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Sample records for sulfate ester formation

  1. Chondroitin Sulfate Perlecan Enhances Collagen Fibril Formation

    DEFF Research Database (Denmark)

    Kvist, A. J.; Johnson, A. E.; Mörgelin, M.

    2006-01-01

    in collagen type II fibril assembly by perlecan-null chondrocytes. Cartilage perlecan is a heparin sulfate or a mixed heparan sulfate/chondroitin sulfate proteoglycan. The latter form binds collagen and accelerates fibril formation in vitro, with more defined fibril morphology and increased fibril diameters...... produced in the presence of perlecan. Interestingly, the enhancement of collagen fibril formation is independent on the core protein and is mimicked by chondroitin sulfate E but neither by chondroitin sulfate D nor dextran sulfate. Furthermore, perlecan chondroitin sulfate contains the 4,6-disulfated...... disaccharides typical for chondroitin sulfate E. Indeed, purified glycosaminoglycans from perlecan-enriched fractions of cartilage extracts contain elevated levels of 4,6-disulfated chondroitin sulfate disaccharides and enhance collagen fibril formation. The effect on collagen assembly is proportional...

  2. Formation of the natural sulfate aerosol

    Energy Technology Data Exchange (ETDEWEB)

    Kerminen, V.M.; Hillamo, R.; Maekinen, M.; Virkkula, A.; Maekelae, T.; Pakkanen, T. [Helsinki Univ. (Finland). Dept. of Physics

    1996-12-31

    Anthropogenic sulfate aerosol, together with particles from biomass burning, may significantly reduce the climatic warming due to man-made greenhouse gases. The radiative forcing of aerosol particles is based on their ability to scatter and absorb solar radiation (direct effect), and on their influences on cloud albedos and lifetimes (indirect effect). The direct aerosol effect depends strongly on the size, number and chemical composition of particles, being greatest for particles of 0.1-1 {mu}m in diameter. The indirect aerosol effect is dictated by the number of particles being able to act as cloud condensation nuclei (CCN). For sulfate particles, the minimum CCN size in tropospheric clouds is of the order of 0.05-0.2 {mu}m. To improve aerosol parameterizations in future climate models, it is required that (1) both primary and secondary sources of various particle types will be characterized at a greater accuracy, and (2) the influences of various atmospheric processes on the spatial and temporal distribution of these particles and their physico-chemical properties are known much better than at the present. In estimating the climatic forcing due to the sulfate particles, one of the major problems is to distinguish between sulfur from anthropogenic sources and that of natural origin. Global emissions of biogenic and anthropogenic sulfate pre-cursors are comparable in magnitude, but over regional scales either of these two source types may dominate. The current presentation is devoted to discussing the natural sulfate aerosol, including the formation of sulfur-derived particles in the marine environment, and the use of particulate methanesulfonic acid (MSA) as a tracer for the natural sulfate

  3. Fucoidan cytotoxicity against human breast cancer T47D cell line increases with higher level of sulfate ester group

    Science.gov (United States)

    Saepudin, Endang; Alfita Qosthalani, Fildzah; Sinurat, Ellya

    2018-01-01

    The anticancer activity of different sulfate ester group content in different molecular weight was examined. The anticancer activity was achieved in vitro on human breast cancer T47D cell line. Fucoidan with lower molecular weight (5.79 kDa) tends to have lower sulfate ester group content (8.69%) and resulted in higher IC50 value (184.22 μg/mL). While fucoidan with higher molecular weight (785.12 kDa) tends to have higher sulfate level (18.63%) and achieved lower IC50 value (75.69 μg/mL). The result showed that in order to maintain fucoidan cytotoxic activity against human breast cancer T47D cell line, the sulfate content should be remain high. Keywords: fucoidan, sulfate ester group, human breast cancer

  4. Synthetic Methods for Ester Bond Formation and Conformational Analysis of Ester-Containing Carbohydrates

    Science.gov (United States)

    Hackbusch, Sven

    This dissertation encompasses work related to synthetic methods for the formation of ester linkages in organic compounds, as well as the investigation of the conformational influence of the ester functional group on the flexibility of inter-saccharide linkages, specifically, and the solution phase structure of ester-containing carbohydrate derivatives, in general. Stereoselective reactions are an important part of the field of asymmetric synthesis and an understanding of their underlying mechanistic principles is essential for rational method development. Here, the exploration of a diastereoselective O-acylation reaction on a trans-2-substituted cyclohexanol scaffold is presented, along with possible reasons for the observed reversal of stereoselectivity dependent on the presence or absence of an achiral amine catalyst. In particular, this work establishes a structure-activity relationship with regard to the trans-2-substituent and its role as a chiral auxiliary in the reversal of diastereoselectivity. In the second part, the synthesis of various ester-linked carbohydrate derivatives, and their conformational analysis is presented. Using multidimensional NMR experiments and computational methods, the compounds' solution-phase structures were established and the effect of the ester functional group on the molecules' flexibility and three-dimensional (3D) structure was investigated and compared to ether or glycosidic linkages. To aid in this, a novel Karplus equation for the C(sp2)OCH angle in ester-linked carbohydrates was developed on the basis of a model ester-linked carbohydrate. This equation describes the sinusoidal relationship between the C(sp2)OCH dihedral angle and the corresponding 3JCH coupling constant that can be determined from a J-HMBC NMR experiment. The insights from this research will be useful in describing the 3D structure of naturally occurring and lab-made ester-linked derivatives of carbohydrates, as well as guiding the de novo-design of

  5. Complex formation of technetium with the methyl esters of MAG2 and MAG1

    International Nuclear Information System (INIS)

    Noll, B.; Noll, S.; Grosse, B.; Johannsen, B.; Spies, H.

    1993-01-01

    Mercaptoacetylglycine methyl ester (MAG 2 ester) and mercaptoacetyldiglycine methyl ester (MAG 1 ester) were included to investigate complex formation of SH/amide ligands with technetium. The studies are aimed at finding out how blocking the carboxylic groups influences the complexation reaction, with a view to finding an approach to new lipophilic species. (orig./BBR)

  6. Persistent sulfate formation from London Fog to Chinese haze.

    Science.gov (United States)

    Wang, Gehui; Zhang, Renyi; Gomez, Mario E; Yang, Lingxiao; Levy Zamora, Misti; Hu, Min; Lin, Yun; Peng, Jianfei; Guo, Song; Meng, Jingjing; Li, Jianjun; Cheng, Chunlei; Hu, Tafeng; Ren, Yanqin; Wang, Yuesi; Gao, Jian; Cao, Junji; An, Zhisheng; Zhou, Weijian; Li, Guohui; Wang, Jiayuan; Tian, Pengfei; Marrero-Ortiz, Wilmarie; Secrest, Jeremiah; Du, Zhuofei; Zheng, Jing; Shang, Dongjie; Zeng, Limin; Shao, Min; Wang, Weigang; Huang, Yao; Wang, Yuan; Zhu, Yujiao; Li, Yixin; Hu, Jiaxi; Pan, Bowen; Cai, Li; Cheng, Yuting; Ji, Yuemeng; Zhang, Fang; Rosenfeld, Daniel; Liss, Peter S; Duce, Robert A; Kolb, Charles E; Molina, Mario J

    2016-11-29

    Sulfate aerosols exert profound impacts on human and ecosystem health, weather, and climate, but their formation mechanism remains uncertain. Atmospheric models consistently underpredict sulfate levels under diverse environmental conditions. From atmospheric measurements in two Chinese megacities and complementary laboratory experiments, we show that the aqueous oxidation of SO 2 by NO 2 is key to efficient sulfate formation but is only feasible under two atmospheric conditions: on fine aerosols with high relative humidity and NH 3 neutralization or under cloud conditions. Under polluted environments, this SO 2 oxidation process leads to large sulfate production rates and promotes formation of nitrate and organic matter on aqueous particles, exacerbating severe haze development. Effective haze mitigation is achievable by intervening in the sulfate formation process with enforced NH 3 and NO 2 control measures. In addition to explaining the polluted episodes currently occurring in China and during the 1952 London Fog, this sulfate production mechanism is widespread, and our results suggest a way to tackle this growing problem in China and much of the developing world.

  7. Sugar fatty acid esters inhibit biofilm formation by food-borne pathogenic bacteria

    Science.gov (United States)

    Furukawa, Soichi; Akiyoshi, Yuko; O’Toole, George A.; Ogihara, Hirokazu; Morinaga, Yasushi

    2010-01-01

    Effects of food additives on biofilm formation by food-borne pathogenic bacteria were investigated. Thirty-three potential food additives and 3 related compounds were added to the culture medium at concentrations from 0.001 to 0.1% (w/w), followed by inoculation and cultivation of five biofilm-forming bacterial strains for the evaluation of biofilm formation. Among the tested food additives, 21 showed inhibitory effects of biofilm formation by Staphylococcus aureus and Escherichia coli, and in particular, sugar fatty acid esters showed significant anti-biofilm activity. Sugar fatty acid esters with long chain fatty acid residues (C14-16) exerted their inhibitory effect at the concentration of 0.001%(w/w), but bacterial growth was not affected at this low concentration. Activities of the sugar fatty acid esters positively correlated with the increase of the chain length of the fatty acid residues. Sugar fatty acid esters inhibited the initial attachment of the Staphylococcus aureus cells to the abiotic surface. Sugar fatty acid esters with long chain fatty acid residues (C14-16) also inhibited biofilm formation by Streptococcus mutans and Listeria monocytogenes at 0.01%(w/w), while the inhibition of biofilm formation by Pseudomonas aeruginosa required the addition of a far higher concentration (0.1%(w/w)) of the sugar fatty acid esters. PMID:20089325

  8. Other factors to consider in the formation of chloropropandiol fatty esters in oil processes.

    Science.gov (United States)

    Ramli, Muhamad Roddy; Siew, Wai Lin; Ibrahim, Nuzul Amri; Kuntom, Ainie; Abd Razak, Raznim Arni

    2015-01-01

    This paper examines the processing steps of extracting palm oil from fresh fruit bunches in a way that may impact on the formation of chloropropandiol fatty esters (3-MCPD esters), particularly during refining. Diacylglycerols (DAGs) do not appear to be a critical factor when crude palm oils are extracted from various qualities of fruit bunches. Highly hydrolysed oils, in spite of the high free fatty acid (FFA) contents, did not show exceptionally high DAGs, and the oils did not display a higher formation of 3-MCPD esters upon heat treatment. However, acidity measured in terms of pH appears to have a strong impact on 3-MCPD ester formation in the crude oil when heated at high temperatures. The differences in the extraction process of crude palm oil from current commercial processes and that from a modified experimental process showed clearly the effect of acidity of the oil on the formation of 3-MCPD esters. This paper concludes that the washing or dilution step in palm oil mills removes the acidity of the vegetative materials and that a well-optimised dilution/washing step in the extraction process will play an important role in reducing formation of 3-MCPD esters in crude palm oil upon further heat processing.

  9. Antioxidants Inhibit Formation of 3-Monochloropropane-1,2-diol Esters in Model Reactions.

    Science.gov (United States)

    Li, Chang; Jia, Hanbing; Shen, Mingyue; Wang, Yuting; Nie, Shaoping; Chen, Yi; Zhou, Yongqiang; Wang, Yuanxing; Xie, Mingyong

    2015-11-11

    The capacities of six antioxidants to inhibit the formation of 3-monochloropropane-1,2 diol (3-MCPD) esters were examined in this study. Inhibitory capacities of the antioxidants were investigated both in chemical models containing the precursors (tripalmitoyl glycerol, 1,2-dipalmitoyl-sn-glycerol, monopalmitoyl glycerol, and sodium chloride) of 3-MCPD esters and in oil models (rapeseed oil and sodium chloride). Six antioxidants, butylated hydroxytoluene (BHT), butylated hydroxy anisole (BHA), tert-butyl hydroquinone (TBHQ), propyl gallate (PG), L-ascorbyl palmitate (AP), and α-tocopherol (VE), were found to exhibit inhibiting capacities on 3-MCPD ester formation both in chemical models and in oil models. TBHQ provided the highest inhibitory capacity both in chemical models and in oil models; 44% of 3-MCPD ester formation was inhibited in the presence of TBHQ (66 mg/kg of oil) after heating of rapeseed oil at 230 °C for 30 min, followed by PG and AP. BHT, BHA, and VE appeared to have weaker inhibitory abilities in both models. VE exhibited the lowest inhibition rate; 22% of 3-MCPD esters were inhibited in the presence of VE (172 mg/kg of oil) after heating of rapeseed oil at 230 °C for 30 min. In addition, the inhibition rates of PG and VE decreased dramatically with an increase in temperature or heating time. The results suggested that some antioxidants, such as TBHQ, PG, and AP, could be the potential inhibitors of 3-MCPD esters in practice.

  10. Importance of sulfate radical anion formation and chemistry in heterogeneous OH oxidation of sodium methyl sulfate, the smallest organosulfate

    Directory of Open Access Journals (Sweden)

    K. C. Kwong

    2018-02-01

    Full Text Available Organosulfates are important organosulfur compounds present in atmospheric particles. While the abundance, composition, and formation mechanisms of organosulfates have been extensively investigated, it remains unclear how they transform and evolve throughout their atmospheric lifetime. To acquire a fundamental understanding of how organosulfates chemically transform in the atmosphere, this work investigates the heterogeneous OH radical-initiated oxidation of sodium methyl sulfate (CH3SO4Na droplets, the smallest organosulfate detected in atmospheric particles, using an aerosol flow tube reactor at a high relative humidity (RH of 85 %. Aerosol mass spectra measured by a soft atmospheric pressure ionization source (direct analysis in real time, DART coupled with a high-resolution mass spectrometer showed that neither functionalization nor fragmentation products are detected. Instead, the ion signal intensity of the bisulfate ion (HSO4− has been found to increase significantly after OH oxidation. We postulate that sodium methyl sulfate tends to fragment into a formaldehyde (CH2O and a sulfate radical anion (SO4 ⋅ − upon OH oxidation. The formaldehyde is likely partitioned back to the gas phase due to its high volatility. The sulfate radical anion, similar to OH radical, can abstract a hydrogen atom from neighboring sodium methyl sulfate to form the bisulfate ion, contributing to the secondary chemistry. Kinetic measurements show that the heterogeneous OH reaction rate constant, k, is (3.79 ± 0.19  ×  10−13 cm3 molecule−1 s−1 with an effective OH uptake coefficient, γeff, of 0.17 ± 0.03. While about 40 % of sodium methyl sulfate is being oxidized at the maximum OH exposure (1.27  ×  1012 molecule cm−3 s, only a 3 % decrease in particle diameter is observed. This can be attributed to a small fraction of particle mass lost via the formation and volatilization of formaldehyde. Overall, we

  11. Importance of sulfate radical anion formation and chemistry in heterogeneous OH oxidation of sodium methyl sulfate, the smallest organosulfate

    Science.gov (United States)

    Chung Kwong, Kai; Chim, Man Mei; Davies, James F.; Wilson, Kevin R.; Nin Chan, Man

    2018-02-01

    Organosulfates are important organosulfur compounds present in atmospheric particles. While the abundance, composition, and formation mechanisms of organosulfates have been extensively investigated, it remains unclear how they transform and evolve throughout their atmospheric lifetime. To acquire a fundamental understanding of how organosulfates chemically transform in the atmosphere, this work investigates the heterogeneous OH radical-initiated oxidation of sodium methyl sulfate (CH3SO4Na) droplets, the smallest organosulfate detected in atmospheric particles, using an aerosol flow tube reactor at a high relative humidity (RH) of 85 %. Aerosol mass spectra measured by a soft atmospheric pressure ionization source (direct analysis in real time, DART) coupled with a high-resolution mass spectrometer showed that neither functionalization nor fragmentation products are detected. Instead, the ion signal intensity of the bisulfate ion (HSO4-) has been found to increase significantly after OH oxidation. We postulate that sodium methyl sulfate tends to fragment into a formaldehyde (CH2O) and a sulfate radical anion (SO4 ṡ -) upon OH oxidation. The formaldehyde is likely partitioned back to the gas phase due to its high volatility. The sulfate radical anion, similar to OH radical, can abstract a hydrogen atom from neighboring sodium methyl sulfate to form the bisulfate ion, contributing to the secondary chemistry. Kinetic measurements show that the heterogeneous OH reaction rate constant, k, is (3.79 ± 0.19) × 10-13 cm3 molecule-1 s-1 with an effective OH uptake coefficient, γeff, of 0.17 ± 0.03. While about 40 % of sodium methyl sulfate is being oxidized at the maximum OH exposure (1.27 × 1012 molecule cm-3 s), only a 3 % decrease in particle diameter is observed. This can be attributed to a small fraction of particle mass lost via the formation and volatilization of formaldehyde. Overall, we firstly demonstrate that the heterogeneous OH oxidation of an

  12. Formation and occurrence of dimer esters of pinene oxidation products in atmospheric aerosols

    DEFF Research Database (Denmark)

    Kristensen, K.; Enggrob, Kirsten; King, Stephanie Michelle

    2013-01-01

    The formation of carboxylic acids and dimer esters from alpha-pinene oxidation was investigated in a smog chamber and in ambient aerosol samples collected during the Biosphere Effects on Aerosols and Photochemistry Experiment (BEARPEX). Chamber experiments of alpha-pinene ozonolysis in dry air...... precursors. However, the sampling time resolution precluded conclusive evidence regarding formation from gas- or particle-phase processes. CCN activities of the particles formed in the smog chamber displayed a modest variation during the course of experiments, with kappa values in the range 0......-diaterpenyl ester was found at higher concentrations under higher temperature conditions, both in the smog-chamber study and in ambient air aerosol samples, and exhibited much higher concentrations at night relative to day-time in line with previous results. We conclude that analysis of pinyl dimer esters provides...

  13. New Insights on Degumming and Bleaching Process Parameters on The Formation of 3-Monochloropropane-1,2-Diol Esters and Glycidyl Esters in Refined, Bleached, Deodorized Palm Oil.

    Science.gov (United States)

    Sim, Biow Ing; Muhamad, Halimah; Lai, Oi Ming; Abas, Faridah; Yeoh, Chee Beng; Nehdi, Imededdine Arbi; Khor, Yih Phing; Tan, Chin Ping

    2018-04-01

    This paper examines the interactions of degumming and bleaching processes as well as their influences on the formation of 3-monochloropropane-1,2-diol esters (3-MCPDE) and glycidyl esters in refined, bleached and deodorized palm oil by using D-optimal design. Water degumming effectively reduced the 3-MCPDE content up to 50%. Acid activated bleaching earth had a greater effect on 3-MCPDE reduction compared to natural bleaching earth and acid activated bleaching earth with neutral pH, indicating that performance and adsorption capacities of bleaching earth are the predominant factors in the removal of esters, rather than its acidity profile. The combination of high dosage phosphoric acid during degumming with the use of acid activated bleaching earth eliminated almost all glycidyl esters during refining. Besides, the effects of crude palm oil quality was assessed and it was found that the quality of crude palm oil determines the level of formation of 3-MCPDE and glycidyl esters in palm oil during the high temperature deodorization step of physical refining process. Poor quality crude palm oil has strong impact towards 3-MCPDE and glycidyl esters formation due to the intrinsic components present within. The findings are useful to palm oil refining industry in choosing raw materials as an input during the refining process.

  14. Self-Assembly, Supramolecular Organization, and Phase Behavior of L-Alanine Alkyl Esters (n = 9-18) and Characterization of Equimolar L-Alanine Lauryl Ester/Lauryl Sulfate Catanionic Complex.

    Science.gov (United States)

    Sivaramakrishna, D; Swamy, Musti J

    2015-09-08

    A homologous series of l-alanine alkyl ester hydrochlorides (AEs) bearing 9-18 C atoms in the alkyl chain have been synthesized and characterized with respect to self-assembly, supramolecular structure, and phase transitions. The CMCs of AEs bearing 11-18 C atoms were found to range between 0.1 and 10 mM. Differential scanning calorimetric (DSC) studies showed that the transition temperatures (Tt), enthalpies (ΔHt) and entropies (ΔSt) of AEs in the dry state exhibit odd-even alternation, with the odd-chain-length compounds having higher Tt values, but the even-chain-length homologues showing higher values of ΔHt and ΔSt. In DSC measurements on hydrated samples, carried out at pH 5.0 and pH 10.0 (where they exist in cationic and neutral forms, respectively), compounds with 13-18 C atoms in the alkyl chain showed sharp gel-to-liquid crystalline phase transitions, and odd-even alternation was not seen in the thermodynamic parameters. The molecular structure, packing properties, and intermolecular interactions of AEs with 9 and 10 C atoms in the alkyl chain were determined by single crystal X-ray diffraction, which showed that the alkyl chains are packed in a tilted interdigitated bilayer format. d-Spacings obtained from powder X-ray diffraction studies exhibited a linear dependence on the alkyl chain length, suggesting that the other AEs also adopt an interdigitated bilayer structure. Turbidimetric, fluorescence spectroscopic, and isothermal titration calorimetric (ITC) studies established that in aqueous dispersions l-alanine lauryl ester hydrochloride (ALE·HCl) and sodium dodecyl sulfate (SDS) form an equimolar complex. Transmission electron microscopic and DSC studies indicate that the complex exists as unilamellar liposomes, which exhibit a sharp phase transition at ∼39 °C. The aggregates were disrupted at high pH, suggesting that the catanionic complex would be useful to develop a base-labile drug delivery system. ITC studies indicated that ALE·HCl forms

  15. Emission of sunscreen salicylic esters from desert vegetation and their contribution to aerosol formation

    Science.gov (United States)

    Matsunaga, S. N.; Guenther, A. B.; Potosnak, M. J.; Apel, E. C.

    2008-12-01

    Biogenic volatile organic compounds (BVOC) produced by plants are known to have an important role in atmospheric chemistry. However, our knowledge of the range of BVOCs produced by different plant processes is still expanding, and there remain poorly understood categories of BVOCs. In this study, emissions of a novel class of BVOC emissions were investigated in a desert region. Our study considered 8 species of common desert plants: blackbrush (Coleogyne ramosissima), desert willow (Chilopsis linearis), mesquite (Prosopis glandulosa), mondel pine (Pinus eldarica), pinyon pine (Pinus monophylla), cottonwood (Populus deltoides), saguaro cactus (Carnegiea gigantea) and yucca (Yucca baccata). The measurements focused on BVOCs with relatively high molecular weight (>C15) and/or an oxygenated functional group. Significantly high emission rates of two salicylic esters were found for blackbrush, desert willow and mesquite with emission rates of 3.1, 1.0 and 4.8μgC dwg-1 h-1, respectively (dwg; dry weight of the leaves in gram). The salicylic esters were identified as 2-ethylhexenyl salicylate (2-EHS) and 3,3,5-trimethylcyclohexenyl salicylate (homosalate) and are known as effective ultraviolet (UV) absorbers. We propose that the plants derive a protective benefit against UV radiation from the salicylic esters and that the emission process is driven by the physical evaporation of the salicylic esters due to the high ambient temperatures. In addition, the salicylic esters are predicted to be an effective precursor of secondary organic aerosol (SOA) because they probably produce oxidation products that can condense onto the aerosol phase. We estimated the contribution of the sunscreen esters themselves and their oxidation products on the SOA formation for the Las Vegas area using a BVOC emission model. The contribution was estimated to reach 50% of the biogenic terpenoid emission in the landscapes dominated by desert willow and mesquite and 13% in the Las Vegas area. The

  16. Formation of monochloropropane-1,2-diol and its esters in biscuits during baking.

    Science.gov (United States)

    Mogol, Burçe Ataç; Pye, Céline; Anderson, Warwick; Crews, Colin; Gökmen, Vural

    2014-07-23

    The formation of free monochloropropane-1,2-diol (3-MCPD and 2-MCPD) and its esters (bound-MCPD) was investigated in biscuits baked with various time and temperature combinations. The effect of salt as a source of chloride on the formation of these processing contaminants was also determined. Kinetic examination of the data indicated that an increasing baking temperature led to an increase in the reaction rate constants for 3-MCPD, 2-MCPD, and bound-MCPD. The activation energies of formation of 3-MCPD and 2-MCPD were found to be 29 kJ mol(-1). Eliminating salt from the recipe decreased 3-MCPD and 2-MCPD formation rate constants in biscuits by 57.5 and 85.4%, respectively. In addition, there was no formation of bound-MCPD in biscuits during baking without salt. Therefore, lowering the thermal load or limiting the chloride concentration should be considered a means of reducing or eliminating the formation of these contaminants in biscuits. Different refined oils were also used in the recipe to test their effect on the occurrence of free MCPD and its esters in biscuits. Besides the baking process, the results also confirmed the role of refined oil in the final concentration of these contaminants in biscuits.

  17. Inhibition of PrPSc formation by synthetic O-sulfated glycopyranosides and their polymers.

    Science.gov (United States)

    Yamaguchi, Satoko; Nishida, Yoshihiro; Sasaki, Kenji; Kambara, Mikie; Kim, Chan-Lan; Ishiguro, Naotaka; Nagatsuka, Takehiro; Uzawa, Hirotaka; Horiuchi, Motohiro

    2006-10-20

    Sulfated glycosaminoglycans (GAGs) and sulfated glycans inhibit formation of the abnormal isoform of prion protein (PrPSc) in prion-infected cells and prolong the incubation time of scrapie-infected animals. Sulfation of GAGs is not tightly regulated and possible sites of sulfation are randomly modified, which complicates elucidation of the fundamental structures of GAGs that mediate the inhibition of PrPSc formation. To address the structure-activity relationship of GAGs in the inhibition of PrPSc formation, we screened the ability of various regioselectively O-sulfated glycopyranosides to inhibit PrPSc formation in prion-infected cells. Among the glycopyranosides and their polymers examined, monomeric 4-sulfo-N-acetyl-glucosamine (4SGN), and two glycopolymers, poly-4SGN and poly-6-sulfo-N-acetyl-glucosamine (poly-6SGN), inhibited PrPSc formation with 50% effective doses below 20 microg/ml, and their inhibitory effect became more evident with consecutive treatments. Structural comparisons suggested that a combination of an N-acetyl group at C-2 and an O-sulfate group at either O-4 or O-6 on glucopyranoside might be involved in the inhibition of PrPSc formation. Furthermore, polymeric but not monomeric 6SGN inhibited PrPSc formation, suggesting the importance of a polyvalent configuration in its effect. These results indicate that the synthetic sulfated glycosides are useful not only for the analysis of structure-activity relationship of GAGs but also for the development of therapeutics for prion diseases.

  18. Sulfate Mineral Formation from Acid-Weathered Phyllosilicates: Implications for the Aqueous History of Mars

    Science.gov (United States)

    Craig, P. I.; Ming, D. W.; Rampe, E. B.; Morris, R. V.

    2015-01-01

    Phyllosilicates on Mars are thought to have formed under neutral to alkaline conditions during Mars' earliest Noachian geologic era (approx. 4.1-3.7 Gya). Sulfate formation, on the other hand, requires more acidic conditions which are thought to have occurred later during Mars' Hesperian era (approx. 3.7-3.0 Gya). Therefore, regions on Mars where phyllosilicates and sulfates are found in close proximity to each other provide evidence for the geologic and aqueous conditions during this global transition. Both phyllosilicates and sulfates form in the presence of water and thus give clues to the aqueous history of Mars and its potential for habitability. Phyllosilicates that formed during the Noachian era may have been weathered by the prevailing acidic conditions that characterize the Hesperian. Therefore, the purpose of this study is to characterize the alteration products resulting from acid-sulfate weathered phyllosilicates in laboratory experiments. This study focuses on two phyllosilicates commonly identified with sulfates on Mars: nontronite and saponite. We also compare our results to observations of phyllosilicates and sulfates on Mars to better understand the formation process of sulfates in close proximity to phyllosilicates on Mars and constrain the aqueous conditions of these regions on Mars.

  19. An exploratory study of alkali sulfate aerosol formation during biomass combustion

    DEFF Research Database (Denmark)

    Løj, Lusi Hindiyarti; Frandsen, Flemming; Livbjerg, Hans

    2008-01-01

    It is still in discussion to what extent alkali sulfate aerosols in biomass combustion are formed in the gas phase by a homogeneous mechanism or involve heterogeneous or catalyzed reactions. The present study investigates sulfate aerosol formation based on calculations with a detailed gas phase...... mechanism. The modeling predictions are compared to data from laboratory experiments and entrained flow reactor experiments available in the literature. The analysis support that alkali sulfate aerosols are formed from homogeneous nucleation following a series of steps occurring in the gas phase. The rate...

  20. Emission of sunscreen salicylic esters from desert vegetation and their contribution to aerosol formation

    Directory of Open Access Journals (Sweden)

    S. N. Matsunaga

    2008-12-01

    Full Text Available Biogenic volatile organic compounds (BVOC produced by plants are known to have an important role in atmospheric chemistry. However, our knowledge of the range of BVOCs produced by different plant processes is still expanding, and there remain poorly understood categories of BVOCs. In this study, emissions of a novel class of BVOC emissions were investigated in a desert region. Our study considered 8 species of common desert plants: blackbrush (Coleogyne ramosissima, desert willow (Chilopsis linearis, mesquite (Prosopis glandulosa, mondel pine (Pinus eldarica, pinyon pine (Pinus monophylla, cottonwood (Populus deltoides, saguaro cactus (Carnegiea gigantea and yucca (Yucca baccata. The measurements focused on BVOCs with relatively high molecular weight (>C15 and/or an oxygenated functional group. Significantly high emission rates of two salicylic esters were found for blackbrush, desert willow and mesquite with emission rates of 3.1, 1.0 and 4.8μgC dwg−1 h−1, respectively (dwg; dry weight of the leaves in gram. The salicylic esters were identified as 2-ethylhexenyl salicylate (2-EHS and 3,3,5-trimethylcyclohexenyl salicylate (homosalate and are known as effective ultraviolet (UV absorbers. We propose that the plants derive a protective benefit against UV radiation from the salicylic esters and that the emission process is driven by the physical evaporation of the salicylic esters due to the high ambient temperatures. In addition, the salicylic esters are predicted to be an effective precursor of secondary organic aerosol (SOA because they probably produce oxidation products that can condense onto the aerosol phase. We estimated the contribution of the sunscreen esters themselves and their oxidation products on the SOA formation for the Las Vegas area using a BVOC emission model. The contribution was estimated to reach 50% of the biogenic terpenoid

  1. High rate sulfate reduction at pH 6 in a Ph-auxostat submerged membrane bioreactor fed with formate

    NARCIS (Netherlands)

    Bijmans, M.F.M.; Peeters, T.W.T.; Lens, P.N.L.; Buisman, C.J.N.

    2008-01-01

    Many industrial waste and process waters contain high concentrations of sulfate, which can be removed by sulfate-reducing bacteria (SRB). This paper reports on mesophilic (30 °C) sulfate reduction at pH 6 with formate as electron donor in a membrane bioreactor with a pH-auxostat dosing system. A

  2. Reaction between drug substances and pharmaceutical excipients: formation of esters between cetirizine and polyols.

    Science.gov (United States)

    Yu, He; Cornett, Claus; Larsen, Jesper; Hansen, Steen Honoré

    2010-11-02

    Reactions between active drug substances and excipients are of interest in the drug formulation process and should also be considered in the following storage of final preparations. Some excipients react more readily with certain chemical groups in drug substances and in the present paper the ester formation between a drug substance having a carboxylic acid moiety and some polyols are described. The drug substance cetirizine was chosen as the model substance as it is already marketed and used as a common drug for treatment of allergic reactions. Among the marketed products are oral solutions and oral drops containing excipients like sorbitol and glycerol. It was found that the carboxylic acid cetirizine readily reacts with sorbitol and glycerol to form monoesters. At a temperature as low as 40 degrees C, more than 1% of the cetirizine content was transformed into a monoester within 1 week using concentrations similar to those used in marketed preparations. The kinetic studies of the reaction performed at 40, 60 and 80 degrees C also revealed that the esters were unstable and they degraded especially at higher temperatures. Analysis of two marketed preparations having expiry dates in 2011 showed content of the cetirizine esters corresponding to a range from 0.1 to 0.3% of the declared cetirizine content. Copyright (c) 2010 Elsevier B.V. All rights reserved.

  3. Sulfate Formation From Acid-Weathered Phylosilicates: Implications for the Aqueous History of Mars

    Science.gov (United States)

    Craig, P. I.; Ming, D. W.; Rampe, E. B.

    2014-01-01

    Most phyllosilicates on Mars are thought to have formed during the planet's earliest Noachian era, then Mars underwent a global change making the planet's surface more acidic [e.g. 1]. Prevailing acidic conditions may have affected the already existing phyllosilicates, resulting in the formation of sulfates. Both sulfates and phyllosilicates have been identified on Mars in a variety of geologic settings [2] but only in a handful of sites are these minerals found in close spatial proximity to each other, including Mawrth Vallis [3,4] and Gale Crater [5]. While sulfate formation from the acidic weathering of basalts is well documented in the literature [6,7], few experimental studies investigate sulfate formation from acid-weathered phyllosilicates [8-10]. The purpose of this study is to characterize the al-teration products of acid-weathered phyllosilicates in laboratory experiments. We focus on three commonly identified phyllosilicates on Mars: nontronite (Fe-smectite), saponite (Mg-smectite), and montmorillonite (Al-smectite) [1, and references therein]. This information will help constrain the formation processes of sulfates observed in close association with phyllosilicates on Mars and provide a better understanding of the aqueous history of such regions as well as the planet as a whole.

  4. The influence of sodium salts (iodide, chloride and sulfate) on the formation efficiency of sulfamerazine nanocrystals.

    Science.gov (United States)

    Lou, Hao; Liu, Min; Qu, Wen; Johnson, James; Brunson, Ed; Almoazen, Hassan

    2014-08-01

    The purpose of this study is to evaluate the influence of sodium iodide, sodium chloride and sodium sulfate on the formation efficiency of sulfamerazine nanocrystals by wet ball milling. Sulfamerazine was milled using zirconium oxide beads in a solution containing polyvinylpyrrolidone (PVP) and a sodium salt (iodide, chloride or sulfate). Particle size distributions were evaluated by light diffraction before and after milling. High-performance liquid chromatography was utilized to determine the amount of PVP adsorbed onto sulfamerazine surface. Lyophilized nanocrystals were further characterized by differential scanning calorimetry and dissolution testing. Sulfate ion had more profound effect on reducing particle size via milling than iodide or chloride. We linked our findings to Hofmeister ion series, which indicates that sulfate ions tends to break the water structure, increases the surface tension and lowers the solubility of hydrocarbons in water. We hypothesized that the addition of sulfate ions dehydrated the PVP molecules and enhanced its adsorption onto the sulfamerazine particle surfaces. Consequently, the adsorbed PVP helped to stabilize of the nanosuspension. The nanocrystals that were obtained from the lyophilized milled suspensions exhibited a notable increase in dissolution rate. The addition of sodium sulfate enhanced the formation efficiency of sulfamerazine nanocrystals.

  5. Streptomyces lunalinharesii 235 prevents the formation of a sulfate-reducing bacterial biofilm

    Directory of Open Access Journals (Sweden)

    Juliana Pacheco da Rosa

    Full Text Available ABSTRACT Streptomyces lunalinharesii strain 235 produces an antimicrobial substance that is active against sulfate reducing bacteria, the major bacterial group responsible for biofilm formation and biocorrosion in petroleum reservoirs. The use of this antimicrobial substance for sulfate reducing bacteria control is therefore a promising alternative to chemical biocides. In this study the antimicrobial substance did not interfere with the biofilm stability, but the sulfate reducing bacteria biofilm formation was six-fold smaller in carbon steel coupons treated with the antimicrobial substance when compared to the untreated control. A reduction in the most probable number counts of planktonic cells of sulfate reducing bacteria was observed after treatments with the sub-minimal inhibitory concentration, minimal inhibitory concentration, and supra-minimal inhibitory concentration of the antimicrobial substance. Additionally, when the treated coupons were analyzed by scanning electron microscopy, the biofilm formation was found to be substantially reduced when the supra-minimal inhibitory concentration of the antimicrobial substance was used. The coupons used for the biofilm formation had a small weight loss after antimicrobial substance treatment, but corrosion damage was not observed by scanning electron microscopy. The absence of the dsrA gene fragment in the scraped cell suspension after treatment with the supra-minimal inhibitory concentration of the antimicrobial substance suggests that Desulfovibrio alaskensis was not able to adhere to the coupons. This is the first report on an antimicrobial substance produced by Streptomyces active against sulfate reducing bacteria biofilm formation. The application of antimicrobial substance as a potential biocide for sulfate reducing bacteria growth control could be of great interest to the petroleum industry.

  6. Effect of caffeic acid phenethyl ester on bone formation in the expanded inter-premaxillary suture

    Directory of Open Access Journals (Sweden)

    Kazancioglu HO

    2015-12-01

    Full Text Available Hakki Oguz Kazancioglu,1 Sertac Aksakalli,2 Seref Ezirganli,1 Muhammet Birlik,2 Mukaddes Esrefoglu,3 Ahmet Hüseyin Acar1 1Department of Oral and Maxillofacial Surgery, 2Department of Orthodontics, Faculty of Dentistry, 3Department of Histology, Faculty of Medicine, Bezmialem Vakif University, Istanbul, Turkey Background: Narrow maxilla is a common problem in orthodontics and dentofacial orthopedics. To solve this problem, a procedure called rapid maxillary expansion (RME has been used. However, relapse tendency is a major problem of RME. Although relapse tendency is not clearly understood, various treatment procedures and new application has been investigated. The present study aimed to investigate the possible effectiveness of caffeic acid phenethyl ester (CAPE on new bone formation in rat midpalatal suture after RME.Materials and methods: Twenty male Sprague Dawley rats were used in this study. The animals were randomly divided into two groups as control and CAPE group. In CAPE group, CAPE was administered systemically via intraperitoneal injection. RME procedure was performed on all animals. For this purpose, the springs were placed on the maxillary incisors of rats and activated for 5 days. After then, the springs were removed and replaced with short lengths of rectangular retaining wire for consolidation period of 15 days. At the end of the study, histomorphometric analysis was carried out to assess of new bone formation.Results: New bone formation was significantly greater in CAPE group than the control group (P<0.05. CAPE enhances new bone formation in midpalatal suture after RME.Conclusion: These results show that CAPE may decrease the time needed for retention. Keywords: rapid maxillary expansion, bone formation, caffeic acid phenethyl ester, midpalatal suture, histopathology

  7. Synthesis of Furandicarboxylic Acid Esters From Nonfood Feedstocks Without Concomitant Levulinic Acid Formation.

    Science.gov (United States)

    van der Klis, Frits; van Haveren, Jacco; van Es, Daan S; Bitter, Johannes H

    2017-04-10

    5-Hydroxymethylfurfural (HMF) is a versatile intermediate in biomass conversion pathways. However, the notoriously unstable nature of HMF imposes challenges to design selective routes to chemicals such as furan-2,5-dicarboxylic acid (FDCA). Here, a new strategy for obtaining furans is presented, bypassing the formation of the unstable HMF. Instead of starting with glucose/fructose and thus forming HMF as an intermediate, the new route starts from uronic acids, which are abundantly present in many agro residues such as sugar beet pulp, potato pulp, and citrus peels. Conversion of uronic acids, via ketoaldonic acids, to the intermediate formylfuroic acid (FFA) esters, and subsequently to FDCA esters, proceeds without formation of levulinic acid or insoluble humins. This new route provides an attractive strategy to valorize agricultural waste streams and a route to furanic building blocks without the co-production of levulinic acid or humins. © 2015 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  8. Formation of Authigenic Sulfates in Cold Dry Glaciers: Terrestrial and Planetary Implications of Sublimites

    Science.gov (United States)

    Massé, M.; Rondeau, B.; Ginot, P.; Schmitt, B.; Bourgeois, O.; Mitri, G.

    2015-12-01

    Salts are common on planetary surfaces, and sulfates have been widely observed on Earth, Mars (Gendrin et al., 2005) and on some of Jupiter's and Saturn's icy moons like Europa (Dalton et al., 2007). These minerals can form under a wide range of conditions, and the determination of sulfate formation processes can provide key elements for deciphering past planetary surface conditions. Most terrestrial sulfates form as evaporites in warm environments with high water/rock ratios, but these conditions are rarely encountered on other planets. Here we describe the formation of cryogenic sulfates in an extreme cold and dry environment: the Guanaco glacier located in the Chilean Andes (Fig.1a, Rabatel et al., 2011). Field analyses reveal that it is a cold-based glacier, its surface temperature remains below 0°C throughout the year, and ablation occurs mostly by sublimation. Ablation creates ice cliffs punctuated of pluricentimetric whitish, tapered crystals embedded in the ice (Fig.1b, c). By Raman and chemistry, they proved to be gypsum, covered by micrometric crystals of jarosite, halotrichite and native sulfur. The euhedral morphology of these soft minerals indicates that they are neoformed and have not been transported in the ice. This is supported by the absence of gypsum crystals in ice cores drilled through the glacier. We infer that the crystallization thus occurred at the glacier surface during ice sublimation and does not involve liquid water. To distinguish this original salt formation process from the more common evaporites, we name these minerals "sublimites". Though this formation process is uncommon and generates minor quantities of sulfates on Earth, it may be dominant on other bodies in the Solar System where sublimation is effective. Examples of planetary sublimites may include gypsum on the North Polar Cap of Mars (Massé et al., 2012), and other sulfates on icy moons where sublimation has been observed (Howard et al., 2008).

  9. Investigation of sulfate and nitrate formation on mineral dust particles by receptor modeling

    Energy Technology Data Exchange (ETDEWEB)

    Hien, P.D.; Bac, V.T.; Thinh, N.T.H. [Vietnam Atomic Energy Commission, Hanoi (Vietnam)

    2005-12-01

    The formation of sulfate and nitrate by heterogeneous reactions of gaseous precursors on mineral dust particles was investigated using positive matrix factorization (PMF) of coarse PM10 (particulate diameters from 2.2 to 10 {mu} m) collected at urban (Hanoi) and rural (Lucnam) sites in northern Vietnam. Air samples were analyzed for ionic and elemental components using ion chromatography and proton induced X-ray emission methods. PMF revealed six similar sources/types of coarse PM10 at the two sites, namely soil dust containing nitrate and sulfate, coal fly ash from distant and local sources, soil dust containing organic matter and ammonium sulfate and marine aerosol. Traffic (road) dust was found only at the urban site. From the PMF factor models, the yields of NO{sub 3}{sup -}, SO{sub 4}{sup 2-} and NH{sub 4}{sup +} can be estimated and their possible chemical forms in different particulate types can be suggested. The yields of nitrate and sulfate formation on mineral dust particles increase with the (Ca)/(Si) ratio, which is greater in soil dust than in coal fly ash. Nitrate is bound to Ca-richest soil dust particles. Ammonium was found in dust particles containing soil organic matter, which also hold the largest amount of sulfate. The comparison of urban and rural receptor models provided synergy for the source identification and insights into the properties of mineral dust particles relevant to their interactions with acidic gases in ambient air.

  10. Klebsiella pneumoniae KE-1 degrades endosulfan without formation of the toxic metabolite, endosulfan sulfate.

    Science.gov (United States)

    Kwon, Gi-Seok; Kim, Jang-Eok; Kim, Taek-Kyum; Sohn, Ho-Yong; Koh, Sung-Cheol; Shin, Kee-Sun; Kim, Dong-Geol

    2002-10-08

    For bioremediation of toxic endosulfan, endosulfan degradation bacteria, which do not form toxic endosulfan sulfate, were isolated from various soil samples using endosulfan as sole carbon and energy source. Among the 40 isolated bacteria, strain KE-1, which was identified as Klebsiella pneumoniae by physiological and 16S rDNA sequence analysis, showed superior endosulfan degradation activity. Analysis of culture pH, growth, free sulfate and endosulfan and its metabolites demonstrated that KE-1 biologically degrades 8.72 microg endosulfan ml(-1) day(-1) when incubated with 93.9 microg ml(-1) endosulfan for 10 days without formation of toxic endosulfan sulfate. Our results suggest that K. pneumoniae KE-1 degraded endosulfan by a non-oxidative pathway and that strain KE-1 has potential as a biocatalyst for endosulfan bioremediation.

  11. [Inhibition of chlorobenzene formation via various routes during waste incineration by ammonium sulfate and urea].

    Science.gov (United States)

    Yan, Mi; Qi, Zhi-Fu; Li, Xiao-Dong; Hu, Yan-Jun; Chen, Tong

    2014-01-01

    Chlorobenzene (CBz) is the precursor of polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans (PCDD/Fs) generated in the processes of waste incineration, and it is regarded as a good indicator of PCDD/Fs for realizing PCDD/Fs online monitoring, moreover, pentachlorobenzene (PeCBz) and Hexachlorobenzene (HxCBz) belong to Persistent Organic Pollutants (POPs). However, the emission control of CBz in waste incineration does not attract enough attention, so this study focused on the inhibition of the 3 CBz formation routes in waste combustion by ammonium sulfate and urea, including CB formation from fly ash, CB formation from 1,2-dichlorobenzene (1,2-DiCBz) and the combustion of model medical waste. The results showed that both ammonium sulfate and urea reduced CBz yield during these three thermal processes. For instance, the inhibition rates of tetrachlorobenzene (TeCBz), PeCBz and HxCBz were 66.8%, 57.4% and 50.4%, respectively, when 1% urea was co-combusted with medical waste. By comparing the effect of ammonium sulfate and urea on CBz formation by three routes, urea was considered as a comparatively stable inhibitor for CBz.

  12. Fate of Tetrabromobisphenol A (TBBPA) and Formation of Ester- and Ether-Linked Bound Residues in an Oxic Sandy Soil.

    Science.gov (United States)

    Li, Fangjie; Wang, Jiajia; Jiang, Bingqi; Yang, Xue; Nastold, Peter; Kolvenbach, Boris; Wang, Lianhong; Ma, Yini; Corvini, Philippe François-Xavier; Ji, Rong

    2015-11-03

    Bound-residue formation is a major dissipation process of most organic xenobiotics in soil. However, both the formation and nature of bound residues of tetrabromobisphenol A (TBBPA) in soil are unclear. Using a 14C-tracer, we studied the fate of TBBPA in an oxic soil during 143 days of incubation. TBBPA dissipated with a half-life of 14.7 days; at the end of incubation, 19.6% mineralized and 66.5% formed bound residues. Eight extractable metabolites were detected, including TBBPA methyl ethers, single-ring bromophenols, and their methyl ethers. Bound residues (mostly bound to humin) rapidly formed during the first 35 days. The amount of those humin-bound residues then quickly decreased, whereas total bound residues decreased slowly. By contrast, residues bound to humic acids and fulvic acids increased continuously until a plateau was reached. Ester- and ether-linked residues accounted for 9.6-27.0% of total bound residues during the incubation, with ester linkages being predominant. Residues bound via ester linkages consisted of TBBPA, TBBPA monomethyl ether, and an unknown polar compound. Our results indicated that bound-residue formation is the major pathway of TBBPA dissipation in oxic soil and provide first insights into the chemical structure of the reversibly ester-linked bound residues of TBBPA and its metabolites.

  13. Rational selection of non-Saccharomyces wine yeasts for mixed starters based on ester formation and enological traits.

    Science.gov (United States)

    Viana, Fernando; Gil, José V; Genovés, Salvador; Vallés, Salvador; Manzanares, Paloma

    2008-09-01

    Thirty-eight yeast strains belonging to the genera Candida, Hanseniaspora, Pichia, Torulaspora and Zygosaccharomyces were screened for ester formation on synthetic microbiological medium. The genera Hanseniaspora and Pichia stood out as the best acetate ester producers. Based on the ester profile Hanseniaspora guilliermondii 11027 and 11102, Hanseniaspora osmophila 1471 and Pichia membranifaciens 10113 and 10550 were selected for further characterization of enological traits. When growing on must H. osmophila 1471, which displayed a glucophilic nature and was able to consume more than 90% of initial must sugars, produced levels of acetic acid, medium chain fatty acids and ethyl acetate, within the ranges described for wine. On the other hand, it was found to be a strong producer of 2-phenylethyl acetate. Our data suggest that H. osmophila 1471 is a good candidate for mixed starters, although the possible interactions with S. cerevisiae deserve further research.

  14. Theoretical prediction of condensed phase heat of formation of nitramines, nitrate esters, nitroaliphatics and related energetic compounds.

    Science.gov (United States)

    Keshavarz, Mohammad Hossein

    2006-08-21

    An empirical approach is presented for calculation heats of formation of nitramines, nitrate esters, nitroaliphatics and related energetic compounds which contain at least one of the functional groups including N-NO(2), C-ONO(2) or nonaromatic C-NO(2). This approach is based on elemental composition and various structural and functional group parameters of C(a)H(b)N(c)O(d) energetic compounds. Heat of formation for 78 nitrocompounds including nitramines, nitrate esters, nitroaliphatics and the data obtained is compared with experimental data. Root mean square (rms) of deviation for 19 well known of mentioned energetic compounds are also compared with complex quantum mechanical computations which show 23.8 and 21.3 kJ/mol for new and quantum mechanical methods, respectively. Predicted condensed phase heats of formation for remainder 59 energetic molecules with complex molecular structures have a rms deviation from experiment of 42.3 kJ/mol.

  15. Formation of polyol-fatty acid esters by lipases in reverse micellar media.

    Science.gov (United States)

    Hayes, D G; Gulari, E

    1992-06-05

    The synthesis of polyol-fatty acid esters has strong implications in such industries as foods, cosmetics, and polymers. We have investigated these esterification reactions employing the polyols ethylene glycol, 2-monoglyceride, and sugars and their derivatives with the biocatalyst lipase in water/AOT/isooctane reverse micellar media. For the first reaction, 50-60% conversion was achieved and product selectivity toward the monoester over the diester shown possible by employing lipase from Rhizopus delemar. A simple kinetic model based on the formation of acyl-enzyme intermediate accurately predicted the effect of polyol concentration but not the effect of fatty acid or water concentration probably due to the model exclusion of partitioning effects. The success of this reaction in reverse micellar media is due greatly to its capacity to solubilize large quantities of glycol despite the media's overall hydrophobicity. The second reaction, investigated for its potential for production of "mixed" glycerides, also achieved about 50% conversion but had only a small portion of triglyceride in its product distribution. Also, isomerization of the 2-monoglyceride to 1-monoglyceride, followed by hydrolysis of the latter, unfortunately occurred to a significant extent. Attempts at esterification with hexoses and their derivatives such as glucose and mannitol produced no conversion.

  16. Effects of Fe3+and Antioxidants on Glycidyl Ester Formation in Plant Oil at High Temperature and Their Influencing Mechanisms.

    Science.gov (United States)

    Cheng, Weiwei; Liu, Guoqin; Liu, Xinqi

    2017-05-24

    This research investigated the effects of Fe 3+ and antioxidants on the formation of glycidyl esters (GEs) and the free radical mediated mechanisms involving the recognition of cyclic acyloxonium free radical intermediate (CAFRI) for GE formation in both the plant oil model (palm oil, camellia oil, soybean oil, and linseed oil) system and the chemical model (dipalmitin and methyl linoleate) system heated at 200 °C. Results show that Fe 3+ can promote the formation of GEs, which can be inhibited by antioxidants in plant oil during high-temperature exposure. Based on the monitoring of cyclic acyloxonium and ester carbonyl group by Fourier transform infrared spectroscopy, the promotion of Fe 3+ and the inhibition of antioxidants (tert-butylhydroquinone and α-tocopherol) for GE formation occurred not only through lipid oxidation but also through directly affecting the formation of cyclic acyloxonium intermediate. Additionally, a quadrupole time-of-flight tandem mass spectrometry measurement was conducted to identify the presence of radical adduct captured by 5,5-dimethylpyrroline N-oxide, which provided strong evidence for the formation of CAFRI. Thus, one possible influencing mechanism can be that free radical generated in lipid oxidation may be transferred to dipalmitin and promote CAFRI formation. Fe 3+ can catalyze free radical generation while antioxidants can scavenge free radical, and therefore they also can directly affect CAFRI formation.

  17. Investigation of organic desulfurization additives affecting the calcium sulfate crystals formation

    Directory of Open Access Journals (Sweden)

    Lv Lina

    2017-01-01

    Full Text Available In the study, the optimal experimental conditions for gypsum crystals formation were 323 K, 300 rpm stirring speed. The major impurities of Mg2+, Al3+ and Fe3+ were found to inhibit calcium sulfate crystals formation. Fe3+ caused the strongest inhibition, followed by Mg2+ and Al3+. The influence of desulfurization additives on the gypsum crystals formation was explored with the properties of moisture content, particle size distribution and crystal morphology. The organic desulfurization additives of adipic acid, citric acid, sodium citrate and benzoic acid were investigated. Citric acid and sodium citrate were found to improve the quality of gypsum. Moisture contents were reduced by more than 50%, gypsum particle sizes were respectively enlarged by 9.1 and 22.8%, induction time extended from 4.3 (blank to 5.3 and 7.8 min, and crystal morphology trended to be thicker.

  18. Fluids During Diagenesis and Sulfate Vein Formation in Sediments at Gale Crater, Mars

    Science.gov (United States)

    Schwenzer, S. P.; Bridges, J. C.; Weins, R. C.; Conrad, P. G.; Kelley, S. P.; Leveille, R.; Mangold, N.; Martin-Torres, J.; McAdam, A.; Newsom, H.; hide

    2016-01-01

    We model the fluids involved in the alteration processes recorded in the Sheep bed Member mudstones of Yellowknife Bay (YKB), Gale crater, Mars, as revealed by the Mars Science Laboratory Curiosity rover investigations. We compare the Gale crater waters with fluids modeled for shergottites, nakhlites, and the ancient meteorite ALH 84001, as well as rocks analyzed by the Mars Exploration rovers, and with terrestrial ground and surface waters. The aqueous solution present during sediment alteration associated with phyllosilicate formation at Gale was high in Na, K, and Si; had low Mg, Fe, and Al concentrations relative to terrestrial ground waters such as the Deccan Traps and other modeled Mars fluids; and had near neutral to alkaline pH. Ca and S species were present in the 10(exp -3) to 10(exp -2) concentration range. A fluid local to Gale crater strata produced the alteration products observed by Curiosity and subsequent evaporation of this ground water- type fluid formed impure sulfate- and silica-rich deposits veins or horizons. In a second, separate stage of alteration, partial dissolution of this sulfate-rich layer in Yellowknife Bay,or beyond, led to the pure sulfate veins observed in YKB. This scenario is analogous to similar processes identified at a terrestrial site in Triassic sediments with gypsum veins of the Mercia Mudstone Group in Watchet Bay, UK.

  19. Nucleation kinetics of the formation of low dimensional calcium sulfate dihydrate crystals in isopropyl alcohol medium

    Energy Technology Data Exchange (ETDEWEB)

    Sandhya, S.; Sureshbabu, S.; Varma, H.K.; Komath, Manoj [Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum 695 012 (India)

    2012-07-15

    Calcium sulfate dihydrate, constituted as uniform crystals of low dimensions, is a potential biomaterial for clinical applications like bone graft substitution and drug delivery. In this work, isopropyl alcohol has been used as a solvent to obtain low dimensional calcium sulfate dihydrate crystals from calcium nitrate - sulfuric acid system. Reactants in 0.5 molar concentration at ambient conditions generated uniform rod-shaped crystals of length 3-5 {mu}m. Analysis using X-ray Diffractometry and Fourier Transform Infrared Spectrometry showed the material to be well crystallized, phase-pure calcium sulfate dihydrate. The nucleation kinetics has been studied by observing the induction time of phase formation in solutions of millimolar concentrations through turbidimetry at 300 K. The data have been analysed using classical nucleation theory to deduce parameters like interfacial tension (or surface free energy), nucleation rate and critical radius. The surface free energy obtained (5.6 mJ/m{sup 2}) is comparatively lower than that reported for aqueous precipitation, which could be attributed to the presence of isopropyl alcohol. On escalating the supersaturation ratio, the nucleation rate drastically increased and the critical radius decreased exponentially. Particles formed at supersaturation 1.39 showed a monomodal distribution centered at 8.2 nm in Dynamic Light Scattering analysis. Comparable particle sizes were obtained in Transmission Electron Microscopy. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. Similarities Across Mars: Acidic Fluids at Both Meridiani Planum and Gale Crater in the Formation of Magnesium-Nickel Sulfates

    Science.gov (United States)

    Yen, Albert S.; Ming, Douglas W.; Gellert, Ralf; Mittlefehldt, David W.; Vaniman, David T.; Thompson, Lucy M.; Morris, Richard V.; Clark, Benton C.; Arvidson, Raymond

    2016-01-01

    In-situ identification of sulfates at the martian surface by the Mars Exploration Rovers and the Mars Science Laboratory have included calcium sulfates with various states of hydration (gypsum, bassanite, anhydrite), iron sulfates of likely fumarolic origin, massive deposits of iron hydroxysulfates indicative of an acidic history, and minor occurrences of magnesium sulfates. Recent measurements by the Opportunity and Curiosity Alpha Particle X-ray Spectrometers (APXS) have indicated the presence of Ni-substituted Mg-sulfates at the Meridiani Planum and Gale Crater landing sites. The Opportunity rover has traversed nearly 43 km and is currently exploring the impact breccias of the rim of Endeavour crater, near a location where signatures of aqueous alteration have been established from orbit. APXS analyses of subsurface materials excavated by a rover wheel show clear evidence for a Mg(Ni)-sulfate with Mg:Ni (is) approximately 100:1 (molar). On the other side of the planet, Curiosity is continuing its climb up Mount Sharp after driving (is) approximately 13 km since landing. Over the last 4 km of the traverse, there have been multiple chemical analyses of erosionally-resistant nodules and dendritic features in a finely laminated mudstone unit which also indicate Mg(Ni)-sulfate (Mg:Ni (is) approximately 30:1, molar). The geologic settings for the Endeavour rim and the Mount Sharp mudstones are clearly different, but similar formation conditions for these sulfates may be possible. Ni(2+) readily substitutes for Mg(2+) in a variety of geochemical processes due to their comparable ionic radii. The availability of soluble Ni at the time of Mg-sulfate precipitation suggests acidic solutions. The fluids responsible for alteration in the Endeavour rim and for the formation of nodules in Gale mudstones may have had similar chemical characteristics at the time the Mg-sulfates were formed.

  1. Dual roles of borax in kinetics of calcium sulfate dihydrate formation.

    Science.gov (United States)

    Jiang, Wenge; Pan, Haihua; Tao, Jinhui; Xu, Xurong; Tang, Ruikang

    2007-04-24

    An additive is not exclusively retardant or promoter for a crystallization system. The kinetic studies of calcium sulfate dihydrate (CSD) crystal growth demonstrated that borax played dual roles in the reaction, which accelerated CSD formations at the low concentration levels but inhibited the crystal growth at the high ones. In situ atomic force microscopy studies revealed that borax modulated the CSD crystallization via two different pathways: promoted the secondary nucleation to increase the step density on the growing crystal faces but simultaneously retarded the spread of these growth steps by the Langmuir adsorption. These two contradictory factors were incorporated in the crystallization, and their balance was regulated by the borax concentration. Both the macroscopic and microscopic experimental data nicely displayed the crystallization model of birth and spread that was able to account for the behaviors of borax in CSD formations.

  2. On the chemical ladder of esters. Detection and formation of ethyl formate in the W51 e2 hot molecular core

    Science.gov (United States)

    Rivilla, V. M.; Beltrán, M. T.; Martín-Pintado, J.; Fontani, F.; Caselli, P.; Cesaroni, R.

    2017-03-01

    Context. In recent years, the detection of organic molecules with increasing complexity and potential biological relevance is opening the possibility to understand the formation of the building blocks of life in the interstellar medium. One of the families of molecules of substantial astrobiological interest are the esters. The simplest ester, methyl formate (CH3OCHO), is rather abundant in star-forming regions. The next step in the chemical complexity of esters is ethyl formate, C2H5OCHO. Despite the increase in sensitivity of current telescopes, the detection of complex molecules with more than ten atoms such as C2H5OCHO is still a challenge. Only two detections of this species have been reported so far, which strongly limits our understanding of how complex molecules are formed in the interstellar medium. New detections towards additional sources with a wide range of physical conditions are crucial to differentiate between competing chemical models based on dust grain surface and gas-phase chemistry. Aims: We have searched for ethyl formate towards the W51 e2 hot molecular core, one of the most chemically rich sources in the Galaxy and one of the most promising regions to study prebiotic chemistry, especially after the recent discovery of the P-O bond, key in the formation of DNA. Methods: We have analyzed a spectral line survey towards the W51 e2 hot molecular core, which covers 44 GHz in the 1, 2 and 3 mm bands, carried out with the IRAM 30 m telescope. Results: We report the detection of the trans and gauche conformers of ethyl formate. A local thermodynamic equilibrium analysis indicates that the excitation temperature is 78 ± 10 K and that the two conformers have similar source-averaged column densities of (2.0 ± 0.3) × 10-16 cm-2 and an abundance of 10-8. We compare for the first time the observed molecular abundances of ethyl formate with different competing chemical models based on grain surface and gas-phase chemistry. Conclusions: We propose that

  3. Thermodynamic Aspects of the Formation of Sulfate Minerals from Hot Gaseous Phase

    Science.gov (United States)

    Giere, R.; Majzlan, J.

    2006-12-01

    Minerals may form by solid-state reactions or by dissolution and precipitation from a fluid phase, be it magma, aqueous medium, or gas. The latter phase was traditionally not considered as important as the other ones, although it may be essential in some geological environments. Components of minerals (e.g., sulfur) are commonly transported by hot gases in volcanoes. Others may form in burning coal dumps or by burning fossil fuels for energy production. We have identified a number of minerals which precipitated from the hot gases escaping into the atmosphere from the smoke stack of a coal-fired power plant. This power plant uses coal or a mixture of coal and used tires to produce electricity. The phases identified by TEM are anglesite (PbSO4), gunningite (ZnSO4?H2O), anhydrite (CaSO4), and yavapaiite (KFe(SO4)2). In addition to these crystalline phases, amorphous sulfate materials and soot have been identified. All these materials were captured by filtering the escaping gases beyond the last filters intended to remove any particles from the gas stream. Therefore, they must have formed by precipitation from the hot gas and may present a significant pollution load in the vicinity of power plants. Verhulst et al. (1996) have shown that several metals are most likely transported as chloride complexes in the gas phase. Their assumption correlates well with the finding that the chloride-richer coal+tire mixture increases considerably amounts of emitted metals. Using thermodynamic data for these and other sulfate minerals, we are trying to understand and model the precipitation process of these minerals from hot gases at ambient pressures. In this contribution, we focus on the mineral mikasaite (trigonal Fe2(SO4)3). This mineral has been reported only from burning coal dumps (Miura et al. 1994). Using acid-solution calorimetry, we have determined the enthalpy of formation of mikasaite from elements at T = 298.15 K. We have further estimated the standard entropy of this

  4. Ester-Mediated Amide Bond Formation Driven by Wet-Dry Cycles: A Possible Path to Polypeptides on the Prebiotic Earth.

    Science.gov (United States)

    Forsythe, Jay G; Yu, Sheng-Sheng; Mamajanov, Irena; Grover, Martha A; Krishnamurthy, Ramanarayanan; Fernández, Facundo M; Hud, Nicholas V

    2015-08-17

    Although it is generally accepted that amino acids were present on the prebiotic Earth, the mechanism by which α-amino acids were condensed into polypeptides before the emergence of enzymes remains unsolved. Here, we demonstrate a prebiotically plausible mechanism for peptide (amide) bond formation that is enabled by α-hydroxy acids, which were likely present along with amino acids on the early Earth. Together, α-hydroxy acids and α-amino acids form depsipeptides-oligomers with a combination of ester and amide linkages-in model prebiotic reactions that are driven by wet-cool/dry-hot cycles. Through a combination of ester-amide bond exchange and ester bond hydrolysis, depsipeptides are enriched with amino acids over time. These results support a long-standing hypothesis that peptides might have arisen from ester-based precursors. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Brown carbon formation by aqueous-phase carbonyl compound reactions with amines and ammonium sulfate.

    Science.gov (United States)

    Powelson, Michelle H; Espelien, Brenna M; Hawkins, Lelia N; Galloway, Melissa M; De Haan, David O

    2014-01-21

    Reactions between small water-soluble carbonyl compounds, ammonium sulfate (AS), and/or amines were evaluated for their ability to form light-absorbing species in aqueous aerosol. Aerosol chemistry was simulated with bulk phase reactions at pH 4, 275 K, initial concentrations of 0.05 to 0.25 M, and UV-vis and fluorescence spectroscopy monitoring. Glycolaldehyde-glycine mixtures produced the most intense absorbance. In carbonyl compound reactions with AS, methylamine, or AS/glycine mixtures, product absorbance followed the order methylglyoxal > glyoxal > glycolaldehyde > hydroxyacetone. Absorbance extended into the visible, with a wavelength dependence fit by absorption Ångstrom coefficients (Å(abs)) of 2 to 11, overlapping the Å(abs) range of atmospheric, water-soluble brown carbon. Many reaction products absorbing between 300 and 400 nm were strongly fluorescent. On a per mole basis, amines are much more effective than AS at producing brown carbon. In addition, methylglyoxal and glyoxal produced more light-absorbing products in reactions with a 5:1 AS-glycine mixture than with AS or glycine alone, illustrating the importance of both organic and inorganic nitrogen in brown carbon formation. Through comparison to biomass burning aerosol, we place an upper limit on the contribution of these aqueous carbonyl-AS-amine reactions of ≤ 10% of global light absorption by brown carbon.

  6. Secondary organic aerosol formation during evaporation of droplets containing atmospheric aldehydes, amines, and ammonium sulfate.

    Science.gov (United States)

    Galloway, Melissa M; Powelson, Michelle H; Sedehi, Nahzaneen; Wood, Stephanie E; Millage, Katherine D; Kononenko, Julia A; Rynaski, Alec D; De Haan, David O

    2014-12-16

    Reactions of carbonyl compounds in cloudwater produce organic aerosol mass through in-cloud oxidation and during postcloud evaporation. In this work, postcloud evaporation was simulated in laboratory experiments on evaporating droplets that contain mixtures of common atmospheric aldehydes with ammonium sulfate (AS), methylamine, or glycine. Aerosol diameters were measured during monodisperse droplet drying experiments and during polydisperse droplet equilibration experiments at 75% relative humidity, and condensed-phase mass was measured in bulk thermogravimetric experiments. The evaporation of water from a droplet was found to trigger aldehyde reactions that increased residual particle volumes by a similar extent in room-temperature experiments, regardless of whether AS, methylamine, or glycine was present. The production of organic aerosol volume was highest from droplets containing glyoxal, followed by similar production from methylglyoxal or hydroxyacetone. Significant organic aerosol production was observed for glycolaldehyde, acetaldehyde, and formaldehyde only at elevated temperatures in thermogravimetric experiments. In many experiments, the amount of aerosol produced was greater than the sum of all solutes plus nonvolatile solvent impurities, indicating the additional presence of trapped water, likely caused by increasing aerosol-phase viscosity due to oligomer formation.

  7. Adsorption of O2, SO2, and SO3, on nickel oxide - Mechanism for sulfate formation

    Science.gov (United States)

    Mehandru, S. P.; Anderson, A. B.

    1986-01-01

    Calculations based on the atom superposition and electron delocalization molecular orbital technique suggest that O2 will adsorb preferentially end-on at an angle 45 deg from normal on a nickel cation site on the (100) surface of NiO. SO2 adsorption is also stronger on the nickel site; SO2 bonds through the sulfur atom in a plane perpendicular to the surface. Adsorption energies for SO3 on the nickel and oxygen sites are comparable in the preferred orientation in which the SO3 plane is parallel to the surface. The calculations suggest that the strength of adsorption varies as O2 greater than SO2 greater than SO3. On activation, SO3 adsorbed to an O(2-) site forms a trigonal pyramidal SO4 species which yields, with a low barrier, a tetrahedral sulfate anion. Subsequently the anion reorients on the surface. Alternative mechanisms which require the formation of Ni(3+) or O(-) are discussed. NiSO4 thus formed may play a passivating role for the corrosion of Ni at low temperatures in the SO2 + O2 + SO3 atmospheres and an active role at high temperatures, as discussed in the experimental literature.

  8. Adsorption of O2, SO2, and SO3 on nickel oxide. Mechanism for sulfate formation

    Science.gov (United States)

    Mehandru, S. P.; Anderson, A. B.

    1985-01-01

    Calculations based on the atom superposition and electron delocalization molecular orbital (ASED-MO) technique suggest that O2 will adsorb perferentially end-on at an angle 45 deg from normal on a nickel cation site on the (100) surface of NiO. SO2 adsorption is also stronger on the nickel site; SO2 bonds through the sulfur atom is a plane perpendicular to the surface. Adsorption energies for SO3 on the nickel and oxygen sites are comparable in the perferred orientation in which the SO3 plane is parallel to the surface. On activation, SO3 adsorbed to an O2(-) site forms a trigonal pyramidal SO4 species which yields, with a low barrier, a tetrahedral sulfate anion. Subsequently the anion reorients on the surface. Possibilities for alternative mechanisms which require the formation of Ni3(+) or O2(-) are discussed. NiSO4 thus formed leads to the corrosion of Ni at high temperatures in the SO2+O2/SO3 The SO2+O2/SO3 atmosphere, as discussed in the experimental literature.

  9. Cholesteryl ester acyl oxidation and remodeling in murine macrophages: formation of oxidized phosphatidylcholine[S

    Science.gov (United States)

    Hutchins, Patrick M.; Murphy, Robert C.

    2012-01-01

    Cholesterol is an essential component of eukaryotic cell membranes, regulating fluidity and permeability of the bilayer. Outside the membrane, cholesterol is esterified to fatty acids forming cholesterol esters (CEs). Metabolism of CEs is characterized by recurrent hydrolysis and esterification as part of the CE cycle; however, since recombinant 15-lipoxygenase (15-LO) was shown to oxidize cholesteryl linoleate of LDL, there has been interest in CE oxidation, particularly in the context atherogenesis. Studies of oxidized CE (oxCE) metabolism have focused on hydrolysis and subsequent reverse cholesterol transport with little emphasis on the fate the newly released oxidized fatty acyl component. Here, using mass spectrometry to analyze lipid oxidation products, CE metabolism in murine peritoneal macrophages was investigated. Ex vivo macrophage incubations revealed that cellular 15-LO directly oxidized multiple CE substrates from intracellular stores and from extracellular sources. Freshly harvested murine macrophages also contained 15-LO-specific oxCEs, suggesting the enzyme may act as a CE-oxidase in vivo. The metabolic fate of oxCEs, particularly the hydrolysis and remodeling of oxidized fatty acyl chains, was also examined in the macrophage. Metabolism of deuterated CE resulted in the genesis of deuterated, oxidized phosphatidylcholine (oxPC). Further experiments revealed these oxPC species were formed chiefly from the hydrolysis of oxidized CE and subsequent reacylation of the oxidized acyl components into PC. PMID:22665166

  10. Formate, acetate, and propionate as substrates for sulfate reduction in sub-arctic sediments of Southwest Greenland

    DEFF Research Database (Denmark)

    Glombitza, Clemens; Jaussi, Marion; Røy, Hans

    2015-01-01

    Volatile fatty acids (VFAs) are key intermediates in the anaerobic mineralization of organic matter in marine sediments. We studied the role of VFAs in the carbon and energy turnover in the sulfate reduction zone of sediments from the sub-arctic Godthåbsfjord (SW Greenland) and the adjacent...... and acetate, and 0.5 μmol L−1 for propionate) throughout the sulfate reduction zone. Hence, VFAs are turned over while maintaining a stable concentration that is suggested to be under a strong microbial control. Estimated mean diffusion times of acetate between neighboring cells were ... to −16 kJ (mol formate)−1, −68 to −31 kJ (mol acetate)−1, and −124 to −65 kJ (mol propionate)−1. Thus, ΔGr is apparently not determining the in-situ VFA concentrations directly. However, at the bottom of the sulfate zone of the shelf station, acetoclastic sulfate reduction might operate at its energetic...

  11. Identification and functional characterization of a sulfate transporter induced by both sulfur starvation and mycorrhiza formation in Lotus japonicus.

