High-effective approach from amino acid esters to chiral amino alcohols over Cu/ZnO/Al2O3 catalyst and its catalytic reaction mechanism

PubMed Central

Zhang, Shuangshuang; Yu, Jun; Li, Huiying; Mao, Dongsen; Lu, Guanzhong

2016-01-01

Developing the high-efficient and green synthetic method for chiral amino alcohols is an intriguing target. We have developed the Mg2+-doped Cu/ZnO/Al2O3 catalyst for hydrogenation of L-phenylalanine methyl ester to chiral L-phenylalaninol without racemization. The effect of different L-phenylalanine esters on this title reaction was studied, verifying that Cu/ZnO/Al2O3 is an excellent catalyst for the hydrogenation of amino acid esters to chiral amino alcohols. DFT calculation was used to study the adsorption of substrate on the catalyst, and showed that the substrate adsorbs on the surface active sites mainly by amino group (-NH2) absorbed on Al2O3, and carbonyl (C=O) and alkoxy (RO-) group oxygen absorbed on the boundary of Cu and Al2O3. This catalytic hydrogenation undergoes the formation of a hemiacetal intermediate and the cleavage of the C–O bond (rate-determining step) by reacting with dissociated H to obtain amino aldehyde and methanol ad-species. The former is further hydrogenated to amino alcohols, and the latter desorbs from the catalyst surface. PMID:27619990

Tuning the catalytic CO hydrogenation to straight- and long-chain aldehydes/alcohols and olefins/paraffins

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xiang, Yizhi; Kruse, Norbert

Here, the catalytic CO hydrogenation is one of the most versatile large-scale chemical syntheses leading to variable chemical feedstock. While traditionally mainly methanol and long-chain hydrocarbons are produced by CO hydrogenation, here we show that the same reaction can be tuned to produce long-chain n-aldehydes, 1-alcohols and olefins, as well as n-paraffins over potassium-promoted CoMn catalysts. The sum selectivity of aldehydes and alcohols is usually >50 wt% whereof up to ~97% can be n-aldehydes. While the product slate contains ~60% n-aldehydes at /p CO=0.5, a 65/35% slate of paraffins/alcohols is obtained at a ratio of 9. A linear Anderson–Schulz–Flory behaviour,more » independent of the /p CO ratio, is found for the sum of C 4+ products. We advocate a synergistic interaction between a Mn 5O 8 oxide and a bulk Co 2C phase, promoted by the presence of potassium, to be responsible for the unique product spectra in our studies.« less

Tuning the catalytic CO hydrogenation to straight- and long-chain aldehydes/alcohols and olefins/paraffins

DOE PAGES

Xiang, Yizhi; Kruse, Norbert

2016-10-06

Here, the catalytic CO hydrogenation is one of the most versatile large-scale chemical syntheses leading to variable chemical feedstock. While traditionally mainly methanol and long-chain hydrocarbons are produced by CO hydrogenation, here we show that the same reaction can be tuned to produce long-chain n-aldehydes, 1-alcohols and olefins, as well as n-paraffins over potassium-promoted CoMn catalysts. The sum selectivity of aldehydes and alcohols is usually >50 wt% whereof up to ~97% can be n-aldehydes. While the product slate contains ~60% n-aldehydes at /p CO=0.5, a 65/35% slate of paraffins/alcohols is obtained at a ratio of 9. A linear Anderson–Schulz–Flory behaviour,more » independent of the /p CO ratio, is found for the sum of C 4+ products. We advocate a synergistic interaction between a Mn 5O 8 oxide and a bulk Co 2C phase, promoted by the presence of potassium, to be responsible for the unique product spectra in our studies.« less

Two-carbon homologation of aldehydes and ketones to α,β-unsaturated aldehydes.

PubMed

Petroski, Richard J; Vermillion, Karl; Cossé, Allard A

2011-06-17

Phosphonate reagents were developed for the two-carbon homologation of aldehydes or ketones to unbranched- or methyl-branched α,β-unsaturated aldehydes. The phosphonate reagents, diethyl methylformyl-2-phosphonate dimethylhydrazone and diethyl ethylformyl-2-phosphonate dimethylhydrazone, contained a protected aldehyde group instead of the usual ester group. A homologation cycle entailed condensation of the reagent with the starting aldehyde, followed by removal of the dimethylhydrazone protective group with a biphasic mixture of 1 M HCl and petroleum ether. This robust two-step process worked with a variety of aldehydes and ketones. Overall isolated yields of unsaturated aldehyde products ranged from 71% to 86% after the condensation and deprotection steps.

Direct conversion of alcohols to α-chloro aldehydes and α-chloro ketones.

PubMed

Jing, Yuanyuan; Daniliuc, Constantin G; Studer, Armido

2014-09-19

Direct conversion of primary and secondary alcohols into the corresponding α-chloro aldehydes and α-chloro ketones using trichloroisocyanuric acid, serving both as stoichiometric oxidant and α-halogenating reagent, is reported. For primary alcohols, TEMPO has to be added as an oxidation catalyst, and for the transformation of secondary alcohols (TEMPO-free protocol), MeOH as an additive is essential to promote chlorination of the intermediary ketones.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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.

Cu-catalyzed C(sp³)-H bond activation reaction for direct preparation of cycloallyl esters from cycloalkanes and aromatic aldehydes.

PubMed

Zhao, Jincan; Fang, Hong; Han, Jianlin; Pan, Yi

2014-05-02

Cu-catalyzed dehydrogenation-olefination and esterification of C(sp(3))-H bonds of cycloalkanes with TBHP as an oxidant has been developed. The reaction involves four C-H bond activations and gives cycloallyl ester products directly from cycloalkanes and aromatic aldehydes.

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.

Efficient and Highly Selective Solvent-Free Oxidation of Primary Alcohols to Aldehydes Using Bucky Nanodiamond.

