obtained in the city of Florence show that the population is exposed weekly to average concentrations of 14.3 micrograms/m3 for benzene and 2.0 ng/m3 for B(a)P. These results suggest that, regarding benzene and B(a)P pollution, the situation in Florence is far from being critical but not such as to ensure that long-term exposure is without adverse effects.

  19. Nuclear proteome analysis of benzo(a)pyrene-treated HeLa cells

    Energy Technology Data Exchange (ETDEWEB)

    Yan Chunlan; Chen Zhaojun; Li Huanrong; Zhang Guanglin [The First Affiliated Hospital, State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310003 (China); Department of Toxicology, Zhejiang University School of Public Health, Hangzhou, Zhejiang 310058 (China); Li Feng [The First Renmin Hospital, Houma, Shanxi 043000 (China); Duerksen-Hughes, Penelope J. [Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA 92354 (United States); Zhu Xinqiang, E-mail: zhuxq@zju.edu.cn [Department of Toxicology, Zhejiang University School of Public Health, Hangzhou, Zhejiang 310058 (China); Yang Jun, E-mail: gastate@zju.edu.cn [The First Affiliated Hospital, State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310003 (China); Department of Toxicology, Hangzhou Normal University School of Public Health, Hangzhou, Zhejiang 310036 (China)

    2012-03-01

    Previously, we employed a proteomics-based 2-D gel electrophoresis assay to show that exposure to 10 {mu}M benzo(a)pyrene (BaP) during a 24 h frame can lead to changes in nuclear protein expression and alternative splicing. To further expand our knowledge about the DNA damage response (DDR) induced by BaP, we investigated the nuclear protein expression profiles in HeLa cells treated with different concentrations of BaP (0.1, 1, and 10 {mu}M) using this proteomics-based 2-D gel electrophoresis assay. We found 125 differentially expressed proteins in BaP-treated cells compared to control cells. Among them, 79 (63.2%) were down-regulated, 46 (36.8%) were up-regulated; 8 showed changes in the 1 {mu}M and 10 {mu}M BaP-treated groups, 2 in the 0.1 {mu}M and 10 {mu}M BaP-treated groups, 4 in the 0.1 {mu}M and 1 {mu}M BaP-treated groups, and only one showed changes in all three groups. Fifty protein spots were chosen for liquid chromatography-tandem mass spectrometry (LC-MS/MS) identification, and of these, 39 were identified, including subunits of the 26S proteasome and Annexin A1. The functions of some identified proteins were further examined and the results showed that they might be involved in BaP-induced DDR. Taken together, these data indicate that proteomics is a valuable approach in the study of environmental chemical-host interactions, and the identified proteins could provide new leads for better understanding BaP-induced mutagenesis and carcinogenesis.

  20. Degradation of anthracene, pyrene and benzo[a]anthracene in aqueous solution by chlorine dioxide

    Institute of Scientific and Technical Information of China (English)

    LIU Jinquan; HUANG Junli; SU Liqiang; CAO Xiangyu; JI Ying

    2006-01-01

    Polycyclic aromatic hydrocarbons (PAHs) constitute an important group of micropollutants, which are known to be mutagenic, carcinogenic and/or co-carcinogenic and relatively persistent in the environment. The effects of chlorine dioxide (ClO2) on the degradation of anthracene (ANTH), pyrene (PYR) and benzo[a]anthracene (BaA) in aqueous solution were investigated using high performance liquid chromatography (HPLC). In preliminary experiments, it was observed that ClO2 could remove these three PAHs effectively within a short time. Several factors including reaction time, the concentration of ClO2 and pH of the reaction mixture influencing the degradation ratio of PAHs have been studied by batch experiments. The results showed that the degradation ratio of PAHs was affected by reaction time and the concentration of ClO2 instead of pH. The degradation ratio of ANTH, PYR and BaA could reach their maximum as approximately 99.0%, 67.5% and 89.5%, respectively, under the condition as follows: reaction time 30, 60 and 120 min, the concentration of ClO2 0.1, 0.4 and 0.5 mmol·L-1, and pH 7.2. ANTH was selected as the representative to study the reaction mechanism with ClO2. The oxidation products formed in the reaction of ANTH with ClO2 were tentatively identified by gas chromatography-mass spectrometry (GC-MS), and the results showed that the main product was 9, 10-anthraquinone, which could be biodegraded more easily and quickly than ANTH. Through analyzing the reaction properties of ANTH and ClO2, the possible pathway for the ANTH-ClO2 reaction was proposed based on the theory of single electron transfer (SET).

  1. Degradation of Benzo [a] Pyrene by a novel strain Bacillus subtilis BMT4i (MTCC 9447

    Directory of Open Access Journals (Sweden)

    Madhuri Kaushish Lily

    2009-12-01

    Full Text Available Benzo [a] Pyrene (BaP is a highly recalcitrant, polycyclic aromatic hydrocarbon (PAH with high genotoxicity and carcinogenicity. It is formed and released into the environment due to incomplete combustion of fossil fuel and various anthropogenic activities including cigarette smoke and automobile exhausts. The aim of present study is to isolate bacteria which can degrade BaP as a sole source of carbon and energy. We have isolated a novel strain BMT4i (MTCC 9447 of Bacillus subtilis from automobile contaminated soil using BaP (50 μg /ml as the sole source of carbon and energy in basal salt mineral (BSM medium. The growth kinetics of BMT4i was studied using CFU method which revealed that BMT4i is able to survive in BaP-BSM medium up to 40 days attaining its peak growth (10(29 fold increase in cell number on 7 days of incubation. The BaP degradation kinetics of BMT4i was studied using High Performance Liquid Chromatography (HPLC analysis of BaP biodegradation products. BMT4i started degrading BaP after 24 hours and continued up to 28 days achieving maximum degradation of approximately 84.66 %. The above findings inferred that BMT4i is a very efficient degrader of BaP. To our best of knowledge, this is the first report showing utilization of BaP as a sole source of carbon and energy by bacteria. In addition, BMT4i can degrade a wide range of PAHs including naphthalene, anthracene, and dibenzothiophene therefore, it could serve as a better candidate for bioremediation of PAHs contaminated sites.

  2. Loss of VHL in RCC reduces repair and alters cellular response to benzo[a]pyrene

    Directory of Open Access Journals (Sweden)

    Marten eSchults

    2013-10-01

    Full Text Available Mutations of the von Hippel-Lindau (VHL tumor suppressor gene occur in the majority of sporadic renal-cell carcinomas (RCC. Loss of VHL function is associated with stabilization of hypoxia-inducible factor α (HIFα. We and others demonstrated that there is a two-way interaction between the aryl hydrocarbon receptor, which is an important mediator in the metabolic activation and detoxification of carcinogens, and the HIF1-pathway leading to an increased genetic instability when both pathways are simultaneously activated. The aim of this study was to investigate how environmental carcinogens, such as benzo[a]pyrene (BaP, which can be metabolically activated to BaP-7,8-diOH-9,10-epoxide (BPDE play a role in the etiology of renal-cell carcinomas (RCC. We exposed VHL deficient RCC4 cells, in which HIFα is stabilized regardless of oxygen tension, to 0.1µM BaP for 18 hours. The mutagenic BPDE-DNA adduct levels were increased in HIFα stabilized cells. Using qRT-PCR, we demonstrated that absence of VHL significantly induced the mRNA levels of AhR downstream target CYP1A1. Furthermore, HPLC analysis indicated that loss of VHL increased the concentration of BaP-7,8-dihydroxydiol, the pre-cursor metabolite of BPDE. Interestingly, the capacity to repair BPDE-DNA adducts in the HIFα stabilized RCC4 cells, was markedly reduced. Taken together, these data indicate that loss of VHL affects BaP-mediated genotoxic responses in renal-cell carcinoma and decreases repair capacity.

  3. Pyrene biodegradation with layer-by-layer assembly bio-microcapsules.

    Science.gov (United States)

    Deng, Fucai; Zhang, Zhengfang; Yang, Chen; Guo, Chuling; Lu, Guining; Dang, Zhi

    2017-04-01

    Biotechnology is considered as a promising technology for the removal of polycyclic aromatic hydrocarbons from the environment. Free bacteria are often sensitive to some biotic and abiotic factors in the environment to the extent that their ability to effect biodegradation of organic pollutants, such as polycyclic aromatic hydrocarbons, is hampered. Consequently, it is imperative to carry out investigations into biological systems that will obviate or aid tolerance of bacteria to harsh environmental conditions. Chitosan/alginate bio-microcapsules produced using layer-by-layer (LBL) assembly method were tested for pyrene (PYR) biodegradation under harsh environmental conditions. Morphology observation indicated that the flake bio-microcapsules could be successfully prepared through LBL assembly method. Surface analysis showed that the bio-microcapsules had large fractions of mesopores. The results of the biodegradation experiments revealed that the 95% of 10mgL(-1) PYR could be removed by the bacteria encapsulated chitosan/alginate bio-microcapsules in 3 days, which was higher than that of the free bacteria (59%). Compared to the free cells, the bacteria encapsulated chitosan/alginate bio-microcapsules produced 1-6 times higher PYR biodegradation rates at a high initial PYR concentration (50mgL(-1)) and extremely low pH values (pH =3) or temperatures (10°C or 40°C), as well as high salt stress. The results indicated that bacteria in microcapsules treatment gained a much higher tolerance to environmental stress and LBL bio-microcapsule could be promising candidate for remediating the organic pollutants.

  4. Fluorogenic mercury ion sensor based on pyrene-amino mercapto thiadiazole unit.

    Science.gov (United States)

    Rani, B Kirthika; John, S Abraham

    2017-09-15

    A highly selective and sensitive determination of Hg(2+) in water samples with bioimaging applications in living cells using a fluorogenic pyrene-amino mercapto thiadiazole (PYAMT) probe is described. The probe PYAMT exhibited three absorption peaks at 333, 348 and 394nm and emission maxima at 378, 388 and 397nm (λex=348nm). It showed significant fluorescent quenching (96%) with I/I0=0.051 upon the addition of 2.5μM Hg(2+) ion in CH3CN(ACN):H2O (1:1, v/v; pH 7.2), whereas its fluorescence remained unaltered in the presence of other metal ions. The quenching phenomenon is attributed to the heavy atom effect of Hg(2+) ion followed by electron transfer. The fluorescence intensity decreased linearly against a wide range from 100nM to 2.5μM Hg(2+) (R(2)=0.9937) with a limit of detection as low as 0.35nM (S/N=3). The binding stoichiometry ratio of PYAMT-Hg(2+) is proved to be 1:1 by fluorescence and DFT measurements. The sensor possesses high association constant with Hg(2+) ion in the order of 9.08×10(5)M(-1) and it is also capable of reversibly detecting cysteine with OFF-ON mechanism. Finally, the proposed method is successfully applied to selectively detect Hg(2+) ion in real water samples and bioimaging studies in live cells. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Luminescence of ferrocene-modified pyrene derivatives for turn-on sensing of Cu2 + and anions

    Science.gov (United States)

    Sun, Shuhua; Hu, Wenting; Gao, Hongfang; Qi, Honglan; Ding, Liping

    2017-09-01

    Detection and identification of metal ions by fluorescent turn-on sensors are challenging due to the quenching effect of most of the tested metal ions. In the present work, three ferrocene-modified pyrene-based probes 2-4 were synthesized to act as turn-on fluorescent sensors for Cu2 +. The measurements of fluorescence quantum yield and fluorescence lifetime reveal that ferrocenyl unit can efficiently reduce the fluorescence emission of pyrene moiety. Steady-state fluorescence measurements find that the three ferrocene-modified fluorophores exhibit selective turn-on responses to Cu2 +. Moreover, this turn-on effect to Cu2 + is highly influenced by the type of the counter ion. It is found that the presence of Cl- or NO3- could realize the turn-on response to Cu2 +, whereas, the presence of SO42 - or Ac- could not induce any fluorescence enhancement to Cu2 +. Control experiments with ferrocene-free pyrene-based probe 1 reveal that the ferrocenyl unit plays the key role in the turn-on response to Cu2 +. The possible mechanism for the turn-on responses is attributed to the oxidation behavior of Cu2 + to the ferrocene unit, which is confirmed by the control experiments with sodium ascorbate. Cyclic voltammetry measurements show that Cu2 + can influence the redox behaviors of ferrocenyl derivatives, which is also highly dependent on the anion of the copper salts. The influence of anion on the turn-on responses to Cu2 + was further used for anion detection and fluorescent logic gate.

  6. Effects of the antibiotic ciprofloxacin on the bacterial community structure and degradation of pyrene in marine sediment

    Energy Technology Data Exchange (ETDEWEB)

    Naeslund, Johan [Department of Systems Ecology, Stockholm University, 106 91 Stockholm (Sweden)], E-mail: johan@ecology.su.se; Hedman, Jenny E.; Agestrand, Cecilia [Department of Systems Ecology, Stockholm University, 106 91 Stockholm (Sweden)

    2008-11-21

    The ecological consequences of antibiotics in the aquatic environment have been an issue of concern over the past years due to the potential risk for negative effects on indigenous microorganisms. Microorganisms provide important ecosystem services, such as nutrient recycling, organic matter mineralization and degradation of pollutants. In this study, effects of exposure to the antibiotic ciprofloxacin on the bacterial diversity and pollutant degradation in natural marine sediments were studied using molecular methods (T-RFLP) in combination with radiorespirometry. In a microcosm experiment, sediment spiked with {sup 14}C-labelled pyrene was exposed to five concentrations of ciprofloxacin (0, 20, 200, 1000 and 2000 {mu}g L{sup -1}) in a single dose to the overlying water. The production of {sup 14}CO{sub 2} (i.e. complete mineralization of pyrene) was measured during 11 weeks. Sediment samples for bacterial community structure analysis were taken after 7 weeks. Results showed a significant dose-dependent inhibition of pyrene mineralization measured as the total {sup 14}CO{sub 2} production. The nominal EC{sub 50} was calculated to 560 {mu}g L{sup -1}, corresponding to 0.4 {mu}g/kg d.w. sediment. The lowest effect concentration on the bacterial community structure was 200 {mu}g L{sup -1}, which corresponds to 0.1 {mu}g/kg d.w. sediment. Our results show that antibiotic pollution can be a potential threat to both bacterial diversity and an essential ecosystem service they perform in marine sediment.

  7. Laboratory determination of the infrared band strengths of pyrene frozen in water ice: Implications for the composition of interstellar ices

    Energy Technology Data Exchange (ETDEWEB)

    Hardegree-Ullman, E. E. [New York Center for Astrobiology and Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY 12180 (United States); Gudipati, M. S.; Werner, M. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Boogert, A. C. A. [Infrared Processing and Analysis Center, Mail Code 100-22, California Institute of Technology, Pasadena, CA 91125 (United States); Lignell, H. [Department of Chemistry, University of California Irvine, Irvine, CA 92697-2025 (United States); Allamandola, L. J. [Space Science Division, Mail Stop 245-6, NASA Ames Research Center, Moffett Field, CA 94035 (United States); Stapelfeldt, K. R., E-mail: hardee@rpi.edu, E-mail: gudipati@jpl.nasa.gov [NASA Goddard Space Flight Center, Exoplanets and Stellar Astrophysics Laboratory, Code 667, Greenbelt, MD 20771 (United States)

    2014-04-01

    Broad infrared emission features (e.g., at 3.3, 6.2, 7.7, 8.6, and 11.3 μm) from the gas phase interstellar medium have long been attributed to polycyclic aromatic hydrocarbons (PAHs). A significant portion (10%-20%) of the Milky Way's carbon reservoir is locked in PAH molecules, which makes their characterization integral to our understanding of astrochemistry. In molecular clouds and the dense envelopes and disks of young stellar objects (YSOs), PAHs are expected to be frozen in the icy mantles of dust grains where they should reveal themselves through infrared absorption. To facilitate the search for frozen interstellar PAHs, laboratory experiments were conducted to determine the positions and strengths of the bands of pyrene mixed with H{sub 2}O and D{sub 2}O ices. The D{sub 2}O mixtures are used to measure pyrene bands that are masked by the strong bands of H{sub 2}O, leading to the first laboratory determination of the band strength for the CH stretching mode of pyrene in water ice near 3.25 μm. Our infrared band strengths were normalized to experimentally determined ultraviolet band strengths, and we find that they are generally ∼50% larger than those reported by Bouwman et al. based on theoretical strengths. These improved band strengths were used to reexamine YSO spectra published by Boogert et al. to estimate the contribution of frozen PAHs to absorption in the 5-8 μm spectral region, taking into account the strength of the 3.25 μm CH stretching mode. It is found that frozen neutral PAHs contain 5%-9% of the cosmic carbon budget and account for 2%-9% of the unidentified absorption in the 5-8 μm region.

  8. Two nitro derivatives of azabenzo[a]pyrene N-oxide: Electronic properties and their relation to mutagenic activity

    Energy Technology Data Exchange (ETDEWEB)

    Ostojić, Bojana D., E-mail: bostojic@chem.bg.ac.rs; Đorđević, Dragana S.

    2015-03-21

    Highlights: • Molecular properties of nitro isomers of azabenzo[a]pyrene N-oxide are investigated. • Stability, ionization potential, electron affinity, and polarizability are determined. • High quality DFT methods are employed. • Nitroreduction, oxidation, and polarizability are not crucial for mutagenicity. • Dipole moment and electronic charge distribution are important for characterization. - Abstract: The equilibrium geometries, relative energies, IR and Raman spectra, vertical ionization potentials (IP), vertical electron affinities (EA), dipole moments (μ), electronic dipole polarizabilities (α), and molecular electrostatic potentials (MEP) of two species that show very high mutagenicity, 1-nitro-6-azabenzo[a]pyrene N-oxide (1-N-6-ABPO) and 3-nitro-6-azabenzo[a]pyrene N-oxide (3-N-6-ABPO), are investigated by means of Density Functional Theory (DFT) using B3LYP functional with different basis sets. The 3-N-6-ABPO isomer was estimated to be much more mutagenic in Salmonella typhimurium tester strain TA98 (396 000 revertants/nmol) than 1-N-6-ABPO (36 100 revertants/nmol) (Fukuhara et al., 1992). The results show that for both isomers the structural, energetic, and vibrational properties are similar. The orientation of the nitro group with respect to the plane of the aromatic system as well as the nitroreduction and oxidation reaction and polarizability seem not be important for the determination of different mutagenic behavior of these isomers. However, the dipole moment of 3-N-6-ABPO is about 3 times that of 1-N-6-ABPO. The larger dipole moment and the different electronic charge distribution of 3-N-6-ABPO compared to 1-N-6-ABPO imply stronger electrostatic and inductive molecular interactions so that the active site of the enzyme involved in the mutagenic activation can more effectively bind 3-N-6-ABPO compared to 1-N-6-ABPO.

  9. Synthesis, Spectral Characterization of Several Novel Pyrene-Derived Aminophosphonates and Their Ecotoxicological Evaluation Using Heterocypris incongruens and Vibrio fisheri Tests

    Directory of Open Access Journals (Sweden)

    Jarosław Lewkowski

    2016-07-01

    Full Text Available Four diphenyl pyrene-derived aminophosphonates were synthesized. Attempts were made to synthesize diphenyl N-(R-α-methylbenzylamino(pyren-1-ylmethylphosphonate (3e in order to obtain the chiral aminophosphonate bearing a pyrene moiety. Because these attempts failed, dimethyl and dibenzyl N-(R-α-methylbenzyl substituted aminophosphonates 4 and 5 were synthesized and the predominant diastereoisomer of dimethyl aminophosphonate 4 was isolated. The resolution of the diastereomeric mixture of 5 failed. Aminophosphonates 3a–d and the predominant diastereoisomer of 4 were investigated in terms of their ecotoxicity using tests performed on the ostracode Heterocypris incongruens and the fluorescent bacterium Vibrio fisheri. The tests confirmed the moderate-to-high ecotoxicity of aminophosphonates 3a–d and 4, but no evident correlation between the structure and toxicity has been found.

  10. Toxicity, feeding rate and growth rate response to sub-lethal concentrations of anthracene and benzo [a] pyrene in milkfish Chanos chanos (Forskkal).

    Science.gov (United States)

    Palanikumar, L; Kumaraguru, A K; Ramakritinan, C M; Anand, M

    2013-01-01

    The feeding rate, growth rate and gross conversion efficiency were studied in milkfish Chanos chanos for 28 days of exposure to sub-lethal concentrations of anthracene (1.00, 2.00, 3.00, 6.00 and 12.0 μg l(-1)) and benzo [a] pyrene (0.30, 0.70, 1.40, 2.80 and 5.60 μg l(-1)) under continuous flow through bioassays. Based on survival and growth data, No Observed Effect Concentration; Lowest Observed Effect Concentration were estimated after 28 days, the values for anthracene were 2.03 and 3.09 μg l(-1), and the values for benzo [a] pyrene were 0.82 and 1.46 μg l(-1), respectively. Anthracene and benzo [a] pyrene exposure caused reduction in feeding and growth rate.

  11. Degradation of benzo[a]pyrene in an experimentally contaminated paddy soil by vetiver grass (Vetiveria zizanioides).

    Science.gov (United States)

    Li, H; Luo, Y M; Song, J; Wu, L H; Christie, P

    2006-01-01

    A pot experiment was conducted to study the effect of growing vetiver grass on the biodegradation of benzo[a]pyrene (B[a]P) under glasshouse conditions. Plant biomass, microbial biomass C and degradation of B[a]P were determined. B[a]P disappeared faster in the plant treatments than in unplanted controls. Disappearance of B[a]P was accompanied by an increase in soil microbial biomass C. Vetiver grass may promote the biodegradation of B[a]P under flooded conditions by plant roots by stimulating the microbial biomass. Microbial biomass was the main factor affecting dissipation of B[a]P under flooded conditions.

  12. Role of viscosity in the magnetic field effect on pyrene-DMA exciplex emission at different permittivities

    Science.gov (United States)

    Jana, Amit Kumar; Roy, Partha; Nath, Deb Narayan

    2014-02-01

    Effect of viscosity variation on the magnetic field effect in pyrene-N,N-dimethylaniline exciplex luminescence has been studied at different permittivity values. The data is compatible to the model of Krissinel et al. (1999) [10] reported earlier to explain the effect probing the escape yield of radical pairs. It is shown that the data can also be explained on the basis of a simple model. It is interesting to note that the present letter also demonstrates the positive slope of MFE with diffusivity at extremely high viscous condition as predicted by Krissinel et al. (1999) [10] which has not been observed in earlier experiments.

  13. Edge-Functionalization of Pyrene as a Miniature Graphene via Friedel–Crafts Acylation Reaction in Poly(Phosphoric Acid

    Directory of Open Access Journals (Sweden)

    Jeon In-Yup

    2010-01-01

    Full Text Available Abstract The feasibility of edge-functionalization of graphite was tested via the model reaction between pyrene and 4-(2,4,6-trimethylphenyloxybenzamide (TMPBA in poly(phosphoric acid (PPA/phosphorous pentoxide (P2O5 medium. The functionalization was confirmed by various characterization techniques. On the basis of the model study, the reaction condition could be extended to the edge-functionalization of graphite with TMPBA. Preliminary results showed that the resultant TMPBA-grafted graphite (graphite-g-TMPBA was found to be readily dispersible in N-methyl-2-pyrrolidone (NMP and can be used as a precursor for edge-functionalized graphene (EFG.

  14. Efficient small molecule bulk heterojunction solar cells with high fill factors via pyrene-directed molecular self-assembly

    KAUST Repository

    Lee, Olivia P.

    2011-10-21

    Efficient organic photovoltaic (OPV) materials are constructed by attaching completely planar, symmetric end-groups to donor-acceptor electroactive small molecules. Appending C2-pyrene as the small molecule end-group to a diketopyrrolopyrrole core leads to materials with a tight, aligned crystal packing and favorable morphology dictated by π-π interactions, resulting in high power conversion efficiencies and high fill factors. The use of end-groups to direct molecular self-assembly is an effective strategy for designing high-performance small molecule OPV devices. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Use of Physiologically-Based Pharmacokinetic Modeling to Simulate the Profiles of 3-Hydroxybenzo(a)pyrene in Workers Exposed to Polycyclic Aromatic Hydrocarbons

    OpenAIRE

    Roberto Heredia Ortiz; Anne Maître; Damien Barbeau; Michel Lafontaine; Michèle Bouchard

    2014-01-01

    Biomathematical modeling has become an important tool to assess xenobiotic exposure in humans. In the present study, we have used a human physiologically-based pharmacokinetic (PBPK) model and an simple compartmental toxicokinetic model of benzo(a)pyrene (BaP) kinetics and its 3-hydroxybenzo(a)pyrene (3-OHBaP) metabolite to reproduce the time-course of this biomarker of exposure in the urine of industrially exposed workers and in turn predict the most plausible exposure scenarios. The models ...

  16. The discovery of half-sandwich iridium complexes containing lidocaine and (pyren-1-yl)ethynyl derivatives of phenylcyanamide ligands for photodynamic therapy.

    Science.gov (United States)

    Tabrizi, Leila

    2017-06-06

    The successful design, synthesis, characterization, photophysical properties and anticancer mechanistic studies of a series of half-sandwich cyclopentadienyl iridium(iii) complexes of the type [Cp*Ir(III)(LC)(L1)](PF6), 1, and [Cp*Ir(III)(LC)(L2)](PF6), 2, in which Cp* = pentamethylcyclopentadienyl, L1 = 4-(pyren-10-yl)ethynyl-phenylcyanamide, L2 = 4'-(pyren-10-yl)ethynyl-4-cyanamidobiphenyl, and LC = lidocaine, are reported for their application as photodynamic therapy (PDT) agents. The DNA binding, DNA photocleavage, cellular uptake, and apoptosis of the complexes have also been studied.

  17. Protective effect of curcumin and chlorophyllin against DNA mutation induced by cyclophosphamide or benzo[a]pyrene

    Energy Technology Data Exchange (ETDEWEB)

    Ibrahim, M.A.; Elbehairy, A.M.; Ghoneim, M.A.; Amer, H.A. [Cairo Univ., Giza (Egypt). Biochemistry Dept. and Biotechnology Center

    2007-03-15

    The current study was carried out to evaluate the potency of curcumin and chlorophyllin as natural antioxidants to reduce the oxidative stress markers induced by cyclophosphamide (CP) and benzo[a]pyrene [B(a)P] which were used as free radical inducers. For this purpose, 126 male albino rats were used. The animals were assigned into 4 main groups: negative control group; oxidant-treated group (subdivided into two subgroups: cyclophosphamide- treated group and benzo[a]pyrene-treated group); curcumin-treated group; and chlorophyllin-treated group. Liver samples were collected after two days post the oxidant inoculation and at the end of the experimental period (10 weeks). These samples were examined for determination of liver microsomal malondialdehyde (MDA), DNA fragmentation, restriction fragment length polymorphism (RFLP) and 8-hydroxy deoxyguanosine (8-OHdG) concentration. Both CP and B(a)P caused increments in DNA fragmentation percentages, liver microsomal MDA, concentration of 8-OHdG and induced point mutation. Treatment of rats with either curcumin or chlorophyllin revealed lower DNA fragmentation percentages, liver microsomal MDA concentration, concentration of 8-OHdG and prevented induction of mutations, i. e., reversed the oxidative stress induced by CP and B(a)P and proved that they were capable of protecting rats against the oxidative damage evoked by these oxidants. (orig.)

  18. Protective effect of curcumin and chlorophyllin against DNA mutation induced by cyclophosphamide or benzo[a]pyrene.

    Science.gov (United States)

    Ibrahim, Marwa A; Elbehairy, Adel M; Ghoneim, Magdy A; Amer, Hassan A

    2007-01-01

    The current study was carried out to evaluate the potency of curcumin and chlorophyllin as natural antioxidants to reduce the oxidative stress markers induced by cyclophosphamide (CP) and benzo[a]pyrene [B(a)P] which were used as free radical inducers. For this purpose, 126 male albino rats were used. The animals were assigned into 4 main groups: negative control group; oxidant-treated group (subdivided into two subgroups: cyclophosphamide-treated group and benzo[a]pyrene-treated group); curcumin-treated group; and chlorophyllin-treated group. Liver samples were collected after two days post the oxidant inoculation and at the end of the experimental period (10 weeks). These samples were examined for determination of liver microsomal malondialdehyde (MDA), DNA fragmentation, restriction fragment length polymorphism (RFLP) and 8-hydroxy deoxyguanosine (8-OHdG) concentration. Both CP and B(a)P caused increments in DNA fragmentation percentages, liver microsomal MDA, concentration of 8-OHdG and induced point mutation. Treatment of rats with either curcumin or chlorophyllin revealed lower DNA fragmentation percentages, liver microsomal MDA concentration, concentration of 8-OHdG and prevented induction of mutations, i.e., reversed the oxidative stress induced by CP and B(a)P and proved that they were capable of protecting rats against the oxidative damage evoked by these oxidants.

  19. Anthracene and benzo(a)pyrene degradation in soil is favoured by compost amendment: Perspectives for a bioremediation approach.

    Science.gov (United States)

    Baldantoni, Daniela; Morelli, Raffaella; Bellino, Alessandro; Prati, Maria Vittoria; Alfani, Anna; De Nicola, Flavia

    2017-10-05

    In order to validate the use of compost in soil PAH bioremediation, the degradation of anthracene and benzo(a)pyrene was monitored in soils artificially contaminated and incubated in mesocosms under controlled conditions. The dynamics observed in compost amended soil were compared to those observed in soil added with a fungal consortium and untreated soil. At the same time, three microbial enzyme activities usually involved in PAH degradation (laccase, o-diphenol oxidase and peroxidase activities) were monitored. Both PAHs decreased along the time in the three mesocosms, with anthracene, with lower molecular weight, degrading with a higher rate and reaching lower residual values than benzo(a)pyrene. Although at the end of incubation, the residual values of investigated PAHs are similar in the three mesocosm types, PAH dynamics showed a higher degradation rate in the early stage in mesocosms added with the fungal mycelium and amended with compost. Among the three enzyme activities, only peroxidase showed higher values in treated than untreated mesocosms. Considering the ameliorating effects of compost on degraded soils, its use can be suggested in PAH bioremediation. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. The genotoxic effects of benzo[a]pyrene and methamidophos on black porgy evaluated by comet assay

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    In this study, two common pollutants (benzo[a]pyrene and methamidophos) in marine environment were tested by comet assay for their inducement of in vivo genotoxic effect to the blood cells of black porgy (Acanthopagrus schlegeli). The fish was exposed to 2 μg/L of benzo[a]pyrene (BaP) and methamidophos, and their mixture. The assay was performed on whole blood at 2 h, 5 h, 24 h and 96 h exposure intervals. A significant increase in DNA damage was observed in each treatment with the pollutants. Additive effect of BaP and methamidophos was also found in the experiment. However, the decrease ratios of DNA damage for 5 h and 96 h exposure interals compared with 2 h and 24 h exposure ones, respectively, were noticed. This phenomenon may be explained by the function of repairing process via enzyme cytochrome P450 in the animal. Evidence of the genotoxicity of organophosphorus pesticides (OPs) and polynuclear aromatic hydrocarbons (PAHs) on marine fish are discussed in this paper.

  1. The genotoxic effects of benzo[a]pyrene and methamidophos on black porgy evaluated by comet assay

    Science.gov (United States)

    Liu, Rixian; Hong, Huasheng; Wang, Xinhong; Wang, Kejian; Wang, Chunguang

    2005-12-01

    In this study, two common pollutants (benzo[a]pyrene and methamidophos) in marine environment were tested by comet assay for their inducement of in vivo genotoxic effect to the blood cells of black porgy ( Acanthopagrus schlegeli). The fish was exposed to 2 μg/L of benzo[a]pyrene (BaP) and methamidophos, and their mixture. The assay was performed on whole blood at 2 h, 5 h, 24 h and 96 h exposure intervals. A significant increase in DNA damage was observed in each treatment with the pollutants. Additive effect of BaP and methamidophos was also found in the experiment. However, the decrease ratios of DNA damage for 5 h and 96 h exposure interals compared with 2 h and 24 h exposure ones, respectively, were noticed. This phenomenon may be explained by the function of repairing process via enzyme cytochrome P450 in the animal. Evidence of the genotoxicity of organophosphorus pesticides (OPs) and polynuclear aromatic hydrocarbons (PAHs) on marine fish are discussed in this paper.

  2. Enhancing plant-microbe associated bioremediation of phenanthrene and pyrene contaminated soil by SDBS-Tween 80 mixed surfactants.

    Science.gov (United States)

    Ni, Hewei; Zhou, Wenjun; Zhu, Lizhong

    2014-05-01

    The use of surfactants to enhance plant-microbe associated dissipation in soils contaminated with polycyclic aromatic hydrocarbons (PAHs) is a promising bioremediation technology. This comparative study was conducted on the effects of plant-microbe treatment on the removal of phenanthrene and pyrene from contaminated soil, in the presence of low concentration single anionic, nonionic and anionic-nonionic mixed surfactants. Sodium dodecyl benzene sulfonate (SDBS) and Tween 80 were chosen as representative anionic and nonionic surfactants, respectively. We found that mixed surfactants with concentrations less than 150 mg/kg were more effective in promoting plant-microbe associated bioremediation than the same amount of single surfactants. Only about (m/m) of mixed surfactants was needed to remove the same amount of phenanthrene and pyrene from either the planted or unplanted soils, when compared to Tween 80. Mixed surfactants (Tween 80. These results may be explained by the lower sorption loss and reduced interfacial tension of mixed surfactants relative to Tween 80, which enhanced the bioavailability of PAHs in soil and the microbial degradation efficiency. The higher remediation efficiency of low dosage SDBS-Tween 80 mixed surfactants thus advanced the technology of surfactant-enhanced plant-microbe associated bioremediation.

  3. Effect of chimneys on indoor air concentrations of PM 10 and benzo[a]pyrene in Xuan Wei, China

    Science.gov (United States)

    Tian, Linwei; Lan, Qing; Yang, Dong; He, Xingzhou; Yu, Ignatius T. S.; Hammond, S. Katharine

    This paper reports the effect of chimneys in reducing indoor air pollution in a lung cancer epidemic area of rural China. Household indoor air pollution concentrations were measured during unvented burning (chimneys blocked) and vented burning (chimneys open) of bituminous coal in Xuan Wei, China. Concentrations of particulate matter with an aerodynamic diameter of 10 μm or less (PM 10) and of benzo[a]pyrene (BaP) were measured in 43 homes during normal activities. The use of chimneys led to significant decreases in indoor air concentrations of particulate matter with an aerodynamic diameter of 10 μm or less (PM 10) by 66% and of benzo[a]pyrene (BaP) by 84%. The average BaP content of PM 10 also decreased by 55% with the installation of a chimney. The reduction of indoor pollution levels by the installation of a chimney supports the epidemiology findings on the health benefits of stove improvement. However, even in the presence of a chimney, the indoor air concentrations for both PM 10 and BaP still exceeded the indoor air quality standards of China. Movement up the energy ladder to cleaner liquid or gaseous fuels is probably the only sustainable indoor air pollution control measure.

  4. Photocatalytic degradation of polycyclic aromatic hydrocarbon benzo[a]pyrene by iron oxides and identification of degradation products.

