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Sample records for anisoles

  1. Thermal, Spectroscopic and Chemical Characterization of Biofield Energy Treated Anisole

    OpenAIRE

    Trivedi, Mahendra Kumar

    2015-01-01

    The objective of the present study was to evaluate the impact of biofield energy treatment on the thermal, spectroscopic, and chemical properties of anisole by various analytical methods such as gas chromatography-mass spectrometry (GC-MS), high performance liquid chromatography (HPLC), differential scanning calorimetry (DSC), Fourier transform infrared (FT-IR) spectroscopy, and ultraviolet-visible (UV-Vis) spectroscopy. The anisole sample was divided into two parts, control and treated. The ...

  2. Developmental immunotoxicity testing of 4-methyl anisole.

    Science.gov (United States)

    Tonk, Elisa C M; Verhoef, Aart; Gremmer, Eric R; van Loveren, Henk; Piersma, Aldert H

    2015-07-01

    The developmental immunotoxicity of 4-methyl anisole (4MA) was investigated in the rat. Four study designs were used, with either premating or post-weaning onset of exposure, continued to postnatal day 50, and with or without additional oral gavage of pups from postnatal day 10 onward. Reduced litter size (benchmark dose lower confidence limit (BMDL) 80mg/kg bw/day) was the most sensitive developmental parameter, with pup relative organ weight effects observed at similar BMDLs, in the absence of maternal toxicity. Eosinophil numbers were reduced at lower doses (BMDL 16mg/kg bw/day). KLH challenge resulted in increased IL-13 and TNF-α responses, and variably reduced IgG production (BMDL 27mg/kg bw/day). T4 levels were reduced by 11% at maximum with a BMDL of 73mg/kg bw/day. Differences between exposure cohorts were limited and were considered to be without biological significance. This study shows that 4MA induces developmental immunotoxicity at doses below those inducing developmental and general toxicity. These observations being independent of the study designs applied suggest that the post-weaning period, included in all designs, is the most relevant sensitive period for inducing 4MA mediated developmental immunotoxicity. Moreover, this study stresses the importance of including developmental immunotoxicity testing by default in regulatory toxicology. PMID:25882306

  3. Enhanced solar light absorption of graphene by interaction with anisole

    KAUST Repository

    Kahaly, Mousumi Upadhyay

    2014-10-01

    We study suspended graphene in contact with the organic molecule anisole to analyse the implications of the interaction for the optical absorption, using first principle calculations. Because of a weak interaction multiple orientations of the molecule with respect to the graphene sheet are possible. A substantial enhancement of the optical absorption independent of the specific orientation is observed, which is promising for energy harvesting. © 2014 Elsevier Ltd. All rights reserved.

  4. 2,4-Difluoro anisole. A promising complexing agent for boron isotopes separation by chemical exchange reaction and distillation

    International Nuclear Information System (INIS)

    Although methods of boron isotopes separation were intensively pursued about 60 years, the chemical exchange distillation is the only method that has been applied in industrial scale production of 10B. The present anisole BF3 system suffers from the drawbacks like high melting point, relatively low separation coefficient and instability under reaction conditions, which demand a continuous search for more effective and efficient donors for boron isotope separation. A series of fluoro-substituted anisole derivatives were screened in this paper, among which 2,4-difluoro anisole exhibited good properties compared with anisole. Studies on the boron trifluoride and 2,4-difluoro anisole adduct, its thermodynamic and physical properties related to large-scale isotopic separation is reported. The results showed that 2,4-difluoro anisole is better than anisole in separation coefficient, freezing point and stability under pyrolysis conditions, which suggest a further detailed investigations on boron trifluoride and 2,4-difluoro anisole adduct. (author)

  5. Synthesis of 4-Methylene-2-cyclohexenones and Their Aromatization Reaction toward para-Methoxylmethyl Anisole Derivatives

    International Nuclear Information System (INIS)

    We and other groups have reported the selective introduction of nucleophiles at the secondary benzylic position of the Baylis-Hillman acetates via the corresponding DABCO salts. Thus, we envisioned that we could prepare 4-methylene- 2-cyclohexenone skeleton and para-methoxymethyl anisoles by combining the DABCO salt concept and the aromatization reaction with iodine in methanol. Suitably substituted anisoles are useful as the starting materials for the fragrances, dyes and pesticides, as antioxidants in oils and fats, or as stabilizers of plastics. Moreover, paramethoxymethyl anisoles have been used for the kinetic acetalization of diol or amino alcohol systems in the presence of DDQ5 during the synthesis of (+)-FR900482, taxotere side chain,5c cyclopropyl lactone oxylipins, and erythromycin A.

  6. ASETILASI PADA FENOL DAN ANISOL MENGGUNAKAN ANHIDRIDA ASAM ASETAT BERKATALIS Zr4+-ZEOLIT BETA

    Directory of Open Access Journals (Sweden)

    DA Retnoningrum

    2015-07-01

    Full Text Available Zeolit beta pada umumnya memiliki keasaman tinggi dan berpotensi aktif sebagai katalis heterogen dalam asilasi Friedel-Crafts senyawa aromatik. Untuk meningkatkan stabilitas dan selektivitasnya, zeolit beta perlu diaktivasi dan dimodifikasi terlebih dahulu dengan mengembankan logam aktif zirkonium dengan metode pertukaran ion. Karakterisasi katalis meliputi analisis kristalinitas katalis dengan XRD, sifat permukaan katalis dengan Surface Area Analyzer dan uji keasaman dengan pengadsorbsi piridin. Dalam penelitian ini, dipelajari aktivitas dan selektivitas katalis Zr4+-zeolit beta dalam reaksi asetilasi fenol dan anisol. Reaksi dilakukan pada berbagai variasi suhu yaitu 100 dan 130C dengan waktu reaksi yaitu pada jam ke 4, 8 dan 12. Hasil asetilasi kemudian dianalisis menggunakan GC, FTIR dan analisis produk menggunakan GC-MS. Asetilasi fenol dengan katalis Zr4+-zeolit beta menghasilkan produk fenil etanoat dengan kadar 95,87% dan selektivitas 100%. Hasil ini didapatkan pada suhu reaksi 130C dan waktu reaksi 8 jam. Asetilasi pada cincin benzena baik pada fenol maupun anisol tidak terjadi, hal ini karena asetilasi pada cincin benzena lebih sukar dibandingkan asetilasi pada gugus OH fenol. Perlu adanya kondisi lain untuk melakukan asetilasi pada cincin benzena. Asetilasi anisol pada waktu reaksi 24 jam dan temperatur 130C didapatkan produk dengan kadar 74%.Beta zeolite generally has a high acidity and potentially active as heterogeneous catalyst in the Friedel-Crafts acylation of aromatic compounds. To improve its stability and selectivity, beta zeolite needs to be activated and modified in advance with zirconium to elicit active metal using ion exchange method. Characterization of catalyst include catalyst’s crystallinity using XRD analysis, the nature of the catalyst surface with the Surface Area Analyzer and the acidity test using pyridine adsorption. In the current study the activity and the selectivity of catalyst Zr4+-beta zeolite

  7. Oxidation of some disubstituted anisole derivatives with ceric perchlorate in perchloric acid solution

    International Nuclear Information System (INIS)

    The influence of concentration of particular reagents on the kinetics of Ce(IV) reduction by 2,6-dimethyl and 3,5-dimethyl-anisole as well as 2-methoxy-5-methyl- and 4-methoxy-2-methyl-aniline in perchloric acid solution was investigated, establishing the stoichiometry of these processes. Some intermediate products - macromolecular, derivatives of p-benzoquinone and 4,4'-diphenoquinone - were separated and identified. The effects of substituents and the conditions of performed oxidation processes on the kind and yields of the resultant products were considered. (author). 22 refs, 1 fig., 1 tab

  8. Determination of Henry's law constants for low volatile mixed halogenated anisoles using solid-phase microextraction

    International Nuclear Information System (INIS)

    Trihalogenated anisoles (THAs) that have been identified at low concentration levels (ngL-1) in drinking water are suspected of causing odor episodes, which are a frequent source of complaint by consumers. Henry's law constant (KH) is an important parameter in controlling the diffusion of organic compounds from the water to the vapor-phase, so its evaluation is of significance in the study of odor events. In this paper, the KH of a wide range of trihalogenated anisoles - in its dimensionless form K'H - were calculated at two temperatures, 45 and 22deg. C using equilibration partitioning in a closed system and headspace microextraction (EPICS-SPME). Two methodological approaches, Ramachandran and Dewulf, were used for the assessment of the Henry's law constant. Nevertheless, to apply these methods to THAs, a relatively narrow headspace/water volume ratio range (80/1-8/1) is required. At these conditions, a linearity (r2) using Ramachandran's theoretical relationship from 0.9276 to 0.9989 was obtained and the variability (R.S.D.%) when Dewulf's theoretical relationship was employed was lower than 20% (n=5)

  9. To π or not to π--how does methanol dock onto anisole?

    Science.gov (United States)

    Heger, Matthias; Altnöder, Jonas; Poblotzki, Anja; Suhm, Martin A

    2015-05-21

    Anisole offers two similarly attractive hydrogen bond acceptor sites to an incoming hydrogen bond donor: its oxygen atom and its delocalized π electron system. Electronic structure calculations up to the CCSD(T)/AVTZ level suggest an isoenergetic situation for methanol after harmonic zero point energy correction, within less than 1 kJ mol(-1). Linear infrared absorption spectroscopy in the OH stretching fundamental range applied to a cold supersonic jet expansion of anisole and methanol in helium shows that the oxygen binding site is preferred, with about 20 times less π-bonded than O-bonded dimers despite the non-equilibrium collisional environment. Accidental band overlap is ruled out by OH overtone and OD stretching spectroscopy. Furthermore, the diagonal anharmonicity constant of the OH stretching mode is derived from experiment and reaches 80% of the monomer distortion found in the methanol dimer, as expected for a weaker hydrogen bond to the aromatically substituted oxygen. To reconcile these experimental findings with ab initio theory, accurate nuclear and electronic structure calculations involving AVQZ basis sets are required. Dispersion-corrected double-hybrid density functional theory provides a less expensive successful structural approach. PMID:25913024

  10. Control over the Hydrogen-Bond Docking Site in Anisole by Ring Methylation.

    Science.gov (United States)

    Gottschalk, Hannes C; Altnöder, Jonas; Heger, Matthias; Suhm, Martin A

    2016-01-26

    The supramolecular docking of methanol to anisole may occur via an OH⋅⋅⋅O hydrogen bond or via an OH⋅⋅⋅π contact. The subtle balance between these two structures can be varied in supersonic jets by one order of magnitude through single to triple methylation of the aromatic ring and introduction of a single tert-butyl substituent, as evidenced by infrared spectroscopy. This steep variation makes it possible to assess the accuracy of relative quantum-chemical energy predictions on a kJ mol(-1) level, promising insights into inductive, mesomeric, and dispersive effects. The zero-point-corrected B3LYP-D3/aVTZ level is shown to provide an accurate relative description of the two very different hydrogen bonds, similar to a wavefunction-based protocol including CCSD(T) corrections applied to the same structures. M06-2X alone systematically overestimates the stability of π coordination. PMID:26695475

  11. Alternative sorptive extraction method for gas chromatography determination of halogenated anisoles in water and wine samples

    Energy Technology Data Exchange (ETDEWEB)

    Montes, R. [Departamento de Quimica Analitica, Nutricion y Bromatologia, Instituto de Investigacion y Analisis Alimentario, Universidad de Santiago de Compostela, Santiago de Compostela 15782 (Spain); Rodriguez, I. [Departamento de Quimica Analitica, Nutricion y Bromatologia, Instituto de Investigacion y Analisis Alimentario, Universidad de Santiago de Compostela, Santiago de Compostela 15782 (Spain)], E-mail: qnisaac@usc.es; Rubi, E.; Bollain, M.H.; Cela, R. [Departamento de Quimica Analitica, Nutricion y Bromatologia, Instituto de Investigacion y Analisis Alimentario, Universidad de Santiago de Compostela, Santiago de Compostela 15782 (Spain)

    2007-09-05

    An alternative sorptive microextraction method for the determination of five halogenated anisoles in water and wine matrices is proposed. Analytes were concentrated in an inexpensive and disposable piece of bulk polydimethylsiloxane (PDMS), desorbed with a small volume of organic solvent, and determined by gas chromatography with electron-capture detection (GC-ECD) or tandem mass spectrometry (GC-MS/MS). The influence of several factors on the efficiency of extraction and desorption steps was investigated in detail and the observed behaviour justified on the basis of thermodynamics and kinetics of the solid-phase microextraction technique. Under optimised conditions, analytes were first extracted in the headspace (HS) mode, at room temperature, for 2.5 h and then desorbed with 1 mL of n-pentane. This extract was further evaporated to 50 {mu}L. The overall extraction yield of the procedure ranged from 40 to 55% and the limits of quantification remained between 0.5 and 20 ng L{sup -1}, depending on the compound considered and the detection technique. Precision and linearity of the method were excellent for all species with both GC-ECD and GC-MS/MS detection. Matrix effects were evaluated with different water and wine samples; moreover, the suitability of the PDMS sorbent for storage of analytes, under different conditions, was demonstrated.

  12. Alternative sorptive extraction method for gas chromatography determination of halogenated anisoles in water and wine samples

    International Nuclear Information System (INIS)

    An alternative sorptive microextraction method for the determination of five halogenated anisoles in water and wine matrices is proposed. Analytes were concentrated in an inexpensive and disposable piece of bulk polydimethylsiloxane (PDMS), desorbed with a small volume of organic solvent, and determined by gas chromatography with electron-capture detection (GC-ECD) or tandem mass spectrometry (GC-MS/MS). The influence of several factors on the efficiency of extraction and desorption steps was investigated in detail and the observed behaviour justified on the basis of thermodynamics and kinetics of the solid-phase microextraction technique. Under optimised conditions, analytes were first extracted in the headspace (HS) mode, at room temperature, for 2.5 h and then desorbed with 1 mL of n-pentane. This extract was further evaporated to 50 μL. The overall extraction yield of the procedure ranged from 40 to 55% and the limits of quantification remained between 0.5 and 20 ng L-1, depending on the compound considered and the detection technique. Precision and linearity of the method were excellent for all species with both GC-ECD and GC-MS/MS detection. Matrix effects were evaluated with different water and wine samples; moreover, the suitability of the PDMS sorbent for storage of analytes, under different conditions, was demonstrated

  13. The base-catalyzed H/D--exchange of anisole moiety of ruthenium complex in cooperation with demethylation by hydroxide anion in methanol-d4

    International Nuclear Information System (INIS)

    [Ru (η5-C5H5)(η6-arene A)]BF4 (arene A = nitrobenzene, m- or p-nitrotoluene, anisole, phenetole, m- or p-methylanisole) were quantitatively converted to pure [Ru(η5-C5H5)(η-arene B)]BF4 (arene B = phenoxido-2d, m- or p-monodeuterated methylphenoxido) in the presence of excess KOH in CD3OD, whereas [Ru(η5-C5H5)(η6-anisole)]BF4 was quantitatively obtained by treatment [Ru(η5-C5H5)(η6-nitrobenzene)]BF4 with 1 equivalent KOH or CH3OK. (author)

  14. Effect of antioxidant butylated hydroxyl anisole on the thermal or oxidative stability of sunflower oil (Helianthus Annuus) by ultrasonic.

    Science.gov (United States)

    Murari, Satish Kumar; Shwetha, M V

    2016-01-01

    The aim of the current investigation was to evaluate the efficiency of butylated hydroxyl anisole (BHA) as an antioxidant in sunflower oil (Helianthus Annuus). The oxidation stability of sunflower oil have been investigated by the effects of varying amounts of BHA. The antioxidant incorporated sunflower oil system and control edible oil were subjected to heating at 180 ± 5 °C continuously for a period of 4 h per day for consecutive 4 days. The parameters used to assess the thermal degradation and oxidation properties of the oils include ultrasonic velocity, viscosity, density and peroxide value. The fatty acid compositions of the oils were measured by gas chromatography. Adiabatic compressibility, intermolecular free length, relaxation time and acoustic impedance have been calculated from experimental data. Viscosity, density and ultrasonic velocity change in control oil is from 3.72 × 10(-2) to 13.2 × 10(-2) Nsm - 2, 918 to 994 kg/m3 and 1412 to 1484 m/s respectively and in sunflower oil with 200 ppm BHA is from 3.88 × 10(-2) to 7.52 × 10(-2) Nsm - 2, 926 to 962 kg/m3 and 1418 to 1463 m/s respectively for 16 h of heat treated oil. The ultrasonic results obtained have shown reduction in thermal degradation and improvement in oxidation stability of antioxidant loaded oil in comparison to base oil. Hence, it can be recommended that sunflower oil with 200 ppm BHA can be used for frying without adverse effect on physical properties. The ultrasonic velocity can be used for assessment of stability of frying oil. PMID:26788006

  15. Isobaric (vapour + liquid) equilibria of binary systems containing butyl acetate for the separation of methoxy aromatic compounds (anisole and guaiacol) from biomass fast pyrolysis oil

    International Nuclear Information System (INIS)

    Highlights: • The two binary systems related to pyrolysis oil have been reported. • The VLE data were correlated well by the activity coefficient models. • The UNIFAC (Do) model was applied to predict the experimental VLE data. • The interaction parameter (ACOCH3–CH3COO) was obtained and proved to be reliable. • The obtained interaction parameters by NRTL model were used in the separation process design for the ternary mixture. - Abstract: Developing value-added chemicals from pyrolysis oil has been gaining increasing attention. Thus effective separation and purification of the pyrolysis oil are important and the phase equilibrium data are essential for the design and simulation of the processes. In this study, isobaric vapour–liquid equilibrium (VLE) for the two binary mixtures (butyl acetate + anisole) and (butyl acetate + guaiacol) have been determined at 101.33 kPa, a knowledge of which is essential for the separation of methoxy aromatic compounds (anisole and guaiacol) from biomass fast pyrolysis oil using butyl acetate as a solvent. All the experimental values were confirmed to be thermodynamically consistent using the van Ness method. The NRTL, UNIQUAC, and Wilson activity coefficient models were applied to regress the experimental values. The calculated results agreed well with the measured values. Furthermore, the results were calculated by the UNIFAC (Do) method (modified UNIFAC model) in which aromatic methoxyl is treated as a group (ACOCH3). The new interaction parameter (ACOCH3–CH3COO) was obtained and proved to be reliable. Based on the preceding results, a feasible separation process for the ternary mixture (butyl acetate + anisole + guaiacol) has been designed to obtain the required products

  16. Separation of boron isotopes at chemical isotopic exchange between, boron trifluoride and its complex with anisole in multitube mass-exchange column

    International Nuclear Information System (INIS)

    The results are given on continuous counterflow two-phase process of boron isotopes 10B and 11B separation at chemical isotopic exchange between gaseous BF3 and its liquid complex with anisole, the process is realized in the module of three packed columns with parallel operation; each of the columns in its bottom part is connected with the others by the common unit of flow reversal (desorber), has the diameter of 78 mm, height of 46.5 m, and is filled with wire spiral-prismatic pack with 3.5·3.5·0.2 mm element

  17. Investigation of the ionization mechanism of polycyclic aromatic hydrocarbons using an ethanol/bromobenzene/chlorobenzene/anisole mixture as a dopant in liquid chromatography/atmospheric pressure photoionization mass spectrometry

    KAUST Repository

    Amad, Maan H.

    2012-09-23

    RATIONALE An ethanol-based multicomponent dopant consisting of ethanol/chlorobenzene/bromobenzene/anisole (98.975:0.1:0.9:0.025, v/v/v/v) has been used as a dopant for atmospheric pressure photoionization (APPI) of polycyclic aromatic hydrocarbons (PAHs). In this study the mechanism of ionization of PAHs assisted by the ethanol-based multicomponent dopant is investigated. METHODS The reactant background cluster ions of the ethanol-based multicomponent dopant observed in the positive ion APPI were studied. These studies were performed to investigate the mechanism behind the generation of a molecular radical cation (M +•) for PAHs by APPI assisted by the ethanol-based multicomponent dopant. Full scan and MS/MS analyses were conducted using an LTQ Orbitrap mass spectrometer. The effect of acidification of the mobile phase on the dopant cluster ion formation was also investigated. RESULTS With the ethanol-based multicomponent dopant, a single type of molecular radical cation M +• was observed for the studied PAHs. The characteristic ion signal of the multicomponent dopant mixture consisted of mainly anisole photoions at m/z 108.05697 and its adduct ions at m/z 124.05188 and 164.07061. The anisole ion response at m/z 108.05697 was stable in the presence of acetonitrile, methanol, water and 0.1% formic acid mobile phase composition. CONCLUSIONS The abundance formation of anisole photoions shows the universality of this multicomponent dopant in ionizing compounds with ionization energy ranging from 7.1-8.2 eV. Since the ionization energy of anisole is 8.2 eV and is lower than those of chlorobenzene (9.07 eV) and bromobenzene (9.0 eV), the mechanism of formation of anisole photoions even with its very minute amounts was not only governed by its photoionization by the krypton lamp photon energy (10.0 eV and 10.6 eV), but also by charge transfer from bromobenzene and chlorobenzene radical cations. PAH molecules were mainly ionized by charge transfer reaction from

  18. 355nm激光作用下苯甲醚的多光子电离质谱研究%Study on multiphoton ionization mass spectrum of anisole at 355 nm

    Institute of Scientific and Technical Information of China (English)

    杨建春; 孔祥和; 刘妮

    2011-01-01

    The anisole is studied by using multiphoton ionization technique and time-of-flight mass spectrum (TOF-MS) under the radiation of the 355 nm laser.The experiment shows that the multiphoton ionization mechanism of anisole is parent molecule ionization-dissociation model.At the same time, the two possible channels of parent ion are analyzed, but the channel of methyl removed is the major channel with the increase of laser power.The geometric structures of the ground states of anisole and anisole cation also are optimized at HF/6-31G(d) level, furthermore, the stable structure is acquired.In addition, we also calculate the energy of anisole and its main fragment ions.At last, by comparing difference of the dissociation energy of anisole and its main fragment ions of the two channels, the theoretical resuits further demonstrate, in the experiment, that the main dissociation channel of anisole molecular will be formed.%在355 nm激光作用下,利用多光子电离技术结合飞行时间质谱(TOF-MS)对苯甲醚分子进行了研究.实验结果表明苯甲醚分子的多光子电离机制属于母体分子电离-解离模型.通过对主要碎片离子的可能形成过程的讨论,得出该波长下母体分子离子解离的主要有两种通道,但是随激光能量的增强,甲基移除通道逐步占据优势成为主要通道.应用高斯软件采用HF/6-31G(d)方法对苯甲醚分子和苯甲醚阳离子基态的几何构型进行优化得到其稳定构型,并计算了苯甲醚分子离子及其初级解离产物的能量.比较两条通道的碎片离子能量的变化,理论验证了实验中苯甲醚分子主要解离通道的合理性.