PubMed

Lin, Yangming; Wu, Kuang-Hsu Tim; Yu, Linhui; Heumann, Saskia; Su, Dang Sheng

2017-09-11

Selective oxidation of alcohols to aldehydes is widely applicable to the synthesis of various green chemicals. The poor chemoselectivity for complicated primary aldehydes over state-of-the-art metal-free or metal-based catalysts represents a major obstacle for industrial application. Bucky nanodiamond is a potential green catalyst that exhibits excellent chemoselectivity and cycling stability for the selective oxidation of primary alcohols in diverse structures (22 examples, including aromatic, substituted aromatic, unsaturated, heterocyclic, and linear chain alcohols) to their corresponding aldehydes. The results are comparable to reported transition-metal catalysts including conventional Pt/C and Ru/C catalysts for certain substrates under solvent-free conditions. The possible activation process of the oxidant and substrates by the surface oxygen groups and defect species are revealed with model catalysts, ex situ electrochemical measurements, and ex situ attenuated total reflectance. The zigzag edges of sp 2 carbon planes are shown to play a key role in these reactions. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Copper(I)/TEMPO Catalyzed Aerobic Oxidation of Primary Alcohols to Aldehydes with Ambient Air

PubMed Central

Hoover, Jessica M.; Steves, Janelle E.; Stahl, Shannon S.

2012-01-01

This protocol describes a practical laboratory-scale method for aerobic oxidation of primary alcohols to aldehydes, using a chemoselective CuI/TEMPO catalyst system. The catalyst is prepared in situ from commercially available reagents, and the reactions are performed in a common organic solvent (acetonitrile) with ambient air as the oxidant. Three different reaction conditions and three procedures for the isolation and purification of the aldehyde product are presented. The oxidations of eight different alcohols, described here, include representative examples of each reaction condition and purification method. Reaction times vary from 20 min to 24 h, depending on the alcohol, while the purification methods each take about 2 h. The total time necessary for the complete protocol ranges from 3 – 26 h. PMID:22635108

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.

Organocatalytic sequential alpha-amination-Horner-Wadsworth-Emmons olefination of aldehydes: enantioselective synthesis of gamma-amino-alpha,beta-unsaturated esters.

PubMed

Kotkar, Shriram P; Chavan, Vilas B; Sudalai, Arumugam

2007-03-15

A novel and highly enantioselective method for the synthesis of gamma-amino-alpha,beta-unsaturated esters via tandem alpha-amination-Horner-Wadsworth-Emmons (HWE) olefination of aldehydes is described. The one-pot assembly has been demonstrated for the construction of functionalized chiral 2-pyrrolidones, subunits present in several alkaloids. [structure: see text

Selective aerobic oxidation of primary alcohols to aldehydes over Nb2O5 photocatalyst with visible light.

PubMed

Furukawa, Shinya; Shishido, Tetsuya; Teramura, Kentaro; Tanaka, Tsunehiro

2014-09-15

Primary alcohols are selectively converted into aldehydes by using a Nb(2)O(5) photocatalyst under visible-light irradiation. A strong interaction between the alcohol and Nb(2)O(5) generates a donor level within the forbidden band of Nb(2)O(5), which provides a visible-light-harvesting ability. Over oxidation of aldehydes into carboxylic acids does not proceed under visible-light irradiation. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

Trail Pheromones: Responses of the Texas Leafcutting Ant, Atta texana to Select Halo- and Cyanopyrrole-2-Aldehydes, Ketones, and Esters

Treesearch

P. E. Sonnet; John C. Moser

1973-01-01

Several halo- and cyanopyrroles related to the trail pheromone of Atta texana (Buckley), were prepared and tested by a faster and more sensitive bioassay that was previously available. Responsiveness of the ants in descending order to these compounds, based on the substituent in the number two position, is: esters, methyl ketones, aldehydes. Slight...

Sinterable Ceramic Powders from Laser-Heated Gases.

DTIC Science & Technology

1988-02-01

ether . carboxylic acid. and aldehyde clases: water is also included.Acrigto William and Goodman.’ a single crystalline sili- The single-crstalline...represent commonly available organic families, Including aliphatic and aromatic hydrocarbons, chlorides, ethers , ketones , esters, alcohols, aldehydes...Hydrocarbons Ketone Amine Chlorides Low-alcohols 8f . Ether Ester - _Aldehyde Ether Ketones High-alcohols 04 Carboxylic Ester I acid Ether o . Nitrile

Substituent effect of phenolic aldehyde inhibition on alcoholic fermentation by Saccharomyces cerevisiae

Treesearch

Rui Xie; Maobing Tu; Thomas Elder

2016-01-01

Phenolic compounds significantly inhibit microbial fermentation of biomass hydrolysates. To understand thequantitative structure-inhibition relationship of phenolic aldehydes on alcoholic fermentation, the effect of 11 differentsubstituted benzaldehydes on the final ethanol yield was examined. The results showed that the degree of phenolic...

Initial steps of the peroxidase-catalyzed polymerization of coniferyl alcohol and/or sinapyl aldehyde: capillary zone electrophoresis study of pH effect.

PubMed

Fournand, David; Cathala, Bernard; Lapierre, Catherine

2003-01-01

Capillary zone electrophoresis has been used to monitor the first steps of the dehydrogenative polymerization of coniferyl alcohol, sinapyl aldehyde, or a mixture of both, catalyzed by the horseradish peroxidase (HRP)-H(2)O(2) system. When coniferyl alcohol was the unique HRP substrate, three major dimers were observed (beta-5, beta-beta, and beta-O-4 interunit linkages) and their initial formation velocity as well as their relative abundance varied with pH. The beta-O-4 interunit linkage was thus slightly favored at lower pH values. In contrast, sinapyl aldehyde turned out to be a very poor substrate for HRP except in basic conditions (pH 8). The major dimer observed was the beta,beta'-di-sinapyl aldehyde, a red-brown exhibiting compound which might partly participate in the red coloration usually observed in cinnamyl alcohol dehydrogenase-deficient angiosperms. Finally, when a mixture of coniferyl alcohol and sinapyl aldehyde was used, it looked as if sinapyl aldehyde became a very good substrate for HRP. Indeed, coniferyl alcohol turned out to serve as a redox mediator (i.e. "shuttle oxidant") for the sinapyl aldehyde incorporation in the lignin-like polymer. This means that in particular conditions the specificity of oxidative enzymes might not hinder the incorporation of poor substrates into the growing lignin polymer.

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.

