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Sample records for aldehydes organic acids

  1. Indoor air chemistry: Formation of organic acids and aldehydes

    SciTech Connect

    Zhang, J.; Lioy, P.J. ||; Wilson, W.E.

    1994-12-31

    Laying emphasis on the formation of aldehydes and organic acids, the study has examined the gas-phase reactions of ozone with unsaturated VOCs. The formation of formaldehyde and formic acid was observed for all the three selected unsaturated VOCs: styrene, limonene, and 4-vinylcyclohexene. In addition, benzaldehyde was detected in the styrene-ozone-air reaction system, and acetic acid was also found in limonene-ozone-air system. The study has also examined the gas-phase reactions among formaldehyde, ozone, and nitrogen dioxide and found the formation of formic acid. The nitrate radical was suggested to play an important role in converting formaldehyde into formic acid. Experiments for all the reactions were conducted by using a 4.3 m{sup 3} Teflon chamber. Since the conditions for the reactions were similar to those for indoor environments, the results from the study can be implicated to real indoor situations and can be employed to support the findings and suggestions from the previous studies: certain aldehydes and organic acids could be generated by indoor chemistry.

  2. Chemically Activated Formation of Organic Acids in Reactions of the Criegee Intermediate with Aldehydes and Ketones

    SciTech Connect

    Jalan, Amrit; Allen, Joshua W.; Green, William H.

    2013-08-08

    Reactions of the Criegee intermediate (CI, .CH2OO.) are important in atmospheric ozonolysis models. In this work, we compute the rates for reactions between .CH2OO. and HCHO, CH3CHO and CH3COCH3 leading to the formation of secondary ozonides (SOZ) and organic acids. Relative to infinitely separated reactants, the SOZ in all three cases is found to be 48–51 kcal mol-1 lower in energy, formed via 1,3- cycloaddition of .CH2OO. across the CQO bond. The lowest energy pathway found for SOZ decomposition is intramolecular disproportionation of the singlet biradical intermediate formed from cleavage of the O–O bond to form hydroxyalkyl esters. These hydroxyalkyl esters undergo concerted decomposition providing a low energy pathway from SOZ to acids. Geometries and frequencies of all stationary points were obtained using the B3LYP/MG3S DFT model chemistry, and energies were refined using RCCSD(T)-F12a/cc-pVTZ-F12 single-point calculations. RRKM calculations were used to obtain microcanonical rate coefficients (k(E)) and the reservoir state method was used to obtain temperature and pressure dependent rate coefficients (k(T, P)) and product branching ratios. At atmospheric pressure, the yield of collisionally stabilized SOZ was found to increase in the order HCHO o CH3CHO o CH3COCH3 (the highest yield being 10-4 times lower than the initial .CH2OO. concentration). At low pressures, chemically activated formation of organic acids (formic acid in the case of HCHO and CH3COCH3, formic and acetic acid in the case of CH3CHO) was found to be the major product channel in agreement with recent direct measurements. Collisional energy transfer parameters and the barrier heights for SOZ reactions were found to be the most sensitive parameters determining SOZ and organic acid yield.

  3. Emission of short chained organic acids, aldehydes and monoterpenes from Quercus ilex L. and Pinus pinea L. in relation to physiological activities, carbon budget and emission algorithms

    NASA Astrophysics Data System (ADS)

    Kesselmeier, J.; Bode, K.; Hofmann, U.; Müller, H.; Schäfer, L.; Wolf, A.; Ciccioli, P.; Brancaleoni, E.; Cecinato, A.; Frattoni, M.; Foster, P.; Ferrari, C.; Jacob, V.; Fugit, J. L.; Dutaur, L.; Simon, V.; Torres, L.

    We report on the emission of monoterpenes, short-chained organic acids and aldehydes from Mediterranean oak ( Quercus ilex L.) and pine (Pinus pinea L.). All studies were done with dynamic cuvettes enclosing intact branches at the top of the canopy flushed with ambient air. Daily trends are compared with the photosynthetic active radiation (PAR), leaf temperature and the physiological activities of the enclosed branches, i.e. assimilation and transpiration, with special attention on the carbon budget. Oak emits monoterpenes in high amounts, up to 2% of the assimilated carbon. As compared with monoterpenes, short-chained organic acids and aldehydes are of minor importance for oak. However, on a leaf dry-weight basis equal amounts of acids and aldehydes are released from oak and pine. As pine emitted only low amounts of terpenes (below 0.2% of the assimilated carbon) the release of terpenes and oxygenated compounds is of equal importance for this species. A comparison of a modelled light and temperature driven emission with the observed volatile organic compounds (VOC) emissions showed good agreement for monoterpenes as well as for organic acids emitted in the case of oak. For pine only the release of acids showed an adequate relation to the algorithm data, whereas the terpene emissions seemed to be dominated by temperature effects.

  4. Photoorganocatalytic One-Pot Synthesis of Hydroxamic Acids from Aldehydes.

    PubMed

    Papadopoulos, Giorgos N; Kokotos, Christoforos G

    2016-05-10

    An efficient one-pot synthesis of hydroxamic acids from aldehydes and hydroxylamine is described. A fast, visible-light-mediated metal-free hydroacylation of dialkyl azodicarboxylates was used to develop the subsequent addition of hydroxylamine hydrochloride. A range of aliphatic and aromatic aldehydes were employed in this reaction to give hydroxamic acids in high to excellent yields. Application of the current methodology was demonstrated in the synthesis of the anticancer medicine vorinostat. PMID:27038037

  5. 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.

  6. Aldehydes, carboxylic acids and inorganic nitrate during NSMCS

    NASA Astrophysics Data System (ADS)

    Grosjean, Daniel

    This article describes the methods and results of a study involving measurements of ambient levels of carboxylic acids (formic, acetic and oxalic), aldehydes (formaldehyde, acetaldehyde, propanal, n- butanal, n- pentanal and benzaldehyde) and total inorganic nitrate (nitric acid + particulate nitrate) during the Nitrogen Species Methods Comparison Study (NSMCS). Results for inorganic nitrate obtained using Teflon-nylon filter packs are compared to those obtained with nylon-nylon filter units and to those obtained by other methods during NSMCS. Calculations are presented of the distribution of gas phase nitrogen among NO, NO 2, HONO 2 and PAN, and of the positive bias due to PAN and HONO 2 in NOx measurements by chemiluminescence. Data for aldehydes and carboxylic acids are discussed in terms of sampling efficiency, gas-aerosol phase distribution, possible interferents (e.g. PAN as acetate on alkaline filters), diurnal variations, and relative importance of emissions vs in-situ daytime and night-time formation and removal processes.

  7. Campholenic aldehyde ozonolysis: a mechanism leading to specific biogenic secondary organic aerosol constituents

    NASA Astrophysics Data System (ADS)

    Kahnt, A.; Iinuma, Y.; Mutzel, A.; Böge, O.; Claeys, M.; Herrmann, H.

    2014-01-01

    In the present study, campholenic aldehyde ozonolysis was performed to investigate pathways leading to specific biogenic secondary organic aerosol (SOA) marker compounds. Campholenic aldehyde, a known α-pinene oxidation product, is suggested to be a key intermediate in the formation of terpenylic acid upon α-pinene ozonolysis. It was reacted with ozone in the presence and absence of an OH radical scavenger, leading to SOA formation with a yield of 0.75 and 0.8, respectively. The resulting oxidation products in the gas and particle phases were investigated employing a denuder/filter sampling combination. Gas-phase oxidation products bearing a carbonyl group, which were collected by the denuder, were derivatised by 2,4-dinitrophenylhydrazine (DNPH) followed by liquid chromatography/negative ion electrospray ionisation time-of-flight mass spectrometry analysis and were compared to the gas-phase compounds detected by online proton-transfer-reaction mass spectrometry. Particle-phase products were also analysed, directly or after DNPH derivatisation, to derive information about specific compounds leading to SOA formation. Among the detected compounds, the aldehydic precursor of terpenylic acid was identified and its presence was confirmed in ambient aerosol samples from the DNPH derivatisation, accurate mass data, and additional mass spectrometry (MS2 and MS3 fragmentation studies). Furthermore, the present investigation sheds light on a reaction pathway leading to the formation of terpenylic acid, involving α-pinene, α-pinene oxide, campholenic aldehyde, and terpenylic aldehyde. Additionally, the formation of diaterpenylic acid acetate could be connected to campholenic aldehyde oxidation. The present study also provides insights into the source of other highly functionalised oxidation products (e.g. m / z 201, C9H14O5 and m / z 215, C10H16O5), which have been observed in ambient aerosol samples and smog chamber-generated monoterpene SOA. The m / z 201 and 215

  8. 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.

  9. Kinetic measurements of the reactivity of hydrogen peroxide and ozone towards small atmospherically relevant aldehydes, ketones and organic acids in aqueous solutions

    NASA Astrophysics Data System (ADS)

    Schöne, L.; Herrmann, H.

    2014-05-01

    Free radical reactions are an important degradation process for organic compounds within the aqueous atmospheric environment. Nevertheless, non-radical oxidants such as hydrogen peroxide and ozone also contribute to the degradation and conversion of these substances (Tilgner and Herrmann, 2010). In this work, kinetic investigations of non-radical reactions were conducted using UV / Vis spectroscopy (dual-beam spectrophotometer and stopped flow technique) and a capillary electrophoresis system applying pseudo-first order kinetics to reactions of glyoxal, methylglyoxal, glycolaldehyde, glyoxylic, pyruvic and glycolic acid as well as methacrolein (MACR) and methyl vinyl ketone (MVK) with H2O2 and ozone at 298 K. The measurements indicate rather small rate constants at room temperature of k2nd < 3 M-1 s-1 (except for the unsaturated compounds exposed to ozone). Compared to radical reaction rate constants the values are about 10 orders of magnitude smaller (kOH • ~109 M-1 s-1). However, when considering the much larger non-radical oxidant concentrations compared to radical concentrations in urban cloud droplets, calculated first-order conversion rate constants change the picture towards H2O2 reactions becoming more important, especially when compared to the nitrate radical. For some reactions mechanistic suggestions are also given.

  10. Kinetic measurements on the reactivity of hydrogen peroxide and ozone towards small atmospherically relevant aldehydes, ketones and organic acids in aqueous solution

    NASA Astrophysics Data System (ADS)

    Schöne, L.; Herrmann, H.

    2013-10-01

    Within the aqueous atmospheric environment free radical reactions are an important degradation process for organic compounds. Nevertheless, non-radical oxidants like hydrogen peroxide and ozone also contribute to the degradation and conversion of this substance group (Tilgner und Herrmann, 2010). In this work kinetic investigations of non-radical reactions were conducted using UV/Vis spectroscopy (dual-beam spectrophotometer and Stopped Flow technique) and a capillary electrophoresis system applying pseudo-first order kinetics of glyoxal, methylglyoxal, glycolaldehyde, glyoxylic, pyruvic and glycolic acids as well as methacrolein (MACR) and methyl vinyl ketone (MVK) towards H2O2 and ozone. The measurements indicate rather small rate constants at room temperature of k2nd < 3 M-1 s-1 (except for the unsaturated compounds exposed to ozone). Compared to radical reaction rate constants the values are about 10 orders of magnitude smaller (kOH· ~ 109 M-1 s-1). However, when considering the much larger non-radical oxidant concentrations compared to radical concentrations in urban cloud droplets, calculated turnovers change the picture to more important H2O2 reactions especially when compared to the nitrate radical. For some reactions also mechanistic suggestions are given.

  11. Triggering the approach of an arene or heteroarene towards an aldehyde via Lewis acid-aldehyde communication.

    PubMed

    Pratihar, Sanjay

    2016-03-01

    The present work reports a combined experimental/computational study of the Lewis acid promoted hydroxyalkylation reaction involving aldehyde and arene/heteroarene and reveals a mechanism in which the rate determining aldehyde to alcohol formation via a four-member cyclic transition state (TS) involves a transfer of hydrogen from arene/heteroarene C-H to aldehyde oxygen with the breaking of the C-H bond and formation of C-C and O-H bonds. The effect of different Sn(iv) derivatives on the hydroxyalkylation reaction from different in situ NMR and computational studies reveals that although the exergonic formation of the intermediate and its gained electrophilicity at the carbonyl carbon drive the reaction in SnCl4 compared to other Sn(iv) derivatives, the overall reaction is low yielding because of its stable intermediate. With respect to different aldehydes, LA promoted hydroxylation was found to be more feasible for an electron withdrawing aldehyde compared to electron rich aldehyde because of lower stability, enhanced electrophilicity gained at the aldehyde center, and a lower activation barrier between its intermediate and TS in the former as compared to the latter. The relative stability of the LA-aldehyde adduct decreases in the order SnCl4 > AlCl3 > InCl3 > BF3 > ZnCl2 > TiCl4 > SiCl4, while the activation barrier (ΔG(#)) between intermediate and transition states increases in the order AlCl3 < SnCl4 < InCl3 < BF3 < TiCl4 < ZnCl2 < SiCl4. On the other hand, the activation barriers in the case of different arenes/heteroarenes are in the order of indole < furan < anisole < thiophene < toluene < benzene < chlorobenzene < cyanobenzene, which suggests a facile reaction in the case of indole and the most difficult reaction in the case of cyanobenzene. The ease of formation of the corresponding diaryl methyl carbocation from the alcohol-LA intermediate is responsible for the determination of the undesired product and is found to be more viable in the case of strong

  12. Studies on organic indole-3-aldehyde single crystals

    NASA Astrophysics Data System (ADS)

    Haja Hameed, A. S.; Ravi, G.; Dhanasekaran, R.; Ramasamy, P.

    Indole-3-aldehyde (IA) is a new organic nonlinear material for which its solubility in methanol and acetone was found out using the apparatus fabricated by the authors. In order to get the good-quality crystals, methods of evaporation of solvent at room temperature and slow cooling of saturated solution at boiling temperature were adopted. Simulated lattice parameter values were found out using experimentally known " d" values. The etching and mechanical strength studies on different planes of the crystal were carried out. Decomposition temperature, weight loss and different functional bond frequencies associated with the crystal were also found out from differential thermal analysis (DTA), thermo-gravimetric analysis (TGA) and Fourier transform infra-red (FTIR) spectroscopic analysis, respectively.

  13. Oxidation of fatty aldehydes to fatty acids by Escherichia coli cells expressing the Vibrio harveyi fatty aldehyde dehydrogenase (FALDH).

    PubMed

    Buchhaupt, Markus; Guder, Jan; Sporleder, Fenja; Paetzold, Melanie; Schrader, Jens

    2013-03-01

    Fatty acids represent an important renewable feedstock for the chemical industry. To enable biotechnological one carbon truncations of fatty acids, the enzymes α-dioxygenase and fatty aldehyde dehydrogenase (FALDH) have to be combined in a two-step process. We expressed an FALDH from V. harveyi in E. coli and characterized its substrate spectrum with a focus on the number and position of double bonds in the fatty aldehyde molecules. Synthesis of the expected fatty acid products was proven by analysis of whole cell biotransformation products. Coexpression of a H(2)O-forming NADPH oxidase (NOX) from Lactobacillus sanfranciscensis led to the implementation of a cofactor regeneration cycle in in vitro oxidation experiments. The presence of NOX in whole cell biotransformations improved reaction velocity but did not result in higher product yields. We could further demonstrate that at least part of the endogenous NAD(P)(+) regeneration capacity in the resting cells results from the respiratory chain. The whole cell catalyst with the high broad range FALDH activity described here is an important biotechnological module for lipid biotransformation processes, especially the shortening of fatty acids. PMID:23180547

  14. Heteropolyacid-functionalized aluminum 2-aminoterephthalate metal-organic frameworks as reactive aldehyde sorbents and catalysts.

    PubMed

    Bromberg, Lev; Su, Xiao; Hatton, T Alan

    2013-06-26

    Porous materials based on aluminum(III) 2-aminoterephthalate metal organic frameworks (MOFs NH2MIL101(Al) and NH2MIL53(Al)) and their composites with phosphotungstic acid (PTA) were studied as sorbents of saturated vapors of acetaldehyde, acrolein, and butyraldehyde. MOF functionalization by PTA impregnation from aqueous/methanol solutions resulted in MOF with the original crystal topology with the presence of an ordered PTA phase in the MOF/PTA composite. The MOF/PTA composites contained 29-32 wt % PTA and were stable against loss of PTA through leaching to the aqueous/organic solvent solutions. The MOF and MOF/PTA materials exhibited equilibrium uptake of acetaldehyde from its saturated vapor phase exceeding 50 and 600 wt %, respectively, at 25 °C. The acetaldehyde vapor uptake occurs through the vapor condensation, pore-filling mechanism with simultaneous conversion of acetaldehyde to crotonaldehyde and higher-molecular-weight compounds resulting from repeated aldol condensation. The products of aldehyde condensation and polymerization were identified by MALDI-TOF and electrospray mass spectrometry. The kinetics of the MOF- and MOF/PTA-catalyzed aldol condensation of acetaldehyde were studied in water-acetonitrile mixtures. The aldol condensation kinetics in MOF suspensions were rapid and pseudo-first-order. The apparent second-order rate constants for the aldol condensation catalyzed by MOF/PTA were estimated to be 5 × 10(-4) to 1.5 × 10(-3) M(-1)s(-1), which are higher than those reported in the case of homogeneous catalysis by amino acids or sulfuric acid. MOF and MOF/PTA materials are efficient heterogeneous catalysts for the aldehyde self-condensation in aqueous-organic media. PMID:23673368

  15. Formation of aldehydes and carboxylic acids in ozonated surface water and wastewater: a clear relationship with fluorescence changes.

    PubMed

    Liu, Chen; Tang, Xiangyu; Kim, Jaeshin; Korshin, Gregory V

    2015-04-01

    This study examined the formation of aldehydes and carboxylic acids in ozonated surface water and municipal wastewater secondary effluent and addressed correlations between the generation of these compounds and concurrent changes of the fluorescence of natural/effluent organic matter (NOM/EfOM) substrates. Ozonation was effective in removing fluorophores in all excitation/emission matrix (EEM) regions, with those operationally assigned to humic- and protein-like species showing relatively higher reactivity than fulvic-like species. Examination of HO exposures and attendant changes of fluorescence-based parameters allows establishing strong linear relationships between formation of the aldehydes and carboxylic acids and the relative changes of integrated fluorescence (ΔIF/IF0). This demonstrates the feasibility of surrogate monitoring of the formation of biodegradable ozonation by-products via online measurements of water/wastewater EEM fluorescence. PMID:25576127

  16. Aldehyde-Tagged Zirconium Metal-Organic Frameworks: a Versatile Platform for Postsynthetic Modification.

    PubMed

    Xi, Fu-Gui; Liu, Hui; Yang, Ning-Ning; Gao, En-Qing

    2016-05-16

    Aldehyde-tagged UiO-67-type metal-organic frameworks (MOFs) have been synthesized via the direct solvothermal method or postsynthetic ligand exchange. Various functionalities have been introduced into the MOFs via postsynthetic modification (PSM) employing C-N and C-C coupling reactions of the aldehyde tag. Tandem PSM has also been demonstrated. An amino-functionalized MOF obtained by PSM is shown to be an efficient, heterogeneous, and recyclable catalyst for Knoevenagel condensation. PMID:27136395

  17. Aldehyde Dehydrogenase Gene Superfamily in Populus: Organization and Expression Divergence between Paralogous Gene Pairs

    PubMed Central

    Tian, Feng-Xia; Zang, Jian-Lei; Wang, Tan; Xie, Yu-Li; Zhang, Jin; Hu, Jian-Jun

    2015-01-01

    Aldehyde dehydrogenases (ALDHs) constitute a superfamily of NAD(P)+-dependent enzymes that catalyze the irreversible oxidation of a wide range of reactive aldehydes to their corresponding nontoxic carboxylic acids. ALDHs have been studied in many organisms from bacteria to mammals; however, no systematic analyses incorporating genome organization, gene structure, expression profiles, and cis-acting elements have been conducted in the model tree species Populus trichocarpa thus far. In this study, a comprehensive analysis of the Populus ALDH gene superfamily was performed. A total of 26 Populus ALDH genes were found to be distributed across 12 chromosomes. Genomic organization analysis indicated that purifying selection may have played a pivotal role in the retention and maintenance of PtALDH gene families. The exon-intron organizations of PtALDHs were highly conserved within the same family, suggesting that the members of the same family also may have conserved functionalities. Microarray data and qRT-PCR analysis indicated that most PtALDHs had distinct tissue-specific expression patterns. The specificity of cis-acting elements in the promoter regions of the PtALDHs and the divergence of expression patterns between nine paralogous PtALDH gene pairs suggested that gene duplications may have freed the duplicate genes from the functional constraints. The expression levels of some ALDHs were up- or down-regulated by various abiotic stresses, implying that the products of these genes may be involved in the adaptation of Populus to abiotic stresses. Overall, the data obtained from our investigation contribute to a better understanding of the complexity of the Populus ALDH gene superfamily and provide insights into the function and evolution of ALDH gene families in vascular plants. PMID:25909656

  18. Immobilization of DNA via oligonucleotides containing an aldehyde or carboxylic acid group at the 5' terminus.

    PubMed Central

    Kremsky, J N; Wooters, J L; Dougherty, J P; Meyers, R E; Collins, M; Brown, E L

    1987-01-01

    A general method for the immobilization of DNA through its 5'-end has been developed. A synthetic oligonucleotide, modified at its 5'-end with an aldehyde or carboxylic acid, was attached to latex microspheres containing hydrazide residues. Using T4 polynucleotide ligase and an oligonucleotide splint, a single stranded 98mer was efficiently joined to the immobilized synthetic fragment. After impregnation of the latex microspheres with the fluorescent dye, Nile Red and attachment of an aldehyde 16mer, 5 X 10(5) bead-DNA conjugates could be detected with a conventional fluorimeter. Images PMID:3562241

  19. Dual Lewis Acid/Lewis Base Catalyzed Acylcyanation of Aldehydes: A Mechanistic Study.

    PubMed

    Laurell Nash, Anna; Hertzberg, Robin; Wen, Ye-Qian; Dahlgren, Björn; Brinck, Tore; Moberg, Christina

    2016-03-01

    A mechanistic investigation, which included a Hammett correlation analysis, evaluation of the effect of variation of catalyst composition, and low-temperature NMR spectroscopy studies, of the Lewis acid-Lewis base catalyzed addition of acetyl cyanide to prochiral aldehydes provides support for a reaction route that involves Lewis base activation of the acyl cyanide with formation of a potent acylating agent and cyanide ion. The cyanide ion adds to the carbonyl group of the Lewis acid activated aldehyde. O-Acylation by the acylated Lewis base to form the final cyanohydrin ester occurs prior to decomplexation from titanium. For less reactive aldehydes, the addition of cyanide is the rate-determining step, whereas, for more reactive, electron-deficient aldehydes, cyanide addition is rapid and reversible and is followed by rate-limiting acylation. The resting state of the catalyst lies outside the catalytic cycle and is believed to be a monomeric titanium complex with two alcoholate ligands, which only slowly converts into the product. PMID:26592522

  20. A quick responding quartz crystal microbalance sensor array based on molecular imprinted polyacrylic acids coating for selective identification of aldehydes in body odor.

    PubMed

    Jha, Sunil K; Hayashi, Kenshi

    2015-03-01

    In present work, a novel quartz crystal microbalance (QCM) sensor array has been developed for prompt identification of primary aldehydes in human body odor. Molecularly imprinted polymers (MIP) are prepared using the polyacrylic acid (PAA) polymer matrix and three organic acids (propenoic acid, hexanoic acid and octanoic acid) as template molecules, and utilized as QCM surface coating layer. The performance of MIP films is characterized by 4-element QCM sensor array (three coated with MIP layers and one with pure PAA for reference) dynamic and static responses to target aldehydes: hexanal, heptanal, and nonanal in single, binary, and tertiary mixtures at distinct concentrations. The target aldehydes were selected subsequent to characterization of body odor samples with solid phase-micro extraction gas chromatography mass spectrometer (SPME-GC-MS). The hexanoic acid and octanoic acid imprinted PAA exhibit fast response, and better sensitivity, selectivity and reproducibility than the propenoic acid, and non-imprinted PAA in array. The response time and recovery time for hexanoic acid imprinted PAA are obtained as 5 s and 12 s respectively to typical concentrations of binary and tertiary mixtures of aldehydes using the static response. Dynamic sensor array response matrix has been processed with principal component analysis (PCA) for visual, and support vector machine (SVM) classifier for quantitative identification of target odors. Aldehyde odors were identified successfully in principal component (PC) space. SVM classifier results maximum recognition rate 79% for three classes of binary odors and 83% including single, binary, and tertiary odor classes in 3-fold cross validation. PMID:25618646

  1. Reductions of aldehydes and ketones with a readily available N-heterocyclic carbene borane and acetic acid

    PubMed Central

    Lamm, Vladimir; Pan, Xiangcheng

    2013-01-01

    Summary Acetic acid promotes the reduction of aldehydes and ketones by the readily available N-heterocyclic carbene borane, 1,3-dimethylimidazol-2-ylidene borane. Aldehydes are reduced over 1–24 h at room temperature with 1 equiv of acetic acid and 0.5 equiv of the NHC-borane. Ketone reductions are slower but can be accelerated by using 5 equiv of acetic acid. Aldehydes can be selectively reduced in the presence of ketones. On a small scale, products are isolated by evaporation of the reaction mixture and direct chromatography. PMID:23616812

  2. Dissolved organic carbon (DOC) and select aldehydes in cloud and fog water: the role of the aqueous phase in impacting trace gas budgets

    NASA Astrophysics Data System (ADS)

    Ervens, B.; Wang, Y.; Eagar, J.; Leaitch, W. R.; Macdonald, A. M.; Valsaraj, K. T.; Herckes, P.

    2012-12-01

    Cloud and fog droplets efficiently scavenge and process water-soluble compounds and thus modify the chemical composition of the gas and particle phases. The concentrations of dissolved organic carbon (DOC) in the aqueous phase reach concentrations on the order of ~10 mg C L-1 which is typically on the same order of magnitude as the sum of inorganic anions. Aldehydes and carboxylic acids typically comprise a large fraction of DOC because of their high solubility. The dissolution of species in the aqueous phase can lead to (i) the removal of species from the gas phase preventing their processing by gas phase reactions (e.g. photolysis of aldehydes) and (ii) the formation of unique products that do not have any efficient gas phase sources (e.g. dicarboxylic acids). We present measurements of DOC and select aldehydes in fog water at high elevation and intercepted clouds in a biogenically-impacted location (Whistler, Canada) and in fog water in a more polluted area (Davis, CA). Concentrations of formaldehyde, glyoxal and methylglyoxal were in the micromolar range and comprised ≤2% each individually of the DOC. Comparison of the DOC and aldehyde concentrations to those at other locations shows good agreement and reveals highest levels for both in anthropogenically impacted regions. Based on this overview, we conclude that the fraction of organic carbon (dissolved and insoluble inclusions) in the aqueous phase comprises 1-~40% of total organic carbon. Higher values are observed to be associated with aged air masses where organics are expected to be more highly oxidized and thus more soluble. Accordingly, the aqueous/gas partitioning ratio expressed here as an effective Henry's law constant for DOC (KH*DOC) increases by an order of magnitude from 7×103 M atm-1 to 7×104 M atm-1 during the ageing of air masses. The measurements are accompanied by photochemical box model simulations. They suggest that the scavenging of aldehydes by the aqueous phase can reduce HO2 gas

  3. Tropospheric chemistry of natural hydrocarbons, aldehydes, and peroxy radicals: Their connections to sulfuric acid production and climate effects

    SciTech Connect

    Gaffney, J.S.; Marley, N.A.

    1993-05-01

    Recent work has shown that natural hydrocarbon emissions can significantly affect the levels of urban and regional tropospheric ozone. We report on the reactivities of these biogenic trace gases, particularly isoprene, focusing on their importance in the production of aldehydes and peroxy radicals, leading to increased levels of hydrogen over regional forests. Hydrogen peroxide can lead to the wet oxidation of sulfur dioxide to acidic sulfate in aerosols, fogs, and clouds. In turn, acidic sulfate can act to as a light scattering aerosol and a source of cloud condensation nuclei (CCN), potentially leading to global cooling. Aerosol sulfate and other dissolved organic and inorganic compounds can also play important roles as a greenhouse species in the lower troposphere.

  4. Water chemical ionization mass spectrometry of aldehydes, ketones esters, and carboxylic acids

    SciTech Connect

    Hawthorne, S.B.; Miller, D.J.

    1986-11-01

    Chemical ionization mass spectrometry (CI) of aliphatic and aromatic carbonyl compounds using water as the reagent gas provides intense pseudomolecular ions and class-specific fragmentation patterns that can be used to identify aliphatic aldehydes, ketones, carboxylic acids, and esters. The length of ester acyl and alkyl groups can easily be determined on the basis of loss of alcohols from the protonated parent. Water CI provides for an approximately 200:1 selectivity of carbonyl species over alkanes. No reagent ions are detected above 55 amu, allowing species as small as acetone, propanal, acetic acid, and methyl formate to be identified. When deuterate water was used as the reagent, only the carboxylic acids and ..beta..-diketones showed significant H/D exchange. The use of water CI to identify carbonyl compounds in a wastewater from the supercritical water extraction of lignite coal, in lemon oil, and in whiskey volatiles is discussed.

  5. Dissolved organic carbon (DOC) and select aldehydes in cloud and fog water: the role of the aqueous phase in impacting trace gas budgets

    NASA Astrophysics Data System (ADS)

    Ervens, B.; Wang, Y.; Eagar, J.; Leaitch, W. R.; Macdonald, A. M.; Valsaraj, K. T.; Herckes, P.

    2013-05-01

    Cloud and fog droplets efficiently scavenge and process water-soluble compounds and, thus, modify the chemical composition of the gas and particle phases. The concentrations of dissolved organic carbon (DOC) in the aqueous phase reach concentrations on the order of ~ 10 mgC L-1 which is typically on the same order of magnitude as the sum of inorganic anions. Aldehydes and carboxylic acids typically comprise a large fraction of DOC because of their high solubility. The dissolution of species in the aqueous phase can lead to (i) the removal of species from the gas phase preventing their processing by gas phase reactions (e.g., photolysis of aldehydes) and (ii) the formation of unique products that do not have any efficient gas phase sources (e.g., dicarboxylic acids). We present measurements of DOC and select aldehydes in fog water at high elevation and intercepted clouds at a biogenically-impacted location (Whistler, Canada) and in fog water in a more polluted area (Davis, CA). Concentrations of formaldehyde, glyoxal and methylglyoxal were in the micromolar range and comprised ≤ 2% each individually of the DOC. Comparison of the DOC and aldehyde concentrations to those at other locations shows good agreement and reveals highest levels for both in anthropogenically impacted regions. Based on this overview, we conclude that the fraction of organic carbon (dissolved and insoluble inclusions) in the aqueous phase of clouds or fogs, respectively, comprises 2-~ 40% of total organic carbon. Higher values are observed to be associated with aged air masses where organics are expected to be more highly oxidised and, thus, more soluble. Accordingly, the aqueous/gas partitioning ratio expressed here as an effective Henry's law constant for DOC (KH*DOC) increases by an order of magnitude from 7 × 103 M atm-1 to 7 × 104 M atm-1 during the ageing of air masses. The measurements are accompanied by photochemical box model simulations. These simulations are used to contrast two

  6. NAD(+)-independent aldehyde oxidase catalyzes cofactor balanced 3-hydroxypropionic acid production in Klebsiella pneumoniae.

    PubMed

    Li, Ying; Liu, Luo; Tian, Pingfang

    2014-11-01

    The limiting step for biosynthesis of 3-hydroxypropionic acid (3-HP) in Klebsiella pneumoniae is the conversion of 3-hydroxypropionaldehyde (3-HPA) to 3-HP. This reaction is catalyzed by aldehyde dehydrogenase (ALDH) with NAD(+) as a cofactor. Although NAD(+)-dependent ALDH overexpression facilitates 3-HP biosynthesis, ALDH activity decreases and 3-HP stops accumulation when NAD(+) is exhausted. Here, we show that an NAD(+)-independent aldehyde oxidase (AOX) from Pseudomonas sp. AIU 362 holds promise for cofactor-balanced 3-HP production in K. pneumoniae. The AOX coding gene, alod, was heterologously expressed in E. coli and K. pneumoniae, and their respective crude cell extracts showed 38.1 U/mg and 16.6 U/mg activities toward propionaldehyde. The recombinant K. pneumoniae expressing alod showed 13.7 U/mg activity toward 3-HPA; K m and V max were 6.7 mM and 42 μM/min/mg, respectively. In shake-flask cultures, the recombinant K. pneumoniae strain produced 0.89 g 3-HP/l, twice that of the control. Moreover, it produced 3 g 3-HP/l during 24 h fed-batch cultivation in a 5 l bioreactor. The results indicate that AOX can efficiently convert 3-HPA into 3-HP. PMID:24980850

  7. Aqueous phase hydration and hydrate acidity of perfluoroalkyl and n:2 fluorotelomer aldehydes.

    PubMed

    Rayne, Sierra; Forest, Kaya

    2016-01-01

    The SPARC software program and comparative density functional theory (DFT) calculations were used to investigate the aqueous phase hydration equilibrium constants (Khyd) of perfluoroalkyl aldehydes (PFAlds) and n:2 fluorotelomer aldehydes (FTAlds). Both classes are degradation products of known industrial compounds and environmental contaminants such as fluorotelomer alcohols, iodides, acrylates, phosphate esters, and other derivatives, as well as hydrofluorocarbons and hydrochlorofluorocarbons. Prior studies have generally failed to consider the hydration, and subsequent potential hydrate acidity, of these compounds, resulting in incomplete and erroneous predictions as to their environmental behavior. In the current work, DFT calculations suggest that all PFAlds will be dominantly present as the hydrated form in aqueous solution. Both SPARC and DFT calculations suggest that FTAlds will not likely be substantially hydrated in aquatic systems or in vivo. PFAld hydrates are expected to have pKa values in the range of phenols (ca. 9 to 10), whereas n:2 FTAld hydrates are expected to have pKa values ca. 2 to 3 units higher (ca. 12 to 13). In order to avoid spurious modeling predictions and a fundamental misunderstanding of their fate, the molecular and/or dissociated hydrate forms of PFAlds and FTAlds need to be explicitly considered in environmental, toxicological, and waste treatment investigations. The results of the current study will facilitate a more complete examination of the environmental fate of PFAlds and FTAlds. PMID:26980678

  8. An aldehyde group-based P-acid probe for selective fluorescence turn-on sensing of cysteine and homocysteine.

    PubMed

    Yang, Chunlei; Wang, Xiu; Shen, Lei; Deng, Wenping; Liu, Haiyun; Ge, Shenguang; Yan, Mei; Song, Xianrang

    2016-06-15

    A highly sensitive and selective turn on fluorescent probe P-acid-aldehyde (P-CHO) is developed for the determination of cysteine (Cys) and homocysteine (Hcy). The probe is designed and synthesized by incorporating the specific functional group aldehyde group for thiols into a stable π-conjugated material 4,4'-(2,5-dimethoxy-1,4-phenylene) bis(ethyne-2,1-diyl) dibenzoic acid (P-acid). The probe fluorescence is quenched through donor photoinduced electron transfer (d-PET) between the fluorophore (P-acid) and the recognition group (aldehyde group). In the presence of thiols, Cys and Hcy can selectively react with aldehyde group of the probe because the inhibition of d-PET between fluorophore and recognition group. Therefore, a turn-on fluorescent sensor was established for the fluorescence recovery. Under the optimized conditions, the fluorescence response of probe is directly proportional to the concentration of Cys in the range of 4-95 NM L(-1), with a detection limit 3.0 nM. In addition, the sensing system exhibits good selectively toward Cys and Hcy in the presence of other amino acids. It has been successfully applied for bioimaging of Cys and Hcy in living cells with low cell toxicity. PMID:26802748

  9. Lewis Acidity of Bis(perfluorocatecholato)silane: Aldehyde Hydrosilylation Catalyzed by a Neutral Silicon Compound

    DOE PAGESBeta

    Liberman-Martin, Allegra L.; Bergman, Robert G.; Tilley, T. Don

    2015-04-16

    Bis(perfluorocatecholato)silane Si(cat(F)2 was prepared, and stoichiometric binding to Lewis bases was demonstrated with fluoride, triethylphosphine oxide, and N,N'-diisopropylbenzamide. The potent Lewis acidity of Si(cat(F)2 was suggested from catalytic hydrosilylation and silylcyanation reactions with aldehydes. Mechanistic studies of hydrosilylation using an optically active silane substrate, R-(+)-methyl-(1-naphthyl)phenylsilane, proceeded with predominant stereochemical retention at silicon, consistent with a carbonyl activation pathway. The enantiospecificity was dependent on solvent and salt effects, with increasing solvent polarity or addition of NBu4BAr(F)4 leading to a diminished enantiomeric ratio. The medium effects are consistent with an ionic mechanism, wherein hydride transfer occurs prior to silicon-oxygen bond formation.

  10. Lewis Acidity of Bis(perfluorocatecholato)silane: Aldehyde Hydrosilylation Catalyzed by a Neutral Silicon Compound

    SciTech Connect

    Liberman-Martin, Allegra L.; Bergman, Robert G.; Tilley, T. Don

    2015-04-16

    Bis(perfluorocatecholato)silane Si(cat(F)2 was prepared, and stoichiometric binding to Lewis bases was demonstrated with fluoride, triethylphosphine oxide, and N,N'-diisopropylbenzamide. The potent Lewis acidity of Si(cat(F)2 was suggested from catalytic hydrosilylation and silylcyanation reactions with aldehydes. Mechanistic studies of hydrosilylation using an optically active silane substrate, R-(+)-methyl-(1-naphthyl)phenylsilane, proceeded with predominant stereochemical retention at silicon, consistent with a carbonyl activation pathway. The enantiospecificity was dependent on solvent and salt effects, with increasing solvent polarity or addition of NBu4BAr(F)4 leading to a diminished enantiomeric ratio. The medium effects are consistent with an ionic mechanism, wherein hydride transfer occurs prior to silicon-oxygen bond formation.

  11. Genomic organization and expression of the human fatty aldehyde dehydrogenase gene (FALDH)

    SciTech Connect

    Rogers, G.R.; Markova, N.G.; Compton, J.G.

    1997-01-15

    Mutations in the fatty aldehyde dehydrogenase (FALDH) gene cause Sjoegren-Larsson syndrome (SLS) - a disease characterized by mental retardation, spasticity, and congenital ichthyosis. To facilitate mutation analysis in SLS and to study the pathogenesis of FALDH deficiency, we have determined the structural organization and characterized expression of the FALDH (proposed designation ALDH10) gene. The gene consists of 10 exons spanning about 30.5 kb. A TATA-less promoter is associated with the major transcription initiation site found to be 258 hp upstream of the ATG codon. The G4C-rich sequences surrounding the transcription initiation site encompassed regulatory elements that interacted with proteins in HeLa nuclear extracts and were able to promote transcription in vitro. FALDH is widely expressed as three transcripts of 2, 3.8, and 4.0 kb, which originate from multiple polyadenylation signals in the 3{prime} UTR. An alternatively spliced mRNA was detected that contains an extra exon and encodes an enzyme that is likely to have altered membrane-binding properties. The FALDH gene lies only 50-85 kb from ALDH3, an aldehyde dehydrogenase gene that has homologous sequence and intron/exon structure. 25 refs., 4 figs., 1 tab.

  12. Formation of Aldehydic Phosphatidylcholines during the Anaerobic Decomposition of a Phosphatidylcholine Bearing the 9-Hydroperoxide of Linoleic Acid

    PubMed Central

    2016-01-01

    Lipid oxidation-derived carbonyl compounds are associated with the development of various physiological disorders. Formation of most of these products has recently been suggested to require further reactions of oxygen with lipid hydroperoxides. However, in rat and human tissues, the formation of 4-hydroxy-2-nonenal is greatly elevated during hypoxic/ischemic conditions. Furthermore, a previous study found an unexpected result that the decomposition of a phosphatidylcholine (PC) bearing the 13-hydroperoxide of linoleic acid under a nitrogen atmosphere afforded 9-oxononanoyl-PC rather than 13-oxo-9,11-tridecadienoyl-PC as the main aldehydic PC. In the present study, products of the anaerobic decomposition of a PC bearing the 9-hydroperoxide of linoleic acid were analysed by electrospray ionization mass spectrometry. 9-Oxononanoyl-PC (ONA-PC) and several well-known bioactive aldehydes including 12-oxo-9-hydroperoxy-(or oxo or hydroxy)-10-dodecenoyl-PCs were detected. Hydrolysis of the oxidized PC products, methylation of the acids obtained thereby, and subsequent gas chromatography-mass spectroscopy with electron impact ionization further confirmed structures of some of the key aldehydic PCs. Novel, hydroxyl radical-dependent mechanisms of formation of ONA-PC and peroxyl-radical dependent mechanisms of formation of the rest of the aldehydes are proposed. The latter mechanisms will mainly be relevant to tissue injury under hypoxic/anoxic conditions, while the former are relevant under both normoxia and hypoxia/anoxia. PMID:27366754

  13. Identification of Crucial Amino Acids in Mouse Aldehyde Oxidase 3 That Determine Substrate Specificity

    PubMed Central

    Mahro, Martin; Brás, Natércia F.; Cerqueira, Nuno M. F. S. A.; Teutloff, Christian; Coelho, Catarina; Romão, Maria João; Leimkühler, Silke

    2013-01-01

    In order to elucidate factors that determine substrate specificity and activity of mammalian molybdo-flavoproteins we performed site directed mutagenesis of mouse aldehyde oxidase 3 (mAOX3). The sequence alignment of different aldehyde oxidase (AOX) isoforms identified variations in the active site of mAOX3 in comparison to other AOX proteins and xanthine oxidoreductases (XOR). Based on the structural alignment of mAOX3 and bovine XOR, differences in amino acid residues involved in substrate binding in XORs in comparison to AOXs were identified. We exchanged several residues in the active site to the ones found in other AOX homologues in mouse or to residues present in bovine XOR in order to examine their influence on substrate selectivity and catalytic activity. Additionally we analyzed the influence of the [2Fe-2S] domains of mAOX3 on its kinetic properties and cofactor saturation. We applied UV-VIS and EPR monitored redox-titrations to determine the redox potentials of wild type mAOX3 and mAOX3 variants containing the iron-sulfur centers of mAOX1. In addition, a combination of molecular docking and molecular dynamic simulations (MD) was used to investigate factors that modulate the substrate specificity and activity of wild type and AOX variants. The successful conversion of an AOX enzyme to an XOR enzyme was achieved exchanging eight residues in the active site of mAOX3. It was observed that the absence of the K889H exchange substantially decreased the activity of the enzyme towards all substrates analyzed, revealing that this residue has an important role in catalysis. PMID:24358164

  14. IN VITRO ORGANIC NITRATE BIOACTIVATION TO NITRIC OXIDE BY RECOMBINANT ALDEHYDE DEHYDROGENASE 3A1

    PubMed Central

    Lin, Shunxin; Page, Nathaniel A.; Fung, Sun Mi; Fung, Ho-Leung

    2013-01-01

    Organic nitrates (ORNs) are commonly used anti-ischemic and anti-anginal agents, which serve as an exogenous source of the potent vasodilator nitric oxide (NO). Recently, both mitochondrial aldehyde dehydrogenase-2 (ALDH2) and cytosolic aldehyde dehydrogenase-1a1 (ALDH1A1) have been shown to exhibit the ability to selectively bioactivate various ORNs in vitro. The objective of the present research was to examine the potential role of ALDH3A1, another major cytosolic isoform of ALDH, in the in vitro bioactivation of various ORNs, and to estimate the enzyme kinetic parameters toward ORNs through mechanistic modeling. The extent of bioactivation was assayed by exposing recombinant ALDH3A1 to various concentrations of ORNs, and measuring the concentration-time profiles of released NO via a NO-specific electrode. Metabolite formation kinetics was monitored for nitroglycerin (NTG) using LC/MS/MS. Our results showed that ALDH3A1 mRNA and protein were highly expressed in C57BL/6 mouse aortic, cardiac, and hepatic tissues, and it was able to release NO from several ORNs, including NTG, isosorbide dinitrate (ISDN), isosorbide-2-mononitrate (IS-2-MN), and nicorandil with similar Vmax (0.175 – 0.503 nmol/min/mg of ALDH3A1), and Km values of 4.01, 46.5, 818 and 5.75 × 103 μM respectively. However, activation of isosorbide-5-mononitrate (IS-5-MN) by ALDH3A1 was undetectable in vitro. ALDH3A1 was also shown to denitrate NTG, producing primarily glyceryl 1, 2-dinitrate (1, 2-GDN) in preference to glyceryl 1, 3-dinitrate (1, 3-GDN). Therefore, ALDH3A1 may contribute to the bioactivation of ORNs in vivo. PMID:24126018

  15. Thermodynamics of the formation of atmospheric organic particulate matter by accretion reactions—Part 1: aldehydes and ketones

    NASA Astrophysics Data System (ADS)

    Barsanti, Kelley C.; Pankow, James F.

    The term "accretion reactions" is introduced here to refer to the large collection of reactions by which atmospheric organic molecules can add mass, especially as by combination with other organic molecules. A general thermodynamic approach is developed for evaluating the tendency of atmospheric constituents (e.g., C 10 aldehydes) to undergo accretion reactions (e.g., dimerization) and thereby form less volatile molecules (e.g., aldol condensation products) that may subsequently condense and so contribute to the levels of organic particulate matter (OPM) observed in the atmosphere. As an example, gaseous compounds A and B may contribute to OPM formation by the net overall reaction A g+B g=C liq. This reaction may occur according to any of three kinetic schemes. Scheme I: (1) A g+B g=C g (accretion in the gas phase): then (2) C g=C liq (condensation of the accretion product); Scheme II: (1) B g=B liq (condensation of B); then (2) A g+B liq=C liq (heterogeneous accretion reaction of gaseous A with condensed B); or Scheme III: (1) A g+B g=A liq+B liq (condensation of A and B); then (2) A liq+B liq=C liq (accretion of A with B within the PM phase). For all three schemes, the net overall reaction remains A g+B g=C liq. The overall thermodynamic tendency of the net reaction remains the same regardless of the actual predominating kinetic mechanism. If an accretion reaction between two atmospheric components is to produce significant new OPM, appreciable amounts of the product C must form, and the vapor pressure of C must be relatively low so that a significant proportion of C can condense into the multicomponent liquid OPM phase. This study considers the thermodynamics of accretion reactions of atmospheric aldehydes including: (a) hydration, polymerization (i.e., oligomer formation), hemiacetal/acetal formation; and (b) aldol condensation. It was concluded regarding OPM formation that: (1) the reactions in the first group are not thermodynamically favored, either in the

  16. Dual Catalysis Using Boronic Acid and Chiral Amine: Acyclic Quaternary Carbons via Enantioselective Alkylation of Branched Aldehydes with Allylic Alcohols.

    PubMed

    Mo, Xiaobin; Hall, Dennis G

    2016-08-31

    A ferrocenium boronic acid salt activates allylic alcohols to generate transient carbocations that react with in situ-generated chiral enamines from branched aldehydes. The optimized conditions afford the desired acyclic products embedding a methyl-aryl quaternary carbon center with up to 90% yield and 97:3 enantiomeric ratio, with only water as the byproduct. This noble-metal-free method complements alternative methods that are incompatible with carbon-halogen bonds and other sensitive functional groups. PMID:27518200

  17. Visible-Light-Mediated Synthesis of Amides from Aldehydes and Amines via in Situ Acid Chloride Formation.

    PubMed

    Iqbal, Naeem; Cho, Eun Jin

    2016-03-01

    An efficient visible-light photocatalysis-based one-pot amide synthesis method was developed; visible-light irradiation of a mixture of an aldehyde, tert-butyl hydrogen peroxide, and N-chlorosuccinimide using a Ru(bpy)3Cl2 photocatalyst afforded an acid chloride, which subsequently reacted with amine to yield the corresponding amide. The reaction was used to synthesize moclobemide and a D3 receptor intermediate. PMID:26836367

  18. Lanthanide triflates as water-tolerant Lewis acids. Activation of commercial formaldehyde solution and use in the aldol reaction of silyl enol ethers with aldehydes in aqueous media

    SciTech Connect

    Kobayashi, Shue; Hachiya, Iwao

    1994-07-01

    The catalytic effects of lanthanide triflates in the hydroxymethylation and the aldol reaction of silyl enol ethers (w/aldehydes). The rare earth triflates served as Lewis acid catalysts in the aqueous reaction medium.

  19. Identifying Sources of Volatile Organic Compounds and Aldehydes in a High Performance Building

    SciTech Connect

    Ortiz, Anna C.; Russell, Marion; Lee, Wen-Yee; Apte, Michael; Maddalena, Randy

    2010-09-20

    The developers of the Paharpur Business Center (PBC) and Software Technology Incubator Park in New Delhi, India offer an environmentally sustainable building with a strong emphasis on energy conservation, waste minimization and superior indoor air quality (IAQ). To achieve the IAQ goal, the building utilizes a series of air cleaning technologies for treating the air entering the building. These technologies include an initial water wash followed by ultraviolet light treatment and biolfiltration using a greenhouse located on the roof and numerous plants distributed throughout the building. Even with the extensive treatment of makeup air and room air in the PBC, a recent study found that the concentrations of common volatile organic compounds and aldehydes appear to rise incrementally as the air passes through the building from the supply to the exhaust. This finding highlights the need to consider the minimization of chemical sources in buildings in combination with the use of advanced air cleaning technologies when seeking to achieve superior IAQ. The goal of this project was to identify potential source materials for indoor chemicals in the PBC. Samples of building materials, including wood paneling (polished and unpolished), drywall, and plastic from a hydroponic drum that was part of the air cleaning system, were collected from the building for testing. All materials were collected from the PBC building and shipped to the Lawrence Berkeley National Laboratory (LBNL) for testing. The materials were pre-conditioned for two different time periods before measuring material and chemical specific emission factors for a range of VOCs and Aldehydes. Of the six materials tested, we found that the highest emitter of formaldehyde was new plywood paneling. Although polish and paint contribute to some VOC emissions, the main influence of the polish was in altering the capacity of the surface to accumulate formaldehyde. Neither the new nor aged polish contributed

  20. ALDEHYDE AND OTHER VOLATILE ORGANIC CHEMICAL EMISSIONS IN FOUR FEMA TEMPORARY HOUSING UNITS ? FINAL REPORT

    SciTech Connect

    Salazar, Olivia; Maddalena, Randy L.; Russell, Marion; Sullivan, Douglas P.; Apte, Michael G.

    2008-05-04

    Four unoccupied FEMA temporary housing units (THUs) were studied to assess their indoor emissions of volatile organic compounds including formaldehyde. Measurement of whole-THU VOC and aldehyde emission factors (mu g h-1 per m2 of floor area) for each of the four THUs were made at FEMA's Purvis MS staging yard using a mass balance approach. Measurements were made in the morning, and again in the afternoon in each THU. Steady-state indoor formaldehyde concentrations ranged from 378 mu g m-3 (0.31ppm) to 632 mu g m-3 (0.52 ppm) in the AM, and from 433 mu g m-3 (0.35 ppm) to 926 mu g m-3 (0.78 ppm) in the PM. THU air exchange rates ranged from 0.15 h-1 to 0.39 h-1. A total of 45 small (approximately 0.025 m2) samples of surface material, 16 types, were collected directly from the four THUs and shipped to Lawrence Berkeley Laboratory. The material samples were analyzed for VOC and aldehyde emissions in small stainless steel chambers using a standard, accurate mass balance method. Quantification of VOCs was done via gas chromatography -- mass spectrometry and low molecular weight aldehydes via high performance liquid chromatography. Material specific emission factors (mu g h-1 per m2 of material) were quantified. Approximately 80 unique VOCs were tentatively identified in the THU field samples, of which forty-five were quantified either because of their toxicological significance or because their concentrations were high. Whole-trailer and material specific emission factors were calculated for 33 compounds. The THU emission factors and those from their component materials were compared against those measured from other types of housing and the materials used in their construction. Whole THU emission factors for most VOCs were typically similar to those from comparative housing. The three exceptions were exceptionally large emissions of formaldehyde and TMPD-DIB (a common plasticizer in vinyl products), and somewhat elevated for phenol. Of these three compounds

  1. Recovery of organic acids

    DOEpatents

    Verser, Dan W.; Eggeman, Timothy J.

    2009-10-13

    A method is disclosed for the recovery of an organic acid from a dilute salt solution in which the cation of the salt forms an insoluble carbonate salt. A tertiary amine and CO.sub.2 are introduced to the solution to form the insoluble carbonate salt and a complex between the acid and an amine. A water immiscible solvent, such as an alcohol, is added to extract the acid/amine complex from the dilute salt solution to a reaction phase. The reaction phase is continuously dried and a product between the acid and the solvent, such as an ester, is formed.

  2. Recovery of organic acids

    SciTech Connect

    Verser, Dan W.; Eggeman, Timothy J.

    2011-11-01

    A method is disclosed for the recovery of an organic acid from a dilute salt solution in which the cation of the salt forms an insoluble carbonate salt. A tertiary amine and CO.sub.2 are introduced to the solution to form the insoluble carbonate salt and a complex between the acid and an amine. A water immiscible solvent, such as an alcohol, is added to extract the acid/amine complex from the dilute salt solution to a reaction phase. The reaction phase is continuously dried and a product between the acid and the solvent, such as an ester, is formed.

  3. Microorganisms for producing organic acids

    SciTech Connect

    Pfleger, Brian Frederick; Begemann, Matthew Brett

    2014-09-30

    Organic acid-producing microorganisms and methods of using same. The organic acid-producing microorganisms comprise modifications that reduce or ablate AcsA activity or AcsA homolog activity. The modifications increase tolerance of the microorganisms to such organic acids as 3-hydroxypropionic acid, acrylic acid, propionic acid, lactic acid, and others. Further modifications to the microorganisms increase production of such organic acids as 3-hydroxypropionic acid, lactate, and others. Methods of producing such organic acids as 3-hydroxypropionic acid, lactate, and others with the modified microorganisms are provided. Methods of using acsA or homologs thereof as counter-selectable markers are also provided.

  4. Impact of lipid oxidation-derived aldehydes and ascorbic acid on the antioxidant activity of model melanoidins.

    PubMed

    Kitrytė, Vaida; Adams, An; Venskutonis, Petras Rimantas; De Kimpe, Norbert

    2012-12-01

    As the heat-induced formation of antioxidants throughout the Maillard reaction is known, this study was undertaken to evaluate the impact of lipid oxidation-derived aldehydes and ascorbic acid in Maillard model systems on the resulting antioxidant activity. For this purpose, various fractions of melanoidin-like polycondensation products were obtained from mixtures of amino acids (glycine, lysine, arginine) and lipid oxidation-derived aldehydes (hexanal, (E)-2-hexenal), in the presence or absence of glucose or ascorbic acid. All fractions showed a significant radical scavenging capacity (DPPH assay) and ferric reducing power (FRAP assay). The activity varied according to the composition of the model system tested, although some similar trends were discovered in both assays applied. The presence of lipid oxidation products in the browning products augmented the antioxidant activity in specific cases. For instance, the combined presence of arginine, hexanal and glucose in heated model systems resulted in a significantly higher antioxidant capacity. With an exception of ascorbic acid-containing model systems, melanoidin-like polycondensation products possessed significantly stronger antioxidant activities than the corresponding unheated initial reactant mixtures. Water-soluble high molecular weight (>12kDa) and nonsoluble fractions comprised the major part of the antioxidants derived from amino acid/lipid oxidation product model systems, with or without glucose or ascorbic acid. PMID:22953854

  5. Alcohol fuel use: Implications for atmospheric levels of aldehydes, organic nitrates, pans, and peroxides: Separating sources using carbon isotopes

    SciTech Connect

    Gaffney, J.S.; Tanner, R.L.

    1988-01-01

    We have developed DiNitroPhenylHydrazone (DNPH) derivatization--high performance liquid chromatographic methods for measuring aldehydes in ambient samples with detection limits of approximately 1ppbV. These methods can be used for air or precipitation studies, and have been used for indoor measurements at much higher levels using shorter integration times. We are using gas chromatographs with electron capture detection (GCECD) to measure ambient levels of peroxyacyl nitrates and organic nitrates. Diffusion tubes with synthetically produced organic nitrates in n-tridecane solution are used to calibrate these systems. These compounds are important means of transporting NO/sub x/ over large scales due to their reduced tropospheric reactivity, low water solubilities, photolytic, and thermal stability. Their chemistries are coupled to aldehyde chemistry and are important greenhouse gases as well as phytotoxins. We have completed preliminary studies in Rio de Janeiro examining the atmospheric chemistry consequences of ethanol fuel usage. The urban air mass has been effected by the direct uncontrolled usage of ethanolgasoline and ethanoldiesel mixtures. We are exploring the use of luminol chemiluminescent detection of peroxides using gas chromatography to separate the various organic and inorganic peroxides. These compounds are coupled to the aldehyde chemistry, particularly in remote chemistries down-wind of urban sources. 13 refs.

  6. Toxicity of polyunsaturated aldehydes of diatoms to Indo-Pacific bioindicator organism Echinometra mathaei.

    PubMed

    Sartori, Davide; Gaion, Andrea

    2016-01-01

    Although it is well known suitability of early developmental stages of sea urchin as recommended model for pollutant toxicity testing, little is known about the sensitivity of Indo-Pacific species Echinometra mathaei to polyunsaturated aldehydes. In this study, the effect of three short chain aldehydes, 2,4-decadienal (DD), 2,4-octadienal (OD) and 2,4-heptadienal (HD), normally found in many diatoms, such as Skeletonema costatum, Skeletonema marinoi and Thalassiosira rotula, was evaluated on larval development of E. mathaei embryos. Aldehydes affected larval development in a dose-dependent manner, in particular HD>OD>DD; the results of this study highlighted the higher sensitivity of this species toward aldehydes compared with data registered for other sea urchin species. In comparison with studies reported in the literature, contrasting results were observed during our tests; therefore, an increasing toxic effect was registered with decreasing the chain length of aldehydes. This work could provide new insights in the development of new toxicological assays toward most sensitive species. PMID:25945412

  7. Characterization of polar organosulfates in secondary organic aerosol from the unsaturated aldehydes 2-E-pentenal, 2-E-hexenal, and 3-Z-hexenal

    NASA Astrophysics Data System (ADS)

    Safi Shalamzari, Mohammad; Vermeylen, Reinhilde; Blockhuys, Frank; Kleindienst, Tadeusz E.; Lewandowski, Michael; Szmigielski, Rafal; Rudzinski, Krzysztof J.; Spólnik, Grzegorz; Danikiewicz, Witold; Maenhaut, Willy; Claeys, Magda

    2016-06-01

    We show in the present study that the unsaturated aldehydes 2-E-pentenal, 2-E-hexenal, and 3-Z-hexenal are biogenic volatile organic compound (BVOC) precursors for polar organosulfates with molecular weights (MWs) 230 and 214, which are also present in ambient fine aerosol from a forested site, i.e., K-puszta, Hungary. These results complement those obtained in a previous study showing that the green leaf aldehyde 3-Z-hexenal serves as a precursor for MW 226 organosulfates. Thus, in addition to isoprene, the green leaf volatiles (GLVs) 2-E-hexenal and 3-Z-hexenal, emitted due to plant stress (mechanical wounding or insect attack), and 2-E-pentenal, a photolysis product of 3-Z-hexenal, should be taken into account for secondary organic aerosol and organosulfate formation. Polar organosulfates are of climatic relevance because of their hydrophilic properties and cloud effects. Extensive use was made of organic mass spectrometry (MS) and detailed interpretation of MS data (i.e., ion trap MS and accurate mass measurements) to elucidate the chemical structures of the MW 230, 214 and 170 organosulfates formed from 2-E-pentenal and indirectly from 2-E-hexenal and 3-Z-hexenal. In addition, quantum chemical calculations were performed to explain the different mass spectral behavior of 2,3-dihydroxypentanoic acid sulfate derivatives, where only the isomer with the sulfate group at C-3 results in the loss of SO3. The MW 214 organosulfates formed from 2-E-pentenal are explained by epoxidation of the double bond in the gas phase and sulfation of the epoxy group with sulfuric acid in the particle phase through the same pathway as that proposed for 3-sulfooxy-2-hydroxy-2-methylpropanoic acid from the isoprene-related α,β-unsaturated aldehyde methacrolein in previous work (Lin et al., 2013). The MW 230 organosulfates formed from 2-E-pentenal are tentatively explained by a novel pathway, which bears features of the latter pathway but introduces an additional hydroxyl group at the

  8. Characterization of polar organosulfates in secondary organic aerosol from the unsaturated aldehydes 2-E-pentenal, 2-E-hexenal, and 3-Z-hexenal

    NASA Astrophysics Data System (ADS)

    Shalamzari, M. S.; Vermeylen, R.; Blockhuys, F.; Kleindienst, T. E.; Lewandowski, M.; Szmigielski, R.; Rudzinski, K. J.; Spólnik, G.; Danikiewicz, W.; Maenhaut, W.; Claeys, M.

    2015-10-01

    We show in the present study that the unsaturated aldehydes, 2-E-pentenal, 2-E-hexenal and 3-Z-hexenal, are biogenic volatile organic compound (BVOC) precursors for polar organosulfates with molecular weights (MWs) 230 and 214, which are also present in ambient fine aerosol from a forested site, i.e., K-puszta, Hungary. These results complement those obtained in a previous study showing that the green leaf aldehyde 3-Z-hexenal serves as a precursor for MW 226 organosulfates. Thus, in addition to isoprene, the green leaf volatiles 2-E-hexenal and 3-Z-hexenal, emitted due to plant stress (mechanical wounding or insect attack), and 2-E-pentenal, a photolysis product of 3-Z-hexenal, should be taken into account for secondary organic aerosol and organosulfate formation. Polar organosulfates are of climatic relevance because of their hydrophilic properties and cloud effects. Extensive use was made of organic mass spectrometry (MS) and detailed interpretation of MS data (i.e., ion trap MS and accurate mass measurements) to elucidate the chemical structures of the MW 230, 214 and 170 organosulfates formed from 2-E-pentenal and indirectly from 2-E-hexenal and 3-Z-hexenal. In addition, quantum chemical calculations were performed to explain the different mass spectral behavior of 2,3-dihydroxypentanoic acid sulfate derivatives, where only the isomer with the sulfate group at C-3 results in the loss of SO3. The MW 214 organosulfates formed from 2-E-pentenal are explained by epoxidation of the double bond in the gas phase and sulfation of the epoxy group with sulfuric acid in the particle phase through the same pathway as that proposed for 3-sulfoxy-2-hydroxy-2-methylpropanoic acid from the isoprene-related α, β-unsaturated aldehyde methacrolein in previous work (Lin et al., 2013). The MW 230 organosulfates formed from 2-E-pentenal are tentatively explained by a novel pathway, which bears features of the latter pathway but introduces an additional hydroxyl group at the C-4

  9. Heterologous Expression of Aldehyde Dehydrogenase from Saccharomyces cerevisiae in Klebsiella pneumoniae for 3-Hydroxypropionic Acid Production from Glycerol.

    PubMed

    Wang, Kang; Wang, Xi; Ge, Xizhen; Tian, Pingfang

    2012-09-01

    3-Hydroxypropionic acid (3-HP) is a commercially valuable platform compound. Klebsiella pneumoniae has been concerned as an appropriate host for 3-HP production because of its robust capacity to metabolize glycerol. Glycerol conversion to 3-HP in K. pneumoniae comprises two successive reactions: glycerol dehydratase catalyzes glycerol to 3-hydroxypropionaldehyde (3-HPA); aldehyde dehydrogenase catalyzes 3-HPA to 3-HP. Previous studies focusing on inducible expression of aldehyde dehydrogenase have shown defects of high cost of inducer and low catalytic activity due to inclusion body. Here we show a different strategy that a native promoter in the host K. pneumoniae was used to drive the heterologous expression of aldehyde dehydrogenase gene ald4 from Saccharomyces cerevisiae. The 3-HP yield of the recombinant reached a peak of 4.23 g/L at log phase, but it decreased during later period of fermentation. Except the validation of high activity of ald4, particularly, the 3-HP formation was uncovered to be closely coupled with cell division, and the lacking of NAD and ATP at latter fermentation phase became the bottleneck for cell growth and 3-HP accumulation. Furthermore, 3-HP is postulated to be converted to 3-HPA via feedback inhibition or other metabolite via unknown mechanism. Since glycerol dissimilation is a common mechanism in a variety of bacteria, the expression strategy using native promoter and implications may provide significant insight into the metabolic engineering for 3-HP production. PMID:23997342

  10. Molecular characterization and organ-specific expression of the gene that encodes betaine aldehyde dehydrogenase from the white shrimp Litopenaeus vannamei in response to osmotic stress.

    PubMed

    Delgado-Gaytán, María F; Hernández-Palomares, Magally L E; Soñanez-Organis, José G; Muhlia-Almazán, Adriana; Sánchez-Paz, Arturo; Stephens-Camacho, Norma A; Valenzuela-Soto, Elisa M; Rosas-Rodríguez, Jesús A

    2015-11-01

    Crustaceans overcome osmotic disturbances by regulating their intracellular concentration of ions and osmolytes. Glycine betaine (GB), an osmolyte accumulated in response to hyperosmotic stress, is synthesized by betaine aldehyde dehydrogenase (BADH EC 1.2.1.8) through the oxidation of betaine aldehyde. A partial BADH cDNA sequence from the white shrimp Litopenaeus vannamei was obtained and its organ-specific expression during osmotic stress (low and high salinity) was evaluated. The partial BADH cDNA sequence (LvBADH) is 1103bp long and encodes an open reading frame for 217 protein residues. The amino acid sequence of LvBADH is related to that of other BADHs, TMABA-DH and ALDH9 from invertebrate and vertebrate homologues, and includes the essential domains of their function and regulation. LvBADH activity and mRNA expression were detected in the gills, hepatopancreas and muscle with the highest levels in the hepatopancreas. LvBADH mRNA expression increased 2-3-fold in the hepatopancreas and gills after 7days of osmotic variation (25 and 40ppt). In contrast, LvBADH mRNA expression in muscle decreased 4-fold and 15-fold after 7days at low and high salinity, respectively. The results indicate that LvBADH is ubiquitously expressed, but its levels are organ-specific and regulated by osmotic stress, and that LvBADH is involved in the cellular response of crustaceans to variations in environmental salinity. PMID:26219579

  11. Sustainable synthesis of aldehydes, ketones or acids from neat alcohols using nitrogen dioxide gas, and related reactions.

    PubMed

    Naimi-Jamal, M Reza; Hamzeali, Hamideh; Mokhtari, Javad; Boy, Jürgen; Kaupp, Gerd

    2009-01-01

    Benzylic alcohols are quantitatively oxidized by gaseous nitrogen dioxide to give pure aromatic aldehydes. The reaction gas mixtures are transformed to nitric acid, which renders the processes free of waste. The exothermic gas-liquid or gas-solid reactions profit from the solubility of nitrogen dioxide in the neat benzylic alcohols. The acid formed impedes further oxidation of the benzaldehydes. The neat isolated benzaldehydes and nitrogen dioxide quantitatively give the benzoic acids. Solid long-chain primary alcohols are directly and quantitatively oxidized with nitrogen dioxide gas to give the fatty acids in the solid state. The oxidations with ubiquitous nitrogen dioxide are extended to solid heterocyclic thioamides, which gives disulfides, and to diphenylamine, which gives tetraphenylhydrazine. These sustainable (green) specific oxidation procedures produce no dangerous residues from the oxidizing agent or from auxiliaries. PMID:19115303

  12. Oxidation of N-Nitrosoalkylamines by human cytochrome P450 2A6: sequential oxidation to aldehydes and carboxylic acids and analysis of reaction steps.

    PubMed

    Chowdhury, Goutam; Calcutt, M Wade; Guengerich, F Peter

    2010-03-12

    Cytochrome P450 (P450) 2A6 activates nitrosamines, including N,N-dimethylnitrosamine (DMN) and N,N-diethylnitrosamine (DEN), to alkyl diazohydroxides (which are DNA-alkylating agents) and also aldehydes (HCHO from DMN and CH(3)CHO from DEN). The N-dealkylation of DMN had a high intrinsic kinetic deuterium isotope effect ((D)k(app) approximately 10), which was highly expressed in a variety of competitive and non-competitive experiments. The (D)k(app) for DEN was approximately 3 and not expressed in non-competitive experiments. DMN and DEN were also oxidized to HCO(2)H and CH(3)CO(2)H, respectively. In neither case was a lag observed, which was unexpected considering the k(cat) and K(m) parameters measured for oxidation of DMN and DEN to the aldehydes and for oxidation of the aldehydes to the carboxylic acids. Spectral analysis did not indicate strong affinity of the aldehydes for P450 2A6, but pulse-chase experiments showed only limited exchange with added (unlabeled) aldehydes in the oxidations of DMN and DEN to carboxylic acids. Substoichiometric kinetic bursts were observed in the pre-steady-state oxidations of DMN and DEN to aldehydes. A minimal kinetic model was developed that was consistent with all of the observed phenomena and involves a conformational change of P450 2A6 following substrate binding, equilibrium of the P450-substrate complex with a non-productive form, and oxidation of the aldehydes to carboxylic acids in a process that avoids relaxation of the conformation following the first oxidation (i.e. of DMN or DEN to an aldehyde). PMID:20061389

  13. Carboxylic Acid Photochemistry is a Marine Source of Glyoxal and Other Aldehydes

    NASA Astrophysics Data System (ADS)

    Chiu, R.; Gonzalez, L.; Tinel, L.; George, C.; Volkamer, R. M.

    2015-12-01

    Glyoxal is a highly water-soluble precursor in secondary organic aerosol (SOA) formation. Over land, glyoxal is known to be produced by the oxidation of volatile organic carbon (VOC) from both anthropogenic and natural sources. However, marine sources are still not well understood. Previous studies above the remote Pacific Ocean have detected typical glyoxal mixing ratios of 30-40 pptv, concentrations too high to be explained with current chemical understanding or atmospheric models. Because the lifetime of glyoxal is very short, the glyoxal found must have originated from, rather than been transported to, the open ocean. Furthermore, eddy covariance measurements indicate that an organic surface microlayer may be producing the glyoxal by as yet unknown processes. Here we present laboratory studies of the formation of glyoxal from carboxylic acids. Nonanoic, octanoic, and heptanoic acids floated on water and subjected to ultraviolet light are converted into their equivalent alkenals. Subsequent ozonolysis of the alkenals leads to the formation of glyoxal. We employ a PTR-MS to detect the alkenals, and a cavity-enhanced DOAS to detect the glyoxal. Considering the ubiquitous occurrence of carboxylic acids and their derivatives in the environment, this mechanism has the potential to be a significant source of glyoxal in the atmosphere.

  14. Magnesium Lewis Acid Assisted Oxidative Bromoetherification Involving Bromine Transfer from Alkyl Bromides with Aldehydes by Umpolung of Bromide.

    PubMed

    Moriyama, Katsuhiko; Nishinohara, Chihiro; Togo, Hideo

    2016-08-16

    An oxidative bromoetherification involving a bromine transfer from alkyl bromides upon reacting them with aldehydes in a Grignard reaction with a concurrent oxidation of bromide was developed to provide substituted tetrahydrofurans in high yields. This reaction, which proceeds through two types of bromine transfer, was promoted by the addition of a Brønsted acid. Mechanistic studies suggested that a magnesium Lewis acid activates hypobromate, which is generated in situ from the reaction of bromide and Oxone to improve the electrophilicity of the bromonium ion (Br(+) ) for the oxidative bromoetherification of alkenyl alcohols. Furthermore, the magnesium Lewis acid catalyzed oxidative bromoetherification of an alkenyl alcohol proceeded to provide a cyclization product in 92 % yield. PMID:27304660

  15. Comparative Study on Single-Molecule Junctions of Alkane- and Benzene-Based Molecules with Carboxylic Acid/Aldehyde as the Anchoring Groups.

    PubMed

    Chen, Fang; Peng, Lin-Lu; Hong, Ze-Wen; Mao, Jin-Chuan; Zheng, Ju-Fang; Shao, Yong; Niu, Zhen-Jiang; Zhou, Xiao-Shun

    2016-12-01

    We have measured the alkane and benzene-based molecules with aldehyde and carboxylic acid as anchoring groups by using the electrochemical jump-to-contact scanning tunneling microscopy break junction (ECSTM-BJ) approach. The results show that molecule with benzene backbone has better peak shape and intensity than those with alkane backbone. Typically, high junction formation probability for same anchoring group (aldehyde and carboxylic acid) with benzene backbone is found, which contributes to the stronger attractive interaction between Cu and molecules with benzene backbone. The present work shows the import role of backbone in junction, which can guide the design molecule to form effective junction for studying molecular electronics. PMID:27566686

  16. Pathways for oxidation of low density lipoprotein by myeloperoxidase: tyrosyl radical, reactive aldehydes, hypochlorous acid and molecular chlorine.

    PubMed

    Heinecke, J W

    1997-01-01

    Many lines of evidence implicate oxidation of low density lipoprotein (LDL) in the pathogenesis of atherosclerosis, a chronic inflammatory disease. The physiologically relevant mechanisms have not been identified, but phagocytic white cells may play an important role because macrophage-rich lesions characterize the disorder. Recent studies have shown that myeloperoxidase, a heme enzyme secreted only by phagocytes, is present in human atherosclerotic tissue. The enzyme is a potent catalyst of LDL oxidation in vitro, it co-localizes with macrophages in lesions, and it generates products that are detectable in atherosclerotic plaque. These findings suggest that myeloperoxidase may promote LDL oxidation in the artery wall. This article reviews the enzyme's ability to generate a range of oxidants, including tyrosyl radical, reactive aldehydes, hypochlorous acid and molecular chlorine. These products have the potential to damage host molecules as well as microbes, suggesting a mechanism that may contribute to atherosclerotic vascular disease. PMID:9259996

  17. Silver(I) as a widely applicable, homogeneous catalyst for aerobic oxidation of aldehydes toward carboxylic acids in water—“silver mirror”: From stoichiometric to catalytic

    PubMed Central

    Liu, Mingxin; Wang, Haining; Zeng, Huiying; Li, Chao-Jun

    2015-01-01

    The first example of a homogeneous silver(I)-catalyzed aerobic oxidation of aldehydes in water is reported. More than 50 examples of different aliphatic and aromatic aldehydes, including natural products, were tested, and all of them successfully underwent aerobic oxidation to give the corresponding carboxylic acids in extremely high yields. The reaction conditions are very mild and greener, requiring only a very low silver(I) catalyst loading, using atmospheric oxygen as the oxidant and water as the solvent, and allowing gram-scale oxidation with only 2 mg of our catalyst. Chromatography is completely unnecessary for purification in most cases. PMID:26601150

  18. Microwave-Assisted Condensation Reactions of Acetophenone Derivatives and Activated Methylene Compounds with Aldehydes Catalyzed by Boric Acid under Solvent-Free Conditions.