    Science.gov (United States)

    Gupta, Himanshu; Gupta, Bina

    2015-11-01

    Photocatalytic decay profiles of polycyclic aromatic hydrocarbon (PAH) benzo[a]pyrene (B[a]P) have been investigated on various synthesized iron oxides and on soil surfaces under a set of diverse conditions. Samples were analysed using the developed HPLC procedure. Results of the present study demonstrate fastest photodisintegration of B[a]P on goethite followed by haematite, magnetite, akaganeite and maghemite, respectively. The effect of soil pH, irradiation wavelength and iron oxide and oxalic acid dose on the degradation of B[a]P was evaluated. The studies revealed enhancement in photodegradation in the presence of oxalic acid due to the occurrence of fenton like reaction. The results showed faster B[a]P degradation under short wavelength UV radiation. Rate constants in acidic, neutral and alkaline soils under optimum dissipation conditions were 1.11×10(-2), 7.69×10(-3) and 9.97×10(-3) h(-1), respectively. The study indicates that iron oxides along with oxalic acid are effective photocatalyst for the remediation of benzo[a]pyrene contaminated soil surfaces. The degradation products of B[a]P in the soils of different pH in presence of goethite were identified and degradation pathways proposed. Peaks due to toxic metabolites such as diones, diols and epoxides disappear after 120 h in all the three soils.

  5. Two nitro derivatives of azabenzo[a]pyrene N-oxide: electronic properties and their relation to mutagenic activity.

    Science.gov (United States)

    Ostojić, Bojana D; Đorđević, Dragana S

    2015-03-21

    The equilibrium geometries, relative energies, IR and Raman spectra, vertical ionization potentials (IP), vertical electron affinities (EA), dipole moments (μ), electronic dipole polarizabilities (α), and molecular electrostatic potentials (MEP) of two species that show very high mutagenicity, 1-nitro-6-azabenzo[a]pyrene N-oxide (1-N-6-ABPO) and 3-nitro-6-azabenzo[a]pyrene N-oxide (3-N-6-ABPO), are investigated by means of Density Functional Theory (DFT) using B3LYP functional with different basis sets. The 3-N-6-ABPO isomer was estimated to be much more mutagenic in Salmonella typhimurium tester strain TA98 (396,000 revertants/nmol) than 1-N-6-ABPO (36100 revertants/nmol) (Fukuhara et al., 1992). The results show that for both isomers the structural, energetic, and vibrational properties are similar. The orientation of the nitro group with respect to the plane of the aromatic system as well as the nitroreduction and oxidation reaction and polarizability seem not be important for the determination of different mutagenic behavior of these isomers. However, the dipole moment of 3-N-6-ABPO is about 3 times that of 1-N-6-ABPO. The larger dipole moment and the different electronic charge distribution of 3-N-6-ABPO compared to 1-N-6-ABPO imply stronger electrostatic and inductive molecular interactions so that the active site of the enzyme involved in the mutagenic activation can more effectively bind 3-N-6-ABPO compared to 1-N-6-ABPO.

  6. Designs, Synthesis, Characterization and Direct Electrochem- istry of Zinc-Porphyrin Bearing Pyrene Noncovalent Functionalized Graphene Oxide Sheet

    Institute of Scientific and Technical Information of China (English)

    毕纯; 李永捷; 陈浩文; 尹桂; 朱俊杰

    2012-01-01

    We have designed and synthesis a new compound of zinc-porphyrin bearing four pyrene groups (ZnP-t-P(py)4) and prepared a new hybrid materials of ZnP-t-P(py)4 with graphene oxide (GO) via non-covalent interactions. The ZnP-t-P(py)4, along with four pendant pyrene entities ZnP-t-P(py)4, stacking on the (GO) surface due to n-~ interac- tions, has been revealed by AFM measurements. FTIR, UV-vis absorption confirm the non-covalent functionaliza- tion of the GO. Raman spectral measurements revealed the electronic structure of the GO to be intact upon hybrid formation. In this donor-acceptor nanohybrid, the fluorescence ofphotoexcited ZnP-t-P(py)4 is effectively quenched by a possible electron-transfer process. The fluorescence and photoelectrical response measurements also showed that this hybrid may act as an efficient photoelectric conversion material for optoelectronic applications.

  7. Effect of chimneys on indoor air concentrations of PM10 and benzo(a)pyrene in Xuan Wei, China

    Energy Technology Data Exchange (ETDEWEB)

    Tian, L.W.; Lan, Q.; Yang, D.; He, X.Z.; Yu, I.T.S.; Hammond, S.K. [Chinese University of Hong Kong, Hong Kong (China). School for Public Health

    2009-07-15

    This paper reports the effect of chimneys in reducing indoor air pollution in a lung cancer epidemic area of rural China. Household indoor air pollution concentrations were measured during unvented burning (chimneys blocked) and vented burning (chimneys open) of bituminous coal in Xuan Wei, China. Concentrations of particulate matter with an aerodynamic diameter of 10 {mu} m or less (PM10) and of benzo(a)pyrene (BaP) were measured in 43 homes during normal activities. The use of chimneys led to significant decreases in indoor air concentrations of particulate matter with an aerodynamic diameter of 10 mu m or less (PM10) by 66% and of benzo(a)pyrene (BaP) by 84%. The average BaP content of PM10 also decreased by 55% with the installation of a chimney. The reduction of indoor pollution levels by the installation of a chimney supports the epidemiology findings on the health benefits of stove improvement. However, even in the presence of a chimney, the indoor air concentrations for both PM10 and BaP still exceeded the indoor air quality standards of China. Movement up the energy ladder to cleaner liquid or gaseous fuels is probably the only sustainable indoor air pollution control measure.

  8. A common carcinogen benzo[a]pyrene causes neuronal death in mouse via microglial activation.

    Directory of Open Access Journals (Sweden)

    Kallol Dutta

    Full Text Available BACKGROUND: Benzo[a]pyrene (B[a]P belongs to a class of polycyclic aromatic hydrocarbons that serve as micropollutants in the environment. B[a]P has been reported as a probable carcinogen in humans. Exposure to B[a]P can take place by ingestion of contaminated (especially grilled, roasted or smoked food or water, or inhalation of polluted air. There are reports available that also suggests neurotoxicity as a result of B[a]P exposure, but the exact mechanism of action is unknown. METHODOLOGY/PRINCIPAL FINDINGS: Using neuroblastoma cell line and primary cortical neuron culture, we demonstrated that B[a]P has no direct neurotoxic effect. We utilized both in vivo and in vitro systems to demonstrate that B[a]P causes microglial activation. Using microglial cell line and primary microglial culture, we showed for the first time that B[a]P administration results in elevation of reactive oxygen species within the microglia thereby causing depression of antioxidant protein levels; enhanced expression of inducible nitric oxide synthase, that results in increased production of NO from the cells. Synthesis and secretion of proinflammatory cytokines were also elevated within the microglia, possibly via the p38MAP kinase pathway. All these factors contributed to bystander death of neurons, in vitro. When administered to animals, B[a]P was found to cause microglial activation and astrogliosis in the brain with subsequent increase in proinflammatory cytokine levels. CONCLUSIONS/SIGNIFICANCE: Contrary to earlier published reports we found that B[a]P has no direct neurotoxic activity. However, it kills neurons in a bystander mechanism by activating the immune cells of the brain viz the microglia. For the first time, we have provided conclusive evidence regarding the mechanism by which the micropollutant B[a]P may actually cause damage to the central nervous system. In today's perspective, where rising pollution levels globally are a matter of grave concern, our

  9. Modulatory effects of Azadirachta indica on benzo(a)pyrene-induced forestomach tumorigenesis in mice

    Institute of Scientific and Technical Information of China (English)

    Subhash Chander Gangar; Rajat Sandhir; Durg Vijay Rai; Ashwani Koul

    2006-01-01

    AIM: To evaluate the chemopreventive effects of aqueous Azadirachta indica (A indica) leaf extract (AAILE)against benzo(a)pyrene [B(a)P]-induced forestomach tumorigenesis in Balb/c mice.METHODS: Female Balb/c mice were divided into four groups of 10-12 animals each. For induction of forestomach tumors, starting from d 14 of the experiment, mice of B(a)P and B(a)P+A indica groups were given intra-gastric instillations of B(a)P (40 mg/kg), twice a week for four weeks. Mice of A indica and B(a)P+A indica groups were orally administered with AAILE (100mg/kg), two weeks prior to B(a)P instillations till the end of the experiment. After 22 wk of the first B(a)P instillation, mice were sacrificed and the forestomachs were analyzed for development of tumors, scanning electron microscopy (SEM) and histopathology.RESULTS: Tumor incidence was observed to be 100%in mice that received only B(a)P. However, treatment with AAILE reduced the tumor incidence by 58.4%as observed in mice of B(a)P+A indica group when compared to that of B(a)P group. Similarly, the tumor burden and multiplicity were seen to decrease by 87.3% and 69.6% respectively in mice of B(a)P+A indica group when compared to those of B(a)P group.Scanning electron microscopy analysis showed that AAILE treatment itself did not cause any abnormalities on the surface architecture of forestomach epithelium.In tumorous forestomach, surface disruption was observed. Over the forestomach tumors of B(a)P group of mice certain rounded structures were seen in addition to closely placed tongue-shaped squamous cells. Interestingly, these rounded structures were not observed in B(a)P + A indica group of mice.Histopathalogically, the tumors were identical and diagnosed to be papillomas. Mice from control and A indica groups of mice did not develop any forestomach tumors and showed normal histo-architecture.CONCLUSION: The present data suggest that A indica exerts chemopreventive effects against B(a)P-induced forestomach tumors in

  10. Influence of cell cycle on responses of MCF-7 cells to benzo[a]pyrene

    Directory of Open Access Journals (Sweden)

    Giddings Ian

    2011-06-01

    Full Text Available Abstract Background Benzo[a]pyrene (BaP is a widespread environmental genotoxic carcinogen that damages DNA by forming adducts. This damage along with activation of the aryl hydrocarbon receptor (AHR induces complex transcriptional responses in cells. To investigate whether human cells are more susceptible to BaP in a particular phase of the cell cycle, synchronised breast carcinoma MCF-7 cells were exposed to BaP. Cell cycle progression was analysed by flow cytometry, DNA adduct formation was assessed by 32P-postlabeling analysis, microarrays of 44K human genome-wide oligos and RT-PCR were used to detect gene expression (mRNA changes and Western blotting was performed to determine the expression of some proteins, including cytochrome P450 (CYP 1A1 and CYP1B1, which are involved in BaP metabolism. Results Following BaP exposure, cells evaded G1 arrest and accumulated in S-phase. Higher levels of DNA damage occurred in S- and G2/M- compared with G0/G1-enriched cultures. Genes that were found to have altered expression included those involved in xenobiotic metabolism, apoptosis, cell cycle regulation and DNA repair. Gene ontology and pathway analysis showed the involvement of various signalling pathways in response to BaP exposure, such as the Catenin/Wnt pathway in G1, the ERK pathway in G1 and S, the Nrf2 pathway in S and G2/M and the Akt pathway in G2/M. An important finding was that higher levels of DNA damage in S- and G2/M-enriched cultures correlated with higher levels of CYP1A1 and CYP1B1 mRNA and proteins. Moreover, exposure of synchronised MCF-7 cells to BaP-7,8-diol-9,10-epoxide (BPDE, the ultimate carcinogenic metabolite of BaP, did not result in significant changes in DNA adduct levels at different phases of the cell cycle. Conclusions This study characterised the complex gene response to BaP in MCF-7 cells and revealed a strong correlation between the varying efficiency of BaP metabolism and DNA damage in different phases of the cell

  11. Using gridded multimedia model to simulate spatial fate of Benzo[α]pyrene on regional scale.

    Science.gov (United States)

    Liu, Shijie; Lu, Yonglong; Wang, Tieyu; Xie, Shuangwei; Jones, Kevin C; Sweetman, Andrew J

    2014-02-01

    Predicting the environmental multimedia fate is an essential step in the process of assessing the human exposure and health impacts of chemicals released into the environment. Multimedia fate models have been widely applied to calculate the fate and distribution of chemicals in the environment, which can serve as input to a human exposure model. In this study, a grid based multimedia fugacity model at regional scale was developed together with a case study modeling the fate and transfer of Benzo[α]pyrene (BaP) in Bohai coastal region, China. Based on the estimated emission and in-site survey in 2008, the BaP concentrations in air, vegetation, soil, fresh water, fresh water sediment and coastal water as well as the transfer fluxes were derived under the steady-state assumption. The model results were validated through comparison between the measured and modeled concentrations of BaP. The model results indicated that the predicted concentrations of BaP in air, fresh water, soil and sediment generally agreed with field observations. Model predictions suggest that soil was the dominant sink of BaP in terrestrial systems. Flow from air to soil, vegetation and costal water were three major pathways of BaP inter-media transport processes. Most of the BaP entering the sea was transferred by air flow, which was also the crucial driving force in the spatial distribution processes of BaP. The Yellow River, Liaohe River and Daliao River played an important role in the spatial transformation processes of BaP. Compared with advection outflow, degradation was more important in removal processes of BaP. Sensitivities of the model estimates to input parameters were tested. The result showed that emission rates, compartment dimensions, transport velocity and degradation rates of BaP were the most influential parameters for the model output. Monte Carlo simulation was carried out to determine parameter uncertainty, from which the coefficients of variation for the estimated Ba

  12. Overexpression of Catalase Enhances Benzo(a)pyrene Detoxification in Endothelial Microsomes

    Science.gov (United States)

    Yang, Fang; Yang, Hong; Ramesh, Aramandla; Goodwin, J. Shawn; Okoro, Emmanuel U.; Guo, ZhongMao

    2016-01-01

    We previously reported that overexpression of catalase upregulated xenobiotic- metabolizing enzyme (XME) expression and diminished benzo(a)pyrene (BaP) intermediate accumulation in mouse aortic endothelial cells (MAECs). Endoplasmic reticulum (ER) is the most active organelle involved in BaP metabolism. To examine the involvement of ER in catalase-induced BaP detoxification, we compared the level and distribution of XMEs, and the profile of BaP intermediates in the microsomes of wild-type and catalase transgenic endothelial cells. Our data showed that endothelial microsomes were enriched in cytochrome P450 (CYP) 1A1, CYP1B1 and epoxide hydrolase 1 (EH1), and contained considerable levels of NAD(P)H: quinone oxidoreductase-1 (NQO1) and glutathione S-transferase-pi (GSTP). Treatment of wild-type MAECs with 1μM BaP for 2 h increased the expression of microsomal CYP1A1, 1B1 and NQO1 by ~300, 64 and 116%, respectively. However, the same treatment did not significantly alter the expression of EH1 and GSTP. Overexpression of catalase did not significantly increase EH1, but upregulated BaP-induced expression of microsomal CYP1A1, 1B1, NQO1 and GSTP in the following order: 1A1>NQO1>GSTP>1B1. Overexpression of catalase did not alter the distribution of each of these enzymes in the microsomes. In contrast to our previous report showing lower level of BaP phenols versus BaP diols/diones in the whole-cell, this report demonstrated that the sum of microsomal BaP phenolic metabolites were ~60% greater than that of the BaP diols/diones after exposure of microsomes to BaP. Overexpression of catalase reduced the concentrations of microsomal BaP phenols and diols/diones by ~45 and 95%, respectively. This process enhanced the ratio of BaP phenol versus diol/dione metabolites in a potent manner. Taken together, upregulation of phase II XMEs and CYP1 proteins, but not EH1 in the ER might be the mechanism by which overexpression of catalase reduces the levels of all the BaP metabolites

  13. Metabolism of the environmental toxicant benzo(a)pyrene by subcellular fractions of human ovary.

    Science.gov (United States)

    Rekhadevi, P V; Diggs, D L; Huderson, A C; Harris, K L; Archibong, A E; Ramesh, A

    2014-02-01

    Knowledge of the ability of the female reproductive system to metabolize environmental chemicals is critical not only from the standpoint of toxicity but also from infertility risk assessment. Benzo(a)pyrene (BaP) is a toxicant that is released into the environment from automobile exhausts, cigarette smoke, burning of refuse, industrial emissions, and hazardous waste sites. In exposed animals, BaP becomes activated to reactive metabolites that interfere with target organ function and as a consequence cause toxicity. Studies on animal models conducted in our laboratories and those of others have shown that BaP possess endocrine disrupting properties. Thus, this chemical has the potential to cause infertility and cancers in the female genital tract. An understanding of BaP metabolism in the female reproductive system will be of importance in the diagnosis and management of female fertility as well as cancers in the reproductive tissues. Therefore, the objective of our study was to examine the metabolism of BaP by human ovarian subcellular fractions. Human ovary samples (eight individuals) were obtained from postoperative tissue removed from subjects with uterine tumors. Subcellular fractions (nuclear, cytosolic, mitochondrial, and microsomal) were prepared by differential centrifugation. BaP (1 μM and 3 μM) was individually incubated with individual subcellular fractions for 15 min and the products were analyzed by high-performance liquid chromatography. Among the different fractions tested, microsomal BaP metabolism was higher than the rest of the fractions. The BaP metabolites identified were as follows: BaP-9,10-diol, BaP-4,5-diol, BaP-7,8-diol, 9(OH) BaP, 3(OH) BaP, BaP-1,6-dione, BaP-3,6-dione, and BaP-6,12-dione. Of interest was the presence of DNA-reactive metabolites such as BaP-3,6-dione, BaP-6,12-dione, and BaP 7,8-diol, which have been implicated in the causation of infertility and cancer. Our results indicate that women who are exposed to BaP via

  14. REACTIONS OF BENZO[A]PYRENE-7,8-QUINONE WITH DEOXYGUANOSINE AND DEOXYADENOSINE AT PHYSIOLOGICAL pH: IDENTIFICATION AND CHARACTERIZATION OF STABLE ADDUCTS

    Science.gov (United States)

    Reactions of Benzo[a]pyrene-7,8-quinone with Deoxyguanosine and Deoxyadenosine at Physiological pH: Identification and Characterization of Stable AdductsNarayanan Balu, William T. Padgett, Guy Lambert, Adam E. Swank,Ann M. Richard, and Stephen NesnowEnvironmen...

  15. Protective effects of green tea polyphenols against benzo[a]pyrene-induced reproductive and trans-generational toxic effects in Japanese Medaka (Oryzias latipes)

    NARCIS (Netherlands)

    Song, Chuankui; Wang, Yanli; Xiao, Zhengcao; Xiao, Bin

    2015-01-01

    In order to investigate the protective effect of green tea polyphenols (GTP) on benzo[a]pyrene (BaP)-induced reproductive and trans-generational toxicity, Japanese Medaka was injected intraperitoneally with BaP alone and co-injected with both BaP and GTP of different concentrations, respectively.

  16. Effects of the invasive polychaete, Marenzelleria viridis, on the fate of sediment associated pollutants – a microcosm study with 14C-labelled pyrene

    DEFF Research Database (Denmark)

    Banta, Gary Thomas; Hedman, Jenny Elisabet

    on the fate of deeply buried sediment-associated pollutants in the historically polluted Baltic Sea. We report here the results of an experimental microcosm study examining the fate of 14C radiolabelled pyrene (a 4-ring PAH) in sediment microcosms with and without Marenzelleria viridis. We also investigated...

  17. Effects of fatty acids on benzo[a]pyrene uptake and metabolism in human lung adenocarcinoma A549 cells.

    Directory of Open Access Journals (Sweden)

    Rola Barhoumi

    Full Text Available Dietary supplementation with natural chemoprotective agents is receiving considerable attention because of health benefits and lack of toxicity. In recent in vivo and in vitro experimental studies, diets rich in n-3 polyunsaturated fatty acids have been shown to provide significant anti-tumor action. In this investigation, the effects of control fatty acids (oleic acid (OA, linoleic acid (LA and n-3 PUFA, e.g., docosahexaenoic acid (DHA on the uptake and metabolism of the carcinogenic polycyclic aromatic hydrocarbon, benzo[a]pyrene (BaP was investigated in A549 cells, a human adenocarcinoma alveolar basal epithelial cell line. A549 cells activate BaP through the cytochrome P450 enzyme system to form reactive metabolites, a few of which covalently bind to DNA and proteins. Therefore, multiphoton microscopy spectral analysis combined with linear unmixing was used to identify the parent compound and BaP metabolites formed in cells, in the presence and absence of fatty acids. The relative abundance of select metabolites was associated with altered P450 activity as determined using ethoxyresorufin-O-deethylase activity in cells cultured in the presence of BSA-conjugated fatty acids. In addition, the parent compound within cellular membranes increases significantly in the presence of each of the fatty acids, with the greatest accumulation observed following DHA treatment. DHA treated cells exhibit significantly lower pyrene-like metabolites indicative of lower adducts including DNA adducts compared to control BSA, OA or LA treated cells. Further, DHA reduced the abundance of the proximate carcinogen BaP 7,8-dihydrodiol and the 3-hydroxybenzo[a]pyrene metabolites compared to other treatments. The significant changes in BaP metabolites in DHA treated cells may be mediated by the effects on the physicochemical properties of the membrane known to affect enzyme activity related to phase I and phase II metabolism. In summary, DHA is a highly bioactive chemo

  18. Monitoring the effect of pyrene on the germination and radial growth of the wild and mutant strains of Rhizopus arrhizus UCP402

    Directory of Open Access Journals (Sweden)

    Ricardo Kenji Shiosaki

    2008-06-01

    Full Text Available The physiological mutant of Rhizopus arrhizus was obtained in the pyrene resistance gradient test. Comparative studies were carried out about the behavior of the germination process and the radial growth of the mutant and wild strains of R. arrhizus UCP 402. Sabouraud Sucrose and Yeast Malt Broth cultures containing pyrene (10 mg/L induced the germination process of the sporangiospores of the wild and mutant strains of R. arrhizus. The radial growth of the strains was inversely proportional to the pyrene concentration in the culture medium. The results showed an adaptation of R. arrhizus UCP 402x (mutant in the pyrene (50mg/L and suggested a higher ability of application in the removal of pyrene from the contaminated areas.O mutante fisiológico de Rhizopus arrhizus foi obtido pelo teste do gradiente de resistência ao pireno. Estudos comparativos conduzidos sobre o comportamento do processo de germinação e o crescimento radial foram realizados entre as amostras selvagem e mutante de R. arrhizus UCP 402. Os meios Sabouraud Sacarose e Caldo de Levedura e Malte contendo pireno (10 mg/L induziram ao processo de germinação de esporangiosporos das amostras selvagem e mutante de R. arrhizus. O crescimento radial das amostras foi inversamente proporcional à concentração de pireno no meio de cultura. Os resultados demonstraram uma excelente adaptação da amostra mutante de R. arrhizus UCP 402x na concentração de pireno (50 mg/L, sugerindo uma alta habilidade e possibilidade de aplicação na remoção de pireno em áreas contaminadas.

  19. Structural insight into DNA-assembled oligochromophores: crystallographic analysis of pyrene- and phenanthrene-modified DNA in complex with BpuJI endonuclease.

    Science.gov (United States)

    Probst, Markus; Aeschimann, Walter; Chau, Thi T H; Langenegger, Simon M; Stocker, Achim; Häner, Robert

    2016-09-06

    The use of the DNA duplex as a supramolecular scaffold is an established approach for the assembly of chromophore aggregates. In the absence of detailed structural insight, the characterization of thus assembled oligochromophores is, today, largely based on solution-phase spectroscopy. Here, we describe the crystal structures of three DNA-organized chromophore aggregates. DNA hybrids containing non-nucleosidic pyrene and phenanthrene building blocks were co-crystallized with the recently described binding domain of the restriction enzyme BpuJI. Crystal structures of these complexes were determined at 2.7, 1.9 and 1.6 Å resolutions. The structures reveal aromatic stacking interactions between pyrene and/or phenanthrene units within the framework of the B-DNA duplex. In hybrids containing a single modification in each DNA strand near the end of the duplex, the two polyaromatic hydrocarbons are engaged in a face-to-face stacking orientation. Due to crystal packing and steric effects, the terminal GC base pair is disrupted in all three crystal structures, which results in a non-perfect stacking arrangement of the aromatic chromophores in two of the structures. In a hybrid containing a total of three pyrenes, crystal lattice induced end-to-end stacking of individual DNA duplexes leads to the formation of an extended aromatic π-stack containing four co-axially arranged pyrenes. The aromatic planes of the stacked pyrenes are oriented in a parallel way. The study demonstrates the value of co-crystallization of chemically modified DNA with the recombinant binding domain of the restriction enzyme BpuJI for obtaining detailed structural insight into DNA-assembled oligochromophores.

  20. Benzo[a]pyrene contamination in Rostov Region of Russian Federation: A 10-year retrospective of soil monitoring under the effect of long-term technogenic pollution

    Directory of Open Access Journals (Sweden)

    Svetlana Sushkova

    2016-04-01

    Full Text Available The aim of the current work was to study the main tendencies in the accumulation and distribution of benzo[a]pyrene in soils of the affected zone of the Novocherkassk regional power plant. Studies were conducted on the soils of monitoring plots subjected to Novocherkassk regional power plant emissions. Monitoring plots were established at different distances from the Novocherkassk regional power plant (1.0–20.0 km. Regularities in the accumulation and distribution of benzo[a]pyrene in chernozemic, meadow-chernozemic, and alluvial soils under the effect of aerotechnogenic emissions from the Novocherkassk regional power plant have been revealed on the basis of long-term monitoring studies (from 2002 to 2011. The tendencies in the distribution and accumulation of BaP in the studied soils coincided during the 10 years of monitoring studies. It has been found the 5-km zone to the northwest from the power station, which coincides with the predominant wind direction, is most subjected to contamination by benzo[a]pyrene, with the maximum accumulation at a distance of about 1.6 km from the source. Dynamics of pollutant accumulation in soils depends on number of Novocherkassk regional power plant emissions. The content of benzo[a]pyrene in the soil is an indicator of the technogenic load impact on the areas, for which the combustion products of hydrocarbon fuel are the major pollutants. A gradual decrease of the pollutant content in the soils was revealed during the period from 2002 to 2011. It explained by the significant decrease in the volume of pollutant emissions from the plant and the self-purification capacity of soils and mechanisms of benzo[a]pyrene degradation.

  1. Linking embryo toxicity with genotoxic responses in the freshwater snail Physa acuta: single exposure to benzo(a)pyrene, fluoxetine, bisphenol A, vinclozolin and exposure to binary mixtures with benzo(a)pyrene.

    Science.gov (United States)

    Sánchez-Argüello, Paloma; Aparicio, Natalia; Fernández, Carlos

    2012-06-01

    Genotoxic effects on fauna after waterborne pollutant exposure have been demonstrated by numerous research programmes. Less effort has been focused on establishing relationship between genotoxicity and long-term responses at higher levels of biological organization. Taking into account that embryos may be more sensitive indicators of reproductive impairment than alterations in fertility, we have developed two assays in multiwell plates to address correlations between embryo toxicity and genotoxicity. The potential teratogenicity was assessed by analyzing abnormal development and mortality of Physa acuta at embryonic stage. Genotoxicity was measured by the micronucleus (MN) test using embryonic cells. Our results showed that linkage between genotoxicity and embryo toxicity depends on mechanisms of action of compounds under study. Embryo toxic responses showed a clear dose-related tendency whereas no clear dose-dependent effect was observed in micronucleus induction. The higher embryo toxicity was produced by benzo(a)pyrene exposure followed by fluoxetine and bisphenol A. Vinclozolin was the lower embryo toxic compound. Binary mixtures with BaP always resulted in higher embryo toxicity than single exposures but antagonistic effects were observed for MN induction. Benzo(a)pyrene produced the higher MN induction at 0.04 mg/L, which also produced clear embryo toxic effects. Fluoxetine did not induce cytogenetic effects but 0.25mg/L altered embryonic development. Bisphenol A significantly reduced hatchability at 0.5mg/L while MN induction appeared with higher treatments than those that start causing teratogenicity. Much higher concentration of vinclozolin (5mg/L) reduced hatchability and induced maximum MN formation. In conclusion, while validating one biomarker of genotoxicity and employing one ecologically relevant effect, we have evaluated the relative sensitivity of a freshwater mollusc for a range of chemicals. The embryo toxicity test is a starting point for the

  2. Benzo(a)pyrene accumulation in soils of technogenic emission zone by subcritical water extraction method

    Science.gov (United States)

    Sushkova, Svetlana; Minkina, Tatiana; Kizilkaya, Ridvan; Mandzhieva, Saglara; Batukaev, Abdulmalik; Bauer, Tatiana; Gulser, Coskun

    2016-04-01

    The purpose of research is the assessment of main marker of polycyclic aromatic hydrocarbons contamination, benzo[a]pyrene (BaP) content in soils of emission zone of the power complex plant in soils with use of ecologically clean and effective subcritical water extraction method. Studies were conducted on the soils of monitoring plots subjected to Novocherkassk Power Plant emissions from burning coal. In 2000, monitoring plots were established at different distances from the NPS (1.0-20.0 km). Soil samples for the determination of soil properties and the contents of BaP were taken from a depth of 0-20 cm. The soil cover in the region under study consisted of ordinary chernozems, meadow-chernozemic soils, and alluvial meadow soils. This soil revealed the following physical and chemical properties: Corg-3.1-5.0%, pH-7.3-7.6, ECE-31.2-47.6 mmol(+)/100g; CaCO3-0.2-1.0%, the content of physical clay - 51-67% and clay - 3-37%. BaP extraction from soils was carried out by a subcritical water extraction method. Subcritical water extraction of BaP from soil samples was conducted in a specially developed extraction cartridge made of stainless steel and equipped with screw-on caps at both ends. It was also equipped with a manometer that included a valve for pressure release to maintain an internal pressure of 100 atm. The extraction cartridge containing a sample and water was placed into an oven connected to a temperature regulator under temperature 250oC and pressure 60 atm. The BaP concentration in the acetonitrile extract was determined by HPLC. The efficiency of BaP extraction from soil was determined using a matrix spike. The main accumulation of pollutant in 20 cm layer of soils is noted directly in affected zone on the plots situated at 1.2, 1.6, 5.0, 8.0 km from emission source in the direction of prevailing winds. The maximum quantity of a pollutant was founded in the soil of the plot located mostly close to a source of pollution in the direction of prevailing winds

  3. Cytochrome P450 1B1, a novel chemopreventive target for benzo[a]pyrene-initiated human esophageal cancer.

    Science.gov (United States)

    Wen, Xia; Walle, Thomas

    2007-02-08

    Esophageal cancer is common worldwide, with poor prognosis. Smoking, including exposure to polyaromatic hydrocarbons like benzo[a]pyrene (BaP), is a major risk factor. In human esophageal HET-1A cells, we found that time-dependent BaP-DNA binding was associated with upregulation of CYP1B1, but not CYP1A1, mRNA and protein. The dietary flavonoid 5,7-dimethoxyflavone significantly inhibited BaP-DNA binding and down-regulated BaP-induced CYP1B1 mRNA and protein. 3',4'-Dimethoxyflavone was an even more potent inhibitor of CYP1B1 expression, while resveratrol had no effect. Thus, dietary methoxylated flavones inhibited BaP-induced CYP1B1 transcription in a cell-specific manner and hold promise as chemopreventive agents in esophageal carcinogenesis.

  4. Myeloperoxidase - 463A variant reduces benzo(a)pyrene diol epoxide DNA adducts in skin of coal tar treated patients

    Energy Technology Data Exchange (ETDEWEB)

    Rojas, M.; Godschalk, R.; Alexandrov, K.; Cascorbi, I.; Kriek, E.; Ostertag, J.; Van Schooten, F.J.; Bartsch, H. [German Cancer Research Center, Heidelberg (Germany). Div. of Toxicology & Cancer Risk Factors

    2001-07-01

    The skin of atopic dermatitis patients provides an excellent model to study the role of inflammation in benzo(a)pyrene (BaP) activation, since these individuals are often topically treated with ointments containing high concentrations of BaP. The authors determined, by HPLC with fluorescence detection, the BaP diol epoxide (BPDE)-DNA adduct levels in human skin after topical treatment with coal tar and their modulation by the -453G into A myeloperoxidase (MPO) polymorphism, which reduces MPO mRNA expression. The data show for the first time: (i) the in vivo formation of BPDE-DNA adducts in human skin treated with coal tar; (ii) that the MPO-463AA/AG genotype reduced BPDE-DNA adduct levels in human skin.

  5. Sediment balance in four small catechumen's with different land cover in the Central Pyrenes (Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Nadal Romero, E.; Lana-Renault, N.; Serrano-Muela, P.; Reguez, D.; Alvera, B.; Latron, J.; Marti-Bono, C.; Garcia-Ruiz, J. M.

    2009-07-01

    Four experimental catchment s in the Central Pyrenes were monitored by the Department of Geo-environmental Processes and global Change (Pyrenean Institute of Ecology, CSIC) to assess the hydrological and geomprophological consequences of various land uses and vegetation cover. The catchments were selected along an attitudinal and land-use gradient and included: (i) a sub-Mediterranean environment affected by intense weathering and erosion processes on marls, (ii) an old abandoned cultivated area undergoing vegetation regrowth, (iii) a barely-disturbed forest area, and (iv) a sub-alpine grassland in the high mountains, affected by snow accumulation and melting processes. The results demonstrate that plant cover is a key factor influencing the suspended sediment concentration, total sediment yield and proportion of different types of sediment. (Author) 7 refs.

  6. [Impact of benzo [a] pyrene the expression of mitochondrion-encoded genes in the earthworm Eisenia fetida].

    Science.gov (United States)

    Zheng, Sen-lin; Song, Yu-fang; Qiu, Xiao-yan; Sun, Tie-heng; Zhang, Wei; Ackland, M L

    2008-02-01

    The earthworm Eisenia fetida's benzo [a] pyrene (BaP) exposure experiments were carried out in artificial soil according to ISO 11268-1:1993. And then the upregulated and downregulated subtractive cDNA libraries were constructed by Clontech PCR-Select cDNA Subtration Kit. From the BaP exposure upregulated subtractive cDNA library, several cDNA segments matched mitochondrion-encoded genes were found, including cytochrome c oxidase subunit I (CO I), subunit II (CO II), subunit Ill (CO III), NADH dehydrogenase subunit 1 (NDH1), and ATP synthase subunit 6. The result indicated BaP and the subsequent oxidative stress disturbed the expression of mitochondrion-encoded genes, and this was potential biomarker for oxidative stress following xenobiotic exposure.

  7. Influence of perylenediimide–pyrene supramolecular interactions on the stability of DNA-based hybrids: Importance of electrostatic complementarity

    Directory of Open Access Journals (Sweden)

    Christian B. Winiger

    2014-07-01

    Full Text Available Aromatic π–π stacking interactions are ubiquitous in nature, medicinal chemistry and materials sciences. They play a crucial role in the stacking of nucleobases, thus stabilising the DNA double helix. The following paper describes a series of chimeric DNA–polycyclic aromatic hydrocarbon (PAH hybrids. The PAH building blocks are electron-rich pyrene and electron-poor perylenediimide (PDI, and were incorporated into complementary DNA strands. The hybrids contain different numbers of pyrene–PDI interactions that were found to directly influence duplex stability. As the pyrene–PDI ratio approaches 1:1, the stability of the duplexes increases with an average value of 7.5 °C per pyrene–PDI supramolecular interaction indicating the importance of electrostatic complementarity for aromatic π–π stacking interactions.

  8. EROD activity and genotoxicity in the seabob shrimp Xiphopenaeus kroyeri exposed to benzo[a]pyrene (BaP) concentrations.

