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1
Islam, M. M. "Reaction of Aspartate Aminotransferase with C5-Dicarboxylic Acids: Comparison with the Reaction with C4-Dicarboxylic Acids". Journal of Biochemistry 134, nr 2 (1.08.2003): 277–85. http://dx.doi.org/10.1093/jb/mvg141.
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Soonsin, V., A. A. Zardini, C. Marcolli, A. Zuend i U. K. Krieger. "The vapor pressures and activities of dicarboxylic acids reconsidered: the impact of the physical state of the aerosol". Atmospheric Chemistry and Physics Discussions 10, nr 8 (27.08.2010): 20515–58. http://dx.doi.org/10.5194/acpd-10-20515-2010.
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Abstract. We present vapor pressure data of the C2 to C5 dicarboxylic acids deduced from measured evaporation rates of single levitated particles as both, aqueous droplets and solid crystals. The data of aqueous solution particles over a wide concentration range allow us to directly calculate activities of the dicarboxylic acids and comparison of these activities with parameterizations reported in the literature. The data of the pure liquid state acids, i.e. the dicarboxylic acids in their supercooled melt state, exhibit no even-odd alternation in vapor pressure, while the acids in the solid form do. This observation is consistent with the known solubilities of the acids and our measured vapor pressures of the supercooled melt. Thus, the gas/particle partitioning of the different dicarboxylic acids in the atmosphere depends strongly on the physical state of the aerosol phase, the difference being largest for the even acids. Our results show also that, in general, measurements of vapor pressures of solid dicarboxylic acids may be compromised by the presence of amorphous fractions, polymorphic forms, crystalline structures with a high defect number, and/or solvent inclusions in the solid material, yielding a higher vapor pressure than the one of the thermodynamically stable crystalline form at the same temperature.
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Soonsin, V., A. A. Zardini, C. Marcolli, A. Zuend i U. K. Krieger. "The vapor pressures and activities of dicarboxylic acids reconsidered: the impact of the physical state of the aerosol". Atmospheric Chemistry and Physics 10, nr 23 (10.12.2010): 11753–67. http://dx.doi.org/10.5194/acp-10-11753-2010.
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Abstract. We present vapor pressure data of the C2 to C5 dicarboxylic acids deduced from measured evaporation rates of single levitated particles as both, aqueous droplets and solid crystals. The data of aqueous solution particles over a wide concentration range allow us to directly calculate activities of the dicarboxylic acids and comparison of these activities with parameterizations reported in the literature. The data of the pure liquid state acids, i.e. the dicarboxylic acids in their supercooled melt state, exhibit no even-odd alternation in vapor pressure, while the acids in the solid form do. This observation is consistent with the known solubilities of the acids and our measured vapor pressures of the supercooled melt. Thus, the gas/particle partitioning of the different dicarboxylic acids in the atmosphere depends strongly on the physical state of the aerosol phase, the difference being largest for the even acids. Our results show also that, in general, measurements of vapor pressures of solid dicarboxylic acids may be compromised by the presence of polymorphic forms, crystalline structures with a high defect number, and/or solvent inclusions in the solid material, yielding a higher vapor pressure than the one of the thermodynamically stable crystalline form at the same temperature.
4
Sato, Kei, Fumikazu Ikemori, Sathiyamurthi Ramasamy, Akihiro Fushimi, Kimiyo Kumagai, Akihiro Iijima i Yu Morino. "Four- and Five-Carbon Dicarboxylic Acids Present in Secondary Organic Aerosol Produced from Anthropogenic and Biogenic Volatile Organic Compounds". Atmosphere 12, nr 12 (20.12.2021): 1703. http://dx.doi.org/10.3390/atmos12121703.
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To better understand precursors of dicarboxylic acids in ambient secondary organic aerosol (SOA), we studied C4–C9 dicarboxylic acids present in SOA formed from the oxidation of toluene, naphthalene, α-pinene, and isoprene. C4–C9 dicarboxylic acids present in SOA were analyzed by offline derivatization gas chromatography–mass spectrometry. We revealed that C4 dicarboxylic acids including succinic acid, maleic acid, fumaric acid, malic acid, DL-tartaric acid, and meso-tartaric acid are produced by the photooxidation of toluene. Since meso-tartaric acid barely occurs in nature, it is a potential aerosol tracer of photochemical reaction products. In SOA particles from toluene, we also detected a compound and its isomer with similar mass spectra to methyltartaric acid standard; the compound and the isomer are tentatively identified as 2,3-dihydroxypentanedioic acid isomers. The ratio of detected C4–C5 dicarboxylic acids to total toluene SOA mass had no significant dependence on the initial VOC/NOx condition. Trace levels of maleic acid and fumaric acid were detected during the photooxidation of naphthalene. Malic acid was produced from the oxidation of α-pinene and isoprene. A trace amount of succinic acid was detected in the SOA produced from the oxidation of isoprene.
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Vamecq, J., E. de Hoffmann i F. Van Hoof. "The microsomal dicarboxylyl-CoA synthetase". Biochemical Journal 230, nr 3 (15.09.1985): 683–93. http://dx.doi.org/10.1042/bj2300683.
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Dicarboxylic acids are products of the omega-oxidation of monocarboxylic acids. We demonstrate that in rat liver dicarboxylic acids (C5-C16) can be converted into their CoA esters by a dicarboxylyl-CoA synthetase. During this activation ATP, which cannot be replaced by GTP, is converted into AMP and PPi, both acting as feedback inhibitors of the reaction. Thermolabile at 37 degrees C, and optimally active at pH 6.5, dicarboxylyl-CoA synthetase displays the highest activity on dodecanedioic acid (2 micromol/min per g of liver). Cell-fractionation studies indicate that this enzyme belongs to the hepatic microsomal fraction. Investigations about the fate of dicarboxylyl-CoA esters disclosed the existence of an oxidase, which could be measured by monitoring the production of H2O2. In our assay conditions this H2O2 production is dependent on and closely follows the CoA consumption. It appears that the chain-length specificity of the handling of dicarboxylic acids by this catabolic pathway (activation to acyl-CoA and oxidation with H2O2 production) parallels the pattern of the degradation of exogenous dicarboxylic acids in vivo.
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Adler, Heidi, i Heli Sirén. "Study on Dicarboxylic Acids in Aerosol Samples with Capillary Electrophoresis". Journal of Analytical Methods in Chemistry 2014 (2014): 1–10. http://dx.doi.org/10.1155/2014/498168.