    Science.gov (United States)

    Giovannetti, Marco; Tolosano, Matteo; Volpe, Veronica; Kopriva, Stanislav; Bonfante, Paola

    2014-11-01

    Arbuscular mycorrhizas (AMs) are one of the most widespread symbioses in the world. They allow plants to receive mineral nutrients from the symbiotic fungus which in turn gets back up to 20% of plant carbon and completes its life cycle. Especially in low-nutrient conditions, AM fungi are capable of significantly improving plant phosphate and nitrogen acquisition, but fewer data are available about sulfur (S) nutrition. We focused on S metabolism in Lotus japonicus upon mycorrhizal colonization under sulfur starvation or repletion. We investigated both tissue sulfate concentrations and S-related gene expression, at cell-type or whole-organ level. Gene expression and sulfate tissue concentration showed that Rhizophagus irregularis colonization can improve plant S nutritional status under S starvation. A group 1 sulfate transporter, LjSultr1;2, induced by both S starvation and mycorrhiza formation, was identified. Its transcript was localized in arbuscule-containing cells, which was confirmed with a promoter-GUS assay, and its function was verified through phenotyping of TILLING mutants in nonmycorrhizal seedlings. LjSultr1;2 thus appears to encode a key protein involved in plant sulfate uptake. In contrast to phosphate transporters, a single gene, LjSultr1;2, seems to mediate both direct and symbiotic pathways of S uptake in L. japonicus. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

  12. Encapsulation of ferulic acid ethyl ester in caseinate to suppress off-flavor formation in UHT milk.

    Science.gov (United States)

    Guan, Yongguang; Zhong, Qixin

    2017-12-15

    Phenolic compounds can principally suppress the off-flavor development in ultrahigh temperature (UHT) treated milk, but little has been studied for lipophilic phenolic compounds that are to be encapsulated for even distribution in milk. The objective of this work was to study physicochemical properties of ferulic acid ethyl ester (FAEE) encapsulated in sodium caseinate and the inhibition of volatile formation after UHT processing. The capsules had an average hydrodynamic diameter of 246.2±10.9nm, a polydispersity index of 0.26±0.01, and a zeta-potential of -31.72±0.74mV. The capsules and the encapsulated FAEE were stable after heating at 138°C for 16min and UV radiation at 365nm for 32h. The encapsulated FAEE at a level of 0.18-1.42mg/mL suppressed the formation of 2-acetyl-2-thiazoline in model UHT milk by 32.8-63.2% after 30-day storage at 30°C. Therefore, FAEE encapsulated in caseinate can be potentially used to improve the quality of UHT milk. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Formation of carbonate pipes in the northern Okinawa Trough linked to strong sulfate exhaustion and iron supply

    Science.gov (United States)

    Peng, Xiaotong; Guo, Zixiao; Chen, Shun; Sun, Zhilei; Xu, Hengchao; Ta, Kaiwen; Zhang, Jianchao; Zhang, Lijuan; Li, Jiwei; Du, Mengran

    2017-05-01

    The microbial anaerobic oxidation of methane (AOM), a key biogeochemical process that consumes substantial amounts of methane produced in seafloor sediments, can lead to the formation of carbonate deposits at or beneath the sea floor. Although Fe oxide-driven AOM has been identified in cold seep sediments, the exact mode by which it may influence the formation of carbonate deposits remains poorly understood. Here, we characterize the morphology, petrology and geochemistry of a methane-derived Fe-rich carbonate pipe in the northern Okinawa Trough (OT). We detect abundant authigenic pyrites, as well as widespread trace Fe, within microbial mat-like carbonate veins in the pipe. The in situ δ34S values of these pyrites range from -3.9 to 31.6‰ (VCDT), suggesting a strong consumption of seawater sulfate by sulfate-driven AOM at the bottom of sulfate reduction zone. The positive δ56Fe values of pyrite and notable enrichment of Fe in the OT pipe concurrently indicate that the pyrites are primarily derived from Fe oxides in deep sediments. We propose that the Fe-rich carbonate pipe formed at the bottom of sulfate reduction zone, below which Fe-driven AOM, rather than Fe-oxide reduction coupled to organic matter degradation, might be responsible for the abundantly available Fe2+ in the fluids from which pyrites precipitated. The Fe-rich carbonate pipe described in this study probably represents the first fossil example of carbonate deposits linked to Fe-driven AOM. Because Fe-rich carbonate deposits have also been found at other cold seeps worldwide, we infer that similar processes may play an essential role in biogeochemical cycling of sub-seafloor methane and Fe at continental margins.

  14. Formation of ethyl acetate by Kluyveromyces marxianus on whey: studies of the ester stripping.

    Science.gov (United States)

    Urit, Thanet; Löser, Christian; Wunderlich, Martin; Bley, Thomas

    2011-06-01

    Kluyveromyces marxianus is capable of converting lactose into ethyl acetate offering a chance for an economical reuse of whey. The microbial formation of ethyl acetate as a bulk product calls for an aerobic process and, thus, the highly volatile ethyl acetate is discharged from the aerated bioreactor. This stripping process was modeled and investigated experimentally. The stripping rate was proportional to the gas flow and nearly independent of the stirring rate since the stripping was governed by the absorption capacity of the exhaust gas rather than the phase transfer. Cooling the exhaust gas did not noticeably influence the stripping. One batch experiment is presented in detail to demonstrate the formation of ethyl acetate by K. maxianus DSM 5422 on whey. Further batch experiments showed that a substantial formation of ethyl acetate only occurred when the yeast growth was limited by a lack of trace elements. The highest product yield observed was 0.25 g ethyl acetate per g lactose which is nearly 50% of the theoretical maximum.

  15. Enhanced microemulsion formation in lipid-based drug delivery systems by combining mono-esters of mediumchain fatty acids with di- or tri-esters

    Directory of Open Access Journals (Sweden)

    Darshil P. Patel

    2012-06-01

    Full Text Available To develop strategies for selecting appropriate lipids from mono-, di- and tri-esters of medium-chain fatty acids for the development of lipid-based drug delivery systems, ternary phase diagrams of propylene glycol (PG monocaprylate (Capryol® 90; HLB~7, PG dicaprylocaprate (Labrafac™ PG; HLB~2 and glycerol tricaprylocaprate (Labrafac™ Lipophile WL1349; HLB~2 were determined in combination with a common surfactant, PEG-35 castor oil (Cremophor® EL, HLB~13, and water. Particle size and viscosity in different regions of the phase diagrams were measured, solubility of a model drug, danazol, in different lipid-surfactant mixtures was determined, and dispersion testing by diluting selected preconcentrates with 250 ml 0.01 NHCl was performed. Further, phase diagrams were constructed using binary mixtures of lipids (monoester with diester, or monoester with triester in place of single lipids. The phase diagrams of PG dicaprylocaprate and glycerol tricaprylocaprate were similar, while it was distinctly different for PG monocaprylate. The microemulsion regions in phase diagrams were rather limited for individual lipids, and additionally, the diand tri-esters showed pronounced gel regions in the phase diagrams, which could influence drug release from preconcentrates. The mixing of PG monocaprylate (monoester with PG dicaprylocaprate (diester or glycerol tricaprylocaprate (triester had dramatic effects on the performance of lipids as evidenced by the greatly reduced gel phases, much larger microemulsion regions, faster dispersion of the preconcentrates in an aqueous medium, and smaller particle size of the microemulsions subsequently formed.

  16. Formation of aqueous-phase sulfate during the haze period in China: Kinetics and atmospheric implications

    Science.gov (United States)

    Zhang, Haijie; Chen, Shilu; Zhong, Jie; Zhang, Shaowen; Zhang, Yunhong; Zhang, Xiuhui; Li, Zesheng; Zeng, Xiao Cheng

    2018-03-01

    Sulfate is one of the most important components in the aerosol due to its key role in air pollution and global climate change. Recent work has suggested that reactive nitrogen chemistry in aqueous water can explain the missing source of sulfate in the aqueous water. Herein, we have mapped out the energy profile of the oxidization process of SO2 leading from NO2 and two feasible three-step mechanisms have been proposed. For the oxidation of HOSO2- and HSO3- by the dissolved NO2 in weakly acidic and neutral aerosol (pH ≤ 7), the main contribution to the missing sulfate production comes from the oxidation of HOSO2-. The whole process is a self-sustaining process. For the oxidation of SO32- in alkaline aerosol (pH > 7), the third step - decomposition step of H2O or hydrolysis of SO3 step which are two parallel processes are the rate-limiting steps. The present results are of avail to better understand the missing source of sulfate in the aerosol and hence may lead to better science-based solutions for resolving the severe haze problems in China.

  17. Metabolite kinetics: formation of acetaminophen from deuterated and nondeuterated phenacetin and acetanilide on acetaminophen sulfation kinetics in the perfused rat liver preparation

    International Nuclear Information System (INIS)

    Pang, K.S.; Waller, L.; Horning, M.G.; Chan, K.K.

    1982-01-01

    The role of hepatic intrinsic clearance for metabolite formation from various precursors on subsequent metabolite elimination was was investigated in the once-through perfused rat liver preparation. Two pairs of acetaminophen precursors: [ 14 C] phenacetin-d5 and [ 3 H] phenacetin-do, [ 14 C] acetanilide and [ 3 H] phenacetin were delivered by constant flow (10 ml/min/liver) either by normal or retrograde perfusion to the rat liver preparations. The extents of acetaminophen sulfation were compared within the same preparation. The data showed that the higher the hepatocellular activity (intrinsic clearance) for acetaminophen formation, the greater the extent of subsequent acetaminophen sulfation. The findings were explained on the basis of blood transit time and metabolite duration time. Because of blood having only a finite transit time in liver, the longer the drug requires for metabolite formation, the less time will remain for metabolite sulfation and the less will be the degree of subsequent sulfation. Conversely, when the drug forms the primary metabolite rapidly, a longer time will remain for the metabolite to be sulfated in liver to result in a greater degree of metabolite sulfation. Finally, the effects of hepatic intrinsic clearances for metabolite formation and zonal distribution of enzyme systems for metabolite formation and elimination in liver are discussed

  18. Studies of the acidic components of the Colorado Green River formation oil shale-Mass spectrometric identification of the methyl esters of extractable acids.

    Science.gov (United States)

    Haug, P.; Schnoes, H. K.; Burlingame, A. L.

    1971-01-01

    Study of solvent extractable acidic constituents of oil shale from the Colorado Green River Formation. Identification of individual components is based on gas chromatographic and mass spectrometric data obtained for their respective methyl esters. Normal acids, isoprenoidal acids, alpha, omega-dicarboxylic acids, mono-alpha-methyl dicarboxylic acids and methyl ketoacids were identified. In addition, the presence of monocyclic, benzoic, phenylalkanoic and naphthyl-carboxylic acids, as well as cycloaromatic acids, is demonstrated by partial identification.

  19. Nickel-Catalyzed C-S Bond Formation via Decarbonylative Thioetherification of Esters, Amides and Intramolecular Recombination Fragment Coupling of Thioesters

    KAUST Repository

    Lee, Shao-Chi

    2018-01-15

    A nickel catalyzed cross-coupling protocol for the straightforward C-S bond formation has been developed. Various mercaptans and a wide range of ester and amide substrates bearing various substituents were tolerated in this process which afforded products in good to excellent yields. Furthermore, an intramolecular protocol for the synthesis of thioethers starting from thioesters has been developed. The utility of this protocol has been demonstrated in the synthesis of benzothiophene on the bench top.

  20. Investigation of the formation of deposits of calcium sulfate on a metallic wall: detection and growth initiation

    International Nuclear Information System (INIS)

    Guillermin, Roger

    1970-01-01

    Whereas the formation of calcium sulfate deposits on walls of (water desalination) heat exchanger tubes increases the load loss and decreases the heat exchange coefficient, measuring the load loss or measuring heat transfer in an exchanger could be a method to determine whether scaling occurs. In this research thesis, the author aims at a computational assessing of the sensitivity of such methods in conditions easily obtained in laboratory and allowing, if possible, the identification of the different steps of deposit formation. Then, the author considers some discontinuous methods, possibly more sensitive but more difficult to adjust, but which are not interesting in an industrial point of view: methods based on weighing, on chemical dosing, on radioactive measurements (tracers, auto-radiography, beta backscattering), optical methods and electric methods (piezoelectric quartz, conductivity measurements)

  1. Formation of light absorbing organo-nitrogen species from evaporation of droplets containing glyoxal and ammonium sulfate.

    Science.gov (United States)

    Lee, Alex K Y; Zhao, Ran; Li, Richard; Liggio, John; Li, Shao-Meng; Abbatt, Jonathan P D

    2013-11-19

    In the atmosphere, volatile organic compounds such as glyoxal can partition into aqueous droplets containing significant levels of inorganic salts. Upon droplet evaporation, both the organics and inorganic ions become highly concentrated, accelerating reactions between them. To demonstrate this process, we investigated the formation of organo-nitrogen and light absorbing materials in evaporating droplets containing glyoxal and different ammonium salts including (NH4)2SO4, NH4NO3, and NH4Cl. Our results demonstrate that evaporating glyoxal-(NH4)2SO4 droplets produce light absorbing species on a time scale of seconds, which is orders of magnitude faster than observed in bulk solutions. Using aerosol mass spectrometry, we show that particle-phase organics with high N:C ratios were formed when ammonium salts were used, and that the presence of sulfate ions promoted this chemistry. Since sulfate can also significantly enhance the Henry's law partitioning of glyoxal, our results highlight the atmospheric importance of such inorganic-organic interactions in aqueous phase aerosol chemistry.

  2. Sulfated diesters of okadaic acid and DTX-1: Self-protective precursors of diarrhetic shellfish poisoning (DSP) toxins.

    Science.gov (United States)

    Hu, Tingmo; LeBlanc, Patricia; Burton, Ian W; Walter, John A; McCarron, Pearse; Melanson, Jeremy E; Strangman, Wendy K; Wright, Jeffrey L C

    2017-03-01

    Many toxic secondary metabolites used for defense are also toxic to the producing organism. One important way to circumvent toxicity is to store the toxin as an inactive precursor. Several sulfated diesters of the diarrhetic shellfish poisoning (DSP) toxin okadaic acid have been reported from cultures of various dinoflagellate species belonging to the genus Prorocentrum. It has been proposed that these sulfated diesters are a means of toxin storage within the dinoflagellate cell, and that a putative enzyme mediated two-step hydrolysis of sulfated diesters such as DTX-4 and DTX-5 initially leads to the formation of diol esters and ultimately to the release of free okadaic acid. However, only one diol ester and no sulfated diesters of DTX-1, a closely related DSP toxin, have been isolated leading some to speculate that this toxin is not stored as a sulfated diester and is processed by some other means. DSP components in organic extracts of two large scale Prorocentrum lima laboratory cultures have been investigated. In addition to the usual suite of okadaic acid esters, as well as the free acids okadaic acid and DTX-1, a group of corresponding diol- and sulfated diesters of both okadaic acid and DTX-1 have now been isolated and structurally characterized, confirming that both okadaic acid and DTX-1 are initially formed in the dinoflagellate cell as the non-toxic sulfated diesters. Copyright © 2017. Published by Elsevier B.V.

  3. Design and Construction of Experiment for Direct Electron Irradiation of Uranyl Sulfate Solution: Bubble Formation and Thermal Hydraulics Studies

    Energy Technology Data Exchange (ETDEWEB)

    Chemerisov, Sergey [Argonne National Lab. (ANL), Argonne, IL (United States); Gromov, Roman [Argonne National Lab. (ANL), Argonne, IL (United States); Makarashvili, Vakho [Argonne National Lab. (ANL), Argonne, IL (United States); Heltemes, Thad [Argonne National Lab. (ANL), Argonne, IL (United States); Sun, Zaijing [Argonne National Lab. (ANL), Argonne, IL (United States); Wardle, Kent E. [Argonne National Lab. (ANL), Argonne, IL (United States); Bailey, James [Argonne National Lab. (ANL), Argonne, IL (United States); Quigley, Kevin [Argonne National Lab. (ANL), Argonne, IL (United States); Stepinski, Dominique [Argonne National Lab. (ANL), Argonne, IL (United States); Vandegrift, George [Argonne National Lab. (ANL), Argonne, IL (United States)

    2014-10-01

    Argonne is assisting SHINE Medical Technologies in developing SHINE, a system for producing fission-product 99Mo using a D/T-accelerator to produce fission in a non-critical target solution of aqueous uranyl sulfate. We have developed an experimental setup for studying thermal-hydraulics and bubble formation in the uranyl sulfate solution to simulate conditions expected in the SHINE target solution during irradiation. A direct electron beam from the linac accelerator will be used to irradiate a 20 L solution (sector of the solution vessel). Because the solution will undergo radiolytic decomposition, we will be able to study bubble formation and dynamics and effects of convection and temperature on bubble behavior. These experiments will serve as a verification/ validation tool for the thermal-hydraulic model. Utilization of the direct electron beam for irradiation allows homogeneous heating of a large solution volume and simplifies observation of the bubble dynamics simultaneously with thermal-hydraulic data collection, which will complement data collected during operation of the miniSHINE experiment. Irradiation will be conducted using a 30-40 MeV electron beam from the high-power linac accelerator. The total electron-beam power will be 20 kW, which will yield a power density on the order of 1 kW/L. The solution volume will be cooled on the front and back surfaces and central tube to mimic the geometry of the proposed SHINE solution vessel. Also, multiple thermocouples will be inserted into the solution vessel to map thermal profiles. The experimental design is now complete, and installation and testing are in progress.

  4. Apple Aminoacid Profile and Yeast Strains in the Formation of Fusel Alcohols and Esters in Cider Production.

    Science.gov (United States)

    Eleutério Dos Santos, Caroline Mongruel; Pietrowski, Giovana de Arruda Moura; Braga, Cíntia Maia; Rossi, Márcio José; Ninow, Jorge; Machado Dos Santos, Tâmisa Pires; Wosiacki, Gilvan; Jorge, Regina Maria Matos; Nogueira, Alessandro

    2015-06-01

    The amino acid profile in dessert apple must and its effect on the synthesis of fusel alcohols and esters in cider were established by instrumental analysis. The amino acid profile was performed in nine apple musts. Two apple musts with high (>150 mg/L) and low (content, and four enological yeast strains, were used in cider fermentation. The aspartic acid, asparagine and glutamic acid amino acids were the majority in all the apple juices, representing 57.10% to 81.95%. These three amino acids provided a high consumption (>90%) during fermentation in all the ciders. Principal component analysis (PCA) explained 81.42% of data variability and the separation of three groups for the analyzed samples was verified. The ciders manufactured with low nitrogen content showed sluggish fermentation and around 50% less content of volatile compounds (independent of the yeast strain used), which were mainly 3-methyl-1-butanol (isoamyl alcohol) and esters. However, in the presence of amino acids (asparagine, aspartic acid, glutamic acid and alanine) there was a greater differentiation between the yeasts in the production of fusel alcohols and ethyl esters. High contents of these aminoacids in dessert apple musts are essential for the production of fusel alcohols and most of esters by aromatic yeasts during cider fermentation. © 2015 Institute of Food Technologists®

  5. Estrogenicity and androgenicity screening of PCB sulfate monoesters in human breast cancer MCF-7 cells

    OpenAIRE

    Flor, Susanne; He, Xianran; Lehmler, Hans-Joachim; Ludewig, Gabriele

    2015-01-01

    Recent studies identified PCB sulfate esters as a major product of PCB metabolism. Since hydroxy-PCBs (HO-PCBs), the immediate precursors of PCB sulfates and important contributors to PCB toxicity, were shown to have estrogenic activity, we investigated the estrogenicity/androgenicty of a series of PCB sulfate metabolites. We synthesized the five possible structural sulfate monoester metabolites of PCB 3, a congener shown to be biotransformed to sulfates, a sulfate ester of the paint-specific...

  6. Thermophilic (55 - 65°C) and extreme thermophilic (70 - 80°C) sulfate reduction in methanol and formate-fed UASB reactors

    NARCIS (Netherlands)

    Vallero, M.V.G.; Camarero, E.; Lettinga, G.; Lens, P.N.L.

    2004-01-01

    The feasibility of thermophilic (55-65 degreesC) and extreme thermophilic (70-80 degreesC) sulfate-reducing processes was investigated in three lab-scale upflow anaerobic sludge bed (UASB) reactors fed with either methanol or formate as the sole substrates and inoculated with mesophilic granular

  7. Short communication: Roles of outer membrane protein W (OmpW) on survival and biofilm formation of Cronobacter sakazakii under neomycin sulfate stress.

    Science.gov (United States)

    Ye, Yingwang; Ling, Na; Gao, Jina; Zhang, Maofeng; Zhang, Xiyan; Tong, Liaowang; Ou, Dexin; Wang, Yaping; Zhang, Jumei; Wu, Qingping

    2018-04-01

    Cronobacter sakazakii is associated with severe infections including sepsis, neonatal meningitis, and necrotizing enterocolitis. Antibiotic resistance in Cronobacter species has been documented in recent years, but the genes involved in resistance in Cronobacter strains are poorly understood. In this study, we determined the role of outer membrane protein W (OmpW) on survival rates, morphologic changes, and biofilm formation between wild type (WT) and an OmpW mutant strain (ΔOmpW) under neomycin sulfate stress. Results indicated that the survival rates of ΔOmpW were significantly reduced after half minimum inhibitory concentration (½ MIC) treatment compared with the WT strain. Filamentation of C. sakazakii cells was observed after ½ MIC treatment in WT and ΔOmpW, and morphologic injury, including cell disruption and leakage of cells, was more predominant in ΔOmpW. Under ½ MIC stress, the biofilms of WT and ΔOmpW were significantly decreased, but decreasing rates of biofilm formation in mutant strain were more predominant compared with WT strain. This is the first report to determine the role of OmpW on survival, morphological changes, and biofilm formation in C. sakazakii under neomycin sulfate stress. The findings indicated that OmpW contributed to survival and reduction of morphological injury under neomycin sulfate stress. In addition, enhancing biofilm formation in ΔOmpW may be an alternative advantage for adaptation to neomycin sulfate stress. Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  8. The Origin of the Terra Meridiani Sediments: Volatile Transport and the Formation of Sulfate Bearing Layered Deposits on Mars

    Science.gov (United States)

    Niles, P.B.

    2008-01-01

    The chemistry, sedimentology, and geology of the Meridiani sedimentary deposits are best explained by eolian reworking of the sublimation residue of a large scale ice/dust deposit. This large ice deposit was located in close proximity to Terra Meridiani and incorporated large amounts of dust, sand, and SO2 aerosols generated by impacts and volcanism during early martian history. Sulfate formation and chemical weathering of the initial igneous material is hypothesized to have occurred inside of the ice when the darker mineral grains were heated by solar radiant energy. This created conditions in which small films of liquid water were created in and around the mineral grains. This water dissolved the SO2 and reacted with the mineral grains forming an acidic environment under low water/rock conditions. Subsequent sublimation of this ice deposit left behind large amounts of weathered sublimation residue which became the source material for the eolian process that deposited the Terra Meridiani deposit. The following features of the Meridiani sediments are best explained by this model: The large scale of the deposit, its mineralogic similarity across large distances, the cation-conservative nature of the weathering processes, the presence of acidic groundwaters on a basaltic planet, the accumulation of a thick sedimentary sequence outside of a topographic basin, and the low water/rock ratio needed to explain the presence of very soluble minerals and elements in the deposit. Remote sensing studies have linked the Meridiani deposits to a number of other martian surface features through mineralogic similarities, geomorphic similarities, and regional associations. These include layered deposits in Arabia Terra, interior layered deposits in the Valles Marineris system, southern Elysium/Aeolis, Amazonis Planitia, and the Hellas basin, Aram Chaos, Aureum Chaos, and Ioni Chaos. The common properties shared by these deposits suggest that all of these deposits share a common

  9. Steady state and time-resolved fluorescence spectroscopy of quinine sulfate dication bound to sodium dodecylsulfate micelles: Fluorescent complex formation

    Energy Technology Data Exchange (ETDEWEB)

    Joshi, Sunita; Pant, Debi D., E-mail: ddpant@pilani.bits-pilani.ac.in

    2014-01-15

    Interaction of quinine sulfate dication (QSD) with anionic, sodium dodecylsulphate (SDS) surfactant has been studied at different premicellar, micellar and postmicellar concentrations in aqueous phase using steady state, time-resolved fluorescence and fluorescence anisotropy techniques. At premicellar concentrations of SDS, the decrease in absorbance, appearance of an extra fluorescence band at lower wavelengths and tri-exponential decay behavior of fluorescence, are attributed to complex formation between QSD molecules and surfactant monomers. At postmicellar concentrations the red shift in fluorescence spectrum, increase in quantum yield and increase in fluorescence lifetimes are attributed to incorporation of solute molecules to micelles. At lower concentrations of SDS, a large shift in fluorescence is observed on excitation at the red edge of absorption spectrum and this is explained in terms of distribution of ion pairs of different energies in the ground state and the observed fluorescence lifetime behavior corroborates with this model. The temporal fluorescence anisotropy decay of QSD in SDS micelles allowed determination of restriction on the motion of the fluorophore. All the different techniques used in this study reveal that the photophysics of QSD is very sensitive to the microenvironments of SDS micelles and QSD molecules reside at the water-micelle interface. -- Highlights: • Probe molecule is very sensitive to microenvironment of micelles. • Highly fluorescent ion-pair formation has been observed. • Modulated photophysics of probe molecule in micellar solutions has been observed. • Probe molecules strongly bind with micelles and reside at probe–micelle interface.

  10. Effect of ammonium sulfate and urea on PCDD/F formation from active carbon and possible mechanism of inhibition.

    Science.gov (United States)

    Yan, Mi; Qi, Zhifu; Yang, Jie; Li, Xiaodong; Ren, Jianli; Xu, Zhang

    2014-11-01

    The effect of ammonium sulfate ((NH4)2SO4) and urea (CO(NH2)2) on polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/F) formation from active carbon was investigated in this study. Both additives could significantly inhibit PCDD/F formation, and PCDD/F (TEQ) generation was reduced to 98.5% (98%) or 64.5% (77.2%) after 5% (NH4)2SO4 or CO(NH2)2 was added into model ash, respectively. The inhibition efficiency of PCDDs was higher than the value of PCDFs, however, the reduction of PCDD/F yield was mainly from PCDFs decreasing. In addition, the solid-phase products were reduced more than the gas-phase compounds by inhibitors. By the measurement of chlorine emission in the phase of ion (Cl[Cl(-)]) and molecule gas (Cl[Cl2]), it was observed that both Cl[Cl(-)] and Cl[Cl2] were reduced after inhibitors were added into ash. Cl[Cl2] was reduced to 51.0% by urea addition, which was supposed as one possible mechanism of PCDD/F inhibition. Copyright © 2014. Published by Elsevier B.V.

  11. Evaluation of Sulfated Polysaccharides from the Brown Seaweed Dictyopteris Justii as Antioxidant Agents and as Inhibitors of the Formation of Calcium Oxalate Crystals

    Directory of Open Access Journals (Sweden)

    Karoline Rachel Teodosio Melo

    2013-11-01

    Full Text Available Oxalate crystals and other types of crystals are the cause of urolithiasis, and these are related to oxidative stress. The search for new compounds with antioxidant qualities and inhibitors of these crystal formations is therefore necessary. In this study, we extracted four sulfated polysaccharides, a fucoglucoxyloglucuronan (DJ-0.3v, a heterofucan (DJ-0.4v, and two glucans (DJ-0.5v and DJ-1.2v, from the marine alga Dictyopteris justii. The presence of sulfated polysaccharides was confirmed by chemical analysis and FT-IR. All the sulfated polysaccharides presented antioxidant activity under different conditions in some of the in vitro tests and inhibited the formation of calcium oxalate crystals. Fucan DJ-0.4v was the polysaccharide that showed the best antioxidant activity and was one of the best inhibitors of the crystallization of calcium oxalate. Glucan DJ-0.5v was the second most potent inhibitor of the formation of oxalate crystals, as it stabilized dehydrated oxalate crystals (less aggressive form, preventing them from transforming into monohydrate crystals (more aggressive form. The obtained data lead us to propose that these sulfated polysaccharides are promising agents for use in the treatment of urolithiasis.

  12. The effect of heparan sulfate application on bone formation during distraction osteogenesis.

    Science.gov (United States)

    Gdalevitch, Marie; Kasaai, Bahar; Alam, Norine; Dohin, Bruno; Lauzier, Dominique; Hamdy, Reggie C

    2013-01-01

    Bone morphogenetic proteins (BMPs) are recognized for their ability to induce bone formation in vivo and in vitro. Their osteogenic and osteoinductive properties are tightly regulated by the secretion of specific BMP antagonists, which have been shown to physically bind and sometimes be blocked by the extracellular proteoglycan heparan sulphate side chains (from hereon referred to as HS). The purpose of this study was to investigate if local application of 5 µg of HS proteoglycan to a bone regenerate site in a mouse model of distraction osteogenesis (DO) can accelerate bone healing and affect the expression of key members of the BMP signaling pathway. DO was performed on the right tibia of 115 adult male wild-type mice. At mid-distraction (day 11), half the group was injected locally with 5 µg of HS, while the other half was injected with saline. The mice were sacrificed at 2 time-points: mid-consolidation (34 days) and full consolidation (51 days). The distracted tibial zone was then collected for analysis by μCT, radiology, biomechanical testing, immunohistochemistry, and histology. While μCT data showed no statistically significant difference in bone formation, the results of biomechanical testing in stiffness and ultimate force were significantly lower in the HS-injected bones at 51 days, compared to controls. Immunohistochemistry results also suggested a decrease in expression of several key members of the BMP signaling pathway at 34 days. Furthermore, wound dehiscence and infection rates were significantly elevated in the HS group compared to the controls, which resulted in a higher rate of euthanasia in the treatment group. Our findings demonstrate that exogenous application of 5 µg of HS in the distracted gap of a murine model had a negative impact on bone and wound healing.

  13. The effect of heparan sulfate application on bone formation during distraction osteogenesis.

    Directory of Open Access Journals (Sweden)

    Marie Gdalevitch

    Full Text Available Bone morphogenetic proteins (BMPs are recognized for their ability to induce bone formation in vivo and in vitro. Their osteogenic and osteoinductive properties are tightly regulated by the secretion of specific BMP antagonists, which have been shown to physically bind and sometimes be blocked by the extracellular proteoglycan heparan sulphate side chains (from hereon referred to as HS. The purpose of this study was to investigate if local application of 5 µg of HS proteoglycan to a bone regenerate site in a mouse model of distraction osteogenesis (DO can accelerate bone healing and affect the expression of key members of the BMP signaling pathway. DO was performed on the right tibia of 115 adult male wild-type mice. At mid-distraction (day 11, half the group was injected locally with 5 µg of HS, while the other half was injected with saline. The mice were sacrificed at 2 time-points: mid-consolidation (34 days and full consolidation (51 days. The distracted tibial zone was then collected for analysis by μCT, radiology, biomechanical testing, immunohistochemistry, and histology. While μCT data showed no statistically significant difference in bone formation, the results of biomechanical testing in stiffness and ultimate force were significantly lower in the HS-injected bones at 51 days, compared to controls. Immunohistochemistry results also suggested a decrease in expression of several key members of the BMP signaling pathway at 34 days. Furthermore, wound dehiscence and infection rates were significantly elevated in the HS group compared to the controls, which resulted in a higher rate of euthanasia in the treatment group. Our findings demonstrate that exogenous application of 5 µg of HS in the distracted gap of a murine model had a negative impact on bone and wound healing.

  14. Thioarsenate Formation Coupled with Anaerobic Arsenite Oxidation by a Sulfate-Reducing Bacterium Isolated from a Hot Spring

    Directory of Open Access Journals (Sweden)

    Geng Wu

    2017-07-01

    Full Text Available Thioarsenates are common arsenic species in sulfidic geothermal waters, yet little is known about their biogeochemical traits. In the present study, a novel sulfate-reducing bacterial strain Desulfotomaculum TC-1 was isolated from a sulfidic hot spring in Tengchong geothermal area, Yunnan Province, China. The arxA gene, encoding anaerobic arsenite oxidase, was successfully amplified from the genome of strain TC-1, indicating it has a potential ability to oxidize arsenite under anaerobic condition. In anaerobic arsenite oxidation experiments inoculated with strain TC-1, a small amount of arsenate was detected in the beginning but became undetectable over longer time. Thioarsenates (AsO4-xSx2- with x = 1–4 formed with mono-, di- and tri-thioarsenates being dominant forms. Tetrathioarsenate was only detectable at the end of the experiment. These results suggest that thermophilic microbes might be involved in the formation of thioarsenates and provide a possible explanation for the widespread distribution of thioarsenates in terrestrial geothermal environments.

  15. Chondroitin Sulfate

    Science.gov (United States)

    ... of osteoarthritis. There is some evidence that a skin cream containing chondroitin sulfate in combination with glucosamine sulfate, shark cartilage, and camphor can reduce osteoarthritis symptoms. However, ...

  16. Sulfate radical-based water treatment in presence of chloride: formation of chlorate, inter-conversion of sulfate radicals into hydroxyl radicals and influence of bicarbonate.

    Science.gov (United States)

    Lutze, Holger V; Kerlin, Nils; Schmidt, Torsten C

    2015-04-01

    Sulfate radical (SO4(-)) based oxidation is discussed as a potential water treatment option and is already used in ground water remediation. However, the complex SO4(-) chemistry in various matrices is poorly understood. In that regard, the fast reaction of SO4(-) with Cl(-) is of high importance since Cl(-) belongs to the main constituents in aqueous environments. This reaction yields chlorine atoms (Cl) as primary products. Cl initiate a cascade of subsequent reactions with a pH dependent product pattern. At low pH ( 5 Cl mainly react with water yielding hydroxyl radicals. Thus, at moderate Cl(-) concentrations (mM range) the SO4(-)-based process may be converted into a conventional (hydroxyl radical -based) advanced oxidation process. The conversion of SO4(-) into OH, however, is interrupted in presence of bicarbonate by scavenging of Cl. Copyright © 2014. Published by Elsevier Ltd.

  17. On the suppression of superconducting phase formation in YBCO materials by templated synthesis in the presence of a sulfated biopolymer

    International Nuclear Information System (INIS)

    Smith, Elliott; Schnepp, Zoe; Wimbush, Stuart C.; Hall, Simon R.

    2008-01-01

    The use of biopolymers as templates to control superconductor crystallization is a recent phenomenon and is generating a lot of interest both from the superconductor community and in materials chemistry circles. This work represents a critical finding in the use of such biopolymers, in particular the contraindicatory nature of sulfur when attempting to affect a morphologically controlled synthesis. Synthesis of superconducting nanoparticles was attempted using carrageenan as a morphological template. Reactive sulfate groups on the biopolymer prevent this, producing instead significant quantities of barium sulfate nanotapes. By substituting the biopolymer for structurally analogous, non-sulfated agar, we show that superconducting nanoparticles could be successfully synthesized

  18. Thermochemical Sulfate Reduction Simulation Experiments on the Formation and Distribution of Organic Sulfur Compounds in the Tuha Crude Oil

    Energy Technology Data Exchange (ETDEWEB)

    Yue, Changtao; Li, Shuyuan [China Univ. of Petroleum, Beijing (China); Song, He [Research Institute of Petroleum Engineering of CNPC, Tianjin (China)

    2014-07-15

    Thermochemical sulfate reduction (TSR) was conducted in autoclave on the system of crude oil and MgSO{sub 4} at different temperatures. Gas chromatography pulsed flame photometric detector (GC-PFPD) was used to detected the composition of organic sulfur compounds in oil phase products. The results of the analysis indicate that with increased temperature, the contents of organic sulfur compounds with high molecular weight and thermal stability, such as benzothiophenes and dibenzothiophenes, gradually became dominated. In order to gain greater insight into the formation and distribution of organic sulphur compounds from TSR, positive ion electrospray Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) was used in detecting the detailed elemental composition and distribution of them. The mass spectra showed that the mass range of sulfur compounds was 200-550 Da. Four sulfur class species, S{sub 1}, N{sub 1}S{sub 1}, O{sub 1}S{sub 1} and O{sub 2}S{sub 1}, were assigned in the positive-ion spectrum. Among the identified sulfur compounds, the S{sub 1} class species was dominant. The most abundant S{sub 1} class species increase associated with the DBE value and carbon number increasing which also indicates the evolution of organic sulfur compounds in TSR is from the labile series to the stable one. In pure blank pyrolysis experiments with crude oil cracking without TSR, different composition and distribution of organic sulfur compounds in oil phase products were seen from mass spectra in order to evaluate their pyrolysis behaviors without MgSO{sub 4}. FT-IR and XRD were used in analyzing the products of solid phases. Two distinct crystallographic phases MgO and MgSO{sub 4} are found to coexist in the products which demonstrated the transformation of inorganic sulfur compounds into organosulfur compounds exist in TSR.

  19. Targeted and non-targeted boron complex formation followed by electrospray Fourier transform ion cyclotron mass spectrometry: a novel approach for identifying boron esters with natural organic matter.

    Science.gov (United States)

    Gaspar, Andras; Lucio, Marianna; Harir, Mourad; Schmitt-Kopplin, Philippe

    2011-01-01

    The formation of boron esters was investigated in peat-soluble humified materials with a detailed molecular-level description of boron-organic interactions. Thousands of individually baseline separated signals were obtained from the analysis of natural organic matter of peat samples, using Fourier transform ion cyclotron resonance mass spectrometry. This technique offers unsurpassed isotope-specific mass resolution that can lead to precise molecular formula assignments by means of mathematical data analysis and visualisation techniques, such as mass defect (Kendrick) or elemental ratio (van Krevelen) plots. The analysis of potential boron binding structures within the sample of natural organic matter was described based on prior results. Herein, we describe an algorithm that can be used to effectively distinguish and filter complexes through data obtained from boron-enriched systems with highly intricate mass spectra, such as natural organic matter.

  20. Protective performances of two anti-graffiti treatments towards sulfite and sulfate formation in SO 2 polluted model environment

    Science.gov (United States)

    Carmona-Quiroga, Paula María; Panas, Itai; Svensson, Jan-Erik; Johansson, Lars-Gunnar; Blanco-Varela, María Teresa; Martínez-Ramírez, Sagrario

    2010-11-01

    Specific strategies for protection are being developed to counter both the staining and corrosive effects of polluted air in cities, as well as to allow for efficient removal of unwanted graffiti paintings. These protection strategies employ molecules with tailored functionalities, e.g. being hydrophobic, while maintaining porosity for molecular water vapour permeation. The present study employs SO 2 and water to probe the behaviors of two anti-graffiti treatments, a water-base fluoroalkylsiloxane ("Protectosil Antigraffiti" marketed by Degussa) and an organically modified silicate (Ormosil) synthesized from a polymer chain (polydimethyl siloxane, PDMS) and two network forming alkoxides (Zr propoxide and methyl triethoxy silane, MTES) dissolved in n-propanol, on five building materials, comprising limestone, aged lime mortar, hydrated cement mortar, granite, and brick material. The materials were exposed to a synthetic atmosphere for 20 h in a climate chamber, 0.78 ± 0.03 ppm of SO 2 and 95% RH. Diffuse reflectance Fourier transform infrared (DR-FTIR) spectra were registered before and after exposure in the climate chamber in the cases of both treated and untreated samples. DR-FTIR, scanning electron microscope (SEM) images and energy dispersive X-ray (EDX) analyses, suggest the anti-graffiti Ormosil to suppress formation of calcium sulfite hemihydrate (the primary initial product of the reaction of calcium compounds with SO 2 and water) on carbonate materials (limestone and lime mortar). In case of the granite, brick and cement mortar, Ormosil has a negligible influence on the SO 2 capture. While no sulfite formation was detected by DR-FTIR, gypsum is inferred to form due to metal oxides and minority compounds catalysed oxidation of sulfite to sulfate. In case of brick, this understanding finds support from SEM images as well as EDX. A priori presence of gypsum in hydrated cement mortars prevents positive identification by SEM. However, support for sulfur

  1. Isotopic constraints on the role of hypohalous acids in sulfate aerosol formation in the remote marine boundary layer

    Directory of Open Access Journals (Sweden)

    Q. Chen

    2016-09-01

    Full Text Available Sulfate is an important component of global atmospheric aerosol, and has partially compensated for greenhouse gas-induced warming during the industrial period. The magnitude of direct and indirect radiative forcing of aerosols since preindustrial times is a large uncertainty in climate models, which has been attributed largely to uncertainties in the preindustrial environment. Here, we report observations of the oxygen isotopic composition (Δ17O of sulfate aerosol collected in the remote marine boundary layer (MBL in spring and summer in order to evaluate sulfate production mechanisms in pristine-like environments. Model-aided analysis of the observations suggests that 33–50 % of sulfate in the MBL is formed via oxidation by hypohalous acids (HOX  =  HOBr + HOCl, a production mechanism typically excluded in large-scale models due to uncertainties in the reaction rates, which are due mainly to uncertainties in reactive halogen concentrations. Based on the estimated fraction of sulfate formed via HOX oxidation, we further estimate that daily-averaged HOX mixing ratios on the order of 0.01–0.1 parts per trillion (ppt  =  pmol/mol in the remote MBL during spring and summer are sufficient to explain the observations.

  2. Heterogeneous reaction of SO2 with soot: The roles of relative humidity and surface composition of soot in surface sulfate formation

    Science.gov (United States)

    Zhao, Yan; Liu, Yongchun; Ma, Jinzhu; Ma, Qingxin; He, Hong

    2017-03-01

    The conversion of SO2 to sulfates on the surface of soot is still poorly understood. Soot samples with different fractions of unsaturated hydrocarbons and oxygen-containing groups were prepared by combusting n-hexane under well-controlled conditions. The heterogeneous reaction of SO2 with soot was investigated using in situ attenuated total internal reflection infrared (ATR-IR) spectroscopy, ion chromatography (IC) and a flow tube reactor at the ambient pressure and relative humidity (RH). Water promoted SO2 adsorption and sulfate formation at the RH range from 6% to 70%, while exceeded water condensed on soot was unfavorable for sulfate formation due to inhibition of SO2 adsorption when RH was higher than 80%. The surface composition of soot, which was governed by combustion conditions, also played an important role in the heterogeneous reaction of SO2 with soot. This effect was found to greatly depend on RH. At low RH of 6%, soot with the highest fuel/oxygen ratio of 0.162 exhibited a maximum uptake capacity for SO2 because it contained a large amount of aromatic Csbnd H groups, which acted as active sites for SO2 adsorption. At RH of 54%, soot produced with a fuel/oxygen ratio of 0.134 showed the highest reactivity toward SO2 because it contained appropriate amounts of aromatic Csbnd H groups and oxygen-containing groups, subsequently leading to the optimal surface concentrations of both SO2 and water. These results suggest that variation in the surface composition of soot from different sources and/or resulting from chemical aging in the atmosphere likely affects the conversion of SO2 to sulfates.

  3. On the formation of 4-[N,N-bis(2-chloroethyl)amino]phenyl acetic acid esters of hecogenin and aza-homo-hecogenin and their antileukemic activity.

    Science.gov (United States)

    Camoutsis, Charalambos; Trafalis, Dimitrios; Pairas, George; Papageorgiou, Athanasios

    2005-10-01

    The p-[N,N-bis(2-chloroethyl)amino]phenylacetic acid esters of hecogenin and aza-homo-hecogenin have been prepared and their antineoplastic activity was evaluated against two basic drug screening systems in rodents, P388 lymphocytic and L1210 lymphoid murine leukemias. Among the compounds tested, the p-[N,N-bis(2-chloroethyl)amino]phenylacetic acid ester of aza-homo-hecogenin was appeared to possess a significant higher antileukemic effect. These results support that the alkylating esters of hecogenin produce important antitumor activity as well as, indicate that the aza-homo-hecogenin ester exhibits significantly higher activity due to lactam group (-NHCO-) modification.

  4. Athero-inflammatory nanotherapeutics: Ferulic acid-based poly(anhydride-ester) nanoparticles attenuate foam cell formation by regulating macrophage lipogenesis and reactive oxygen species generation.

    Science.gov (United States)

    Chmielowski, Rebecca A; Abdelhamid, Dalia S; Faig, Jonathan J; Petersen, Latrisha K; Gardner, Carol R; Uhrich, Kathryn E; Joseph, Laurie B; Moghe, Prabhas V

    2017-07-15

    Enhanced bioactive anti-oxidant formulations are critical for treatment of inflammatory diseases, such as atherosclerosis. A hallmark of early atherosclerosis is the uptake of oxidized low density lipoprotein (oxLDL) by macrophages, which results in foam cell and plaque formation in the arterial wall. The hypolipidemic, anti-inflammatory, and antioxidative properties of polyphenol compounds make them attractive targets for treatment of atherosclerosis. However, high concentrations of antioxidants can reverse their anti-atheroprotective properties and cause oxidative stress within the artery. Here, we designed a new class of nanoparticles with anti-oxidant polymer cores and shells comprised of scavenger receptor targeting amphiphilic macromolecules (AMs). Specifically, we designed ferulic acid-based poly(anhydride-ester) nanoparticles to counteract the uptake of high levels of oxLDL and regulate reactive oxygen species generation (ROS) in human monocyte derived macrophages (HMDMs). Compared to all compositions examined, nanoparticles with core ferulic acid-based polymers linked by diglycolic acid (PFAG) showed the greatest inhibition of oxLDL uptake. At high oxLDL concentrations, the ferulic acid diacids and polymer nanoparticles displayed similar oxLDL uptake. Treatment with the PFAG nanoparticles downregulated the expression of macrophage scavenger receptors, CD-36, MSR-1, and LOX-1 by about 20-50%, one of the causal factors for the decrease in oxLDL uptake. The PFAG nanoparticle lowered ROS production by HMDMs, which is important for maintaining macrophage growth and prevention of apoptosis. Based on these results, we propose that ferulic acid-based poly(anhydride ester) nanoparticles may offer an integrative strategy for the localized passivation of the early stages of the atheroinflammatory cascade in cardiovascular disease. Future development of anti-oxidant formulations for atherosclerosis applications is essential to deliver an efficacious dose while

  5. Effects of pH on the formation of 4(5)-Methylimidazole in glucose/ammonium sulfate and glucose/ammonium sulfite caramel model reactions.

    Science.gov (United States)

    Wu, Xinlan; Kong, Fansheng; Huang, Minghui; Yu, Shujuan

    2015-10-01

    The objective of the present study was to detail the change of 4(5)-Methylimidazole (4-MI) in sulfite and sulfate reactions with different initial pH values. Glucose/ammonium sulfate and glucose/ammonium sulfite reaction systems with initial pH conditions 4.9, 5.9, 6.9, 8.0 and 8.6, were heated at 100°C for 2h, respectively. Higher concentration of methylglyoxal (MGO) and 4-MI was detected in thermal treated glucose/ammonium sulfite reaction system than that in sulfate system. The SO 3 2- reacting with MGO and other precursors of 4-MI at higher pH conditions prevented 4-MI formation. However, no inhibition of 4-MI was found at lower pH conditions due to higher reactivity of the nucleophilic NH 4 + than SO 3 2- . The browning intensity of the sulfite system changed scarcely at higher pH values, which was possibly caused by the polyreaction between SO 3 2- and carbonyl, instead of the intermolecular polymerisation of carbonyl in the advanced stage of the Maillard reaction. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Formation of brominated disinfection byproducts from natural organic matter isolates and model compounds in a sulfate radical-based oxidation process

    KAUST Repository

    Wang, Yuru

    2014-12-16

    A sulfate radical-based advanced oxidation process (SR-AOP) has received increasing application interest for the removal of water/wastewater contaminants. However, limited knowledge is available on its side effects. This study investigated the side effects in terms of the production of total organic bromine (TOBr) and brominated disinfection byproducts (Br-DBPs) in the presence of bromide ion and organic matter in water. Sulfate radical was generated by heterogeneous catalytic activation of peroxymonosulfate. Isolated natural organic matter (NOM) fractions as well as low molecular weight (LMW) compounds were used as model organic matter. Considerable amounts of TOBr were produced by SR-AOP, where bromoform (TBM) and dibromoacetic acid (DBAA) were identified as dominant Br-DBPs. In general, SR-AOP favored the formation of DBAA, which is quite distinct from bromination with HOBr/OBr- (more TBM production). SR-AOP experimental results indicate that bromine incorporation is distributed among both hydrophobic and hydrophilic NOM fractions. Studies on model precursors reveal that LMW acids are reactive TBM precursors (citric acid > succinic acid > pyruvic acid > maleic acid). High DBAA formation from citric acid, aspartic acid, and asparagine was observed; meanwhile aspartic acid and asparagine were the major precursors of dibromoacetonitrile and dibromoacetamide, respectively.

  7. Whole-cell bioreduction of aromatic α-keto esters using Candida tenuis xylose reductase and Candida boidinii formate dehydrogenase co-expressed in Escherichia coli

    Directory of Open Access Journals (Sweden)

    Egger Sigrid

    2008-12-01

    Full Text Available Abstract Background Whole cell-catalyzed biotransformation is a clear process option for the production of chiral alcohols via enantioselective reduction of precursor ketones. A wide variety of synthetically useful reductases are expressed heterologously in Escherichia coli to a high level of activity. Therefore, this microbe has become a prime system for carrying out whole-cell bioreductions at different scales. The limited capacity of central metabolic pathways in E. coli usually requires that reductase coenzyme in the form of NADPH or NADH be regenerated through a suitable oxidation reaction catalyzed by a second NADP+ or NAD+ dependent dehydrogenase that is co-expressed. Candida tenuis xylose reductase (CtXR was previously shown to promote NADH dependent reduction of aromatic α-keto esters with high Prelog-type stereoselectivity. We describe here the development of a new whole-cell biocatalyst that is based on an E. coli strain co-expressing CtXR and formate dehydrogenase from Candida boidinii (CbFDH. The bacterial system was evaluated for the synthesis of ethyl R-4-cyanomandelate under different process conditions and benchmarked against a previously described catalyst derived from Saccharomyces cerevisiae expressing CtXR. Results Gene co-expression from a pETDuet-1 vector yielded about 260 and 90 units of intracellular CtXR and CbFDH activity per gram of dry E. coli cell mass (gCDW. The maximum conversion rate (rS for ethyl 4-cyanobenzoylformate by intact or polymyxin B sulphate-permeabilized cells was similar (2 mmol/gCDWh, suggesting that the activity of CbFDH was partly rate-limiting overall. Uncatalyzed ester hydrolysis in substrate as well as inactivation of CtXR and CbFDH in the presence of the α-keto ester constituted major restrictions to the yield of alcohol product. Using optimized reaction conditions (100 mM substrate; 40 gCDW/L, we obtained ethyl R-4-cyanomandelate with an enantiomeric excess (e.e. of 97.2% in a yield of 82

  8. Formation and remodeling of the brain extracellular matrix in neural plasticity: Roles of chondroitin sulfate and hyaluronan.

    Science.gov (United States)

    Miyata, Shinji; Kitagawa, Hiroshi

    2017-10-01

    The extracellular matrix (ECM) of the brain is rich in glycosaminoglycans such as chondroitin sulfate (CS) and hyaluronan. These glycosaminoglycans are organized into either diffuse or condensed ECM. Diffuse ECM is distributed throughout the brain and fills perisynaptic spaces, whereas condensed ECM selectively surrounds parvalbumin-expressing inhibitory neurons (PV cells) in mesh-like structures called perineuronal nets (PNNs). The brain ECM acts as a non-specific physical barrier that modulates neural plasticity and axon regeneration. Here, we review recent progress in understanding of the molecular basis of organization and remodeling of the brain ECM, and the involvement of several types of experience-dependent neural plasticity, with a particular focus on the mechanism that regulates PV cell function through specific interactions between CS chains and their binding partners. We also discuss how the barrier function of the brain ECM restricts dendritic spine dynamics and limits axon regeneration after injury. The brain ECM not only forms physical barriers that modulate neural plasticity and axon regeneration, but also forms molecular brakes that actively controls maturation of PV cells and synapse plasticity in which sulfation patterns of CS chains play a key role. Structural remodeling of the brain ECM modulates neural function during development and pathogenesis. Genetic or enzymatic manipulation of the brain ECM may restore neural plasticity and enhance recovery from nerve injury. This article is part of a Special Issue entitled Neuro-glycoscience, edited by Kenji Kadomatsu and Hiroshi Kitagawa. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Formation of hafnium sulfates with potassium and ammonium in the HfO2-H2SO4-Me2SO4-H2O systems

    International Nuclear Information System (INIS)

    Sozinova, Yu.P.; Motov, D.L.

    1978-01-01

    The formation of double hafnium sulfates with potassium and ammonium has been studied by the method of isothermal solubility at 60 deg C. In systems with potassium double hafnium salts have been obtained for the first time for which the ratio between the components is HfO 2 :H 2 SO 4 :K 2 SO 4 :H 2 O=2:2:1:3, 1:1:1:3, and 1:2:1:0.5. In the system with ammonia double salts have been obtained with the ratio between the components HfO 2 :H 2 SO 4 :(NH 4 )SO 4 :H 2 O=2:1:1:1, 2:3:1:-1, 1:2:1:0, and 1:2:2:2. In contrast to potassium salts, solubility of ammonium salts depends to a greater extent on the solution acidity, and to a lesser extent on the content of (NH 4 ) 2 SO 4 . The transition of simple sulfates into double in the system with (NH 4 ) 2 SO 4 takes place at a high content of (NH 4 ) 2 SO 4 in the solution (about 10 mass.%), whereas in the presence of potassium double salts are formed at about 3.5% of K 2 SO 4 in the solution

  10. Hematite Spherules in Basaltic Tephra Altered Under Aqueous, Acid-Sulfate Conditions on Mauna Kea Volcano, Hawaii: Possible Clues for the Occurrence of Hematite-Rich Spherules in the Burns Formation at Meridiani Planum, Mars

    Science.gov (United States)

    Morris, R. V.; Ming, D. W.; Graff, T. G.; Arvidson, R. E.; Bell, J. F., III; Squyres, S. W.; Mertzman, S. A.; Gruener, J. E.; Golden, D. C.; Robinson, G. A.

    2005-01-01

    Iron-rich spherules (>90% Fe2O3 from electron microprobe analyses) approx.10-100 microns in diameter are found within sulfate-rich rocks formed by aqueous, acid-sulfate alteration of basaltic tephra on Mauna Kea volcano, Hawaii. Although some spherules are nearly pure Fe, most have two concentric compositional zones, with the core having a higher Fe/Al ratio than the rim. Oxide totals less than 100% (93-99%) suggest structural H2O and/or /OH. The transmission Moessbauer spectrum of a spherule-rich separate is dominated by a hematite (alpha-Fe2O3) sextet whose peaks are skewed toward zero velocity. Skewing is consistent with Al(3+) for Fe(3+) substitution and structural H2O and/or /OH. The grey color of the spherules implies specular hematite. Whole-rock powder X-ray diffraction spectra are dominated by peaks from smectite and the hydroxy sulfate mineral natroalunite as alteration products and plagioclase feldspar that was present in the precursor basaltic tephra. Whether spherule formation proceeded directly from basaltic material in one event (dissolution of basaltic material and precipitation of hematite spherules) or whether spherule formation required more than one event (formation of Fe-bearing sulfate rock and subsequent hydrolysis to hematite) is not currently constrained. By analogy, a formation pathway for the hematite spherules in sulfate-rich outcrops at Meridiani Planum on Mars (the Burns formation) is aqueous alteration of basaltic precursor material under acid-sulfate conditions. Although hydrothermal conditions are present on Mauna Kea, such conditions may not be required for spherule formation on Mars if the time interval for hydrolysis at lower temperatures is sufficiently long.

  11. Jarosite versus Soluble Iron-Sulfate Formation and Their Role in Acid Mine Drainage Formation at the Pan de Azúcar Mine Tailings (Zn-Pb-Ag, NW Argentina

    Directory of Open Access Journals (Sweden)

    Jesica Murray

    2014-05-01

    Full Text Available Secondary jarosite and water-soluble iron-sulfate minerals control the composition of acid mine waters formed by the oxidation of sulfide in tailings impoundments at the (Zn-Pb-Ag Pan de Azúcar mine located in the Pozuelos Lagoon Basin (semi-arid climate in Northwest (NW Argentina. In the primary zone of the tailings (9.5 wt % pyrite-marcasite precipitation of anglesite (PbSO4, wupatkite ((Co,Mg,NiAl2(SO44 and gypsum retain Pb, Co and Ca, while mainly Fe2+, Zn2+, Al3+, Mg2+, As3+/5+ and Cd2+ migrate downwards, forming a sulfate and metal-rich plume. In the oxidation zone, jarosite (MFe3(TO42(OH6 is the main secondary Fe3+ phase; its most suitable composition is M = K+, Na+, and Pb2+and TO4 = SO42−; AsO42−. During the dry season, iron-sulfate salts precipitate by capillary transport on the tailings and at the foot of DC2 (tailings impoundment DC2 tailings dam where an acid, Fe2+ rich plume outcrops. The most abundant compounds in the acid mine drainage (AMD are SO42−, Fe2+, Fe3+, Zn2+, Al3+, Mg2+, Cu2+, As3+/5+, Cd2+. These show peak concentrations at the beginning of the wet season, when the soluble salts and jarosite dissolve. The formation of soluble sulfate salts during the dry season and dilution during the wet season conform an annual cycle of rapid metals and acidity transference from the tailings to the downstream environment.

  12. Experimental Results for Direct Electron Irradiation of a Uranyl Sulfate Solution: Bubble Formation and Thermal Hydraulics Studies

    Energy Technology Data Exchange (ETDEWEB)

    Chemerisov, Sergey [Argonne National Lab. (ANL), Argonne, IL (United States); Gromov, R. [Argonne National Lab. (ANL), Argonne, IL (United States); Makarashvili, Vakhtang [Argonne National Lab. (ANL), Argonne, IL (United States); Heltemes, Thad [Argonne National Lab. (ANL), Argonne, IL (United States); Sun, Zaijing [Argonne National Lab. (ANL), Argonne, IL (United States); Wardle, Kent E. [Argonne National Lab. (ANL), Argonne, IL (United States); Bailey, James [Argonne National Lab. (ANL), Argonne, IL (United States); Stepinski, Dominique [Argonne National Lab. (ANL), Argonne, IL (United States); Jerden, James [Argonne National Lab. (ANL), Argonne, IL (United States); Vandegrift, George F. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2015-01-30

    In support of the development of accelerator-driven production of fission product Mo-99 as proposed by SHINE Medical Technologies, a 35 MeV electron linac was used to irradiate depleted-uranium (DU) uranyl sulfate dissolved in pH 1 sulfuric acid at average power densities of 6 kW, 12 kW, and 15 kW. During these irradiations, gas bubbles were generated in the solution due to the radiolytic decomposition of water molecules in the solution. Multiple video cameras were used to record the behavior of bubble generation and transport in the solution. Seven six-channel thermocouples were used to record temperature gradients in the solution from self-heating. Measurements of hydrogen and oxygen concentrations in a helium sweep gas were recorded by a gas chromatograph to estimate production rates during irradiation. These data are being used to validate a computational fluid dynamics (CFD) model of the experiment that includes multiphase flow and a custom bubble injection model for the solution region.

  13. Sulfur deactivation of fatty ester hydrogenolysis catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Brands, D.S.; U-A-Sai, G.; Poels, E.K.; Bliek, A. [Univ. of Amsterdam (Netherlands). Dept. of Chemical Engineering

    1999-08-15

    Trace organosulfur compounds present as natural impurities in oleochemical feedstocks may lead to activation of copper-containing catalysts applied for hydrogenolysis of esters toward fatty alcohols. In this paper, the sulfur deactivation of Cu/SiO{sub 2} and Cu/ZnO/SiO{sub 2} catalysts was studied in the liquid-phase hydrogenolysis of methyl palmitate. The rate of deactivation is fast and increases as a function of the sulfur-containing compound present: octadecanethiol {approx} dihexadecyl disulfide < benzyl isothiocyanate < methyl p-toluene sulfonate < dihexadecyl sulfide < dibenzothiophene. The rapid deactivation is caused by the fact that sulfur is quantitatively removed from the reaction mixture and because mainly surface sulfides are formed under hydrogenolysis conditions. The life time of a zinc-promoted catalyst is up to two times higher than that of the Cu/SiO{sub 2} catalyst, most likely due to zinc surface sulfide formation. The maximum sulfur coverage obtained after full catalyst deactivation with dibenzothiophene and dihexadecyl sulfide--the sulfur compounds that cause the fastest deactivation--may be as low as 0.07. This is due to the fact that decomposition of these compounds as well as the hydrogenolysis reaction itself proceeds on ensembles of copper atoms. Catalyst regeneration studies reveal that activity cannot be regained by reduction or combined oxidation/reduction treatments. XRD, TPR, and TPO results confirm that no distinct bulk copper or zinc sulfide or sulfate phases are present.

  14. Efficient degradation of atrazine by magnetic porous copper ferrite catalyzed peroxymonosulfate oxidation via the formation of hydroxyl and sulfate radicals.

    Science.gov (United States)

    Guan, Ying-Hong; Ma, Jun; Ren, Yue-Ming; Liu, Yu-Lei; Xiao, Jia-Yue; Lin, Ling-qiang; Zhang, Chen

    2013-09-15

    Magnetic porous copper ferrite (CuFe2O4) showed a notable catalytic activity to peroxymonosulfate (PMS). More than 98% of atrazine was degraded within 15 min at 1 mM PMS and 0.1 g/L CuFe2O4. In contrast, CuFe2O4 exhibited no obvious catalytic activity to peroxodisulfate or H2O2. Several factors affecting the catalytic performance of PMS/CuFe2O4 were investigated. Results showed that the catalytic degradation efficiency of atrazine increased with PMS and CuFe2O4 doses, but decreased with the increase of natural organic matters concentration. The catalytic oxidation also showed a dependence on initial pH. The presence of bicarbonate stimulated atrazine degradation by PMS/CuFe2O4 at low concentrations but inhibited the degradation at high concentrations. Furthermore, the reactive species for atrazine degradation in PMS/CuFe2O4 system were identified as hydroxyl radical (HO) and sulfate radical (SO4(·-)) through competition reactions of atrazine and nitrobenzene, instead of commonly used alcohol scavenging, which was not a reliable method in metal oxide catalyzed oxidation. Surface hydroxyl groups of CuFe2O4 were a critical part in radical generation and the copper on CuFe2O4 surface was an active site to catalyze PMS. The catalytic degradation of atrazine by PMS/CuFe2O4 was also effective under the background of actual waters. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Study of Substituted Ester Formation in Red Wine by the Development of a New Method for Quantitative Determination and Enantiomeric Separation of Their Corresponding Acids.

    Science.gov (United States)

    Lytra, Georgia; Franc, Celine; Cameleyre, Margaux; Barbe, Jean-Christophe

    2017-06-21

    A new method was developed for quantifying substituted acids including, where applicable, their various unexplored enantiomeric forms. A new step was added to acids' usual quantification methods, consisting of extraction, derivatization to methyl esters, and gas chromatography analysis: preliminary extraction was performed at basic pH to eliminate ethyl esters, thus avoiding their transesterification during derivatization. Quantitation and enantiomeric distribution of some substituted esters and their corresponding acids were established in 31 commercial Bordeaux red wines from 0 to 20 years old. A strong positive correlation was observed between the age of wine and levels of ethyl 2-methylpropanoate, ethyl 3-methylbutanoate, ethyl 2-methylbutanoate, ethyl (3R)-3-hydroxybutanoate, both enantiomeric forms of ethyl 2-hydroxy-3-methylbutanoate, and ethyl (2S)-2-hydroxy-4-methylpentanoate, but not ethyl (3S)-3-hydroxybutanoate. However, the standard deviations of average concentrations for the corresponding substituted acids were so large that only few correlations between concentrations and age were observed. Concentrations of (2S)-2-hydroxy-3-methylbutanoic acid and (2S)-2-hydroxy-4-methylpentanoic acid increased slightly over time, while (2R)-2-hydroxy-4-methylpentanoic acid levels decreased slightly with the age. Variations in the ratio of substituted ethyl esters to their corresponding acids over time detected thanks to these analytical advances suggested that, in general, acids were continuously esterified during aging.

  16. Nickel-Catalyzed C–CN Bond Formation via Decarbonylative Cyanation of Esters, Amides, and Intramolecular Recombination Fragment Coupling of Acyl Cyanides

    KAUST Repository

    Chatupheeraphat, Adisak

    2017-08-07

    An efficient nickel-catalyzed decarbonylative cyanation reaction which allows the direct functional-group interconversion of readily available esters into the corresponding nitriles was developed. This reaction successfully offers access to structurally diverse nitriles with high efficiency and excellent functional-group tolerance and provides a good alternative to classical synthetic pathways from diazonium salts or organic halide compounds.

  17. Formation of Plant Sterol Oxidation Products in Foods during Baking and Cooking Using Margarine without and with Added Plant Sterol Esters

    NARCIS (Netherlands)

    Lin, Y.; Knol, D.; Menéndez-Carreño, M.; Blom, W.A.M.; Matthee, J.; Janssen, H.G.; Trautwein, E.A.

    2016-01-01

    Plant sterols (PS) in foods are subject to thermal oxidation to form PS oxidation products (POP). This study measured POP contents of 19 foods prepared by typical household baking and cooking methods using margarines without (control) and with 7.5% added PS (as 12.5% PS-esters, PS-margarine). Median

  18. Estrone sulfate source of estrone and estradiol formation in isolated human hair roots: identification of a pathway linked to hair growth phase and subject to site-, gender-, and age-related modulations.

    Science.gov (United States)

    Wehner, Gabriele; Schweikert, Hans-Udo

    2014-04-01

    The present study investigated the metabolism of estrone sulfate into bioactive estrogens in the human hair root, including the effects of hair growth phase, anatomical site, gender, and age. Healthy male (n = 18) and female (n = 20) subjects were investigated. Growing (anagen) and resting (telogen) hair roots were collected from selected scalp and body sites. Estrone sulfate metabolism in the hair root yielded substantial levels of estrone and estradiol. Estrogen synthesis exceeded that associated with aromatization of androgens in a previous study. In subjects hair was lower in men than in women. Comparable levels of estrogen formation were observed in 1) male and female axillary and pubic hair and 2) male beard hair. These levels were higher than the estrogen levels detected in the in scalp hair of men women. In telogen hair from all body sites, the capacity to form estrone from estrone sulfate remained unaffected, whereas the ability to form estradiol decreased by 62% and 86% in men and women, respectively. Estrogen formation from estrone sulfate in sexually dimorphic hair is linked to the hair growth phase and is subject to gender- and age-related modulations. The magnitude of the in situ estrogen synthesis from estrone sulfate and the selective arrest of estradiol synthesis at the end of the hair cycle suggest that this pathway plays a crucial role in the regulation of human hair growth.

  19. The enantioselective b-keto ester reductions by Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    HASSAN TAJIK

    2006-09-01

    Full Text Available The enantioselective yeast reduction of aromatic b-keto esters, by use of potassium dihydrogen phosphate, calcium phosphate (monobasic, magnesium sulfate and ammonium tartrate (diammonium salt (10:1:1:50 in water at pH 7 as a buffer for 72–120 h with 45–90 % conversion to the corresponding aromatic -hydroxy esters was achieved by means of Saccharomyces cerevisiae.

  20. Acetylsalicylic Acid Reduces the Severity of Dextran Sodium Sulfate-Induced Colitis and Increases the Formation of Anti-Inflammatory Lipid Mediators

    Science.gov (United States)

    Köhnke, Thomas; Bilal, Süleyman; Zhou, Xiangzhi; Rothe, Michael; Baumgart, Daniel C.; Weylandt, Karsten H.

    2013-01-01

    The role of non-steroidal anti-inflammatory drugs in inflammatory bowel disease is controversial, as they have been implicated in disease aggravation. Different from other cyclooxygenase inhibitors, acetylsalicylic acid (ASA) enhances the formation of anti-inflammatory and proresolution lipoxins derived from arachidonic acid as well as resolvins from omega-3 polyunsaturated fatty acids such as docosahexaenoic acid (DHA). In this study, we examined the effect of ASA on murine dextran sodium sulfate colitis. A mouse magnetic resonance imaging (MRI) protocol and post mortem assessment were used to assess disease severity, and lipid metabolites were measured using liquid chromatography-coupled tandem mass spectrometry. Decreased colitis activity was demonstrated by phenotype and MRI assessment in mice treated with ASA, and confirmed in postmortem analysis. Analysis of lipid mediators showed sustained formation of lipoxin A4 and an increase of DHA-derived 17-hydroxydocosahexaenoic acid (17-HDHA) after treatment with ASA. Furthermore, in vitro experiments in RAW264.7 murine macrophages demonstrated significantly increased phagocytosis activity after incubation with 17-HDHA, supporting its proresolution effect. These results show a protective effect of ASA in a murine colitis model and could give a rationale for a careful reassessment of ASA therapy in patients with inflammatory bowel disease and particularly ulcerative colitis, possibly combined with DHA supplementation. PMID:24083240

  1. Sulfate Formation Enhanced by a Cocktail of High NOx, SO2, Particulate Matter, and Droplet pH during Haze-Fog Events in Megacities in China: An Observation-Based Modeling Investigation.

    Science.gov (United States)

    Xue, Jian; Yuan, Zibing; Griffith, Stephen M; Yu, Xin; Lau, Alexis K H; Yu, Jian Zhen

    2016-07-19

    In recent years in a few Chinese megacities, fog events lasting one to a few days have been frequently associated with high levels of aerosol loading characterized by high sulfate (as high as 30 μg m(-3)), therefore termed as haze-fog events. The concomitant pollution characteristics include high gas-phase mixing ratios of SO2 (up to 71 ppbv) and NO2 (up to 69 ppbv), high aqueous phase pH (5-6), and smaller fog droplets (as low as 2 μm), resulting from intense emissions from fossil fuel combustion and construction activities supplying abundant Ca(2+). In this work, we use an observation-based model for secondary inorganic aerosols (OBM-SIA) to simulate sulfate formation pathways under conditions of haze-fog events encountered in Chinese megacities. The OBM analysis has identified, at a typical haze-fogwater pH of 5.6, the most important pathway to be oxidation of S(IV) by dissolved NO2, followed by the heterogeneous reaction of SO2 on the aerosol surface. The aqueous phase oxidation of S(IV) by H2O2 is a very minor formation pathway as a result of the high NOx conditions suppressing H2O2 formation. The model results indicate that the unique cocktail of high fogwater pH, high concentrations of NO2, SO2, and PM, and small fog droplets are capable of greatly enhancing sulfate formation. Such haze-fog conditions could lead to rapid sulfate production at night and subsequently high PM2.5 in the morning when the fog evaporates. Sulfate formation is simulated to be highly sensitive to fogwater pH, PM, and precursor gases NO2 and SO2. Such insights on major contributing factors imply that reduction of road dust and NOx emissions could lessen PM2.5 loadings in Chinese megacities during fog events.

  2. Synthesis of Estolide 2-ethylhexyl Ester from Ricinus communis

    International Nuclear Information System (INIS)

    Nazrizawati Ahmad Tajuddin; Nor Habibah Rosli

    2013-01-01

    Estolide 2-ethylhexyl ester synthesized through condensation reaction between ricinoleic acid from castor oil (Ricinus communis) and lauric acid, and then capped with 2-ethylhexyl alcohol. The reaction was continuously conducted under vacuum for 24 hours. Product of 2-ethylhexyl ester was characterized by using Fourier Transform Infrared (FTIR) to determine functional group and Nuclear Magnetic Resonans (NMR) for structure's determination. The presence of ester group at 1738.23 cm -1 wavenumber indicates that the formation of estolide ester has occurred. The vibration peak of C-O at 1174.60 cm -1 and 1117.10 cm -1 support the formation of ester. The presence of CH 2 bending indicated the long-chain compound. The ester methine signal at 3.8669 ppm indicated the estolide linkage in the 1 H-NMR spectrum while the 13 C-NMR showed two carbonyl signals at 173.41 ppm for acid and 173.56 ppm for ester. (author)

  3. The Influence of Various Vibration Frequency on Barium Sulfate Scale Formation Of Vibrated Piping System In The Presence Citric Acid

    Science.gov (United States)

    Karaman, N.; Mangestiyono, W.; Muryanto, S.; Jamari, J.; Bayuseno, A. P.

    2018-01-01

    In this paper, the influence of vibrated piping system for BaSO4 scale formation was investigated. The vibration frequency and presence of citric acid were independent variables determining the kinetics, mass deposit and polymorph of the crystals. Correspondingly, induction time and mass of scale were obtained during the experiments. The crystalline scale was observed by scanning electron microscopy (SEM) and X-Ray Diffraction (XRD) to investigate the morphology and the phase mineral deposits, respectively. This effect indicated that the increase in vibration frequency promoted the increased deposition rate, while the pure barite with a plate-like morphology was produced in the experiments.

  4. Barium Sulfate

    Science.gov (United States)

    ... uses a computer to put together x-ray images to create cross-sectional or three dimensional pictures of the inside of the body). Barium sulfate is in a class of medications called radiopaque contrast media. It works by coating the esophagus, stomach, or ...

  5. Clues on Acid-Sulfate Alteration and Hematite Formation on Earth and Mars From Iron Isotopic Analyses of Terrestrial Analogues From Hawaii

    Science.gov (United States)

    Nie, N. X.; Dauphas, N.; Morris, R. V

    2017-01-01

    The Mars Exploration Rover mission revealed the presence of rocks and minerals indicative of water-rock interactions on Mars. A range of mineralogies have been identified, including hematite spherules (i.e., blueberries), jarosite, Mg-, Ca-sulfates, silica-rich materials and silicate relics from basaltic rocks. The mineral assemblages have been interpreted to be derived from acid-sulfate alteration of basaltic materials. Indeed, the chemical compositions of rocks and soils at Home Plate in Gusev Crater follow the trends expected for acid-sulfate alteration.