    PubMed

    Brun, Elodie; Safer, Abdelmounaim; Carreaux, François; Bourahla, Khadidja; L'helgoua'ch, Jean-Martial; Bazureau, Jean-Pierre; Villalgordo, Jose Manuel

    2015-01-01

    We here disclosed a new protocol for the condensation of acetophenone derivatives and active methylene compounds with aldehydes in the presence of boric acid under microwave conditions. Implementation of the reaction is simple, healthy and environmentally friendly owing to the use of a non-toxic catalyst coupled to a solvent-free procedure. A large variety of known or novel compounds have thus been prepared, including with substrates bearing acid or base-sensitive functional groups. PMID:26111185

  19. Aldehyde dehydrogenase protein superfamily in maize.

    PubMed

    Zhou, Mei-Liang; Zhang, Qian; Zhou, Ming; Qi, Lei-Peng; Yang, Xiong-Bang; Zhang, Kai-Xuan; Pang, Jun-Feng; Zhu, Xue-Mei; Shao, Ji-Rong; Tang, Yi-Xiong; Wu, Yan-Min

    2012-11-01

    Maize (Zea mays ssp. mays L.) is an important model organism for fundamental research in the agro-biotechnology field. Aldehydes were generated in response to a suite of environmental stresses that perturb metabolism including salinity, dehydration, desiccation, and cold and heat shock. Many biologically important aldehydes are metabolized by the superfamily of NAD(P)(+)-dependent aldehyde dehydrogenases. Here, starting from the database of Z. mays, we identified 28 aldehyde dehydrogenase (ALDH) genes and 48 transcripts by the in silico cloning method using the ALDH-conserved domain amino acid sequence of Arabidopsis and rice as a probe. Phylogenetic analysis shows that all 28 members of the ALDH gene families were classified to ten distinct subfamilies. Microarray data and quantitative real-time PCR analysis reveal that ZmALDH9, ZmALDH13, and ZmALDH17 genes involve the function of drought stress, acid tolerance, and pathogens infection. These results suggested that these three ZmALDH genes might be potentially useful in maize genetic improvement. PMID:22983498

  20. Volatile aldehydes in libraries and archives

    NASA Astrophysics Data System (ADS)

    Fenech, Ann; Strlič, Matija; Kralj Cigić, Irena; Levart, Alenka; Gibson, Lorraine T.; de Bruin, Gerrit; Ntanos, Konstantinos; Kolar, Jana; Cassar, May

    2010-06-01

    Volatile aldehydes are produced during degradation of paper-based materials. This may result in their accumulation in archival and library repositories. However, no systematic study has been performed so far. In the frame of this study, passive sampling was carried out at ten locations in four libraries and archives. Despite the very variable sampling locations, no major differences were found, although air-filtered repositories were found to have lower concentrations while a non-ventilated newspaper repository exhibited the highest concentrations of volatile aldehydes (formaldehyde, acetaldehyde, furfural and hexanal). Five employees in one institution were also provided with personal passive samplers to investigate employees' exposure to volatile aldehydes. All values were lower than the presently valid exposure limits. The concentration of volatile aldehydes, acetic acid, and volatile organic compounds (VOCs) in general was also compared with that of outdoor-generated pollutants. It was evident that inside the repository and particularly inside archival boxes, the concentration of VOCs and acetic acid was much higher than the concentration of outdoor-generated pollutants, which are otherwise more routinely studied in connection with heritage materials. This indicates that further work on the pro-degradative effect of VOCs on heritage materials is necessary and that monitoring of VOCs in heritage institutions should become more widespread.

  1. Characterization of polar organosulfates in secondary organic aerosol from the unsaturated aldehydes 2-E-pentenal, 2-E-hexenal, and 3-Z-hexenal

    EPA Science Inventory

    We show in the present study that the unsaturated aldehydes 2-E-pentenal, 2-E-hexenal, and 3-Z-hexenal are biogenic volatile organic compound (BVOC) precursors for polar organosulfates with molecular weights (MWs) 230 and 214, which are also present in ambient fine aerosol from a...

  2. Organic Acids by Ion Chromatography

    NASA Astrophysics Data System (ADS)

    Rich, William E.; Johnson, Edward; Lois, Louis; Stafford, Brian E.; Kabra, Pokar M.; Marton, Laurence J.

    The presence of increased levels of various organic acids in physiological fluids such as serum, plasma, and urine has been correlated with a variety of diseases (1). Although some are rare, others such as lactic acidosis and hyperoxaluria are more widespread (2, 3). The estimation of organic acids in biological fluids has long been an analytical problem owing to the nature of the samples and the hydrophilic behavior of the various acids.

  3. Analysis of Organic Acids.

    ERIC Educational Resources Information Center

    Griswold, John R.; Rauner, Richard A.

    1990-01-01

    Presented are the procedures and a discussion of the results for an experiment in which students select unknown carboxylic acids, determine their melting points, and investigate their solubility behavior in water and ethanol. A table of selected carboxylic acids is included. (CW)

  4. Analysis of volatile aldehyde biomarkers in human blood by derivatization and dispersive liquid-liquid microextraction based on solidification of floating organic droplet method by high performance liquid chromatography.

    PubMed

    Lili, Lv; Xu, Hui; Song, Dandan; Cui, Yanfang; Hu, Sheng; Zhang, Ganbing

    2010-04-16

    A new dispersive liquid-liquid microextraction based on solidification of floating organic droplet method (DLLME-SFO) was developed for the determination of volatile aldehyde biomarkers (hexanal and heptanal) in human blood samples. In the derivatization and extraction procedure, 2,4-dinitrophenylhydrazine (DNPH) as derivatization reagent and formic acid as catalyzer were injected into the sample solution for derivatization with aldehydes, then the formed hydrazones was rapidly extracted by dispersive liquid-liquid microextraction with 1-dodecanol as extraction solvent. After centrifugation, the floated droplet was solidified in an ice bath and was easily removed for analysis. The effects of various experimental parameters on derivatization and extraction conditions were studied, such as the kind and volume of extraction solvent and dispersive solvent, the amount of derivatization reagent, derivatization temperature and time, extraction time and salt effect. The limit of detections (LODs) for hexanal and heptanal were 7.90 and 2.34nmolL(-1), respectively. Good reproducibility and recovery of the method were also obtained. The proposed method is an alternative approach to the quantification of volatile aldehyde biomarkers in complex biological samples, being more rapid and simpler and providing higher sensitivity compared with the traditional dispersive liquid-liquid microextraction (DLLME) methods. PMID:20181347

  5. A direct RP-HPLC method for the determination of furanic aldehydes and acids in honey.

    PubMed

    Spano, Nadia; Ciulu, Marco; Floris, Ignazio; Panzanelli, Angelo; Pilo, Maria I; Piu, Paola C; Salis, Severyn; Sanna, Gavino

    2009-04-15

    In this study 5-hydroxymethyl-2-furaldehyde (HMF), 2-furaldehyde, 3-furaldehyde, 2-furoic acid and 3-furoic acid are contemporarily determined in honey using a swift and direct RP-HPLC approach. The validation protocol was performed in terms of detection and quantification limits, precision (by repeatability and reproducibility), linearity and accuracy (by recovery tests); the acceptability of the precision and accuracy results was positively verified using Horwitz's model and AOAC guidelines, respectively. The method was tested on 18 honey samples of different ages, and botanical and geographical origin. HMF and 2-furaldehyde correlated highly with the age of the samples, whereas no correlation was observed with regards to 2-furaldehyde and 2-furoic acid. Hypotheses relating to the formation of minority furanic compounds are also proposed. PMID:19174244

  6. Asymmetric counteranion-directed Lewis acid organocatalysis for the scalable cyanosilylation of aldehydes

    PubMed Central

    Zhang, Zhipeng; Bae, Han Yong; Guin, Joyram; Rabalakos, Constantinos; van Gemmeren, Manuel; Leutzsch, Markus; Klussmann, Martin; List, Benjamin

    2016-01-01

    Due to the high versatility of chiral cyanohydrins, the catalytic asymmetric cyanation reaction of carbonyl compounds has attracted widespread interest. However, efficient protocols that function at a preparative scale with low catalyst loading are still rare. Here, asymmetric counteranion-directed Lewis acid organocatalysis proves to be remarkably successful in addressing this problem and enabled a molar-scale cyanosilylation in quantitative yield and with excellent enantioselectivity. Also, the catalyst loading could be lowered to a part-per-million level (50 ppm: 0.005 mol%). A readily accessible chiral disulfonimide was used, which in combination with trimethylsilyl cyanide, turned into the active silylium Lewis acid organocatalyst. The nature of a peculiar phenomenon referred to as a “dormant period”, which is mainly induced by water, was systematically investigated by means of in situ Fourier transform infrared analysis. PMID:27530470

  7. Separators and organics for lead-acid batteries

    NASA Astrophysics Data System (ADS)

    Böhnstedt, Werner

    This review discusses various interactions between organic compounds, brought into the lead-acid battery via the separator, and their subsequent effect on battery performance. Historically, the interrelationship started with certain 'expander' actions on the lead morphology due to lignins, which leached out of the wooden separators of that time. Synthetic separator materials did not show this effect, but gained acceptance as they were far more stable in the hostile battery environment. The partially hydrophobic character of synthetic separators has been overcome by organic surfactants. Other organic compounds have been found to improve further the stability of separators against oxidation. Special organic molecules, namely aldehydes and ketones, have been identified to retard, or even suppress, the adverse effects of metals such as antimony, and thus prolong the cycle-life of traction batteries in heavy-duty applications or reduce water loss from automotive batteries. Knowledge about these interactions has opened ways to improve separators.

  8. Secondary Organic Aerosol and Brown Carbon Formation in the Sunlit Aqueous Phase: Aldehyde Photooxidation in the Presence of Ammonium Salts and Amines

    NASA Astrophysics Data System (ADS)

    De Haan, D. O.; Galloway, M. M.; Sharp, K. D.; Jiménez, N. G.

    2014-12-01

    The chemistry of water-soluble carbonyl compounds in clouds is now acknowledged as an important source of secondary organic aerosol. These reactive carbonyl compounds are oxidized to carboxylic acids and form oligomers by radical-radical reactions and by "dark reactions" with ammonium salts (AS) and/or amines. The latter class of reactions also produces light-absorbing brown carbon compounds, especially reactions involving methylglyoxal or glyoxal and amines. However, recent work has found that UV light fades the color of glyoxal + AS and methylgyloxal + AS reaction mixtures. We recently studied aldehyde-AS-amine reactions in sunlight and in control vessels at the same temperature to determine the effects of solar radiation on the aqueous-phase production of brown carbon. In sunlight, methylglyoxal reaction mixtures lost their initial color and failed to brown, indicating the photolytic loss of reactants and/or pre-brown intermediates. In many other reactions, brown products are lost to photolysis, reducing the overall browning of solutions exposed to sunlight. In other experiments, hydrogen peroxide was added to generate OH radicals by photolysis. In the presence of OH radicals, some carbonyl compound mixtures (e.g. those containing hydroxyacetone or glycolaldehyde) browned more rapidly when exposed to sunlight. This indicates the existence of uncharacterized photooxidative browning pathways involving aqueous-phase OH radicals, carbonyls, ammonium salts, and/or amine compounds.

  9. Origins of stereoselectivities in chiral phosphoric acid catalyzed allylborations and propargylations of aldehydes.

    PubMed

    Wang, Hao; Jain, Pankaj; Antilla, Jon C; Houk, K N

    2013-02-01

    The chiral BINOL-phosphoric acid catalyzed allylboration and propargylation reactions are studied with density functional theory (B3LYP and B3LYP-D3). Two different models were recently proposed for these reactions by Goodman and our group, respectively. In Goodman's model for allylborations, the catalyst interacts with the boronate pseudoaxial oxygen. By contrast, our model for propargylations predicts that the catalyst interacts with the boronate pseudoequatorial oxygen. In both models, the phosphoric acid stabilizes the transition state by forming a strong hydrogen bond with the oxygen of the boronate and is oriented by a formyl hydrogen bond (Goodman model) and by other electrostatic attractions in our model. Both of these models have now been reinvestigated for both allylborations and propargylations. For the most effective catalyst for these reactions, the lowest energy transition state corresponds to Goodman's axial model, while the best transition state leading to the minor enantiomer involves the equatorial model. The high enantioselectivity observed with only the bulkiest catalyst arises from the steric interactions between the substrates and the bulky groups on the catalyst, and the resulting necessity for distortion of the catalyst in the disfavored transition state. PMID:23298338

  10. Origins of Stereoselectivities in Chiral Phosphoric Acid-Catalyzed Allylborations and Propargylations of Aldehydes

    PubMed Central

    Wang, Hao; Jain, Pankaj; Antilla, Jon C.; Houk, K. N.

    2013-01-01

    The chiral BINOL-phosphoric acid catalyzed allylboration and propargylation reactions are studied with density functional theory (B3LYP and B3LYP-D3). Two different models were recently proposed for these reactions by Goodman and our group, respectively. In Goodman's model for allylborations, the catalyst interacts with the boronate pseudo-axial oxygen. By contrast, our model for propargylations predicts that the catalyst interacts with the boronate pseudo-equatorial oxygen. In both models, the phosphoric acid stabilizes the transition state by forming a strong hydrogen bond with the oxygen of the boronate, and is oriented by a formyl hydrogen bond (Goodman model), and by other electrostatic attractions in our model. Both of these models have now been reinvestigated for both allylborations and propargylations. For the most effective catalyst for these reactions, the lowest energy transition state corresponds to Goodman's axial model, while the best transition state leading to minor enantiomer involves the equatorial model. The high enantioselectivity observed with only the bulkiest catalyst arises from the steric interactions between the substrates and the bulky groups on the catalyst, and the resulting necessity for distortion of the catalyst in the disfavored transition state. PMID:23298338

  11. Acidic Condensation of BODIPYs with Aldehydes: A Quick and Versatile Route to Alkenyl-BODIPYs and C(sp(3) )-Connected DYEmers.

    PubMed

    Ahrens, Johannes; Cordes, Birte; Wicht, Richard; Wolfram, Benedikt; Bröring, Martin

    2016-07-18

    The condensation of aldehydes with BODIPY (boron dipyrrin) luminophores was investigated. Formaldehyde can be used to connect two BODIPYs at each of the three pyrrolic C positions (α-, β-, and β'-positions) in a quick and highly selective manner, yielding new DYEmers (di- and oligomeric BODIPY derivatives) with varied photophysical properties. Benzaldehydes form DYEmers only at the β- and the β'-positions. For aliphatic aldehydes the DYEmer formation competes with the elimination of water from a proposed alcohol intermediate, leading to the formation of α- and β-alkenyl-BODIPYs. 2-Phenylacetaldehyde and similar precursors exclusively yield elimination products. These acid-mediated transformations are valuable alternatives to the well-established, base-promoted Knoevenagel condensation protocol that is typically employed in the preparation of BODIPYs with near infrared (NIR)-shifted absorptions. PMID:27140934

  12. MASS SPECTROMETRY OF FATTY ALDEHYDES

    PubMed Central

    Berdyshev, Evgeny V.

    2011-01-01

    Fatty aldehydes are important components of the cellular lipidome. Significant interest has been developed towards the analysis of the short chain α,β-unsaturated and hydroxylated aldehydes formed as a result of oxidation of polyunsaturated fatty acids. Multiple gas chromatography-mass spectrometry (GC/MS) and subsequently liquid chromatography-mass spectrometry (LC/MS) approaches have been developed to identify and quantify short-chain as well as long-chain fatty aldehydes. Due to the ability to non-enzymaticaly form Schiff bases with amino groups of proteins, lipids, and with DNA guanidine, free aldehydes are viewed as a marker or metric of fatty acid oxidation and not the part of intracellular signaling pathways which has significantly limited the overall attention this group of molecules have received. This review provides an overview of current GC/MS and LC/MS approaches of fatty aldehyde analysis as well as discusses technical challenges standing in the way of free fatty aldehyde quantitation. PMID:21930240

  13. Lewis base activation of Lewis acids. Vinylogous aldol addition reactions of conjugated N,O-silyl ketene acetals to aldehydes.

    PubMed

    Denmark, Scott E; Heemstra, John R

    2006-02-01

    N,O-Silyl dienyl ketene acetals derived from unsaturated morpholine amides have been developed as highly useful reagents for vinylogous aldol addition reactions. In the presence of SiCl4 and the catalytic action of chiral phosphoramide (R,R)-3, N,O-silyl dienyl ketene acetal 8 undergoes high-yielding and highly site-selective addition to a wide variety of aldehydes with excellent enantioselectivity. Of particular note is the high yields and selectivities obtained from aliphatic aldehydes. Low catalyst loadings (2-5 mol %) can be employed. The morpholine amide serves as a useful precursor for further synthetic manipulation. PMID:16433495

  14. Influence of Aerosol Acidity on the Chemical Composition of Secondary Organic Aerosol from β-caryophyllene

    NASA Astrophysics Data System (ADS)

    Chan, M.; Surratt, J. D.; Chan, A. W.; Schlling, K.; Offenberg, J. H.; Lewandowski, M.; Edney, E.; Kleindienst, T. E.; Jaoui, M.; Edgerton, E. S.; Tanner, R. L.; Shaw, S. L.; Zheng, M.; Knipping, E. M.; Seinfeld, J.

    2011-12-01

    The secondary organic aerosol (SOA) yield of β-caryophyllene photooxidation is enhanced by aerosol acidity. In the present study, the influence of aerosol acidity on the chemical composition of β-caryophyllene SOA is investigated using ultra performance liquid chromatography/electrospray ionization-time-of-flight mass spectrometry (UPLC/ESI- TOFMS). A number of first- , second- and higher-generation gas-phase products having carbonyl and carboxylic acid functional groups are detected in the particle phase. Particle-phase reaction products formed via hydration and organosulfate formation processes are also detected. Increased acidity leads to different effects on the abundance of individual products; significantly, abundances of organosulfates are correlated with aerosol acidity. The increase of certain particle-phase reaction products with increased acidity provides chemical evidence to support the acid-enhanced SOA yields. Based on the agreement between the chromatographic retention times and accurate mass measurements of chamber and field samples, three β-caryophyllene products (i.e., β-nocaryophyllon aldehyde, β-hydroxynocaryophyllon aldehyde, and β-dihydroxynocaryophyllon aldehyde) are suggested as chemical tracers for β-caryophyllene SOA. These compounds are detected in both day and night ambient samples collected in downtown Atlanta, GA and rural Yorkville, GA during the 2008 August Mini-Intensive Gas and Aerosol Study (AMIGAS).

  15. Influence of aerosol acidity on the chemical composition of secondary organic aerosol from β-caryophyllene

    NASA Astrophysics Data System (ADS)

    Chan, M. N.; Surratt, J. D.; Chan, A. W. H.; Schilling, K.; Offenberg, J. H.; Lewandowski, M.; Edney, E. O.; Kleindienst, T. E.; Jaoui, M.; Edgerton, E. S.; Tanner, R. L.; Shaw, S. L.; Zheng, M.; Knipping, E. M.; Seinfeld, J. H.

    2011-02-01

    The secondary organic aerosol (SOA) yield of β-caryophyllene photooxidation is enhanced by aerosol acidity. In the present study, the influence of aerosol acidity on the chemical composition of β-caryophyllene SOA is investigated using ultra performance liquid chromatography/electrospray ionization-time-of-flight mass spectrometry (UPLC/ESI-TOFMS). A number of first-, second- and higher-generation gas-phase products having carbonyl and carboxylic acid functional groups are detected in the particle phase. Particle-phase reaction products formed via hydration and organosulfate formation processes are also detected. Increased acidity leads to different effects on the abundance of individual products; significantly, abundances of organosulfates are correlated with aerosol acidity. To our knowledge, this is the first detection of organosulfates and nitrated organosulfates derived from a sesquiterpene. The increase of certain particle-phase reaction products with increased acidity provides chemical evidence to support the acid-enhanced SOA yields. Based on the agreement between the chromatographic retention times and accurate mass measurements of chamber and field samples, three β-caryophyllene products (i.e., β-nocaryophyllon aldehyde, β-hydroxynocaryophyllon aldehyde, and β-dihydroxynocaryophyllon aldehyde) are suggested as chemical tracers for β-caryophyllene SOA. These compounds are detected in both day and night ambient samples collected in downtown Atlanta, GA and rural Yorkville, GA during the 2008 August Mini-Intensive Gas and Aerosol Study (AMIGAS).

  16. Influence of aerosol acidity on the chemical composition of Secondary Organic Aerosol from β-caryophyllene

    NASA Astrophysics Data System (ADS)

    Chan, M. N.; Surratt, J. D.; Chan, A. W. H.; Schilling, K.; Offenberg, J. H.; Lewandowski, M.; Edney, E. O.; Kleindienst, T. E.; Jaoui, M.; Edgerton, E. S.; Tanner, R. L.; Shaw, S. L.; Zheng, M.; Knipping, E. M.; Seinfeld, J. H.

    2010-11-01

    The secondary organic aerosol (SOA) yield of β-caryophyllene photooxidation is enhanced by aerosol acidity. In the present study, the influence of aerosol acidity on the chemical composition of β-caryophyllene SOA is investigated using ultra performance liquid chromatography/electrospray ionization-time-of-flight mass spectrometry (UPLC/ESI-TOFMS). A number of first-, second- and higher-generation gas-phase products having carbonyl and carboxylic acid functional groups are detected in the particle phase. Particle-phase reaction products formed via hydration and organosulfate formation processes are also detected. Increase of acidity leads to different effects on the abundance of individual products; significantly, abundances of organosulfates are correlated with aerosol acidity. To our knowledge, this is the first detection of organosulfates and nitrated organosulfates derived from a sesquiterpene. The increase of certain particle-phase reaction products with increased acidity provides chemical evidence to support the acid-enhanced SOA yields. Based on the agreement between the chromatographic retention times and accurate mass measurements of chamber and field samples, three β-caryophyllene products (i.e., β-nocaryophyllon aldehyde, β-hydroxynocaryophyllon aldehyde, and β-dihydroxynocaryophyllon aldehyde) are identified as chemical tracers for β-caryophyllene SOA. These compounds are detected in both day and night ambient samples collected in downtown Atlanta, GA and rural Yorkville, GA during the 2008 August Mini-Intensive Gas and Aerosol Study (AMIGAS).

  17. CUTICULAR LIPIDS OF THE STORED FOOD PEST, LIPOSCELIS BOSTRYCHOPHILA BADONNEL (PSOCOPTERA: LIPOSCELIDIDAE): HYDROCARBONS, ALDEHYDES, FATTY ACIDS AND FATTY ACID AMIDES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The booklouse, Liposcelis bostrychophila, has increasingly become a common pest of stored food products worldwide. We report here the cuticular hydrocarbon composition of this pest (the first report of the hydrocarbons of any member of the Order Psocoptera) and the first report of fatty acid amides...

  18. Lewis base activation of Lewis acids. Catalytic enantioselective addition of silyl enol ethers of achiral methyl ketones to aldehydes.

    PubMed

    Denmark, Scott E; Heemstra, John R

    2003-06-26

    A highly enantioselective addition of silyl enol ethers derived from simple methyl ketones is described. The catalyst system of silicon tetrachloride activated by a chiral bisphosphoramide (R,R)-7 effectively promotes the addition of a variety of unsubstituted silyl enol ethers to aromatic, olefinic, and heteroaromatic aldehydes in excellent yield. [reaction: see text] PMID:12816434

  19. Synthesis of densely substituted 1,3-butadienes through acid-catalyzed alkenylations of α-oxoketene dithioacetals with aldehydes.

    PubMed

    Liu, Changhui; Gu, Yanlong

    2014-10-17

    Aldehydes were proved to be viable reagents for implementing alkenylation of α-oxoketene dithioacetals. AlCl3 was found to be the best catalyst. The established reaction opened an avenue to access densely substituted 1,3-butadiene derivatives. The obtained product bears multiple reactive sites that can be converted into various valuable molecules. PMID:25247719

  20. Alcohol, Aldehydes, Adducts and Airways.

    PubMed

    Sapkota, Muna; Wyatt, Todd A

    2015-01-01

    Drinking alcohol and smoking cigarettes results in the formation of reactive aldehydes in the lung, which are capable of forming adducts with several proteins and DNA. Acetaldehyde and malondialdehyde are the major aldehydes generated in high levels in the lung of subjects with alcohol use disorder who smoke cigarettes. In addition to the above aldehydes, several other aldehydes like 4-hydroxynonenal, formaldehyde and acrolein are also detected in the lung due to exposure to toxic gases, vapors and chemicals. These aldehydes react with nucleophilic targets in cells such as DNA, lipids and proteins to form both stable and unstable adducts. This adduction may disturb cellular functions as well as damage proteins, nucleic acids and lipids. Among several adducts formed in the lung, malondialdehyde DNA (MDA-DNA) adduct and hybrid malondialdehyde-acetaldehyde (MAA) protein adducts have been shown to initiate several pathological conditions in the lung. MDA-DNA adducts are pre-mutagenic in mammalian cells and induce frame shift and base-pair substitution mutations, whereas MAA protein adducts have been shown to induce inflammation and inhibit wound healing. This review provides an insight into different reactive aldehyde adducts and their role in the pathogenesis of lung disease. PMID:26556381

  1. Alcohol, Aldehydes, Adducts and Airways

    PubMed Central

    Sapkota, Muna; Wyatt, Todd A.

    2015-01-01

    Drinking alcohol and smoking cigarettes results in the formation of reactive aldehydes in the lung, which are capable of forming adducts with several proteins and DNA. Acetaldehyde and malondialdehyde are the major aldehydes generated in high levels in the lung of subjects with alcohol use disorder who smoke cigarettes. In addition to the above aldehydes, several other aldehydes like 4-hydroxynonenal, formaldehyde and acrolein are also detected in the lung due to exposure to toxic gases, vapors and chemicals. These aldehydes react with nucleophilic targets in cells such as DNA, lipids and proteins to form both stable and unstable adducts. This adduction may disturb cellular functions as well as damage proteins, nucleic acids and lipids. Among several adducts formed in the lung, malondialdehyde DNA (MDA-DNA) adduct and hybrid malondialdehyde-acetaldehyde (MAA) protein adducts have been shown to initiate several pathological conditions in the lung. MDA-DNA adducts are pre-mutagenic in mammalian cells and induce frame shift and base-pair substitution mutations, whereas MAA protein adducts have been shown to induce inflammation and inhibit wound healing. This review provides an insight into different reactive aldehyde adducts and their role in the pathogenesis of lung disease. PMID:26556381

  2. Microsphere coated substrate containing reactive aldehyde groups

    NASA Technical Reports Server (NTRS)

    Rembaum, Alan (Inventor); Yen, Richard C. K. (Inventor)

    1984-01-01

    A synthetic organic resin is coated with a continuous layer of contiguous, tangential, individual microspheres having a uniform diameter preferably between 100 Angstroms and 2000 Angstroms. The microspheres are an addition polymerized polymer of an unsaturated aldehyde containing 4 to 20 carbon atoms and are covalently bonded to the substrate by means of high energy radiation grafting. The microspheres contain reactive aldehyde groups and can form conjugates with proteins such as enzymes or other aldehyde reactive materials.

  3. Acid-mediated coupling of γ-hydroxybutenolides and aldehydes: Synthesis of a new class of spirocyclic ketal-lactones

    PubMed Central

    Munoz, Alberto; Murelli, Ryan P.

    2012-01-01

    In the presence of trimethylsilyl trifluoromethanesulfonate (TMSOTf), γ-methyl-γ-hydroxybutenolide reacts with aromatic aldehydes to generate a new class of stereochemically rich spirocyclic ketal-lactones in good yields and with excellent stereoselectivities. We believe that this process takes place through the in situ generation of protoanemonin followed by a Prins reaction. Herein, we describe this discovery, along with substrate scope and preliminary mechanistic studies. PMID:23335822

  4. Control of aldehyde synthesis in the luminous bacterium Beneckea harveyi.

    PubMed Central

    Ulitzur, S; Hastings, J W

    1979-01-01

    Some of the Beneckea harveyi dim aldehyde mutants, all of which emit light upon addition of exogenous long-chain aldehyde, also emit light when myristic acid is added. Analysis of these myristic acid-responsive mutants indicates that they are blocked before fatty acid formation, whereas another class of mutants, which respond only to aldehyde, appear to be defective in the enzyme(s) involved in the conversion of acid to aldehyde. Evidence is presented that this activity, designated myristic acid reductase, is coinduced with luciferase and is involved in the recycling of acid produced in the luciferase reaction, with specificity for the C14 compounds. PMID:311359

  5. A study of interstellar aldehydes and enols as tracers of a cosmic ray-driven nonequilibrium synthesis of complex organic molecules.

    PubMed

    Abplanalp, Matthew J; Gozem, Samer; Krylov, Anna I; Shingledecker, Christopher N; Herbst, Eric; Kaiser, Ralf I

    2016-07-12

    Complex organic molecules such as sugars and amides are ubiquitous in star- and planet-forming regions, but their formation mechanisms have remained largely elusive until now. Here we show in a combined experimental, computational, and astrochemical modeling study that interstellar aldehydes and enols like acetaldehyde (CH3CHO) and vinyl alcohol (C2H3OH) act as key tracers of a cosmic-ray-driven nonequilibrium chemistry leading to complex organics even deep within low-temperature interstellar ices at 10 K. Our findings challenge conventional wisdom and define a hitherto poorly characterized reaction class forming complex organic molecules inside interstellar ices before their sublimation in star-forming regions such as SgrB2(N). These processes are of vital importance in initiating a chain of chemical reactions leading eventually to the molecular precursors of biorelevant molecules as planets form in their interstellar nurseries. PMID:27382172

  6. Aldehyde-stabilized cryopreservation.

    PubMed

    McIntyre, Robert L; Fahy, Gregory M

    2015-12-01

    We describe here a new cryobiological and neurobiological technique, aldehyde-stabilized cryopreservation (ASC), which demonstrates the relevance and utility of advanced cryopreservation science for the neurobiological research community. ASC is a new brain-banking technique designed to facilitate neuroanatomic research such as connectomics research, and has the unique ability to combine stable long term ice-free sample storage with excellent anatomical resolution. To demonstrate the feasibility of ASC, we perfuse-fixed rabbit and pig brains with a glutaraldehyde-based fixative, then slowly perfused increasing concentrations of ethylene glycol over several hours in a manner similar to techniques used for whole organ cryopreservation. Once 65% w/v ethylene glycol was reached, we vitrified brains at -135 °C for indefinite long-term storage. Vitrified brains were rewarmed and the cryoprotectant removed either by perfusion or gradual diffusion from brain slices. We evaluated ASC-processed brains by electron microscopy of multiple regions across the whole brain and by Focused Ion Beam Milling and Scanning Electron Microscopy (FIB-SEM) imaging of selected brain volumes. Preservation was uniformly excellent: processes were easily traceable and synapses were crisp in both species. Aldehyde-stabilized cryopreservation has many advantages over other brain-banking techniques: chemicals are delivered via perfusion, which enables easy scaling to brains of any size; vitrification ensures that the ultrastructure of the brain will not degrade even over very long storage times; and the cryoprotectant can be removed, yielding a perfusable aldehyde-preserved brain which is suitable for a wide variety of brain assays. PMID:26408851

  7. An organocatalytic Michael-cyclization cascade of 4-oxa-α,β-unsaturated carboxylic acids with aldehydes: facile synthesis of chiral γ-lactols and trisubstituted γ-lactones.

    PubMed

    Lin, Jun-Bing; Xu, Shi-Ming; Xie, Ji-Kang; Li, Hong-Yu; Xu, Peng-Fei

    2015-02-28

    An organocatalytic Michael-cyclization cascade of aldehydes with 4-oxa-α,β-unsaturated carboxylic acids has been developed, giving functionalized γ-lactols with high yields and enantioselectivities. The products could be easily transformed into complex trisubstituted γ-lactones and γ-lactams. PMID:25633800

  8. Characterization of the Aldehydes and Their Transformations Induced by UV Irradiation and Air Exposure of White Guanxi Honey Pummelo (Citrus Grandis (L.) Osbeck) Essential Oil.

    PubMed

    Li, Li Jun; Hong, Peng; Chen, Feng; Sun, Hao; Yang, Yuan Fan; Yu, Xiang; Huang, Gao Ling; Wu, Li Ming; Ni, Hui

    2016-06-22

    Aldehydes are key aroma contributors of citrus essential oils. White Guanxi honey pummelo essential oil (WPEO) was investigated in its aldehyde constituents and their transformations induced by UV irradiation and air exposure by GC-MS, GC-O, and sensory evaluation. Nine aldehydes, i.e., octanal, nonanal, citronellal, decanal, trans-citral, cis-citral, perilla aldehyde, dodecanal, and dodecenal, were detected in WPEO. After treatment, the content of citronellal increased, but the concentrations of other aldehydes decreased. The aliphatic aldehydes were transformed to organic acids. Citral was transformed to neric acid, geranic acid, and cyclocitral. Aldehyde transformation caused a remarkable decrease in the minty, herbaceous, and lemon notes of WPEO. In fresh WPEO, β-myrcene, d-limonene, octanal, decanal, cis-citral, trans-citral, and dodecenal had the highest odor dilution folds. After the treatment, the dilution folds of decanal, cis-citral, trans-citral, and dodecenal decreased dramatically. This result provides information for the production and storage of aldehyde-containing products. PMID:27226192

  9. Organic Acid Production by Filamentous Fungi

    SciTech Connect

    Magnuson, Jon K.; Lasure, Linda L.

    2004-05-03

    Many of the commercial production processes for organic acids are excellent examples of fungal biotechnology. However, unlike penicillin, the organic acids have had a less visible impact on human well-being. Indeed, organic acid fermentations are often not even identified as fungal bioprocesses, having been overshadowed by the successful deployment of the β-lactam processes. Yet, in terms of productivity, fungal organic acid processes may be the best examples of all. For example, commercial processes using Aspergillus niger in aerated stirred-tank-reactors can convert glucose to citric acid with greater than 80% efficiency and at final concentrations in hundreds of grams per liter. Surprisingly, this phenomenal productivity has been the object of relatively few research programs. Perhaps a greater understanding of this extraordinary capacity of filamentous fungi to produce organic acids in high concentrations will allow greater exploitation of these organisms via application of new knowledge in this era of genomics-based biotechnology. In this chapter, we will explore the biochemistry and modern genetic aspects of the current and potential commercial processes for making organic acids. The organisms involved, with a few exceptions, are filamentous fungi, and this review is limited to that group. Although yeasts including Saccharomyces cerevisiae, species of Rhodotorula, Pichia, and Hansenula are important organisms in fungal biotechnology, they have not been significant for commercial organic acid production, with one exception. The yeast, Yarrowia lipolytica, and related yeast species, may be in use commercially to produce citric acid (Lopez-Garcia, 2002). Furthermore, in the near future engineered yeasts may provide new commercial processes to make lactic acid (Porro, Bianchi, Ranzi, Frontali, Vai, Winkler, & Alberghina, 2002). This chapter is divided into two parts. The first contains a review of the commercial aspects of current and potential large

  10. Simultaneous Determination and Pharmacokinetic Study of Protocatechuic Aldehyde and Its Major Active Metabolite Protocatechuic Acid in Rat Plasma by Liquid Chromatography-Tandem Mass Spectrometry.

    PubMed

    Wang, Xiangyang; Yan, Kaijing; Ma, Xiaohui; Li, Wei; Chu, Yang; Guo, Jiahua; Li, Shuming; Zhou, Shuiping; Zhu, Yonghong; Liu, Changxiao

    2016-05-01

    A very simple and selective high-performance liquid chromatography electrospray ionization tandem mass spectrometry (LC-MS-MS) method was developed for simultaneous determination and pharmacokinetic study of protocatechuic aldehyde (PAL) and its active metabolite protocatechuic acid (PCA). The method involves a simple liquid-liquid extraction with ethyl acetate. The separation was performed on a Hypersil GOLD C18column (2.1 × 150 mm, 3.0 µm; particle, Thermo, USA) with isocratic elution using a mobile phase consisted of methanol and water (containing 0.1% formic acid) at a flow rate of 0.2 mL/min. The detection of target compounds was done by using low-energy collision dissociation tandem mass spectrometry (CID-MS-MS) using the selective reaction monitoring scan mode. The method was linear for all analytes over the investigated range for all correlation coefficients greater than 0.9950. The lower limits of quantification were 2.0 ng/mL for PAL and PCA. The intra- and interday precisions (relative standard deviation, RSD %) were <6.84 and 5.54%, and the accuracy (relative error, RE %) was between -2.85 and 0.74% (n= 6). The developed method was applied to study the pharmacokinetics of PAL and its major active metabolite PCA in rat plasma after oral and intravenous administration of PAL. PMID:26969682

  11. Aldehyde oxidase 1 is highly abundant in hepatic steatosis and is downregulated by adiponectin and fenofibric acid in hepatocytes in vitro

    SciTech Connect

    Neumeier, Markus; Weigert, Johanna; Schaeffler, Andreas; Weiss, Thomas S.; Schmidl, Christian; Buettner, Roland; Bollheimer, Cornelius; Aslanidis, Charalampos; Schoelmerich, Juergen; Buechler, Christa . E-mail: christa.buechler@klinik.uni-regensburg.de

    2006-11-24

    Adiponectin protects the liver from steatosis caused by obesity or alcohol and therefore the influence of adiponectin on human hepatocytes was analyzed. GeneChip experiments indicated that recombinant adiponectin downregulates aldehyde oxidase 1 (AOX1) expression and this was confirmed by real-time RT-PCR and immunoblot. AOX1 is a xenobiotic metabolizing protein and produces reactive oxygen species (ROS), that promote cell damage and fibrogenesis. Adiponectin and fenofibric acid activate peroxisome proliferator-activated receptor-{alpha} (PPAR-{alpha}) and both suppress AOX1 protein and this is blocked by the PPAR-{alpha} antagonist RU486. Obesity is associated with low adiponectin, reduced hepatic PPAR-{alpha} activity and fatty liver, and AOX1 was found induced in the liver of rats on a high-fat diet when compared to controls. Free fatty acids and leptin, that are elevated in obesity, failed to upregulate AOX1 in vitro. The current data indicate that adiponectin reduces AOX1 by activating PPAR-{alpha} whereas fatty liver disease is associated with elevated hepatic AOX1. High AOX1 may be associated with higher ROS well described to induce fibrogenesis in liver tissue but may also influence drug metabolism and activity.

  12. Betaine aldehyde dehydrogenase in sorghum.

    PubMed Central

    Wood, A J; Saneoka, H; Rhodes, D; Joly, R J; Goldsbrough, P B

    1996-01-01

    The ability to synthesize and accumulate glycine betaine is wide-spread among angiosperms and is thought to contribute to salt and drought tolerance. In plants glycine betaine is synthesized by the two-step oxidation of choline via the intermediate betaine aldehyde, catalyzed by choline monooxygenase and betaine aldehyde dehydrogenase (BADH). Two sorghum (Sorghum bicolor) cDNA clones, BADH1 and BADH15, putatively encoding betaine aldehyde dehydrogenase were isolated and characterized. BADH1 is a truncated cDNA of 1391 bp. BADH15 is a full-length cDNA clone, 1812 bp in length, predicted to encode a protein of 53.6 kD. The predicted amino acid sequences of BADH1 and BADH15 share significant homology with other plant BADHs. The effects of water deficit on BADH mRNA expression, leaf water relations, and glycine betaine accumulation were investigated in leaves of preflowering sorghum plants. BADH1 and BADH15 mRNA were both induced by water deficit and their expression coincided with the observed glycine betaine accumulation. During the course of 17 d, the leaf water potential in stressed sorghum plants reached -2.3 MPa. In response to water deficit, glycine betaine levels increased 26-fold and proline levels increased 108-fold. In severely stressed plants, proline accounted for > 60% of the total free amino acid pool. Accumulation of these compatible solutes significantly contributed to osmotic potential and allowed a maximal osmotic adjustment of 0.405 MPa. PMID:8934627

  13. Synthesis of 5'-Aldehyde Oligonucleotide.

    PubMed

    Lartia, Rémy

    2016-01-01

    Synthesis of oligonucleotide ending with an aldehyde functional group at their 5'-end (5'-AON) is possible for both DNA (5'-AODN) and RNA (5'-AORN) series irrespectively of the nature of the last nucleobase. The 5'-alcohol of on-support ODN is mildly oxidized under Moffat conditions. Transient protection of the resulting aldehyde by N,N'-diphenylethylenediamine derivatives allows cleavage, deprotection, and RP-HPLC purification of the protected 5'-AON. Finally, 5'-AON is deprotected by usual acetic acid treatment. In the aggregates, 5'-AON can be now synthesized and purified as routinely as non-modified ODNs, following procedures similar to the well-known "DMT-On" strategy. PMID:26967469

  14. Organic acid-tolerant microorganisms and uses thereof for producing organic acids

    DOEpatents

    Pfleger, Brian Frederick; Begemann, Matthew Brett

    2014-05-06

    Organic acid-tolerant microorganisms and methods of using same. The organic acid-tolerant microorganisms comprise modifications that reduce or ablate AcsA activity or AcsA homolog activity. The modifications increase tolerance of the microorganisms to such organic acids as 3-hydroxypropionic acid (3HP), acrylic acid, and propionic acid. Further modifications to the microorganisms such as increasing expression of malonyl-CoA reductase and/or acetyl-CoA carboxylase provide or increase the ability of the microorganisms to produce 3HP. Methods of generating an organic acid with the modified microorganisms are provided. Methods of using acsA or homologs thereof as counter-selectable markers include replacing acsA or homologs thereof in cells with genes of interest and selecting for the cells comprising the genes of interest with amounts of organic acids effective to inhibit growth of cells harboring acsA or the homologs.

  15. Testing of organic acids in engine coolants

    SciTech Connect

    Weir, T.W.

    1999-08-01

    The effectiveness of 30 organic acids as inhibitors in engine coolants is reported. Tests include glassware corrosion of coupled and uncoupled metals. FORD galvanostatic and cyclic polarization electrochemistry for aluminum pitting, and reserve alkalinity (RA) measurements. Details of each test are discussed as well as some general conclusions. For example, benzoic acid inhibits coupled metals well but is ineffective on cast iron when uncoupled. In benzoic acid inhibits coupled metals well but is ineffective on cast iron when uncoupled. In general, the organic acids provide little RA when titrated to a pH of 5.5, titration to a pH of 4.5 can result in precipitation of the acid. Trends with respect to acid chain length are reported also.

  16. Nanoparticles modified with multiple organic acids

    NASA Technical Reports Server (NTRS)

    Cook, Ronald Lee (Inventor); Luebben, Silvia DeVito (Inventor); Myers, Andrew William (Inventor); Smith, Bryan Matthew (Inventor); Elliott, Brian John (Inventor); Kreutzer, Cory (Inventor); Wilson, Carolina (Inventor); Meiser, Manfred (Inventor)

    2007-01-01

    Surface-modified nanoparticles of boehmite, and methods for preparing the same. Aluminum oxyhydroxide nanoparticles are surface modified by reaction with selected amounts of organic acids. In particular, the nanoparticle surface is modified by reactions with two or more different carboxylic acids, at least one of which is an organic carboxylic acid. The product is a surface modified boehmite nanoparticle that has an inorganic aluminum oxyhydroxide core, or part aluminum oxyhydroxide core and a surface-bonded organic shell. Organic carboxylic acids of this invention contain at least one carboxylic acid group and one carbon-hydrogen bond. One embodiment of this invention provides boehmite nanoparticles that have been surface modified with two or more acids one of which additional carries at least one reactive functional group. Another embodiment of this invention provides boehmite nanoparticles that have been surface modified with multiple acids one of which has molecular weight or average molecular weight greater than or equal to 500 Daltons. Yet, another embodiment of this invention provides boehmite nanoparticles that are surface modified with two or more acids one of which is hydrophobic in nature and has solubility in water of less than 15 by weight. The products of the methods of this invention have specific useful properties when used in mixture with liquids, as filler in solids, or as stand-alone entities.

  17. Nanoparticles modified with multiple organic acids

    DOEpatents

    Cook, Ronald Lee; Luebben, Silvia DeVito; Myers, Andrew William; Smith, Bryan Matthew; Elliott, Brian John; Kreutzer, Cory; Wilson, Carolina; Meiser, Manfred

    2007-07-17

    Surface-modified nanoparticles of boehmite, and methods for preparing the same. Aluminum oxyhydroxide nanoparticles are surface modified by reaction with selected amounts of organic acids. In particular, the nanoparticle surface is modified by reactions with two or more different carboxylic acids, at least one of which is an organic carboxylic acid. The product is a surface modified boehmite nanoparticle that has an inorganic aluminum oxyhydroxide core, or part aluminum oxyhydroxide core and a surface-bonded organic shell. Organic carboxylic acids of this invention contain at least one carboxylic acid group and one carbon-hydrogen bond. One embodiment of this invention provides boehmite nanoparticles that have been surface modified with two or more acids one of which additional carries at least one reactive functional group. Another embodiment of this invention provides boehmite nanoparticles that have been surface modified with multiple acids one of which has molecular weight or average molecular weight greater than or equal to 500 Daltons. Yet, another embodiment of this invention provides boehmite nanoparticles that are surface modified with two or more acids one of which is hydrophobic in nature and has solubility in water of less than 15 by weight. The products of the methods of this invention have specific useful properties when used in mixture with liquids, as filler in solids, or as stand-alone entities.

  18. Oxidative versus Non-oxidative Decarboxylation of Amino Acids: Conditions for the Preferential Formation of Either Strecker Aldehydes or Amines in Amino Acid/Lipid-Derived Reactive Carbonyl Model Systems.

    PubMed

    Zamora, Rosario; León, M Mercedes; Hidalgo, Francisco J

    2015-09-16

    Comparative formation of both 2-phenylethylamine and phenylacetaldehyde as a consequence of phenylalanine degradation by carbonyl compounds was studied in an attempt to understand if the amine/aldehyde ratio can be changed as a function of reaction conditions. The assayed carbonyl compounds were selected because of the presence in the chain of both electron-donating and electron-withdrawing groups and included alkenals, alkadienals, epoxyalkenals, oxoalkenals, and hydroxyalkenals as well as lipid hydroperoxides. The obtained results showed that the 2-phenylethylamine/phenylacetaldehyde ratio depended upon both the carbonyls and the reaction conditions. Thus, it can be increased using electron-donating groups in the chain of the carbonyl compound, small amounts of carbonyl compound, low oxygen content, increasing the pH, or increasing the temperature at pH 6. Opposed conditions (use of electron-withdrawing groups in the chain of the carbonyl compound, large amounts of carbonyl compound, high oxygen contents, low pH values, and increasing temperatures at low pH values) would decrease the 2-phenylethylamine/phenylacetaldehyde ratio, and the formation of aldehydes over amines in amino acid degradations would be favored. PMID:26189462

  19. Multiple aldehyde reductases of human brain.

    PubMed

    Hoffman, P L; Wermuth, B; von Wartburg, J P

    1980-01-01

    Human brain contains four forms of aldehyde reducing enzymes. One major activity, designated AR3, has properties indicating its identity with the NADPH-dependent aldehyde reductase, EC 1.1.1.2. The other major form of human brain enzyme, AR1, which is also NADPH-dependent, reduces both aldehyde and ketone-containing substrates, including vitamin K3 (menadione) and daunorubicin, a cancer chemotherapeutic agent. This enzyme is very sensitive to inhibition by the flavonoids quercitrin and quercetine, and may be analogous to a daunorubicin reductase previously described in liver of other species. One minor form of human brain aldehyde reductase, AR2, demonstrates substrate specificity and inhibitor sensitivity which suggest its similarity to aldose reductases found in lens and other tissues of many species. This enzyme, which can also use NADH as cofactor to some extent, is the most active in reducing the aldehyde derivatives of the biogenic amines. The fourth human brain enzyme ("SSA reductase") differs from the other forms in its ability to use NADH as well as or better than NADPH as cofactor, and in its molecular weight, which is nearly twice that of the other forms. It is quite specific for succinic semialdehyde (SSA) as substrate, and was found to be significantly inhibited only by quercetine and quercitrin. AR3 can also reduce SSA, and both enzymes may contribute to the production of gamma-hydroxybutyric acid in vivo. These results indicate that the human brain aldehyde reductases can play relatively specific physiologic roles. PMID:7424738

  20. Measurements of Oxygenated Organic Chemicals In the Pacific Troposphere During TRACE-P: Higher Aldehydes (less than C(sub 1)), Their Sources, and Potential Role In Atmospheric Oxidation

    NASA Technical Reports Server (NTRS)

    Singh, Hanwant B.; Salas, L.; Herlth, D.; Viezee, W.; Fried, A.; Jackob, D.; Blake, D.; Heikes, B.; Talbot, R.; Sachse, G.; Hipskind, R. Stephen (Technical Monitor)

    2002-01-01

    Airborne measurements of a large number of oxygenated organics were carried out in the Pacific troposphere (to 12 km) in the Spring of 2001 (Feb. 24-April 10). Specifically these measurements included acetaldehyde, propanaldehyde, acetone, methylethyl ketone, methanol, ethanol, PAM and organic nitrates. Independent measurements of formaldehyde, peroxides, and tracers were also available. Highly polluted as well as pristine air masses were sampled. Oxygenated organics were abundant in the clean In troposphere and were greatly enhanced in the outflow regions from Asia. Extremely high concentrations of aldehydes could be measured in the troposphere. It is not possible to explain the large abundances of aldehydes in the background troposphere without invoking significant oceanic sources. A strong correlation between the observed mixing ratios of formaldehyde and acetaldehyde is present. We infer that higher aldehydes (such as acetaldehyde and propanaldehyde) may provide a large source of formaldehyde and sequester Cox throughout the troposphere. The atmospheric behavior of acetone, methylethyl ketone, and methanol is generally indicative of their common terrestrial sources with a Image contribution from biomass/biofuel burning. A vast body of data has been collected and it is being analyzed both statistically and with the help of models to better understand the role that oxygenated organics play in the atmosphere and to unravel their sources and sinks. These results will be presented.

  1. Covalent immobilization of Candida rugosa lipase on aldehyde functionalized hydrophobic support and the application for synthesis of oleic acid ester.

    PubMed

    Temoçin, Zülfikar

    2013-01-01

    This study focuses on Candida rugosa lipase (CRL) immobilization by covalent attachment on poly(ethylene terephthalate)-grafted glycidyl methacrylate (PET-g-GMA) fiber. The immobilization yielded a protein loading of 2.38 mg g(-1) of PET-g-GMA fiber. The performances of the immobilized and free CRLs were evaluated with regard to hydrolysis of olive oil and esterification of oleic acid. The optimum activity pH of the CRL was changed by immobilization to neutral range. The maximum activity of the free and immobilized CRLs occurred at 40 and 45 °C respectively. The immobilized lipase retained 65% of its original activity at 50 °C for 2 h. It was found that the immobilized lipase stored at 4 °C retained 90% of its original activity after 35 days, whereas the free lipase stored at 4 °C retained 69% of its original activity after the same period. In the esterification experiments, the immobilized CRL could maintain a high activity at a water content range from 1.5 to 6% (v/v), while the activity of free CRL showed a clear dependence on water content and decreased rapidly at above 3% (v/v) water content. In addition, after five reuses, the esterification percent yield of the immobilized CRL slightly decreased from 29 to 27%. PMID:23574345

  2. Gas chromatography-mass spectrometry profile of urinary organic acids of Wistar rats orally treated with ozonized unsaturated triglycerides and ozonized sunflower oil.

    PubMed

    Jardines, Daniel; Correa, Teresa; Ledea, Oscar; Zamora, Zullyt; Rosado, Aristides; Molerio, Jesús

    2003-01-15

    The main products in the ozonolysis of unsaturated triglycerides or vegetable oils are peroxides, aldehydes, Criegee ozonides and carboxylic acids. Some of these compounds are present in different concentrations in the biological fluids. The aim of this work is to study, using gas chromatography-mass spectrometry (GC-MS), the organic acid excretion in urine of rats orally treated with ozonized sunflower oil (OSO), ozonized triolein or ozonized trilinolein. Oral administration of OSO to Wistar rats has produced changes in the urinary content of dicarboxylic organic acids. Among others heptanedioic (pimelic acid) and nonanedioic acids (azelaic acid) were the major increased dicarboxylic acids found. The urinary dicarboxylic acid profiles of rats which received ozonized triolein only showed an increase in heptanedioic and nonanedioic acids. However, when ozonized trilinolein is applied, the profile is similar to that obtained when OSO is administered. A biochemical mechanism is proposed to explain the formation of dicarboxylic acids from ozonated unsaturated triglycerides. PMID:12482495

  3. Newer Reagents in Preparative Organic Chemistry.

    ERIC Educational Resources Information Center

    Grundy, J.

    1990-01-01

    Outlined is the development and use of oxidants for use in elementary organic chemistry classes. Discussed is the oxidation of alcohols to carbonyl compounds, and the oxidation of primary alcohols or aldehydes to carboxylic acids. (CW)

  4. A coniferyl aldehyde dehydrogenase gene from Pseudomonas sp. strain HR199 enhances the conversion of coniferyl aldehyde by Saccharomyces cerevisiae.

    PubMed

    Adeboye, Peter Temitope; Olsson, Lisbeth; Bettiga, Maurizio

    2016-07-01

    The conversion of coniferyl aldehyde to cinnamic acids by Saccharomyces cerevisiae under aerobic growth conditions was previously observed. Bacteria such as Pseudomonas have been shown to harbor specialized enzymes for converting coniferyl aldehyde but no comparable enzymes have been identified in S. cerevisiae. CALDH from Pseudomonas was expressed in S. cerevisiae. An acetaldehyde dehydrogenase (Ald5) was also hypothesized to be actively involved in the conversion of coniferyl aldehyde under aerobic growth conditions in S. cerevisiae. In a second S. cerevisiae strain, the acetaldehyde dehydrogenase (ALD5) was deleted. A prototrophic control strain was also engineered. The engineered S. cerevisiae strains were cultivated in the presence of 1.1mM coniferyl aldehyde under aerobic condition in bioreactors. The results confirmed that expression of CALDH increased endogenous conversion of coniferyl aldehyde in S. cerevisiae and ALD5 is actively involved with the conversion of coniferyl aldehyde in S. cerevisiae. PMID:27070284

  5. Microbial Engineering for Aldehyde Synthesis

    PubMed Central

    Kunjapur, Aditya M.

    2015-01-01

    Aldehydes are a class of chemicals with many industrial uses. Several aldehydes are responsible for flavors and fragrances present in plants, but aldehydes are not known to accumulate in most natural microorganisms. In many cases, microbial production of aldehydes presents an attractive alternative to extraction from plants or chemical synthesis. During the past 2 decades, a variety of aldehyde biosynthetic enzymes have undergone detailed characterization. Although metabolic pathways that result in alcohol synthesis via aldehyde intermediates were long known, only recent investigations in model microbes such as Escherichia coli have succeeded in minimizing the rapid endogenous conversion of aldehydes into their corresponding alcohols. Such efforts have provided a foundation for microbial aldehyde synthesis and broader utilization of aldehydes as intermediates for other synthetically challenging biochemical classes. However, aldehyde toxicity imposes a practical limit on achievable aldehyde titers and remains an issue of academic and commercial interest. In this minireview, we summarize published efforts of microbial engineering for aldehyde synthesis, with an emphasis on de novo synthesis, engineered aldehyde accumulation in E. coli, and the challenge of aldehyde toxicity. PMID:25576610

  6. Heterogeneous Chemistry of Carbonyls and Alcohols With Sulfuric Acid: Implications for Secondary Organic Aerosol Formation

    NASA Astrophysics Data System (ADS)

    Zhao, J.; Levitt, N.; Zhang, R.

    2006-12-01

    Recent environmental chamber studies have suggested that acid-catalyzed particle-phase reactions of organic carbonyls lead to multifold increases in secondary organic aerosol (SOA) mass and acid-catalyzed reactions between alcohols and aldehydes in the condensed phase lead to the formation of hemiacetals and acetals, also enhancing secondary organic aerosol growth. The kinetics and mechanism of the heterogeneous chemistry of carbonyls and alcohols with sulfuric acid, however, remain largely uncertain. In this talk, we present measurements of heterogeneous uptake of several carbonyls and alcohols on liquid H2SO4 in a wide range of acid concentrations and temperatures. The results indicate that uptake of larger carbonyls is explained by aldol condensation. For small dicarbonyls, heterogeneous reactions are shown to decrease with acidity and involve negligible formation of sulfate esters. Hydration and polymerization likely explain the measured uptake of such small dicarbonyls on H2SO4 and the measurements do not support an acid- catalyzed uptake. Atmospheric implications from our findings will be discussed.

  7. Mechanism of Alcohol-Water Dehydrogenative Coupling into Carboxylic Acid Using Milstein's Catalyst: A Detailed Investigation of the Outer-Sphere PES in the Reaction of Aldehydes with an Octahedral Ruthenium Hydroxide.

    PubMed

    Hasanayn, Faraj; Al-Assi, Lara M; Moussawi, Rasha N; Omar, Boushra Srour

    2016-08-15

    In aqueous basic media, the square-pyramidal complex [Ru(PNN)(CO)(H)] (1-Ru, where PNN is a dearomatized bipyridyl-CH-P(t)Bu2 pincer ligand) catalyzes the transformation of alcohols and water into carboxylates and H2. A previous theoretical investigation reported the following mechanism for the reaction: (i) metal-catalyzed dehydrogenation of the alcohol into an aldehyde, (ii) metal-ligand cooperation (MLC) addition of water to 1-Ru to give an octahedral ruthenium hydroxide (2-Ru-OH), (iii) concerted MLC hydration of the aldehyde by 2-Ru-OH to give separated 1-Ru and a gem-diol, and (iv) concerted MLC dehydrogenation of the gem-diol by 1-Ru into an octahedral ruthenium dihydride (2-Ru-H) and a carboxylic acid. We calculate the outer-sphere PES in the reaction between the aldehyde and 2-Ru-OH to start with a localized coupling step yielding an ion-pair minimum (7-ip-OH) in which the hydroxyl group of an α-hydroxyl-alkoxide (gem-diolate) is coordinated to the metal of a cationic square-pyramidal complex. From 7-ip-OH, we identify a route to carboxylic acid that circumvents ligand deprotonation involving (i) 1,1-rearrangement of the gem-diolate within the contact ion pair through an α-OH/O(-) slippage TS into the octahedral 2-Ru-OCH(OH)R and (ii) a second 1,1-rearrangement through an α-O(-)/H slippage TS that gives a new ion-pair minimum in which the α-hydrogen of the anion is coordinated to the metal, followed by a localized hydride-transfer TS that gives a carboxylic acid and the octahedral hydride complex (2-Ru-H). The net transformation from 2-Ru-OH and the aldehyde to the carboxylic acid and 2-Ru-H can be viewed as a H/OH metathesis in which a hydride and a hydroxide are exchanged between the acyl group of the aldehyde and the metal center of 2-Ru-OH. The MLC mechanism gives the same metathesis products through the intermediacy of a gem-diol. When the SMD solvent continuum model is applied during geometry optimization with water as the solvent, the Gibbs free

  8. Photoenhanced anaerobic digestion of organic acids

    DOEpatents

    Weaver, Paul F.

    1990-01-01

    A process is described for rapid conversion of organic acids and alcohols anaerobic digesters into hydrogen and carbon dioxide, the optimal precursor substrates for production of methane. The process includes addition of photosynthetic bacteria to the digester and exposure of the bacteria to radiant energy (e.g., solar energy). The process also increases the pH stability of the digester to prevent failure of the digester. Preferred substrates for photosynthetic bacteria are the organic acid and alcohol waste products of fermentative bacteria. In mixed culture with methanogenic bacteria or in defined co-culture with non-aceticlastic methanogenic bacteria, photosynthetic bacteria are capable of facilitating the conversion or organic acids and alcohols into methane with low levels of light energy input.

  9. Organic reactions increasing the absorption index of atmospheric sulfuric acid aerosols

    NASA Astrophysics Data System (ADS)

    Nozière, B.; Esteve, W.

    2005-02-01

    Unlike most environments present at Earth's surface atmospheric aerosols can be favorable to organic reactions. Among them, the acid-catalyzed aldol condensation of aldehydes and ketones produces light-absorbing compounds. In this work the increase of the absorption index of sulfuric acid solutions 50-96 wt. % resulting from the uptake of gas-phase acetaldehyde, acetone, and 2-butanone (methyl ethyl ketone), has been measured in the near UV and visible range. Our results indicate that the absorption index between 200 and 500 nm for stratospheric sulfuric aerosols exposed to 100 pptV of acetaldehyde (1 pptV = 10-12 v/v) would increase by four orders of magnitude over a two-year lifetime. Rough estimates based on previous radiative calculations suggest that this reaction could result in an increase of the radiative forcing of sulfate aerosols of the order of 0.01 W m-2, and that these processes are worth further investigation.

  10. Structure and function of mammalian aldehyde oxidases.

    PubMed

    Terao, Mineko; Romão, Maria João; Leimkühler, Silke; Bolis, Marco; Fratelli, Maddalena; Coelho, Catarina; Santos-Silva, Teresa; Garattini, Enrico

    2016-04-01

    Mammalian aldehyde oxidases (AOXs; EC1.2.3.1) are a group of conserved proteins belonging to the family of molybdo-flavoenzymes along with the structurally related xanthine dehydrogenase enzyme. AOXs are characterized by broad substrate specificity, oxidizing not only aromatic and aliphatic aldehydes into the corresponding carboxylic acids, but also hydroxylating a series of heteroaromatic rings. The number of AOX isoenzymes expressed in different vertebrate species is variable. The two extremes are represented by humans, which express a single enzyme (AOX1) in many organs and mice or rats which are characterized by tissue-specific expression of four isoforms (AOX1, AOX2, AOX3, and AOX4). In vertebrates each AOX isoenzyme is the product of a distinct gene consisting of 35 highly conserved exons. The extant species-specific complement of AOX isoenzymes is the result of a complex evolutionary process consisting of a first phase characterized by a series of asynchronous gene duplications and a second phase where the pseudogenization and gene deletion events prevail. In the last few years remarkable advances in the elucidation of the structural characteristics and the catalytic mechanisms of mammalian AOXs have been made thanks to the successful crystallization of human AOX1 and mouse AOX3. Much less is known about the physiological function and physiological substrates of human AOX1 and other mammalian AOX isoenzymes, although the importance of these proteins in xenobiotic metabolism is fairly well established and their relevance in drug development is increasing. This review article provides an overview and a discussion of the current knowledge on mammalian AOX. PMID:26920149

  11. Chemoenzymatic Fc Glycosylation via Engineered Aldehyde Tags

    PubMed Central

    2014-01-01

    Glycoproteins with chemically defined glycosylation sites and structures are important biopharmaceutical targets and critical tools for glycobiology. One approach toward constructing such molecules involves chemical glycosylation of aldehyde-tagged proteins. Here, we report the installation of a genetically encoded aldehyde tag at the internal glycosylation site of the crystallizable fragment (Fc) of IgG1. We replaced the natural Fc N-glycosylation sequon with a five amino-acid sequence that was efficiently converted by recombinant formylglycine generating enzyme in vitro, thereby introducing aldehyde groups for subsequent chemical elaboration. Oxime-linked glycoconjugates were synthesized by conjugating aminooxy N-acetylglucosamine to the modified Fc followed by enzymatic transfer of complex N-glycans from corresponding glycan oxazolines by an EndoS-derived glycosynthase. In this manner we generated specific Fc glycoforms without relying on natural protein glycosylation machineries. PMID:24702330

  12. Oxidation of Aromatic Aldehydes Using Oxone

    ERIC Educational Resources Information Center

    Gandhari, Rajani; Maddukuri, Padma P.; Thottumkara, Vinod K.

    2007-01-01

    The experiment demonstrating the feasibility of using water as a solvent for organic reactions which highlights the cost and environmental benefits of its use is presented. The experiment encourages students to think in terms of the reaction mechanism of the oxidation of aldehydes knowing that potassium persulfate is the active oxidant in Oxone…

  13. Aldehyde dehydrogenase inhibitors from the mushroom Clitocybe clavipes.

    PubMed

    Kawagishi, Hirokazu; Miyazawa, Toshiyuki; Kume, Hiroko; Arimoto, Yasushi; Inakuma, Takahiro

    2002-11-01

    Five fatty acid derivatives including three novel compounds were isolated from the mushroom Clitocybe clavipe. Their structures were elucidated by spectral analyses. These compounds inhibited aldehyde dehydrogenase in vitro. PMID:12444711

  14. Characterization of an Allylic/Benzyl Alcohol Dehydrogenase from Yokenella sp. Strain WZY002, an Organism Potentially Useful for the Synthesis of α,β-Unsaturated Alcohols from Allylic Aldehydes and Ketones

    PubMed Central

    Ying, Xiangxian; Wang, Yifang; Xiong, Bin; Wu, Tingting; Xie, Liping; Yu, Meilan

    2014-01-01

    A novel whole-cell biocatalyst with high allylic alcohol-oxidizing activities was screened and identified as Yokenella sp. WZY002, which chemoselectively reduced the C=O bond of allylic aldehydes/ketones to the corresponding α,β-unsaturated alcohols at 30°C and pH 8.0. The strain also had the capacity of stereoselectively reducing aromatic ketones to (S)-enantioselective alcohols. The enzyme responsible for the predominant allylic/benzyl alcohol dehydrogenase activity was purified to homogeneity and designated YsADH (alcohol dehydrogenase from Yokenella sp.), which had a calculated subunit molecular mass of 36,411 Da. The gene encoding YsADH was subsequently expressed in Escherichia coli, and the purified recombinant YsADH protein was characterized. The enzyme strictly required NADP(H) as a coenzyme and was putatively zinc dependent. The optimal pH and temperature for crotonaldehyde reduction were pH 6.5 and 65°C, whereas those for crotyl alcohol oxidation were pH 8.0 and 55°C. The enzyme showed moderate thermostability, with a half-life of 6.2 h at 55°C. It was robust in the presence of organic solvents and retained 87.5% of the initial activity after 24 h of incubation with 20% (vol/vol) dimethyl sulfoxide. The enzyme preferentially catalyzed allylic/benzyl aldehydes as the substrate in the reduction of aldehydes/ketones and yielded the highest activity of 427 U mg−1 for benzaldehyde reduction, while the alcohol oxidation reaction demonstrated the maximum activity of 79.9 U mg−1 using crotyl alcohol as the substrate. Moreover, kinetic parameters of the enzyme showed lower Km values and higher catalytic efficiency for crotonaldehyde/benzaldehyde and NADPH than for crotyl alcohol/benzyl alcohol and NADP+, suggesting the nature of being an aldehyde reductase. PMID:24509923

  15. Characterization of an allylic/benzyl alcohol dehydrogenase from Yokenella sp. strain WZY002, an organism potentially useful for the synthesis of α,β-unsaturated alcohols from allylic aldehydes and ketones.

    PubMed

    Ying, Xiangxian; Wang, Yifang; Xiong, Bin; Wu, Tingting; Xie, Liping; Yu, Meilan; Wang, Zhao

    2014-04-01

    A novel whole-cell biocatalyst with high allylic alcohol-oxidizing activities was screened and identified as Yokenella sp. WZY002, which chemoselectively reduced the C=O bond of allylic aldehydes/ketones to the corresponding α,β-unsaturated alcohols at 30°C and pH 8.0. The strain also had the capacity of stereoselectively reducing aromatic ketones to (S)-enantioselective alcohols. The enzyme responsible for the predominant allylic/benzyl alcohol dehydrogenase activity was purified to homogeneity and designated YsADH (alcohol dehydrogenase from Yokenella sp.), which had a calculated subunit molecular mass of 36,411 Da. The gene encoding YsADH was subsequently expressed in Escherichia coli, and the purified recombinant YsADH protein was characterized. The enzyme strictly required NADP(H) as a coenzyme and was putatively zinc dependent. The optimal pH and temperature for crotonaldehyde reduction were pH 6.5 and 65°C, whereas those for crotyl alcohol oxidation were pH 8.0 and 55°C. The enzyme showed moderate thermostability, with a half-life of 6.2 h at 55°C. It was robust in the presence of organic solvents and retained 87.5% of the initial activity after 24 h of incubation with 20% (vol/vol) dimethyl sulfoxide. The enzyme preferentially catalyzed allylic/benzyl aldehydes as the substrate in the reduction of aldehydes/ketones and yielded the highest activity of 427 U mg(-1) for benzaldehyde reduction, while the alcohol oxidation reaction demonstrated the maximum activity of 79.9 U mg(-1) using crotyl alcohol as the substrate. Moreover, kinetic parameters of the enzyme showed lower Km values and higher catalytic efficiency for crotonaldehyde/benzaldehyde and NADPH than for crotyl alcohol/benzyl alcohol and NADP(+), suggesting the nature of being an aldehyde reductase. PMID:24509923

  16. Reactions of tetraphenyltitanium with organic acids

    SciTech Connect

    Razuvaev, G.A.; Vyshinskaya, L.I.; Vasil'eva, G.A.

    1987-12-10

    As a result of the reactions of tetraphenyltitanium with dibasic organic acids high yields were obtained of new thermally stable titanium(III) complexes: phenyltitanium(III)carboxylates. Under the action of proton-active reagents (hydrochloric acid, cyclopentadiene, methanol) the latter break down with the breakage of titanium-phenyl bond. The proposed structure was based on IR- and ESR-spectral data. The dinuclear structure of the complexes was established on the basis of a study of the triplet structure of the ESR spectra, which showed the existence of intermolecular titanium-titanium exchange through methylene groups of the dicarboxylate bridges.

  17. Energy densification of biomass-derived organic acids

    DOEpatents

    Wheeler, M. Clayton; van Walsum, G. Peter; Schwartz, Thomas J.; van Heiningen, Adriaan

    2013-01-29

    A process for upgrading an organic acid includes neutralizing the organic acid to form a salt and thermally decomposing the resulting salt to form an energy densified product. In certain embodiments, the organic acid is levulinic acid. The process may further include upgrading the energy densified product by conversion to alcohol and subsequent dehydration.

  18. Treatment of broiler litter with organic acids.

    PubMed

    Ivanov, I E

    2001-04-01

    Experiments for treatment of contaminated broiler litter with citric, tartaric and salicylic acids were performed. At days 2 and 6 after the treatment, pH values (using a pH-meter), the ammonia concentrations (titration with 0.1 N HCl) and the microbial cells counts were determined in both experimental and control specimens of litter. The cost of acidification of litter was also determined. Our studies showed that the treatment of the contaminated litter with 5 per cent citric acid, 4 per cent tartaric acid and 1.5 per cent salicylic acid created an acid medium with pH under 5.0 and thus reduced the microbial counts to 2.2 x 10(3)colony forming units per gram manure litter. The treatment reduced the content of ammonia in the litter and in the air under the hygienic limits, i.e. 25-50 ppm. The cost of acidification of litter with these organic acids amounted to 0.1 $ per bird and 1.5 $ per 15 birds on one square metre in a growth period of 50 days. PMID:11356097

  19. Molecular Mechanisms of Aldehyde Toxicity: A Chemical Perspective

    PubMed Central

    2015-01-01

    Aldehydes are electrophilic compounds to which humans are pervasively exposed. Despite a significant health risk due to exposure, the mechanisms of aldehyde toxicity are poorly understood. This ambiguity is likely due to the structural diversity of aldehyde derivatives and corresponding differences in chemical reactions and biological targets. To gain mechanistic insight, we have used parameters based on the hard and soft, acids and bases (HSAB) theory to profile the different aldehyde subclasses with respect to electronic character (softness, hardness), electrophilic reactivity (electrophilic index), and biological nucleophilic targets. Our analyses indicate that short chain aldehydes and longer chain saturated alkanals are hard electrophiles that cause toxicity by forming adducts with hard biological nucleophiles, e.g., primary nitrogen groups on lysine residues. In contrast, α,β-unsaturated carbonyl derivatives, alkenals, and the α-oxoaldehydes are soft electrophiles that preferentially react with soft nucleophilic thiolate groups on cysteine residues. The aldehydes can therefore be grouped into subclasses according to common electronic characteristics (softness/hardness) and molecular mechanisms of toxicity. As we will discuss, the toxic potencies of these subgroups are generally related to corresponding electrophilicities. For some aldehydes, however, predictions of toxicity based on electrophilicity are less accurate due to inherent physicochemical variables that limit target accessibility, e.g., steric hindrance and solubility. The unsaturated aldehydes are also members of the conjugated type-2 alkene chemical class that includes α,β-unsaturated amide, ketone, and ester derivatives. Type-2 alkenes are electrophiles of varying softness and electrophilicity that share a common mechanism of toxicity. Therefore, exposure to an environmental mixture of unsaturated carbonyl derivatives could cause “type-2 alkene toxicity” through additive interactions

  20. Toxic Diatom Aldehydes Affect Defence Gene Networks in Sea Urchins.

    PubMed

    Varrella, Stefano; Romano, Giovanna; Costantini, Susan; Ruocco, Nadia; Ianora, Adrianna; Bentley, Matt G; Costantini, Maria

    2016-01-01

    Marine organisms possess a series of cellular strategies to counteract the negative effects of toxic compounds, including the massive reorganization of gene expression networks. Here we report the modulated dose-dependent response of activated genes by diatom polyunsaturated aldehydes (PUAs) in the sea urchin Paracentrotus lividus. PUAs are secondary metabolites deriving from the oxidation of fatty acids, inducing deleterious effects on the reproduction and development of planktonic and benthic organisms that feed on these unicellular algae and with anti-cancer activity. Our previous results showed that PUAs target several genes, implicated in different functional processes in this sea urchin. Using interactomic Ingenuity Pathway Analysis we now show that the genes targeted by PUAs are correlated with four HUB genes, NF-κB, p53, δ-2-catenin and HIF1A, which have not been previously reported for P. lividus. We propose a working model describing hypothetical pathways potentially involved in toxic aldehyde stress response in sea urchins. This represents the first report on gene networks affected by PUAs, opening new perspectives in understanding the cellular mechanisms underlying the response of benthic organisms to diatom exposure. PMID:26914213

  1. Toxic Diatom Aldehydes Affect Defence Gene Networks in Sea Urchins

    PubMed Central

    Varrella, Stefano; Ruocco, Nadia; Ianora, Adrianna; Bentley, Matt G.; Costantini, Maria

    2016-01-01

    Marine organisms possess a series of cellular strategies to counteract the negative effects of toxic compounds, including the massive reorganization of gene expression networks. Here we report the modulated dose-dependent response of activated genes by diatom polyunsaturated aldehydes (PUAs) in the sea urchin Paracentrotus lividus. PUAs are secondary metabolites deriving from the oxidation of fatty acids, inducing deleterious effects on the reproduction and development of planktonic and benthic organisms that feed on these unicellular algae and with anti-cancer activity. Our previous results showed that PUAs target several genes, implicated in different functional processes in this sea urchin. Using interactomic Ingenuity Pathway Analysis we now show that the genes targeted by PUAs are correlated with four HUB genes, NF-κB, p53, δ-2-catenin and HIF1A, which have not been previously reported for P. lividus. We propose a working model describing hypothetical pathways potentially involved in toxic aldehyde stress response in sea urchins. This represents the first report on gene networks affected by PUAs, opening new perspectives in understanding the cellular mechanisms underlying the response of benthic organisms to diatom exposure. PMID:26914213

  2. Arterial Blood Carbonic Acid Inversely Determines Lactic and Organic Acids

    PubMed Central

    Aiken, Christopher Geoffrey Alexander

    2013-01-01

    Objective: To establish that arterial blood carbonic acid varies inversely with lactic acid in accordance with bicarbonate exchanging for lactate across cell membranes through the anion exchange mechanism to maintain the Gibbs-Donnan equilibrium. Study Design: Over 5 years, lactate was measured on all blood gases taken from neonatal admissions, as well as organic acid whenever electrolytes were required. Results: Arterial blood gases from 63 infants given high calcium TPN were analyzed. Twenty two needed continuous positive airways pressure (CPAP) only and 31 intermittent positive pressure ventilation (IPPV) and surfactant followed by CPAP to treat respiratory distress syndrome in 51 and meconium aspiration syndrome in 2. All survived and were free of infection. Excluded gases were those with high and falling lactate soon after delivery representing perinatal asphyxia, and those on dexamethasone. Strong inverse relations between carbonic and lactic acids were found at all gestational ages and, independent of glomerular filtration, between carbonic and organic acids. Lactate (mmol/L) = 62.53 X PCO2 -0.96(mmHg) r2 0.315, n 1232, p <0.001. Sixty divided by PCO2 is a convenient measure of physiological lactate at any given PCO2. In the first week, 9.13 ± 2.57% of arterial gases from infants on IPPV had lactates above 120/PCO2, significantly more than 4.74 ± 2.73% on CPAP (p<0.05) and 2.47 ± 2.39% on no support. Conclusion: Changes in arterial blood carbonic acid cause immediate inverse changes in lactic acid, because their anions interchange across cell membranes according to the Gibbs –Donnan equilibrium. Increasing PCO2 from 40 to 120 mmHg decreased lactate from 1.5 mmol/L to 0.5 mmol/L, so that the sum of carbonic and lactic acids increased from 2.72 mmol/L to only 4.17 mmol/L. This helps explain the neuroprotective effect of hypercapnoea and highlights the importance of avoiding any degree of hypocapnoea in infants on IPPV. PMID:24392387

  3. Neurotoxicity of reactive aldehydes: the concept of "aldehyde load" as demonstrated by neuroprotection with hydroxylamines.