    Science.gov (United States)

    da Silva Rocha, Arthur José; Gomes, Vicente; Rocha Passos, Maria José de Arruda Campos; Hasue, Fabio Matsu; Alves Santos, Thaís Cruz; Bícego, Márcia Caruso; Taniguchi, Satie; Van Ngan, Phan

    2012-11-01

    Seabob shrimp Xiphopenaeus kroyeri is a marine species that lives in shallow waters of coastal environments, often impacted by polycyclic aromatic hydrocarbons (PAH) pollution. In the present study, seabob shrimp were exposed for 96 h to benzo[a]pyrene (BaP) at the nominal concentrations of 100, 200, 400 and 800 microg-L(-1). Animals of the control groups were exposed either to clean water or to the BaP-carrier (DMSO). At the end of the exposures, muscle tissues were sampled for BaP uptake assessment and hepatopancreas and hemolymph for EROD enzyme activity and hemocytes DNA damage, respectively. EROD activity and DNA damage increased significantly as a function of BaP exposure concentrations. Significant correlations between BaP uptake and both EROD activity and DNA damage suggest that they can be used as suitable tools for integrated levels of study on the biomarkers of PAH exposure.

  9. Novel glass-forming organic materials. 2. Structure and fluorescence of pyrene- and carbazole-containing cyclohexane, bicyclooctene, and adamantane

    Energy Technology Data Exchange (ETDEWEB)

    Mastrangelo, J.C.; Conger, B.M.; Chen, S.H. [Univ. of Rochester, NY (United States)] [and others

    1997-01-01

    A series of novel glass-forming organic materials consisting of pyrenyl and carbazolyl groups attached to cyclohexane with a 1-axial-2-equatorial configuration, bicyclo[2.2.2]oct-7-ene with an all-exo configuration, and adamantane were synthesized and characterized. On the basis of proton NMR spectra, it was found that the rotation of pendant pyrenyl and carbazolyl groups is restricted in the bicyclic system presumably because of steric hindrance in the all-exo configuration. In contrast, free rotation was found to prevail in cyclohexane- and adamantane-based systems. Fluorescence spectra gathered in solution at room temperature show evidence exclusively for intramolecular excimer formation in pyrene-containing compounds up to a concentration of 10{sup -4} M. On the contrary, carbazole-containing compounds are not prone to excimer formation in the concentration range 10{sup -6}-10{sup -3} M, presumably because of the more stringent requirements of interchromophoric distance and orientation. Although both pyrene and carbazole are highly crystalline on their own, attachment to cyclic, bicyclic, and tricyclic central cores was found to contribute to an ease of vitrification of the hybrid systems with a T{sub g} ranging from 43 to 132 {degrees}C. Moreover, the quenched glasses of all seven model systems were found to possess morphological stability in view of the absence of recrystallization upon heating from 0 to 200 {degrees}C at a heating rate ranging from 0.2 to 20{degrees}C/min. Morphological stability was further supported by the absence of recrystallization upon prolonged thermal annealing at temperatures above T{sub g}. 24 refs., 6 figs.

  10. Propolis protects human spermatozoa from DNA damage caused by benzo[a]pyrene and exogenous reactive oxygen species.

    Science.gov (United States)

    Russo, A; Troncoso, N; Sanchez, F; Garbarino, J A; Vanella, A

    2006-02-23

    Many environmental, physiological and genetic factors have been implicated in defective sperm function, the most common cause of infertility. In addition, sperm preparation techniques such as centrifugation, used prior to in vitro fertilization, are associated with the generation of reactive oxygen species (ROS) and an increase in the level of DNA damage. Factors that can offer spermatozoa protection are, therefore, of great importance. This study was designed to examine in vitro the effect of a Chilean propolis ethanolic extract on human spermatozoa treated with benzo[a]pyrene and exogenous reactive oxygen species. Our experimental evidence demonstrated that the natural drug under investigation is able to protect genomic DNA by damage induced by benzo[a]pyrene, hydrogen peroxide (H2O2) and hydrogen peroxide in combination with adenosine 5'-diphosphate (ADP) and ferrous sulfate (FeSO4), determining a significant reduction of the intracellular oxidants. An increase in membrane damage, measured by monitoring the formation of thiobarbituric acid-reactive substances (TBARS) and lactic dehydrogenase (LDH) release, was observed only in sperm treated with H2O2, ADP and FeSO4. The propolis extract was shown to possess the capacity to protect sperm membrane from the deleterious action of oxidative attack, reducing TBARS formation and LDH release. In summary, our results evidence that the protective effect exhibited by this natural compound in human spermatozoa is correlated, at least in part, to the antioxidant capacity of its active components, and suggest that propolis may have a role in protection against male infertility.

  11. Antioxidant responses to benzo[a]pyrene and Aroclor 1254 exposure in the green-lipped mussel, Perna viridis

    Energy Technology Data Exchange (ETDEWEB)

    Cheung, C.C.C.; Siu, W.H.L.; Richardson, B.J.; De Luca-Abbott, S.B.; Lam, P.K.S

    2004-02-01

    In this study, the green-lipped mussel, Perna viridis (L.), was exposed to two concentrations of benzo[a]pyrene (B[a]P) (0.3 {mu}g l{sup -1}; 3 {mu}g l{sup -1}) and two concentrations of Aroclor 1254 (0.5 {mu}g l{sup -1}; 5 {mu}g l{sup -1}). In addition, a mixture of the contaminants was used (0.3 {mu}g l{sup -1} B[a]P+0.5 {mu}g l{sup -1} Aroclor 1254; 3 {mu}g l{sup -1} B[a]P+5 {mu}g l{sup -1} Aroclor 1254). All concentrations were nominal. A suite of enzymes [glutathione S transferase (GST), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR)], glutathione (GSH) level and lipid peroxidation (LPO) in the mussel gill and hepatopancreas were monitored over 18 days. CAT and GSH in gill tissue were positively correlated with concentration of Aroclor 1254. Activity of hepatic GST and SOD was significantly related to body burden of Aroclor 1254. LPO, GR and GPx in gill and hepatopancreas and hepatic GST were positively correlated with B[a]P concentration. The results indicate the importance of using biomarkers specific to the type of contaminant(s) that are likely to be present. Controlled laboratory experiments, such as this study, are useful in ascertaining biomarkers suitable for use with complex contaminant mixtures in the marine environment. - Benzo[a]pyrene and Aroclor 1254 separately and in combination caused specific induction in a number of antioxidant parameters in the gill and hepatopancreas of green-lipped mussels.

  12. [Protective Effect of Schisandra Extract on Embryotoxicity and Reproductive Toxicity in Early Pregnant Rats Exposed to Benzo [a] pyrene].

    Science.gov (United States)

    Liang, Jing; Hou, Hai-yan; Sun, Yang; Chen, Ya-qiong

    2016-02-01

    To observe protective effects of Schisandra extract (SE) on embryotoxicity and reproductive toxicity of early pregnant rats exposed to Benzo[a]pyrene (Bap). Pregnant rat model was prepared using periodic screening cage method. Totally 50 female pregnant SD rats were divided into five groups by randomized block design according to the weight, i.e., the BaP model group, the low dose SE group, the middle dose SE group, the high dose SE group, the normal control group, 10 rats in each group. Rats in the BaP model group were administered with BaP at a daily dose of 2 mg/kg by gastrogavage. Rats in low, middle, and high dose SE groups were administered by gastrogavage with BaP (at a daily dose of 2 mg/kg) plus SE at a daily dose of 40, 200, and 1 000 mg/kg, respectively. Equal volume of olive oil was administered to rats in the normal control group by gastrogavage. All medication was performed for 8 successive days. Changes of rat body weight in each period were observed. The uterus embryonic total quality and ovary quality were measured, and organ index calculated. The number of corpus luteum, the number of embryo implantation, and the number of absorbed embryo were statistically calculated respectively. The implantation rate and the absorbed embryos rate were calculated. Serum levels of human chorionic gonadotrophin β (β-HCG) and progesterone (PROG) were detected by ELISA. Compared with the normal control group, the weight of 9-day pregnant rats, the number of embryo implantation, the uterus embryonic total index, ovary index, serum levels of β-HCG and PROG all decreased in the Bap model group with significant difference (P body weight, the uterus embryonic total index, and the PROG level increased in 3 dose SE groups (P pregnant rats exposed to Benzo[a]pyrene.

  13. Toxicogenomic outcomes predictive of forestomach carcinogenesis following exposure to benzo(a)pyrene: Relevance to human cancer risk

    Energy Technology Data Exchange (ETDEWEB)

    Labib, Sarah, E-mail: Sarah.Labib@hc-sc.gc.ca; Guo, Charles H., E-mail: Charles.Guo@hc-sc.gc.ca; Williams, Andrew, E-mail: Andrew.Williams@hc-sc.gc.ca; Yauk, Carole L., E-mail: Carole.Yauk@hc-sc.gc.ca; White, Paul A., E-mail: Paul.White@hc-sc.gc.ca; Halappanavar, Sabina, E-mail: Sabina.Halappanavar@hc-sc.gc.ca

    2013-12-01

    Forestomach tumors are observed in mice exposed to environmental carcinogens. However, the relevance of this data to humans is controversial because humans lack a forestomach. We hypothesize that an understanding of early molecular changes after exposure to a carcinogen in the forestomach will provide mode-of-action information to evaluate the applicability of forestomach cancers to human cancer risk assessment. In the present study we exposed mice to benzo(a)pyrene (BaP), an environmental carcinogen commonly associated with tumors of the rodent forestomach. Toxicogenomic tools were used to profile gene expression response in the forestomach. Adult Muta™Mouse males were orally exposed to 25, 50, and 75 mg BaP/kg-body-weight/day for 28 consecutive days. The forestomach was collected three days post-exposure. DNA microarrays, real-time RT-qPCR arrays, and protein analyses were employed to characterize responses in the forestomach. Microarray results showed altered expression of 414 genes across all treatment groups (± 1.5 fold; false discovery rate adjusted P ≤ 0.05). Significant downregulation of genes associated with phase II xenobiotic metabolism and increased expression of genes implicated in antigen processing and presentation, immune response, chemotaxis, and keratinocyte differentiation were observed in treated groups in a dose-dependent manner. A systematic comparison of the differentially expressed genes in the forestomach from the present study to differentially expressed genes identified in human diseases including human gastrointestinal tract cancers using the NextBio Human Disease Atlas showed significant commonalities between the two models. Our results provide molecular evidence supporting the use of the mouse forestomach model to evaluate chemically-induced gastrointestinal carcinogenesis in humans. - Highlights: • Benzo(a)pyrene-mediated transcriptomic response in the forestomach was examined. • The immunoproteosome subunits and MHC class I

  14. Transgenerational inheritance of neurobehavioral and physiological deficits from developmental exposure to benzo[a]pyrene in zebrafish.

    Science.gov (United States)

    Knecht, Andrea L; Truong, Lisa; Marvel, Skylar W; Reif, David M; Garcia, Abraham; Lu, Catherine; Simonich, Michael T; Teeguarden, Justin G; Tanguay, Robert L

    2017-08-15

    Benzo[a]pyrene (B[a]P) is a well-known genotoxic polycylic aromatic compound whose toxicity is dependent on signaling via the aryl hydrocarbon receptor (AHR). It is unclear to what extent detrimental effects of B[a]P exposures might impact future generations and whether transgenerational effects might be AHR-dependent. This study examined the effects of developmental B[a]P exposure on 3 generations of zebrafish. Zebrafish embryos were exposed from 6 to 120h post fertilization (hpf) to 5 and 10μM B[a]P and raised in chemical-free water until adulthood (F0). Two generations were raised from F0 fish to evaluate transgenerational inheritance. Morphological, physiological and neurobehavioral parameters were measured at two life stages. Juveniles of the F0 and F2 exhibited hyper locomotor activity, decreased heartbeat and mitochondrial function. B[a]P exposure during development resulted in decreased global DNA methylation levels and generally reduced expression of DNA methyltransferases in wild type zebrafish, with the latter effect largely reversed in an AHR2-null background. Adults from the F0 B[a]P exposed lineage displayed social anxiety-like behavior. Adults in the F2 transgeneration manifested gender-specific increased body mass index (BMI), increased oxygen consumption and hyper-avoidance behavior. Exposure to benzo[a]pyrene during development resulted in transgenerational inheritance of neurobehavioral and physiological deficiencies. Indirect evidence suggested the potential for an AHR2-dependent epigenetic route. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  15. Development and validation of a direct sandwich chemiluminescence immunoassay for measuring DNA adducts of benzo[a]pyrene and other polycyclic aromatic hydrocarbons

    DEFF Research Database (Denmark)

    Georgiadis, Panagiotis; Kovács, Katalin; Kaila, Stella;

    2012-01-01

    We have developed and validated a sandwich chemiluminescence immunoassay (SCIA) which measures polycyclic aromatic hydrocarbon (PAH)-DNA adducts combining high throughput and adequate sensitivity, appropriate for evaluation of adduct levels in human population studies. Fragmented DNA is incubated...... with rabbit antiserum elicited against DNA modified with r7,t8-dihydroxy-t-9,10-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene (BPDE) and subsequently trapped by goat anti-rabbit IgG bound to a solid surface. Anti-single-stranded (ss) DNA antibodies binds in a quantity proportional to the adduct levels...... and is detected by chemiluminescence. The BPDE-DNA SCIA has a limit of detection of 3 adducts per 10(9) nucleotides with 5 µg DNA per well. We have validated the BPDE-DNA SCIA using DNA modified in vitro, DNA from benzo[a]pyrene (BP)-exposed cultured cells and mice. The levels of adduct measured by SCIA were...

  16. A Reversible Pyrene-based Turn-on Luminescent Chemosensor for Selective Detection of Fe(3+) in Aqueous Environment with Logic Gate Application.

    Science.gov (United States)

    Mukherjee, Soma; Talukder, Shrabani

    2016-05-01

    A new Schiff-base, HL luminescent chemosensor of 1-amino pyrene and 8-hydroxy quinoline-2-carboxaldehyde was synthesized which demonstrates selective fluorimetric detection of Fe(3+) in aqueous medium with detection limit of 2.52 × 10(-8) M. The receptor shows selective 'turn-on' response towards Fe(3+) over other metal ions. This gradual 'turn-on' fluorescence response for Fe(3+) may be induced via CHEF (chelation-enhanced fluorescence) through close proximity of pyrene rings. The stoichiometry and binding property of HL with Fe(3+) was examined by emission studies. In presence of Fe(3+), HL also exhibits reversible change in emission pattern with EDTA and thus offers an interesting property of molecular 'INHIBIT' logic gate with Fe(3+) and EDTA as chemical inputs.

  17. Increased Sensitivity to Testicular Toxicity of Transplacental Benzo[a]pyrene Exposure in Male Glutamate Cysteine Ligase Modifier Subunit Knockout (Gclm−/−) Mice

    OpenAIRE

    Nakamura, Brooke N.; Mohar, Isaac; Lawson, Gregory W.; Cortés, Mabel M.; Hoang, Yvonne D.; Ortiz, Laura; Patel, Reshma; Rau, Bogdan A.; McConnachie, Lisa A.; Kavanagh, Terrance J.; Luderer, Ulrike

    2012-01-01

    Polycyclic aromatic hydrocarbons (PAHs), like benzo[a]pyrene (BaP), are ubiquitous environmental pollutants formed by the incomplete combustion of organic materials. The tripeptide glutathione (GSH) is a major antioxidant and is important in detoxification of PAH metabolites. Mice null for the modifier subunit of glutamate cysteine ligase (Gclm), the rate-limiting enzyme in GSH synthesis, have decreased GSH concentrations. We investigated the effects of Gclm deletion alone on male fertility a...

  18. [Membrane-bound sialoglycoproteins of the rat liver as affected by the combined action of benz(a)pyrene and sulfur dioxide].

    Science.gov (United States)

    Merkur'eva, R V; Bushinskaia, L I; Skvortsova, N I; Dolinskaia, S I; Shaternikova, I S

    1981-01-01

    Simultaneous effect of benz(a)pyrene and sulphurous gas was accompanied by distinct alteration in metabolism of sialoglycoproteins in liver tissue; at the time N-acetylneuraminic acid was redistributed in liver subcellular organelles (mitochondria, lysosomes and endoplasmic reticulum) as well as cytochromes P-450 and b5 were induced in liver microsomes. The alterations observed appear to play a definite role in manifestation of the unfavourable effect in combined action of the carcinogen and chemical contaminations of environments.

  19. Application of Phenyl Bonded Mesoporous Silica as A Novel Coating Layer of Solid-phase Microextraction for Determination of Benzo[a]pyrene in Water Samples

    Institute of Scientific and Technical Information of China (English)

    Xin Zhen DU; Ya Rong WANG; Qian MA; Xue Feng MAO; Jin Guo HOU

    2005-01-01

    Phenyl bonded mesoporous silica (C6H5-MCM-41) was applied as the fiber coating of solid-phase microextraction (SPME). The performance of the fiber coating was discussed coupling to HPLC. Applicability of mesoporous fiber coating was examined for the determination of benzo[a]pyrene (B[a]P) in water samples, The limit of detection (LOD) is 0.28μg.L-1. Good recovery and relative standard deviation (RSD) were obtained.

  20. Ascorbic acid inhibits the squamous metaplasia that results from treatment of tracheal explants with asbestos or benzo[a]pyrene-coated asbestos.

    Science.gov (United States)

    Holtz, G; Bresnick, E

    1988-01-01

    Hamster tracheal explants were maintained in culture in the presence or absence of benzo[a]pyrene (BP), crocidolite asbestos, or BP-coated crocidolite. Dose-dependent squamous metaplasia was observed in the treated samples. L-Ascorbic acid and DL-alpha-tocopherol were able to partially protect the tracheal explants from the metaplastic response induced by crocidolite. Furthermore, ascorbic acid reduced the extent of metaplasia observed in hamster tracheal explants that were exposed to BP-crocidolite.

  1. Amplified fluorescence detection of adenosine via catalyzed hairpin assembly and host-guest interactions between β-cyclodextrin polymer and pyrene.

    Science.gov (United States)

    Huang, Haihua; Yang, Xiaohai; Wang, Kemin; Wang, Qing; Guo, Qiuping; Huang, Jin; Liu, Jianbo; Song, Chunxia

    2016-04-21

    Nowadays, enzyme-free nucleic acid-based signal amplification strategies are frequently utilized in the design of biosensors due to their excellent sensitivity. Developing more extended analytical methods is fundamental for basic studies in the biological and biomedical fields. Herein, we introduce an enzyme-free amplified detection strategy for the small molecule adenosine. The approach is based on adenosine-aptamer binding triggered catalyzed hairpin assembly and host-guest interactions between β-cyclodextrin polymer (β-CDP) and pyrene. Two hairpin probes (probe H1 and probe H2) and an aptamer-trigger/inhibitor duplex probe were employed in the system and the pyrene-labeled probe H1 was chosen as the signal unit. In the absence of adenosine, the aptamer-trigger was inhibited by the inhibitor strand. The hairpin probes were in the closed hairpin formation without activation of the trigger strand. Pyrene labeled at the 5'-termini of the single-stranded stem of probe H1 could be easily trapped in the hydrophobic cavity of β-CDP because of weak steric hindrance, leading to a significant fluorescence enhancement. Once the hairpin assembly was catalyzed by the adenosine-aptamer binding event, a hybridized DNA duplex H1/H2 was created continuously. Pyrene labeled at the 5'-termini of the DNA duplex H1/H2 finds it difficult to enter the cavity of β-CDP due to steric hindrance, leading to a weaker fluorescence signal. Thus, the target could be detected by this simple mix-and-detect amplification method without a need for expensive and perishable protein enzymes. As low as 42 nM of adenosine was detected by this assay, which is comparable to that of some reported colorimetric methods. Meanwhile, the proposed method was further successfully applied to detect adenosine in human serum samples, showing great potential for adenosine detection from complex fluids.

  2. Synthesis of block copolymers derived from N-trityl-(S)-serine and pyrene end-labeled poly(methyl methacrylate) or poly(N-isopropylacrylamide) via ATRP

    Energy Technology Data Exchange (ETDEWEB)

    Buruiana, Emil C., E-mail: emilbur@icmpp.ro [Petru Poni Institute of Macromolecular Chemistry, 41A Gr. Ghica Voda Alley 700487, Iasi (Romania); Podasca, Viorica; Buruiana, Tinca [Petru Poni Institute of Macromolecular Chemistry, 41A Gr. Ghica Voda Alley 700487, Iasi (Romania)

    2012-10-15

    A new monomer bearing N-trityl-L-serine methyl ester in structure, methacryloyloxyethyl carbamoyloxy-N-trityl methyl serine (MTS), was prepared to be further polymerized by atom transfer radical polymerization (ATRP) with pyrene-endcapped poly(methyl methacrylate) (Py-PMMA-Br) or poly(N-isopropylacrylamide) (Py-PNIPA-Br). The resulting block copolymers, poly(methyl methacrylate-block-methacryloyloxyethyl carbamoyloxy-N-trityl methyl serine) (Py-PMMA-b-PMTS) and poly(N-isopropylacrylamide-block-methacryloyloxyethyl carbamoyloxy-N-trityl methyl serine (Py-PNIPA-b-PMTS) were characterized by {sup 1}H ({sup 13}C) NMR, ultraviolet, FTIR and fluorescence spectroscopy, thermal analysis, differential scanning calorimetry (DSC), atomic force microscopy (AFM), scanning electron microscopy (SEM), and gel permeation chromatography (GPC) measurements. The chemical composition in Py-PMMA-b-PMTS was estimated from the {sup 1}H NMR analysis that indicated a ratio of the repeating units of 46:19 (MMA:MTS). For the Py-PNIPA-b-PMTS the composition rate in the copolymer was 61:25 (NIPA:MTS). Quenching of the pyrene species with N,N-diethylaniline, nitrobenzene, nitrophenol, potassium iodide, p-nitrotoluene and tetracyanoquinodimethane (TCNQ) in DMF solution excited at 348 nm was evidenced, more efficiently being nitrophenol and TCNQ. In this case, the monomer emission at 388-409 nm underwent a significant decrease caused of an electron transfer from the electron-reach photoexcited pyrene molecule to the electron-deficient quenchers. - Highlights: Black-Right-Pointing-Pointer Diblock copolymers combine the fluorescence of pyrene-PMMA (PNIPA) with the characteristics of PMTS. Black-Right-Pointing-Pointer Such copolymers could be used for nitroderivatives detecting. Black-Right-Pointing-Pointer UV/vis and fluorescence measurements give a good correlation for LCST of Py-PNIPA-Br.

  3. Synthesis, in vitro β-glucuronidase inhibitory activity and in silico studies of novel (E)-4-Aryl-2-(2-(pyren-1-ylmethylene)hydrazinyl)thiazoles.

    Science.gov (United States)

    Salar, Uzma; Khan, Khalid Mohammed; Syed, Shazia; Taha, Muhammad; Ali, Farman; Ismail, Nor Hadiani; Perveen, Shahnaz; Wadood, Abdul; Ghufran, Mehreen

    2017-02-01

    Current research is based on the synthesis of novel (E)-4-aryl-2-(2-(pyren-1-ylmethylene)hydrazinyl)thiazole derivatives (3-15) by adopting two steps route. First step was the condensation between the pyrene-1-carbaldehyde (1) with the thiosemicarbazide to afford pyrene-1-thiosemicarbazone intermediate (2). While in second step, cyclization between the intermediate (2) and phenacyl bromide derivatives or 2-bromo ethyl acetate was carried out. Synthetic derivatives were structurally characterized by spectroscopic techniques such as EI-MS, (1)H NMR and (13)C NMR. Stereochemistry of the iminic double bond was confirmed by NOESY analysis. All pure compounds 2-15 were subjected for in vitro β-glucuronidase inhibitory activity. All molecules were exhibited excellent inhibition in the range of IC50=3.10±0.10-40.10±0.90μM and found to be even more potent than the standard d-saccharic acid 1,4-lactone (IC50=48.38±1.05μM). Molecular docking studies were carried out to verify the structure-activity relationship. A good correlation was perceived between the docking study and biological evaluation of active compounds.

  4. Enhanced oxidation of benzo[a]pyrene by crude enzyme extracts produced during interspecific fungal interaction of Trametes versicolor and Phanerochaete chrysosporium

    Institute of Scientific and Technical Information of China (English)

    Linbo Qian; Baoliang Chen

    2012-01-01

    The effects of interspecific fungal interactions between Trametes versicolor and Phanerochaete chrysosporium on laccase activity and enzymatic oxidation of polycyclic aromatic hydrocarbons (PAHs) were investigated.A deadlock between the two mycelia rather than replacement of one fungus by another was observed on an agar medium.The laccase activity in crude enzyme extracts from interaction zones reached a maximum after a 5-day incubation,which was significantly higher than that from regions of T.versicolor or P.chrysosporium alone.The enhanced induction of laccase activity lasted longer in half nutrition than in normal nutrition.A higher potential to oxidize benzo[a]pyrene by a crude enzyme preparation extracted from the interaction zones was demonstrated.After a 48 hr incubation period,the oxidation of benzo[a]pyrene by crude enzyme extracts from interaction zones reached 26.2%,while only 9.5% of benzo[a]pyrene was oxidized by crude extracts from T.versicolor.The oxidation was promoted by the co-oxidant 2,2'-azinobis-3-ethylbenzthiazoline-6-sulphonate diammonium salt (ABTS).These findings indicate that the application of co-culturing of white-rot fungi in bioremediation is a potential ameliorating technique for the restoration of PAH-contaminated soil.

  5. An investigation of endocrine disrupting effects and toxic mechanisms modulated by benzo[a]pyrene in female scallop Chlamys farreri

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Shuangmei; Pan, Luqing, E-mail: panlq@ouc.edu.cn; Sun, Xiaohua

    2013-11-15

    Highlights: •B[a]P disturbed progesterone, 17β-estradiol and testosterone production in scallop. •B[a]P inhibited 3β-HSD, CYP17 and 17β-HSD expression after a 10-day exposure. •B[a]P of lower dose elevated AHR-CYP1A expression but high dose B[a]P inhibited them. •ER and vitellogenin transcription was consistent with AHR after B[a]P exposure. •B[a]P exposure induced relatively developmental delay and impairment of ovary. -- Abstract: The purpose of this study was to investigate the endocrine disrupting effects induced by benzo[a]pyrene (B[a]P) and explore the underlying mechanisms in mollusks. In this study, sexually mature female Chlamys farreri were exposed to benzo[a]pyrene for 10 days at four different concentrations as 0, 0.025, 0.5 and 10 μg/L. Sex steroids were identified and quantified by electrochemiluminescence immunoassay (ECLIA) method and results showed that exposure to B[a]P exerts great suppression on 17β-estradiol, testosterone production and disrupts progesterone levels in ovary. Transcription of genes were detected and measured by real-time RT-PCR. It showed that at day 10 B[a]P inhibited 3β-HSD, CYP17 and 17β-HSD mRNA expression in a dose-dependent manner, which suggests that they could be potential targets of B[a]P that disrupt steroidogenic machinery. Moreover, 0.025 μg/L B[a]P activated transcription of aryl hydrocarbon receptor (AHR), AHR nuclear translocator (ARNT), CYP1A1 and estrogen receptor (ER), while 10 μg/L B[a]P suppressed all of them. The consistency of their responses to B[a]P exposure implies that AHR action may be involved in invertebrate CYP regulation and ER transcription despite of unknown mechanisms. Additionally, B[a]P exposure could induce ovarian impairment and developmental delay in C. farreri. Overall, sensitivity of C. farreri to endocrine disruption and toxicity suggests that C. farreri is a suitable species for study of endocrine-disrupting effects in marine invertebrates. This study will form a

  6. Method for determining monohydroxybenzo[a]pyrene isomers using column-switching high-performance liquid chromatography.

    Science.gov (United States)

    Toriba, Akira; Nakamura, Hiroaki; Chetiyanukornkul, Thaneeya; Kizu, Ryoichi; Makino, Tsunehisa; Nakazawa, Hiroyuki; Yokoi, Tsuyoshi; Hayakawa, Kazuichi

    2003-01-01

    A method for determining monohydroxybenzo[a]pyrene (OHBaP) isomers using column-switching high-performance liquid chromatography with fluorescence detection was developed. Eleven of 12 isomers of OHBaP (all except 6-OHBaP) were separated on an alkylamide-type reversed-phase column and, via column-switching, on a beta-cyclodextrin-bonded silica gel column. The detection limits for the OHBaPs were in the range 0.3-8 pg/injection (S/N=3). By using this method, 1-, 3-, and 9-OHBaPs were identified as major metabolites of benzo[a]pyrene in vitro by human recombinant p450 1A1. The method was used to determine OHBaPs in the urine of a nonsmoker subject. After enzymatic hydrolysis of the conjugated metabolites by beta-glucuronidase/aryl sulfatase, the analytes were selectively adsorbed on blue rayon (a cellulose-supported copper phthalocyanine) from the urine matrix. Methanol as the eluting solvent from the rayon gave the best recoveries of OHBaPs and 1-hydroxypyrene (1-OHP) in the range of 91-103%, which was superior to that of the solid-phase extraction method. 1-OHP, a well-known biomarker of the exposure to polycyclic aromatic hydrocarbons, was simultaneously analyzed. Intra- and interday accuracy values for the determination of 3-OHBaP in 200 ml of urine were 95.5 and 100.9%, and those for 1-OHP were 96.4 and 103.6%, respectively. The intra- and interday precision values were 3.9 and 2.4% for 3-OHBaP and 2.4 and 3.2% for 1-OHP, respectively. In 11 kinds of isomers, only 3-OHBaP was detected in the human urine. Urinary concentration of 3-OHBaP was quantified at 0.5 ng/g creatinine concentration and the 3-OHBaP/1-OHP ratio was approximately 1/130.

  7. Inhibitory effects of polysaccharides isolated from Phellinus gilvus on benzo(a)pyrene-induced forestomach carcinogenesis in mice

    Institute of Scientific and Technical Information of China (English)

    Jae-Sung Bae; Kwang-Ho Jang; Hyunee Yim; Seung-Chun Park; Hee-Kyung Jin

    2005-01-01

    AIM: Although polysaccharides from Phellinus mushrooms are a well-known material with anti-tumor properties, there is no information about the effect of polysaccharides from Phellinus gilvus (PG) on tumor. The modulating effect of polysaccharides isolated from PG on the benzo(a)pyrene (BaP)-induced forestomach carcinogenesis in ICR female mice was investigated in this study.METHODS: A forestomach carcinogenesis model was established in 40 ICR female mice receiving oral administration of BaP for 4 wk. The mice were randomly assigned to 4 groups (10 each). The mice in each group were treated with sterile water or PG for 4 and 8 wk (SW4,PGW4, SW8, and PGW8 groups). Eight or 12 wk after the first dose of BaP, forestomachs were removed for histopathological and RT-PCR analysis.RESULTS: In histopathological changes and RT-PCR analysis, sterile water-treated mice showed significant hyperplasia of the gastric mucosa with a significantly increased expression of mutant p53 mRNA compared to mice treated with PG for 8 wk.CONCLUSION: Polysaccharides isolated from PG may inhibit BaP-induced forestomach carcinogenesis in mice bydown-regulating mutant p53 expression.

  8. Single-solute and bi-solute sorption of phenanthrene and pyrene onto pine needle cuticular fractions

    Energy Technology Data Exchange (ETDEWEB)

    Li Yungui [Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang 310028 (China); Chen Baoliang, E-mail: blchen@zju.edu.c [Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang 310028 (China); Zhu Lizhong [Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang 310028 (China)

    2010-07-15

    To better understand interaction mechanisms of pine needles with persistent organic pollutants, single-solute and bi-solute sorption of phenanthrene and pyrene onto isolated cuticular fractions of pine needle were investigated. The structures of cuticular fractions were characterized by elemental analysis, Fourier transform infrared spectroscopy and solid-state {sup 13}C NMR. Polymeric lipids (cutin and cutan) exhibited notably higher sorption capabilities than the soluble lipids (waxes), while cellulose showed little affinity with sorbates. With the coexistence of the amorphous cellulose, the sorption of cutan (aromatic core) was completely inhibited, so the cutin components (nonpolar aliphatic moieties) dominated the sorption of bulk needle cuticle. By the consumption of the amorphous cellulose under acid hydrolysis, sorption capacities of the de-sugared fractions were dramatically enhanced, which controlled by the exposed aromatic cores and the aliphatic moieties. Furthermore, the de-sugared fractions demonstrated nonlinear and competitive sorption due to the specific interaction between aromatic cores and polycyclic aromatic hydrocarbon. - Cellulose components play a regulating role in the relative contribution of aromatic cores and aliphatic moieties to sorption of pine needle cuticular fractions.

  9. Effects of benzo(a)pyrene on the skeletal development of Sebastiscus marmoratus embryos and the molecular mechanism involved

    Energy Technology Data Exchange (ETDEWEB)

    He Chengyong [Key Laboratory of Ministry of Education for Subtropical Wetland Ecosystem Research, School of Life Sciences, Xiamen University, Xiamen (China); Zuo Zhenghong [Key Laboratory of Ministry of Education for Subtropical Wetland Ecosystem Research, School of Life Sciences, Xiamen University, Xiamen (China); State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen (China); Shi Xiao; Li Ruixia; Chen Donglei; Huang Xin; Chen Yixin [Key Laboratory of Ministry of Education for Subtropical Wetland Ecosystem Research, School of Life Sciences, Xiamen University, Xiamen (China); Wang Chonggang, E-mail: cgwang@xmu.edu.cn [Key Laboratory of Ministry of Education for Subtropical Wetland Ecosystem Research, School of Life Sciences, Xiamen University, Xiamen (China); State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen (China)

    2011-01-25

    Polycyclic aromatic hydrocarbons (PAHs) are widespread environmental contaminants, which have been known to be carcinogenic and teratogenic. However, the skeletal development toxicity of PAHs and the mechanism involved remain unclear. In fishes, the neurocranial and craniofacial skeleton develop as cartilage. The signaling molecules of hedgehog (Hh) family play crucial roles in regulating skeletal development. In the present study, rockfish (Sebastiscus marmoratus) embryos were exposed to benzo(a)pyrene (BaP) for 7 days at environmental levels (0.05, 0.5 and 5 nmol/L) which resulted in craniofacial skeleton deformities. BaP exposure reduced the cell proliferation activity in the craniofacial skeleton as detected by quantitative PCR and in situ hybridization. The expression of Sonic hedgehog (Shh), rather than Indian hedgehog (Ihh), was down-regulated in the craniofacial skeleton in the 0.5 and 5 nmol/L groups. Consistent with the Shh results, the expression of Ptch1 and Gli2 was decreased by BaP exposure and BMP4 was presented on changes in the 0.5 and 5 nmol/L groups. These results suggested that BaP could impair the expression and function of Shh signaling pathway, perturbing the proliferation of chondrocytes and so disturbing craniofacial skeletal development.

  10. Metabolic and immune impairments induced by the endocrine disruptors benzo[a]pyrene and triclosan in Xenopus tropicalis.

