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Sample records for aliphatic dimethylarsinoyl compounds

  1. ANAEROBIC AND AEROBIC TREATMENT OF CHLORINATED ALIPHATIC COMPOUNDS

    EPA Science Inventory

    Biological degradation of 12 chlorinated aliphatic compounds (CACs) was assessed in bench-top reactors and in serum bottle tests. Three continuously mixed daily batch-fed reactor systems were evaluated: anaerobic, aerobic, and sequential-anaerobic-aerobic (sequential). Glucose,...

  2. ANAEROBIC AND AEROBIC TREATMENT OF CHLORINATED ALIPHATIC COMPOUNDS

    EPA Science Inventory

    Biological degradation of 12 chlorinated aliphatic compounds (CACs) was assessed in bench-top reactors and in serum bottle tests. Three continuously mixed daily batch-fed reactor systems were evaluated: anaerobic, aerobic, and sequential-anaerobic-aerobic (sequential). Glucose,...

  3. Biodegradation of Trihalomethanes and Other Halogenated Aliphatic Compounds

    NASA Technical Reports Server (NTRS)

    Smith, G. B.

    1996-01-01

    The biological dehalogenation of common water pollutants such as trichloromethane (chloroform) and other halogenated aliphatic compounds was the subject of this project. Samples from diverse water environments such as from groundwater contaminated with halogenated compounds and wastewaters from regional treatment plants were studied to identify conditions that favor certain dehalogenation reactions over others. Gene probe analyses of DNA extracted from the dichlormethane-degrading wastewater indicated the presence of the gene coding for dichloromethane dehalogenase, indicating the genetic basis for the dechlorination activity observed. These studies indicate that methanogenic bacteria are the organisms responsible for the chloroform dechlorination. Dechlorination of a common chlorofluorocarbon (CFC-11) was identified in samples taken from a regional aquifer contaminated with halogenated aliphatic compounds.

  4. Lipstick dermatitis due to C18 aliphatic compounds.

    PubMed

    Hayakawa, R; Matsunaga, K; Suzuki, M; Arima, Y; Ohkido, Y

    1987-04-01

    An 18-year-old girl developed cheilitis. She had a past history of lip cream dermatitis, but the cause was not found. Patch tests with 2 lipsticks were strongly positive. Tests with the ingredients were positive to 2 aliphatic compounds, glyceryl diisostearate and diisostearyl malate. Impurities in the materials were suspected as the cause. Analysis by gas chromatography detected 3 chemicals in glyceryl diisostearate and 1 in diisostearyl malate as impurities. Patch testing with the impurities and glyceryl monoisostearate 0.01% pet in glyceryl diisostearate and isostearyl alcohol 0.25% pet in diisostearyl malate were strongly positive. The characteristics common to the 2 chemicals were liquidity at room temperature, branched C18 aliphatic compound and primary alcohol. Chemicals lacking any of the above 3 features did not react.

  5. Biotransformation of chlorinated aliphatic compounds by mixed nitrifying cultures

    SciTech Connect

    Wilber, G.G.; Chakkamadathil, S.V.

    1995-12-31

    The ability of pure cultures of nitrifying bacteria, such as Nitrosomonas europaea, to oxidize chlorinated aliphatic compounds has been demonstrated previously in laboratory experiments. In the current study, mixed nitrifying cultures originating from a municipal wastewater plant were also tested for the ability to biotransform chlorinated aliphatic compounds, including trichloroethene (TCE). A number of variables were tested, including the effects of two different concentrations of TCE, the effect of culture density, and the influence of the primary substrate, ammonia, on the initial rate of TCE biotransformation. The primary conclusions of the research include the following. The mixed nitrifying cultures did exhibit the ability to transform TCE, and the initial rate of transformation (before oxygen limitations became significant) was directly proportional to the culture density. In general, the transformation rate of TCE was slightly faster at an initial concentration of 0.1 mg/L than at 1 mg/L. Lastly, high initial ammonia concentrations (300 mg/L) resulted in faster initial rates of TCE transformation than in cultures which started with lower ammonia concentrations.

  6. Interaction of gaseous aromatic and aliphatic compounds in thermophilic biofilters.

    PubMed

    Hu, Qing-yuan; Wang, Can

    2015-12-30

    Two thermophilic biofilters were applied in treating a mixture of gaseous aromatic (benzene) and aliphatic compounds (hexane) to evaluate the interaction of the compounds. The performance of the biofilters was investigated in terms of removal efficiencies, elimination capacity, kinetic analysis, interaction indices, and microbial metabolic characteristics. Results showed that the removal performance of benzene was unaffected by the addition of hexane. The removal efficiencies of benzene were maintained at approximately 80% and the biodegradation rate constant was maintained at 120 h(-1). However, the removal efficiencies of hexane decreased significantly from 60% to 20% and the biodegradation rate constant exhibited a distinct decrease from 93.59 h(-1) to 56.32 h(-1). The interaction index of benzene with the addition of hexane was -0.029, which indicated that hexane had little effect on the degradation of benzene. By contrast, the interaction index of hexane by benzene was -0.557, which showed that benzene inhibited the degradation of hexane significantly. Similar conclusions were obtained about the substrate utilization. Moreover, the utilization degree of carbon sources and the microbial metabolic activities in the biofilter treating hexane were significantly improved with the addition of benzene, whereas the addition of hexane had a slight effect on the microbial communities in the biofilter treating benzene. Conclusions could be obtained that when mixtures of benzene and hexane were treated using biofilters, the degradation of benzene, which was more easily degradable, was dominant and unaffected; whereas the degradation of hexane, which was less easily degradable, was inhibited because of the changing of microbes. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Process for removing halogenated aliphatic and aromatic compounds from petroleum products

    DOEpatents

    Googin, J.M.; Napier, J.M.; Travaglini, M.A.

    1983-09-20

    A process is described for removing halogenated aliphatic and aromatic compounds, e.g., polychlorinated biphenyls, from petroleum products by solvent extraction. The halogenated aliphatic and aromatic compounds are extracted from a petroleum product into a polar solvent by contacting the petroleum product with the polar solvent. The polar solvent is characterized by a high solubility for the extracted halogenated aliphatic and aromatic compounds, a low solubility for the petroleum product and considerable solvent power for polyhydroxy compound. The preferred polar solvent is dimethylformamide. A miscible compound, such as, water or a polyhydroxy compound, is added to the polar extraction solvent to increase the polarity of the polar extraction solvent. The halogenated aliphatic and aromatic compounds are extracted from the highly-polarized mixture of water or polyhydroxy compound and polar extraction solvent into a low polar or nonpolar solvent by contacting the water or polyhydroxy compound-polar solvent mixture with the low polar or nonpolar solvent. The halogenated aliphatic and aromatic compounds and the low polar or nonpolar solvent are separated by physical means, e.g., vacuum evaporation. The polar and nonpolar solvents are recovered from recycling. The process can easily be designed for continuous operation. Advantages of the process include that the polar solvent and a major portion of the nonpolar solvent can be recycled, the petroleum products are reclaimable and the cost for disposing of waste containing polychlorinated biphenyls is significantly reduced. 1 fig.

  8. Process for removing halogenated aliphatic and aromatic compounds from petroleum products

    DOEpatents

    Googin, John M.; Napier, John M.; Travaglini, Michael A.

    1983-01-01

    A process for removing halogenated aliphatic and aromatic compounds, e.g., polychlorinated biphenyls, from petroleum products by solvent extraction. The halogenated aliphatic and aromatic compounds are extracted from a petroleum product into a polar solvent by contacting the petroleum product with the polar solvent. The polar solvent is characterized by a high solubility for the extracted halogenated aliphatic and aromatic compounds, a low solubility for the petroleum product and considerable solvent power for polyhydroxy compound. The preferred polar solvent is dimethylformamide. A miscible compound, such as, water or a polyhydroxy compound, is added to the polar extraction solvent to increase the polarity of the polar extraction solvent. The halogenated aliphatic and aromatic compounds are extracted from the highly-polarized mixture of water or polyhydroxy compound and polar extraction solvent into a low polar or nonpolar solvent by contacting the water or polyhydroxy compound-polar solvent mixture with the low polar or nonpolar solvent. The halogenated aliphatic and aromatic compounds and the low polar or nonpolar solvent are separated by physical means, e.g., vacuum evaporation. The polar and nonpolar solvents are recovered from recycling. The process can easily be designed for continuous operation. Advantages of the process include that the polar solvent and a major portion of the nonpolar solvent can be recycled, the petroleum products are reclaimable and the cost for disposing of waste containing polychlorinated biphenyls is significantly reduced.

  9. Organochlorine compounds and aliphatic hydrocarbons in Pacific walrus blubber.

    PubMed

    Seagars, D J; Garlich-Miller, J

    2001-01-01

    Blubber samples were collected from 8 male and 19 female Pacific walrus (Odobenus rosmarus divergens) taken during a 1991 joint USA/USSR cruise traveling widely through the Bering Sea. Dieldrin was found at a level similar to that reported 10 years earlier; oxychlordane was found at a slightly higher concentration than reported previously (Taylor et aL, 1989). Heptachlor epoxide was detected for the first time and found at a low concentration. An initial testing for alpha-, beta- and gamma-HCH detected concentrations similar to those in other Bering Sea pinnipeds. Mean summation of PCB was 0.45 microg g(-1) wet weight in males and 0.16 microg g(-1) in females; only one sample was > 1 microg g(-1). Traces of aliphatic hydrocarbons were detected in all sampled animals, only pristane (x = 0.48 microg g(-1)) was found in concentrations > 1 microg g(-1). Small sample sizes, a lack of samples from immature animals, and uniformly low concentrations of contaminants precluded meaningful analysis of age-related effects and regional differences.

  10. A comprehensive evaluation of the toxicology of cigarette ingredients: aliphatic carbonyl compounds.

    PubMed

    Coggins, Christopher R E; Jerome, Ann M; Edmiston, Jeffery S; Oldham, Michael J

    2011-06-01

    Aliphatic carbonyl compounds are used as ingredients in cigarette tobacco or cigarette filters. A battery of tests was used to compare toxicity of mainstream smoke from experimental cigarettes containing 15 aliphatic carbonyl compounds that were added individually to experimental cigarettes at three different levels. Smoke from experimental and control cigarettes were evaluated using analytical chemistry, in vitro cytotoxicity (neutral red uptake), and mutagenicity (five bacterial strains) studies. For one compound, glycerol triacetate (GTA), two 90-day inhalation studies were also performed, using different inclusion levels into either tobacco or cigarette filter. Several smoke constituent concentrations were reduced with the highest inclusion level of GTA in tobacco; incorporation of GTA into the filter, and the other compounds into tobacco, produced effectively no changes. Cytotoxicity was reduced by the highest inclusion of GTA into tobacco for both gas-vapor and particulate phases of smoke; incorporation of GTA into the filter, and the other compounds into tobacco, showed no changes. Mutagenicity was reduced by the middle and high inclusion levels of GTA into tobacco (TA1537 strain with S9); incorporation of GTA into the filter, and the other compounds into tobacco, showed no changes. Inclusion of GTA in tobacco at 100,000 ppm reduced the biological effects of the smoke in the various test systems reported in this study, although inclusion into the filter did not appear to have any major effect on the endpoints studied. The other 14 aliphatic carbonyl compounds that were tested lacked a toxicological response.

  11. Genetic adaptation of bacteria to halogenated aliphatic compounds

    SciTech Connect

    Janssen, D.B.; Ploeg, J.R. van der; Pries, F.

    1995-06-01

    The bacterial degradation and detoxification of chlorinated xenobiotic compounds requires the production of enzymes that are capable of recognizing and converting compounds which do not occur at significant concentrations in nature. We have studied the catabolic route of 1,2-dichloroethane as an example of a pathway for the conversion of such a synthetic compound. In strains of Xanthobacter and Ancylobacter that have been isolated on 1,2-dichloroethane, the first catabolic step is catalyzed by a hydrolytic haloalkane dehalogenase. The enzyme converts 1,2-dichloroethane to 2-chloroethanol but is also active with many other environmentally important haloalkanes such as methylchloride, methylbromide, 1,2-dibromoethane, epichlorohydrin, and 1,3-dichloropropene. Further degradation of 2-chloroethanol proceeds by oxidation to the carboxylic acid and dehalogenation to glycolate. The aldehyde dehydrogenase prevents toxicity of the reactive chloroacetaldehyde that is formed as an intermediate and is necessary for establishing a functional 2-chloroethanol degradative pathway in a strain that is not capable of growth on this compound. 27 refs., 3 figs., 1 tab.

  12. A comprehensive evaluation of the toxicology of cigarette ingredients: aromatic and aliphatic alcohol compounds.

    PubMed

    Coggins, Christopher R E; Frost-Pineda, Kimberly; Smith, Donna C; Oldham, Michael J

    2011-06-01

    Various aromatic and aliphatic alcohol compounds are found in tobacco and tobacco smoke. A battery of tests was used to compare the toxicity of mainstream smoke from experimental cigarettes containing eight aromatic and aliphatic alcohol compounds that were added individually to experimental cigarettes at three different levels. The lowest target inclusion level was 100 ppm and the highest level was 24,400 ppm. Mainstream smoke from each of the cigarette types was evaluated using analytical chemistry and assays to measure in vitro cytotoxicity (neutral red uptake) and Salmonella (five strains) mutagenicity. For three of the compounds (benzyl alcohol, propyl paraben, and rum flavor), 90-day smoke inhalation studies with 6-week recovery periods were also performed using rats. Inclusion of eugenol produced several dose-related reductions in concentrations of selected smoke constituents. Cytotoxicity and mutagenicity were unaffected by any of the test ingredients, except for dose-related reductions in cytotoxicity of the gas vapor phase produced by the inclusion of eugenol. The three smoke inhalation studies showed a few sporadic differences between the groups and there were no differences in the patterns of recovery for any of the ingredients. Despite using exaggerated inclusion levels of the eight aliphatic and aromatic alcohol compounds in experimental cigarettes, there was minimal toxicological response, which is consistent with published reports of studies using mixtures of compounds added to tobacco.

  13. Degradation of halogenated aliphatic compounds by the ammonia-oxidizing bacterium nitrosomonas europaea

    SciTech Connect

    Vannelli, T.; Logan, M.; Arciero, D.M.; Hooper, A.B. )

    1990-04-01

    Suspensions of Nitrosomonas europaea catalyzed the ammonia-stimulated aerobic transformation of the halogenated aliphatic compounds dichloromethane, dibromomethane, trichloromethane (chloroform), bromoethane, 1,2-dibromoethane (ethylene dibromide), 1,1,2-trichloroethane, 1,1,1-trichloroethane, monochloroethylene (vinyl chloride), gem-dichloroethylene, cis- and trans-dichloroethylene, cis-dibromoethylene, trichloroethylene, and 1,2,3-trichloropropane. Tetrachloromethane (carbon tetrachloride), tetrachloroethylene (perchloroethylene), and trans-dibromoethylene were not degraded.

  14. Degradation of halogenated aliphatic compounds by the ammonia-oxidizing bacterium Nitrosomonas europaea

    SciTech Connect

    Vannelli, T.; Logan, M.; Arciero, D.M.; Hooper, A.B.

    1990-01-01

    Suspensions of Nitrosomonas europaea catalyzed the ammonia-stimulated aerobic transformation of the halogenated aliphatic compounds dichloromethane, dibromomethane, trichloromethane (chloroform), bromoethane, 1,2-dibromoethane (ethylene dibromide), 1,1,2-trichloroethane, 1,1,1-trichloroethane, monochloroethylene (vinyl chloride), gem-dichloroethylene, cis- and trans-dichloroethylene, cis-dibromoethylene, trichloroethylene, and 1,2,3-trichloropropane. Tetrachloromethane (carbon tetrachloride), tetrachloroethylene (perchloroethylene), and trans-dibromoethylene were not degraded.

  15. Comprehensive database of Manufactured Gas Plant tars. Part B. Aliphatic and aromatic compounds.

    PubMed

    Gallacher, Christopher; Thomas, Russell; Lord, Richard; Kalin, Robert M; Taylor, Chris

    2017-08-15

    Coal tars are a mixture of organic and inorganic compounds that were produced as a by-product from the manufactured gas and coke making industries. The composition of the tar produced varies depending on many factors; these include the temperature of production and the type of retort used. As different production processes produce different tars, a comprehensive database of the compounds present within coal tars from different production processes is a valuable resource. Such a database would help to understand how their chemical properties differ and what hazards the compounds present within these tars might pose. This study focuses on the aliphatic and aromatic compounds present in a database of 16 different tars from five different production processes. Samples of coal tar were extracted using accelerated solvent extraction (ASE) and derivatised post-extraction using N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) with 1% trimethylchlorosilane (TMCS). The derivatised samples were analysed using two-dimensional gas chromatography combined with time-of-flight mass spectrometry (GCxGC/TOFMS). A total of 198 individual aliphatic and 951 individual aromatic compounds were detected within 16 tar samples produced by five different production processes. The polycyclic aromatic hydrocarbon (PAH) content of coal tars varies greatly depending on the production process used to obtain the tars and this is clearly demonstrated within the results. The aliphatic composition of the tars provided an important piece of analytical information that would have otherwise been missed with the detection of petrogenic compounds such as alkyl cyclohexanes. The aromatic compositions of the tar samples varied greatly between the different production processes investigated and useful analytical information was obtained about the individual production process groups. Alkyl cyclohexanes were detected in all samples from sites known to operate Carbureted Water Gas plants and not detected in

  16. Process for removing halogenated aliphatic and aromatic compounds from petroleum products. [Polychlorinated biphenyls; methylene chloride; perchloroethylene; trichlorofluoroethane; trichloroethylene; chlorobenzene

    DOEpatents

    Googin, J.M.; Napier, J.M.; Travaglini, M.A.

    1982-03-31

    A process for removing halogenated aliphatic and aromatic compounds, e.g., polychlorinated biphenyls, from petroleum products by solvent extraction. The halogenated aliphatic and aromatic compounds are extracted from a petroleum product into a polar solvent by contracting the petroleum product with the polar solvent. The polar solvent is characterized by a high solubility for the extracted halogenated aliphatic and aromatic compounds, a low solubility for the petroleum product and considerable solvent power for polyhydroxy compound. The preferred polar solvent is dimethylformamide. A miscible polyhydroxy compound, such as, water, is added to the polar extraction solvent to increase the polarity of the polar extraction solvent. The halogenated aliphatic and aromatic compounds are extracted from the highly-polarized mixture of polyhydroxy compound and polar extraction solvent into a low polar or nonpolar solvent by contacting the polyhydroxy compound-polar solvent mixture with the low polar or nonpolar solvent. The halogenated aliphatic and aromatic compounds in the low polar or nonpolar solvent by physical means, e.g., vacuum evaporation. The polar and nonpolar solvents are recovered for recycling. The process can easily be designed for continuous operation. Advantages of the process include that the polar solvent and a major portion of the nonpolar solvent can be recycled, the petroleum products are reclaimable and the cost for disposing of waste containing polychlorinated biphenyls is significantly reduced. 2 tables.

  17. Spider monkeys (Ateles geoffroyi) are less sensitive to the odor of aliphatic ketones than to the odor of other classes of aliphatic compounds.

    PubMed

    Eliasson, Moa; Hernandez Salazar, Laura Teresa; Laska, Matthias

    2015-10-01

    Aliphatic ketones are widely present in body-borne and food odors of primates. Therefore, we used an operant conditioning paradigm and determined olfactory detection thresholds in four spider monkeys for a homologous series of aliphatic 2-ketones (2-butanone to 2-nonanone) and two of their isomers (3- and 4-heptanone). We found that, with the exception of the two shortest-chained ketones, all animals detected concentrations <1 ppm (parts per million), and with five odorants individual animals even reached threshold values <0.1 ppm. Further, we found a significant correlation between olfactory sensitivity of the spider monkeys and carbon chain length of the 2-ketones which can best be described as a U-shaped function. In contrast, no significant correlation was found between olfactory sensitivity and position of the functional carbonyl group. Across-odorant and across-species comparisons revealed the following: spider monkeys are significantly less sensitive to the odors of aliphatic ketones than to the odor of other classes of aliphatic compounds (1-alcohols, n-aldehydes, n-acetic esters, and n-carboxylic acids) sharing the same carbon length. Spider monkeys do not differ significantly in their olfactory sensitivity for aliphatic ketones from squirrel monkeys and pigtail macaques, but are significantly less sensitive to these odorants compared to human subjects and mice. These findings support the notion that neuroanatomical and genetic properties do not allow for reliable predictions with regard to a species' olfactory sensitivity. Further, we conclude that the frequency of occurrence of a class of odorants in a species' chemical environment does not allow for reliable predictions of the species' olfactory sensitivity.

  18. Haloacetic acid and trihalomethane formation from the chlorination and bromination of aliphatic beta-dicarbonyl acid model compounds.

    PubMed

    Dickenson, Eric R V; Summers, R Scott; Croué, Jean-Philippe; Gallard, Hervé

    2008-05-01

    While it is known that resorcinol- and phenol-type aromatic structures within natural organic matter (NOM) react during drinking water chlorination to form trihalomethanes (THMs), limited studies have examined aliphatic-type structures as THM and haloacetic acid (HAA) precursors. A suite of aliphatic acid model compounds were chlorinated and brominated separately in controlled laboratory-scale batch experiments. Four and two beta-dicarbonyl acid compounds were found to be important precursors for the formation of THMs (chloroform and bromoform (71-91% mol/mol)), and dihaloacetic acids (DXAAs) (dichloroacetic acid and dibromoacetic acid (5-68% mol/mol)), respectively, after 24 h at pH 8. Based upon adsorbable organic halide formation, THMs and DXAAs, and to a lesser extent mono and trihaloacetic acids, were the majority (> 80%) of the byproducts produced for most of the aliphatic beta-dicarbonyl acid compounds. Aliphatic beta-diketone-acid-type and beta-keto-acid-type structures could be possible fast- and slow-reacting THM precursors, respectively, and aliphatic beta-keto-acid-type structures are possible slow-reacting DXAA precursors. Aliphatic beta-dicarbonyl acid moieties in natural organic matter, particularly in the hydrophilic fraction, could contribute to the significant formation of THMs and DXAAs observed after chlorination of natural waters.

  19. Study of substituent effects for aliphatic CH3-X compounds by resonant Auger spectroscopy.

    PubMed

    Travnikova, Oksana; Svensson, Svante; Céolin, Denis; Bao, Zhuo; Piancastelli, Maria Novella

    2009-02-07

    In this study linear free energy relationships (LFER) are applied to the relaxation of core-excited states in aliphatic CH(3)X compounds. There are at least two valence orbitals involved in Auger decay following C(CH(3))1s -->sigma*(C-X) excitation, which may as well be localized on the substituents in this series. Therefore, the observed property cannot be strictly attached to the so-called reaction center. The behavior of substituent constants in the description of core-hole processes in aliphatic compounds is also checked on C1s ionization potentials for the extended series of substituted methanes. The role of the inductive effect for both resonant Auger kinetic energies (E(k)) and C1s binding energies (E) is very important. C(CH(3))1s -->sigma*(C-X) excitation energies do not show any significant correlations with inductive substituent constants. On the contrary, Taft's inductive parameters alone give good correlations for E(k). A simple model with 'Z + 1' approximation is developed to describe E(k) and explain the observed correlations: [formula: see text] where E(b)(v(Z)) is the valence ionization potential for CH(3)X and E(ea(Z+1)(+)) is the electron affinity for [NH(3)X](+).

  20. A cometabolic biotransformation model for halogenated aliphatic compounds exhibiting product toxicity

    SciTech Connect

    Alvarez-Cohen, L. ); McCarty, P.L. )

    1991-08-01

    A model is proposed to describe the rate and extent of cometabolic transformation of halogenated aliphatic compounds by resting microbial cells. The finite transformation capacity ({Tc}) of resting cells, which appears to be associated with cometabolic oxidation of many halogenated aliphatic compounds, is used to incorporate the effects of product toxicity and reductant supply into a modified expression of Monod kinetics. Applicability of the model of trichloroethylene transformation by resting cells from a mixed methanotrophic culture is evaluated by comparison with experimental data from batch transformation studies conducted over a range of conditions. A visually good and statistically reasonable fit was obtained between the experimental data and model predictions both with cells alone and with formate added as an exogenous reductant source. A comparison of parameter estimates (k and K{sub s}) derived by use of the cometabolic transformation model and those derived by use of conventional linearized Monod techniques (Lineweaver-Burk and concentration-normalized equations) indicates that, for reactions involving a finite transformation capacity, the linearized Monod equations yield artificially elevated parameters estimates.

  1. Boiling points of halogenated aliphatic compounds: a quantitative structure-property relationship for prediction and validation.

    PubMed

    Oberg, Tomas

    2004-01-01

    Halogenated aliphatic compounds have many technical uses, but substances within this group are also ubiquitous environmental pollutants that can affect the ozone layer and contribute to global warming. The establishment of quantitative structure-property relationships is of interest not only to fill in gaps in the available database but also to validate experimental data already acquired. The three-dimensional structures of 240 compounds were modeled with molecular mechanics prior to the generation of empirical descriptors. Two bilinear projection methods, principal component analysis (PCA) and partial-least-squares regression (PLSR), were used to identify outliers. PLSR was subsequently used to build a multivariate calibration model by extracting the latent variables that describe most of the covariation between the molecular structure and the boiling point. Boiling points were also estimated with an extension of the group contribution method of Stein and Brown.

  2. Oxyfunctionalization of aliphatic compounds by a recombinant peroxygenase from Coprinopsis cinerea.

    PubMed

    Babot, Esteban D; del Río, José C; Kalum, Lisbeth; Martínez, Angel T; Gutiérrez, Ana

    2013-09-01

    The goal of this study is the selective oxyfunctionalization of aliphatic compounds under mild and environmentally friendly conditions using a low-cost enzymatic biocatalyst. This could be possible taking advantage from a new peroxidase type that catalyzes monooxygenase reactions with H2 O2 as the only cosubstrate (peroxygenase). With this purpose, recombinant peroxygenase, from gene mining in the sequenced genome of Coprinopsis cinerea and heterologous expression using an industrial fungal host, is tested for the first time on aliphatic substrates. The reaction on free and esterified fatty acids and alcohols, and long-chain alkanes was followed by gas chromatography, and the different reaction products were identified by mass spectrometry. Regioselective hydroxylation of saturated/unsaturated fatty acids was observed at the ω-1 and ω-2 positions (only at the ω-2 position in myristoleic acid). Alkyl esters of fatty acids and monoglycerides were also ω-1 or ω-2 hydroxylated, but di- and tri-glycerides were not modified. Fatty alcohols yielded hydroxy derivatives at the ω-1 or ω-2 positions (diols) but also fatty acids and their hydroxy derivatives. Interestingly, the peroxygenase was able to oxyfunctionalize alkanes giving, in addition to alcohols at positions 2 or 3, dihydroxylated derivatives at both sides of the molecule. The predominance of mono- or di-hydroxylated derivatives seems related to the higher or lower proportion of acetone, respectively, in the reaction medium. The recombinant C. cinerea peroxygenase appears as a promising biocatalyst for alkane activation and production of aliphatic oxygenated derivatives, with better properties than the previously reported peroxygenase from Agrocybe aegerita, and advantages related to its recombinant nature for enzyme engineering and industrial production.

  3. The in vitro antiviral activity of an aliphatic nitro compound from Heteropteris aphrodisiaca.

    PubMed

    Melo, Fernando L; Benati, Fabricio J; Roman, Walter Antonio; de Mello, João Carlos Palazzo; Nozawa, Carlos; Linhares, Rosa Elisa Carvalho

    2008-01-01

    We investigated the antiviral activity of an aliphatic nitro compound (NC) isolated from Heteropteris aphrodisiaca O. Mach. (Malpighiaceae), a Brazilian medicinal plant. The NC was tested for its antiviral activity against poliovirus type 1 (PV-1) and bovine herpes virus type 1 (BHV-1) by plaque reduction assay in cell culture. The NC showed a moderate antiviral activity against PV-1 and BHV-1 in HEp-2 cells, and the 50% inhibitory concentration (IC50) were 22.01 microg/ml (selectivity index (SI)=2.83) and 21.10 microg/ml (SI=2.95), respectively. At the highest concentration of the drug (40 microg/ml) a reduction of approximately 80% in plaque assay was observed for both viruses. The treatment of cells or virus prior to infection did not inhibit the replication of virus strains.

  4. Kinetics of oxidation of aliphatic and aromatic thiols by myeloperoxidase compounds I and II.

    PubMed

    Burner, U; Jantschko, W; Obinger, C

    1999-01-29

    Myeloperoxidase (MPO) is the most abundant protein in neutrophils and plays a central role in microbial killing and inflammatory tissue damage. Because most of the non-steroidal anti-inflammatory drugs and other drugs contain a thiol group, it is necessary to understand how these substrates are oxidized by MPO. We have performed transient kinetic measurements to study the oxidation of 14 aliphatic and aromatic mono- and dithiols by the MPO intermediates, Compound I (k3) and Compound II (k4), using sequential mixing stopped-flow techniques. The one-electron reduction of Compound I by aromatic thiols (e.g. methimidazole, 2-mercaptopurine and 6-mercaptopurine) varied by less than a factor of seven (between 1.39 +/- 0.12 x 10(5) M(-1) s(-1) and 9.16 +/- 1.63 x 10(5) M(-1) s(-1)), whereas reduction by aliphatic thiols was demonstrated to depend on their overall net charge and hydrophobic character and not on the percentage of thiol deprotonation or redox potential. Cysteamine, cysteine methyl ester, cysteine ethyl ester and alpha-lipoic acid showed k3 values comparable to aromatic thiols, whereas a free carboxy group (e.g. cysteine, N-acetylcysteine, glutathione) diminished k3 dramatically. The one-electron reduction of Compound II was far more constrained by the nature of the substrate. Reduction by methimidazole, 2-mercaptopurine and 6-mercaptopurine showed second-order rate constants (k4) of 1.33 +/- 0.08 x 10(5) M(-1) s(-1), 5.25 +/- 0.07 x 10(5) M(-1) s(-1) and 3.03 +/- 0.07 x 10(3) M(-1) s(-1). Even at high concentrations cysteine, penicillamine and glutathione could not reduce Compound II, whereas cysteamine (4.27 +/- 0.05 x 10(3) M(-1) s(-1)), cysteine methyl ester (8.14 +/- 0.08 x 10(3) M(-1) s(-1)), cysteine ethyl ester (3.76 +/- 0.17 x 10(3) M(-1) s(-1)) and alpha-lipoic acid (4.78 +/- 0.07 x 10(4) M(-1) s(-1)) were demonstrated to reduce Compound II and thus could be expected to be oxidized by MPO without co-substrates.

  5. Road tunnel, roadside, and urban background measurements of aliphatic compounds in size-segregated particulate matter

    NASA Astrophysics Data System (ADS)

    Alves, Célia A.; Oliveira, César; Martins, Natércia; Mirante, Fátima; Caseiro, Alexandre; Pio, Casimiro; Matos, Manuel; Silva, Hugo F.; Oliveira, Cristina; Camões, Filomena

    2016-02-01

    Particulate matter samples were collected in a road tunnel in Lisbon (PM0.5, PM0.5-1, PM1-2.5, and PM2.5-10) and at two urban locations representing roadside and background stations (PM2.5 and PM2.5-10). Samples were analysed for organic and elemental carbon (OC and EC), n-alkanes, n-alkenes, hopanes, some isoprenoid compounds, and steranes. Particulate matter concentrations in the tunnel were 17-31 times higher than at roadside in the vicinity, evidencing an aerosol origin almost exclusively in fresh vehicle emissions. PM0.5 in the tunnel comprised more than 60% and 80% of the total OC and EC mass in PM10, respectively. Concentrations of the different aliphatic groups of compounds in the tunnel were up to 89 times higher than at roadside and 143 times higher than at urban background. Based on the application of hopane-to-OC or hopanes-to-EC ratios obtained in the tunnel, it was found that vehicle emissions are the dominant contributor to carbonaceous particles in the city but do not represent the only source of these triterpenic compounds. Contrary to what has been observed in other studies, the Σhopane-to-EC ratios were higher in summer than in winter, suggesting that other factors (e.g. biomass burning, dust resuspension, and different fuels/engine technologies) prevail in relation to the photochemical decay of triterpenoid hydrocarbons from vehicle exhaust.

  6. Effect of low molecular weight aliphatic alcohols and related compounds on platelet factor 4 subunit association.

    PubMed

    Yang, Y; Barker, S; Chen, M J; Mayo, K H

    1993-05-05

    Titration of platelet factor 4 (PF4) with increasing concentrations of various low molecular weight aliphatic alcohols disrupts dimer and tetramer quaternary structure while preserving tertiary structural integrity. Normally observed slow subunit exchange (1H NMR time scale) is shifted into the fast chemical exchange regime. The order of effectiveness is butanol > 2-propanol > propanol > ethanol > methanol. Fluorination of ethanol (trifluoroethanol) and 2-propanol (hexafluoro-2-propanol) increases effectiveness by approximately 2 orders of magnitude. Oxidation to 2-propanone or trifluoro-2-propanone produces a less effective compound, suggesting a mechanistic role for the hydroxyl group. Increasing the number of hydroxyls to three, as in glycerol, however, is relatively ineffective in disrupting aggregate states or modifying subunit exchange rates. While 19F NMR studies indicate that these alcohols specifically interact with PF4, binding alone can not explain their mechanism of action. Dimethyl sulfoxide, structurally similar to 2-propanol, disrupts PF4 aggregation by direct binding, but does not shift subunit exchange kinetics into the NMR fast-exchange regime. Although not fully understood, the effectiveness of these compounds appears to be related to the colligative properties of the solution.

  7. Quantitative structure-activity relationships for toxicity and genotoxicity of halogenated aliphatic compounds: wing spot test of Drosophila melanogaster.

    PubMed

    Chroust, Karel; Pavlová, Martina; Prokop, Zbynek; Mendel, Jan; Bozková, Katerina; Kubát, Zdenek; Zajícková, Veronika; Damborský, Jiri

    2007-02-01

    Halogenated aliphatic compounds were evaluated for toxic and genotoxic effects in the somatic mutation and recombination test employing Drosophila melanogaster. The tested chemicals included chlorinated, brominated and iodinated; mono-, di- and tri-substituted; saturated and unsaturated alkanes: 1,2-dibromoethane, 1-bromo-2-chloroethane, 1-iodopropane, 2,3-dichloropropene, 3-bromo-1-propene, epibromohydrin, 2-iodobutane, 3-chloro-2-methylpropene, 1,2,3-trichloropropane, 1,2-dichloroethane, 1,2-dichlorobutane, 1-chloro-2-methylpropane, 1,3-dichloropropane, 1,2-dichloropropane, 2-chloroethymethylether, 1-bromo-2-methylpropane and 1-chloropentane. N-methyl-N-nitrosourea served as the positive and distilled water as the negative control. The set of chemicals for the toxicological testing was selected by the use of statistical experiment design. Group of unsaturated aliphatic hydrocarbons were generally more toxic than saturated analogues. The genotoxic effect was observed with 14 compounds in the wing spot test, while 3 substances did not show any genotoxicity by using the wing spot test at 50% lethal concentration. The highest number of wing spots was observed in genotoxicity assay with 1-bromo-2-chloroethane, 1,2-dichloroethane, 1,2-dibromoethane and 1-iodopropane. Nucleophilic superdelocalizability calculated by quantum mechanics appears to be a good parameter for prediction of both toxicity and genotoxicity effects of halogenated aliphatic compounds.

  8. Content of carotenoids, tocopherols, sterols, triterpenic and aliphatic alcohols, and volatile compounds in six walnuts (Juglans regia L.) varieties.

    PubMed

    Abdallah, Ikram Bou; Tlili, Nizar; Martinez-Force, Enrique; Rubio, Ana Gracia Pérez; Perez-Camino, Maria Carmen; Albouchi, Ali; Boukhchina, Sadok

    2015-04-15

    The aim of this work was to study the content of tocopherols, sterols, triterpenic and aliphatic alcohols, carotenoids, and volatile compounds in the kernel oils from six walnut (Juglans regia L.) varieties. The levels of β-carotene ranged between 0.22 and 0.62 mg/kg, followed by lutein (0.01-0.06 mg/kg). The total content of tocopherol ranged from 186.5 to 436.2 mg/kg of the extracted oil and the major isoform in all samples was γ-tocopherol. The most abundant phytosterol was β-sitosterol (974-1494 mg/kg) followed by campesterol then Δ-5-avenasterol. The major triterpenic alcohol was cycloartenol (226.4-532.1 mg/kg). Hexacosanol (9.71-28.15 mg/kg) was the major aliphatic alcohol. The detected volatile compounds were pentanal, hexanal, nonanal, 2-decenal and hexanol. The statistical analysis showed significant differences between varieties, which are probably due to genetic factors. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Neurophysiological studies on the relation between the structural properties and neurotoxicity of aliphatic hydrocarbon compounds in rats.

    PubMed Central

    Misumi, J; Nagano, M

    1984-01-01

    In order to determine the specific structural properties responsible for neurotoxic activity, the comparative neurotoxicity of n-hexane, methyl n-butyl ketone, 2,5-hexanedione, and their relatives was investigated in the peripheral nerves of rats. The maximum conduction velocity of motor and sensory fibres and the motor distal latency of the tail nerves of rats were periodically examined in animals receiving repeated subcutaneous injections of 11 aliphatic monoketone or diketone compounds and their relatives for prolonged periods. A study of the comparative neurotoxicity of n-hexane, methyl n-butyl ketone, and their metabolites showed that 2,5-hexanedione was the most actively neurotoxic. Furthermore, a study of other symmetrical diketones with different carbon numbers showed that 2,4-pentanedione, which is structurally similar to 2,5-hexanedione, possessed a different type of neurotoxic activity than 2,5-hexanedione. Regarding aliphatic monoketone compounds, acetone, 2-pentanone, 2-heptanone, and 2-octanone were confirmed non-neurotoxic for the peripheral nervous system. Evidence from some previous reports, however, suggested that 3-heptanone, 4-octanone, and 5-nonanone might produce neuropathies by being converted to 2,5-diketones under specific conditions. PMID:6093852

  10. Compound Specific Stable Chlorine Isotopic Analysis of Volatile Aliphatic Compounds Using Gas Chromatography Hyphenated with Multiple Collector Inductively Coupled Plasma Mass Spectrometry.

    PubMed

    Horst, Axel; Renpenning, Julian; Richnow, Hans-Hermann; Gehre, Matthias

    2017-09-05

    Stable chlorine isotope analysis is increasingly used to characterize sources, transformation pathways, and sinks of organic aliphatic compounds, many of them being priority pollutants in groundwater and the atmosphere. A wider use of chlorine isotopes in environmental studies is still inhibited by limitations of the different analytical techniques such as high sample needs, offline preparation, confinement to few compounds and mediocre precision, respectively. Here we present a method for the δ(37)Cl determination in volatile aliphatic compounds using gas chromatography coupled with multiple-collector inductively coupled plasma mass spectrometry (GC-MC-ICPMS), which overcomes these limitations. The method was evaluated by using a suite of five previously offline characterized in-house standards and eight chlorinated methanes, ethanes, and ethenes. Other than in previous approaches using ICP methods for chlorine isotopes, isobaric interference of the (36)ArH dimer with (37)Cl was minimized by employing dry plasma conditions. Samples containing 2-3 nmol Cl injected on-column were sufficient to achieve a precision (σ) of 0.1 mUr (1 milliurey = 0.001 = 1‰) or better. Long-term reproducibility and accuracy was always better than 0.3 mUr if organics were analyzed in compound mixtures. Standardization is carried out by using a two-point calibration approach. Drift, even though very small in this study, is corrected by referencing versus an internal standard. The presented method offers a direct, universal, and compound-specific procedure to measure the δ(37)Cl of a wide array of organic compounds overcoming limitations of previous techniques with the benefits of high sensitivity and accuracy comparable to the best existing approaches.

  11. Dechlorination of trichlorofluoromethane (CFC-11) by sulfate-reducing bacteria from an aquifer contaminated with halogenated aliphatic compounds

    SciTech Connect

    Sonier, D.N.; Duran, N.L.; Smith, G.B.

    1994-12-01

    Halogenated aliphatic hydrocarbons such as trichlorofluomethane (CFC-11) have been widely used as solvents, refrigerants, and aerosol and polystyrene propellants. This has relusted in contamination of the environment in the form of volatized gases, industrial waste water contamination or leakage from underground storage tanks. In situ bioremediation of CFC-11 resulting in complete mineralization or production of less harmful intermediates would be more environmentally appropriate. This study examines whether microorganisms present in anaerobic samples obtained from an aquifer contaminated with CFC-11 and TCE were capable of degrading these compounds. CFC-11 biodegradation, but not TCE. The researchers determined that the anaerobic process was dependent on the presence of acetate and sulfate, but independent of nitrate and bromethane sulfonic acid, indicating that sulfate-reducing bacteria are the responsible agents. 22 refs., 5 figs.

  12. Selective redox degradation of chlorinated aliphatic compounds by Fenton reaction in pyrite suspension.

    PubMed

    Che, Hyeongsu; Lee, Woojin

    2011-02-01

    Selective redox degradation of chlorinated aliphatics by Fenton reaction in pyrite suspension was investigated in a closed system. Carbon tetrachloride (CT) was used as a representative target of perchlorinated alkanes and trichloroethylene (TCE) was used as one of highly chlorinated alkenes. Degradation of CT in Fenton reaction was significantly enhanced by pyrite used as an iron source instead of soluble Fe. Pyrite Fenton showed 93% of CT removal in 140 min, while Fenton reaction with soluble Fe(II) showed 52% and that with Fe(III) 15%. Addition of 2-propanol to the pyrite Fenton system significantly inhibited degradation of TCE (99% to 44% of TCE removal), while degradation of CT was slightly improved by the 2-propanol addition (80-91% of CT removal). The result suggests that, unlike oxidative degradation of TCE by hydroxyl radical in pyrite Fenton system, an oxidation by the hydroxyl radical is not a main degradation mechanism for the degradation of CT in pyrite Fenton system but a reductive dechlorination by superoxide can rather be the one for the CT degradation. The degradation kinetics of CT in the pyrite Fenton system was decelerated (0.13-0.03 min(-1)), as initial suspension pH decreased from 3 to 2. The formation of superoxide during the CT degradation in the pyrite Fenton system was observed by electron spin resonance spectroscopy. The formation at initial pH 3 was greater than that at initial pH 2, which supported that superoxide was a main reductant for degradation of CT in the pyrite Fenton system.

  13. Source apportionment of atmospheric aliphatic and polycyclic aromatic hydrocarbons using compound-specific radiocarbon analysis

    NASA Astrophysics Data System (ADS)

    Gustafsson, Ö.; Mandalakis, M.; Zencak, Z.; Sheesley, R.; Kruså, M.

    2009-04-01

    Recent development in compound-specific radiocarbon analysis (CSRA) now allows application of this analytical dimension toward source apportionment of natural and anthropogenic compounds in the atmosphere. CSRA studies of semi-volatile n-alkanes and polycyclic aromatic hydrocarbons (PAHs) in air collected at various locations throughout Europe combine to reveal both inter-compound, inter-regional and inter-seasonal variations in sources. For instance, modern biogenic sources contribute a significant portion (frequently up to 50%) of the atmospheric load of priority pollutant PAHs and long-chained n-alkanes, suggesting that such sources should be scrutinized for effective reduction.

  14. Estimating the octanol/water partition coefficient for aliphatic organic compounds using semi-empirical electrotopological index.

    PubMed

    Souza, Erica Silva; Zaramello, Laize; Kuhnen, Carlos Alberto; Junkes, Berenice da Silva; Yunes, Rosendo Augusto; Heinzen, Vilma Edite Fonseca

    2011-01-01

    A new possibility for estimating the octanol/water coefficient (log P) was investigated using only one descriptor, the semi-empirical electrotopological index (I(SET)). The predictability of four octanol/water partition coefficient (log P) calculation models was compared using a set of 131 aliphatic organic compounds from five different classes. Log P values were calculated employing atomic-contribution methods, as in the Ghose/Crippen approach and its later refinement, AlogP; using fragmental methods through the ClogP method; and employing an approach considering the whole molecule using topological indices with the MlogP method. The efficiency and the applicability of the I(SET) in terms of calculating log P were demonstrated through good statistical quality (r > 0.99; s < 0.18), high internal stability and good predictive ability for an external group of compounds in the same order as the widely used models based on the fragmental method, ClogP, and the atomic contribution method, AlogP, which are among the most used methods of predicting log P.

  15. Aliphatic C(17)-polyacetylenes of the falcarinol type as potential health promoting compounds in food plants of the Apiaceae family.

    PubMed

    Christensen, Lars P

    2011-01-01

    Many epidemiological studies have provided evidence that a high intake of fruits and vegetables is associated with a reduced risk for the development of cancer and cardiovascular diseases. Fruits and vegetables are known to contain health promoting components such as vitamins, minerals, antioxidants and dietary fibers, however, it is unclear which of these are responsible for the health promoting properties of fruits and vegetables. Aliphatic C(17)-polyacetylenes of the falcarinol type, which occur in common food plants of the Apiaceae family such as carrot, celeriac, parsnip and parsley, have demonstrated interesting bioactivities including antibacterial, antimycobacterial, and antifungal activity as well as anti-inflammatory, anti-platelet-aggregatory, neuritogenic and serotonergic effects. In addition, the cytotoxicity of falcarinol type polyacetylenes towards human cancer cells, bioavailability, and their potential anticancer effect in vivo indicates that these compounds may contribute to the health effects of certain vegetables and hence could be important nutraceuticals. The bioactivity of falcarinol type polyacetylenes occurring in food plants of the Apiaceae family, their possible mode of action and possible health promoting effects are discussed in this review as well as the effect of storage, processing and other factors that can influence the content of these compounds in particular root vegetables and products. Moreover, recent patents on bioactivity of falcarinol type polyacetylenes and inventions making use of this knowledge are presented and discussed.

  16. Effects of halogenated aromatics/aliphatics and nitrogen(N)-heterocyclic aromatics on estimating the persistence of future pharmaceutical compounds using a modified QSAR model.

    PubMed

    Lim, Seung Joo; Fox, Peter

    2014-02-01

    The effects of halogenated aromatics/aliphatics and nitrogen(N)-heterocyclic aromatics on estimating the persistence of future pharmaceutical compounds were investigated using a modified half life equation. The potential future pharmaceutical compounds investigated were approximately 2000 pharmaceutical drugs currently undergoing the United States Food and Drug Administration (US FDA) testing. EPI Suite (BIOWIN) model estimates the fates of compounds based on the biodegradability under aerobic conditions. While BIOWIN considered the biodegradability of a compound only, the half life equation used in this study was modified by biodegradability, sorption and cometabolic oxidation. It was possible that the potential future pharmaceutical compounds were more accurately estimated using the modified half life equation. The modified half life equation considered sorption and cometabolic oxidation of halogenated aromatic/aliphatics and nitrogen(N)-heterocyclic aromatics in the sub-surface, while EPI Suite (BIOWIN) did not. Halogenated aliphatics in chemicals were more persistent than halogenated aromatics in the sub-surface. In addition, in the sub-surface environment, the fates of organic chemicals were much more affected by halogenation in chemicals than by nitrogen(N)-heterocyclic aromatics.

  17. Dechlorination of trichlorofluoromethane (CFC-11) by sulfate-reducing bacteria from an aquifer contaminated with halogenated aliphatic compounds.

    PubMed Central

    Sonier, D N; Duran, N L; Smith, G B

    1994-01-01

    Groundwater samples were obtained from a deep aquifer contaminated with halogenated aliphatic compounds. One-milliliter samples contained 9.2 x 10(5) total bacteria (by acridine orange microscopic counts) and 2.5 x 10(3) sulfate-reducing bacteria (by most probable number analysis). Samples were incubated anaerobically in a basal salts medium with acetate as the electron donor and nitrate and sulfate as the electron acceptors. Residual levels of trichlorofluoromethane (CFC-11) in samples were biotically degraded, while trichloroethylene was not. When successively higher levels of CFC-11 were added, increasingly rapid degradation rates were observed. Concomitant with CFC-11 degradation was the near stoichiometric production of fluorodichloromethane (HCFC-21); the production of HCFC-21 was verified by mass spectrometry. CFC-11 degradation was dependent on the presence of acetate (or butyrate) and sulfate but was independent of nitrate. Other carbon sources such as lactate and isopropanol did not support the degradation. The addition of 1 mM sodium sulfide completely inhibited CFC-11 degradation; however, degradation occurred in the presence of 2 mM 2-bromoethanesulfonic acid. These results indicate that the anaerobic dechlorination of CFC-11 is carried out by sulfate-reducing bacteria and not by denitrifying or methanogenic bacteria. Images PMID:7811093

  18. Limiting activity coefficients of some aromatic and aliphatic nitro compounds in water

    SciTech Connect

    Benes, M.; Dohnal, V.

    1999-09-01

    Limiting activity coefficients of nine nitroaromatic compounds and four nitroalkanes in water were determined in the range of environmentally related temperatures by measuring suitable phase equilibria. For liquid and solid nitroaromatics (nitrobenzene, 2-nitrotoluene, 3-nitrotoluene, 4-nitrotoluene, 2-nitrophenol, 3-nitrophenol, 4-nitrophenol, 1-chloro-2-nitrobenzene, and 1-chloro-4-nitrobenzene) the aqueous solubilities were measured by a conventional batch contacting method with UV spectrophotometric analysis, while for nitroalkanes (nitromethane, nitroethane, 1-nitropropane, and 2-nitropropane) the air-water partitioning (Henry`s law constant H{sub 12} or air-water partition coefficient K{sub aw}) was determined by the inert gas stripping method employing gas chromatography. Whenever possible, results were compared to literature values. Calculation of H{sub 12} or K{sub aw} for nitroaromatics from the measured solubilities is hindered by the lack of reliable vapor pressure data. On the basis of the temperature dependences of the solubilities measured, the enthalpies of solution at infinite dilution for the nitroaromatics in water were evaluated.

  19. Assessing the Origins of Aliphatic Amines in the Murchison Meteorite from their Compound-Specific Carbon Isotopic Ratios and Enantiomeric Composition

    NASA Technical Reports Server (NTRS)

    Aponte, Jose; Dworkin, Jason; Elsila, Jamie E.

    2014-01-01

    The study of meteoritic organic compounds provides a unique window into the chemical inventory of the early Solar System and prebiotic chemistry that may have been important for the origin of life on Earth. Multiple families of organic compounds have been extracted from the Murchison meteorite, which is one of the most thoroughly studied carbonaceous chondrites. The amino acids extracted from Murchison have been extensively analyzed, including measurements of non-terrestrial stable isotopic ratios and discoveries of L-enantiomeric excesses for alpha-dialkyl amino acids, notably isovaline. However, although the isotopic signatures of bulk amine-containing fractions have been measured, the isotopic ratios and enantiomeric composition of individual aliphatic amines, compounds that are chemically related to amino acids, remain unknown. Here, we report a novel method for the extraction, separation, identification and quantitation of aliphatic monoamines extracted from the Murchison meteorite. Our results show a complete suite of structural isomers, with a larger concentration of methylamine and ethylamine and decreasing amine concentrations with increasing carbon number. The carbon isotopic compositions of fourteen meteoritic aliphatic monoamines were measured, with delta C-13 values ranging from +21% to +129%, showing a decrease in C-13 with increasing carbon number, a relationship that may be consistent with the chain elongation mechanism under kinetic control previously proposed for meteoritic amino acids. We also found the enantiomeric composition of sec-butylamine, a structural analog to isovaline, was racemic within error, while the isovaline extracted from the same Murchison piece showed an L-enantiomeric excess of 9.7; this result suggested that processes leading to enantiomeric excess in the amino acid did not affect the amine. We used these collective data to assess the primordial synthetic origins of these meteoritic aliphatic amines and their potential

  20. Reactions of organoaluminum compounds with acetylene as a method for the synthesis of aliphatic derivatives with a z-disubstituted double bond

    SciTech Connect

    Andreeva, N.I.; Kuchin, A.V.; Tolstikov, G.A.

    1985-11-01

    This paper develops a method for the synthesis of aliphatic compounds with a Z-disubstituted double bond, which are important synthons for the preparation of such natural products as insect pheromones, aromatic principles, etc. In the carbalumination reaction of acetylene Z-alkenyldialkylaluminums are formed selectively. A-Alkenyldialkylaluminums are highly reactive and can readily be converted into Z-allyl alcohols and their ethers, and into Z-iodovinyl derivatives. By the reactions of vinyl organoaluminum compounds with the complex CH/sub 3/COClhaAlCl/sub 3/ E-conjugated ketones were obtained.

  1. Palladium-catalyzed addition of potassium aryltrifluoroborates to aliphatic nitriles: synthesis of alkyl aryl ketones, diketone compounds, and 2-arylbenzo[b]furans.

    PubMed

    Wang, Xingyong; Liu, Miaochang; Xu, Long; Wang, Qingzong; Chen, Jiuxi; Ding, Jinchang; Wu, Huayue

    2013-06-07

    A palladium-catalyzed addition of potassium aryltrifluoroborates to aliphatic nitriles has been developed, leading to a wide range of alkyl aryl ketones with moderate to excellent yields. Moreover, several dinitriles (e.g., malononitrile, glutaronitrile, and adiponitrile) were applicable to this process for the construction of 1,3-, 1,5-, or 1,6-dicarbonyl compounds. The scope of the developed approach is successfully explored toward the one-step synthesis of 2-arylbenzo[b]furans via sequential addition and intramolecular annulation reactions. The methodology accepted a wide range of substrates and is applicable to library synthesis.

  2. Estimating the physicochemical properties of polyhalogenated aromatic and aliphatic compounds using UPPER: part 1. Boiling point and melting point.

    PubMed

    Admire, Brittany; Lian, Bo; Yalkowsky, Samuel H

    2015-01-01

    The UPPER (Unified Physicochemical Property Estimation Relationships) model uses enthalpic and entropic parameters to estimate 20 biologically relevant properties of organic compounds. The model has been validated by Lian and Yalkowsky on a data set of 700 hydrocarbons. The aim of this work is to expand the UPPER model to estimate the boiling and melting points of polyhalogenated compounds. In this work, 19 new group descriptors are defined and used to predict the transition temperatures of an additional 1288 compounds. The boiling points of 808 and the melting points of 742 polyhalogenated compounds are predicted with average absolute errors of 13.56 K and 25.85 K, respectively. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Synthesis, crystal structures and magnetic properties of dinuclear copper(II) compounds with NNO tridentate Schiff base ligands and bridging aliphatic diamine and aromatic diimine linkers.

    PubMed

    Rigamonti, Luca; Forni, Alessandra; Pievo, Roberta; Reedijk, Jan; Pasini, Alessandro

    2011-04-07

    The synthesis and the characterization of new dinuclear copper(II) compounds of general formula [(L(a-d))(2)Cu(2)(μ-N-N)](ClO(4))(2) (1-6) with either neutral aliphatic diamine (N-N = piperazine, pip) or aromatic diimine (N-N = 4,4'-bipyridine, 4,4'-bipy) linker are reported. The copper ligands L(-) (L(a-) = (E)-2-((2-aminoethylimino)methyl)phenolate, L(b-) = (E)-2-((2-aminopropylimino)methyl)-phenolate, L(c-) = (E)-2-((2-aminoethylimino)methyl)4-nitrophenolate, L(d-) = (E)-2-((2-aminoethylimino)methyl)4-methoxyphenolate) are NNO tridentate Schiff bases derived from the monocondensation of a substituted salicylaldehyde 5-G-salH (G = NO(2), H, OMe) with ethylenediamine, en, or 1,3-propylenediamine, tn. The crystal structures of compounds [(L(a))(2)Cu(2)(MeOH)(2)(μ-4,4'-bipy)](ClO(4))(2) (1·2MeOH), [(L(b))(2)Cu(2)(MeOH)(2)(μ-4,4'-bipy)](ClO(4))(2) (2·2MeOH), [(L(d))(2)Cu(2)(μ-4,4'-bipy)](ClO(4))(2) (4), [(L(a))(2)Cu(2)(μ-pip)](ClO(4))(2) (5) and [(L(b))(2)Cu(2)(μ-pip)](ClO(4))(2) (6) have been determined, revealing the preferred (e-e)-chair conformation of the bridging piperazine in compounds 5 and 6. The presence of hydrogen-bond-mediated intermolecular interactions, that involve the methanol molecules, yields dimers of dinuclear units for 1·2MeOH, and infinite zig-zag chains for 2·2MeOH. The temperature dependences of the magnetic susceptibilities χ(M)(T) for all compounds were measured, indicating the presence of antiferromagnetic Cu-Cu exchange. For the compounds 2-4 with 4,4'-bipy, the coupling constants J are around -1 cm(-1), while in compound 1 no interaction could be detected. The compounds 5 and 6 with piperazine display higher Cu-Cu magnetic interactions through the σ-bonding backbone of the bridging molecule, with J around -8 cm(-1), and the coupling is favoured by the (e-e)-chair conformation of the diamine ring. The non-aromatic, but shorter, linker piperazine gives rise to stronger Cu-Cu antiferromagnetic couplings than the aromatic, but

  4. Aliphatic hydrocarbons of the fungi.

    NASA Technical Reports Server (NTRS)

    Weete, J. D.

    1972-01-01

    Review of studies of aliphatic hydrocarbons which have been recently detected in the spores of phytopathogenic fungi, and are found to be structurally very similar to the alkanes of higher plants. It appears that the hydrocarbon components of the few mycelial and yeast forms reported resemble the distribution found in bacteria. The occurence and distribution of these compounds in the fungi is discussed. Suggested functional roles of fungal spore alkanes are presented.

  5. Aliphatic hydrocarbons of the fungi.

    NASA Technical Reports Server (NTRS)

    Weete, J. D.

    1972-01-01

    Review of studies of aliphatic hydrocarbons which have been recently detected in the spores of phytopathogenic fungi, and are found to be structurally very similar to the alkanes of higher plants. It appears that the hydrocarbon components of the few mycelial and yeast forms reported resemble the distribution found in bacteria. The occurence and distribution of these compounds in the fungi is discussed. Suggested functional roles of fungal spore alkanes are presented.

  6. The adjuvant activity of aliphatic nitrogenous bases

    PubMed Central

    Gall, D.

    1966-01-01

    By the use of diphtheria toxoid in guinea-pigs, high adjuvant activity has been found in a number of aliphatic nitrogenous bases including amines, quaternary ammonium compounds, guanidines, benzamidines and thiouroniums. Activity appears to depend on a combination of basicity and a long aliphatic chain of twelve or more carbon atoms. Such adjuvants tend to be haemolytic, and cause damage to tissue culture monolayers. It is suggested that their activity is connected with their surface activity and hence their ability to alter cell membranes, but that the basicity plays a further as yet undetermined role. ImagesFIG. 1-2FIG. 3-4 PMID:5924622

  7. Aliphatic amines in the Murchison meteorite

    NASA Technical Reports Server (NTRS)

    Jungclaus, G.; Cronin, J. R.; Moore, C. B.; Yuen, G. U.

    1976-01-01

    The paper reports on the determination of aliphatic amines in water extracts of the Murchison meteorite. The amines were analyzed by gas chromatography both as the free amines and as 2,4-dinitrophenyl (DNP) derivatives. The results give evidence for the presence of all of the possible primary aliphatic monoamines (eight) with fewer than five carbon atoms. Two of the seven possible secondary or tertiary aliphatic monoamines were identified. The identified primary amines total 80 nmol per g meteorite, and seem to be chemically or physically trapped in the meteorite. Similarities between the water-extractable amines and amino acids suggest that (1) a simple carbon compound, methane, for example, is the precursor of meteorite amines and amino acids, and (2) both amines and amino acids are extracted from the meteorite both as such and in the form of acid-hydrolyzable derivative or precursor species.

  8. Generation of standard gas mixtures of halogenated, aliphatic, and aromatic compounds and prediction of the individual output rates based on molecular formula and boiling point.

    PubMed

    Thorenz, Ute R; Kundel, Michael; Müller, Lars; Hoffmann, Thorsten

    2012-11-01

    In this work, we describe a simple diffusion capillary device for the generation of various organic test gases. Using a set of basic equations the output rate of the test gas devices can easily be predicted only based on the molecular formula and the boiling point of the compounds of interest. Since these parameters are easily accessible for a large number of potential analytes, even for those compounds which are typically not listed in physico-chemical handbooks or internet databases, the adjustment of the test gas source to the concentration range required for the individual analytical application is straightforward. The agreement of the predicted and measured values is shown to be valid for different groups of chemicals, such as halocarbons, alkanes, alkenes, and aromatic compounds and for different dimensions of the diffusion capillaries. The limits of the predictability of the output rates are explored and observed to result in an underprediction of the output rates when very thin capillaries are used. It is demonstrated that pressure variations are responsible for the observed deviation of the output rates. To overcome the influence of pressure variations and at the same time to establish a suitable test gas source for highly volatile compounds, also the usability of permeation sources is explored, for example for the generation of molecular bromine test gases.

  9. CCN activity of aliphatic amine secondary aerosol

    NASA Astrophysics Data System (ADS)

    Tang, X.; Price, D.; Praske, E.; Vu, D.; Purvis-Roberts, K.; Silva, P. J.; Cocker, D. R., III; Asa-Awuku, A.

    2014-01-01

    Aliphatic amines can form secondary aerosol via oxidation with atmospheric radicals (e.g. hydroxyl radical and nitrate radical). The particle composition can contain both secondary organic aerosol (SOA) and inorganic salts. The fraction of organic to inorganic materials in the particulate phase influences aerosol hygroscopicity and cloud condensation nuclei (CCN) activity. SOA formed from trimethylamine (TMA) and butylamine (BA) reactions with hydroxyl radical (OH) is composed of organic material of low hygroscopicity (single hygroscopicity parameter, κ ≤ 0.25). Secondary aerosol formed from the tertiary aliphatic amine (TMA) with N2O5 (source of nitrate radical, NO3), contains less volatile compounds than the primary aliphatic amine (BA) aerosol. TMA + N2O5 form semi-volatile organics in low RH conditions that have κ ~ 0.20, indicative of slightly soluble organic material. As RH increases, several inorganic amine salts are formed as a result of acid-base reactions. The CCN activity of the humid TMA-N2O5 aerosol obeys Zdanovskii, Stokes, and Robinson (ZSR) ideal mixing rules. Higher CCN activity (κ > 0.3) was also observed for humid BA+N2O5 aerosols compared with dry aerosol (κ ~ 0.2), as a result of the formation of inorganic salts such as NH4NO3 and butylamine nitrate (C4H11N · HNO3). Compared with TMA, BA+N2O5 reactions produce more volatile aerosols. The BA+N2O5 aerosol products under humid experiments were found to be very sensitive to the temperature within the stream-wise continuous flow thermal gradient CCN counter. The CCN counter, when set above a 21 °C temperature difference, evaporates BA+N2O5 aerosol formed at RH ≥ 30%; κ ranges from 0.4 to 0.7 and is dependent on the instrument supersaturation (ss) settings. The aerosol behaves non-ideally, hence simple ZSR rules cannot be applied to the CCN results from the primary aliphatic amine system. Overall, aliphatic amine aerosol systems κ ranges from 0.2 < κ < 0.7. This work indicates that

  10. Adsorption of halogenated aliphatic contaminants by graphene nanomaterials.

    PubMed

    Zhou, Yang; Apul, Onur Guven; Karanfil, Tanju

    2015-08-01

    In this study, adsorption of ten environmentally halogenated aliphatic synthetic organic compounds (SOCs) by a pristine graphene nanosheet (GNS) and a reduced graphene oxide (rGO) was examined, and their adsorption behaviors were compared with those of a single-walled carbon nanotube (SWCNT) and a granular activated carbon (GAC). In addition, the impacts of background water components (i.e., natural organic matter (NOM), ionic strength (IS) and pH) on the SOC adsorption behavior were investigated. The results indicated HD3000 and SWCNT with higher microporous volumes exhibited higher adsorption capacities for the selected aliphatic SOCs than graphenes, demonstrating microporosity of carbonaceous adsorbents played an important role in the adsorption. Analysis of adsorption isotherms demonstrated that hydrophobic interactions were the dominant contributor to the adsorption of aliphatic SOCs by graphenes. However, π-π electron donor-acceptor and van der Waals interactions are likely the additional mechanisms contributing to the adsorption of aliphatic SOCs on graphenes. Among the three background solution components examined, NOM showed the most influential effect on adsorption of the selected aliphatic SOCs, while pH and ionic strength had a negligible effects. The NOM competition on aliphatic adsorption was less pronounced on graphenes than SWCNT. Overall, in terms of adsorption capacities, graphenes tested in this study did not exhibit a major advantage over SWCNT and GAC for the adsorption of aliphatic SOCs.

  11. Estimating the physicochemical properties of polyhalogenated aromatic and aliphatic compounds using UPPER: part 2. Aqueous solubility, octanol solubility and octanol-water partition coefficient.

    PubMed

    Admire, Brittany; Lian, Bo; Yalkowsky, Samuel H

    2015-01-01

    The UPPER (Unified Physicochemical Property Estimation Relationships) model uses additive and non-additive parameters to estimate 20 biologically relevant properties of organic compounds. The model has been validated by Lian and Yalkowsky (2014) on a data set of 700 hydrocarbons. Recently, Admire et al. (2014) expanded the model to predict the boiling and melting points of 1288 polyhalogenated benzenes, biphenyls, dibenzo-p-dioxins, diphenyl ethers, anisoles and alkanes. In this work, 19 new group descriptors are determined and used to predict the aqueous solubilities, octanol solubilities and the octanol-water coefficients.

  12. Characterizing aliphatic moieties in hydrocarbons with atomic force microscopy† †Electronic supplementary information (ESI) available: Additional scanning tunneling microscopy (STM) and atomic force microscopy (AFM) measurements as well as NMR, optical spectroscopy and gas chromatography (GC) characterization of the five model compounds are provided. For CPNP and CHNP the synthetic route is described. See DOI: 10.1039/c6sc04698c Click here for additional data file.

    PubMed Central

    Collazos, Sara; Fatayer, Shadi; Meyer, Gerhard; Pérez, Dolores; Guitián, Enrique; Harper, Michael R.; Kushnerick, J. Douglas; Gross, Leo

    2017-01-01

    We designed and studied hydrocarbon model compounds by high-resolution noncontact atomic force microscopy. In addition to planar polycyclic aromatic moieties, these novel model compounds feature linear alkyl and cycloaliphatic motifs that exist in most hydrocarbon resources – particularly in petroleum asphaltenes and other petroleum fractions – or in lipids in biological samples. We demonstrate successful intact deposition by sublimation of the alkyl-aromatics, and differentiate aliphatic moieties from their aromatic counterparts which were generated from the former by atomic manipulation. The characterization by AFM in combination with atomic manipulation provides clear fingerprints of the aromatic and aliphatic moieties that will facilitate their assignment in a priori unknown samples. PMID:28451335

  13. Low-dimensional hydrogen-bonded structures in the 1:1 and 1:2 proton-transfer compounds of 4,5-dichlorophthalic acid with the aliphatic Lewis bases triethylamine, diethylamine, n-butylamine and piperidine.

    PubMed

    Smith, Graham; Wermuth, Urs D

    2010-07-01

    The structures of the proton-transfer compounds of 4,5-dichlorophthalic acid (DCPA) with the aliphatic Lewis bases triethylamine, diethylamine, n-butylamine and piperidine, namely triethylaminium 2-carboxy-4,5-dichlorobenzoate, C(6)H(16)N(+) x C(8)H(3)Cl(2)O(4)(-), (I), diethylaminium 2-carboxy-4,5-dichlorobenzoate, C(4)H(12)N(+) x C(8)H(3)Cl(2)O(4)(-), (II), bis(butanaminium) 4,5-dichlorobenzene-1,2-dicarboxylate monohydrate, 2C(4)H(12)N(+) x C(8)H(2)Cl(2)O(4)(2-) x H(2)O, (III), and bis(piperidinium) 4,5-dichlorobenzene-1,2-dicarboxylate monohydrate, 2C(5)H(12)N(+) x C(8)H(2)Cl(2)O(4)(2-) x H(2)O, (IV), have been determined at 200 K. All compounds have hydrogen-bonding associations, giving discrete cation-anion units in (I) and linear chains in (II), while (III) and (IV) both have two-dimensional structures. In (I), a discrete cation-anion unit is formed through an asymmetric R(1)(2)(4) N(+)-H...O(2) hydrogen-bonding association, whereas in (II), chains are formed through linear N-H...O associations involving both aminium H-atom donors. In compounds (III) and (IV), the primary N-H...O-linked cation-anion units are extended into a two-dimensional sheet structure via amide-carboxyl N-H...O and amide-carbonyl N-H...O interactions. In the 1:1 salts (I) and (II), the hydrogen 4,5-dichlorophthalate anions are essentially planar with short intramolecular carboxyl-carboxyl O-H...O hydrogen bonds [O...O = 2.4223 (14) and 2.388 (2) A, respectively]. This work provides a further example of the uncommon zero-dimensional hydrogen-bonded DCPA-Lewis base salt and the one-dimensional chain structure type, while even with the hydrate structures of the 1:2 salts with the primary and secondary amines, the low dimensionality generally associated with 1:1 DCPA salts is also found.

  14. Certain Aliphatic Nitramines and Related Compounds

    DTIC Science & Technology

    1944-11-29

    dinitraminoproptMie. Because of the relation that these nitraininos bear to the corresponding nitrates correlations of the relative effect en explosive...our ethane, was saturated with dry gaseous ammonia and a gummy solid separated. The ether was removed from the gummy precipitate by decantation...5° after the addition was complete. The clear solution was poured on 500 g. ot crushed ice and a colorless gummy precipitate separated. The acid

  15. Cloud condensation nuclei (CCN) activity of aliphatic amine secondary aerosol

    NASA Astrophysics Data System (ADS)

    Tang, X.; Price, D.; Praske, E.; Vu, D. N.; Purvis-Roberts, K.; Silva, P. J.; Cocker, D. R., III; Asa-Awuku, A.