  19. Volumetric and ultrasonic behaviour of binary mixtures of 1-nonanol with o-cresol, m-cresol, p-cresol and anisole at T = (293.15 and 313.15) K

    International Nuclear Information System (INIS)

    Densities, ρ, and speeds of sound, u, of binary liquid mixtures of 1-nonanol with o-cresol, m-cresol, p-cresol and anisole have been measured over the entire range of composition at T = (293.15 and 313.15) K and at atmospheric pressure. Using these data, the excess molar volume, VE, molar free volume, Vf, parameters related to space-filling ability, Vf/V, non-linearity parameters, B/A, isentropic compressibility, κS, molar isentropic compressibility, KS,m, deviation of molar isentropic compressibility, KS,mE, deviations of the speed of sound, uD, and limiting excess partial molar volume, V-barm,iE,0, and isentropic compressibility, K-barm,iE,0, have been calculated. The calculated excess and deviation functions have been fitted to the Redlich-Kister polynomial equations and the results analyzed in terms of molecular interactions and structural effects.

  20. Volumetric and ultrasonic behaviour of binary mixtures of 1-nonanol with o-cresol, m-cresol, p-cresol and anisole at T = (293.15 and 313.15) K

    Energy Technology Data Exchange (ETDEWEB)

    Bhatia, Subhash C., E-mail: bhatiasc2@rediffmail.co [Department of Chemistry, Kurukshetra University, Kurukshetra 136 119 (India); Rani, Ruman, E-mail: rumanjangra58@gmail.co [Department of Chemistry, Kurukshetra University, Kurukshetra 136 119 (India); Bhatia, Rachna, E-mail: bhatiarachna_3@rediffmail.co [Department of Chemistry, Kurukshetra University, Kurukshetra 136 119 (India); Anand, Hardeep [Department of Chemistry, Kurukshetra University, Kurukshetra 136 119 (India)

    2011-03-15

    Densities, {rho}, and speeds of sound, u, of binary liquid mixtures of 1-nonanol with o-cresol, m-cresol, p-cresol and anisole have been measured over the entire range of composition at T = (293.15 and 313.15) K and at atmospheric pressure. Using these data, the excess molar volume, V{sup E}, molar free volume, V{sub f}, parameters related to space-filling ability, V{sub f}/V, non-linearity parameters, B/A, isentropic compressibility, {kappa}{sub S}, molar isentropic compressibility, K{sub S,m}, deviation of molar isentropic compressibility, K{sub S,m}{sup E}, deviations of the speed of sound, u{sup D}, and limiting excess partial molar volume, V-bar{sub m,i}{sup E,0}, and isentropic compressibility, K-bar{sub m,i}{sup E,0}, have been calculated. The calculated excess and deviation functions have been fitted to the Redlich-Kister polynomial equations and the results analyzed in terms of molecular interactions and structural effects.

  1. 4-Bromo­seleno­anisole

    OpenAIRE

    Sørensen, Henning Osholm; Stuhr-Hansen, Nicolai

    2009-01-01

    The title compound, 1-bromo-4-methyl­seleno­benzene, C7H7BrSe, was prepared by methyl­ation of 4-bromo­seleno­phenolate with methyl iodide, and crystals suitable for structure determination were obtained by sublimation. The mol­ecule is essentially planar; the Se—Me bond is rotated by only 2.59 (19)° out of the least-squares plane of the benzene ring. The most pronounced intermolecular interactions are two hydrogen bonds of the type C—H⋯π, which determine a herring-bone pattern in the crystal...

  2. Benzoylation of anisole catalyzed by Ga/SBA-15 supported on carbon nanofibers composite

    OpenAIRE

    EL BERRICHI, F. Z.; Pham-Huu, C.; CHERIF, L.; Louis, B; M. J.; Ledoux

    2011-01-01

    Carbon nanofiber composite (C-NFC) shows several advantages compared to the conventional supports which are usually employed in catalysis such as alumina, silica or activated charcoal. In this present work we have developed a new hybrid catalyst consisting of SBA-15 supported on C-NFC for the benzoylation reaction. The structured materials allow an important improvement of the reaction hydrodynamics and favor the mass transfer between the active phase and the reactants, especially in the liqu...

  3. Synthesis of Aliphatic Sulfur Pentafluorides by Oxidation of SF5-Containing Anisole, Phenols, and Anilines

    Czech Academy of Sciences Publication Activity Database

    Vida, Norbert; Pastýříková, Tereza; Klepetářová, Blanka; Beier, Petr

    2014-01-01

    Roč. 79, č. 18 (2014), s. 8906-8911. ISSN 0022-3263 R&D Projects: GA ČR GAP207/12/0072 Institutional support: RVO:61388963 Keywords : SF5 * pentafluorosulfanyl Subject RIV: CC - Organic Chemistry Impact factor: 4.721, year: 2014

  4. Effect of. cap alpha. -tocopherol, butylated-hydroxytoluene and hydroxy-anisole on the activation and binding of aflatoxin B/sub 1/ to macromolecules

    Energy Technology Data Exchange (ETDEWEB)

    Ch' ih, J.J.; Biedrzycka, D.; Devlin, T.M.

    1987-05-01

    The anti-oxidants, ..cap alpha..-tocopherol(TPA), butylated-hydroxy-toluene(BHT) and hydroxyanisole(BHA) inhibit the carcinogenic and toxic effects of a variety of chemical compounds, their effect on aflatoxin B/sub 1/ (AFB/sub 1/) activation and binding was examined utilizing rat liver microsomes and cells. With a NADPH generating system, oxygen, microsomes, (/sup 3/H)-AFB/sub 1/, 2.2 pmoles/h/mg protein was activated and bound to macromolecules. In hepatocytes, 3.4 and 1.4 pmoles of AFB/sub 1/ per 10/sup 6/ cells were taken up and bound to macromolecules, whereas the nucleic acid fraction contained 0.19 pmoles of bound AFB/sub 1/. Moderate decreases of AFB/sub 1/ activation and binding were observed when TPA was present in both cell-free and hepatocytes systems. Only in hepatocytes, BHT inhibited the AFB/sub 1/ uptake and binding to nucleic acids. BHA, however, inhibited microsomal activation of AFB/sub 1/ by 73%; maximum inhibition was reached at 1 mM. AFB/sub 1/ uptake, and binding to nucleic acids were inhibited by 65% and 79% by BHA. GSH-transferase activity of cells treated with these agents was not altered. The effect of BHA at various concentrations on AFB activation was compared with cytochrome P-450 inhibitors; the ED/sub 50/ of SKF 525A, BHA and metyrapone was 9 uM, 80 uM and 380 uM respectively. The data suggest that TPA, BHA and BHT exert their effect by different mechanisms.

  5. Short-term pathological and proliferative effects of butylated hydroxy anisole and other phenolic antioxidants in the forestomach of Fischer 344 rats

    International Nuclear Information System (INIS)

    Food grade butylated hydroxyanisole (BHA) when incorporated in the diet and fed to male Fischer 344 rats for 9 or 27 days induced proliferative squamous epithelial changes in the lesser curvature of the forestomach proximate to the plandular stomach. These changes were assessed histopathologically and by (methyl-3H) thymidine radioautography. It was shown that BHA mixed dry into powdered diet, incorporated into the diet in corn oil, or in a pelleted diet, induced similar effects. When levels of 2%, 1%, 0.5%, 0.25%, 0.1% and BHA were incorporated in rat diet for 9 days, the proliferative effect appeared to show a no effect level at 0.25% based on the (methyl-3H) thymidine-labelling index. Other food use antioxidants, namely butylated hydroxytoluene or tertiary butylhydroquinone, induced a lesser reponse than BHA at the maximum dose employed in the study. Propyl gallate was without effect. Propyl-4-hydroxybenzoate, a food use phenol, on the other hand, induced a less pronounced response that BHA but was more effective than the other antioxidants. Because increased cellular proliferation often provides an optimal milieu for tumor formation, it is suggested that these observations may be relevant to rat forestomach tumors induced by BHA (author)

  6. Binding Energies of the pi-Stacked Anisole Dimer: New Molecular Beam-Laser Spectroscopy Experiments and CCSD(T) Calculations

    Czech Academy of Sciences Publication Activity Database

    Řezáč, Jan; Nachtigallová, Dana; Mazzoni, F.; Pasquini, M.; Pietraperzia, G.; Becucci, M.; Müller-Dethlefs, K.; Hobza, Pavel

    2015-01-01

    Roč. 21, č. 18 (2015), s. 6740-6746. ISSN 0947-6539 R&D Projects: GA ČR GBP208/12/G016 Grant ostatní: GA MŠk(CZ) ED2.1.00/03.0058 Institutional support: RVO:61388963 Keywords : binding energy * noncovalent interactions * pi stacking * laser spectroscopy * CCSD(T) calculations Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 5.731, year: 2014

  7. 75 FR 57945 - Atonik and Verbenone, Registration Review Proposed Decisions; Notice of Availability

    Science.gov (United States)

    2010-09-23

    ..., verbenone and 4-allyl anisole. Verbenone is a terpene that acts as an anti-aggregation pheromone in... southern pine beetle Dendroctonus frontalis. 4-allyl anisole is an alkenylbenzene compound that is...

  8. Structure and energetics of the anisole-Ar-n (n=1, 2, 3) complexes: high-resolution resonant two-photon and threshold ionization experiments, and quantum chemical calculations

    Czech Academy of Sciences Publication Activity Database

    Mazzoni, F.; Becucci, M.; Řezáč, Jan; Nachtigallová, Dana; Michels, F.; Hobza, Pavel; Müller-Dethlefs, K.

    2015-01-01

    Roč. 17, č. 19 (2015), s. 12530-12537. ISSN 1463-9076 R&D Projects: GA ČR GBP208/12/G016 Grant ostatní: GA MŠk(CZ) ED2.1.00/03.0058 Institutional support: RVO:61388963 Keywords : intermolecular interactions * noncovalent interactions * van der Waals Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.493, year: 2014

  9. 反相高效液相色谱法测定化妆品中的抗氧化剂丁基羟基茴香醚和二丁基羟基甲苯%Determination of Antioxidant Butyl-Hydroxyl Anisole and 2,6-Dibutyl-Hydroxyl Toluene in Cosmetics with Reverse-Phase High Performance Liquid Chromatograp

    Institute of Scientific and Technical Information of China (English)

    陈会明; 王超

    2004-01-01

    为了保证化妆品质量,要添加一定量的抗氧化剂。但抗氧化剂过量,会损害人体健康。合格食品的抗氧化剂的添加量必须符合国家卫生标准。卫生部对化妆品中丁基羟基茴香醚(BHA)和二丁基羟基甲苯(BHT)的最大限量要求均为0.15%,但化妆品中BHA和BHT尚无行业及国家卫生检验标准。食品中抗氧化剂的测定一直沿用薄层法、比色法和气相

  10. EFSA ; Scientific Opinion on Flavouring Group Evaluation 59, Revision 1 (FGE.59Rev1): Consideration of aliphatic and aromatic ethers evaluated by JECFA (61st meeting and 63rd meeting) structurally related to aliphatic, alicyclic and aromatic ethers including anisole derivatives evaluated by EFSA in FGE.23 Rev2 (2010)

    DEFF Research Database (Denmark)

    Larsen, John Christian; Nørby, Karin Kristiane; Beltoft, Vibe Meister;

    The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to consider evaluations of flavouring substances assessed since 2000 by the Joint FAO/WHO Expert Committee on Food Additives (the JECFA), and to decide whether further......, “No safety concern at estimated levels of intake as flavouring substances” based on the MSDI approach. Besides the safety assessment of these flavouring substances, the specifications for the materials of commerce have also been considered and for two substances, are information on the composition of...

  11. EFSA Panel on food contact materials, enzymes, flavourings and processing aids (CEF); Scientific Opinion on Flavouring Group Evaluation 23, Revision 2 (FGE.23Rev2): Aliphatic, alicyclic and aromatic ethers including anisole derivatives from chemical groups 15, 16, 22, 26 and 30

    DEFF Research Database (Denmark)

    Larsen, John Christian; Nørby, Karin Kristiane; Beltoft, Vibe Meister;

    ether, three are alicyclic hydrocarbons with an ether side chain, two are ethers containing a benzene moiety, eight are phenol ethers and one is a naphthol ether. Five of the 19 candidate substances possess one or more chiral centres and three can exist as geometrical isomers. For one substance [FL...... enable the Panel to make a more realistic estimate of the intakes of the flavouring substances, the Panel has decided also to perform an estimate of the daily intakes per person using a “modified Theoretical Added Maximum Daily Intake” (mTAMDI) approach based on the normal use levels reported by Industry...... levels. According to the default MSDI approach, the 19 flavouring substances in this group have intakes in Europe from 0.011 to 49 micrograms/capita/day, which are below the threshold of concern value for structural class I of 1800 micrograms/person/day, for structural class II of 540 micrograms/person...

  12. A QSRR Study on the Relative Retention Time of Halogenated Methyl-phenyl Ethers

    Institute of Scientific and Technical Information of China (English)

    XU Hui-Ying; YU Qing-Sen; ZOU Jian-Wei; WANG Yan-Hua; WANG Hong-Qing; CHEN Xue-Song

    2006-01-01

    Halogenated methyl-phenyl ethers (anisoles) are ubiquitous organic compounds in the environment. In the present study, geometrical optimization and electrostatic potential calculations have been performed for 42 halogenated anisoles at the HF/6-31 G* level. A number of statistically based parameters have been obtained. By multiple regression method, linear relationships between the gas-chromatographic relative retention time (RRT) and structural descriptors have been established for the training set of 32 halogenated anisoles. The result showed that the parameters derived from electrostatic potentials (ESPs) together with the molecular volume (Vmc) could be well used to express the quantitative structure-RRT relationships of halogenated anisoles. The best two-variable regression model gives a correlation coefficient of 0.980 and a standard deviation of 0.07, and the leave-one-out cross-validated correlation coefficient is 0.975. The goodness of the model has been further validated through exploring the predictive power for the testing set of 10 halogenated anisoles.

  13. Alkyl aryl ethers in lignite solubilization 1. Study of the process

    Energy Technology Data Exchange (ETDEWEB)

    Mastral, A.M.; Cebolla, V.L.; Gavilan, J.M.

    1984-10-01

    The chemistry of solubilization of a lignite has been investigated with anisole, 3-methyl anisole and 1,3dimethoxybenzene catalysed by SbCl/sub 3/, ZnCl/sub 2/, AlCl/sub 3/ and BF/sub 3/ as boron trifluoride etherate, at atmospheric pressure and temperatures <220/sup 0/C. 60% of lignite was solubilized in a toluene-ethanol azeotropic mixture. During the process, the solvent is incorporated as an alkylated substratum. The yield increased with activity of the aromatic ether ring and catalyst acidity.

  14. Alkyl aryl ethers in lignite solubilization. 1. Study of the process

    Energy Technology Data Exchange (ETDEWEB)

    Mastral, A.M.; Cebolla, V.L.; Gavilan, J.M.

    1984-10-01

    The chemistry of solubilization of a lignite has been investigated with anisole, 3-methyl anisole and 13-dimethoxybenzene catalysed by SbCl/sub 3/, ZnCl/sub 2/, AlCl/sub 3/ and BF/sub 3/ as boron trifluoride etherate, at atmospheric pressure and temperatures <220 C. 60% of lignite was solubilized in a toluene-ethanol azeotropic mixture. During the process, the solvent is incorporated as an alkylated substratum. The yield increased with activity of the aromatic ether ring and catalyst acidity. 14 references.

  15. Iodine-catalyzed thiolation of electron-rich aromatics using sulfonyl hydrazides as sulfenylation reagents.

    Science.gov (United States)

    Zhao, Xia; Li, Tianjiao; Zhang, Lipeng; Lu, Kui

    2016-01-21

    Iodine-catalyzed thiolation of electron-rich aromatics, including substituted anisole, thioanisole, phenol, toluene, and naphthalene, using sulfonyl hydrazides as sulfenylation reagents was carried out. Sulfonothioates, the products of decomposition of sulfonyl hydrazides in the presence of iodine, are proposed as the major sulfenylation species in this transformation. PMID:26645483

  16. Processing of C60 thin films by Matrix-Assisted Pulsed Laser Evaporation (MAPLE)

    DEFF Research Database (Denmark)

    Canulescu, Stela; Schou, Jørgen; Fæster, Søren

    2011-01-01

    Thin films of fullerenes (C60) were deposited onto silicon using matrix-assisted pulsed laser evaporation (MAPLE). The deposition was carried out from a frozen homogeneous dilute solution of C60 in anisole (0.67 wt%), and over a broad range of laser fluences, from 0.15 J/cm2 up to 3.9 J/cm2. MAPL...

  17. Bis-perfluoroalkylation of aromatic compounds with sodium perfluoroalkanesulfinates

    Institute of Scientific and Technical Information of China (English)

    LIU, Jin-Tao(刘金涛); LU, He-Jun(吕贺军)

    2000-01-01

    Bis-perfluoroalkylation of aromatic compounds such as dimethoxybenzenes (2,4,6), anisole (8), pyridine (10) and quinoline (13) was accomplished by reaction with excess sodium perfluoroalkanesulfinates, RFSO2Na (1), in the presence of Mn(OAc)3·2H2O under mild conditions. The reaction provides a facile method for the synthesis of bis-perfluoroalkylated aromatic compounds.

  18. Confirming the existence of π-allyl-palladium intermediates during the reaction of meta photocycloadducts with palladium(ii) compounds

    OpenAIRE

    Penkett, Clive S; Brann, Paul J; Woolford, Jason A.; Kahan, Rachel J

    2013-01-01

    The transient existence of π-allyl-palladium intermediates formed by the reaction of Pd(OAc)2 and anisole-derived meta photocycloadducts has been demonstrated using NMR techniques. The intermediates tended to be short-lived and underwent rapid reductive elimination of palladium metal to form allylic acetates, however this degradation process could be delayed by changing the reaction solvent from acetonitrile to chloroform.

  19. Aromatic fluorine compounds. VIII. Plant growth regulators and intermediates

    Science.gov (United States)

    Finger, G.C.; Gortatowski, M.J.; Shiley, R.H.; White, R.H.

    1959-01-01

    The preparation and properties of 41 fluorophenoxyacetic acids, 4 fluorophenoxypropionic acids, 2 fluorobenzoic acids, several indole derivatives, and a number of miscellaneous compounds are described. Data are given for many intermediates such as new fluorinated phenols, anisoles, anilines and nitrobenzenes. Most of the subject compounds are related to a number of well-known herbicides or plant growth regulators such as 2,4-D, 2,4,5-T and others.

  20. Synthesis and reactivity of aliphatic sulfur pentafluorides from substituted (pentafluorosulfanyl)benzenes

    OpenAIRE

    Vida, Norbert; Václavík, Jiří; Beier, Petr

    2016-01-01

    Oxidation of 3- and 4-pentafluorosulfanyl-substituted anisoles and phenols with hydrogen peroxide and sulfuric acid provided a mixture of SF5-substituted muconolactone, maleic, and succinic acids. A plausible mechanism for the formation of the aliphatic SF5 compounds was presented and their chemical reactivity was investigated. SF5-substituted para-benzoquinone was synthesized; its oxidation led to an improved yield of 2-(pentafluorosulfanyl)maleic acid. The reaction of SF5-substituted maleic...

  1. AC – AC Converters for UPS

    Directory of Open Access Journals (Sweden)

    Rusalin Lucian R. Păun

    2008-05-01

    Full Text Available This paper propose a new control technique forsingle – phase AC – AC converters used for a on-line UPSwith a good dynamic response, a reduced-partscomponents, a good output characteristic, a good powerfactorcorrection(PFC. This converter no needs anisolation transformer. A power factor correction rectifierand an inverter with the proposed control scheme has beendesigned and simulated using Caspoc2007, validating theconcept.

  2. Multicomponent mixed dopant optimization for rapid screening of polycyclic aromatic hydrocarbons using ultra high performance liquid chromatography coupled to atmospheric pressure photoionization high-resolution mass spectrometry

    KAUST Repository

    Sioud, Salim

    2012-05-04

    RATIONALE To enhance the ionization efficiencies in atmospheric pressure photoionization mass spectrometry a dopant with favorable ionization energy such as chlorobenzene is typically used. These dopants are typically toxic and difficult to mix with water-soluble organic solvents. In order to achieve a more efficient and less toxic dopant, a multicomponent mixed dopant was explored. METHODS A multicomponent mixed dopant for non-targeted rapid screening of polycyclic aromatic hydrocarbons (PAHs) was developed and optimized using ultra high performance liquid chromatography (UPLC) coupled to atmospheric pressure photoionization high-resolution mass spectrometry. Various single and multicomponent mixed dopants consisting of ethanol, chlorobenzene, bromobenzene, anisole and toluene were evaluated. RESULTS Fourteen out of eighteen PAHs were successfully separated and detected at low pg/μL levels within 5 min with high mass accuracy ≤4 ppm. The optimal mixed multicomponent dopant consisted of ethanol/chlorobenzene/bromobenzene/anisole (98.975:0.1:0.9:0.025, v/v %) and it improved the limit of detection (LOD) by 2- to 10-fold for the tested PAHs compared to those obtained with pure chlorobenzene. CONCLUSIONS A novel multicomponent dopant that contains 99% ethanol and 1% mixture of chlorobenzene, bromobenzene and anisole was found to be an effective dopant mixture to ionize PAHs. The developed UPLC multicomponent dopant assisted atmospheric pressure photoionization high-resolution mass spectrometry offered a rapid non targeted screening method for detecting the PAHs at low pg/;μL levels within a 5 min run time with high mass accuracy a;circ4 ppm. Copyright © 2012 John Wiley & Sons, Ltd.

  3. Femtosecond fabrication of waveguide-like micro-structures in a photorefractive polymer

    Institute of Scientific and Technical Information of China (English)

    Min Gu; Tom Rodgers; Daniel Day

    2003-01-01

    In this letter, we report on, for the first time, the successful femtosecond micro-fabrication of continu-ous waveguide-like channels in the photorefractive polymer consisting of the nonlinear chromophore 2,5-dimethyl-4-(p-nitrophenylazo)anisole (DMNPAA), the photosensitive compound 2,4,7-trinitro-9-flourenone(TNF), and the plasticiser N-ethylcarbazole (ECZ) all doped in the polymer matrix poly(methyl methacry-late) (PMMA). These channels are caused by the change in refractive index as a result of the localisedheating of the polymer and therefore have an important potential for micro-photonic devices in future.