    Science.gov (United States)

    Regnault, Christophe; Willison, John; Veyrenc, Sylvie; Airieau, Antinéa; Méresse, Patrick; Fortier, Marlène; Fournier, Michel; Brousseau, Pauline; Raveton, Muriel; Reynaud, Stéphane

    2016-07-01

    Despite numerous studies suggesting that amphibians are highly sensitive to cumulative anthropogenic stresses, the role played by endocrine disruptors (EDs) in the decline of amphibian populations remains unclear. EDs have been extensively studied in adult amphibians for their capacity to disturb reproduction by interfering with the sexual hormone axis. Here, we studied the in vivo responses of Xenopus tropicalis males exposed to environmentally relevant concentrations of each ED, benzo[a]pyrene (BaP) and triclosan (TCS) alone (10 μg L(-1)) or a mixture of the two (10 μg L(-1) each) over a 24 h exposure period by following the modulation of the transcription of key genes involved in metabolic, sexual and immunity processes and the cellular changes in liver, spleen and testis. BaP, TCS and the mixture of the two all induced a marked metabolic disorder in the liver highlighted by insulin resistance-like and non-alcoholic fatty liver disease (NAFLD)-like phenotypes together with hepatotoxicity due to the impairment of lipid metabolism. For TCS and the mixture, these metabolic disorders were concomitant with modulation of innate immunity. These results confirmed that in addition to the reproductive effects induced by EDs in amphibians, metabolic disorders and immune system disruption should also be considered.

  11. Phosphorylation regulates proteolytic efficiency of TEV protease detected by a 5(6)-carboxyfluorescein-pyrene based fluorescent sensor.

    Science.gov (United States)

    He, Yao-Hui; Li, Yan-Mei; Chen, Yong-Xiang

    2016-04-01

    TEV protease is of great importance for in vitro and in vivo site-specific cleavage of proteins. The proteolytic efficiency of TEV protease is often regulated by mutation of the substrate, which is irreversible and hard to be modulated. Herein, a facile and reversible method, based on phosphorylation in the substrate, is developed to regulate the cleavage capability of TEV protease. Phosphorylation at P3 tyrosine hinders the recognition of TEV protease to the substrate by using a robust fluorescent protease sensor. Moreover, the phosphate group can be easily removed by alkaline phosphatases for recovering the proteolytic efficiency of TEV protease. Additionally, 5(6)-carboxyfluorescein and pyrene have been used as high-efficiency mutual fluorophore-quencher pair in the peptide-based protease sensor for the first time, which provides a chance to simultaneously monitor the cleavage process in two respective fluorescence channels. Further studies indicated both dynamic and static components contributing to the mutual quenching system. The phosphorylation-regulated TEV protease proteolysis system can be used in conditional cleavage of protein or peptide tag.

  12. Relationship between urinary levels of 1-hydroxypyrene and 3-hydroxybenzo(a)pyrene for workers exposed to polycyclic aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Gendre, C.; Lafontaine, M.; Morele, Y.; Payan, J.P.; Simon, P. [Institut National de Recherche et Securite, Vandoeuvre Les Nancy (France)

    2002-07-01

    Biomonitoring of workers was carried out in three working areas - an artificial target factory, an aluminum plant, and an electrometallurgy plant - to assess exposure to PAHs. All the 48 hr-voided urine samples of the exposed workers were collected and the 3-hydroxybenzo(a)pyrene (3-OHBaP) and 1-hydroxypyrene (1-OHPy) analyzed according to procedures using automated column-switching high-performance liquid chromatography. The exposure profiles indicate an important log between the excretion of the two metabolites: the maximum of 3-OHBaP urinary excretion is observed 10 to 17 hr after the 1-OHPy maximum, with a much closer correlation (r = 0.81) than that obtained with both metabolites in real time (r = 0.21). This delayed excretion agrees with data from animal intoxication studies (intravenous administration or inhalation). Mean ratios of 1-OHPy to 3-OHBaP were studied without lag (varying from 2,230 to 15,330) and with a tag of 16 hr (varying from 940 to 8,390).

  13. Can we use modelling methodologies to assess airborne benzo[a]pyrene from biomonitors? A comprehensive evaluation approach

    Directory of Open Access Journals (Sweden)

    N. Ratola

    2015-09-01

    Full Text Available Biomonitoring data available on levels of atmospheric polycyclic aromatic hydrocarbons (PAHs in pine needles from the Iberian Peninsula was used to estimate air concentrations of benzo[a]pyrene (BaP and, at the same time, fuelled the comparison with chemistry transport model representations. Simulations with the modelling system WRF + CHIMERE were validated against data from the European Monitoring and Evaluation Programme (EMEP air sampling network and using modelled atmospheric concentrations as a consistent reference in order to compare the performance of vegetation-to-air estimating methods. A spatial and temporal resolution of 9 km and 1 h was implemented. The field-based database relied on a pine needles sampling scheme comprising 33 sites in Portugal and 37 sites in Spain complemented with the BaP measurements available from the EMEP sites. The ability of pine needles to act as biomonitoring markers for the atmospheric concentrations of BaP was estimated converting the levels obtained in pine needles into air concentrations by six different approaches, one of them presenting realistic concentrations when compared to the modelled atmospheric values. The justification for this study is the gaps still existing in the knowledge of the life cycles of semi-volatile organic compounds (SVOCs, particularly the partition processes between air and vegetation. The strategy followed in this work allows the definition of the transport patterns (e.g. dispersion established by the model for atmospheric concentrations and the estimated values in vegetation.

  14. Fenton degradation assisted by cyclodextrins of a high molecular weight polycyclic aromatic hydrocarbon benzo[a]pyrene.

    Science.gov (United States)

    Veignie, Etienne; Rafin, Catherine; Landy, David; Fourmentin, Sophie; Surpateanu, Gheorghe

    2009-09-15

    This paper investigates the effect of native beta-cyclodextrin (beta-CD) and its CD derivatives, such as hydroxypropyl-beta-cyclodextrin (HPBCD) and randomly methylated-beta-cyclodextrin (RAMEB), on the solubilization of a high molecular weight polycyclic aromatic hydrocarbon benzo[a]pyrene (BaP) and on its degradation by Fenton's reaction. The results show that BaP apparent solubility was significantly increased in the presence of cyclodextrin (CD) in the following order: beta-CDcyclodextrin to solubilize BaP. In the presence of a radical scavenger (mannitol), BaP Fenton degradation was inhibited with RAMEB but not in the presence of HPCD. Molecular modelisation was used to visualize the steric complementarity of these host-guest systems. No significant difference of encapsulation between the two modified CDs was observed. Nevertheless, the results suggest a probable existence of a ternary complex HPCD-BaP-iron permitting the generation of hydroxyl radicals in close proximity to BaP. On the basis of these results, it appears that HPCD may be useful for developing targeted BaP degradation system.

  15. Paternal Benzo[a]pyrene Exposure Modulates MicroRNA Expression Patterns in the Developing Mouse Embryo

    Directory of Open Access Journals (Sweden)

    Asgeir Brevik

    2012-01-01

    Full Text Available Little attention has been given to how microRNA expression is affected by environmental contaminants exposure. We investigate the effects of paternal exposure to benzo[a]pyrene (B[a]P on miRNA expression in the developing mouse embryo. Male mice were exposed to B[a]P (150 mg/kg i.p., and their sperm was used four days later in in-vitro fertilization experiments. Twenty embryos each from 2-, 8-cell and the blastocyst stage were used for genome-wide miRNA expression profiling. Paternal exposure to B[a]P affected the expression of several miRNAs, and the target genes for some of the dysregulated miRNAs were enriched in many different pathways that are likely to be relevant for the developing mouse embryo. By linking the miRNA target genes to publicly available databases, we identified some miRNA target genes that may serve as global markers of B[a]P-mediated genotoxic stress. The dysregulated miRNAs may provide valuable knowledge about potential transgenerational effects of sublethal exposure to chemicals.

  16. Effects of benzo(a)pyrene on differentially expressed genes and haemocyte parameters of the clam Venerupis philippinarum.

    Science.gov (United States)

    Liu, Na; Pan, Luqing; Gong, XiaoLi; Tao, Yanxia; Hu, Yanyan; Miao, Jingjing

    2014-03-01

    In this study a suppression subtractive hybridisation method was employed to identify differentially expressed genes of the clam Venerupis philippinarum exposed to benzo(a)pyrene (BaP). Nineteen known transcripts and seven predicted proteins were found from the subtractive cDNA library of the clam, which could provide more sequence information for further study. Seven of the differentially expressed genes were selected for mRNA expression analysis. Real-time PCR analysis revealed that the expression level of the selected cDNAs of clams was up-regulated to varying degrees by different concentration of BaP. They are suggested as potential molecular biomarkers for polycyclic aromatic hydrocarbons (PAHs) pollution monitoring in aquatic ecosystems. In addition, haemocyte parameters were also measured, and a decrease of total haemocyte counts and suppression of antibacterial and bacteriolytic activities were detected in BaP-stressed clams. We suggest that the modulation of the expression of the selected genes caused by PAHs probably leads to the disturbance of the immune defense of the clam. Meanwhile, the adverse effects of PAHs on haemocyte parameters caused the suppression of the immune defense and susceptibility to infectious diseases. Therefore, it is inferred that PAHs pollutants could interact with components of the immune system and interferes with defense functions of the clam V. philippinarum.

  17. Olive oil protects rat liver microsomes against benzo(a)pyrene-induced oxidative damages: an in vitro study.

    Science.gov (United States)

    Devi, Kasi Pandima; Kiruthiga, Perumal Vijayaraman; Pandian, Shanmugiahthevar Karutha; Archunan, Govindaraju; Arun, Solayan

    2008-06-01

    Benzo(a)pyrene (B(a)P), a member of the polycyclic aromatic hydrocarbon family is present ubiquitously in the environment. One of its toxic effects is induction of oxidative stress (mediated by the enzyme B(a)P hydroxylase) which leads to various diseases like cancer. Olive oil (OO) that consists of many antioxidant compounds is reported to have many beneficial properties including protection against cancer. The objective of the present study is to evaluate the effect of OO on B(a)P hydroxylase enzyme and further elucidate the antioxidant capacity of OO against B(a)P-induced toxicity. Rat liver microsomes were divided into three groups: vehicle control, B(a)P treated group, and OO + B(a)P co-incubated group. Antioxidant enzymes which were decreased and protein carbonyl content and lipid peroxidation products which were increased on exposure to B(a)P was attenuated to near normal on OO exposure. B(a)P hydroxylase enzyme was very low in OO incubated group which may be due to inhibition of the enzyme by OO or high utilization for the metabolism of B(a)P. Further, no B(a)P metabolites (3-OH B(a)P and B(a)P 7,8-dihydrodiol) were identified in HPLC during B(a)P + OO exposure. The results prove the protective role of OO against B(a)P-induced oxidative damage.

  18. Stabilization of membrane bound ATPases and lipid peroxidation by carotenoids from Chlorococcum humicola in Benzo(a)pyrene induced toxicity

    Institute of Scientific and Technical Information of China (English)

    Bhagavathy S; Sumathi P

    2012-01-01

    Objective: To identify the alteration of the membrane potential and the effect of carotenoid extracts from Chlorococcum humicola (C. humicola) on membrane bound ATPases and lipid peroxidation. Methods: The total carotenoids were extracted from C. humicola. Four groups of Swiss albino mice were treated as control, Benzo(a)pyrene [B(a)P], total carotenoids, B(a)P +total carotenoids respectively for a period of 60 days. Membrane lipid peroxidation and ATPases (Total ATPases, Ca2+- ATPases, Mg2+ - ATPases, Na+K+ - ATPase) were determined in lung, liver and erythrocyte samples. Results: The activity of total ATPase was found to be significantly increased in the B(a)P treated liver and lung tissue. Erythrocyte membrane also showed higher ATPase activity which was significantly reverted on total carotenoid treatment. Conclusions:It can be concluded that the changes in membrane potential favour the functional deterioration of physiological system. The overall findings demonstrates that the animals post treated with carotenoid extract from C. humicola may maintains the alterations in membrane bound ATPase and lipid peroxidation in tissues against the carcinogenic chemical and hence aid in establishing the membrane potential action. Therefore C. humicola can be further extended to exploits its possible application for various health benefits as neutraceuticals and food additives.

  19. Attenuation of phenanthrene and pyrene adsorption by sewage sludge-derived biochar in biochar-amended soils.

    Science.gov (United States)

    Zielińska, Anna; Oleszczuk, Patryk

    2016-11-01

    The aim of this study was to evaluate the effect of soils on the sorption of phenanthrene (PHE) and pyrene (PYR) by sewage sludge-derived biochars (SS-derived biochars). The SS-derived biochars were added to soils with varying properties as well as with a different degree and source of polycyclic aromatic hydrocarbons (PAHs) contamination. The biochars (BCs) were produced from sewage sludge during pyrolysis at temperatures of 500 °C (BC500) and 700 °C (BC700). The addition of biochars to the soils (5 %, w/w) increased the sorption of PHE from 8.3 to 20.3 % and PYR from 14.5 to 31.7 % by amended soil. BC700 biochar was characterized by better sorption capacity than BC500 biochar. Nevertheless, the presence of soil reduces the effectiveness of biochars in binding the compounds studied. The sorption capacity of the biochars decreased several times after they had been mixed with the soil compared to pure biochars. The study found dissolved organic carbon (DOC) and clay minerals present in the soils to have a significant effect on reducing the efficiency of PHE and PYR sorption by biochar. A greater impact of fouling was observed in the case of BC500 biochar characterized by lower porosity than BC700 biochar.

  20. The Protective Effect of Dietary Arthrospira (Spirulina) maxima Against Mutagenicity Induced by Benzo[alpha]pyrene in Mice

    Science.gov (United States)

    Garduño-Siciliano, Leticia; Martínez-Galero, Elizdath; Mojica-Villegas, Angélica; Pages, Nicole; Gutiérrez-Salmeán, Gabriela

    2014-01-01

    Abstract Benzo[alpha]pyrene (B[α]P) was used to test the possible antimutagenic effects of Arthrospira (Spirulina) maxima (SP) on male and female mice. SP was orally administered at 0, 200, 400, or 800 mg/kg of body weight to animals of both sexes for 2 weeks before starting the B[α]P (intraperitoneal injection) at 125 mg/kg of body weight for 5 consecutive days. For the male dominant lethal test, each male was caged with two untreated females per week for 3 weeks. For the female dominant lethal test, each female was caged for 1 week with one untreated male. All the females were evaluated 13–15 days after mating for incidence of pregnancy, total corpora lutea, total implants and pre- and postimplant losses. SP protected from B[α]P-induced pre- and postimplant losses in the male dominant lethal test, and from B[α]P-induced postimplantation losses in treated females. Moreover, SP treatment significantly reduced the detrimental effect of B[α]P on the quality of mouse semen. Our results illustrate the protective effects of SP in relation to B[α]P-induced genetic damage to germ cells. We conclude that SP, owing mainly to the presence of phycocyanin, could be of potential clinical interest in cancer treatment or prevention of relapse. PMID:24787733

  1. Relation of hepatic EROD activity and CYP1A level in Sebastiscus marmoratus exposed to benzo[a]pyrene

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    This study was designed to investigate the in vivo effects of benzo[a]pyrene (BaP) on hepatic ethoxyresorufin-O-deethylase (EROD) activity and its correlation with cytochrome P450 1A (CYP1A) protein levels in Sebastiscus marmoratus, which were exposed through a water column to BaP (10, 100, 1000 ng/L, respectively) or were treated with intraperitoneal injections of BaP (0.5, 1, 5, 10 mg/kg, respectively) every 7 d. The results showed that after 25 d of waterborne exposure to 1000 ng/L BaP, fish hepatic CYP1A levels and EROD activity were significantly induced. In contrast, EROD activity was not altered 7 d after second ip injections, whereas, CYP1A protein levels were increased. Dose-dependent increase of biliary BaP metabolites demonstrated that the catalytic activity of CYP1A was induced by treatment with BaP. The lowest observable effect concentration with regard to biliary BaP metabolites (100 ng/L) was much lower than that with reference to EROD activity (1000 ng/L). The results suggest that biliary polycyclic aromatic hydrocarbon (PAH) metabolites were shown to better reflect the contamination gradients of PAHs than EROD activity. It appeared to be necessary to measure CYP1A protein levels to complement the EROD activity in relevant toxicological assessments.

  2. Phenanthrene and Pyrene Modify the Composition and Structure of the Cultivable Endophytic Bacterial Community in Ryegrass (Lolium multiflorum Lam

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    Xuezhu Zhu

    2016-11-01

    Full Text Available This study provides new insights into the dynamics of bacterial community structure during phytoremediation. The communities of cultivable autochthonous endophytic bacteria in ryegrass exposed to polycyclic aromatic hydrocarbons (PAHs were investigated with regard to their potential to biodegrade PAHs. Bacterial counts and 16S rRNA gene sequence were used in the microbiological evaluation. A total of 33 endophytic bacterial strains were isolated from ryegrass plants, which represented 15 different genera and eight different classes, respectively. Moreover, PAH contamination modified the composition and structure of the endophytic bacterial community in the plants. Bacillus sp., Pantoea sp., Pseudomonas sp., Arthrobacter sp., Pedobacter sp. and Delftia sp. were only isolated from the seedlings exposed to PAHs. Furthermore, the dominant genera in roots shifted from Enterobacter sp. to Serratia sp., Bacillus sp., Pantoea sp., and Stenotrophomonas sp., which could highly biodegrade phenanthrene (PHE. However, the diversity of endophytic bacterial community was decreased by exposure to the mixture of PAHs, and increased by respective exposure to PHE and pyrene (PYR, while the abundance was increased by PAH exposure. The results clearly indicated that the exposure of plants to PAHs would be beneficial for improving the effectiveness of phytoremediation of PAHs.

  3. Enhancement of the genotoxicity of benzo[a]pyrene by arecoline through suppression of DNA repair in HEp-2 cells.

    Science.gov (United States)

    Huang, J L; Lu, H H; Lu, Y N; Hung, P S; Lin, Y J; Lin, C C; Yang, C C; Wong, T Y; Lu, S Y; Lin, C S

    2016-06-01

    The International Agency for Research on Cancer lists the principal component of betel quid (BQ), the areca nut, and that of cigarette smoke, benzo[a]pyrene (BaP), as Group 1 carcinogens. Epidemiological studies have shown that coexposure of BQ and cigarette smoke markedly increases the risk of cancer. We previously demonstrated that arecoline, the most abundant alkaloid in the areca nut, inhibits nucleotide excision repair through the repression of p53 activity. To investigate the combined potency of arecoline and BaP in carcinogenesis, we treated human epithelial HEp-2 cells with subcytotoxic doses of arecoline and BaP, alone or in combination, and examined the effects on DNA damage and repair. When exposed for 24h, BaP enhanced DNA repair and p53 transactivation activity. However, these enhancements were suppressed through concurrent treatment of the cells with arecoline. Using a Comet assay, we found that extended exposure to arecoline and BaP caused moderate-to-severe DNA damage in 60% of the cells. Expression of the XPD helicase was transcriptionally suppressed by 1 week of treatment with BaP. Our studies have revealed potential targets in the DNA repair pathway that are affected by BQ and tobacco components, as well as the effect of these components on carcinogenesis. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Characteristics of copper removal and ion release during copper biosorption by Stenotrophomonas maltophilia in presence of benzo[a]pyrene

    Institute of Scientific and Technical Information of China (English)

    田云; 叶锦韶; 尹华; 彭辉; 李取生; 白洁琼; 谢丹平

    2013-01-01

    The ability of Stenotrophomonas maltophilia was demonstrated to selectively remove Cu2+from Cu(NO3)2 solution under the circumstance that 1 mg/L benzo[a]pyrene(BaP) was either present or not. The removal ratios of 2 and 10 mg/L Cu2+by 0.25 g/L biosorbent are up to 80% and 49% at 10 min, respectively. The biosorption includes ion exchange, NO3 reduction, ion release, and cell oxidation by Cu2+. BaP does not significantly affect Cu2+removal and ion release. Although 2 mg/L Cu2+increases the release of PO4 3, K+, NH4 +and Ca2+, 10 mg/L Cu2+has strong oxidation on cell, and then decreases NO3 reduction and hinders the release of K+, NH4 +and Ca2+. Exogenous cations inhibit the Cu2+biosorption, while additional anions increase the removal ratios of 10 mg/L Cu2+from 52% to 88%.

  5. Dose-dependent inhibitory effect of melatonin on carcinogenesis induced by benzo[a]pyrene in mice.

    Science.gov (United States)

    Vesnushkin, G M; Plotnikova, N A; Semenchenko, A I; Anisimov, V N

    2006-12-01

    Three-month-old Swiss-derived SHR mice were subcutaneously injected with 2 mg of benzo[a]pyrene (BP) dissolved in 0.1 ml of olive oil. After the injections of the carcinogen two groups of mice were given melatonin with night drinking water at the doses of 2 mg/l or 20 mg/l and one group of mice was not treated with melatonin and served as a PB-control. At the 28th week after the carcinogen administration the experiment was stopped and animals were sacrificed. The results show that melatonin treatment inhibits BP-induced carcinogenesis, decreases the incidence of subcutaneous sarcomas, increases their latency and survival of mice. The malone dialdehyde (MDA) level in the serum of BP-induced tumor-bearing mice was increased by 2.6 times (p melatonina on malignancies of mesenchymal origin. Lower dose of melatonin appeared to be more effective in the inhibition of lipid peroxidation and tumorigenesis induced by chemical carcinogen than a higher one.

  6. Effect of Soil Aging on the Phytoremediation Potential of Zea mays in Chromium and Benzo[a]Pyrene Contaminated Soils.

    Science.gov (United States)

    Chigbo, Chibuike

    2015-06-01

    This study compared the phytoremediation potential of Zea mays in soil either aged or freshly amended with chromium (Cr) and benzo[a]pyrene (B[a]P). Z. mays showed increased shoot biomass in aged soils than in freshly spiked soils. The shoot biomass in contaminated soils increased by over 50% in aged soil when compared to freshly amended soils, and over 29% more Cr was accumulated in the shoot of Z. mays in aged soil than in freshly amended soil. Planting Z. mays in aged soil helped in the dissipation of more than 31% B[a]P than in freshly spiked soil, but in the absence of plants, there seemed to be no difference between the dissipation rates of B[a]P in freshly and aged co-contaminated soil. Z. mays seemed to enhance the simultaneous removal of Cr and B[a]P in aged soil than in freshly spiked soil and hence can be a good plant choice for phytoremediation of co-contaminated soils.

  7. Bright and photostable push-pull pyrene dye visualizes lipid order variation between plasma and intracellular membranes

    Science.gov (United States)

    Niko, Yosuke; Didier, Pascal; Mely, Yves; Konishi, Gen-Ichi; Klymchenko, Andrey S.

    2016-01-01

    Imaging lipid organization in cell membranes requires advanced fluorescent probes. Here, we show that a recently synthesized push-pull pyrene (PA), similarly to popular probe Laurdan, changes the emission maximum as a function of lipid order, but outperforms it by spectroscopic properties. In addition to red-shifted absorption compatible with common 405 nm diode laser, PA shows higher brightness and much higher photostability than Laurdan in apolar membrane environments. Moreover, PA is compatible with two-photon excitation at wavelengths >800 nm, which was successfully used for ratiometric imaging of coexisting liquid ordered and disordered phases in giant unilamellar vesicles. Fluorescence confocal microscopy in Hela cells revealed that PA efficiently stains the plasma membrane and the intracellular membranes at >20-fold lower concentrations, as compared to Laurdan. Finally, ratiometric imaging using PA reveals variation of lipid order within different cellular compartments: plasma membranes are close to liquid ordered phase of model membranes composed of sphingomyelin and cholesterol, while intracellular membranes are much less ordered, matching well membranes composed of unsaturated phospholipids without cholesterol. These differences in the lipid order were confirmed by fluorescence lifetime imaging (FLIM) at the blue edge of PA emission band. PA probe constitutes thus a new powerful tool for biomembrane research.

  8. Manufacture of low-benzo(a)pyrene sesame seed (Sesamum indicum L.) oil using a self-designed apparatus.

    Science.gov (United States)

    Yi, Ji Yoon; Kim, Hui Ju; Chung, Myong-Soo

    2017-01-01

    The aim of this study was to lower benzo(a)pyrene (BaP) contents in sesame seed oil (SSO) during manufacture by using a self-designed apparatus, to determine its optimal conditions, and to analyze antioxidants in SSO which might be related to BaP content reduction. Washing and spin-drying steps reduce exogenous BaP contamination, and the reduced moisture in seeds lowered BaP content in final SSO. A ventilation system in the roasting step inhibits BaP formation and reabsorption, followed by a controlled compression step. The optimal condition, a single washing cycle with 2-min spin-drying, 1350-rpm ventilation, and a single compression cycle, reduced the BaP content in SSO to 2.93 μg/kg, where the raw seeds had been spiked with 10-μg/kg BaP. Total phenolic contents showed a reversal pattern to the distribution of BaP contents. Sesamol and sesamolin were quantified by a high performance liquid chromatography-ultraviolet detector, and it was suggested that sesamol which is a strong antioxidant might have prevented BaP formation during the roasting step. This study enabled the commercial production of low-BaP SSO, and the data could be used in further investigations of the BaP content reduction mechanism with quantitative chemical analysis of the SSO composition.

  9. Antioxidant and antitumor efficacy of Luteolin, a dietary flavone on benzo(a)pyrene-induced experimental lung carcinogenesis.

    Science.gov (United States)

    Kasala, Eshvendar Reddy; Bodduluru, Lakshmi Narendra; Barua, Chandana C; Gogoi, Ranadeep

    2016-08-01

    The present study is designed to assess the antioxidant and antitumor potential of luteolin against benzo(a)pyrene [B(a)P]-induced lung carcinogenesis in Swiss albino mice. Here, we reported that oral administration of B(a)P (50mg/kg body weight) to mice resulted in raised lipid peroxides (LPO), lung specific tumor markers such as carcinoembryonic antigen (CEA) and neuron specific enolase (NSE) with concomitant decrease in the levels of both enzymatic antioxidants such as superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPx) and glutathione-s-transferase (GST), and non-enzymatic antioxidants such as reduced glutathione (GSH), vitamin E and vitamin C. Luteolin treatment (15mg/kg body weight, p.o) significantly counteracted all these alterations and maintained cellular normalcy. Moreover, assessment of protein expression levels by western blot analysis revealed that luteolin treatment effectively negates B(a)P-induced upregulated expression of proliferating cell nuclear antigen (PCNA), cytochrome P450 1A1 (CYP1A1) and nuclear factor-kappa B (NF-κB). Furthermore, histopathology of lung tissue and immunohistochemistry of CYP1A1 were carried out to substantiate the anti- lung cancer effect of luteolin. Overall, these findings confirm the chemopreventive potential of luteolin against B(a)P induced lung carcinogenesis.

  10. A gene expression study of the activities of aromatic ring-cleavage dioxygenases in Mycobacterium gilvum PYR-GCK to changes in salinity and pH during pyrene degradation.

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    Abimbola Comfort Badejo

    Full Text Available Polycyclic aromatic hydrocarbons (PAHs are toxic pollutants found in the environment which can be removed through the use of physical and biological agents. The rate of PAH biodegradation is affected by environmental conditions of pH, salinity and temperature. Adaptation of the pyrene degrading bacteria, Mycobacterium gilvum PYR-GCK, to fluctuating environmental conditions during pyrene biodegrading activity was studied using the quantitative real time - Polymerase Chain Reaction (qRT-PCR technique. Four aromatic ring-cleavage dioxygenase genes: phdF, phdI, pcaG and pcaH; critical to pyrene biodegradation, were studied in pH states of 5.5, 6.5, 7.5 and NaCl concentrations 0 M, 0.17 M, 0.5 M, 0.6 M, 1 M. First, we conducted a residual pyrene study using gas chromatography and flame ionization technologies. Central to a gene expression study is the use of a valid endogenous reference gene, making its determination our next approach, using the geNorm/NormFinder algorithms. Armed with a valid control gene, rpoB, we applied it to a gene expression study, using the comparative critical threshold (2(ΔΔCT quantification method. The pyrene degrading activity of the strain was strongly functional in all the NaCl concentration states, with the least activity found at 1M (∼70% degraded after 48 hours of cultivation. The transcripts quantification of three genes backed this observation with high expression levels. The gene expression levels also revealed pH 6.5 as optimal for pyrene degradation and weak degradation activity at pH of 5.5, corroborating the residual pyrene analysis. The expression of these genes as proteins has already been studied in our laboratory using proteomics techniques and this validates our current study.

  11. Genetic polymorphisms in biotransformation enzymes for benzo[a]pyrene and related levels of benzo[a]pyrene-7,8-diol-9,10-epoxide-DNA adducts in Goeckerman therapy.

    Science.gov (United States)

    Beranek, Martin; Fiala, Zdenek; Kremlacek, Jan; Andrys, Ctirad; Hamakova, Kvetoslava; Chmelarova, Marcela; Palicka, Vladimir; Borska, Lenka

    2016-07-25

    Goeckerman therapy (GT) for psoriasis combines the therapeutic effect of crude coal tar (CCT) and ultraviolet radiation (UVR). CCT contains polycyclic aromatic hydrocarbons, some of which can form DNA adducts that may induce mutations and contribute to carcinogenesis. The aim of our work was to evaluate the relationship between concentrations of benzo[a]pyrene-7,8-diol-9,10-epoxide-DNA adducts (BPDE-DNA adducts) and rs4646903 (CYP1A1 gene), rs1048943 (CYP1A1), rs1056836 (CYP1B1), rs1051740 (EPHX1), rs2234922 (EPHX1) and rs8175347 (UGT1A1) polymorphic sites, and GSTM1 null polymorphism in 46 patients with chronic stable plaque psoriasis who underwent GT. The level of BPDE-DNA adducts was determined using the OxiSelect BPDE-DNA Adduct ELISA Kit. Polymerase chain reaction (PCR) and restriction fragment length polymorphism analysis (rs4646903, rs1048943, rs1051740, and rs2234922), fragment analysis (rs8175347), real-time PCR (rs1056836), and digital droplet PCR polymorphism (GSTM1) were used. CYP1B1*1/*1 wild-type subjects and CYP1B1*3/*1 heterozygotes for rs1056836 formed significantly higher amounts of BPDE-DNA adducts than CYP1B1*3/*3 homozygotes (p=0.031 and p=0.005, respectively). Regarding rs1051740, individuals with EPHX1*3/*1 heterozygosity revealed fewer adducts than EPHX1*1/*1 wild-type subjects (p=0.026). Our data suggest that CYP1B1/EPHX1 genotyping could help to predict the risk of DNA damage and to optimize doses of coal tar and UVR exposure in psoriatic patients in whom GT was applied.

  12. The arbuscular mycorrhizal Rhizophagus irregularis activates storage lipid biosynthesis to cope with the benzo[a]pyrene oxidative stress.

    Science.gov (United States)

    Calonne, Maryline; Fontaine, Joël; Debiane, Djouher; Laruelle, Frédéric; Grandmougin-Ferjani, Anne; Lounès-Hadj Sahraoui, Anissa

    2014-01-01

    The phytoremediation assisted by arbuscular mycorrhizal fungi (AMF) could constitute an ecological and economic method to restore polycyclic aromatic hydrocarbon (PAH) polluted soils. Unfortunately, little is known about the PAH impact on the beneficial symbiotic AMF. Using radiolabelling experiments, our work aims to understand how benzo[a]pyrene (B[a]P), a representative of high molecular weight PAH, acts on the AMF lipid metabolism. Our results showed decreases in the sterol precursors as well as in total phospholipid quantities, in link with the [1-(14)C]acetate incorporation decreases in these lipids. Interestingly, a concomitant increase of [1-(14)C]acetate incorporation by 29.5% into phosphatidylcholine with its content decrease in Rhizophagus irregularis extraradical mycelium was observed, suggesting a membrane regeneration. A second concomitant increase (estimated to 69%) of [1-(14)C]acetate incorporation into triacylglycerols (TAG) with the content decrease was also observed. This suggests a fungal TAG biosynthesis activation probably to offset the decrease in storage lipid content when the fungus was grown under B[a]P pollution. In addition, our findings showed that lipase activity was induced by more than 3 fold in the presence of B[a]P in comparison to the control indicating that the drop in TAG content could be a consequence of their active degradation. Taken together, our data suggest the involvement of the fungal TAG metabolism to cope B[a]P toxicity through two means: (i) by providing carbon skeletons and energy necessary for membrane regeneration and/or for B[a]P translocation and degradation as well as (ii) by activating the phosphatidic acid and hexose metabolisms which may be involved in cellular stress defence. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Exome-wide Mutation Profile in Benzo[a]pyrene-derived Post-stasis and Immortal Human Mammary Epithelial Cells

    Science.gov (United States)

    Severson, Paul L.; Vrba, Lukas; Stampfer, Martha R.; Futscher, Bernard W.

    2014-01-01

    Genetic mutations are known to drive cancer progression and certain tumors have mutation signatures that reflect exposures to environmental carcinogens. Benzo[a]pyrene (BaP) has a known mutation signature and has proven capable of inducing changes to DNA sequence that drives normal pre-stasis human mammary epithelial cells (HMEC) past a first tumor suppressor barrier (stasis) and towards immortality. We analyzed normal, pre-stasis HMEC, three independent BaP-derived post-stasis HMEC strains (184Aa, 184Be, 184Ce) and two of their immortal derivatives(184A1 and 184BE1) by whole exome sequencing. The independent post-stasis strains exhibited between 93 and 233 BaP-induced mutations in exons. Seventy percent of the mutations were C:G>A:T transversions, consistent with the known mutation spectrum of BaP. Mutations predicted to impact protein function occurred in several known and putative cancer drivers including p16, PLCG1, MED12, TAF1 in 184Aa; PIK3CG, HSP90AB1, WHSC1L1, LCP1 in 184Be and FANCA, LPP in 184Ce. Biological processes that typically harbor cancer driver mutations such as cell cycle, regulation of cell death and proliferation, RNA processing, chromatin modification and DNA repair were found to have mutations predicted to impact function in each of the post-stasis strains. Spontaneously immortalized HMEC lines derived from two of the BaP-derived post-stasis strains shared greater than 95% of their BaP-induced mutations with their precursor cells. These immortal HMEC had 10 or fewer additional point mutations relative to their post-stasis precursors, but acquired chromosomal anomalies during immortalization that arose independent of BaP. The results of this study indicate that acute exposures of HMEC to high dose BaP recapitulate mutation patterns of human tumors and can induce mutations in a number of cancer driver genes. PMID:25435355

  14. Effect of benzo[a]pyrene on detoxification and the activity of antioxidant enzymes of marine microalgae

    Science.gov (United States)

    Shen, Chen; Miao, Jingjing; Li, Yun; Pan, Luqing

    2016-04-01

    The objective of this study was to examine the effect of benzo[a]pyrene (BaP) on the detoxification and antioxidant systems of two microalgae, Isochrysis zhanjiangensis and Platymonas subcordiformis. In our study, these two algae were exposed to BaP for 4 days at three different concentrations including 0.5 μg L-1 (low), 3 μg L-1 (mid) and 18 μg L-1 (high). The activity of detoxification enzymes, ethoxyresorufin O-deethylase (EROD) and glutathione S-transferase (GST) increased in P. subcordiformis in all BaP-treated groups. In I. zhanjiangensis, the activity of these two enzymes increased at the beginning of exposure, and then decreased in the groups treated with mid- and high BaP. The activity of antioxidant enzyme superoxide dismutase (SOD) increased in I. zhanjiangensis in all BaP-treated groups, and then decreased in high BaP-treated group, while no significant change was observed in P. subcordiformis. The activity of antioxidant enzyme catalase (CAT) increased in I. zhanjiangensis and P. subcordiformis in all BaPtreated groups. The content of malondialdehyde (MDA) in Isochrysis zhanjiangensis increased first, and then decreased in high BaP-treated group, while no change occurred in P. subcordiformis. These results demonstrated that BaP significantly influenced the activity of detoxifying and antioxidant enzymes in microalgae. The metabolic related enzymes (EROD, GST and CAT) may serve as sensitive biomarkers of measuring the contamination level of BaP in marine water.