    2014-06-01

    Aliphatic amines can form secondary aerosol via oxidation with atmospheric radicals (e.g., hydroxyl radical and nitrate radical). The particle can contain both secondary organic aerosol (SOA) and inorganic salts. The ratio of organic to inorganic materials in the particulate phase influences aerosol hygroscopicity and cloud condensation nuclei (CCN) activity. SOA formed from trimethylamine (TMA) and butylamine (BA) reactions with hydroxyl radical (OH) is composed of organic material of low hygroscopicity (single hygroscopicity parameter, κ, ≤ 0.25). Secondary aerosol formed from the tertiary aliphatic amine (TMA) with N2O5 (source of nitrate radical, NO3) contains less volatile compounds than the primary aliphatic amine (BA) aerosol. As relative humidity (RH) increases, inorganic amine salts are formed as a result of acid-base reactions. The CCN activity of the humid TMA-N2O5 aerosol obeys Zdanovskii, Stokes, and Robinson (ZSR) ideal mixing rules. The humid BA + N2O5 aerosol products were found to be very sensitive to the temperature at which the measurements were made within the streamwise continuous-flow thermal gradient CCN counter; κ ranges from 0.4 to 0.7 dependent on the instrument supersaturation (ss) settings. The variance of the measured aerosol κ values indicates that simple ZSR rules cannot be applied to the CCN results from the primary aliphatic amine system. Overall, aliphatic amine aerosol systems' κ ranges within 0.2 < κ < 0.7. This work indicates that aerosols formed via nighttime reactions with amines are likely to produce hygroscopic and volatile aerosol, whereas photochemical reactions with OH produce secondary organic aerosol of lower CCN activity. The contributions of semivolatile secondary organic and inorganic material from aliphatic amines must be considered for accurate hygroscopicity and CCN predictions from aliphatic amine systems.

  16. Project Summary. IN-SITU AQUIFER RESTORATION OF CHLORINATED ALIPHATICS BY METHANOTROPHIC BACTERIA

    EPA Science Inventory

    This project evaluated the potential of an innovative approach to aquifer restoration: enhanced in-situ biotransformation of chlorinated aliphatic solvents by a bacterial community grown on methane under aerobic conditions. The target chlorinated compounds were trichloroethene (...

  17. Project Summary. IN-SITU AQUIFER RESTORATION OF CHLORINATED ALIPHATICS BY METHANOTROPHIC BACTERIA

    EPA Science Inventory

    This project evaluated the potential of an innovative approach to aquifer restoration: enhanced in-situ biotransformation of chlorinated aliphatic solvents by a bacterial community grown on methane under aerobic conditions. The target chlorinated compounds were trichloroethene (...

  18. OLFACTORY RESPONSES OF BLOWFLIES TO ALIPHATIC ALDEHYDES

    PubMed Central

    Dethier, V. G.

    1954-01-01

    The response of the blowfly Phormia regina to stimulation by aldehydes in the vapor phase has been studied by means of a specially designed olfactometer. The median rejection threshold and the maximum acceptance threshold were selected as criteria of response. For both acceptance and rejection the distribution of thresholds in the population is normal with respect to the logarithm of concentration. When thresholds are expressed as molar concentrations, the values decrease progressively as chain length is increased. There is no attraction beyond decanal and no rejection beyond dodecanal. When thresholds are expressed as activities, most members of the aldehyde series are approximately equally stimulating at rejection and equally stimulating at acceptance. The relationship is most exact over the middle range of chain lengths. There is a tendency for the terminal members to stimulate at higher activities. These relationships are in close agreement with those which were found earlier to apply to the normal aliphatic alcohols. The similarity between the relative actions of the members of the two series suggests that the relation of equal olfactory stimulation at equal thermodynamic activities by homologous aliphatic compounds at least for homologues of intermediate chain length may be of rather general application in olfaction. PMID:13174780

  19. Guided desaturation of unactivated aliphatics

    NASA Astrophysics Data System (ADS)

    Voica, Ana-Florina; Mendoza, Abraham; Gutekunst, Will R.; Fraga, Jorge Otero; Baran, Phil S.

    2012-08-01

    The excision of hydrogen from an aliphatic carbon chain to produce an isolated olefin (desaturation) without overoxidation is one of the most impressive and powerful biosynthetic transformations for which there are no simple and mild laboratory substitutes. The versatility of olefins and the range of reactions they undergo are unsurpassed in functional group space. Thus, the conversion of a relatively inert aliphatic system into its unsaturated counterpart could open new possibilities in retrosynthesis. In this article, the invention of a directing group to achieve such a transformation under mild, operationally simple, metal-free conditions is outlined. This ‘portable desaturase’ (TzoCl) is a bench-stable, commercial entity (Aldrich, catalogue number L510092) that is facile to install on alcohol and amine functionalities to ultimately effect remote desaturation, while leaving behind a synthetically useful tosyl group.

  20. Friction differences between aliphatic and aromatic structures in lubrication of titanium

    NASA Technical Reports Server (NTRS)

    Buckley, D. H.

    1975-01-01

    Sliding friction experiments were conducted with a titanium (0001) single crystal surface with various adsorbed aliphatic and aromatic compounds containing the same number of carbon atoms. An Auger emission spectroscopy analysis was used to monitor the presence of the organic lubricating compounds. Results of the investigation indicate that hexane and benzene give the same friction coefficients over a range of loads. At light loads the friction decreased with an increase in the halogen atom size where the halogens chlorine, bromine, and iodine are incorporated into the benzene molecular structure. The aliphatic compounds chlorohexane and bromohexane exhibited lower friction coefficients than the aromatic structures chlorobenzene and bromobenzene.

  1. A Comprehensive Review of Aliphatic Hydrocarbon Biodegradation by Bacteria.

    PubMed

    Abbasian, Firouz; Lockington, Robin; Mallavarapu, Megharaj; Naidu, Ravi

    2015-06-01

    Hydrocarbons are relatively recalcitrant compounds and are classified as high-priority pollutants. However, these compounds are slowly degraded by a large variety of microorganisms. Bacteria are able to degrade aliphatic saturated and unsaturated hydrocarbons via both aerobic and anaerobic pathways. Branched hydrocarbons and cyclic hydrocarbons are also degraded by bacteria. The aerobic bacteria use different types of oxygenases, including monooxygenase, cytochrome-dependent oxygenase and dioxygenase, to insert one or two atoms of oxygen into their targets. Anaerobic bacteria, on the other hand, employ a variety of simple organic and inorganic molecules, including sulphate, nitrate, carbonate and metals, for hydrocarbon oxidation.

  2. A case study on the myth of emission from aliphatic amides

    NASA Astrophysics Data System (ADS)

    Singh, Avinash Kumar; Das, Sreyashi; Datta, Anindya

    2016-12-01

    For several decades, aliphatic amidic compounds have been believed to be emissive. We report that this contention is incorrect and that the anomalous emission from amides originates in fluorescent impurities generated during their synthesis. In order to make this point, we have synthesized fluorescent compounds and have compared the absorption spectra with excitation spectra.

  3. Anaerobic digestion of aliphatic polyesters.

    PubMed

    Šmejkalová, Pavla; Kužníková, Veronika; Merna, Jan; Hermanová, Soňa

    2016-01-01

    Anaerobic processes for the treatment of plastic materials waste represent versatile and effective approach in environmental protection and solid waste management. In this work, anaerobic biodegradability of model aliphatic polyesters, poly(L-lactic acid) (PLA), and poly(ɛ-caprolactone) (PCL), in the form of powder and melt-pressed films with varying molar mass, was studied. Biogas production was explored in batch laboratory trials at 55 ± 1°C under a nitrogen atmosphere. The inoculum used was thermophilic digested sludge (total solids concentration of 2.9%) from operating digesters at the Central Waste Water Treatment Plant in Prague, Czech Republic. Methanogenic biodegradation of PCLs typically yielded from 54 to 60% of the theoretical biogas yield. The biodegradability of PLAs achieved from 56 to 84% of the theoretical value. High biogas yield (up to 677 mL/g TS) with high methane content (more than 60%), comparable with conventionally processed materials, confirmed the potential of polyester samples for anaerobic treatment in the case of their exploitation in agriculture or as a packaging material in the food industry.

  4. Safety in the Chemical Laboratory: Nitric Acid, Nitrates, and Nitro Compounds.

    ERIC Educational Resources Information Center

    Bretherick, Leslie

    1989-01-01

    Discussed are the potential hazards associated with nitric acid, inorganic and organic nitrate salts, alkyl nitrates, acyl nitrates, aliphatic nitro compounds, aromatic nitro compounds, and nitration reactions. (CW)

  5. Safety in the Chemical Laboratory: Nitric Acid, Nitrates, and Nitro Compounds.

    ERIC Educational Resources Information Center

    Bretherick, Leslie

    1989-01-01

    Discussed are the potential hazards associated with nitric acid, inorganic and organic nitrate salts, alkyl nitrates, acyl nitrates, aliphatic nitro compounds, aromatic nitro compounds, and nitration reactions. (CW)

  6. Contact allergy to reactive diluents and related aliphatic epoxy resins.

    PubMed

    Aalto-Korte, Kristiina; Kuuliala, Outi; Henriks-Eckerman, Maj-Len; Suuronen, Katri

    2015-06-01

    Diglycidyl ether of bisphenol A resin (DGEBA-R) is the most common sensitizer in epoxy systems, but a minority of patients also develop contact allergy to reactive diluents. To analyse the frequency and clinical relevance of allergic reactions to different epoxy reactive diluents and related aliphatic epoxy resins. Test files (January 1991 to June 2014) were screened, and the clinical records of patients with allergic reactions were analysed for occupation, concomitant allergic reactions, and exposure. A total of 67 patients reacted to at least one of the compounds. The largest numbers of allergic reactions were to phenyl glycidyl ether (PGE; n = 41), 1,4-butanediol diglycidyl ether (BDDGE; n = 34), and p-tert-butylphenyl glycidyl ether (PTBPGE; n = 19). Ten of the patients did not have contact allergy to DGEBA-R. The reactions of 5 of these were related to the use of BDDGE-containing products. We found no significant exposure to PGE or PTBPGE in patients sensitized to them, but some of the patients had used cresyl glycidyl ether-containing products. Allergic reactions to reactive diluents and related aliphatic epoxy resins usually occurred together with reactions to DGEBA-R. BDDGE was the clinically most significant compound, and was the sole cause of occupational allergic contact dermatitis in 3 patients. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  7. Click Chemistry in Functional Aliphatic Polycarbonates.

    PubMed

    Dai, Yu; Zhang, Xiaojin; Xia, Fan

    2017-10-01

    Click chemistry, one of the most important methods in conjugation, plays an extremely significant role in the synthesis of functional aliphatic polycarbonates, which are a group of biodegradable polymers containing carbonate bonds in their main chains. To date, more than 75 articles have been reported on the topic of click chemistry in functional aliphatic polycarbonates. However, these efforts have not yet been highlighted. Six categories of click reactions (alkyne-azide reaction, thiol-ene reaction, Michael addition, epoxy-amine/thiol reaction, Diels-Alder reaction, and imine formation) that have been afforded for further post-polymerization modification of polycarbonates are reviewed. Through this review, a comprehensive understanding of functional aliphatic polycarbonates aims to afford insight on the design of polycarbonates for further post-polymerization modification via click chemistry and the expectation of the practical application. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Biodegradation of individual and multiple chlorinated aliphatic hydrocarbons by methane-oxidizing cultures.

    PubMed Central

    Chang, H L; Alvarez-Cohen, L

    1996-01-01

    The microbial degradation of chlorinated and nonchlorinated methanes, ethanes, and ethanes by a mixed methane-oxidizing culture grown under chemostat and batch conditions is evaluated and compared with that by two pure methanotrophic strains: CAC1 (isolated from the mixed culture) and Methylosinus trichosporium OB3b. With the exception of 1,1-dichloroethylene, the transformation capacity (Tc) for each chlorinated aliphatic hydrocarbon was generally found to be in inverse proportion to its chlorine content within each aliphatic group (i.e., methanes, ethanes, and ethenes), whereas similar trends were not observed for degradation rate constants. Tc trends were similar for all methane-oxidizing cultures tested. None of the cultures were able to degrade the fully chlorinated aliphatics such as perchloroethylene and carbon tetrachloride. Of the four cultures tested, the chemostat-grown mixed culture exhibited the highest Tc for trichloroethylene, cis-1,2-dichloroethylene, tetrachloroethane, 1,1,1-trichloroethane, and 1,2-dichloroethane, whereas the pure batch-grown OB3b culture exhibited the highest Tc for all other compounds tested. The product toxicity of chlorinated aliphatic hydrocarbons in a mixture containing multiple compounds was cumulative and predictable when using parameters measured from the degradation of individual compounds. The Tc for each chlorinated aliphatic hydrocarbon in a mixture (Tcmix) and the total Tc for the mixture (sigma Tcmix) are functions of the individual Tc, the initial substrate concentration (S0), and the first-order rate constant (k/Ks) of each compound in the mixture, indicating the importance of identifying the properties and compositions of all potentially degradable compounds in a contaminant mixture. PMID:8795228

  9. Microbial degradation of aliphatic and aliphatic-aromatic co-polyesters.

    PubMed

    Shah, Aamer Ali; Kato, Satoshi; Shintani, Noboru; Kamini, Numbi Ramudu; Nakajima-Kambe, Toshiaki

    2014-04-01

    Biodegradable plastics (BPs) have attracted much attention since more than a decade because they can easily be degraded by microorganisms in the environment. The development of aliphatic-aromatic co-polyesters has combined excellent mechanical properties with biodegradability and an ideal replacement for the conventional nondegradable thermoplastics. The microorganisms degrading these polyesters are widely distributed in various environments. Although various aliphatic, aromatic, and aliphatic-aromatic co-polyester-degrading microorganisms and their enzymes have been studied and characterized, there are still many groups of microorganisms and enzymes with varying properties awaiting various applications. In this review, we have reported some new microorganisms and their enzymes which could degrade various aliphatic, aromatic, as well as aliphatic-aromatic co-polyesters like poly(butylene succinate) (PBS), poly(butylene succinate)-co-(butylene adipate) (PBSA), poly(ε-caprolactone) (PCL), poly(ethylene succinate) (PES), poly(L-lactic acid) (PLA), poly(3-hydroxybutyrate) and poly(3-hydoxybutyrate-co-3-hydroxyvalterate) (PHB/PHBV), poly(ethylene terephthalate) (PET), poly(butylene terephthalate) (PBT), poly(butylene adipate-co-terephthalate (PBAT), poly(butylene succinate-co-terephthalate) (PBST), and poly(butylene succinate/terephthalate/isophthalate)-co-(lactate) (PBSTIL). The mechanism of degradation of aliphatic as well as aliphatic-aromatic co-polyesters has also been discussed. The degradation ability of microorganisms against various polyesters might be useful for the treatment and recycling of biodegradable wastes or bioremediation of the polyester-contaminated environments.

  10. Nickel-catalysed retro-hydroamidocarbonylation of aliphatic amides to olefins

    NASA Astrophysics Data System (ADS)

    Hu, Jiefeng; Wang, Minyan; Pu, Xinghui; Shi, Zhuangzhi

    2017-05-01

    Amide and olefins are important synthetic intermediates with complementary reactivity which play a key role in the construction of natural products, pharmaceuticals and manmade materials. Converting the normally highly stable aliphatic amides into olefins directly is a challenging task. Here we show that a Ni/NHC-catalytic system has been established for decarbonylative elimination of aliphatic amides to generate various olefins via C-N and C-C bond cleavage. This study not only overcomes the acyl C-N bond activation in aliphatic amides, but also encompasses distinct chemical advances on a new type of elimination reaction called retro-hydroamidocarbonylation. This transformation shows good functional group compatibility and can serve as a powerful synthetic tool for late-stage olefination of amide groups in complex compounds.

  11. Synthesis and Bioactivity of 5-Substituted-2-furoyl Diacylhydazide Derivatives with Aliphatic Chain

    PubMed Central

    Cui, Zining; Li, Xinghai; Tian, Fang; Yan, Xiaojing

    2014-01-01

    A series of 5-substituted-2-furoyl diacylhydazide derivatives with aliphatic chain were designed and synthesized. Their structures were characterized by IR, 1H NMR, elemental analysis, and X-ray single crystal diffraction. The anti-tumor bioassay revealed that some title compounds exhibited promising activity against the selected cancer cell lines, especially against the human promyelocytic leukemic cells (HL-60). Their fungicidal tests indicated that most of the title compounds showed significant anti-fungal activity. The preliminary structure-activity relationship showed that the aliphatic chain length and differences in the R2 group had obvious effects on the anti-tumor and anti-fungal activities. The bioassay results demonstrated that the title compounds hold great promise as novel lead compounds for further drug discovery. PMID:24853128

  12. Spectrofluorimetric evaluation of total aliphatic and aromatic amines in well waters and wastewaters

    SciTech Connect

    Djozan, D.; Faraj-Zadeh, M.A.

    1998-09-01

    Aliphatic and aromatic amines are important metabolic intermediates in decomposition processes and are distributed in wastewaters. Monitoring of these compounds in the water samples can indicate whether the environmental waters are contaminated with wastewaters. A simple and rapid spectrofluorimetric method is described for the determination of aliphatic and aromatic amines on the basis of ammonia and aniline, respectively. Aromatic amines in samples were reacted at pH 5.5 with fluram immobilized on an Octadecylsilane Solid Phase Extraction (ODS-SPE) cartridge. The produced pyrrolinones were adsorbed on SPE and separated from the aliphatic amines. Analysis of these compounds was carried out by elution of SPE with 1 ml Tetrahydrofuran (THF) and determination of fluorescence intensity at excitation wavelength 400 nm and emission wavelength 475 nm. Aliphatic amines after passing from SPE were collected and reacted with fluram at pH 9.2, and extracted into dichloromethane at pH 3 and quantitated fluorimetrically. Linear dynamic ranges and detection limits (LOD) were 1-20, 0.43 mg l{sup {minus}1} and 1-200, 0.39 {micro}g l{sup {minus}1} for ammonia and aniline, respectively. The proposed method was successfully applied for the evaluation of these compounds in local well waters and municipality wastewaters.

  13. Synthetic resveratrol aliphatic acid inhibits TLR2-mediated apoptosis and an involvement of Akt/GSK3β pathway

    PubMed Central

    Chen, Lin; Zhang, Yi; Sun, Xiuli; Li, Hui; LeSage, Gene; Javer, Avani; Zhang, Xiumei; Wei, Xinbing; Jiang, Yulin; Yin, Deling

    2009-01-01

    As resveratrol derivatives, resveratrol aliphatic acids were synthesized in our laboratory. Previously, we reported the improved pharmaceutical properties of the compounds compared to resveratrol, including better solubility in water and much tighter binding with human serum albumin. Here, we investigate the role of resveratrol aliphatic acids in Toll-like receptor 2 (TLR2)-mediated apoptosis. We showed that resveratrol aliphatic acid (R6A) significantly inhibits the expression of TLR2. In addition, overexpression of TLR2 in HEK293 cells caused a significant decrease in apoptosis after R6A treatment. Moreover, inhibition of TLR2 by R6A decreases serum deprivation-reduced the levels of phosphorylated Akt and phosphorylated glycogen synthase kinase 3β (GSK3β). Our study thus demonstrates that the resveratrol aliphatic acid inhibits cell apoptosis through TLR2 by the involvement of Akt/GSK3β pathway. PMID:19477653

  14. Mechanisms and modeling of halogenated aliphatic contaminant adsorption by carbon nanotubes.

    PubMed

    Apul, Onur Guven; Zhou, Yang; Karanfil, Tanju

    2015-09-15

    This paper examines the adsorption of environmentally relevant halogenated aliphatic compounds using single-walled (SWCNT) and multi-walled carbon nanotubes (MWCNT), and the development of linear solvation-energy relationships (LSER) to examine those adsorption mechanisms. The poly-parameter LSER model was also compared to those previously generated for the adsorption of aromatic compounds by CNTs. The adsorption affinity of aliphatic compounds was greater on the SWCNT than MWCNT with similar oxygen contents. This was attributed to the pore-filling mechanism that was enhanced by higher micropore volume of the SWCNT bundles over the MWCNT bundles. LSER models showed that, at higher concentrations, B (the hydrogen bond accepting ability) was the most influential descriptor for both SWCNT and MWCNT. Other important descriptors were V followed by P, both of which exhibited a positive correlation with adsorption, indicating that their size and polarizability favors adsorption. The contribution of these descriptors to overall adsorption was 2-3 times less than the B. In comparison, V was the most important descriptor in the aromatic compound LSER models. This difference indicates that adsorbate hydrophobicity greatly affects the adsorption of aromatic compounds by CNTs, whereas, aliphatic compounds are affected by both the hydrophobic driving force and other interactions. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. 40 CFR 721.2270 - Aliphatic dicarboxylic acid salt.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Aliphatic dicarboxylic acid salt. 721... Substances § 721.2270 Aliphatic dicarboxylic acid salt. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as aliphatic dicarboxylic acid...

  16. 40 CFR 721.2270 - Aliphatic dicarboxylic acid salt.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Aliphatic dicarboxylic acid salt. 721... Substances § 721.2270 Aliphatic dicarboxylic acid salt. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as aliphatic dicarboxylic acid...

  17. 40 CFR 721.2270 - Aliphatic dicarboxylic acid salt.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Aliphatic dicarboxylic acid salt. 721... Substances § 721.2270 Aliphatic dicarboxylic acid salt. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as aliphatic dicarboxylic acid...

  18. 40 CFR 721.2270 - Aliphatic dicarboxylic acid salt.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Aliphatic dicarboxylic acid salt. 721... Substances § 721.2270 Aliphatic dicarboxylic acid salt. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as aliphatic dicarboxylic acid...

  19. 40 CFR 721.6140 - Dialkyldithiophosphoric acid, aliphatic amine salt.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., aliphatic amine salt. 721.6140 Section 721.6140 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.6140 Dialkyldithiophosphoric acid, aliphatic amine salt. (a) Chemical... as a dialkyldithiophosphoric acid, aliphatic amine salt (P-90-1839) is subject to reporting...

  20. 40 CFR 721.6140 - Dialkyldithiophosphoric acid, aliphatic amine salt.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., aliphatic amine salt. 721.6140 Section 721.6140 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.6140 Dialkyldithiophosphoric acid, aliphatic amine salt. (a) Chemical... as a dialkyldithiophosphoric acid, aliphatic amine salt (P-90-1839) is subject to reporting...

  1. 40 CFR 721.6140 - Dialkyldithiophosphoric acid, aliphatic amine salt.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., aliphatic amine salt. 721.6140 Section 721.6140 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.6140 Dialkyldithiophosphoric acid, aliphatic amine salt. (a) Chemical... as a dialkyldithiophosphoric acid, aliphatic amine salt (P-90-1839) is subject to reporting...

  2. 40 CFR 721.6140 - Dialkyldithiophosphoric acid, aliphatic amine salt.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., aliphatic amine salt. 721.6140 Section 721.6140 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.6140 Dialkyldithiophosphoric acid, aliphatic amine salt. (a) Chemical... as a dialkyldithiophosphoric acid, aliphatic amine salt (P-90-1839) is subject to reporting...

  3. 40 CFR 721.6140 - Dialkyldithiophosphoric acid, aliphatic amine salt.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., aliphatic amine salt. 721.6140 Section 721.6140 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.6140 Dialkyldithiophosphoric acid, aliphatic amine salt. (a) Chemical... as a dialkyldithiophosphoric acid, aliphatic amine salt (P-90-1839) is subject to reporting...

  4. 40 CFR 721.10534 - Brominated aliphatic alcohol (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Brominated aliphatic alcohol (generic... Specific Chemical Substances § 721.10534 Brominated aliphatic alcohol (generic). (a) Chemical substance and... aliphatic alcohol (PMN P-12-260) is subject to reporting under this section for the significant new...

  5. 40 CFR 721.10534 - Brominated aliphatic alcohol (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Brominated aliphatic alcohol (generic... Specific Chemical Substances § 721.10534 Brominated aliphatic alcohol (generic). (a) Chemical substance and... aliphatic alcohol (PMN P-12-260) is subject to reporting under this section for the significant new...

  6. 40 CFR 721.10199 - Substituted aliphatic amine (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Substituted aliphatic amine (generic... Specific Chemical Substances § 721.10199 Substituted aliphatic amine (generic). (a) Chemical substance and... aliphatic amine (PMN P-06-702) is subject to reporting under this section for the significant new...

  7. Compound

    NASA Astrophysics Data System (ADS)

    Suzumura, Akitoshi; Watanabe, Masaki; Nagasako, Naoyuki; Asahi, Ryoji

    2014-06-01

    Recently, Cu-based chalcogenides such as Cu3SbSe4, Cu2Se, and Cu2SnSe3 have attracted much attention because of their high thermoelectric performance and their common feature of very low thermal conductivity. However, for practical use, materials without toxic elements such as selenium are preferable. In this paper, we report Se-free Cu3SbS4 thermoelectric material and improvement of its figure of merit ( ZT) by chemical substitutions. Substitutions of 3 at.% Ag for Cu and 2 at.% Ge for Sb lead to significant reductions in the thermal conductivity by 37% and 22%, respectively. These substitutions do not sacrifice the power factor, thus resulting in enhancement of the ZT value. The sensitivity of the thermal conductivity to chemical substitutions in these compounds is discussed in terms of the calculated phonon dispersion and previously proposed models for Cu-based chalcogenides. To improve the power factor, we optimize the hole carrier concentration by substitution of Ge for Sb, achieving a power factor of 16 μW/cm K2 at 573 K, which is better than the best reported for Se-based Cu3SbSe4 compounds.

  8. Aliphatic and alicyclic camphor imines as effective inhibitors of influenza virus H1N1.

    PubMed

    Sokolova, Anastasiya S; Yarovaya, Оlga I; Baev, Dmitry S; Shernyukov, Аndrey V; Shtro, Anna A; Zarubaev, Vladimir V; Salakhutdinov, Nariman F

    2017-02-15

    A series of camphor derived imines was synthesised and evaluated in vitro for antiviral activity. Theoretical evaluations of ADME properties were also carried out. Most of these compounds exhibited significant activity against the drug-resistant strains of influenza A virus. Especially, compounds 2 (SI = 632) and 3 (SI = 417) presented high inhibition against influenza subtypes A/Puerto Rico/8/34 and A/California/07/09 of H1N1pdm09. Analysis of the structure-activity relationship showed that the activity was strongly dependent on the length of the aliphatic chain: derivatives with a shorter chain possessed higher activity, while the suppressing action of compounds with long aliphatic chains was lower.

  9. Fingerprinting aliphatic hydrocarbon pollutants over agricultural lands surrounding Tehran oil refinery.

    PubMed

    Bayat, Javad; Hashemi, Seyed Hossein; Khoshbakht, Korros; Deihimfard, Reza

    2016-11-01

    The analysis of aliphatic hydrocarbons, which are composed of n-alkanes as well as branched and cyclic alkanes, can be used to distinguish between the sources of hydrocarbon contamination. In this study, the concentration of aliphatic hydrocarbons, soil pH, and organic matter in agricultural soils located south of Tehran were monitored. Eighty-three soil samples were taken from two depth ranges of 0-30 and 30-60 cm. The results showed that aliphatic compounds ranged from 0.22-68.11 mg kg(-1) at the top to 0.33-53.18 mg kg(-1) at subsoil. The amount of hydrocarbons increases from the northern parts toward the south, and hydrocarbon pollutants originated from both petroleum and non-petroleum sources. Higher concentrations of aliphatic compounds in the southern parts indicated that, aside from the practice of irrigating with untreated wastewater, leakage from oil refinery storage tanks possibly contributed to soil pollution. The results also showed that several sources have polluted the agricultural soils. It is necessary to develop a new local pollution criterion as a diagnostic index that includes not only hydrocarbons but also other parameters such as heavy metal content in both soil and untreated wastewater, surface runoff, and other irrigation water resources to determine the exact origin of pollution.

  10. Renaissance of Aliphatic Polycarbonates: New Techniques and Biomedical Applications

    PubMed Central

    Xu, Jianwen; Feng, Ellva; Song, Jie

    2014-01-01

    Aliphatic polycarbonates were discovered a long time ago, with their conventional applications mostly limited to low molecular weight oligomeric intermediates for copolymerization with other polymers. Recent developments in polymerization techniques have overcome the difficulty in preparing high molecular weight aliphatic polycarbonates. These in turn, along with new functional monomers, have enabled the preparation of a wide range of aliphatic polycarbonates with diverse chemical compositions and structures. This review summarizes the latest polymerization techniques for preparing well-defined functional aliphatic polycarbonates, as well as the new applications of those aliphatic polycarbonates, esecially in the biomedical field. PMID:24994939

  11. Localized aliphatic organic material on the surface of Ceres.

    PubMed

    De Sanctis, M C; Ammannito, E; McSween, H Y; Raponi, A; Marchi, S; Capaccioni, F; Capria, M T; Carrozzo, F G; Ciarniello, M; Fonte, S; Formisano, M; Frigeri, A; Giardino, M; Longobardo, A; Magni, G; McFadden, L A; Palomba, E; Pieters, C M; Tosi, F; Zambon, F; Raymond, C A; Russell, C T

    2017-02-17

    Organic compounds occur in some chondritic meteorites, and their signatures on solar system bodies have been sought for decades. Spectral signatures of organics have not been unambiguously identified on the surfaces of asteroids, whereas they have been detected on cometary nuclei. Data returned by the Visible and InfraRed Mapping Spectrometer on board the Dawn spacecraft show a clear detection of an organic absorption feature at 3.4 micrometers on dwarf planet Ceres. This signature is characteristic of aliphatic organic matter and is mainly localized on a broad region of ~1000 square kilometers close to the ~50-kilometer Ernutet crater. The combined presence on Ceres of ammonia-bearing hydrated minerals, water ice, carbonates, salts, and organic material indicates a very complex chemical environment, suggesting favorable environments to prebiotic chemistry.

  12. Removal of volatile aliphatic hydrocarbons in a soil bioreactor

    SciTech Connect

    Kampbell, D.H.; Wilson, J.T.; Read, H.W.; Stocksdale, T.T.

    1987-01-01

    Soil removal of propane, isobutane and n-butane from a waste air stream was evaluated in the laboratory and in a prototype soil bioreactor. Laboratory investigations indicated first-order kinetics and the potential to degrade light aliphatic hydrocarbons and trichlorethylene, a compound ordinarily resistant to aerobic biological treatment. The predicted behavior of the bioreactor, based on laboratory studies, agreed closely with the actual behavior of the field system. The prototype bioreactor reduced the hydrocarbon concentrations in the air by at least 90% with a residence time of 15 minutes and a pressure drop of 85 cm of water. The bioreactor functioned well through a range of temperatures, 12C to 24C.

  13. Localized aliphatic organic material on the surface of Ceres

    NASA Astrophysics Data System (ADS)

    De Sanctis, M. C.; Ammannito, E.; McSween, H. Y.; Raponi, A.; Marchi, S.; Capaccioni, F.; Capria, M. T.; Carrozzo, F. G.; Ciarniello, M.; Fonte, S.; Formisano, M.; Frigeri, A.; Giardino, M.; Longobardo, A.; Magni, G.; McFadden, L. A.; Palomba, E.; Pieters, C. M.; Tosi, F.; Zambon, F.; Raymond, C. A.; Russell, C. T.

    2017-02-01

    Organic compounds occur in some chondritic meteorites, and their signatures on solar system bodies have been sought for decades. Spectral signatures of organics have not been unambiguously identified on the surfaces of asteroids, whereas they have been detected on cometary nuclei. Data returned by the Visible and InfraRed Mapping Spectrometer on board the Dawn spacecraft show a clear detection of an organic absorption feature at 3.4 micrometers on dwarf planet Ceres. This signature is characteristic of aliphatic organic matter and is mainly localized on a broad region of ~1000 square kilometers close to the ~50-kilometer Ernutet crater. The combined presence on Ceres of ammonia-bearing hydrated minerals, water ice, carbonates, salts, and organic material indicates a very complex chemical environment, suggesting favorable environments to prebiotic chemistry.

  14. Combinations of Aromatic and Aliphatic Radiolysis.

    PubMed

    LaVerne, Jay A; Dowling-Medley, Jennifer

    2015-10-08

    The production of H(2) in the radiolysis of benzene, methylbenzene (toluene), ethylbenzene, butylbenzene, and hexylbenzene with γ-rays, 2-10 MeV protons, 5-20 MeV helium ions, and 10-30 MeV carbon ions is used as a probe of the overall radiation sensitivity and to determine the relative contributions of aromatic and aliphatic entities in mixed hydrocarbons. The addition of an aliphatic side chain with progressively from one to six carbon lengths to benzene increases the H(2) yield with γ-rays, but the yield seems to reach a plateau far below that found from a simple aliphatic such as cyclohexane. There is a large increase in H(2) with LET (linear energy transfer) for all of the substituted benzenes, which indicates that the main process for H(2) formation is a second-order process and dominated by the aromatic entity. The addition of a small amount of benzene to cyclohexane can lower the H(2) yield from the value expected from a simple mixture law. A 50:50% volume mixture of benzene-cyclohexane has essentially the same H(2) yield as cyclohexylbenzene at a wide variation in LET, suggesting that intermolecular energy transfer is as efficient as intramolecular energy transfer.

  15. Three new aliphatic glycosides from the leaves of Antidesma japonicum Sieb. et Zucc.

    PubMed

    Iha, Ayumi; Matsunami, Katsuyoshi; Otsuka, Hideaki; Kawahata, Masatoshi; Yamaguchi, Kentaro; Takeda, Yoshio

    2012-10-01

    From the 1-BuOH-soluble fraction of an MeOH extract of leaves of Antidesma japonicum, three new aliphatic glycosides, α-L-arabinofuranosyl-(1 → 6)-β-D-glucopyranosides of (6R,9R)-megastigma-4,7-dien-9-ol-3-one, (Z)-hex-3-en-1-ol, and methyl 2-hydroxy-2-(1'-hydroxyethyl)pentanoate 1'-O-β-D-glucopyranoside, were isolated, along with seven known compounds.

  16. Kinetics of acid-catalyzed aldol condensation reactions of aliphatic aldehydes

    NASA Astrophysics Data System (ADS)

    Casale, Mia T.; Richman, Aviva R.; Elrod, Matthew J.; Garland, Rebecca M.; Beaver, Melinda R.; Tolbert, Margaret A.

    Field observations of atmospheric aerosols have established that organic compounds compose a large fraction of the atmospheric aerosol mass. However, the physical/chemical pathway by which organic compounds are incorporated into atmospheric aerosols remains unclear. The potential role of acid-catalyzed reactions of organic compounds on acidic aerosols has been explored as a possible chemical pathway for the incorporation of organic material into aerosols. In the present study, ultraviolet-visible (UV-vis) spectroscopy was used to monitor the kinetics of formation of the products of the acid-catalyzed aldol condensation reaction of a range of aliphatic aldehydes (C 2-C 8). The experiments were carried out at various sulfuric acid concentrations and a range of temperatures in order to estimate the rate constants of such reactions on sulfuric acid aerosols under tropospheric conditions. The rate constants were generally found to decrease as the chain length of the aliphatic aldehyde increased (except for acetaldehyde, which had an unusually small rate constant), increase as a function of sulfuric acid concentration as predicted by excess acidity theory, and showed normal Arrhenius behavior as a function of temperature. While the kinetic data are generally consistent with previous laboratory reports of aldehyde reactivity in various sulfuric acid media, the aldol condensation reactions involving aliphatic aldehydes do not appear fast enough to be responsible for significant transfer of organic material into atmospheric aerosols.

  17. Sodium hypochlorite oxidation of petroleum aliphatic contaminants in calcareous soils.

    PubMed

    Picard, François; Chaouki, Jamal

    2016-02-01

    This research project investigated the sodium hypochlorite (NaClO) oxidation of aliphatic petroleum contaminants (C10-C50) in a calcareous soil (average 5473 ppm C10-C50, 15 wt% Ca), which had been excavated from a contaminated industrial site. The decontamination objective was to lower the C10-C50 concentration to 700 ppm. CO2 acidity was used in the project to boost the NaClO oxidation yield and seems to have played a role in desorbing the natural organic matter. The experimental conditions were a 2- to 16-h reaction time, at room temperature, with a 1 to 12.5 wt% NaClO oxidative solution and a fixed 2:1 solution-to-soil ratio. With a 3 wt% NaClO solution and with a CO2 overhead, the NaClO dosage requirement was maintained below 60 g NaClO/g of oxidized C10-C50 over the entire decontamination range. The strong chlorine smell remaining after the reaction was completed suggests that part of the NaClO requirement can be recycled. Except traces of chloroform, there were no regulation-listed organochloride contaminants detected on either the treated soil samples or leachates and the total count of chlorinated compounds in treated soil samples was below the detection limit of 250 mg/kg. The NaClO oxidation mechanism on aliphatic substrates might be triggered by transition metals, such as manganese, but no attempt has been made to investigate the oxidation mechanism. Further investigations would include a constant-fed NaClO system and other techniques to lower the required NaClO dosage.

  18. Spreading coefficients of aliphatic hydrocarbons on water

    SciTech Connect

    Takii, Taichi; Mori, Y.H. . Dept. of Mechanical Engineering)

    1993-11-01

    Experiments have been performed to determine the equilibrium spreading coefficients of some aliphatic hydrocarbons (C[sub 6]C[sub 10]) on water. The thickness of a discrete lens of each hydrocarbon sample floating on a stagnant water pool was measured interferometrically and used to calculate the spreading coefficient of the hydrocarbon with the aid of Langmuir's capillarity theory. The dependences of the spreading coefficient, thus observed, on temperature (0--50 C) and on the number of carbon atoms in the hydrocarbon molecule are in qualitative agreement with the predictions based on the Lifshitz theory of van der Waals forces.

  19. Aliphatic hydrocarbons of the Murchison meteorite

    NASA Technical Reports Server (NTRS)

    Cronin, John R.; Pizzarello, Sandra

    1990-01-01

    Hydrocarbon fractions from the Murchison meteorite were prepared using benzene-methanol as the extraction solvent, fractionated on silica gel columns, and analyzed using gas chromatography combined with mass spectrometry and IR and NMR techniques. Results indicate that the most abundant aliphatic hydrocarbon components of the Murchison meteorite are C15 to C30 branched-alkyl-substituted mono-, di-, and tricyclic alkanes. It is shown that the n-alkanes, methyl alkanes, and isoprenoid alkanes that are sometimes found in extracts of the Murchison meteorite are terrestrial contaminants.

  20. Polycyclic aromatic and aliphatic hydrocarbons pollution at the coast of Aliağa (Turkey) ship recycling zone.

    PubMed

    Neşer, Gökdeniz; Kontas, Aynur; Unsalan, Deniz; Altay, Oya; Darılmaz, Enis; Uluturhan, Esin; Küçüksezgin, Filiz; Tekoğul, Nermin; Yercan, Funda

    2012-05-01

    Aliağa Bay is one of the most important maritime zones of Turkey where shipping activity, shipbreaking industry, steel works and petrochemical complexes exist together. Polycyclic aromatic hydrocarbons (PAHs) and aliphatic hydrocarbons in sediment of the Aliağa Bay were investigated to evaluate an environmental risk assessment from PAHs contamination in 2009-2010. Aliphatic and PAHs diagnostic ratios were showed to be mainly petroleum-originated and pyrolitic contaminations, respectively. The TEL/PEL analysis suggests that Aliağa sediments were likely to be contaminated by acutely toxic PAH compounds. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. Biodegradation of aliphatic and aromatic polycarbonates.

    PubMed

    Artham, Trishul; Doble, Mukesh

    2008-01-09

    Polycarbonate is one of the most widely used engineering plastics because of its superior physical, chemical, and mechanical properties. Understanding the biodegradation of this polymer is of great importance to answer the increasing problems in waste management of this polymer. Aliphatic polycarbonates are known to biodegrade either through the action of pure enzymes or by bacterial whole cells. Very little information is available that deals with the biodegradation of aromatic polycarbonates. Biodegradation is governed by different factors that include polymer characteristics, type of organism, and nature of pretreatment. The polymer characteristics such as its mobility, tacticity, crystallinity, molecular weight, the type of functional groups and substituents present in its structure, and plasticizers or additives added to the polymer all play an important role in its degradation. The carbonate bond in aliphatic polycarbonates is facile and hence this polymer is easily biodegradable. On the other hand, bisphenol A polycarbonate contains benzene rings and quaternary carbon atoms which form bulky and stiff chains that enhance rigidity. Even though this polycarbonate is amorphous in nature because of considerable free volume, it is non-biodegradable since the carbonate bond is inaccessible to enzymes because of the presence of bulky phenyl groups on either side. In order to facilitate the biodegradation of polymers few pretreatment techniques which include photo-oxidation, gamma-irradiation, or use of chemicals have been tested. Addition of biosurfactants to improve the interaction between the polymer and the microorganisms, and blending with natural or synthetic polymers that degrade easily, can also enhance the biodegradation.

  2. Biofiltration of gasoline and diesel aliphatic hydrocarbons.

    PubMed

    Halecky, Martin; Rousova, Jana; Paca, Jan; Kozliak, Evguenii; Seames, Wayne; Jones, Kim

    2015-02-01

    The ability of a biofilm to switch between the mixtures of mostly aromatic and aliphatic hydrocarbons was investigated to assess biofiltration efficiency and potential substrate interactions. A switch from gasoline, which consisted of both aliphatic and aromatic hydrocarbons, to a mixture of volatile diesel n-alkanes resulted in a significant increase in biofiltration efficiency, despite the lack of readily biodegradable aromatic hydrocarbons in the diesel mixture. This improved biofilter performance was shown to be the result of the presence of larger size (C₉-C(12)) linear alkanes in diesel, which turned out to be more degradable than their shorter-chain (C₆-C₈) homologues in gasoline. The evidence obtained from both biofiltration-based and independent microbiological tests indicated that the rate was limited by biochemical reactions, with the inhibition of shorter chain alkane biodegradation by their larger size homologues as corroborated by a significant substrate specialization along the biofilter bed. These observations were explained by the lack of specific enzymes designed for the oxidation of short-chain alkanes as opposed to their longer carbon chain homologues.

  3. Gaseous aliphatic aldehydes in Chinese incense smoke

    SciTech Connect

    Lin, J.M.; Wang, L.H. )

    1994-09-01

    Aliphatic aldehydes were found during the combustion of materials. Tobacco smoke contains aldehydes. Fire fighters were exposed to aldehydes when they conducted firefighting. Aldehydes in ambient air come mainly from the incomplete combustion of hydrocarbons and from photochemical reaction. Most aldehydes in ambient air are formaldehyde and acetaldehyde. Formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, and benzaldehyde were found in the atmosphere in Los Angeles. Burning Chinese incense for worshipping deities is a Chinese daily routine. It was suspected to be a factor causing nasopharynegeal cancer. Epidemiological studies correlated it with the high risk of childhood brain tumor and the high risk of childhood leukemia. Ames test identified the mutagenic effect of the smoke from burning Chinese incense. The smoke had bee proved to contain polycyclic aromatic hydrocarbons and aromatic aldehydes. Suspicion about formaldehyde and other alphatic aldehydes was evoked, when a survey of indoor air pollution was conducted in Taipei city. This study determined the presence of aliphatic aldehydes in the smoke from burning Chinese incense under a controlled atmosphere. 12 refs., 5 figs., 2 tabs.

  4. Multifunctional aliphatic polyester nanofibers for tissue engineering

    PubMed Central

    Zhan, Jianan; Singh, Anirudha; Zhang, Zhe; Huang, Ling; Elisseeff, Jennifer H.

    2012-01-01

    Electrospun fibers based on aliphatic polyesters, such as poly(ε-caprolactone) (PCL), have been widely used in regenerative medicine and drug delivery applications due to their biocompatibility, low cost and ease of fabrication. However, these aliphatic polyester fibers are hydrophobic in nature, resulting in poor wettability, and they lack functional groups for decorating the scaffold with chemical and biological cues. Current strategies employed to overcome these challenges include coating and blending the fibers with bioactive components or chemically modifying the fibers with plasma treatment and reactants. In the present study, we report on designing multifunctional electrospun nanofibers based on the inclusion complex of PCL-α-cyclodextrin (PCL-α-CD), which provides both structural support and multiple functionalities for further conjugation of bioactive components. This strategy is independent of any chemical modification of the PCL main chain, and electrospinning of PCL-α-CD is as easy as electrospinning PCL. Here, we describe synthesis of the PCL-α-CD electrospun nanofibers, elucidate composition and structure, and demonstrate the utility of functional groups on the fibers by conjugating a fluorescent small molecule and a polymeric-nanobead to the nanofibers. Furthermore, we demonstrate the application of PCL-α-CD nanofibers for promoting osteogenic differentiation of human adipose-derived stem cells (hADSCs), which induced a higher level of expression of osteogenic markers and enhanced production of extracellular matrix (ECM) proteins or molecules compared with control PCL fibers. PMID:23507886

  5. Triacylglycerols and aliphatic alcohols from fruits of three Tunisian Pistacia lentiscus populations.

    PubMed

    Trabelsi, Hajer; Renaud, Justin; Herchi, Wahid; Boukhchina, Sadok; Mayer, Paul

    2015-08-15

    The search for other sources of vegetable oils by the exploitation and the enhancement of other oil plants will be needed to meet the demands of the international market. This study aims to determine the triacylglycerol (TAG) molecular species and aliphatic alcohol compositions of unexploited fruits of three Tunisian Pistacia lentiscus (lentisc) populations from the Korbous, Tebaba and Rimel areas of Tunisia. Results show that the content of total TAG varies from 738.32 mg g(-1) of total lipid in the Tebaba population to 981.15 mg g(-1) of total lipid in the Korbous population. Furthermore, 14 species of TAG were detected in the three studied populations. In addition, 13 aliphatic compounds were identified and classified into two groups: (1) aliphatic alcohols with fewer than 20 carbon atoms (hexadecanol, heptadecanol, (Z)-octadec-9-en-1-ol, octadecanol and nonadécanol); and (2) the policosanol group (eicosenol, docosenol, docosanol tetracosanol, hexacosanol octacosanol and triacontanol). The Tebaba population showed a distinct composition compared to Korbous and Rimel where heptadecanol is the major compound. Quantitatively, the most abundant TAG species are those constituted by palmitic, oleic and/or linoleic acid. Furthermore, the significant difference observed at the oil composition is associated with a remarkable station effect. © 2014 Society of Chemical Industry.

  6. Friction of iron lubricated with aliphatic and aromatic hydrocarbons and halogenated analogs

    NASA Technical Reports Server (NTRS)

    Buckley, D. H.

    1976-01-01

    The influence of oxygen and various organic molecules on the reduction of the friction of an iron (011) single crystal surface was investigated. A comparison was made between aliphatic and aromatic structures, all of which contained six carbon atoms, and among various halogen atoms. Results of the investigation indicate that hexane and benzene give similar friction coefficients over a range of loads except at very light loads. At light loads, the friction decreased with an increase in the load where the halogens fluorine and chlorine are incorporated into the benzene molecular structure; however, over the same load range when bromine and iodine were present, the friction was relatively unchanged. The aliphatic compound chlorohexane exhibited lower friction coefficients than the aromatic structure chlorobenzene at very light loads. With the brominated benzene structures, however, friction was essentially the same. Oxygen was more effective in reducing friction than were the simple hydrocarbons.

  7. 40 CFR 721.4568 - Methylpolychloro aliphatic ketone.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Methylpolychloro aliphatic ketone. 721... Substances § 721.4568 Methylpolychloro aliphatic ketone. (a) Chemical substance and significant new uses... ketone (PMN No. P-91-1321) is subject to reporting under this section for the significant new uses...

  8. 40 CFR 721.2270 - Aliphatic dicarboxylic acid salt.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Aliphatic dicarboxylic acid salt. 721... Substances § 721.2270 Aliphatic dicarboxylic acid salt. (a) Chemical substance and significant new uses... salt (PMN P-92-1352) is subject to reporting under this section for the significant new uses...

  9. In-situ micro-FTIR Study of Thermal Changes of Organics in Tagish Lake Meteorite: Behavior of Aliphatic Oxygenated Functions and Effects of Minerals

    NASA Technical Reports Server (NTRS)

    Kebukawa, Yoko; Nakashima, Satoru; Nakamura-Messenger, Keiko; Zolensky, Michael E.

    2007-01-01

    Systematic in-situ FTIR heating experiments of Tagish Lake meteorite grains have been performed in order to study thermal stability of chondritic organics. Some aliphatic model organic substances have also been used to elucidate effects of hydrous phyllosilicate minerals on the thermal stability of organics. The experimental results indicated that organic matter in the Tagish Lake meteorite might contain oxygenated aliphatic hydrocarbons which are thermally stable carbonyls such as ester and/or C=O in ring compounds. The presence of hydrous phyllosilicate minerals has a pronounced effect on the increase of the thermal stability of aliphatic and oxygenated functions. These oxygenated aliphatic organics in Tagish Lake can be formed during the aqueous alteration in the parent body and the formation temperature condition might be less than 200 C, based especially on the thermal stability of C-O components. The hydrous phyllosilicates might provide sites for organic globule formation and protected some organic decomposition

  10. Validation of Alternatives to Aliphatic Isocyanate Polyurethanes

    NASA Technical Reports Server (NTRS)

    Curran, Jerome

    2007-01-01

    The National Aeronautics and Space Administration (NASA) Headquarters chartered the Acquisition Pollution Prevention (AP2) Office to coordinate agency activities affecting pollution prevention issues identified during system and component acquisition and sustainment processes. The primary objective of this effort is to demonstrate and validate alternatives to aliphatic isocyanate polyurethane coatings. Successful completion of this project will result in one or more isocyanate-free coating systems qualified for use at Air Force Space Command (AFSPC) and NASA centers participating in this study. The objective of this project is to qualify the candidates under the specifications for the standard system. This project will compare coating performance of the proposed alternatives to existing coating systems or standards.

  11. Energetics of aliphatic deletions in protein cores

    PubMed Central

    Bueno, Marta; Campos, Luis A.; Estrada, Jorge; Sancho, Javier

    2006-01-01

    Although core residues can sometimes be replaced by shorter ones without introducing significant changes in protein structure, the energetic consequences are typically large and destabilizing. Many efforts have been devoted to understand and predict changes in stability from analysis of the environment of mutated residues, but the relationships proposed for individual proteins have often failed to describe additional data. We report here 17 apoflavodoxin large-to-small mutations that cause overall protein destabilizations of 0.6–3.9 kcal.mol−1. By comparing two-state urea and three-state thermal unfolding data, the overall destabilizations observed are partitioned into effects on the N-to-I and on the I-to-U equilibria. In all cases, the equilibrium intermediate exerts a “buffering” effect that reduces the impact of the overall destabilization on the N-to-I equilibrium. The performance of several structure-energetics relationships, proposed to explain the energetics of hydrophobic shortening mutations, has been evaluated by using an apoflavodoxin data set consisting of 14 mutations involving branching-conservative aliphatic side-chain shortenings and a larger data set, including similar mutations implemented in seven model proteins. Our analysis shows that the stability changes observed for any of the different types of mutations (LA, IA, IV, and VA) in either data set are best explained by a combination of differential hydrophobicity and of the calculated volume of the modeled cavity (as previously observed for LA and IA mutations in lysozyme T4). In contrast, sequence conservation within the flavodoxin family, which is a good predictor for charge-reversal stabilizing mutations, does not perform so well for aliphatic shortening ones. PMID:16877708

  12. The Thermal Decomposition of Some Organic Lead Compounds

    DTIC Science & Technology

    1957-11-01

    5» Results 4 6. Discussion of Results 5 6.1 The Lead Salts of Aliphatic Aoids 5 6.2 The Lead Compounds of Aromatic Acids 7 6.3 Thermal...aliphatic carboxylic acids decompose to lead oxide in one stage which, in air, is largely oxidative in character. The compounds of the aromatic hydroxy... acids , however, first yield intermediate basio compounds of varying stability and these ultimately decompose to lead oxide at high temperatures

  13. Quantum descriptors for predictive toxicology of halogenated aliphatic hydrocarbons.

    PubMed

    Trohalaki, S; Pachter, R

    2003-04-01

    In order to improve Quantitative Structure-Activity Relationships (QSARs) for halogenated aliphatics (HA) and to better understand the biophysical mechanism of toxic response to these ubiquitous chemicals, we employ improved quantum-mechanical descriptors to account for HA electrophilicity. We demonstrate that, unlike the lowest unoccupied molecular orbital energy, ELUMO, which was previously used as a descriptor, the electron affinity can be systematically improved by application of higher levels of theory. We also show that employing the reciprocal of ELUMO, which is more consistent with frontier molecular orbital (FMO) theory, improves the correlations with in vitro toxicity data. We offer explanations based on FMO theory for a result from our previous work, in which the LUMO energies of HA anions correlated surprisingly well with in vitro toxicity data. Additional descriptors are also suggested and interpreted in terms of the accepted biophysical mechanism of toxic response to HAs and new QSARs are derived for various chemical categories that compose the data set employed. These alternate descriptors provide important insight and could benefit other classes of compounds where the biophysical mechanism of toxic response involves dissociative attachment.

  14. Aliphatic, Cyclic, and Aromatic Organic Acids, Vitamins, and Carbohydrates in Soil: A Review

    PubMed Central

    Vranova, Valerie; Rejsek, Klement; Formanek, Pavel

    2013-01-01

    Organic acids, vitamins, and carbohydrates represent important organic compounds in soil. Aliphatic, cyclic, and aromatic organic acids play important roles in rhizosphere ecology, pedogenesis, food-web interactions, and decontamination of sites polluted by heavy metals and organic pollutants. Carbohydrates in soils can be used to estimate changes of soil organic matter due to management practices, whereas vitamins may play an important role in soil biological and biochemical processes. The aim of this work is to review current knowledge on aliphatic, cyclic, and aromatic organic acids, vitamins, and carbohydrates in soil and to identify directions for future research. Assessments of organic acids (aliphatic, cyclic, and aromatic) and carbohydrates, including their behaviour, have been reported in many works. However, knowledge on the occurrence and behaviour of D-enantiomers of organic acids, which may be abundant in soil, is currently lacking. Also, identification of the impact and mechanisms of environmental factors, such as soil water content, on carbohydrate status within soil organic matter remains to be determined. Finally, the occurrence of vitamins in soil and their role in biological and biochemical soil processes represent an important direction for future research. PMID:24319374

  15. Aliphatic, cyclic, and aromatic organic acids, vitamins, and carbohydrates in soil: a review.

    PubMed

    Vranova, Valerie; Rejsek, Klement; Formanek, Pavel

    2013-11-10

    Organic acids, vitamins, and carbohydrates represent important organic compounds in soil. Aliphatic, cyclic, and aromatic organic acids play important roles in rhizosphere ecology, pedogenesis, food-web interactions, and decontamination of sites polluted by heavy metals and organic pollutants. Carbohydrates in soils can be used to estimate changes of soil organic matter due to management practices, whereas vitamins may play an important role in soil biological and biochemical processes. The aim of this work is to review current knowledge on aliphatic, cyclic, and aromatic organic acids, vitamins, and carbohydrates in soil and to identify directions for future research. Assessments of organic acids (aliphatic, cyclic, and aromatic) and carbohydrates, including their behaviour, have been reported in many works. However, knowledge on the occurrence and behaviour of D-enantiomers of organic acids, which may be abundant in soil, is currently lacking. Also, identification of the impact and mechanisms of environmental factors, such as soil water content, on carbohydrate status within soil organic matter remains to be determined. Finally, the occurrence of vitamins in soil and their role in biological and biochemical soil processes represent an important direction for future research.

  16. Chlorinated aliphatic and aromatic VOC decomposition in air mixture by using electron beam irradiation

    NASA Astrophysics Data System (ADS)

    Chmielewski, A. G.; Sun, Yong-Xia; Bułka, S.; Zimek, Z.

    2004-09-01

    Chlorinated aliphatic and aromatic hydrocarbons, which are emitted from coal power station and waste incinerators, are very harmful to the environment and human health. Recent studies show that chlorinated aliphatic and aromatic hydrocarbons are suspected to be the precursors of dioxin's formation. Dioxin's emission into atmosphere will cause severe environmental problems by ecology contamination. l,4-dichlorobenzene(l,4-DCB) and cis-dichloroethylene( cis-DCE) were chosen as representative chlorinated aromatic and aliphatic compounds, respectively. Their decomposition was investigated by electron beam irradiation. The experiments were carried out "in batch" system. It is found that over 97% cis-DCE is decomposed having an initial concentration of 661 ppm. G-values of cis-DCE decomposition vary from 10 to 28 (molecules/100 eV) for initial concentration of 270-1530 ppm cis-DCE. The decomposition is mainly caused by secondary electron attachment and Cl addition reactions. Comparing with cis-DCE, 1,4-DCB decomposition needs higher absorbed dose. G-value of 1,4-DCB is below 4 molecules/100 eV.

  17. Enzymatic degradation of aliphatic nitriles by Rhodococcus rhodochrous BX2, a versatile nitrile-degrading bacterium.

    PubMed

    Fang, Shumei; An, Xuejiao; Liu, Hongyuan; Cheng, Yi; Hou, Ning; Feng, Lu; Huang, Xinning; Li, Chunyan

    2015-06-01

    Nitriles are common environmental pollutants, and their removal has attracted increasing attention. Microbial degradation is considered to be the most acceptable method for removal. In this work, we investigated the biodegradation of three aliphatic nitriles (acetonitrile, acrylonitrile and crotononitrile) by Rhodococcus rhodochrous BX2 and the expression of their corresponding metabolic enzymes. This organism can utilize all three aliphatic nitriles as sole carbon and nitrogen sources, resulting in the complete degradation of these compounds. The degradation kinetics were described using a first-order model. The degradation efficiency was ranked according to t1/2 as follows: acetonitrile>trans-crotononitrile>acrylonitrile>cis-crotononitrile. Only ammonia accumulated following the three nitriles degradation, while amides and carboxylic acids were transient and disappeared by the end of the assay. mRNA expression and enzyme activity indicated that the tested aliphatic nitriles were degraded via both the inducible NHase/amidase and the constitutive nitrilase pathways, with the former most likely preferred. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Composites of vinyl polystyrylpyridine/bismaleimide-aliphatic ether copolymers

    NASA Technical Reports Server (NTRS)

    Heimbuch, Alvin H.; Rosser, Robert W.; Hsu, Ming-Ta S.

    1989-01-01

    An aliphatic ether bismaleimide was prepared and coreacted with a polyvinylstyrylpyridine (VPSP) oligomer. Studies showed that a controlled ratio of aliphatic to aromatic units in the polymer backbone improved both processibility and interlaminar shear properties for the carbon-fiber composite system. This modified resin was readily soluble in tetrahydrofuran, allowing for better fiber impregnation and thus enhancing adhesive properties and reproducibility. DSC studies have shown a lower cure temperature for the copolymer than for the neat aliphatic bismaleimide, and a glass transition temperature of 260 C, which is more than adequate for most applications. Limited measurements indicated an improvement in toughness (impact resistance).

  19. Metabolites of Aliphatic Alcohols Detected in Alcoholic Beverages Inhibit Phagocytosis.

    PubMed

    Árnyas, Ervin M; Pál, László; Baranyi, Gergő; Bujdosó, Orsolya; Rácz, Gábor; Ádány, Róza; McKee, Martin; Szűcs, Sándor

    2016-07-01

    The aim of our study was to measure granulocyte and monocyte phagocytosis following treatment of cells with some metabolites of aliphatic alcohols alone and in combination with acetaldehyde. The cells were separated from human peripheral blood prior to determination of phagocytosis of opsonized zymosan particles by granulocytes and monocytes treated individually with metabolites of aliphatic alcohols including formaldehyde, 1-propanal, acetone, 1-butanal, and 2-butanone and in combination with acetaldehyde. The findings revealed that metabolites of aliphatic alcohols inhibited phagocytosis by granulocytes and monocytes in a concentration-dependent manner and when combined with acetaldehyde, they caused a further decrease in phagocytic activity. Due to their additive effects, it is possible that, in combination with acetaldehyde, metabolites of aliphatic alcohols may inhibit phagocytosis at physiologically realistic concentrations in episodic heavy drinkers, thereby contributing to their increased susceptibility to infectious diseases. © The Author 2015. Medical Council on Alcohol and Oxford University Press. All rights reserved.

  20. Synthesis and Enzymatic Degradation of Soft Aliphatic Polyesters.

    PubMed

    Buchholz, Viola; Agarwal, Seema; Greiner, Andreas

    2016-02-01

    Novel aliphatic enzymatically degradable polyesters with short alkyl side chains for tuning crystallinity are presented in this work. The intrinsic problem of aliphatic polyesters is their brittleness and tendency to crystallize. This was modulated by the synthesis of random copolyesters based on aliphatic linear monomers, adipic acid, 1,5-pentanediol and monomers with aliphatic branches, such as 2-butyl-2-ethyl-1,3-propanediol by polycondensation. The resulting copolyesters were crystalline, wax-like or had liquid texture with varied mechanical properties and enzymatic degradability depending upon the copolymer composition. Such polyesters are of significant interest for a wide range of possible applications such as controlled drug delivery, agricultural applications and as packing materials. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Renewable Aliphatic Polyester Block Polymer Thermoplastic Elastomers

    NASA Astrophysics Data System (ADS)

    Martello, Mark Thomas

    The performance of thermoplastic elastomers is predicated on their ability to form mechanically tough physically crosslinked elastomeric networks at low temperatures and be able to flow at elevated temperatures. This dissertation focuses on renewable aliphatic polyester block polymers with amorphous polylactide (PLA) and their performance as TPEs. The goal of this work was to enhance the mechanical toughness of PLA containing TPEs; fundamental properties ranging from chemical composition and phase behavior, molecular architecture and melt processability, to melt polymerization strategies were investigated. ABA triblock polymers with PLA end-blocks and rubbery mid-blocks from substituted lactones comprised of poly(6-methyl-epsilon-caprolactone)(PMCL), poly(delta-decalactone), and poly(epsilon-decalactone)(PDL) were produced by sequential ring-opening polymerizations in the bulk. The bulk microstructure of symmetric PLA-PMCL-PLA and PLA-PDL-PLA triblock polymers formed long-range ordered morphologies and the interaction parameter of the repeat units was determined. High molar mass triblocks exhibited elastomeric behavior with good tensile strengths and high elongations. Small triblocks were coupled to produced (PLA-PDL-PLA)n multiblock polymers with high molar mass and accessible order-disorder transitions allowing for melt processing via injection molding. The mechanical toughness of the multiblocks was comparable to the high molar mass triblocks. The controlled polymerization of renewable delta-decalactone was accomplished with an organocatalyst at low temperatures in the bulk to maximize the equilibrium conversion of the monomer.

  2. Reduction of amphetamine hydroxylamine and other aliphatic hydroxylamines by benzamidoxime reductase and human liver microsomes.

    PubMed

    Clement, B; Behrens, D; Möller, W; Cashman, J R

    2000-10-01

    For the reduction of N-hydroxylated derivatives of strongly basic functional groups, such as amidines, guanidines, and aminohydrazones, an oxygen-insensitive liver microsomal system, the benzamidoxime reductase, has been described. To reconstitute the complete activity of the benzamidoxime reductase, the system required cytochrome b(5), NADH-cytochrome b(5)-reductase, and the benzamidoxime reductase, a cytochrome P450 enzyme, which has been purified to homogeneity from pig liver. It was not known if this enzyme system was also capable of reducing aliphatic hydroxylamines. The N-hydroxylation of aliphatic amines is a well-known metabolic process. It was of interest to study the possibility of benzamidoxime reductase reducing N-hydroxylated metabolites of aliphatic amines back to the parent compound. Overall, N-hydroxylation and reduction would constitute a futile metabolic cycle. As examples of medicinally relevant compounds, the hydroxylamines of methamphetamine, amphetamine, and N-methylamine as model compounds were investigated. Formation of methamphetamine and amphetamine was analyzed by newly developed HPLC methods. All three hydroxylamines were easily reduced by benzamidoxime reductase to their parent amines with reduction rates of 220.6 nmol min(-1) (mg of protein)(-1) for methamphetamine, 5.25 nmol min(-1) (mg of protein)(-1) for amphetamine, and 153 nmol min(-1) (mg of protein)(-1) for N-methylhydroxylamine. Administration of synthetic hydroxylamines of amphetamine and methamphetamine to primary rat neuronal cultures produced frank cell toxicity. Compared with amphetamine or the oxime of amphetamine, the hydroxylamines were significantly more toxic to primary neuronal cells. The benzamidoxime reductase is therefore involved in the detoxication of these reactive hydroxylamines.

  3. Process for producing peracids from aliphatic hydroxy carboxylic acids

    DOEpatents

    Chum, Helena L.; Ratcliff, Matthew A.; Palasz, Peter D.

    1986-01-01

    A process for producing peracids from lactic acid-containing solutions derived from biomass processing systems comprising: adjusting the pH of the solution to about 8-9 and removing alkaline residue fractions therefrom to form a solution comprised substantially of lower aliphatic hydroxy acids; oxidizing the solution to produce volatile lower aliphatic aldehydes; removing said aldehydes as they are generated; and converting said aldehydes to peracids.

  4. Process for producing peracids from aliphatic hydroxy carboxylic acids

    DOEpatents

    Chum, H.L.; Palasz, P.D.; Ratcliff, M.A.

    1984-12-20

    A process is described for producing peracids from lactic acid-containing solutions derived from biomass processing systems. It consists of adjusting the pH of the solution to about 8 to 9 and removing alkaline residue fractions therefrom to form a solution comprised substantially of lower aliphatic hydroxy acids. The solution is oxidized to produce volatile lower aliphatic aldehydes. The aldehydes are removed as they are generated and converted to peracids.

  5. Silver-Catalyzed Decarboxylative Bromination of Aliphatic Carboxylic Acids.

    PubMed

    Tan, Xinqiang; Song, Tao; Wang, Zhentao; Chen, He; Cui, Lei; Li, Chaozhong

    2017-03-13

    The silver-catalyzed Hunsdiecker bromination of aliphatic carboxylic acids is described. With Ag(Phen)2OTf as the catalyst and dibromoisocyanuric acid as the brominating agent, various aliphatic carboxylic acids underwent decarboxylative bromination to provide the corresponding alkyl bromides under mild conditions. This method not only is efficient and general but also enjoys wide functional group compatibility. An oxidative radical mechanism involving Ag(II) intermediates is proposed.

  6. Use of aliphatic hydrocarbons in feed to decrease body burdens of lipophilic toxicants in livestock

    SciTech Connect

    Rozman, K.; Rozman, T.; Griem, H.; Nieman, I.J.; Smith, G.S.

    1982-01-01

    Sheep were contaminated with hexachlorobenzene and then fed a conventional diet with or without 5% mineral oil or hexadecane. Similar to nonruminant species, both treatments enhanced fecal excretion of hexachlorobenzene about 3-fold and reduced levels of hexachlorobenzene stored in adipose tissue. Normal digestive functions of the animals, including fiber digestion by rumen microbes, were not affected by the administration of the aliphatic hydrocarbons. Dietary administration of mineral oil could be an inexpensive way to save livestock contaminated with toxic lipophilic compounds, such as many pesticides and industrial chemicals.

  7. Indigenous aliphatic amines in the aqueously altered Orgueil meteorite

    NASA Astrophysics Data System (ADS)

    Aponte, José C.; Dworkin, Jason P.; Elsila, Jamie E.

    2015-10-01

    The CI1 Orgueil meteorite is a highly aqueously altered carbonaceous chondrite. It has been extensively studied, and despite its extensive degree of aqueous alteration and some documented instances of contamination, several indigenous organic compounds including amino acids, carboxylic acids, and nucleobases have been detected in its carbon-rich matrix. We recently developed a novel gas chromatographic method for the enantiomeric and compound-specific isotopic analyses of meteoritic aliphatic monoamines in extracts and have now applied this method to investigate the monoamine content in Orgueil. We detected 12 amines in Orgueil, with concentrations ranging from 1.1 to 332 nmol g-1 of meteorite and compared this amine content in Orgueil with that of the CM2 Murchison meteorite, which experienced less parent-body aqueous alteration. Methylamine is four times more abundant in Orgueil than in Murchison. As with other species, the amine content in Orgueil extracts shows less structural diversity than that in Murchison extracts. We measured the compound-specific stable carbon isotopic ratios (δ13C) for 5 of the 12 monoamines detected in Orgueil and found a range of δ13C values from -20 to +59‰. These δ13C values fall into the range of other meteoritic organic compounds, although they are 13C-depleted relative to their counterparts extracted from the Murchison meteorite. In addition, we measured the enantiomeric composition for the chiral monoamines (R)- and (S)-sec-butylamine in Orgueil, and found it was racemic within experimental error, in contrast with the L-enantiomeric excess found for its amino acid structural analog isovaline. The racemic nature of sec-butylamine in Orgueil was comparable to that previously observed in Murchison, and to other CM2 and CR2 carbonaceous chondrites measured in this work (ALH 83100 [CM1/2], LON 94101 [CM2], LEW 90500 [CM2], LAP 02342 [CR2], and GRA 95229 [CR2]). These results allow us to place some constraints on the effects of

  8. Vacancy ion-exclusion/adsorption chromatography of aliphatic amines on a polymethacrylate-based weakly basic anion-exchange column.

    PubMed

    Mori, Masanobu; Helaleh, Murad I H; Xu, Qun; Hu, Wenzhi; Ikedo, Mikaru; Ding, Ming-Yu; Taoda, Hiroshi; Tanaka, Kazuhiko

    2004-06-11

    Vacancy ion-exclusion/adsorption chromatography has been applied to investigate the separation behavior of five aliphatic amines (ethylamine, propylamine, butylamine, pentylamine and hexylamine) on a polymethacrylate-based weakly basic anion-exchange column (Tosoh TSKgel DEAE-5PW). This system is consisted of analytes as a mobile phase and water as an injected sample. In the vacancy ion-exclusion/adsorption chromatography, the elution order was as follows: ethylamine < propylamine < butylamine < pentylamine < hexylamine, depending on their hydrophobicity. The retention times of the amines were decreased with decreasing their concentrations in the mobile phase. The retention times and resolutions of the amines were increased by adding a basic compound (e.g., lithium hydroxide or heptylamine) and by increasing the pH of mobile phase (pH > 11). This was because the dissociations of amine samples in the mobile phase were suppressed and thus the hydrophobic adsorption effects were enhanced. The linearity of calibration graphs could be obtained from the peak areas of the amine samples injected to the 0.05, 0.5 and 5 mM of amine mobile phase at pH 11 by heptylamine. The detection limits of aliphatic amines as injected samples were around 1 microM for five aliphatic amines at three different amine mobile phases. From these results, the retention behaviors of aliphatic amines on vacancy ion-exclusion/adsorption chromatography were concluded to be governed by the hydrophobic adsorption effect.