  4. Effects of pentachlorophenol and some of its known and possible metabolites on different species of bacteria.

    OpenAIRE

    Ruckdeschel, G; Renner, G; Schwarz, K.

    1987-01-01

    The antibacterial activity of pentachlorophenol and 35 of its known or possible metabolites against 30 different species of bacteria was tested. In comparison with pentachlorophenol, no increase of inhibitory activity was found for any of the chlorinated anisoles tested (except for pentachloroanisole against Streptomyces spp.), 2-chlorophenol, 2,6-dichlorophenol, 2,3,6- and 2,4,6-trichlorophenol, 2,3,5,6-tetrachlorophenol, tetrachloro-1,4- and -1,3-benzenediol (except for the 1,3-isomer again...

  5. Thermodynamics of Host–Guest Interactions between Fullerenes and a Buckycatcher

    OpenAIRE

    Le, Vu H; Yanney, Michael; McGuire, Matthew; Sygula, Andrzej; Lewis, Edwin A.

    2014-01-01

    1H NMR and isothermal titration calorimetry (ITC) experiments were employed to obtain reliable thermodynamic data for the formation of the 1:1 inclusion complexes of fullerenes C60 and C70 with the buckycatcher (C60H28). NMR measurements were done in toluene-d 8 and chlorobenzene-d 5 at 288, 298, and 308 K, while the ITC titrations were performed in toluene, chlorobenzene, o-dichlorobenzene, anisole, and 1,1,2,2-tetrachloroethane at temperatures from 278 to 323 K. The association constants, K...

  6. EFFECT OF MORINGA OLEIFERA MARINADE ON PROXIMATE COMPOSITION AND SENSORY CHARACTERISTICS OF SMOKE-DRIED AFRICAN CATFISH (CLARIAS GARIEPINUS)

    OpenAIRE

    Kazeem Dauda Adeyemi; Aminat Mustapha Ahmed El-Imam; Ayotunde Oluwatunbo Olorunsanya; Foluke Eunice Sola-ojo; Kehinde Mathias Okukpe; Olusegun Oyeshina Dosunmu; Rafiat Morolayo Shittu; John Tolulope Idris

    2013-01-01

    The study assessed the effect of Moringa oleifera marinade on chemical composition and organoleptic properties of smoke-dried catfish in a 6x8 factorial experiment. The experimental treatments are the control, 1, 2 and 3% (w/v) Moringa oleifera Marinade (MOM), 5% brine and 0.2% Butylated Hydroxyl Anisole (BHA) (w/v) solutions. Ninety fishes of average weight of 230±8 g were gutted, washed and randomly assigned to the treatments. Thereafter, the fishes were soaked in the treatments for 2 hours...

  7. Matrix Assisted Pulsed Laser Evaporation for growth of fullerene thin films

    DEFF Research Database (Denmark)

    Canulescu, Stela; Schou, Jørgen; Fæster Nielsen, Søren

    C60 fullerene thin films of average thickness of more than 100 nm can be produced in vacuum by matrix-assisted pulsed laser evaporation (MAPLE). A 355 nm Nd:YAG laser was directed onto a frozen target of anisole with a concentration of 0.67 wt% C60. At laser fluences below 1.5 J/cm2, a dominant...... fluences, are caused by ejection of large matrix-fullerene liquid droplets into the gas-phase and subsequent deposition. At similar laser energies, but using an unfocused laser beam, MAPLE favours evaporation of matrix and organic molecules, resulting in production of films with smooth surfaces and minimal...

  8. Growth of thin fullerene films by matrix assisted pulsed laser evaporation

    DEFF Research Database (Denmark)

    Canulescu, Stela; Schou, Jørgen; Fæster, Søren

    C60 fullerene thin films of average thickness of more than 100 nm on silicon substrates can be produced in vacuum by matrix-assisted pulsed laser evaporation (MAPLE). A 355 nm Nd:YAG laser was directed onto a frozen target of anisole with a concentration of 0.67 wt% C60. At laser fluences below 1......, observed over a wide range of laser fluences, are caused by ejection of large matrix-fullerene liquid droplets into the gas-phase and subsequent deposition. At similar laser energies, but using an unfocused laser beam, MAPLE favours evaporation of matrix and organic molecules, resulting in films with...

  9. Studies on Excess Volume, Viscosity, and Speed of Sound of Binary Mixtures of Methyl Benzoate in Ethers at T=(303.15,308.15, and 313.15) K

    OpenAIRE

    Rathnam, M. V.; Ambavadekar, Devappa R.; Nandini, M.

    2013-01-01

    Densities, viscosities, and speed of sound have been determined at T = (303.15, 308.15, and 313.15) K for the binary mixtures of methyl benzoate with tetrahydrofuran, 1,4-dioxane, anisole, and butyl vinyl ether over the entire range of composition. Using these measured values, excess volume VE, deviation in viscosities Δη, excess Gibb’s free energy of activation for viscous flow ΔG*E, and deviation in isentropic compressibility Δks have been calculated. These calculated binary data have been...

  10. Synthesis of a tritiated human growth hormone releasing peptide

    International Nuclear Information System (INIS)

    Tritium-labeled growth hormone releasing peptide His-D-Trp-Ala-Trp-D-Phe-Lys-NH2 was synthesized by tritium-halogen exchange on the precursor His-5,7-Br2-D-Trp-Ala-Trp-D-Phe-Lys-NH2. The radiolabeled peptide had a specific activity of 29 Ci/mmol and a radiochemical purity of 95%. The tritium label was shown by 3H NMR to be located mostly at the expected 5,7-positions of the indole nucleus in the D-Trp residue. The dibromopeptide was prepared by solid-phase peptide synthesis, employing racemic 5,7-Br2-Trp as a building block and separation of the resulting epimeric mixture by HPLC. 5,7-Br2-Trp was prepared by a five-step sequence beginning with 2,4-dibromoaniline. The use of anisole as an additive in the HF resin/peptide cleavage was rejected because anisole was found to undergo electrophilic substitution of the dibromoindole nucleus; a modified HF deprotection/cleavage procedure was developed and used instead. (au) (17 refs.)

  11. Alkyl aryl ethers in lignite solubilization. 2. Analysis of oil fractions

    Energy Technology Data Exchange (ETDEWEB)

    Mastral, A.M.; Cebolla, V.L.; Gavilan, J.M.

    1985-03-01

    The FT-I.R. and /sup 1/H N.M.R. spectroscopic analyses of oils or maltenes from a Spanish lignite (Utrillas, Teruel), are reported. These oils were obtained by depolymerization with alkyl aromatic ethers (anisole, 3-methyl anisole and 1,3-dimethoxybenzene) catalyzed by Lewis acids ZnCl/sub 2/, AlCl/sub 3/, SbCl/sub 3/ and BF/sub 3/ (as boron trifluoride etherate), at atmospheric pressure and temperatures <220 C. Bands due to aromatic ethers in the I.R. and N.M.R. spectra of the oils obtained by depolymerization indicate solvent incorporation. Oils obtained by direct lignite extraction showed 25% aromatic H and some H (approximately 3%) without OH groups. These appeared in some oils obtained by depolymerization with AlCl/sub 3/ and were due to secondary reactions with the aromatic extract. Oils derived from processes with good yields showed increases in aromaticity. The extent of substitution of aromatic rings in oils obtained by depolymerization was less than for oils directly extracted. All the oils studied show a low degree of condensation. 15 references.

  12. Alkyl aryl ethers in lignite solubilization

    Energy Technology Data Exchange (ETDEWEB)

    Mustral, A.M.; Cebolla, V.L.; Gavilan, J.M.

    1985-03-01

    The FT-I.R. and /sup 1/H N.M.R. spectroscopic analyses of oils or maltenes from a Spanish lignite (Utrillas, Teruel), are reported. These oils were obtained by depolymerization with alkyl aromatic ethers (anisole, 3-methyl anisole and 1,3-dimethoxybenzene) catalyzed by Lewis acids ZnCl/sub 2/, AlCl/sub 3/, SbCl/sub 3/ and BF/sub 3/ (as boron trifluoride etherate), at atmospheric pressure and temperatures <220/sup 0/C. Bands due to aromatic ethers in the I.R. and N.M.R. spectra of the oils obtained by depolymerization indicate solvent incorporation. Oils obtained by direct lignite extraction showed 25% aromatic H and some H /sub i/ (approx. = 3%) without OH groups. These appeared in some oils obtained by depolymerization with AlCl/sub 3/ and were due to secondary reactions with the aromatic extract. Oils derived from processes with good yields showed increases in aromaticity. The extent of substitution of aromatic rings in oils obtained by depolymerization was less than for oils directly extracted. All the oils studied show a low degree of condensation.

  13. Dynamic interactions between poly(3-hexylthiophene) and single-walled carbon nanotubes in marginal solvent.

    Science.gov (United States)

    Luo, Yanqi; Santos, Franceska A; Wagner, Taylor W; Tsoi, Eric; Zhang, Shanju

    2014-06-01

    Interfacial interactions between conjugated polymers and carbon nanotubes are pivotal in determining the device performance of nanotube-based polymer electronic devices. Here, we report on interfacial structures and crystallization kinetics of poly(3-hexylthiophene) (P3HT) in the presence of single-walled carbon nanotubes (SWNTs) in anisole by means of transmission electron microscope (TEM) and ultraviolet-visible (UV-vis) absorption spectroscopy. Confined on SWNT surfaces, the P3HT forms nanofibril crystals perpendicular to the long axis of SWNTs. The equilibrium dissolution temperature of the P3HT crystals in anisole is determined to be 381 ± 10 K according to the Hoffman-Weeks extrapolation approach. Upon cooling, the polymer solution spontaneously undergoes a time-dependent chromism. Various kinetics factors such as crystallization temperature, concentration, and SWNT loading have been investigated. It is found that the growth rate (G) of the crystals scales with concentration (C) as G ∝ C(1.70±0.16). The Avrami model is utilized to analyze the nucleation mechanism and the Avrami exponents vary between 1.0 and 1.3. The Lauritzen-Hoffman theory is applied to study the chain-folding process. The fold surface free energy is calculated to be (5.28-11.9) × 10(-2) J m(-2). It is evident that the addition of 0.30 wt % SWNTs reduces the fold surface free energy by 55.6%. PMID:24856901

  14. Benchmark thermodynamic properties of methylanisoles: Experimental and theoretical study

    International Nuclear Information System (INIS)

    Highlights: • Thermochemistry of 2-, 3-, and 4-methylanisoles was studied. • Liquid state enthalpies of formation were measured by calorimetry. • Vaporisation enthalpies were derived from by transpiration method. • Ab initio enthalpies of formation are in excellent agreement with experiment. • A new paradigm for obtaining thermochemistry of liquid compounds was suggested. - Abstract: Accurate standard molar enthalpy of formation values in the liquid phase can be obtained by combining high-level quantum chemistry values of gas-phase enthalpies of formation with experimentally determined enthalpies of vaporisation. The procedure is illustrated for 2-, 3-, and 4-methyl-anisoles. Using the W1-F12 and G4 quantum-chemical methods, the gas-phase enthalpies of formation of these compounds at T = 298.15 K were computed. Molar enthalpies of vaporisation for these isomers were measured by the transpiration method. Combining the experimental and the high-level ab initio values, the standard molar enthalpies of formation in the liquid phase for all three isomers were derived and compared with those determined for 2- and 4-methyl-anisoles by using combustion calorimetry

  15. Neurosteroid analysis by gas chromatography–atmospheric pressure photoionization–tandem mass spectrometry

    International Nuclear Information System (INIS)

    Graphical abstract: -- Highlights: •GC is interfaced with APPI–MS/MS using simple, commercially available hardware. •With chlorobenzene as dopant, trimethylsilylated steroids form abundant radical cations with minimal fragmentation in GC–APPI–MS. •The method shows good sensitivity and quantitative performance. •The product ion spectra of the TMS-derivatized steroids are similar to EI spectra. -- Abstract: A new and simple APPI interface employing commercially available hardware is used to combine GC to MS. The feasibility of the method is demonstrated in the analysis of urine samples for neurosteroids as their trimethylsilyl (TMS) derivatives. The effect of different dopants (chlorobenzene, toluene, anisole) on the ionization of the TMS derivatives was investigated. With chlorobenzene, the TMS derivatives produced intense molecular ions with minimal fragmentation, and chlorobenzene was selected as best dopant. Protonated molecules in addition to intense molecular ions were produced with toluene and anisole. The performance of the method was verified in the analysis of human urine samples. Chromatographic performance was good with peak half-widths of 3.6–4.3 s, linearity (r2 > 0.990) was acceptable, limits of detection (LODs) were in the range of 0.01–10 ng mL−1, and repeatability was good with relative standard deviations (rsd%) below 22%. The results show that the method is well suited for the determination of neurosteroids in biological samples

  16. Neurosteroid analysis by gas chromatography–atmospheric pressure photoionization–tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Suominen, Tina; Haapala, Markus; Takala, Anna [Division of Pharmaceutical Chemistry, Faculty of Pharmacy, P.O. Box 56, FI-00014 University of Helsinki (Finland); Ketola, Raimo A. [Hjelt Institute, Department of Forensic Medicine, P.O. Box 40, FI-00014 University of Helsinki (Finland); Kostiainen, Risto, E-mail: Risto.Kostiainen@helsinki.fi [Division of Pharmaceutical Chemistry, Faculty of Pharmacy, P.O. Box 56, FI-00014 University of Helsinki (Finland)

    2013-09-10

    Graphical abstract: -- Highlights: •GC is interfaced with APPI–MS/MS using simple, commercially available hardware. •With chlorobenzene as dopant, trimethylsilylated steroids form abundant radical cations with minimal fragmentation in GC–APPI–MS. •The method shows good sensitivity and quantitative performance. •The product ion spectra of the TMS-derivatized steroids are similar to EI spectra. -- Abstract: A new and simple APPI interface employing commercially available hardware is used to combine GC to MS. The feasibility of the method is demonstrated in the analysis of urine samples for neurosteroids as their trimethylsilyl (TMS) derivatives. The effect of different dopants (chlorobenzene, toluene, anisole) on the ionization of the TMS derivatives was investigated. With chlorobenzene, the TMS derivatives produced intense molecular ions with minimal fragmentation, and chlorobenzene was selected as best dopant. Protonated molecules in addition to intense molecular ions were produced with toluene and anisole. The performance of the method was verified in the analysis of human urine samples. Chromatographic performance was good with peak half-widths of 3.6–4.3 s, linearity (r{sup 2} > 0.990) was acceptable, limits of detection (LODs) were in the range of 0.01–10 ng mL{sup −1}, and repeatability was good with relative standard deviations (rsd%) below 22%. The results show that the method is well suited for the determination of neurosteroids in biological samples.

  17. Synthesis of thiolate-protected silver nanocrystal superlattices from an organometallic precursor and formation of molecular di-n-alkyldisulfide lamellar phases

    International Nuclear Information System (INIS)

    Silver nanocrystal superlattices (NCSs) stabilized by hexadecanethiol have been prepared through reduction of [Ag(hexadecanethiolate)]n, formed in situ by reaction of the organometallic precursor [Ag(C6F5)] and hexadecanethiol. The nanostructures have been characterized by transmission electron microscopy (TEM) and X-ray diffractometry (XRD). Several reaction parameters such as solvent (anisole or toluene), reaction temperature (150 or 120 °C) or silver:thiol ratio (1:1 or 2:1) have been studied. The NCSs are formed by silver nanoparticles which sizes range from 3.7 to 5.1 nm, depending on the reaction conditions. The formation a of lamellar phase of di-n-hexadecyldisulfide by oxidation of the hexadecanethiolate ligands bonded to Ag(I) is detected by XRD.Graphical abstractThiolate-protected silver nanocrystal superlattices (Ag NCSs) have been successfully prepared using an organometallic precursor reacted with hexadecanethiol, in anisole under 3 bars of H2 at 150 °C A di-n-hexadecyl disulfide lamellar phase formed during the reaction has been studied.

  18. Hydrogen bonding in (substituted benzene)·(water)n clusters with n≤4

    International Nuclear Information System (INIS)

    Infrared ion-depletion spectroscopy, a double resonance method combining vibrational predissociation with resonant two-photon ionization (R2PI) spectroscopy, has been applied to study mixed clusters of the type (substituted benzene)·(H2O)n with n≤4. The UV chromophores were p-difluorobenzene, fluorobenzene, benzene, toluene, p-xylene and anisole. From the IR depletion spectra in the region of the OH stretching vibrations it could be shown that the water molecules are attached as subclusters to the chromophores. Size and configuration of the subclusters could be deduced from the IR depletion spectra. In the anisole·(H2O)1and2 complexes the water clusters form an ordinary hydrogen bond to the oxygen atom of the methoxy group. In all other mixed complexes a π-hydrogen bond is formed between one of the free OH groups of a water subcluster and the π-system of the chromophore. According to the strength of this interaction the frequency of the respective absorption band exhibits a characteristic red-shift which could be related to the total atomic charges in the aromatic ring. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  19. Studies on degradation of food additives by irradiation, 1

    International Nuclear Information System (INIS)

    Degradation of butyl hydroxy anisol (BHA) by γ-rays irradiation was studied. 0.5% BHA in ethanol solution was dosed 2.0 M rad γ-ray. As a result, 8 species of degradation products were found by GLC mass spectrometry, and these parent peak's m/e were as follows: 166, 194, 220, 222, 224, 266, 358, 358. Four species of 8 degradation products were separates and these structure were determined to be 3,3'-di-tert-butyl-2,2'-dihydroxy-5, 5'-dimethoxy biphenyl, 2', -3-di-tert-butyl-2-hydroxy-4', 5-dimethoxy biphenyl ether, 2-tert-butyl-hydroquinone and 2-tert-butyl-1, 4-dimethoxy-benzene. (auth.)

  20. Direct milling and casting of polymer-based optical waveguides for improved transparency in the visible range

    DEFF Research Database (Denmark)

    Snakenborg, Detlef; Perozziello, Gerardo; Klank, Henning; Geschke, Oliver; Kutter, Jörg Peter

    2006-01-01

    integrated optical waveguides. Polymethylinethacrylate (PMMA) is dissolved in anisole and 'doped' with styrene-arcylonitrile copolymer to vary the refractive index. The doped PMMA with a higher refractive index is then spin coated onto a PMMA substrate with a lower refractive index to provide waveguide......Polymer waveguides fabricated from photoresist have an inherent high propagation loss in the short visible wavelength range caused by absorption due to the added photosensitizers. We have addressed this problem by development of two novel methods for the fabrication of microfluidic systems with...... properties. Direct micromilling enabled us to fabricate 100 mu m wide optical waveguides. Propagation losses of less than 1 dB cm(-1) could be achieved throughout the entire visual range down to a wavelength of 400 nm. A casting process amenable to high number production of such devices was furthermore...

  1. Use of lycopene as a natural antioxidant in extending the shelf-life of anhydrous cow milk fat.

    Science.gov (United States)

    Siwach, Ruby; Tokas, Jayanti; Seth, Raman

    2016-05-15

    Oxidative rancidity in anhydrous cow milk fat leads to reduction in its shelf life. Use of synthetic antioxidants is prevalent in dairy industry to prevent the development of rancidity. Keeping in view the increasing demand for natural additives, the present study was carried out to explore the potential of lycopene as a natural antioxidant in anhydrous cow milk fat. Lycopene at five different levels (30, 60, 90, 120 and 150ppm) and butylated hydroxyl anisole (200ppm), were incorporated in anhydrous cow milk fat. Potential of lycopene extract to enhance the shelf life of anhydrous cow milk fat was evaluated by measuring Free Fatty Acids, peroxide value, Thiobarbituric Acid value and color value during 12months of storage at ambient conditions (30°C). Lycopene significantly (p<0.05) prevented the development of oxidative rancidity. Lycopene containing samples scored significantly higher in terms of sensory attributes as compared to control. PMID:26776006

  2. Key factor affecting the structural and textural properties of ZSM-5/MCM-41 composite

    Science.gov (United States)

    Boukoussa, Bouhadjar; Aouad, Nafissa; Hamacha, Rachida; Bengueddach, Abdelkader

    2015-03-01

    ZSM-5/MCM-41 micro/mesoporous composite materials were synthesized by the hydrothermal technique with alkali-treated ZSM-5 zeolite as source of silica and aluminum and characterized by various physico-chemical techniques such as X-ray diffraction (XRD), nitrogen sorption at 77 K, transmission electronic microscopy (TEM), FTIR spectroscopy and NH3 temperature programmed desorption (TPD) techniques. The effect of concentration of CTAB in the synthesis of these solids has been investigated, the mesopore volume, surface area and surface acidity decrease with increasing the concentration of CTAB. Increasing the CTAB concentration causes the recrystallization of zeolite ZSM-5 and it disadvantage the formation of mesoporous materials MCM-41. The catalytic activity of ZSM-5/MCM-41 materials has been evaluated in the Friedel-Crafts acylation of anisole with benzoyl chloride as alkylating agent. The results revealed the reaction to be influenced by surface area, pore volume and surface acidity.

  3. Deposition of matrix-free fullerene films with improved morphology by matrix-assisted pulsed laser evaporation (MAPLE)

    DEFF Research Database (Denmark)

    Canulescu, Stela; Schou, Jørgen; Fæster, Søren;

    2013-01-01

    Thin films of C60 were deposited by matrix-assisted pulsed laser evaporation (MAPLE) from a frozen target of anisole with 0.67 wt% C60. Above a fluence of 1.5 J/cm2 the C60 films are strongly non-uniform and are resulting from transfer of matrix-droplets containing fullerenes. At low fluence the...... fullerene molecules in the films are intact, the surface morphology is substantially improved and there are no measurable traces of the matrix molecules in the film. This may indicate a regime of dominant evaporation at low fluence which merges into the MAPLE regime of liquid ejection of the host matrix at...

  4. The Analysis of Orange Oil and the Aqueous Solubility of d-Limonene. Two Complementary Gas Chromatography Experiments

    Science.gov (United States)

    Williams, Kathryn R.; Pierce, Russell E.