  15. Hesperidin attenuates benzo[alpha] pyrene-induced testicular toxicity in rats via regulation of oxidant/antioxidant balance.

    Science.gov (United States)

    Arafa, H M M; Aly, H A A; Abd-Ellah, M F; El-Refaey, H M

    2009-07-01

    Benzo[alpha]pyrene (BaP) is one of the polycyclic aromatic hydrocarbons, which has shown carcinogenic, teratogenic, and mutagenic potentials. The reproductive toxicity of BaP in male was not well investigated. Thereby, we have addressed in the current study the testicular toxicity of BaP and the postulate whether or not the citrus flavonoid, hesperidin (HDN), could ameliorate such toxicity in male Swiss albino rats. In this sense, animals were challenged with BaP (50 mg/kg/day, orally) for 10 consecutive days. HDN (200 mg/kg/day, orally) was administered ahead of BaP challenge for 10 consecutive days. BaP induced testicular toxicity that was well characterized histologically and biochemically. It decreased the relative testis weight and induced pyknosis and necrobiotic changes as well as chromatolysis in the nuclei of the spermatocytes in the seminiferous tubules. It also markedly deteriorated epididymal function as shown by decreased sperm count, motility, and daily sperm production. The polyaromatic hydrocarbon also reduced the testicular activities of lactate dehydrogenase (LDH-X), superoxide dismutase (SOD), and glutathione-S-transferase (GST). Besides, it decreased the testicular reduced glutathione (GSH) but increased malondialdehyde (MDA) contents. Prior administration of HDN ahead of BaP challenge ameliorated all the histological and biochemical alterations induced by BaP. It improved the epididymal function and mitigated the injurious effects of BaP on the seminiferous tubules. In conclusion, HDN has proven protective effects in BaP-induced testicular toxicity paradigm, and this protection resides, at least in part, on its antioxidant properties.

  16. Menadione Suppresses Benzo(α)pyrene-Induced Activation of Cytochromes P450 1A: Insights into a Possible Molecular Mechanism.

    Science.gov (United States)

    Sidorova, Yulia A; Perepechaeva, Maria L; Pivovarova, Elena N; Markel, Arkady L; Lyakhovich, Vyacheslav V; Grishanova, Alevtina Y

    2016-01-01

    Oxidative reactions that are catalyzed by cytochromes P450 1A (CYP1A) lead to formation of carcinogenic derivatives of arylamines and polycyclic aromatic hydrocarbons (PAHs), such as the widespread environmental pollutant benzo(α)pyrene (BP). These compounds upregulate CYP1A at the transcriptional level via an arylhydrocarbon receptor (AhR)-dependent signaling pathway. Because of the involvement of AhR-dependent genes in chemically induced carcinogenesis, suppression of this signaling pathway could prevent tumor formation and/or progression. Here we show that menadione (a water-soluble analog of vitamin K3) inhibits BP-induced expression and enzymatic activity of both CYP1A1 and CYP1A2 in vivo (in the rat liver) and BP-induced activity of CYP1A1 in vitro. Coadministration of BP and menadione reduced DNA-binding activity of AhR and increased DNA-binding activity of transcription factors Oct-1 and CCAAT/enhancer binding protein (C/EBP), which are known to be involved in negative regulation of AhR-dependent genes, in vivo. Expression of another factor involved in downregulation of CYP1A-pAhR repressor (AhRR)-was lower in the liver of the rats treated with BP and menadione, indicating that the inhibitory effect of menadione on CYP1A is not mediated by this protein. Furthermore, menadione was well tolerated by the animals: no signs of acute toxicity were detected by visual examination or by assessment of weight gain dynamics or liver function. Taken together, our results suggest that menadione can be used in further studies on animal models of chemically induced carcinogenesis because menadione may suppress tumor formation and possibly progression.

  17. Menadione Suppresses Benzo(αpyrene-Induced Activation of Cytochromes P450 1A: Insights into a Possible Molecular Mechanism.

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    Yulia A Sidorova

    Full Text Available Oxidative reactions that are catalyzed by cytochromes P450 1A (CYP1A lead to formation of carcinogenic derivatives of arylamines and polycyclic aromatic hydrocarbons (PAHs, such as the widespread environmental pollutant benzo(αpyrene (BP. These compounds upregulate CYP1A at the transcriptional level via an arylhydrocarbon receptor (AhR-dependent signaling pathway. Because of the involvement of AhR-dependent genes in chemically induced carcinogenesis, suppression of this signaling pathway could prevent tumor formation and/or progression. Here we show that menadione (a water-soluble analog of vitamin K3 inhibits BP-induced expression and enzymatic activity of both CYP1A1 and CYP1A2 in vivo (in the rat liver and BP-induced activity of CYP1A1 in vitro. Coadministration of BP and menadione reduced DNA-binding activity of AhR and increased DNA-binding activity of transcription factors Oct-1 and CCAAT/enhancer binding protein (C/EBP, which are known to be involved in negative regulation of AhR-dependent genes, in vivo. Expression of another factor involved in downregulation of CYP1A-pAhR repressor (AhRR-was lower in the liver of the rats treated with BP and menadione, indicating that the inhibitory effect of menadione on CYP1A is not mediated by this protein. Furthermore, menadione was well tolerated by the animals: no signs of acute toxicity were detected by visual examination or by assessment of weight gain dynamics or liver function. Taken together, our results suggest that menadione can be used in further studies on animal models of chemically induced carcinogenesis because menadione may suppress tumor formation and possibly progression.

  18. Dose-related carcinogenic effects of water-borne benzo(a)pyrene on livers of two small fish species

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    Hawkins, W.E.; Walker, W.W.; Overstreet, R.M.; Lytle, T.F.; Lytle, J.S.

    1988-12-01

    Benzo(a)pyrene (BaP) administered by water-borne exposures caused dose-related carcinogenic effects in livers of two small fish species, the Japanese medaka (Oryzias latipes) and the guppy (Poecilia reticulata). Medaka and guppies each were given two 6-h exposures. The first exposure was conducted on 6- to 10-day-old specimens. The second exposure was given 7 days later. The tests incorporated five treatment groups: (1) control, (2) carrier (dimethylformamide) control, (3) low BaP dose (not detectable--4 ppb), (4) intermediate BaP dose (about 8-47 ppb BaP), and (5) high BaP dose (200-270 ppb). Following the high-dose exposure, hepatocellular lesions classified as foci of cellular alteration (altered foci), adenomas, and hepatocellular carcinomas occurred in both species. In medaka, the lesions appeared to develop sequentially with the appearance of altered foci followed by adenomas and then hepatocellular carcinomas. Most lesions in guppies, however, were classified as altered foci although a few adenomas occurred in the early (24-week) sample and hepatocellular carcinomas occurred in the late (52-week) sample. When total lesions were combined, medaka had an 11% incidence at 24 weeks after the initial exposure and 36% incidence at 36 weeks. In guppies, 8% had liver lesions at 24 weeks, 19% at 36 weeks, and 20% at 52 weeks. A single extrahepatic neoplasm, a capillary hemangioma in a gill filament, occurred in a medaka from the 36-week high-dose sample. The results suggest that the medaka and guppy are capable of metabolizing water-borne BaP to carcinogenic metabolites which initiate hepatic tumor development.

  19. Adsorption and partition of benzo(a)pyrene on sediments with different particle sizes from the Yellow River

    Institute of Scientific and Technical Information of China (English)

    XIA Xinghui; MENG Lihong; HU Lijuan

    2007-01-01

    Experiments have been carried out to study the sorption of Benzo(a)pyrene(Bap)on sediment particles from the Yellow River using a batch equilibration technique,Effects of particle size on the adsorption and partition of Bap were investigated with the particle content Of 3 g/L.Several significant results were obtained from the stttdy.(1)Isotherms of Bap could be fired with the dual adsorption-partition model under different particle sizes,and the measured value of the adsorption and partition was in agreement with the theoretical value of the dual adsorption-partition model.(2)When the particle diameter was d≥0.025 mm,the adsorption was predominant in the sorption of Bap,which accounted for 68.7%-82.4% of the sorption.For the particles with the size Of 0.007 mm≤d<0.025 mm,the adsorption was predominant when the equilibrium concentration of Bap was 0-8.87μg/L in the water phase;and the partition was predominant when the equilibrium concentratioh of Bap was higher than 8.87μg/L in the water phase.When the particle diameter was d<0.007 mm,the partition was predominant.(3)On the point of particle size,the contribution of adsorption to sorption followed the order:"d≥0.025 mm">"0.007 mm ≤d<0.025 mm">"d<0.007 mm".(4)The partition coefficients of Bap in solids with different particle sizes were Iinearly correlated with the organic content,and the Koc of Bap was about 1.26×105(L/kg).

  20. Chronic exposure to low benzo[a]pyrene level causes neurodegenerative disease-like syndromes in zebrafish (Danio rerio).

    Science.gov (United States)

    Gao, Dongxu; Wu, Meifang; Wang, Chonggang; Wang, Yuanchuan; Zuo, Zhenghong

    2015-10-01

    Previous epidemiological and animal studies report that exposure to environmental pollutant exposure links to neurodegenerative diseases such as Parkinson's disease and Alzheimer's disease. Benzo[a]pyrene (BaP), a neurotoxic polycyclic aromatic hydrocarbon, has been increasingly released into the environment during recent decades. So far, the role of BaP on the development of neurodegenerative diseases remaind unclear. This study aimed to determine whether chronic exposure to low dose BaP would cause neurodegenerative disease-like syndromes in zebrafish (Danio rerio). We exposed zebrafish, from early embryogenesis to adults, to environmentally relevant concentrations of BaP for 230 days. Our results indicated that BaP decreased the brain weight to body weight ratio, locomotor activity and cognitive ability; induced the loss of dopaminergic neurons; and resulted in neurodegeneration. In addition, obvious cell apoptosis in the brain was found. Furthermore, the neurotransmitter levels of dopamine and 3,4-dihydroxyphenylacetic acid, the mRNA levels of the genes encoding dopamine transporter, Parkinson protein 7, phosphatase and tensin-induced putative kinase 1, ubiquitin carboxy-terminal hydrolase L1, leucine-rich repeat serine/threonine kinase 2, amyloid precursor protein b, presenilin 1 and presenilin 2 were significantly down-regulated by BaP exposure. These findings suggest that chronic exposure to low dose BaP could cause the behavioral, neuropathological, neurochemical, and genetic features of neurodegenerative diseases. This study provides clues that BaP may constitute an important environmental risk factor for neurodegenerative diseases in humans.

  1. BENZO[a]PYRENE DIOL EPOXIDE PERTURBATION OF CELL CYCLE KINETICS OF SYNCHRONIZED MOUSE LIVER EPITHELIAL CELLS

    Energy Technology Data Exchange (ETDEWEB)

    Pearlman, A.L.; Navsky, B.N.; Bartholomew, J.C

    1980-07-01

    A cell cycle synchronization system is described for the analysis of the perturbation of cell cycle kinetics and the cycle-phase specificity of chemicals and other agents. We used the system to study the effects of ({+-})r-7, t-8-dihydroxy-t-9, 10-oxy-7,8,9,10-tetrahydrobenzo[a]pyrene (BaP diol epoxide) upon the cell cycle of mouse liver epithelial cells(NMuLi). BaP diol epoxide(0.6 uM) was added to replated cultures of NMuLi cells that had been synchronized in various stages of the cell cycle by centrifugal elutriation. DNA histograms were obtained by flow cytometry as a function of time after replating. The data were analyzed by a computer modeling routine and reduced to a few graphs illustrating the 'net effects' of the BaP diol epoxide relative to controls. BaP diol epoxide slowed S-phase traversal in all samples relative to their respective control. Traversal through G{sub 2}M was also slowed by at least 50%. BaP diol epoxide had no apparent effect upon G{sub 1} traversal by cycling cells, but delayed the recruitment of quiescent G{sub 0} cells by about 2 hrs. The methods described constitute a powerful new approach for probing the cell cycle effects of a wide variety of agents. The present system appears to be extremely sensitive and capable of characterizing the action of agents on each phase of the cell cycle. The methods are automatable and would allow for the assay and possible differential characterization of mutagens and carcinogens.

  2. Benzo-α-pyrene induced oxidative stress in Caenorhabditis elegans and the potential involvements of microRNA.

    Science.gov (United States)

    Wu, Hongmei; Huang, Chenping; Taki, Faten A; Zhang, Yanqiong; Dobbins, Dorothy L; Li, Lin; Yan, Hongtao; Pan, Xiaoping

    2015-11-01

    In the present study oxidative stress induced by Benzo-α-pyrene (BaP) exposure and the potential involvements of microRNA were investigated. The Caenorhabditis elegans (C. elegans) was applied as model organism. The C. elegans at L1-stage were randomly divided into 4 groups and exposed to 0, 0.2, 2.0, and 20μM BaP for 30h. Expressions of SKiNhead-1 (SKN-1), gamma-glutamine cysteine synthase heavy chain (GCS-1), and their potential regulatory factors in insulin/IGF-1/FOXO signaling pathway and the p38 MAPK pathway were analyzed. The expressions of potentially involved microRNAs were investigated as well. Results demonstrated that expressions of SKN-1 and GCS-1 were altered significantly following BaP exposure (P<0.05). Meanwhile, expressions of multiple related factors were changed after BaP treatments. The altered factors include AKT-1, DAF-16, glutathione synthetase (GSS-1), glutathione S-transferase-24 (GST-24), mitogen-activated protein kinase kinase-4 (MKK-4), multidrug resistance-associated protein-1 (MRP-1), and pyruvate dehydrogenase kinase-2 (PDHK-2) (P<0.05). In addition, results showed that exposure to BaP led to altered expressions of microRNA. Out of the 28 tested microRNAs, expressions of miR-1, miR-355, miR-50, miR-51, miR-58, miR-796, miR-797, and miR-84 were modified. Findings of the present study include that BaP exposure caused oxidative stress in C. elegans. The expressional response of GCS-1 to BaP exposure might be independent of the regulation of SKN-1 in C. elegans. The microRNAs might be involved in the regulations of SKN-1 and GCS-1 expression following BaP exposure in C. elegans.

  3. Genetic polymorphisms in catalase and CYP1B1 determine DNA adduct formation by benzo(a)pyrene ex vivo.

    Science.gov (United States)

    Schults, Marten A; Chiu, Roland K; Nagle, Peter W; Wilms, Lonneke C; Kleinjans, Jos C; van Schooten, Frederik J; Godschalk, Roger W

    2013-03-01

    Genetic polymorphisms can partially explain the large inter-individual variation in DNA adduct levels following exposure to polycyclic aromatic hydrocarbons. Effects of genetic polymorphisms on DNA adduct formation are difficult to assess in human studies because exposure misclassification attenuates underlying relationships. Conversely, ex vivo studies offer the advantage of controlled exposure settings, allowing the possibility to better elucidate genotype-phenotype relationships and gene-gene interactions. Therefore, we exposed lymphocytes of 168 non-smoking volunteers ex vivo to the environmental pollutant benzo(a)pyrene (BaP) and BaP-related DNA adducts were quantified. Thirty-four genetic polymorphisms were assessed in genes involved in carcinogen metabolism, oxidative stress and DNA repair. Polymorphisms in catalase (CAT, rs1001179) and cytochrome P450 1B1 (CYP1B1, rs1800440) were significantly associated with DNA adduct levels, especially when combined. Moreover, reverse transcription-polymerase chain reaction (RT-PCR) analysis in a subset of 30 subjects revealed that expression of catalase correlated strongly with expression of CYP1B1 (R = 0.92, P CYP1B1 and how they simultaneously affect BaP-related DNA adduct levels, catalase expression was transiently knocked down in the human lung epithelial cell line A549. Although catalase knockdown did not immediately change CYP1B1 gene expression, recovery of catalase expression 8 h after the knockdown coincided with a 2.2-fold increased expression of CYP1B1 (P polymorphism in the promoter region of CAT may determine the amount and activity of catalase, which may subsequently regulate the expression of CYP1B1. As a result, both genetic polymorphisms modulate DNA adduct levels in lymphocytes by BaP ex vivo.

  4. Phytoremediation for co-contaminated soils of chromium and benzo[a]pyrene using Zea mays L.

    Science.gov (United States)

    Chigbo, Chibuike; Batty, Lesley

    2014-02-01

    A greenhouse experiment was carried out to investigate the single effect of benzo[a]pyrene (B[a]P) or chromium (Cr) and the joint effect of Cr-B[a]P on the growth of Zea mays, its uptake and accumulation of Cr, and the dissipation of B[a]P over 60 days. Results showed that single or joint contamination of Cr and B[a]P did not affect the plant growth relative to control treatments. However, the occurrence of B[a]P had an enhancing effect on the accumulation and translocation of Cr. The accumulation of Cr in shoot of plant significantly increased by ≥ 79 % in 50 mg kg(-1) Cr-B[a]P (1, 5, and 10 mg kg(-1)) treatments and by ≥ 86 % in 100 mg kg(-1) Cr-B[a]P (1, 5, and 10 mg kg(-1)) treatments relative to control treatments. The presence of plants did not enhance the dissipation of B[a]P in lower (1and 5 mg kg(-1)) B[a]P contaminated soils; however, over 60 days of planting Z. mays seemed to enhance the dissipation of B[a]P by over 60 % in 10 mg kg(-1) single contaminated soil and by 28 to 41 % in 10 mg kg(-1)B[a]P co-contaminated soil. This suggests that Z. mays might be a useful plant for the remediation of Cr-B[a]P co-contaminated soil.

  5. Analysis of fish bile with HPLC — fluorescence to determine environmental exposure to benzo(a)pyrene

    Science.gov (United States)

    Johnston, Eric P.; Baumann, Paul C.

    1989-01-01

    Brown bullhead from the Black River, Ohio, have a high incidence of liver neoplasia which is associated with elevated concentrations of polynuclear aromatic hydrocarbons (PAHs) in the sediment. We evaluated the use of biliary concentrations of benzo(a)pyrene [B(a)P] equivalents as a means for determining PAH exposure. Bile was collected from 16 brown bullheads and 8 common carp taken from each of two Lake Erie tributaries in Ohio, the industrialized Black River and the non-industrialized Old Woman Creek. Hatchery bullhead (n = 8) were used to determine base levels of PAHs. A high performance liquid chromatography (HPLC) — fluorescence technique was used to determine the concentration of B(a)P equivalents in the bile samples. The area of all peaks fluorescing at 380/430 nm was summed to give a single value for B(a)P equivalents in each sample. Concentrations of B(a)P equivalents generally reflected concentrations of PAH in sediment where fish were collected. Bile taken from Black River carp contained the highest concentration of B(a)P equivalents and was significantly different from all other groups. The value obtained for Black River bullhead was also high and was found to be significantly different from hatchery bullhead. B(a)P equivalents varied between carp and bullhead from the same habitat possibly because of differing food habits or metabolic pathways. However, our results indicate that relative levels of B(a)P equivalents in the bile of fish correspond well to B(a)P levels in sediment and may offer a means of determining environmental exposure of fish to the parent compound.

  6. Toxicogenomic outcomes predictive of forestomach carcinogenesis following exposure to benzo(a)pyrene: relevance to human cancer risk.

    Science.gov (United States)

    Labib, Sarah; Guo, Charles H; Williams, Andrew; Yauk, Carole L; White, Paul A; Halappanavar, Sabina

    2013-12-01

    Forestomach tumors are observed in mice exposed to environmental carcinogens. However, the relevance of this data to humans is controversial because humans lack a forestomach. We hypothesize that an understanding of early molecular changes after exposure to a carcinogen in the forestomach will provide mode-of-action information to evaluate the applicability of forestomach cancers to human cancer risk assessment. In the present study we exposed mice to benzo(a)pyrene (BaP), an environmental carcinogen commonly associated with tumors of the rodent forestomach. Toxicogenomic tools were used to profile gene expression response in the forestomach. Adult Muta™Mouse males were orally exposed to 25, 50, and 75 mgBaP/kg-body-weight/day for 28 consecutive days. The forestomach was collected three days post-exposure. DNA microarrays, real-time RT-qPCR arrays, and protein analyses were employed to characterize responses in the forestomach. Microarray results showed altered expression of 414 genes across all treatment groups (± 1.5 fold; false discovery rate adjusted P ≤ 0.05). Significant downregulation of genes associated with phase II xenobiotic metabolism and increased expression of genes implicated in antigen processing and presentation, immune response, chemotaxis, and keratinocyte differentiation were observed in treated groups in a dose-dependent manner. A systematic comparison of the differentially expressed genes in the forestomach from the present study to differentially expressed genes identified in human diseases including human gastrointestinal tract cancers using the NextBio Human Disease Atlas showed significant commonalities between the two models. Our results provide molecular evidence supporting the use of the mouse forestomach model to evaluate chemically-induced gastrointestinal carcinogenesis in humans.

  7. Effects of ageing and soil properties on the oral bioavailability of benzo[a]pyrene using a swine model.

    Science.gov (United States)

    Duan, Luchun; Palanisami, Thavamani; Liu, Yanju; Dong, Zhaomin; Mallavarapu, Megharaj; Kuchel, Tim; Semple, Kirk T; Naidu, Ravi

    2014-09-01

    Oral bioavailability of benzo[a]pyrene (B[a]P) was studied in a swine model using eight spiked soil samples after incubation for 50 and/or 90 days. Silica sand was used as a reference material and the relative bioavailability (RB) of B[a]P in soils was calculated as the quotient of the area under the plasma B[a]P curve (AUC) for soil and AUC for the silica sand. Significantly reduced RB was observed in all study soils after 90 days ageing, ranging from 22.1±0.4% to 62.7±10.1%, except for one very sandy soil (sand content 87.6%) where RB was unchanged (108.1±8.0%). Apart from this, bioavailability decreased during ageing with the decrease (from day 50 to day 90) being only significant for a clayey soil containing expandable clay minerals. Statistical analyses of B[a]P RB at day 90 (eight soils) and soil properties showed no direct correlation between RB and specific soil properties such as total organic carbon (TOC) and clay content which were commonly linked to organic contaminant sequestration. However, strongly significant relationships (pFPAC) defined as (Silt+Clay)/TOC, and between RB and the soil mesopore (<6nm; p<0.001) fraction, after two samples with high pH and high EC being excluded from the analyses. The bioaccessibility estimated by four in vitro extraction methods: dichloromethane/acetone sonication (DCM/Ace), butanol vortex (BuOH), hydroxypropyl-β-cyclodextrin extraction (HPCD) and Milli Q water leaching methods at different sampling time (1 day, 50 days and 90 days after spiking) also showed a decreasing trend. Significant correlations were found between B[a]P RB and DCM/Ace (R(2)=0.67, p<0.05) extractable fraction and BuOH (R(2)=0.75, p<0.01) extractable fraction.

  8. Sustained systemic delivery of green tea polyphenols by polymeric implants significantly diminishes benzo[a]pyrene-induced DNA adducts.

    Science.gov (United States)

    Cao, Pengxiao; Vadhanam, Manicka V; Spencer, Wendy A; Cai, Jian; Gupta, Ramesh C

    2011-06-20

    The polyphenolics in green tea are believed to be the bioactive components. However, poor bioavailability following ingestion limits their efficacy in vivo. In this study, polyphenon E (poly E), a standardized green tea extract, was administered by sustained-release polycaprolactone implants (two, 2-cm implants; 20% drug load) grafted subcutaneously or via drinking water (0.8% w/v) to female S/D rats. Animals were treated with continuous low dose of benzo[a]pyrene (BP) via subcutaneous polymeric implants (2 cm; 10% load) and euthanized after 1 and 4 weeks. Analysis of lung DNA by (32)P-postlabeling resulted in a statistically significant reduction (50%; p = 0.023) of BP-induced DNA adducts in the implant group; however, only a modest (34%) but statistically insignificant reduction occurred in the drinking water group at 1 week. The implant delivery system also showed significant reduction (35%; p = 0.044) of the known BP diolepoxide-derived DNA adduct after 4 weeks. Notably, the total dose of poly E administered was >100-fold lower in the implant group than the drinking water group (15.7 versus 1,632 mg, respectively). Analysis of selected phase I, phase II, and nucleotide excision repair enzymes at both mRNA and protein levels showed no significant modulation by poly E, suggesting that the reduction in the BP-induced DNA adducts occurred presumably due to known scavenging of the antidiolepoxide of BP by the poly E catechins. In conclusion, our study demonstrated that sustained systemic delivery of poly E significantly reduced BP-induced DNA adducts in spite of its poor bioavailability following oral administration.

  9. Biomarker responses in persian sturgeon (Acipenser persicus exposed to benzo-a-pyrene and beta-naphthoflavone

    Directory of Open Access Journals (Sweden)

    Karimzadeh Katayoon

    2013-01-01

    Full Text Available Biotransformation enzymes of xenobiotics (ethoxyresorufin-O-deethylase, cytochrome P4501A1 content and glutathione-S-transferase were investigated in the liver of Persian Sturgeon (Acipenser persicus after a 96-hour exposure to polycyclic aromatic hydrocarbons (PAHs, premutagenic benzo[a]pyrene (BaP and beta-naphthoflavone (BNF. The fish were injected 10 mg/kg wet-body weight in corn oil for 96 hours every days. Ethoxyresorufin-O-deethylase activity (EROD and glutathione s-transferase activity (GST were measured in the fish liver. Cytochrome P4501A1 (CYP1A1 content was estimated by indirect enzyme-linked immunosorbent assay (ELISA. The response appeared as early as 12 hours post exposure. A time-dependent response was observed in the EROD activity, being significantly higher at 48 hours post exposure to 10 mg/kg of BaP. The greatest induction occurred in the fish treated with 10 mg/kg BaP, in which a 32.1- fold increase in EROD activity was observed. Results showed that EROD activity in A. persicus is significantly increased by BaP and BNF treatments. Both chemicals showed higher values of EROD activity compared to the liver CYP1A content. There was a rise in glutathione-S-transferase activity in fish exposed to BNF, but no increase was observed in fish treated with BaP. The results showed that hepatic CYP1A expression in terms of induction of EROD activity might be suited as a biomarker of organic contamination in aquatic environments and led to lower sensitivity of the second phase in the detoxification enzyme.

  10. Enhanced solubilization of pyrene by saponin, a plant-derived biosurfactant%皂角苷对芘的增溶作用及影响因素

    Institute of Scientific and Technical Information of China (English)

    杨娟娟; 楼林洁; 周文军

    2011-01-01

    Biosurfactants have great advantages in the remediation of organic contaminated soils because of their environmentally friendly nature. The solubilization of pyrene by saponin, a plant-derived biosurfactant, was studied and the results indicated that saponin can greatly enhance the solubilization of pyrene in solution and the weight solubilization ratio (MSR) of saponin to pyrene was greater than those of some representative nonionic surfactants.The enhanced solubilization of pyrene by saponin showed strong dependence on the solution pH and ionic strength. It decreased as the solution pH increased from 4.0 to 8. 0, but increased as the NaCl concentration increased from 0. 01 mol· L- 1 to 1.0 mol · L - 1, which can be attributed to the increased or decreased critical micelle concentration (CMC) of saponin solution with the changing pH or ionic strength, respectively. Saponin was more effective in enhancing pyrene solubilization at low pH and high ionic strength. In addition, heavy metal ions ( Zn2 + and Cd2 + ) can also enhance the solubilization of pyrene by saponin.%研究了一种从植物中提取的生物表面活性剂--皂角苷(saponin)对芘的增溶作用,以及pH、离子强度、重金属离子等对增溶作用的影响.结果表明,皂角苷对芘有明显的增溶作用,其质量溶解率(WSR)约为0.0467,大于常用的Triton X、Brij、Tween等类型的非离子表面活性剂,说明皂角苷能更有效地增强芘的溶解.皂角苷分子中存在可电离的酸性基团,溶液的pH、离子强度等对皂角苷的临界胶束浓度(CMC)及其增溶作用有明显的影响.随着溶液pH值的增大(4.0~8.0),芘在皂角苷溶液中的表观溶解度及WSR值逐渐降低,说明高pH减弱了皂角苷对芘的增溶作用;但随溶液离子强度的增大(NaCl浓度0.01~1.00 mol·L-1),芘在皂角苷溶液中的表观溶解度及WSR值逐渐增大,说明高离子强度增强了皂角苷对芘的增溶作用.因此,在低pH和高离子强度

  11. Effect of Organic Solvents and Biologically Relevant Ions on the Light-Induced DNA Cleavage by Pyrene and Its Amino and Hydroxy Derivatives

    Directory of Open Access Journals (Sweden)

    Hongtao Yu

    2002-09-01

    Full Text Available Abstract: Polycyclic aromatic hydrocarbons (PAHs are a class of carcinogenic compounds that are both naturally and artificially produced. Many PAHs are pro-carcinogens that require metabolic activation. Recently, it has been shown that PAH can induce DNA single strand cleavage and formation of PAH-DNA covalent adduct upon irradiation with UVA light. The light-induced DNA cleavage parallels phototoxicity in one instance. The DNA photocleavage efficiency depends on the structure of the PAHs. This article reports the effect of both organic solvents and the presence of biologically relevant ions, Na+, Mg2+, Ca2+, K+, Fe3+, Cu2+, Zn+2, Mn2+, and I-, on the light-induced DNA cleavage by pyrene, 1-hydroxypyrene and 1-aminopyrene. Since both 1-hydroxypyrene (0.6 μM and 1-aminopyrene (6 μM dissolve well in the minimum organic solvents used (2% methanol, dimethylsulfoxide, and dimethylformamide, increasing the amount of the organic solvent resulted in the decrease of the amount of DNA single strand cleavage caused by the combination effect of 1-hydroxy or 1-aminopyrene and UVA light. The result with the less watersoluble pyrene shows that increase of the amount of the organic solvent can increase the amount of DNA single strand DNA photocleavage cause by the combination of pyrene and UVA light. Therefore, there are two effects by the organic solvents: (i to dissolve PAH and (ii to quench DNA photocleavage. The presence of Fe3+ and Zn2+ enhances, while the presence of Ca2+ and Mn2+ inhibits the DNA photocleavage caused by 1-aminopyrene and UVA light. Other metal ions have minimal effect. This means that the effect of ions on DNA photocleavage by PAHs is complex. The presence of KI enhances DNA photocleavage. This indicates that the triplet-excited state of 1-aminopyrene is involved in causing DNA cleavage

  12. A pyrene-benzthiazolium conjugate portraying aggregation induced emission, a ratiometric detection and live cell visualization of HSO{sub 3}{sup −}

    Energy Technology Data Exchange (ETDEWEB)

    Diwan, Uzra; Kumar, Virendra [Department of Chemistry (Centre of Advanced Study), Faculty of Science, Banaras Hindu University, Varanasi, Uttar Pradesh 221005 (India); Mishra, Rakesh K. [Photosciences and Photonics, Chemical Sciences and Technology Division, CSIR–National Institute for Interdisciplinary Science and Technology, Thiruvananthapuram 695019 (India); Rana, Nishant Kumar; Koch, Biplob; Singh, Manish Kumar [Department of Zoology (Centre of Advanced Study), Faculty of Science, Banaras Hindu University, Varanasi 221005 (India); Upadhyay, K.K., E-mail: drkaushalbhu@yahoo.co.in [Department of Chemistry (Centre of Advanced Study), Faculty of Science, Banaras Hindu University, Varanasi, Uttar Pradesh 221005 (India)

    2016-07-27

    The present study deals with the photophysical property of a pyrene-benzthiazolium conjugate R1, as a strong intramolecular charge transfer (ICT) probe exhibiting long wavelength emission in the red region. Unlike traditional planar polyaromatic hydrocarbons whose aggregation generally quenches the light emission, the pyrene based R1 was found to display aggregation-induced emission (AIE) property along with simultaneous increase in its quantum yield upon increasing the water content of the medium. The R1 exhibits high specificity towards HSO{sub 3}{sup −}/SO{sub 3}{sup 2−} by interrupting its own ICT producing there upon a large ratiometric blue shift of ∼220 nm in its emission spectrum. The lowest detection limit for the above measurement was found to be 8.90 × 10{sup −8} M. The fluorescent detection of HSO{sub 3}{sup −} was also demonstrated excellently by test paper strip and silica coated TLC plate incorporating R1. The live cell imaging of HSO{sub 3}{sup −} through R1 in HeLa cells was studied using fluorescence microscopic studies. The particle size and morphological features of R1 and R1-HSO{sub 3}{sup −} aggregates in aqueous solution were characterized by DLS along with SEM analysis.- Highlights: • A pyrene-benzthiazolium conjugate probe (R1) itself showed interesting phenomenon of an aggregation-induced emission (AIE). • R1 emits in the red channel and effectively utilized as a colorimetric and ratiometric fluorescent sensor for HSO{sub 3}{sup −}. • The nano-dimensional spherical particles of R1 got enlarged upon its interaction with the HSO{sub 3}{sup −}. • R1 can efficiently stain HSO{sub 3}{sup −} in live cells and can be used for the on-spot detection of the same.

  13. Chemical bonding in metal sandwich molecules M nR 2 with R = pyrene C 16H 10 and tetracene C 18H 12

    Science.gov (United States)

    Philpott, Michael R.; Kawazoe, Yoshiyuki

    2007-08-01

    The structures and properties of neutral molecular complexes of palladium transition metal atoms sandwiched between pyrene C 16H 10 and tetracene C 18H 12 molecules have been studied using plane wave based density functional theory. Changes in symmetry and variations in the number of metal atom ( n = 4, 8 for pyrene and n = 4-9 for tetracene) were considered. The metal atoms prefer edge sites with low coordination to ring carbon atoms over "interior" sites with the high coordination as found in bis(benzene) palladium. This appears as a general motif for small polyacene molecules. All compounds examined had stable singlet ( S = 0) ground states relative to separate hydrocarbon and metal cluster, and a lowest triplet state ( S = 1) with spin on the metal atoms. When restricted to D2 h symmetry the sandwich Pd 4(C 16H 10) 2 with pyrene had palladium atoms that were isolated from each other in η 2- and η 3-coordinated sites. The valence electron density was provided mainly by overlap of metal d xy- and d yz-functions with carbon p y ( y-axis ⊥ sandwich plane). The total charge density isometric surfaces showed that η 3-coordination involved higher charge density than η 2-coordination, and that both were weaker than C-C bond charge by an order of magnitude. In the pyrene n = 8 complex, weak metal-metal bonding was apparent around the molecular perimeter together with some metal bonding to the lone interior Pd atom. In sandwiches with tetracene the metal atoms had η 2- and η 3-coordination with ring edge carbon atoms. There were no metal atoms on interior sites. The n = 5 compound with a lopsided Pd distribution had a bonding pattern consistent with experimental work of Murahashi et al. [T. Murahashi, M. Fujimoto, M. Oka, Y. Hashimoto, T. Uemura, Y. Tatsumi, Y. Nakao, A. Ikeda, S. Sakaki, H. Kurosawa, Science 313 (2006) 1104]. Based on geometry (separation ⩽275 pm), total charge density and partial charge density components, we found evidence for metal

  14. Metabolism of benzo(a)pyrene, N-nitrosomethylamine, and N-nitrosopyrrolidine and identification of the major carcinogen-DNA adducts formed in cultured human esophagus

    DEFF Research Database (Denmark)

    1979-01-01

    The wide variation in the world-wide incidence of esophageal carcinoma suggests that environmental agents including chemicals cause this cancer. Since the interaction between chemical procarcinogens and human esophagus has not been studied previously, we examined the metabolic fate of benzo......(a)pyrene (BP), N-nitrosodimethylamine (DMN), and A/-nitrosopyrrolidine in cultured nontumorous esophagus from two patients with and six patients without esophageal carcinoma. Esophageal explants were cultured in a chemically defined medium for 7 days prior to adding [3H]BP (1.5 JUM),[14C]DMN (100 /IM), or [14C...