  9. The impact of the absence of aliphatic glucosinolates on water transport under salt stress in Arabidopsis thaliana

    PubMed Central

    Martínez-Ballesta, Mcarmen; Moreno-Fernández, Diego A.; Castejón, Diego; Ochando, Cristina; Morandini, Piero A.; Carvajal, Micaela

    2015-01-01

    Members of the Brassicaceae are known for their contents of nutrients and health-promoting phytochemicals, including glucosinolates. Exposure to salinity increases the levels of several of these compounds, but their role in abiotic stress response is unclear. The effect of aliphatic glucosinolates on plant water balance and growth under salt stress, involving aquaporins, was investigated by means of Arabidopsis thaliana mutants impaired in aliphatic glucosinolate biosynthesis, which is controlled by two transcription factors: Myb28 and Myb29. The double mutant myb28myb29, completely lacking aliphatic glucosinolates, was compared to wild type Col-0 (WT) and the single mutant myb28. A greater reduction in the hydraulic conductivity of myb28myb29 was observed under salt stress, when compared to the WT and myb28; this correlated with the abundance of both PIP1 and PIP2 aquaporin subfamilies. Also, changes in root architecture in response to salinity were genotype dependent. Treatment with NaCl altered glucosinolates biosynthesis in a similar way in WT and the single mutant and differently in the double mutant. The results indicate that short-chain aliphatic glucosinolates may contribute to water saving under salt stress. PMID:26236322

  10. Continuous-flow synthesis of primary amines: Metal-free reduction of aliphatic and aromatic nitro derivatives with trichlorosilane

    PubMed Central

    Porta, Riccardo; Colombo, Giacomo; Rossi, Sergio

    2016-01-01

    The metal-free reduction of nitro compounds to amines mediated by trichlorosilane was successfully performed for the first time under continuous-flow conditions. Aromatic as well as aliphatic nitro derivatives were converted to the corresponding primary amines in high yields and very short reaction times with no need for purification. The methodology was also extended to the synthesis of two synthetically relevant intermediates (precursors of baclofen and boscalid). PMID:28144331

  11. Pharmacological activities of cilantro's aliphatic aldehydes against Leishmania donovani.

    PubMed

    Donega, Mateus A; Mello, Simone C; Moraes, Rita M; Jain, Surendra K; Tekwani, Babu L; Cantrell, Charles L

    2014-12-01

    Leishmaniasis is a chronic infectious disease caused by different Leishmania species. Global occurrences of this disease are primarily limited to tropical and subtropical regions. Treatments are available; however, patients complain of side effects. Different species of plants have been screened as a potential source of new drugs against leishmaniasis. In this study, we investigated the antileishmanial activity of cilantro (Coriandrum sativum) essential oil and its main components: (E)-2-undecenal, (E)-2-decenal, (E)-2-dodecenal, decanal, dodecanal, and tetradecanal. The essential oil of C. sativum leaves inhibits growth of Leishmani donovani promastigotes in culture with an IC50 of 26.58 ± 6.11 µg/mL. The aliphatic aldehydes (E)-2-decenal (7.85 ± 0.28 µg/mL), (E)-2-undecenal (2.81 ± 0.21 µg/mL), and (E)-2-dodecenal (4.35 ± 0.15 µg/mL), all isolated from C. sativum essential oil, are effective inhibitors of in vitro cultures of L. donovani promastigotes. Aldehydes (E)-2-decenal, (E)-2-undecenal, and (E)-2-dodecenal were also evaluated against axenic amastigotes and IC50 values were determined to be 2.47 ± 0.25 µg/mL, 1.25 ± 0.11 µg/mL, and 4.78 ± 1.12 µg/mL, respectively. (E)-2-Undecenal and (E)-2-dodecenal demonstrated IC50 values of 5.65 ± 0.19 µg/mL and 9.60 ± 0.89 µg/mL, respectively, against macrophage amastigotes. These cilantro compounds showed no cytotoxicity against THP-1 macrophages.

  12. Process for reducing organic compounds with calcium, amine, and alcohol

    DOEpatents

    Benkeser, R.A.; Laugal, J.A.; Rappa, A.

    1985-08-06

    Olefins are produced by contacting an organic compound having at least one benzene ring with calcium metal, ethylenediamine, a low molecular weight aliphatic alcohol, and optionally a low molecular weight aliphatic primary amine, and/or an inert, abrasive particulate substance. The reduction is conducted at temperatures ranging from about [minus]10 C to about 30 C or somewhat higher. Substantially all of the organic compounds are converted to corresponding cyclic olefins, primarily diolefins.

  13. Process for reducing organic compounds with calcium, amine, and alcohol

    DOEpatents

    Benkeser, Robert A.; Laugal, James A.; Rappa, Angela

    1985-01-01

    Olefins are produced by contacting an organic compound having at least one benzene ring with calcium metal, ethylenediamine, a low molecular weight aliphatic alcohol, and optionally a low molecular weight aliphatic primary amine, and/or an inert, abrasive particulate substance. The reduction is conducted at temperatures ranging from about -10.degree. C. to about 30.degree. C. or somewhat higher. Substantially all of the organic compounds are converted to corresponding cyclic olefins, primarily diolefins.

  14. Aliphatic alcohols in spirits inhibit phagocytosis by human monocytes.

    PubMed

    Pál, László; Árnyas, Ervin M; Bujdosó, Orsolya; Baranyi, Gergő; Rácz, Gábor; Ádány, Róza; McKee, Martin; Szűcs, Sándor

    2015-04-01

    A large volume of alcoholic beverages containing aliphatic alcohols is consumed worldwide. Previous studies have confirmed the presence of ethanol-induced immunosuppression in heavy drinkers, thereby increasing susceptibility to infectious diseases. However, the aliphatic alcohols contained in alcoholic beverages might also impair immune cell function, thereby contributing to a further decrease in microbicidal activity. Previous research has shown that aliphatic alcohols inhibit phagocytosis by granulocytes but their effect on human monocytes has not been studied. This is important as they play a crucial role in engulfment and killing of pathogenic microorganisms and a decrease in their phagocytic activity could lead to impaired antimicrobial defence in heavy drinkers. The aim of this study was to measure monocyte phagocytosis following their treatment with those aliphatic alcohols detected in alcoholic beverages. Monocytes were separated from human peripheral blood and phagocytosis of opsonized zymosan particles by monocytes treated with ethanol and aliphatic alcohols individually and in combination was determined. It was shown that these alcohols could suppress the phagocytic activity of monocytes in a concentration-dependent manner and when combined with ethanol, they caused a further decrease in phagocytosis. Due to their additive effects, it is possible that they may inhibit phagocytosis in a clinically meaningful way in alcoholics and episodic heavy drinkers thereby contribute to their increased susceptibility to infectious diseases. However, further research is needed to address this question.

  15. Drude polarizable force field for aliphatic ketones and aldehydes, and their associated acyclic carbohydrates.

    PubMed

    Small, Meagan C; Aytenfisu, Asaminew H; Lin, Fang-Yu; He, Xibing; MacKerell, Alexander D

    2017-04-01

    The majority of computer simulations exploring biomolecular function employ Class I additive force fields (FF), which do not treat polarization explicitly. Accordingly, much effort has been made into developing models that go beyond the additive approximation. Development and optimization of the Drude polarizable FF has yielded parameters for selected lipids, proteins, DNA and a limited number of carbohydrates. The work presented here details parametrization of aliphatic aldehydes and ketones (viz. acetaldehyde, propionaldehyde, butaryaldehyde, isobutaryaldehyde, acetone, and butanone) as well as their associated acyclic sugars (D-allose and D-psicose). LJ parameters are optimized targeting experimental heats of vaporization and molecular volumes, while the electrostatic parameters are optimized targeting QM water interactions, dipole moments, and molecular polarizabilities. Bonded parameters are targeted to both QM and crystal survey values, with the models for ketones and aldehydes shown to be in good agreement with QM and experimental target data. The reported heats of vaporization and molecular volumes represent a compromise between the studied model compounds. Simulations of the model compounds show an increase in the magnitude and the fluctuations of the dipole moments in moving from gas phase to condensed phases, which is a phenomenon that the additive FF is intrinsically unable to reproduce. The result is a polarizable model for aliphatic ketones and aldehydes including the acyclic sugars D-allose and D-psicose, thereby extending the available biomolecules in the Drude polarizable FF.

  16. Drude polarizable force field for aliphatic ketones and aldehydes, and their associated acyclic carbohydrates

    NASA Astrophysics Data System (ADS)

    Small, Meagan C.; Aytenfisu, Asaminew H.; Lin, Fang-Yu; He, Xibing; MacKerell, Alexander D.

    2017-02-01

    The majority of computer simulations exploring biomolecular function employ Class I additive force fields (FF), which do not treat polarization explicitly. Accordingly, much effort has been made into developing models that go beyond the additive approximation. Development and optimization of the Drude polarizable FF has yielded parameters for selected lipids, proteins, DNA and a limited number of carbohydrates. The work presented here details parametrization of aliphatic aldehydes and ketones (viz. acetaldehyde, propionaldehyde, butaryaldehyde, isobutaryaldehyde, acetone, and butanone) as well as their associated acyclic sugars (uc(d)-allose and uc(d)-psicose). LJ parameters are optimized targeting experimental heats of vaporization and molecular volumes, while the electrostatic parameters are optimized targeting QM water interactions, dipole moments, and molecular polarizabilities. Bonded parameters are targeted to both QM and crystal survey values, with the models for ketones and aldehydes shown to be in good agreement with QM and experimental target data. The reported heats of vaporization and molecular volumes represent a compromise between the studied model compounds. Simulations of the model compounds show an increase in the magnitude and the fluctuations of the dipole moments in moving from gas phase to condensed phases, which is a phenomenon that the additive FF is intrinsically unable to reproduce. The result is a polarizable model for aliphatic ketones and aldehydes including the acyclic sugars uc(d)-allose and uc(d)-psicose, thereby extending the available biomolecules in the Drude polarizable FF.

  17. Kinetics of Acid-Catalyzed Aldol Condensation Reactions of Aliphatic Aldehydes

    NASA Astrophysics Data System (ADS)

    Elrod, M. J.; Casale, M. T.; Richman, A. R.; Beaver, M. R.; Garland, R. M.; Tolbert, M. A.

    2006-12-01

    While it is well established that organic compounds compose a large fraction of the atmospheric aerosol mass, the mechanisms through which organics are incorporated into atmospheric aerosols are not well understood. Acid-catalyzed reactions of compounds with carbonyl groups have recently been suggested as important pathways for transfer of volatile organics into acidic aerosols. In the present study, ultraviolet-visible (UV-Vis) spectroscopy was used to monitor the kinetics of formation of the products of the aldol condensation reaction of a range of aliphatic aldehydes (C2-C8) The experiments were carried out at various sulfuric acid concentrations and a range of temperatures in order to estimate the rate constants of such reactions on sulfuric acid aerosols under tropospheric conditions. The rate constants were generally found to decrease as the chain length of the aliphatic aldehyde increased (except for acetaldehyde, which had an unusually small rate constant), increase as a function of sulfuric acid concentration as predicted by excess acidity theory, and showed normal Arrhenius behavior as a function of temperature.

  18. Correlation between NQR parameters and residue size of aliphatic amino acids and their dimers.

    PubMed

    Ghaderi, Ali Reza; Sabzyan, Hassan; Hadipour, Nasser L

    2006-03-01

    Nuclear quadrupole coupling constants (NQCC), chi, and asymmetry parameters, eta, of 2D, 14N and 17O nuclei have been calculated for aliphatic amino acids and their dimers using MP2/6-311++G** method to shed some light on the differences between the structural parameters in the aliphatic amino acids and their dimers. For this purpose, electric field gradient (EFG) at the sites of quadrupolar nuclei have been calculated and evaluated for each compound. A correlation is observed between the calculated NQCC parameters and the conformational structures of the compounds, showing that extraction of structural data from the NQR spectra might be promising. Our results showed that 17O NQCC of terminal carboxylic acid and 14N NQCC of the terminal amino groups are, respectively, the least and the most sensitive parameters to the variation of the size of the residue. It is found also that conformation of R (i.e. values of the dihedral angles) plays a very effective role in the determination of the values of the calculated NQCC parameters. Sensitivity of the NQR parameters to the changes in the conformational structure is significantly greater (nearly 20-fold) than that to the changes in the other structural parameters such as bond lengths.

  19. Drude polarizable force field for aliphatic ketones and aldehydes, and their associated acyclic carbohydrates

    NASA Astrophysics Data System (ADS)

    Small, Meagan C.; Aytenfisu, Asaminew H.; Lin, Fang-Yu; He, Xibing; MacKerell, Alexander D.

    2017-04-01

    The majority of computer simulations exploring biomolecular function employ Class I additive force fields (FF), which do not treat polarization explicitly. Accordingly, much effort has been made into developing models that go beyond the additive approximation. Development and optimization of the Drude polarizable FF has yielded parameters for selected lipids, proteins, DNA and a limited number of carbohydrates. The work presented here details parametrization of aliphatic aldehydes and ketones (viz. acetaldehyde, propionaldehyde, butaryaldehyde, isobutaryaldehyde, acetone, and butanone) as well as their associated acyclic sugars ( d-allose and d-psicose). LJ parameters are optimized targeting experimental heats of vaporization and molecular volumes, while the electrostatic parameters are optimized targeting QM water interactions, dipole moments, and molecular polarizabilities. Bonded parameters are targeted to both QM and crystal survey values, with the models for ketones and aldehydes shown to be in good agreement with QM and experimental target data. The reported heats of vaporization and molecular volumes represent a compromise between the studied model compounds. Simulations of the model compounds show an increase in the magnitude and the fluctuations of the dipole moments in moving from gas phase to condensed phases, which is a phenomenon that the additive FF is intrinsically unable to reproduce. The result is a polarizable model for aliphatic ketones and aldehydes including the acyclic sugars d-allose and d-psicose, thereby extending the available biomolecules in the Drude polarizable FF.

  20. Atmospheric reactivity studies of aliphatic amines

    USDA-ARS?s Scientific Manuscript database

    Ambient studies of particulate matter have shown that alkyl amines are often present in particles in areas impacted by agricultural emissions. These locations include California’s Central Valley and Inland Empire and Utah’s Cache Valley. These compounds are not typically observed in airsheds that so...

  1. Different aliphatic dicarboxylates affected assemble of new coordination polymers constructed from flexible-rigid mixed ligands

    SciTech Connect

    Xu Xinxin; Ma Ying; Wang Enbo

    2007-11-15

    In this article, seven coordination polymers: [Cd(C{sub 5}H{sub 6}O{sub 4})(C{sub 10}H{sub 8}N{sub 2})]{sub n} (1), [Zn(C{sub 5}H{sub 6}O{sub 4})(C{sub 10}H{sub 8}N{sub 2})]{sub n} (2), [Cd(C{sub 6}H{sub 8}O{sub 4})(C{sub 10}H{sub 8}N{sub 2})]{sub n} (3), {l_brace}[Mn(C{sub 10}H{sub 8}N{sub 2})(H{sub 2}O){sub 4}] (C{sub 4}H{sub 4}O{sub 4}).4H{sub 2}O{r_brace}{sub n} (4), [Mn{sub 5}(C{sub 4}H{sub 4}O{sub 4}){sub 4}(O)]{sub n} (5), [Cd(C{sub 4}H{sub 4}O{sub 4})(C{sub 10}H{sub 8}N{sub 2})(H{sub 2}O)]{sub n} (6) and [Zn(C{sub 6}H{sub 6}O{sub 4})(C{sub 12}H{sub 8}N{sub 2})(H{sub 2}O)]{sub n} (7) were synthesized and characterized by single-crystallographic X-ray diffraction. Compounds 1 and 2 are two-dimensional layers connected by glutarate anions and 4,4'-bpy. Unlike compounds 1 and 2, compound 3 is a two-fold interpenetration network. Compound 4 is a one-dimensional chain-like structure, which is further extended to two-dimensional supramolecular layer structure with hydrogen bond. During the synthesis of compound 4, to our surprise, we got compound 5; compound 5 is an interesting three-dimensional network composed of pentanuclear Mn(II) building units and succinate anions. Compound 6 is also a two-dimensional supramolecular layer structure composed of one-dimensional chain-like structure with hydrogen bonds and {pi}-{pi} interactions. Compound 7 is also a one-dimensional chain-like structure, which is further connected with the same kind of interaction to generate two-dimensional supramolecular layer structure. Furthermore, compounds 1 and 2 both exhibit fluorescent property at room temperature. - Graphical abstract: Seven complexes composed by 3D metal ions, aliphatic acid ligand and rigid bidentate nitrogen ligands: 4,4'-bpy, 2,2'-bpy and 1,10'-phen. With the change of the carbon number of the backbone of aliphatic dicarboxylate ligand, we can synthesize different complexes with various structures.

  2. Design, synthesis and cytotoxic activities of novel aliphatic amino-substituted flavonoids.

    PubMed

    Liu, Guannan; Ge, Zhen; Zhao, Mengdan; Zhou, Yifeng

    2013-11-13

    A series of flavonoids 9a-f, 13b, 13d, 13e and 14a-f bearing diverse aliphatic amino moieties were designed, synthesized and evaluated for their cytotoxic activities against the ECA-109, A-549, HL-60, and PC-3 cancer cell lines. Most of the compounds exhibited moderate to good activities. The structure-activity relationships were studied, revealing that the chalcone skeleton is the most preferable for cytotoxic activities. Chalcone 9d was the most promising compound due to its high potency against the examined cancer cell lines (its IC₅₀ values against ECA-109, A549, HL-60 and PC-3 cells were 1.0, 1.5, 0.96 and 3.9 μM, respectively).

  3. Synthesis, characterization and antimicrobial studies of new bispyrazolines linked via 3-aryl ring with aliphatic chains

    NASA Astrophysics Data System (ADS)

    Yusuf, Mohamad; Jain, Payal

    2012-10-01

    The bispyrazolines 4a(a'-f') and 4b(a'-f') built around the aliphatic chains of varying lengths have been prepared by refluxing bischalcones 3a(a'-f') and 3b(a'-f') with phenyl hydrazine in alcoholic medium. The reactions of chalcones 2a and 2b with suitable 1,ω-dibromoalkanes in the presence of anhydrous K2CO3/dry acetone and Bu4N+I- (PTC) provided 3a(a'-f') and 3b(a'-f'), respectively. The antibacterial and antifungal activities of the synthesized compounds were evaluated against five bacterial and four fungal strains. The compounds 3ba', 3bc', 3bd', 3be', 3af', 4aa' and 4ba' showed better MIC (μg/mL) against the tested microorganisms.

  4. Catalytic Asymmetric Hydroamination of Unactivated Internal Olefins to Aliphatic Amines

    PubMed Central

    Yang, Yang; Shi, Shi-Liang; Niu, Dawen; Liu, Peng; Buchwald, Stephen L.

    2015-01-01

    Catalytic assembly of enantiopure aliphatic amines from abundant and readily available precursors has long been recognized as a paramount challenge in synthetic chemistry. Herein, we describe a mild and general copper-catalyzed hydroamination that effectively converts unactivated internal olefins, an important yet unexploited class of abundant feedstock chemicals, into highly enantioenriched α-branched amines (≥ 96% enantiomeric excess) featuring two minimally differentiated aliphatic substituents. This method provides a powerful means to access a broad range of advanced, highly functionalized enantioenriched amines of interest in pharmaceutical research and other areas. PMID:26138973

  5. Synthesis of organic phenothiazine-based molecular glasses and effect of racemic/homochiral aliphatic chain on near-infrared photorefractive property

    NASA Astrophysics Data System (ADS)

    Liu, Yingliang; Fujimura, Ryushi; Ishida, Kazuki; Oya, Nobuhiro; Yoshie, Naoko; Shimura, Tsutomu; Kuroda, Kazuo

    2012-09-01

    Organic near-infrared photorefractive molecular glasses with a phenothiazine moiety are designed and synthesized through the introduction of linear, racemic/homochiral asymmetrically branched aliphatic chains into photorefractive chromophore as an auxiliary group. The compounds are characterized with 1H-NMR, IR, FAB-MS, UV-vis, TG, DSC, etc. The effect of different aliphatic chains on the absorption and thermal properties is investigated in detail. The molar absorption coefficiency at the absorption maximum wavelength showed that the homochiral asymmetrically branched aliphatic chain has a strong hypochromic effect in the dilute solution when it is introduced into photorefractive chromophore. The DSC measurement indicated that the introduction of asymmetrically branched aliphatic chain is the key issue to design organic molecular glasses whether it is racemic or homochiral. The effect of racemic/homochiral asymmetrically branched aliphatic groups on photorefractive property is investigated carefully with poly(N-vinylcarbazole) (PVK) as a photoconductor and with (2,4,7-trinitro-9-fluorenylidene) malononitrile (TNFM) as a photosensitizer. The results suggested that the racemic group is more beneficial to the improvement of photorefractive performance than the homochiral when the homochiral cannot induce rigid photorefractive chromophore to be much more ordered.

  6. Aliphatic and polycyclic aromatic hydrocarbons in the surface sediments of the Mediterranean: assessment and source recognition of petroleum hydrocarbons.

    PubMed

    El Nemr, Ahmed; El-Sadaawy, Manal M; Khaled, Azza; Draz, Suzanne O

    2013-06-01

    Coastal marine sediment samples were collected from ten sampling stations along the Egyptian Mediterranean coast in April 2010. All sediment samples were analyzed for aliphatic (C7 to C34) and polycyclic aromatic hydrocarbons (PAHs) as well as total organic carbon (TOC) contents and grain size analysis. Total aliphatic hydrocarbons ranged from 1621.82 to 9069.99 ng/g (dry weight), while aromatic hydrocarbons (16 PAHs) varied between 208.69 and 1020.02 ng/g with an average of 530.68 ± 225.86 ng/g dwt. Good correlations observed between certain PAH concentrations allowed to identify its origin. The average TOC percent was varied from 0.13 to 1.46 %. Principal component analysis was used to determine the sources of hydrocarbon pollutants in sediments of Mediterranean. Additionally, special PAHs compound ratios suggest the petrogenic origins.

  7. Sulfonyl fluorides as alternative to sulfonyl chlorides in parallel synthesis of aliphatic sulfonamides.

    PubMed

    Bogolubsky, Andrey V; Moroz, Yurii S; Mykhailiuk, Pavel K; Pipko, Sergey E; Konovets, Anzhelika I; Sadkova, Irina V; Tolmachev, Andrey

    2014-04-14

    Two types of aliphatic sulfonyl halides (Cl versus F) were compared in parallel synthesis of sulfonamides derived from aliphatic amines. Aliphatic sulfonyl fluorides showed good results with amines bearing an additional functionality, while the corresponding chlorides failed. Both sulfonyl halides were effective in the reactions with amines having an easily accessible amino group. Aliphatic sulfonyl chlorides reacted efficiently with amines bearing sterically hindered amino group while the corresponding fluorides showed low activity.

  8. Suppression of the Ethanol Withdrawal Syndrome by Aliphatic Diols

    DTIC Science & Technology

    1979-06-07

    Two halogenated hydrocarbons , alcohols exert their intoxicating properties through an interac- which are amphiphiles like alcohols and diols, were both...induce a virtually identical spectrum of phatic hydrocarbons could not. The data suggest that short- intoxication signs. Because of their pharmacological...their ability to induce to determine if partitioning into membrasps is an important intoxication since 1) alcohols and aliphatic hydrocarbons with

  9. Aromatics versus aliphatics: revealing the structure of carbonaceous dust.

    NASA Astrophysics Data System (ADS)

    Peeters, Els

    2014-10-01

    The mid-IR spectra of almost all objects are dominated by strong emission bands at 3.3, 6.2, 7.7, 8.6, and 11.3 micron due to Polycyclic Aromatic Hydrocarbon molecules (PAHs). It is now well established that these mid-IR bands show clear variations in shape and peak position from one point source to another, as well as varying spatially within extended sources. The spectral diversity of the PAH band profiles reveals the nature of the carriers and hence allows one to study their formation and evolution throughout their life cycle. Although the origin of the profile variations is still under debate, the observations point towards a varying importance of aliphatics versus aromatics in the carrier molecules. We propose to obtain FLITECAM observations of sources showing extreme red B or C profiles and FORCAST observations of a source with an unusually strong 3.4 micron aliphatic band. Combined with previous results, the proposed observations are particularly suited to systematically investigate the connection between the PAH band profiles and the aliphatic emission bands at 3.4, 6.85 and 7.2 microns. These results will paint a necessary picture of the aromatic and aliphatic characteristics of the carbonaceous material and hence provide important clues on the origin of the PAH band profile variations.

  10. Degradation Characterization of Aliphatic POLYESTERS—IN Vitro Study

    NASA Astrophysics Data System (ADS)

    Vieira, A. C.; Vieira, J. C.; Guedes, R. M.; Marques, A. T.

    2008-08-01

    The most popular and important biodegradable polymers are aliphatic polyesters, such as polylactic acid (PLA), polyglycolic acid (PGA), polycaprolactone (PCL), polyhydoxyalkanoates (PHA's) and polyethylene oxide (PEO). However, each of these has some shortcomings which restrict its applications. Blending techniques are an extremely promising approach which can improve or tune the original properties of the polymers[1]. Aliphatic polyesters are a central class of biodegradable polymers, because hydrolytic and/or enzymatic chain cleavage of these materials leads to α-hydroxyacids, which in most cases are ultimately metabolized in human body. This is particularly useful for controlled release devices and for other biomedical applications like suture fibers and ligaments. For aliphatic polyesters, hydrolysis rates are affected by the temperature, molecular structure, and ester group density as well as by the species of enzyme used. The degree of crystallinity may be a crucial factor, since enzymes attack mainly the amorphous domains of a polymer. Four different aliphatic polyesters were characterized in terms of degradation. Sutures fibers of PGA-PCL, PGA, PLA-PCL and PDO were used in this study. Weight loss, pH, molecular weight, crystallinity and strength were measured after six stages of incubation in distilled water, physiological saline and phosphate buffer solution (PBS). Degradation rate was determined, using a first order kinetic equation for all materials in the three incubation media. A relatively wide range of mechanical properties and degradation rates were observed among the materials studied. PBS was the most aggressive environment for the majority of cases.

  11. 40 CFR 721.10199 - Substituted aliphatic amine (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... aliphatic amine (PMN P-06-702) is subject to reporting under this section for the significant new uses...-specific cartridge) and should include a particulate filter (N100 if oil aerosols are absent, R100, or P100... (HEPA) filters; supplied-air respirator operated in pressure demand or continuous flow mode and...

  12. 40 CFR 721.10199 - Substituted aliphatic amine (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... aliphatic amine (PMN P-06-702) is subject to reporting under this section for the significant new uses...-specific cartridge) and should include a particulate filter (N100 if oil aerosols are absent, R100, or P100... (HEPA) filters; supplied-air respirator operated in pressure demand or continuous flow mode and...

  13. 40 CFR 721.10199 - Substituted aliphatic amine (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... aliphatic amine (PMN P-06-702) is subject to reporting under this section for the significant new uses...-specific cartridge) and should include a particulate filter (N100 if oil aerosols are absent, R100, or P100... (HEPA) filters; supplied-air respirator operated in pressure demand or continuous flow mode and...

  14. A thermostable transketolase evolved for aliphatic aldehyde acceptors.

    PubMed

    Yi, Dong; Saravanan, Thangavelu; Devamani, Titu; Charmantray, Franck; Hecquet, Laurence; Fessner, Wolf-Dieter

    2015-01-11

    Directed evolution of the thermostable transketolase from Geobacillus stearothermophilus based on a pH-based colorimetric screening of smart libraries yielded several mutants with up to 16-fold higher activity for aliphatic aldehydes and high enantioselectivity (>95% ee) in the asymmetric carboligation step.

  15. Introducing Aliphatic Substitution with a Discovery Experiment Using Competing Electrophiles

    ERIC Educational Resources Information Center

    Curran, Timothy P.; Mostovoy, Amelia J.; Curran, Margaret E.; Berger, Clara

    2016-01-01

    A facile, discovery-based experiment is described that introduces aliphatic substitution in an introductory undergraduate organic chemistry curriculum. Unlike other discovery-based experiments that examine substitution using two competing nucleophiles with a single electrophile, this experiment compares two isomeric, competing electrophiles…

  16. Introducing Aliphatic Substitution with a Discovery Experiment Using Competing Electrophiles

    ERIC Educational Resources Information Center

    Curran, Timothy P.; Mostovoy, Amelia J.; Curran, Margaret E.; Berger, Clara

    2016-01-01

    A facile, discovery-based experiment is described that introduces aliphatic substitution in an introductory undergraduate organic chemistry curriculum. Unlike other discovery-based experiments that examine substitution using two competing nucleophiles with a single electrophile, this experiment compares two isomeric, competing electrophiles…

  17. Cloud condensation nuclei activity of aliphatic amine secondary aerosol

    USDA-ARS?s Scientific Manuscript database

    Aliphatic amines can form secondary aerosol via oxidation with atmospheric radicals (e.g. hydroxyl radical and nitrate radical). The resulting particle composition can contain both secondary organic aerosol (SOA) and inorganic salts. The fraction of organic to inorganic materials in the particulate ...

  18. 40 CFR 721.7250 - Polyaziridinyl ester of an aliphatic alcohol (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Polyaziridinyl ester of an aliphatic... Specific Chemical Substances § 721.7250 Polyaziridinyl ester of an aliphatic alcohol (generic). (a... generically as a polyaziridinyl ester of an aliphatic alcohol (PMN P-01-97) is subject to reporting under this...

  19. 40 CFR 721.2098 - Aliphatic polycarboxylic acid metal salt (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Aliphatic polycarboxylic acid metal... Specific Chemical Substances § 721.2098 Aliphatic polycarboxylic acid metal salt (generic). (a) Chemical... as an aliphatic polycarboxylic acid metal salt (PMN P-01-7) is subject to reporting under this...

  20. 40 CFR 721.2098 - Aliphatic polycarboxylic acid metal salt (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Aliphatic polycarboxylic acid metal... Specific Chemical Substances § 721.2098 Aliphatic polycarboxylic acid metal salt (generic). (a) Chemical... as an aliphatic polycarboxylic acid metal salt (PMN P-01-7) is subject to reporting under this...

  1. 40 CFR 721.2098 - Aliphatic polycarboxylic acid metal salt (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Aliphatic polycarboxylic acid metal... Specific Chemical Substances § 721.2098 Aliphatic polycarboxylic acid metal salt (generic). (a) Chemical... as an aliphatic polycarboxylic acid metal salt (PMN P-01-7) is subject to reporting under this...

  2. 40 CFR 721.2098 - Aliphatic polycarboxylic acid metal salt (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Aliphatic polycarboxylic acid metal... Specific Chemical Substances § 721.2098 Aliphatic polycarboxylic acid metal salt (generic). (a) Chemical... as an aliphatic polycarboxylic acid metal salt (PMN P-01-7) is subject to reporting under this...

  3. 40 CFR 721.2098 - Aliphatic polycarboxylic acid metal salt (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Aliphatic polycarboxylic acid metal... Specific Chemical Substances § 721.2098 Aliphatic polycarboxylic acid metal salt (generic). (a) Chemical... as an aliphatic polycarboxylic acid metal salt (PMN P-01-7) is subject to reporting under this...

  4. 40 CFR 721.7250 - Polyaziridinyl ester of an aliphatic alcohol (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Polyaziridinyl ester of an aliphatic... Specific Chemical Substances § 721.7250 Polyaziridinyl ester of an aliphatic alcohol (generic). (a... generically as a polyaziridinyl ester of an aliphatic alcohol (PMN P-01-97) is subject to reporting under...

  5. 40 CFR 721.10289 - Hexanedioic acid polymer with aliphatic polyol dihydrogen phosphate aromatic ester (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... aliphatic polyol dihydrogen phosphate aromatic ester (generic). 721.10289 Section 721.10289 Protection of... polymer with aliphatic polyol dihydrogen phosphate aromatic ester (generic). (a) Chemical substance and... acid polymer with aliphatic polyol dihydrogen phosphate aromatic ester (PMN P-11-333) is subject to...

  6. 40 CFR 721.10289 - Hexanedioic acid polymer with aliphatic polyol dihydrogen phosphate aromatic ester (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... aliphatic polyol dihydrogen phosphate aromatic ester (generic). 721.10289 Section 721.10289 Protection of... polymer with aliphatic polyol dihydrogen phosphate aromatic ester (generic). (a) Chemical substance and... acid polymer with aliphatic polyol dihydrogen phosphate aromatic ester (PMN P-11-333) is subject to...

  7. 40 CFR 721.10289 - Hexanedioic acid polymer with aliphatic polyol dihydrogen phosphate aromatic ester (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... aliphatic polyol dihydrogen phosphate aromatic ester (generic). 721.10289 Section 721.10289 Protection of... polymer with aliphatic polyol dihydrogen phosphate aromatic ester (generic). (a) Chemical substance and... acid polymer with aliphatic polyol dihydrogen phosphate aromatic ester (PMN P-11-333) is subject to...

  8. 40 CFR 721.10608 - Aliphatic diisocyanate polymer with alkanediol and alkylglycol (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Aliphatic diisocyanate polymer with... Significant New Uses for Specific Chemical Substances § 721.10608 Aliphatic diisocyanate polymer with.... (1) The chemical substance identified generically as aliphatic diisocyanate polymer with alkanediol...

  9. 40 CFR 721.10608 - Aliphatic diisocyanate polymer with alkanediol and alkylglycol (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Aliphatic diisocyanate polymer with... Significant New Uses for Specific Chemical Substances § 721.10608 Aliphatic diisocyanate polymer with.... (1) The chemical substance identified generically as aliphatic diisocyanate polymer with alkanediol...

  10. A comprehensive evaluation of the toxicology of cigarette ingredients: aliphatic and aromatic carboxylic acids.

    PubMed

    Coggins, Christopher R E; Liu, Jianmin; Merski, Jerome A; Werley, Michael S; Oldham, Michael J

    2011-06-01

    Aromatic and aliphatic carboxylic acids are present in tobacco and tobacco smoke. A battery of tests was used to compare the toxicity of mainstream smoke from experimental cigarettes containing eight aromatic and aliphatic carboxylic acids and the salt of one acid that were added individually at three different levels (lowest and highest target inclusions were 100 and 90,000 ppm, respectively). Mainstream smoke from cigarettes containing each of the test ingredients was evaluated using analytical chemistry and assays to measure in vitro cytotoxicity (neutral red uptake) and Salmonella (five strains) mutagenicity. For four of the compounds (citric, lactic, benzoic acids, and sodium benzoate), 90-day rodent inhalation studies were also performed. Although sporadic statistically significant differences in some experimental cigarette smoke constituents occurred, none resulted in significant changes in mutagenicity or cytotoxicity responses, nor in responses measured in the inhalation studies, except for lactic acid (LA). Inclusion of LA resulted in dose-dependent increase in water and caused a dose-dependent decrease in cytotoxicity. Incorporation of LA into cigarettes resulted in several dose-related reductions in histopathology, which were largely restricted to the nasal passages. Incorporation of LA also ameliorated some of the typical decrease in body weight gain seen in cigarette smoke-exposed rats. Inclusion of these ingredients at exaggerated use levels resulted in sporadic dose-related and treatment effects for some smoke constituents, but no toxicological response was noted in the in vitro and in vivo tests performed.

  11. New short aliphatic chain ionic liquids: synthesis, physical properties, and catalytic activity in aldol condensations.

    PubMed

    Cota, I; Gonzalez-Olmos, R; Iglesias, M; Medina, F

    2007-11-01

    This paper reports on the synthesis of new short aliphatic chain ionic liquids and the study of the temperature dependence of density, ultrasonic velocities, and ionic conductivity in the range of 278.15-338.15 K. Fourier transform infrared spectra establishes their simple ionic salt structure. Because of their polarity, the ionic liquids are able to dissolve polar solvents and inorganic salts, all of them showing high tolerance in hydroxylic media. The observed temperature trend of the studied properties points out the special packing of these ionic liquids, as well as the strong influence of the steric hindrance among linear aliphatic residues enclosed in anions and cations. One of them showed a very high melting temperature. A collection of slightly basic ionic liquids were used to test their catalytic activity in several aldol condensation reactions of some carbonyl compounds. The best conversions and selectivities were obtained using single ionic liquids, with no synergetic effects being observed when different concentrations of mixed ionic liquids were used as catalysts. In any case, the ionic liquid can also easily be recycled from reaction media, suggesting a promising method of process design for this kind of reaction.

  12. A role for coenzyme M (2-mercaptoethanesulfonic acid) in a bacterial pathway of aliphatic epoxide carboxylation

    PubMed Central

    Allen, Jeffrey R.; Clark, Daniel D.; Krum, Jonathan G.; Ensign, Scott A.

    1999-01-01

    The bacterial metabolism of short-chain aliphatic alkenes occurs via oxidation to epoxyalkanes followed by carboxylation to β-ketoacids. Epoxyalkane carboxylation requires four enzymes (components I–IV), NADPH, NAD+, and a previously unidentified nucleophilic thiol. In the present work, coenzyme M (2-mercaptoethanesulfonic acid), a compound previously found only in the methanogenic Archaea where it serves as a methyl group carrier and activator, has been identified as the thiol and central cofactor of aliphatic epoxide carboxylation in the Gram-negative bacterium Xanthobacter strain Py2. Component I catalyzed the addition of coenzyme M to epoxypropane to form a β-hydroxythioether, 2-(2-hydroxypropylthio)ethanesulfonate. Components III and IV catalyzed the NAD+-dependent stereoselective dehydrogenation of R- and S-enantiomers of 2-(2-hydroxypropylthio)ethanesulfonate to form 2-(2-ketopropylthio)ethanesulfonate. Component II catalyzed the NADPH-dependent cleavage and carboxylation of the β-ketothioether to form acetoacetate and coenzyme M. These findings evince a newfound versatility for coenzyme M as a carrier and activator of alkyl groups longer in chain-length than methane, a function for coenzyme M in a catabolic pathway of hydrocarbon oxidation, and the presence of coenzyme M in the bacterial domain of the phylogenetic tree. These results serve to unify bacterial and Archaeal metabolism further and showcase diverse biological functions for an elegantly simple organic molecule. PMID:10411892

  13. Trapping by amylose of the aliphatic chain grafted onto chlorogenic acid: importance of the graft position.

    PubMed

    Le-Bail, P; Lorentz, C; Pencreac'h, G; Soultani-Vigneron, S; Pontoire, B; López Giraldo, L J; Villeneuve, P; Hendrickx, J; Tran, V

    2015-03-06

    5-Caffeoylquinic acid (chlorogenic acid), is classified in acid-phenols family and as polyphenolic compounds it possesses antioxidant activity. The oxydative modification of chlorogenic acid in foods may lead to alteration of their qualities; to counteract these degradation effects, molecular encapsulation was used to protect chlorogenic acid. Amylose can interact strongly with a number of small molecules, including lipids. In order to enable chlorogenic acid complexation by amylose, a C16 aliphatic chain was previously grafted onto the cycle of quinic acid. This work showed that for the two lipophilic derivatives of chlorogenic acid: hexadecyl chlorogenate obtained by alkylation and 3-O-palmitoyl chlorogenic acid obtained by acylation; only the 3-O-palmitoyl chlorogenic acid complexed amylose. The chlorogenic acid derivatives were studied by X-ray diffraction, differential scanning calorimetry and NMR to elucidate the interaction. By comparing the results with previous work on the complexation of amylose by 4-O-palmitoyl chlorogenic acid, the importance of the aliphatic chain position on the cycle of the quinic acid is clearly highlighted. A study in molecular modeling helped to understand the difference in behavior relative to amylose of these three derivatives of chlorogenic acid. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Aliphatic and polycyclic aromatic hydrocarbons characterisation of Coimbra and Oporto PM2.5 urban aerosol

    NASA Astrophysics Data System (ADS)

    Rocha, A. C.; Mirante, F.; Gonçalves, C.; Nunes, T.; Alves, C.; Evtyugina, M.; Kowacz, M.; Pio, C.; Rocha, C.; Vasconcelos, T.

    2009-04-01

    The concentration of organic pollutants in urban areas is mostly due to incomplete combustion from vehicles, industries and domestic heating. Some of these compounds, principally the aliphatic (ALIPH) and polycyclic aromatic hydrocarbons (PAHs) promote harmful effects in human health. The determination of the ALIPH and PAHs concentration levels and their possible emission sources are useful for air quality management and source apportionment studies. In order to estimate and compare the ambient concentrations and establish the main sources of these compounds, the fine fraction of the atmospheric particulate matter (PM2.5) was collected simultaneously in Oporto and Coimbra during summer and winter seasons using a high volume sampler. The organic compounds were extracted from the particulate matter, under reflux with dichloromethane and the total organic extract (TOE) was fractionated by flash chromatography using five different eluents with increasing polarity. The hydrocarbon fractions were analysed by gas chromatography/mass spectrometry (GC/MS). Here we present and discuss the qualitative and quantitative composition of the aliphatic and aromatic fractions present in PM2.5 samples from both cities. The homologous series of C14 to C34 n-alkanes, isoprenoid hydrocarbons (pristane and phytane), PAHs and some petroleum markers have been identified and quantified. With the purpose of identifying the possible sources, various molecular diagnostic ratios were calculated. The global carbon preference index (CPI) closer to the unity, the large concentration of the unresolved complex mixture (UCM) and the presence of PAHs indicate that motor vehicle exhaust was the main emission source of the aliphatic and polycyclic aromatic fractions of Oporto and Coimbra aerosol, especially in the first city. Also, the remarkable presence of petroleum biomarkers such, as hopanes, confirms the previous results. Concentration ratios between PAHs were calculated and used to assign emission

  15. Neutron Scattering of Aromatic and Aliphatic Liquids

    PubMed Central

    Falkowska, Marta; Bowron, Daniel T.; Manyar, Haresh G.

    2016-01-01

    Abstract Organic solvents, such as cyclohexane, cyclohexene, methylcyclohexane, benzene and toluene, are widely used as both reagents and solvents in industrial processes. Despite the ubiquity of these liquids, the local structures that govern the chemical properties have not been studied extensively. Herein, we report neutron diffraction measurements on liquid cyclohexane, cyclohexene, methylcyclohexane, benzene and toluene at 298 K to obtain a detailed description of the local structure in these compounds. The radial distribution functions of the centres of the molecules, as well as the partial distribution functions for the double bond for cyclohexene and methyl group for methylcyclohexane and toluene have been calculated. Additionally, probability density functions and angular radial distribution functions were extracted to provide a full description of the local structure within the chosen liquids. Structural motifs are discussed and compared for all liquids, referring specifically to the functional group and aromaticity present in the different liquids. PMID:26990367

  16. Segregation and Alteration of Phenolic and Aliphatic Components of Root and Leaf Litter by Detritivores and Microbes

    NASA Astrophysics Data System (ADS)

    Filley, T. R.; Altmann, J.; Szlavecz, K. A.; Kalbitz, K.; Gamblin, D.; Nierop, K.

    2012-12-01

    The physical and microbial transformation of plant detritus in the litter layer and soil is accompanied by chemical separation of progressively soluble fractions and their movement into the rhizosphere driving subsequent soil processes. We investigated the combined action of specific detritivores, microbial decay, and leaching on the chemical separation of plant aromatic and aliphatic components from root, wood, and leaf tissue using 13C-TMAH thermochemolysis. This method enabled the simultaneous analysis of hydrolyzable tannin and lignin fragments, substituted fatty acids, and condensed tannin composition and revealed process-specific chemical transformations to plant secondary compounds. Long-term incubation and field sampling demonstrated how plant residues are progressively leached of the water soluble, oxidized fragments generated through decay. The residues appeared only slightly altered, in the case of brown rot wood, or enriched in aliphatic fragments, in the case of leaf and root tissue. Water extractable fractions were always selectively dominated by polyphenolics, either as demethylated lignin or tannins, and nearly devoid of aliphatic materials, despite high concentrations in the starting materials. Additionally, for plant materials with high tannin contents, such as pine needles, consumption and passage through some arthropod guts revealed what appeared to be microbially-mediated methylation of phenols, and a loss of tannins in leachates. These findings are indications for an in-situ phenol detoxification mechanism. This research provides important information regarding the links between biochemical decay and the chemical nature of organic matter removed and remaining in the soil profile.

  17. The Effect of Triton X-100 on Biodegradation of Aliphatic and Aromatic Fractions of Crude Oil in Soil

    NASA Astrophysics Data System (ADS)

    Minai-Tehrani, Dariush; Minooi, Saiid; Azari-Dehkordi, Forood; Herfatmanesh, Ali

    Crude oil is one the most common organic pollutant of the soil. The spillage of crude oil in the soil can be harmful to living organisms. Certain microorganisms are able to biodegrade crude oil and use it as sole carbon source. Some detergents were used to help the biodegradation of crude oil by microorganisms. In this study Triton X-100 was used to determine its effect in biodegradation of aliphatic and aromatic fractions of heavy crude oil in soil during 4 months. Different concentration of Triton X-100 (0 to 0.25%) was added to crude oil-contaminated soil with 2% (w/w) crude oil as final concentration. Present results demonstrated that in 0.025% of Triton X-100 the reduction of total crude oil, total aliphatic and total aromatic fractions were high, while in 0.05 to 0.25% the reduction reached to its minimum value. The higher reduction of phenanthrene, anthracene, fluoranthene and pyrene was observed in 0.025% Triton X-100 while it was lower in 0.25% followed by 0.1% Triton X-100. The low reduction of C17/pristane and C18/phytane in 0.25% Triton X-100 suggested low bioavaibility of aliphatic compounds in this concentration.

  18. Neutron Scattering of Aromatic and Aliphatic Liquids.

    PubMed

    Falkowska, Marta; Bowron, Daniel T; Manyar, Haresh G; Hardacre, Christopher; Youngs, Tristan G A

    2016-07-04

    Organic solvents, such as cyclohexane, cyclohexene, methylcyclohexane, benzene and toluene, are widely used as both reagents and solvents in industrial processes. Despite the ubiquity of these liquids, the local structures that govern the chemical properties have not been studied extensively. Herein, we report neutron diffraction measurements on liquid cyclohexane, cyclohexene, methylcyclohexane, benzene and toluene at 298 K to obtain a detailed description of the local structure in these compounds. The radial distribution functions of the centres of the molecules, as well as the partial distribution functions for the double bond for cyclohexene and methyl group for methylcyclohexane and toluene have been calculated. Additionally, probability density functions and angular radial distribution functions were extracted to provide a full description of the local structure within the chosen liquids. Structural motifs are discussed and compared for all liquids, referring specifically to the functional group and aromaticity present in the different liquids. ©2016 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  19. The effect of aliphatic olefins on the stability of diesel fuel

    SciTech Connect

    Adiwar; Batts, B.D.

    1995-04-01

    The effect of aliphatic olefins on the storage stability of a number of distillates was observed and characterized, mainly by determining the amounts of total insolubles formed during accelerated ageing. It was observed that the aliphatic olefins, in light cycle oil (LCO), a product of catalytic cracking, accelerated the degradation process in accordance with general expectations and in straight run diesel (SRD) and hydrotreated diesel (HTD), aliphatic olefins were shown to have no effect on stability. However, contrary to expectations, the aliphatic olefins inhibited the degradation process of light waxy gas oil (LWGO). The effect of aliphatic isomers on the degradation of LCO is in the order of terminal olefins < internal olefins < branched chain olefins. The effect of aliphatic olefinic isomers on LWGO is, on the other hand, in the order of terminal olefin > internal olefins > branched chain olefins. Three possible mechanisms to explain the effect of aliphatic olefins on the LCO and LWGO samples are proposed.

  20. {Polycyclic aromatic hydrocarbons (PAHs) and aliphatic hydrocarbons in gas and particle phases in two sites of Mexico: MILAGRO project}

    NASA Astrophysics Data System (ADS)

    Amador-Muñoz, O.; Villalobos-Pietrini, R.; Castro, T.; Gaspariano-Larino, R.

    2009-04-01

    Aliphatic hydrocarbons are markers of anthropogenic and biogenic emission sources1; meanwhile PAHs are generated by incomplete combustion sources2. The last ones are important compounds due to their carcinogenic and mutagenic properties3,4. The aim of this study was to identify and quantify aliphatic hydrocarbons and PAHs in gas and particles phases of the atmospheric aerosol and to determine the day and night time behavior during the MILAGRO (Megacity Initiative: Local Global and Research Observations) campaign. The gas phase was collected on polyurethane foam, while particles less than 2.5 m (PM2.5) were collected on glass fiber filters covered with Teflon (TIGF, pallflex) of 8x10 in. Samplings were carried out with a high volume sampler (Tisch) with a flow of 1.13 m3 min-1 at two sites: Instituto Mexicano del Petróleo (T0) and Tecamac (T1) located at North and Northeast of Mexico City, respectively during day (7:00 am-7:00 pm) and night time (7:00 pm-7:00 am) from 1 to 29 of March, 2006. Ninteen PAHs and 23 aliphatic hydrocarbons from n-C13H28 to n-C35H72 were analyzed by gas chromatography coupled to mass spectrometry in impact mode. The samples were spiked with deuterads PAHs and aliphatics hydrocarbons before ultrasound extraction. Medians comparisons were made with Mann-Whitney U test. PAHs with molecular weight (MW) less than 228 g mol-1 were distributed in the gas phase, in both sites. Higher concentrations of PAHs ≥ 228 g mol-1 in PM2.5, were observed during night period (p

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

    PubMed

    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.

  2. Synthesis of aliphatic sulfur pentafluorides by oxidation of SF₅-containing anisole, phenols, and anilines.

    PubMed

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

    2014-09-19

    4-(Pentafluorosulfanyl)catechol, 2-amino-4-(pentafluorosulfanyl)phenol, and 2-amino-5-(pentafluorosulfanyl)phenol undergo oxidation by lead tetraacetate at ambient temperature leading to dearomatization and the formation of SF5-substituted nitriles and esters of cis,cis-hexa-2,4-dienedioic (muconic) acid in good yields. 4-(Pentafluorosulfanyl)phenol and 4-(pentafluorosulfanyl)anisole are oxidized by 30% aqueous hydrogen peroxide in concentrated sulfuric acid to provide 2-(5-oxo-3-(pentafluorosulfanyl)-2,5-dihydrofuran-2-yl)acetic acid [3-(pentafluorosulfanyl)muconolactone] and small amounts of side products--SF5-containing maleic and succinic acids. The methods presented are the first examples of the practical synthesis of aliphatic SF5-containing compounds from readily available aromatic ones.

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

    PubMed Central

    Vida, Norbert; Václavík, Jiří

    2016-01-01

    Summary 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

  4. Oxidative aliphatic C-H fluorination with fluoride ion catalyzed by a manganese porphyrin.

    PubMed

    Liu, Wei; Huang, Xiongyi; Cheng, Mu-Jeng; Nielsen, Robert J; Goddard, William A; Groves, John T

    2012-09-14

    Despite the growing importance of fluorinated organic compounds in drug development, there are no direct protocols for the fluorination of aliphatic C-H bonds using conveniently handled fluoride salts. We have discovered that a manganese porphyrin complex catalyzes alkyl fluorination by fluoride ion under mild conditions in conjunction with stoichiometric oxidation by iodosylbenzene. Simple alkanes, terpenoids, and even steroids were selectively fluorinated at otherwise inaccessible sites in 50 to 60% yield. Decalin was fluorinated predominantly at the C2 and C3 methylene positions. Bornyl acetate was converted to exo-5-fluoro-bornyl acetate, and 5α-androstan-17-one was fluorinated selectively in the A ring. Mechanistic analysis suggests that the regioselectivity for C-H bond cleavage is directed by an oxomanganese(V) catalytic intermediate followed by F delivery via an unusual manganese(IV) fluoride that has been isolated and structurally characterized.

  5. Atmospheric chemistry of toxic contaminants 4. Saturated halogenated aliphatics: Methyl bromide, epichlorhydrin, phosgene

    SciTech Connect

    Grosjean, D. )

    1991-01-01

    Mechanisms are outlined for the reactions that contribute to in-situ formation and atmospheric removal of the saturated halogenated aliphatic contaminants methyl bromide, epichlorhydrin, and phosgene. In-situ formation is important only for phosgene and involves the reaction of OH with chloroethenes and other chlorinated hydrocarbons. A ranking of these phosgene precursors is given using data for precursor ambient concentrations and chemical reactivity. The three toxic compounds studied are long-lived in the atmosphere, where removal of phosgene and methyl bromide by chemical reactions is negligibly slow. Epichlorhydrin is removed slowly by reaction with OH, leading to formaldehyde, chloroacetaldehyde, and the chlorinated peroxyacyl nitrate CH{sub 2}ClC(O)OONO{sub 2}.

  6. Branched aliphatic alkanes with quaternary substituted carbon atoms in modern and ancient geologic samples.

    SciTech Connect

    Kenig, F.; Simons, D.-J. H.; Crich, D.; Cowen, J. P.; Ventura, G. T.; Rehbein-Khalily, T.; Brown, T. C.; Anderson, K. B.; Chemistry; Univ. of Illinois at Chicago; Univ. of Hawaii

    2003-01-01

    A pseudohomologous series of branched aliphatic alkanes with a quaternary substituted carbon atom (BAQCs, specifically 2,2-di-methylalkanes and 3,3- and 5,5-diethylalkanes) were identified in warm (65{sup o}C) deep-sea hydrothermal waters and Late Cretaceous black shales. 5,5-Diethylalkanes were also observed in modern and Holocene marine shelf sediments and in shales spanning the last 800 million years of the geological record. The carbon number distribution of BAQCs indicates a biological origin. These compounds were observed but not identified in previous studies of 2.0 billion- to 2.2 billion-year-old metasediments and were commonly misidentified in other sediment samples, indicating that BAQCs are widespread in the geological record. The source organisms of BAQCs are unknown, but their paleobiogeographic distribution suggests that they have an affinity for sulfides and might be nonphotosynthetic sulfide oxidizers.

  7. Oxidative aliphatic C-H fluorination with manganese catalysts and fluoride ion.

    PubMed

    Liu, Wei; Huang, Xiongyi; Groves, John T

    2013-12-01

    Fluorination is a reaction that is useful in improving the chemical stability and changing the binding affinity of biologically active compounds. The protocol described here can be used to replace aliphatic, C(sp(3))-H hydrogen in small molecules with fluorine. Notably, isolated methylene groups and unactivated benzylic sites are accessible. The method uses readily available manganese porphyrin and manganese salen catalysts and various fluoride ion reagents, including silver fluoride (AgF), tetrabutylammonium fluoride and triethylamine trihydrofluoride (TREAT·HF), as the source of fluorine. Typically, the reactions afford 50-70% yield of mono-fluorinated products in one step. Two representative examples, the fragrance component celestolide and the nonsteroidal anti-inflammatory drug ibuprofen, are described; they produced useful isolated quantities (250-300 mg, ~50% yield) of fluorinated material over periods of 1-8 h. The procedures are performed in a typical fume hood using ordinary laboratory glassware. No special precautions to rigorously exclude water are required.

  8. Aliphatics hydrocarbon content in surface sediment from Jakarta Bay, Indonesia

    NASA Astrophysics Data System (ADS)

    YAzis, M.; Asia, L.; Piram, A.; Doumenq, P.; Syakti, A. D.

    2016-02-01

    Sedimentary aliphatic hydrocarbons content have been studied quantitatively and qualitatively using GC/MS method in eight coastal stations located in the Jakarta Bay, North of Jakarta, Indonesia. The total concentrations n-alkanes have ranged from 480 μg.kg-1to 1,935 μg.kg-1sediment dry weight. Several ratios (e.g. CPI24-32, NAR, TAR, Pr/Phy, n-C17/Pr, n- C18/Phyt,n-C29/n-C17, Ʃn-alkanes/n-C16LMW/HMW, Paq and TMD) were used to evaluate the possible sources of terrestrial-marine inputs of these hydrocarbons in the sediments. The various origins of aliphatic hydrocarbons were generally biogenic, including both terrigenous and marine, with an anthropogenic pyrolytic contribution (petrogenic and biogenic combustion). Two stations (G,H) were thehighest concentration and had potential risk to environment

  9. Aliphatic dipeptide tags for multi-2-plex protein quantification.

    PubMed

    Suh, Min-Soo; Seo, Jongcheol; Thangadurai, T D; Rhee, Young Ho; Shin, Seung Koo; Yoon, Hye-Joo

    2011-04-21

    Mass-balanced (1)H/(2)H-isotope dipeptide tag (MBIT) is diversified as aliphatic tags for multiplexed protein quantification. Aliphatic MBITs are based on the N-acetyl-Xxx-Ala dipeptide, where Xxx is an artificial amino acid with a linear alkyl side chain from C(2)H(5) to C(8)H(17) (C(2)-C(8) tags). (1)H/(2)H isotopes are encoded in the methyl groups of N-acetyl and Ala to yield a pair of isobaric tags with 2-plex quantitation signals separated by 3 Da. C(2)-C(5) tags are prepared by solid-phase synthesis, while C(6)-C(8) tags are synthesized by olefin metathesis in solution. These aliphatic tags are made reactive toward the primary amines of peptides, and the relative abundances of quantitation signals are characterized using both matrix-assisted laser desorption ionization and electrospray ionization tandem mass spectrometry. MBIT-linked peptides co-migrate in reverse-phase liquid chromatography (LC), and their tandem mass spectra exhibit 2-plex quantitation signals as well as sequence ions in similar abundances. As the length of alkyl side chain increases, C(2)-C(8) tags show a stepwise increase in both the LC retention time and the relative abundance of quantitation signals. In addition, the quantitation linearity is well-maintained in a 15-250 fmol range. The multiplexing capability of aliphatic MBITs is demonstrated by applying three different tags (C(6)-C(8) tags) to the quantification of yeast heat shock proteins expressed under four different physiological conditions.

  10. Mechanics of networks of aliphatic fibers in aqueous surfactant media

    NASA Astrophysics Data System (ADS)

    Zanchetta, Giuliano; Caggioni, Marco; Guida, Vincenzo; Trappe, Veronique

    2012-02-01

    We investigate the structural and rheological properties of aliphatic fibers dispersed in aqueous solutions of anionic surfactants, typically used in liquid detergents to provide yield stress. This system displays an onset to solid-like properties that depends on fiber concentration. In this contribution we will discuss how tuning the state of the surfactant background influences the fiber-fiber interactions and the mechanical properties of the gel.

  11. Aerobic microorganism for the degradation of chlorinated aliphatic hydrocarbons

    DOEpatents

    Fliermans, Carl B.

    1989-01-01

    A chlorinated aliphatic hydrocarbon-degrading microorganism, having American Type Culture Collection accession numbers ATCC 53570 and 53571, in a biologically pure culture aseptically collected from a deep subsurface habitat and enhanced, mineralizes trichloroethylene and tetrachloroethylene to HCl, H.sub.2 O and Co.sub.2 under aerobic conditions stimulated by methane, acetate, methanol, tryptone-yeast extract, propane and propane-methane.

  12. Structure Property Relationship of Aliphatic Polyurethane Elastomers Prepared from CHDI

    DTIC Science & Technology

    1991-07-01

    transition around 60°C for polyurethanes which they felt was the result of poorly ordered hard segments. Studies of polybutadiene/ toluene diisocyanate ... diisocyan - atocyclohexane, poly(tetramethylene oxide), 1,4-butanediol and optionally trimethylolprop- ane. CHDI is a compact symmetrical diisocyanate ...the list of applications for these polymers. The new aliphatic diisocyanate which this study is based upon is trans-1,4-diisocyanatocyclohexane (CHDI

  13. Silver-mediated oxidative aliphatic C-H trifluoromethylthiolation.

    PubMed

    Guo, Shuo; Zhang, Xiaofei; Tang, Pingping

    2015-03-23

    The first example of a practical and direct trifluoromethylthiolation reaction of unactivated aliphatic CH bonds employs a silver-based reagent. The reaction is operationally simple, scalable, and proceeds under aqueous conditions in air. Furthermore, its broad scope and good functional-group compatibility were demonstrated by applying this method to the selective trifluoromethylthiolation of natural products and natural-product derivatives. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Manganese-Mediated Coupling Reaction of Vinylarenes and Aliphatic Alcohols

    PubMed Central

    Zhang, Wei; Wang, Nai-Xing; Bai, Cui-Bing; Wang, Yan-Jing; Lan, Xing-Wang; Xing, Yalan; Li, Yi-He; Wen, Jia-Long

    2015-01-01

    Alcohols and alkenes are the most abundant and commonly used organic building blocks in the large-scale chemical synthesis. Herein, this is the first time to report a novel and operationally simple coupling reaction of vinylarenes and aliphatic alcohols catalyzed by manganese in the presence of TBHP (tert-butyl hydroperoxide). This coupling reaction provides the oxyalkylated products of vinylarenes with good regioselectivity and accomplishes with the principles of step-economies. A possible reaction mechanism has also been proposed. PMID:26470633

  15. Aliphatic acetogenin constituents of avocado fruits inhibit human oral cancer cell proliferation by targeting the EGFR/RAS/RAF/MEK/ERK1/2 pathway

    SciTech Connect

    D'Ambrosio, Steven M.; Han, Chunhua; Pan, Li; Douglas Kinghorn, A.; Ding, Haiming

    2011-06-10

    Highlights: {yields} The aliphatic acetogenins [(2S,4S)-2,4-dihydroxyheptadec-16-enyl acetate] (1) and [(2S,4S)-2,4-dihydroxyheptadec-16-ynyl acetate] (2) isolated from avocado fruit inhibit phosphorylation of c-RAF (Ser338) and ERK1/2 (Thr202/Tyr204). {yields} Aliphatic acetogenin 2, but not 1, prevents EGF-induced activation of EGFR (Tyr1173). {yields} Combination of both aliphatic acetogenins synergistically inhibits c-RAF (Ser338) and ERK1/2 (Thr202/Tyr204) phosphorylation and human oral cancer cell proliferation. {yields} The potential anticancer activity of avocado fruits is due to a combination of specific aliphatic acetogenins targeting two key components of the EGFR/RAS/RAF/MEK/ERK1/2 cancer pathway. {yields} Providing a double hit on a critical cancer pathway such as EGFR/RAS/RAF/MEK/ERK1/2 by phytochemicals like those found in avocado fruit could lead to more effective approach toward cancer prevention. -- Abstract: Avocado (Persea americana) fruits are consumed as part of the human diet and extracts have shown growth inhibitory effects in various types of human cancer cells, although the effectiveness of individual components and their underlying mechanism are poorly understood. Using activity-guided fractionation of the flesh of avocado fruits, a chloroform-soluble extract (D003) was identified that exhibited high efficacy towards premalignant and malignant human oral cancer cell lines. From this extract, two aliphatic acetogenins of previously known structure were isolated, compounds 1 [(2S,4S)-2,4-dihydroxyheptadec-16-enyl acetate] and 2 [(2S,4S)-2,4-dihydroxyheptadec-16-ynyl acetate]. In this study, we show for the first time that the growth inhibitory efficacy of this chloroform extract is due to blocking the phosphorylation of EGFR (Tyr1173), c-RAF (Ser338), and ERK1/2 (Thr202/Tyr204) in the EGFR/RAS/RAF/MEK/ERK1/2 cancer pathway. Compounds 1 and 2 both inhibited phosphorylation of c-RAF (Ser338) and ERK1/2 (Thr202/Tyr204). Compound 2, but not

  16. Aromatics versus aliphatics: revealing the structure of carbonaceous dust.

    NASA Astrophysics Data System (ADS)

    Peeters, Els

    2015-10-01

    The mid-IR spectra of almost all objects are dominated by strong emission bands at 3.3, 6.2, 7.7, 8.6, and 11.3 micron due to Polycyclic Aromatic Hydrocarbon molecules (PAHs). It is now well established that these mid-IR bands show clear variations in shape and peak position from one point source to another, as well as varying spatially within extended sources. The spectral diversity of the PAH band profiles reveals the nature of the carriers and hence allows one to study their formation and evolution throughout their life cycle. Although the origin of the profile variations is still under debate, the observations point towards a varying importance of aliphatics versus aromatics in the carrier molecules. We propose to obtain FLITECAM observations of sources showing extreme red B or C profiles. Combined with previous results, the proposed observations are particularly suited to systematically investigate the connection between the PAH band profiles and the aliphatic emission bands at 3.4, 6.85 and 7.2 microns. These results will paint a necessary picture of the aromatic and aliphatic characteristics of the carbonaceous material and hence provide important clues on the origin of the PAH band profile variations.

  17. Biodegradation of aliphatic vs. aromatic hydrocarbons in fertilized arctic soils

    USGS Publications Warehouse

    Braddock, J.F.

    1999-01-01

    A study was carried out to test a simple bioremediation treatment strategy in the Arctic and analyze the influence of fertilization the degradation of aliphatic and aromatic hydrocarbons, e.g., pristine, n-tetradecane, n-pentadecane, 2-methylnaphthalene, naphthalene, and acenaphthalene. The site was a coarse sand pad that once supported fuel storage tanks. Diesel-range organics concentrations were 250-860 mg/kg soil at the beginning of the study. Replicate field plots treated with fertilizer yielded final concentrations of 0, 50, 100, or 200 mg N/kg soil. Soil pH and soil-water potentials decreased due to fertilizer application. The addition of fertilizer considerably increased soil respiration potentials, but not the populations of microorganisms measured. Fertilizer addition also led to ??? 50% loss of measured aliphatic and aromatic hydrocarbons in surface and subsurface soils. For fertilized plots, hydrocarbon loss was not associated with the quantity of fertilizer added. Losses of aliphatic hydrocarbons were ascribed to biotic processes, while losses of aromatic hydrocarbons were due to biotic and abiotic processes.

  18. Cost-Benefit Analysis for Alternatives to Aliphatic Isocyanate Polyurethanes

    NASA Technical Reports Server (NTRS)

    Lewis, Pattie

    2007-01-01

    NASA and Air Force Space Command (AFSPC) have similar missions and therefore similar facilities and structures in similar environments. The standard practice for protecting metallic substrates in atmospheric environments is the application of an applied coating system. The most common topcoats used in coating systems are polyurethanes that contain isocyanates. Isocyanates are classified as potential human carcinogens and are known to cause cancer in animals. The primary objective of this effort was to demonstrate and validate alternatives to aliphatic isocyanate polyurethanes resulting in one or more isocyanate-free coatings qualified for use at AFSPC and NASA installations participating in this project. This Cost-Benefit Analysis (CBA) quantifies the estimated capital and process costs of coating alternatives and cost savings relative to the current coatings. The estimates in this CBA are to be used for assessing the relative merits of the selected alternatives. The actual economic effects at any specific facility will depend on the alternative material or technology implemented, the number of actual applications converted, future workloads, and other factors . The participants initially considered eighteen (18) alternative coatings as described in the Potential Alternatives Report entitled Potential Alternatives Report for Validation of Alternatives to Aliphatic Isocyanate Polyurethanes, prepared by ITB. Of those, 8 alternatives were selected for testing in accordance with the Joint Test Protocol entitled Joint Test Protocol for Validation of Alternatives to Aliphatic Isocyanate Polyurethanes, and the Field Test Plan entitled Field Evaluations Test Plan for Validation of Alternatives 10 Aliphatic Isocyanate Polyurethanes, both of which were prepared by ITB. A joint Test Report entitled Joint Test Report for Validation of Alternatives to Aliphatic Isocyanate Polyurethanes, prepared by ITB, documents the results of the laboratory and field testing, as well as any

  19. A Quantitative Structure-Property Relationship (QSPR) Study of aliphatic alcohols by the method of dividing the molecular structure into substructure.

    PubMed

    Liu, Fengping; Cao, Chenzhong; Cheng, Bin

    2011-01-01

    A quantitative structure-property relationship (QSPR) analysis of aliphatic alcohols is presented. Four physicochemical properties were studied: boiling point (BP), n-octanol-water partition coefficient (lg P(OW)), water solubility (lg W) and the chromatographic retention indices (RI) on different polar stationary phases. In order to investigate the quantitative structure-property relationship of aliphatic alcohols, the molecular structure ROH is divided into two parts, R and OH to generate structural parameter. It was proposed that the property is affected by three main factors for aliphatic alcohols, alkyl group R, substituted group OH, and interaction between R and OH. On the basis of the polarizability effect index (PEI), previously developed by Cao, the novel molecular polarizability effect index (MPEI) combined with odd-even index (OEI), the sum eigenvalues of bond-connecting matrix (SX(1CH)) previously developed in our team, were used to predict the property of aliphatic alcohols. The sets of molecular descriptors were derived directly from the structure of the compounds based on graph theory. QSPR models were generated using only calculated descriptors and multiple linear regression techniques. These QSPR models showed high values of multiple correlation coefficient (R > 0.99) and Fisher-ratio statistics. The leave-one-out cross-validation demonstrated the final models to be statistically significant and reliable.

  20. Sulfur compounds in coal

    NASA Technical Reports Server (NTRS)

    Attar, A.; Corcoran, W. H.

    1977-01-01

    The literature on the chemical structure of the organic sulfur compounds (or functional groups) in coal is reviewed. Four methods were applied in the literature to study the sulfur compounds in coal: direct spectrometric and chemical analysis, depolymerization in drastic conditions, depolymerization in mild conditions, and studies on simulated coal. The data suggest that most of the organic sulfur in coal is in the form of thiophenic structures and aromatic and aliphatic sulfides. The relative abundance of the sulfur groups in bituminous coal is estimated as 50:30:20%, respectively. The ratio changes during processing and during the chemical analysis. The main effects are the transformation during processing of sulfides to the more stable thiophenic compounds and the elimination of hydrogen sulfide.