40 CFR 721.6477 - Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols, reaction products with maleic...

Code of Federal Regulations, 2011 CFR

2011-07-01

... with ethoxylated fatty alcohols, reaction products with maleic anhydride. 721.6477 Section 721.6477... Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols, reaction products with maleic... identified generically as alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols, reaction...

40 CFR 721.6477 - Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols, reaction products with maleic...

Code of Federal Regulations, 2010 CFR

2010-07-01

... with ethoxylated fatty alcohols, reaction products with maleic anhydride. 721.6477 Section 721.6477... Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols, reaction products with maleic... identified generically as alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols, reaction...

27 CFR 24.183 - Use of distillates containing aldehydes.

Code of Federal Regulations, 2013 CFR

2013-04-01

... containing aldehydes. 24.183 Section 24.183 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX... distillates containing aldehydes. Distillates containing aldehydes may be received on wine premises for use in... fermentation of wine made from a different kind of fruit. Distillates containing aldehydes which are received...

27 CFR 24.183 - Use of distillates containing aldehydes.

Code of Federal Regulations, 2012 CFR

2012-04-01

... containing aldehydes. 24.183 Section 24.183 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX... distillates containing aldehydes. Distillates containing aldehydes may be received on wine premises for use in... fermentation of wine made from a different kind of fruit. Distillates containing aldehydes which are received...

27 CFR 24.183 - Use of distillates containing aldehydes.

Code of Federal Regulations, 2014 CFR

2014-04-01

... containing aldehydes. 24.183 Section 24.183 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX... distillates containing aldehydes. Distillates containing aldehydes may be received on wine premises for use in... fermentation of wine made from a different kind of fruit. Distillates containing aldehydes which are received...

27 CFR 24.183 - Use of distillates containing aldehydes.

Code of Federal Regulations, 2011 CFR

2011-04-01

... containing aldehydes. 24.183 Section 24.183 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX... distillates containing aldehydes. Distillates containing aldehydes may be received on wine premises for use in... fermentation of wine made from a different kind of fruit. Distillates containing aldehydes which are received...

Spin-Center Shift-Enabled Direct Enantioselective α-Benzylation of Aldehydes with Alcohols.

PubMed

Nacsa, Eric D; MacMillan, David W C

2018-03-07

Nature routinely engages alcohols as leaving groups, as DNA biosynthesis relies on the removal of water from ribonucleoside diphosphates by a radical-mediated "spin-center shift" (SCS) mechanism. Alcohols, however, remain underused as alkylating agents in synthetic chemistry due to their low reactivity in two-electron pathways. We report herein an enantioselective α-benzylation of aldehydes using alcohols as alkylating agents based on the mechanistic principle of spin-center shift. This strategy harnesses the dual activation modes of photoredox and organocatalysis, engaging the alcohol by SCS and capturing the resulting benzylic radical with a catalytically generated enamine. Mechanistic studies provide evidence for SCS as a key elementary step, identify the origins of competing reactions, and enable improvements in chemoselectivity by rational photocatalyst design.

Highly efficient Cu(I)-catalyzed oxidation of alcohols to ketones and aldehydes with diaziridinone.

PubMed

Zhu, Yingguang; Zhao, Baoguo; Shi, Yian

2013-03-01

A novel and efficient Cu(I)-catalyzed oxidation of alcohols has been achieved with di-tert-butyldiaziridinone as the oxidant under mild conditions. A wide variety of primary and secondary alcohols with various functional groups can be oxidized to aldehydes and ketones in high yields. The reaction proceeds under neutral conditions making it compatible with acid- or base-sensitive substrates, and it is amenable to gram scale.

Study of a specific lignin model: γ-oxidation and how it influences the hydrolysis efficiency of alcohol-aldehyde dehydrogenation copolymers.

PubMed

Bouxin, Florent; Baumberger, Stéphanie; Renault, Jean-Hugues; Dole, Patrice

2011-05-01

Six coniferyl alcohol-coniferaldehyde dehydrogenation copolymers (DHcoPs) were synthesized in order to determine the influence of an increased number of aldehyde functions on hydrolysis. After heterogeneous hydrolysis using acidic Montmorillonite K10 clay, the DHcoPs were thioacidolyzed and analyzed by gel permeation chromatography (GPC). Comparison of the thioacidolyzed products, with and without the hydrolysis step, showed that there was a greater proportion of condensation reaction in the absence of aldehyde. When the coniferaldehyde content in the initial synthetic mixture was more than 30% (w/w), only a low fraction of condensed products was generated during the K10 clay hydrolysis step. This suggests that condensation pathways are mainly due to the alcohol present in the γ-position in the DHcoPs. Investigation of the reactivity and the potential condensation of aldehyde and alcohol monomers under hydrolysis conditions showed the important conversion of coniferyl alcohol and conversely the stability of coniferaldehyde. Copyright © 2011 Elsevier Ltd. All rights reserved.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaspera, Ruediger; Sahele, Tariku; Lakatos, Kyle

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. Themore » 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.« less

Diene Hydroacylation from the Alcohol or Aldehyde Oxidation Level via Ruthenium Catalyzed C-C Bond Forming Transfer Hydrogenation: Synthesis of β,γ-Unsaturated Ketones

PubMed Central

Shibahara, Fumitoshi; Bower, John F.; Krische, Michael J.

2011-01-01

Under the conditions of ruthenium catalyzed transfer hydrogenation, isoprene couples to benzylic and aliphatic alcohols 1a–1g to deliver β,γ-unsaturated ketones 3a–3g in good to excellent isolated yields. Under identical conditions, aldehydes 2a–2g couple to isoprene to provide an identical set of β,γ-unsaturated ketones 3a–3g in good to excellent isolated yields. As demonstrated by the coupling of butadiene, myrcene and 1,2-dimethylbutadiene to representative alcohols 1b, 1c and 1e, diverse acyclic dienes participate in transfer hydrogenative coupling to form β,γ-unsaturated ketones. In all cases, complete branch-regioselectivity is observed and, with the exception of adduct 3j, isomerization to the conjugated enone is not detected. Thus, formal intermolecular diene hydroacylation is achieved from the alcohol or aldehyde oxidation level. In earlier studies employing a related ruthenium catalyst, acyclic dienes were coupled to carbonyl partners from the alcohol or aldehyde oxidation level to furnish branched homoallylic alcohols. Thus, under transfer hydrogenative coupling conditions, all oxidations levels of substrate (alcohol or aldehyde) and product (homoallyl alcohol or β,γ-unsaturated ketone) are accessible. PMID:18841895

Deoxygenation of Unhindered Alcohols via Reductive Dealkylation of Derived Phosphate Esters

DOE PAGES

Chowdhury, Sarwat; Standaert, Robert F.