    1998-02-01

    The monoterpene d-limonene is determined by gas chromatography using anisole as the internal standard. Unknowns for the orange oil analysis are prepared by diluting commercially available Valencia oil with n-hexane (ca. 2% oil by weight). Students determine the d-limonene content from the GC results and divide by the known d-limonene content of Valencia oil (95.03 %) to obtain the wt% oil in the unknown. In the experiment, students determine the concentration of d--limonene in the head-space vapors above aqueous samples containing varying amounts of d--limonene. The concentration in the vapor levels off at the solubility limit. At the University of Florida, the experiments are performed in the beginning analytical (orange oil analysis) and physical chemistry (solubility determination) laboratories, but they are also applicable to other laboratory courses.

  5. Characterization of safe solvent PMMA resist variables for electron-beam application

    Science.gov (United States)

    Smith, Bruce W.; Eakin, Todd D.; Johnson, Donald W.

    1994-05-01

    Results are presented from a study undertaken to evaluate resist casting solvent composition and molecular weight variation in PMMA for electron beam exposure. PMMA cast in several solvent systems have been evaluated for lithographic performance. Additionally, formulations in chlorobenzene with minor variations in molecular weight have been evaluated for batch-to- batch uniformity. A 10 KeV MEBES electron beam system has been used to study resist sensitivity, contrast, and process latitude. Using a two-factor, three level factorial designed experiment, prebake and development time have been varied as controlled process factors. Samples with varying molecular weights were shown to have wide process latitude. These samples gave comparable performance while their molecular weights varied from 539 K to 614 K, and polydispersity varied from 3.3 to 6.1. Resist samples with chlorobenzene, PGMEA (propylene glycol monomethyl ether acetate), and anisole as the casting solvent resulted in equivalent performance.

  6. ZICOS - New project for neutrinoless double beta decay experiment using zirconium complex in liquid scintillator

    Science.gov (United States)

    Fukuda, Yoshiyuki

    2016-05-01

    A liquid scintillator containing a tetrakis (isopropyl acetoacetato) zirconium has been developed for new project of neutrinoless double beta decay experiment (ZICOS experiment). We have synthesized a tetrakis (isopropyl acetoacetato) zirconium, which have high solubility (over 31.2 wt.%) in anisole. We measured the performance of liquid scintillator containing 10 wt.% concentration of a tetrakis (isopropyl acetoacetato) zirconium, and obtained 48.7 ± 7.1% of the light yield of BC505 and the energy resolution of 4.1 ± 0.6% at 3.35 MeV assuming 40% photo coverage of the photomultiplier, respectively. We also estimated that ZICOS experiment should be sensitive to (mν) Zen using Cherenkov lights.

  7. SYNTHESIS AND CHARACTERIZATION OF A SILICA-SUPPORTED CARBOXYMETHYLCELLULOSE PLATINUM COMPLEX AND ITS CATALYTIC BEHAVIORS FOR HYDROGENATION OF AROMATICS

    Institute of Scientific and Technical Information of China (English)

    TANG Liming; HUANG Meiyu; JIANG Yingyan

    1996-01-01

    A silica-supported carboxymethylcellulose platinum complex (abbreviated as SiO2-CMC-Pt) has been prepared and characterized by XPS. Its catalytic properties for hydrogenation of aromatic compounds were studied. The results showed that this catalyst could catalyze the hydrogenation of phenol, anisol, p-cresol, benzene and toluene to cyclohexanol, cyclohexyl methyl ether, p-methyl cyclohexanol, cyclohexane and methylcyclohexane, respectively in 100% yield at 30℃ and 1 atm. In the hydrogenation of phenol,COO/Pt ratio in SiO2-CMC-Pt has much influence on the initial hydrogenation rate and the selectivity for the intermediate product, cyclohexanone. The highest initial rate and the highest yield of cyclohexanone both occur at COO/Pt ratio of 6. The complex is stable during the reaction and can be used repeatedly.

  8. Iron Arene Salts as Initiators for Thermal Curing of Epoxides by Photo-catalysis

    Institute of Scientific and Technical Information of China (English)

    王涛; 李保山; 于萌; 万平玉

    2005-01-01

    [Cyclopentadien-Fe-naphthalene]BF4(CFN) and [cyclopentadien-Fe-anisole]BF4(CFA) thermal cationic initiators for the curing of epoxide E44 and GGE were investigated. CFN brought out the curing of E44 at 89.1℃ and that of GGE at 148.7℃. However, CFA had much less thermal initiating activity under 300℃.Under UV radiation for short time, the thermal initiating activities of CFN and CFA were enhanced obviously. It was observed that the initiating onset temperature decreased and the evolved heat of the curing increased. Both CFN and CFA can carrv out the polvmerization of E44 and GGE near 85℃ and 112℃ by UV radiation.

  9. Studies on Excess Volume, Viscosity, and Speed of Sound of Binary Mixtures of Methyl Benzoate in Ethers at T=(303.15,308.15, and 313.15 K

    Directory of Open Access Journals (Sweden)

    M. V. Rathnam

    2013-01-01

    Full Text Available Densities, viscosities, and speed of sound have been determined at T = (303.15, 308.15, and 313.15 K for the binary mixtures of methyl benzoate with tetrahydrofuran, 1,4-dioxane, anisole, and butyl vinyl ether over the entire range of composition. Using these measured values, excess volume VE, deviation in viscosities Δη, excess Gibb’s free energy of activation for viscous flow ΔG*E, and deviation in isentropic compressibility Δks have been calculated. These calculated binary data have been fitted to Redlich-Kister equation to determine the appropriate coefficients. The values of excess volume VE and deviation in viscosities Δη are negative over the entire range of composition for all the binary systems at the studied temperatures. The behavior of these parameters with composition of the mixture has been discussed in terms of molecular interactions between the components of liquids.

  10. Synthesis and reactivity of aliphatic sulfur pentafluorides from substituted (pentafluorosulfanyl)benzenes.

    Science.gov (United States)

    Vida, Norbert; Václavík, Jiří; Beier, Petr

    2016-01-01

    Oxidation of 3- and 4-pentafluorosulfanyl-substituted anisoles and phenols with hydrogen peroxide and sulfuric acid provided a mixture of SF5-substituted muconolactone, maleic, and succinic acids. A plausible mechanism for the formation of the aliphatic SF5 compounds was presented and their chemical reactivity was investigated. SF5-substituted para-benzoquinone was synthesized; its oxidation led to an improved yield of 2-(pentafluorosulfanyl)maleic acid. The reaction of SF5-substituted maleic anhydride and para-benzoquinone with cyclopentadiene afforded the Diels-Alder adducts. Decomposition of 3-(pentafluorosulfanyl)muconolactone in acidic, neutral and basic aqueous media was investigated and the decarboxylation of 2-(pentafluorosulfanyl)maleic acid provided 3-(pentafluorosulfanyl)acrylic acid. PMID:26877813

  11. A comparative study between natural and synthetic antioxidants: Evaluation of their performance after incorporation into biscuits.

    Science.gov (United States)

    Caleja, Cristina; Barros, Lillian; Antonio, Amilcar L; Oliveira, M Beatriz P P; Ferreira, Isabel C F R

    2017-02-01

    Currently, the food industry is focused in replacing the use of synthetic by natural antioxidants. The present study focused on the use of fennel and chamomile extracts, rich in phenolic compounds, as natural antioxidants in biscuits and compared their performance with a synthetic antioxidant widely used, the butylated hydroxyl anisole (BHA). The complete nutritional profile, free sugars, fatty acids and antioxidant activity were determined immediately after baking and also after 15, 30, 45 and 60days of storage. The results showed that the incorporation of natural and synthetic additives did not cause significant changes in colour or in nutritional value of biscuits when compared with control samples. Both natural and synthetic additives conferred similar antioxidant activity to the biscuits. Therefore, natural additives are a more convenient solution for consumers who prefer foods "free" from synthetic additives. Additionally, natural additives were obtained by aqueous extraction, an environment friendly and safe process. PMID:27596429

  12. Inedible cellulose-based biomass resist material amenable to water-based processing for use in electron beam lithography

    International Nuclear Information System (INIS)

    An electron beam (EB) lithography method using inedible cellulose-based resist material derived from woody biomass has been successfully developed. This method allows the use of pure water in the development process instead of the conventionally used tetramethylammonium hydroxide and anisole. The inedible cellulose-based biomass resist material, as an alternative to alpha-linked disaccharides in sugar derivatives that compete with food supplies, was developed by replacing the hydroxyl groups in the beta-linked disaccharides with EB-sensitive 2-methacryloyloxyethyl groups. A 75 nm line and space pattern at an exposure dose of 19 μC/cm2, a resist thickness uniformity of less than 0.4 nm on a 200 mm wafer, and low film thickness shrinkage under EB irradiation were achieved with this inedible cellulose-based biomass resist material using a water-based development process

  13. A Zeolite Imidazolate Framework ZIF-8 Catalyst for Friedel-Crafts Acylation

    Institute of Scientific and Technical Information of China (English)

    LienT.L.NGUYEN; Ky K.A.LE; Nam T.S.PHAN

    2012-01-01

    A zeolite imidazolate framework,ZIF-8,was synthesized and characterized by dynamic laser light scattering,X-ray powder diffraction,scanning electron microscopy,transmission electron microscopy,thermogravimetric analysis,Fourier transform infrared,atomic absorption spectrophotometry,and nitrogen adsorption measurements.The ZIF-8 was highly crystalline and porous with a surface area of over 1600 m2/g.Friedel-Crafts acylation of anisole and benzoyl chloride proceeded well in the presence of ZIF-8 (2-6 mol%) without the need for an inert atmosphere.The reaction afforded a selectivity of 93%-95% to the p-isomer.The solid catalyst can be separated from the reaction mixture by simple centrifugation and reused without significant degradation in catalytic activity.There was no leaching of active acid species into the reaction solution.

  14. X-ray topographic study of growth defects of trans-stilbene crystals grown from solutions

    Science.gov (United States)

    Klapper, Helmut; Zaitseva, Natalia; Carman, Leslie

    2015-11-01

    Single crystals of trans-stilbene, C14H12, with properties suitable for high-energy neutron detection were grown from solution in anisole and toluene by the temperature reduction method with growth rates up to 6 mm/day. From these crystals, slices of appropriate orientation and thickness of 2-4 mm were cut and studied by X-ray diffraction topography applying the Lang method using CuKα radiation. The topographs exhibit growth defects such as liquid inclusions, dislocations, striations, and faulty growth-sector boundaries. These defects occur in the same typical arrangements and geometries as is observed in all kinds of crystals grown on habit faces from solution. Besides growth dislocations originating from inclusions and propagating with the growth front, many plastic glide dislocations in the shape of loops or half-loops emitted from inclusions by stress relaxation are observed. The glide system underlying this plasticity is discussed.

  15. A Novel Non-phosgene Process for the Synthesis of Methyl N-Phenyl Carbamate from Methanol and Phenylurea:Effect of Solvent and Catalyst

    Institute of Scientific and Technical Information of China (English)

    WANG,Xin-Kui(王心葵); YAN,Shi-Run(闫世润); CAO,Yong(曹勇); FAN,Kang-Nian(范康年); HE,He-Yong(贺鹤勇); KANG,Mao-Qing(亢茂青); PENG,Shao-Yi(彭少逸)

    2004-01-01

    A novel environmentally benign process for the synthesis of methyl N-phenyl carbamate (MPC) from methanol and phenylurea was studied. Effect of solvent and catalyst on the reaction behavior was investigated. The IR spectra of methanol and phenylurea dissolved in different solvents were also recorded. Compared with use of methanol as both a reactant and a solvent, phenylurea conversion and selectivity to MPC increased by using toluene, benzene or anisole as a solvent, while phenylurea conversion decreased slightly by using n-octane as a solvent. The phenylurea conversion declined nearly 50% when dimethyl sulfoxide (DMSO) was used as a reaction media, and MPC selectivity decreased as well. The catalytic reaction tests showed that a basic catalyst enhanced the selectivity to MPC while an acidic catalyst promoted the formation of methyl carbamate and aniline. Moderate degree of basicity showed the best catalytic performance in the cases studied.

  16. Proton Donor/acceptor Propensities of Ammonia: Rotational Studies of its Molecular Complexes with Organic Molecules

    Science.gov (United States)

    Giuliano, Barbara M.; Maris, Assimo; Melandri, Sonia; Favero, Laura B.; Evangelisti, Luca; Caminati, Walther

    2009-06-01

    We studied the rotational spectra of the adducts of ammonia with several organic molecules, namely tert-butanol, glycidol, ethyl alcohol, anisol and 1,4-difluorobenzene. The adducts with glycidol and ethanol have been observed for both conformers of the substrate molecule. Based on the rotational and ^{14}N quadrupole coupling constants of the various complexes, we found a considerably different behaviour of ammonia, with respect to water, in its proton donor/acceptor double role. In the interaction with the three alcohol molecules, NH_{3} acts as a proton acceptor and the OH groups as a proton donor. However, in the case of glycidol-NH_{3}, a secundary N-H\\cdotsO interaction occurrs between ammonia and the ether oxygen. This interaction generates a sizable V_{3} barrier to the internal rotation of the NH_{3} moiety, while NH_{3} undergoes a free rotation in tert-butanol-NH_{3} and in ethanol-NH_{3}. As to the anisole-NH_{3} and 1,4-difluorobenzene-NH_{3} complexes, the NH_{3} group explicits its double proton donor/acceptor role, although through two weak (C_{Me}-H\\cdotsN and N-H\\cdotsπ) H-bonds. There is, however, an important difference between the two complexes, because in the first one NH_{3} lies out of the aromatic plane, while in the second one it is in the plane of the aromatic ring. B. M. Giuliano, M. C. Castrovilli, A. Maris, S. Melandri, W. Caminati and E. A. Cohen, Chem.Phys.Lett., 2008, 463, 330 B. M. Giuliano, S. Melandri, A. Maris, L. B. Favero and W. Caminati, Angew.Chem.Int.Ed., 2009, 48, 1102

  17. Desorption atmospheric pressure photoionization with polydimethylsiloxane as extraction phase and sample plate material

    Energy Technology Data Exchange (ETDEWEB)

    Vaikkinen, A. [Division of Pharmaceutical Chemistry, Faculty of Pharmacy, P.O. Box 56, FIN-00014 University of Helsinki (Finland); Kotiaho, T. [Division of Pharmaceutical Chemistry, Faculty of Pharmacy, P.O. Box 56, FIN-00014 University of Helsinki (Finland); Laboratory of Analytical Chemistry, Department of Chemistry, P.O. Box 55, FIN-00014 University of Helsinki (Finland); Kostiainen, R. [Division of Pharmaceutical Chemistry, Faculty of Pharmacy, P.O. Box 56, FIN-00014 University of Helsinki (Finland); Kauppila, T.J., E-mail: tiina.kauppila@helsinki.fi [Division of Pharmaceutical Chemistry, Faculty of Pharmacy, P.O. Box 56, FIN-00014 University of Helsinki (Finland)

    2010-12-03

    Desorption atmospheric pressure photoionization (DAPPI) is an ambient ionization technique for mass spectrometry (MS) that can be used to ionize polar as well as neutral and completely non-polar analytes. In this study polydimethylsiloxane (PDMS) was used as a solid phase extraction sorbent for DAPPI-MS analysis. Pieces of PDMS polymer were soaked in an aqueous sample, where the analytes were sorbed from the sample solution to PDMS. After this, the extracted analytes were desorbed directly from the polymer by the hot DAPPI spray solvent plume, without an elution step. Swelling and extracting the PDMS with a cleaning solvent prior to extraction diminished the high background in the DAPPI mass spectrum caused by PDMS oligomers. Acetone, hexane, pentane, toluene, diisopropylamine and triethylamine were tested for this purpose. The amines were most efficient in reducing the PDMS background, but they also suppressed the signals of low proton affinity analytes. Toluene was chosen as the optimum cleaning solvent, since it reduced the PDMS background efficiently and gave intensive signals of most of the studied analytes. The effects of DAPPI spray solvents toluene, acetone and anisole on the PDMS background and the ionization of analytes were also compared and extraction conditions were optimized. Anisole gave a low background for native PDMS, but toluene ionized the widest range of analytes. Analysis of verapamil, testosterone and anthracene from purified, spiked wastewater was performed to demonstrate that the method is suited for in-situ analysis of water streams. In addition, urine spiked with several analytes was analyzed by the PDMS method and compared to the conventional DAPPI procedure, where sample droplets are applied on PMMA surface. With the PDMS method the background ion signals caused by the urine matrix were lower, the S/N ratios of analytes were 2-10 times higher, and testosterone, anthracene and benzo[a]pyrene that were not detected from PMMA in urine

  18. Fate and metabolism of the brominated flame retardant tetrabromobisphenol A (TBBPA) in rice cell suspension culture.

    Science.gov (United States)

    Wang, Songfeng; Cao, Siqi; Wang, Yongfeng; Jiang, Bingqi; Wang, Lianhong; Sun, Feifei; Ji, Rong

    2016-07-01

    Tetrabromobisphenol A (TBBPA) is the brominated flame retardant with the highest production volume and its bioaccumulation in environment has caused both human health and environmental concerns, however the fate and metabolism of TBBPA in plants is unknown. We studied the fate, metabolites, and transformation of (14)C-labeled TBBPA in rice cell suspension culture. During the incubation for 14 days, TBBPA degradation occurred continuously in the culture, accompanied by formation of one anisolic metabolite [2,6-dibromo-4-(2-(2-hydroxy)-propyl)-anisole] (DBHPA) (50% of the degraded TBBPA) and cellular debris-bound residues (46.4%) as well as mineralization (3.6%). The cells continuously accumulated TBBPA in the cytoplasm, while a small amount of DBHPA (2.1% of the initially applied TBBPA) was detectable inside the cells only at the end of incubation. The majority of the accumulated residues in the cells was attributed to the cellular debris-bound residues, accounting for 70-79% of the accumulation after the first incubation day. About 5.4% of the accumulation was associated with cell organelles, which contributed 7.5% to the cellular debris-bound residues. Based on the fate and metabolism of TBBPA in the rice cell suspension culture, a type II ipso-substitution pathway was proposed to describe the initial step for TBBPA degradation in the culture and balance the fate of TBBPA in the cells. To the best of our knowledge, our study provides for the first time the insights into the fate and metabolism of TBBPA in plants and points out the potential role of type II ipso-hydroxylation substitution in degradation of alkylphenols in plants. Further studies are required to reveal the mechanisms for the bound-residue formation (e.g., binding of residues to specific cell wall components), nature of the binding, and toxicological effects of the bound residues and DBHPA. PMID:27105166

  19. Electrophilic Aromatic Substitution: New Insights into an Old Class of Reactions.

    Science.gov (United States)

    Galabov, Boris; Nalbantova, Didi; Schleyer, Paul von R; Schaefer, Henry F

    2016-06-21

    The classic SEAr mechanism of electrophilic aromatic substitution (EAS) reactions described in textbooks, monographs, and reviews comprises the obligatory formation of arenium ion intermediates (σ complexes) in a two-stage process. Our findings from several studies of EAS reactions challenge the generality of this mechanistic paradigm. This Account focuses on recent computational and experimental results for three types of EAS reactions: halogenation with molecular chlorine and bromine, nitration by mixed acid (mixture of nitric and sulfuric acids), and sulfonation with SO3. Our combined computational and experimental investigation of the chlorination of anisole with molecular chlorine in CCl4 found that addition-elimination pathways compete with the direct substitution processes. Detailed NMR investigation of the course of experimental anisole chlorination at varying temperatures revealed the formation of addition byproducts. Moreover, in the absence of Lewis acid catalysis, the direct halogenation processes do not involve arenium ion intermediates but instead proceed via concerted single transition states. We also obtained analogous results for the chlorination and bromination of several arenes in nonpolar solvents. We explored by theoretical computations and experimental spectroscopic studies the classic reaction of benzene nitration by mixed acid. The structure of the first intermediate in this process has been a subject of contradicting views. We have reported clear experimental UV/vis spectroscopic evidence for the formation of the first intermediate in this reaction. Our broader theoretical modeling of the process considers the effects of the medium as a bulk solvent but also the specific interactions of a H2SO4 solvent molecule with intermediates and transition states along the reaction path. In harmony with the obtained spectroscopic data, our computational results reveal that the structure of the initial π complex precludes the possibility of electronic

  20. New Linear Partitioning Models Based on Experimental Water: Supercritical CO2 Partitioning Data of Selected Organic Compounds.

    Science.gov (United States)

    Burant, Aniela; Thompson, Christopher; Lowry, Gregory V; Karamalidis, Athanasios K

    2016-05-17

    Partitioning coefficients of organic compounds between water and supercritical CO2 (sc-CO2) are necessary to assess the risk of migration of these chemicals from subsurface CO2 storage sites. Despite the large number of potential organic contaminants, the current data set of published water-sc-CO2 partitioning coefficients is very limited. Here, the partitioning coefficients of thiophene, pyrrole, and anisole were measured in situ over a range of temperatures and pressures using a novel pressurized batch-reactor system with dual spectroscopic detectors: a near-infrared spectrometer for measuring the organic analyte in the CO2 phase and a UV detector for quantifying the analyte in the aqueous phase. Our measured partitioning coefficients followed expected trends based on volatility and aqueous solubility. The partitioning coefficients and literature data were then used to update a published poly parameter linear free-energy relationship and to develop five new linear free-energy relationships for predicting water-sc-CO2 partitioning coefficients. A total of four of the models targeted a single class of organic compounds. Unlike models that utilize Abraham solvation parameters, the new relationships use vapor pressure and aqueous solubility of the organic compound at 25 °C and CO2 density to predict partitioning coefficients over a range of temperature and pressure conditions. The compound class models provide better estimates of partitioning behavior for compounds in that class than does the model built for the entire data set. PMID:27081725

  1. COLONIZATION OF GRAPE BERRIES BY REPRESENTATIVES OF THE GENUS ALTERNARIA AND THEIR OCCURRENCE IN THE STUM

    Directory of Open Access Journals (Sweden)

    Zuzana Mašková

    2013-02-01

    Full Text Available The aim of the study was to analyze the mycobiota occurring on the grapes originating from Slovak wine-growing regions. The main focus was to discover the presence of the representatives of the genus Alternaria on/in grape berries and in the stum.Using the direct method of placing grape berries on the culture medium was analyzed their total and endogenous (after superficial sterilization mycobiota. Plate dilution method was used for stum mycobiota determination. Alternaria spp. colonized grapeson the surface and inside with anisolation frequency (Fr of 100%. Moreover, 100% of the stum samples were positive for the presence of this genus. Their relative density (RD was 44.9% (unsterilized grapes, 57.9% (sterilized grapes and 6.35% (stum. In all the areas analysed we recorded 4 species-groups: A. alternata, A. arborescens, A. infectoria and A. tenuissima. With the highest Fr and RD occurredA. tenuissima species-group, followed by A. alternata and A. arborescens species-groups. All of them are potential producers of mycotoxins as alternariol, alternariol monomethylether, tenuazonic acid, altertoxin I, II and III.