  1. Sulfur compounds in coal

    NASA Technical Reports Server (NTRS)

    Attar, A.; Corcoran, W. H.

    1977-01-01

    The literature on the chemical structure of the organic sulfur compounds (or functional groups) in coal is reviewed. Four methods were applied in the literature to study the sulfur compounds in coal: direct spectrometric and chemical analysis, depolymerization in drastic conditions, depolymerization in mild conditions, and studies on simulated coal. The data suggest that most of the organic sulfur in coal is in the form of thiophenic structures and aromatic and aliphatic sulfides. The relative abundance of the sulfur groups in bituminous coal is estimated as 50:30:20%, respectively. The ratio changes during processing and during the chemical analysis. The main effects are the transformation during processing of sulfides to the more stable thiophenic compounds and the elimination of hydrogen sulfide.

  2. Reductions of aliphatic and aromatic nitriles to primary amines with diisopropylaminoborane.

    PubMed

    Haddenham, Dustin; Pasumansky, Lubov; DeSoto, Jamie; Eagon, Scott; Singaram, Bakthan

    2009-03-06

    pointed out that lithium aminoborohydrides (LABs) do not reduce nitriles under ambient conditions and behave as bases with aliphatic nitriles as well as nitriles containing acidic alpha-protons. Consequently, both LABs and BH(2)N(iPr)(2) are complementary to each other and offer methods for the selective reductions of multifunctional compounds.

  3. Aluminum-Catalyzed Cross-Coupling of Silylalkynes with Aliphatic C-F Bonds.

    PubMed

    Jaiswal, Amit K; Goh, Kelvin K K; Sung, Simon; Young, Rowan D

    2017-04-07

    We report the generation of aliphatic and benzylic acetylenes via reaction of primary, secondary, and tertiary aliphatic fluorides with various trimethylsilyl acetylides. These reactions are catalyzed by Al and B Lewis acids, most effectively by the extremely fluorophilic tris(pentafluorophenyl)alane, representing the first example of catalytic incorporation of alkynes into aliphatic C-F positions. The fluorophilicity of the catalysts gives rise to fluorine selectivity over other halogens, allowing orthogonal reactivity pathways.

  4. Seasonal variation of aliphatic amines in marine sub-micrometer particles at the Cape Verde islands

    NASA Astrophysics Data System (ADS)

    Müller, C.; Iinuma, Y.; Karstensen, J.; van Pinxteren, D.; Lehmann, S.; Gnauk, T.; Herrmann, H.

    2009-07-01

    Monomethylamine (MA), dimethylamine (DMA) and diethylamine (DEA) were detected at non-negligible concentrations in sub-micrometer particles at the Cap Verde Atmospheric Observatory (CVAO) located on the island of São Vicente in Cape Verde during algal blooms in 2007. The concentrations of these amines in five stage impactor samples ranged from 0 to 30 pg m-3 for MA, 130 to 360 pg m-3 for DMA and 5 to 110 pg m-3 for DEA during the spring bloom in May 2007 and 2 to 520 pg m-3 for MA, 100 to 1400 pg m-3 for DMA, 90 to 760 pg m-3 for DEA during an unexpected winter algal bloom in December 2007. Anomalously high Saharan dust deposition and intensive ocean layer deepening were found at the Atmospheric Observatory and the associated Ocean Observatory during algal bloom periods. The highest amine concentrations in fine particles (impactor stage 2, 0.14-0.42 μm) indicates that amines are likely taken up from the gas phase into the acidic sub-micrometer particles. The contribution of amines to the organic carbon (OC) content ranged from 0.2 to 2.5%C in the winter months, indicating the importance of this class of compounds to the carbon cycle in the marine environment. Furthermore, aliphatic amines originating from marine biological sources likely contribute significantly to the organic nitrogen in the marine atmosphere. The average contribution of the amines to the total detected nitrogen content in submicron particles can be non-negligible, especially in the winter months (0.1% N to 1.5% N in the sum of nitrate, ammonium and amines). This indicates that these smaller aliphatic amines can be important for the carbon and the nitrogen cycles in the remote marine environment.

  5. Seasonal variation of aliphatic amines in marine sub-micrometer particles at the Cape Verde islands

    NASA Astrophysics Data System (ADS)

    Müller, C.; Iinuma, Y.; Karstensen, J.; van Pinxteren, D.; Lehmann, S.; Gnauk, T.; Herrmann, H.

    2009-12-01

    Monomethylamine (MA), dimethylamine (DMA) and diethylamine (DEA) were detected at non-negligible concentrations in sub-micrometer particles at the Cap Verde Atmospheric Observatory (CVAO) located on the island of São Vicente in Cape Verde during algal blooms in 2007. The concentrations of these amines in five stage impactor samples ranged from 0-30 pg m-3 for MA, 130-360 pg m-3 for DMA and 5-110 pg m-3 for DEA during the spring bloom in May 2007 and 2-520 pg m-3 for MA, 100-1400 pg m-3 for DMA and 90-760 pg m-3 for DEA during an unexpected winter algal bloom in December 2007. Anomalously high Saharan dust deposition and intensive ocean layer deepening were found at the Atmospheric Observatory and the associated Ocean Observatory during algal bloom periods. The highest amine concentrations in fine particles (impactor stage 2, 0.14-0.42 μm) indicate that amines are likely taken up from the gas phase into the acidic sub-micrometer particles. The contribution of amines to the organic carbon (OC) content ranged from 0.2-2.5% C in the winter months, indicating the importance of this class of compounds to the carbon cycle in the marine environment. Furthermore, aliphatic amines originating from marine biological sources likely contribute significantly to the nitrogen content in the marine atmosphere. The average contribution of the amines to the detected nitrogen species in sub-micrometer particles can be non-negligible, especially in the winter months (0.1% N-1.5% N in the sum of nitrate, ammonium and amines). This indicates that these smaller aliphatic amines can be important for the carbon and the nitrogen cycles in the remote marine environment.

  6. Decarboxylative Fluorination of Aliphatic Carboxylic Acids via Photoredox Catalysis

    PubMed Central

    Ventre, Sandrine; Petronijevic, Filip R.; MacMillan, David W. C.

    2016-01-01

    The direct conversion of aliphatic carboxylic acids to the corresponding alkyl fluorides has been achieved via visible light-promoted photoredox catalysis. This operationally simple, redox-neutral fluorination method is amenable to a wide variety of carboxylic acids. Photon-induced oxidation of carboxylates leads to the formation of carboxyl radicals, which upon rapid CO2-extrusion and F• transfer from a fluorinating reagent yield the desired fluoroalkanes with high efficiency. Experimental evidence indicates that an oxidative quenching pathway is operable in this broadly applicable fluorination protocol. PMID:25881929

  7. Structural studies of aliphatic substituted phthalocyanine-lipid multilayers.

    PubMed

    Zarbakhsh, Ali; Campana, Mario; Mills, David; Webster, John R P

    2010-10-05

    A Langmuir-Blodgett film of aliphatic substituted phthalocyanines on a C18 silane supporting layer coupled onto a silicon substrate has been investigated using neutron reflectometry. This multilayer structure is seen as a possible candidate for phthalocyanine-lipid biosensor devices. The results show the suitability of the C18 ligands as an anchoring layer for the phthalocyanines. The scattering length density profiles demonstrate the effectiveness of a lipid monolayer in partitioning the composition of phthalocyanine layers from that of the bulk liquid. The effectiveness of this barrier is a critical factor in the efficiency of such devices.

  8. Arsenolipids in oil from blue whiting Micromesistius poutassou – evidence for arsenic-containing esters

    PubMed Central

    Taleshi, Mojtaba S.; Raber, Georg; Edmonds, John S.; Jensen, Kenneth B.; Francesconi, Kevin A.

    2014-01-01

    Arsenic-containing lipids in the oil from the blue whiting fish (Micromesistius poutassou) were separated into three broad polarity groups and investigated by HPLC and mass spectrometry. A total of 11 arsenolipids including 4 new compounds were identified. The polar lipid fraction constituting 24% of the total arsenolipid content (which totalled 2.16 μg As/g) contained four known dimethylarsinoyl fatty acids and three known dimethylarsinoyl hydrocarbons. The less polar fraction (ca 30% of the total arsenolipids) contained four new dimethylarsinoyl hydrocarbons with chain lengths 22–30 carbons, in addition to more complex arsenicals that hydrolysed to known dimethylarsinoyl fatty acids suggesting they were conjugated carboxylic acids, presumably esters. The rest of the lipid-soluble arsenic (ca 45% of the total) remained in the non-polar fraction together with the bulk of the fish oil lipids, a complex mixture of compounds that precluded identification of the small amounts of arsenolipids. PMID:25502848

  9. Arsenolipids in oil from blue whiting Micromesistius poutassou - evidence for arsenic-containing esters

    NASA Astrophysics Data System (ADS)

    Taleshi, Mojtaba S.; Raber, Georg; Edmonds, John S.; Jensen, Kenneth B.; Francesconi, Kevin A.

    2014-12-01

    Arsenic-containing lipids in the oil from the blue whiting fish (Micromesistius poutassou) were separated into three broad polarity groups and investigated by HPLC and mass spectrometry. A total of 11 arsenolipids including 4 new compounds were identified. The polar lipid fraction constituting 24% of the total arsenolipid content (which totalled 2.16 μg As/g) contained four known dimethylarsinoyl fatty acids and three known dimethylarsinoyl hydrocarbons. The less polar fraction (ca 30% of the total arsenolipids) contained four new dimethylarsinoyl hydrocarbons with chain lengths 22-30 carbons, in addition to more complex arsenicals that hydrolysed to known dimethylarsinoyl fatty acids suggesting they were conjugated carboxylic acids, presumably esters. The rest of the lipid-soluble arsenic (ca 45% of the total) remained in the non-polar fraction together with the bulk of the fish oil lipids, a complex mixture of compounds that precluded identification of the small amounts of arsenolipids.

  10. Short-chain aliphatic ester synthesis using Thermobifida fusca cutinase.

    PubMed

    Su, Lingqia; Hong, Ruoyu; Guo, Xiaojie; Wu, Jing; Xia, Yongmei

    2016-09-01

    Short-chain aliphatic esters are commonly used as fruit flavorings in the food industry. In this study, Thermobifida fusca (T. fusca) cutinase was used for the synthesis of aliphatic esters, and the maximum yield of ethyl caproate reached 99.2% at a cutinase concentration of 50U/ml, 40°C, and water content of 0.5%, representing the highest ester yield to date. The cutinase-catalyzed esterification displayed strong tolerance for water content (up to 8%) and acid concentration (up to 0.8M). At substrate concentrations ⩽0.8M, the ester yield remained above 80%. Moreover, ester yields of more than 98% and 95% were achieved for acids of C3-C8 and alcohols of C1-C6, respectively, indicating extensive chain length selectivity of the cutinase. These results demonstrate the superior ability of T. fusca cutinase to catalyze the synthesis of short-chain esters. This study provides the basis for industrial production of short-chain esters using T. fusca cutinase.

  11. Atmospheric chemistry of toxic contaminants. 5. Unsaturated halogenated aliphatics: Allyl chloride, chloroprene, hexachlorocyclopentadiene, vinylidene chloride

    SciTech Connect

    Grosjean, D. )

    1991-02-01

    Detailed mechanisms are outlined for the chemical reactions involved in the atmospheric removal of four unsaturated chlorinated aliphatic contaminants, allyl chloride, chloroprene, hexachlorocyclopentadiene and vinylidene chloride. Rate constants estimated from structure-reactivity relationships indicate rapid removal for all four compounds by reactions with OH (major), ozone, and No{sub 3}, with half-lives of 2-16 hrs for removal by reaction with OH. Reaction products of allyl chloride (formaldehyde, chloroacetaldehyde, peroxychloroacetyl nitrate) and vinylidene chloride (formaldehyde, phosgene, chloroacetyl chloride) are consistent with OH addition-initiated pathways that include Cl atom elimination. The chlorine atoms produced in the OH reaction sequence react rapidly with all four unsaturated compounds, but these reactions are of negligible importance for atmospheric removal of the four toxic contaminants studied. Analogous mechanisms are discussed for chloroprene (leading to formaldehyde, CH{sub 2} {double bond} CClCHO, and ClCOCHO) and for hexachlorocyclopentadiene (leading to oxalyl chloride and ClCOCCl{sub 2}COCl).

  12. Aliphatic Hydrocarbon Enhances Phenanthrene Degradation by Autochthonous Prokaryotic Communities from a Pristine Seawater.

    PubMed

    Rodrigues, Edmo Montes; Morais, Daniel Kumazawa; Pylro, Victor Satler; Redmile-Gordon, Marc; de Oliveira, Juraci Alves; Roesch, Luiz Fernando Wurdig; Cesar, Dionéia Evangelista; Tótola, Marcos Rogério

    2017-10-03

    The microbial diversity and functioning around oceanic islands is poorly described, despite its importance for ecosystem homeostasis. Here, we aimed to verify the occurrence of microbe-driven phenanthrene co-oxidation in the seawater surrounding the Trindade Island (Brazil). We also used Next-Generation Sequencing to evaluate the effects of aliphatic and polycyclic aromatic hydrocarbons (PAHs) on these microbial community assemblies. Microcosms containing seawater from the island enriched with either labelled (9-(14)C) or non-labelled phenanthrene together with hexadecane, weathered oil, fluoranthene or pyrene, and combinations of these compounds were incubated. Biodegradation of phenanthrene-9-(14)C was negatively affected in the presence of weathered oil and PAHs but increased in the presence of hexadecane. PAH contamination caused shifts in the seawater microbial community-from a highly diverse one dominated by Alphaproteobacteria to less diverse communities dominated by Gammaproteobacteria. Furthermore, the combination of PAHs exerted a compounded negative influence on the microbial community, reducing its diversity and thus functional capacity of the ecosystem. These results advance our understanding of bacterial community dynamics in response to contrasting qualities of hydrocarbon contamination. This understanding is fundamental in the application and monitoring of bioremediation strategies if accidents involving oil spillages occur near Trindade Island and similar ecosystems.

  13. Assimilation of Unusual Carbon Compounds

    NASA Astrophysics Data System (ADS)

    Middelhoven, Wouter J.

    Yeast taxa traditionally are distinguished by growth tests on several sugars and organic acids. During the last decades it became apparent that many yeast species assimilate a much greater variety of naturally occurring carbon compounds as sole source of carbon and energy. These abilities are indicative of a greater role of yeasts in the carbon cycle than previously assumed. Especially in acidic soils and other habitats, yeasts may play a role in the degradation of carbon compounds. Such compounds include purines like uric acid and adenine, aliphatic amines, diamines and hydroxyamines, phenolics and other benzene compounds and polysaccharides. Assimilation of purines and amines is a feature of many ascomycetes and basidiomycetes. However, benzene compounds are degraded by only a few ascomycetous yeasts (e.g. the Stephanoascus/ Blastobotrys clade and black yeastlike fungi) but by many basidiomycetes, e.g. Filobasidiales, Trichosporonales, red yeasts producing ballistoconidia and related species, but not by Tremellales. Assimilation of polysaccharides is wide-spread among basidiomycetes

  14. Mechanisms of inhibition of CaV3.1 T-type calcium current by aliphatic alcohols

    PubMed Central

    Eckle, Veit-Simon; Todorovic, Slobodan M

    2010-01-01

    Many aliphatic alcohols modulate activity of various ion channels involved in sensory processing and also exhibit anesthetic capacity in vivo. Although the interaction of one such compound, 1-octanol (octanol) with different T-type calcium channels (T-channels) has been described, the mechanisms of current modulation and its functional significance are not well studied. Using patch-clamp technique, we investigated the mechanisms of inhibition of T-currents by a series of aliphatic alcohols in recombinant human CaV3.1 (α1G) T-channel isoform expressed in human embryonic kidney (HEK) 293 cells and thalamocortical (TC) relay neurons in brain slices of young rats. Octanol, 1-heptanol (heptanol) and 1-hexanol (hexanol) inhibited the recombinant CaV3.1 currents in concentration-dependent manner yielding IC50 values of 362 µM, 1063 µM and 3167 µM, respectively. Octanol similarly inhibited native thalamic CaV3.1 T-currents with an IC50 of 287 µM and diminished burst firing without significant effect on passive membrane properties of these neurons. Inhibitory effect of octanol on T-currents in both native and recombinant cells was accompanied with accelerated macroscopic inactivation kinetics and hyperpolarizing shift in the steady-state inactivation curve. Additionally, octanol induced a depolarizing shift in steady-state activation curves of T-current in TC neurons. Surprisingly, the recovery from fast inactivation at hyperpolarized membrane potentials was accelerated by octanol up three-fold in native but not recombinant channels. Given the importance of thalamocortical pathways in providing sleep, arousal, and anesthetic states, modulation of thalamic T-currents may at least contribute to the pharmacological effects of aliphatic alcohols. PMID:20363234

  15. The Size of the Unbranched Aliphatic Chain Determines the Immunomodulatory Potency of Short and Long Chain n-Alkanols*

    PubMed Central

    Carignan, Damien; Désy, Olivier; Ghani, Karim; Caruso, Manuel; de Campos-Lima, Pedro O.

    2013-01-01

    Aliphatic n-alkanols are a family of ubiquitous substances that display general anesthetic properties in accordance to their degree of hydrophobicity. In addition, the immunomodulatory activity of one of its members, ethanol, has long been recognized. We reasoned that because unbranched aliphatic n-alkanols are structurally very similar they might have an immunological impact that mirrors their anesthetic potency. We report the impact of the homologous C1–C12 alcohol series on the ability of activated primary human lymphocytes to produce IFN-γ. Methanol enhanced IFN-γ production whereas C2–C10 alcohols reduced the release of this cytokine. The activity of the n-alkanol series was observed within a wide concentration window ranging from millimolar levels for short chain alcohols to micromolar amounts for C7–C10 alcohols. There was a clear correlation between immunomodulatory activity and hydrophobicity of the compounds, but a cutoff effect was evident at C11. n-Alkanols were shown to act downstream of the cell membrane because T cell receptor early signaling was preserved. The activation of the nuclear factor of activated T cells (NFAT) was down-regulated progressively in accordance to the size of the n-alkanol aliphatic chains with a clear downward trend that was interrupted at C11. The nuclear factor-κB (NF-κB) signaling was also compromised, but the cutoff appeared earlier at C10. The pattern of immunomodulation and transcriptional dysregulation induced by the n-alkanol series suggested the existence of interaction pockets of defined dimensions within intracellular targets that compromise the activation of NFAT and NF-κB transcription factors and ultimately modulate the effector function of the T lymphocyte. PMID:23839943

  16. 40 CFR 721.7250 - Polyaziridinyl ester of an aliphatic alcohol (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... alcohol (generic). 721.7250 Section 721.7250 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.7250 Polyaziridinyl ester of an aliphatic alcohol (generic). (a... generically as a polyaziridinyl ester of an aliphatic alcohol (PMN P-01-97) is subject to reporting under...

  17. 40 CFR 721.7250 - Polyaziridinyl ester of an aliphatic alcohol (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... alcohol (generic). 721.7250 Section 721.7250 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.7250 Polyaziridinyl ester of an aliphatic alcohol (generic). (a... generically as a polyaziridinyl ester of an aliphatic alcohol (PMN P-01-97) is subject to reporting under...

  18. 40 CFR 721.7250 - Polyaziridinyl ester of an aliphatic alcohol (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... alcohol (generic). 721.7250 Section 721.7250 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.7250 Polyaziridinyl ester of an aliphatic alcohol (generic). (a... generically as a polyaziridinyl ester of an aliphatic alcohol (PMN P-01-97) is subject to reporting under...

  19. 40 CFR 721.10605 - Polyoxyalkylene ether, polymer with aliphatic diisocyanate, homopolymer, alkanol-blocked (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Polyoxyalkylene ether, polymer with..., polymer with aliphatic diisocyanate, homopolymer, alkanol-blocked (generic). (a) Chemical substance and... polyoxyalkylene ether, polymer with aliphatic diisocyanate, homopolymer, alkanol-blocked (PMN P-11-485) is subject...

  20. 40 CFR 721.10605 - Polyoxyalkylene ether, polymer with aliphatic diisocyanate, homopolymer, alkanol-blocked (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Polyoxyalkylene ether, polymer with..., polymer with aliphatic diisocyanate, homopolymer, alkanol-blocked (generic). (a) Chemical substance and... polyoxyalkylene ether, polymer with aliphatic diisocyanate, homopolymer, alkanol-blocked (PMN P-11-485) is subject...

  1. 40 CFR 721.10606 - Alkyl substituted alkanediol polymer with aliphatic and alicyclic diisocyanates (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alkyl substituted alkanediol polymer... alkanediol polymer with aliphatic and alicyclic diisocyanates (generic). (a) Chemical substance and... substituted alkanediol polymer with aliphatic and alicyclic diisocyanates (PMN P-11-486) is subject to...

  2. 40 CFR 721.10606 - Alkyl substituted alkanediol polymer with aliphatic and alicyclic diisocyanates (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkyl substituted alkanediol polymer... alkanediol polymer with aliphatic and alicyclic diisocyanates (generic). (a) Chemical substance and... substituted alkanediol polymer with aliphatic and alicyclic diisocyanates (PMN P-11-486) is subject to...

  3. A statistical approach to the interpretation of aliphatic hydrocarbon distributions in marine sediments

    USGS Publications Warehouse

    Rapp, J.B.

    1991-01-01

    Q-mode factor analysis was used to quantitate the distribution of the major aliphatic hydrocarbon (n-alkanes, pristane, phytane) systems in sediments from a variety of marine environments. The compositions of the pure end members of the systems were obtained from factor scores and the distribution of the systems within each sample was obtained from factor loadings. All the data, from the diverse environments sampled (estuarine (San Francisco Bay), fresh-water (San Francisco Peninsula), polar-marine (Antarctica) and geothermal-marine (Gorda Ridge) sediments), were reduced to three major systems: a terrestrial system (mostly high molecular weight aliphatics with odd-numbered-carbon predominance), a mature system (mostly low molecular weight aliphatics without predominance) and a system containing mostly high molecular weight aliphatics with even-numbered-carbon predominance. With this statistical approach, it is possible to assign the percentage contribution from various sources to the observed distribution of aliphatic hydrocarbons in each sediment sample. ?? 1991.

  4. Photopatternable Biodegradable Aliphatic Polyester with Pendent Benzophenone Groups.

    PubMed

    Chen, Dayong; Chang, Chia-Chih; Cooper, Beth; Silvers, Angela; Emrick, Todd; Hayward, Ryan C

    2015-10-12

    Highly efficient photo-cross-linking reactions enable numerous applications in biomaterials. Here, a photopatternable biodegradable aliphatic polyester with benzophenone pendent groups was synthesized by copper-catalyzed alkyne-azide cycloaddition, affording polyesters that undergo UV-induced cross-linking to yield photopatterned films. Using this material, a self-folding multilayer structure containing polyester/hydrogel bilayer hinges was fabricated. Upon swelling of the hydrogel layer, the construct folds into a triangular tube, which subsequently unfolds due to lipase-catalyzed degradation of the polyester layer. The ability to precisely design such degradation-induced structural changes offers potential for biomaterials and medical applications, such as evolving and responsive 2D and 3D tissue engineering scaffolds.

  5. Aqueous infrared carboxylate absorbances: Aliphatic di-acids

    USGS Publications Warehouse

    Cabaniss, S.E.; Leenheer, J.A.; McVey, I.F.

    1998-01-01

    Aqueous attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectra of 18 aliphatic di-carboxylic acids are reported as a function of pH. The spectra show isosbestic points and intensity changes which indicate that Beer's law is obeyed, and peak frequencies lie within previously reported ranges for aqueous carboxylates and pure carboxylic acids. Intensity sharing from the symmetric carboxylate stretch is evident in many cases, so that bands which are nominally due to alkyl groups show increased intensity at higher pH. The asymmetric stretch of the HA- species is linearly related to the microscopic acidity constant of the H2A species, with ??pK 2 intervening atoms). The results suggest that aqueous ATR-FTIR may be able to estimate 'intrinsic' pKa values of carboxylic acids, in addition to providing quantitative estimates of ionization. ?? 1998 Elsevier Science B.V. All rights reserved.

  6. Surface Characterization of Aliphatic Polyester -g- Phosphorylcholine Copolymers

    NASA Astrophysics Data System (ADS)

    Zhang, Xiongfei; Emrick, Todd; Hsu, Shaw L.

    2007-03-01

    In order to control biodegradation behavior of a class of polyesters, hydrophilic functional groups were grafted onto the main chains. Phosphorylcholine (PC) molecules with azide attached at the end were synthesized. Due to their excellent biocompatibility and hydrophilicity, they have been covalently coupled to biodegradable aliphatic polyesters via a ``click'' cycloaddition reaction to produce amphiphilic graft copolymers. A series of copolymers were prepared by varying the molar incorporation of PC groups. Surface properties of the copolymers were examined to further explore their applications in drug delivery systems. Grazing angle reflection infrared spectroscopy was employed to determine segmental orientation at the film surface. XPS was used to verify surface composition. A water adsorption experiment was carried out to determine the water permeation rate. The improvement in hydrophilicity was confirmed by a water contact experiment. Results indicate that the graft copolymers were promising in drug delivery systems.

  7. A bio-catalytic approach to aliphatic ketones.

    PubMed

    Xiong, Mingyong; Deng, Jin; Woodruff, Adam P; Zhu, Minshan; Zhou, Jun; Park, Sun Wook; Li, Hui; Fu, Yao; Zhang, Kechun

    2012-01-01

    Depleting oil reserves and growing environmental concerns have necessitated the development of sustainable processes to fuels and chemicals. Here we have developed a general metabolic platform in E. coli to biosynthesize carboxylic acids. By engineering selectivity of 2-ketoacid decarboxylases and screening for promiscuous aldehyde dehydrogenases, synthetic pathways were constructed to produce both C5 and C6 acids. In particular, the production of isovaleric acid reached 32 g/L (0.22 g/g glucose yield), which is 58% of the theoretical yield. Furthermore, we have developed solid base catalysts to efficiently ketonize the bio-derived carboxylic acids such as isovaleric acid and isocaproic acid into high volume industrial ketones: methyl isobutyl ketone (MIBK, yield 84%), diisobutyl ketone (DIBK, yield 66%) and methyl isoamyl ketone (MIAK, yield 81%). This hybrid "Bio-Catalytic conversion" approach provides a general strategy to manufacture aliphatic ketones, and represents an alternate route to expanding the repertoire of renewable chemicals.

  8. A Bio-Catalytic Approach to Aliphatic Ketones

    PubMed Central

    Xiong, Mingyong; Deng, Jin; Woodruff, Adam P.; Zhu, Minshan; Zhou, Jun; Park, Sun Wook; Li, Hui; Fu, Yao; Zhang, Kechun

    2012-01-01

    Depleting oil reserves and growing environmental concerns have necessitated the development of sustainable processes to fuels and chemicals. Here we have developed a general metabolic platform in E. coli to biosynthesize carboxylic acids. By engineering selectivity of 2-ketoacid decarboxylases and screening for promiscuous aldehyde dehydrogenases, synthetic pathways were constructed to produce both C5 and C6 acids. In particular, the production of isovaleric acid reached 32 g/L (0.22 g/g glucose yield), which is 58% of the theoretical yield. Furthermore, we have developed solid base catalysts to efficiently ketonize the bio-derived carboxylic acids such as isovaleric acid and isocaproic acid into high volume industrial ketones: methyl isobutyl ketone (MIBK, yield 84%), diisobutyl ketone (DIBK, yield 66%) and methyl isoamyl ketone (MIAK, yield 81%). This hybrid “Bio-Catalytic conversion” approach provides a general strategy to manufacture aliphatic ketones, and represents an alternate route to expanding the repertoire of renewable chemicals. PMID:22416247

  9. Aliphatic Polyethers: Classical Polymers for the 21st Century.

    PubMed

    Klein, Rebecca; Wurm, Frederik R

    2015-06-01

    Polyethers-polymers with the structural element (R'-O-R)n in their backbone--are an old class of polymers which were already used at the time of the ancient Egyptians. However, still today these materials are highly important with applications in all areas of our life, reaching from the automotive and paper industry to cosmetics and biomedical applications. In this Review, different aliphatic polyethers like poly(epoxide)s, poly(oxetane)s, and poly(tetrahydrofuran) are discussed. Special emphasis is placed on the history, the polymerization techniques (industrially and in academia), the properties, the applications as well as recent developments of these materials. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Identification and biotransformation of aliphatic hydrocarbons during co-composting of sewage sludge-Date Palm waste using Pyrolysis-GC/MS technique.

    PubMed

    El Fels, Loubna; Lemee, Laurent; Ambles, André; Hafidi, Mohamed

    2016-08-01

    The behavior of aliphatic hydrocarbons during co-composting of sewage sludge activated with palm tree waste was studied for 6 months using Py-GC/MS. The main aliphatic compounds represented as doublet alkenes/alkanes can be classified into three groups. The first group consists of 11 alkenes (undecene, tridecene, pentadecene, hexadecene, heptadecene, octadecene, nonadecene, eicosene, uncosene, docosene, tricosene) and 15 alkanes (heptane, octane, nonane, decane, undecane, dodecane, tetradecane, pentadecane, heptadecane, octadecane, nonadecane, eicosane, uncosane, docosane, and tricosane), which remain stable during the co-composting process. The stability of these compounds is related to their recalcitrance behavior. The second group consists of five alkenes (heptene, octene, nonene, decene, dodecene) and tridecane as a single alkane that decreases during co-composting. The decrease in these compounds is the combined result of their metabolism and their conversion into other compounds. The third group is constituted with tetradecene and hexadecane that increase during composting, which could be explained by accumulation of these compounds, which are released by the partial breakdown of the substrate. As a result, these molecules are incorporated or adsorbed in the structure of humic substances.

  11. 40 CFR 721.10190 - Formaldehyde, polymer with aliphatic diamine and phenol, reaction products with 4-methyl-2...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Formaldehyde, polymer with aliphatic... Formaldehyde, polymer with aliphatic diamine and phenol, reaction products with 4-methyl-2-pentanone (generic... identified generically as formaldehyde, polymer with aliphatic diamine and phenol, reaction products with...

  12. 40 CFR 721.10190 - Formaldehyde, polymer with aliphatic diamine and phenol, reaction products with 4-methyl-2...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Formaldehyde, polymer with aliphatic... Formaldehyde, polymer with aliphatic diamine and phenol, reaction products with 4-methyl-2-pentanone (generic... identified generically as formaldehyde, polymer with aliphatic diamine and phenol, reaction products with...

  13. Quantitative structure-activity relationship (QSAR) prediction of (eco)toxicity of short aliphatic protic ionic liquids.

    PubMed

    Peric, Brezana; Sierra, Jordi; Martí, Esther; Cruañas, Robert; Garau, Maria Antonia

    2015-05-01

    Ionic liquids (ILs) are considered as a group of very promising compounds due to their excellent properties (practical non-volatility, high thermal stability and very good and diverse solving capacity). The ILs have a good prospect of replacing traditional organic solvents in vast variety of applications. However, the complete information on their environmental impact is still not available. There is also an enormous number of possible combinations of anions and cations which can form ILs, the fact that requires a method allowing the prediction of toxicity of existing and potential ILs. In this study, a group contribution QSAR model has been used in order to predict the (eco)toxicity of protic and aprotic ILs for five tests (Microtox®, Pseudokirchneriella subcapitata and Lemna minor growth inhibition test, and Acetylcholinestherase inhibition and Cell viability assay with IPC-81 cells). The predicted and experimental toxicity are well correlated. A prediction of EC50 for these (eco)toxicity tests has also been made for eight representatives of the new family of short aliphatic protic ILs, whose toxicity has not been determined experimentally to date. The QSAR model applied in this study can allow the selection of potentially less toxic ILs amongst the existing ones (e.g. in the case of aprotic ILs), but it can also be very helpful in directing the synthesis efforts toward developing new "greener" ILs respectful with the environment (e.g. short aliphatic protic ILs).

  14. Preparation and characterization of protein loaded microspheres based on a hydroxylated aliphatic polyester, poly(lactic-co-hydroxymethyl glycolic acid).

    PubMed

    Ghassemi, A H; van Steenbergen, M J; Talsma, H; van Nostrum, C F; Jiskoot, W; Crommelin, D J A; Hennink, W E

    2009-08-19

    The purpose of this study was to investigate the suitability of a novel hydroxylated aliphatic polyester, poly(lactic-co-hydroxymethyl glycolic acid) (PLHMGA), as controlled release system for pharmaceutical proteins. Dextran Blue (as a macromolecular model compound) and lysozyme-loaded PLHMGA and PLGA (control formulation) microspheres were prepared by a solvent evaporation technique. The Dextran Blue and lysozyme loaded PLHMGA microspheres prepared with 10% polymer solution showed, because of a high porosity, a high burst release (35-75%) and the remaining content was released in a sustained manner for 15-20 days. The microspheres prepared with 15 and 20% polymer solution had a lower porosity and showed a pulsed release after day 8 and in 27 days they released more than 90% of Blue Dextran. The release of lysozyme was incomplete, likely due to aggregation of part of the encapsulated protein. Spectroscopic analysis of the released lysozyme indicated fully preserved secondary/tertiary structure and an enzyme activity assay showed that the specific activity of the released protein was maintained. An in vitro degradation study showed that the release of Blue Dextran and lysozyme is essentially controlled by the degradation of the microspheres. This study shows that microspheres made of the hydroxylated aliphatic polyester, poly(lactic-co-hydroxymethyl glycolic acid), are promising systems for the controlled release of pharmaceutical proteins.

  15. Simultaneous determination of aliphatic and aromatic amines in ambient air and airborne particulate matters by gas chromatography-mass spectrometry

    NASA Astrophysics Data System (ADS)

    Akyüz, Mehmet

    2008-05-01

    A gas chromatography-mass spectrometry (GC-MS) method has been proposed for the simultaneous determination of aliphatic and aromatic amines in ambient air and airborne particulate matters (PMs). The method includes collection of the particulate matters (PM2.5 and PM10) using dichotomous Partisol 2025 sampler followed by extraction of the compounds into acidic solution, and pre-concentration of the compounds by percolating the air samples through the acidic solution, then ion-pair extraction of amines with bis-2-ethylhexylphosphate and derivatisation with isobutyl chloroformate prior to their GC-MS analysis in both electron impact and positive and negative ion chemical ionisation mode as their isobutyloxycarbonyl (isoBOC) derivatives. In the present study, ambient air and airborne particulate samples collected in Zonguldak province during summer and winter times of 2006-2007 were analysed for aliphatic and aromatic amines by the proposed method and the method was shown to be suitable for the simultaneous determination of these compounds at the levels of pg m-3 in air and airborne particulate samples. The seasonal distributions of bioactive amines in concentrations in ambient air and airborne PMs were evaluated as they are significant for the estimation of their effects on the environment and human health. The concentration levels of water soluble amines fluctuate significantly within a year with higher means and peak concentrations, probably due to the increased emissions from coal-fired domestic and central heating, in the winter times compared to the summer times. The results indicated that the relative amine content in particulates modulates with molecular mass and time of the year and the relative amine content especially in fine fractions of inhalable airborne particulates increases with the molecular mass of species but decreases with temperature.

  16. Transient-state and steady-state kinetics of the oxidation of aliphatic and aromatic thiols by horseradish peroxidase.

    PubMed

    Burner, U; Obinger, C

    1997-07-14

    In the course of oxidation of thiols by peroxidases thiyl radicals are formed which are known to undergo several free-radical conjugative reactions, among others leading to hydrogen peroxide formation. The present paper for the first time presents a comparative transient-state and steady-state investigation of the reaction of 15 aliphatic and aromatic mono- and dithiols with horseradish peroxidase (HRP). Both sequential-stopped-flow spectrophotometric investigations of the reaction of HRP intermediates Compound I (k2) and Compound II (k3) with thiols and measurements of the overall thiol oxidation and the simultaneous oxygen consumption in the presence and absence of exogenously added hydrogen peroxide (10 microM) have been performed. With HRP as thiyl radical generator it was shown that three groups of thiols have to be distinguished: (i) Aromatic thiols (e.g. thiophenol, 2-mercaptopurine) were excellent electron donors of both Compounds (k2: 10(4)-10(7) M(-1) s(-1) and k3: 10(3)-10(6) M(-1) s(-1)); however, the overall reaction was shown to depend on addition of hydrogen peroxide, indicating insufficient peroxide regeneration by arylthiyl radicals. (ii) Aliphatic thiols which were extremely bad substrates (k3 < 10 M(-1) s(-1)) for HRP (e.g. homocysteine, glutathione) and/or have a pK(a,SH) > 9.5 (e.g. N-acetylcysteine, alpha-lipoic acid) were also shown to depend on exogenously added H2O2 to maintain the peroxidasic reaction, whereas (iii) with those thiols with rates of k3 between 11 and 1600 M(-1) s(-1) (e.g. cysteine, cysteamine, cysteine methyl ester, cysteine ethyl ester) and/or with a pK(a,SH) < 8 (penicillamine) thiol oxidation was independent of exogenously added hydrogen peroxide, indicating sufficient hydrogen peroxide regeneration.

  17. Influences of relative humidities and temperatures on the collection of C2-C5 aliphatic hydrocarbons with multi-bed (Tenax TA, Carbograph 1TD, Carboxen 1003) sorbent tube method

    NASA Astrophysics Data System (ADS)

    Ho, Steven Sai Hang; Chow, Judith C.; Watson, John G.; Wang, Liqin; Qu, Linli; Dai, Wenting; Huang, Yu; Cao, Junji

    2017-02-01

    Volatile organic compounds (VOCs) are measured with sorbent tubes followed by thermal desorption (TD) analysis. Water vapor in the atmosphere affects sampling breakthrough and results in low collection efficiency. This paper reports the effect of relative humidity (RH) and temperature on the collection of 57 ozone precursors with a multi-bed tube composed of three different strengths of adsorbents (Tenax TA, Carbograph 1 TD, and Carboxen 1003). Unacceptable breakthrough values for volatile C2-C5 aliphatic compounds were observed under high (>60%) RHs. The breakthrough volumes (BV) for C2 aliphatic compounds were reduced 13-22 fold under 90% RH. Dry-purge with inert helium gas removes excessive water content before the TD analysis but also causes a maximum of 40% loss of target analytes. Condensation is another pathway for water retention. The tube temperature should be regulated at 5-10 °C above the air temperature to minimize condensation under RHs >30%.

  18. 14C Incorporation into the Fatty Acids and Aliphatic Hydrocarbons of Sarcina lutea

    PubMed Central

    Tornabene, T. G.; Oró, J.

    1967-01-01

    An initial investigation into the mechanism of hydrocarbon biosynthesis in Sarcina lutea was performed by measuring the amounts of 14C incorporated into the hydrocarbons and fatty acids by use of a combination gas chromatograph and high-temperature gas-flow ionization apparatus. Uniformly labeled l-isoleucine-14C was predominantly incorporated into the anteiso-branched chains. Palmitate-16-14C gave evidence that a direct correlation may exist between the nonpolar end of the palmitate and the biosynthesis of hydrocarbons and carotenoids. The label from palmitate-1-14C was incorporated into the various hydrocarbon groups as a compound, derived from the polar end of the palmitate, consisting of more than two carbon atoms. Palmitate-16-14C and -1-14C gave no detectable evidence that transformed products were incorporated into other fatty acids. Sodium acetate-2-14C and uniformly labeled l-leucine-14C gave evidence of a nonspecific incorporation into both the aliphatic hydrocarbons and fatty acids of Sarcina lutea. PMID:6039358

  19. Oxidative aliphatic C-H fluorination with manganese catalysts and fluoride ion

    PubMed Central

    Liu, Wei; Huang, Xiongyi; Groves, John T

    2014-01-01

    Fluorination is a reaction that is useful in improving the chemical stability and changing the binding affinity of biologically active compounds. The protocol described here can be used to replace aliphatic, C(sp3)-H hydrogen in small molecules with fluorine. Notably, isolated methylene groups and unactivated benzylic sites are accessible. The method uses readily available manganese porphyrin and manganese salen catalysts and various fluoride ion reagents, including silver fluoride (AgF), tetrabutylammonium fluoride and triethylamine trihydrofluoride (TREAT·HF), as the source of fluorine. Typically, the reactions afford 50–70% yield of mono-fluorinated products in one step. Two representative examples, the fragrance component celestolide and the nonsteroidal anti-inflammatory drug ibuprofen, are described; they produced useful isolated quantities (250–300 mg, ~50% yield) of fluorinated material over periods of 1–8 h. The procedures are performed in a typical fume hood using ordinary laboratory glassware. No special precautions to rigorously exclude water are required. PMID:24177292

  20. Secondary organic aerosol formation from primary aliphatic amines with NO3 radical

    NASA Astrophysics Data System (ADS)

    Malloy, Q. G. J.; Qi, Li; Warren, B.; Cocker, D. R., III; Erupe, M. E.; Silva, P. J.

    2008-07-01

    Primary aliphatic amines are an important class of nitrogen containing compounds found to be emitted from automobiles, waste treatment facilities and agricultural animal operations. A series of experiments conducted at the UC-Riverside/CE-CERT Environmental Chamber is presented in which oxidation of methylamine, ethylamine, propylamine, and butylamine with NO3 has been investigated. Very little aerosol formation is observed in the presence of O3 only. However, after addition of NO, and by extension NO3, large yields of aerosol mass loadings (~44% for butylamine) are seen. Aerosol generated was determined to be organic in nature due to the small fraction of NO and NO2 in the total signal (<17% for all amines tested) as detected by an aerosol mass spectrometer (AMS). We propose a reaction mechanism between carbonyl containing species and the parent amine leading to formation of particulate imine products. These findings can have significant impacts on rural communities and lead to elevated nighttime PM loadings, when significant levels on NO3 exist.

  1. Secondary organic aerosol formation from primary aliphatic amines with NO3 radical

    NASA Astrophysics Data System (ADS)

    Malloy, Q. G. J.; Qi, Li; Warren, B.; Cocker, D. R., III; Erupe, M. E.; Silva, P. J.

    2009-03-01

    Primary aliphatic amines are an important class of nitrogen containing compounds emitted from automobiles, waste treatment facilities and agricultural animal operations. A series of experiments conducted at the UC-Riverside/CE-CERT Environmental Chamber is presented in which oxidation of methylamine, ethylamine, propylamine, and butylamine with O3 and NO3 have been investigated. Very little aerosol formation is observed in the presence of O3 only. However, after addition of NO, and by extension NO3, large aerosol mass yields (~44% for butylamine) are seen. Aerosol generated was determined to be organic in nature due to the small fraction of NO and NO2 in the total signal (<1% for all amines tested) as detected by an aerosol mass spectrometer (AMS). We propose a reaction mechanism between carbonyl containing species and the parent amine leading to formation of particulate imine products. These findings can have significant impacts on rural communities with elevated nighttime PM loadings, when significant levels of NO3 exist.

  2. The aliphatic amidase AmiE is involved in regulation of Pseudomonas aeruginosa virulence

    PubMed Central

    Clamens, Thomas; Rosay, Thibaut; Crépin, Alexandre; Grandjean, Teddy; Kentache, Takfarinas; Hardouin, Julie; Bortolotti, Perrine; Neidig, Anke; Mooij, Marlies; Hillion, Mélanie; Vieillard, Julien; Cosette, Pascal; Overhage, Joerg; O’Gara, Fergal; Bouffartigues, Emeline; Dufour, Alain; Chevalier, Sylvie; Guery, Benoit; Cornelis, Pierre; Feuilloley, Marc G. J.; Lesouhaitier, Olivier

    2017-01-01

    We have previously shown that the eukaryotic C-type natriuretic peptide hormone (CNP) regulates Pseudomonas aeruginosa virulence and biofilm formation after binding on the AmiC sensor, triggering the amiE transcription. Herein, the involvement of the aliphatic amidase AmiE in P. aeruginosa virulence regulation has been investigated. The proteome analysis of an AmiE over-producing strain (AmiE+) revealed an expression change for 138 proteins, including some that are involved in motility, synthesis of quorum sensing compounds and virulence regulation. We observed that the AmiE+ strain produced less biofilm compared to the wild type, and over-produced rhamnolipids. In the same line, AmiE is involved in P. aeruginosa motilities (swarming and twitching) and production of the quorum sensing molecules N-acyl homoserine lactones and Pseudomonas Quinolone Signal (PQS). We observed that AmiE overproduction reduced levels of HCN and pyocyanin causing a decreased virulence in different hosts (i.e. Dictyostelium discoideum and Caenorhabditis elegans). This phenotype was further confirmed in a mouse model of acute lung infection, in which AmiE overproduction resulted in an almost fully virulence decrease. Taken together, our data suggest that, in addition to its role in bacterial secondary metabolism, AmiE is involved in P. aeruginosa virulence regulation by modulating pilus synthesis and cell-to-cell communication. PMID:28117457

  3. Atmospheric chemistry of toxic contaminants 2. Saturated aliphatics: Acetaldehyde, dioxane, ethylene glycol ethers, propylene oxide

    SciTech Connect

    Grosjean, D. )

    1990-11-01

    Detailed mechanisms are outlined for the chemical reactions that contribute to in-situ formation and atmospheric removal of the saturated aliphatic contaminants acetaldehyde, dioxane, ethylene glycol ethers (methyl, ethyl, n-butyl) and propylene oxide. In-situ formation is of major importance for acetaldehyde. In-situ removal involves reaction with OH (all compounds) and, for acetaldehyde, photolysis and reaction with NO{sub 3}. Acetaldehyde, dioxane, and the ethers are rapidly removed (half-lives of less than one day), leading to PAN (acetaldehyde) and to 2-oxodioxane and formaldehyde (dioxane). Reaction products of the glycol ethers include a large number of hydroxyesters, hydroxyacids, and hydroxycarbonyls. Propylene oxide reacts only slowly with OH, with an atmospheric half-life of 3 - 10 days, to yeild formaldehyde, acetaldehyde, and PAN. Uncertainties in the reaction mechanisms for dioxane, the glycol ethers, and propylene oxide are discussed and include C-C vs C-O bond scission in alkoxy radicals as well as alkoxy radical unimolecular decomposition vs reaction with oxygen.

  4. Removal of aliphatic amino acids by hybrid organic inorganic layered compounds

    NASA Astrophysics Data System (ADS)

    Silverio, Fabiano; dos Reis, Márcio José; Tronto, Jairo; Valim, João Barros

    2007-04-01

    Amino acids have been extensively used in several processes of the pharmaceutical and food industries. Treatments for the recovery and reuse of the wastewaters generated from these processes are few and little known. This work aims at studying the influence of variables like temperature, pH and ionic strength on the adsorption of the amino acids Asp and Glu, contained in aqueous solutions, on layered double hydroxides of the Mg-Al-CO 3-LDH system. The adsorption experiments were performed at two different temperatures (298 and 310 K), two different pH values (7.0 and 10.0), and two ionic strength conditions (with or without the addition of NaCl). The adsorption isotherms exhibited similar profiles under the various conditions studied: an increase in temperature as well as an increase in the pH value decreased the amount of adsorbed amino acid while an increase in the ionic strength increased Asp and Glu adsorption. The PXRD analysis showed that the diffractograms obtained before and after the adsorption of amino acids have a similar pattern. The FT-IR spectra of the adsorbed material presented specific bands, which are related to the amino acids. The concentration range varied up to the anion solubility product and the extraction rate lay between 2.7 and 23.4% at higher equilibrium concentrations, showing that Mg-Al-CO 3-LDH is efficient at removing the amino acids from the aqueous medium.

  5. Linear aliphatic dialkynes as alternative linkers for double-click stapling of p53-derived peptides.

    PubMed

    Lau, Yu Heng; de Andrade, Peterson; McKenzie, Grahame J; Venkitaraman, Ashok R; Spring, David R

    2014-12-15

    We investigated linear aliphatic dialkynes as a new structural class of i,i+7 linkers for the double-click stapling of p53-based peptides. The optimal combination of azido amino acids and dialkynyl linker length for MDM2 binding was determined. In a direct comparison between aliphatic and aromatic staple scaffolds, the aliphatic staples resulted in superior binding to MDM2 in vitro and superior p53-activating capability in cells when using a diazidopeptide derived from phage display. This work demonstrates that the nature of the staple scaffold is an important factor that can affect peptide bioactivity in cells.

  6. New insight on aliphatic linkages in the macromolecular organic fraction of Orgueil and Murchison meteorites through ruthenium tetroxide oxidation

    NASA Astrophysics Data System (ADS)

    Remusat, Laurent; Derenne, Sylvie; Robert, François

    2005-09-01

    Ruthenium tetroxide oxidation was used to examine the macromolecular insoluble organic matter (IOM) from the Orgueil and Murchison meteorites and especially to characterize the aliphatic linkages. Already applied to various terrestrial samples, ruthenium tetroxide is a selective oxidant which destroys aromatic units, converting them into CO 2, and yields aliphatic and aromatic acids. In our experiment on chondritic IOM, it produces mainly short aliphatic diacids and polycarboxylic aromatic acids. Some short hydroxyacids are also detected. Aliphatic diacids are interpreted as aliphatic bridges between aromatic units in the chemical structure, and polycarboxylic aromatic acids are the result of the fusion of polyaromatic units. The product distribution shows that aliphatic links are short with numerous substitutions. No indigenous monocarboxylic acid was detected, showing that free aliphatic chains must be very short (less than three carbon atoms). The hydroxyacids are related to the occurrence of ester and ether functional groups within the aliphatic bridges between the aromatic units. This technique thus allows us to characterize in detail the aliphatic linkages of the IOMs, and the derived conclusions are in agreement with spectroscopic, pyrolytic, and degradative results previously reported. Compared to terrestrial samples, the aliphatic part of chondritic IOM is shorter and highly substituted. Aromatic units are smaller and more cross-linked than in coals, as already proposed from NMR data. Orgueil and Murchison IOM exhibit some tiny differences, especially in the length of aliphatic chains.

  7. Transferability of aliphatic isocyanates from recently applied paints to the skin of auto body shop workers.

    PubMed

    De Vries, Thomas T; Bello, Dhimiter; Stowe, Meredith H; Harari, Homero; Slade, Martin D; Redlich, Carrie A

    2012-01-01

    Isocyanates, the essential cross-linking chemicals used to make polyurethane, are potent sensitizers and a common cause of occupational asthma. In addition, isocyanate (NCO) skin contact may contribute to the development of isocyanate asthma. Prior work has shown that unbound NCO can persist on recently spray coated auto body parts after appearing dry. The purpose of this study was to assess whether isocyanate skin exposure can result from handling such surfaces. Quantitative surface and skin wipe sampling for total NCO was performed on test panels sprayed with aliphatic isocyanate coatings, and on paired skin samples obtained from participants who had rubbed the recently dried surfaces. Surface and skin samples, obtained from 18 workers in five auto body shops, were prepared following NIOSH method 5525 (modified for skin samples), and isocyanate species derived from hexamethylene diisocyanate and isophorone diisocyanate were analyzed using high-performance liquid chromatography with ultraviolet and fluorescence detectors. Quantifiable unbound NCO species were detected on 84.2% of all sprayed surfaces sampled after initially considered dry. Only 7 out of a total of 104 (6.7%) non-compounded skin samples obtained after contact with the recently dried coatings had detectable quantities of free NCO. The 7 positive samples, all obtained at the initial sampling time (t(0)), had a geometric mean of 0.016 μg NCO cm(-2) (range: 0.002-0.88 μg NCO cm(-2)). Only 1 of 12 (8.3%) of skin samples obtained after compounding contained detectable free NCO. The risk of substantial human isocyanate skin exposure from contact with the dry appearing (yet not fully cured) isocyanate coatings evaluated in this study appears to be low, although other isocyanate coatings and tasks may pose a greater risk of NCO skin exposure.

  8. Documents Related to the Hazardous Waste Listing of Chlorinated Aliphatics Production Wastes

    EPA Pesticide Factsheets

    Rulemaking information about the two waste streams from chlorinated aliphatics production that are listed as hazardous including links to the proposed and final rules and a fact sheet about the final rule.

  9. Catalytic water dissociation using hyperbranched aliphatic polyester (Boltorn series) as the interface of a bipolar membrane.

    PubMed

    Xue, Yanhong; Xu, Tongwen; Fu, Rongqiang; Cheng, Yiyun; Yang, Weihua

    2007-12-15

    The effect of hyperbranched aliphatic polyester (Boltorn series) on the water dissociation in bipolar membranes was firstly investigated in this paper. The bipolar membranes were prepared by immersing the anion exchange layer in a hyperbranched aliphatic polyester solution and then coating on the layer a polyphenylene oxide (SPPO) solution. The SEM observations proved the existence of hyperbranched aliphatic polyester at the membrane intermediate layer. The adsorption amount was evaluated by the oxygen content via XPS. The junction thickness of the prepared bipolar membrane was determined by electrochemical impedance spectroscopy (EIS), and the membrane performances were evaluated by current-voltage curves. The results showed that the amount and generation of Boltorn series, and temperature all affected I-V behaviors of the fabricated bipolar membranes, and the former two played the critical role. These effects were explained on the basis of the water dissociation theory and the characteristics of hyperbranched aliphatic polyester.

  10. Field Evaluations Test Plan for Validation of Alternatives to Aliphatic Isocyanate Polyurethanes

    NASA Technical Reports Server (NTRS)

    Lewis, Pattie

    2005-01-01

    The objective of this project is to qualify candidate alternatives to Aliphatic Isocyanate Polyurethane coatings under the specifications for the standard system. This project will compare coating performance of the proposed alternatives to existing coating systems or standards.

  11. Enhanced crystallization of poly (lactic acid) through reactive aliphatic bisamide

    NASA Astrophysics Data System (ADS)

    Nanthananon, P.; Seadan, M.; Pivsa-Art, S.; Suttiruengwong, S.

    2015-07-01

    The poor crystallization rate of poly (lactic acid) (PLA) is a major drawback in terms of controlling the properties of final products. To overcome this, a nucleating agent is normally applied. In this work, the aliphatic bisamide, N, N'-(1,3-propylene) bis(10-undecenamide) (PBU), having reactive functional groups is used as a crystallization promoter for PLA by adding PBU in various concentration (0.1-0.7 wt%) into PLA together with peroxide via reactive melt blending. The conventional ethylene bis-stearamide(EBS) is used for a comparison. The extruded samples are characterized for gel content and FT-IR spectroscopy. The crystallization behaviour and rate, and spherulites morphology are investigated by differential scanning calorimetry (DSC) and polarized optical microscopy (POM), respectively. It is found that the addition of PBU into PLA results in the dramatic increase in crystallinity and crystallization rate of PLA compared with neat PLA and PLA added EBS. The crystallinity increases to 24.9-28.3% higher than neat PLA under even cooling rate of 7°C/min. The addition of 0.7 wt% PBU shows the fastest crystallization rate with t1/2 value isothermally crystallized at 130°C of only 6 min. POM images indicate the increase in the nucleation density and very fine spherulitesof PLA added PBU, promoting the fast crystallization.

  12. Aliphatic polyesters for medical imaging and theranostic applications.

    PubMed

    Nottelet, Benjamin; Darcos, Vincent; Coudane, Jean

    2015-11-01

    Medical imaging is a cornerstone of modern medicine. In that context the development of innovative imaging systems combining biomaterials and contrast agents (CAs)/imaging probes (IPs) for improved diagnostic and theranostic applications focuses intense research efforts. In particular, the classical aliphatic (co)polyesters poly(lactide) (PLA), poly(lactide-co-glycolide) (PLGA) and poly(ɛ-caprolactone) (PCL), attract much attention due to their long track record in the medical field. This review aims therefore at providing a state-of-the-art of polyester-based imaging systems. In a first section a rapid description of the various imaging modalities, including magnetic resonance imaging (MRI), optical imaging, computed tomography (CT), ultrasound (US) and radionuclide imaging (SPECT, PET) will be given. Then, the two main strategies used to combine the CAs/IPs and the polyesters will be discussed. In more detail we will first present the strategies relying on CAs/IPs encapsulation in nanoparticles, micelles, dendrimers or capsules. We will then present chemical modifications of polyesters backbones and/or polyester surfaces to yield macromolecular imaging agents. Finally, opportunities offered by these innovative systems will be illustrated with some recent examples in the fields of cell labeling, diagnostic or theranostic applications and medical devices.

  13. Shape memory polymers based on uniform aliphatic urethane networks

    SciTech Connect

    Wilson, T S; Bearinger, J P; Herberg, J L; Marion III, J E; Wright, W J; Evans, C L; Maitland, D J

    2007-01-19

    Aliphatic urethane polymers have been synthesized and characterized, using monomers with high molecular symmetry, in order to form amorphous networks with very uniform supermolecular structures which can be used as photo-thermally actuable shape memory polymers (SMPs). The monomers used include hexamethylene diisocyanate (HDI), trimethylhexamethylenediamine (TMHDI), N,N,N{prime},N{prime}-tetrakis(hydroxypropyl)ethylenediamine (HPED), triethanolamine (TEA), and 1,3-butanediol (BD). The new polymers were characterized by solvent extraction, NMR, XPS, UV/VIS, DSC, DMTA, and tensile testing. The resulting polymers were found to be single phase amorphous networks with very high gel fraction, excellent optical clarity, and extremely sharp single glass transitions in the range of 34 to 153 C. Thermomechanical testing of these materials confirms their excellent shape memory behavior, high recovery force, and low mechanical hysteresis (especially on multiple cycles), effectively behaving as ideal elastomers above T{sub g}. We believe these materials represent a new and potentially important class of SMPs, and should be especially useful in applications such as biomedical microdevices.

  14. Process for the synthesis of aliphatic alcohol-containing mixtures

    DOEpatents

    Greene, Marvin I.; Gelbein, Abraham P.

    1984-01-01

    A process for the synthesis of mixtures which include saturated aliphatic alcohols is disclosed. In the first step of the process, the first catalyst activation stage, a catalyst, which comprises the oxides of copper, zinc, aluminum, potassium and one or two additional metals selected from the group consisting of chromium, magnesium, cerium, cobalt, thorium and lanthanum, is partially activated. In this step, a reducing gas stream, which includes hydrogen and at least one inert gas, flows past the catalyst at a space velocity of up to 5,000 liters (STP) per hour, per kilogram of catalyst. The partially activated catalyst is then subjected to the second step of the process, second-stage catalyst activation. In this step, the catalyst is contacted by an activation gas stream comprising hydrogen and carbon monoxide present in a volume ratio of 0.5:1 and 4:1, respectively, at a temperature of 200.degree. to 450.degree. C. and a pressure of between 35 and 200 atmospheres. The activation gas flows at a space velocity of from 1,000 to 20,000 liters (STP) per hour, per kilogram of catalyst. Second-stage activation continues until the catalyst is contacted with at least 500,000 liters (STP) of activation gas per kilogram of catalyst. The fully activated catalyst, in the third step of the process, contacts a synthesis gas stream comprising hydrogen and carbon monoxide.

  15. Process for the synthesis of aliphatic alcohol-containing mixtures

    DOEpatents

    Greene, M.I.; Gelbein, A.P.

    1984-10-16

    A process for the synthesis of mixtures which include saturated aliphatic alcohols is disclosed. In the first step of the process, the first catalyst activation stage, a catalyst, which comprises the oxides of copper, zinc, aluminum, potassium and one or two additional metals selected from the group consisting of chromium, magnesium, cerium, cobalt, thorium and lanthanum, is partially activated. In this step, a reducing gas stream, which includes hydrogen and at least one inert gas, flows past the catalyst at a space velocity of up to 5,000 liters (STP) per hour, per kilogram of catalyst. The partially activated catalyst is then subjected to the second step of the process, second-stage catalyst activation. In this step, the catalyst is contacted by an activation gas stream comprising hydrogen and carbon monoxide present in a volume ratio of 0.5:1 and 4:1, respectively, at a temperature of 200 to 450 C and a pressure of between 35 and 200 atmospheres. The activation gas flows at a space velocity of from 1,000 to 20,000 liters (STP) per hour, per kilogram of catalyst. Second-stage activation continues until the catalyst is contacted with at least 500,000 liters (STP) of activation gas per kilogram of catalyst. The fully activated catalyst, in the third step of the process, contacts a synthesis gas stream comprising hydrogen and carbon monoxide.

  16. The origin of aliphatic hydrocarbons in olive oil.

    PubMed

    Pineda, Manuel; Rojas, María; Gálvez-Valdivieso, Gregorio; Aguilar, Miguel

    2017-04-06

    There are many substances that can interfere with olive oil quality. Some of them are well characterized, but many others have an unknown origin. Saturated hydrocarbons make an extraordinary complex family of numerous molecules, some of them present naturally in vegetable oils. When major natural saturated hydrocarbons are analyzed by standard chromatographic methods, this complex mixture of saturated hydrocarbons appears as a hump in the chromatogram and is commonly named as unresolved complex mixture (UCM), whose origin remains unknown. In this work we studied the occurrence and the origin of aliphatic saturated hydrocarbons in olive oil. Hydrocarbons were analyzed in olive oil and along the industrial process of oil extraction. We also analyzed n-alkanes and the UCM fraction of hydrocarbons in leaf, fruit and oil from different varieties and different locations, and we also analyzed the soils at these locations. We conclude that the hydrocarbons present in olive oil do not necessarily have their origin in a contamination during olive oil elaboration; they seem to have a natural origin, as a result of olive tree metabolism and/or as the result of an intake and accumulation by the olive tree directly from the environment during its entire life cycle. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  17. Remote carboxylation of halogenated aliphatic hydrocarbons with carbon dioxide.

    PubMed

    Juliá-Hernández, Francisco; Moragas, Toni; Cornella, Josep; Martin, Ruben

    2017-05-03

    Catalytic carbon-carbon bond formation has enabled the streamlining of synthetic routes when assembling complex molecules. It is particularly important when incorporating saturated hydrocarbons, which are common motifs in petrochemicals and biologically relevant molecules. However, cross-coupling methods that involve alkyl electrophiles result in catalytic bond formation only at specific and previously functionalized sites. Here we describe a catalytic method that is capable of promoting carboxylation reactions at remote and unfunctionalized aliphatic sites with carbon dioxide at atmospheric pressure. The reaction occurs via selective migration of the catalyst along the hydrocarbon side-chain with excellent regio- and chemoselectivity, representing a remarkable reactivity relay when compared with classical cross-coupling reactions. Our results demonstrate that site-selectivity can be switched and controlled, enabling the functionalization of less-reactive positions in the presence of a priori more reactive ones. Furthermore, we show that raw materials obtained in bulk from petroleum processing, such as alkanes and unrefined mixtures of olefins, can be used as substrates. This offers an opportunity to integrate a catalytic platform en route to valuable fatty acids by transforming petroleum-derived feedstocks directly.

  18. Aliphatic hydrocarbons in Great Barrier Reef organisms and environment

    NASA Astrophysics Data System (ADS)

    Coates, M.; Connell, D. W.; Bodero, J.; Miller, G. J.; Back, R.

    1986-07-01

    This investigation was undertaken to assess the chemical nature, occurrence, and possible origin of petroleum hydrocarbons in the Great Barrier Reef ecosystem. Aliphatic hydrocarbons in surface sediments, water, and a suite of seven species from widely separated coral reefs in the Great Barrier Reef area were analysed by gas chromatography, and by gas chromatography coupled with mass spectrometry. The hydrocarbons found were substantially of biogenic origin. The major components were n-pentadecane, n-heptadecane, pristane and mono-alkenes based on heptadecane, and were believed to originate from benthic algae and phytoplankton. There was no evidence to suggest that lipid content had any influence on hydrocarbon content. Hydrocarbons from the organisms and sediments have characteristic composition patterns which would be altered by the presence of petroleum hydrocarbons. An unresolved complex mixture, usually considered indicative of petroleum contamination, was found in greater than trace amounts only in Holothuria (sea cucumber) and Acropora (coral) from the Capricorn Group, and in some sediment samples from the Capricorn Group and Lizard Island area.

  19. Aliphatic and aromatic hydrocarbons in the mediterranean aerosol.

    PubMed

    Sicre, M A; Marty, J C; Saliot, A; Aparicio, X; Grimalt, J; Albaiges, J

    1987-01-01

    The atmospheric transport of organic pollutants over long distances and their effect on the biological cycles of the sea are two major questions of concern in environmental chemistry. These processes are of particular importance in the Mediterranean Sea because of its semi-enclosed characteristics, which determine the accumulation of the pollutants entering into the system. In order to get some insight into these processes a project (PHYCEMED), was developed for the evaluation of the atmospheric budget of organic and inorganic substances in the Western Mediterranean and for the investigation of the exchange mechanisms of these materials across the air/sea interface. A high volume air sampling system including a cascade impactor was placed on board of the R/V le Suroit for collecting the aerosols along several transects parallel to the French, Spanish and North-African coasts, facing areas of different population densities and industrial activities. The cruise was realised on October 1983 and the particulate material was fractionated into the following sizes: 7.2, 3.0, 1.5, 0.96, and 0.03 micron. Quantitative and qualitative analyses of the aliphatic and the aromatic hydrocarbons present in these fractions were performed by high resolution gas chromatography and gas chromatography-mass spectrometry.

  20. Remote carboxylation of halogenated aliphatic hydrocarbons with carbon dioxide

    NASA Astrophysics Data System (ADS)

    Juliá-Hernández, Francisco; Moragas, Toni; Cornella, Josep; Martin, Ruben

    2017-05-01

    Catalytic carbon-carbon bond formation has enabled the streamlining of synthetic routes when assembling complex molecules. It is particularly important when incorporating saturated hydrocarbons, which are common motifs in petrochemicals and biologically relevant molecules. However, cross-coupling methods that involve alkyl electrophiles result in catalytic bond formation only at specific and previously functionalized sites. Here we describe a catalytic method that is capable of promoting carboxylation reactions at remote and unfunctionalized aliphatic sites with carbon dioxide at atmospheric pressure. The reaction occurs via selective migration of the catalyst along the hydrocarbon side-chain with excellent regio- and chemoselectivity, representing a remarkable reactivity relay when compared with classical cross-coupling reactions. Our results demonstrate that site-selectivity can be switched and controlled, enabling the functionalization of less-reactive positions in the presence of a priori more reactive ones. Furthermore, we show that raw materials obtained in bulk from petroleum processing, such as alkanes and unrefined mixtures of olefins, can be used as substrates. This offers an opportunity to integrate a catalytic platform en route to valuable fatty acids by transforming petroleum-derived feedstocks directly.

  1. Room-temperature Cu-catalyzed N-arylation of aliphatic amines in neat water.

    PubMed

    Wang, Deping; Zheng, Yanwen; Yang, Min; Zhang, Fuxing; Mao, Fangfang; Yu, Jiangxi; Xia, Xiaohong

    2017-09-18

    A room-temperature and PTC-free copper-catalyzed N-arylation of aliphatic amines in neat water has been developed. Using a combination of CuI and 6,7-dihydroquinolin-8(5H)-one oxime as the catalyst and KOH as the base, a wide range of aliphatic amines are arylated with various aryl and heteroaryl halides to give the corresponding products in up to 95% yield.

  2. Base-Mediated One-Pot Synthesis of Aliphatic Diazirines for Photoaffinity Labeling.

    PubMed

    Wang, Lei; Tachrim, Zetryana Puteri; Kurokawa, Natsumi; Ohashi, Fumina; Sakihama, Yasuko; Hashidoko, Yasuyuki; Hashimoto, Makoto

    2017-08-22

    Aliphatic diazirines have been widely used as prominent photophores for photoaffinity labeling owing to their relatively small size which can reduce the steric effect on the natural interaction between ligands and proteins. Based on our continuous efforts to develop efficient methods for the synthesis of aliphatic diazirines, we present here a comprehensive study about base-mediated one-pot synthesis of aliphatic diazirines. It was found that potassium hydroxide (KOH) can also promote the construction of aliphatic diazirine with good efficiency. Importantly, KOH is cheaper, highly available, and easily handled and stored compared with the previously used base, potassium tert-butoxide (t-BuOK). Gram-scale study showed that it owned great advantages in being used for the large-scale production of aliphatic diazirines. This protocol is highly neat and the desired products can be easily isolated and purified. As the first comprehensive study of the base-mediated one-pot synthesis of aliphatic diazirines, this work provided good insight into the preparation and utilization of diazirine-based photoaffinity labeling probes.

  3. Microbe-aliphatic hydrocarbon interactions in soil: implications for biodegradation and bioremediation.

    PubMed

    Stroud, J L; Paton, G I; Semple, K T

    2007-05-01

    Aliphatic hydrocarbons make up a substantial portion of organic contamination in the terrestrial environment. However, most studies have focussed on the fate and behaviour of aromatic contaminants in soil. Despite structural differences between aromatic and aliphatic hydrocarbons, both classes of contaminants are subject to physicochemical processes, which can affect the degree of loss, sequestration and interaction with soil microflora. Given the nature of hydrocarbon contamination of soils and the importance of bioremediation strategies, understanding the fate and behaviour of aliphatic hydrocarbons is imperative, particularly microbe-contaminant interactions. Biodegradation by microbes is the key removal process of hydrocarbons in soils, which is controlled by hydrocarbon physicochemistry, environmental conditions, bioavailability and the presence of catabolically active microbes. Therefore, the aims of this review are (i) to consider the physicochemical properties of aliphatic hydrocarbons and highlight mechanisms controlling their fate and behaviour in soil; (ii) to discuss the bioavailability and bioaccessibility of aliphatic hydrocarbons in soil, with particular attention being paid to biodegradation, and (iii) to briefly consider bioremediation techniques that may be applied to remove aliphatic hydrocarbons from soil.

  4. Sources and distribution of aliphatic and polyaromatic hydrocarbons in sediments from the Neuquen River, Argentine Patagonia.