2016-09-15

Primary alcohols can be deoxygenated cleanly and in high yield by reduction of derived diphenyl phosphate esters with lithium triethylborohydride in tetrahydrofuran at room temperature. Selective deoxygenation of a primary alcohol in the presence of a secondary alcohol was demonstrated. The two-step process can be performed in one pot, making it both simple and convenient.

Highly Efficient Cu(I)-Catalyzed Oxidation of Alcohols to Ketones and Aldehydes with Diaziridinone

PubMed Central

Zhu, Yingguang; Zhao, Baoguo

2013-01-01

A novel and efficient Cu(I)-catalyzed oxidation of alcohols has been achieved with di-tert-butyldiaziridinone as oxidant under mild conditions. A wide variety of primary and secondary alcohols with various functional groups can be oxidized to aldehydes and ketones in high yields. The reaction proceeds under neutral conditions making it compatible with acid or base-sensitive substrates, and it is amenable to gram scale. PMID:23413952

N-heterocyclic carbene catalyzed regioselective oxo-acyloxylation of alkenes with aromatic aldehydes: a high yield synthesis of α-acyloxy ketones and esters.

PubMed

Reddi, Rambabu N; Malekar, Pushpa V; Sudalai, Arumugam

2013-10-14

An N-heterocyclic carbene (NHC)-catalyzed reaction of alkenes with aromatic aldehydes providing for a high yield synthesis of α-acyloxy ketones and esters has been described. This unprecedented regioselective oxidative process employs NBS and Et3N in stoichiometric amounts and O2 (1 atm) as an oxidant under ambient conditions in DMSO as a solvent.

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.

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

New preparation of diethyl methylformylphosphonate dimethylhydrazone: A reagent for aldehyde homologation

USDA-ARS?s Scientific Manuscript database

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...

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

PubMed

Rodriguez, Gabriel M; Atsumi, Shota

2014-09-01

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. Copyright © 2014 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

Synthesis of robalzotan, ebalzotan, and rotigotine precursors via the stereoselective multienzymatic cascade reduction of α,β-unsaturated aldehydes.

PubMed

Brenna, Elisabetta; Gatti, Francesco G; Malpezzi, Luciana; Monti, Daniela; Parmeggiani, Fabio; Sacchetti, Alessandro

2013-05-17

A stereoselective synthesis of bicyclic primary or secondary amines, based on tetralin or chroman structural moieties, is reported. These amines are precursors of important active pharmaceutical ingredients such as rotigotine (Neupro), robalzotan, and ebalzotan. The key step is based on a multienzymatic reduction of an α,β-unsaturated aldehyde or ketone to give the saturated primary or secondary alcohol, in a high yield and with a high ee. The catalytic system consists of the combination of an ene-reductase (ER; i.e., OYE2 or OYE3 belonging to the Old Yellow Enzyme family) with an alcohol dehydrogenase (ADH), applying the in situ substrate feeding product removal technology. By this system the formation of the allylic alcohol side product and the racemization of the chirally unstable α-substituted aldehyde intermediate are minimized. The primary alcohols were elaborated via a Curtius rearrangement. The combination of OYE2 with a Prelog or an anti-Prelog ADH allowed the preparation of the secondary alcohols with ee > 99% and de > 87%. The absolute configuration of the primary amines was unambiguously assigned by comparison with authentic samples. The stereochemistry of secondary alcohols was assigned by X-ray crystal structure and NMR analysis of Mosher esters.

Dual palladium- and proline-catalyzed allylic alkylation of enolizable ketones and aldehydes with allylic alcohols.

PubMed

Usui, Ippei; Schmidt, Stefan; Breit, Bernhard

2009-03-19

The dual Pd/proline-catalyzed alpha-allylation reaction of a variety of enolizable ketones and aldehydes with allylic alcohols is described. In this reaction, the choice of a large-bite angle ligand Xantphos and proline as the organocatalyst was essential for generation of the crucial pi-allyl Pd intermediate from allylic alcohol, followed by nucleophilic attack of the enamine formed in situ from the corresponding enolizable carbonyl substrate and proline.

Advanced emissions-speciation methodologies for the auto/oil air-quality improvement research program. 2. Aldehydes, ketones, and alcohols. SAE technical paper series

DOE Office of Scientific and Technical Information (OSTI.GOV)

Swarin, S.J.; Loo, J.F.; Chladek, E.

1992-01-01

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 individual reformulated fuels, individual vehicles, and for air modeling studies. The emission samples are collected in impingers which contain either 2,4-dinitrophenylhydrazine solution for the aldehydes and ketones or deionized water for the alcohols. Subsequent analyses by liquid chromatography for the aldehydes and ketones and gas chromatography for the alcohols utilized auto injectors and computerized data systems which permit high sample throughput with minimalmore » operator intervention. The quality control procedures developed and interlaboratory comparisons conducted as part of the program are also described. (Copyright (c) 1992 Society of Automotive Engineers, Inc.)« less

Origin of the selectivity in the gold-mediated oxidation of benzyl alcohol

NASA Astrophysics Data System (ADS)

Rodríguez-Reyes, Juan Carlos F.; Friend, Cynthia M.; Madix, Robert J.