    PubMed

    Wood, Paul L; Khan, M Amin; Kulow, Sarah R; Mahmood, Siddique A; Moskal, Joseph R

    2006-06-20

    The concept of "oxidative stress" has become a mainstay in the field of neurodegeneration but has failed to differentiate critical events from epiphenomena and sequalae. Furthermore, the translation of current concepts of neurodegenerative mechanisms into effective therapeutics for neurodegenerative diseases has been meager and disappointing. A corollary of current concepts of "oxidative stress" is that of "aldehyde load". This relates to the production of reactive aldehydes that covalently modify proteins, nucleic acids, lipids and carbohydrates and activate apoptotic pathways. However, reactive aldehydes can also be generated by mechanisms other than "oxidative stress". We therefore hypothesized that agents that can chemically neutralize reactive aldehydes should demonstrate superior neuroprotective actions to those of free radical scavengers. To this end, we evaluated hydroxylamines as aldehyde-trapping agents in an in vitro model of neurodegeneration induced by the reactive aldehyde, 3-aminopropanal (3-AP), a product of polyamine oxidase metabolism of spermine and spermidine. In this model, the hydroxylamines N-benzylhydroxylamine, cyclohexylhydroxylamine and t-butylhydroxylamine were shown to protect, in a concentration-dependent manner, against 3-AP neurotoxicity. Additionally, a therapeutic window of 3 h was demonstrated for delayed administration of the hydroxylamines. In contrast, the free radical scavengers TEMPO and TEMPONE and the anti-oxidant ascorbic acid were ineffective in this model. Extending these tissue culture findings in vivo, we examined the actions of N-benzylhydroxylamine in the trimethyltin (TMT) rat model of hippocampal CA3 neurodegeneration. This model involves augmented polyamine metabolism resulting in the generation of reactive aldehydes that compromise mitochondrial integrity. In the rat TMT model, NBHA (50 mg/kg, sc, daily) provided 100% protection against neurodegeneration, as reflected by measurements of KCl-evoked glutamate

  4. REMOVAL OF ALDEHYDES FROM INDOOR AIR: ELUCIDATING ADSORPTION MECHANISMS, MODELING COMPETITIVE ADSORPTION, AND PREDICTING REMOVAL IN GAS-PHASE AIR CLEANERS

    EPA Science Inventory

    This research project will identify specific chemical and physical characteristics of activated carbon surfaces that promote the removal of gas-phase, polar organic pollutants. It is expected that basic and acidic functional groups will influence aldehyde adsorption through di...

  5. Contributions of Acid-Catalysed Processes to Secondary Organic Aerosol Mass - A Modelling pproach

    NASA Astrophysics Data System (ADS)

    Ervens, B.; Feingold, G.; Kreidenweis, S. M.

    2005-12-01

    A significant fraction of secondary organic aerosol (SOA) mass is formed by chemical and/or physical processes. However, the amount of organic material found in ambient organic aerosols cannot be explained with current models. Recently, several laboratory studies have been published which suggest that also acid-catalyzed processes that occur either in particles or at their surfaces (heterogeneous) might contribute significantly to mass formation. However, to date there is no general conclusion about the efficiency of such processes due to the great diversity of species and experimental conditions. We present a compilation of literature data (thermodynamic and kinetic) of these processes. The aerosol yields of (i) additional species which are thought previously not contribute to SOA formation (e.g. isoprene, aliphatic aldehydes) and (ii) species which form apparently higher SOA masses on acidic seed aerosols are reported and compared to input data of previous SOA models. Available kinetic data clearly exclude aldol condensation as a significant process for SOA formation on a time scale of typical aerosol life times. Using aerosol size distributions and gas phase concentrations measured during NEAQS2002 as model input data, we show that (even under assumption of equilibrium conditions) these additional processes only contribute a minor fraction to the organic aerosol mass.

  6. Rice Aldehyde Dehydrogenase7 Is Needed for Seed Maturation and Viability1[W][OA

    PubMed Central

    Shin, Jun-Hye; Kim, Sung-Ryul; An, Gynheung

    2009-01-01

    Aldehyde dehydrogenases (ALDHs) catalyze the irreversible oxidation of a wide range of reactive aldehydes to their corresponding carboxylic acids. Although the proteins have been studied from various organisms and at different growth stages, their roles in seed development have not been well elucidated. We obtained T-DNA insertional mutants in OsALDH7, which is remarkably inducible by oxidative and abiotic stresses. Interestingly, endosperms from the osaldh7 null mutants accumulated brown pigments during desiccation and storage. Extracts from the mutant seeds showed a maximum absorbance peak at 360 nm, the wavelength that melanoidin absorbs. Under UV light, those extracts also exhibited much stronger fluorescence than the wild type, suggesting that the pigments are melanoidin. These pigments started to accumulate in the late seed developmental stage, the time when OsALDH7 expression began to increase significantly. Purified OsALDH7 protein showed enzyme activities to malondialdehyde, acetaldehyde, and glyceraldehyde. These results suggest that OsALDH7 is involved in removing various aldehydes formed by oxidative stress during seed desiccation. The mutant seeds were more sensitive to our accelerated aging treatment and accumulated more malondialdehyde than the wild type. These data imply that OsALDH7 plays an important role in maintaining seed viability by detoxifying the aldehydes generated by lipid peroxidation. PMID:19052152

  7. Mechanistic Insights from Reaction of α-Oxiranyl-Aldehydes with Cyanobacterial Aldehyde Deformylating Oxygenase

    PubMed Central

    Das, Debasis; Ellington, Benjamin; Paul, Bishwajit; Marsh, E. Neil G.

    2014-01-01

    The biosynthesis of long-chain aliphatic hydrocarbons, which are derived from fatty acids, is widespread in Nature. The last step in this pathway involves the decarbonylation of fatty aldehydes to the corresponding alkanes or alkenes. In cyanobacteria this is catalyzed by an aldehyde deformylating oxygenase. We have investigated the mechanism of this enzyme using substrates bearing an oxirane ring adjacent to the aldehyde carbon. The enzyme catalyzed the deformylation of these substrates to produce the corresponding oxiranes. Performing the reaction in D2O allowed the facial selectivity of proton addition to be examined by 1H-NMR spectroscopy. The proton is delivered with equal probability to either face of the oxirane ring, indicating the formation of an oxiranyl radical intermediate that is free to rotate during the reaction. Unexpectedly, the enzyme also catalyzes a side reaction in which oxiranyl-aldehydes undergo tandem deformylation to furnish alkanes two carbons shorter. We present evidence that this involves the rearrangement of the intermediate oxiranyl radical formed in the first step, resulting an aldehyde that is further deformylated in a second step. These observations provide support for a radical mechanism for deformylation and, furthermore, allow the lifetime of the radical intermediate to be estimated based on prior measurements of rate constants for the rearrangement of oxiranyl radicals. PMID:24313866

  8. Aldehydes and sugars from evolved precometary ice analogs: Importance of ices in astrochemical and prebiotic evolution

    PubMed Central

    de Marcellus, Pierre; Meinert, Cornelia; Myrgorodska, Iuliia; Nahon, Laurent; Buhse, Thomas; d’Hendecourt, Louis Le Sergeant; Meierhenrich, Uwe J.

    2015-01-01

    Evolved interstellar ices observed in dense protostellar molecular clouds may arguably be considered as part of precometary materials that will later fall on primitive telluric planets, bringing a wealth of complex organic compounds. In our laboratory, experiments reproducing the photo/thermochemical evolution of these ices are routinely performed. Following previous amino acid identifications in the resulting room temperature organic residues, we have searched for a different family of molecules of potential prebiotic interest. Using multidimensional gas chromatography coupled to time-of-flight mass spectrometry, we have detected 10 aldehydes, including the sugar-related glycolaldehyde and glyceraldehyde—two species considered as key prebiotic intermediates in the first steps toward the synthesis of ribonucleotides in a planetary environment. The presence of ammonia in water and methanol ice mixtures appears essential for the recovery of these aldehydes in the refractory organic residue at room temperature, although these products are free of nitrogen. We finally point out the importance of detecting aldehydes and sugars in extraterrestrial environments, in the gas phase of hot molecular clouds, and, more importantly, in comets and in primitive meteorites that have most probably seeded the Earth with organic material as early as 4.2 billion years ago. PMID:25583475

  9. Capture and release of acid-gasses with acid-gas binding organic compounds

    DOEpatents

    Heldebrant, David J; Yonker, Clement R; Koech, Phillip K

    2015-03-17

    A system and method for acid-gas capture wherein organic acid-gas capture materials form hetero-atom analogs of alkyl-carbonate when contacted with an acid gas. These organic-acid gas capture materials include combinations of a weak acid and a base, or zwitterionic liquids. This invention allows for reversible acid-gas binding to these organic binding materials thus allowing for the capture and release of one or more acid gases. These acid-gas binding organic compounds can be regenerated to release the captured acid gasses and enable these organic acid-gas binding materials to be reused. This enables transport of the liquid capture compounds and the release of the acid gases from the organic liquid with significant energy savings compared to current aqueous systems.

  10. Benzoic Acid Catalyzed Annulations of α-Amino Acids and Aromatic Aldehydes Containing an ortho-Michael Acceptor: Access to 2,5-Dihydro-1H-benzo[c]azepines and 10,11-Dihydro-5H-benzo[e]pyrrolo[1,2-a]azepines.

    PubMed

    Tang, Mi; Tong, Lingfeng; Ju, Lei; Zhai, Wanwan; Hu, Yang; Yu, Xinhong

    2015-11-01

    A novel one-pot efficient synthesis of 2,5-dihydro-1H-benzo[c]azepines and 10,11-dihydro-5H-benzo[e]pyrrolo[1,2-a]azepines from α-amino acids and aromatic aldehydes containing an ortho-Michael acceptor is reported via decarboxylative annulations without metal catalysts in yields of 52-91%. Under microwave irradiation, this protocol provides rapid access to polycyclic ring systems (only 5 min in most cases). PMID:26488671

  11. Production of long chain alcohols and alkanes upon coexpression of an acyl-ACP reductase and aldehyde-deformylating oxgenase with a bacterial type-I fatty acid synthase in E. coli

    DOE PAGESBeta

    Coursolle, Dan; Shanklin, John; Lian, Jiazhang; Zhao, Huimin

    2015-06-23

    Microbial long chain alcohols and alkanes are renewable biofuels that could one day replace petroleum-derived fuels. Here we report a novel pathway for high efficiency production of these products in Escherichia coli strain BL21(DE3). We first identified the acyl-ACP reductase/aldehyde deformylase combinations with the highest activity in this strain. Next, we used catalase coexpression to remove toxic byproducts and increase the overall titer. Finally, by introducing the type-I fatty acid synthase from Corynebacterium ammoniagenes, we were able to bypass host regulatory mechanisms of fatty acid synthesis that have thus far hampered efforts to optimize the yield of acyl-ACP-derived products inmore » BL21(DE3). When all these engineering strategies were combined with subsequent optimization of fermentation conditions, we were able to achieve a final titer around 100 mg/L long chain alcohol/alkane products including a 57 mg/L titer of pentadecane, the highest titer reported in E. coli BL21(DE3) to date. The expression of prokaryotic type-I fatty acid synthases offer a unique strategy to produce fatty acid-derived products in E. coli that does not rely exclusively on the endogenous type-II fatty acid synthase system.« less

  12. Production of long chain alcohols and alkanes upon coexpression of an acyl-ACP reductase and aldehyde-deformylating oxgenase with a bacterial type-I fatty acid synthase in E. coli

    SciTech Connect

    Coursolle, Dan; Shanklin, John; Lian, Jiazhang; Zhao, Huimin

    2015-06-23

    Microbial long chain alcohols and alkanes are renewable biofuels that could one day replace petroleum-derived fuels. Here we report a novel pathway for high efficiency production of these products in Escherichia coli strain BL21(DE3). We first identified the acyl-ACP reductase/aldehyde deformylase combinations with the highest activity in this strain. Next, we used catalase coexpression to remove toxic byproducts and increase the overall titer. Finally, by introducing the type-I fatty acid synthase from Corynebacterium ammoniagenes, we were able to bypass host regulatory mechanisms of fatty acid synthesis that have thus far hampered efforts to optimize the yield of acyl-ACP-derived products in BL21(DE3). When all these engineering strategies were combined with subsequent optimization of fermentation conditions, we were able to achieve a final titer around 100 mg/L long chain alcohol/alkane products including a 57 mg/L titer of pentadecane, the highest titer reported in E. coli BL21(DE3) to date. The expression of prokaryotic type-I fatty acid synthases offer a unique strategy to produce fatty acid-derived products in E. coli that does not rely exclusively on the endogenous type-II fatty acid synthase system.

  13. Production of long chain alcohols and alkanes upon coexpression of an acyl-ACP reductase and aldehyde-deformylating oxygenase with a bacterial type-I fatty acid synthase in E. coli.

    PubMed

    Coursolle, Dan; Lian, Jiazhang; Shanklin, John; Zhao, Huimin

    2015-09-01

    Microbial long chain alcohols and alkanes are renewable biofuels that could one day replace petroleum-derived fuels. Here we report a novel pathway for high efficiency production of these products in Escherichia coli strain BL21(DE3). We first identified the acyl-ACP reductase/aldehyde deformylase combinations with the highest activity in this strain. Next, we used catalase coexpression to remove toxic byproducts and increase the overall titer. Finally, by introducing the type-I fatty acid synthase from Corynebacterium ammoniagenes, we were able to bypass host regulatory mechanisms of fatty acid synthesis that have thus far hampered efforts to optimize the yield of acyl-ACP-derived products in BL21(DE3). When all these engineering strategies were combined with subsequent optimization of fermentation conditions, we were able to achieve a final titer around 100 mg L(-1) long chain alcohol/alkane products including a 57 mg L(-1) titer of pentadecane, the highest titer reported in E. coli BL21(DE3) to date. The expression of prokaryotic type-I fatty acid synthases offer a unique strategy to produce fatty acid-derived products in E. coli that does not rely exclusively on the endogenous type-II fatty acid synthase system. PMID:26135500

  14. Aldehydes in hydrothermal solution - Standard partial molal thermodynamic properties and relative stabilities at high temperatures and pressures

    NASA Technical Reports Server (NTRS)

    Schulte, Mitchell D.; Shock, Everett L.

    1993-01-01

    Aldehydes are common in a variety of geologic environments and are derived from a number of sources, both natural and anthropogenic. Experimental data for aqueous aldehydes were taken from the literature and used, along with parameters for the revised Helgeson-Kirkham-Flowers (HKF) equations of state, to estimate standard partial molal thermodynamic data for aqueous straight-chain alkyl aldehydes at high temperatures and pressures. Examples of calculations involving aldehydes in geological environments are given, and the stability of aldehydes relative to carboxylic acids is evaluated. These calculations indicate that aldehydes may be intermediates in the formation of carboxylic acids from hydrocarbons in sedimentary basin brines and hydrothermal systems like they are in the atmosphere. The data and parameters summarized here allow evaluation of the role of aldehydes in the formation of prebiotic precursors, such as amino acids and hydroxy acids on the early Earth and in carbonaceous chondrite parent bodies.

  15. Aldehydes in hydrothermal solution: Standard partial molal thermodynamic properties and relative stabilities at high temperatures and pressures

    SciTech Connect

    Schulte, M.D.; Shock, E.L. )

    1993-08-01

    Aldehydes are common in a variety of geologic environments and are derived from a number of sources, both natural and anthropogenic. Experimental data for aqueous aldehydes were taken from the literature and used, along with parameters for the revised Helgeson-Kirkham-Flowers (HKF) equations of state, to estimate standard partial molal thermodynamic data for aqueous straight-chain alkyl aldehydes at high temperatures and pressures. Examples of calculations involving aldehydes in geological environments are given, and the stability of aldehydes relative to carboxylic acids is evaluated. These calculations indicate that aldehydes may be intermediates in the formation of carboxylic acids from hydrocarbons in sedimentary basins brines and hydrothermal systems like they are in the atmosphere. The data and parameters summarized here allow evaluation of the role of aldehydes in the formation of prebiotic precursors, such as amino acids and hydroxy acids on the early Earth and in carbonaceous chondrite parent bodies. 97 refs., 5 figs., 3 tabs.

  16. SAXS fingerprints of aldehyde dehydrogenase oligomers.

    PubMed

    Tanner, John J

    2015-12-01

    Enzymes of the aldehyde dehydrogenase (ALDH) superfamily catalyze the nicotinamide adenine dinucleotide-dependent oxidation of aldehydes to carboxylic acids. ALDHs are important in detoxification of aldehydes, amino acid metabolism, embryogenesis and development, neurotransmission, oxidative stress, and cancer. Mutations in genes encoding ALDHs cause metabolic disorders, including alcohol flush reaction (ALDH2), Sjögren-Larsson syndrome (ALDH3A2), hyperprolinemia type II (ALDH4A1), γ-hydroxybutyric aciduria (ALDH5A1), methylmalonic aciduria (ALDH6A1), pyridoxine dependent epilepsy (ALDH7A1), and hyperammonemia (ALDH18A1). We previously reported crystal structures and small-angle X-ray scattering (SAXS) analyses of ALDHs exhibiting dimeric, tetrameric, and hexameric oligomeric states (Luo et al., Biochemistry 54 (2015) 5513-5522; Luo et al., J. Mol. Biol. 425 (2013) 3106-3120). Herein I provide the SAXS curves, radii of gyration, and distance distribution functions for the three types of ALDH oligomer. The SAXS curves and associated analysis provide diagnostic fingerprints that allow rapid identification of the type of ALDH oligomer that is present in solution. The data sets provided here serve as a benchmark for characterizing oligomerization of ALDHs. PMID:26693506

  17. [Comparison of demineralization of different organic acid to enamel].

    PubMed

    Liu, L; Yue, S; Jiang, H; Lu, T

    1998-05-01

    The rates of demineralization of 5 organic acids (mathanoic acid, formic acid, propionic acid, Lactic acid, acetic acid, mixed acid) to the bovine enamel were tested and analysed with the self-made calcium ionselective microelectrodes(Ca(2+)-ISME) basing on a neutral carriers of ETH1001. The results showed; 1. The difference between the rates of demineralization of formic acid and lactic acid, formic acid and propionic acid, formic acid and acetic acid, acetic acid and mixed acid, acetic acid and lactic acid, propionic acid and mixed acid, propionic acid and lactic acid, lactic acid and mixed acid were of great significance (P < 0.01); 2. The rates of demineralization of acetic and mixed acid decreased with time, due to saturation of the solution during demineralization; 3. Ca(2+)-ISME was of the advantages of simplicity, rapidity, sensitivity and accuracy. The results suggest that the cariogenic potential is related to different acid products of different cariogenic bacteria, and the degree of mineral saturation within solution affects the rate of demineralization. PMID:12214404

  18. FORMATION OF ACIDIC TRACE ORGANIC BY-PRODUCTS FROM THE CHLORINATION OF HUMIC ACIDS

    EPA Science Inventory

    A method for concentrating and analyzing acidic trace organics produced by the chlorination of humic acids at concentrations approximating common drinking water levels is described. Data are compared from several humic acid sources. Specific compound analyses of the extracts were...

  19. TEMPO-catalyzed aerobic oxidation of alcohols to aldehydes and ketones in ionic liquid [bmim][PF6].

    PubMed

    Ansari, Imtiaz A; Gree, Rene

    2002-05-01

    [reaction: see text]. A simple and mild TEMPO-CuCl catalyzed aerobic oxidation of primary and secondary alcohols to the corresponding aldehydes and ketones in ionic liquid [bmim][PF6] with no trace of overoxidation to carboxylic acids has been developed. The product can be isolated by a simple extraction with organic solvent, and the ionic liquid can be recycled or reused. PMID:11975615

  20. Purification Or Organic Acids Using Anion Exchange Chromatography.

    DOEpatents

    Ponnampalam; Elankovan

    2001-09-04

    Disclosed is a cost-effective method for purifying and acidifying carboxylic acids, including organic acids and amino acids. The method involves removing impurities by allowing the anionic form of the carboxylic acid to bind to an anion exchange column and washing the column. The carboxylic anion is displaced as carboxylic acid by washing the resin with a strong inorganic anion. This method is effective in removing organic carboxylic acids and amino acids from a variety of industrial sources, including fermentation broths, hydrolysates, and waste streams.

  1. Difficulties in Laboratory Studies and Astronomical Observations of Organic Molecules: Hydroxyacetone and Lactic Acid

    NASA Technical Reports Server (NTRS)

    Apponi, A. J.; Brewster, M. A.; Hoy, J.; Ziurys, L. M.

    2006-01-01

    For the past 35 years, radio astronomy has revealed a rich organic chemistry in the interstellar gas, which is exceptionally complex towards active star-forming regions. New solar systems condense out of this gas and may influence the evolution of life on newly formed planets. Much of the biologically important functionality is present among the some 130 gas-phase molecules found to date, including alcohols, aldehydes, ketones, acids, amines, amides and even the simplest sugar - glycolaldehyde. Still, many unidentified interstellar radio signals remain, and their identification relies on further laboratory study. The molecules hydroxyacetone and lactic acid are relatively small organic molecules, but possess rather complex rotational spectra owing to their high asymmetry. Hydroxyacetone is particularly problematic because it possess a very low barrier to internal rotation, and exhibits strong coupling of the free-rotor states with the overall rotation of the molecule. As in the case of acetamide, a full decomposition method was employed to order the resultant eigenstates onto normal asymmetric top eigenvectors.

  2. Cloning and heterologous expression of two aryl-aldehyde dehydrogenases from the white-rot basidiomycete Phanerochaete chrysosporium

    SciTech Connect

    Nakamura, Tomofumi; Ichinose, Hirofumi; Wariishi, Hiroyuki

    2010-04-09

    We identified two aryl-aldehyde dehydrogenase proteins (PcALDH1 and PcALDH2) from the white-rot basidiomycete Phanerochaete chrysosporium. Both PcALDHs were translationally up-regulated in response to exogenous addition of vanillin, one of the key aromatic compounds in the pathway of lignin degradation by basidiomycetes. To clarify the catalytic functions of PcALDHs, we isolated full-length cDNAs encoding these proteins and heterologously expressed the recombinant enzymes using a pET/Escherichia coli system. The open reading frames of both PcALDH1 and PcALDH2 consisted of 1503 nucleotides. The deduced amino acid sequences of both proteins showed high homologies with aryl-aldehyde dehydrogenases from other organisms and contained ten conserved domains of ALDHs. Moreover, a novel glycine-rich motif 'GxGxxxG' was located at the NAD{sup +}-binding site. The recombinant PcALDHs catalyzed dehydrogenation reactions of several aryl-aldehyde compounds, including vanillin, to their corresponding aromatic acids. These results strongly suggested that PcALDHs metabolize aryl-aldehyde compounds generated during fungal degradation of lignin and various aromatic xenobiotics.

  3. Biobased organic acids production by metabolically engineered microorganisms.

    PubMed

    Chen, Yun; Nielsen, Jens

    2016-02-01

    Bio-based production of organic acids via microbial fermentation has been traditionally used in food industry. With the recent desire to develop more sustainable bioprocesses for production of fuels, chemicals and materials, the market for microbial production of organic acids has been further expanded as organic acids constitute a key group among top building block chemicals that can be produced from renewable resources. Here we review the current status for production of citric acid and lactic acid, and we highlight the use of modern metabolic engineering technologies to develop high performance microbes for production of succinic acid and 3-hydroxypropionic acid. Also, the key limitations and challenges in microbial organic acids production are discussed. PMID:26748037

  4. D-Amino Acids in Living Higher Organisms

    NASA Astrophysics Data System (ADS)

    Fujii, Noriko

    2002-04-01

    The homochirality of biological amino acids (L-amino acids) and of the RNA/DNA backbone (D-ribose) might have become established before the origin of life. It has been considered that D-amino acids and L-sugars were eliminated on the primitive Earth. Therefore, the presence and function of D-amino acids in living organisms have not been studied except for D-amino acids in the cell walls of microorganisms. However, D-amino acids were recently found in various living higher organisms in the form of free amino acids, peptides, and proteins. Free D-aspartate and D-serine are present and may have important physiological functions in mammals. D-amino acids in peptides are well known as opioid peptides and neuropeptides. In protein, D-aspartate residues increase during aging. This review deals with recent advances in the study of D-amino acids in higher organisms.

  5. Experimental study of the hydrothermal reactivity of organic acids and acid anions: II. Acetic acid, acetate, and valeric acid

    NASA Astrophysics Data System (ADS)

    McCollom, Thomas M.; Seewald, Jeffrey S.

    2003-10-01

    Organic acids and acid anions occur in substantial concentrations in many aqueous geologic fluids and are thought to take part in a variety of geochemical processes ranging from the transport of metals in ore-forming fluids to the formation of natural gas to serving as a metabolic energy source for microbes in subsurface habitats. The widespread occurrence of organic acids and their potential role in diverse geologic processes has led to numerous experimental studies of their thermal stability, yet there remain substantial gaps in our knowledge of the factors that control the rates and reaction pathways for the decomposition of these compounds under geologic conditions. In order to address some of these uncertainties, a series of laboratory experiments were conducted to examine the behavior of organic acids and acid anions under hydrothermal conditions in the presence of minerals. Reported here are results of experiments where aqueous solutions of acetic acid, sodium acetate, or valeric acid ( n-pentanoic acid) were heated at 325°C, 350 bars in the presence of the mineral assemblages hematite + magnetite + pyrite, pyrite + pyrrhotite + magnetite, and hematite + magnetite. The results indicate that aqueous acetic acid and acetate decompose by a combination of two reaction pathways: decarboxylation and oxidation. Both reactions are promoted by minerals, with hematite catalyzing the oxidation reaction while magnetite catalyzes decarboxylation. The oxidation reaction is much faster, so that oxidation dominates the decomposition of acetic acid and acetate when hematite is present. In contrast to previous reports that acetate decomposed more slowly than acetic acid, we found that acetate decomposed at slightly faster rates than the acid in the presence of minerals. Although longer-chain monocarboxylic acids are generally thought to decompose by decarboxylation, valeric acid appeared to decompose primarily by "deformylation" to 1-butene plus formic acid. Subsequent

  6. Polyvinyl alcohol cross-linked with two aldehydes

    NASA Technical Reports Server (NTRS)

    Sheibley, D. W.; Rieker, L. L.; Hsu, L. C.; Manzo, M. A. (Inventor)

    1982-01-01

    A film forming polyvinyl alcohol resin is admixed, in aqueous solution, with a dialdehyde crosslinking agent which is capable of crosslinking the polyvinyl alcohol resin and a water soluble acid aldehyde containing a reactive aldehyde group capable of reacting with hydroxyl groups in the polyvinyl alcohol resin and an ionizable acid hydrogen atom. The dialdehyde is present in an amount sufficient to react with from 1 to 20% by weight of the theoretical amount required to react with all of the hydroxyl groups of the polyvinyl alcohol. The amount of acid aldehyde is from 1 to 50% by weight, same basis, and is sufficient to reduce the pH of the aqueous admixture to 5 or less. The admixture is then formed into a desired physical shape, such as by casting a sheet or film, and the shaped material is then heated to simultaneously dry and crosslink the article.

  7. Temporal Variations of Organic Acids in Sumac Fruit

    SciTech Connect

    Robbins, C.; Mulcahy, F.; Somayajula, K.; Edenborn, H.M.

    2006-10-01

    Extracts from staghorn sumac (Rhus typhina) fruits were obtained from fresh fruits obtained from June to October in two successive years. Total acidity, pH, and concentrations of malic and succinic acids determined using liquid chromatography were measured for each extract. Acidity and acid concentrations reached their maxima in late July, and declined slowly thereafter. Malic and succinic acid concentrations in the extracts reached maxima of about 4 and 0.2% (expressed per unit weight of fruit), respectively. Malic and succinic acids were the only organic acids observed in the extracts, and mass balance determinations indicate that these acids are most likely the only ones present in appreciable amounts.

  8. 9-O-acetylated sialic acids differentiating normal haematopoietic precursors from leukemic stem cells with high aldehyde dehydrogenase activity in children with acute lymphoblastic leukaemia.

    PubMed

    Chowdhury, Suchandra; Chandra, Sarmila; Mandal, Chitra

    2014-10-01

    Childhood acute lymphoblastic leukaemia (ALL) originates from mutations in haematopoietic progenitor cells (HPCs). For high-risk patients, treated with intensified post-remission chemotherapy, haematopoietic stem cell (HSC) transplantation is considered. Autologous HSC transplantation needs improvisation till date. Previous studies established enhanced disease-associated expression of 9-O-acetylated sialoglycoproteins (Neu5,9Ac2-GPs) on lymphoblasts of these patients at diagnosis, followed by its decrease with clinical remission and reappearance with relapse. Based on this differential expression of Neu5,9Ac2-GPs, identification of a normal HPC population was targeted from patients at diagnosis. This study identifies two distinct haematopoietic progenitor populations from bone marrow of diagnostic ALL patients, exploring the differential expression of Neu5,9Ac2-GPs with stem cell (CD34, CD90, CD117, CD133), haematopoietic (CD45), lineage-commitment (CD38) antigens and cytosolic aldehyde dehydrogenase (ALDH). Normal haematopoietic progenitor cells (ALDH(+)SSC(lo)CD45(hi)Neu5,9Ac2 -GPs(lo)CD34(+)CD38(-)CD90(+)CD117(+)CD133(+)) differentiated into morphologically different, lineage-specific colonies, being crucial for autologous HSC transplantation while leukemic stem cells (ALDH(+)SSC(lo)CD45(lo)Neu5,9Ac2 -GPs(hi)CD34(+)CD38(+)CD90(-)CD117(-)CD133(-)) lacking this ability can be potential targets for minimal residual disease detection and drug-targeted immunotherapy. PMID:25283637

  9. [Characterization of aldehyde dehydrogenase gene fragment from mung bean Vigna radiata using the polymerase chain reaction].

    PubMed

    Ponomarev, A G; Bubiakina, V V; Tatarinova, T D; Zelenin, S M

    1998-01-01

    Two degenerate oligonucleotide sequence primers and polymerase chain reactions on total DNA have been utilized to clone on 651--bp gene fragment coding the central part of amino acid sequence of an earlier unknown aldehyde dehydrogenase (ALDH) from mung bean. The deduced partial amino acid sequence for this aldehyde dehydrogenase shows about 65% sequence identity to ALDHs of Vibrio cholerae Rhodococcus sp., Alcaligenes eutrophus and about 45% sequence identity to mammalian ALDHs 1 and 2, ALDHs of Aspergillus niger and A, nidulans, the betain aldehyde dehydrogenase from spinach. Alignment of the mung bean aldehyde dehydrogenase partial amino acid sequence with the sequence of 16 NAD(P)(+)-dependent aldehyde dehydrogenases has demonstrated that all strictly conserved amino acid residues and all three conservative regions are identical. PMID:9778740

  10. Organic Lecture Demonstrations.

    ERIC Educational Resources Information Center

    Silversmith, Ernest F.

    1988-01-01

    Provides a listing of 35 demonstrations designed to generate interest in organic chemistry and help put points across. Topics include opening lecture; molecular structure and properties; halogenation; nucleophilic substitution, alkenes and dienes, stereochemistry, spectroscopy, alcohols and phenols, aldehydes and ketones; carboxylic acids, amines,…

  11. Theoretical chemical kinetic study of the H-atom abstraction reactions from aldehydes and acids by Ḣ atoms and ȮH, HȮ2, and ĊH3 radicals.

    PubMed

    Mendes, Jorge; Zhou, Chong-Wen; Curran, Henry J

    2014-12-26

    We have performed a systematic, theoretical chemical kinetic investigation of H atom abstraction by Ḣ atoms and ȮH, HȮ2, and ĊH3 radicals from aldehydes (methanal, ethanal, propanal, and isobutanal) and acids (methanoic acid, ethanoic acid, propanoic acid, and isobutanoic acid). The geometry optimizations and frequencies of all of the species in the reaction mechanisms of the title reactions were calculated using the MP2 method and the 6-311G(d,p) basis set. The one-dimensional hindered rotor treatment for reactants and transition states and the intrinsic reaction coordinate calculations were also determined at the MP2/6-311G(d,p) level of theory. For the reactions of methanal and methanoic acid with Ḣ atoms and ȮH, HȮ2, and ĊH3 radicals, the calculated relative electronic energies were obtained with the CCSD(T)/cc-pVXZ (where X = D, T, and Q) method and were extrapolated to the complete basis set limit. The electronic energies obtained with the CCSD(T)/cc-pVTZ method were benchmarked against the CCSD(T)/CBS energies and were found to be within 1 kcal mol(-1) of one another. Thus, the energies calculated using the less expensive CCSD(T)/cc-pVTZ method were used in all of the reaction mechanisms and in calculating our high-pressure limit rate constants for the title reactions. Rate constants were calculated using conventional transition state theory with an asymmetric Eckart tunneling correction, as implemented in Variflex. Herein, we report the individual and average rate constants, on a per H atom basis, and total rate constants in the temperature range 500-2000 K. We have compared some of our rate constant results to available experimental and theoretical data, and our results are generally in good agreement. PMID:25387985

  12. Ni-Catalyzed Dehydrogenative Cross-Coupling: Direct Transformation of Aldehydes to Esters and Amides

    PubMed Central

    Whittaker, Aaron M.; Dong, Vy M.

    2015-01-01

    By exploring a new mode of Ni-catalyzed cross-coupling, we have developed a protocol to transform both aromatic and aliphatic aldehydes into either esters or amides directly. The success of this oxidative coupling depends on the appropriate choice of catalyst and organic oxidant, including the use of either α,α,α-trifluoroacetophenone or excess aldehyde. We present mechanistic data that supports a catalytic cycle involving oxidative addition into the aldehyde C–H bond. PMID:25424967

  13. Nickel-catalyzed dehydrogenative cross-coupling: direct transformation of aldehydes into esters and amides.

    PubMed

    Whittaker, Aaron M; Dong, Vy M

    2015-01-19

    By exploring a new mode of nickel-catalyzed cross-coupling, a method to directly transform both aromatic and aliphatic aldehydes into either esters or amides has been developed. The success of this oxidative coupling depends on the appropriate choice of catalyst and organic oxidant, including the use of either α,α,α-trifluoroacetophenone or excess aldehyde. Mechanistic data that supports a catalytic cycle involving oxidative addition into the aldehyde C-H bond is also presented. PMID:25424967

  14. ROLE OF SOIL ORGANIC ACIDS IN MINERAL WEATHERING PROCESSES

    EPA Science Inventory

    The soluble organic acids in soils consist largely of complex mixtures of polymeric compounds referred to collectively as fluvic and humic acids. These compounds are relatively refactory, and are broken down only slowly by bacteria. ow-molecular-mass acids (e.g., acetic, oxalic, ...

  15. Modeling the influence of organic acids on soil weathering

    USGS Publications Warehouse

    Lawrence, Corey R.; Harden, Jennifer W.; Maher, Kate

    2014-01-01

    Biological inputs and organic matter cycling have long been regarded as important factors in the physical and chemical development of soils. In particular, the extent to which low molecular weight organic acids, such as oxalate, influence geochemical reactions has been widely studied. Although the effects of organic acids are diverse, there is strong evidence that organic acids accelerate the dissolution of some minerals. However, the influence of organic acids at the field-scale and over the timescales of soil development has not been evaluated in detail. In this study, a reactive-transport model of soil chemical weathering and pedogenic development was used to quantify the extent to which organic acid cycling controls mineral dissolution rates and long-term patterns of chemical weathering. Specifically, oxalic acid was added to simulations of soil development to investigate a well-studied chronosequence of soils near Santa Cruz, CA. The model formulation includes organic acid input, transport, decomposition, organic-metal aqueous complexation and mineral surface complexation in various combinations. Results suggest that although organic acid reactions accelerate mineral dissolution rates near the soil surface, the net response is an overall decrease in chemical weathering. Model results demonstrate the importance of organic acid input concentrations, fluid flow, decomposition and secondary mineral precipitation rates on the evolution of mineral weathering fronts. In particular, model soil profile evolution is sensitive to kaolinite precipitation and oxalate decomposition rates. The soil profile-scale modeling presented here provides insights into the influence of organic carbon cycling on soil weathering and pedogenesis and supports the need for further field-scale measurements of the flux and speciation of reactive organic compounds.

  16. A new technique to determine organic and inorganic acid contamination.

    PubMed

    Vo, Evanly

    2002-01-01

    A new acid indicator pad was developed for the detection of acid breakthrough of gloves and chemical protective clothing. The pad carries a reagent which responds to acid contaminant by producing a color change. The pad was used to detect both organic and inorganic acids permeating through glove materials using the modified ASTM F-739 and direct permeability testing procedures. Breakthrough times for each type of glove were determined, and found to range from 4 min to > 4 h for propionic acid, from 3 min to > 4 h for acrylic acid, and from 26 min to > 4 h for HCl. A quantification was performed for propionic and acrylic acids following solvent desorption and gas chromatography. Both acids exhibited > 99% adsorption [the acid and its reactivity (the acid reacted with an indicator to contribute the color change)] on the pads at a spiking level of 1.8 microL for each acid. Acid recovery during quantification was calculated for each acid, ranging from 52-72% (RSD < or = 4.0%) for both acids over the spiking range 0.2-1.8 microL. The quantitative mass of the acids on the pads at the time of breakthrough detection ranged from 260-282 and 270-296 microg cm(-2) for propionic acid and acrylic acid, respectively. The new colorimetric indicator pad should be useful in detecting and collecting acid permeation samples through gloves and chemical protective clothing in both laboratory and field studies, for quantitative analysis. PMID:11827389

  17. Methods of making organic compounds by metathesis

    DOEpatents

    Abraham, Timothy W.; Kaido, Hiroki; Lee, Choon Woo; Pederson, Richard L.; Schrodi, Yann; Tupy, Michael John

    2015-09-01

    Described are methods of making organic compounds by metathesis chemistry. The methods of the invention are particularly useful for making industrially-important organic compounds beginning with starting compositions derived from renewable feedstocks, such as natural oils. The methods make use of a cross-metathesis step with an olefin compound to produce functionalized alkene intermediates having a pre-determined double bond position. Once isolated, the functionalized alkene intermediate can be self-metathesized or cross-metathesized (e.g., with a second functionalized alkene) to produce the desired organic compound or a precursor thereto. The method may be used to make bifunctional organic compounds, such as diacids, diesters, dicarboxylate salts, acid/esters, acid/amines, acid/alcohols, acid/aldehydes, acid/ketones, acid/halides, acid/nitriles, ester/amines, ester/alcohols, ester/aldehydes, ester/ketones, ester/halides, ester/nitriles, and the like.

  18. Composition of quince (Cydonia oblonga Miller) seeds: phenolics, organic acids and free amino acids.

    PubMed

    Silva, Branca M; Andrade, Paula B; Ferreres, Federico; Seabra, Rosa M; Oliveira, M Beatriz P P; Ferreira, Margarida A

    2005-04-01

    Phenolic compounds, organic acids and free amino acids of quince seeds were determined by HPLC/DAD, HPLC/UV and GC/FID, respectively. Quince seeds presented a phenolic profile composed of 3-O-caffeoylquinic, 4-O-caffeoylquinic, 5-O-caffeoylquinic and 3,5-dicaffeoylquinic acids, lucenin-2, vicenin-2, stellarin-2, isoschaftoside, schaftoside, 6-C-pentosyl-8-C-glucosyl chrysoeriol and 6-C-glucosyl-8-C-pentosyl chrysoeriol. Six identified organic acids constituted the organic acid profile of quince seeds: citric, ascorbic, malic, quinic, shikimic and fumaric acids. The free amino acid profile was composed of 21 identified free amino acids and the three most abundant were glutamic and aspartic acids and asparagine. PMID:15702641

  19. Carbon-Carbon Bond Formation and Hydrogen Production in the Ketonization of Aldehydes.

    PubMed

    Orozco, Lina M; Renz, Michael; Corma, Avelino

    2016-09-01

    Aldehydes possess relatively high chemical energy, which is the driving force for disproportionation reactions such as Cannizzaro and Tishchenko reactions. Generally, this energy is wasted if aldehydes are transformed into carboxylic acids with a sacrificial oxidant. Here, we describe a cascade reaction in which the surplus energy of the transformation is liberated as molecular hydrogen for the oxidation of heptanal to heptanoic acid by water, and the carboxylic acid is transformed into potentially industrially relevant symmetrical ketones by ketonic decarboxylation. The cascade reaction is catalyzed by monoclinic zirconium oxide (m-ZrO2 ). The reaction mechanism has been studied through cross-coupling experiments between different aldehydes and acids, and the final symmetrical ketones are formed by a reaction pathway that involves the previously formed carboxylic acids. Isotopic studies indicate that the carboxylic acid can be formed by a hydride shift from the adsorbed aldehyde on the metal oxide surface in the absence of noble metals. PMID:27539722

  20. On the source of organic acid aerosol layers above clouds.

    PubMed

    Sorooshian, Armin; Lu, Miao-Ling; Brechtel, Fred J; Jonsson, Haflidi; Feingold, Graham; Flagan, Richard C; Seinfeld, John H

    2007-07-01

    During the July 2005 Marine Stratus/Stratocumulus Experiment (MASE) and the August-September 2006 Gulf of Mexico Atmospheric Composition and Climate Study (GoMACCS), the Center for Interdisciplinary Remotely-Piloted Aircraft Studies (CIRPAS) Twin Otter probed aerosols and cumulus clouds in the eastern Pacific Ocean off the coast of northern California and in southeastern Texas, respectively. An on-board particle-into-liquid sampler (PILS) quantified inorganic and organic acid species with < or = 5-min time resolution. Ubiquitous organic aerosol layers above cloud with enhanced organic acid levels were observed in both locations. The data suggest that aqueous-phase reactions to produce organic acids, mainly oxalic acid, followed by droplet evaporation is a source of elevated organic acid aerosol levels above cloud. Oxalic acid is observed to be produced more efficiently relative to sulfate as the cloud liquid water content increases, corresponding to larger and less acidic droplets. As derived from large eddy simulations of stratocumulus underthe conditions of MASE, both Lagrangian trajectory analysis and diurnal cloudtop evolution provide evidence that a significant fraction of the aerosol mass concentration above cloud can be accounted for by evaporated droplet residual particles. Methanesulfonate data suggest that entrainment of free tropospheric aerosol can also be a source of organic acids above boundary layer clouds. PMID:17695910

  1. Gastric emptying of organic acids in the dog.

    PubMed

    Blum, A L; Hegglin, J; Krejs, G J; Largiadèr, F; Säuberli, H; Schmid, P

    1976-10-01

    Test meals of 300 ml. of six different organic acids were instilled into the stomach of six healthy mongrel dogs. Citric, acetic, propionic, lactic, tartaric and succinic acid were given in 50, 100, 150, and 200 mN concentrations. 2. During the emptying process, the gastric contents were aspirated and immediately re-instilled at 10 min intervals, and the following parameters were recorded: volume, concentration of the organic anion, pH, hydrogen ion concentration and osmolarity. 3. By multiple stepwise regression analysis, the combination of parameters which most effectively determines gastric emptying rate was found to be: concentration of the organic anion, followed by intragastric volume and number of previous test meals given on the same day. These three parameters appear in the equation for gastric emptying rate in which the individual characteristic of each acid is expressed by a constant. 4. Among the various acids, inhibition of emptying rate increases with rising number of carboxylic groups of the acid and its molecular weight. 5. After proximal gastric vagotomy, emptying rate of organic acids is independent of volume, and emptying approaches an exponential pattern. 6. A model for gastric emptying of organic acids with at least three different receptors is proposed: one for the structure of the organic acid, one for concentration and one for intragastric volume. PMID:10436

  2. Gastric emptying of organic acids in the dog.

    PubMed Central

    Blum, A L; Hegglin, J; Krejs, G J; Largiadèr, F; Säuberli, H; Schmid, P

    1976-01-01

    Test meals of 300 ml. of six different organic acids were instilled into the stomach of six healthy mongrel dogs. Citric, acetic, propionic, lactic, tartaric and succinic acid were given in 50, 100, 150, and 200 mN concentrations. 2. During the emptying process, the gastric contents were aspirated and immediately re-instilled at 10 min intervals, and the following parameters were recorded: volume, concentration of the organic anion, pH, hydrogen ion concentration and osmolarity. 3. By multiple stepwise regression analysis, the combination of parameters which most effectively determines gastric emptying rate was found to be: concentration of the organic anion, followed by intragastric volume and number of previous test meals given on the same day. These three parameters appear in the equation for gastric emptying rate in which the individual characteristic of each acid is expressed by a constant. 4. Among the various acids, inhibition of emptying rate increases with rising number of carboxylic groups of the acid and its molecular weight. 5. After proximal gastric vagotomy, emptying rate of organic acids is independent of volume, and emptying approaches an exponential pattern. 6. A model for gastric emptying of organic acids with at least three different receptors is proposed: one for the structure of the organic acid, one for concentration and one for intragastric volume. PMID:10436

  3. Organic acids composition of Cydonia oblonga Miller leaf.

    PubMed

    Oliveira, Andreia P; Pereira, José A; Andrade, Paula B; Valentão, Patrícia; Seabra, Rosa M; Silva, Branca M

    2008-11-15

    Organic acid profiles of 36 Cydonia oblonga Miller leaf samples, from three different geographical origins of northern (Bragança and Carrazeda de Ansiães) and central Portugal (Covilhã), harvested in three collection months (June, August and October of 2006), were determined by HPLC/UV (214nm). Quince leaves presented a common organic acid profile, composed of six constituents: oxalic, citric, malic, quinic, shikimic and fumaric acids. C. oblonga leaves total organic acid content varied from 1.6 to 25.8g/kg dry matter (mean value of 10.5g/kg dry matter). Quinic acid was the major compound (72.2%), followed by citric acid (13.6%). Significant differences were found in malic and quinic acids relative abundances and total organic acid contents according to collection time, which indicates a possible use of these compounds as maturity markers. Between June and August seems to be the best period to harvest quince leaves for preparation of decoctions or infusions, since organic acids total content is higher in this season. PMID:26047441

  4. Reactive Distillation for Esterification of Bio-based Organic Acids

    SciTech Connect

    Fields, Nathan; Miller, Dennis J.; Asthana, Navinchandra S.; Kolah, Aspi K.; Vu, Dung; Lira, Carl T.

    2008-09-23

    The following is the final report of the three year research program to convert organic acids to their ethyl esters using reactive distillation. This report details the complete technical activities of research completed at Michigan State University for the period of October 1, 2003 to September 30, 2006, covering both reactive distillation research and development and the underlying thermodynamic and kinetic data required for successful and rigorous design of reactive distillation esterification processes. Specifically, this project has led to the development of economical, technically viable processes for ethyl lactate, triethyl citrate and diethyl succinate production, and on a larger scale has added to the overall body of knowledge on applying fermentation based organic acids as platform chemicals in the emerging biorefinery. Organic acid esters constitute an attractive class of biorenewable chemicals that are made from corn or other renewable biomass carbohydrate feedstocks and replace analogous petroleum-based compounds, thus lessening U.S. dependence on foreign petroleum and enhancing overall biorefinery viability through production of value-added chemicals in parallel with biofuels production. Further, many of these ester products are candidates for fuel (particularly biodiesel) components, and thus will serve dual roles as both industrial chemicals and fuel enhancers in the emerging bioeconomy. The technical report from MSU is organized around the ethyl esters of four important biorenewables-based acids: lactic acid, citric acid, succinic acid, and propionic acid. Literature background on esterification and reactive distillation has been provided in Section One. Work on lactic acid is covered in Sections Two through Five, citric acid esterification in Sections Six and Seven, succinic acid in Section Eight, and propionic acid in Section Nine. Section Ten covers modeling of ester and organic acid vapor pressure properties using the SPEAD (Step Potential

  5. Recombinant microorganisms for increased production of organic acids

    DOEpatents

    Yi, Jian; Kleff, Susanne; Guettler, Michael V.

    2012-02-21

    Disclosed are recombinant microorganisms for producing organic acids. The recombinant microorganisms express a polypeptide that has the enzymatic activity of an enzyme that is utilized in the pentose phosphate cycle. The recombinant microorganism may include recombinant Actinobacillus succinogenes that has been transformed to express a Zwischenferment (Zwf) gene. The recombinant microorganisms may be useful in fermentation processes for producing organic acids such as succinic acid and lactic acid. Also disclosed are novel plasmids that are useful for transforming microorganisms to produce recombinant microorganisms that express enzymes such as Zwf.

  6. Recombinant microorganisms for increased production of organic acids

    DOEpatents

    Yi, Jian; Kleff, Susanne; Guettler, Michael V

    2013-04-30

    Disclosed are recombinant microorganisms for producing organic acids. The recombinant microorganisms express a polypeptide that has the enzymatic activity of an enzyme that is utilized in the pentose phosphate cycle. The recombinant microorganism may include recombinant Actinobacillus succinogenes that has been transformed to express a Zwischenferment (Zwf) gene. The recombinant microorganisms may be useful in fermentation processes for producing organic acids such as succinic acid and lactic acid. Also disclosed are novel plasmids that are useful for transforming microorganisms to produce recombinant microorganisms that express enzymes such as Zwf.

  7. ANALYSIS OF DNA STRAND BREAKS INDUCED IN RODENT LIVER IN VIVO, HEPATOCYTES IN VITRO, AND A HUMAN CELL LINE BY CHLORINATED ACETIC ACIDS AND ALDEHYDES

    EPA Science Inventory

    An alkaline unwinding assay was used to quantitate DNA strand breaks (DNA SB) in the livers of rats and mice, in rodent hepatocytes, and in CCRF-CEM cells following treatment with tri- (TCA), di- (DCA) and mono-(MCA) chloroacetic acid and tri-(CH), di)(DCAA) and mono- (CAA) chlor...

  8. Tribochemical processes in organic media

    SciTech Connect

    Chigarenko, G.G.; Barchan, G.P.; Ponomarenko, A.G.

    1982-11-01

    Investigates the influence of the chemical structure of a number of organic compounds of different classes on their lubricating properties and the processes in the friction zone. Uses monohydric, dihydric, and trihydric alcohols, aldehydes, alkylcarboxylic acids, dialkyl ethers, esters of monocarboxylic and dicarboxylic acids, and esters of hydroxy-acids as the lubricating medium. Finds that when friction takes place in a medium consisting of an organic compound that is less active than acids or aldehydes, an equilibrium optimal quantity of acid is formed by tribochemical means, and this tends to give a substantial reduction of the coefficient of friction and wear. Concludes that the formation of carboxyl-containing organic compounds is one of the tribochemical processes that are necessary to improve lubricity.

  9. [Use of organic acids in acne and skin discolorations therapy].

    PubMed

    Kapuścińska, Alicja; Nowak, Izabela

    2015-01-01

    Acne is one of the most frequent skin disorders that occurs in puberty, but often adults also have acne. The most important factors responsible for acne are elevated production of sebum by hyperactive sebaceous glands and blockage of the follicle because of hyperkeratosis [14]. The third etiopathogenic factor of acne is excessive microflora reproduction [8]. The most significant bacterium that is responsible for formation of skin lesions is Propionibacterium acnes, a rod-shaped Gram-positive and aerotolerant anaerobic bacterium. It is estimated that P. acnes is responsible for acne in approximately 80% of people aged 11 to 30 [27,40]. Even healed skin lesions can often cause skin discolorations and scar formation [51]. Exfoliating chemical substances that are commonly used in dermatology and cosmetology are organic acids. Exfoliating treatment using organic acids is called "chemical peeling" and consists of controlled application of those substances on the skin [38]. The depth of exfoliation depends on organic acid concentration, type of substance and contact time with the skin [41]. Using exfoliating agents seems to be helpful in excessive keratinization - one of several factors responsible for acne. Moreover, epidermis exfoliation is a popular method of removing skin discoloration [22]. Considering chemical structure, exfoliating substances that are most often used in cosmetology contain alpha-hydroxyacids (glycolic acid, lactic acid, mandelic acid and citric acid), beta-hydroxyacids (salicylic acid) and other organic acids, such as trichloroacetic acid and pyruvic acid [47]. In this article, a literature review of use of organic acids in acne and skin discoloration therapy is presented. PMID:25811473

  10. Ampholine-functionalized hybrid organic-inorganic silica material as sorbent for solid-phase extraction of acidic and basic compounds.

    PubMed

    Wang, Tingting; Chen, Yihui; Ma, Junfeng; Chen, Mingliang; Nie, Chenggang; Hu, Minjie; Li, Ying; Jia, Zhijian; Fang, Jianghua; Gao, Haoqi

    2013-09-20

    A novel sorbent for solid-phase extraction (SPE) was synthesized by chemical immobilization of ampholine on hybrid organic-inorganic silica material. The ampholine-functionalized hybrid organic-inorganic silica sorbent is consisted of aliphatic amine groups, carboxyl groups and long carbon chains, allowing for extraction of both acidic and basic compounds. The retention properties of the developed sorbent were evaluated for 1-hydroxy-2-naphthoic acid (HNA), 1-naphthoic acid (NA), 3-hydroxybenzoic acid (HBA), benzoic acid (BA), sorbic acid (SA), vanillic aldehyde (VA), butyl 4-hydroxybenzoate (BHB), propyl 4-hydroxybenzoate (PHB), ethyl 4-hydroxybenzoate (EHB), and methyl 4-hydroxybenzoate (MHB). The results show that such a sorbent has three types of interaction, i.e., electrostatic interaction, hydrophobic interaction, and hydrogen bonding, exhibiting high extraction efficiency towards the compounds tested. The adsorption capacities of the analytes ranged from 0.61 to 6.54μgmg(-1). The reproducibility of the sorbent preparation was evaluated at three spiking concentration levels, with relative standard deviations (RSDs) of 1.0-10.5%. The recoveries of ten acidic and basic compounds spiked in beverage Coca-Cola(®) sample ranged from 82.5% to 98.2% with RSDs less than 5.8%. Under optimum conditions, the ampholine-functionalized hybrid organic-inorganic silica sorbent rendered higher extraction efficiency for acidic compounds than that of the commercially available ampholine-functionalized silica particles, and was comparable to that of the commercial Oasis WAX and Oasis WCX. PMID:23953713

  11. Survey of organic acid eluents for anion chromatography

    SciTech Connect

    Book, D.E.

    1981-10-01

    Of all the potential eluents surveyed (including aromatic, sulfonic, phosphonic, among other acids), only the carboxylic acids and the nitrophenols are recommended as eluents for anion chromatography. The concentration of the eluent should be in the range 5 x 10/sup -5/ to 1 x 10/sup -3/ M. The eluent should have the same charge as inorganic anions, a higher charge than organic acid samples. Choice of eluents for separation of halides, chloride and sulfate, multivalent inorganic anions, small alkyl acids, and aromatic acids is discussed. (DLC)

  12. New phosphonate reagents for aldehyde homologation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    New phosphonate reagents were developed for the two-carbon homologation of aldehydes to unbranched- or methyl-branched unsaturated aldehydes. The phosphonate reagents, diethyl methylformyl-2-phosphonate dimethylhydrazone and diethyl ethylformyl-2-phosphonate dimethylhydrazone, contained a protected...

  13. ALDEHYDE DEHYDROGENASES EXPRESSION DURING POSTNATAL DEVELOPMENT: LIVER VS. LUNG

    EPA Science Inventory

    Aldehydes are highly reactive molecules present in the environment, and can be produced during biotransformation of xenobiotics. Although the lung can be a major target for aldehyde toxicity, development of aldehyde dehydrogenases (ALDHs), which detoxify aldehydes, in lung has be...

  14. Organic geochemistry of amino acids: Precambrian to recent

    SciTech Connect

    Engel, M.H.; Macko, S.A.

    1985-01-01

    Since the discovery of amino acids in fossils (Abelson, 1954), considerable effort has been made to elucidate the origin and distribution of amino acids in geologic materials. Racemization and decomposition reactions of amino acids and peptides derived via the natural hydrolysis of protein constituents of organisms have been extensively studied. While the ubiquity of amino acids presents a challenge for discerning their indigeneity in geologic samples, careful analyses have resulted in successful applications of amino acid racemization and decomposition reactions for investigations of geochronologic, paleoclimatic, stratigraphic, diagenetic and chemotaxonomic problems for Quaternary age samples. An investigation of amino acids in sediments from Baffin Island fjords indicates that their distribution may also provide data with respect to the relative contributions of marine and terrigenous organic matter to recent sediments. While the absence of unstable amino acids and the presence of racemic amino acids in a sample may preclude very recent contamination, the possibility of retardation of amino acid racemization rates subsequent to geopolymer formation must also be considered. Studies of amino acids in Paleozoic, Mesozoic and early Cenozoic age samples are limited. Precambrian samples, however, have received much attention, given the potential (however slight) for isolating compounds representative of the earliest living systems. A future approach for elucidating the origin(s) of amino acids in ancient samples may be analyses of their individual stable isotopic compositions.

  15. Association Mapping of Main Tomato Fruit Sugars and Organic Acids

    PubMed Central

    Zhao, Jiantao; Xu, Yao; Ding, Qin; Huang, Xinli; Zhang, Yating; Zou, Zhirong; Li, Mingjun; Cui, Lu; Zhang, Jing

    2016-01-01

    Association mapping has been widely used to map the significant associated loci responsible for natural variation in complex traits and are valuable for crop improvement. Sugars and organic acids are the most important metabolites in tomato fruits. We used a collection of 174 tomato accessions composed of Solanum lycopersicum (123 accessions) and S. lycopersicum var cerasiforme (51 accessions) to detect significantly associated loci controlling the variation of main sugars and organic acids. The accessions were genotyped with 182 SSRs spreading over the tomato genome. Association mapping was conducted on the main sugars and organic acids detected by gas chromatography-mass spectrometer (GC-MS) over 2 years using the mixed linear model (MLM). We detected a total of 58 significantly associated loci (P < 0.001) for the 17 sugars and organic acids, including fructose, glucose, sucrose, citric acid, malic acid. These results not only co-localized with several reported QTLs, including fru9.1/PV, suc9.1/PV, ca2.1/HS, ca3.1/PV, ca4.1/PV, and ca8.1/PV, but also provided a list of candidate significantly associated loci to be functionally validated. These significantly associated loci could be used for deciphering the genetic architecture of tomato fruit sugars and organic acids and for tomato quality breeding. PMID:27617019

  16. Association Mapping of Main Tomato Fruit Sugars and Organic Acids.

    PubMed

    Zhao, Jiantao; Xu, Yao; Ding, Qin; Huang, Xinli; Zhang, Yating; Zou, Zhirong; Li, Mingjun; Cui, Lu; Zhang, Jing

    2016-01-01

    Association mapping has been widely used to map the significant associated loci responsible for natural variation in complex traits and are valuable for crop improvement. Sugars and organic acids are the most important metabolites in tomato fruits. We used a collection of 174 tomato accessions composed of Solanum lycopersicum (123 accessions) and S. lycopersicum var cerasiforme (51 accessions) to detect significantly associated loci controlling the variation of main sugars and organic acids. The accessions were genotyped with 182 SSRs spreading over the tomato genome. Association mapping was conducted on the main sugars and organic acids detected by gas chromatography-mass spectrometer (GC-MS) over 2 years using the mixed linear model (MLM). We detected a total of 58 significantly associated loci (P < 0.001) for the 17 sugars and organic acids, including fructose, glucose, sucrose, citric acid, malic acid. These results not only co-localized with several reported QTLs, including fru9.1/PV, suc9.1/PV, ca2.1/HS, ca3.1/PV, ca4.1/PV, and ca8.1/PV, but also provided a list of candidate significantly associated loci to be functionally validated. These significantly associated loci could be used for deciphering the genetic architecture of tomato fruit sugars and organic acids and for tomato quality breeding. PMID:27617019

  17. [Effect of organic composition of humic acids on Enterobacteria multiplication].

    PubMed

    Buzoleva, L S; Sidorenko, M L

    2001-01-01

    Enterobacteria have been found to be capable of active multiplication in humic acids isolated from bentonite clays containing carbohydrates, lipids and proteins. Humic acids fractions have been found to be heterogeneous by their molecular weight and organic composition; consequently, they have been found to produce different influence in the multiplication of bacteria. PMID:11548272

  18. EFFECT OF ACIDITY ON SECONDARY ORGANIC AEROSOL FORMATION FROM ISOPRENE

    EPA Science Inventory

    The effect of particle-phase acidity on secondary organic aerosol (SOA) formation from isoprene is investigated in a laboratory chamber study, in which the acidity of the inorganic seed aerosol was controlled systematically. The observed enhancement in SOA mass concentration is c...

  19. Acoustic properties of organic acid mixtures in water

    NASA Technical Reports Server (NTRS)

    Macavei, I.; Petrisor, V.; Auslaender, D.

    1974-01-01

    The variation of the rate of propagation of ultrasounds in organic acid mixtures in water points to structural changes caused by interactions that take place under conditions of thermal agitation, at different acid concentrations. At the same time, a difference is found in the changes in velocity as a function of the length of the carbon chain of the acids in the mixture as a result of their effect on the groups of water molecules associated by hydrogen bonds.

  20. A UPLC-MS/MS method for simultaneous determination of danshensu, protocatechuic aldehyde, rosmarinic acid, and ligustrazine in rat plasma, and its application to pharmacokinetic studies of Shenxiong glucose injection in rats.

    PubMed

    Zheng, Lin; Gong, Zipeng; Lu, Yuan; Xie, Yumin; Huang, Yong; Liu, Yue; Lan, Yanyu; Wang, Aimin; Wang, Yonglin

    2015-08-01

    A rapid and sensitive ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed for the simultaneous determination of the four major active ingredients, danshensu, protocatechuic aldehyde, rosmarinic acid, and ligustrazine, in the traditional Chinese medicine Shenxiong glucose injection in rat plasma. Acidified and alkalized plasma samples were extracted using ethyl acetate, and separated on a Waters C18 column (2.1mm×50mm, 1.7μm) by using a gradient mobile phase system of acetonitrile-water containing 0.1% formic acid and luteoloside as an internal standard. Electrospray ionization in the positive-ion mode and multiple reaction monitoring were used to identify and quantitate the active components. All calibration curves showed good linearity (r>0.994) over the concentration range, with a lower limit of quantification (LLOQ) between 0.02 and 0.21μg/mL. The precision of the in vivo study was evaluated by intra- and inter-day assays, and the percentage of relative standard deviation was within 15%. Moreover, satisfactory extraction efficiency was obtained (between 83.94 and 117.81%) by liquid-liquid extraction. The validated method was successfully applied in a pharmacokinetic study in rats after intravenous administration of Shenxiong glucose injection. The results showed that the four bioactive ingredients in Shenxiong glucose injection have linear pharmacokinetic properties in rats after intravenous injection within the administered dose range and partially different ones compared to single ingredient. PMID:26118621

  1. Metabolic evolution of Escherichia coli strains that produce organic acids

    DOEpatents

    Grabar, Tammy; Gong, Wei; Yocum, R Rogers

    2014-10-28

    This invention relates to the metabolic evolution of a microbial organism previously optimized for producing an organic acid in commercially significant quantities under fermentative conditions using a hexose sugar as sole source of carbon in a minimal mineral medium. As a result of this metabolic evolution, the microbial organism acquires the ability to use pentose sugars derived from cellulosic materials for its growth while retaining the original growth kinetics, the rate of organic acid production and the ability to use hexose sugars as a source of carbon. This invention also discloses the genetic change in the microorganism that confers the ability to use both the hexose and pentose sugars simultaneously in the production of commercially significant quantities of organic acids.

  2. Reactions Between Water Soluble Organic Acids and Nitrates in Atmospheric Aerosols: Recycling of Nitric Acid and Formation of Organic Salts

    SciTech Connect

    Wang, Bingbing; Laskin, Alexander

    2014-03-25

    Atmospheric particles often include a complex mixture of nitrate and secondary organic materials accumulated within the same individual particles. Nitrate as an important inorganic component can be chemically formed in the atmosphere. For instance, formation of sodium nitrate (NaNO3) and calcium nitrate Ca(NO3)2 when nitrogen oxide and nitric acid (HNO3) species react with sea salt and calcite, respectively. Organic acids contribute a significant fraction of photochemically formed secondary organics that can condense on the preexisting nitrate-containing particles. Here, we present a systematic microanalysis study on chemical composition of laboratory generated particles composed of water soluble organic acids and nitrates (i.e. NaNO3 and Ca(NO3)2) investigated using computer controlled scanning electron microscopy with energy dispersive analysis of X-rays (CCSEM/EDX) and Fourier transform infrared micro-spectroscopy (micro-FTIR). The results show that water-soluble organic acids can react with nitrates releasing gaseous HNO3 during dehydration process. These reactions are attributed to acid displacement of nitrate with weak organic acids driven by the evaporation of HNO3 into gas phase due to its relatively high volatility. The reactions result in significant nitrate depletion and formation of organic salts in mixed organic acids/nitrate particles that in turn may affect their physical and chemical properties relevant to atmospheric environment and climate. Airborne nitrate concentrations are estimated by thermodynamic calculations corresponding to various nitrate depletions in selected organic acids of atmospheric relevance. The results indicate a potential mechanism of HNO3 recycling, which may further affect concentrations of gas- and aerosol-phase species in the atmosphere and the heterogeneous reaction chemistry between them.

  3. [Pollution Characteristics of Aldehydes and Ketones Compounds in the Exhaust of Beijing Typical Restaurants].

    PubMed

    Cheng, Jing-chen; Cui, Tong; He, Wan-qing; Nie, Lei; Wang, Jun-ling; Pan, Tao

    2015-08-01

    Aldehydes and ketones compounds, as one of the components in the exhaust of restaurants, are a class of volatile organic compounds (VOCs) with strong chemical reactivity. However, there is no systematic study on aldehydes and ketones compounds in the exhaust of restaurants. To further clarify the food source emission levels of aldehydes and ketones compounds and controlling measures, to access city group catering VOCs emissions control decision-making basis, this study selected 8 Beijing restaurants with different types. The aldehydes and ketones compounds were sampled using DNPH-silica tube, and then ultra performance liquid chromatography was used for quantitative measurement. The aldehydes and ketones concentrations of reference volume condition from 8 restaurants in descending order were Roasted Duck restaurant, Chinese Style Barbecue, Home Dishes, Western Fast-food, School Canteen, Chinese Style Fast-food, Sichuan Cuisine, Huaiyang Cuisine. The results showed that the range of aldehydes and ketones compounds (C1-C9) concentrations of reference volume condition in the exhaust of restaurants was 115.47-1035.99 microg x m(-3). The composition of aldehydes and ketones compounds in the exhaust of sampled restaurants was obviously different. The percentages of C1-C3 were above 40% in the exhaust from Chinese style restaurants. Fast food might emit more C4-C9 aldehydes and ketones compounds. From the current situation of existing aldehydes and ketones compounds control, the removal efficiency of high voltage electrostatic purifiers widely used in Beijing is limited. PMID:26591999

  4. [Inhibition of growth of microscopic fungi with organic acids].

    PubMed

    Conková, E; Para, L; Kocisová, A

    1993-01-01

    Fungicidal effects of five selected organic acids (lactic, acetic, formic, oxalic, and propionic) in concentrations 3, 5, 10, 20 and 50 ml/l on nine selected species of moulds were tested. Lactic and oxalic acids did not prove the satisfactory fungicidal activity in any of the chosen concentrations. The antifungal effect of the other three acids, manifested by the growth inhibition of the tested moulds is shown in Tab. I and it can be expressed by sequence: propionic acid, formic acid, and acetic acid. These acids also had effects only in concentrations 20 ml/l and 50 ml/l. Propionic acid in concentration 20 ml/l inhibited the growth of five moulds (Penicillium glabrum, Aspergillus niger, Fusarium moniliforme, Aspergillus fumigatus, Cladosporium sphaerospermum). In testing of concentration 50 ml/l, the lower fungicidal ability was ascertained only in growth suppression of Aspergillus flavus. The fungicidal activity of formic acid was registered in concentration 20 ml/l in two cases and in concentration 50 ml/l in six cases. Acetic acid inhibited the growth in concentration 50 ml/l only in two cases. Tab. II shows the percentual evaluation of propionic acid and formic acid with regard to their inhibition abilities. The fungicidal efficiency of propionic acid resulting from the experiment is 88.9%. PMID:8122343

  5. Interaction of aromatic alcohols, aldehydes and acids with α-hydroxyl-containing carbon-centered radicals: A steady state radiolysis study

    NASA Astrophysics Data System (ADS)

    Samovich, S. N.; Brinkevich, S. D.; Shadyro, O. I.

    2013-01-01

    Benzaldehyde and its derivatives efficaciously oxidize in aqueous solutions α-hydroxyl-containing carbon-centered radicals (α-HCR) of various structures, suppressing thereby the radical recombination and fragmentation reactions. The compounds containing cinnamic moieties are capable of adding α-hydroxyethyl radicals (α-HER) to the carbon-carbon double bonds conjugated with the aromatic system to form molecular products identifiable by mass spectrometry. On radiolysis of aqueous ethanol solutions, reduction of α-HER by aromatic alcohols and acids has been shown to proceed via formation of their adducts with hydrated electron species.

  6. Aldehydes: occurrence, carcinogenic potential, mechanism of action and risk assessment.

    PubMed

    Feron, V J; Til, H P; de Vrijer, F; Woutersen, R A; Cassee, F R; van Bladeren, P J

    1991-01-01

    Aldehydes constitute a group of relatively reactive organic compounds. They occur as natural (flavoring) constituents in a wide variety of foods and food components, often in relatively small, but occasionally in very large concentrations, and are also widely used as food additives. Evidence of carcinogenic potential in experimental animals is convincing for formaldehyde and acetaldehyde, limited for crotonaldehyde, furfural and glycidaldehyde, doubtful for malondialdehyde, very weak for acrolein and absent for vanillin. Formaldehyde carcinogenesis is a high-dose phenomenon in which the cytotoxicity plays a crucial role. Cytotoxicity may also be of major importance in acetaldehyde carcinogenesis but further studies are needed to prove or disprove this assumption. For a large number of aldehydes (relevant) data on neither carcinogenicity nor genotoxicity are available. From epidemiological studies there is no convincing evidence of aldehyde exposure being related to cancer in humans. Overall assessment of the cancer risk of aldehydes in the diet leads to the conclusion that formaldehyde, acrolein, citral and vanillin are no dietary risk factors, and that the opposite may be true for acetaldehyde, crotonaldehyde and furfural. Malondialdehyde, glycidaldehyde, benzaldehyde, cinnamaldehyde and anisaldehyde cannot be evaluated on the basis of the available data. A series of aldehydes should be subjected to at least mutagenicity, cytogenicity and cytotoxicity tests. Priority setting for testing should be based on expected mechanism of action and degree of human exposure. PMID:2017217

  7. Organic Acids Over Equatorial Africa: Results from DECAFE 88

    NASA Astrophysics Data System (ADS)

    Helas, Günter; Bingemer, Heinz; Andreae, Meinrat O.

    1992-04-01

    Gaseous short chain organic acids were measured during the dry season (February) in and above the rain forest of the northern Congo. Samples were taken at ground level and during several flights up to 4 km altitude. The organic acids were concentrated from the atmosphere by using "mist scrubbers," which expose a mist of deionized water to the air to be probed. The organic acids absorbed in the water were subsequently analyzed by ion chromatography. Formic, acetic, and pyruvic acids were identified in the samples. At ground level, average mixing ratios of gaseous formic and acetic acid of 0.5±0.6 and 0.6±0.7 parts per billion by volume (ppbv) (1 s), respectively, were found. Boundary layer mixing ratios, however, were significantly higher (3.7±1.0 and 2.7±0.9 ppbv). This indicates a downward net flux of these atmospheric trace components from the boundary layer to the surface. Free tropospheric samples taken above the cloud convection layer show lower mixing ratios again (0.9±0.3 and 0.7±0.1 ppbv). On the basis of this vertical distribution, direct emission by vegetation is not considered to be the dominant source. Biomass burning and photochemical oxidation of biogenic precursors are the major processes contributing to the enhancement of organic acids observed in the boundary layer. The organic acids parallel the profiles of ozone and CO, which suggests that their generation processes are closely related. Pyruvic acid is not correlated with formic acid, indicating that the oxidation of isoprene is not of major importance. In emissions from biomass fires, CO correlates well with formic and acetic acid, and thus some of the enhancement of organic acids in the boundary layer can be explained due to burning. However, an additional gas phase source for organic acids must exist to explain the observed ratio of formic to acetic acid. This is most likely the ozonolysis of olefins which were released as pyrolysis products from biomass burning.

  8. A single aldehyde group can serve as a structural element for recognition by transmembrane protein CD36.

    PubMed

    Tsuzuki, Satoshi; Amitsuka, Takahiko; Okahashi, Tatsuya; Kozai, Yuki; Matsumura, Shigenobu; Inoue, Kazuo; Fushiki, Tohru

    2016-07-01

    Transmembrane protein CD36 is considered to bind its distinct ligands such as long-chain fatty acids primarily by recognizing their terminal carboxyl moiety. In this study, we provide evidence that long-chain fatty aldehydes, such as oleic aldehyde, can be recognized by CD36. We suggest that a single aldehyde group may also serve as one of the structural elements recognizable by CD36. PMID:26923548

  9. Aldehyde dehydrogenases: From eye crystallins to metabolic disease and cancer stem cells

    PubMed Central

    Vasiliou, Vasilis; Thompson, David C.; Smith, Clay; Fujita, Mayumi; Chen, Ying

    2014-01-01

    The aldehyde dehydrogenase (ALDH) superfamily is composed of nicotinamide adenine dinucleotide (phosphate) (NAD(P)+)-dependent enzymes that catalyze the oxidation of aldehydes to their corresponding carboxylic acids. To date, 24 ALDH gene families have been identified in the eukaryotic genome. In addition to aldehyde metabolizing capacity, ALDHs have additional catalytic (e.g. esterase and reductase) and non-catalytic activities. The latter include functioning as structural elements in the eye (crystallins) and as binding molecules to endobiotics and xenobiotics. Mutations in human ALDH genes and subsequent inborn errors in aldehyde metabolism are the molecular basis of several diseases. Most recently ALDH polymorphisms have been associated with gout and osteoporosis. Aldehyde dehydrogenase enzymes also play important roles in embryogenesis and development, neurotransmission, oxidative stress and cancer. This article serves as a comprehensive review of the current state of knowledge regarding the ALDH superfamily and the contribution of ALDHs to various physiological and pathophysiological processes. PMID:23159885

  10. The Roles of Organic Acids in C4 Photosynthesis

    PubMed Central

    Ludwig, Martha

    2016-01-01

    Organic acids are involved in numerous metabolic pathways in all plants. The finding that some plants, known as C4 plants, have four-carbon dicarboxylic acids as the first product of carbon fixation showed these organic acids play essential roles as photosynthetic intermediates. Oxaloacetate (OAA), malate, and aspartate (Asp) are substrates for the C4 acid cycle that underpins the CO2 concentrating mechanism of C4 photosynthesis. In this cycle, OAA is the immediate, short-lived, product of the initial CO2 fixation step in C4 leaf mesophyll cells. The malate and Asp, resulting from the rapid conversion of OAA, are the organic acids delivered to the sites of carbon reduction in the bundle-sheath cells of the leaf, where they are decarboxylated, with the released CO2 used to make carbohydrates. The three-carbon organic acids resulting from the decarboxylation reactions are returned to the mesophyll cells where they are used to regenerate the CO2 acceptor pool. NADP-malic enzyme-type, NAD-malic enzyme-type, and phosphoenolpyruvate carboxykinase-type C4 plants were identified, based on the most abundant decarboxylating enzyme in the leaf tissue. The genes encoding these C4 pathway-associated decarboxylases were co-opted from ancestral C3 plant genes during the evolution of C4 photosynthesis. Malate was recognized as the major organic acid transferred in NADP-malic enzyme-type C4 species, while Asp fills this role in NAD-malic enzyme-type and phosphoenolpyruvate carboxykinase-type plants. However, accumulating evidence indicates that many C4 plants use a combination of organic acids and decarboxylases during CO2 fixation, and the C4-type categories are not rigid. The ability to transfer multiple organic acid species and utilize different decarboxylases has been suggested to give C4 plants advantages in changing and stressful environments, as well as during development, by facilitating the balance of energy between the two cell types involved in the C4 pathway of CO2

  11. The Roles of Organic Acids in C4 Photosynthesis.

    PubMed

    Ludwig, Martha

    2016-01-01

    Organic acids are involved in numerous metabolic pathways in all plants. The finding that some plants, known as C4 plants, have four-carbon dicarboxylic acids as the first product of carbon fixation showed these organic acids play essential roles as photosynthetic intermediates. Oxaloacetate (OAA), malate, and aspartate (Asp) are substrates for the C4 acid cycle that underpins the CO2 concentrating mechanism of C4 photosynthesis. In this cycle, OAA is the immediate, short-lived, product of the initial CO2 fixation step in C4 leaf mesophyll cells. The malate and Asp, resulting from the rapid conversion of OAA, are the organic acids delivered to the sites of carbon reduction in the bundle-sheath cells of the leaf, where they are decarboxylated, with the released CO2 used to make carbohydrates. The three-carbon organic acids resulting from the decarboxylation reactions are returned to the mesophyll cells where they are used to regenerate the CO2 acceptor pool. NADP-malic enzyme-type, NAD-malic enzyme-type, and phosphoenolpyruvate carboxykinase-type C4 plants were identified, based on the most abundant decarboxylating enzyme in the leaf tissue. The genes encoding these C4 pathway-associated decarboxylases were co-opted from ancestral C3 plant genes during the evolution of C4 photosynthesis. Malate was recognized as the major organic acid transferred in NADP-malic enzyme-type C4 species, while Asp fills this role in NAD-malic enzyme-type and phosphoenolpyruvate carboxykinase-type plants. However, accumulating evidence indicates that many C4 plants use a combination of organic acids and decarboxylases during CO2 fixation, and the C4-type categories are not rigid. The ability to transfer multiple organic acid species and utilize different decarboxylases has been suggested to give C4 plants advantages in changing and stressful environments, as well as during development, by facilitating the balance of energy between the two cell types involved in the C4 pathway of CO2

  12. Abscisic acid and aldehyde oxidase activity in maize ear leaf and grain relative to post-flowering photosynthetic capacity and grain-filling rate under different water/nitrogen treatments.