  2. The environmental behaviour of polychlorinated phenols and its relevance to cork forest ecosystems: a review.

    Science.gov (United States)

    McLellan, Iain; Carvalho, Mariana; Silva Pereira, Cristina; Hursthouse, Andrew; Morrison, Calum; Tatner, Paul; Martins, Isabel; San Romão, M Vitória; Leitão, Maria

    2007-10-01

    Pentachlorophenol (PCP) has been used as a herbicide, biocide and preservative worldwide since the 1930s and as a result, extensive and prolonged contamination exists. The environmental impact increases when its many degradation products are taken into consideration. A number of chloroanisols and their related chlorophenols have been found in cork slabs collected from Portuguese oak tree forests before stopper manufacturing, and contamination by PCP and polychlorinated anisole (PCA) has been detected in Canadian forests. It is suggested that the use of polychlorinated phenols, in particular PCP, is thought to be a cause of the cork taint problem in wine, a major socio-economic impact not only for industry but on sensitive and highly biodiverse ecosystems. It also highlights particular issues relating to the regional regulation of potentially toxic chemicals and global economics world wide. To fully understand the impact of contamination sources, the mechanisms responsible for the fate and transport of PCP and its degradation products and assessment of their environmental behaviour is required. This review looks at the current state of knowledge of soil sorption, fate and bioavailability and identifies the challenges of degradation product identification and the contradictory evidence from field and laboratory observations. The need for a systematic evaluation of PCP contamination in relation to cork forest ecosystems and transfer of PCP between trophic levels is emphasised by discrepancies in bioaccumulation and toxicity. This is essential to enable long term management of not only transboundary contaminants, but also the sustainable management of socially and economically important forest ecosystems. PMID:17909638

  3. A Lean Methane Prelixed Laminar Flame Doped witg Components of Diesel Fuel. Part I: n)Butylbenzene

    CERN Document Server

    Pousse, Emir; Fournet, René; Battin-Leclerc, Frédérique; 10.1016/j.combustflame.2008.09.012

    2009-01-01

    To better understand the chemistry involved during the combustion of components of diesel fuel, the structure of a laminar lean premixed methane flame doped with n-butylbenzene has been investigated. The inlet gases contained 7.1% (molar) of methane, 36.8% of oxygen and 0.96% of n-butylbenzene corresponding to an equivalence ratio of 0.74 and a ratio C10H14 / CH4 of 13.5%. The flame has been stabilized on a burner at a pressure of 6.7 kPa using argon as diluent, with a gas velocity at the burner of 49.2 cm/s at 333 K. Quantified species included the usual methane C0-C2 combustion products, but also 16 C3-C5 hydrocarbons, 7 C1-C3 oxygenated compounds, as well as 20 aromatic products, namely benzene, toluene, phenylacetylene, styrene, ethylbenzene, xylenes, allylbenzene, propylbenzene, cumene, methylstyrenes, butenylbenzenes, indene, indane, naphthalene, phenol, benzaldehyde, anisole, benzylalcohol, benzofuran, and isomers of C10H10 (1-methylindene, dihydronaphtalene, butadienylbenzene). A new mechanism for the...

  4. 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. PMID:26478126

  5. Studies of reductive elimination reactions to form carbon-oxygen bonds from Pt(IV) complexes.

    Science.gov (United States)

    Williams, B S; Goldberg, K I

    2001-03-21

    The platinum(IV) complexes fac-L(2)PtMe(3)(OR) (L(2) = bis(diphenylphosphino)ethane, o-bis(diphenylphosphino)benzene, R = carboxyl, aryl; L = PMe(3), R = aryl) undergo reductive elimination reactions to form carbon-oxygen bonds and/or carbon-carbon bonds. The carbon-oxygen reductive elimination reaction produces either methyl esters or methyl aryl ethers (anisoles) and L(2)PtMe(2), while the carbon-carbon reductive elimination reaction affords ethane and L(2)PtMe(OR). Choice of reaction conditions allows the selection of either type of coupling over the other. A detailed mechanistic study of the reductive elimination reactions supports dissociation of the OR(-) ligand as the initial step for the C-O bond formation reaction. This is followed by a nucleophilic attack of OR(-) upon a methyl group bound to the Pt(IV) cation to produce the products MeOR and L(2)PtMe(2). C-C reductive elimination proceeds from L(2)PtMe(3)(OR) by initial L (L = PMe(3)) or OR(-) (L(2) = dppe, dppbz) dissociation, followed by C-C coupling from the resulting five-coordinate intermediate. Our studies demonstrate that both C-C and C-O reductive elimination reactions from Pt(IV) are more facile in polar solvents, in the presence of Lewis acids, and for OR(-) groups that contain electron withdrawing substituents. PMID:11456927

  6. Persulfate activation by naturally occurring trace minerals

    International Nuclear Information System (INIS)

    Highlights: ► Persulfate decomposition and activation by 13 trace minerals was investigated. ► Pyrite and cobaltite addition resulted in rapid persulfate decomposition. ► Pyrite promoted rapid generation of sulfate radical and hydroxyl radical. ► Most trace minerals did not decompose or activate persulfate. ► Some trace minerals inhibited persulfate decomposition and activation. - Abstract: The potential for 13 naturally occurring minerals to mediate the decomposition of persulfate and generate a range of reactive oxygen species was investigated to provide fundamental information on activation mechanisms when persulfate is used for in situ chemical oxidation (ISCO). Only four of the minerals (cobaltite, ilmenite, pyrite, and siderite) promoted the decomposition of persulfate more rapidly than persulfate–deionized water control systems. The other nine minerals decomposed persulfate at the same rate or more slowly than the control systems. Mineral-mediated persulfate activation was conducted with the addition of one of three probe compounds to detect the generation of reactive oxygen species: anisole (sulfate + hydroxyl radical), nitrobenzene (hydroxyl radical), and hexachloroethane (reductants and nucleophiles). The reduced mineral pyrite promoted rapid generation of sulfate + hydroxyl radical. However, the remainder of the minerals provided minimal potential for the generation of reactive oxygen species. The results of this research demonstrate that the majority of naturally occurring trace minerals do not activate persulfate to generate reactive oxygen species, and other mechanisms of activation are necessary to promote contaminant destruction in the subsurface during persulfate ISCO.

  7. Purification and characterization of a novel antitumor protein with antioxidant and deoxyribonuclease activity from edible mushroom Pholiota nameko.

    Science.gov (United States)

    Zhang, Yeni; Liu, Zhaokun; Ng, Tzi Bun; Chen, Zhihui; Qiao, Wentao; Liu, Fang

    2014-04-01

    A novel antitumor protein from the edible mushroom Pholiota nameko (PNAP) was purified through a two-step chromatographic procedure including SP cation exchange chromatogram and Superdex gel filtration. The approximate molecular weight was demonstrated to be 18.5 kDa by SDS-PAGE and ultracentrifugation analysis and N-terminal sequence was detected as AGRTFIGYNG by Edman degradation. Biochemical characterization showed that it exhibited significant antioxidant activity by effectively scavenging hydroxyl and 1,1-diphenyl-2-picrylhydrazyl radicals compared to standard antioxidant butylated hydroxy anisole. PNAP had deoxyribonuclease activity with the optimum pH and temperature were 5.0 and 60 °C respectively, as well as it can act on both double-stranded and single-stranded DNA, but preferentially on double-stranded DNA. PNAP displayed antitumor activity against cancer cell lines such as MCF7 and Hela cells. Human breast cancer MCF7 cells treated with PNAP produced typical apoptotic morphological changes including chromatin condensation, accumulation of sub-G1 cells and alternation of mitochondrial permeability. The PNAP induced apoptosis of MCF7 cells entailed loss of mitochondrial membrane potential resulting in release of cytochrome c into cytosol, activation of caspase-9 and caspase-3, which are responsible for the execution of apoptosis, implying intrinsic signal pathway is involved in PNAP induced apoptosis. PMID:24189312

  8. Ultrapressure liquid chromatography-tandem mass spectrometry assay using atmospheric pressure photoionization (UPLC-APPI-MS/MS) for quantification of 4-methoxydiphenylmethane in pharmacokinetic evaluation.

    Science.gov (United States)

    Farhan, Nashid; Fitzpatrick, Sean; Shim, Yun M; Paige, Mikell; Chow, Diana Shu-Lian

    2016-09-01

    4-Methoxydiphenylmethane (4-MDM), a selective augmenter of Leukotriene A4 Hydrolase (LTA4H), is a new anti-inflammatory compound for potential treatment of chronic obstructive pulmonary disease (COPD). Currently, there is no liquid chromatography tandem mass spectrometric (LC-MS/MS) method for the quantification of 4-MDM. A major barrier for developing the LC-MS/MS method is the inability of electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) to ionize 4-MDM due to its hydrophobicity and lack of any functional group for ionization. With the advent of atmospheric pressure photoionization (APPI) technique, many hydrophobic compounds have been demonstrated to ionize by charge transfer reactions. In this study, a highly sensitive ultrapressure liquid chromatography tandem mass spectrometry assay using atmospheric pressure photoionization (UPLC-APPI-MS/MS) for the quantifications of 4-MDM in rat plasma has been developed and validated. 4-MDM was extracted from the plasma by solid phase extraction (SPE) and separated chromatographically using a reverse phase C8 column. The photoionization (PI) was achieved by introducing anisole as a dopant to promote the reaction of charge transfer. The assay with a linear range of 5 (LLOQ)-400ngmL(-1) met the regulatory requirements for accuracy, precision and stability. The validated assay was employed to quantify the plasma concentrations of 4-MDM after an oral dosing in Sprague Dawley (SD) rats. PMID:27232150

  9. Stereoelectronic effects on 1H nuclear magnetic resonance chemical shifts in methoxybenzenes

    DEFF Research Database (Denmark)

    Lambert, Maja; Olsen, Lars; Jaroszewski, Jerzy W

    2006-01-01

    differences are due to different conformational behavior of the OH and OCH3 groups; while the ortho-disubstituted OH group remains planar in polyphenols due to hydrogen bonding and conjugative stabilization, the steric congestion in ortho-disubstituted anisoles outweighs the conjugative effects and forces the......Investigation of all O-methyl ethers of 1,2,3-benzenetriol and 4-methyl-1,2,3-benzenetriol (3-16) by 1H NMR spectroscopy and density-functional calculations disclosed practically useful conformational effects on 1H NMR chemical shifts in the aromatic ring. While the conversion of phenol (2) to...... Ar-OCH3 torsion out of the ring plane, resulting in large stereoelectronic effects on the chemical shift of Hpara. Conformational searches and geometry optimizations for 3-16 at the B3LYP/6-31G** level, followed by B3LYP/6-311++G(2d,2p) calculations for all low-energy conformers, gave excellent...

  10. Radiation induced effects in organic systems. Progress report, December 1, 1979-December 1, 1980

    Energy Technology Data Exchange (ETDEWEB)

    Johnsen, R H

    1980-01-01

    Progress was made in two areas of interest: the nature of the decay kinetics in systems yielding geminate radical pairs upon irradiation, and OH reactions with aromatic hydrocarbons. The work on geminate pairs has focused on the p,p' azoxy phenetole molecule, studied at low temperatures using both polycrystalline and single crystal systems. The result obtained appear to be somewhat different from those for the p,p' azoxy anisole system reported on earlier. Preliminary results on both microwave power saturation studies and decay kinetics suggest that the species stable only at low temperatures is not behaving as one would expect of geminate pairs. The gas-phase OH reactions have now been modified to produce reproducible results which can be interpreted as occurring in the bulk rather than as surface-modified. The most surprising result has been the observation of relatively large amounts of biphenyl produced from benzene by OH radical attack. This product has not been hither to reported and may be of significance in connection with the growing concentrations of substituted biphenyls in the environment.

  11. Radiation induced effects in organic systems. Progress report, December 1, 1979-December 1, 1980

    International Nuclear Information System (INIS)

    Progress was made in two areas of interest: the nature of the decay kinetics in systems yielding geminate radical pairs upon irradiation, and OH reactions with aromatic hydrocarbons. The work on geminate pairs has focused on the p,p' azoxy phenetole molecule, studied at low temperatures using both polycrystalline and single crystal systems. The result obtained appear to be somewhat different from those for the p,p' azoxy anisole system reported on earlier. Preliminary results on both microwave power saturation studies and decay kinetics suggest that the species stable only at low temperatures is not behaving as one would expect of geminate pairs. The gas-phase OH reactions have now been modified to produce reproducible results which can be interpreted as occurring in the bulk rather than as surface-modified. The most surprising result has been the observation of relatively large amounts of biphenyl produced from benzene by OH radical attack. This product has not been hither to reported and may be of significance in connection with the growing concentrations of substituted biphenyls in the environment

  12. New URJC-1 Material with Remarkable Stability and Acid-Base Catalytic Properties

    Directory of Open Access Journals (Sweden)

    Pedro Leo

    2016-02-01

    Full Text Available Emerging new metal-organic structures with tunable physicochemical properties is an exciting research field for diverse applications. In this work, a novel metal-organic framework Cu(HIT(DMF0.5, named URJC-1, with a three-dimensional non-interpenetrated utp topological network, has been synthesized. This material exhibits a microporous structure with unsaturated copper centers and imidazole–tetrazole linkages that provide accessible Lewis acid/base sites. These features make URJC-1 an exceptional candidate for catalytic application in acid and base reactions of interest in fine chemistry. The URJC-1 material also displays a noteworthy thermal and chemical stability in different organic solvents of different polarity and boiling water. Its catalytic activity was evaluated in acid-catalyzed Friedel–Crafts acylation of anisole with acetyl chloride and base-catalyzed Knoevenagel condensation of benzaldehyde with malononitrile. In both cases, URJC-1 material showed very good performance, better than other metal organic frameworks and conventional catalysts. In addition, a remarkable structural stability was proven after several consecutive reaction cycles.

  13. Environmental effects on the electrical properties of narrow-gap carbon nanotubes

    Science.gov (United States)

    Aspitarte, Lee; McCulley, Dan; Minot, Ethan

    Observations of single-walled carbon nanotubes (CNTs) with band gaps of 50 - 100 meV and diameters of approximately 2 nm pose an intriguing puzzle. The orthodox theory of CNTs predicts that such CNTs should have band gaps between 0 and 25 meV, yet these ``narrow-gap'' CNTs are routinely observed (band gaps in the range 50 - 100 meV). A possible explanation is that strong Coulomb interactions cause a Mott gap in nominally metallic CNTs (Deshpande et al., Science, 2009). To test this hypothesis, we have fabricated field-effect transistor devices from suspended narrow-gap CNTs. We have tested these devices in a variety of dielectric environments, including air, vacuum, TiO2 coatings, and molecular liquids such as oil, anisole, toluene, isopropanol, and water. In many cases we can relate changes in electrical properties to changes in electrostatic disorder, gate capacitance, mobility and band alignment. We will discuss the possibility of an interaction-driven effect that is changed by the dielectric environment.

  14. 1,2,3-Triazole-Substituted Oleanolic Acid Derivatives: Synthesis and Antiproliferative Activity

    Directory of Open Access Journals (Sweden)

    Guillermo Schmeda-Hirschmann

    2013-07-01

    Full Text Available Hybrid compounds are relevant products when searching for structure-activity relationships of natural products. Starting from the naturally occurring triterpene oleanolic acid, alkyl esters were prepared and treated with different aromatic azides using click chemistry to produce hybrid compounds. Some 18 new oleanolic acid derivatives were synthesized and the structures were confirmed by spectroscopic and spectrometric means. The antiproliferative activity of the new derivatives was evaluated towards normal lung fibroblasts (MRC-5, gastric epithelial adenocarcinoma (AGS, promyelocytic leukemia (HL-60, lung cancer (SK-MES-1 and bladder carcinoma (J82 cells. The alkyne esters 1 and 3 showed activity on all cell lines but without selectivity (19.6–23.1 μM and 14.1–56.2 μM, respectively, their respective methyl esters were inactive. Compounds with a benzene and p-anisole attached to the triazole ring, showed no antiproliferative effect. Introduction of a chlorine atom into the benzene ring (compound 9 elicited a selective effect against AGS cells (IC50 value: 8.9 μM. The activity was lost when the COOH function at C-28 was methylated. Better antiproliferative effect was found for compounds 11 and 15 bearing a p-toluenesulphonyl group, with values in the range of 10.8–47.1 μM and 11.5–22.2 μM, respectively. The effect, however, was not associated with selectivity.

  15. Non-target screening of extractable and non-extractable organic xenobiotics in riverine sediments of Ems and Mulde Rivers, Germany

    International Nuclear Information System (INIS)

    Subaquatic sediment samples derived form Elbe and Mulde Rivers, Germany, were analyzed for extractable and non-extractable anthropogenic organic compounds by a non-target screening approach. Applied methodologies were gas chromatography-mass spectrometry, dispersion extraction and degradation procedures, particularly alkaline and acidic hydrolysis, boron tribromide treatment, ruthenium tetroxide oxidation as well as pyrolysis and TMAH (tetramethylammonium hydroxide)-thermochemolysis. Numerous compounds were identified, including halogenated benzenes, anisoles, styrenes, alkanes, diphenylmethane derivates, anilines, phenols and diphenyl ethers. The results were interpreted with respect to compound specific modes of incorporation as well as to potential sources (e.g. municipal, agricultural, industrial). Extractable and non-extractable fractions differed significantly with respect to their qualitative and quantitative composition. For example, quantities in the extractable and non-extractable fractions of chlorinated benzenes differed up to factor 50. Among other significant results, the investigation revealed hints for a dependence of the mode of incorporation of chlorinated benzenes on their substitution pattern. - Analysis of both, extractable and non-extractable fraction of organic xenobiotics in sediments reveals a more detailed and comprehensive anthropogenic load profile

  16. Molecular Aggregation Behavior of One-Dimensional Poly(hexyl thiophene)/ Imogolite Nano fiber Hybrid

    International Nuclear Information System (INIS)

    Full text: Recent development in the solution derived P3HT nano fiber has brought significant attention because of its high aspect ratio and large specific surface area which allow large scale material properties improvement possible. Additionally, hybridization of P3HT nano fiber with surface modified imogolite can generate hybrid material for sophisticated optical, electronic and optoelectronic application. P3HT nano fiber was prepared via whisker method, in which P3HT will be dissolved in poor solvent of anisole at elevated temperature (80 degree Celsius) and cooled to room temperature at constant low cooling rate. Similar approach was used to prepare the P3HT/Imogolite nano fiber hybrid, where surface modified imogolite was mixed with P3HT solution during the dissolution process. The chemical and morphology of nano fiber hybrid were analyzed by DFM observation, UV-vis and FT-IR spectroscopy. While, the crystallinity of the sample was analyzed by X-ray diffraction technique using the beam line facility located at SPring-8, Hyogo, Japan. (author)

  17. Baseline isotopic data of polyhalogenated compounds

    International Nuclear Information System (INIS)

    The δ 2H- and δ 13C-values of polyhalogenated compounds were determined by EA-IRMS. Most of the compounds were related to the chloropesticides DDT and its metabolites, hexachlorocyclohexanes, and toxaphene, as well as several polybrominated compounds such as bromophenols and -anisoles. δ 2H-values ranged between -235 per mille and +75 per mille whereas δ 13C-values were found in the range -22 per mille to -38 per mille . No correlation between δ 2H- and δ 13C-values could be identified. Comparative analysis clarified that bromophenols and the corresponding bromoanisoles may vary in their isotopic distribution. 2H NMR was used to quantify abundances of 2H isotopomers. Quantification of isotopomers of 2,4-dibromophenol and 2,4-dibromoanisole proved that both compounds from different suppliers do not originate from the same source. Differences in the δ 2H-values of two toxaphene products were further investigated by the synthesis of products of different degree of chlorination from camphene. It was shown that the δ 13C-values remained mostly unaltered as was expected since no carbon is lost in this procedure. However, the reaction products became enriched in 2H with increasing degree of chlorination. Different δ 2H-values of the starting material will also impact the δ 2H-values of the chlorination products

  18. Search for Anomalous Single Top Quark Production in Association with a Photon in pp Collisions at $\\sqrt{s}$ = 8 TeV

    CERN Document Server

    Goldouzian, Reza

    2016-01-01

    This thesis reports the results of a first search for the flavor-changing neutral current(FCNC) through the anomalous production of single top quark in association witha photon due to the anomalous interactions of tqγ (q = u or c) in pp collisions. Thissearch is performed using 19.8 fb−1 of data collected with the CMS detector at thecenter-of-mass energy of 8 TeV.In this study we only concentrate on the muonic decay of the W-boson in topquark decay. The search is conducted in final states with an isolated muon, anisolated photon, jets, at most one of which is consistent with originating from theevolution of a b quark, and missing transverse momentum, corresponding to topquark decays, in which the W boson from the top quark decay is detected in the µν.A multivariate classification approach is chosen to achieve a powerful discrimination between signal like events and standard model backgrounds. No evidencefor the FCNC processes are observed. Upper limits at 95% confidence level on thestrengths of the ...

  19. Non-target screening of extractable and non-extractable organic xenobiotics in riverine sediments of Ems and Mulde Rivers, Germany

    Energy Technology Data Exchange (ETDEWEB)

    Kronimus, Alexander [Institute of Geology and Geochemistry of Petroleum and Coal, RWTH Aachen University, Lochnerstr. 4-20, D-52056 Aachen (Germany)]. E-mail: kronimus@lek.rwth-aachen.de; Schwarzbauer, Jan [Institute of Geology and Geochemistry of Petroleum and Coal, RWTH Aachen University, Lochnerstr. 4-20, D-52056 Aachen (Germany)]. E-mail: schwarzbauer@lek.rwth-aachen.de

    2007-05-15

    Subaquatic sediment samples derived form Elbe and Mulde Rivers, Germany, were analyzed for extractable and non-extractable anthropogenic organic compounds by a non-target screening approach. Applied methodologies were gas chromatography-mass spectrometry, dispersion extraction and degradation procedures, particularly alkaline and acidic hydrolysis, boron tribromide treatment, ruthenium tetroxide oxidation as well as pyrolysis and TMAH (tetramethylammonium hydroxide)-thermochemolysis. Numerous compounds were identified, including halogenated benzenes, anisoles, styrenes, alkanes, diphenylmethane derivates, anilines, phenols and diphenyl ethers. The results were interpreted with respect to compound specific modes of incorporation as well as to potential sources (e.g. municipal, agricultural, industrial). Extractable and non-extractable fractions differed significantly with respect to their qualitative and quantitative composition. For example, quantities in the extractable and non-extractable fractions of chlorinated benzenes differed up to factor 50. Among other significant results, the investigation revealed hints for a dependence of the mode of incorporation of chlorinated benzenes on their substitution pattern. - Analysis of both, extractable and non-extractable fraction of organic xenobiotics in sediments reveals a more detailed and comprehensive anthropogenic load profile.