2012-08-01

Benzyl alcohol has received substantial attention as a probe molecule to test the selectivity and efficiency of novel metallic gold catalysts. Herein, the mechanisms of benzyl alcohol oxidation on a gold surface covered with atomic oxygen are elucidated; the results show direct correspondence to the reaction on gold-based catalysts. The selective, partial oxidation of benzyl alcohol to benzaldehyde is achieved with low oxygen surface concentrations and takes place through dehydrogenation of the alcohol to form benzaldehyde via a benzyloxy (C6H5-CH2O) intermediate. While in this case atomic oxygen plays solely a dehydrogenating role, at higher concentrations it leads to the formation of intermediates from benzaldehyde, producing benzoic acid and CO2. Facile ester (benzyl benzoate) formation also occurs at low oxygen concentrations, which indicates that benzoic acid is not a precursor of further oxidation of the ester; instead, the ester is produced by the coupling of adsorbed benzyloxy and benzaldehyde. Key to the high selectivity seen at low oxygen concentrations is the fact that the production of the aldehyde (and esters) is kinetically favored over the production of benzoic acid.

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. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effects of Blending Alcohols with Poultry Fat Methyl Esters on Cold Flow Properties

USDA-ARS?s Scientific Manuscript database

The low temperature operability, kinematic viscosity, and acid value of poultry fat methyl esters were improved with addition of ethanol, isopropanol, and butanol in a linear fashion with increasing alcohol content. The flash point decreased and moisture content increased upon addition of alcohols t...

Regulation of Saccharomyces cerevisiae genetic engineering on the production of acetate esters and higher alcohols during Chinese Baijiu fermentation.

PubMed

Li, Wei; Wang, Jian-Hui; Zhang, Cui-Ying; Ma, Hong-Xia; Xiao, Dong-Guang

2017-06-01

Acetate esters and higher alcohols greatly influence the quality and flavor profiles of Chinese Baijiu (Chinese liquor). Various mutants have been constructed to investigate the interactions of ATF1 overexpression, IAH1 deletion, and BAT2 deletion on the production of acetate esters and higher alcohols. The results showed that the overexpression of ATF1 under the control of the PGK1 promoter with BAT2 and IAH1 double-gene deletion led to a higher production of acetate esters and a lower production of higher alcohols than the overexpression of ATF1 with IAH1 deletion or overexpression of ATF1 with BAT2 deletion. Moreover, deletion of IAH1 in ATF1 overexpression strains effectively increased the production of isobutyl acetate and isoamyl acetate by reducing the hydrolysis of acetate esters. The decline in the production of higher alcohol by the ATF1 overexpression strains with BAT2 deletion is due to the interaction of ATF1 overexpression and BAT2 deletion. Mutants with varying abilities of producing acetate esters and higher alcohols were developed by genetic engineering. These strains have great potential for industrial application.

Evaluating the Intoxicating Degree of Liquor Products with Combinations of Fusel Alcohols, Acids, and Esters.

PubMed

Xie, Jia; Tian, Xiao-Fei; He, Song-Gui; Wei, Yun-Lu; Peng, Bin; Wu, Zhen-Qiang

2018-05-23

To investigate the effects of fusel alcohols on the intoxicating degree of liquor products, formulated liquors (FLs) were prepared by blending 1-propanol, isobutanol, and isoamyl alcohol with ethanol, organic acids, and corresponding ethyl esters to simulate the formula of traditional Chinese liquors. The prepared FLs were submitted for evaluation of their intoxicating degree (ID). The results showed that the fusel alcohols had a biphasic effect on the IDs of the FLs, depending on the comprehensive coordination of the characteristic minor components. The importance of the suitable ratio of alcohols/acids/esters (RAAE) on the IDs was also revealed. Under an optimal ratio level, the fusel alcohols exhibited negligible effects on the IDs of the FLs. Moreover, the ratio of isoamyl alcohol to isobutanol (IA/IB) showed a strong positive correlation to the IDs of the FLs. This study lays a foundation for the potential application in producing low-ID liquor.

Effect of alcohol on skin permeation and metabolism of an ester-type prodrug in Yucatan micropig skin.

PubMed

Fujii, Makiko; Ohara, Rieko; Matsumi, Azusa; Ohura, Kayoko; Koizumi, Naoya; Imai, Teruko; Watanabe, Yoshiteru

2017-11-15

We studied the effect that three alcohols, ethanol (EA), propanol (PA), and isopropanol (IPA), have on the skin permeation of p-hydroxy benzoic acid methyl ester (HBM), a model ester-type prodrug. HBM was applied to Yucatan micropig skin in a saturated phosphate buffered solution with or without 10% alcohol, and HBM and related materials in receptor fluid and skin were determined with HPLC. In the absence of alcohol, p-hydroxy benzoic acid (HBA), a metabolite of HBM, permeated the skin the most. The three alcohols enhanced the penetration of HBM at almost the same extent. The addition of 10% EA or PA to the HBM solution led to trans-esterification into the ethyl ester or propyl ester of HBA, and these esters permeated skin as well as HBA and HBM did. In contrast, the addition of 10% IPA promoted very little trans-esterification. Both hydrolysis and trans-esterification in the skin S9 fraction were inhibited by BNPP, an inhibitor of carboxylesterase (CES). Western blot and native PAGE showed the abundant expression of CES in micropig skin. Both hydrolysis and trans-esterification was simultaneously catalyzed by CES during skin permeation. Our data indicate that the alcohol used in dermal drug preparations should be selected not only for its ability to enhance the solubility and permeation of the drug, but also for the effect on metabolism of the drug in the skin. Copyright © 2017 Elsevier B.V. All rights reserved.

Yeast: the soul of beer's aroma--a review of flavour-active esters and higher alcohols produced by the brewing yeast.

PubMed

Pires, Eduardo J; Teixeira, José A; Brányik, Tomás; Vicente, António A

2014-03-01

Among the most important factors influencing beer quality is the presence of well-adjusted amounts of higher alcohols and esters. Thus, a heavy body of literature focuses on these substances and on the parameters influencing their production by the brewing yeast. Additionally, the complex metabolic pathways involved in their synthesis require special attention. More than a century of data, mainly in genetic and proteomic fields, has built up enough information to describe in detail each step in the pathway for the synthesis of higher alcohols and their esters, but there is still place for more. Higher alcohols are formed either by anabolism or catabolism (Ehrlich pathway) of amino acids. Esters are formed by enzymatic condensation of organic acids and alcohols. The current paper reviews the up-to-date knowledge in the pathways involving the synthesis of higher alcohols and esters by brewing yeasts. Fermentation parameters affecting yeast response during biosynthesis of these aromatic substances are also fully reviewed.

