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Sample records for alcohols aldehydes ketones

  1. Iron/ABNO-Catalyzed Aerobic Oxidation of Alcohols to Aldehydes and Ketones under Ambient Atmosphere.

    PubMed

    Wang, Lianyue; Shang, SenSen; Li, Guosong; Ren, Lanhui; Lv, Ying; Gao, Shuang

    2016-03-01

    We report a new Fe(NO3)3·9H2O/9-azabicyclo[3.3.1]nonan-N-oxyl catalyst system that enables efficient aerobic oxidation of a broad range of primary and secondary alcohols to the corresponding aldehydes and ketones at room temperature with ambient air as the oxidant. The catalyst system exhibits excellent activity and selectivity for primary aliphatic alcohol oxidation. This procedure can also be scaled up. Kinetic analysis demonstrates that C-H bond cleavage is the rate-determining step and that cationic species are involved in the reaction. PMID:26859251

  2. Catalytic asymmetric reductive coupling of alkynes and aldehydes: enantioselective synthesis of allylic alcohols and alpha-hydroxy ketones.

    PubMed

    Miller, Karen M; Huang, Wei-Sheng; Jamison, Timothy F

    2003-03-26

    A highly enantioselective method for catalytic reductive coupling of alkynes and aldehydes is described. Allylic alcohols are afforded with complete E/Z selectivity, generally >95:5 regioselectivity, and in up to 96% ee. In conjunction with ozonolysis, this process is complementary to existing methods of enantioselective alpha-hydroxy ketone synthesis. PMID:12643701

  3. ADVANCED EMISSIONS SPECIATION METHODOLOGIES FOR THE AUTO/OIL AIR QUALITY IMPROVEMENT RESEARCH PROGRAM - II. ALDEHYDES, KETONES, AND ALCOHOLS

    EPA Science Inventory

    Analytical methods for determining individual aldehyde, ketone, and alcohol emissions from gasoline-, methanol-, and variable-fueled vehicles are described. These methods were used in the Auto/Oil Air quality Improvement Research Program to provide emission data for comparison of...

  4. Chemoselective Oxidation of Benzyl, Amino, and Propargyl Alcohols to Aldehydes and Ketones under Mild Reaction Conditions

    PubMed Central

    Reddy, C B Rajashekar; Reddy, Sabbasani Rajasekhara; Naidu, Shivaji

    2015-01-01

    Catalytic oxidation reactions often suffer from drawbacks such as low yields and poor selectivity. Particularly, selective oxidation of alcohols becomes more difficult when a compound contains more than one oxidizable functional group. In order to deliver a methodology that addresses these issues, herein we report an efficient, aerobic, chemoselective and simplified approach to oxidize a broad range of benzyl and propargyl alcohols containing diverse functional groups to their corresponding aldehydes and ketones in excellent yields under mild reaction conditions. Optimal yields were obtained at room temperature using 1 mmol substrate, 10 mol % copper(I) iodide, 10 mol % 4-dimethylaminopyridine (DMAP), and 1 mol % 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO) in acetonitrile, under an oxygen balloon. The catalytic system can be applied even when sensitive and oxidizable groups such as alkynes, amines, and phenols are present; starting materials and products containing such groups were found to be stable under the developed conditions. PMID:25969806

  5. Chemoselective Oxidation of Benzyl, Amino, and Propargyl Alcohols to Aldehydes and Ketones under Mild Reaction Conditions.

    PubMed

    Reddy, C B Rajashekar; Reddy, Sabbasani Rajasekhara; Naidu, Shivaji

    2015-04-01

    Catalytic oxidation reactions often suffer from drawbacks such as low yields and poor selectivity. Particularly, selective oxidation of alcohols becomes more difficult when a compound contains more than one oxidizable functional group. In order to deliver a methodology that addresses these issues, herein we report an efficient, aerobic, chemoselective and simplified approach to oxidize a broad range of benzyl and propargyl alcohols containing diverse functional groups to their corresponding aldehydes and ketones in excellent yields under mild reaction conditions. Optimal yields were obtained at room temperature using 1 mmol substrate, 10 mol % copper(I) iodide, 10 mol % 4-dimethylaminopyridine (DMAP), and 1 mol % 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO) in acetonitrile, under an oxygen balloon. The catalytic system can be applied even when sensitive and oxidizable groups such as alkynes, amines, and phenols are present; starting materials and products containing such groups were found to be stable under the developed conditions. PMID:25969806

  6. [Determination of low-carbon alcohols, aldehydes and ketones in aqueous products of Fischer-Tropsch synthesis by gas chromatography].

    PubMed

    Gai, Qingqing; Wu, Peng; Shi, Yulin; Bai, Yu; Long, Yinhua

    2015-01-01

    A method for the determination of low-carbon (C1-C8) alcohols, aldehydes and ketones in aqueous products of Fischer-Tropsch synthesis was developed by gas chromatography. It included the optimization of separation conditions, the precision and accuracy of determination, and the use of correction factors of the analytes to ethanol for quantification. The aqueous products showed that the correlation coefficients for ethanol in different content ranges were above 0.99, which means it had good linear correlations. The spiked recoveries in the aqueous samples of Fischer-Tropsch synthesis were from 93.4% to 109.6%. The accuracy of the method can satisfy the requirement for the analysis of the aqueous samples of Fischer-Tropsch synthesis. The results showed that the total mass fractions of the major low-carbon alcohols, aldehydes, ketones in aqueous products of Fischer-Tropsch synthesis were about 3%-12%, and the contents of ethanol were the highest (about 1.7%-7.3%). The largest share of the total proportion was n-alcohols, followed by isomeric alcohols, aldehydes and ketones were the lowest. This method is simple, fast, and has great significance for the analysis of important components in aqueous products of Fischer-Tropsch synthesis. PMID:25958675

  7. Mechanistic Insights on the Hydrogenation of α,β-Unsaturated Ketones and Aldehydes to Unsaturated Alcohols over Metal Catalysts

    SciTech Connect

    Ide, Matthew S.; Hao, Bing; Neurock, Matthew; Davis, Robert J.

    2012-04-06

    The selective hydrogenation of unsaturated ketones (methyl vinyl ketone and benzalacetone) and unsaturated aldehydes (crotonaldehyde and cinnamaldehyde) was carried out with H₂ at 2 bar absolute over Pd/C, Pt/C, Ru/C, Au/C, Au/TiO₂, or Au/Fe₂O₃ catalysts in ethanol or water solvent at 333 K. Comparison of the turnover frequencies revealed Pd/C to be the most active hydrogenation catalyst, but the catalyst failed to produce unsaturated alcohols, indicating hydrogenation of the C=C bond was highly preferred over the C=O bond on Pd. The Pt and Ru catalysts were able to produce unsaturated alcohols from unsaturated aldehydes, but not from unsaturated ketones. Although Au/ Fe₂O₃ was able to partially hydrogenate unsaturated ketones to unsaturated alcohols, the overall hydrogenation rate over gold was the lowest of all of the metals examined. First-principles density functional theory calculations were therefore used to explore the reactivity trends of methyl vinyl ketone (MVK) and benzalacetone (BA) hydrogenation over model Pt(111) and Ru(0001) surfaces. The observed selectivity over these metals is likely controlled by the significantly higher activation barriers to hydrogenate the C=O bond compared with those required to hydrogenate the C=C bond. Both the unsaturated alcohol and the saturated ketone, which are the primary reaction products, are strongly bound to Ru and can react further to the saturated alcohol. The lower calculated barriers for the hydrogenation steps over Pt compared with Ru account for the higher observed turnover frequencies for the hydrogenation of MVK and BA over Pt. The presence of a phenyl substituent α to the C=C bond in BA increased the barrier for C=C hydrogenation over those associated with the C=C bond in MVK; however, the increase in barriers with phenyl substitution was not adequate to reverse the selectivity trend.

  8. 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

  9. Syntheses of [omega]-alkynyl aldehydes and ketones via oxidation of [omega]-alkynyl alcohols with pyridinium dichromate

    SciTech Connect

    Bierer, D.E.; Kabalka, G.W. )

    1988-01-01

    Pyridinium dichromate (PDC) is an effective reagent for the oxidation of alcohols and a number of modifications of the original procedure have been reported. Interestingly, PDC has never been used to oxidize non-conjugated acetylenic alcohols. As a part of a project involving the chemical preparation of a number of unsaturated amino acids, the authors investigated the synthesis of a series of [omega]-alkynyl aldehydes. The authors now report that the PDC oxidation of [omega]-alkynyl alcohols is an effective route to the corresponding [omega]-alkynyl carbonyl compounds.

  10. 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

  11. 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

  12. 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

  13. ANALYSIS OF ALDEHYDES AND KETONES IN THE GAS PHASE

    EPA Science Inventory

    The development and testing of a 2,4-dinitrophenylhydrazine-acetonitrile (DNPH-ACN) method for the analysis of aldehydes and ketones in ambient air are described. A discussion of interferences, preparation of calibration standards, analytical testing, fluorescence methods and car...

  14. 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

  15. 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

  16. Enzymatic Chemoselective Aldehyde-Ketone Cross-Couplings through the Polarity Reversal of Methylacetoin.

    PubMed

    Bernacchia, Giovanni; Bortolini, Olga; De Bastiani, Morena; Lerin, Lindomar Alberto; Loschonsky, Sabrina; Massi, Alessandro; Müller, Michael; Giovannini, Pier Paolo

    2015-06-01

    The thiamine diphosphate (ThDP) dependent enzyme acetoin:dichlorophenolindophenol oxidoreductase (Ao:DCPIP OR) from Bacillus licheniformis was cloned and overexpressed in Escherichia coli. The recombinant enzyme shared close similarities with the acetylacetoin synthase (AAS) partially purified from Bacillus licheniformis suggesting that they could be the same enzyme. The product scope of the recombinant Ao:DCPIP OR was expanded to chiral tertiary α-hydroxy ketones through the rare aldehyde-ketone cross-carboligation reaction. Unprecedented is the use of methylacetoin as the acetyl anion donor in combination with a range of strongly to weakly activated ketones. In some cases, Ao:DCPIP OR produced the desired tertiary alcohols with stereochemistry opposite to that obtained with other ThDP-dependent enzymes. The combination of methylacetoin as acyl anion synthon and novel ThDP-dependent enzymes considerably expands the available range of C-C bond formations in asymmetric synthesis. PMID:25914187

  17. On the nature of the olefination reaction involving ditungsten hexaalkoxides and aldehydes or ketones

    SciTech Connect

    Chisholm, M.H.; Huffman, J.C.; Lucas, E.A.; Sousa, A.; Streib, W.E.

    1992-03-25

    Reductive coupling of aldehydes and ketones to olefins under the action of ditungsten hexaalkoxides was investigated. In these reactions, reductive cleavage of the aldehyde or ketone carbonyl is followed by formation of the olefinic C-C bond and breaking of the carbonyl C-O bond of the second aldehyde or ketone. Observations concerning the initial C-O bond cleavage and subsequent C-C bond formation are presented. 10 refs., 4 figs.

  18. [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

  19. Electron impact ionization of cycloalkanes, aldehydes, and ketones

    SciTech Connect

    Gupta, Dhanoj; Antony, Bobby

    2014-08-07

    The theoretical calculations of electron impact total ionization cross section for cycloalkane, aldehyde, and ketone group molecules are undertaken from ionization threshold to 2 keV. The present calculations are based on the spherical complex optical potential formalism and complex scattering potential ionization contribution method. The results of most of the targets studied compare fairly well with the recent measurements, wherever available and the cross sections for many targets are predicted for the first time. The correlation between the peak of ionization cross sections with number of target electrons and target parameters is also reported. It was found that the cross sections at their maximum depend linearly with the number of target electrons and with other target parameters, confirming the consistency of the values reported here.

  20. RuHCl(CO)(PPh3)3-catalyzed α-alkylation of ketones with primary alcohols.

    PubMed

    Kuwahara, Takashi; Fukuyama, Takahide; Ryu, Ilhyong

    2012-09-21

    The α-alkylation reaction of ketones with primary alcohols to give α-alkylated ketones was achieved using RuHCl(CO)(PPh(3))(3) as a catalyst in the presence of Cs(2)CO(3) as a base. This reaction proceeds via an aldol condensation of ketones with aldehydes, formed via transfer dehydrogenation of alcohols, to give α,β-unsaturated ketones, which then undergo transfer hydrogenation with primary alcohols to give α-alkylated ketones and aldehydes, the latter of which participate in the next catalytic cycle. While the reaction of aliphatic primary alcohols was sluggish compared with that of benzylic alcohols, a catalytic amount of 1,10-phenanthroline was found to promote the alkylation dramatically. PMID:22931460

  1. Direct Conversion of Aldehydes and Ketones to Allylic Halides by a NbX5-[3,3] Rearrangement

    PubMed Central

    Fleming, Fraser F.; Ravikumar, P. C.; Yao, Lihua

    2009-01-01

    Sequential addition of vinylmagnesium bromide and NbCl5, or NbBr5, to a series of aldehydes and ketones directly provides homologated, allylic halides. Transposition of the intermediate vinyl alkoxide is envisaged through a metalla-halo-[3,3] rearrangement with concomitant delivery of the halogen to the terminal carbon. The [3,3] rearrangement is equally effective for the conversion of a propargyllic alcohol to the corresponding allenyl bromide. PMID:20046989

  2. Cyclohexenylboration of Aldehydes and Ketones with the Borabicyclo[3.3.2]decanes (BBDs).

    PubMed

    González, Eduvigis; Muñoz-Hernández, Lorell; Alicea, Eyleen; Singaram, Bakthan; Kabalka, George W; Soderquist, John A

    2015-09-01

    Asymmetric hydroboration of 1,3-cyclohexadiene with 4R produces the allylborane 5RR as essentially a single diastereomer (i.e., no observable 5RS), and its addition to representative aldehydes provides 9RS (52-75%) with excellent selectivity (94-99% ee). By contrast, a similar sequence with the 10-Ph-BBD reagent, 14R, results in a ca. 45:55 mixture of 15RR and 15RS. However, their addition to methyl ketones provides the corresponding 3°-homoallylic alcohols (18RS) with excellent selectivity (80-99% ee) but in low yields (15-52%) because 15RS is unreactive toward either allylboration or isomerization to 15RR. Thus, with 2 equiv of 15, the yield of 18 (R = Ph) is increased from 52% to 85%. Boranes 5SS and 15SS provide enantiomeric alcohols. PMID:26284657

  3. Studies of the condensation of sulfones with ketones and aldehydes.

    PubMed

    Garst, Michael E; Dolby, Lloyd J; Esfandiari, Shervin; Okrent, Rachel A; Avey, Alfred A

    2006-01-20

    [reaction: see text] The condensation of ketones or aldehydes with sulfones was shown to give a variety of products. Condensation of 2-methylcyclohexanone with dimethyl sulfone using potassium t-butoxide as base gave useful yields of 1,2-dimethylenecyclohexane. Under the same conditions, cycloheptanone, 3-methyl-2-butanone, and 2-butanone were converted to dienes. Remarkably, these reaction conditions converted acetophenone into p-terphenyl (10%) and (E)-1,4-diphenyl-3-penten-1-one (44%). Propiophenone was converted to 2'-methyl-p-terphenyl (61%). Using alpha-tetralone produced 1-methynaphthalene and naphthalene. No reaction took place with beta-tetralone. Using diethyl sulfone with alpha-tetralone lead to pure naphthalene. Condensation of isobutyraldehyde and dimethyl sulfone using potassium t-butoxide gave isoprene in low yield. Using benzaldehyde and benzyl phenyl sulfone in N,N-dimethylacetamide gave 1,2-diphenyl-1-phenylsulfonylethylene, N,N-dimethylcinnamide, and a complex condensation product. Only 1,2-diphenyl-1-phenylsulfonylethylene was obtained when the solvent was THF. PMID:16408963

  4. Photoredox Activation for the Direct β-Arylation of Ketones and Aldehydes

    PubMed Central

    Pirnot, Michael T.; Rankic, Danica A.; Martin, David B. C.; MacMillan, David W. C.

    2013-01-01

    The direct β-activation of saturated aldehydes and ketones has long been an elusive transformation. We found that photoredox catalysis in combination with organocatalysis can lead to the transient generation of 5π-electron β-enaminyl radicals from ketones and aldehydes that rapidly couple with cyano-substituted aryl rings at the carbonyl β-position. This mode of activation is suitable for a broad range of carbonyl β-functionalization reactions and is amenable to enantioselective catalysis. PMID:23539600

  5. Selective Catalytic Hydrogenations of Nitriles, Ketones, and Aldehydes by Well-Defined Manganese Pincer Complexes.

    PubMed

    Elangovan, Saravanakumar; Topf, Christoph; Fischer, Steffen; Jiao, Haijun; Spannenberg, Anke; Baumann, Wolfgang; Ludwig, Ralf; Junge, Kathrin; Beller, Matthias

    2016-07-20

    Hydrogenations constitute fundamental processes in organic chemistry and allow for atom-efficient and clean functional group transformations. In fact, the selective reduction of nitriles, ketones, and aldehydes with molecular hydrogen permits access to a green synthesis of valuable amines and alcohols. Despite more than a century of developments in homogeneous and heterogeneous catalysis, efforts toward the creation of new useful and broadly applicable catalyst systems are ongoing. Recently, Earth-abundant metals have attracted significant interest in this area. In the present study, we describe for the first time specific molecular-defined manganese complexes that allow for the hydrogenation of various polar functional groups. Under optimal conditions, we achieve good functional group tolerance, and industrially important substrates, e.g., for the flavor and fragrance industry, are selectively reduced. PMID:27219853

  6. 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.

  7. 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

  8. Drosophila melanogaster alcohol dehydrogenase: mechanism of aldehyde oxidation and dismutation.

    PubMed

    Winberg, J O; McKinley-McKee, J S

    1998-02-01

    Drosophila alcohol dehydrogenase (Adh) catalyses the oxidation of both alcohols and aldehydes. In the latter case, the oxidation is followed by a reduction of the aldehyde, i.e. a dismutation reaction. At high pH, dismutation is accompanied by a small release of NADH, which is not observed at neutral pH. Previously it has been emphasized that kinetic coefficients obtained by measuring the increase in A340, i.e. the release of NADH at high pH is not a direct measure of the aldehyde oxidation reaction and these values cannot be compared with those for alcohol dehydrogenation. In this article we demonstrate that this is not entirely true, and that the coefficients phiB and phiAB, where B is the aldehyde and A is NAD+, are the same for a dismutation reaction and a simple aldehyde dehydrogenase reaction. Thus the substrate specificity of the aldehyde oxidation reaction can be determined by simply measuring the NADH release. The coefficients for oxidation and dehydrogenation reactions (phi0d and phiAd respectively) are complex and involve the constants for the dismutation reaction. However, dead-end inhibitors can be used to determine the quantitative contribution of the kinetic constants for the aldehyde oxidation and reduction pathways to the phi0d and phiAd coefficients. The combination of dead-end and product inhibitors can be used to determine the reaction mechanism for the aldehyde oxidation pathway. Previously, we showed that with Drosophila Adh, the interconversion between alcohols and aldehydes followed a strictly compulsory ordered pathway, although aldehydes and ketones formed binary complexes with the enzyme. This raised the question regarding the reaction mechanism for the oxidation of aldehydes, i.e. whether a random ordered pathway was followed. In the present work, the mechanism for the oxidation of different aldehydes and the accompanying dismutation reaction with the slow alleloenzyme (AdhS) from Drosophila melanogaster has been studied. To obtain

  9. Drosophila melanogaster alcohol dehydrogenase: mechanism of aldehyde oxidation and dismutation.

    PubMed Central

    Winberg, J O; McKinley-McKee, J S

    1998-01-01

    Drosophila alcohol dehydrogenase (Adh) catalyses the oxidation of both alcohols and aldehydes. In the latter case, the oxidation is followed by a reduction of the aldehyde, i.e. a dismutation reaction. At high pH, dismutation is accompanied by a small release of NADH, which is not observed at neutral pH. Previously it has been emphasized that kinetic coefficients obtained by measuring the increase in A340, i.e. the release of NADH at high pH is not a direct measure of the aldehyde oxidation reaction and these values cannot be compared with those for alcohol dehydrogenation. In this article we demonstrate that this is not entirely true, and that the coefficients phiB and phiAB, where B is the aldehyde and A is NAD+, are the same for a dismutation reaction and a simple aldehyde dehydrogenase reaction. Thus the substrate specificity of the aldehyde oxidation reaction can be determined by simply measuring the NADH release. The coefficients for oxidation and dehydrogenation reactions (phi0d and phiAd respectively) are complex and involve the constants for the dismutation reaction. However, dead-end inhibitors can be used to determine the quantitative contribution of the kinetic constants for the aldehyde oxidation and reduction pathways to the phi0d and phiAd coefficients. The combination of dead-end and product inhibitors can be used to determine the reaction mechanism for the aldehyde oxidation pathway. Previously, we showed that with Drosophila Adh, the interconversion between alcohols and aldehydes followed a strictly compulsory ordered pathway, although aldehydes and ketones formed binary complexes with the enzyme. This raised the question regarding the reaction mechanism for the oxidation of aldehydes, i.e. whether a random ordered pathway was followed. In the present work, the mechanism for the oxidation of different aldehydes and the accompanying dismutation reaction with the slow alleloenzyme (AdhS) from Drosophila melanogaster has been studied. To obtain

  10. 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

  11. Two-Carbon Homologation of Ketones to 3-Methyl Unsaturated Aldehydes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The usual scheme of two-carbon homologation of ketones to 3-methyl unsaturated aldehydes by Horner-Wadsworth-Emmons condensations with phosphonate esters, such as triethyl-2-phosphonoacetate, involves three steps. The phosphonate condensation step results in extension of the carbon chain by two carb...

  12. Extremely efficient hydroboration of ketones and aldehydes by copper carbene catalysis.

    PubMed

    Bagherzadeh, Sharareh; Mankad, Neal P

    2016-03-01

    A readily available copper carbene complex, (IPr)CuOtBu, catalyses the hydroboration of ketones and aldehydes even at very low catalyst loadings (0.1 mol%), in some cases with turnover frequencies exceeding 6000 h(-1). Carbonyl reduction occurs selectivitily in the presence of other reducible functional groups including alkenes, nitriles, esters, and alkyl chlorides. PMID:26871503

  13. 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.

  14. 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

  15. Nickel(0)-catalyzed intramolecular reductive coupling of alkenes and aldehydes or ketones with hydrosilanes.

    PubMed

    Hayashi, Yukari; Hoshimoto, Yoichi; Kumar, Ravindra; Ohashi, Masato; Ogoshi, Sensuke

    2016-05-01

    A nickel(0)-catalyzed reductive coupling of aldehydes and simple alkenes with hydrosilanes has been developed. A variety of silyl-protected 1-indanol derivatives were prepared in a highly diastereoselective manner (up to >99 : 1 dr) by employing a combination of nickel(0)/N-heterocyclic carbene and triethylsilane. The present system was also applied to a reductive coupling with ketones. Preliminary results of a nickel(0)-catalyzed asymmetric three-component coupling reaction of an aldehyde, an alkene, and triethylsilane are also shown. PMID:27077829

  16. 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

  17. Integrated quantification and identification of aldehydes and ketones in biological samples.

    PubMed

    Siegel, David; Meinema, Anne C; Permentier, Hjalmar; Hopfgartner, Gérard; Bischoff, Rainer

    2014-05-20

    The identification of unknown compounds remains to be a bottleneck of mass spectrometry (MS)-based metabolomics screening experiments. Here, we present a novel approach which facilitates the identification and quantification of analytes containing aldehyde and ketone groups in biological samples by adding chemical information to MS data. Our strategy is based on rapid autosampler-in-needle-derivatization with p-toluenesulfonylhydrazine (TSH). The resulting TSH-hydrazones are separated by ultrahigh-performance liquid chromatography (UHPLC) and detected by electrospray ionization-quadrupole-time-of-flight (ESI-QqTOF) mass spectrometry using a SWATH (Sequential Window Acquisition of all Theoretical Fragment-Ion Spectra) data-independent high-resolution mass spectrometry (HR-MS) approach. Derivatization makes small, poorly ionizable or retained analytes amenable to reversed phase chromatography and electrospray ionization in both polarities. Negatively charged TSH-hydrazone ions furthermore show a simple and predictable fragmentation pattern upon collision induced dissociation, which enables the chemo-selective screening for unknown aldehydes and ketones via a signature fragment ion (m/z 155.0172). By means of SWATH, targeted and nontargeted application scenarios of the suggested derivatization route are enabled in the frame of a single UHPLC-ESI-QqTOF-HR-MS workflow. The method's ability to simultaneously quantify and identify molecules containing aldehyde and ketone groups is demonstrated using 61 target analytes from various compound classes and a (13)C labeled yeast matrix. The identification of unknowns in biological samples is detailed using the example of indole-3-acetaldehyde. PMID:24745975

  18. Monte Carlo simulations of mixtures involving ketones and aldehydes by a direct bubble pressure calculation.

    PubMed

    Ferrando, Nicolas; Lachet, Véronique; Boutin, Anne

    2010-07-01

    Ketone and aldehyde molecules are involved in a large variety of industrial applications. Because they are mainly present mixed with other compounds, the prediction of phase equilibrium of mixtures involving these classes of molecules is of first interest particularly to design and optimize separation processes. The main goal of this work is to propose a transferable force field for ketones and aldehydes that allows accurate molecular simulations of not only pure compounds but also complex mixtures. The proposed force field is based on the anisotropic united-atoms AUA4 potential developed for hydrocarbons, and it introduces only one new atom, the carbonyl oxygen. The Lennard-Jones parameters of this oxygen atom have been adjusted on saturated thermodynamic properties of both acetone and acetaldehyde. To simulate mixtures, Monte Carlo simulations are carried out in a specific pseudoensemble which allows a direct calculation of the bubble pressure. For polar mixtures involved in this study, we show that this approach is an interesting alternative to classical calculations in the isothermal-isobaric Gibbs ensemble. The pressure-composition diagrams of polar + polar and polar + nonpolar binary mixtures are well reproduced. Mutual solubilities as well as azeotrope location, if present, are accurately predicted without any empirical binary interaction parameters or readjustment. Such result highlights the transferability of the proposed force field, which is an essential feature toward the simulation of complex oxygenated mixtures of industrial interest. PMID:20540589

  19. Intracellular Metabolism of α,β-Unsaturated Carbonyl Compounds, Acrolein, Crotonaldehyde and Methyl Vinyl Ketone, Active Toxicants in Cigarette Smoke: Participation of Glutathione Conjugation Ability and Aldehyde-Ketone Sensitive Reductase Activity.

    PubMed

    Horiyama, Shizuyo; Hatai, Mayuko; Takahashi, Yuta; Date, Sachiko; Masujima, Tsutomu; Honda, Chie; Ichikawa, Atsushi; Yoshikawa, Noriko; Nakamura, Kazuki; Kunitomo, Masaru; Takayama, Mitsuo

    2016-01-01

    The major toxicants in cigarette smoke, α,β-unsaturated aldehydes, such as acrolein (ACR) and crotonaldehyde (CA), and α,β-unsaturated ketone, methyl vinyl ketone (MVK), are known to form Michael-type adducts with glutathione (GSH) and consequently cause intracellular GSH depletion, which is involved in cigarette smoke-induced cytotoxicity. We have previously clarified that exposure to cigarette smoke extract (CSE) of a mouse melanoma cell culture medium causes rapid reduction of intracellular GSH levels, and that the GSH-MVK adduct can be detected by LC/MS analysis while the GSH-CA adduct is hardly detected. In the present study, to clarify why the GSH-CA adduct is difficult to detect in the cell medium, we conducted detailed investigation of the structures of the reaction products of ACR, CA, MVK and CSE in the GSH solution or the cell culture medium. The mass spectra indicated that in the presence of the cells, the GSH-CA and GSH-ACR adducts were almost not detected while their corresponding alcohols were detected. On the other hand, both the GSH-MVK adducts and their reduced products were detected. In the absence of the cells, the reaction of GSH with all α,β-unsaturated carbonyls produced only their corresponding adducts. These results show that the GSH adducts of α,β-unsaturated aldehydes, CA and ACR, are quickly reduced by certain intracellular carbonyl reductase(s) and excreted from the cells, unlike the GSH adduct of α,β-unsaturated ketone, MVK. Such a difference in reactivity to the carbonyl reductase might be related to differences in the cytotoxicity of α,β-unsaturated aldehydes and ketones. PMID:27250793

  20. 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.

  1. 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

  2. Alkylfluorenyl substituted N-heterocyclic carbenes in copper(I) catalysed hydrosilylation of aldehydes and ketones.

    PubMed

    Teci, Matthieu; Lentz, Nicolas; Brenner, Eric; Matt, Dominique; Toupet, Loïc

    2015-08-21

    Copper(i) complexes featuring N-heterocyclic carbenes (NHCs) in which the nitrogen atoms are substituted by a 9-ethyl-9-fluorenyl group (EF) have been synthesised and tested in the hydrosylilation of functionalized and/or sterically demanding ketones and aldehydes. These reactions, carried out with triethylsilane as hydride source, were best achieved with the imidazolylidene copper complex in which the EF substituents can freely rotate about the corresponding N-CEF bonds. The remarkable stability of the active species, which surpasses that of previously reported Cu-NHC catalysts is likely to rely on the ability of the NHC side arms to protect the copper centre during the catalytic cycle by forming sandwich-like intermediates, but also on its steric flexibility facilitating approach of encumbered substrates. TONs up to 1000 were reached. PMID:26162019

  3. 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

  4. Reactions and reaction intermediates on iron surfaces. III. Reactions of aldehydes and ketones on Fe(100)

    SciTech Connect

    Benziger, J.B.; Madix, R.J.

    1982-01-01

    The reactions of formaldehyde, acetaldehyde, and acetone on Fe(100) were studied by temperature-programmed reaction spectroscopy and X-ray photoelectron spectroscopy (XPS). Formaldehyde and acetaldehyde were observed to react with adsorbed hydrogen to form adsorbed alkoxy intermediates. These reactions occurred at low temperature (ca. 200 K). In the absence of adsorbed hydrogen, formaldehyde and acetaldehyde decomposed to adsorbed CO and hydrogen. This reaction was also observed at low temperatures. On an initially clean surface the aldehydes first decomposed, forming adsorbed hydrogen which subsequently reacted with adsorbed aldehyde to form an alkoxy intermediate. The alkoxy intermediates reacted to form CO and H/sub 2/ primarily, with lesser amounts of alcohol, aldehyde, and hydrocarbon products. Acetone reacted differently from the aldehydes and did not appear to form an alkoxy intermediate. XPS results suggested that acetone and acetaldehyde did not adsorb in their keto form on the surface and it is suggested that they adsorbed as enol intermediates. The distinct reaction behavior of acetone may be due to these enol intermediates.

  5. Leaf uptake of methyl ethyl ketone and croton aldehyde by Castanopsis sieboldii and Viburnum odoratissimum saplings

    NASA Astrophysics Data System (ADS)

    Tani, Akira; Tobe, Seita; Shimizu, Sachie

    2013-05-01

    Methyl ethyl ketone (MEK) is an abundant ketone in the urban atmosphere and croton aldehyde (CA) is a strong irritant to eye, nose, and throat. The use of plants able to absorb these compounds is one suggested mitigation method. In order to investigate this method, we determined the uptake rate of these compounds by leaves of two tree species, Castanopsis sieboldii and Viburnum odoratissimum var. awabuki. Using a flow-through chamber method, we found that these species were capable of absorbing both compounds. We also confirmed that the uptake rate of these compounds normalized to the fumigated concentration (AN) was higher at higher light intensities and that there was a linear relationship between AN and stomatal conductance (gS) for both tree species. In concentration-varying experiments, the uptake of MEK and CA seemed to be restricted by partitioning of MEK between leaf water and air. The ratio of the intercellular VOC concentration (Ci) to the fumigated concentration (Ca) for CA was zero, and the ratio ranged from 0.63 to 0.76 for MEK. The more efficient CA uptake ability may be the result of higher partitioning of CA into leaf water. Our present and previous results also suggest that plant MEK uptake ability was different across plant species, depending on the VOC conversion speed inside leaves.

  6. Uncatalyzed Meerwein-Ponndorf-Oppenauer-Verley reduction of aldehydes and ketones under supercritical conditions.

    PubMed

    Sominsky, Lena; Rozental, Esther; Gottlieb, Hugo; Gedanken, Aharon; Hoz, Shmaryahu

    2004-03-01

    When a solution of a carbonyl compound in alcohol (primary or secondary) is heated to ca. 300 degrees C, a disproportionation reaction, in which a carbonyl compound is reduced to the corresponding alcohol and the alcohol is oxidized to the corresponding ketone, takes place. This uncatalyzed variation of the Meerwein-Ponndorf-Oppenauer-Verley reaction gives, in certain cases, e.g., reduction of acetophenone or benzaldehyde by i-PrOH, almost quantitative yields. Yields are higher with secondary alcohols such as i-PrOH than with a primary alcohol such as EtOH. The reactions were also performed in a flow system by passing at a slow rate the same solutions through a glass or a metal coil heated to elevated temperatures. Ab initio calculations performed at the B3LYP/6-31G* level show that thermodynamically i-PrOH is a more potent reducing agent than EtOH by ca. 4 kcal/mol. The computations also show that in cases of aromatic carbonyl compounds, part of the deriving force is obtained from the entropy change of the reaction. The major contributor to the high yield, however, is the excess alcohol used, which shifts the equilibrium to the right. Calculated entropy of activation as well as isotopic H/D labeling suggest a cyclic transition state. PMID:14987002

  7. Stereoretentive Addition of N-tert-Butylsulfonyl-α-Amido Silanes to Aldehydes, Ketones, α,β-Unsaturated Esters, and Imines.

    PubMed

    Mita, Tsuyoshi; Saito, Keisuke; Sugawara, Masumi; Sato, Yoshihiro

    2016-05-20

    Enantioenriched N-tert-butylsulfonyl-α-amido silanes were successfully reacted with aldehydes, ketones, imines, and α,β-unsaturated esters in the presence of a sub-stoichiometric amount of CsF (0.5 equiv) in 1,2-dimethoxyethane (DME) at -20 °C to afford the corresponding coupling products with up to 89 % enantiospecificity in a retentive manner. PMID:27027853

  8. Consideration of reactivity to acute fish toxicity of α,β-unsaturated carbonyl ketones and aldehydes.

    PubMed

    Furuhama, A; Aoki, Y; Shiraishi, H

    2012-01-01

    To understand the key factor for fish toxicity of 11 α,β-unsaturated carbonyl aldehydes and ketones, we used quantum chemical calculations to investigate their Michael reactions with methanethiol or glutathione. We used two reaction schemes, with and without an explicit water molecule (Scheme-1wat and Scheme-0wat, respectively), to account for the effects of a catalytic water molecule on the reaction pathway. We determined the energies of the reactants, transition states (TS), and products, as well as the activation energies of the reactions. The acute fish toxicities of nine of the carbonyl compounds were evaluated to correlate with their hydrophobicities; no correlation was observed for acrolein and crotonaldehyde. The most toxic compound, acrolein, had the lowest activation energy. The activation energy of the reaction could be estimated with Scheme-1wat but not with Scheme-0wat. The complexity of the reaction pathways of the compounds was reflected in the difficulty of the TS structure searches when Scheme-1wat was used with the polarizable continuum model. The theoretical estimations of activation energies of α,β-unsaturated carbonyl compounds with catalytic molecules or groups including hydrogen-bond networks may complement traditional tools for predicting the acute aquatic toxicities of compounds that cannot be easily obtained experimentally. PMID:22150015

  9. Ca(OH)2-Catalyzed Condensation of Aldehydes with Methyl ketones in Dilute Aqueous Ethanol: A Comprehensive Access to α,β-Unsaturated Ketones

    NASA Astrophysics Data System (ADS)

    Yu, Lei; Han, Mengting; Luan, Jie; Xu, Lin; Ding, Yuanhua; Xu, Qing

    2016-07-01

    Cheap, abundant but seldom-employed Ca(OH)2 was found to be an excellent low-loading (5–10 mol%) catalyst for Claisen-Schmidt condensation of aldehydes with methyl ketones under mild conditions. It was interesting that dilute aqueous ethanol (20 v/v%) was unexpectedly discovered to be the optimal solvent. The reaction was scalable at least to 100 mmol and calcium could be precipitated by CO2 and removed by filtration. Evaporation of solvent directly afforded the product in the excellent 96% yield with high purity, as confirmed by its 1H NMR spectrum.

  10. Ca(OH)2-Catalyzed Condensation of Aldehydes with Methyl ketones in Dilute Aqueous Ethanol: A Comprehensive Access to α,β-Unsaturated Ketones

    PubMed Central

    Yu, Lei; Han, Mengting; Luan, Jie; Xu, Lin; Ding, Yuanhua; Xu, Qing

    2016-01-01

    Cheap, abundant but seldom-employed Ca(OH)2 was found to be an excellent low-loading (5–10 mol%) catalyst for Claisen-Schmidt condensation of aldehydes with methyl ketones under mild conditions. It was interesting that dilute aqueous ethanol (20 v/v%) was unexpectedly discovered to be the optimal solvent. The reaction was scalable at least to 100 mmol and calcium could be precipitated by CO2 and removed by filtration. Evaporation of solvent directly afforded the product in the excellent 96% yield with high purity, as confirmed by its 1H NMR spectrum. PMID:27443482

  11. Ca(OH)2-Catalyzed Condensation of Aldehydes with Methyl ketones in Dilute Aqueous Ethanol: A Comprehensive Access to α,β-Unsaturated Ketones.

    PubMed

    Yu, Lei; Han, Mengting; Luan, Jie; Xu, Lin; Ding, Yuanhua; Xu, Qing

    2016-01-01

    Cheap, abundant but seldom-employed Ca(OH)2 was found to be an excellent low-loading (5-10 mol%) catalyst for Claisen-Schmidt condensation of aldehydes with methyl ketones under mild conditions. It was interesting that dilute aqueous ethanol (20 v/v%) was unexpectedly discovered to be the optimal solvent. The reaction was scalable at least to 100 mmol and calcium could be precipitated by CO2 and removed by filtration. Evaporation of solvent directly afforded the product in the excellent 96% yield with high purity, as confirmed by its (1)H NMR spectrum. PMID:27443482

  12. Interstellar Aldehydes and their corresponding Reduced Alcohols: Interstellar Propanol?

    NASA Astrophysics Data System (ADS)

    Etim, Emmanuel; Chakrabarti, Sandip Kumar; Das, Ankan; Gorai, Prasanta; Arunan, Elangannan

    2016-07-01

    There is a well-defined trend of aldehydes and their corresponding reduced alcohols among the known interstellar molecules; methanal (CH_2O) and methanol (CH_3OH); ethenone (C_2H_2O) and vinyl alcohol (CH_2CHOH); ethanal (C_2H_4O) and ethanol(C_2H_5OH); glycolaldehyde (C_2H_4O_2) and ethylene glycol(C_2H_6O_2). The reduced alcohol of propanal (CH_3CH_2CHO) which is propanol (CH_3CH_2CH_2OH) has not yet been observed but its isomer; ethyl methyl ether (CH_3CH_2OCH_3) is a known interstellar molecule. In this article, different studies are carried out in investigating the trend between aldehydes and their corresponding reduced alcohols and the deviation from the trend. Kinetically and with respect to the formation route, alcohols could have been produced from their corresponding reduced aldehydes via two successive hydrogen additions. This is plausible because of (a) the unquestionable high abundance of hydrogen, (b) presence of energy sources within some of the molecular clouds and (c) the ease at which successive hydrogen addition reaction occurs. In terms of stability, the observed alcohols are thermodynamically favorable as compared to their isomers. Regarding the formation process, the hydrogen addition reactions are believed to proceed on the surface of the interstellar grains which leads to the effect of interstellar hydrogen bonding. From the studies, propanol and propan-2-ol are found to be more strongly attached to the surface of the interstellar dust grains which affects its overall gas phase abundance as compared to its isomer ethyl methyl ether which has been observed.

  13. Photooxidation Dynamics of Model Ketones and Alcohols on TiO2(110)

    NASA Astrophysics Data System (ADS)

    Kershis, Matthew; Wilson, Daniel; White, Michael

    2014-03-01

    The photooxidation dynamics of model ketones and alcohols on TiO2(110) were studied using pump-probe laser spectroscopy under UHV conditions. Butanone photooxidation was chosen as a model reaction to demonstrate a fast ion imaging system using pixel imaging mass spectrometry (PImMS). Butanone photooxidation proceeds via ejection of both an ethyl and methyl radical. In the former case, multiple species are observed in product mass spectra which previous studies have shown are the result of ethyl radical fragmentation due to dissociative ionization. Results obtained using this imaging technique agree with previous work and demonstrate the utility of this technique in elucidating fundamental surface photochemical mechanisms. Results from the study of ethanol and isopropanol photooxidation on this surface will also be presented. These results show that methyl radicals are ejected during the photooxidation of these molecules. Comparison of methyl radical final state distributions measured here with those obtained for acetaldehyde and acetone photooxidation indicate that methyl radicals are produced as secondary photoproducts following the photooxidation of the primary aldehyde-ketone photoproducts. Support from U.S. Dept. of Energy, contract DE-AC02-98CH10886.

  14. Alcohol and aldehyde dehydrogenase polymorphisms in Chinese and Indian populations.

    PubMed

    Tan, Ene-Choo; Lim, Leslie; Leong, Jern-Yi; Lim, Jing-Yan; Lee, Arthur; Yang, Jun; Tan, Chay-Hoon; Winslow, Munidasa

    2010-01-01

    The association between two functional polymorphisms in alcohol dehydrogenase (ADH2/ADH1B) and aldehyde dehydrogenase (ALDH2) genes and alcohol dependence was examined in 182 Chinese and Indian patients undergoing treatment for alcohol dependence and 184 screened control subjects from Singapore. All subjects were screened by the Alcohol Use Disorders Identification Test (AUDIT). Patients were also administered the Severity of Alcohol Dependence Questionnaire (SADQ). Polymorphisms were genotyped by allele-specific polymerase chain reaction and selected genotypes confirmed by DNA sequencing or restriction fragment length polymorphism. Our results showed that frequencies of ADH1B*2 and ALDH2*2 were higher in controls compared to alcohol-dependent subjects for both Chinese and Indians. Frequencies of these two alleles were also higher in the 104 Chinese controls compared to the 80 Indian controls. None of the eight Chinese who were homozygous for both protective alleles was alcohol dependent. The higher frequencies of the protective alleles could explain the lower rate of alcohol dependence in Chinese. PMID:20025435

  15. A novel alpha-arylation of ketones, aldehydes, and esters via a photoinduced SN1 reaction through 4-aminophenyl cations.

    PubMed

    Fraboni, Andrea; Fagnoni, Maurizio; Albini, Angelo

    2003-06-13

    4-Aminophenyl cations (expediently generated by photolysis of 4-chloroaniline and its N,N-dimethyl derivative by photolysis in MeCN) added to enamines and gave the corresponding alpha-(4-aminophenyl) ketones in satisfactory yields. The yields of the same ketones were increased when silyl enol ethers were used in the place of enamines. The alpha-arylation of silyl enol ethers of aldehydes occurred with lower yields and only with the N,N-dimethyl derivative. The procedure was successful with ketene silyl acetals giving in a single step a good yield of alpha-(4-aminophenyl)propionic(acetic) esters, known intermediates for the preparation of analgesic compounds. The reaction of the aryl cation with Danishefsky's diene gave the arylated beta-methoxy enone. The method is complementary to the recently developed palladium-catalyzed alpha-arylation and occurs under neutral conditions. PMID:12790595

  16. Iodotrimethylsilane-promoted 1,4-addition of alkynylcopper reagents to {alpha}, {beta}-unsaturated ketones and aldehydes

    SciTech Connect

    Eriksson, M.; Iliefski, T.; Nilsson, M.; Olsson, T.

    1995-12-31

    In the presence of TMSI copper acetylides react with cyclic {alpha},{beta}-enones, some s-trans enones and also to {alpha},{beta}-unsaturated aldehydes to give {gamma},{delta}-acetylenic ketones via the silyl enol ethers. Conjugate addition of alkyl and alkenyl copper reagents is a very useful method for the formation of carbon-carbon bonds. However, the conjugate addition of alkynyl copper compounds has so far remained a difficult task. Other methods based on organometallic reagents derived from aluminium, boron, and zinc have been reported. This is the first example of conjugate addition with copper acetylides to {alpha},{beta}-unsaturated carbonyl compounds.

  17. Efficient Hydrogenation of Ketones and Aldehydes Catalyzed by Well-Defined Iron(II) PNP Pincer Complexes: Evidence for an Insertion Mechanism

    PubMed Central

    2014-01-01

    We have prepared and structurally characterized a new class of Fe(II) PNP pincer hydride complexes [Fe(PNP-iPr)(H)(CO)(L)]n (L = Br–, CH3CN, pyridine, PMe3, SCN–, CO, BH4–; n = 0, +1) based on the 2,6-diaminopyridine scaffold where the PiPr2 moieties of the PNP ligand are connected to the pyridine ring via NH and/or NMe spacers. Complexes [Fe(PNP-iPr)(H)(CO)(L)]n with labile ligands (L = Br–, CH3CN, BH4–) and NH spacers are efficient catalysts for the hydrogenation of both ketones and aldehydes to alcohols under mild conditions, while those containing inert ligands (L = pyridine, PMe3, SCN–, CO) are catalytically inactive. Interestingly, complex [Fe(PNPMe-iPr)(H)(CO)(Br)], featuring NMe spacers, is an efficient catalyst for the chemoselective hydrogenation of aldehydes. The first type of complexes involves deprotonation of the PNP ligand as well as heterolytic dihydrogen cleavage via metal-alkoxide cooperation, but no reversible aromatization/deprotonation of the PNP ligand. In the case of the N-methylated complex the mechanism remains unclear, but obviously does not allow bifunctional activation of dihydrogen. The experimental results complemented by DFT calculations strongly support an insertion of the C=O bond of the carbonyl compound into the Fe–H bond.

  18. (16) O/(18) O Exchange of Aldehydes and Ketones caused by H2 (18) O in the Mechanistic Investigation of Organocatalyzed Michael, Mannich, and Aldol Reactions.

    PubMed

    Hayashi, Yujiro; Mukaiyama, Takasuke; Benohoud, Meryem; Gupta, Nishant R; Ono, Tsuyoshi; Toda, Shunsuke

    2016-04-18

    Organocatalyzed Michael, Mannich, and aldol reactions of aldehydes or ketones, as nucleophiles, have triggered several discussions regarding their reaction mechanism. H2 (18) O has been utilized to determine if the reaction proceeds through an enamine or enol mechanism by monitoring the ratio of (18) O incorporated into the final product. In this communication, we describe the risk of H2 (18) O as an evaluation tool for this mechanistic investigation. We have demonstrated that exchange of (16) O/(18) O occurs in the aldehyde or ketone starting material, caused by the presence of H2 (18) O and amine catalysts, before the Michael, Mannich, and aldol reactions proceed. Because the newly generated (18) O starting aldehydes or ketones and (16) O water affect the incorporation ratio of (18) O in the final product, the use of H2 (18) O would not be appropriate to distinguish the mechanism of these organocatalyzed reactions. PMID:26841358

  19. Lanthanide anilido complexes: synthesis, characterization, and use as highly efficient catalysts for hydrophosphonylation of aldehydes and unactivated ketones.

    PubMed

    Liu, Chengwei; Qian, Qinqin; Nie, Kun; Wang, Yaorong; Shen, Qi; Yuan, Dan; Yao, Yingming

    2014-06-14

    Lanthanide anilido complexes stabilized by the 2,6-diisopropylanilido ligand have been synthesized and characterized, and their catalytic activity for hydrophosphonylation reaction was explored. A reaction of anhydrous LnCl3 with 5 equivalents of LiNHPh-(I)Pr2-2,6 in THF generated the heterobimetallic lanthanide-lithium anilido complexes (2,6-(I)Pr2PhNH)5LnLi2(THF)2 [Ln = Sm(1), Nd(2), Y(3)] in good isolated yields. These complexes are well characterized by elemental analysis, IR, NMR (for complex ) and single-crystal structure determination. Complexes 1 - 3 are isostructural. In these complexes, the lanthanide metal ion is five-coordinated by five nitrogen atoms from five 2,6-diisopropylanilido ligands to form a distorted trigonal bipyramidal geometry. The lithium ion is coordinated by two nitrogen atoms from two 2,6-diisopropylanilido ligands, and one oxygen atom from a THF molecule. It was found that these simple lanthanide anilido complexes are highly efficient for catalyzing hydrophosphonylation reactions of various aldehydes and unactivated ketones to generate α-hydroxyphosphonates in good to excellent yields (up to 99%) within a short time (5 min for aldehydes, 20 min for ketones). Furthermore, the mechanism of hydrophosphonylation reactions has also been elucidated via(1)H NMR monitoring of reaction. PMID:24728525

  20. Synthesis of Ketones through Microwave Irradiation Promoted Metal-Free Alkylation of Aldehydes by Activation of C(sp(3))-H Bond.

    PubMed

    Zhang, Xinying; Wang, Zhangxin; Fan, Xuesen; Wang, Jianji

    2015-11-01

    In this paper, a novel methodology for the synthesis of ketones via microwave irradiation promoted direct alkylation of aldehydes by activation of the inert C(sp(3))-H bond has been developed. Notably, the reactions were accomplished under metal-free conditions and used commercially available aldehydes and cycloalkanes as substrates without prefunctionalization. By using this novel method, an alternative synthetic approach toward the key intermediates for the preparation of the pharmaceutically valuable oxaspiroketone derivatives was successfully established. PMID:26457376

  1. Chemistry of enol ethers. LXXXIV. Condensation of acetals of saturated aldehydes with 2-trimethylsilyloxy-1,3-dienes. Synthesis of /beta/-alkoxy-alkyl vinyl and divinyl ketones

    SciTech Connect

    Makin, S.M.; Nazarova, O.N.; Dymshakova, G.M.; Kundryutskova, L.A.

    1988-11-10

    The addition of the acetals of saturated aldehydes (formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, and isobutyraldehyde) to 2-trimethylsilyloxy-4-methyl-1,3-pentadiene in the presence of aprotic acids (ZnCl/sub 2/, ZnBr/sub 2/, FeCl/sub 3/, SnCl/sub 4/, BF/sub 3/ /times/ OEt/sub 2/) takes place at positions 1, 2 of the diene system with the formation of /beta/-alkoxyalkyl vinyl ketones. The most effective catalysts of this reaction were stannic chloride and zinc bromide. The alkyl derivatives of divinyl ketones are formed when the obtained /beta/-alkoxyalkyl vinyl ketones are heated with p-toluenesulfonic acid.

  2. Direct Aerobic α, β-Dehydrogenation of Aldehydes and Ketones with a Pd(TFA)(2)/4,5-Diazafluorenone Catalyst().

    PubMed

    Diao, Tianning; Wadzinski, Tyler J; Stahl, Shannon S

    2012-01-01

    The direct α, β-dehydrogenation of aldehydes and ketones represents an efficient alternative to stepwise methods to prepare enal and enone products. Here, we describe a new Pd(TFA)(2)/4,5-diazafluorenone dehydrogenation catalyst that overcomes key limitations of previous catalyst systems. The scope includes successful reactivity with pharmaceutically important cyclopentanone and flavanone substrates, as well as acyclic ketones. Preliminary mechanistic studies compare the reactivity of this catalyst to previously reported dehydrogenation catalysts and reveal that cleavage of the α-C-H bond of the ketone is the turnover-limiting step of the catalytic mechanism. PMID:22690316

  3. Direct Aerobic α, β-Dehydrogenation of Aldehydes and Ketones with a Pd(TFA)2/4,5-Diazafluorenone Catalyst†

    PubMed Central

    Diao, Tianning; Wadzinski, Tyler J.; Stahl, Shannon S.