    PubMed

    Monza, Liliana B; Loewy, Ruth M; Savini, Mónica C; Pechen de d'Angelo, Ana M

    2013-01-01

    Spatial distribution and probable sources of aliphatic and polyaromatic hydrocarbons (AHs, PAHs) were investigated in surface sediments collected along the bank of the Neuquen River, Argentina. Total concentrations of aliphatic hydrocarbons ranged between 0.41 and 125 μg/g dw. Six stations presented low values of resolved aliphatic hydrocarbons and the n-alkane distribution indexes applied suggested a clear biogenic source. These values can be considered the baseline levels of aliphatic hydrocarbons for the river sediments. This constitutes important information for the assessment of future impacts since a strong impulse in the exploitation of shale gas and shale oil in these zones is nowadays undergoing. For the other 11 stations, a mixture of aliphatic hydrocarbons of petrogenic and biogenic origin was observed. The spatial distribution reflects local inputs of these pollutants with a significant increase in concentrations in the lower course, where two major cities are located. The highest values of total aliphatic hydrocarbons were found in this sector which, in turn, was the only one where individual PAHs were detected.

  5. Synthesis of novel naphthoquinone aliphatic amides and esters and their anticancer evaluation.

    PubMed

    Kongkathip, Boonsong; Akkarasamiyo, Sunisa; Hasitapan, Komkrit; Sittikul, Pichamon; Boonyalai, Nonlawat; Kongkathip, Ngampong

    2013-02-01

    Fourteen new naphthoquinone aliphatic amides and seventeen naphthoquinone aliphatic esters were synthesized in nine to ten steps from 1-hydroxy-2-naphthoic acid with 9-25% overall yield for the amides, and 16-21% overall yield for the esters. The key step of the amide synthesis is a coupling reaction between amine and various aliphatic acids using 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMTMM) as a coupling agent while for the ester synthesis, DCC/DMAP or CDI was used as the coupling reagent between aliphatic acids and naphthoquinone alcohol. Both naphthoquinone amides and esters were evaluated for their anticancer activity against KB cells. It was found that naphthoquinone aliphatic amides showed stronger anticancer activity than those of the esters when the chains are longer than 7-carbon atoms. The optimum chain of amides is expected to be 16-carbon atoms. In addition, naphthoquinone aliphatic esters with α-methyl on the ester moiety possessed much stronger anticancer activity than the straight chains. Decatenation assay revealed that naphthoquinone amide with 16-carbon atoms chain at 15 μM and 20 μM can completely inhibit hTopoIIα activity while at 10 μM the enzyme activity was moderately inhibited. Molecular docking result also showed the same trend as the cytotoxicity and decatenation assay.

  6. A THEORETICAL STUDY ON THE VIBRATIONAL SPECTRA OF POLYCYCLIC AROMATIC HYDROCARBON MOLECULES WITH ALIPHATIC SIDEGROUPS

    SciTech Connect

    Sadjadi, SeyedAbdolreza; Zhang, Yong; Kwok, Sun

    2015-03-01

    The role of aliphatic side groups in the formation of astronomical unidentified infrared emission (UIE) features is investigated by applying the density functional theory to a series of molecules with mixed aliphatic-aromatic structures. The effects of introducing various aliphatic groups to a fixed polycyclic aromatic hydrocarbon (PAH) core (ovalene) are studied. Simulated spectra for each molecule are produced by applying a Drude profile at T = 500 K while the molecule is kept at its electronic ground state. The vibrational normal modes are classified using a semi-quantitative method. This allows us to separate the aromatic and aliphatic vibrations, and therefore provides clues to what types of vibrations are responsible for the emissions bands at different wavelengths. We find that many of the UIE bands are not pure aromatic vibrational bands but may represent coupled vibrational modes. The effects of aliphatic groups on the formation of the 8 μm plateau are quantitatively determined. The vibrational motions of methyl (–CH{sub 3}) and methylene (–CH{sub 2} –) groups can cause the merging of the vibrational bands of the parent PAH and the forming of broad features. These results suggest that aliphatic structures can play an important role in the UIE phenomenon.

  7. THE CARRIERS OF THE INTERSTELLAR UNIDENTIFIED INFRARED EMISSION FEATURES: AROMATIC OR ALIPHATIC?

    SciTech Connect

    Li Aigen; Draine, B. T. E-mail: draine@astro.princeton.edu

    2012-12-01

    The unidentified infrared emission (UIE) features at 3.3, 6.2, 7.7, 8.6, and 11.3 {mu}m, commonly attributed to polycyclic aromatic hydrocarbon (PAH) molecules, have been recently ascribed to coal- or kerogen-like organic nanoparticles with a mixed aromatic-aliphatic structure. However, we show in this Letter that this hypothesis is inconsistent with observations. We estimate the aliphatic fraction of the UIE carriers based on the observed intensities of the 3.4 {mu}m and 6.85 {mu}m emission features by attributing them exclusively to aliphatic C-H stretch and aliphatic C-H deformation vibrational modes, respectively. We derive the fraction of carbon atoms in aliphatic form to be <15%. We conclude that the UIE emitters are predominantly aromatic, with aliphatic material at most a minor part of the UIE carriers. The PAH model is consistent with astronomical observations and PAHs dominate the strong UIE bands.

  8. Aliphatic polyester block polymers: renewable, degradable, and sustainable.

    PubMed

    Hillmyer, Marc A; Tolman, William B

    2014-08-19

    Nearly all polymers are derived from nonrenewable fossil resources, and their disposal at their end of use presents significant environmental problems. Nonetheless, polymers are ubiquitous, key components in myriad technologies and are simply indispensible for modern society. An important overarching goal in contemporary polymer research is to develop sustainable alternatives to "petro-polymers" that have competitive performance properties and price, are derived from renewable resources, and may be easily and safely recycled or degraded. Aliphatic polyesters are particularly attractive targets that may be prepared in highly controlled fashion by ring-opening polymerization of bioderived lactones. However, property profiles of polyesters derived from single monomers (homopolymers) can limit their applications, thus demanding alternative strategies. One such strategy is to link distinct polymeric segments in an A-B-A fashion, with A and B chosen to be thermodynamically incompatible so that they can self-organize on a nanometer-length scale and adopt morphologies that endow them with tunable properties. For example, such triblock copolymers can be useful as thermoplastic elastomers, in pressure sensitive adhesive formulations, and as toughening modifiers. Inspired by the tremendous utility of petroleum-derived styrenic triblock copolymers, we aimed to develop syntheses and understand the structure-property profiles of sustainable alternatives, focusing on all renewable and all readily degradable aliphatic polyester triblocks as targets. Building upon oxidation chemistry reported more than a century ago, a constituent of the peppermint plant, (-)-menthol, was converted to the ε-caprolactone derivative menthide. Using a diol initiator and controlled catalysis, menthide was polymerized to yield a low glass transition temperature telechelic polymer (PM) that was then further functionalized using the biomass-derived monomer lactide (LA) to yield fully renewable PLA

  9. Spatial and temporal distribution of aliphatic hydrocarbons and linear alkylbenzenes in the particulate phase from a subtropical estuary (Guaratuba Bay, SW Atlantic) under seasonal population fluctuation.

    PubMed

    Dauner, Ana Lúcia L; Martins, César C

    2015-12-01

    Guaratuba Bay, a subtropical estuary located in the SW Atlantic, is under variable anthropogenic pressure throughout the year. Samples of surficial suspended particulate matter (SPM) were collected at 22 sites during three different periods to evaluate the temporal and spatial variability of aliphatic hydrocarbons (AHs) and linear alkylbenzenes (LABs). These compounds were determined by gas chromatography with flame ionization detection (GC-FID) and mass spectrometry (GC/MS). The spatial distributions of both compound classes were similar and varied among the sampling campaigns. Generally, the highest concentrations were observed during the austral summer, highlighting the importance of the increased human influence during this season. The compound distributions were also affected by the natural geochemical processes of organic matter accumulation. AHs were associated with petroleum, derived from boat and vehicle traffic, and biogenic sources, related to mangrove forests and autochthonous production. The LAB composition evidenced preferential degradation processes during the austral summer. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Novel derivatives of deoxycholic acid bearing aliphatic or cyclic diamine moieties at the C-3 position: Synthesis and evaluation of anti-proliferative activity.

    PubMed

    Popadyuk, Irina I; Markov, Andrey V; Babich, Valeriya O; Salomatina, Oksana V; Logashenko, Evgeniya B; Zenkova, Marina A; Salakhutdinov, Nariman F

    2017-08-15

    A new library of deoxycholic acid derivatives bearing nitrogen-containing moieties at the C-3 position was synthesised from epoxy derivative 1 via an epoxide ring-opening reaction promoted by aliphatic or cyclic diamines and fully characterised by NMR and mass-spectroscopy. The synthesised compounds were screened for cytotoxicity against four human tumour cell lines. The results showed that some of the novel diamine-bearing derivatives displayed improved anti-proliferative activities over the parent compound DCA. Among them, a 1-methylpiperazine containing compound (6) showed promising activity and the highest selectivity against tumour cells of enterohepatic origin (HepG2: IC50=3.6µM, SI=9.0; HuTu-80: IC50=4.6µM, SI=6.9) and was identified as a lead molecule. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Acid-base thermochemistry of gaseous aliphatic α-aminoacids.

    PubMed

    Bouchoux, Guy; Huang, Sihua; Inda, Bhawani Singh

    2011-01-14

    Acid-base thermochemistry of isolated aliphatic amino acids (denoted AAA): glycine, alanine, valine, leucine, isoleucine and proline has been examined theoretically by quantum chemical computations at the G3MP2B3 level. Conformational analysis on neutral, protonated and deprotonated species has been used to identify the lowest energy conformers and to estimate the population of conformers expected to be present at thermal equilibrium at 298 K. Comparison of the G3MP2B3 theoretical proton affinities, PA, and ΔH(acid) with experimental results is shown to be correct if experimental thermochemistry is re-evaluated and adapted to the most recent acidity-basicity scales. From this point of view, a set of evaluated proton affinities of 887, 902, 915, 916, 919 and 941 kJ mol(-1), and a set of evaluated ΔH(acid) of 1433, 1430, 1423, 1423, 1422 and 1426 kJ mol(-1), is proposed for glycine, alanine, valine, leucine, isoleucine and proline, respectively. Correlations with structural parameters (Taft's σ(α) polarizability parameter and molecular size) suggest that polarizability of the side chain is the major origin of the increase in PA and decrease in ΔH(acid) along the homologous series glycine, alanine, valine and leucine/isoleucine. Heats of formation of gaseous species AAA, AAAH(+) and [AAA-H](-) were computed at the G3MP2B3 level. The present study provides previously unavailable Δ(f)H°(298) for the ionized species AAAH(+) and [AAA-H](-). Comparison with Benson's estimate, and correlation with molecular size, show that several experimental Δ(f)H°(298) values of neutral or gaseous AAA might be erroneous.

  12. Separation and conductimetric detection of C1-C7 aliphatic monocarboxylic acids and C1-C7 aliphatic monoamines on unfunctionized polymethacrylate resin columns.

    PubMed

    Ohta, Kazutoku; Towata, Atsuya; Ohashi, Masayoshi; Takeuchi, Toyohide

    2004-06-11

    The application of unfunctionized polymethacrylate resin (TSKgel G3000PWXL) as a stationary phase in liquid chromatography with conductimetric detection for C1-C7 aliphatic monocarboxylic acids (formic acid, acetic acid, propionic acid, butyric acid, isovaleric acid, valeric acid, 3,3-dimethylbutyric acid, 4-methylvaleric acid, hexanoic acid, 2-methylhexanoic acid, 5-methylhexanoic acid and heptanoic acid) and C1-C7 aliphatic monoamines (methylamine, ethylamine, propylamine, isobutylamine, butylamine, isoamylamine, amylamine, 1,3-dimethylbutylamine, hexylamine, 2-heptylamine and heptylamine) was attempted with C8 aliphatic monocarboxylic acids (2-propylvaleric acid, 2-ethylhexanoic acid, 2-methylheptanoic acid and octanoic acid) and C8 aliphatic monoamines (1,5-dimethylhexylamine, 2-ethylhexylamine, 1-methylheptylamine and octylamine) as eluents, respectively. Using 1 mM 2-methylheptanoic acid at pH 4.0 as the eluent, excellent separation and relatively high sensitive detection for these C1-C7 carboxylic acids were achieved on a TSKgel G3000PWXL column (150 mm x 6 mm i.d.) in 60 min. Using 2 mM octylamine at pH 11.0 as the eluent, excellent separation and relatively high sensitive detection for these C1-C7 amines were also achieved on the TSKgel G3000PWXL column in 60 min.

  13. Hafnium trifluoromethanesulfonate (hafnium triflate) as a highly efficient catalyst for chemoselective thioacetalization and transthioacetalization of carbonyl compounds.

    PubMed

    Wu, Yan-Chao; Zhu, Jieping

    2008-12-05

    A range of carbonyl compounds including aliphatic and aromatic aldehydes and ketones were converted to the corresponding thioacetals in high yields in the presence of a catalytic amount of hafnium trifluoromethanesulfonate (0.1 mol %, room temperature). The mild conditions tolerated various sensitive functional and protecting groups and were racemization-free when applied to alpha-aminoaldehydes. Transacetalization and chemoselective thioacetalization of aromatic aldehydes in the presence of aliphatic aldehydes and ketones were also documented.

  14. Aromatic and aliphatic organic materials on Iapetus: Analysis of Cassini VIMS data

    NASA Astrophysics Data System (ADS)

    Cruikshank, Dale P.; Dalle Ore, Cristina M.; Clark, Roger N.; Pendleton, Yvonne J.

    2014-05-01

    , D.P., Clark, R.N. [2012], op. cit.) and Phoebe (Dalle Ore, C.M., Cruikshank, D.P., Clark, R.N. [2012], op. cit.). Our Gaussian decomposition of the organic band region suggests the presence of molecular bands in addition to those noted above, specifically bands attributable to cycloalkanes, olefinic compounds, CH3OH, and N-substituted PAHs, as well as possible Hn-PAHs (PAHs with excess peripheral H atoms). In a minimalist interpretation of the Gaussian band fitting, we find the ratio of aromatic CH to aliphatic CH2 + CH3 functional groups for both the leading and trailing hemispheres of Iapetus is ∼10, with no clear difference between them. In the aliphatic component of the surface material, the ratio CH2/CH3 is 4.0 on the leading hemisphere and 3.0 on the trailing; both values are higher than those found in interstellar dust and other Solar System materials and the difference between the two hemispheres may be statistically significant. The superficial layer of low-albedo material on Iapetus originated in the interior of Phoebe and is being transported to and deposited on Iapetus (and Hyperion) in the current epoch via the Phoebe dust ring (Tosi, F., Turrini, D., Coradini, A., Filacchione, G., and the VIMS Team [2010]. Mon. Not. R. Astron. Soc. 403, 1113-1130; Tamayo, D., Burns, J.A., Hamilton, D.P., Hedman, M.M. [2011]. Icarus 215, 260-278). The PAHs on Iapetus exist in a H2O-rich environment, and consequently are subject to UV destruction by hydrogenation on short time-scales. The occurrence of this material is therefore consistent with the assertion that the deposition of the PAH-bearing dust is occurring at the present time. If the organic inventory we observe represents the interior composition of Phoebe, we may be sampling the original material from a region of the solar nebula beyond Neptune where Phoebe formed prior to its capture by Saturn (Johnson, T.V., Lunine, J.I. [2005]. Nature 435, 69-71).

  15. Degradation kinetics of chlorinated aliphatic hydrocarbons by methane oxidizers naturally-associated with wetland plant roots

    NASA Astrophysics Data System (ADS)

    Powell, C. L.; Goltz, M. N.; Agrawal, A.

    2014-12-01

    Chlorinated aliphatic hydrocarbons (CAHs) are common groundwater contaminants that can be removed from the environment by natural attenuation processes. CAH biodegradation can occur in wetland environments by reductive dechlorination as well as oxidation pathways. In particular, CAH oxidation may occur in vegetated wetlands, by microorganisms that are naturally associated with the roots of wetland plants. The main objective of this study was to evaluate the cometabolic degradation kinetics of the CAHs, cis-1,2-dichloroethene (cisDCE), trichloroethene (TCE), and 1,1,1-trichloroethane (1,1,1TCA), by methane-oxidizing bacteria associated with the roots of a typical wetland plant in soil-free system. Laboratory microcosms with washed live roots investigated aerobic, cometabolic degradation of CAHs by the root-associated methane-oxidizing bacteria at initial aqueous [CH4] ~ 1.9 mg L- 1, and initial aqueous [CAH] ~ 150 μg L- 1; cisDCE and TCE (in the presence of 1,1,1TCA) degraded significantly, with a removal efficiency of approximately 90% and 46%, respectively. 1,1,1TCA degradation was not observed in the presence of active methane oxidizers. The pseudo first-order degradation rate-constants of TCE and cisDCE were 0.12 ± 0.01 and 0.59 ± 0.07 d- 1, respectively, which are comparable to published values. However, their biomass-normalized degradation rate constants obtained in this study were significantly smaller than pure-culture studies, yet they were comparable to values reported for biofilm systems. The study suggests that CAH removal in wetland plant roots may be comparable to processes within biofilms. This has led us to speculate that the active biomass may be on the root surface as a biofilm. The cisDCE and TCE mass losses due to methane oxidizers in this study offer insight into the role of shallow, vegetated wetlands as an environmental sink for such xenobiotic compounds.

  16. Nanosecond flash studies of reduction of benzophenone by aliphatic amines. Quantum yields and kinetic isotope effects

    SciTech Connect

    Inbar, S.; Linschitz, H.; Cohen, S.G.

    1981-03-11

    Nanosecond flash photolysis, steady irradiation, and deuterium substitution studies have been carried out on solutions of benzophenone with added reductants. Quantum yields (phi/sub ketyl/) for reduction in benzene of benzophenone triplet to ketyl radical, based on phi = 2 for benzhydrol (I), were approx. 1 for cyclohexane (II), tert-butylamine (III), 2-aminobutane (IV), cyclohexylamine (V), di-n-propylamine (VI), and triethylamine (VII), approx. 0.7 for 1,4-diazabicyclo(2.2.2)octane (VIII), and approx. 0 for tert-butyl alcohol (IX). Thus, quenching, without radical formation by H abstraction from N and/or ..cap alpha..-C, does not occur with common aliphatic amines but does with Dabco (VIII). The latter quenching is markedly increased by small additions of acetonitrile; the flash spectrum from this compound indicates formation of a triplet amine CT complex or radical ion pair. Triplet-reductant interaction rate constants, k/sur ir/, are high for the amines (approx. 10/sup 8/-10/sup 9/ M/sup -1/ s/sup -1/) but also show significant deuterium kinetic isotope effects: 1.9 with III-N-d/sub 2/; 1.4 with IV-N-d/sub 2/; 1.2-1.3 with IV-..cap alpha..-C-d. It is proposed that k/sub ir/ measures H atom abstraction, favored in the transition state by an initial charge-transfer interaction. Overall steady irradiation quantum yields of reduction by amines, phi/sub Red/, are much lower than phi/sub ketyl/. This is attributed to disproportionationreactions of ketyl and alkylaminyl radicals for primary and secondary amines, and, possibly, aminoalkyl radicals for tertiary amines. In the case of tert-butylamine, the rate constant for disproportionation is obtained from the decay kinetics of ketyl radical and leads to phi/sub Red/ in agreement with that directly measured.

  17. Biodegradation of nitroaromatic compounds.

    PubMed

    Spain, J C

    1995-01-01

    Nitroaromatic compounds are released into the biosphere almost exclusively from anthropogenic sources. Some compounds are produced by incomplete combustion of fossil fuels; others are used as synthetic intermediates, dyes, pesticides, and explosives. Recent research revealed a number of microbial systems capable of transforming or biodegrading nitroaromatic compounds. Anaerobic bacteria can reduce the nitro group via nitroso and hydroxylamino intermediates to the corresponding amines. Isolates of Desulfovibrio spp. can use nitroaromatic compounds as their source of nitrogen. They can also reduce 2,4,6-trinitrotoluene to 2,4,6-triaminotoluene. Several strains of Clostridium can catalyze a similar reduction and also seem to be able to degrade the molecule to small aliphatic acids. Anaerobic systems have been demonstrated to destroy munitions and pesticides in soil. Fungi can extensively degrade or mineralize a variety of nitroaromatic compounds. For example, Phanerochaete chrysosporium mineralizes 2,4-dinitrotoluene and 2,4,6-trinitrotoluene and shows promise as the basis for bioremediation strategies. The anaerobic bacteria and the fungi mentioned above mostly transform nitroaromatic compounds via fortuitous reactions. In contrast, a number of nitroaromatic compounds can serve as growth substrates for aerobic bacteria. Removal or productive metabolism of nitro groups can be accomplished by four different strategies. (a) Some bacteria can reduce the aromatic ring of dinitro and trinitro compounds by the addition of a hydride ion to form a hydride-Meisenheimer complex, which subsequently rearomatizes with the elimination of nitrite. (b) Monooxygenase enzymes can add a single oxygen atom and eliminate the nitro group from nitrophenols. (c) Dioxygenase enzymes can insert two hydroxyl groups into the aromatic ring and precipitate the spontaneous elimination of the nitro group from a variety of nitroaromatic compounds. (d) Reduction of the nitro group to the corresponding

  18. Aliphatic acetogenin constituents of avocado fruits inhibit human oral cancer cell proliferation by targeting the EGFR/RAS/RAF/MEK/ERK1/2 pathway

    PubMed Central

    D’Ambrosio, Steven M.; Han, Chunhua; Pan, Li; Kinghorn, A. Douglas; Ding, Haiming

    2011-01-01

    Avocado (Persea americana) fruits are consumed as part of the human diet and extracts have shown growth inhibitory effects in various types of human cancer cells, although the effectiveness of individual components and their underlying mechanism are poorly understood. Using activity-guided fractionation of the flesh of avocado fruits, a chloroform-soluble extract (D003), was identified that exhibited high efficacy towards premalignant and malignant human oral cancer cell lines. From this extract, two aliphatic acetogenins of previously known structure were isolated, compounds 1 [(2S,4S)-2,4-dihydroxyheptadec-16-enyl acetate] and 2 [(2S,4S)-2,4-dihydroxyheptadec-16-ynyl acetate]. In this study, we show for the first time that the growth inhibitory efficacy of this chloroform extract is due to blocking the phosphorylation of EGFR (Tyr1173), c-RAF (Ser338), and ERK1/2 (Thr202/Tyr204) in the EGFR/RAS/RAF/MEK/ERK1/2 cancer pathway. Compound 1 and 2 both inhibited phosphorylation of c-RAF (Ser338) and ERK1/2 (Thr202/Tyr204). Compound 2, but not compound 1, prevented EGF-induced activation of EGFR (Tyr1173). When compounds 1 and 2 were combined they synergistically inhibited c-RAF (Ser338) and ERK1/2 (Thr202/Tyr204) phosphorylation, and human oral cancer cell proliferation. The present data suggest that the potential anticancer activity of avocado fruits is due to a combination of specific aliphatic acetogenins that target two key components of the EGFR/RAS/RAF/MEK/ERK1/2 cancer pathway. PMID:21596018

  19. Aliphatic acetogenin constituents of avocado fruits inhibit human oral cancer cell proliferation by targeting the EGFR/RAS/RAF/MEK/ERK1/2 pathway.

    PubMed

    D'Ambrosio, Steven M; Han, Chunhua; Pan, Li; Kinghorn, A Douglas; Ding, Haiming

    2011-06-10

    Avocado (Persea americana) fruits are consumed as part of the human diet and extracts have shown growth inhibitory effects in various types of human cancer cells, although the effectiveness of individual components and their underlying mechanism are poorly understood. Using activity-guided fractionation of the flesh of avocado fruits, a chloroform-soluble extract (D003) was identified that exhibited high efficacy towards premalignant and malignant human oral cancer cell lines. From this extract, two aliphatic acetogenins of previously known structure were isolated, compounds 1 [(2S,4S)-2,4-dihydroxyheptadec-16-enyl acetate] and 2 [(2S,4S)-2,4-dihydroxyheptadec-16-ynyl acetate]. In this study, we show for the first time that the growth inhibitory efficacy of this chloroform extract is due to blocking the phosphorylation of EGFR (Tyr1173), c-RAF (Ser338), and ERK1/2 (Thr202/Tyr204) in the EGFR/RAS/RAF/MEK/ERK1/2 cancer pathway. Compounds 1 and 2 both inhibited phosphorylation of c-RAF (Ser338) and ERK1/2 (Thr202/Tyr204). Compound 2, but not compound 1, prevented EGF-induced activation of the EGFR (Tyr1173). When compounds 1 and 2 were combined they synergistically inhibited c-RAF (Ser338) and ERK1/2 (Thr202/Tyr204) phosphorylation, and human oral cancer cell proliferation. The present data suggest that the potential anticancer activity of avocado fruits is due to a combination of specific aliphatic acetogenins that target two key components of the EGFR/RAS/RAF/MEK/ERK1/2 cancer pathway. Copyright © 2011 Elsevier Inc. All rights reserved.

  20. Perfluorinated Compounds as Test Media for Porous Membranes.

    PubMed

    Clodt, Juliana I; Filiz, Volkan; Shishatskiy, Sergey

    2017-09-05

    We suggest a failure-free method of porous membranes characterization that gives the researcher the opportunity to compare and characterize properties of any porous membrane. This proposal is supported by an investigation of eight membranes made of different organic and inorganic materials, with nine different perfluorinated compounds. It was found that aromatic compounds, perfluorobenzene, and perfluorotoluene, used in the current study show properties different from other perfluorinated aliphatics. They demonstrate extreme deviation from the general sequence indicating the existence of π-π-interaction on the pore wall. The divergence of the flow for cyclic compounds from ideal e.g., linear compounds can be an indication of the pore dimension.

  1. Aliphatic amines in Antarctic CR2, CM2, and CM1/2 carbonaceous chondrites

    NASA Astrophysics Data System (ADS)

    Aponte, José C.; McLain, Hannah L.; Dworkin, Jason P.; Elsila, Jamie E.

    2016-09-01

    Meteoritic water-soluble organic compounds provide a unique record of the processes that occurred during the formation of the solar system and the chemistry preceding the origins of life on Earth. We have investigated the molecular distribution, compound-specific δ13C isotopic ratios and enantiomeric compositions of aliphatic monoamines present in the hot acid-water extracts of the carbonaceous chondrites LAP 02342 (CR2), GRA 95229 (CR2), LON 94101 (CM2), LEW 90500 (CM2), and ALH 83100 (CM1/2). Analyses of the concentration of monoamines in these meteorites revealed: (a) the CR2 chondrites studied here contain higher concentrations of monoamines relative to the analyzed CM2 chondrites; (b) the concentration of monoamines decreases with increasing carbon number; and (c) isopropylamine is the most abundant monoamine in these CR2 chondrites, while methylamine is the most abundant amine species in these CM2 and CM1/2 chondrites. The δ13C values of monoamines in CR2 chondrite do not correlate with the number of carbon atoms; however, in CM2 and CM1/2 chondrites, the 13C enrichment decreases with increasing monoamine carbon number. The δ13C values of methylamine in CR2 chondrites ranged from -1 to +10‰, while in CM2 and CM1/2 chondrites the δ13C values of methylamine ranged from +41 to +59‰. We also observed racemic compositions of sec-butylamine, 3-methyl-2-butylamine, and sec-pentylamine in the studied carbonaceous chondrites. Additionally, we compared the abundance and δ13C isotopic composition of monoamines to those of their structurally related amino acids. We found that monoamines are less abundant than amino acids in CR2 chondrites, with the opposite being true in CM2 and CM1/2 chondrites. We used these collective data to evaluate different primordial synthetic pathways for monoamines in carbonaceous chondrites and to understand the potential common origins these molecules may share with meteoritic amino acids.

  2. Aliphatic Amines in Antarctic CR2, CM2, and CM1/2 Carbonaceous Chondrites

    NASA Technical Reports Server (NTRS)

    Aponte, Jose C.; McLain, Hannah L.; Dworkin, Jason P.; Elsila, Jamie E.

    2016-01-01

    Meteoritic water-soluble organic compounds provide a unique record of the processes that occurred during the formation of the solar system and the chemistry preceding the origins of life on Earth. We have investigated the molecular distribution, compound-specific delta13C isotopic ratios and enantiomeric compositions of aliphatic monoamines present in the hot acid-water extracts of the carbonaceous chondrites LAP 02342 (CR2), GRA 95229 (CR2), LON 94101 (CM2), LEW 90500 (CM2), and ALH 83100 (CM1/2). Analyses of the concentration of monoamines in these meteorites revealed: (a) the CR2 chondrites studied here contain higher concentrations of monoamines relative to the analyzed CM2 chondrites; (b) the concentration of monoamines decreases with increasing carbon number; and (c) isopropylamine is the most abundant monoamine in these CR2 chondrites, while methylamine is the most abundant amine species in these CM2 and CM1/2 chondrites. The delta13C values of monoamines in CR2 chondrite do not correlate with the number of carbon atoms; however, in CM2 and CM1/2 chondrites, the 13C enrichment decreases with increasing monoamine carbon number. The delta13C values of methylamine in CR2 chondrites ranged from -1 to +10per mille, while in CM2 and CM1/2 chondrites the delta13C values of methylamine ranged from +41 to +59per mille. We also observed racemic compositions of sec-butylamine, 3-methyl-2-butylamine, and sec-pentylamine in the studied carbonaceous chondrites. Additionally, we compared the abundance and delta13C isotopic composition of monoamines to those of their structurally related amino acids. We found that monoamines are less abundant than amino acids in CR2 chondrites, with the opposite being true in CM2 and CM1/2 chondrites. We used these collective data to evaluate different primordial synthetic pathways for monoamines in carbonaceous chondrites and to understand the potential common origins these molecules may share with meteoritic amino acids.

  3. Suberin-derived aliphatic monomers as biomarkers for SOM affected by root litter contribution

    NASA Astrophysics Data System (ADS)

    Kogel-Knabner, I.; Spielvogel, S.-; Prietzel, J.-

    2012-12-01

    The patchy distribution of trees and ground vegetation may have major impact on SOC variability and stability at the small scale. Knowledge about correlations between the pattern of tree and ground vegetation, SOC stocks in different soil depths and the contribution of root- vs. shoot-derived carbon to different SOC fractions is scarce. We have tested analysis of hydrolysable aliphatic monomers derived from the biopolyesters cutin- and suberin to investigate whether their composition can be traced back after decay and transformation into soil organic matter (SOM) to study SOM source, degradation, and stand history. The main objective of this study was to elucidate the relative abundance of cutin and suberin in different particle size and density fractions of a Norway spruce and a European beech site with increasing distance to stems. Soil samples, root, bark and needle/leave samples were analyzed for their cutin and/or suberin signature. Previous to isolation of bound lipids, sequential solvent extraction was used to remove free lipids and other solvent extractable compounds. Cutin- and suberin-derived monomers were extracted from the samples using base hydrolysis. Before analysis by Gas Chromatography/Mass Spectrometry (GC/MS), extracts were derivatized to convert compounds to trimethylsilyl derivatives. Statistical analysis identified four variables which as combined factors discriminated significantly between cutin and suberin based on their structural units. We found a relative enrichment of cutin and suberin contents in the occluded fraction at both sites that decreased with increasing distance to the trees. We conclude from our results that (i) patchy above- and belowground carbon input caused by heterogeneous distribution of trees and ground vegetation has major impact on SOC variability and stability at the small scale, (ii) tree species is an important factor influencing SOC heterogeneity at the stand scale due to pronounced differences in above- and

  4. Manganese-catalyzed late-stage aliphatic C-H azidation.

    PubMed

    Huang, Xiongyi; Bergsten, Tova M; Groves, John T

    2015-04-29

    We report a manganese-catalyzed aliphatic C-H azidation reaction that can efficiently convert secondary, tertiary, and benzylic C-H bonds to the corresponding azides. The method utilizes aqueous sodium azide solution as the azide source and can be performed under air. Besides its operational simplicity, the potential of this method for late-stage functionalization has been demonstrated by successful azidation of various bioactive molecules with yields up to 74%, including the important drugs pregabalin, memantine, and the antimalarial artemisinin. Azidation of celestolide with a chiral manganese salen catalyst afforded the azide product in 70% ee, representing a Mn-catalyzed enantioselective aliphatic C-H azidation reaction. Considering the versatile roles of organic azides in modern chemistry and the ubiquity of aliphatic C-H bonds in organic molecules, we envision that this Mn-azidation method will find wide application in organic synthesis, drug discovery, and chemical biology.

  5. STIMULATION BY HYDROCHLORIC ACID AND BY THE NORMAL ALIPHATIC ACIDS IN THE SUNFISH EUPOMOTIS

    PubMed Central

    Allison, James B.

    1932-01-01

    1. The reaction of the sunfish, Eupomotis gibbosus, to different concentrations of hydrochloric acid and of the first six members of the N aliphatic acids has been studied. 2. The stimulating efficiency of hydrochloric acid may best be related to the concentration of hydrogen ions produced by that acid. 3. The stimulating efficiency of the N aliphatic acids may best be correlated with the non-polar nature of a portion of the molecule, but it is necessary to consider the higher potential of the polar group of formic acid to account satisfactorily for its position in the series. 4. When equally effective concentrations of the N aliphatic acids are compared, formic acid is more effective at lower concentrations than at higher. 5. Per cent variation in response appears to be independent of the chemical environment to which the animal responded. PMID:19872671

  6. Access to aliphatic protons as reporters in non-deuterated proteins by solid-state NMR.

    PubMed

    Vasa, Suresh Kumar; Rovó, Petra; Giller, Karin; Becker, Stefan; Linser, Rasmus

    2016-03-28

    Interactions within proteins, with their surrounding, and with other molecules are mediated mostly by hydrogen atoms. In fully protonated, inhomogeneous, or larger proteins, however, aliphatic proton shifts tend to show little dispersion despite fast Magic-Angle Spinning. 3D correlations dispersing aliphatic proton shifts by their better resolved amide N/H shifts can alleviate this problem. Using inverse second-order cross-polarization (iSOCP), we here introduce dedicated and improved means to sensitively link site-specific chemical shift information from aliphatic protons with a backbone amide resolution. Thus, even in cases where protein deuteration is impossible, this approach may enable access to various aspects of protein functions that are reported on by protons.

  7. Aliphatic Hydrocarbons in Surface Sediments of Willapa Bay and Grays Harbor, Washington

    USGS Publications Warehouse

    Rapp, J.B.; Kvenvolden, K.A.; Clifton, H.E.

    1982-01-01

    Willapa Bay and Grays Harbor are two adjacent estuaries along the coast of Washington state. Willapa Bay is a recreational area minimally affected by industry; Grays Harbor, on the other hand, is moderately industrialized. Aliphatic hydrocarbons in surface sediments from these two estuaries reflect the differences in human activities. For example, the mean concentration of aliphatic hydrocarbons for seven stations in Willapa Bay is 1,000 ?g/g (relative to organic carbon) while in Grays Harbor this mean concentration for six stations is 1,900 ?g/g. The difference is attributed mainly to the greater urban and industrial pollution in Grays Harbor. The gas chromatographic records of aliphatic hydrocarbons also reflect the extent of hydrocarbon pollution by the presence of a chromatographically unresolved mixture of hydrocarbons. This kind of mixture is more evident in sediments from Grays Harbor, and in both estuaries it is more concentrated in sediments collected nearest to urban centers.

  8. Aliphatic amine responsive organogel system based on a simple naphthalimide derivative.

    PubMed

    Cao, Xinhua; Zhang, Tingting; Gao, Aiping; Li, Keli; Cheng, Qiuli; Song, Lijuan; Zhang, Min

    2014-09-07

    A new gelator 1 based on a simple naphthalimide derivative was synthesized and fully characterized. It was found that the organogel 1 was formed only in a mixed solvent of methanol and H2O (1/1, v/v). The organogel was thoroughly characterized by using various microscopic techniques including field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), and UV-vis, fluorescence and Fourier transform infrared (FTIR) spectroscopy. Hydrogen bonds were the main driving force for the organogel formation. Interestingly, the organogel 1 exhibited the ability to distinguish aliphatic amines from aromatic amines. The gel state and fluorescence emission intensity were both changed after two minutes after the addition of aliphatic amines. This organogel system could be applied in the detection of aliphatic amine pollutants.

  9. Seasonal distribution of aliphatic hydrocarbons in the Vaza Barris Estuarine System, Sergipe, Brazil.

    PubMed

    Barbosa, José Carlos S; Santos, Lukas G G V; Sant'Anna, Mércia V S; Souza, Michel R R; Damasceno, Flaviana C; Alexandre, Marcelo R

    2016-03-15

    The seasonal assessment of anthropogenic activities in the Vaza Barris estuarine river system, located in the Sergipe state, northeastern Brazil, was performed using the aliphatic hydrocarbon distribution. The aliphatic hydrocarbon and isoprenoid (Pristane and Phytane) concentrations ranged between 0.19 μg g(-1) and 8.5 μg g(-1) of dry weight. Data were analyzed using Kruskal-Wallis test, with significance level set at p<0.05, and no seasonality distribution change was observed. The Carbon Preference Index (CPI), associated with n-alkanes/n-C16, Low Molecular Weight/High Molecular Weight ratio (LMW/HMW) and Terrigenous to Aquatic Ratio (TAR) suggested biogenic input of aliphatic hydrocarbons for most samples, with significant contribution of higher plants. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. The effect of aliphatic fuel constituents on the biodegradation of polycyclic aromatic hydrocarbons

    SciTech Connect

    Gamerdinger, A.P.

    1995-12-01

    In petroleum-derived waste, n-alkanes are often codeposited with polycyclic aromatic hydrocarbons (PAHs). The impact of aliphatic fuel constituents on the biodegradation of the more toxic PAHs is considered. Biodegradation of naphthalene by a Coryneform bacteria was examined in biphasic, slurry systems containing and aliphatic solvent in addition to the aqueous phase. The effect of solvent hydrophobicity was evaluated by varying the solvent treatment; a homologous series of n-alkanes was used. Relative to an aqueous system (no solvent), the extent of naphthalene degradation was enhanced in the presence of decane, dodecane, and hexadecane. Biodegradation was apparent, but decreased in the presence of octane, and was completely absent in the presence of hexane. The impact of aliphatic constituents on PAH biodegradation is a function of solvent hydrophobicity. The results indicate that the presence of multiple chemical constituents in complex systems modifies bioavailability and biodegradation.

  11. Selectivity patterns in micellar electrokinetic chromatography: characterization of fluorinated and aliphatic alcohol modifiers by micellar selectivity triangle.

    PubMed

    Fu, Cexiong; Khaledi, Morteza G

    2009-03-06

    The usefulness of the micellar selectivity triangle (MST) for prediction and interpretation of separation patterns in micellar electrokinetic chromatography (MEKC) separations is presented. In addition, we demonstrate the capability of controlling selectivity properties of micelles through addition of organic modifiers with known solvation properties as predicted by MST. The examples are modification of the hydrogen bond donor (HBD) micelle of lithium perfluorooctanesulfonate, the hydrogen bond acceptor (HBA) micelle of tetradecyltrimethylammonium bromide, and the sodium dodecyl sulfate micelles with intermediate hydrogen bonding properties with two hydrophobic organic modifiers. One is an aliphatic alcohol, n-pentanol that can act as both a HBA and a HBD; by contrast, the other organic modifier is a fluorinated alcohol, hexafluoroisopropanol that is a strong HBD modifier and would enhance the hydrogen bond donor strength of micelles. A test sample composed of 20 small organic solutes representing HBA, HBD, and non-hydrogen bond aromatic compounds was carefully selected. The trends in retention behavior of these compounds in different micelles are consistent with the selectivity patterns predicted by the MST scheme. To the best of our knowledge, this is the first report on the unique selectivity of fluorinated alcohols as modifiers in MEKC. These results demonstrate the usefulness of the MST scheme for identifying pseudo-phases with highly similar or different selectivities and can serve as a guide for judicious selection of modifiers to create pseudo-phases with desired selectivity behavior on a rational basis.

  12. Preliminary chemical analysis and biological testing of materials from the HRI catalytic two-stage liquefaction (CTSL) process. [Aliphatic hydrocarbons

    SciTech Connect

    Later, D.W.; Wilson, B.W.

    1985-01-01

    Coal-derived materials from experimental runs of Hydrocarbon Research Incorporated's (HRI) catalytic two-stage liquefaction (CTSL) process were chemically characterized and screened for microbial mutagenicity. This process differs from two-stage coal liquefaction processes in that catalyst is used in both stages. Samples from both the first and second stages were class-fractionated by alumina adsorption chromatography. The fractions were analyzed by capillary column gas chromatography; gas chromatography/mass spectrometry; direct probe, low voltage mass spectrometry; and proton nuclear magnetic resonance spectrometry. Mutagenicity assays were performed with the crude and class fractions in Salmonella typhimurium, TA98. Preliminary results of chemical analyses indicate that >80% CTSL materials from both process stages were aliphatic hydrocarbon and polynuclear aromatic hydrocarbon (PAH) compounds. Furthermore, the gross and specific chemical composition of process materials from the first stage were very similar to those of the second stage. In general, the unfractionated materials were only slightly active in the TA98 mutagenicity assay. Like other coal liquefaction materials investigated in this laboratory, the nitrogen-containing polycyclic aromatic compound (N-PAC) class fractions were responsible for the bulk of the mutagenic activity of the crudes. Finally, it was shown that this activity correlated with the presence of amino-PAH. 20 figures, 9 tables.

  13. Chiral separation of short chain aliphatic hydroxycarboxylic acids on cinchonan carbamate-based weak chiral anion exchangers and zwitterionic chiral ion exchangers.

    PubMed

    Calderón, Carlos; Lämmerhofer, Michael

    2017-03-03

    Chiral short chain aliphatic hydrocarboxylic acids (HCAs) are common compounds being part of different biological processes. In order to control and understand these processes is of pivotal importance to determine the identity of the involved enantiomer or their enantiomeric ratio. In this study the capacity of quinine- and quinidine-derived chiral stationary phases to perform the enantioseparation of eight chiral HCAs (tartaric acid, isocitric acid, malic acid, glyceric acid, 2-hydroxyglutaric acid, 2-hydroxybutyric acid, lactic acid and 3-hydroxybutyric acid) was evaluated. MS-compatible conditions consisting of ACN/MeOH mixtures as eluents with formic acid, acetic acid and/or their ammonium salts as additives, temperatures between 10 and 25°C (except for -20°C for 3-hydroxybutyric acid) and a flow rate of 1.00mL/min yielded full baseline resolution for all studied HCAs. Elution order for the HCA enantiomers was determined revealing different behaviors between the studied compounds.

  14. Folding and self-assembly of aromatic and aliphatic urea oligomers: towards connecting structure and function.

    PubMed

    Fischer, Lucile; Guichard, Gilles

    2010-07-21

    Folding and self-assembly of biomacromolecules has inspired the development of discrete, non-natural oligomers that fold and/or self-assemble in a controlled manner. Though aromatic and aliphatic oligoamides remain unmatched for structural diversity and synthetic versatility, oligomers based on amide bond surrogates, such as urea backbones, also demonstrated a propensity for folding and self-assembly. In this Perspective, we review the advances in the design of oligomeric aromatic and aliphatic urea sequences (essentially N,N'-linked) that fold and/or self-assemble. Whenever applicable, the relationship between structure and function will be highlighted.

  15. On the aliphatic versus aromatic content of the carriers of the `unidentified' infrared emission features

    NASA Astrophysics Data System (ADS)

    Yang, X. J.; Glaser, R.; Li, Aigen; Zhong, J. X.

    2016-10-01

    Although it is generally accepted that the unidentified infrared emission (UIE) features at 3.3, 6.2, 7.7, 8.6, and 11.3 μm are characteristic of the stretching and bending vibrations of aromatic hydrocarbon materials, the exact nature of their carriers remains unknown: whether they are free-flying, predominantly aromatic gas-phase molecules, or amorphous solids with a mixed aromatic/aliphatic composition are being debated. Recently, the 3.3 and 3.4 μm features which are commonly respectively attributed to aromatic and aliphatic C-H stretches have been used to place an upper limit of ˜2 per cent on the aliphatic fraction of the UIE carriers (i.e. the number of C atoms in aliphatic chains to that in aromatic rings). Here we further explore the aliphatic versus aromatic content of the UIE carriers by examining the ratio of the observed intensity of the 6.2 μm aromatic C-C feature (I6.2) to that of the 6.85 μm aliphatic C-H deformation feature (I6.85). To derive the intrinsic oscillator strengths of the 6.2 μm stretch (A6.2) and the 6.85 μm deformation (A6.85), we employ density functional theory to compute the vibrational spectra of seven methylated polycyclic aromatic hydrocarbon molecules and their cations. By comparing I6.85/I6.2 with A6.85/A6.2, we derive the fraction of C atoms in methyl(ene) aliphatic form to be at most ˜10 per cent, confirming the earlier finding that the UIE emitters are predominantly aromatic. We have also computed the intrinsic strength of the 7.25 μm feature (A7.25), another aliphatic C-H deformation band. We find that A6.85 appreciably exceeds A7.25. This explains why the 6.85 μm feature is more frequently detected in space than the 7.25 μm feature.

  16. An Iminium Salt Organocatalyst for Selective Aliphatic C-H Hydroxylation.

    PubMed

    Wang, Daoyong; Shuler, William G; Pierce, Conor J; Hilinski, Michael K

    2016-08-05

    The first examples of catalysis of aliphatic C-H hydroxylation by an iminium salt are presented. The method allows the selective organocatalytic hydroxylation of unactivated 3° C-H bonds at room temperature using hydrogen peroxide as the terminal oxidant. Hydroxylation of an unactivated 2° C-H bond is also demonstrated. Furthermore, improved functional group compatibility over other catalytic methods is reported in the form of selectivity for aliphatic C-H hydroxylation over alcohol oxidation. On the basis of initial mechanistic studies, an oxaziridinium species is proposed as the active oxidant.

  17. Iron-Catalyzed Decarboxylative Alkyl Etherification of Vinylarenes with Aliphatic Acids as the Alkyl Source.

    PubMed

    Jian, Wujun; Ge, Liang; Jiao, Yihang; Qian, Bo; Bao, Hongli

    2017-03-20

    Because of the lack of effective alkylating reagents, alkyl etherification of olefins with general alkyl groups has not been previously reported. In this work, a variety of alkyl diacyl peroxides and peresters generated from aliphatic acids have been found to enable the first iron-catalyzed alkyl etherification of olefins with general alkyl groups. Primary, secondary and tertiary aliphatic acids are suitable for this reaction, delivering products with yields up to 97 %. Primary and secondary alcohols react well, affording products in up to 91 % yield.

  18. A proof for negative vicinal proton-proton and proton-carbon spin-spin couplings in aliphatic aldehydes by using temperature and solvent dependence. Conformational studies on glycolaldehyde and di- tert-butyl ethanal

    NASA Astrophysics Data System (ADS)

    Laatikainen, Reino; Král, Vladimir; Äyräs, Pertti

    A negative 1H, 1H three-bond coupling 3J( CHO), H) was found for glycolaldehyde by varying solvent composition. A negative 3J( CHO), C) is demonstrated for di- tert-butyl ethanal by following the temperature dependence of the coupling. 3JgB( CHO), H) of -0.73 and 3Jg( CHO), C) of -0.26 Hz (g = gauche) for the compounds were estimated by fitting the temperature dependence of the couplings by using the two-site approach. The conformational behavior of the vicinal couplings in aliphatic aldehydes and the conformations of the title compounds are briefly discussed.

  19. The Cer-cqu gene cluster determines three key players in a β-diketone synthase polyketide pathway synthesizing aliphatics in epicuticular waxes

    PubMed Central

    Schneider, Lizette M; Adamski, Nikolai M; Christensen, Caspar Elo; Stuart, David B; Vautrin, Sonia; Hansson, Mats; Uauy, Cristobal; von Wettstein-Knowles, Penny

    2016-01-01

    Aliphatic compounds on plant surfaces, called epicuticular waxes, are the first line of defense against pathogens and pests, contribute to reducing water loss and determine other important phenotypes. Aliphatics can form crystals affecting light refraction, resulting in a color change and allowing identification of mutants in their synthesis or transport. The present study discloses three such Eceriferum (cer) genes in barley – Cer-c, Cer-q and Cer-u – known to be tightly linked and functioning in a biochemical pathway forming dominating amounts of β-diketone and hydroxy-β-diketones plus some esterified alkan-2-ols. These aliphatics are present in many Triticeae as well as dicotyledons such as Eucalyptus and Dianthus. Recently developed genomic resources and mapping populations in barley defined these genes to a small region on chromosome arm 2HS. Exploiting Cer-c and -u potential functions pinpointed five candidates, of which three were missing in apparent cer-cqu triple mutants. Sequencing more than 50 independent mutants for each gene confirmed their identification. Cer-c is a chalcone synthase-like polyketide synthase, designated diketone synthase (DKS), Cer-q is a lipase/carboxyl transferase and Cer-u is a P450 enzyme. All were highly expressed in pertinent leaf sheath tissue of wild type. A physical map revealed the order Cer-c, Cer-u, Cer-q with the flanking genes 101kb apart, confirming they are a gene cluster, Cer-cqu. Homology-based modeling suggests that many of the mutant alleles affect overall protein structure or specific active site residues. The rich diversity of identified mutations will facilitate future studies of three key enzymes involved in synthesis of plant apoplast waxes. PMID:26962211

  20. The Cer-cqu gene cluster determines three key players in a β-diketone synthase polyketide pathway synthesizing aliphatics in epicuticular waxes.

    PubMed

    Schneider, Lizette M; Adamski, Nikolai M; Christensen, Caspar Elo; Stuart, David B; Vautrin, Sonia; Hansson, Mats; Uauy, Cristobal; von Wettstein-Knowles, Penny

    2016-03-09

    Aliphatic compounds on plant surfaces, called epicuticular waxes, are the first line of defense against pathogens and pests, contribute to reducing water loss and determine other important phenotypes. Aliphatics can form crystals affecting light refraction, resulting in a color change and allowing identification of mutants in their synthesis or transport. The present study discloses three such Eceriferum (cer) genes in barley - Cer-c, Cer-q and Cer-u - known to be tightly linked and functioning in a biochemical pathway forming dominating amounts of β-diketone and hydroxy-β-diketones plus some esterified alkan-2-ols. These aliphatics are present in many Triticeae as well as dicotyledons such as Eucalyptus and Dianthus. Recently developed genomic resources and mapping populations in barley defined these genes to a small region on chromosome arm 2HS. Exploiting Cer-c and -u potential functions pinpointed five candidates, of which three were missing in apparent cer-cqu triple mutants. Sequencing more than 50 independent mutants for each gene confirmed their identification. Cer-c is a chalcone synthase-like polyketide synthase, designated diketone synthase (DKS), Cer-q is a lipase/carboxyl transferase and Cer-u is a P450 enzyme. All were highly expressed in pertinent leaf sheath tissue of wild type. A physical map revealed the order Cer-c, Cer-u, Cer-q with the flanking genes 101kb apart, confirming they are a gene cluster, Cer-cqu. Homology-based modeling suggests that many of the mutant alleles affect overall protein structure or specific active site residues. The rich diversity of identified mutations will facilitate future studies of three key enzymes involved in synthesis of plant apoplast waxes.

  1. A Search for CD36 Ligands from Flavor Volatiles in Foods with an Aldehyde Moiety: Identification of Saturated Aliphatic Aldehydes with 9-16 Carbon Atoms as Potential Ligands of the Receptor.

    PubMed

    Tsuzuki, Satoshi; Amitsuka, Takahiko; Okahashi, Tatsuya; Kimoto, Yusaku; Inoue, Kazuo

    2017-08-09

    Volatile compounds with an aldehyde moiety such as (Z)-9-octadecenal are potential ligands for cluster of differentiation 36 (CD36), a transmembrane receptor that has recently been shown to play a role in mammalian olfaction. In this study, by performing an assay using a peptide mimic of human CD36, we aimed to discover additional ligands for the receptor from volatiles containing a single aldehyde group commonly found in human foods. Straight-chain, saturated aliphatic aldehydes with 9-16 carbons exhibited CD36 ligand activities, albeit to varying degrees. Notably, the activities of tridecanal and tetradecanal were higher than that of oleic acid, the most potent ligand among the fatty acids tested. Among the aldehydes other than aliphatic aldehydes, only phenylacetaldehyde showed a weak activity. These findings make a contribution to our knowledge of recognition mechanisms for flavor volatiles in foods with an aldehyde group.

  2. 40 CFR 721.10188 - Fatty acids, tall-oil, reaction products with 4-methyl-2-pentanone and aliphatic polyamine...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Fatty acids, tall-oil, reaction... Fatty acids, tall-oil, reaction products with 4-methyl-2-pentanone and aliphatic polyamine (generic). (a... generically as fatty acids, tall-oil, reaction products with 4-methyl-2-pentanone and aliphatic polyamine...

  3. 40 CFR 721.10188 - Fatty acids, tall-oil, reaction products with 4-methyl-2-pentanone and aliphatic polyamine...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Fatty acids, tall-oil, reaction... Fatty acids, tall-oil, reaction products with 4-methyl-2-pentanone and aliphatic polyamine (generic). (a... generically as fatty acids, tall-oil, reaction products with 4-methyl-2-pentanone and aliphatic polyamine...

  4. 40 CFR 721.10188 - Fatty acids, tall-oil, reaction products with 4-methyl-2-pentanone and aliphatic polyamine...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Fatty acids, tall-oil, reaction... Fatty acids, tall-oil, reaction products with 4-methyl-2-pentanone and aliphatic polyamine (generic). (a... generically as fatty acids, tall-oil, reaction products with 4-methyl-2-pentanone and aliphatic polyamine...

  5. 40 CFR 721.10190 - Formaldehyde, polymer with aliphatic diamine and phenol, reaction products with 4-methyl-2...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... diamine and phenol, reaction products with 4-methyl-2-pentanone (generic). 721.10190 Section 721.10190... Formaldehyde, polymer with aliphatic diamine and phenol, reaction products with 4-methyl-2-pentanone (generic... identified generically as formaldehyde, polymer with aliphatic diamine and phenol, reaction products with...

  6. 40 CFR 721.10190 - Formaldehyde, polymer with aliphatic diamine and phenol, reaction products with 4-methyl-2...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... diamine and phenol, reaction products with 4-methyl-2-pentanone (generic). 721.10190 Section 721.10190... Formaldehyde, polymer with aliphatic diamine and phenol, reaction products with 4-methyl-2-pentanone (generic... identified generically as formaldehyde, polymer with aliphatic diamine and phenol, reaction products with...

  7. 40 CFR 721.10190 - Formaldehyde, polymer with aliphatic diamine and phenol, reaction products with 4-methyl-2...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... diamine and phenol, reaction products with 4-methyl-2-pentanone (generic). 721.10190 Section 721.10190... Formaldehyde, polymer with aliphatic diamine and phenol, reaction products with 4-methyl-2-pentanone (generic... identified generically as formaldehyde, polymer with aliphatic diamine and phenol, reaction products with...

  8. 40 CFR 721.10188 - Fatty acids, tall-oil, reaction products with 4-methyl-2-pentanone and aliphatic polyamine...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Fatty acids, tall-oil, reaction... Fatty acids, tall-oil, reaction products with 4-methyl-2-pentanone and aliphatic polyamine (generic). (a... generically as fatty acids, tall-oil, reaction products with 4-methyl-2-pentanone and aliphatic polyamine...

  9. 40 CFR 721.10188 - Fatty acids, tall-oil, reaction products with 4-methyl-2-pentanone and aliphatic polyamine...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Fatty acids, tall-oil, reaction... Fatty acids, tall-oil, reaction products with 4-methyl-2-pentanone and aliphatic polyamine (generic). (a... generically as fatty acids, tall-oil, reaction products with 4-methyl-2-pentanone and aliphatic polyamine...

  10. Delivery of complex organic compounds from evolved stars to the solar system.

    PubMed

    Kwok, Sun

    2011-12-01

    Stars in the late stages of evolution are able to synthesize complex organic compounds with aromatic and aliphatic structures over very short time scales. These compounds are ejected into the interstellar medium and distributed throughout the Galaxy. The structures of these compounds are similar to the insoluble organic matter found in meteorites. In this paper, we discuss to what extent stellar organics has enriched the primordial Solar System and possibly the early Earth.

  11. Extraterrestrial Organic Compounds in Meteorites

    NASA Technical Reports Server (NTRS)

    Botta, Oliver; Bada, Jeffrey L.; Meyer, Michael (Technical Monitor)

    2003-01-01

    Many organic compounds or their precursors found in meteorites originated in the interstellar or circumstellar medium and were later incorporated into planetesimals during the formation of the solar system. There they either survived intact or underwent further processing to synthesize secondary products on the meteorite parent body. The most distinct feature of CI and CM carbonaceous chondrites, two types of stony meteorites, is their high carbon content (up to 3% of weight), either in the form of carbonates or of organic compounds. The bulk of the organic carbon consists of an insoluble macromolecular material with a complex structure. Also present is a soluble organic fraction, which has been analyzed by several separation and analytical procedures. Low detection limits can be achieved by derivatization of the organic molecules with reagents that allow for analysis by gas chromatography/mass spectroscopy and high performance liquid chromatography. The CM meteorite Murchison has been found to contain more than 70 extraterrestrial amino acids and several other classes of compounds including carboxylic acids, hydroxy carboxylic acids, sulphonic and phosphonic acids, aliphatic, aromatic and polar hydrocarbons, fullerenes, heterocycles as well as carbonyl compounds, alcohols, amines and amides. The organic matter was found to be enriched in deuterium, and distinct organic compounds show isotopic enrichments of carbon and nitrogen relative to terrestrial matter.

  12. Extraterrestrial Organic Compounds in Meteorites

    NASA Technical Reports Server (NTRS)

    Botta, Oliver; Bada, Jeffrey L.; Meyer, Michael (Technical Monitor)

    2003-01-01

    Many organic compounds or their precursors found in meteorites originated in the interstellar or circumstellar medium and were later incorporated into planetesimals during the formation of the solar system. There they either survived intact or underwent further processing to synthesize secondary products on the meteorite parent body. The most distinct feature of CI and CM carbonaceous chondrites, two types of stony meteorites, is their high carbon content (up to 3% of weight), either in the form of carbonates or of organic compounds. The bulk of the organic carbon consists of an insoluble macromolecular material with a complex structure. Also present is a soluble organic fraction, which has been analyzed by several separation and analytical procedures. Low detection limits can be achieved by derivatization of the organic molecules with reagents that allow for analysis by gas chromatography/mass spectroscopy and high performance liquid chromatography. The CM meteorite Murchison has been found to contain more than 70 extraterrestrial amino acids and several other classes of compounds including carboxylic acids, hydroxy carboxylic acids, sulphonic and phosphonic acids, aliphatic, aromatic and polar hydrocarbons, fullerenes, heterocycles as well as carbonyl compounds, alcohols, amines and amides. The organic matter was found to be enriched in deuterium, and distinct organic compounds show isotopic enrichments of carbon and nitrogen relative to terrestrial matter.

  13. Hybrid membranes of metal-organic molecule nanocages for aromatic/aliphatic hydrocarbon separation by pervaporation.

    PubMed

    Zhao, Cui; Wang, Naixin; Wang, Lin; Huang, Hongliang; Zhang, Rong; Yang, Fan; Xie, Yabo; Ji, Shulan; Li, Jian-Rong

    2014-11-21

    Hybrid membranes composed of porous metal-organic molecule nanocages as fillers embedded in a hyperbranched polymer (Boltorn W3000) were fabricated, which exhibit excellent pervaporation separation performances towards aromatic/aliphatic hydrocarbons. The unique nature of the molecule-based fillers and their good dispersion and compatibility in/with the polymer are responsible for the good membrane properties.

  14. Pseudomonas sax genes overcome aliphatic isothiocyanate-mediated non-host resistance in Arabidopsis

    Treesearch

    Jun Fan; Casey Crooks; Gary Creissen; Lionel Hill; Shirley Fairhurst; Peter Doerner; Chris Lamb

    2011-01-01

    Most plant-microbe interactions do not result in disease; natural products restrict non-host pathogens. We found that sulforaphane (4-methylsulfinylbutyl isothiocyanate), a natural product derived from aliphatic glucosinolates, inhibits growth in Arabidopsis of non-host Pseudomonas bacteria in planta. Multiple sax genes (saxCAB/F/D/G) were identified in Pseudomonas...

  15. Catalytic conversion of aliphatic alcohols on carbon nanomaterials: The roles of structure and surface functional groups

    NASA Astrophysics Data System (ADS)

    Tveritinova, E. A.; Zhitnev, Yu. N.; Chernyak, S. A.; Arkhipova, E. A.; Savilov, S. V.; Lunin, V. V.

    2017-03-01

    Carbon nanomaterials with the structure of graphene and different compositions of the surface groups are used as catalysts for the conversion of C2-C4 aliphatic alcohols. The conversions of ethanol, propanol- 1, propanol-2, butanol-1, butanol-2, and tert-butanol on carbon nanotubes, nanoflakes, and nanoflakes doped with nitrogen are investigated. Oxidized and nonoxidized multiwalled carbon nanotubes, nanoflakes, and nanoflakes doped with nitrogen are synthesized. X-ray diffraction analysis, X-ray photoelectron spectroscopy, scanning and transmission electronic microscopies, Brunauer-Emmett-Teller method, derivatographic analyses, and the pulsed microcatalytic method are used to characterize comprehensively the prepared catalysts. It was established that all of the investigated carbon nanomaterials (with the exception of nondoped carbon nanoflakes) are bifunctional catalysts for the conversion of aliphatic alcohols, and promote dehydration reactions with the formation of olefins and dehydrogenation reactions with the formation of aldehydes or ketones. Nanoflakes doped with nitrogen are inert with respect to secondary alcohols and tert-butanol. The role of oxygen-containing and nitrogen-containing surface groups, and of the geometrical structure of the carbon matrix of graphene nanocarbon materials in the catalytic conversion of aliphatic alcohols, is revealed. Characteristics of the conversion of aliphatic alcohols that are associated with their structure are identified.

  16. Joint Test Protocol for Validation of Alternatives to Aliphatic Isocyanate Polyurethanes

    NASA Technical Reports Server (NTRS)

    Lewis, Pattie

    2005-01-01

    The primary objective of this effort is to demonstrate and validate alternatives to aliphatic isocyanate polyurethanes. Successful completion of this project will result in one or more isocyanate-free coatings qualified for use at AFSPC and NASA installations participating in this project.

  17. Decrease of aliphatic CHs from diatoms by in situ heating infrared microspectroscopy

    NASA Astrophysics Data System (ADS)

    Alipour, Leila; Nakashima, Satoru

    2016-04-01

    In situ heating IR microspectroscopy at 260-300°C under air and N2 conditions has been conducted on diatom frustules to examine aliphatic CH losses during heating, simulating their changes with burial-diagenesis. Assuming a reaction model made up of two first-order kinetic relations, reaction rate constants k1 and k2 and activation energies (Ea) were evaluated for aliphatic CHs. The rate constants for loss of aliphatic CHs of diatom frustules under air and N2 flow are much larger, with much smaller activation energies (57-109 kJ/mol: air; 14-44 kJ/mol: N2), than those for conventional hydrocarbon generation reactions from kerogens (170-370 kJ/mol) studied at higher temperatures (350-450°C). The CH decrease rates are somewhat different from the amide I decrease (protein degradation) rates. The obtained results suggest that organic transformation reactions including degradation of aliphatic CHs inside the diatom silica frustules might be quite different from those of kerogens separated from the biological structures.

  18. Modification of eucalyptus pulp fiber using silane coupling agents with aliphatic side chains of different length

    USDA-ARS?s Scientific Manuscript database

    The objective of this work was to evaluate the effect of three silane coupling agents with different aliphatic chain lengths on the hydrophobicity of eucalyptus pulp fiber. The three silanes coupling agents used (isobutyltrimethoxysilane, methyltrimethoxysilane, and n-octyltriethoxysilane [OTES]) we...

  19. SELECTIVE ENUMERATION OF AROMATIC AND ALIPHATIC HYDROCARBON DEGRADING BACTERIA BY A MOST-PROBABLE-NUMBER PROCEDURE

    EPA Science Inventory

    A most-portable-number (MPN) procedure was developed to separately enumerate aliphatic and aromatic hydrocarbon degrading bacteria, because most of the currently available methods are unable to distinguish between these two groups. Separate 96-well microtiter plates are used to ...

  20. Ruthenium/Imidazolylphosphine catalysis: hydrogenation of aliphatic and aromatic nitriles to form amines.

    PubMed

    Werkmeister, Svenja; Junge, Kathrin; Wendt, Bianca; Spannenberg, Anke; Jiao, Haijun; Bornschein, Christoph; Beller, Matthias

    2014-04-07

    A convenient and efficient catalyst system for the hydrogenation of aliphatic nitriles towards the corresponding primary amines in high to excellent yields is presented. In addition, aromatic nitriles are reduced smoothly, too. The use of low catalyst loadings and molecular hydrogen make this protocol an attractive methodology. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. SELECTIVE ENUMERATION OF AROMATIC AND ALIPHATIC HYDROCARBON DEGRADING BACTERIA BY A MOST-PROBABLE-NUMBER PROCEDURE

    EPA Science Inventory

    A most-portable-number (MPN) procedure was developed to separately enumerate aliphatic and aromatic hydrocarbon degrading bacteria, because most of the currently available methods are unable to distinguish between these two groups. Separate 96-well microtiter plates are used to ...

  2. PRECONCENTRATION OF ALIPHATIC AMINES FROM WATER DETERMINED BY CAPILLARY ELECTROPHORESIS WITH INDIRECT UV DETECTION

    EPA Science Inventory

    Preconcentration methodology based on adsorption chromatographies for enriching aliphatic amines (c1 to C4 substituted primary, secondary, and tertiary) and alkanolamines in water was studied by free zone capillary electrophoresis (CZE)with indirect UV detection. The solid-phase ...

  3. 40 CFR 721.530 - Substituted aliphatic acid halide (generic name).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.530 Substituted aliphatic acid halide (generic name). Link to an amendment published at 79 FR 34636, June 18, 2014. (a) Chemical substance and significant new uses...

  4. PRECONCENTRATION OF ALIPHATIC AMINES FROM WATER DETERMINED BY CAPILLARY ELECTROPHORESIS WITH INDIRECT UV DETECTION

    EPA Science Inventory

    Preconcentration methodology based on adsorption chromatographies for enriching aliphatic amines (c1 to C4 substituted primary, secondary, and tertiary) and alkanolamines in water was studied by free zone capillary electrophoresis (CZE)with indirect UV detection. The solid-phase ...

  5. One-pot synthesis of optically enriched 2-piperidinones from aliphatic aldehydes and cyanoacrylamides.

    PubMed

    He, Ying; Kang, Tai-Ran; Liu, Quan-Zhong; Chen, Lian-Mei; Tu, Yi-Lian; Liu, Ya-Jun; Chen, Tang-Bin; Wang, Zhi-Qiang; Liu, Jie; Xie, Yong-Mei; Yang, Jin-Liang; He, Long

    2013-08-16

    A highly stereoselective one-pot reaction of aliphatic aldehydes and cyanoacrylamides has been developed. The one-pot reaction includes an organocatalytic Michael addition followed by an intramolecular hemiaminalization. After reduction, optically enriched 2-piperidinones with three contiguous chiral centers were obtained in up to 95% yield and 9:1 dr with 99% ee.

  6. Mass spectral analysis of C3 and C4 aliphatic amino acid derivatives.

    NASA Technical Reports Server (NTRS)

    Lawless, J. G.; Chadha, M. S.

    1971-01-01

    Diagnostic criteria are obtained for the distinction of alpha, beta, gamma, and N-methyl isomers of the C3 and C4 aliphatic amino acids, using mass spectral analysis of the derivatives of these acids. The use of deuterium labeling has helped in the understanding of certain fragmentation pathways.

  7. 40 CFR 268.33 - Waste specific prohibitions-chlorinated aliphatic wastes.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... wastes, radioactive wastes mixed with these wastes, and soil and debris contaminated with radioactive... 40 Protection of Environment 26 2010-07-01 2010-07-01 false Waste specific prohibitions-chlorinated aliphatic wastes. 268.33 Section 268.33 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY...

  8. The carriers of the unidentified infrared emission features: Clues from polycyclic aromatic hydrocarbons with aliphatic sidegroups

    NASA Astrophysics Data System (ADS)

    Yang, X. J.; Glaser, R.; Li, Aigen; Zhong, J. X.

    2017-04-01

    The unidentified infrared emission (UIE) features at 3.3, 6.2, 7.7, 8.6, 11.3 and 12.7 μ m are ubiquitously seen in a wide variety of astrophysical regions in the Milky Way and nearby galaxies as well as distant galaxies at redshifts z ≳ 4. The UIE features are characteristic of the stretching and bending vibrations of aromatic hydrocarbon materials. The 3.3 μ m feature which results from the C-H stretching vibration in aromatic species is often accompanied by a weaker feature at 3.4 μ m. The 3.4 μ m feature is often thought to result from the C-H stretch of aliphatic groups attached to the aromatic systems. The ratio of the observed intensity of the 3.3 μ m aromatic C-H feature (I3.3) to that of the 3.4 μ m aliphatic C-H feature (I3.4) allows one to estimate the aliphatic fraction (e.g., NC, aliph/NC, arom, the number of C atoms in aliphatic units to that in aromatic rings) of the carriers of the UIE features, provided that the intrinsic oscillator strengths (per chemical bond) of the 3.3 μ m aromatic C-H stretch (A3.3) and the 3.4 μ m aliphatic C-H stretch (A3.4) are known. In this review we summarize the computational results on A3.3 and A3.4 and their implications for the aromaticity and aliphaticity of the UIE carriers. We use density functional theory and second-order perturbation theory to derive A3.3 and A3.4 from the infrared vibrational spectra of seven polycyclic aromatic hydrocarbon (PAH) molecules with various aliphatic substituents (e.g., methyl-, dimethyl-, ethyl-, propyl-, butyl-PAHs, and PAHs with unsaturated alkyl chains). The mean band strengths of the aromatic (A3.3) and aliphatic (A3.4) C-H stretches are derived and then employed to estimate the aliphatic fraction of the carriers of the UIE features by comparing the ratio of the intrinsic band strength of the two stretches (A3.4/A3.3) with the ratio of the observed intensities (I3.4/I3.3). We conclude that the UIE emitters are predominantly aromatic, as revealed by the observationally

  9. Degradation kinetics of chlorinated aliphatic hydrocarbons by methane oxidizers naturally-associated with wetland plant roots.