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The research was performed to study the simultaneous detection of a homologous series ofα,ω-dicarboxylic acids (C2–C10), oxalic, malonic, succinic, glutaric, adipic, pimelic, suberic, azelaic, and sebacic acids, with capillary electrophoresis using indirect UV detection. Good separation efficiency in 2,6-pyridinedicarboxylic acid as background electrolyte modified with myristyl trimethyl ammonium bromide was obtained. The dicarboxylic acids were ionised and separated within five minutes. For the study, authentic samples were collected onto dry cellulose membrane filters of a cascade impactor (12 stages) from outdoor spring aerosols in an urban area. Hot water and ultrasonication extraction methods were used to isolate the acids from membrane filters. Due to the low concentrations of acids in the aerosols, the extracts were concentrated with solid-phase extraction (SPE) before determination. The enrichment of the carboxylic acids was between 86 and 134% with sample pretreatment followed by 100-time increase by preparation of the sample to 50 μL. Inaccuracy was optimised for all the sample processing steps. The aerosols contained dicarboxylic acids C2–C10. Then, mostly they contained C2, C5, and C10. Only one sample contained succinic acid. In the study, the concentrations of the acids in aerosols were lower than 10 ng/m3.
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Hyttinen, Noora, Reyhaneh Heshmatnezhad, Jonas Elm, Theo Kurtén i Nønne L. Prisle. "Technical note: Estimating aqueous solubilities and activity coefficients of mono- and <i>α</i>,<i>ω</i>-dicarboxylic acids using COSMO<i>therm</i>". Atmospheric Chemistry and Physics 20, nr 21 (9.11.2020): 13131–43. http://dx.doi.org/10.5194/acp-20-13131-2020.
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Abstract. We have used the COSMOtherm program to estimate activity coefficients and solubilities of mono- and α,ω-dicarboxylic acids and water in binary acid–water systems. The deviation from ideality was found to be larger in the systems containing larger acids than in the systems containing smaller acids. COnductor-like Screening MOdel for Real Solvents (COSMO-RS) underestimates experimental monocarboxylic acid activity coefficients by less than a factor of 2, but experimental water activity coefficients are underestimated more especially at high acid mole fractions. We found a better agreement between COSMOtherm-estimated and experimental activity coefficients of monocarboxylic acids when the water clustering with a carboxylic acid and itself was taken into account using the dimerization, aggregation, and reaction extension (COSMO-RS-DARE) of COSMOtherm. COSMO-RS-DARE is not fully predictive, but fit parameters found here for water–water and acid–water clustering interactions can be used to estimate thermodynamic properties of monocarboxylic acids in other aqueous solvents, such as salt solutions. For the dicarboxylic acids, COSMO-RS is sufficient for predicting aqueous solubility and activity coefficients, and no fitting to experimental values is needed. This is highly beneficial for applications to atmospheric systems, as these data are typically not available for a wide range of mixing states realized in the atmosphere, due to a lack of either feasibility of the experiments or sample availability. Based on effective equilibrium constants of different clustering reactions in the binary solutions, acid dimer formation is more dominant in systems containing larger dicarboxylic acids (C5–C8), while for monocarboxylic acids (C1–C6) and smaller dicarboxylic acids (C2–C4), hydrate formation is more favorable, especially in dilute solutions.
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Lundgren, B. R., L. R. Villegas-Penaranda, J. R. Harris, A. M. Mottern, D. M. Dunn, C. N. Boddy i C. T. Nomura. "Genetic Analysis of the Assimilation of C5-Dicarboxylic Acids in Pseudomonas aeruginosa PAO1". Journal of Bacteriology 196, nr 14 (2.05.2014): 2543–51. http://dx.doi.org/10.1128/jb.01615-14.
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Song, M., C. Marcolli, U. K. Krieger, A. Zuend i T. Peter. "Liquid-liquid phase separation and morphology of internally mixed dicarboxylic acids/ammonium sulfate/water particles". Atmospheric Chemistry and Physics Discussions 11, nr 10 (28.10.2011): 29141–94. http://dx.doi.org/10.5194/acpd-11-29141-2011.
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Abstract. Knowledge of the physical state and morphology of internally mixed organic/inorganic aerosol particles is still largely uncertain. To obtain more detailed information on liquid-liquid phase separation (LLPS) and morphology of the particles, we investigated complex mixtures of atmospherically relevant dicarboxylic acids containing 5–7 carbon atoms (C5, C6 and C7) having oxygen-to-carbon atomic ratios (O:C) of 0.80, 0.67, and 0.57, respectively, mixed with ammonium sulfate (AS). With micrometer-sized particles of C5/AS/H2O, C6/AS/H2O and C7/AS/H2O as model systems deposited on a hydrophobically coated substrate, laboratory experiments were conducted for various organic-to-inorganic dry mass ratios (OIR) using optical microscopy and Raman spectroscopy. When exposed to cycles of relative humidity (RH), each system showed significantly different phase transitions. While the C5/AS/H2O particles showed no LLPS with OIR = 2:1, 1:1 and 1:4 down to 20% RH, the C6/AS/H2O and C7/AS/H2O particles exhibit LLPS upon drying at RH 50% to 85% and ~90%, respectively, via spinodal decomposition, growth of a second phase from the particle surface or nucleation-and-growth mechanisms depending on the OIR. This suggests that LLPS commonly occurs within the range of O:C<0.7 in tropospheric organic-inorganic aerosols. To support the comparison and interpretation of the experimentally observed phase transitions, thermodynamic equilibrium calculations were performed with the AIOMFAC model. For the C7/AS/H2O and C6/AS/H2O systems, the calculated phase diagrams agree well with the observations while for the C5/AS/H2O system LLPS is predicted by the model at RH below 60% and higher AS concentration, but was not observed in the experiments. Both core-shell structures and partially engulfed structures were observed for the investigated particles, suggesting that such morphologies might also exist in tropospheric aerosols.
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Song, M., C. Marcolli, U. K. Krieger, A. Zuend i T. Peter. "Liquid-liquid phase separation and morphology of internally mixed dicarboxylic acids/ammonium sulfate/water particles". Atmospheric Chemistry and Physics 12, nr 5 (13.03.2012): 2691–712. http://dx.doi.org/10.5194/acp-12-2691-2012.