  6. Ester Tuiksoo / Ester Tuiksoo ; interv. Piret Tali

    Index Scriptorium Estoniae

    Tuiksoo, Ester, 1965-

    2007-01-01

    Juhan Partsi valitsuse (05.04.2004-13.04.2005) ja Andrus Ansipi valitsuse (13.04.2005-) põllumajandusminister Ester Tuiksoo oma lapsepõlvest ja elukutsevalikust, poliitilise karjääri algusest ja erakonna valikust, ministritöö kogemustest, naistest poliitikas

  7. Adenine sulfate effect on shoot formation of Phaseolus vulgaris L. cultivar `CIAP7247F' via indirect organogenesis

    OpenAIRE

    Novisel Veitía; Lourdes R García; Amanda Martirena Ramírez; Idalmis Bermúdez Caraballoso; Raúl Collado; Damaris Torres; Carlos Romero

    2015-01-01

    This study aimed to determine the effect of adenine sulfate in plant regeneration from callus of Phaseolus vulgaris L. cultivar `CIAP 7247F'. To this, it was added two concentrations (20 and 40 mg l-1) adenine sulfate to the regeneration culture medium and it was included a control to form a total of three treatments. The number of formed shoots was quantified by treatment in the regeneration culture medium and the height of shoot was measured in elongation medium. It was determined that the ...

  8. Parameters affecting ethyl ester production by Saccharomyces cerevisiae during fermentation.

    Science.gov (United States)

    Saerens, S M G; Delvaux, F; Verstrepen, K J; Van Dijck, P; Thevelein, J M; Delvaux, F R

    2008-01-01

    Volatile esters are responsible for the fruity character of fermented beverages and thus constitute a vital group of aromatic compounds in beer and wine. Many fermentation parameters are known to affect volatile ester production. In order to obtain insight into the production of ethyl esters during fermentation, we investigated the influence of several fermentation variables. A higher level of unsaturated fatty acids in the fermentation medium resulted in a general decrease in ethyl ester production. On the other hand, a higher fermentation temperature resulted in greater ethyl octanoate and decanoate production, while a higher carbon or nitrogen content of the fermentation medium resulted in only moderate changes in ethyl ester production. Analysis of the expression of the ethyl ester biosynthesis genes EEB1 and EHT1 after addition of medium-chain fatty acid precursors suggested that the expression level is not the limiting factor for ethyl ester production, as opposed to acetate ester production. Together with the previous demonstration that provision of medium-chain fatty acids, which are the substrates for ethyl ester formation, to the fermentation medium causes a strong increase in the formation of the corresponding ethyl esters, this result further supports the hypothesis that precursor availability has an important role in ethyl ester production. We concluded that, at least in our fermentation conditions and with our yeast strain, the fatty acid precursor level rather than the activity of the biosynthetic enzymes is the major limiting factor for ethyl ester production. The expression level and activity of the fatty acid biosynthetic enzymes therefore appear to be prime targets for flavor modification by alteration of process parameters or through strain selection.

  9. Formation of Plant Sterol Oxidation Products in Foods during Baking and Cooking Using Margarine without and with Added Plant Sterol Esters.

    Science.gov (United States)

    Lin, Yuguang; Knol, Diny; Menéndez-Carreño, María; Blom, Wendy A M; Matthee, Joep; Janssen, Hans-Gerd; Trautwein, Elke A

    2016-01-27

    Plant sterols (PS) in foods are subject to thermal oxidation to form PS oxidation products (POP). This study measured POP contents of 19 foods prepared by typical household baking and cooking methods using margarines without (control) and with 7.5% added PS (as 12.5% PS-esters, PS-margarine). Median POP contents per portion size of cooked foods were 0.57 mg (range 0.05-1.11 mg) with control margarine versus 1.42 mg (range 0.08-20.5 mg) with PS-margarine. The oxidation rate of PS (ORP) was 0.50% (median) with the PS-margarine and 3.66% with the control margarine. Using the PS-margarine, microwave-cooked codfish had the lowest POP content, with 0.08 mg per portion, while shallow-fried potatoes had the highest POP content, 20.5 mg per portion. Median POP contents in cookies, muffins, banana bread, and sponge cake baked with the control or PS-margarine were 0.12 mg (range 0.11-0.21 mg) and 0.24 mg (range 0.19-0.60 mg) per portion, with a corresponding ORP of 1.38% and 0.06%, respectively. POP contents in all the cooked and baked foods did not exceed 20.5 mg per typical portion size. A wide variation in the distribution of individual POP among different foods existed, with 7-keto-PS and 5,6-epoxy-PS being the major oxidation products.

  10. Pseudomonas aeruginosa Biofilm Formation and Persistence, along with the Production of Quorum Sensing-Dependent Virulence Factors, Are Disrupted by a Triterpenoid Coumarate Ester Isolated from Dalbergia trichocarpa, a Tropical Legume

    Science.gov (United States)

    Pottier, Laurent; Huet, Joelle; Rabemanantsoa, Christian; Kiendrebeogo, Martin; Andriantsimahavandy, Abel; Rasamindrakotroka, Andry; Stévigny, Caroline; Duez, Pierre; El Jaziri, Mondher

    2015-01-01

    Recently, extracts of Dalbergia trichocarpa bark have been shown to disrupt P. aeruginosa PAO1 quorum sensing (QS) mechanisms, which are key regulators of virulence factor expression and implicated in biofilm formation. One of the active compounds has been isolated and identified as oleanolic aldehyde coumarate (OALC), a novel bioactive compound that inhibits the formation of P. aeruginosa PAO1 biofilm and its maintenance as well as the expression of the las and rhl QS systems. Consequently, the production of QS-controlled virulence factors including, rhamnolipids, pyocyanin, elastase and extracellular polysaccharides as well as twitching and swarming motilities is reduced. Native acylhomoserine lactones (AHLs) production is inhibited by OALC but exogenous supply of AHLs does not restore the production of virulence factors by OALC-treated cultures, indicating that OALC exerts its effect beyond AHLs synthesis in the QS pathways. Further experiments provided a significant inhibition of the global virulence factor activator gacA by OALC. OALC disorganizes established biofilm structure and improves the bactericidal activity of tobramycin against biofilm-encapsulated PAO1 cells. Finally, a significant reduction of Caenorhabditis elegans paralysis was recorded when the worms were infected with OALC-pre-treated P. aeruginosa. Taken together, these results show that triterpenoid coumarate esters are suitable chemical backbones to target P. aeruginosa virulence mechanisms. PMID:26186595

  11. The Formation Mechanism of Fluorescent Metal Complexes at the LixNi0.5Mn1.5O4-δ/Carbonate Ester Electrolyte Interface

    Energy Technology Data Exchange (ETDEWEB)

    Jarry, Angelique [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Gottis, Sebastien [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Yu, Young-Sang [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of Illinois, Chicago, IL (United States); Roque-Rosell, Josep [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Kim, Chunjoong [Univ. of Illinois, Chicago, IL (United States); Cabana, Jordi [Univ. of Illinois, Chicago, IL (United States); Kerr, John B [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Kostecki, Robert [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2015-03-18

    Electrochemical oxidation of carbonate esters at the LixNi0.5Mn1.5O4-δ/electrolyte interface results in Ni/Mn dissolution and surface film formation, which negatively affect the electrochemical performance of Li-ion batteries. Ex situ X-ray absorption (XRF/XANES), Raman, and fluorescence spectroscopy, along with imaging of LixNi0.5Mn1.5O4-δ positive and graphite negative electrodes from tested Li-ion batteries, reveal the formation of a variety of MnII/III and NiII complexes with β-diketonate ligands. These metal complexes, which are generated upon anodic oxidation of ethyl and diethyl carbonates at LixNi0.5Mn1.5O4-δ, form a surface film that partially dissolves in the electrolyte. The dissolved MnIII complexes are reduced to their MnII analogues, which are incorporated into the solid electrolyte interphase surface layer at the graphite negative electrode. This work elucidates possible reaction pathways and evaluates their implications for Li+ transport kinetics in Li-ion batteries.

  12. The Formation Mechanism of Fluorescent Metal Complexes at the Li x Ni 0.5 Mn 1.5 O 4-δ /Carbonate Ester Electrolyte Interface

    Energy Technology Data Exchange (ETDEWEB)

    Jarry, Angélique; Gottis, Sébastien; Yu, Young-Sang; Roque-Rosell, Josep; Kim, Chunjoong; Cabana, Jordi; Kerr, John; Kostecki, Robert

    2015-03-18

    Electrochemical oxidation of carbonate esters at the LixNi0.5Mn1.5O4-δ/electrolyte interface results in Ni/Mn dissolution and surface film formation, which negatively affect the electrochemical performance of Li-ion batteries. Ex situ X-ray absorption (XRF/XANES), Raman, and fluorescence spectroscopy, along with imaging of LixNi0.5Mn1.5O4-δ positive and graphite negative electrodes from tested Li-ion batteries, reveal the formation of a variety of MnII/III and NiII complexes with β-diketonate ligands. These metal complexes, which are generated upon anodic oxidation of ethyl and diethyl carbonates at LixNi0.5Mn1.5O4-δ, form a surface film that partially dissolves in the electrolyte. The dissolved MnIII complexes are reduced to their MnII analogues, which are incorporated into the solid electrolyte interphase surface layer at the graphite negative electrode. This work elucidates possible reaction pathways and evaluates their implications for Li+ transport kinetics in Li-ion batteries.

  13. Incorporation of either molybdenum or tungsten into formate dehydrogenase from Desulfovibrio alaskensis NCIMB 13491; EPR assignment of the proximal iron-sulfur cluster to the pterin cofactor in formate dehydrogenases from sulfate-reducing bacteria.

    Science.gov (United States)

    Brondino, Carlos D; Passeggi, Mario C G; Caldeira, Jorge; Almendra, Maria J; Feio, Maria J; Moura, Jose J G; Moura, Isabel

    2004-03-01

    We report the characterization of the molecular properties and EPR studies of a new formate dehydrogenase (FDH) from the sulfate-reducing organism Desulfovibrio alaskensis NCIMB 13491. FDHs are enzymes that catalyze the two-electron oxidation of formate to carbon dioxide in several aerobic and anaerobic organisms. D. alaskensis FDH is a heterodimeric protein with a molecular weight of 126+/-2 kDa composed of two subunits, alpha=93+/-3 kDa and beta=32+/-2 kDa, which contains 6+/-1 Fe/molecule, 0.4+/-0.1 Mo/molecule, 0.3+/-0.1 W/molecule, and 1.3+/-0.1 guanine monophosphate nucleotides. The UV-vis absorption spectrum of D. alaskensis FDH is typical of an iron-sulfur protein with a broad band around 400 nm. Variable-temperature EPR studies performed on reduced samples of D. alaskensis FDH showed the presence of signals associated with the different paramagnetic centers of D. alaskensis FDH. Three rhombic signals having g-values and relaxation behavior characteristic of [4Fe-4S] clusters were observed in the 5-40 K temperature range. Two EPR signals with all the g-values less than two, which accounted for less than 0.1 spin/protein, typical of mononuclear Mo(V) and W(V), respectively, were observed. The signal associated with the W(V) ion has a larger deviation from the free electron g-value, as expected for tungsten in a d(1) configuration, albeit with an unusual relaxation behavior. The EPR parameters of the Mo(V) signal are within the range of values typically found for the slow-type signal observed in several Mo-containing proteins belonging to the xanthine oxidase family of enzymes. Mo(V) resonances are split at temperatures below 50 K by magnetic coupling with one of the Fe/S clusters. The analysis of the inter-center magnetic interaction allowed us to assign the EPR-distinguishable iron-sulfur clusters with those seen in the crystal structure of a homologous enzyme.

  14. Triple oxygen and sulfur isotope analyses of sulfate extracted from voluminous volcanic ashes in the Oligocene John Day Formation: insight into dry climate conditions and ozone contribution to supereruptions

    Science.gov (United States)

    Workman, J.; Bindeman, I. N.; Martin, E.; Retallack, G.; Palandri, J. L.; Weldon, N.

    2014-12-01

    Large volume pyroclastic silicic eruptions emit hundreds of megatons of SO2 into the troposphere and stratosphere that is oxidized into sulfuric acid (H2SO4) by a variety of reactions with mass independent oxygen signatures (MIF), Δ17O>0. Sulfuric acid is then preserved as gypsum in parental volcanic deposits. Diagenic effects are mass dependent and can dilute, but otherwise do not affect MIF ratios. Pleistocene Yellowstone and Bishop tuffs and modern volcanic eruptions preserved under arid climate conditions in North American playa lakes, preserve small amounts of volcanic sulfate as gypsum. This gypsum's Δ17O>0, in combination with isotopic variations of δ18O, δ33S and δ34S is distinct from sedimentary sulfate and reveals its original MIF sulfate isotopic signal and the effect of super eruptions on the atmosphere, and ozone consumption in particular. We use linear algebraic equations to resolve volcanic versus sedimentary (MIF=0) sources. We have found that many large volume ignimbrites have very high initial Δ17O in volcanic sulfate that can only be acquired from reaction with stratospheric ozone. We here investigate nine thick (>2 m) ash beds ranging in age from ~33-23 Ma in the John Day Formation of central Oregon, including massive 28.6 Ma Picture Gorge tuff of newly identified Crooked River supercaldera. The 28.6 Ma Picture Gorge tuff (PGT) has the highest measured Δ17O of 3.5‰, and other tuffs (Tin Roof, Biotite, Deep Creek) have +1.3 to 3.4‰ Δ17O excesses. Sulfate from modern smaller tropospheric eruptions studied for comparison have a resolvable 0.4‰ range consistent with liquid-phase based H2O2 oxidation. The PGT is coeval with the ignimbrite flare-up in western N. America, the 28-29 Ma eruption of the 5000 km3 Fish Canyon tuff and the 28 Ma Never Summer Field eruption in Nebraska-Colorado that have the highest measured Δ17O of 6‰ (Bao et al. 2003). We speculate on the climatic/atmospheric effects of these multiple ~28 Ma supereruptions

  15. On the roles and regulation of chondroitin sulfate and heparan sulfate in zebrafish pharyngeal cartilage morphogenesis

    DEFF Research Database (Denmark)

    Holmborn, Katarina; Habicher, Judith; Kasza, Zsolt

    2012-01-01

    The present study addresses the roles of heparan sulfate (HS) proteoglycans and chondroitin sulfate (CS) proteoglycans in the development of zebrafish pharyngeal cartilage structures. uxs1 and b3gat3 mutants, predicted to have impaired biosynthesis of both HS and CS because of defective formation...

  16. Estrogenicity and androgenicity screening of PCB sulfate monoesters in human breast cancer MCF-7 cells.

    Science.gov (United States)

    Flor, Susanne; He, Xianran; Lehmler, Hans-Joachim; Ludewig, Gabriele

    2016-02-01

    Recent studies identified polychlorinated biphenyl (PCB) sulfate esters as a major product of PCB metabolism. Since hydroxy-PCBs (HO-PCBs), the immediate precursors of PCB sulfates and important contributors to PCB toxicity, were shown to have estrogenic activity, we investigated the estrogenicity/androgenicty of a series of PCB sulfate metabolites. We synthesized the five possible structural sulfate monoester metabolites of PCB 3, a congener shown to be biotransformed to sulfates, a sulfate ester of the paint-specific congener PCB 11, and sulfate monoesters of two HO-PCBs reported to interact with sulfotransferases (PCB 39, no ortho chlorines, and PCB 53, 3 ortho chlorines). We tested these PCB sulfates and 4'-HO-PCB 3 as positive control for estrogenic, androgenic, anti-estrogenic, and anti-androgenic activity in the E- and A-screen with human breast cancer MCF7-derived cells at 100 μM-1 pM concentrations. Only 4'-HO-PCB 3 was highly cytotoxic at 100 μM. We observed structure-activity relationships: compounds with a sulfate group in the chlorine-containing ring of PCB 3 (2PCB 3 and 3PCB 3 sulfate) showed no interaction with the estrogen (ER) and androgen (AR) receptor. The 4'-HO-PCB 3 and its sulfate ester had the highest estrogenic effect, but at 100-fold different concentrations, i.e., 1 and 100 μM, respectively. Four of the PCB sulfates were estrogenic (2'PCB 3, 4'PCB 3, 4'PCB 39, and 4'PCB 53 sulfates; at 100 μM). These sulfates and 3'PCB 3 sulfate also exhibited anti-estrogenic activity, but at nM and pM concentrations. The 4'PCB 3 sulfate (para-para' substituted) had the strongest androgenic activity, followed by 3'PCB 3, 4'PCB 53, 4PCB11, and 4PCB 39 sulfates and the 4'HO-PCB 3. In contrast, anti-androgenicity was only observed with the two compounds that have the sulfate group in ortho- or meta- position in the second ring (2'PCB 3 and 3'PCB 3 sulfate). No dose-response was observed in any screen, but, with exception of estrogenic activity (only seen

  17. Valyl benzyl ester chloride

    Directory of Open Access Journals (Sweden)

    Grzegorz Dutkiewicz

    2010-02-01

    Full Text Available In the title compound (systematic name: 1-benzyloxy-3-methyl-1-oxobutan-2-aminium chloride, C12H18NO2+·Cl−, the ester group is approximately planar, with a maximum deviation of 0.040 (2 Å from the least-squares plane, and makes a dihedral angle of 28.92 (16° with the phenyl ring. The crystal structure is organized by N—H...Cl hydrogen bonds which join the two components into a chain along the b axis. Pairs of chains arranged antiparallel are interconnected by further N—H...Cl hydrogen bonds, forming eight-membered rings. Similar packing modes have been observed in a number of amino acid ester halides with a short unit-cell parameter of ca 5.5 Å along the direction in which the chains run.

  18. Sulfate reduction in freshwater peatlands

    International Nuclear Information System (INIS)

    Oequist, M.

    1996-01-01

    This text consist of two parts: Part A is a literature review on microbial sulfate reduction with emphasis on freshwater peatlands, and part B presents the results from a study of the relative importance of sulfate reduction and methane formation for the anaerobic decomposition in a boreal peatland. The relative importance of sulfate reduction and methane production for the anaerobic decomposition was studied in a small raised bog situated in the boreal zone of southern Sweden. Depth distribution of sulfate reduction- and methane production rates were measured in peat sampled from three sites (A, B, and C) forming an minerotrophic-ombrotrophic gradient. SO 4 2- concentrations in the three profiles were of equal magnitude and ranged from 50 to 150 μM. In contrast, rates of sulfate reduction were vastly different: Maximum rates in the three profiles were obtained at a depth of ca. 20 cm below the water table. In A it was 8 μM h -1 while in B and C they were 1 and 0.05 μM h -1 , respectively. Methane production rates, however, were more uniform across the three nutrient regimes. Maximum rates in A (ca. 1.5 μg d -1 g -1 ) were found 10 cm below the water table, in B (ca. 1.0 μg d -1 g -1 ) in the vicinity of the water table, and in C (0.75 μg d -1 g -1 ) 20 cm below the water table. In all profiles both sulfate reduction and methane production rates were negligible above the water table. The areal estimates of methane production for the profiles were 22.4, 9.0 and 6.4 mmol m -2 d -1 , while the estimates for sulfate reduction were 26.4, 2.5, and 0.1 mmol m -2 d -1 , respectively. The calculated turnover times at the sites were 1.2, 14.2, and 198.7 days, respectively. The study shows that sulfate reducing bacteria are important for the anaerobic degradation in the studied peatland, especially in the minerotrophic sites, while methanogenic bacteria dominate in ombrotrophic sites Examination paper. 67 refs, 6 figs, 3 tabs

  19. Acid Sulfate Alteration on Mars

    Science.gov (United States)

    Ming, D. W.; Morris, R. V.

    2016-01-01

    aqueous formation of sulfate-bearing phases under acidic conditions on the surface of Mars including (1) sulfuric acid weathering of basaltic materials; (2) oxidative weathering of ultramafic igneous rocks containing sulfides; (3) acid fog weathering of basaltic materials, and (4) near-neutral pH subsurface solutions rich in Fe2(+) that were rapidly oxidized to Fe3(+), which produced excess acidity as iron was oxidized on exposure to O2 or photo-oxidized by ultraviolet radiation at the martian surface. Next, we briefly describe evidence for these hypothesis.

  20. Significant enhancement of 11-Hydroxy-THC detection by formation of picolinic acid esters and application of liquid chromatography/multi stage mass spectrometry (LC-MS(3) ): Application to hair and oral fluid analysis.

    Science.gov (United States)

    Thieme, Detlef; Sachs, Ulf; Sachs, Hans; Moore, Christine

    2015-07-01

    Formation of picolinic acid esters of hydroxylated drugs or their biotransformation products is a promising tool to improve their mass spectrometric ionization efficiency, alter their fragmentation behaviour and enhance sensitivity and specificity of their detection. The procedure was optimized and tested for the detection of cannabinoids, which proved to be most challenging when dealing with alternative specimens, for example hair and oral fluid. In particular, the detection of the THC metabolites hydroxyl-THC and carboxy-THC requires ultimate sensitivity because of their poor incorporation into hair or saliva. Both biotransformation products are widely accepted as incorporation markers to distinguish drug consumption from passive contamination. The derivatization procedure was carried out by adding a mixture of picolinic acid, 4-(dimethylamino)pyridine and 2-methyl-6-nitrobenzoic anhydride in tetrahydrofuran/triethylamine to the dry extraction residues. Resulting derivatives were found to be very stable and could be reconstituted in aqueous or organic buffers and subsequently analyzed by liquid chromatography-mass spectrometry (LC-MS). Owing to the complex consecutive fragmentation patterns, the application of multistage MS3 proved to be extremely useful for a sensitive identification of doubly picolinated hydroxy-THC in complex matrices. The detection limits - estimated by comparison of corresponding signal-to-noise ratios - increased by a factor of 100 following picolination. All other species examined, like cannabinol, THC, cannabidiol, and carboxy-THC, could also be derivatized exhibiting only moderate sensitivity improvements. The assay was systematically tested using hair samples and exemplarily applied to oral fluid. Concentrations of OH-THC identified in THC-positive hair samples ranged from 0.02 to 0.29pg/mg. Copyright © 2014 John Wiley & Sons, Ltd.

  1. Method of making alkyl esters

    Science.gov (United States)

    Elliott, Brian

    2010-09-14

    Methods of making alkyl esters are described herein. The methods are capable of using raw, unprocessed, low-cost feedstocks and waste grease. Generally, the method involves converting a glyceride source to a fatty acid composition and esterifying the fatty acid composition to make alkyl esters. In an embodiment, a method of making alkyl esters comprises providing a glyceride source. The method further comprises converting the glyceride source to a fatty acid composition comprising free fatty acids and less than about 1% glyceride by mass. Moreover, the method comprises esterifying the fatty acid composition in the presence of a solid acid catalyst at a temperature ranging firm about 70.degree. C. to about 120.degree. C. to produce alkyl esters, such that at least 85% of the free fatty acids are converted to alkyl esters. The method also incorporates the use of packed bed reactors for glyceride conversion and/or fatty acid esterification to make alkyl esters.

  2. Apomorphine and its esters

    DEFF Research Database (Denmark)

    Borkar, Nrupa; Chen, Zhizhong; Saaby, Lasse

    2016-01-01

    Oral delivery of apomorphine via prodrug principle may be a potential treatment for Parkinson's disease. The purpose of this study was to investigate the transport and stability of apomorphine and its esters across Caco-2 cell monolayer and their affinity towards chylomicrons. Apomorphine......, monolauroyl apomorphine (MLA) and dilauroyl apomorphine (DLA) were subjected to apical to basolateral (A-B) and basolateral to apical (B-A) transport across Caco-2 cell monolayer. The stability of these compounds was also assessed by incubation at intestinal pH and physiological pH with and without Caco-2...

  3. Rare earth sulfates

    International Nuclear Information System (INIS)

    Komissarova, L.N.; Shatskij, V.M.; Pokrovskij, A.N.; Chizhov, S.M.; Bal'kina, T.I.; Suponitskij, Yu.L.

    1986-01-01

    Results of experimental works on the study of synthesis conditions, structure and physico-chemical properties of rare earth, scandium and yttrium sulfates, have been generalized. Phase diagrams of solubility and fusibility, thermodynamic and crystallochemical characteristics, thermal stability of hydrates and anhydrous sulfates of rare earths, including normal, double (with cations of alkali and alkaline-earth metals), ternary and anion-mixed sulfates of rare earths, as well as their adducts, are considered. The state of ions of rare earths, scandium and yttrium in aqueous sulfuric acid solutions is discussed. Data on the use of rare earth sulfates are given

  4. Isolation and characterization of a unique sulfated ganglioside, sulfated GM1a, from rat kidney.

    Science.gov (United States)

    Tadano-Aritomi, K; Kubo, H; Ireland, P; Hikita, T; Ishizuka, I

    1998-04-01

    A novel class of sulfoglycosphingolipid, a sulfate analog of ganglioside, was isolated from mammals for the first time. This sulfated ganglioside was purified from rat kidney by column chromatographies on anion exchangers and silica beads. One-dimensional 1H NMR, compositional and permethylation analyses showed that this glycolipid has a Gg4Cer core with 1 mol each of sulfate ester and N- glycolylneuraminic acid (NeuGc) at C-3 of galactose. The major ceramide consisted of nonhydroxy fatty acids (24:0 and 22:0) and 4-hydroxysphinganine (t18:0), deduced from the compositional analysis and negative liquid secondary ion mass spectrometry (LSIMS). Mild acid hydrolysis and solvolysis produced compounds which correspond to Gg4Cer IV3-sulfate (SM1b) and II3NeuGcalpha-Gg4Cer (GM1a (NeuGc)), respectively. The abundant ions characteristic for sulfated mono- and disaccharides in high-energy collision-induced dissociation (CID) spectra were consistent with the structure at the non-reducing terminus, HSO3 -O- Hex -O- HexNAc- rather than the alternative structure, NeuGc -O- Hex -O- HexNAc-. The two-dimensional 1H NMR further evidenced the presence of a 3 -O- sulfated galactose in the molecule. From these results the complete structure was proposed to be HSO3-3Galbeta-3GalNAcbeta-4(NeuGcalpha-3)Galb eta-4Glcbeta-1Cer (II3NeuGcalpha-Gg4Cer IV3-sulfate).

  5. Atmospheric oxidation of selected alcohols and esters

    Energy Technology Data Exchange (ETDEWEB)

    Becker, K.H.; Cavalli, F.

    2001-03-01

    The decision whether it is appropriate and beneficial for the environment to deploy specific oxygenated organic compounds as replacements for traditional solvent types requires a quantitative assessment of their potential atmospheric impacts including tropospheric ozone and other photooxidant formation. This involves developing chemical mechanisms for the gasphase atmospheric oxidation of the compounds which can be reliably used in models to predict their atmospheric reactivity under a variety of environmental conditions. Until this study, there was very little information available concerning the atmospheric fate of alcohols and esters. The objectives of this study were to measure the atmospheric reaction rates and to define atmospheric reaction mechanisms for the following selected oxygenated volatile organic compounds: the alcohols, 1-butanol and 1-pentanol, and the esters, methyl propionate and dimethyl succinate. The study has successfully addressed these objectives. (orig.)

  6. Esters with water esters 2-c to 6-c

    CERN Document Server

    Getzen, F W; Hefter, G T; Maczynski, Andrzej

    1992-01-01

    This volume is the first of two devoted to esters and water. It includes solubility data for binary systems containing an ester and water up to the end of 1988. The critical evaluations were all prepared by one author and an introductory section has been included to elaborate the philosophy and methodology followed in the evaluations.

  7. Evaluation of commercial and sulfated ZrO{sub 2} aiming application catalysis; Avaliacao de ZrO{sub 2} comercial e sulfatada visando aplicacao em catalise

    Energy Technology Data Exchange (ETDEWEB)

    Silva, F.N.; Dantas, J.; Costa, A.C.F.M., E-mail: nilson.s@hotmail.com [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Pos-Graduacao em Engenharia de Materiais; Pallone, E.M.J.A. [Universidade de Sao Paulo (USP), Pirassununga, SP (Brazil). Departamento de Ciencias Basicas; Dutra, R.C.L. [Instituto de Aeronautica e Espaco (AQI/IAE), Sao Jose dos Campos, SP (Brazil). Divisao de Quimica

    2014-07-01

    This study evaluates the performance of commercial and sulfated ZrO{sub 2} for future application in catalysis. Commercial ZrO{sub 2} was provided by the company Saint-Gobain Zirpro. The sulfation occurred with SO{sub 4}{sup -2} ion content of 30% compared to the mass of ZrO{sub 2}. The samples were characterized by XRD, FTIR, EDX and GD. The results revealed the formation of a monoclinic phase for the commercial sample, and a monoclinic major phase with tetragonal traces for the sulfated sample. The commercial ZrO{sub 2} showed a narrow, bimodal and asymmetric agglomerates distribution, while the sulfated sample showed a narrow, tetramodal and asymmetric agglomerates distribution. The presence of traces of the tetragonal phase in the SO{sub 4}{sup -2}/ZrO{sub 2} XRD, and the presence of SO{sub 3} in the EDX were good indicators for future use in catalysis to provide ester. (author)

  8. Heparan sulfate in skeletal muscle development

    International Nuclear Information System (INIS)

    Noonan, D.M.

    1985-01-01

    In this study, chick breast skeletal muscle cells developing in vitro from myoblasts to myotubes were found to synthesize heparan sulfate (HS), chrondroitin-6-sulfate, chrondroitin-4-sulfate, dermatan sulfate, unsulfated chrondroitin and hyaluronic acid in both the substratum attached material (SAM) and the cellular fraction. SAM was found to contain predominantly chrondroitin-6-sulfate and relatively little HS whereas the cellular fraction contained relatively higher levels of HS and lower levels of chrondroitin-6-sulfate. Hyaluronic acid was also a major component in both fractions with the other glycosaminoglycan isomers present as minor components. Muscle derived fibroblast cultures had higher levels of dermatan sulfate in the cell layer and higher levels of HS in the SAM fraction than did muscle cultures. The structure of the proteoglycans were partially characterized in 35 SO 4 2- radio-labeled cultures which indicated an apparent increase in the hydrodynamic size of the cell fraction heparan sulfate proteoglycan (HS PG). Myotubes incorporated 35 SO 4 2- into HS PG at a rate 3 times higher than myoblasts. The turnover rate of HS in the cellular fraction was the same for myoblasts and myotubes, with a t/sub 1/2/ of approximately 5 hours. Fibroblasts in culture synthesized the smallest HS PG, and incorporated 35 SO 4 2- into HS PG at a rate lower than that of myotubes. Studies in which fusion was reversibly inhibited with decreased medium [Ca ++ ] closely linked the increased synthesis of cell fraction, but not SAM fraction, HS with myotube formation. However, decreasing medium calcium appeared to cause significant alterations in the metabolism of inorganic sulfate

  9. Carboxylic ester hydrolases from hyperthermophiles

    NARCIS (Netherlands)

    Levisson, M.; Oost, van der J.; Kengen, S.W.M.

    2009-01-01

    Carboxylic ester hydrolyzing enzymes constitute a large group of enzymes that are able to catalyze the hydrolysis, synthesis or transesterification of an ester bond. They can be found in all three domains of life, including the group of hyperthermophilic bacteria and archaea. Esterases from the

  10. Lipoate ester multifunctional lubricant additives

    Science.gov (United States)

    Seven lipoate esters were synthesized by esterification of lipoic acid with different structures of alcohols in the presence of a solid acid catalyst and without solvent. The esters were obtained in good yield, characterized using 1H NMR and GPC; and their physical properties investigated. Four of t...

  11. The ceric sulfate dosimeter

    DEFF Research Database (Denmark)

    Bjergbakke, Erling

    1970-01-01

    The process employed for the determination of absorbed dose is the reduction of ceric ions to cerous ions in a solution of ceric sulfate and cerous sulfate in 0.8N sulfuric acid: Ce4+→Ce 3+ The absorbed dose is derived from the difference in ceric ion concentration before and after irradiation...

  12. Heparan sulfate biosynthesis

    DEFF Research Database (Denmark)

    Multhaupt, Hinke A B; Couchman, John R

    2012-01-01

    Heparan sulfate is perhaps the most complex polysaccharide known from animals. The basic repeating disaccharide is extensively modified by sulfation and uronic acid epimerization. Despite this, the fine structure of heparan sulfate is remarkably consistent with a particular cell type. This suggests...... that the synthesis of heparan sulfate is tightly controlled. Although genomics has identified the enzymes involved in glycosaminoglycan synthesis in a number of vertebrates and invertebrates, the regulation of the process is not understood. Moreover, the localization of the various enzymes in the Golgi apparatus has......-quality resolution of the distribution of enzymes. The EXT2 protein, which when combined as heterodimers with EXT1 comprises the major polymerase in heparan sulfate synthesis, has been studied in depth. All the data are consistent with a cis-Golgi distribution and provide a starting point to establish whether all...

  13. Integrated reactive absorption process for synthesis of fatty esters.

    Science.gov (United States)

    Kiss, Anton Alexandru; Bildea, Costin Sorin

    2011-01-01

    Reactive separations using green catalysts offer great opportunities for manufacturing fatty esters, involved in specialty chemicals and biodiesel production. Integrating reaction and separation into one unit provides key benefits such as: simplified operation, no waste, reduced capital investment and low operating costs. This work presents a novel heat-integrated reactive absorption process that eliminates all conventional catalyst related operations, efficiently uses the raw materials and equipment, and considerably reduces the energy requirements for biodiesel production--85% lower as compared to the base case. Rigorous simulations based on experimental results were carried out using Aspen Plus and Dynamics. Despite the high degree of integration, the process is well controllable using an efficient control structure proposed in this work. The main results are provided for a plant producing 10 ktpy fatty acid methyl esters from methanol and waste vegetable oil with high free fatty acids content, using sulfated zirconia as solid acid catalyst. Copyright © 2010 Elsevier Ltd. All rights reserved.

  14. Mass spectrometry imaging reveals new biological roles for choline esters and Tyrian purple precursors in muricid molluscs

    Science.gov (United States)

    Rudd, David; Ronci, Maurizio; Johnston, Martin R.; Guinan, Taryn; Voelcker, Nicolas H.; Benkendorff, Kirsten

    2015-01-01

    Despite significant advances in chemical ecology, the biodistribution, temporal changes and ecological function of most marine secondary metabolites remain unknown. One such example is the association between choline esters and Tyrian purple precursors in muricid molluscs. Mass spectrometry imaging (MSI) on nano-structured surfaces has emerged as a sophisticated platform for spatial analysis of low molecular mass metabolites in heterogeneous tissues, ideal for low abundant secondary metabolites. Here we applied desorption-ionisation on porous silicon (DIOS) to examine in situ changes in biodistribution over the reproductive cycle. DIOS-MSI showed muscle-relaxing choline ester murexine to co-localise with tyrindoxyl sulfate in the biosynthetic hypobranchial glands. But during egg-laying, murexine was transferred to the capsule gland, and then to the egg capsules, where chemical ripening resulted in Tyrian purple formation. Murexine was found to tranquilise the larvae and may relax the reproductive tract. This study shows that DIOS-MSI is a powerful tool that can provide new insights into marine chemo-ecology. PMID:26324173

  15. Distribution of Heparan Sulfate Oligosaccharides in Murine Mucopolysaccharidosis Type IIIA

    Directory of Open Access Journals (Sweden)

    Kerryn Mason

    2014-12-01

    Full Text Available Heparan sulfate (HS catabolism begins with endo-degradation of the polysaccharide to smaller HS oligosaccharides, followed by the sequential action of exo-enzymes to reduce these oligosaccharides to monosaccharides and inorganic sulfate. In mucopolysaccharidosis type IIIA (MPS IIIA the exo-enzyme, N-sulfoglucosamine sulfohydrolase, is deficient resulting in an inability to hydrolyze non-reducing end glucosamine N-sulfate esters. Consequently, partially degraded HS oligosaccharides with non-reducing end glucosamine sulfate esters accumulate. We investigated the distribution of these HS oligosaccharides in tissues of a mouse model of MPS IIIA using high performance liquid chromatography electrospray ionization-tandem mass spectrometry. Oligosaccharide levels were compared to total uronic acid (UA, which was used as a measure of total glycosaminoglycan. Ten oligosaccharides, ranging in size from di- to hexasaccharides, were present in all the tissues examined including brain, spleen, lung, heart, liver, kidney and urine. However, the relative levels varied up to 10-fold, suggesting different levels of HS turnover and storage. The relationship between the di- and tetrasaccharides and total UA was tissue specific with spleen and kidney showing a different disaccharide:total UA ratio than the other tissues. The hexasaccharides showed a stronger correlation with total UA in all tissue types suggesting that hexasaccharides may more accurately reflect the storage burden in these tissues.

  16. Lipase-catalysed ester synthesis in solvent-free oil system: is it esterification or transesterification?

    Science.gov (United States)

    Sun, Jingcan; Yu, Bin; Curran, Philip; Liu, Shao-Quan

    2013-12-01

    Ester synthesis was carried out in a solvent-free system of lipase, coconut oil and ethanol or fusel alcohols to ascertain the reaction mechanism. During ester formation, octanoic and decanoic acids increased initially and then decreased gradually, indicating that ester production was a two-step reaction consisting of hydrolysis and esterification, rather than alcoholysis. With ethanol as the alcohol substrate, added butyric acid inhibited ester synthesis. However, when fusel alcohols were used as the alcohol substrate, no significant inhibitory effect by butyric acid was observed. Added octanoic acid did not show any adverse effect on the synthesis of corresponding esters. The results suggest that polarity of the reactants determines lipase activity. This study provides the first evidence on the mechanism of immobilised lipase-catalysed ester synthesis in a solvent-free system involving both hydrolysis and esterification. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Euglena mitochondria and chloroplasts form tyrosine-O-sulfate

    Energy Technology Data Exchange (ETDEWEB)

    Saidha, T.; Hanfstingl, U.; Schiff, J.A. (Brandeis Univ., Waltham, MA (USA))

    1989-04-01

    Mitochondria from light-grown wild-type Euglena gracilis var. bacillaris Cori or dark-grown mutant W{sub 10}BSmL incubated with {sup 35}SO{sub 4}{sup 2{minus}} and ATP, or with {sup 14}C-tyrosine, non-radioactive sulfate and ATP accumulate a labeled compound in the medium. Since this compound shows exact coelectrophoresis with tyrosine-O-sulfate (TOS) at pH 2.0, 5.8 or 8.0., yields sulfate and tyrosine on acid hydrolysis, and treatment with aryl sulfatase from Aerobacter aerogenes yields sulfate and tyrosine but no tyrosine methyl ester, it is identified as TOS. No TOS is found outside purified developing chloroplasts incubated with {sup 35}SO{sub 4}{sup 2{minus}} and ATP, but both chloroplasts and mitochondria form to {sup 35}S externally when incubated with adenosine 3{prime} phosphate 5{prime}phospho({sup 35}S) sulfate (PAP{sup 35}S). Since no tyrosine need be added, tyrosine is provided from endogenous sources. Although TOS is found in the free pool of Euglena cells it cannot be detected in proteins of cells or mucus ruling our sulfation of tyrosine of protein or incorporation of TOS into proteins. The system forming TOS is membrane-bound and may be involved in tyrosine transport.

  18. Enzymatic sulfation of mucus glycoprotein in gastric mucosa

    International Nuclear Information System (INIS)

    Liau, Y.H.; Carter, S.R.; Gwozdzinski, K.; Nadziejko, C.; Slomiany, A.; Slomiany, B.L.

    1986-01-01

    Among the posttranslational modifications that mucus glycoprotein undergo prior to secretion into the gastric lumen is the process of sulfation of the carbohydrate chains. These sulfate groups impart strongly negative charge to nucus glycoprotein and are thought to play a major role in the maintenance of gastric mucosal integrity. The authors report here the presence and some properties of an enzyme involved in the sulfation of gastric mucus glycoprotein. The sulfotransferase activity which catalyzes the transfer of sulfate ester group from PAPS to mucus glycoprotein was located in the detergent extracts of the microsomal fraction of rat gastric mucosa. Optimum enzymatic activity for sulfation of gastric mucin was obtained using 0.5% Triton X-100 and 25mM NaF at a pH of 6.8. ATP, ADP, MgCl 2 and MnCl 2 at concentrations examined were inhibitory. Under optimal conditions, the rate of sulfate incorporation was proportional to the microsomal enzyme protein concentration up to 50μg and remained constant with time of incubation for at least 1h. The apparent Km value of the enzyme for gastric mucus glycoprotein was 8.3 x 10 -6 M. The 35 S-labeled product of the enzyme reaction cochromatographed on Bio-Gel A-50 with gastric mucin, and gave on CsCl equilibrium density gradient centrifugation a band at the density of 1.48 in which the 35 S label coincided with the glycoprotein

  19. Holothurian Fucosylated Chondroitin Sulfate

    Directory of Open Access Journals (Sweden)

    Vitor H. Pomin

    2014-01-01

    Full Text Available Fucosylated chondroitin sulfate (FucCS is a structurally distinct glycosaminoglycan found in sea cucumber species. It has the same backbone composition of alternating 4-linked glucuronic acid and 3-linked N-acetyl galactosamine residues within disaccharide repeating units as regularly found in mammalian chondroitin sulfates. However, FucCS has also sulfated fucosyl branching units 3-O-linked to the acid residues. The sulfation patterns of these branches vary accordingly with holothurian species and account for different biological actions and responses. FucCSs may exhibit anticoagulant, antithrombotic, anti-inflammatory, anticancer, antiviral, and pro-angiogenic activities, besides its beneficial effects in hemodialysis, cellular growth modulation, fibrosis and hyperglycemia. Through an historical overview, this document covers most of the science regarding the holothurian FucCS. Both structural and medical properties of this unique GAG, investigated during the last 25 years, are systematically discussed herein.

  20. Ferrous Sulfate (Iron)

    Science.gov (United States)

    ... are allergic to ferrous sulfate, any other medications tartrazine (a yellow dye in some processed foods and ... in, tightly closed, and out of reach of children. Store it at room temperature and away from ...

  1. Hydrazine Sulfate (PDQ)

    Science.gov (United States)

    ... Recent Public Laws Careers Visitor Information Search Search Home About Cancer Cancer Treatment Complementary & Alternative Medicine (CAM) ... This causes tissues to die and muscle to waste away, and the patient loses weight. Hydrazine sulfate ...

  2. Neutral lipid biosynthesis in engineered Escherichia coli: jojoba oil-like wax esters and fatty acid butyl esters.

    Science.gov (United States)

    Kalscheuer, Rainer; Stöveken, Tim; Luftmann, Heinrich; Malkus, Ursula; Reichelt, Rudolf; Steinbüchel, Alexander

    2006-02-01

    Wax esters are esters of long-chain fatty acids and long-chain fatty alcohols which are of considerable commercial importance and are produced on a scale of 3 million tons per year. The oil from the jojoba plant (Simmondsia chinensis) is the main biological source of wax esters. Although it has a multitude of potential applications, the use of jojoba oil is restricted, due to its high price. In this study, we describe the establishment of heterologous wax ester biosynthesis in a recombinant Escherichia coli strain by coexpression of a fatty alcohol-producing bifunctional acyl-coenzyme A reductase from the jojoba plant and a bacterial wax ester synthase from Acinetobacter baylyi strain ADP1, catalyzing the esterification of fatty alcohols and coenzyme A thioesters of fatty acids. In the presence of oleate, jojoba oil-like wax esters such as palmityl oleate, palmityl palmitoleate, and oleyl oleate were produced, amounting to up to ca. 1% of the cellular dry weight. In addition to wax esters, fatty acid butyl esters were unexpectedly observed in the presence of oleate. The latter could be attributed to solvent residues of 1-butanol present in the medium component, Bacto tryptone. Neutral lipids produced in recombinant E. coli were accumulated as intracytoplasmic inclusions, demonstrating that the formation and structural integrity of bacterial lipid bodies do not require specific structural proteins. This is the first report on substantial biosynthesis and accumulation of neutral lipids in E. coli, which might open new perspectives for the biotechnological production of cheap jojoba oil equivalents from inexpensive resources employing recombinant microorganisms.

  3. Direct Sulfation of Limestone

    DEFF Research Database (Denmark)

    Hu, Guilin; Dam-Johansen, Kim; Wedel, Stig

    2007-01-01

    The direct sulfation of limestone was studied in a laboratory fixed-bed reactor. It is found that the direct sulfation of limestone involves nucleation and crystal grain growth of the solid product (anhydrite). At 823 K and at low-conversions (less than about 0.5 %), the influences of SO2, O-2...... and CO2 on the direct sulfation of limestone corresponds to apparent reaction orders of about 0.2, 0.2 and -0.5, respectively. Water is observed to promote the sulfation reaction and increase the apparent reaction orders of SO2 and O-2. The influence of O-2 at high O-2 concentrations (> about 15...... %) becomes negligible. In the temperature interval from 723 K to 973 K, an apparent activation energy of about 104 kJ/mol is observed for the direct sulfation of limestone. At low temperatures and low conversions, the sulfation process is most likely under mixed control by chemical reaction and solid...

  4. OPTIMASI PRODUKSI METIL ESTER SULFONAT DARI METIL ESTER MINYAK JELANTAH

    Directory of Open Access Journals (Sweden)

    Sri Hidayati

    2012-11-01

    Full Text Available OPTIMATION OF METHYL ESTER SULFONATES PRODUCTION FROM WASTE COOKING METHYL ESTER. An experiment of sulfonation process of methyl ester to produce methyl ester sulfonates (MES was caried out using waste palm methyl ester and sulfuric acid as sulfonating agent with variation of H2SO4 concentration (60% (K1, 70% (K2, dan 80% (K3 and sulfonation time (60 minute (L1, 75 minute (L2 and 90 minute (L3 using factorial on Randomized Complete Design Block. The experiment result showed the best sulfonation condition present in 80% H2SO4 concentration and sulfonation time of 90 minutes.  The best characteristic of MES is produced showed surface tension of 27.35 dyne/cm, emulsion stability of 89.44%, acid value of 17.72 mg KOH/g and interfacial tension of 0.0361 dyne/cm at MES concentration of 2% in 10,000 ppm salinity water. Sebuah penelitian tentang proses produksi metil ester sulfonat menggunakan minyak bekas kelapa sawit dilakukan dengan menggunakan H2SO4 sebagai agen pensulfonasi dengan variasi konsentrasi H2SO4 (60% (K1, 70% (K2, dan 80% (K3 dan lama sulfonasi (60 menit (L1, 75 menit (L2 and 90 menit (L3 dengan menggunakan faktorial dalam Rancangan Kelompok Teracak Lengkap. Hasil penelitian menunjukkan bahwa kondisi proses sulfonasi terbaik terdapat pada konsentrasi H2SO4 80% dan lama reaksi 90 menit. Karakteristik Metil Ester Sulfonat (MES terbaik yang dihasilkan memperlihatkan nilai tegangan permukaan 27,35 dyne/cm, stabilitas emulsi 89,44%, nilai bilangan asam antara 17,72 mg KOH/g dan nilai tegangan antar muka pada konsentrasi MES 2% di dalam air dengan salinitas 10.000 ppm yaitu 0,0361 dyne/cm.

  5. Extraction of beryllium sulfate by a long chain amine

    International Nuclear Information System (INIS)

    Etaix, E.S.

    1968-01-01

    The extraction of sulfuric acid in aqueous solution by a primary amine in benzene solution, 3-9 (diethyl) - 6-amino tri-decane (D.E.T. ) - i.e., with American nomenclature 1-3 (ethyl-pentyl) - 4-ethyl-octyl amine (E.P.O.) - has made it possible to calculate the formation constants of alkyl-ammonium sulfate and acid sulfate. The formula of the beryllium and alkyl-ammonium sulfate complex formed in benzene has next been determined, for various initial acidity of the aqueous solution. Lastly, evidence has been given of negatively charged complexes of beryllium and sulfate in aqueous solution, through the dependence of the aqueous sulfate ions concentration upon beryllium extraction. The formation constant of these anionic complexes has been evaluated. (author) [fr

  6. Micro-SHINE Uranyl Sulfate Irradiations at the Linac

    Energy Technology Data Exchange (ETDEWEB)

    Youker, Amanda J. [Argonne National Lab. (ANL), Argonne, IL (United States); Kalensky, Michael [Argonne National Lab. (ANL), Argonne, IL (United States); Chemerisov, Sergey [Argonne National Lab. (ANL), Argonne, IL (United States); Schneider, John [Argonne National Lab. (ANL), Argonne, IL (United States); Byrnes, James [Argonne National Lab. (ANL), Argonne, IL (United States); Vandegrift, George F. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-08-01

    Peroxide formation due to water radiolysis in a uranyl sulfate solution is a concern for the SHINE Medical Technologies process in which Mo-99 is generated from the fission of dissolved low enriched uranium. To investigate the effects of power density and fission on peroxide formation and uranyl-peroxide precipitation, uranyl sulfate solutions were irradiated using a 50-MeV electron linac as part of the micro-SHINE experimental setup. Results are given for uranyl sulfate solutions with both high and low enriched uranium irradiated at different linac powers.

  7. Syndecan heparan sulfate proteoglycans

    DEFF Research Database (Denmark)

    Gomes, Angélica Maciel; Sinkeviciute, Dovile; Multhaupt, Hinke A.B.

    2016-01-01

    Virtually all animal cells express heparan sulfate proteoglycans on the cell surface and in the extracellular matrix. Syndecans are a major group of transmembrane proteoglycans functioning as receptors that mediate signal transmission from the extracellular microenvironment to the cell. Their hep......Virtually all animal cells express heparan sulfate proteoglycans on the cell surface and in the extracellular matrix. Syndecans are a major group of transmembrane proteoglycans functioning as receptors that mediate signal transmission from the extracellular microenvironment to the cell....... Their heparan sulfate chains, due to their vast structural diversity, interact with a wide array of ligands including potent regulators of adhesion, migration, growth and survival. Frequently, ligands interact with cell surface heparan sulfate in conjunction with high affinity receptors. The consequent...... signaling can therefore be complex, but it is now known that syndecans are capable of independent signaling. This review is divided in two sections, and will first discuss how the assembly of heparan sulfate, the anabolic process, encodes information related to ligand binding and signaling. Second, we...

  8. A possible pathway for rapid growth of sulfate during haze days in China

    Science.gov (United States)

    Li, Guohui; Bei, Naifang; Cao, Junji; Huang, Rujin; Wu, Jiarui; Feng, Tian; Wang, Yichen; Liu, Suixin; Zhang, Qiang; Tie, Xuexi; Molina, Luisa T.

    2017-03-01

    Rapid industrialization and urbanization have caused frequent occurrence of haze in China during wintertime in recent years. The sulfate aerosol is one of the most important components of fine particles (PM2. 5) in the atmosphere, contributing significantly to the haze formation. However, the heterogeneous formation mechanism of sulfate remains poorly characterized. The relationships of the observed sulfate with PM2. 5, iron, and relative humidity in Xi'an, China have been employed to evaluate the mechanism and to develop a parameterization of the sulfate heterogeneous formation involving aerosol water for incorporation into atmospheric chemical transport models. Model simulations with the proposed parameterization can successfully reproduce the observed sulfate rapid growth and diurnal variations in Xi'an and Beijing, China. Reasonable representation of sulfate heterogeneous formation in chemical transport models considerably improves the PM2. 5 simulations, providing the underlying basis for better understanding the haze formation and supporting the design and implementation of emission control strategies.

  9. Hygroscopic properties of aminium sulfate aerosols

    Science.gov (United States)

    Rovelli, Grazia; Miles, Rachael E. H.; Reid, Jonathan P.; Clegg, Simon L.

    2017-03-01

    Alkylaminium sulfates originate from the neutralisation reaction between short-chained amines and sulfuric acid and have been detected in atmospheric aerosol particles. Their physicochemical behaviour is less well characterised than their inorganic equivalent, ammonium sulfate, even though they play a role in atmospheric processes such as the nucleation and growth of new particles and cloud droplet formation. In this work, a comparative evaporation kinetics experimental technique using a cylindrical electrodynamic balance is applied to determine the hygroscopic properties of six short-chained alkylaminium sulfates, specifically mono-, di-, and tri-methylaminium sulfate and mono-, di-, and tri-ethyl aminium sulfate. This approach allows for the retrieval of a water-activity-dependent growth curve in less than 10 s, avoiding the uncertainties that can arise from the volatilisation of semi-volatile components. Measurements are made on particles > 5 µm in radius, avoiding the need to correct equilibrium measurements for droplet-surface curvature with assumed values of the droplet-surface tension. Variations in equilibrium solution droplet composition with varying water activity are reported over the range 0.5 to > 0.98, along with accurate parameterisations of solution density and refractive index. The uncertainties in water activities associated with the hygroscopicity measurements are typically 0.9 and ˜ ±1 % below 0.9, with maximum uncertainties in diameter growth factors of ±0.7 %. Comparison with previously reported measurements show deviation across the entire water activity range.

  10. Bicarbonate sulfate exchange in canalicular rat liver plasma membrane vesicles

    Energy Technology Data Exchange (ETDEWEB)

    Meier, P.J.; Valantinas, J.; Hugentobler, G.; Rahm, I. (University Hospital, Zurich (Switzerland))

    1987-10-01

    The mechanism(s) and driving forces for biliary excretion of sulfate were investigated in canalicular rat liver plasma membrane vesicles (cLPM). Incubation of cLPM vesicles in the presence of an inside-to-outside (in, out) bicarbonate gradient but not pH or out-to-in sodium gradients, stimulated sulfate uptake 10-fold compared with the absence of bicarbonate and approximately 2-fold above sulfate equilibrium (overshoot). Initial rates of this bicarbonate gradient-driven ({sup 35}S)-sulfate uptake were saturable with increasing concentrations of sulfate and could be inhibited by probenecid, N-(4-azido-2-nitrophenyl)-2-aminoethylsulfonate, acetazolamide, furosemide, 4-acetamideo-4{prime}-isothiocyanostilbene-2,2{prime}-disulfonic acid, and 4,4{prime}-diisothiocyanostilbene-2,2{prime}-disulfonic acid (IC{sub 50}, {approximately}40 {mu}M). Cisinhibition of initial bicarbonate gradient-stimulated sulfate uptake and transstimulation of sulfate uptake in the absence of bicarbonate were observed with sulfate, thiosulfate, and oxalate but not with chloride, nitrate, phosphate, acetate, lactate, glutamate, aspartate, cholate, taurocholate, dehydrocholate, taurodehydrocholate, and reduced or oxidized glutathione. These findings indicate the presence of a sulfate (oxalate)-bicarbonate anion exchange system in canalicular rat liver plasma membranes. These findings support the concept that bicarbonate-sensitive transport system might play an important role in bile acid-independent canalicular bile formation.

  11. Bicarbonate sulfate exchange in canalicular rat liver plasma membrane vesicles

    International Nuclear Information System (INIS)

    Meier, P.J.; Valantinas, J.; Hugentobler, G.; Rahm, I.

    1987-01-01

    The mechanism(s) and driving forces for biliary excretion of sulfate were investigated in canalicular rat liver plasma membrane vesicles (cLPM). Incubation of cLPM vesicles in the presence of an inside-to-outside (in, out) bicarbonate gradient but not pH or out-to-in sodium gradients, stimulated sulfate uptake 10-fold compared with the absence of bicarbonate and approximately 2-fold above sulfate equilibrium (overshoot). Initial rates of this bicarbonate gradient-driven [ 35 S]-sulfate uptake were saturable with increasing concentrations of sulfate and could be inhibited by probenecid, N-(4-azido-2-nitrophenyl)-2-aminoethylsulfonate, acetazolamide, furosemide, 4-acetamideo-4'-isothiocyanostilbene-2,2'-disulfonic acid, and 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (IC 50 , ∼40 μM). Cisinhibition of initial bicarbonate gradient-stimulated sulfate uptake and transstimulation of sulfate uptake in the absence of bicarbonate were observed with sulfate, thiosulfate, and oxalate but not with chloride, nitrate, phosphate, acetate, lactate, glutamate, aspartate, cholate, taurocholate, dehydrocholate, taurodehydrocholate, and reduced or oxidized glutathione. These findings indicate the presence of a sulfate (oxalate)-bicarbonate anion exchange system in canalicular rat liver plasma membranes. These findings support the concept that bicarbonate-sensitive transport system might play an important role in bile acid-independent canalicular bile formation

  12. Encapsulating fatty acid esters of bioactive compounds in starch

    Science.gov (United States)

    Lay Ma, Ursula Vanesa

    Interest in the use of many bioactive compounds in foods is growing in large part because of the apparent health benefits of these molecules. However, many of these compounds can be easily degraded during processing, storage, or their passage through the gastrointestinal tract before reaching the target site. In addition, they can be bitter, acrid, or astringent, which may negatively affect the sensory properties of the product. Encapsulation of these molecules may increase their stability during processing, storage, and in the gastrointestinal tract, while providing controlled release properties. The ability of amylose to form inclusion complexes and spherulites while entrapping certain compounds has been suggested as a potential method for encapsulation of certain molecules. However, complex formation and spherulitic crystallization are greatly affected by the type of inclusion molecules, type of starch, and processing conditions. The objectives of the present investigation were to: (a) study the effect of amylose, amylopectin, and intermediate material on spherulite formation and its microstructure; (b) investigate the formation of amylose and high amylose starch inclusion complexes with ascorbyl palmitate, retinyl palmitate, and phytosterol esters; (c) evaluate the ability of spherulites to form in the presence of fatty acid esters and to entrap ascorbyl palmitate, retinyl palmitate, and phytosterol esters; and (d) evaluate the effect of processing conditions on spherulite formation and fatty acid ester entrapment. Higher ratios of linear to branched molecules resulted in the formation of more and rounder spherulites with higher heat stability. In addition to the presence of branches, it appears that spherulitic crystallization is also affected by other factors, such as degree of branching, chain length, and chain length distribution. Amylose and Hylon VII starch formed inclusion complexes with fatty acid esters of ascorbic acid, retinol, or phytosterols

  13. A Comparison Study: The New Extended Shelf Life Isopropyl Ester PMR Technology versus The Traditional Methyl Ester PMR Approach

    Science.gov (United States)

    Alston, William B.; Scheiman, Daniel A.; Sivko, Gloria S.

    2005-01-01

    Polymerization of Monomeric Reactants (PMR) monomer solutions and carbon cloth prepregs of PMR II-50 and VCAP-75 were prepared using both the traditional limited shelf life methanol based PMR approach and a novel extended shelf life isopropanol based PMR approach. The methyl ester and isopropyl ester based PMR monomer solutions and PMR prepregs were aged for up to four years at freezer and room temperatures. The aging products formed were monitored using high pressure liquid chromatography (HPLC). The composite processing flow characteristics and volatile contents of the aged prepregs were also correlated versus room temperature storage time. Composite processing cycles were developed and six ply cloth laminates were fabricated with prepregs after various extended room temperature storage times. The composites were then evaluated for glass transition temperature (Tg), thermal decomposition temperature (Td), initial flexural strength (FS) and modulus (FM), long term (1000 hours at 316 C) thermal oxidative stability (TOS), and retention of FS and FM after 1000 hours aging at 316 C. The results for each ester system were comparable. Freezer storage was found to prevent the formation of aging products for both ester systems. Room temperature storage of the novel isopropyl ester system increased PMR monomer solution and PMR prepreg shelf life by at least an order of magnitude while maintaining composite properties.

  14. Environmental effect of rapeseed oil ethyl ester

    International Nuclear Information System (INIS)

    Makareviciene, V.; Janulis, P.

    2003-01-01

    Exhaust emission tests were conducted on rapeseed oil methyl ester (RME), rapeseed oil ethyl ester (REE) and fossil diesel fuel as well as on their mixtures. Results showed that when considering emissions of nitrogen oxides (NO x ), carbon monoxide (CO) and smoke density, rapeseed oil ethyl ester had less negative effect on the environment in comparison with that of rapeseed oil methyl ester. When fuelled with rapeseed oil ethyl ester, the emissions of NO x showed an increase of 8.3% over those of fossil diesel fuel. When operated on 25-50% bio-ester mixed with fossil diesel fuel, NO x emissions marginally decreased. When fuelled with pure rapeseed oil ethyl ester, HC emissions decreased by 53%, CO emissions by 7.2% and smoke density 72.6% when compared with emissions when fossil diesel fuel was used. Carbon dioxide (CO 2 ) emissions, which cause greenhouse effect, decreased by 782.87 g/kWh when rapeseed oil ethyl ester was used and by 782.26 g/kWh when rapeseed oil methyl ester was used instead of fossil diesel fuel. Rapeseed oil ethyl ester was more rapidly biodegradable in aqua environment when compared with rapeseed oil methyl ester and especially with fossil diesel fuel. During a standard 21 day period, 97.7% of rapeseed oil methyl ester, 98% of rapeseed oil ethyl ester and only 61.3% of fossil diesel fuel were biologically decomposed. (author)

  15. Aluminum Sulfate 18 Hydrate

    Science.gov (United States)

    Young, Jay A.

    2004-01-01

    A chemical laboratory information profile (CLIP) of the chemical, aluminum sulfate 18 hydrate, is presented. The profile lists physical and harmful properties, exposure limits, reactivity risks, and symptoms of major exposure for the benefit of teachers and students using the chemical in the laboratory.

  16. DHEA-sulfate test

    Science.gov (United States)

    ... decrease in DHEA sulfate may be due to: Adrenal gland disorders that produce lower than normal amounts of adrenal ... and the A.D.A.M. Editorial team. Adrenal Gland Disorders Read more Ovarian Cysts Read more NIH MedlinePlus ...

  17. Protein Precipitation Using Ammonium Sulfate

    OpenAIRE

    Wingfield, Paul T.

    2001-01-01

    The basic theory of protein precipitation by addition of ammonium sulfate is presented and the most common applications are listed, Tables are provided for calculating the appropriate amount of ammonium sulfate to add to a particular protein solution.

  18. Synthesis of substituted 2-cyanoarylboronic esters

    DEFF Research Database (Denmark)

    Lysén, Morten; Hansen, Henriette M; Begtrup, Mikael

    2006-01-01

    The synthesis of substituted 2-cyanoarylboronic esters is described via lithiation/in situ trapping of the corresponding methoxy-, trifluoromethyl-, fluoro-, chloro-, and bromobenzonitriles. The crude arylboronic esters were obtained in high yields and purities and with good regioselectivities....

  19. Sulfate transport in toad skin

    DEFF Research Database (Denmark)

    Larsen, Erik Hviid; Simonsen, K

    1988-01-01

    1. In short-circuited toad skin preparations exposed bilaterally to NaCl-Ringer's containing 1 mM SO2(-4), influx of sulfate was larger than efflux showing that the skin is capable of transporting sulfate actively in an inward direction. 2. This active transport was not abolished by substituting ...... (sulfate:bicarbonate exchange) and self-exchange diffusion take place. Irrespective of the mechanism of transport, sulfate is probably transported as a monovalent anion species....

  20. Sulfate metabolism. I. Sulfate uptake and redistribution of acid rain sulfate by edible plants

    International Nuclear Information System (INIS)

    Dallam, R.D.

    1987-01-01

    Sulfur is the major component of polluted air in industrialized societies. Atmospheric sulfur is converted to sulfuric acid through a series of chemical reactions which can eventually reenter many ecosystems. When edible plants are grown in soils containing varying amounts of sulfate, the roots take up and transport inorganic sulfate to the stems and leaves. The sulfate taken up by the roots and the amount transported to the stem and leaves was found to be a function of the concentration of sulfate in the soil. Inorganic sulfate taken up by a corn plant seedling can be rapidly converted to organic sulfate by the root system. Nine days after one of a pair of pea plants was inoculated with artificial acid rain sulfate (dilute H 2 35 SO 4 ) it was found that the sulfate was translocated not only in the inoculated plant, but also to the uninoculated pea plant in the same container. Also, when the leaves of a mature potato plant were inoculated with artificial acid rain sulfate it was found that the sulfate was translocated into the edible potatoes. Fractionation of the potatoes showed that most of the sulfate was water soluble of which 30% was inorganic sulfate and 70% was in the form of organic sulfur. One third of the non-water soluble translocated acid rain sulfate was equally divided between lipid and non-lipid organic sulfur of the potato. 9 references, 2 figures, 5 tables

  1. Synthesis of protons exchange polymeric membranes via co-poly-esters doped with sodium dodecyl sulfate for application in PEM fuel cells; Sintese de membranas polimericas condutoras de protons por imobilizacao de MDs em copoliesteres para aplicacao em PEM-FC

    Energy Technology Data Exchange (ETDEWEB)

    Fiuza, R.A.; Brioude, M.M.; Bresciani, D.; Jose, N.M.; Boaventura, J.S. [Universidade Federal da Bahia (IQ/UFBA), Salvador, BA (Brazil). Inst. de Quimica

    2008-07-01

    Polymers are largely studied for use in PEM-type fuel cell (Proton Exchange membrane, PEMFC). These fuel cells are based on polymer membranes as electrolyte, also called protons conductor. This work developed co-polyesters made electrical conductors by doping with sodium dodecyl sulfate. The copolymers were synthesized from the copolymerization of terephthalic and adipic acids with glycerol. The material was processed in a reactor and shaped by hot pressing, yielding homogeneous and flexible plates, with excellent surface finish. The co-polyesters were analyzed by SEM, FTIR, TG, DSC, and XRD. The thermal analysis showed that the composites were thermally stable up to about 250 deg C. The micrographics revealed the MDS homogeneously dispersed in the polymeric matrix. These copolymers showed electrical conductivity between 10-7 to 10-1 S/cm, suggesting strong potential use in PEM fuel cells. (author)

  2. Mechanical properties and chemical stability of pivalolactone-based poly(ether ester)s

    NARCIS (Netherlands)

    Tijsma, E.J.; Tijsma, E.J.; van der Does, L.; Bantjes, A.; Bantjes, A.; Vulic, I.

    1994-01-01

    The processing, mechanical and chemical properties of poly(ether ester)s, prepared from pivalolactone (PVL), 1,4-butanediol (4G) and dimethyl terephthalate (DMT), were studied. The poly(ether ester)s could easily be processed by injection moulding, owing to their favourable rheological and thermal

  3. The stability of sulfate and hydrated sulfate minerals near ambient conditions and their significance in environmental and planetary sciences

    Science.gov (United States)

    Chou, I-Ming; Seal, Robert R.; Wang, Alian

    2013-01-01

    Sulfate and hydrated sulfate minerals are abundant and ubiquitous on the surface of the Earth and also on other planets and their satellites. The humidity-buffer technique has been applied to study the stability of some of these minerals at 0.1MPa in terms of temperature-relative humidity space on the basis of hydration-dehydration reversal experiments. Updated phase relations in the binary system MgSO"4-H"2O are presented, as an example, to show how reliable thermodynamic data for these minerals could be obtained based on these experimental results and thermodynamic principles. This approach has been applied to sulfate and hydrated sulfate minerals of other metals, including Fe (both ferrous and ferric), Zn, Ni, Co, Cd, and Cu. Metal-sulfate salts play important roles in the cycling of metals and sulfate in terrestrial systems, and the number of phases extends well beyond the simple sulfate salts that have thus far been investigated experimentally. The oxidation of sulfide minerals, particularly pyrite, is a common process that initiates the formation of efflorescent metal-sulfate minerals. Also, the overall abundance of iron-bearing sulfate salts in nature reflects the fact that the weathering of pyrite or pyrrhotite is the ultimate source for many of these phases. Many aspects of their environmental significance are reviewed, particularly in acute effects to aquatic ecosystems related to the dissolution of sulfate salts during rain storms or snow-melt events. Hydrous Mg, Ca, and Fe sulfates were identified on Mars, with wide distribution and very large quantities at many locations, on the basis of spectroscopic observations from orbital remote sensing and surface explorations by rovers. However, many of these findings do not reveal the detailed information on the degree of hydration that is essential for rigorous interpretation of the hydrologic history of Mars. Laboratory experiments on stability fields, reactions pathways, and reaction rates of hydrous

  4. Regioselective Synthesis of Cellulose Ester Homopolymers

    Science.gov (United States)

    Daiqiang Xu; Kristen Voiges; Thomas Elder; Petra Mischnick; Kevin J. Edgar

    2012-01-01

    Regioselective synthesis of cellulose esters is extremely difficult due to the small reactivity differences between cellulose hydroxyl groups, small differences in steric demand between acyl moieties of interest, and the difficulty of attaching and detaching many protecting groups in the presence of cellulose ester moieties without removing the ester groups. Yet the...

  5. ENZYMATIC PRODUCTION OF ETHYL OLEATE ESTER USING A LIPASE FROM CANDIDA ANTARCTICA B

    Directory of Open Access Journals (Sweden)

    N. Sampaio Neta

    2012-05-01

    Full Text Available Lipases are biocatalysts of great importance in different areas, being able to catalyze reactions in aqueous or organic media. Furthermore, these enzymes are capable of using several substrates being stable in a wide range of pH and temperatures. Lipases promote the esterification between fatty acids and ethanol producing oleate esters. The aim of this work is to produce ethyl oleate ester by enzymatic esterification of oleic acid with ethanol. A lipase from Candida antarctica type B was used at a temperature of 55 °C. The reaction was conducted using oleic acid, sodium sulfate anhydrous, lipase and ethanol, with a ratio of oleic acid (0.03 mol or 10 ml, lipase (0.1 mol or 0.01 g, sodium sulfate anhydrous (5 g and ethanol 99 % (100 ml. Several reaction times were studied, namely 48, 72, 96 and 120 hours. Nuclear Magnetic Resonance (1H and 13C and Infrared spectra confirmed the production of ethyl oleate ester for the studied conditions. The highest ethyl oleate production yield was obtained for 96 hours reaction time. Ethyl oleate esters have been reported to possess interesting applications in several industrial fields, such as food, aromatics, cosmetics, detergents, flavors and pharmaceuticals.

  6. Metodologia analítica para a determinação de sulfato em vinhoto When sulfate is present in high concentrations, it acts as an inhibitor in the production of methane (biogas formation in anaerobic biodigestion processes

    Directory of Open Access Journals (Sweden)

    Sílvio Miranda Prada

    1998-06-01

    Full Text Available In this way it is very important to know the sulfate concentration in vinasse samples before to make the biodigestor design. A previous developed and indirect method (Anal. Chim. Acta. 1996, 329, 197, was used to determine sulfate in samples of vinasse, after previous treatments, done in order to eliminate organic matter with hydrogen peroxide 30% and concentrated nitric acid mixture (3:1, under heating. Interferent cationic ions were isolated by using ion exchange columns. The results obtained for some samples from Araraquara and Penápolis are here presented. The phosphate concentration was also determined.

  7. Catalytic Ester to Stannane Functional Group Interconversion via Decarbonylative Cross-Coupling of Methyl Esters

    KAUST Repository

    Yue, Huifeng

    2018-01-03

    An unprecedented conversion of methyl esters to stannanes was realized, providing access to a series of arylstannanes via nickel catalysis. Various common esters including ethyl, cyclohexyl, benzyl, and phenyl esters can undergo the newly developed decarbonylative stannylation reaction. The reaction shows broad substrate scope, can differentiate between different types of esters, and if applied in consecutive fashion, allows the transformation of methyl esters into aryl fluorides or biaryls via fluororination or arylation.

  8. Sulfate and nitrate levels in aqueous, atmospheric aerosols

    International Nuclear Information System (INIS)

    Peterson, T.W.; Seinfeld, J.H.

    1979-01-01

    The formation of sulfates and nitrates in marine aerosol particles is investigated. A simulation of the growth and chemical reactions of an aerosol particle composed initially of an equilibrium mixture of NaCl and MgCl 2 and exposed to SO 2 , NO, NO 2 , NH 3 and H 2 SO 4 vapor is used to predict the relative compositions of sulfates, nitrates and ammonium, assuming gas-phase sulfur dioxide oxidation and liquid-phase nitrate formation. Results indicate an increase in nitrate concentration and a decrease in sulfate and ammonium concentrations with increasing particle radius and a near-stoichiometric ratio of nitrate and sulfate to ammonium. The noted deviations of this ratio from those observed experimentally are considered to indicate the relative importances of liquid-phase sulfur dioxide oxidation at various locations

  9. Decomposition and hydrocarbon growth processes for esters in non-premixed flames.

    Science.gov (United States)

    Schwartz, William R; McEnally, Charles S; Pfefferle, Lisa D

    2006-06-01

    Biomass fuels are a promising renewable energy source, and so, the mechanisms that may produce toxic oxygenated byproducts and aromatic hydrocarbons from oxygenated hydrocarbons are of interest. Esters have the form R-(C=O)-O-R' and are components of biodiesel fuels. The five specific esters studied here are isomers of C5H10O2. The experiments were performed in atmospheric pressure coflowing methane/air non-premixed flames. A series of flames were generated by separately doping the fuel mixture with 5,000 ppm of each ester. This concentration is sufficiently large to produce measurable changes in intermediate hydrocarbon concentrations, yet small enough to not disturb the overall flame structure. Since the overall structure is not perturbed, the measured changes in the intermediate hydrocarbons can be directly attributed to the reactions of the esters. Analysis of these changes reveals that unimolecular six-centered dissociation is the primary decomposition pathway for the three esters with molecular arrangements capable of undergoing that mechanism. The remaining two esters exhibited decomposition rates and products that are consistent with simple fission as the dominant decomposition mechanism, though we do not exclude other pathways from playing a significant role in their decomposition. All of the esters produce aromatic hydrocarbons at higher rates than the undoped fuel, and the molecular arrangement of the ester isomers plays a role in the degree of aromatic formation. Isomer variations also influence the type and quantity of toxic oxygenates that are produced in the flames.