    PubMed

    Qin, Shujun; Zhang, Zongzheng; Ning, Tangyuan; Ren, Shizhong; Su, Licheng; Li, Zengjia

    2013-09-01

    This study investigated changes in leaf abscisic acid (ABA) concentrations and grain ABA concentrations in two maize cultivars and analyzed the following relationships under different water/nitrogen treatments: leaf ABA concentrations and photosynthetic parameters; leaf ABA concentrations and grain ABA concentrations; leaf/grain ABA concentrations and grain-filling parameters; and aldehyde oxidase (AO, EC 1.2.3.1) activities and ABA concentrations. The ear leaf average AO activities and ABA concentrations were lower in the controlled release urea treatments compared with the conventional urea treatments. The average AO activities in the grains were higher in the controlled release urea treatments, and the ABA concentrations were significantly increased at 11-30 DAF. The Pn and ABA concentrations in ear leaves were negatively correlated. And the Gmean were positively correlated with the grain ABA concentrations at 11-30 DAF and negatively correlated with the leaf ABA concentrations at 20 and 40-50 DAF. The grain ABA concentrations and leaf ABA concentrations were positively correlated. Thus, the Gmean were closely related to the AO activities and to the ear leaf and grain ABA concentrations. As compared to other treatments, the subsoiling and controlled release urea treatment promoted the uptake of water and nitrogen by maize, increased the photosynthetic capacity of the ear leaves, increased the grain-filling rate, and improved the movement of photosynthetic assimilates toward the developing grains. In the cultivar Z958, higher ABA concentrations in grains at 11-30 DAF and lower ABA concentrations in ear leaves during the late grain-filling stage, resulted in higher grain-filling rate and increased accumulation of photosynthetic products (relative to the cultivar D3). PMID:23770596

  13. Hydrothermal Mineral-Assisted Organic Transformations of Carboxylic Acids

    NASA Astrophysics Data System (ADS)

    Johnson, K. N.; Gould, I.; Williams, L. B.; Hartnett, H. E.; Shock, E.

    2014-12-01

    The purpose of our research is to probe the varieties of reactions possible in a hydrothermal system in which both organic compounds and minerals interact. We performed experiments at physical conditions representative of deep-sea and subsurface systems (300°C and 1000 bar) and analyzed the effect of the mineral magnetite (Fe3O4) in systems with carboxylic acids, either phenylacetic acid or hydrocinnamic acid (a.k.a., phenylpropanoic acid). Control experiments were also conducted with the same organic compounds in the absence of magnetite. Whereas previous studies of carboxylic acid reactivity with minerals have focused exclusively on simple molecules such as acetic acid and valeric acid (Bell et al. 1994; McCollom et al. 2003), the carboxylic acids used in our study differ from previous experimental compounds by the addition of a phenyl ring, which allows for the investigation of the specific mechanistic pathways of product formation. Decarboxylation (i.e., RCO2H → RH + CO2) is one of the major reaction pathways for carboxylic acids in hydrothermal conditions without minerals. Under our experimental conditions, decarboxylation leads to the ~80% conversion of phenylacetic acid into toluene within ~50 hours and the ~8% conversion of hydrocinnamic acid to ethyl benzene within ~190 hours. We found that magnetite had a different effect on the two organic compounds studied. In experiments with phenylacetic acid, the presence of magnetite did not enhance the rate of toluene production from decarboxylation but did activate additional product pathways that include diphenyl alkanes, alkenes, and ketones, as well as benzoic acid, a carboxylic acid one carbon length shorter than the parent compound. Magnetite had even more noticeable effects on the hydrocinnamic acid system leading to an increase of its consumption at 190 hours from ~9% in magnetite's absence to ~35% in the mineral's presence. Products of the experiments with magnetite included an enhanced rate of

  14. Organic acid contents in onion cultivars (Allium cepa L.).

    PubMed

    Rodríguez Galdón, Beatriz; Tascón Rodríguez, Catalina; Rodríguez Rodríguez, Elena; Díaz Romero, Carlos

    2008-08-13

    The following organic acids (glutamic, oxalic, pyruvic, malic, tartaric, citric, and fumaric), pungency, Brix degree, acidity, and pH were determined in onion cultivars (Texas, Guayonje, San Juan de la Rambla, Carrizal Alto, Carrizal Bajo, and Masca) harvested in the same agroclimatic conditions. Glutamic acid was the most abundant organic acid (325 +/- 133 mg/100 g) followed by citric acid (48.5 +/- 24.1 mg/100 g) and malic acid (43.6 +/- 10.4 mg/100 g). There were significant differences between the onion cultivars in the mean concentrations of all of the analyzed parameters. The San Juan de la Rambla and Masca cultivars presented, in general, higher concentrations of the organic acids than the other cultivars. Significant differences in most of the analyzed parameters were observed between the two seed origins for the Masca and San Juan de la Rambla cultivars. The onion samples tended to be classified according to the cultivar and, in the case of San Juan de la Rambla cultivar, according to the precedence of the seeds after applying discriminant analysis. PMID:18616262

  15. Real World of Industrial Chemistry: Organic Chemicals from Carbon Monoxide.

    ERIC Educational Resources Information Center

    Kolb, Kenneth E.; Kolb, Doris

    1983-01-01

    Carbon Monoxide obtained from coal may serve as the source for a wide variety of organic compounds. Several of these compounds are discussed, including phosgene, benzaldehyde, methanol, formic acid and its derivatives, oxo aldehydes, acrylic acids, and others. Commercial reactions of carbon monoxide are highlighted in a table. (JN)

  16. Organic acids emissions from natural-gas-fed engines

    NASA Astrophysics Data System (ADS)

    Zervas, Efthimios; Tazerout, Mohand

    A natural-gas-fed spark-ignition engine, operating under lean conditions, is used for the study of the organic acids exhaust emissions. These pollutants are collected by passing a sample of exhaust gas into deionised water. The final solution is directly analysed by HPLC/UV at 204 nm. Only formic acid is emitted in detectable concentration under the experimental conditions used. Its concentration decreases with the three engine operating parameters studied: spark advance, volumetric efficiency and fuel/air equivalence ratio. Exhaust formic acid concentration is also linked with exhaust oxygen concentration and exhaust temperature. A comparison with other engines (SI engines fed with gasoline and compression ignition engines) from bibliographic data proves that natural-gas-fed engines emit less organic acids than the other two types of engines.

  17. Metabolic engineering in the biotechnological production of organic acids in the tricarboxylic acid cycle of microorganisms: Advances and prospects.

    PubMed

    Yin, Xian; Li, Jianghua; Shin, Hyun-Dong; Du, Guocheng; Liu, Long; Chen, Jian

    2015-11-01

    Organic acids, which are chemically synthesized, are also natural intermediates in the metabolic pathways of microorganisms, among which the tricarboxylic acid (TCA) cycle is the most crucial route existing in almost all living organisms. Organic acids in the TCA cycle include citric acid, α-ketoglutaric acid, succinic acid, fumaric acid, l-malic acid, and oxaloacetate, which are building-block chemicals with wide applications and huge markets. In this review, we summarize the synthesis pathways of these organic acids and review recent advances in metabolic engineering strategies that enhance organic acid production. We also propose further improvements for the production of organic acids with systems and synthetic biology-guided metabolic engineering strategies. PMID:25902192

  18. Using organic acids to diagnose and manage recalcitrant patients.

    PubMed

    Rogers, Sherry A

    2006-01-01

    "Organic acids" refers to a broad class of compounds used in fundamental metabolic processes of the body. They provide valuable clues about functional nutrient deficiencies, mitochondrial energy production, intestinal dysbiosis, free radical overload, and more, including where to start when diagnosing a patient with complicated symptoms. Organic acids present a whole new exciting world of therapeutic options. They are one of the tools that enable us to identify and correct the underlying causes of disease, and not merely temporarily suppress symptoms with pharmaceuticals. The sicker the patient, the more they need this intervention: half the patients in intensive care units were found to be nutrient-deficient in studies that look at only 1 or a few of the many nutrients. Studies show that a patient's outcome is more dismal and his chances of dying are greater as undiagnosed nutrient deficiencies mount. Furthermore, studies confirm that giving pennies' worth of antioxidants to patients in intensive care can cut the death rate in half. What drug can accomplish this, much less for pennies a day? Doesn't it make more sense to individually determine the patients' deficiencies and correct them? Combined with companion tests of intracellular minerals, toxic elements (heavy metals), fatty acids, vitamins, and amino acids, organic acids testing can clearly indicate health challenges the patient will face in the future. In many cases, they are correctable and curable. This article explored only 5 categories of organic acids out of more than 9 and 29 organic acids out of more than 47. For physicians who want more information, there are several resources available. This knowledge, along with biochemical knowledge and patient experience, can further empower physicians to help truly heal their patients. PMID:16862742

  19. ENVIRONMENTAL TECHNOLOGY PROTOCOL VERIFICATION REPORT, EMISSIONS OF VOCS AND ALDEHYDES FROM COMMERCIAL FURNITURE (WITH APPENDICES)

    EPA Science Inventory

    As part of a U.S. Environmental Protection Agency Environmental Technology Verification program, the Research Triangle Institute (RTI) developed a test protocol for measuring volatile organic compounds and aldehydes in a large chamber. RTI convened stakeholders for the commercial...

  20. Bio-based production of organic acids with Corynebacterium glutamicum.

    PubMed

    Wieschalka, Stefan; Blombach, Bastian; Bott, Michael; Eikmanns, Bernhard J

    2013-03-01

    The shortage of oil resources, the steadily rising oil prices and the impact of its use on the environment evokes an increasing political, industrial and technical interest for development of safe and efficient processes for the production of chemicals from renewable biomass. Thus, microbial fermentation of renewable feedstocks found its way in white biotechnology, complementing more and more traditional crude oil-based chemical processes. Rational strain design of appropriate microorganisms has become possible due to steadily increasing knowledge on metabolism and pathway regulation of industrially relevant organisms and, aside from process engineering and optimization, has an outstanding impact on improving the performance of such hosts. Corynebacterium glutamicum is well known as workhorse for the industrial production of numerous amino acids. However, recent studies also explored the usefulness of this organism for the production of several organic acids and great efforts have been made for improvement of the performance. This review summarizes the current knowledge and recent achievements on metabolic engineering approaches to tailor C. glutamicum for the bio-based production of organic acids. We focus here on the fermentative production of pyruvate, L- and D-lactate, 2-ketoisovalerate, 2-ketoglutarate, and succinate. These organic acids represent a class of compounds with manifold application ranges, e.g. in pharmaceutical and cosmetics industry, as food additives, and economically very interesting, as precursors for a variety of bulk chemicals and commercially important polymers. PMID:23199277

  1. Molecular controls on kaolinite surface charge and organic acid adsorption

    SciTech Connect

    Brady, P.V.; Cygan, R.T.; Nagy, K.L.; Ward, D.B.

    1996-10-01

    pH-dependent multi-site kaolinite surface charge can be explained by proton donor-acceptor reactions occurring simultaneously on Si and Al sites exposed on edge sites. Si site acidity at the kaolinite-solution interface differs minimally from that of pure SiO{sub 2}, whereas Al sites became appreciably more acidic when a part of the kaolinite matrix. Independent evidence from scanning force microscopy points to a higher percentage of edge surface area due to thicker particles and basal surface steps than previously assumed. Molecular modeling of the proton-relaxed kaolinite structure has been used to establish the elevated acidity of edge Al sites, to independently confirm the crystallochemical controls on surface acidity, and to establish likely bonding geometries for adsorbed organic acids, such as oxalate.

  2. Structure of seven organic salts assembled from 2,6-diaminopyridine with monocarboxylic acids, dicarboxylic acids, and tetracarboxylic acids

    NASA Astrophysics Data System (ADS)

    Gao, Xingjun; Zhang, Huan; Wen, Xianhong; Liu, Bin; Jin, Shouwen; Wang, Daqi

    2015-08-01

    Studies concentrating on non-covalent interactions between the organic base of 2,6-diaminopyridine, and carboxylic acids have led to an increased understanding of the role 2,6-diaminopyridine in binding with carboxylic acid derivatives. Here anhydrous and hydrated multi-component organic acid-base salts of 2,6-diaminopyridine have been prepared with the carboxylic acids as nicotinic acid, o-chlorobenzoic acid, 1,3-benzodioxole-5-carboxylic acid, 3,5-dinitrosalicylic acid, 4-nitro-phthalic acid, 1,4-cyclohexanedicarboxylic acid, and butane-1,2,3,4-tetracarboxylic acid. The seven crystalline compounds were characterized by X-ray diffraction analysis, infrared (IR), melting point (mp), and elemental analysis. All structures adopted the hetero R22(8) supramolecular synthons. The supramolecular architectures bear extensive Nsbnd H⋯N, Osbnd H⋯N, Osbnd H⋯O, Nsbnd H⋯O, and CH⋯O associations as well as other nonbonding contacts as CHsbnd N, CH2sbnd O, π-π, C-π, O-π, Cl-π, Clsbnd O, and Osbnd O interactions. The role of weak and strong hydrogen bonding in the crystal packing is ascertained.

  3. ORGANIC ACIDITY IN MAINE (U.S.A.) LAKES AND IN HUMEX LAKE SKJERVATJERN (NORWAY)

    EPA Science Inventory

    Organic acids, a component of dissolved organic carbon can be a major factor in the acidity of many lakes and streams. n order to evaluate the importance of organic acidity, we fractionated (hydrophobic acids and neutrals, hydrophilic acids, bases, and neutrals) and isolated hydr...

  4. Cyanobacterial aldehyde deformylase oxygenation of aldehydes yields n-1 aldehydes and alcohols in addition to alkanes

    PubMed Central

    Aukema, Kelly G.; Makris, Thomas M.; Stoian, Sebastian A.; Richman, Jack E.; Münck, Eckard; Lipscomb, John D.; Wackett, Lawrence P.

    2013-01-01

    Aldehyde-deformylating oxygenase (ADO) catalyzes O2-dependent release of the terminal carbon of a biological substrate, octadecanal, to yield formate and heptadecane in a reaction that requires external reducing equivalents. We show here that ADO also catalyzes incorporation of an oxygen atom from O2 into the alkane product to yield alcohol and aldehyde products. Oxygenation of the alkane product is much more pronounced with C9-10 aldehyde substrates, so that use of nonanal as the substrate yields similar amounts of octane, octanal, and octanol products. When using doubly-labeled [1,2-13C]-octanal as the substrate, the heptane, heptanal and heptanol products each contained a single 13C-label in the C-1 carbons atoms. The only one-carbon product identified was formate. [18O]-O2 incorporation studies demonstrated formation of [18O]-alcohol product, but rapid solvent exchange prevented similar determination for the aldehyde product. Addition of [1-13C]-nonanol with decanal as the substrate at the outset of the reaction resulted in formation of [1-13C]-nonanal. No 13C-product was formed in the absence of decanal. ADO contains an oxygen-bridged dinuclear iron cluster. The observation of alcohol and aldehyde products derived from the initially formed alkane product suggests a reactive species similar to that formed by methane monooxygenase (MMO) and other members of the bacterial multicomponent monooxygenase family. Accordingly, characterization by EPR and Mössbauer spectroscopies shows that the electronic structure of the ADO cluster is similar, but not identical, to that of MMO hydroxylase component. In particular, the two irons of ADO reside in nearly identical environments in both the oxidized and fully reduced states, whereas those of MMOH show distinct differences. These favorable characteristics of the iron sites allow a comprehensive determination of the spin Hamiltonian parameters describing the electronic state of the diferrous cluster for the first time for

  5. Interaction of aldehydes derived from lipid peroxidation and membrane proteins

    PubMed Central

    Pizzimenti, Stefania; Ciamporcero, Eric; Daga, Martina; Pettazzoni, Piergiorgio; Arcaro, Alessia; Cetrangolo, Gianpaolo; Minelli, Rosalba; Dianzani, Chiara; Lepore, Alessio; Gentile, Fabrizio; Barrera, Giuseppina

    2013-01-01

    A great variety of compounds are formed during lipid peroxidation of polyunsaturated fatty acids of membrane phospholipids. Among them, bioactive aldehydes, such as 4-hydroxyalkenals, malondialdehyde (MDA) and acrolein, have received particular attention since they have been considered as toxic messengers that can propagate and amplify oxidative injury. In the 4-hydroxyalkenal class, 4-hydroxy-2-nonenal (HNE) is the most intensively studied aldehyde, in relation not only to its toxic function, but also to its physiological role. Indeed, HNE can be found at low concentrations in human tissues and plasma and participates in the control of biological processes, such as signal transduction, cell proliferation, and differentiation. Moreover, at low doses, HNE exerts an anti-cancer effect, by inhibiting cell proliferation, angiogenesis, cell adhesion and by inducing differentiation and/or apoptosis in various tumor cell lines. It is very likely that a substantial fraction of the effects observed in cellular responses, induced by HNE and related aldehydes, be mediated by their interaction with proteins, resulting in the formation of covalent adducts or in the modulation of their expression and/or activity. In this review we focus on membrane proteins affected by lipid peroxidation-derived aldehydes, under physiological and pathological conditions. PMID:24027536

  6. Fluorescence lifetime analysis and effect of magnesium ions on binding of NADH to human aldehyde dehydrogenase 1

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aldehyde dehydrogenase 1 (ALDH1) catalyzes oxidation of toxic aldehydes to carboxylic acids. Physiologic levels of Mg2+ ions influence ALDH1 activity in part by increasing NADH binding affinity to the enzyme thus reducing activity. By using time-resolved fluorescence spectroscopy, we have resolved t...

  7. Acid rain effects on aluminum mobilization clarified by inclusion of strong organic acids

    USGS Publications Warehouse

    Lawrence, G.B.; Sutherland, J.W.; Boylen, C.W.; Nierzwicki-Bauer, S. W.; Momen, B.; Baldigo, Barry P.; Simonin, H.A.

    2007-01-01

    Assessments of acidic deposition effects on aquatic ecosystems have often been hindered by complications from naturally occurring organic acidity. Measurements of pH and ANCG, the most commonly used indicators of chemical effects, can be substantially influenced by the presence of organic acids. Relationships between pH and inorganic Al, which is toxic to many forms of aquatic biota, are also altered by organic acids. However, when inorganic Al concentrations are plotted against ANC (the sum of Ca2+, Mg 2+, Na+, and K+, minus SO42-, NO3-, and Cl-), a distinct threshold for Al mobilization becomes apparent. If the concentration of strong organic anions is included as a negative component of ANC, the threshold occurs at an ANC value of approximately zero, the value expected from theoretical charge balance constraints. This adjusted ANC is termed the base-cation surplus. The threshold relationship between the base-cation surplus and Al was shown with data from approximately 200 streams in the Adirondack region of New York, during periods with low and high dissolved organic carbon concentrations, and for an additional stream from the Catskill region of New York. These results indicate that (1) strong organic anions can contribute to the mobilization of inorganic Al in combination with SO42- and NO 3-, and (2) the presence of inorganic Al in surface waters is an unambiguous indication of acidic deposition effects. ?? 2007 American Chemical Society.

  8. Process for producing furan from furfural aldehyde

    DOEpatents

    Diebold, James P.; Evans, Robert J.

    1988-01-01

    A process of producing furan and derivatives thereof is disclosed. The process includes generating furfural aldehyde vapors and then passing those vapors over a zeolite catalyst at a temperature and for a residence time effective to decarbonylate the furfural aldehydes to form furans and derivatives thereof. The resultant furan vapors and derivatives are then separated. In a preferred form, the furfural aldehyde vapors are generated during the process of converting biomass materials to liquid and gaseous fuels.

  9. Process for producing furan from furfural aldehyde

    DOEpatents

    Diebold, J.P.; Evans, R.J.

    1987-04-06

    A process of producing furan and derivatives thereof as disclosed. The process includes generating furfural aldehyde vapors and then passing those vapors over a zeolite catalyst at a temperature and for a residence time effective to decarbonylate the furfural aldehydes to form furans and derivatives thereof. The resultant furan vapors and derivatives are then separated. In a preferred form, the furfural aldehyde vapors are generated during the process of converting biomass materials to liquid and gaseous fuels.

  10. Formation of Organic Tracers for Isoprene SOA under Acidic Conditions

    EPA Science Inventory

    The chemical compositions of a series of secondary organic aerosol (SOA) samples, formed by irradiating mixtures of isoprene and NO in a smog chamber in the absence or presence of acidic aerosols, were analyzed using derivatization-based GC-MS methods. In addition to the known is...

  11. Variability for free sugars and organic acids in Capsicum Chinense

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fruit of 216 genotypes of Capsicum chinense Jacq. were analyzed for concentrations of the simple sugars sucrose, glucose, fructose, and the organic acids; citric, malic, succinic, fumaric and ascorbic. Concentrations [mg/100g Fresh Weight (FW) of whole fruit] of sucrose, glucose and fructose in fru...

  12. SOURCES OF ORGANIC ACIDS IN INDOOR AIR: A FIELD STUDY

    EPA Science Inventory

    Simultaneous indoor and outdoor measurements of organic acids were made at six residential houses located in suburban New Jersey area during the summer of 1992. ach house was measured for six days and controlled for ventilation and gas combustion conditions. he study presents the...

  13. Amylase activity of Aspergillus strains--producers of organic acids.

    PubMed

    Tsekova, K; Dentchev, D; Vicheva, A; Dekovska, M

    1993-01-01

    The ability of fungi from genus Aspergillus (producers of organic acids) to synthesize amylase enzymes (alpha-amylase and glucoamylase) was investigated. The productivity of the strains on Czapek-Dox agar and in liquid Czapec-Dox media with 3% soluble starch as a carbon source was established. PMID:8285132

  14. A New Approach to Non-Coordinating Anions: Lewis Acid Enhancement of Porphyrin Metal Centers in a Zwitterionic Metal-Organic Framework.

    PubMed

    Johnson, Jacob A; Petersen, Brenna M; Kormos, Attila; Echeverría, Elena; Chen, Yu-Sheng; Zhang, Jian

    2016-08-17

    We describe a new strategy to generate non-coordinating anions using zwitterionic metal-organic frameworks (MOFs). By assembly of anionic inorganic secondary building blocks (SBUs) ([In(CO2)4](-)) with cationic metalloporphyrin-based organic linkers, we prepared zwitterionic MOFs in which the complete internal charge separation effectively prevents the potential binding of the counteranion to the cationic metal center. We demonstrate the enhanced Lewis acidity of Mn(III)- and Fe(III)-porphyrins in the zwitterionic MOFs in three representative electrocyclization reactions: [2 + 1] cycloisomerization of enynes, [3 + 2] cycloaddition of aziridines and alkenes, and [4 + 2] hetero-Diels-Alder cycloaddition of aldehydes with dienes. This work paves a new way to design functional MOFs for tunable chemical catalysis. PMID:27435751

  15. Chromate reduction by rabbit liver aldehyde oxidase

    SciTech Connect

    Banks, R.B.; Cooke, R.T. Jr.

    1986-05-29

    Chromate was reduced during the oxidation of 1-methylnicotinamide chlorine by partially purified rabbit liver aldehyde oxidase. In addition to l-methylnicotinamide, several other electron donor substrates for aldehyde oxidase were able to support the enzymatic chromate reduction. The reduction required the presence of both enzyme and the electron donor substrate. The rate of the chromate reduction was retarded by inhibitors or aldehyde oxidase but was not affected by substrates or inhibitors of xanthine oxidase. These results are consistent with the involvement of aldehyde oxidase in the reduction of chromate by rabbit liver cytosolic enzyme preparations.

  16. The abiotic degradation of soil organic matter to oxalic acid

    NASA Astrophysics Data System (ADS)

    Studenroth, Sabine; Huber, Stefan; Schöler, H. F.

    2010-05-01

    The abiotic degradation of soil organic matter to volatile organic compounds was studied intensely over the last years (Keppler et al., 2000; Huber et al., 2009). It was shown that soil organic matter is oxidised due to the presence of iron (III), hydrogen peroxide and chloride and thereby produces diverse alkyl halides, which are emitted into the atmosphere. The formation of polar halogenated compounds like chlorinated acetic acids which are relevant toxic environmental substances was also found in soils and sediments (Kilian et al., 2002). The investigation of the formation of other polar halogenated and non-halogenated compounds like diverse mono- and dicarboxylic acids is going to attain more and more importance. Due to its high acidity oxalic acid might have impacts on the environment e.g., nutrient leaching, plant diseases and negative influence on microbial growth. In this study, the abiotic formation of oxalic acid in soil is examined. For a better understanding of natural degradation processes mechanistic studies were conducted using the model compound catechol as representative for structural elements of the humic substances and its reaction with iron (III) and hydrogen peroxide. Iron is one of the most abundant elements on earth and hydrogen peroxide is produced by bacteria or through incomplete reduction of oxygen. To find suitable parameters for an optimal reaction and a qualitative and quantitative analysis method the following reaction parameters are varied: concentration of iron (III) and hydrogen peroxide, time dependence, pH-value and influence of chloride. Analysis of oxalic acid was performed employing an ion chromatograph equipped with a conductivity detector. The time dependent reaction shows a relatively fast formation of oxalic acid, the optimum yield is achieved after 60 minutes. Compared to the concentration of catechol an excess of hydrogen peroxide as well as a low concentration of iron (III) are required. In absence of chloride the

  17. Nickel-Catalyzed Coupling of Alkenes, Aldehydes, and Silyl Triflates

    PubMed Central

    Ng, Sze-sze; Ho, Chun-Yu; Jamison, Timothy F.

    2011-01-01

    A full account of two recently developed nickel-catalyzed coupling reactions of alkenes, aldehydes and silyl triflates is presented. These reactions provide either allylic alcohol or homoallylic alcohol derivatives selectively, depending on the ligand employed. These processes are believed to be mechanistically distinct from Lewis acid-catalyzed carbonyl-ene reactions, and several lines of evidence supporting this hypothesis are discussed. PMID:16939275

  18. DIFFERENTIATING THE TOXICITY OF CARCINOGENIC ALDEHYDES FROM NONCARCINOGENIC ALDEHYDES IN THE RAT NOSE USING CDNA ARRAYS

    EPA Science Inventory

    Differentiating the Toxicity of Carcinogenic Aldehydes from Noncarcinogenic Aldehydes in the Rat Nose Using cDNA Arrays.

    Formaldehyde is a widely used aldehyde in many industrial settings, the tanning process, household products, and is a contaminant in cigarette smoke. H...

  19. Acyloin production from aldehydes in the perfused rat heart: the potential role of pyruvate dehydrogenase.

    PubMed Central

    Montgomery, J A; Jetté, M; Huot, S; Des Rosiers, C

    1993-01-01

    Aldehydes represent an important class of cytotoxic products derived from free radical-induced lipid peroxidation which may contribute to reperfusion injury following myocardial infarct. Metabolism of aldehydes in the heart has not been well characterized aside from conjugation of unsaturated aldehydes with glutathione. However, aliphatic aldehydes like hexanal do not form stable glutathione conjugates. We have recently demonstrated in vitro that pig heart pyruvate dehydrogenase catalyses a reaction between pyruvate and saturated aldehydes to produce acyloins (3-hydroxyalkan-2-ones). In the present study, rat hearts were perfused with various aldehydes and pyruvate. Acyloins were generated from saturated aldehydes (butanal, hexanal or nonanal), but not from 2-hexanal (an unsaturated aldehyde) or malondialdehyde. Hearts perfused with 2 mM pyruvate and 10-100 microM hexanal rapidly took up hexanal in a dose-related manner (140-850 nmol/min), and released 3-hydroxyoctan-2-one (0.7-30 nmol/min), 2,3-octanediol (0-12 nmol/min) and hexanol (10-200 nmol/min). Small quantities of hexanoic acid (about 10 nmol/min) were also released. The rate of release of acyloin metabolites rose with increased concentration of hexanal, whereas hexanol release attained a plateau when hexanal infusion concentrations rose above 50 microM. Up to 50% of hexanal uptake could be accounted for by metabolite release. Less than 0.5% of hexanal uptake was found to be bound to acid-precipitable macromolecules. When hearts perfused with 50 microM hexanal and 2 mM pyruvate were subjected to a 15 min ischaemic period, the rates of release of 2,3-octanediol, 3-hydroxyoctan-2-one, hexanol and hexanoate during the reperfusion period were not significantly different from those in the pre-ischaemic period. Our results indicate that saturated aldehydes can be metabolically converted by the heart into stable diffusible compounds. PMID:8379929

  20. Influence of pasture-based feeding systems on fatty acids, organic acids and volatile organic flavour compounds in yoghurt.

    PubMed

    Akbaridoust, Ghazal; Plozza, Tim; Trenerry, V Craige; Wales, William J; Auldist, Martin J; Ajlouni, Said

    2015-08-01

    The influence of different pasture-based feeding systems on fatty acids, organic acids and volatile organic flavour compounds in yoghurt was studied. Pasture is the main source of nutrients for dairy cows in many parts of the world, including southeast Australia. Milk and milk products produced in these systems are known to contain a number of compounds with positive effects on human health. In the current study, 260 cows were fed supplementary grain and forage according to one of 3 different systems; Control (a traditional pasture based diet offered to the cows during milking and in paddock), PMR1 (a partial mixed ration which contained the same supplement as Control but was offered to the cows as a partial mixed ration on a feedpad), PMR 2 (a differently formulated partial mixed ration compared to Control and PMR1 which was offered to the cows on a feedpad). Most of the yoghurt fatty acids were influenced by feeding systems; however, those effects were minor on organic acids. The differences in feeding systems did not lead to the formation of different volatile organic flavour compounds in yoghurt. Yet, it did influence the relative abundance of these components. PMID:26143651

  1. Organic acid modeling and model validation: Workshop summary. Final report

    SciTech Connect

    Sullivan, T.J.; Eilers, J.M.

    1992-08-14

    A workshop was held in Corvallis, Oregon on April 9--10, 1992 at the offices of E&S Environmental Chemistry, Inc. The purpose of this workshop was to initiate research efforts on the entitled ``Incorporation of an organic acid representation into MAGIC (Model of Acidification of Groundwater in Catchments) and testing of the revised model using Independent data sources.`` The workshop was attended by a team of internationally-recognized experts in the fields of surface water acid-bass chemistry, organic acids, and watershed modeling. The rationale for the proposed research is based on the recent comparison between MAGIC model hindcasts and paleolimnological inferences of historical acidification for a set of 33 statistically-selected Adirondack lakes. Agreement between diatom-inferred and MAGIC-hindcast lakewater chemistry in the earlier research had been less than satisfactory. Based on preliminary analyses, it was concluded that incorporation of a reasonable organic acid representation into the version of MAGIC used for hindcasting was the logical next step toward improving model agreement.

  2. Organic acid modeling and model validation: Workshop summary

    SciTech Connect

    Sullivan, T.J.; Eilers, J.M.

    1992-08-14

    A workshop was held in Corvallis, Oregon on April 9--10, 1992 at the offices of E S Environmental Chemistry, Inc. The purpose of this workshop was to initiate research efforts on the entitled Incorporation of an organic acid representation into MAGIC (Model of Acidification of Groundwater in Catchments) and testing of the revised model using Independent data sources.'' The workshop was attended by a team of internationally-recognized experts in the fields of surface water acid-bass chemistry, organic acids, and watershed modeling. The rationale for the proposed research is based on the recent comparison between MAGIC model hindcasts and paleolimnological inferences of historical acidification for a set of 33 statistically-selected Adirondack lakes. Agreement between diatom-inferred and MAGIC-hindcast lakewater chemistry in the earlier research had been less than satisfactory. Based on preliminary analyses, it was concluded that incorporation of a reasonable organic acid representation into the version of MAGIC used for hindcasting was the logical next step toward improving model agreement.

  3. Accurate determination of aldehydes in amine catalysts or amines by 2,4-dinitrophenylhydrazine derivatization.

    PubMed

    Barman, Bhajendra N

    2014-01-31

    Carbonyl compounds, specifically aldehydes, present in amine catalysts or amines are determined by reversed-phase liquid chromatography using ultraviolet detection of their corresponding 2,4-dinitrophenylhydrazones. The primary focus has been to establish optimum conditions for determining aldehydes accurately because these add exposure concerns when the amine catalysts are used to manufacture polyurethane products. Concentrations of aldehydes determined by this method are found to vary with the pH of the aqueous amine solution and the derivatization time, the latter being problematic when the derivatization reaction proceeds slowly and not to completion in neutral and basic media. Accurate determination of aldehydes in amines through derivatization can be carried out at an effective solution pH of about 2 and with derivatization time of 20min. Hydrochloric acid has been used for neutralization of an amine. For complete derivatization, it is essential to protonate all nitrogen atoms in the amine. An approach for the determination of an adequate amount of acid needed for complete derivatization has been described. Several 0.2M buffer solutions varying in pH from 4 to 8 have also been used to make amine solutions for carrying out derivatization of aldehydes. These solutions have effective pHs of 10 or higher and provide much lower aldehyde concentrations compared to their true values. Mechanisms for the formation of 2,4-dinitrophenylhydrazones in both acidic and basic media are discussed. PMID:24411140

  4. Fatty Aldehyde and Fatty Alcohol Metabolism: Review and Importance for Epidermal Structure and Function

    PubMed Central

    Rizzo, William B.

    2014-01-01

    Normal fatty aldehyde and alcohol metabolism is essential for epidermal differentiation and function. Long-chain aldehydes are produced by catabolism of several lipids including fatty alcohols, sphingolipids, ether glycerolipids, isoprenoid alcohols and certain aliphatic lipids that undergo α- or ω-oxidation. The fatty aldehyde generated by these pathways is chiefly metabolized to fatty acid by fatty aldehyde dehydrogenase (FALDH, alternately known as ALDH3A2), which also functions to oxidize fatty alcohols as a component of the fatty alcohol:NAD oxidoreductase (FAO) enzyme complex. Genetic deficiency of FALDH/FAO in patients with Sjögren-Larsson syndrome (SLS) results in accumulation of fatty aldehydes, fatty alcohols and related lipids (ether glycerolipids, wax esters) in cultured keratinocytes. These biochemical changes are associated with abnormalities in formation of lamellar bodies in the stratum granulosum and impaired delivery of their precursor membranes to the stratum corneum (SC). The defective extracellular SC membranes are responsible for a leaky epidermal water barrier and ichthyosis. Although lamellar bodies appear to be the pathogenic target for abnormal fatty aldehyde/alcohol metabolism in SLS, the precise biochemical mechanisms are yet to be elucidated. Nevertheless, studies in SLS highlight the critical importance of FALDH and normal fatty aldehyde/alcohol metabolism for epidermal function. PMID:24036493

  5. α,β-Unsaturated aldehyde of hyaluronan--Synthesis, analysis and applications.

    PubMed

    Buffa, Radovan; Šedová, Petra; Basarabová, Ivana; Moravcová, Martina; Wolfová, Lucie; Bobula, Tomáš; Velebný, Vladimír

    2015-12-10

    Hyaluronic acid (HA) modified with an aldehyde group (HA-CHO or HA-aldehyde) has been extensively used for various biomedical applications. The main advantage of the aldehyde moieties is the ability to react with a wide range of amino compounds under physiological conditions. Reactions of aldehydes with primary amines in water are reversible and equilibrium is thoroughly shifted towards starting aldehyde and amine. This work presents an unique modification of HA: α,β-unsaturated aldehyde of HA (4,5-anhydro-6(GlcNAc)-oxo HA or ΔHA-CHO), which allows the primary amines to be attached to HA more effectively in comparison to the saturated HA-CHO. Higher hydrolytic stability is caused by the conjugation of imine with an adjacent --C=C-- double bond. Two strategies for the preparation of unsaturated HA-aldehyde were developed and chemical structures were studied in details. Cross-linked materials prepared from this precursor are biocompatible and suitable for applications in drug delivery and regenerative medicine. PMID:26428127

  6. Bio-based production of organic acids with Corynebacterium glutamicum

    PubMed Central

    Wieschalka, Stefan; Blombach, Bastian; Bott, Michael; Eikmanns, Bernhard J

    2013-01-01

    The shortage of oil resources, the steadily rising oil prices and the impact of its use on the environment evokes an increasing political, industrial and technical interest for development of safe and efficient processes for the production of chemicals from renewable biomass. Thus, microbial fermentation of renewable feedstocks found its way in white biotechnology, complementing more and more traditional crude oil-based chemical processes. Rational strain design of appropriate microorganisms has become possible due to steadily increasing knowledge on metabolism and pathway regulation of industrially relevant organisms and, aside from process engineering and optimization, has an outstanding impact on improving the performance of such hosts. Corynebacterium glutamicum is well known as workhorse for the industrial production of numerous amino acids. However, recent studies also explored the usefulness of this organism for the production of several organic acids and great efforts have been made for improvement of the performance. This review summarizes the current knowledge and recent achievements on metabolic engineering approaches to tailor C. glutamicum for the bio-based production of organic acids. We focus here on the fermentative production of pyruvate, l-and d-lactate, 2-ketoisovalerate, 2-ketoglutarate, and succinate. These organic acids represent a class of compounds with manifold application ranges, e.g. in pharmaceutical and cosmetics industry, as food additives, and economically very interesting, as precursors for a variety of bulk chemicals and commercially important polymers. Funding Information Work in the laboratories of the authors was supported by the Fachagentur Nachwachsende Rohstoffe (FNR) of the Bundesministerium für Ernährung, Landwirtschaft und Verbraucherschutz (BMELV; FNR Grants 220-095-08A and 220-095-08D; Bio-ProChemBB project, ERA-IB programme), by the Deutsche Bundesstiftung Umwelt (DBU Grant AZ13040/05) and the Evonik Degussa AG. PMID

  7. Adsorption of chromate/organic-acid mixtures in aquifer materials

    SciTech Connect

    Fish, W.; Palmer, C.D.

    1991-07-15

    The overall objective of this project is to develop a fuller understanding of the interactions of mixtures of anionic co-contaminants with oxide-mineral surfaces. Our specific focus is on the competitive interactions of chromate and oxalic acid on ferric oxyhydroxide and on natural aquifer materials. Chromate and oxalate are of practical interest as widespread contaminants at many DOE facilities. However, these anions also are excellent model adsorbates for elucidating fundamental aspects of ionic adsorption processes, particularly with respect to organic acids.

  8. Various instrumental approaches for determination of organic acids in wines.

    PubMed

    Zeravik, Jiri; Fohlerova, Zdenka; Milovanovic, Miodrag; Kubesa, Ondrej; Zeisbergerova, Marta; Lacina, Karel; Petrovic, Aleksandar; Glatz, Zdenek; Skladal, Petr

    2016-03-01

    Biosensors based on lactate oxidase, sarcosine oxidase and mixture of fumarase and sarcosine oxidase were used for monitoring of organic acids in wine samples. Additionally, tartaric acid was determined by modified colorimetric method based on formation of the vanadate-tartrate complex. The above mentioned methods were used for the analysis of 31 wine samples and obtained data were compared with the results from capillary electrophoresis as a basic standard method. This comparison showed a certain degree of correlation between biosensors and capillary electrophoresis. The provided information pointed to the potential uses of biosensors in the field of winemaking. PMID:26471576

  9. Role of antioxidant enzymes in bacterial resistance to organic acids.

    PubMed

    Bruno-Bárcena, Jose M; Azcárate-Peril, M Andrea; Hassan, Hosni M

    2010-05-01

    Growth in aerobic environments has been shown to generate reactive oxygen species (ROS) and to cause oxidative stress in most organisms. Antioxidant enzymes (i.e., superoxide dismutases and hydroperoxidases) and DNA repair mechanisms provide protection against ROS. Acid stress has been shown to be associated with the induction of Mn superoxide dismutase (MnSOD) in Lactococcus lactis and Staphylococcus aureus. However, the relationship between acid stress and oxidative stress is not well understood. In the present study, we showed that mutations in the gene coding for MnSOD (sodA) increased the toxicity of lactic acid at pH 3.5 in Streptococcus thermophilus. The inclusion of the iron chelators 2,2'-dipyridyl (DIP), diethienetriamine-pentaacetic acid (DTPA), and O-phenanthroline (O-Phe) provided partial protection against 330 mM lactic acid at pH 3.5. The results suggested that acid stress triggers an iron-mediated oxidative stress that can be ameliorated by MnSOD and iron chelators. These findings were further validated in Escherichia coli strains lacking both MnSOD and iron SOD (FeSOD) but expressing a heterologous MnSOD from S. thermophilus. We also found that, in E. coli, FeSOD did not provide the same protection afforded by MnSOD and that hydroperoxidases are equally important in protecting the cells against acid stress. These findings may explain the ability of some microorganisms to survive better in acidified environments, as in acid foods, during fermentation and accumulation of lactic acid or during passage through the low pH of the stomach. PMID:20305033

  10. Aldehyde-containing urea-absorbing polysaccharides

    NASA Technical Reports Server (NTRS)

    Mueller, W. A.; Hsu, G. C.; Marsh, H. E., Jr. (Inventor)

    1977-01-01

    A novel aldehyde containing polymer (ACP) is prepared by reaction of a polysaccharide with periodate to introduce aldehyde groups onto the C2 - C3 carbon atoms. By introduction of ether and ester groups onto the pendant primary hydroxyl solubility characteristics are modified. The ACP is utilized to absorb nitrogen bases such as urea in vitro or in vivo.

  11. EMISSIONS OF ODOROUS ALDEHYDES FROM ALKYD PAINT

    EPA Science Inventory

    Aldehyde emissions are widely held responsible for the acrid after-odor of drying alkyd-based paint films. The aldehyde emissions from three different alkyd paints were measured in small environmental chambers. It was found that, for each alkyd paint applied, more than 2 mg of ...

  12. Kinetic mechanism of an aldehyde reductase of Saccharomyces cerevisiae that relieves toxicity of furfural and 5-hydroxymethylfurfural

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An effective means of relieving the toxicity of furan aldehydes, furfural (FFA) and 5-hydroxymethylfurfural (HMF), on fermenting organisms is essential for achieving efficient fermentation of lignocellulosic biomass to ethanol and other products. Ari1p, an aldehyde reductase from Saccharomyces cerev...

  13. Antimony(v) cations for the selective catalytic transformation of aldehydes into symmetric ethers, α,β-unsaturated aldehydes, and 1,3,5-trioxanes.

    PubMed

    Arias Ugarte, Renzo; Devarajan, Deepa; Mushinski, Ryan M; Hudnall, Todd W

    2016-07-01

    1-Diphenylphosphinonaphthyl-8-triphenylstibonium triflate ([][OTf]) was prepared in excellent yield by treating 1-lithio-8-diphenylphosphinonaphthalene with dibromotriphenylstiborane followed by halide abstraction with AgOTf. This antimony(v) cation was found to be stable toward oxygen and water, and exhibited exceptional Lewis acidity. The Lewis acidity of [][OTf] was exploited in the catalytic reductive coupling of a variety of aldehydes into symmetric ethers of type in good to excellent yields under mild conditions using Et3SiH as the reductant. Additionally, [][OTf] was found to selectively catalyze the Aldol condensation reaction to afford α-β unsaturated aldehydes () when aldehydes with 2 α-hydrogen atoms were used. Finally, [][OTf] catalyzed the cyclotrimerization of aliphatic and aromatic aldehydes to afford the industrially-useful 1,3,5 trioxanes () in good yields, and with great selectivity. This phosphine-stibonium motif represents one of the first catalytic systems of its kind that is able to catalyze these reactions with aldehydes in a controlled, efficient manner. The mechanism of these processes has been explored both experimentally and theoretically. In all cases the Lewis acidic nature of the antimony(v) cation was found to promote these reactions. PMID:27326797

  14. Electrophilicity and nucleophilicity of commonly used aldehydes.

    PubMed

    Pratihar, Sanjay

    2014-08-14

    The present approach for determining the electrophilicity (E) and nucleophilicity (N) of aldehydes includes a kinetic study of KMNO4 oxidation and NaBH4 reduction of aldehydes. A transition state analysis of the KMNO4 promoted aldehyde oxidation reaction has been performed, which shows a very good correlation with experimental results. The validity of the experimental method has been tested using the experimental activation parameters of the two reactions. The utility of the present approach is further demonstrated by the theoretical versus experimental relationship, which provides easy access to E and N values for various aldehydes and offers an at-a-glance assessment of the chemical reactivity of aldehydes in various reactions. PMID:24979574

  15. Estimating the contribution of organic acids to northern hemispheric continental organic aerosol

    NASA Astrophysics Data System (ADS)

    Yatavelli, Reddy L. N.; Mohr, Claudia; Stark, Harald; Day, Douglas A.; Thompson, Samantha L.; Lopez-Hilfiker, Felipe D.; Campuzano-Jost, Pedro; Palm, Brett B.; Vogel, Alexander L.; Hoffmann, Thorsten; Heikkinen, Liine; ńijälä, Mikko; Ng, Nga L.; Kimmel, Joel R.; Canagaratna, Manjula R.; Ehn, Mikael; Junninen, Heikki; Cubison, Michael J.; Petäjä, Tuukka; Kulmala, Markku; Jayne, John T.; Worsnop, Douglas R.; Jimenez, Jose L.

    2015-07-01

    Using chemical ionization mass spectrometry to detect particle-phase acids and aerosol mass spectrometry (AMS) measurements from Colorado, USA, and two studies in Hyytiälä, Finland, we quantify the fraction of organic aerosol (OA) mass that is composed of molecules with acid functional groups (facid). Molecules containing one or more carboxylic acid functionality contributed approximately 29% (45-51%) of the OA mass in Colorado (Finland). Organic acid mass concentration correlates well with AMS m/z 44 (primarily CO2+), a commonly used marker for highly oxidized aerosol. Using the average empirical relationship between AMS m/z 44 and organic acids in these three studies, together with m/z 44 data from 29 continental northern hemispheric (NH) AMS data sets, we estimate that molecules containing carboxylic acid functionality constitute on average 28% (range 10-50%) of NH continental OA mass with typically higher values at rural/remote sites and during summer and lower values at urban sites and during winter.

  16. Mouse aldehyde-oxidase-4 controls diurnal rhythms, fat deposition and locomotor activity

    PubMed Central

    Terao, Mineko; Barzago, Maria Monica; Kurosaki, Mami; Fratelli, Maddalena; Bolis, Marco; Borsotti, Andrea; Bigini, Paolo; Micotti, Edoardo; Carli, Mirjana; Invernizzi, Roberto William; Bagnati, Renzo; Passoni, Alice; Pastorelli, Roberta; Brunelli, Laura; Toschi, Ivan; Cesari, Valentina; Sanoh, Seigo; Garattini, Enrico

    2016-01-01

    Aldehyde-oxidase-4 (AOX4) is one of the mouse aldehyde oxidase isoenzymes and its physiological function is unknown. The major source of AOX4 is the Harderian-gland, where the enzyme is characterized by daily rhythmic fluctuations. Deletion of the Aox4 gene causes perturbations in the expression of the circadian-rhythms gene pathway, as indicated by transcriptomic analysis. AOX4 inactivation alters the diurnal oscillations in the expression of master clock-genes. Similar effects are observed in other organs devoid of AOX4, such as white adipose tissue, liver and hypothalamus indicating a systemic action. While perturbations of clock-genes is sex-independent in the Harderian-gland and hypothalamus, sex influences this trait in liver and white-adipose-tissue which are characterized by the presence of AOX isoforms other than AOX4. In knock-out animals, perturbations in clock-gene expression are accompanied by reduced locomotor activity, resistance to diet induced obesity and to hepatic steatosis. All these effects are observed in female and male animals. Resistance to obesity is due to diminished fat accumulation resulting from increased energy dissipation, as white-adipocytes undergo trans-differentiation towards brown-adipocytes. Metabolomics and enzymatic data indicate that 5-hydroxyindolacetic acid and tryptophan are novel endogenous AOX4 substrates, potentially involved in AOX4 systemic actions. PMID:27456060

  17. The short-chain alcohol dehydrogenase ABA2 catalyzes the conversion of xanthoxin to abscisic aldehyde.

    PubMed

    González-Guzmán, Miguel; Apostolova, Nadezda; Bellés, José M; Barrero, José M; Piqueras, Pedro; Ponce, María R; Micol, José L; Serrano, Ramón; Rodríguez, Pedro L

    2002-08-01

    Mutants able to germinate and perform early growth in medium containing a high NaCl concentration were identified during the course of two independent screenings and named salt resistant (sre) and salobreño (sañ). The sre and sañ mutants also were able to germinate in high-osmoticum medium, indicating that they are osmotolerant in a germination assay. Complementation analyses revealed that sre1-1, sre1-2, sañ3-1, and sañ3-2 were alleles of the abscisic acid (ABA) biosynthesis ABA2 gene. A map-based cloning strategy allowed the identification of the ABA2 gene and molecular characterization of four new aba2 alleles. The ABA2 gene product belongs to the family of short-chain dehydrogenases/reductases, which are known to be NAD- or NADP-dependent oxidoreductases. Recombinant ABA2 protein produced in Escherichia coli exhibits a K(m) value for xanthoxin of 19 micro M and catalyzes in a NAD-dependent manner the conversion of xanthoxin to abscisic aldehyde, as determined by HPLC-mass spectrometry. The ABA2 mRNA is expressed constitutively in all plant organs examined and is not upregulated in response to osmotic stress. The results of this work are discussed in the context of previous genetic and biochemical evidence regarding ABA biosynthesis, confirming the xanthoxin-->abscisic aldehyde-->ABA transition as the last steps of the major ABA biosynthetic pathway. PMID:12172025

  18. Mouse aldehyde-oxidase-4 controls diurnal rhythms, fat deposition and locomotor activity.

    PubMed

    Terao, Mineko; Barzago, Maria Monica; Kurosaki, Mami; Fratelli, Maddalena; Bolis, Marco; Borsotti, Andrea; Bigini, Paolo; Micotti, Edoardo; Carli, Mirjana; Invernizzi, Roberto William; Bagnati, Renzo; Passoni, Alice; Pastorelli, Roberta; Brunelli, Laura; Toschi, Ivan; Cesari, Valentina; Sanoh, Seigo; Garattini, Enrico

    2016-01-01

    Aldehyde-oxidase-4 (AOX4) is one of the mouse aldehyde oxidase isoenzymes and its physiological function is unknown. The major source of AOX4 is the Harderian-gland, where the enzyme is characterized by daily rhythmic fluctuations. Deletion of the Aox4 gene causes perturbations in the expression of the circadian-rhythms gene pathway, as indicated by transcriptomic analysis. AOX4 inactivation alters the diurnal oscillations in the expression of master clock-genes. Similar effects are observed in other organs devoid of AOX4, such as white adipose tissue, liver and hypothalamus indicating a systemic action. While perturbations of clock-genes is sex-independent in the Harderian-gland and hypothalamus, sex influences this trait in liver and white-adipose-tissue which are characterized by the presence of AOX isoforms other than AOX4. In knock-out animals, perturbations in clock-gene expression are accompanied by reduced locomotor activity, resistance to diet induced obesity and to hepatic steatosis. All these effects are observed in female and male animals. Resistance to obesity is due to diminished fat accumulation resulting from increased energy dissipation, as white-adipocytes undergo trans-differentiation towards brown-adipocytes. Metabolomics and enzymatic data indicate that 5-hydroxyindolacetic acid and tryptophan are novel endogenous AOX4 substrates, potentially involved in AOX4 systemic actions. PMID:27456060

  19. Biochar: a green sorbent to sequester acidic organic contaminants

    NASA Astrophysics Data System (ADS)

    Sigmund, Gabriel; Kah, Melanie; Sun, Huichao; Hofmann, Thilo

    2015-04-01

    Biochar is a carbon rich product of biomass pyrolysis that exhibits a high sorption potential towards a wide variety of inorganic and organic contaminants. Because it is a valuable soil additive and a potential carbon sink that can be produced from renewable resources, biochar has gained growing attention for the development of more sustainable remediation strategies. A lot of research efforts have been dedicated to the sorption of hydrophobic contaminants and metals to biochar. Conversely, the understanding of the sorption of acidic organic contaminants remains limited, and questions remain on the influence of biochar characteristics (e.g. ash content) on the sorption behaviour of acidic organic contaminants. To address this knowledge gap, sorption batch experiments were conducted with a series of structurally similar acidic organic contaminants covering a range of dissociation constant (2,4-D, MCPA, 2,4-DB and triclosan). The sorbents selected for experimentation included a series of 10 biochars covering a range of characteristics, multiwalled carbon nanotubes as model for pure carbonaceous phases, and an activated carbon as benchmark. Overall, sorption coefficient [L/kg] covered six orders of magnitude and generally followed the order 2,4-D < MCPA < 2,4-DB < triclosan. Combining comprehensive characterization of the sorbents with the sorption dataset allowed the discussion of sorption mechanisms and driving factors of sorption. Statistical analysis suggests that (i) partitioning was the main driver for sorption to sorbents with small specific surface area (< 25 m²/g), whereas (ii) specific mechanisms dominated sorption to sorbents with larger specific surface area. Results showed that factors usually not considered for the sorption of neutral contaminants play an important role for the sorption of organic acids. The pH dependent lipophilicity ratio (i.e. D instead of Kow), ash content and ionic strength are key factors influencing the sorption of acidic organic

  20. Human brain aldehyde reductases: relationship to succinic semialdehyde reductase and aldose reductase.

    PubMed

    Hoffman, P L; Wermuth, B; von Wartburg, J P

    1980-08-01

    Human brain contains multiple forms of aldehyde-reducing enzymes. One major form (AR3), as previously shown, has properties that indicate its identity with NADPH-dependent aldehyde reductase isolated from brain and other organs of various species; i.e., low molecular weight, use of NADPH as the preferred cofactor, and sensitivity to inhibition by barbiturates. A second form of aldehyde reductase ("SSA reductase") specifically reduces succinic semialdehyde (SSA) to produce gamma-hydroxybutyrate. This enzyme form has a higher molecular weight than AR3, and uses NADH as well as NADPH as cofactor. SSA reductase was not inhibited by pyrazole, oxalate, or barbiturates, and the only effective inhibitor found was the flavonoid quercetine. Although AR3 can also reduce SSA, the relative specificity of SSA reductase may enhance its in vivo role. A third form of human brain aldehyde reductase, AR2, appears to be comparable to aldose reductases characterized in several species, on the basis of its activity pattern with various sugar aldehydes and its response to characteristic inhibitors and activators, as well as kinetic parameters. This enzyme is also the most active in reducing the aldehyde derivatives of biogenic amines. These studies suggest that the various forms of human brain aldehyde reductases may have specific physiological functions. PMID:6778961

  1. Chemical modification of aldehyde dehydrogenase by a vinyl ketone analogue of an insect pheromone.

    PubMed

    Blatter, E E; Tasayco, M L; Prestwich, G; Pietruszko, R

    1990-12-01

    A major component of the sex pheromone from the tobacco budworm moth Heliothis virescens is a C16 straight-chain aldehyde with a single unsaturation at the eleventh position. The sex pheromones are inactivated when metabolized to their corresponding acids by insect aldehyde dehydrogenase. During this investigation it was demonstrated that the C16 aldehyde is a good substrate for human aldehyde dehydrogenase (EC 1.2.1.3) isoenzymes E1 and E2 with Km and Kcat. values at pH 7.0 of 2 microM and 0.4 mumol of NADH/min per mg and of 0.6 microM and 0.24 mumol of NADH/min per mg respectively. A vinyl ketone analogue of the pheromone inhibited insect pheromone metabolism; it also inactivated human aldehyde dehydrogenase. Total inactivation of both isoenzymes was achieved at stoichiometric (equal or less than the subunit number) concentrations of vinyl ketone, incorporating 2.1-2.6 molecules/molecule of enzyme. Substrate protection was observed in the presence of the parent aldehyde and 5'-AMP. Peptide maps of tryptic digests of the E2 isoenzyme modified with 3H-labelled vinyl ketone showed that incorporation occurred into a single peptide peak. The labelled peptide of E2 isoenzyme was further purified on h.p.l.c. and sequenced. The label was incorporated into cysteine-302 in the primary structure of E2 isoenzyme, thus indicating that cysteine-302 is located in the aldehyde substrate area of the active site of aldehyde dehydrogenase. Affinity labelling of aldehyde dehydrogenase with vinyl ketones may prove to be of general utility in biochemical studies of these enzymes. PMID:2268265

  2. Capillary electrophoresis analysis of organic amines and amino acids in saline and acidic samples using the Mars organic analyzer.

    PubMed

    Stockton, Amanda M; Chiesl, Thomas N; Lowenstein, Tim K; Amashukeli, Xenia; Grunthaner, Frank; Mathies, Richard A

    2009-11-01

    The Mars Organic Analyzer (MOA) has enabled the sensitive detection of amino acid and amine biomarkers in laboratory standards and in a variety of field sample tests. However, the MOA is challenged when samples are extremely acidic and saline or contain polyvalent cations. Here, we have optimized the MOA analysis, sample labeling, and sample dilution buffers to handle such challenging samples more robustly. Higher ionic strength buffer systems with pK(a) values near pH 9 were developed to provide better buffering capacity and salt tolerance. The addition of ethylaminediaminetetraacetic acid (EDTA) ameliorates the negative effects of multivalent cations. The optimized protocol utilizes a 75 mM borate buffer (pH 9.5) for Pacific Blue labeling of amines and amino acids. After labeling, 50 mM (final concentration) EDTA is added to samples containing divalent cations to ameliorate their effects. This optimized protocol was used to successfully analyze amino acids in a saturated brine sample from Saline Valley, California, and a subcritical water extract of a highly acidic sample from the Río Tinto, Spain. This work expands the analytical capabilities of the MOA and increases its sensitivity and robustness for samples from extraterrestrial environments that may exhibit pH and salt extremes as well as metal ions. PMID:19968460

  3. DISTRIBUTION OF HYDROPHOBIC IONOGENIC ORGANIC COMPOUNDS BETWEEN OCTANOL AND WATER: ORGANIC ACIDS

    EPA Science Inventory

    The octanol-water distributions of 10 environmentally significant organic acid compounds were determined as a function of aqueous-phase salt concentration (0.05-0.2 M LiCl, NaCl, KCl, CaCl2, or MgCl2) and pH. he compounds were pentachlorophenol 2,3,4,5-tetrachlorophenol, (2,4,5-t...

  4. Toward aldehyde and alkane production by removing aldehyde reductase activity in Escherichia coli

    PubMed Central

    Rodriguez, Gabriel M.; Atsumi, Shota

    2015-01-01

    Advances in synthetic biology and metabolic engineering have enabled the construction of novel biological routes to valuable chemicals using suitable microbial hosts. Aldehydes serve as chemical feedstocks in the synthesis of rubbers, plastics, and other larger molecules. Microbial production of alkanes is dependent on the formation of a fatty aldehyde intermediate which is converted to an alkane by an aldehyde deformylating oxygenase (ADO). However, microbial hosts such as Escherichia coli are plagued by many highly active endogenous aldehyde reductases (ALRs) that convert aldehydes to alcohols, which greatly complicates strain engineering for aldehyde and alkane production. It has been shown that the endogenous ALR activity outcompetes the ADO enzyme for fatty aldehyde substrate. The large degree of ALR redundancy coupled with an incomplete database of ALRs represents a significant obstacle in engineering E. coli for either aldehyde or alkane production. In this study, we identified 44 ALR candidates encoded in the E. coli genome using bioinformatics tools, and undertook a comprehensive screening by measuring the ability of these enzymes to produce isobutanol. From the pool of 44 candidates, we found five new ALRs using this screening method (YahK, DkgA, GldA, YbbO, and YghA). Combined deletions of all 13 known ALRs resulted in a 90–99% reduction in endogenous ALR activity for a wide range of aldehyde substrates (C2–C12). Elucidation of the ALRs found in E. coli could guide one in reducing competing alcohol formation during alkane or aldehyde production. PMID:25108218

  5. Molecular cloning of a plant betaine-aldehyde dehydrogenase, an enzyme implicated in adaptation to salinity and drought.

    PubMed

    Weretilnyk, E A; Hanson, A D

    1990-04-01

    Many plants, as well as other organisms, accumulate betaine (N,N,N-trimethylglycine) as a nontoxic or protective osmolyte under saline or dry conditions. In plants, the last step in betaine synthesis is catalyzed by betaine-aldehyde dehydrogenase (BADH, EC 1.2.1.8), a nuclear-encoded chloroplastic enzyme. A cDNA clone for BADH (1812 base pairs) was selected from a lambda gt10 cDNA library derived from leaves of salt-stressed spinach (Spinacia oleracea L.). The library was screened with oligonucleotide probes corresponding to amino acid sequences of two peptides prepared from purified BADH. The authenticity of the clone was confirmed by nucleotide sequence analysis; this analysis demonstrated the presence of a 1491-base-pair open reading frame that contained sequences encoding 12 peptide fragments of BADH. The clone hybridized to a 1.9-kilobase mRNA from spinach leaves; this mRNA was more abundant in salt-stressed plants, consistent with the known salt induction of BADH activity. The amino acid sequence deduced from the BADH cDNA sequence showed substantial similarities to those for nonspecific aldehyde dehydrogenases (EC 1.2.1.3 and EC 1.2.1.5) from several sources, including absolute conservation of a decapeptide in the probable active site. Comparison of deduced and determined amino acid sequences indicated that the transit peptide may comprise only 7 or 8 residues, which is atypically short for precursors to stromal proteins. PMID:2320587

  6. Part I. Synthesis and characterization of donor-pi-acceptor compounds with pentadienyl-bridged indoline and tetrahydroquinoline donors and aldehyde and thiobarbituric acid acceptors Part II. Longitudinal study comparing online versus face-to-face course delivery in introductory chemistry

    NASA Astrophysics Data System (ADS)

    Greco, Patrick F.

    Part I. The design and development of organic second-order nonlinear optical (NLO) materials have attracted much interest due to their applications in optoelectronic devices and modern communications technology. Donor-pi-acceptor compounds, D-(CH=CH)n-A, often exhibit hyperpolarizability that results in laser frequency doubling (second harmonic generation) and spectroscopic solvatochromism. To study the effect of donor amine geometry upon properties associated with second-order NLO behavior in simple donor-pi-acceptor compounds, equilibrium geometries and hyperpolarizabilities (beta) for donor-acceptor polyenes with amine donors were calculated at several levels of computational theory. Two new molecules with donors that only differ by one methylene group were chosen for comparison. Thus, 5-(N-methylindolin-5-yl)-2, 4-pentadienal (1a) and 5-(N-methyl-2, 3, 4-trihydroquinolin-6-yl)-2, 4-pentadienal (2a) were synthesized in two steps from starting materials described in the literature. These aldehydes were converted into stronger acceptors in one step to give diethylthiobarbituric acid derivatives 1c and 2c, as well as tricyanofuran derivatives 1d and 2d. Positive UV solvatochromism was observed in all three derivatives. NMR solvatochromism was most pronounced in 1c, and 2c vs. 1a and 2a as measured by changes in chemical shifts. Additionally, coupling constants showed more conjugation in 1c and 2c, where 1a and 2a showed less conjugation. Finally, differential scanning calorimetry and thermal gravimetric analysis were used to compare decomposition and melting temperatures of these compounds to determine their stability. Aldehydes, 1a and 2a had distinct melting points, while the 1c, 2c, 1d, and 2d derivatives decomposed at temperatures above 150 °C. Part II. This longitudinal study focused on an introductory chemistry course taught using two different modes of delivery: online and face-to-face (FtF). The sections of the course using the different delivery modes

  7. Proton-binding study of standard and reference fulvic acids, humic acids, and natural organic matter

    NASA Astrophysics Data System (ADS)

    Ritchie, Jason D.; Perdue, E. Michael

    2003-01-01

    The acid-base properties of 14 standard and reference materials from the International Humic Substances Society (IHSS) were investigated by potentiometric titration. Titrations were conducted in 0.1 M NaCl under a nitrogen atmosphere, averaging 30 min from start to finish. Concentrations of carboxyl groups and phenolic groups were estimated directly from titration curves. Titration data were also fit to a modified Henderson-Hasselbalch model for two classes of proton-binding sites to obtain "best fit" parameters that describe proton-binding curves for the samples. The model was chosen for its simplicity, its ease of implementation in computer spreadsheets, and its excellent ability to describe the shapes of the titration curves. The carboxyl contents of the IHSS samples are in the general order: terrestrial fulvic acids > aquatic fulvic acids > Suwannee River natural organic matter (NOM) > aquatic humic acids > terrestrial humic acids. Overall, fulvic acids and humic acids have similar phenolic contents; however, all of the aquatically derived samples have higher phenolic contents than the terrestrially derived samples. The acid-base properties of reference Suwannee River NOM are surprisingly similar to those of standard Suwannee River humic acid. Results from titrations in this study were compared with other published results from both direct and indirect titrations. Typically, carboxyl contents for the IHSS samples were in agreement with the results from both methods of titration. Phenolic contents for the IHSS samples were comparable to those determined by direct titrations, but were significantly less than estimates of phenolic content that were based on indirect titrations with Ba(OH) 2 and Ca(OAc) 2. The average phenolic-to-carboxylic ratio of the IHSS samples is approximately 1:4. Models that assume a 1:2 ratio of phenolic-to-carboxylic groups may overestimate the relative contribution of phenolic groups to the acid-base chemistry of humic substances.

  8. Nickel deficiency disrupts metabolism of ureides, amino acids, and organic acids of young pecan foliage.

    PubMed

    Bai, Cheng; Reilly, Charles C; Wood, Bruce W

    2006-02-01

    The existence of nickel (Ni) deficiency is becoming increasingly apparent in crops, especially for ureide-transporting woody perennials, but its physiological role is poorly understood. We evaluated the concentrations of ureides, amino acids, and organic acids in photosynthetic foliar tissue from Ni-sufficient (Ni-S) versus Ni-deficient (Ni-D) pecan (Carya illinoinensis [Wangenh.] K. Koch). Foliage of Ni-D pecan seedlings exhibited metabolic disruption of nitrogen metabolism via ureide catabolism, amino acid metabolism, and ornithine cycle intermediates. Disruption of ureide catabolism in Ni-D foliage resulted in accumulation of xanthine, allantoic acid, ureidoglycolate, and citrulline, but total ureides, urea concentration, and urease activity were reduced. Disruption of amino acid metabolism in Ni-D foliage resulted in accumulation of glycine, valine, isoleucine, tyrosine, tryptophan, arginine, and total free amino acids, and lower concentrations of histidine and glutamic acid. Ni deficiency also disrupted the citric acid cycle, the second stage of respiration, where Ni-D foliage contained very low levels of citrate compared to Ni-S foliage. Disruption of carbon metabolism was also via accumulation of lactic and oxalic acids. The results indicate that mouse-ear, a key morphological symptom, is likely linked to the toxic accumulation of oxalic and lactic acids in the rapidly growing tips and margins of leaflets. Our results support the role of Ni as an essential plant nutrient element. The magnitude of metabolic disruption exhibited in Ni-D pecan is evidence of the existence of unidentified physiological roles for Ni in pecan. PMID:16415214

  9. Comparison of capillary pressure relationships of organic liquid water systems containing an organic acid or base

    NASA Astrophysics Data System (ADS)

    Lord, D. L.; Demond, A. H.; Hayes, K. F.

    2005-04-01

    The presence of surface-active solutes such as organic acids and bases may have a profound influence on the transport of organic liquid contaminants through their impact on the constitutive relationship of capillary pressure vs. saturation. This relationship is a function of the interfacial tension and wettability of the system, which, in turn, depend on the pH and the concentration of organic acids and bases that are present. This study examines the impact of pH and the concentration on the interfacial tension, contact angle, and capillary pressure of systems consisting of tetrachloroethylene, water, and quartz containing either octanoic acid or dodecylamine. In general, the ionic form of the solute tended to remain in the aqueous phase and reduced the capillary pressure through its impact on the interfacial tension and contact angle; on the other hand, the neutral form of the solute partitioned into the organic liquid phase and had a lesser impact on the capillary pressure for the same total mass of solute. A comparison of these data with data generated in previous research in similar systems where o-xylene was the organic liquid showed that the trends are analogous. Thus, the behavior of these two solvent systems seems to be driven primarily by the aqueous phase speciation of the solute, and the differences between the capillary pressure relationships for the two systems could be attributed to the pure system interfacial tension.

  10. A Green Multicomponent Reaction for the Organic Chemistry Laboratory: The Aqueous Passerini Reaction

    ERIC Educational Resources Information Center

    Hooper, Matthew M.; DeBoef, Brenton

    2009-01-01

    Water is the ideal green solvent for organic reactions. However, most organic molecules are insoluble in it. Herein, we report a laboratory module that takes advantage of this property. The Passerini reaction, a three-component coupling involving an isocyanide, aldehyde, and carboxylic acid, typically requires [similar to] 24 h reaction times in…

  11. Crystal and molecular structure of eight organic acid-base adducts from 2-methylquinoline and different acids

    NASA Astrophysics Data System (ADS)

    Zhang, Jing; Jin, Shouwen; Tao, Lin; Liu, Bin; Wang, Daqi

    2014-08-01

    Eight supramolecular complexes with 2-methylquinoline and acidic components as 4-aminobenzoic acid, 2-aminobenzoic acid, salicylic acid, 5-chlorosalicylic acid, 3,5-dinitrosalicylic acid, malic acid, sebacic acid, and 1,5-naphthalenedisulfonic acid were synthesized and characterized by X-ray crystallography, IR, mp, and elemental analysis. All of the complexes are organic salts except compound 2. All supramolecular architectures of 1-8 involve extensive classical hydrogen bonds as well as other noncovalent interactions. The results presented herein indicate that the strength and directionality of the classical hydrogen bonds (ionic or neutral) between acidic components and 2-methylquinoline are sufficient to bring about the formation of binary organic acid-base adducts. The role of weak and strong noncovalent interactions in the crystal packing is ascertained. These weak interactions combined, the complexes 1-8 displayed 2D-3D framework structure.

  12. Predictions of diagenetic reactions in the presence of organic acids

    NASA Astrophysics Data System (ADS)

    Harrison, Wendy J.; Thyne, Geoffrey D.