  20. Catalytic Hydrodeoxygenation of Bio-oil Model Compounds over Pt/HY Catalyst

    Science.gov (United States)

    Lee, Heejin; Kim, Hannah; Yu, Mi Jin; Ko, Chang Hyun; Jeon, Jong-Ki; Jae, Jungho; Park, Sung Hoon; Jung, Sang-Chul; Park, Young-Kwon

    2016-06-01

    The hydrodeoxygenation of a model compound of lignin-derived bio-oil, guaiacol, which can be obtained from the pyrolysis of biomass to bio-oil, has attracted considerable research attention because of its huge potential as a substitute for conventional fuels. In this study, platinum-loaded HY zeolites (Pt/HY) with different Si/Al molar ratios were used as catalysts for the hydrodeoxygenation of guaiacol, anisole, veratrole, and phenol to a range of hydrocarbons, such as cyclohexane. The cyclohexane (major product) yield increased with increasing number of acid sites. To produce bio-oil with the maximum level of cyclohexane and alkylated cyclohexanes, which would be suitable as a substitute for conventional transportation fuels, the Si/Al molar ratio should be optimized to balance the Pt particle-induced hydrogenation with acid site-induced methyl group transfer. The fuel properties of real bio-oil derived from the fast pyrolysis of cork oak was improved using the Pt/HY catalyst.

  1. Palladium-catalyzed thiocarbonylation of aryl, vinyl, and benzyl bromides.

    Science.gov (United States)

    Burhardt, Mia N; Ahlburg, Andreas; Skrydstrup, Troels

    2014-12-19

    A catalytic protocol for synthesis of thioesters from aryl, vinyl, and benzyl bromides as well as benzyl chlorides was developed using only stoichiometric amounts of carbon monoxide, produced from a solid CO precursor inside a two-chamber system. As a catalytic system, the combination of bis(benzonitrile) palladium(II) chloride and Xantphos furnished the highest yields of the desired compounds, along with the weak base, NaOAc, in anisole at 120 °C. The choice of catalytic system as well as solvent turned out to be important in order to ensure a high chemoselectivity in the reaction. Both electron-rich and electron-deficient aryl bromides worked well in this reaction. Addition of 1 equiv of sodium iodide to the reaction improved the chemoselectivity with the electron-deficient aryl bromides. The thiol scope included both aryl and alkyl thiols, including 2-mercaptobenzophenones, whereby a thiocarbonylation followed by a subsequent McMurry coupling yielded differently substituted benzothiophenes. It was demonstrated that the methodology could be applied for (13)C introduction into the thiophene ring. PMID:24919457

  2. 营养型调和油配方及甘草、诃子提取物复合抗氧化剂对其抗氧化作用的研究%Study on the formulation of nutrition-based blend oil and the antioxidant activity of compound antioxidants from Glycyrrhiza uralensis extract and Terminalia chebula extract on it

    Institute of Scientific and Technical Information of China (English)

    刘艳凤; 刘雅丽; Chogsom Munkh-Amgalan; 陈贵林

    2015-01-01

    目的:研究甘草提取物(Glycyrrhiza uralensis extract, GUE)、诃子提取物(Terminalia chebula extract, TCE)复合抗氧化剂对营养型调和油氧化程度的影响。方法采用气质联用(gas chromatography-mass spectrometer, GC-MS)方法测定原料油中各类脂肪酸的含量,根据数学模型制备营养型调和油;然后采用 Schaal 烘箱法,评价复合抗氧化剂对营养型调和油的抗氧化作用,筛选出抗氧化作用较强的复合抗氧化剂。结果调和油的最佳配比花生油68.68%、葵花籽油19.23%、亚麻籽油12.08%。复合抗氧化剂对调和油的抗氧化作用顺序为:0.003%GUE+0.017%Vc>0.005%TCE+0.015%Vc>0.017%TCE+0.003%Ve>0.017%GUE+0.003%Ve,0.003%GUE+0.017%Vc对调和油的抗氧化作用最强,它优于丁基羟基茴香醚(Butyl hydroxyl anisole, BHA),与2,6-二叔丁基-4-甲基苯酚(2,6-Di-tert-butyl-p-cresol, BHT)相当。结论对于含有多不饱和脂肪酸多的贮存的油脂,甘草与诃子提取物复合抗氧化剂具有代替人工合成抗氧化剂的潜能。%Objective To ensure the formulation of nutrition-based blend oil and research the effect of antioxidants on the compound antioxidants of Glycyrrhiza uralensis Fisch. extract (GUE) and Terminalia chebula Retz. extract (TCE) on the nutrition-based blend oil. Methods According to the mathematical model for the preparation of nutrition-based blend oil, the oil content of all kinds of fatty acids in raw materials was determined by gas chromatography-mass spectrometry (GC-MS). Due to Schaal experiment the antioxidant capacity of compound antioxidants was evaluated. Results The optimal ratio to match the comparison of peanut oil, sunflower oil and flaxseed oil was 68.68:19.23:12.08. Synergistic effects were observed in the order:0.003%GUE+0.017%Vc>0.005%TCE+0.015%Vc>0.017%TCE+0.003%Ve>0.017%GUE+0.003%Ve by Schaal oven method, and especially for combinations of 0.003%GUE and 0.017%Vc, which showed a greater synergistic effect

  3. Retrospective monitoring of triclosan and methyl-triclosan in fish. Results from the German Environmental Specimen Bank

    Energy Technology Data Exchange (ETDEWEB)

    Boehmer, W.; Ruedel, H.; Wenzel, A. [Fraunhofer IME, Schmallenberg (Germany); Schroeter-Kermani, C. [Umweltbundesamt, Berlin (Germany)

    2004-09-15

    During the last years there were several reports on the appearance of the biocides triclosan (TCS; 5- chloro-2-(2,4-dichlorophenoxy)phenol; CAS No. 3380-34-5) and chlorophene (CP; 4-Chloro-2- (phenylmethyl)phenol; CAS No. 120-32-1) in the environment. TCS is used in numerous personal care products like toothpaste and soaps, but also in textiles and shoes. The current annual consumption in Germany is estimated to be 40 t (0.5 g per capita and year). During use large amounts of TCS and CP are disposed into waste water. Modern waste water treatment plants (WWTP) eliminate approximately 95 % of TCS, mainly by biodegradation and adsorption to sludge. It was observed that during waste water treatment methyl-triclosan (MTCS; 5-chloro-2-(2,4-dichlorophenoxy)anisole; CAS No. 4640-01-1) is formed, probably due to microbial methylation. In a WWTP effluent up to 1 % MTCS in relation to TCS was detected. The environmental half-life of TCS is assumed to be low, mainly because it is susceptible to photodegradation at environmental pH levels while MTCS is stable under these conditions. The logPow values of 4.7 for TCS and 5.2 for MTCS (estimated with KowWin Vers. 1,67, respectively) indicate potential for bioaccumulation. Based in order to investigate the exposure of aquatic organisms towards CP, TCS and MTCS in Germany a retrospective monitoring of breams (Abramis brama) from representative rivers was initiated. Samples from the period 1994 to 2003 were taken from the archive of the German Environmental Specimen Bank (ESB) to evaluate temporal changes and regional differences of the occurrence of the target compounds.

  4. Mycoremediation of wood and soil from an old sawmill area contaminated for decades

    Energy Technology Data Exchange (ETDEWEB)

    Valentín, Lara; Oesch-Kuisma, Hanna; Steffen, Kari T.; Kähkönen, Mika A.; Hatakka, Annele; Tuomela, Marja, E-mail: marja.tuomela@helsinki.fi

    2013-09-15

    Highlights: • We performed experiments with non-sterile soil and wood with aged contamination. • We isolated fungal strains from a saw mill site with chlorophenols contamination. •Fungal strains were screened for tolerance to native microbes and contamination. • The best fungi degraded chlorophenols and chlorinated dibenzo-p-dioxins and -furans. -- Abstract: We investigated the potential of white-rot and litter-decomposing fungi for the treatment of soil and wood from a sawmill area contaminated with aged chlorinated phenols, dibenzo-p-dioxins and furans (PCDD/F). Eight screening assays with emphasis on application of non-sterile conditions were carried out in order to select the strains with capability to withstand indigenous microbes and contamination. Nine fungi were then selected for degrading pentachlorophenol (PCP), and 2,3,4,6-tetrachlorophenol (2,3,4,6-TeCP) and mineralizing radiolabelled pentachlorophenol ({sup 14}C-PCP) in non-sterile soil or wood during 15 weeks of incubation. Soil indigenous microbes and fungal inoculated soil (fungal inoculum + indigenous microbes) achieved similar degradation of PCP and 2,3,4,6-TeCP and mineralization of {sup 14}C-PCP. However, the mineralization rate of {sup 14}C-PCP by indigenous microbes was much slower than that boosted by fungal inoculum. The litter-decomposing fungus (LDF) Stropharia rugosoannulata proved to be a suitable fungus for soil treatment. This fungus mineralized 26% of {sup 14}C-PCP and degraded 43% of 2,3,4,6-TeCP and 73% of PCP. Furthermore, S. rugosoannulata attained 13% degradation of PCDD/F (expressed as WHO-Toxic Equivalent). In wood, white-rot fungi grew and degraded chlorophenols better than LDF. No efficient indigenous degraders were present in wood. Interestingly, production of toxic chlorinated organic metabolites (anisoles and veratroles) by LDF in wood was negligible.

  5. Activity of essential oils and individual components against acetyl- and butyrylcholinesterase.

    Science.gov (United States)

    Orhan, Ilkay; Kartal, Murat; Kan, Yüksel; Sener, Bilge

    2008-01-01

    We have tested acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities of nineteen essential oils obtained from cultivated plants, namely one from Anethum graveolens L. (organic fertilizer), two from Foeniculum vulgare Mill. collected at fully-mature and flowering stages (organic fertilizer), two from Melissa officinalis L. (cultivated using organic and chemical fertilizers), two from Mentha piperita L. and M. spicata L. (organic fertilizer), two from Lavandula officinalis Chaix ex Villars (cultivated using organic and chemical fertilizers), two from Ocimum basilicum L. (green and purple-leaf varieties cultivated using only organic fertilizer), four from Origanum onites L., O. vulgare L., O. munitiflorum Hausskn., and O. majorana L. (cultivated using organic fertilizer), two from Salvia sclarea L. (organic and chemical fertilizers), one from S. officinalis L. (organic fertilizer), and one from Satureja cuneifolia Ten. (organic fertilizer) by a spectrophotometric method of Ellman using ELISA microplate-reader at 1 mg/ml concentration. In addition, a number of single components widely encountered in most of the essential oils [gamma-terpinene, 4-allyl anisole, (-)-carvone, dihydrocarvone, (-)-phencone, cuminyl alcohol, cumol, 4-isopropyl benzaldehyde, trans-anethole, camphene, iso-borneol, (-)-borneol, L-bornyl acetate, 2-decanol, 2-heptanol, methyl-heptanol, farnesol, nerol, iso-pulegol, 1,8-cineole, citral, citronellal, citronellol, geraniol, linalool, alpha-pinene, beta-pinene, piperitone, iso-menthone, menthofurane, linalyl oxide, linalyl ester, geranyl ester, carvacrol, thymol, menthol, vanilline, and eugenol] was also screened for the same activity in the same manner. Almost all of the essential oils showed a very high inhibitory activity (over 80%) against both enzymes, whereas the single components were not as active as the essential oils. PMID:18810999

  6. EVALUATION OF THE ANTIOXIDANT AND ANTIMICROBIAL PROPERTIES OF NOSTOC LINCKIA ISOLATED FROM KUKKARAHALLI LAKE, MYSORE

    Directory of Open Access Journals (Sweden)

    Jyoti Bala Chauhan

    2014-11-01

    Full Text Available The present study evaluates the antioxidant and antimicrobial activity of Nostoc linckia which was isolated from Kukkarahalli lake, Mysore and maintained in BG-12 medium. The antioxidant potential of the N. linckia extract was investigated using 2,2- Diphenyl, 1- Picryl Hydrazyl and 2, 2´- Azino- bis-(3- ethylbenzothiazoline- 6- sulfonic acid radical scavenging assays and ferric reducing power assay. It expressed DPPH radical scavenging activity at 1.58 mMTrolox Equivalent/g extract, ABTS˙ radical scavenging activity at 3.8 mMTE/g extract and total ferric reducing power at 1.05mgButylated Hydroxy Anisole Equivalents/ g extract. The radical scavenging activity was compared with BHA as standard wherein it expressed DPPH and ABTS˙+ radical scavenging activity of 2.8 mMTE/g and 4.3 mMTE/g respectively. In vitro bactericidal screening of ethanol extract of Nostoc linckia was carried out against six species of bacteria namely Bacillus cereus, Bacillus subtilis, Escherichia coli, Klebsiella oxytoca, Proteus vulgaris and Staphylococcus aureus wherein B. cereus, B. subtilis and E.coli expressed minimum bactericidal concentration values more than 1 mg/ml while K. oxytoca, P. vulgaris and S. aureus expressed MBC values of 0.51, 0.77 and 0.79 mg/ml respectiviely. The study also revealed minimum algicidal concentration of the extract at 0.625 mg/ml against Nostoc sp., Spirullina sp. Synecocystis sp., and 1.25 mg/ml against Gleocapsia sp by the 6th day after inoculation. The antimicrobial assay was carried out using micro titre plate method.

  7. Analytical and biological studies of kanji and extracts of its ingredient, daucus carota L

    International Nuclear Information System (INIS)

    A fermented beverage, Kanji, prepared from roots of Daucus carota L. subsp. sativus (Hoffm.) Arcang. var. vavilovii Mazk. (Apiaceae), despite long usage history has not been investigated for analytical studies and biological activities. Therefore, the present study aimed to investigate different types of Kanji samples and various types of extracts/fractions of root of the plant for a number of analytical studies and in vitro antioxidant activities. The Kanji sample, Lab-made Kanji, having better analytical and biological profile was further investigated for preliminary clinical studies. The analytical studies indicated that Lab-made Kanji was having comparatively higher contents of phytochemicals than that of the commercial Kanji samples, different types of extracts and fractions (P < 0.05). All the Kanji samples and aqueous and ethanol extracts of fresh roots exhibited comparable antioxidant activities in DPPH assay (52.20 - 54.19%) that were higher than that of methanol extract (48.78%) of dried roots. The antiradical powers (1/ EC50) of Lab-made Kanji and aqueous extract were found to be higher than that of the ethanol and methanol extracts. In beta-carotene linoleate assay, the Kanji samples showed higher activity than that of the methanol extract, but comparable to that of the vitamin-E and butylated hydroxyl anisole (BHA) (P < 0.05). A preliminary clinical evaluation indicated that Kanji has no harmful effect on blood components, liver function and serum lipid profile. The results of the present study indicate that Kanji is an effective antioxidant beverage. (author)

  8. Factors inducing human umbilical cord blood-derived mesenchymal stem cells to differentiate into neuron-like cells

    Institute of Scientific and Technical Information of China (English)

    Nawei Zhang; Fengqing Ji

    2006-01-01

    OBJECTIVE:Human umbilical cord blood-derived mesenchymal stem cells (HUCB-derived MSCs)can differentiate into neuron-like cells,which can be used to treat some central nervous system(CNS)diseases.To investigate the factors,which can induce HUCB-derived MSCs to differentiate into neuron-like cells,so as to find effective methods for future clinical application.DATA SOURCES:Using the key terms"human umbilical cord blood"combined with"mesenchymal stem cells,neuron-like cells,neural cells"respectively,the relevant articles in English published during the period from January 1999 to June 2006 were searched from the Medline database.Meanwhile,relevant Chinese articles published from January 1999 to June 2006 were searched Using the same key terms.STUDY SELECTION: All articles associated with the differentiation from human umbilical cord blood into neuron-like cells were selected firstly.Then the full texts were looked up by searchling Ovid medical Journals full-text database and Elsevier Electrical Journals Full-text Database.Articles with full expeiments,enrolled in inducible factors or involved inducible mechanism were retdeved.DATA EXTRACTION:Among 119 collected correlative articles,29 were involved and 90 were excluded.DATA SYNTHESIS:The inducible factors of HUCB-derived MSCs differentiatling into neuron-like cells included renal endothelial growth factors,fibroblasts,β-mercaptoethanol,dimethyl sulfoxide,butyl hydroxyl anisol,brain-derived neurotrophic factor,Danshen,retinoic acid,sodium ferulate and so on,but its mechanism was unclear.CONCLUSION:Human umbilical cord blood-derived MSCs can differentiate into neuron-like cells,with varied inductors.

  9. Characterization of volatiles of necrotic Stenocereus thurberi and Opuntia littoralis and toxicity and olfactory preference of Drosophila melanogster, D. mojavensis wrigleyi, and D. mojavensis sonorensis to necrotic cactus volatiles.

    Science.gov (United States)

    Wright, Cynthia R; Setzer, William N

    2014-08-01

    Drosophila mojavensis wrigleyi and D. mojavensis sonorensis are geographically separated races of cactophilic fruit flies. D. mojavensis sonorensis inhabits the Sonoran Desert and utilizes necrotic rots of Stenocereus thurberi Engelm. as a food source and to oviposit while D. mojavensis wrigleyi inhabits Santa Catalina Island, California and utilizes the necrotic rots of Opuntia littoralis (Engelm.) Cockerell. The objectives of this study were to determine the volatile compositions of the necrotic cacti and to determine if the volatile components show either selective toxicity or attraction toward the fruit flies. The volatile chemical compositions of field-rot specimens of both necrotic cacti were obtained by dynamic headspace (purge-and-trap) and hydrodistillation techniques and analyzed by gas chromatography - mass spectrometry. The volatile fraction of necrotic S. thurberi early rot was dominated by carboxylic acids (84.8%) and the late rot by p-cresol (32.6% in the dynamic headspace sample and 55.9% in the hydrodistilled sample). O. littoralis volatiles were dominated by carboxylic acids (86% in the dynamic headspace sample and 89.1% in the hydrodistilled sample). Fifteen compounds that were identified in the necrotic rot volatiles were used to test insecticidal activity and olfactory preference on the cactophilic Drosophila species, as well as D. melanogaster. Differences in toxicity and olfactory preference were observed between the different taxa. Both races of D. mojavensis exhibited toxicity to benzaldehyde and 2-nonanone, while butanoic acid and palmitic acid were tolerated at high concentrations. D. m. wrigleyi demonstrated a greater olfactory preference for anisole, butanoic acid, 2-heptanone, and palmitic acid than did D. m. sonorensis, while D. m. sonorensis demonstrated a greater preference for hexadecane, octanoic acid, and oleic acid than did D. m. wrigleyi. PMID:25233605

  10. Hydroxylated and methoxylated polybrominated diphenyl ethers in long-tailed ducks (Clangula hyemalis) and their main food, Baltic blue mussels (Mytilus trossulus × Mytilus edulis).

    Science.gov (United States)

    Dahlberg, Anna-Karin; Chen, Vivian Lindberg; Larsson, Kjell; Bergman, Åke; Asplund, Lillemor

    2016-02-01

    Long-tailed ducks (Clangula hyemalis) that breed in northern Europe and western Siberia and commonly winter in the Baltic Sea, are threatened by a significant population decrease. The ducks are, by primarily feeding on Baltic blue mussels (Mytilus trossulus × Mytilus edulis) while wintering in the Baltic Sea, potentially subjected to high levels of toxic hydroxylated polybrominated diphenyl ethers (OH-PBDEs). To assess long-tailed ducks exposure to polybrominated phenols (PBPs), polybrominated anisoles (PBAs), hydroxylated polybrominated diphenyl ethers (OH-PBDEs), their methylated counterparts (MeO-PBDEs) and polybrominated diphenyl ethers (PBDEs), livers of ten long-tailed ducks wintering in the Baltic Sea were analysed. Pattern and levels of analytes in long-tailed ducks (liver) and blue mussels sampled in March and May at nine sites in the Baltic Sea were compared. The geometric mean concentration (ng/g l.w.) in livers of long-tailed ducks and Baltic blue mussels were: Σ(2)PBPs: 0.57 and 48; Σ(2)PBAs: 0.83 and 11; Σ(7)OH-PBDEs: 6.1 and 45; Σ(7)MeO-PBDEs: 3.8 and 69; Σ(7)PBDEs: 8.0 and 7.2, respectively. Based on an estimated daily intake of 450 g fresh blue mussel meat, long-tailed ducks daily dietary intake of brominated substances while foraging in the Baltic Sea in March-May was estimated to; 390 ng Σ(2)PBPs, 90 ng Σ(2)PBAs, 370 ng Σ(7)OH-PBDEs, 590 ng Σ(7)MeO-PBDEs and 59 ng Σ(7)PBDEs. The low levels of PBPs, PBAs, OH-PBDEs and MeO-PBDEs in the long-tailed duck livers compared to blue mussel, despite a continuous daily intake, suggest that these compounds are poorly retained in long-tailed ducks. PMID:26495833

  11. Non-polar halogenated natural products bioaccumulated in marine samples. II. Brominated and mixed halogenated compounds.

    Science.gov (United States)

    Vetter, Walter; Jun, Wu

    2003-07-01

    Several identified and potential natural brominated bioaccumulative compounds were studied in this work. 4,6-dibromo-2-(2('),4(')-dibromo)phenoxyanisole (BC-2) previously detected in Australian marine mammals and isolated from sponges, was synthesized. Two byproducts (a tetrabromo isomer and a tribromo congener) were investigated as well. The byproducts of the synthesis were not identified in the environmental samples investigated. Previously described natural brominated compounds (BC-1, BC-2, BC-3, BC-10, BC-11, MHC-1) and anthropogenic brominated diphenyl ethers (BDE-47, BDE-99, BDE-100, BDE-154) were detected in a sample of human milk. The sample was from a woman from the Faeroe Islands who frequently consumed fish as well as whale blubber and meat. The most abundant compound originated from the natural tetrabromo phenoxyanisole BC-3 which may have a 3:1 distribution of bromine on the two phenyl units. This sample also accumulated a dibromochloroanisole, as well as a previously unknown mixed halogenated compound (MHC-X) and an unknown, most likely aromatic brominated compound. Co-elutions on a DB-5 column were found for BDE-99 and BC-11 as well as BDE-154 and the unknown brominated compound. This suggests that quantification of these two compounds has to be carried out carefully.Two samples of lower trophic level, namely Baltic cod liver and Mexican mussel tissue, were investigated as well. The cod liver samples contained BDE congeners but also abundant signals for the natural 2,3,3('),4,4('),5,5(')-heptachloro-1(')-methyl-1,2(')-bipyrrole Q1 and tribromoanisole (TBA). The mussel sample contained Q1, TBA, another halogenated anisole, BC-1, BC-2, and BC-3, as well as additional, potential natural brominated compounds in the elution range of tribromophenoxyanisoles. PMID:12738265

  12. Analyzing sites of OH radical attack (ring vs. side chain) in oxidation of substituted benzenes via dual stable isotope analysis (δ(13)C and δ(2)H).