    PubMed

    Powell, C L; Goltz, M N; Agrawal, A

    2014-12-01

    Chlorinated aliphatic hydrocarbons (CAHs) are common groundwater contaminants that can be removed from the environment by natural attenuation processes. CAH biodegradation can occur in wetland environments by reductive dechlorination as well as oxidation pathways. In particular, CAH oxidation may occur in vegetated wetlands, by microorganisms that are naturally associated with the roots of wetland plants. The main objective of this study was to evaluate the cometabolic degradation kinetics of the CAHs, cis-1,2-dichloroethene (cisDCE), trichloroethene (TCE), and 1,1,1-trichloroethane (1,1,1TCA), by methane-oxidizing bacteria associated with the roots of a typical wetland plant in soil-free system. Laboratory microcosms with washed live roots investigated aerobic, cometabolic degradation of CAHs by the root-associated methane-oxidizing bacteria at initial aqueous [CH4] ~1.9mgL(-1), and initial aqueous [CAH] ~150μgL(-1); cisDCE and TCE (in the presence of 1,1,1TCA) degraded significantly, with a removal efficiency of approximately 90% and 46%, respectively. 1,1,1TCA degradation was not observed in the presence of active methane oxidizers. The pseudo first-order degradation rate-constants of TCE and cisDCE were 0.12±0.01 and 0.59±0.07d(-1), respectively, which are comparable to published values. However, their biomass-normalized degradation rate constants obtained in this study were significantly smaller than pure-culture studies, yet they were comparable to values reported for biofilm systems. The study suggests that CAH removal in wetland plant roots may be comparable to processes within biofilms. This has led us to speculate that the active biomass may be on the root surface as a biofilm. The cisDCE and TCE mass losses due to methane oxidizers in this study offer insight into the role of shallow, vegetated wetlands as an environmental sink for such xenobiotic compounds. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Distribution of aliphatic hydrocarbons, polycyclic aromatic hydrocarbons and organochlorinated pollutants in deep-sea sediments of the Southern Cretan margin, Eastern Mediterranean Sea: a baseline assessment.

    PubMed

    Mandalakis, Manolis; Polymenakou, Paraskevi N; Tselepides, Anastasios; Lampadariou, Nikolaos

    2014-07-01

    Deep sediments from the southern Cretan margin were analyzed to establish baseline levels for various types of organic pollutants before the anticipated intensification of anthropogenic activities. The total concentration of aliphatic hydrocarbons (ΣAH:326-3758ngg(-1), dry weight) was similar to those reported for deep sediments of the western Mediterranean Sea, while considerably lower levels were measured for polycyclic aromatic hydrocarbons (ΣPAH:9-60ngg(-1)). Source-diagnostic ratios suggested that the aliphatic hydrocarbons in sediments were mainly of terrestrial biogenic origin, while polycyclic aromatic hydrocarbons stemmed from the deposition of long-range transported combustion aerosols. Among the organochlorinated compounds analyzed, β-hexachlorocyclohexane (β-HCH:222-7052pgg(-1)), 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (p,p'-DDT:37-2236pgg(-1)) and polychlorinated biphenyls (ΣPCB:38-1182pgg(-1)) showed the highest abundance in sediments. The presence of HCHs and PCBs was attributed to historical inputs that have undergone extensive weathering, whereas an ongoing fresh input was suggested for p,p'-DDT. Multiple linear regression analysis revealed that the levels of the various pollutants in sediments were controlled by different factors, but with organic carbon content playing a prominent role in most cases. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. The difluoromethylene (CF2) group in aliphatic chains: Synthesis and conformational preference of palmitic acids and nonadecane containing CF2 groups.

    PubMed

    Wang, Yi; Callejo, Ricardo; Slawin, Alexandra M Z; O'Hagan, David

    2014-01-06

    The syntheses of palmitic acids and a nonadecane are reported with CF2 groups located 1,3 or 1,4 to each other along the aliphatic chain. Specifically 8,8,10,10- and 8,8,11,11-tetrafluorohexadecanoic acids (6b and 6c) are prepared as well as the singly modified analogue 8,8-difluorohexadecanoic acid (6a). Also 8,8,11,11-tetrafluorononadecane (27) is prepared as a pure hydrocarbon containing a 1,4-di-CF2 motif. The modified palmitic acids are characterized by differential scanning calorimetry (DSC) to determine melting points and phase behaviour relative to palmitic acid (62.5 °C). It emerges that 6c, with the CF2 groups placed 1,4- to each other, has a significantly higher melting point (89.9 °C) when compared to the other analogues and palmitic acid itself. It is a crystalline compound and the structure reveals an extended anti-zig-zag chain. Similarly 8,8,11,11-tetrafluorononadecane (27) adopts an extended anti-zig-zag structure. This is rationalized by dipolar relaxation between the two CF2 groups placed 1,4 to each other in the extended anti-zig-zag chain and suggests a design modification for long chain aliphatics which can introduce conformational stability.

  12. Unraveling the adsorption mechanism of aromatic and aliphatic diols on the TiO2 surface: a density functional theory analysis.

    PubMed

    Giorgi, Giacomo; Fujisawa, Jun-ichi; Segawa, Hiroshi; Yamashita, Koichi

    2013-06-28

    Understanding the adsorption mechanism of organic molecules on inorganic semiconductors is of great importance for generating and control functions in organic-inorganic materials. Here we have comprehensively investigated, by means of the density functional theory, the adsorption structure and energetic stability of aliphatic and aromatic diols on TiO2 using ethylene glycol, 1,2-n-decanediol, and catechol. Our calculations clearly show that the non-dissociative bidentate adsorption is more stable than the dissociative one for the aliphatic diol, both at low and high coverage conditions, result far differently from many other chemical anchor cases for which the dissociative mechanism usually prevails. On the other hand, for catechol the dissociative bidentate is the most stable at low coverage conditions, whereas, surprisingly, increasing the coverage with catechol makes the non-dissociative mechanism the most stable one, revealing possible coexistence of a dissociative and non-dissociative anchoring at high coverage. This work unraveled a variety of adsorption fashions of the diol compounds in conjunction with the impact of the coverage effect, highly dependent on the nature of the lateral chain of the anchor group.

  13. Novel use of aliphatic n-methyl ketones as a fumigant and alternative to methyl bromide for insect control.

    PubMed

    Zhu, Jiwei; Dhammi, Anirudh; van Kretschmar, Jaap B; Vargo, Edward L; Apperson, Charles S; Roe, R Michael

    2017-10-02

    Fumigants like phosphine, methyl bromide and sulfuryl fluoride are highly effective for the control of structural, storage and agricultural arthropod pests. Unfortunately, many of these synthetic compounds are highly toxic to people, many pests have developed resistance to these compounds, and methyl bromide, the "gold standard" for fumigants, was de-registered because of its depletion of the stratospheric ozone layer. Alternative fumigant chemistry is needed. Several plant species produce n-aliphatic methyl ketones to prevent plant herbivory. To examine the use of methyl ketones as a fumigant, structure-mortality studies were conducted using the red imported fire ant, Solenopsis invicta Buren, as a model. A new easy-to-use, inexpensive, and disposable bioassay system was developed for this work. The LC50 s for heptanone, octanone, nonanone and undecanone were 4.27, 5.11, 5.26 and 8.21 μg/cm(3) of ambient air, respectively. Although the former three methyl ketones were more effective than undecanone, subsequent research was conducted with 2-undecanone since this compound already has an US EPA registration as a biopesticide. In dose-response field studies, 12.4 ml of undecanone injected into mounds was the lowest application rate that produced no ant activity in the mound with no re-establishment of ants. Undecanone at reagent grade costs was more cost effective than methyl bromide for fire ants, adult German cockroaches and tobacco budworm eggs, but slightly more expensive for adult flour beetles. The naturally occurring methyl ketone, undecanone, has the potential to be an alternative to current fumigants for a variety of pest applications. This article is protected by copyright. All rights reserved.

  14. Neurotoxicity of organomercurial compounds.

    PubMed

    Sanfeliu, Coral; Sebastià, Jordi; Cristòfol, Rosa; Rodríguez-Farré, Eduard

    2003-01-01

    Mercury is a ubiquitous contaminant, and a range of chemical species is generated by human activity and natural environmental change. Elemental mercury and its inorganic and organic compounds have different toxic properties, but all them are considered hazardous in human exposure. In an equimolecular exposure basis, organomercurials with a short aliphatic chain are the most harmful compounds and they may cause irreversible damage to the nervous system. Methylmercury (CH(3)Hg(+)) is the most studied following the neurotoxic outbreaks identified as Minamata disease and the Iraq poisoning. The first description of the CNS pathology dates from 1954. Since then, the clinical neurology, the neuropathology and the mechanisms of neurotoxicity of organomercurials have been widely studied. The high thiol reactivity of CH(3)Hg(+), as well as all mercury compounds, has been suggested to be the basis of their harmful biological effects. However, there is clear selectivity of CH(3)Hg(+) for specific cell types and brain structures, which is not yet fully understood. The main mechanisms involved are inhibition of protein synthesis, microtubule disruption, increase of intracellular Ca(2+) with disturbance of neurotransmitter function, oxidative stress and triggering of excitotoxicity mechanisms. The effects are more damaging during CNS development, leading to alterations of the structure and functionality of the nervous system. The major source of CH(3)Hg(+) exposure is the consumption of fish and, therefore, its intake is practically unavoidable. The present concern is on the study of the effects of low level exposure to CH(3)Hg(+) on human neurodevelopment, with a view to establishing a safe daily intake. Recommendations are 0.4 micro g/kg body weight/day by the WHO and US FDA and, recently, 0.1 micro g/kg body weight/day by the US EPA. Unfortunately, these levels are easily attained with few meals of fish per week, depending on the source of the fish and its position in the

  15. Continuous Optical 3D Printing of Green Aliphatic Polyurethanes.

    PubMed

    Pyo, Sang-Hyun; Wang, Pengrui; Hwang, Henry H; Zhu, Wei; Warner, John; Chen, Shaochen

    2017-01-11

    Photosensitive diurethanes were prepared from a green chemistry synthesis pathway based on methacrylate-functionalized six-membered cyclic carbonate and biogenic amines. A continuous optical 3D printing method for the diurethanes was developed to create user-defined gradient stiffness and smooth complex surface microstructures in seconds. The green chemistry-derived polyurethane (gPU) showed high optical transparency, and we demonstrate the ability to tune the material stiffness of the printed structure along a gradient by controlling the exposure time and selecting various amine compounds. High-resolution 3D biomimetic structures with smooth curves and complex contours were printed using our gPU. High cell viability (over 95%) was demonstrated during cytocompatibility testing using C3H 10T1/2 cells seeded directly on the printed structures.

  16. Halogen, Hydroxy, Mercapto and Amino-Compounds: A Mechanistic Study--2

    ERIC Educational Resources Information Center

    Hanson, R. W.

    1976-01-01

    Compare reactions in which the functional groups of title compounds are displaced. The overall order of activity observed for alkyl halides, alcohols, thiels, and aliphatic amines acting as bases or nucleophiles is reversed when reactions involve displacement of the functional group. (MLH)

  17. Halogen, Hydroxy, Mercapto and Amino-Compounds: A Mechanistic Study--2

    ERIC Educational Resources Information Center

    Hanson, R. W.

    1976-01-01

    Compare reactions in which the functional groups of title compounds are displaced. The overall order of activity observed for alkyl halides, alcohols, thiels, and aliphatic amines acting as bases or nucleophiles is reversed when reactions involve displacement of the functional group. (MLH)

  18. Close Correlation between Heat Shock Response and Cytotoxicity in Neurospora crassa Treated with Aliphatic Alcohols and Phenols

    PubMed Central

    Meyer, U.; Schweim, P.; Fracella, F.; Rensing, L.

    1995-01-01

    In Neurospora crassa the aliphatic alcohols methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutanol, ethylene glycol, glycerol, and allyl alcohol and the phenolic compounds phenol, hydroquinone, resorcinol, pyrogallol, phloroglucinol, sodium salicylate, and acetylsalicylic acid were analyzed with respect to their capacities to induce heat shock proteins (HSP) and to inhibit protein synthesis. Both the alcohols and phenols showed the greatest levels of HSP induction at concentrations which inhibited the overall protein synthesis by about 50%. The abilities of the different alcohols to induce the heat shock response are proportional to their lipophilicities: the lipophilic alcohol isobutanol is maximally inductive at about 0.6 M, whereas the least lipophilic alcohol, methanol, causes maximal induction at 5.7 M. The phenols, in general, show a higher capability to induce the heat shock response. The concentrations for maximal induction range between 25 mM (sodium salicylate) and 100 mM (resorcinol). Glycerol (4.1 M) shifted the concentration necessary for maximal HSP induction by hydroquinone from 50 to 200 mM. The results reveal that the induction of HSP occurs under conditions which considerably constrain cell metabolism. The heat shock response, therefore, does not represent a sensitive marker for toxicity tests but provides a good estimate for the extent of cell damage. PMID:16534981

  19. Purification of Pseudomonas putida acyl coenzyme A ligase active with a range of aliphatic and aromatic substrates.

    PubMed Central

    Fernández-Valverde, M; Reglero, A; Martinez-Blanco, H; Luengo, J M

    1993-01-01

    Acyl coenzyme A (acyl-CoA) ligase (acyl-CoA synthetase [ACoAS]) from Pseudomonas putida U was purified to homogeneity (252-fold) after this bacterium was grown in a chemically defined medium containing octanoic acid as the sole carbon source. The enzyme, which has a mass of 67 kDa, showed maximal activity at 40 degrees C in 10 mM K2PO4H-NaPO4H2 buffer (pH 7.0) containing 20% (wt/vol) glycerol. Under these conditions, ACoAS showed hyperbolic behavior against acetate, CoA, and ATP; the Kms calculated for these substrates were 4.0, 0.7, and 5.2 mM, respectively. Acyl-CoA ligase recognizes several aliphatic molecules (acetic, propionic, butyric, valeric, hexanoic, heptanoic, and octanoic acids) as substrates, as well as some aromatic compounds (phenylacetic and phenoxyacetic acids). The broad substrate specificity of ACoAS from P. putida was confirmed by coupling it with acyl-CoA:6-aminopenicillanic acid acyltransferase from Penicillium chrysogenum to study the formation of several penicillins. Images PMID:8476289

  20. Visual determination of aliphatic diamines based on host-guest recognition of calix[4]arene derivatives capped gold nanoparticles.

    PubMed

    Chen, Yangyang; Zhang, Jiangjiang; Gao, Yanmin; Lee, Jaebeom; Chen, Hongxia; Yin, Yongmei

    2015-10-15

    Since amine compounds have been widespread pollutants in nature and they are extensively used in pharmaceutical industries and dye manufacturing, it is highly desirable to develop simple, effective and naked-eye available analytical methods for such aliphatic diamines determination. Calixarenes as macrocycles have drawn intensive interests for fields such as biomedicine, supramolecular chemistry and smart materials. Here, instead of the normal complicated modification strategy, a facile and efficient method for one-pot synthesis of calix[4]arene crown ether (CCE4) capped gold nanoparticles (AuNPs) is proposed. The as-prepared CCE4-AuNPs are not only high water dispersity and stability even after storage for 3 months, but also capable of host-guest recognition of diamines in aqueous systems. Size-selective encapsulation of amine group between CCE4 and diamines carry out the aggregation of CCE4-AuNPs. The determination of diamines such as hexamethylenediamine or spermine can be realized by the UV-vis absorbance change and visual color difference.

  1. Aliphatic and polycyclic aromatic hydrocarbons in surface sediments collected from mangroves with different levels of urbanization in southern Brazil.

    PubMed

    Assunção, Maíra Algarve; Frena, Morgana; Santos, Ana Paula Stein; Dos Santos Madureira, Luiz Augusto

    2017-06-15

    Three mangroves located in southern Brazil, Carijós (CA), Rio Tavares (RT) and Itacorubi (ITA), with distinct anthropogenic influences, were assessed with regard to the presence of aliphatic and polycyclic aromatic hydrocarbons (PAH). In this study, the n-alkane concentrations ranged from 1.9μg g(-1) (CA) to 55.6μg g(-1) (ITA) (dry weight). The carbon preference index (CPI) ranged from 2.1 to 7.9 and values for the terrestrial/aquatic ratio (TAR) were >1. Thus, both indexes indicated the predominance of sediment of terrestrial origin, mainly comprised of higher plants. Concentrations of total PAH ranged from 6.8ng g(-1) (RT) to 437.3ng g(-1) (ITA). The PAH isomeric ratios indicated that these compounds originated mainly from pyrogenic sources. Nevertheless, levels of n-alkanes in the three mangroves were relatively low and they are considered typical of uncontaminated surface sediments, while the level of contamination with PAH was classified as low to moderate. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Structure and properties of Al-MIL-53-ADP, a breathing MOF based on the aliphatic linker molecule adipic acid.

    PubMed

    Reinsch, Helge; Pillai, Renjith S; Siegel, Renée; Senker, Jürgen; Lieb, Alexandra; Maurin, Guillaume; Stock, Norbert

    2016-03-14

    The new aluminium based metal-organic framework [Al(OH)(O2C-C4H8-CO2)]·H2O denoted as Al-MIL-53-ADP-lp (lp stands for large pore) was synthesised under solvothermal conditions. This solid is an analogue of the archetypical aluminium terephthalate Al-MIL-53 based on the aliphatic single-chain linker molecule adipic acid (H2ADP, hexanedioic acid). In contrast to its aromatic counterparts, Al-MIL-53-ADP exhibits a structural breathing behaviour solely upon dehydration/rehydration. The crystal structure of the anhydrous compound denoted as Al-MIL-53-ADP-np (np stands for narrow pore) was determined by a combination of forcefield-based computations and Rietveld refinement of the powder X-ray diffraction data while the structure of the hydrated form Al-MIL-53-ADP-lp was derived computationally by a combination of force field based methods and Density Functional Theory calculations. Both structures were further supported by (1)H, (13)C and (27)Al high-resolution NMR MAS 1D data coupled again with simulations. Al-MIL-53-ADP was further characterised by means of vibrational spectroscopy, elemental analysis, thermogravimetry and water vapour sorption.

  3. Organic compounds in carbonaceous meteorites.

    PubMed

    Sephton, Mark A

    2002-06-01

    The carbonaceous chondrite meteorites are fragments of asteroids that have remained relatively unprocessed since the formation of the solar system 4.6 billion years ago. These carbon-rich objects contain a variety of extraterrestrial organic molecules that constitute a record of chemical evolution prior to the origin of life. Compound classes include aliphatic hydrocarbons, aromatic hydrocarbons, amino acids, carboxylic acids, sulfonic acids, phosphonic acids, alcohols, aldehydes, ketones, sugars, amines, amides, nitrogen heterocycles, sulfur heterocycles and a relatively abundant high molecular weight macromolecular material. Structural and stable isotopic characteristics suggest that a number of environments may have contributed to the organic inventory, including interstellar space, the solar nebula and the asteroidal meteorite parent body. This review covers work published between 1950 and the present day and cites 193 references.

  4. Biodegradability of nitrogenous compounds under anaerobic conditions and its estimation.

    PubMed

    Hongwei, Yang; Zhanpeng, Jiang; Shaoqi, Shi

    2006-02-01

    The anaerobic biodegradability of 23 nitrogenous compounds, including nitrogenous heterocyclic compounds and aliphatic amines, was tested and assessed in integration. These nitrogenous compounds were classified into readily, partially, and poorly biodegradable compounds after calculation of their integrated assessment indices (IAIs), Rules for anaerobic biodegradation of these compounds were also drawn. Stepwise regression and backpropagation artificial neural network (BP-ANN) methods were applied to establish quantitative structure-biodegradability relationships (QSBRs) based on the assessment results. In QSBR models, three molecular structure descriptors-second-order molecular connectivity index (2chi(V3)chi(v)p), and energy of the highest occupied molecular orbital (EHOMO)--were included. After analysis of the sensitivity of variables in QSBR models, it was found that the key molecular structure descriptor affecting anaerobic biodegradability of nitrogenous compounds is EHOMO, which is directly proportional to the anaerobic biodegradability of nitrogenous compounds.

  5. Skin exposure to aliphatic polyisocyanates in the auto body repair and refinishing industry: II. A quantitative assessment.

    PubMed

    Bello, Dhimiter; Redlich, Carrie A; Stowe, Meredith H; Sparer, Judy; Woskie, Susan R; Streicher, Robert P; Hosgood, H Dean; Liu, Youcheng

    2008-03-01

    Skin exposure to isocyanates, in addition to respiratory exposures, may contribute to sensitization and asthma. Quantitative skin exposure data are scarce and quantitative methods limited. As part of the Survey of Painters and Repairers of Autobodies by Yale study, a method to sample and quantify human isocyanate skin exposure was developed (based on NIOSH 5525 method) and used to evaluate aliphatic isocyanate skin exposure in 81 auto body shop painters and body technicians. Wipe samples were collected from unprotected skin and from under PPE (gloves, clothing and respirator) using a polypropylene glycol-impregnated wipe. Hexamethylene diisocyanate (HDI), its polyisocyanates [HDI-derived polyisocyanates (pHDI)], isophorone diisocyanate (IPDI) and its polyisocyanates and IPDI-derived polyisocyanates (pIPDI) were quantified separately and also expressed as the total free isocyanate groups (total NCO). For unprotected skin areas, 49 samples were collected for spray painting, 13 for mixing, 27 for paint-related tasks (e.g. sanding and compounding) and 53 for non-paint-related tasks. Forty-three samples were also collected under PPE. The geometric mean (GM) [geometric standard deviation (GSD)] total NCO concentrations (ng NCO cm(-2)) for unprotected skin (hands, face and forearms) was 1.9 (10.9) and range 0.0-64.4. pHDI species were the major contributor to the total NCO content. Levels were very variable, with the highest concentrations measured for clear coating and paint mixing tasks. Isocyanate skin exposure was also commonly detected under PPE, with 92% of samples above the limit of detection. Levels were very variable with the overall GM (GSD) total NCO (ng NCO cm(-2)) under PPE 1.0 (5.2) and range (0.0-47.0) and similar under the different PPE (glove, respirator and clothing). The highest concentrations were detected for mixing and spraying tasks, 6.9 (5.3) and 1.0 (5.2), respectively. Levels under PPE were generally lower than unpaired samples obtained with no

  6. Biodegradation of the (aliphatic + aromatic) fraction of Oural crude oil. Biomarker identification using GC/MS SIM and GC/MS/MS.

    PubMed

    Jacquot, F; Doumenq, P; Guiliano, M; Munoz, D; Guichard, J R; Mille, G

    1996-03-01

    A simplified fraction of the Oural crude oil (aliphatic and aromatic hydrocarbons) was incubated in the presence of an hydrocarbonoclastic bacterial community isolated from a marine sediment highly contaminated by petroleum residue. The biodegradation has been carried out under aerobic conditions for 5 weeks and followed by FTIR, UV synchronous luminescence and GC/FID. Disappearance of the n-alkanes (2nd week), an important attack of the isoprenoïd compounds (5th week) and preferential alteration of monomethylated polyaromatics were observed. Concerning the biomarkers, the bicyclic alkanes and pentacyclic terpanes have been comparatively elucidated using GC/MS data. The identification of C(26) to C(29) steranes has required a most selective method, namely GC/MS/MS. Many molecular ratios based on GC/MS abundances were calculated, which showed good stability. Consequently, they can be used to determine the origin of a petroleum even one altered by biodegradation.

  7. Syntheses of two new hybrid metal-organic polymers using flexible aliphatic dicarboxylates and pyrazine: Crystal structures and magnetic studies

    NASA Astrophysics Data System (ADS)

    Zhang, Chang-Zheng; Mao, Hong-Yan; Wang, Yan-Li; Zhang, Hong-Yun; Tao, Jing-Cao

    2007-02-01

    The reaction of metal ions, flexible aliphatic dicarboxylates and pyrazine in aqueous solution afford two new metal-organic coordination polymers, {[Cu2(μ2-η2-O2C(CH2)2CO2-η2-μ2)2(H2O)2]·2H2O}n (1) and [Eu2(μ2-η2-O2CCH2CO2-η1-μ1)2(μ2-η2-O2CCH2CO2-η2-μ2)(H2O)6]n (2). Polymer 1 contains the paddle-wheel cage dicopper(II) units, forming a one-dimensional (1D) double-stranded chain structure along the a-axis, in which the copper(II) atoms are bridged by the carboxylate groups of four succinates. The intradimer Cu Cu distance is 2.613(2) Å; the interdimer Cu⋯Cu distance is 6.473 Å. To our knowledge, compound 1 represents the first example of a double-stranded chain structure containing dinuclear paddle-wheel type cage. In the three-dimensional (3D) compound 2, each central Eu(III) ion have a distorted monocapped square antiprism coordination geometry. The structure is built up from two types of polymeric chains with [EuO6(H2O)3]n units as tethers, resulting in microporous framework. The magnetic behavior of 1 shows that the occurrence of a strong antiferromagnetic coupling between the copper(II) ions through the short bridges via the carboxyl groups can be obtained; the best fittings to the experimental magnetic susceptibilities gave -2J=314 cm-1.

  8. Application of polymethacrylate resin as stationary phase in liquid chromatography with UV detection for C1-C7 aliphatic monocarboxylic acids and C1-C7 aliphatic monoamines.

    PubMed

    Ohta, Kazutoku; Towata, Atsuya; Ohashi, Masayoshi; Takeuchi, Toyohide

    2004-06-11

    The application of unfunctionized polymethacrylate resin (TSKgel G3000PWXL) as a stationary phase in liquid chromatography with UV detection for C1-C7 aliphatic monocarboxylic acids (formic acid, acetic acid, propionic acid, butyric acid, isovaleric acid, valeric acid, 3,3-dimethylbutyric acid, 4-methylvaleric acid, hexanoic acid, 2-methylhexanoic acid, 5-methylhexanoic acid and heptanoic acid) and C1-C7 aliphatic monoamines (methylamine, ethylamine, propylamine, isobutylamine, butylamine, isoamylamine, amylamine, 1,3-dimethylbutylamine, hexylamine, 2-heptylamine and heptylamine) was carried out. Using dilute sulfuric acid as the eluent, the TSKgel G3000PWXL, resin acted as an advanced stationary phase for these C1-C7 carboxylic acids. Excellent simultaneous separation and symmetrical peaks for these C1-C7 carboxylic acids were achieved on a TSKgel G3000PWXL column (150 mm x 6 mm i.d.) in 60 min with 0.25 mM sulfuric acid containing 1 mM 2-methylheptanoic acid at pH 3.3 as the eluent. Using dilute sodium hydroxide as the eluent, the TSKgel G3000PWXL resin also behaved as an advanced stationary phase for these C1-C7 amines. Excellent simultaneous separation and good peaks for these C1-C7 amines were achieved on the TSKgel G3000PWXL column in 60 min with 10 mM sodium hydroxide containing 0.5 mM 1-methylheptylamine at pH 11.9 as the eluent.

  9. The ozonolysis of primary aliphatic amines in fine particles

    NASA Astrophysics Data System (ADS)

    Zahardis, J.; Geddes, S.; Petrucci, G. A.

    2008-02-01

    The oxidative processing by ozone of the particulate amines octadecylamine (ODA) and hexadecylamine (HDA) is reported. Ozonolysis of these amines resulted in strong NO2- and NO3- ion signals that increased with ozone exposure as monitored by photoelectron resonance capture ionization aerosol mass spectrometry. These products suggest a mechanism of progressive oxidation of the particulate amines to nitroalkanes. Additionally, a strong ion signal at 125 m/z is assigned to the ion NO3- (HNO3). For ozonized mixed particles containing ODA or HDA + oleic acid (OL), with pO3≥3×10-7 atm, imine, secondary amide, and tertiary amide products were measured. These products most likely arise from reactions of amines with aldehydes (for imines) and stabilized Criegee intermediates (SCI) or secondary ozonides (for amides) from the fatty acid. The routes to amides via SCI and/or secondary ozonides were shown to be more important than comparable amide forming reactions between amines and organic acids, using azelaic acid as a test compound. Finally, direct evidence is provided for the formation of a surface barrier in the ODA + OL reaction system that resulted in the retention of OL at high ozone exposures (up to 10-3 atm for 17 s). This effect was not observed in HDA + OL or single component OL particles, suggesting that it may be a species-specific surfactant effect from an in situ generated amide or imine. Implications to tropospheric chemistry, including particle bound amines as sources of oxidized gas phase nitrogen species (e.g.~NO2, NO3), formation of nitrogen enriched HULIS via ozonolysis of amines and source apportionment are discussed.

  10. Quantification of sterols and aliphatic alcohols in Mediterranean stone pine (Pinus pinea L.) populations.

    PubMed

    Nasri, Nizar; Fady, Bruno; Triki, Saïda

    2007-03-21

    Individual components of Pinus pinea L. oil unsaponifiable matter isolated from seven Mediterranean populations were identified and quantified. P. pinea oil unsaponifiable matter contained very high levels of phytosterols (>or=4298 mg kg-1 of total extracted lipids), of which beta-sitosterol was the most abundant (74%). Aliphatic alcohol contents were 1365 mg kg-1 of total extracted lipids, of which octacosanol was the most abundant (41%). Two alcohols (hexacosanol and octacosanol), which are usually absent in common vegetable oils, were described for P. pinea oils. There were almost no differences in the total unsaponifiable matter of the seven Mediterranean populations studied. However, sterol and aliphatic alcohol contents showed some variability, with Tunisian and Moroccan populations showing very different and higher contents.

  11. Spacecraft Maximum Allowable Concentrations (SMACs) for C3 to C8 Aliphatic Saturated Aldehydes

    NASA Technical Reports Server (NTRS)

    Langford, Shannon D.

    2007-01-01

    Spacecraft maximum allowable concentrations (SMACs) for C3 to C8, straight-chain, aliphatic aldehydes have been previously assessed and have been documented in volume 4 of Spacecraft Maximum Allowable Concentrations for Selected Airborne Contaminants (James, 2000). These aldehydes as well as associated physical properties are shown in Table 1. The C3 to C8 aliphatic aldehydes can enter the habitable compartments and contaminate breathing air of spacecraft by several routes including incomplete oxidation of alcohols in the Environmental Control and Life Support System (ECLSS) air revitalization subsystem, as a byproduct of human metabolism, through materials off-gassing, or during food preparation. These aldehydes have been detected in the atmosphere of manned space vehicles in the past. Analysis performed by NASA of crew cabin air samples from the Russian Mir Space Station revealed the presence of C3 to C8 aldehydes at concentrations peaking at approximately 0.1 mg/cu m.

  12. [Synthesis, characterization and fluorescent properties of copper phthalocyanine derivates substituted by aliphatic alcohol].

    PubMed

    Zhang, Liang; Xu, Qing-Feng; Lu, Jian-Mei; Yao, She-Chun

    2007-04-01

    A series of copper phthalocyanine derivatives substituted by aliphatic chain were obtained by the reaction of tetra-formyl chloride copper phthalocyanine and aliphatic alcohol such as n-butyl alcohol, n-amyl alcohol, n-hexyl alcohol, n-caprylic alcohol and lauryl alcohol. IR, UV-Vis, elemental analysis and 1H NMR verified the structures and substituting degree. The solubility and the relationship between fluorescence and concentration and substituting group were studied in organic solution. It was confirmed that the solubility in organic solution was improved greatly, the fluorescence did not change in linear according to the concentration and the fluorescence of copper phthalocyanine derivatives substituted by the long alkyl was stronger than that substituted by the relatively short alkyl.

  13. Biodegradation of aliphatic hydrocarbons in the presence of hydroxy cucurbit[6]uril.

    PubMed

    Pasumarthi, Rajesh; Kumar, Vikash; Chandrasekharan, Sivaraman; Ganguly, Anasuya; Banerjee, Mainak; Mutnuri, Srikanth

    2014-11-15

    Aliphatic hydrocarbons are one of the major environmental pollutants with reduced bioavailability. The present study focuses on the effect of hydroxy cucurbit[6]uril on the bioavailability of hydrocarbons. A bacterial consortium was used for biodegradation studies under saline and non-saline conditions. Based on denaturing gradient gel electrophoresis results it was found that the consortium under saline conditions had two different strains. The experiment was conducted in microcosms with tetradecane, hexadecane, octadecane and mixture of the mentioned hydrocarbons as the sole carbon source. The residual hydrocarbon was quantified using gas chromatography every 24h. It was found that biodegradation of tetradecane and hexadecane, as individual carbon source increased in the presence of hydroxy CB[6], probably due to the increase in their bioavailability. In case of octadecane this did not happen. Bioavailability of all three aliphatic hydrocarbons was increased when provided as a mixture to the consortium under saline conditions. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. A general catalytic β-C-H carbonylation of aliphatic amines to β-lactams.

    PubMed

    Willcox, Darren; Chappell, Ben G N; Hogg, Kirsten F; Calleja, Jonas; Smalley, Adam P; Gaunt, Matthew J

    2016-11-18

    Methods for the synthesis and functionalization of amines are intrinsically important to a variety of chemical applications. We present a general carbon-hydrogen bond activation process that combines readily available aliphatic amines and the feedstock gas carbon monoxide to form synthetically versatile value-added amide products. The operationally straightforward palladium-catalyzed process exploits a distinct reaction pathway, wherein a sterically hindered carboxylate ligand orchestrates an amine attack on a palladium anhydride to transform aliphatic amines into β-lactams. The reaction is successful with a wide range of secondary amines and can be used as a late-stage functionalization tactic to deliver advanced, highly functionalized amine products of utility for pharmaceutical research and other areas. Copyright © 2016, American Association for the Advancement of Science.

  15. Aliphatic polyester polymer stars: synthesis, properties and applications in biomedicine and nanotechnology.

    PubMed

    Cameron, Donald J A; Shaver, Michael P

    2011-03-01

    A critical review: the ring-opening polymerization of cyclic esters provides access to an array of biodegradable, bioassimilable and renewable polymeric materials. Building these aliphatic polyester polymers into larger macromolecular frameworks provides further control over polymer characteristics and opens up unique applications. Polymer stars, where multiple arms radiate from a single core molecule, have found particular utility in the areas of drug delivery and nanotechnology. A challenge in this field is in understanding the impact of altering synthetic variables on polymer properties. We review the synthesis and characterization of aliphatic polyester polymer stars, focusing on polymers originating from lactide, ε-caprolactone, glycolide, β-butyrolactone and trimethylene carbonate monomers and their copolymers including coverage of polyester miktoarm star copolymers. These macromolecular materials are further categorized by core molecules, catalysts employed, self-assembly and degradation properties and the resulting fields of application (262 references).

  16. Mild Aliphatic and Benzylic Hydrocarbon C-H Bond Chlorination Using Trichloroisocyanuric Acid.

    PubMed

    Combe, Sascha H; Hosseini, Abolfazl; Parra, Alejandro; Schreiner, Peter R

    2017-03-03

    We present the controlled monochlorination of aliphatic and benzylic hydrocarbons with only 1 equiv of substrate at 25-30 °C using N-hydroxyphthalimide (NHPI) as radical initiator and commercially available trichloroisocyanuric acid (TCCA) as the chlorine source. Catalytic amounts of CBr4 reduced the reaction times considerably due to the formation of chain-carrying ·CBr3 radicals. Benzylic C-H chlorination affords moderate to good yields for arenes carrying electron-withdrawing (50-85%) or weakly electron-donating groups (31-73%); cyclic aliphatic substrates provide low yields (24-38%). The products could be synthesized on a gram scale followed by simple purification via distillation. We report the first direct side-chain chlorination of 3-methylbenzoate affording methyl 3-(chloromethyl)benzoate, which is an important building block for the synthesis of vasodilator taprostene.

  17. Cyclo-Aliphatic Epoxide Based Photo Cured Gelled Electrolytes for Secondary Li Battery Applications. Electrochemical Kinetic Studies

    NASA Technical Reports Server (NTRS)

    Nagasubramanian, G.; Surampudi, S.; Halpert, G.

    1993-01-01

    Cyclo aliphatic epoxide based thin gelled fils prepared by UV photo curing were characterized electrochemically. Thylene carbonate (EC) mixed with different organic liquids in different volume ratios were used as solvents.

  18. DETERMINATION OF ALIPHATIC AMINES IN WATER USING DERIVATIZATION WITH FLUORESCEIN ISOTHIOCYANATE AND CAPILLARY ELECTROPHORESIS/LASER-INDUCED FLUORESCENCE DETECTION.

    EPA Science Inventory

    Detection-oriented derivatization of aliphatic amines and amine functional groups in coumpounds of environmental interest was studied using fluorescein isothiocyanate (FITC) with separation/determination by capillary electrophoresis/laser-induced fluorescence. Determinative level...

  19. Coefficients of caffeine distribution in aliphatic alcohol-ammonium sulfate-water systems

    NASA Astrophysics Data System (ADS)

    Korenman, Ya. I.; Krivosheeva, O. A.; Mokshina, N. Ya.

    2012-11-01

    The extraction of caffeine with aliphatic alcohols C3-C9 from aqueous solutions in the presence of a salting-out agent (ammonium sulfate) is studied. Quantitative characteristics of extraction are calculated: the distribution coefficients ( D) and the degree of recovery ( R, %). Relations are found between log D of caffeine and the length of the hydrocarbon radical in the alcohol molecule, along with certain physicochemical properties of the extragents.

  20. Gas phase heterogeneous catalytic oxidation of alkanes to aliphatic ketones and/or other oxygenates

    DOEpatents

    Lin, Manhua; Wang, Xiang; Yeom, Younghoon

    2015-09-29

    A catalyst, its method of preparation and its use for producing aliphatic ketones by subjecting alkanes C.sub.3 to C.sub.9 to a gas phase catalytic oxidation in the presence of air or oxygen, and, optionally, steam and/or one or more diluting gases. The catalyst comprises a catalytically active mixed metal oxide phase and a suitable support material onto and/or into which the active catalytic phase is dispersed.

  1. Gas phase heterogeneous catalytic oxidation of alkanes to aliphatic ketones and/or other oxygenates

    DOEpatents

    Lin, Manhua; Wang, Xiang; Yeom, Younghoon

    2015-03-17

    A catalyst, its method of preparation and its use for producing aliphatic ketones by subjecting alkanes C.sub.3 to C.sub.9 to a gas phase catalytic oxidation in the presence of air or oxygen, and, optionally, steam and/or one or more diluting gases. The catalyst comprises a catalytically active mixed metal oxide phase and a suitable support material onto and/or into which the active catalytic phase id dispersed.

  2. Triphosgene-Pyridine Mediated Stereoselective Chlorination of Acyclic Aliphatic 1,3-Diols†

    PubMed Central

    Villalpando, Andrés; Saputra, Mirza A.; Tugwell, Thomas H.; Kartika, Rendy

    2015-01-01

    We describe a strategy to chlorinate stereocomplementary acyclic aliphatic 1,3-diols using a mixture of triphosgene and pyridine. While 1,3-anti diols readily led to 1,3-anti dichlorides, 1,3-syn diols must be converted to 1,3-syn diol monosilylethers to access the corresponding 1,3-syn dichlorides. These dichlorination protocols were operationally simple, very mild, and readily tolerated by advanced synthetic intermediates. PMID:26323232

  3. Anomalous Energy Effects in some Aliphatic and Alicyclic Aza Systems and their Nitro Derivatives

    DTIC Science & Technology

    1990-03-01

    AUJTHOR(a) 8. CONTRACT OR GRANT NUMBER(-) Jane S. Murray, Paul C. Redfern, Jorge M. Seminario and Peter Politzer N00014-85-K-0217 It) .PERFORMING...Anomalous Energy Effects in Some Aliphatic and Alicyclic Aza Systems and Their Nitro Derivatives Jane S. Murray, Paul C. Redfern, Jorge M. Seminario , and...3801. (25) Politzer. P.: Jayasuriya, K.; Zilles, B. A. J. Am. Chem. Soc. 1985, (20) Murray, J. S.; Seminario . J. M.; Politzer, P. Unpublished work

  4. [Comparative study of bacterial agmatinase inhibition by derivatives of putrescine and aliphatic monoamines].

    PubMed

    Khramov, V A

    1977-03-01

    Aliphatic monoamines and some putrescine derivatives (10(-3) M) are found to inhibit agmatinase from Proteus vulgaris. Constants and the type of inhibition are determined. Investigation of the temperature effect on the inhibition has revealed an exotermic character of this process. Some thermodinamic parameters of agmatinase-anylamine binding reaction are calculated. 1-Guanidobutane is obtained by means of 1-amidobutane guanidilation, and it is found to be more efficient inhibitor than monoamines.

  5. SPITZER'S VIEW ON AROMATIC AND ALIPHATIC HYDROCARBON EMISSION IN HERBIG Ae STARS

    SciTech Connect

    Acke, B.; Waters, L. B. F. M.; Bouwman, J.; Juhasz, A.; Henning, Th.; Van den Ancker, M. E.; Meeus, G.; Tielens, A. G. G. M.

    2010-07-20

    The chemistry of astronomical hydrocarbons, responsible for the well-known infrared emission features detected in a wide variety of targets, remains enigmatic. Here we focus on the group of young intermediate-mass Herbig Ae stars. We have analyzed the aliphatic and polycyclic aromatic hydrocarbon (PAH) emission features in the infrared spectra of a sample of 53 Herbig Ae stars, obtained with the Infrared Spectrograph aboard the Spitzer Space Telescope. We confirm that the PAH-to-stellar luminosity ratio is higher in targets with a flared dust disk. However, a few sources with a flattened dust disk still show relatively strong PAH emission. Since PAH molecules trace the gas disk, this indicates that gas disks may still be flared, while the dust disk has settled due to grain growth. There are indications that the strength of the 11.3 {mu}m feature also depends on dust disk structure, with flattened disks being less bright in this feature. We confirm that the CC bond features at 6.2 and 7.8 {mu}m shift to redder wavelengths with decreasing stellar effective temperature. Moreover, we show that this redshift is accompanied by a relative increase of aliphatic CH emission and a decrease of the aromatic 8.6 {mu}m CH feature strength. Cool stars in our sample are surrounded by hydrocarbons with a high aliphatic/aromatic CH ratio and a low aromatic CH/CC ratio, and vice versa for the hot stars. We conclude that, while the overall hydrocarbon emission strength depends on the dust disk's geometry, the relative differences seen in the IR emission features in disks around Herbig Ae stars are mainly due to chemical differences of the hydrocarbon molecules induced by the stellar UV field. Strong UV flux reduces the aliphatic component and emphasizes the spectral signature of the aromatic molecules in the IR spectra.

  6. Approach to the study of C-glycosyl flavones acylated with aliphatic and aromatic acids from Spergularia rubra by high-performance liquid chromatography-photodiode array detection/electrospray ionization multi-stage mass spectrometry.

    PubMed

    Ferreres, Federico; Gil-Izquierdo, Angel; Vinholes, Juliana; Grosso, Clara; Valentão, Patrícia; Andrade, Paula B

    2011-03-30

    The use of mass spectrometry (MS) coupled to liquid chromatography (LC) as working tool for the study of the C-glycosyl flavones acylated with aliphatic and aromatic acids has allowed the tentative characterization of these compounds in Spergularia rubra and the establishment of the position of the acylation on the sugar moiety of the C-glycosylation by use of MS data. The combination of retention time (Rt), ultraviolet (UV) and MS(n) data of the compounds revealed their C-glycosyl flavone nature, being luteolin, apigenin and chrysoeriol derivatives. Ten non-acylated flavones were identified, from which six are described for the first time (one 7-O-glycosyl-6,8-diC-glycosyl flavone, four 6,8-diC-glycosyl flavones and one 2"-O-glycosyl-6-C-glycosyl flavone). Twenty-six acylated derivatives were also found for the first time. These compounds are grouped in three classes, namely, C-glycosyl flavones acylated with aliphatic acids, with aromatic acids or with a mixed acylation. The first group is characterized by the presence of one 6,8-diC-(acetyl)glycosyl flavone, four 6,8-diC-(malonyl)glycosyl flavones and two 7-O-glycosyl-6,8-diC-(malonyl)glycosyl flavones, while in the second one twelve 6,8-diC-(acyl)glycosyl flavones and two 7-O-glycosyl-6,8-diC-(acyl)glycosyl flavones are described. The last class contained five 6,8-diC-(malonyl,acyl)glycosyl flavones. No previous work has described the presence of C-glycosyl flavones acylated with aliphatic acids in this genus.

  7. The influence of chemical composition of aliphatic-aromatic copolyesters on their properties

    NASA Astrophysics Data System (ADS)

    Wojtczak, Malgorzata; Galeski, Andrzej; Dutkiewicz, Slawomir; Piorkowska, Ewa

    2014-05-01

    The chain microstructure and properties of a series of aliphatic-aromatic copolyesters in a range of compositions from 10 to 100% of aromatic components were studied by examining melting and crystallization behaviors, dynamic mechanical response, morphology, wide- (WAXS) and small-angle X-ray scattering (SAXS), and tensile deformation. Chain microstructure was analyzed by 1H NMR. The results indicate that most of copolyesters used in this study have essentially random distribution of comonomers. Copolyesters with more than 30 mol% of aromatic part crystallize with a crystal structure characteristic for homopolymer poly(butylene terephthalate) (PBT). However, some of the reflections from crystal planes are shifted towards lower diffraction angles as compared to butylene terephthalate homoplymer. The phase transition temperatures decrease with increasing aliphatic content. By means of polarized light microscopy (PLM), small-angle light scattering (SALS) and SAXS, crystallization behavior of a selected aliphatic-aromatic copolyester was further explored. Selected copolyester crystallizes in the form of thin fibrous crystals, few nanometers thick, which is the main factor influencing the depression of its melting temperature.

  8. The influence of chemical composition of aliphatic-aromatic copolyesters on their properties

    SciTech Connect

    Wojtczak, Malgorzata; Galeski, Andrzej; Piorkowska, Ewa; Dutkiewicz, Slawomir

    2014-05-15

    The chain microstructure and properties of a series of aliphatic-aromatic copolyesters in a range of compositions from 10 to 100% of aromatic components were studied by examining melting and crystallization behaviors, dynamic mechanical response, morphology, wide- (WAXS) and small-angle X-ray scattering (SAXS), and tensile deformation. Chain microstructure was analyzed by {sup 1}H NMR. The results indicate that most of copolyesters used in this study have essentially random distribution of comonomers. Copolyesters with more than 30 mol% of aromatic part crystallize with a crystal structure characteristic for homopolymer poly(butylene terephthalate) (PBT). However, some of the reflections from crystal planes are shifted towards lower diffraction angles as compared to butylene terephthalate homoplymer. The phase transition temperatures decrease with increasing aliphatic content. By means of polarized light microscopy (PLM), small-angle light scattering (SALS) and SAXS, crystallization behavior of a selected aliphatic-aromatic copolyester was further explored. Selected copolyester crystallizes in the form of thin fibrous crystals, few nanometers thick, which is the main factor influencing the depression of its melting temperature.

  9. Kinetics of aerobic cometabolic biodegradation of chlorinated and brominated aliphatic hydrocarbons: A review.

    PubMed

    Jesus, João; Frascari, Dario; Pozdniakova, Tatiana; Danko, Anthony S

    2016-05-15

    This review analyses kinetic studies of aerobic cometabolism (AC) of halogenated aliphatic hydrocarbons (HAHs) from 2001-2015 in order to (i) compare the different kinetic models proposed, (ii) analyse the estimated model parameters with a focus on novel HAHs and the identification of general trends, and (iii) identify further research needs. The results of this analysis show that aerobic cometabolism can degrade a wide range of HAHs, including HAHs that were not previously tested such as chlorinated propanes, highly chlorinated ethanes and brominated methanes and ethanes. The degree of chlorine mineralization was very high for the chlorinated HAHs. Bromine mineralization was not determined for studies with brominated aliphatics. The examined research period led to the identification of novel growth substrates of potentially high interest. Decreasing performance of aerobic cometabolism were found with increasing chlorination, indicating the high potential of aerobic cometabolism in the presence of medium- and low-halogenated HAHs. Further research is needed for the AC of brominated aliphatic hydrocarbons, the potential for biofilm aerobic cometabolism processes, HAH-HAH mutual inhibition and the identification of the enzymes responsible for each aerobic cometabolism process. Lastly, some indications for a possible standardization of future kinetic studies of HAH aerobic cometabolism are provided.

  10. Novel synthetic method for the preparation of amphiphilic hyaluronan by means of aliphatic aromatic anhydrides.

    PubMed

    Huerta-Angeles, Gloria; Bobek, Martin; Příkopová, Eva; Šmejkalová, Daniela; Velebný, Vladimír

    2014-10-13

    The present work describes a novel and efficient method of synthesis of amphiphilic hyaluronan (HA) by esterification with alkyl fatty acids. These derivatives were synthesized under mild aqueous and well controlled conditions using mixed aliphatic aromatic anhydrides. These anhydrides characterized by the general formula RCOOCOC6H2Cl3 can be easily prepared by the reaction of the corresponding fatty acid (R) with 2,4,6-trichlorobenzoyl chloride (TCBC) in the presence of triethylamine. The aliphatic aromatic anhydrides RCOOCOC6H2Cl3 then react with the polysaccharide and enable the synthesis of aliphatic acid esters of HA in good yields. No hydrolytic degradation of hyaluronic acid could be observed. Parameters controlling the degree of esterification were systematically studied. Fatty acids with different chain lengths can be introduced applying this methodology. The degree of substitution was decreasing with increasing length of hydrophobic chain. The reaction products were fully characterized by Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR), SEC-MALLS and chromatographic analyses. Although the esterified HA products exhibited aggregation in solution as demonstrated by NMR, microscopy and rheology, they were still water-soluble.

  11. A study of aliphatic amino acids using simulated vibrational circular dichroism and Raman optical activity spectra*

    NASA Astrophysics Data System (ADS)

    Ganesan, Aravindhan; Brunger, Michael J.; Wang, Feng

    2013-11-01

    Vibrational optical activity (VOA) spectra, such as vibrational circular dichroism (VCD) and Raman optical activity (ROA) spectra, of aliphatic amino acids are simulated using density functional theory (DFT) methods in both gas phase (neutral form) and solution (zwitterionic form), together with their respective infrared (IR) and Raman spectra of the amino acids. The DFT models, which are validated by excellent agreements with the available experimental Raman and ROA spectra of alanine in solution, are employed to study other aliphatic amino acids. The inferred (IR) intensive region (below 2000 cm-1) reveals the signature of alkyl side chains, whereas the Raman intensive region (above 3000 cm-1) contains the information of the functional groups in the amino acids. Furthermore, the chiral carbons of the amino acids (except for glycine) dominate the VCD and ROA spectra in the gas phase, but the methyl group vibrations produce stronger VCD and ROA signals in solution. The C-H related asymmetric vibrations dominate the VOA spectra (i.e., VCD and ROA) > 3000 cm-1 reflecting the side chain structures of the amino acids. Finally the carboxyl and the C(2)H modes of aliphatic amino acids, together with the side chain vibrations, are very active in the VCD/IR and ROA/Raman spectra, which makes such the vibrational spectroscopic methods a very attractive means to study biomolecules.

  12. Olfactory discrimination ability for aliphatic esters in squirrel monkeys and humans.

    PubMed

    Laska, M; Freyer, D

    1997-08-01

    Using a behavioral paradigm designed to simulate olfactory-guided foraging, the ability of five squirrel monkeys to distinguish iso-amyl acetate from n- and iso-forms of other acetic esters (ethyl acetate to decyl acetate) and from other esters carrying the iso-amyl group (iso-amyl propionate to iso-amyl capronate) was investigated. We found (i) that all five animals were clearly able to discriminate between all odor pairs tested; (ii) a significant negative correlation between discrimination performance and structural similarity of odorants in terms of differences in carbon chain length of both the aliphatic alcohol group and the aliphatic acid group of the esters; and (iii) that iso- and n-amyl acetate were perceived as qualitatively similar despite different steric conformation. Using a triple-forced choice procedure, 20 human subjects were tested on the same tasks in parallel and showed a very similar pattern of discrimination performance compared with the squirrel monkeys. Thus, the results of this study provide evidence of well-developed olfactory discrimination ability in squirrel monkeys for aliphatic esters and support the assumption that human and non-human primates may share common principles of odor quality perception.

  13. Exploring mild enzymatic sustainable routes for the synthesis of bio-degradable aromatic-aliphatic oligoesters.

    PubMed

    Pellis, Alessandro; Guarneri, Alice; Brandauer, Martin; Acero, Enrique Herrero; Peerlings, Henricus; Gardossi, Lucia; Guebitz, Georg M

    2016-05-01

    The application of Candida antarctica lipase B in enzyme-catalyzed synthesis of aromatic-aliphatic oligoesters is here reported. The aim of the present study is to systematically investigate the most favorable conditions for the enzyme catalyzed synthesis of aromatic-aliphatic oligomers using commercially available monomers. Reaction conditions and enzyme selectivity for polymerization of various commercially available monomers were considered using different inactivated/activated aromatic monomers combined with linear polyols ranging from C2 to C12 . The effect of various reaction solvents in enzymatic polymerization was assessed and toluene allowed to achieve the highest conversions for the reaction of dimethyl isophthalate with 1,4-butanediol and with 1,10-decanediol (88 and 87% monomer conversion respectively). Mw as high as 1512 Da was obtained from the reaction of dimethyl isophthalate with 1,10-decanediol. The obtained oligomers have potential applications as raw materials in personal and home care formulations, for the production of aliphatic-aromatic block co-polymers or can be further functionalized with various moieties for a subsequent photo- or radical polymerization.

  14. A laboratory investigation of the effectiveness of various skin and surface decontaminants for aliphatic polyisocyanates.

    PubMed

    Bello, Dhimiter; Woskie, Susan R; Streicher, Robert P; Stowe, Meredith H; Sparer, Judy; Redlich, Carrie A; Cullen, Mark R; Liu, Youcheng

    2005-07-01

    Isocyanates may cause contact dermatitis and respiratory sensitization leading to asthma. Dermal exposure to aliphatic isocyanates in auto body shops is very common. However, little is known about the effectiveness of available commercial products used for decontaminating aliphatic polyisocyanates. This experimental study evaluated the decontamination effectiveness of aliphatic polyisocyanates for several skin and surface decontaminants available for use in the auto body industry. The efficiency of two major decontamination mechanisms, namely (i) consumption of free isocyanate groups via chemical reactions with active hydrogen components of the decontaminant and (ii) physical removal processes such as dissolution were studied separately for each decontaminant. Considerable differences were observed among surface decontaminants in their rate of isocyanate consumption, of which those containing free amine groups performed the best. Overall, Pine-Sol(R) MEA containing monoethanolamine was the most efficient surface decontaminant, operating primarily via chemical reaction with the isocyanate group. Polypropylene glycol (PPG) had the highest physical removal efficiency and the lowest reaction rate with isocyanates. All tested skin decontaminants performed similarly, accomplishing decontamination primarily via physical processes and removing 70-80% of isocyanates in one wiping. Limitations of these skin decontaminants are discussed and alternatives presented. In vitro testing using animal skins and in vivo testing with field workers are being conducted to further assess the efficiency and identify related determinants.

  15. The effect of mechanical loads on the degradation of aliphatic biodegradable polyesters.

    PubMed

    Li, Ying; Chu, Zhaowei; Li, Xiaoming; Ding, Xili; Guo, Meng; Zhao, Haoran; Yao, Jie; Wang, Lizhen; Cai, Qiang; Fan, Yubo

    2017-06-01

    Aliphatic biodegradable polyesters have been the most widely used synthetic polymers for developing biodegradable devices as alternatives for the currently used permanent medical devices. The performances during biodegradation process play crucial roles for final realization of their functions. Because physiological and biochemical environment in vivo significantly affects biodegradation process, large numbers of studies on effects of mechanical loads on the degradation of aliphatic biodegradable polyesters have been launched during last decades. In this review article, we discussed the mechanism of biodegradation and several different mechanical loads that have been reported to affect the biodegradation process. Other physiological and biochemical factors related to mechanical loads were also discussed. The mechanical load could change the conformational strain energy and morphology to weaken the stability of the polymer. Besides, the load and pattern could accelerate the loss of intrinsic mechanical properties of polymers. This indicated that investigations into effects of mechanical loads on the degradation should be indispensable. More combination condition of mechanical loads and multiple factors should be considered in order to keep the degradation rate controllable and evaluate the degradation process in vivo accurately. Only then can the degradable devise achieve the desired effects and further expand the special applications of aliphatic biodegradable polyesters.

  16. The effect of mechanical loads on the degradation of aliphatic biodegradable polyesters

    PubMed Central

    Li, Ying; Chu, Zhaowei; Li, Xiaoming; Ding, Xili; Guo, Meng; Zhao, Haoran; Yao, Jie; Wang, Lizhen; Cai, Qiang

    2017-01-01

    Abstract Aliphatic biodegradable polyesters have been the most widely used synthetic polymers for developing biodegradable devices as alternatives for the currently used permanent medical devices. The performances during biodegradation process play crucial roles for final realization of their functions. Because physiological and biochemical environment in vivo significantly affects biodegradation process, large numbers of studies on effects of mechanical loads on the degradation of aliphatic biodegradable polyesters have been launched during last decades. In this review article, we discussed the mechanism of biodegradation and several different mechanical loads that have been reported to affect the biodegradation process. Other physiological and biochemical factors related to mechanical loads were also discussed. The mechanical load could change the conformational strain energy and morphology to weaken the stability of the polymer. Besides, the load and pattern could accelerate the loss of intrinsic mechanical properties of polymers. This indicated that investigations into effects of mechanical loads on the degradation should be indispensable. More combination condition of mechanical loads and multiple factors should be considered in order to keep the degradation rate controllable and evaluate the degradation process in vivo accurately. Only then can the degradable devise achieve the desired effects and further expand the special applications of aliphatic biodegradable polyesters. PMID:28596915

  17. REFINING FLUORINATED COMPOUNDS

    DOEpatents

    Linch, A.L.

    1963-01-01

    This invention relates to the method of refining a liquid perfluorinated hydrocarbon oil containing fluorocarbons from 12 to 28 carbon atoms per molecule by distilling between 150 deg C and 300 deg C at 10 mm Hg absolute pressure. The perfluorinated oil is washed with a chlorinated lower aliphatic hydrocarbon, which mairtains a separate liquid phase when mixed with the oil. Impurities detrimental to the stability of the oil are extracted by the chlorinated lower aliphatic hydrocarbon. (AEC)

  18. Biodegradation of halogenated organic compounds.

    PubMed Central

    Chaudhry, G R; Chapalamadugu, S

    1991-01-01

    In this review we discuss the degradation of chlorinated hydrocarbons by microorganisms, emphasizing the physiological, biochemical, and genetic basis of the biodegradation of aliphatic, aromatic, and polycyclic compounds. Many environmentally important xenobiotics are halogenated, especially chlorinated. These compounds are manufactured and used as pesticides, plasticizers, paint and printing-ink components, adhesives, flame retardants, hydraulic and heat transfer fluids, refrigerants, solvents, additives for cutting oils, and textile auxiliaries. The hazardous chemicals enter the environment through production, commercial application, and waste. As a result of bioaccumulation in the food chain and groundwater contamination, they pose public health problems because many of them are toxic, mutagenic, or carcinogenic. Although synthetic chemicals are usually recalcitrant to biodegradation, microorganisms have evolved an extensive range of enzymes, pathways, and control mechanisms that are responsible for catabolism of a wide variety of such compounds. Thus, such biological degradation can be exploited to alleviate environmental pollution problems. The pathways by which a given compound is degraded are determined by the physical, chemical, and microbiological aspects of a particular environment. By understanding the genetic basis of catabolism of xenobiotics, it is possible to improve the efficacy of naturally occurring microorganisms or construct new microorganisms capable of degrading pollutants in soil and aquatic environments more efficiently. Recently a number of genes whose enzyme products have a broader substrate specificity for the degradation of aromatic compounds have been cloned and attempts have been made to construct gene cassettes or synthetic operons comprising these degradative genes. Such gene cassettes or operons can be transferred into suitable microbial hosts for extending and custom designing the pathways for rapid degradation of recalcitrant

  19. Hydrophobic Compounds Reshape Membrane Domains

    PubMed Central

    Barnoud, Jonathan; Rossi, Giulia; Marrink, Siewert J.; Monticelli, Luca

    2014-01-01

    Cell membranes have a complex lateral organization featuring domains with distinct composition, also known as rafts, which play an essential role in cellular processes such as signal transduction and protein trafficking. In vivo, perturbations of membrane domains (e.g., by drugs or lipophilic compounds) have major effects on the activity of raft-associated proteins and on signaling pathways, but they are difficult to characterize because of the small size of the domains, typically below optical resolution. Model membranes, instead, can show macroscopic phase separation between liquid-ordered and liquid-disordered domains, and they are often used to investigate the driving forces of membrane lateral organization. Studies in model membranes have shown that some lipophilic compounds perturb membrane domains, but it is not clear which chemical and physical properties determine domain perturbation. The mechanisms of domain stabilization and destabilization are also unknown. Here we describe the effect of six simple hydrophobic compounds on the lateral organization of phase-separated model membranes consisting of saturated and unsaturated phospholipids and cholesterol. Using molecular simulations, we identify two groups of molecules with distinct behavior: aliphatic compounds promote lipid mixing by distributing at the interface between liquid-ordered and liquid-disordered domains; aromatic compounds, instead, stabilize phase separation by partitioning into liquid-disordered domains and excluding cholesterol from the disordered domains. We predict that relatively small concentrations of hydrophobic species can have a broad impact on domain stability in model systems, which suggests possible mechanisms of action for hydrophobic compounds in vivo. PMID:25299598

  20. Membrane-Mediated Extraction and Biodegradation of Volatile Organic Compounds From Air

    DTIC Science & Technology

    2005-01-01

    degraders for compounds found in MilSpec paints; specifically m-xylene, p-xylene, ethylbenzene, butyl acetate, butanol , MEK and acetone . 4.2.1.1...ethylbenzene, butanol , butyl acetate, and acetone . 4.2.1.2. Xylene Degraders The first of these studies involved the screening of MX and X1 for growth on... butanol , butyl acetate, MEK, and acetone . This was done to select the better aliphatic- compound degrader of the two strains for the staged biotreatment

  1. A New, Rapid, Precise and Sensitive Method for Chlorine Stable Isotope Analysis of Chlorinated Aliphatic Hydrocarbons

    NASA Astrophysics Data System (ADS)

    van Acker, M. R.; Shahar, A.; Young, E. D.; Coleman, M. L.

    2005-12-01

    Chlorinated aliphatic hydrocarbons (CAH) are recognized common groundwater contaminants. Because of their physico-chemical properties, their lifespan in groundwater is in the order of decades (Pankow and Cherry, 1996). Stable isotopes can play a role in determining the rate and extent of CAH attenuation (Slater, 2003). The use of chlorine has been hampered by the current time consuming and insensitive analytical methods. We present a new analytical procedure to measure chlorine stable isotope values using a gas chromatograph coupled to a multi-collector inductively coupled mass spectrometer (GC-MC-ICP-MS). The GC has a Porapack Q packed column. The carrier gas was helium and the temperature was constant at 160°C. The GC was coupled to the MC-ICP-MS by heated stainless steel tubing. Our high resolution spectra showed that 37Cl is free of its main interference 36Ar-H over a range of 0.004 amu. Two pure CAH, trichloroethene (TCE) and tetrachloroethene (PCE), were used for zero enrichment (sample relative to itself) and standard-sample difference measurements. Integrations and background corrections of transient signals were performed using Microsoft Excel after import of the raw data from the MC-ICPMS acquisition software. Zero enrichment tests with TCE and PCE yielded δ37Cl of -0.04±0.16‰ and -0.03±0.17‰, respectively, results for sample injections of 0.12 to 0.02 microliters. Accuracy was tested by injecting 0.24 microliters of a 50/50 mixture of TCE and PCE of known isotopic compositions as the difference between the two solvents was of paramount interest. The δ37Cl(TCE) value of PCE was -1.99±0.16‰. A highly satisfactory comparison with the conventional method is shown by published values for TCE and PCE, -2.04±0.12‰ and -0.30±0.14‰, respectively (Jendrzejewski et al., 2001), giving a δ37Cl(TCE) value for PCE of -2.34±0.18‰. These tests of the GC-MC-ICP-MS method showed that we can obtain reproducible and accurate Cl isotope values using an

  2. Photocatalytic transformations of organic sulfur compounds and H2S

    NASA Astrophysics Data System (ADS)

    Vorontsov, A. V.

    2008-10-01

    Modern views on the products, pathways and kinetic features of liquid- and gas-phase photocatalytic reactions of sulfur compounds in the presence of heterogeneous and homogeneous photocatalysts are generalised. Attention is focussed on the aliphatic and aromatic reduced sulfur compounds and pesticides. The reaction rate in the liquid and gas phases are analysed as function of solution pH, temperature, catalyst content, substrate concentration, solvent type, air moisture and added oxidants. Photocatalyst deactivation and the ways for recovery of its activity are considered.

  3. Thermodynamic properties of organic iodine compounds

    NASA Astrophysics Data System (ADS)

    Richard, Laurent; Gaona, Xavier

    2011-11-01

    A critical evaluation has been made of the thermodynamic properties reported in the literature for 43 organic iodine compounds in the solid, liquid, or ideal gas state. These compounds include aliphatic, cyclic and aromatic iodides, iodophenols, iodocarboxylic acids, and acetyl and benzoyl iodides. The evaluation has been made on the basis of carbon number systematics and group additivity relations, which also allowed to provide estimates of the thermodynamic properties of those compounds for which no experimental data were available. Standard molal thermodynamic properties at 25 °C and 1 bar and heat capacity coefficients are reported for 13 crystalline, 29 liquid, and 39 ideal gas organic iodine compounds, which can be used to calculate the corresponding properties as a function of temperature and pressure. Values derived for the standard molal Gibbs energy of formation at 25 °C and 1 bar of these crystalline, liquid, and ideal gas organic iodine compounds have subsequently been combined with either solubility measurements or gas/water partition coefficients to obtain values for the standard partial molal Gibbs energies of formation at 25 °C and 1 bar of 32 aqueous organic iodine compounds. The thermodynamic properties of organic iodine compounds calculated in the present study can be used together with those for aqueous inorganic iodine species to predict the organic/inorganic speciation of iodine in marine sediments and petroleum systems, or in the near- and far-field of nuclear waste repositories.

  4. Biodegradable compounds: Rheological, mechanical and thermal properties

    NASA Astrophysics Data System (ADS)

    Nobile, Maria Rossella; Lucia, G.; Santella, M.; Malinconico, M.; Cerruti, P.; Pantani, R.

    2015-12-01

    Recently great attention from industry has been focused on biodegradable polyesters derived from renewable resources. In particular, PLA has attracted great interest due to its high strength and high modulus and a good biocompatibility, however its brittleness and low heat distortion temperature (HDT) restrict its wide application. On the other hand, Poly(butylene succinate) (PBS) is a biodegradable polymer with a low tensile modulus but characterized by a high flexibility, excellent impact strength, good thermal and chemical resistance. In this work the two aliphatic biodegradable polyesters PBS and PLA were selected with the aim to obtain a biodegradable material for the industry of plastic cups and plates. PBS was also blended with a thermoplastic starch. Talc was also added to the compounds because of its low cost and its effectiveness in increasing the modulus and the HDT of polymers. The compounds were obtained by melt compounding in a single screw extruder and the rheological, mechanical and thermal properties were investigated. The properties of the two compounds were compared and it was found that the values of the tensile modulus and elongation at break measured for the PBS/PLA/Talc compound make it interesting for the production of disposable plates and cups. In terms of thermal resistance the compounds have HDTs high enough to contain hot food or beverages. The PLA/PBS/Talc compound can be, then, considered as biodegradable substitute for polystyrene for the production of disposable plates and cups for hot food and beverages.

  5. Aliphatic side chains of proteins as potential geomarkers of NOM liberated from the melting permafrost and discharged to the Arctic Ocean by the Kolyma River run off

    NASA Astrophysics Data System (ADS)

    Dubinenkov, I. V.; Perminova, I.; Kononikhin, A.; Nikolaev, E.; Hertkorn, N.; Bulygina, E. B.; Holmes, R. M.

    2011-12-01

    The Arctic ecosystem is highly sensitive to climate change. Global warming might have considerable effects on regional carbon cycling due to permafrost melting. Permafrost in the Arctic region represents an extremely large organic carbon reservoir mostly stored in the permafrost. Mobilization of just a small portion of carbon stored in Arctic soils will have considerable impacts on the flux of organic carbon from land to the Arctic Ocean, which can affect the Arctic environment. The Kolyma River watershed is one of the Arctic Ocean's largest. It is dominated by continuous permafrost which is underlain with rich organic soils susceptible to increased fluvial transport. The goal of the work was to analyze the structure of isolated natural organic matter from different fresh water environments of the Kolyma river basin. NOM was isolated from the Kolyma River main stream, its tributaries, a thermokarst lake, a floodplain stream and the permafrost. Solid phase extraction technique was used with Bond Elute PPL cartridges. Nuclear magnetic resonance spectroscopy (NMR) and Fourier Transform Ion Cyclotron Resonance Mass Spectroscopy (FTICRMS) was used for structural studies because of unsurpassed molecular level structural information provided by these high resolution magnetic resonance techniques. The NOM samples from the Kolyma River showed high contents of non-substituted aliphatic structures with a low content of aromatics and carbohydrates. Aliphatic nature may indicate a microbial source of NOM in the form of degraded terpenoids and hopanols. It was shown that almost all NOM samples from the rivers had similar molecular composition enriched with aliphatic units. The samples from permafrost mud streams were significantly different and contained sharp peptide signatures. In general, permafrost NOM contained much less degraded peptide residuest as compared to riverine samples. Identification of these residues showed the presence of branched amino acids (valine, alanine

  6. TRIFLUOROMETHYL COMPOUNDS OF GERMANIUM

    DTIC Science & Technology

    FLUORIDES, *GERMANIUM COMPOUNDS, *HALIDES, *ORGANOMETALLIC COMPOUNDS, ALKYL RADICALS, ARSENIC COMPOUNDS, CHEMICAL BONDS, CHEMICAL REACTIONS ...CHLORIDES, CHLORINE COMPOUNDS, HYDROLYSIS, IODIDES, METHYL RADICALS, POTASSIUM COMPOUNDS, PYROLYSIS, STABILITY, SYNTHESIS, TIN COMPOUNDS.