Alcohol, Aldehyde, and Ketone Liberation and Intracellular Cargo Release through Peroxide-Mediated α-Boryl Ether Fragmentation.

PubMed

Hanna, Ramsey D; Naro, Yuta; Deiters, Alexander; Floreancig, Paul E

2016-10-12

α-Boryl ethers, carbonates, and acetals, readily prepared from the corresponding alcohols that are accessed through ketone diboration, react rapidly with hydrogen peroxide to release alcohols, aldehydes, and ketones through the collapse of hemiacetal intermediates. Experiments with α-boryl acetals containing a latent fluorophore clearly demonstrate that cargo can be released inside cells in the presence of exogenous or endogenous hydrogen peroxide. These experiments show that this protocol can be used for drug activation in an oxidative environment without generating toxic byproducts.

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

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.7250 Polyaziridinyl ester of an aliphatic alcohol (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified...

The bifunctional alcohol and aldehyde dehydrogenase gene, adhE, is necessary for ethanol production in Clostridium thermocellum and Thermoanaerobacterium saccharolyticum.

PubMed

Lo, Jonathan; Zheng, Tianyong; Hon, Shuen; Olson, Daniel G; Lynd, Lee R

2015-04-01

Thermoanaerobacterium saccharolyticum and Clostridium thermocellum are anaerobic thermophilic bacteria being investigated for their ability to produce biofuels from plant biomass. The bifunctional alcohol and aldehyde dehydrogenase gene, adhE, is present in these bacteria and has been known to be important for ethanol formation in other anaerobic alcohol producers. This study explores the inactivation of the adhE gene in C. thermocellum and T. saccharolyticum. Deletion of adhE reduced ethanol production by >95% in both T. saccharolyticum and C. thermocellum, confirming that adhE is necessary for ethanol formation in both organisms. In both adhE deletion strains, fermentation products shifted from ethanol to lactate production and resulted in lower cell density and longer time to reach maximal cell density. In T. saccharolyticum, the adhE deletion strain lost >85% of alcohol dehydrogenase (ADH) activity. Aldehyde dehydrogenase (ALDH) activity did not appear to be affected, although ALDH activity was low in cell extracts. Adding ubiquinone-0 to the ALDH assay increased activity in the T. saccharolyticum parent strain but did not increase activity in the adhE deletion strain, suggesting that ALDH activity was inhibited. In C. thermocellum, the adhE deletion strain lost >90% of ALDH and ADH activity in cell extracts. The C. thermocellum adhE deletion strain contained a point mutation in the lactate dehydrogenase gene, which appears to deregulate its activation by fructose 1,6-bisphosphate, leading to constitutive activation of lactate dehydrogenase. Thermoanaerobacterium saccharolyticum and Clostridium thermocellum are bacteria that have been investigated for their ability to produce biofuels from plant biomass. They have been engineered to produce higher yields of ethanol, yet questions remain about the enzymes responsible for ethanol formation in these bacteria. The genomes of these bacteria encode multiple predicted aldehyde and alcohol dehydrogenases which could be

The effect of Maillard reaction products and yeast strain on the synthesis of key higher alcohols and esters in beer fermentations.

PubMed

Dack, Rachael E; Black, Gary W; Koutsidis, Georgios; Usher, St John

2017-10-01

The effect of Maillard reaction products (MRPs), formed during the production of dark malts, on the synthesis of higher alcohols and esters in beer fermentations was investigated by headspace solid-phase microextraction GC-MS. Higher alcohol levels were significantly (p<0.05) higher in dark malt fermentations, while the synthesis of esters was inhibited, due to possible suppression of enzyme activity and/or gene expression linked to ester synthesis. Yeast strain also affected flavour synthesis with Saccharomyces cerevisiae strain A01 producing considerably lower levels of higher alcohols and esters than S288c and L04. S288c produced approximately double the higher alcohol levels and around twenty times more esters compared to L04. Further investigations into malt type-yeast strain interactions in relation to flavour development are required to gain better understanding of flavour synthesis that could assist in the development of new products and reduce R&D costs for the industry. Copyright © 2017 Elsevier Ltd. All rights reserved.

AAV Gene Therapy for Alcoholism: Inhibition of Mitochondrial Aldehyde Dehydrogenase Enzyme Expression in Hepatoma Cells.

PubMed

Sanchez, Anamaria C; Li, Chengwen; Andrews, Barbara; Asenjo, Juan A; Samulski, R Jude

2017-09-01

Most ethanol is broken down in the liver in two steps by alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH2) enzymes, which metabolize down ethanol into acetaldehyde and then acetate. Some individuals from the Asian population who carry a mutation in the aldehyde dehydrogenase gene (ALDH2*2) cannot metabolize acetaldehyde as efficiently, producing strong effects, including facial flushing, dizziness, hypotension, and palpitations. This results in an aversion to alcohol intake and protection against alcoholism. The large prevalence of this mutation in the human population strongly suggests that modulation of ALDH2 expression by genetic technologies could result in a similar phenotype. scAAV2 vectors encoding ALDH2 small hairpin RNA (shRNA) were utilized to validate this hypothesis by silencing ALDH2 gene expression in human cell lines. Human cell lines HEK-293 and HepG2 were transduced with scAAV2/shRNA, showing a reduction in ALDH2 RNA and protein expression with the two viral concentration assayed (1 × 10 4 and 1 × 10 5 vg/cell) at two different time points. In both cell lines, ALDH2 RNA levels were reduced by 90% and protein expression was inhibited by 90% and 52%, respectively, 5 days post infection. Transduced HepG2 VL17A cells (ADH+) exposed to ethanol resulted in a 50% increase in acetaldehyde levels. These results suggest that gene therapy could be a useful tool for the treatment of alcoholism by knocking down ALDH2 expression using shRNA technology delivered by AAV vectors.

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...

The AAT1 locus is critical for the biosynthesis of esters contributing to 'ripe apple' flavour in 'Royal Gala' and 'Granny Smith' apples.