    1992-02-01

    Stability constants have been estimated for cation complexes with anions of monofunctional and difunctional acids (combinations of Ca, Mg, Fe, Al, Sr, Mn, U, Th, Pb, Cu, Zn with formate, acetate, propionate, oxalate, malonate, succinate, and salicylate) between 0 and 200°C. Difunctional acid anions form much more stable complexes than monofunctional acid anions with aluminum; the importance of the aluminum-acetate complex is relatively minor in comparison to aluminum oxalate and malonate complexes. Divalent metal cations such as Mg, Ca, and Fe form more stable complexes with acetate than with difunctional acid anions. Aluminum-oxalate can dominate the species distribution of aluminum under acidic pH conditions, whereas the divalent cation-acetate and oxalate complexes rarely account for more than 60% of the total dissolved cation, and then only in more alkaline waters. Mineral thermodynamic affinities were calculated using the reaction path model EQ3/6 for waters having variable organic acid anion (OAA) contents under conditions representative of those found during normal burial diagenesis. The following scenarios are possible: 1) K-feldspar and albite are stable, anorthite dissolves 2) All feldpars are stable 3) Carbonates can be very unstable to slightly unstable, but never increase in stability. Organic acid anions are ineffective at neutral to alkaline pH in modifying stabilities of aluminosilicate minerals whereas the anions are variably effective under a wide range of pH in modifying carbonate mineral stabilities. Reaction path calculations demonstrate that the sequence of mineral reactions occurring in an arkosic sandstone-fluid system is only slightly modified by the presence of OAA. A spectrum of possible sandstone alteration mineralogies can be obtained depending on the selected boundary conditions: EQ3/6 predictions include quartz overgrowth, calcite replacement of plagioclase, albitization of plagioclase, and the formation of porosity-occluding calcite

  13. Nanogels based on alginic aldehyde and gelatin by inverse miniemulsion technique: synthesis and characterization.

    PubMed

    Sarika, P R; Anil Kumar, P R; Raj, Deepa K; James, Nirmala Rachel

    2015-03-30

    Nanogels were developed from alginic aldehyde and gelatin by an inverse miniemulsion technique. Stable inverse miniemulsions were prepared by sonication of noncontinuous aqueous phase (mixture of alginic aldehyde and gelatin) in a continuous organic phase (Span 20 dissolved in cyclohexane). Cross-linking occurred between alginic aldehyde (AA) and gelatin (gel) in the presence of borax by Schiff's base reaction during the formation of inverse miniemulsion. The effects of surfactant (Span 20) concentration, volume of the aqueous phase and AA/gel weight ratio on the size of the alginic aldehyde-gelatin (AA-gel) nanoparticles were studied. Nanogels were characterized by DLS, FT-IR spectroscopy, TGA, SEM and TEM. DLS, TEM and SEM studies demonstrated nanosize and spherical morphology of the nanogels. Hemocompatibility and in vitro cytocompatibility analyses of the nanogels proved their nontoxicity. The results indicated the potential of the present nanogel system as a candidate for drug- and gene-delivery applications. PMID:25563951

  14. Substrate specificity and catalytic efficiency of aldo-keto reductases with phospholipid aldehydes

    PubMed Central

    Spite, Matthew; Baba, Shahid P.; Ahmed, Yonis; Barski, Oleg A.; Nijhawan, Kanchan; Petrash, J. Mark; Bhatnagar, Aruni; Srivastava, Sanjay

    2007-01-01

    Phospholipid oxidation generates several bioactive aldehydes that remain esterified to the glycerol backbone (‘core’ aldehydes). These aldehydes induce endothelial cells to produce monocyte chemotactic factors and enhance monocyte–endothelium adhesion. They also serve as ligands of scavenger receptors for the uptake of oxidized lipoproteins or apoptotic cells. The biochemical pathways involved in phospholipid aldehyde metabolism, however, remain largely unknown. In the present study, we have examined the efficacy of the three mammalian AKR (aldo-keto reductase) families in catalysing the reduction of phospholipid aldehydes. The model phospholipid aldehyde POVPC [1-palmitoyl-2-(5-oxovaleroyl)-sn-glycero-3-phosphocholine] was efficiently reduced by members of the AKR1, but not by the AKR6 or the ARK7 family. In the AKR1 family, POVPC reductase activity was limited to AKR1A and B. No significant activity was observed with AKR1C enzymes. Among the active proteins, human AR (aldose reductase) (AKR1B1) showed the highest catalytic activity. The catalytic efficiency of human small intestinal AR (AKR1B10) was comparable with the murine AKR1B proteins 1B3 and 1B8. Among the murine proteins AKR1A4 and AKR1B7 showed appreciably lower catalytic activity as compared with 1B3 and 1B8. The human AKRs, 1B1 and 1B10, and the murine proteins, 1B3 and 1B8, also reduced C-7 and C-9 sn-2 aldehydes as well as POVPE [1-palmitoyl-2-(5-oxovaleroyl)-sn-glycero-3-phosphoethanolamine]. AKR1A4, B1, B7 and B8 catalysed the reduction of aldehydes generated in oxidized C16:0-20:4 phosphatidylcholine with acyl, plasmenyl or alkyl linkage at the sn-1 position or C16:0-20:4 phosphatidylglycerol or phosphatidic acid. AKR1B1 displayed the highest activity with phosphatidic acids; AKR1A4 was more efficient with long-chain aldehydes such as 5-hydroxy-8-oxo-6-octenoyl derivatives, whereas AKR1B8 preferred phosphatidylglycerol. These results suggest that proteins of the AKR1A and B families are

  15. Chromatographic analysis of amino and organic acids in physiological fluids to detect inborn errors of metabolism.

    PubMed

    Woontner, Michael; Goodman, Stephen I

    2006-11-01

    This unit describes methods for the preparation of samples for analysis of physiological amino acids and organic acids. Amino acids are analyzed by ion-exchange chromatography using an automated system. Organic acids are analyzed by gas-chromatography/mass spectrometry (GC-MS). Analysis of amino and organic acids is necessary to detect and monitor the treatment of many inborn errors of metabolism. PMID:18428392

  16. Aldehyde dehydrogenases in cellular responses to oxidative/electrophilic stress.

    PubMed

    Singh, Surendra; Brocker, Chad; Koppaka, Vindhya; Chen, Ying; Jackson, Brian C; Matsumoto, Akiko; Thompson, David C; Vasiliou, Vasilis

    2013-03-01

    Reactive oxygen species (ROS) are continuously generated within living systems and the inability to manage ROS load leads to elevated oxidative stress and cell damage. Oxidative stress is coupled to the oxidative degradation of lipid membranes, also known as lipid peroxidation. This process generates over 200 types of aldehydes, many of which are highly reactive and toxic. Aldehyde dehydrogenases (ALDHs) metabolize endogenous and exogenous aldehydes and thereby mitigate oxidative/electrophilic stress in prokaryotic and eukaryotic organisms. ALDHs are found throughout the evolutionary gamut, from single-celled organisms to complex multicellular species. Not surprisingly, many ALDHs in evolutionarily distant, and seemingly unrelated, species perform similar functions, including protection against a variety of environmental stressors such as dehydration and ultraviolet radiation. The ability to act as an "aldehyde scavenger" during lipid peroxidation is another ostensibly universal ALDH function found across species. Upregulation of ALDHs is a stress response in bacteria (environmental and chemical stress), plants (dehydration, salinity, and oxidative stress), yeast (ethanol exposure and oxidative stress), Caenorhabditis elegans (lipid peroxidation), and mammals (oxidative stress and lipid peroxidation). Recent studies have also identified ALDH activity as an important feature of cancer stem cells. In these cells, ALDH expression helps abrogate oxidative stress and imparts resistance against chemotherapeutic agents such as oxazaphosphorine, taxane, and platinum drugs. The ALDH superfamily represents a fundamentally important class of enzymes that contributes significantly to the management of electrophilic/oxidative stress within living systems. Mutations in various ALDHs are associated with a variety of pathological conditions in humans, highlighting the fundamental importance of these enzymes in physiological and pathological processes. PMID:23195683

  17. Field enhancement sample stacking for analysis of organic acids in traditional Chinese medicine by capillary electrophoresis.

    PubMed

    Zhu, Qianqian; Xu, Xueqin; Huang, Yuanyuan; Xu, Liangjun; Chen, Guonan

    2012-07-13

    A technique known as field enhancement sample stacking (FESS) and capillary electrophoresis (CE) separation has been developed to analyze and detect organic acids in the three traditional Chinese medicines (such as Portulaca oleracea L., Crataegus pinnatifida and Aloe vera L.). In FESS, a reverse electrode polarity-stacking mode (REPSM) was applied as on-line preconcentration strategy. Under the optimized condition, the baseline separation of eight organic acids (linolenic acid, lauric acid, p-coumaric acid, ascorbic acid, benzoic acid, caffeic acid, succinic acid and fumaric acid) could be achieved within 20 min. Validation parameters of this method (such as detection limits, linearity and precision) were also evaluated. The detection limits ranged from 0.4 to 60 ng/mL. The results indicated that the proposed method was effective for the separation of mixtures of organic acids. Satisfactory recoveries were also obtained in the analysis of these organic acids in the above traditional Chinese medicine samples. PMID:22381886

  18. Organic Acids as Hetrotrophic Energy Sources in Hydrothermal Systems

    NASA Astrophysics Data System (ADS)

    Windman, T. O.; Zolotova, N.; Shock, E.

    2004-12-01

    Many thermophilic microbes are heterotrophs, but little is known about the organic compounds present in hydrothermal ecosystems. More is known about what these organisms will metabolize in lab experiments than what they do metabolize in nature. In an effort to bridge this gap, we have begun to incorporate organic analyses into ongoing research on Yellowstone hydrothermal ecosystems. After filtering at least a liter of hot spring water to minimize contamination, samples were collected into sixty-milliliter serum vials containing ultra-pure phosphoric acid, sodium hydroxide, or benzalkonium chloride. Approximately 80 sites were sampled spanning temperatures from 60 to 90°C and pH values from 2 to 9. Analytical data for organic acid anions (including formate, acetate, lactate, and succinate) were obtained by ion chromatography. Preliminary results indicate that concentrations of organic acids anions range from 5 to 300 ppb. These results can be used with other field and lab data (sulfate, sulfide, nitrate, ammonia, bicarbonate, pH, hydrogen) in thermodynamic calculations to evaluate the amounts of energy available in heterotrophic reactions. Preliminary results of such calculations show that sulfate reduction to sulfide coupled to succinate oxidation to bicarbonate yields about 6 kcal per mole of electrons transferred. When formate oxidation to bicarbonate or hydrogen oxidation to water is coupled to sulfate reduction there is less energy available by approximately a factor of two. A comparison with nitrate reduction to ammonia involving succinate and/or formate oxidation reveals several similarities. Using formate to reduce nitrate can yield about as much energy as nitrate reduction with hydrogen (typically 12 to 14 kcal per mole of electrons transferred), but using succinate can yield more than twice as much energy. In fact, reduction of nitrate with succinate can provide more energy than any of the inorganic nitrate reduction reactions involving sulfur, iron

  19. Engineering Porous Organic Cage Crystals with Increased Acid Gas Resistance.

    PubMed

    Zhu, Guanghui; Hoffman, Christopher D; Liu, Yang; Bhattacharyya, Souryadeep; Tumuluri, Uma; Jue, Melinda L; Wu, Zili; Sholl, David S; Nair, Sankar; Jones, Christopher W; Lively, Ryan P

    2016-07-25

    Both known and new CC3-based porous organic cages are prepared and exposed to acidic SO2 in vapor and liquid conditions. Distinct differences in the stability of the CC3 cages exist depending on the chirality of the diamine linkers used. The acid catalyzed CC3 degradation mechanism is probed via in situ IR and a degradation pathway is proposed and supported with computational results. CC3 crystals synthesized with racemic mixtures of diaminocyclohexane exhibited enhanced stability compared to CC3-R and CC3-S. Confocal fluorescent microscope images reveal that the stability difference in CC3 species originates from an abundance of mesoporous grain boundaries in CC3-R and CC3-S, allowing facile access of aqueous SO2 throughout the crystal, promoting decomposition. These grain boundaries are absent from CC3 crystals made with racemic linkers. PMID:27253350

  20. DC diaphragm discharge in water solutions of selected organic acids

    NASA Astrophysics Data System (ADS)

    Vyhnankova, Edita J.; Hammer, Malte U.; Reuter, Stephan; Krcma, Frantisek

    2015-07-01

    Effect of four simple organic acids water solution on a DC diaphragm discharge was studied. Efficiency of the discharge was quantified by the hydrogen peroxide production determined by UV-VIS spectrometry of a H2O2 complex formed with specific titanium reagent. Automatic titration was used to study the pH behaviour after the plasma treatment. Optical emission spectroscopy overview spectra were recorded and detailed spectra of OH band and Hβ line were used to calculate the rotational temperature and comparison of the line profile (reflecting electron concentration) in the acid solutions. Contribution to the topical issue "The 14th International Symposium on High Pressure Low Temperature Plasma Chemistry (HAKONE XIV)", edited by Nicolas Gherardi, Ronny Brandenburg and Lars Stollenwark

  1. Control of Meloidogyne incognita Using Mixtures of Organic Acids

    PubMed Central

    Seo, Yunhee; Kim, Young Ho

    2014-01-01

    This study sought to control the root-knot nematode (RKN) Meloidogyne incognita using benign organo-chemicals. Second-stage juveniles (J2) of RKN were exposed to dilutions (1.0%, 0.5%, 0.2%, and 0.1%) of acetic acid (AA), lactic acid (LA), and their mixtures (MX). The nematode bodies were disrupted severely and moderately by vacuolations in 0.5% of MX and single organic acids, respectively, suggesting toxicity of MX may be higher than AA and LA. The mortality of J2 was 100% at all concentrations of AA and MX and only at 1.0% and 0.5% of LA, which lowered slightly at 0.2% and greatly at 0.1% of LA. This suggests the nematicidal activity of MX may be mostly derived from AA together with supplementary LA toxicity. MX was applied to chili pepper plants inoculated with about 1,000 J2, for which root-knot gall formations and plant growths were examined 4 weeks after inoculation. The root gall formation was completely inhibited by 0.5% MX and standard and double concentrations of fosthiazate; and inhibited 92.9% and 57.1% by 0.2% and 0.1% MX, respectively. Shoot height, shoot weight, and root weight were not significantly (P ≤ 0.05) different among all treatments and the untreated and non-inoculated controls. All of these results suggest that the mixture of the organic acids may have a potential to be developed as an eco-friendly nematode control agent that needs to be supported by the more nematode control experiments in fields. PMID:25506312

  2. Control of Meloidogyne incognita Using Mixtures of Organic Acids.

    PubMed

    Seo, Yunhee; Kim, Young Ho

    2014-12-01

    This study sought to control the root-knot nematode (RKN) Meloidogyne incognita using benign organo-chemicals. Second-stage juveniles (J2) of RKN were exposed to dilutions (1.0%, 0.5%, 0.2%, and 0.1%) of acetic acid (AA), lactic acid (LA), and their mixtures (MX). The nematode bodies were disrupted severely and moderately by vacuolations in 0.5% of MX and single organic acids, respectively, suggesting toxicity of MX may be higher than AA and LA. The mortality of J2 was 100% at all concentrations of AA and MX and only at 1.0% and 0.5% of LA, which lowered slightly at 0.2% and greatly at 0.1% of LA. This suggests the nematicidal activity of MX may be mostly derived from AA together with supplementary LA toxicity. MX was applied to chili pepper plants inoculated with about 1,000 J2, for which root-knot gall formations and plant growths were examined 4 weeks after inoculation. The root gall formation was completely inhibited by 0.5% MX and standard and double concentrations of fosthiazate; and inhibited 92.9% and 57.1% by 0.2% and 0.1% MX, respectively. Shoot height, shoot weight, and root weight were not significantly (P ≤ 0.05) different among all treatments and the untreated and non-inoculated controls. All of these results suggest that the mixture of the organic acids may have a potential to be developed as an eco-friendly nematode control agent that needs to be supported by the more nematode control experiments in fields. PMID:25506312

  3. 40 CFR 721.5465 - Amine salt of organic acid (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Amine salt of organic acid (generic... Substances § 721.5465 Amine salt of organic acid (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as amine salt of organic acid...

  4. 40 CFR 721.5465 - Amine salt of organic acid (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Amine salt of organic acid (generic... Substances § 721.5465 Amine salt of organic acid (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as amine salt of organic acid...

  5. 40 CFR 721.5465 - Amine salt of organic acid (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Amine salt of organic acid (generic... Substances § 721.5465 Amine salt of organic acid (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as amine salt of organic acid...

  6. 40 CFR 721.5465 - Amine salt of organic acid (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Amine salt of organic acid (generic... Substances § 721.5465 Amine salt of organic acid (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as amine salt of organic acid...

  7. 40 CFR 721.5465 - Amine salt of organic acid (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Amine salt of organic acid (generic... Substances § 721.5465 Amine salt of organic acid (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as amine salt of organic acid...

  8. Simple method of isolating humic acids from organic soils

    NASA Astrophysics Data System (ADS)

    Ahmed, O. H.; Susilawati, K.; Nik Muhamad, A. B.; Khanif, M. Y.

    2009-04-01

    Humic substances particularly humic acids (HA) play a major role in soil conditioning e.g. erosion control, soil cation exchange capacity, complexation of heavy metal ions and pesticides, carbon and nitrogen cycles, plant growth and reduction of ammonia volatilization from urea. Humified substances such as coal, composts, and peat soils have substantial amounts of HA but the isolation of these acids is expensive, laborious, and time consuming. Factors that affect the quality and yield of HA isolated from these materials include extraction, fractionation, and purification periods. This work developed a simple, rapid, and cost effective method of isolating HA from peat soils. There was a quadratic relationship between extraction period and HA yield. Optimum extraction period was estimated at 4 h instead of the usual range of 12 to 48 h. There was no relationship between fractionation period and HA yield. As such 2 h instead of the usual range of 12 to 24 h fractionation period could be considered optimum. Low ash content (5%), remarkable reduction in K, coupled with the fact that organic C, E4/E6, carboxylic COOH, phenolic OH, and total acidity values of the HA were consistent with those reported by other authors suggest that the HA dealt with were free from mineral matter. This was possible because the distilled water used to purify the HA served as Bronsted-Lowry acid during the purification process of the HA. Optimum purification period using distilled waster was 1 h instead of the usual range of 1 and 7 days (uses HF and HCl and dialysis). Humic acids could be isolated from tropical peat soils within 7 h (i.e. 4 h extraction, 2 h fractionation, and 1 h purification) instead of the existing period of 2 and 7 days. This could facilitate the idea of producing organic fertilizers such as ammonium-humate and potassium-humate from humified substances since techniques devised in this study did not alter the true nature of the HA. Besides, the technique is rapid, simple

  9. Formation of organic acids from the gas-phase ozonolysis of terpinolene.

    PubMed

    Ma, Yan; Marston, George

    2009-06-01

    Gas-phase ozonolysis of terpinolene was studied in static chamber experiments using gas chromatography coupled to mass spectrometric and flame ionisation detection to separate and detect products. Two isomers of C(7)-diacids and three isomers of C(7)-aldehydic acids were identified in the condensed phase after derivatisation. Possible mechanisms of formation of these acids were investigated using different OH radical scavengers and relative humidities, and were compared to those reported earlier for the ozonolysis of beta-pinene. In addition, branching ratios for some of the individual reaction steps, e.g. the branching ratio between the two hydroperoxide channels of the C(7)-CI, were deduced from the quantitative product yield data. Branching ratios for POZ decomposition and the stabilisation/decomposition of the C(7-)CI were also obtained from measurements of the C(7) primary carbonyl product. PMID:19458821

  10. Quantification of aldehyde terminated heparin by SEC-MALLS-UV for the surface functionalization of polycaprolactone biomaterials.

    PubMed

    Irvine, Scott A; Steele, Terry W J; Bhuthalingam, Ramya; Li, Min; Boujday, Souhir; Prawirasatya, Melissa; Neoh, Koon Gee; Boey, Freddy Yin Chiang; Venkatraman, Subbu S

    2015-08-01

    A straight forward strategy of heparin surface grafting employs a terminal reactive-aldehyde group introduced through nitrous acid depolymerization. An advanced method that allows simultaneously monitoring of both heparin molar mass and monomer/aldehyde ratio by size exclusion chromatography, multi-angle laser light scattering and UV-absorbance (SEC-MALLS-UV) has been developed to improve upon heparin surface grafting. Advancements over older methods allow quantitative characterization by direct (aldehyde absorbance) and indirect (Schiff-based absorbance) evaluation of terminal functional aldehydes. The indirect quantitation of functional aldehydes through labeling with aniline (and the formation of a Schiff-base) allows independent quantitation of both polymer mass and terminal functional groups with the applicable UV mass extinction coefficients determined. The protocol was subsequently used to synthesize an optimized heparin-aldehyde that had minimal polydispersity (PDI<2) and high reaction yields (yield >60% by mass). The 8 kDa weight averaged molar mass heparin-aldehyde was then grafted on polycaprolactone (PCL), a common implant material. This optimized heparin-aldehyde retained its antithrombin activity, assessed in freshly drawn blood or surface immobilized on PCL films. Anticoagulant activity was equal to or better than the 24 kDa unmodified heparin it was fragmented from. PMID:26052108

  11. Effect of selected aldehydes on the growth and fermentation of ethanologenic Escherichia coli

    SciTech Connect

    Zaldivar, J.; Ingram, L.O.; Martinez, A. |

    1999-10-05

    Bioethanol production from lignocellulosic raw-materials requires the hydrolysis of carbohydrate polymers into a fermentable syrup. During the hydrolysis of hemicellulose with dilute acid, a variety of toxic compounds are produced such as soluble aromatic aldehydes from lignin and furfural from pentose destruction. In this study, the authors have investigated the toxicity of representative aldehydes (furfural, 5-hydroxymethlyfurfural, 4-hydroxybenzaldehyde, syringaldehyde, and vanillin) as inhibitors of growth and ethanol production by ethanologenic derivatives of Escherichia coli B (strains K011 and LY01). Aromatic aldyhydes were at least twice as toxic as furfural of 5-hydroxymethylfurfural on a weight basis. The toxicities of all aldehydes (and ethanol) except furfural were additive when tested in binary combinations. In all cases, combinations with furfural were unexpectedly toxic. Although the potency of these aldehydes was directly related to hydrophobicity indicating a hydrophobic site of action, none caused sufficient membrane damage to allow the leakage of intracellular magnesium even when present at sixfold the concentrations required for growth inhibition. Of the aldehydes tested, only furfural strongly inhibited ethanol production in vitro. A comparison with published results for other microorganisms indicates that LY01 is equivalent or more resistant than other biocatalysts to the aldehydes examined in this study.

  12. Aldose and aldehyde reductases : structure-function studies on the coenzyme and inhibitor-binding sites.

    SciTech Connect

    El-Kabbani, O.; Old, S. E.; Ginell, S. L.; Carper, D. A.; Biosciences Division; Monash Univ.; NIH

    1999-09-03

    PURPOSE: To identify the structural features responsible for the differences in coenzyme and inhibitor specificities of aldose and aldehyde reductases. METHODS: The crystal structure of porcine aldehyde reductase in complex with NADPH and the aldose reductase inhibitor sorbinil was determined. The contribution of each amino acid lining the coenzyme-binding site to the binding of NADPH was calculated using the Discover package. In human aldose reductase, the role of the non-conserved Pro 216 (Ser in aldehyde reductase) in the binding of coenzyme was examined by site-directed mutagenesis. RESULTS: Sorbinil binds to the active site of aldehyde reductase and is hydrogen-bonded to Trp 22, Tyr 50, His 113, and the non-conserved Arg 312. Unlike tolrestat, the binding of sorbinil does not induce a change in the side chain conformation of Arg 312. Mutation of Pro 216 to Ser in aldose reductase makes the binding of coenzyme more similar to that of aldehyde reductase. CONCLUSIONS: The participation of non-conserved active site residues in the binding of inhibitors and the differences in the structural changes required for the binding to occur are responsible for the differences in the potency of inhibition of aldose and aldehyde reductases. We report that the non-conserved Pro 216 in aldose reductase contributes to the tight binding of NADPH.

  13. Vascular Bioactivation of Nitroglycerin by Aldehyde Dehydrogenase-2

    PubMed Central

    Lang, Barbara S.; Gorren, Antonius C. F.; Oberdorfer, Gustav; Wenzl, M. Verena; Furdui, Cristina M.; Poole, Leslie B.; Mayer, Bernd; Gruber, Karl

    2012-01-01

    Aldehyde dehydrogenase-2 (ALDH2) catalyzes the bioactivation of nitroglycerin (glyceryl trinitrate, GTN) in blood vessels, resulting in vasodilation by nitric oxide (NO) or a related species. Because the mechanism of this reaction is still unclear we determined the three-dimensional structures of wild-type (WT) ALDH2 and of a triple mutant of the protein that exhibits low denitration activity (E268Q/C301S/C303S) in complex with GTN. The structure of the triple mutant showed that GTN binds to the active site via polar contacts to the oxyanion hole and to residues 268 and 301 as well as by van der Waals interactions to hydrophobic residues of the catalytic pocket. The structure of the GTN-soaked wild-type protein revealed a thionitrate adduct to Cys-302 as the first reaction intermediate, which was also found by mass spectrometry (MS) experiments. In addition, the MS data identified sulfinic acid as the irreversibly inactivated enzyme species. Assuming that the structures of the triple mutant and wild-type ALDH2 reflect binding of GTN to the catalytic site and the first reaction step, respectively, superposition of the two structures indicates that denitration of GTN is initiated by nucleophilic attack of Cys-302 at one of the terminal nitrate groups, resulting in formation of the observed thionitrate intermediate and release of 1,2-glyceryl dinitrate. Our results shed light on the molecular mechanism of the GTN denitration reaction and provide useful information on the structural requirements for high affinity binding of organic nitrates to the catalytic site of ALDH2. PMID:22988236

  14. Organic acids in cloud water and rainwater at a mountain site in acid rain areas of South China.

    PubMed

    Sun, Xiao; Wang, Yan; Li, Haiyan; Yang, Xueqiao; Sun, Lei; Wang, Xinfeng; Wang, Tao; Wang, Wenxing

    2016-05-01

    To investigate the chemical characteristics of organic acids and to identify their source, cloud water and rainwater samples were collected at Mount Lu, a mountain site located in the acid rain-affected area of south China, from August to September of 2011 and March to May of 2012. The volume-weighted mean (VWM) concentration of organic acids in cloud water was 38.42 μeq/L, ranging from 7.45 to 111.46 μeq/L, contributing to 2.50 % of acidity. In rainwater samples, organic acid concentrations varied from 12.39 to 68.97 μeq/L (VWM of 33.39 μeq/L). Organic acids contributed significant acidity to rainwater, with a value of 17.66 %. Formic acid, acetic acid, and oxalic acid were the most common organic acids in both cloud water and rainwater. Organic acids had an obviously higher concentration in summer than in spring in cloud water, whereas there was much less discrimination in rainwater between the two seasons. The contribution of organic acids to acidity was lower during summer than during spring in both cloud water (2.20 % in summer vs 2.83 % in spring) and rainwater (12.24 % in summer vs 19.89 % in spring). The formic-to-acetic acid ratio (F/A) showed that organic acids were dominated by primary emissions in 71.31 % of the cloud water samples and whole rainwater samples. Positive matrix factorization (PMF) analysis determined four factors as the sources of organic acids in cloud water, including biogenic emissions (61.8 %), anthropogenic emissions (15.28 %), marine emissions (15.07 %) and soil emissions (7.85 %). The findings from this study imply an indispensable role of organic acids in wet deposition, but organic acids may have a limited capacity to increase ecological risks in local environments. PMID:26841776

  15. GRE2 from Scheffersomyces stipitis as an aldehyde reductase contributes tolerance to aldehyde inhibitors derived from lignocellulosic biomass.

    PubMed

    Wang, Xu; Ma, Menggen; Liu, Z Lewis; Xiang, Quanju; Li, Xi; Liu, Na; Zhang, Xiaoping

    2016-08-01

    Scheffersomyces (Pichia) stipitis is one of the most promising yeasts for industrial bioethanol production from lignocellulosic biomass. S. stipitis is able to in situ detoxify aldehyde inhibitors (such as furfural and 5-hydroxymethylfurfural (HMF)) to less toxic corresponding alcohols. However, the reduction enzymes involved in this reaction remain largely unknown. In this study, we reported that an uncharacterized open reading frame PICST_72153 (putative GRE2) from S. stipitis was highly induced in response to furfural and HMF stresses. Overexpression of this gene in Saccharomyces cerevisiae improved yeast tolerance to furfural and HMF. GRE2 was identified as an aldehyde reductase which can reduce furfural to FM with either NADH or NADPH as the co-factor and reduce HMF to FDM with NADPH as the co-factor. This enzyme can also reduce multiple aldehydes to their corresponding alcohols. Amino acid sequence analysis indicated that it is a member of the subclass "intermediate" of the short-chain dehydrogenase/reductase (SDR) superfamily. Although GRE2 from S. stipitis is similar to GRE2 from S. cerevisiae in a three-dimensional structure, some differences were predicted. GRE2 from S. stipitis forms loops at D133-E137 and T143-N145 locations with two α-helices at E154-K157 and E252-A254 locations, different GRE2 from S. cerevisiae with an α-helix at D133-E137 and a β-sheet at T143-N145 locations, and two loops at E154-K157 and E252-A254 locations. This research provided guidelines for the study of other SDR enzymes from S. stipitis and other yeasts on tolerant mechanisms to aldehyde inhibitors derived from lignocellulosic biomass. PMID:27003269

  16. HPLC method for the simultaneous quantification of the major organic acids in Angeleno plum fruit

    NASA Astrophysics Data System (ADS)

    Wang, Yanwei; Wang, Jing; Cheng, Wei; Zhao, Zhilei; Cao, Jiankang

    2014-08-01

    A method was developed to profile major organic acids in Angeleno fruit by high performance liquid chromatography. Organic acids in plum were extracted by water with ultra- sonication at 50°C for 30 min. The extracts were chromatographed on Waters Atlantis T3 C18 column (4.6 mm×250 mm, 5 μm) with 0.01mol/L sulfuric acid and water as mobile phase, and flow rate was 0.5 ml/min. The column temperature was 40C, and chromatography was monitored by a diode array detector at 210 nm. The result showed that malic acid, citric acid, tartaric acid, oxalic acid, pyruvic acid, acetic acid, succinic acid in Angeleno plum, and the malic acid was the major organic acids. The coefficient of determination of the standard calibration curve is R2 > 0.999. The organic acids recovery ranged from 99.11% for Malic acid to 106.70% for Oxalic acid, and CV (n=6) ranged from 0.95% for Malic acid to 6.23% for Oxalic acid, respectively. The method was accurate, sensitive and feasible in analyzing the organic acids in Angeleno plum.

  17. [Fatty aldehydes of the plasmalogenic form of phosphatidylethanolamine in the vertebrate brain].

    PubMed

    Kruglova, E E

    1979-01-01

    Studies have been made on the composition of fatty aldehydes of plasmalogen form of ethanolamine phospholipid in the brain of 28 fish species (13 cartilaginous and 15 teleost species, exhibiting different level of organization of the nervous system, marine and freshwater, dwelling in different habitats), as well as in the brain of other vertebrates. It was found that in all primitive species of cartilaginous fish high degree of unsaturation of fatty aldehydes is observed; in higher species the degree of unsaturation is much lower. The highest degree of unsaturation of fatty aldehydes was demonstrated for abyssal species of cartilaginous and teleost fishes. In warm-water species which dwell in the upper layers, unlike all other fishes investigated, almost all fatty aldehydes are saturated. The ratio of unsaturated and saturated fatty aldehydes in fish brain depends on the entity of phylogenetic and ecological factors. Studies on other vertebrates show that in warm-blooded animals saturated fatty aldehydes predominate, whereas in cold-blooded-unsaturated ones are more abundant. PMID:314210

  18. IUPAC-NIST Solubility Data Series. 99. Solubility of Benzoic Acid and Substituted Benzoic Acids in Both Neat Organic Solvents and Organic Solvent Mixtures

    NASA Astrophysics Data System (ADS)

    Acree, William E.

    2013-09-01

    Solubility data are compiled and reviewed for benzoic acid and 63 substituted benzoic acids dissolved in neat organic solvents and well-defined binary and ternary organic solvent mixtures. The compiled solubility data were retrieved from the published chemical and pharmaceutical literature covering the period from 1900 to the beginning of 2013.

  19. Carbohydrate, Organic Acid, and Amino Acid Composition of Bacteroids and Cytosol from Soybean Nodules 1

    PubMed Central

    Streeter, John G.

    1987-01-01

    Metabolites in Bradyrhizobium japonicum bacteroids and in Glycine max (L.) Merr. cytosol from root nodules were analyzed using an isolation technique which makes it possible to estimate and correct for changes in concentration which may occur during bacteroid isolation. Bacteroid and cytosol extracts were fractionated on ion-exchange columns and were analyzed for carbohydrate composition using gas-liquid chromatography and for organic acid and amino acid composition using high performance liquid chromatography. Analysis of organic acids in plant tissues as the phenacyl derivatives is reported for the first time and this approach revealed the presence of several unknown organic acids in nodules. The time required for separation of bacteroids and cytosol was varied, and significant change in concentration of individual compounds during the separation of the two fractions was estimated by calculating the regression of concentration on time. When a statistically significant slope was found, the true concentration was estimated by extrapolating the regression line to time zero. Of 78 concentration estimates made, there was a statistically significant (5% level) change in concentration during sample preparation for only five metabolites: glucose, sucrose, and succinate in the cytosol and d-pinitol and serine in bacteroids. On a mass basis, the major compounds in bacteroids were (descending order of concentration): myo-inositol, d-chiro-inositol, α,α-trehalose, sucrose, aspartate, glutamate, d-pinitol, arginine, malonate, and glucose. On a proportional basis (concentration in bacteroid as percent of concentration in bacteroid + cytosol fractions), the major compounds were: α-aminoadipate (94), trehalose (66), lysine (58), and arginine (46). The results indicate that metabolite concentrations in bacteroids can be reliably determined. PMID:16665774

  20. Effects of CO2 enrichment on the metabolism of soluble amino acids and organic acids in barley primary leaves

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Responses of soluble amino acids and organic acids to CO2 enrichment were determined with barley primary leaves (Hordeum vulgare L. cv. Brant) grown in controlled environment chambers. Total soluble amino acids were enhanced 33% by CO2 enrichment when determined 9 days after sowing (DAS). However,...

  1. Hormonal Regulation of Organic and Phosphoric Acid Release by Barley Aleurone Layers and Scutella.

    PubMed Central

    Drozdowicz, Y. M.; Jones, R. L.

    1995-01-01

    The release of acid from the aleurone layer and scutellum of barley (Hordeum vulgare L. cv Himalaya) was investigated. Aleurone layers isolated from mature barley grains acidify the external medium by releasing organic and phosphoric acids. Gibberellic acid and abscisic acid stimulate acid release 2-fold over control tissue incubated in 10 mM CACl2. Gibberellic acid causes medium acidification by stimulating the release of phosphoric and citric acids, whereas abscisic acid stimulates the release of malic acid. The accumulation of these acids in the incubation medium buffers the medium against changes in pH, particularly between pH 4 and 5. The amounts of amino acids that accumulate in the medium are low (2-12 nmol/layer) compared to other organic and phosphoric acids (100-500 nmol/layer). The scutellum does not play a major role in medium acidification but participates in the uptake of organic acids. The organic acid composition of the starchy endosperm changes after 3 d of imbibition; malic, succinic, and lactic acids decrease, whereas citric and phosphoric acids remain unchanged or increase. These results indicate that during postgerminative growth, the acidity of the starchy endosperm is maintained by acid production by the aleurone layer. PMID:12228509

  2. Quantification of aldehydes emissions from alternative and renewable aviation fuels using a gas turbine engine

    NASA Astrophysics Data System (ADS)

    Li, Hu; Altaher, Mohamed A.; Wilson, Chris W.; Blakey, Simon; Chung, Winson; Rye, Lucas

    2014-02-01

    In this research three renewable aviation fuel blends including two HEFA (Hydrotreated Ester and Fatty Acid) blends and one FAE (Fatty Acids Ethyl Ester) blend with conventional Jet A-1 along with a GTL (Gas To Liquid) fuel have been tested for their aldehydes emissions on a small gas turbine engine. Three strong ozone formation precursors: formaldehyde, acetaldehyde and acrolein were measured in the exhaust at different operational modes and compared to neat Jet A-1. The aim is to assess the impact of renewable and alternative aviation fuels on aldehydes emissions from aircraft gas turbine engines so as to provide informed knowledge for the future deployment of new fuels in aviation. The results show that formaldehyde was a major aldehyde species emitted with a fraction of around 60% of total measured aldehydes emissions for all fuels. Acrolein was the second major emitted aldehyde species with a fraction of ˜30%. Acetaldehyde emissions were very low for all the fuels and below the detention limit of the instrument. The formaldehyde emissions at cold idle were up to two to threefold higher than that at full power. The fractions of formaldehyde were 6-10% and 20% of total hydrocarbon emissions in ppm at idle and full power respectively and doubled on a g kg-1-fuel basis.

  3. Recoded organisms engineered to depend on synthetic amino acids.

    PubMed

    Rovner, Alexis J; Haimovich, Adrian D; Katz, Spencer R; Li, Zhe; Grome, Michael W; Gassaway, Brandon M; Amiram, Miriam; Patel, Jaymin R; Gallagher, Ryan R; Rinehart, Jesse; Isaacs, Farren J

    2015-02-01

    Genetically modified organisms (GMOs) are increasingly used in research and industrial systems to produce high-value pharmaceuticals, fuels and chemicals. Genetic isolation and intrinsic biocontainment would provide essential biosafety measures to secure these closed systems and enable safe applications of GMOs in open systems, which include bioremediation and probiotics. Although safeguards have been designed to control cell growth by essential gene regulation, inducible toxin switches and engineered auxotrophies, these approaches are compromised by cross-feeding of essential metabolites, leaked expression of essential genes, or genetic mutations. Here we describe the construction of a series of genomically recoded organisms (GROs) whose growth is restricted by the expression of multiple essential genes that depend on exogenously supplied synthetic amino acids (sAAs). We introduced a Methanocaldococcus jannaschii tRNA:aminoacyl-tRNA synthetase pair into the chromosome of a GRO derived from Escherichia coli that lacks all TAG codons and release factor 1, endowing this organism with the orthogonal translational components to convert TAG into a dedicated sense codon for sAAs. Using multiplex automated genome engineering, we introduced in-frame TAG codons into 22 essential genes, linking their expression to the incorporation of synthetic phenylalanine-derived amino acids. Of the 60 sAA-dependent variants isolated, a notable strain harbouring three TAG codons in conserved functional residues of MurG, DnaA and SerS and containing targeted tRNA deletions maintained robust growth and exhibited undetectable escape frequencies upon culturing ∼10(11) cells on solid media for 7 days or in liquid media for 20 days. This is a significant improvement over existing biocontainment approaches. We constructed synthetic auxotrophs dependent on sAAs that were not rescued by cross-feeding in environmental growth assays. These auxotrophic GROs possess alternative genetic codes that

  4. Qualitative urinary organic acid analysis: 10 years of quality assurance.

    PubMed

    Peters, Verena; Bonham, James R; Hoffmann, Georg F; Scott, Camilla; Langhans, Claus-Dieter

    2016-09-01

    Over the last 10 years, a total of 90 urine samples from patients with metabolic disorders and controls were circulated to different laboratories in Europe and overseas, starting with 67 laboratories in 2005 and reaching 101 in 2014. The participants were asked to analyse the samples in their usual way and to prepare a report as if to a non-specialist pediatrician. The performance for the detection of fumarase deficiency, glutaric aciduria type I, isovaleric aciduria, methylmalonic aciduria, mevalonic aciduria, phenylketonuria and propionic aciduria was excellent (98-100 %). Over the last few years, detection has clearly improved for tyrosinaemia type I (39 % in 2008 to over 80 % in 2011/2014), maple syrup urine disease (85 % in 2005 to 98 % in 2012), hawkinsinuria (62 % in 2010 to 88 % in 2014), aminoacylase I deficiency (43 % in 2009 to 73 % in 2012) and 3-methylcrotonyl-CoA carboxylase deficiency (60 % in 2005 to 93 % by 2011). Normal urines were mostly considered as normal (83-100 %), but laboratories often made additional diagnostic suggestions. When the findings were unambiguous, the reports were mostly clear. However, when they were less obvious, the content and quality of reports varied greatly. Repetition of organic acid measurements on a fresh sample was rarely suggested, while more complex or invasive diagnostic strategies, including further metabolic screening or biopsy were recommended. Surprisingly very few participants suggested referral from the general paediatrician to a specialist metabolic centre to confirm a diagnosis and, if applicable, to initiate treatment despite evidence suggesting that this improves the outcome for patients with inherited metabolic disorders. The reliability of qualitative organic acid analysis has improved over the last few years. However, several aspects of reporting to non-specialists may need discussion and clinicians need to be aware of the uncertainty inherent in all forms of laboratory diagnostic

  5. Use of Cavity Ring Down Spectroscopy to Characterize Organic Acids and Aerosols Emitted in Biomass Burning

    NASA Astrophysics Data System (ADS)

    Bililign, Solomon; Fiddler, Marc; Singh, Sujeeta

    2012-02-01

    One poorly understood, but significant class of volatile organic compounds (VOC) present in biomass burning is gas-phase organic acids and inorganic acids. These acids are extremely difficult to measure because of their adsorptive nature. Particulates and aerosols are also produced during biomass burning and impact the radiation budget of the Earth and, hence, impact global climate. Use cavity ring down spectroscopy (CRD) to measure absorption cross sections for OH overtone induced photochemistry in some organic acids (acetic acid and peracetic acid) will be presented and planed measurements of optical properties of aerosols composed of mixtures of different absorbing and non-absorbing species using CRD will be discussed.

  6. Water-enhanced solubility of carboxylic acids in organic solvents and its applications to extraction processes

    SciTech Connect

    Starr, J.N.; King, C.J.

    1991-11-01

    The solubilities of carboxylic acids in certain organic solvents increase remarkably with an increasing amount of water in the organic phase. This phenomenon leads to a novel extract regeneration process in which the co-extracted water is selectively removed from an extract, and the carboxylic acid precipitates. This approach is potentially advantageous compared to other regeneration processes because it removes a minor component of the extract in order to achieve a large recovery of acid from the extract. Carboxylic acids of interest include adipic acid, fumaric acid, and succinic acid because of their low to moderate solubilities in organic solvents. Solvents were screened for an increase in acid solubility with increased water concentration in the organic phase. Most Lewis-base solvents were found to exhibit this increased solubility phenomena. Solvents that have a carbonyl functional group showed a very large increase in acid solubility. 71 refs., 52 figs., 38 tabs.

  7. Hydrogelation and Crystallization of Sodium Deoxycholate Controlled by Organic Acids.

    PubMed

    Li, Guihua; Hu, Yuanyuan; Sui, Jianfei; Song, Aixin; Hao, Jingcheng

    2016-02-16

    The gelation and crystallization behavior of a biological surfactant, sodium deoxycholate (NaDC), mixed with l-taric acid (L-TA) in water is described in detail. With the variation of molar ratio of L-TA to NaDC (r = nL-TA/nNaDC) and total concentration of the mixtures, the transition from sol to gel was observed. SEM images showed that the density of nanofibers gradually increases over the sol-gel transition. The microstructures of the hydrogels are three-dimensional networks of densely packed nanofibers with lengths extending to several micrometers. One week after preparation, regular crystallized nanospheres formed along the length of the nanofibers, and it was typical among the transparent hydrogels induced by organic acids with pKa1 value <3.4. Small-angle X-ray diffraction demonstrated differences in the molecular packing between transparent and turbid gels, indicating a variable hydrogen bond mode between NaDC molecules. PMID:26783993

  8. Effects of pH adjustment and sodium ions on sour taste intensity of organic acids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Protonated organic acid species have been shown to be the primary stimuli responsible for sour taste of organic acids. However, we have observed that sour taste may be modulated when the pH of acid solutions is raised using sodium hydroxide. Objectives were to evaluate the effect of pH adjustment on...

  9. Isolation of organic acids from large volumes of water by adsorption chromatography

    USGS Publications Warehouse

    Aiken, George R.

    1984-01-01

    The concentrations of dissolved organic carbon from most natural waters ranges from 1 to 20 milligrams carbon per liter, of which approximately 75 percent are organic acids. These acids can be chromatographically fractionated into hydrophobic organic acids, such as humic substances, and hydrophilic organic acids. To effectively study any of these organic acids, they must be isolated from other organic and inorganic species, and concentrated. Usually, large volumes of water must be processed to obtain sufficient quantities of material, and adsorption chromatography on synthetic, macroporous resins has proven to be a particularly effective method for this purpose. The use of the nonionic Amberlite XAD-8 and Amberlite XAD-4 resins and the anion exchange resin Duolite A-7 for isolating and concentrating organic acids from water is presented.

  10. Polyetherurethane oligomers with aldehyde groups as additives for lubricating oils

    SciTech Connect

    Nikolaev, V.N.; Abramov, E.G.; Tenyushev, A.I.

    1995-01-01

    Polyetherurethane oligomers with aldehyde groups, which we synthesized from polyoxypropylene diols (molecular weight 500, 1000, 1500, 2000, or 3000) with toluene diisocyanate and salicylaldehyde, are of interest as additives for lubricating oils. The effects of these oligomers on the service properties and physicochemical characteristics of lubricating oils were investigated by methods prreviously described. As the lube base stocks we used castor oil, a polyoxypropylene diol and a polyethoxysiloxane. The oligomers are readily soluble in organic solvents and in the lube base stocks, and their solutions are stable during storage and use. We found that the optimal concentration of oligomers is 5%, providing the best lubricating properties, in particular the best antiwear properties.

  11. Nuclear alkylated pyridine aldehyde polymers and conductive compositions thereof

    NASA Technical Reports Server (NTRS)

    Rembaum, A.; Singer, S. (Inventor)

    1970-01-01

    A thermally stable, relatively conductive polymer was disclosed. The polymer was synthesized by condensing in the presence of catalyst a 2, 4, or 6 nuclear alklylated 2, 3, or 4 pyridine aldehyde or quaternary derivatives thereof to form a polymer. The pyridine groups were liked by olefinic groups between 2-4, 2-6, 2-3, 3-4, 3-6 or 4-6 positions. Conductive compositions were prepared by dissolving the quaternary polymer and an organic charge transfer complexing agent such as TCNQ in a mutual solvent such as methanol.

  12. Evaluation of organic acids as fuel cell electrolytes

    SciTech Connect

    Ahmad, J.; Nguyen, T.H.; Foley, R.T.

    1981-11-01

    The electrochemical behavior of methanesulfonic acid, ethanesulfonic acid, and sulfoacetic acid as fuel cell electrolytes was studied in half-cell at various temperatures. The rate of the electro-oxidation of hydrogen at 115/degree/C was very high in methanesulfonic acid. The rate of the electro-oxidation of propane in all three acids was low even at 135/degree/C. Further, there is evidence for adsorption of these acids on the platinum electrode. It is concluded that anhydrous sulfonic acids are not good electrolytes; water solutions are required. Sulfonic acids containing unprotected carbon-hydrogen bonds are adsorbed on platinum and probably decompose during electrolysis. 9 refs.

  13. Intercalation of Aldehydes into Vanadyl Phosphate

    NASA Astrophysics Data System (ADS)

    Melánová, Klára; Beneš, Ludvík.; Zima, Vítězslav; Votinský, Jiří

    2001-02-01

    Intercalates of VOPO4 with several aliphatic aldehydes, benzaldehyde, and 4-methylbenzaldehyde were prepared and characterized by thermogravimetric analysis, X-ray diffractometry, and IR and UV-vis spectroscopies. Aliphatic aldehyde intercalates are unstable and the guests undergo aldol condensation and oxidation. The arrangement of the guest molecules in the interlayer space of the host is discussed. A part of aliphatic aldehydes is anchored to the host layers by coordination of their carbonyl oxygen to the vanadium atom; the rest is probably bonded by weak van der Waals forces. In the benzaldehyde and 4-methylbenzaldehyde intercalates, all guest molecules are coordinated to the vanadium atoms with their benzene rings perpendicular to the sheets of the host.

  14. Betaine aldehyde dehydrogenase isozymes of spinach

    SciTech Connect

    Hanson, A.D.; Weretilnyk, E.A.; Weigel, P.

    1986-04-01

    Betaine is synthesized in spinach chloroplasts via the pathway Choline ..-->.. Betaine Aldehyde ..-->.. Betaine; the second step is catalyzed by betaine aldehyde dehydrogenase (BADH). The subcellular distribution of BADH was determined in leaf protoplast lysates; BADH isozymes were separated by 6-9% native PAGE. The chloroplast stromal fraction contains a single BADH isozyme (number1) that accounts for > 80% of the total protoplast activity; the extrachloroplastic fraction has a minor isozyme (number2) which migrates more slowly than number1. Both isozymes appear specific for betaine aldehyde, are more active with NAD than NADP, and show a ca. 3-fold activity increase in salinized leaves. The phenotype of a natural variant of isozyme number1 suggests that the enzyme is a dimer.

  15. Dynamics of three organic acids (malic, acetic and succinic acid) in sunflower exposed to cadmium and lead.

    PubMed

    Niu, Zhixin; Li, Xiaodong; Sun, Lina; Sun, Tieheng

    2013-01-01

    Sunflower (Helianthus annuus L.) has been considered as a good candidate for bioaccumulation of heavy metals. In the present study, sunflower was used to enrich the cadmium and lead in sand culture during 90 days. Biomass, Cd and Pb uptake, three organic acids and pH in cultures were investigated. Results showed that the existence of Cd and Pb showed different interactions on the organic acids exudation. In single Cd treatments, malic and acetic acids in Cd10 showed an incremental tendency with time. In the mixed treatments of Cd and Pb, malic acids increased when 10 and 40 mg x L(-1) Cd were added into Pb50, but acetic acids in Pb50 were inhibited by Cd addition. The Cd10 supplied in Pb10 stimulated the secretion of malic and succinic acids. Moreover, the Cd or Pb uptake in sunflower showed various correlations with pH and some organic acids, which might be due to the fact that the Cd and Pb interfere with the organic acids secretion in rhizosphere of sunflower, and the changes of organic acids altered the form and bioavailability of Cd and Pb in cultures conversely. PMID:23819268

  16. Uptake of Ambient Organic Gases to Acidic Sulfate Aerosols

    NASA Astrophysics Data System (ADS)

    Liggio, J.; Li, S.

    2009-05-01

    The formation of secondary organic aerosols (SOA) in the atmosphere has been an area of significant interest due to its climatic relevance, its effects on air quality and human health. Due largely to the underestimation of SOA by regional and global models, there has been an increasing number of studies focusing on alternate pathways leading to SOA. In this regard, recent work has shown that heterogeneous and liquid phase reactions, often leading to oligomeric material, may be a route to SOA via products of biogenic and anthropogenic origin. Although oligomer formation in chamber studies has been frequently observed, the applicability of these experiments to ambient conditions, and thus the overall importance of oligomerization reactions remain unclear. In the present study, ambient air is drawn into a Teflon smog chamber and exposed to acidic sulfate aerosols which have been formed in situ via the reaction of SO3 with water vapor. The aerosol composition is measured with a High Resolution Aerodyne Aerosol Mass Spectrometer (HR-ToF-AMS), and particle size distributions are monitored with a scanning mobility particle sizer (SMPS). The use of ambient air and relatively low inorganic particle loading potentially provides clearer insight into the importance of heterogeneous reactions. Results of experiments, with a range of sulfate loadings show that there are several competing processes occurring on different timescales. A significant uptake of ambient organic gases to the particles is observed immediately followed by a slow shift towards higher m/z over a period of several hours indicating that higher molecular weight products (possibly oligomers) are being formed through a reactive process. The results suggest that heterogeneous reactions can occur with ambient organic gases, even in the presence of ammonia, which may have significant implications to the ambient atmosphere where particles may be neutralized after their formation.

  17. Leaching of organic acids from macromolecular organic matter by non-supercritical CO2

    NASA Astrophysics Data System (ADS)

    Sauer, P.; Glombitza, C.; Kallmeyer, J.

    2012-04-01

    The storage of CO2 in underground reservoirs is discussed controversly in the scientific literature. The worldwide search for suitable storage formations also considers coal-bearing strata. CO2 is already injected into seams for enhanced recovery of coal bed methane. However, the effects of increased CO2 concentration, especially on organic matter rich formations, are rarely investigated. The injected CO2 will dissolve in the pore water, causing a decrease in pH and resulting in acidic formation waters. Huge amounts of low molecular weight organic acids (LMWOAs) are chemically bound to the macromolecular matrix of sedimentary organic matter and may be liberated by hydrolysis, which is enhanced by the acidic porewater. Recent investigations outlined the importance of LMWOAs as a feedstock for microbial life in the subsurface [1]. Therefore, injection of CO2 into coal formations may result in enhanced nutrient supply for subsurface microbes. To investigate the effect of high concentrations of dissolved CO2 on the release of LMWOAs from coal we developed an inexpensive high-pressure high temperature system that allows manipulating the partial pressure of dissolved gases at pressures and temperatures up to 60 MPa and 120° C, respectively. In a reservoir vessel, gases are added to saturate the extraction medium to the desired level. Inside the extraction vessel hangs a flexible and inert PVDF sleeve (polyvinylidene fluoride, almost impermeable for gases), holding the sample and separating it from the pressure fluid. The flexibility of the sleeve allows for subsampling without loss of pressure. Coal samples from the DEBITS-1 well, Waikato Basin, NZ (R0 = 0.29, TOC = 30%). were extracted at 90° C and 5 MPa, either with pure or CO2-saturated water. Subsamples were taken at different time points during the extraction. The extracted LMWOAs such as formate, acetate and oxalate were analysed by ion chromatography. Yields of LMWOAs were higher with pure water than with CO2

  18. The Pivotal Role of Aldehyde Toxicity in Autism Spectrum Disorder: The Therapeutic Potential of Micronutrient Supplementation

    PubMed Central

    Jurnak, Frances

    2015-01-01

    Autism spectrum disorder (ASD) is characterized by social and communication impairments as well as by restricted, repetitive patterns of behavior and interests. Genomic studies have not revealed dominant genetic errors common to all forms of ASD. So ASD is assumed to be a complex disorder due to mutations in hundreds of common variants. Other theories argue that spontaneous DNA mutations and/or environmental factors contribute to as much as 50% of ASD. In reviewing potential genetic linkages between autism and alcoholism, it became apparent that all theories of ASD are consistent with aldehyde toxicity, in which endogenous and exogenous aldehydes accumulate as a consequence of mutations in key enzymes. Aldehyde toxicity is characterized by cell-localized, micronutrient deficiencies in sulfur-containing antioxidants, thiamine (B1), pyridoxine (B6), folate, Zn2+, possibly Mg2+, and retinoic acid, causing oxidative stress and a cascade of metabolic disturbances. Aldehydes also react with selective cytosolic and membrane proteins in the cell of origin; then some types migrate to damage neighboring cells. Reactive aldehydes also form adducts with DNA, selectively mutating bases and inducing strand breakage. This article reviews the relevant genomic, biochemical, and nutritional literature, which supports the central hypothesis that most ASD symptoms are consistent with symptoms of aldehyde toxicity. The hypothesis represents a paradigm shift in thinking and has profound implications for clinical detection, treatment, and even prevention of ASD. Insight is offered as to which neurologically afflicted children might successfully be treated with micronutrients and which children are unlikely to be helped. The aldehyde toxicity hypothesis likely applies to other neurological disorders. PMID:27330305

  19. Synthesis and accumulation of aromatic aldehydes in an engineered strain of Escherichia coli.

    PubMed

    Kunjapur, Aditya M; Tarasova, Yekaterina; Prather, Kristala L J

    2014-08-20

    Aromatic aldehydes are useful in numerous applications, especially as flavors, fragrances, and pharmaceutical precursors. However, microbial synthesis of aldehydes is hindered by rapid, endogenous, and redundant conversion of aldehydes to their corresponding alcohols. We report the construction of an Escherichia coli K-12 MG1655 strain with reduced aromatic aldehyde reduction (RARE) that serves as a platform for aromatic aldehyde biosynthesis. Six genes with reported activity on the model substrate benzaldehyde were rationally targeted for deletion: three genes that encode aldo-keto reductases and three genes that encode alcohol dehydrogenases. Upon expression of a recombinant carboxylic acid reductase in the RARE strain and addition of benzoate during growth, benzaldehyde remained in the culture after 24 h, with less than 12% conversion of benzaldehyde to benzyl alcohol. Although individual overexpression results demonstrated that all six genes could contribute to benzaldehyde reduction in vivo, additional experiments featuring subset deletion strains revealed that two of the gene deletions were dispensable under the conditions tested. The engineered strain was next investigated for the production of vanillin from vanillate and succeeded in preventing formation of the byproduct vanillyl alcohol. A pathway for the biosynthesis of vanillin directly from glucose was introduced and resulted in a 55-fold improvement in vanillin titer when using the RARE strain versus the wild-type strain. Finally, synthesis of the chiral pharmaceutical intermediate L-phenylacetylcarbinol (L-PAC) was demonstrated from benzaldehyde and glucose upon expression of a recombinant mutant pyruvate decarboxylase in the RARE strain. Beyond allowing accumulation of aromatic aldehydes as end products in E. coli, the RARE strain expands the classes of chemicals that can be produced microbially via aldehyde intermediates. PMID:25076127

  20. Identification and Characterization of an Antennae-Specific Aldehyde Oxidase from the Navel Orangeworm

    PubMed Central

    Choo, Young-Moo; Pelletier, Julien; Atungulu, Elizabeth; Leal, Walter S.

    2013-01-01

    Antennae-specific odorant-degrading enzymes (ODEs) are postulated to inactivate odorant molecules after they convey their signal. Different classes of insect ODEs are specific to esters, alcohols, and aldehydes – the major functional groups of female-produced, hydrophobic sex pheromones from moth species. Esterases that rapidly inactive acetate and other esters have been well-studied, but less is known about aldehyde oxidases (AOXs). Here we report cloning of an aldehyde oxidase, AtraAOX2, from the antennae of the navel orangeworm (NOW), Amyelois transitella, and the first activity characterization of a recombinant insect AOX. AtraAOX2 gene spans 3,813 bp and encodes a protein with 1,270 amino acid residues. AtraAOX2 cDNA was expressed in baculovirus-infected insect Sf21 cells as a ≈280 kDa homodimer with 140 kDa subunits. Recombinant AtraAOX2 degraded Z11Z13–16Ald and plant volatile aldehydes as substrates. However, as expected for aldehyde oxidases, recombinant AtraAOX2 did not show specificity for Z11Z13–16Ald, the main constituent of the sex pheromone, but showed high activity for plant volatile aldehydes. Our data suggest AtraAOX2 might be involved in degradation of a diversity of aldehydes including sex pheromones, plant-derived semiochemicals, and chemical cues for oviposition sites. Additionally, AtraAOX2 could protect the insect's olfactory system from xenobiotics, including pesticides that might reach the sensillar lymph surrounding the olfactory receptor neurons. PMID:23826341

  1. Evans-Tishchenko coupling of heteroaryl aldehydes.

    PubMed

    Dorgan, Philip D; Durrani, Jamie; Cases-Thomas, Manuel J; Hulme, Alison N

    2010-11-01

    The low-temperature Evans-Tishchenko coupling of a range of functionalized heteroaryl aldehydes with β-hydroxy ketones in the presence of a Sm(III) catalyst has been achieved with high yields (90-99%) and good to excellent diastereoselectivity (90:10 → 95:5 dr). However, at room temperature a retro-aldol aldol-Tishchenko reaction was found to compete with the desired Evans-Tishchenko reaction. Identification of these byproducts has allowed the corresponding aldol-Tishchenko reaction to be optimized for several heteroaryl aldehydes. PMID:20929205

  2. The Oxidative Fermentation of Ethanol in Gluconacetobacter diazotrophicus Is a Two-Step Pathway Catalyzed by a Single Enzyme: Alcohol-Aldehyde Dehydrogenase (ADHa)

    PubMed Central

    Gómez-Manzo, Saúl; Escamilla, José E.; González-Valdez, Abigail; López-Velázquez, Gabriel; Vanoye-Carlo, América; Marcial-Quino, Jaime; de la Mora-de la Mora, Ignacio; Garcia-Torres, Itzhel; Enríquez-Flores, Sergio; Contreras-Zentella, Martha Lucinda; Arreguín-Espinosa, Roberto; Kroneck, Peter M. H.; Sosa-Torres, Martha Elena

    2015-01-01

    Gluconacetobacter diazotrophicus is a N2-fixing bacterium endophyte from sugar cane. The oxidation of ethanol to acetic acid of this organism takes place in the periplasmic space, and this reaction is catalyzed by two membrane-bound enzymes complexes: the alcohol dehydrogenase (ADH) and the aldehyde dehydrogenase (ALDH). We present strong evidence showing that the well-known membrane-bound Alcohol dehydrogenase (ADHa) of Ga. diazotrophicus is indeed a double function enzyme, which is able to use primary alcohols (C2–C6) and its respective aldehydes as alternate substrates. Moreover, the enzyme utilizes ethanol as a substrate in a reaction mechanism where this is subjected to a two-step oxidation process to produce acetic acid without releasing the acetaldehyde intermediary to the media. Moreover, we propose a mechanism that, under physiological conditions, might permit a massive conversion of ethanol to acetic acid, as usually occurs in the acetic acid bacteria, but without the transient accumulation of the highly toxic acetaldehyde. PMID:25574602

  3. The oxidative fermentation of ethanol in Gluconacetobacter diazotrophicus is a two-step pathway catalyzed by a single enzyme: alcohol-aldehyde Dehydrogenase (ADHa).

    PubMed

    Gómez-Manzo, Saúl; Escamilla, José E; González-Valdez, Abigail; López-Velázquez, Gabriel; Vanoye-Carlo, América; Marcial-Quino, Jaime; de la Mora-de la Mora, Ignacio; Garcia-Torres, Itzhel; Enríquez-Flores, Sergio; Contreras-Zentella, Martha Lucinda; Arreguín-Espinosa, Roberto; Kroneck, Peter M H; Sosa-Torres, Martha Elena

    2015-01-01

    Gluconacetobacter diazotrophicus is a N2-fixing bacterium endophyte from sugar cane. The oxidation of ethanol to acetic acid of this organism takes place in the periplasmic space, and this reaction is catalyzed by two membrane-bound enzymes complexes: the alcohol dehydrogenase (ADH) and the aldehyde dehydrogenase (ALDH). We present strong evidence showing that the well-known membrane-bound Alcohol dehydrogenase (ADHa) of Ga. diazotrophicus is indeed a double function enzyme, which is able to use primary alcohols (C2-C6) and its respective aldehydes as alternate substrates. Moreover, the enzyme utilizes ethanol as a substrate in a reaction mechanism where this is subjected to a two-step oxidation process to produce acetic acid without releasing the acetaldehyde intermediary to the media. Moreover, we propose a mechanism that, under physiological conditions, might permit a massive conversion of ethanol to acetic acid, as usually occurs in the acetic acid bacteria, but without the transient accumulation of the highly toxic acetaldehyde. PMID:25574602

  4. Remarkable Impact of Acidic Ginsenosides and Organic Acids on Ginsenoside Transformation from Fresh Ginseng to Red Ginseng.

    PubMed

    Liu, Zhi; Xia, Juan; Wang, Chong-Zhi; Zhang, Jin-Qiu; Ruan, Chang-Chun; Sun, Guang-Zhi; Yuan, Chun-Su

    2016-07-01

    Panax ginseng contains many chemical components, including acidic ginsenosides and organic acids. However, whether these acidic substances play a role in ginsenoside transformation during steaming treatment has not yet been explored. In this paper, the content of neutral ginsenosides, acidic ginsenosides, and their degradation products in unsteamed and steamed P. ginseng were simultaneously quantified by high-performance liquid chromatography. We observed that neutral ginsenosides were converted to rare ginsenosides during the root steaming but not during the individual ginsenoside steaming. In contrast, acidic malonyl ginsenosides released malonic acid and acetic acid through demalonylation, decarboxylation, deacetylation reactions during the steaming at 120 °C. These malonyl ginsenosides not only were converted to rare ginsenosides but also promoted the degradation of neutral ginsenosides. Further studies indicated that a low concentration of organic acid was the determining factor for the ginsenoside conversion. The related mechanisms were deduced to be mainly acidic hydrolysis and dehydration. In summary, acidic ginsenosides and organic acids remarkably affected ginsenoside transformation during the steaming process. Our results provide useful information for precisely understanding the ginsenoside conversion pathways and mechanisms underlying the steaming process. PMID:27295137

  5. Effects of aldehydes and methods of cross-linking on properties of calcium alginate microspheres prepared by emulsification.

    PubMed

    Chan, Lai Wah; Heng, Paul W S

    2002-03-01

    Calcium alginate microspheres were prepared by an emulsification method and cross-linked with various aldehydes using different methods. Methanal and pentanedial produced low aggregation of microspheres while octanal and octadecanal produced the opposite effect. The latter two aldehydes displaced very little calcium ions from the alginate microspheres, indicating that the aggregation was due to the tackiness imparted by the aldehydes to the microsphere surface. Higuchi's model was not applicable to the drug release from microspheres in this study. The microspheres treated with methanal or pentanedial showed comparable dissolution T75% values which were significantly higher than that of the control. In contrast, octanal and octadecanal produced microspheres with lower dissolution T75% values. The drug contents of the microspheres treated with aldehydes were significantly lower than that of the control. There was insignificant interaction between the aldehydes and the drug. However, the aldehydes were found to impart acidity to the aqueous solution to varying extents, resulting in varying drug loss from the microspheres. The properties of the microspheres were also markedly affected by the method of incorporating the aldehyde. Soaking the microspheres in methanal solution produced microspheres with marked aggregation and low drug content. PMID:11808537

  6. Utility of monitoring mycophenolic acid in solid organ transplant patients.

    PubMed Central

    Oremus, Mark; Zeidler, Johannes; Ensom, Mary H H; Matsuda-Abedini, Mina; Balion, Cynthia; Booker, Lynda; Archer, Carolyn; Raina, Parminder

    2008-01-01

    OBJECTIVES To investigate whether monitoring concentrations of mycophenolic acid (MPA) in the serum or plasma of persons who receive a solid organ transplant will result in a lower incidence of transplant rejections and adverse events versus no monitoring of MPA. To investigate whether the incidence of rejection or adverse events differs according to MPA dose or frequency, type of MPA, the form of MPA monitored, the method of MPA monitoring, or sample characteristics. To assess whether monitoring is cost-effective versus no monitoring. DATA SOURCES The following databases were searched from their dates of inception (in brackets) until October 2007: MEDLINE (1966); BIOSIS Previews (1976); EMBASE (1980); Cochrane Database of Systematic Reviews (1995); and Cochrane Central Register of Controlled Trials (1995). REVIEW METHODS Studies identified from the data sources went through two levels of screening (i.e., title and abstract, full text) and the ones that passed were abstracted. Criteria for abstraction included publication in the English language, study design (i.e., randomized controlled trial [RCT], observational study with comparison group, case series), and patient receipt of allograft solid organ transplant. Additionally, any form of MPA had to be measured at least once in the plasma or serum using any method of measurement (e.g., AUC0-12, C0). Furthermore, these measures had to be linked to a health outcome (e.g., transplant rejection). Certain biomarkers (e.g., serum creatinine, glomular filtration rate) and all adverse events were also considered health outcomes. RESULTS The published evidence on MPA monitoring is inconclusive. Direct, head-to-head comparison of monitoring versus no monitoring is limited to one RCT in adult, kidney transplant patients. Inferences about monitoring can be made from some observational studies, although the evidence is equivocal for MPA dose and dose frequency, nonexistent for type of MPA, inconclusive for form of MPA monitored

  7. Effects of organic acids, amino acids and ethanol on the radio-degradation of patulin in an aqueous model system

    NASA Astrophysics Data System (ADS)

    Yun, Hyejeong; Lim, Sangyong; Jo, Cheorun; Chung, Jinwoo; Kim, Soohyun; Kwon, Joong-Ho; Kim, Dongho

    2008-06-01

    The effects of organic acids, amino acids, and ethanol on the radio-degradation of patulin by gamma irradiation in an aqueous model system were investigated. The patulin, dissolved in distilled water at a concentration of 50 ppm, was practically degraded by the gamma irradiation at the dose of 1.0 kGy, while 33% of the patulin remained in apple juice. In the aqueous model system, the radio-degradation of patulin was partially inhibited by the addition of organic acids, amino acids, and ethanol. The proportions of remaining patulin after irradiation with the dose of 1.0 kGy in the 1% solution of malic acid, citric acid, lactic acid, acetic acid, ascorbic acid, and ethanol were 31.4%, 2.3%, 31.2%, 6.1%, 50.8%, and 12.5%, respectively. During 30 days of storage, the remaining patulin was reduced gradually in the solution of ascorbic acid and malic acid compared to being stable in other samples. The amino acids, serine, threonine, and histidine, inhibited the radio-degradation of patulin. In conclusion, it was suggested that 1 kGy of gamma irradiation (recommended radiation doses for radicidation and/or quarantine in fruits) is effective for the reduction of patulin, but the nutritional elements should be considered because the radio-degradation effects are environment dependent.

  8. The Photochemical Isomerization of Maleic to Fumaric Acid: An Undergraduate Organic Chemistry Experiment.

    ERIC Educational Resources Information Center

    Castro, Albert J.; And Others

    1983-01-01

    Describes an undergraduate organic chemistry experiment on the photochemical isomerization of maleic to fumaric acid. Background information, chemical reactions involved, and experimental procedures are included. (JN)

  9. Influence of organic acids on the pH and acid-neutralizing capacity of Adirondack Lakes

    NASA Astrophysics Data System (ADS)

    Munson, R. K.; Gherini, S. A.

    1993-04-01

    Past approaches for evaluating the effects of organic acids on the acid-base characteristics of surface waters have typically treated them solely as weak acids. Analysis of data collected by the Adirondack Lakes Survey Corporation (ALSC) from 1469 lakes throughout the Adirondack region shows that this approach is not valid. While the data indicate that natural organics contain a continuum of acid functional groups, many of which display weak acid characteristics, a significant fraction of the organic acid is strong (pKa < 3). Dissolved organic carbon (DOC) contributes 4.5-5 μeq/mg DOC of strong acid to solution. The associated anions make a negative contribution to Gran acid-neutralizing capacity (ANC). Because organic anions can produce negative Gran ANC values, the common practice of considering negative values of Gran ANC evidence of acidification solely by mineral acids is not valid. The strength of organic acids also influences the observed deviation between Gran ANC values and ANC values calculated as the difference between base cation and mineral acid anion concentrations (CB - CA). Ninety percent of the deviation is due to the presence of strong organics while the remaining 10% is due to DOC-induced curvature in the F1 Gran function. Organic acids can also strongly influence pH. Their largest effects were found in the 0-50 μeq/L Gran ANC range where they depressed pH by up to 1.5 units. In addition, a method for predicting changes in pH in response to changes in mineral acidity, DOC, or both without having to rely on inferred thermodynamic constants and the uncertainties associated with them has been developed. Using the predictive method, the response of representative lakes from four sensitive lake classes to a 15-μeq/L decrease in mineral acidity ranged from +0.17 to +0.38 pH units. If concurrent increases in DOC are considered, the pH changes would be even smaller.

  10. The First Mammalian Aldehyde Oxidase Crystal Structure

    PubMed Central

    Coelho, Catarina; Mahro, Martin; Trincão, José; Carvalho, Alexandra T. P.; Ramos, Maria João; Terao, Mineko; Garattini, Enrico; Leimkühler, Silke; Romão, Maria João

    2012-01-01

    Aldehyde oxidases (AOXs) are homodimeric proteins belonging to the xanthine oxidase family of molybdenum-containing enzymes. Each 150-kDa monomer contains a FAD redox cofactor, two spectroscopically distinct [2Fe-2S] clusters, and a molybdenum cofactor located within the protein active site. AOXs are characterized by broad range substrate specificity, oxidizing different aldehydes and aromatic N-heterocycles. Despite increasing recognition of its role in the metabolism of drugs and xenobiotics, the physiological function of the protein is still largely unknown. We have crystallized and solved the crystal structure of mouse liver aldehyde oxidase 3 to 2.9 Å. This is the first mammalian AOX whose structure has been solved. The structure provides important insights into the protein active center and further evidence on the catalytic differences characterizing AOX and xanthine oxidoreductase. The mouse liver aldehyde oxidase 3 three-dimensional structure combined with kinetic, mutagenesis data, molecular docking, and molecular dynamics studies make a decisive contribution to understand the molecular basis of its rather broad substrate specificity. PMID:23019336

  11. Organ- and species-specific biological activity of rosmarinic acid.

    PubMed

    Iswandana, R; Pham, B T; van Haaften, W T; Luangmonkong, T; Oosterhuis, D; Mutsaers, H A M; Olinga, P

    2016-04-01

    Rosmarinic acid (RA), a compound found in several plant species, has beneficial properties, including anti-inflammatory and antibacterial effects. We investigated the toxicity, anti-inflammatory, and antifibrotic effects of RA using precision-cut liver slices (PCLS) and precision-cut intestinal slices (PCIS) prepared from human, mouse, and rat tissue. PCLS and PCIS were cultured up to 48h in the absence or presence of RA. Gene expression of the inflammatory markers: IL-6, IL-8/CXCL1/KC, and IL-1β, as well as the fibrosis markers: pro-collagen 1a1, heat shock protein 47, α-smooth muscle actin, fibronectin (Fn2) and plasminogen activator inhibitor-1 (PAI-1) were evaluated by qPCR. RA was only toxic in murine PCIS. RA failed to mitigate the inflammatory response in most models, while it clearly reduced IL-6 and CXCL1/KC gene expression in murine PCIS at non-toxic concentrations. With regard to fibrosis, RA decreased the gene levels of Fn2 and PAI-1 in murine PCLS, and Fn2 in murine PCIS. Yet, no effect was observed on the gene expression of fibrosis markers in human and rat PCIS. In conclusion, we observed clear organ- and species-specific effects of RA. RA had little influence on inflammation. However, our study further establishes RA as a potential candidate for the treatment of liver fibrosis. PMID:26804033

  12. Multicomponent reactions of methyl substituted all-cis tetrafluorocyclohexane aldehydes.

    PubMed

    Bykova, Tetiana; Al-Maharik, Nawaf; Slawin, Alexandra M Z; O'Hagan, David

    2016-01-21

    This paper reports the preparation of methyl substituted all-cis tetrafluorocyclohexanes prepared from a Birch reduction of benzoic acid, worked up with a methyl iodide quench. The resultant methylcyclohexadiene carboxylic acid was reduced to the alcohol, protected as an ether and then a sequence of functional group manipulations carried out to introduce four fluorines. The cyclohexadienyl ring was then epoxidised and the C-O bonds sequentially converted through deoxyfluorination reactions to two sets of isomers of all-cis tetrafluorocyclohexane isomers. The blocking methyl group renders the ring safe to hydrogen fluoride elimination. Deprotection of the benzylic ether and then oxidation gave aldehydes which were then used in Ugi and Passerini multicomponent reactions, allowing this facially polarised cyclohexane to be incorporated into peptidic structural motifs. PMID:26646211

  13. Stable carbon isotopic compositions of low-molecular-weight dicarboxylic acids, oxocarboxylic acids, α-dicarbonyls, and fatty acids: Implications for atmospheric processing of organic aerosols

    NASA Astrophysics Data System (ADS)

    Zhang, Yan-Lin; Kawamura, Kimitaka; Cao, Fang; Lee, Meehye

    2016-04-01

    Stable carbon isotopic compositions (δ13C) were measured for 23 individual organic species including 9 dicarboxylic acids, 7 oxocarboxylic acids, 1 tricarboxylic acid, 2 α-dicarbonyls, and 4 fatty acids in the aerosols from Gosan background site in East Asia. δ13C values of particle phase glyoxal and methylglyoxal are significantly larger than those previously reported for isoprene and other precursors. The values are consistently less negative in oxalic acid (C2, average -14.1‰), glyoxylic acid (-13.8‰), pyruvic acid (-19.4‰), glyoxal (-13.5‰), and methylglyoxal (-18.6‰) compared to other organic species (e.g., palmitic acid, -26.3‰), which can be explained by the kinetic isotope effects during atmospheric oxidation of pre-aged precursors (e.g., isoprene) and the subsequent gas-particle partitioning after the evaporation of clouds or wet aerosols. The δ13C values of C2 is positively correlated with C2 to organic carbon ratio, indicating that photochemical production of C2 is more pronounced than its degradation during long-range atmospheric transport. The isotopic results also suggest that aqueous phase oxidation of glyoxal and methylglyoxal is a major formation process of oxalic acid via the intermediates such as glyoxylic acid and pyruvic acid. This study provides evidence that organic aerosols are intensively photochemically aged in the western North Pacific rim.

  14. Toxicity of Select Organic Acids to the Slightly Thermophilic Acidophile Acidithiobaccillus Caldus

    SciTech Connect

    John E Aston; William A Apel; Brady D Lee; Brent M Peyton

    2009-02-01

    Acidithiobacillus caldus is a thermophilic acidophile found in commercial biomining, acid mine drainage systems, and natural environments. Previous work has characterized A. caldus as a chemolithotrophic autotroph capable of utilizing reduced sulfur compounds under aerobic conditions. Organic acids are especially toxic to chemolithotrophs in low-pH environments, where they diffuse more readily into the cell and deprotonate within the cytoplasm. In the present study, the toxic effects of oxaloacetate, pyruvate, 2-ketoglutarate, acetate, malate, succinate, and fumarate on A. caldus strain BC13 were examined under batch conditions. All tested organic acids exhibited some inhibitory effect. Oxaloacetate was observed to inhibit growth completely at a concentration of 250 µM, whereas other organic acids were completely inhibitory at concentrations of between 1,000 and 5,000 µM. In these experiments, the measured concentrations of organic acids decreased with time, indicating uptake or assimilation by the cells. Phospholipid fatty acid analyses indicated an effect of organic acids on the cellular envelope. Notable differences included an increase in cyclic fatty acids in the presence of organic acids, indicating possible instability of the cellular envelope. This was supported by field emission scanning-electron micrographs showing blebbing and sluffing in cells grown in the presence of organic acids.