  15. 'Remote' adiabatic photoinduced deprotonation and aggregate formation of amphiphilic N-alkyl-N-methyl-3-(pyren-1-yl)propan-1-ammonium chloride salts.

    Science.gov (United States)

    Abraham, Shibu; Weiss, Richard G

    2011-11-30

    The absorption and emission properties of a series of amphiphilic N-alkyl-N-methyl-3-(pyren-1-yl)propan-1-ammonium chloride salts were investigated in solvents of different polarities and over a wide concentration range. For example, at 10(-5) M concentrations in tetrahydrofuran (THF), salts with at least one N-H bond exhibited broad, structureless emissions even though time-correlated single photon counting (TCSPC) experiments indicated negligible static or dynamic intermolecular interactions. Salts with a butylene spacer or lacking an N-H bond showed no discernible structureless emission; their emission spectra were dominated by the normal monomeric fluorescence of a pyrenyl group and the TCSPC histograms could be interpreted on the basis of intramolecular photophysics. The broad, structureless emission is attributed to an unprecedented, rapid, adiabatic proton-transfer to the medium, followed by the formation of an intramolecular exciplex consisting of amine and pyrenyl groups. The proposed mechanism involves excitation of a ground-state conformer of the salts in which the ammonium group sits over the pyrenyl ring due to electrostatic stabilization. At higher concentrations, with longer N-alkyl groups, or in selected solvents, electronic excitation of the salts led to dynamic and static excimeric emissions. For example, whereas the emission spectrum of 10(-3) M N-hexyl-N-methyl-3-(pyren-1-yl)propan-1-ammonium chloride in THF consisted of comparable amounts of monomeric and excimeric emission, the emission from 10(-5) M N-dodecyl-N-methyl-3-(pyren-1-yl)propan-1-ammonium chloride in 1:9 (v:v) ethanol/water solutions was dominated by excimeric emission, and discrete particles near micrometer size were discernible from confocal microscopy and dynamic light scattering experiments. Comparison of the static and dynamic emission characteristics of the particles and of the neat solid of N-dodecyl-N-methyl-3-(pyren-1-yl)propan-1-ammonium chloride indicate that molecular

  16. Research Progress in 3-Hydroxybenzo[a]pyrene-biomarker of Benzo[a]pyrene%苯并[a]芘生物标志物3-羟基苯并[a]芘研究进展

    Institute of Scientific and Technical Information of China (English)

    侯宏卫; 张小涛; 熊巍; 唐纲岭; 胡清源

    2012-01-01

    Benzo[a]pyrene (B[a]P) is a main loxic chemical component with tobacco smoking, which is a carcinogen to humans according to the adequate evidence from animals. 3-hydroxybenzo[alpyrene (3-0HB[a]P) is a biomarker of B[a]P exposure. 3-0HB[a]P could be used to distinguish the populations with different levels of exposure, such as smokers, nonsmokers, occupational exposure population, and general population, and to determine the differences in metabolism. The research progress in 3-OHB[a]P is reviewed. Firstly, the carcinogenicity of B[a]P is discussed. And then the source of 3-OHB[a]P as well as the determination method of 3-OHB|a]P are reviewed. The applications of 3-0HB[a]P in biological monitoring are elaborated in detail, including occupational exposure population, smoking population, and the general population. Starting from the exist problems and current research status on 3-OHB[a]P, the prospects for applying 3-OHB[a]P to the study of biological monitoring smokers and general population are analyzed.%苯并[a]芘(B[a]P)是卷烟烟气中的重要有害成分,其在人体内产生的代谢物3-羟基苯并[a]芘(3-OHB[a]P),可作为B[a]P接触生物标志物用于区分不同暴露剂量人群(如吸烟者和非吸烟者,职业暴露和普通人群)及预测可能的作用机制.本文对B[a]P的危害性、3-OHB[a]P来源及检测方法进行了综述;并从3-OHB[a]P研究存在的问题和现状出发,对其在感受烟气和普通人群中进行生物监测的应用进行了展望.

  17. Isolation and identification of a pyrene-degrading bacterial strain in seawater and its pyrene biodegradation features%1株分离自海水中芘降解菌的鉴定及其降解特性研究

    Institute of Scientific and Technical Information of China (English)

    王静; 邱金泉; 张雨山; 杨波; 张晓青; 苗英霞; 张爱君; 张辉

    2011-01-01

    以芘为唯一碳源,对采自于天津港石油污染区的海水和土壤样品进行富集培养,分离到1株芘降解菌,经显微形态观察、生理生化鉴定、16S rRNA基因序列的比对及系统发育进化的分析,确定该菌株为施氏假单孢菌Pseudomonas stutzeri,并采用室内培养方法,对其进行了芘降解性能的测定及降解途径的分析.结果表明,该菌株在以芘为唯一碳源的无机盐培养基中培养36 h后,对芘的降解率达到96%以上.该菌株具有邻二酚2,3-双加氧酶活力,且酶活力随芘质量浓度的增高而提高,可以确定该菌株是以邻苯二酚为中间代谢物对芘进行降解的.%Polycyclic aromatic hydrocarbons (PAHs) are common organic pollutants widely distributed in the natural environment. Their easiness to accumulate and be delivered by food chain and their carcinogenic and mutagenic features make them extremely harmful to human health and ecological environment. A large amount of wastewater containing PAHs flows into the ocean at last, which makes the study of PAHs pollution control of the sea a critical issue. But, due to the particularity and complexity of the marine environment, many regular physical and chemical approaches do not work. In recent years, remediation of the polluted environment with microbial degradation is considered to be the most efficient way to control PAHs contamination. Thus the study on PAHs microbial degradation has become one of the most active areas in marine environmental pollution research, and acquisition of high efficient PAHs-degradating bacteria is the key for biodegradation and bioremediation of PAHs.A pyrene-degrading bacterial strain B5 was separated through selectively enriched culture from the oilcontaminated sample from the Tianjin port. Its characteristics of growth and pyrene degradation ability are studied. This strain B5 grew very fast in culture solution with pyrene as the sole carbon source. The growth entered into logarithm

  18. PCB153, TCDD and estradiol compromise the benzo[a]pyrene-induced p53-response via FoxO3a.

    Science.gov (United States)

    Al-Anati, Lauy; Kadekar, Sandeep; Högberg, Johan; Stenius, Ulla

    2014-08-05

    TCDD, polychlorinated biphenyls (PCB) and polycyclic aromatic hydrocarbons (PAH) coexist in the environment. However, there are few studies on combined effects of these compounds. We have studied the effect of TCDD, PCB153 and estradiol on p53 signaling induced by PAHs. We show that all three compounds amplified the accumulation of nuclear p53, elicited by benzo[a]pyrene (BaP) or dibenzo[al]pyrene (DBP). This effect was associated with an attenuated PAH-induced apoptosis and with decreased levels of phosphorylated FoxO3a Thr32. Thr32 phosphorylation of FoxO3a may promote a translocation of FoxO3a-p53 complex from nucleus to the cytoplasm, and the role of FoxO3a dephosphorylation was further studied. We found that inhibition of PP2A phosphatase restored levels of phosphorylated FoxO3a, led to cytosolic translocation of p53, and activated BaP-induced p53-mediated apoptosis. These results were confirmed by silencing FoxO3a with siRNA or by inhibiting 14-3-3 protein; also these treatments trapped BaP-induced p53 in the nucleus. Our data indicate interplay between p53, FoxO3a and 14-3-3 leading to an attenuated BaP induced apoptosis in cells co-exposed to TCDD, PCB 153 or estradiol.

  19. Analysis of Benzo[a]pyrene in Vegetable Oils Using Molecularly Imprinted Solid Phase Extraction (MISPE Coupled with Enzyme-Linked Immunosorbent Assay (ELISA

    Directory of Open Access Journals (Sweden)

    Michael Pschenitza

    2014-05-01

    Full Text Available This paper describes the development of a molecularly imprinted polymer-based solid phase extraction (MISPE method coupled with enzyme-linked immunosorbent assay (ELISA for determination of the PAH benzo[a]pyrene (B[a]P in vegetable oils. Different molecularly imprinted polymers (MIPs were prepared using non-covalent 4-vinylpyridine/divinylbenzene co-polymerization at different ratios and dichloromethane as porogen. Imprinting was done with a template mixture of phenanthrene and pyrene yielding a broad-specific polymer for PAHs with a maximum binding capacity (Q of ~32 μg B[a]P per 50 mg of polymer. The vegetable oil/n-hexane mixture (1:1, (v/v was pre-extracted with acetonitrile, the solvent evaporated, the residue reconstituted in n-hexane and subjected to MISPE. The successive washing with n-hexane and isopropanol revealed most suitable to remove lipid matrix constituents. After elution of bound PAHs from MISPE column with dichloromethane, the solvent was evaporated, the residue reconstituted with dimethyl sulfoxide and diluted 100-fold with methanol/water (10:90, (v/v for analysis of B[a]P equivalents with an ELISA. The B[a]P recovery rates in spiked vegetable oil samples of different fatty acid composition were determined between 63% and 114%. The presence of multiple PAHs in the oil sample, because of MIP selectivity and cross-reactivity of the ELISA, could yield overestimated B[a]P values.

  20. Alterations to proteome and tissue recovery responses in fish liver caused by a short-term combination treatment with cadmium and benzo[a]pyrene

    Energy Technology Data Exchange (ETDEWEB)

    Costa, P.M., E-mail: pmcosta@fct.unl.p [IMAR-Instituto do Mar, Departamento de Ciencias e Engenharia do Ambiente, Faculdade de Ciencias e Tecnologia da Universidade Nova de Lisboa, 2829-516 Monte de Caparica (Portugal); Chicano-Galvez, E.; Lopez Barea, J. [Departamento de Bioquimica y Biologia Molecular, Universidad de Cordoba, Campus de Rabanales, Edificio Severo Ochoa, 14071 Cordoba (Spain); DelValls, T.A. [UNESCO/UNITWIN/WiCop Chair-Departamento de Quimica Fisica, Facultad de Ciencias del Mar y Ambientales, Universidad de Cadiz, Poligono rio San Pedro s/n, 11510 Puerto Real, Cadiz (Spain); Costa, M.H. [IMAR-Instituto do Mar, Departamento de Ciencias e Engenharia do Ambiente, Faculdade de Ciencias e Tecnologia da Universidade Nova de Lisboa, 2829-516 Monte de Caparica (Portugal)

    2010-10-15

    The livers of soles (Solea senegalensis) injected with subacute doses of cadmium (Cd), benzo[a]pyrene (B[a]P), or their combination, were screened for alterations to cytosolic protein expression patterns, complemented by cytological and histological analyses. Cadmium and B[a]P, but not combined, induced hepatocyte apoptosis and Kupfer cell hyperplasia. Proteomics, however, suggested that apoptosis was triggered through distinct pathways. Cadmium and B[a]P caused upregulation of different anti-oxidative enzymes (peroxiredoxin and glutathione peroxidase, respectively) although co-exposure impaired induction. Similarly, apoptosis was inhibited by co-exposure, to which may have contributed a synergistic upregulation of tissue metalloproteinase inhibitor, {beta}-actin and a lipid transport protein. The regulation factors of nine out of eleven identified proteins of different types revealed antagonistic or synergistic effects between Cd and B[a]P at the prospected doses after 24 h of exposure. The results indicate that co-exposure to Cd and B[a]P may enhance toxicity by impairing specific responses and not through cumulative damage. - The interaction between cadmium and benzo[a]pyrene impairs specific responses to toxicity and tissue repair mechanisms.

  1. Binding of benzo(a)pyrene to DNA by cytochrome P-450 catalyzed one-electron oxidation in rat liver microsomes and nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Cavalieri, E.L.; Rogan, E.G.; Devanesan, P.D.; Cremonesi, P. (Univ. of Nebraska Medical Center, Omaha (USA)); Cerny, R.L.; Gross, M.L. (Univ. of Nebraska, Lincoln (USA)); Bodell, W.J. (Univ. of California, San Francisco (USA))

    1990-05-22

    To investigate whether cytochrome P-450 catalyzes the covalent binding of substrates to DNA by one-electron oxidation, the ability of both uninduced and 3-methylcholanthrene (MC) induced rat liver microsomes and nuclei to catalyze covalent binding of benzo(a)pyrene (BP) to DNA and formation of the labile adduct 7-(benzo(a)pyren-6-yl)guanine (BP-N7Gua) was investigated. In the various systems studied, 1-9 times more BP-N7Gua adduct was isolated than the total amount of stable BP adducts in the DNA. The specific cytochrome P-450 inhibitor 2-((4,6-dichloro-o-biphenyl)oxy)ethylamine hydrobromide (DPEA) reduced or eliminated BP metabolism, binding of BP to DNA, and formation of BP-N7Gua by cytochrome P-450 in both microsomes and nuclei. The effects of the antioxidants cysteine, glutathione, and p-methoxythiophenol were also investigated. This study represents the first demonstration of cytochrome P-450 mediating covalent binding of substrates to DNA via one-electron oxidation and suggests that this enzyme can catalyze peroxidase-type electron-transfer reactions.

  2. Effects of benzo[a]pyrene dietary intake to antioxidative enzymes of Lymantria dispar (Lepidoptera: Lymantriidae) larvae from unpolluted and polluted forests.

    Science.gov (United States)

    Gavrilović, Anja; Ilijin, Larisa; Mrdaković, Marija; Vlahović, Milena; Mrkonja, Aleksandra; Matić, Dragana; Perić-Mataruga, Vesna

    2017-07-01

    Anthropogenic activity in industrial development has imposed great threats to the environment and wildlife in the form of persistent organic pollutants. Polycyclic aromatic hydrocarbons (PAH) tend to accumulate in vegetation foliage which is the main food source of polyphagous insect species Lymantria dispar L. Origin and multigenerational adaptation of L. dispar population to environmental challenges strongly condition the enzymes' sensitivity to pollutants. In this study, our aim was to investigate response of the superoxide dismutase (SOD), catalase (CAT) and glutathione S-transferase (GST) to the chronic dietary exposure of benzo[a]pyrene in the midgut tissues and hemolymph of two L. dispar populations originating from unpolluted and polluted forest habitat. Midgut tissue of the larvae from the polluted forest showed significant increase in SOD, CAT and GST activity, while in unpolluted forest's larvae SOD and CAT showed elevated activities in hemolymph. L. dispar populations adapted to different level of pollution in their environment and expressed distinct tissue-dependent antioxidative enzyme sensitivity to benzo[a]pyrene diet, implying high potential for further elucidation of these enzymes as molecular biomarkers. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. DNA polymerase eta participates in the mutagenic bypass of adducts induced by benzo[a]pyrene diol epoxide in mammalian cells.

    Directory of Open Access Journals (Sweden)

    Alden C Klarer

    Full Text Available Y-family DNA-polymerases have larger active sites that can accommodate bulky DNA adducts allowing them to bypass these lesions during replication. One member, polymerase eta (pol eta, is specialized for the bypass of UV-induced thymidine-thymidine dimers, correctly inserting two adenines. Loss of pol eta function is the molecular basis for xeroderma pigmentosum (XP variant where the accumulation of mutations results in a dramatic increase in UV-induced skin cancers. Less is known about the role of pol eta in the bypass of other DNA adducts. A commonly encountered DNA adduct is that caused by benzo[a]pyrene diol epoxide (BPDE, the ultimate carcinogenic metabolite of the environmental chemical benzo[a]pyrene. Here, treatment of pol eta-deficient fibroblasts from humans and mice with BPDE resulted in a significant decrease in Hprt gene mutations. These studies in mammalian cells support a number of in vitro reports that purified pol eta has error-prone activity on plasmids with site-directed BPDE adducts. Sequencing the Hprt gene from this work shows that the majority of mutations are G>T transversions. These data suggest that pol eta has error-prone activity when bypassing BPDE-adducts. Understanding the basis of environmental carcinogen-derived mutations may enable prevention strategies to reduce such mutations with the intent to reduce the number of environmentally relevant cancers.

  4. Modulation of adult rat benzo(a)pyrene (BaP) metabolism and DNA adduct formation by neonatal diethylstilbestrol (DES) exposure.

    Science.gov (United States)

    Ramesh, Aramandla; Inyang, Frank; Knuckles, Maurice E

    2004-12-01

    This study seeks to elucidate the role of diethylstilbestrol (DES), a synthetic estrogen on benzo(a)pyrene (BaP) metabolism in the male rat reproductive tissues. Offspring of timed-pregnant Sprague-Dawley rats were neonatally treated on days 2, 4, and 6 post-partum with 1.45 micromol/kg of DES. Ten weeks after birth, the adult rats were challenged with radiolabeled benzo(a)pyrene (3H BaP) (10 micromol/kg) and the rats were sacrificed 2 h after BaP exposure. Prostrate, testis, lung, liver, urine and feces samples were collected and extracted using a mixture of H2O, MeOH and CHCl3. The extracts were analyzed by reverse phase HPLC. The concentrations of BaP organic metabolites in DES rats were lower compared to controls (vehicle-treated rats). On the other hand, concentrations of aqueous metabolites were significantly increased in DES treated animals. The toxication to detoxication ratios were significantly decreased in DES rats compared to controls. This trend is also reflected in the decreased concentrations of BaP-DNA adducts in DES rats. Collectively these results suggest that DES is capable of modulating the metabolic pathway of BaP towards detoxification thereby preventing the manifestation of toxicity.

  5. Steady-State Fluorescence and Lifetime Emission Study of pH-Sensitive Probes Based on i-motif Forming Oligonucleotides Single and Double Labeled with Pyrene

    Directory of Open Access Journals (Sweden)

    Anna Dembska

    2015-09-01

    Full Text Available Cytosine-rich nucleic acids undergo pH-stimulated structural transitions leading to formation of an i-motif architecture at an acidic pH. Thus, i-motifs are good foundation for designing simple pH-sensitive fluorescent probes. We report here steady-state and time-resolved fluorescence studies of pyrene-labeled probes based on RET sequence: C4GC4GC4GC4TA (RET21, AC4GC4GC4GC4TA (RET21A and C4GC4GC4GC4T (RET20. Comparative studies with single- and double-labeled i-motif probes were carried out. For each probe, we have measured fluorescence spectra and decays for emission wavelength of 390 nm over a wide range of pH (from 4.0 to 8.0. Effect of the oligonucleotide sequence and the number of pyrene labels on the spectral characteristics of probes were discussed.

  6. Inhibitory effects of the phorbolester TPA and cigarette smoke condensate on the mutagenicity of benzo(a)pyrene in a co-cultivation system

    Energy Technology Data Exchange (ETDEWEB)

    Jongen, W.M.; Hakkert, B.C.; van de Poll, M.L.

    1986-01-01

    The transport of reactive intermediates was studied in a co-cultivation system of primary chick embryo hepatocytes and V79 Chinese hamster cells. Two test systems with different genetic endpoints--sister-chromatid exchange (SCE) and gene mutation at the hypoxanthine-guanine phosphoribosyl transferase (HGPRT) locus--were used. Benzo(a)pyrene (B(a)P) was positive in both test systems. When the V79 cells were co-cultivated with the hepatocytes at a distance of 1 mm, only a slight increase in the number of SCEs was observed after exposure to benzo(a)pyrene. When the two cell types were in direct contact, addition of the phorbolester TPA or cigarette smoke condensate inhibited the mutagenic effects of B(a)P in both assays by 50%. No influence of TPA on the number of SCEs induced by B(a)P was observed in a preincubation assay using Aroclor-1254-induced rat liver homogenate. The results indicate that metabolic co-operation may play a role in the transport of reactive intermediates in this co-cultivation system. The mutagenic potential of compounds may be underestimated in systems using intact cells for metabolic activation if the compounds or their metabolites are capable of inhibiting metabolic co-operation.

  7. Impact of benzo(a)pyrene, Cu and their mixture on the proteomic response of Mytilus galloprovincialis

    Energy Technology Data Exchange (ETDEWEB)

    Maria, V.L., E-mail: vmaria@ualg.pt [CIMA, Faculty of Sciences and Technology, University of Algarve, Campus de Gambelas, 8005-139 Faro (Portugal); Gomes, T., E-mail: tcgomes@ualg.pt [CIMA, Faculty of Sciences and Technology, University of Algarve, Campus de Gambelas, 8005-139 Faro (Portugal); Barreira, L., E-mail: lbarreir@ualg.pt [CCMAR, Faculty of Sciences and Technology, University of Algarve, Campus de Gambelas, 8005-139 Faro (Portugal); Bebianno, M.J., E-mail: mbebian@ualg.pt [CIMA, Faculty of Sciences and Technology, University of Algarve, Campus de Gambelas, 8005-139 Faro (Portugal)

    2013-11-15

    Highlights: •Distinct protein expression profiles dependent of BaP and Cu accumulation, metabolism and chemical interactions in mussels, Mytilus galloprovincialis. •Processes that involve adhesion and motility, cytoskeleton and cell structure, stress response, transcription regulation and energy metabolism are common mechanisms. •Traditional (ATP synthase, GST, HSP and actin) and novel biomarkers for BaP (ZFP), Cu (chitin synthase) and mixture (MVP) exposures identified in mussels. -- Abstract: In natural waters, chemical interactions between mixtures of contaminants can result in potential synergistic and/or antagonic effects in aquatic animals. Benzo(a)pyrene (BaP) and copper (Cu) are two widespread environmental contaminants with known toxicity towards mussels Mytilus spp. The effects of the individual and the interaction of BaP and Cu exposures were assessed in mussels Mytilus galloprovincialis using proteomic analysis. Mussels were exposed to BaP [10 μg L{sup −1} (0.396 μM)], and Cu [10 μg L{sup −1} (0.16 μM)], as well as to their binary mixture (mixture) for a period of 7 days. Proteomic analysis showed different protein expression profiles associated to each selected contaminant condition. A non-additive combined effect was observed in mixture in terms of new and suppressed proteins. Proteins more drastically altered (new, suppressed and 2-fold differentially expressed) were excised and analyzed by mass spectrometry, and eighteen putatively identified. Protein identification demonstrated the different accumulation, metabolism and chemical interactions of BaP, Cu and their mixture, resulting in different modes of action. Proteins associated with adhesion and motility (catchin, twitchin and twitchin-like protein), cytoskeleton and cell structure (α-tubulin and actin), stress response (heat shock cognate 71, heat shock protein 70, putative C1q domain containing protein), transcription regulation (zinc-finger BED domain-containing and nuclear

  8. Antioxidant responses to benzo[a]pyrene,tributyltin and their mixture in the spleen of Sebasticus marmoratus

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    It has been repotted that there is an interaction between Benzo[a]pyrene (BaP),a widespread carcinogenic polycyclic aromatic hydrocarbon,and tributyltin (TBT),an organometal used as an antifouling biocide.This study was therefore designed to examine the potential in vivo influence of BaP,TBT and their mixture on splenic antioxidant defense systems of Sebastiscus marmoratus.The fish were exposed to water containing euvironmentally relevant concentrations of BaP,TBT and their mixture.Spleens were collected for biochemical analysis after exposure for 7,25,50 d and after recovery for 7,20 d.Cotreatment with BaP and TBT for 7 d potentiated the induction of glutathione pemxidase (GPx) activity by BaP or TBT alone.The cotreatment for 25 and 50 d resulted in inhibition of GPx activity,which was similar to the effect of TBT.Splenic glutathione S-transferase (GST) activities were significantly elevated in S.marmoratus exposed to BaP starting from 7d and remained high up to 25 d.However,no further activity change was found with prolonged exposure.Cotreatment of BaP and TBT primarily inhibited the GST activity,which was similar to the effect of TBT.Cotreatment with BaP and TBT for 25 or 50 d potentiated the depletion of GSH (glutathione) by BaP or TBT alone.MDA (malondialdehyde) contents in spleen of S.marmoratus were not significantly altered compared with the control during the test period.Spleen,as an immune organ,is sensitive to exposure of BaP or TBT.It should have an effective mechanism to counteract oxidative damage.Antioxidative defense systems in spleen of S.marmoratus should be considered as potential biomarkers.Short-term exposure of BaP or TBT could result in induction of antioxidant defense system.A significant decrease of these indices.such as GSH,GST,GPx might indicate more severe contamination.

  9. Benzo(a)pyrene induces hepatic AKR1A1 mRNA expression in tilapia fish (Oreochromis niloticus).

    Science.gov (United States)

    Osorio-Yáñez, Citlalli; García-Tavera, José Luis; Pérez-Núñez, Maria Teresa; Poblete-Naredo, Irais; Muñoz, Balam; Barron-Vivanco, Briscia S; Rothenberg, Stephen J; Zapata-Pérez, Omar; Albores, Arnulfo

    2012-07-01

    AKR1A1 or aldehyde reductase is a member of the aldo-keto reductases superfamily that is evolutionarily conserved among species. AKR1A1 is one of the five AKRs (AKR1A1 and 1C1-1C4) implicated in the metabolic benzo(a)pyrene (BaP) activation to reactive BaP 7,8-dione. BaP is a polycyclic aromatic hydrocarbon (PAH) widely distributed in aquatic ecosystems and its metabolic activation is necessary to produce its toxic effects. Although the presence of AKR1A1 in fish has been reported, its tissue distribution in tilapia (Oreochromis niloticus) and AKR1A1 inducibility by BaP are not known yet. Moreover, cytochrome P4501A (CYP1A) mRNA expression in fish has been used as a PAH biomarker of effect. Therefore, BaP effects on AKR1A1 and CYP1A gene expressions in tilapia, a species of commercial interest, were investigated by real-time RT-PCR. A partial AKR1A1 cDNA was identified, sequenced and compared with AKR1A1 reported sequences in the GenBank DNA database. Constitutive AKR1A1 mRNA expression was detected mainly in liver, similarly to that of CYP1A. BaP exposure resulted in statistically significant AKR1A1 and CYP1A mRNA induction in liver (20- and 120-fold, respectively) at 24 h. On the other hand, ethoxyquin (EQ) was used as control inducer for AKR1A1 mRNA. Interestingly, EQ also induced CYP1A mRNA levels in tilapia liver. Our results suggest that teleost AKR1A1, in addition to CYP1A, are inducible by BaP. The mechanism of AKR1A1 induction by BaP and its role in fish susceptibility to BaP toxic effects remains to be elucidated.

  10. Effects of the co-carcinogen catechol on benzo(a)pyrene metabolism and DNA adduct formation in mouse skin

    Energy Technology Data Exchange (ETDEWEB)

    Melikian, A.A.; Leszczynska, J.M.; Hecht, S.S.; Hoffmann, D.

    1986-01-01

    We have studied the effects of the co-carcinogen catechol (1,2-dihydroxybenzene) on the metabolic activation of (/sup 3/H) benzo(a)pyrene (BaP) in mouse skin, in vivo and on the binding of BaP metabolites to DNA and protein at intervals from 0.5-24 h. Upon topical application of 0.015 mg (/sup 3/H)BaP and 0.25 or 0.5 mg catechol per mouse, catechol had little effect on the total amount of (/sup 3/H)BaP metabolized in mouse skin, but it affected the relative proportions of (/sup 3/H)BaP metabolites. Catechol (0.5 mg/mouse) decreased the proportion of water-soluble (/sup 3/H)BaP metabolites, ethyl acetate-soluble polar metabolites and quinones, but doubled the levels of unconjugated 3-hydroxy-BaP at all measured intervals after treatment. Catechol also caused a small increase in the levels of trans-7,8-dihydroxy-7,8-dihydroBaP and trans-9,10-dihydroxy-9,10-dihydroBaP 0.5 h after treatment. Two hours after treatment, the levels of these metabolites subsided to those of the controls. Catechol did not affect the levels of glutathione conjugates of BaP. However, it caused a decrease in glucuronide and sulphate conjugate formation from BaP. Catechol caused an approximately 2-fold increase in the formation of anti-7,8-dihydroxy-9,10-epoxy-7,8,9,10-tetrahydroBaP (BPDE) DNA adducts and elevated the ratio of anti-syn-BPDE-DNA adducts 1.6 to 2.9-fold. Catechol treatment increased the radioactivity associated with epidermal proteins after (/sup 3/H)BaP application. Because catechol increased levels of 3-hydroxyBaP, we considered the possibility that 3-hydroxyBaP might enhance the tumor initiating activities of BaP or BPDE in mouse skin; a bioassay demonstrated that this was not the case. The results of this study indicate that one important effect of catechol related to its co-carcinogenicity is its ability to enhance formation of anti-BPDE-DNA adducts in mouse skin.

  11. Novel interstrand communication systems within DNA duplexes based on 1-, 2- and 4-(phenylethynyl)pyrenes attached to 2′-amino-LNA: high-affinity hybridization and fluorescence sensing

    DEFF Research Database (Denmark)

    Astakhova, Irina; Lindegaard, Dorthe; Korshun, Vladimir A.

    2010-01-01

    Functionalisation of 2′-amino-LNA oligonucleotides with 1-, 2- and 4-(phenylethynyl)pyrene fluorophores via a carbonyl linker (PEPyc) resulted in efficient interstrand communication systems in nucleic acid duplexes, providing effective tools for stabilization of nanostructures and fluorescence...

  12. THE EFFECT OF PENTACHLOROPHENOL ON DNA ADDUCT FORMATION IN C57B1/6 TRP53 +/+ AND C57B16 TRP53 -/- MICE EXPOSED TO BENZO[A]PYRENE MAY BE ASSOCIATED WITH P53 FUNCTION.

    Science.gov (United States)

    AbstractPrevious studies have shown that pentachlorophenol (PCP) has both potentiative and antagonistic effects on the genotoxicity of benzo[a]pyrene (B[a]P). It has been suggested that these effects are due to inhibition and/or induction of enzymes involved in the biotr...

  13. Laser Photolysis Studies on Pyrene in Ionic Liquids and Conventional Solvents%芘在离子液体及常规溶剂中的激光闪光光解研究

    Institute of Scientific and Technical Information of China (English)

    付海英; 邢兆国; 吴国忠

    2011-01-01

    利用纳秒级时间分辨激光光解装置,以Nd:YAG激光器三倍频后的355 nm激光作为激发光源,研究了芘在常规溶剂乙腈、丙酮、环己烷、1-丁基-3-甲基咪唑六氟磷酸离子液体([Bmim][PF6])、N-丁基吡啶四氟硼酸离子液体([BuPy][BF4])以及三乙基庚基铵双三氟甲磺酰亚胺(R4NNTf2)的瞬态光解行为,比较了芘在各类体系中的瞬态光谱及反应动力学行为.研究表明芘在离子液体中各类瞬态物种的寿命均较常规溶剂延长,且反应速率常数随着离子液体的类型的变化而不同.与[Bmim][PF6]和R4NNTf2相比,[BuPy][BF4]最为活泼,认为主要是由于[BuPy][BF4]自身参加了反应.%The photochemistry of pyrene in conventional solvents (acetone, acetonitrile, cyclohexane) and ionic liquids [Bmim][PF6 ], [BuPy][BF4 ], R4 NNTf2 was investigated by time-resolved laser photolytic techniques. The transient absorption spectra of the excited pyrene and other radical species were compared. The absorption hand of pyrene cation radical was observed in the acetone, acetronitrile and pyridiniurn ionic liquid [BuPy][BF4 ] systems. Only excited triplet pyrene was observed in cyclohexane and [Bmim][PF6 ] and R4 NNTf2. The result demonstrates that there was an interaction between pyrene and solvents, and the pyrene cation radical was formed by electron transfer from the excited state of pyrene to acetonitrile, acetone and [BuPy][BF4 ].The possible mechanisms of the six systerna were suggested.

  14. Agarose-chitosan-C18 film micro-solid phase extraction combined with high performance liquid chromatography for the determination of phenanthrene and pyrene in chrysanthemum tea samples.

    Science.gov (United States)

    Ng, Nyuk Ting; Sanagi, Mohd Marsin; Wan Ibrahim, Wan Nazihah; Wan Ibrahim, Wan Aini

    2017-05-01

    Agarose-chitosan-immobilized octadecylsilyl-silica (C18) film micro-solid phase extraction (μSPE) was developed and applied for the determination of phenanthrene (PHE) and pyrene (PYR) in chrysanthemum tea samples using high performance liquid chromatography-ultraviolet detection (HPLC-UV). The film of blended agarose and chitosan allows good dispersion of C18, prevents the leaching of C18 during application and enhances the film mechanical stability. Important μSPE parameters were optimized including amount of sorbent loading, extraction time, desorption solvent and desorption time. The matrix match calibration curves showed good linearity (r⩾0.994) over a concentration range of 1-500ppb. Under the optimized conditions, the proposed method showed good limits of detection (0.549-0.673ppb), good analyte recoveries (100.8-105.99%) and good reproducibilities (RSDs⩽13.53%, n=3) with preconcentration factors of 4 and 72 for PHE and PYR, respectively.

  15. Antimutagenic activity of some naturally occurring compounds towards cigarette-smoke condensate and benzo(a)pyrene in the Salmonella/microsome assay

    Energy Technology Data Exchange (ETDEWEB)

    Terwel, L.; van der Hoeven, J.C.

    1985-10-01

    Several compounds, occurring in food, were tested for antimutagenic activity towards cigarette-smoke condensate (CSC) and benzo(a)pyrene (BaP). Antimutagenicity was determined in the Salmonella/microsome test, with tester strain TA98, in the presence of rat-liver homogenate. Dose-response curves did show reduction of CSC- and BaP-induced mutagenicity by ellagic acid, riboflavin and chlorophyllin. Chlorophyll a and chlorophyll b, although less distinct, also inhibited CSC- and BaP-induced mutagenicity. Ascorbic acid, beta-carotene, tocopherol acetate, chlorogenic acid and butyl hydroxyanisole did not have any influence on the mutagenicity of CSC and BaP. The similarity in results for cigarette-smoke condensate and for BaP indicates that a general mechanism may be involved in the inhibition of CSC- and BaP-induced mutagenicity.

  16. Use of high pressure liquid chromatography to study chemically induced alterations in the pattern of benzo(a)pyrene metabolism. [Rat liver microsomes

    Energy Technology Data Exchange (ETDEWEB)

    Freudenthal, R.I.; Leber, A.P.; Emmerling, D.; Clarke, P.

    1975-11-01

    The metabolism of radiolabeled benzo(a)pyrene (BP) by control, 3-methylcholanthrene (3-MC) induced and 1,1,1-trichloropropene-2,3-oxide (TCPO)-inhibited rat liver microsomes was measured using fluorescence, radiometric, and high-pressure liquid chromatographic (HPLC) assays. Significant differences in the total measurable metabolism of BP by the three microsomal enzyme incubations resulted from the use of the three assay procedures. Appreciable differences in the concentration of the metabolite fractions after 3-MC induction and TCPO inhibition are clearly demonstrated. NMR analysis revealed that while the 3-hydroxy-BP fraction is greater than 90 percent pure, the 9-hydroxy fraction contains a number of metabolites having essentially identical retention times.