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Abstract. Knowledge of the physical state and morphology of internally mixed organic/inorganic aerosol particles is still largely uncertain. To obtain more detailed information on liquid-liquid phase separation (LLPS) and morphology of the particles, we investigated complex mixtures of atmospherically relevant dicarboxylic acids containing 5, 6, and 7 carbon atoms (C5, C6 and C7) having oxygen-to-carbon atomic ratios (O:C) of 0.80, 0.67, and 0.57, respectively, mixed with ammonium sulfate (AS). With micrometer-sized particles of C5/AS/H2O, C6/AS/H2O and C7/AS/H2O as model systems deposited on a hydrophobically coated substrate, laboratory experiments were conducted for various organic-to-inorganic dry mass ratios (OIR) using optical microscopy and Raman spectroscopy. When exposed to cycles of relative humidity (RH), each system showed significantly different phase transitions. While the C5/AS/H2O particles showed no LLPS with OIR = 2:1, 1:1 and 1:4 down to 20% RH, the C6/AS/H2O and C7/AS/H2O particles exhibit LLPS upon drying at RH 50 to 85% and ~90%, respectively, via spinodal decomposition, growth of a second phase from the particle surface or nucleation-and-growth mechanisms depending on the OIR. This suggests that LLPS commonly occurs within the range of O:C < 0.7 in tropospheric organic/inorganic aerosols. To support the comparison and interpretation of the experimentally observed phase transitions, thermodynamic equilibrium calculations were performed with the AIOMFAC model. For the C7/AS/H2O and C6/AS/H2O systems, the calculated phase diagrams agree well with the observations while for the C5/AS/H2O system LLPS is predicted by the model at RH below 60% and higher AS concentration, but was not observed in the experiments. Both core-shell structures and partially engulfed structures were observed for the investigated particles, suggesting that such morphologies might also exist in tropospheric aerosols.
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Tao, Ye, i Peter H. McMurry. "Vapor pressures and surface free energies of C14-C18 monocarboxylic acids and C5 and C6 dicarboxylic acids". Environmental Science & Technology 23, nr 12 (grudzień 1989): 1519–23. http://dx.doi.org/10.1021/es00070a011.
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Schäfer, H., K. Taraz i H. Budzikiewicz. "Zur Genese Der Amidisch An Den Chromophor Von Pyoverdinen Gebundenen Dicarbonsäuren [1]". Zeitschrift für Naturforschung C 46, nr 5-6 (1.06.1991): 398–406. http://dx.doi.org/10.1515/znc-1991-5-611.
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Pseudomonas strains of the so-called fluorescent group usually produce several pyoverdins which differ only in the nature of a dicarboxylic acid bound amidically to the chromophor. For the pyoverdins isolated from the culture medium of Pseudomonas fluorescens 12 it is shown that succinic acid is an artefact formed by hydrolysis of succinic amide, and that a-ketoglutaric acid is transformed enzymatically to glutamic acid. This process is reversed after the phase of exponential growth of the bacteria. The ratio C4- vs. C5 -acids changes with the culture time and with increasing Fe3+ content of the medium in favor of the latter
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Zhang, Yan-Lin, Kimitaka Kawamura, Ping Qing Fu, Suresh K. R. Boreddy, Tomomi Watanabe, Shiro Hatakeyama, Akinori Takami i Wei Wang. "Aircraft observations of water-soluble dicarboxylic acids in the aerosols over China". Atmospheric Chemistry and Physics 16, nr 10 (25.05.2016): 6407–19. http://dx.doi.org/10.5194/acp-16-6407-2016.
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Abstract. Vertical profiles of dicarboxylic acids, related organic compounds and secondary organic aerosol (SOA) tracer compounds in particle phase have not yet been simultaneously explored in East Asia, although there is growing evidence that aqueous-phase oxidation of volatile organic compounds may be responsible for the elevated organic aerosols (OA) in the troposphere. Here, we found consistently good correlation of oxalic acid, the most abundant individual organic compounds in aerosols globally, with its precursors as well as biogenic-derived SOA compounds in Chinese tropospheric aerosols by aircraft measurements. Anthropogenically derived dicarboxylic acids (i.e., C5 and C6 diacids) at high altitudes were 4–20 times higher than those from surface measurements and even occasionally dominant over oxalic acid at altitudes higher than 2 km, which is in contrast to the predominance of oxalic acid previously reported globally including the tropospheric and surface aerosols. This indicates an enhancement of tropospheric SOA formation from anthropogenic precursors. Furthermore, oxalic acid-to-sulfate ratio maximized at altitudes of ∼ 2 km, explaining aqueous-phase SOA production that was supported by good correlations with predicted liquid water content, organic carbon and biogenic SOA tracers. These results demonstrate that elevated oxalic acid and related SOA compounds from both the anthropogenic and biogenic sources may substantially contribute to tropospheric OA burden over polluted regions of China, implying aerosol-associated climate effects and intercontinental transport.
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Winterhalter, R., M. Kippenberger, J. Williams, E. Fries, K. Sieg i G. K. Moortgat. "Concentrations of higher dicarboxylic acids C<sub>5</sub>-C<sub>13</sub> in fresh snow samples collected at the High Alpine Research Station Jungfraujoch during CLACE 5 and 6". Atmospheric Chemistry and Physics Discussions 8, nr 5 (30.10.2008): 18689–725. http://dx.doi.org/10.5194/acpd-8-18689-2008.
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Abstract. Samples of freshly fallen snow were collected at the high alpine research station Jungfraujoch (Switzerland) in February and March 2006 and 2007, during the Cloud and Aerosol Characterization Experiments (CLACE) 5 and 6. In this study a new technique has been developed and demonstrated for the measurement of organic acids in fresh snow. The melted snow samples were subjected to solid phase extraction and resulting solution analysed for organic acids by HPLC-MS-TOF using negative electrospray ionization. A series of linear dicarboxylic acids from C5 to C13 and phthalic acid, were identified and quantified. In several samples the biogenic acid pinonic acid was also observed. In fresh snow the median concentration of the most abundant acid, adipic acid, was 0.69 μg L−1 in 2006 and 0.70 μg L−1 in 2007. Glutaric acid was the second most abundant dicarboxylic acid found with median values of 0.46 μg L−1 in 2006 and 0.61 μg L−1 in 2007, while the aromatic acid phthalic acid showed a median concentration of 0.34 μg L−1 in 2006 and 0.45 μg L−1 in 2007. The concentrations in the samples from various snowfall events varied significantly, and were found to be dependent on the back trajectory of the air mass arriving at Jungfraujoch. Air masses of marine origin showed the lowest concentrations of acids whereas the highest concentrations were measured when the air mass was strongly influenced by boundary layer air.