    2011-01-01

    The direct α, β-dehydrogenation of aldehydes and ketones represents an efficient alternative to stepwise methods to prepare enal and enone products. Here, we describe a new Pd(TFA)2/4,5-diazafluorenone dehydrogenation catalyst that overcomes key limitations of previous catalyst systems. The scope includes successful reactivity with pharmaceutically important cyclopentanone and flavanone substrates, as well as acyclic ketones. Preliminary mechanistic studies compare the reactivity of this catalyst to previously reported dehydrogenation catalysts and reveal that cleavage of the α-C–H bond of the ketone is the turnover-limiting step of the catalytic mechanism. PMID:22690316

  4. Cu-NHC-TEMPO catalyzed aerobic oxidation of primary alcohols to aldehydes.

    PubMed

    Liu, Xiaolong; Xia, Qinqin; Zhang, Yuejiao; Chen, Congyan; Chen, Wanzhi

    2013-09-01

    Imidazolium salts bearing TEMPO groups react with commercially available copper powder affording Cu-NHC complexes. The in situ generated Cu-NHC-TEMPO complexes are quite efficient catalysts for aerobic oxidation of primary alcohols into aldehydes. The catalyst is easily available, and various primary alcohols were selectively converted to aldehydes in excellent yields. PMID:23944937

  5. C-Alkylation of Ketones and Related Compounds by Alcohols: Transition-Metal-Catalyzed Dehydrogenation.

    PubMed

    Huang, Fei; Liu, Zhuqing; Yu, Zhengkun

    2016-01-18

    Transition-metal-catalyzed C-alkylation of ketones and secondary alcohols, with alcohols, avoids use of organometallic or environmentally unfriendly alkylating agents by means of borrowing hydrogen (BH) or hydrogen autotransfer (HA) activation of the alcohol substrates. Water is formed as the only by-product, thus making the BH process atom-economical and environmentally benign. Diverse homogeneous and heterogeneous transition-metal catalysts, ketones, and alcohols can be used for this transformation, thus rendering the BH process promising for replacing those procedures that use traditional alkylating agents. This Minireview summarizes the advances during the last five years in transition-metal-catalyzed BH α-alkylation of ketones, and β-alkylation of secondary alcohols with alcohols. A discussion on the application of the BH strategy for C-C bond formation is included. PMID:26639633

  6. Synthesis and Characterization of Aldol Condensation Products from Unknown Aldehydes and Ketones: An Inquiry-Based Experiment in the Undergraduate Laboratory

    ERIC Educational Resources Information Center

    Angelo, Nicholas G.; Henchey, Laura K.; Waxman, Adam J.; Canary, James W.; Arora, Paramjit S.; Wink, Donald

    2007-01-01

    An experiment for the undergraduate chemistry laboratory in which students perform the aldol condensation on an unknown aldehyde and an unknown ketone is described. The experiment involves the use of techniques such as TLC, column chromatography, and recrystallization, and compounds are characterized by [to the first power]H NMR, GC-MS, and FTIR.…

  7. Mild Deoxygenation of Aromatic Ketones and Aldehydes over Pd/C Using Polymethylhydrosiloxane as the Reducing Agent**

    PubMed Central

    Volkov, Alexey; Gustafson, Karl P J; Tai, Cheuk-Wai; Verho, Oscar; Bäckvall, Jan-E; Adolfsson, Hans

    2015-01-01

    Herein, a practical and mild method for the deoxygenation of a wide range of benzylic aldehydes and ketones is described, which utilizes heterogeneous Pd/C as the catalyst together with the green hydride source, polymethylhydrosiloxane. The developed catalytic protocol is scalable and robust, as exemplified by the deoxygenation of ethyl vanillin, which was performed on a 30 mmol scale in an open-to-air setup using only 0.085 mol % Pd/C catalyst to furnish the corresponding deoxygenated product in 93 % yield within 3 hours at room temperature. Furthermore, the Pd/C catalyst was shown to be recyclable up to 6 times without any observable decrease in efficiency and it exhibited low metal leaching under the reaction conditions. PMID:25728614

  8. 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

  9. Control of aldehyde emissions in the diesel engines with alcoholic fuels.

    PubMed

    Krishna, M V S Murali; Varaprasad, C M; Reddy, C Venkata Ramana

    2006-01-01

    The major pollutants emitted from compression ignition (CI) engine with diesel as fuel are smoke and nitrogen oxides (NOx). When the diesel engine is run with alternate fuels, there is need to check alcohols (methanol or ethanol) and aldehydes also. Alcohols cannot be used directly in diesel engine and hence engine modification is essential as alcohols have low cetane number and high latent hear of vaporization. Hence, for use of alcohol in diesel engine, it needs hot combustion chamber, which is provided by low heat rejection (LHR) diesel engine with an air gap insulated piston with superni crown and air gap insulated liner with superni insert. In the present study, the pollution levels of aldehydes are reported with the use of methanol and ethanol as alternate fuels in LHR diesel engine with varying injection pressure, injection timings with different percentage of alcohol induction. The aldehydes (formaldehyde and acetaldehyde) in the exhaust were estimated by wet chemical technique with high performance liquid chromatograph (HPLC). Aldehyde emissions increased with an increase in alcohol induction. The LHR engine showed a decrease in aldehyde emissions when compared to conventional engine. However, the variation of injection pressure showed a marginal effect in reducing aldehydes, while advancing the injection timing reduced aldehyde emissions. PMID:17913204

  10. Me2(CH2Cl)SiCN: Bifunctional Cyanating Reagent for the Synthesis of Tertiary Alcohols with a Chloromethyl Ketone Moiety via Ketone Cyanosilylation.

    PubMed

    Zeng, Xing-Ping; Zhou, Jian

    2016-07-20

    We report a novel bifunctional cyanating reagent, Me2(CH2Cl)SiCN, which paves the way to a one-pot sequential synthesis of tertiary alcohols featuring a chloromethyl ketone moiety via enantioselective ketone cyanosilylation. This method contributes to gram-scale enantioselective total synthesis of the aggregation pheromone of the Colorado potato beetle, (S)-CPB. PMID:27399262

  11. Enolizable Carbonyls and N,O-Acetals: A Rational Approach for Room-Temperature Lewis Superacid-Catalyzed Direct α-Amidoalkylation of Ketones and Aldehydes.

    PubMed

    Touati, Bahria; El Bouakher, Abderrahman; Taillier, Catherine; Othman, Raja Ben; Trabelsi-Ayadi, Malika; Antoniotti, Sylvain; Duñach, Elisabet; Dalla, Vincent

    2016-04-18

    An efficient catalytic room-temperature direct α-amidoalkylation of carbonyl donors, that is, ketones and aldehydes with unbiased N,O-acetals, is described. Sn(NTf2 )4 is an optimal catalyst to promote this challenging transformation at low loading and the reaction shows promising scope. A comprehensive and rational evaluation of this reaction has led to the establishment of an empirical scale of nucleophilic reactivity for a broad set of ketones that should be helpful in the synthetic design and development of carbonyl α-functionalization methods. PMID:26992138

  12. Formal [4+2] cycloaddition of di-tert-butyl 2-ethoxycyclobutane-1,1-dicarboxylate with ketones or aldehydes and tandem lactonization.

    PubMed

    Okado, Ryohei; Nowaki, Aya; Matsuo, Jun-Ichi; Ishibashi, Hiroyuki

    2012-01-01

    A catalytic amount of tin(IV) chloride catalyzed formal [4+2] cycloaddition reaction of di-tert-butyl 2-ethoxycyclobutane-1,1-carboxylate with ketones or aldehydes to give diethyl 6-ethoxydihydro-2H-pyran-3,3(4H)-dicarboxylates, whereas two equivalents of trimethylsilyl triflate promoted tandem [4+2] cycloaddition and lactonization to afford 3-oxo-2,6-dioxabicyclo[2.2.2]octane-4-carboxylate esters. PMID:22223370

  13. Extraction and Quantitation of Ketones and Aldehydes from Mammalian Cells Using Fluorous Tagging and Capillary LC-MS.

    PubMed

    Yuan, Wei; Li, Shuwei; Edwards, James L

    2015-08-01

    The extraction and quantitation of carbonyl metabolites from cell lysate was accomplished using a carbonyl-reactive fluorous tag and capillary liquid chromatography coupled to mass spectrometry (capLC-MS). Selective fluorous tagging for ketones and aldehydes provided a 30-fold increase in sensitivity using electrospray ionization MS. Separation of fluorous tagged carbonyl resulted in good separation of all components, and tandem MS was able to differentiate structural carbonyl isomers. The average limit of detection for carbonyl standards was 37 nM (range 1.5-250 nM), with linearity of R(2) > 0.99. Reproducibility for metabolites in cell lysate averaged 9% RSD. Human aortic endothelial cells (HAECs) were exposed to varying levels of glucose, and their carbonyl metabolite levels were quantified. Significant metabolite changes were seen in glycolysis and the propanoate pathway from a glucose challenge. Using an untargeted approach, 120 carbonyl metabolites were found to change in hyperglycemic HAECs. From this list of compounds, multiple metabolites from the pentose phosphate and tryptophan metabolic pathways were discovered. This system provides excellent sensitivity and quantitation of carbonyl metabolites without the need for isotope standards or labels. PMID:26114225

  14. Bifunctional aldehyde/alcohol dehydrogenase (ADHE) in chlorophyte algal mitochondria.

    PubMed

    Atteia, Ariane; van Lis, Robert; Mendoza-Hernández, Guillermo; Henze, Katrin; Martin, William; Riveros-Rosas, Hector; González-Halphen, Diego

    2003-09-01

    Protein profiles of mitochondria isolated from the heterotrophic chlorophyte Polytomella sp. grown on ethanol at pH 6.0 and pH 3.7 were analyzed by Blue Native and denaturing polyacrylamide gel electrophoresis. Steady-state levels of oxidative phosphorylation complexes were influenced by external pH. Levels of an abundant, soluble, mitochondrial protein of 85 kDa and its corresponding mRNA increased at pH 6.0 relative to pH 3.7. N-terminal and internal sequencing of the 85 kDa mitochondrial protein together with the corresponding cDNA identified it as a bifunctional aldehyde/alcohol dehydrogenase (ADHE) with strong similarity to homologues from eubacteria and amitochondriate protists. A mitochondrial targeting sequence of 27 amino acids precedes the N-terminus of the mature mitochondrial protein. A gene encoding an ADHE homologue was also identified in the genome of Chlamydomonas reinhardtii, a photosynthetic relative of Polytomella. ADHE reveals a complex picture of sequence similarity among homologues. The lack of ADHE from archaebacteria indicates a eubacterial origin for the eukaryotic enzyme. Among eukaryotes, ADHE has hitherto been characteristic of anaerobes since it is essential to cytosolic energy metabolism of amitochondriate protists such as Giardia intestinalis and Entamoeba histolytica. Its abundance and expression pattern suggest an important role for ADHE in mitochondrial metabolism of Polytomella under the conditions studied. The current data are compatible with the view that Polytomella ADHE could be involved either in ethanol production or assimilation, or both, depending upon environmental conditions. Presence of ADHE in an oxygen-respiring algal mitochondrion and co-expression at ambient oxygen levels with respiratory chain components is unexpected with respect to the view that eukaryotes acquired ADHE genes specifically as an adaptation to an anaerobic lifestyle. PMID:14756315

  15. Oxidation of cinnamyl alcohols and aldehydes by a basic peroxidase from lignifying Zinnia elegans hypocotyls.

    PubMed

    Barceló, A R; Pomar, F

    2001-08-01

    The xylem of 26-day old Zinnia elegans hypocotyls synthesizes lignins derived from coniferyl alcohol and sinapyl alcohol with a G/S ratio of 43/57 in the aryl-glycerol-beta-aryl ether core, as revealed by thioacidolysis. Thioacidolysis of Z. elegans lignins also reveals the presence of coniferyl aldehyde end groups linked by beta-0-4 bonds. Both coniferyl and sinapyl alcohols, as well as coniferyl and sinapyl aldehyde, are substrates of a xylem cell wall-located strongly basic peroxidase, which is capable of oxidizing them in the absence and in the presence of hydrogen peroxide. This peroxidase shows a particular affinity for cinnamyl aldehydes with kappa(M) values in the mu(M) range, and some specificity for syringyl-type phenols. The affinity of this strongly basic peroxidase for cinnamyl alcohols and aldehydes is similar to that shown by the preceding enzymes in the lignin biosynthetic pathway (microsomal 5-hydroxylases and cinnamyl alcohol dehydrogenase), which also use cinnamyl alcohols and aldehydes as substrates, indicating that the one-way highway of construction of the lignin macromolecule has no metabolic "potholes" in which the lignin building blocks might accumulate. This fact suggests a high degree of metabolic plasticity for this basic peroxidase, which has been widely conserved during the evolution of vascular plants, making it one of the driving forces in the evolution of plant lignin heterogeneity. PMID:11430983

  16. Highly enantioselective Henry reactions of aromatic aldehydes catalyzed by an amino alcohol-copper(II) complex.

    PubMed

    Qin, Dan-Dan; Lai, Wen-Han; Hu, Di; Chen, Zheng; Wu, An-An; Ruan, Yuan-Ping; Zhou, Zhao-Hui; Chen, Hong-Bin

    2012-08-20

    Amino alcohol-Cu(II) catalyst: Highly enantioselective Henry reactions between aromatic aldehydes and nitromethane have been developed. The reactions were catalyzed by an easily available and operationally simple amino alcohol-copper(II) catalyst. In total, 38 substrates were tested and the R-configured products were obtained in good yields with excellent enantioselectivities. PMID:22791567

  17. [Experimental research on alcohols, aldehydes, aromatic hydrocarbons and olefins emissions from alcohols fuelled vehicles].

    PubMed

    Zhang, Fan; Wang, Jian-Hai; Wang, Xiao-Cheng; Wang, Jian-Xin

    2013-07-01

    Using two vehicles fuelled with pure gasoline, M15, M30 and pure gasoline, E10, E20 separately, 25 degrees C normal temperature type I emission test, -7 degrees C low temperature type VI emission test and type IV evaporation emission test were carried out. FTIR, HPLC and GC-MS methods were utilized to measure alcohols, aldehydes, aromatic hydrocarbons and olefins emissions. The test results indicate that at the low as well as normal ambient temperature, as the alcohols proportion increasing in the fuel, unburned methanol, formaldehyde, acetaldehyde increase proportionally, benzene, toluene, ethylene, propylene, 1,3-butadiene and isobutene decrease slightly. The unregulated emissions at the low ambient temperature are significantly higher than those at the normal ambient temperature. The difference of HC emissions in the entire process of evaporative emission tests of E10, gasoline and M15 fuels is slight. There is a small difference of unregulated emissions in the diurnal test of three fuels. PMID:24027980

  18. Asymmetric reduction of prochiral ketones to chiral alcohols catalyzed by plants tissue.

    PubMed

    Yang, Zhong-Hua; Zeng, Rong; Yang, Gai; Wang, Yu; Li, Li-Zhen; Lv, Zao-Sheng; Yao, Man; Lai, Bin

    2008-09-01

    As an important organic compound, chiral alcohols are the key chiral building blocks to many single enantiomer pharmaceuticals. Asymmetric reduction of the corresponding prochiral ketones to produce the chiral alcohols by biocatalysis is one of the most promising routes. Asymmetric reduction of different kinds of non-natural prochiral ketones catalyzed by various plants tissue was studied in this work. Acetophenone, 4'-chloroacetophenone and ethyl 4-chloroacetoacetate were chosen as the model substrates for simple ketone, halogen-containing aromatic ketone and beta-ketoesters, respectively. Apple (Malus pumila), carrot (Daucus carota), cucumber (Cucumis sativus), onion (Allium cepa), potato (Soanum tuberosum), radish (Raphanus sativus) and sweet potato (Ipomoea batatas) were chosen as the biocatalysts. It was found that these kinds of prochiral ketoness could be reduced by these plants tissue with high enantioselectivity. Both R- and S-form configuration chiral alcohols could be obtained. The e.e. and chemical yield could reach about 98 and 80% respectively for acetophenone and 4'-chloroacetophenone reduction reaction with favorable plant tissue. And the e.e. and yield for ethyl 4-chloroacetoacetate reduction reaction was about 91 and 45% respectively. PMID:18548304

  19. Inhibitory effects of terpene alcohols and aldehydes on growth of green alga Chlorella pyrenoidosa

    SciTech Connect

    Ikawa, Miyoshi; Mosley, S.P.; Barbero, L.J. )

    1992-10-01

    The growth of the green alga Chlorella pyrenoidosa was inhibited by terpene alcohols and the terpene aldehyde citral. The strongest activity was shown by citral. Nerol, geraniol, and citronellol also showed pronounced activity. Strong inhibition was linked to acyclic terpenes containing a primary alcohol or aldehyde function. Inhibition appeared to be taking place through the vapor phase rather than by diffusion through the agar medium from the terpene-treated paper disks used in the system. Inhibition through agar diffusion was shown by certain aged samples of terpene hydrocarbons but not by recently purchased samples.

  20. [Analysis of aliphatic aldehydes and ketones in water-based adhesive by direct derivatization-ionic liquid gathering coupled with high performance liquid chromatography].

    PubMed

    Wan, Xiaohong; Wu, Mingjian; Jiang, Xinyu; Dai, Yunhui; Li, Shaoye; Gong, Shuguo

    2011-12-01

    A novel method was developed for trace analysis of aliphatic aldehydes and ketones in water-based adhesive based on 2,4-dinitrophenylhydrazine (DNPH) direct derivatization-1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM] PF6) preconcentration coupled with high performance liquid chromatography (HPLC). The dispersive water-based adhesive emulsion directly reacted with 80 mg/L DNPH solution containing 0.44 mol/L phosphoric acid at 40 degrees C for 18 min. After centrifuging, 0.5 mL [BMIM] PF6 was added to extract the derivatives at 30 degrees C. The ionic liquid (IL) phase was filtered and then analyzed by HPLC. The separation was achieved by using a Dionex Acclaim Explosive E2 column (250 mm x 4.6 mm, 5 microm) under the gradient elution with acetonitrile and water as mobile phases at the flow rate of 1.2 mL/min. The column temperature was 35 degrees C, and the detection wavelength was 365 nm. The results showed that the limits of detection (LODs) were 0.022 -0.221 mg/kg, and the limits of quantification (LOQs) were 0.073 - 0.738 mg/kg. The relative standard deviations (RSDs) were in the range of 3.5% - 7.3%, and the recoveries were 84.0% - 102.5% for 8 aliphatic aldehydes and ketones. Compared with solvent extraction, the established method has the advantages of lower LOD and LOQ, and is more stable and precise. This method is practical for the determination of aliphatic aldehydes and ketones in water-based adhesives. PMID:22500444

  1. Copper-catalyzed retro-aldol reaction of β-hydroxy ketones or nitriles with aldehydes: chemo- and stereoselective access to (E)-enones and (E)-acrylonitriles.

    PubMed

    Zhang, Song-Lin; Deng, Zhu-Qin

    2016-07-26

    A copper-catalyzed transfer aldol type reaction of β-hydroxy ketones or nitriles with aldehydes is reported, which enables chemo- and stereoselective access to (E)-α,β-unsaturated ketones and (E)-acrylonitriles. A key step of the in situ copper(i)-promoted retro-aldol reaction of β-hydroxy ketones or nitriles is proposed to generate a reactive Cu(i) enolate or cyanomethyl intermediate, which undergoes ensuing aldol condensation with aldehydes to deliver the products. This reaction uses 1.2 mol% Cu(IPr)Cl (IPr denotes 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene) as the catalyst in the presence of 6.0 mol% NaOtBu cocatalyst at room temperature or 70 °C. A range of aryl and heteroaryl aldehydes as well as acrylaldehydes are compatible with many useful functional groups being tolerated. Under the mild and weakly basic conditions, competitive Cannizzaro-type reaction of benzaldehydes and side reactions of base-sensitive functional groups can be effectively suppressed, which show synthetic advantages of this reaction compared to classic aldol reactions. The synthetic potential of this reaction is further demonstrated by the one-step synthesis of biologically active quinolines and 1,8-naphthyridine in excellent yields (up to 91%). Finally, a full catalytic cycle for this reaction has been constructed using DFT computational studies in the context of a retro-aldol/aldol two-stage mechanism. A rather flat reaction energy profile is found indicating that both stages are kinetically facile, which is consistent with the mild reaction conditions. PMID:27397647

  2. Reductive coupling of phthalimides with ketones and aldehydes by low-valent titanium: one-pot synthesis of alkylideneisoindolin-1-ones.

    PubMed

    Kise, Naoki; Kawano, Yusuke; Sakurai, Toshihiko

    2013-12-20

    The reductive coupling of phthalimides with ketones and aldehydes by Zn-TiCl4 in THF gave two- and four-electron reduced products, 3-hydroxy-3-(1-hydroxyalkyl)isoindolin-1-ones and alkylideneisoindolin-1-ones, selectively by controlling the reaction conditions. Therefore, the one-pot synthesis of alkylideneisoindolin-1-ones from phthalimides was effected by this reaction. Although the alkylideneisoindolin-1-ones prepared from phthalimides and aldehydes were formed as mixtures of geometric isomers in most cases, the geometric ratios could be increased by reflux in cat. PPTS/toluene. After the isomerization, the E-isomers of N-methyl substituted alkylideneisoindolin-1-ones (X = Me, R(1) = R, R(2) = H) and the Z-isomers of N-unsubstituted alkylideneisoindolin-1-ones (X = H, R(1) = H, R(2) = R) were obtained preferentially. PMID:24266907

  3. Selective deoxygenation of aldehydes and alcohols on molybdenum carbide (Mo2C) surfaces

    NASA Astrophysics Data System (ADS)

    Xiong, Ke; Yu, Weiting; Chen, Jingguang G.

    2014-12-01

    The selective deoxygenation of aldehydes and alcohols without cleaving the Csbnd C bond is crucial for upgrading bio-oil and other biomass-derived molecules to useful fuels and chemicals. In this work, propanal, 1-propanol, furfural and furfuryl alcohol were selected as probe molecules to study the deoxygenation of aldehydes and alcohols on molybdenum carbide (Mo2C) prepared over a Mo(1 1 0) surface. The reaction pathways were investigated using temperature programmed desorption (TPD) and high resolution electron energy loss spectroscopy (HREELS). The deoxygenation of propanal and 1-propanol went through a similar intermediate (propoxide or η2(C,O)-propanal) to produce propene. The deoxygenation of furfural and furfuryl alcohol produced a surface intermediate similar to adsorbed 2-methylfuran. The comparison of these results revealed the promising deoxygenation performance of Mo2C, as well as the effect of the furan ring on the selective deoxygenation of the Cdbnd O and Csbnd OH bonds.

  4. The Stereoselective Reductions of Ketones to the Most Thermodynamically Stable Alcohols Using Lithium and Hydrated Salts of Common Transition Metals.

    PubMed

    Kennedy, Nicole; Cohen, Theodore

    2015-08-21

    A simple method is presented for the highly stereoselective reductions of ketones to the most thermodynamically stable alcohols. In this procedure, the ketone is treated with lithium dispersion and either FeCl2·4H2O or CuCl2·2H2O in THF at room temperature. This protocol is applied to a large number and variety of ketones and is both more convenient and efficient than those commonly reported for the diastereoselective reduction of five- and six-membered cyclic ketones. PMID:26226182

  5. Iridium-Catalyzed Allylation of Chiral β-Stereogenic Alcohols: Bypassing Discrete Formation of Epimerizable Aldehydes

    PubMed Central

    Schmitt, Daniel C.; Dechert-Schmitt, Anne-Marie R.; Krische, Michael J.

    2012-01-01

    The cyclometallated π-allyliridium 3,4-dinitro-C,O-benzoate complex modified by (R)- or (S)-Cl,MeO-BIPHEP promotes the transfer hydrogenative coupling of allyl acetate to β-stereogenic alcohols with good to excellent levels of catalyst-directed diastereoselectivity to furnish homoallylic alcohols. Remote electronic effects of the C,O-benzoate of the catalyst play a critical role in suppressing epimerization of the transient α-stereogenic aldehyde. PMID:23231774

  6. STRUCTURE TOXICITY IN RELATIONSHIPS FOR A,B-UNSATURATED ALCOHOLS IN FISH

    EPA Science Inventory

    Previous toxicity testing with fathead minnows (Pimephales promelas) indicated that some unsaturated acetylenic and allylic alcohols can be metabolically activated, via alcohol dehydrogenase, to highly toxic a,B-unsaturated aldehydes and ketones or allene derivatives. lthough sev...

  7. Ketone-alcohol hydrogen-transfer equilibria: is the biooxidation of halohydrins blocked?

    PubMed

    Bisogno, Fabricio R; García-Urdiales, Eduardo; Valdés, Haydee; Lavandera, Iván; Kroutil, Wolfgang; Suárez, Dimas; Gotor, Vicente

    2010-09-24

    To ensure the quasi-irreversibility of the oxidation of alcohols coupled with the reduction of ketones in a hydrogen-transfer (HT) fashion, stoichiometric amounts of α-halo carbonyl compounds have been employed as hydrogen acceptors. The reason that these substrates lead to quasi-quantitative conversions has been tacitly attributed to both thermodynamic and kinetic effects. To provide a clear rationale for this behavior, we investigate herein the redox equilibrium of a selected series of ketones and 2-propanol by undertaking a study that combines experimental and theoretical approaches. First, the activity of the (R)-specific alcohol dehydrogenase from Lactobacillus brevis (LBADH) with these substrates was studied. The docking of acetophenone/(R)-1-phenyethanol and α-chloroacetophenone/(S)-2-chloro-1-phenylethanol in the active site of the enzyme confirms that there seems to be no structural reason for the lack of reactivity of halohydrins. This assumption is confirmed by the fact that the corresponding aluminum-catalyzed Meerwein-Ponndorf-Verley-Oppenauer (MPVO) reactions afford similar conversions to those obtained with LBADH, showing that the observed reactivity is independent of the catalyst employed. While the initial rates of the enzymatic reductions and the IR ν(C=O) values contradict the general belief that electron-withdrawing groups increase the electrophilicity of the carbonyl group, the calculated ΔG values of the isodesmic redox transformations of these series of ketones/alcohols with 2-propanol/acetone support the thermodynamic control of the reaction. As a result, a general method to predict the degree of conversion obtained in the HT-reduction process of a given ketone based on the IR absorption band of the carbonyl group is proposed, and a strategy to achieve the HT oxidation of halohydrins is also shown. PMID:20803580

  8. 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

  9. RESEARCH NOTE: INTERFERENCES DUE TO OZONE-SCAVENGING REAGENTS IN THE GC-ECD DETERMINATION OF ALDEHYDES AND KETONS AS THE O-(2,3,4,5,6-PENTAFLUOROBENZYL)OXIMES

    EPA Science Inventory

    Six potential ozone-scavenging reagents were tested for possible interference in the GC-ECD determination of aldehydes and ketones after derivatization with O-(2,3,4,5,6-pentafluorobenzyl)oxylamine (PFBOA). All six-nitrite, cynaide, methanoate (formate), indigo-55'-disulfonate d...

  10. Asymmetric cyanation of aldehydes, ketones, aldimines, and ketimines catalyzed by a versatile catalyst generated from cinchona alkaloid, achiral substituted 2,2'-biphenol and tetraisopropyl titanate.

    PubMed

    Wang, Jun; Wang, Wentao; Li, Wei; Hu, Xiaolei; Shen, Ke; Tan, Cheng; Liu, Xiaohua; Feng, Xiaoming

    2009-11-01

    Full investigation of cyanation of aldehydes, ketones, aldimines and ketimines with trimethylsilyl cyanide (TMSCN) or ethyl cyanoformate (CNCOOEt) as the cyanide source has been accomplished by employing an in situ generated catalyst from cinchona alkaloid, tetraisopropyl titanate [Ti(OiPr)(4)] and an achiral modified biphenol. With TMSCN as the cyanide source, good to excellent results have been achieved for the Strecker reaction of N-Ts (Ts=p-toluenesulfonyl) aldimines and ketimines (up to >99% yield and >99% ee) as well as for the cyanation of ketones (up to 99% yield and 98% ee). By using CNCOOEt as the alternative cyanide source, cyanation of aldehyde was accomplished and various enantioenriched cyanohydrin carbonates were prepared in up to 99% yield and 96% ee. Noteworthy, CNCOOEt was successfully employed for the first time in the asymmetric Strecker reaction of aldimines and ketimines, affording various alpha-amino nitriles with excellent yields and ee values (up to >99% yield and >99% ee). The merits of current protocol involved facile availability of ligand components, operational simplicity and mild reaction conditions, which made it convenient to prepare synthetically important chiral cyanohydrins and alpha-amino nitriles. Furthermore, control experiments and NMR analyses were performed to shed light on the catalyst structure. It is indicated that all the hydroxyl groups in cinchona alkaloid and biphenol complex with Ti(IV), forming the catalyst with the structure of (biphenoxide)Ti(OR*)(OiPr). The absolute configuration adopted by biphenol 4 m in the catalyst was identified as S configuration according to the evidence from control experiments and NMR analyses. Moreover, the roles of the protonic additive (iPrOH) and the tertiary amine in the cinchona alkaloid were studied in detail, and the real cyanide reagent in the catalytic cycle was found to be hydrogen cyanide (HCN). Finally, two plausible catalytic cycles were proposed to elucidate the reaction

  11. Cytochrome P450BM-3 reduces aldehydes to alcohols through a direct hydride transfer

    SciTech Connect

    Kaspera, Ruediger; Sahele, Tariku; Lakatos, Kyle; Totah, Rheem A.

    2012-02-17

    Highlights: Black-Right-Pointing-Pointer Cytochrome P450BM-3 reduced aldehydes to alcohols efficiently (k{sub cat} {approx} 25 min{sup -1}). Black-Right-Pointing-Pointer Reduction is a direct hydride transfer from R-NADP{sup 2}H to the carbonyl moiety. Black-Right-Pointing-Pointer P450 domain variants enhance reduction through potential allosteric/redox interactions. Black-Right-Pointing-Pointer Novel reaction will have implications for metabolism of xenobiotics. -- Abstract: Cytochrome P450BM-3 catalyzed the reduction of lipophilic aldehydes to alcohols efficiently. A k{sub cat} of {approx}25 min{sup -1} was obtained for the reduction of methoxy benzaldehyde with wild type P450BM-3 protein which was higher than in the isolated reductase domain (BMR) alone and increased in specific P450-domain variants. The reduction was caused by a direct hydride transfer from preferentially R-NADP{sup 2}H to the carbonyl moiety of the substrate. Weak substrate-P450-binding of the aldehyde, turnover with the reductase domain alone, a deuterium incorporation in the product from NADP{sup 2}H but not D{sub 2}O, and no inhibition by imidazole suggests the reductase domain of P450BM-3 as the potential catalytic site. However, increased aldehyde reduction by P450 domain variants (P450BM-3 F87A T268A) may involve allosteric or redox mechanistic interactions between heme and reductase domains. This is a novel reduction of aldehydes by P450BM-3 involving a direct hydride transfer and could have implications for the metabolism of endogenous substrates or xenobiotics.

  12. SELECTIVE OXIDATION OF ALCOHOLS - COMPARING DIFFERENT CATALYTIC PROCESSES

    EPA Science Inventory

    Oxidation of alcohols to aldehydes, ketones or carboxylic acids is one of the most desirable chemical transformations in organic synthesis as these products are important precursors and intermediates for many drugs, vitamins and fragrances. Numerous methods are available for alc...

  13. ALCOHOL OXIDATION - A COMPARATIVE STUDY OF DIFFERENT CATALYTIC PROCESSES

    EPA Science Inventory

    Oxidation of alcohols to aldehydes, ketones or carboxylic acids is one of the most desirable chemical transformations in organic synthesis as these products are important precursors and intermediates for many drugs, vitamins and fragrances. Numerous methods are available for alco...

  14. A versatile ruthenium(II)-NNC complex catalyst for transfer hydrogenation of ketones and Oppenauer-type oxidation of alcohols.

    PubMed

    Du, Wangming; Wang, Liandi; Wu, Ping; Yu, Zhengkun

    2012-09-10

    A ruthenium(II)-NNC pincer complex containing an unsymmetrical tridentate pyrazolyl-pyridyl-tolyl ligand was synthesized and structually characterized. This complex exhibited excellent catalytic activity for the transfer hydrogenation of ketones in 2-propanol at reflux, and for the Oppenauer-type dehydrogenative oxidation of alcohols in acetone at reflux (see scheme). PMID:22887575

  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. Cyclopentadienone Iron Alcohol Complexes: Synthesis, Reactivity, and Implications for the Mechanism of Iron Catalyzed Hydrogenation of Aldehydes

    PubMed Central

    Casey, Charles P.; Guan, Hairong

    2009-01-01

    Cyclopentadienone iron alcohol complexes generated from the reactions of [2,5-(SiMe3)2-3,4-(CH2)4(η5-C4COH)]Fe(CO)2H (3) and aldehydes were characterized by 1H NMR, 13C NMR, and IR spectroscopy. The benzyl alcohol complex [2,5-(SiMe3)2-3,4-(CH2)4(η5-C4C=O)]Fe(CO)2(HOCH2C6H5) (6-H) was also characterized by X-ray crystallography. These alcohol complexes are thermally unstable and prone to dissociate the coordinated alcohols. The alcohol ligand is easily replaced by other ligands such as PhCN, pyridine, and PPh3. Dissociation of the alcohol ligand in the presence of H2 leads to the formation of iron hydride 3. The reduction of aldehydes by 3 was carried out in the presence of both potential intermolecular and intramolecular traps. The reaction of 3 with PhCHO in the presence of 4-methylbenzyl alcohol as a potential intermolecular trapping agent initially produced only iron complex 6-H of the newly formed benzyl alcohol. However, the reaction of 3 with 4-(HOCD2)C6H4CHO (11-d2), which possesses a potential intramolecular alcohol trapping agent, afforded two alcohol complexes, one with the newly formed alcohol coordinated to iron and the other with the trapping alcohol coordinated. The intramolecular trapping experiments support a mechanism involving concerted transfer of a proton from OH and hydride from Fe of 3 to aldehydes. The kinetics and mechanism of the hydrogenation of benzaldehyde catalyzed by 3 are presented. PMID:19193034

  17. 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

  18. Azotobacter vinelandii Aldehyde Dehydrogenase Regulated by ς54: Role in Alcohol Catabolism and Encystment

    PubMed Central

    Gama-Castro, Socorro; Núñez, Cinthia; Segura, Daniel; Moreno, Soledad; Guzmán, Josefina; Espín, Guadalupe

    2001-01-01

    Encystment in Azotobacter vinelandii is induced by n-butanol or β-hydroxybutyrate (BHB). We identified a gene, encoding an aldehyde dehydrogenase, that was named aldA. An aldA mutation impaired bacterial growth on n-butanol, ethanol, or hexanol as the sole carbon source. Expression of aldA increased in cells shifted from sucrose to n-butanol and was shown to be dependent on the alternative ς54 factor. A mutation in rpoN encoding the ς54 factor also impaired growth on alcohols. Encystment on n-butanol, but not on BHB, was impaired in aldA or rpoN mutants, indicating that n-butanol is not an inducer of encystment by itself but must be catabolized in order to induce encystment. PMID:11591659

  19. Geometric specificity of alcohol dehydrogenases and its potential for separation of trans and cis isomers of unsaturated aldehydes.

    PubMed Central

    Klibanov, A M; Giannousis, P P

    1982-01-01

    The geometric specificity of three different alcohol dehydrogenases (alcohol:NAD+ oxidoreductase, EC 1.1.1.1) (from yeast, from horse liver, and from Leuconostoc mesenteroides) in the reduction of trans- and cis-cinnamaldehydes has been investigated. All three enzymes display a remarkable trans specificity: they react with the trans isomer 7 to 647 times faster than with its cis counterpart. Experiments with the enzymatic reduction of 3-phenylpropionaldehyde, a saturated analog of cinnamaldehyde, have revealed that whereas trans-cinnamaldehyde possesses the "right" configuration for the active centers of the alcohol dehydrogenases, the cis isomer apparently does not fit the active centers well. All three alcohol dehydrogenases studied also exhibit a marked trans specificity in the reaction with alpha-methylcinnamaldehyde. The geometric specificity of alcohol dehydrogenases can be used for the production of otherwise hard to synthesize cis isomers of unsaturated aldehydes from their readily available trans counterparts: trans-cinnamaldehyde was irradiated with ultraviolet light (which converted it to a mixture of trans and cis isomers) then treated with NADH and yeast alcohol dehydrogenase (which selectively reduces only trans aldehyde into the alcohol), and finally the mixture of cis-cinnamaldehyde and trans-cinnamyl alcohol was separated easily by preparative column chromatography. PMID:7048306

  20. Low Km aldehyde dehydrogenase (ALDH2) polymorphism, alcohol-drinking behavior, and chromosome alterations in peripheral lymphocytes.

    PubMed Central

    Morimoto, K; Takeshita, T

    1996-01-01

    Excessive drinking of alcohol is now widely known to be one of the major lifestyle choices that ca effect health. Among the various effects of alcohol drinking, cytogenetic and other genotoxic effects are of major concern from the viewpoint of prevention of alcohol-related diseases. Alcohol is first metabolized to acetaldehyde, which directly causes various types of chromosomal DNA lesions and alcohol-related diseases, and is then further detoxified to the much less toxic metabolite acetate. About 50% of Oriental people are deficient in the aldehyde-dehydrogenase 2 isozyme (ALDH2) that can most efficiently detoxify acetaldehyde. We have performed a series of experiments to investigate how the genetic deficiency in ALDH2 affects the behavioral pattern for alcohol drinking and the sensitivity of peripheral lymphocytes to the induction of chromosome alterations by exposure to alcohol and alcohol-related chemicals. We found great effects of the ALDH2 genotypes on alcohol sensitivity and alcohol-drinking behavior. We also show that lymphocytes from habitual drinkers with the deficient ALDH2 enzyme had significantly higher frequencies of sister chromatid exchanges than those from ALDH2-proficient individuals. PMID:8781384

  1. 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

  2. NAD(P)-Dependent Aldehyde Dehydrogenases Induced during Growth of Ralstonia eutropha Strain Bo on Tetrahydrofurfuryl Alcohol

    PubMed Central

    Schräder, Thomas; Zarnt, Grit; Andreesen, Jan R.

    2001-01-01

    Different aldehyde dehydrogenases (AlDHs) were formed during growth of Ralstonia eutropha Bo on tetrahydrofurfuryl alcohol (THFA). One of these enzymes, AlDH 4, was purified and characterized as a homodimer containing no prosthetic groups, showing a strong substrate inhibition, and having an N-terminal sequence similar to those of various NAD(P)-dependent AlDHs. The conversion rate of THFA by the quinohemoprotein THFA dehydrogenase was increased by AlDH 4. PMID:11717302

  3. High current density PQQ-dependent alcohol and aldehyde dehydrogenase bioanodes.

    PubMed

    Aquino Neto, Sidney; Hickey, David P; Milton, Ross D; De Andrade, Adalgisa R; Minteer, Shelley D

    2015-10-15

    In this paper, we explore the bioelectrooxidation of ethanol using pyrroloquinoline quinone (PQQ)-dependent alcohol and aldehyde dehydrogenase (ADH and AldDH) enzymes for biofuel cell applications. The bioanode architectures were designed with both direct electron transfer (DET) and mediated electron transfer (MET) mechanisms employing high surface area materials such as multi-walled carbon nanotubes (MWCNTs) and MWCNT-decorated gold nanoparticles, along with different immobilization techniques. Three different polymeric matrices were tested (tetrabutyl ammonium bromide (TBAB)-modified Nafion; octyl-modified linear polyethyleneimine (C8-LPEI); and cellulose) in the DET studies. The modified Nafion membrane provided the best electrical communication between enzymes and the electrode surface, with catalytic currents as high as 16.8 ± 2.1 µA cm(-2). Then, a series of ferrocene redox polymers were evaluated for MET. The redox polymer 1,1'-dimethylferrocene-modified linear polyethyleneimine (FcMe2-C3-LPEI) provided the best electrochemical response. Using this polymer, the electrochemical assays conducted in the presence of MWCNTs and MWCNTs-Au indicated a Jmax of 781 ± 59 µA cm(-2) and 925 ± 68 µA cm(-2), respectively. Overall, from the results obtained here, DET using the PQQ-dependent ADH and AldDH still lacks high current density, while the bioanodes that operate via MET employing ferrocene-modified LPEI redox polymers show efficient energy conversion capability in ethanol/air biofuel cells. PMID:25988787

  4. Vertical transport of steroid alcohols and ketones measured in a sediment trap experiment in the equatorial Atlantic Ocean

    NASA Astrophysics Data System (ADS)

    Gagosian, Robert B.; Smith, Steven O.; Nigrelli, Gale E.

    1982-07-01

    The vertical flux and free steroid alcohol (sterol) and ketone composition of particulate material was determined using sediment traps deployed at 389, 988, 3755 and 5068 m at a station in the equatorial North Atlantic, PARFLUX E. Cholest-5-en-3β-ol (cholesterol) was found to be the dominant sterol in all the traps. This compound had a maximum flux at 988 m, accounting for more than 90% of the sterols at this depth. Inputs from mesopelagic Zooplankton populations living in or migrating to depths between the 389 and 988 m traps appear to be responsible for this distribution. The deeper two traps exhibited an increased flux of phytosterols relative to cholesterol, probably due to (a) the incorporation of labile phytoplankton remains in fecal pellets and rapid transport into the deep sea and (b) differential dissolution of heterogeneous large particles. A maximum of 5-22% of the sterols produced in the euphotic zone were present in the 389 m trap. This value drops to less than 1% for the 5068 m trap, 200 m above the sediment surface. In general steroid ketone fluxes gradually decreased with depth. Δ4-Stenones were found in greater abundance than their saturated counterparts. Cholest-4-en-3-one was the major steroid ketone detected in all the traps. A five-fold increase with depth in the cholest-4-en-3-one to cholesterol ratio is most likely due to microbial oxidation of sterols to steroid ketones, or higher Δ4-stenone inputs relative to sterols from organisms.

  5. Pincer and diamine Ru and Os diphosphane complexes as efficient catalysts for the dehydrogenation of alcohols to ketones.

    PubMed

    Baratta, Walter; Bossi, Gianluca; Putignano, Elisabetta; Rigo, Pierluigi

    2011-03-14

    The ruthenium and osmium complexes [MCl(2)(diphosphane)(L)] (M=Ru, Os; L=bidentate amino ligand) and [MCl(CNN)(dppb)] (CNN=pincer ligand; dppb=1,4-bis-(diphenylphosphino)butane), containing the N−H moiety, have been found to catalyze the acceptorless dehydrogenation of alcohols in tBuOH and in the presence of KOtBu. The compounds trans-[MCl(2)(dppf)(en)] (M=Ru 7, Os 13; dppf=1,1'-bisdiphenylphosphino)ferrocene; en=ethylenediamine) display very high activity and different substrates, including cyclic and linear alcohols, are efficiently oxidized to ketones by using 0.8-0.04 mol % of catalyst. The effect of the base and the comparison of the catalytic activity of the Ru versus Os complexes are reported. The ruthenium complex 7 generally leads to a faster conversion into ketones with respect to the osmium complex 13, which displays better activity in the dehydrogenation of 5-en-3β-hydroxy steroids. The synthesis of new Ru and Os complexes [MCl(2)(PP)(L)] (PP=dppb, dppf; L=(±)-trans-1,2-diaminocyclohexane,2-(aminomethyl)pyridine, and 2-aminoethanol) of trans and cis configuration is also reported. PMID:21341330

  6. Exudation of alcohol and aldehyde sugars from roots of defoliated Lolium perenne L. grown under sterile conditions.

    PubMed

    Clayton, Stephen J; Read, Derek B; Murray, Philip J; Gregory, Peter J

    2008-11-01

    Root exudates were collected over a 27 day period from defoliated and non-defoliated Lolium perenne L. plants grown under sterile conditions in microlysimeters. Eleven individual sugars, including both aldehyde and alcohol sugars, were identified and quantified with a gas chromatograph-mass spectrometer (GC-MS). There was no change in the number of sugars present between 7 and 27 days, but the exudation of alcohol sugars decreased rapidly at about day 12. Xylose and glucose were present in the largest amounts. Defoliation initially increased the total amount of sugars in the exudates, but continuous defoliation reduced total sugar exudation by 16% and induced changes in the exudation patterns of individual sugars. Defoliation enhanced exudation of erythritol, threitol, and xylitol, reduced exudation of glucose and arabitol, but had little effect on the amounts of other sugars exuded. The more complex 6 C, 5 OH aldehyde sugars, especially glucose, showed changes earlier and to a greater extent (17 days), than the 5 C, 4 OH (xylose and ribose) and 6 C 4 OH (fucose) aldehyde groups. These findings confirm the general finding that repeated defoliation reduces the quantity of total sugars exuded, but the pattern of release of individual sugars is complex and variable. PMID:18815840

  7. Metabolic basis of ethylene glycol monobutyl ether (2-butoxyethanol) toxicity: role of alcohol and aldehyde dehydrogenases

    SciTech Connect

    Ghanayem, B.I.; Burka, L.T.; Matthews, H.B.

    1987-07-01

    2-Butoxyethanol (BE) is a massively produced glycol ether of which more than 230 million pounds was produced in the United States in 1983. It is extensively used in aerosols and cleaning agents intended for household use. This creates a high potential for human exposure during its manufacturing and use. A single exposure of rats to BE causes severe hemolytic anemia accompanied by secondary hemoglobinuria as well as liver and kidney damage. Butoxyacetic acid (BAA) was earlier identified as a urinary metabolite of BE. In addition, we have recently identified two additional urinary metabolites of BE, namely, BE-glucuronide and BE-sulfate conjugates. The current studies were undertaken to investigate the metabolic basis of BE-induced hematotoxicity in male F344 rats. Treatment of rats with pyrazole (alcohol dehydrogenase inhibitor) protected rats against BE-induced hematotoxicity and inhibited BE metabolism to BAA. Pyrazole inhibition of BE metabolism to BAA was accompanied by increased BE metabolism to BE-glucuronide and BE-sulfate as determined by quantitative high-performance liquid chromatography analysis of BE metabolites in urine. There was approximately a 10-fold decrease in the ratio of BAA to BE-glucuronide + BE-sulfate in the urine of rats treated with pyrazole + BE compared to rats treated with BE alone. Pretreatment of rats with cyanamide (aldehyde dehydrogenase inhibitor) also significantly protected rats against BE-induced hematotoxicity and modified BE metabolism in a manner similar to that caused by pyrazole. Administration of equimolar doses of BE, the metabolic intermediate butoxyacetaldehyde, or the ultimate metabolite BAA caused similar hematotoxic effects. Cyanamide also protected rats against butoxyacetaldehyde-induced hematotoxicity.

  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. Nitrosobenzene as a hydrogen acceptor in rhodium catalysed dehydrogenation reactions of alcohols: synthesis of aldehydes and azoxybenzenes.

    PubMed

    Annen, Samuel P; Grützmacher, Hansjörg

    2012-12-14

    Acids, esters and amides have to date been the only isolated products from the dehydrogenation of primary alcohols with [Rh(trop(2)N)(L)] (trop = 5-H-dibenzo[a,d]cyclohepten-5yl) type complexes. With the reported method the available product family is finally to aldehydes. Using nitrosobenzene as a hydrogen acceptor the aldehydes could be isolated in up to 96% yield with substrate to catalyst ratios of up to 1000. Nitrosobenzene was found to be reductively coupled to azoxybenzene under the reaction conditions. Several symmetrically substituted azoxybenzene derivatives could be isolated in generally high yields after 2 to 4 h reaction time using a low catalyst loading. PMID:23032195

  10. Copper(II)-catalyzed hydrosilylation of ketones using chiral dipyridylphosphane ligands: highly enantioselective synthesis of valuable alcohols.

    PubMed

    Yu, Feng; Zhou, Ji-Ning; Zhang, Xi-Chang; Sui, Yao-Zong; Wu, Fei-Fei; Xie, Lin-Jie; Chan, Albert S C; Wu, Jing

    2011-12-01

    In the presence of PhSiH(3) as the reductant, the combination of enantiomeric dipyridylphosphane ligands and Cu(OAc)(2)·H(2)O, which is an easy-to-handle and inexpensive copper salt, led to a remarkably practical and versatile chiral catalyst system. The stereoselective formation of a selection of synthetically interesting β-, γ- or δ-halo alcohols bearing high degrees of enantiopurity (up to 99.9% enantiomeric excess (ee)) was realized with a substrate-to-ligand molar ratio (S/L) of up to 10,000. The present protocol also allowed the hydrosilylation of a diverse spectrum of alkyl aryl ketones with excellent enantioselectivities (up to 98% ee) and exceedingly high turn-over rates (up to 50,000 S/L molar ratio in 50 min reaction time) in air, under very mild conditions, which offers great opportunities for the preparation of various physiologically active targets. The synthetic utility of the chiral products obtained was highlighted by the efficient conversion of optically enriched β-halo alcohols into the corresponding styrene oxide, β-amino alcohol, and β-azido alcohol, respectively. PMID:22065457

  11. Sjögren-Larsson syndrome. Deficient activity of the fatty aldehyde dehydrogenase component of fatty alcohol:NAD+ oxidoreductase in cultured fibroblasts.

    PubMed Central

    Rizzo, W B; Craft, D A

    1991-01-01

    Sjögren-Larsson syndrome (SLS) is an inherited disorder associated with impaired fatty alcohol oxidation due to deficient activity of fatty alcohol:NAD+ oxidoreductase (FAO). FAO is a complex enzyme which consists of two separate proteins that sequentially catalyze the oxidation of fatty alcohol to fatty aldehyde and fatty acid. To determine which enzymatic component of FAO was deficient in SLS, we assayed fatty aldehyde dehydrogenase (FALDH) and fatty alcohol dehydrogenase in cultured fibroblasts from seven unrelated SLS patients. All SLS cells were selectively deficient in the FALDH component of FAO, and had normal activity of fatty alcohol dehydrogenase. The extent of FALDH deficiency in SLS cells depended on the aliphatic aldehyde used as substrate, ranging from 62% of mean normal activity using propionaldehyde as substrate to 8% of mean normal activity with octadecanal. FALDH activity in obligate SLS heterozygotes was partially decreased to 49 +/- 7% of mean normal activity using octadecanal as substrate. Differential centrifugation studies in fibroblasts indicated that this FALDH enzyme was largely particulate; soluble FALDH activity was normal in SLS cells. Intact SLS fibroblasts oxidized octadecanol to fatty acid at less than 10% of the normal rate, but oxidized free octadecanal normally, suggesting that the FALDH affected in SLS is chiefly involved in the oxidation of fatty alcohol to fatty acid. These results show that the primary enzymatic defect in SLS is the FALDH component of the FAO complex, which leads to deficient oxidation of fatty aldehyde derived from fatty alcohol. PMID:1939650

  12. Room-Temperature Reactivity Of Silicon Nanocrystals With Solvents: The Case Of Ketone And Hydrogen Production From Secondary Alcohols: Catalysis?

    PubMed

    El-Demellawi, Jehad K; Holt, Christopher R; Abou-Hamad, Edy; Al-Talla, Zeyad A; Saih, Youssef; Chaieb, Sahraoui

    2015-07-01

    Although silicon nanoparticles dispersed in liquids are used in various applications ranging from biolabeling to hydrogen production, their reactivities with their solvents and their catalytic properties remain still unexplored. Here, we discovered that, because of their surface structures and mechanical strain, silicon nanoparticles react strongly with their solvents and may act as catalysts for the dehydrogenation, at room temperature, of secondary alcohols (e.g., isopropanol) into ketones and hydrogen. This catalytic reaction was monitored by gas chromatography, pH measurements, mass spectroscopy, and solid-state NMR. This discovery provides new understanding of the role played by silicon nanoparticles, and nanosilicon in general, in their reactivity in solvents in general, as well as being candidates in catalysis. PMID:26024366

  13. Substrate Specificity and Subcellular Localization of the Aldehyde-Alcohol Redox-coupling Reaction in Carp Cones*

    PubMed Central

    Sato, Shinya; Fukagawa, Takashi; Tachibanaki, Shuji; Yamano, Yumiko; Wada, Akimori; Kawamura, Satoru

    2013-01-01

    Our previous study suggested the presence of a novel cone-specific redox reaction that generates 11-cis-retinal from 11-cis-retinol in the carp retina. This reaction is unique in that 1) both 11-cis-retinol and all-trans-retinal were required to produce 11-cis-retinal; 2) together with 11-cis-retinal, all-trans-retinol was produced at a 1:1 ratio; and 3) the addition of enzyme cofactors such as NADP(H) was not necessary. This reaction is probably part of the reactions in a cone-specific retinoid cycle required for cone visual pigment regeneration with the use of 11-cis-retinol supplied from Müller cells. In this study, using purified carp cone membrane preparations, we first confirmed that the reaction is a redox-coupling reaction between retinals and retinols. We further examined the substrate specificity, reaction mechanism, and subcellular localization of this reaction. Oxidation was specific for 11-cis-retinol and 9-cis-retinol. In contrast, reduction showed low specificity: many aldehydes, including all-trans-, 9-cis-, 11-cis-, and 13-cis-retinals and even benzaldehyde, supported the reaction. On the basis of kinetic studies of this reaction (aldehyde-alcohol redox-coupling reaction), we found that formation of a ternary complex of a retinol, an aldehyde, and a postulated enzyme seemed to be necessary, which suggested the presence of both the retinol- and aldehyde-binding sites in this enzyme. A subcellular fractionation study showed that the activity is present almost exclusively in the cone inner segment. These results suggest the presence of an effective production mechanism of 11-cis-retinal in the cone inner segment to regenerate visual pigment. PMID:24217249

  14. Alcohol dehydrogenases from Scheffersomyces stipitis involved in the detoxification of aldehyde inhibitors derived from lignocellulosic biomass conversion.