  17. ([2.2.2]Cryptand-κ(6)O)potassium (η(4)-cyclo-octa-diene)bis-(η(2)-pyrene)cobaltate(1-) pentane hemisolvate.

    Science.gov (United States)

    Brennessel, William W; Ellis, John E

    2012-07-01

    The cation, anion, and solvent in the title compound, [K(C(18)H(36)N(2)O(6))][Co(C(8)H(12))(C(16)H(10))(2)]·0.5C(5)H(12), are well separated. The pentane solvent mol-ecules are found in channels along [100] and were modeled as disordered over crystallographic inversion centers. Using the mid-points of the coordinated olefins, the angle between the C(py)/C(py)-Co-C(py)/C(py) and the C(cod)/C(cod)-Co-C(cod)/C(cod) planes (py is pyrene and cod is cyclo-octa-diene) is 67.6 (2)°. Thus, the overall geometry of the coordination sphere around cobalt is best described as distorted tetra-hedral.

  18. Metabolism of benzo(a)pyrene and 7,12-dimethylbenz(a)anthracene in cultured human bronchus and pancreatic duct

    DEFF Research Database (Denmark)

    1977-01-01

    The metabolism of two carcinogenic polynuclear aro matic hydrocarbons, benzo[a]pyrene (BP) and 7,12-dimethylbenz[a]anthracene, was studied in expiants of human pancreatic duct and bronchus cultured in a chemically defined medium. In cultured human bronchial mucosa, activity of aryl hydrocarbon...... hydroxylase was inducible by both benz[a]anthracene and BP. Prior exposure of the bronchial expiants to benz[a]anthracene altered the qualitative features of the metabolite profile of BP as analyzed by highpressure liquid chromatography. The metabolite profiles of BP produced by normal-appearing bronchi from...... cochromatographed with both the 9,10-diol and a triol of BP. 7,12-Dimethylbenz[a]anthracene was bound to the DMA of cultured human bronchial cells at higher levels than was BP. Binding of 7,12-dimethylbenz[a]anthracene to DMA in human pancreatic duct was consistently less than that in cultured bronchi in the 5...

  19. Determination of benzo[a]pyrene levels in ambient air and the source of polycyclic aromatic hydrocarbons using a diagnostic ratio method in Ghana.

    Science.gov (United States)

    Bortey-Sam, Nesta; Akoto, Osei; Ikenaka, Yoshinori; Nakayama, Shouta M M; Ishizuka, Mayumi

    2013-02-01

    Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous contaminants produced from incomplete combustion of fuel or vegetation fires. Their presence in air deserves attention because they can produce carcinogenic and mutagenic effects. As an industrialized and economically significant city in Ghana, Kumasi has been subject to heavy anthropogenic influences due to rapid economic development and urbanization leading to a greater fuel combustion rate. Airborne particulate samples were collected on filters using a Sibata air sampler and analyzed by gas chromatography-mass spectrometry (GC-MS). Our results indicated that air from the city center can be classified as highly polluted with benzo[a] pyrene (B[a]P). The diagnostic ratios of the results showed that PAHs in the air samples were mainly from fuel combustion.

  20. Hydroponic growth of crops in presence of /sup 14/C-benzo(a)pyrene. [/sup 14/C tracer study in beans, cantaloupes, and cotton plants

    Energy Technology Data Exchange (ETDEWEB)

    Blum, S.C.; Swarbrick, R.E.

    1975-09-01

    An attempt was made to evaluate the fate of a polynuclear aromatic hydrocarbon in the food chain under severe and exaggerated experimental conditions. Green beans, cantaloupes, and cotton were grown hydroponically in nutrient-containing aqueous solutions saturated with carbon-14 labeled benzo(a)pyrene, a known carcinogen. The plants were selected because of different growing times involved: 6, 12, and 22 weeks for green beans, cantaloupes, and cotton, respectively, as well as the great differences in these plant types. Results indicate that the translocation or migration of polynuclear aromatic hydrocarbons during the growth cycle of crops is not a reasonable expectation. Any such contamination found in crops would, therefore, require some other explanation.

  1. Binding of 1-nitro(/sup 14/C)pyrene to DNA and protein in cultured lung macrophages and respiratory tissues

    Energy Technology Data Exchange (ETDEWEB)

    King, L.C.; Ball, L.M.; Lewtas, J. (Envrironmental Protection Agency, Research Triangle Park, Genetic Toxicology Division); Jackson, M. (Environmental Protection Agency, Research Triangle Park, Cellular Pathology and Biochemistry Section)

    1983-07-01

    Binding of 1-nitro(/sup 14/C)pyrene(1-NP) or its metabolites to cellular DNA and protein in cultures of rabbit alveolar macrophages and lung and tracheal tissues was examined. DNA binding was highest in tracheal tissue (136.9 +- 18.3 pmol 1-NP/mg DNA). DNA binding in macrophages and lung tissue was one-fifth of the level observed in tracheal tissue. Also, 1-NP was bound to cellular protein in tracheal and lung tissues, and at a lower level in macrophages. Co-cultivation of the macrophages with lung and tracheal tissues decreased the DNA binding in tracheal tissue and increased the protein binding in macrophages. This study shows that lung cells and tissue are capable of binding 1-NP or its metabolites to DNA and protein.

  2. Influence of dietary fat type on benzo(a)pyrene [B(a)P] biotransformation in a B(a)P-induced mouse model of colon cancer.

    Science.gov (United States)

    Diggs, Deacqunita L; Myers, Jeremy N; Banks, Leah D; Niaz, Mohammad S; Hood, Darryl B; Roberts, L Jackson; Ramesh, Aramandla

    2013-12-01

    In the US alone, around 60,000 lives/year are lost due to colon cancer. Diet and environment have been implicated in the development of sporadic colon tumors. The objective of this study was to determine how dietary fat potentiates the development of colon tumors through altered B(a)P biotransformation, using the Adenomatous polyposis coli with Multiple intestinal neoplasia mouse model. Benzo(a)pyrene was administered to mice through tricaprylin, and unsaturated (USF; peanut oil) and saturated (SF; coconut oil) fats at doses of 50 and 100 μg/kg via oral gavage over a 60-day period. Blood, colon, and liver were collected at the end of exposure period. The expression of B(a)P biotransformation enzymes [cytochrome P450 (CYP)1A1, CYP1B1 and glutathione-S-transferase] in liver and colon were assayed at the level of protein, mRNA and activities. Plasma and tissue samples were analyzed by reverse phase high-performance liquid chromatography for B(a)P metabolites. Additionally, DNA isolated from colon and liver tissues was analyzed for B(a)P-induced DNA adducts by the (32)P-postlabeling method using a thin-layer chromatography system. Benzo(a)pyrene exposure through dietary fat altered its metabolic fate in a dose-dependent manner, with 100 μg/kg dose group registering an elevated expression of B(a)P biotransformation enzymes, and greater concentration of B(a)P metabolites, compared to the 50 μg/kg dose group (Pcolon and liver, whose concentrations also registered a dose-dependent increase. These metabolites were found to bind with DNA and form B(a)P-DNA adducts, which may have contributed to colon tumors in a subchronic exposure regimen.

  3. Benchmark theoretical study of the ionization energies, electron affinities and singlet-triplet energy gaps of azulene, phenanthrene, pyrene, chrysene and perylene

    Energy Technology Data Exchange (ETDEWEB)

    Huzak, M. [Theoretical Chemistry and Molecular Modelling, Hasselt University, Agoralaan, Gebouw D, B-3590 Diepenbeek (Belgium); Hajgato, B. [General Chemistry Division, Free University of Brussels (VUB), Pleinlaan 2, B-1050 Brussels (Belgium); Deleuze, M.S., E-mail: michael.deleuze@uhasselt.be [Theoretical Chemistry and Molecular Modelling, Hasselt University, Agoralaan, Gebouw D, B-3590 Diepenbeek (Belgium)

    2012-10-08

    Highlights: Black-Right-Pointing-Pointer Electronic properties of aromatic hydrocarbons are computed at benchmark levels. Black-Right-Pointing-Pointer Electron correlation has a very strong influence on the computed results. Black-Right-Pointing-Pointer The role of structural relaxation and zero-point vibrations is highlighted. Black-Right-Pointing-Pointer We approach chemical accuracy, using the principles of a focal point analysis. -- Abstract: The vertical and adiabatic singlet-triplet energy gaps, electron affinities and ionization energies of azulene, phenanthrene, pyrene, chrysene, and perylene are computed by applying the principles of a focal point analysis onto a series of single-point calculations at the level of Hartree-Fock theory, second-, third-, and fourth-order Moller-Plesset perturbation theory, as well as coupled cluster theory including single, double and perturbative triple excitations, in conjunction with correlation consistent basis sets of improving quality. Results are supplemented with an extrapolation to the limit of an asymptotically complete basis set. According to our best estimates, azulene, phenanthrene, pyrene, chrysene, and perylene exhibit adiabatic singlet-triplet energy gaps of 1.79, 2.92, 2.22, 2.79 and 1.71 eV, respectively. In the same order, the corresponding adiabatic electron affinities (EAs) amount to 0.71, -0.08, -0.40, 0.24, and 0.87 eV, whereas benchmark values equal to 7.43, 8.01, 7.48, 7.66 and 7.15 eV, are found for the adiabatic ionization energies.

  4. A new series of short axially symmetrically and asymmetrically 1,3,6,8-tetrasubstituted pyrenes with two types of substituents: Syntheses, structures, photophysical properties and electroluminescence

    Science.gov (United States)

    Zhang, Ran; Zhang, Tengfei; Xu, Lu; Han, Fangfang; Zhao, Yun; Ni, Zhonghai

    2017-01-01

    A new series of short axially symmetrically (4a and 4b) and asymmetrically (4c and 4d) 1,3,6,8-tetrasubstituted pyrene-based compounds with two phenyl moieties and two diphenylamine units on the pyrene core were designed and synthesized based on stepwise synthetic strategy. These compounds were structurally characterized and their photoelectric properties were investigated by spectroscopy, electrochemical and theoretical studies. The structures of 4a and 4b were determined by single-crystal X-ray diffraction analysis, indicating that the compounds are twisted by the peripheral substituents and the intermolecular π-π interactions have been efficiently interrupted. The four compounds exhibit high absolute fluorescence quantum yields (VF) in dichloromethane (83.31-88.45%) and moderate VFs in film states (20.78-38.68%). In addition, compounds 4a and 4b display relatively higher absolute VFs than those of 4c and 4d in film states. All the compounds exhibit high thermal stability with decomposition temperatures above 358 °C and the values of 4c and 4d are higher than 4a and 4b. Compounds 4a and 4b can form morphologically stable amorphous thin films with Tg values of 146 °C and 149 °C, respectively. However, there are no obvious Tg observed in compounds 4c and 4d. Electroluminescent devices using 4a and 4b as doped emission layer show promising device performance with low turn-on voltage (3.0 V), maximum brightness around 15100 cd/m2 and 16100 cd/m2, maximum luminance efficiency of 12.4 cd/A and 13.6 cd/A and maximum external quantum efficiency of 5.34% and 5.63%, respectively.

  5. In vitro metabolism of benzo[a]pyrene-7,8-dihydrodiol and dibenzo[def,p]chrysene-11,12 diol in rodent and human hepatic microsomes

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Jordan N.; Mehinagic, Denis; Nag, Subhasree; Crowell, Susan R.; Corley, Richard A.

    2017-03-01

    Polycyclic aromatic hydrocarbons (PAHs) are contaminants that are ubiquitously found in the environment, produced through combustion of organic matter or petrochemicals, and many of which are procarcinogens. The prototypic PAH, benzo[a]pyrene (B[a]P) and the highly carcinogenic dibenzo[def,p]chrysene (DBC) are metabolically activated by isoforms of the P450 enzyme superfamily producing benzo[a]pyrene-7,8-dihydrodiol (B[a]P diol), dibenzo[def,p]chrysene-11,12 diol (DBC diol). Each of these diols can be further metabolized by cytochrome P450 enzymes to highly reactive diol-epoxide metabolites that readily react with DNA or by phase II conjugation facilitating excretion. To complement prior in vitro metabolism studies with parent B[a]P and DBC, both phase I metabolism and phase II glucuronidation of B[a]P diol and DBC diol were measured in hepatic microsomes from female B6129SF1/J mice, male Sprague-Dawley rats, and female humans. Metabolic parameters, including intrinsic clearance and Michaelis-Menten kinetics were calculated from substrate depletion data. Mice and rats demonstrated similar B[a]P diol phase I metabolic rates. Compared to rodents, human phase I metabolism of B[a]P diol demonstrated lower overall metabolic capacity, lower intrinsic clearance at higher substrate concentrations (>0.14 µM), and higher intrinsic clearance at lower substrate concentrations (<0.07 µM). Rates of DBC diol metabolism did not saturate in mice or humans and were highest overall in mice. Higher affinity constants and lower capacities were observed for DBC diol glucuronidation compared to B[a]P diol glucuronidation; however, intrinsic clearance values for these compounds were consistent within each species. Kinetic parameters reported here will be used to extend physiologically based pharmacokinetic (PBPK) models to include the disposition of B[a]P and DBC metabolites in animal models and humans to support future human health risk assessments.

  6. The Japanese medaka (Oryzias latipes) model: applicability for investigating the immunosuppressive effects of the aquatic pollutant benzo[a]pyrene (BaP).

    Science.gov (United States)

    Carlson, E A; Li, Y; Zelikoff, J T

    2002-01-01

    Despite the fact that BaP is a carcinogen, mammalian immunosuppressant, and ubiquitous aquatic pollutant, knowledge regarding the effects of BaP on the immune system of fish is still lacking. To begin to fill this gap, studies were conducted in medaka to examine the effects and mechanisms by which BaP exposure might alter host immunocompetence. Fish, exposed by IP injection of BaP (2-600 microg/g BW), were examined after 48 h for effects upon immune function and CYP1A expression/activity. Benzo[a]pyrene, at a concentration below that which increased levels of CYPIA expression/activity (2 microg BaP/g BW) suppressed lymphocyte proliferation. Concentrations of BaP at 20 and 200 microg/g BW. suppressed antibody-forming cell (AFC) numbers, superoxide production, and host resistance against bacteria. In contrast, exposure to the low affinity aryl hydrocarbon receptor (AhR) agonist, benzo[e]pyrene (BeP), neither induced CYP1A expression nor altered immune function. Given the lack of immunosuppressive effects produced by BeP, and the fact that exposure to the AhR antagonist (and CYP1A inhibitor) alpha-naphthoflavone (ANF) ameliorated the suppressive effects of BaP upon AFC numbers, the AhR pathway (including CYP1A-mediated production of reactive BaP metabolites) appears important in mediating BaP-induced immunotoxicity in fish, as in mammals. In the past, the medaka has proven a successful model for assessing carcinogenic agents. These studies have demonstrated its utility for also determining the immunosuppressive effects of an important aquatic contaminant.

  7. Use of Physiologically-Based Pharmacokinetic Modeling to Simulate the Profiles of 3-Hydroxybenzo(a)pyrene in Workers Exposed to Polycyclic Aromatic Hydrocarbons

    Science.gov (United States)

    Heredia Ortiz, Roberto; Maître, Anne; Barbeau, Damien; Lafontaine, Michel; Bouchard, Michèle

    2014-01-01

    Biomathematical modeling has become an important tool to assess xenobiotic exposure in humans. In the present study, we have used a human physiologically-based pharmacokinetic (PBPK) model and an simple compartmental toxicokinetic model of benzo(a)pyrene (BaP) kinetics and its 3-hydroxybenzo(a)pyrene (3-OHBaP) metabolite to reproduce the time-course of this biomarker of exposure in the urine of industrially exposed workers and in turn predict the most plausible exposure scenarios. The models were constructed from in vivo experimental data in rats and then extrapolated from animals to humans after assessing and adjusting the most sensitive model parameters as well as species specific physiological parameters. Repeated urinary voids from workers exposed to polycyclic aromatic hydrocarbons (PAHs) have been collected over the course of a typical workweek and during subsequent days off work; urinary concentrations of 3-OHBaP were then determined. Based on the information obtained for each worker (BaP air concentration, daily shift hours, tasks, protective equipment), the time courses of 3-OHBaP in the urine of the different workers have been simulated using the PBPK and toxicokinetic models, considering the various possible exposure routes, oral, dermal and inhalation. Both models were equally able to closely reproduce the observed time course of 3-OHBaP in the urine of workers and predicted similar exposure scenarios. Simulations of various scenarios suggest that the workers under study were exposed mainly by the dermal route. Comparison of measured air concentration levels of BaP with simulated values needed to obtain a good approximation of observed time course further pointed out that inhalation was not the main route of exposure for most of the studied workers. Both kinetic models appear as a useful tool to interpret biomonitoring data of PAH exposure on the basis of 3-OHBaP levels. PMID:25032692

  8. In vitro metabolism of benzo[a]pyrene-7,8-dihydrodiol and dibenzo[def,p]chrysene-11,12 diol in rodent and human hepatic microsomes.

    Science.gov (United States)

    Smith, Jordan N; Mehinagic, Denis; Nag, Subhasree; Crowell, Susan R; Corley, Richard A

    2017-01-21

    Polycyclic aromatic hydrocarbons (PAHs) are contaminants that are ubiquitously found in the environment, produced through combustion of organic matter or petrochemicals, and many of which are procarcinogens. The prototypic PAH, benzo[a]pyrene (B[a]P) and the highly carcinogenic dibenzo[def,p]chrysene (DBC) are metabolically activated by isoforms of the P450 enzyme superfamily producing benzo[a]pyrene-7,8-dihydrodiol (B[a]P diol), dibenzo[def,p]chrysene-11,12 diol (DBC diol). Each of these diols can be further metabolized by cytochrome P450 enzymes to highly reactive diol-epoxide metabolites that readily react with DNA or by phase II conjugation facilitating excretion. To complement prior in vitro metabolism studies with parent B[a]P and DBC, both phase I metabolism and phase II glucuronidation of B[a]P diol and DBC diol were measured in hepatic microsomes from female B6129SF1/J mice, male Sprague-Dawley rats, and female humans. Metabolic parameters, including intrinsic clearance and Michaelis-Menten kinetics were calculated from substrate depletion data. Mice and rats demonstrated similar B[a]P diol phase I metabolic rates. Compared to rodents, human phase I metabolism of B[a]P diol demonstrated lower overall metabolic capacity, lower intrinsic clearance at higher substrate concentrations (>0.14μM), and higher intrinsic clearance at lower substrate concentrations (P diol glucuronidation; however, intrinsic clearance values for these compounds were consistent within each species. Kinetic parameters reported here will be used to extend physiologically based pharmacokinetic (PBPK) models to include the disposition of B[a]P and DBC metabolites in animal models and humans to support future human health risk assessments.

  9. Kinetic flow dichroism study of conformational changes in supercoiled DNA induced by ethidium bromide and noncovalent and covalent binding of benz[a]pyrene diol epoxide.

    Science.gov (United States)

    Yoshida, H; Swenberg, C E; Geacintov, N E

    1987-03-10

    The dynamic conformational changes due to the noncovalent intercalative binding of ethidium bromide and racemic trans-7,8-dihydroxy-anti-9,10-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene (BPDE), and the covalent binding of BPDE to supercoiled phi X174 DNA, have been studied by gel electrophoresis and a novel application of a kinetic flow linear dichroism technique. The magnitude of the linear dichroism (delta A) of the DNA oriented in the flow gradient is sensitive to the hydrodynamic shape of the DNA molecule which is affected by the binding of the drug or the carcinogen BPDE. While the linear dichroism of ethidium bromide supercoiled DNA is time independent, the delta A spectra of BPDE-DNA reaction mixtures vary on time scales of minutes, which correspond to the reaction rate constant of BPDE to form 7,8,9,10-tetrahydroxytetrahydrobenzo[a]pyrene hydrolysis products and covalent DNA adducts. The rapid noncovalent intercalation of BPDE causes an initial large increase in delta A (up to 250%, corresponding to the dichroism observed with relaxed circular DNA), followed by a slower decrease in the linear dichroism signal. This decrease in delta A is attributed to the removal of intercalated diol epoxide molecules and the resulting reversible increase in the number of superhelical turns. The kinetic flow dichroism spectra indicate that the noncovalent BPDE-DNA complexes are intercalative in nature, while the covalent adducts are characterized by a very different conformation in which the long axes of the pyrenyl residues are oriented at a large angle with respect to the average orientation of the planes of the DNA bases.(ABSTRACT TRUNCATED AT 250 WORDS)

  10. Advancement in Research of Benzo[a]pyrene Toxicity on Neurodevelopment%B[a]P所致神经发育毒性的研究进展

    Institute of Scientific and Technical Information of China (English)

    段蕾; 聂继盛

    2011-01-01

    B[a]P(benzo[a]pyrene,B[a]P)是重要的职业和环境污染物之一,它的神经发育毒性与致癌性\\致畸性相比虽是一种弱效应,但会对处于发育中的机体造成不良后果,尤其是中枢神经系统对其更为敏感.本课题组以近年来国内外有关B[a]P神经发育毒性的研究为基础,综述其流行病学研究、实验动物研究以及可能的毒性机制等方面研究进展;结合本课题组的已有研究,认为由于B[a]P的神经发育毒性所致学习和记忆损伤应得到广泛关注.%Benzo[a]pyrene (B[a]P) is one of the most important occupational and environmental contaminants. Compared with its carcinogenicity and teratogenicity, its toxicity on neurodevelopment is a weak effect, but could cause serious and adverse consequences for the developing individuals, especially for the central nervous system, which is a very sensitive target. In this paper, based on the research progresses of B[a]P toxicity on neurodevelopment at home and abroad, we summarized the epidemiological studies, neurotoxicity in animal models, and plausible mechanism due to B[a]P exposure. Combined with our previous study, more attention should be paid to the damage to learning and memory by B[a]P exposure.

  11. 一株芘的高效降解菌的选育及其降解性能研究%Breeding of a high-performance pyrene-degrading strain and its biodegradation performance

    Institute of Scientific and Technical Information of China (English)

    唐玉斌; 马姗姗; 王晓朝; 陈芳艳

    2011-01-01

    A preponderant pyrene-degrading strain B-1 was isolated and purified from activated sludge collected from aeration basin of a coking plant to provide microorganism resource and scientific basis for bioremediation of the environment polluted by polycyclic aromatic hydrocarbons. Strain B-1 could grow and breed in liquid mineral salt medium with pyrene as sole carbon source and resist pyrene with concentration up to about 130 mg/L. Strain B-1 was initially identified as Bacillus by the results of morphological observation, physio-biochemical test and 16S rDNA sequence analysis. The incubation amount, initial pyrene concentration of liquid medium, pH and salinity are the factors to affect pyrene degradation efficiency. Under the conditions of incubation amount of 15% (V/V), initial pyrene concentration of 20 ~100 mg/L and temperature of 30℃, strain B-1 could preserve high degradation activities of pyrene in the range of the pH 4 ~ 11 and the salinity less than 1%. With the initial pyrene concentration of 80 mg/L, incubation amount of 13% V/V), pyrene degradation percentage by strain B1 was 92.4% after 10 days.%旨在为多环芳烃污染环境的生物修复提供微生物资源和科学依据,从某焦化厂曝气池的活性污泥中分离纯化出一株降解芘的优势菌株B-1,该菌株可在以芘为惟一碳源的培养基中生长繁殖,能利用芘的最高浓度为130 mg/L左右.经形态学观察、生理生化实验及l6S rDNA序列分析,初步判断菌株B-1为芽胞杆菌属.投菌量、芘初始浓度、pH和盐度是影响芘降解效率的因素.在投菌量为15%(V/V)、芘初始浓度为20~100 mg/L和温度为30℃的条件下,该菌在pH为4~11、盐度在1%以内可保持对芘良好的降解能力.当芘初始浓度为80 mg/L,投菌量为13%(V/V),历时10 d,芘的降解效率可达92.4%.

  12. Direct and Auger Electron-Induced, Single- and Double-Strand Breaks on Plasmid DNA Caused by 99mTc-Labeled Pyrene Derivatives and the Effect of Bonding Distance

    Science.gov (United States)

    Reissig, Falco; Mamat, Constantin; Steinbach, Joerg; Pietzsch, Hans-Juergen; Freudenberg, Robert; Navarro-Retamal, Carlos; Caballero, Julio; Kotzerke, Joerg; Wunderlich, Gerd

    2016-01-01

    It is evident that 99mTc causes radical-mediated DNA damage due to Auger electrons, which were emitted simultaneously with the known γ-emission of 99mTc. We have synthesized a series of new 99mTc-labeled pyrene derivatives with varied distances between the pyrene moiety and the radionuclide. The pyrene motif is a common DNA intercalator and allowed us to test the influence of the radionuclide distance on damages of the DNA helix. In general, pUC 19 plasmid DNA enables the investigation of the unprotected interactions between the radiotracers and DNA that results in single-strand breaks (SSB) or double-strand breaks (DSB). The resulting DNA fragments were separated by gel electrophoresis and quantified by fluorescent staining. Direct DNA damage and radical-induced indirect DNA damage by radiolysis products of water were evaluated in the presence or absence of the radical scavenger DMSO. We demonstrated that Auger electrons directly induced both SSB and DSB in high efficiency when 99mTc was tightly bound to the plasmid DNA and this damage could not be completely prevented by DMSO, a free radical scavenger. For the first time, we were able to minimize this effect by increasing the carbon chain lengths between the pyrene moiety and the 99mTc nuclide. However, a critical distance between the 99mTc atom and the DNA helix could not be determined due to the significantly lowered DSB generation resulting from the interaction which is dependent on the type of the 99mTc binding motif. The effect of variable DNA damage caused by the different chain length between the pyrene residue and the Tc-core as well as the possible conformations of the applied Tc-complexes was supplemented with molecular dynamics (MD) calculations. The effectiveness of the DNA-binding 99mTc-labeled pyrene derivatives was demonstrated by comparison to non-DNA-binding 99mTcO4–, since nearly all DNA damage caused by 99mTcO4– was prevented by incubating with DMSO. PMID:27583677

  13. 溶剂效应对脱除煤沥青中3,4-苯并芘的影响%Solvent effect on removal of benzo[a]pyrene in coal tar pitch

    Institute of Scientific and Technical Information of China (English)

    孙昱; 廖志远; 苏龙; 曾鹏

    2014-01-01

    研究了单种溶剂、混合溶剂对3,4-苯并芘的溶解选择性及煤沥青溶解量。并以顺丁烯二酸酐为改性剂、硫酸为催化剂,考察了溶剂效应对降低煤沥青中3,4-苯并芘的影响。研究表明,环己烷、甲苯,环己烷、乙酸丁酯组成的混合溶剂具有较好的3,4-苯并芘溶解选择性和合适的煤沥青溶解量。当环己烷∶甲苯=2∶1(体积比)和环己烷∶乙酸丁酯=2∶1(体积比)为反应溶剂时,能够高效地脱除煤沥青中3,4-苯并芘,煤沥青中3,4-苯并芘降低率分别达到88.26%和90.83%。其原因认为是此类溶剂能使包裹在沥青颗粒内部的3,4-苯并芘释放出来,且3,4-苯并芘与改性剂能够形成均相反应体系,大部分不具有致癌性的高相对分子质量环芳烃与改性剂之间形成两相体系,从而提高了改性剂与3,4-苯并芘的有效反应。%The solubility selectivity for benzo[a]pyrene and dissolved amount for coal tar pitch of single solvent,mixed solvents were studied. Using maleic anhydride as modifying agent and sulfuric acid as catalyst,the solvent effect on reducing the concentration of benzo[a]pyrene in coal tar pitch was investigated. The mixed solvents,cyclohexane and toluene,cyclohexane and butyl acetate had appropriate benzo[a]pyrene solubility selectivity and coal tar pitch solubility. When using cyclohexane∶toluene=2∶1(v/v),cyclohexane∶butyl acetate=2∶1(v/v)as reaction solvent, benzo[a]pyrene in coal tar pitch could be removed efficiently,with decreases of 88.26%and 90.83%for benzo[a]pyrene in coal tar pitch respectively. Using these kinds of solvent,benzo[a]pyrene wrapped in coal tar pitch could be released. In addition,a homogeneous system between modifying agent and benzo[a]pyrene was formed,with most non-carcinogenic high molecular weight PAHs and modifying agent forming a two phase system. As a result,the effective reaction between modifying agent and benzo[a]pyrene was greatly

  14. Edible Oil of Benzo(α) pyrene Detection Methods of Comparison and Optimization%食用油脂中苯并(α)芘检测方法比较与优化

    Institute of Scientific and Technical Information of China (English)

    宋长虹; 唐生; 佟馨; 郝克非; 尚刚; 邓斌

    2014-01-01

    The edible oils benzo (α) pyrene detected mainly includes sample pretreatment and determination of basic processes, Because benzo (α)pyrene is the minimal content and poor stability in vegetable oil and complexity of the sample matrix such as triglycerides potential interferences esters and fatty accompaniment , etc. So how to detect benzo(α) pyrene in the food quickly and accurately, that becomes the focus of the research stage. As the basis of"animal fat benzo (α) pyrene was measured by RP-HPLC"of the national standard GB/T22509-2008. We make optimizations for several samples preparation method and HPLC conditions and compare the results.%食用油中苯并(α)芘的检测主要包括样品的预处理和测定2个基本过程,由于植物油中苯并(α)芘含量极微,稳定性差,样品基体复杂且存在潜在的多种干扰物,如大量甘油三酯和脂肪伴随物,所以如何快速、准确地检测出食品中的苯并(α)芘,就成为人们现阶段研究的重点。以国家标准GB/T22509-2008《动植物油脂苯并(α)芘的测定反相高效液相色谱法》为基础,对几种样品前处理方法及液相色谱条件进行优化,并对检测结果进行对比。

  15. Cystic squamous cell carcinomas in the lungs of Syrian golden hamsters induced by coal oven flue exhaust mixed with pyrolized tar pitch in combination with benzo(a)pyrene.

    Science.gov (United States)

    Rittinghausen, S; Dungworth, D L; Dasenbrock, C; Ernst, H; Mohr, U

    1997-02-01

    Among a variety of induced pulmonary tumours, cystic squamous cell carcinomas were observed in five Syrian hamsters that inhaled a mixture of pyrolized tar pitch with coal oven flue exhaust (PCE) and additionally received intratracheal injections of benzo(a)pyrene. The histological appearance of these particular tumours is described, compared to similar tumour types in rats and the susceptibility of both species to inert particles is discussed.

  16. Probing the conformation and 2D-distribution of pyrene-terminated redox-labeled poly(ethylene glycol) chains end-adsorbed on HOPG using cyclic voltammetry and atomic force electrochemical microscopy.

    Science.gov (United States)

    Anne, Agnès; Bahri, Mohamed Ali; Chovin, Arnaud; Demaille, Christophe; Taofifenua, Cécilia

    2014-03-14

    The present paper aims at illustrating how end-attachment of water-soluble flexible chains bearing a terminal functional group onto graphene-like surfaces has to be carefully tuned to ensure the proper positioning of the functional moiety with respect to the anchoring surface. The model experimental system considered here consists of a layer of poly(ethylene glycol) (PEG) chains, bearing an adsorbing pyrene foot and a ferrocene (Fc) redox functional head, self-assembled onto highly oriented pyrolytic graphite (HOPG). Cyclic voltammetry is used to accurately measure the chain coverage and gain insights into the microenvironment experienced by the Fc heads. Molecule-touching atomic force electrochemical microscopy (Mt/AFM-SECM) is used to simultaneously probe the chain conformation and the position of the Fc heads within the layer, and also to map the 2D-distribution of the chains over the surface. This multiscale electrochemical approach allows us to show that whereas Fc-PEG-pyrene readily self-assembles to form extremely homogeneous layers, the strongly hydrophobic nature of graphite planes results in a complex coverage-dependent structure of the PEG layer due to the interaction of the ferrocene label with the HOPG surface. It is shown that, even though pyrene is known to adsorb particularly strongly onto HOPG, the more weakly adsorbing terminal ferrocene can also act as the chain anchoring moiety especially at low coverage. However we show that beyond a critical coverage value the Fc-PEG-pyrene chains adopt an ideal "foot-on" end-attached conformation allowing the Fc head to explore a volume away from the surface solely limited by the PEG chain elasticity.

  17. 黑麦草根系抗氧化系统和细胞质膜透性对土壤中芘胁迫的响应%Antioxidative Activities and CMP of Rye Grass Rhizotaxy under Pyrene Stress

    Institute of Scientific and Technical Information of China (English)

    蔡顺香; 颜明娟; 林琼; 邱孝煊; 陈子聪

    2012-01-01

    Effects of varying Pyrene levels in soil on the antioxidative activities and cytoplasm membrane permeability (CMP) in the rhizotaxy of rye grass were studied. The results showed that the effect of the Pyrene stress appeared mostly 20d after treatment. The contents of CMP, MDA and SS in the roots increased significantly under 100-400 mg · kg-1 Pyrene addition in the soil. The membrane lipids of the rye grass roots showed serious peroxidation. On the other hand, the catalase (CAT) activity and non-enzymatic antioxidant GSH content added dramatically to protect the root cells from injuries. The activities of peroxidase (POD) and superoxide dismutase (SOD) reduced under the Pyrene stress, with the POD activity decreased significantly.%采用盆栽试验研究土壤中添加不同浓度芘对黑麦草根系抗氧化系统和细胞质膜透性的影响.结果表明:芘对黑麦草根系抗氧化系统和细胞质膜透性的影响主要表现在试验20 d时,100~400mg·kg-1芘浓度下黑麦草根系的CMP、MDA和SS含量显著增加,膜脂过氧化严重;同时CAT活性和非酶抗氧化剂GSH含量相应显著上升,以保护根细胞免受伤害.另外2种抗氧化酶POD活性和SOD活性则明显下降,其中POD活性下降显著.

  18. Comparison of Analytical Methods for Three Carcinogenic Polycyclic Aromatic Hydrocarbons (PAHs): naphthalene, anthracene, pyrene%致癌性多环芳烃萘、蒽、芘的分析方法比较

    Institute of Scientific and Technical Information of China (English)

    杨发忠; 苏永庆

    2009-01-01

    利用薄层色谱(TLC)、紫外光谱(UV)、反相高效液相色谱(RP-HPLC)对多环芳烃(PAHs)萘、蒽、芘的分析方法进行了研究.TLC中使用环己烷∶氯仿(5∶4,V/V)作为展开剂时,三者的Rf值分别为0.78、0.65和0.72;用UV法在溶液中测定了三者的最大吸收波长分别为303、380、338 nm;当流动相为甲醇∶水(9∶1,V/V)时三者在RP-HPLC中的保留时间为4.179、5.190、6.178 min,5次重复RSD分别为1.1%、1.8%、0.91%,并用于实际水样中萘、蒽、芘的分析.%The analytical methods of TLC, UV, RP-HPLC for analyzing three Polycyclic Aromatic Hydrocarbons (PAHs), i.e. naphthalene, anthracene and pyrene, were studied. The Rf values of naphthalene, anthracene and pyrene, were developing agent in TLC. The maximum absorption wavelengths in UV spectra of naphthalene, anthracene and pyrene were 303, 380, 338 nm, respectively. The retention values of naphthalene, anthracene and pyrene in RP-HPLC were 4.179, real water sample were analyzed.