  15. Toxicity of select organic acids to the slightly thermophilic acidophile Acidithiobacillus caldus.

    PubMed

    Aston, John E; Apel, William A; Lee, Brady D; Peyton, Brent M

    2009-02-01

    Acidithiobacillus caldus is a thermophilic acidophile found in commercial biomining, acid mine drainage systems, and natural environments. Previous work has characterized A. caldus as a chemolithotrophic autotroph capable of utilizing reduced sulfur compounds under aerobic conditions. Organic acids are especially toxic to chemolithotrophs in low-pH environments, where they diffuse more readily into the cell and deprotonate within the cytoplasm. In the present study, the toxic effects of oxaloacetate, pyruvate, 2-ketoglutarate, acetate, malate, succinate, and fumarate on A. caldus strain BC13 were examined under batch conditions. All tested organic acids exhibited some inhibitory effect. Oxaloacetate was observed to inhibit growth completely at a concentration of 250 microM, whereas other organic acids were completely inhibitory at concentrations of between 1,000 and 5,000 microM. In these experiments, the measured concentrations of organic acids decreased with time, indicating uptake or assimilation by the cells. Phospholipid fatty acid analyses indicated an effect of organic acids on the cellular envelope. Notable differences included an increase in cyclic fatty acids in the presence of organic acids, indicating possible instability of the cellular envelope. This was supported by field emission scanning-electron micrographs showing blebbing and sluffing in cells grown in the presence of organic acids. PMID:18803441

  16. Influence of Organic Acids on Diltiazem HCl Release Kinetics from Hydroxypropyl Methyl Cellulose Matrix Tablets.

    PubMed

    Sateesha, Sb; Rajamma, Aj; Narode, Mk; Vyas, Bd

    2010-07-01

    The matrix tablets of diltiazem hydrochloride were prepared by direct compression using hydroxypropyl methyl cellulose (HPMC) and various amounts (2.5%, 5.0%, 10% and 20%) of citric acid, malic acid and succinic acid. The characterization of physical mixture of drug and organic acids was performed by Infra-red spectroscopy. An organic acid was incorporated to set up a system bringing about gradual release of this drug. The influence of organic acids on the release rate were described by the Peppas equation: M (t) /M(∞) = Kt (n) and Higuchi's equation: Q (t) = K(1)t(1/2). The addition of organic acids and the pH value of medium could notably influence the dissolution behavior and mechanism of drug-release from matrices. Increasing amounts of organic acid produced an increase in drug release rate, which showed a good linear relationship between contents of organic acid and drug accumulate release (%) in phosphate buffer, pH 7.4. The drug release increased significantly (P < 0.05) with use of succinic acid in tablet formulation. Increasing amounts of succinic acid above 10% produced decreasing values of n and increasing values of k, in a linear relationship, which indicated there was a burst release of drug from the matrix. Optimized formulations are found to be stable upon 3-month study. PMID:21042476

  17. Influence of Organic Acids on Diltiazem HCl Release Kinetics from Hydroxypropyl Methyl Cellulose Matrix Tablets

    PubMed Central

    Sateesha, SB; Rajamma, AJ; Narode, MK; Vyas, BD

    2010-01-01

    The matrix tablets of diltiazem hydrochloride were prepared by direct compression using hydroxypropyl methyl cellulose (HPMC) and various amounts (2.5%, 5.0%, 10% and 20%) of citric acid, malic acid and succinic acid. The characterization of physical mixture of drug and organic acids was performed by Infra-red spectroscopy. An organic acid was incorporated to set up a system bringing about gradual release of this drug. The influence of organic acids on the release rate were described by the Peppas equation: M t /M∞ = Kt n and Higuchi’s equation: Q t = K1t1/2. The addition of organic acids and the pH value of medium could notably influence the dissolution behavior and mechanism of drug-release from matrices. Increasing amounts of organic acid produced an increase in drug release rate, which showed a good linear relationship between contents of organic acid and drug accumulate release (%) in phosphate buffer, pH 7.4. The drug release increased significantly (P < 0.05) with use of succinic acid in tablet formulation. Increasing amounts of succinic acid above 10% produced decreasing values of n and increasing values of k, in a linear relationship, which indicated there was a burst release of drug from the matrix. Optimized formulations are found to be stable upon 3-month study. PMID:21042476

  18. 40 CFR 721.639 - Amine aldehyde condensate.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Amine aldehyde condensate. 721.639... Substances § 721.639 Amine aldehyde condensate. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as an amine aldehyde condensate (PMN...

  19. 40 CFR 721.639 - Amine aldehyde condensate.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Amine aldehyde condensate. 721.639... Substances § 721.639 Amine aldehyde condensate. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as an amine aldehyde condensate (PMN...

  20. 40 CFR 721.639 - Amine aldehyde condensate.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Amine aldehyde condensate. 721.639... Substances § 721.639 Amine aldehyde condensate. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as an amine aldehyde condensate (PMN...

  1. 40 CFR 721.639 - Amine aldehyde condensate.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Amine aldehyde condensate. 721.639... Substances § 721.639 Amine aldehyde condensate. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as an amine aldehyde condensate (PMN...

  2. 40 CFR 721.639 - Amine aldehyde condensate.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Amine aldehyde condensate. 721.639... Substances § 721.639 Amine aldehyde condensate. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as an amine aldehyde condensate (PMN...

  3. 40 CFR 721.5762 - Aromatic aldehyde phenolic resin (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Aromatic aldehyde phenolic resin... Specific Chemical Substances § 721.5762 Aromatic aldehyde phenolic resin (generic). (a) Chemical substance... aromatic aldehyde phenolic resin (PMN P-01-573) is subject to reporting under this section for...

  4. CARBON CONTRIBUTION AND CHARACTERISTICS OF HUMIC ACID, FULVIC ACID, PARTICULATE ORGANIC MATTER AND GLOMALIN IN DIVERSE ECOSYSTEMS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Global climate change and soil carbon sequestration issues are entering the forefront of public policy, and emphasis is growing for research on carbon sinks and long-term terrestrial carbon stabilization. Humic acid (HA), fulvic acid (FA), humin and particulate organic matter (POM) have traditionall...

  5. Aldehyde Reduction by Cytochrome P450

    PubMed Central

    Amunom, Immaculate; Srivastava, Sanjay; Prough, Russell A.

    2011-01-01

    This protocol describes the procedure for measuring the relative rates of metabolism of the α,β-unsaturated aldehydes, 9-anthracene aldehyde (9-AA) and 4-hydroxy-trans-2-nonenal (4-HNE); specifically the aldehyde reduction reactions of cytochrome P450s (CYPs). These assays can be performed using either liver microsomal or other tissue fractions, spherosome preparations of recombinant CYPs, or recombinant CYPs from other sources. The method used here to study the reduction of a model α,β-unsaturated aldehyde, 9-AA, by CYPs was adapted from the assay used to investigate 9-anthracene oxidation as reported by Marini et al. (Marini et al., 2003). For experiments measuring reduction of the endogenous aldehyde, 4-HNE, the substrate was incubated with CYP in the presence of oxygen and NADPH and the metabolites were separated by High Pressure Liquid Chromatograpy (HPLC), using an adaptation of the method of Srivastava et al. (Srivastava et al., 2010). For study of 9-AA and 4-HNE reduction, the first step involves incubation of the substrate with the CYP in appropriate media, followed by quantification of metabolites through either spectrofluorimetry or analysis by HPLC coupled with a radiometric assay, respectively. Metabolite identification can be achieved by HPLC GC-mass spectrometric analysis. Inhibitors of cytochrome P450 function can be utilized to show the role of the hemoprotein or other enzymes in these reduction reactions. The reduction reactions for CYP’s were not inhibited by either anaerobiosis or inclusion of CO in the gaseous phase of the reaction mixture. These character of these reactions are similar to those reported for some cytochrome P450-catalyzed azo reduction reactions. PMID:21553396

  6. Novel Haloperoxidase from the Agaric Basidiomycete Agrocybe aegerita Oxidizes Aryl Alcohols and Aldehydes

    PubMed Central

    Ullrich, René; Nüske, Jörg; Scheibner, Katrin; Spantzel, Jörg; Hofrichter, Martin

    2004-01-01

    Agrocybe aegerita, a bark mulch- and wood-colonizing basidiomycete, was found to produce a peroxidase (AaP) that oxidizes aryl alcohols, such as veratryl and benzyl alcohols, into the corresponding aldehydes and then into benzoic acids. The enzyme also catalyzed the oxidation of typical peroxidase substrates, such as 2,6-dimethoxyphenol (DMP) or 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonate) (ABTS). A. aegerita peroxidase production depended on the concentration of organic nitrogen in the medium, and highest enzyme levels were detected in the presence of soybean meal. Two fractions of the enzyme, AaP I and AaP II, which had identical molecular masses (46 kDa) and isoelectric points of 4.6 to 5.4 and 4.9 to 5.6, respectively (corresponding to six different isoforms), were identified after several steps of purification, including anion- and cation-exchange chromatography. The optimum pH for the oxidation of aryl alcohols was found to be around 7, and the enzyme required relatively high concentrations of H2O2 (2 mM) for optimum activity. The apparent Km values for ABTS, DMP, benzyl alcohol, veratryl alcohol, and H2O2 were 37, 298, 1,001, 2,367 and 1,313 μM, respectively. The N-terminal amino acid sequences of the main AaP II spots blotted after two-dimensional gel electrophoresis were almost identical and exhibited almost no homology to the sequences of other peroxidases from basidiomycetes, but they shared the first three amino acids, as well as two additional amino acids, with the heme chloroperoxidase (CPO) from the ascomycete Caldariomyces fumago. This finding is consistent with the fact that AaP halogenates monochlorodimedone, the specific substrate of CPO. The existence of haloperoxidases in basidiomycetous fungi may be of general significance for the natural formation of chlorinated organic compounds in forest soils. PMID:15294788

  7. [Determination of organic acids in rice wine by ion-exclusion chromatography].

    PubMed

    Lin, Xiaojie; Wei, Wei; He, Zhigang; Lin, Xiaozi

    2014-03-01

    An ion-exclusion chromatographic method for the simultaneous determination of organic acids in rice wine was developed. An IC-Pak Ion Exclusion column (300 mm x 7.8 mm, 7 microm) was used at 50 degrees C. The mobile phases were H2SO4 (phase A) and acetonitrile (phase B) (98:2, v/v) at a flow rate of 0.5 mL/min. The gradient elution program was as follows: 0-40 min, 0.01 mol/L H2SO4 to 0.02 mol/L H2SO4; 40-50 min, 0.01 mol/L H2SO4. The injection volume was 10 microL. The detection wavelength was set at 210 nm. The results showed that oxalic acid, maleic acid, citric acid, tartaric acid, malic acid, ascorbic acid, succinic acid, lactic, fumaric acid, acetic acid, propionic acid, isobutyric acid and butyric acid were completely separated and determined in 30 min. The linear correlation coefficients were above 0.999 7 in the range of 0.001- 1.000 g/L. Under the optimized conditions, the recoveries of organic acids in rice wine were in the range of 93.4% - 103.8% with the relative standard deviations (RSDs, n = 5) of 0.1% - 1.5%. This method is feasible, convenient, fast, accurate and applicable for the quantitative analysis of the organic acids in rice wine. PMID:24984473

  8. Kinetics of Forming Aldehydes in Frying Oils and Their Distribution in French Fries Revealed by LC-MS-Based Chemometrics.

    PubMed

    Wang, Lei; Csallany, A Saari; Kerr, Brian J; Shurson, Gerald C; Chen, Chi

    2016-05-18

    In this study, the kinetics of aldehyde formation in heated frying oils was characterized by 2-hydrazinoquinoline derivatization, liquid chromatography-mass spectrometry (LC-MS) analysis, principal component analysis (PCA), and hierarchical cluster analysis (HCA). The aldehydes contributing to time-dependent separation of heated soybean oil (HSO) in a PCA model were grouped by the HCA into three clusters (A1, A2, and B) on the basis of their kinetics and fatty acid precursors. The increases of 4-hydroxynonenal (4-HNE) and the A2-to-B ratio in HSO were well-correlated with the duration of thermal stress. Chemometric and quantitative analysis of three frying oils (soybean, corn, and canola oils) and French fry extracts further supported the associations between aldehyde profiles and fatty acid precursors and also revealed that the concentrations of pentanal, hexanal, acrolein, and the A2-to-B ratio in French fry extracts were more comparable to their values in the frying oils than other unsaturated aldehydes. All of these results suggest the roles of specific aldehydes or aldehyde clusters as novel markers of the lipid oxidation status for frying oils or fried foods. PMID:27128101

  9. Organic Acid Excretion in Penicillium ochrochloron Increases with Ambient pH

    PubMed Central

    Vrabl, Pamela; Fuchs, Viktoria; Pichler, Barbara; Schinagl, Christoph W.; Burgstaller, Wolfgang

    2012-01-01

    Despite being of high biotechnological relevance, many aspects of organic acid excretion in filamentous fungi like the influence of ambient pH are still insufficiently understood. While the excretion of an individual organic acid may peak at a certain pH value, the few available studies investigating a broader range of organic acids indicate that total organic acid excretion rises with increasing external pH. We hypothesized that this phenomenon might be a general response of filamentous fungi to increased ambient pH. If this is the case, the observation should be widely independent of the organism, growth conditions, or experimental design and might therefore be a crucial key point in understanding the function and mechanisms of organic acid excretion in filamentous fungi. In this study we explored this hypothesis using ammonium-limited chemostat cultivations (pH 2–7), and ammonium or phosphate-limited bioreactor batch cultivations (pH 5 and 7). Two strains of Penicillium ochrochloron were investigated differing in the spectrum of excreted organic acids. Confirming our hypothesis, the main result demonstrated that organic acid excretion in P. ochrochloron was enhanced at high external pH levels compared to low pH levels independent of the tested strain, nutrient limitation, and cultivation method. We discuss these findings against the background of three hypotheses explaining organic acid excretion in filamentous fungi, i.e., overflow metabolism, charge balance, and aggressive acidification hypothesis. PMID:22493592

  10. Structural organization of fatty acid desaturase loci in linseed lines with contrasting linolenic acid contents.

    PubMed

    Thambugala, Dinushika; Ragupathy, Raja; Cloutier, Sylvie

    2016-07-01

    Flax (Linum usitatissimum L.), the richest crop source of omega-3 fatty acids (FAs), is a diploid plant with an estimated genome size of ~370 Mb and is well suited for studying genomic organization of agronomically important traits. In this study, 12 bacterial artificial chromosome clones harbouring the six FA desaturase loci sad1, sad2, fad2a, fad2b, fad3a and fad3b from the conventional variety CDC Bethune and the high linolenic acid line M5791 were sequenced, analysed and compared to determine the structural organization of these loci and to gain insights into the genetic mechanisms underlying FA composition in flax. With one gene every 3.2-4.6 kb, the desaturase loci have a higher gene density than the genome's average of one gene per 7.8-8.2 kb. The gene order and orientation across the two genotypes were generally conserved with the exception of the sad1 locus that was predicted to have additional genes in CDC Bethune. High sequence conservation in both genic and intergenic regions of the sad and fad2b loci contrasted with the significant level of variation of the fad2a and fad3 loci, with SNPs being the most frequently observed mutation type. The fad2a locus had 297 SNPs and 36 indels over ~95 kb contrasting with the fad2b locus that had a mere seven SNPs and four indels in ~110 kb. Annotation of the gene-rich loci revealed other genes of known role in lipid or carbohydrate metabolic/catabolic pathways. The organization of the fad2b locus was particularly complex with seven copies of the fad2b gene in both genotypes. The presence of Gypsy, Copia, MITE, Mutator, hAT and other novel repeat elements at the desaturase loci was similar to that of the whole genome. This structural genomic analysis provided some insights into the genomic organization and composition of the main desaturase loci of linseed and of their complex evolution through both tandem and whole genome duplications. PMID:27142663

  11. Catalytic production of methyl acrylates by gold-mediated cross coupling of unsaturated aldehydes with methanol

    NASA Astrophysics Data System (ADS)

    Karakalos, Stavros; Zugic, Branko; Stowers, Kara J.; Biener, Monika M.; Biener, Juergen; Friend, Cynthia M.; Madix, Robert J.

    2016-10-01

    Modern methods of esterification, one of the most important reactions in organic synthesis, are reaching their limits, as far as waste and expense are concerned. Novel chemical approaches to ester formation are therefore of importance. Here we report a simple procedure free of caustic reagents or byproducts for the facile direct oxidative methyl esterification of aldehydes over nanoporous Au catalysts. Complementary model studies on single crystal gold surfaces establish the fundamental reactions involved. We find that methanol more readily reacts with adsorbed active oxygen than do the aldehydes, but that once the aldehydes do react, they form strongly-bound acrylates that block reactive sites and decrease the yields of acrylic esters under steady flow conditions at 420 K. Significant improvements in yield can be achieved by operating at higher temperatures, which render the site-blocking acrylates unstable.

  12. Chemoselective Reduction of Tertiary Amides under Thermal Control: Formation of either Aldehydes or Amines.

    PubMed

    Tinnis, Fredrik; Volkov, Alexey; Slagbrand, Tove; Adolfsson, Hans

    2016-03-24

    The chemoselective reduction of amides in the presence of other more reactive reducible functional groups is a highly challenging transformation, and successful examples thereof are most valuable in synthetic organic chemistry. Only a limited number of systems have demonstrated the chemoselective reduction of amides over ketones. Until now, the aldehyde functionality has not been shown to be compatible in any catalytic reduction protocol. Described herein is a [Mo(CO)6 ]-catalyzed protocol with an unprecedented chemoselectivity and allows for the reduction of amides in the presence of aldehydes and imines. Furthermore, the system proved to be tunable by variation of the temperature, which enabled for either C-O or C-N bond cleavage that ultimately led to the isolation of both amines and aldehydes, respectively, in high chemical yields. PMID:26934055

  13. Stable carbon isotopic compositions of low-molecular-weight dicarboxylic acids, oxocarboxylic acids, α-dicarbonyls, and fatty acids: implications for atmospheric processing of organic aerosols

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Kawamura, K.; Cao, F.; Lee, M.

    2015-12-01

    Stable carbon isotopic compositions (δ13C) were measured for 23 individual organic species including 9 dicarboxylic acids, 7 oxocarboxylic acids, 1 tricarboxylic acid, 2 α-dicarbonyls and 4 fatty acids in the aerosols from Gosan background site in East Asia. δ13C of particle-phase glyoxal and methylglyoxal are significantly higher than those previously reported for isoprene and other precursors, associated with isotope fractionation during atmospheric oxidation. 13C is consistently more enriched for oxalic acid (C2), glyoxylic acid, pyruvic acid, glyoxal and methylglyoxal compared to other organic compounds identified, which can be explained by the kinetic isotope effects during aqueous-phase processing and the subsequent gas-particle partitioning after clouds or wet aerosols evaporation δ13C of C2 is positively correlated with C2 and organic carbon ratio, indicating that a photochemical production of C2 is more pronounced than its degradation process during long-range transport. The 13C results also suggest that aqueous-phase oxidation of glyoxal and methylglyoxal is major formation process of oxalic acid production via the major intermediates glyoxylic acid and pyruvic acid. This study provides evidence that organic aerosols are intensively photo-chemically aged in this region.

  14. Formic and Acetic Acid Observations over Colorado by Chemical Ionization Mass Spectrometry and Organic Acids' Role in Air Quality

    NASA Astrophysics Data System (ADS)

    Treadaway, V.; O'Sullivan, D. W.; Heikes, B.; Silwal, I.; McNeill, A.

    2015-12-01

    Formic acid (HFo) and acetic acid (HAc) have both natural and anthropogenic sources and a role in the atmospheric processing of carbon. These organic acids also have an increasing importance in setting the acidity of rain and snow as precipitation nitrate and sulfate concentrations have decreased. Primary emissions for both organic acids include biomass burning, agriculture, and motor vehicle emissions. Secondary production is also a substantial source for both acids especially from biogenic precursors, secondary organic aerosols (SOAs), and photochemical production from volatile organic compounds (VOCs) and oxygenated volatile organic compounds (OVOCs). Chemical transport models underestimate organic acid concentrations and recent research has sought to develop additional production mechanisms. Here we report HFo and HAc measurements during two campaigns over Colorado using the peroxide chemical ionization mass spectrometer (PCIMS). Iodide clusters of both HFo and HAc were recorded at mass-to-charge ratios of 173 and 187, respectively. The PCIMS was flown aboard the NCAR Gulfstream-V platform during the Deep Convective Clouds and Chemistry Experiment (DC3) and aboard the NCAR C-130 during the Front Range Air Pollution and Photochemistry Experiment (FRAPPE). The DC3 observations were made in May and June 2012 extending from the surface to 13 km over the central and eastern United States. FRAPPE observations were made in July and August 2014 from the surface to 7 km over Colorado. DC3 measurements reported here are focused over the Colorado Front Range and complement the FRAPPE observations. DC3 HFo altitude profiles are characterized by a decrease up to 6 km followed by an increase either back to boundary layer mixing ratio values or higher (a "C" shape). Organic acid measurements from both campaigns are interpreted with an emphasis on emission sources (both natural and anthropogenic) over Colorado and in situ photochemical production especially ozone precursors.

  15. Collection and analysis of organic acids in exhaust gas. Comparison of different methods

    NASA Astrophysics Data System (ADS)

    Zervas, E.; Montagne, X.; Lahaye, J.

    This paper reports the development of a specific method to identify organic acids in exhaust gases. The organic acids are collected in two impingers containing liquids (pure water or Na 2CO 3 1% aqueous solution) and four cartridges containing solids (silica, fluorisil, alumina B and alumina N). Once collected, the acids are eluted of the solids by a hot water stream. These traps performances, in terms of organic acids collection and elution efficiency, are evaluated and compared. Two sources are used to produce the gas flow containing organic acids: one generates a flow whose concentration is known and stable, the other produces organic acids among other combustion products. For eluted solutions analysis, two methods are used: isocratic ionic chromatography/conductivity detection and GC/FID. Their efficiency in separating 10 aliphatic acids are compared. Their characteristics such as detection limits, detection linearity, repeatability and possible interferences with other components found in exhaust gases are determined. The stability of the organic acids solutions is also studied. Lastly, the use of these methods is illustrated by the analysis of the gas-phase organic acids exhausted by a spark ignition and by a diesel engine.

  16. Dissolution behavior of Caldag lateritic nickel ore subjected to a sequential organic acid leaching method

    NASA Astrophysics Data System (ADS)

    Kursunoglu, Sait; Kaya, Muammer

    2015-11-01

    The dissolution behavior of Caldag lateritic nickel ore subjected to a sequential organic acid leaching method was investigated. The effects of the type of organic acid, acid concentration, leaching time, and leaching temperature on the lateritic nickel ore were examined. Organic acids were used individually prior to sequential leaching. Citric acid was more effective than the other two acids for the selective leaching of nickel and cobalt. An increase in the citric acid concentration negligibly affected the dissolution of the metals, whereas temperature exhibited a strong beneficial effect. Oxalic acid was determined to be the most appropriate organic acid for the second leaching step. After 8 h (4 h + 4 h) of leaching with organic acids (0.5 M citric + 0.5 M oxalic) in sequence at 90°C, 89.63% Ni, 82.89% Co, and 69.63% Fe were leached from the lateritic nickel ore. A sequential citric + oxalic acid leaching method could represent a viable alternative for the dissolution of metals from lateritic nickel ore.

  17. OXIDATIVE DEGRADATION OF ORGANIC ACIDS CONJUGATED WITH SULFITE OXIDATION IN FLUE GAS DESULFURIZATION

    EPA Science Inventory

    The report gives results of a study of organic acid degradation conjugated with sulfite oxidation under flue gas desulfurization (FGD) conditions. The oxidative degradation constant, k12, is defined as the ratio of organic acid degradation rate and sulfite oxidation rate times th...

  18. Production of organic acid esters from biomass - novel processes and concepts

    SciTech Connect

    Datta, R.

    1981-01-01

    After low cost, low energy pretreatment, lignocellulose can be converted directly to volatile (C/sub 2/-C/sub 6/) organic acids by mixed-culture acidogenic fermentation. The principal components of lignocellulose (pectins, hemicellulose, cellulose, and lignin) are all converted to organic acids in high yields. Esterification from dilute aqueous solutions using novel techniques based on adsorption, solvent extraction, or biochemical conversion could be an important method for recovering these acids and simultaneously producing liquid fuels or chemical feedstocks. Uses of organic acid esters and conceptual biomass conversion processes are outlined. The significance of these processes for substantially increasing liquid fuel productivity from biomass feedstocks are discussed.

  19. Formation and control of aldehydes in alcohol fueled engines

    SciTech Connect

    Ayyasamy, R.; Nagalingam, B.; Ganesan, V.; Gopalakrishnan, K.V.; Murthy, B.S.

    1981-01-01

    Aldehyde formation and emissions from alcohol fueled engines are presented in this paper. Several chemical kinetic models on the mechanism leading to aldehyde formation have been examined to explore the appropriate control methods to reduce exhaust aldehyde emissions. Control of aldehydes in exhaust emissions by suitable alteration of engine operating parameters, by in cylinder treatment with additives like aniline and water, by external treatment like airpreheating, secondary air injection cooling water rate and exhaust treatment are examined. The concept of surface ignition for alcohol fuels is briefly presented as a long range objective for using alcohols with minimal aldehyde emissions. 27 refs.

  20. Organic acids enhanced decoloration of azo dye in gas phase surface discharge plasma system.

    PubMed

    Wang, Tiecheng; Qu, Guangzhou; Ren, Jingyu; Sun, Qiuhong; Liang, Dongli; Hu, Shibin

    2016-01-25

    A gas phase surface discharge plasma combined with organic acids system was developed to enhance active species mass transfer and dye-containing wastewater treatment efficacy, with Acid Orange II (AO7) as the model pollutant. The effects of discharge voltage and various organic acid additives (acetic acid, lactic acid and nonoic acid) on AO7 decoloration efficiency were evaluated. The experimental results showed that an AO7 decoloration efficiency of approximately 69.0% was obtained within 4 min of discharge plasma treatment without organic acid addition, which was improved to 82.8%, 83.5% and 88.6% within the same treatment time with the addition of acetic acid, lactic acid and nonoic acid, respectively. The enhancement effects on AO7 decoloration efficiency could be attributed to the decrease in aqueous surface tension, improvement in bubble distribution and shape, and increase in ozone equivalent concentration. The AO7 wastewater was biodegradable after discharge plasma treatment with the addition of organic acid. AO7 decomposition intermediates were analyzed by UV-vis spectrometry and GC-MS; 2-naphthol, 1,4-benzoquinone, phthalic anhydride, coumarin, 1,2-naphthoquinone, and 2-formyl-benzoic acid were detected. A possible pathway for AO7 decomposition in this system was proposed. PMID:26444488

  1. Thermophysical properties of starch and whey protein composite prepared in presence of organic acid and esters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previously, we prepared starch and protein composite by reactive mixing in presence of various organic acids and found that use of these acid esters resulted in composites with good mechanical properties. In this study, concentration (% w/w) of acid citrates in the starch-protein composites were var...

  2. Effects of simulated acid precipitation on decomposition and leaching of organic carbon in forest soils

    SciTech Connect

    Chang, F.H.; Alexander, M.

    1984-09-01

    Soil samples from three watersheds of New York State were treated with simulated rain at pH 3.5, 4.1, and 5.6 daily for 14 d, at 12 3-d intervals in three separate tests, or at 22 7-d intervals. Except for one system of treating the three forest soils, simulated acid rain reduced the amount of organic matter leached from samples of soil from which more than 0.05% of the organic carbon was leached during the exposure period. In the soil samples representing the exceptions, acid rain enhanced the leaching of organic matter. Samples from the organic layer of the treated samples of acid soil were taken at two equal depths, and the rates of organic matter decomposition in the two layers were studied. As compared with simulated rain at pH 5.6, simulated acid rain reduced the decomposition of organic matter in the three soils at both depths in three of the five tests and at both depths of two of the soils in the fourth test. In some instances, organic matter decomposition was enhanced by the simulated acid rain. Except for the sample of soil at the highest initial pH, carbon mineralization was inhibited in soils and treatments in which simulated acid rain reduced the amount of organic carbon leached, and it was stimulated in soils and treatments in which the quantity of organic carbon leached was increased by the simulated acid rain. 12 references, 3 figures, 8 tables.

  3. Structure of six organic acid-base adducts from 6-bromobenzo[d]thiazol-2-amine and acidic compounds

    NASA Astrophysics Data System (ADS)

    Jin, Shouwen; Zhang, Jing; Wang, Daqi; Tao, Lin; Zhou, Mengjian; Shen, Yinyan; Chen, Quan; Lin, Zhanghui; Gao, Xingjun

    2014-05-01

    Six anhydrous organic acid-base adducts of 6-bromobenzo[d]thiazol-2-amine were prepared with organic acids as 2,4,6-trinitrophenol, salicylic acid, 3,5-dinitrobenzoic acid, 3,5-dinitrosalicylic acid, malonic acid and sebacic acid. The compounds 1-6 were characterized by X-ray diffraction analysis, IR, and elemental analysis. The melting points of all the adducts were given. Of the six adducts, 1, 3, 4, and 5 are organic salts, while 2, and 6 are cocrystals. The supramolecular arrangement in the crystals 2-6 is based on the R22(8) synthon. Analysis of the crystal packing of 1-6 suggests that there are strong NH⋯O, OH⋯N, and OH⋯O hydrogen bonds (charge assisted or neutral) between acid and base components in the supramolecular assemblies. When the hydroxyl group is present in the ortho position of the carboxy, the intramolecular S6 synthon is present, as expected. Besides the classical hydrogen bonding interactions, other noncovalent interactions also play important roles in structure extension. Due to the synergetic effect of these weak interactions, compounds 1-6 display 1D-3D framework structure.

  4. Evidence of rapid production of organic acids in an urban air mass

    NASA Astrophysics Data System (ADS)

    Veres, Patrick R.; Roberts, James M.; Cochran, Anthony K.; Gilman, Jessica B.; Kuster, William C.; Holloway, John S.; Graus, Martin; Flynn, James; Lefer, Barry; Warneke, Carsten; de Gouw, Joost

    2011-09-01

    Gas-phase acids (nitric, formic, acrylic, methacrylic, propionic, and pyruvic/butryic acid) were measured using negative-ion proton-transfer chemical-ionization mass spectrometry (NI-PT-CIMS) in Pasadena, CA as part of the CalNex 2010 (Research at the Nexus of Air Quality and Climate Change) study in May-June 2010. Organic acid concentrations ranged from a few parts per trillion by volume (pptv) to several parts per billion by volume (ppbv), with the largest concentrations observed for formic and propionic acids. Photochemically processed urban emissions transported from Los Angeles were frequently sampled during the day. Analysis of transported emissions demonstrates a strong correlation of organic acid concentrations with both nitric acid and odd oxygen (Ox = O3 + NO2) showing that the organic acids are photochemically and rapidly produced from urban emissions.

  5. Field and Laboratory Studies of Reactions between Atmospheric Water Soluble Organic Acids and Inorganic Particles

    SciTech Connect

    Wang, Bingbing; Kelly, Stephen T.; Sellon, Rachel E.; Shilling, John E.; Tivanski, Alexei V.; Moffet, Ryan C.; Gilles, Mary K.; Laskin, Alexander

    2013-06-25

    Atmospheric inorganic particles undergo complex heterogeneous reactions that change their physicochemical properties. Depletion of chloride in sea salt particles was reported in previous field studies and was attributed to the acid displacement of chlorides with inorganic acids, such as nitric and sulfuric acids [1-2]. Recently, we showed that NaCl can react with water soluble organic acids (WSOA) and release gaseous hydrochloric acid (HCl) resulting in formation of organic salts [3]. A similar mechanism is also applicable to mixed WSOA/nitrate particles where multi-phase reactions are driven by the volatility of nitric acid. Furthermore, secondary organic material, which is a complex mixture of carboxylic acids, exhibits the same reactivity towards chlorides and nitrates. Here, we present a systematic study of reactions between atmospheric relevant WSOA, SOM, and inorganic salts including NaCl, NaNO3, and Ca(NO3)2 using complementary micro-spectroscopy analysis.

  6. Aqueous leaching of organic acids and dissolved organic carbon from various biochars prepared at different temperatures.

    PubMed

    Liu, Peng; Ptacek, Carol J; Blowes, David W; Berti, William R; Landis, Richard C

    2015-03-01

    Biochar has been used as a soil amendment, as a water treatment material, and for carbon (C) sequestration. Thirty-six biochars, produced from wood, agricultural residue, and manure feedstocks at different temperatures, were evaluated for the aqueous leaching of different forms of soluble C. The release of inorganic C (alkalinity), organic acids (OAs), and total dissolved organic C (DOC) was highly variable and dependent on the feedstock and pyrolysis temperature. The pH and alkalinity increased for the majority of samples. Higher pH values were associated with high-temperature (high-T) (600 and 700°C) biochars. Statistically significant differences in alkalinity were not observed between low-temperature (low-T) (300°C) and high-T biochars, whereas alkalinity released from wood-based biochar was significantly lower than from others. Concentrations of OAs and DOC released from low-T biochars were greater than from high-T biochars. The C in the OAs represented 1 to 60% of the total DOC released, indicating the presence of other DOC forms. The C released as DOC represented up to 3% (majority <0.1%) of the total C in the biochar. Scanning electron microscopy with energy dispersive X-ray spectroscopy showed the high-T biochars had a greater proportion of micropores. Fourier transform infrared spectroscopy showed that hydroxyl, aliphatic, and quinone were the predominant functional groups of all biochars and that the abundance of other functional groups was dependent on the feedstock. The release of DOC, especially bioavailable forms such as OAs, may promote growth of organisms and heavy metal complexation and diminish the potential effectiveness of various biochars for C sequestration. PMID:26023986

  7. Residual Particle Sizes of Evaporating Droplets: Ammonium Sulfate and Aldehydes

    NASA Astrophysics Data System (ADS)

    Sedehi, N.; Galloway, M. M.; De Haan, D. O.

    2012-12-01

    The reactions of carbonyls like glyoxal, methylglyoxal, and glycolaldehyde, with ammonium salts have been proposed as significant sources of atmospheric organic aerosol. Aerosol containing these compounds was generated in the laboratory using the Vibrating Orifice Aerosol Generator (VOAG). The particles were completely dried before they were measured using a SMPS system. The nonvolatile fraction of the resulting aerosol was measured. The drying times were varied between two and twenty minutes, and for ammonium sulfate and glyoxal reactions, minimum residual particle sizes were reached after 3.5 minutes. Reactions of glyoxal, glycolaldehyde, and methylglyoxal with ammonium sulfate appeared to have lower non-volatile fractions remaining at higher starting concentrations, suggesting that a constant 'excess volume,' likely water, was present in the residual particles that could not be evaporated even after 20 minutes of drying. These excess volumes were not observed in our previous experiments with aldehydes but no ammonium sulfate present. At the highest concentrations tested (100 uM), non-volatile fractions of aldehydes present in residual particles were 16 (±17) %, 41 (±28) %, and 17(±32) % for glyoxal, glycolaldehyde, and methylglyoxal, respectively.

  8. Concentration and fractionation of hydrophobic organic acid constituents from natural waters by liquid chromatography

    USGS Publications Warehouse

    Thurman, E.M.; Malcolm, R.L.

    1979-01-01

    A scheme is presented which used adsorption chromatography with pH gradient elution and size-exclusion chromatography to concentrate and separate hydrophobic organic acids from water. A review of chromatographic processes involved in the flow scheme is also presented. Organic analytes which appear in each aqueous fraction are quantified by dissolved organic carbon analysis. Hydrophobic organic acids in a water sample are concentrated on a porous acrylic resin. These acids usually constitute approximately 30-50 percent of the dissolved organic carbon in an unpolluted water sample and are eluted with an aqueous eluent (dilute base). The concentrate is then passed through a column of polyacryloylmorpholine gel, which separates the acids into high- and low-molecular-weight fractions. The high- and low-molecular-weight eluates are reconcentrated by adsorption chromatography, then are eluted with a pH gradient into strong acids (predominately carboxylic acids) and weak acids (predominately phenolic compounds). For standard compounds and samples of unpolluted waters, the scheme fractionates humic substances into strong and weak acid fractions that are separated from the low molecular weight acids. A new method utilizing conductivity is also presented to estimate the acidic components in the methanol fraction.

  9. Cytochromes P450 Catalyze the Reduction of α,β-Unsaturated Aldehydes

    PubMed Central

    Amunom, Immaculate; Dieter, Laura J.; Tamasi, Viola; Cai, Jan; Conklin, Daniel J.; Srivastava, Sanjay; Martin, Martha V.; Guengerich, F. Peter; Prough, Russell A.

    2011-01-01

    The metabolism of α,β-unsaturated aldehydes, e.g. 4-hydroxynonenal, involves oxidation to carboxylic acids, reduction to alcohols, and glutathionylation to eventually form mercapturide conjugates. Recently we demonstrated that P450s can oxidize aldehydes to carboxylic acids, a reaction previously thought to involve aldehyde dehydrogenase. When recombinant cytochrome P450 3A4 was incubated with 4-hydroxynonenal, O2, and NADPH, several products were produced, including 1,4-dihydroxynonene (DHN), 4-hydroxy-2-nonenoic acid (HNA), and an unknown metabolite. Several P450s catalyzed the reduction reaction in the order (human) P450 2B6 ≅ P450 3A4 > P450 1A2 > P450 2J2 > (mouse) P450 2c29. Other P450s did not catalyze the reduction reaction (human P450 2E1 & rabbit P450 2B4). Metabolism by isolated rat hepatocytes showed that HNA formation was inhibited by cyanamide, while DHN formation was not affected. Troleandomycin increased HNA production 1.6-fold while inhibiting DHN formation, suggesting that P450 3A11 is a major enzyme involved in rat hepatic clearance of 4-HNE. A fluorescent assay was developed using 9-anthracenealdehyde to measure both reactions. Feeding mice diet containing t-butylated hydroxyanisole increased the level of both activities with hepatic microsomal fractions, but not proportionally. Miconazole (0.5 mM) was a potent inhibitor of these microsomal reduction reactions, while phenytoin and α-naphthoflavone (both at 0.5 mM) were partial inhibitors, suggesting the role of multiple P450 enzymes. The oxidative metabolism of these aldehydes was inhibited >90% in an Ar or CO atmosphere, while the reductive reactions were not greatly affected. These results suggest that P450s are significant catalysts of reduction of α,β-unsaturated aldehydes in liver. PMID:21766881

  10. Desorption of copper and cadmium from soils enhanced by organic acids.

    PubMed

    Yuan, Songhu; Xi, Zhimin; Jiang, Yi; Wan, Jinzhong; Wu, Chan; Zheng, Zhonghua; Lu, Xiaohua

    2007-07-01

    The adsorption/desorption behavior of copper and cadmium on soils was investigated in this study. The adsorption isotherm of copper and cadmium conformed to Langmuir equation better than Freundlich equation. The effect of ionic strength, pH, and organic acid, including ethylenediamine tetraacetic disodium acid salt (EDTA), citric acid, oxalic acid and tartaric acid, on the desorption of copper and cadmium was studied. The desorption of copper and cadmium increased with the increase of ionic strength, while the desorption decreased with the rise of pH. The desorption of copper and cadmium enhanced by organic acids was influenced by pH. EDTA showed excellent enhancement on the desorption of both copper and cadmium; citric acid demonstrated great enhancement on the desorption of copper but negligible enhancement on the desorption of cadmium; oxalic acid enhanced the desorption of copper only at pH around 6.4 and enhanced the desorption of cadmium in the pH range from 6.4 to 10.7; tartaric acid slightly enhanced the desorption of copper but negligibly enhanced the desorption of cadmium. The desorption mechanism in the presence of organic acids were explained as the competition of complexation, adsorption and precipitation. The net effect determined the desorption efficiency. This study provided guidance for the selection of organic acids to enhance the electrokinetic (EK) remediation of copper and cadmium from contaminated soils. PMID:17349675

  11. Some organic acids attenuate the effects of furosemide on the endocochlear potential.

    PubMed

    Rybak, L P; Whitworth, C

    1987-01-01

    A series of organic acid transport inhibitors significantly reduced the endocochlear potential (EP) decline produced by furosemide in the chinchilla. Probenecid, sodium salicylate and penicillin G were much more effective than novobiocin, meclofenamate or diatrizoate. Inhibitors of organic base transport, choline and N-methyl nicotinamide, had no effect on the furosemide-induced drop of the EP. These findings suggest that at least part of furosemide ototoxicity may be mediated by organic acid transport. PMID:2951360

  12. Sorption of vapors of some organic liquids on soil humic acid and its relation to partitioning of organic compounds in soil organic matter

    USGS Publications Warehouse

    Chlou, G.T.; Kile, D.E.; Malcolm, R.L.

    1988-01-01

    Vapor sorption of water, ethanol, benzene, hexane, carbon tetrachloride, 1,1,1-trichloroethane, trichloroethylene, tetrachloroethylene, and 1,2-dibromoethane on (Sanhedron) soil humic acid has been determined at room temperature. Isotherms for all organic liquids are highly linear over a wide range of relative pressure (P/P??), characteristic of the partitioning (dissolution) of the organic compounds in soil humic acid. Polar liquids exhibit markedly greater sorption capacities on soil humic acid than relatively nonpolar liquids, in keeping with the polar nature of the soil humic acid as a partition medium. The limiting sorption (partition) capacities of relatively non-polar liquids are remarkably similar when expressed in terms of volumes per unit weight of soil humic acid. The soil humic acid is found to be about half as effective as soil organic matter in sorption of relatively nonpolar organic compounds. The nearly constant limiting sorption capacity for nonpolar organic liquids with soil humic acid on a volume-to-weight basis and its efficiency in sorption relative to soil organic matter provide a basis for predicting the approximate sorption (partition) coefficients of similar compounds in uptake by soil in aqueous systems.

  13. O-4-Linked coniferyl and sinapyl aldehydes in lignifying cell walls are the main targets of the Wiesner (phloroglucinol-HCl) reaction.

    PubMed

    Pomar, F; Merino, F; Barceló, A Ros

    2002-10-01

    The nature and specificity of the Wiesner test (phloroglucinol-HCl reagent) for the aromatic aldehyde fraction contained in lignins is studied. Phloroglucinol reacted in ethanol-hydrochloric acid with coniferyl aldehyde, sinapyl aldehyde, vanillin, and syringaldehyde to yield either pink pigments (in the case of hydroxycinnamyl aldehydes) or red-brown pigments (in the case of hydroxybenzaldehydes). However, coniferyl alcohol, sinapyl alcohol, and highly condensed dehydrogenation polymers derived from these cinnamyl alcohols and aldehydes did not react with phloroglucinol in ethanol-hydrochloric acid. The differences in the reactivity of phloroglucinol with hydroxycinnamyl aldehydes and their dehydrogenation polymers may be explained by the fact that, in the latter, the unsubstituted (alpha,beta-unsaturated) cinnamaldehyde functional group, which is responsible for the dye reaction, is lost due to lateral chain cross-linking reactions involving the beta carbon. Fourier transform infrared spectroscopy and thioacidolysis analyses of phloroglucinol-positive lignifying plant cell walls belonging to the plant species Zinnia elegans L., Capsicum annuumvar. annuum, Populus albaL., and Pinus halepensisL. demonstrated the presence of 4- O-linked hydroxycinnamyl aldehyde end groups and 4- O-linked 4-hydroxy-3-methoxy-benzaldehyde (vanillin) end groups in lignins. However, given the relatively low abundance of 4- O-linked vanillin in lignifying cell walls and the low extinction coefficient of its red-brown phloroglucinol adduct, it is unlikely that vanillin contributes to a great extent to the phloroglucinol-positive stain reaction. These results suggest that the phloroglucinol-HCl pink stain of lignifying xylem cell walls actually reveals the 4- O-linked hydroxycinnamyl aldehyde structures contained in lignins. Histochemical studies showed that these aldehyde structures are assembled, as in the case of coniferyl aldehyde, during the early stages of xylem cell wall

  14. Determination of linear aliphatic aldehydes in heavy metal containing waters by high-performance liquid chromatography using 2,4-dinitrophenylhydrazine derivatization.

    PubMed

    Lin, Yi-Liang; Wang, Po-Yen; Hsieh, Ling-Ling; Ku, Kuan-Hsuan; Yeh, Yun-Tai; Wu, Chien-Hou

    2009-09-01

    A simple and sensitive method is described for the determination of picomolar amounts of C(1)-C(9) linear aliphatic aldehydes in waters containing heavy metal ions. In this method, aldehydes were first derivatized with 2,4-dinitrophenylhydrazine (DNPH) at optimized pH 1.8 for 30 min and analyzed by HPLC with UV detector at 365 nm. Factors affecting the derivatization reaction of aldehydes and DNPH were investigated. Cupric ion, an example of heavy metals, is a common oxidative reagent, which may oxidize DNPH and greatly interfere with the determination of aldehydes. EDTA was used to effectively mask the interferences by heavy metal ions. The method detection limits for direct injection of derivatized most aldehydes except formaldehyde were of the order of 7-28 nM. The detection limit can be further lowered by using off-line C(18) adsorption cartridge enrichment. The recoveries of C(1)-C(9) aldehydes were 93-115% with a relative standard deviation of 3.6-8.1% at the 0.1 microM level for aldehydes. The HPLC-DNPH method has been applied for determining aldehyde photoproducts from Cu(II)-amino acid complex systems. PMID:19643424

  15. [Inhibitory effects of organic acids and salts on selected micromycetes].

    PubMed

    Láníková, A; Toulová, M

    1992-12-01

    Inhibitory effects of two fungistatic preparations (A and B) and of propionic acid were tested in a complete feed mixture for broiler chickens (starter mixture). The water content of this mixture was 25.4%, environmental temperature was 24 degrees C and relative air humidity 90%. Propionic acid, which has a high fungistatic effect, served as a standard. The composition of the preparation A was as follows: propionic acid, acetic acid, sorbic acid, citric acid and calcium propionate. The preparation B contained: sorbic acid, citric acid and calcium propionate. Examinations were performed in a naturally contaminated and subsequently sterilized (25 kGy) feed mixture; it was then infected with Aspergillus fumigatus, A. niger, A. parasiticus and Penicillium purpurogenum from the Collection of Animal Pathogenic Microorganisms, Brno. A. flavus, A. fumigatus, A. glaucus, Penicillium sp., Absidia corymbifera, Mucor sp., Rhizomucor pusillus were detected in the naturally contaminated feed mixture. The mycoflora which was found in the native substrate was resistant to both tested fungistatic preparations; and this resulted in mycelium growth from 7th day of incubation. The efficiency of the preparations A,B and of propionic acid in the feed mixture was identical at concentrations of 4 mg/kg, 7 mg/kg and 3 mg/kg, respectively, and their inhibitory effects were lowest at these concentrations (Fig. 2). A high water content in the nutrient substrate resulted in the rapid growth of fungi of the Mucorales species. The relative humidity of the environment (90%) and water content of tested samples affected markedly micromycetes growth in this experiment.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1297244

  16. Toxicity of perfluorinated carboxylic acids for aquatic organisms.

    PubMed

    Tichý, Miloň; Valigurová, Radka; Cabala, Radomír; Uzlová, Rut; Rucki, Marián

    2010-06-01

    Toxicity of perfluorinated carboxylic acids with carbon chain C(8) to C(12) were tested with oligochaeta Tubifex tubifex. Toxicity was evaluated as the exposure time ET(50) from onset of damage of the oligochaeta in saturated aqueous solutions. The ET(50) fluctuated between 25 and 257 minutes. No statistically significant difference was found among the C(8), C(9) and C(12) acids (ET(50) between 143 and 257 minutes with large standard deviation). The acids with carbon chain C(10) and C(11) induced the effect significantly quicker (25 to 47 minutes). No acute toxicity measured in the three-minute test was observed in any case. PMID:21217876

  17. Organosulfates and organic acids in Arctic aerosols: speciation, annual variation and concentration levels

    NASA Astrophysics Data System (ADS)

    Hansen, A. M. K.; Kristensen, K.; Nguyen, Q. T.; Zare, A.; Cozzi, F.; Nøjgaard, J. K.; Skov, H.; Brandt, J.; Christensen, J. H.; Ström, J.; Tunved, P.; Krejci, R.; Glasius, M.

    2014-02-01

    Sources, composition and occurrence of secondary organic aerosols (SOA) in the Arctic were investigated at Zeppelin Mountain, Svalbard, and Station Nord, northeast Greenland, during the full annual cycle of 2008 and 2010 respectively. We focused on the speciation of three types of SOA tracers: organic acids, organosulfates and nitrooxy organosulfates from both anthropogenic and biogenic precursors, here presenting organosulfate concentrations and compositions during a full annual cycle and chemical speciation of organosulfates in Arctic aerosols for the first time. Aerosol samples were analysed using High Performance Liquid Chromatography coupled to a quadrupole Time-of-Flight mass spectrometer (HPLC-q-TOF-MS). A total of 11 organic acids (terpenylic acid, benzoic acid, phthalic acid, pinic acid, suberic acid, azelaic acid, adipic acid, pimelic acid, pinonic acid, diaterpenylic acid acetate (DTAA) and 3-methyl-1,2,3-butanetricarboxylic acid (MBTCA)), 12 organosulfates and one nitrooxy organosulfate were identified at the two sites. Six out of the 12 organosulfates are reported for the first time. Concentrations of organosulfates follow a distinct annual pattern at Station Nord, where high concentration were observed in late winter and early spring, with a mean total concentration of 47 (±14) ng m-3, accounting for 7 (±2)% of total organic matter, contrary to a considerably lower organosulfate mean concentration of 2 (±3) ng m-3 (accounting for 1 (±1)% of total organic matter) observed during the rest of the year. The organic acids followed the same temporal trend as the organosulfates at Station Nord; however the variations in organic acid concentrations were less pronounced, with a total mean organic acid concentration of 11.5 (±4) ng m-3 (accounting for 1.7 (±0.6)% of total organic matter) in late winter and early spring, and 2.2 (±1) ng m-3 (accounting for 0.9 (±0.4)% of total organic matter) during the rest of the year. At Zeppelin Mountain

  18. Overexpression of malate dehydrogenase in transgenic alfalfa enhances organic acid synthesis and confers tolerance to aluminum.

    PubMed

    Tesfaye, M; Temple, S J; Allan, D L; Vance, C P; Samac, D A

    2001-12-01

    Al toxicity is a severe impediment to production of many crops in acid soil. Toxicity can be reduced through lime application to raise soil pH, however this amendment does not remedy subsoil acidity, and liming may not always be practical or cost-effective. Addition of organic acids to plant nutrient solutions alleviates phytotoxic Al effects, presumably by chelating Al and rendering it less toxic. In an effort to increase organic acid secretion and thereby enhance Al tolerance in alfalfa (Medicago sativa), we produced transgenic plants using nodule-enhanced forms of malate dehydrogenase and phosphoenolpyruvate carboxylase cDNAs under the control of the constitutive cauliflower mosaic virus 35S promoter. We report that a 1.6-fold increase in malate dehydrogenase enzyme specific activity in root tips of selected transgenic alfalfa led to a 4.2-fold increase in root concentration as well as a 7.1-fold increase in root exudation of citrate, oxalate, malate, succinate, and acetate compared with untransformed control alfalfa plants. Overexpression of phosphoenolpyruvate carboxylase enzyme specific activity in transgenic alfalfa did not result in increased root exudation of organic acids. The degree of Al tolerance by transformed plants in hydroponic solutions and in naturally acid soil corresponded with their patterns of organic acid exudation and supports the concept that enhancing organic acid synthesis in plants may be an effective strategy to cope with soil acidity and Al toxicity. PMID:11743127

  19. Anaerobic microbial dissolution of lead and production of organic acids

    DOEpatents

    Francis, A.J.; Dodge, C.; Chendrayan, K.; Quinby, H.L.

    1987-04-16

    The present invention related to an anaerobic bacterial culture of Clostridium sp. ATCC No. 53464 which solubilizes lead oxide under anaerobic conditions in coal and industrial wastes and therefore presents a method of removing lead from such wastes before they are dumped into the environment. The rat of lead dissolution during logarithmic growth of the bacteria in 40 ml medium containing 3.32 ..mu..moles of lead as lead oxide was 0.042 ..mu..moles m1/sup /-/1/ hr/sup /-/1/. Dissolution of lead oxide by the bacterial isolate is due to the production of metabolites and acidity in the culture medium. The major metabolites are acetic, butyric and lactic acid. The major metabolites are acetic, butyric and lactic acid. Clostridium sp. ATCC No. 53464 can be used in the recovery of the strategic metals from ores and wastes and also for the production of lactic acid for commercial purposes. The process yields large quantities of lactic acid as well as lead complexed in a stable form with said acids. 4 figs., 3 tabs.

  20. One-Pot Amide Bond Formation from Aldehydes and Amines via a Photoorganocatalytic Activation of Aldehydes.

    PubMed

    Papadopoulos, Giorgos N; Kokotos, Christoforos G

    2016-08-19

    A mild, one-pot, and environmentally friendly synthesis of amides from aldehydes and amines is described. Initially, a photoorganocatalytic reaction of aldehydes with di-isopropyl azodicarboxylate leads to an intermediate carbonyl imide, which can react with a variety of amines to afford the desired amides. The initial visible light-mediated activation of a variety of monosubstituted or disubstituted aldehydes is usually fast, occurring in a few hours. Following the photocatalytic reaction, addition of the primary amine at room temperature or the secondary amine at elevated temperatures leads to the corresponding amide from moderate to excellent yields without epimerization. This methodology was applied in the synthesis of Moclobemide, a drug against depression and social anxiety. PMID:27227271

  1. Ozonolysis mechanism of lignin model compounds and microbial treatment of organic acids produced.

    PubMed

    Nakamura, Y; Daidai, M; Kobayashi, F

    2004-01-01

    Treatment methods comprising ozonolysis and microbial treatment of lignin discharged from the pulp manufacture industries were investigated by using a sulfite pulp wastewater and a lignin model compound, i.e. sodium lignosulfonate. Dynamic behaviors for the formations of intermediate derivatives such as muconic acid, maleic acid, and oxalic acid produced from the ozonolysis of sulfite pulp wastewater were observed from data of UV absorption at 280 nm by a spectrophotometer and at 210 nm by high performance liquid chromatography. The microorganisms that were isolated by the enrichment culture method were used to degrade the organic acids such as oxalic acid and acetic acid. Time courses of biological degradation of these organic acids indicated diauxic growth, which was found in a culture with mixed substrates. In the treatment of sodium lignosulfonate, the ozonolysis and microbial treatment using activated sludge converted sodium lignosulfonate into carbon dioxide and water almost completely. PMID:15461411

  2. Phase equilibria and distribution constants of metal ions in diantipyryl alkane-organic acid-hydrochloric acid-water systems

    NASA Astrophysics Data System (ADS)

    Degtev, M. I.; Popova, O. N.; Yuminova, A. A.

    2014-08-01

    The ability of antipyrine and its derivatives (diantipyryl alkanes) to form separating systems in the presence of salicylic (sulfosalicylic) acid and hydrochloric acid and water is studied. The optimum volume of the organic phase, the composition of complexes, and the mechanism for the distribution of metal ions are determined, depending on the concentrations of the main components and the salting-out agent. The complex distribution and extraction constants are calculated.

  3. An enhanced procedure for measuring organic acids and methyl esters in PM2.5

    NASA Astrophysics Data System (ADS)

    Liu, F.; Duan, F. K.; He, K. B.; Ma, Y. L.; Rahn, K. A.; Zhang, Q.

    2015-11-01

    A solid-phase extraction (SPE) pretreatment procedure allowing organic acids to be separated from methyl esters in fine aerosol has been developed. The procedure first separates the organic acids from fatty acid methyl esters (FAMEs) and other nonacid organic compounds by aminopropyl-based SPE cartridge and then quantifies them by gas chromatography/mass spectrometry. The procedure prevents the fatty acids and dimethyl phthalate from being overestimated, and so allows us to accurately quantify the C4-C11 dicarboxylic acids (DCAs) and the C8-C30 monocarboxylic acids (MCAs). Results for the extraction of DCAs, MCAs, and AMAs in eluate and FAMEs in effluate by SAX and NH2 SPE cartridges exhibited that the NH2 SPE cartridge gave higher extraction efficiency than the SAX cartridge. The recoveries of analytes ranged from 67.5 to 111.3 %, and the RSD ranged from 0.7 to 10.9 %. The resulting correlations between the aliphatic acids and FAMEs suggest that the FAMEs had sources similar to those of the carboxylic acids, or were formed by esterifying carboxylic acids, or that aliphatic acids were formed by hydrolyzing FAMEs. Through extraction and cleanup using this procedure, 17 aromatic acids in eluate were identified and quantified by gas chromatography/tandem mass spectrometry, including five polycyclic aromatic hydrocarbon (PAH): acids 2-naphthoic, biphenyl-4-carboxylic, 9-oxo-9H-fluorene-1-carboxylic, biphenyl-4,4´-dicarboxylic, and phenanthrene-1-carboxylic acid, plus 1,8-naphthalic anhydride. Correlations between the PAH acids and the dicarboxylic and aromatic acids suggested that the first three acids and 1,8-naphthalic anhydride were secondary atmospheric photochemistry products and the last two mainly primary.

  4. Relative efficacy of organic acids and antibiotics as growth promoters in broiler chicken

    PubMed Central

    Bagal, Vikrant Laxman; Khatta, Vinod Kumar; Tewatia, Bachu Singh; Sangwan, Sandeep Kumar; Raut, Subhash Shamrao

    2016-01-01

    Aim: The objective of this study was to evaluate the effect of organic acids as replacer to antibiotics in their various combinations on feed consumption, body weight gain, and feed conversion ratio (FCR) in broiler chicks during different phases of growth. Materials and Methods: Antibiotics and organic acids were incorporated into boiler feed in different combinations to form 10 maize based test diets (T1 to T10). Each test diet was offered to four replicates of 10 birds each constituting a total of 400 birds kept for 45 days. Results: Significantly better effect in terms of body weight gain from supplementation of 1% citric acid and 1% citric acid along with antibiotic was observed throughout the entire study, whereas the effect of tartaric acid supplementation was similar to control group. Citric acid (1%) along with antibiotic supplementation showed highest feed intake during the experimental period. Significantly better FCR was observed in groups supplemented with 1% citric acid and 1% citric acid along with antibiotic followed by antibiotic along with organic acids supplemented group. Conclusion: Growth performance of birds in terms of body weight, body weight gain, and FCR improved significantly in 1% citric acid which was significantly higher than antibiotic supplemented group. 1% citric acid can effectively replace antibiotic growth promoter (chlortetracycline) without affecting growth performance of birds. PMID:27182133

  5. INFLUENCE OF AQUEOUS ALUMINUM AND ORGANIC ACIDS ON MEASUREMENT OF ACID NEUTRALIZING CAPACITY IN SURFACE WATERS

    EPA Science Inventory

    Acid neutralizing capacity (ANC) is used to quantify the acid-base status of surface waters. Acidic waters have bean defined as having ANC values less than zero, and acidification is often quantified by decreases in ANC. Measured and calculated values of ANC generally agree, exce...

  6. Top value platform chemicals: bio-based production of organic acids.

    PubMed

    Becker, Judith; Lange, Anna; Fabarius, Jonathan; Wittmann, Christoph

    2015-12-01

    Driven by the quest for sustainability, recent years have seen a tremendous progress in bio-based production routes from renewable raw materials to commercial goods. Particularly, the production of organic acids has crystallized as a competitive and fast-evolving field, related to the broad applicability of organic acids for direct use, as polymer building blocks, and as commodity chemicals. Here, we review recent advances in metabolic engineering and industrial market scenarios with focus on organic acids as top value products from biomass, accessible through fermentation and biotransformation. PMID:26360870

  7. The Role of Organic Acids in the Acid-Base Status of Surface Waters at Bickford Watershed, Massachusetts

    NASA Astrophysics Data System (ADS)

    Eshleman, K. N.; Hemond, H. F.

    1985-10-01

    An experimental field study of the alkalinity and major ion budgets of Bickford watershed in central Massachusetts indicates that organic acid production by the ecosystem contributes measurably to surface water acidification. Applying the concepts of alkalinity, electroneutrality of solutions, and mass balance, organic acids were found to comprise 20% of all strong acid sources on one subcatchment annually, a value half as large as the measured bulk mineral acid deposition. Inorganic cation to anion ratios in Provencial Brook varied between 1.0 in winter and 1.6 during summer, suggesting the presence of up to 100 μeq/L of unmeasured charge from organic anions during the growing season. Base titrations and ultraviolet photooxidation experiments confirmed the existence of low pKa (3.5-5.0) acidic functional groups. A positive linear relationship between dissolved organic carbon (DOC) and anion deficit for a group of surface and groundwater samples indicates the DOC contains about 7.5 meq carboxylic groups per gram C. Biological factors related to both upland and wetland carbon metabolism apparently control this natural acidification phenomenon, which has not been documented on other watersheds in the northeastern United States for which annual alkalinity budgets have been determined.

  8. The C-terminal loop of aldehyde reductase determines the substrate and inhibitor specificity.

    PubMed

    Barski, O A; Gabbay, K H; Bohren, K M

    1996-11-12

    Human aldehyde reductase has a preference for carboxyl group-containing negatively charged substrates. It belongs to the NADPH-dependent aldo-keto reductase superfamily whose members are in part distinguished by unique C-terminal loops. To probe the role of the C-terminal loops in determining substrate specificities in these enzymes, two arginine residues, Arg308 and Arg311, located in the C-terminal loop of aldehyde reductase, and not found in any other C-terminal loop, were replaced with alanine residues. The catalytic efficiency of the R311A mutant for aldehydes containing a carboxyl group is reduced 150-250-fold in comparison to that of the wild-type enzyme, while substrates not containing a negative charge are unaffected. The R311A mutant is also significantly less sensitive to inhibition by dicarboxylic acids, indicating that Arg311 interacts with one of the carboxyl groups. The inhibition pattern indicates that the other carboxyl group binds to the anion binding site formed by Tyr49, His112, and the nicotinamide moiety of NADP+. The correlation between inhibitor potency and the length of the dicarboxylic acid molecules suggests a distance of approximately 10 A between the amino group of Arg311 and the anion binding site in the aldehyde reductase molecule. The sensitivity of inhibition of the R311A mutant by several commercially available aldose reductase inhibitors (ARIs) was variable, with tolrestat and zopolrestat becoming more potent inhibitors (30- and 5-fold, respectively), while others remained the same or became less potent. The catalytic properties, substrate specificity, and susceptibility to inhibition of the R308A mutant remained similar to that of the wild-type enzyme. The data provide direct evidence for C-terminal loop participation in determining substrate and inhibitor specificity of aldo-keto reductases and specifically identifies Arg311 as the basis for the carboxyl-containing substrate preference of aldehyde reductase. PMID:8916913

  9. 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

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

    PubMed

    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

  11. Anaerobic microbial dissolution of lead and production of organic acids

    DOEpatents

    Francis, Arokiasamy J.; Dodge, Cleveland; Chendrayan, Krishnachetty; Quinby, Helen L.

    1988-01-01

    The present invention relates to an anaerobic bacterial culture of Clostridium sp. ATCC No. 53464 which solubilizes lead oxide under anaerobic conditions in coal and industrial wastes and therefore presents a method of removing lead from such wastes before they are dumped into the environment. The rate of lead dissolution during logarithmic growth of the bacteria in 40 ml medium containing 3.32 .mu.moles of lead as lead oxide was 0.042 .mu.moles ml.sup.-1 hr.sup.-1. Dissolution of lead oxide by the bacterial isolate is due to the production of metabolites and acidity in the culture medium. The major metabolites are acetic, butyric and lactic acid. Clostridium sp. ATCC No. 53464 can be used in the recovery of strategic metals from ores and wastes and also for the production of lactic acid for commercial purposes. The process yields large quantities of lactic acid as well as lead complexed in a stable form with said acids.

  12. Microgravity Compatible Reagentless Instrumentation for Detection of Dissolved Organic Acids and Alcohols in Potable Water

    NASA Technical Reports Server (NTRS)

    Akse, James R.; Jan, Darrell L. (Technical Monitor)

    2002-01-01

    The Organic Acid and Alcohol Monitor (OAAM) program has resulted in the successful development of a computer controlled prototype analyzer capable of accurately determining aqueous organic acids and primary alcohol concentrations over a large dynamic range with high sensitivity. Formic, acetic, and propionic acid were accurately determined at concentrations as low as 5 to 10 micrograms/L in under 20 minutes, or as high as 10 to 20 mg/L in under 30 minutes. Methanol, ethanol, and propanol were determined at concentrations as low as 20 to 100 micrograms/L, or as high as 10 mg/L in under 30 minutes. Importantly for space based application, the OAAM requires no reagents or hazardous chemicals to perform these analyses needing only power, water, and CO2 free purge gas. The OAAM utilized two membrane processes to segregate organic acids from interfering ions. The organic acid concentration was then determined based upon the conductiometric signal. Separation of individual organic acids was accomplished using a chromatographic column. Alcohols are determined in a similar manner after conversion to organic acids by sequential biocatalytic and catalytic oxidation steps. The OAAM was designed to allow the early diagnosis of under performing or failing sub-systems within the Water Recovery System (WRS) baselined for the International Space Station (ISS). To achieve this goal, several new technologies were developed over the course of the OAAM program.

  13. Role of organic acids in promoting colloidal transport of mercury from mine tailings

    USGS Publications Warehouse

    Slowey, A.J.; Johnson, S.B.; Rytuba, J.J.; Brown, Gordon E., Jr.

    2005-01-01

    A number of factors affect the transport of dissolved and paniculate mercury (Hg) from inoperative Hg mines, including the presence of organic acids in the rooting zone of vegetated mine waste. We examined the role of the two most common organic acids in soils (oxalic and citric acid) on Hg transport from such waste by pumping a mixed organic acid solution (pH 5.7) at 1 mL/min through Hg mine tailings columns. For the two total organic acid concentrations investigated (20 ??M and 1 mM), particle-associated Hg was mobilized, with the onset of paniculate Hg transport occurring later for the lower organic acid concentration. Chemical analyses of column effluent indicate that 98 wt % of Hg mobilized from the column was paniculate. Hg speciation was determined using extended X-ray absorption fine structure spectroscopy and transmission electron microscopy, showing that HgS minerals are dominant in the mobilized particles. Hg adsorbed to colloids is another likely mode of transport due to the abundance of Fe-(oxyhydr)oxides, Fe-sulfides, alunite, and jarosite in the tailings to which Hg(II) adsorbs. Organic acids produced by plants are likely to enhance the transport of colloid-associated Hg from vegetated Hg mine tailings by dissolving cements to enable colloid release. ?? 2005 American Chemical Society.

  14. Prevalence and mechanism of polyunsaturated aldehydes production in the green tide forming macroalgal genus Ulva (Ulvales, Chlorophyta).

    PubMed

    Alsufyani, Taghreed; Engelen, Aschwin H; Diekmann, Onno E; Kuegler, Stefan; Wichard, Thomas

    2014-10-01

    Lipoxygenase/hydroperoxide lyase mediated transformations convert polyunsaturated fatty acids into various oxylipins. First, lipoxygenases catalyze fatty acid oxidation to fatty acid hydroperoxides. Subsequently, breakdown reactions result in a wide array of metabolites with multiple physiological and ecological functions. These fatty acid transformations are highly diverse in marine algae and play a crucial rule in e.g., signaling, chemical defense, and stress response often mediated through polyunsaturated aldehydes (PUAs). In this study, green tide-forming macroalgae of the genius Ulva (Chlorophyta) were collected at various sampling sites in the lagoon of the Ria Formosa (Portugal) and were surveyed for PUAs. We demonstrated that sea-lettuce like but not tube-like morphotypes produce elevated amounts of volatile C10-polyunsaturated aldehydes (2,4,7-decatrienal and 2,4-decadienal) upon tissue damage. Moreover, morphogenetic and phylogenetic analyses of the collected Ulva species revealed chemotaxonomic significance of the perspective biosynthetic pathways. The aldehydes are derived from omega-3 and omega-6 polyunsaturated fatty acids (PUFA) with 20 or 18 carbon atoms including eicosapentaenoic acid (C20:5 n-3), arachidonic acid (C20:4 n-6), stearidonic acid (C18:4 n-3), and γ-linolenic acid (C18:3 n-6). We present first evidences that lipoxygenase-mediated (11-LOX and 9-LOX) eicosanoid and octadecanoid pathways catalyze the transformation of C20- and C18-polyunsaturated fatty acids into PUAs and concomitantly into short chain hydroxylated fatty acids. PMID:24915501

  15. Mobilization of soil-borne arsenic by three common organic acids: Dosage and time effects.

    PubMed

    Onireti, Olaronke O; Lin, Chuxia

    2016-03-01

    A batch experiment was conducted to investigate the mobilization of soil-borne arsenic by three common low-molecular-weight organic acids with a focus on dosage and time effects. The results show that oxalic acid behaved differently from citric acid and malic acid in terms of mobilizing As that was bound to iron compounds. At an equivalent molar concentration, reactions between oxalic acid and soil-borne Fe were kinetically more favourable, as compared to those between either citric acid or malic acid and the soil-borne Fe. It was found that reductive dissolution of soil-borne Fe played a more important role in liberating As, as compared to non-reductive reactions. Prior to the 7th day of the experiment, As mobility increased with increasing dose of oxalic acid while there was no significant difference (P > 0.05) in mobilized As among the treatments with different doses of citric acid or malic acid. The dosage effect on soil-borne As mobilization in the citric acid and malic acid treatments became clear only after the 7th day of the experiment. Soluble Ca present in the soils could cause re-immobilization of As by competing with solution-borne Fe for available organic ligands to form practically insoluble organic compounds of calcium (i.e. calcium oxalate). This resulted in transformation of highly soluble organic complexes of iron (i.e. iron oxalate complexes) into slightly soluble organic compounds of iron (i.e. iron oxalate) or free ferric ion, which then reacted with the solution-borne arsenate ions to form practically insoluble iron arsenates in the latter part of the experiment. PMID:26774299

  16. An enhanced procedure for measuring organic acids and methyl esters in PM2.5

    NASA Astrophysics Data System (ADS)

    Liu, F.; Duan, F.; He, K.; Ma, Y.; Rahn, K. A.; Zhang, Q.

    2015-03-01

    We have developed an enhanced analytical procedure to measure organic acids and methyl esters in fine aerosol with much greater specificity and sensitivity than previously available. This capability is important because of these species and their low concentrations, even in highly polluted atmospheres like Beijing, China. The procedure first separates the acids and esters from the other organic compounds with anion-exchange solid- phase extraction (SPE), then, quantifies them by gas chromatography coupled with mass spectrometry. This allows us to accurately quantify the C4-C11 dicarboxylic and the C8-C30 monocarboxylic acids. Then the acids are separated from the esters on an aminopropyl SPE cartridge, whose weak retention isolates and enriches the acids from esters prevents the fatty acids and dimethyl phthalate from being overestimated. The resulting correlations between the aliphatic acids and fatty acid methyl esters (FAMEs) suggest that FAMEs had sources similar to those of the carboxylic acids, or were formed by esterifying carboxylic acids, or that aliphatic acids were formed by hydrolyzing FAMEs. In all, 17 aromatic acids were identified and quantified using this procedure coupled with gas chromatography-tandem mass spectrometry, including the five polycyclic aromatic hydrocarbon (PAH) acids 2-naphthoic, biphenyl-4-carboxylic, 9-oxo-9H-fluorene-1-carboxylic, biphenyl-4,4´-dicarboxylic, and phenanthrene-1-carboxylic acid, plus 1,8-naphthalic anhydride. Correlations between the PAH-acids and the dicarboxylic and aromatic acids indicated that the first three acids and 1,8-naphthalic anhydride were mainly secondary, the last two mainly primary.

  17. Influence of organic acids on the transport of heavy metals in soil.

    PubMed

    Schwab, A P; Zhu, D S; Banks, M K

    2008-06-01

    Vegetation historically has been an important part of reclamation of sites contaminated with metals, whether the objective was to stabilize the metals or remove them through phytoremediation. Understanding the impact of organic acids typically found in the rhizosphere would contribute to our knowledge of the impact of plants in contaminated environments. Heavy metal transport in soils in the presence of simple organic acids was assessed in two laboratory studies. In the first study, thin layer chromatography (TLC) was used to investigate Zn, Cd, and Pb movement in a sandy loam soil as affected by soluble organic acids in the rhizosphere. Many of these organic acids enhanced heavy metal movement. For organic acid concentrations of 10mM, citric acid had the highest R(f) values (frontal distance moved by metal divided by frontal distance moved by the solution) for Zn, followed by malic, tartaric, fumaric, and glutaric acids. Citric acid also has the highest R(f) value for Cd movement followed by fumaric acid. Citric acid and tartaric acid enhanced Pb transport to the greatest degree. For most organic acids studied, R(f) values followed the trend Zn>Cd>Pb. Citric acid (10mM) increased R(f) values of Zn and Cd by approximately three times relative to water. In the second study, small soil columns were used to test the impact of simple organic acids on Zn, Cd, and Pb leaching in soils. Citric acid greatly enhanced Zn and Cd movement in soils but had little influence on Pb movement. The Zn and Cd in the effluents from columns treated with 10mM citric acid attained influent metal concentrations by the end of the experiment, but effluent metal concentrations were much less than influent concentrations for citrate <10mM. Exchangeable Zn in the soil columns was about 40% of total Zn, and approximately 80% total Cd was in exchangeable form. Nearly all of the Pb retained by the soil columns was exchangeable. PMID:18482743

  18. Adsorption of small weak organic acids on goethite: Modeling of mechanisms

    SciTech Connect

    Filius, J.D.; Hiemstra, T.; Riemsdijk, W.H. Van

    1997-11-15

    The adsorption of lactate, oxalate, malonate, phthalate, and citrate has been determined experimentally as a function of concentration, pH, and ionic strength. The data have been described with the CD-MUSIC model of Hiemstra and Van Riemsdijk which allows a distribution of charge of the organic molecule over the surface and the Stern layer. Simultaneously, the concentration, pH, and salt dependency as well as the basic charging behavior of goethite could be described well. On the basis of model calculations, a distinction is made between inner and outer sphere complexation of weak organic acids by goethite. The results indicate that the affinity of the organic acids is dominated by the electrostatic attraction. The intrinsic affinity constants for the exchange reaction of surface water groups and organic acids, expressed per bond, increases with increasing number of reactive groups on the organic molecule. Ion pair formation between noncoordinated carboxylic groups of adsorbed organic acids and cations of the background electrolyte proved to be important for the salt dependency. The knowledge obtained may contribute to the interpretation of the binding of larger organic acids like fulvic and humic acids.