    PubMed

    Ma, Menggen; Wang, Xu; Zhang, Xiaoping; Zhao, Xianxian

    2013-09-01

    Aldehyde inhibitors such as furfural and 5-hydroxymethylfurfural (HMF) are generated from biomass pretreatment. Scheffersomyces stipitis is able to reduce furfural and HMF to less toxic furanmethanol and furan-2,5-dimethanol; however, the enzymes involved in the reductive reaction still remain unknown. In this study, transcription responses of two known and five putative alcohol dehydrogenase genes from S. stipitis were analyzed under furfural and HMF stress conditions. All the seven alcohol dehydrogenase genes were also cloned and overexpressed for their activity analyses. Our results indicate that transcriptions of SsADH4 and SsADH6 were highly induced under furfural and HMF stress conditions, and the proteins encoded by them exhibited NADH- and/or NADPH-dependent activities for furfural and HMF reduction, respectively. For furfural reduction, NADH-dependent activity was also observed in SsAdh1p and NAD(P)H-dependent activities were also observed in SsAdh5p and SsAdh7p. For HMF reduction, NADPH-dependent activities were also observed in SsAdh5p and SsAdh7p. SsAdh4p displayed the highest NADPH-dependent specific activity and catalytic efficiency for reduction of both furfural and HMF among the seven alcohol dehydrogenases. Enzyme activities of all SsADH proteins were more stable under acidic condition. For most SsADH proteins, the optimum temperature for enzyme activities was 30 °C and more than 50 % enzyme activities remained at 60 °C. Reduction activities of formaldehyde, acetaldehyde, isovaleraldehyde, benzaldehyde, and phenylacetaldehyde were also observed in some SsADH proteins. Our results indicate that multiple alcohol dehydrogenases in S. stipitis are involved in the detoxification of aldehyde inhibitors derived from lignocellulosic biomass conversion. PMID:23912116

  15. Strong Protective Effect of The Aldehyde Dehydrogenase Gene (ALDH2) 504lys (*2) Allele Against Alcoholism And Alcohol-Induced Medical Diseases in Asians

    PubMed Central

    Li, Dawei; Zhao, Hongyu; Gelernter, Joel

    2013-01-01

    Alcohol is oxidized to acetaldehyde, which in turn is oxidized to acetate. The aldehyde dehydrogenase 2 gene (ALDH2) is the most important gene responsible for acetaldehyde metabolism. Individuals heterozygous or homozygous for the lys (A or *2) allele at the single nucleotide polymorphism (SNP) glu504lys (rs671) of ALDH2 have greatly reduced ability to metabolize acetaldehyde, which greatly decreases their risk for alcohol dependence (AD). Case-control studies have shown association between this SNP and alcohol dependence as well as alcohol-induced liver disease. However, some studies have produced insignificant results. Using cumulative data from the past 20 years predominately from Asian populations (from both English and Chinese publications), this meta-analysis sought to examine and update whether the aggregate data provide new evidence of statistical significance for the proposed association. Our results (9,678 cases and 7,331 controls from 53 studies) support a strong association of alcohol abuse and dependence, with allelic P value of 3×10−56 and OR of 0.23 (0.2, 0.28) under the random effects model. The dominant model (lys-lys + lys-glu vs. glu-glu) also showed strong association with P value of 1×10−44 and OR of 0.22 (0.18, 0.27). When stricter criteria and various sub-group analyses were applied, the association remained strong (for example, OR = 0.23 (0.18, 0.3) and P = 2×10−28 for the alcoholic patients with alcoholic liver disease, cirrhosis, or pancreatitis). These findings provide confirmation of the involvement of the human ALDH2 gene in the pathogenesis of AD as well as alcohol-induced medical illnesses in East-Asians. PMID:22102315

  16. Controlled Reduction of Tertiary Amides to the Corresponding Alcohols, Aldehydes, or Amines Using Dialkylboranes and Aminoborohydride Reagents.

    PubMed

    Bailey, Christopher L; Joh, Alexander Y; Hurley, Zefan Q; Anderson, Christopher L; Singaram, Bakthan

    2016-05-01

    Dialkylboranes and aminoborohydrides are mild, selective reducing agents complementary to the commonly utilized amide reducing agents, such as lithium aluminum hydride (LiAlH4) and diisobutylaluminum hydride (DIBAL) reagents. Tertiary amides were reduced using 1 or 2 equiv of various dialkylboranes. The reduction of tertiary amides required 2 equiv of 9-borabicyclo[3.3.1]nonane (9-BBN) for complete reduction to give the corresponding tertiary amines. One equivalent of sterically hindered disiamylborane reacts with tertiary amides to afford the corresponding aldehydes. Aminoborohydrides are powerful and selective reducing agents for the reduction of tertiary amides. Lithium dimethylaminoborohydride and lithium diisopropylaminoborohydride are prepared from n-butyllithium and the corresponding amine-borane. Chloromagnesium dimethylaminoborohydride (ClMg(+)[H3B-NMe2](-), MgAB) is prepared by the reaction of dimethylamine-borane with methylmagnesium chloride. Solutions of aminoborohydride reduce aliphatic, aromatic, and heteroaromatic tertiary amides to give the corresponding alcohol, amine, or aldehyde depending on the steric requirement of the tertiary amide and the aminoborohydride used. PMID:27035215

  17. Evaluation of alcohol dehydrogenase and aldehyde dehydrogenase enzymes as bi-enzymatic anodes in a membraneless ethanol microfluidic fuel cell

    NASA Astrophysics Data System (ADS)

    Galindo-de-la-Rosa, J.; Arjona, N.; Arriaga, L. G.; Ledesma-García, J.; Guerra-Balcázar, M.

    2015-12-01

    Alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (AldH) enzymes were immobilized by covalent binding and used as the anode in a bi-enzymatic membraneless ethanol hybrid microfluidic fuel cell. The purpose of using both enzymes was to optimize the ethanol electro-oxidation reaction (EOR) by using ADH toward its direct oxidation and AldH for the oxidation of aldehydes as by-products of the EOR. For this reason, three enzymatic bioanode configurations were evaluated according with the location of enzymes: combined, vertical and horizontally separated. In the combined configuration, a current density of 16.3 mA cm-2, a voltage of 1.14 V and a power density of 7.02 mW cm-2 were obtained. When enzymes were separately placed in a horizontal and vertical position the ocp drops to 0.94 V and to 0.68 V, respectively. The current density also falls to values of 13.63 and 5.05 mA cm-2. The decrease of cell performance of bioanodes with separated enzymes compared with the combined bioanode was of 31.7% and 86.87% for the horizontal and the vertical array.

  18. One-pot synthesis of amides by aerobic oxidative coupling of alcohols or aldehydes with amines using supported gold and base as catalysts.

    PubMed

    Kegnæs, Søren; Mielby, Jerrik; Mentzel, Uffe V; Jensen, Thomas; Fristrup, Peter; Riisager, Anders

    2012-02-28

    Synthesis of amides by aerobic oxidative coupling of alcohols or aldehydes with amines via intermediate formation of methyl esters is highly efficient and selective when using a catalytic system comprised of supported gold nanoparticles and added base in methanol. PMID:22274843

  19. Folate, alcohol, and aldehyde dehydrogenase 2 polymorphism and the risk of oral and pharyngeal cancer in Japanese.

    PubMed

    Matsuo, Keitaro; Rossi, Marta; Negri, Eva; Oze, Isao; Hosono, Satoyo; Ito, Hidemi; Watanabe, Miki; Yatabe, Yasushi; Hasegawa, Yasuhisa; Tanaka, Hideo; Tajima, Kazuo; La Vecchia, Carlo

    2012-03-01

    Folate consumption is inversely associated with the risk of oral and pharyngeal cancer (OPC) and potentially interacts with alcohol drinking in the risk of OPC. Aldehyde dehydrogenase 2 (ALDH2) gene polymorphism is known to interact with alcohol consumption. The aim of this study was to investigate potential interaction between folate, alcohol drinking, and ALDH2 polymorphism in the risk of OPC in a Japanese population. The study group comprised 409 head and neck cancer cases and 1227 age-matched and sex-matched noncancer controls; of these, 251 cases and 759 controls were evaluated for ALDH rs671 polymorphism. Associations were assessed by odds ratios and 95% confidence intervals in multiple logistic regression models. We observed an inverse association between folate consumption and OPC risk. The odds ratio for high folate intake was 0.53 (95% confidence interval: 0.36-0.77) relative to low intake (P trend=0.003). This association was consistent across strata of sex, age, smoking, and ALDH2 genotypes. Interaction between folate consumption, drinking, and ALDH2 genotype was remarkable (three-way interaction, P<0.001). We observed significant interaction among folate, drinking, and ALDH2 genotype in the Japanese population. PMID:21946912

  20. Activity and electrophoretic profiles of liver aldehyde dehydrogenases from mice of inbred strains with different alcohol preference.

    PubMed

    Yamazaki, H; Nishiguchi, K; Miyamoto, R; Ogita, Z I; Nakanishi, S

    1983-01-01

    1. The activity of low Km-aldehyde dehydrogenase (ALDH) in the liver mitochondrial fraction (MT-fraction) from male C57BL/6J strain mice (alcohol preferring) was significantly higher than that from DBA/2 mice (alcohol avoiding). The F1 hybrids (C57BL/6J X DBA/2) did not exhibit the intermediate activity to these two strains. 2. Strain differences in liver mitochondrial ALDH isozymes were observed by isoelectric focusing. C57BL/6J strain had two isozymes at pH 7.1 while DBA/2 had no band at this pH. F1 hybrid mice had similar two bands with lower density to those of C57BL/6J at pH 7.1. There was no difference in zymograms of the soluble fraction between C57BL/6J and DBA/2 strains. 3. The present results suggest that the difference in alcohol preference of mice may depend on some restricted ALDH isozymes with different pl or electric mobility rather than the enzymatic activity in the liver MT-fraction. PMID:6822317

  1. Expression of a heat-stable NADPH-dependent alcohol dehydrogenase in Caldicellulosiruptor bescii results in furan aldehyde detoxification

    SciTech Connect

    Chung, Daehwan; Verbeke, Tobin J.; Cross, Karissa L.; Westpheling, Janet; Elkins, James G.

    2015-07-22

    Compounds such as furfural and 5-hydroxymethylfurfural (5-HMF) are generated through the dehydration of xylose and glucose, respectively, during dilute-acid pretreatment of lignocellulosic biomass and are also potent microbial growth and fermentation inhibitors. The enzymatic reduction of these furan aldehydes to their corresponding, and less toxic, alcohols is an engineering approach that has been successfully implemented in both Saccharomyces cerevisiae and ethanologenicEscherichia coli, but has not yet been investigated in thermophiles relevant to biofuel production through consolidated bioprocessing (CBP). Developing CBP-relevant biocatalysts that are either naturally resistant to such inhibitors, or are amenable to engineered resistance, is therefore, an important component in making biofuels production from lignocellulosic biomass feasible.

  2. Expression of a heat-stable NADPH-dependent alcohol dehydrogenase in Caldicellulosiruptor bescii results in furan aldehyde detoxification

    DOE PAGESBeta

    Chung, Daehwan; Verbeke, Tobin J.; Cross, Karissa L.; Westpheling, Janet; Elkins, James G.

    2015-07-22

    Compounds such as furfural and 5-hydroxymethylfurfural (5-HMF) are generated through the dehydration of xylose and glucose, respectively, during dilute-acid pretreatment of lignocellulosic biomass and are also potent microbial growth and fermentation inhibitors. The enzymatic reduction of these furan aldehydes to their corresponding, and less toxic, alcohols is an engineering approach that has been successfully implemented in both Saccharomyces cerevisiae and ethanologenicEscherichia coli, but has not yet been investigated in thermophiles relevant to biofuel production through consolidated bioprocessing (CBP). Developing CBP-relevant biocatalysts that are either naturally resistant to such inhibitors, or are amenable to engineered resistance, is therefore, an important componentmore » in making biofuels production from lignocellulosic biomass feasible.« less

  3. Elucidating the contributions of multiple aldehyde/alcohol dehydrogenases to butanol and ethanol production in Clostridium acetobutylicum

    PubMed Central

    Dai, Zongjie; Dong, Hongjun; Zhang, Yanping; Li, Yin

    2016-01-01

    Ethanol and butanol biosynthesis in Clostridium acetobutylicum share common aldehyde/alcohol dehydrogenases. However, little is known about the relative contributions of these multiple dehydrogenases to ethanol and butanol production respectively. The contributions of six aldehyde/alcohol dehydrogenases of C. acetobutylicum on butanol and ethanol production were evaluated through inactivation of the corresponding genes respectively. For butanol production, the relative contributions from these enzymes were: AdhE1 > BdhB > BdhA ≈ YqhD > SMB_P058 > AdhE2. For ethanol production, the contributions were: AdhE1 > BdhB > YqhD > SMB_P058 > AdhE2 > BdhA. AdhE1 and BdhB are two essential enzymes for butanol and ethanol production. AdhE1 was relatively specific for butanol production over ethanol, while BdhB, YqhD, and SMB_P058 favor ethanol production over butanol. Butanol synthesis was increased in the adhE2 mutant, which had a higher butanol/ethanol ratio (8.15:1) compared with wild type strain (6.65:1). Both the SMB_P058 mutant and yqhD mutant produced less ethanol without loss of butanol formation, which led to higher butanol/ethanol ratio, 10.12:1 and 10.17:1, respectively. To engineer a more efficient butanol-producing strain, adhE1 could be overexpressed, furthermore, adhE2, SMB_P058, yqhD are promising gene inactivation targets. This work provides useful information guiding future strain improvement for butanol production. PMID:27321949

  4. Elucidating the contributions of multiple aldehyde/alcohol dehydrogenases to butanol and ethanol production in Clostridium acetobutylicum.

    PubMed

    Dai, Zongjie; Dong, Hongjun; Zhang, Yanping; Li, Yin

    2016-01-01

    Ethanol and butanol biosynthesis in Clostridium acetobutylicum share common aldehyde/alcohol dehydrogenases. However, little is known about the relative contributions of these multiple dehydrogenases to ethanol and butanol production respectively. The contributions of six aldehyde/alcohol dehydrogenases of C. acetobutylicum on butanol and ethanol production were evaluated through inactivation of the corresponding genes respectively. For butanol production, the relative contributions from these enzymes were: AdhE1 > BdhB > BdhA ≈ YqhD > SMB_P058 > AdhE2. For ethanol production, the contributions were: AdhE1 > BdhB > YqhD > SMB_P058 > AdhE2 > BdhA. AdhE1 and BdhB are two essential enzymes for butanol and ethanol production. AdhE1 was relatively specific for butanol production over ethanol, while BdhB, YqhD, and SMB_P058 favor ethanol production over butanol. Butanol synthesis was increased in the adhE2 mutant, which had a higher butanol/ethanol ratio (8.15:1) compared with wild type strain (6.65:1). Both the SMB_P058 mutant and yqhD mutant produced less ethanol without loss of butanol formation, which led to higher butanol/ethanol ratio, 10.12:1 and 10.17:1, respectively. To engineer a more efficient butanol-producing strain, adhE1 could be overexpressed, furthermore, adhE2, SMB_P058, yqhD are promising gene inactivation targets. This work provides useful information guiding future strain improvement for butanol production. PMID:27321949

  5. Mutual Cooperation in the Formal Allyl Alcohol Nucleophilic Substitution and Hydration of Alkynes for the Construction of γ-Substituted Ketones.

    PubMed

    Huang, Kaimeng; Wang, Hongkai; Liu, Lingyan; Chang, Weixing; Li, Jing

    2016-05-01

    Mutual cooperation in the formal allyl alcohol nucleophilic substitution reaction and hydration of an alkyne has been utilized in the presence of a gold catalyst to give a series of γ-functionalized ketones with high to excellent yields. This reaction actually involved an intramolecular O-H insertion cyclization of an alkyne to form the dihydrofuran intermediate, which was followed by the nucleophilic addition ring-opening of a dihydrofuran to give the target compound. PMID:26946315

  6. 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

  7. Aldehyde Dehydrogenase-2 (ALDH2) Ameliorates Chronic Alcohol Ingestion-Induced Hepatic Steatosis and Inflammation: Role of Autophagy

    PubMed Central

    Guo, Rui; Xu, Xihui; Babcock, Sara A.; Zhang, Yingmei; Ren, Jun

    2014-01-01

    Background & Aims Mitochondrial aldehyde dehydrogenase (ALDH2) plays a critical role in the detoxification of the ethanol metabolite acetaldehyde. This study was designed to examine the impact of global ALDH2 overexpression on alcohol-induced hepatic steatosis. Methods Wild-type friendly virus B (FVB) and ALDH2 transgenic mice were placed on a 4% alcohol or control diet for 12 weeks. Serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), bilirubin and cholesterol, hepatic triglyceride, steatosis, fat metabolism-related proteins, pro-inflammatory cytokines, glutathione (GSH), oxidized glutathione (GSSG), autophagy and autophagy signaling were examined. The role of autophagy was evaluated in ADH1-transfected human hepatocellular liver carcinoma cells (VA-13) treated with or without autophagy inducer rapamycin and lysosomal inhibitors. Results Chronic alcohol intake led to elevated AST, ALT, bilirubin, AST/ALT ratio, cholesterol, hepatic triglycerides, hepatic fat deposition as evidenced by H&E and oil Red O staining, associated with disturbed fat metabolism-related proteins (fatty acid synthase, SCD1), upregulated interleukin-6, TNF-α, cyclooxygenase, oxidative stress, and loss of autophagy, the effects of which were attenuated or ablated by ALDH2 transgene. Moreover, ethanol (100 mM) and acetaldehyde (100, 500 μM) increased levels of IL-6 and IFN-γ, and suppressed autophagy in VA-13 cells, the effects of which were markedly alleviated by rapamycin. In addition, lysosomal inhibitors mimicked ethanol-induced p62 accumulation with little additive effect with ethanol. Ethanol significantly suppressed LC3 conversion in the presence of lysosomal inhibitors. Conclusions In summary, our results revealed that ALDH2 plays a beneficial role in ameliorating chronic alcohol intake-induced hepatic steatosis and inflammation through regulation of autophagy. PMID:25457208

  8. 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

  9. Equilibrium 2H/ 1H fractionations in organic molecules. II: Linear alkanes, alkenes, ketones, carboxylic acids, esters, alcohols and ethers

    NASA Astrophysics Data System (ADS)

    Wang, Ying; Sessions, Alex L.; Nielsen, Robert J.; Goddard, William A., III

    2009-12-01

    Equilibrium 2H/ 1H fractionation factors (α eq) for various H positions in alkanes, alkenes, ketones, carboxylic acids, esters, alcohols, and ethers were calculated between 0 and 100 °C using vibrational frequencies from ab initio QM calculations (B3LYP/6-311G**). Results were then corrected using a temperature-dependent linear calibration curve based on experimental data for H α in ketones ( Wang et al., 2009). The total uncertainty in reported α eq values is estimated at 10-20‰. The effects of functional groups were found to increase the value of α eq for H next to electron-donating groups, e.g. sbnd OR, sbnd OH or sbnd O(C dbnd O)R, and to decrease the value of α eq for H next to electron-withdrawing groups, e.g. sbnd (C dbnd O)R or sbnd (C dbnd O)OR. Smaller but significant functional group effects are also observed for H β and sometimes H γ. By summing over individual H positions, we estimate the equilibrium fractionation relative to water to be -90‰ to -70‰ for n-alkanes and around -100‰ for pristane and phytane. The temperature dependence of these fractionations is very weak between 0 and 100 °C. Our estimates of α eq agree well with field data for thermally mature hydrocarbons (δ 2H values between -80‰ and -110‰ relative to water). Therefore the observed δ 2H increase of individual hydrocarbons and the disappearance of the biosynthetic δ 2H offset between n-alkyl and linear isoprenoid lipids during maturation of organic matter can be confidently attributed to H exchange towards an equilibrium state. Our results also indicate that many n-alkyl lipids are biosynthesized with δ 2H values that are close to equilibrium with water. In these cases, constant down-core δ 2H values for n-alkyl lipids cannot be reliably used to infer a lack of isotopic exchange.

  10. Iridium-catalyzed anti-diastereo- and enantioselective carbonyl (trimethylsilyl)allylation from the alcohol or aldehyde oxidation level.

    PubMed

    Han, Soo Bong; Gao, Xin; Krische, Michael J

    2010-07-01

    Using the ortho-cyclometalated pi-allyl iridium precatalyst (R)-I derived from [Ir(cod)Cl](2), 4-cyano-3-nitrobenzoic acid, (R)-SEGPHOS, and allyl acetate, enantioselective transfer hydrogenation of alpha-(trimethylsilyl)allyl acetate in the presence of aldehydes 2a-i mediated by 2-propanol delivers products of (trimethylsilyl)allylation 4a-i in good isolated yields and with exceptional levels of anti-diastereoselectivity and enantioselectivity (90-99% ee). In the absence of 2-propanol, but under otherwise identical reaction conditions, carbonyl (trimethylsilyl)allylation is achieved directly from the alcohol oxidation level to furnish an equivalent set of adducts 4a-i with roughly equivalent isolated yields and stereoselectivities. To evaluate the synthetic utility of the reaction products 4a-i, adduct 4g was converted to the 1,4-ene-diol 5g via dioxirane-mediated oxidative desilylation with allylic transposition, the allylic alcohol 6g via protodesilylation with allylic transposition, and the gamma-lactam 7g via chlorosulfonyl isocyanate-mediated cycloaddition. PMID:20540509

  11. 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.

  12. 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.

  13. Raspberry Ketone

    MedlinePlus

    Raspberry ketone is a chemical from red raspberries, as well as kiwifruit, peaches, grapes, apples, other berries, vegetables such as rhubarb, and the bark of yew, maple, and pine trees. People take raspberry ketone by mouth for ...

  14. Highly enantioselective reductive cyclization of acetylenic aldehydes via rhodium catalyzed asymmetric hydrogenation.

    PubMed

    Rhee, Jong Uk; Krische, Michael J

    2006-08-23

    Catalytic hydrogenation of acetylenic aldehydes 1a-12a using chirally modified cationic rhodium catalysts enables highly enantioselective reductive cyclization to afford cyclic allylic alcohols 1b-12b. Using an achiral hydrogenation catalyst, the chiral racemic acetylenic aldehydes 13a-15a engage in highly syn-diastereoselective reductive cyclizations to afford cyclic allylic alcohols 13b-15b. Ozonolysis of cyclization products 7b and 9b allows access to optically enriched alpha-hydroxy ketones 7c and 9c. Reductive cyclization of enyne 7a under a deuterium atmosphere provides the monodeuterated product deuterio-7b, consistent with a catalytic mechanism involving alkyne-carbonyl oxidative coupling followed by hydrogenolytic cleavage of the resulting oxametallacycle. These hydrogen-mediated transformations represent the first examples of the enantioselective reductive cyclization of acetylenic aldehydes. PMID:16910650

  15. Alcohol oxidase is a novel pathogenicity factor for Cladosporium fulvum, but aldehyde dehydrogenase is dispensable.

    PubMed

    Segers, G; Bradshaw, N; Archer, D; Blissett, K; Oliver, R P

    2001-03-01

    Cladosporiumfulvum is a mitosporic ascomycete pathogen of tomato. A study of fungal genes expressed during carbon starvation in vitro identified several genes that were up regulated during growth in planta. These included genes predicted to encode acetaldehyde dehydrogenase (Aldh1) and alcohol oxidase (Aox1). An Aldh1 deletion mutant was constructed. This mutant lacked all detectable ALDH activity, had lost the ability to grow with ethanol as a carbon source, but was unaffected in pathogenicity. Aox1 expression was induced by carbon starvation and during the later stages of infection. The alcohol oxidase enzyme activity has broadly similar properties (Km values, substrate specificity, pH, and heat stability) to yeast enzymes. Antibodies raised to Hansenula polymorpha alcohol oxidase (AOX) detected antigens in Western blots of starved C. fulvum mycelium and infected plant material. Antigen reacting with the antibodies was localized to organelles resembling peroxisomes in starved mycelium and infected plants. Disruption mutants of Aox1 lacked detectable AOX activity and had markedly reduced pathogenicity as assayed by two different measures of fungal growth. These results identify alcohol oxidase as a novel pathogenicity factor and are discussed in relation to peroxisomal metabolism of fungal pathogens during growth in planta. PMID:11277434

  16. Anesthetic effects changeable in habitual drinkers: Mechanistic drug interactions with neuro-active indoleamine-aldehyde condensation products associated with alcoholic beverage consumption.

    PubMed

    Tsuchiya, Hironori

    2016-07-01

    Clinicians often experience the reduced efficacy of general and local anesthetics and anesthesia-related drugs in habitual drinkers and chronic alcoholics. However, the mechanistic background underlying such anesthetic tolerance remains unclear. Biogenic indoleamines condense with alcohol-derived aldehydes during fermentation processes and under physiological conditions to produce neuro-active tetrahydro-β-carbolines and β-carbolines, many of which are contained not only in various alcoholic beverages but also in human tissues and body fluids. These indoleamine-aldehyde condensation products are increased in the human body because of their exogenous and endogenous supply enhanced by alcoholic beverage consumption. Since tetrahydro-β-carbolines and β-carbolines target receptors, ion channels and neuronal membranes which are common to anesthetic agents, we propose a hypothesis that they may pharmacodynamically interact at GABAA receptors, NMDA receptors, voltage-gated Na(+) channels and membrane lipid bilayers to attenuate anesthetics-induced positive allosteric GABAA receptor modulation, NMDA receptor antagonism, ion channel blockade and neuronal membrane modification, thereby affecting anesthetic efficacy. The condensation products may also cooperatively interact with ethanol that induces adaptive changes and cross-tolerance to anesthetics and with dopamine-aldehyde adducts that act on GABAA receptors and membrane lipids. Because tetrahydro-β-carbolines and β-carbolines are metabolized to lose or decrease their neuro-activities, induction of the relevant enzymes by habitual drinking could produce an inter-individual difference of drinkers in susceptibility to anesthetic agents. The present hypothesis would also provide a unified framework for different modes of anesthetic action, which are inhibited by neuro-active indoleamine-aldehyde condensation products associated with alcoholic beverage consumption. PMID:27241259

  17. Aldehyde dehydrogenase 2 (ALDH2) and alcohol dehydrogenase 1B (ADH1B) polymorphisms exacerbate bladder cancer risk associated with alcohol drinking: gene-environment interaction.

    PubMed

    Masaoka, Hiroyuki; Ito, Hidemi; Soga, Norihito; Hosono, Satoyo; Oze, Isao; Watanabe, Miki; Tanaka, Hideo; Yokomizo, Akira; Hayashi, Norio; Eto, Masatoshi; Matsuo, Keitaro

    2016-06-01

    Although a range of chemical exposures (cigarette smoking and occupational exposure) are recognized risk factors for the development of bladder cancer (BCa), many epidemiological studies have demonstrated that alcohol drinking is not associated with BCa risk. Aldehyde dehydrogenase 2 (ALDH2; rs671, Glu504Lys) and alcohol dehydrogenase 1B (ADH1B; rs1229984, His47Arg) polymorphisms impact the accumulation of acetaldehyde, resulting in an increased risk of various cancers. To date, however, no studies evaluating the association between BCa risk and alcohol drinking have considered these polymorphisms. Here, we conducted a matched case-control study to investigate whether ALDH2 and ADH1B polymorphisms influence BCa risk associated with alcohol drinking. Cases were 74 BCa patients and controls were 740 first-visit outpatients without cancer at Aichi Cancer Center Hospital between January 2001 and December 2005. Odds ratio (OR), 95% confidence interval (CI) and gene-environment interaction were assessed by conditional logistic regression analysis with adjustment for potential confounders. Results showed that ALDH2 Glu/Lys was associated with a significantly increased risk of BCa compared with Glu/Glu (OR 2.03, 95% CI 1.14-3.62, P = 0.017). In contrast, ALDH2 Glu/Lys showed no increase in risk among the stratum of never drinkers compared with Glu/Glu, indicating a gene-environment interaction. ADH1B His/Arg had an OR of 1.98 (1.20-3.24, P = 0.007) compared with His/His. ADH1B Arg+ showed a similar OR and 95% CI. Individuals with ALDH2 Glu/Lys and ADH1B Arg+ had the highest risk of BCa compared with ALDH2 Glu/Glu and ADH1B His/His [OR 4.00 (1.81-8.87), P = 0.001]. PMID:26992901

  18. E. coli metabolic protein aldehyde-alcohol dehydrogenase-E binds to the ribosome: a unique moonlighting action revealed.

    PubMed

    Shasmal, Manidip; Dey, Sandip; Shaikh, Tanvir R; Bhakta, Sayan; Sengupta, Jayati

    2016-01-01

    It is becoming increasingly evident that a high degree of regulation is involved in the protein synthesis machinery entailing more interacting regulatory factors. A multitude of proteins have been identified recently which show regulatory function upon binding to the ribosome. Here, we identify tight association of a metabolic protein aldehyde-alcohol dehydrogenase E (AdhE) with the E. coli 70S ribosome isolated from cell extract under low salt wash conditions. Cryo-EM reconstruction of the ribosome sample allows us to localize its position on the head of the small subunit, near the mRNA entrance. Our study demonstrates substantial RNA unwinding activity of AdhE which can account for the ability of ribosome to translate through downstream of at least certain mRNA helices. Thus far, in E. coli, no ribosome-associated factor has been identified that shows downstream mRNA helicase activity. Additionally, the cryo-EM map reveals interaction of another extracellular protein, outer membrane protein C (OmpC), with the ribosome at the peripheral solvent side of the 50S subunit. Our result also provides important insight into plausible functional role of OmpC upon ribosome binding. Visualization of the ribosome purified directly from the cell lysate unveils for the first time interactions of additional regulatory proteins with the ribosome. PMID:26822933

  19. E. coli metabolic protein aldehyde-alcohol dehydrogenase-E binds to the ribosome: a unique moonlighting action revealed

    PubMed Central

    Shasmal, Manidip; Dey, Sandip; Shaikh, Tanvir R.; Bhakta, Sayan; Sengupta, Jayati

    2016-01-01

    It is becoming increasingly evident that a high degree of regulation is involved in the protein synthesis machinery entailing more interacting regulatory factors. A multitude of proteins have been identified recently which show regulatory function upon binding to the ribosome. Here, we identify tight association of a metabolic protein aldehyde-alcohol dehydrogenase E (AdhE) with the E. coli 70S ribosome isolated from cell extract under low salt wash conditions. Cryo-EM reconstruction of the ribosome sample allows us to localize its position on the head of the small subunit, near the mRNA entrance. Our study demonstrates substantial RNA unwinding activity of AdhE which can account for the ability of ribosome to translate through downstream of at least certain mRNA helices. Thus far, in E. coli, no ribosome-associated factor has been identified that shows downstream mRNA helicase activity. Additionally, the cryo-EM map reveals interaction of another extracellular protein, outer membrane protein C (OmpC), with the ribosome at the peripheral solvent side of the 50S subunit. Our result also provides important insight into plausible functional role of OmpC upon ribosome binding. Visualization of the ribosome purified directly from the cell lysate unveils for the first time interactions of additional regulatory proteins with the ribosome. PMID:26822933

  20. Aldehyde Dehydrogenase 2 (ALDH2) Polymorphism and the Risk of Alcoholic Liver Cirrhosis among East Asians: A Meta-Analysis

    PubMed Central

    He, Lei; Luo, Hesheng

    2016-01-01

    Purpose The aldehyde dehydrogenase 2 (ALDH2) gene has been implicated in the development of alcoholic liver cirrhosis (ALC) in East Asians. However, the results are inconsistent. In this study, a meta-analysis was performed to assess the associations between the ALDH2 polymorphism and the risk of ALC. Materials and Methods Relevant studies were retrieved by searching PubMed, Web of Science, CNKI, Wanfang and Veipu databases up to January 10, 2015. Pooled odds ratio (OR) and 95% confidence interval (CI) were calculated using either the fixed- or random effects model. Results A total of twelve case-control studies included 1003 cases and 2011 controls were included. Overall, the ALDH2 polymorphism was associated with a decreased risk of ALC (*1/*2 vs. *1/*1: OR=0.78, 95% CI: 0.61–0.99). However, in stratification analysis by country, we failed to detect any association among Chinese, Korean or Japanese populations. Conclusion The pooled evidence suggests that ALDH2 polymorphism may be an important protective factor for ALC in East Asians. PMID:27189280

  1. Aldehyde-alcohol dehydrogenase and/or thiolase overexpression coupled with CoA transferase downregulation lead to higher alcohol titers and selectivity in Clostridium acetobutylicum fermentations.

    PubMed

    Sillers, Ryan; Al-Hinai, Mohab Ali; Papoutsakis, Eleftherios T

    2009-01-01

    Metabolic engineering (ME) of Clostridium acetobutylicum has led to increased solvent (butanol, acetone, and ethanol) production and solvent tolerance, thus demonstrating that further efforts have the potential to create strains of industrial importance. With recently developed ME tools, it is now possible to combine genetic modifications and thus implement more advanced ME strategies. We have previously shown that antisense RNA (asRNA)-based downregulation of CoA transferase (CoAT, the first enzyme in the acetone-formation pathway) results in increased butanol to acetone selectivity, but overall reduced butanol yields and titers. In this study the alcohol/aldehyde dehydrogenase (aad) gene (encoding the bifunctional protein AAD responsible for butanol and ethanol production from butyryl-CoA and acetyl-CoA, respectively) was expressed from the phosphotransbutyrylase (ptb) promoter to enhance butanol formation and selectivity, while CoAT downregulation was used to minimize acetone production. This led to early production of high alcohol (butanol plus ethanol) titers, overall solvent titers of 30 g/L, and a higher alcohol/acetone ratio. Metabolic flux analysis revealed the likely depletion of butyryl-CoA. In order to increase then the flux towards butyryl-CoA, we examined the impact of thiolase (THL, thl) overexpression. THL converts acetyl-CoA to acetoacetyl-CoA, the first step of the pathway from acetyl-CoA to butyryl-CoA, and thus, combining thl overexpression with aad overexpression decreased, as expected, acetate and ethanol production while increasing acetone and butyrate formation. thl overexpression in strains with asRNA CoAT downregulation did not significantly alter product formation thus suggesting that a more complex metabolic engineering strategy is necessary to enhance the intracellular butyryl-CoA pool and reduce the acetyl-CoA pool in order to achieve improved butanol titers and selectivity. PMID:18726959

  2. Regioselective alkene carbon-carbon bond cleavage to aldehydes and chemoselective alcohol oxidation of allylic alcohols with hydrogen peroxide catalyzed by [cis-Ru(II)(dmp)2(H2O)2]2+ (dmp = 2,9-dimethylphenanthroline).

    PubMed

    Kogan, Vladimir; Quintal, Miriam M; Neumann, Ronny

    2005-10-27

    [reaction: see text] [cis-Ru(II)(dmp)2(H2O)2]2+ (dmp = 2,9-dimethylphenanthroline) was found to be a selective oxidation catalyst using hydrogen peroxide as oxidant. Thus, primary alkenes were very efficiently oxidized via direct carbon-carbon bond cleavage to the corresponding aldehydes as an alternative to ozonolysis. Secondary alkenes were much less reactive, leading to regioselective oxidation of substrates such as 4-vinylcyclohexene and 7-methyl-1,6-octadiene at the terminal position. Primary allylic alcohols were chemoselectively oxidized to the corresponding allylic aldehydes, e.g., geraniol to citral. PMID:16235952

  3. Alcohol and Aldehyde Dehydrogenases Contribute to Sex-Related Differences in Clearance of Zolpidem in Rats

    PubMed Central

    Peer, Cody J.; Strope, Jonathan D.; Beedie, Shaunna; Ley, Ariel M.; Holly, Alesia; Calis, Karim; Farkas, Ronald; Parepally, Jagan; Men, Angela; Fadiran, Emmanuel O.; Scott, Pamela; Jenkins, Marjorie; Theodore, William H.; Sissung, Tristan M.

    2016-01-01

    Objectives: The recommended zolpidem starting dose was lowered in females (5 mg vs. 10 mg) since side effects were more frequent and severe than those of males; the mechanism underlying sex differences in pharmacokinetics (PK) is unknown. We hypothesized that such differences were caused by known sex-related variability in alcohol dehydrogenase (ADH) expression. Methods: Male, female, and castrated male rats were administered 2.6 mg/kg zolpidem, ± disulfiram (ADH/ALDH pathway inhibitor) to compare PK changes induced by sex and gonadal hormones. PK analyses were conducted in rat plasma and rat brain. Key findings: Sex differences in PK were evident: females had a higher CMAX (112.4 vs. 68.1 ug/L) and AUC (537.8 vs. 231.8 h∗ug/L) than uncastrated males. Castration induced an earlier TMAX (0.25 vs. 1 h), greater CMAX (109.1 vs. 68.1 ug/L), and a corresponding AUC increase (339.7 vs. 231.8 h∗ug/L). Administration of disulfiram caused more drastic CMAX and TMAX changes in male vs. female rats that mirrored the effects of castration on first-pass metabolism, suggesting that the observed PK differences may be caused by ADH/ALDH expression. Brain concentrations paralleled plasma concentrations. Conclusion: These findings indicate that sex differences in zolpidem PK are influenced by variation in the expression of ADH/ALDH due to gonadal androgens. PMID:27574509

  4. Selective oxidation of alcohols using photoactive VO@g-C3N4.

    EPA Science Inventory

    A photoactive VO@g-C3N4 catalyst has been developed for the selective oxidation of alcohols to the corresponding aldehydes and ketones. The visible light mediated activity of the catalyst could be attributed to photoactive graphitic carbon nitrides surface.

  5. Rh(III)-catalyzed dehydrogenative alkylation of (hetero)arenes with allylic alcohols, allowing aldol condensation to indenes.

    PubMed

    Shi, Zhuangzhi; Boultadakis-Arapinis, Mélissa; Glorius, Frank

    2013-07-25

    Efficient Rh(III)-catalyzed C-H activation of different classes of (hetero)arenes such as 2-phenylpyridine, indoles, aryl ketones and acetanilide and their dehydrogenative cross-coupling with allylic alcohols are described. Several important skeletons such as β-aryl aldehydes and ketones, 2-acetylindenes, 3,4-dihydro-1H-quinolin-2-one and quinoline could be produced using this protocol. PMID:23765402

  6. Alcohol Dehydrogenase-1B (rs1229984) and Aldehyde Dehydrogenase-2 (rs671) Genotypes Are Strong Determinants of the Serum Triglyceride and Cholesterol Levels of Japanese Alcoholic Men

    PubMed Central

    Yokoyama, Akira; Yokoyama, Tetsuji; Matsui, Toshifumi; Mizukami, Takeshi; Kimura, Mitsuru; Matsushita, Sachio; Higuchi, Susumu; Maruyama, Katsuya

    2015-01-01

    Background Elevated serum triglyceride (TG) and high-density-lipoprotein cholesterol (HDL-C) levels are common in drinkers. The fast-metabolizing alcohol dehydrogenase-1B encoded by the ADH1B*2 allele (vs. ADH1B*1/*1 genotype) and inactive aldehyde dehydrogenase-2 encoded by the ALDH2*2 allele (vs. ALDH2*1/*1 genotype) modify ethanol metabolism and are prevalent (≈90% and ≈40%, respectively) in East Asians. We attempted to evaluate the associations between the ADH1B and ALDH2 genotypes and lipid levels in alcoholics. Methods The population consisted of 1806 Japanese alcoholic men (≥40 years) who had undergone ADH1B and ALDH2 genotyping and whose serum TG, total cholesterol, and HDL-C levels in the fasting state had been measured within 3 days after admission. Results High serum levels of TG (≥150 mg/dl), HDL-C (>80 mg/dl), and low-density-lipoprotein cholesterol (LDL-C calculated by the Friedewald formula ≥140 mg/dl) were observed in 24.3%, 16.8%, and 15.6%, respectively, of the subjects. Diabetes, cirrhosis, smoking, and body mass index (BMI) affected the serum lipid levels. Multivariate analysis revealed that the presence of the ADH1B*2 allele and the active ALDH2*1/*1 genotype increased the odds ratio (OR; 95% confidence interval) for a high TG level (2.22 [1.67–2.94] and 1.39 [0.99–1.96], respectively), and decreased the OR for a high HDL-C level (0.37 [0.28–0.49] and 0.51 [0.37–0.69], respectively). The presence of the ADH1B*2 allele decreased the OR for a high LDL-C level (0.60 [0.45–0.80]). The ADH1B*2 plus ALDH2*1/*1 combination yielded the highest ORs for high TG levels and lowest OR for a high HDL-C level. The genotype effects were more prominent in relation to the higher levels of TG (≥220 mg/dl) and HDL-C (≥100 mg/dl). Conclusions The fast-metabolizing ADH1B and active ALDH2, and especially a combination of the two were strongly associated with higher serum TG levels and lower serum HDL-C levels of alcoholics. The fast

  7. Synthesis of a-Alkylated Ketones via Tandem Acceptorless Dehydrogenation/a-Alkylation from Secondary and Primary Alcohols Catalyzed by Metal-Ligand Bifunctional Iridium Complex [Cp*Ir(2,2'-bpyO)(H2O)].

    PubMed

    Wang, Rongzhou; Ma, Juan; Li, Feng

    2015-11-01

    A new strategy for the synthesis of α-alkylated ketones via tandem acceptorless dehydrogenation/α-alkylation from secondary and primary alcohols was proposed and accomplished. In the presence of metal-ligand bifunctional iridium complex [Cp*Ir(2,2'-bpyO)(H2O)], various desirable products were obtained in high yields. Compared with previous methods for the direct dehydrogenative coupling of secondary alcohols with primary alcohols to α-alkylated ketones, this protocol has obvious advantages including complete selectivity for α-alkylated ketones and more environmentally benign conditions. Notably, the study also exhibited the potential to develop tandem reactions catalyzed using a metal-ligand bifunctional iridium complex. PMID:26428210

  8. 27 CFR 21.117 - Methyl isobutyl ketone.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Methyl isobutyl ketone. 21.117 Section 21.117 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL FORMULAS FOR DENATURED ALCOHOL AND RUM Specifications for Denaturants § 21.117 Methyl isobutyl ketone. (a)...

  9. 27 CFR 21.117 - Methyl isobutyl ketone.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Methyl isobutyl ketone. 21.117 Section 21.117 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL FORMULAS FOR DENATURED ALCOHOL AND RUM Specifications for Denaturants § 21.117 Methyl isobutyl ketone. (a)...

  10. I86A/C295A mutant secondary alcohol dehydrogenase from Thermoanaerobacter ethanolicus has broadened substrate specificity for aryl ketones.

    PubMed

    Nealon, Christopher M; Welsh, Travis P; Kim, Chang Sup; Phillips, Robert S

    2016-09-15

    Thermoanaerobacter ethanolicus secondary alcohol dehydrogenase (SADH) reduces aliphatic ketones according to Prelog's Rule, with binding pockets for small and large substituents. It was shown previously that the I86A mutant SADH reduces acetophenone, which is not a substrate of wild-type SADH, to give the anti-Prelog R-product (Musa, M. M.; Lott, N.; Laivenieks, M.; Watanabe, L.; Vieille, C.; Phillips, R. S. ChemCatChem2009, 1, 89-93.). However, I86A SADH did not reduce aryl ketones with substituents larger than fluorine. We have now expanded the small pocket of the active site of I86A SADH by mutation of Cys-295 to alanine to allow reaction of substituted acetophenones. As predicted, the double mutant I86A/C295A SADH has broadened substrate specificity for meta-substituted, but not para-substituted, acetophenones. However, the increase of the substrate specificity of I86A/C295A SADH is accompanied by a decrease in the kcat/Km values of acetophenones, possibly due to the substrates fitting loosely inside the more open active site. Nevertheless, I86A/C295A SADH gives high conversions and very high enantiomeric excess of the anti-Prelog R-alcohols from the tested substrates. PMID:27495738

  11. Characterization of the Saccharomyces cerevisiae YMR318C (ADH6) gene product as a broad specificity NADPH-dependent alcohol dehydrogenase: relevance in aldehyde reduction.

    PubMed Central

    Larroy, Carol; Fernández, M Rosario; González, Eva; Parés, Xavier; Biosca, Josep A

    2002-01-01

    YMR318C represents an open reading frame from Saccharomyces cerevisiae with unknown function. It possesses a conserved sequence motif, the zinc-containing alcohol dehydrogenase (ADH) signature, specific to the medium-chain zinc-containing ADHs. In the present study, the YMR318C gene product has been purified to homogeneity from overexpressing yeast cells, and found to be a homodimeric ADH, composed of 40 kDa subunits and with a pI of 5.0-5.4. The enzyme was strictly specific for NADPH and was active with a wide variety of substrates, including aliphatic (linear and branched-chain) and aromatic primary alcohols and aldehydes. Aldehydes were processed with a 50-fold higher catalytic efficiency than that for the corresponding alcohols. The highest k(cat)/K(m) values were found with pentanal>veratraldehyde > hexanal > 3-methylbutanal >cinnamaldehyde. Taking into consideration the substrate specificity and sequence characteristics of the YMR318C gene product, we have proposed this gene to be called ADH6. The disruption of ADH6 was not lethal for the yeast under laboratory conditions. Although S. cerevisiae is considered a non lignin-degrading organism, the catalytic activity of ADHVI can direct veratraldehyde and anisaldehyde, arising from the oxidation of lignocellulose by fungal lignin peroxidases, to the lignin biodegradation pathway. ADHVI is the only S. cerevisiae enzyme able to significantly reduce veratraldehyde in vivo, and its overexpression allowed yeast to grow under toxic concentrations of this aldehyde. The enzyme may also be involved in the synthesis of fusel alcohols. To our knowledge this is the first NADPH-dependent medium-chain ADH to be characterized in S. cerevisiae. PMID:11742541

  12. Ketones urine test

    MedlinePlus

    Ketone bodies - urine; Urine ketones; Ketoacidosis - urine ketones test; Diabetic ketoacidosis - urine ketones test ... Urine ketones are usually measured as a "spot test." This is available in a test kit that ...

  13. 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

  14. 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

  15. Raspberry Ketone

    MedlinePlus

    Natural Medicines Comprehensive Database rates effectiveness based on scientific evidence according to the following scale: Effective, Likely ... keep in mind that there is no reliable scientific evidence that raspberry ketone improves weight loss when ...

  16. Pd/C-catalyzed aerobic oxidative esterification of alcohols and aldehydes: a highly efficient microwave-assisted green protocol.

    PubMed

    Caporaso, Marina; Cravotto, Giancarlo; Georgakopoulos, Spyros; Heropoulos, George; Martina, Katia; Tagliapietra, Silvia

    2014-01-01

    We herein describe an environmentally friendly microwave-assisted oxidative esterification of alcohols and aldehydes in the presence of molecular oxygen and a heterogeneous catalysis (Pd/C, 5 mol %). This efficient and ligandless conversion procedure does not require the addition of an organic hydrogen acceptor. The reaction rate is strongly enhanced by mild dielectric heating. Furthermore, it is a versatile green procedure which generally enables the isolation of esters to be carried out by simple filtration in almost quantitative yields. PMID:24991300

  17. Pd/C-catalyzed aerobic oxidative esterification of alcohols and aldehydes: a highly efficient microwave-assisted green protocol

    PubMed Central

    Caporaso, Marina; Georgakopoulos, Spyros; Heropoulos, George; Martina, Katia; Tagliapietra, Silvia

    2014-01-01

    Summary We herein describe an environmentally friendly microwave-assisted oxidative esterification of alcohols and aldehydes in the presence of molecular oxygen and a heterogeneous catalysis (Pd/C, 5 mol %). This efficient and ligandless conversion procedure does not require the addition of an organic hydrogen acceptor. The reaction rate is strongly enhanced by mild dielectric heating. Furthermore, it is a versatile green procedure which generally enables the isolation of esters to be carried out by simple filtration in almost quantitative yields. PMID:24991300

  18. Green, Catalytic Oxidation of Alcohols in Water

    NASA Astrophysics Data System (ADS)

    ten Brink, Gerd-Jan; Arends, Isabel W. C. E.; Sheldon, Roger A.

    2000-03-01

    Alcohol oxidations are typically performed with stoichiometric reagents that generate heavy-metal waste and are usually run in chlorinated solvents. A water-soluble palladium(II) bathophenanthroline complex is a stable recyclable catalyst for the selective aerobic oxidation of a wide range of alcohols to aldehydes, ketones, and carboxylic acids in a biphasic water-alcohol system. The use of water as a solvent and air as the oxidant makes the reaction interesting from both an economic and environmental point of view.

  19. 27 CFR 21.117 - Methyl isobutyl ketone.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Methyl isobutyl ketone. 21.117 Section 21.117 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS FORMULAS FOR DENATURED ALCOHOL AND RUM Specifications for Denaturants § 21.117 Methyl isobutyl ketone. (a)...

  20. 27 CFR 21.117 - Methyl isobutyl ketone.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Methyl isobutyl ketone. 21.117 Section 21.117 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS FORMULAS FOR DENATURED ALCOHOL AND RUM Specifications for Denaturants § 21.117 Methyl isobutyl ketone. (a)...

  1. 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.

  2. Tryptophan in Alcoholism Treatment II:  Inhibition of the Rat Liver Mitochondrial Low Km Aldehyde Dehydrogenase Activity, Elevation of Blood Acetaldehyde Concentration and Induction of Aversion to Alcohol by Combined Administration of Tryptophan and Benserazide

    PubMed Central

    Badawy, Abdulla A.-B.; Bano, Samina; Steptoe, Alex

    2011-01-01

    Aims: The aims were to provide proofs of mechanism and principle by establishing the ability of the amino acid L-tryptophan (Trp) combined with the kynureninase inhibitor benserazide (BSZ) to inhibit the liver mitochondrial low Km aldehyde dehydrogenase (ALDH) activity after administration and in vivo and to induce aversion to alcohol. Methods: Trp, BSZ or both were administered to male Wistar rats and ALDH activity was determined both in vitro in liver homogenates and in vivo (by measuring acetaldehyde accumulation in blood after ethanol administration). Alcohol consumption was studied in an aversion model in rats and in alcohol-preferring C57 mice. Results: Combined administration of Trp + BSZ, but neither compound alone, produced a strong inhibition of ALDH activity and an increase in blood acetaldehyde concentration after ethanol, and induced aversion to alcohol in rats and decreased preference in mice. Another kynureninase inhibitor, carbidopa, induced aversion to alcohol by itself, which was reversed by Trp co-administration. Conclusions: The present results establish a prior art for the use of a combination of Trp plus BSZ in the treatment of alcoholism by aversion, which merits rapid clinical development. PMID:21896551

  3. Single crystal-to-single crystal irreversible transformation from a discrete vanadium(V)-alcoholate to an aldehydic-vanadium(IV) oligomer.