  10. Dissolution of sulfate scales

    Energy Technology Data Exchange (ETDEWEB)

    Hen, J.

    1991-11-26

    This patent describes a composition for the removal of sulfate scale from surfaces. It comprises: an aqueous solution of about 0.1 to 1.0 molar concentration of an aminopolycarboxylic acid (APCA) containing 1 to 4 amino groups or a salt thereof, and about 0.1 to 1.0 molar concentration of a second component which is diethylenetriaminepenta (methylenephosphonic acid) (DTPMP) or a salt thereof, or aminotri (methylenephosphonic acid) (ATMP) or a salt thereof as an internal phase enveloped by a hydrocarbon membrane phase which is itself emulsified in an external aqueous phase, the hydrocarbon membrane phase continuing a complexing agent weaker for the cations of the sulfate scale than the APCA and DTPMP or ATMP, any complexing agent for the cations in the external aqueous phase being weaker than that in the hydrocarbon membrane phase.

  11. Damage modelling in concrete subject to sulfate attack

    Directory of Open Access Journals (Sweden)

    N. Cefis

    2014-07-01

    Full Text Available In this paper, we consider the mechanical effect of the sulfate attack on concrete. The durability analysis of concrete structures in contact to external sulfate solutions requires the definition of a proper diffusion-reaction model, for the computation of the varying sulfate concentration and of the consequent ettringite formation, coupled to a mechanical model for the prediction of swelling and material degradation. In this work, we make use of a two-ions formulation of the reactive-diffusion problem and we propose a bi-phase chemo-elastic damage model aimed to simulate the mechanical response of concrete and apt to be used in structural analyses.

  12. Structure of the 'corallinans'--sulfated xylogalactans from Corallina officinalis.

    Science.gov (United States)

    Cases, M R; Stortz, C A; Cerezo, A S

    1994-04-01

    The structure of the main polysaccharides extracted from the red seaweed Corallina officinalis was characterized by methylation, desulfation-methylation, and ethylation analysis. The backbone has an alternating-->4)-alpha-L-Gal-(1-->3)-beta-D-Gal-(1-->structure. The C6 position of 3-linked units is substituted mainly by beta-D-xylosyl side stubs but also by sulfate ester groups and minor amounts of 4-O-methylgalactosyl side stubs. Positions C2 and C3 of 4-linked units also carry sulfate or methoxyl as substituents, but never both together in the same unit. Minor fractions modulate this structure with other irregularities, such as higher branching or, possibly, unusual (1-->2) or (1-->6) linkages.

  13. Sulfation of chondroitin. Specificity, degree of sulfation, and detergent effects with 4-sulfating and 6-sulfating microsomal systems

    International Nuclear Information System (INIS)

    Sugumaran, G.; Silbert, J.E.

    1988-01-01

    Microsomal preparations from chondroitin 6-sulfate-producing chick embryo epiphyseal cartilage, and from chondroitin 4-sulfate-producing mouse mastocytoma cells, were incubated with UDP-[14C]glucuronic acid and UDP-N-acetylgalactosamine to form non-sulfated proteo[14C]chondroitin. Aliquots of the incubations were then incubated with 3'-phosphoadenylylphosphosulfate (PAPS) in the presence or absence of various detergents. In the absence of detergents, there was good sulfation of this endogenous proteo[14C]chondroitin by the original microsomes from both sources. Detergents, with the exception of Triton X-100, markedly inhibited sulfation in the mast cell system but not in the chick cartilage system. These results indicate that sulfation and polymerization are closely linked on cell membranes and that in some cases this organization can be disrupted by detergents. When aliquots of the original incubation were heat inactivated, and then reincubated with new microsomes from chick cartilage and/or mouse mastocytoma cells plus PAPS, there was no significant sulfation of this exogenous proteo[14C] chondroitin with either system unless Triton X-100 was added. Sulfation of exogenous chondroitin and chondroitin hexasaccharide was compared with sulfation of endogenous and exogenous proteo[14C]chondroitin. Sulfate incorporation into hexasaccharide and chondroitin decreased as their concentrations (based on uronic acid) approached that of the proteo[14C]chondroitin. At the same time, the degree of sulfation in percent of substituted hexosamine increased. However, the degree of sulfation did not reach that of the endogenous proteo[14C]chondroitin. Hexasaccharide and chondroitin sulfation were stimulated by the presence of Triton X-100. However, in contrast to the exogenous proteo[14C]chondroitin, there was some sulfation of hexasaccharide and chondroitin in the absence of this detergent

  14. Off limits: sulfate below the sulfate-methane transition

    Science.gov (United States)

    Brunner, Benjamin; Arnold, Gail; Røy, Hans; Müller, Inigo; Jørgensen, Bo

    2016-07-01

    One of the most intriguing recent discoveries in biogeochemistry is the ubiquity of cryptic sulfur cycling. From subglacial lakes to marine oxygen minimum zones, and in marine sediments, cryptic sulfur cycling - the simultaneous sulfate consumption and production - has been observed. Though this process does not leave an imprint in the sulfur budget of the ambient environment - thus the term cryptic - it may have a massive impact on other element cycles and fundamentally change our understanding of biogeochemical processes in the subsurface. Classically, the sulfate-methane transition (SMT) in marine sediments is considered to be the boundary that delimits sulfate reduction from methanogenesis as the predominant terminal pathway of organic matter mineralization. Two sediment cores from Aarhus Bay, Denmark reveal the constant presence of sulfate (generally 0.1 to 0.2 mM) below the SMT. The sulfur and oxygen isotope signature of this deep sulfate (34S = 18.9‰, 18O = 7.7‰) was close to the isotope signature of bottom-seawater collected from the sampling site (34S = 19.8‰, 18O = 7.3‰). In one of the cores, oxygen isotope values of sulfate at the transition from the base of the SMT to the deep sulfate pool (18O = 4.5‰ to 6.8‰) were distinctly lighter than the deep sulfate pool. Our findings are consistent with a scenario where sulfate enriched in 34S and 18O is removed at the base of the SMT and replaced with isotopically light sulfate below. Here, we explore scenarios that explain this observation, ranging from sampling artifacts, such as contamination with seawater or auto-oxidation of sulfide - to the potential of sulfate generation in a section of the sediment column where sulfate is expected to be absent which enables reductive sulfur cycling, creating the conditions under which sulfate respiration can persist in the methanic zone.

  15. An electrochemical and spectroscopic investigation of the corrosion inhibitor nonylphenylethoxy phosphate ester and of the films formed on 316L stainless steel in acidic solutions

    Science.gov (United States)

    Chou, Peter Hsu-Jen

    In-situ surface-enhanced Raman spectroscopy (SERS) and electrochemical polarization were applied to study nonylphenylethoxy phosphate ester, an effective corrosion inhibitor for pipeline steels in carbon-dioxide-saturated formation brine. Comparison of results among the phosphate ester, a nonylphenyl ethoxylated alcohol (Nonoxynol-9), and the sulfate ester---molecules that are essentially identical except for the headgroup---indicates that the effectiveness of the first as a corrosion inhibitor is crucially dependent upon the phosphate headgroup. Its effectiveness is attributed predominantly to the ability to complex with the surface, and not to its electrostatic interaction with the surface. Polarization curves obtained in brine containing the phosphate monoester or diester, separated from the as-received mixture, indicate that the monoester is superior. While SERS indicates that the ethoxylates of the phosphate ester interact with the steel surface, they, by themselves, are not sufficient to anchor the molecule. Spectral features assigned to the phenyl ring suggest that it does not interact significantly with the steel surface. SERS demonstrates that Cl- adsorption correlates with a decrease in phosphate ester adsorption and this occurs in the range of potentials where pitting would be expected according to the polarization curve. SERS has also been used to investigate the films that form on the surface of 316L stainless steel in a number of acidic solutions at room temperature---0.75 M HCl, 0.75 M HBr, 0.867 M HClO4, 0.75 M H2SO4 , and 0.75 M NaCl + 10-3 M HCl (pH 3). Two surface species characterized by SER peaks at 395 and 460 cm-1 form in all solutions; the relative intensity of the peaks depends on pH. The SER spectra of the films do not correlate with any cited reference spectrum of the oxide, hydroxide, or oxyhydroxide of iron, chromium, nickel, or molybdenum. The presence of a component giving rise to a peak at ≈214 cm-1 correlates with the absence of

  16. Transformation of Unsaturated Fatty Acids/Esters to Corresponding Keto Fatty Acids/Esters by Aerobic Oxidation with Pd(II)/Lewis Acid Catalyst.

    Science.gov (United States)

    Senan, Ahmed M; Zhang, Sicheng; Zeng, Miao; Chen, Zhuqi; Yin, Guochuan

    2017-08-16

    Utilization of renewable biomass to partly replace the fossil resources in industrial applications has attracted attention due to the limited fossil feedstock with the increased environmental concerns. This work introduced a modified Wacker-type oxidation for transformation of unsaturated fatty acids/esters to the corresponding keto fatty acids/esters, in which Cu 2+ cation was replaced with common nonredox metal ions, that is, a novel Pd(II)/Lewis acid (LA) catalyst. It was found that adding nonredox metal ions can effectively promote Pd(II)-catalyzed oxidation of unsaturated fatty acids/esters to the corresponding keto fatty acids/esters, even much better than Cu 2+ , and the promotional effect is highly dependent on the Lewis acidity of added nonredox metal ions. The improved catalytic efficiency is attributed to the formation of heterobimetallic Pd(II)/LA species, and the oxidation mechanism of this Pd(II)/LA catalyst is also briefly discussed.

  17. Enhanced sulfate reduction with acidogenic sulfate-reducing bacteria

    International Nuclear Information System (INIS)

    Wang Aijie; Ren Nanqi; Wang Xu; Lee Duujong

    2008-01-01

    Sulfate reduction in a continuous flow, acidogenic reactor using molasses wastewater as the carbon source was studied at varying chemical oxygen demand/sulfate (COD/SO 4 2- ) ratios. At a critical COD/SO 4 2- ratio of 2.7, neither COD nor sulfate were in excess for extra production of ethanol or acetate in the reactor. An acetic-type microbial metabolism was established with sulfate-reducing bacteria (SRB) significantly consuming hydrogen and volatile fatty acids produced by acidogenic bacteria and hydrogen producing acetogens in degrading COD, thereby yielding sulfate removal rate >94.6%. A low critical COD/SO 4 2- ratio of 1.6 was also observed with the enriched ASRB population in reactor which overcomes the barrier to the treatment capability of sulfate-laden wastewater treatment with limited COD supply

  18. FEL induced molecular operation on cultured fibroblast and cholesterol ester

    International Nuclear Information System (INIS)

    Awazu, Kunio; Ogino, Seiji; Nishimura, Eiichi; Tomimasu, Takio; Yasumoto, Masato.

    1997-01-01

    Free Electron Lasers can be used to molecular operation such as the delivery of a number of molecules into cells or the separation of cholesterol ester. First, cultured NIH3T3 cells are exposed to high-intensity short pulse Free Electron Laser (FEL). The FEL is tuned to an absorption maximum wavelength, 6.1 μm, which was measured by microscopic FTIR. A fluorescence dye in the cell suspension is more absorbed into the cell with the FEL exposure due to the FEL-induced mechanical stress to the cell membrane. A quantitative fluorescence microscopy is used to determine the efficiency of delivery. Second, as a compound in a lipid cell, cholesterol ester was exposed to 5.75 μm FEL. FTIR measurement was done to evaluate the modification of the cholesterol ester. The result showed that the fluorescence intensity of sample cells were higher than that of control cells, and there was significant difference between the control and the sample group. Blebbing and the colony formation of the cells were observed for cells with mechanical stress. As for the cholesterol ester, it can be modified by the FEL irradiation. These results showed that FEL can be used as a molecular operational tool by photo-chemical and photo-mechanical interaction. (author)

  19. Plagioclase dissolution during CO₂-SO₂ cosequestration: effects of sulfate.

    Science.gov (United States)

    Min, Yujia; Kubicki, James D; Jun, Young-Shin

    2015-02-03

    Geologic CO2 sequestration (GCS) is one of the most promising methods to mitigate the adverse impacts of global climate change. The performance of GCS can be affected by mineral dissolution and precipitation induced by injected CO2. Cosequestration with acidic gas such as SO2 can reduce the high cost of GCS, but it will increase the sulfate's concentration in GCS sites, where sulfate can potentially affect plagioclase dissolution/precipitation. This work investigated the effects of 0.05 M sulfate on plagioclase (anorthite) dissolution and subsequent mineral precipitation at 90 °C, 100 atm CO2, and 1 M NaCl, conditions relevant to GCS sites. The adsorption of sulfate on anorthite, a Ca-rich plagioclase, was examined using attenuated total reflectance Fourier-transform infrared spectroscopy and then simulated using density functional theory calculations. We found that the dissolution rate of anorthite was enhanced by a factor of 1.36 by the formation of inner-sphere monodentate complexes between sulfate and the aluminum sites on anorthite surfaces. However, this effect was almost completely suppressed in the presence of 0.01 M oxalate, an organic ligand that can exist in GCS sites. Interestingly, sulfate also inhibited the formation of secondary mineral precipitation through the formation of aluminum-sulfate complexes in the aqueous phase. This work, for the first time, reports the surface complexation between sulfate and plagioclase that can occur in GCS sites. The results provide new insights for obtaining scientific guidelines for the proper amount of SO2 coinjection and finally for evaluating the economic efficiency and environmental safety of GCS operations.

  20. Fast and efficient green synthesis of thiosulfonate S-esters by microwave-supported permanganate oxidation of symmetrical disulfides

    DEFF Research Database (Denmark)

    Thi, Luu Thi Xuan; Thi Nguyen, Thao-Tran; Le, Thach Ngoc

    2015-01-01

    Potassium permanganate absorbed on copper(II) sulfate pentahydrate has been found to be an efficient, inexpensive, and green oxidation agent for the synthesis of “symmetrical” thiosulfonate S-esters by oxidation of the corresponding symmetrical disulfides. The oxidation reactions were carried out...... under solvent-free reaction conditions within 15 min under the influence of microwave irradiation, as well as (for comparison) supported by conventional heating, to afford yields of the thiosulfonate S-esters in the range of 60–83%. The oxidation reaction appears to proceed (at least partly) via...

  1. 2-Amino-4-hydroxyethylaminoanisole sulfate

    DEFF Research Database (Denmark)

    Madsen, Jakob T; Andersen, Klaus E

    2016-01-01

    positive patch test reactions to the coupler 2-amino-4-hydroxyethylaminoanisole sulfate 2% pet. from 2005 to 2014. METHODS: Patch test results from the Allergen Bank database for eczema patients patch tested with 2-amino-4-hydroxyethylaminoanisole sulfate 2% pet. from 2005 to 2014 were reviewed. RESULTS......: A total of 902 dermatitis patients (154 from the dermatology department and 748 from 65 practices) were patch tested with amino-4-hydroxyethylaminoanisole sulfate 2% pet. from 2005 to 2014. Thirteen (1.4%) patients had a positive patch test reaction. Our results do not indicate irritant reactions....... CONCLUSIONS: 2-Amino-4-hydroxyethylaminoanisole sulfate is a new but rare contact allergen....

  2. Preparation and characterization of sulfated zirconia acid catalysts for application in the esterification of cottonseed oil; Preparacao e caracterizacao de catalisadores acidos de zirconia sulfatada para aplicacao na esterificacao do oleo de algodao

    Energy Technology Data Exchange (ETDEWEB)

    Silva, F. N.; Moura, T. F. B.; Silva, A.S.; Costa, A.C.F.M., E-mail: fnilson.s@hotmail.com [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Pos-graduacao em Engenharia de Materiais; Pallone, E.M.J.A. [Universidade de Sao Paulo (USP), Pirassununga, SP (Brazil). Dept. de Ciencias Basicas

    2017-07-15

    This work aimed to produce zirconia by combustion synthesis, to analyze the structure and morphology comparatively with a commercial monoclinic ZrO{sub 2} , as well as, to investigate the sulfation, aiming to obtain acid catalysts for its use in the esterification of cotton oil for biodiesel. The samples were characterized by X-ray diffraction, scanning electron microscopy (SEM), specific surface area by BET method, infrared spectroscopy (FTIR), thermal analysis (TG/DrTG/DTA), granulometric distribution, pH and chromatography. The synthesized sample evidenced the formation of the monoclinic phase with traces of the orthorhombic phase, while in the commercial sample only the monoclinic phase was observed. In the sulfation process, traces of the tetragonal phase, typical of sulfated zirconia, were observed with the presence of the monoclinic phase in the two samples. With the impregnation of the sulfate ion on the surface of the samples, an increase in the particle size was observed, as seen in the characterization of BET, granulometric distribution and SEM, which also indicated a homogeneous morphology consisting of fine particles of approximately spherical shape for both samples. The chromatography indicated conversion of 65.5 and 91.8% in methyl esters to the synthesized and commercial SO{sub 4} {sup 2-}/ZrO{sub 2} , respectively. The results indicated that the sulfation increased the acidity, which was evidenced by the decrease in the pH, ranging from 5.12 to 2.65, which contributed significantly to the increase of the conversion, indicating that the SO{sub 4} {sup 2-}/ZrO{sub 2} is a promising catalyst in the esterification. (author)

  3. Lipase-Catalyzed Synthesis of Sugar Esters in Honey and Agave Syrup

    Directory of Open Access Journals (Sweden)

    Sascha Siebenhaller

    2018-02-01

    Full Text Available Honey and agave syrup are high quality natural products and consist of more than 80% sugars. They are used as sweeteners, and are ingredients of cosmetics or medical ointments. Furthermore, both have low water content, are often liquid at room temperature and resemble some known sugar-based deep eutectic solvents (DES. Since it has been shown that it is possible to synthesize sugar esters in these DESs, in the current work honey or, as vegan alternative, agave syrup are used simultaneously as solvent and substrate for the enzymatic sugar ester production. For this purpose, important characteristics of the herein used honey and agave syrup were determined and compared with other available types. Subsequently, an enzymatic transesterification of four fatty acid vinyl esters was accomplished in ordinary honey and agave syrup. Notwithstanding of the high water content for transesterification reactions of the solvent, the successful sugar ester formation was proved by thin-layer chromatography (TLC and compared to a sugar ester which was synthesized in a conventional DES. For a clear verification of the sugar esters, mass determinations by ESI-Q-ToF experiments and a NMR analysis were done. These environmentally friendly produced sugar esters have the potential to be used in cosmetics or pharmaceuticals, or to enhance their effectiveness.

  4. Lipase-Catalyzed Synthesis of Sugar Esters in Honey and Agave Syrup

    Science.gov (United States)

    Siebenhaller, Sascha; Gentes, Julian; Infantes, Alba; Muhle-Goll, Claudia; Kirschhöfer, Frank; Brenner-Weiß, Gerald; Ochsenreither, Katrin; Syldatk, Christoph

    2018-01-01

    Honey and agave syrup are high quality natural products and consist of more than 80% sugars. They are used as sweeteners, and are ingredients of cosmetics or medical ointments. Furthermore, both have low water content, are often liquid at room temperature and resemble some known sugar-based deep eutectic solvents (DES). Since it has been shown that it is possible to synthesize sugar esters in these DESs, in the current work honey or, as vegan alternative, agave syrup are used simultaneously as solvent and substrate for the enzymatic sugar ester production. For this purpose, important characteristics of the herein used honey and agave syrup were determined and compared with other available types. Subsequently, an enzymatic transesterification of four fatty acid vinyl esters was accomplished in ordinary honey and agave syrup. Notwithstanding of the high water content for transesterification reactions of the solvent, the successful sugar ester formation was proved by thin-layer chromatography (TLC) and compared to a sugar ester which was synthesized in a conventional DES. For a clear verification of the sugar esters, mass determinations by ESI-Q-ToF experiments and a NMR analysis were done. These environmentally friendly produced sugar esters have the potential to be used in cosmetics or pharmaceuticals, or to enhance their effectiveness. PMID:29487847

  5. Lipase-Catalyzed Synthesis of Sugar Esters in Honey and Agave Syrup.

    Science.gov (United States)

    Siebenhaller, Sascha; Gentes, Julian; Infantes, Alba; Muhle-Goll, Claudia; Kirschhöfer, Frank; Brenner-Weiß, Gerald; Ochsenreither, Katrin; Syldatk, Christoph

    2018-01-01

    Honey and agave syrup are high quality natural products and consist of more than 80% sugars. They are used as sweeteners, and are ingredients of cosmetics or medical ointments. Furthermore, both have low water content, are often liquid at room temperature and resemble some known sugar-based deep eutectic solvents (DES). Since it has been shown that it is possible to synthesize sugar esters in these DESs, in the current work honey or, as vegan alternative, agave syrup are used simultaneously as solvent and substrate for the enzymatic sugar ester production. For this purpose, important characteristics of the herein used honey and agave syrup were determined and compared with other available types. Subsequently, an enzymatic transesterification of four fatty acid vinyl esters was accomplished in ordinary honey and agave syrup. Notwithstanding of the high water content for transesterification reactions of the solvent, the successful sugar ester formation was proved by thin-layer chromatography (TLC) and compared to a sugar ester which was synthesized in a conventional DES. For a clear verification of the sugar esters, mass determinations by ESI-Q-ToF experiments and a NMR analysis were done. These environmentally friendly produced sugar esters have the potential to be used in cosmetics or pharmaceuticals, or to enhance their effectiveness.

  6. Ester Tuiksoo. Proua Suhkru kibedad päevad / Ester Tuiksoo ; interv. Piret Tali

    Index Scriptorium Estoniae

    Tuiksoo, Ester, 1965-

    2005-01-01

    Põllumajandusminister Ester Tuiksoo, kellel peagi täitub ministri ametis aasta Euroopa Liidu suhkrutrahvist, maaettevõtlusest, põllumajandusest, Euroopa Liidu toetustest, ministri elu- ja teenistuskäigust. Lisa: Ester Tuiksoo

  7. Method of making a cyanate ester foam

    Science.gov (United States)

    Celina, Mathias C.; Giron, Nicholas Henry

    2014-08-05

    A cyanate ester resin mixture with at least one cyanate ester resin, an isocyanate foaming resin, other co-curatives such as polyol or epoxy compounds, a surfactant, and a catalyst/water can react to form a foaming resin that can be cured at a temperature greater than 50.degree. C. to form a cyanate ester foam. The cyanate ester foam can be heated to a temperature greater than 400.degree. C. in a non-oxidative atmosphere to provide a carbonaceous char foam.

  8. Steroidal esters from Ferula sinkiangensis.

    Science.gov (United States)

    Li, Guangzhi; Li, Xiaojin; Cao, Li; Shen, Liangang; Zhu, Jun; Zhang, Jing; Wang, Junchi; Zhang, Lijing; Si, Jianyong

    2014-09-01

    Two new steroidal esters with an unusual framework, Sinkiangenorin A and B, a new organic acid glycoside, Sinkiangenorin C, and four known lignin compounds were isolated from the seeds of Ferula sinkiangensis. The structures of these compounds were established by spectroscopic analysis and single-crystal X-ray diffraction. All of the isolated compounds were tested against Hela, K562 and AGS human cancer cell lines. Sinkiangenorin C showed cytotoxic activity against AGS cells with an IC50 of 36.9 μM. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Influence of ammonium salts on the lipase/esterase activity assay using p-nitrophenyl esters as substrates.

    Science.gov (United States)

    De Yan, Hong; Zhang, Yin Jun; Liu, Hong Cai; Zheng, Jian Yong; Wang, Zhao

    2013-01-01

    p-Nitrophenyl esters with a short-chain carboxylic group, such as p-nitrophenyl acetate (p-NPA) and p-nitrophenyl butyrate (p-NPB), could be effectively hydrolyzed by ammonium salts. p-Nitrophenyl esters were usually used as substrates to assay the lipase/esterase activity. Ammonium sulfate precipitation was often used to purify proteins, and some ammonium salts were usually used as nitrogen sources or inorganic salts for the lipase/esterase production. To study the effect of ammonium salts on the assay of the lipase/esterase activity, the contributing factors of hydrolysis of p-NPA/p-NPB catalyzed by ammonium salts were investigated. The lipase activities were compared in the presence and absence of ammonium sulfate. The hydrolysis reaction could be catalyzed under neutral and alkaline circumstances. The hydrolysis rate increased with the increase in the reaction temperature or the concentration of ammonium ion. When p-NPA was employed as the substrate for the analysis of the lipase/esterase activity, the effect of ammonium sulfate on the analysis could be neutralized by setting a control when the concentration of ammonium sulfate was less than 40% saturation. However, when the concentration of ammonium sulfate increased from 40% to 100% saturation, the enzyme activities decreased about 13-40%, which could not be ignored for accurate analysis of the enzyme activity. © 2013 International Union of Biochemistry and Molecular Biology, Inc.

  10. Protein Precipitation Using Ammonium Sulfate.

    Science.gov (United States)

    2016-04-01

    The basic theory of protein precipitation by addition of ammonium sulfate is presented, and the most common applications are listed. Tables are provided for calculating the appropriate amount of ammonium sulfate to add to a particular protein solution. Copyright © 2016 John Wiley & Sons, Inc.

  11. Environmentally friendly efficient one-pot esterification of cyclohexane with CuO-promoted sulfated zirconia.

    Science.gov (United States)

    Wang, Jingjing; Ma, Hongzhu; Wang, Bo

    2008-09-15

    The production of dibutyl phthalate directly from oxidation and esterification of cyclohexane, catalyzed by CuO-modified sulfated zirconia (SZCu) by one-pot under mild condition, was studied. The esterification reaction process was monitored by UV-vis spectra and the distribution of the products was analyzed by gas chromatograph-mass spectrometry (GC-MS). The result revealed that the SZCu catalyst was efficient in the direct oxidation and esterification of cyclohexane to ester. The selectivity for ester (dibutyl phthalate) can reach up to 72.2 wt.%, and the yield of ester was 29.5 wt.%. The esterification reaction, that offers several advantages such as usage of environmental friendly oxidant, simple work-up procedure, no-solvent conditions, short reaction times, easy recovery and reusability of the catalyst, is necessary for chemosynthesis industry from the environment standpoint. The regeneration property of SZCu was also tested in this work.

  12. Off limits: sulfate below the sulfate-methane transition

    Directory of Open Access Journals (Sweden)

    Benjamin Brunner

    2016-07-01

    Full Text Available One of the most intriguing recent discoveries in biogeochemistry is the ubiquity of cryptic sulfur cycling. From subglacial lakes to marine oxygen minimum zones, and in marine sediments, cryptic sulfur cycling – the simultaneous sulfate consumption and production – has been observed. Though this process does not leave an imprint in the sulfur budget of the ambient environment – thus the term cryptic – it may have a massive impact on other element cycles and fundamentally change our understanding of biogeochemical processes in the subsurface.Classically, the sulfate-methane transition (SMT in marine sediments is considered to be the boundary that delimits sulfate reduction from methanogenesis as the predominant terminal pathway of organic matter mineralization. Two sediment cores from Aarhus Bay, Denmark reveal the constant presence of sulfate (generally 0.1 to 0.2 mM below the SMT. The sulfur and oxygen isotope signature of this deep sulfate (34S = 18.9‰, 18O = 7.7‰ was close to the isotope signature of bottom-seawater collected from the sampling site (34S = 19.8‰, 18O = 7.3‰. In one of the cores, oxygen isotope values of sulfate at the transition from the base of the SMT to the deep sulfate pool (18O = 4.5‰ to 6.8‰ were distinctly lighter than the deep sulfate pool.Our findings are consistent with a scenario where sulfate enriched in 34S and 18O is removed at the base of the SMT and replaced with isotopically light sulfate below. Here, we explore scenarios that explain this observation, ranging from sampling artifacts, such as contamination with seawater or auto-oxidation of sulfide – to the potential of sulfate generation in a section of the sediment column where sulfate is expected to be absent which enables reductive sulfur cycling, creating the conditions under which sulfate respiration can persist in the methanic zone.

  13. Novel Synthesis of Phytosterol Ester from Soybean Sterol and Acetic Anhydride.

    Science.gov (United States)

    Yang, Fuming; Oyeyinka, Samson A; Ma, Ying

    2016-07-01

    Phytosterols are important bioactive compounds which have several health benefits including reduction of serum cholesterol and preventing cardiovascular diseases. The most widely used method in the synthesis of its ester analogous form is the use of catalysts and solvents. These methods have been found to present some safety and health concern. In this paper, an alternative method of synthesizing phytosterol ester from soybean sterol and acetic anhydride was investigated. Process parameters such as mole ratio, temperature and time were optimized. The structure and physicochemical properties of phytosterol acetic ester were analyzed. By the use of gas chromatography, the mole ratio of soybean sterol and acetic anhydride needed for optimum esterification rate of 99.4% was 1:1 at 135 °C for 1.5 h. FTIR spectra confirmed the formation of phytosterol ester with strong absorption peaks at 1732 and 1250 cm(-1) , which corresponds to the stretching vibration of C=O and C-O-C, respectively. These peaks could be attributed to the formation of ester links which resulted from the reaction between the hydroxyl group of soybean sterol and the carbonyl group of acetic anhydride. This paper provides a better alternative to the synthesis of phytosterol ester without catalyst and solvent residues, which may have potential application in the food, health-care food, and pharmaceutical industries. © 2016 Institute of Food Technologists®

  14. Sulfation of von Willebrand factor

    International Nuclear Information System (INIS)

    Carew, J.A.; Browning, P.J.; Lynch, D.C.

    1990-01-01

    von Willebrand factor (vWF) is a multimeric adhesive glycoprotein essential for normal hemostasis. We have discovered that cultured human umbilical vein endothelial cells incorporate inorganic sulfate into vWF. Following immunoisolation and analysis by polyacrylamide or agarose gel electrophoresis, metabolically labeled vWF was found to have incorporated [35S]-sulfate into all secreted multimer species. The time course of incorporation shows that sulfation occurs late in the biosynthesis of vWF, near the point at which multimerization occurs. Quantitative analysis suggests the presence, on average, of one molecule of sulfate per mature vWF subunit. Virtually all the detectable sulfate is released from the mature vWF subunit by treatment with endoglycosidases that remove asparagine-linked carbohydrates. Sulfated carbohydrate was localized first to the N-terminal half of the mature subunit (amino acids 1 through 1,365) by partial proteolytic digestion with protease V8; and subsequently to a smaller fragment within this region (amino acids 273 through 511) by sequential digestions with protease V8 and trypsin. Thus, the carbohydrate at asparagine 384 and/or 468 appears to be the site of sulfate modification. Sodium chlorate, an inhibitor of adenosine triphosphate-sulfurylase, blocks sulfation of vWF without affecting either the ability of vWF to assemble into high molecular weight multimers or the ability of vWF multimers to enter Weible-Palade bodies. The stability of vWF multimers in the presence of an endothelial cell monolayer also was unaffected by the sulfation state. Additionally, we have found that the cleaved propeptide of vWF is sulfated on asparagine-linked carbohydrate

  15. Increased production of wax esters in transgenic tobacco plants by expression of a fatty acid reductase:wax synthase gene fusion.

    Science.gov (United States)

    Aslan, Selcuk; Hofvander, Per; Dutta, Paresh; Sun, Chuanxin; Sitbon, Folke

    2015-12-01

    Wax esters are hydrophobic lipids consisting of a fatty acid moiety linked to a fatty alcohol with an ester bond. Plant-derived wax esters are today of particular concern for their potential as cost-effective and sustainable sources of lubricants. However, this aspect is hampered by the fact that the level of wax esters in plants generally is too low to allow commercial exploitation. To investigate whether wax ester biosynthesis can be increased in plants using transgenic approaches, we have here exploited a fusion between two bacterial genes together encoding a single wax ester-forming enzyme, and targeted the resulting protein to chloroplasts in stably transformed tobacco (Nicotiana benthamiana) plants. Compared to wild-type controls, transgenic plants showed both in leaves and stems a significant increase in the total level of wax esters, being eight-fold at the whole plant level. The profiles of fatty acid methyl ester and fatty alcohol in wax esters were related, and C16 and C18 molecules constituted predominant forms. Strong transformants displayed certain developmental aberrations, such as stunted growth and chlorotic leaves and stems. These negative effects were associated with an accumulation of fatty alcohols, suggesting that an adequate balance between formation and esterification of fatty alcohols is crucial for a high wax ester production. The results show that wax ester engineering in transgenic plants is feasible, and suggest that higher yields may become achieved in the near future.

  16. Effects of oxidation on the hydrolysis by cholesterol esterase of sitosteryl esters as compared to a cholesteryl ester.

    Science.gov (United States)

    Julien-David, Diane; Ennahar, Saïd; Miesch, Michel; Geoffroy, Philippe; Raul, Francis; Aoude-Werner, Dalal; Lessinger, Jean-Marc; Marchioni, Eric

    2009-10-01

    Phytosteryl esters (PE) are used as ingredients in functional food to decrease plasma concentration of low density lipoprotein-cholesterol (LDL-C). Effective impairment of cholesterol absorption by PE suggests that these esters are hydrolyzed by the pancreatic cholesterol esterase (CEase, EC 3.1.1.13) and the liberated sterol may interfere with cholesterol reducing its intestinal absorption. PE-enriched foods are marketed for cooking purposes, and temperature is one of the most important factors leading to the formation of oxidation products. Very little is known about the outcome of PE oxides during the digestive process. A new analytical method based on mass spectrometric detection directly after enzymatic reaction was developed to determine in vitro the activity of CEase on PE and their oxides present in functional food. Using this method, we identified a new inhibitor of CEase: sitosteryl 9,10-dihydroxystearate, which behaves as a non-competitive inhibitor of the hydrolysis of cholesteryl oleate and sitosteryl oleate.

  17. Preparation of Spirocyclic β-Proline Esters

    DEFF Research Database (Denmark)

    Fjelbye, Kasper; Marigo, Mauro; Clausen, Rasmus Prætorius

    2017-01-01

    A series of novel N-Bn-protected spirocyclic β-proline esters were prepared using [3+2] cycloaddition and subsequently converted into their corresponding aldehydes. In addition, two novel N-Cbz-protected spirocyclic β-proline esters were prepared using intramolecular cyclization starting from sim...

  18. Applications of heparin and heparan sulfate microarrays.

    Science.gov (United States)

    Yin, Jian; Seeberger, Peter H

    2010-01-01

    Carbohydrate microarrays have become crucial tools for revealing the biological interactions and functions of glycans, primarily because the microarray format enables the investigation of large numbers of carbohydrates at a time. Heparan sulfate (HS) and heparin are the most structurally complex glycosaminoglycans (GAGs). In this chapter, we describe the preparation of a small library of HS/heparin oligosaccharides, and the fabrication of HS/heparin microarrays that have been used to establish HS/heparin-binding profiles. Fibroblast growth factors (FGFs), natural cytotoxicity receptors (NCRs), and chemokines were screened to illuminate the very important biological functions of these glycans. Copyright (c) 2010 Elsevier Inc. All rights reserved.

  19. Anticholinesterase activity of fluorochloronitroacetic acid esters

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, Yu.Ya.; Brel, V.K. Martynov, I.V.

    1984-11-01

    Results are presented from pharmacologic and biochemical experiments leading to the conclusion that fluorochloronitroacetic acid esters have anticholinesterase activity. Since the esters caused muscular weakness in mice, experiments were performed on isolated tissue preparation. The biochemical experiments consisted of finding the biomolecular constants of irreversible inhibition of acetylcholinesterase by the esters, using acetylcholinesterase from human erythrocytes, as well as horse serum cholinesterase. The ethyl and n-propyl esters of halogen nitroacetic acid were used in all experiments. It was found that the propyl ester caused an increase in the force of individual contractions in the isolated muscle specimens, plus an inability of the muscle to retain tetanus. The substances were determined to have an anticholinesterase effect. The mechanism of cholinesterase inhibition is not yet known. It is probable that the substances acylate the serine hydroxyl of the esterase center of the cholinestersase. 7 references, 1 figure.

  20. Synthesis, characterization and application of lipase-conjugated citric acid-coated magnetic nanoparticles for ester synthesis using waste frying oil.

    Science.gov (United States)

    Patel, Unisha; Chauhan, Kishor; Gupte, Shilpa

    2018-04-01

    In the present work, magnetic nanoparticles (MNPs) were prepared by chemical precipitation of trivalent and divalent iron ions which were functionalized using citric acid. The bacterial isolate Staphylococcus epidermidis KX781317 was isolated from oil-contaminated site. The isolate produced lipase, which was purified and immobilized on magnetic nanoparticles (MNPs) for ester synthesis from waste frying oil (WFO). The characterization of MNPs employed conventional TEM, XRD and FTIR techniques. TEM analysis of MNPs showed the particle size in the range of 20-50 nm. FTIR spectra revealed the binding of citric acid to Fe 3 O 4 and lipase on citric acid-coated MNPs. The citric acid-coated MNPs and lipase-conjugated citric acid-coated MNPs had similar XRD patterns which indicate MNPs could preserve their magnetic properties. The maximum immobilization efficiency 98.21% of lipase-containing citric acid-coated MNPs was observed at ratio 10:1 of Cit-MNPs:lipase. The pH and temperature optima for lipase conjugated with Cit-MNPs were 7 and 35 °C, respectively. Isobutanol was found to be an effective solvent for ester synthesis and 1:2 ratio of oil:alcohol observed significant for ester formation. The ester formation was determined using TLC and the % yield of ester conversion was calculated. The rate of ester formation is directly proportional to the enzyme load. Formed esters were identified as isobutyl laurate ester and isobutyl myristate ester through GC-MS analysis.

  1. Physiochemical properties of alkylaminium sulfates: hygroscopicity, thermostability, and density.

    Science.gov (United States)

    Qiu, Chong; Zhang, Renyi

    2012-04-17

    Although heterogeneous interaction of amines has been recently shown to play an important role in the formation and growth of atmospheric aerosols, little information is available on the physicochemical properties of aminium sulfates. In this study, the hygroscopicity, thermostability, and density of alkylaminium sulfates (AASs) have been measured by an integrated aerosol analytical system including a tandem differential mobility analyzer and an aerosol particle mass analyzer. AAS aerosols exhibit monotonic size growth at increasing RH without a well-defined deliquescence point. Mixing of ammonium sulfate (AS) with AASs lowers the deliquescence point corresponding to AS. Particles with AASs show comparable or higher thermostability than that of AS. The density of AASs is determined to be 1.2-1.5 g cm(-3), and an empirical model is developed to predict the density of AASs on the basis of the mole ratio of alkyl carbons to total sulfate. Our results reveal that the heterogeneous uptake of amines on sulfate particles may considerably alter the aerosol properties. In particular, the displacement reaction of alkylamines with ammonium sulfate aerosols leads to a transition from the crystalline to an amorphorous phase and an improved water uptake, considerably enhancing their direct and indirect climate forcing.

  2. Heparan sulfate and cell division

    Directory of Open Access Journals (Sweden)

    Porcionatto M.A.

    1999-01-01

    Full Text Available Heparan sulfate is a component of vertebrate and invertebrate tissues which appears during the cytodifferentiation stage of embryonic development. Its structure varies according to the tissue and species of origin and is modified during neoplastic transformation. Several lines of experimental evidence suggest that heparan sulfate plays a role in cellular recognition, cellular adhesion and growth control. Heparan sulfate can participate in the process of cell division in two distinct ways, either as a positive or negative modulator of cellular proliferation, or as a response to a mitogenic stimulus.

  3. Preparation of Highly Pure Vanadyl Sulfate from Sulfate Solutions Containing Impurities of Iron and Aluminum by Solvent Extraction Using EHEHPA

    Directory of Open Access Journals (Sweden)

    Dan Li

    2017-03-01

    Full Text Available The preparation of highly pure vanadyl sulfate from sulfate solutions containing impurities of iron and aluminumwas investigated by solvent extraction with 2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester (EHEHPA and tri-n-butyl phosphate (TBP as the phase modifier. The extraction and stripping conditions of vanadium (IV and its separation from iron and aluminum were optimized. Under the optimal extraction conditions, the extraction of vanadium (IV and iron were 68% and 53%, respectively, while only 2% aluminum was extracted in a single contact, suggesting good separation of vanadium (IV from aluminum. Sulfuric acid solution was used for the stripping. Nearly 100% vanadium (IV and 95% aluminum were stripped, while only 10% iron was stripped under the optimal stripping conditions in a single contact, suggesting good separation of vanadium (IV from iron. After five stages of extraction and stripping, highly pure vanadyl sulfate containing 76.5 g/L V (IV with the impurities of 12 mg/L Fe and 10 mg/L Al was obtained, which is suitable for the electrolyte of a vanadium redox flow battery. Organic solution was well regenerated after stripping by oxalic acid solution to remove the remaining iron. The mechanism of vanadium (IV extraction using EHEHPA was also discussed based on the Fourier transform infrared spectroscopy (FT-IR analysis.

  4. Sulfate reduction with methanol by a thermophilic consortium obtained from a methanogenic reactor

    Energy Technology Data Exchange (ETDEWEB)

    Davidova, I.A. [Wageningen Agricultural Univ. (Netherlands). Dept. of Microbiology; Stams, A.J.M. [Wageningen Agricultural Univ. (Netherlands). Dept. of Microbiology

    1996-12-31

    An enrichment culture obtained from anaerobic granular sludge of a bench-scale anarobic reactor degraded methanol at 65 C via sulfate reduction and acetogenesis. Sulfate reduction was the dominant process (S{sup 2-}/acetate=2.5). No methane formation was observed. Approximately 30% of the methanol was converted by acetogenic bacteria to acetate, while the remainder was degraded by these bacteria to H{sub 2} and CO{sub 2} in syntrophy with hydrogen-consuming sulfate-reducing bacteria. Pure cultures of sulfate-reducing and acetogenic bacteria were isolated and characterized. (orig.)

  5. p-Cresyl Sulfate

    Directory of Open Access Journals (Sweden)

    Tessa Gryp

    2017-01-01

    Full Text Available If chronic kidney disease (CKD is associated with an impairment of kidney function, several uremic solutes are retained. Some of these exert toxic effects, which are called uremic toxins. p-Cresyl sulfate (pCS is a prototype protein-bound uremic toxin to which many biological and biochemical (toxic effects have been attributed. In addition, increased levels of pCS have been associated with worsening outcomes in CKD patients. pCS finds its origin in the intestine where gut bacteria metabolize aromatic amino acids, such as tyrosine and phenylalanine, leading to phenolic end products, of which pCS is one of the components. In this review we summarize the biological effects of pCS and its metabolic origin in the intestine. It appears that, according to in vitro studies, the intestinal bacteria generating phenolic compounds mainly belong to the families Bacteroidaceae, Bifidobacteriaceae, Clostridiaceae, Enterobacteriaceae, Enterococcaceae, Eubacteriaceae, Fusobacteriaceae, Lachnospiraceae, Lactobacillaceae, Porphyromonadaceae, Staphylococcaceae, Ruminococcaceae, and Veillonellaceae. Since pCS remains difficult to remove by dialysis, the gut microbiota could be a future target to decrease pCS levels and its toxicity, even at earlier stages of CKD, aiming at slowing down the progression of the disease and decreasing the cardiovascular burden.

  6. Specific inhibition of FGF-2 signaling with 2-O-sulfated octasaccharides of heparan sulfate.

    Science.gov (United States)

    Ashikari-Hada, Satoko; Habuchi, Hiroko; Sugaya, Noriko; Kobayashi, Takashi; Kimata, Koji

    2009-06-01

    In fibroblast growth factor (FGF)-2 signaling, the formation of a ternary complex of FGF-2, tyrosine-kinase fibroblast growth factor receptor (FGFR)-1, and cell surface heparan sulfate (HS) proteoglycan is known to be critical for the activation of FGFR-1 and downstream signal transduction. Exogenous heparin polymer and some octasaccharides inhibited FGF-2-induced phosphorylation both of FGFR-1 and of extracellular signal-regulated kinase (ERK1/2) in Chinese hamster ovary (CHO)-K1 cells transfected with FGFR-1, which present HS on their cell surface. The inhibitory effect of octasaccharide was dependent on the number of 2-O-sulfate groups within a molecule but independent of the number of 6-O-sulfate groups. Sulfation at the 2-O-position was a prerequisite not only for the binding of HS to FGF-2 but also for regulation of FGF-2 signaling and competitive inhibition with endogenous HS. Interestingly, FGF-4-induced phosphorylation was impeded only by specific octasaccharides containing both 2-O- and 6-O-sulfated groups, which were necessary for binding FGF-4. In CHO-677 cells deficient in HS biosynthesis, heparin enhanced FGF-2-induced phosphorylation of ERK1/2. On the other hand, an FGF-2-binding octasaccharide inhibited the phosphorylation. Our data suggest that the activity of particular heparin-binding factors can be inhibited by distinctive oligosaccharides that can bind the factors but cannot form functional signaling complexes irrespective of whether cells have a normal complement of HS or lack HS.

  7. Final report on the safety assessment of sodium cetearyl sulfate and related alkyl sulfates as used in cosmetics.

    Science.gov (United States)

    Fiume, Monice; Bergfeld, Wilma F; Belsito, Donald V; Klaassen, Curtis D; Marks, James G; Shank, Ronald C; Slaga, Thomas J; Snyder, Paul W; Alan Andersen, F

    2010-05-01

    Sodium cetearyl sulfate is the sodium salt of a mixture of cetyl and stearyl sulfate. The other ingredients in this safety assessment are also alkyl salts, including ammonium coco-sulfate, ammonium myristyl sulfate, magnesium coco-sulfate, sodium cetyl sulfate, sodium coco/hydrogenated tallow sulfate, sodium coco-sulfate, sodium decyl sulfate, sodium ethylhexyl sulfate, sodium myristyl sulfate, sodium oleyl sulfate, sodium stearyl sulfate, sodium tallow sulfate, sodium tridecyl sulfate, and zinc coco-sulfate. These ingredients are surfactants used at concentrations from 0.1% to 29%, primarily in soaps and shampoos. Many of these ingredients are not in current use. The Cosmetic Ingredient Review (CIR) Expert Panel previously completed a safety assessment of sodium and ammonium lauryl sulfate. The data available for sodium lauryl sulfate and ammonium lauryl sulfate provide sufficient basis for concluding that sodium cetearyl sulfate and related alkyl sulfates are safe in the practices of use and concentration described in the safety assessment.

  8. Sulfation of Condensed Potassium Chloride by SO2

    DEFF Research Database (Denmark)

    Sengeløv, Louise With; Hansen, Troels Bruun; Bartolomé, Carmen

    2013-01-01

    The interaction between alkali chloride and sulfur oxides has important implications for deposition and corrosion in combustion of biomass. In the present study, the sulfation of particulate KCl (90–125 μm) by SO2 was studied in a fixed bed reactor in the temperature range 673–1023 K and with rea......The interaction between alkali chloride and sulfur oxides has important implications for deposition and corrosion in combustion of biomass. In the present study, the sulfation of particulate KCl (90–125 μm) by SO2 was studied in a fixed bed reactor in the temperature range 673–1023 K...... and with reactant concentrations of 500–3000 ppm SO2, 1–20% O2, and 4–15% H2O. The degree of sulfation was monitored by measuring the formation of HCl. Analysis of the solid residue confirmed that the reaction proceeds according to a shrinking core model and showed the formation of an eutectic at higher...... temperatures. On the basis of the experimental results, a rate expression for the sulfation reaction was derived. The model compared well with literature data for sulfation of KCl and NaCl, and the results indicate that it may be applied at even higher SO2 concentrations and temperatures than those...

  9. Enhanced Sulfate Management in HLW Glass Formulations VSL12R2540-1 REV 0

    Energy Technology Data Exchange (ETDEWEB)

    Kruger, A. A. [Department of Energy, Office of River Protection, Richland, Washington (United States); Pegg, Ian L. [The Catholic University of America, Washington, DC (United States); Kot, Wing [The Catholic University of America, Washington, DC (United States); Gan, Hao [The Catholic University of America, Washington, DC (United States); Matlack, Keith S. [The Catholic University of America, Washington, DC (United States)

    2012-11-13

    The Low Activity Waste (LAW) tanks that are scheduled to provide the Hanford Tank Waste Treatment and Immobilization Plant (WTP) with waste feeds contain significant amounts of sulfate. The sulfate content in the LAW feeds is sufficiently high that a separate molten sulfate salt phase may form on top of the glass melt during the vitrification process unless suitable glass formulations are employed and sulfate levels are controlled. Since the formation of the salt phase is undesirable from many perspectives, mitigation approaches had to be developed. Considerable progress has been made and reported by the Vitreous State Laboratory (VSL) in enhancing sulfate incorporation into LAW glass melts and developing strategies to manage and mitigate the risks associated with high-sulfate feeds.

  10. A zinc complex of heparan sulfate destabilises lysozyme and alters its conformation

    International Nuclear Information System (INIS)

    Hughes, Ashley J.; Hussain, Rohanah; Cosentino, Cesare; Guerrini, Marco; Siligardi, Giuliano; Yates, Edwin A.; Rudd, Timothy R.

    2012-01-01

    Highlights: ► Zinc–heparan sulfate complex destabilises lysozyme, a model amyloid protein. ► Addition of zinc, without heparan sulfate, stabilises lysozyme. ► Heparan sulfate cation complexes provide alternative protein folding routes. -- Abstract: The naturally occurring anionic cell surface polysaccharide heparan sulfate is involved in key biological activities and is implicated in amyloid formation. Following addition of Zn–heparan sulfate, hen lysozyme, a model amyloid forming protein, resembled β-rich amyloid by far UV circular dichroism (increased β-sheet: +25%), with a significantly reduced melting temperature (from 68 to 58 °C) by fluorescence shift assay. Secondary structure stability of the Zn–heparan sulfate complex with lysozyme was also distinct from that with heparan sulfate, under stronger denaturation conditions using synchrotron radiation circular dichroism. Changing the cation associated with heparan sulfate is sufficient to alter the conformation and stability of complexes formed between heparan sulfate and lysozyme, substantially reducing the stability of the protein. Complexes of heparan sulfate and cations, such as Zn, which are abundant in the brain, may provide alternative folding routes for proteins.

  11. Natural Organochlorines as Precursors of 3-Monochloropropanediol Esters in Vegetable Oils.

    Science.gov (United States)

    Tiong, Soon Huat; Saparin, Norliza; Teh, Huey Fang; Ng, Theresa Lee Mei; Md Zain, Mohd Zairey Bin; Neoh, Bee Keat; Md Noor, Ahmadilfitri; Tan, Chin Ping; Lai, Oi Ming; Appleton, David Ross

    2018-01-31

    During high-temperature refining of vegetable oils, 3-monochloropropanediol (3-MCPD) esters, possible carcinogens, are formed from acylglycerol in the presence of a chlorine source. To investigate organochlorine compounds in vegetable oils as possible precursors for 3-MCPD esters, we tested crude palm, soybean, rapeseed, sunflower, corn, coconut, and olive oils for the presence of organochlorine compounds. Having found them in all vegetable oils tested, we focused subsequent study on oil palm products. Analysis of the chlorine isotope mass pattern exhibited in high-resolution mass spectrometry enabled organochlorine compound identification in crude palm oils as constituents of wax esters, fatty acid, diacylglycerols, and sphingolipids, which are produced endogenously in oil palm mesocarp throughout ripening. Analysis of thermal decomposition and changes during refining suggested that these naturally present organochlorine compounds in palm oils and perhaps in other vegetable oils are precursors of 3-MCPD esters. Enrichment and dose-response showed a linear relationship to 3-MCPD ester formation and indicated that the sphingolipid-based organochlorine compounds are the most active precursors of 3-MCPD esters.

  12. FTIR study of hydrogen bonding between substituted benzyl alcohols and acrylic esters

    Directory of Open Access Journals (Sweden)

    P. Sivagurunathan

    2016-11-01

    Full Text Available Hydrogen bonding between substituted benzyl alcohols (benzyl alcohol, o-aminobenzyl alcohol, o-chlorobenzyl alcohol and o-nitrobenzyl alcohol and acrylic esters (methyl methacrylate, ethyl methacrylate is studied in carbon tetrachloride by using the FTIR spectroscopic method. Utilizing the Nash method, the formation constant (K of the 1:1 complexes is calculated. Using the K value, the Gibbs free energy change (ΔG0 is also calculated. The calculated formation constant and Gibbs free energy change values vary with the substituent of benzyl alcohol and ester chain length, which suggests that the proton donating ability of substituted benzyl alcohols is in the order: o-aminobenzyl alcohol < benzyl alcohol < o-chlorobenzyl alcohol < o-nitrobenzyl alcohol, and proton accepting ability of acrylic esters is in the order: methyl methacrylate < ethyl methacrylate.

  13. Human pharmacokinetics of ethynyl estradiol 3-sulfate and 17-sulfate.

    Science.gov (United States)

    Goldzieher, J W; Mileikowsky, G; Newburger, J; Dorantes, A; Stavchansky, S A

    1988-01-01

    Pharmacokinetic parameters of ethynyl estradiol 3-sulfate (EE-3) and 17-sulfate (EE-17) were estimated. Each sulfate was administered orally and intravenously to five ovariectomized volunteer women. Blood samples were taken over a period of 24 h. Radioimmunoassay for free and sulfoconjugated ethynyl estradiol (EE) was performed. The analysis of the plasma concentrations obtained after administration of EE-3 and EE-17 indicates significant differences in their pharmacokinetic profiles. EE-3 is cleared more rapidly from the central compartment (systemic circulation), which may indicate that differences in protein binding, tissue binding, metabolism, and distribution exist between EE-3 and EE-17. It has been suggested that these conjugates are a slow-release reservoir for maintenance of blood levels of free EE itself. However, previous studies in baboons have shown that the half-lives of the free and sulfoconjugated EE are similar (ranging from 8.8 to 11.2 h), which is not consistent with this hypothesis. The t1/2 beta (mean 9.28 h) of the 17-sulfate after IV administration was almost identical in women and baboons, and similar to the t1/2 beta of free EE, confirming the previous observation. Only 3.4% of IV and 11.4% of the orally administered 17-sulfate appeared in the blood as free EE; with the 3-sulfate, the conversions were 13.7 and 20.7%, respectively, suggesting that these sulfates are not important slow-release reservoirs. The similarity of pharmacokinetic parameters between women and baboons suggests that this species of nonhuman primate is, in important respects, a suitable animal model for clinical pharmacology.

  14. Fractionation of sulfur isotopes in the chemical and biochemical oxidation of sulfide to sulfate

    International Nuclear Information System (INIS)

    Maass, I.; Wetzel, K.; Weise, G.; Heyer, J.

    1983-01-01

    The behaviour of sulfur isotopes in the chemical and biochemical oxidation of marcasite (FeS 2 ) to sulfate has been investigated in rest and shaker cultures at 30 0 C. The microbiological oxidation was carried out using a mixed culture of Thiobacillus. The results show a considerably faster formation of sulfate in the biochemical oxidation in comparison with the chemical oxidation. Isotope analyses of the formed sulfates indicate no or only very small isotope fractionations depending on experimental conditions. The highest enrichment of 32 S in the sulfate is 1.7 per mille. In accordance with the results of other authors it is concluded that in both chemical and biochemical weathering of sedimentary sulfides resulting in the formation of sulfates isotope effects are not of importance. (author)

  15. Pressure effect on dissimilatory sulfate reduction

    Science.gov (United States)

    Williamson, A. J.; Carlson, H. K.; Coates, J. D.

    2015-12-01

    Biosouring is the production of H2S by sulfate reducing microorganisms (SRM) in-situ or in the produced fluids of oil reservoirs. Sulfide is explosive, toxic and corrosive which can trigger equipment and transportation failure, leading to environmental catastrophe. As oil exploration and reservoir development continue, subsequent enhanced recovery is occurring in progressively deeper formations and typical oil reservoir pressures range from 10-50 MPa. Therefore, an understanding of souring control effects will require an accurate understanding of the influence of pressure on SRM metabolism and the efficacy of souring control treatments at high pressure. Considerable work to date has focussed on souring control at ambient pressure; however, the influence of pressure on biogeochemical processes and souring treatments in oil reservoirs is poorly understood. To explore the impact of pressure on SRM, wild type Desulfovibrio alaskensis G20 (isolated from a producing oil well in Ventura County, California) was grown under a range of pressures (0.1-14 MPa) at 30 °C. Complete sulfate reduction occurred in all pressures tested within 3 days, but microbial growth was inhibited with increasing pressure. Bar-seq identified several genes associated with flagella biosynthesis (including FlhB) and assembly as important for survival at elevated pressure and fitness was confirmed using individual transposon mutants. Flagellar genes have previously been implicated with biofilm formation and confocal microscopy on glass slides incubated with wild type D. alaskensis G20 showed more biomass associated with surfaces under pressure, highlighting the link between pressure, flagellar and biofilm formation. To determine the effect of pressure on the efficacy of SRM inhibitors, IC50 experiments were conducted and D. alaskensis G20 showed a greater resistance to nitrate and the antibiotic chloramphenicol, but a lower resistance to perchlorate. These results will be discussed in the context of

  16. Synthesis of Trimethylolpropane Esters of Calophyllum Methyl Esters : Effect of Temperature and Molar Ratio

    Directory of Open Access Journals (Sweden)

    Yeti Widyawati

    2014-12-01

    Full Text Available Trimethylolpropane esters were synthesized by transesterification of calophyllum methyl esters and trimethylolpropane using a calcium oxide as the catalyst. The results showed that the optimal reaction conditions (temperature: 130 0C, reaction time: 5 h, reactant molar ratio: 3.9:1, catalyst amount 3%w/w, and formed  trimethylolpropane ester of 79.0% were obtained. The basic physicochemical properties of the trimethylolpropane esters were the following : kinematic viscosities of 56.40 cSt and 8.8 cSt at 40 0C and 100 0C,  viscosity index 193, flash point 218 0C and pour point -3 0C. So Methyl esters of fatty acids of would callophylum  methyl ester is good raw material for the synthesis of lubricating oils.

  17. Cobalt-catalyzed hydrogenation of esters to alcohols: unexpected reactivity trend indicates ester enolate intermediacy.

    Science.gov (United States)

    Srimani, Dipankar; Mukherjee, Arup; Goldberg, Alexander F G; Leitus, Gregory; Diskin-Posner, Yael; Shimon, Linda J W; Ben David, Yehoshoa; Milstein, David

    2015-10-12

    The atom-efficient and environmentally benign catalytic hydrogenation of carboxylic acid esters to alcohols has been accomplished in recent years mainly with precious-metal-based catalysts, with few exceptions. Presented here is the first cobalt-catalyzed hydrogenation of esters to the corresponding alcohols. Unexpectedly, the evidence indicates the unprecedented involvement of ester enolate intermediates. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Stability of sulfate complexes of electronically excited uranyl

    Energy Technology Data Exchange (ETDEWEB)

    Ostakhov, S.S.; Kazakov, V.P.; Afonichev, D.D. [Inst. of Organic Chemistry, Ufa (Russian Federation)

    1995-11-01

    The complex formation of electronically excited uranyl ions with SO{sub 4}{sup 2-}anions in 0.1 M aqueous HClO{sub 4} has been studied by time-resolved luminescence spectroscopy. The stability constants of uranyl sulfate complexes (UO{sub 2}SO{sub 4}) (K=870 1 mol{sup -1}) and [UO{sub 2}(SO{sub 4}){sub 2}{sup 2-}](K=47000 1 mol{sup -1}) in excited state have been determined; they are more than an order of magnitude greater than those reported for complex formation of uranyl ions in the ground state. The complex formation of uranyl with sulfate ions is accompanied by the increase of the quantum yield of the uranyl lumenescence. The maxima of luminescence and absorption bands of uranyl ions are shifted with increasing the total concentration of SO{sub 4}{sup 2-} in solution, which supports the data obtained. The shift of the maxima of luminescence bands is observed at a sulfate concentration that is considerably lower than that causing the same shift of the maxima of the absorption bands. Such effect is consistent with the calculated stability constants of sulfate complexes of excited uranyl ions.

  19. Post-flame gas-phase sulfation of potassium chloride

    DEFF Research Database (Denmark)

    Li, Bo; Sun, Zhiwei; Li, Zhongshan

    2013-01-01

    The sulfation of KCl during biomass combustion has implications for operation and emissions: it reduces the rates of deposition and corrosion, it increases the formation of aerosols, and it leads to higher concentrations of HCl and lower concentrations of SO2 in the gas phase. Rigorously homogene......The sulfation of KCl during biomass combustion has implications for operation and emissions: it reduces the rates of deposition and corrosion, it increases the formation of aerosols, and it leads to higher concentrations of HCl and lower concentrations of SO2 in the gas phase. Rigorously...... homogeneous systems are required to characterize the gas-phase formation of alkali sulfates. We have measured the temperature and gas-phase concentrations of KCl and HCl, and detected the presence of aerosols in the post-flame region of a range of hydrocarbon flames seeded with KCl, with and without...... and HCl and aerosols formed, most pronounced in flames with the lowest post-flame temperatures. This shows that KCl is sulfated in the gas phase to K2SO4, and this is followed by homogeneous nucleation of K2SO4 to form aerosols. Predictions from a kinetic model of the S/Cl/K chemistry agreed well...

  20. 21 CFR 172.854 - Polyglycerol esters of fatty acids.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyglycerol esters of fatty acids. 172.854 Section... HUMAN CONSUMPTION Multipurpose Additives § 172.854 Polyglycerol esters of fatty acids. Polyglycerol esters of fatty acids, up to and including the decaglycerol esters, may be safely used in food in...

  1. Synthesis of sulfur-containing lubricant additives on the basis of fatty acid ethyl esters

    Directory of Open Access Journals (Sweden)

    Iurii S. Bodachivskyi

    2016-12-01

    Full Text Available The study reveals an energy-, resource- and eco-friendly method for preparation of sulfur-containing lubricant additives via interaction of fatty acid ethyl esters of rapeseed oil with elemental sulfur. The structure of synthesized compounds under various reactants ratio (5–50 wt.% of sulfur, duration (30–240 min and temperature of the process (160–215°С was investigated using various analytical techniques. According to the established data, aside from addition to double bonds, the side reaction of hydrogen substitution at α-methylene groups near these bonds occurs and induces the formation of conjugated systems and chromophoric sulfur-rich derivatives. Also, we found that increase of process duration evokes growth of polysulfane chains, in contrast to the raise of temperature, which leads to the formation of sulfur-containing heterocycles and hydrogen sulfide, as a result of elimination. Influence of accelerators on sulfurization of fatty acid ethyl esters was also examined. The most effective among them are mixtures of zinc dibutyldithiocarbamate with zinc oxide or stearic acid, which soften synthesis conditions and doubly decrease duration of the high-temperature stage. In addition, sulfur-containing compositions of ethyl esters and α-olefins, vulcanized esters by benzoyl peroxide, nonylphenols and zinc dinonylphenyldithiophosphate were designed. The study identified that lithium lubricant with sulfurized vulcanized esters provides improved tribological properties, in comparison with base lubricant or lubricant with the non-modified product.

  2. Thermal Decomposition of Methyl Esters in Biodiesel Fuel: Kinetics, Mechanisms and Products

    Science.gov (United States)

    Chai, Ming

    Biodiesel continues to enjoy increasing popularity. However, recent studies on carbonyl compounds emissions from biodiesel fuel are inconclusive. Emissions of carbonyl compounds from petroleum diesel fuels were compared to emissions from pure biodiesel fuels and petroleum-biodiesel blends used in a non-road diesel generator. The concentration of total carbonyl compounds was the highest when the engine was idling. The carbonyl emissions, as well as ozone formation potential, from biodiesel fuel blends were higher than those emitted from petroleum diesel fuel. The sulfur content of diesel fuel and the source of biodiesel fuel were not found to have a significant impact on emissions of carbonyl compounds. Mechanism parameters of the thermal decomposition of biodiesel-range methyl esters were obtained from the results of thermal gravimetric analysis (TGA). The overall reaction orders are between 0.49 and 0.71 and the energies of activation are between 59.9 and 101.3 kJ/mole. Methyl esters in air have lower activation energies than those in nitrogen. Methyl linoleate has the lowest activation energy, followed by methyl oleate, and methyl stearate. The pyrolysis and oxidation of the three methyl esters were investigated using a semi-isothermal tubular flow reactor. The profiles of major products versus reaction temperature are presented. In the pyrolysis of methyl stearate, the primary reaction pathway is the decarboxylic reaction at the methyl ester functional group. Methyl oleate's products indicate more reactions on its carbon-carbon double bond. Methyl linoleate shows highest reactivity among the three methyl esters, and 87 products were detected. The oxidation of three methyl esters resulted in more products in all compound classes, and 55, 114, and 127 products were detected, respectively. The oxidation of methyl esters includes decarboxylation on ester group. The methyl ester's carbon chain could be oxidized as a hydrocarbon compound and form oxidized esters and

  3. Pharmacokinetics of Ketorolac Pentyl Ester, a Novel Ester Derivative of Ketorolac, in Rabbits

    Directory of Open Access Journals (Sweden)

    Jann-Inn Tzeng

    2005-08-01

    Full Text Available Ketorolac is a potent nonsteroidal anti-inflammatory drug. Recently, a novel ester of ketorolac, ketorolac pentyl ester, was synthesized. When prepared in injectable oil, the new agent demonstrated a long duration of action. Ketorolac pentyl ester was synthesized using a prodrug design by esterification of ketorolac, and appeared to be a prodrug of ketorolac in vivo, which needed to be confirmed. The aim of the present study was to establish the prodrug's pharmacokinetics in vivo, and to confirm whether or not ketorolac pentyl ester was a prodrug of ketorolac. Pharmacokinetic profiles of intravenous ketorolac and its pentyl ester on an equal-molar basis in six rabbits were evaluated. A high-performance liquid chromatographic method was used to determine the plasma concentrations of ketorolac and its pentyl ester. We found that the plasma concentrations of ketorolac pentyl ester declined rapidly after injection and so did the conversion of ketorolac pentyl ester to ketorolac. Also, the conversion of ketorolac was proved complete when compared with intravenous ketorolac under an equi-molar basis. In conclusion, this in vivo pharmacokinetic study confirmed that keterolac pentyl ester was a prodrug of keterolac.

  4. Macrophage secretory products selectively stimulate dermatan sulfate proteoglycan production in cultured arterial smooth muscle cells

    International Nuclear Information System (INIS)

    Edwards, I.J.; Wagner, W.D.; Owens, R.T.

    1990-01-01

    Arterial dermatan sulfate proteoglycan has been shown to increase with atherosclerosis progression, but factors responsible for this increase are unknown. To test the hypothesis that smooth muscle cell proteoglycan synthesis may be modified by macrophage products, pigeon arterial smooth muscle cells were exposed to the media of either cholesteryl ester-loaded pigeon peritoneal macrophages or a macrophage cell line P388D1. Proteoglycans radiolabeled with [35S]sulfate and [3H]serine were isolated from culture media and smooth muscle cells and purified following precipitation with 1-hexadecylpyridinium chloride and chromatography. Increasing concentrations of macrophage-conditioned media were associated with a dose-response increase in [35S]sulfate incorporation into secreted proteoglycans, but there was no change in cell-associated proteoglycans. Incorporation of [3H]serine into total proteoglycan core proteins was not significantly different (5.2 X 10(5) dpm and 5.5 X 10(5) disintegrations per minute (dpm) in control and conditioned media-treated cultures, respectively), but selective effects were observed on individual proteoglycan types. Twofold increases in dermatan sulfate proteoglycan and limited degradation of chondroitin sulfate proteoglycan were apparent based on core proteins separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Immunoinhibition studies indicated that interleukin-1 was involved in the modulation of proteoglycan synthesis by macrophage-conditioned media. These data provide support for the role of macrophages in alteration of the matrix proteoglycans synthesized by smooth muscle cells and provide a mechanism to account for the reported increased dermatan sulfate/chondroitin sulfate ratios in the developing atherosclerotic lesion

  5. Conversion of carbohydrates to levulinic acid esters

    DEFF Research Database (Denmark)

    2014-01-01

    The present invention relates to the field of converting carbohydrates into levulinic acid, a platform chemical for many chemical end products. More specifically the invention relates to a method for converting carbohydrates such as mono-, di- or polysaccharides, obtained from for example biomass...... production into a suitable levulinic acid ester in the presence of a zeolite or zeotype catalyst and a suitable alcohol, and the ester may be further converted into levulinic acid if desired....

  6. Asymmetric synthesis of α-amino acids by reduction of N-tert-butanesulfinyl ketimine esters.

    Science.gov (United States)

    Reddy, Leleti Rajender; Gupta, Aditya P; Liu, Yugang

    2011-05-06

    A highly regio- and diastereoselective reduction of various N-tert-butanesulfinyl ketimine esters with L-Selectride resulting in the formation of α-amino acids is reported. This method is quite general and also practical for the preparation of both enantiomers of aryl or aliphatic α-amino acids in high yields. © 2011 American Chemical Society

  7. Allied, MGC link on cyanate esters

    International Nuclear Information System (INIS)

    Wood, A.

    1993-01-01

    In the latest of a line of joint ventures in its plastics business, Allied Signal has reached agreement with Mitsubishi Gas Chemical (MGC) to jointly develop thermoset cyanate ester resins and blends. The deal will involve further development of Allied Signal's Primaset phenol-formaldehyde cyanate ester resins, a new entrant in the thermoset arena. Although the Primaset resins were discovered in the 1960s, this would be the first time they are available commercially. The deal will marry Primaset technology with MGC's Skylex bisphenol A cyanate ester resins, says Fred DiAntonis, director/advanced materials at Allied Signal. The two firms are looking at marketing blends of the two materials. The potential market for these resins, used commercially by the electronics industry in printed circuit boards and by the aerospace industry in composites, is significant, says Robert P. Viarengo, Allied Signal president/performance materials. By aligning ourselves with MGC, the world leader in cyanate ester resin, we anticipate moving forward aggressively. The main competitor is Ciba, which acquired bisphenol A cyanate ester resins with its purchase of Rhone-Poulenc's high temperature resins business. DiAntonis estimates the market for cyanate ester resins could be worth $150 million by the end of the decade, although development costs have been in the tens of millions of dollars range

  8. Uranyl Sulfate Nanotubules Templated by N-phenylglycine

    Directory of Open Access Journals (Sweden)

    Oleg I. Siidra

    2018-04-01

    Full Text Available The synthesis, structure, and infrared spectroscopy properties of the new organically templated uranyl sulfate Na(phgH+7[(UO26(SO410](H2O3.5 (1, obtained at room temperature by evaporation from aqueous solution, are reported. Its structure contains unique uranyl sulfate [(UO26(SO410]8− nanotubules templated by protonated N-phenylglycine (C6H5NH2CH2COOH+. Their internal diameter is 1.4 nm. Each of the nanotubules is built from uranyl sulfate rings sharing common SO4 tetrahedra. The template plays an important role in the formation of the complex structure of 1. The aromatic rings are stacked parallel to each other due to the effect of π–π interaction with their side chains extending into the gaps between the nanotubules.

  9. Application of Chondroitin Sulfate on Organogenesis of Two Cymbidium spp. under Different Sources of Lights

    Directory of Open Access Journals (Sweden)

    Syeda Jabun NAHAR

    2016-06-01

    Full Text Available The aim of this study was to present chondroitin sulfate as a plant growth regulator and to give an overview about light effects on PLBs (protocorm like bodies culture of Cymbidium dayanum and Cymbidium finlaysonianum cultured in vitro. Chondroitin sulfate is a sulfated glycosaminoglycan (GAG composed of a chain of alternating sugars N-acetylgalactosamine and glucuronic acid. It is widely used as a material for food ingredients, cosmetics and medicine. PLBs were cultured on modified MS medium containing different concentration of chondroitin sulfate (0, 0.1, 1 and 10 mg/l, under four sources of lights: conventional white fluorescent tube, red LED, green LED and blue LED. In C. dayanum, 100% PLBs formation rate was observed at 0.1 mg/l chondroitin sulfate with modified MS medium under green LED and 1 mg/l chondroitin sulfate under blue LED; the maximum shoots and roots formation were observed under green LEDs (93% and 80% respectively when media contained 0.1 mg/l chondroitin sulfate. In C. finlaysonianum, every concentrations of chondroitin sulfate enhanced the growth rate of PLBs when compared to control treatment, under all four sources of lights. The highest values were recorded with 0.1 mg/l chondroitin sulfate which induced 100% PLBs formation under blue LED, while 10 mg/l chondroitin sulfate had induced 100% PLBs formation under green LED. The highest percentage of shoots (73% was initiated in the medium containing 10 mg/l chondroitin sulfate under green LED. Plant development was strongly influenced by the light quality and plant growth regulator functions as chemical messengers for intercellular communication of plant. The results demonstrated that low concentrations of chondroitin sulfate could promote PLBs, shoots and roots formation of Cymbidium spp. under green and blue LED.