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Winterhalter, R., M. Kippenberger, J. Williams, E. Fries, K. Sieg i G. K. Moortgat. "Concentrations of higher dicarboxylic acids C<sub>5</sub>–C<sub>13</sub> in fresh snow samples collected at the High Alpine Research Station Jungfraujoch during CLACE 5 and 6". Atmospheric Chemistry and Physics 9, nr 6 (23.03.2009): 2097–112. http://dx.doi.org/10.5194/acp-9-2097-2009.
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Abstract. Samples of freshly fallen snow were collected at the high alpine research station Jungfraujoch (Switzerland) in February and March 2006 and 2007, during the Cloud and Aerosol Characterization Experiments (CLACE) 5 and 6. In this study a new technique has been developed and demonstrated for the measurement of organic acids in fresh snow. The melted snow samples were subjected to solid phase extraction and resulting solutions analysed for organic acids by HPLC-MS-TOF using negative electrospray ionization. A series of linear dicarboxylic acids from C5 to C13 and phthalic acid, were identified and quantified. In several samples the biogenic acid pinonic acid was also observed. In fresh snow the median concentration of the most abundant acid, adipic acid, was 0.69 μg L−1 in 2006 and 0.70 μg L−1 in 2007. Glutaric acid was the second most abundant dicarboxylic acid found with median values of 0.46 μg L−1 in 2006 and 0.61 μg L−1 in 2007, while the aromatic acid phthalic acid showed a median concentration of 0.34 μg L−1 in 2006 and 0.45 μg L−1 in 2007. The concentrations in the samples from various snowfall events varied significantly, and were found to be dependent on the back trajectory of the air mass arriving at Jungfraujoch. Air masses of marine origin showed the lowest concentrations of acids whereas the highest concentrations were measured when the air mass was strongly influenced by boundary layer air.
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Yu, Jia-Le, Xiao-Xia Xia, Jian-Jiang Zhong i Zhi-Gang Qian. "Enhanced production of C5 dicarboxylic acids by aerobic-anaerobic shift in fermentation of engineered Escherichia coli". Process Biochemistry 62 (listopad 2017): 53–58. http://dx.doi.org/10.1016/j.procbio.2017.09.001.
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Vasco-Cárdenas, María F., Sonia Baños, Angelina Ramos, Juan F. Martín i Carlos Barreiro. "Proteome response of Corynebacterium glutamicum to high concentration of industrially relevant C4 and C5 dicarboxylic acids". Journal of Proteomics 85 (czerwiec 2013): 65–88. http://dx.doi.org/10.1016/j.jprot.2013.04.019.
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Erb, T. J., I. A. Berg, V. Brecht, M. Muller, G. Fuchs i B. E. Alber. "Synthesis of C5-dicarboxylic acids from C2-units involving crotonyl-CoA carboxylase/reductase: The ethylmalonyl-CoA pathway". Proceedings of the National Academy of Sciences 104, nr 25 (4.06.2007): 10631–36. http://dx.doi.org/10.1073/pnas.0702791104.
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Pavuluri, C. M., K. Kawamura, N. Mihalopoulos i T. Swaminathan. "Laboratory photochemical processing of aqueous aerosols: formation and degradation of dicarboxylic acids, oxocarboxylic acids and α-dicarbonyls". Atmospheric Chemistry and Physics Discussions 15, nr 1 (15.01.2015): 1193–224. http://dx.doi.org/10.5194/acpd-15-1193-2015.
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Abstract. To better understand the photochemical processing of dicarboxylic acids and related polar compounds, we conducted batch UV irradiation experiments on two types of aerosol samples collected from India, which represent anthropogenic (AA) and biogenic aerosols (BA), for time periods of 0.5 to 120 h. The irradiated samples were analyzed for molecular compositions of diacids, oxoacids and α-dicarbonyls. The results show that photochemical degradation of oxalic (C2) and malonic (C3) and other C8-C12 diacids overwhelmed their production in aqueous aerosols whereas succinic acid (C4) and C5-C7 diacids showed a significant increase (ca. 10 times) during the course of irradiation experiments. The photochemical formation of oxoacids and α-dicarbonyls overwhelmed their degradation during the early stages of experiment, except for ω-oxooctanoic acid (ωC8) that showed a similar pattern to that of C4. We also found a gradual decrease in the relative abundance of C2 to total diacids and an increase in the relative abundance of C4 during prolonged experiment. Based on the changes in concentrations and mass ratios of selected species with the irradiation time, we hypothesize that iron-catalyzed photolysis of C2 and C3 diacids dominates their concentrations in Fe-rich atmospheric waters, whereas photochemical formation of C4 diacid (via ωC8) is enhanced with photochemical processing of aqueous aerosols in the atmosphere. This study demonstrates that the ambient aerosols contain abundant precursors that produce diacids, oxoacids and α-dicarbonyls, although some species such as oxalic acid decompose extensively during an early stage of photochemical processing.
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Pavuluri, C. M., K. Kawamura, N. Mihalopoulos i T. Swaminathan. "Laboratory photochemical processing of aqueous aerosols: formation and degradation of dicarboxylic acids, oxocarboxylic acids and α-dicarbonyls". Atmospheric Chemistry and Physics 15, nr 14 (20.07.2015): 7999–8012. http://dx.doi.org/10.5194/acp-15-7999-2015.
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Abstract. To better understand the photochemical processing of dicarboxylic acids and related polar compounds, we conducted batch UV irradiation experiments on two types of aerosol samples collected from India, which represent anthropogenic (AA) and biogenic (BA) aerosols, for time periods of 0.5 to 120 h. The irradiated samples were analyzed for molecular compositions of diacids, oxoacids and α-dicarbonyls. The results show that photochemical degradation of oxalic (C2), malonic (C3) and other C8–C12 diacids overwhelmed their production in aqueous aerosols, whereas succinic acid (C4) and C5–C7 diacids showed a significant increase (ca. 10 times) during the course of irradiation experiments. The photochemical formation of oxoacids and α-dicarbonyls overwhelmed their degradation during the early stages of experiment except for ω-oxooctanoic acid (ωC8), which showed a similar pattern to that of C4. We also found a gradual decrease in the relative abundance of C2 to total diacids and an increase in the relative abundance of C4 during prolonged experiment. Based on the changes in concentrations and mass ratios of selected species with the irradiation time, we hypothesize that iron-catalyzed photolysis of C2 and C3 diacids controls their concentrations in Fe-rich atmospheric waters, whereas photochemical formation of C4 diacid (via ωC8) is enhanced with photochemical processing of aqueous aerosols in the atmosphere. This study demonstrates that the ambient aerosols contain abundant precursors that produce diacids, oxoacids and α-dicarbonyls, although some species such as oxalic acid decompose extensively during an early stage of photochemical processing.