    PubMed

    Chatterjee, Pabitra Baran; Audhya, Anandalok; Bhattacharya, Subhajit; Abtab, Sk Md Towsif; Bhattacharya, Kisholoy; Chaudhury, Muktimoy

    2010-11-17

    An unprecedented single crystal-to-single crystal transformation occurs when a binuclear oxovanadium(V) compound [V(V)(2)O(2)(L)(2)] 1 involving 2,6-bis(hydroxymethyl)-p-cresol (H(3)L) as a bridging ligand is exposed simultaneously to white light and aerial oxygen to generate an oligomeric compound [V(IV)(2)O(2)(L*)(2)] 2 (H(2)L* is 3-hydroxymethyl-5-methylsalicylaldehyde). Each vanadium(V) center in 1 is reduced to vanadium(IV) in 2 at the expense of a two-electron alcohol-to-aldehyde oxidation in the coordinated ligand. The additional electron being released is possibly consumed by molecular oxygen to generate hydrogen peroxide. PMID:20964328

  4. In vivo ethanol elimination in man, monkey and rat: A lack of relationship between the ethanol metabolism and the hepatic activities of alcohol and aldehyde dehydrogenases

    SciTech Connect

    Zorzano, A. ); Herrera, E. )

    1990-01-01

    The in vivo ethanol elimination in human subjects, monkeys and rats was investigated after an oral ethanol dosage. After 0.4 g. ethanol/kg of body weight, ethanol elimination was much slower in human subjects than in monkeys. In order to detect a rise in monkey plasma ethanol concentrations as early as observed in human subjects, ethanol had to be administered at a dose of 3 g/kg body weight. Ethanol metabolism in rats was also much faster than in human subjects. However, human liver showed higher alcohol dehydrogenase activity and higher low Km aldehyde dehydrogenase activity than rat liver. Thus, our data suggest a lack of relationship between hepatic ethanol-metabolizing activities and the in vivo ethanol elimination rate.

  5. The substrate tolerance of alcohol oxidases.

    PubMed

    Pickl, Mathias; Fuchs, Michael; Glueck, Silvia M; Faber, Kurt

    2015-08-01

    Alcohols are a rich source of compounds from renewable sources, but they have to be activated in order to allow the modification of their carbon backbone. The latter can be achieved via oxidation to the corresponding aldehydes or ketones. As an alternative to (thermodynamically disfavoured) nicotinamide-dependent alcohol dehydrogenases, alcohol oxidases make use of molecular oxygen but their application is under-represented in synthetic biotransformations. In this review, the mechanism of copper-containing and flavoprotein alcohol oxidases is discussed in view of their ability to accept electronically activated or non-activated alcohols and their propensity towards over-oxidation of aldehydes yielding carboxylic acids. In order to facilitate the selection of the optimal enzyme for a given biocatalytic application, the substrate tolerance of alcohol oxidases is compiled and discussed: Substrates are classified into groups (non-activated prim- and sec-alcohols; activated allylic, cinnamic and benzylic alcohols; hydroxy acids; sugar alcohols; nucleotide alcohols; sterols) together with suitable alcohol oxidases, their microbial source, relative activities and (stereo)selectivities. PMID:26153139

  6. Acceptorless Dehydrogenative Cyclization of o-Aminobenzyl Alcohols with Ketones to Quinolines in Water Catalyzed by Water-Soluble Metal-Ligand Bifunctional Catalyst [Cp*(6,6'-(OH)2bpy)(H2O)][OTf]2.

    PubMed

    Wang, Rongzhou; Fan, Hongjun; Zhao, Wei; Li, Feng

    2016-08-01

    The strategy for acceptorless dehydrogenative cyclization of o-aminobenzyl alcohols with ketones to quinolines in water has been accomplished. In the presence of [Cp*Ir(6,6'-(OH)2bpy)(H2O)][OTf]2, a series of desirable products were obtained in high yields. Notably, this research exhibits the potential for the construction of heterocycles via acceptorless dehydrogenative reactions in water catalyzed by water-soluble metal-ligand bifunctional catalysts. PMID:27400132

  7. Sulfoximine-mediated syntheses of optically active alcohols. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Stark, C. J., Jr.

    1978-01-01

    Several routes are described for the production of optically active secondary and tertiary alcohols. In all cases, the asymmetry emanates from the use of (+)-(S)-N,S-dimethyl-S-phenyl-sulfoximine (1) at some point in the variation of the diastereomers. One route relies upon the separation of the diastereomers produced from the condensation of (+)-(S)-(N-methylphenyl-sulfonimidoyl) methyllithium with prochiral aldehydes and ketones. Subsequent carbon-sulfur bond cleavage of the separated diastereomeric beta-hydroxysulfoximines yields optically active alcohols. Alternatively, beta-hydroxysulfoximines were produced from the reduction of chiral beta-ketosulfoximines. The reductions were most successfully achieved with diborane generated externally and bubbled into a toluene solution of the ketone at -78 C. Optically active alcohols were also produced from prochiral ketones by reduction with diborane or lithium aluminum hydride complexes of resolved diastereomers of beta-hydroxysulfoximines.

  8. Reliability of a flushing questionnaire and the ethanol patch test in screening for inactive aldehyde dehydrogenase-2 and alcohol-related cancer risk.

    PubMed

    Yokoyama, A; Muramatsu, T; Ohmori, T; Kumagai, Y; Higuchi, S; Ishii, H

    1997-12-01

    Molecular epidemiology of esophageal and upper aerodigestive tract cancers revealed that alcohol is more carcinogenic in persons with inactive aldehyde dehydrogenase-2 (ALDH2) than in those with active ALDH2. A simple questionnaire has been developed to screen for the facial flushing that occurs in persons with inactive ALDH2 when they drink even a single glass of beer. In this study, 266 of 284 consecutive male Japanese clinic patients (age > or = 50 years) completed the flushing questionnaire, and 239 underwent the ethanol patch test (a cutaneous model for the flushing response). Blinded genotyping showed inactive ALDH2 for 94.4% (102 of 108) of subjects who reported always flushing (early in their drinking history or currently) and for 47.7% (21 of 44) of those who reported sometimes flushing, whereas 95.6% (109 of 114) of subjects reporting that they never exhibited facial flushing had active ALDH2. When all three categories of flushing (current always, former always, and sometimes) were collapsed into one, the questionnaire's sensitivity and specificity for identifying inactive ALDH2 were 96.1 and 79.0%, respectively, compared with 72.4 and 71.4% for the ethanol patch test. The results suggest the utility of this simple flushing questionnaire in daily practice, as well as large-scale studies to assess cancer risks associated with drinking and ALDH2 and for activities aimed at preventing alcohol-related cancer. PMID:9419411

  9. Association of Genetically Determined Aldehyde Dehydrogenase 2 Activity with Diabetic Complications in Relation to Alcohol Consumption in Japanese Patients with Type 2 Diabetes Mellitus: The Fukuoka Diabetes Registry.

    PubMed

    Idewaki, Yasuhiro; Iwase, Masanori; Fujii, Hiroki; Ohkuma, Toshiaki; Ide, Hitoshi; Kaizu, Shinako; Jodai, Tamaki; Kikuchi, Yohei; Hirano, Atsushi; Nakamura, Udai; Kubo, Michiaki; Kitazono, Takanari

    2015-01-01

    Aldehyde dehydrogenase 2 (ALDH2) detoxifies aldehyde produced during ethanol metabolism and oxidative stress. A genetic defect in this enzyme is common in East Asians and determines alcohol consumption behaviors. We investigated the impact of genetically determined ALDH2 activity on diabetic microvascular and macrovascular complications in relation to drinking habits in Japanese patients with type 2 diabetes mellitus. An ALDH2 single-nucleotide polymorphism (rs671) was genotyped in 4,400 patients. Additionally, the relationship of clinical characteristics with ALDH2 activity (ALDH2 *1/*1 active enzyme activity vs. *1/*2 or *2/*2 inactive enzyme activity) and drinking habits (lifetime abstainers vs. former or current drinkers) was investigated cross-sectionally (n = 691 in *1/*1 abstainers, n = 1,315 in abstainers with *2, n = 1,711 in *1/*1 drinkers, n = 683 in drinkers with *2). The multiple logistic regression analysis for diabetic complications was adjusted for age, sex, current smoking habits, leisure-time physical activity, depressive symptoms, diabetes duration, body mass index, hemoglobin A1c, insulin use, high-density lipoprotein cholesterol, systolic blood pressure and renin-angiotensin system inhibitors use. Albuminuria prevalence was significantly lower in the drinkers with *2 than that of other groups (odds ratio [95% confidence interval (CI)]: *1/*1 abstainers as the referent, 0.94 [0.76-1.16] in abstainers with *2, 1.00 [0.80-1.26] in *1/*1 drinkers, 0.71 [0.54-0.93] in drinkers with *2). Retinal photocoagulation prevalence was also lower in drinkers with ALDH2 *2 than that of other groups. In contrast, myocardial infarction was significantly increased in ALDH2 *2 carriers compared with that in ALDH2 *1/*1 abstainers (odds ratio [95% CI]: *1/*1 abstainers as the referent, 2.63 [1.28-6.13] in abstainers with *2, 1.89 [0.89-4.51] in *1/*1 drinkers, 2.35 [1.06-5.79] in drinkers with *2). In summary, patients with type 2 diabetes and ALDH2 *2 displayed a

  10. Association of Genetically Determined Aldehyde Dehydrogenase 2 Activity with Diabetic Complications in Relation to Alcohol Consumption in Japanese Patients with Type 2 Diabetes Mellitus: The Fukuoka Diabetes Registry

    PubMed Central

    Idewaki, Yasuhiro; Iwase, Masanori; Fujii, Hiroki; Ohkuma, Toshiaki; Ide, Hitoshi; Kaizu, Shinako; Jodai, Tamaki; Kikuchi, Yohei; Hirano, Atsushi; Nakamura, Udai; Kubo, Michiaki; Kitazono, Takanari

    2015-01-01

    Aldehyde dehydrogenase 2 (ALDH2) detoxifies aldehyde produced during ethanol metabolism and oxidative stress. A genetic defect in this enzyme is common in East Asians and determines alcohol consumption behaviors. We investigated the impact of genetically determined ALDH2 activity on diabetic microvascular and macrovascular complications in relation to drinking habits in Japanese patients with type 2 diabetes mellitus. An ALDH2 single-nucleotide polymorphism (rs671) was genotyped in 4,400 patients. Additionally, the relationship of clinical characteristics with ALDH2 activity (ALDH2 *1/*1 active enzyme activity vs. *1/*2 or *2/*2 inactive enzyme activity) and drinking habits (lifetime abstainers vs. former or current drinkers) was investigated cross-sectionally (n = 691 in *1/*1 abstainers, n = 1,315 in abstainers with *2, n = 1,711 in *1/*1 drinkers, n = 683 in drinkers with *2). The multiple logistic regression analysis for diabetic complications was adjusted for age, sex, current smoking habits, leisure-time physical activity, depressive symptoms, diabetes duration, body mass index, hemoglobin A1c, insulin use, high-density lipoprotein cholesterol, systolic blood pressure and renin-angiotensin system inhibitors use. Albuminuria prevalence was significantly lower in the drinkers with *2 than that of other groups (odds ratio [95% confidence interval (CI)]: *1/*1 abstainers as the referent, 0.94 [0.76–1.16] in abstainers with *2, 1.00 [0.80–1.26] in *1/*1 drinkers, 0.71 [0.54–0.93] in drinkers with *2). Retinal photocoagulation prevalence was also lower in drinkers with ALDH2 *2 than that of other groups. In contrast, myocardial infarction was significantly increased in ALDH2 *2 carriers compared with that in ALDH2 *1/*1 abstainers (odds ratio [95% CI]: *1/*1 abstainers as the referent, 2.63 [1.28–6.13] in abstainers with *2, 1.89 [0.89–4.51] in *1/*1 drinkers, 2.35 [1.06–5.79] in drinkers with *2). In summary, patients with type 2 diabetes and ALDH2 *2

  11. Ketones blood test

    MedlinePlus

    ... Ketones - serum; Nitroprusside test; Ketone bodies - serum; Ketones - blood ... A blood sample is needed. ... When the needle is inserted to draw blood, some people feel slight ... there may be some throbbing or a slight bruise. This soon ...

  12. Inhibition of human alcohol and aldehyde dehydrogenases by aspirin and salicylate: assessment of the effects on first-pass metabolism of ethanol.

    PubMed

    Lee, Shou-Lun; Lee, Yung-Pin; Wu, Min-Li; Chi, Yu-Chou; Liu, Chiu-Ming; Lai, Ching-Long; Yin, Shih-Jiun

    2015-05-01

    Previous studies have reported that aspirin significantly reduced the first-pass metabolism (FPM) of ethanol in humans thereby increasing adverse effects of alcohol. The underlying causes, however, remain poorly understood. Alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH), principal enzymes responsible for metabolism of ethanol, are complex enzyme families that exhibit functional polymorphisms among ethnic groups and distinct tissue distributions. We investigated the inhibition profiles by aspirin and its major metabolite salicylate of ethanol oxidation by recombinant human ADH1A, ADH1B1, ADH1B2, ADH1B3, ADH1C1, ADH1C2, ADH2, and ADH4, and acetaldehyde oxidation by ALDH1A1 and ALDH2, at pH 7.5 and 0.5 mM NAD(+). Competitive inhibition pattern was found to be a predominant type among the ADHs and ALDHs studied, although noncompetitive and uncompetitive inhibitions were also detected in a few cases. The inhibition constants of salicylate for the ADHs and ALDHs were considerably lower than that of aspirin with the exception of ADH1A that can be ascribed to a substitution of Ala-93 at the bottom of substrate pocket as revealed by molecular docking experiments. Kinetic inhibition equation-based simulations show at higher therapeutic levels of blood plasma salicylate (1.5 mM) that the decrease of activities at 2-10 mM ethanol for ADH1A/ADH2 and ADH1B2/ADH1B3 are predicted to be 75-86% and 31-52%, respectively, and that the activity decline for ALDH1A1 and ALDH2 at 10-50 μM acetaldehyde to be 62-73%. Our findings suggest that salicylate may substantially inhibit hepatic FPM of alcohol at both the ADH and ALDH steps when concurrent intaking aspirin. PMID:25772736

  13. Rhodium-catalyzed Asymmetric Hydrogenation of α-Dehydroamino Ketones: A General Approach to Chiral α-amino Ketones.

    PubMed

    Gao, Wenchao; Wang, Qingli; Xie, Yun; Lv, Hui; Zhang, Xumu

    2016-01-01

    Rhodium/DuanPhos-catalyzed asymmetric hydrogenation of aliphatic α-dehydroamino ketones has been achieved and afforded chiral α-amino ketones in high yields and excellent enantioselectives (up to 99 % ee), which could be reduced further to chiral β-amino alcohols by LiAlH(tBuO)3 with good yields. This protocol provides a readily accessible route for the synthesis of chiral α-amino ketones and chiral β-amino alcohols. PMID:26425824

  14. Conducting polymer blends: Polypyrrole and polythiophene blends with polystyrene, polycarbonate resin, poly(vinyl alcohol) and poly(vinyl methyl ketone)

    SciTech Connect

    Wang, H.L.

    1992-01-01

    Various aromatic compounds can be polymerized by electrochemical oxidation in solution containing a supporting electrolyte. Most studies have been devoted to polypyrrole and polythiophene. In situ doping during electrochemical polymerization yields free standing conductive polymer film. One major approach to making conducting polymer blends is electrochemical synthesis after coating the host polymer on a platinum electrode. In the electrolysis of pyrrole or thiophene monomer, using (t-Bu[sub 4]N)BF[sub 4] as supporting electrolyte, and acetonitrile as solvent, monomer can diffuse through the polymer film, to produce a polypyrrole or polythiophene blend in the film. Doping occurs along with polymerization to form a conducting polymer alloy. The strongest molecular interaction in polymers, and one that is central to phase behavior, is hydrogen bonding. This mixing at the molecular level enhances the degree of miscibility between two polymers and results in macroscopic properties indicative of single phase behavior. In this dissertation, the authors describes the syntheses of conducting polymer blends: polypyrrole and polythiophene blends with polystyrene, poly(bisphenol-A-carbonate), polyvinyl alcohol and poly(vinyl methyl ketone). The syntheses are performed both electrochemically and chemically. Characterization of these blends was carried out by Fourier Transform Infrared spectroscopy, Differential Scanning Calorimetry, Thermogravimetric Analysis, Scanning Electron Microscopy, and X-ray diffraction. Percolating threshold conductivities occur from 7% to 20% for different polymer blends. The low threshold conductivity is attributed to blend homogeneity enhanced by hydrogen bonding between the carbonyl group in the insulating polymer and the N-H group in polypyrrole. Thermal stability, environmental stability, mechanical properties, crystallinity and morphological structure are also discussed. The authors have also engaged in the polymerization of imidazoles.

  15. I2/Aqueous TBHP-Catalyzed Coupling of Amides with Methylarenes/Aldehydes/Alcohols: Metal-Free Synthesis of Imides.

    PubMed

    Aruri, Hariprasad; Singh, Umed; Kumar, Sanjay; Kushwaha, Manoj; Gupta, Ajai Prakash; Vishwakarma, Ram A; Singh, Parvinder Pal

    2016-08-01

    We present a metal-free method for the synthesis of imides by the direct coupling of NH-amides with methylarenes under iodine/aqueous TBHP conditions. The optimized conditions worked very well with benzaldehydes and benzyl alcohol and furnished the corresponding imides in good to excellent yields. A series of control and radical scavenger experiments were also performed, which suggested the involvement of radical pathways. The labeling experiment in the presence of (18)O-labeled H2O suggested water as a source of oxygen in the imides. PMID:27434140

  16. Metabolism of trans, trans-muconaldehyde, a cytotoxic metabolite of benzene, in mouse liver by alcohol dehydrogenase Adh1 and aldehyde reductase AKR1A4

    SciTech Connect

    Short, Duncan M.; Lyon, Robert; Watson, David G.; Barski, Oleg A.; McGarvie, Gail; Ellis, Elizabeth M. . E-mail: Elizabeth.ellis@strath.ac.uk

    2006-01-15

    The reductive metabolism of trans, trans-muconaldehyde, a cytotoxic metabolite of benzene, was studied in mouse liver. Using an HPLC-based stopped assay, the primary reduced metabolite was identified as 6-hydroxy-trans, trans-2,4-hexadienal (OH/CHO) and the secondary metabolite as 1,6-dihydroxy-trans, trans-2,4-hexadiene (OH/OH). The main enzymes responsible for the highest levels of reductase activity towards trans, trans-muconaldehyde were purified from mouse liver soluble fraction first by Q-sepharose chromatography followed by either blue or red dye affinity chromatography. In mouse liver, trans, trans-muconaldehyde is predominantly reduced by an NADH-dependent enzyme, which was identified as alcohol dehydrogenase (Adh1). Kinetic constants obtained for trans, trans-muconaldehyde with the native Adh1 enzyme showed a V {sub max} of 2141 {+-} 500 nmol/min/mg and a K {sub m} of 11 {+-} 4 {mu}M. This enzyme was inhibited by pyrazole with a K {sub I} of 3.1 {+-} 0.57 {mu}M. Other fractions were found to contain muconaldehyde reductase activity independent of Adh1, and one enzyme was identified as the NADPH-dependent aldehyde reductase AKR1A4. This showed a V {sub max} of 115 nmol/min/mg and a K {sub m} of 15 {+-} 2 {mu}M and was not inhibited by pyrazole.

  17. Asymmetric reduction of ketones with recombinant E. coli whole cells in neat substrates.

    PubMed

    Jakoblinnert, Andre; Mladenov, Radoslav; Paul, Albert; Sibilla, Fabrizio; Schwaneberg, Ulrich; Ansorge-Schumacher, Marion B; de María, Pablo Domínguez

    2011-11-28

    The asymmetric reduction of ketones is performed by using lyophilized whole cells in neat substrates with defined water activity (a(w)). Ketones and alcohols prone to be unstable in aqueous media can now be converted via biocatalysis. PMID:22005469

  18. 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

  19. 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

  20. Cooperative catalysis of metal and O-H···O/sp3-C-H···O two-point hydrogen bonds in alcoholic solvents: Cu-catalyzed enantioselective direct alkynylation of aldehydes with terminal alkynes.

    PubMed

    Ishii, Takaoki; Watanabe, Ryo; Moriya, Toshimitsu; Ohmiya, Hirohisa; Mori, Seiji; Sawamura, Masaya

    2013-09-27

    Catalyst-substrate hydrogen bonds in artificial catalysts usually occur in aprotic solvents, but not in protic solvents, in contrast to enzymatic catalysis. We report a case in which ligand-substrate hydrogen-bonding interactions cooperate with a transition-metal center in alcoholic solvents for enantioselective catalysis. Copper(I) complexes with prolinol-based hydroxy amino phosphane chiral ligands catalytically promoted the direct alkynylation of aldehydes with terminal alkynes in alcoholic solvents to afford nonracemic secondary propargylic alcohols with high enantioselectivities. Quantum-mechanical calculations of enantiodiscriminating transition states show the occurrence of a nonclassical sp(3)-C-H···O hydrogen bond as a secondary interaction between the ligand and substrate, which results in highly directional catalyst-substrate two-point hydrogen bonding. PMID:23955688

  1. 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

  2. Beyond ketonization: selective conversion of carboxylic acids to olefins over balanced Lewis acid–base pairs

    SciTech Connect

    Baylon, Rebecca A. L.; Sun, Junming; Martin, Kevin J.; Venkitasubramanian, Padmesh; Wang, Yong

    2016-01-01

    Dwindling petroleum reserves combined with increased energy demand and political factors encouraging an increase in energy independence have led to a large amount of research on sustainable alternatives. To this end, biomass conversion has been recognized as themost readily viable technology to produce biofuel concerning our reliance on liquid fuels for transportation and has the advantage of being easily integrated into our heavy use of combustion engines. The interest in biomass conversion has also resulted in reduced costs and a greater abundance of bio-oil, a mixture of hundreds of oxygenates including alcohols, aldehydes, carboxylic acids, and ketones. However, the presence of carboxylic acids in bio-oil derived from lignocellulose pyrolysis leads to low pH, instability, and corrosiveness. In addition, carboxylic acids (i.e. acetic acid) can also be produced via fermentation of sugars. This can be accomplished by a variety of homoacetogenic microorganisms that can produce acetic acid with 100% carbon yield.

  3. Cofactor Specificity of the Bifunctional Alcohol and Aldehyde Dehydrogenase (AdhE) in Wild-Type and Mutant Clostridium thermocellum and Thermoanaerobacterium saccharolyticum

    PubMed Central

    Zheng, Tianyong; Olson, Daniel G.; Tian, Liang; Bomble, Yannick J.; Himmel, Michael E.; Lo, Jonathan; Hon, Shuen; Shaw, A. Joe; van Dijken, Johannes P.

    2015-01-01

    ABSTRACT Clostridium thermocellum and Thermoanaerobacterium saccharolyticum are thermophilic bacteria that have been engineered to produce ethanol from the cellulose and hemicellulose fractions of biomass, respectively. Although engineered strains of T. saccharolyticum produce ethanol with a yield of 90% of the theoretical maximum, engineered strains of C. thermocellum produce ethanol at lower yields (∼50% of the theoretical maximum). In the course of engineering these strains, a number of mutations have been discovered in their adhE genes, which encode both alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) enzymes. To understand the effects of these mutations, the adhE genes from six strains of C. thermocellum and T. saccharolyticum were cloned and expressed in Escherichia coli, the enzymes produced were purified by affinity chromatography, and enzyme activity was measured. In wild-type strains of both organisms, NADH was the preferred cofactor for both ALDH and ADH activities. In high-ethanol-producing (ethanologen) strains of T. saccharolyticum, both ALDH and ADH activities showed increased NADPH-linked activity. Interestingly, the AdhE protein of the ethanologenic strain of C. thermocellum has acquired high NADPH-linked ADH activity while maintaining NADH-linked ALDH and ADH activities at wild-type levels. When single amino acid mutations in AdhE that caused increased NADPH-linked ADH activity were introduced into C. thermocellum and T. saccharolyticum, ethanol production increased in both organisms. Structural analysis of the wild-type and mutant AdhE proteins was performed to provide explanations for the cofactor specificity change on a molecular level. IMPORTANCE This work describes the characterization of the AdhE enzyme from different strains of C. thermocellum and T. saccharolyticum. C. thermocellum and T. saccharolyticum are thermophilic anaerobes that have been engineered to make high yields of ethanol and can solubilize components of

  4. 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

  5. Laboratory Studies of Aedes aegypti Attraction to Ketones, Sulfides, and Primary Chloroalkanes Tested Alone and in Combination with L-Lactic Acid.

    PubMed

    Bernier, Ulrich R; Kline, Daniel L; Allan, Sandra A; Barnard, Donald R

    2015-03-01

    The attraction of female Aedes aegypti to single compounds and binary compositions containing L-lactic acid and an additional saturated compound from a set of ketones, sulfides, and chloroalkanes was studied using a triple-cage dual-port olfactometer. These chemical classes were studied because of their structural relation to acetone, dimethyl disulfide, and dichloromethane, which have all been reported to synergize attraction to L-lactic acid. Human odors, carbon dioxide, and the binary mixture of L-lactic acid and CO₂served as controls for comparison of attraction responses produced by the binary mixtures. All tested mixtures that contained chloroalkanes attracted mosquitoes at synergistic levels, as did L-lactic acid and CO₂. Synergism was less frequent in mixtures of L-lactic acid with sulfides and ketones; in the case of ketones, synergistic attraction was observed only for L-lactic acid combined with acetone or butanone. Suppression or inhibition of attraction response was observed for combinations that contained ketones of C7-C12 molecular chain length (optimum in the C8-C10 range). This inhibition effect is similar to that observed previously for specific ranges of carboxylic acids, aldehydes, and alcohols. PMID:25843177

  6. 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

  7. 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 ethyl alcohol and gasoline substituted for pure gasoline as a fuel in many Brazilian vehicles. Consequently, the concentrations of volatile organic compounds (VOCs) such as ketones, other organic compounds, and particularly aldehydes increased in many Brazilian cities. The current study aims to investigate whether formaldehyde, acetaldehyde, or mixtures of both impair lung function, morphology, inflammatory and redox responses at environmentally relevant concentrations. For such purpose, C57BL/6 mice were exposed to either medical compressed air or to 4 different mixtures of formaldehyde and acetaldehyde. Eight hours later animals were anesthetized, paralyzed and lung mechanics and morphology, inflammatory cells and IL-1β, KC, TNF-α, IL-6, CCL2, MCP-1 contents, superoxide dismutase and catalalase activities were determined. The extra pulmonary respiratory tract was also analyzed. No differences could be detected between any exposed and control groups. In conclusion, no morpho-functional alterations were detected in exposed mice in relation to the control group. PMID:27102012

  8. 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

  9. Alcohol

    MedlinePlus

    ... How Can I Help a Friend Who Cuts? Alcohol KidsHealth > For Teens > Alcohol Print A A A ... you can make an educated choice. What Is Alcohol? Alcohol is created when grains, fruits, or vegetables ...

  10. A reusable unsupported rhenium nanocrystalline catalyst for acceptorless dehydrogenation of alcohols through γ-C-H activation.

    PubMed

    Yi, Jing; Miller, Jeffrey T; Zemlyanov, Dmitry Y; Zhang, Ruihong; Dietrich, Paul J; Ribeiro, Fabio H; Suslov, Sergey; Abu-Omar, Mahdi M

    2014-01-13

    Rhenium nanocrystalline particles (Re NPs), of 2 nm size, were prepared from NH4ReO4 under mild conditions in neat alcohol. The unsupported Re NPs convert secondary and benzylic alcohols to ketones and aldehydes, respectively, through catalytic acceptorless dehydrogenation (AD). The oxidant- and acceptor-free neat dehydrogenation of alcohols to obtain dihydrogen gas is a green and atom-economical process for making carbonyl compounds. Secondary aliphatic alcohols give quantitative conversion and yield. Transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Re K-edge X-ray absorption near-edge structure (XANES), and X-ray absorption fine structure (EXAFS) data confirmed the characterization of the Re NPs as metallic rhenium with surface oxidation to rhenium(IV) oxide (ReO2). Isotope labeling experiments revealed a novel γ-CH activation mechanism for AD of alcohols. PMID:24282107

  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. A General, Practical Triethylborane-Catalyzed Reduction of Carbonyl Functions to Alcohols.

    PubMed

    Peng, Dongjie; Zhang, Mintao; Huang, Zheng

    2015-10-12

    A combination of the abundant and low-cost triethylborane and sodium alkoxide generates a highly efficient catalyst for reduction of esters, as well as ketones and aldehydes, to alcohols using an inexpensive hydrosilane under mild conditions. The catalyst system exhibits excellent chemoselectivity and a high level of functional group tolerance. Mechanistic studies revealed a resting state of sodium triethylalkoxylborate that is the product of the reaction of BEt3 with sodium alkoxide. This borate species reacts with hydrosilane to form NaBEt3 H, which rapidly reduces esters. PMID:26332613

  15. Identifying a Highly Active Copper Catalyst for KA(2) Reaction of Aromatic Ketones.

    PubMed

    Cai, Yujuan; Tang, Xinjun; Ma, Shengming

    2016-02-12

    The well-established A(3) coupling reaction of terminal alkynes, aldehydes, and amines provides the most straightforward approach to propargylic amines. However, the related reaction of ketones, especially aromatic ketones, is still a significant challenge. A highly efficient catalytic protocol has been developed for the coupling of aromatic ketones with amines and terminal alkynes, in which Cu(I) , generated in situ from the reduction of CuBr2 with sodium ascorbate, has been identified as the highly efficient catalyst. Since propargylic amines are versatile synthetic intermediates and important units in pharmaceutical products, such an advance will greatly stimulate research interest involving the previously unavailable propargylic amines. PMID:26660459

  16. Alcohol

    MedlinePlus

    ... Text Size: A A A Listen En Español Alcohol Wondering if alcohol is off limits with diabetes? Most people with diabetes can have a moderate amount of alcohol. Research has shown that there can be some ...

  17. Alcohol

    MedlinePlus

    If you are like many Americans, you drink alcohol at least occasionally. For many people, moderate drinking ... risky. Heavy drinking can lead to alcoholism and alcohol abuse, as well as injuries, liver disease, heart ...

  18. Hydrogenation of Aldehydes Catalyzed by an Available Ruthenium Complex.

    PubMed

    Tan, Xuefeng; Wang, Guozhen; Zhu, Ziyue; Ren, Conghui; Zhou, Jinping; Lv, Hui; Zhang, Xiaoyong; Chung, Lung Wa; Zhang, Lina; Zhang, Xumu

    2016-04-01

    A readily available ruthenium(II) catalyst was developed for the catalytic hydrogenation of aldehydes with a TON (turnover number) up to 340000. It can be performed without base and solvent, showing highly industrial potential. High chemoselectivity can be achieved in the presence of alkenyl and ketone groups. Further application of this protocol in glucose reduction showed good efficiency. Theoretical studies revealed that the rate-determining step is the hydrogenation step, not the carboxylate-assisted H2 activation step. PMID:26974348

  19. Ergot alkaloid biosynthesis in Aspergillus fumigatus: conversion of chanoclavine-I to chanoclavine-I aldehyde catalyzed by a short-chain alcohol dehydrogenase FgaDH.

    PubMed

    Wallwey, Christiane; Matuschek, Marco; Li, Shu-Ming

    2010-02-01

    Ergot alkaloids are toxins and important pharmaceuticals which are produced biotechnologically on an industrial scale. A putative gene fgaDH has been identified in the biosynthetic gene cluster of fumigaclavine C, an ergot alkaloid of the clavine-type. The deduced gene product FgaDH comprises 261 amino acids with a molecular mass of about 27.8 kDa and contains the conserved motifs of classical short-chain dehydrogenases/reductases (SDRs), but shares no worth mentioning sequence similarity with SDRs and other known proteins. The coding region of fgaDH consisting of two exons was amplified by PCR from a cDNA library of Aspergillus fumigatus, cloned into pQE60 and overexpressed in E. coli. The soluble tetrameric His(6)-FgaDH was purified to apparent homogeneity and characterized biochemically. It has been shown that FgaDH catalyzes the oxidation of chanoclavine-I in the presence of NAD(+) resulting in the formation of chanoclavine-I aldehyde, which was unequivocally identified by NMR and MS analyzes. Therefore, FgaDH functions as a chanoclavine-I dehydrogenase and represents a new group of short-chain dehydrogenases. K (M) values for chanoclavine-I and NAD(+) were determined at 0.27 and 1.1 mM, respectively. The turnover number was 0.38 s(-1). PMID:20039019

  20. Methyl isobutyl ketone (MIBK)

    Integrated Risk Information System (IRIS)

    Methyl Isobutyl Ketone ( MIBK ) ; CASRN 108 - 10 - 1 ; Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for

  1. Methyl ethyl ketone (MEK)

    Integrated Risk Information System (IRIS)

    Methyl ethyl ketone ( MEK ) ( CASRN 78 - 93 - 3 ) Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Nonc

  2. Alcohol

    MedlinePlus

    ... Got Homework? Here's Help White House Lunch Recipes Alcohol KidsHealth > For Kids > Alcohol Print A A A Text Size What's in ... What Is Alcoholism? Say No en español El alcohol Getting the Right Message "Hey, who wants a ...

  3. Rhodium-Catalyzed Ketone Methylation Using Methanol Under Mild Conditions: Formation of α-Branched Products**

    PubMed Central

    Chan, Louis K M; Poole, Darren L; Shen, Di; Healy, Mark P; Donohoe, Timothy J

    2014-01-01

    The rhodium-catalyzed methylation of ketones has been accomplished using methanol as the methylating agent and the hydrogen-borrowing method. The sequence is notable for the relatively low temperatures that are required and for the ability of the reaction system to form α-branched products with ease. Doubly alkylated ketones can be prepared from methyl ketones and two different alcohols by using a sequential one-pot iridium- and rhodium-catalyzed process. PMID:24288297

  4. Highly efficient and direct heterocyclization of dipyridyl ketone to N,N-bidentate ligands

    NASA Technical Reports Server (NTRS)

    Wang, Jie; Dyers, Leon Jr; Mason, Richard Jr; Amoyaw, Prince; Bu, Xiu R.

    2005-01-01

    [reaction: see text] Reaction of various aromatic aldehydes with 2,2'-dipyridyl ketone and ammonium acetate in hot acetic acid provides ready access to a series of substituted 1-pyridylimidazo[1,5-a]pyridines, a class of ligands possessing an N,N-bidentate feature, in good yields.

  5. The partitioning of ketones between the gas and aqueous phases

    NASA Astrophysics Data System (ADS)

    Betterton, Eric A.

    Most ketones are not significantly hydrated; they therefore retain their chromophore and they could be photolytically degraded in solution yielding a variety of products including carboxylic acids, aldehydes and radicals. It is difficult to accurately model the partitioning of ketones between the gas phase and aqueous phase because of the lack suitable estimates of the Henry's Law constants; consequently the fate and environmental effects of ketones cannot be confidently predicted. Here we report the experimental determination of the Henry's Law constants of a series of ketones that has yielded a simple straight line equation to predict the Henry's Law constants of simple aliphatic ketones: log H ∗ =0.23Σσ ∗ + 1.51; where H ∗ is the effective Henry's Law constant (M atm -1, and Σσ ∗ is the Taft polar substituents constants. The results for 25°C are (M atm -1) CH 3COCH 3, 32; C 6H 5COCH 3, 110; CH 2ClCOCH 3, 59; CH 3COCOCH 3, 74; CF 3COCH 3, 138. Acetophenone appears to have an abnormally high H ∗. Most low molecular weight aliphatic ketones are predicted to characterized by H ∗⩾30 M atm -1 and therefore they are expected to be found in the aqueous phase at concentrations of ⩾5 - 0.5 μM (given a typical gas-phase concentration range of 1-10 ppbv). The expected rate of decomposition of ketones due to photolysis in hydrometers is briefly discussed.

  6. 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.

  7. Tetranuclear vanadium complex, (VO)(4)(hpic)(4): a recyclable catalyst for oxidation of benzyl alcohols with molecular oxygen.

    PubMed

    Kodama, Shintaro; Ueta, Yukihiro; Yoshida, Jun; Nomoto, Akihiro; Yano, Shigenobu; Ueshima, Michio; Ogawa, Akiya

    2009-11-28

    Vanadium(iv) complexes bearing 3-hydroxypicolinic acid (H(2)hpic) as ligands, VO(Hhpic)(2) (1) and the cyclic tetramer (VO)(4)(hpic)(4) (2), have excellent catalytic ability for the oxidation of a variety of primary and secondary benzyl alcohols with molecular oxygen in acetonitrile or protic solvents such as ethanol and water, affording the corresponding aldehydes and ketones, respectively. Construction of multi-nuclear complexes by the selection of ligands attains higher turnover numbers and recycling of the catalyst. PMID:19885511

  8. Enantioselective Reduction of Ketones and Imines Catalyzed by (CN-Box)Re(V)-Oxo Complexes

    PubMed Central

    Nolin, Kristine A.; Ahn, Richard W.; Kobayashi, Yusuke; Kennedy-Smith, Joshua J.

    2012-01-01

    The development and application of chiral, non-racemic Re(V)-oxo complexes to the enantioselective reduction of prochiral ketones is described. In addition to the enantioselective reduction of prochiral ketones, we report the application of these complexes to (1) a tandem Meyer-Schuster rearrangement/reduction to access enantioenriched allylic alcohols and (2) the enantioselective reduction of imines. PMID:20623567

  9. Polyfluorinated. cap alpha. ,. beta. -unsaturated ketons

    SciTech Connect

    Latypov, R.R.; Belogai, V.D.; Pashkevich, K.I.

    1986-07-10

    The ..cap alpha..,..beta..-unsaturated ketones (..cap alpha..,..beta..-UK), particularly those groups containing fluoroalkyl groups, are of interest as highly reactive compounds having two nonequivalent electrophilic centers. In the present investigation, by boiling polyfluorinated aldehydes with methylketones in glacial acetic acid, they have obtained for the first time the polyfluorinated ..beta..-hydroxy-ketones, the dehydration of which has been used to synthesize the corresponding polyfluorinated ..cap alpha..,..beta..-UK, and their structure and reactions with the nucleophiles NH/sub 3/, PhNH/sub 2/, MeOH have been studied. In the PMR spectra of the ..cap alpha..,..beta..-UK (X)-(XVI) two doublets of triplets are observed at 6.9 and 7.9 ppm, caused by the spin-spin coupling of the olefin protons with the CF/sub 2/ group of the substituent. For ..cap alpha..,..beta..-UK, apart from the cis-trans isomerism relative to the C=C bond, a rotational isomerism is possible, caused by rotation around the C-C single bond. The presence in the IR spectra of absorption bands from nonplanar torsion-deformation vibrations of C-H for a double bond (nu = 975-980 cm/sup -1/) and the high value of the spin-spin coupling constant of the olefin protons (J/sub HH/ = 15 Hz) indicate unambiguously the transconfiguration of the olefin protons.

  10. Alcohol

    MedlinePlus

    ... as well as injuries, liver disease, heart disease, cancer, and other health problems. It can also cause problems at home, at work, and with friends. NIH: National Institute on Alcohol Abuse and Alcoholism

  11. Mini-scale Oxidation/Reduction in Organic Laboratory Course: 4-Nitrobenzaldehyde/ 4-Nitrobenzyl Alcohol

    NASA Astrophysics Data System (ADS)

    Taber, Douglass F.; Wang, Yanong; Liehr, Sebastian

    1996-11-01

    Oxidation of an alcohol to the aldehyde or ketone, and corresponding reduction back to the alcohol, are two of the most common transformations of preparative organic chemistry. As such, they have a place in the undergraduate laboratory course. We have found the exercises currently available in laboratory texts to be deficient in several ways: the oxidized products [camphor, cyclohexanone] are volatile and difficult to isolate, and do not visualize on TLC. While camphor is a solid, it is difficult to isolate and crystallize. We have found a much more satisfactory combination in 4-nitrobenzyl alcohol and 4-nitrobenzaldehyde. both are crystalline, neither is volatile, and both are strongly UV-absorbing, so they visualize well on TLC.

  12. Alcoholism.

    ERIC Educational Resources Information Center

    Caliguri, Joseph P., Ed.

    This extensive annotated bibliography provides a compilation of documents retreived from a computerized search of the ERIC, Social Science Citation Index, and Med-Line databases on the topic of alcoholism. The materials address the following areas of concern: (1) attitudes toward alcohol users and abusers; (2) characteristics of alcoholics and…

  13. A HIGHLY STEREOSELECTIVE, NOVEL COUPLING REACTION BETWEEN ALKYNES WITH ALDEHYDES. (R828129)

    EPA Science Inventory

    In the presence of indium triflate or gallium chloride, a novel coupling between internal alkynes and aldehydes occurred to give unsaturated ketones and [4+1] annulation products.


    Graphical Abstrac...

  14. Stereoselective Reduction of Prochiral Ketones by Plant and Microbial Biocatalysts.

    PubMed

    Javidnia, K; Faghih-Mirzaei, E; Miri, R; Attarroshan, M; Zomorodian, K

    2016-01-01

    Chiral alcohols are the key chiral building blocks to many enantiomerically pure pharmaceuticals. The biocatalytic approach in asymmetric reduction of corresponding prochiral ketones to the preparation of these optically pure substances is one of the most promising routes. The stereoselective reduction of different kinds of prochiral ketones catalyzed by various plants and microorganisms was studied in this work. Benzyl acetoacetate, methyl 3-oxopentanoate, ethyl 3-oxopentanoate, and ethyl butyryl acetate were chosen as the model substrates for β-ketoesters. Benzoyl acetonitrile, 3-chloro propiophenone, and 1-acetyl naphthalene were chosen as aromatic aliphatic ketones. Finally, 2-methyl benzophenone and 4-chloro benzophenone were selected as diaryl ketones. Plant catalysis was conducted by Daucus carota, Brassica rapa, Brassica oleracea, Pastinaca sativa, and Raphnus sativus. For microbial catalysis, Aspergillus foetidus, Penicillum citrinum, Saccharomyces carlbergensis, Pichia fermentans, and Rhodotrula glutinis were chosen. Chiral alcohols were obtained in high yields and with optical purity. A superiority in the microorganisms' performance in the bioreduction of prochiral ketones was detected. Among microorganisms, Rhodotrula glutinis showed remarkable results with nearly all substrates and is proposed for future studies. PMID:27168684

  15. Stereoselective Reduction of Prochiral Ketones by Plant and Microbial Biocatalysts

    PubMed Central

    Javidnia, K.; Faghih-Mirzaei, E.; Miri, R.; Attarroshan, M.; Zomorodian, K.

    2016-01-01

    Chiral alcohols are the key chiral building blocks to many enantiomerically pure pharmaceuticals. The biocatalytic approach in asymmetric reduction of corresponding prochiral ketones to the preparation of these optically pure substances is one of the most promising routes. The stereoselective reduction of different kinds of prochiral ketones catalyzed by various plants and microorganisms was studied in this work. Benzyl acetoacetate, methyl 3-oxopentanoate, ethyl 3-oxopentanoate, and ethyl butyryl acetate were chosen as the model substrates for β-ketoesters. Benzoyl acetonitrile, 3-chloro propiophenone, and 1-acetyl naphthalene were chosen as aromatic aliphatic ketones. Finally, 2-methyl benzophenone and 4-chloro benzophenone were selected as diaryl ketones. Plant catalysis was conducted by Daucus carota, Brassica rapa, Brassica oleracea, Pastinaca sativa, and Raphnus sativus. For microbial catalysis, Aspergillus foetidus, Penicillum citrinum, Saccharomyces carlbergensis, Pichia fermentans, and Rhodotrula glutinis were chosen. Chiral alcohols were obtained in high yields and with optical purity. A superiority in the microorganisms' performance in the bioreduction of prochiral ketones was detected. Among microorganisms, Rhodotrula glutinis showed remarkable results with nearly all substrates and is proposed for future studies. PMID:27168684

  16. Quantification of the electrophilic reactivities of aldehydes, imines, and enones.

    PubMed

    Appel, Roland; Mayr, Herbert

    2011-06-01

    The rates of the epoxidation reactions of aldehydes, of the aziridination reactions of aldimines, and of the cyclopropanation reactions of α,β-unsaturated ketones with aryl-stabilized dimethylsulfonium ylides have been determined photometrically in dimethyl sulfoxide (DMSO). All of these sulfur ylide-mediated cyclization reactions as well as the addition reactions of stabilized carbanions to N-tosyl-activated aldimines have been shown to follow a second-order rate law, where the rate constants reflect the (initial) CC bond formation between nucleophile and electrophile. The derived second-order rate constants (log k(2)) have been combined with the known nucleophilicity parameters (N, s(N)) of the aryl-stabilized sulfur ylides 4a,b and of the acceptor-substituted carbanions 4c-h to calculate the electrophilicity parameters E of aromatic and aliphatic aldehydes (1a-i), N-acceptor-substituted aromatic aldimines (2a-e), and α,β-unsaturated ketones (3a-f) according to the linear free-energy relationship log k(2) = s(N)(N + E) as defined in J. Am. Chem. Soc.2001, 123, 9500-9512. The data reported in this work provide the first quantitative comparison of the electrophilic reactivities of aldehydes, imines, and simple Michael acceptors in DMSO with carbocations and cationic metal-π complexes within our comprehensive electrophilicity scale. PMID:21553901

  17. Solvent-free aerobic oxidation of hydrocarbons and alcohols with Pd@N-doped carbon from glucose.

    PubMed

    Zhang, Pengfei; Gong, Yutong; Li, Haoran; Chen, Zhirong; Wang, Yong

    2013-01-01

    The development of efficient systems for selective aerobic oxidation of hydrocarbons and alcohols to produce more functional compounds (aldehydes, ketones, acids or esters) with atmospheric air or molecular oxygen is a grand challenge for the chemical industry. Here we report the synthesis of palladium nanoparticles supported on novel nanoporous nitrogen-doped carbon, and their impressive performance in the controlled oxidation of hydrocarbons and alcohols with air. In terms of catalytic activity, these catalysts afford much higher turnover frequencies (up to 863 turnovers per hour for hydrocarbon oxidation and up to ~210,000 turnovers per hour for alcohol oxidation) than most reported palladium catalysts under the same reaction conditions. This work provides great potential for the application of ambient air and recyclable palladium catalysts in fine-chemical production with high activity. PMID:23481401

  18. SnAP-eX Reagents for the Synthesis of Exocyclic 3-Amino- and 3-Alkoxypyrrolidines and Piperidines from Aldehydes.

    PubMed

    Luescher, Michael U; Bode, Jeffrey W

    2016-06-01

    SnAP-eX (tin amine protocol, exocyclic heteroatoms) reagents allow the single-step transformation of aldehydes and ketones into 2,3-disubstituted pyrrolidines and piperidines containing exocyclic amine or alkoxy groups. These saturated N-heterocycles are of importance in modern drug discovery approaches and are prepared in moderate yields using an operationally simple protocol that is compatible with a range of functional groups and heterocyclic aldehydes. PMID:27192447

  19. Alcohol.

    ERIC Educational Resources Information Center

    Schibeci, Renato

    1996-01-01

    Describes the manufacturing of ethanol, the effects of ethanol on the body, the composition of alcoholic drinks, and some properties of ethanol. Presents some classroom experiments using ethanol. (JRH)

  20. One-Pot Synthesis of β-Acetamido Ketones Using Boric Acid at Room Temperature

    PubMed Central

    Karimi-Jaberi, Zahed; Mohammadi, Korosh

    2012-01-01

    β-acetamido ketones were synthesized in excellent yields through one-pot condensation reaction of aldehydes, acetophenones, acetyl chloride, and acetonitrile in the presence of boric acid as a solid heterogeneous catalyst at room temperature. It is the first successful report of boric acid that has been used as solid acid catalyst for the preparation of β-acetamido ketones. The remarkable advantages offered by this method are green catalyst, mild reaction conditions, simple procedure, short reaction times, and good-to-excellent yields of products. PMID:22666168

  1. Betaine aldehyde, betaine, and choline levels in rat livers during ethanol metabolism.

    PubMed

    Chern, M K; Gage, D A; Pietruszko, R

    2000-12-01

    Betaine aldehyde levels were determined in rat livers following 4 weeks of ethanol feeding, employing the Lieber-De Carli liquid diet. The results showed that the levels of betaine aldehyde are unaffected by alcohol feeding to rats. These levels in both experimental and control animals were found to be quite low, 5.5 nmol/g liver. Betaine aldehyde levels have not been determined previously in mammalian liver because of methodological difficulties. This investigation employed fast atom bombardment-mass spectroscopy to determine the levels of betaine aldehyde, betaine, and choline. The decrease in betaine levels following ethanol administration confirmed the results of other investigators. Choline levels determined during this investigation were lower than previously reported. The reason for starting this investigation was the fact that the enzyme that catalyzes betaine aldehyde dehydrogenation to betaine, which is distributed in both mitochondria and the cytoplasm, was found to also metabolize acetaldehyde with K(m) and V(max) values lower than those for betaine aldehyde. Thus, it appeared likely that the metabolism of acetaldehyde during ethanol metabolism might inhibit betaine aldehyde conversion to betaine and thereby result in decreased betaine levels (Barak et al., Alcohol 13: 395-398, 1996). The fact that betaine aldehyde levels in alcohol-fed animals were similar to those in controls demonstrates that competition between acetaldehyde and betaine aldehyde for the same enzyme does not occur. This complete lack of competition suggests that betaine aldehyde dehydrogenase in the mitochondrial matrix may totally metabolize betaine aldehyde to betaine without any involvement of cytoplasmic betaine aldehyde dehydrogenase. PMID:11077045

  2. 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

  3. Ketone bodies as signaling metabolites

    PubMed Central

    Newman, John C.; Verdin, Eric

    2014-01-01

    Traditionally, the ketone body β-hydroxybutyrate (βOHB) has been looked upon as a carrier of energy from liver to peripheral tissues during fasting or exercise. However, βOHB also signals via extracellular receptors and acts as an endogenous inhibitor of histone deacetylases (HDACs). These recent findings support a model in which βOHB functions to link the environment, in this case the diet, and gene expression via chromatin modifications. Here, we review the regulation and functions of ketone bodies, the relationship between ketone bodies and calorie restriction, and the implications of HDAC inhibition by the ketone body βOHB in the modulation of metabolism, and diseases of aging. PMID:24140022

  4. Alcohol conversion

    DOEpatents

    Wachs, Israel E.; Cai, Yeping

    2002-01-01

    Preparing an aldehyde from an alcohol by contacting the alcohol in the presence of oxygen with a catalyst prepared by contacting an intimate mixture containing metal oxide support particles and particles of a catalytically active metal oxide from Groups VA, VIA, or VIIA, with a gaseous stream containing an alcohol to cause metal oxide from the discrete catalytically active metal oxide particles to migrate to the metal oxide support particles and to form a monolayer of catalytically active metal oxide on said metal oxide support particles.

  5. A SeCSe-Pd(II) pincer complex as a highly efficient catalyst for allylation of aldehydes with allyltributyltin.

    PubMed

    Yao, Qingwei; Sheets, Matthew

    2006-07-01

    An air- and moisture-stable SeCSe-Pd(II) pincer complex was synthesized and found to catalyze the nucleophilic allylation of aldehydes with allyltributyltin. The allylation of a variety of aromatic and aliphatic aldehydes to give the corresponding homoallyl alcohols was performed at room temperature to 60 degrees C in yields ranging from 50% (for typical aliphatic aldehydes) to up to 97% (for aromatic aldehydes) using 5 x 10(-3) to 1 mol % of the Pd catalyst. NMR spectroscopic study indicated that a sigma-allylpalladium intermediate was formed and possibly functions as the nucleophilic species that undergoes addition to the aldehydes. PMID:16808533

  6. Green organocatalytic α-hydroxylation of ketones.

    PubMed

    Voutyritsa, Errika; Theodorou, Alexis; Kokotos, Christoforos G

    2016-06-28

    An efficient and green method for the α-hydroxylation of substituted ketones has been developed. This method includes the in situ conversion of various ketones into the corresponding silyl enol ethers and their oxidation to the corresponding α-hydroxy ketones. Two protocols have been established leading either to protected α-hydroxy carbonyls or free α-hydroxy ketones. Both procedures are easy to follow and lead to good to high yields for a variety of ketones. PMID:26867154

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  8. 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

  9. Scope and mechanism of the highly stereoselective metal-mediated domino aldol reactions of enolates with aldehydes.

    PubMed

    Cinar, M Emin; Engelen, Bernward; Panthöfer, Martin; Deiseroth, Hans-Jörg; Schlirf, Jens; Schmittel, Michael

    2016-01-01

    A one-pot transformation, which involves the reaction of ketones with aldehydes in the presence of metal halides to furnish tetrahydro-2H-pyran-2,4-diols in a highly diastereoselective manner, is investigated thoroughly by experiments and computations. The reaction was also successfully implemented on a flow micro reactor system. PMID:27340472

  10. Scope and mechanism of the highly stereoselective metal-mediated domino aldol reactions of enolates with aldehydes

    PubMed Central

    Engelen, Bernward; Panthöfer, Martin; Deiseroth, Hans-Jörg; Schlirf, Jens

    2016-01-01

    Summary A one-pot transformation, which involves the reaction of ketones with aldehydes in the presence of metal halides to furnish tetrahydro-2H-pyran-2,4-diols in a highly diastereoselective manner, is investigated thoroughly by experiments and computations. The reaction was also successfully implemented on a flow micro reactor system. PMID:27340472

  11. 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

  12. From ketones to esters by a Cu-catalyzed highly selective C(CO)-C(alkyl) bond cleavage: aerobic oxidation and oxygenation with air.