PubMed

Souleyre, Edwige J F; Chagné, David; Chen, Xiuyin; Tomes, Sumathi; Turner, Rebecca M; Wang, Mindy Y; Maddumage, Ratnasiri; Hunt, Martin B; Winz, Robert A; Wiedow, Claudia; Hamiaux, Cyril; Gardiner, Susan E; Rowan, Daryl D; Atkinson, Ross G

2014-06-01

The 'fruity' attributes of ripe apples (Malus × domestica) arise from our perception of a combination of volatile ester compounds. Phenotypic variability in ester production was investigated using a segregating population from a 'Royal Gala' (RG; high ester production) × 'Granny Smith' (GS; low ester production) cross, as well as in transgenic RG plants in which expression of the alcohol acyl transferase 1 (AAT1) gene was reduced. In the RG × GS population, 46 quantitative trait loci (QTLs) for the production of esters and alcohols were identified on 15 linkage groups (LGs). The major QTL for 35 individual compounds was positioned on LG2 and co-located with AAT1. Multiple AAT1 gene variants were identified in RG and GS, but only two (AAT1-RGa and AAT1-GSa) were functional. AAT1-RGa and AAT1-GSa were both highly expressed in the cortex and skin of ripe fruit, but AAT1 protein was observed mainly in the skin. Transgenic RG specifically reduced in AAT1 expression showed reduced levels of most key esters in ripe fruit. Differences in the ripe fruit aroma could be perceived by sensory analysis. The transgenic lines also showed altered ratios of biosynthetic precursor alcohols and aldehydes, and expression of a number of ester biosynthetic genes increased, presumably in response to the increased substrate pool. These results indicate that the AAT1 locus is critical for the biosynthesis of esters contributing to a 'ripe apple' flavour. © 2014 The Authors The Plant Journal © 2014 John Wiley & Sons Ltd.

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

PubMed

Pratihar, Sanjay

2016-03-14

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

Apple Aminoacid Profile and Yeast Strains in the Formation of Fusel Alcohols and Esters in Cider Production.

PubMed

Eleutério Dos Santos, Caroline Mongruel; Pietrowski, Giovana de Arruda Moura; Braga, Cíntia Maia; Rossi, Márcio José; Ninow, Jorge; Machado Dos Santos, Tâmisa Pires; Wosiacki, Gilvan; Jorge, Regina Maria Matos; Nogueira, Alessandro

2015-06-01

The amino acid profile in dessert apple must and its effect on the synthesis of fusel alcohols and esters in cider were established by instrumental analysis. The amino acid profile was performed in nine apple musts. Two apple musts with high (>150 mg/L) and low (<75 mg/L) nitrogen content, and four enological yeast strains, were used in cider fermentation. The aspartic acid, asparagine and glutamic acid amino acids were the majority in all the apple juices, representing 57.10% to 81.95%. These three amino acids provided a high consumption (>90%) during fermentation in all the ciders. Principal component analysis (PCA) explained 81.42% of data variability and the separation of three groups for the analyzed samples was verified. The ciders manufactured with low nitrogen content showed sluggish fermentation and around 50% less content of volatile compounds (independent of the yeast strain used), which were mainly 3-methyl-1-butanol (isoamyl alcohol) and esters. However, in the presence of amino acids (asparagine, aspartic acid, glutamic acid and alanine) there was a greater differentiation between the yeasts in the production of fusel alcohols and ethyl esters. High contents of these aminoacids in dessert apple musts are essential for the production of fusel alcohols and most of esters by aromatic yeasts during cider fermentation. © 2015 Institute of Food Technologists®

Low-alcohol Beers: Flavor Compounds, Defects, and Improvement Strategies.

PubMed

Blanco, Carlos A; Andrés-Iglesias, Cristina; Montero, Olimpio

2016-06-10

Beer consumers are accustomed to a product that offers a pleasant and well-defined taste. However, in alcohol-free and alcohol-reduced beers these characteristics are totally different from those in regular beer. Therefore, it is important to evaluate and determine the different flavor compounds that affect organoleptic characteristics to obtain a product that does not contain off-flavors, or taste of grass or wort. The taste defects in alcohol-free beer are mainly attributed to loss of aromatic esters, insufficient aldehydes, reduction or loss of different alcohols, and an indeterminate change in any of its compounds during the dealcoholization process. The dealcoholization processes that are commonly used to reduce the alcohol content in beer are shown, as well as the negative consequences of these processes to beer flavor. Possible strategies to circumvent such negative consequences are suggested.

Alcohol and aldehyde dehydrogenase gene polymorphisms influence susceptibility to esophageal cancer in Japanese alcoholics.

PubMed

Yokoyama, A; Muramatsu, T; Omori, T; Matsushita, S; Yoshimizu, H; Higuchi, S; Yokoyama, T; Maruyama, K; Ishii, H

1999-11-01

Studies have consistently demonstrated that inactive aldehyde dehydrogenase-2 (ALDH2), encoded by ALDH2*1/2*2, is closely associated with alcohol-related carcinogenesis. Recently, the contributions of alcohol dehydrogenase-2 (ADH2) polymorphism to alcoholism, esophageal cancer, and the flushing response have also been described. To determine the effects of ALDH2 and ADH2 genotypes in genetically based cancer susceptibility, lymphocyte DNA samples from 668 Japanese alcoholic men more than 40 years of age (91 with and 577 without esophageal cancer) were genotyped and the results were expressed as odds ratios (ORs). This study also tested 82 of the alcoholics with esophageal cancer to determine whether cancer susceptibility is associated with patients' responses to simple questions about current or former flushing after drinking a glass of beer. The frequencies of ADH2*1/2*1 and ALDH2*1/2*2 were significantly higher in alcoholics with, than in those without, esophageal cancer (0.473 vs. 0.289 and 0.560 vs. 0.099, respectively). After adjustment for drinking and smoking, the analysis showed significantly increased cancer risk for alcoholics with either ADH2*1/2*I (OR = 2.03) or ALDH2*1/2*2 (OR = 12.76). For those having ADH2*1/2*1 combined with ALDH2*1/2*2, the esophageal cancer risk was enhanced in a multiplicative fashion (OR = 27.66). Responses to flushing questions showed that only 47.8% of the ALDH2*1/2*2 heterozygotes with ADH2*1/ 2*1, compared with 92.3% of those with ALDH2*1/2*2 and the ADH2*2 allele, reported current or former flushing. Genotyping showed that for alcoholics who reported ever flushing, the questionnaire was 71.4% correct in identifying ALDH2*1/2*2 and 87.9% correct in identifying ALDH2*1/2*1. Japanese alcoholics can be divided into cancer susceptibility groups on the basis of their combined ADH2 and ALDH2 genotypes. The flushing questionnaire can predict high risk ALDH2*1/2*2 fairly accurately in persons with ADH2*2 allele, but a reliable

Chemoselective formation of unsymmetrically substituted ethers from catalytic reductive coupling of aldehydes and ketones with alcohols in aqueous solution.