  10. Allenyl esters as quenching agents for ruthenium olefin metathesis catalysts.

    Science.gov (United States)

    Roy, Animesh; Silvestri, Maximilian A; Hall, Robert A; Lepore, Salvatore D

    2017-01-04

    In the attempt to synthesize substituted allenyl esters through a metathesis coupling of unsubstituted allenyl esters and alkenes using a variety of ruthenium catalysts, it was discovered that allenyl esters themselves cleanly arrested the activity of the catalysts. Further studies suggests possible utility of allene esters as general quenching agents for metathesis reactions. To explore this idea, several representative olefin metathesis reactions, including ring closing, were successfully terminated by the addition of simple allenyl esters for more convenient purification.

  11. 75 FR 27434 - [alpha]-(p-Nonylphenol)-[omega]-hydroxypoly(oxyethylene) Sulfate and Phosphate Esters; Time...

    Science.gov (United States)

    2010-05-17

    ... available for NPEPSDs with respect to plant and animal metabolism/degradation. There is extensive information in the literature on environmental degradation, and some information on bacterial and mammalian metabolism, all of which indicate similar degradation of the NPEPSD compounds. The ethoxylate moiety is...

  12. Potential for beneficial application of sulfate reducing bacteria in sulfate containing domestic wastewater treatment.

    Science.gov (United States)

    van den Brand, T P H; Roest, K; Chen, G H; Brdjanovic, D; van Loosdrecht, M C M

    2015-11-01

    The activity of sulfate reducing bacteria (SRB) in domestic wastewater treatment plants (WWTP) is often considered as a problem due to H2S formation and potential related odour and corrosion of materials. However, when controlled well, these bacteria can be effectively used in a positive manner for the treatment of wastewater. The main advantages of using SRB in wastewater treatment are: (1) minimal sludge production, (2) reduction of potential pathogens presence, (3) removal of heavy metals and (4) as pre-treatment of anaerobic digestion. These advantages are accessory to efficient and stable COD removal by SRB. Though only a few studies have been conducted on SRB treatment of domestic wastewater, the many studies performed on industrial wastewater provide information on the potential of SRB in domestic wastewater treatment. A key-parameter analyses literature study comprising pH, organic substrates, sulfate, salt, temperature and oxygen revealed that the conditions are well suited for the application of SRB in domestic wastewater treatment. Since the application of SRB in WWTP has environmental benefits its application is worth considering for wastewater treatment, when sulfate is present in the influent.

  13. Pathways of sulfate enhancement by natural and anthropogenic mineral aerosols in China

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Xin [Peking Univ., Beijing (China); Song, Yu [Peking Univ., Beijing (China); Zhao, Chun [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Li, Mengmeng [Peking Univ., Beijing (China); Zhu, Tong [Peking Univ., Beijing (China); Zhang, Qiang [Tsinghua Univ., Beijing (China); Zhang, Xiaoye [Chinese Academy of Meteorological Sciences, CMA, Beijing (China)

    2014-12-27

    China, the world’s largest consumer of coal, emits approximately 30 million tons of sulfur dioxide (SO₂) per year. SO₂ is subsequently oxidized to sulfate in the atmosphere. However, large gaps exist between model-predicted and measured sulfate levels in China. Long-term field observations and numerical simulations were integrated to investigate the effect of mineral aerosols on sulfate formation. We found that mineral aerosols contributed a nationwide average of approximately 22% to sulfate production in 2006. The increased sulfate concentration was approximately 2 μg m⁻³ in the entire China. In East China and the Sichuan Basin, the increments reached 6.3 μg m⁻³ and 7.3 μg m⁻³, respectively. Mineral aerosols led to faster SO₂ oxidation through three pathways. First, more SO₂ was dissolved as cloud water alkalinity increased due to water-soluble mineral cations. Sulfate production was then enhanced through the aqueous-phase oxidation of S(IV) (dissolved sulfur in oxidation state +4). The contribution to the national sulfate production was 5%. Second, sulfate was enhanced through S(IV) catalyzed oxidation by transition metals. The contribution to the annual sulfate production was 8%, with 19% during the winter that decreased to 2% during the summer. Third, SO₂ reacts on the surface of mineral aerosols to produce sulfate. The contribution to the national average sulfate concentration was 9% with 16% during the winter and a negligible effect during the summer. The inclusion of mineral aerosols does resolve model discrepancies with sulfate observations in China, especially during the winter. These three pathways, which are not fully considered in most current chemistry-climate models, will significantly impact assessments regarding the effects of aerosol on climate change in China.

  14. Sulfate Salts in Gasoline and Ethanol Fuels -- Historical Perspective and Analysis of Available Data

    Energy Technology Data Exchange (ETDEWEB)

    McCormick, Robert L. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Alleman, Teresa [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Yanowitz, Janet [Ecoengineering, Inc., Sharonville, OH (United States)

    2017-09-21

    This report reviews the chemistry of sulfate salts dissolved in ethanol and gasoline, potential sources of sulfate salts in ethanol and gasoline, the history of consumer vehicle issues with sulfate salt deposits in the early 2000s, and the corresponding changes to the denatured fuel ethanol specification. Recommendations for future research are provided. During a period of rapid market expansion in 2004-05, issues were reported with vehicles running on E10 provided by certain suppliers in some markets. It was commonly believed that these vehicle problems were caused by sulfate salts precipitating from the fuel. Investigators identified sodium sulfate, and in one case also ammonium sulfate, as the predominate salts found in the engines. Several stakeholders believed the issue was excess sulfate ions in the ethanol portion of the E10, and in 2005 the ASTM specification for ethanol (D4806) was modified to include a 4-part per million (ppm) limit on sulfate ions. While there have been no further reports of consumer vehicle issues, the recently approved increase of ethanol in gasoline from 10 to 15 volume percent has resulted in renewed interest in the sulfate ion concentration in fuel ethanol. This report reviews published data on the solubility of sulfate salts in ethanol. The possible sources of sulfate anions and charge balancing cations (such as sodium) in fuel ethanol and petroleum derived blendstocks are discussed. Examination of historical information on the consumer vehicle issues that occurred in 2004-2005 reveals that a source of sodium or ammonium ions, required for the formation of the observed insoluble salts, was never identified. Recommendations for research to better understand sulfate salt solubility issues in ethanol, hydrocarbon blendstocks, and ethanol-gasoline blends are presented.

  15. Methyl esters from vegetable oils with hydroxy fatty acids: Comparison of lesquerella and castor methyl esters

    Science.gov (United States)

    The search for alternative feedstocks for biodiesel as partial replacement for petrodiesel has recently extended to castor oil. In this work, the castor oil methyl esters were prepared and their properties determined in comparison to the methyl esters of lesquerella oil, which in turn is seen as alt...

  16. Depositional ice nucleation on solid ammonium sulfate and glutaric acid particles

    Directory of Open Access Journals (Sweden)

    K. J. Baustian

    2010-03-01

    Full Text Available Heterogeneous ice nucleation on solid ammonium sulfate and glutaric acid particles was studied using optical microscopy and Raman spectroscopy. Optical microscopy was used to detect selective nucleation events as water vapor was slowly introduced into an environmental sample cell. Particles that nucleated ice were dried via sublimation and examined in detail using Raman spectroscopy. Depositional ice nucleation is highly selective and occurred preferentially on just a few ammonium sulfate and glutaric acid particles in each sample. For freezing temperatures between 214 K and 235 K an average ice saturation ratio of S = 1.10±0.07 for solid ammonium sulfate was observed. Over the same temperature range, S values observed for ice nucleation on glutaric acid particles increased from 1.2 at 235 K to 1.6 at 218 K. Experiments with externally mixed particles further show that ammonium sulfate is a more potent ice nucleus than glutaric acid. Our results suggest that heterogeneous nucleation on ammonium sulfate may be an important pathway for atmospheric ice nucleation and cirrus cloud formation when solid ammonium sulfate aerosol particles are available for ice formation. This pathway for ice formation may be particularly significant near the tropical tropopause region where sulfates are abundant and other species known to be good ice nuclei are depleted.

  17. Cellular adhesion responses to the heparin-binding (HepII) domain of fibronectin require heparan sulfate with specific properties

    DEFF Research Database (Denmark)

    Mahalingam, Yashithra; Gallagher, John T; Couchman, John R

    2006-01-01

    Cell surface heparan sulfate (HS) proteoglycans are required in development and postnatal repair. Important classes of ligands for HS include growth factors and extracellular matrix macromolecules. For example, the focal adhesion component syndecan-4 interacts with the III(12-14) region of fibron......Cell surface heparan sulfate (HS) proteoglycans are required in development and postnatal repair. Important classes of ligands for HS include growth factors and extracellular matrix macromolecules. For example, the focal adhesion component syndecan-4 interacts with the III(12-14) region...... required for optimal inhibition. The presence of N-sulfated glucosamine in the HS was essential, whereas 2-O-sulfation of uronic acid or 6-O-sulfation of glucosamine had marginal effects. In the more complex response of focal adhesion formation through syndecan-4, N-sulfates were again required and also...... glucosamine 6-O-sulfate. The significance of polymer N-sulfation and sulfated domains in HS was confirmed by studies with mutant Chinese hamster ovary cells where heparan sulfation was compromised. Finally, focal adhesion formation was absent in fibroblasts synthesizing short HS chains resulting from a gene...

  18. Sulfate Transporters in Dissimilatory Sulfate Reducing Microorganisms: A Comparative Genomics Analysis

    Directory of Open Access Journals (Sweden)

    Angeliki Marietou

    2018-03-01

    Full Text Available The first step in the sulfate reduction pathway is the transport of sulfate across the cell membrane. This uptake has a major effect on sulfate reduction rates. Much of the information available on sulfate transport was obtained by studies on assimilatory sulfate reduction, where sulfate transporters were identified among several types of protein families. Despite our growing knowledge on the physiology of dissimilatory sulfate-reducing microorganisms (SRM there are no studies identifying the proteins involved in sulfate uptake in members of this ecologically important group of anaerobes. We surveyed the complete genomes of 44 sulfate-reducing bacteria and archaea across six phyla and identified putative sulfate transporter encoding genes from four out of the five surveyed protein families based on homology. We did not find evidence that ABC-type transporters (SulT are involved in the uptake of sulfate in SRM. We speculate that members of the CysP sulfate transporters could play a key role in the uptake of sulfate in thermophilic SRM. Putative CysZ-type sulfate transporters were present in all genomes examined suggesting that this overlooked group of sulfate transporters might play a role in sulfate transport in dissimilatory sulfate reducers alongside SulP. Our in silico analysis highlights several targets for further molecular studies in order to understand this key step in the metabolism of SRMs.

  19. Papain-Catalyzed Chemoenzymatic Synthesis of Telechelic Polypeptides Using Bis(Leucine Ethyl Ester) Initiator.

    Science.gov (United States)

    Tsuchiya, Kousuke; Numata, Keiji

    2016-07-01

    In order to construct unique polypeptide architectures, a novel telechelic-type initiator with two leucine ethyl ester units is designed for chemoenzymatic polymerization. Glycine or alanine ethyl ester is chemoenzymatically polymerized using papain in the presence of the initiator, and the propagation occurs at each leucine ethyl ester unit to produce the telechelic polypeptide. The formation of the telechelic polypeptides is confirmed by (1) H NMR and MALDI-TOF mass spectroscopies. It is revealed by AFM observation that long nanofibrils are formed from the telechelic polyalanine, whereas a conventional linear polyalanine with a similar degree of polymerization shows granule-like structures. The telechelic polyglycine and polyalanine show the crystalline structures of Polyglycine II and antiparallel β-sheet, respectively. It is demonstrated that this method to synthesize telechelic-type polypeptides potentially opens up a pathway to construct novel hierarchical structures by self-assembly. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Mechanisms of sulfate removal from subsurface calcium chloride brines: Heletz-Kokhav oilfields, Israel

    Science.gov (United States)

    Gavrieli, Ittai; Starinsky, Avraham; Spiro, Baruch; Aizenshtat, Zeev; Nielsen, Heimo

    1995-09-01

    The evolution of the Ca-chloride brines in the Heletz Formation, Lower Cretaceous, in the southern coastal plain of Israel was reconstructed through the study of its sulfate concentration and isotopic composition. Particular emphasis was given to the brine-oil interaction in the oilfields and to the sulfate depletion and lower SO 4/Cl ratio in brines in contact with hydrocarbons (oil brines) relative to "oil-free" from dry wells in the same oilfields. A method is presented for a calculation of the amount of sulfate removed from the original seawater in the various stages of its evolution to Ca-chloride brine. These stages include evaporation, dolomitization, and sulfate reduction in different stages of its evolution, from early diagenetic processes to the contact with crude oil. In the present study, based on the δ34S SO 4 and SO 4/Cl ratio, it was found that in the Heletz brines most of the sulfate (80-94%) was removed from the original seawater prior to their interaction with the hydrocarbons and only a negligible fraction of few percent of the sulfate was removed during the crude oil-water contact. The Ca-chloride brines evolved from Messinian (Upper Miocene) seawater that underwent evaporation during the desiccation of the Mediterranean. Sulfate was removed from Messinian lagoon (s) during gypsum precipitation due to evaporation and dolomitization. Bacterial sulfate reduction further depleted the brine in sulfate and changed its isotopic composition, from its original Miocene seawater composition of δ34S SO 4 ˜ 20%o, 26%o. Overall, some 50% of the original sulfate, as normalized to chloride, was removed from the original lagoon through the above processes, mostly by gypsum precipitation. Eastward migration of the Messinian Ca-Chloride brine into the Heletz Formation was accompanied by dolomitization of the country rock. Final depletion of sulfate from the brines took place, and possibly still occurs, in the presence of crude oil in the oilfields. The two oil

  1. 21 CFR 182.8997 - Zinc sulfate.

    Science.gov (United States)

    2010-04-01

    ... CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients § 182.8997 Zinc sulfate. (a) Product. Zinc sulfate. (b) Conditions of use. This substance is generally recognized as safe when used in...

  2. Study of ammonium sulfates electric conductivity

    International Nuclear Information System (INIS)

    Dobrynin, D.V.; Tulegulov, A.D.

    2006-01-01

    In the work results of research of ammonium sulfate electroconductivity are given. The influence effecting on ammonium sulfate conductivity is investigated. The various circuits of inclusion tetra ohmmeter are given. (author)

  3. Biliary excretion of phenolphthalein sulfate in rats.

    Science.gov (United States)

    Tanaka, Hiroyuki; Sano, Naoyo; Takikawa, Hajime

    2003-08-01

    Glucuronide and glutathione conjugates have been reported to be substrates of multidrug resistance protein 2 (Mrp2), whereas sulfates of nonbile acid organic anions have never been reported as substrates of Mrp2. To further examine the substrate specificity of Mrp2, we examined the effects of bile acid sulfates on the biliary excretion of phenolphthalein sulfate in rats. The biliary excretion of phenolphthalein sulfate was markedly delayed in Eisai hyperbilirubinemic rats, an Mrp2-deficient strain, and was markedly inhibited by taurolithocholate-3-sulfate. The biliary excretion of leukotriene C(4) metabolites and sulfobromophthalein was inhibited by phenolphthalein sulfate infusion to some extent. These findings suggest that phenolphthalein sulfate is a unique sulfated nonbile acid organic anion which is a substrate of Mrp2. Copyright 2003 S. Karger AG, Basel

  4. Thermodynamic data for modeling acid mine drainage problems: compilation and estimation of data for selected soluble iron-sulfate minerals

    Science.gov (United States)

    Hemingway, Bruch S.; Seal, Robert R.; Chou, I-Ming

    2002-01-01

    Enthalpy of formation, Gibbs energy of formation, and entropy values have been compiled from the literature for the hydrated ferrous sulfate minerals melanterite, rozenite, and szomolnokite, and a variety of other hydrated sulfate compounds. On the basis of this compilation, it appears that there is no evidence for an excess enthalpy of mixing for sulfate-H2O systems, except for the first H2O molecule of crystallization. The enthalpy and Gibbs energy of formation of each H2O molecule of crystallization, except the first, in the iron(II) sulfate - H2O system is -295.15 and -238.0 kJ?mol-1, respectively. The absence of an excess enthalpy of mixing is used as the basis for estimating thermodynamic values for a variety of ferrous, ferric, and mixed-valence sulfate salts of relevance to acid-mine drainage systems.

  5. 21 CFR 524.1484e - Neomycin sulfate and polymyxin B sulfate ophthalmic solution.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Neomycin sulfate and polymyxin B sulfate ophthalmic solution. 524.1484e Section 524.1484e Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... DOSAGE FORM NEW ANIMAL DRUGS § 524.1484e Neomycin sulfate and polymyxin B sulfate ophthalmic solution. (a...

  6. 21 CFR 184.1443 - Magnesium sulfate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Magnesium sulfate. 184.1443 Section 184.1443 Food... Specific Substances Affirmed as GRAS § 184.1443 Magnesium sulfate. (a) Magnesium sulfate (MgSO4·7H2O, CAS... magnesium oxide, hydroxide, or carbonate with sulfuric acid and evaporating the solution to crystallization...

  7. EFFECT OF MAGNESIUM SULFATE (A LAXATIVE) ON ...

    African Journals Online (AJOL)

    use with little success . Magnesium sulfate also known as Epsom salt or bitter salt is a hydrate salt with a chemical name of magnesium sulfate heptahydrate . Chemical formula is MgSO. 7HO and trade name is. Andrews liver salt. Dried magnesium sulfate is an osmotic laxative or a saline laxative that acts by increasing the.

  8. 21 CFR 582.5443 - Magnesium sulfate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Magnesium sulfate. 582.5443 Section 582.5443 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5443 Magnesium sulfate. (a) Product. Magnesium sulfate. (b) Conditions of use. This...

  9. 21 CFR 184.1643 - Potassium sulfate.

    Science.gov (United States)

    2010-04-01

    ... hydroxide or potassium carbonate. (b) The ingredient meets the specifications of the “Food Chemicals Codex... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Potassium sulfate. 184.1643 Section 184.1643 Food... Specific Substances Affirmed as GRAS § 184.1643 Potassium sulfate. (a) Potassium sulfate (K2SO4, CAS Reg...

  10. 21 CFR 182.1125 - Aluminum sulfate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Aluminum sulfate. 182.1125 Section 182.1125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Substances § 182.1125 Aluminum sulfate. (a) Product. Aluminum sulfate. (b) Conditions of use. This substance...

  11. 21 CFR 582.1125 - Aluminum sulfate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Aluminum sulfate. 582.1125 Section 582.1125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1125 Aluminum sulfate. (a) Product. Aluminum sulfate. (b) Conditions of use. This substance...

  12. Modeling and minimization of barium sulfate scale

    Science.gov (United States)

    Alan W. Rudie; Peter W. Hart

    2006-01-01

    The majority of the barium present in the pulping process exits the digester as barium carbonate. Barium carbonate dissolves in the bleach plant when the pH drops below 7 and, if barium and sulfate concentrations are too high, begins to precipitate as barium sulfate. Barium is difficult to control because a mill cannot avoid this carbonate-to-sulfate transition using...

  13. 21 CFR 184.1143 - Ammonium sulfate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ammonium sulfate. 184.1143 Section 184.1143 Food... Specific Substances Affirmed as GRAS § 184.1143 Ammonium sulfate. (a) Ammonium sulfate ((NH4)2SO4, CAS Reg... is prepared by the neutralization of sulfuric acid with ammonium hydroxide. (b) The ingredient meets...

  14. 21 CFR 582.1143 - Ammonium sulfate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ammonium sulfate. 582.1143 Section 582.1143 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1143 Ammonium sulfate. (a) Product. Ammonium sulfate. (b) Conditions of use. This substance...

  15. Sulfate-mediated electrooxidation of X-ray contrast media on boron-doped diamond anode.

    Science.gov (United States)

    Radjenovic, Jelena; Petrovic, Mira

    2016-05-01

    Recently, electrochemical activation of sulfate ions to sulfate radical species and nonradically activated persulfate has been demonstrated at boron-doped diamond (BDD) anode, which enhanced the electrooxidation kinetics of several persistent contaminants. In this study, we investigated the transformation pathways of two X-ray contrast media (ICM), diatrizoate and iopromide, in electrooxidation at BDD anode using sulfate and inert nitrate anolyte. Sulfate anolyte yielded a seven-fold increase in apparent rate constants for ICM oxidation compared to inert nitrate anolyte, and a two-fold increase for the removal of organic carbon. Higher iodine release was observed in electrooxidation of diatrizoate compared to iopromide. In the case of diatrizoate, around 80% of deiodination efficiency was achieved in both anolytes. Deiodination efficiency of iopromide was somewhat lower in nitrate anolyte (≤75%) and significantly reduced in sulfate anolyte (≤46%) due to a larger steric hindrance of alkyl side chains. Moreover, a considerable lag phase of iopromide deiodination was observed in sulfate anolyte, indicating that initial oxidation reactions took place almost exclusively at the alkyl side chains. Several transformation products (TPs) of ICM were identified in electrooxidation in sulfate anolyte, and only three TPs in the case of nitrate anolyte. The main mechanistic steps in the oxidation of iopromide were H-abstraction and bond cleavage in the alkyl side chains. Diatrizoate was mainly transformed through oxidative cleavage of iodine substituent and inter-molecular cyclization. Two hydroxylamine derivatives of iopromide and a nitro-derivative of diatrizoate were observed in sulfate anolyte. These products have not been reported previously for hydroxyl radical-mediated oxidation of ICM. Given that electron-transfer mechanism is more typical for sulfate than for hydroxyl radicals, formation of hydroxylamine and nitro-derivatives of ICM was assigned to one

  16. Zero birefringence films of pullulan ester derivatives

    Science.gov (United States)

    Danjo, Takahiro; Enomoto, Yukiko; Shimada, Hikaru; Nobukawa, Shogo; Yamaguchi, Masayuki; Iwata, Tadahisa

    2017-04-01

    High-performance films with almost zero-birefringence and zero-wavelength dispersion were succeeded to prepare from pullulan esters derivatives (PLEs) without any additives. Optical transmittance analysis, birefringence measurement of PLE cast film and hot stretched films, and infrared dichroism analysis were conducted to characterize optical properties of PLE films comparing with cellulose triacetate which is commercially used as low-birefringence in optical devices. The aims of this study, characterization of optical properties of pullulan esters, can develop a deep understanding of the fundamental knowing and applicability of polysaccharides. Accordingly, authors believe this paper will open the gate for researches in the application of polysaccharides.

  17. Application conditions for ester cured alkaline phenolic resin sand

    Directory of Open Access Journals (Sweden)

    Ren-he Huang

    2016-07-01

    Full Text Available Five organic esters with different curing speeds: propylene carbonate (i.e. high-speed ester A; 1, 4-butyrolactone; glycerol triacetate (i.e. medium-speed ester B; glycerol diacetate; dibasic ester (DBE (i.e. low-speed ester C, were chosen to react with alkaline phenolic resin to analyze the application conditions of ester cured alkaline phenolic resin. The relationships between the curing performances of the resin (including pH value, gel pH value, gel time of resin solution, heat release rate of the curing reaction and tensile strength of the resin sand and the amount of added organic ester and curing temperature were investigated. The results indicated the following: (1 The optimal added amount of organic ester should be 25wt.%-30wt.% of alkaline phenolic resin and it must be above 20wt.%-50 wt.% of the organic ester hydrolysis amount. (2 High-speed ester A (propylene carbonate has a higher curing speed than 1, 4-butyrolactone, and they were both used as high-speed esters. Glycerol diacetate is not a high-speed ester in alkaline phenolic resin although it was used as a high-speed ester in ester cured sodium silicate sand; glycerol diacetate and glycerol triacetate can be used as medium-speed esters in alkaline phenolic resin. (3 High-speed ester A, medium-speed ester B (glycerol triacetate and low-speed ester C (dibasic ester, i.e., DBE should be used below 15 ìC, 35 ìC and 50 ìC, respectively. High-speed ester A or low-speed ester C should not be used alone but mixed with medium-speed ester B to improve the strength of the resin sand. (4 There should be a suitable solid content (generally 45wt.%-65wt.% of resin, alkali content (generally 10wt.%-15wt.% of resin and viscosity of alkaline phenolic resin (generally 50-300 mPa≤s in the preparation of alkaline phenolic resin. Finally, the technique conditions of alkaline phenolic resin preparation and the application principles of organic ester were discussed.

  18. Inhibition of membrane lipid-independent protein kinase Calpha activity by phorbol esters, diacylglycerols, and bryostatin-1.

    Science.gov (United States)

    Slater, S J; Taddeo, F J; Mazurek, A; Stagliano, B A; Milano, S K; Kelly, M B; Ho, C; Stubbs, C D

    1998-09-04

    The activity of membrane-associated protein kinase C (PKC) has previously been shown to be regulated by two discrete high and low affinity binding regions for diacylglycerols and phorbol esters (Slater, S. J., Ho, C., Kelly, M. B., Larkin, J. D., Taddeo, F. J., Yeager, M. D., and Stubbs, C. D. (1996) J. Biol. Chem. 271, 4627-4631). PKC is also known to interact with both cytoskeletal and nuclear proteins; however, less is known concerning the mode of activation of this non-membrane form of PKC. By using the fluorescent phorbol ester, sapintoxin D (SAPD), PKCalpha, alone, was found to possess both low and high affinity phorbol ester-binding sites, showing that interaction with these sites does not require association with the membrane. Importantly, a fusion protein containing the isolated C1A/C1B (C1) domain of PKCalpha also bound SAPD with low and high affinity, indicating that the sites may be confined to this domain rather than residing elsewhere on the enzyme molecule. Both high and low affinity interactions with native PKCalpha were enhanced by protamine sulfate, which activates the enzyme without requiring Ca2+ or membrane lipids. However, this "non-membrane" PKC activity was inhibited by the phorbol ester 4beta-12-O-tetradecanoylphorbol-13-acetate (TPA) and also by the fluorescent analog, SAPD, opposite to its effect on membrane-associated PKCalpha. Bryostatin-1 and the soluble diacylglycerol, 1-oleoyl-2-acetylglycerol, both potent activators of membrane-associated PKC, also competed for both low and high affinity SAPD binding and inhibited protamine sulfate-induced activity. Furthermore, the inactive phorbol ester analog 4alpha-TPA (4alpha-12-O-tetradecanoylphorbol-13-acetate) also inhibited non-membrane-associated PKC. In keeping with these observations, although TPA could displace high affinity SAPD binding from both forms of the enzyme, 4alpha-TPA was only effective at displacing high affinity SAPD binding from non-membrane-associated PKC. 4alpha-TPA also

  19. Particle size distribution and behavior of sulfate aerosols in a coastal region

    Energy Technology Data Exchange (ETDEWEB)

    Fujimura, M.; Hashimoto, Y.

    1979-01-01

    To obtain fundamental knowledge about sulfate aerosols, a field research was conducted in a coastal region distant from industrial pollution sources. The aerosol samples were analyzed for some elements, sulfate and ammonium ions. Sulfate was determined by the turbidimetry with 2-aminoperimidine, and ammonium was by the colorimetry of indophenol method. Trace elements with short-lived nuclides were analyzed by instrumental neutron activation analysis. The mass-size distribution curve of total aerosols was the general bimodal pattern, although the concentration level was very low. Most of sulfate and ammonium salts were distributed in the fine particle range less than 2 microns in aerodynamic diameter, but sulfate had another peak, thought to be of maritime origin, in the coarse particle range. Nevertheless, many fine sulfate particles that had been produced secondarily in the atmosphere were found in such a less polluted coastal region. The change of the sulfate concentrations obtained by the two-stage Andersen type sampler showed a correlation with the humidity. This may suggest that the formation of sulfate aerosols from sulfur dioxide could be related to a catalytic oxidation process in water drops.

  20. Myocardial storage of chondroitin sulfate-containing moieties in Costello syndrome patients with severe hypertrophic cardiomyopathy.

    Science.gov (United States)

    Hinek, Aleksander; Teitell, Michael A; Schoyer, Lisa; Allen, William; Gripp, Karen W; Hamilton, Robert; Weksberg, Rosanna; Klüppel, Michael; Lin, Angela E

    2005-02-15

    Costello syndrome is a distinctive multiple congenital anomaly syndrome, characterized by loose soft skin with deep palmar and plantar creases, loose joints, distinctive coarse facial features, skeletal abnormalities, cardiac abnormalities (cardiovascular malformation (CVM), hypertrophic cardiomyopathy, tachycardia), predisposition to malignancy, developmental delays, and mental retardation. Previous studies with cultured fibroblasts from individuals with Costello syndrome demonstrate excessive accumulation of chondroitin sulfate-bearing proteoglycans, associated with both impaired formation of elastic fibers and an unusually high rate of cellular proliferation. Despite multiple clinical reports of cardiac abnormalities, there has been only one previously published report describing post-mortem findings in hearts from Costello syndrome patients. Here we provide a detailed description of the post-mortem findings of the hearts of three children with Costello syndrome. Routine histological examination and results of targeted histochemical and immunohistochemical studies revealed that in addition to cardiomyocyte hypertrophy, these hearts also demonstrated massive pericellular and intracellular accumulation of chondroitin sulfate-bearing proteoglycans and a marked reduction of elastic fibers. Normal stroma was replaced by multifocal collagenous fibrosis. Most peculiar was the finding that the bulk of the chondroitin sulfate accumulated in these Costello syndrome hearts is a chondroitin-6-sulfate. In contrast, deposition of chondroitin-4 sulfate was below the level detected in normal hearts. We propose that an imbalance in sulfation of chondroitin sulfate molecules and subsequent accumulation of chondroitin-6-sulfate in cardiomyocytes contribute to the development of the hypertrophic cardiomyopathy of Costello syndrome. (c) 2005 Wiley-Liss, Inc.

  1. Sulfate-reducing bacteria and their activities in cyanobacterial mats of Solar Lake (Sinai, Egypt)

    DEFF Research Database (Denmark)

    Teske, A.; Ramsing, NB; Habicht, K.

    1998-01-01

    in variable densities of 10(4) to 106 cells ml(-1). A Desulfonema-related, diurnally migrating bacterium was detected with PCR and denaturing gradient gel electrophoresis within and below the oxic surface layer. Facultative aerobic respiration, filamentous morphology, motility, diurnal migration......, and aggregate formation were the most conspicuous adaptations of Solar Lake sulfate-reducing bacteria to the mat matrix and to diurnal oxygen stress. A comparison of sulfate reduction rates within the mat and previously published photosynthesis rates showed that CO2 from sulfate reduction in the upper 5 mm...

  2. Structure and anticoagulant properties of sulfated glycosaminoglycans from primitive Chordates

    Directory of Open Access Journals (Sweden)

    MAURO S. G. PAVÃO

    2002-03-01

    Full Text Available Dermatan sulfates and heparin, similar to the mammalian glycosaminoglycans, but with differences in the degree and position of sulfation were previously isolated from the body of the ascidian Styela plicata and Ascidia nigra. These differences produce profound effects on their anticoagulant properties. S. plicata dermatan sulfate composed by 2-O-sulfatedalpha-L-iduronic acid and 4-O-sulfated N-acetyl-beta-D-galactosamine residues is a potent anticoagulant due to a high heparin cofactor II activity. Surprisingly, it has a lower potency to prevent thrombus formation on an experimental model and a lower bleeding effect in rats than the mammalian dermatan sulfate. In contrast, A. nigra dermatan sulfate, also enriched in 2-O-sulfated alpha-L-iduronic acid, but in this case sulfated at O-6 of the N-acetyl-beta-D-galactosamine units, has no in vitro or in vivo anticoagulant activity, does not prevent thrombus formation but shows a bleeding effect similar to the mammalian glycosaminoglycan. Ascidian heparin, composed by 2-O-sulfated alpha-L-iduronic acid, N- and 6-O-sulfated glucosamine (75% and alpha-L-iduronic acid, N- and 6-O-sulfated glucosamine (25% disaccharide units has an anticoagulant activity 10 times lower than the mammalian heparin, is about 20 times less potent in the inhibition of thrombin by antithrombin, but has the same heparin cofactor II activity as mammalian heparin.Dermatam sulfato e heparina semelhantes aos glicosaminoglicanos de mamíferos, mas apresentando diferenças no grau e posição de sulfatação foram previamente isolados do corpo das ascídias Styela plicata e Ascidia nigra. Estas diferenças produzem efeitos profundos nas suas propriedades anticoagulantes. O dermatam sulfato de S. plicata, composto por resíduos de ácido alfa-L-idurônico 2-O-sulfatados e N-acetilgalactosamina 4-O-sulfatados é um potente anticoagulante devido a sua alta atividade de cofator II da heparina. Surpreendentemente, este polímero possui uma

  3. Synthesis and stability of new spiroaminoborate esters

    OpenAIRE

    Stepanenko, Viatcheslav; de Jesús, Melvin; Garcia, Carmelo; Barnes, Charles L.; Ortiz-Marciales, Margarita

    2012-01-01

    New spiroaminoborate esters derived from 1,1-diphenylprolinol, ephedrine and dihydroquinine with different alkoxy substituents were prepared as stable crystalline compounds and characterized by spectroscopical analysis and specific rotation. The structure of the spiroborate 4 derived from 1,1-diphenylprolinol and dicyclohexyl-1,1′-diol was confirmed by X-ray analysis.

  4. 1347-IJBCS-Article-Dr Innocent Ester

    African Journals Online (AJOL)

    KODJIO NORBERT

    Say (Culicidae: Diptera). Ester INNOCENT 1*, Eliangiringa KAALE 2 and Zakaria H. MBWAMBO 1. 1 Institute of Traditional Medicine, Muhimbili University of Health and Allied Sciences,. P.O. Box 65001, Dar es Salaam, Tanzania. 2Department of Medicinal Chemistry, School of Pharmacy, Muhimbili University of Health and ...

  5. Two New Phorbol Esters from Euphorbia bothae

    African Journals Online (AJOL)

    NICO

    Euphorbias of South Africa: Two New Phorbol Esters from. Euphorbia bothae. Wendy L. Popplewell,1 Eloise A. Marais,1 Linda Brand,2. Brian H. Harvey2 and Michael T. Davies-Coleman1*. 1Department of Chemistry, Rhodes University, Grahamstown, 6140 South Africa. 2Unit for Drug Research and Development, Division ...

  6. Naturally Occurring Cinnamic Acid Sugar Ester Derivatives

    Directory of Open Access Journals (Sweden)

    Yuxin Tian

    2016-10-01

    Full Text Available Cinnamic acid sugar ester derivatives (CASEDs are a class of natural product with one or several phenylacrylic moieties linked with the non-anomeric carbon of a glycosyl skeleton part through ester bonds. Their notable anti-depressant and brains protective activities have made them a topic of great interest over the past several decades. In particular the compound 3′,6-disinapoylsucrose, the index component of Yuanzhi (a well-known Traditional Chinese Medicine or TCM, presents antidepressant effects at a molecular level, and has become a hotspot of research on new lead drug compounds. Several other similar cinnamic acid sugar ester derivatives are reported in traditional medicine as compounds to calm the nerves and display anti-depression and neuroprotective activity. Interestingly, more than one third of CASEDs are distributed in the family Polygalaceae. This overview discusses the isolation of cinnamic acid sugar ester derivatives from plants, together with a systematic discussion of their distribution, chemical structures and properties and pharmacological activities, with the hope of providing references for natural product researchers and draw attention to these interesting compounds.

  7. Avocado and olive oil methyl esters

    Science.gov (United States)

    Biodiesel, the mono-alkyl esters of vegetable oils, animal fats or other triacylglycerol-containing materials and an alternative to conventional petroleum-based diesel fuel, has been derived from a variety of feedstocks. Numerous feedstocks have been investigated as potential biodiesel sources, incl...

  8. Modeling of Sulfate Double-Salt in Nuclear Wastes

    International Nuclear Information System (INIS)

    Toghiani, B.; Lindner, J.S.; Weber, C.F.; Hunt, R.D.

    2000-01-01

    The Environmental Simulation Program (ESP) continues to adequately predict the solubility of most key chemical systems in the Hanford tank waste. For example, the ESP predictions were in fair agreement with the solubility experiments for the fluoride-phosphate system, although ESP probably underestimates the aqueous amounts. Due to the importance of this system in the formation of pipeline plugs, additional experiments have been made at elevated temperatures, and improvements to the ESP database will be made. ESP encountered problems with sulfate systems because the Public database for ESP does not include anhydrous sodium sulfate in mixed solutions below 32.4 C. This limitation leads to convergence problems and to spurious predictions of solubility near the transition point with sodium sulfate decahydrate when other salts such as sodium nitrate are present. However, ESP was able to make reasonable solubility predictions with a corrected database, demonstrating the need to validate and document the various databases that can be used by ESP. Even though ESP does not include the sulfate-nitrate double salt, this omission does not appear to be a major problem. The solubility predictions with and without the sulfate-nitrate double salt are comparable. In sharp contrast, the sulfate-fluoride double salt is included, but ESP still underestimates solubility in some cases. This problem can misrepresent the ionic strength of the solution, which is an important factor in the formation of pipeline plugs. Solubility tests on the sulfate-fluoride system are planned to provide additional data at higher temperatures and in caustic solutions. These results will be used to improve the range and accuracy of ESP predictions. ESP will continue to provide important predictions for waste processing operations while being evaluated and improved. For example, ESP will be used to determine the amount of water for the saltcake dissolution efforts at Hanford. When ESP underestimates the

  9. Ester Tuiksoo - Eesti esimene naissoost põllumajandusminister / Ester Tuiksoo ; interv. Toomas Verrev

    Index Scriptorium Estoniae

    Tuiksoo, Ester, 1965-

    2007-01-01

    Ametist lahkuv põllumajandusminister Ester Tuiksoo räägib saadud juhtimiskogemusest, Euroopa Liidu ühise põllumajanduspoliitika juurutamisest, rahvuskala valimisest, Rahvaliidu käekäigust parlamendivalimistel

  10. QSAR for cholinesterase inhibition by organophosphorus esters and CNDO/2 calculations for organophosphorus ester hydrolysis

    Science.gov (United States)

    Johnson, H.; Kenley, R. A.; Rynard, C.; Golub, M. A.

    1985-01-01

    Quantitative structure-activity relationships were derived for acetyl- and butyrylcholinesterase inhibition by various organophosphorus esters. Bimolecular inhibition rate constants correlate well with hydrophobic substituent constants, and with the presence or absence of catonic groups on the inhibitor, but not with steric substituent constants. CNDO/2 calculations were performed on a separate set of organophosphorus esters, RR'P(O)X, where R and R' are alkyl and/or alkoxy groups and X is fluorine, chlorine or a phenoxy group. For each subset with the same X, the CNDO-derived net atomic charge at the central phosphorus atom in the ester correlates well with the alkaline hydrolysis rate constant. For the whole set of esters with different X, two equations were derived that relate either charge and leaving group steric bulk, or orbital energy and bond order to the hydrogen hydrolysis rate constant.

  11. Microbial Diversity in Sulfate-Reducing Marine Sediment Enrichment Cultures Associated with Anaerobic Biotransformation of Coastal Stockpiled Phosphogypsum (Sfax, Tunisia).

    Science.gov (United States)

    Zouch, Hana; Karray, Fatma; Armougom, Fabrice; Chifflet, Sandrine; Hirschler-Réa, Agnès; Kharrat, Hanen; Kamoun, Lotfi; Ben Hania, Wajdi; Ollivier, Bernard; Sayadi, Sami; Quéméneur, Marianne

    2017-01-01

    Anaerobic biotechnology using sulfate-reducing bacteria (SRB) is a promising alternative for reducing long-term stockpiling of phosphogypsum (PG), an acidic (pH ~3) by-product of the phosphate fertilizer industries containing high amounts of sulfate. The main objective of this study was to evaluate, for the first time, the diversity and ability of anaerobic marine microorganisms to convert sulfate from PG into sulfide, in order to look for marine SRB of biotechnological interest. A series of sulfate-reducing enrichment cultures were performed using different electron donors (i.e., acetate, formate, or lactate) and sulfate sources (i.e., sodium sulfate or PG) as electron acceptors. Significant sulfide production was observed from enrichment cultures inoculated with marine sediments, collected near the effluent discharge point of a Tunisian fertilizer industry (Sfax, Tunisia). Sulfate sources impacted sulfide production rates from marine sediments as well as the diversity of SRB species belonging to Deltaproteobacteria . When PG was used as sulfate source, Desulfovibrio species dominated microbial communities of marine sediments, while Desulfobacter species were mainly detected using sodium sulfate. Sulfide production was also affected depending on the electron donor used, with the highest production obtained using formate. In contrast, low sulfide production (acetate-containing cultures) was associated with an increase in the population of Firmicutes . These results suggested that marine Desulfovibrio species, to be further isolated, are potential candidates for bioremediation of PG by immobilizing metals and metalloids thanks to sulfide production by these SRB.

  12. Microbial Diversity in Sulfate-Reducing Marine Sediment Enrichment Cultures Associated with Anaerobic Biotransformation of Coastal Stockpiled Phosphogypsum (Sfax, Tunisia

    Directory of Open Access Journals (Sweden)

    Hana Zouch

    2017-08-01

    Full Text Available Anaerobic biotechnology using sulfate-reducing bacteria (SRB is a promising alternative for reducing long-term stockpiling of phosphogypsum (PG, an acidic (pH ~3 by-product of the phosphate fertilizer industries containing high amounts of sulfate. The main objective of this study was to evaluate, for the first time, the diversity and ability of anaerobic marine microorganisms to convert sulfate from PG into sulfide, in order to look for marine SRB of biotechnological interest. A series of sulfate-reducing enrichment cultures were performed using different electron donors (i.e., acetate, formate, or lactate and sulfate sources (i.e., sodium sulfate or PG as electron acceptors. Significant sulfide production was observed from enrichment cultures inoculated with marine sediments, collected near the effluent discharge point of a Tunisian fertilizer industry (Sfax, Tunisia. Sulfate sources impacted sulfide production rates from marine sediments as well as the diversity of SRB species belonging to Deltaproteobacteria. When PG was used as sulfate source, Desulfovibrio species dominated microbial communities of marine sediments, while Desulfobacter species were mainly detected using sodium sulfate. Sulfide production was also affected depending on the electron donor used, with the highest production obtained using formate. In contrast, low sulfide production (acetate-containing cultures was associated with an increase in the population of Firmicutes. These results suggested that marine Desulfovibrio species, to be further isolated, are potential candidates for bioremediation of PG by immobilizing metals and metalloids thanks to sulfide production by these SRB.

  13. Alginate Sulfate-Nanocellulose Bioinks for Cartilage Bioprinting Applications.

    Science.gov (United States)

    Müller, Michael; Öztürk, Ece; Arlov, Øystein; Gatenholm, Paul; Zenobi-Wong, Marcy

    2017-01-01

    One of the challenges of bioprinting is to identify bioinks which support cell growth, tissue maturation, and ultimately the formation of functional grafts for use in regenerative medicine. The influence of this new biofabrication technology on biology of living cells, however, is still being evaluated. Recently we have identified a mitogenic hydrogel system based on alginate sulfate which potently supports chondrocyte phenotype, but is not printable due to its rheological properties (no yield point). To convert alginate sulfate to a printable bioink, it was combined with nanocellulose, which has been shown to possess very good printability. The alginate sulfate/nanocellulose ink showed good printing properties and the non-printed bioink material promoted cell spreading, proliferation, and collagen II synthesis by the encapsulated cells. When the bioink was printed, the biological performance of the cells was highly dependent on the nozzle geometry. Cell spreading properties were maintained with the lowest extrusion pressure and shear stress. However, extruding the alginate sulfate/nanocellulose bioink and chondrocytes significantly compromised cell proliferation, particularly when using small diameter nozzles and valves.

  14. Inconsistency of ammonium-sulfate aerosol ratios with thermodynamic models in the eastern US: a possible role of organic aerosol

    Science.gov (United States)

    Silvern, Rachel F.; Jacob, Daniel J.; Kim, Patrick S.; Marais, Eloise A.; Turner, Jay R.; Campuzano-Jost, Pedro; Jimenez, Jose L.

    2017-04-01

    model and find that we can reproduce both the observed ammonium-sulfate aerosol ratios and the concurrent presence of gas-phase ammonia. If sulfate aerosol becomes more acidic as OA / sulfate ratios increase, then controlling SO2 emissions to decrease sulfate aerosol will not have the co-benefit of suppressing acid-catalyzed secondary organic aerosol (SOA) formation.

  15. Euphorbias of South Africa: Two New Phorbol Esters from ...

    African Journals Online (AJOL)

    Euphorbias of South Africa: Two New Phorbol Esters from Euphorbia bothae. ... WL Popplewell, EA Marais, L Brand, BH Harvey, MT Davies-Coleman. Abstract. Two known phorbol esters, 12-deoxyphorbol-13-isobutyrate-20-acetate (1) and 12-deoxyphorbol-13-(2-methylbutyrate)-20-acetate (2), and two new phorbol esters, ...

  16. Biocatalytic synthesis and antioxidant capacities of ascorbyl esters ...

    African Journals Online (AJOL)

    ajl yemi

    2011-11-28

    Nov 28, 2011 ... available on the comparison of antioxidant activities of ascorbyl esters biosynthesized using alkyl ester, fatty acid and triglyceride as acyl donors. Therefore, this study focused on the enzymatic synthesis of L-ascorbyl acid fatty acid esters catalyzed by immobilized lipase from C. antarctica (Novozym 435) in.

  17. 21 CFR 172.848 - Lactylic esters of fatty acids.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Lactylic esters of fatty acids. 172.848 Section 172... CONSUMPTION Multipurpose Additives § 172.848 Lactylic esters of fatty acids. Lactylic esters of fatty acids... prepared from lactic acid and fatty acids meeting the requirements of § 172.860(b) and/or oleic acid...

  18. 21 CFR 172.859 - Sucrose fatty acid esters.

    Science.gov (United States)

    2010-04-01

    ... solvents which may be used in the preparation of sucrose fatty acid esters are those generally recognized... preparation of sucrose fatty acid esters. (b) Sucrose fatty acid esters meet the following specifications: (1..., 5100 Paint Branch Pkwy., College Park, MD 20740, or available for inspection at the National Archives...

  19. 21 CFR 175.210 - Acrylate ester copolymer coating.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acrylate ester copolymer coating. 175.210 Section... COATINGS Substances for Use as Components of Coatings § 175.210 Acrylate ester copolymer coating. Acrylate ester copolymer coating may safely be used as a food-contact surface of articles intended for packaging...

  20. Activated Sludge Biodegradation of 12 Commercial Phthalate Esters

    OpenAIRE

    O'Grady, Dean P.; Howard, Philip H.; Werner, A. Frances

    1985-01-01

    The activated sludge biodegradability of 12 commercial phthalate esters was evaluated in two test systems: (i) a semicontinuous activated sludge test and (ii) an acclimated 19-day die-away procedure. Both procedures demonstrated that phthalate esters are rapidly biodegraded under activated sludge conditions when loss of the parent phthalate ester (primary degradation) is measured.

  1. Celorbicol, isocelorbicol, and their esters: new sesquiterpenoids from Celastrus orbiculatus

    Energy Technology Data Exchange (ETDEWEB)

    Smith, C.R. Jr. (Dept. of Agriculture, Peoria, IL); Miller, R.W.; Weisleder, D.; Rohwedder, W.K.; Eickman, N.; Clardy, J.

    1976-10-01

    Esters of two new sesquiterpenoid polyalcohols - celorbicol and isocelorbicol - have been isolated from Celastrus orbiculatus. Structures of the parent alcohols have been established by x-ray crystallography, and those of the derived esters have been assigned by NMR spectroscopy. These compounds are structurally related to other polyesters and ester alkaloids from the Celastraceae, all of which are based on the dihydroagarofuran ring system.

  2. Age of Sulfate Methane Transition Zone Determined by Modelling Barium Sulfate Growth

    Science.gov (United States)

    Lin, S.; Wang, W. C.; Lien, K. L.; Liu, C. C.; Fan, L. F.

    2017-12-01

    Methane seep to the sediment/water interface could initiate anaerobic methane oxidation (AOM) with subsequent build up of chemosynthetic community, carbonate, pyrite and a number of other authigenic mineral formation. Determination the duration, sequence and time of methane seeps are keys to understand how methane seep to the environment and degree of alteration to the vicinity area. However, limited method existed in defining time of methane seep since there are some known problems involving typical dating methods, i.e. old carbon on C14 of fossil test or authigenic carbonate, thorium from surrounding matrix on U/Th authigenic carbonate dating. In this study, we have employed barium determination method (Dickens, 2001) to model timing of methane seep at two locations in the South China Sea. Our objective is to compare timing of the barium accumulation near the sulfate methane transition zone (SMTZ) on these two different locations and to seek if a similar mechanism driving the methane seep at two locations far apart. Dissolved barium, total sediment barium and aluminum were measured as well as pore water sulfate, and sediment pyrite concentrations. Time for the barium sulfate accumulation is calculated by: T = C/F, C= ∫ I x p x (1-Ø) Our results show that SMTZ is stabilized at each site for a duration of about 4000-5000 years. AOM process have been active at both sites at about the same time. In conjunction, pyrite also accumulated at a depth near the SMTZ as a result of methane oxidation. This result show that AOM could stay at the SMTZ for a relatively long period of time, on a scale of thousands of years.

  3. Expanding the role of 3-O sulfated heparan sulfate in herpes simplex virus type-1 entry

    International Nuclear Information System (INIS)

    O'Donnell, Christopher D.; Kovacs, Maria; Akhtar, Jihan; Valyi-Nagy, Tibor; Shukla, Deepak

    2010-01-01

    Heparan sulfate (HS) proteoglycans are commonly exploited by multiple viruses for initial attachment to host cells. Herpes simplex virus-1 (HSV-1) is unique because it can use HS for both attachment and penetration, provided specific binding sites for HSV-1 envelope glycoprotein gD are present. The interaction with gD is mediated by specific HS moieties or 3-O sulfated HS (3-OS HS), which are generated by all but one of the seven isoforms of 3-O sulfotransferases (3-OSTs). Here we demonstrate that several common experimental cell lines express unique sets of 3-OST isoforms. While the isoforms 3-OST-3, -5 and -6 were most commonly expressed, isoforms 3-OST-2 and -4 were undetectable in the cell lines examined. Since most cell lines expressed multiple 3-OST isoforms, we addressed the significance of 3-OS HS in HSV-1 entry by down-regulating 2-O-sulfation, a prerequisite for 3-OS HS formation, by knocking down 2-OST expression by RNA interference (RNAi). 2-OST knockdown was verified by reverse-transcriptase PCR and Western blot analysis, while 3-OS HS knockdown was verified by immunofluorescence. Cells showed a significant decrease in viral entry, suggesting an important role for 3-OS HS. Implicating 3-OS HS further, cells knocked down for 2-OST expression also demonstrated decreased cell-cell fusion when cocultivated with effector cells transfected with HSV-1 glycoproteins. Our findings suggest that 3-OS HS may play an important role in HSV-1 entry into many different cell lines.

  4. Antibody recognizing 4-sulfated chondroitin sulfate proteoglycans restores memory in tauopathy-induced neurodegeneration.

    Science.gov (United States)

    Yang, Sujeong; Hilton, Sam; Alves, João Nuno; Saksida, Lisa M; Bussey, Timothy; Matthews, Russell T; Kitagawa, Hiroshi; Spillantini, Maria Grazia; Kwok, Jessica C F; Fawcett, James W

    2017-11-01

    Chondroitin sulfate proteoglycans (CSPGs) are the main active component of perineuronal nets (PNNs). Digestion of the glycosaminoglycan chains of CSPGs with chondroitinase ABC or transgenic attenuation of PNNs leads to prolongation of object recognition memory and activation of various forms of plasticity in the adult central nervous system. The inhibitory properties of the CSPGs depend on the pattern of sulfation of their glycosaminoglycans, with chondroitin 4-sulfate (C4S) being the most inhibitory form. In this study, we tested a number of candidates for functional blocking of C4S, leading to selection of an antibody, Cat316, which specifically recognizes C4S and blocks its inhibitory effects on axon growth. It also partly blocks binding of semaphorin 3A to PNNs and attenuates PNN formation. We asked whether injection of Cat316 into the perirhinal cortex would have the same effects on memory as chondroitinase ABC treatment. We found that masking C4S with the Cat316 antibody extended long-term object recognition memory in normal wild-type mice to 24 hours, similarly to chondroitinase or transgenic PNN attenuation. We then tested Cat316 for restoration of memory in a neurodegeneration model. Mice expressing tau with the P301S mutation showed profound loss of object recognition memory at 4 months of age. Injection of Cat316 into the perirhinal cortex normalized object recognition at 3 hours in P301S mice. These data indicate that Cat316 binding to C4S in the extracellular matrix can restore plasticity and memory in the same way as chondroitinase ABC digestion. Our results suggest that antibodies to C4S could be a useful therapeutic to restore memory function in neurodegenerative disorders. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Upper tropospheric ice sensitivity to sulfate geoengineering

    Science.gov (United States)

    Visioni, Daniele; Pitari, Giovanni; Mancini, Eva

    2017-04-01

    In light of the Paris Agreement which aims to keep global warming under 2 °C in the next century and considering the emission scenarios produced by the IPCC for the same time span, it is likely that to remain below that threshold some kind of geoengineering technique will have to be deployed. Amongst the different methods, the injection of sulfur into the stratosphere has received much attention considering its effectiveness and affordability. Aside from the rather well established surface cooling sulfate geoengineering (SG) would produce, the investigation on possible side-effects of this method is still ongoing. For instance, some recent studies have investigated the effect SG would have on upper tropospheric cirrus clouds, expecially on the homogenous freezing mechanisms that produces the ice particles (Kuebbeler et al., 2012). The goal of the present study is to better understand the effect of thermal and dynamical anomalies caused by SG on the formation of ice crystals via homogeneous freezing by comparing a complete SG simulation with a RCP4.5 reference case and with a number of sensitivity studies where atmospheric temperature changes in the upper tropospheric region are specified in a schematic way as a function of the aerosol driven stratospheric warming and mid-lower tropospheric cooling. These changes in the temperature profile tend to increase atmospheric stabilization, thus decreasing updraft and with it the amount of water vapor available for homogeneous freezing in the upper troposphere. However, what still needs to be assessed is the interaction between this dynamical effect and the thermal effects of tropospheric cooling (which would increase ice nucleation rates) and stratospheric warming (which would probably extend to the uppermost troposphere via SG aerosol gravitational settling, thus reducing ice nucleation rates), in order to understand how they combine together. Changes in ice clouds coverage could be important for SG, because cirrus ice

  6. Poly(ester-anhydride):poly(beta-amino ester) micro- and nanospheres: DNA encapsulation and cellular transfection.

    Science.gov (United States)

    Pfeifer, Blaine A; Burdick, Jason A; Little, Steve R; Langer, Robert

    2005-11-04

    Poly(ester-anhydride) delivery devices allow flexibility regarding carrier dimensions (micro- versus nanospheres), degradation rate (anhydride versus ester hydrolysis), and surface labeling (through the anhydride functional unit), and were therefore tested for DNA encapsulation and transfection of a macrophage P388D1 cell line. Poly(l-lactic acid-co-sebacic anhydride) and poly(l-lactic acid-co-adipic anhydride) were synthesized through melt condensation, mixed with 25 wt.% poly(beta-amino ester), and formulated with plasmid DNA (encoding firefly luciferase) into micro- and nanospheres using a double emulsion/solvent evaporation technique. The micro- and nanospheres were then characterized (size, morphology, zeta potential, DNA release) and assayed for DNA encapsulation and cellular transfection over a range of poly(ester-anhydride) copolymer ratios. Poly(ester-anhydride):poly(beta-amino ester) composite microspheres (6-12 microm) and nanospheres (449-1031 nm), generated with copolymers containing between 0 and 25% total polyanhydride content, encapsulated plasmid DNA (>or=20% encapsulation efficiency). Within this polyanhydride range, poly(adipic anhydride) copolymers provided DNA encapsulation at an increased anhydride content (10%, microspheres; 10-25%, nanospheres) compared to poly(sebacic anhydride) copolymers (1%, microspheres and nanospheres) with cellular transfection correlating with the observed DNA encapsulation.

  7. Rearrangement of beta,gamma-unsaturated esters with thallium trinitrate: synthesis of indans bearing a beta-keto ester moiety

    Directory of Open Access Journals (Sweden)

    Silva Jr. Luiz F.

    2006-01-01

    Full Text Available The rearrangement of beta,gamma-unsaturated esters, such as 2-(3,4-dihydronaphthalen-1-yl-propionic acid ethyl ester, with thallium trinitrate (TTN in acetic acid leads to 3-indan-1-yl-2-methyl-3-oxo-propionic acid ethyl ester in good yield, through a ring contraction reaction. The new indans thus obtained feature a beta-keto ester moiety, which would be useful for further functionalization.

  8. Modeling of ferric sulfate decomposition and sulfation of potassium chloride during grate‐firing of biomass

    DEFF Research Database (Denmark)

    Wu, Hao; Jespersen, Jacob Boll; Jappe Frandsen, Flemming

    2013-01-01

    Ferric sulfate is used as an additive in biomass combustion to convert the released potassium chloride to the less harmful potassium sulfate. The decomposition of ferric sulfate is studied in a fast heating rate thermogravimetric analyzer and a volumetric reaction model is proposed to describe...... the process. The yields of sulfur oxides from ferric sulfate decomposition under boiler conditions are investigated experimentally, revealing a distribution of approximately 40% SO3 and 60% SO2. The ferric sulfate decomposition model is combined with a detailed kinetic model of gas‐phase KCl sulfation...... and a model of K2SO4 condensation to simulate the sulfation of KCl by ferric sulfate addition. The simulation results show good agreements with experiments conducted in a biomass grate‐firing reactor. The results indicate that the SO3 released from ferric sulfate decomposition is the main contributor to KCl...

  9. Spectroscopic investigation of degradation of rapseed oil methyl esters

    International Nuclear Information System (INIS)

    Kampars, V.

    2003-01-01

    Investigation of rapseed oil methyl esters by US VIS and FTIR spectroscopy during the heating at 80 deg C were carried out. The degradation begins immediately after beginning of experiment. The main process at first stage is destroying of carotenoids and oxidation of polyunsaturated fatty acids by forming conjugated polyenes. Between the formation of conjugated triens and destroying of carotenoids exist definite interconnection, but there isn't evidence for the protective activity of carotenoids. As follows from FTIR spectroscopy the increase of carbonyl compounds concentration begins immediately after the start of experiment and continues all the time. Despite to the complex character the peak at 220 nm is only one spectroscopic characteristic with a sharp alteration point and may be used for the fast and simple detection of storage stability of bio diesels. (authors)

  10. Acceleration effect of ionic liquids on polycyclotrimerization of dicyanate esters

    Directory of Open Access Journals (Sweden)

    A. Fainleib

    2016-09-01

    Full Text Available The polycyclotrimerization reaction of dicyanate ester of bisphenol E (DCBE in the presence of varying amounts (from 0.5 to 5 wt% of 1-octyl-3-methylimidazolium tetrafluoroborate ([OMIm][BF4] ionic liquid has been investigated using differential scanning calorimetry (DSC and Fourier transform infrared spectroscopy (FTIR techniques, after a curing stage at 150 °C for 6 h. It is noteworthy that an amount of [OMIm][BF4] as low as 0.5 wt% accelerates dramatically the thermal curing process leading to the formation of a polycyanurate network. The conversion of DCBE increased with increasing [OMIm][BF4] content in the temperature range studied. A reaction mechanism associated with the ionic liquid-catalyzed DCBE polycyclotrimerization is newly proposed via the involvement of a [CN]δ+–[OMIm]δ– complex as a key intermediate.

  11. Use of calcium oxide in palm oil methyl ester production

    Directory of Open Access Journals (Sweden)

    Kulchanat Prasertsit

    2014-04-01

    Full Text Available Introducing an untreated calcium oxide (CaO as a solid heterogeneous catalyst for biodiesel production from palm oil by transesterification was studied in this work. The four studied parameters were methanol to oil molar ratio, CaO catalyst concentration, reaction time, and water content. The results for palm oil show that when the water content is higher than 3%wt and the amount of CaO greater than 7%wt soap formation from saponification occurs. A higher methanol to oil molar ratio requires a higher amount of CaO catalyst to provide the higher product purity. The appropriate methanol to CaO catalyst ratio is about 1.56. Commercial grade CaO gives almost the same results as AR grade CaO. In addition, reusing commercial grade CaO for about 5 to 10 repetitions without catalyst regeneration drops the percentage of methyl ester purity approximately 5 to 10%, respectively.

  12. Efflorescence as a source of hydrated sulfate minerals in valley settings on Mars

    Science.gov (United States)

    Szynkiewicz, Anna; Borrok, David M.; Vaniman, David T.

    2014-05-01

    A distinctive sulfur cycle dominates many geological processes on Mars and hydrated sulfate minerals are found in numerous topographic settings with widespread occurrences on the Martian surface. However, many of the key processes controlling the hydrological transport of sulfur, including sulfur sources, climate and the depositional history that led to precipitation of these minerals, remain unclear. In this paper, we use a model for the formation of sulfate efflorescent salts (Mg-Ca-Na sulfates) in the Rio Puerco watershed of New Mexico, a terrestrial analog site from the semiarid Southwest U.S., to assess the origin and environmental conditions that may have controlled deposition of hydrated sulfates in Valles Marineris on Mars. Our terrestrial geochemical results (δS34 of -36.0 to +11.1‰) show that an ephemeral arid hydrological cycle that mobilizes sulfur present in the bedrock as sulfides, sulfate minerals, and dry/wet atmospheric deposition can lead to widespread surface accumulations of hydrated sulfate efflorescences. Repeating cycles of salt dissolution and reprecipitation appear to be major processes that migrate sulfate efflorescences to sites of surface deposition and ultimately increase the aqueous SO42- flux along the watershed (average 41,273 metric tons/yr). We suggest that similar shallow processes may explain the occurrence of hydrated sulfates detected on the scarps and valley floors of Valles Marineris on Mars. Our estimates of salt mass and distribution are in accord with studies that suggest a rather short-lived process of sulfate formation (minimum rough estimate ∼100 to 1000 years) and restriction by prevailing arid conditions on Mars.

  13. Evolution of aerosol chemistry in Xi'an, inland China, during the dust storm period of 2013 - Part 1: Sources, chemical forms and formation mechanisms of nitrate and sulfate

    Science.gov (United States)

    Wang, G. H.; Cheng, C. L.; Huang, Y.; Tao, J.; Ren, Y. Q.; Wu, F.; Meng, J. J.; Li, J. J.; Cheng, Y. T.; Cao, J. J.; Liu, S. X.; Zhang, T.; Zhang, R.; Chen, Y. B.

    2014-11-01

    A total suspended particulate (TSP) sample was collected hourly in Xi'an, an inland megacity of China near the Loess Plateau, during a dust storm event of 2013 (9 March 18:00-12 March 10:00 LT), along with a size-resolved aerosol sampling and an online measurement of PM2.5. The TSP and size-resolved samples were determined for elemental carbon (EC), organic carbon (OC), water-soluble organic carbon (WSOC) and nitrogen (WSON), inorganic ions and elements to investigate chemistry evolution of dust particles. Hourly concentrations of Cl-, NO3-, SO42-, Na+ and Ca2+ in the TSP samples reached up to 34, 12, 180, 72 and 28 μg m-3, respectively, when dust peak arrived over Xi'an. Chemical compositions of the TSP samples showed that during the whole observation period NH4+ and NO3- were linearly correlated with each other (r2=0.76) with a molar ratio of 1 : 1, while SO42- and Cl- were well correlated with Na+, Ca2+, Mg2+ and K+ (r2 > 0.85). Size distributions of NH4+ and NO3- presented a same pattern, which dominated in the coarse mode (> 2.1 μm) during the event and predominated in the fine mode (analysis further indicated that SO42- and Cl- in the dust samples possibly exist as Na2SO4, CaSO4 and NaCl, which directly originated from Gobi desert surface soil, while NH4+ and NO3- in the dust samples exist as NH4NO3. We propose a mechanism to explain these observations in which aqueous phase of dust particle surface is formed via uptake of water vapor by hygroscopic salts such as Na2SO4 and NaCl, followed by heterogeneous formation of nitrate on the liquid phase and subsequent absorption of ammonia. Our data indicate that 54 ± 20% and 60 ± 23% of NH4+ and NO3- during the dust period were secondarily produced via this pathway, with the remaining derived from the Gobi desert and Loess Plateau, while SO42- in the event almost entirely originated from the desert regions. Such cases are different from those in the East Asian continental outflow region, where during Asia dust

  14. Efflorescent sulfates from Baia Sprie mining area (Romania) — Acid mine drainage and climatological approach

    Energy Technology Data Exchange (ETDEWEB)

    Buzatu, Andrei, E-mail: andrei.buzatu@uaic.ro [“Alexandru Ioan Cuza” University of Iaşi, Department of Geology, 20A Carol I Blv., 700505 Iaşi (Romania); Dill, Harald G. [Gottfried Wilhelm Leibniz University, Welfengarten 1 D-30167, Hannover (Germany); Buzgar, Nicolae [“Alexandru Ioan Cuza” University of Iaşi, Department of Geology, 20A Carol I Blv., 700505 Iaşi (Romania); Damian, Gheorghe [Technical University Cluj Napoca, North University Center of Baia Mare, 62A Dr. Victor Babeş Street, 430083 Baia Mare (Romania); Maftei, Andreea Elena; Apopei, Andrei Ionuț [“Alexandru Ioan Cuza” University of Iaşi, Department of Geology, 20A Carol I Blv., 700505 Iaşi (Romania)

    2016-01-15

    The Baia Sprie epithermal system, a well-known deposit for its impressive mineralogical associations, shows the proper conditions for acid mine drainage and can be considered a general example for affected mining areas around the globe. Efflorescent samples from the abandoned open pit Minei Hill have been analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman and near-infrared (NIR) spectrometry. The identified phases represent mostly iron sulfates with different hydration degrees (szomolnokite, rozenite, melanterite, coquimbite, ferricopiapite), Zn and Al sulfates (gunningite, alunogen, halotrichite). The samples were heated at different temperatures in order to establish the phase transformations among the studied sulfates. The dehydration temperatures and intermediate phases upon decomposition were successfully identified for each of mineral phases. Gunningite was the single sulfate that showed no transformations during the heating experiment. All the other sulfates started to dehydrate within the 30–90 °C temperature range. The acid mine drainage is the main cause for sulfates formation, triggered by pyrite oxidation as the major source for the abundant iron sulfates. Based on the dehydration temperatures, the climatological interpretation indicated that melanterite formation and long-term presence is related to continental and temperate climates. Coquimbite and rozenite are attributed also to the dry arid/semi-arid areas, in addition to the above mentioned ones. The more stable sulfates, alunogen, halotrichite, szomolnokite, ferricopiapite and gunningite, can form and persists in all climate regimes, from dry continental to even tropical humid. - Highlights: • Efflorescent salts from mining areas have a great impact on the environment. • Secondary minerals are influenced by geology, hydrology, biology and climate. • AMD-precipitates samples were analyzed by XRD, SEM, Raman and NIR spectrometry. • The dehydration temperatures

  15. Real-Time monitoring of intracellular wax ester metabolism

    Directory of Open Access Journals (Sweden)

    Karp Matti

    2011-09-01

    Full Text Available Abstract Background Wax esters are industrially relevant molecules exploited in several applications of oleochemistry and food industry. At the moment, the production processes mostly rely on chemical synthesis from rather expensive starting materials, and therefore solutions are sought from biotechnology. Bacterial wax esters are attractive alternatives, and especially the wax ester metabolism of Acinetobacter sp. has been extensively studied. However, the lack of suitable tools for rapid and simple monitoring of wax ester metabolism in vivo has partly restricted the screening and analyses of potential hosts and optimal conditions. Results Based on sensitive and specific detection of intracellular long-chain aldehydes, specific intermediates of wax ester synthesis, bacterial luciferase (LuxAB was exploited in studying the wax ester metabolism in Acinetobacter baylyi ADP1. Luminescence was detected in the cultivation of the strain producing wax esters, and the changes in signal levels could be linked to corresponding cell growth and wax ester synthesis phases. Conclusions The monitoring system showed correlation between wax ester synthesis pattern and luminescent signal. The system shows potential for real-time screening purposes and studies on bacterial wax esters, revealing new aspects to dynamics and role of wax ester metabolism in bacteria.

  16. Analysis of tyrosine-O-sulfation

    DEFF Research Database (Denmark)

    Bundgaard, J.R.; Sen, J.W.; Johnsen, A.H.

    2008-01-01

    Tyrosine O-sulfation was first described about 50 years ago as a post-translational modification of fibrinogen. In the following 30 years it was considered to be a rare modification affecting only a few proteins and peptides. However, in the beginning of the 1980s tyrosine (Tyr) sulfation was shown...... to be a common modification and since then an increasing number of proteins have been identified as sulfated. The target proteins belong to the classes of secretory, plasma membrane, and lysosomal proteins, which reflects the intracellular localization of the enzymes catalyzing Tyr sulfation, the tyrosylprotein...... sulfotransferases (TPSTs).Traditionally, Tyr sulfation has been analyzed by incorporation of radiolabeled sulfate into target cells followed by purification of the target protein. Subsequently, the protein is degraded enzymatically or by alkaline hydrolysis followed by thin-layer electrophoresis to demonstrate...

  17. Analysis of tyrosine-O-sulfation

    DEFF Research Database (Denmark)

    Bundgaard, J.R.; Sen, J.W.; Johnsen, A.H.

    2008-01-01

    to be a common modification and since then an increasing number of proteins have been identified as sulfated. The target proteins belong to the classes of secretory, plasma membrane, and lysosomal proteins, which reflects the intracellular localization of the enzymes catalyzing Tyr sulfation, the tyrosylprotein......Tyrosine O-sulfation was first described about 50 years ago as a post-translational modification of fibrinogen. In the following 30 years it was considered to be a rare modification affecting only a few proteins and peptides. However, in the beginning of the 1980s tyrosine (Tyr) sulfation was shown...... sulfotransferases (TPSTs).Traditionally, Tyr sulfation has been analyzed by incorporation of radiolabeled sulfate into target cells followed by purification of the target protein. Subsequently, the protein is degraded enzymatically or by alkaline hydrolysis followed by thin-layer electrophoresis to demonstrate...

  18. Structure of cobalt sulfate tetrahydrate

    International Nuclear Information System (INIS)

    Kellersohn, T.

    1992-01-01

    Cobalt(II) sulfate tetrahydrate-d 8 , CoSO 4 -4D 2 O, mineralogical name aplowite, monoclinic, P2 1 /n a = 5.952 (1), b = 13.576 (2), c = 7.908 (1) A. The title compound belongs to the rozenite group of minerals. The characteristic structural units are [Co 2 (SO 4 ) 2 (D 2 O) 8 ] heteropolyhedral clusters which are linked by hydrogen bonds of medium strength. One of the water molecules is very asymmetrically bonded, with one H (D) atom being involved in a long bifurcated hydrogen bond. (orig.)

  19. Uranium sorption from sulfate solutions by polyampholytes

    International Nuclear Information System (INIS)

    Rychkov, V.N.

    2003-01-01

    Uranium sorption from sulfate solutions by aminocarboxylic and aminophosphoric acid polyampholytes is studied. Effect of concentration of sulfuric acid, ammonium sulfate, ph value of solution and concentration of metal in solution on uranium absorptivity by ampholytes is studied. It is determined that sorption process is described satisfactorily by K d =KC p Z equation. Basing on calculated data on uranium ion state in sulfate solutions, analysis of results and data of IR spectroscopy conclusions about uranium sorption process mechanism are made [ru

  20. Enzymatic synthesizing of phytosterol oleic esters.

    Science.gov (United States)

    Pan, Xinxin; Chen, Biqiang; Wang, Juan; Zhang, Xinzhi; Zhul, Biyun; Tan, Tianwei

    2012-09-01

    A method of synthesizing the phytosterol esters from oleic acid and sterols was studied, using immobilized lipase Candida sp. 99-125 as catalyst. Molar ratio (oleic acid/phytosterols), temperature, reaction period, organic solvents, catalyst, and silica-gel drier were optimized, and the result showed that 93.4% of the sterols had been esterified under the optimal synthetic condition: the molar ratio of oleic acid/phytosterol is 1:1 in 10 mL iso-octane, immobilized lipase (w, 140% of the sterols), incubated in an orbital shaker (200 rpm) at a temperature of 45 °C for 24 h. The immobilized lipase could be reused for at least 13 times with limited loss of esterification activity. The conversion still maintained up to 86.6%. Hence, this developed process for synthesizing phytosterol esters could be considered as simple and low-energy consumption compared to existing chemical processes.