  19. Asymmetric intramolecular α-cyclopropanation of aldehydes using a donor/acceptor carbene mimetic

    PubMed Central

    Luo, Chaosheng; Wang, Zhen; Huang, Yong

    2015-01-01

    Enantioselective α-alkylation of carbonyl is considered as one of the most important processes for asymmetric synthesis. Common alkylation agents, that is, alkyl halides, are notorious substrates for both Lewis acids and organocatalysts. Recently, olefins emerged as a benign alkylating species via photo/radical mechanisms. However, examples of enantioselective alkylation of aldehydes/ketones are scarce and direct asymmetric dialkylation remains elusive. Here we report an intramolecular α-cyclopropanation reaction of olefinic aldehydes to form chiral cyclopropane aldehydes. We demonstrate that an α-iodo aldehyde can function as a donor/acceptor carbene equivalent, which engages in a formal [2+1] annulation with a tethered double bond. Privileged bicyclo[3.1.0]hexane-type scaffolds are prepared in good optical purity using a chiral amine. The synthetic utility of the products is demonstrated by versatile transformations of the bridgehead formyl functionality. We expect the concept of using α-iodo iminium as a donor/acceptor carbene surrogate will find wide applications in chemical reaction development. PMID:26644194

  20. A new device for formaldehyde and total aldehydes real-time monitoring.

    PubMed

    Sassine, Maria; Picquet-Varrault, Bénédicte; Perraudin, Emilie; Chiappini, Laura; Doussin, Jean François; George, Christian

    2014-01-01

    A new sensitive technique for the quantification of formaldehyde (HCHO) and total aldehydes has been developed in order to monitor these compounds, which are known to be involved in air quality issues and to have health impacts. Our approach is based on a colorimetric method where aldehydes are initially stripped from the air into a scrubbing solution by means of a turning coil sampler tube and then derivatised with 3-methylbenzothiazolinone-2-hydrazone in acid media (pH = -0.5). Hence, colourless aldehydes are transformed into blue dyes that are detected by UV-visible spectroscopy at 630 nm. Liquid core waveguide LCW Teflon® AF-2400 tube was used as innovative optical cells providing a HCHO detection limit of 4 pptv for 100 cm optical path with a time resolution of 15 min. This instrument showed good correlation with commonly used techniques for aldehydes analysis such as DNPH derivatisation chromatographic techniques with off-line and on-line samplers, and DOAS techniques (with deviation below 6%) for both indoor and outdoor conditions. This instrument is associated with simplicity and low cost, which is a prerequisite for indoor monitoring. PMID:23892614

  1. Fast determination of aldehyde preservatives by miniaturized capillary electrophoresis with amperometric detection.

    PubMed

    Li, Ying; Chen, Fang; Ge, Jinyuan; Tong, Fanghong; Deng, Zhaoyue; Shen, Fengwu; Gu, Qianxia; Ye, Jiannong; Chu, Qingcui

    2014-02-01

    A novel miniaturized CE with amperometric detection (mini-CE-AD) method has been developed for fast determination of aliphatic aldehyde preservatives, namely formaldehyde and glyoxal, in commodities. After derivatization with an electroactive compound 2-thiobarbituric acid, these two nonelectroactive aldehydes were converted to electroactive adducts, therefore detectable by mini-CE-AD approach. Under the optimum conditions, two aldehydes can be well-separated with the coexisting interferents as well as their homologs (acetaldehyde and methyl-glyoxal), and the LODs (S/N = 3) were achieved at nanogram-per-milliliter level (1.64-2.80 ng/mL) based on the online enrichment method of transient moving chemical reaction boundary. The proposed method has been applied for the analyses of above aldehyde preservatives in different real commodity samples including skincare products, baby lotion, and toothpaste, and the average recoveries were in the range of 94-105%, which should find a wide range of analytical applications as an alternative to conventional and microchip CE approaches. PMID:24002819

  2. Asymmetric intramolecular α-cyclopropanation of aldehydes using a donor/acceptor carbene mimetic.

    PubMed

    Luo, Chaosheng; Wang, Zhen; Huang, Yong

    2015-01-01

    Enantioselective α-alkylation of carbonyl is considered as one of the most important processes for asymmetric synthesis. Common alkylation agents, that is, alkyl halides, are notorious substrates for both Lewis acids and organocatalysts. Recently, olefins emerged as a benign alkylating species via photo/radical mechanisms. However, examples of enantioselective alkylation of aldehydes/ketones are scarce and direct asymmetric dialkylation remains elusive. Here we report an intramolecular α-cyclopropanation reaction of olefinic aldehydes to form chiral cyclopropane aldehydes. We demonstrate that an α-iodo aldehyde can function as a donor/acceptor carbene equivalent, which engages in a formal [2+1] annulation with a tethered double bond. Privileged bicyclo[3.1.0]hexane-type scaffolds are prepared in good optical purity using a chiral amine. The synthetic utility of the products is demonstrated by versatile transformations of the bridgehead formyl functionality. We expect the concept of using α-iodo iminium as a donor/acceptor carbene surrogate will find wide applications in chemical reaction development. PMID:26644194

  3. Modulation of ethanol stress tolerance by aldehyde dehydrogenase in the mycorrhizal fungus Tricholoma vaccinum.

    PubMed

    Asiimwe, Theodore; Krause, Katrin; Schlunk, Ines; Kothe, Erika

    2012-08-01

    We report the first mycorrhizal fungal aldehyde dehydrogenase gene, ald1, which was isolated from the basidiomycete Tricholoma vaccinum. The gene, encoding a protein Ald1 of 502 amino acids, is up-regulated in ectomycorrhiza. Phylogenetic analyses using 53 specific fungal aldehyde dehydrogenases from all major phyla in the kingdom of fungi including Ald1 and two partial sequences of T. vaccinum were performed to get an insight in the evolution of the aldehyde dehydrogenase family. By using competitive and real-time RT-PCR, ald1 is up-regulated in response to alcohol and aldehyde-related stress. Furthermore, heterologous expression of ald1 in Escherichia coli and subsequent in vitro enzyme activity assay demonstrated the oxidation of propionaldehyde and butyraldehyde with different kinetics using either NAD(+) or NADP(+) as cofactors. In addition, overexpression of ald1 in T. vaccinum after Agrobacterium tumefaciens-mediated transformation increased ethanol stress tolerance. These results demonstrate the ability of Ald1 to circumvent ethanol stress, a critical function in mycorrhizal habitats. PMID:22159964

  4. The diatom-derived aldehyde decadienal affects life cycle transition in the ascidian Ciona intestinalis through nitric oxide/ERK signalling

    PubMed Central

    Castellano, Immacolata; Ercolesi, Elena; Romano, Giovanna; Ianora, Adrianna; Palumbo, Anna

    2015-01-01

    Polyunsaturated aldehydes (PUAs) are fatty-acid-derived metabolites produced by some microalgae, including different diatom species. PUAs are mainly produced as a wound-activated defence mechanism against microalgal predators or released from senescent cells at the end of a bloom. PUAs, including 2,4-trans-decadienal (DD), induce deleterious effects on embryonic and larval development of several planktonic and benthic organisms. Here, we report on the effects of DD on larval development and metamorphosis of the ascidian Ciona intestinalis. Ciona larval development is regulated by the cross-talking of different molecular events, including nitric oxide (NO) production, ERK activation and caspase 3-dependent apoptosis. We report that treatment with DD at the competence larval stage results in a delay in metamorphosis. DD affects redox balance by reducing total glutathione and NO levels. By biochemical and quantitative gene expression analysis, we identify the NO-signalling network affected by DD, including the upregulation of ERK phosphatase mkp1 and consequent reduction of ERK phosphorylation, with final changes in the expression of downstream ERK target genes. Overall, these results give new insights into the molecular pathways induced in marine organisms after exposure to PUAs during larval development, demonstrating that this aldehyde affects key checkpoints of larval transition from the vegetative to the reproductive life stage. PMID:25788553

  5. Sensitive Amino Acid Composition and Chirality Analysis with the Mars Organic Analyzer (MOA)

    NASA Technical Reports Server (NTRS)

    Skelley, Alison M.; Scherer, James R.; Aubrey, Andrew D.; Grover, William H.; Ivester, Robin H. C.; Ehrenfreund, Pascale; Grunthaner, Frank J.; Bada, Jeffrey L.; Mathies, Richard A.

    2005-01-01

    Detection of life on Mars requires definition of a suitable biomarker and development of sensitive yet compact instrumentation capable of performing in situ analyses. Our studies are focused on amino acid analysis because amino acids are more resistant to decomposition than other biomolecules, and because amino acid chirality is a well-defined biomarker. Amino acid composition and chirality analysis has been previously demonstrated in the lab using microfabricated capillary electrophoresis (CE) chips. To analyze amino acids in the field, we have developed the Mars Organic Analyzer (MOA), a portable analysis system that consists of a compact instrument and a novel multi-layer CE microchip.

  6. Protected Organic Acid Blends as an Alternative to Antibiotics in Finishing Pigs

    PubMed Central

    Upadhaya, S. D.; Lee, K. Y.; Kim, I. H.

    2014-01-01

    A total of 120 finishing pigs ([Yorkshire×Landrace]×Duroc) with an average body weight (BW) of 49.72 ±1.72 kg were used in 12-wk trial to evaluate the effects of protected organic acids on growth performance, nutrient digestibility, fecal micro flora, meat quality and fecal gas emission. Pigs were randomly allotted to one of three dietary treatments (10 replication pens with 4 pigs per pen) in a randomly complete block design based on their initial BW. Each dietary treatment consisted of: Control (CON/basal diet), OA1 (basal diet+0.1% organic acids) and OA2 (basal diet+0.2% organic acids). Dietary treatment with protected organic acid blends linearly improved (p<0.001) average daily gain during 0 to 6 week, 6 to 12 week as well as overall with the increase in their inclusion level in the diet. The dry matter, N, and energy digestibility was higher (linear effect, p<0.001) with the increase in the dose of protected organic acid blends during 12 week. During week 6, a decrease (linear effect, p = 0.01) in fecal ammonia contents was observed with the increase in the level of protected organic acid blends on d 3 and d 5 of fermentation. Moreover, acetic acid emission decreased linearly (p = 0.02) on d7 of fermentation with the increase in the level of protected organic acid blends. During 12 weeks, linear decrease (p<0.001) in fecal ammonia on d 3 and d 5 and acetic acid content on d 5 of fermentation was observed with the increase in the level of protected organic acid blends. Supplementation of protected organic acid blends linearly increased the longissimus muscle area with the increasing concentration of organic acids. Moreover, color of meat increased (linear effect, quadratic effect, p<0.001, p<0.002 respectively) and firmness of meat showed quadratic effect (p = 0.003) with the inclusion of increasing level of protected organic acid in the diet. During the 6 week, increment in the level of protected organic acid blends decreased (linear effect, p = 0

  7. Students' Understanding of Acids/Bases in Organic Chemistry Contexts

    ERIC Educational Resources Information Center

    Cartrette, David P.; Mayo, Provi M.

    2011-01-01

    Understanding key foundational principles is vital to learning chemistry across different contexts. One such foundational principle is the acid/base behavior of molecules. In the general chemistry sequence, the Bronsted-Lowry theory is stressed, because it lends itself well to studying equilibrium and kinetics. However, the Lewis theory of…

  8. Insights into Substrate and Metal Binding from the Crystal Structure of Cyanobacterial Aldehyde Deformylating Oxygenase with Substrate Bound

    PubMed Central

    2015-01-01

    The nonheme diiron enzyme cyanobacterial aldehyde deformylating oxygenase, cADO, catalyzes the highly unusual deformylation of aliphatic aldehydes to alkanes and formate. We have determined crystal structures for the enzyme with a long-chain water-soluble aldehyde and medium-chain carboxylic acid bound to the active site. These structures delineate a hydrophobic channel that connects the solvent with the deeply buried active site and reveal a mode of substrate binding that is different from previously determined structures with long-chain fatty acids bound. The structures also identify a water channel leading to the active site that could facilitate the entry of protons required in the reaction. NMR studies examining 1-[13C]-octanal binding to cADO indicate that the enzyme binds the aldehyde form rather than the hydrated form. Lastly, the fortuitous cocrystallization of the metal-free form of the protein with aldehyde bound has revealed protein conformation changes that are involved in binding iron. PMID:25222710

  9. Recovery of propylene glycol from dilute aqueous solutions via reversible reaction with aldehydes

    SciTech Connect

    Broekhuis, R.R.; Lynn, S.; King, C.J. |

    1993-12-01

    A means is proposed for separating propylene glycol and other compounds bearing multiple hydroxyl groups by reversible chemical reaction. Glycols react with aldehydes in cyclic acetalization reactions to form substituted dioxolanes. Propylene glycol reacts with formaldehyde and acetaldehyde to form 4-methyl-1,3-dioxolane and 2,4-dimethyl-1,3-dioxolane. The reaction is catalyzed homogeneously by strong mineral acids or heterogeneously by cation exchange resins in the acid form. Separation processes utilizing this reaction would include an acetalization step, several distillative separation steps and finally a hydrolysis step in which the reaction is reversed. Both reaction steps must be forced to completion by removing the reaction product simultaneously. The equilibrium and kinetics of the reaction with formaldehyde were studied experimentally in systems catalyzed by Amberlite IR-120 ion exchange resin. A number of solvents were screened for their ability to extract 2,4-dimethyl-1,3-dioxolane from aqueous solution. Aromatic hydrocarbons exhibited the highest distribution into the organic phase. To achieve an effective separation of propylene glycol from aqueous solution by combined reaction with formaldehyde and distillation, formaldehyde would have to be present in excess and would be difficult and costly to separate from the aqueous solution. In reactive distillation using acetaldehyde as a reactant this is not a problem. A large flow of acetaldehyde would be necessary to recover the propylene glycol sufficiently in a distillative process. In a process combining reaction and extraction into an organic solvent this problem is avoided. Process simulation indicates the energy input of such a process is less than half of the energy required in a triple-effect evaporation process. This benefit is offset by higher capital costs and increased complexity in the reaction/extraction process.

  10. The sensory interactions of organic acids and various flavors in ramen soup systems.

    PubMed

    Kang, M-W; Chung, S-J; Lee, H-S; Kim, Y; Kim, K-O

    2007-11-01

    This study was conducted to investigate the sensory interactions between various organic acids and flavorants in 3 types of ramen soup ('beef,' seafood, and 'kimchi') when types and levels of organic acids (citric, malic, and lactic) varied. For 'beef' and seafood ramen soup, weak suprathreshold levels of acids (0.0039% to 0.0071%) were applied to the system and medium suprathreshold of acids (0.0128% to 0.0299%) were applied to the kimchi ramen soup. The amount of acid applied to each system was chosen based on the equiweight level. Descriptive analyses were performed separately for each ramen soup system using 8 trained panelists. A total of 11, 13, and 12 flavor descriptors were generated for 'beef,' seafood, and 'kimchi' soup, respectively. Analysis of variance was conducted to evaluate the effect of organic acid on the sensory characteristics of ramen soup. Principal component analysis was conducted to summarize the relationship between the soup samples and attributes. The effect of organic acids on the flavor attributes of ramen soup was dependent on the soup system as well as adding levels of acid. Addition of lactic acid power (at 0.0066%) in 'beef'ramen soup showed enhancement effect on the sour, salty, beefy, 'mushroom' flavor, and fermented soybean paste soup flavor, whereas lactic acid powder (at 0.0071%) showed enhancement effect only on the sour and fermented soybean paste soup flavor in seafood ramen soup due to the strong 'hot' flavor characteristics of the soup. In kimchi ramen soup, flavor attributes congruent to sourness were enhanced by the addition of organic acids to the system. PMID:18034748

  11. The effect of low solublility organic acids on the hygroscopicity of sodium halide aerosols

    NASA Astrophysics Data System (ADS)

    Miñambres, L.; Méndez, E.; Sánchez, M. N.; Castaño, F.; Basterretxea, F. J.

    2014-02-01

    In order to accurately assess the influence of fatty acids on the hygroscopic and other physicochemical properties of sea salt aerosols, hexanoic, octanoic or lauric acid together with sodium halide salts (NaCl, NaBr and NaI) have been chosen to be performed in this study. The hygroscopic properties of sodium halide submicrometer particles covered with organic acids have been examined by Fourier-transform infrared spectroscopy in an aerosol flow cell. Covered particles were generated by flowing atomized sodium halide particles (either dry or aqueous) through a heated oven containing the gaseous acid. The obtained results indicate that gaseous organic acids easily nucleate onto dry and aqueous sodium halide particles. On the other hand, Scanning Electron Microscopy (SEM) images indicate that lauric acid coating on NaCl particles makes them to aggregate in small clusters. The hygroscopic behaviour of covered sodium halide particles in deliquescence mode shows different features with the exchange of the halide ion: whereas the organic covering has little effect in NaBr particles, NaCl and NaI covered particles change their deliquescence relative humidities, with different trends observed for each of the acids studied. In efflorescence mode, the overall effect of the organic covering is to retard the loss of water in the particles. It has been observed that the presence of gaseous water in heterogeneously nucleated particles tends to displace the cover of hexanoic acid to energetically stabilize the system.

  12. The effect of low solubility organic acids on the hygroscopicity of sodium halide aerosols

    NASA Astrophysics Data System (ADS)

    Miñambres, L.; Méndez, E.; Sánchez, M. N.; Castaño, F.; Basterretxea, F. J.

    2014-10-01

    In order to accurately assess the influence of fatty acids on the hygroscopic and other physicochemical properties of sea salt aerosols, hexanoic, octanoic or lauric acid together with sodium halide salts (NaCl, NaBr and NaI) have been chosen to be investigated in this study. The hygroscopic properties of sodium halide sub-micrometre particles covered with organic acids have been examined by Fourier-transform infrared spectroscopy in an aerosol flow cell. Covered particles were generated by flowing atomized sodium halide particles (either dry or aqueous) through a heated oven containing the gaseous acid. The obtained results indicate that gaseous organic acids easily nucleate onto dry and aqueous sodium halide particles. On the other hand, scanning electron microscopy (SEM) images indicate that lauric acid coating on NaCl particles makes them to aggregate in small clusters. The hygroscopic behaviour of covered sodium halide particles in deliquescence mode shows different features with the exchange of the halide ion, whereas the organic surfactant has little effect in NaBr particles, NaCl and NaI covered particles experience appreciable shifts in their deliquescence relative humidities, with different trends observed for each of the acids studied. In efflorescence mode, the overall effect of the organic covering is to retard the loss of water in the particles. It has been observed that the presence of gaseous water in heterogeneously nucleated particles tends to displace the cover of hexanoic acid to energetically stabilize the system.

  13. Resource recovery from waste LCD panel by hydrothermal transformation of polarizer into organic acids.

    PubMed

    Li, Feng; Bai, Lan; He, Wenzhi; Li, Guangming; Huang, Juwen

    2015-12-15

    Based on the significant advantages of hydrothermal technology, it was applied to treat polarizer from the waste LCD panel with the aim of transforming it into organic acids (mainly acetic acid and lactic acid). Investigation was done to evaluate the effects of different factors on yields of organic acids, including the reaction temperature, reaction time and H2O2 supply, and the degradation process of polarizer was analyzed. Liquid samples were analyzed by GC/MS and HPLC, and solid-phase products were characterized by SEM and FTIR. Results showed that at the condition of temperature 300 °C and reaction time 5 min, the organic materials reached its highest conversion rate of 71.47% by adding 0.2 mL H2O2 and acetic acid was dominant in the products of organic acids with the yield of 6.78%. When not adding H2O2 to the system, the yields of lactic and acetic acid were respectively 4.24% and 3.80% at a nearly equal degree, they are suitable for esterification to form ethyl lactate instead of separating them for this case. In the hydrothermal process, polarizer was first decomposed to monosaccharides, alkane, etc., and then furfural and acids are produced with further decomposition. PMID:26094243

  14. Isolation of hydrophilic organic acids from water using nonionic macroporous resins

    USGS Publications Warehouse

    Aiken, G.R.; McKnight, Diane M.; Thorn, K.A.; Thurman, E.M.

    1992-01-01

    A method has been developed for the isolation of hydrophilic organic acids from aquatic environments using Amberlite* * Use of trade names in this report is for identification purposes only and does not constitute endorsement by the U.S. Geological Survey. XAD-4 resin. The method uses a two column array of XAD-8 and XAD-4 resins in series. The hydrophobic organic acids, composed primarily of aquatic fulvic acid, are removed from the sample on XAD-8, followed by the isolation of the more hydrophilic organic acids on XAD-4. For samples from a number of diverse environments, more of the dissolved organic carbon was isolated on the XAD-8 resin (23-58%) than on the XAD-4 resin (7-25%). For these samples, the hydrophilic acids have lower carbon and hydrogen contents, higher oxygen and nitrogen contents, and are lower in molecular weight than the corresponding fulvic acids. 13C NMR analyses indicate that the hydrophilic acids have a lower concentration of aromatic carbon and greater heteroaliphatic, ketone and carboxyl content than the fulvic acid. ?? 1992.

  15. Usnic Acid and the Intramolecular Hydrogen Bond: A Computational Experiment for the Organic Laboratory

    ERIC Educational Resources Information Center

    Green, Thomas K.; Lane, Charles A.

    2006-01-01

    A computational experiment is described for the organic chemistry laboratory that allows students to estimate the relative strengths of the intramolecular hydrogen bonds of usnic and isousnic acids, two related lichen secondary metabolites. Students first extract and purify usnic acid from common lichens and obtain [superscript 1]H NMR and IR…

  16. Physicochemical aspects of inhibition of acid corrosion of metals by unsaturated organic compounds

    NASA Astrophysics Data System (ADS)

    Avdeev, Ya G.; Kuznetsov, Yurii I.

    2012-12-01

    The state-of-the-art in the development and improvement of methods for protecting metals from corrosion in mineral acid solutions using unsaturated organic compounds is considered. Characteristic features of the mechanism of their protective action on metal corrosion in acidic media are discussed. The bibliography includes 203 references.

  17. Oxidative degradation of organic acids conjugated with sulfite oxidation in flue gas desulfurization

    SciTech Connect

    Lee, Y.I.

    1986-01-01

    Organic acid degradation conjugated with sulfite oxidation has been studied under flue gas desulfurization (EGD) conditions. The oxidative degradation constant, k/sub 12/, is defined as the ratio of organic acid degradation rate and sulfite oxidation rate after being normalized by the concentrations of organic acid and dissolved S(IV). K/sub 12/, not significantly affected by pH or dissolved oxygen, is around 10/sup -3/ in the absence of manganese or iron. However, k/sub 12/ is increased by certain transition metals such as Co, Ni, and Fe and is decreased by Mn and halides. Lower dissolved S(IV) magnified these effects. No k/sub 12/ greater than 4 x 10/sup -3/ or smaller than 0.1 x 10/sup -3/ has been observed. A free radical mechanism was proposed to describe the kinetics: (1) sulfate free radical is the major radical responsible to the degradation of organic acid; (2) ferrous generates sulfate radical by reacting with monoxypersulfate to enhance k/sub 12/; (3) manganous consumes sulfate radical to decrease k/sub 12/; (4) dissolved S(IV) competes with ferrous for monoxypersulfate and with manganous for sulfate radical to demonstrate the effects of dissolved S(IV) on k/sub 12/. Hydroxy and sulfonated carboxylic acids degrade approximately three times slower than saturated dicarboxylic acids; while maleic acid, an unsaturated dicarboxylic acid, degraded an order of magnitude faster. A wide spectrum of degradation products of adipic acid were found, including carbon dioxide - the major product, glutaric semialdehyde - the major retained product with low manganese, glutaric acid and valeric acids - the major retained product with high manganese, lower molecular weight mono- and dicarboxylic acids, other carbonyl compounds, and hydrocarbons.

  18. Non-P450 aldehyde oxidizing enzymes: the aldehyde dehydrogenase superfamily

    PubMed Central

    Marchitti, Satori A; Brocker, Chad; Stagos, Dimitrios; Vasiliou, Vasilis

    2009-01-01

    Background Aldehydes are highly reactive molecules. While several non-P450 enzyme systems participate in their metabolism, one of the most important is the aldehyde dehydrogenase (ALDH) superfamily, composed of NAD(P)+-dependent enzymes that catalyze aldehyde oxidation. Objective This article presents a review of what is currently known about each member of the human ALDH superfamily including the pathophysiological significance of these enzymes. Methods Relevant literature involving all members of the human ALDH family was extensively reviewed, with the primary focus on recent and novel findings. Conclusion To date, 19 ALDH genes have been identified in the human genome and mutations in these genes and subsequent inborn errors in aldehyde metabolism are the molecular basis of several diseases, including Sjögren-Larsson syndrome, type II hyperprolinemia, γ-hydroxybutyric aciduria and pyridoxine-dependent seizures. ALDH enzymes also play important roles in embryogenesis and development, neurotransmission, oxidative stress and cancer. Finally, ALDH enzymes display multiple catalytic and non-catalytic functions including ester hydrolysis, antioxidant properties, xenobiotic bioactivation and UV light absorption. PMID:18611112

  19. Carbon dioxide and organic acids: origin and role in burial diagenesis (Texas Gulf Coast Tertiary)

    SciTech Connect

    Lundegard, P.D.

    1985-01-01

    Carbon dioxide produced by decarboxylation of organic matter is not a dominant factor in secondary porosity development. Material balance calculations indicate the amount of feldspar and carbonate dissolution that has taken place in Tertiary sandstones of the Texas Gulf Coast far exceeds that which is explainable by decarboxylation. Other potential sources of acid for dissolution reactions include reverse weathering reactions in shales, an hydrous pyrolysis reactions between organic carbon and oxygen in H/sub 2/O to yield CO/sub 2/ or organic acids. Considerations of CO/sub 2/ solubility and the temperature distribution of organic acids imply that these species must be generated locally to cause significant dissolution. The CO/sub 2/ content of gas from Gulf Coast Tertiary sandstones is proportional to reservoir age, and increases with depth and temperature at a rate that is approximately exponential. In the Wilcox Formation the increase in CO/sub 2/ content continues beyond depths where dissolved organic acids are abundant and where kerogen has lost its oxygen from functional groups that are readily liberated as CO/sub 2/. In this formation the /sup 13/C of CO/sub 2/ and CH/sub 4/ are proportional to temperature and to each other. Either mixing with fluids derived from the Mesozoic carbonate section of deep CO/sub 2/ generation by kinetically controlled organic reactions may explain these data. Organic acid concentration with depth and temperature indicates a non-biological origin by thermal cracking of kerogen during burial. Continued burial leads to their thermal decomposition. Cessation of burial may lead to meteoric water invasion and organic acid destruction by biological processes. The effect of time on organic acid production is minor compared to temperature.

  20. Microbial production of organic acids in aquitard sediments and its role in aquifer geochemistry

    USGS Publications Warehouse

    McMahon, P.B.; Chapelle, F.H.

    1991-01-01

    MICROBIAL activity in aquifers plays an important part in the chemical evolution of ground water1-5. The most important terminal electron-accepting microbial processes in deeply buried anaerobic aquifers are iron reduction, sulphate reduction and methanogenesis5-8, each of which requires simple organic compounds or hydrogen (H2) as electron donors. Until now, the source of these compounds was unknown because the concentrations of dissolved organic carbon and sedimentary organic carbon in aquifers are extremely low9-11. Here we show that rates of microbial fermentation exceed rates of respiration in organic-rich aquitards (low-permeability sediments stratigraphically adjacent to higher-permeability aquifer sediments), resulting in a net accumulation of simple organic acids in pore waters. In aquifers, however, respiration outpaces fermentation, resulting in a net consumption of organic acids. The concentration gradient that develops in response to these two processes drives a net diffusive flux of organic acids from aquitards to aquifers. Diffusion calculations demonstrate that rates of organic acid transport are sufficient to account for observed rates of microbial respiration in aquifers. This overall process effectively links the large pool of sedimentary organic carbon in aquitards to microbial respiration in aquifers, and is a principal mechanism driving groundwater chemistry changes in aquifers.

  1. Targeting Aldehyde Dehydrogenase: a Potential Approach for Cell labeling

    PubMed Central

    Vaidyanathan, Ganesan; Song, Haijing; Affleck, Donna; McDougald, Darryl L.; Storms, Robert W.; Zalutksy, Michael R.; Chin, Bennett B.

    2009-01-01

    Introduction To advance the science and clinical application of stem cell therapy, the availability of a highly sensitive, quantitative, and translational method for tracking stem cells would be invaluable. Because hematopoetic stem cells express high levels of the cytosolic enzyme aldehyde dehydrogenase-1A1 (ALDH1), we sought to develop an agent that is specific to ALDH1 and thus to cells expressing the enzyme. Such an agent might be also helpful in identifying tumors that are resistant to cyclophosphomide chemotherapy because ALDH1 is known to be responsible for this resistance. Methods We developed schemes for the synthesis of two 3radioiodinated aldehdyes—N-formylmethyl-5-[*I]iodopyridine-3-carboxamide ([*I]FMIC) and 4-diethylamino-3-[*I]iodobenzaldehyde ([*I]DEIBA)—at no-carrier-added levels from their respective tin precursors. These agents were evaluated using pure ALDH1 and tumor cells that expressed the enzyme. Results The average radiochemical yields for the synthesis [125I]FMIC and [125I]DEIBA were 70 ± 5% and 47 ± 14%, respectively. ALDH1 converted both compounds to respective acids suggesting their suitability as ALDH1 imaging agents. Although ability of ALDH1 within the cells to oxidize one of these substrates was shown, specific uptake in ALDH-expressing tumor cells could not be demonstrated. Conclusion To pursue this approach for ALDH1 imaging, radiolabeled aldehydes need to be designed such that, in addition to being good substrates for ALDH1, the cognate products should be sufficiently polar so as to be retained within the cells. PMID:19875048

  2. Organic acids and selected nitrogen species for ABLE-3

    NASA Technical Reports Server (NTRS)

    Talbot, Robert W.

    1991-01-01

    The NASA Global Tropospheric Experiment (GTE) executed airborne science missions aboard the NASA Wallops Electra (NA429) in the North American high latitude (greater than 45 deg North) atmosphere during Jul. to Aug. 1988 and Jul. to Aug. 1990. These missions were part of GTE's Atmospheric Boundary Layer Experiment (ABLE). The 1988 mission , ABLE-3A, examined the ecosystems of Alaska as a source and/or sink for important tropospheric gases and particles, and gained new information on the chemical composition of the Arctic atmosphere during the summertime. During 1990 the second high latitude mission, ABLE-3B, focused on the Hudson Bay Lowland and Labrador regions of Canada. Both of these missions provided benchmark data sets on atmosphere biosphere exchange and atmospheric chemistry over largely uninhabited regions of North America. In support of the GTE/ABLE-3A and -3B field missions, the University of New Hampshire flew instrumentation aboard the Wallops Electra research aircraft to provide measurements of the trace gases nitric (HNO3), formic (HCOOH), and acetic (CH3COOH) acid. In addition, measurements were conducted to determine the major water soluble ionic composition of the atmospheric aerosol. For ABLE-3B, groundbased measurements of the acidic trace gases were also performed from the NASA micrometerological tower situated at Schefferville, Laborador. These measurements were aimed at assessing dry deposition of acidic gases to the taiga ecosystem in the Laborador region of Canada.

  3. Roaming as the dominant mechanism for molecular products in the photodissociation of large aliphatic aldehydes.

    PubMed

    Tsai, Po-Yu; Li, Hou-Kuan; Kasai, Toshio; Lin, King-Chuen

    2015-09-21

    Photodissociation of isobutyraldehyde (C3H7CHO) at 248 nm is investigated using time-resolved Fourier-transform infrared emission spectroscopy to demonstrate the growing importance of the roaming pathway with increasing molecular size of aliphatic aldehydes. Each acquired CO rotational distribution from v = 1 to 4 is well characterized by a single Boltzmann rotational temperature from 637 to 750 K, corresponding to an average rotational energy of 5.9 ± 0.6 kJ mol(-1). The roaming signature that shows a small fraction of CO rotational energy disposal accompanied by a vibrationally hot C3H8 co-fragment is supported by theoretical prediction. The energy difference between the tight transition state (TS) and the roaming saddle point (SP) is found to be -27, 4, 15, 22, and 30 kJ mol(-1) for formaldehyde, acetaldehyde, propionaldehyde, isobutyraldehyde, and 2,2-dimethyl propanal, respectively. The roaming SP is stabilized by a larger alkyl moiety. It is suggested that the roaming photodissociation rate of aldehydes increasingly exceeds those via the tight TS, resulting in the dominance of the CO + alkane products, as the size of aldehydes becomes larger. Along with formaldehyde, acetaldehyde, and propionaldehyde, in this work isobutyraldehyde is further demonstrated that this aldehyde family with special functional group is the first case in the organic compound to follow predominantly a roaming dissociation pathway, as the molecular size becomes larger. PMID:26279383

  4. Characterization of organic contaminants in environmental samples associated with mount St. Helens 1980 volcanic eruption

    USGS Publications Warehouse

    Pereira, W.E.

    1982-01-01

    Volcanic ash, surface-water, and bottom-material samples obtained in the vicinity of Mount St. Helens after the May 18, 1980, eruption were analyzed for organic contaminants by using capillary gas chromatography-mass spectrometry-computer techniques. Classes of compounds identified include n-alkanes, fatty acids, dicarboxylic acids, aromatic acids and aldehydes, phenols, resin acids, terpenes, and insect juvenile hormones. The most probable source of these compounds is from pyrolysis of plant and soil organic matter during and after the eruption. The toxicity of selected compounds and their environmental significance are discussed.

  5. Toxicity of algal-derived aldehydes to two invertebrate species: do heavy metal pollutants have a synergistic effect?

    PubMed

    Taylor, Rebecca L; Caldwell, Gary S; Bentley, Matthew G

    2005-08-15

    The recent discovery of the production of anti-proliferative aldehydes in a variety of microalgal species has lead to considerable investigation into the effects of these toxins on aquatic invertebrates. Studies have, however, rarely considered the impact pollutants may have on grazer responses to algal toxins. In this study, the acute toxicities of five aldehydes to the rotifer Brachionus plicatilis and nauplii of the brine shrimp Artemia salina are examined using immersion assays. In addition, the effect of a representative of these aldehydes in the presence of sub-lethal levels of heavy metals was examined. B. plicatilis generally showed greater sensitivity to the aldehydes than A. salina. The polyunsaturated 2-trans,4-trans-decadienal was the most toxic to both species having 24h LD(50) values of 7 and 20 microM for B. plicatilis and A. salina, respectively. The remaining aldehydes had different orders of toxicity for the two species with a stronger relationship observed between mortality and aldehyde carbon-chain length for A. salina whereas B. plicatilis mortality showed a stronger dependence on the presence of carbon-carbon double bonds in the aldehydes. The presence of 1 microM of copper sulphate in solutions of decadienal resulted in the reduction of the 24h LD(50) of decadienal by approximately a third for both species. 1 microM of copper chloride in solutions of decadienal reduced the 24h LD(50) of decadienal to A. salina nauplii by approximately 11% and 1 microM zinc sulphate caused a reduction of only 3%. Pre-exposure of the organisms to 1 microM copper sulphate had no significant impact on their subsequent mortality in decadienal. The ecological implications and the possible mechanisms for the action of copper sulphate on the response of organisms to decadienal are discussed. PMID:15927283

  6. Recovery of nickel and cobalt from organic acid complexes: adsorption mechanisms of metal-organic complexes onto aminophosphonate chelating resin.

    PubMed

    Deepatana, A; Valix, M

    2006-09-21

    This study examined the recovery of nickel and cobalt from organic acid complexes using a chelating aminophosphonate Purolite S950 resin. These metal complexes are generated by bioleaching nickel laterite ores, a commercial nickel and cobalt mineral oxide, with heterotrophic organism and their metabolites or organic acid products. Equilibrium adsorption tests were conducted as a function of Ni and Co concentrations (15-2000 mg/L), solution pH (0.01 and 0.1 M acids) and three metabolic complexing agents (citrate, malate and lactate). It was shown that the adsorption of the various Ni- and Co-complexes on Purolite were quite low, 16-18 and 5.4-9 mg/g of resin, respectively, in comparison to the smaller nickel ions and nickel sulfate. This was attributed to the bulky organic ligands which promoted crowding effect or steric hindrance. The adsorption of these complexes was further hampered by the strong affinity of the resin to H+ ions under acidic conditions. Mechanisms of adsorption, as inferred from the fitted empirical Langmuir and Freundlich models, were correlated to the proposed steric hindrance and competitive adsorption effects. Nickel and cobalt elution from the resin were found be effective and were independent of the type of metal complexes and metal concentrations. This study demonstrated the relative challenges involved in recovering nickel and cobalt from bioleaching solutions. PMID:16698178

  7. Double stereodifferentiation in the "acetate-type" aldol reaction with garner's aldehyde. Stereocontrolled synthesis of polyhydroxylated gamma-amino carbonyl compounds.

    PubMed

    Vicario, Jose L; Rodriguez, Mónica; Badía, Dolores; Carrillo, Luisa; Reyes, Efraim

    2004-09-01

    [reaction: see text] The aldol reaction of acetamide enolates with protected chiral alpha-amino-beta-hydroxy aldehyde 1 (Garner's aldehyde) has been performed in a stereocontrolled way under double stereodifferentiation conditions using pseudoephedrine as the additional chiral information source attached to the enolate reagent. In addition, the obtained adduct has been transformed into other valuable chiral building blocks such as gamma-amino-beta,delta-dihydroxy acids, esters, and ketones. PMID:15330615

  8. Cyclic α-Alkoxyphosphonium Salts from (2-(Diphenylphosphino)phenyl)methanol and Aldehydes and Their Application in Synthesis of Vinyl Ethers and Ketones via Wittig Olefination.

    PubMed

    Huang, Wenhua; Rong, Hong-Ying; Xu, Jie

    2015-07-01

    Cyclic α-alkoxyphosphonium salts have been synthesized from (2-(diphenylphosphino)phenyl)methanol and aldehydes in 36-89% yields. These phosphonium salts are bench-stable solids and undergo Wittig olefination with aldehydes under basic conditions (K2CO3 or t-BuOK) to form benzylic vinyl ethers, which are readily hydrolyzed to 1,2-disubstituted ethanones under acidic conditions. The formation mechanism of these phosphonium salts via hemiacetal is also proposed. PMID:26067375

  9. Isotherm-Based Thermodynamic Models for Solute Activities of Organic Acids with Consideration of Partial Dissociation.

    PubMed

    Nandy, Lucy; Ohm, Peter B; Dutcher, Cari S

    2016-06-23

    Organic acids make up a significant fraction of the organic mass in atmospheric aerosol particles. The calculation of gas-liquid-solid equilibrium partitioning of the organic acid is therefore critical for accurate determination of atmospheric aerosol physicochemical properties and processes such as new particle formation and activation to cloud condensation nuclei. Previously, an adsorption isotherm-based statistical thermodynamic model was developed for capturing solute concentration-activity relationships for multicomponent aqueous solutions over the entire concentration range (Dutcher et al. J. Phys. Chem. C/A 2011, 2012, 2013), with model parameters for energies of adsorption successfully related to dipole-dipole electrostatic forces in solute-solvent and solvent-solvent interactions for both electrolytes and organics (Ohm et al. J. Phys. Chem. A 2015). However, careful attention is needed for weakly dissociating semivolatile organic acids. Dicarboxylic acids, such as malonic acid and glutaric acid are treated here as a mixture of nondissociated organic solute (HA) and dissociated solute (H(+) + A(-)). It was found that the apparent dissociation was greater than that predicted by known dissociation constants alone, emphasizing the effect of dissociation on osmotic and activity coefficient predictions. To avoid additional parametrization from the mixture approach, an expression was used to relate the Debye-Hückel hard-core collision diameter to the adjustable solute-solvent intermolecular distance. An improved reference state treatment for electrolyte-organic aqueous mixtures, such as that observed here with partial dissociation, has also been proposed. This work results in predictive correlations for estimation of organic acid and water activities for which there is little or no activity data. PMID:27222917

  10. Capture and release of mixed acid gasses with binding organic liquids

    DOEpatents

    Heldebrant, David J.; Yonker, Clement R.

    2010-09-21

    Reversible acid-gas binding organic liquid systems that permit separation and capture of one or more of several acid gases from a mixed gas stream, transport of the liquid, release of the acid gases from the ionic liquid and reuse of the liquid to bind more acid gas with significant energy savings compared to current aqueous systems. These systems utilize acid gas capture compounds made up of strong bases and weak acids that form salts when reacted with a selected acid gas, and which release these gases when a preselected triggering event occurs. The various new materials that make up this system can also be included in various other applications such as chemical sensors, chemical reactants, scrubbers, and separators that allow for the specific and separate removal of desired materials from a gas stream such as flue gas.

  11. Targeting Aldehyde Dehydrogenase 2: New Therapeutic Opportunities

    PubMed Central

    Chen, Che-Hong; Ferreira, Julio Cesar Batista; Gross, Eric R.; Mochly-Rosen, Daria

    2014-01-01

    A family of detoxifying enzymes called aldehyde dehydrogenases (ALDHs) has been a subject of recent interest, as its role in detoxifying aldehydes that accumulate through metabolism and to which we are exposed from the environment has been elucidated. Although the human genome has 19 ALDH genes, one ALDH emerges as a particularly important enzyme in a variety of human pathologies. This ALDH, ALDH2, is located in the mitochondrial matrix with much known about its role in ethanol metabolism. Less known is a new body of research to be discussed in this review, suggesting that ALDH2 dysfunction may contribute to a variety of human diseases including cardiovascular diseases, diabetes, neurodegenerative diseases, stroke, and cancer. Recent studies suggest that ALDH2 dysfunction is also associated with Fanconi anemia, pain, osteoporosis, and the process of aging. Furthermore, an ALDH2 inactivating mutation (termed ALDH2*2) is the most common single point mutation in humans, and epidemiological studies suggest a correlation between this inactivating mutation and increased propensity for common human pathologies. These data together with studies in animal models and the use of new pharmacological tools that activate ALDH2 depict a new picture related to ALDH2 as a critical health-promoting enzyme. PMID:24382882

  12. A review of the effects of dietary organic acids fed to swine.

    PubMed

    Suiryanrayna, Mocherla V A N; Ramana, J V

    2015-01-01

    Animal production depends on nutrient utilization and if done there is an accelerated momentum towards growth with a low cost to feed ratio Public concern over the consumption of pork with antibiotic residues of the animals fed with antibiotic growth promoters (AGP) has paved the way to use other additives like herbs and their products, probiotics, prebiotics etc. Numerous feed additives are in vogue for achieving this target and one such classical example is the usage of organic acids and their salts. Usage of organic acids was in progress for over four decades. Early weaned piglets are (3-4 weeks age) exposed to stress with a reduced feed intake, little or no weight gain. This post weaning lag period is due to a limited digestive and absorptive capacity due to insufficient production of hydrochloric acid, pancreatic enzymes and sudden changes in feed consistency and intake. Lowering dietary pH by weak organic acids was found to overcome these problems. The main activity of organic acids is associated with a reduction in gastric pH converting the inactive pepsinogen to active pepsin for effective protein hydrolysis. Organic acids are both bacteriostatic and bactericidal. Lactic acid has been reported to reduce gastric pH and delay the multiplication of an enterotoxigenic E. coli. These acids are the intermediary products in Kreb's cycle and thus act as an energy source preventing the tissue breakdown resulting from gluconeogenesis and lipolysis. Excretion of supplemental minerals and nitrogen are minimized with organic acids as these form complexes with minerals and aids for their bio-availability. Short chain fatty cids like acetic, propionic and n-butyric acid produced by microbial fermentation of dietary fibre in the large intestines may increase the proliferation of epithelial cells and have stimulatory effects on both endocrine and exocrine pancreatic secretions in pigs. Organic acids also enhances apparent total tract digestibility and improves growth

  13. Aldehyde dehydrogenase (ALDH) superfamily in plants: gene nomenclature and comparative genomics.

    PubMed

    Brocker, Chad; Vasiliou, Melpomene; Carpenter, Sarah; Carpenter, Christopher; Zhang, Yucheng; Wang, Xiping; Kotchoni, Simeon O; Wood, Andrew J; Kirch, Hans-Hubert; Kopečný, David; Nebert, Daniel W; Vasiliou, Vasilis

    2013-01-01

    In recent years, there has been a significant increase in the number of completely sequenced plant genomes. The comparison of fully sequenced genomes allows for identification of new gene family members, as well as comprehensive analysis of gene family evolution. The aldehyde dehydrogenase (ALDH) gene superfamily comprises a group of enzymes involved in the NAD(+)- or NADP(+)-dependent conversion of various aldehydes to their corresponding carboxylic acids. ALDH enzymes are involved in processing many aldehydes that serve as biogenic intermediates in a wide range of metabolic pathways. In addition, many of these enzymes function as 'aldehyde scavengers' by removing reactive aldehydes generated during the oxidative degradation of lipid membranes, also known as lipid peroxidation. Plants and animals share many ALDH families, and many genes are highly conserved between these two evolutionarily distinct groups. Conversely, both plants and animals also contain unique ALDH genes and families. Herein we carried out genome-wide identification of ALDH genes in a number of plant species-including Arabidopsis thaliana (thale crest), Chlamydomonas reinhardtii (unicellular algae), Oryza sativa (rice), Physcomitrella patens (moss), Vitis vinifera (grapevine) and Zea mays (maize). These data were then combined with previous analysis of Populus trichocarpa (poplar tree), Selaginella moellindorffii (gemmiferous spikemoss), Sorghum bicolor (sorghum) and Volvox carteri (colonial algae) for a comprehensive evolutionary comparison of the plant ALDH superfamily. As a result, newly identified genes can be more easily analyzed and gene names can be assigned according to current nomenclature guidelines; our goal is to clarify previously confusing and conflicting names and classifications that might confound results and prevent accurate comparisons between studies. PMID:23007552

  14. Effect of organic acids on the growth and fermentation of ethanologenic Escherichia coli LY01

    SciTech Connect

    Zaldivar, J.; Ingram, L.O.

    1999-07-01

    Hemicellulose residues can be hydrolyzed into a sugar syrup using dilute mineral acids. Although this syrup represents a potential feedstock for biofuel production, toxic compounds generated during hydrolysis limit microbial metabolism. Escherichia coli LY01, an ethanologenic biocatalyst engineered to ferment the mixed sugars in hemicellulose syrups, has been tested for resistance to selected organic acids that re present in hemicellulose hydrolysates. Compounds tested include aromatic acids derived from lignin (ferulic, gallic, 4-hydroxybenzoic, syringic, and vanillic acids), acetic acid from the hydrolysis of acetylxylan, and others derived from sugar destruction (furoic, formic, levulinic, and caproic acids). Toxicity was related to hydrophobicity. Combinations of acids were roughly additive as inhibitors of cell growth. When tested at concentrations that inhibited growth by 80%, none appeared to strongly inhibit glycolysis and energy generation, or to disrupt membrane integrity. Toxicity was not markedly affected by inoculum size or incubation temperature. The toxicity of all acids except gallic acid was reduced by an increase in initial pH (from pH 6.0 to pH 7.0 to pH 8.0). Together, these results are consistent with the hypothesis that both aliphatic and mononuclear organic acids inhibit growth and ethanol production in LY01 by collapsing ion gradients and increasing internal anion concentrations.

  15. Halogenated methanesulfonic acids: A new class of organic micropollutants in the water cycle.

    PubMed

    Zahn, Daniel; Frömel, Tobias; Knepper, Thomas P

    2016-09-15

    Mobile and persistent organic micropollutants may impact raw and drinking waters and are thus of concern for human health. To identify such possible substances of concern nineteen water samples from five European countries (France, Switzerland, The Netherlands, Spain and Germany) and different compartments of the water cycle (urban effluent, surface water, ground water and drinking water) were enriched with mixed-mode solid phase extraction. Hydrophilic interaction liquid chromatography - high resolution mass spectrometry non-target screening of these samples led to the detection and structural elucidation of seven novel organic micropollutants. One structure could already be confirmed by a reference standard (trifluoromethanesulfonic acid) and six were tentatively identified based on experimental evidence (chloromethanesulfonic acid, dichloromethanesulfonic acid, trichloromethanesulfonic acid, bromomethanesulfonic acid, dibromomethanesulfonic acid and bromochloromethanesulfonic acid). Approximated concentrations for these substances show that trifluoromethanesulfonic acid, a chemical registered under the European Union regulation REACH with a production volume of more than 100 t/a, is able to spread along the water cycle and may be present in concentrations up to the μg/L range. Chlorinated and brominated methanesulfonic acids were predominantly detected together which indicates a common source and first experimental evidence points towards water disinfection as a potential origin. Halogenated methanesulfonic acids were detected in drinking waters and thus may be new substances of concern. PMID:27267477

  16. Molecular understanding of atmospheric particle formation from sulfuric acid and large oxidized organic molecules

    PubMed Central

    Schobesberger, Siegfried; Junninen, Heikki; Bianchi, Federico; Lönn, Gustaf; Ehn, Mikael; Lehtipalo, Katrianne; Dommen, Josef; Ehrhart, Sebastian; Ortega, Ismael K.; Franchin, Alessandro; Nieminen, Tuomo; Riccobono, Francesco; Hutterli, Manuel; Duplissy, Jonathan; Almeida, João; Amorim, Antonio; Breitenlechner, Martin; Downard, Andrew J.; Dunne, Eimear M.; Flagan, Richard C.; Kajos, Maija; Keskinen, Helmi; Kirkby, Jasper; Kupc, Agnieszka; Kürten, Andreas; Kurtén, Theo; Laaksonen, Ari; Mathot, Serge; Onnela, Antti; Praplan, Arnaud P.; Rondo, Linda; Santos, Filipe D.; Schallhart, Simon; Schnitzhofer, Ralf; Sipilä, Mikko; Tomé, António; Tsagkogeorgas, Georgios; Vehkamäki, Hanna; Wimmer, Daniela; Baltensperger, Urs; Carslaw, Kenneth S.; Curtius, Joachim; Hansel, Armin; Petäjä, Tuukka; Kulmala, Markku; Donahue, Neil M.; Worsnop, Douglas R.

    2013-01-01

    Atmospheric aerosols formed by nucleation of vapors affect radiative forcing and therefore climate. However, the underlying mechanisms of nucleation remain unclear, particularly the involvement of organic compounds. Here, we present high-resolution mass spectra of ion clusters observed during new particle formation experiments performed at the Cosmics Leaving Outdoor Droplets chamber at the European Organization for Nuclear Research. The experiments involved sulfuric acid vapor and different stabilizing species, including ammonia and dimethylamine, as well as oxidation products of pinanediol, a surrogate for organic vapors formed from monoterpenes. A striking resemblance is revealed between the mass spectra from the chamber experiments with oxidized organics and ambient data obtained during new particle formation events at the Hyytiälä boreal forest research station. We observe that large oxidized organic compounds, arising from the oxidation of monoterpenes, cluster directly with single sulfuric acid molecules and then form growing clusters of one to three sulfuric acid molecules plus one to four oxidized organics. Most of these organic compounds retain 10 carbon atoms, and some of them are remarkably highly oxidized (oxygen-to-carbon ratios up to 1.2). The average degree of oxygenation of the organic compounds decreases while the clusters are growing. Our measurements therefore connect oxidized organics directly, and in detail, with the very first steps of new particle formation and their growth between 1 and 2 nm in a controlled environment. Thus, they confirm that oxidized organics are involved in both the formation and growth of particles under ambient conditions. PMID:24101502

  17. Molecular understanding of atmospheric particle formation from sulfuric acid and large oxidized organic molecules.

    PubMed

    Schobesberger, Siegfried; Junninen, Heikki; Bianchi, Federico; Lönn, Gustaf; Ehn, Mikael; Lehtipalo, Katrianne; Dommen, Josef; Ehrhart, Sebastian; Ortega, Ismael K; Franchin, Alessandro; Nieminen, Tuomo; Riccobono, Francesco; Hutterli, Manuel; Duplissy, Jonathan; Almeida, João; Amorim, Antonio; Breitenlechner, Martin; Downard, Andrew J; Dunne, Eimear M; Flagan, Richard C; Kajos, Maija; Keskinen, Helmi; Kirkby, Jasper; Kupc, Agnieszka; Kürten, Andreas; Kurtén, Theo; Laaksonen, Ari; Mathot, Serge; Onnela, Antti; Praplan, Arnaud P; Rondo, Linda; Santos, Filipe D; Schallhart, Simon; Schnitzhofer, Ralf; Sipilä, Mikko; Tomé, António; Tsagkogeorgas, Georgios; Vehkamäki, Hanna; Wimmer, Daniela; Baltensperger, Urs; Carslaw, Kenneth S; Curtius, Joachim; Hansel, Armin; Petäjä, Tuukka; Kulmala, Markku; Donahue, Neil M; Worsnop, Douglas R

    2013-10-22

    Atmospheric aerosols formed by nucleation of vapors affect radiative forcing and therefore climate. However, the underlying mechanisms of nucleation remain unclear, particularly the involvement of organic compounds. Here, we present high-resolution mass spectra of ion clusters observed during new particle formation experiments performed at the Cosmics Leaving Outdoor Droplets chamber at the European Organization for Nuclear Research. The experiments involved sulfuric acid vapor and different stabilizing species, including ammonia and dimethylamine, as well as oxidation products of pinanediol, a surrogate for organic vapors formed from monoterpenes. A striking resemblance is revealed between the mass spectra from the chamber experiments with oxidized organics and ambient data obtained during new particle formation events at the Hyytiälä boreal forest research station. We observe that large oxidized organic compounds, arising from the oxidation of monoterpenes, cluster directly with single sulfuric acid molecules and then form growing clusters of one to three sulfuric acid molecules plus one to four oxidized organics. Most of these organic compounds retain 10 carbon atoms, and some of them are remarkably highly oxidized (oxygen-to-carbon ratios up to 1.2). The average degree of oxygenation of the organic compounds decreases while the clusters are growing. Our measurements therefore connect oxidized organics directly, and in detail, with the very first steps of new particle formation and their growth between 1 and 2 nm in a controlled environment. Thus, they confirm that oxidized organics are involved in both the formation and growth of particles under ambient conditions. PMID:24101502

  18. Control of Listeria monocytogenes in Turkey Deli Loaves using Organic Acids as Formulation Ingredients

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The growth of Listeria monocytogenes (LM) in further processed meat products has become a major concern and an important food safety issue. The meat and poultry industries have incorporated interventions such as organic acids in marinades in order to inhibit the growth of LM. In this study, organic...

  19. PH BUFFERING IN FOREST SOIL ORGANIC HORIZONS: RELEVANCE TO ACID PRECIPITATION

    EPA Science Inventory

    Samples of organic surface horizons (Oi, Oe, Oa) from New York State forest soils were equilibrated with 0 to 20 cmol HNO3 Kg(-1) soil in the laboratory by a batch technique designed to simulate reactions of acid precipitation with forest floors. Each organic horizon retained a c...

  20. EFFECT OF ACID TREATMENT ON DISSOLVED ORGANIC CARBON RETENTION BY A SPODIC HORIZON

    EPA Science Inventory

    Processes involving the movement of organic substances in forest soils are not well understood. This study was conducted to examine the role of acidic inputs on dissolved organic carbon (DOC) mobility, processes affecting the retention of DOV by a B horizon, and SO2-4 adsorption....

  1. Acid-Base Learning Outcomes for Students in an Introductory Organic Chemistry Course

    ERIC Educational Resources Information Center

    Stoyanovich, Carlee; Gandhi, Aneri; Flynn, Alison B.

    2015-01-01

    An outcome-based approach to teaching and learning focuses on what the student demonstrably knows and can do after instruction, rather than on what the instructor teaches. This outcome-focused approach can then guide the alignment of teaching strategies, learning activities, and assessment. In organic chemistry, mastery of organic acid-base…

  2. Organic compounds in lunar samples: pyrolysis products, hydrocarbons, amino acids.

    PubMed

    Nagy, B; Drew, D M; Hamilton, P B; Modzeleski, V E; Murphy, M E; Scott, W M; Urey, H C; Young, M

    1970-01-30

    Lunar fines and a chip from inside a rock pyrolyzed in helium at 700 degrees C gave methane, other gases, and aromatic hydrocarbons. Benzene/methanol extracts of fines yielded traces of high molecular weight alkanes and sulfur. Traces of glycine, alanine, ethanolamine, and urea were found in aqueous extracts. Biological controls and a terrestrial rock, dunite, subjected to exhaust from the lunar module descent engine showed a different amino acid distribution. Interpretation of the origin of the carbon compounds requires extreme care, because of possible contamination acquired during initial sample processing. PMID:5410553

  3. Yearly trend of dicarboxylic acids in organic aerosols from south of Sweden and source attribution

    NASA Astrophysics Data System (ADS)

    Hyder, Murtaza; Genberg, Johan; Sandahl, Margareta; Swietlicki, Erik; Jönsson, Jan Åke

    2012-09-01

    Seven aliphatic dicarboxylic acids (C3-C9) along with phthalic acid, pinic acid and pinonic acid were determined in 35 aerosol (PM10) samples collected over the year at Vavihill sampling station in south of Sweden. Mixture of dichloromethane and methanol (ratio 1:3) was preferred over water for extraction of samples and extraction was assisted by ultrasonic agitation. Analytes were derivatized using N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) containing 1% trimethylsilyl chloride and analyzed using gas chromatography/mass spectrometry. Among studied analytes, azelaic acid was found maximum with an average concentration of 6.0 ± 3.6 ng m-3 and minimum concentration was found for pimelic acid (1.06 ± 0.63 ng m-3). A correlation coefficients analysis was used for defining the possible sources of analytes. Higher dicarboxylic acids (C7-C9) showed a strong correlation with each other (correlation coefficients (r) range, 0.96-0.97). Pinic and pinonic acids showed an increase in concentration during summer. Lower carbon number dicarboxylic acids (C3-C6) and phthalic acid were found strongly correlated, but showed a poor correlation with higher carbon number dicarboxylic acids (C7-C9), suggesting a different source for them. Biomass burning, vehicle exhaust, photo-oxidation of volatile organic compounds (natural and anthropogenic emissions) were possible sources for dicarboxylic acids.

  4. Six hydrogen-bonded supramolecular frameworks assembled from organic acids and p-dimethylaminobenzaldehyde

    NASA Astrophysics Data System (ADS)

    Jin, Shouwen; Wang, Lanqing; Lou, Yulei; Liu, Li; Li, Bin; Li, Linyu; Feng, Chao; Liu, Hui; Wang, Daqi

    2016-03-01

    Cocrystallization of the commonly available organic compound, p-dimethylaminobenzaldehyde, with a series of organic acids gave a total of six molecular adducts with the compositions: p-dimethylaminobenzaldehyde : (3,5-dinitrosalicylic acid) [(L) · (Hdsa), Hdsa = 3,5-dinitrosalicylic acid] (1), p-dimethylaminobenzaldehyde : (3-nitrophthalic acid) [(L) · (3-H2npa), 3-H2npa = 3-nitrophthalic acid] (2), p-dimethylaminobenzaldehyde : (4-nitrophthalic acid) [(L) · (4-H2npa), 4-H2npa = 4-nitrophthalic acid] (3), p-dimethylaminobenzaldehyde : (1,5-naphthalenedisulfonic acid) : (NH3)2 [NH4 · (HL) · (nds2-) · NH3, nds- = 1,5-naphthalenedisulfonate] (4), p-dimethylaminobenzaldehyde : (oxalic acid)0.5 [(L) · (H2oa)0.5, H2oa = oxalic acid] (5), and p-dimethylaminobenzaldehyde : (fumaric acid)0.5 [(L) · (H2fum)0.5, H2fum = fumaric acid] (6). The six molecular adducts have been characterized by X-ray diffraction technique, IR, and elemental analysis, and the melting points of all adducts were also reported. And their structural and supramolecular aspects are fully analyzed. Of the six adducts, only 4 is an organic salt and the other five are cocrystals. The crystal packing is interpreted in terms of the strong classical hydrogen bonds as well as other weak non-classical hydrogen bonds. The different families of non-covalent bonds contribute to the stabilization and expansion of the total high-dimensional (2D-3D) frameworks.

  5. Effect of organic acids found in cottonseed hull hydrolysate on the xylitol fermentation by Candida tropicalis.

    PubMed

    Wang, Le; Wu, Dapeng; Tang, Pingwah; Yuan, Qipeng

    2013-08-01

    Five organic acids (acetic, ferulic, 4-hydroxybenzoic, formic and levulinic acids) typically associated in the hemicellulose hydrolysate were selected to study their effects on the xylitol fermentation. The effects of individual and combined additions were independently evaluated on the following parameters: inhibitory concentration; initial cell concentration; pH value; and membrane integrity. The results showed that the toxicities of organic acids were related to their hydrophobility and significantly affected by the fermentative pH value. In addition, it was revealed that the paired combinations of organic acids did not impose synergetic inhibition. Moreover, it was found that the fermentation inhibition could be alleviated with the simple manipulations by increasing the initial cell concentration, raising the initial pH value and minimizing furfural levels by evaporation during the concentration of hydrolysates. The proposed strategies for minimizing the negative effects could be adopted to improve the xylitol fermentation in the industrial applications. PMID:23138642

  6. In vitro susceptibility of Brachyspira hyodysenteriae to organic acids and essential oil components

    PubMed Central

    VANDE MAELE, Lien; HEYNDRICKX, Marc; MAES, Dominiek; DE PAUW, Nele; MAHU, Maxime; VERLINDEN, Marc; HAESEBROUCK, Freddy; MARTEL, An; PASMANS, Frank; BOYEN, Filip

    2015-01-01

    The antibacterial potential of organic acids and essential oil components against Brachyspira hyodysenteriae, the causative pathogen of swine dysentery, was evaluated. Minimum inhibitory concentrations (MIC) of 15 compounds were determined at pH 7.2 and pH 6.0, using a broth microdilution assay. In addition, possible synergism was determined. MIC values for the three tested strains were similar. For organic acids, MIC values at pH 6.0 were lower than at pH 7.2. B. hyodysenteriae was most sensitive to cinnamaldehyde and lauric acid, with MIC values <1.5 mM. Most antibacterial effects of binary combinations were additive, however, for thymol and carvacrol, synergism could be observed. In vitro results demonstrate the antibacterial action of certain essential oil components and organic acids against B. hyodysenteriae. PMID:26369432

  7. Five organic salts assembled from carboxylic acids and bis-imidazole derivatives through collective noncovalent interactions

    NASA Astrophysics Data System (ADS)

    Jin, Shouwen; Guo, Jianzhong; Liu, Li; Wang, Daqi

    2011-10-01

    Five multicomponent crystals of bis(imidazole) derivatives have been prepared with 5-nitrosalicylic acid, 5-sulfosalicylic acid, and phthalic acid. The five crystalline forms reported are organic salts of which the crystal structures have all been determined by X-ray diffraction. The results presented herein indicate that the strength and directionality of the N sbnd H⋯O, O sbnd H⋯O, and N sbnd H⋯N hydrogen bonds (ionic or neutral) between carboxylic acids and ditopic imidazoles are sufficient to bring about the formation of binary organic salts. All supramolecular architectures of the organic salts 1- 5 involve extensive O sbnd H⋯O, and N sbnd H⋯O hydrogen bonds as well as other noncovalent interactions. The role of weak and strong noncovalent interactions in the crystal packing is ascertained. These noncovalent interactions combined, all the complexes displayed 3D framework structure.

  8. In vitro susceptibility of Brachyspira hyodysenteriae to organic acids and essential oil components.

    PubMed

    Vande Maele, Lien; Heyndrickx, Marc; Maes, Dominiek; De Pauw, Nele; Mahu, Maxime; Verlinden, Marc; Haesebrouck, Freddy; Martel, An; Pasmans, Frank; Boyen, Filip

    2016-02-01

    The antibacterial potential of organic acids and essential oil components against Brachyspira hyodysenteriae, the causative pathogen of swine dysentery, was evaluated. Minimum inhibitory concentrations (MIC) of 15 compounds were determined at pH 7.2 and pH 6.0, using a broth microdilution assay. In addition, possible synergism was determined. MIC values for the three tested strains were similar. For organic acids, MIC values at pH 6.0 were lower than at pH 7.2. B. hyodysenteriae was most sensitive to cinnamaldehyde and lauric acid, with MIC values <1.5 mM. Most antibacterial effects of binary combinations were additive, however, for thymol and carvacrol, synergism could be observed. In vitro results demonstrate the antibacterial action of certain essential oil components and organic acids against B. hyodysenteriae. PMID:26369432

  9. Direct enzyme assay evidence confirms aldehyde reductase function of Ydr541cp and Ygl039wp from Saccharomyces cerevisiae.

    PubMed

    Moon, Jaewoong; Liu, Z Lewis

    2015-04-01

    The aldehyde reductase gene ARI1 is a recently characterized member of an intermediate subfamily within the short-chain dehydrogenase/reductase (SDR) superfamily that clarified mechanisms of in situ detoxification of 2-furaldehyde and 5-hydroxymethyl-2-furaldehyde by Saccharomyces cerevisiae. Uncharacterized open reading frames (ORFs) are common among tolerant candidate genes identified for lignocellulose-to-advanced biofuels conversion. This study presents partially purified proteins of two ORFs, YDR541C and YGL039W, and direct enzyme assay evidence against aldehyde-inhibitory compounds commonly encountered during lignocellulosic biomass fermentation processes. Each of the partially purified proteins encoded by these ORFs showed a molecular mass of approximately 38 kDa, similar to Ari1p, a protein encoded by aldehyde reductase gene. Both proteins demonstrated strong aldehyde reduction activities toward 14 aldehyde substrates, with high levels of reduction activity for Ydr541cp toward both aromatic and aliphatic aldehydes. While Ydr541cp was observed to have a significantly higher specific enzyme activity at 20 U/mg using co-factor NADPH, Ygl039wp displayed a NADH preference at 25 U/mg in reduction of butylaldehyde. Amino acid sequence analysis identified a characteristic catalytic triad, Ser, Tyr and Lys; a conserved catalytic motif of Tyr-X-X-X-Lys; and a cofactor-binding sequence motif, Gly-X-X-Gly-X-X-Ala, near the N-terminus that are shared by Ydr541cp, Ygl039wp, Yol151wp/GRE2 and Ari1p. Findings of aldehyde reductase genes contribute to the yeast gene annotation and aids development of the next-generation biocatalyst for advanced biofuels production. PMID:25656103

  10. Identification of long chain specific aldehyde reductase and its use in enhanced fatty alcohol production in E. coli.

    PubMed

    Fatma, Zia; Jawed, Kamran; Mattam, Anu Jose; Yazdani, Syed Shams

    2016-09-01

    Long chain fatty alcohols have wide application in chemical industries and transportation sector. There is no direct natural reservoir for long chain fatty alcohol production, thus many groups explored metabolic engineering approaches for its microbial production. Escherichia coli has been the major microbial platform for this effort, however, terminal endogenous enzyme responsible for converting fatty aldehydes of chain length C14-C18 to corresponding fatty alcohols is still been elusive. Through our in silico analysis we selected 35 endogenous enzymes of E. coli having potential of converting long chain fatty aldehydes to fatty alcohols and studied their role under in vivo condition. We found that deletion of ybbO gene, which encodes NADP(+) dependent aldehyde reductase, led to >90% reduction in long chain fatty alcohol production. This feature was found to be strain transcending and reinstalling ybbO gene via plasmid retained the ability of mutant to produce long chain fatty alcohols. Enzyme kinetic study revealed that YbbO has wide substrate specificity ranging from C6 to C18 aldehyde, with maximum affinity and efficiency for C18 and C16 chain length aldehyde, respectively. Along with endogenous production of fatty aldehyde via optimized heterologous expression of cyanobaterial acyl-ACP reductase (AAR), YbbO overexpression resulted in 169mg/L of long chain fatty alcohols. Further engineering involving modulation of fatty acid as well as of phospholipid biosynthesis pathway improved fatty alcohol production by 60%. Finally, the engineered strain produced 1989mg/L of long chain fatty alcohol in bioreactor under fed-batch cultivation condition. Our study shows for the first time a predominant role of a single enzyme in production of long chain fatty alcohols from fatty aldehydes as well as of modulation of phospholipid pathway in increasing the fatty alcohol production. PMID:27134112

  11. Amphiphilic calixresorcinarene associates as effective solubilizing agents for hydrophobic organic acids: construction of nano-aggregates.

    PubMed

    Morozova, Ju E; Syakaev, V V; Kazakova, E Kh; Shalaeva, Ya V; Nizameev, I R; Kadirov, M K; Voloshina, A D; Zobov, V V; Konovalov, A I

    2016-07-01

    Here we represent the first example of the formation of mixed nanoscale associates, constructed from amphiphilic calixresorcinarenes and hydrophobic carboxylic acids including drugs. The amidoamino-calixresorcinarene self-associates effectively solubilize hydrophobic carboxylic acids - drugs such as naproxen, ibuprofen, ursodeoxycholic acid and aliphatic dodecanoic acid - with the formation of the mixed aggregates with the macrocycle/substrate stoichiometry from 1/1 to 1/7. The ionization of organic acids and the peripheral nitrogen atoms of the macrocycles with the subsequent inclusion of hydrophobic acids into the macrocycle self-associates is the driving force of solubilization. In some cases, this leads to the co-assembly of the macrocycle polydisperse associates into supramolecular monodisperse nanoparticles with the diameter of about 100 nm. The efficiency of drug loading into the nanoparticles is up to 45% and depends on the structure of organic acid. The dissociation of the mixed aggregates and release of organic acid are attained by decreasing pH. PMID:27252123

  12. Microbial production of specialty organic acids from renewable and waste materials.

    PubMed

    Alonso, Saúl; Rendueles, Manuel; Díaz, Mario

    2015-01-01

    Microbial production of organic acids has become a fast-moving field due to the increasing role of these compounds as platform chemicals. In recent years, the portfolio of specialty fermentation-derived carboxylic acids has increased considerably, including the production of glyceric, glucaric, succinic, butyric, xylonic, fumaric, malic, itaconic, lactobionic, propionic and adipic acid through innovative fermentation strategies. This review summarizes recent trends in the use of novel microbial platforms as well as renewable and waste materials for efficient and cost-effective bio-based production of emerging high-value organic acids. Advances in the development of robust and efficient microbial bioprocesses for producing carboxylic acids from low-cost feedstocks are also discussed. The industrial market scenario is also reviewed, including the latest information on the stage of development for producing these emerging bio-products via large-scale fermentation. PMID:24754448

  13. n-Aldehydes (C6-C10) in snow samples collected at the high alpine research station Jungfraujoch during CLACE 5

    NASA Astrophysics Data System (ADS)

    Sieg, K.; Starokozhev, E.; Fries, E.; Sala, S.; Püttmann, W.

    2009-04-01

    pattern found in snow collected at Jungfraujoch. One exception is the significantly higher proportion of n-hexanal in the Jungfraujoch samples compared to vegetation emission. Additionally, indirect biogenic emissions can contribute to the atmospheric concentrations of n-aldehydes through oxidation of precursor compounds of biogenic origin. In this context, Moise and Rudich [4] and Thornberry and Abbatt [5] proposed the preferential formation of n-nonanal and n-hexanal from the cleavage by ozonolysis of double bonds in unsaturated fatty acids (namely oleic acid and linoleic acids). The predominance of n-hexanal and n-nonanal among the C6-C10 n-aldehydes in the snow samples collected at Jungfraujoch during CLACE 5 is therefore an argument for the formation of the aldehydes through oxidation of unsaturated fatty acids in the atmosphere. Anthropogenic emissions of n-aldehydes i.e. from fossil fuel burning are thought to be negligible in the air masses reaching Jungfraujoch. References: [1] P. Ciccioli, E. Brancaleoni, M. Frattoni, A. Cecinato, A. Brachetti, Atmos. Environ., Part A 27 (1993) 1891. [2] Y. Yokouchi, H. Mukai, K. Nakajima, Y. Ambe, Atmos. Environ., Part A 24 (1990) 439. [3] J. Kesselmeier, M. Staudt, J. Atmos. Chem. 33 (1999) 23. [4] T. Moise, Y. Rudich, J. Phys. Chem. 106 (2002) 6469. [5] T. Thornberry, J.P.D. Abbatt, Phys. Chem. Chem. Phys. 6 (2004) 84.

  14. Alteration of organic matter during infaunal polychaete gut passage and links to sediment organic geochemistry. Part I: Amino acids

    NASA Astrophysics Data System (ADS)

    Woulds, Clare; Middelburg, Jack J.; Cowie, Greg L.

    2012-01-01

    Of the factors which control the quantity and composition of organic matter (OM) buried in marine sediments, the links between infaunal ingestion and gut passage and sediment geochemistry have received relatively little attention. This study aimed to use feeding experiments and novel isotope tracing techniques to quantify amino acid net accumulation and loss during polychaete gut passage, and to link this to patterns of selective preservation and decay in sediments. Microcosms containing either Arenicolamarina or Hediste (formerly Nereis) diversicolor were constructed from defaunated sediment and filtered estuarine water, and maintained under natural temperature and light conditions. They were fed with 13C-labelled diatoms daily for 8 days, and animals were transferred into fresh, un-labelled sediment after ∼20 days. Samples of fauna, microcosm sediment and faecal matter were collected after 8, ∼20 and ∼40 days, and analysed for their bulk isotopic signatures and 13C-labelled amino acid compositions. Bulk isotopic data showed that, consistent with their feeding modes, Hediste assimilated added 13C more quickly, and attained a higher labelling level than Arenicola. Both species retained the added 13C in their biomass even after removal from the food. A principal component analysis of 13C-labelled amino acid mole percentages showed clear differences in composition between the algae, faunal tissues, and sediment plus faecal matter. Further, the two species of polychaete showed different compositions in their tissues. The amino acids phenylalanine, valine, leucine, iso-leucine, threonine and proline showed net accumulation in polychaete tissues. Serine, methionine, lysine, aspartic and glutamic acids and tyrosine were rapidly lost through metabolism, consistent with their presence in easily digestible cell components (as opposed to cell walls which offer physical protection). All sample types (polychaete tissues, sediments and faecal matter) were enriched in

  15. Protocatechuic Acid Levels Discriminate Between Organic and Conventional Wheat from Denmark.

    PubMed

    Weesepoel, Yannick; Heenan, Samuel; Boerrigter-Eenling, Rita; Venderink, Tjerk; Blokland, Marco; van Ruth, Saskia

    2016-01-01

    Organic wheat retails at higher market prices than the conventionally grown counterparts. In view of fair competition and sustainable consumer confidence, the organic nature of organic wheat needs to be assured. Amongst other controls this requires analytical tests based on discriminating traits. In this paper, phenolic acids were examined by liquid chromatography analysis as biomarkers for discriminating between the two groups by means of a controlled grown full factorial design Danish wheat sample set. By combining baseline and retention-time correction pre-treatments and principal component analysis, discrimination between organic and conventional produce was found to be expressed in the first principal component (93%), whilst the second principal component accounted for the production year (4%). Upon examination of the loadings plot, a single chromatographic peak was found to account for a large part in the discrimination between the two wheat production systems. This was further underpinned by statistically significant differences found in concentrations between the organic and conventional production systems of this phenolic acid (ANOVA, P<0.05). The phenolic acid was tentatively identified as protocatechuic acid by negative mode mass spectrometry. The results obtained implied that protocatechuic acid may serve as a single marker for discrimination between organic and conventional produced wheat. PMID:27198816

  16. Organic Compounds in Carbonaceous Meteorites

    NASA Technical Reports Server (NTRS)

    Cooper, Grorge

    2001-01-01

    Carbonaceous meteorites are relatively enriched in soluble organic compounds. To date, these compounds provide the only record available to study a range of organic chemical processes in the early Solar System chemistry. The Murchison meteorite is the best-characterized carbonaceous meteorite with respect to organic chemistry. The study of its organic compounds has related principally to aqueous meteorite parent body chemistry and compounds of potential importance for the origin of life. Among the classes of organic compounds found in Murchison are amino acids, amides, carboxylic acids, hydroxy acids, sulfonic acids, phosphonic acids, purines and pyrimidines (Table 1). Compounds such as these were quite likely delivered to the early Earth in asteroids and comets. Until now, polyhydroxylated compounds (polyols), including sugars (polyhydroxy aldehydes or ketones), sugar alcohols, sugar acids, etc., had not been identified in Murchison. Ribose and deoxyribose, five-carbon sugars, are central to the role of contemporary nucleic acids, DNA and RNA. Glycerol, a three-carbon sugar alcohol, is a constituent of all known biological membranes. Due to the relative lability of sugars, some researchers have questioned the lifetime of sugars under the presumed conditions on the early Earth and postulated other (more stable) compounds as constituents of the first replicating molecules. The identification of potential sources and/or formation mechanisms of pre-biotic polyols would add to the understanding of what organic compounds were available, and for what length of time, on the ancient Earth.

  17. A note on the prebiotic synthesis of organic acids in carbonaceous meteorites

    NASA Technical Reports Server (NTRS)

    Kerridge, John F.

    1991-01-01

    Strong similarities between monocarboxylic and hydrocarboxylic acids in the Murchison meteorite suggest corresponding similarities in their origins. However, various lines of evidence apparently implicate quite different precursor compounds in the synthesis of the different acids. These seeming inconsistencies can be resolved by postulating that the apparent precursors also share a related origin. Pervasive D enrichment indicates that this origin was in a presolar molecular cloud. The organic acids themselves were probably synthesized in an aqueous environment on an asteroidal parent body, the hydroxy (and amino) acids by means of the Strecker cyanohydrin reaction.

  18. Bifunctional Organic Polymeric Catalysts with a Tunable Acid-Base Distance and Framework Flexibility

    NASA Astrophysics Data System (ADS)

    Chen, Huanhui; Wang, Yanan; Wang, Qunlong; Li, Junhui; Yang, Shiqi; Zhu, Zhirong

    2014-09-01

    Acid-base bifunctional organic polymeric catalysts were synthesized with tunable structures. we demonstrated two synthesis approaches for structural fine-tune. In the first case, the framework flexibility was tuned by changing the ratio of rigid blocks to flexible blocks within the polymer framework. In the second case, we precisely adjusted the acid-base distance by distributing basic monomers to be adjacent to acidic monomers, and by changing the chain length of acidic monomers. In a standard test reaction for the aldol condensation of 4-nitrobenzaldehyde with acetone, the catalysts showed good reusability upon recycling and maintained relatively high conversion percentage.