    PubMed

    Huang, Xiaoqiang; Li, Xinyao; Zou, Miancheng; Song, Song; Tang, Conghui; Yuan, Yizhi; Jiao, Ning

    2014-10-22

    The Cu-catalyzed aerobic oxidative esterification of simple ketones via C-C bond cleavage has been developed. Varieties of common ketones, even inactive aryl long-chain alkyl ketones, are selectively converted into esters. The reaction tolerates a wide range of alcohols, including primary and secondary alcohols, chiral alcohols with retention of the configuration, electron-deficient phenols, as well as various natural alcohols. The usage of inexpensive copper catalyst, broad substrate scope, and neutral and open air conditions make this protocol very practical. (18)O labeling experiments reveal that oxygenation occurs during this transformation. Preliminary mechanism studies indicate that two novel pathways are mainly involved in this process. PMID:25251943

  13. Iridium-Catalyzed Diastereoselective and Enantioselective Allylic Substitutions with Acyclic α-Alkoxy Ketones.

    PubMed

    Jiang, Xingyu; Chen, Wenyong; Hartwig, John F

    2016-05-01

    The asymmetric alkylation of acyclic ketones is a longstanding challenge in organic synthesis. Reported herein are diastereoselective and enantioselective allylic substitutions with acyclic α-alkoxy ketones catalyzed by a metallacyclic iridium complex to form products with contiguous stereogenic centers derived from the nucleophile and electrophile. These reactions occur between allyl methyl carbonates and unstabilized copper(I) enolates generated in situ from acyclic α-alkoxy ketones. The resulting products can be readily converted into enantioenriched tertiary alcohols and tetrahydrofuran derivatives without erosion of enantiomeric purity. PMID:27038004

  14. Metal-Catalysed Transfer Hydrogenation of Ketones.

    PubMed

    Štefane, Bogdan; Požgan, Franc

    2016-04-01

    We highlight recent developments of catalytic transfer hydrogenation of ketones promoted by transition metals, while placing it within its historical context. Since optically active secondary alcohols are important building blocks in fine chemicals synthesis, the focus of this review is devoted to chiral catalyst types which are capable of inducing high stereoselectivities. Ruthenium complexes still represent the largest part of the catalysts, but other metals (e.g. Fe) are rapidly penetrating this field. While homogeneous transfer hydrogenation catalysts in some cases approach enzymatic performance, the interest in heterogeneous catalysts is constantly growing because of their reusability. Despite excellent activity, selectivity and compatibility of metal complexes with a variety of functional groups, no universal catalysts exist. Development of future catalyst systems is directed towards reaching as high as possible activity with low catalyst loadings, using "greener" conditions, and being able to operate under mild conditions and in a highly selective manner for a broad range of substrates. PMID:27573143

  15. METHYL KETONE METABOLISM IN HYDROCARBON-UTILIZING MYCOBACTERIA

    PubMed Central

    Lukins, H. B.; Foster, J. W.

    1963-01-01

    Lukins, H. B. (University of Texas, Austin) and J. W. Foster. Methyl ketone metabolism in hydrocarbon-utilizing mycobacteria. J. Bacteriol. 85: 1074–1087. 1963.—Species of Mycobacterium especially M. smegmatis 422, produced the homologous methyl ketones during the oxidation of propane, n-butane, n-pentane, or n-hexane. A carrier-trapping experiment demonstrated the formation of 2-undecanone, as well as 1,11-undecanedioic acid, during the oxidation of undecane-1-C14. Aliphatic alkane-utilizing mycobacteria were able to grow at the expense of several aliphatic methyl ketones as sole sources of carbon. Other ketones which did not support growth were oxidized by resting bacterial suspensions. M. smegmatis 422 cells grown on propane or acetone were simultaneously adapted to oxidize both substrates, as well as n-propanol. n-Propanol cells were unadapted to propane or acetone. Acetone produced from propane in a medium enriched in D2O contained a negligible quantity of D, presumably eliminating propylene as an intermediate in the oxidation. Cells grown at the expense of alkanes or methyl ketones in the presence of O218 had a higher content of O18 than did cells grown on terminally oxidized compounds, e.g., primary alcohols or fatty acids. An oxygenase reaction is postulated for the attack on methyl ketones. Acetol was isolated and characterized as an oxidation product of acetone by M. smegmatis 422. Acetol-grown cells had a higher O18 content than did n-propanol cells, and its utilization appears to involve at least one oxygenase reaction. Acetol produced from acetone in the presence of O218 was not enriched in the isotope, indicating the occurrence of exchange reactions or of oxygenation reactions at a later stage in the assimilation of acetone and acetol. PMID:14043998

  16. Sugars, Alcohols, and Cometary Astrobiochemistry

    NASA Astrophysics Data System (ADS)

    Hudson, R. L.; Moore, M. H.; Gerakines, P. A.

    2004-12-01

    Radio and IR observations have revealed that a rich organic chemistry exists in comets and in a variety of interstellar regions. Among the organic molecules detected are acids, alcohols, aldehydes, ketones, and nitriles. The simplest sugar, glycolaldehyde, has been reported (Hollis et al., ApJ, 2000, 540, L107), as has an amino acid, glycine (Kuan et al., ApJ, 2003, 593, 848; but see Hollis et al., ApJ, 2003, 588, 353). Gas-phase reactions to produce many of these molecules are not well understood, and solid-phase chemistry is thought to make an important contribution. To better understand organic chemistry in cold cosmic environments, we have performed photo- and radiation chemical experiments on icy materials at 10 - 100 K. Gas-phase molecules are frozen in a vacuum chamber, and then exposed to either MeV protons or vacuum-UV photons to mimic cosmic-ray bombardment or cosmic-UV exposure, respectively. Changes in ice composition are followed in situ with IR spectroscopy. In this AGU presentation we will describe our latest results for glycolaldehyde, as well as a few prebiological organics. Solid-state IR spectra and reaction pathways will be presented, and predictions will be made for the chemical composition of selected Solar System objects. -- This research is funded through NASA's Planetary Atmospheres and SARA programs, and through the NASA Astrobiology Program under RTOP 344-53-51-01 to M. J. Mumma (NASA GSFC).

  17. A specific affinity reagent to distinguish aldehyde dehydrogenases and oxidases. Enzymes catalyzing aldehyde oxidation in an adult moth

    SciTech Connect

    Tasayco, M.L.; Prestwich, G.D. )

    1990-02-25

    Aldehyde dehydrogenase (ALDH) and oxidase (AO) enzymes from the tissue extracts of male and female tobacco budworm moth (Heliothis virescens) were identified after electrophoretic protein separation. AO activity was visualized using formazan- or horseradish peroxidase-mediated staining coupled to the AO-catalyzed oxidation of benzaldehyde. A set of six soluble AO enzymes with isoelectric points from pI 4.6 to 5.3 were detected primarily in the antennal extracts. Partially purified antennal AO enzymes also oxidized both (Z)-9-tetradecenal and (Z)-11-hexadecenal, the two major pheromone components of this moth. ALDH activity was detected using a tritium-labeled affinity reagent based on a known irreversible inhibitor of this enzyme. This labeled vinyl ketone, (3H)(Z)-1,11-hexadecadien-3-one, was synthesized and used to covalently modify the soluble ALDH enzymes from tissue extracts. Molecular subunits of potential ALDH enzymes were visualized in the fluorescence autoradiograms of sodium dodecyl sulfate-polyacrylamide gel electrophoresis-separated proteins of the antenna, head, and leg tissues. Covalent modification of these protein subunits decreased specifically in the presence of excess pheromone aldehyde or benzaldehyde. Labeled vinyl ketones are thus novel tools for the identification of molecular subunits of ALDH enzymes.

  18. 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

  19. Catalytic ionic hydrogenation of ketones using tungsten or molybdenum catalysts with increased lifetimes

    DOEpatents

    Bullock, R. Morris; Kimmich, Barbara F. M.; Fagan, Paul J.; Hauptman, Elisabeth

    2003-09-02

    The present invention is a process for the catalytic hydrogenation of ketones and aldehydes to alcohols at low temperatures and pressures using organometallic molybdenum and tungsten complexes and the catalyst used in the process. The reactants include a functional group which is selected from groups represented by the formulas R*(C.dbd.O)R' and R*(C.dbd.O)H, wherein R* and R' are selected from hydrogen or any alkyl or aryl group. The process includes reacting the organic compound in the presence of hydrogen and a catalyst to form a reaction mixture. The catalyst is prepared by reacting Ph.sub.3 C.sup.+ A.sup.- with a metal hydride. A.sup.- represents an anion and can be BF.sub.4.sup.-, PF.sub.6.sup.-, CF.sub.3 SO.sub.3.sup.- or Bar'.sub.4.sup.-, wherein Ar'=3,5-bis(trifluoromethyl)phenyl. The metal hydride is represented by the formula: HM(CO).sub.2 [.eta..sup.5 :.eta..sup.1 --C.sub.5 H.sub.4 (XH.sub.2).sub.n PR.sub.2 ] wherein M represents a molybdenum (Mo) atom or a tungsten (W) atom; X is a carbon atom, a silicon atom or a combination of carbon (C) and silicon (Si) atoms; n is any positive integer; R represents two hydrocarbon groups selected from H, an aryl group and an alkyl group, wherein both R groups can be the same or different. The metal hydride is reacted with Ph.sub.3 C.sup.+ A.sup.- either before reacting with the organic compound or in the reaction mixture.

  20. Catalytic ionic hydrogenation of ketones using tungsten or molybdenum organometallic species

    DOEpatents

    Voges, Mark; Bullock, R. Morris

    2000-01-01

    The present invention is a process for the catalytic hydrogenation of ketones and aldehydes to alcohols at low temperatures and pressures using organometallic molybdenum and tungsten complexes. The functional group is selected from groups represented by the formulas R(C.dbd.O)R' and R(C.dbd.O)H, wherein R and R' are selected from hydrogen or any alkyl or aryl group. The active catalyst for the process has the form: [CpM(CO).sub.2 (PR*.sub.3) L].sup.+ A.sup.-, where Cp=.eta..sup.5 -R.sup..tangle-solidup..sub.m C.sub.5 H.sub.5-m and R.sup..tangle-solidup. represents an alkyl group or a halogen (F, Cl, Br, I) or R.sup..tangle-solidup. =OR' (where R'=H, an alkyl group or an aryl group) or R.sup..tangle-solidup. =CO.sub.2 R' (where R'=H, an alkyl group or an aryl group) and m=0 to 5; M represents a molybdenum atom or a tungsten atom; R*.sub.3 represents three hydrocarbon groups selected from a cyclohexyl group (C.sub.6 H.sub.11), a methyl group (CH.sub.3), and a phenyl group (C.sub.6 H.sub.5) and all three R* groups can be the same or different or two of the three groups can be the same; L represents a ligand; and A.sup.- represents an anion. In another embodiment, one, two or three of the R* groups can be an OR*.

  1. 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

  2. Stereoselective titanium-mediated aldol reactions of a chiral lactate-derived ethyl ketone with ketones.

    PubMed

    Alcoberro, Sandra; Gómez-Palomino, Alejandro; Solà, Ricard; Romea, Pedro; Urpí, Fèlix; Font-Bardia, Mercè

    2014-01-17

    Aldol reactions of titanium enolates of lactate-derived ethyl ketone 1 with other ketones proceed in a very efficient and stereocontrolled manner provided that a further equivalent of TiCl4 is added to the reacting mixture. The scope of these reactions encompasses simple ketones such as acetone or cyclohexanone as well as other ketones that contain potential chelating groups such as pyruvate esters or α- and β-hydroxy ketones. PMID:24372372

  3. Pushing the limits of aminocatalysis: enantioselective transformations of α-branched β-ketocarbonyls and vinyl ketones by chiral primary amines.

    PubMed

    Zhang, Long; Fu, Niankai; Luo, Sanzhong

    2015-04-21

    Enantioselective α-functionalizations of carbonyl compounds are fundamental transformations for the asymmetric synthesis of organic compounds. One of the more recent developments along this line is in aminocatalysis, which leads to the direct α-functionalization of simple aldehydes and ketones. However, most of the advances have been achieved with linear aldehydes and ketones as substrates. Effective aminocatalysis with α-branched carbonyls, particularly α-branched ketones, has remained elusive. The primary difficulty arises from the space-demanding α-substituent, which impedes iminium/enamine formation. In 2005, synthetic organic chemists revived catalysis using primary amines, which brought new attention to these challenges, because of the conformational flexibility of primary amines. On the basis of early biomimetic studies by Hine, in 2007 we developed the bioinspired chiral primary amine catalysts featuring primary-tertiary diamines. This type of catalyst involves enamine/iminium catalysis, and we could apply this chemistry to all of the major types of ketones and aldehydes. In this Account, we present research from our laboratory that significantly expands aminocatalysis to include α-branched ketones such as β-ketocarbonyls and α-substituted vinyl ketones. Our primary amine catalysis methodology, when used alone or in conjunction with metal catalysts, provides convenient access to both enantiopure α-tertiary and quaternary ketones, structures that are not available via other approaches. Our mechanistic studies showed that acidic additives play the critical role in facilitating catalytic turnover, most likely by shuttling protons during the enamine/iminium tautomerizations. These additives are also critical to induce the desired stereochemistry via ammonium N-H hydrogen bonding. Proton transfer by shuttling is also stereoselective, resulting in enantioselective enamine protonation as observed in the reactions of α-substituted vinyl ketones. In

  4. 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

  5. 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

  6. Transition metal-catalyzed ketone-directed or mediated C-H functionalization.

    PubMed

    Huang, Zhongxing; Lim, Hee Nam; Mo, Fanyang; Young, Michael C; Dong, Guangbin

    2015-11-01

    Transition metal-catalyzed C-H functionalization has evolved into a prominent and indispensable tool in organic synthesis. While nitrogen, phosphorus and sulfur-based functional groups (FGs) are widely employed as effective directing groups (DGs) to control the site-selectivity of C-H activation, the use of common FGs (e.g. ketone, alcohol and amine) as DGs has been continuously pursued. Ketones are an especially attractive choice of DGs and substrates due to their prevalence in various molecules and versatile reactivity as synthetic intermediates. Over the last two decades, transition metal-catalyzed C-H functionalization that is directed or mediated by ketones has experienced vigorous growth. This review summarizes these advancements into three major categories: use of ketone carbonyls as DGs, direct β-functionalization, and α-alkylation/alkenylation with unactivated olefins and alkynes. Each of these subsections is discussed from the perspective of strategic design and reaction discovery. PMID:26185960

  7. Spacecraft Maximum Allowable Concentrations (SMACs) for C3 to C8 Aliphatic Saturated Aldehydes

    NASA Technical Reports Server (NTRS)

    Langford, Shannon D.

    2007-01-01

    Spacecraft maximum allowable concentrations (SMACs) for C3 to C8, straight-chain, aliphatic aldehydes have been previously assessed and have been documented in volume 4 of Spacecraft Maximum Allowable Concentrations for Selected Airborne Contaminants (James, 2000). These aldehydes as well as associated physical properties are shown in Table 1. The C3 to C8 aliphatic aldehydes can enter the habitable compartments and contaminate breathing air of spacecraft by several routes including incomplete oxidation of alcohols in the Environmental Control and Life Support System (ECLSS) air revitalization subsystem, as a byproduct of human metabolism, through materials off-gassing, or during food preparation. These aldehydes have been detected in the atmosphere of manned space vehicles in the past. Analysis performed by NASA of crew cabin air samples from the Russian Mir Space Station revealed the presence of C3 to C8 aldehydes at concentrations peaking at approximately 0.1 mg/cu m.

  8. Catalytic purification of wastewaters containing formaldehyde, methyl alcohol, and acetone

    SciTech Connect

    Rachkovskaya, L.N.; Anisiforov, G.I.; Levitskii, E.A.; Kundo, N.N.

    1982-01-10

    A catalytic method for purification of wastewaters containing alcohols, aldehydes, and ketones is described in the literature. A current of steam containing gaseous organic compounds is passed over a complete-oxidation catalyst at temperatures of 250-700/sup 0/C. The organic compounds are oxidized to carbon dioxide. The main drawback of this method is that the wastewater must be evaporated and the vapor heated to high temperatures, involving a high consumption of fuel. Methods of liquid-phase catalytic oxidation under pressure are free from this drawback. A patent describes liquid-phase oxidation of phenol, analine, nitrobenzene, glycol, and dimethylformamide at temperatures of 275-300/sup 0/C under air pressures up to 100 atm in presence of oxides of copper, chromium, and zinc; a metallic catalyst consisting of copper, chromium, and manganese; copper oxide deposited on magnesium silicate. In a contact time of 8-10 min the degree of oxidation is 90-99%. It is known that liquid-phase oxidation of formaldehyde without a catalyst at 200/sup 0/C and 120 atm with a contact time of 4 h results in 80% oxidation of formaldehyde to methyl formate undergoes 10% conversion into acetic acid, while methyl alcohol is not oxidized at all. In this communication we describe liquid-phase catalytic oxidation of model wastewater containing formaldehyde, methyl alcohol, and acetone at temperatures up to 250/sup 0/C and oxygen pressures up to 20 atm.

  9. Characterisation of aroma volatiles of indigenous alcoholic beverages: burukutu and pito.

    PubMed

    Onyenekwe, Paul C; Erhabor, Graham Osas; Akande, Sarah A

    2016-01-01

    Pito and burukutu are indigenous alcoholic beverages in Nigeria, and are fermentation products of Sorghum bicolor and Sorghum vulgare. The production is similar to that of beer, which involves steeping, malting, mashing and fermenting. A total of 30 volatile organic compounds were identified by gas chromatography. These compounds can be broadly grouped into alkanols, phenols, acids, esters, ketones and aldehydes. Although few acids are present, they are dominant (30.887% and 27.669%) and followed by esters (26.467% and 27.442%) in pito and burukutu, respectively. Alkanols constitute the next dominant group after acids and esters; however, ethanol was not identified as a constituent. The health and social implication of the constituents are explained. PMID:25894868

  10. Iron-Catalyzed Regioselective Transfer Hydrogenative Couplings of Unactivated Aldehydes with Simple Alkenes.

    PubMed

    Zheng, Yan-Long; Liu, Yan-Yao; Wu, Yi-Mei; Wang, Yin-Xia; Lin, Yu-Tong; Ye, Mengchun

    2016-05-17

    An FeBr3 -catalyzed reductive coupling of various aldehydes with alkenes that proceeds through a direct hydride transfer pathway has been developed. With (i) PrOH as the hydrogen donor under mild conditions, previously challenging coupling reactions of unactivated alkyl and aryl aldehydes with simple alkenes, such as styrene derivatives and α-olefins, proceeded smoothly to furnish a diverse range of functionalized alcohols with complete linear regioselectivity. PMID:27072872

  11. Garner’s aldehyde as a versatile intermediate in the synthesis of enantiopure natural products

    PubMed Central

    Passiniemi, Mikko

    2013-01-01

    Summary Since its introduction to the synthetic community in 1984, Garner’s aldehyde has gained substantial attention as a chiral intermediate for the synthesis of numerous amino alcohol derivatives. This review presents some of the most successful carbon chain elongation reactions, namely carbonyl alkylations and olefinations. The literature is reviewed with particular attention on understanding how to avoid the deleterious epimerization of the existing stereocenter in Garner’s aldehyde. PMID:24367429

  12. Substrate specificity of an aflatoxin-metabolizing aldehyde reductase.

    PubMed Central

    Ellis, E M; Hayes, J D

    1995-01-01

    The enzyme from rat liver that reduces aflatoxin B1-dialdehyde exhibits a unique catalytic specificity distinct from that of other aldo-keto reductases. This enzyme, designated AFAR, displays high activity towards dicarbonyl-containing compounds with ketone groups on adjacent carbon atoms; 9,10-phenanthrenequinone, acenaphthenequinone and camphorquinone were found to be good substrates. Although AFAR can also reduce aromatic and aliphatic aldehydes such as succinic semialdehyde, it is inactive with glucose, galactose and xylose. The enzyme also exhibits low activity towards alpha,beta-unsaturated carbonyl-containing compounds. Determination of the apparent Km reveals that AFAR has highest affinity for 9,10-phenanthrenequinone and succinic semialdehyde, and low affinity for glyoxal and DL-glyceraldehyde. PMID:8526867

  13. Ketone body metabolism and cardiovascular disease

    PubMed Central

    Cotter, David G.; Schugar, Rebecca C.

    2013-01-01

    Ketone bodies are metabolized through evolutionarily conserved pathways that support bioenergetic homeostasis, particularly in brain, heart, and skeletal muscle when carbohydrates are in short supply. The metabolism of ketone bodies interfaces with the tricarboxylic acid cycle, β-oxidation of fatty acids, de novo lipogenesis, sterol biosynthesis, glucose metabolism, the mitochondrial electron transport chain, hormonal signaling, intracellular signal transduction pathways, and the microbiome. Here we review the mechanisms through which ketone bodies are metabolized and how their signals are transmitted. We focus on the roles this metabolic pathway may play in cardiovascular disease states, the bioenergetic benefits of myocardial ketone body oxidation, and prospective interactions among ketone body metabolism, obesity, metabolic syndrome, and atherosclerosis. Ketone body metabolism is noninvasively quantifiable in humans and is responsive to nutritional interventions. Therefore, further investigation of this pathway in disease models and in humans may ultimately yield tailored diagnostic strategies and therapies for specific pathological states. PMID:23396451

  14. Highly enantioselective phenylacetylene addition to aromatic ketones catalyzed by cinchona alkaloid-aluminum complexes.

    PubMed

    Liu, Lei; Wang, Rui; Kang, Yong-Feng; Chen, Chao; Xu, Zhao-Qing; Zhou, Yi-Feng; Ni, Ming; Cai, Hua-Qing; Gong, Mao-Zhen

    2005-02-01

    The catalytic asymmetric addition of phenylacetylene to aromatic ketones is reported. The catalyst, generated from commercially available Cinchona alkaloids and industrially available triethylaluminum, gives the expected tertiary alcohols with good enantiomeric excess (70-89%) and yields (60-83%). No previous case has been reported successfully using triethylaluminum as a Lewis acid in the asymmetric alkynylation of carbonylic derivatives, and thus we provide a new method to obtain optically active tertiary propargyl alcohols. PMID:15675878

  15. Iridium Catalysts with f-Amphox Ligands: Asymmetric Hydrogenation of Simple Ketones.

    PubMed

    Wu, Weilong; Liu, Shaodong; Duan, Meng; Tan, Xuefeng; Chen, Caiyou; Xie, Yun; Lan, Yu; Dong, Xiu-Qin; Zhang, Xumu

    2016-06-17

    A series of modular and rich electronic tridentate ferrocene aminophosphoxazoline ligands (f-amphox) have been successfully developed and used in iridium-catalytic asymmetric hydrogenation of simple ketones to afford corresponding enantiomerically enriched alcohols under mild conditions with superb activities and excellent enantioselectivities (up to 1 000 000 TON, almost all products up to >99% ee, full conversion). The resulting chiral alcohols and their derivatives are important intermediates in pharmaceuticals. PMID:27257935

  16. Alkyne–Aldehyde Reductive C–C Coupling through Ruthenium-Catalyzed Transfer Hydrogenation: Direct Regio- and Stereoselective Carbonyl Vinylation to Form Trisubstituted Allylic Alcohols in the Absence of Premetallated Reagents

    PubMed Central

    Leung, Joyce C.; Patman, Ryan L.; Sam, Brannon

    2011-01-01

    Nonsymmetric 1,2-disubstituted alkynes engage in reductive coupling to a variety of aldehydes under the conditions of ruthenium-catalyzed transfer hydrogenation by employing formic acid as the terminal reductant and delivering the products of carbonyl vinylation with good to excellent levels of regioselectivity and with complete control of olefin stereochemistry. As revealed in an assessment of the ruthenium counterion, iodide plays an essential role in directing the regioselectivity of C–C bond formation. Isotopic labeling studies corroborate reversible catalytic propargyl C–H oxidative addition in advance of the C–C coupling, and demonstrate that the C–C coupling products do not experience reversible dehydrogenation by way of enone intermediates. This transfer hydrogenation protocol enables carbonyl vinylation in the absence of stoichiometric metallic reagents. PMID:21953608

  17. Alkyne-aldehyde reductive C-C coupling through ruthenium-catalyzed transfer hydrogenation: direct regio- and stereoselective carbonyl vinylation to form trisubstituted allylic alcohols in the absence of premetallated reagents.

    PubMed

    Leung, Joyce C; Patman, Ryan L; Sam, Brannon; Krische, Michael J

    2011-10-24

    Nonsymmetric 1,2-disubstituted alkynes engage in reductive coupling to a variety of aldehydes under the conditions of ruthenium-catalyzed transfer hydrogenation by employing formic acid as the terminal reductant and delivering the products of carbonyl vinylation with good to excellent levels of regioselectivity and with complete control of olefin stereochemistry. As revealed in an assessment of the ruthenium counterion, iodide plays an essential role in directing the regioselectivity of C-C bond formation. Isotopic labeling studies corroborate reversible catalytic propargyl C-H oxidative addition in advance of the C-C coupling, and demonstrate that the C-C coupling products do not experience reversible dehydrogenation by way of enone intermediates. This transfer hydrogenation protocol enables carbonyl vinylation in the absence of stoichiometric metallic reagents. PMID:21953608

  18. Use of the anti-Prelog stereospecific alcohol dehydrogenase from Leifsonia and Pseudomonas for producing chiral alcohols.

    PubMed

    Itoh, Nobuya

    2014-05-01

    The asymmetric reduction of ketones is one of the most promising processes for producing chiral alcohols. However, dehydrogenases or reductases that can catalyze the reduction of ketones to give anti-Prelog chiral alcohols have been limited to some NADP(+)/NADPH-dependent enzymes. Recently, we reported a novel NAD(+)/NADH-dependent alcohol dehydrogenase (ADH) from Leifsonia sp. and Pseudomonas ADH homologs from soil metagenomes. Moreover, we have established an efficient hydrogen-transfer bioreduction process with 2-propanol as a hydrogen donor using Leifsonia ADH. This review focuses on the recent development of novel ADHs for producing industrially useful anti-Prelog chiral alcohols from various ketones. PMID:24615386

  19. Asymmetric Propargylation of Ketones using Allenylboronates Catalyzed by Chiral Biphenols

    PubMed Central

    Barnett, David S.; Schaus, Scott E.

    2011-01-01

    Chiral biphenols catalyze the enantioselective asymmetric propargylation of ketones using allenylboronates. The reaction uses 10 mol % of 3,3′-Br2-BINOL as the catalyst and allenyldioxoborolane as the nucleophile, in the absence of solvent, and under microwave irradiation to afford the homopropargylic alcohol. The reaction products are obtained in good yields (60 – 98%) and high enantiomeric ratios (3:1 – 99:1). Diastereoselective propargylations using chiral racemic allenylboronates result in good diastereoselectivities (dr > 86:14) and enantioselectivities (er > 92:8) under the catalytic conditions. PMID:21732609

  20. Asymmetric propargylation of ketones using allenylboronates catalyzed by chiral biphenols.

    PubMed

    Barnett, David S; Schaus, Scott E

    2011-08-01

    Chiral biphenols catalyze the enantioselective asymmetric propargylation of ketones using allenylboronates. The reaction uses 10 mol % of 3,3'-Br(2)-BINOL as the catalyst and allenyldioxoborolane as the nucleophile, in the absence of solvent, and under microwave irradiation to afford the homopropargylic alcohol. The reaction products are obtained in good yields (60-98%) and high enantiomeric ratios (3:1-99:1). Diastereoselective propargylations using chiral racemic allenylboronates result in good diastereoselectivities (dr >86:14) and enantioselectivities (er >92:8) under the catalytic conditions. PMID:21732609

  1. Copper-catalyzed asymmetric hydrogenation of aryl and heteroaryl ketones.

    PubMed

    Krabbe, Scott W; Hatcher, Mark A; Bowman, Roy K; Mitchell, Mark B; McClure, Michael S; Johnson, Jeffrey S

    2013-09-01

    High throughput screening enabled the development of a Cu-based catalyst system for the asymmetric hydrogenation of prochiral aryl and heteroaryl ketones that operates at H2 pressures as low as 5 bar. A ligand combination of (R,S)-N-Me-3,5-xylyl-BoPhoz and tris(3,5-xylyl)phosphine provided benzylic alcohols in good yields and enantioselectivities. The electronic and steric characteristics of the ancillary triarylphosphine were important in determining both reactivity and selectivity. PMID:23980941

  2. EXTRACTION OF TETRAVALENT PLUTONIUM VALUES WITH METHYL ETHYL KETONE, METHYL ISOBUTYL KETONE ACETOPHENONE OR MENTHONE

    DOEpatents

    Seaborg, G.T.

    1961-08-01

    A process is described for extracting tetravalent plutonium from an aqueous acid solution with methyl ethyl ketone, methyl isobutyl ketone, or acetophenone and with the extraction of either tetravalent or hexavalent plutonium into menthone. (AEC)

  3. Mechanism of alcohol oxidation by dipicolinate vanadium(V): unexpected role of pyridine.

    PubMed

    Hanson, Susan K; Baker, R Tom; Gordon, John C; Scott, Brian L; Silks, L A Pete; Thorn, David L

    2010-12-22

    Dipicolinate vanadium(V) alkoxide complexes (dipic)V(V)(O)(OR) (OR = isopropoxide (1), n-butanoxide (2), cyclobutanoxide (3), and α-tert-butylbenzylalkoxide (4)) react with pyridine to afford vanadium(IV) and 0.5 equiv of an aldehyde or ketone product. The role of pyridine in the reaction has been investigated. Both NMR and X-ray crystallography experiments indicate that pyridine coordinates to 1, which is in equilibrium with (dipic)V(V)(O)(O(i)Pr)(pyr) (1-Pyr). Kinetic studies of the alcohol oxidation suggest a pathway where the rate-limiting step is bimolecular and involves attack of pyridine on the C-H bond of the isopropoxide ligand of 1 or 1-Pyr. The oxidations of mechanistic probes cyclobutanol and α-tert-butylbenzylalcohol support a two-electron pathway proceeding through a vanadium(III) intermediate. The alcohol oxidation reaction is promoted by more basic pyridines and facilitated by electron-withdrawing substituents on the dipicolinate ligand. The involvement of base in the elementary alcohol oxidation step observed for the dipicolinate system is an unprecedented mechanism for vanadium-mediated alcohol oxidation and suggests new ways to tune reactivity and selectivity of vanadium catalysts. PMID:21121665

  4. 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...

  5. 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

  6. 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...

  7. NaHSO4-SiO2 as an efficient and chemoselective catalyst, for the synthesis of acylal from aldehydes under, solvent-free conditions

    PubMed Central

    2012-01-01

    Background Structurally diverse aldehydes are successfully converted into acylals (1,1-diacetates) with acetic anhydride using NaHSO4-SiO2 as a mild, convenient and inexpensive catalyst under solvent-free conditions. The noteworthy features of the present system are shorter reaction times, and mild and solvent-free conditions. Furthermore, it offers chemoselective protection of aldehydes. Results Both aromatic and aliphatic aldehydes reacts smoothly with acetic anhydride in presence of silica supported sodium hydrogen sulphate to afford the corresponding 1,1-diacetates in good to excellent yields. We studied competitive reactions for the acylation of aldehydes in the presence of ketones using silica supported sodium hydrogen sulphate as a catalyst. Using this catalytic system, the highly selective conversion of an aldehyde in the presence of ketone was observed. Conclusions NaHSO4-SiO2 is a chemoselective and highly efficient catalyst for acylal formation from aldehydes. The advantages of this methodology over the reported methods is the availability of the starting materials, simplicity of acylation procedure, a clean work-up, a short reaction time, high yields and reusability. PMID:23148682

  8. Mild electrophilic trifluoromethylthiolation of ketones with trifluoromethanesulfanamide.

    PubMed

    Wu, Wei; Zhang, Xuxue; Liang, Fang; Cao, Song

    2015-07-01

    A straightforward and convenient approach for trifluoromethylthiolation of various acyclic and cyclic ketones with PhNHSCF3 is described. The reaction proceeds smoothly in the presence of acetyl chloride at room temperature and affords α-trifluoromethylthiolated ketones in fair to good yields. PMID:26030292

  9. Fueling Performance: Ketones Enter the Mix.

    PubMed

    Egan, Brendan; D'Agostino, Dominic P

    2016-09-13

    Ketone body metabolites serve as alternative energy substrates during prolonged fasting, calorie restriction, or reduced carbohydrate (CHO) availability. Using a ketone ester supplement, Cox et al. (2016) demonstrate that acute nutritional ketosis alters substrate utilization patterns during exercise, reduces lactate production, and improves time-trial performance in elite cyclists. PMID:27626197

  10. Reaction of the oximes of aliphatic aldehydes and ketones with alkoxyethenes

    SciTech Connect

    Voronkov, M.G.; Keiko, N.A.; Shuvashev, Yu.A.; Kalikhman, I.D.; Keiko, V.V.

    1987-06-10

    In the reaction of acetone oxime with alkyl vinyl ethers in the presence of zinc chloride variable amounts of acetone 0,0'-(2-propylidene)dioxime, acetaldehyde dialkyl acetal, acetaldehyde 0-(1-alkoxyethyl)oxide, and acetone 0-(1-alkoxy-1-methylethyl)oxime, depending on the reaction conditions, are formed in addition to acetone 0-(1-alkoxyethyl)oxime (the initial addition product). In the reaction of acetaldehyde oxime with alkyl vinyl ethers in the presence of zinc chloride acetaldehyde oxime with alkyl vinyl ethers in the presence of zinc chloride acetaldehyde dialkyl acetal was isolated in addition to acetaldehyde 0-(1-alkoxyethyl)oxime. A mechanism for the formation of the obtained compounds is proposed.

  11. 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.

  12. 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

  13. Synthesis of tertiary arylamines: Lewis acid-catalyzed direct reductive N-alkylation of secondary amines with ketones through an alternative pathway.

    PubMed

    Nayal, Onkar S; Thakur, Maheshwar S; Bhatt, Vinod; Kumar, Manoranjan; Kumar, Neeraj; Singh, Bikram; Sharma, Upendra

    2016-08-11

    We report herein a highly efficient, tin(ii)/PMHS catalyzed reductive N-alkylation of arylamines with ketones affording tertiary arylamines. A very wide substrate scope was observed for the current catalytic method as all six permutations of ketones/aldehydes/heterocyclic carbonyls and primary/secondary/heterocyclic amines were well tolerated, enabling access to secondary, tertiary and heterocyclic amines. The method is also convenient for the synthesis of N-substituted isoindolinones and phthalazinones via a tandem amination-amidation sequence. Mechanistic investigations revealed a carbocationic pathway instead of an ordinary direct reductive amination pathway. PMID:27363507

  14. 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

  15. Asymmetric Catalysis with CO2 : The Direct α-Allylation of Ketones.

    PubMed

    Pupo, Gabriele; Properzi, Roberta; List, Benjamin

    2016-05-10

    Quaternary stereocenters are found in numerous bioactive molecules. The Tsuji-Trost reaction has proven to be a powerful C-C bond forming process, and, at least in principle, should be well suited to access quaternary stereocenters via the α-allylation of ketones. However, while indirect approaches are known, the direct, catalytic asymmetric α-allylation of branched ketones has been elusive until today. By combining "enol catalysis" with the use of CO2 as a formal catalyst for asymmetric catalysis, we have now developed a solution to this problem: we report a direct, highly enantioselective and highly atom-economic Tsuji-Trost allylation of branched ketones with allylic alcohol. Our reaction delivers products bearing quaternary stereocenters with high enantioselectivity and water as the sole by-product. We expect our methodology to be of utility in asymmetric catalysis and inspire the design of other highly atom-economic transformations. PMID:27071633

  16. Discovery of a novel class of covalent inhibitor for aldehyde dehydrogenases

    SciTech Connect

    Khanna, Mary; Chen, Che-Hong; Kimble-Hill, Ann; Parajuli, Bibek; Perez-Miller, Samantha; Baskaran, Sulochanadevi; Kim, Jeewon; Dria, Karl; Vasiliou, Vasilis; Mochly-Rosen, Daria; Hurley, Thomas D.

    2012-10-23

    Human aldehyde dehydrogenases (ALDHs) comprise a family of 17 homologous enzymes that metabolize different biogenic and exogenic aldehydes. To date, there are relatively few general ALDH inhibitors that can be used to probe the contribution of this class of enzymes to particular metabolic pathways. Here, we report the discovery of a general class of ALDH inhibitors with a common mechanism of action. The combined data from kinetic studies, mass spectrometric measurements, and crystallographic analyses demonstrate that these inhibitors undergo an enzyme-mediated {beta}-elimination reaction generating a vinyl ketone intermediate that covalently modifies the active site cysteine residue present in these enzymes. The studies described here can provide the basis for rational approach to design ALDH isoenzyme-specific inhibitors as research tools and perhaps as drugs, to address diseases such as cancer where increased ALDH activity is associated with a cellular phenotype.

  17. Characterization of exhaust emissions from alcohol-fueled vehicles. Final report

    SciTech Connect

    Smith, L.R.

    1985-05-01

    The report describes the laboratory effort to develop analytical techniques to characterize exhaust emissions from neat methanol and ethanol-fueled vehicles. Analytical techniques were developed or modified to allow the measurement of methanol, ethanol, aldehydes and ketones, methyl nitrite, and formic and acetic acid in both raw and CVS-diluted exhaust. The methods were validated, qualified, and then used to evaluate exhaust emissions from a 1981 Ford Escort chassis with a 1983 1.6-liter methanol-fueled Ford Escort engine. The vehicle was evaluated over the Light-Duty Federal Test Procedure (FTP) and at 30 and 55 mph steady-state operation both with and without a catalytic converter. In addition to testing conducted with the 90% methanol/10% gasoline fuel blend for which the Ford Escort engine was designed, testing was also conducted with 100% methanol fuel. Other areas investigated included unburned fuel hydrocarbon composition, FID response correction for alcohols as compared with propane, and losses of unburned fuel and aldehydes in the sampling system.

  18. Half sandwich complexes of chalcogenated pyridine based bi-(N, S/Se) and terdentate (N, S/Se, N) ligands with (η6-benzene)ruthenium(II): synthesis, structure and catalysis of transfer hydrogenation of ketones and oxidation of alcohols.

    PubMed

    Prakash, Om; Sharma, Kamal Nayan; Joshi, Hemant; Gupta, Pancham Lal; Singh, Ajai K

    2013-06-28

    The half sandwich complexes [(η(6)-C6H6)Ru(L)Cl][PF6] (1-5) have been synthesized by the reactions of (2-arylchalcogenomethyl)pyridine [L = L1-L3] and bis(2-pyridylmethyl)chalcogenide [L = L4-L5] (chalcogen = S, Se; Ar = Ph/2-pyridyl for S, Ph for Se) with [(η(6)-C6H6)RuCl2]2, at room temperature followed by treatment with NH4PF6. Their HR-MS, (1)H, (13)C{(1)H} and (77)Se{(1)H} NMR spectra have been found characteristic. The single crystal structures of 1-5 have been established by X-ray crystallography. The Ru has pseudo-octahedral half sandwich "piano-stool" geometry. The complexes 1-5 have been found efficient for catalytic oxidation of alcohols with N-methylmorpholine-N-oxide (NMO) and transfer hydrogenation of ketones with 2-propanol (at moderate temperature 80 °C) as TON values are up to 9.9 × 10(3) and 9.8 × 10(3) respectively for the two catalytic reactions. On comparing the required catalyst loading for good conversions and reaction time for the present complexes with those reported in literature for other transfer hydrogenation/oxidation catalysts, it becomes apparent that 1-5 have good promise. The complexes of Se ligands have been found more efficient than their sulphur analogues. The complexes of bidentate ligands are more efficient than those of terdentate, due to difficult bond cleavage in the case of latter. These orders of efficiency are supported by DFT calculations. The calculated bond lengths/angles by DFT are generally consistent with the experimental ones. PMID:23632941

  19. Tropospheric light alcohols, carbonyls, and acetonitrile: Concentrations in the southwestern United States and Henry's Law data

    NASA Astrophysics Data System (ADS)

    Snider, Jefferson R.; Dawson, G. A.

    1985-04-01

    Aliphatic alcohols (C1 - C4), aldehydes (C1 - C2) and ketones (C3 - C4) have been determined at Tucson, Arizona, and at two rural sites about 40 km distant. Acetonitrile was also measured at the rural sites. The method involved condensation sampling, condensate preconcentration, and gas chromatography. Henry's law coefficients were required for all components and were determined. Mean concentrations in Tucson were higher than those in the rural areas by factors typically between 2 and 8; urban formaldehyde was only slightly elevated. Mean alcohol concentrations ranged from 7.9 ppb (C1) to 0.12 ppb (C4) within the city and from 2.6 ppb (C1) to 0.06 ppb (C4) at the rural sites. Acetone was found at 12 ppb in the city and 2.8 ppb at the rural sites. Concentrations of butanone were a factor of 5 lower. Acetaldehyde, at 23 ppb (city) and 6.9 ppb (rural), far exceeded formaldehyde concentrations (1.8 ppb in the city, and 1.5 ppb at the rural sites). Acetonitrile was found at the rural sites at a mean concentration of 60 ppt. A dimensionless Henry's law coefficient (mol L-1 of liquid/mol L-1 of vapor) was suprisingly similar for the alcohols at 0°C, ranging between 2×104 and 3.4×104 (900-1500 mol L-1 atm-1) the ketones were a factor of 10 lower. For acetaldehyde the coefficient was 1.7×103 (76 mol L-1 atm-1) and for acetonitrile 3.7×103 (165 mol L-1 atm-1). Concentrations of oxygenated organics in the condensates and in precipitation were compared; it was tentatively concluded that concentration differences of the carbonyls were consistent with these species being produced within the cloud, for example, by aqueous photochemistry.

  20. Efficient Visible Light-Driven Splitting of Alcohols into Hydrogen and Corresponding Carbonyl Compounds over a Ni-Modified CdS Photocatalyst.

    PubMed

    Chai, Zhigang; Zeng, Ting-Ting; Li, Qi; Lu, Liang-Qiu; Xiao, Wen-Jing; Xu, Dongsheng

    2016-08-17

    Splitting of alcohols into hydrogen and corresponding carbonyl compounds has potential applications in hydrogen production and chemical industry. Herein, we report that a heterogeneous photocatalyst (Ni-modified CdS nanoparticles) could efficiently split alcohols into hydrogen and corresponding aldehydes or ketones in a stoichiometric manner under visible light irradiation. Optimized apparent quantum yields of 38%, 46%, and 48% were obtained at 447 nm for dehydrogenation of methanol, ethanol, and 2-propanol, respectively. In the case of dehydrogenation of 2-propanol, a turnover number of greater than 44 000 was achieved. To our knowledge, these are unprecedented values for photocatalytic splitting of liquid alcohols under visible light to date. Besides, the current catalyst system functions well with other aliphatic and aromatic alcohols, affording the corresponding carbonyl compounds with good to excellent conversion and outstanding selectivity. Moreover, mechanistic investigations suggest that an interface between Ni nanocrystal and CdS plays a key role in the reaction mechanism of the photocatalytic splitting of alcohol. PMID:27477237

  1. The Potential of Photochemical Transition Metal Reactions in Prebiotic Organic Synthesis. I. Observed Conversion of Methanol into Ethylene Glycol as Possible Prototype for Sugar Alcohol Formation

    NASA Astrophysics Data System (ADS)

    Eisch, John J.; Munson, Peter R.; Gitua, John N.

    2004-10-01

    Photochemical processes involving redox reactions between metal ions and organic substrates possess the versatile potential for having harnessed solar energy for prebiotic organic synthesis. The present study in our Laboratory has shown that ultraviolet irradiation of transition metal ions such as of Ni, Co, Fe, Cu and Ti dissolved in primary or secondary alcohols causes photoreduction of the metal ions with the concomitant oxidation of the alcohol to aldehyde or ketone. An observed accompaniment of this novel `light' reaction has been the known `dark' pinacol reaction, whereby the carbonyl derivative underwent bimolecular coupling to the diol by the photogenerated reduced transition metal reagent. These tandem `light-dark' processes possess the potential for the stepwise synthesis of dimeric 1,2-diols from simpler alcohols under conditions that might have prevailed on the prebiotic earth. Experiments reported here have demonstrated that such a tandem `light-dark' conversion of methanol into ethylene glycol, via formaldehyde, does in fact occur, when nickel(II) acetylacetonate solutions in methanol undergo prolonged irradiation at 185-254 nm. Since ethylene glycol can be considered as the simplest sugar alcohol, these findings may provide novel insight into the prebiotic oligomerization of formaldehyde into higher sugar alcohols or even sugars.

  2. 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

  3. 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

  4. [Classification of alcohol metabolizing enzymes and polymorphisms--specificity in Japanese].

    PubMed

    Harada, S

    2001-04-01

    Multiple forms and gene loci of human alcohol dehydrogenase (ADH EC: 1.2.1.3) and aldehyde dehydrogenase (ALDH, EC: 1.2.1.3) in the major pathway of alcohol metabolism have been found and characterized in the last two decades. With the coenzyme NAD, these enzymes catalyze the reversible conversion of organic alcohols to ketones or aldehydes, and aldehyde to acetic acid. The ADH genes are mapped to chromosome 4p21-25, but the ALDH genes are localized at different chromosomes. The cytochrome P450 2E1 (CYP2E1) gene, which is mapped to chromosome 10q24.3-qter contributes also the conversion of ethanol to acetaldehyde. Genetic polymorphisms have been reported in these alcohol metabolizing enzymes. The metabolisms of alcohol and acetaldehyde in liver and blood after drinking alcohol are thought to be influenced by the interactive action of these enzymes. Amongst the five major classes of the ADH subunits (alpha, beta, gamma, pi, chi, sigma), beta and gamma subunits show genetic polymorphisms. Recently a new nomenclature for ALDH genes has been recommend based on divergent evolution and chromosomal mapping. Two major isoforms designated as cytosolic ALDH1 and mitochondrial ALDH2 can be distinguished by their electrophoretic and kinetic properties as well as by their subcellular localization. Mitochondrial ALDH2 is a major enzyme in the oxidation of acetaldehyde derived from ethanol metabolism. The catalytic deficiency of ALDH2 isozyme is responsible for flushing and other vasomotor symptoms caused by higher acetaldehyde levels after alcohol intake. So far, frequencies of the two alleles of ALDH2 in Mongoloid have been reported in the different population groups. The catalytic deficiency of ALDH2 is caused by a structural point mutation at amino acid position 487, where a substitution of Glu to Lys resulting from a transition of G (C) to A (T) at 1510 nucleotide from the initiation codon has occurred. Individuals deficient in ALDH2 activity refrain from excessive drinking

  5. Catalytic Oxidation of Alcohol via Nickel Phosphine Complexes with Pendant Amines

    SciTech Connect

    Weiss, Charles J.; Das, Partha Pratim; Higgins, Deanna LM; Helm, Monte L.; Appel, Aaron M.

    2014-09-05

    Nickel complexes were prepared with diphosphine ligands that contain pendant amines, and these complexes catalytically oxidize primary and secondary alcohols to their respective aldehydes and ketones. Kinetic and mechanistic studies of these prospective electrocatalysts were performed to understand what influences the catalytic activity. For the oxidation of diphenylmethanol, the catalytic rates were determined to be dependent on the concentration of both the catalyst and the alcohol. The catalytic rates were found to be independent of the concentration of base and oxidant. The incorporation of pendant amines to the phosphine ligand results in substantial increases in the rate of alcohol oxidation with more electron-donating substituents on the pendant amine exhibiting the fastest rates. We thank Dr. John C. Linehan, Dr. Elliott B. Hulley, Dr. Jonathan M. Darmon, and Dr. Elizabeth L. Tyson for helpful discussions. Research by CJW, PD, DLM, and AMA was supported by the US Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences & Biosciences. Research by MLH was supported as part of the Center for Molecular Electrocatalysis, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences. Pacific Northwest National Laboratory (PNNL) is a multiprogram national laboratory operated for DOE by Battelle.

  6. General and Mild Cobalt-Catalyzed C-Alkylation of Unactivated Amides and Esters with Alcohols.

    PubMed

    Deibl, Nicklas; Kempe, Rhett

    2016-08-31

    The borrowing hydrogen or hydrogen autotransfer methodology is an elegant and sustainable or green concept to construct carbon-carbon bonds. In this concept, alcohols, which can be obtained from barely used and indigestible biomass, such as lignocellulose, are employed as alkylating reagents. An especially challenging alkylation is that of unactivated esters and amides. Only noble metal catalysts based on iridium and ruthenium have been used to accomplish these reactions. Herein, we report on the first base metal-catalyzed α-alkylation of unactivated amides and esters by alcohols. Cobalt complexes stabilized with pincer ligands, recently developed in our laboratory, catalyze these reactions very efficiently. The precatalysts can be synthesized easily from commercially available starting materials on a multigram scale and are self-activating under the basic reaction conditions. This Co catalyst class is also able to mediate alkylation reactions of both esters and amides. In addition, we apply the methodology to synthesize ketones and to convert alcohols into aldehydes elongated by two carbon atoms. PMID:27490682

  7. γ-Unsaturated aldehydes as potential Lilial replacers.

    PubMed

    Schroeder, Martin; Mathys, Marion; Ehrensperger, Nadja; Büchel, Michelle

    2014-10-01

    A series of Claisen rearrangements was undertaken in order to find a replacement for Lilial (=3-(4-(tert-butyl)phenyl)-2-methylpropanal), a high-tonnage perfumery ingredient with a lily-of-the-valley odour, which is a CMR2 material [1]. 5,7,7-Trimethyl-4-methyleneoctanal (10), the synthesis of which is described, became the main lead. It possesses an odour which is very close to that of Lilial but lacks its substantivity. Aldehydes with higher molecular weights than that of 10 were, therefore, synthesised in order to boost substantivity and to understand the structural requirements for a 'Lilial' odour. The aldehydes were obtained via Claisen rearrangements of 'exo-methylidene' vinyl ethers, allenyl vinyl ethers, or allenyl allyl ethers. Alternatively, coupling of terminal alkynes with allyl alcohols led to the desired aldehydes. Derivatives of 10 and their sila analogues were also synthesised. The olfactory properties of all synthesised molecules were evaluated for possible structure-odour relationships (SOR). PMID:25329790

  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. 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.

  10. 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.

  11. 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.

  12. Role of pseudoephedrine as chiral auxiliary in the "acetate-type" aldol reaction with chiral aldehydes; asymmetric synthesis of highly functionalized chiral building blocks.

    PubMed

    Ocejo, Marta; Carrillo, Luisa; Vicario, Jose L; Badía, Dolores; Reyes, Efraim

    2011-01-21

    We have studied in depth the aldol reaction between acetamide enolates and chiral α-heterosubstituted aldehydes using pseudoephedrine as chiral auxiliary under double stereodifferentiation conditions, showing that high diastereoselectivities can only be achieved under the matched combination of reagents and provided that the α-heteroatom-containing substituent of the chiral aldehyde is conveniently protected. Moreover, the obtained highly functionalized aldols have been employed as very useful starting materials for the stereocontrolled preparation of other interesting compounds and chiral building blocks such as pyrrolidines, indolizidines, and densely functionalized β-hydroxy and β-amino ketones using simple and high-yielding methodologies. PMID:21188970

  13. 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...