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Ganapathy, V., M. E. Ganapathy, C. Tiruppathi, Y. Miyamoto, V. B. Mahesh i F. H. Leibach. "Sodium-gradient-driven, high-affinity, uphill transport of succinate in human placental brush-border membrane vesicles". Biochemical Journal 249, nr 1 (1.01.1988): 179–84. http://dx.doi.org/10.1042/bj2490179.
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Brush-border membrane vesicles isolated from normal human term placentas were shown to accumulate succinate transiently against a concentration gradient, when an inward-directed Na+ gradient was imposed across the membrane. This uptake was almost totally due to transport into intravesicular space, non-specific binding to the membranes being negligible. The dependence of the initial uptake rate of succinate on Na+ concentration exhibited sigmoidal kinetics, indicating interaction of more than one Na+ ion with the carrier system. The Hill coefficient for this ion was calculated to be 2.7. The Na+-dependent uptake of succinate was electrogenic, resulting in the transfer of positive charge across the membrane. Kinetic analysis showed that succinate uptake in these vesicles occurred via a single transport system, with an apparent affinity constant of 4.8 +/- 0.2 microM and a maximal velocity of 274 +/- 4 pmol/20 s per mg of protein. Uptake of succinate was strongly inhibited by various C4 or C5 dicarboxylic acids, whereas monocarboxylic acids, amino acids and glucose showed little or no effect. Li+ and K+ could not substitute for Na+ in the uptake process. Instead, Li+ was found to have a significant inhibitory effect on the Na+-dependent uptake of succinate.
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Satyavolu, Jagannadh. "Evaluation and Utilization of Dicarboxylic Acids (DCA) as an Alternative to Strong Mineral Acids for Selective Extraction of C5-Sugars in an Integrated Biorefinery". Advances in Industrial Biotechnology 1, nr 1 (19.09.2018): 1–8. http://dx.doi.org/10.24966/aib-5665/100001.
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Yang, Liming, Duc Minh Nguyen, Shiguo Jia, Jeffrey S. Reid i Liya E. Yu. "Impacts of biomass burning smoke on the distributions and concentrations of C2–C5 dicarboxylic acids and dicarboxylates in a tropical urban environment". Atmospheric Environment 78 (październik 2013): 211–18. http://dx.doi.org/10.1016/j.atmosenv.2012.03.049.
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Kostichka, Kristy, Stuart M. Thomas, Katharine J. Gibson, Vasantha Nagarajan i Qiong Cheng. "Cloning and Characterization of a Gene Cluster for Cyclododecanone Oxidation in Rhodococcus ruber SC1". Journal of Bacteriology 183, nr 21 (1.11.2001): 6478–86. http://dx.doi.org/10.1128/jb.183.21.6478-6486.2001.
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ABSTRACT Biological oxidation of cyclic ketones normally results in formation of the corresponding dicarboxylic acids, which are further metabolized in the cell. Rhodococcus ruber strain SC1 was isolated from an industrial wastewater bioreactor that was able to utilize cyclododecanone as the sole carbon source. A reverse genetic approach was used to isolate a 10-kb gene cluster containing all genes required for oxidative conversion of cyclododecanone to 1,12-dodecanedioic acid (DDDA). The genes required for cyclododecanone oxidation were only marginally similar to the analogous genes for cyclohexanone oxidation. The biochemical function of the enzymes encoded on the 10-kb gene cluster, the flavin monooxygenase, the lactone hydrolase, the alcohol dehydrogenase, and the aldehyde dehydrogenase, was determined in Escherichia coli based on the ability to convert cyclododecanone. Recombinant E. colistrains grown in the presence of cyclododecanone accumulated lauryl lactone, 12-hydroxylauric acid, and/or DDDA depending on the genes cloned. The cyclododecanone monooxygenase is a type 1 Baeyer-Villiger flavin monooxygenase (FAD as cofactor) and exhibited substrate specificity towards long-chain cyclic ketones (C11 to C15), which is different from the specificity of cyclohexanone monooxygenase favoring short-chain cyclic compounds (C5 to C7).
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Zarzycki, Jan, Ansgar Schlichting, Nina Strychalsky, Michael Müller, Birgit E. Alber i Georg Fuchs. "Mesaconyl-Coenzyme A Hydratase, a New Enzyme of Two Central Carbon Metabolic Pathways in Bacteria". Journal of Bacteriology 190, nr 4 (7.12.2007): 1366–74. http://dx.doi.org/10.1128/jb.01621-07.
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ABSTRACT The coenzyme A (CoA)-activated C5-dicarboxylic acids mesaconyl-CoA and β-methylmalyl-CoA play roles in two as yet not completely resolved central carbon metabolic pathways in bacteria. First, these compounds are intermediates in the 3-hydroxypropionate cycle for autotrophic CO2 fixation in Chloroflexus aurantiacus, a phototrophic green nonsulfur bacterium. Second, mesaconyl-CoA and β-methylmalyl-CoA are intermediates in the ethylmalonyl-CoA pathway for acetate assimilation in various bacteria, e.g., in Rhodobacter sphaeroides, Methylobacterium extorquens, and Streptomyces species. In both cases, mesaconyl-CoA hydratase was postulated to catalyze the interconversion of mesaconyl-CoA and β-methylmalyl-CoA. The putative genes coding for this enzyme in C. aurantiacus and R. sphaeroides were cloned and heterologously expressed in Escherichia coli, and the proteins were purified and studied. The recombinant homodimeric 80-kDa proteins catalyzed the reversible dehydration of erythro-β-methylmalyl-CoA to mesaconyl-CoA with rates of 1,300 μmol min−1 mg protein−1. Genes coding for similar enzymes with two (R)-enoyl-CoA hydratase domains are present in the genomes of Roseiflexus, Methylobacterium, Hyphomonas, Rhodospirillum, Xanthobacter, Caulobacter, Magnetospirillum, Jannaschia, Sagittula, Parvibaculum, Stappia, Oceanicola, Loktanella, Silicibacter, Roseobacter, Roseovarius, Dinoroseobacter, Sulfitobacter, Paracoccus, and Ralstonia species. A similar yet distinct class of enzymes containing only one hydratase domain was found in various other bacteria, such as Streptomyces species. The role of this widely distributed new enzyme is discussed.