  1. Naturally occurring antifungal aromatic esters and amides

    International Nuclear Information System (INIS)

    Ali, M.S.; Shahnaz; Tabassum, S.; Ogunwande, I.A.; Pervez, M.K.

    2010-01-01

    During the search of antifungal natural products from terrestrial plants, a new long chained aromatic ester named grandiflorate along with spatazoate from Portulaca grandiflora and N-[2-methoxy-2-(4-methoxyphenyl) ethyl]-trans-cinnamide and aegeline from Solanum erianthum of Nigeria were isolated and tested against six fungal species. The known constituents have not been reported so far from mentioned investigated plants. Structures of the isolated compounds were elucidated with the aid of spectroscopic techniques including two dimensional NMR experiments. Among the compounds, the esters found more potent than amides against Candida albicans and Aspergillus flavus. The new compound grandiflorate gave response against all tested fungal species while aegeline was found to give lowest inhibition during this study. (author)

  2. Temperature-dependent variations in sulfate-reducing communities associated with a terrestrial hydrocarbon seep.

    Science.gov (United States)

    Cheng, Ting-Wen; Lin, Li-Hung; Lin, Yue-Ting; Song, Sheng-Rong; Wang, Pei-Ling

    2014-01-01

    Terrestrial hydrocarbon seeps are an important source of naturally emitted methane over geological time. The exact community compositions responsible for carbon cycling beneath these surface features remain obscure. As sulfate reduction represents an essential process for anoxic organic mineralization, this study collected muddy fluids from a high-temperature hydrocarbon seep in Taiwan and analyzed community structures of sulfate-supplemented sediment slurries incubated anoxically at elevated temperatures. The results obtained demonstrated that sulfate consumption occurred between 40°C and 80°C. Dominant potential sulfate reducers included Desulfovibrio spp., Desulfonatronum spp., Desulforhabdus spp., and Desulfotomaculum spp. at 40°C, Thermodesulfovibrio spp. at 50°C, Thermodesulfovibrio spp. and Thermacetogenium spp. at 60°C, Thermacetogenium spp. and Archaeoglobus spp. at 70°C, and Archaeoglobus spp. at 80°C. None of these potential sulfate reducers exceeded 7% of the community in the untreated sample. Since no exogenous electron donor was provided during incubation, these sulfate reducers appeared to rely on the degradation of organic matter inherited from porewater and sediments. Aqueous chemistry indicated that fluids discharged in the region represented a mixture of saline formation water and low-salinity surface water; therefore, these lines of evidence suggest that deeply-sourced, thermophilic and surface-input, mesophilic sulfate-reducing populations entrapped along the subsurface fluid transport could respond rapidly once the ambient temperature is adjusted to a range close to their individual optima.

  3. Synthesis of Dipeptide Benzoylalanylglycine Methyl Ester and Corrosion Inhibitor Evaluation by Tafel Equation

    International Nuclear Information System (INIS)

    Abdurrahman, J.; Wahyuningrum, D.; Achmad, S.; Bundjali, B.

    2011-01-01

    Corrosion is one of the major problems in petroleum mining and processing industry. The pipelines used to transport crude oil from reservoir to the processing installation were made from carbon steel that is susceptible towards corrosion. One of the best methods to prevent corrosion that occurred at the inner parts of carbon steel pipelines is to use organic corrosion inhibitor. One of the potent organic corrosion inhibitors is amino acids derivatives. In this study, dipeptide compound namely benzoylalanylglycine methyl ester and benzoylalanylglycine have been synthesized. The structure elucidation of the products was performed by IR, MS and NMR spectroscopy. The determination of corrosion inhibition activity utilized the Tafel method. The corrosion inhibition efficiency of glycine methyl ester, benzoyl alanine, dipeptide benzoylalanylglycine methyl ester and dipeptide benzoylalanylglycine were 63.34 %, 35.86 %, 68.40 % and 27.72 %, respectively. These results showed that the formation of dipeptide benzoylalanylglycine methyl ester, derived from carboxylic protected glycine and amine protected alanine, increased the corrosion inhibition activity due to the loss of acidity center in the structure of glycine and L-alanine that would induce the corrosive environment towards carbon steel. (author)

  4. Fermentation-Guided Natural Products Isolation of a Grape Berry Triacylglyceride that Enhances Ethyl Ester Production

    Directory of Open Access Journals (Sweden)

    Christopher L. Blackford

    2018-01-01

    Full Text Available A full understanding of the origin, formation and degradation of volatile compounds that contribute to wine aroma is required before wine style can be effectively managed. Fractionation of grapes represents a convenient and robust method to simplify the grape matrix to enhance our understanding of the grape contribution to volatile compound production during yeast fermentation. In this study, acetone extracts of both Riesling and Cabernet Sauvignon grape berries were fractionated and model wines produced by spiking aliquots of these grape fractions into model grape juice must and fermented. Non-targeted SPME-GCMS analyses of the wines showed that several medium chain fatty acid ethyl esters were more abundant in wines made by fermenting model musts spiked with certain fractions. Further fractionation of the non-polar fractions and fermentation of model must after addition of these fractions led to the identification of a mixture of polyunsaturated triacylglycerides that, when added to fermenting model must, increase the concentration of medium chain fatty acid ethyl esters in wines. Dosage-response fermentation studies with commercially-available trilinolein revealed that the concentration of medium chain fatty acid ethyl esters can be increased by the addition of this triacylglyceride to model musts. This work suggests that grape triacylglycerides can enhance the production of fermentation-derived ethyl esters and show that this fractionation method is effective in segregating precursors or factors involved in altering the concentration of fermentation volatiles.

  5. Methyl and ethyl soybean esters production

    Energy Technology Data Exchange (ETDEWEB)

    Pighinelli, Anna Leticia Montenegro Turtelli; Park, Kil Jin; Zorzeto, Thais Queiroz [Universidade Estadual de Campinas (FEAGRI/UNICAMP), SP (Brazil). Fac. de Engenharia Agricola], E-mail: annalets@feagri.unicamp.br; Bevilaqua, Gabriela [Universidade Estadual de Campinas (IQ/UNICAMP), SP (Brazil). Inst. de Quimica

    2008-07-01

    Biodiesel is a fuel obtained from triglycerides found in nature, like vegetable oils and animal fats. Nowadays it has been the subject of many researches impulses by the creation of the Brazilian law that determined the blend of 2% of biodiesel with petrodiesel. Basically, there are no limitations on the oilseed type for chemical reaction, but due to high cost of this major feedstock, it is important to use the grain that is available in the region of production. Soybean is the oilseed mostly produced in Brazil and its oil is the only one that is available in enough quantity to supply the current biodiesel demand. The objective of this work was to study the effects of reaction time and temperature on soybean oil transesterification reaction with ethanol and methanol. A central composite experimental design with five variation levels was used and response surface methodology applied for the data analysis. The statistical analysis of the results showed that none of the factors affected the ethyl esters production. However, the methyl esters production suffered the influence of temperature (linear effect), reaction time (linear and quadratic) and interaction of these two variables. None of the generated models showed significant regression consequently it was not possible to build the response surface. The experiments demonstrated that methanol is the best alcohol for transesterification reactions and the ester yield was up to 85%. (author)

  6. Significant role of organic sulfur in supporting sedimentary sulfate reduction in low-sulfate environments

    Science.gov (United States)

    Fakhraee, Mojtaba; Li, Jiying; Katsev, Sergei

    2017-09-01

    Dissimilatory sulfate reduction (DSR) is a major carbon mineralization pathway in aquatic sediments, soils, and groundwater, which regulates the production of hydrogen sulfide and the mobilization rates of biologically important elements such as phosphorus and mercury. It has been widely assumed that water-column sulfate is the main sulfur source to fuel this reaction in sediments. While this assumption may be justified in high-sulfate environments such as modern seawater, we argue that in low-sulfate environments mineralization of organic sulfur compounds can be an important source of sulfate. Using a reaction-transport model, we investigate the production of sulfate from sulfur-containing organic matter for a range of environments. The results show that in low sulfate environments (50%) of sulfate reduction. In well-oxygenated systems, porewater sulfate profiles often exhibit sub-interface peaks so that sulfate fluxes are directed out of the sediment. Our measurements in Lake Superior, the world's largest lake, corroborate this conclusion: offshore sediments act as sources rather than sinks of sulfate for the water column, and sediment DSR is supported entirely by the in-sediment production of sulfate. Sulfate reduction rates are correlated to the depth of oxygen penetration and strongly regulated by the supply of reactive organic matter; rate co-regulation by sulfate availability becomes appreciable below 500 μM level. The results indicate the need to consider the mineralization of organic sulfur in the biogeochemical cycling in low-sulfate environments, including several of the world's largest freshwater bodies, deep subsurface, and possibly the sulfate-poor oceans of the Early Earth.

  7. Consecutive visible-light photoredox decarboxylative couplings of adipic acid active esters with alkynyl sulfones leading to cyclic compounds.

    Science.gov (United States)

    Li, Jingjing; Tian, Hua; Jiang, Min; Yang, Haijun; Zhao, Yufen; Fu, Hua

    2016-07-07

    Novel and efficient consecutive photoredox decarboxylative couplings of adipic acid active esters (bis(1,3-dioxoisoindolin-2-yl)-substituted hexanedioates) with substituted 1-(2-arylethynylsulfonyl)benzenes have been developed under visible-light photocatalysis. The successive photoredox decarboxylative C-C bond formation at room temperature afforded the corresponding cyclic compounds in good yields with tolerance of some functional groups.

  8. Impacts of Four SO2 Oxidation Pathways on Wintertime Sulfate Concentrations

    Science.gov (United States)

    Sarwar, G.; Fahey, K.; Zhang, Y.; Kang, D.; Mathur, R.; Xing, J.; Wei, C.; Cheng, Y.

    2017-12-01

    Air quality models tend to under-estimate winter-time sulfate concentrations compared to observed data. Such under-estimations are particularly acute in China where very high concentrations of sulfate have been measured. Sulfate is produced by oxidation of sulfur dioxide (SO2) in gas-phase by hydroxyl radical and in aqueous-phase by hydrogen peroxide, ozone, etc. and most air quality models employ such typical reactions. Several additional SO2 oxidation pathways have recently been proposed. Heterogeneous reaction on dust has been suggested to be an important sink for SO2. Oxidation of SO2 on fine particles in presence of nitrogen dioxide (NO2) and ammonia (NH3) at high relative humidity has been implicated for sulfate formation in Chinese haze and London fog. Reactive nitrogen chemistry in aerosol water has also been suggested to produce winter-time sulfate in China. Specifically, high aerosol water can trap SO2 which can be subsequently oxidized by NO2 to form sulfate. Aqueous-phase (in-cloud) oxidation of SO2 by NO2 can also produce sulfate. Here, we use the hemispheric Community Multiscale Air Quality (CMAQ) modeling system to examine the potential impacts of these SO2 oxidation pathways on sulfate formation. We use anthropogenic emissions from the Emissions Database for Global Atmospheric Research and biogenic emissions from Global Emissions InitiAtive. We performed simulations without and with these SO2 oxidation pathways for October-December of 2014 using meteorological fields obtained from the Weather Research and Forecasting model. The standard CMAQ model contains one gas-phase chemical reaction and five aqueous-phase chemical reactions for SO2 oxidation. We implement four additional SO2 oxidation pathways into the CMAQ model. Our preliminary results suggest that the dust chemistry enhances mean sulfate over parts of China and Middle-East, the in-cloud SO2 oxidation by NO2 enhances sulfate over parts of western Europe, oxidation of SO2 by NO2 and NH3 on

  9. Insights Into the Aqueous History of Mars from Acid-Sulfate Weathered Phyllosilicates

    Science.gov (United States)

    Craig, P. I.; Ming, D. W.; Rampe, E. B.; Morris, R. V.

    2016-01-01

    Phyllosilicates on Mars are thought to have formed during Mars' earliest Noachian geologic era (approx. 4.1-3.7 Ga). Sulfate formation, on the other hand, requires more acidic conditions which are thought to have occurred later during Mars' Hesperian era (approx. 3.7-3.0 Ga). Therefore, regions on Mars where phyllosilicates and sulfates are found in close proximity to each other provide evidence for the aqueous conditions during this global transition. Both phyllosilicates and sulfates form in the presence of water and thus give clues to the aqueous history of Mars and its potential for habitability. Phyllosilicates that formed during the Noachian era would have been weathered by the prevailing acidic conditions that define the Hesperian. Therefore, the purpose of this study is to characterize the alteration products of acid-sulfate weathered phyllosilicates in laboratory experiments, focusing on the Fe/Mg-smectites commonly identified on Mars. We also compare our results to observations of phyllosilicates and sulfates on Mars in regions such as Endeavour Crater and Mawrth Vallis to understand the formation process of sulfates and constrain the aqueous history of these regions.

  10. Algae as an electron donor promoting sulfate reduction for the bioremediation of acid rock drainage.

    Science.gov (United States)

    Ayala-Parra, Pedro; Sierra-Alvarez, Reyes; Field, Jim A

    2016-11-05

    This study assessed bioremediation of acid rock drainage in simulated permeable reactive barriers (PRB) using algae, Chlorella sorokiniana, as the sole electron donor for sulfate-reducing bacteria. Lipid extracted algae (LEA), the residues of biodiesel production, were compared with whole cell algae (WCA) as an electron donor to promote sulfate-reducing activity. Inoculated columns containing anaerobic granular sludge were fed a synthetic medium containing H2SO4 and Cu(2+). Sulfate, sulfide, Cu(2+) and pH were monitored throughout the experiment of 123d. Cu recovered in the column packing at the end of the experiment was evaluated using sequential extraction. Both WCA and LEA promoted 80% of sulfate removal (12.7mg SO4(2-) d(-1)) enabling near complete Cu removal (>99.5%) and alkalinity generation raising the effluent pH to 6.5. No noteworthy sulfate reduction, alkalinity formation and Cu(2+) removal were observed in the endogenous control. In algae amended-columns, Cu(2+) was precipitated with biogenic H2S produced by sulfate reduction. Formation of CuS was evidenced by sequential extraction and X-ray diffraction. LEA and WCA provided similar levels of electron donor based on the COD balance. The results demonstrate an innovative passive remediation system using residual algae biomass from the biodiesel industry. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Purification and Properties of a Glycerol Ester Hydrolase (Lipase) from Propionibacterium shermanii

    Science.gov (United States)

    Oterholm, Anders; Ordal, Z. John; Witter, Lloyd D.

    1970-01-01

    An intracellular glycerol ester hydrolase (lipase) from Propionibacterium shermanii was recovered from cell-free extracts and purified by ammonium sulfate precipitation, gel filtration, and ion-exchange chromatography on diethylaminoethylcellulose. Maximum enzyme activity was observed at pH 7.2 and 47 C when an emulsion of tributyrin was used as substrate. The enzyme was stable between pH 5.5 and 8. Heating the enzyme solution at 45 C for 10 min resulted in a 75% decrease in activity. Maximum rate of hydrolysis of triglycerides was observed on tripropionin, followed in order by tributyrin, tricaproin, and tricaprylin. The lipase was strongly inhibited by mercury and arsenicals, but specific sulfhydryl reagents had little or no inhibiting effect on the enzyme activity. The enzyme also showed some esterase activity, but the hydrolysis of substrates in solution was small as compared to the hydrolysis of substrates in emulsion. PMID:5456938

  12. [Effect of ammonium sulfate aerosol on the photochemical reaction of toluene/ NO(x)/air mixture].

    Science.gov (United States)

    Wu, Shan; Hao, Ji-Ming; Lü, Zi-Feng; Zhao, Zhe; Li, Jun-Hua

    2007-06-01

    The effect of ammonium sulfate aerosol on the photochemical reaction of toluene/NO(x)/air mixture was evaluated with Tsinghua Smog Chamber facility. The results indicate that the presence of concentrated preexisting ammonium sulfate aerosol shortens the time to reach maximum PM (particle matter) concentration and increases the aerosol yield of toluene. And under the presence of high concentrated ammonium sulfate aerosol seed, the concentration of aerosol does not have significant effects on NO(x), NO and O3 variation, but affects the formation of secondary organic aerosol (SOA). The SOA yield increases with the increasing initial ammonium sulfate seed concentration (< 160 microg x m(-3)). From the minimum 7.2% to the maximum 11.7%, the percentage increase of SOA yield is more than 60%.

  13. Structural analysis of a sulfated polysaccharidic fraction obtained from the coenocytic green seaweed Caulerpa cupressoides var. lycopodium

    Directory of Open Access Journals (Sweden)

    José Ariévilo Gurgel Rodrigues

    2014-04-01

    Full Text Available Researches on structural chemistry of sulfated polysaccharides (SPs have been mainly focused on red and brown algae. Caulerpa cupressoides var. lycopodium (Chlorophyta contains three SPs fractions (Cc-SP1, Cc-SP2 and Cc-SP3. Cc-SP1 and Cc-SP2 had anticoagulant (in vitro and anti- and prothrombotic, antinociceptive and/or anti-inflammatory (in vivo effects. However, their structural features have not yet been investigated. This study analyzed the chemical composition, elemental microanalysis and structural features by infrared (IR and nuclear magnetic resonance (1H NMR spectroscopy of Cc-SPs. Fractionation of SPs by DEAE-cellulose yielded Cc-SP1, Cc-SP2 and CcSP3 containing differences among the relative proportions of sulfate (14.67-26.72%, total sugars (34.92-49.73% and uronic acid (7.15-7.22%. Carbon (21.76-29.62%, sulfate (2.16-4.55%, nitrogen (0.85-1.57% and hydrogen (4.57-5.86% contents were obtained using a CHN equipment. Data from IR indicated occurrence of sulfate ester, galactose-6-sulfate, uronic acid and glycoside linkages. For 1H NMR spectrum of the soluble Cc-SP1 fraction, it was mainly found β-galactopyranose residues and CH3 group. The results showed that Cc-SPs fractions have some structural features similar to others studied Caulerpaceae SPs.

  14. Observations of linear dependence between sulfate and nitrate in atmospheric particles

    Science.gov (United States)

    Kong, Lingdong; Yang, Yiwei; Zhang, Shuanqin; Zhao, Xi; Du, Huanhuan; Fu, Hongbo; Zhang, Shicheng; Cheng, Tiantao; Yang, Xin; Chen, Jianmin; Wu, Dui; Shen, Jiandong; Hong, Shengmao; Jiao, Li

    2014-01-01

    Hourly measurements of water-soluble inorganic ionic species in ambient atmospheric particles were conducted at Shanghai, Hangzhou, and Guangzhou sampling sites in China during the period of 2009-2011. The relation between sulfate and nitrate in particulate matter (PM10 and PM2.5) was examined based on these measurements. Results showed that the mass fraction of sulfate was strongly negatively correlated with that of nitrate in atmospheric particles on most of the sampling days, especially when sulfate and nitrate made up the vast majority of the total soluble anions and cations (Na+, K+, Ca2+, and Mg2+) made a small contribution to the total water-soluble ions, revealing that the formation mechanisms of sulfate and nitrate in the atmosphere are highly correlated, and there exists a significant negative correlation trend between sulfate and nitrate mass fractions in the atmospheric particles. We found that local meteorological conditions presented opposite influences on the mass fractions of sulfate and nitrate. Further analysis indicated that the two mass fractions were modulated by the neutralizing level of atmospheric aerosols, and the negative correlation could be found in acidic atmospheric particles. Strong negative correlation was usually observed on clear days, hazy days, foggy days, and respirable particulate air pollution days, whereas poor negative correlation was often observed during cloud, rain, snow, dust storm, and suspended dust events. The results can help to better understand the formation mechanisms of atmospheric sulfate and nitrate during air pollution episodes and to better explain field results of atmospheric chemistry concerning sulfate and nitrate.

  15. Algae as an electron donor promoting sulfate reduction for the bioremediation of acid rock drainage

    Energy Technology Data Exchange (ETDEWEB)

    Ayala-Parra, Pedro; Sierra-Alvarez, Reyes; Field, Jim A., E-mail: jimfield@email.arizona.edu

    2016-11-05

    Highlights: • Algal biomass can serve as an electron donor to drive reduction of sulfate to sulfide. • Biogenic sulfide precipitates Cu{sup 2+} as stable sulfide mineral. • Cu{sup +2} removal in sulfidogenic bioreactors amended with algal biomass exceeded 99.5%. • Acidity in synthetic acid rock drainage was consumed by sulfate reduction. - Abstract: This study assessed bioremediation of acid rock drainage in simulated permeable reactive barriers (PRB) using algae, Chlorella sorokiniana, as the sole electron donor for sulfate-reducing bacteria. Lipid extracted algae (LEA), the residues of biodiesel production, were compared with whole cell algae (WCA) as an electron donor to promote sulfate-reducing activity. Inoculated columns containing anaerobic granular sludge were fed a synthetic medium containing H{sub 2}SO{sub 4} and Cu{sup 2+}. Sulfate, sulfide, Cu{sup 2+} and pH were monitored throughout the experiment of 123 d. Cu recovered in the column packing at the end of the experiment was evaluated using sequential extraction. Both WCA and LEA promoted 80% of sulfate removal (12.7 mg SO{sub 4}{sup 2−} d{sup −1}) enabling near complete Cu removal (>99.5%) and alkalinity generation raising the effluent pH to 6.5. No noteworthy sulfate reduction, alkalinity formation and Cu{sup 2+} removal were observed in the endogenous control. In algae amended-columns, Cu{sup 2+} was precipitated with biogenic H{sub 2}S produced by sulfate reduction. Formation of CuS was evidenced by sequential extraction and X-ray diffraction. LEA and WCA provided similar levels of electron donor based on the COD balance. The results demonstrate an innovative passive remediation system using residual algae biomass from the biodiesel industry.

  16. Algae as an electron donor promoting sulfate reduction for the bioremediation of acid rock drainage

    International Nuclear Information System (INIS)

    Ayala-Parra, Pedro; Sierra-Alvarez, Reyes; Field, Jim A.

    2016-01-01

    Highlights: • Algal biomass can serve as an electron donor to drive reduction of sulfate to sulfide. • Biogenic sulfide precipitates Cu 2+ as stable sulfide mineral. • Cu +2 removal in sulfidogenic bioreactors amended with algal biomass exceeded 99.5%. • Acidity in synthetic acid rock drainage was consumed by sulfate reduction. - Abstract: This study assessed bioremediation of acid rock drainage in simulated permeable reactive barriers (PRB) using algae, Chlorella sorokiniana, as the sole electron donor for sulfate-reducing bacteria. Lipid extracted algae (LEA), the residues of biodiesel production, were compared with whole cell algae (WCA) as an electron donor to promote sulfate-reducing activity. Inoculated columns containing anaerobic granular sludge were fed a synthetic medium containing H 2 SO 4 and Cu 2+ . Sulfate, sulfide, Cu 2+ and pH were monitored throughout the experiment of 123 d. Cu recovered in the column packing at the end of the experiment was evaluated using sequential extraction. Both WCA and LEA promoted 80% of sulfate removal (12.7 mg SO 4 2− d −1 ) enabling near complete Cu removal (>99.5%) and alkalinity generation raising the effluent pH to 6.5. No noteworthy sulfate reduction, alkalinity formation and Cu 2+ removal were observed in the endogenous control. In algae amended-columns, Cu 2+ was precipitated with biogenic H 2 S produced by sulfate reduction. Formation of CuS was evidenced by sequential extraction and X-ray diffraction. LEA and WCA provided similar levels of electron donor based on the COD balance. The results demonstrate an innovative passive remediation system using residual algae biomass from the biodiesel industry.

  17. Fucoidans — sulfated polysaccharides of brown algae

    Science.gov (United States)

    Usov, Anatolii I.; Bilan, M. I.

    2009-08-01

    The methods of isolation of fucoidans and determination of their chemical structures are reviewed. The fucoidans represent sulfated polysaccharides of brown algae, the composition of which varies from simple fucan sulfates to complex heteropolysaccharides. The currently known structures of such biopolymers are presented. A variety of the biological activities of fucoidans is briefly summarised.

  18. Rat pro-opiomelanocortin contains sulfate

    Energy Technology Data Exchange (ETDEWEB)

    Hoshina, H.; Hortin, G.; Boime, I.

    1982-07-02

    Intermediate lobes isolated from rat pituitary glands incorporated (/sup 35/S)sulfate into pro-opiomelanocortin and other adrenocorticotropic hormone-containing peptides. Incubation of intermediate lobes in medium containing the arginine analog canavanine inhibited the cleavage of pro-opiomelanocortin into smaller products. Pro-opiomelanocortin that accumulated in the presence of canavanine was also sulfated.

  19. The anaerobic treatment of sulfate containing wastewater

    NARCIS (Netherlands)

    Visser, A.

    1995-01-01


    In the anaerobic treatment of sulfate containing wastewater sulfate reducing bacteria (SRB) will compete with methanogenic- (MB) and acetogenic bacteria (AB) for the available substrates such as hydrogen, acetate, propionate and butyrate. The outcome of this competition will

  20. Palladium(II)-catalyzed ortho-C-H arylation/alkylation of N-benzoyl α-amino ester derivatives.

    Science.gov (United States)

    Misal Castro, Luis C; Chatani, Naoto

    2014-04-14

    The palladium-catalyzed arylation/alkylation of ortho-C-H bonds in N-benzoyl α-amino ester derivatives is described. In such a system both the NH-amido and the CO2R groups in the α-amino ester moieties play a role in successful C-H activation/C-C bond formation using iodoaryl coupling partners. A wide variety of functional groups and electron-rich/deficient iodoarenes are tolerated. The yields obtained range from 20 to 95%. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Stereoselective ZrCl4-Catalyzed Mannich-type Reaction of β-Keto Esters with Chiral Trifluoromethyl Aldimines.

    Science.gov (United States)

    Parise, Luca; Pellacani, Lucio; Sciubba, Fabio; Trulli, Laura; Fioravanti, Stefania

    2015-08-21

    A method for the synthesis of fluorinated β'-amino β-dicarbonyl compounds using a Zr-catalyzed Mannich-type reaction has been developed, starting from N-protected trifluoromethyl aldimines and cyclic or acyclic β-keto esters bearing different ester residues. The in situ generated metallic complex reacted with optically pure trifluoromethyl aldimine derived from (R)-α-methylbenzylamine, giving a highly diastereoselective asymmetric Mannich-type addition with formation of a chiral quaternary center. The absolute configuration at the new chiral centers was assigned through two-dimensional nuclear Overhauser effect spectroscopic analysis coupled with computational studies.

  2. Environmentally friendly properties of vegetable oil methyl esters

    Directory of Open Access Journals (Sweden)

    Gateau Paul

    2005-07-01

    Full Text Available Measurements were carried out on Vegetable Oil Methyl Esters (VOME or FAME answering the most recent specifications. The products tested are RME (Rapeseed oil Methyl Ester, ERME (Erucic Rapeseed oil Methyl Esters, SME (Sunflower oil Methyl Esters, and HOSME (High Oleic Sunflower oil Methyl Esters. They contain more than 99.5% of fatty acid mono esters. The compositions are given. VOME are not volatile and they are not easily flammable. They are not soluble in water and they are biodegradable. According to the methods implemented for the determination of the German classification of substances hazardous to waters WGK, they are not toxic on mammals and unlike diesel fuel they are not toxic on fish, daphnia, algae and bacteria. The RME is not either toxic for shrimps. According to tests on rabbits, RME and SME are not irritating for the skin and the eyes. VOME display particularly attractive environmental properties.

  3. The ammonium sulfate inhibition of human angiogenin.

    Science.gov (United States)

    Chatzileontiadou, Demetra S M; Tsirkone, Vicky G; Dossi, Kyriaki; Kassouni, Aikaterini G; Liggri, Panagiota G V; Kantsadi, Anastassia L; Stravodimos, George A; Balatsos, Nikolaos A A; Skamnaki, Vassiliki T; Leonidas, Demetres D

    2016-09-01

    In this study, we investigate the inhibition of human angiogenin by ammonium sulfate. The inhibitory potency of ammonium sulfate for human angiogenin (IC50 = 123.5 ± 14.9 mm) is comparable to that previously reported for RNase A (119.0 ± 6.5 mm) and RNase 2 (95.7 ± 9.3 mm). However, analysis of two X-ray crystal structures of human angiogenin in complex with sulfate anions (in acidic and basic pH environments, respectively) indicates an entirely distinct mechanism of inhibition. While ammonium sulfate inhibits the ribonucleolytic activity of RNase A and RNase 2 by binding to the active site of these enzymes, sulfate anions bind only to peripheral substrate anion-binding subsites of human angiogenin, and not to the active site. © 2016 Federation of European Biochemical Societies.

  4. Desulfotignum phosphitoxidans sp. nov., a new marine sulfate reducer that oxidizes phosphite to phosphate.

    Science.gov (United States)

    Schink, Bernhard; Thiemann, Volker; Laue, Heike; Friedrich, Michael W

    2002-05-01

    A new sulfate-reducing bacterium was isolated from marine sediment with phosphite as sole electron donor and CO(2) as the only carbon source. Strain FiPS-3 grew slowly, with doubling times of 3-4 days, and oxidized phosphite, hydrogen, formate, acetate, fumarate, pyruvate, glycine, glutamate, and other substrates nearly completely, with concomitant reduction of sulfate to sulfide. Acetate was formed as a side product to a small extent. Glucose, arabinose, and proline were partly oxidized and partly fermented to acetate plus propionate. Growth with phosphite, hydrogen, or formate was autotrophic. Also, in the presence of sulfate, CO dehydrogenase was present, and added acetate did not increase growth rates or growth yields. In the absence of sulfate, phosphite oxidation was coupled to homoacetogenic acetate formation, with growth yields similar to those in the presence of sulfate. Cells were small rods, 0.6 - 0.8 x 2-4 microm in size, and gram-negative, with a G+C content of 53.9 mol%. They contained desulforubidin, but no desulfoviridin. Based on sequence analysis of the 16S rRNA gene and the sulfite reductase genes dsrAB, strain FiPS-3 was found to be closely related to Desulfotignum balticum. However, physiological properties differed in many points from those of D. balticum. These findings justify the establishment of a new species, Desulfotignum phosphitoxidans.

  5. Removal of high concentration of sulfate from pigment industry effluent by chemical precipitation using barium chloride: RSM and ANN modeling approach.

    Science.gov (United States)

    Navamani Kartic, D; Aditya Narayana, B Ch; Arivazhagan, M

    2018-01-15

    Sulfate ions pose a major threat and challenge in the treatment of industrial effluents. The sample of wastewater obtained from a pigment industry contained large quantities of sulfate in the form of sodium sulfate which resulted in high TDS. As the removal of sulfate from pigment industry effluent was not reported previously, this work was focused on removing the sulfate ions from the effluent by chemical precipitation using barium chloride. The efficiency of sulfate removal was nearly 100% at an excess dosage of barium chloride, which precipitates the dissolved sulfate ions in the form of barium sulfate. Optimization of the parameters was done using Response Surface Methodology (RSM). This work is the first attempt for modeling the removal of sulfate from pigment industry effluent using RSM and Artificial Neural Network (ANN). Prediction by both the models was evaluated and both of them exhibited good performance (R 2 value > 0.99). It was observed that the prediction by RSM (R 2 value 0.9986) was closer to the experimental results than ANN prediction (R 2 value 0.9955). The influence on the pH and conductivity of the solution by dosage of precipitant was also studied. The formation of barium sulfate was confirmed by characterization of the precipitate. Therefore, the sulfate removed from the effluent was converted into a commercially valuable precipitate. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Carboxylesterase-dependent cytotoxicity of dibasic esters (DBE) in rat nasal explants.

    Science.gov (United States)

    Trela, B A; Bogdanffy, M S

    1991-02-01

    Dibasic esters (DBE) are a solvent mixture of dimethyl adipate (DMA), dimethyl glutarate (DMG), and dimethyl succinate (DMS) used in the paint and coating industry. Subchronic inhalation toxicity studies have demonstrated that DBE induce a mild degeneration of the olfactory, but not the respiratory, epithelium of the rat nasal cavity. Carboxylesterase-mediated hydrolysis of the individual dibasic esters is more efficient in olfactory than in respiratory mucosal homogenates. In the present study, an in vitro system of cultured rat nasal explants was utilized to determine if DBE toxicity is dependent on a metabolic activation by nonspecific carboxylesterase. Explants from both the olfactory and the respiratory regions of the female rat nasal cavity were incubated for 2 hr in Williams' medium E containing 10-100 mM DMA, DMG, or DMS. DBE caused a dose-related increase in nasal explant acid phosphatase release, a biochemical index of cytotoxicity. HPLC analysis demonstrated parallel increases in the carboxylesterase-mediated formation of monomethyl ester metabolites. Diacid metabolite production in the nasal explant system was not entirely concentration-dependent. Metabolite concentrations and acid phosphatase release were generally greater in olfactory than respiratory tissues. DBE-induced cytotoxicity and acid metabolite production were markedly attenuated in nasal tissue excised from rats which were pretreated with bis(p-nitrophenyl)phosphate, a carboxylesterase inhibitor. This study presents a viable in vitro method for assessing organic ester cytotoxicity in the rat nasal cavity. It was shown that DBE are weak nasal toxicants under the conditions of this system. It was further demonstrated that DBE toxicity is dependent on a carboxylesterase-mediated activation. A similar mechanism was proposed for the nasal toxicity induced by other organic esters following inhalation exposure.

  7. Metabolic Flexibility of Sulfate Reducing Bacteria

    Directory of Open Access Journals (Sweden)

    Caroline M. Plugge

    2011-05-01

    Full Text Available Dissimilatory sulfate-reducing prokaryotes (SRB are a very diverse group of anaerobic bacteria that are omnipresent in nature and play an imperative role in the global cycling of carbon and sulfur. In anoxic marine sediments sulfate reduction accounts for up to 50% of the entire organic mineralization in coastal and shelf ecosystems where sulfate diffuses several meters deep into the sediment. As a consequence, SRB would be expected in the sulfate-containing upper sediment layers, whereas methanogenic Archaea would be expected to succeed in the deeper sulfate-depleted layers of the sediment. Where sediments are high in organic matter, sulfate is depleted at shallow sediment depths, and biogenic methane production will occur. In the absence of sulfate, many SRB ferment organic acids and alcohols, producing hydrogen, acetate, and carbon dioxide, and may even rely on hydrogen- and acetate-scavenging methanogens to convert organic compounds to methane. SRB can establish two different life styles, and these can be termed as sulfidogenic and acetogenic, hydrogenogenic metabolism. The advantage of having different metabolic capabilities is that it raises the chance of survival in environments when electron acceptors become depleted. In marine sediments, SRB and methanogens do not compete but rather complement each other in the degradation of organic matter.Also in freshwater ecosystems with sulfate concentrations of only 10-200 μM, sulfate is consumed efficiently within the top several cm of the sediments. Here, many of the δ-Proteobacteria present have the genetic machinery to perform dissimilatory sulfate reduction, yet they have an acetogenic, hydrogenogenic way of life.In this review we evaluate the physiology and metabolic mode of SRB in relation with their environment.

  8. Mutagenic activity of phthalate esters in bacterial liquid suspension assays.

    OpenAIRE

    Seed, J L

    1982-01-01

    The mutagenic activities of several phthalate esters have been evaluated in an 8-azaguanine resistance assay in Salmonella typhimurium. Three phthalate esters were found to be mutagenic: dimethyl phthalate, diethyl phthalate and di-n-butyl phthalate. A number of other phthalate esters were not found to be mutagenic, including di(2-ethylhexyl) phthalate, di-n-octyl phthalate, diallyl phthalate, diisobutyl phthalate and diisodecyl phthalate. A metabolite of di(2-ethylhexyl) phthalate, 2-ethylhe...

  9. Isolation and identification of an ester from a crude oil

    Science.gov (United States)

    Phillips, H.F.; Breger, I.A.

    1958-01-01

    A dioctylphthalate has been isolated from a crude oil by means of adsorption column chromatography. The ester was identified by means of elemental analysis, refractive index, and its infra-red absorption spectrum. Saponification of the isolate and examination of the resultant alcohol by means of infrared absorption spectra led to the conclusion that the ester is a branched chain dioctylphthalate. This is the first reported occurrence of an ester in crude petroleum. ?? 1958.

  10. Biotransformation--XXXIV. Metabolism of testosterone esters in fungi cultures.

    Science.gov (United States)

    Brzezowska, E; Dmochowska-Gładysz, J; Kołek, T; Nobilec, E

    1993-08-01

    Seven esters of testosterone: acetate, propionate, enanthate, caprate, undecanoate, isobutyrate and isocaproate (some of them are used as drugs) were transformed by microorganisms: Absidia coerulea, Acremonium roseum, Aphanocladium album and Rhodotorula mucilaginosa to obtain some information about their metabolism. It was observed that the presence and structure of the acyl group mainly influenced the degree of transformation. The first step of the reaction was probably hydrolysis of ester, followed by testosterone transformation. Only the branched chain esters were transformed by R. mucilaginosa without hydrolysis of the ester bond.

  11. Emission and Mechanical Evaluations of Vinyl-Ester Resin Systems

    National Research Council Canada - National Science Library

    Sands, James

    2003-01-01

    Vinyl-ester resins (VE) are frequently used in liquid molding of composite materials for several applications including naval and army structures, commercial boat manufacturing, and building construction...

  12. A novel thermooxidatively stable poly(ester-imide-benzoxazole)

    Energy Technology Data Exchange (ETDEWEB)

    Sundar, R.A.; Mathias, L.J. [Univ. of Sothern Mississippi, Hattiesburg, MS (United States)

    1993-12-31

    A poly(ester-amide-imide) was synthesized by the low temperature solution polycondensation of 4-amino-5-hydroxy-N,4{prime}-hydroxyphenyl phthalimide with isophthaloyl chloride. Subsequent thermal cyclodehydration of the poly(ester-amide-imide) at 320{degrees}C in vacuum afforded the poly(ester-imide-benzoxazole). This polymer was only soluble in sulfuric acid. FTIR and NMR spectra confirmed structure. The poly(ester-imide-benzoxazole) had no detectable thermal transitions up to 500{degrees}C in nitrogen, and was reasonably stable in air and nitrogen, with weight retentions of 95% at 500{degrees}C.

  13. Investigation of bifunctional ester additives for methanol-gasoline system

    International Nuclear Information System (INIS)

    Zhang, J.; Yang, C.; Tang, Y.; Du, Q.; Song, N.; Zhang, Z.

    2014-01-01

    To explore new and multifunctional additives for methanol-gasoline, tartaric ester were synthesized and screened as phase stabilizer and saturation vapor pressure depressor for methanol-gasoline. The effect of the esters structure on the efficiency was discussed. The results show that the stabilities of the blends depend on the length of the glycolic esters alkoxy group. In addition, the tartaric esters also can depress the saturation vapor pressure of methanol-gasoline effectively in M15. Effect of the structure on the efficiency was also discussed. (author)

  14. Tandem transformation of glycerol to esters.

    Science.gov (United States)

    Sotenko, Maria V; Rebroš, Martin; Sans, Victor S; Loponov, Konstantin N; Davidson, Matthew G; Stephens, Gill; Lapkin, Alexei A

    2012-12-31

    Tandem transformation of glycerol via microbial fermentation and enzymatic esterification is presented. The reaction can be performed with purified waste glycerol from biodiesel production in a continuous mode, combining continuous fermentation with membrane-supported enzymatic esterification. Continuous anaerobic fermentation was optimized resulting in the productivity of 2.4 g L⁻¹ h⁻¹ of 1,3-propanediol. Biphasic esterification of 1,3-propanediol was optimized to achieve ester yield of up to 75%. A hollow fibre membrane contactor with immobilized Rhizomucor miehei lipase was demonstrated for the continuous tandem fermentation-esterification process. Copyright © 2012 Elsevier B.V. All rights reserved.

  15. Palladium-catalysed arylation of acetoacetate esters to yield 2-arylacetic acid esters

    CSIR Research Space (South Africa)

    Zeevaart, JG

    2004-05-24

    Full Text Available The coupling reaction between ethyl acetoacetate and a number of aryl halides in the presence of palladium acetate, a bulky and electron rich phosphine and K3PO4 is described. The arylated acetoacetate ester is de-acylated under the reaction...

  16. Surface activity evaluation of an arabinose ester as water/oil demulsifier at severe conditions of temperature, salinity and pH; Avaliacao da atividade superficial de um ester de arabinose, como desemulsificante agua/oleo, em condicoes severas de temperatura, salinidade e pH

    Energy Technology Data Exchange (ETDEWEB)

    Borges, Mauricio Rodrigues; Garcia, Rosangela Balaban; Santos, Jaciara Alves dos; Vieira, Mariane; Silva, Luciana Carvalho; Campos, Viviane de Oliveira; Silva, Rayane Araujo da; Santos, Telma Pitanga dos [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

    2008-07-01

    This work had for objective to compare the superficial properties of an arabinose ester, no-ionic, nontoxic, biodegradable, with two commercial products: the first one based on sodium dodecyl sulfate and the second one based on poly-oxy alkylene phenol formaldehyde. The arabinose ester was synthesized on the Petroleum Research Laboratory - UFRN, through enzymatic catalysis by protease from Bacillus subtilis, using arabinose and vegetable oil, in organic medium. In previous work [1], this sugar ester was evaluated as a possible water/oil demulsifier and the results were compared with the results of the commercial product based on poly-oxy alkylene phenol formaldehyde, showing that, for certain reaction conditions, the sugar ester presented better acting (71%) that the commercial product (33%) as demulsifier. In this work, the stability of this arabinose ester was evaluated in severe conditions of temperature, salinity and pH, through superficial tests in a tensiometer, using Wilhelmy plate method and the results were compared with the results obtained for two commercial products above mentioned. (author)

  17. The influence of complex cation on the change of O- defect in ammonium sulfate

    International Nuclear Information System (INIS)

    Orazbaev, A. Kh.

    1999-01-01

    By the methods of quantum chemistry a possibilities of oxygen ion formation during interaction of atomic oxygen as well as OH 0 OH - secondary defects with ammonium sulfate cation sublattice are considered. Calculations have been conducted by MNDO method. It is established, that ammonium ion does not exert an effect on atomic oxygen migration. The ion capture is more possible within cation sublattice. Interactions of cation complexes with OH - and OH 0 show, that neither atomic oxygen nor it ion formation does not have place in these cation complexes. It is noticed, that NH 3 0 defect could arise not only due to dissociative capture of electron by cation, but and in the post-radiation stage during interaction with oxygen ion. Obtained results allow to suppose a possible reasons of essential weakness of recombination luminescence in ammonium sulfate in comparison with alkaline metal sulfates

  18. Novel cellulose ester substrates for high performance flat-sheet thin-film composite (TFC) forward osmosis (FO) membranes

    KAUST Repository

    Ong, Rui Chin

    2015-01-01

    A novel hydrophilic cellulose ester with a high intrinsic water permeability and a water partition coefficient was discovered to construct membrane supports for flat-sheet thin film composite (TFC) forward osmosis (FO) membranes for water reuse and seawater desalination with high performance. The performance of TFC-FO membranes prepared from the hydrophilic cellulose ester containing a high degree of OH and a moderate degree of Pr substitutions clearly surpasses those prepared from cellulose esters and other polymers with moderate hydrophilicity. Post-treatments of TFC-FO membranes using sodium dodecyl sulfate (SDS) and glycerol followed by heat treatment further enhance the water flux without compromising the selectivity. Positron annihilation lifetime analyses have confirmed that the SDS/glycerol post-treatment increases the free volume size and fractional free volume of the polyamide selective layer. The newly developed post-treated TFC-FO membranes exhibit a remarkably high water flux up to 90 LMH when the selective layer is oriented towards the draw solution (i.e., PRO mode) using 1. M NaCl as the draw solution and DI water as the feed. For seawater desalination, the membranes display a high water flux up to 35 LMH using a 2. M NaCl draw solution. These water fluxes exceeded the water fluxes achieved by other types of FO membranes reported in literatures. © 2014 Elsevier B.V.

  19. Morphological studies of DHSA/ DHSA-Octyl ester/ RBD palm kernel olein/ medium chain triglycerides system

    International Nuclear Information System (INIS)

    Anuar Kassim; Nadarajan, Rathidevi; Mohd Zaizi Desa; Atan Mohd Sharif; Dzulkefly Kuang; Mohd Jelas Haron

    2007-01-01

    Dihydroxystearic acid (DHSA) and octyl dihydroxystearate (DHSA-octyl ester) have been previously prepared from palm oleic acid and preliminary results showed that these compounds are suitable in personal care and cosmetics products. The objective of this research is to study the phase behavior in ternary system of DHSA/DHSA-octyl ester/RBD Palm Kernel Olein (RBDPKOo) and MCT at 85 degree Celsius. From the ternary phase diagram, results showed that all ratios of were completely in two-phase region with various concentrations of RBDPKOo and MCT. The phase changes were observed through polarizing light while the formation of texture was confirmed using polarizing microscope combination with heating. Needles and spherulite textures were found in this system. (author)

  20. [Synthesis and regulation of flavor compounds derived from brewing yeast: Esters].

    Science.gov (United States)

    Loviso, Claudia L; Libkind, Diego

    2018-04-04

    During brewing process yeast produce more than 500 chemical compounds that can negatively and positively impact beer at the organoleptic level. In recent years, and particularly thanks to the advancement of molecular biology and genomics, there has been considerable progress in our understanding about the molecular and cellular basis of the synthesis and regulation of many of these flavor compounds. This article focuses on esters, responsible for the floral and fruity beer flavor. Its formation depends on various enzymes and factors such as the concentration of wort nutrients, the amount of dissolved oxygen and carbon dioxide, fermentation temperature and mainly the genetics of the yeast used. We provide information about how the esters originate and how is the impact of different fermentative parameters on the final concentrations of these compounds and the quality of the end product. Copyright © 2018 The Authors. Publicado por Elsevier España, S.L.U. All rights reserved.

  1. Structure of ruthenium(II) complexes with coproporphyrin I tetraethyl ester

    Science.gov (United States)

    Zverev, S. A.; Andreev, S. V.; Zamilatskov, I. A.; Kurochkina, N. M.; Tyurin, V. S.; Senchikhin, I. N.; Ponomarev, G. V.; Erzina, D. R.; Chernyshev, V. V.

    2017-08-01

    The reaction between coproporphyrin I tetraethyl ester and ruthenium(II) dodecacarbonyl in toluene is investigated. The formation of two different products, complexes 2 and 3 of ruthenium(II) with coproporphyrin I tetraethyl ester, studied by means of mass spectrometry, electronic absorption spectroscopy, NMR, X-ray diffraction, and thermogravimetric analysis, is revealed. Structures are proposed for the products, of which ( 2) is a monocarbonyl complex of ruthenium(II) porphyrin that exists as a coordination polymer formed owing to intermolecular axial bonding between the oxygen atoms of carboethoxyl groups and ruthenium(II). The structure proposed for second product ( 3) is in the form of the corresponding monomer of a monocarbonyl complex of ruthenium(II) porphyrin. It is established that polymeric complex 2 transforms into monomeric complex 3 when it is heating in pyridine.

  2. Thermochemical sulfate reduction in deep petroleum reservoirs: a molecular approach; Thermoreduction des sulfates dans les reservoirs petroliers: approche moleculaire

    Energy Technology Data Exchange (ETDEWEB)

    Hanin, S.

    2002-11-01

    The thermochemical sulfate reduction (TSR) is a set of chemical reactions leading to hydrocarbon oxidation and production of carbon dioxide and sour gas (H{sub 2}S) which is observed in deep petroleum reservoirs enriched in anhydrites (calcium sulfate). Molecular and isotopic studies have been conducted on several crude oil samples to determine which types of compounds could have been produced during TSR. Actually, we have shown that the main molecules formed by TSR were organo-sulfur compounds. Indeed, sulfur isotopic measurements. of alkyl-di-benzothiophenes, di-aryl-disulfides and thia-diamondoids (identified by NMR or synthesis of standards) shows that they are formed during TSR as their value approach that of the sulfur of the anhydrite. Moreover, thia-diamondoids are apparently exclusively formed during this phenomenon and can thus be considered as true molecular markers of TSR. In a second part, we have investigated with laboratory experiments the formation mechanism of the molecules produced during TSR. A first model has shown that sulfur incorporation into the organic matter occurred with mineral sulfur species of low oxidation degree. The use of {sup 34}S allowed to show that the sulfates reduction occurred during these simulations. At least, some experiments on polycyclic hydrocarbons, sulfurized or not, allowed to establish that thia-diamondoids could be formed by acid-catalysed rearrangements at high temperatures in a similar way as the diamondoids. (author)

  3. Synthesis of seaweed based carbon acid catalyst by thermal decomposition of ammonium sulfate for biodiesel production

    Science.gov (United States)

    Ee, Tang Zo; Lim, Steven; Ling, Pang Yean; Huei, Wong Kam; Chyuan, Ong Hwai

    2017-04-01

    Experiment was carried out to study the feasibility of biomass derived solid acid catalyst for the production of biodiesel using Palm Fatty Acid Distillate (PFAD). Malaysia indigenous seaweed was selected as the biomass to be carbonized as the catalyst support. Sulfonation of seaweed based carbon material was carried out by thermal decomposition of ammonium sulfate, (NH4)2SO4. The effects of carbonization temperature at 200 to 600°C on the catalyst physical and chemical properties were studied. The effect of reaction parameters on the fatty acid methyl ester (FAME) yield was studied by varying the concentration of ammonium sulfate (5.0 to 40.0 w/v%) and thermal decomposition time (15 to 90 min). Characterizations of catalyst were carried out to study the catalyst surface morphology with Scanning Electron Microscope (SEM), acid density with back titration and functional group attached with FT-IR. Results showed that when the catalyst sulfonated with 10.0 w/v% ammonium sulfate solution and heated to 235°C for 30 min, the highest FAME yield achieved was 23.7% at the reaction condition of 5.0 wt.% catalyst loading, esterification time of 4 h, methanol to PFAD molar ratio of 20:1 at 100°C reaction temperature.

  4. [Aluminum forms in acid sulfate soils].

    Science.gov (United States)

    Wang, J; Luo, S; Feng, Y

    2000-10-01

    With the method of sequential extraction, the extractable noncrystalline aluminum in Acid Sulfate Soils was fractionized into exchangeable Al (ExAl), absorbed inorganic hydroxy-Al(HyAl), organic complexed Al(OrAl), Fe oxide bound Al (DCBAl), interlayered Al(InAl) and noncrystalline aluminosilicate(NcAl) with average of 1.79, 2.51, 4.17, 4.14, 4.31 and 8.66 g Al2O3.kg-1, respectively. In actual Acid Sulfate Soils, the amount of different forms Al followed the order of NcAl > OrAl > InAl > DCBAl > ExAl > HyAl, but in potential acid sulfate soils, NcAl > InAl > DCBAl > HyAl > OrAl > ExAl. The average of the total extractable noncrystalline Al was 35.57 g Al2O3.kg-1, which covered 25.04% of the total amount of Al in Acid Sulfate Soils. The characteristic of extractable noncrystalline Al in Acid Sulfate Soils was the high proportion of active aluminum, such as ExAl, HyAl and OrAl. All forms of Al were closely related to the corresponding properties and ecological characteristics of Acid Sulfate Soils. The strong acid environment of actual Acid Sulfate Soils induced over-released Al, which transformed to active Al and resulted in Al toxicity.

  5. Benzene oxidation coupled to sulfate reduction

    Science.gov (United States)

    Lovley, D.R.; Coates, J.D.; Woodward, J.C.; Phillips, E.J.P.

    1995-01-01

    Highly reduced sediments from San Diego Bay, Calif., that were incubated under strictly anaerobic conditions metabolized benzene within 55 days when they were exposed initially to I ??M benzene. The rate of benzene metabolism increased as benzene was added back to the benzene-adapted sediments. When a [14C]benzene tracer was included with the benzene added to benzene-adapted sediments, 92% of the added radioactivity was recovered as 14CO2. Molybdate, an inhibitor of sulfate reduction, inhibited benzene uptake and production of 14CO2 from [14C]benzene. Benzene metabolism stopped when the sediments became sulfate depleted, and benzene uptake resumed when sulfate was added again. The stoichiometry of benzene uptake and sulfate reduction was consistent with the hypothesis that sulfate was the principal electron acceptor for benzene oxidation. Isotope trapping experiments performed with [14C]benzene revealed that there was no production of such potential extracellular intermediates of benzene oxidation as phenol, benzoate, p-hydroxybenzoate, cyclohexane, catechol, and acetate. The results demonstrate that benzene can be oxidized in the absence of O2, with sulfate serving as the electron acceptor, and suggest that some sulfate reducers are capable of completely oxidizing benzene to carbon dioxide without the production of extracellular intermediates. Although anaerobic benzene oxidation coupled to chelated Fe(III) has been documented previously, the study reported here provides the first example of a natural sediment compound that can serve as an electron acceptor for anaerobic benzene oxidation.

  6. Neutral Lipid Biosynthesis in Engineered Escherichia coli: Jojoba Oil-Like Wax Esters and Fatty Acid Butyl Esters

    OpenAIRE

    Kalscheuer, Rainer; Stöveken, Tim; Luftmann, Heinrich; Malkus, Ursula; Reichelt, Rudolf; Steinbüchel, Alexander

    2006-01-01

    Wax esters are esters of long-chain fatty acids and long-chain fatty alcohols which are of considerable commercial importance and are produced on a scale of 3 million tons per year. The oil from the jojoba plant (Simmondsia chinensis) is the main biological source of wax esters. Although it has a multitude of potential applications, the use of jojoba oil is restricted, due to its high price. In this study, we describe the establishment of heterologous wax ester biosynthesis in a recombinant E...

  7. Multi-model comparison of the volcanic sulfate deposition from the 1815 eruption of Mt. Tambora

    Directory of Open Access Journals (Sweden)

    L. Marshall

    2018-02-01

    Full Text Available The eruption of Mt. Tambora in 1815 was the largest volcanic eruption of the past 500 years. The eruption had significant climatic impacts, leading to the 1816 year without a summer, and remains a valuable event from which to understand the climatic effects of large stratospheric volcanic sulfur dioxide injections. The eruption also resulted in one of the strongest and most easily identifiable volcanic sulfate signals in polar ice cores, which are widely used to reconstruct the timing and atmospheric sulfate loading of past eruptions. As part of the Model Intercomparison Project on the climatic response to Volcanic forcing (VolMIP, five state-of-the-art global aerosol models simulated this eruption. We analyse both simulated background (no Tambora and volcanic (with Tambora sulfate deposition to polar regions and compare to ice core records. The models simulate overall similar patterns of background sulfate deposition, although there are differences in regional details and magnitude. However, the volcanic sulfate deposition varies considerably between the models with differences in timing, spatial pattern and magnitude. Mean simulated deposited sulfate on Antarctica ranges from 19 to 264 kg km−2 and on Greenland from 31 to 194 kg km−2, as compared to the mean ice-core-derived estimates of roughly 50 kg km−2 for both Greenland and Antarctica. The ratio of the hemispheric atmospheric sulfate aerosol burden after the eruption to the average ice sheet deposited sulfate varies between models by up to a factor of 15. Sources of this inter-model variability include differences in both the formation and the transport of sulfate aerosol. Our results suggest that deriving relationships between sulfate deposited on ice sheets and atmospheric sulfate burdens from model simulations may be associated with greater uncertainties than previously thought.

  8. Study of thermochemical sulfate reduction mechanism using compound specific sulfur isotope analysis

    Science.gov (United States)

    Meshoulam, Alexander; Ellis, Geoffrey S.; Ahmad, Ward Said; Deev, Andrei; Sessions, Alex L.; Tang, Yongchun; Adkins, Jess F.; Liu, Jinzhong; Gilhooly, William P.; Aizenshtat, Zeev; Amrani, Alon

    2016-01-01

    The sulfur isotopic fractionation associated with the formation of organic sulfur compounds (OSCs) during thermochemical sulfate reduction (TSR) was studied using gold-tube pyrolysis experiments to simulate TSR. The reactants used included n-hexadecane (n-C16) as a model organic compound with sulfate, sulfite, or elemental sulfur as the sulfur source. At the end of each experiment, the S-isotopic composition and concentration of remaining sulfate, H2S, benzothiophene, dibenzothiophene, and 2-phenylthiophene (PT) were measured. The observed S-isotopic fractionations between sulfate and BT, DBT, and H2S in experimental simulations of TSR correlate well with a multi-stage model of the overall TSR process. Large kinetic isotope fractionations occur during the first, uncatalyzed stage of TSR, 12.4‰ for H2S and as much as 22.2‰ for BT. The fractionations decrease as the H2S concentration increases and the reaction enters the second, catalyzed stage. Once all of the oxidizable hydrocarbons have been consumed, sulfate reduction ceases and equilibrium partitioning then dictates the fractionation between H2S and sulfate (∼17‰).

  9. Entamoeba mitosomes play an important role in encystation by association with cholesteryl sulfate synthesis.

    Science.gov (United States)

    Mi-ichi, Fumika; Miyamoto, Tomofumi; Takao, Shouko; Jeelani, Ghulam; Hashimoto, Tetsuo; Hara, Hiromitsu; Nozaki, Tomoyoshi; Yoshida, Hiroki

    2015-06-02

    Hydrogenosomes and mitosomes are mitochondrion-related organelles (MROs) that have highly reduced and divergent functions in anaerobic/microaerophilic eukaryotes. Entamoeba histolytica, a microaerophilic, parasitic amoebozoan species, which causes intestinal and extraintestinal amoebiasis in humans, possesses mitosomes, the existence and biological functions of which have been a longstanding enigma in the evolution of mitochondria. We previously demonstrated that sulfate activation, which is not generally compartmentalized to mitochondria, is a major function of E. histolytica mitosomes. However, because the final metabolites of sulfate activation remain unknown, the overall scheme of this metabolism and the role of mitosomes in Entamoeba have not been elucidated. In this study we purified and identified cholesteryl sulfate (CS) as a final metabolite of sulfate activation. We then identified the gene encoding the cholesteryl sulfotransferase responsible for synthesizing CS. Addition of CS to culture media increased the number of cysts, the dormant form that differentiates from proliferative trophozoites. Conversely, chlorate, a selective inhibitor of the first enzyme in the sulfate-activation pathway, inhibited cyst formation in a dose-dependent manner. These results indicate that CS plays an important role in differentiation, an essential process for the transmission of Entamoeba between hosts. Furthermore, we show that Mastigamoeba balamuthi, an anaerobic, free-living amoebozoan species, which is a close relative of E. histolytica, also has the sulfate-activation pathway in MROs but does not possess the capacity for CS production. Hence, we propose that a unique function of MROs in Entamoeba contributes to its adaptation to its parasitic life cycle.

  10. Synthesis and Proapoptotic Activity on Cervical Cancer Cell of Ester Eugenol 1-(3-Methoxy-4-hydroxy)phenyl-2-propylmethanoate

    Science.gov (United States)

    Farid Rahman, Moh.; Nazhif Haykal, Muhammad; Andriani Siagian, Novi; Maiselina Sriepindonnta, Priscilla; Tampubolon, Norman Alexander

    2018-01-01

    Proapoptotic activity of ester eugenol,1-(3-methoxy-4-hydroxy)phenyl-2-propylmethanoat, which synthesized from eugenol is reported. Eugenol as starting material in the synthesis of ester eugenol was obtained from fractional distillation of clove oil with the yield of 70.66%. Synthesis of ester eugenol was camed out by addition-esterification reaction through reaction between eugenol and formic acid with mol ratio of 1:27 and reaction time for11 h. GC-MS analysis showed ester eugenol was afforded purity of 92.42% and the yield in of 93.34%. UV spectra of ester eugenol was observed the formation of carbonyl group at λmax 290 nm and supported by FT-IR analysis at 1714.60 cm-1 (carbonyl group), 1193.65 cm-1 (C-O-C ester group) and the absence of vynil group in eugenol structure at region 914.20 and 995.20 cm-1. Mass spectra showed ion molecule at m/z 210 was accordance with molecular weight of ester eugenol. Afterward, HeLa cell culture media was prepared for cervical cancer antiproliferative test. The result which showed in histogram indicated that LC50 of ester eugenol was reached at concentration below 0.01% while eugenol was up to 0.01% that observed cervical cancer cell apoptotic activity. LC50 value of ester eugenol was obtained at concentration 48.73 ppm. This research reported that natural product modified its structure has potency to cure cervical cancer.

  11. Ammonium sulfate preparation from phosphogypsum waste

    OpenAIRE

    Kandil, Abdel-Hakim T.; Cheira, Mohamed F.; Gado, Hady S.; Soliman, Madiha H.; Akl, Hesham M.

    2017-01-01

    The Egyptian phosphogypsum waste is treated using sulfuric acid prior the ammonium sulfate production. The relevant factors that would affect the removal efficiencies of some impurities are studied. The optimum conditions of the treatment are 8 M sulfuric acid solution and 1/4 solid/liquid ratio for 30 min contact time at 80 °C. Moreover, the optimum conditions of the ammonium sulfate preparation are 10 g of the suspended impure or purified phosphogypsum in 40 ml of 3% ammonium sulfate soluti...

  12. Sulfated polysaccharides from marine sponges (Porifera): an ancestor cell-cell adhesion event based on the carbohydrate-carbohydrate interaction.

    Science.gov (United States)

    Vilanova, Eduardo; Coutinho, Cristiano C; Mourão, Paulo A S

    2009-08-01

    Marine sponges (Porifera) are ancient and simple eumetazoans. They constitute key organisms in the evolution from unicellular to multicellular animals. We now demonstrated that pure sulfated polysaccharides from marine sponges are responsible for the species-specific cell-cell interaction in these invertebrates. This conclusion was based on the following observations: (1) each species of marine sponge has a single population of sulfated polysaccharide, which differ among the species in their sugar composition and sulfate content; (2) sulfated polysaccharides from sponge interact with each other in a species-specific way, as indicated by an affinity chromatography assay, and this interaction requires calcium; (3) homologous, but not heterologous, sulfated polysaccharide inhibits aggregation of dissociated sponge cells; (4) we also observed a parallel between synthesis of the sulfated polysaccharide and formation of large aggregates of sponge cells, known as primmorphs. Once aggregation reached a plateau, the demand for the de novo synthesis of sulfated polysaccharides ceased. Heparin can mimic the homologous sulfated polysaccharide on the in vitro interaction and also as an inhibitor of aggregation of the dissociated sponge cells. However, this observation is not relevant for the biology of the sponge since heparin is not found in the invertebrate. In conclusion, marine sponges display an ancestor event of cell-cell adhesion, based on the calcium-dependent carbohydrate-carbohydrate interaction.

  13. Methanogenic archaea and sulfate reducing bacteria co-cultured on acetate: teamwork or coexistence?

    Directory of Open Access Journals (Sweden)

    Derya eOzuolmez

    2015-05-01

    Full Text Available Acetate is a major product of fermentation processes and an important substrate for sulfate reducing bacteria and methanogenic archaea. Most studies on acetate catabolism by sulfate reducers and methanogens have used pure cultures. Less is known about acetate conversion by mixed pure cultures and the interactions between both groups. We tested interspecies hydrogen transfer and coexistence between marine methanogens and sulfate reducers using mixed pure cultures of two types of microorganisms. First, Desulfovibrio vulgaris subsp. vulgaris (DSM 1744, a hydrogenotrophic sulfate reducer, was cocultured together with the obligate aceticlastic methanogen Methanosaeta concilii using acetate as carbon and energy source. Next, Methanococcus maripaludis S2, an obligate H2- and formate-utilizing methanogen, was used as a partner organism to M. concilii in the presence of acetate. Finally, we performed a coexistence experiment between M. concilii and an acetotrophic sulfate reducer Desulfobacter latus AcSR2. Our results showed that D. vulgaris was able to reduce sulfate and grow from hydrogen leaked by M. concilii. In the other coculture, M. maripaludis was sustained by hydrogen leaked by M. concilii as revealed by qPCR. The growth of the two aceticlastic microbes indicated co-existence rather than competition. Altogether, our results indicate that H2 leaking from M. concilii could be used by efficient H2-scavengers. This metabolic trait, revealed from coculture studies, brings new insight to the metabolic flexibility of methanogens and sulfate reducers residing in marine environments in response to changing environmental conditions and community compositions. Using dedicated physiological studies we were able to unravel the occurrence of less obvious interactions between marine methanogens and sulfate-reducing bacteria.

  14. Methanogenic archaea and sulfate reducing bacteria co-cultured on acetate: teamwork or coexistence?

    Science.gov (United States)

    Ozuolmez, Derya; Na, Hyunsoo; Lever, Mark A; Kjeldsen, Kasper U; Jørgensen, Bo B; Plugge, Caroline M

    2015-01-01

    Acetate is a major product of fermentation processes and an important substrate for sulfate reducing bacteria and methanogenic archaea. Most studies on acetate catabolism by sulfate reducers and methanogens have used pure cultures. Less is known about acetate conversion by mixed pure cultures and the interactions between both groups. We tested interspecies hydrogen transfer and coexistence between marine methanogens and sulfate reducers using mixed pure cultures of two types of microorganisms. First, Desulfovibrio vulgaris subsp. vulgaris (DSM 1744), a hydrogenotrophic sulfate reducer, was cocultured together with the obligate aceticlastic methanogen Methanosaeta concilii using acetate as carbon and energy source. Next, Methanococcus maripaludis S2, an obligate H2- and formate-utilizing methanogen, was used as a partner organism to M. concilii in the presence of acetate. Finally, we performed a coexistence experiment between M. concilii and an acetotrophic sulfate reducer Desulfobacter latus AcSR2. Our results showed that D. vulgaris was able to reduce sulfate and grow from hydrogen leaked by M. concilii. In the other coculture, M. maripaludis was sustained by hydrogen leaked by M. concilii as revealed by qPCR. The growth of the two aceticlastic microbes indicated co-existence rather than competition. Altogether, our results indicate that H2 leaking from M. concilii could be used by efficient H2-scavengers. This metabolic trait, revealed from coculture studies, brings new insight to the metabolic flexibility of methanogens and sulfate reducers residing in marine environments in response to changing environmental conditions and community compositions. Using dedicated physiological studies we were able to unravel the occurrence of less obvious interactions between marine methanogens and sulfate-reducing bacteria.

  15. New Model for Electron Flow for Sulfate Reduction in Desulfovibrio alaskensis G20

    Energy Technology Data Exchange (ETDEWEB)

    Keller, Kimberly L.; Rapp-Giles, Barbara J.; Semkiw, Elizabeth S.; Porat, Iris; Brown, Steven D.; Wall, Judy D.

    2014-02-01

    To understand the energy conversion activities of the anaerobic sulfate-reducing bacteria, it is necessary to identify the components involved in electron flow. The importance of the abundant type I tetraheme cytochrome c3 (TpIc3) as an electron carrier during sulfate respiration was questioned by the previous isolation of a null mutation in the gene encoding TpIc3, cycA, in Desulfovibrio alaskensis G20. Whereas respiratory growth of the CycA mutant with lactate and sulfate was little affected, growth with pyruvate and sulfate was significantly impaired. We have explored the phenotype of the CycA mutant through physiological tests and transcriptomic and proteomic analyses. Data reported here show that electrons from pyruvate oxidation do not reach adenylyl sulfate reductase, the enzyme catalyzing the first redox reaction during sulfate reduction, in the absence of either CycA or the type I cytochrome c3:menaquinone oxidoreductase transmembrane complex, QrcABCD. In contrast to the wild type, the CycA and QrcA mutants did not grow with H2 or formate and sulfate as the electron acceptor. Transcriptomic and proteomic analyses of the CycA mutant showed that transcripts and enzymes for the pathway from pyruvate to succinate were strongly decreased in the CycA mutant regardless of the growth mode. Neither the CycA nor the QrcA mutant grew on fumarate alone, consistent with the omics results and a redox regulation of gene expression. We conclude that TpIc3 and the Qrc complex are D. alaskensis components essential for the transfer of electrons released in the periplasm to reach the cytoplasmic adenylyl sulfate reductase and present a model that may explain the CycA phenotype through confurcation of electrons.

  16. New Model for Electron Flow for Sulfate Reduction in Desulfovibrio alaskensis G20

    Energy Technology Data Exchange (ETDEWEB)

    Rapp-Giles, Barbara J [University of Missouri, Columbia; Keller, Kimberly L [University of Missouri, Columbia; Porat, Iris [ORNL; Brown, Steven D [ORNL; Semkiw, Elizabeth M. [University of Missouri; Wall, Judy D. [University of Missouri

    2014-01-01

    To understand the energy conversion activities of the anaerobic sulfate-reducing bacteria, it is necessary to identify the components involved in electron flow. The importance of the abundant type I tetraheme cytochrome c3 (TpIc3) as an electron carrier during sulfate respiration was questioned by the previous isolation of a null mutation in the gene encoding TpIc3, cycA, in Desulfovibrio alaskensis G20. Whereas respiratory growth of the CycA mutant with lactate and sulfate was little affected, growth with pyruvate and sulfate was significantly impaired. We have explored the phenotype of the CycA mutant through physiological tests and transcriptomic and proteomic analyses. Data reported here show that electrons from pyruvate oxidation do not reach adenylyl sulfate reductase, the enzyme catalyzing the first redox reaction during sulfate reduction, in the absence of either CycA or the type I cytochrome c3:menaquinone oxidoreductase transmembrane complex, QrcABCD. In contrast to the wild type, the CycA and QrcA mutants did not grow with H2 or formate and sulfate as the electron acceptor. Transcriptomic and proteomic analyses of the CycA mutant showed that transcripts and enzymes for the pathway from pyruvate to succinate were strongly decreased in the CycA mutant regardless of the growth mode. Neither the CycA nor the QrcA mutant grew on fumarate alone, consistent with the omics results and a redox regulation of gene expression. We conclude that TpIc3 and the Qrc complex are D. alaskensis components essential for the transfer of electrons released in the periplasm to reach the cytoplasmic adenylyl sulfate reductase and present a model that may explain the CycA phenotype through confurcation of electrons.

  17. Effect of heparan sulfate and gold nanoparticles on muscle development during embryogenesis

    DEFF Research Database (Denmark)

    Zielinska, Marlena; Sawosz, Ewa; Grodzik, Marta

    2011-01-01

    Purpose: It was hypothesized that heparan sulfate (HS) as an essential compound for myogenesis and nanoparticles of gold (nano-Au) ashighly reactive compounds can affect muscle development as a consequence of molecular regulation of muscle cell formation, and that these effects may be enhanced by...

  18. Immobilization of cobalt by sulfate-reducing bacteria in subsurface sediments

    Science.gov (United States)

    Krumholz, Lee R.; Elias, Dwayne A.; Suflita, Joseph M.

    2003-01-01

    We investigated the impact of sulfate-reduction on immobilization of metals in subsurface aquifers. Co 2+ was used as a model for heavy metals. Factors limiting sulfate-reduction dependent Co 2+ immobilization were tested on pure cultures of sulfate-reducing bacteria, and in sediment columns from a landfill leachate contaminated aquifer. In the presence of 1 mM Co 2+ , the growth of pure cultures of sulfate-reducing bacteria was not impacted. Cultures of Desulfovibrio desulfuricans, Desulfotomaculum gibsoniae , and Desulfomicrobium hypogeia removed greater than 99.99% of the soluble Co 2+ when CoCl 2 was used with no chelators. The above cultures and Desulfoarcula baarsi removed 98-99.94% of the soluble Co(II) when the metal was complexed with the model ligand nitrilotriacetate (Co-NTA). Factors controlling the rate of sulfate-reduction based Co 2+ precipitation were investigated in sediment-cobalt mixtures. Several electron donors were tested and all but toluene accelerated soluble Co 2+ loss. Ethanol and formate showed the greatest stimulation. All complex nitrogen sources tested slowed and decreased the extent of Co 2+ removal from solution relative to formate-amended sediment incubations. A range of pH values were tested (6.35-7.81), with the more alkaline incubations exhibiting the largest precipitation of Co 2+ . The immobilization of Co 2+ in sediments was also investigated with cores to monitor the flow of Co 2+ through undisturbed sediments. An increase in the amount of Co 2+ immobilized as CoS was observed as sulfate reduction activity was stimulated in flow through columns. Both pure culture and sediment incubation data indicate that stimulation of sulfate reduction is a viable strategy in the immobilization of contaminating metals in subsurface systems.

  19. Use of Vancomycin-Impregnated Calcium Sulfate in the Treatment of Osteomyelitis of the Jaw.

    Science.gov (United States)

    Sun, Hai-Jiang; Xue, Lei; Wu, Chuan-Bin; Zhou, Qing

    2017-01-01

    The aim of this study was to describe the effect of vancomycin-impregnated calcium sulfate in the treatment of osteomyelitis of the jaw. Twelve patients who were diagnosed with osteomyelitis of the jaw underwent treatment with vancomycin-impregnated calcium sulfate since July 2014 at the Department of Oral and Maxillofacial Surgery, School of Stomatology, China Medical University (Shenyang, China). All patients underwent debridement of nonviable bone and implantation of vancomycin-impregnated calcium sulfate. The wounds were covered with an acellular dermal matrix and sutured. Ten patients had satisfactory wound healing. However, 2 cases of maxillary central osteomyelitis had delayed wound healing. The wounds healed after the surgical site was resutured under local anesthesia. At 3 months, the panoramic radiograph showed that most implants had been reabsorbed and replaced by new bone formation. All patients in this study had no recurrence of infection at 6 to 18 months (mean, 10.8 months) of follow-up. The use of vancomycin-impregnated calcium sulfate in the surgical debridement site for chronic osteomyelitis of the jaw has shown encouraging results. In addition, calcium sulfate can promote the formation of new bone to a certain extent. Copyright © 2016 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  20. Preparation of esters of gallic acid with higher primary alcohols

    NARCIS (Netherlands)

    Kerk, G.J.M. van der; Verbeek, J.H.; Cleton, J.C.F.