  14. Synthesis of o-(Dimethylamino)aryl Ketones, Acridones, Acridinium Salts, and 1H-Indazoles by the Reaction of Hydrazones and Arynes

    PubMed Central

    Dubrovskiy, Anton V.; Larock, Richard C.

    2012-01-01

    A novel, efficient route to biologically and pharmaceutically important o-(dimethylamino)aryl ketones, acridones, acridinium salts, and 1H-indazoles has been developed starting from readily available hydrazones of aldehydes and o-(trimethylsilyl)aryl triflates. The reaction proceeds through arynes under mild conditions, tolerates a wide range of functional groups, and provides the final products in good to excellent yields. PMID:23206164

  15. Nickel-catalyzed transfer hydrogenation of ketones using ethanol as a solvent and a hydrogen donor.

    PubMed

    Castellanos-Blanco, Nahury; Arévalo, Alma; García, Juventino J

    2016-09-14

    We report a nickel(0)-catalyzed direct transfer hydrogenation (TH) of a variety of alkyl-aryl, diaryl, and aliphatic ketones with ethanol. This protocol implies a reaction in which a primary alcohol serves as a hydrogen atom source and solvent in a one-pot reaction without any added base. The catalytic activity of the nickel complex [(dcype)Ni(COD)] (e) (dcype: 1,2-bis(dicyclohexyl-phosphine)ethane, COD: 1,5-cyclooctadiene), towards transfer hydrogenation (TH) of carbonyl compounds using ethanol as the hydrogen donor was assessed using a broad scope of ketones, giving excellent results (up to 99% yield) compared to other homogeneous phosphine-nickel catalysts. Control experiments and a mercury poisoning experiment support a homogeneous catalytic system; the yield of the secondary alcohols formed in the TH reaction was monitored by gas chromatography (GC) and NMR spectroscopy. PMID:27511528

  16. Iron-, Cobalt-, and Nickel-Catalyzed Asymmetric Transfer Hydrogenation and Asymmetric Hydrogenation of Ketones.

    PubMed

    Li, Yan-Yun; Yu, Shen-Luan; Shen, Wei-Yi; Gao, Jing-Xing

    2015-09-15

    Chiral alcohols are important building blocks in the pharmaceutical and fine chemical industries. The enantioselective reduction of prochiral ketones catalyzed by transition metal complexes, especially asymmetric transfer hydrogenation (ATH) and asymmetric hydrogenation (AH), is one of the most efficient and practical methods for producing chiral alcohols. In both academic laboratories and industrial operations, catalysts based on noble metals such as ruthenium, rhodium, and iridium dominated the asymmetric reduction of ketones. However, the limited availability, high price, and toxicity of these critical metals demand their replacement with abundant, nonprecious, and biocommon metals. In this respect, the reactions catalyzed by first-row transition metals, which are more abundant and benign, have attracted more and more attention. As one of the most abundant metals on earth, iron is inexpensive, environmentally benign, and of low toxicity, and as such it is a fascinating alternative to the precious metals for catalysis and sustainable chemical manufacturing. However, iron catalysts have been undeveloped compared to other transition metals. Compared with the examples of iron-catalyzed asymmetric reduction, cobalt- and nickel-catalyzed ATH and AH of ketones are even seldom reported. In early 2004, we reported the first ATH of ketones with catalysts generated in situ from iron cluster complex and chiral PNNP ligand. Since then, we have devoted ourselves to the development of ATH and AH of ketones with iron, cobalt, and nickel catalysts containing novel chiral aminophosphine ligands. In our study, the iron catalyst containing chiral aminophosphine ligands, which are expected to control the stereochemistry at the metal atom, restrict the number of possible diastereoisomers, and effectively transfer chiral information, are successful catalysts for enantioselective reduction of ketones. Among these novel chiral aminophosphine ligands, 22-membered macrocycle P2N4

  17. An animal model of human aldehyde dehydrogenase deficiency

    SciTech Connect

    Chang, C.; Mann, J.; Yoshida, A.

    1994-09-01

    The genetic deficiency of ALDH2, a major mitochondrial aldehyde dehydrogenase, is intimately related to alcohol sensitivity and the degree of predisposition to alcoholic diseases in humans. The ultimate biological role of ALDH2 can be exposed by knocking out the ALDH2 gene in an animal model. As the first step for this line of studies, we cloned and characterized the ALDH2 gene from mouse C57/6J strain which is associated with a high alcohol preference. The gene spans 26 kbp and is composed of 13 exons. Embryonic stem cells were transfected with a replacement vector which contains a partially deleted exon3, a positive selection cassette (pPgk Neo), exon 4 with an artificial stop codon, exons 5, 6, 7, and a negative selection cassette (pMCI-Tk). Genomic DNAs prepared from drug resistant clones were analyzed by polymerase chain reaction and by Southern blot analysis to distinguish random integration from homologous recombination. Out of 132 clones examined, 8 had undergone homologous recombination at one of the ALDH2 alleles. The cloned transformed embryonic stem cells with a disrupted ALDH2 allele were injected into blastocysts. Transplantation of the blastocysts into surrogate mother mice yielded chimeric mice. The role of ALDH2 in alcohol preference, alcohol sensitivity and other biological and behavioral characteristics can be elucidated by examining the heterozygous and homozygous mutant strains produced by breeding of chimeric mice.

  18. The use of tomato aminoaldehyde dehydrogenase 1 for the detection of aldehydes in fruit distillates.

    PubMed

    Frömmel, Jan; Tarkowski, Petr; Kopečný, David; Šebela, Marek

    2016-09-25

    Plant NAD(+)-dependent aminoaldehyde dehydrogenases (AMADHs, EC 1.2.1.19) belong to the family 10 of aldehyde dehydrogenases. They participate in the metabolism of polyamines or osmoprotectants. The enzymes are characterized by their broad substrate specificity covering ω-aminoaldehydes, aliphatic and aromatic aldehydes as well as nitrogen-containing heterocyclic aldehydes. The isoenzyme 1 from tomato (Solanum lycopersicum; SlAMADH1) oxidizes aliphatic aldehydes very efficiently and converts also furfural, its derivatives or benzaldehyde, which are present at low concentrations in alcoholic distillates such as fruit brandy. In this work, SlAMADH1 was examined as a bioanalytical tool for their detection. These aldehydes arise from fermentation processes or thermal degradation of sugars and their presence is related to health complications after consumption including nausea, emesis, sweating, decrease in blood pressure, hangover headache, among others. Sixteen samples of slivovitz (plum brandy) from local producers in Moravia, Czech Republic, were analyzed for their aldehyde content using a spectrophotometric activity assay with SlAMADH1. In all cases, there were oxidative responses observed when monitoring NADH production in the enzymatic reaction. Aldehydes in the distillate samples were also subjected to a standard determination using reversed-phase HPLC with spectrophotometric and tandem mass spectrometric detection after a derivatization with 2,4-dinitrophenylhydrazine. Results obtained by both methods were found to correlate well for a majority of the analyzed samples. The possible applicability of SlAMADH1 for the evaluation of aldehyde content in food and beverages has now been demonstrated. PMID:26703808

  19. 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.

  20. 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 ...

  1. 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

  2. [Death by alcoholic ketoacidosis--analytical procedure and case report].

    PubMed

    Wöllner, Kirsten; Heß, Cornelius; Madea, Burkhard

    2015-01-01

    Alcoholic ketoacidosis is a medical emergency, which is characterized at first by an elevated level of ketone bodies. The production of these ketone bodies is accompanied by an equimolar quantity of hydrogen ions and thus causes acidosis, which cannot be detected post-mortem due to anaerobic glycolysis, whereas the three ketone bodies beta-hydroxybutyrate, acetoacetate and acetone can be easily identified. However, the limits of ketone body concentrations mentioned in the literature for diagnosing ketoacidosis vary significantly, partly due to inhomogeneous study groups. A 44-year-old woman was found dead with numerous haematomas and partial mummification. Some days before, she had reported her partner to the police for rape. Consequently investigations for homicide were initiated. The autopsy itself did not reveal any morphologically identifiable cause of death. The ketone body concentrations in three matrices (vitreous humour, cerebrospinal fluid, cardiac blood) left no doubt that death was due to alcoholic ketoacidosis. PMID:26548035

  3. Microbial production of natural raspberry ketone.

    PubMed

    Beekwilder, Jules; van der Meer, Ingrid M; Sibbesen, Ole; Broekgaarden, Mans; Qvist, Ingmar; Mikkelsen, Joern D; Hall, Robert D

    2007-10-01

    Raspberry ketone is an important compound for the flavour industry. It is frequently used in products such as soft drinks, sweets, puddings and ice creams. The compound can be produced by organic synthesis. Demand for "natural" raspberry ketone is growing considerably. However, this product is extremely expensive. Consequently, there is a remaining desire to better understand how raspberry ketone is synthesized in vivo, and which genes and enzymes are involved. With this information we will then be in a better position to design alternative production strategies such as microbial fermentation. This article focuses on the identification and application of genes potentially linked to raspberry ketone synthesis. We have isolated candidate genes from both raspberry and other plants, and these have been introduced into bacterial and yeast expression systems. Conditions have been determined that result in significant levels of raspberry ketone, up to 5 mg/L. These results therefore lay a strong foundation for a potentially renewable source of "natural" flavour compounds making use of plant genes. PMID:17722151

  4. Copper-Mediated Cross-Dehydrogenative Coupling of 2-Methylpyridine and 8-Methylquinoline with Methyl Ketones and Benzamides.

    PubMed

    Kumar, Gadde Sathish; Boyle, Joshua William; Tejo, Ciputra; Chan, Philip Wai Hong

    2016-02-01

    A synthetic method to prepare (E)-(pyridin-2-yl)enones and (E)-(quinolin-8-yl)enones that relies on the respective copper(I)-catalyzed formal cross-dehydrogenative coupling (CDC) reaction of 2-methylpyridine and 8-methylquinoline with methyl ketones has been discovered. The mechanism was delineated to follow a pathway involving oxidation of the N-heterocycle to its corresponding aldehyde adduct prior to reaction with the methyl ketone. The versatility and substrate dependent divergence in the reactivity of the copper-mediated CDC strategy was exemplified by its application to the synthesis of N-(quinolin-8-ylmethyl)amide and N-(quinolin-8-ylmethyl)aniline adducts on switching the cross-coupling partner to benzamides or an aniline derivative. PMID:26586026

  5. π-Expanded α,β-unsaturated ketones: synthesis, optical properties, and two-photon-induced polymerization.

    PubMed

    Nazir, Rashid; Bourquard, Florent; Balčiūnas, Evaldas; Smoleń, Sabina; Gray, David; Tkachenko, Nikolai V; Farsari, Maria; Gryko, Daniel T

    2015-02-23

    A library of π-expanded α,β-unsaturated ketones was designed and synthesized. They were prepared by a combination of Wittig reaction, Sonogashira reaction, and aldol condensation. It was further demonstrated that the double aldol condensation can be performed effectively for highly polarized styrene- and diphenylacetylene-derived aldehydes. The strategic placement of two dialkylamino groups at the periphery of D-π-A-π-D molecules resulted in dyes with excellent solubility. These ketones absorb light in the region 400-550 nm. Many of them display strong solvatochromism so that the emission ranges from 530-580 nm in toluene to the near-IR region in benzonitrile. Ketones based on cyclobutanone as central moieties display very high fluorescence quantum yields in nonpolar solvents, which decrease drastically in polar media. Photophysical studies of these new functional dyes revealed that they possess an enhanced two-photon absorption cross section when compared with simpler ketone derivatives. Due to strong polarization of the resulting dyes, values of two-photon absorption cross sections on the level of 200-300 GM at 800 nm were achieved, and thanks to that as well as the presence of the keto group, these new two-photon initiators display excellent performance so that the operating region is 5-75 mW in some cases. PMID:25504985

  6. The Nitric Acid Oxidation of Selected Alcohols and Ketones.

    ERIC Educational Resources Information Center

    Field, Kurt W.; And Others

    1985-01-01

    Shows that nitric acid can be used as a rapid, versatile, and economical oxidant for selected organic substances. The experiments (with background information, procedures, and results provided) require one three-hour laboratory period but could serve as open-ended projects since substrates not described could be oxidized. (JN)

  7. Ketone ester effects on metabolism and transcription

    PubMed Central

    Veech, Richard L.

    2014-01-01

    Ketosis induced by starvation or feeding a ketogenic diet has widespread and often contradictory effects due to the simultaneous elevation of both ketone bodies and free fatty acids. The elevation of ketone bodies increases the energy of ATP hydrolysis by reducing the mitochondrial NAD couple and oxidizing the coenzyme Q couple, thus increasing the redox span between site I and site II. In contrast, metabolism of fatty acids leads to a reduction of both mitochondrial NAD and mitochondrial coenzyme Q causing a decrease in the ΔG of ATP hydrolysis. In contrast, feeding ketone body esters leads to pure ketosis, unaccompanied by elevation of free fatty acids, producing a physiological state not previously seen in nature. The effects of pure ketosis on transcription and upon certain neurodegenerative diseases make approach not only interesting, but of potential therapeutic value. PMID:24714648

  8. Vapour-phase gold-surface-mediated coupling of aldehydes with methanol

    NASA Astrophysics Data System (ADS)

    Xu, Bingjun; Liu, Xiaoying; Haubrich, Jan; Friend, Cynthia M.

    2010-01-01

    Selective coupling of oxygenates is critical to many synthetic processes, including those necessary for the development of alternative fuels. We report a general process for selective coupling of aldehydes and methanol as a route to ester synthesis. All steps are mediated by oxygen-covered metallic gold nanoparticles on Au(111). Remarkably, cross-coupling of methanol with formaldehyde, acetaldehyde, benzaldehyde and benzeneacetaldehyde to methyl esters is promoted by oxygen-covered Au(111) below room temperature with high selectivity. The high selectivity is attributed to the ease of nucleophilic attack of the aldehydes by the methoxy intermediate-formed from methanol on the surface-which yields the methyl esters. The competing combustion occurs via attack of both methanol and the aldehydes by oxygen. The mechanistic model constructed in this study provides insight into factors that control selectivity and clearly elucidates the crucial role of Au nanoparticles as active species in the catalytic oxidation of alcohols, even in solution.

  9. 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

  10. Stereoselective Formation of Fully Substituted Ketone Enolates.

    PubMed

    Haimov, Elvira; Nairoukh, Zackaria; Shterenberg, Alexander; Berkovitz, Tiran; Jamison, Timothy F; Marek, Ilan

    2016-04-25

    The application of stereochemically defined acyclic fully substituted enolates of ketones to the enantioselective synthesis of quaternary carbon stereocenters would be highly valuable. Herein, we describe an approach leading to the formation of several new stereogenic centers through a combined metalation-addition of a carbonyl-carbamoyl transfer to reveal in situ stereodefined α,α-disubstituted enolates of ketone as a single stereoisomer. This approach could produce a series of aldol and Mannich products from enol carbamate with excellent diastereomeric ratios. PMID:27027778

  11. Regioselective hydroformylation of allylic alcohols.

    PubMed

    Lightburn, Thomas E; De Paolis, Omar A; Cheng, Ka H; Tan, Kian L

    2011-05-20

    A highly regioselective hydroformylation of allylic alcohols is reported toward the synthesis of β-hydroxy-acid and aldehyde products. The selectivity is achieved through the use of a ligand that reversibly binds to alcohols in situ, allowing for a directed hydroformylation to occur. The application to trisubstituted olefins was also demonstrated, which yields a single diastereomer product consistent with a stereospecific addition of CO and hydrogen. PMID:21504208

  12. Regioselective Hydroformylation of Allylic Alcohols

    PubMed Central

    Lightburn, Thomas E.; De Paolis, Omar A.; Cheng, Ka H.; Tan, Kian L.

    2011-01-01

    A highly regioselective hydroformylation of allylic alcohols is reported towards the synthesis of β-hydroxy-acid and aldehyde products. The selectivity is achieved through the use of a ligand that reversibly binds to alcohols in situ, allowing for a directed hydroformylation to occur. The application to trisubstituted olefins was also demonstrated, which yields a single diastereomer product consistent with a stereospecific addition of CO and hydrogen. PMID:21504208

  13. The oxidation of chiral alcohols catalyzed by catalase in organic solvents

    SciTech Connect

    Magner, E.; Klibanov, A.M.

    1995-04-20

    The catalytic properties of bovine liver catalase have been investigated in organic solvents. In tetrahydrofuran, dioxane, and acetone (all containing 1% to 3% of water), the enzyme breaks down tert-butyl hydroperoxide several fold faster than in pure water. Furthermore, the rate of catalase-catalyzed production of tert-butanol from tert-butyl hydroperoxide increases more than 400-fold upon transition from aqueous buffer to ethanol as the reaction medium. The mechanistic rationale for this striking effect is that in aqueous buffer the rate-limiting step of the enzymatic process involves the reduction of catalase`s compound 1 by tert-butyl hydroperoxide. In ethanol, an additional step in the reaction scheme becomes available in which ethanol, greatly outcompeting the hydroperoxide, is oxidized by compound 1 regenerating the free enzyme. In solvents, such as acetonitrile or tetrahydrofuran, which themselves are not oxidizable by compound 1, catalase catalyzes the oxidation of numerous primary and secondary alcohols with tert-butyl hydroperoxide to the corresponding aldehydes or ketones. The enzymatic oxidation of some chiral alcohols (2,3-butanediol, citronellol, and menthol) under these conditions occurs enantioselectively. Examination of the enantioselectivity for the oxidation of 2,3-butanediol in a series of organic solvents reveals a considerable solvent dependence.

  14. The central role of ketones in reversible and irreversible hydrothermal organic functional group transformations

    NASA Astrophysics Data System (ADS)

    Yang, Ziming; Gould, Ian R.; Williams, Lynda B.; Hartnett, Hilairy E.; Shock, Everett L.

    2012-12-01

    Studies of hydrothermal reactions involving organic compounds suggest complex, possibly reversible, reaction pathways that link functional groups from reduced alkanes all the way to oxidized carboxylic acids. Ketones represent a critical functional group because they occupy a central position in the reaction pathway, at the point where Csbnd C bond cleavage is required for the formation of the more oxidized carboxylic acids. The mechanisms for the critical bond cleavage reactions in ketones, and how they compete with other reactions are the focus of this experimental study. We studied a model ketone, dibenzylketone (DBK), in H2O at 300 °C and 70 MPa for up to 528 h. Product analysis was performed as a function of time at low DBK conversions to reveal the primary reaction pathways. Reversible interconversion between ketone, alcohol, alkene and alkane functional groups is observed in addition to formation of radical coupling products derived from irreversible Csbnd C and Csbnd H homolytic bond cleavage. The product distributions are time-dependent but the bond cleavage products dominate. The major products that accumulate at longer reaction times are toluene and larger, dehydrogenated structures that are initially formed by radical coupling. The hydrogen atoms generated by dehydrogenation of the coupling products are predominantly consumed in the formation of toluene. Even though bond cleavage products dominate, no carboxylic acids were observed on the timescale of the reactions under the chosen experimental conditions.

  15. The Conversion of Carboxylic Acids to Ketones: A Repeated Discovery

    ERIC Educational Resources Information Center

    Nicholson, John W.; Wilson, Alan D.

    2004-01-01

    The conversion of carboxylic acids to ketones is a useful chemical transformation with a long history. Several chemists have claimed that they discovered the conversion of carboxylic acids to ketones yet in fact the reaction is actually known for centuries.

  16. Joining Astrobiology to Medicine, Resurrecting Ancient Alcohol Metabolism

    NASA Astrophysics Data System (ADS)

    Carrigan, M. A.; Uryasev, O.; Davis, R. W.; Chamberlin, S. G.; Benner, S. A.

    2010-04-01

    We apply an astrobiological approach to understand how primates responded to the emergence of ethanol in their environment by resurrecting two enzymes involved in the degradation of ethanol, alcohol dehydrogenase and aldehyde dehydrgenase.

  17. 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

  18. 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

  19. Nickel catalyzed α-arylation of ketones with aryltrimethylammonium triflates.

    PubMed

    Li, Jing; Wang, Zhong-Xia

    2016-08-21

    Nickel-catalyzed α-arylation of ketones involving aromatic C-N cleavage has been accomplished. Intermolecular coupling of aromatic ketones with a variety of aryltrimethylammonium triflates was achieved in the presence of Ni(COD)2, IPr·HCl, and LiOBu(t), giving α-arylated ketones in reasonable to excellent yields. PMID:27443786

  20. Vapor pressures and gas-film coefficients for ketones

    USGS Publications Warehouse

    Rathbun, R.E.; Tai, D.Y.

    1987-01-01

    Comparison of handbook vapor pressures for seven ketones with more recent literature data showed large differences for four of the ketones. Gas-film coefficients for the volatilization of these ketones from water determined by two different methods were in reasonable agreement. ?? 1987.

  1. 40 CFR 721.4925 - Methyl n-butyl ketone.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Methyl n-butyl ketone. 721.4925... Substances § 721.4925 Methyl n-butyl ketone. (a) Chemical substance and significant new use subject to reporting. (1) The chemical substance methyl n-butyl ketone, CAS Number 591-78-6, is subject to...

  2. 40 CFR 721.4925 - Methyl n-butyl ketone.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Methyl n-butyl ketone. 721.4925... Substances § 721.4925 Methyl n-butyl ketone. (a) Chemical substance and significant new use subject to reporting. (1) The chemical substance methyl n-butyl ketone, CAS Number 591-78-6, is subject to...

  3. 40 CFR 721.4925 - Methyl n-butyl ketone.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Methyl n-butyl ketone. 721.4925... Substances § 721.4925 Methyl n-butyl ketone. (a) Chemical substance and significant new use subject to reporting. (1) The chemical substance methyl n-butyl ketone, CAS Number 591-78-6, is subject to...

  4. 40 CFR 721.4925 - Methyl n-butyl ketone.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Methyl n-butyl ketone. 721.4925... Substances § 721.4925 Methyl n-butyl ketone. (a) Chemical substance and significant new use subject to reporting. (1) The chemical substance methyl n-butyl ketone, CAS Number 591-78-6, is subject to...

  5. Relaxation behavior in model compounds of poly(aryl-ether-ketone-ketone) as revealed by dielectric spectroscopy

    NASA Astrophysics Data System (ADS)

    Ezquerra, T. A.; Zolotukhin, M.; Privalko, V. P.; Baltá-Calleja, F. J.; Nequlqueo, G.; García, C.; de la Campa, J. G.; de Abajo, J.

    1999-05-01

    The relaxation behavior of a series of ether-ketone oligomers, considered as model compounds of poly(ether-ketone-ketone), was studied by means of dielectric spectroscopy. The dynamics of the α relaxation of ether-ketone model compounds as compared with that of poly(arylether-ketone-ketone) (PEKK) (50/50), shows up differences which can be attributed to the variation of inter- and intramolecular correlations with the chain length. Model compounds exhibit a nearly similar degree of cooperativity regardless the differences in Tg values. The PEKK (50/50) polymer exhibits stronger cooperativity than the oligomers suggesting that in poly(ether-ketone-ketone)s molecular motions above Tg extend to more than one monomeric unit.

  6. Alcoholism and Alcohol Abuse

    MedlinePlus

    ... This means that their drinking causes distress and harm. It includes alcoholism and alcohol abuse. Alcoholism, or ... brain, and other organs. Drinking during pregnancy can harm your baby. Alcohol also increases the risk of ...

  7. Steric vs. electronic effects in the Lactobacillus brevis ADH-catalyzed bioreduction of ketones.

    PubMed

    Rodríguez, Cristina; Borzęcka, Wioleta; Sattler, Johann H; Kroutil, Wolfgang; Lavandera, Iván; Gotor, Vicente

    2014-01-28

    Lactobacillus brevis ADH (LBADH) is an alcohol dehydrogenase that is commonly employed to reduce alkyl or aryl ketones usually bearing a methyl, an ethyl or a chloromethyl as a small ketone substituent to the corresponding (R)-alcohols. Herein we have tested a series of 24 acetophenone derivatives differing in their size and electronic properties for their reduction employing LBADH. After plotting the relative activity against the measured substrate volumes we observed that apart from the substrate size other effects must be responsible for the activity obtained. Compared to acetophenone (100% relative activity), other small substrates such as propiophenone, α,α,α-trifluoroacetophenone, α-hydroxyacetophenone, and benzoylacetonitrile had relative activities lower than 30%, while medium-sized ketones such as α-bromo-, α,α-dichloro-, and α,α-dibromoacetophenone presented relative activities between 70% and 550%. Moreover, the comparison between the enzymatic activity and the obtained final conversions using an excess or just 2.5 equiv. of the hydrogen donor 2-propanol, denoted again deviations between them. These data supported that these hydrogen transfer (HT) transformations are mainly thermodynamically controlled. For instance, bulky α-halogenated derivatives could be quantitatively reduced by LBADH even employing 2.5 equiv. of 2-propanol independently of their kinetic values. Finally, we found good correlations between the IR absorption band of the carbonyl groups and the degrees of conversion obtained in these HT processes, making this simple method a convenient tool to predict the success of these transformations. PMID:24302226

  8. Mechanism and an Improved Asymmetric Allylboration of Ketones Catalyzed by Chiral Biphenols**

    PubMed Central

    Barnett, David S.; Moquist, Philip N.; Schaus, Scott E.

    2010-01-01

    A mechanistic study of the enantioselective asymmetric allylboration of ketones with allyldiisopropoxyborane catalyzed by chiral biphenols resulted in the development of improved reaction process. In a ligand exchange process involving the chiral biphenol and the boronate to liberate isopropanol as the key step, addition of isopropanol to the reaction was found to increase the overall rate and enantioselectivity. In the design of an improved reaction, a boronate possessing a tethered alcohol would more readily liberate catalyst at the end of a reaction. The use of allyldioxaborinane with 2 mol% (S)-3,3′-Br2-BINOL and 2 equivalents t-BuOH relative to ketone at room temperature results in high yields and enantioselectivities. Insight gathered from the mechanistic investigation resulted in the development of a reaction process that uses less catalyst (from 15 mol% to 2 mol%) at warmer temperatures (from -35 °C to room temperature). PMID:19816902

  9. Ketone-body utilization by homogenates of adult rat brain

    SciTech Connect

    Lopes-Cardozo, M.; Klein, W.

    1982-06-01

    The regulation of ketone-body metabolism and the quantitative importance of ketone bodies as lipid precursors in adult rat brain has been studied in vitro. Utilization of ketone bodies and of pyruvate by homogenates of adult rat brain was measured and the distribution of /sup 14/C from (3-/sup 14/C)ketone bodies among the metabolic products was analysed. The rate of ketone-body utilization was maximal in the presence of added Krebs-cycle intermediates and uncouplers of oxidative phosphorylation. The consumption of acetoacetate was faster than that of D-3-hydroxybutyrate, whereas, pyruvate produced twice as much acetyl-CoA as acetoacetate under optimal conditions. Millimolar concentrations of ATP in the presence of uncoupler lowered the consumption of ketone bodies but not of pyruvate. Indirect evidence is presented suggesting that ATP interferes specifically with the mitochondrial uptake of ketone bodies. Interconversion of ketone bodies and the accumulation of acid-soluble intermediates (mainly citrate and glutamate) accounted for the major part of ketone-body utilization, whereas only a small part was oxidized to CO/sub 2/. Ketone bodies were not incorporated into lipids or protein. We conclude that adult rat-brain homogenates use ketone bodies exclusively for oxidative purposes.

  10. 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

  11. The Oxidation of Secondary Alcohols with Cr (VI).

    ERIC Educational Resources Information Center

    Mason, Timothy J.

    1982-01-01

    Describes experiments in which acid chromate oxidation rates of four secondary alcohols are determined and related to the differences in strain relief involved in the conversion of the alcohols to their respective ketone products. All four oxidations can be completed in a 4-hour laboratory period. (Author/JN)

  12. 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

  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. Synthesis and characterization of poly(ether ketone)s containing phosphorus and fluorine

    SciTech Connect

    Youngman, P.W.; Fitch, J.W.; Cassidy, P.E. |

    1996-10-01

    Because of the excellent properties exhibited by fluorinated poly(ether ketone)s, modifications were sought to further improve this polymer toward atomic oxygen resistance. For this purpose a phosphorous-containing monomer [bis(4-fluorophenyl)phenyl phosphine oxide] was synthesized and incorporated into a poly(ether ketone) backbone by reaction with 2,2-bis[4-(4-fluorobenzoyl)phenyl]hexafluoropropane in varying proportions with bisphenol AF to produce polymers with different amounts of the phosphine oxide repeating unit in the backbone. Colorless, film-forming materials were produced with a slight increase in Tg due to the phosphine oxide function. The incorporation of this moiety also resulted in a very small increase in the dielectric constant and an improved resistance to atomic oxygen ablation.

  16. Iron Mineral Effects on Ketone Reactions in Hydrothermal Fluids

    NASA Astrophysics Data System (ADS)

    Yang, Z.; Gould, I. R.; Shock, E.

    2011-12-01

    assist in breaking C-C bonds homolytically, generating freely diffusing radicals as intermediates at our experimental conditions. In contrast, FeS increases DBK conversion mainly by following the reduction pathway, from ketone to alcohol, alkene and alkane. As an example, the concentration of 1,3-diphenylpropane is orders of magnitude higher with FeS than with H2O alone. One major difference is that, 1,3-diphenyl-2-propanol, which is very short-lived in H2O alone, accumulates and predominates over the corresponding alkene and alkane in the first 70 hours, which suggests that the rate of transformation of DBK to the alcohol is greatly facilitated by the presence of FeS. [1] McCollom and Seewald (2007), Chem. Rev.107, 382-401.

  17. 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

  18. 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

  19. Asymmetric hydrogenation of alkynyl ketones with the η(6)-arene/TsDPEN-ruthenium(II) catalyst.

    PubMed

    Arai, Noriyoshi; Satoh, Hironori; Utsumi, Noriyuki; Murata, Kunihiko; Tsutsumi, Kunihiko; Ohkuma, Takeshi

    2013-06-21

    Enantioselective hydrogenation of alkynyl ketones catalyzed by Ru(OTf)(TsDPEN)(η(6)-p-cymene) (TsDPEN = N-(p-toluenesulfonyl)-1,2-diphenylethylenediamine) affords the propargylic alcohols in up to 97% ee. The alkynyl moieties are left intact in most cases. The reaction can be conducted with a substrate-to-catalyst molar ratio as high as 5000 under 10 atm of H2. The mode of enantioselection is elucidated with the transition state models directed by the CH/π attractive interaction between the substrate and the catalytic species. PMID:23738634

  20. Asymmetric hydrogenation of ketones: Tactics to achieve high reactivity, enantioselectivity, and wide scope

    PubMed Central

    Ohkuma, Takeshi

    2010-01-01

    Ru complexes with chiral diphosphines and amine-based ligands achieve high catalytic activity and enantioselectivity for the hydrogenation of ketones under neutral to slightly basic conditions. The chiral environment is controllable by changing the combination of these two ligands. A concerted six-membered transition state is proposed to be the origin of the high reactivity. The η6-arene/TsDPEN–Ru and MsDPEN–Cp*Ir catalysts effect the asymmetric reaction under slightly acidic conditions. A variety of chiral secondary alcohols are obtained in high enantiomeric excess. PMID:20228621

  1. Catalyst-Controlled Wacker-Type Oxidation of Homoallylic Alcohols in the Absence of Protecting Groups

    PubMed Central

    McCombs, Jessica R.; Michel, Brian W.

    2011-01-01

    Homoallylic alcohols are oxidized to β-hydroxy ketones using a TBHP-mediated Pd-catalyzed Wacker-type oxidation. The use of a bidentate ligand, quinoline-2-oxazoline (Quinox), and TBHP(aq) as the terminal oxidant provides good yields of the desired products with reaction times significantly reduced as compared to the Tsuji-Wacker oxidation. Additionally, bis- and tris-homoallylic alcohols are oxidized to provide cyclic peroxyketals, presumably via nucleophilic attack of the methyl ketone product. PMID:21446720

  2. Novel Characterization of GDI Engine Exhaust for Gasoline and Mid-Level Gasoline-Alcohol Blends

    SciTech Connect

    Storey, John Morse; Lewis Sr, Samuel Arthur; Szybist, James P; Thomas, John F; Barone, Teresa L; Eibl, Mary A; Nafziger, Eric J; Kaul, Brian C

    2014-01-01

    Gasoline direct injection (GDI) engines can offer improved fuel economy and higher performance over their port fuel-injected (PFI) counterparts, and are now appearing in increasingly more U.S. and European vehicles. Small displacement, turbocharged GDI engines are replacing large displacement engines, particularly in light-duty trucks and sport utility vehicles, in order for manufacturers to meet more stringent fuel economy standards. GDI engines typically emit the most particulate matter (PM) during periods of rich operation such as start-up and acceleration, and emissions of air toxics are also more likely during this condition. A 2.0 L GDI engine was operated at lambda of 0.91 at typical loads for acceleration (2600 rpm, 8 bar BMEP) on three different fuels; an 87 anti-knock index (AKI) gasoline (E0), 30% ethanol blended with the 87 AKI fuel (E30), and 48% isobutanol blended with the 87 AKI fuel. E30 was chosen to maximize octane enhancement while minimizing ethanol-blend level and iBu48 was chosen to match the same fuel oxygen level as E30. Particle size and number, organic carbon and elemental carbon (OC/EC), soot HC speciation, and aldehydes and ketones were all analyzed during the experiment. A new method for soot HC speciation is introduced using a direct, thermal desorption/pyrolysis inlet for the gas chromatograph (GC). Results showed high levels of aromatic compounds were present in the PM, including downstream of the catalyst, and the aldehydes were dominated by the alcohol blending.

  3. 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

  4. 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

  5. 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…

  6. 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.

  7. Michael hydratase alcohol dehydrogenase or just alcohol dehydrogenase?

    PubMed Central

    2014-01-01

    The Michael hydratase – alcohol dehydrogenase (MhyADH) from Alicycliphilus denitrificans was previously identified as a bi-functional enzyme performing a hydration of α,β-unsaturated ketones and subsequent oxidation of the formed alcohols. The investigations of the bi-functionality were based on a spectrophotometric assay and an activity staining in a native gel of the dehydrogenase. New insights in the recently discovered organocatalytic Michael addition of water led to the conclusion that the previously performed experiments to identify MhyADH as a bi-functional enzyme and their results need to be reconsidered and the reliability of the methodology used needs to be critically evaluated. PMID:24949265

  8. Intercalation of cyclic ketones into vanadyl phosphate

    SciTech Connect

    Zima, Vitezslav . E-mail: vitezslav.zima@upce.cz; Melanova, Klara; Benes, Ludvik; Trchova, Miroslava; Dybal, Jiri

    2005-01-15

    Intercalation compounds of vanadyl phosphate with cyclic ketones (cyclopentanone, cyclohexanone, 4-methylcyclohexanone, and 1,4-cyclohexanedione) were prepared from corresponding propanol or ethanol intercalates by a molecular exchange. The intercalates prepared were characterized using powder X-ray diffraction and thermogravimetric analysis. The intercalates are stable in dry environment and decompose slowly in humid air. Infrared and Raman spectra indicate that carbonyl oxygens of the guest molecules are coordinated to the vanadium atoms of the host layers. The local structure and interactions in the cyclopentanone intercalate have been suggested on the basis of quantum chemical calculations.

  9. On-line gas chromatographic analysis of higher alcohol synthesis products from syngas.

    PubMed

    Andersson, Robert; Boutonnet, Magali; Järås, Sven

    2012-07-20

    An on-line gas chromatographic (GC) system has been developed for rapid and accurate product analysis in catalytic conversion of syngas (a mixture of H₂ and CO) to alcohols, so called "higher alcohol synthesis (HAS)". Conversion of syngas to higher alcohols is an interesting second step in the route of converting coal, natural gas and possibly biomass to liquid alcohol fuel and chemicals. The presented GC system and method are developed for analysis of the products formed from syngas using alkali promoted MoS₂ catalysts, however it is not limited to these types of catalysts. During higher alcohol synthesis not only the wanted short alcohols (∼C₂-C₅) are produced, but also a great number of other products in smaller or greater amounts, they are mainly short hydrocarbons (olefins, paraffins, branched, non-branched), aldehydes, esters and ketones as well as CO₂, H₂O. Trace amounts of sulfur-containing compounds can also be found in the product effluent when sulfur-containing catalysts are used and/or sulfur-containing syngas is feed. In the presented GC system, most of them can be separated and analyzed within 60 min without the use of cryogenic cooling. Previously, product analysis in "higher alcohol synthesis" has in most cases been carried out partly on-line and partly off-line, where the light gases (gases at room temp) are analyzed on-line and liquid products (liquid at room temp) are collected in a trap for later analysis off-line. This method suffers from many drawbacks compared to a complete on-line GC system. In this paper an on-line system using an Agilent 7890 gas chromatograph equipped with two flame ionization detectors (FID) and a thermal conductivity detector (TCD), together with an Agilent 6890 with sulfur chemiluminescence dual plasma detector (SCD) is presented. A two-dimensional GC system with Deans switch (heart-cut) and two capillary columns (HP-FFAP and HP-Al₂O₃) was used for analysis of the organic products on the FIDs. Light

  10. 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...

  11. 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...

  12. 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...

  13. 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...

  14. 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...

  15. 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...

  16. 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

  17. Inborn errors of ketone body utilization.

    PubMed

    Hori, Tomohiro; Yamaguchi, Seiji; Shinkaku, Haruo; Horikawa, Reiko; Shigematsu, Yosuke; Takayanagi, Masaki; Fukao, Toshiyuki

    2015-01-01

    Succinyl-CoA:3-ketoacid CoA transferase (SCOT) deficiency and mitochondrial acetoacetyl-CoA thiolase (beta-ketothiolase or T2) deficiency are classified as autosomal recessive disorders of ketone body utilization characterized by intermittent ketoacidosis. Patients with mutations retaining no residual activity on analysis of expression of mutant cDNA are designated as severe genotype, and patients with at least one mutation retaining significant residual activity, as mild genotype. Permanent ketosis is a pathognomonic characteristic of SCOT-deficient patients with severe genotype. Patients with mild genotype, however, may not have permanent ketosis, although they may develop severe ketoacidotic episodes similar to patients with severe genotype. Permanent ketosis has not been reported in T2 deficiency. In T2-deficient patients with severe genotype, biochemical diagnosis is done on urinary organic acid analysis and blood acylcarnitine analysis to observe characteristic findings during both ketoacidosis and non-episodic conditions. In Japan, however, it was found that T2-deficient patients with mild genotype are common, and typical profiles were not identified on these analyses. Based on a clinical study of ketone body utilization disorders both in Japan and worldwide, we have developed guidelines for disease diagnosis and treatment. These diseases are treatable by avoiding fasting and by providing early infusion of glucose, which enable the patients to grow without sequelae. PMID:25559898

  18. Demonstration of Redox Potential of Metschnikowia koreensis for Stereoinversion of Secondary Alcohols/1,2-Diols

    PubMed Central

    Meena, Vachan Singh; Banoth, Linga; Banerjee, U. C.

    2014-01-01

    The present work reports the Metschnikowia koreensis-catalyzed one-pot deracemization of secondary alcohols/1,2-diols and their derivatives with in vivo cofactor regeneration. Reaction is stereoselective and proceeds with sequential oxidation of (R)-secondary alcohols to the corresponding ketones and the reduction of the ketones to (S)-secondary alcohols. Method is applicable to a repertoire of racemic aryl secondary alcohols and 1,2-diols establishing a wide range of substrate specificity of M. koreensis. This ecofriendly method afforded the product in high yield (88%) and excellent optical purity (>98% ee), minimizing the requirement of multistep reaction and expensive cofactor. PMID:24592389

  19. 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

  20. 40 CFR 721.4925 - Methyl n-butyl ketone.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Methyl n-butyl ketone. 721.4925 Section 721.4925 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.4925 Methyl n-butyl ketone....

  1. Decarboxylative dearomatization and mono-α-arylation of ketones.

    PubMed

    Mendis, Shehani N; Tunge, Jon A

    2016-06-01

    We report the first example of a palladium-catalyzed decarboxylative dearomatization reaction that occurs via Pd-π-benzyl intermediates. In fact, the Pd-catalyzed decarboxylative cross-coupling reaction of benzyl enol carbonates can lead to either the dearomatized alicyclic ketones or α-monoarylated ketone products depending on the catalyst and ligand employed. PMID:27229656

  2. IRIS TOXICOLOGICAL REVIEW OF METHYL ETHYL KETONE (2003 Final)

    EPA Science Inventory

    EPA is announcing the release of the final report, "Toxicological Review of Methyl Ethyl Ketone: in support of the Integrated Risk Information System (IRIS)". The updated Summary for Methyl Ethyl Ketone and accompanying Quickview have also been added to the IRIS Database.

  3. 21 CFR 862.1435 - Ketones (nonquantitative) test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...) test system is a device intended to identify ketones in urine and other body fluids. Identification of... Section 862.1435 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... acidity of body fluids) or ketosis (a condition characterized by increased production of ketone...

  4. 21 CFR 862.1435 - Ketones (nonquantitative) test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...) test system is a device intended to identify ketones in urine and other body fluids. Identification of... Section 862.1435 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... acidity of body fluids) or ketosis (a condition characterized by increased production of ketone...

  5. 21 CFR 862.1435 - Ketones (nonquantitative) test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...) test system is a device intended to identify ketones in urine and other body fluids. Identification of... Section 862.1435 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... acidity of body fluids) or ketosis (a condition characterized by increased production of ketone...

  6. 21 CFR 862.1435 - Ketones (nonquantitative) test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...) test system is a device intended to identify ketones in urine and other body fluids. Identification of... Section 862.1435 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... acidity of body fluids) or ketosis (a condition characterized by increased production of ketone...

  7. Production of methyl-vinyl ketone from levulinic acid

    DOEpatents

    Dumesic, James A.; West; Ryan M.

    2011-06-14

    A method for converting levulinic acid to methyl vinyl ketone is described. The method includes the steps of reacting an aqueous solution of levulinic acid, over an acid catalyst, at a temperature of from room temperature to about 1100 K. Methyl vinyl ketone is thereby formed.

  8. Dehydration, Dehydrogenation, and Condensation of Alcohols on Supported Oxide Catalysts Based on Cyclic (WO3)3 and (MoO3)3 Clusters

    SciTech Connect

    Rousseau, Roger J.; Dixon, David A.; Kay, Bruce D.; Dohnalek, Zdenek

    2014-01-01

    Supported early transition metal oxides have important applications in numerous catalytic reactions. In this article we review preparation and activity of well-defined model WO3 and MoO3 catalysts prepared via deposition of cyclic gas-phase (WO3)3 and (MoO3)3 clusters generated by sublimation of WO3 and MoO3 powders. Conversion of small aliphatic alcohols to alkenes, aldehydes/ketons, and ethers is employed to probe the structure-activity relationships on model WO3 and MoO3 catalysts ranging from unsupported (WO3)3 and (MoO3)3 clusters embedded in alcohol matrices, to (WO3)3 clusters supported on surfaces of other oxides, and epitaxial and nanoporous WO3 films. Detailed theoretical calculations reveal the underlying reaction mechanisms and provide insight into the origin of the differences in the WO3 and MoO3 reactivity. For the range of interrogated (WO3)3 they further shed light into the role structure and binding of (WO3)3 clusters with the support play in determining their catalytic activity.

  9. Murine hepatic aldehyde dehydrogenase 1a1 is a major contributor to oxidation of aldehydes formed by lipid peroxidation

    PubMed Central

    Makia, Ngome L.; Bojang, Pasano; Falkner, K. Cameron; Conklin, Daniel J.; Prough, Russell A.

    2015-01-01

    Reactive lipid aldehydes are implicated in the pathogenesis of various oxidative stress-mediated diseases, including non-alcoholic steatohepatitis, atherosclerosis, Alzheimer’s and cataract. In the present study, we sought to define which hepatic Aldh isoform plays a major role in detoxification of lipid-derived aldehydes, such as acrolein and HNE by enzyme kinetic and gene expression studies. The catalytic efficiencies for metabolism of acrolein by Aldh1a1 was comparable to that of Aldh3a1 (Vmax/Km = 23). However, Aldh1a1 exhibits far higher affinity for acrolein (Km = 23.2 μM) compared to Aldh3a1 (Km = 464 μM). Aldh1a1 displays a 3-fold higher catalytic efficiency for HNE than Aldh3a1 (218 vs 69 ml/min/mg). The endogenous Aldh1a1 gene was highly expressed in mouse liver and a liver-derived cell line (Hepa-1c1c7) compared to Aldh2, Aldh1b1 and Aldh3a1. Aldh1a1 mRNA levels was 34-fold and 73-fold higher than Aldh2 in mouse liver and Hepa-1c1c7 cells respectively. Aldh3a1 gene was absent in mouse liver, but moderately expressed in Hepa-1c1c7 cells compared to Aldh1a1. We demonstrated that knockdown of Aldh1a1 expression by siRNA caused Hepa-1c1c7 cells to be more sensitive to acrolein-induced cell death and resulted in increased accumulation of acrolein-protein adducts and caspase 3 activation. These results indicate that Aldh1a1 plays a major role in cellular defense against oxidative damage induced by reactive lipid aldehydes in mouse liver. We also noted that hepatic Aldh1a1 mRNA levels were significantly increased (≈ 3 fold) in acrolein-fed mice compared to control. In addition, hepatic cytosolic ALDH activity was induced by acrolein when 1 mM NAD+ was used as cofactor, suggesting an Aldh1a1-protective mechanism against acrolein toxicity in mice liver. Thus, mechanisms to induce Aldh1a1 gene expression may provide a useful rationale for therapeutic protection against oxidative stress-induced pathologies. PMID:21256123

  10. Reduction of exogenous ketones depends upon NADPH generated photosynthetically in cells of the cyanobacterium Synechococcus PCC 7942

    PubMed Central

    2011-01-01

    Effective utilization of photosynthetic microorganisms as potential biocatalysts is favorable for the production of useful biomaterials and the reduction of atmospheric CO2. For example, biocatalytic transformations are used in the synthesis of optically active alcohols. We previously found that ketone reduction in cells of the cyanobacterium Synechococcus PCC 7942 is highly enantioselective and remarkably enhanced under light illumination. In this study, the mechanism of light-enhanced ketone reduction was investigated in detail using several inhibitors of photosynthetic electron transport and of enzymes of the Calvin cycle. It is demonstrated that light intensity and photosynthesis inhibitors significantly affect the ketone reduction activity in Synechococcus. This indicates that the reduction correlates well with photosynthetic activity. Moreover, ketone reduction in Synechococcus specifically depends upon NADPH and not NADH. These results also suggest that cyanobacteria have the potential to be utilized as biocatalytic systems for direct usage of light energy in various applications such as syntheses of useful compounds and remediation of environmental pollutants. PMID:21906270

  11. Selective oxidation of veratryl alcohol with composites of Au nanoparticles and graphene quantum dots as catalysts.

    PubMed

    Wu, Xiaochen; Guo, Shouwu; Zhang, Jingyan

    2015-04-14

    Veratryl alcohol can be oxidized to veratryl aldehyde or veratric acid with excellent selectivity and efficient conversion under acidic and alkaline conditions using Au nanoparticles and graphene quantum dot composites (Au/GQDs) as catalysts. PMID:25760658

  12. Alcohol Alert

    MedlinePlus

    ... main content National Institute on Alcohol Abuse and Alcoholism (NIAAA) Main Menu Search Search form Search Alcohol & ... on a single aspect of alcohol abuse and alcoholism. Please click on the desired publication for full ...

  13. CNN pincer ruthenium catalysts for hydrogenation and transfer hydrogenation of ketones: experimental and computational studies.

    PubMed

    Baratta, Walter; Baldino, Salvatore; Calhorda, Maria José; Costa, Paulo J; Esposito, Gennaro; Herdtweck, Eberhardt; Magnolia, Santo; Mealli, Carlo; Messaoudi, Abdelatif; Mason, Sax A; Veiros, Luis F

    2014-10-13

    Reaction of [RuCl(CNN)(dppb)] (1-Cl) (HCNN=2-aminomethyl-6-(4-methylphenyl)pyridine; dppb=Ph2 P(CH2 )4 PPh2 ) with NaOCH2 CF3 leads to the amine-alkoxide [Ru(CNN)(OCH2 CF3 )(dppb)] (1-OCH2 CF3 ), whose neutron diffraction study reveals a short RuO⋅⋅⋅HN bond length. Treatment of 1-Cl with NaOEt and EtOH affords the alkoxide [Ru(CNN)(OEt)(dppb)]⋅(EtOH)n (1-OEt⋅n EtOH), which equilibrates with the hydride [RuH(CNN)(dppb)] (1-H) and acetaldehyde. Compound 1-OEt⋅n EtOH reacts reversibly with H2 leading to 1-H and EtOH through dihydrogen splitting. NMR spectroscopic studies on 1-OEt⋅n EtOH and 1-H reveal hydrogen bond interactions and exchange processes. The chloride 1-Cl catalyzes the hydrogenation (5 atm of H2 ) of ketones to alcohols (turnover frequency (TOF) up to 6.5×10(4) h(-1) , 40 °C). DFT calculations were performed on the reaction of [RuH(CNN')(dmpb)] (2-H) (HCNN'=2-aminomethyl-6-(phenyl)pyridine; dmpb=Me2 P(CH2 )4 PMe2 ) with acetone and with one molecule of 2-propanol, in alcohol, with the alkoxide complex being the most stable species. In the first step, the Ru-hydride transfers one hydrogen atom to the carbon of the ketone, whereas the second hydrogen transfer from NH2 is mediated by the alcohol and leads to the key "amide" intermediate. Regeneration of the hydride complex may occur by reaction with 2-propanol or with H2 ; both pathways have low barriers and are alcohol assisted. PMID:25195979

  14. A sulfonated poly (aryl ether ether ketone ketone) isomer: synthesis and DMFC performance

    SciTech Connect

    Kim, Yu Seung; Liu, Baijun; Hu, Wei; Jiang, Zhenhua; Robertson, Gilles; Guiver, Michael

    2009-01-01

    A sulfonated poly(aryl ether ether ketone ketone) (PEEKK) having a well-defined rigid homopolymer-like chemical structure was synthesized from a readily-prepared PEEKK post-sulfonation with concentrated sulfuric acid at room temperature within several hours. The polymer electrolyte membrane (PEM) cast from the resulting polymer exhibited an excellent combination of thermal resistance, oxidative and dimensional stability, low methanol fuel permeability and high proton conductivity. Furthermore, membrane electrode assemblies (MEAs) were successfully fabricated and good direct methanol fuel cell (DMFC) performance was observed. At 2 M MeOH feed, the current density at 0.5 V reached 165 mA/cm, which outperformed our reported analogues and eveluated Nafion membranes.

  15. 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

  16. 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

  17. Revisiting the Meerwein-Ponndorf-Verley Reduction: A Sustainable Protocol for Transfer Hydrogenation of Aldehydes and Ketones

    EPA Science Inventory

    The metal-catalyzed transfer hydrogenation of carbonyl compounds has received much interest because of the immense number of opportunities that exist to prepare high-value products. This reaction is featured in numerous multi-step organic syntheses and is arguably the most import...

  18. LEWIS ACID-CATALYZED REACTIONS IN PROTIC MEDIA - LANTHANIDE-CATALYZED REACTIONS OF INDOLES WITH ALDEHYDES OR KETONES. (R826123)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  19. Determination of aldehydes and ketones with high atmospheric reactivity on diesel exhaust using a biofuel from animal fats

    NASA Astrophysics Data System (ADS)

    Ballesteros, R.; Monedero, E.; Guillén-Flores, J.

    2011-05-01

    Biodiesel from animal fats appears as an alternative for conventional diesel in automotive consumption. Animal fats are classified into three categories, although only one of them can be used for biodiesel production, according to regulation. Due to its novelty, researchers testing animal-fat biodiesel on diesel engines focus only on regulated emissions. In this paper, the experiments carried out analyze carbonyl compounds emissions, due to its highly atmospheric reactivity, to complete the characterization of the total emissions in this kind of biofuel. Two fuels, a reference petro-diesel and a pure animal-fat biodiesel, were tested in a 4-cylinder, direct injection, diesel engine Nissan Euro 5 M1D-Bk. Samples were collected in 4 different operating modes and 3 points along the exhaust line. The analyses of samples were made in a high performance liquid chromatography, following the method recommended by the CARB to analyze air quality. Results show, on the one hand, a significant rise in carbonyl emissions, almost three times at the mode with highest hydrocarbon emissions, when biodiesel is used. On the other hand, on average, a reduction of 90% of carbonyl emissions when exhaust gases go through the different post-treatment systems installed. Despite this reduction, specific reactivity does not decrease substantially.