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Chim, Man Mei, Chiu Tung Cheng, James F. Davies, Thomas Berkemeier, Manabu Shiraiwa, Andreas Zuend i Man Nin Chan. "Compositional evolution of particle-phase reaction products and water in the heterogeneous OH oxidation of model aqueous organic aerosols". Atmospheric Chemistry and Physics 17, nr 23 (5.12.2017): 14415–31. http://dx.doi.org/10.5194/acp-17-14415-2017.
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Abstract. Organic compounds present at or near the surface of aqueous droplets can be efficiently oxidized by gas-phase OH radicals, which alter the molecular distribution of the reaction products within the droplet. A change in aerosol composition affects the hygroscopicity and leads to a concomitant response in the equilibrium amount of particle-phase water. The variation in the aerosol water content affects the aerosol size and physicochemical properties, which in turn governs the oxidation kinetics and chemistry. To attain better knowledge of the compositional evolution of aqueous organic droplets during oxidation, this work investigates the heterogeneous OH-radical-initiated oxidation of aqueous methylsuccinic acid (C5H8O4) droplets, a model compound for small branched dicarboxylic acids found in atmospheric aerosols, at a high relative humidity of 85 % through experimental and modeling approaches. Aerosol mass spectra measured by a soft atmospheric pressure ionization source (Direct Analysis in Real Time, DART) coupled with a high-resolution mass spectrometer reveal two major products: a five carbon atom (C5) hydroxyl functionalization product (C5H8O5) and a C4 fragmentation product (C4H6O3). These two products likely originate from the formation and subsequent reactions (intermolecular hydrogen abstraction and carbon–carbon bond scission) of tertiary alkoxy radicals resulting from the OH abstraction occurring at the methyl-substituted carbon site. Based on the identification of the reaction products, a kinetic model of oxidation (a two-product model) coupled with the Aerosol Inorganic–Organic Mixtures Functional groups Activity Coefficients (AIOMFAC) model is built to simulate the size and compositional changes of aqueous methylsuccinic acid droplets during oxidation. Model results show that at the maximum OH exposure, the droplets become slightly more hygroscopic after oxidation, as the mass fraction of water is predicted to increase from 0.362 to 0.424; however, the diameter of the droplets decreases by 6.1 %. This can be attributed to the formation of volatile fragmentation products that partition to the gas phase, leading to a net loss of organic species and associated particle-phase water, and thus a smaller droplet size. Overall, fragmentation and volatilization processes play a larger role than the functionalization process in determining the evolution of aerosol water content and droplet size at high-oxidation stages.
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Alier, M., B. L. van Drooge, M. Dall'Osto, X. Querol, J. O. Grimalt i R. Tauler. "Source apportionment of submicron organic aerosol at an urban background and a road site in Barcelona, Spain". Atmospheric Chemistry and Physics Discussions 13, nr 4 (24.04.2013): 11167–211. http://dx.doi.org/10.5194/acpd-13-11167-2013.
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Abstract. This study investigates the contribution of potential sources to the sub-micron (PM1) organic aerosol (OA) simultaneously detected at an urban background (UB) and a road site (RS) in Barcelona during the 30 days of the intensive field campaign of SAPUSS (Solving Aerosol Problems by Using Synergistic Strategies, September–October 2010). 103 filters at 12 h sampling time resolution were collected at both sites. Thirty-six neutral and polar organic compounds of known emission sources and photo-chemical transformation processes were analyzed by Gas Chromatography-Mass Spectrometry (GC-MS). The concentrations of the trace chemical compounds analyzed are herein presented and discussed. Additionally, OA source apportionment was performed by Multivariate Curve Resolution-Alternating Least Squares (MCR-ALS) and six OA components were identified at both sites: two were of primary anthropogenic OA origin, three of secondary OA origin while a sixth one was not clearly defined. Primary organics from emissions of local anthropogenic activities (Urban primary organic aerosol, Urban POA) contributed for 43% (1.5 μg OC m−3) and 18% (0.4 μg OC m−3) to OA in RS and UB, respectively. A secondary primary source – biomass burning (BBOA) – was found in all the samples (average values 7% RS; 12% UB; 0.3 μg OC m−3), but this component was substantially contributing to OA only when the sampling sites were under influence of regional air mass circulation. Three Secondary Organic Aerosol (SOA) components (describing overall 60% of the variance) were observed in the urban ambient PM1. Products of isoprene oxidation (SOA ISO), i.e. 2-methylglyceric acid, C5 alkene triols and 2-methyltetrols, showed the highest abundance at both sites when the city was under influence of inland air masses. The overall concentrations of SOA ISO were similar at both sites (0.4 and 0.3 μg m−3, 16% and 7%, at UB and RS, respectively). By contrast, a SOA biogenic component attributed to α-pinene oxidation (SOA BIO PIN) presented average concentrations of 0.5 μg m−3 at UB (24% of OA) and 0.2 μg m−3 at RS (7%), respectively, suggesting that this SOA component did not impact the two monitoring site at the same level. A clear anti correlation was observed between SOA ISO and SOA PIN during nucleation days, surprisingly suggesting that some of the growth of urban freshly nucleating particles may be driven by biogenic α-pinene oxidation products but inhibited by isoprene organic compounds. A third SOA component was formed by a mixture of aged anthropogenic and biogenic secondary organic compounds (Aged SOA) that accumulated under stagnant atmospheric conditions, contributing for 12% to OA at RS (0.4 μg OC m−3) and for 18% at UB (0.4 μg OC m−3). A sixth component, formed by C7–C9 dicarboxylic acids and detected especially during daytime, was called "urban oxygenated organic aerosol" (Urban OOA) due to its high abundance in urban RS (23%; 0.8 μg OC m−3) vs. UB (10%; 0.2 μg OC m−3), with a well-defined daytime maximum. This temporal trend and geographical differentiation suggests that local anthropogenic sources were determining this component. However, the changes of these organic molecules were also influenced by the air mass trajectories, indicating that atmospheric conditions had an influence on this component although the specific origin on this component remains unclear. It points to a secondary organic component driven by primary urban sources including cooking and traffic (mainly gasoline) activities.
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Alier, M., B. L. van Drooge, M. Dall'Osto, X. Querol, J. O. Grimalt i R. Tauler. "Source apportionment of submicron organic aerosol at an urban background and a road site in Barcelona (Spain) during SAPUSS". Atmospheric Chemistry and Physics 13, nr 20 (24.10.2013): 10353–71. http://dx.doi.org/10.5194/acp-13-10353-2013.