    1951-01-01

    The esters of gallic acid and higher primary alcohols, especially fatty alcohols, have recently gained considerable interest as possible antioxidants for fats. Two independent methods for the preparation of these esters are described. In the first method the hitherto unknown compound galloyl

  1. Production of both esters and biogas from Mexican poppy

    African Journals Online (AJOL)

    AJL

    esters, use oils of plant origin like vegetable oils and tree born oil seeds are ... Usage of ester will allow a balance to be sought between agriculture .... Sci. Technol. Plastic tube. Stopper. Glass bottle. (1 liter capacity). Rubber cap. Gas collector. Digester. Displaced water. Figure 1. Reactor design (see experimental set up).

  2. Alternative Production of Fatty Acid Methyl Esters from Triglycerides ...

    African Journals Online (AJOL)

    The catalysts activity was tested in thermocatalytic cracking of triglyceride; a direct conversion process for fatty acid methyl esters (biodiesel). The SZ1 not only exhibited higher conversion of triglycerides but higher fatty acid methyl esters (FAMEs) yields of approximately 59% after 3h as compared to SZ2 (32%). In addition ...

  3. Effect of Sucrose Esters on the Physicochemical Properties of Wheat ...

    African Journals Online (AJOL)

    HP

    modified starch were analyzed by Fourier transform infrared spectroscopy (FITR), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). Results: The properties of wheat starch changed greatly by adding different sucrose esters to their structures. Starch containing 0.30 % sucrose esters had the ...

  4. Phthalic acid esters found in municipal organic waste

    DEFF Research Database (Denmark)

    Hartmann, Hinrich; Ahring, Birgitte Kiær

    2003-01-01

    Contamination of the organic fraction of municipal solid waste (OFMSW) with xenobiotic compounds and their fate during anaerobic digestion was investigated. The phthalic acid ester di-(2- ethylhexyl)phthalate (DEHP) was identified as the main contaminant in OFMSW in concentrations more than half...... matter with high biogas yields and efficient reduction of the phthalic acid ester contamination....

  5. Determination of Phthalate Esters in the Aquatic Environment ...

    African Journals Online (AJOL)

    The use of solid phase extraction and capillary GLC provides the basis for selective determination of phthalate ester plasticizers in rivers and marine water samples. Of the several solvent ratios (methanol in dichloromethane) that were tried for selective elution of phthalate esters from the C18 solid phase glass catridge, the ...

  6. Protective effect of glucosamine cyclohexyl ester on osteoarthritis in ...

    African Journals Online (AJOL)

    Purpose: To investigate the therapeutic effect of glucosamine cyclohexyl ester on osteoarthritis (OA) in a rat model. Methods: Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot assays were used to analyze the effect of glucosamine cyclohexyl ester on changes in mRNA and protein ...

  7. Effect of Sucrose Esters on the Physicochemical Properties of Wheat ...

    African Journals Online (AJOL)

    HP

    International Pharmaceutical Abstract, Chemical Abstracts, Embase, Index Copernicus, EBSCO, African Index. Medicus, JournalSeek .... Table 1: Rapid visco-analyzer parameters for wheat starch modified with sucrose esters. Content of sucrose esters δ%ε. Peak. (cP). Trough. (cP). Breakdown. (cP). Final. (cP). Setback.

  8. Distribution of phthalate esters in underground water from power ...

    African Journals Online (AJOL)

    This study investigates the distribution of phthalateacid esters (PAEs) in groundwater from some power stations in Delta State. Groundwater samples were collected from eight power transmission and distribution stations. Concentrations (μg/L) of six phthalate acid esters compounds in the groundwater ranged from ...

  9. Protective effect of glucosamine cyclohexyl ester on osteoarthritis in ...

    African Journals Online (AJOL)

    Purpose: To investigate the therapeutic effect of glucosamine cyclohexyl ester on osteoarthritis (OA) in a rat model. Methods: Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot assays were used to analyze the effect of glucosamine cyclohexyl ester on changes in mRNA and.

  10. Sulfated chitin and chitosan as novel biomaterials.

    Science.gov (United States)

    Jayakumar, R; Nwe, N; Tokura, S; Tamura, H

    2007-02-20

    Chitin and chitosan are known to be natural polymers and they are non-toxic, biodegradable and biocompatible. Chemical modification of chitin and chitosan with sulfate to generate new bifunctional materials is of interest because the modification would not change the fundamental skeleton of chitin and chitosan, would keep the original physicochemical and biochemical properties and finally would bring new or improved properties. The sulfated chitin and chitosan have a variety of applications, such as, adsorbing metal ions, drug delivery systems, blood compatibility, and antibacterial field. The purpose of this review is to take a closer look about the different synthetic methods and potential applications of sulfated chitin and chitosan. Based on current research and existing products, some new and futuristic approaches in this context area are discussed in detail. From the studies reviewed, we concluded that sulfated chitin and chitosan are promising materials for biomedical applications.

  11. ROE Wet Sulfate Deposition 2009-2011

    Data.gov (United States)

    U.S. Environmental Protection Agency — The raster data represent the amount of wet sulfate deposition in kilograms per hectare from 2009 to 2011. Summary data in this indicator were provided by EPA’s...

  12. Sulfate reduction and methanogenesis at a freshwater

    DEFF Research Database (Denmark)

    Iversen, Vibeke Margrethe Nyvang; Andersen, Martin Søgaard; Jakobsen, Rasmus

    The freshwater-seawater interface was studied in a ~9-m thick anaerobic aquifer located in marine sand and gravel with thin peat lenses. Very limited amounts of iron-oxides are present. Consequently, the dominating redox processes are sulfate reduction and methanogenesis, and the groundwater...... is enriched in dissolved sulfide, methane and bicarbonate. Under normal conditions the seawater-freshwater interface is found at a depth of 4 m at the coastline and reaches the bottom of the aquifer 40 m inland. However, occasional flooding of the area occurs, introducing sulfate to the aquifer. Groundwater...... chemistry was studied in a 120 m transect perpendicular to the coast. Cores were taken for radiotracer rate measurements of sulfate reduction and methanogenesis. In the saline part of the aquifer 35 m inland, sulfate reduction was the dominant process with rates of 0.1-10 mM/year. In the freshwater part 100...

  13. Rapid NIR determination of alkyl esters in virgin olive oil

    International Nuclear Information System (INIS)

    Cayuela, J.A.

    2017-01-01

    The regulation of The European Union for olive oil and olive pomace established the limit of 35 mg·kg-1 for fatty acids ethyl ester contents in extra virgin olive oils, from grinding seasons after 2016. In this work, predictive models have been established for measuring fatty acid ethyl and methyl esters and to measure the total fatty acid alkyl esters based on near infrared spectroscopy (NIRS), and used successfully for this purpose. The correlation coefficients from the external validation exercises carried out with these predictive models ranged from 0.84 to 0.91. Different classification tests using the same models for the thresholds 35 mg·kg-1 for fatty acid ethyl esters and 75 mg·kg-1 for fatty acid alkyl esters provided success percentages from 75.0% to 95.2%. [es

  14. Can magnesium sulfate therapy impact lactogenesis?

    Science.gov (United States)

    Haldeman, W

    1993-12-01

    This case report describes a patient who ingested magnesium sulfate (MgSO4) for approximately four days as a treatment for pregnancy-induced hypertension. Stage II lactogenesis was delayed until the tenth postpartum day at which point the patient's breasts became fully engorged. No explanation for this delay was found, other than the possibility that magnesium sulfate treatment impeded lactogenesis. Implications for professionals who care for lactating women are discussed.

  15. Magnesium sulfate therapy in preeclampsia and eclampsia.

    Science.gov (United States)

    Witlin, A G; Sibai, B M

    1998-11-01

    To review the available evidence regarding efficacy, benefits, and risks of magnesium sulfate seizure prophylaxis in women with preeclampsia or eclampsia. The English-language literature in MEDLINE was searched from 1966 through February 1998 using the terms "magnesium sulfate," "seizure," "preeclampsia," "eclampsia," and "hypertension in pregnancy." Reviews of bibliographies of retrieved articles and consultation with experts in the field provided additional references. All relevant English-language clinical research articles retrieved were reviewed. Randomized controlled trials, retrospective reviews, and observational studies specifically addressing efficacy, benefits, or side effects of magnesium sulfate therapy in preeclampsia or eclampsia were chosen. Nineteen randomized controlled trials, five retrospective studies, and eight observational reports were reviewed. The criteria used for inclusion were as follows: randomized controlled trials evaluating use of magnesium sulfate in eclampsia, preeclampsia, and hypertensive disorders of pregnancy; nonrandomized studies of historical interest; "classic" observational studies; and recent retrospective studies evaluating efficacy of magnesium sulfate therapy, using relative risk and 95% confidence intervals where applicable. Magnesium sulfate therapy has been associated with increased length of labor, increased cesarean delivery rate, increased postpartum bleeding, increased respiratory depression, decreased neuromuscular transmission, and maternal death from overdose. A summary of randomized, controlled trials in women with eclampsia reveals recurrent seizures in 216 (23.1%) of 935 women treated with phenytoin or diazepam, compared with recurrent seizures in only 88 (9.4%) of 932 magnesium-treated women. Randomized controlled trials in women with severe preeclampsia collectively revealed seizures in 22 (2.8%) of 793 women treated with antihypertensive agents, compared with seizures in only seven of 815 (0

  16. Analysis of testosterone fatty acid esters in the digestive gland of mussels by liquid chromatography-high resolution mass spectrometry.

    Science.gov (United States)

    Guercia, Cesare; Cianciullo, Piergiorgio; Porte, Cinta

    2017-07-01

    Several studies have indicated that up to 70% of the total steroids detected in molluscs are in the esterified form and that pollutants, by modifying the esterification of steroids with fatty acids, might act as endocrine disrupters. However, despite the strong physiological significance of this process, there is almost no information on which fatty acids form the steroid esters and how this process is modulated. This study (a) investigates the formation of fatty acid esters of testosterone in digestive gland microsomal fractions of the mussel Mytilus galloprovincialis incubated with either palmitoly-CoA or CoA and ATP, and (b) assesses whether the endocrine disruptor tributyltin (TBT) interferes with the esterification of testosterone. Analysis of testosterone esters was performed by liquid chromatography-high resolution mass spectrometry (UPLC-HRMS). When microsomal fractions were incubated with testosterone and palmitoly-CoA, the formation of testosterone palmitate was detected. However, when microsomes were incubated with CoA and ATP, and no exogenous activated fatty acid was added, the synthesis of 16:0, 16:1, 20:5 and 22:6 testosterone esters was observed. The presence of 100µM TBT in the incubation mixture did not significantly alter the esterification of testosterone. These results evidence the conjugation of testosterone with the most abundant fatty acids in the digestive gland microsomal fraction of mussels. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Toxicity of copper sulfate and zinc sulfate to Macrobrachium lamarrel (H. Miline Edwards) (Decapoda, Palaemonidae)

    Energy Technology Data Exchange (ETDEWEB)

    Murti, R.; Shukla, G.S.

    1984-09-01

    Macrobrachium lamarrei were exposed to six different concentrations of copper sulfate and zinc sulfate solutions. The specimens showed increased activity immediately after their transfer to the test solutions. They subside their activity very soon in copper sulfate, whereas in zinc sulfate they remain active for about 2 hr frequently coming to the surface of the toxic solution. In both cases, profuse secretion of mucus has been noted on the whole body surface, but most pronounced in the gill region. The 96 h LC/sub 50/ values of copper sulfate (0.247 mg/l) and zinc sulfate (3.188 mg/l) show that copper is thirteen times more toxic to this species than zinc. The minimum concentration of zinc sulfate to initiate slight mortality was 1 mg/l while for copper the corresponding value was as low as 0.01 mg/l. The first mortality in copper sulfate solution of 0.5 mg/l was noted after 4 hr exposure in contrast to zinc sulfate where it required 6 hr in 15 mg/l solutions. 27 references, 2 tables.

  18. Effect of metakaolin on external sulfate attack

    Energy Technology Data Exchange (ETDEWEB)

    Ramlochan, T.; Thomas, M. [Toronto Univ., Dept. of Civil Engineering, ON (Canada)

    2000-07-01

    The effect of high reactivity metakaolin (HRM) on the sulfate resistance of mortars was studied. Mortar bars with three cements of varying C{sub 3}A content were used for the experiment. After a six month exposure to a 5 per cent solution of sodium sulfate, mortar bars incorporating any level of HRM as a partial replacement for a high-C{sub 3}A was considered 'moderately sulfate resistant'; mortar bars with HRM and a moderate or low C{sub 3}A content as 'high sulfate resistant'. It was also determined that for long term sulfate resistance 15 per cent HRM or more may be required, depending on the C{sub 3}A content. The performance of HRM was found to be significantly influenced by the water-cementitious material ratio, and in turn, by permeability, suggesting that HRM might increase sulfate resistance more by lowering the permeability of the concrete than by any chemical action. 7 refs., 4 tabs., 7 figs.

  19. Ammonium sulfate preparation from phosphogypsum waste

    Directory of Open Access Journals (Sweden)

    Abdel-Hakim T. Kandil

    2017-01-01

    Full Text Available The Egyptian phosphogypsum waste is treated using sulfuric acid prior the ammonium sulfate production. The relevant factors that would affect the removal efficiencies of some impurities are studied. The optimum conditions of the treatment are 8 M sulfuric acid solution and 1/4 solid/liquid ratio for 30 min contact time at 80 °C. Moreover, the optimum conditions of the ammonium sulfate preparation are 10 g of the suspended impure or purified phosphogypsum in 40 ml of 3% ammonium sulfate solution (as initiator, 1/4 solid/liquid ratio at pH7 at an addition of an excess ammonium carbonate, and 150 rpm stirring speed for 4.0 h contact time at 55 °C as well as the 5 mg of barium chloride is added to remove the radium in the ammonium sulfate product. Finally, the ammonium sulfate is crystallized and the chemical analysis of the product shows 20% nitrogen and 23.6% sulfur. Therefore, the purity of the obtained ammonium sulfate is 95% from the purified phosphogypsum.

  20. A Sulfate Aerosol Trigger for the Sturtian Neoproterozoic Snowball Event

    Science.gov (United States)

    Wordsworth, R. D.; Macdonald, F. A.

    2017-12-01

    Despite the dominance of the carbon cycle in determining the evolution of Earth's climate in general, certain events defy easy explanation via atmospheric CO2 changes alone. Here we discuss the particular role that transient planetary albedo changes via sulfate aerosol formation can play in major climate transitions. Specifically, we propose that SO2 outgassing associated with the eruption of the Franklin Large Igneous Province (LIP) led to the first Neoproterozoic Snowball event, the Sturtian, 716 Ma. We summarize U/Pb zircon and baddeleyite dating indicating the synchronicity of the Franklin eruptions and the onset of the Sturtian, and paleomagnetic data indicating that the Franklin erupted close to the equator. We then discuss in detail the modeling we have performed of eruption rate, the plume height achieved during basaltic fissure volcanism, the chemistry and microphysics of sulfate aerosol formation, and the dependence of aerosol longwave and shortwave radiative effects on atmospheric loading, particle size and surface albedo. We discuss the critical importance of the latitude of eruption, the tropopause height, and ocean dynamics in determining the strength and sign of aerosol radiative forcing. We finish by comparing the Franklin event with other LIP emplacement events in Earth history and make suggestions for future modeling.

  1. Bacterial formation of phosphatic laminites off Peru.

    Science.gov (United States)

    Arning, E T; Birgel, D; Brunner, B; Peckmann, J

    2009-06-01

    Authigenic phosphatic laminites enclosed in phosphorite crusts from the shelf off Peru (10 degrees 01' S and 10 degrees 24' S) consist of carbonate fluorapatite layers, which contain abundant sulfide minerals including pyrite (FeS(2)) and sphalerite (ZnS). Low delta(34)S(pyrite) values (average -28.8 per thousand) agree with bacterial sulfate reduction and subsequent pyrite formation. Stable sulfur isotopic compositions of sulfate bound in carbonate fluorapatite are lower than that of sulfate from ambient sea water, suggesting bacterial reoxidation of sulfide by sulfide-oxidizing bacteria. The release of phosphorus and subsequent formation of the autochthonous phosphatic laminites are apparently caused by the activity of sulfate-reducing bacteria and associated sulfide-oxidizing bacteria. Following an extraction-phosphorite dissolution-extraction procedure, molecular fossils of sulfate-reducing bacteria (mono-O-alkyl glycerol ethers, di-O-alkyl glycerol ethers, as well as the short-chain branched fatty acids i/ai-C(15:0), i/ai-C(17:0) and 10MeC(16:0)) are found to be among the most abundant compounds. The fact that these molecular fossils of sulfate-reducing bacteria are distinctly more abundant after dissolution of the phosphatic laminite reveals that the lipids are tightly bound to the mineral lattice of carbonate fluorapatite. Moreover, compared with the autochthonous laminite, molecular fossils of sulfate-reducing bacteria are: (1) significantly less abundant and (2) not as tightly bound to the mineral lattice in the other, allochthonous facies of the Peruvian crusts consisting of phosphatic coated grains. These observations confirm the importance of sulfate-reducing bacteria in the formation of the phosphatic laminite. Model calculations highlight that organic matter degradation by sulfate-reducing bacteria has the potential to liberate sufficient phosphorus for phosphogenesis.

  2. Surface investigation and tribological mechanism of a sulfate-based lubricant deposited on zinc-coated steel sheets

    International Nuclear Information System (INIS)

    Timma, Christian; Lostak, Thomas; Janssen, Stella; Flock, Jörg; Mayer, Christian

    2016-01-01

    Highlights: • Skin-passed hot-dip galvanized (HDG-) steel sheets were coated with (NH 4 ) 2 SO 4 in a common roll-coating method. • A formation of (NH 4 ) 2 Zn(SO 4 ) * xH 2 O was observed and the reaction mainly occurred in the skin-passed areas of the surface. • Sulfate coated samples reveal a superior friction behaviour in oil-like conditions compared non-sulfated specimen. - Abstract: Phosphatation is a well-known technique to improve friction and wear behaviour of zinc coated steel, but has a variety of economic and ecologic limitations. In this study an alternative coating based on ammonium sulfate ((NH 4 ) 2 SO 4 ) is applied on skin-passed hot-dip galvanized steel sheets in order to investigate its surface chemical and tribological behaviour in a Pin-on-Disk Tribometer. Raman- and X-ray photoelectron spectroscopic results revealed a formation of ammonium zinc sulfate ((NH 4 ) 2 Zn(SO 4 ) 2 * xH 2 O) on the surface, which is primarily located in the skin-passed areas of the steel material. Sulfate coated samples exhibited a superior friction behaviour in Pin-on-Disk Tests using squalane as a model substance for oil-like lubricated conditions and a formation of a thin lubrication film is obtained in the wear track. Squalane acts as a carrier substance for ammonium zinc sulfate, leading to an effective lubrication film in the wear track.

  3. Methods of refining and producing dibasic esters and acids from natural oil feedstocks

    Energy Technology Data Exchange (ETDEWEB)

    Snead, Thomas E.; Cohen, Steven A.; Gildon, Demond L.

    2016-06-14

    Methods and systems for making dibasic esters and/or dibasic acids using metathesis are generally disclosed. In some embodiments, the methods comprise reacting a terminal olefin ester with an internal olefin ester in the presence of a metathesis catalyst to form a dibasic ester and/or dibasic acid. In some embodiments, the terminal olefin ester or the internal olefin ester are derived from a renewable feedstock, such as a natural oil feedstock. In some such embodiments, the natural oil feedstock, or a transesterified derivative thereof, is metathesized to make the terminal olefin ester or the internal olefin ester.

  4. Activated sludge degradation of adipic acid esters.

    Science.gov (United States)

    Saeger, V W; Kalley, R G; Hicks, O; Tucker, E S; Mieure, J P

    1976-01-01

    The biodegradability of three aliphatic adipic acid diesters and a 1,3-butylene glycol adipic acid polyester was determined in acclimated, activated sludge systems. Rapid primary biodegradation from 67 to 99+% was observed at 3- and 13-mg/liter feed levels for di-n-hexyl adipate, di(2-ethylhexyl) adipate, and di(heptyl, nonyl) adipate in 24 h. When acclimated, activated sludge microorganisms were employed as the seed for two carbon dioxide evolution procedures, greater than 75% of the theoretical carbon dioxide was evolved for the three diesters and the polyester in a 35-day test period. The essentially complete biodegradation observed in these studies suggests that these esters would not persist when exposed to similar mixed microbial populations in the environment. PMID:1275494

  5. Ketone ester effects on metabolism and transcription.

    Science.gov (United States)

    Veech, Richard L

    2014-10-01

    Ketosis induced by starvation or feeding a ketogenic diet has widespread and often contradictory effects due to the simultaneous elevation of both ketone bodies and free fatty acids. The elevation of ketone bodies increases the energy of ATP hydrolysis by reducing the mitochondrial NAD couple and oxidizing the coenzyme Q couple, thus increasing the redox span between site I and site II. In contrast, metabolism of fatty acids leads to a reduction of both mitochondrial NAD and mitochondrial coenzyme Q causing a decrease in the ΔG of ATP hydrolysis. In contrast, feeding ketone body esters leads to pure ketosis, unaccompanied by elevation of free fatty acids, producing a physiological state not previously seen in nature. The effects of pure ketosis on transcription and upon certain neurodegenerative diseases make approach not only interesting, but of potential therapeutic value.

  6. Organophosphorus ester-induced chronic neurotoxicity.

    Science.gov (United States)

    Abou-Donia, Mohamed B

    2003-08-01

    Organophosphorus compounds are potent neurotoxic chemicals that are widely used in medicine, industry, and agriculture. The neurotoxicity of these chemicals has been documented in accidental human poisoning, epidemiological studies, and animal models. Organophosphorus compounds have 3 distinct neurotoxic actions. The primary action is the irreversible inhibition of acetylcholinesterase, resulting in the accumulation of acetylcholine and subsequent overstimulation of the nicotinic and muscarinic acetylcholine receptors, resulting in cholinergic effects. Another action of some of these compounds, arising from single or repeated exposure, is a delayed onset of ataxia, accompanied by a Wallerian-type degeneration of the axon and myelin in the most distal portion of the longest tracts in both the central and peripheral nervous systems, and is known as organophosphorus ester-induced delayed neurotoxicity (OPIDN). In addition, since the introduction and extensive use of synthetic organophosphorus compounds in agriculture and industry half a century ago, many studies have reported long-term, persistent, chronic neurotoxicity symptoms in individuals as a result of acute exposure to high doses that cause acute cholinergic toxicity, or from long-term, low-level, subclinical doses of these chemicals. The author attempts to define the neuronal disorder that results from organophosphorus ester-induced chronic neurotoxicity (OPICN), which leads to long-term neurological and neurobehavioral deficits. Although the mechanisms of this neurodegenerative disorder have yet to be established, the sparse available data suggest that large toxic doses of organophosphorus compounds cause acute necrotic neuronal cell death in the brain, whereas sublethal or subclinical doses produce apoptotic neuronal cell death and involve oxidative stress.

  7. The Glutathione Derivative, GSH Monoethyl Ester, May Effectively Whiten Skin but GSH Does Not

    Directory of Open Access Journals (Sweden)

    Bo Young Chung

    2016-04-01

    Full Text Available Glutathione in its reduced form (GSH is an antioxidant and also is involved in pheomelanin formation. Thus, it has been long believed that GSH has a skin whitening effect. However, its actual or direct effect is unproven. We evaluated the anti-melanogenic effects of GSH and its derivatives in vitro. We examined change of melanogenesis and its related proteins by GSH itself and its derivatives, including GSH monoethyl ester (GSH-MEE, GSH diethyl ester (GSH-DEE and GSH monoisopropyl ester (GSH-MIPE in Melan-A cells, Mel-Ab cells, and B16F10 cells. GSH and GSH-MEE did not display cytotoxic activity, but GSH-MIPE and GSH-DEE did. Intriguingly, GSH itself had no inhibitory effect on melanin production or intracellular tyrosinase activity. Rather, it was GSH-MEE and GSH-MIPE that profoundly reduced the amount of melanin and intracellular tyrosinase activity. Thus, GSH-MEE was selected as a suitable candidate skin-whitening agent and it did not alter melanogenesis-associated proteins such as microphthalmia-associated transcription factor (MITF, tyrosinase, tyrosinase-related protein (TRP-1, and TRP-2, but it did increase the amount of suggested pheomelanin and suggested pheomelanin/eumelanin ratio. GSH-MEE was effective for anti-melanogenesis, whereas GSH itself was not. GSH-MEE could be developed as a safe and efficient agent for the treatment of hyperpigmentation skin disorders.

  8. Methyl Ester Production via Heterogeneous Acid-Catalyzed Simultaneous Transesterification and Esterification Reactions

    Science.gov (United States)

    Indrayanah, S.; Erwin; Marsih, I. N.; Suprapto; Murwani, I. K.

    2017-05-01

    The heterogeneous acid catalysts (MgF2 and ZnF2) have been used to catalyze the simultaneous transesterification and esterification reactions of crude palm oil (CPO) with methanol. Catalysts were synthesized by sol-gel method (combination of fluorolysis and hydrolysis). The physicochemical, structural, textural, thermal stability of the prepared catalysts was investigated by N2 adsorption-desorption, XRD, FT-IR, SEM and TG/DTG. Both MgF2 and ZnF2 have rutile structures with a different phase. The surface area of ZnF2 is smaller than that of MgF2, but the pore size and volume of ZnF2 are larger than those of MgF2. However, these materials are thermally stable. The performance of the catalysts is determined from the yield of catalysts toward the formation of methyl ester determined based on the product of methyl ester obtained from the reaction. The catalytic activity of ZnF2 is higher than MgF2 amounted to 85.21% and 26.82% with the optimum condition. The high activity of ZnF2 could be attributed to its pore diameter and pore volume but was not correlated with its surface area. The yield of methyl ester decreased along with the increase in molar ratio of methanol/CPO from 85.21 to 80.99 for ZnF2, respectively.

  9. Statistical Evaluation of HTS Assays for Enzymatic Hydrolysis of β-Keto Esters.

    Directory of Open Access Journals (Sweden)

    O Buß

    Full Text Available β-keto esters are used as precursors for the synthesis of β-amino acids, which are building blocks for some classes of pharmaceuticals. Here we describe the comparison of screening procedures for hydrolases to be used for the hydrolysis of β-keto esters, the first step in the preparation of β-amino acids. Two of the tested high throughput screening (HTS assays depend on coupled enzymatic reactions which detect the alcohol released during ester hydrolysis by luminescence or absorption. The third assay detects the pH shift due to acid formation using an indicator dye. To choose the most efficient approach for screening, we assessed these assays with different statistical methods-namely, the classical Z'-factor, standardized mean difference (SSMD, the Kolmogorov-Smirnov-test, and t-statistics. This revealed that all three assays are suitable for HTS, the pH assay performing best. Based on our data we discuss the explanatory power of different statistical measures. Finally, we successfully employed the pH assay to identify a very fast hydrolase in an enzyme-substrate screening.

  10. Occurrence of fatty acid short-chain-alkyl esters in fruits of Celastraceae plants.

    Science.gov (United States)

    Sidorov, Roman A; Zhukov, Anatoly V; Pchelkin, Vasily P; Vereshchagin, Andrei G; Tsydendambaev, Vladimir D

    2013-06-01

    Small amounts of a mixture of fatty acid short-chain-alkyl esters (FASCAEs) were obtained from the fruits of twelve plant species of Celastraceae family, and in five of them the FASCAEs were present not only in the arils but also in the seeds. These mixtures contained 32 individual FASCAE species, which formed four separate fractions, viz. FA methyl, ethyl, isopropyl, and butyl esters (FAMEs, FAEEs, FAIPEs, and FABEs, resp.). The FASCAE acyl components included the residues of 16 individual C₁₄-C₂₄ saturated, mono-, di-, and trienoic FAs. Linoleic, oleic, and palmitic acids, and, in some cases, also α-linolenic acid predominated in FAMEs and FAEEs, while myristic acid was predominant in FAIPEs. It can be suggested that, in the fruit arils of some plant species, FAMEs and FAEEs were formed at the expense of a same FA pool characteristic of a given species and were strongly different from FAIPEs and FABEs esters regarding the mechanism of their biosynthesis. However, as a whole, the qualitative and quantitative composition of various FASCAE fractions, as well as their FA composition, varied considerably depending on various factors. Therefore, separate FASCAE fractions seem to be synthesized from different FA pools other than those used for triacylglycerol formation. Copyright © 2013 Verlag Helvetica Chimica Acta AG, Zürich.

  11. Detection of stanozolol O- and N-sulfate metabolites and their evaluation as additional markers in doping control.

    Science.gov (United States)

    Balcells, Georgina; Matabosch, Xavier; Ventura, Rosa

    2017-07-01

    Stanozolol (STAN) is one of the most frequently detected anabolic androgenic steroids in sports drug testing. STAN misuse is commonly detected by monitoring metabolites excreted conjugated with glucuronic acid after enzymatic hydrolysis or using direct detection by liquid chromatography-tandem mass spectrometry (LC-MS/MS). It is well known that some of the previously described metabolites are the result of the formation of sulfate conjugates in C17, which are converted to their 17-epimers in urine. Therefore, sulfation is an important phase II metabolic pathway of STAN that has not been comprehensively studied. The aim of this work was to evaluate the sulfate fraction of STAN metabolism by LC-MS/MS to establish potential long-term metabolites valuable for doping control purposes. STAN was administered to six healthy male volunteers involving oral or intramuscular administration and urine samples were collected up to 31 days after administration. Sulfation of the phase I metabolites commercially available as standards was performed in order to obtain MS data useful to develop analytical strategies (neutral loss scan, precursor ion scan and selected reaction monitoring acquisitions modes) to detect potential sulfate metabolites. Eleven sulfate metabolites (M-I to M-XI) were detected and characterized by LC-MS/MS. This paper provides valuable data on the ionization and fragmentation of O-sulfates and N-sulfates. For STAN, results showed that sulfates do not improve the retrospectivity of the detection compared to the previously described long-term metabolite (epistanozolol-N-glucuronide). However, sulfate metabolites could be additional markers for the detection of STAN misuse. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  12. Oxygen isotopic fractionation during bacterial sulfate reduction

    Science.gov (United States)

    Balci, N.; Turchyn, A. V.; Lyons, T.; Bruchert, V.; Schrag, D. P.; Wall, J.

    2006-12-01

    Sulfur isotope fractionation during bacterial sulfate reduction (BSR) is understood to depend on a variety of environmental parameters, such as sulfate concentration, temperature, cell specific sulfate reduction rates, and the carbon substrate. What controls oxygen isotope fractionation during BSR is less well understood. Some studies have suggested that carbon substrate is important, whereas others concluded that there is a stoichiometric relationship between the fractionations of sulfur and oxygen during BSR. Studies of oxygen fractionation are complicated by isotopic equilibration between sulfur intermediates, particularly sulfite, and water. This process can modify the isotopic composition of the extracellular sulfate pool (δ18OSO4 ). Given this, the challenge is to distinguish between this isotopic equilibration and fractionations linked to the kinetic effects of the intercellular enzymes and the incorporation of sulfate into the bacterial cell. The δ18OSO4 , in concert with the sulfur isotope composition of sulfate (δ34SSO4), could be a powerful tool for understanding the pathways and environmental controls of BSR in natural systems. We will present δ18OSO4 data measured from batch culture growth of 14 different species of sulfate reducing bacteria for which sulfur isotope data were previously published. A general observation is that δ18OSO4 shows little isotopic change (kinetic effect during BSR and/or equilibration between sulfur intermediates and the isotopically light water (~-5‰) of the growth medium. Our present batch culture data do not allow us to convincingly isolate the magnitude and the controlling parameters of the kinetic isotope effect for oxygen. However, ongoing growth of mutant bacteria missing enzymes critical in the different steps of BSR may assist in this mission.

  13. Reactive Uptake of Dimethylamine by Ammonium Sulfate and Ammonium Sulfate-Sucrose Mixed Particles.

    Science.gov (United States)

    Chu, Yangxi; Chan, Chak K

    2017-01-12

    Short-chain alkyl amines can undergo gas-to-particle partitioning via reactive uptake by ammonium salts, whose phases have been thought to largely influence the extent of amine uptake. Previous studies mainly focused on particles of single ammonium salt at either dry or wet conditions without any addition of organic compounds. Here we report the uptake of dimethylamine (DMA) by ammonium sulfate (AS) and AS-sucrose mixed particles at different relative humidities (RHs) using an electrodynamic balance coupled with in situ Raman spectroscopy. DMA is selected as a representative of short-chain alkyl amines, and sucrose is used as a surrogate of viscous and hydrophilic organics. Effective DMA uptake was observed for most cases, except for the water-limiting scenario at <5% RH and the formation of an ultraviscous sucrose coating at 10% RH and below. DMA uptake coefficients (γ) were estimated using the particle mass measurements during DMA uptake. Addition of sucrose can increase γ by absorbing water or inhibiting AS crystallization and decrease γ by elevating the particle viscosity and forming a coating layer. DMA uptake can be facilitated for crystalline AS or retarded for aqueous AS with hydrophilic viscous organics (e.g., secondary organic material formed via the oxidation of biogenic volatile organic compounds) present in aerosol particles.

  14. A potential role for chondroitin sulfate/dermatan sulfate in arm regeneration in Amphiura filiformis

    NARCIS (Netherlands)

    Ramachandra, R.; Namburi, R.B.; Dupont, S.T.; Ortega-Martinez, O.; Kuppevelt, T.H. van; Lindahl, U.; Spillmann, D.

    2017-01-01

    Glycosaminoglycans (GAGs), such as chondroitin sulfate (CS) and dermatan sulfate (DS) from various vertebrate and invertebrate sources are known to be involved in diverse cellular mechanisms during repair and regenerative processes. Recently, we have identified CS/DS as the major GAG in the

  15. Thermal and mechanical properties of fatty acid starch esters.

    Science.gov (United States)

    Winkler, H; Vorwerg, W; Rihm, R

    2014-02-15

    The current study examined thermal and mechanical properties of fatty acid starch esters (FASEs). All highly soluble esters were obtained by the sustainable, homogeneous transesterification of fatty acid vinyl esters in dimethylsulfoxide (DMSO). Casted films of products with a degree of substitution (DS) of 1.40-1.73 were compared with highly substituted ones (DS 2.20-2.63). All films were free of any plasticizer additives. Hydrophobic surfaces were characterized by contact angle measurements. Dynamic scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA) revealed thermal transitions (T(g), T(m)) which were influenced by the internal plasticizing effect of the ester groups. Thermal gravimetric analysis (TGA) measurements showed the increased thermal stability toward native starch. Tensile tests revealed the decreasing strength and stiffness of the products with increasing ester-group chain length while the elongation increased up to the ester group laurate and after that decreased. Esters of the longest fatty acids, palmitate and stearate turned out to be brittle materials due to super molecular structures of the ester chains such as confirmed by X-ray. Summarized products with a DS 1.40-1.73 featured more "starch-like" properties with tensile strength up to outstanding 43 MPa, while products with a DS >2 behaved more "oil-like". Both classes of esters should be tested as a serious alternative to commercial starch blends and petrol-based plastics. The term Cnumber is attributed to the number of total C-Atoms of the fatty acid (e.g. C6=Hexanoate). Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Sulfated Titania Nanoparticles: an Efficient Catalyst for the Synthesis of Polyhydroquinoline Derivatives through Hantzsch Multicomponent Reaction

    Directory of Open Access Journals (Sweden)

    A. Tadjarodi

    2015-10-01

    Full Text Available Sulfated titania nanoparticles (SO42-/TiO2 NPs were synthesized using titanium tetraisopropoxide (TTIP by the sol-gel method. The structure and morphology of the prepared nanocatalyst was characterized using X-ray diffraction (XRD, scanning electron microscopy (SEM and Brunauer–Emmett–Teller (BET methods as well as Fourier transform infrared (FT-IR and energy dispersive X-ray (EDX spectroscopy. The obtained nanoparticles were used as an efficient, reusable and environmentally friendly catalyst for the synthesis of polyhydroquinoline (PHQ derivatives via a one-pot multicomponent reaction of various aldehydes, ammonium acetate and 1,3-dicarbonyl compounds under reflux conditions. The desired Hantzsch esters were obtained in good to excellent yields and short reaction times. The SO42- /TiO2 NPs could be recycled at least three times without significant loss of their catalytic activity.

  17. Boric Ester-Type Molten Salt via Dehydrocoupling Reaction

    OpenAIRE

    Noriyoshi Matsumi; Yoshiyuki Toyota; Prerna Joshi; Puhup Puneet; Raman Vedarajan; Toshihiro Takekawa

    2014-01-01

    Novel boric ester-type molten salt was prepared using 1-(2-hydroxyethyl)-3-methylimidazolium chloride as a key starting material. After an ion exchange reaction of 1-(2-hydroxyethyl)-3-methylimidazolium chloride with lithium (bis-(trifluoromethanesulfonyl) imide) (LiNTf2), the resulting 1-(2-hydroxyethyl)-3-methylimidazolium NTf2 was reacted with 9-borabicyclo[3.3.1]nonane (9-BBN) to give the desired boric ester-type molten salt in a moderate yield. The structure of the boric ester-type molt...

  18. Catalytic Oxidation of Allylic Alcohols to Methyl Esters

    DEFF Research Database (Denmark)

    Gallas-Hulin, Agata; Kotni, Rama Krishna; Nielsen, Martin

    2017-01-01

    Aerobic oxidation of allylic alcohols to methyl esters using gold nanoparticles supported on different metal oxide carriers has been performed successfully under mild conditions (room temperature, 0.1 MPa O2) without significant loss of catalytic activity. The effects of different reaction...... parameters are studied to find the suitable reaction conditions. All catalysts are characterised by XRD, XRF and TEM. Among these catalysts, Au/TiO2 showed the most efficient catalytic activity towards the selective oxidation of allylic alcohols to the corresponding esters. Moreover, the same Au/TiO2...... to synthesize methyl esters from allylic alcohols....

  19. Sugar ester surfactants: enzymatic synthesis and applications in food industry.

    Science.gov (United States)

    Neta, Nair S; Teixeira, José A; Rodrigues, Lígia R

    2015-01-01

    Sugar esters are non-ionic surfactants that can be synthesized in a single enzymatic reaction step using lipases. The stability and efficiency of lipases under unusual conditions and using non-conventional media can be significantly improved through immobilization and protein engineering. Also, the development of de novo enzymes has seen a significant increase lately under the scope of the new field of synthetic biology. Depending on the esterification degree and the nature of fatty acid and/or sugar, a range of sugar esters can be synthesized. Due to their surface activity and emulsifying capacity, sugar esters are promising for applications in food industry.

  20. Acyl-lupeol esters from Parahancornia amapa (Apocynaceae

    Directory of Open Access Journals (Sweden)

    Carvalho Mário G. de

    2001-01-01

    Full Text Available From the roots of Parahancornia amapa, family Apocynaceae, the following compounds were isolated and identified nine new and ten known 3beta-O-acyl lupeol esters, beta-sitosterol, stigmasterol, beta-sitosterone, the triterpenoids beta-amyrin, alpha-amyrin, lupeol and their acetyl derivatives. The structures of these compounds were established by spectroscopic data, mainly ¹H and 13C (HBBD and DEPT NMR spectra. The methyl esters obtained by hydrolysis of acyl lupeol esters and methylation of the corresponding acids were characterized by MS-GC analysis.

  1. Modeling of sulfation of potassium chloride by ferric sulfate addition during grate-firing of biomass

    DEFF Research Database (Denmark)

    Wu, Hao; Jespersen, Jacob Boll; Aho, Martti

    2013-01-01

    Potassium chloride, KCl, formed from critical ash-forming elements released during combustion may lead to severe ash deposition and corrosion problems in biomass-fired boilers. Ferric sulfate, Fe2(SO4)3 is an effective additive, which produces sulfur oxides (SO2 and SO3) to convert KCl to the less...... harmful K2SO4. In the present study the decomposition of ferric sulfate is studied in a fast-heating rate thermogravimetric analyzer (TGA), and a kinetic model is proposed to describe the decomposition process. The yields of SO2 and SO3 from ferric sulfate decomposition are investigated in a laboratory......-scale tube reactor. It is revealed that approximately 40% of the sulfur is released as SO3, the remaining fraction being released as SO2. The proposed decomposition model of ferric sulfate is combined with a detailed gas phase kinetic model of KCl sulfation, and a simplified model of K2SO4 condensation...

  2. Role of cholesterol sulfate in epidermal structure and function: Lessons from X-linked ichthyosis☆

    Science.gov (United States)

    Elias, Peter M.; Williams, Mary L.; Choi, Eung-Ho; Feingold, Kenneth R.

    2014-01-01

    X-linked ichthyosis is a relatively common syndromic form of ichthyosis most often due to deletions in the gene encoding the microsomal enzyme, steroid sulfatase, located on the short area of the X chromosome. Syndromic features are mild or unapparent unless contiguous genes are affected. In normal epidermis, cholesterol sulfate is generated by cholesterol sulfotransferase (SULT2B1b), but desulfated in the outer epidermis, together forming a ‘cholesterol sulfate cycle’ that potently regulates epidermal differentiation, barrier function and desquamation. In XLI, cholesterol sulfate levels my exceed 10% of total lipid mass (≈1% of total weight). Multiple cellular and biochemical processes contribute to the pathogenesis of the barrier abnormality and scaling phenotype in XLI. This article is part of a Special Issue entitled The Important Role of Lipids in the Epidermis and their Role in the Formation and Maintenance of the Cutaneous Barrier. Guest Editors: Kenneth R. Feingold and Peter Elias. PMID:24291327

  3. Oxygen isotope exchange with quartz during pyrolysis of silver sulfate and silver nitrate.

    Science.gov (United States)

    Schauer, Andrew J; Kunasek, Shelley A; Sofen, Eric D; Erbland, Joseph; Savarino, Joel; Johnson, Ben W; Amos, Helen M; Shaheen, Robina; Abaunza, Mariana; Jackson, Terri L; Thiemens, Mark H; Alexander, Becky

    2012-09-30

    Triple oxygen isotopes of sulfate and nitrate are useful metrics for the chemistry of their formation. Existing measurement methods, however, do not account for oxygen atom exchange with quartz during the thermal decomposition of sulfate. We present evidence for oxygen atom exchange, a simple modification to prevent exchange, and a correction for previous measurements. Silver sulfates and silver nitrates with excess (17)O were thermally decomposed in quartz and gold (for sulfate) and quartz and silver (for nitrate) sample containers to O(2) and byproducts in a modified Temperature Conversion/Elemental Analyzer (TC/EA). Helium carries O(2) through purification for isotope-ratio analysis of the three isotopes of oxygen in a Finnigan MAT253 isotope ratio mass spectrometer. The Δ(17)O results show clear oxygen atom exchange from non-zero (17)O-excess reference materials to zero (17)O-excess quartz cup sample containers. Quartz sample containers lower the Δ(17)O values of designer sulfate reference materials and USGS35 nitrate by 15% relative to gold or silver sample containers for quantities of 2-10 µmol O(2). Previous Δ(17)O measurements of sulfate that rely on pyrolysis in a quartz cup have been affected by oxygen exchange. These previous results can be corrected using a simple linear equation (Δ(17)O(gold) = Δ(17)O(quartz) * 1.14 + 0.06). Future pyrolysis of silver sulfate should be conducted in gold capsules or corrected to data obtained from gold capsules to avoid obtaining oxygen isotope exchange-affected data. Copyright © 2012 John Wiley & Sons, Ltd.

  4. A Detailed Chemical Kinetic Reaction Mechanism for Oxidation of Four Small Alkyl Esters in Laminar Premixed Flames

    Energy Technology Data Exchange (ETDEWEB)

    Westbrook, C K; Pitz, W J; Westmoreland, P R; Dryer, F L; Chaos, M; Osswald, P; Kohse-Hoinghaus, K; Cool, T A; Wang, J; Yang, B; Hansen, N; Kasper, T

    2008-02-08

    A detailed chemical kinetic reaction mechanism has been developed for a group of four small alkyl ester fuels, consisting of methyl formate, methyl acetate, ethyl formate and ethyl acetate. This mechanism is validated by comparisons between computed results and recently measured intermediate species mole fractions in fuel-rich, low pressure, premixed laminar flames. The model development employs a principle of similarity of functional groups in constraining the H atom abstraction and unimolecular decomposition reactions in each of these fuels. As a result, the reaction mechanism and formalism for mechanism development are suitable for extension to larger oxygenated hydrocarbon fuels, together with an improved kinetic understanding of the structure and chemical kinetics of alkyl ester fuels that can be extended to biodiesel fuels. Variations in concentrations of intermediate species levels in these flames are traced to differences in the molecular structure of the fuel molecules.

  5. 15th International Sunflower Conference Synthesis of new derivatives from vegetable sunflower oil methyl esters via epoxydation and oxirane opening

    Directory of Open Access Journals (Sweden)

    Pages Xavier

    2001-03-01

    Full Text Available Recently, epoxides have received increased attention because they are of interest both as end-products and as chemical intermediates; epoxidized oils, mainly High Oleic Sunflower Oil, and their ester derivatives have thus found important applications as plasticizers and additives for polyvinyl chloride (PVC. Epoxidized esters have been produced classically from High Oleic Sunflower Methyl Esters (HOSME using H2O2 and formic acid. The epoxidation reaches 90% on pilot scale (5kg. Epoxidized esters produced from HOSME have respectively hydroxyl values of 0, oxirane values of 5.2/4.5 and iodine values of 1.7/1.5. Cleavage trials of the oxirane group of the epoxidized esters with different reactants have been undertaken in order to produce on pilot scale new derivatives to be characterized and tested in different fields of application (lubrication, detergency and as chemical intermediates. Reaction of Epoxy-HOSME with an excess of oleic acid was conducted under atmospheric pressure without any catalyst and solvent. The oxirane opening leads to complete estolide formation: after neutralization, analytical controls (chemical values, GC and HPLC analysis indicate that the estolides are composed of a mixture of C36 (oleate of methyl hydroxystearate and C54 (di-oleate of methyl dihydroxystearate. Oxirane opening with alcohols (ethanol and octanol was preferentially performed by acid catalysis at 100°C under atmospheric pressure. Analytical controls show the formation of different etheralcohols and secondary products resulting from dehydration, transesterification and dimerization side-reactions. Cleavage reaction of Epoxy-HOSME with a primary amine (butylamine was conducted under pressure, at high temperature (180/200°C. Both transesterification and opening of the oxirane group occur under these conditions. Reaction products are composed of amides formed by transesterification and a mixture of fatty amines/imines obtained by ring opening as established

  6. Formation of Aqueous Suspensions of Fullerenes

    Science.gov (United States)

    Colloidal suspensions of C60, C70 and a derivative of C60, PCBM ([6,6]-Phenyl C61-butyric acid methyl ester) were produced by extended mixing in water. We examined the contribution of background solution chemistry (pH, ionic strength) on the formation kinetics of colloidal suspe...

  7. Immunohistochemical localization of chondroitin sulfate, chondroitin sulfate proteoglycan, heparan sulfate proteoglycan, entactin, and laminin in basement membranes of postnatal developing and adult rat lungs

    DEFF Research Database (Denmark)

    Sannes, P L; Burch, K K; Khosla, J

    1993-01-01

    Histologic preparations of lungs from 1-, 5-, 10-, 18-, and 25-day-old postnatal and adult rats were examined immunohistochemically with antibodies specific against chondroitin sulfate (CS), basement membrane chondroitin sulfate proteoglycan (BM-CSPG), heparan sulfate proteoglycan (HSPG), entacti...

  8. High rates of sulfate reduction in a low-sulfate hot spring microbial mat are driven by a low level of diversity of sulfate-respiring microorganisms

    DEFF Research Database (Denmark)

    Dillon, Jesse G; Fishbain, Susan; Miller, Scott R

    2007-01-01

    The importance of sulfate respiration in the microbial mat found in the low-sulfate thermal outflow of Mushroom Spring in Yellowstone National Park was evaluated using a combination of molecular, microelectrode, and radiotracer studies. Despite very low sulfate concentrations, this mat community...

  9. Crystallization of Chicken Egg White Lysozyme from Assorted Sulfate Salts

    Science.gov (United States)

    Forsythe, Elizabeth L.; Snell, Edward H.; Malone, Christine C.; Pusey, Marc L.

    1999-01-01

    Chicken egg white lysozyme has been found to crystallize from ammonium, sodium, potassium, rubidium, magnesium, and manganese sulfates at acidic and basic pH, with protein concentrations from 60 to 190 mg/ml. Crystals have also been grown at 4 C in the absence of any other added salts using isoionic lysozyme which was titrated to pH 4.6 with dilute sulfuric acid. Four different crystal forms have been obtained, depending upon the temperature, protein concentration, and precipitating salt employed. Crystals grown at 15 C were generally tetragonal, with space group P4(sub 3)2(sub 1)2. Crystallization at 20 C typically resulted in the formation of orthorhombic crystals, space group P2(sub 1)2(sub 1)2(sub 1). The tetragonal reversible reaction orthorhombic transition appeared to be a function of both the temperature and protein concentration, occurring between 15 and 20 C and between 100 and 125 mg/ml protein concentration. Crystallization from 1.2 M magnesium sulfate at pH 7.8 gave a trigonal crystal, space group P3(sub 1)2(sub 1), a = b = 87.4, c = 73.7, gamma = 120 deg, which diffracted to 2.8 A. Crystallization from ammonium sulfate at pH 4.6, generally at lower temperatures, was also found to result in a monoclinic form. space group C2, a = 65.6, b = 95.0, c = 41.2, beta = 119.2 deg. A crystal of approximately 0.2 x 0.2 x 0.5 mm grown from bulk solution diffracted to approximately 3.5 A.

  10. Crystallization of chicken egg white lysozyme from assorted sulfate salts

    Science.gov (United States)

    Forsythe, Elizabeth L.; Snell, Edward H.; Malone, Christine C.; Pusey, Marc L.

    1999-01-01

    Chicken egg white lysozyme has been found to crystallize from ammonium, sodium, potassium, rubidium, magnesium, and manganese sulfates at acidic and basic pH, with protein concentrations from 60 to 190 mg/ml. Crystals have also been grown at 4°C in the absence of any other added salts using isoionic lysozyme which was titrated to pH 4.6 with dilute sulfuric acid. Four different crystal forms have been obtained, depending upon the temperature, protein concentration, and precipitating salt employed. Crystals grown at 15°C were generally tetragonal, with space group P4 32 12. Crystallization at 20°C typically resulted in the formation of orthorhombic crystals, space group P2 12 12 1. The tetragonal ↔ orthorhombic transition appeared to be a function of both the temperature and protein concentration, occurring between 15 and 20°C and between 100 and 125 mg/ml protein concentration. Crystallization from 1.2 M magnesium sulfate at pH 7.8 gave a trigonal crystal, space group P3 12 1, a= b=87.4, c=73.7, γ=120°, which diffracted to 2.8 Å. Crystallization from ammonium sulfate at pH 4.6, generally at lower temperatures, was also found to result in a monoclinic form, space group C2, a=65.6, b=95.0, c=41.2, β=119.2°. A crystal of ˜0.2×0.2×0.5 mm grown from bulk solution diffracted to ˜3.5 Å.

  11. Weathering of Olivine during Interaction of Sulfate Aerosols with Mars Soil under Current Climate Conditions

    Science.gov (United States)

    Niles, P. B.; Golden, D. C.; Michalski, J. R.; Ming, D. W.

    2017-12-01

    Sulfur concentrations in the Mars soils are elevated above 1 wt% in nearly every location visited by landed spacecraft. This observation was first made by the Viking landers, and has been confirmed by subsequent missions. The wide distribution of sulfur in martian soils has been attributed to volcanic degassing, formation of sulfate aerosols, and later incorporation into martian soils during gravitational sedimentation. However, later discoveries of more concentrated sulfur bearing sediments by the Opportunity rover has led some to believe that sulfates may instead be a product of evaporation and aeolian redistribution. One question that has not been addressed is whether the modern surface conditions are too cold for weathering of volcanic materials by sulfate aerosols. We suggest here that mixtures of atmospheric aerosols, ice, and dust have the potential for creating small films of cryo-concentrated acidic solutions that may represent an important unexamined environment for understanding weathering processes on Mars. Laboratory experiments were conducted to simulate weathering of olivine under Mars-like conditions. The weathering rates measured in this study suggest that fine grained olivine on Mars would weather into sulfate minerals in short time periods if they are exposed to H2SO4 aerosols at temperatures at or above -40°C. In this system, the strength of the acidic solution is maximized through eutectic freezing in an environment where the silicate minerals are extremely fine grained and have high surface areas. This provides an ideal environment for olivine weathering despite the very low temperatures. The likelihood of substantial sulfur-rich volcanism on Mars and creation of abundant sulfate aerosols suggests that this process would have been important during formation of martian soils and sediments. Future work modeling sulfur release rates during volcanic eruptions and aerosol distribution over the surface will help understand how well this process

  12. Sulfate reduction and anaerobic methane oxidation in Black Sea sediments

    DEFF Research Database (Denmark)

    Jørgensen, BB; Weber, A.; Zopfi, J.

    2001-01-01

    Beyond the shelf break at ca. 150 m water depth, sulfate reduction is the only important process of organic matter oxidation in Black Sea sediments from the surface down to the sulfate-methane transition at 2-4 m depth. Sulfate reduction rates were measured experimentally with (SO42-)-S-35...... the process was very sluggish with turnover times of methane within the sulfate-methane transition zone of 20 yr or more. (C) 2001 Elsevier Science Ltd. All rights reserved.Beyond the shelf break at ca. 150 m water depth, sulfate reduction is the only important process of organic matter oxidation in Black Sea...... oxidation accounted for 7-11% of the total sulfate reduction in slope and deep-sea sediments. Although this methane-driven sulfate reduction shaped the entire sulfate gradient, it was only equivalent to the sulfate reduction in the uppermost 1.5 cm of surface sediment. Methane oxidation was complete, yet...

  13. Influence of recycled fine aggregates on the resistance of mortars to magnesium sulfate attack

    International Nuclear Information System (INIS)

    Lee, Seung-Tae

    2009-01-01

    The influence of recycled fine aggregates, which had been reclaimed from field-demolished concretes, on the resistance of mortar specimens to magnesium sulfate attack was investigated. Mortar specimens were prepared with recycled fine aggregates at different replacement levels (0%, 25%, 50%, 75% and 100% of natural fine aggregate by mass). The mortar specimens were exposed to 4.24% magnesium sulfate solution for about 1 year at ambient temperature, and regularly monitored for visual appearance, compressive strength loss and expansion. Additionally, in order to identify products of magnesium sulfate attack, mortar samples incorporating 0%, 25% and 100% replacement levels of the recycled fine aggregates were examined by X-ray diffraction (XRD) technique. Experimental results confirmed that the use of recycled fine aggregates up to a maximum 50% replacement level is effective under severe magnesium sulfate environment, irrespective of type of recycled fine aggregates. However, the worse performance was observed in mortar specimens incorporating 100% replacement level. It was found that the water absorption of recycled fine aggregates affected deterioration of mortar specimens, especially at a higher replacement level. XRD results indicated that the main cause of deterioration of the mortar specimens was primarily due to the formation of gypsum and thaumasite by magnesium sulfate attack. In addition, it appeared that the conversion of C-S-H into M-S-H by the attack probably influenced mechanical deterioration of mortar specimens with recycled fine aggregates.

  14. Anaerobic metabolism of nitroaromatic compounds by sulfate-reducing and methanogenic bacteria

    International Nuclear Information System (INIS)

    Boopathy, R.; Kulpa, C.F.

    1994-01-01

    Ecological observations suggest that sulfate-reducing and methanogenic bacteria might metabolize nitroaromatic compounds under anaerobic conditions if appropriate electron donors and electron acceptors are present in the environment, but this ability had not been demonstrated until recently. Most studies on the microbial metabolism of nitroaromatic compounds used aerobic microorganisms. In most cases no mineralization of nitroaromatics occurs, and only superficial modifications of the structures are reported. However, under anaerobic sulfate-reducing conditions, the nitroaromatic compounds reportedly undergo a series of reductions with the formation of amino compounds. For example, trinitrotoluene under sulfate-reducing conditions is reduced to triaminotoluene by the enzyme nitrite reductase, which is commonly found in many Desulfovibrio spp. The removal of ammonia from triaminotoluene is achieved by reductive deamination catalyzed by the enzyme reductive deaminase, with the production of ammonia and toluene. Some sulfate reducers can metabolize toluene to CO 2 . Similar metabolic processes could be applied to other nitroaromatic compounds like nitrobenzene, nitrobenzoic acids, nitrophenols, and aniline. Many methanogenic bacteria can reduce nitroaromatic compounds to amino compounds. In this paper we review the anaerobic metabolic processes of nitroaromatic compounds under sulfate-reducing And methanogenic conditions

  15. Radiographic success of ferric sulfate and formocresol pulpotomies in relation to early exfoliation.

    Science.gov (United States)

    Vargas, Kaaren G; Packham, Brett

    2005-01-01

    The purpose of this retrospective study was to evaluate the radiographic findings with formocresol and ferric sulfate pulpotomies in relation to early tooth loss. Vital pulpotomies with either ferric sulfate or formocresol, performed by faculty members between 1992 and 2002 at The University of Iowa, were evaluated retrospectively. Radiographic criteria were established to assess success or failure of the treated tooth. This was then correlated with time of tooth loss and space management. Eighty-five molars, followed between 6 to 61 months, met the inclusion criteria. Of these, 15 (43%) teeth treated with ferric sulfate, 23 (56%) treated with formocresol, and 5 (55%) treated with a combination of ferric sulfate and formocresol remained free of any radiographic pathology. Overall, 13% of the pulpotomized teeth were prematurely lost due to abscess formation and in need of space management. Regardless of the treatment type, internal root resorption was the most common cause of premature exfoliation. Both ferric sulfate and formocresol pulpotomies can lead to premature exfoliation of primary teeth, with the subsequent need for orthodontic space maintenance. Therefore, radiographic criteria should be taken into consideration when evaluating pulpotomized teeth at recall visits.

  16. Isolation and characterization of a Pseudomonas sp. strain IITR01 capable of degrading α-endosulfan and endosulfan sulfate.

    Science.gov (United States)

    Bajaj, A; Pathak, A; Mudiam, M R; Mayilraj, S; Manickam, N

    2010-12-01

    To isolate bacteria capable of degrading endosulfan (ES) and the more toxic ES sulfate and to characterize their metabolites. A Pseudomonas sp. strain IITR01 capable of degrading α-ES and toxic ES sulfate was isolated using technical-ES through enrichment culture techniques. No growth and no degradation were observed using β-ES. Thin-layer chromatography and gas chromatography-mass spectrum analysis revealed the disappearance of both α-ES and ES sulfate and the formation of hydroxylated products ES diol, ether and lactone. We show here for the first time the formation of aforementioned metabolites in contrast to ES hemisulfate yielded by an Arthrobacter sp. Metabolism of α-ES and endosulfate was also observed using the crude cell extract of IITR01. The molecular mass of protein induced during the degradation of α-ES and sulfate as substrate was found to be approximately 150 kDa as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). We describe characterization of bacterium capable of degrading α-ES and ES sulfate but not β-ES. Genetic investigation suggests that a gene nonhomologous to the reported esd may be present in the strain IITR01. This study describes toxic ES degradation by a Pseudomonas species that may be utilized for the bioremediation of the industrial soils contaminated with ES residues. © 2010 The Authors. Journal of Applied Microbiology © 2010 The Society for Applied Microbiology.

  17. p-Cresyl sulfate and indoxyl sulfate in pediatric patients on chronic dialysis

    Directory of Open Access Journals (Sweden)

    Hye Sun Hyun

    2013-04-01

    Full Text Available &lt;b&gt;Purpose:&lt;/b&gt; Indoxyl sulfate and p- cresyl sulfate are important protein-bound uremic retention solutes whose levels can be partially reduced by renal replacement therapy. These solutes originate from intestinal bacterial protein fermentation and are associated with cardiovascular outcomes and chronic kidney disease progression. The aims of this study were to investigate the levels of indoxyl sulfate and p- cresyl sulfate as well as the effect of probiotics on reducing the levels of uremic toxins in pediatric patients on dialysis. &lt;b&gt;Methods:&lt;/b&gt; We enrolled 20 pediatric patients undergoing chronic dialysis; 16 patients completed the study. The patients underwent a 12-week regimen of VSL#3, a high-concentration probiotic preparation, and the serum levels of indoxyl sulfate and p- cresyl sulfate were measured before treatment and at 4, 8, and 12 weeks after the regimen by using fluorescence liquid chromatography. To assess the normal range of indoxyl sulfate and p- cresyl sulfate we enrolled the 16 children with normal glomerular filtration rate who had visited an outpatient clinic for asymptomatic microscopic hematuria that had been detected by a school screening in August 2011. &lt;b&gt;Results:&lt;/b&gt; The baseline serum levels of indoxyl sulfate and p- cresyl sulfate in the patients on chronic dialysis were significantly higher than those in the children with microscopic hematuria. The baseline serum levels of p- cresyl sulfate in the peritoneal dialysis group were significantly higher than those in the hemodialysis group. There were no significant changes in the levels of these uremic solutes after 12-week VSL#3 treatment in the patients on chronic dialysis. &lt;b&gt;Conclusion:&lt;/b&gt; The levels of the uremic toxins p- cresyl sulfate and indoxyl sulfate are highly elevated in pediatric patients on dialysis, but there was no significant effect by

  18. Sulfated glycopeptide nanostructures for multipotent protein activation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sungsoo S.; Fyrner, Timmy; Chen, Feng; Álvarez, Zaida; Sleep, Eduard; Chun, Danielle S.; Weiner, Joseph A.; Cook, Ralph W.; Freshman, Ryan D.; Schallmo, Michael S.; Katchko, Karina M.; Schneider, Andrew D.; Smith, Justin T.; Yun, Chawon; Singh, Gurmit; Hashmi, Sohaib Z.; McClendon, Mark T.; Yu, Zhilin; Stock, Stuart R.; Hsu, Wellington K.; Hsu, Erin L.; Stupp , Samuel I. (NWU)

    2017-06-19

    Biological systems have evolved to utilize numerous proteins with capacity to bind polysaccharides for the purpose of optimizing their function. A well-known subset of these proteins with binding domains for the highly diverse sulfated polysaccharides are important growth factors involved in biological development and tissue repair. We report here on supramolecular sulfated glycopeptide nanostructures, which display a trisulfated monosaccharide on their surfaces and bind five critical proteins with different polysaccharide-binding domains. Binding does not disrupt the filamentous shape of the nanostructures or their internal β-sheet backbone, but must involve accessible adaptive configurations to interact with such different proteins. The glycopeptide nanostructures amplified signalling of bone morphogenetic protein 2 significantly more than the natural sulfated polysaccharide heparin, and promoted regeneration of bone in the spine with a protein dose that is 100-fold lower than that required in the animal model. These highly bioactive nanostructures may enable many therapies in the future involving proteins.

  19. Physical and microstructural aspects of sulfate attack on ordinary and limestone blended Portland cements

    International Nuclear Information System (INIS)

    Schmidt, Thomas; Lothenbach, Barbara; Romer, Michael; Neuenschwander, Juerg; Scrivener, Karen

    2009-01-01

    The consequences of external sulfate attack were investigated by traditional test methods, i.e. length and mass change, as well as by a newly developed, surface sensitive ultrasonic method, using Leaky Rayleigh waves (1 MHz). The macroscopic changes are discussed and compared with thermodynamic calculations and microstructural findings (SEM/EDS). The results show that the main impact of limestone additions on resistance to sulfate degradation are physical - i.e. addition of a few percent in Portland cement reduces the porosity and increases the resistance of Portland cement systems to sulfate; but higher addition of 25% increase porosity and lower resistance to sulfate. The kinetics of degradation were dramatically affected by the solution concentration (4 or 44 g Na 2 SO 4 /l) and the higher concentration also resulted in the formation of gypsum, which did not occur at the low concentration. However the pattern of cracking was similar in both cases and it appears that gypsum precipitates opportunistically in pre-formed cracks so it is not considered as making a significant contribution to the degradation. At 8 deg. C limited formation of thaumasite occurred in the surface region of the samples made from cement with limestone additions. This thaumasite formation led to loss of cohesion of the paste and loss of material from the surface of the samples. However thaumasite formation was always preceded by expansion and cracking of the samples due to ettringite formation and given the very slow kinetics of thaumasite formation it was probably facilitated by the opening up of the structure due to ettringite induced cracking. The expansion of the samples showed a steady stage, followed by a rapidly accelerating stage, with destruction of the samples. The onset of the rapidly accelerating stage occurred when the thickness of the cracked surface layer reached about 1-1.5 mm-10-15% of the total specimen thickness (10 mm).

  20. PROCESS FOR HYDROGENOLYSIS OF ALPHA-HYDROXY ESTERS OR ACIDS USING A HETEROGENEOUS CATALYST

    DEFF Research Database (Denmark)

    2017-01-01

    The present invention relates to a method for hydrogenolysis of alpha-hydroxy esters or acids, comprising reacting the alpha-hydroxy ester or acid in the presence of a heterogeneous catalyst. The present invention also relates to a method for producing propionic acid ester, and the use of any...... of the methods for the production of propionic acid esters, such as alkyl propionate....

  1. 21 CFR 172.852 - Glyceryl-lacto esters of fatty acids.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Glyceryl-lacto esters of fatty acids. 172.852... HUMAN CONSUMPTION Multipurpose Additives § 172.852 Glyceryl-lacto esters of fatty acids. Glyceryl-lacto esters of fatty acids (the lactic acid esters of mono- and diglycerides) may be safely used in food in...

  2. Chemoenzymatic Synthesis and Chemical Recycling of Poly(ester-urethanes

    Directory of Open Access Journals (Sweden)

    Hiroto Hayashi

    2011-08-01

    Full Text Available Novel poly(ester-urethanes were prepared by a synthetic route using a lipase that avoids the use of hazardous diisocyanate. The urethane linkage was formed by the reaction of phenyl carbonate with amino acids and amino alcohols that produced urethane-containing diacids and hydroxy acids, respectively. The urethane diacid underwent polymerization with polyethylene glycol and a,w-alkanediols and also the urethane-containing hydroxy acid monomer was polymerized by the lipase to produce high-molecular-weight poly(ester-urethanes. The periodic introduction of ester linkages into the polyurethane chain by the lipase-catalyzed polymerization afforded chemically recyclable points. They were readily depolymerized in the presence of lipase into cyclic oligomers, which were readily repolymerized in the presence of the same enzyme. Due to the symmetrical structure of the polymers, poly(ester-urethanes synthesized in this study showed higher Tm, Young’s modulus and tensile strength values.

  3. Space-Qualifiable Cyanate Ester Elastomer, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Cornerstone Research Group, Inc. (CRG) proposes to design and develop a space-qualifiable cyanate ester elastomer for application in self-deployable space structures...

  4. Biocatalytic synthesis and antioxidant capacities of ascorbyl esters ...

    African Journals Online (AJOL)

    ajl yemi

    2011-11-28

    , 2009). Lipases, especially that from Candida antarctica, have been successfully used to catalyze the synthesis of ascorbyl esters in tertiary alcohols, acetone and even in ionic liquids, employing saturated and unsaturated ...

  5. [Exposure to vegetal esters based metal cutting fluids: health effects].

    Science.gov (United States)

    Riva, M M; Bellini, M; Leghissa, P; Gambini, D; Mosconi, G

    2012-01-01

    The aim of our research is to study respiratory and dermatologic diseases (irritative and allergic) in a cohort of workers exposed to vegetal esters based metal cutting fluids of the latest generation. A cohort of 81 workers (mean age 34.5 years, seniority 17.4 years), with mean exposure to vegetal esters based metal cutting fluids of 2.8 years, has been subjected to clinical evaluations. The investigation did not reveal any disease or disorder of the respiratory system, any folluculitis or any allergic contact dermatitis caused by sensitization to vegetal esters based metal cutting fluids. On the contrary we documented 5 cases of irritant contact dermatitis, even if favored by an improper use of protection devices. According to early results, the introduction of vegetal esters based metal cutting fluids seems to reduce the risk to the worker's health. A longitudinal surveillance is still needed to confirm that even in the medium and long-term sensitizations will not occur.

  6. Diterpene esters of aristolochic acids from Aristolochia pubescens.

    Science.gov (United States)

    Nascimento, Isabele R; Lopes, Lucia M X

    2003-08-01

    From the acetone and ethanol extracts of the tubercula of Aristolochia pubescens, two diterpene esters of aristolochic acids were isolated, together with 23 known compounds. The structures of the compounds were determined on the basis of spectroscopic analysis.

  7. Space-Qualifiable Cyanate Ester Elastomer, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — In Phase 1, CRG demonstrated the feasibility of a novel approach to prepare cyanate ester based elastomers. This approach polymerizes in-situ siloxane within a...

  8. Incorporation of Epicatechin Esters into Lignin Enhances Cell Wall Fermentability

    Science.gov (United States)

    Polyphenolic catechin esters are potentially attractive targets for lignin bioengineering because their copolymerization with monolignols could reduce lignin hydrophobicity and cross-linking to polysaccharides, or facilitate delignification by biomass pretreatments. To test this hypothesis, we biomi...

  9. Baker's yeast: production of D- and L-3-hydroxy esters

    DEFF Research Database (Denmark)

    Dahl, Allan Carsten; Madsen, Jørgen Øgaard

    1998-01-01

    Baker's yeast grown under oxygen limited conditions and used in the reduction of 3-oxo esters results in a shift of the stereoselectivity of the yeast towards D-hydroxy esters as compared with ordinary baker's yeast. The highest degree of stereoselectivity was obtained with growing yeast or yeast...... harvested while growing. In contrast, the stereoselectivity was shifted towards L-hydroxy esters when the oxo esters were added slowly to ordinary baker's yeast supplied with gluconolactone as co-substrate. The reduction rate with gluconolactone was increased by active aeration. Ethyl L-(S)-3......-hydroxybutanoate was afforded in >99% ee. Both enantiomers of ethyl 3-hydroxypentanoate, D-(R) in 96% ee and L-(S) in 93% ee, and of ethyl 4-chloro-3-hydroxybutanoate, D-(S) in 98% ee and L-(R) in 94% ee, were obtained. The results demonstrate that the stereoselectivity of baker's yeast can be controlled...

  10. Combustion characteristics of the mustard methyl esters

    International Nuclear Information System (INIS)

    Bannikov, M.G.; Vasilev, I.P.

    2011-01-01

    Mustard Methyl Esters (further bio diesel) and regular diesel fuel were tested in direct injection diesel engine. Analysis of experimental data was supported by an analysis of fuel injection and combustion characteristics. Engine fuelled with bio diesel had increased brake specific fuel consumption, reduced nitrogen oxides emission and smoke opacity, moderate increase in carbon monoxide emission with essentially unchanged unburned hydrocarbons emission. Increase in fuel consumption was attributed to lesser heating value of bio diesel and partially to decreased fuel conversion efficiency. Analysis of combustion characteristics revealed earlier start of injection and shorter ignition delay period of bio diesel. Resulting decrease in maximum rate of heat release and cylinder pressure was the most probable reason for reduced emission of nitrogen oxides. Analysis of combustion characteristics also showed that cetane index determined by ASTM Method D976 is not a proper measure of ignition quality of bio diesel. Conclusion was made on applicability of mustard oil as a source for commercial production of bio diesel in Pakistan. Potentialities of on improving combustion and emissions characteristics of diesel engine by reformulating bio diesel were discussed. (author)

  11. Solid state crystallisation of oligosaccharide ester derivatives

    CERN Document Server

    Wright, E A

    2002-01-01

    An investigation of the solid state properties of oligosaccharide ester derivatives (OEDs) with potential applications in drug delivery has been carried out. The amorphous form of two OEDs, trehalose octa-acetate (TOAC) and 6:6'-di-(beta-tetraacetyl glucuronyl)-hexaacetyl trehalose (TR153), was investigated as a matrix for the sustained release of active ingredients. The matrices showed a tendency to crystallise and so polymorph screens were performed to provide crystalline samples for structural analysis. The crystal structures of TOAC methanolate and TR153 acetonitrile solvate have been determined by single-crystal laboratory X-ray diffraction. TOAC methanolate crystallises in the orthorhombic space group P2 sub 1 2 sub 1 2 sub 1 with a = 15.429(18) A, b = 17.934(19) A and c = 13.518(4) A at 123 K. The structure is isomorphous with the previously reported structure of TOAC monohydrate form II. TR153 acetonitrile solvate crystallises in the monoclinic spacegroup C2 with a = 30:160(6) A, b = 11.878(3) A, c 20...