  20. Alcoholism, Alcohol, and Drugs

    ERIC Educational Resources Information Center

    Rubin, Emanuel; Lieber, Charles S.

    1971-01-01

    Describes research on synergistic effects of alcohol and other drugs, particularly barbiturates. Proposes biochemical mechanisms to explain alcoholics' tolerance of other drugs when sober, and increased sensitivity when drunk. (AL)

  1. 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

  2. Engineering of Bacterial Methyl Ketone Synthesis for Biofuels

    PubMed Central

    Goh, Ee-Been; Baidoo, Edward E. K.; Keasling, Jay D.

    2012-01-01

    We have engineered Escherichia coli to overproduce saturated and monounsaturated aliphatic methyl ketones in the C11 to C15 (diesel) range; this group of methyl ketones includes 2-undecanone and 2-tridecanone, which are of importance to the flavor and fragrance industry and also have favorable cetane numbers (as we report here). We describe specific improvements that resulted in a 700-fold enhancement in methyl ketone titer relative to that of a fatty acid-overproducing E. coli strain, including the following: (i) overproduction of β-ketoacyl coenzyme A (CoA) thioesters achieved by modification of the β-oxidation pathway (specifically, overexpression of a heterologous acyl-CoA oxidase and native FadB and chromosomal deletion of fadA) and (ii) overexpression of a native thioesterase (FadM). FadM was previously associated with oleic acid degradation, not methyl ketone synthesis, but outperformed a recently identified methyl ketone synthase (Solanum habrochaites MKS2 [ShMKS2], a thioesterase from wild tomato) in β-ketoacyl-CoA-overproducing strains tested. Whole-genome transcriptional (microarray) studies led to the discovery that FadM is a valuable catalyst for enhancing methyl ketone production. The use of a two-phase system with decane enhanced methyl ketone production by 4- to 7-fold in addition to increases from genetic modifications. PMID:22038610

  3. Substrate-controlled Michael additions of chiral ketones to enones.

    PubMed

    Fàbregas, Mireia; Gómez-Palomino, Alejandro; Pellicena, Miquel; Reina, Daniel F; Romea, Pedro; Urpí, Fèlix; Font-Bardia, Mercè

    2014-12-01

    Substrate-controlled Michael additions of the titanium(IV) enolate of lactate-derived ketone 1 to acyclic α,β-unsaturated ketones in the presence of a Lewis acid (TiCl4 or SnCl4) provide the corresponding 2,4-anti-4,5-anti dicarbonyl compounds in good yields and excellent diastereomeric ratios. Likely, the nucleophilic species involved in such additions are bimetallic enolates that may add to enones through cyclic transition states. Finally, further studies indicate that a structurally related β-benzyloxy chiral ketone can also participate in such stereocontrolled conjugate additions. PMID:25423031

  4. Point-of-Care Glucose and Ketone Monitoring.

    PubMed

    Chong, Siew Kim; Reineke, Erica L

    2016-03-01

    Early and rapid identification of hypo- and hyperglycemia as well as ketosis is essential for the practicing veterinarian as these conditions can be life threatening and require emergent treatment. Point-of-care testing for both glucose and ketone is available for clinical use and it is important for the veterinarian to understand the limitations and potential sources of error with these tests. This article discusses the devices used to monitor blood glucose including portable blood glucose meters, point-of-care blood gas analyzers and continuous glucose monitoring systems. Ketone monitoring options discussed include the nitroprusside reagent test strips and the 3-β-hydroxybutyrate ketone meter. PMID:27451045

  5. Practical and Broadly Applicable Catalytic Enantioselective Additions of Allyl-B(pin) Compounds to Ketones and α-Ketoesters.

    PubMed

    Robbins, Daniel W; Lee, KyungA; Silverio, Daniel L; Volkov, Alexey; Torker, Sebastian; Hoveyda, Amir H

    2016-08-01

    A set of broadly applicable methods for efficient catalytic additions of easy-to-handle allyl-B(pin) (pin=pinacolato) compounds to ketones and acyclic α-ketoesters was developed. Accordingly, a large array of tertiary alcohols can be obtained in 60 to >98 % yield and up to 99:1 enantiomeric ratio. At the heart of this development is rational alteration of the structures of the small-molecule aminophenol-based catalysts. Notably, with ketones, increasing the size of a catalyst moiety (tBu to SiPh3 ) results in much higher enantioselectivity. With α-ketoesters, on the other hand, not only does the opposite hold true, since Me substitution leads to substantially higher enantioselectivity, but the sense of the selectivity is reversed as well. PMID:27273249

  6. Coulometric generation of hydrogen ions by oxidation of mercury in methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone.

    PubMed

    Mihajlović, R P; Joksimović, V M; Mihajlović, Lj V

    2003-11-01

    Mercury(II)-chloride reacts with anhydrous methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone in a precise stoichiometry ratio (1:2), and weakly ionized compounds of mercury with ketones are formed and equivalent quantity of HCl is released. The application of a mercury anode for the quantitative generation of H(+) ions in 0.25 M sodium perchlorate in anhydrous methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone has been investigated. Current/potentials curves for the solvents, titrated bases, indicator and mercury showed that in these solvents mercury is oxidized at potentials much more negative than those for the titrated bases and other components present in the solution. The protons generated in this way have been used for the titration of some organic bases, with either visual or potentiometric end-point detection. The oxidation of mercury in methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone and the reaction of mercury ions with these solvents have been found to proceed with 100% current efficiency. PMID:18969192

  7. ABA-alcohol is an intermediate in abscisic acid biosynthesis

    SciTech Connect

    Rock, C.D.; Zeevaart, J.A.D. )

    1990-05-01

    It has been established that ABA-aldehyde is a precursor to ABA. The ABA-deficient flacca and sitiens mutants of tomato are blocked in the conversion of ABA-aldehyde to ABA, and accumulate trans-ABA-alcohol. {sup 18}O-Labeling studies of ABA in flacca and sitiens show that these mutants synthesize a large percentage of ({sup 18}O)ABA which contains two {sup 18}O atoms in the carboxyl group. Furthermore, the mutants synthesize much greater amounts of trans-ABA-glucose ester (t-ABA-GE) compared with the wild type, and this ({sup 18}O)t-ABA-GE is also double labeled in the carboxyl group. Our interpretation of these data is that the {sup 18}O in ABA-aldehyde is trapped in the side chain by reduction to ({sup 18}O)ABA-alcohol, followed by isomerization to ({sup 18}O)t-ABA-alcohol and oxidation with {sup 18}O{sub 2} to ({sup 18}O)t-ABA. The ({sup 18}O)t-ABA is then rapidly converted to ({sup 18}O)t-ABA-GE. Because ({sup 18}O)ABA doubly labeled in the carboxyl group has been observed in small amounts in labeling experiments with several species, and various species have been shown to convert ABA-aldehyde to ABA-alcohol and t-ABA-alcohol, we propose that ABA-alcohol is an ABA intermediate in a shunt pathway.

  8. Characterization of alcohol dehydrogenase 1 and 3 from Neurospora crassa FGSC2489.

    PubMed

    Park, Yong-Cheol; San, Ka-Yiu; Bennett, George N

    2007-08-01

    Alcohol dehydrogenase (ADH) is a key enzyme in the production and utilization of alcohols. Some also catalyze the formation of carboxylate esters from alcohols and aldehydes. The ADH1 and ADH3 genes of Neurospora crassa FGSC2489 were cloned and expressed in recombinant Escherichia coli to investigate their alcohol dehydrogenation and carboxylate ester formation abilities. Homology analysis and sequence alignment of amino acid sequence indicated that ADH1 and ADH3 of N. crassa contained a zinc-binding consensus sequence and a NAD(+)-binding motif and showed 54-75% identity with fungi ADHs. N. crassa ADH1 was expressed in E. coli to give a specific activity of 289 +/- 9 mU/mg using ethanol and NAD(+) as substrate and cofactor, respectively. Corresponding experiments on the expression and activity of ADH3 gave 4 mU/mg of specific activity. N. crassa ADH1 preferred primary alcohols containing C3-C8 carbons to secondary alcohols such as 2-propanol and 2-butanol. N. crassa ADH1 possessed 5.3 mU/mg of specific carboxylate ester-forming activity accumulating 0.4 mM of ethyl acetate in 18 h. Substrate specificity of various linear alcohols and aldehydes indicated that short chain-length alcohols and aldehydes were good substrates for carboxylate ester production. N. crassa ADH1 was a primary alcohol dehydrogenase using cofactor NAD(+) preferably and possessed carboxylate ester-forming activity with short chain alcohols and aldehydes. PMID:17516063

  9. 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

  10. Oxidative acetoxylation of the silyl ethers of ketone enols

    SciTech Connect

    Brunovlenskaya, I.I.; Kusainova, K.M.; Kashin, A.K.

    1988-07-20

    The authors studied the reaction of (dicarboxyiodo)benzenes with the trimethylsilyl ethers of ketone enols having various structures. They also undertook a comparative investigation of the oxidation of these compounds with lead tetraacetate. The reaction of (diacetoxyiodo)benzene with the trimethylsilyl ethers of ketone enols takes place with retention of the (CH/sub 3/)/sub 3/Si group in two directions, i.e., substitution of the vinylic hydrogen or diacetoxylation of the double bond. The reaction can be used for the regioselective synthesis of /alpha/-acetoxy ketones, since the trimethylsilyl group is readily eliminated from the obtained products by the action of fluoride ion or boron trifluoride etherate with the formation of the corresponding substituted ketones.

  11. 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

  12. 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

  13. Alcohol Alert

    MedlinePlus

    ... Us You are here Home » Alcohol Alert Alcohol Alert The NIAAA Alcohol Alert is a quarterly bulletin that disseminates important research ... text. To order single copies of select Alcohol Alerts, see ordering Information . To view publications in PDF ...

  14. Alcoholism - resources

    MedlinePlus

    Resources - alcoholism ... The following organizations are good resources for information on alcoholism : Alcoholics Anonymous -- www.aa.org Al-Anon/Alateen -- www.al-anon.org/home National Institute on Alcohol ...

  15. Alcoholic ketoacidosis

    MedlinePlus

    Ketoacidosis - alcoholic ... Alcoholic ketoacidosis is caused by very heavy alcohol use. It most often occurs in a malnourished person ... Symptoms of alcoholic ketoacidosis include: Nausea and vomiting ... Changed level of alertness, which may lead to coma Confusion ...

  16. Alcohol Facts

    MedlinePlus

    ... raquo Alcohol Facts Alcohol Facts Listen Drinks like beer, malt liquor, wine, and hard liquor contain alcohol. Alcohol is the ingredient that gets you drunk. Hard liquor—such as whiskey, rum, or gin—has more ...

  17. Alcoholic neuropathy

    MedlinePlus

    Neuropathy - alcoholic; Alcoholic polyneuropathy ... The exact cause of alcoholic neuropathy is unknown. It likely includes both a direct poisoning of the nerve by the alcohol and the effect of poor nutrition ...

  18. Copper/Manganese Cocatalyzed Oxidative Coupling of Vinylarenes with Ketones.

    PubMed

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

    2015-09-18

    A novel copper/manganese cocatalyzed direct oxidative coupling of terminal vinylarenes with ketones via C(sp(3))-H bond functionalization following C-C bond formation has been developed using tert-butyl hydroperoxide as the radical initiator. Various ketones underwent a free-radical addition of terminal vinylarenes to give the corresponding 1,4-dicarbonyl products with excellent regioselectivity and efficiency through one step. A possible reaction mechanism has been proposed. PMID:26348870

  19. Rotational Spectroscopy of Methyl Vinyl Ketone

    NASA Astrophysics Data System (ADS)

    Zakharenko, Olena; Motiyenko, R. A.; Aviles Moreno, Juan-Ramon; Huet, T. R.

    2015-06-01

    Methyl vinyl ketone, MVK, along with previously studied by our team methacrolein, is a major oxidation product of isoprene, which is one of the primary contributors to annual global VOC emissions. In this talk we present the analysis of the rotational spectrum of MVK recorded at room temperature in the 50 -- 650 GHz region using the Lille spectrometer. The spectroscopic characterization of MVK ground state will be useful in the detailed analysis of high resolution infrared spectra. Our study is supported by high level quantum chemical calculations to model the structure of the two stable s-trans and s-cis conformers and to obtain the harmonic force field parameters, internal rotation barrier heights, and vibrational frequencies. In the Doppler-limited spectra the splittings due to the internal rotation of methyl group are resolved, therefore for analysis of this molecule we used the Rho-Axis-Method Hamiltonian and RAM36 code to fit the rotational transitions. At the present time the ground state of two conformers is analyzed. Also we intend to study some low lying excited states. The analysis is in progress and the latest results will be presented. Support from the French Laboratoire d'Excellence CaPPA (Chemical and Physical Properties of the Atmosphere) through contract ANR-10-LABX-0005 of the Programme d'Investissements d'Avenir is acknowledged.

  20. β-Keto esters from ketones and ethyl chloroformate: a rapid, general, efficient synthesis of pyrazolones and their antimicrobial, in silico and in vitro cytotoxicity studies

    PubMed Central

    2013-01-01

    Background Pyrazolones are traditionally synthesized by the reaction of β-keto esters with hydrazine and its derivatives. There are methods to synthesize β-keto esters from esters and aldehydes, but these methods have main limitation in varying the substituents. Often, there are a number of methods such as acylation of enolates in which a chelating effect has been employed to lock the enolate anion using lithium and magnesium salts; however, these methods suffer from inconsistent yields in the case of aliphatic acylation. There are methods to synthesize β-keto esters from ketones like caboxylation of ketone enolates using carbon dioxide and carbon monoxide sources in the presence of palladium or transition metal catalysts. Currently, the most general and simple method to synthesize β-keto ester is the reaction of dimethyl or ethyl carbonate with ketone in the presence of strong bases which also requires long reaction time, use of excessive amount of reagent and inconsistent yield. These factors lead us to develop a simple method to synthesize β-keto esters by changing the base and reagent. Results A series of β-keto esters were synthesized from ketones and ethyl chloroformate in the presence of base which in turn are converted to pyrazolones and then subjected to cytotoxicity studies towards various cancer cell lines and antimicrobial activity studies towards various bacterial and fungal strains. Conclusion The β-keto esters from ethyl chloroformate was successfully attempted, and the developed method is simple, fast and applicable to the ketones having the alkyl halogens, protecting groups like Boc and Cbz that were tolerated and proved to be useful in the synthesis of fused bicyclic and tricyclic pyrazolones efficiently using cyclic ketones. Since this method is successful for different ketones, it can be useful for the synthesis of pharmaceutically important pyrazolones also. The synthesized pyrazolones were subjected to antimicrobial, docking and

  1. 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

  2. Alcohol Alert: Genetics of Alcoholism

    MedlinePlus

    ... and Reports » Alcohol Alert » Alcohol Alert Number 84 Alcohol Alert Number 84 Print Version The Genetics of ... immune defense system. Genes Encoding Enzymes Involved in Alcohol Breakdown Some of the first genes linked to ...

  3. Aldehyde Dehydrogenase 1a1 Mediates a GABA Synthesis Pathway in Midbrain Dopaminergic Neurons

    PubMed Central

    Kim, Jae-Ick; Ganesan, Subhashree; Luo, Sarah X.; Wu, Yu-Wei; Park, Esther; Huang, Eric J.; Chen, Lu; Ding, Jun B.

    2016-01-01

    Midbrain dopamine neurons are an essential component of the basal ganglia circuitry, playing key roles in the control of fine movement and reward. Recently, it has been demonstrated that γ-aminobutyric acid (GABA), the chief inhibitory neurotransmitter, is co-released by dopamine neurons. Here we show that GABA corelease in dopamine neurons does not utilize the conventional GABA synthesizing enzymes, glutamate decarboxylases GAD65 and GAD67. Our experiments reveal an evolutionarily conserved GABA synthesis pathway mediated by aldehyde dehydrogenase 1a1 (ALDH1a1). Moreover, GABA co-release is modulated by ethanol at binge drinking blood alcohol concentrations and diminished ALDH1a1 leads to enhanced alcohol consumption and preference. These findings provide insights into the functional role of GABA co-release in midbrain dopamine neurons, which may be essential for reward-based behavior and addiction. PMID:26430123

  4. Method for producing hydrocarbon and alcohol mixtures. [Patent application

    DOEpatents

    Compere, A.L.; Googin, J.M.; Griffith, W.L.

    1980-12-01

    It is an object of this invention to provide an efficient process for extracting alcohols and ketones from an aqueous solution containing the same into hydrocarbon fuel mixtures, such as gasoline, diesel fuel and fuel oil. Another object of the invention is to provide a mixture consisting of hydrocarbon, alcohols or ketones, polyoxyalkylene polymer and water which can be directly added to fuels or further purified. The above stated objects are achieved in accordance with a preferred embodiment of the invention by contacting an aqueous fermentation liquor with a hydrocarbon or hydrocarbon mixture containing carbon compounds having 5 to 18 carbon atoms, which may include gasoline, diesel fuel or fuel oil. The hydrocarbon-aqueous alcohol solution is mixed in the presence or one or more of a group of polyoxyalkylene polymers described in detail hereinafter; the fermentation alcohol being extracted into the hydrocarbon fuel-polyoxyalkylene polymer mixture.

  5. Studies on Crystalline Structure of Poly(aryl ether ketone ketone) Copolymer

    NASA Astrophysics Data System (ADS)

    Honigfort, P. S.; Ho, R. M.; Cheng, S. Z. D.

    1998-03-01

    Recent studies on the Poly(aryl ether ketone ketone) [PEKK(T/I)] copolymer containing alternating terphthalic acid (T) and isopthalic acid (I) linked phenylene units have left unanswered polymorphic questions. To help answer these questions a PEKK(T/I) oligomer was prepared and its crystal structure was investigated and compared to results from the copolymer. Evidence was found for 3 different crystal forms. When the copolymer is crystallized near 300 C, only one orthorhombic unit cell (form I) forms, and these crystals are also evident in the oligomer. At crystallization temperatures below 210 C, another crystal unit cell (form II) occurs which can also be isolated in the oligomer. Also, evidence for a new form (form III), which coexists with both form I and II was identified in both the copolymer and the oligomer between 200 and 280 C. Evidence of a larger supercell symmetry consisting of 3 unit cells staggered in the a-axis dimension was seen in electron diffraction studies of form III. This research was supported by WSFDMR(96-17030).

  6. Purification, Characterization, and Potential Bacterial Wax Production Role of an NADPH-Dependent Fatty Aldehyde Reductase from Marinobacter aquaeolei VT8▿ †

    PubMed Central

    Wahlen, Bradley D.; Oswald, Whitney S.; Seefeldt, Lance C.; Barney, Brett M.

    2009-01-01

    Wax esters, ester-linked fatty acids and long-chain alcohols, are important energy storage compounds in select bacteria. The synthesis of wax esters from fatty acids is proposed to require the action of a four-enzyme pathway. An essential step in the pathway is the reduction of a fatty aldehyde to the corresponding fatty alcohol, although the enzyme responsible for catalyzing this reaction has yet to be identified in bacteria. We report here the purification and characterization of an enzyme from the wax ester-accumulating bacterium Marinobacter aquaeolei VT8, which is a proposed fatty aldehyde reductase in this pathway. The enzyme, a 57-kDa monomer, was expressed in Escherichia coli as a fusion protein with the maltose binding protein on the N terminus and was purified to near homogeneity by using amylose affinity chromatography. The purified enzyme was found to reduce a number of long-chain aldehydes to the corresponding alcohols coupled to the oxidation of NADPH. The highest specific activity was observed for the reduction of decanal (85 nmol decanal reduced/min/mg). Short-chain and aromatic aldehydes were not substrates. The enzyme showed no detectable catalysis of the reverse reaction, the oxidation of decanol by NADP+. The mechanism of the enzyme was probed with several site-specific chemical probes. The possible uses of this enzyme in the production of wax esters are discussed. PMID:19270127

  7. Light induced controlled release of fragrances by Norrish type II photofragmentation of alkyl phenyl ketones.

    PubMed

    Levrand, Barbara; Herrmann, Andreas

    2002-11-01

    The use of alkyl phenyl ketones as delivery systems for the controlled release of fragrances was investigated by photoirradiation of undegassed solutions with a xenon lamp as well as natural sunlight. A large variety of precursor compounds was prepared efficiently in a few reaction steps from commercially available starting materials. The Norrish type II photofragmentation was found to be the predominant reaction pathway to yield the desired perfumery alkenes and acetophenones in polar and apolar solution. Systematic GC-MS analysis of the irradiated solutions allowed identification of a series of side products that are due to the presence of oxygen. A detailed analysis of the product distribution after irradiation was carried out for a series of 4-alkoxy-1-phenylbutanone derivatives. Besides the expected acetophenones, vinyl ethers and phenylcyclobutanols, the formation of alkyl formates, alcohols and 4-oxo-4-phenylbutanoates was observed. The product distribution as influenced by solvent polarity, precursor concentration and substituent effects was investigated. The utility of alkyl phenyl ketones as precursors for the light induced controlled release of fragrances under natural daylight conditions was also demonstrated. PMID:12659532

  8. NHC-Copper(I) Halide-Catalyzed Direct Alkynylation of Trifluoromethyl Ketones on Water.

    PubMed

    Czerwiński, Paweł; Molga, Edyta; Cavallo, Luigi; Poater, Albert; Michalak, Michał

    2016-06-01

    An efficient and easily scalable NHC-copper(I) halide-catalyzed addition of terminal alkynes to 1,1,1-trifluoromethyl ketones, carried out on water for the first time, is reported. A series of addition reactions were performed with as little as 0.1-2.0 mol % of [(NHC)CuX] (X=Cl, Br, I, OAc, OTf) complexes, providing tertiary propargylic trifluoromethyl alcohols in high yields and with excellent chemoselectivity from a broad range of aryl- and more challenging alkyl-substituted trifluoromethyl ketones (TFMKs). DFT calculations were performed to rationalize the correlation between the yield of catalytic alkynylation and the sterics of N-heterocyclic carbenes (NHCs), expressed as buried volume (%VBur), indicating that steric effects dominate the yield of the reaction. Additional DFT calculations shed some light on the differential reactivity of [(NHC)CuX] complexes in the alkynylation of TFMKs. The first enantioselective version of a direct alkynylation in the presence of C1 -symmetric NHC-copper(I) complexes is also presented. PMID:27142642

  9. Alda-1 is an agonist and chemical chaperone for the common human aldehyde dehydrogenase 2 variant

    SciTech Connect

    Perez-Miller, Samantha; Younus, Hina; Vanam, Ram; Chen, Che-Hong; Mochly-Rosen, Daria; Hurley, Thomas D.

    2010-04-19

    In approximately one billion people, a point mutation inactivates a key detoxifying enzyme, aldehyde dehydrogenase (ALDH2). This mitochondrial enzyme metabolizes toxic biogenic and environmental aldehydes, including the endogenously produced 4-hydroxynonenal (4HNE) and the environmental pollutant acrolein, and also bioactivates nitroglycerin. ALDH2 is best known, however, for its role in ethanol metabolism. The accumulation of acetaldehyde following the consumption of even a single alcoholic beverage leads to the Asian alcohol-induced flushing syndrome in ALDH2*2 homozygotes. The ALDH2*2 allele is semidominant, and heterozygotic individuals show a similar but less severe phenotype. We recently identified a small molecule, Alda-1, that activates wild-type ALDH2 and restores near-wild-type activity to ALDH2*2. The structures of Alda-1 bound to ALDH2 and ALDH2*2 reveal how Alda-1 activates the wild-type enzyme and how it restores the activity of ALDH2*2 by acting as a structural chaperone.

  10. 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...

  11. Extraction of protactinium from mineral acid-alcohol media.

    PubMed

    Alian, A; Sanad, W; Shabana, R

    1968-07-01

    The extraction of protactinium with organic solvents has been investigated in the presence of water-miscible alcohols and acetone. These additives were found to increase considerably the extraction of protactinium in the cases of trilaurylamine, tributyl phosphate and isobutyl methyl ketone. The influence was less in the case of thenoyltrifluoroacetone. In mixtures of an acid with various alcohols, the influence depended on the alcohol concentration, the acidity and on the chain lengths and dielectric constants of the alcohol introduced into the extraction system. PMID:18960346

  12. Ruthenium catalyzed C-C bond formation via transfer hydrogenation: branch-selective reductive coupling of allenes to paraformaldehyde and higher aldehydes.

    PubMed

    Ngai, Ming-Yu; Skucas, Eduardas; Krische, Michael J

    2008-07-01

    Under the conditions of ruthenium-catalyzed transfer hydrogenation employing 2-propanol as the terminal reductant, 1,1-disubstituted allenes 1a- h engage in reductive coupling to paraformaldehyde to furnish homoallylic alcohols 2a- h. Under identical transfer hydrogenation conditions, 1,1-disubstituted allenes engage in reductive coupling to aldehydes 3a- f to furnish homoallylic alcohols 4a- n. In all cases, reductive coupling occurs with branched regioselectivity to deliver homoallylic alcohols bearing all-carbon quaternary centers. PMID:18533665

  13. Opening of the cyclopropane ring in. cap alpha. -bromocyclopropyl ketones by the action of triphenylphosphine

    SciTech Connect

    Kulinkovich, O.G.; Tishchenko, I.G.; Sviridov, S.V.

    1987-10-10

    The reaction of a series of ..cap alpha..-bromocylopropyl ketones substituted in the three-membered ring with triphenylphosphine in alcohols in the presence of catalytic amounts of hydrochloric acid leads to the formation of the products from opening of the cyclopropane ring. Under analogous conditions 1-benzoyl-1-bromocyclopropane undergoes reductive dehalogenation. In boiling methanol 7-exo-benzoylbicyclo(4.1.0)heptane is converted into trans-1-bromo-2-benzoyl-methylcyclohexane by the action of a mixture of triphenylphosphine and 1-benzoyl-1-bromocyclopropane and also by a mixture of triphenylphosphine and carbon tetrabromide. The PMR spectra of solutions of the substances in carbon tetrachloride were obtained on a Tesla BS-467A instrument at 60 MHz and in deuterochloroform on a Bruker-360 instrument at 360 MHz with HMDS as internal standard. The IR spectra of solutions of the substances in carbon tetrachloride were recorded on a Specord IR-75 spectrophotometer.

  14. 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.

  15. 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

  16. 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

  17. Cerebral metabolic adaptation and ketone metabolism after brain injury

    PubMed Central

    Prins, Mayumi L

    2010-01-01

    The developing central nervous system has the capacity to metabolize ketone bodies. It was once accepted that on weaning, the ‘post-weaned/adult’ brain was limited solely to glucose metabolism. However, increasing evidence from conditions of inadequate glucose availability or increased energy demands has shown that the adult brain is not static in its fuel options. The objective of this review is to summarize the body of literature specifically regarding cerebral ketone metabolism at different ages, under conditions of starvation and after various pathologic conditions. The evidence presented supports the following findings: (1) there is an inverse relationship between age and the brain’s capacity for ketone metabolism that continues well after weaning; (2) neuroprotective potentials of ketone administration have been shown for neurodegenerative conditions, epilepsy, hypoxia/ischemia, and traumatic brain injury; and (3) there is an age-related therapeutic potential for ketone as an alternative substrate. The concept of cerebral metabolic adaptation under various physiologic and pathologic conditions is not new, but it has taken the contribution of numerous studies over many years to break the previously accepted dogma of cerebral metabolism. Our emerging understanding of cerebral metabolism is far more complex than could have been imagined. It is clear that in addition to glucose, other substrates must be considered along with fuel interactions, metabolic challenges, and cerebral maturation. PMID:17684514

  18. Contribution of liver alcohol dehydrogenase to metabolism of alcohols in rats.

    PubMed

    Plapp, Bryce V; Leidal, Kevin G; Murch, Bruce P; Green, David W

    2015-06-01

    The kinetics of oxidation of various alcohols by purified rat liver alcohol dehydrogenase (ADH) were compared with the kinetics of elimination of the alcohols in rats in order to investigate the roles of ADH and other factors that contribute to the rates of metabolism of alcohols. Primary alcohols (ethanol, 1-propanol, 1-butanol, 2-methyl-1-propanol, 3-methyl-1-butanol) and diols (1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol) were eliminated in rats with zero-order kinetics at doses of 5-20 mmol/kg. Ethanol was eliminated most rapidly, at 7.9 mmol/kgh. Secondary alcohols (2-propanol-d7, 2-propanol, 2-butanol, 3-pentanol, cyclopentanol, cyclohexanol) were eliminated with first order kinetics at doses of 5-10 mmol/kg, and the corresponding ketones were formed and slowly eliminated with zero or first order kinetics. The rates of elimination of various alcohols were inhibited on average 73% (55% for 2-propanol to 90% for ethanol) by 1 mmol/kg of 4-methylpyrazole, a good inhibitor of ADH, indicating a major role for ADH in the metabolism of the alcohols. The Michaelis kinetic constants from in vitro studies (pH 7.3, 37 °C) with isolated rat liver enzyme were used to calculate the expected relative rates of metabolism in rats. The rates of elimination generally increased with increased activity of ADH, but a maximum rate of 6±1 mmol/kg h was observed for the best substrates, suggesting that ADH activity is not solely rate-limiting. Because secondary alcohols only require one NAD(+) for the conversion to ketones whereas primary alcohols require two equivalents of NAD(+) for oxidation to the carboxylic acids, it appears that the rate of oxidation of NADH to NAD(+) is not a major limiting factor for metabolism of these alcohols, but the rate-limiting factors are yet to be identified. PMID:25641189

  19. Characterization of two novel alcohol short-chain dehydrogenases/reductases from Ralstonia eutropha H16 capable of stereoselective conversion of bulky substrates.

    PubMed

    Magomedova, Zalina; Grecu, Andreea; Sensen, Christoph W; Schwab, Helmut; Heidinger, Petra

    2016-03-10

    Biocatalysis has significant advantages over organic synthesis in the field of chiral molecule production and several types of stereoselective enzymes are already in use in industrial biotechnology. However, there is still a high demand for new enzymes capable of transforming bulky molecules with sufficient operability. In order to reveal novel high-potential biocatalysts, the complete genome of the β-proteobacterium Ralstonia eutropha H16 was screened for potential short-chain dehydrogenases/reductases (SDRs). We were able to identify two (S)-enantioselective SDRs named A5 and B3. These showed clear preference towards long-chain and aromatic secondary alcohols, aldehydes and ketones, with diaryl diketone benzil as one of the best substrates. In addition the phylogenetic analysis of all enzyme types, which are known to facilitate benzil reduction, revealed at least two separate evolutionary clusters. Our results indicate the biotechnological potential of SDRs A5 and B3 for the production of chiral compounds with potential commercial value. PMID:26812656

  20. Biogenic aldehyde determination by reactive paper spray ionization mass spectrometry.

    PubMed

    Bag, Soumabha; Hendricks, P I; Reynolds, J C; Cooks, R G

    2015-02-20

    Ionization of aliphatic and aromatic aldehydes is improved by performing simultaneous chemical derivatization using 4-aminophenol to produce charged iminium ions during paper spray ionization. Accelerated reactions occur in the microdroplets generated during the paper spray ionization event for the tested aldehydes (formaldehyde, n-pentanaldehyde, n-nonanaldehyde, n-decanaldehyde, n-dodecanaldehyde, benzaldehyde, m-anisaldehyde, and p-hydroxybenzaldehyde). Tandem mass spectrometric analysis of the iminium ions using collision-induced dissociation demonstrated that straight chain aldehydes give a characteristic fragment at m/z 122 (shown to correspond to protonated 4-(methyleneamino)phenol), while the aromatic aldehyde iminium ions fragment to give a characteristic product ion at m/z 120. These features allow straightforward identification of linear and aromatic aldehydes. Quantitative analysis of n-nonaldehyde using a benchtop mass spectrometer demonstrated a linear response over 3 orders of magnitude from 2.5 ng to 5 μg of aldehyde loaded on the filter paper emitter. The limit of detection was determined to be 2.2 ng for this aldehyde. The method had a precision of 22%, relative standard deviation. The experiment was also implemented using a portable ion trap mass spectrometer. PMID:25682245

  1. Third international symposium on alcohol fuels technology

    SciTech Connect

    1980-04-01

    At the opening of the Symposium, Dr. Sharrah, Senior Vice President of Continental Oil Company, addressed the attendees, and his remarks are included in this volume. The Symposium was concluded by workshops which addressed specific topics. The topical titles are as follows: alcohol uses; production; environment and safety; and socio-economic. The workshops reflected a growing confidence among the attendees that the alcohols from coal, remote natural gas and biomass do offer alternatives to petroleum fuels. Further, they may, in the long run, prove to be equal or superior to the petroleum fuels when the aspects of performance, environment, health and safety are combined with the renewable aspect of the biomass derived alcohols. Although considerable activity in the production and use of alcohols is now appearing in many parts of the world, the absence of strong, broad scale assessment and support for these fuels by the United States Federal Government was a noted point of concern by the attendees. The environmental consequence of using alcohols continues to be more benign in general than the petroleum based fuels. The exception is the family of aldehydes. Although the aldehydes are easily suppressed by catalysts, it is important to understand their production in the combustion process. Progress is being made in this regard. Of course, the goal is to burn the alcohols so cleanly that catalytic equipment can be eliminated. Separate abstracts are prepared for the Energy Data Base for individual presentations.

  2. Alcoholic ketoacidosis

    MedlinePlus

    ... attention improves the overall outlook. How severe the alcoholism is, and the presence of liver disease or ... A.M. Editorial team. Related MedlinePlus Health Topics Alcoholism and Alcohol Abuse Browse the Encyclopedia A.D. ...

  3. Alcohol withdrawal

    MedlinePlus

    ... counseling to discuss the long-term issue of alcoholism Testing and treatment for other medical problems linked ... following organizations are good resources for information on alcoholism: Alcoholics Anonymous -- www.aa.org Al-Anon/Alateen -- ...

  4. Alcoholic neuropathy

    MedlinePlus

    ... objects in the shoes Guarding the extremities to prevent injury from pressure Alcohol must be stopped to prevent the damage from ... The only way to prevent alcoholic neuropathy is not to drink excessive amounts of alcohol.

  5. Obligate Role for Ketone Body Oxidation in Neonatal Metabolic Homeostasis*

    PubMed Central

    Cotter, David G.; d'Avignon, D. André; Wentz, Anna E.; Weber, Mary L.; Crawford, Peter A.

    2011-01-01

    To compensate for the energetic deficit elicited by reduced carbohydrate intake, mammals convert energy stored in ketone bodies to high energy phosphates. Ketone bodies provide fuel particularly to brain, heart, and skeletal muscle in states that include starvation, adherence to low carbohydrate diets, and the neonatal period. Here, we use novel Oxct1−/− mice, which lack the ketolytic enzyme succinyl-CoA:3-oxo-acid CoA-transferase (SCOT), to demonstrate that ketone body oxidation is required for postnatal survival in mice. Although Oxct1−/− mice exhibit normal prenatal development, all develop ketoacidosis, hypoglycemia, and reduced plasma lactate concentrations within the first 48 h of birth. In vivo oxidation of 13C-labeled β-hydroxybutyrate in neonatal Oxct1−/− mice, measured using NMR, reveals intact oxidation to acetoacetate but no contribution of ketone bodies to the tricarboxylic acid cycle. Accumulation of acetoacetate yields a markedly reduced β-hydroxybutyrate:acetoacetate ratio of 1:3, compared with 3:1 in Oxct1+ littermates. Frequent exogenous glucose administration to actively suckling Oxct1−/− mice delayed, but could not prevent, lethality. Brains of newborn SCOT-deficient mice demonstrate evidence of adaptive energy acquisition, with increased phosphorylation of AMP-activated protein kinase α, increased autophagy, and 2.4-fold increased in vivo oxidative metabolism of [13C]glucose. Furthermore, [13C]lactate oxidation is increased 1.7-fold in skeletal muscle of Oxct1−/− mice but not in brain. These results indicate the critical metabolic roles of ketone bodies in neonatal metabolism and suggest that distinct tissues exhibit specific metabolic responses to loss of ketone body oxidation. PMID:21209089

  6. Catalytic Intramolecular Ketone Alkylation with Olefins by Dual Activation.

    PubMed

    Lim, Hee Nam; Dong, Guangbin

    2015-12-01

    Two complementary methods for catalytic intramolecular ketone alkylation reactions with unactivated olefins, resulting in Conia-ene-type reactions, are reported. The transformations are enabled by dual activation of both the ketone and the olefin and are atom-economical as stoichiometric oxidants or reductants are not required. Assisted by Kool's aniline catalyst, the reaction conditions can be both pH- and redox-neutral. A broad range of functional groups are thus tolerated. Whereas the rhodium catalysts are effective for the formation of five-membered rings, a ruthenium-based system that affords the six-membered ring products was also developed. PMID:26486569

  7. Formation of alcohol conversion catalysts

    DOEpatents

    Wachs, Israel E.; Cai, Yeping

    2001-01-01

    The method of the present invention involves a composition containing an intimate mixture of (a) metal oxide support particles and (b) a catalytically active metal oxide from Groups VA, VIA, or VIIA, its method of manufacture, and its method of use for converting alcohols to aldehydes. During the conversion process, catalytically active metal oxide from the discrete catalytic metal oxide particles migrates to the oxide support particles and forms a monolayer of catalytically active metal oxide on the oxide support particle to form a catalyst composition having a higher specific activity than the admixed particle composition.

  8. Electrochemical reduction of aromatic ketones in 1-butyl-3-methylimidazolium-based ionic liquids in the presence of carbon dioxide: the influence of the ketone substituent and the ionic liquid anion on bulk electrolysis product distribution.

    PubMed

    Zhao, Shu-Feng; Horne, Mike; Bond, Alan M; Zhang, Jie

    2015-07-15

    Electrochemical reduction of aromatic ketones, including acetophenone, benzophenone and 4-phenylbenzophenone, has been undertaken in 1-butyl-3-methylimidazolium-based ionic liquids containing tetrafluoroborate ([BF4](-)), trifluoromethanesulfonate ([TfO](-)) and tris(pentafluoroethyl)trifluorophosphate ([FAP](-)) anions in the presence of carbon dioxide in order to investigate the ketone substituent effect and the influence of the acidic proton on the imidazolium cation (C2-H) on bulk electrolysis product distribution. For acetophenone, the minor products were dimers (<10%) in all ionic liquids, which are the result of acetophenone radical anion coupling. For benzophenone and 4-phenylbenzophenone, no dimers were formed due to steric hindrance. In these cases, even though carboxylic acids were obtained, the main products generated were alcohols (>50%) derived from proton coupled electron transfer reactions involving the electrogenerated radical anions and C2-H. In the cases of both acetophenone and benzophenone, the product distribution is essentially independent of the ionic liquid anion. By contrast, 4-phenylbenzophenone shows a product distribution that is dependent on the ionic liquid anion. Higher yields of carboxylic acids (∼40%) are obtained with [TfO](-) and [FAP](-) anions because in these ionic liquids the C2-H is less acidic, making the formation of alcohol less favourable. In comparison with benzophenone, a higher yield of carboxylic acid (>30% versus ∼15%) was obtained with 4-phenylbenzophenone in all ionic liquids due to the weaker basicity of 4-phenylbenzophenone radical anion. PMID:26136079

  9. Reversible catalytic dehydrogenation of alcohols for energy storage

    PubMed Central

    Bonitatibus, Peter J.; Chakraborty, Sumit; Doherty, Mark D.; Siclovan, Oltea; Jones, William D.; Soloveichik, Grigorii L.

    2015-01-01

    Reversibility of a dehydrogenation/hydrogenation catalytic reaction has been an elusive target for homogeneous catalysis. In this report, reversible acceptorless dehydrogenation of secondary alcohols and diols on iron pincer complexes and reversible oxidative dehydrogenation of primary alcohols/reduction of aldehydes with separate transfer of protons and electrons on iridium complexes are shown. This reactivity suggests a strategy for the development of reversible fuel cell electrocatalysts for partial oxidation (dehydrogenation) of hydroxyl-containing fuels. PMID:25588879

  10. YNL134C from Saccharomyces cerevisiae encodes a novel protein with aldehyde reductase activity for detoxification of furfural derived from lignocellulosic biomass.

    PubMed

    Zhao, Xianxian; Tang, Juan; Wang, Xu; Yang, Ruoheng; Zhang, Xiaoping; Gu, Yunfu; Li, Xi; Ma, Menggen

    2015-05-01

    Furfural and 5-hydroxymethylfurfural (HMF) are the two main aldehyde compounds derived from pentoses and hexoses, respectively, during lignocellulosic biomass pretreatment. These two compounds inhibit microbial growth and interfere with subsequent alcohol fermentation. Saccharomyces cerevisiae has the in situ ability to detoxify furfural and HMF to the less toxic 2-furanmethanol (FM) and furan-2,5-dimethanol (FDM), respectively. Herein, we report that an uncharacterized gene, YNL134C, was highly up-regulated under furfural or HMF stress and Yap1p and Msn2/4p transcription factors likely controlled its up-regulated expression. Enzyme activity assays showed that YNL134C is an NADH-dependent aldehyde reductase, which plays a role in detoxification of furfural to FM. However, no NADH- or NADPH-dependent enzyme activity was observed for detoxification of HMF to FDM. This enzyme did not catalyse the reverse reaction of FM to furfural or FDM to HMF. Further studies showed that YNL134C is a broad-substrate aldehyde reductase, which can reduce multiple aldehydes to their corresponding alcohols. Although YNL134C is grouped into the quinone oxidoreductase family, no quinone reductase activity was observed using 1,2-naphthoquinone or 9,10-phenanthrenequinone as a substrate, and phylogenetic analysis indicates that it is genetically distant to quinone reductases. Proteins similar to YNL134C in sequence from S. cerevisiae and other microorganisms were phylogenetically analysed. PMID:25656244

  11. Silver-catalyzed synthesis of amides from amines and aldehydes

    DOEpatents

    Madix, Robert J; Zhou, Ling; Xu, Bingjun; Friend, Cynthia M; Freyschlag, Cassandra G

    2014-11-18

    The invention provides a method for producing amides via the reaction of aldehydes and amines with oxygen adsorbed on a metallic silver or silver alloy catalyst. An exemplary reaction is shown in Scheme 1: (I), (II), (III). ##STR00001##

  12. 27 CFR 24.183 - Use of distillates containing aldehydes.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... the fermentation of wine and then returned to the distilled spirits plant from which distillates were... fermentation of wine made from a different kind of fruit. Distillates containing aldehydes which are...

  13. 27 CFR 24.183 - Use of distillates containing aldehydes.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... the fermentation of wine and then returned to the distilled spirits plant from which distillates were... fermentation of wine made from a different kind of fruit. Distillates containing aldehydes which are...

  14. 27 CFR 24.183 - Use of distillates containing aldehydes.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... the fermentation of wine and then returned to the distilled spirits plant from which distillates were... fermentation of wine made from a different kind of fruit. Distillates containing aldehydes which are...

  15. 27 CFR 24.183 - Use of distillates containing aldehydes.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... the fermentation of wine and then returned to the distilled spirits plant from which distillates were... fermentation of wine made from a different kind of fruit. Distillates containing aldehydes which are...

  16. 27 CFR 24.183 - Use of distillates containing aldehydes.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... the fermentation of wine and then returned to the distilled spirits plant from which distillates were... fermentation of wine made from a different kind of fruit. Distillates containing aldehydes which are...

  17. 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

  18. A kinetic estimate of the free aldehyde content of aldoses

    NASA Technical Reports Server (NTRS)

    Dworkin, J. P.; Miller, S. L.; Bada, J. L. (Principal Investigator)

    2000-01-01

    The relative free aldehyde content of eight hexoses and four pentoses has been estimated within about 10% from the rate constants for their reaction with urazole (1,2,4-triazole-3,5-dione). These values of the percent free aldehyde are in agreement with those estimated from CD measurements, but are more accurate. The relative free aldehyde contents for the aldoses were then correlated to various literature NMR measurements to obtain the absolute values. This procedure was also done for three deoxyaldoses, which react much more rapidly than can be accounted for by the free aldehyde content. This difference in reactivity between aldoses and deoxyaldoses is due to the inductive effect of the H versus the OH on C-2'. This may help explain why deoxyribonucleosides hydrolyze much more rapidly than ribonucleosides.

  19. Human liver aldehyde dehydrogenase: coenzyme binding

    SciTech Connect

    Kosley, L.L.; Pietruszko, R.

    1987-05-01

    The binding of (U-/sup 14/C) NAD to mitochondrial (E2) and cytoplasmin(E1) aldehyde dehydrogenase was measured by gel filtration and sedimentation techniques. The binding data for NAD and (E1) yielded linear Scatchard plots giving a dissociation constant of 25 (+/- 8) uM and the stoichiometry of 2 mol of NAD bound per mol of E1. The binding data for NAD and (E2) gave nonlinear Scatchard plots. The binding of NADH to E2 was measured via fluorescence enhancement; this could not be done with E1 because there was no signal. The dissociation constant for E2 by this technique was 0.7 (+/- 0.4) uM and stoichiometry of 1.0 was obtained. The binding of (U-/sup 14/C) NADH to (E1) and (E2) was also measured by the sedimentation technique. The binding data for (E1) and NADH gave linear Scatchard plots giving a dissociation constant of 13 (+/- 6) uM and the stoichiometry of 2.0. The binding data for NADH to (E2) gave nonlinear Scatchard plots. With (E1), the dissociation constants for both NAD and NADH are similar to those determined kinetically, but the stoichiometry is only half of that found by stopped flow technique. With (E2) the dissociation constant by fluorometric procedure was 2 orders of magnitude less than that from catalytic reaction.

  20. A comparative multidimensional LC-MS proteomic analysis reveals mechanisms for furan aldehyde detoxification in Thermoanaerobacter pseudethanolicus 39E

    DOE PAGESBeta

    Clarkson, Sonya M.; Hamilton-Brehm, Scott D.; Giannone, Richard J.; Engle, Nancy L.; Tschaplinski, Timothy J.; Hettich, Robert L.; Elkins, James G.

    2014-12-03

    Background: Chemical and physical pretreatment of lignocellulosic biomass improves substrate reactivity for increased microbial biofuel production, but also restricts growth via the release of furan aldehydes such as furfural and 5-hydroxymethylfurfural (5-HMF). The physiological effects of these inhibitors on thermophilic, fermentative bacteria is important to understand; especially as cellulolytic strains are being developed for consolidated bioprocessing (CBP) of lignocellulosic feedstocks. Identifying mechanisms for detoxification of aldehydes in naturally resistant strains such as Thermoanaerobacter spp. may also enable improvements in candidate CBP microorganisms. Results: T. pseudethanolicus 39E, an anaerobic, saccharolytic thermophile, was found to grow readily in the presence of 30more » mM furfural and 20 mM 5-HMF and reduce these aldehydes to their respective alcohols in situ. The proteomes of T. pseudethanolicus 39E grown in the presence or absence of 15 mM furfural were compared to identify upregulated enzymes potentially responsible for the observed reduction. A total of 225 proteins were differentially regulated in response to the 15 mM furfural treatment with 152 upregulated vs. 73 downregulated. Only 86 proteins exhibited a 2-fold change in abundance in either direction. Of these, 53 were upregulated in the presence of furfural and 33 were downregulated. Two oxidoreductases were upregulated at least 2-fold by furfural and were targeted for further investigation: Teth39_1597, encodes a predicted butanol dehydrogenase (BdhA) and Teth39_1598, a predicted aldo/keto reductase (AKR). Both genes were cloned from T. pseudethanolicus 39E, with the respective enzymes overexpressed in E. coli and specific activities determined against a variety of aldehydes. BdhA showed significant activity with all aldehydes tested, including furfural and 5-HMF, using NADPH as the cofactor. AKR also showed significant activity with NADPH, but only with four carbon butyr

  1. Engineering Saccharomyces cerevisiae to produce odd chain-length fatty alcohols.

    PubMed

    Jin, Zhu; Wong, Adison; Foo, Jee Loon; Ng, Joey; Cao, Ying-Xiu; Chang, Matthew Wook; Yuan, Ying-Jin

    2016-04-01

    Fatty aldehydes and alcohols are valuable precursors used in the industrial manufacturing of a myriad of specialty products. Herein, we demonstrate the de novo production of odd chain-length fatty aldehydes and fatty alcohols in Saccharomyces cerevisiae by expressing a novel biosynthetic pathway involving cytosolic thioesterase, rice α-dioxygenase and endogenous aldehyde reductases. We attained production titers of ∼20 mg/l fatty aldehydes and ∼20 mg/l fatty alcohols in shake flask cultures after 48 and 60 h respectively without extensive fine-tuning of metabolic fluxes. In contrast to prior studies which relied on bi-functional fatty acyl-CoA reductase to produce even chain-length fatty alcohols, our biosynthetic route exploits α-oxidation reaction to produce odd chain-length fatty aldehyde intermediates without using NAD(P)H cofactor, thereby conserving cellular resource during the overall synthesis of odd chain-length fatty alcohols. The biosynthetic pathway presented in this study has the potential to enable sustainable and efficient synthesis of fatty acid-derived chemicals from processed biomass. PMID:26461930

  2. 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

  3. Hydroxyalkylation with. cap alpha. -hydroperoxydiazenes. Alcohols from olefins and carbonyl compounds from enol ethers

    SciTech Connect

    Osei-Twum, E.Y.; McCallion, D.; Nazran, A.S.; Panicucci, R.; Risbood, P.A.; Warkentin, J.

    1984-01-27

    Alkyl(1-hydroperoxy-1-methylethyl)diazenes 2a-C((CH/sub 3/)/sup 2/C(OOH)N=NR: a,R =CH/sub 2/CH/sub 2/CN; c,R = CH/sub 2/CH(CH/sub 3/)CN; d,R = CH/sub 2/CH/sub 2/OCH/sub 3/; e,r =CH/sub 2/CH/sub 2/OC/sub 6/H/sub 5/; f,R = CH/sub 2/CH/sub 2/CH/sub 2/OC/sub 6/H/sub 5/)) were prepared in solution by autoxidation of the corresponding hydrazones of acetone. Thermolysis of the diazenes at 50-80/sup 0/C in alkenes leads to alcohols. For example, 2b decomposes in 1,1-diphenylethene to afford 5-hydroxy-5,5-yield. Thermolysis of a diazene 2 in an enol ether solvent leads to an aldehyde or a ketone. Thus, 2a decomposes in 1-ethoxyethene and in 2-methoxypropene to afford, respective, 4,4,4-trifluorobutanol and 5,5,5-trifluoro-intermediates and radical chain hydroxyalkylation of alkene double bonds. In one chain-propagating step, R., generated from 2, adds to the alkene. The adduct radical so formed propagates by inducing decomposition of 2 by attack at hydroxyl oxygen. According to this mechanism, inital products from enol ethers are hemiacetals or hemiketals which do not survive the reaction conditions but decompose to the corresponding carbonyl compounds. Preliminary evidence for this mechanism is presented.

  4. Utility of ketone measurement in the prevention, diagnosis and management of diabetic ketoacidosis.

    PubMed

    Misra, S; Oliver, N S

    2015-01-01

    Ketone measurement is advocated for the diagnosis of diabetic ketoacidosis and assessment of its severity. Assessing the evidence base for ketone measurement in clinical practice is challenging because multiple methods are available but there is a lack of consensus about which is preferable. Evaluating the utility of ketone measurement is additionally problematic because of variability in the biochemical definition of ketoacidosis internationally and in the proposed thresholds for ketone measures. This has led to conflicting guidance from expert bodies on how ketone measurement should be used in the management of ketoacidosis. The development of point-of-care devices that can reliably measure the capillary blood ketone β-hydroxybutyrate (BOHB) has widened the spectrum of applications of ketone measurement, but whether the evidence base supporting these applications is robust enough to warrant their incorporation into routine clinical practice remains unclear. The imprecision of capillary blood ketone measures at higher values, the lack of availability of routine laboratory-based assays for BOHB and the continued cost-effectiveness of urine ketone assessment prompt further discussion on the role of capillary blood ketone assessment in ketoacidosis. In the present article, we review the various existing methods of ketone measurement, the precision of capillary blood ketone as compared with other measures, its diagnostic accuracy in predicting ketoacidosis and other clinical applications including prevention, assessment of severity and resolution of ketoacidosis. PMID:25307274

  5. Crystal morphology and phase identifications in poly(aryl ether ketones)s and their copolymers

    SciTech Connect

    Ho, R.M.; Cheng, S.Z.D.; Hsiao, B.S.