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Abstract. This study investigates the contribution of potential sources to the submicron (PM1) organic aerosol (OA) simultaneously detected at an urban background (UB) and a road site (RS) in Barcelona during the 30 days of the intensive field campaign of SAPUSS (Solving Aerosol Problems by Using Synergistic Strategies, September–October 2010). A total of 103 filters at 12 h sampling time resolution were collected at both sites. Thirty-six neutral and polar organic compounds of known emission sources and photo-chemical transformation processes were analyzed by gas chromatography–mass spectrometry (GC-MS). The concentrations of the trace chemical compounds analyzed are herein presented and discussed. Additionally, OA source apportionment was performed by multivariate curve resolution–alternating least squares (MCR-ALS) and six OA components were identified at both sites: two were of primary anthropogenic OA origin and three of secondary OA origin, while a sixth one was not clearly defined. Primary organics from emissions of local anthropogenic activities (urban primary organic aerosol, or POA Urban), mainly traffic emissions but also cigarette smoke, contributed 43% (1.5 μg OC m−3) and 18% (0.4 μg OC m−3) to OA at RS and UB, respectively. A secondary primary source – biomass burning (BBOA) – was found in all the samples (average values 7% RS; 12% UB; 0.3 μg OC m−3), but this component was substantially contributing to OA only when the sampling sites were under influence of regional air mass circulation (REG.). Three secondary organic aerosol (SOA) components (describing overall 60% of the variance) were observed in the urban ambient PM1. Products of isoprene oxidation (SOA ISO) – i.e. 2-methylglyceric acid, C5 alkene triols and 2-methyltetrols – showed the highest abundance at both sites when the city was under influence of inland air masses. The overall concentrations of SOA ISO were similar at both sites (0.4 and 0.3 μg m−3, or 16% and 7%, at UB and RS, respectively). By contrast, a SOA biogenic component attributed to α-pinene oxidation (SOA BIO PIN) presented average concentrations of 0.5 μg m−3 at UB (24% of OA) and 0.2 μg m−3 at RS (7%), respectively, suggesting that this SOA component did not impact the two monitoring sites at the same level. A clear anti-correlation was observed between SOA ISO and SOA PIN during nucleation days, surprisingly suggesting that some of the growth of urban freshly nucleating particles may be driven by biogenic α-pinene oxidation products but inhibited by isoprene organic compounds. A third SOA component was formed by a mixture of aged anthropogenic and biogenic secondary organic compounds (SOA Aged) that accumulated under stagnant atmospheric conditions, contributing for 12% to OA at RS (0.4 μg OC m−3) and for 18% at UB (0.4 μg OC m−3). A sixth component, formed by C7–C9 dicarboxylic acids and detected especially during daytime, was called "urban oxygenated organic aerosol" (OOA Urban) due to its high abundance at urban RS (23%; 0.8 μg OCm−3) vs. UB (10%; 0.2 μg OCm−3), with a well-defined daytime maximum. This temporal trend and geographical differentiation suggests that local anthropogenic sources were determining this component. However, the changes of these organic molecules were also influenced by the air mass trajectories, indicating that atmospheric conditions have an influence on this component, although the specific origin on this component remains unclear. It points to a secondary organic component driven by primary urban sources including cooking and traffic (mainly gasoline) activities.
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Deshmukh, Dhananjay K., Kimitaka Kawamura, Manuel Lazaar, Bhagawati Kunwar i Suresh K. R. Boreddy. "Dicarboxylic acids, oxoacids, benzoic acid, <i>α</i>-dicarbonyls, WSOC, OC, and ions in spring aerosols from Okinawa Island in the western North Pacific Rim: size distributions and formation processes". Atmospheric Chemistry and Physics 16, nr 8 (27.04.2016): 5263–82. http://dx.doi.org/10.5194/acp-16-5263-2016.
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Abstract. Size-segregated aerosols (nine stages from < 0.43 to > 11.3 µm in diameter) were collected at Cape Hedo, Okinawa, in spring 2008 and analyzed for water-soluble diacids (C2–C12), ω-oxoacids (ωC2–ωC9), pyruvic acid, benzoic acid, and α-dicarbonyls (C2–C3) as well as water-soluble organic carbon (WSOC), organic carbon (OC), and major ions (Na+, NH4+, K+, Mg2+, Ca2+, Cl−, NO3−, SO42−, and MSA−). In all the size-segregated aerosols, oxalic acid (C2) was found to be the most abundant species, followed by malonic and succinic acids, whereas glyoxylic acid (ωC2) was the dominant oxoacid and glyoxal (Gly) was more abundant than methylglyoxal. Diacids (C2–C5), ωC2, and Gly as well as WSOC and OC peaked at fine mode (0.65–1.1 µm) whereas azelaic (C9) and 9-oxononanoic (ωC9) acids peaked at coarse mode (3.3–4.7 µm). Sulfate and ammonium were enriched in fine mode, whereas sodium and chloride were in coarse mode. Strong correlations of C2–C5 diacids, ωC2 and Gly with sulfate were observed in fine mode (r = 0.86–0.99), indicating a commonality in their secondary formation. Their significant correlations with liquid water content in fine mode (r = 0.82–0.95) further suggest an importance of the aqueous-phase production in Okinawa aerosols. They may also have been directly emitted from biomass burning in fine mode as supported by strong correlations with potassium (r = 0.85–0.96), which is a tracer of biomass burning. Bimodal size distributions of longer-chain diacid (C9) and oxoacid (ωC9) with a major peak in the coarse mode suggest that they were emitted from the sea surface microlayers and/or produced by heterogeneous oxidation of biogenic unsaturated fatty acids on sea salt particles.
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Deshmukh, D. K., K. Kawamura, M. Lazaar, B. Kunwar i S. K. R. Boreddy. "Dicarboxylic acids, oxoacids, benzoic acid, α-dicarbonyls, WSOC, OC, and ions in spring aerosols from Okinawa Island in the western North Pacific Rim: size distributions and formation processes". Atmospheric Chemistry and Physics Discussions 15, nr 18 (30.09.2015): 26509–54. http://dx.doi.org/10.5194/acpd-15-26509-2015.