  12. The effect of supercharging on performance and emission characteristics of C.I. Engine with diesel-ethanol-ester blends

    Directory of Open Access Journals (Sweden)

    Donepudi Jagadish

    2011-01-01

    Full Text Available Biofuels like ethanol, biodiesel, have attracted attention of people worldwide and proved to be the successful fuel alternates to petroleum products. In the present investigation, the effect of supercharging is studied on the performance of a direct injection diesel engine using ethanol diesel blends with palm stearin methyl ester as additive. The performance of the engine is evaluated in terms of brake specific fuel consumption, thermal efficiency, exhaust gas temperature, un-burnt hydrocarbons, carbon monoxide, nitrogen oxide emissions, and smoke opacity. The investigation results showed that the output and torque performance of the engine with supercharging was improved in comparison with naturally aspirated engine. It is observed that the brake thermal efficiency of ethanol diesel blends was higher than that of diesel. With supercharging brake thermal efficiency is further improved. Brake specific fuel consumption of ethanol, ester and diesel blends are lower compared with diesel at full load. Further reduction in brake specific fuel consumption is observed with supercharging. Nitrous oxide formation seems to decrease with ethanol, ester and diesel blends. Hydrocarbons and carbon monoxide emissions are more with ethanol, ester and diesel blends with supercharging slight reduction in those values are observed.

  13. How Well Does BODIPY-Cholesteryl Ester Mimic Unlabeled Cholesteryl Esters in High Density Lipoprotein Particles?

    DEFF Research Database (Denmark)

    Karilainen, Topi; Vuorela, Timo; Vattulainen, Ilpo

    2015-01-01

    We compare the behavior of unlabeled and BODIPY-labeled cholesteryl ester (CE) in high density lipoprotein by atomistic molecular dynamics simulations. We find through replica exchange umbrella sampling and unbiased molecular dynamics simulations that BODIPY labeling has no significant effect...... on the partitioning of CE between HDL and the water phase. However, BODIPY-CE was observed to diffuse more slowly and locate itself closer to the HDL-water interface than CE due to the BODIPY probe that is constrained to the surface region, and because the CE body in BODIPY-CE prefers to align itself away from...

  14. Sources of Sulfate Found in Mounds and Lakes at the Lewis Cliffs Ice Tongue, Transantarctic

    Science.gov (United States)

    Socki, Richard; Sun, Tao; Harvey, Ralph P.; Bish, David L.; Tonui, Eric; Bao, Huiming; Niles, Paul B.

    2012-01-01

    Massive but highly localized Na-sulfate mounds (mirabilite, Na2SO4.10H2O) have been found at the terminal moraine of the Lewis Cliffs Ice Tongue (LCIT), Antarctica. (Sigma)34S and (Sigma)18O values of LCIT mirabilite range from +48.8 to +49.3% (CDT), and -16.6 to -17.1% (V-SMOW), respectively, while (Delta)17O average -0.37% (V-SMOW). LCIT mirabilite mounds are isotopically different from other mirabilite mounds found in coastal regions of Antarctica, which have isotope values close to seawater compositions. (Sigma)18O and (Delta)17O values suggest the incorporation of isotopically light glacial water. Data point to initial sulfate formation in an anoxic water body, either as a stratified anoxic deep lake on the surface, a sub-glacial water reservoir, or a sub-glacial lake. Several surface lakes of varying size are also present within this region of the LCIT, and in some cases are adjacent to the mirabilite mounds. O and D isotope compositions of surface lakes confirm they are derived from a mixture of glacial ice and snow that underwent moderate evaporation. (Sigma)18O and (Sigma)D (V-SMOW) values of snow, ice, and lake water range from -64.2 to -29.7%, and -456.0 to -231.7%, respectively. However, the isotope chemistry of these surface lakes is extremely different from the mounds. Dissolved SO4-2 (Sigma)34S and (Sigma)18O values range from +12.0 to +20.0% and -12.8 to -22.2% (the most negative (Sigma)18O of terrestrial sulfate ever reported), respectively, with sulfate (Delta)17O ranging from +0.93 to 2.24%. Ion chromatography data show that lake water is fresh to brackish in origin, with TDS less than 1500 ppm, and sulfate concentration less than 431 ppm. Isotope and chemical data suggest that these lakes are unlikely the source of the mirabilite mounds. We suggest that lake water sulfate is potentially composed of a mixture of atmospheric sulfate and minor components of sulfate of weathering origin, much like the sulfate in the polar plateau soils of the Mc

  15. On the evaporation of ammonium sulfate solution

    Energy Technology Data Exchange (ETDEWEB)

    Drisdell, Walter S.; Saykally, Richard J.; Cohen, Ronald C.

    2009-07-16

    Aqueous evaporation and condensation kinetics are poorly understood, and uncertainties in their rates affect predictions of cloud behavior and therefore climate. We measured the cooling rate of 3 M ammonium sulfate droplets undergoing free evaporation via Raman thermometry. Analysis of the measurements yields a value of 0.58 {+-} 0.05 for the evaporation coefficient, identical to that previously determined for pure water. These results imply that subsaturated aqueous ammonium sulfate, which is the most abundant inorganic component of atmospheric aerosol, does not affect the vapor-liquid exchange mechanism for cloud droplets, despite reducing the saturation vapor pressure of water significantly.

  16. On the evaporation of ammonium sulfate solution

    International Nuclear Information System (INIS)

    Drisdell, Walter S.; Saykally, Richard J.; Cohen, Ronald C.

    2009-01-01

    Aqueous evaporation and condensation kinetics are poorly understood, and uncertainties in their rates affect predictions of cloud behavior and therefore climate. We measured the cooling rate of 3 M ammonium sulfate droplets undergoing free evaporation via Raman thermometry. Analysis of the measurements yields a value of 0.58 ± 0.05 for the evaporation coefficient, identical to that previously determined for pure water. These results imply that subsaturated aqueous ammonium sulfate, which is the most abundant inorganic component of atmospheric aerosol, does not affect the vapor-liquid exchange mechanism for cloud droplets, despite reducing the saturation vapor pressure of water significantly.

  17. Methods of refining and producing dibasic esters and acids from natural oil feedstocks

    Energy Technology Data Exchange (ETDEWEB)

    Snead, Thomas E.; Cohen, Steven A.; Gildon, Demond L.

    2016-03-15

    Methods are provided for refining natural oil feedstocks and producing dibasic esters and/or dibasic acids. The methods comprise reacting a terminal olefin with an internal olefin in the presence of a metathesis catalyst to form a dibasic ester and/or dibasic acid. In certain embodiments, the olefin esters are formed by reacting the feedstock in the presence of a metathesis catalyst under conditions sufficient to form a metathesized product comprising olefins and esters, separating the olefins from the esters in the metathesized product, and transesterifying the esters in the presence of an alcohol to form a transesterified product having olefin esters.

  18. Methods of refining and producing dibasic esters and acids from natural oil feedstocks

    Energy Technology Data Exchange (ETDEWEB)

    Snead, Thomas E; Cohen, Steven A; Gildon, Demond L

    2015-04-07

    Methods are provided for refining natural oil feedstocks and producing dibasic esters and/or dibasic acids. The methods comprise reacting a terminal olefin with an internal olefin in the presence of a metathesis catalyst to form a dibasic ester and/or dibasic acid. In certain embodiments, the olefin esters are formed by reacting the feedstock in the presence of a metathesis catalyst under conditions sufficient to form a metathesized product comprising olefins and esters, separating the olefins from the esters in the metathesized product, and transesterifying the esters in the presence of an alcohol to form a transesterified product having olefin esters.

  19. Natural fiber reinforced composites with moringa and vnyl ester matrix

    OpenAIRE

    Sundara, Babu Jagannathan

    2015-01-01

    In this research work an attempt is carried out for producing a Natural Plant Based fiber Reinforced Composites using the Moringa Resins and Vinyl Ester by utilizing the wastage of natural plant based fiber as Reinforcement material and Matrix material as Natural Resin and Vinyl Ester. The objective of the work is Utilization of Natural Plant Based Bio- degardable wastage into an alternative materials in the industrial applications by analyzing, Various Manufacturing and testing. Initially th...

  20. RAFT Polymerization of Vinyl Esters: Synthesis and Applications

    OpenAIRE

    Simon Harrisson; Xuan Liu; Jean-Noël Ollagnier; Olivier Coutelier; Jean-Daniel Marty; Mathias Destarac

    2014-01-01

    This article is the first comprehensive review on the study and use of vinyl ester monomers in reversible addition fragmentation chain transfer (RAFT) polymerization. It covers all the synthetic aspects associated with the definition of precision polymers comprising poly(vinyl ester) building blocks, such as the choice of RAFT agent and reaction conditions in order to progress from simple to complex macromolecular architectures. Although vinyl acetate was by far the most studied monomer of th...

  1. Measurement of chemical leaching potential of sulfate from landfill disposed sulfate containing wastes.

    Science.gov (United States)

    Sun, Wenjie; Barlaz, Morton A

    2015-02-01

    A number of sulfate-containing wastes are disposed in municipal solid wastes (MSW) landfills including residues from coal, wood, and MSW combustion, and construction and demolition (C&D) waste. Under anaerobic conditions that dominate landfills, the sulfate can be reduced to hydrogen sulfide which is problematic for several reasons including its low odor threshold, toxicity, and corrosive nature. The overall objective of this study was to evaluate existing protocols for the quantification of total leachable sulfate from solid samples and to compare their effectiveness and efficiency with a new protocol described in this study. Methods compared include two existing acid extraction protocols commonly used in the U.S., a pH neutral protocol that requires multiple changes of the leaching solution, and a new acid extraction method. The new acid extraction method was shown to be simple and effective to measure the leaching potential of sulfate from a range of landfill disposed sulfate-containing wastes. However, the acid extraction methods do not distinguish between sulfate and other forms of sulfur and are thus most useful when sulfate is the only form of sulfur present. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Isolation of endosulfan sulfate-degrading Rhodococcus koreensis strain S1-1 from endosulfan contaminated soil and identification of a novel metabolite, endosulfan diol monosulfate

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Koji; Kawashima, Fujimasa [Department of Applied Biology and Chemistry, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo, 156-8502 (Japan); Organochemicals Division, National Institute for Agro-Environmental Sciences, 3-1-3 Kannondai, Tsukuba, Ibaraki, 305-8604 (Japan); Takagi, Kazuhiro, E-mail: ktakagi@affrc.go.jp [Department of Applied Biology and Chemistry, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo, 156-8502 (Japan); Organochemicals Division, National Institute for Agro-Environmental Sciences, 3-1-3 Kannondai, Tsukuba, Ibaraki, 305-8604 (Japan); Kataoka, Ryota [Department of Environmental Science, University of Yamanashi, 41-4-37 Takeda, Kofu, Yamanashi (Japan); Kotake, Masaaki [Graduate School of Agricultural Science, Tohoku University, Aoba-ku, Sendai 981-8555 (Japan); Kiyota, Hiromasa [Graduate School of Environmental & Life Science, Okayama University, 1-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530 (Japan); Yamazaki, Kenichi [Organochemicals Division, National Institute for Agro-Environmental Sciences, 3-1-3 Kannondai, Tsukuba, Ibaraki, 305-8604 (Japan); Sakakibara, Futa [Organochemicals Division, National Institute for Agro-Environmental Sciences, 3-1-3 Kannondai, Tsukuba, Ibaraki, 305-8604 (Japan); The Japan Society for the Promotion of Science(JSPS), 1-8 Chiyoda-ku, Tokyo (Japan); Okada, Sanae [Department of Applied Biology and Chemistry, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo, 156-8502 (Japan)

    2016-05-13

    An aerobic endosulfan sulfate-degrading bacterium, Rhodococcus koreensis strain S1-1, was isolated from soil to which endosulfan had been applied annually for more than 10 years until 2008. The strain isolated in this work reduced the concentration of endosulfan sulfate (2) from 12.25 μM to 2.11 μM during 14 d at 30 °C. Using ultra performance liquid chromatography-electrospray ionization-mass spectroscopy (UPLC-ESI-MS), a new highly water-soluble metabolite possessing six chlorine atoms was found to be endosulfan diol monosulfate (6), derived from 2 by hydrolysis of the cyclic sulfate ester ring. The structure of 6 was elucidated by chemical synthesis of the candidate derivatives and by HR-MS and UPLC-MS analyses. Therefore, it was suggested that the strain S1-1 has a new metabolic pathway of 2. In addition, 6 was expected to be less toxic among the metabolites of 1 because of its higher water-solubility. -- Highlights: •A novel endosulfan sulfate-degrading bacterium was isolated and named strain S1-1. •Strain S1-1 degraded endosulfan sulfate into a novel metabolite endosulfan diol monosulfate. •Endosulfan diol monosulfate showed higher polarity than other known metabolites of endosulfan. •We proposed the plausible metabolic pathway of endosulfan in terms of organic chemistry.

  3. Methods of refining and producing isomerized fatty acid esters and fatty acids from natural oil feedstocks

    Energy Technology Data Exchange (ETDEWEB)

    Snead, Thomas E.; Cohen, Steven A.; Gildon, Demond L.; Beltran, Leslie V.; Kunz, Linda A.; Pals, Tessa M.; Quinn, Jordan R; Behrends, Jr., Raymond T.; Bernhardt, Randal J.

    2016-07-05

    Methods are provided for refining natural oil feedstocks and producing isomerized esters and acids. The methods comprise providing a C4-C18 unsaturated fatty ester or acid, and isomerizing the fatty acid ester or acid in the presence of heat or an isomerization catalyst to form an isomerized fatty ester or acid. In some embodiments, the methods comprise forming a dibasic ester or dibasic acid prior to the isomerizing step. In certain embodiments, the methods further comprise hydrolyzing the dibasic ester to form a dibasic acid. In certain embodiments, the olefin is formed by reacting the feedstock in the presence of a metathesis catalyst under conditions sufficient to form a metathesized product comprising olefins and esters, separating the olefins from the esters in the metathesized product, and transesterifying the esters in the presence of an alcohol to form a transesterified product having unsaturated esters.

  4. Green Synthesis of Barium Sulfate Particles Using Plant Extracts

    Directory of Open Access Journals (Sweden)

    Chen Long

    2016-01-01

    Full Text Available The biological molecules in the extracts of four fruits or vegetables: kiwifruit, oranges, tomato and carrot, were used as templates to synthesize barium sulfate (BaSO4 particles. The products were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray power diffractometry. The results showed that, leaf-shaped barite BaSO4 crystals with toothed edge were obtained with kiwifruit extracts; thorn spherical barium sulfate crystals with diameter of 2-4 micrometers were produced with tomato extracts; rod-like or quasi-spherical BaSO4 crystals with size of several hundred nanometers to several micrometers were gained with orange extracts; while quasi-spherical BaSO4 nano-crystals were obtained with carrot extracts. The formation mechanism of BaSO4 is also discussed, showing that the proteins, carbohydrates, vitamins and organic acids in above four kinds of fruits or vegetables may provide nucleation sites, controlling the growth of BaSO4 crystals with different morphologies.

  5. Constituents of Mediterranean Spices Counteracting Vascular Smooth Muscle Cell Proliferation: Identification and Characterization of Rosmarinic Acid Methyl Ester as a Novel Inhibitor

    Czech Academy of Sciences Publication Activity Database

    Liu, R.; Heiss, E.H.; Waltenberger, B.; Blažević, T.; Schachner, B.; Jiang, B.; Kryštof, Vladimír; Liu, W.; Schwaiger, S.; Peña-Rodríguez, L. M.; Breuss, J.; Stuppner, H.; Dirsch, V.M.; Atanasov, A. G.

    2018-01-01

    Roč. 62, č. 7 (2018), č. článku 1700860. ISSN 1613-4125 Institutional support: RVO:61389030 Keywords : Mediterranean spices * neointima formation * rosmarinic acid * rosmarinic acid methyl ester * vascular smooth muscle cell s Subject RIV: CE - Biochemistry OBOR OECD: Biochemical research methods Impact factor: 4.323, year: 2016

  6. Heterogeneous ice nucleation on phase-separated organic-sulfate particles: effect of liquid vs. glassy coatings

    Directory of Open Access Journals (Sweden)

    G. P. Schill

    2013-05-01

    Full Text Available Atmospheric ice nucleation on aerosol particles relevant to cirrus clouds remains one of the least understood processes in the atmosphere. Upper tropospheric aerosols as well as sub-visible cirrus residues are known to be enhanced in both sulfates and organics. The hygroscopic phase transitions of organic-sulfate particles can have an impact on both the cirrus cloud formation mechanism and resulting cloud microphysical properties. In addition to deliquescence and efflorescence, organic-sulfate particles are known to undergo another phase transition known as liquid–liquid phase separation. The ice nucleation properties of particles that have undergone liquid–liquid phase separation are unknown. Here, Raman microscopy coupled with an environmental cell was used to study the low temperature deliquescence, efflorescence, and liquid–liquid phase separation behavior of 2 : 1 mixtures of organic polyols (1,2,6-hexanetriol and 1 : 1 1,2,6-hexanetriol + 2,2,6,6-tetrakis(hydroxymethylcyclohexanol and ammonium sulfate from 240–265 K. Further, the ice nucleation efficiency of these organic-sulfate systems after liquid–liquid phase separation and efflorescence was investigated from 210–235 K. Raman mapping and volume-geometry analysis indicate that these particles contain solid ammonium sulfate cores fully engulfed in organic shells. For the ice nucleation experiments, we find that if the organic coatings are liquid, water vapor diffuses through the shell and ice nucleates on the ammonium sulfate core. In this case, the coatings minimally affect the ice nucleation efficiency of ammonium sulfate. In contrast, if the coatings become semi-solid or glassy, ice instead nucleates on the organic shell. Consistent with recent findings that glasses can be efficient ice nuclei, the phase-separated particles are nearly as efficient at ice nucleation as pure crystalline ammonium sulfate.

  7. Heterogeneous ice nucleation on phase-separated organic-sulfate particles: effect of liquid vs. glassy coatings

    Science.gov (United States)

    Schill, G. P.; Tolbert, M. A.

    2013-05-01

    Atmospheric ice nucleation on aerosol particles relevant to cirrus clouds remains one of the least understood processes in the atmosphere. Upper tropospheric aerosols as well as sub-visible cirrus residues are known to be enhanced in both sulfates and organics. The hygroscopic phase transitions of organic-sulfate particles can have an impact on both the cirrus cloud formation mechanism and resulting cloud microphysical properties. In addition to deliquescence and efflorescence, organic-sulfate particles are known to undergo another phase transition known as liquid-liquid phase separation. The ice nucleation properties of particles that have undergone liquid-liquid phase separation are unknown. Here, Raman microscopy coupled with an environmental cell was used to study the low temperature deliquescence, efflorescence, and liquid-liquid phase separation behavior of 2 : 1 mixtures of organic polyols (1,2,6-hexanetriol and 1 : 1 1,2,6-hexanetriol + 2,2,6,6-tetrakis(hydroxymethyl)cyclohexanol) and ammonium sulfate from 240-265 K. Further, the ice nucleation efficiency of these organic-sulfate systems after liquid-liquid phase separation and efflorescence was investigated from 210-235 K. Raman mapping and volume-geometry analysis indicate that these particles contain solid ammonium sulfate cores fully engulfed in organic shells. For the ice nucleation experiments, we find that if the organic coatings are liquid, water vapor diffuses through the shell and ice nucleates on the ammonium sulfate core. In this case, the coatings minimally affect the ice nucleation efficiency of ammonium sulfate. In contrast, if the coatings become semi-solid or glassy, ice instead nucleates on the organic shell. Consistent with recent findings that glasses can be efficient ice nuclei, the phase-separated particles are nearly as efficient at ice nucleation as pure crystalline ammonium sulfate.

  8. Ester Tuiksoo võitleb viina puhtuse eest / Ester Tuiksoo ; interv. Silja Lättemäe

    Index Scriptorium Estoniae

    Tuiksoo, Ester, 1965-

    2006-01-01

    Põllumajandusminister Ester Tuiksoo lubab Euroopa Liidu piiritusjookide määruse eelnõu arutusel kaitsta seisukohta, et viinaks tuleb pidada üksnes teraviljast või kartulist valmistatud piiritusjooki

  9. Efficient production of the Nylon 12 monomer ω-aminododecanoic acid methyl ester from renewable dodecanoic acid methyl ester with engineered Escherichia coli.

    Science.gov (United States)

    Ladkau, Nadine; Assmann, Miriam; Schrewe, Manfred; Julsing, Mattijs K; Schmid, Andreas; Bühler, Bruno

    2016-07-01

    The expansion of microbial substrate and product scopes will be an important brick promoting future bioeconomy. In this study, an orthogonal pathway running in parallel to native metabolism and converting renewable dodecanoic acid methyl ester (DAME) via terminal alcohol and aldehyde to 12-aminododecanoic acid methyl ester (ADAME), a building block for the high-performance polymer Nylon 12, was engineered in Escherichia coli and optimized regarding substrate uptake, substrate requirements, host strain choice, flux, and product yield. Efficient DAME uptake was achieved by means of the hydrophobic outer membrane porin AlkL increasing maximum oxygenation and transamination activities 8.3 and 7.6-fold, respectively. An optimized coupling to the pyruvate node via a heterologous alanine dehydrogenase enabled efficient intracellular L-alanine supply, a prerequisite for self-sufficient whole-cell transaminase catalysis. Finally, the introduction of a respiratory chain-linked alcohol dehydrogenase enabled an increase in pathway flux, the minimization of undesired overoxidation to the respective carboxylic acid, and thus the efficient formation of ADAME as main product. The completely synthetic orthogonal pathway presented in this study sets the stage for Nylon 12 production from renewables. Its effective operation achieved via fine tuning the connectivity to native cell functionalities emphasizes the potential of this concept to expand microbial substrate and product scopes. Copyright © 2016 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  10. ESTIMATION OF HYDROLYSIS RATE CONSTANTS OF CARBOXYLIC ACID ESTER AND PHOSPHATE ESTER COMPOUNDS IN AQUEOUS SYSTEMS FROM MOLECULAR STRUCTURE BY SPARC

    Science.gov (United States)

    SPARC (SPARC Performs Automated Reasoning in Chemistry) chemical reactivity models were extended to calculate hydrolysis rate constants for carboxylic acid ester and phosphate ester compounds in aqueous non- aqueous and systems strictly from molecular structure. The energy diffe...

  11. Side-chain crystallization in alkyl-substituted cellulose esters and hydroxypropyl cellulose esters.

    Science.gov (United States)

    Chen, Xi; Zheng, Nan; Wang, Qiao; Liu, Lingzhi; Men, Yongfeng

    2017-04-15

    The differences in side chain crystallization behavior between cellulose esters (CEs) and hydroxypropyl cellulose esters (HPCEs) were systematically investigated by a combination of differential scanning calorimetry (DSC) and small and wide-angle X-ray scattering techniques. DSC investigation indicated that under the same side chain length, the fusion enthalpy and the number of crystallized CH 2 of CEs were smaller than HPCEs. At the same time, their d-spacing and molecular arrangements were also different from each other. For the CEs, the side chains are perpendicular to the main chain, while the side chains most probably tend to tilt to main chain in the HPCEs as was evidenced by X-ray scattering results. The phenomenon can be understood as a consequence of different flexibility of attachment bridges in both kinds of side chain polymers and the steric hindrance of methyl group in the hydroxypropyl group in HPCEs. In addition, the added hydroxypropyl substituents make the side chain length increasing. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Phosphate and sulfate-phosphate mineralization in sillimanite-bearing rocks at the Kyakhta deposit, western Transbaikal region

    Science.gov (United States)

    Izbrodin, I. A.; Ripp, G. S.; Karmanov, N. S.

    2009-12-01

    The phosphate and sulfate-phosphate minerals in the sillimanite-bearing rocks of the Kyakhta deposit are considered. The mineral assemblages of the high-Al rocks were formed during prograde and retrograde stages of metamorphism. The first stage is characterized by the formation of sillimanite, corundum, muscovite, quartz, rutile, titanohematite, magnetite, feldspar, biotite, lazulite, and wagnerite. The muscovite composition showed that sillimanite paragenesis was formed at temperatures above 510-600°C. According to oxygen isotope thermometry, the minimum metamorphic temperature for quartz and titanohematite is 690°C. Andalusite, diaspore, quartz, pyrophyllite, muscovite, and a wide range of phosphates and sulfate-phosphates crystallized during the retrograde stage. The decrease in temperature and increase in the water content led to the following sequence of mineral formation: Mg-Fe-Al-Ca-REE-rich phosphates (lazulite, scorzalite, augelite, apatite, and monazite) → Ca-Sr sulfate-phosphates (woodhouseite and svanbergite) → sulfate (barite) → Sr-Ca-Ba aluminophosphates (goyazite, crandallite, and gorceixite). The chemical compositions of phosphates and sulfate-phosphates minerals and their formation conditions are discussed.

  13. Secondary organic aerosol (SOA) derived from isoprene epoxydiols: Insights into formation, aging and distribution over the continental US from the DC3 and SEAC4RS campaigns

    Science.gov (United States)

    Campuzano Jost, P.; Palm, B. B.; Day, D. A.; Hu, W.; Ortega, A. M.; Jimenez, J. L.; Liao, J.; Froyd, K. D.; Pollack, I. B.; Peischl, J.; Ryerson, T. B.; St Clair, J. M.; Crounse, J.; Wennberg, P. O.; Mikoviny, T.; Wisthaler, A.; Ziemba, L. D.; Anderson, B. E.

    2014-12-01

    Isoprene-derived SOA formation has been studied extensively in the laboratory. However, it is still unclear to what extent isoprene contributes to the overall SOA burden over the southeastern US, an area with both strong isoprene emissions as well as large discrepancies between modeled and observed aerosol optical depth. For the low-NO isoprene oxidation pathway, the key gas-phase intermediate is believed to be isoprene epoxide (IEPOX), which can be incorporated into the aerosol phase by either sulfate ester formation (IEPOX sulfate) or direct hydrolysis. As first suggested by Robinson et al, the SOA formed by this mechanism (IEPOX-SOA) has a characteristic fragmentation pattern when analyzed by an Aerodyne Aerosol Mass Spectrometer (AMS) with enhanced relative abundances of the C5H6O+ ion (fC5H6O). Based on data from previous ground campaigns and chamber studies, we have developed a empirical method to quantify IEPOX-SOA and have applied it to the data from the DC3 and SEAC4RS aircraft campaigns that sampled the SE US during the Spring of 2012 and the Summer of 2013. We used Positive Matrix Factorization (PMF) to extract IEPOX-SOA factors that show good correlation with inside or downwind of high isoprene emitting areas and in general agree well with the IEPOX-SOA mass predicted by the empirical expression. According to this analysis, the empirical method performs well regardless of (at times very strong) BBOA or urban OA influences. On average 17% of SOA in the SE US boundary layer was IEPOX-SOA. Overall, the highest concentrations of IEPOX-SOA were typically found around 1-2 km AGL, several hours downwind of the isoprene source areas with high gas-phase IEPOX present. IEPOX-SOA was also detected up to altitudes of 6 km, with a clear trend towards more aged aerosol at altitude, likely a combination of chemical aging and physical airmass mixing. The unique instrument package aboard the NASA-DC8 allows us to examine the influence of multiple factors (aerosol

  14. Properties of aqueous dispersion of chitosan and chondroitin sulfate complex derived from aquatic organisms

    Directory of Open Access Journals (Sweden)

    Novikov V. Yu.

    2016-09-01

    Full Text Available Investigation of production of chondroitin sulfate, chitosan and polyelectrolyte complexes based on them received from the local marine raw materials is relevant from the point of view of developing a comprehensive waste-free technology for natural raw materials processing. The objects of study are chitosan derived from the shell of the Kamchatka crab Paralithodes camtschaticus and chondroitin sulfate derived from cartilage of salmon Salmon salar. To determine the surface tension of polyelectrolyte complex solutions and dispersions the Wilhelmy method has been used, the effective radius of particle dispersion has been calculated by light scattering, measurements of effective viscosity have been carried out under shear deformation. The conditions of formation, surface and rheological properties of the chitosan and chondroitin sulfate complex extracted from aquatic organisms in the Barents Sea have been studied. Obtaining conditions and molar ratios of these polyelectrolytes in which the aqueous dispersion of the complex remains stable for a long time have been established. It has been found that by addition of chondroitin sulfate solution to chitosan solution in molar ratios of 1 : 3; 1 : 6 the dispersion of the polyelectrolyte complex stable for 2 to 3 days has been formed. The polyelectrolyte complex dispersions behave as non-Newtonian pseudoplastic liquid. When the molar ratio of the mixed solution is 1 : 1 (regardless of the sequence of mixing suspension of the polyelectrolyte complex has been formed, then there is precipitation. Equilibrium surface tension of the aqueous dispersion of the polyelectrolyte complex is higher than that of solutions of chondroitin sulfate and chitosan. The effective radius of particles in the complex dispersion has been determined. The effective radius of the particles in the complex dispersion depends on the molar ratio of chondroitin sulfate : chitosan. A qualitative scheme of formation of polyelectrolyte

  15. Extraction and Liquid Chromatography-Tandem Mass Spectrometry Detection of 3-Monochloropropanediol Esters and Glycidyl Esters in Infant Formula.

    Science.gov (United States)

    Leigh, Jessica K; MacMahon, Shaun

    2016-12-14

    A method was developed for the extraction of fatty acid esters of 3-chloro-1,2-propanediol (3-MCPD) and glycidol from infant formula, followed by quantitative analysis of the extracts using liquid chromatography-tandem mass spectrometry (LC-MS/MS). These process-induced chemical contaminants are found in refined vegetable oils, and studies have shown that they are potentially carcinogenic and/or genotoxic, making their presence in edible oils (and processed foods containing these oils) a potential health risk. The extraction procedure involves a liquid-liquid extraction, where powdered infant formula is dissolved in water and extracted with ethyl acetate. Following shaking, centrifugation, and drying of the organic phase, the resulting fat extract is cleaned-up using solid-phase extraction and analyzed by LC-MS/MS. Method performance was confirmed by verifying the percent recovery of each 3-MCPD and glycidyl ester in a homemade powdered infant formula reference material. Average ester recoveries in the reference material ranged from 84.9 to 109.0% (0.6-9.5% RSD). The method was also validated by fortifying three varieties of commercial infant formulas with a 3-MCPD and glycidyl ester solution. Average recoveries of the esters across all concentrations and varieties of infant formula ranged from 88.7 to 107.5% (1.0-9.5% RSD). Based on the validation results, this method is suitable for producing 3-MCPD and glycidyl ester occurrence data in all commercially available varieties of infant formula.

  16. Studies on novel interpenetrating networks of urethane modified poly(ester-amide and vinyl ester of bisphenol-C

    Directory of Open Access Journals (Sweden)

    Pragnesh N. Dave

    2016-05-01

    Full Text Available Bisphthalamic acids were prepared by reaction of maleic anhydride and aromatic diamines. Novel poly(ester-amides (PEAs were prepared by reaction of DGEBF with bisphthalamic acids. Acrylation of PEAs was carried out using acryloyl chloride; products are called acrylated poly(ester-amides (APEAs. Epoxy resin based unsaturated poly(ester-amide resins (UPEAs can be prepared by many methods but here these were prepared by reported method. These UPEAs were then treated with acryloyl chloride to afford acrylated UPEAs resin (i.e. AUPEAs. Interpenetrating networks of equal proportional urethane modified poly(ester-amide and acrylated poly(ester-amide and vinyl ester of biaphenol c (VE resin were prepared. Urethane modified APEAs and AUPEAs were characterized by elemental analysis, molecular weight was determined by vapor pressure osmometer and by IR spectral study and by thermogravimetry. Based on DSC data in situ glass reinforced composites of the resultant blends have been prepared and characterized for mechanical, electrical and chemical properties. Unreinforced blends were characterized by thermogravimetry (TGA.

  17. Synthesis and Characterization of Nanostructured Sulfated Zirconias

    Czech Academy of Sciences Publication Activity Database

    Lutecki, M.; Šolcová, Olga; Werner, S.; Breitkopf, C.

    2010-01-01

    Roč. 53, č. 1 (2010), s. 13-20 ISSN 0928-0707 Grant - others:DFG(DE) BR2068/2-1; DFG(DE) BR2068/2-2 Institutional research plan: CEZ:AV0Z40720504 Keywords : sulfated zirconia * template assisted synthesis * porous materials Subject RIV: CA - Inorganic Chemistry Impact factor: 1.525, year: 2010

  18. 21 CFR 558.364 - Neomycin sulfate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Neomycin sulfate. 558.364 Section 558.364 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... days. Amount consumed will vary depending on animal's consumption and weight. If symptoms persist after...

  19. Mechanisms and Effectivity of Sulfate Reducing Bioreactors ...

    Science.gov (United States)

    Mining-influenced water (MIW) is the main environmental challenges associated with the mining industry. Passive MIW remediation can be achieved through microbial activity in sulfate-reducing bioreactors (SRBRs), but their actual removal rates depend on different factors, one of which is the substrate composition. Chitinous materials have demonstrated high metal removal rates, particularly for the two recalcitrant MIW contaminants Zn and Mn, but their removal mechanisms need further study. We studied Cd, Fe, Zn, and Mn removal in bioactive and abiotic SRBRs to elucidate the metal removal mechanisms and the differences in metal and sulfate removal rates using a chitinous material as substrate. We found that sulfate-reducing bacteria are effective in increasing metal and sulfate removal rates and duration of operation in SRBRs, and that the main mechanism involved was metal precipitation as sulfides. The solid residues provided evidence of the presence of sulfides in the bioactive column, more specifically ZnS, according to XPS analysis. The feasibility of passive treatments with a chitinous substrate could be an important option for MIW remediation. Mining influenced water (MIW) remediation is still one of the top priorities for the agency because it addresses the most important environmental problem associated with the mining industry and that affects thousands of communities in the U.S. and worldwide. In this paper, the MIW bioremediation mechanisms are studied

  20. Determination of boron spectrophotometry in thorium sulfate

    International Nuclear Information System (INIS)

    Federgrun, L.; Abrao, A.

    1976-01-01

    A procedure for the determination of microquantities of boron in nuclear grade thorium sulfate is described. The method is based on the extraction of BF - 4 ion associated to monomethylthionine (MMT) in 1,2 - dichloroethane. The extraction of the colored BF - 4 -MMT complex does not allow the presence of sulfuric and phosphoric acids; other anions interfere seriously. This fact makes the dissolution of the thorium sulfate impracticable, since it is insoluble in both acids. On the other hand, the quantitative separation of thorium is mandatory, to avoid the precipitation of ThF 4 . To overcome this difficulty, the thorium sulfate is dissolved using a strong cationic ion exchanger, Th 4+ being totally retained into the resin. Boron is then analysed in the effluent. The procedure allows the determination of 0.2 to 10.0 microgramas of B, with a maximum error of 10%. Thorium sulfate samples with contents of 0.2 to 2.0μg B/gTh have being analysed [pt

  1. Sulfate-reducing bacteria in anaerobic bioreactors

    NARCIS (Netherlands)

    Oude Elferink, S.J.W.H.

    1998-01-01

    The treatment of industrial wastewaters containing high amounts of easily degradable organic compounds in anaerobic bioreactors is a well-established process. Similarly, wastewaters which in addition to organic compounds also contain sulfate can be treated in this way. For a long time, the

  2. Treating poultry litter with aluminum sulfate (alum)

    Science.gov (United States)

    This is a USDA/ARS factsheet on how to treat poultry litter with aluminum sulfate (alum) to reduce ammonia emissions. Over half of the nitrogen excreted from chickens is lost to the atmosphere as ammonia before the manure is removed from the poultry houses. Research has shown that additions of alu...

  3. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS ...

    African Journals Online (AJOL)

    Four strains of eri, Samia cynthia ricini Lepidoptera: Saturniidae that can be identified morphologically and maintained at North East Institute of Science and Technology, Jorhat were characterized based on their protein profile by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and DNA by random ...

  4. METABOLISM OF SULFATE-REDUCING PROKARYOTES

    NARCIS (Netherlands)

    HANSEN, TA

    1994-01-01

    Dissimilatory sulfate reduction is carried out by a heterogeneous group of bacteria and archaea that occur in environments with temperatures up to 105 degrees C. As a group together they have the capacity to metabolize a wide variety of compounds ranging from hydrogen via typical organic

  5. Sorption of organophosphate esters by carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Wei; Yan, Li [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Duan, Jinming [School of Environmental and Municipal Engineering, Xi’an University of Architecture and Technology, Xi’an 710055 (China); Jing, Chuanyong, E-mail: cyjing@rcees.ac.cn [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China)

    2014-05-01

    Graphical abstract: The interfacial interactions between the OPE molecules and CNTs. - Highlights: • Oxygen-containing groups on CNTs change the sorption property for OPEs. • Molecular configuration of OPEs has insignificant impact on their sorption. • Hydrophobic, π–π EDA and Brønsted acid–base interaction occurred between the CNTs and OPEs. - Abstract: Insights from the molecular-level mechanism of sorption of organophosphate esters (OPEs) on carbon nanotubes (CNTs) can further our understanding of the fate and transport of OPEs in the environment. The motivation for our study was to explore the sorption process of OPEs on multi-walled CNTs (MWCNTs), single-walled CNTs (SWCNTs) and their oxidized counterparts (O-MWCNTs and O-SWCNTs), and its molecular mechanism over a wide concentration range. The sorption isotherm results revealed that the hydrophobicity of OPEs dominated their affinities on a given CNT and the π–π electron donor–acceptor (EDA) interaction also played an important role in the sorption of aromatic OPEs. This π–π EDA interaction, verified with Raman and FT-IR spectroscopy, could restrict the radial vibration of SWCNTs and affect the deformation vibration γ(CH) bands of OPE molecules. The OPE surface coverage on CNTs, estimated using the nonlinear Dubinin–Ashtakhov model, indicated that the oxygen-containing functional groups on CNTs could interact with water molecules by H-bonding, resulting in a decrease in effective sorption sites. In addition, FTIR analysis also confirmed the occurrence of Brønsted acid–base interactions between OPEs and surface OH groups of SWCNTs. Our results should provide mechanistic insights into the sorption mechanism of OPE contaminants on CNTs.

  6. [Spatial orientation interaction mechanism between chondroitin sulfate and azure A].

    Science.gov (United States)

    Cao, Wen-gen; Chen, Lei; Jiao, Qing-cai; Ding, Li-hua

    2003-06-01

    The spatial orientation interaction mechanism of chondroitin sulfate (CS) and azure A (AA) was studied by spectrometry. The maximum binding number (N = 151) and the binding equilibrium constant (K = 5. 24 x 10(4)) were obtained. The molecular binding model of the interaction between AA and CS was established. The influence of the molar ratio of AA/CS, ethanol, hydroxypropyl-beta-cyclodextrin, triton X-100 and NaCl on the spectra of AA-CS complex was investigated. We conclude that the color change of complex depends on not only the electrostatic interaction between AA and CS but also the density of AA binding on CS. And the formation of the absorption peak at 550 nm and the color change of complex result mainly from the hydrophobic interaction between AA and AA binding on CS.

  7. Bis(4-aminopyridinium hexaaquanickel(II bis(sulfate

    Directory of Open Access Journals (Sweden)

    Thameur Sahbani

    2014-01-01

    Full Text Available In the title compound, (C5H7N22[Ni(H2O6](SO42, the NiII cation is located on an inversion centre and is coordinated by six aqua ligands in a slightly distorted octahedral coordination environment. The [Ni(H2O6]2+ ions are connected through an extensive network of O—H...O hydrogen bonds to sulfate anions, leading to the formation of layers parallel to (001. The 4-aminopyridinium cations are located between these layers and are connected to the anionic framework by N—H...O hydrogen bonds. Weak π–π interactions between the pyridine rings, with a centroid–centroid distance of 3.754 (9 Å, provide additional stability to the crystal packing.

  8. Synthesis and Characterization of InS Nanorods in Sucrose Ester Water-in-Oil Microemulsion

    Directory of Open Access Journals (Sweden)

    N. M. Huang

    2011-01-01

    Full Text Available We report the synthesis of In2S3 nanorods in a nonionic sugar-based water-in-oil (w/o microemulsion system using food grade sucrose ester as biosurfactant. In2S3 was formed by mixing indium (III chloride and thioacetamide in the water core of the microemulsion system. The as-prepared yellowish In2S3 was characterized by X-ray diffractometry (XRD, UV-visible absorption spectroscopy (UV-Vis, transmission electron microscopy (TEM, and Fourier transform infrared spectroscopy (FTIR. Formation of spherical or rod-like In2S3 nanomaterials was dependent on reaction time. Rod-like In2S3, arranged in bundles, was formed only after 2 days of reaction time. Upon longer aging time, a mixture of rod-like and spherical In2S3 was formed. A plausible formation mechanism of the In2S3 nanorods in the sucrose ester microemulsion was postulated. The diameter of the In2S3 nanorods was found to be very small, which is 8.97±2.36 nm with aspect ratio of 20 : 1 (length : diameter.

  9. New double sulfates of uranyl

    International Nuclear Information System (INIS)

    Serezhkin, V.N.; Serezhkina, L.B.

    1977-01-01

    The possibility has been established of the formation of double uranyl sulphates with the composition MUO 2 (SO 4 ) 2 x5H 2 O (M=Mn or Co). These compounds are formed upon dissolution of MnSO 4 x5H 2 O or CoSO 4 x7H 2 O and UO 2 SO 4 x2.5H 2 O in a minimum amount of water with subsequent evaporation to dryness. The obtained monocrystals have been studied by X-ray structural analysis and the parameters of monoclinic elementary cells have been determined: MnUO 2 (SO 4 ) 2 x5H 2 O (a=6.524; b=11.396; c=8.362 A; β=90 deg 47') and CoUO 2 (SO 4 ) 2 x5H 2 O (a=6.448; b=11.305; c=8.286 A; β=90 deg). Possible spatial groups are P 2sub(1/m) or P2 1 ; Z=2. Thermographic study of the obtained compounds has been performed

  10. Galactose 6-sulfate sulfatase activity in Morquio syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Yutaka, T.; Okada, S.; Kato, T.; Inui, K.; Yabuuhi, H. (Osaka Univ. (Japan). Faculty of Medicine)

    1982-07-01

    The authors have prepared a new substrate, o-..beta..-D-sulfo-galactosyl-(1-4)-..beta..-D-6-sulfo-2-acetamido-2-deoxyglucosyl-(1-4)-D-(1-/sup 3/H)galactitol, from shark cartilage keratan sulfate, for the assay of galactose 6-sulfate sulfatase activity. Using this substrate, they found there was a striking deficiency of galactose 6-sulfate sulfatase activity, in addition to the known deficiency of N-acetylgalactosamine 6-sulfate sulfatase, in the cultured skin fibroblasts of patients with Morquio syndrome. Their results could be explained by the hypothesis that accumulation of keratan sulfate and chondroitin 6-sulfate in Morquio syndrome is due to a deficiency of galactose 6-sulfate sulfatase and N-acetylgalactosamine 6-sulfate sulfatase activity, which are necessary for the degradation of these two mucopolysaccharides.

  11. Galactose 6-sulfate sulfatase activity in Morquio syndrome

    International Nuclear Information System (INIS)

    Yutaka, T.; Okada, S.; Kato, T.; Inui, K.; Yabuuhi, H.

    1982-01-01

    The authors have prepared a new substrate, o-β-D-sulfo-galactosyl-(1-4)-β-D-6-sulfo-2-acetamido-2-deoxyglucosyl-(1-4)-D-[1- 3 H]galactitol, from shark cartilage keratan sulfate, for the assay of galactose 6-sulfate sulfatase activity. Using this substrate, they found there was a striking deficiency of galactose 6-sulfate sulfatase activity, in addition to the known deficiency of N-acetylgalactosamine 6-sulfate sulfatase, in the cultured skin fibroblasts of patients with Morquio syndrome. Their results could be explained by the hypothesis that accumulation of keratan sulfate and chondroitin 6-sulfate in Morquio syndrome is due to a deficiency of galactose 6-sulfate sulfatase and N-acetylgalactosamine 6-sulfate sulfatase activity, which are necessary for the degradation of these two mucopolysaccharides. (Auth.)

  12. Basement membrane chondroitin sulfate proteoglycans: localization in adult rat tissues

    DEFF Research Database (Denmark)

    McCarthy, K J; Couchman, J R

    1990-01-01

    Heparan sulfate proteoglycans have been described as the major proteoglycan component of basement membranes. However, previous investigators have also provided evidence for the presence of chondroitin sulfate glycosaminoglycan in these structures. Recently we described the production and characte...

  13. 21 CFR 172.270 - Sulfated butyl oleate.

    Science.gov (United States)

    2010-04-01

    ... HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Coatings, Films and Related Substances § 172.270 Sulfated butyl oleate. Sulfate butyl oleate may be safely...

  14. Bone sialoprotein II synthesized by cultured osteoblasts contains tyrosine sulfate

    International Nuclear Information System (INIS)

    Ecarot-Charrier, B.; Bouchard, F.; Delloye, C.

    1989-01-01

    Isolated mouse osteoblasts that retain their osteogenic activity in culture were incubated with [35S] sulfate. Two radiolabeled proteins, in addition to proteoglycans, were extracted from the calcified matrix of osteoblast cultures. All the sulfate label in both proteins was in the form of tyrosine sulfate as assessed by amino acid analysis and thin layer chromatography following alkaline hydrolysis. The elution behavior on DEAE-Sephacel of the major sulfated protein and the apparent Mr on sodium dodecyl sulfate gels were characteristic of bone sialoprotein II extracted from rat. This protein was shown to cross-react with an antiserum raised against bovine bone sialoprotein II, indicating that bone sialoprotein II synthesized by cultured mouse osteoblasts is a tyrosine-sulfated protein. The minor sulfated protein was tentatively identified as bone sialoprotein I or osteopontin based on its elution properties on DEAE-Sephacel and anomalous behavior on sodium dodecyl sulfate gels similar to those reported for rat bone sialoprotein I

  15. The Chicxulub crater - impact metamorphism of sulfate and carbonate lithologies

    Science.gov (United States)

    Deutsch, A.; Langenhorst, F.; Hornemann, U.; Ivanov, B. A.

    2003-04-01

    It is discussed whether in the aftermath of the Chicxulub event, impact-released CO_2 and SO_x have changed the Earth's climate, acting also as lethal thread for life. Undoubtedly, vaporization of carbonates and sulfates, which are major target lithologies at the Chicxulub impact site, occurred in the footprint of the projectile. What happened to these lithologies outside this very restricted zone was so far unconstrained. Petrologic observations on PEMEX and UNAM as well as on the CSDP cores allow to set up a general classification for shock-related pro-grade effects on sulfate and carbonate sedimentary rocks. Shock effects in lithic breccias are restricted to brecciation and formation of twins in calcite. Suevites mostly lack melted carbonate clasts; annealing effects in anhydrite fragments are absent. The underlying melt breccias contain anhydrite fragments still displaying a sedimentary texture, and limestone clasts, whose texture reflect crystallization from melt. Impact melt breccias from deeper levels frequently contain partially resorbed anhydrite clasts and a melt matrix with the Ca-rich mineral assemblage quartz + plagioclase + clinopyroxene; this mineral assemblage provides evidence for partial dissociation of CaSO_4. Large clasts of anhydrite consist of equant crystals with 120^o triple junctions, a feature indicative for re-crystallization in the solid state. Tagamites (impact melt rocks) are virtually free of clasts from sedimentary lithologies. These rocks have an extremely high formation temperature, which caused total dissociation of CaSO_4 and CaCO_3. Finally, up to 100 μm wide veins of anhydrite + calcite + quartz cut the matrix of all lithologies except the tagamites. They probably represent "degassing vents". The given scheme is in qualitative accordance with data of shock recovery and annealing experiments as well as with modeling results. In addition, it substantiates that annealing plays a fundamental role in the impact metamorphism of

  16. Isolation of a sulfate reducing bacterium and its application in sulfate ...

    African Journals Online (AJOL)

    The results show that the effect of C. freundii in removing sulfate was best when the temperature was 32°C, pH was 7.0, COD/SO42- was 5.0 and the initial SO42- concentration was 1500 mg/L. Also, the SRB was inoculated onto an up-flow anaerobic sludge bed (UASB) to remove sulfate in actual tannery wastewater.

  17. Growth inhibitory properties of lactose fatty acid esters

    Directory of Open Access Journals (Sweden)

    Seung-Min Lee

    2017-11-01

    Full Text Available Sugar esters are biodegradable, nonionic surfactants which have microbial inhibitory properties. The influence of the fatty acid chain length on the microbial inhibitory properties of lactose esters was investigated in this study. Specifically, lactose monooctanoate (LMO, lactose monodecanoate (LMD, lactose monolaurate (LML and lactose monomyristate (LMM were synthesized and dissolved in both dimethyl sulfoxide (DMSO and ethanol. Minimum inhibitory concentrations (MIC and minimum bactericidal concentrations (MBC were determined in growth media. LML was the most effective ester, exhibiting MIC values of <0.05 to <5 mg/ml for each Gram-positive bacteria tested (Bacillus cereus, Mycobacterium KMS, Streptococcus suis, Listeria monocytogenes, Enterococcus faecalis, and Streptococcus mutans and MBC values of <3 to <5 mg/ml for B. cereus, M. KMS, S. suis, and L. monocytogenes. LMD showed MIC and MBC values of <1 to <5 mg/ml for B. cereus, M. KMS, S. suis, L. monocytogenes, and E. faecalis, with greater inhibition when dissolved in ethanol. LMM showed MIC and MBC values of <1 to <5 mg/ml for B. cereus, M. KMS, and S. suis. LMO was the least effective showing a MBC value of <5 mg/ml for only B. cereus, though MIC values for S. suis and L. monocytogenes were observed when dissolved in DMSO. B. cereus and S. suis were the most susceptible to the lactose esters tested, while S. mutans and E. faecalis were the most resilient and no esters were effective on Escherichia coli O157:H7. This research showed that lactose esters esterified with decanoic and lauric acids exhibited greater microbial inhibitory properties than lactose esters of octanoate and myristate against Gram-positive bacteria.

  18. 21 CFR 529.1044b - Gentamicin sulfate solution.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Gentamicin sulfate solution. 529.1044b Section 529... Gentamicin sulfate solution. (a) Specifications. Each milliliter of solution contains gentamicin sulfate... solution with a gentamicin concentration of 250 to 1,000 parts per million. A concentration of 500 parts...

  19. 21 CFR 522.1484 - Neomycin sulfate sterile solution.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Neomycin sulfate sterile solution. 522.1484... § 522.1484 Neomycin sulfate sterile solution. (a) Specifications. Each milliliter of sterile aqueous solution contains 50 milligrams of neomycin sulfate (equivalent to 35 milligrams of neomycin base).1 1...

  20. 21 CFR 520.2158a - Streptomycin sulfate oral solution.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Streptomycin sulfate oral solution. 520.2158a... Streptomycin sulfate oral solution. (a) Specifications. Solution containing 25 percent streptomycin sulfate. (b... administer for more than 4 days. Prepare fresh solution daily. Calves: Withdraw 2 days before slaughter. As...

  1. 21 CFR 582.1131 - Aluminum sodium sulfate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Aluminum sodium sulfate. 582.1131 Section 582.1131 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1131 Aluminum sodium sulfate. (a) Product. Aluminum sodium sulfate. (b) Conditions of use...

  2. 21 CFR 182.1131 - Aluminum sodium sulfate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Aluminum sodium sulfate. 182.1131 Section 182.1131 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD... Substances § 182.1131 Aluminum sodium sulfate. (a) Product. Aluminum sodium sulfate. (b) Conditions of use...

  3. 21 CFR 182.1129 - Aluminum potassium sulfate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Aluminum potassium sulfate. 182.1129 Section 182.1129 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Food Substances § 182.1129 Aluminum potassium sulfate. (a) Product. Aluminum potassium sulfate. (b...

  4. 21 CFR 582.1129 - Aluminum potassium sulfate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Aluminum potassium sulfate. 582.1129 Section 582.1129 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Additives § 582.1129 Aluminum potassium sulfate. (a) Product. Aluminum potassium sulfate. (b) Conditions of...

  5. 21 CFR 582.1127 - Aluminum ammonium sulfate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Aluminum ammonium sulfate. 582.1127 Section 582.1127 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Additives § 582.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate. (b) Conditions of...

  6. 21 CFR 182.1127 - Aluminum ammonium sulfate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Aluminum ammonium sulfate. 182.1127 Section 182.1127 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Food Substances § 182.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate. (b...

  7. Application of ethyl esters and d3-methyl esters as internal standards for the gas chromatographic quantification of transesterified fatty acid methyl esters in food.

    Science.gov (United States)

    Thurnhofer, Saskia; Vetter, Walter

    2006-05-03

    Ethyl esters (FAEE) and trideuterium-labeled methyl esters (d3-FAME) of fatty acids were prepared and investigated regarding their suitability as internal standards (IS) for the determination of fatty acids as methyl esters (FAME). On CP-Sil 88, ethyl esters of odd-numbered fatty acids eluted approximately 0.5 min after the respective FAME, and only coelutions with minor FAME were observed. Depending on the problem, one or even many FAEE can be added as IS for the quantification of FAME by both GC-FID and GC-MS. By contrast, d3-FAME coeluted with FAME on the polar GC column, and the use of the former as IS requires application of GC-MS. In the SIM mode, m/z 77 and 90 are suggested for d3-methyl esters of saturated fatty acids, whereas m/z 88 and 101 are recommended for ethyl esters of saturated fatty acids. These m/z values give either no or very low response for FAME and can thus be used for the analysis of FAME in food by GC-MS in the SIM mode. Fatty acids in sunflower oil and mozzarella cheese were quantified using five saturated FAEE as IS. Gravimetric studies showed that the transesterification procedure could be carried out without of loss of fatty acids. GC-EI/MS full scan analysis was suitable for the quantitative determination of all unsaturated fatty acids in both food samples, whereas GC-EI/MS in the SIM mode was particularly valuable for quantifying minor fatty acids. The novel GC-EI/MS/SIM method using fatty acid ethyl esters as internal standards can be used to quantify individual fatty acids only, that is, without determination of all fatty acids (the common 100% method), although this is present. This was demonstrated by the exclusive quantification of selected fatty acids including methyl-branched fatty acids, erucic acid (18:1n-9trans), and polyunsaturated fatty acids in cod liver oil and goat's milk fat.

  8. Mineral dust and NOx promote the conversion of SO2 to sulfate in heavy pollution days.

    Science.gov (United States)

    He, Hong; Wang, Yuesi; Ma, Qingxin; Ma, Jinzhu; Chu, Biwu; Ji, Dongsheng; Tang, Guiqian; Liu, Chang; Zhang, Hongxing; Hao, Jiming

    2014-02-25

    Haze in China has been increasing in frequency of occurrence as well as the area of the affected region. Here, we report on a new mechanism of haze formation, in which coexistence with NOx can reduce the environmental capacity for SO2, leading to rapid conversion of SO2 to sulfate because NO2 and SO2 have a synergistic effect when they react on the surface of mineral dust. Monitoring data from five severe haze episodes in January of 2013 in the Beijing-Tianjin-Hebei regions agreed very well with the laboratory simulation. The combined air pollution of motor vehicle exhaust and coal-fired flue gases greatly reduced the atmospheric environmental capacity for SO2, and the formation of sulfate was found to be a main reason for the growth of fine particles, which led to the occurrence of haze. These results indicate that the impact of motor vehicle exhaust on the atmospheric environment might be underestimated.

  9. Efficient ozone, sulfate, and ammonium free resist stripping process

    Science.gov (United States)

    Dattilo, Davide; Dietze, Uwe

    2014-07-01

    In recent years, photomask resist strip and cleaning technology development was substantially driven by the industry's need to prevent surface haze formation through the elimination of sulfuric acid and ammonium hydroxide from these processes. As a result, conventional SPM (H2SO4 + H2O2) was replaced with Ozone water (DIO3) for resist stripping and organic removal to eliminate chemical haze formation [1, 2]. However, it has been shown that DIO3 basted strip and clean process causes oxidative degradation of photomask materials [3, 4]. Such material damage can affect optical properties of funcitional mask layers, causeing CD line-width, phase, transmission and reflection changes, adversely affecting image transfer during the Lithography process. To overcome Ozone induced surface damage, SUSS MicroTec successfully developed a highly efficient strip process, where photolysis of DIO3 is leading to highly reactive hydroxyl radical formation, as the main contribution to hydrocarbon removal without surface damage [5]. This technology has been further extended to a final clean process, which is utilizing pure DI water for residual organic material removal during final clean [6]. Recently, SUS MicroTec did also successfully release strip and clean processes which completely remove NH4OH, eliminating any chemicals known today to induce haze [7]. In this paper we show the benefits of these new technologies for highly efficient sulfate and ammonium free stripping and cleaning processes.

  10. Acid Sulfate Alteration in Gusev Crater, Mars

    Science.gov (United States)

    Morris, R. V.; Ming, D. W.; Catalano, J. G.

    2016-01-01

    The Mars Exploration Rover (MER) Spirit landed on the Gusev Crater plains west of the Columbia Hills in January, 2004, during the Martian summer (sol 0; sol = 1 Martian day = 24 hr 40 min). Spirit explored the Columbia Hills of Gusev Crater in the vicinity of Home Plate at the onset on its second winter (sol approximately 900) until the onset of its fourth winter (sol approximately 2170). At that time, Spirit became mired in a deposit of fined-grained and sulfate-rich soil with dust-covered solar panels and unfavorable pointing of the solar arrays toward the sun. Spirit has not communicated with the Earth since sol 2210 (January, 2011). Like its twin rover Opportunity, which landed on the opposite side of Mars at Meridiani Planum, Spirit has an Alpha Particle X-Ray Spectrometer (APXS) instrument for chemical analyses and a Moessbauer spectrometer (MB) for measurement of iron redox state, mineralogical speciation, and quantitative distribution among oxidation (Fe(3+)/sigma Fe) and coordination (octahedral versus tetrahedral) states and mineralogical speciation (e.g., olivine, pyroxene, ilmenite, carbonate, and sulfate). The concentration of SO3 in Gusev rocks and soils varies from approximately 1 to approximately 34 wt%. Because the APXS instrument does not detect low atomic number elements (e.g., H and C), major-element oxide concentrations are normalized to sum to 100 wt%, i.e., contributions of H2O, CO2, NO2, etc. to the bulk composition care not considered. The majority of Gusev samples have approximately 6 plus or minus 5 wt% SO3, but there is a group of samples with high SO3 concentrations (approximately 30 wt%) and high total iron concentrations (approximately 20 wt%). There is also a group with low total Fe and SO3 concentrations that is also characterized by high SiO2 concentrations (greater than 70 wt%). The trend labeled "Basaltic Soil" is interpreted as mixtures in variable proportions between unaltered igneous material and oxidized and SO3-rich basaltic

  11. Recovery of Scandium from Leachate of Sulfation-Roasted Bayer Red Mud by Liquid-Liquid Extraction

    Science.gov (United States)

    Liu, Zhaobo; Li, Hongxu; Jing, Qiankun; Zhang, Mingming

    2017-11-01

    The leachate obtained from sulfation-roasted Bayer red mud is suitable for extraction of scandium by liquid-liquid solvent extraction because it contains trace amounts of Fe3+ and Si4+. In this study, a completely new metallurgical process for selective recovery of scandium from Bayer red mud was proposed. The extraction performances of Sc3+, Fe3+, Al3+, Si4+, Ca2+, and Na+ from synthetic leachate of sulfation-roasted red mud were first investigated using organophosphorus extractants (di-2-ethylhexyl phosphoric acid P204 and 2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester P507) and carboxylic acid extractant (Versatic acid 10). It shows that P204 has an excellent extraction ability and that it can be applied to the scandium recovery. P507 and Versatic acid 10 are much poorer in performance for selective extraction of scandium. In the leachate of sulfation-roasted red mud, approximately 97% scandium can be recovered using a P204/sulfonated kerosene (1% v/v) extraction system under the condition of an organic-to-aqueous phase ratio of 10:1 and with an extraction temperature of 15°C.

  12. Synthesis of methyl ester sulfonate surfactant from crude palm oil as an active substance of laundry liquid detergent

    Science.gov (United States)

    Slamet, Ibadurrohman, Muhammad; Wulandari, Pangiastika Putri

    2017-11-01

    Liquid detergent with combination of MES surfactant and TiO2 nanoparticles to remove and degrade the dirt in the form of methylene blue and produce waste with the lowest surfactant residual concentration has been done. The formation of MES is carried out by esterification and transesterification of crude palm oil, sulfonation, refining, and neutralization. The photocatalyst TiO2 nanoparticles is added as an additive to improve surfactant performance in removing dirt and degrading organic compounds. MES formation is performed by varying the mole ratio of the reactants in the esterification and transesterification reactions, and the mole ratios between methyl esters and NaHSO3 during the sulfonation reaction. Variations of MES surfactant and TiO2 nanoparticles compositions were performed to obtain detergent stability. Data analysis technique in this research is characterization of methyl ester, MES surfactant, and detergent using UV-Vis spectrophotometer instrument, FTIR, GC-MS, and LC-MS. The optimum conditions in the esterification and transesterification process were each mole ratio of 1: 6 between CPO and methanol based on the highest conversion, 99%. The optimum condition of the sulfonation process is the 1: 1.5 mole ratio between methyl ester and NaHSO3 based on the lowest surface tension value, which is about 36 dyne/cm.

  13. Resolution of Racemic Acids, Esters and Amines by Candida rugosa Lipase in Slightly Hydrated Organic Media

    Directory of Open Access Journals (Sweden)

    Andrés R. Alcántara

    2004-01-01

    Full Text Available Commercial crude lipase from Candida rugosa is widely used as a biocatalyst in the resolution of racemic mixtures and in organic synthesis in slightly hydrated organic solvents. In many cases, reproducible results are not obtained when the same crude lipase is used, but from different suppliers of lots, this being due to the presence of different isoenzymes. The current work addresses this problem and strategies to overcome it. The yeast Candida rugosa ATCC 14380 was cultivated in a minimal culture medium, using different substances as inducers and carbon sources. The percentage of inducer that gave the optimum productivity of extracellular lipases was determined. Lyophilized extracellular enzymes were characterized by SDS-PAGE electrophoresis and isoelectric focusing (IEF. Depending on the nature of the carbon source, different isoenzymes were produced in various proportions. These samples were partially purified by different methodologies, including dialysis, adsorption chromatography and precipitation with ammonium sulfate or organic solvents. These characterizations allowed us to explain the relative catalytic activity of different samples, showing that in biocatalysis enzymes should not be treated simply as a »white magic powder« that can solve all the challenges in organic synthesis. Heptyl oleate synthesis, alcoxycarbonylation of amines and hydrolysis of the ester of ketoprofen are excellent reaction tests for the evaluation of lipase samples as biocatalysts.

  14. Phytosterol ester constituents affect micellar cholesterol solubility in model bile.

    Science.gov (United States)

    Brown, Andrew W; Hang, Jiliang; Dussault, Patrick H; Carr, Timothy P

    2010-09-01

    Plant sterols and stanols (phytosterols) and their esters are nutraceuticals that lower LDL cholesterol, but the mechanisms of action are not fully understood. We hypothesized that intact esters and simulated hydrolysis products of esters (phytosterols and fatty acids in equal ratios) would differentially affect the solubility of cholesterol in model bile mixed micelles in vitro. Sodium salts of glycine- and taurine-conjugated bile acids were sonicated with phosphatidylcholine and either sterol esters or combinations of sterols and fatty acids to determine the amount of cholesterol solubilized into micelles. Intact sterol esters did not solubilize into micelles, nor did they alter cholesterol solubility. However, free sterols and fatty acids altered cholesterol solubility independently (no interaction effect). Equal contents of cholesterol and either campesterol, stigmasterol, sitosterol, or stigmastanol (sitostanol) decreased cholesterol solubility in micelles by approximately 50% compared to no phytosterol present, with stigmasterol performing slightly better than sitosterol. Phytosterols competed with cholesterol in a dose-dependent manner, demonstrating a 1:1 M substitution of phytosterol for cholesterol in micelle preparations. Unsaturated fatty acids increased the micelle solubility of sterols as compared with saturated or no fatty acids. No differences were detected in the size of the model micelles. Together, these data indicate that stigmasterol combined with saturated fatty acids may be more effective at lowering cholesterol micelle solubility in vivo.

  15. Development of continuous deglycerolisation reactor for ethyl ester production

    Directory of Open Access Journals (Sweden)

    Ruamporn Nikhom

    2014-12-01

    Full Text Available In this work, the development of continuous deglycerolisation (CD reactor for ethyl ester production was investigated to improve the ethyl ester conversion. The device to assist separation of glycerol, in the CD unit, integrates transesterification (mixing zone and separation (settling zone into one unit. For reversible transesterification, removing glycerol during reaction can drive the equilibrium to the product side in order to achieve high conversion. Two models of device to assist separation of glycerol have been carried out to investigate the suitable conditions for ethyl ester production. Results showed that the fin-type model could separate higher amount of glycerol from the reaction system in order to achieve high transesterification conversion. The suitable conditions found in this study were: molar ratio of oil to ethanol of 1:5, KOCH3 concentration of 1.6 %wt. retention time of 15 min and reaction temperature of 70°C. At these conditions, ethyl ester’s purity and yield were 97.3%wt. and 92.0%wt., respectively. In addition, the fuel properties of the final ethyl ester product met the biodiesel standard for methyl ester which specified by Department of Energy Business.

  16. Constraining Δ33S signatures of Archean seawater sulfate with carbonate-associated sulfate

    Science.gov (United States)

    Peng, Y.; Bao, H.; Bekker, A.; Hofmann, A.

    2017-12-01

    Non-mass dependent sulfur isotope deviation of S-bearing phases in Archean sedimentary strata, and expressed as Δ33S, has a consistent pattern, i.e., sulfide (pyrite) predominantly bear positive Δ33S values, while Paleoarchean sulfate (barite) has negative Δ33S values. This pattern was later corroborated by observations of negative Δ33S values in Archean volcanogenic massive sulfide deposits and negative Δ33S values in early diagenetic nodular pyrite with a wide range of δ34S values, which is thought to be due to microbial sulfate reduction. These signatures have provided a set of initial conditions for a mechanistic interpretation at physical chemistry level. Unlike the younger geological times when large bodies of seawater evaporite deposits are common, to expand seawater sulfate records, carbonate-associated sulfate (CAS) was utilized as a proxy for ancient seawater sulfate. CAS extracted from the Archean carbonates carries positive Δ33S values. However, CAS could be derived from pyrite oxidation following exposure to modern oxidizing conditions and/or during laboratory extraction procedures. It is, therefore, important for us understanding context of the overall early earth atmospheric condition to empirically confirm whether Archean seawater sulfate was generally characterized by negative Δ33S signatures. Combined δ18O, Δ17O, δ34S, and Δ33S analyses of sequentially extracted water-leachable sulfate (WLS) and acid-leachable sulfate (ALS = CAS) and δ34S and Δ33S analyses of pyrite can help to identify the source of extracted sulfate. We studied drill-core samples of Archean carbonates from the 2.55 Ga Malmani and Campell Rand supgroups, South Africa. Our preliminary results show that 1) neither WLS nor ALS were extracted from samples with extremely low pyrite contents (less than 0.05 wt.%); 2) extractable WLS and ALS is present in samples with relatively high pyrite contents (more than 1 wt.%), and that δ34S and Δ33S values of WLS, ALS, and

  17. Determination of testosterone esters and estradiol esters in bovine and porcine blood serum.

    Science.gov (United States)

    Rejtharová, Martina; Rejthar, Libor; Čačková, Katarína

    2017-04-01

    Monitoring of steroid esters in blood serum is desirable in order to detect the possible illegal use of natural hormones as growth promoters. A method for the determination of testosterone propionate, testosterone benzoate, testosterone isocaproate, testosterone decanoate and estradiol benzoate in bovine and porcine blood serum was developed. The procedure consists of protein precipitation and removal of phospholipids using a HybridSPE®-Phospholipid column followed by clean-up on a hydrophilic modified styrene polymer Supel TM -Select HLB column and LC-MS/MS measurement. The method was validated according to Commission Decision 2002/657/EC. Decision limits for all analytes were observed in the range 5-30 pg ml - 1 . The method was shown to be robust for bovine and porcine serum analyses and can be applied for both screening and confirmatory determination in routine residue monitoring.

  18. Aerosol pH buffering in the southeastern US: Fine particles remain highly acidic despite large reductions in sulfate

    Science.gov (United States)

    Weber, R. J.; Guo, H.; Russell, A. G.; Nenes, A.

    2015-12-01

    pH is a critical aerosol property that impacts many atmospheric processes, including biogenic secondary organic aerosol formation, gas-particle phase partitioning, and mineral dust or redox metal mobilization. Particle pH has also been linked to adverse health effects. Using a comprehensive data set from the Southern Oxidant and Aerosol Study (SOAS) as the basis for thermodynamic modeling, we have shown that particles are currently highly acidic in the southeastern US, with pH between 0 and 2. Sulfate and ammonium are the main acid-base components that determine particle pH in this region, however they have different sources and their concentrations are changing. Over 15 years of network data show that sulfur dioxide emission reductions have resulted in a roughly 70 percent decrease in sulfate, whereas ammonia emissions, mainly link to agricultural activities, have been largely steady, as have gas phase ammonia concentrations. This has led to the view that particles are becoming more neutralized. However, sensitivity analysis, based on thermodynamic modeling, to changing sulfate concentrations indicates that particles have remained highly acidic over the past decade, despite the large reductions in sulfate. Furthermore, anticipated continued reductions of sulfate and relatively constant ammonia emissions into the future will not significantly change particle pH until sulfate drops to clean continental background levels. The result reshapes our expectation of future particle pH and implies that atmospheric processes and adverse health effects linked to particle acidity will remain unchanged for some time into the future.

  19. Introduction of sulfate groups on poly(ethylene) surfaces by argon plasma immobilization of sodium alkyl sulfates

    NARCIS (Netherlands)

    Lens, J.P.; Lens, J.P.; Terlingen, J.G.A.; Terlingen, J.G.A.; Engbers, G.H.M.; Feijen, Jan

    1998-01-01

    Sulfate groups were introduced at the surface of poly(ethylene) (PE) samples. This was accomplished by immobilizing a precoated layer of either sodium 10-undecene sulfate (S11(:)) or sodium dodecane sulfate (SDS) on the polymeric surface by means of an argon plasma treatment. For this purpose,

  20. Regioselective sulfonation of dopamine by SULT1A3 in vitro provides a molecular explanation for the preponderance of dopamine-3-O-sulfate in human blood circulation.

    Science.gov (United States)

    Itäaho, Katriina; Alakurtti, Sami; Yli-Kauhaluoma, Jari; Taskinen, Jyrki; Coughtrie, Michael W H; Kostiainen, Risto

    2007-08-01

    SULT1A3 is an enzyme that catalyzes the sulfonation of many endogenous and exogenous phenols and catechols. The most important endogenous substrate is dopamine (DA), which is often used as a probe substrate for SULT1A3. We developed a new method for analyzing the SULT1A3 reaction products by high-performance liquid chromatography (HPLC) with electrochemical detection. The sulfonate donor 3'-phosphoadenosine-5'-phosphosulfate (PAPS), DA and the two dopamine sulfates, DA-3-O-sulfate and DA-4-O-sulfate, can be separated within 3 min. This enables quantitation of the sulfates without radioactive PAPS or the precipitation of unreacted PAPS. Both sulfates were synthesized as reference substances and characterized by (1)H and (13)C nuclear magnetic resonance (NMR), mass spectrometry (MS) and tandem mass spectrometry (MS/MS). The purity of the dopamine sulfates was estimated by HPLC using a diode array detector. We determined the enzyme kinetic parameters for formation of DA-3-O-sulfate and DA-4-O-sulfate using purified recombinant human SULT1A3. The reactions followed Michaelis-Menten kinetics up to 50 microM DA concentration, and strong substrate inhibition was observed at higher concentrations. The apparent K(m) values for sulfonation at both hydroxy groups were similar (2.21+/-0.764 and 2.59+/-1.06 microM for DA-4-O-sulfate and DA-3-O-sulfate, respectively), but the V(max) was approximately six times higher for the formation of the 3-O-sulfate (344+/-139 nmol/min/mg protein) than the 4-O-sulfate (45.4+/-16.5 nmol/min/mg protein). These results are in accordance with the observation that DA-3-O-sulfate is more abundant in human blood than DA-4-O-sulfate and that in the crystal structure of SULT1A3 with dopamine bound to the active site, the 3-hydroxy group is aligned to form hydrogen bonds with catalytic residues of the enzyme.