  19. Uric Acid Spherulites in the Reflector Layer of Firefly Light Organ

    PubMed Central

    Goh, King-Siang; Sheu, Hwo-Shuenn; Hua, Tzu-En; Kang, Mei-Hua; Li, Chia-Wei

    2013-01-01

    Background In firefly light organs, reflector layer is a specialized tissue which is believed to play a key role for increasing the bioluminescence intensity through reflection. However, the nature of this unique tissue remains elusive. In this report, we investigated the role, fine structure and nature of the reflector layer in the light organ of adult Luciola cerata. Principal Findings Our results indicated that the reflector layer is capable of reflecting bioluminescence, and contains abundant uric acid. Electron microscopy (EM) demonstrated that the cytosol of the reflector layer's cells is filled with densely packed spherical granules, which should be the uric acid granules. These granules are highly regular in size (∼700 nm in diameter), and exhibit a radial internal structure. X-ray diffraction (XRD) analyses revealed that an intense single peak pattern with a d-spacing value of 0.320 nm is specifically detected in the light organ, and is highly similar to the diffraction peak pattern and d-spacing value of needle-formed crystals of monosodium urate monohydrate. However, the molar ratio evaluation of uric acid to various cations (K+, Na+, Ca2+ and Mg2+) in the light organ deduced that only a few uric acid molecules were in the form of urate salts. Thus, non-salt uric acid should be the source of the diffraction signal detected in the light organ. Conclusions In the light organ, the intense single peak diffraction signal might come from a unique needle-like uric acid form, which is different from other known structures of non-salt uric acid form. The finding of a radial structure in the granules of reflector layer implies that the spherical uric acid granules might be formed by the radial arrangement of needle-formed packing matter. PMID:23441187

  20. The effects of different thermal treatments and organic acid levels on nutrient digestibility in broilers.

    PubMed

    Goodarzi Boroojeni, F; Mader, A; Knorr, F; Ruhnke, I; Röhe, I; Hafeez, A; Männer, K; Zentek, J

    2014-05-01

    Poultry feed is a potential vector for pathogens. Heat processing and organic acid treatments may decontaminate feed and can affect bird performance as well as feed digestibility. The present study was performed to investigate the effect of different thermal treatments including pelleting (P), long-term conditioning at 85°C for 3 min (L), or expanding at 110°C (E110) and 130°C for 3 to 5 s (E130) without or with 0.75 and 1.5% organic acid supplementation (63.75% formic acid, 25.00% propionic acid, and 11.25% water) on performance, nutrient digestibility, and organ weights of broilers. In total, 960 one-day-old broiler chicks were randomly assigned to 8 replicates using a 3 × 4 factorial arrangement. Performance variables were determined, and the relative organ weights and ileal and total amino acid (AA) digestibilities were measured at d 35. The organic acid inclusion linearly improved feed efficiency in the first week (P ≤ 0.05). The acid inclusion levels and thermal treatments had no significant effect on the performance variables at later intervals of the growing period of the birds. The L group showed the lowest ileal AA and CP digestibility. The inclusion of organic acids had a quadratic effect on total and ileal digestibility of isoleucine (P ≤ 0.05), whereas it had no significant effect on the ileal digestibility of other AA and nutrients. The relative weights of the jejunum and small intestine were significantly higher in the E130 group compared with P and L (P ≤ 0.05). In conclusion, our study demonstrated that long-term heat conditioning can decrease ileal nutrient digestibility, whereas pelleting and expansion, independently of organic acid addition, seemed to have no negative impact on broiler performance and nutrient digestibilities. Moreover, adding a blend of organic acids to broiler diets had neither positive nor negative effects on nutrient digestibility and final broiler performance. This indicates the feasibility of short-term thermal

  1. Role of Organic Acids in Bioformation of Kaolinite: Results of Laboratory Experiments

    NASA Astrophysics Data System (ADS)

    Bontognali, T. R. R.; Vasconcelos, C.; McKenzie, J. A.

    2012-04-01

    Clay minerals and other solid silica phases have a broad distribution in the geological record and greatly affect fundamental physicochemical properties of sedimentary rocks, including porosity. An increasing number of studies suggests that microbial activity and microbially produced organic acids might play an important role in authigenic clay mineral formation, at low temperatures and under neutral pH conditions. In particular, early laboratory experiments (Linares and Huertas, 1971) reported the precipitation of kaolinite in solutions of SiO2 and Al2O3 with different molar ratios SiO2/Al2O3, together with fulvic acid (a non-characterized mixture of many different acids containing carboxyl and phenolate groups) that was extracted from peat soil. Despite many attempts, these experiments could not be reproduced until recently. Fiore et al. (2011) hypothesized that the non-sterile fulvic acid might have contained microbes that participated in the formation of kaolinite. Using solutions saturated with Si and Al and containing oxalate and/or mixed microbial culture extracted from peat-moss soil, they performed incubation experiments, which produced kaolinite exclusively in solutions containing oxalate and microbes. We proposed to test the role of specific organic acids for kaolinite formation, conducting laboratory experiments at 25˚C, with solutions of sodium silicate, aluminum chloride and various organic compounds (i.e. EDTA, citric acid, succinic acid and oxalic acid). Specific organic acids may stabilize aluminum in octahedral coordination positions, which is crucial for the initial nucleation step. In our experiments, a poorly crystalline mineral that is possibly a kaolinite precursor formed exclusively in the presence of succinic acid. In experiments with other organic compounds, no incorporation of Al was observed, and amorphous silica was the only precipitated phase. In natural environments, succinic acid is produced by a large variety of microbes as an

  2. Expanding the modular ester fermentative pathways for combinatorial biosynthesis of esters from volatile organic acids.

    PubMed

    Layton, Donovan S; Trinh, Cong T

    2016-08-01

    Volatile organic acids are byproducts of fermentative metabolism, for example, anaerobic digestion of lignocellulosic biomass or organic wastes, and are often times undesired inhibiting cell growth and reducing directed formation of the desired products. Here, we devised a general framework for upgrading these volatile organic acids to high-value esters that can be used as flavors, fragrances, solvents, and biofuels. This framework employs the acid-to-ester modules, consisting of an AAT (alcohol acyltransferase) plus ACT (acyl CoA transferase) submodule and an alcohol submodule, for co-fermentation of sugars and organic acids to acyl CoAs and alcohols to form a combinatorial library of esters. By assembling these modules with the engineered Escherichia coli modular chassis cell, we developed microbial manufacturing platforms to perform the following functions: (i) rapid in vivo screening of novel AATs for their catalytic activities; (ii) expanding combinatorial biosynthesis of unique fermentative esters; and (iii) upgrading volatile organic acids to esters using single or mixed cell cultures. To demonstrate this framework, we screened for a set of five unique and divergent AATs from multiple species, and were able to determine their novel activities as well as produce a library of 12 out of the 13 expected esters from co-fermentation of sugars and (C2-C6) volatile organic acids. We envision the developed framework to be valuable for in vivo characterization of a repertoire of not-well-characterized natural AATs, expanding the combinatorial biosynthesis of fermentative esters, and upgrading volatile organic acids to high-value esters. Biotechnol. Bioeng. 2016;113: 1764-1776. © 2016 Wiley Periodicals, Inc. PMID:26853081

  3. Transport and cycling of iron and hydrogen peroxide in a freshwater stream: Influence of organic acids

    USGS Publications Warehouse

    Scott, D.T.; Runkel, R.L.; McKnight, Diane M.; Voelker, B.M.; Kimball, B.A.; Carraway, E.R.

    2003-01-01

    An in-stream injection of two dissolved organic acids (phthalic and aspartic acids) was performed in an acidic mountain stream to assess the effects of organic acids on Fe photoreduction and H2O2 cycling. Results indicate that the fate of Fe is dependent on a net balance of oxidative and reductive processes, which can vary over a distance of several meters due to changes in incident light and other factors. Solution phase photoreduction rates were high in sunlit reaches and were enhanced by the organic acid addition but were also limited by the amount of ferric iron present in the water column. Fe oxide photoreduction from the streambed and colloids within the water column resulted in an increase in the diurnal load of total filterable Fe within the experimental reach, which also responded to increases in light and organic acids. Our results also suggest that Fe(II) oxidation increased in response to the organic acids, with the result of offsetting the increase in Fe(II) from photoreductive processes. Fe(II) was rapidly oxidized to Fe(III) after sunset and during the day within a well-shaded reach, presumably through microbial oxidation. H2O 2, a product of dissolved organic matter photolysis, increased downstream to maximum concentrations of 0.25 ??M midday. Kinetic calculations show that the buildup of H2O2 is controlled by reaction with Fe(III), but this has only a small effect on Fe(II) because of the small formation rates of H2O2 compared to those of Fe(II). The results demonstrate the importance of incorporating the effects of light and dissolved organic carbon into Fe reactive transport models to further our understanding of the fate of Fe in streams and lakes.

  4. DEVELOPMENTAL EXPRESSION OF ALDEHYDE DEHYDROGENASE IN RAT: A COMPARISON OF LIVER AND LUNG DEVELOPMENT

    EPA Science Inventory

    Metabolism is one of the major determinants for age-related susceptibility changes to chemicals. Aldehydes are highly reactive molecules present in the environment and can be produced during biotransformation of xenobiotics. Aldehyde dehydrogenases (ALDH) are important in aldehyd...

  5. Cationic RAFT polymerization using ppm concentrations of organic acid.

    PubMed

    Uchiyama, Mineto; Satoh, Kotaro; Kamigaito, Masami

    2015-02-01

    A metal-free, cationic, reversible addition-fragmentation chain-transfer (RAFT) polymerization was proposed and realized. A series of thiocarbonylthio compounds were used in the presence of a small amount of triflic acid for isobutyl vinyl ether to give polymers with controlled molecular weight of up to 1×10(5) and narrow molecular-weight distributions (Mw /Mn <1.1). This "living" or controlled cationic polymerization is applicable to various electron-rich monomers including vinyl ethers, p-methoxystyrene, and even p-hydroxystyrene that possesses an unprotected phenol group. A transformation from cationic to radical RAFT polymerization enables the synthesis of block copolymers between cationically and radically polymerizable monomers, such as vinyl ether and vinyl acetate or methyl acrylate. PMID:25511364

  6. Modulation of sialic acid levels among some organs during insulin resistance or hyperglycemic states.

    PubMed

    Ibrahim, Mohammed Auwal; Abdulkadir, Aisha; Onojah, Alice; Sani, Lawal; Adamu, Auwal; Abdullahi, Hadiza

    2016-01-01

    Previous studies have suggested a possible connection between insulin resistance and chronic hyperglycemia with membrane sialic acid content. In this study, the effects of high (20% ad libitum) fructose and glucose feeding on the sialic acid levels of some organs were investigated in rats. The blood glucose levels of the high fructose- and glucose-fed rats were consistently and significantly (P < 0.05) higher than the normal control throughout the experiment. Free serum sialic acid and total hepatic sialic acid levels were elevated in the high fructose- and glucose-fed rats compared to normal control, but only the data for the high glucose-fed group were significantly (P < 0.05) different from the normal control. Conversely, a significant (P < 0.05) decrease in the pancreatic sialic acid level was observed in high glucose-fed group compared to normal control. Also, the high fructose-fed rats had lower, but insignificant (P > 0.05), pancreatic sialic acid level than the normal control. On the other hand, high fructose and glucose feeding did not significantly (P > 0.05) affect the sialic acid levels of the skeletal muscle and heart, though a tendency to increase the sialic acid level was evident in the heart. In the kidney, the sialic acid level was significantly (P < 0.05) increased in both high fructose- and glucose-fed groups. It was concluded that the liver and kidney tend to stimulate sialic acid synthesis, while the pancreas downregulate sialic acids synthesis and/or promote sialic acid release from glycoconjugates. Also, these organs may contribute to high-serum sialic acid level observed during diabetes. PMID:26468092

  7. Spatially-Interactive Biomolecular Networks Organized by Nucleic Acid Nanostructures

    PubMed Central

    Fu, Jinglin; Liu, Minghui; Liu, Yan; Yan, Hao

    2013-01-01

    Conspectus Living systems have evolved a variety of nanostructures to control the molecular interactions that mediate many functions including the recognition of targets by receptors, the binding of enzymes to substrates, and the regulation of enzymatic activity. Mimicking these structures outside of the cell requires methods that offer nanoscale control over the organization of individual network components. Advances in DNA nanotechnology have enabled the design and fabrication of sophisticated one-, two- and three-dimensional (1D, 2D and 3D) nanostructures that utilize spontaneous and sequence specific DNA hybridization. Compared to other self-assembling biopolymers, DNA nanostructures offer predictable and programmable interactions, and surface features to which other nanoparticles and bio-molecules can be precisely positioned. The ability to control the spatial arrangement of the components while constructing highly-organized networks will lead to various applications of these systems. For example, DNA nanoarrays with surface displays of molecular probes can sense noncovalent hybridization interactions with DNA, RNA, and proteins and covalent chemical reactions. DNA nanostructures can also align external molecules into well-defined arrays, which may improve the resolution of many structural determination methods, such as X-ray diffraction, cryo-EM, NMR, and super-resolution fluorescence. Moreover, by constraining target entities to specific conformations, self-assembled DNA nanostructures can serve as molecular rulers to evaluate conformation-dependent activities. This Account describes the most recent advances in the DNA nanostructure directed assembly of biomolecular networks and explores the possibility of applying this technology to other fields of study. Recently, several reports have demonstrated the DNA nanostructure directed assembly of spatially-interactive biomolecular networks. For example, researchers have constructed synthetic multi-enzyme cascades

  8. Role and structural characterization of plant aldehyde dehydrogenases from family 2 and family 7.

    PubMed

    Končitíková, Radka; Vigouroux, Armelle; Kopečná, Martina; Andree, Tomáš; Bartoš, Jan; Šebela, Marek; Moréra, Solange; Kopečný, David

    2015-05-15

    Aldehyde dehydrogenases (ALDHs) are responsible for oxidation of biogenic aldehyde intermediates as well as for cell detoxification of aldehydes generated during lipid peroxidation. So far, 13 ALDH families have been described in plants. In the present study, we provide a detailed biochemical characterization of plant ALDH2 and ALDH7 families by analysing maize and pea ALDH7 (ZmALDH7 and PsALDH7) and four maize cytosolic ALDH(cALDH)2 isoforms RF2C, RF2D, RF2E and RF2F [the first maize ALDH2 was discovered as a fertility restorer (RF2A)]. We report the crystal structures of ZmALDH7, RF2C and RF2F at high resolution. The ZmALDH7 structure shows that the three conserved residues Glu(120), Arg(300) and Thr(302) in the ALDH7 family are located in the substrate-binding site and are specific to this family. Our kinetic analysis demonstrates that α-aminoadipic semialdehyde, a lysine catabolism intermediate, is the preferred substrate for plant ALDH7. In contrast, aromatic aldehydes including benzaldehyde, anisaldehyde, cinnamaldehyde, coniferaldehyde and sinapaldehyde are the best substrates for cALDH2. In line with these results, the crystal structures of RF2C and RF2F reveal that their substrate-binding sites are similar and are formed by an aromatic cluster mainly composed of phenylalanine residues and several nonpolar residues. Gene expression studies indicate that the RF2C gene, which is strongly expressed in all organs, appears essential, suggesting that the crucial role of the enzyme would certainly be linked to the cell wall formation using aldehydes from phenylpropanoid pathway as substrates. Finally, plant ALDH7 may significantly contribute to osmoprotection because it oxidizes several aminoaldehydes leading to products known as osmolytes. PMID:25734422

  9. The effect of several organic acids on phytate phosphorus hydrolysis in broiler chicks.

    PubMed

    Liem, A; Pesti, G M; Edwards, H M

    2008-04-01

    Supplementation of some organic acids to a P-deficient diet has been shown to improve phytate P utilization. Two experiments were conducted from 0 to 16 d in battery brooders to determine the effect of various organic acids supplementation on phytate P utilization. In both experiments, birds were fed P-deficient corn and soybean meal-based diets. In experiment 1, citric acid, malic acid, fumaric acid, and EDTA were supplemented. Experiment 2 had a 2 x 2 factorial design with 2 sources of Met, 2-hydroxy-4-(methylthio) butanoic acid (HMB) and dl-Met, with or without 500 U/kg of phytase. In experiment 1, the addition of citric, malic, and fumaric acids increased percentage of bone ash, but only the effect of citric acid was significant. The addition of citric and malic acids also significantly increased the retention of P and phytate P (P<0.05). In experiment 2, the addition of phytase to the diet significantly increased 16-d BW gain, feed intake, percentage of bone ash, milligrams of bone ash, phytate P disappearance, and decreased the incidence of P-deficiency rickets. Methionine source did not affect 16-d BW gain, feed intake, feed efficiency, milligrams of bone ash, or P rickets incidence. However, the birds fed HMB had a higher percentage of bone ash and phytate P disappearance compared with the groups fed dl-Met only when phytase was added to the diets. The additions of citric acid and HMB improved phytate P utilization. However, the reason why some organic acids are effective whereas others are not is not apparent. PMID:18339989

  10. Broiler skin color as affected by organic acids: influence of concentration and method of application.

    PubMed

    Bilgili, S F; Conner, D E; Pinion, J L; Tamblyn, K C

    1998-05-01

    Color of broiler skin was evaluated after exposure to organic acids under various concentrations and simulated potential plant application conditions. Breast skin from chilled broiler carcasses was treated with acetic (AA), citric (CA), lactic (LA), malic (ML), mandelic (MN), propionic (PA), or tartaric (TA) acids at 0.5, 1, 2, 4, and 6% concentrations. Each acid and concentration was applied in simulated dip (23 C for 15 s), scalder (50 C for 2 min), and immersion chiller (1 C for 60 min) conditions. A tap water control was included with each application method. Objective color values of L* (lightness), a* (redness), and b* (yellowness) were measured before and after the treatments to calculate color differentials under a factorial arrangement of organic acids and concentrations. Skin lightness increased (P < 0.01) in simulated chiller as compared to dip and scalder applications. Skin redness was reduced significantly in scalder, and yellowness in dip and scalder applications, respectively. In simulated dip application, with the exception of PA, all acids decreased lightness and increased redness and yellowness values. Propionic acid had little affect on lightness and redness values, but decreased yellowness values. In simulated scalder application, with the exception of PA, all acids decreased lightness with increasing concentration. The redness values changed little in scalder application. However, yellowness values were increased with all acids, except for PA, which decreased yellowness values. In simulated chiller conditions, all acids, except for PA, decreased lightness and redness and increased yellowness values. Propionic acid increased lightness and decreased yellowness values significantly in chiller conditions. Alterations in skin color should be taken into account in the selection and application of organic acids as carcass disinfectants. PMID:9603365

  11. Aqueous DMSO Mediated Conversion of (2-(Arylsulfonyl)vinyl)iodonium Salts to Aldehydes and Vinyl Chlorides.

    PubMed

    Zawia, Eman; Moran, Wesley J

    2016-01-01

    Vinyl(aryl)iodonium salts are useful compounds in organic synthesis but they are under-utilized and their chemistry is under-developed. Herein is described the solvolysis of some vinyl(phenyl)iodonium salts, bearing an arylsulfonyl group, in aqueous DMSO leading to aldehyde formation. This unusual process is selective and operates under ambient conditions. Furthermore, the addition of aqueous HCl and DMSO to these vinyl(aryl)iodonium salts allows their facile conversion to vinyl chlorides. PMID:27537866

  12. Structural shifts of aldehyde dehydrogenase enzymes were instrumental for the early evolution of retinoid-dependent axial patterning in metazoans.

    PubMed

    Sobreira, Tiago J P; Marlétaz, Ferdinand; Simões-Costa, Marcos; Schechtman, Deborah; Pereira, Alexandre C; Brunet, Frédéric; Sweeney, Sarah; Pani, Ariel; Aronowicz, Jochanan; Lowe, Christopher J; Davidson, Bradley; Laudet, Vincent; Bronner, Marianne; de Oliveira, Paulo S L; Schubert, Michael; Xavier-Neto, José

    2011-01-01

    Aldehyde dehydrogenases (ALDHs) catabolize toxic aldehydes and process the vitamin A-derived retinaldehyde into retinoic acid (RA), a small diffusible molecule and a pivotal chordate morphogen. In this study, we combine phylogenetic, structural, genomic, and developmental gene expression analyses to examine the evolutionary origins of ALDH substrate preference. Structural modeling reveals that processing of small aldehydes, such as acetaldehyde, by ALDH2, versus large aldehydes, including retinaldehyde, by ALDH1A is associated with small versus large substrate entry channels (SECs), respectively. Moreover, we show that metazoan ALDH1s and ALDH2s are members of a single ALDH1/2 clade and that during evolution, eukaryote ALDH1/2s often switched between large and small SECs after gene duplication, transforming constricted channels into wide opened ones and vice versa. Ancestral sequence reconstructions suggest that during the evolutionary emergence of RA signaling, the ancestral, narrow-channeled metazoan ALDH1/2 gave rise to large ALDH1 channels capable of accommodating bulky aldehydes, such as retinaldehyde, supporting the view that retinoid-dependent signaling arose from ancestral cellular detoxification mechanisms. Our analyses also indicate that, on a more restricted evolutionary scale, ALDH1 duplicates from invertebrate chordates (amphioxus and ascidian tunicates) underwent switches to smaller and narrower SECs. When combined with alterations in gene expression, these switches led to neofunctionalization from ALDH1-like roles in embryonic patterning to systemic, ALDH2-like roles, suggesting functional shifts from signaling to detoxification. PMID:21169504

  13. Structural shifts of aldehyde dehydrogenase enzymes were instrumental for the early evolution of retinoid-dependent axial patterning in metazoans

    PubMed Central

    Sobreira, Tiago J. P.; Marlétaz, Ferdinand; Simões-Costa, Marcos; Schechtman, Deborah; Pereira, Alexandre C.; Brunet, Frédéric; Sweeney, Sarah; Pani, Ariel; Aronowicz, Jochanan; Lowe, Christopher J.; Davidson, Bradley; Laudet, Vincent; Bronner, Marianne; de Oliveira, Paulo S. L.; Schubert, Michael; Xavier-Neto, José

    2011-01-01

    Aldehyde dehydrogenases (ALDHs) catabolize toxic aldehydes and process the vitamin A-derived retinaldehyde into retinoic acid (RA), a small diffusible molecule and a pivotal chordate morphogen. In this study, we combine phylogenetic, structural, genomic, and developmental gene expression analyses to examine the evolutionary origins of ALDH substrate preference. Structural modeling reveals that processing of small aldehydes, such as acetaldehyde, by ALDH2, versus large aldehydes, including retinaldehyde, by ALDH1A is associated with small versus large substrate entry channels (SECs), respectively. Moreover, we show that metazoan ALDH1s and ALDH2s are members of a single ALDH1/2 clade and that during evolution, eukaryote ALDH1/2s often switched between large and small SECs after gene duplication, transforming constricted channels into wide opened ones and vice versa. Ancestral sequence reconstructions suggest that during the evolutionary emergence of RA signaling, the ancestral, narrow-channeled metazoan ALDH1/2 gave rise to large ALDH1 channels capable of accommodating bulky aldehydes, such as retinaldehyde, supporting the view that retinoid-dependent signaling arose from ancestral cellular detoxification mechanisms. Our analyses also indicate that, on a more restricted evolutionary scale, ALDH1 duplicates from invertebrate chordates (amphioxus and ascidian tunicates) underwent switches to smaller and narrower SECs. When combined with alterations in gene expression, these switches led to neofunctionalization from ALDH1-like roles in embryonic patterning to systemic, ALDH2-like roles, suggesting functional shifts from signaling to detoxification. PMID:21169504

  14. Aminosilica materials as adsorbents for the selective removal of aldehydes and ketones from simulated bio-oil.

    PubMed

    Drese, Jeffrey H; Talley, Anne D; Jones, Christopher W

    2011-03-21

    The fast pyrolysis of biomass is a potential route to the production of liquid biorenewable fuel sources. However, degradation of the bio-oil mixtures due to reaction of oxygenates, such as aldehydes and ketones, reduces the stability of the liquids and can impact long-term storage and shipping. Herein, solid aminosilica adsorbents are described for the selective adsorptive removal of reactive aldehyde and ketone species. Three aminosilica adsorbents are prepared through the reaction of amine-containing silanes with pore-expanded mesoporous silica. A fourth aminosilica adsorbent is prepared through the ring-opening polymerization of aziridine from pore-expanded mesoporous silica. Adsorption experiments with a representative mixture of bio-oil model compounds are presented using each adsorbent at room temperature and 45 °C. The adsorbent comprising only primary amines adsorbs the largest amount of aldehydes and ketones. The overall reactivity of this adsorbent increases with increasing temperature. Additional aldehyde screening experiments show that the reactivity of aldehydes with aminosilicas varies depending on their chemical functionality. Initial attempts to regenerate an aminosilica adsorbent by acid hydrolysis show that they can be at least partially regenerated for further use. PMID:21246749

  15. Isotopic composition of Murchison organic compounds: Intramolecular carbon isotope fractionation of acetic acid. Simulation studies of cosmochemical organic syntheses

    NASA Technical Reports Server (NTRS)

    Yuen, G. U.; Cronin, J. R.; Blair, N. E.; Desmarais, D. J.; Chang, S.

    1991-01-01

    Recently, in our laboratories, samples of Murchison acetic acid were decarboxylated successfully and the carbon isotopic composition was measured for the methane released by this procedure. These analyses showed significant differences in C-13/C-12 ratios for the methyl and carboxyl carbons of the acetic acid molecule, strongly suggesting that more than one carbon source may be involved in the synthesis of the Murchison organic compounds. On the basis of this finding, laboratory model systems simulating cosmochemical synthesis are being studied, especially those processes capable of involving two or more starting carbon sources.

  16. Inhibitory Effects of Caffeic Acid, a Coffee-Related Organic Acid, on the Propagation of Hepatitis C Virus.

    PubMed

    Tanida, Isei; Shirasago, Yoshitaka; Suzuki, Ryosuke; Abe, Ryo; Wakita, Takaji; Hanada, Kentaro; Fukasawa, Masayoshi

    2015-01-01

    Multipurpose cohort studies have demonstrated that coffee consumption reduces the risk of hepatocellular carcinoma (HCC). Given that one of the main causes of HCC is hepatitis C virus (HCV) infection, we examined the effect of caffeic acid, a major organic acid derived from coffee, on the propagation of HCV using an in vitro naïve HCV particle-infection and production system within human hepatoma-derived Huh-7.5.1-8 cells. When cells were treated with 1% coffee extract or 0.1% caffeic acid for 1-h post HCV infection, the amount of HCV particles released into the medium at 3 and 4 days post-infection considerably decreased. In addition, HCV-infected cells cultured with 0.001% caffeic acid for 4 days, also released less HCV particles into the medium. Caffeic acid treatment inhibited the initial stage of HCV infection (i.e., between virion entry and the translation of the RNA genome) in both HCV genotypes 1b and 2a. These results suggest that the treatment of cells with caffeic acid may inhibit HCV propagation. PMID:25672401

  17. Direct activation of GABAA receptors by substances in the organic acid fraction of Japanese sake.

    PubMed

    Izu, Hanae; Shigemori, Kensuke; Eguchi, Masaya; Kawane, Shuhei; Fujii, Shouko; Kitamura, Yuji; Aoshima, Hitoshi; Yamada, Yasue

    2017-01-01

    We investigated the effect of substances present in Japanese sake on the response of ionotropic γ-aminobutyric acid (GABA)A receptors expressed in Xenopus oocytes. Sake was fractionated by ion-exchange chromatography. The fraction containing organic acids (OA fraction) showed agonist activities on the GABAA receptor. OA fractions from sake were analyzed by capillary electrophoresis time-of-flight mass spectrometry (CE-TOFMS). Of the 64 compounds identified, 13 compounds showed GABAA receptor agonist activities. Especially, l-lactic acid showed high agonist activity and its EC50 value was 37μM. Intraperitoneal injections of l-lactic acid, gluconic acid, and pyruvic acid (10, 10, and 5mg/kg BW, respectively), which showed agonistic activity on the GABAA receptor, led to significant anxiolytic effects during an elevated plus-maze test in mice. PMID:27507485

  18. Determination of sugars, organic acids, aroma components, and carotenoids in grapefruit pulps.

    PubMed

    Zheng, Huiwen; Zhang, Qiuyun; Quan, Junping; Zheng, Qiao; Xi, Wanpeng

    2016-08-15

    The composition and content of sugars, organic acids, volatiles and carotenoids, in the pulps of six grapefruit cultivars, were examined by HPLC and GC-MS. The results showed that sucrose was the dominant sugar in grapefruit, making up 40.08-59.68% of the total sugars, and the ratio of fructose to glucose was almost 1:1. Citric acid was the major organic acid and represented 39.10-63.55% of the total organic acids, followed by quininic acid. The ratios of individual sugars and organic acids play an important role in grapefruit taste determination. Monoterpenes and sesquiterpenes were the predominant volatiles in grapefruit, in particular d-limonene and caryophyllene. Caryophyllene, α-humulene, humulen-(v1), β-linalool and tert-butyl 2-methylpropanoate are the characteristic aroma compounds of grapefruit. Although β-carotene is the primary carotenoid in grapefruit, the pulp color is mainly determined by the ratios of zeaxanthin, β-cryptoxanthin and lycopene. Our results provide the first complete chemical characterization of the taste, aroma and color of grapefruit. PMID:27006221

  19. Stable carbon isotopic compositions of organic acids in total suspended particles and dusts from Guangzhou, China

    NASA Astrophysics Data System (ADS)

    Ma, Shexia; Peng, Ping'an; Song, Jianzhong; Zhao, Jinping; He, Lulu; Sheng, Guoying; Fu, Jiamo

    2010-10-01

    Stable carbon isotopic compositions of individual organic acids were determined in total suspended particles and dusts from Guangzhou. The δ 13C values of high molecular weight n-alkanoic acids (C 20-C 28) varied from -34.1‰ to -32.4‰ and tended to be heavier in summer and lighter in winter. These δ 13C values indicate that high molecular weight n-alkanoic acids were derived mainly from emission by C 3 plants. Reduced biological synthesis of high molecular weight n-alkanoic acids in winter may be the reason for the light carbon isotopic composition. The δ 13C values of low molecular weight n-alkanoic acids (C 10-C 18) changed from -31.7‰ to -30.3‰ and exhibited a reverse seasonal trend, i.e., heavier in winter and lighter in summer. Slightly heavier δ 13C values of low molecular weight n-alkanoic acids than those of high molecular weight n-alkanoic acids suggested that they may be emitted from blended sources, e.g., anthropogenic sources and vegetation waxes. Lighter δ 13C values in summer may be attributed to relatively low anthropogenic sources and high botanic sources in summer. Dicarboxylic acids and aromatic acids have been proposed as secondary products from photochemical degradation. The average δ 13C values of dicarboxylic acids and aromatic acids were heavier, and ranged from -25.2‰ to -22.9‰ and from -30.0‰ to -27.6‰, respectively. Both dicarboxylic acids and aromatic acids displayed the same temporal variations in the δ 13C values, i.e., negative δ 13C in the summer samples and positive in the winter samples, which may be controlled by photochemical reactions; they are generally severe in winter in Guangzhou under the monsoon weather system. The heaviest δ 13C values were observed in dicarboxylic acids, indicating that dicarboxylic acids were formed by fast and more complete oxidation reactions. These results indicate that the stable carbon isotopic composition of organic acids may provide important information about sources and

  20. Relationship between cadmium, zinc, Cd-peptide, and organic acid in tobacco suspension cells

    SciTech Connect

    Krotz, R.M.; Evangelou, B.P.; Wagner, G.J. )

    1989-10-01

    Responses of tobacco (Nicotiana tabacum) suspension cells to Cd and Zn were studied in the presence and absence of ligand of Cd-peptide in order to understand the role of this peptide versus other mechanisms in Cd and Zn accumulation and accommodation in plants. With 45 micromolar Cd and 300 micromolar Zn (non-growth-inhibiting levels), metals appeared rapidly within cells, and intracellular Cd and Zn reached medium concentrations after 6 to 10 hours. Cd-peptide was observed in response to Cd after 2 hours, but this form only accounted for {approximately}30% of soluble Cd after 24 hours. Peptide was not observed in cells exposed to 300 micromolar Zn for up to 7 days. Organic acid-to-metal stoichiometry indicated that endogenous organic acid content of cells was more than sufficient to complex absorbed metals and no evidence was found for stimulation of organic acid biosynthesis by Cd or Zn. Metal-complexing potential of organic acids for Cd and Zn versus endogenous cations is discussed as is vacuolar-extravacuolar distribution of metals. The absence of Cd-peptide does not limit Cd-accumulation in the system studied. Results suggest that tobacco suspension cells accommodte the presence of non-growth-inhibiting and growth-inhibiting levels of Cd and Zn by sequestration in the vacuole as complexes with endogenous organic acids and that this may be a principal means for accommodation of Cd as well as Zn in the presence and absence of Cd-peptide.

  1. Protecting cell walls from binding aluminum by organic acids contributes to aluminum resistance.

    PubMed

    Li, Ya-Ying; Zhang, Yue-Jiao; Zhou, Yuan; Yang, Jian-Li; Zheng, Shao-Jian

    2009-06-01

    Aluminum-induced secretion of organic acids from the root apex has been demonstrated to be one major Al resistance mechanism in plants. However, whether the organic acid concentration is high enough to detoxify Al in the growth medium is frequently questioned. The genotypes of Al-resistant wheat, Cassia tora L. and buckwheat secrete malate, citrate and oxalate, respectively. In the present study we found that at a 35% inhibition of root elongation, the Al activities in the solution were 10, 20, and 50 muM with the corresponding malate, citrate, and oxalate exudation at the rates of 15, 20 and 21 nmol/cm(2) per 12 h, respectively, for the above three plant species. When exogenous organic acids were added to ameliorate Al toxicity, twofold and eightfold higher oxalate and malate concentrations were required to produce the equal effect by citrate. After the root apical cell walls were isolated and preincubated in 1 mM malate, oxalate or citrate solution overnight, the total amount of Al adsorbed to the cell walls all decreased significantly to a similar level, implying that these organic acids own an equal ability to protect the cell walls from binding Al. These findings suggest that protection of cell walls from binding Al by organic acids may contribute significantly to Al resistance. PMID:19522816

  2. Statistical Thermodynamic Model for Surface Tension of Aqueous Organic Acids with Consideration of Partial Dissociation.

    PubMed

    Boyer, Hallie C; Dutcher, Cari S

    2016-06-30

    With statistical mechanics, an isotherm-based surface tension model for single solute aqueous solutions was derived previously (Wexler et al. J. Phys. Chem. Lett. 2013) for the entire concentration range, from infinite dilution to pure liquid solute, as a function of solute activity. In recent work (Boyer et al. J. Phys. Chem. Lett. 2015), empirical model parameters were reduced through physicochemical interpretations of both electrolyte and organic solutes, enabling surface tension predictions for systems where there is little or no data. The prior binary model is extended in the current work for the first time to treat multicomponent systems to predict surface tensions of partially dissociating organic acids (acetic, butyric, citric, formic, glutaric, maleic, malic, malonic, oxalic, propionic, and succinic acids). These organic acids are especially applicable to the study of atmospheric aqueous aerosols, due to their abundance in the atmosphere. In the model developed here, surface tension depends explicitly on activities of both the neutral organic and deprotonated components of the acid. The relative concentrations of the nondissociated and dissociated mole fractions are found using known dissociation constants. Model parameters strongly depend on molecular size, number of functional groups, O:C ratio, and number of carbons. For all organic acids in this study, fully predictive modeling of surface tensions is demonstrated. PMID:27219322

  3. The effect of organic acids on plagioclase dissolution rates and stoichiometry

    NASA Astrophysics Data System (ADS)

    Welch, Susan A.; Ullman, William J.

    1993-06-01

    The rates of plagioclase dissolution in solutions containing organic acids are up to ten times greater than the rates determined in solutions containing inorganic acids at the same acidity. Initial rates of dissolution are poorly reproduced in replicate experiments. After a day, however, the rates of plagioclase dissolution calculated from the rates of silicon release are reproducible and constant for up to nineteen days. Steady-state rates of dissolution are highest (up to 1.3 × 10 -8 mol/m 2/sec) in acidic solutions (pH ≈ 3) and decrease (to 1 × 10 -11 mol/m 2/sec) as acidity decreases toward neutral pH. The polyfunctional acids, oxalate, citrate, succinate, pyruvate, and 2-ketoglutarate, are the most effective at promoting dissolution. Acetate and propionate are not as effective as the other organic acids but are nonetheless more effective than solutions containing only inorganic acids. The degree of ligand-promoted enhancement of dissolution rate (rate in organic-containing solution/rate in inorganic solution at the same pH) decreases as acidity increases, indicating that the ligand-promoted dissolution mechanism becomes relatively more important as the rate of proton-promoted dissolution decreases. The stoichiometry of release to solution indicates that dissolution is selective even after the rates of dissolution become constant. As in previously published studies, Na and Ca are rapidly released from the plagioclase feldspar, leaving a surface enriched in Si and/or Al. The ratio of Al/Si released to solution indicates that the stoichiometry of the residual plagioclase surface is a function of pH and the nature of the organic ligand. The ligands which remove Al in preference to Si from the dissolving mineral surface are also those which enhance overall plagioclase dissolution rates.

  4. Deoxyribonucleic acid methylation and chromatin organization in Tetrahymena thermophila.

    PubMed Central

    Pratt, K; Hattman, S

    1981-01-01

    Deoxyribonucleic acid (DNA) of the transcriptionally active macronucleus of Tetrahymena thermophila is methylated at the N6 position of adenine to produce methyladenine (MeAde); approximately 1 in every 125 adenine residues (0.8 mol%) is methylated. Transcriptionally inert micronuclear DNA is not methylated (< or = 0.01 mol% MeAde; M. A. Gorovsky, S. Hattman, and G. L. Pleger, J. Cell Biol. 56:697-701, 1973). There is no detectable cytosine methylation in macronuclei in Tetrahymena DNA (< or = 0.01 mol% 5-methylcytosine). MeAde-containing DNA sequences in macronuclei are preferentially digested by both staphylococcal nuclease and pancreatic deoxyribonuclease I. In contrast, there is no preferential release of MeAde during digestion of purified DNA. These results indicate that MeAde residues are predominantly located in "linker DNA" and perhaps have a function in transcription. Pulse-chase studies showed that labeled MeAde remains preferentially in linker DNA during subsequent rounds of DNA replication; i.e., there is little, if any, movement of nucleosomes during chromatin replication. This implies that nucleosomes may be phased with respect to DNA sequence. PMID:9279374

  5. [Relationships between cadmium accumulation and organic acids in leaves of Solanum nigrum L. as a cadmium-hyperaccumulator].

    PubMed

    Sun, Rui-lian; Zhou, Qi-xing; Wang, Xin

    2006-04-01

    The influence of different cadmium concentrations on the organic acid level in leaves of the Cd hyperaccumulator, Solanum nigrum L., in particular, the relationship of organic acids with Cd accumulation in S. nigrum was investigated based on the pot-culture experiment. The results showed that the Cd concentration in S. nigrum leaves exceeded 100 microg x g(-1), the threshold value used to define Cd-hyperaccumulators, and the bioaccumulation coefficient of cadmium in shoots of S. nigrum was higher than 1 when Cd concentration in soil was 25 microg x g(-1). The level of organic acids in leaves of S. nigrum had significant differences between the seedling stage and the mature stage. At the seedling stage, the sequence of organic acids in leaves of S. nigrum was acetic acid> tartaric acid> malic acid> citric acid. On the contrary, the accumulation of organic acids in S. nigrum at the mature stage was approximately in the following sequence malic acid> tartaric acid, acetic acid> citric acid. The significant positive correlation between Cd accumulation in leaves of S. nigrum and the concentration of tartaric acid in leaves of S. nigrum was observed at the seedling stage, whereas there was a significant positive correlation between Cd accumulation in leaves of S. nigrum and both acetic and citric acid concentrations at the mature stage. These results indicated that tartaric, acetic and citric acids in leaves of S. nigrum might act as the indication of Cd hyperaccumulation. PMID:16768003

  6. Reversible, partial inactivation of plant betaine aldehyde dehydrogenase by betaine aldehyde: mechanism and possible physiological implications.

    PubMed

    Zárate-Romero, Andrés; Murillo-Melo, Darío S; Mújica-Jiménez, Carlos; Montiel, Carmina; Muñoz-Clares, Rosario A

    2016-04-01

    In plants, the last step in the biosynthesis of the osmoprotectant glycine betaine (GB) is the NAD(+)-dependent oxidation of betaine aldehyde (BAL) catalysed by some aldehyde dehydrogenase (ALDH) 10 enzymes that exhibit betaine aldehyde dehydrogenase (BADH) activity. Given the irreversibility of the reaction, the short-term regulation of these enzymes is of great physiological relevance to avoid adverse decreases in the NAD(+):NADH ratio. In the present study, we report that the Spinacia oleracea BADH (SoBADH) is reversibly and partially inactivated by BAL in the absence of NAD(+)in a time- and concentration-dependent mode. Crystallographic evidence indicates that the non-essential Cys(450)(SoBADH numbering) forms a thiohemiacetal with BAL, totally blocking the productive binding of the aldehyde. It is of interest that, in contrast to Cys(450), the catalytic cysteine (Cys(291)) did not react with BAL in the absence of NAD(+) The trimethylammonium group of BAL binds in the same position in the inactivating or productive modes. Accordingly, BAL does not inactivate the C(450)SSoBADH mutant and the degree of inactivation of the A(441)I and A(441)C mutants corresponds to their very different abilities to bind the trimethylammonium group. Cys(450)and the neighbouring residues that participate in stabilizing the thiohemiacetal are strictly conserved in plant ALDH10 enzymes with proven or predicted BADH activity, suggesting that inactivation by BAL is their common feature. Under osmotic stress conditions, this novel partial and reversible covalent regulatory mechanism may contribute to preventing NAD(+)exhaustion, while still permitting the synthesis of high amounts of GB and avoiding the accumulation of the toxic BAL. PMID:26792760

  7. Generation of organic acids and monosaccharides by hydrolytic and oxidative transformation of food processing residues.

    PubMed

    Fischer, Klaus; Bipp, Hans-Peter

    2005-05-01

    Carbohydrate-rich biomass residues, i.e. sugar beet molasses, whey powder, wine yeast, potato peel sludge, spent hops, malt dust and apple marc, were tested as starting materials for the generation of marketable chemicals, e.g. aliphatic acids, sugar acids and mono-/disaccharides. Residues were oxidized or hydrolyzed under acidic or alkaline conditions applying conventional laboratory digestion methods and microwave assisted techniques. Yields and compositions of the oxidation products differed according to the oxidizing agent used. Main products of oxidation by 30% HNO(3) were acetic, glucaric, oxalic and glycolic acids. Applying H(2)O(2)/CuO in alkaline solution, the organic acid yields were remarkably lower with formic, acetic and threonic acids as main products. Gluconic acid was formed instead of glucaric acid throughout. Reaction of a 10% H(2)O(2) solution with sugar beet molasses generated formic and lactic acids mainly. Na(2)S(2)O(8) solutions were very inefficient at oxidizing the residues. Glucose, arabinose and galactose were formed during acidic hydrolysis of malt dust and apple marc. The glucose content reached 0.35 g per gram of residue. Important advantages of the microwave application were lower reaction times and reduced reagent demands. PMID:15607197

  8. Non-covalent bonded 2D-3D supramolecular architectures based on 4-dimethylaminopyridine and organic acids

    NASA Astrophysics Data System (ADS)

    Zhang, Huan; Jin, Shouwen; Wen, Xianhong; Liu, Bin; Fang, Yang; Zhang, Yani; Wang, Daqi

    2015-07-01

    Studies concentrating on non-covalent weak interactions between the organic base of 4-dimethylaminopyridine, and acidic derivatives have led to an increased understanding of the role 4-dimethylaminopyridine has in binding with the organic acid derivatives. Here anhydrous and hydrous multicomponent organic acid-base adducts of 4-dimethylaminopyridine have been prepared with organic acids such as 1,3-benzodioxole-5-carboxylic acid, p-aminobenzoic acid, 2,4-dihydroxybenzoic acid, 3,5-dihydroxybenzoic acid, 5-chlorosalicylic acid, 5-bromosalicylic acid, 5-nitrosalicylic acid, and 5-sulfosalicylic acid. The 4-dimethylaminopyridine is only monoprotonated. All compounds are organic salts with the 1:1 ratio of the cation and the anion. For the 5-sulfosalicylic acid only one H is ionized to exhibit the valence number of -1. The eight crystalline complexes were characterized by X-ray diffraction analysis, IR, mp, and elemental analysis. These structures adopted the hetero supramolecular synthons. Analysis of the crystal packing of 1-8 suggests that there are Nsbnd H⋯O, Osbnd H⋯O, and Osbnd H⋯S hydrogen bonds (charge assisted or neutral) between the organic acid and the 4-dimethylaminopyridine moieties in the studied compounds. Except the classical hydrogen bonding interactions, the secondary propagating interactions also play important roles in structure extension. For the synergistic effect of the various non-covalent interactions, the complexes displayed 2D-3D framework structures.

  9. 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. PMID:26046452

  10. Fractionation of Fe isotopes by soil microbes and organic acids

    USGS Publications Warehouse

    Brantley, Susan L.; Liermann, Laura; Bullen, Thomas D.

    2001-01-01

    Small natural variations in Fe isotopes have been attributed to biological cycling. However, without understanding the mechanism of fractionation, it is impossible to interpret such variations. Here we show that the δ56Fe of Fe dissolved from a silicate soil mineral by siderophore-producing bacteria is as much as 0.8% lighter than bulk Fe in the mineral. A smaller isotopic shift is observed for Fe released abiotically by two chelates, and the magnitude of the shift increases with affinity of the ligand for Fe, consistent with a kinetic isotope effect during hydrolysis of Fe at the mineral surface. Fe dissolved abiotically without chelates shows no isotopic shift. The δ56Fe of the exchange fraction on soil grains is also lighter by ~0.6%-1% than Fe from both hornblende and iron oxyhydroxides. The kinetic isotope effect is therefore preserved in open systems such as soils. when recorded in the rock record, Fe isotopic fractionation could document Fe transport by organic molecules or by microbes where such entities were present in the geologic past.

  11. Organic acids from lignocellulose: Candida lignohabitans as a new microbial cell factory.

    PubMed

    Bellasio, Martina; Mattanovich, Diethard; Sauer, Michael; Marx, Hans

    2015-05-01

    Biorefinery applications require microbial cell factories for the conversion of various sugars derived from lignocellulosic material into value-added chemicals. Here, the capabilities of the yeast Candida lignohabitans to utilize a range of such sugars is characterized. Substrates efficiently converted by this yeast include the pentoses xylose and arabinose. Genetic engineering of C. lignohabitans with the isolated endogenous GAP promoter and GAP terminator was successful. GFP expression was used as a proof of functionality for the isolated transcription elements. Expression of lactate dehydrogenase and cis-aconitate decarboxylase resulted in stable and reproducible production of lactic acid and itaconic acid, respectively. The desired organic acids were accumulated converting pure sugars as well as lignocellulosic hydrolysates. C. lignohabitans proved therefore to be a promising reliable microbial host for production of organic acids from lignocellulosic material. PMID:25651876

  12. Fluorescence method for enzyme analysis which couples aromatic amines with aromatic aldehydes

    DOEpatents

    Smith, Robert E. [557 Escondido Cir., Livermore, CA 94550; Dolbeare, Frank A. [5178 Diane La., Livermore, CA 94550

    1980-10-21

    Analysis of proteinases is accomplished using conventional amino acid containing aromatic amine substrates. Aromatic amines such as 4-methoxy-2-naphthylamine (4M2NA), 2-naphthylamine, aminoisophthalic acid dimethyl ester, p-nitroaniline, 4-methoxy-1-aminofluorene and coumarin derivatives resulting from enzymatic hydrolysis of the substrate couples with aromatic aldehydes such as 5-nitrosalicylaldehyde (5-NSA), benzaldehyde and p-nitrobenzaldehyde to produce Schiff-base complexes which are water insoluble. Certain Schiff-base complexes produce a shift from blue to orange-red (visible) fluorescence. Such complexes are useful in the assay of enzymes.

  13. Fluorescence method for enzyme analysis which couples aromatic amines with aromatic aldehydes

    DOEpatents

    Smith, Robert E.; Dolbeare, Frank A.

    1979-01-01

    Analysis of proteinases is accomplished using conventional amino acid containing aromatic amine substrates. Aromatic amines such as 4-methoxy-2-naphthylamine (4M2NA), 2-naphthylamine, aminoisophthalic acid dimethyl ester, p-nitroaniline, 5-methoxy-1-aminofluorene and coumarin derivatives resulting from enzymatic hydrolysis of the substrate couples with aromatic aldehydes such as 5-nitrosalicylaldehyde (5-NSA), benzaldehyde and p-nitrobenzaldehyde to produce Schiff-base complexes which are water insoluble. Certain Schiff-base complexes produce a shift from blue to orange-red (visible) fluorescence. Such complexes are useful in the assay of enzymes.

  14. Fluorescence method for enzyme analysis which couples aromatic amines with aromatic aldehydes

    DOEpatents

    Smith, R.E.; Dolbeare, F.A.

    1980-10-21

    Analysis of proteinases is accomplished using conventional amino acid containing aromatic amine substrates. Aromatic amines such as 4-methoxy-2-naphthylamine (4M2NA), 2-naphthylamine, aminoisophthalic acid dimethyl ester, p-nitroaniline, 4-methoxy-1-aminofluorene and coumarin derivatives resulting from enzymatic hydrolysis of the substrate couples with aromatic aldehydes such as 5-nitrosalicylaldehyde (5-NSA), benzaldehyde and p-nitrobenzaldehyde to produce Schiff-base complexes which are water insoluble. Certain Schiff-base complexes produce a shift from blue to orange-red (visible) fluorescence. Such complexes are useful in the assay of enzymes. No Drawings

  15. Gelled acidic well treating composition and process

    SciTech Connect

    Swanson, B.L.

    1981-01-13

    Gelled acidic compositions suitable for either matrix-acidizing or fracture-acidizing of subterranean formations comprising water , a water-dispersible polymer selected from cellulose ethers and polymers of acrylamides, an acid, an aldehyde, and a phenolic compound capable of causing gelation of an aqueous dispersion of the polymer, acid, aldehyde, and phenolic compound are provided. In another embodiment, guar gum, polyvinylpyrrolidone and biopolysaccharides can also be used as the polymeric component in said compositions.

  16. Uptake of Small Organic Compounds by Sulfuric Acid Aerosols: Dissolution and Reaction

    NASA Technical Reports Server (NTRS)

    Iraci, L. T.; Michelsen, R. R.; Ashbourn, S. F. M.; Staton, S. J. R.

    2003-01-01

    To assess the role of oxygenated volatile organic compounds in the upper troposphere and lower stratosphere, the interactions of a series of small organic compounds with low-temperature aqueous sulfuric acid will be evaluated. The total amount of organic material which may be taken up from the gas phase by dissolution, surface layer formation, and reaction during the particle lifetime will be quantified. Our current results for acetaldehyde uptake on 40 - 80 wt% sulfuric acid solutions will be compared to those of methanol, formaldehyde, and acetone to investigate the relationships between chemical functionality and heterogeneous activity. Where possible, equilibrium uptake will be ascribed to component pathways (hydration, protonation, etc.) to facilitate evaluation of other species not yet studied in low temperature aqueous sulfuric acid.

  17. Gas chromatographic organic acid profiling analysis of brandies and whiskeys for pattern recognition analysis.

    PubMed

    Park, Y J; Kim, K R; Kim, J H

    1999-06-01

    An efficient gas chromatographic profiling and pattern recognition method is described for brandy and whiskey samples according to their organic acid contents. It involves solid-phase extraction of organic acids using Chromosorb P with subsequent conversion to stable tert-butyldimethylsilyl derivatives for the direct analysis by capillary column gas chromatography and gas chromatography-mass spectrometry. A total of 12 organic acids were reproducibly identified in liquor samples (1 mL). When the GC profiles were simplified to their retention index spectra, characteristic patterns were obtained for each liquor sample as well as for each group average. Stepwise discriminant analysis provided star symbols characteristic for each liquor sample and group average. As expected, canonical discriminant analysis correctly classified 23 liquor samples studied into two groups of either brandy or whiskey. PMID:10794629

  18. Inhibition of human Cytochrome P450 2E1 and 2A6 by aldehydes: Structure and activity relationships

    PubMed Central

    Kandagatla, Suneel K.; Mack, Todd; Simpson, Sean; Sollenberger, Jill; Helton, Eric; Raner, Gregory M.

    2014-01-01

    The purpose of this study was to probe active site structure and dynamics of human cytochrome P4502E1 and P4502A6 using a series of related short chain fatty aldehydes. Binding efficiency of the aldehydes was monitored via their ability to inhibit the binding and activation of the probe substrates p-nitrophenol (2E1) and coumarin (2A6). Oxidation of the aldehydes was observed in reactions with individually expressed 2E1, but not 2A6, suggesting alternate binding modes. For saturated aldehydes the optimum chain length for inhibition of 2E1 was 9 carbons (KI=7.8 ±0.3 μM), whereas for 2A6 heptanal was most potent (KI=15.8 ±1.1 μM). A double bond in the 2-position of the aldehyde significantly decreased the observed KI relative to the corresponding saturated compound in most cases. A clear difference in the effect of the double bond was observed between the two isoforms. With 2E1, the double bond appeared to remove steric constraints on aldehyde binding with KI values for the 5–12 carbon compounds ranging between 2.6 ± 0.1 μM and 12.8± 0.5 μM, whereas steric effects remained the dominant factor in the binding of the unsaturated aldehydes to 2A6 (observed KI values between 7.0± 0.5 μM and >1000 μM). The aldehyde function was essential for effective inhibition, as the corresponding carboxylic acids had very little effect on enzyme activity over the same range of concentrations, and branching at the 3-position of the aldehydes increased the corresponding KI value in all cases examined. The results suggest that a conjugated π-system may be a key structural determinant in the binding of these compounds to both enzymes, and may also be an important feature for the expansion of the active site volume in 2E1. PMID:24924949

  19. [Determination of organic acids in cane vinasse by micellar electrokinetic capillary chromatography with indirect ultraviolet detection].

    PubMed

    Xu, Yuanjin; Xu, Guiping; Wei, Yuanan

    2006-01-01

    Micellar electrokinetic capillary chromatography (MECC) with indirect ultraviolet (UV) detection method for the separation and determination of several organic acids in cane vinasse, including malonic, formic, tartaric, malic, succinic, glutaric, acetic, lactic and glutamic acids, were developed. Electrophoretic conditions were as follows: uncoated fused silica capillary (56 cm/ 64 cm (effective/total length), 50 microm i. d. ), 7.5 mmol/L potassium acid phthalate-1. 5 mmol/L cetyltrimethyl-ammonium bromide (CTAB) at pH = 6.50 as buffer solution, applied voltage -25 kV, temperature 25 degrees C, detection wavelength 300 nm, reference wavelength 210 nm. Good linearities were obtained for nine organic acids, and the detection limits were 0.5 mg/L, 0.3 mg/L, 1.5 mg/L, 1.5 mg/L, 0.3 mg/L, 0.3 mg/L, 0.4 mg/L, 0.4 mg/L, 0.4 mg/L for malonic, formic, tartaric, malic, succinic, glutaric, acetic, lactic and glutamic acid, respectively. The relative standard deviations (RSDs) for migration times and peak areas of nine organic acids within a day were 0.4% - 0.6% and 2.3% - 4.8%, respectively. The corresponding data for five days were 0.5% -0.7% and 3.3% - 5.2%. The recoveries of acid standards were above 93%. The method can be applied to determine the organic acids in cane vinasse with satisfactory results. PMID:16827307

  20. The secretion of organic acids is also regulated by factors other than aluminum.

    PubMed

    Ding, Haiyan; Wen, Danni; Fu, Zhengwei; Qian, Haifeng

    2014-02-01

    As a result of natural processes and human activities, aluminum (Al) toxicity is recognized as a major limiting factor for plant productivity, and the secretion of organic acids facilitated by channel proteins is one of the most important Al resistance mechanisms in plants. The objective of this study was to evaluate the effects of several types of stress, including herbicide (imazethapyr (IM) and diclofop-methyl (DM)), heavy metal (Al and Cu), salt stress (NaCl), and proton stress (HCl), on the release of organic acids in rice. The results showed that 0.05 mg/L IM, 0.1 mg/L DM, 4680 mg/L NaCl, 0.5 mg/L CuSO4, and 18 mg/L AlCl3 significantly inhibited rice root elongation and the root fresh weight. In contrast, no significant inhibitory effects on rice growth were found with HCl (pH = 4.5). Similar to the effect of AlCl3 on organic acid induction, treatment with IM, DM, NaCl, and CuSO4 also induced the synthesis of endogenous citric acid and oxalic acid but decreased endogenous malic acid synthesis in the seedlings, though only citric acid was released into the environment after these treatments. We also analyzed the transcripts of three citrate channel proteins and found they were up-regulated by NaCl, CuSO4, and AlCl3 but not by IM or DM. This study clarified that organic acid secretion in plants might be a common phenomenon when plants are exposed to environmental stress other than Al toxicity. PMID:24097010

  1. Effects of organic acids on cadmium and copper sorption and desorption by two calcareous soils.

    PubMed

    Najafi, Sarvenaz; Jalali, Mohsen

    2015-09-01

    Low molecular weight organic acids (LMWOAs) present in soil alter equilibrium pH of soil, and consequently, affect heavy metal sorption and desorption on soil constitutes. This study was conducted to investigate the effects of different concentrations (0.1, 1, 2.5, 5, 10, 30, 40, 50, 70, and 100 mM) of citric, malic, and oxalic acids on sorption and desorption of cadmium (Cd) and copper (Cu) in two calcareous soils. Increasing the concentrations of three LMWOAs decreased the equilibrium pH of soil solutions. The results indicated that increase in organic acids concentrations generally reduced Cd and Cu sorption in soils. Increase concentrations of LMWOAs generally promoted Cd and Cu desorption from soils. A valley-like curve was observed for desorption of Cu after the citric acid concentration increment in soil 2. Increasing the concentrations of three LMWOAs caused a marked decrease in Kd(sorp) values of Cd and Cu in soils. In general, citric acid was the most effective organic acid in reducing sorption and increasing desorption of both metals, and oxalic acid had the minimal impact. The results indicated that LMWOAs had a greater impact on Cu sorption and desorption than Cd, which can be attributed to higher stability constants of organic acids complexes with Cu compared to Cd. It can be concluded that by selecting suitable type and concentration of LMWOAs, mobility, and hence, bioavailability of heavy metals can be changed. So, environmental implications concerning heavy metals mobility might be derived from these findings. PMID:26298186

  2. Crystal and molecular structures of twelve salts from isopropylamine and different organic acids

    NASA Astrophysics Data System (ADS)

    Wen, Xianhong; Zhang, Huan; Xu, Kai; Sun, JiaHui; Ye, Jiaying; Jin, Shouwen; Wang, Daqi

    2015-08-01

    Twelve isopropylamine derived supramolecular complexes isopropylamine: (m-toluic acid) [(Hipa)+ ṡ (mtua-), mtua- = m-toluate] (1), isopropylamine: (p-toluic acid) [(Hipa)+ ṡ (ptua-), ptua- = p-toluate] (2), isopropylamine: (p-methoxybenzoic acid) [(Hipa)+ ṡ (pmba-), pmba- = p-methoxybenzoate] (3), (isopropylamine): (3,4-methylenedioxybenzoic acid) [(Hipa)+ ṡ (mba)-, mba = 3,4-methylenedioxybenzoate] (4), (isopropylamine): (2-methyl-2-phenoxypropanoic acid) [(Hipa)+ ṡ (mpa-), mpa- = 2-methyl-2-phenoxypropionate] (5), (isopropylamine): (4-chlorophenoxyacetic acid) [(Hipa)+ ṡ (cpa-), cpa- = 4-chlorophenoxyacetate] (6), (isopropylamine): (3,5-dinitrobenzoic acid) [(Hipa)+ ṡ (dnba-), dnba- = 3,5-dinitrobenzoate] (7), (isopropylamine): (2-furoic acid) [(Hipa)+ ṡ (fura-), fura- = 2-furoate] (8), (isopropylamine): (1-hydroxy-2-naphthoic acid) [(Hipa)+ ṡ (hna), hna = 1-hydroxy-2-naphthoate] (9), (isopropylamine): (4-nitrophthalic acid) [(Hipa)2+ ṡ (npa2-), npa2- = 4-nitrophthalate] (10), (isopropylamine)2: (2,5-bis-isopropylcarbamoyl-terephthalic acid): 2H2O [(Hipa)2+ ṡ (bta2-) ṡ 2H2O, bta2- = 2,5-bis-isopropylcarbamoyl-terephthalate] (11), and (isopropylamine)2: (1,5-naphthalenedisulfonic acid) [(Hipa)2+ ṡ (nds2-), nds2- = 1,5-naphthalenedisulfonate] (12) were synthesized and structurally characterized by X-ray crystallography. All supramolecular architectures of 1-12 involve extensive classical hydrogen bonds as well as other non-covalent interactions. The results presented herein indicate that the strength and directionality of the Nsbnd H⋯O, Osbnd H⋯O, and Osbnd H⋯S hydrogen bonds between the acidic components and isopropylamine are sufficient to bring about the formation of binary organic salts. The role of weak and strong non-covalent interactions in the crystal packing is ascertained. These weak interactions combined, the complexes 1-12 displayed 1D-3D framework structure.

  3. Rapid simultaneous determination of amines and organic acids in citrus using high-performance liquid chromatography.

    PubMed

    Uckoo, Ram M; Jayaprakasha, Guddadarangavvanahally K; Nelson, Shad D; Patil, Bhimanagouda S

    2011-01-15

    Rapid analytical method for the simultaneous separation and determination of amines and organic acids is a vital interest for quality control of citrus and their products. In the present study, a simultaneous high performance liquid chromatography (HPLC) method for the rapid separation of three amines and two organic acids was developed. Chromatographic separation of compounds was achieved using Xbridge C(18) column at ambient temperature, with an isocratic mobile phase of 3mM phosphoric acid at a flow rate of 1.0 mL min(-1). A photodiode array (PDA) detector was used to monitor the eluent at 223 nm and 254 nm with a total analysis time of 10 min. Extraction of amines and organic acids from citrus juice was optimized. The method was validated by tests of linearity, recovery, precision and ruggedness. The limit of detection (LOD) and limit of quantification (LOQ) for amines and ascorbic acid were determined to be 5 ng and 9.8 ng, respectively. All calibration curves showed good linearity (R(2) ≥ 0.9999) within the test ranges. The recoveries of the amines and organic acids ranged between 84% and 117%. The identity of each peak was confirmed by mass spectral (MS) analysis. The developed method was successfully applied to analyze the content of amines and organic acids in six different species and two varieties of citrus. Results indicate that mandarin and Marrs sweet orange contain high level of amines, while pummelo and Rio Red grapefruit had high content of ascorbic acid (137-251 μg mL(-1)) and citric acid (5-22 mg mL(-1)). Synephrine was the major amine present in Clementine (114 μg mL(-1)) and Marrs sweet orange (85 μg mL(-1)). To the best of our knowledge, this is the first report on simultaneous separation and quantification of amines and organic acids in Marrs sweet orange, Meyer lemon, Nova tangerine, Clementine, Ugli tangelo and Wekiwa tangelo. PMID:21147342

  4. Prolonged acid rain facilitates soil organic carbon accumulation in a mature forest in Southern China.

    PubMed

    Wu, Jianping; Liang, Guohua; Hui, Dafeng; Deng, Qi; Xiong, Xin; Qiu, Qingyan; Liu, Juxiu; Chu, Guowei; Zhou, Guoyi; Zhang, Deqiang

    2016-02-15

    With the continuing increase in anthropogenic activities, acid rain remains a serious environmental threat, especially in the fast developing areas such as southern China. To detect how prolonged deposition of acid rain would influence soil organic carbon accumulation in mature subtropical forests, we conducted a field experiment with simulated acid rain (SAR) treatments in a monsoon evergreen broadleaf forest at Dinghushan National Nature Reserve in southern China. Four levels of SAR treatments were set by irrigating plants with water of different pH values: CK (the control, local lake water, pH ≈ 4.5), T1 (water pH=4.0), T2 (water pH=3.5), and T3 (water pH=3.0). Results showed reduced pH measurements in the topsoil exposed to simulated acid rains due to soil acidification. Soil respiration, soil microbial biomass and litter decomposition rates were significantly decreased by the SAR treatments. As a result, T3 treatment significantly increased the total organic carbon by 24.5% in the topsoil compared to the control. Furthermore, surface soil became more stable as more recalcitrant organic matter was generated under the SAR treatments. Our results suggest that prolonged acid rain exposure may have the potential to facilitate soil organic carbon accumulation in the subtropical forest in southern China. PMID:26657252

  5. Water solubility enhancement of some organic pollutants and pesticides by dissolved humic and fulvic acids

    USGS Publications Warehouse

    Chiou, C.T.; Malcolm, R.L.; Brinton, T.I.; Kile, D.E.

    1986-01-01

    Water solubility enhancements by dissolved humic and fulvic acids from soil and aquatic origins and by synthetic organic polymers have been determined for selected organic pollutants and pesticides (p,p???-DDT, 2,4,5,2???,5???-PCB, 2,4,4???-PCB, 1,2,3-trichlorobenzene, and lindane). Significant solubility enhancements of relatively water-insoluble solutes by dissolved organic matter (DOM) of soil and aquatic origins may be described in terms of a partition-like interaction of the the solutes with the microscopic organic environment of the high-molecular-weight DOM species; the apparent solute solubilities increase linearly with DOM concentration and show no competitive effect between solutes. With a given DOM sample, the solute partition coefficient (Kdom) increases with a decrease of solute solubility (Sw) or with an increase of the solute's octanol-water partition coefficient (Kow). The Kdom values of solutes with soil-derived humic acid are approximately 4 times greater than with soil fulvic acid and 5-7 times greater than with aquatic humic and fulvic acids. The effectiveness of DOM in enhancing solute solubility appears to be largely controlled by the DOM molecular size and polarity. The relative inability of high-molecular-weight poly(acrylic acids) to enhance solute solubility is attributed to their high polarities and extended chain structures that do not permit the formation of a sizable intramolecular nonpolar environment.

  6. Volatility of Organic Aerosol: Evaporation of Ammonium Sulfate/Succinic Acid Aqueous Solution Droplets

    PubMed Central

    2013-01-01

    Condensation and evaporation modify the properties and effects of atmospheric aerosol particles. We studied the evaporation of aqueous succinic acid and succinic acid/ammonium sulfate droplets to obtain insights on the effect of ammonium sulfate on the gas/particle partitioning of atmospheric organic acids. Droplet evaporation in a laminar flow tube was measured in a Tandem Differential Mobility Analyzer setup. A wide range of droplet compositions was investigated, and for some of the experiments the composition was tracked using an Aerosol Mass Spectrometer. The measured evaporation was compared to model predictions where the ammonium sulfate was assumed not to directly affect succinic acid evaporation. The model captured the evaporation rates for droplets with large organic content but overestimated the droplet size change when the molar concentration of succinic acid was similar to or lower than that of ammonium sulfate, suggesting that ammonium sulfate enhances the partitioning of dicarboxylic acids to aqueous particles more than currently expected from simple mixture thermodynamics. If extrapolated to the real atmosphere, these results imply enhanced partitioning of secondary organic compounds to particulate phase in environments dominated by inorganic aerosol. PMID:24107221

  7. Dietary Omega-3 Fatty Acids Modulate Large-Scale Systems Organization in the Rhesus Macaque Brain

    PubMed Central

    Kroenke, Christopher D.; Neuringer, Martha; Fair, Damien A.

    2014-01-01

    Omega-3 fatty acids are essential for healthy brain and retinal development and have been implicated in a variety of neurodevelopmental disorders. This study used resting-state functional connectivity MRI to define the large-scale organization of the rhesus macaque brain and changes associated with differences in lifetime ω-3 fatty acid intake. Monkeys fed docosahexaenoic acid, the long-chain ω-3 fatty acid abundant in neural membranes, had cortical modular organization resembling the healthy human brain. In contrast, those with low levels of dietary ω-3 fatty acids had decreased functional connectivity within the early visual pathway and throughout higher-order associational cortex and showed impairment of distributed cortical networks. Our findings illustrate the similarity in modular cortical organization between the healthy human and macaque brain and support the notion that ω-3 fatty acids play a crucial role in developing and/or maintaining distributed, large-scale brain systems, including those essential for normal cognitive function. PMID:24501348

  8. High concentrations of furan fatty acids in organic butter samples from the German market.

    PubMed

    Wendlinger, Christine; Vetter, Walter

    2014-08-27

    Furan fatty acids (F-acids) are valuable antioxidants containing a furan moiety in the central part of the molecule. They occur in the lipids of different foodstuffs and plants, with grass being the main source for their presence in milk fat and butter. Because cows from organic farming receive higher portions of grass-based feed, it was tested whether organic butter samples (n = 26) contain more F-acids than conventional ones (n = 25) in Germany. For this purpose, samples were melted, and the lipid phase was separated and transesterified into methyl esters, which were enriched using silver ion chromatography and analyzed by GC-EI/MS in the selected ion monitoring (SIM) mode. Levels of F-acids in butter were higher in summer than in winter, and in both seasons, organic samples contained significantly higher levels of F-acids than conventional ones (one-way ANOVA: p < 0.001). Furthermore, the daily intake of F-acids via milk fat and other foodstuffs was calculated. PMID:25098958

  9. Study of the organic acids composition of quince (Cydonia oblonga Miller) fruit and jam.

    PubMed

    Silva, Branca M; Andrade, Paula B; Mendes, Gisela C; Seabra, Rosa M; Ferreira, Margarida A

    2002-04-10

    The organic acids present in several samples of quince fruit (pulp and peel) and quince jam (homemade and industrially manufactured) were analyzed by HPLC. The sample preparation was simple, involving only extraction with methanol (40 degrees C) and filtration through a Sep-pack C18 cartridge. The chromatographic separation was achieved using an ion exclusion column, Nucleogel Ion 300 OA (300 x 7.7 mm), in conjunction with a column heating device at 30 degrees C. An isocratic elution with H(2)SO(4) 0.01 N as the mobile phase, with a flow rate of 0.1 mL/min, and UV detection at 214 nm were used. These analyses showed that all samples presented a similar profile composed of at least six identified organic acids: citric, ascorbic, malic, quinic, shikimic, and fumaric acids. Several samples also contained oxalic acid. This study suggests that the organic acids levels and ratios may be useful for the determination of percent fruit content of quince jams. The citric acid value can also be used in the differentiation of the type of manufacture of the commercial quince jams (homemade or industrially manufactured). PMID:11929290

  10. Organic acids as cloud condensation nuclei: Laboratory studies of highly soluble and insoluble species

    NASA Astrophysics Data System (ADS)

    Pradeep Kumar, P.; Broekhuizen, K.; Abbatt, J. P. D.

    2003-05-01

    The ability of sub-micron-sized organic acid particles to act as cloud condensation nuclei (CCN) has been examined at room temperature using a newly constructed continuous-flow, thermal-gradient diffusion chamber (TGDC). The organic acids studied were: oxalic, malonic, glutaric, oleic and stearic. The CCN properties of the highly soluble acids - oxalic, malonic and glutaric - match very closely Köhler theory predictions which assume full dissolution of the dry particle and a surface tension of the growing droplet equal to that of water. In particular, for supersaturations between 0.3 and 0.6, agreement between the dry particle diameter which gives 50% activation and that calculated from Köhler theory is to within 3nm on average. In the course of the experiments, considerable instability of glutaric acid particles was observed as a function of time and there is evidence that they fragment to some degree to smaller particles. Stearic acid and oleic acid, which are both highly insoluble in water, did not activate at supersaturations of 0.6% with dry diameters up to 140nm. Finally, to validate the performance of the TGDC, we present results for the activation of ammonium sulfate particles that demonstrate good agreement with Köhler theory if solution non-ideality is considered. Our findings support earlier studies in the literature that showed highly soluble organics to be CCN active but insoluble species to be largely inactive.

  11. [Effects of simulated acid rain on decomposition of soil organic carbon and crop straw].

    PubMed

    Zhu, Xue-Zhu; Huang, Yao; Yang, Xin-Zhong

    2009-02-01

    To evaluate the effects of acid rain on the organic carbon decomposition in different acidity soils, a 40-day incubation test was conducted with the paddy soils of pH 5.48, 6.70 and 8.18. The soils were amended with 0 and 15 g x kg(-1) of rice straw, adjusted to the moisture content of 400 g x kg(-1) air-dried soil by using simulated rain of pH 6.0, 4.5, and 3.0, and incubated at 20 degrees C. The results showed that straw, acid rain, and soil co-affected the CO2 emission from soil system. The amendment of straw increased the soil CO2 emission rate significantly. Acid rain had no significant effects on soil organic carbon decomposition, but significantly affected the straw decomposition in soil. When treated with pH 3.0 acid rain, the amount of decomposed straw over 40-day incubation in acid (pH 5.48) and alkaline (pH 8.18) soils was 8% higher, while that in neutral soil (pH 6.70) was 15% lower, compared to the treatment of pH 6.0 rain. In the treatment of pH 3.0 acid rain, the decomposition rate of soil organic C in acid (pH 5.48) soil was 43% and 50% (P < 0.05) higher than that in neutral (pH 6.70) and alkaline (pH 8.18) soils, while the decomposition rate of straw in neutral soil was 17% and 16% (P < 0.05) lower than that in acid and alkaline soils, respectively. PMID:19459394

  12. Seasonal and spatial changes of free and bound organic acids in total suspended particles in Guangzhou, China

    NASA Astrophysics Data System (ADS)

    Ma, Shexia; Peng, Ping'an; Song, Jianzhong; Bi, Xinhui; Zhao, Jinping; He, Lulu; Sheng, Guoying; Fu, Jiamo

    2010-12-01

    The concentrations and compositions of free and bound organic acids in total suspended particles from typical urban, suburban and forest park sites of Guangzhou were determined in this study. The free form of organic acids (solvent extractable) in aerosols in Guangzhou varied with site and season. The suburban samples contained the highest contents of alkanoic, alkenoic and dicarboxylic acids. These findings were consistent with a higher supply of hydrocarbons and NOx in the suburban area. However, concentrations of aromatic acids were similar in the urban, suburban and forest park sites. Generally, winter season samples of the acids from anthropogenic sources contained more organic acids than summer season samples due to stronger removal by wet deposition in the summer. For the acids from botanic sources, the summer season samples were higher. In addition to the free acids, bound acids (solvent non-extractable) mainly formed by esterification of free acids were also found in the samples. In general, bound acids were higher than free acids. Esterification is mainly controlled by the pKa of organic acids and the atmospheric pH value. This explains why aromatic and dicarboxylic acids occur mainly as bound forms and why the samples from urban sites contained high levels of bound acids as the pH of rain water can reach 4.53. Concentrations of alkanoic and alkenoic acids in the aerosols of Guangzhou were much higher than those in the other areas studied.

  13. Does acute exposure to aldehydes impair pulmonary function and structure?

    PubMed

    Abreu, Mariana de; Neto, Alcendino Cândido; Carvalho, Giovanna; Casquillo, Natalia Vasconcelos; Carvalho, Niedja; Okuro, Renata; Ribeiro, Gabriel C Motta; Machado, Mariana; Cardozo, Aléxia; Silva, Aline Santos E; Barboza, Thiago; Vasconcellos, Luiz Ricardo; Rodrigues, Danielle Araujo; Camilo, Luciana; Carneiro, Leticia de A M; Jandre, Frederico; Pino, Alexandre V; Giannella-Neto, Antonio; Zin, Walter A; Corrêa, Leonardo Holanda Travassos; Souza, Marcio Nogueira de; Carvalho, Alysson R

    2016-07-15

    Mixtures of anhydrous