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Abstract. Size-segregated aerosols (9-stages from < 0.43 to > 11.3 μm in diameter) were collected at Cape Hedo, Okinawa in spring 2008 and analyzed for water-soluble diacids (C2–\\C12), ω-oxoacids (ωC2–ωC9), pyruvic acid, benzoic acid and α-dicarbonyls (C2–C3) as well as water-soluble organic carbon (WSOC), organic carbon (OC) and major ions. In all the size-segregated aerosols, oxalic acid (C2) was found as the most abundant species followed by malonic and succinic acids whereas glyoxylic acid (ωC2) was the dominant oxoacid and glyoxal (Gly) was more abundant than methylglyoxal. Diacids (C2–C5), ωC2 and Gly as well as WSOC and OC peaked at 0.65–1.1 μm in fine mode whereas azelaic (C9) and 9-oxononanoic (ωC9) acids peaked at 3.3–4.7 μm in coarse mode. Sulfate and ammonium are enriched in fine mode whereas sodium and chloride are in coarse mode. These results imply that water-soluble species in the marine aerosols could act as cloud condensation nuclei (CCN) to develop the cloud cover over the western North Pacific Rim. The organic species are likely produced by a combination of gas-phase photooxidation, and aerosol-phase or in-cloud processing during long-range transport. The coarse mode peaks of malonic and succinic acids were obtained in the samples with marine air masses, suggesting that they may be associated with the reaction on sea salt particles. Bimodal size distributions of longer-chain diacid (C9) and oxoacid (ωC9) with a major peak in the coarse mode suggest their production by photooxidation of biogenic unsaturated fatty acids via heterogeneous reactions on sea salt particles.
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Ye, Dae-yeol, Jo Hyun Moon i Gyoo Yeol Jung. "Recent Progress in Metabolic Engineering of Escherichia coli for the Production of Various C4 and C5-Dicarboxylic Acids". Journal of Agricultural and Food Chemistry, 17.07.2023. http://dx.doi.org/10.1021/acs.jafc.3c02156.
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Pourafshar, Shirin, Mira Nicchitta, Crystal C. Tyson, Laura P. Svetkey, David Corcoran, James Bain, Michael Muehlbauer i in. "Abstract MP43: Urine And Plasma Metabolome of Healthy Adults Consuming the Dietary Approaches to Stop Hypertension Diet: A Pilot Study". Circulation 141, Suppl_1 (3.03.2020). http://dx.doi.org/10.1161/circ.141.suppl_1.mp43.
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The mechanisms of the Dietary Approaches to Stop Hypertension (DASH) diet on various health markers remain unclear. The objective of this study was to identify plasma and urine metabolites altered by DASH that may elucidate mechanisms of benefit and suggest biomarkers to facilitate research and monitoring. We tested metabolomics differences in a controlled feeding study of 20 people consuming a Control diet for one wk followed by 2 wks of random assignment to Control or DASH. Fasting plasma and 24-hour urine samples collected at the end of each wk were profiled for metabolites using non-targeted GC/MS and amino acids and acylcarnitines were measured in plasma using a targeted panel. Linear models compared metabolite levels between DASH and Control during the final two randomized feeding wks [nominal p<0.05 and false discovery rate (FDR) adjusted p<0.2]. Compared to Control, DASH is designed to be lower in total fat and saturated fat, but higher in protein, fiber, potassium, magnesium and calcium. Overall, we found 161 identifiable urine metabolites. In FDR adjusted tests, urine excretion of a variety of polyphenolic acids were higher on DASH. In plasma, gamma tocopherol, acylcarnitine C5 from branched chain amino acid (BCAAs) metabolism, and amino acids including BCAAs leucine/isoleucine and valine were lower on DASH (Table 1). Several small and medium chain dicarboxylic acylcarnitines were higher on DASH. Consumption of DASH increases urine levels of a set of polyphenolic compounds many of which have been linked to lower blood pressure in animal and small human studies. In plasma, BCAAs are lower on DASH despite higher protein intake. Further research is needed to investigate these metabolites as a panel for dietary monitoring in hypertension. Table 1. Nontargeted and targeted metabolites (Selected metabolites are shown here) in DASH and Control.
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Artiukhov, Artem V., Alexey V. Kazantsev, Nikolay V. Lukashev, Marco Bellinzoni i Victoria I. Bunik. "Selective Inhibition of 2-Oxoglutarate and 2-Oxoadipate Dehydrogenases by the Phosphonate Analogs of Their 2-Oxo Acid Substrates". Frontiers in Chemistry 8 (12.01.2021). http://dx.doi.org/10.3389/fchem.2020.596187.
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Phosphonate analogs of pyruvate and 2-oxoglutarate are established specific inhibitors of cognate 2-oxo acid dehydrogenases. The present work develops application of this class of compounds to specific in vivo inhibition of 2-oxoglutarate dehydrogenase (OGDH) and its isoenzyme, 2-oxoadipate dehydrogenase (OADH). The isoenzymes-enriched preparations from the rat tissues with different expression of OADH and OGDH are used to characterize their interaction with 2-oxoglutarate (OG), 2-oxoadipate (OA) and the phosphonate analogs. Despite a 100-fold difference in the isoenzymes ratio in the heart and liver, similar Michaelis saturations by OG are inherent in the enzyme preparations from these tissues (KmOG = 0.45 ± 0.06 and 0.27 ± 0.026 mM, respectively), indicating no significant contribution of OADH to the OGDH reaction, or similar affinities of the isoenzymes to OG. However, the preparations differ in the catalysis of OADH reaction. The heart preparation, where OADH/OGDH ratio is ≈ 0.01, possesses low-affinity sites to OA (KmOA = 0.55 ± 0.07 mM). The liver preparation, where OADH/OGDH ratio is ≈ 1.6, demonstrates a biphasic saturation with OA: the low-affinity sites (Km,2OA = 0.45 ± 0.12 mM) are similar to those of the heart preparation; the high-affinity sites (Km,1OA = 0.008 ± 0.001 mM), revealed in the liver preparation only, are attributed to OADH. Phosphonate analogs of C5-C7 dicarboxylic 2-oxo acids inhibit OGDH and OADH competitively to 2-oxo substrates in all sites. The high-affinity sites for OA are affected the least by the C5 analog (succinyl phosphonate) and the most by the C7 one (adipoyl phosphonate). The opposite reactivity is inherent in both the low-affinity OA-binding sites and OG-binding sites. The C6 analog (glutaryl phosphonate) does not exhibit a significant preference to either OADH or OGDH. Structural analysis of the phosphonates binding to OADH and OGDH reveals the substitution of a tyrosine residue in OGDH for a serine residue in OADH among structural determinants of the preferential binding of the bulkier ligands to OADH. The consistent kinetic and structural results expose adipoyl phosphonate as a valuable pharmacological tool for specific in vivo inhibition of the DHTKD1-encoded OADH, a new member of mammalian family of 2-oxo acid dehydrogenases, up-regulated in some cancers and associated with diabetes and obesity.