    Science.gov (United States)

    Zhang, Ning; Geronimo, Inacrist; Paneth, Piotr; Schindelka, Janine; Schaefer, Thomas; Herrmann, Hartmut; Vogt, Carsten; Richnow, Hans H

    2016-01-15

    OH radicals generated by the photolysis of H2O2 can degrade aromatic contaminants by either attacking the aromatic ring to form phenolic products or oxidizing the substituent. We characterized these competing pathways by analyzing the carbon and hydrogen isotope fractionation (εC and εH) of various substituted benzenes. For benzene and halobenzenes that only undergo ring addition, low values of εC (-0.7‰ to -1.0‰) were observed compared with theoretical values (-7.2‰ to -8‰), possibly owing to masking effect caused by pre-equilibrium between the substrate and OH radical preceding the rate-limiting step. In contrast, the addition of OH radicals to nitrobenzene ring showed a higher εC (-3.9‰), probably due to the lower reactivity. Xylene isomers, anisole, aniline, N,N-dimethylaniline, and benzonitrile yielded normal εH values (-2.8‰ to -29‰) indicating the occurrence of side-chain reactions, in contrast to the inverse εH (11.7‰ to 30‰) observed for ring addition due to an sp(2) to sp(3) hybridization change at the reacting carbon. Inverse εH values for toluene (14‰) and ethylbenzene (30‰) were observed despite the formation of side-chain oxidation products, suggesting that ring addition has a larger contribution to isotope fractionation. Dual element isotope slopes (∆δ(2)H/∆δ(13)C) therefore allow identification of significant degradation pathways of aromatic compounds by photochemically induced OH radicals. Issues that should be addressed in future studies include quantitative determination of the contribution of each competing pathway to the observed isotope fractionation and characterization of physical processes preceding the reaction that could affect isotope fractionation. PMID:26520272

  13. Primary investigation on contamination pattern of legacy and emerging halogenated organic pollutions in freshwater fish from Liaohe River, Northeast China

    International Nuclear Information System (INIS)

    Legacy halogenated compounds, including polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and emerging organo-halogen pollutants such as Dechlorane Plus (DP), were detected in fish from an old industrial region in Northeast China. PCBs and PBDEs were detected in all of the samples, with concentrations ranging from 38.15 to 170.51 ng/g lipid weight, and 9.40–39.69 ng/g lipid weight, respectively. DP was detected in more than 90% of the samples with concentrations ranging from not detected (ND) to 470 pg g/g lipid weight. Compared with similar data in other areas of the world, PCBs, PBDEs and DP in fish from Liaohe River were at medium or low level. An unusually high percentage of PCB-209 was first reported in the fish samples collected from China. Other halogenated pollutions, such as dichlorodiphenyltrichloroethane (DDT) and its metabolites, octachlorostyrene, chlorinated anisole, chlorinated thioanisole, triclosan-methyl, and other pesticides, have also been identified in the fish samples. - Highlights: ► DP was reported in fish samples from river close to an old industrial base in China. ► The first report on the unusually high fraction of PCB-209 in samples from China. ► GC × GC–TOFMS was used to identify non-targeted halogenated pollutants. - An unusually high percentage of PCB-209 was first reported in the fish samples collected from China, which might indicate that there were distinct sources of pure PCB-209 in the region of Liaohe River.

  14. Low-cost copper complexes as p-dopants in solution processable hole transport layers

    International Nuclear Information System (INIS)

    We demonstrate the usage of the Lewis-acidic copper(II)hexafluoroacetylacetonate (Cu(hfac)2) and copper(II)trifluoroacetylacetonate (Cu(tfac)2) as low-cost p-dopants for conductivity enhancement of solution processable hole transport layers based on small molecules in organic light emitting diodes (OLEDs). The materials were clearly soluble in mixtures of environmentally friendly anisole and xylene and spin-coated under ambient atmosphere. Enhancements of two and four orders of magnitude, reaching 4.0 × 10−11 S/cm with a dopant concentration of only 2 mol% Cu(hfac)2 and 1.5 × 10−9 S/cm with 5 mol% Cu(tfac)2 in 2,2′,7,7′-tetra(N,N-ditolyl)amino-9,9-spiro-bifluorene (spiro-TTB), respectively, were achieved. Red light emitting diodes were fabricated with reduced driving voltages and enhanced current and power efficiencies (8.6 lm/W with Cu(hfac)2 and 5.6 lm/W with Cu(tfac)2) compared to the OLED with undoped spiro-TTB (3.9 lm/W). The OLED with Cu(hfac)2 doped spiro-TTB showed an over 8 times improved LT50 lifetime of 70 h at a starting luminance of 5000 cd/m2. The LT50 lifetime of the reference OLED with PEDOT:PSS was only 8 h. Both non-optimized OLEDs were operated at similar driving voltage and power efficiency

  15. Low-cost copper complexes as p-dopants in solution processable hole transport layers

    Energy Technology Data Exchange (ETDEWEB)

    Kellermann, Renate [Department for Materials Science and Engineering, Chair for Materials for Electronics and Energy Technology, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen 91058 (Germany); Siemens AG – Corporate Technology, Guenther-Scharowsky-Str. 1, Erlangen 91058 (Germany); Taroata, Dan; Maltenberger, Anna; Hartmann, David; Schmid, Guenter [Siemens AG – Corporate Technology, Guenther-Scharowsky-Str. 1, Erlangen 91058 (Germany); Brabec, Christoph J. [Department for Materials Science and Engineering, Chair for Materials for Electronics and Energy Technology, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen 91058 (Germany)

    2015-09-07

    We demonstrate the usage of the Lewis-acidic copper(II)hexafluoroacetylacetonate (Cu(hfac){sub 2}) and copper(II)trifluoroacetylacetonate (Cu(tfac){sub 2}) as low-cost p-dopants for conductivity enhancement of solution processable hole transport layers based on small molecules in organic light emitting diodes (OLEDs). The materials were clearly soluble in mixtures of environmentally friendly anisole and xylene and spin-coated under ambient atmosphere. Enhancements of two and four orders of magnitude, reaching 4.0 × 10{sup −11} S/cm with a dopant concentration of only 2 mol% Cu(hfac){sub 2} and 1.5 × 10{sup −9} S/cm with 5 mol% Cu(tfac){sub 2} in 2,2′,7,7′-tetra(N,N-ditolyl)amino-9,9-spiro-bifluorene (spiro-TTB), respectively, were achieved. Red light emitting diodes were fabricated with reduced driving voltages and enhanced current and power efficiencies (8.6 lm/W with Cu(hfac){sub 2} and 5.6 lm/W with Cu(tfac){sub 2}) compared to the OLED with undoped spiro-TTB (3.9 lm/W). The OLED with Cu(hfac){sub 2} doped spiro-TTB showed an over 8 times improved LT{sub 50} lifetime of 70 h at a starting luminance of 5000 cd/m{sup 2}. The LT{sub 50} lifetime of the reference OLED with PEDOT:PSS was only 8 h. Both non-optimized OLEDs were operated at similar driving voltage and power efficiency.

  16. Knock Resistance and Fine Particle Emissions for Several Biomass-Derived Oxygenates in a Direct-Injection Spark-Ignition Engine

    Energy Technology Data Exchange (ETDEWEB)

    Ratcliff, Matthew A.; Burton, Jonathan; Sindler, Petr; Christensen, Earl; Fouts, Lisa; Chupka, Gina M.; McCormick, Robert L.

    2016-04-01

    Several high octane number oxygenates that could be derived from biomass were blended with gasoline and examined for performance properties and their impact on knock resistance and fine particle emissions in a single cylinder direct-injection spark-ignition engine. The oxygenates included ethanol, isobutanol, anisole, 4-methylanisole, 2-phenylethanol, 2,5-dimethyl furan, and 2,4-xylenol. These were blended into a summertime blendstock for oxygenate blending at levels ranging from 10 to 50 percent by volume. The base gasoline, its blends with p-xylene and p-cymene, and high-octane racing gasoline were tested as controls. Relevant gasoline properties including research octane number (RON), motor octane number, distillation curve, and vapor pressure were measured. Detailed hydrocarbon analysis was used to estimate heat of vaporization and particulate matter index (PMI). Experiments were conducted to measure knock-limited spark advance and particulate matter (PM) emissions. The results show a range of knock resistances that correlate well with RON. Molecules with relatively low boiling point and high vapor pressure had little effect on PM emissions. In contrast, the aromatic oxygenates caused significant increases in PM emissions (factors of 2 to 5) relative to the base gasoline. Thus, any effect of their oxygen atom on increasing local air-fuel ratio was outweighed by their low vapor pressure and high double-bond equivalent values. For most fuels and oxygenate blend components, PMI was a good predictor of PM emissions. However, the high boiling point, low vapor pressure oxygenates 2-phenylethanol and 2,4-xylenol produced lower PM emissions than predicted by PMI. This was likely because they did not fully evaporate and combust, and instead were swept into the lube oil.

  17. Comparative effects of gamma and microwave irradiation on the quality of black pepper

    International Nuclear Information System (INIS)

    Powdered black pepper from Egyptian markets, was irradiated with different recommended doses of gamma rays (5.0 and 10.0 kGy) and with microwaves for different periods (20, 40 and 75 s) to improve its hygienic quality. The most common bacterial isolates were of three genera Bacillus, Clostridium and Micrococcus (7.5x106), whereas the predominant fungi (7.8x104) were Aspergillus species, A.glaucus, A.flavus, A.niger and A.ochraceus. Doses of gamma irradiation used (5.0 and 10 kGy) were sufficient to decrease spore-forming bacteria (SFB) and to inhibit the fungal flora and coliforms which contaminated the black pepper powder. Microwave treatments for 40 s and 75 s were of the same effectiveness whereas treatment for 20 s was less so. GLC analysis proved the presence of 31 peaks, only 19 compounds were identified as monoterpene hydrocarbons (56.21%), the major one being β-phellandrene and limonene. Sesquiterpenes were also present, mainly β-caryollphyllene (3.69%) as well as oxygenated compounds such as terpenol, gerniol, Me-chavicol, eugenol and anisol. Gamma irradiation at 5 kGy and 10 kGy respectively decreased the numbers of identified compounds from 21 (86.58% concentration) in untreated pepper to 16 (59.22% concentration), 15 (54.06% concentration). In comparison, microwave treatments, particularly for 40 s and 75 s, increased the concentration of the same compounds. The results obtained indicate that microwave treatment, under these conditions, is a safe and suitable technique for decontamination of black pepper which does not result in a great loss of flavour compounds, as compared with recommended doses of gamma irradiation. (orig.)

  18. Synthesis of polyamide supports for use in peptide synthesis and as peptide-resin conjugates for antibody production.

    Science.gov (United States)

    Kanda, P; Kennedy, R C; Sparrow, J T

    1991-10-01

    We have synthesized beaded, hydrophilic cross-linked, aminoalkyl polydimethylacrylamide supports upon which peptides have been assembled using standard Boc or Fmoc chemistry in automated equipment. The resins were prepared by the free radical-initiated co-polymerization of N,N-dimethylacrylamide, N,N'-bisacrylyl-1,3-diaminopropane, and a functional monomer which were contained in a reverse-phase, detergent-emulsified suspension. The functional monomers used were N-(2-(methylsulfonyl)ethyloxycarbonyl)-allyl-amine (MSC-allylamine), N-acrylyl-1,6-diaminohexane hydrochloride or N-methacrylyl-1,3-diamino-propane hydrochloride. The MSC protecting group was removed by treatment of the resin with methanolic base during workup. After coupling of N-alpha-t-butyloxycarbonyl-alanine (Boc-alanine), amino acid analyses gave resin loading capacities between 0.15 mmol/g and 1.4 mmol/g, depending on the concentration and composition of the functional monomer. The resulting polymers were highly swollen by polar solvents including aqueous buffers. Peptides were synthesized on these supports after attaching the first amino acid directly or through a cleavable ester linker. When the carboxyl-terminal amino acid was coupled as the 4-oxymethylbenzoic acid derivative, the peptide could be deprotected and remain attached to the hydrophilic polymer since the peptide-benzyl ester bond was stable to HF deprotection at 0 degrees in the presence of 10% anisole and 1% ethanedithiol. The resulting peptidyl-resin could be swollen in aqueous buffers and injected into animals for the production of antibodies. PMID:1797711

  19. Synthesis of tin and tin oxide nanoparticles of low size dispersity for application in gas sensing.

    Science.gov (United States)

    Nayral, C; Viala, E; Fau, P; Senocq, F; Jumas, J C; Maisonnat, A; Chaudret, B

    2000-11-17

    Nanocomposite core-shell particles that consist of a Sn0 core surrounded by a thin layer of tin oxides have been prepared by thermolysis of [(Sn(NMe2)2)2] in anisole that contains small, controlled amounts of water. The particles were characterized by means of electronic microscopies (TEM, HRTEM, SEM), X-ray diffraction (XRD) studies, photoelectron spectroscopy (XPS), and Mossbauer spectroscopy. The TEM micrographs show spherical nanoparticles, the size and size distribution of which depends on the initial experimental conditions of temperature, time, water concentration, and tin precursor concentration. Nanoparticles of 19 nm median size and displaying a narrow size distribution have been obtained with excellent yield in the optimized conditions. HRTEM, XPS, XRD and Mossbauer studies indicate the composite nature of the particles that consist of a well-crystallized tin beta core of approximately equals 11 nm covered with a layer of approximately equals 4 nm of amorphous tin dioxide and which also contain quadratic tin monoxide crystallites. The thermal oxidation of this nanocomposite yields well-crystallized nanoparticles of SnO2* without coalescence or size change. XRD patterns show that the powder consists of a mixture of two phases: the tetragonal cassiterite phase, which is the most abundant, and an orthorhombic phase. In agreement with the small SnO2 particle size, the relative intensity of the adsorbed dioxygen peak observed on the XPS spectrum is remarkable, when compared with that observed in the case of larger SnO2 particles. This is consistent with electrical conductivity measurements, which demonstrate that this material is highly sensitive to the presence of a reducing gas such as carbon monoxide. PMID:11151840

  20. Ionization of EPA contaminants in direct and dopant-assisted atmospheric pressure photoionization and atmospheric pressure laser ionization.

    Science.gov (United States)

    Kauppila, Tiina J; Kersten, Hendrik; Benter, Thorsten

    2015-06-01

    Seventy-seven EPA priority environmental pollutants were analyzed using gas chromatography-mass spectrometry (GC-MS) equipped with an optimized atmospheric pressure photoionization (APPI) and an atmospheric pressure laser ionization (APLI) interface with and without dopants. The analyzed compounds included e.g., polycyclic aromatic hydrocarbons (PAHs), nitro compounds, halogenated compounds, aromatic compounds with phenolic, acidic, alcohol, and amino groups, phthalate and adipatic esters, and aliphatic ethers. Toluene, anisole, chlorobenzene, and acetone were tested as dopants. The widest range of analytes was ionized using direct APPI (66/77 compounds). The introduction of dopants decreased the amount of compounds ionized in APPI (e.g., 54/77 with toluene), but in many cases the ionization efficiency increased. While in direct APPI the formation of molecular ions via photoionization was the main ionization reaction, dopant-assisted (DA) APPI promoted ionization reactions, such as charge exchange and proton transfer. Direct APLI ionized a much smaller amount of compounds than APPI (41/77 compounds), showing selectivity towards compounds with low ionization energies (IEs) and long-lived resonantly excited intermediate states. DA-APLI, however, was able to ionize a higher amount of compounds (e.g. 51/77 with toluene), as the ionization took place entirely through dopant-assisted ion/molecule reactions similar to those in DA-APPI. Best ionization efficiency in APPI and APLI (both direct and DA) was obtained for PAHs and aromatics with O- and N-functionalities, whereas nitro compounds and aliphatic ethers were the most difficult to ionize. Halogenated aromatics and esters were (mainly) ionized in APPI, but not in APLI. PMID:25828352

  1. A generic static headspace gas chromatography method for determination of residual solvents in drug substance.

    Science.gov (United States)

    Cheng, Chang; Liu, Shaorong; Mueller, Bradford J; Yan, Zimeng

    2010-10-01

    In order to increase productivity of drug analysis in the pharmaceutical industry, an efficient and sensitive generic static headspace gas chromatography (HSGC) method was successfully developed and validated for the determination of 44 classes 2 and 3 solvents of International Conference of Harmonization (ICH) guideline Q3C, as residual solvents in drug substance. In order to increase the method sensitivity and efficiency in sample equilibration, dimethylsulfoxide (DMSO) was selected as the sample diluent based on its high capacity of dissolving drug substance, stability and high boiling point. The HS sample equilibration temperature and equilibration time are assessed in ranges of 125-150°C and 8-15 min, respectively. The results indicate that the residual solvents in 200mg of drug substance can be equilibrated efficiently in HS sampler at 140°C for 10 min. The GC parameters, e.g. sample split ratio, carrier flow rate and oven temperature gradient are manipulated to enhance the method sensitivity and separation efficiency. The two-stage gradient GC run from 35 to 240°C, using an Agilent DB-624 capillary column (30 m long, 0.32 mm I.D., 1.8 μm film thickness), is suitable to determine 44 ICH classes 2 and 3 solvents in 30 min. The method validation results indicate that the method is accurate, precise, linear and sensitive for solvents assessed. The recoveries of most of these solvents from four drug substances are greater than 80% within the method determination ranges. However, this method is not suitable for the 10 remaining ICH classes 2 and 3 solvents, because they are too polar (e.g. formic acid and acidic acid), or have boiling points higher than 150°C, (e.g. anisol and cumene). In comparison with the previous published methods, this method has a much shorter sample equilibration time, a better separation for many solvents, a higher sensitivity and a broader concentration range. PMID:20801455

  2. Consumer's evaluation of the effects of gamma irradiation and natural antioxidants on general acceptance of frozen beef burger

    International Nuclear Information System (INIS)

    The effect of addition of rosemary and oregano extracts on the sensory quality of irradiated beef burger was investigated. Batches of beef burgers were prepared with 400 ppm of rosemary or oregano extract and a group prepared with 200 ppm of synthetic butyl-hydroxytoluene (BHT)/butyl-hydroxy-anisol (BHA) was used as a control. Half of each formulation was irradiated at the maximum dose allowed for frozen meat (7 kGy). Samples were kept under frozen conditions (-20 deg. C) during the whole storage period, including during irradiation. Two analyses were performed after 20 and 90 days to verify the influence of the addition of the different types of antioxidants and the effect of irradiation and storage time on the acceptance of the product. Thirty-three and thirty-four untrained panelists were invited to participate in the first and second test, respectively. A structured hedonic scale ranging from 1 to 9 points was used in both analyses. BHT/BHA formulation obtained the highest score (6.73) and regarding the natural antioxidants, oregano received better acceptance (6.36). Irradiated samples formulated with oregano received a lower score, 6.03 in the first test and 5.06 in the second one, compared to the non-irradiated sample (6.36 and 5.79). In the second test (90 days), the sample formulated with BHT/BHA and which was irradiated received a higher score (6.59) when compared to the non-irradiated one (5.85). In both tests, the irradiated samples formulated with rosemary extract obtained a better score compared to the non-irradiated one, the scores being 5.00-3.82 and 5.00-3.76 in the first and second test, respectively. Our results allowed us to conclude that the natural antioxidants, rosemary and oregano extracts, present a good alternative for replacing synthetic additives in food industries, and that the irradiation process, in some cases, may help to enhance the sensory quality of food

  3. Competing 1πσ* mediated dynamics in mequinol: O-H versus O-CH3 photodissociation pathways.

    Science.gov (United States)

    Hadden, David J; Roberts, Gareth M; Karsili, Tolga N V; Ashfold, Michael N R; Stavros, Vasilios G

    2012-10-14

    along the O-H coordinate generally mimic H atom elimination previously observed in phenol, whereas O-CH(3) bond fission in mequinol appears to present notably different behavior to the CH(3) elimination dynamics previously observed in anisole (methoxybenzene). PMID:22948565

  4. Anthropogenic and naturally produced brominated substances in Baltic herring (Clupea harengus membras) from two sites in the Baltic Sea.