  19. CYP1A1 and CYP1B1 gene expression and DNA adduct formation in normal human mammary epithelial cells exposed to benzo[a]pyrene in the absence or presence of chlorophyllin.

    Science.gov (United States)

    John, Kaarthik; Divi, Rao L; Keshava, Channa; Orozco, Christine C; Schockley, Marie E; Richardson, Diana L; Poirier, Miriam C; Nath, Joginder; Weston, Ainsley

    2010-06-28

    Benzo[a]pyrene (BP) is a potent pro-carcinogen and ubiquitous environmental pollutant. Here, we examined the induction and modulation of CYP1A1 and CYP1B1 and 10-(deoxyguanosin-N(2)-yl)-7,8,9-trihydroxy-7,8,9,10-tetrahydrobenzo[a]pyrene (BPdG) adduct formation in DNA from 20 primary normal human mammary epithelial cell (NHMEC) strains exposed to BP (4muM) in the absence or presence of chlorophyllin (5muM). Real-time polymerase chain reaction (RT-PCR) analysis revealed strong induction of both CYP1A1 and CYP1B1 by BP, with high levels of inter-individual variability. Variable BPdG formation was found in all strains by r7, t8-dihydroxy-t-9, 10 epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene (BPDE)-DNA chemiluminescence assay (CIA). Chlorophyllin mitigated BP-induced CYP1A1 and CYP1B1 gene expression in all 20 strains when administered with BP. Chlorophyllin, administered prior to BP-exposure, mitigated CYP1A1 expression in 18/20 NHMEC strains (pchlorophyllin followed by administration of the carcinogen with chlorophyllin (pchlorophyllin is likely to be a good chemoprotective agent for a large proportion of the human population.

  20. Enhanced thyroid hormone breakdown in hepatocytes by mutual induction of the constitutive androstane receptor (CAR, NR1I3) and arylhydrocarbon receptor by benzo[a]pyrene and phenobarbital.

    Science.gov (United States)

    Schraplau, Anne; Schewe, Bettina; Neuschäfer-Rube, Frank; Ringel, Sebastian; Neuber, Corinna; Kleuser, Burkhard; Püschel, Gerhard P

    2015-02-03

    Xenobiotics may interfere with the hypothalamic-pituitary-thyroid endocrine axis by inducing enzymes that inactivate thyroid hormones and thereby reduce the metabolic rate. This induction results from an activation of xeno-sensing nuclear receptors. The current study shows that benzo[a]pyrene, a frequent contaminant of processed food and activator of the arylhydrocarbon receptor (AhR) activated the promoter and induced the transcription of the nuclear receptor constitutive androstane receptor (CAR, NR1I3) in rat hepatocytes. Likewise, phenobarbital induced the AhR transcription. This mutual induction of the nuclear receptors enhanced the phenobarbital-dependent induction of the prototypic CAR target gene Cyp2b1 as well as the AhR-dependent induction of UDP-glucuronosyltransferases. In both cases, the induction by the combination of both xenobiotics was more than the sum of the induction by either substance alone. By inducing the AhR, phenobarbital enhanced the benzo[a]pyrene-dependent reduction of thyroid hormone half-life and the benzo[a]pyrene-dependent increase in the rate of thyroid hormone glucuronide formation in hepatocyte cultures. CAR ligands might thus augment the endocrine disrupting potential of AhR activators by an induction of the AhR. Copyright © 2014. Published by Elsevier Ireland Ltd.

  1. Detection of a novel mutagen, 3,6-dinitrobenzo[e]pyrene, as a major contaminant in surface soil in Osaka and Aichi Prefectures, Japan.

    Science.gov (United States)

    Watanabe, Tetsushi; Hasei, Tomohiro; Takahashi, Tomoyuki; Asanoma, Masaharu; Murahashi, Tsuyoshi; Hirayama, Teruhisa; Wakabayashi, Keiji

    2005-02-01

    We previously identified 1,3-, 1,6-, and 1,8-dinitropyrene (DNP) isomers as major mutagens in surface soil in three metropolitan areas of Japan. In the present study, an organic extract from surface soil collected at a park in Takatsuki in Osaka Prefecture, which showed extremely high mutagenicity in Salmonella typhimurium TA98 in the absence of mammalian metabolic system (S9 mix), was investigated to identify major mutagens. A new powerful bacterial mutagen, as well as 1,6- and 1,8-DNP isomers, was isolated from the organic extract (1.8 g) of the soil sample (2.2 kg) by column chromatography. On the basis of mass spectra, the new mutagen, which accounted for 15% of the total mutagenicity of the soil extract, was thought to be a dinitrated polycyclic aromatic hydrocarbon with a molecular weight of m/z 342. The mutagen was synthesized from benzo[e]pyrene by nitration and was determined to be 3,6-dinitrobenzo[e]pyrene (DNBeP) based on its 1H NMR spectrum. The mutagenic potency of 3,6-DNBeP in the Ames/Salmonella assay was extremely high, in that it induced 285,000 revertants/nmol in TA98 and 955,000 revertants/nmol in YG1024 without S9 mix and was comparable to those of DNP isomers, which are some the most potent bacterial mutagens reported so far. In addition to the soil sample from Takatsuki, 3,6-DNBeP was also detected in surface soil samples collected at parks in four different cities, i.e., Izumiotsu and Takaishi in Osaka Prefecture and Nagoya and Hekinan in Aichi Prefecture, and accounted for 22-29% of the total mutagenicity of these soil extracts in TA98 without S9 mix. These results suggest that 3,6-DNBeP is a major mutagen in surface soil and may largely contaminate the surface soil in these two regions in Japan.

  2. Probing the micellization kinetics of pyrene end-labeled diblock copolymer via a combination of stopped-flow light-scattering and fluorescence techniques.

    Science.gov (United States)

    Zhang, Jingyan; Li, Yuting; Armes, Steven P; Liu, Shiyong

    2007-10-25

    A pyrene end-labeled double hydrophilic diblock copolymer, poly(2-(diethylamino)ethyl methacrylate)-b-poly(2-(dimethylamino)ethyl methacrylate) (Py-PDEA-b-PDMA), was synthesized by sequential monomer addition via oxyanionic polymerization using a 1-pyrenemethanol-based initiator. This diblock copolymer exhibits reversible pH-responsive micellization behavior in aqueous solution, forming PDEA-core micelles stabilized by the soluble PDMA block at neutral or alkaline pH. Taking advantage of the pyrene probe covalently attached to the end of the PDEA block, the pH-induced micellization kinetics of Py-PDEA-b-PDMA was monitored by stopped-flow light scattering using a fluorescence detector. Upon a pH jump from 4.0 to 9.0, both the scattered light intensity and excimer/monomer fluorescence intensity ratios (IE/IM) increase abruptly initially, followed by a more gradual increase to reach plateau values. Interestingly, the IE/IM ratio increases abruptly within the first 10 ms: a triple exponential function is needed to fit the corresponding dynamic trace, leading to three characteristic relaxation time constants (tau(1,fluo) fluo) fluo)). On the other hand, dynamic traces for the scattered light intensity can be well-fitted by double exponential functions: the resulting time constants tau(1,scat) and tau(2,scat) can be ascribed to formation of the quasi-equilibrium micelles and relaxation into their final equilibrium state, respectively. Most importantly, tau(1,scat) obtained from stopped-flow light scattering is in general agreement with tau(2,fluo) obtained from stopped-flow fluorescence. The fastest process (tau(1,fluo) approximately 4 ms) detected by stopped-flow fluorescence is ascribed to the burst formation of small transient micelles comprising only a few chains, which are too small to be detected by conventional light scattering. These nascent micelles undergo rapid fusion and grow into quasi-equilibrium micelles and then slowly approach their final equilibrium

  3. Novel poly(triphenylamine-alt-fluorene) with asymmetric hexaphenylbenzene and pyrene moieties: synthesis, fluorescence, flexible near-infrared electrochromic devices and theoretical investigation

    KAUST Repository

    Wang, Po-I.

    2016-01-13

    © The Royal Society of Chemistry 2016. In this study, a new triphenylamine-alt-fluorene conjugated copolymer, HPBPYFL6, with hexaphenylbenzene (HPB) and pyrene as asymmetrical pendant groups was synthesized via Suzuki coupling polymerization. The conjugated polymer had a weight-average molecular weight of 5.8 × 104 g mol-1 with a polydispersity index of 2.5 characterized by gel permeation chromatography (GPC). HPBPYFL6 showed good solubility in common organic solvents such as NMP, THF, toluene and dichloromethane at 25°C. In addition, HPBPYFL6 possessed a high glass transition temperature of 260°C and a 10% weight-loss temperature of 503°C in nitrogen. HPBPYFL6 bearing a pyrene moiety had a solvatochromic fluorescence shift from a green to an orange emission as the polarity of the solvent increased. Cyclic voltammetry of HPBPYFL6 films cast onto indium-tin oxide-coated glass (ITO-glass) exhibited two oxidation redox couples at an E1/2 value of 0.82 and 1.17 V versus Ag/Ag+ in an acetonitrile solution. The HPBPYFL6 film on graphene-coated PET had an E1/2 value of 0.24 and 1.12 V. Conjugated polymer films exhibited reversible electrochromic behaviour with a colour change from pale yellow to deep blue upon electrochemical oxidation and high absorbance in the near-infrared (NIR) region. The switching and bleaching times were 5.16 s and 3.12 s for 1231 nm and were 3.30 s and 3.74 s for 1030 nm of HPBPYFL6 on ITO-glass. The strong NIR electrochromic absorbance of HPBPYFL6 was attributed to intervalence charge transfer by the incorporation of the HPB moiety. This phenomenon was confirmed by chemical oxidation as the oxidant contents increased in the solution state. Furthermore, the electrochromic mechanism was interpreted by DFT calculation and the simulated NIR electrochromic spectra of model compound HPBPYFL are in good agreement with the experimental data.

  4. Methionine-pyrene hybrid based fluorescent probe for trace level detection and estimation of Hg(II) in aqueous environmental samples: experimental and computational studies.

    Science.gov (United States)

    Banerjee, Arnab; Karak, Debasis; Sahana, Animesh; Guha, Subarna; Lohar, Sisir; Das, Debasis

    2011-02-15

    A new fluorescent, Hg(2+) selective chemosensor, 4-methylsulfanyl-2-[(pyren-4-ylmethylene)-amino] butyric acid methyl ester (L, MP) was synthesized by blending methionine with pyrene. It was well characterized by different analytical techniques, viz. (1)H NMR, (13)C NMR, QTOF mass spectra, elemental analysis, FTIR and UV-vis spectroscopy. The reaction of this ligand with Hg(2+) was studied by steady state and time-resolved fluorescence spectroscopy. The Hg(2+) complexation process was confirmed by comparing FTIR, UV-vis, thermal, QTOF mass spectra and (1)H NMR data of the product with that of the free ligand values. The composition (Hg(2+):L=1:1) of the Hg(2+) complex in solution was evaluated by fluorescence titration method. Based on the chelation assisted fluorescence quenching, a highly sensitive spectrofluorometric method was developed for the determination of trace amounts of Hg(2+) in water. The ligand had an excitation and emission maxima at 360 nm and 455 nm, respectively. The fluorescence life times of the ligand and its Hg(2+) complex were 1.54 ns and 0.72 ns respectively. The binding constant of the ligand, L with Hg(2+) was calculated using Benesi-Hildebrand equation and was found to be 7.5630×10(4). The linear range of the method was from 0 to 16 μg L(-1) with a detection limit of 0.056 μg L(-1) for Hg(2+). The quantum yields of the ligand and its Hg(2+) complex were found to be 0.1206 and 0.0757 respectively. Both the ligand and its Hg(2+) complex have been studied computationally (Ab-initio, Hartree Fock method) to get their optimized structure and other related physical parameters, including bond lengths, bond angles, dipole moments, orbital interactions etc. The binding sites of the ligand to the Hg(2+) ion as obtained from the theoretical calculations were well supported by (1)H NMR titration. The interference of foreign ions was negligible. This method has been successfully applied to the determination of mercury(II) in industrial waste water

  5. Effect of green tea catechins and hydrolyzable tannins on benzo[a]pyrene-induced DNA adducts and structure-activity relationship.

    Science.gov (United States)

    Cao, Pengxiao; Cai, Jian; Gupta, Ramesh C

    2010-04-19

    Green tea catechins and hydrolyzable tannins are gaining increasing attention as chemopreventive agents. However, their mechanism of action is poorly understood. We investigated the effects of four green tea catechins and two hydrolyzable tannins on microsome-induced benzo[a]pyrene (BP)-DNA adducts and the possible structure-activity relationship. BP (1 microM) was incubated with rat liver microsomes and DNA in the presence of the test compound (1-200 microM) or vehicle. The purified DNA was analyzed by (32)P-postlabeling. The inhibitory activity of the catechins was in the following descending order: epigallocatechin gallate (IC(50) = 16 microM) > epicatechin gallate (24 microM) > epigallocatechin (146 microM) > epicatechin (462 microM), suggesting a correlation between the number of adjacent aromatic hydroxyl groups in the molecular structure and their potencies. Tannic acid (IC(50) = 4 microM) and pentagalloglucose (IC(50) = 26 microM) elicited as much DNA adduct inhibitory activity as the catechins or higher presumably due to the presence of more functional hydroxyl groups. To determine if the activity of these compounds was due to direct interaction of phenolic groups with electrophilic metabolite(s) of BP, DNA was incubated with anti-benzo[a]pyrene-7,8-diol-9,10-epoxide (anti-BPDE) (0.5 microM) in the presence of test compounds (200 microM) or vehicle. Significant inhibition of DNA adduct formation was found (tannic acid > pentagalloglucose > epigallocatechin gallate > epicatechin gallate). This notion was confirmed by analysis of the reaction products of anti-BPDE with the catechins and pentagalloglucose by electrospray ionization mass spectrometry and liquid chromatography-mass spectrometry. In conclusion, our data demonstrate that green tea catechins and the hydrolyzable tannins are highly effective in inhibiting BP-DNA adduct formation at least, in part, due to direct interaction of adjacent hydroxyl groups in their structures and that the activity is

  6. Polycyclic aromatic hydrocarbons as skin carcinogens: Comparison of benzo[a]pyrene, dibenzo[def,p]chrysene and three environmental mixtures in the FVB/N mouse

    Energy Technology Data Exchange (ETDEWEB)

    Siddens, Lisbeth K.; Larkin, Andrew [Department of Environmental and Molecular Toxicology, Oregon State University (United States); Superfund Research Center, Oregon State University (United States); Krueger, Sharon K. [Superfund Research Center, Oregon State University (United States); The Linus Pauling Institute, Oregon State University (United States); Bradfield, Christopher A. [McArdle Laboratory for Cancer Research, University of Wisconsin, Madison, WI 53706 (United States); Waters, Katrina M.; Tilton, Susan C. [Superfund Research Center, Oregon State University (United States); Computational Biology and Bioinformatics Group, Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Pereira, Cliff B. [Superfund Research Center, Oregon State University (United States); Deptartment of Statistics, Oregon State University, Corvallis, OR 97331 (United States); Environmental Health Sciences Center, Oregon State University, Corvallis, OR 97331 (United States); Löhr, Christiane V. [Environmental Health Sciences Center, Oregon State University, Corvallis, OR 97331 (United States); College of Veterinary Medicine, Oregon State University, Corvallis, OR 97331 (United States); Arlt, Volker M.; Phillips, David H. [Analytical and Environmental Sciences Division, MRC-HPA Centre for Environment and Health, King' s College London, London SE1 9NH (United Kingdom); Williams, David E., E-mail: david.williams@oregonstate.edu [Department of Environmental and Molecular Toxicology, Oregon State University (United States); Superfund Research Center, Oregon State University (United States); The Linus Pauling Institute, Oregon State University (United States); Environmental Health Sciences Center, Oregon State University, Corvallis, OR 97331 (United States); and others

    2012-11-01

    The polycyclic aromatic hydrocarbon (PAH), benzo[a]pyrene (BaP), was compared to dibenzo[def,p]chrysene (DBC) and combinations of three environmental PAH mixtures (coal tar, diesel particulate and cigarette smoke condensate) using a two stage, FVB/N mouse skin tumor model. DBC (4 nmol) was most potent, reaching 100% tumor incidence with a shorter latency to tumor formation, less than 20 weeks of 12-O-tetradecanoylphorbol-13-acetate (TPA) promotion compared to all other treatments. Multiplicity was 4 times greater than BaP (400 nmol). Both PAHs produced primarily papillomas followed by squamous cell carcinoma and carcinoma in situ. Diesel particulate extract (1 mg SRM 1650b; mix 1) did not differ from toluene controls and failed to elicit a carcinogenic response. Addition of coal tar extract (1 mg SRM 1597a; mix 2) produced a response similar to BaP. Further addition of 2 mg of cigarette smoke condensate (mix 3) did not alter the response with mix 2. PAH-DNA adducts measured in epidermis 12 h post initiation and analyzed by {sup 32}P post‐labeling, did not correlate with tumor incidence. PAH‐dependent alteration in transcriptome of skin 12 h post initiation was assessed by microarray. Principal component analysis (sum of all treatments) of the 922 significantly altered genes (p < 0.05), showed DBC and BaP to cluster distinct from PAH mixtures and each other. BaP and mixtures up-regulated phase 1 and phase 2 metabolizing enzymes while DBC did not. The carcinogenicity with DBC and two of the mixtures was much greater than would be predicted based on published Relative Potency Factors (RPFs). -- Highlights: ► Dibenzo[def,p]chrysene (DBC), 3 PAH mixtures, benzo[a]pyrene (BaP) were compared. ► DBC and 2 PAH mixtures were more potent than Relative Potency Factor estimates. ► Transcriptome profiles 12 hours post initiation were analyzed by microarray. ► Principle components analysis of alterations revealed treatment-based clustering. ► DBC gave a unique

  7. Black raspberry extracts inhibit benzo(a)pyrene diol-epoxide-induced activator protein 1 activation and VEGF transcription by targeting the phosphotidylinositol 3-kinase/Akt pathway.

    Science.gov (United States)

    Huang, Chuanshu; Li, Jingxia; Song, Lun; Zhang, Dongyun; Tong, Qiangsong; Ding, Min; Bowman, Linda; Aziz, Robeena; Stoner, Gary D

    2006-01-01

    Previous studies have shown that freeze-dried black raspberry extract fractions inhibit benzo(a)pyrene [B(a)P]-induced transformation of Syrian hamster embryo cells and benzo(a)pyrene diol-epoxide [B(a)PDE]-induced activator protein-1 (AP-1) activity in mouse epidermal Cl 41 cells. The phosphotidylinositol 3-kinase (PI-3K)/Akt pathway is critical for B(a)PDE-induced AP-1 activation in mouse epidermal Cl 41 cells. In the present study, we determined the potential involvement of PI-3K and its downstream kinases on the inhibition of AP-1 activation by black raspberry fractions, RO-FOO3, RO-FOO4, RO-ME, and RO-DM. In addition, we investigated the effects of these fractions on the expression of the AP-1 target genes, vascular endothelial growth factor (VEGF) and inducible nitric oxide synthase (iNOS). Pretreatment of Cl 41 cells with fractions RO-F003 and RO-ME reduced activation of AP-1 and the expression of VEGF, but not iNOS. In contrast, fractions RO-F004 and RO-DM had no effect on AP-1 activation or the expression of either VEGF or iNOS. Consistent with inhibition of AP-1 activation, the RO-ME fraction markedly inhibited activation of PI-3K, Akt, and p70 S6 kinase (p70(S6k)). In addition, overexpression of the dominant negative PI-3K mutant delta p85 reduced the induction of VEGF by B(a)PDE. It is likely that the inhibitory effects of fractions RO-FOO3 and RO-ME on B(a)PDE-induced AP-1 activation and VEGF expression are mediated by inhibition of the PI-3K/Akt pathway. In view of the important roles of AP-1 and VEGF in tumor development, one mechanism for the chemopreventive activity of black raspberries may be inhibition of the PI-3K/Akt/AP-1/VEGF pathway.

  8. The expressions of protooncogenes and CYP1A in lungs of rats exposed to sulfur dioxide and benzo(a)pyrene.

    Science.gov (United States)

    Qin, Guohua; Meng, Ziqiang

    2006-06-01

    Sulfur dioxide (SO2) is a ubiquitous air pollutant, present in low concentrations in the urban air, and in higher concentrations in the working environment. Benzo(a)pyrene (B(a)P), a polycyclic aromatic hydrocarbon, is a ubiquitous environmental contaminant with diverse toxicological effects. To investigate the interactions between SO2 and B(a)P, male Wistar rats were exposed to intratracheally instilled with benzo(a)pyrene (B(a)P; 3 mg) or SO2 (20 ppm) inhalation alone or together. The mRNA of CYP1A1 and 1A2, c-fos, and c-jun and protein levels of c-fos and c-jun were analyzed in lungs using a real-time reverse transcription-polymerase chain reaction (real-time RT-PCR) assay and Western blot analysis, respectively. And 7-ethoxyresorufin O-deethylase (EROD) and methoxyresorufin O-demethylase (MROD) activities were detected. In lungs of rats exposed to SO2 alone, the gene transcription of CYP1A1 and 1A2, the EROD and MROD activities were decreased. Meanwhile, the mRNA and protein levels of c-jun and c-fos were increased significantly. Exposure to B(a)P alone induced CYP1A1, CYP1A2 mRNA levels, the protein levels of c-jun, and the EROD and MROD activities in lungs. However, exposure to B(a)P plus inhaled SO2 neither increased nor decreased CYP1A1/2 mRNA expressions, EROD, and MROD activities in lungs, versus exposure to B(a)P alone. Nevertheless, exposure to B(a)P plus inhaled SO2 increased the mRNA and protein levels of c-jun and c-fos in lungs compared with lungs exposed to SO2 alone. Accordingly, the SO2-induced decreases of CYP1A1/2 might not influence the metabolic activation of B(a)P. However, when B(a)P and SO2 were given in the combinations, one might postulate that a synergistic effect on the expressions of c-fos and c-jun between SO2 and B(a)P, which might be one of the possible mechanisms of combination effects between B(a)P and the air pollutants.

  9. Environmental Distributions of Benzo[a]pyrene in China: Current and Future Emission Reduction Scenarios Explored Using a Spatially Explicit Multimedia Fate Model.

    Science.gov (United States)

    Zhu, Ying; Tao, Shu; Price, Oliver R; Shen, Huizhong; Jones, Kevin C; Sweetman, Andrew J

    2015-12-01

    SESAMe v3.0, a spatially explicit multimedia fate model with 50 × 50 km(2) resolution, has been developed for China to predict environmental concentrations of benzo[a]pyrene (BaP) using an atmospheric emission inventory for 2007. Model predictions are compared with environmental monitoring data obtained from an extensive review of the literature. The model performs well in predicting multimedia concentrations and distributions. Predicted concentrations are compared with guideline values; highest values with some exceedances occur mainly in the North China Plain, Mid Inner Mongolia, and parts of three northeast provinces, Xi'an, Shanghai, and south of Jiangsu province, East Sichuan Basin, middle of Guizhou and Guangzhou. Two potential future scenarios have been assessed using SESAMe v3.0 for 2030 as BaP emission is reduced by (1) technological improvement for coal consumption in energy production and industry sectors in Scenario 1 (Sc1) and (2) technological improvement and control of indoor biomass burning for cooking and indoor space heating and prohibition of open burning of biomass in 2030 in Scenario 2 (Sc2). Sc2 is more efficient in reducing the areas with exceedance of guideline values. Use of SESAMe v3.0 provides insights on future research needs and can inform decision making on options for source reduction.

  10. Assessment of Industry-Induced Urban Human Health Risks Related to Benzo[a]pyrene based on a Multimedia Fugacity Model: Case Study of Nanjing, China

    Directory of Open Access Journals (Sweden)

    Linyu Xu

    2015-05-01

    Full Text Available Large amounts of organic pollutants emitted from industries have accumulated and caused serious human health risks, especially in urban areas with rapid industrialization. This paper focused on the carcinogen benzo[a]pyrene (BaP from industrial effluent and gaseous emissions, and established a multi-pathway exposure model based on a Level IV multimedia fugacity model to analyze the human health risks in a city that has undergone rapid industrialization. In this study, GIS tools combined with land-use data was introduced to analyze smaller spatial scales so as to enhance the spatial resolution of the results. An uncertainty analysis using a Monte Carlo simulation was also conducted to illustrate the rationale of the probabilistic assessment mode rather than deterministic assessment. Finally, the results of the case study in Nanjing, China indicated the annual average human cancer risk induced by local industrial emissions during 2002–2008 (lowest at 1.99´10–6 in 2008 and highest at 3.34´10–6 in 2004, which was lower than the USEPA prescriptive level (1´10–6–1´10–4 but cannot be neglected in the long term. The study results could not only instruct the BaP health risk management but also help future health risk prediction and control.

  11. Molecular cloning and differential expression patterns of sigma and omega glutathione S-transferases from Venerupis philippinarum to heavy metals and benzo[a]pyrene exposure

    Science.gov (United States)

    Zhang, Linbao; Wu, Huifeng; Liu, Xiaoli; Chen, Leilei; Wang, Qing; Zhao, Jianmin; You, Liping

    2012-05-01

    Glutathione S-transferases (GSTs) are a class of enzymes that facilitate the detoxification of xenobiotics, and also play important roles in antioxidant defense. We identified two glutathione S-transferase isoforms (VpGSTS, sigma GST; VpGSTO, omega GST) from Venerupis philippinarum by RACE approaches. The open reading frames of VpGSTS and VpGSTO were of 612 bp and 729 bp, encoding 203 and 242 amino acids with an estimated molecular mass of 22.88 and 27.94 kDa, respectively. The expression profiles of VpGSTS and VpGSTO responded to heavy metals and benzo[a]pyrene (B[a]P) exposure were investigated by quantitative real-time RT-PCR. The expression of VpGSTS and VpGSTO were both rapidly up-regulated, however, they showed differential expression patterns to different toxicants. Cd displayed stronger induction of VpGSTS expression with an approximately 12-fold increase than that of VpGSTO with a maximum 6.4-fold rise. Cu exposure resulted in similar expression patterns for both VpGSTS and VpGSTO. For B[a]P exposure, the maximum induction of VpGSTO was approximately two times higher than that of VpGSTS. Altogether, these findings implied the involvement of VpGSTS and VpGSTO in host antioxidant responses, and highlighted their potential as a biomarker to Cd and B[a]P exposure.

  12. Rapid and sensitive determination of benzo[a]pyrene in black ginseng using fluorescence detector and high performance liquid chromatography-tandem mass spectrometry

    Science.gov (United States)

    Cho, Hyun-jeong; Kim, Hye-jin; Son, Byeong-cheol; Jo, Dong-keun; Cho, Byung-lim

    2013-05-01

    Black ginseng is produced by steaming a ginseng root followed by drying repeatedly 9 times during the process and it is changed to be black color, so it is known that a black ginseng has more contents of saponins than red ginseng. However a fake black ginseng which is produced to be black color at high temperature in a short period of time generate carcinogenic benzo[a]pyrene(BaP) through the process. In this year, maximum residue level(MRL) for BaP was established to 2 ug/kg in black ginseng and more sensitive method was developed to quantitatively analyze the BaP by high performance liquid chromatography (HPLC) coupling with florescence detector and tandem mass spectrometry (atmospheric pressure chemical ionization-MS/MS). Chromatographic separation was performed on a Supelcosil™ LC-PAH column (3 μm, 3 mm x 50 mm). Mobile phase A was water and mobile phase B was acetonitrile. BaP was exactly separated from other 15 polycyclic aromatic hydrocarbons (PAHs) which have been selected as priority pollutants by the US Environmental Protection Agency (EPA). Linearity of detection was in the range of 0.2~20 μg/kg and limit of detection (LOD) for BaP was lower than 0.1 μg/kg, limit of quantification (LOQ) was 0.2 μg/kg. The recovery of Bap was 92.54%+/-6.3% in black ginseng.

  13. Benzo[a]pyrene induced p53-mediated cell cycle arrest, DNA repair, and apoptosis pathways in Chinese rare minnow (Gobiocypris rarus).

    Science.gov (United States)

    Yuan, Lilai; Lv, Biping; Zha, Jinmiao; Wang, Zijian

    2017-03-01

    The p53 pathways play an important role in carcinogenesis. In mammals, p53 and p53 target genes have been extensively studied, but little is known about their functions and regulation in fish. In this study, the cDNA fragments of p53 network genes, including p53, p21, mdm2, gadd45α, gadd45β, igfbp-3, and bax, were cloned from Chinese rare minnow (Gobiocypris rarus). These genes displayed high amino acid sequence identities with their zebrafish orthologs. The mRNA levels of p53 network genes and pathological changes in the liver were determined after adult rare minnow were exposed to 0.4, 2, and 10 µg/L of benzo[a]pyrene (BaP) for 28 days. The results showed that p53, p21, mdm2, gadd45α, and bax mRNA expressions in the livers from males and females were significantly upregulated compared with those of the controls (p p53 network genes in the livers suggest that rare minnow is suitable as an experimental fish to screen environmental carcinogens. In addition, the p53 network genes in rare minnow could feasibly be used to identify the mechanism of environmental carcinogenesis. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 979-988, 2017.

  14. Immune response signatures of benzo{alpha}pyrene exposure in normal human mammary epithelial cells in the absence or presence of chlorophyllin.

    Science.gov (United States)

    John, Kaarthik; Keshava, Channa; Richardson, Diana L; Weston, Ainsley; Nath, Joginder

    2009-01-01

    Carcinogenic polycylic aromatic hydrocarbons can alter immune responses. Changes in immune response gene expression profiles in multiple human mammary cell strains exposed to benzo(alpha)pyrene (BP) (4 microM) in vitro, in the presence or absence of chlorophyllin (5 microM), were observed using Affymetrix gene arrays. Expressions of five immune response genes were altered ~3.0-fold by BP exposure and 24 genes by BP in the presence chlorophyllin. In silico pathway analysis revealed altered immune response genes form interactive gene networks with many cellular processes, suggesting their role in a complex multigenic response to toxins. Additionally, it was suggestive of the possible immunomodulatory potential of chlorophyllin apart from various other well-documented mechanisms of action. Gene expression matrices revealed consistent alteration patterns involving IL1B, SECTM1 and CXCL14 on exposure to BP, and IL1RN, CD86, IF144 and GIP2 in the presence of chlorophyllin and BP, suggesting some of these genes might constitute putative immune response biomarkers of PAH exposure. This study has therefore identified a battery of potential immune response biomarkers of PAH exposure, amidst several genes, for future validation studies.

  15. Transcriptional profiles of benzo(a)pyrene exposure in normal human mammary epithelial cells in the absence or presence of chlorophyllin.

    Science.gov (United States)

    John, Kaarthik; Keshava, Channa; Richardson, Diana L; Weston, Ainsley; Nath, Joginder

    2008-04-02

    Benzo(a)pyrene (BP) exposure causes alterations in gene expression in normal human mammary epithelial cells (NHMECs). This study used Affymetrix Hu-Gene133A arrays, with 14,500 genes represented, to evaluate modulation of BP-induced gene expression by chlorophyllin in six NHMEC strains derived from different donors. A major goal was to seek potential biomarkers of carcinogen exposure and how they behave in the presence of a chemopreventive agent. NHMECs (passage 6 and 70% confluence) were exposed for 24h to either vehicle control, or BP, or chlorophyllin followed by BP and chlorophyllin together. BP exposure resulted in approximately 3-fold altered expression of 49 genes in at least one of the six NHMEC strains. When cells were exposed to chlorophyllin pre-treatment followed by BP plus chlorophyllin, expression of 125 genes was similarly altered. Genes in the functional categories of xenobiotic metabolism, cell signaling, cell motility, cell proliferation, cellular transcription, metabolism, cell cycle control, apoptosis and DNA repair were identified. Only CYP1B1 and ALDH1A3 were consistently up-regulated by approximately 3-fold in most of the cell strains (at least 4) when exposed to BP. Cluster analysis identified a suite of 13 genes induced by BP where induction was mitigated in the presence of chlorophyllin. Additionally, cluster analysis identified a suite of 16 genes down-regulated by BP where induction was partially restored in the presence of chlorophyllin.

  16. Transcriptional profiles of benzo(a)pyrene exposure in normal human mammary epithelial cells in the absence or presence of chlorophyllin

    Energy Technology Data Exchange (ETDEWEB)

    John, Kaarthik [Genetics and Developmental Biology Program, 1120 Agricultural Sciences Building, West Virginia University, Morgantown, WV 26506-6108 (United States); Toxicology and Molecular Biology Laboratory, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia (United States); Keshava, Channa; Richardson, Diana L. [Toxicology and Molecular Biology Laboratory, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia (United States); Weston, Ainsley [Genetics and Developmental Biology Program, 1120 Agricultural Sciences Building, West Virginia University, Morgantown, WV 26506-6108 (United States); Toxicology and Molecular Biology Laboratory, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia (United States); Nath, Joginder [Genetics and Developmental Biology Program, 1120 Agricultural Sciences Building, West Virginia University, Morgantown, WV 26506-6108 (United States)], E-mail: jnath@wvu.edu

    2008-04-02

    Benzo(a)pyrene (BP) exposure causes alterations in gene expression in normal human mammary epithelial cells (NHMECs). This study used Affymetrix Hu-Gene133A arrays, with 14,500 genes represented, to evaluate modulation of BP-induced gene expression by chlorophyllin in six NHMEC strains derived from different donors. A major goal was to seek potential biomarkers of carcinogen exposure and how they behave in the presence of a chemopreventive agent. NHMECs (passage 6 and 70% confluence) were exposed for 24 h to either vehicle control, or BP, or chlorophyllin followed by BP and chlorophyllin together. BP exposure resulted in approximately 3-fold altered expression of 49 genes in at least one of the six NHMEC strains. When cells were exposed to chlorophyllin pre-treatment followed by BP plus chlorophyllin, expression of 125 genes was similarly altered. Genes in the functional categories of xenobiotic metabolism, cell signaling, cell motility, cell proliferation, cellular transcription, metabolism, cell cycle control, apoptosis and DNA repair were identified. Only CYP1B1 and ALDH1A3 were consistently up-regulated by {approx}3-fold in most of the cell strains (at least 4) when exposed to BP. Cluster analysis identified a suite of 13 genes induced by BP where induction was mitigated in the presence of chlorophyllin. Additionally, cluster analysis identified a suite of 16 genes down-regulated by BP where induction was partially restored in the presence of chlorophyllin.

  17. Effects of quantity, quality, and contact time of dissolved organic matter on bioconcentration of benzo[a]pyrene in the nematode Caenorhabditis elegans

    Energy Technology Data Exchange (ETDEWEB)

    Haitzer, M.; Hoess, S. [Ludwig Maximilians Univ. Muenchen (Germany). Zoologisches Inst.]|[Inst. fuer Gewaesseroekologie und Binnenfischerei, Berlin (Germany); Burnison, B.K. [Environment Canada, Burlington, Ontario (Canada). National Water Research Inst.; Traunspurger, W. [Ludwig Maximilians Univ. Muenchen (Germany). Zoologisches Inst.; Ste