  7. Homoeologous GSL-ELONG gene replacement for manipulation of aliphatic glucosinolates in Brassica rapa L. by marker assisted selection

    PubMed Central

    Hirani, Arvind H.; Zelmer, Carla D.; McVetty, Peter B. E.; Daayf, Fouad; Li, Genyi

    2013-01-01

    Aliphatic glucosinolates are the predominant sulfur-rich plant secondary metabolites in economically important Brassica crops. Glucosinolates and their hydrolysis products are involved in plant–microbe, plant–insect, plant–animal, and plant–human interactions. It is, therefore, important to manipulate glucosinolate profiles and contents in Brassica species. In this study, aliphatic glucosinolates were genetically manipulated through homoeologous recombination in backcross lines followed by marker assisted selection in B. rapa. A resynthesized B. napus line, from a cross between B. rapa and B. oleracea, was backcrossed with Chinese cabbage doubled haploid line, RI16. Marker assisted selection for non-functional gene was performed in each backcross generations. Advanced backcross progenies (BC3F2) were developed to identify homoeologous gene replacement and/or introgression. Reduction in 5C aliphatic glucosinolates (gluconapoleiferin, glucoalyssin, and glucobrassicanapin) was observed in BC3F2 progenies of the recurrent parent that carried the GSL-ELONG- gene. The GSL-ELONG- positive backcross progenies were also screened by the A-genome and BraGSL-ELONG gene specific marker, which linked with 5C aliphatic glucosinolates. The A-genome specific marker was absent in the plants of advanced backcross progenies which showed reduction in 5C aliphatic glucosinolates. The results suggest that the functional allele had been replaced by the non-functional GSL-ELONG- allele from B. oleracea. Some advanced backcross progenies (BC3F2) positive for the GSL-ELONG- allele and the A-genome specific SCAR marker BraMAM1-1 did not show reduction in 5C aliphatic glucosinolates, suggesting that GSL-ELONG- allele is recessive. Replacement of the functional locus in the A-genome by non-functional counterpart in the C-genome reduced the content of 5C aliphatic glucosinolates in B. rapa seeds with 20 μmol/g. PMID:23532458

  8. Characterization of High Explosives and Other Energetic Compounds by Computational Chemistry and Molecular Modeling: Experiments for Undergraduate Curriculum

    ERIC Educational Resources Information Center

    Bumpus, John A.; Lewis, Anne; Stotts, Corey; Cramer, Christopher J.

    2007-01-01

    Experiments suited for the undergraduate instructional laboratory in which the heats of formation of several aliphatic and aromatic compounds are calculated, are described. The experiments could be used to introduce students to commercially available computational chemistry and its thermodynamics, while assess and compare the energy content of…

  9. Characterization of High Explosives and Other Energetic Compounds by Computational Chemistry and Molecular Modeling: Experiments for Undergraduate Curriculum

    ERIC Educational Resources Information Center

    Bumpus, John A.; Lewis, Anne; Stotts, Corey; Cramer, Christopher J.

    2007-01-01

    Experiments suited for the undergraduate instructional laboratory in which the heats of formation of several aliphatic and aromatic compounds are calculated, are described. The experiments could be used to introduce students to commercially available computational chemistry and its thermodynamics, while assess and compare the energy content of…

  10. Oxidation-Responsive Aliphatic Polycarbonates from N-Substituted Eight-Membered Cyclic Carbonate: Synthesis and Degradation Study.

    PubMed

    Qiu, Fang-Yi; Yu, Li; Du, Fu-Sheng; Li, Zi-Chen

    2017-08-24

    Oxidation-responsive aliphatic polycarbonates represent a promising branch of functional biodegradable polymers. This paper reports the synthesis and ring-opening polymerization (ROP) of an eight-membered cyclic carbonate possessing phenylboronic pinacol ester (C3) and the H2 O2 -triggered degradation of its polymer (PC3). C3 is prepared from the inexpensive and readily available diethanolamine with a moderate yield and undergoes the well-controlled anionic ROP with a living character under catalysis of 1,8-diazabicyclo[5.4.0]undec-7-ene. It can also be copolymerized with l-lactide, trimethylene carbonate, and 5-ter-butyloxycarbonylamino trimethylene carbonate, affording the copolymers with a varied distribution of the repeating units. To clearly demonstrate the oxidative degradation mechanism of PC3, this paper first investigates the H2 O2 -induced decomposition of small-molecule model compounds by proton nuclear magnetic resonance ((1) H NMR). It is found that the adduct products formed by the in-situ-generated secondary amines and p-quinone methide (QM) are thermodynamically unstable and can decompose slowly back to QM and the amines. On this basis, this paper further studies the H2 O2 -accelerated degradation of PC3 nanoparticles that are prepared by the o/w emulsion method. A sequential process of oxidation of the phenylboronic ester, 1,6-elimination of the in-situ-generated phenol, releasing CO2 and intramolecular cyclization or isomerization is proposed as the degradation mechanism of PC3. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. In vitro evaluation of aliphatic fatty alcohol metabolites of Perseaamericana seed as potential antimalarial and antimicrobial agents

    PubMed Central

    Falodun, A.; Erharuyi, O.; Imieje, V.; Ahomafor, J.; Akunyuli, C.; Jacobs, M.; Khan, S.; Hamann, M. T.; Langer, P.

    2016-01-01

    Perseaamericana Mill (Lauraceae) is a local medicinal plant used in Nigerian ethnomedicine as antimalarial. The aqueous decoction of the root part is a potent remedy against bacterial infections. Hence, the need to investigate the phytochemical and biological activities (antimicrobial and antiplasmodial) of the root back of Perseaamericana. Chromatographic and spectroscopic techniques were used in the identification and purification of metabolites, which were assayed for antimalarial and antimicrobial activities using Plasmodium falciparum and a panel of microorganisms. From the seeds of P. americana, five known 1, 2, 4-dihydroxy derivatives aliphatic alcohols, called avocadenols were isolated and identified by spectroscopic methods including 1D- and 2D NMR, and comparison with reported data in literature. Antifungal activity for 1, 2, 4-Trihydroxyheptadec-6-en-16-yne (5) (IC50< 8 μg/mL) against all the fungal strains and S. areus, and antimalarial activity for compounds 1, 2, 4-Trihydroxyheptadec-16-ene (1) and 1, 2, 4-tetrahydroxyheptadecane-6, 16-diene(2) (IC50 = 1.6 and 1.4 μg/mL for the D6 clone, respectively, and 2.1 and 1.4 μg/mL for the W2 clone, respectively) was observed. The fatty alcohols 1, 2, 4-tetrahydroxyheptadecane-6, 16-diene(2); 1, 2, 4-Trihydroxyheptadec-16-yne(3) and 1, 2, 4-Trihydroxyheptadecane(4) also exhibited promising in vitro antibacterial activity against a panel of pathogenic bacteria S. areus, methicillin resistant S. areus and E. coli at IC50 values of 21.1, 8, 200 μg/mL), (3.259, 86.32 μg/mL) and (17.18, 8.26 and 200 μg/mL), respectively. The results of this study provide evidence that the fatty alcohols are a promising class of antimalarial and antimicrobial agents. PMID:28042193

  12. Metabolism of the Aliphatic Nitramine 4-Nitro-2,4-Diazabutanal by Methylobacterium sp. Strain JS178

    PubMed Central

    Fournier, Diane; Trott, Sandra; Hawari, Jalal; Spain, Jim

    2005-01-01

    The aliphatic nitramine 4-nitro-2,4-diazabutanal (NDAB; C2H5N3O3) is a ring cleavage metabolite that accumulates during the aerobic degradation of the energetic compound hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) by various Rhodococcus spp. NDAB is also produced during the alkaline hydrolysis of either RDX or octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) and during the photolysis of RDX. Traces of NDAB were observed in a soil sampled from an ammunition-manufacturing facility contaminated with both HMX and RDX, suggesting natural attenuation. In this study, we report the isolation of a soil bacterium that is able to degrade NDAB under aerobic conditions. The isolate is a pink-pigmented facultative methylotroph affiliated with the genus Methylobacterium. The strain, named Methylobacterium sp. strain JS178, degrades NDAB as a sole nitrogen source, with concomitant growth and formation of 1 molar equivalent of nitrous oxide (N2O). Comparison of the growth yield of strain JS178 grown on NDAB, nitrite (NO2−), or ammonium (NH4+) as a nitrogen source revealed that 1 N equivalent is assimilated from each mole of NDAB, which completes the nitrogen mass balance. In radiotracer experiments, strain JS178 mineralized 1 C of the [14C]NDAB produced in situ from [14C]RDX by Rhodococcus sp. strain DN22. Studies on the regulation of NDAB degradation indicated that allantoin, an intermediate in the purine catabolic pathway and a central molecule in the storage and transport of nitrogen in plants, up-regulated the enzyme(s) involved in the degradation of the nitramine. The results reveal the potential for the sequential participation of rhodococci and methylobacteria to effect the complete degradation of RDX. PMID:16085803

  13. Application of ultrasound to enhance the zero-valent iron-initiated abiotic degradation of halogenated aliphatic compounds

    NASA Astrophysics Data System (ADS)

    Ruiz, Nancy Elaine

    Permeable iron barriers, while effective as a near-passive in situ remediation technology for halogenated organic solvents, are susceptible to the loss of reactivity over time, most probably due to a build up of corrosion products or other precipitates on the iron surface. If such material can be removed, a barrier's lifetime can be significantly extended. This proof-of-concept project employed ultrasonic energy to rejuvenate an iron surface. Through batch studies, iron's capacity to degrade dissolved chlorinated solvents under various conditions before and after sonication was examined. The impact of iron pretreatment, groundwater quality, and sonication and the nature of the deposits formed on iron during solvent degradation were determined in order to evaluate the physical mechanism of ultrasonic enhancement of iron and to develop guidelines for barrier design and an ultrasound delivery system for a future field study. Iron (coarse filings, 100-mesh powder, or foamed pellets) placed in deoxygenated natural groundwater was exposed to 330 W-hr of ultrasonic energy prior to the introduction of trichloroethylene (TCE). The iron was also subjected to various pretreatments to create surface conditions with differing rates of activity for chlorinated solvent degradation. Aqueous concentrations of TCE and any degradation products were monitored over time. Geochemical modeling indicated that an iron barrier in this water would be subject to heavy precipitation of carbonates and hydroxides. Sonication positively impacted iron's degradation of chlorinated solvents, probably most directly linked to an increase in active specific surface area, achieved by removing deposits and/or etching the surface, as suggested by scanning electron micrographs. X-Ray photoelectron spectroscopy (XPS) analysis indicated that sonication also changes the chemical composition of the outermost 40 Angstroms of an iron surface. For some degraded irons, activity was restored to near initial rates after sonication. The nonchlorinated fraction of degradation products increased after sonication, suggesting more complete, as well as more rapid, degradation. The application of ultrasound to restore an iron barrier holds great promise. Sonication removes obstructive material from an iron surface, improves its activity for the degradation of chlorinated solvents, and is effective even in water environments with a great tendency to form precipitates.

  14. Collision cross-sections of [C,H,O] cations and radical cations from aliphatic [C,H,O] compounds

    NASA Astrophysics Data System (ADS)

    van Houte, J. J.; van Thuijl, J.

    1994-05-01

    Over 260 collision cross-section [sigma]ot, expressed in »ngströms squared, have been determined for the studied ions at 20 and 70 eV by extrapolation of [sigma]t to zero target gas pressure, and these yield two types of structural information. The first type concerns occurrence and detection of cyclic ions, the second isomerization of parent molecular ions and different product ion distributions at 20 and 70 eV. In addition, examples of two distinct fragmentation mechanisms operative in the formation of identical daughter ions from a given precursor could be traced. Formation of cyclic daughter ions is, for instance, observed for C2H3O+ from oxirane, C3H5O+ from oxetane, C4H7O+2 from 4-methyl-1,3-dioxolane. Cyclic molecular ions are formed in varying proportions from oxirane, tetrahydrofuran, 2- and 4-methyl-1,3-dioxolane but not from porpylene oxide, oxetane and 1,3-dioxolane. Isomerization of the parent molecular ion is proposed for the following fragmentations: CH2 from allyl alcohol, CHO2+ from formic acid, C2H2O·+ from oxirane, and C3H6O·+ from 3-methyl butanal and 2-methyl pentanal. Different product ion distributions at 20 and 70 eV were found for C3H5O+ from ethyl propionate and 2-pentanone, C2H4O·+ and C4H8O·+ from butane-1,3-diol, and C3H6O·+ from 2- and 4-methyl-1,3-dioxolane. Two distinct fragmentation mechanisms were traced for the following processes: CH2OH, C2H2O·+ and C2H3O+ from methyl vinyl ether, CH2 and C2H5O+ from butane-1,3-diol and C2H2O·+ from butanone. Self protonation of acetaldehyde also appears to take place by two mechanisms. Energy partitioning is evident in the formation of formyl cations HCO+ but wears off for processes in which larger daughter ions are formed. For formyl cations from straight chain aldehydes, the 70 eV collision cross-section is linearly related to the logarithm of the reciprocal of the number of degrees of freedom in the parent molcule, log (1/DFp). One example of a proton-bound dimer is given, that of acetaldehyde. Its cross-section value is exceptionally high, more than three times than that of its monomer. Such behaviour is probably typical of this type of cation.

  15. Novel one-step headspace dynamic in-syringe liquid phase derivatization-extraction technique for the determination of aqueous aliphatic amines by liquid chromatography with fluorescence detection.

    PubMed

    Muniraj, Sarangapani; Shih, Hou-Kung; Chen, Ying-Fang; Hsiech, Chunming; Ponnusamy, Vinoth Kumar; Jen, Jen-Fon

    2013-06-28

    A novel one-step headspace (HS) dynamic in-syringe (DIS) based liquid-phase derivatization-extraction (LPDE) technique has been developed for the selective determination of two short-chain aliphatic amines (SCAAs) in aqueous samples using high performance liquid chromatography (HPLC) with fluorescence detection (FLD). Methylamine (MA) and dimethylamine (DMA) were selected as model compounds of SCAAs. In this method, a micro-syringe pre-filled with derivatizing reagent solution (9-fluorenylmethyl chloroformate) in the barrel was applied to achieve the simultaneous derivatization and extraction of two methylamines evolved from alkalized aqueous samples through the automated reciprocated movements of syringe plunger. After the derivatization-extraction process, the derivatized phase was directly injected into HPLC-FLD for analysis. Parameters influencing the evolution of methylamines and the HS-DIS-LPDE efficiency, including sample pH and temperature, sampling time, as well as the composition of derivatization reagent, reaction temperature, and frequency of reciprocated plunger movements, were thoroughly examined and optimized. Under optimal conditions, detections were linear in the range of 25-500μgL(-1) for MA and DMA with correlation coefficients all above 0.995. The limits of detection (based on S/N=3) were 5 and 19ngmL(-1) for MA and DMA, respectively. The applicability of the developed method was demonstrated for the determination of MA and DMA in real water samples without any prior cleanup of the sample. The present method provides a simple, selective, automated, low cost and eco-friendly procedure to determine aliphatic amines in aqueous samples.

  16. Methyl oleate deoxygenation for production of diesel fuel aliphatic hydrocarbons over Pd/SBA-15 catalysts

    PubMed Central

    2013-01-01

    Background Catalytic deoxygenation is a prominent process for production of renewable fuels from vegetable oil. In this work, deoxygenation of technical grade methyl oleate to diesel fuel aliphatic hydrocarbons (C15 – C18) is evaluated with several parameters including temperature, hydrogen pressure and reaction time in a stirred batch reactor over Pd/SBA-15 catalysts. Results Two different SBA-15 morphologies i.e. spherelike and necklacelike structures have been synthesize as supports for Pd active metal. It is found that Pd dispersion on necklacelike SBA-15 is higher than that of spherelike SBA-15. Notably, higher Pd dispersion on necklacelike SBA-15 provides significant deoxygenation efficiency as compared to Pd/SBA-15-spherelike. Results show that H2 pressures greatly determine the total ester conversion and selectivity to C15 – C18 aliphatic hydrocarbons. Total ester conversions with 55< selectivity to n-heptadecane are achieved using Pd/SBA-15-necklacelike at 270°C and 60 bar H2 pressure within 6 h reaction time. Gas phase study reveals that formation of C17 is generated via indirect decarbonylation when the reaction time is prolonged. Conclusions Pd/SBA-15-necklacelike catalyst exhibits good catalytic performance with high selectivity to diesellike aliphatic hydrocarbons (C15 – C18). The physicochemical properties of the Pd supported on different SBA-15 morphologies influence the deoxygenation activity of the catalysts. Furthermore, the reaction pathways are governed by the H2 pressure as well as reaction duration. PMID:24011181

  17. Potential Alternatives Report for Validation of Alternatives to Aliphatic Isocyanate Polyurethanes

    NASA Technical Reports Server (NTRS)

    Lewis, pattie

    2011-01-01

    Identifying and selecting alternative materials and technologies that have the potential to reduce the identified HazMats and hazardous air pollutants (HAPs), while incorporating sound corrosion prevention and control technologies, is a complicated task due to the fast pace at which new technologies emerge and rules change. The alternatives are identified through literature searches, electronic database and Internet searches, surveys, and/or personal and professional contacts. Available test data was then compiled on the proposed alternatives to determine if the materials meet the test objectives or if further)laboratory or field-testing will be required. After reviewing technical information documented in the PAR, government representatives, technical representatives from the affected facilities, and other stakeholders involved in the process will select the list of viable alternative coatings for consideration and testing under the project's Joint Test Protocol entitled Joint Test Protocol for Validation of Alternatives to Aliphatic Isocyanate Polyurethanes and Field Test Plan entitled Field Evaluations Test Plan for Validation of Alternatives to Aliphatic Isocyanate Polyurethanes, both prepared by ITB. Test results will be reported in a Joint Test Report upon completion oftesting. The selection rationale and conclusions are documented in this PAR. A cost benefit analysis will be prepared to quantify the estimated capital and process costs of coating alternatives and cost savings relative to the current coating processes, however, some initial cost data has been included in this PAR. For this coatings project, isocyanates, as found in aliphatic isocyanate polyurethanes, were identified as the target HazMat to be eliminated. Table 1-1 lists the target HazMats, the related process and application, current specifications, and affected programs.

  18. Increased mean aliphatic lipid chain length in left ventricular hypertrophy secondary to arterial hypertension

    PubMed Central

    Evaristi, Maria Francesca; Caubère, Céline; Harmancey, Romain; Desmoulin, Franck; Peacock, William Frank; Berry, Matthieu; Turkieh, Annie; Barutaut, Manon; Galinier, Michel; Dambrin, Camille; Polidori, Carlo; Miceli, Cristina; Chamontin, Bernard; Koukoui, François; Roncalli, Jerôme; Massabuau, Pierre; Smih, Fatima; Rouet, Philippe

    2016-01-01

    Abstract About 77.9 million (1 in 4) American adults have high blood pressure. High blood pressure is the primary cause of left ventricular hypertrophy (LVH), which represents a strong predictor of future heart failure and cardiovascular mortality. Previous studies have shown an altered metabolic profile in hypertensive patients with LVH. The goal of this study was to identify blood metabolomic LVH biomarkers by 1H NMR to provide novel diagnostic tools for rapid LVH detection in populations of hypertensive individuals. This cross-sectional study included 48 hypertensive patients with LVH matched with 48 hypertensive patients with normal LV size, and 24 healthy controls. Two-dimensional targeted M-mode echocardiography was performed to measure left ventricular mass index. Partial least squares discriminant analysis was used for the multivariate analysis of the 1H NMR spectral data. From the 1H NMR-based metabolomic profiling, signals coming from methylene (–CH2–) and methyl (–CH3) moieties of aliphatic chains from plasma lipids were identified as discriminant variables. The –CH2–/–CH3 ratio, an indicator of the mean length of the aliphatic lipid chains, was significantly higher (P < 0.001) in the LVH group than in the hypertensive group without LVH and controls. Receiver operating characteristic curve showed that a cutoff of 2.34 provided a 52.08% sensitivity and 85.42% specificity for discriminating LVH (AUC = 0.703, P-value < 0.001). We propose the –CH2–/–CH3 ratio from plasma aliphatic lipid chains as a biomarker for the diagnosis of left ventricular remodeling in hypertension. PMID:27861330

  19. Aliphatic and polycyclic aromatic hydrocarbons in sediments of Kaohsiung Harbour and Adjacent Coast, Taiwan.

    PubMed

    Lee, Chon-Lin; Hsieh, Ming-Tsuen; Fang, Meng-Der

    2005-01-01

    Surficial sediment samples collected from Kaohsiung Harbour and its nearby coast were analyzed for aliphatic hydrocarbons and parent polycyclic aromatic hydrocarbons (PAHs). According to our results, the average total concentrations of n-alkanes (n-C12 to C35) and aromatics (15 PAHs) were 4.33 microg g(-1) dry weight (ranged 0.46-22.60) and 0.59 microg g(-1) dry weight (ranged 0.09-1.75), respectively. The highest concentrations of aliphatic and aromatic hydrocarbons were recorded in stations near the estuaries of Qianzhen River and Love River, respectively. Aliphatic hydrocarbons in the samples indicate that there has been significant non-petrogenic, possibly terrestrial, contribution in the sediment of the open coast of Kaohsiung Harbour and that there has been dominant contribution from petrogenic sources in the sediment of the inner harbour. PAHs, detected in the samples, however, indicated a higher pyrolytic contribution in open-coast samples and a higher petrogenic contribution in the inner harbour. Overall, sediment concentrations of total alkanes in this study were comparable to those found in Victoria Harbour, Hong Kong and are higher than those found in Xiamen Harbour, China. Concentrations of total PAHs in inner Kaohsiung Harbour sediments were relatively lower than those found in Victoria Harbour, Hong Kong and Xiamen Harbour, China, but comparable to those found in Hsin-ta Harbour, Taiwan and Incheon Harbour, Korea. In comparison with several effect-based sediment quality guidelines, most PAH concentrations found in samples taken from inner harbour stations exceeded the Threshold Effect Level of Florida indicating a slight possibility of adverse effects.

  20. The galactic distribution of aliphatic hydrocarbons in the diffuse interstellar medium

    NASA Technical Reports Server (NTRS)

    Sandford, Scott A.; Pendleton, Yvonne J.; Allamandola, Louis J.

    1995-01-01

    The infrared absorption feature near 2950(exp -1) (3.4 micron), characteristic of dust in the diffuse interstellar medium (ISM), is attributed to C-H stretching vibrations of aliphatic hydrocarbons. We show here that the strength of the band does not scale linearly with visual extinction everywhere, but instead increases more rapidly for objects near the center of the Galaxy, a behavior that parallels that of the Si-O stretching band due to silicate materials in the diffuse ISM. This implies that the grains responsible for the diffuse medium aliphatic C-H and silicate Si-O stretching bands are different from those responsible for much of the observed visual extinction. It also suggests that the distribution of the carbonaceous component of the diffuse ISM is not uniform throughout the Galaxy, but instead may increase in density toward the center of the Galaxy. The similar behavior of the C-H and Si-O stretching bands suggests that these two components may be coupled, perhaps in the form of silicate-core, organic-mantle grains. Several possible models of the distribution of this material are presented and it is demonstrated that the inner parts of the Galaxy has a carrier density that is 5 to 35 times higher than in the local ISM. Depending on the model used, the density of aliphatic material in the local ISM is found to be about 1 to 2 -CH3 groups m(exp -3) and about 2 to 5 -CH2- groups m(exp -3). These densities are consistent with the strengths of the 2955 and 2925 cm(exp -1) (3.4 micron) band being described by the relations A(sub nu)/tau(sub 2955 cm(exp -1)) = 270 +/- 40 and A(sub nu)/tau(sub 2925 cm(exp -1)) = 250 +/- 40 in the local diffuse ISM.

  1. Palladium-catalysed C-H activation of aliphatic amines to give strained nitrogen heterocycles

    NASA Astrophysics Data System (ADS)

    McNally, Andrew; Haffemayer, Benjamin; Collins, Beatrice S. L.; Gaunt, Matthew J.

    2014-06-01

    The development of new chemical transformations based on catalytic functionalization of unactivated C-H bonds has the potential to simplify the synthesis of complex molecules dramatically. Transition metal catalysis has emerged as a powerful tool with which to convert these unreactive bonds into carbon-carbon and carbon-heteroatom bonds, but the selective transformation of aliphatic C-H bonds is still a challenge. The most successful approaches involve a `directing group', which positions the metal catalyst near a particular C-H bond, so that the C-H functionalization step occurs via cyclometallation. Most directed aliphatic C-H activation processes proceed through a five-membered-ring cyclometallated intermediate. Considering the number of new reactions that have arisen from such intermediates, it seems likely that identification of distinct cyclometallation pathways would lead to the development of other useful chemical transformations. Here we report a palladium-catalysed C-H bond activation mode that proceeds through a four-membered-ring cyclopalladation pathway. The chemistry described here leads to the selective transformation of a methyl group that is adjacent to an unprotected secondary amine into a synthetically versatile nitrogen heterocycle. The scope of this previously unknown bond disconnection is highlighted through the development of C-H amination and carbonylation processes, leading to the synthesis of aziridines and β-lactams (respectively), and is suggestive of a generic C-H functionalization platform that could simplify the synthesis of aliphatic secondary amines, a class of small molecules that are particularly important features of many pharmaceutical agents.

  2. Molecular Characterization of MYB28 Involved in Aliphatic Glucosinolate Biosynthesis in Chinese Kale (Brassica oleracea var. alboglabra Bailey)

    PubMed Central

    Yin, Ling; Chen, Hancai; Cao, Bihao; Lei, Jianjun; Chen, Guoju

    2017-01-01

    Glucosinolates are Brassicaceae-specific secondary metabolites that act as crop protectants, flavor precursors, and cancer-prevention agents, which shows strong evidences of anticarcinogentic, antioxidant, and antimicrobial activities. MYB28, the R2R3-MYB28 transcription factor, directly activates genes involved in aliphatic glucosinolate biosynthesis. In this study, the MYB28 homology (BoaMYB28) was identified in Chinese kale (Brassica oleracea var. alboglabra Bailey). Analysis of the nucleotide sequence indicated that the cDNA of BoaMYB28 was 1257 bp with an ORF of 1020 bp. The deduced BoaMYB28 protein was a polypeptide of 339 amino acid with a putative molecular mass of 38 kDa and a pI of 6.87. Sequence homology and phylogenetic analysis showed that BoaMYB28 was most closely related to MYB28 homologs from the Brassicaceae family. The expression levels of BoaMYB28 varies across the tissues and developmental stages. BoaMYB28 transcript levels were higher in leaves and stems compared with those in cotyledons, flowers, and siliques. BoaMYB28 was expressed across all developmental leaf stages, with higher transcript accumulation in mature and inflorescence leaves. Over-expression and RNAi studies showed that BoaMYB28 retains the basic MYB28 gene function as a major transcriptional regulator of aliphatic glucosinolate pathway. The results indicated that over-expression and RNAi lines showed no visible difference on plant morphology. The contents of aliphatic glucosinolates and transcript levels of aliphatic glucosinolate biosynthesis genes increased in over-expression lines and decreased in RNAi lines. In over-expression lines, aliphatic glucosinolate contents were 1.5- to 3-fold higher than those in the wild-type, while expression levels of aliphatic glucosinolate biosynthesis genes were 1.5- to 4-fold higher than those in the wild-type. In contrast, the contents of aliphatic glucosinolates and transcript levels of aliphatic glucosinolate biosynthesis genes in RNAi

  3. Molecular Characterization of MYB28 Involved in Aliphatic Glucosinolate Biosynthesis in Chinese Kale (Brassica oleracea var. alboglabra Bailey).

    PubMed

    Yin, Ling; Chen, Hancai; Cao, Bihao; Lei, Jianjun; Chen, Guoju

    2017-01-01

    Glucosinolates are Brassicaceae-specific secondary metabolites that act as crop protectants, flavor precursors, and cancer-prevention agents, which shows strong evidences of anticarcinogentic, antioxidant, and antimicrobial activities. MYB28, the R2R3-MYB28 transcription factor, directly activates genes involved in aliphatic glucosinolate biosynthesis. In this study, the MYB28 homology (BoaMYB28) was identified in Chinese kale (Brassica oleracea var. alboglabra Bailey). Analysis of the nucleotide sequence indicated that the cDNA of BoaMYB28 was 1257 bp with an ORF of 1020 bp. The deduced BoaMYB28 protein was a polypeptide of 339 amino acid with a putative molecular mass of 38 kDa and a pI of 6.87. Sequence homology and phylogenetic analysis showed that BoaMYB28 was most closely related to MYB28 homologs from the Brassicaceae family. The expression levels of BoaMYB28 varies across the tissues and developmental stages. BoaMYB28 transcript levels were higher in leaves and stems compared with those in cotyledons, flowers, and siliques. BoaMYB28 was expressed across all developmental leaf stages, with higher transcript accumulation in mature and inflorescence leaves. Over-expression and RNAi studies showed that BoaMYB28 retains the basic MYB28 gene function as a major transcriptional regulator of aliphatic glucosinolate pathway. The results indicated that over-expression and RNAi lines showed no visible difference on plant morphology. The contents of aliphatic glucosinolates and transcript levels of aliphatic glucosinolate biosynthesis genes increased in over-expression lines and decreased in RNAi lines. In over-expression lines, aliphatic glucosinolate contents were 1.5- to 3-fold higher than those in the wild-type, while expression levels of aliphatic glucosinolate biosynthesis genes were 1.5- to 4-fold higher than those in the wild-type. In contrast, the contents of aliphatic glucosinolates and transcript levels of aliphatic glucosinolate biosynthesis genes in RNAi

  4. Iron-Catalyzed Oxyfunctionalization of Aliphatic Amines at Remote Benzylic C-H Sites.

    PubMed

    Mbofana, Curren T; Chong, Eugene; Lawniczak, James; Sanford, Melanie S

    2016-09-02

    We report the development of an iron-catalyzed method for the selective oxyfunctionalization of benzylic C(sp(3))-H bonds in aliphatic amine substrates. This transformation is selective for benzylic C-H bonds that are remote (i.e., at least three carbons) from the amine functional group. High site selectivity is achieved by in situ protonation of the amine with trifluoroacetic acid, which deactivates more traditionally reactive C-H sites that are α to nitrogen. The scope and synthetic utility of this method are demonstrated via the synthesis and derivatization of a variety of amine-containing, biologically active molecules.

  5. Electrooxidation of aliphatic alcohols on electrodes consisting of hydrophobicized supports coated with nickel oxides

    SciTech Connect

    Chaenko, N.V.; Kornienko, V.L.; Avrutskaya, I.A.; Fioshin, M.Ya.

    1987-12-01

    Two methods are presented to intensify the electrooxidation of aliphatic alcohols with low water solubility and to simplify end-product separation. One method comprised direct addition of higher nickel oxides to the active material of the electrode to be fabricated; the other involved depositing a layer of higher nickel oxides on a hydrophobicized support consisting of a mixture of a conducting material and the FP-4D hydrophobicizer. Electrolysis was carried out in a diaphragm-free two-compartment cell, one reagent and the other the electrolyte. Results are shown of hexyl alcohol oxidation on various composition supports coated with higher nickel oxides.

  6. The fumigant and repellent activity of aliphatic lactones against Pediculus humanus capitis (Anoplura: Pediculidae).

    PubMed

    Toloza, Ariel Ceferino; Zygadlo, Julio; Mougabure-Cueto, Gastón; Zerba, Eduardo; Faillaci, Silvina; Picollo, María Inés

    2006-02-01

    New alternative insecticides are necessary for the chemical control of head lice. In this study the fumigant knockdown time 50% (KT50) and repellency index (RI) of three aliphatic lactones was compared with two essential oils and DDVP, against permethrin-resistance Pediculus humanus capitis from Argentina. In the fumigant assay, none of the lactones were effective compared to the highest activity of eucalyptus (KT50 15.53 m). In the repellency test, the three lactones were equally or more effective (RI ranging from 60.50 to 76.68) than the positive control (piperonal). These lactones are promising as head lice repellents.

  7. Identification and Synthesis of (Z,Z)-8,11-Heptadecadienyl Formate and (Z)-8-Heptadecenyl Formate: Unsaturated Aliphatic Formates Found in the Unidentified Astigmatid Mite, Sancassania sp. Sasagawa (Acari: Acaridae).

    PubMed

    Shimizu, Nobuhiro; Sakata, Daisuke; Miyazaki, Honami; Shimura, Yasuhiro; Kuwahara, Yasumasa

    2016-05-11

    We identified two aliphatic formates, (Z,Z)-8,11-heptadecadienyl formate and (Z)-8-heptadecenyl formate in the opisthonotal gland secretions of an unidentified acarid species, namely Sancassania sp. Sasagawa. Both compounds were isolated using silica gel column chromatography and the structures were elucidated by ¹H-NMR and GC/FT-IR. Further information on the double bond positions was obtained by GC-MS analysis of the corresponding dimethyl disulfide derivatives. Based on the estimated structures of the two formates and using linoleic and oleic acids as the respective starting materials, a simple four-step synthesis was achieved via Barton decarboxylation as the key step. The aliphatic formates identified in acarids thus far are neryl formate ((Z)-3,7-dimethylocta-2,6-dienyl formate) and lardolure (1,3,5,7-tetramethyldecyl formate), and both have been reported to have pheromone functions. The biological function of the two formates isolated in this study is currently being investigated. Although we can speculate that the two compounds were biosynthesized from linoleic and oleic acid, there is a possibility that the synthetic processes featured a novel chain shortening and formic acid esterification mechanism.

  8. Quantum chemical analysis of thermodynamics of 2D cluster formation of alkanes at the water/vapor interface in the presence of aliphatic alcohols.

    PubMed

    Vysotsky, Yu B; Kartashynska, E S; Belyaeva, E A; Fainerman, V B; Vollhardt, D; Miller, R

    2015-11-21

    Using the quantum chemical semi-empirical PM3 method it is shown that aliphatic alcohols favor the spontaneous clusterization of vaporous alkanes at the water surface due to the change of adsorption from the barrier to non-barrier mechanism. A theoretical model of the non-barrier mechanism for monolayer formation is developed. In the framework of this model alcohols (or any other surfactants) act as 'floats', which interact with alkane molecules of the vapor phase using their hydrophobic part, whereas the hydrophilic part is immersed into the water phase. This results in a significant increase of contact effectiveness of alkanes with the interface during the adsorption and film formation. The obtained results are in good agreement with the existing experimental data. To test the model the thermodynamic and structural parameters of formation and clusterization are calculated for vaporous alkanes C(n)H(2n+2) (n(CH3) = 6-16) at the water surface in the presence of aliphatic alcohols C(n)H(2n+1)OH (n(OH) = 8-16) at 298 K. It is shown that the values of clusterization enthalpy, entropy and Gibbs' energy per one monomer of the cluster depend on the chain lengths of corresponding alcohols and alkanes, the alcohol molar fraction in the monolayers formed, and the shift of the alkane molecules with respect to the alcohol molecules Δn. Two possible competitive structures of mixed 2D film alkane-alcohol are considered: 2D films 1 with single alcohol molecules enclosed by alkane molecules (the alcohols do not form domains) and 2D films 2 that contain alcohol domains enclosed by alkane molecules. The formation of the alkane films of the first type is nearly independent of the surfactant type present at the interface, but depends on their molar fraction in the monolayer formed and the chain length of the compounds participating in the clusterization, whereas for the formation of the films of the second type the interaction between the hydrophilic parts of the surfactant is

  9. Determination of low-molecular-mass aliphatic carboxylic acids and inorganic anions from kraft black liquors by ion chromatography.

    PubMed

    Käkölä, Jaana M; Alén, Raimo J; Isoaho, Jukka Pekka; Matilainen, Rose B

    2008-05-09

    An ion chromatographic (IC) method with suppressed conductivity detection (CD) was developed and validated for the quantitative determination of several low-molecular-mass aliphatic mono- and dicarboxylic acids as their carboxylate anions together with some inorganic anions (chloride, sulfate, and thiosulfate) from kraft black liquors. To confirm the identification of some carboxylate anions which lack commercial model substances, a qualitative IC method with suppressed electrospray ionization mass spectrometry (ESI-MS) was also developed. The separations were performed on an IonPac AS 11-HC anion-exchange column operated at 25 degrees C within 25 min by a gradient elution with aqueous potassium hydroxide (suppressed CD in the AutoRegen mode) or sodium hydroxide (suppressed ESI-MS in the pressurized bottle mode). In the validation process a mixture of carboxylic acids and inorganic anions in aqueous media and in seven different types of wood and non-wood black liquor samples were quantitatively analyzed by IC-CD. As a result, calibration lines with correlation coefficients of 1.00 for all analytes were achieved at a concentration range from 0.05 to 105 mg L(-1). In black liquor samples intra-day (n=6) precision values ranged from 0.9 to 5%. Day-to-day (n1=3) and intermediate precision values were less than 5% for all other compounds except sulfate and thiosulfate. The variability in the thiosulfate and sulfate results is due in large part to the oxidation of sulfide and thiosulfate, respectively. Recoveries were close to 100% with standard deviations less than 8%. Depending of the analyte, the limits of detection and quantification were, respectively, between 1 and 8 microg L(-1) and between 3 and 27 microg L(-1) for standard compounds in aqueous media and between 6 and 106 microg L(-1) and between 14 and 148 microg L(-1) for black liquor samples. These validation results clearly indicated that with respect to selectivity, linearity, limits of detection and

  10. Woody Plant Invasion of Grassland: Lignin and Aliphatic Biopolymer Chemistry and Carbon Isotope Composition in Physical Fractions

    NASA Astrophysics Data System (ADS)

    Gamblin, D.; Boutton, T.; Liao, J.; Jastrow, J.; Filley, T.

    2003-12-01

    Significant changes in the apportionment of organic carbon in grassland and savanna soils have been document as a result of woody plant encroachment. In the Rio Grande Plains of Texas, C4 grasslands (d13C = -14 0/00) have undergone succession to trees and shrubs of a subtropical thorn woodland (d13C = -27 0/00) over the past 150 y which has resulted in increased soil organic carbon storage. Large differences in the turnover times of physical fractions in this system indicate selective preservation mechanisms which may include physical protection or inherent biochemical recalcitrance. To elucidate mechanisms of SOC sequestration during woody plant succession in this system, we are investigating the chemistry and compound-specific stable carbon isotope composition of lignin and aliphatic biopolymers in specific physical (size, density) soil fractions within a chronosequence that includes remnant grasslands (Time 0) and woody plant stands ranging in age from 10-130 y. The soil fraction data is being compared to biopolymer and isotope chemistry of the root, stem and/or leaf tissue of 20 of the dominant genus of plants in the system. Lignin phenols and suberin and cutin-derived hydroxyfatty acids are being isolated using alkaline CuO oxidation and tetramethylammonium hydroxide thermochemolysis. A comparison of the macroaggregate (greater than 250 um), microaggregate (53-250 um), and free silt and clay fractions in the oldest stand indicates that lignin is the most concentrated (organic carbon normalized values) in macroaggregates and is significantly less degraded, as determined by relative yields of oxidized and reduced lignin phenols. Additionally, the intra-aggregate silt and clay fraction from the macroaggregates contains less than half of the organic carbon normalized lignin phenols and is relatively more oxidized than what is found in the total macroaggregate pool. From these preliminary results it appears that the bulk macroaggregate pool contains the least

  11. [Cloning and analysis of a new aliphatic amidase gene from Rhodococcus erythropolis TA37].

    PubMed

    Lavrov, K V; Karpova, I Yu; Epremyan, A S; Yanenko, A S

    2014-10-01

    A new aliphatic amidase gene (ami), having a level of similarity with the nearest homologs of no more than 77%, was identified in the Rhodococcus erythropolis TA37 strain, which is able to hydrolyze a wide range of amides. The amidase gene was cloned within a 3.7 kb chromosomal locus, which also contains putative acetyl-CoA ligase and ABC-type transportergenes. The structure of this locus in the R. erythropolis TA37 strain differs from the structure of loci in other Rhodococcus strains. The amidase gene is expressed in Escherichia coli cells. It was demonstrated that amidase (generated in the recombinant strain) efficiently hydrolyzes acetamide (aliphatic anmide) and does not use 4'-nitroacetanilide (N-substituted amide) as a substrate. Insertional inactivation of the amidase gene in the R. erythropolis TA37 strain results in a considerable decrease (by at least 6-7 times) in basal amidase activity, indicating functional amidase activity in the R. erythropolis TA37 strain.

  12. New aliphatic glycerophosphoryl-containing polyurethanes: synthesis, platelet adhesion and elution cytotoxicity studies.

    PubMed

    Acetti, Daniela; D'Arrigo, Paola; Giordano, Carmen; Macchi, Piero; Servi, Stefano; Tessaro, Davide

    2009-04-01

    in this study new poly(ether)urethanes (PeUs) based on aliphatic diisocyanates were synthesized with phospholipid-like residues as chain extenders. The primary objective was to prepare new polyurethanes from diisocyanates that are less toxic than the aromatic ones widely used in medical-grade polyurethanes, in order to investigate the effect of the different aromatic or aliphatic hard segment content on the final properties of the materials. Some glycerophospho residues were simultaneously introduced to enhance the hemocompatibility of these materials. Polymers were prepared by a conventional two-step solution polymerization procedure using hexamethylene diisocyanate (HDi) and dodecametilendiisocyanate (DDi) and poly(1,4-butanediol) with molecular weight 1000 to form prepolymers, which were subsequently polymerized with 1-glycerophosphorylcholine (1-GPC) or glycerophosphorylserine (GPS) to act as chain extenders. The reference polymers bearing 1,4-butandiol (BD) were also synthesized. The polymers obtained were characterized by fourier transform infrared spectroscopy (fT-iR), nuclear magnetic resonance (1H nmR), and differential scanning calorimetry (DSC). The hemocompatibility of synthesized segmented polyurethanes was preliminarily investigated by platelet-rich plasma contact studies and related scanning electron microscopy (Sem) photographs as well as by cell viability assay after cell exposure to material elutions to assess the effect of any toxic leachables coming out from the samples. Two of the polymers gave interesting results, suggesting the desirability of further investigation into their possible use in biomedical devices.

  13. Aliphatic and aromatic hydrocarbons in different sized aerosols over the Mediterranean Sea: Occurrence and origin

    NASA Astrophysics Data System (ADS)

    Sicre, M. A.; Marty, J. C.; Saliot, A.; Aparicio, X.; Grimalt, J.; Albaiges, J.

    Marine aerosols were collected using a five-stage cascade impactor during the PHYCEMED II cruise in the Western Mediterranean Sea (October 1983). Their composition in aliphatic and aromatic hydrocarbons (HCs) was analyzed, representing the first time that concentrations of polynuclear aromatic HCs (PAH) are reported in relation to particle size for aerosols of remote marine areas. The HC concentrations were found to be dependent on the origin of the air masses. They were higher for air coming from North European countries than for air originating in the Atlantic and the South of Spain. The concentrations range between 7 and 14 ng m -3for n-alkanes and between 0.2 and 0.4 ng m -3for total PAH. Based on molecular criteria, several sources for these HCs have been identified: continental higher plant waxes, petroleum and pyrolysis (namely coal combustion and vehicular exhausts). Mass medium equivalent diameters (MMED) for the naturally derived n-alkanes are in the 1.79-2.53 μm range, indicating an origin related with the emission of large particles from higher plant waxes or from soil dusts. In contrast, MMED for the anthropogenic HCs, both aliphatic and aromatic, are smaller than the micron, suggesting initial emission of PAH through pyrolytic processes in the vapor phase followed by condensation onto larger sub-μm particles.

  14. Encapsulation of testosterone and its aliphatic and aromatic dimers by milk beta-lactoglobulin.

    PubMed

    Chanphai, P; Vesper, A R; Bekale, L; Bérubé, G; Tajmir-Riahi, H A

    2015-05-01

    The encapsulation of testosterone and it aliphatic dimer (alip) and aromatic dimer (arom) with milk β-lactoglobulin (β-LG) was studied in aqueous solution at pH 7.4. Multiple spectroscopic methods, transmission electron microscopy (TEM) and molecular modeling were used to characterize testosterone-β-LG binding and protein aggregation process. Spectroscopic analysis showed that steroids bind β-LG via hydrophobic and H-bonding interactions with overall binding constants K test-β-LG = 5.6 (± 0.6) × 10(4)M(-1), K test-dimeralip-β-LG = 4.8 (± 0.5) × 10(3)M(-1) and K test-dimer-arom-β-LG = 2.9 (± 0.4) × 10(4)M(-1). The binding affinity was testosterone > testosterone dimer-aromatic > testosterone dimer-aliphatic. Transmission electron microscopy showed major changes in protein morphology as testosterone-protein complexation occurred with increase in the diameter of the protein aggregate indicating encapsulation of steroids by β-LG. Modeling showed the presence of H-bonding stabilized testosterone-β-LG complexes with the free binding energy of -9.82 Kcal/mol indicating that the interaction process is spontaneous at room temperature.

  15. Far infrared spectra of solid state aliphatic amino acids in different protonation states

    NASA Astrophysics Data System (ADS)

    Trivella, Aurélien; Gaillard, Thomas; Stote, Roland H.; Hellwig, Petra

    2010-03-01

    Far infrared spectra of zwitterionic, cationic, and anionic forms of aliphatic amino acids in solid state have been studied experimentally. Measurements were done on glycine, L-alanine, L-valine, L-leucine, and L-isoleucine powder samples and film samples obtained from dried solutions prepared at pH ranging from 1 to 13. Solid state density functional theory calculations were also performed, and detailed potential energy distributions were obtained from normal mode results. A good correspondence between experimental and simulated spectra was achieved and this allowed us to propose an almost complete band assignment for the far infrared spectra of zwitterionic forms. In the 700-50 cm-1 range, three regions were identified, each corresponding to a characteristic set of normal modes. A first region between 700 and 450 cm-1 mainly contained the carboxylate bending, rocking, and wagging modes as well as the ammonium torsional mode. The 450-250 cm-1 region was representative of backbone and sidechain skeletal bending modes. At last, the low wavenumber zone, below 250 cm-1, was characteristic of carboxylate and skeletal torsional modes and of lattice modes. Assignments are also proposed for glycine cationic and anionic forms, but could not be obtained for all aliphatic amino acids due to the lack of structural data. This work is intended to provide fundamental information for the understanding of peptides vibrational properties.

  16. Application of flow-injection potentiometric system for determination of total concentration of aliphatic carboxylic acids.

    PubMed

    Mroczkiewicz, Monika; Górski, Łukasz; Zamojska-Jaroszewicz, Anna; Szewczyk, Krzysztof W; Malinowska, Elżbieta

    2011-09-30

    In this work, flow-injection system with potentiometric detection was tested for determination of total carboxylic acid concentration. Detection part of the examined system consists of ion-selective electrodes (ISEs) with polymer membranes of different compositions. First electrode is based on Zr(IV)-tetraphenylporphyrin as ionophore selective towards carboxylic acid anions, the membrane of second one contains only liphophilic anion exchanger - tridodecylmethylammonium chloride. Final response of the system is a result of combination of EMF signals from both electrodes. Combination of two detectors enables significant decrease of differences between potentiometric signals induced by mixtures of studied anions of various concentrations as compared to results obtained only with metalloporphyrin-based ISE. The use of anion-exchanger based detector allows for elimination of the influence of aliphatic carboxylic acids lipophilicity. Proposed potentiometric flow-injection system was employed for determination of short-chain aliphatic carboxylic acids (so-called VFA - volatile fatty acids) in samples originating from an anaerobic digester. Results obtained for these relatively complicated samples are in good agreement with results obtained with the use of reference colorimetric method. Linear response towards carboxylic acids was observed in the concentration range of 10(-4) to 10(-2)mold m(-3), with the slopes in the range of -110 to -150 mV dec(-1) (for acetate(-) and butyrate(-), respectively). System enables for determination of about 6 samples per hour. Life time of ISEs average about 2 months. Copyright © 2011 Elsevier B.V. All rights reserved.

  17. Far infrared spectra of solid state aliphatic amino acids in different protonation states.

    PubMed

    Trivella, Aurélien; Gaillard, Thomas; Stote, Roland H; Hellwig, Petra

    2010-03-21

    Far infrared spectra of zwitterionic, cationic, and anionic forms of aliphatic amino acids in solid state have been studied experimentally. Measurements were done on glycine, L-alanine, L-valine, L-leucine, and L-isoleucine powder samples and film samples obtained from dried solutions prepared at pH ranging from 1 to 13. Solid state density functional theory calculations were also performed, and detailed potential energy distributions were obtained from normal mode results. A good correspondence between experimental and simulated spectra was achieved and this allowed us to propose an almost complete band assignment for the far infrared spectra of zwitterionic forms. In the 700-50 cm(-1) range, three regions were identified, each corresponding to a characteristic set of normal modes. A first region between 700 and 450 cm(-1) mainly contained the carboxylate bending, rocking, and wagging modes as well as the ammonium torsional mode. The 450-250 cm(-1) region was representative of backbone and sidechain skeletal bending modes. At last, the low wavenumber zone, below 250 cm(-1), was characteristic of carboxylate and skeletal torsional modes and of lattice modes. Assignments are also proposed for glycine cationic and anionic forms, but could not be obtained for all aliphatic amino acids due to the lack of structural data. This work is intended to provide fundamental information for the understanding of peptides vibrational properties.

  18. Exploring 3D structural influences of aliphatic and aromatic chemicals on α-cyclodextrin binding.

    PubMed

    Linden, Lukas; Goss, Kai-Uwe; Endo, Satoshi

    2016-04-15

    Binding of solutes to macromolecules is often influenced by steric effects caused by the 3D structures of both binding partners. In this study, the 1:1 α-cyclodextrin (αCD) binding constants (Ka1) for 70 organic chemicals were determined to explore the solute-structural effects on the αCD binding. Ka1 was measured using a three-part partitioning system with either a headspace or a passive sampler serving as the reference phase. The Ka1 values ranged from 1.08 to 4.97 log units. The results show that longer linear aliphatic chemicals form more stable complexes than shorter ones, and that the position of the functional group has a strong influence on Ka1, even stronger than the type of the functional group. Comparison of linear and variously branched aliphatic chemicals indicates that having a sterically unhindered alkyl chain is favorable for binding. These results suggest that only one alkyl chain can enter the binding cavity. Relatively small aromatic chemicals such as 1,3-dichlorobenzene bind to αCD well, while larger ones like tetrachlorobenzene and 3-ring aromatic chemicals show only a weak interaction with αCD, which can be explained by cavity exclusion. The findings of this study help interpret cyclodextrin binding data and facilitate the understanding of binding processes to macromolecules.

  19. The FEMA GRAS assessment of aliphatic and aromatic terpene hydrocarbons used as flavor ingredients.

    PubMed

    Adams, T B; Gavin, C Lucas; McGowen, M M; Waddell, W J; Cohen, S M; Feron, V J; Marnett, L J; Munro, I C; Portoghese, P S; Rietjens, I M C M; Smith, R L

    2011-10-01

    This publication is the thirteenth in a series of safety evaluations performed by the Expert Panel of the Flavor and Extract Manufacturers Association (FEMA). In 1993, the Panel initiated a comprehensive program to re-evaluate the safety of more than 1700 GRAS flavoring substances under conditions of intended use. Since then, the number of flavoring substances has grown to more than 2600 substances. Elements that are fundamental to the safety evaluation of flavor ingredients include exposure, structural analogy, metabolism, pharmacokinetics and toxicology. Flavor ingredients are evaluated individually and in the context of the available scientific information on the group of structurally related substances. Scientific data relevant to the safety evaluation of the use of aliphatic and aromatic terpene hydrocarbons as flavoring ingredients are evaluated. The group of aliphatic and aromatic terpene hydrocarbons was reaffirmed as GRAS (GRASr) based, in part, on their self-limiting properties as flavoring substances in food; their rapid absorption, metabolic detoxication, and excretion in humans and other animals; their low level of flavor use; the wide margins of safety between the conservative estimates of intake and the no-observed-adverse effect levels determined from subchronic and chronic studies and the lack of significant genotoxic potential.

  20. Competitive Oxidation and Reduction of Aliphatic Alcohols over (WO3)3 Clusters

    SciTech Connect

    Kim, Yu K.; Dohnalek, Zdenek; Kay, Bruce D.; Rousseau, Roger J.

    2009-06-04

    The reactions of C1 to C4 aliphatic alcohols over (WO3)3 clusters were studied experimentally and theoretically using temperature-programmed desorption, infrared reflection-absorption spectroscopy and density functional theory. The results reveal that all C1 to C4 aliphatic alcohols readily react with (WO3)3 clusters by heterolytic cleavage of the RO-H bond to give alkoxy (RO ) bound to W(VI) centers and a proton (H+) attached to the terminal oxygen atom of a tungstyl group (W=O). Two protons adsorbed onto the cluster readily react with the doubly-bonded oxygen to from a water molecule that desorbs at 200-300 K and the alkoxy that undergoes decomposition at higher temperatures into the corresponding alkene, aldehyde, and/or ether. Our theory predicts that all three channels proceed over the W(VI) Lewis acid site with energy barriers of 30-40 kcal/mol, where dehydration is favored over the others. We also present further analysis of the yield and reaction temperature as a function of the alkyl substituents and discuss the origin of the reaction selectivity among the three reaction channels.

  1. Halides with Fifteen Aliphatic C–H···Anion Interaction Sites

    PubMed Central

    Shi, Genggongwo; Aliakbar Tehrani, Zahra; Kim, Dongwook; Cho, Woo Jong; Youn, Il-Seung; Lee, Han Myoung; Yousuf, Muhammad; Ahmed, Nisar; Shirinfar, Bahareh; Teator, Aaron J.; Lastovickova, Dominika N.; Rasheed, Lubna; Lah, Myoung Soo; Bielawski, Christopher W.; Kim, Kwang S.

    2016-01-01

    Since the aliphatic C–H···anion interaction is relatively weak, anion binding using hydrophobic aliphatic C–H (Cali–H) groups has generally been considered not possible without the presence of additional binding sites that contain stronger interactions to the anion. Herein, we report X-ray structures of organic crystals that feature a chloride anion bound exclusively by hydrophobic Cali–H groups. An X-ray structure of imidazolium-based scaffolds using Cali–H···A− interactions (A− = anion) shows that a halide anion is directly interacting with fifteen Cali–H groups (involving eleven hydrogen bonds, two bidentate hydrogen-bond-type binding interactions and two weakly hydrogen-bonding-like binding interactions). Additional supporting interactions and/or other binding sites are not observed. We note that such types of complexes may not be rare since such high numbers of binding sites for an anion are also found in analogous tetraalkylammonium complexes. The Cali–H···A− interactions are driven by the formation of a near-spherical dipole layer shell structure around the anion. The alternating layers of electrostatic charge around the anion arise because the repulsions between weakly positively charged H atoms are reduced by the presence of the weakly negatively charged C atoms connected to H atoms. PMID:27444513

  2. Effect of testosterone and its aliphatic and aromatic dimers on DNA morphology.

    PubMed

    Chanphai, P; Agudelo, D; Vesper, A R; Bérubé, G; Tajmir-Riahi, H A

    2017-02-01

    Conjugation of DNA with testosterone and it aliphatic dimer (alip) and aromatic dimer (arom) was investigated in aqueous solution at pH 7.4. Multiple spectroscopic methods, transmission electron microscopy (TEM) and molecular modeling were used to characterize steroid-DNA binding and DNA morphology. Spectroscopic analysis showed that testosterone binds DNA via A7, A16, A17, T8, T15 and T18 nucleobases with overall binding constants Ktest-DNA=1.8 (±0.4)×10(4)M(-1), Ktest-dimeralip-DNA=5.7 (±0.7)×10(4)M(-1) and Ktest-dimer-arom-DNA=7.3 (±0.9)×10(4)M(-1). The binding affinity increases in this order: testosterone dimer-aromatic>testosterone dimer-aliphatic>testosterone. The steroid loading efficacy was 40-50%. Transmission electron microscopy showed major changes in DNA morphology as testosterone-DNA interaction occurred with increase in the diameter of the DNA aggregate, indicating encapsulation of testosterone by DNA. Modeling showed the presence of several nucleobases attached to testosterone with the free binding energy of -4.93Kcal/mol.

  3. Two new aliphatic lactones from the fruits of Coriandrum sativum L.

    PubMed Central

    2012-01-01

    Background The present paper describes the isolation and characterization of two new aliphatic δ-lactones along with three glycerides and n-nonadecanyl cetoleate from the fruits of Coriandrum sativum L. (Apiaceae). The structures of all the isolated phytoconstituents have been established on the basis of spectral data analysis and chemical reactions. Results Phytochemical investigation of the methanolic extract of C. sativum L. (Apiaceae) fruits resulted in the isolation of two new aliphatic δ-lactones characterized as 2α-n-heptatriacont-(Z)-3-en-1,5-olide (1) (coriander lactone) and 2α-n-tetracont-(Z,Z)-3,26-dien-18α-ol-1,5-olide (2) (hydroxy coriander lactone) together with glyceryl-1,2-dioctadec-9,12-dienoate-3-octadec-9-enoate (3); glyceryl-1,2,3-trioctadecanoate (4); n-nonadecanyl-n-docos-11-enoate (5) and oleiyl glucoside (6). Conclusions Phytochemical investigation of the methanolic extract of C. sativum gave coriander lactone and hydroxy coriander lactone as the new phytoconstituents. PMID:22800677

  4. Halides with Fifteen Aliphatic C–H···Anion Interaction Sites

    NASA Astrophysics Data System (ADS)

    Shi, Genggongwo; Aliakbar Tehrani, Zahra; Kim, Dongwook; Cho, Woo Jong; Youn, Il-Seung; Lee, Han Myoung; Yousuf, Muhammad; Ahmed, Nisar; Shirinfar, Bahareh; Teator, Aaron J.; Lastovickova, Dominika N.; Rasheed, Lubna; Lah, Myoung Soo; Bielawski, Christopher W.; Kim, Kwang S.

    2016-07-01

    Since the aliphatic C–H···anion interaction is relatively weak, anion binding using hydrophobic aliphatic C–H (Cali–H) groups has generally been considered not possible without the presence of additional binding sites that contain stronger interactions to the anion. Herein, we report X-ray structures of organic crystals that feature a chloride anion bound exclusively by hydrophobic Cali–H groups. An X-ray structure of imidazolium-based scaffolds using Cali–H···A‑ interactions (A‑ = anion) shows that a halide anion is directly interacting with fifteen Cali–H groups (involving eleven hydrogen bonds, two bidentate hydrogen-bond-type binding interactions and two weakly hydrogen-bonding-like binding interactions). Additional supporting interactions and/or other binding sites are not observed. We note that such types of complexes may not be rare since such high numbers of binding sites for an anion are also found in analogous tetraalkylammonium complexes. The Cali–H···A‑ interactions are driven by the formation of a near-spherical dipole layer shell structure around the anion. The alternating layers of electrostatic charge around the anion arise because the repulsions between weakly positively charged H atoms are reduced by the presence of the weakly negatively charged C atoms connected to H atoms.

  5. Pd-catalysed ligand-enabled carboxylate-directed highly regioselective arylation of aliphatic acids

    PubMed Central

    Zhu, Yan; Chen, Xiaolan; Yuan, Chunchen; Li, Guobao; Zhang, Jingyu; Zhao, Yingsheng

    2017-01-01

    α-amino acids bearing aromatic side chains are important synthetic units in the synthesis of peptides and natural products. Although various β-C-H arylation methodologies for amino acid derivatives involving the assistance of directing groups have been extensively developed, syntheses that directly employ N-protected amino acids as starting materials remain rare. Herein, we report an N-acetylglycine-enabled Pd-catalysed carboxylate-directed β-C(sp3)-H arylation of aliphatic acids. In this way, various non-natural amino acids can be directly prepared from phthaloylalanine in one step in good to excellent yields. Furthermore, a series of aliphatic acids have been shown to be amenable to this transformation, affording β-arylated propionic acid derivatives in moderate to good yields. More importantly, this ligand-enabled direct β-C(sp3)-H arylation could be easily scaled-up to 10 g under reflux conditions, highlighting the potential utility of this synthetic method. PMID:28383026

  6. [Analysis of aliphatic carboxylic acids in anaerobic digestion process waters by ion-exclusion chromatography].

    PubMed

    Ito, Kazuaki; Sakamoto, Jun; Nagaoka, Kazuya; Takayama, Yohichi; Kanahori, Takashi; Sunahara, Hiroshi; Hayashi, Tsuneo; Sato, Shinji; Hirokawa, Takeshi; Tanaka, Kazuhiko

    2012-04-01

    The analysis of seven aliphatic carboxylic acids (formic, acetic, propionic, iso-butyric, n-butyric, iso-valeric and n-valeric acid) in anaerobic digestion process waters for biogas production was examined by ion-exclusion chromatography with dilute acidic eluents (benzoic acid, perfluorobutyric acid (PFBA) and sulfuric acid) and non-suppressed conductivity/ultraviolet (UV) detection. The columns used were a styrene/divinylbenzene-based strongly acidic cation-exchange resin column (TSKgel SCX) and a polymethacrylate-based weakly acidic cation-exchange resin column (TSKgel Super IC-A/C). Good separation was performed on the TSKgel SCX in shorter retention times. For the TSKgel Super IC-A/C, peak shape of the acids was sharp and symmetrical in spite of longer retention times. In addition, the mutual separation of the acids was good except for iso- and n-butyric acids. The better separation and good detection was achieved by using the two columns (TSKgel SCX and TSKgel Super IC-A/C connected in series), lower concentrations of PFBA and sulfuric acid as eluents, non-suppressed conductivity detection and UV detection at 210 nm. This analysis was applied to anaerobic digestion process waters. The chromatograms with conductivity detection were relatively simpler compared with those of UV detection. The use of two columns with different selectivities for the aliphatic carboxylic acids and the two detection modes was effective for the determination and identification of the analytes in anaerobic digestion process waters containing complex matrices.

  7. Aliphatic and chlorinated alkenes and epoxides as inducers of alkene monooxygenase and epoxidase activities in Xanthobacter strain Py2

    SciTech Connect

    Ensign, S.A.

    1996-01-01

    Xanthobacter strain Py2 is one of a number of bacteria capable of aerobic growth using aliphatic alkenes as the sole carbon and energy source. The oxidation of alkenes in initiated by an alkene monooxygenase which catalyzes the CO{sub 2} and reductant-dependent oxidation of the alkenes to their corresponding epoxides. In this study, the induction of the alkene-oxidizing enzymes of Xantheobacter strain Py2 by the physiological substrates propylene and proplyene oxide is characterized. A variety of aliphatic and chlorinated alkenes and epoxides are shown to serve as effective inducers of the system. 21 refs., 6 figs., 2 tabs.

  8. A Bioinspired Catalytic Aerobic Oxidative C–H Functionalization of Primary Aliphatic Amines: Synthesis of 1,2-Disubstituted Benzimidazoles

    PubMed Central

    Nguyen, Khac Minh Huy; Largeron, Martine

    2015-01-01

    Aerobic oxidative C–H functionalization of primary aliphatic amines has been accomplished with a biomimetic cooperative catalytic system to furnish 1,2-disubstituted benzimidazoles that play an important role as drug discovery targets. This one-pot atom-economical multistep process, which proceeds under mild conditions, with ambient air and equimolar amounts of each coupling partner, constitutes a convenient environmentally friendly strategy to functionalize non-activated aliphatic amines that remain challenging substrates for non-enzymatic catalytic aerobic systems. PMID:26206475

  9. Design and Comparative Evaluation of the Anticonvulsant Profile, Carbonic-Anhydrate Inhibition and Teratogenicity of Novel Carbamate Derivatives of Branched Aliphatic Carboxylic Acids with 4-Aminobenzensulfonamide.

    PubMed

    Bibi, David; Mawasi, Hafiz; Nocentini, Alessio; Supuran, Claudiu T; Wlodarczyk, Bogdan; Finnell, Richard H; Bialer, Meir

    2017-03-09

    Epilepsy is one of the most common neurological diseases, with between 34 and 76 per 100,000 people developing epilepsy annually. Epilepsy therapy for the past 100(+) years is based on the use of antiepileptic drugs (AEDs). Despite the availability of more than twenty old and new AEDs, approximately 30% of patients with epilepsy are not seizure-free with the existing medications. In addition, the clinical use of the existing AEDs is restricted by their side-effects, including the teratogenicity associated with valproic acid that restricts its use in women of child-bearing age. Thus, there is an unmet clinical need to develop new, effective AEDs. In the present study, a novel class of carbamates incorporating phenethyl or branched aliphatic chains with 6-9 carbons in their side-chain, and 4-benzenesulfonamide-carbamate moieties were synthesized and evaluated for their anticonvulsant activity, teratogenicity and carbonic anhydrase (CA) inhibition. Three of the ten newly synthesized carbamates showed anticonvulsant activity in the maximal-electroshock (MES) and 6 Hz tests in rodents. In mice, 3-methyl-2-propylpentyl(4-sulfamoylphenyl)carbamate(1), 3-methyl-pentan-2-yl-(4-sulfamoylphenyl)carbamate (9) and 3-methylpentyl, (4-sulfamoylphenyl)carbamate (10) had ED50 values of 136, 31 and 14 mg/kg (MES) and 74, 53, and 80 mg/kg (6 Hz), respectively. Compound (10) had rat-MES-ED50 = 13 mg/kg and ED50 of 59 mg/kg at the mouse-corneal-kindling test. These potent carbamates (1,9,10) induced neural tube defects only at doses markedly exceeding their anticonvuslnat-ED50 values. None of these compounds were potent inhibitors of CA IV, but inhibited CA isoforms I, II and VII. The anticonvulsant properties of these compounds and particularly compound 10 make them potential candidates for further evaluation and development as new AEDs.

  10. Polybenzimidazole compounds

    DOEpatents

    Klaehn, John R.; Peterson, Eric S.; Wertsching, Alan K.; Orme, Christopher J.; Luther, Thomas A.; Jones, Michael G.

    2010-08-10

    A PBI compound that includes imidazole nitrogens, at least a portion of which are substituted with an organic-inorganic hybrid moiety. At least 85% of the imidazole nitrogens may be substituted. The organic-inorganic hybrid moiety may be an organosilane moiety, for example, (R)Me.sub.2SiCH.sub.2--, where R is selected from among methyl, phenyl, vinyl, and allyl. The PBI compound may exhibit similar thermal properties in comparison to the unsubstituted PBI. The PBI compound may exhibit a solubility in an organic solvent greater than the solubility of the unsubstituted PBI. The PBI compound may be included in separatory media. A substituted PBI synthesis method may include providing a parent PBI in a less than 5 wt % solvent solution. Substituting may occur at about room temperature and/or at about atmospheric pressure. Substituting may use at least five equivalents in relation to the imidazole nitrogens to be substituted or, preferably, about fifteen equivalents.

  11. Polybenzimidazole compounds

    SciTech Connect

    Klaehn, John R; Peterson, Eric S; Orme, Christopher J; Jones, Michael G; Wertsching, Alan K; Luther, Thomas A; Trowbridge, Tammy L

    2011-11-22

    A PBI compound includes imidazole nitrogens at least a portion of which are substituted with a moiety containing a carbonyl group, the substituted imidazole nitrogens being bonded to carbon of the carbonyl group. At least 85% of the nitrogens may be substituted. The carbonyl-containing moiety may include RCO--, where R is alkoxy or haloalkyl. The PBI compound may exhibit a first temperature marking an onset of weight loss corresponding to reversion of the substituted PBI that is less than a second temperature marking an onset of decomposition of an otherwise identical PBI compound without the substituted moiety. The PBI compound may be included in separatory media. A substituted PBI synthesis method may include providing a parent PBI in a less than 5 wt % solvent solution. Substituting may use more than 5 equivalents in relation to the imidazole nitrogens to be substituted.

  12. Aromatic and aliphatic CH hydrogen bonds fight for chloride while competing alongside ion pairing within triazolophanes.

    PubMed

    Hua, Yuran; Ramabhadran, Raghunath O; Uduehi, Esther O; Karty, Jonathan A; Raghavachari, Krishnan; Flood, Amar H

    2011-01-03

    Triazolophanes are used as the venue to compete an aliphatic propylene CH hydrogen-bond donor against an aromatic phenylene one. Longer aliphatic C-H...Cl(-) hydrogen bonds were calculated from the location of the chloride within the propylene-based triazolophane. The gas-phase energetics of chloride binding (ΔG(bind) , ΔH(bind) , ΔS(bind) ) and the configurational entropy (ΔS(config) ) were computed by taking all low-energy conformations into account. Comparison between the phenylene- and propylene-based triazolophanes shows the computed gas-phase free energy of binding decreased from ΔG(bind) =-194 to -182 kJ mol(-1) , respectively, with a modest enthalpy-entropy compensation. These differences were investigated experimentally. An (1) H NMR spectroscopy study on the structure of the propylene triazolophane's 1:1 chloride complex is consistent with a weaker propylene CH hydrogen bond. To quantify the affinity differences between the two triazolophanes in dichloromethane, it was critical to obtain an accurate binding model. Four equilibria were identified. In addition to 1:1 complexation and 2:1 sandwich formation, ion pairing of the tetrabutylammonium chloride salt (TBA(+) ⋅Cl(-) ) and cation pairing of TBA(+) with the 1:1 triazolophane-chloride complex were observed and quantified. Each complex was independently verified by ESI-MS or diffusion NMR spectroscopy. With ion pairing deconvoluted from the chloride-receptor binding, equilibrium constants were determined by using (1) H NMR (500 μM) and UV/Vis (50 μM) spectroscopy titrations. The stabilities of the 1:1 complexes for the phenylene and propylene triazolophanes did not differ within experimental error, ΔG=(-38±2) and (-39±1) kJ mol(-1) , respectively, as verified by an NMR spectroscopy competition experiment. Thus, the aliphatic CH donor only revealed its weaker character when competing with aromatic CH donors within the propylene-based triazolophane.