    Science.gov (United States)

    Dahlberg, Anna-Karin; Bignert, Anders; Legradi, Jessica; Legler, Juliette; Asplund, Lillemor

    2016-02-01

    In the eutrophicated Baltic Sea, several naturally produced hydroxylated polybrominated diphenyl ethers (OH-PBDEs) have been found in marine biota. OH-PBDEs are toxic to adult and developing zebrafish and shown to be potent disruptors of oxidative phosphorylation (OXPHOS). Disturbed OXPHOS can result in altered energy metabolism and weight loss. In herring, the concentration of OH-PBDEs (i.e. 2'-OH-BDE68 and 6-OH-BDE47) has increased during the period 1980-2010 in the Baltic Proper. Over the same time period, the condition and fat content in Baltic herring have decreased. Given the toxicity and increasing trends of OH-PBDEs in Baltic herring it is important to further assess the exposure to OH-PBDEs in Baltic herring. In this study, the concentrations of OH-PBDEs and related brominated substances i.e. polybrominated phenols (PBPs), polybrominated anisoles (PBAs), methoxylated polybrominated diphenyl ethers (MeO-PBDEs) and polybrominated diphenyl ethers (PBDEs) were measured in herring sampled in the northern Baltic Proper (Askö, n = 12) and the southern Bothnian Sea (Ängskärsklubb, n = 12). The geometric mean (GM) concentrations (ng/g l.w.) at Askö and Ängskärsklubb were; Σ2PBPs: 4.3 and 9.6, Σ(2)PBAs: 34 and 20, Σ(6)OH-PBDEs: 9.4 and 10, Σ(7)MeO-PBDEs: 42 and 150, Σ(6)PBDEs: 54 and 27, respectively. 6-OH-BDE47 dominated the OH-PBDE profile and comprised 87% (Askö) and 91% (Ängskärsklubb) of the ΣOH-PBDEs. At Ängskärsklubb the mean concentration of ΣMeO-PBDEs (150 ng/g l.w.) was 15 times higher than ΣOH-PBDEs. As other fish species are known to metabolically transform MeO-PBDEs to OH-PBDEs, high levels of MeO-PBDEs can be of concern as a precursor for more toxic OH-PBDEs in herring and their roe. PMID:26613358

  5. A mechanistic analysis of the Birch Reduction.

    Science.gov (United States)

    Zimmerman, Howard E

    2012-02-21

    The Birch Reduction is one of the main reactions of organic chemistry. The reaction involves the reaction of dissolving metals in ammonia with aromatic compounds to produce 1,4-cyclohexadienes. Discovered by Arthur Birch in 1944, the reaction occupies 300 pages in Organic Reactions to describe its synthetic versatility. Thus, it is remarkable that the reaction mechanism has been so very controversial and only relatively recently has been firmly established. Perhaps this is not that surprising, since the reaction also has many unusual and esoteric mechanistic facets. Here, I provide a description of how I have applied ever-evolving levels of quantum mechanics and a novel experimental test to understand details of the mechanism and the origins of the selectivities observed in the Birch reduction. The reaction involves an initial radical anion resulting from introduction of an electron from the blue liquid ammonia solution of free electrons formed by the dissolution of Li or related metals. This radical anion is protonated by an alcohol and then further reduced to a carbanion. Finally, the carbanion is protonated using a second proton to afford a nonconjugated cyclohexadiene. The regiochemistry depends on substituents present. With 18 resonance structures in the case of anisole radical anion, prediction of the initial protonation site would seem difficult. Nevertheless, computational methods from Hückel theory through modern density functional calculations do correctly predict the site of protonation. An esoteric test established this mechanism experimentally. The nature of the carbanion also is of mechanistic interest, and the preponderance of the resonance structure shown was revealed from Hückel calculations involving variable bond orders. For the trianion from benzoic acid, parallel questions about structure are apparent, and have been answered. Some mechanistic questions are answered experimentally and some by modern computations. Recently, our mechanistic

  6. Consumer's evaluation of the effects of gamma irradiation and natural antioxidants on general acceptance of frozen beef burger

    Energy Technology Data Exchange (ETDEWEB)

    Trindade, R.A. [Instituto de Pesquisas Energeticas e Nucleares, IPEN-CNEN/SP, Centro de Tecnologia das Radiacoes, Lab. de Deteccao de Alimentos Irradiados, Travessa R, 400, Cidade Universitaria, 05508-900 Sao Paulo (Brazil)], E-mail: rtrindade@usp.br; Lima, A.; Andrade-Wartha, E.R.; Oliveira e Silva, A.M.; Mancini-Filho, J. [Faculdade de Ciencias Farmaceuticas, FCF/USP, Departamento de Alimentos e Nutricao Experimental-Lab. de Lipides. Av. Prof. Lineu Prestes, 580 Bloco 14, 05508-900 Sao Paulo (Brazil); Villavicencio, A.L.C.H. [Instituto de Pesquisas Energeticas e Nucleares, IPEN-CNEN/SP, Centro de Tecnologia das Radiacoes, Lab. de Deteccao de Alimentos Irradiados, Travessa R, 400, Cidade Universitaria, 05508-900 Sao Paulo (Brazil)], E-mail: villavic@ipen.br

    2009-04-15

    The effect of addition of rosemary and oregano extracts on the sensory quality of irradiated beef burger was investigated. Batches of beef burgers were prepared with 400 ppm of rosemary or oregano extract and a group prepared with 200 ppm of synthetic butyl-hydroxytoluene (BHT)/butyl-hydroxy-anisol (BHA) was used as a control. Half of each formulation was irradiated at the maximum dose allowed for frozen meat (7 kGy). Samples were kept under frozen conditions (-20 deg. C) during the whole storage period, including during irradiation. Two analyses were performed after 20 and 90 days to verify the influence of the addition of the different types of antioxidants and the effect of irradiation and storage time on the acceptance of the product. Thirty-three and thirty-four untrained panelists were invited to participate in the first and second test, respectively. A structured hedonic scale ranging from 1 to 9 points was used in both analyses. BHT/BHA formulation obtained the highest score (6.73) and regarding the natural antioxidants, oregano received better acceptance (6.36). Irradiated samples formulated with oregano received a lower score, 6.03 in the first test and 5.06 in the second one, compared to the non-irradiated sample (6.36 and 5.79). In the second test (90 days), the sample formulated with BHT/BHA and which was irradiated received a higher score (6.59) when compared to the non-irradiated one (5.85). In both tests, the irradiated samples formulated with rosemary extract obtained a better score compared to the non-irradiated one, the scores being 5.00-3.82 and 5.00-3.76 in the first and second test, respectively. Our results allowed us to conclude that the natural antioxidants, rosemary and oregano extracts, present a good alternative for replacing synthetic additives in food industries, and that the irradiation process, in some cases, may help to enhance the sensory quality of food.

  7. Consumer's evaluation of the effects of gamma irradiation and natural antioxidants on general acceptance of frozen beef burger

    Science.gov (United States)

    Trindade, R. A.; Lima, A.; Andrade-Wartha, E. R.; Oliveira e Silva, A. M.; Mancini-Filho, J.; Villavicencio, A. L. C. H.

    2009-04-01

    The effect of addition of rosemary and oregano extracts on the sensory quality of irradiated beef burger was investigated. Batches of beef burgers were prepared with 400 ppm of rosemary or oregano extract and a group prepared with 200 ppm of synthetic butyl-hydroxytoluene (BHT)/butyl-hydroxy-anisol (BHA) was used as a control. Half of each formulation was irradiated at the maximum dose allowed for frozen meat (7 kGy). Samples were kept under frozen conditions (-20 °C) during the whole storage period, including during irradiation. Two analyses were performed after 20 and 90 days to verify the influence of the addition of the different types of antioxidants and the effect of irradiation and storage time on the acceptance of the product. Thirty-three and thirty-four untrained panelists were invited to participate in the first and second test, respectively. A structured hedonic scale ranging from 1 to 9 points was used in both analyses. BHT/BHA formulation obtained the highest score (6.73) and regarding the natural antioxidants, oregano received better acceptance (6.36). Irradiated samples formulated with oregano received a lower score, 6.03 in the first test and 5.06 in the second one, compared to the non-irradiated sample (6.36 and 5.79). In the second test (90 days), the sample formulated with BHT/BHA and which was irradiated received a higher score (6.59) when compared to the non-irradiated one (5.85). In both tests, the irradiated samples formulated with rosemary extract obtained a better score compared to the non-irradiated one, the scores being 5.00-3.82 and 5.00-3.76 in the first and second test, respectively. Our results allowed us to conclude that the natural antioxidants, rosemary and oregano extracts, present a good alternative for replacing synthetic additives in food industries, and that the irradiation process, in some cases, may help to enhance the sensory quality of food.

  8. Thermal Decomposition Mechanisms of Lignin Model Compounds: From Phenol to Vanillin

    Science.gov (United States)

    Scheer, Adam Michael

    Lignin is a complex, aromatic polymer abundant in cellulosic biomass (trees, switchgrass etc.). Thermochemical breakdown of lignin for liquid fuel production results in undesirable polycyclic aromatic hydrocarbons that lead to tar and soot byproducts. The fundamental chemistry governing these processes is not well understood. We have studied the unimolecular thermal decomposition mechanisms of aromatic lignin model compounds using a miniature SiC tubular reactor. Products are detected and characterized using time-of-flight mass spectrometry with both single photon (118.2 nm; 10.487 eV) and 1 + 1 resonance-enhanced multiphoton ionization (REMPI) as well as matrix isolation infrared spectroscopy. Gas exiting the heated reactor (300 K--1600 K) is subject to a free expansion after a residence time of approximately 100 micros. The expansion into vacuum rapidly cools the gas mixture and allows the detection of radicals and other highly reactive intermediates. By understanding the unimolecular fragmentation patterns of phenol (C6H5OH), anisole (C6H 5OCH3) and benzaldehyde (C6H5CHO), the more complicated thermocracking processes of the catechols (HO-C 6H4-OH), methoxyphenols (HO-C6H4-OCH 3) and hydroxybenzaldehydes (HO-C6H4-CHO) can be interpreted. These studies have resulted in a predictive model that allows the interpretation of vanillin, a complex phenolic ether containing methoxy, hydroxy and aldehyde functional groups. This model will serve as a guide for the pyrolyses of larger systems including lignin monomers such as coniferyl alcohol. The pyrolysis mechanisms of the dimethoxybenzenes (H3C-C 6H4-OCH3) and syringol, a hydroxydimethoxybenzene have also been studied. These results will aid in the understanding of the thermal fragmentation of sinapyl alcohol, the most complex lignin monomer. In addition to the model compound work, pyrolyisis of biomass has been studied via the pulsed laser ablation of poplar wood. With the REMPI scheme, aromatic lignin decomposition

  9. Hydroxylation of aromatics with the help of a non-haem FeOOH: a mechanistic study under single-turnover and catalytic conditions.

    Science.gov (United States)

    Thibon, Aurore; Jollet, Véronique; Ribal, Caroline; Sénéchal-David, Katell; Billon, Laurianne; Sorokin, Alexander B; Banse, Frédéric

    2012-02-27

    Ferric-hydroperoxo complexes have been identified as intermediates in the catalytic cycle of biological oxidants, but their role as key oxidants is still a matter of debate. Among the numerous synthetic low-spin Fe(III)(OOH) complexes characterized to date, [(L(5)(2))Fe(OOH)](2+) is the only one that has been isolated in the solid state at low temperature, which has provided a unique opportunity for inspecting its oxidizing properties under single-turnover conditions. In this report we show that [(L(5)(2))Fe(OOH)](2+) decays in the presence of aromatic substrates, such as anisole and benzene in acetonitrile, with first-order kinetics. In addition, the phenol products are formed from the aromatic substrates with similar first-order rate constants. Combining the kinetic data obtained at different temperatures and under different single-turnover experimental conditions with experiments performed under catalytic conditions by using the substrate [1,3,5-D(3)]benzene, which showed normal kinetic isotope effects (KIE>1) and a notable hydride shift (NIH shift), has allowed us to clarify the role played by Fe(III)(OOH) in aromatic oxidation. Several lines of experimental evidence in support of the previously postulated mechanism for the formation of two caged Fe(IV)(O) and OH(·) species from the Fe(III)(OOH) complex have been obtained for the first time. After homolytic O-O cleavage, a caged pair of oxidants [Fe(IV)O+HO(·)] is generated that act in unison to hydroxylate the aromatic ring: HO(·) attacks the ring to give a hydroxycyclohexadienyl radical, which is further oxidized by Fe(IV)O to give a cationic intermediate that gives rise to a NIH shift upon ketonization before the final re-aromatization step. Spin-trapping experiments in the presence of 5,5-dimethyl-1-pyrroline N-oxide and GC-MS analyses of the intermediate products further support the proposed mechanism. PMID:22290835

  10. 磷钨酸原位改性HMS催化苯甲醚乙酰化反应%Catalytic Synthesis of p-Methoxy Acetophenone with Modification Catalyst HMS by Phosphotungstic Acid

    Institute of Scientific and Technical Information of China (English)

    周晓; 张亚洲; 王伟; 刘向东; 陈平

    2013-01-01

    The modification solid catalyst HMS by phosphotungstic acid was prepared by in-situ synthesis from DDA,TEOS,and phosphotungstic acid,and applied in p-Methoxy acetophenone production with the Friedel-Crafts acylation reaction of phenyl methyl ether and Acetic anhydride.The factors including reaction temperature,reaction time,catalyst amount,reactants molar ratio phenyl methyl ether to Acetic anhydride on the Friedel-Crafts acylation reaction were investigated.The experimental effects show that solid acid catalyst HMS has high catalytic activity.The acylation reaction conversion can reach 83.1% and the selectivity of p-Methoxy acetophenone production is 97.3% under the following optimal conditions:reaction temperature of 100 ℃,reaction time of 4 h,amount catalyst of 0.15 g,molar ratio of n(anisole) ∶ n(acetic anhydride) =1 ∶1.5.%以正十二胺(DDA)为模板剂、正硅酸四乙酯(TEOS)为硅源、磷钨酸(HPW)为活性组分,经原位合成法制备了HPW改性的介孔材料HMS(HPW-HMS),并以此催化剂催化苯甲醚与乙酸酐发生傅-克(Friedel-Crafts)酰基化反应合成对甲氧基苯乙酮,对催化剂进行了XRD和IR表征,研究了催化剂制备方法、脱除模板剂的方式以及催化反应条件,考察反应温度、反应时间、催化剂质量、反应物的物质的量等对苯甲醚转化率和主产物对甲氧基苯乙酮选择性的影响.实验结果表明,固体催化剂HPW-HMS在此反应中具有较高的催化活性,当反应温度100℃,反应时间4h,催化剂质量0.15g,原料物质的量比n(苯甲醚)∶n(乙酸酐)=1∶1.5时,苯甲醚转化率达到83.1%,对甲氧基苯乙酮选择性达97.3%.

  11. The Thermodynamic Properties and Homogeneous Catalysts for the Synthesis of Diphenyl Carbonate by Transesterification of Dimethyl Carbonate with Phenol%碳酸二甲酯与苯酚酯交换合成碳酸二苯酯的热力学性质及均相催化剂

    Institute of Scientific and Technical Information of China (English)

    梅付名; 李光兴

    2003-01-01

    The Gibbs free energy of formation and entropy of liquid dimethyl carbonate(DMC) at 298.15K and 101.325kPa were estimated to be -472.3 kJ*mol-1 and 245.2 J*mol-1*K-1 respectively. The thermodynamic properties (ΔrH0m,ΔrS0m,ΔrG0m and equilibrium constant) of the reactions for the production of diphenyl carbonate(DPC) and anisole between DMC and phenol from 298K to 523K were calculated. These values indicated that the reaction of transesterification of DMC with phenol to DPC was endothermic and thermodynamically unfavorable. n-Bu2SnO, Ti(OC4H9)4, AlCl3 and ZnCl2 were tested to catalyze the synthesis of DPC by transesterification of DMC with phenol. n-Bu2SnO had the highest catalytic activity among them. The optimum temperature was 453K for the synthesis of DPC. When the molar ratio of phenol to dimethyl carbonate was 4∶1, the yield and selectivity of DPC were 43.0% and 88.7% respectively using n-Bu2SnO as a catalyst.%在298.15K,101.325kPa条件下,液态碳酸二甲酯(DMC)的标准Gibbs自由能和熵分别估算为-472.3kJ*mol-1和245.2J*mol-1*K-1.在298K~523K计算了由DMC和苯酚生成碳酸二苯酯(DPC)和苯甲醚反应的热力学性质(ΔrH0m,ΔrS0m,ΔrG0m和平衡常数).计算出的热力学性质表明,DMC和苯酚酯交换合成DPC反应是吸热的,并且在热力学上是不利的.研究了n-Bu2SnO, Ti(OC4H9)4, AlCl3和ZnCl2四种酯交换法合成DPC反应的催化剂,其中n-Bu2SnO具有最高的催化活性.热力学计算和实验结果均表明,合成DPC反应的最佳温度为453K.当以n-Bu2SnO为催化剂,n(苯酚)∶n(DMC)=4∶1时,DPC的产率和选择性分别为43.0%和88.7%.

  12. Fracture-induced mechanophore activation and solvent healing in poly(methyl methacrylate)

    Science.gov (United States)

    Celestine, Asha-Dee N.

    of the crack tip. Control specimens in which the mechanophore is absent or tethered in positions in which no mechanochemical activation is expected are also tested and exhibit no change in color or fluorescence intensity with crack propagation. The relationship between fracture-induced mechanophore activation in rubber toughened SP-PMMA and the strain and stress ahead of the propagating crack is also studied. SP activation is again detected and quantified by in situ fluorescence imaging. Digital Image Correlation (DIC) is used to measure the strain ahead of the crack tip. The corresponding stress is generated through the use of the Hutchinson-Rice-Rosengren (HRR) singularity field equations. Mechanophore activation ahead of the crack tip is shown to follow a power law distribution that is closely aligned with strain. The potential of SP as a damage sensor is explored further by incorporating the spiropyran into the core of rubber nanoparticles. SP-linked rubber nanoparticles are synthesized using a seeded emulsion polymerization process and incorporated into cross-linked PMMA at a concentration of 5 wt%. Cylindrical specimens are torsion tested and the activation of the SP within the nanoparticles is monitored via full field fluorescence imaging. SP activation within the core is shown to increase with shear strain. Autonomous damage repair in PMMA is also investigated. The first demonstration of fully autonomous self-healing in PMMA is achieved through the use of solvent microcapsules. Solvent microcapsules with a PMMA-anisole liquid core are prepared and embedded within a linear PMMA matrix. Specimens of the microcapsule-loaded material are then fabricated for Double Cleavage Drilled Compression (DCDC) fracture testing. The DCDC specimens, containing increasing concentrations of solvent microcapsules, are tested and then allowed to heal for a fixed period of time before a second DCDC test. The healing efficiency of each material system is evaluated based on the

  13. Half-sandwich rare-earth-catalyzed olefin polymerization, carbometalation, and hydroarylation.

    Science.gov (United States)

    Nishiura, Masayoshi; Guo, Fang; Hou, Zhaomin

    2015-08-18

    -site catalysts. This Account is intended to give an overview of our recent studies on organo rare-earth catalysis, in particular the synthesis and application of half-sandwich rare-earth alkyl complexes bearing monocyclopentadienyl ligands for olefin polymerization, carbometalation, and hydroarylation. Treatment of half-sandwich rare-earth dialkyl complexes having the general formula CpMR2 with an equimolar amount of an appropriate borate compound such as [Ph3C][B(C6F5)4] can generate the corresponding cationic monoalkyl species, which serve as excellent single-site catalysts for the polymerization and copolymerization of a wide range of olefin monomers such as ethylene, 1-hexene, styrene, conjugated and nonconjugated dienes, and cyclic olefins. The cationic half-sandwich rare-earth alkyl complexes can also catalyze the regio- and stereoselective alkylative alumination of alkenes and alkynes through insertion of the unsaturated C-C bond into the metal-alkyl bond followed by transmetalation between the resulting new alkyl or alkenyl species and an alkylaluminum compound. Moreover, a combination of deprotonative C-H bond activation of appropriate organic compounds such as anisoles and pyridines by the rare-earth alkyl species and insertion of alkenes into the resulting new metal-carbon bond can lead to catalytic C-H bond alkylation of the organic substrates. Most of these transformations are unique to the rare-earth catalysts with selectivity and functional group tolerance different from those of late-transition-metal catalysts. PMID:26214733

  14. Activation and deactivation of neutral palladium(II) phosphinesulfonato polymerization catalysts

    KAUST Repository

    Rünzi, Thomas

    2012-12-10

    polymerization filtrates indicate the presence of (odd- and even-numbered alkyl)(anisyl)phosphine sulfonates (14) and their respective phosphine oxides (15). Furthermore, 2-(vinyl)anisole was detected in NMR tube and reactor polymerizations, which results from ethylene insertion into a palladium-anisyl bond and concomitant β-hydride elimination. In addition to these scrambling reactions, formation of alkanes or fully saturated polymer chains, bis(chelate)palladium complexes [κ2-P,O]2Pd, and palladium black was identified as an irreversible catalyst deactivation pathway. This deactivation proceeds by reaction of palladium alkyl complexes with palladium hydride complexes [κ2-P,O]Pd(H)(L) or by reaction with the free ligand H[P,O] generated by reductive elimination from [κ2-P,O]Pd(H)(L). The model hydride complex 1-H-P tBu3 has been synthesized in order to establish whether 1-H-PtBu3 or H[P,O] is responsible for the irreversible catalyst deactivation. However, upon reaction with 1-(13)CH 3-L or 1-CH2CH3-PPh3, both 1-H-PtBu3 and H[P,O] result in formation of methane or ethane, even though H[P,O] reacts faster than 1-H-PtBu3. DFT calculations show that reductive elimination to form H[P,O] and (alkyl)[P,O] from 1-H/(alkyl)-PtBu3 is kinetically accessible, as is the oxidative readdition of the P-H bond of H[P,O] and the P-anisyl bond of (alkyl)[P,O] to [Pd(PtBu3)2]. These calculations also indicate that for a reaction sequence comprising reductive elimination of H[P,O] from 1-H-PtBu3 and reaction of H[P,O] with 1-CH3-PtBu3, 1-CH3-dmso, or 1-CH2CH3-PPh3 to form methane or ethane, the rate-limiting step is reductive elimination of H[P,O] with a barrier of 124 kJ mol-1. However, a second reaction coordinate was found for the reaction of 1-H-PtBu3 with 1-CH3-P tBu3 or 1-CH3-dmso, which evolves into bimetallic transition-state geometries with a nearly linear H-(CH 3)-Pd alignment and which exhibits a barrier of 131 or 95 kJ mol -1 for the formation of methane. © 2012 American Chemical

  15. Catalytic hydrothermal gasification of biomass for the production of synthetic natural gas[Dissertation 17100

    Energy Technology Data Exchange (ETDEWEB)

    Waldner, M. H.

    2007-07-01

    , phenol, and anisole) that approximates hydrolyzed wood served as feed. The skeletal nickel catalysts turned out to be active but not stable, as they deactivated within a few hours. The attempt to stabilize them by co-doping of other metals (Ru, Mo, Cu) was not successful. Ru/TiO{sub 2} was not active enough, but Ru/C completely gasified the mixture at high space velocities over a period of more than 200 hours; the product gas composition corresponded at all times to the thermodynamic equilibrium composition. This catalyst was tested for its tolerance towards sulfate, which turned out to be low: the addition of a few ppm to the feed led to a deactivation within hours. The deactivation mechanism was identified as chemical poisoning. The poisoning species which is present in situ in the hydrothermal environment (sulfate vs. sulfide) is not clear. The experimental evidence can be explained by both hypotheses. A heating system for quartz capillaries rendered the visual examination of hydrothermal processes possible. Due to the required low amounts of feed material (a few hundred milligrams) and frequent capillary explosions, the usage of the system was discontinued. The conveying of solid containing slurries on the laboratory scale turned out to remain an unsolved problem. Thus, only liquid type biomass can be fed with the process demonstration unit that was built. A suitable feedstock was found with palm oil pyrolysis condensate, a problematic waste stream very common in Indonesia, that has a high organic content (exceeding 40 wt %). Preliminary gasification experiments with ethanol and salt separation experiments with sodium sulfate were successful. (author)