    1995-12-01

    A series of poly(aryl ether ketone ketone)s prepared from diphenyl ether (DPE) and terephthalic acid M or isophthalic acid (T) have been investigated. PEKK(T) has been reported to exhibit two polymorphism (form I and form II) based on wide angle X-ray diffraction (WAXD) and electron diffraction (ED) experiments.

  6. 21 CFR 862.1435 - Ketones (nonquantitative) test system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ketones (nonquantitative) test system. 862.1435 Section 862.1435 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry...

  7. Ketonization of Cuphea oil for the production of 2-undecanone

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this work was to demonstrate the viability of the cross ketonization reaction with the triacylglycerol from Cuphea sp. and acetic acid in a fixed-bed plug-flow reactor. The seed oil from Cuphea sp. contains up to 71% decanoic acid and the reaction of this fatty acid residue with ac...

  8. Ketone body therapy: from the ketogenic diet to the oral administration of ketone ester

    PubMed Central

    Hashim, Sami A.; VanItallie, Theodore B.

    2014-01-01

    Ketone bodies (KBs), acetoacetate and β-hydroxybutyrate (βHB), were considered harmful metabolic by-products when discovered in the mid-19th century in the urine of patients with diabetic ketoacidosis. It took physicians many years to realize that KBs are normal metabolites synthesized by the liver and exported into the systemic circulation to serve as an energy source for most extrahepatic tissues. Studies have shown that the brain (which normally uses glucose for energy) can readily utilize KBs as an alternative fuel. Even when there is diminished glucose utilization in cognition-critical brain areas, as may occur early in Alzheimer’s disease (AD), there is preliminary evidence that these same areas remain capable of metabolizing KBs. Because the ketogenic diet (KD) is difficult to prepare and follow, and effectiveness of KB treatment in certain patients may be enhanced by raising plasma KB levels to ≥2 mM, KB esters, such as 1,3-butanediol monoester of βHB and glyceryl-tris-3-hydroxybutyrate, have been devised. When administered orally in controlled dosages, these esters can produce plasma KB levels comparable to those achieved by the most rigorous KD, thus providing a safe, convenient, and versatile new approach to the study and potential treatment of a variety of diseases, including epilepsy, AD, and Parkinson’s disease. PMID:24598140

  9. Ketone body therapy: from the ketogenic diet to the oral administration of ketone ester.

    PubMed

    Hashim, Sami A; VanItallie, Theodore B

    2014-09-01

    Ketone bodies (KBs), acetoacetate and β-hydroxybutyrate (βHB), were considered harmful metabolic by-products when discovered in the mid-19th century in the urine of patients with diabetic ketoacidosis. It took physicians many years to realize that KBs are normal metabolites synthesized by the liver and exported into the systemic circulation to serve as an energy source for most extrahepatic tissues. Studies have shown that the brain (which normally uses glucose for energy) can readily utilize KBs as an alternative fuel. Even when there is diminished glucose utilization in cognition-critical brain areas, as may occur early in Alzheimer's disease (AD), there is preliminary evidence that these same areas remain capable of metabolizing KBs. Because the ketogenic diet (KD) is difficult to prepare and follow, and effectiveness of KB treatment in certain patients may be enhanced by raising plasma KB levels to ≥2 mM, KB esters, such as 1,3-butanediol monoester of βHB and glyceryl-tris-3-hydroxybutyrate, have been devised. When administered orally in controlled dosages, these esters can produce plasma KB levels comparable to those achieved by the most rigorous KD, thus providing a safe, convenient, and versatile new approach to the study and potential treatment of a variety of diseases, including epilepsy, AD, and Parkinson's disease. PMID:24598140

  10. 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

  11. Alcoholism and Alcohol Abuse

    MedlinePlus

    ... increase the risk of certain cancers. It can cause damage to the liver, brain, and other organs. Drinking during pregnancy can harm your baby. Alcohol also increases the risk of death from car crashes, injuries, homicide, and suicide. If you want to stop drinking, there is ...

  12. Aldehydes with high and low toxicities inactivate cells by damaging distinct cellular targets.

    PubMed

    Xie, Ming-Zhang; Shoulkamy, Mahmoud I; Salem, Amir M H; Oba, Shunya; Goda, Mizuki; Nakano, Toshiaki; Ide, Hiroshi

    2016-04-01

    Aldehydes are genotoxic and cytotoxic molecules and have received considerable attention for their associations with the pathogenesis of various human diseases. In addition, exposure to anthropogenic aldehydes increases human health risks. The general mechanism of aldehyde toxicity involves adduct formation with biomolecules such as DNA and proteins. Although the genotoxic effects of aldehydes such as mutations and chromosomal aberrations are directly related to DNA damage, the role of DNA damage in the cytotoxic effects of aldehydes is poorly understood because concurrent protein damage by aldehydes has similar effects. In this study, we have analysed how saturated and α,β-unsaturated aldehydes exert cytotoxic effects through DNA and protein damage. Interestingly, DNA repair is essential for alleviating the cytotoxic effect of weakly toxic aldehydes such as saturated aldehydes but not highly toxic aldehydes such as long α,β-unsaturated aldehydes. Thus, highly toxic aldehydes inactivate cells exclusively by protein damage. Our data suggest that DNA interstrand crosslinks, but not DNA-protein crosslinks and DNA double-strand breaks, are the critical cytotoxic DNA damage induced by aldehydes. Further, we show that the depletion of intracellular glutathione and the oxidation of thioredoxin 1 partially account for the DNA damage-independent cytotoxicity of aldehydes. On the basis of these findings, we have proposed a mechanistic model of aldehyde cytotoxicity mediated by DNA and protein damage. PMID:26917342

  13. Copper(I)-catalyzed enantioselective nucleophilic borylation of aldehydes: an efficient route to enantiomerically enriched α-alkoxyorganoboronate esters.

    PubMed

    Kubota, Koji; Yamamoto, Eiji; Ito, Hajime

    2015-01-14

    The first catalytic enantioselective nucleophilic borylation of a C═O double bond has been achieved. A series of aldehydes reacted with a diboron reagent in the presence of a copper(I)/DTBM-SEGPHOS complex catalyst using MeOH as a proton source to give the corresponding optically active α-alkoxyorganoboronate esters with excellent enantioselectivities. Furthermore, the products could be readily converted to the corresponding functionalized chiral alcohol derivatives through stereospecific C-C bond forming reactions involving the stereogenic C-B bond. PMID:25494834

  14. Recent developments in alcoholism:genetic transmission.

    PubMed

    Goldman, D

    1993-01-01

    approach for detecting genes influencing behavior. The relationship of the alcohol metabolic gene variants to alcoholism was clarified by the finding that functional variants of alcohol and aldehyde dehydrogenases can act additively to determine vulnerability to alcoholism. PMID:8234925

  15. Aldehyde Dehydrogenase Inhibitors: a Comprehensive Review of the Pharmacology, Mechanism of Action, Substrate Specificity, and Clinical Application

    PubMed Central

    Koppaka, Vindhya; Thompson, David C.; Chen, Ying; Ellermann, Manuel; Nicolaou, Kyriacos C.; Juvonen, Risto O.; Petersen, Dennis; Deitrich, Richard A.; Hurley, Thomas D.

    2012-01-01

    Aldehyde dehydrogenases (ALDHs) belong to a superfamily of enzymes that play a key role in the metabolism of aldehydes of both endogenous and exogenous derivation. The human ALDH superfamily comprises 19 isozymes that possess important physiological and toxicological functions. The ALDH1A subfamily plays a pivotal role in embryogenesis and development by mediating retinoic acid signaling. ALDH2, as a key enzyme that oxidizes acetaldehyde, is crucial for alcohol metabolism. ALDH1A1 and ALDH3A1 are lens and corneal crystallins, which are essential elements of the cellular defense mechanism against ultraviolet radiation-induced damage in ocular tissues. Many ALDH isozymes are important in oxidizing reactive aldehydes derived from lipid peroxidation and thereby help maintain cellular homeostasis. Increased expression and activity of ALDH isozymes have been reported in various human cancers and are associated with cancer relapse. As a direct consequence of their significant physiological and toxicological roles, inhibitors of the ALDH enzymes have been developed to treat human diseases. This review summarizes known ALDH inhibitors, their mechanisms of action, isozyme selectivity, potency, and clinical uses. The purpose of this review is to 1) establish the current status of pharmacological inhibition of the ALDHs, 2) provide a rationale for the continued development of ALDH isozyme-selective inhibitors, and 3) identify the challenges and potential therapeutic rewards associated with the creation of such agents. PMID:22544865

  16. Alcohol Calorie Calculator

    MedlinePlus

    ... Alcohol Calorie Calculator Weekly Total 0 Calories Alcohol Calorie Calculator Find out the number of beer and ... Calories College Alcohol Policies Interactive Body Calculators Alcohol Calorie Calculator Alcohol Cost Calculator Alcohol BAC Calculator Alcohol ...

  17. PHOTOCATALYTIC REACTORS AND KINETICS FOR CLEAN CHEMICAL SYNTHESIS [POSTER PRESENTATION

    EPA Science Inventory

    Semiconductor photocatalysis has been tested at a potential technology for synthesizing alcohols, ketones and aldehydes from linear and cyclic hydrocarbons. The technology couples UV light with photocatalyst overcoming many of the drawbacks of conventional reacors. Various hydr...

  18. Application of Novel Method to Measure Endogenous VOCs in Exhaled Breath Condensate Before and After Exposure to Diesel Exhaust

    EPA Science Inventory

    Polar volatile organic compounds (PVOCs) such as aldehydes, ketones, and alcohols are byproducts of normal human metabolism and are present in exhaled breath and blood. Environmental exposures, individual activities, and disease states can perturb normal metabolic processes and ...

  19. Hydride transfer made easy in the oxidation of alcohols catalyzed by choline oxidase

    SciTech Connect

    Gadda, G.; Orville, A.; Pennati, A.; Francis, K.; Quaye, O.; Yuan, H.; Rungsrisuriyachai, K.; Finnegan, S.; Mijatovic, S.; Nguyen, T.

    2008-06-08

    Choline oxidase (E.C. 1.1.3.17) catalyzes the two-step, four-electron oxidation of choline to glycine betaine with betaine aldehyde as enzyme-associated intermediate and molecular oxygen as final electron acceptor (Scheme 1). The gem-diol, hydrated species of the aldehyde intermediate of the reaction acts as substrate for aldehyde oxidation, suggesting that the enzyme may use similar strategies for the oxidation of the alcohol substrate and aldehyde intermediate. The determination of the chemical mechanism for alcohol oxidation has emerged from biochemical, mechanistic, mutagenetic, and structural studies. As illustrated in the mechanism of Scheme 2, the alcohol substrate is initially activated in the active site of the enzyme by removal of the hydroxyl proton. The resulting alkoxide intermediate is then stabilized in the enzyme-substrate complex via electrostatic interactions with active site amino acid residues. Alcohol oxidation then occurs quantum mechanically via the transfer of the hydride ion from the activated substrate to the N(5) flavin locus. An essential requisite for this mechanism of alcohol oxidation is the high degree of preorganization of the activated enzyme-substrate complex, which is achieved through an internal equilibrium of the Michaelis complex occurring prior to, and independently from, the subsequent hydride transfer reaction. The experimental evidence that support the mechanism for alcohol oxidation shown in Scheme 2 is briefly summarized in the Results and Discussion section.

  20. Novel sulfonated poly(ether ether ketone ketone)s for direct methanol fuel cells usage: Synthesis, water uptake, methanol diffusion coefficient and proton conductivity

    NASA Astrophysics Data System (ADS)

    Zhang, Gang; Fu, Tiezhu; Shao, Ke; Li, Xianfeng; Zhao, Chengji; Na, Hui; Zhang, Hong

    A novel series of sulfonated poly(ether ether ketone ketone)s (SPEEKKs) with different degrees of sulfonation (Ds) were synthesized from 1,3-bis(3-sodium sulfonate-4-fluorobenzoyl)benzene (1,3-SFBB-Na), 1,3-bis(4-fluorobenzoyl)benzene (1,3-FBB) and 3,3‧,5,5‧-tetramethyl-4,4‧-biphenol (TMBP) by aromatic nucleophilic polycondensation. The chemical structures of SPEEKKs were confirmed by FT-IR spectroscopy and the Ds values of the polymers were calculated by 1H NMR and titration methods, respectively. The thermal stabilities of the SPEEKKs in acid and sodium forms were characterized by thermogravimetric analysis (TGA), which showed that SPEEKKs had excellent thermal properties at high temperatures. All the SPEEKK polymers were easily solution cast into tough membranes. Water uptakes, proton conductivities and methanol diffusion coefficients of the SPEEKK membranes were measured. Water uptake increased with Ds and temperature. Compared to Nafion, the SPEEKK-60, -70 and -80 membranes showed higher proton conductivities at 80 °C, while the other SPEEKK membranes showed relatively lower proton conductivities. This may be due to the different distribution of ion-conducting domains in membrane. However, these membranes showed lower methanol diffusions in the range of 8.32 × 10 -9 to 1.14 × 10 -7 cm 2 s -1 compared with that of Nafion (2 × 10 -6 cm 2 s -1) at the same temperature. The membranes also showed excellent mechanical properties (with a Young's modulus > 1 GPa and a tensile strength > 40 MPa). These results indicate that the SPEEKK membranes are promising materials for use in direct methanol fuel cell (DMFC) applications.

  1. Reaction of tobacco smoke aldehydes with human hemoglobin.

    PubMed

    Hoberman, H D; San George, R C

    1988-01-01

    Formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, isobutyraldehyde, and acrolein, all of which are constituents of tobacco smoke, were reacted in 5 mM concentration with the purified major fraction of normal adult human hemoglobin (hemoglobin Ao) in 1 mM concentration. A cigarette smoke condensate, diluted to contain 5 mM total aldehydes, was also reacted with 1 mM hemoglobin Ao. Cationic exchange high-performance liquid chromatography (HPLC) showed that the products formed from simple aliphatic aldehydes, with the exception of formaldehyde, were analogues of those formed from acetaldehyde, earlier shown by us to be imidazolidinone derivatives, that is, cyclic addition products of the N-terminal aminoamide function of alpha and beta chains. Formaldehyde and acrolein produced a heterogeneous mixture of derivatives including cross-linked hemoglobin dimers. The greater proportion of modified hemoglobins produced by condensate aldehydes resembled those formed from acetaldehyde, the most abundant aldehyde in the condensate. A smaller fraction consisted of cross-linked hemoglobin dimers, presumably due to the action of formaldehyde. Mass spectrometric and HPLC analyses of the 2,4-dinitrophenylhydrazones precipitated from the condensate documented the presence of formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, furfural, and methylfurfural. The toxicity of aldehydes is briefly discussed in the context of the findings of this study. PMID:3236330

  2. 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

  3. Highly selective anti-Prelog synthesis of optically active aryl alcohols by recombinant Escherichia coli expressing stereospecific alcohol dehydrogenase.

    PubMed

    Li, Ming; Nie, Yao; Mu, Xiao Qing; Zhang, Rongzhen; Xu, Yan

    2016-07-01

    Biocatalytic asymmetric synthesis has been widely used for preparation of optically active chiral alcohols as the important intermediates and precursors of active pharmaceutical ingredients. However, the available whole-cell system involving anti-Prelog specific alcohol dehydrogenase is yet limited. A recombinant Escherichia coli system expressing anti-Prelog stereospecific alcohol dehydrogenase from Candida parapsilosis was established as a whole-cell system for catalyzing asymmetric reduction of aryl ketones to anti-Prelog configured alcohols. Using 2-hydroxyacetophenone as the substrate, reaction factors including pH, cell status, and substrate concentration had obvious impacts on the outcome of whole-cell biocatalysis, and xylose was found to be an available auxiliary substrate for intracellular cofactor regeneration, by which (S)-1-phenyl-1,2-ethanediol was achieved with an optical purity of 97%e.e. and yield of 89% under the substrate concentration of 5 g/L. Additionally, the feasibility of the recombinant cells toward different aryl ketones was investigated, and most of the corresponding chiral alcohol products were obtained with an optical purity over 95%e.e. Therefore, the whole-cell system involving recombinant stereospecific alcohol dehydrogenase was constructed as an efficient biocatalyst for highly enantioselective anti-Prelog synthesis of optically active aryl alcohols and would be promising in the pharmaceutical industry. PMID:26178068

  4. Functionalization of poly(aryl ether ether ketone)

    SciTech Connect

    Wang, Fei; Roovers, J.

    1993-12-31

    Bromomethyl and dibromomethyl substituted poly(aryl ether ether ketone) have been prepared from methyl poly(aryl ether ether ketone) by bromination with bromine. These brominated polymers are intermediates that can be further functionalized by: hydrolysis, oxidation, substitution etc. A series of new functionalized PEEK polymers has been prepared. The functional group includes -CH{sub 2}OH, -CH{sub 2}OCH{sub 3}, -CHO, -COOH, -COOCH{sub 3}, -CH{sub 2}CN, -CH{sub 2}COOH, -CH{sub 2}OCOCH{sub 3}, -CH{sub 2}N{sup +}H(CH{sub 2}CH{sub 3}){sub 2}Br{sup {minus}}, -CH{sub 2}N(CH{sub 2}CH{sub 3}){sub 2}, -CH{sub 2}N{sup +}H(CH{sub 2}CH{sub 3}){sub 3}Br{sup {minus}}.

  5. Propyl alcohol

    MedlinePlus

    Rubbing alcohol Alcohol swabs Skin and hair products Nail polish remover Note: This list may not be all ... number will let you talk to experts in poisoning. They will give you further instructions. This is ...

  6. Metabolic reprogramming induced by ketone bodies diminishes pancreatic cancer cachexia

    PubMed Central

    2014-01-01

    Background Aberrant energy metabolism is a hallmark of cancer. To fulfill the increased energy requirements, tumor cells secrete cytokines/factors inducing muscle and fat degradation in cancer patients, a condition known as cancer cachexia. It accounts for nearly 20% of all cancer-related deaths. However, the mechanistic basis of cancer cachexia and therapies targeting cancer cachexia thus far remain elusive. A ketogenic diet, a high-fat and low-carbohydrate diet that elevates circulating levels of ketone bodies (i.e., acetoacetate, β-hydroxybutyrate, and acetone), serves as an alternative energy source. It has also been proposed that a ketogenic diet leads to systemic metabolic changes. Keeping in view the significant role of metabolic alterations in cancer, we hypothesized that a ketogenic diet may diminish glycolytic flux in tumor cells to alleviate cachexia syndrome and, hence, may provide an efficient therapeutic strategy. Results We observed reduced glycolytic flux in tumor cells upon treatment with ketone bodies. Ketone bodies also diminished glutamine uptake, overall ATP content, and survival in multiple pancreatic cancer cell lines, while inducing apoptosis. A decrease in levels of c-Myc, a metabolic master regulator, and its recruitment on glycolytic gene promoters, was in part responsible for the metabolic phenotype in tumor cells. Ketone body-induced intracellular metabolomic reprogramming in pancreatic cancer cells also leads to a significantly diminished cachexia in cell line models. Our mouse orthotopic xenograft models further confirmed the effect of a ketogenic diet in diminishing tumor growth and cachexia. Conclusions Thus, our studies demonstrate that the cachectic phenotype is in part due to metabolic alterations in tumor cells, which can be reverted by a ketogenic diet, causing reduced tumor growth and inhibition of muscle and body weight loss. PMID:25228990

  7. A constitutive model of polyether-ether-ketone (PEEK).

    PubMed

    Chen, Fei; Ou, Hengan; Lu, Bin; Long, Hui

    2016-01-01

    A modified Johnson-Cook (JC) model was proposed to describe the flow behaviour of polyether-ether-ketone (PEEK) with the consideration of coupled effects of strain, strain rate and temperature. As compared to traditional JC model, the modified one has better ability to predict the flow behaviour at elevated temperature conditions. In particular, the yield stress was found to be inversely proportional to temperature from the predictions of the proposed model. PMID:26409233

  8. Catalytic Leuckart-Wallach-type reductive amination of ketones.

    PubMed

    Kitamura, Masato; Lee, Donghyun; Hayashi, Shinnosuke; Tanaka, Shinji; Yoshimura, Masahiro

    2002-11-29

    A CpRh(III) complex catalyzes reductive amination of ketones using HCOONH(4) at 50-70 degrees C to give the corresponding primary amines in high yields. The reaction is clean and operationally simple and proceeds at a lower temperature and with higher chemoselectivity than the original Leuckart-Wallach reaction. The new method has been applied to the synthesis of alpha-amino acids directly from alpha-keto acids. PMID:12444661

  9. Trifluoromethyl ketones as inhibitors of the processionary moth sex pheromone.

    PubMed

    Parrilla, A; Guerrero, A

    1994-02-01

    Aliphatic and aromatic trifluoromethyl ketones have been evaluated in the laboratory and in the field as inhibitors of the pheromone response of the processionary moth Thaumetopoea pityocampa males. Among them, two compounds, (Z)-1,1,1-trifluoro-15-octadecen-13-yn-2-one and (Z)-1,1,1-trifluoro-16-nonadecen-14-yn-2-one, are closely related analogs of the natural pheromone (Z)-13-hexadecen-11-ynyl acetate. In the laboratory experiments, carried out by pre-exposure of males to vapors of the chemicals, alpha-naphthyl trifluoromethyl ketone, beta-naphthyl trifluoromethyl ketone, 1,1,1-trifluorotetradecan-2-one and (Z)-16-nonadecen-14-yn-2-one displayed notable blockage of the pheromone detection on EAG. The activity of 1,1,1-trifluorotetradecan-2-one is postulated to be due to the inhibition of the pheromone-degrading esterase. In general, the compounds have shown low specificity for the substrate and exhibited only a modest or null EAG intrinsic activity. In the field, benzyl trifluoromethyl ketone, trifluoroacetophenone, (Z)-1,1,1-trifluoro-15-octadecen-13-yn-2-one, (Z)-1,1,1-trifluoro-16-nonadecen-14-yn-2-one and beta-naphthyl trifluoroacetate showed a remarkable disruptant effect when mixed with the pheromone in 1:0.1, 1:1 and 1:10 ratio. (Z)-16-Nonadecen-14-yn-2-one has been found to be a modest agonist of the natural pheromone, exhibiting an attractant activity threefold lower than the parent molecule. PMID:8055254

  10. Mechanistic Insight into Ketone α-Alkylation with Unactivated Olefins via C-H Activation Promoted by Metal-Organic Cooperative Catalysis (MOCC): Enriching the MOCC Chemistry.

    PubMed

    Dang, Yanfeng; Qu, Shuanglin; Tao, Yuan; Deng, Xi; Wang, Zhi-Xiang

    2015-05-20

    Metal-organic cooperative catalysis (MOCC) has been successfully applied for hydroacylation of olefins with aldehydes via directed C(sp(2))-H functionalization. Most recently, it was reported that an elaborated MOCC system, containing Rh(I) catalyst and 7-azaindoline (L1) cocatalyst, could even catalyze ketone α-alkylation with unactivated olefins via C(sp(3))-H activation. Herein we present a density functional theory study to understand the mechanism of the challenging ketone α-alkylation. The transformation uses IMesRh(I)Cl(L1)(CH2═CH2) as an active catalyst and proceeds via sequential seven steps, including ketone condensation with L1, giving enamine 1b; 1b coordination to Rh(I) active catalyst, generating Rh(I)-1b intermediate; C(sp(2))-H oxidative addition, leading to a Rh(III)-H hydride; olefin migratory insertion into Rh(III)-H bond; reductive elimination, generating Rh(I)-1c(alkylated 1b) intermediate; decoordination of 1c, liberating 1c and regenerating Rh(I) active catalyst; and hydrolysis of 1c, furnishing the final α-alkylation product 1d and regenerating L1. Among the seven steps, reductive elimination is the rate-determining step. The C-H bond preactivation via agostic interaction is crucial for the bond activation. The mechanism rationalizes the experimental puzzles: why only L1 among several candidates performed perfectly, whereas others failed, and why Wilkinson's catalyst commonly used in MOCC systems performed poorly. Based on the established mechanism and stimulated by other relevant experimental reactions, we attempted to enrich MOCC chemistry computationally, exemplifying how to develop new organic catalysts and proposing L7 to be an alternative for L1 and demonstrating the great potential of expanding the hitherto exclusive use of Rh(I)/Rh(III) manifold to Co(0)/Co(II) redox cycling in developing MOCC systems. PMID:25915086

  11. Alcoholic hallucinosis.

    PubMed

    Bhat, Pookala S; Ryali, Vssr; Srivastava, Kalpana; Kumar, Shashi R; Prakash, Jyoti; Singal, Ankit

    2012-07-01

    Alcoholic hallucinosis is a rare complication of chronic alcohol abuse characterized by predominantly auditory hallucinations that occur either during or after a period of heavy alcohol consumption. Bleuler (1916) termed the condition as alcohol hallucinosis and differentiated it from Delirium Tremens. Usually it presents with acoustic verbal hallucinations, delusions and mood disturbances arising in clear consciousness and sometimes may progress to a chronic form mimicking schizophrenia. One such case with multimodal hallucinations in a Defence Service Corps soldier is presented here. PMID:24250051

  12. Solvation of Esters and Ketones in Supercritical CO2.

    PubMed

    Kajiya, Daisuke; Imanishi, Masayoshi; Saitow, Ken-ichi

    2016-02-01

    Vibrational Raman spectra for the C═O stretching modes of three esters with different functional groups (methyl, a single phenyl, and two phenyl groups) were measured in supercritical carbon dioxide (scCO2). The results were compared with Raman spectra for three ketones involving the same functional groups, measured at the same thermodynamic states in scCO2. The peak frequencies of the Raman spectra of these six solute molecules were analyzed by decomposition into the attractive and repulsive energy components, based on the perturbed hard-sphere theory. For all solute molecules, the attractive energy is greater than the repulsive energy. In particular, a significant difference in the attractive energies of the ester-CO2 and ketone-CO2 systems was observed when the methyl group is attached to the ester or ketone. This difference was significantly reduced in the solute systems with a single phenyl group and was completely absent in those with two phenyl groups. The optimized structures among the solutes and CO2 molecules based on quantum chemical calculations indicate that greater attractive energy is obtained for a system where the oxygen atom of the ester is solvated by CO2 molecules. PMID:26741296

  13. Aldehyde dehydrogenase (ALDH) in Alzheimer's and Parkinson's disease.

    PubMed

    Grünblatt, Edna; Riederer, Peter

    2016-02-01

    Evidence suggests that aldehyde dehydrogenase (ALDH; E.C. 1.2.1.3) gene, protein expression and activity are substantially decreased in the substantia nigra of patients with Parkinson's disease (PD). This holds especially true for cytosolic ALDH1A1, while mitochondrial ALDH2 is increased in the putamen of PD. Similarly, in Alzheimer's disease (AD) several studies in genetic, transcriptomic, protein and animal models suggest ALDH involvement in the neurodegeneration processes. Such data are in line with findings of increased toxic aldehydes, like for example malondialdehyde, nonenal, 3,4-dihydroxyphenylacetaldehyde and others. Genetic, transcriptomic and protein alterations may contribute to such data. Also in vitro and in vivo experimental work points to an important role of ALDH in the pathology of neurodegenerative disorders. Aims at investigating dysfunctions of aldehyde detoxification are suitable to define genetic/molecular targets for new therapeutic strategies balancing amine metabolism in devastating disorders like PD and probably also AD. PMID:25298080

  14. Alcohol Abuse

    ERIC Educational Resources Information Center

    O'Farrell, Timothy J.; Fals-Stewart, William

    2003-01-01

    We received 38 controlled studies of marital and family therapy (MFT) in alcoholism treatment. We conclude that, when the alcoholic is unwilling to seek help, MFT is effective in helping the family cope better and motivating alcoholics to enter treatment. Specifically, (a) Al-Anon facilitation and referral help family members cope better; (b)…

  15. 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

  16. Direct β-Alkylation of Aldehydes via Photoredox Organocatalysis

    PubMed Central

    2015-01-01

    Direct β-alkylation of saturated aldehydes has been accomplished by synergistically combining photoredox catalysis and organocatalysis. Photon-induced enamine oxidation provides an activated β-enaminyl radical intermediate, which readily combines with a wide range of Michael acceptors to produce β-alkyl aldehydes in a highly efficient manner. Furthermore, this redox-neutral, atom-economical C–H functionalization protocol can be achieved both inter- and intramolecularly. Mechanistic studies by various spectroscopic methods suggest that a reductive quenching pathway is operable. PMID:24754456

  17. Fluorine bearing sydnones with styryl ketone group: synthesis and their possible analgesic and anti-inflammatory activities.

    PubMed

    Deshpande, Shreenivas Ramachandrarao; Pai, Karkala Vasantakumar

    2012-04-01

    In continuation of structure activity relationship studies, a panel of fluorine containing sydnones with styryl ketone group 4-[1-oxo-3-(substituted aryl)-2-propenyl]-3-(3-chloro-4-fluorophenyl)sydnones 2a-i, was synthesized as better analgesic and anti-inflammatory agents. The title compounds were formed by condensing 4-acetyl-3-(3-chloro-4-fluorophenyl)sydnone with various substituted aryl aldehydes, characterized by spectral studies and evaluated at 100 mg\\kg b.w., p.o. for analgesic, anti-inflammatory and ulcerogenic activities. Compounds 2c and 2e showed good analgesic effect in acetic acid-induced writhing while none showed significant activity in hot plate assay in mice. In carrageenan-induced rat paw oedema test, compound 2c and 2f exhibited good anti-inflammatory effect at 3rd h, whereas compounds 2c, 2e, 2d, 2g and 2h showed activity in croton oil induced ear oedema assay in mice. Compounds 2c and 2e were less ulcerogenic than ibuprofen in rats, when tested by ulcer index method. Compounds with electron attracting substituents such as 2c and 2e were found to be promising in terms of the ratio of efficacy and adverse effect. These compounds generally exhibited better activity than those of earlier series signifying fluorine substitution. PMID:21657951

  18. Glu504Lys Single Nucleotide Polymorphism of Aldehyde Dehydrogenase 2 Gene and the Risk of Human Diseases

    PubMed Central

    Zhao, Yan; Wang, Chuancai

    2015-01-01

    Aldehyde dehydrogenase (ALDH) 2 is a mitochondrial enzyme that is known for its important role in oxidation and detoxification of ethanol metabolite acetaldehyde. ALDH2 also metabolizes other reactive aldehydes such as 4-hydroxy-2-nonenal and acrolein. The Glu504Lys single nucleotide polymorphism (SNP) of ALDH2 gene, which is found in approximately 40% of the East Asian populations, causes defect in the enzyme activity of ALDH2, leading to alterations in acetaldehyde metabolism and alcohol-induced “flushing” syndrome. Evidence suggests that ALDH2 Glu504Lys SNP is a potential candidate genetic risk factor for a variety of chronic diseases such as cardiovascular disease, cancer, and late-onset Alzheimer's disease. In addition, the association between ALDH2 Glu504Lys SNP and the development of these chronic diseases appears to be affected by the interaction between the SNP and lifestyle factors such as alcohol consumption as well as by the presence of other genetic variations. PMID:26491656

  19. Facts about Alcohol and Alcoholism.

    ERIC Educational Resources Information Center

    Hall, Leonard C.

    Recognition of alcoholism as a treatable illness is a result of public education based on scientific facts. This publication, a digest of a more detailed survey of research about drinking and alcoholism, presents information about alcohol and its effects on individuals and society. It provides facts about the short-term and long-term effects of…

  20. Binuclear ruthenium(III) bis(thiosemicarbazone) complexes: synthesis, spectral, electrochemical studies and catalytic oxidation of alcohol.

    PubMed

    Mohamed Subarkhan, M; Ramesh, R

    2015-03-01

    A new series of binuclear ruthenium(III) thiosemicarbazone complexes of general formula [(EPh3)2(X)2Ru-L-Ru(X)2(EPh3)2] (where E=P or As; X=Cl or Br; L=NS chelating bis(thiosemicarbazone ligands) has been synthesized and characterized by analytical and spectral (FT-IR, UV-Vis and EPR). IR spectra show that the thiosemicarbazones behave as monoanionic bidentate ligands coordinating through the azomethine nitrogen and thiolate sulphur. The electronic spectra of the complexes indicate that the presence of d-d and intense LMCT transitions in the visible region. The complexes are paramagnetic (low spin d(5)) in nature and all the complexes show rhombic distortion around the ruthenium ion with three different 'g' values (gx≠gy≠gz) at 77K. All the complexes are redox active and exhibit an irreversible metal centered redox processes (Ru(III)-Ru(III)/Ru(IV)-Ru(IV); Ru(III)-Ru(III)/Ru(II)-Ru(II)) within the potential range of 0.38-0.86V and -0.39 to -0.66 V respectively, versus Ag/AgCl. Further, the catalytic efficiency of one of the complexes [Ru2Cl2(AsPh3)4(L1)] (4) has been investigated in the case of oxidation of primary and secondary alcohols into their corresponding aldehydes and ketones in the presence of N-methylmorpholine-N-oxide(NMO) as co-oxidant. The formation of high valent Ru(V)O species is proposed as catalytic intermediate for the catalytic cycle. PMID:25498823

  1. Binuclear ruthenium(III) bis(thiosemicarbazone) complexes: Synthesis, spectral, electrochemical studies and catalytic oxidation of alcohol

    NASA Astrophysics Data System (ADS)

    Mohamed Subarkhan, M.; Ramesh, R.

    2015-03-01

    A new series of binuclear ruthenium(III) thiosemicarbazone complexes of general formula [(EPh3)2(X)2Ru-L-Ru(X)2(EPh3)2] (where E = P or As; X = Cl or Br; L = NS chelating bis(thiosemicarbazone ligands) has been synthesized and characterized by analytical and spectral (FT-IR, UV-Vis and EPR). IR spectra show that the thiosemicarbazones behave as monoanionic bidentate ligands coordinating through the azomethine nitrogen and thiolate sulphur. The electronic spectra of the complexes indicate that the presence of d-d and intense LMCT transitions in the visible region. The complexes are paramagnetic (low spin d5) in nature and all the complexes show rhombic distortion around the ruthenium ion with three different 'g' values (gx ≠ gy ≠ gz) at 77 K. All the complexes are redox active and exhibit an irreversible metal centered redox processes (RuIII-RuIII/RuIV-RuIV; RuIII-RuIII/RuII-RuII) within the potential range of 0.38-0.86 V and -0.39 to -0.66 V respectively, versus Ag/AgCl. Further, the catalytic efficiency of one of the complexes [Ru2Cl2(AsPh3)4(L1)] (4) has been investigated in the case of oxidation of primary and secondary alcohols into their corresponding aldehydes and ketones in the presence of N-methylmorpholine-N-oxide(NMO) as co-oxidant. The formation of high valent RuVdbnd O species is proposed as catalytic intermediate for the catalytic cycle.

  2. Alcoholic cardiomyopathy

    PubMed Central

    Guzzo-Merello, Gonzalo; Cobo-Marcos, Marta; Gallego-Delgado, Maria; Garcia-Pavia, Pablo

    2014-01-01

    Alcohol is the most frequently consumed toxic substance in the world. Low to moderate daily intake of alcohol has been shown to have beneficial effects on the cardiovascular system. In contrast, exposure to high levels of alcohol for a long period could lead to progressive cardiac dysfunction and heart failure. Cardiac dysfunction associated with chronic and excessive alcohol intake is a specific cardiac disease known as alcoholic cardiomyopathy (ACM). In spite of its clinical importance, data on ACM and how alcohol damages the heart are limited. In this review, we evaluate available evidence linking excessive alcohol consumption with heart failure and dilated cardiomyopathy. Additionally, we discuss the clinical presentation, prognosis and treatment of ACM. PMID:25228956

  3. Effect of ethanol, carbon tetrachloride, and methyl ethyl ketone on butanol oxidase activity in rat lung and liver

    SciTech Connect

    Carlson, G.P. )

    1989-01-01

    Tha ability of the rat liver to oxidize 2-butanol via a cytochrome P-450-mediated mixed-function oxidase reaction is well known. The purpose of this study was to examine this microsomal alcohol oxidizing system in rat lung and determine if it could be altered by treatments that inhibit or induce this activity. 2-Butanol was incubated with microsomal preparations from male rats, and methyl ethyl ketone production was measured by gas chromatography. The rate was six to eight times lower in lung than in liver. Administration of low doses of ethanol (0.5 ml/kg and 1.0 ml/kg) ip for 7 d did not alter activity in the liver but was inhibitory in the lung, as was a high dose of 3.0 ml/kg in the liver. Carbon tetrachloride (1.0 ml/kg, ip) decreased activity in both tissues, especially the lung. The effects of the two inhibitors were not additive. Methyl ethyl ketone induced 2-butanol oxidation in both tissues. The lung possesses butanol oxidase activity that is alterable by both inhibitors and inducers.

  4. Aldehydic load and aldehyde dehydrogenase 2 profile during the progression of post-myocardial infarction cardiomyopathy: benefits of Alda-1

    PubMed Central

    Gomes, Katia M.S.; Bechara, Luiz R.G.; Lima, Vanessa M.; Ribeiro, Márcio A.C.; Campos, Juliane C.; Dourado, Paulo M.; Kowaltowski, Alicia J.; Mochly-Rosen, Daria; Ferreira, Julio C.B.

    2015-01-01

    Background/Objectives We previously demonstrated that reducing cardiac aldehydic load by aldehyde dehydrogenase 2 (ALDH2), a mitochondrial enzyme responsible for metabolizing the major lipid peroxidation product, protects against acute ischemia/reperfusion injury and chronic heart failure. However, time-dependent changes in ALDH2 profile, aldehydic load and mitochondrial bioenergetics during progression of post-myocardial infarction (post-MI) cardiomyopathy is unknown and should be established to determine the optimal time window for drug treatment. Methods Here we characterized cardiac ALDH2 activity and expression, lipid peroxidation, 4-hydroxy-2-nonenal (4-HNE) adduct formation, glutathione pool and mitochondrial energy metabolism and H2O2 release during the 4 weeks after permanent left anterior descending (LAD) coronary artery occlusion in rats. Results We observed a sustained disruption of cardiac mitochondrial function during the progression of post-MI cardiomyopathy, characterized by >50% reduced mitochondrial respiratory control ratios and up to 2 fold increase in H2O2 release. Mitochondrial dysfunction was accompanied by accumulation of cardiac and circulating lipid peroxides and 4-HNE protein adducts and down-regulation of electron transport chain complexes I and V. Moreover, increased aldehydic load was associated with a 90% reduction in cardiac ALDH2 activity and increased glutathione pool. Further supporting an ALDH2 mechanism, sustained Alda-1 treatment (starting 24hrs after permanent LAD occlusion surgery) prevented aldehydic overload, mitochondrial dysfunction and improved ventricular function in post-MI cardiomyopathy rats. Conclusion Taken together, our findings demonstrate a disrupted mitochondrial metabolism along with an insufficient cardiac ALDH2-mediated aldehyde clearance during the progression of ventricular dysfunction, suggesting a potential therapeutic value of ALDH2 activators during the progression of post-myocardial infarction

  5. Reactions of perfluoro-1-alkylcycloalkenes with alcohols and properties of vinyl ethers formed

    SciTech Connect

    Snegirev, V.F.; Makarov, K.N.

    1986-12-10

    Perfluoro-1-alkylcycloalkenes react with alcohols to form products of vinyl and allyl substitution. Alkyl perfluorocycloakenyl ethers readily alkylate the fluoride ion and triethylamine, and by the action of SbF/sub 5/ convert into ..cap alpha.., ..beta..-unsaturated perfluoro ketones. When allyl perfluorocycloalkenyl ethers are heated, they isomerize into the corresponding ..cap alpha..-allylperfluorocycloalkanones.

  6. Effects of aldehydes on the growth and lipid accumulation of oleaginous yeast Trichosporon fermentans.

    PubMed

    Huang, Chao; Wu, Hong; Liu, Qiu-ping; Li, Yuan-yuan; Zong, Min-hua

    2011-05-11

    The effects of five representative aldehydes in lignocellulosic hydrolysates on the growth and the lipid accumulation of oleaginous yeast Trichosporon fermentans were investigated for the first time. There was no relationship between the hydrophobicity and the toxicity of aldehyde, and 5-hydroxymethylfurfural was less toxic than aromatic aldehydes and furfural. Binary combination of aromatic aldehydes caused a synergistic inhibitory effect, but combination of furan and aromatic aldehydes reduced the inhibition instead. A longer lag phase was found due to the presence of aldehydes and the decrease of sugar consumption rate, but more xylose was utilized by T. fermentans in the presence of aldehydes, especially at their low concentrations. The variation of malic enzyme activity was not related to the delay of lipid accumulation. Furthermore, the inhibition of aldehydes on cell growth was more dependent on inoculum size, temperature, and initial pH than that on lipid content. PMID:21443267

  7. Applicability of the theory of thermodynamic similarity to predict the enthalpies of vaporization of aliphatic aldehydes

    NASA Astrophysics Data System (ADS)

    Esina, Z. N.; Korchuganova, M. R.

    2015-06-01

    The theory of thermodynamic similarity is used to predict the enthalpies of vaporization of aliphatic aldehydes. The predicted data allow us to calculate the phase diagrams of liquid-vapor equilibrium in a binary water-aliphatic aldehyde system.

  8. Direct N-acylation of lactams, oxazolidinones, and imidazolidinones with aldehydes by Shvo's catalyst.

    PubMed

    Zhang, Jian; Hong, Soon Hyeok

    2012-09-01

    Direct N-acylation of lactams, oxazolidinones, and imidazolidinones was achieved with aldehydes by Shvo's catalyst without using any other stoichiometric reagent. The N-acylations with α,β-unsaturated aldehydes were achieved with excellent yields. PMID:22913512

  9. Advanced selective non-invasive ketone body detection sensors based on new ionophores

    NASA Astrophysics Data System (ADS)

    Sathyapalan, A.; Sarswat, P. K.; Zhu, Y.; Free, M. L.

    2014-12-01

    New molecules and methods were examined that can be used to detect trace level ketone bodies. Diseases such as type 1 diabetes, childhood hypo-glycaemia-growth hormone deficiency, toxic inhalation, and body metabolism changes are linked with ketone bodies concentration. Here we introduce, selective ketone body detection sensors based on small, environmentally friendly organic molecules with Lewis acid additives. Density functional theory (DFT) simulation of the sensor molecules (Bromo-acetonaphthone tungstate (BANT) and acetonaphthophenyl ether propiono hydroxyl tungstate (APPHT)), indicated a fully relaxed geometry without symmetry attributes and specific coordination which enhances ketone bodies sensitivity. A portable sensing unit was made in which detection media containing ketone bodies at low concentration and new molecules show color change in visible light as well as unique irradiance during UV illumination. RGB analysis, electrochemical tests, SEM characterization, FTIR, absorbance and emission spectroscopy were also performed in order to validate the ketone sensitivity of these new molecules.

  10. Overview of Alcohol Consumption

    MedlinePlus

    ... Search Alcohol & Your Health Overview of Alcohol Consumption Alcohol's Effects on the Body Alcohol Use Disorder Fetal Alcohol ... other questions about alcohol. Here’s what we know: Alcohol’s effects vary from person to person, depending on a ...

  11. Highly efficient and reusable CNT supported iron(ii) catalyst for microwave assisted alcohol oxidation.

    PubMed

    Martins, L M D R S; Ribeiro, A P C; Carabineiro, S A C; Figueiredo, J L; Pombeiro, A J L

    2016-04-19

    The highly efficient eco-friendly synthesis of ketones (yields over 99%) from secondary alcohols is achieved by combination of [FeCl2{η(3)-HC(pz)3}] (pz = pyrazol-1-yl) supported on functionalized multi-walled carbon nanotubes and microwave irradiation, in a solvent-free medium. The carbon homoscorpionate iron(ii) complex is the first one of this class to be used as catalyst for the oxidation of alcohols. PMID:27007743

  12. Discovery and SAR of a novel series of potent, CNS penetrant M4 PAMs based on a non-enolizable ketone core: Challenges in disposition.

    PubMed

    Wood, Michael R; Noetzel, Meredith J; Tarr, James C; Rodriguez, Alice L; Lamsal, Atin; Chang, Sichen; Foster, Jarrett J; Smith, Emery; Chase, Peter; Hodder, Peter S; Engers, Darren W; Niswender, Colleen M; Brandon, Nicholas J; Wood, Michael W; Duggan, Mark E; Conn, P Jeffrey; Bridges, Thomas M; Lindsley, Craig W

    2016-09-01

    This Letter describes the chemical optimization of a novel series of M4 PAMs based on a non-enolizable ketone core, identified from an MLPCN functional high-throughput screen. The HTS hit was potent, selective and CNS penetrant; however, the compound was highly cleared in vitro and in vivo. SAR provided analogs for which M4 PAM potency and CNS exposure were maintained; yet, clearance remained high. Metabolite identification studies demonstrated that this series was subject to rapid, and near quantitative, reductive metabolism to the corresponding secondary alcohol metabolite that was devoid of M4 PAM activity. PMID:27476142

  13. Biosynthesis of odd-chain fatty alcohols in Escherichia coli.

    PubMed

    Cao, Ying-Xiu; Xiao, Wen-Hai; Liu, Duo; Zhang, Jin-Lai; Ding, Ming-Zhu; Yuan, Ying-Jin

    2015-05-01

    Engineered microbes offer the opportunity to design and implement artificial molecular pathways for renewable production of tailored chemical commodities. Targeted biosynthesis of odd-chain fatty alcohols is very challenging in microbe, due to the specificity of fatty acids synthase for two-carbon unit elongation. Here, we developed a novel strategy to directly tailor carbon number in fatty aldehydes formation step by incorporating α-dioxygenase (αDOX) from Oryza sativa (rice) into Escherichia coli αDOX oxidizes Cn fatty acids (even-chain) to form Cn-1 fatty aldehydes (odd-chain). Through combining αDOX with fatty acyl-acyl carrier protein (-ACP) thioesterase (TE) and aldehyde reductase (AHR), the medium odd-chain fatty alcohols profile (C11, C13, C15) was firstly established in E. coli. Also, medium even-chain alkanes (C12, C14) were obtained by substitution of AHR to aldehyde decarbonylase (AD). The titer of odd-chain fatty alcohols was improved from 7.4mg/L to 101.5mg/L in tube cultivation by means of fine-tuning endogenous fatty acyl-ACP TE (TesA'), αDOX, AHRs and the genes involved in fatty acids metabolism pathway. Through high cell density fed-batch fermentation, a titer of 1.95g/L odd-chain fatty alcohols was achieved, which was the highest reported titer in E. coli. Our system has greatly expanded the current microbial fatty alcohols profile that provides a new brand solution for producing complex and desired molecules in microbes. PMID:25773521

  14. Acute cardiopulmonary toxicity of inhaled aldehydes: role of TRPA1.

    PubMed

    Conklin, Daniel J

    2016-06-01

    Inhalation of high-level volatile aldehydes, as present in smoke from wildfires and in tobacco smoke, is associated with both acute and chronic cardiopulmonary morbidity and mortality, but the underlying mechanisms are unclear. The transient receptor potential ankyrin 1 (TRPA1) protein forms a cation channel (irritant receptor) that mediates tobacco smoke-induced airway and lung injury, yet the role of TRPA1 in the cardiovascular toxicity of aldehyde exposure is unclear. Physiologically, airway-located TRPA1 activation triggers an irritant response (e.g., coughing and "respiratory braking") that alters the rate and depth of breathing to reduce exposure. Acrolein (2-propenal), a volatile, unsaturated aldehyde, activates TRPA1. Acrolein was used as a chemical weapon in World War I and is present at high levels in wildfires and tobacco smoke. Acrolein is thought to contribute to pulmonary and cardiovascular injury caused by tobacco smoke exposure, although the role of TRPA1 in cardiovascular toxicity is unclear. This minireview addresses this gap in our knowledge by exploring literature and recent data indicating a connection between TRPA1 and cardiovascular as well as pulmonary injury due to inhaled aldehydes. PMID:27152448

  15. A thermostable transketolase evolved for aliphatic aldehyde acceptors.

    PubMed

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

    2015-01-11

    Directed evolution of the thermostable transketolase from Geobacillus stearothermophilus based on a pH-based colorimetric screening of smart libraries yielded several mutants with up to 16-fold higher activity for aliphatic aldehydes and high enantioselectivity (>95% ee) in the asymmetric carboligation step. PMID:25415647

  16. 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

  17. New preparation of diethyl methylformylphosphonate dimethylhydrazone: A reagent for aldehyde homologation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The phosphonate reagent, diethyl methylformyl-2-phosphonate dimethylhydrazone contains a protected aldehyde group instead of the usual ester group. It can be used for the two-carbon homologation of aldehydes to a, ß-unsaturated aldehydes. The reagent can be prepared in good overall yield (82%) and...

  18. Derivatization Strategy for the Comprehensive Characterization of Endogenous Fatty Aldehydes Using HPLC-Multiple Reaction Monitoring.

    PubMed

    Tie, Cai; Hu, Ting; Jia, Zhi-Xin; Zhang, Jin-Lan

    2016-08-01

    Fatty aldehydes are crucial substances that mediate a wide range of vital physiological functions, particularly lipid peroxidation. Fatty aldehydes such as acrolein and 4-hydroxynonenal (4-HNE) are considered potential biomarkers of myocardial ischemia and dementia, but analytical techniques for fatty aldehydes are lacking. In the present study, a comprehensive characterization strategy with high sensitivity and facility for fatty aldehydes based on derivatization and high-performance liquid chromatography-multiple reaction monitoring (HPLC-MRM) was developed. The fatty aldehydes of a biosample were derivatized using 2,4-bis(diethylamino)-6-hydrazino-1,3,5-triazine under mild and efficient reaction conditions at 37 °C for 15 min. The limit of detection (LOD) of the fatty aldehydes varied from 0.1 to 1 pg/mL, depending on the structures of these molecules. General MRM parameters were forged for the analysis of endogenous fatty aldehydes. "Heavy" derivatization reagents with 20 deuterium atoms were synthesized for both the discovery and comprehensive characterization of fatty aldehydes. More than 80 fatty aldehydes were detected in the biosamples. The new strategy was successfully implemented in global fatty aldehyde profiling of plasma and brain tissue of the bilateral common carotid artery (2VO) dementia rat model. Dozens of fatty aldehydes were significantly changed between the control and model groups. These findings further highlight the importance of endogenous fatty aldehydes. PMID:27397858

  19. An Iron Catalyst for Ketone Hydrogenations Under Mild Conditions

    SciTech Connect

    Bullock, R. Morris

    2007-10-01

    Casey and Guan reported a homogeneous catalyst for ketone hydrogenation that does not require a precious metal, but instead is based on iron. Excellent yields and chemoselectivity for hydrogenation are found under mild conditions (25 °C, 3 atm H2). An ionic hydrogenation mechanism allows the delivery of a proton from the OH and a hydride from the metal. RMB gratefully acknowledges funding from the Division of Chemical Sciences, Office of Basic Energy Sciences, US Department of Energy, and from a grant from the Laboratory Directed Research and Development Program. Pacific Northwest National Laboratory is operated by Battelle for the U.S. Department of Energy.

  20. Effects of trifluoromethyl ketones on the motility of Proteus vulgaris.

    PubMed

    Wolfart, Krisztina; Molnar, Annamaria; Kawase, Masami; Motohashi, Noboru; Molnar, Joseph

    2004-09-01

    In the present study, we showed the inhibition of motility by trifluoromethyl ketone (TF) derivatives (1-8) in Proteus vulgaris (P. vulgaris) cultures. Among them, 1-(2-benzoxazoyl)-3,3,3-trifluoro-2-propanone (1) showed a much stronger inhibitory effect on the motility of P. vulgaris than other TF compounds at 10% MIC. Our results suggest the possibility of an inhibitory action of TF compounds on the proton motive forces by affecting the action of biological motor and proton efflux in the membranes, resulting in a reduction of the ratio of running and the increased number of tumbling and non-motile cells. PMID:15340240