  13. Re-investigation of the Ponzio reaction for the preparation of gem-dinitro compounds

    SciTech Connect

    Honey, P.J.; Millar, R.W.; Coombes, R.G.

    1995-12-01

    Many aromatic nitro compounds can be prepared using mixtures of nitric and sulphuric acids, but, this medium usually results in the destruction of the substrate for aliphatic compounds. Hence a variety of less aggressive nitrating agents in nonacidic media are employed. This talk presents some recent work to re-investigate the Ponzio reaction for the conversion of oximes to the gem-nitro group. The effect of varying the reaction media, and of changing the nitrating species from N{sub 2}O{sub 4} to N{sub 2}O{sub 5} will also be presented. The reaction mechanism will be discussed with reference to CIDNP nmr studies. Where relevant the results will be compared with other aliphatic nitration methods.

  14. Determination of sulfur compounds in hydrotreated transformer base oil by potentiometric titration.

    PubMed

    Chao, Qiu; Sheng, Han; Cheng, Xingguo; Ren, Tianhui

    2005-06-01

    A method was developed to analyze the distribution of sulfur compounds in model sulfur compounds by potentiometric titration, and applied to analyze hydrotreated transformer base oil. Model thioethers were oxidized to corresponding sulfoxides by tetrabutylammonium periodate and sodium metaperiodate, respectively, and the sulfoxides were titrated by perchloric acid titrant in acetic anhydride. The contents of aliphatic thioethers and total thioethers were then determined from that of sulfoxides in solution. The method was applied to determine the organic sulfur compounds in hydrotreated transformer base oil.

  15. Sources and distribution of aliphatic and polyaromatic hydrocarbons in coastal sediments from the Ushuaia Bay (Tierra del Fuego, Patagonia, Argentina).

    PubMed

    Commendatore, Marta G; Nievas, Marina L; Amin, Oscar; Esteves, José L

    2012-03-01

    The environmental quality of Ushuaia Bay, located at the southernmost tip of South America, is affected by the anthropogenic pressure of Ushuaia city. In this study, levels and sources of hydrocarbons in coastal sediments were assessed. Aliphatic hydrocarbon fractions ranged between 5.5 and 1185.3 μg/g dry weight and PAHs from not detected to 360 ng/g. Aliphatic diagnostic indices, the nalkanes homologous series occurrence, Aliphatic Unresolved Complex Mixtures (AliUCMs), and pristane and phytane isoprenoids indicated a petrogenic input. Some sites showed biogenic features masked by the anthropogenic signature. Particularly in port areas biodegradation processes were evident. PAH ratios showed a mixture of petrogenic and pyrogenic sources. Aliphatic and aromatic UCMs were strongly correlated, reflecting chronic pollution. Three areas were distinguished inside the bay: (1) east, with low hydrocarbons impact; (2) central, where hydrocarbons accumulation was related to source proximity and sediment characteristics; (3) south-west, where sediment characteristics and current circulation favour hydrocarbons accumulation.

  16. Amperometric detection and electrochemical oxidation of aliphatic amines and ammonia on silver-lead oxide thin-film electrodes

    SciTech Connect

    Ge, Jisheng

    1996-01-08

    This thesis comprises three parts: Electrocatalysis of anodic oxygen-transfer reactions: aliphatic amines at mixed Ag-Pb oxide thin-film electrodes; oxidation of ammonia at anodized Ag-Pb eutectic alloy electrodes; and temperature effects on oxidation of ethylamine, alanine, and aquated ammonia.

  17. Aliphatic C-H to C-C Conversion: Synthesis of (−)-Cameroonan-7α-ol

    PubMed Central

    Taber, Douglass F.; Nelson, Christopher G.

    2011-01-01

    In the course of a synthesis of the tricyclic sesquiterpene (−)-cameroonan-7α-ol from the acyclic (+)-citronellal, seven aliphatic C-H bonds were converted to C-C bonds, and three rings and four new stereogenic centers were established. PMID:21344897

  18. Liquid-phase synthesis of bridged peptides using olefin metathesis of a protected peptide with a long aliphatic chain anchor.

    PubMed

    Aihara, Keisuke; Komiya, Chiaki; Shigenaga, Akira; Inokuma, Tsubasa; Takahashi, Daisuke; Otaka, Akira

    2015-02-06

    Bridged peptides including stapled peptides are attractive tools for regulating protein-protein interactions (PPIs). An effective synthetic methodology in a heterogeneous system for the preparation of these peptides using olefin metathesis and hydrogenation of protected peptides with a long aliphatic chain anchor is reported.

  19. Chemoselective hydroxylation of aliphatic sp3 C-H bonds using a ketone catalyst and aqueous H2O2.

    PubMed

    Pierce, Conor J; Hilinski, Michael K

    2014-12-19

    The first ketone-catalyzed method for the oxidation of aliphatic C-H bonds is reported. The reaction conditions employ aryl trifluoromethyl ketones in catalytic amounts and hydrogen peroxide as the terminal oxidant. Hydroxylation is stereospecific and chemoselective for tertiary over secondary C-H bonds. A catalytic cycle invoking a dioxirane as the active oxidant is proposed.

  20. 40 CFR 721.3830 - Formaldehyde, reaction products with an alkylated phenol and an aliphatic amine (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Formaldehyde, reaction products with... CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.3830 Formaldehyde, reaction..., reaction products with an alkylated phenol and an aliphatic amine (PMN P-99-0531) is subject to...

  1. 40 CFR 721.3830 - Formaldehyde, reaction products with an alkylated phenol and an aliphatic amine (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Formaldehyde, reaction products with... CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.3830 Formaldehyde, reaction..., reaction products with an alkylated phenol and an aliphatic amine (PMN P-99-0531) is subject to...

  2. 40 CFR 721.3830 - Formaldehyde, reaction products with an alkylated phenol and an aliphatic amine (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Formaldehyde, reaction products with... CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.3830 Formaldehyde, reaction..., reaction products with an alkylated phenol and an aliphatic amine (PMN P-99-0531) is subject to...

  3. 40 CFR 721.3830 - Formaldehyde, reaction products with an alkylated phenol and an aliphatic amine (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Formaldehyde, reaction products with... CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.3830 Formaldehyde, reaction..., reaction products with an alkylated phenol and an aliphatic amine (PMN P-99-0531) is subject to...

  4. Silver-mediated decarboxylative C-S cross-coupling of aliphatic carboxylic acids under mild conditions.

    PubMed

    Wang, Peng-Fei; Wang, Xiao-Qing; Dai, Jian-Jun; Feng, Yi-Si; Xu, Hua-Jian

    2014-09-05

    A silver-mediated decarboxylative C-S cross-coupling reaction of aliphatic carboxylic acid is described. This reaction occurs smoothly under mild conditions and shows good tolerance of functional groups. It provides an alternative approach for the synthesis of alkyl aryl sulfides.

  5. Proposed chemical mechanisms leading to secondary organic aerosol in the reactions of aliphatic amines with hydroxyl and nitrate radicals

    USDA-ARS?s Scientific Manuscript database

    The presence and importance of amines in the atmosphere continues to gain more attention including aliphatic amines commonly associated with agricultural facilities. The atmospheric reaction mechanisms of these amines with key atmospheric radicals are important to predict both daytime and nighttime...

  6. Patten recognition analysis of a set of mutagenic aliphatic N-nitrosamines

    SciTech Connect

    Nesnow, S.; Langenbach, R.; Mass, M.J.

    1985-09-01

    A set of 21 mutagenic aliphatic N-nitrosamines were subjected to a pattern recognition analysis using ADAPT software. Four descriptors based on molecular connectivity, geometry and sigma charge on nitrogen were capable of achieving a 100% classification using the linear learning machine or iterative least squares algorithms. Three descriptors were capable of a 90.5% and two descriptors of a 85.7% overall correct classification. Three of the four descriptors were each capable of classifying 15 of the 16 active chemicals while it required three of the four descriptors to classify correctly two of the five inactive chemicals. These results are in concert with previous observations that molecular connectivity, geometry, and sigma charge on nitrogen are powerful descriptors for separating active from inactive mutagenic and carcinogenic N-nitrosamines. 17 references, 1 figure, 5 tables.

  7. Synthesis and Characterization of Aromatic–Aliphatic Polyamide Nanocomposite Films Incorporating a Thermally Stable Organoclay

    PubMed Central

    2009-01-01

    Nanocomposites were synthesized from reactive thermally stable montmorillonite and aromatic–aliphatic polyamide obtained from 4-aminophenyl sulfone and sebacoyl chloride. Carbonyl chloride terminal chain ends were generated using 1% extra sebacoyl chloride that could interact chemically with the organoclay. The distribution of clay in the nanocomposites was investigated by XRD, SEM, and TEM. Mechanical and thermal properties of these materials were monitored using tensile testing, TGA, and DSC. The results revealed delaminated and intercalated nanostructures leading to improved tensile strength and modulus up to 6 wt% addition of organoclay. The elongation at break and toughness of the nanocomposites decreased with increasing clay contents. The nanocomposites were thermally stable in the range 400–450 °C. The glass transition temperature increased relative to the neat polyamide due to the interfacial interactions between the two phases. Water uptake of the hybrids decreased upon the addition of organoclay depicting reduced permeability. PMID:20596518

  8. Chemically responsive nanoporous pigments: colorimetric sensor arrays and the identification of aliphatic amines.

    PubMed

    Bang, Jin Ho; Lim, Sung H; Park, Erwin; Suslick, Kenneth S

    2008-11-18

    A general method has been developed for the preparation of microspheres of nanoporous pigments, their formulation into chemically responsive pigment inks, and the printing of these inks as colorimetric sensor arrays. Using an ultrasonic-spray aerosol-gel synthesis from chemically responsive dyes and common silica precursors, 16 different nanoporous pigment microspheres have been prepared and characterized. New colorimetric sensor arrays have been created by printing inks of these chemically responsive pigments as primary sensor elements; these arrays have been successfully tested for the detection, identification, and quantitation of toxic aliphatic amines. Among 11 structurally similar amines, complete identification of each analyte without confusion was achieved using hierarchical cluster analysis (HCA). Furthermore, visual identification of ammonia gas was easily made at the IDLH (immediately dangerous to life or health), PEL (permissible exposure limits), and 0.1 PEL concentrations with high reproducibility.

  9. Chemically Responsive Nanoporous Pigments: Colorimetric Sensor Arrays and the Identification of Aliphatic Amines

    PubMed Central

    Bang, Jin Ho; Lim, Sung H.; Park, Erwin; Suslick, Kenneth S.

    2008-01-01

    A general method has been developed for the preparation of microspheres of nanoporous pigments, their formulation into chemically responsive pigment inks, and the printing of these inks as calorimetric sensor arrays. Using an ultrasonic-spray aerosol–gel synthesis from chemically responsive dyes and common silica precursors, 16 different nanoporous pigment microspheres have been prepared and characterized. New calorimetric sensor arrays have been created by printing inks of these chemically responsive pigments as primary sensor elements; these arrays have been successfully tested for the detection, identification, and quantitation of toxic aliphatic amines. Among 11 structurally similar amines, complete identification of each analyte without confusion was achieved using hierarchical cluster analysis (HCA). Furthermore, visual identification of ammonia gas was easily made at the IDLH (immediately dangerous to life or health), PEL (permissible exposure limits), and 0.1 PEL concentrations with high reproducibility. PMID:18950204

  10. Investigation of Aromatic/Aliphatic Polyimides as Dispersants for Single Wall Carbon Nanotubes

    NASA Technical Reports Server (NTRS)

    Delozier, Donavon M.; Watson, Kent A.; Smith, Joseph G., Jr.; Clancy, Thomas C.; Connell, John W.

    2006-01-01

    Novel aromatic/aliphatic polyimides were prepared from 2,7-diamino-9,9'- dioctylfluorene (AFDA) and aromatic dianhydrides. Upon investigating the effectiveness of these polyimides for dispersing single wall carbon nanotubes (SWNTs) in solution, three were discovered to disperse SWNTs in N,N-dimethylacetamide (DMAc). Two of these polyimides, one from 3,3',4,4'-oxydiphthalic anhydride (ODPA) and one from symmetric 3,3',4,4'-biphenyltetracarboxylic dianhydride (s-BPDA), were used to prepare nanocomposites. Homogeneous polyimide/SWNT suspensions from both polymers were used in the preparation of films and fibers containing up to 1 wt% SWNTs. The samples were thermally treated to remove residual solvent and the films were characterized for SWNT dispersion by optical and high resolution scanning electron microscopy (HRSEM). Electrical and mechanical properties of the films were also determined. Electrospun fibers were examined by HRSEM to characterize SWNT alignment and orientation.

  11. Novel aliphatic lipid-based diesters for use in lubricant formulations: Structure property investigations

    NASA Astrophysics Data System (ADS)

    Raghunanan, Latchmi Cindy

    Structure-property relationships are increasingly valued for the identification of specifically engineered materials with properties optimized for targeted application(s). In this work, linear and branched diesters for use in lubricant formulations are prepared from lipid-based oleochemicals and their structure-property relationships reported. It is shown that the branched diesters possess exceptional physical property profiles, including suppression of crystallization, and are superior alternatives for use in lubricant formulations. For the linear aliphatic diesters, both high and low temperature properties were predictable functions of total chain length, and both were differently influenced by the fatty acid versus diol chain length. Symmetry did not influence either, although thermal stability decreased and thermal transition temperatures increased with increasing saturation. All of the linear diesters demonstrated Newtonian flow behaviour. Viscosity was also predictable as a function of total chain length; any microstructural features due to structural effects were superseded by mass effects.

  12. Temporary protection of metals against atmospheric corrosion by saturated straight chain aliphatic monocarboxylates. Mechanisms of inhibition

    SciTech Connect

    Kapin, C.; Steinmetz, P.; Steinmetz, J.

    1998-12-31

    This work was devoted to the investigations of the ability of saturated straight chain aliphatic monocarboxylates to inhibit corrosion of mild steel and zinc in aerated aqueous solutions. Performances of inhibitors were shown to be dependent on their chain length, their concentration and the immersion duration. Both crystallographic parameters and solubilities of iron and zinc carboxylates were determined. Then potential-pH diagrams of iron and zinc in water were built taking the presence of metallic soaps into account. According to these diagrams, the passivation of metals was attributed to the growth of films containing metallic soaps. This model confirms that previously proposed for inhibition of copper and magnesium by the same carboxylates.

  13. A nitrilase from a metagenomic library acts regioselectively on aliphatic dinitriles.

    PubMed

    Bayer, Sally; Birkemeyer, Claudia; Ballschmiter, Meike

    2011-01-01

    Several novel nitrilases were selected from metagenomic libraries using cinnamonitrile and a mixture of six different nitriles as substrates. The nitrilase gene nit1 was expressed in Escherichia coli and the resulting protein was further examined concerning its biochemical properties. Nit1 turned out to be an aliphatic nitrilase favoring dinitriles over mononitriles. Stereochemical analysis revealed that Nit1 converted the dinitrile 2-methylglutaronitrile regioselectively. Hydrolysis at the ω-nitrile group of a dinitrile, such as catalyzed by Nit1, leads to ω-cyanocarboxylic acids, which are important precursors for chemical and pharmaceutical products. Nit1 metabolized 2-methylglutaronitrile to the corresponding ω-cyanocarboxylic acid 4-cyanopentanoic acid can be used for the production of the fine chemical 1,5-dimethyl-2-piperidone.

  14. Catalytic activity of carbon nanotubes in the conversion of aliphatic alcohols

    NASA Astrophysics Data System (ADS)

    Zhitnev, Yu. N.; Tveritinova, E. A.; Chernyak, S. A.; Savilov, S. V.; Lunin, V. V.

    2016-06-01

    Carbon nanotubes (CNTs) obtained via the catalytic pyrolysis of hexane at 750°C were studied as the catalysts in conversion of C2-C4 alcohols. The efficiency of CNTs as catalysts in dehydration and dehydrogenation of ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, and tert-butanol was studied by means of pulse microcatalysis. The surface and structural characteristics of CNTs are investigated via SEM, TEM, DTA, BET, and XPS. CNTs are shown to be effective catalysts in the conversion of alcohols and do not require additional oxidative treatment. The regularities of the conversion of aliphatic alcohols, related to the properties of the CNTs surface and the structure of the alcohols are identified.

  15. Amination of ω-Functionalized Aliphatic Primary Alcohols by a Biocatalytic Oxidation–Transamination Cascade

    PubMed Central

    Pickl, Mathias; Fuchs, Michael; Glueck, Silvia M; Faber, Kurt

    2015-01-01

    Amination of non-activated aliphatic fatty alcohols to the corresponding primary amines was achieved through a five-enzyme cascade reaction by coupling a long-chain alcohol oxidase from Aspergillus fumigatus (LCAO_Af) with a ω-transaminase from Chromobacterium violaceum (ω-TA_Cv). The alcohol was oxidized at the expense of molecular oxygen to yield the corresponding aldehyde, which was subsequently aminated by the PLP-dependent ω-TA to yield the final primary amine product. The overall cascade was optimized with respect to pH, O2 pressure, substrate concentration, decomposition of H2O2 (derived from alcohol oxidation), NADH regeneration, and biocatalyst ratio. The substrate scope of this concept was investigated under optimized conditions by using terminally functionalized C4–C11 fatty primary alcohols bearing halogen, alkyne, amino, hydroxy, thiol, and nitrile groups. PMID:26583050

  16. Amination of ω-Functionalized Aliphatic Primary Alcohols by a Biocatalytic Oxidation-Transamination Cascade.

    PubMed

    Pickl, Mathias; Fuchs, Michael; Glueck, Silvia M; Faber, Kurt

    2015-10-01

    Amination of non-activated aliphatic fatty alcohols to the corresponding primary amines was achieved through a five-enzyme cascade reaction by coupling a long-chain alcohol oxidase from Aspergillus fumigatus (LCAO_Af) with a ω-transaminase from Chromobacterium violaceum (ω-TA_Cv). The alcohol was oxidized at the expense of molecular oxygen to yield the corresponding aldehyde, which was subsequently aminated by the PLP-dependent ω-TA to yield the final primary amine product. The overall cascade was optimized with respect to pH, O2 pressure, substrate concentration, decomposition of H2O2 (derived from alcohol oxidation), NADH regeneration, and biocatalyst ratio. The substrate scope of this concept was investigated under optimized conditions by using terminally functionalized C4-C11 fatty primary alcohols bearing halogen, alkyne, amino, hydroxy, thiol, and nitrile groups.

  17. Influence of some aliphatic alcohols on the metabolism of rat liver slices

    PubMed Central

    Forsander, Olof A.

    1967-01-01

    The influence of some aliphatic alcohols on oxygen uptake, carbon dioxide production, acid formation and lactate and pyruvate concentrations of rat liver slices was studied. At the concentrations used, none of the alcohols was found to influence oxygen uptake. Of the alcohols that are not oxidized by liver alcohol dehydrogenase, methanol increased carbon dioxide production, propan-2-ol decreased it and 2-methylpropan-2-ol was without influence. All the alcohols that are oxidized by the enzyme strongly decreased carbon dioxide production. The alcohols that are not oxidized had no marked effect on the lactate/pyruvate concentration ratio, whereas the other alcohols strongly increased the ratio. A highly significant correlation was found between the effects of the alcohol on pyruvate concentration and carbon dioxide production. It is assumed that the shift in the redox potential inhibits the function of the tricarboxylic acid cycle of the liver. PMID:6060455

  18. Aliphatic polyurethane-silica nanocomposites prepared by the parallel synthesis: Morphology and mechanical characteristics

    NASA Astrophysics Data System (ADS)

    Gofman, I. V.; Sukhanova, T. E.; Vylegzhanina, M. É.; Abalov, I. V.; Stepanova, I. S.; Trofimov, A. E.; Ten'kovtsev, A. V.

    2010-03-01

    Films of aliphatic polyurethane-silica composites containing up to 27.3 mol % of SiO2 nanoparticles have been prepared by the parallel synthesis using the sol-gel technology. It has been revealed that the variations in the mechanical properties of these materials with increasing concentration of nanoparticles exhibit a nontrivial behavior: the ultimate strain gradually increases, whereas the elastic modulus and the yield stress decrease. A correlation of the changes observed in the mechanical characteristics with an increase in the free volume of the material with increasing silica concentration has been established. Atomic-force microscopy has confirmed the existence of a developed system of nanopores with characteristic sizes from 15 to 100 nm in the materials under investigation.

  19. Aliphatic hydrocarbons in sediment cores from the southern basin of Lake Michigan

    SciTech Connect

    Doskey, P.V.; Andren, A.W.

    1991-10-01

    Aliphatic hydrocarbons in sediments of the southern basin of Lake Michigan have planktonic, terrigenous, and petroleum residue origins. Surficial sediments collected near the eastern shore in 60-80 m of water contained more petroleum residue and planktonic hydrocarbons and exhibited less terrigenous character than sediments collected from the deepest location in the basin. Petroleum residue inputs have increased since 1900 as evidenced by a change in the flux of an unresolved complex mixture (UCM) of hydrocarbons from 6 ng/cm{sup 2}{center_dot}yr to a flux of approximately 100 ng/cm{sup 2}{center_dot}yr in 1980. Sediment profiles of the UCM exhibited subsurface concentration maxima that may be due to reduced inputs of combustion products or feeding by oligochaetes. Profiles of n-C{sub l7} and pristane indicated that planktonic n-alkanes undergo degradation in the aerobic, mixed zone of the sediments.

  20. Recommended Correlations for the Surface Tension of Aliphatic, Carboxylic, and Polyfunctional Organic Acids

    NASA Astrophysics Data System (ADS)

    Mulero, A.; Cachadiña, I.; Sanjuán, E. L.

    2016-09-01

    In previous papers, we have proposed specific correlations to reproduce the surface tension values for several sets of fluids and for wide ranges of temperatures. In this paper, we focus our attention on organic fatty (aliphatic, carboxylic, and polyfunctional) acids. We have taken into account the available data and values in the DIPPR and DETHERM databases and also Wohlfarth and Wohlfarth's (1997) book. In some cases we have also considered new data published elsewhere. All the data and values have been carefully filtered and subsequently fitted with the use of the model currently implemented in NIST's REFPROP program, calculating two or four adjustable coefficients for each fluid. As a result, we propose recommended correlations for 99 acids, providing mean absolute percentage deviations below 1.6% in all cases.

  1. Clickable degradable aliphatic polyesters via copolymerization with alkyne epoxy esters: synthesis and postfunctionalization with organic dyes.

    PubMed

    Teske, Nele S; Voigt, Julia; Shastri, V Prasad

    2014-07-23

    Degradable aliphatic polyesters are the cornerstones of nanoparticle (NP)-based therapeutics. In this paradigm, covalent modification of the NP with cell-targeting motifs and dyes can aid in guiding the NP to its destination and gaining visual confirmation. Therefore, strategies to impart chemistries along the polymer backbone that are amenable to easy modification, such as 1,3-dipolar cycloaddition of an azide to an alkyne (the "click reaction"), could be significant. Here we present a simple and efficient way to introduce alkyne groups at high density in aliphatic polyesters without compromising their crystallinity via the copolymerization of cyclic lactones with propargyl 3-methylpentenoate oxide (PMPO). Copolymers of lactic acid and ε-caprolactone with PMPO were synthesized with up to 9 mol % alkyne content, and accessibility of the alkyne groups to the click reaction was demonstrated using several dyes commonly employed in fluorescence microscopy and imaging (Cy3, ATTO-740, and coumarin 343). In order to establish the suitability of these copolymers as nanocarriers, copolymers were formulated into NPs, and cytocompatibility, cellular uptake, and visualization studies undertaken in HeLa cells. Dye-modified NPs exhibited no quenching, remained stable in solution for at least 10 days, showed no cytotoxicity, and were readily taken up by HeLa cells. Furthermore, in addition to enabling the incorporation of multiple fluorophores within the same NP through blending of individual dye-modified copolymers, dye-modified polyesters offer advantages over physical entrapment of dye, including improved signal to noise ratio and localization of the fluorescence signal within cells, and possess the necessary prerequisites for drug delivery and imaging.

  2. The tip and hidden part of the iceberg: Proteinogenic and non-proteinogenic aliphatic amino acids.

    PubMed

    Fichtner, Maximilian; Voigt, Kerstin; Schuster, Stefan

    2017-01-01

    Amino acids are the essential building blocks of proteins and, therefore, living organisms. While the focus often lies on the canonical or proteinogenic amino acids, there is also a large number of non-canonical amino acids to explore. Some of them are part of toxins or antibiotics in fungi, bacteria or animals (e.g. sponges). Some others operate at the translational level like an "undercover agent". Here we give an overview of natural aliphatic amino acids, up to a side chain length of five carbons, without rings and with an unmodified backbone, and have a closer look on each of them. Some of them are dehydro amino acids with double or even triple bonds. Moreover, we outline mathematical methods for enumerating the complete list of all potential aliphatic amino acids of a given chain length. This should be of interest for synthetic biology. Most non-proteinogenic amino acids are found within fungi, with particularly many produced by Amanita species as defence chemicals. Several are incorporated into peptide antibiotics. Some of the amino acids occur due to broad substrate specificity of the branched-chain amino acid synthesis pathways. A large variety of amino acids were also found in the Murchison meteorite. Non-proteinogenic amino acids are of interest for numerous medical applications: discovery of new antibiotics, support in designing synthetic antibiotics, improvement of protein and peptide pharmaceuticals by avoiding incorporation of non-canonical amino acids, study of toxic cyanobacteria and other applications. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Occurrence of selected aliphatic amines in source water of major cities in China.

    PubMed

    Zhang, Haifeng; Ren, Shuoyi; Yu, Jianwei; Yang, Min

    2012-01-01

    The formation of toxic nitrogenous disinfection byproducts (N-DBPs), such as nitrosamines, halonitromethanes and haloacetonitriles, from reactions between chlorine/chloramine and dissolved organic nitrogen in drinking water has caused great concern with regarding public health. This study revealed the occurrence of 17 aliphatic amines, some of which have been confirmed to be the precursors of N-DBPs, in source water across China. A sensitive method based on benzenesulfonyl chloride derivatization and liquid-liquid extraction followed by GC-MS analysis was established for the simultaneous analysis of the selected amines in aqueous samples. In total, 37 source water samples from the capital cities of 20 provinces were collected for the survey. Among the 17 amines, 14 were detected with an average frequency of detection of 36%. The most relevant amines in terms of frequency and maximum concentrations detected were dimethylamine (100%, 24.82 microg/L), methylamine (78%, 0.92 microg/L), N-methylethylamine (70%, 8.84 microg/L), propylamine (59%, 10.69 microg/L), diethylamine (54%, 3.76 microg/L), N-methylbutylamine (35%, 3.07 microg/L), N-ethylpropylamine (35%, 0.52 microg/L), and piperidine (32%, 2.35 microg/L). This is the first large scale survey of the aliphatic amines occurrence in source water in the world. The wide presence of nitrosamine precursors like dimethylamine, N-methylethylamine and diethylamine, and the precursors of haloacetonitriles and halonitromethanes like methylamine and propylamine suggests that better source water management is required to ensure the safety of drinking water.

  4. Enzymatic Degradation of Aromatic and Aliphatic Polyesters by P. pastoris Expressed Cutinase 1 from Thermobifida cellulosilytica

    PubMed Central

    Gamerith, Caroline; Vastano, Marco; Ghorbanpour, Sahar M.; Zitzenbacher, Sabine; Ribitsch, Doris; Zumstein, Michael T.; Sander, Michael; Herrero Acero, Enrique; Pellis, Alessandro; Guebitz, Georg M.

    2017-01-01

    To study hydrolysis of aromatic and aliphatic polyesters cutinase 1 from Thermobifida cellulosilytica (Thc_Cut1) was expressed in P. pastoris. No significant differences between the expression of native Thc_Cut1 and of two glycosylation site knock out mutants (Thc_Cut1_koAsn and Thc_Cut1_koST) concerning the total extracellular protein concentration and volumetric activity were observed. Hydrolysis of poly(ethylene terephthalate) (PET) was shown for all three enzymes based on quantification of released products by HPLC and similar concentrations of released terephthalic acid (TPA) and mono(2-hydroxyethyl) terephthalate (MHET) were detected for all enzymes. Both tested aliphatic polyesters poly(butylene succinate) (PBS) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) were hydrolyzed by Thc_Cut1 and Thc_Cut1_koST, although PBS was hydrolyzed to significantly higher extent than PHBV. These findings were also confirmed via quartz crystal microbalance (QCM) analysis; for PHBV only a small mass change was observed while the mass of PBS thin films decreased by 93% upon enzymatic hydrolysis with Thc_Cut1. Although both enzymes led to similar concentrations of released products upon hydrolysis of PET and PHBV, Thc_Cut1_koST was found to be significantly more active on PBS than the native Thc_Cut1. Hydrolysis of PBS films by Thc_Cut1 and Thc_Cut1_koST was followed by weight loss and scanning electron microscopy (SEM). Within 96 h of hydrolysis up to 92 and 41% of weight loss were detected with Thc_Cut1_koST and Thc_Cut1, respectively. Furthermore, SEM characterization of PBS films clearly showed that enzyme tretment resulted in morphological changes of the film surface. PMID:28596765

  5. Olfactory sensitivity and odor structure-activity relationships for aliphatic ketones in CD-1 mice.

    PubMed

    Laska, Matthias

    2014-06-01

    Using a conditioning paradigm, the olfactory sensitivity of CD-1 mice for a homologous series of aliphatic 2-ketones (2-butanone to 2-nonanone) and several of their isomeric forms was investigated. With all 11 odorants, the animals significantly discriminated concentrations as low as 0.01 ppm (parts per million) from the solvent, and with two odorants (2-octanone and 5-nonanone), the best-scoring animals even detected concentrations as low as 3 ppt (parts per trillion). Analysis of odor structure-activity relationships showed that the correlation between olfactory detection thresholds of the mice for the 2-ketones and carbon chain length can best be described as a U-shaped function with the lowest threshold values at 2-octanone. Similarly, the correlation between olfactory sensitivity and carbon chain length of symmetrical ketones (3-pentanone to 6-undecanone) can best be described as a U-shaped function. In contrast, no significant correlation was found between olfactory detection thresholds of the mice and position of the functional carbonyl group attached to a C7 backbone. A comparison between the olfactory detection thresholds obtained here with those obtained in earlier studies suggests that mice are significantly more sensitive for 2-ketones than for n-carboxylic acids of the same carbon chain length. Across-species comparisons suggest that mice are significantly more sensitive for aliphatic ketones than squirrel monkeys and pigtail macaques, whereas the ranges of human olfactory detection threshold values overlap with those of the mice with seven of the 11 ketones tested. Further comparisons suggest that odor structure-activity relationships are both substance class and species specific. © The Author 2014. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  6. Effects of aliphatic aldehydes on the growth and patulin production of Penicillium expansum in apple juice.

    PubMed

    Taguchi, Tomoyasu; Kozutsumi, Daisuke; Nakamura, Ruka; Sato, Yoshio; Ishihara, Atsushi; Nakajima, Hiromitsu

    2013-01-01

    The effects of 16 aliphatic aldehydes with 3-10 carbons on the growth and patulin production of Penicillium expansum were examined. When P. expansum spores were inoculated into apple juice broth, some alkenals, including 2-propenal, (E)-2-butenal, (E)-2-pentenal, and (E)-2-hexenal, inhibited fungal growth and patulin production. Their minimal inhibitory concentrations were 5, 50, 80, and 80 µg/mL respectively. Vital staining indicated that these alkenals killed mycelia within 4 h. Treatment of the spores with these aldehydes also resulted in rapid loss of germination ability, within 0.5-2 d. On the other hand, aliphatic aldehydes with 8-10 carbons significantly enhanced patulin production without affecting fungal growth: 300 µg/mL of octanal and 100 µg/mL of (E)-2-octenal increased the patulin concentrations in the culture broth by as much as 8.6- and 7.8-fold as compared to that of the control culture respectively. The expression of the genes involved in patulin biosynthesis in P. expansum was investigated in mycelia cultured in apple juice broth containing 300 µg/mL of octanal for 3.5, 5, and 7 d. Transcription of the msas gene, encoding 6-methylsalicylic acid synthase, which catalyzed the first step in the patulin biosynthetic pathway was remarkably high in the 3.5-d and 5-d-old cultures as compared with the control. However, octanal did not any increase the transcription of the msas in the 7-d-old culture or that of the other two genes, IDH and the peab1, in culture. Thus the enhanced patulin accumulation with supplementation with these aldehydes is attributable to the increased amount of the msas transcript.

  7. Impact ionisation spectra from hypervelocity impacts using aliphatic poly(methyl methacrylate) microparticle projectiles.

    PubMed

    Burchell, Mark J; Armes, Steven P

    2011-02-28

    We report impact ionisation spectra from spherical poly(methyl methacrylate) (PMMA) microparticles of 724 nm diameter impacting a rhodium target. These projectiles were coated with an ultrathin (~11 nm) overlayer of polypyrrole, an electrically conducting organic polymer; this enabled the accumulation of sufficient surface charge to allow electrostatic acceleration up to speeds of 4 to 8 km s(-1) using a high-voltage Van de Graaff instrument. A grid above the target (held at 3.33 kV cm(-1) with respect to the target) accelerated the cations that were generated during the hypervelocity impacts, and these ions then drifted to a charge detector. By measuring the collected charge vs. time and assuming only single ionisation events, time-of-flight mass spectra were obtained. Strong signals were observed for cationic species with ions of m/z 41, 65 and 115. There were also minor contributions from cations with masses ranging from m/z 29 to 142. The three major signals are assigned to fragment ions (C(3)H(5)(+), C(4)H(5)O(+)/C(5)H(9)(+) and C(6)H(11)O(2)(+)) which are known to be associated with the decomposition of PMMA. These impact ionisation spectra differ significantly from those reported earlier using polystyrene (PS) microparticles. The aliphatic PMMA microparticles generate small (m/z <100) fragment ions more readily at lower speeds than the predominantly aromatic PS microparticles, where speeds of at least 10 km s(-1) are typically required for substantial yields of low-mass fragment ions. This correlates well with the well-known greater chemical and thermal fragility of PMMA compared to PS. The PMMA microparticles should prove useful synthetic mimics for aliphatic carbonaceous micrometeorites. Copyright © 2011 John Wiley & Sons, Ltd.

  8. Aliphatic and aromatic plant biopolymer dynamics in soil particles isolated from sequential density fractionation

    NASA Astrophysics Data System (ADS)

    Caldwell, B.; Filley, T.; Sollins, P.; Lajtha, K.; Swanston, C.; Kleber, M.; Kramer, M.

    2007-12-01

    A recent multi-layer-based soil organic matter-mineral interaction mechanistic model to describe the nature of soil organic matter-mineral surface mechanism for soil organic matter stabilization predicts that proteinaceous and aliphatic materials establish the core of strong binding-interactions upon which other organic matter is layered. A key methodology providing data underpinning this hypothesis is sequential density fractionation where soil is partitioned into particles of increasing density with the assumption that a partial control on organic matter distribution through density series is the thickness of its layering. Four soils of varying mineralogy and texture were investigated for their biopolymer, isotopic, and mineralogical properties. Light fractions (<1.8 g/cm3), although dominanted by organic detritus, did not always contain the highest concentration of lignin and substituted fatty acids from cutin and suberin while heavier fractions, 1.8-2.6 g/cm3, exhibited a progressive decrease in concentration in plant derived biopolymers with density. Extractable lignin phenols exhibited a progressive oxidation state with density. The concentration of biopolymers roughly mirrored the C:N ratio of soil particles which dropped consistently with increasing particle density. Although, in all soils, both lignin phenols and SFA concentration generally decreased with increasing density the ratio SFA/lignin varied with density and depending upon the soil. All soils, except the oxisol, exhibited an increase in SFA with respect to lignin suggesting a selective stabilization of those material with respect to lignin. In the oxisol, which showed little variation in its hematite dominated mineralogy across density, SFA/lignin remained constant, potentially indicating a greater capacity to stabilize lignin in that system. Interestingly, the lignin oxidation state increased with density in the oxisol. Given the variation in soil character, the consistency in these trends it

  9. Probing the Reactivity of Dimethylsulfoxonium Methylide with Conjugated and Nonconjugated Carbonyl Compounds: An Undergraduate Experiment Combining Synthesis, Spectral Analysis, and Mechanistic Discovery

    ERIC Educational Resources Information Center

    Ciaccio, James A.; Guevara, Elena L.; Alam, Rabeka; D'agrosa, Christina D.

    2010-01-01

    We introduce students to dimethylsulfoxonium methylide (DMSY) epoxidation of aryl and nonconjugated aliphatic aldehydes and ketones without revealing that DMSY cyclopropanates enones by Michael-initiated ring closure (MIRC). Each student performs the reaction of DMSY with one of nine carbonyl compounds, including four enones, and then analyzes the…

  10. Probing the Reactivity of Dimethylsulfoxonium Methylide with Conjugated and Nonconjugated Carbonyl Compounds: An Undergraduate Experiment Combining Synthesis, Spectral Analysis, and Mechanistic Discovery

    ERIC Educational Resources Information Center

    Ciaccio, James A.; Guevara, Elena L.; Alam, Rabeka; D'agrosa, Christina D.

    2010-01-01

    We introduce students to dimethylsulfoxonium methylide (DMSY) epoxidation of aryl and nonconjugated aliphatic aldehydes and ketones without revealing that DMSY cyclopropanates enones by Michael-initiated ring closure (MIRC). Each student performs the reaction of DMSY with one of nine carbonyl compounds, including four enones, and then analyzes the…

  11. AIM and NBO analyses of N-N rotational barrier in monocyclic nitrosamine compounds

    NASA Astrophysics Data System (ADS)

    Roohi, H.; Ebrahimi, A.; Alirezapoor, F.; Hajealirezahi, M.

    2005-06-01

    The rotational barrier in monocyclic aliphatic nitroseamines has been examined with the aid of topological theory of atoms in molecules and Weinhold's natural bond orbital (NBO) analyses. In addition, due to the similarity of the structures of nitrosamines and amides, we have compared the origin of the rotational barrier in nitrosoamine NH 2NO and formamide NH 2CHO compounds. A good correlation between the structural parameters, NBO results, and the properties of charge density has been found.

  12. The synthesis of organic and inorganic compounds in evolved stars.

    PubMed

    Kwok, Sun

    2004-08-26

    Recent isotopic analysis of meteorites and interplanetary dust has identified solid-state materials of pre-solar origin. We can now trace the origin of these inorganic grains to the circumstellar envelopes of evolved stars. Moreover, organic (aromatic and aliphatic) compounds have been detected in proto-planetary nebulae and planetary nebulae, which are the descendants of carbon stars. This implies that molecular synthesis is actively happening in the circumstellar environment on timescales as short as several hundred years. The detection of stellar grains in the Solar System suggests that they can survive their journey through the interstellar medium and that they are a major contributor of interstellar grains.

  13. Compounds in airborne particulates - Salts and hydrocarbons. [at Cleveland, OH

    NASA Technical Reports Server (NTRS)

    King, R. B.; Antoine, A. C.; Fordyce, J. S.; Neustadter, H. E.; Leibecki, H. F.

    1977-01-01

    Concentrations of 10 polycyclic aromatic hydrocarbons (PAH), the aliphatics as a group, sulfate, nitrate, fluoride, acidity, and carbon in the airborne particulate matter were measured at 16 sites in Cleveland, OH over a 1-year period during 1971 and 1972. Analytical methods used included gas chromatography, colorimetry, and combustion techniques. Uncertainties in the concentrations associated with the sampling procedures, and the analytical methods are evaluated. The data are discussed relative to other studies and source origins. High concentrations downwind of coke ovens for 3,4 benzopyrene are discussed. Hydrocarbon correlation studies indicated no significant relations among compounds studied.

  14. Compounds in airborne particulates - Salts and hydrocarbons. [at Cleveland, OH

    NASA Technical Reports Server (NTRS)

    King, R. B.; Antoine, A. C.; Fordyce, J. S.; Neustadter, H. E.; Leibecki, H. F.

    1977-01-01

    Concentrations of 10 polycyclic aromatic hydrocarbons (PAH), the aliphatics as a group, sulfate, nitrate, fluoride, acidity, and carbon in the airborne particulate matter were measured at 16 sites in Cleveland, OH over a 1-year period during 1971 and 1972. Analytical methods used included gas chromatography, colorimetry, and combustion techniques. Uncertainties in the concentrations associated with the sampling procedures, and the analytical methods are evaluated. The data are discussed relative to other studies and source origins. High concentrations downwind of coke ovens for 3,4 benzopyrene are discussed. Hydrocarbon correlation studies indicated no significant relations among compounds studied.

  15. Multipurpose Compound

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Specially formulated derivatives of an unusual basic compound known as Alcide may be the answer to effective treatment and prevention of the disease bovine mastitis, a bacterial inflammation of a cow's mammary gland that results in loss of milk production and in extreme cases, death. Manufactured by Alcide Corporation the Alcide compound has killed all tested bacteria, virus and fungi, shortly after contact, with minimal toxic effects on humans or animals. Alcide Corporation credits the existence of the mastitis treatment/prevention products to assistance provided the company by NERAC, Inc.

  16. Speciation of volatile organic compounds from poultry production

    NASA Astrophysics Data System (ADS)

    Trabue, Steven; Scoggin, Kenwood; Li, Hong; Burns, Robert; Xin, Hongwei; Hatfield, Jerry

    2010-09-01

    Volatile organic compounds (VOCs) emitted from poultry production are leading source of air quality problems. However, little is known about the speciation and levels of VOCs from poultry production. The objective of this study was the speciation of VOCs from a poultry facility using evacuated canisters and sorbent tubes. Samples were taken during active poultry production cycle and between production cycles. Levels of VOCs were highest in areas with birds and the compounds in those areas had a higher percentage of polar compounds (89%) compared to aliphatic hydrocarbons (2.2%). In areas without birds, levels of VOCs were 1/3 those with birds present and compounds had a higher total percentage of aliphatic hydrocarbons (25%). Of the VOCs quantified in this study, no single sampling method was capable of quantifying more than 55% of compounds and in several sections of the building each sampling method quantified less than 50% of the quantifiable VOCs. Key classes of chemicals quantified using evacuated canisters included both alcohols and ketones, while sorbent tube samples included volatile fatty acids and ketones. The top five compounds made up close to 70% of VOCs and included: 1) acetic acid (830.1 μg m -3); 2) 2,3-butanedione (680.6 μg m -3); 3) methanol (195.8 μg m -3); 4) acetone (104.6 μg m -3); and 5) ethanol (101.9 μg m -3). Location variations for top five compounds averaged 49.5% in each section of the building and averaged 87% for the entire building.

  17. Water and solute permeabilities of Arabidopsis roots in relation to the amount and composition of aliphatic suberin

    PubMed Central

    Ranathunge, Kosala; Schreiber, Lukas

    2011-01-01

    Although it is implied that suberized apoplastic barriers of roots negatively correlate with water and solute permeabilities, direct transport measurements across roots with altered amounts and compositions of aliphatic suberin are scarce. In the present study, hydroponically grown Arabidopsis wild types (Col8 and Col0) and different suberin mutants with altered amounts and/or compositions (horst, esb1-1, and esb1-2) were used to test this hypothesis. Detailed histochemical studies revealed late development of Casparian bands and suberin lamellae in the horst mutant compared with wild types and esb mutants. Suberin analysis with gas chromatography and mass spectrometry (GC-MS) showed that the horst mutant had ∼33% lower amounts of aliphatic monomers than Col8 and Col0. In contrast, enhanced suberin mutants (esb1-1 and esb1-2) had twice the amount of suberin as the wild types. Correlative permeability measurements, which were carried out for the first time with a root pressure probe for Arabidopsis, revealed that the hydraulic conductivity (Lpr) and NaCl permeability (Psr) of the whole root system of the horst mutant were markedly greater than in the respective wild types. This was reflected by the total amounts of aliphatic suberin determined in the roots. However, increased levels of aliphatic suberin in esb mutants failed to reduce either water or NaCl permeabilities below those of the wild types. It was concluded that the simple view and the conventional assumption that the amount of root suberin negatively correlates with permeability may not always be true. The aliphatic monomer arrangement in the suberin biopolymer and its microstructure also play a role in apoplastic barrier formation. PMID:21421706

  18. Perfluorinated Compounds

    EPA Science Inventory

    Perfluorinated compounds such as the perfluoroalkyl acids (PFAAs) and their derivatives are important man-made chemicals that have wide consumer and industrial applications. They are relatively contemporary chemicals, being in use only since the 1950s, and until recently, have be...

  19. Perfluorinated Compounds

    EPA Science Inventory

    Perfluorinated compounds such as the perfluoroalkyl acids (PFAAs) and their derivatives are important man-made chemicals that have wide consumer and industrial applications. They are relatively contemporary chemicals, being in use only since the 1950s, and until recently, have be...

  20. Key odor impact compounds in three yeast extract pastes.

    PubMed

    Mahadevan, Kritika; Farmer, Linda

    2006-09-20

    Three types of yeast extract pastes from two different suppliers were compared. Compounds responsible for the key odors include 2-methyl-3-furanthiol, 2-methyl-3-methyldithiofuran, methional, 1-octen-3-one, dimethyltrisulphide together with a number of pyrazines, thiophenes, and aliphatic compounds. The three types of yeast extract paste differed in the intensity of their main odors and, in particular, those caused by furans, furanthiols, and heterocyclic sulfur compounds. Not only do pastes from different suppliers differ in terms of odor volatiles, but so do different treatments and batches of yeast extract from one supplier. The results suggest that normal variations in the concentrations of precursors and processing conditions may cause variations in the flavor of the end product.

  1. Oxidation of aliphatic, branched chain, and aromatic hydrocarbons by Nocardia cyriacigeorgica isolated from oil-polluted sand samples collected in the Saudi Arabian Desert.

    PubMed

    Le, Thi Nhi-Cong; Mikolasch, Annett; Awe, Susanne; Sheikhany, Halah; Klenk, Hans-Peter; Schauer, Frieder

    2010-06-01

    A soil bacterium isolated from oil-polluted sand samples collected in the Saudi Arabian Desert has been determined as Nocardia cyriacigeorgica, which has a high capacity of degrading and utilizing a broad range of hydrocarbons. The metabolic pathways of three classes of hydrocarbons were elucidated by identifying metabolites in cell-free extracts analyzed by GC/MS and HPLC/UV-Vis in comparison with standard compounds. During tetradecane oxidation, tetradecanol; tetradecanoic acid; dodecanoic acid; decanoic acid could be found as metabolites, indicating a monoterminal degradation pathway of n -alkanes. The oxidation of pristane resulted in the presence of pristanoic acid; 2-methylglutaric acid; 4,8-dimethylnonanoic acid; and 2,6-dimethylheptanoic acid, which give rise to a possible mono- and di-terminal oxidation. In case of sec -octylbenzene, eight metabolites were detected including 5-phenylhexanoic acid; 3-phenylbutyric acid; 2-phenylpropionic acid; beta -methylcinnamic acid; acetophenone; beta -hydroxy acetophenone; 2,3-dihydroxy benzoic acid and succinic acid. From these intermediates a new degradation pathway for sec -octylbenzene was investigated. Our results indicate that N. cyriacigeorgica has the ability to degrade aliphatic and branched chain alkanes as well as alkylbenzene effectively and, therefore, N. cyriacigeorgica is probably a suitable bacterium for biodegradation of oil or petroleum products in contaminated soils.

  2. Isolation of a thermophilic bacterium, Geobacillus sp. SH-1, capable of degrading aliphatic hydrocarbons and naphthalene simultaneously, and identification of its naphthalene degrading pathway.

    PubMed

    Zhang, Jian; Zhang, Xu; Liu, Juan; Li, Rong; Shen, Biao

    2012-11-01

    A thermophilic naphthalene- and aliphatic hydrocarbon-degrading bacterium SH-1 was isolated from a deep oil well and identified as Geobacillus sp. n-alkanes from C12 to C33 in crude oil and naphthalene were effectively degraded by strain SH-1, and this strain could readily utilize these compounds as its sole carbon and energy resources. During the degradation of naphthalene, strain SH-1 initiated its attack on naphthalene by a monooxygenation at its C-1 to give 1-naphthol and further monooxygenation at C-2 to produce 1,2-dihydroxynaphthalene. The ring of 1,2-dihydroxynaphthalene was cleaved to form trans-o-hydroxybenzylidenepyruvate. Subsequently, trans-o-hydroxybenzylidenepyruvate was transformed to (2E)-3-(2-hydroxyphenyl)prop-2-enal by losing a carboxyl group. Additionally, benzoic acid was identified as an intermediate in the naphthalene degradation pathway of this Geobacillus strain. This study highlights an important potential use of the thermophilic degradative strain SH-1 in the cleanup of environmental contamination by naphthalene and crude oil and presents a mechanism for naphthalene metabolism. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. Magnesium compounds

    USGS Publications Warehouse

    Kramer, D.A.

    2003-01-01

    Seawater and natural brines accounted for about 60 percent of U.S. magnesium compounds production during 2002. Dead-burned and caustic-calcined magnesias were recovered from seawater by Premier Chemicals in Florida. They were also recovered from well brines in Michigan by Dow Chemical, Martin Marietta Magnesia Specialties and Rohm & Haas. And they were recovered from magnesite in Nevada by Premier Chemicals.

  4. Magnesium compounds

    USGS Publications Warehouse

    Kramer, D.A.

    2006-01-01

    In 2005, seawater and natural brines accounted for 51% of US magnesium compounds production. World magnesia production was estimated to be 14.5 Mt. Most of the production came from China, North Korea, Russia and Turkey. Although no specific production figures are available, Japan and the United States are estimated to account for almost one-half of the world's capacity from seawater and brines.

  5. Combined dispersive solid-phase extraction-dispersive liquid-liquid microextraction-derivatization for gas chromatography-mass spectrometric determination of aliphatic amines on atmospheric fine particles.

    PubMed

    Majedi, Seyed Mohammad; Lee, Hian Kee

    2017-02-24

    Short-chain aliphatic amines are ubiquitous in the atmospheric environment. They play an important role in the formation and growth of atmospheric particles. As such, there is a pressing need to monitor these particle-bound compounds present at trace quantities. The present work describes an efficient, one-step microextraction technique for the preconcentration and detection of trace levels of 10 aliphatic amines on fine particles (particulate matter of 2.5μm or less (PM2.5)) in the atmosphere. After extraction of amines from particles in acidified water samples, carbon-based sorbents (in dispersive solid-phase extraction mode), and vortex agitation were utilized for simultaneous derivatization-extraction and dispersive liquid-liquid microextraction. The approach significantly increased the recoveries and enrichment of the amine derivatives. This one-step, combined technique is proposed for the first time. Several influential factors including type and concentration of derivatization reagent (for gas chromatographic separation), type of buffer, sample pH, types and volumes of extraction and disperser solvents, type and amount of sorbent, vortex time and temperature, desorption solvent type and volume, and salt content were investigated and optimized. Under the optimum conditions, high enrichment factors (in the range of between 307 and 382) and good reproducibility (relative standard deviations, below 7.0%, n=5) were achieved. The linearity ranged from 0.1μg/L-100μg/L, and from 0.5μg/L-100μg/L, depending on the analytes. The limits of detection were between 0.02μg/L (corresponding to ∼0.01ng/m(3) in air) and 0.09μg/L (corresponding to ∼0.04ng/m(3) in air). The developed method was successfully applied to the analysis of PM2.5 samples collected by air sampling through polytetrafluoroethylene filters. The concentration levels of amines ranged from 1.04 to 4.16ng/m(3) in the air sampled.

  6. Polycyclic Aromatic Hydrocarbons with Aliphatic Sidegroups: Intensity Scaling for the C-H Stretching Modes and Astrophysical Implications

    NASA Astrophysics Data System (ADS)

    Yang, X. J.; Li, Aigen; Glaser, R.; Zhong, J. X.

    2017-03-01

    The so-called unidentified infrared emission (UIE) features at 3.3, 6.2, 7.7, 8.6, and 11.3 μ {{m}} ubiquitously seen in a wide variety of astrophysical regions are generally attributed to polycyclic aromatic hydrocarbon (PAH) molecules. Astronomical PAHs may have an aliphatic component, as revealed by the detection in many UIE sources of the aliphatic C-H stretching feature at 3.4 μ {{m}}. The ratio of the observed intensity of the 3.4 μ {{m}} feature to that of the 3.3 μ {{m}} aromatic C-H feature allows one to estimate the aliphatic fraction of the UIE carriers. This requires knowledge of the intrinsic oscillator strengths of the 3.3 μ {{m}} aromatic C-H stretch ({A}3.3) and the 3.4 μ {{m}} aliphatic C-H stretch ({A}3.4). Lacking experimental data on {A}3.3 and {A}3.4 for the UIE candidate materials, one often has to rely on quantum-chemical computations. Although the second-order Møller-Plesset (MP2) perturbation theory with a large basis set is more accurate than the B3LYP density functional theory, MP2 is computationally very demanding and impractical for large molecules. Based on methylated PAHs, we show here that, by scaling the band strengths computed at an inexpensive level (e.g., B3LYP/6-31G*), we are able to obtain band strengths as accurate as those computed at far more expensive levels (e.g., MP2/6-311+G(3df,3pd)). We calculate the model spectra of methylated PAHs and their cations excited by starlight of different spectral shapes and intensities. We find that {({I}3.4/{I}3.3)}{mod}, the ratio of the model intensity of the 3.4 μ {{m}} feature to that of the 3.3 μ {{m}} feature, is insensitive to the spectral shape and intensity of the exciting starlight. We derive a straightforward relation for determining the aliphatic fraction of the UIE carriers (i.e., the ratio of the number of C atoms in aliphatic units {N}{{C},{ali}} to that in aromatic rings {N}{{C},{aro}}) from the observed band ratios {({I}3.4/{I}3.3)}{obs}: {N

  7. Skin exposure to aliphatic polyisocyanates in the auto body repair and refinishing industry: a qualitative assessment.

    PubMed

    Liu, Youcheng; Bello, Dhimiter; Sparer, Judy A; Stowe, Meredith H; Gore, Rebecca J; Woskie, Susan R; Cullen, Mark R; Redlich, Carrie A

    2007-07-01

    Although respiratory exposures have been the primary concern with isocyanates, skin exposure also can occur and may contribute to sensitization and asthma. Methodologies to assess isocyanate skin exposure in the workplace are limited and skin exposure data scarce. The goals of this study were (i) to evaluate and validate the isocyanate colorimetric indicators against a quantitative assay, (ii) to evaluate the extent of isocyanate surface contamination and skin exposure among auto body shop workers and (iii) to evaluate isocyanate skin exposure determinants. The colorimetric indicators were compared with a high-performance liquid chromatography (HPLC) quantitative assay based on the National Institute for Occupational Safety and Health Method 5525 using paired laboratory sampling. The colorimetric indicators were then used to assess surface contamination and skin exposure to aliphatic isocyanates in 35 auto body shops and 124 workers as part of an epidemiologic study. The positive sample rate was calculated for various surfaces, body parts and tasks. The color intensity of the colorimetric indicators was rated on a scale 0 (yellow color) to 5 (deep red). Side-by-side comparisons of the qualitative method with the quantitative HPLC assay were also performed in the field using paired samples. Laboratory and field evaluation validated use of the colorimetric indicators. The rate of positive surface samples for isocyanates was 46% (n = 145/313). Thirty-four percent (73/216) of samples were positive for unprotected skin and 20% (n = 22/111) for skin under latex gloves. The highest positive rate observed on skin samples was obtained after paint mixing and spraying tasks. The colorimetric indicators were highly specific for isocyanates, but false negatives occurred when compared with the more sensitive HPLC quantitative assay. The presence of surface contamination and the performance of paint-related tasks were the major determinants of isocyanate skin exposure. This study

  8. Source apportionment of sediment-associated aliphatic hydrocarbon in a eutrophicated shallow lake, China.

    PubMed

    Wang, Ji-Zhong; Yang, Ze-Yu; Chen, Tian-Hu

    2012-11-01

    Chaohu Lake, one of the most eutrophicated lakes in China, has been suffering from long-term outside pollution, urban sewage, river outflows, and agricultural runoff which expectedly have been the main contributors of hydrocarbons. However, the contributions from these various sources have not been specified. The present study is aimed at identifying the potential sources of hydrocarbons in surface sediment around the whole lake and assessing the relative contributions using principal components analysis-multiple linear regression (PCA-MLR). Sixty-one surface sediments covering the whole Chaohu Lake and three main estuaries of inflowing rivers were collected, dried, extracted, and analyzed for 27 normal alkanes (n-alkanes, from C(12) to C(38), defined Σ(27)AH) and unresolved complex mixture (UCM) by GC/MS. Diagnostic ratios and PCA-MLR were utilized to apportion their sources. The concentrations of Σ(27)AH and UCM ranged from 434 to 3,870 ng/g and 11.9 to 325 μg/g dry weight, respectively, for all samples. The concentrations of Σ(27)AH in western region and estuary of Nanfei River were slightly higher but without statistical significance than those from eastern region and estuaries of Yuxi River and Hangbu River. The concentration of UCM from western region was significantly higher than that obtained from eastern region. These results reflect the importance of input of urban runoff by Nanfei River and serious eutrophication in western region. Aliphatic hydrocarbons in Chaohu Lake were mainly derived from high plant wax with mixed sources of phytoplankton and petroleum. Weak microbial decomposition of n-alkanes would be expected to occur from the low ratios of isoprenoid hydrocarbons pristine (pri) and phytane (phy) to n-C(17) and n-C(18), respectively. Higher plant, fossil combustion, petroleum residue, and phytoplankton were proposed as the main origines of aliphatic hydrocarbons by PCA while the contributions of individual n-alkane homologues, pri and phy

  9. Synthesis and biological evaluation of lovastatin-derived aliphatic hydroxamates that induce reactive oxygen species.

    PubMed

    Lin, Ruo-Kai; Lin, Yuh-Feng; Hsu, Ming-Jen; Hsieh, Chang-Lin; Wang, Chen-Yu; Huang, Chih-Chiang; Huang, Wei-Jan

    2016-11-15

    Some hydroxamate compounds induce cancer cell death by intracellular reactive oxygen species (ROS). This study introduced the hydroxamate core into lovastatin, a fungus metabolite clinically used for the treatment of hypercholesterolemia. The resulting compounds were evaluated for the activity for inducing ROS production. Most compounds exhibited higher activity than original lovastatin. Of these compounds, compound 3c had the most potent activity. Test of cytotoxicity in a panel of human cancer cell lines indicated compound 3c had activities superior to cisplatin in prostate cancer PC-3 cells and breast cancer T47D cells. In contrast, it in amounts up to 40μM had a much lower cytotoxic effect on normal human IMR-90 cells. Further profiling of cell cycle progression, cell apoptosis, and DNA damage activated checkpoint signaling pathway revealed the important role of compound 3c-mediated cytotoxicity in ROS generation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Magnesium compounds

    USGS Publications Warehouse

    Kramer, D.A.

    2011-01-01

    Seawater and natural brines accounted for about 54 percent of U.S. magnesium compounds production in 2010. Dead-burned magnesia was produced by Martin Marietta Magnesia Specialties from well brines in Michigan. Caustic-calcined magnesia was recovered from seawater by Premier Magnesia in Florida, from well brines in Michigan by Martin Marietta and from magnesite in Nevada by Premier Magnesia. Intrepid Potash-Wendover and Great Salt Lake Minerals Corp. recovered magnesium chloride brines from the Great Salt Lake in Utah. Magnesium hydroxide was produced from seawater by SPI Pharma in Delaware and Premier Magnesia in Florida, and by Martin Marietta from its operation mentioned above.

  11. Magnesium compounds

    USGS Publications Warehouse

    Kramer, D.A.

    2010-01-01

    Seawater and natural brines accounted for about 40 percent of U.S. magnesium compounds production in 2009. Dead-burned magnesia was produced by Martin Marietta Magnesia Specialties from well brines in Michigan. Caustic-calcined magnesia was recovered from seawater by Premier Chemicals in Florida, from well brines in Michigan by Martin Marietta and from magnesite in Nevada by Premier Chemicals. Intrepid Potash-Wendover, and Great Salt Lake Minerals Corp. recovered magnesium chloride brines from the Great Salt Lake in Utah. Magnesium hydroxide was produced from seawater by SPI Pharma in Delaware and Premier Chemicals in Florida, and by Martin Marietta from its operation mentioned above.

  12. Magnesium compounds

    USGS Publications Warehouse

    Kramer, D.A.

    2002-01-01

    Seawater and natural brines accounted for about 60% of US magnesium compounds production in 2001. Dead-burned and caustic-calcined magnesias were recovered from seawater in Florida by Premier Chemicals. They were also recovered from Michigan well brines by Dow Chemical, Martin Marietta Magnesia Specialties and Rohm & Haas. And Premier Chemicals recovered dead-burned and caustic-calcined magnesias from magnesite in Nevada. Reilly Industries and Great Salt Lake Minerals recovered magnesium chloride brines from the Great Salt Lake in Utah.

  13. Evaluation of the NIOSH draft method 5525 for determination of the total reactive isocyanate group (TRIG) for aliphatic isocyanates in autobody repair shops. National Institute for Occupational Safety and Health.

    PubMed

    Bello, D; Streicher, R P; Woskie, S R

    2002-06-01

    This paper evaluates the performance of the NIOSH draft method 5525 for analysis of monomeric and TRIG aliphatic isocyanates in autobody repair shops. It was found that an optimized pH gradient enhanced noticeably the resolution and, therefore, identification of aliphatic isocyanates. Samples proved to be very stable for at least a year when stored at -13 degrees C in the freezer, and no major stability problems were found for the MAP reagent. The detector response factor RSD for selected MAP ureas was 40% in the fluorescence (FLD), 3% in the UV at 254 nm (UV254), and 1% in the UV at 370 nm (UV370). The mean FLD/UV254 and UV254/UV370 detector response ratios of standards were 31.7 (RSD = 37.8) and 17.1 (RSD = 5.4), respectively. The FLD/UV254 ratio in bulks varied from 0.41 to 1.97 times the HDI monomer ratio. The mean UV254/UV370 ratio in bulks was 16.1 (range 14.1 to 19.2, N = 38). Mean (range) recovery of 92 (91.2-93.2)% was found for the N3300 (isocyanurate) spiked on 25 mm quartz fiber filters in the range 0.07 to 2.2 microg NCO ml(-1). Mean (range) recovery for impingers was 100.7 (91.7-106.0)% for N3300 in the concentration range of 0.018 to 2.5 microg NCO ml(-1) and 81.0 (76.1-89.1)% for IPDI in the concentration range of 0.016 to 1.87 microg NCO ml(-1). Analytical method precision was 3.4% and mean bias 7.4% (range = 0-25%). The NIOSH draft method 5525 provides flexibility, enhanced sensitivity and specificity, powerful resolution, and very small compound-to-compound variability in the UV254, resulting in a more reliable identification and quantification of aliphatic isocyanates.

  14. Topsoil drying combined with increased sulfur supply leads to enhanced aliphatic glucosinolates in Brassica juncea leaves and roots.

    PubMed

    Tong, Yu; Gabriel-Neumann, Elke; Ngwene, Benard; Krumbein, Angelika; George, Eckhard; Platz, Stefanie; Rohn, Sascha; Schreiner, Monika

    2014-01-01

    The decrease of water availability is leading to an urgent demand to reduce the plants' water supply. This study evaluates the effect of topsoil drying, combined with varying sulfur (S) supply on glucosinolates in Brassica juncea in order to reveal whether a partial root drying may already lead to a drought-induced glucosinolate increase promoted by an enhanced S supply. Without decreasing biomass, topsoil drying initiated an increase in aliphatic glucosinolates in leaves and in topsoil dried roots supported by increased S supply. Simultaneously, abscisic acid was determined, particularly in dehydrated roots, associated with an increased abscisic acid concentration in leaves under topsoil drying. This indicates that the dehydrated roots were the direct interface for the plants' stress response and that the drought-induced accumulation of aliphatic glucosinolates is related to abscisic acid formation. Indole and aromatic glucosinolates decreased, suggesting that these glucosinolates are less involved in the plants' response to drought.

  15. Hollow-fiber liquid-phase microextraction coupled with miniature capillary electrophoresis for the trace analysis of four aliphatic aldehydes in water samples.

    PubMed

    Li, Ying; Yi, Fan; Zheng, Yiliang; Wang, Yu; Ye, Jiannong; Chu, Qingcui

    2015-08-01

    An environmentally friendly method for the trace analysis of four aliphatic aldehydes as water disinfection byproducts has been developed based on hollow-fiber liquid-phase microextraction followed by miniature capillary electrophoresis with amperometric detection. After derivatization with 2-thiobarbituric acid, four aliphatic aldehydes (formaldehyde, acetaldehyde, propylaldehyde, and butyraldehyde) became detectable by the amperometric detector. Under the optimum conditions, four aliphatic aldehydes can be well separated from the coexisting interferents as well as their homologs (pentanal, glyoxal, and methyl-glyoxal), and the limits of detection (S/N = 3) could reach sub-nanogram-per-milliliter level based on hollow-fiber liquid-phase microextraction. The proposed method has been applied for the analyses of above four aliphatic aldehydes in different water samples such as drinking water, tap water, and river water, and the average recoveries were in the range of 90-113%, providing an alternative to conventional and microchip capillary electrophoresis approaches.

  16. Evidence that Additions of Grignard Reagents to Aliphatic Aldehydes Do Not Involve Single-Electron-Transfer Processes.

    PubMed

    Otte, Douglas A L; Woerpel, K A

    2015-08-07

    Addition of allylmagnesium reagents to an aliphatic aldehyde bearing a radical clock gave only addition products and no evidence of ring-opened products that would suggest single-electron-transfer reactions. The analogous Barbier reaction also did not provide evidence for a single-electron-transfer mechanism in the addition step. Other Grignard reagents (methyl-, vinyl-, t-Bu-, and triphenylmethylmagnesium halides) also do not appear to add to an alkyl aldehyde by a single-electron-transfer mechanism.

  17. IUPAC-NIST Solubility Data Series. 96. Amines with Water Part 2. C7-C24 Aliphatic Amines

    NASA Astrophysics Data System (ADS)

    Góral, Marian; Shaw, David G.; Måczyński, Andrzej; Wiśniewska-Gocłowska, Barbara; Oracz, Paweł

    2012-12-01

    The mutual solubilities and related liquid-liquid equilibria of 41 binary systems of C7-C24 aliphatic amines with water are exhaustively and critically reviewed. Reports of experimental determination of solubility that appeared in the primary literature prior to the end of 2010 are compiled. For seven systems, sufficient data are available to allow critical evaluation. All data are expressed as mass percent and mole fraction as well as the originally reported units.

  18. Aliphatic C-H bond oxidation of toluene using copper peroxo complexes that are stable at room temperature.

    PubMed

    Würtele, Christian; Sander, Ole; Lutz, Volker; Waitz, Thomas; Tuczek, Felix; Schindler, Siegfried

    2009-06-10

    Dinuclear copper peroxo complexes obtained from mononuclear copper(I) complexes showed extremely high stabilities under ambient conditions in the solid state and could be heated above 100 degrees C without decomposition. The increased stability could be explained with regard to their molecular structures. Furthermore, the four complexes investigated showed a high potential for aliphatic C-H bond oxidations: for example, technical-grade toluene was oxidized to benzaldehyde in yields of up to 20%.

  19. Sum frequency generation image reconstruction: Aliphatic membrane under spherical cap geometry

    SciTech Connect

    Volkov, Victor

    2014-10-07

    The article explores an opportunity to approach structural properties of phospholipid membranes using Sum Frequency Generation microscopy. To establish the principles of sum frequency generation image reconstruction in such systems, at first approach, we may adopt an idealistic spherical cap uniform assembly of hydrocarbon molecules. Quantum mechanical studies for decanoic acid (used here as a representative molecular system) provide necessary information on transition dipole moments and Raman tensors of the normal modes specific to methyl terminal – a typical moiety in aliphatic (and phospholipid) membranes. Relative degree of localization and frequencies of the normal modes of methyl terminals make nonlinearities of this moiety to be promising in structural analysis using Sum Frequency Generation imaging. Accordingly, the article describes derivations of relevant macroscopic nonlinearities and suggests a mapping procedure to translate amplitudes of the nonlinearities onto microscopy image plane according to geometry of spherical assembly, local molecular orientation, and optical geometry. Reconstructed images indicate a possibility to extract local curvature of bilayer envelopes of spherical character. This may have practical implications for structural extractions in membrane systems of practical relevance.

  20. Biological evaluation of porous aliphatic polyurethane/hydroxyapatite composite scaffolds for bone tissue engineering.

    PubMed

    Yang, Wanxun; Both, Sanne K; Zuo, Yi; Birgani, Zeinab Tahmasebi; Habibovic, Pamela; Li, Yubao; Jansen, John A; Yang, Fang

    2015-07-01

    Biomaterial scaffolds meant to function as supporting structures to osteogenic cells play a pivotal role in bone tissue engineering. Recently, we synthesized an aliphatic polyurethane (PU) scaffold via a foaming method using non-toxic components. Through this procedure a uniform interconnected porous structure was created. Furthermore, hydroxyapatite (HA) particles were introduced into this process to increase the bioactivity of the PU matrix. To evaluate the biological performances of these PU-based scaffolds, their influence on in vitro cellular behavior and in vivo bone forming capacity of the engineered cell-scaffold constructs was investigated in this study. A simulated body fluid test demonstrated that the incorporation of 40 wt % HA particles significantly promoted the biomineralization ability of the PU scaffolds. Enhanced in vitro proliferation and osteogenic differentiation of the seeded mesenchymal stem cells were also observed on the PU/HA composite. Next, the cell-scaffold constructs were implanted subcutaneously in a nude mice model. After 8 weeks, a considerable amount of vascularized bone tissue with initial marrow stroma development was generated in both PU and PU/HA40 scaffold. In conclusion, the PU/HA composite is a potential scaffold for bone regeneration applications.