PubMed

Kalutharage, Nishantha; Yi, Chae S

2015-04-03

A well-defined cationic Ru-H complex catalyzes reductive etherification of aldehydes and ketones with alcohols. The catalytic method employs environmentally benign water as the solvent and cheaply available molecular hydrogen as the reducing agent to afford unsymmetrical ethers in a highly chemoselective manner.

Fatty aldehyde dehydrogenases in Acinetobacter sp. strain HO1-N: role in hexadecanol metabolism.

PubMed Central

Singer, M E; Finnerty, W R

1985-01-01

The role of fatty aldehyde dehydrogenases (FALDHs) in hexadecane and hexadecanol metabolism was studied in Acinetobacter sp. strain HO1-N. Two distinct FALDHs were demonstrated in Acinetobacter sp. strain HO1-N: a membrane-bound, NADP-dependent FALDH activity induced 5-, 15-, and 9-fold by growth on hexadecanol, dodecyl aldehyde, and hexadecane, respectively, and a constitutive, NAD-dependent, membrane-localized FALDH. The NADP-dependent FALDH exhibited apparent Km and Vmax values for decyl aldehyde of 5.0, 13.0, 18.0, and 18.3 microM and 537.0, 500.0, 25.0, and 38.0 nmol/min in hexadecane-, hexadecanol-, ethanol-, palmitate-grown cells, respectively. FALDH isozymes ald-a, ald-b, and ald-c were demonstrated by gel electrophoresis in extracts of hexadecane- and hexadecanol-grown cells. ald-a, ald-b, and ald-d were present in dodecyl aldehyde-grown cells, while palmitate-grown control cells contained ald-b and ald-d. Dodecyl aldehyde-negative mutants were isolated and grouped into two phenotypic classes based on growth: class 1 mutants were hexadecane and hexadecanol negative and class 2 mutants were hexadecane and hexadecanol positive. Specific activity of NADP-dependent FALDH in Ald21 (class 1 mutant) was 85% lower than that of wild-type FALDH, while the specific activity of Ald24 (class 2 mutant) was 55% greater than that of wild-type FALDH. Ald21R, a dodecyl aldehyde-positive revertant able to grow on hexadecane, hexadecanol, and dodecyl aldehyde, exhibited a 100% increase in the specific activity of the NADP-dependent FALDH. The oxidation of [3H]hexadecane byAld21 yielded the accumulation of 61% more fatty aldehyde than the wild type, while Ald24 accumulated 27% more fatty aldehyde, 95% more fatty alcohol, and 65% more wax ester than the wild type. This study provides genetic and physiological evidence for the role of fatty aldehyde as an essential metabolic intermediate and NADP-dependent FALDH as a key enzyme in the dissimilation of hexadecane, hexadecanol

Acetate ester production by Chinese yellow rice wine yeast overexpressing the alcohol acetyltransferase-encoding gene ATF2.

PubMed

Zhang, J; Zhang, C; Qi, Y; Dai, L; Ma, H; Guo, X; Xiao, D

2014-11-27

Acetate ester, which are produced by fermenting yeast cells in an enzyme-catalyzed intracellular reaction, are responsible for the fruity character of fermented alcoholic beverages such as Chinese yellow rice wine. Alcohol acetyltransferase (AATase) is currently believed to be the key enzyme responsible for the production of acetate ester. In order to determine the precise role of the ATF2 gene in acetate ester production, an ATF2 gene encoding a type of AATase was overexpressed and the ability of the mutant to form acetate esters (including ethyl acetate, isoamyl acetate, and isobutyl acetate) was investigated. The results showed that after 5 days of fermentation, the concentrations of ethyl acetate, isoamyl acetate, and isobutyl acetate in yellow rice wines fermented with EY2 (pUC-PIA2K) increased to 137.79 mg/L (an approximate 4.9-fold increase relative to the parent cell RY1), 26.68 mg/L, and 7.60 mg/L, respectively. This study confirms that the ATF2 gene plays an important role in the production of acetate ester production during Chinese yellow rice wine fermentation, thereby offering prospects for the development of yellow rice wine yeast starter strains with optimized ester-producing capabilities.

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

2015-01-07

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.

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

Molecular characterization of the fatty alcohol oxidation pathway for wax-ester mobilization in germinated jojoba seeds

USDA-ARS?s Scientific Manuscript database

Jojoba (Simmondsia chinensis) is the only plant species known to use liquid wax esters (WE) as a primary seed storage reserve. Upon germination, WE hydrolysis releases very long-chain fatty alcohols, which must be oxidised to fatty acids by the sequential action of a fatty alcohol oxidase (FAO) and ...

Palladium-Catalyzed Anti-Markovnikov Oxidation of Allylic Amides to Protected β-Amino Aldehydes.

PubMed

Dong, Jia Jia; Harvey, Emma C; Fañanás-Mastral, Martín; Browne, Wesley R; Feringa, Ben L

2014-12-10

A general method for the preparation of N-protected β-amino aldehydes from allylic amines or linear allylic alcohols is described. Here the Pd(II)-catalyzed oxidation of N-protected allylic amines with benzoquinone is achieved in tBuOH under ambient conditions with excellent selectivity toward the anti-Markovnikov aldehyde products and full retention of configuration at the allylic carbon. The method shows a wide substrate scope and is tolerant of a range of protecting groups. Furthermore, β-amino aldehydes can be obtained directly from protected allylic alcohols via palladium-catalyzed autotandem reactions, and the application of this method to the synthesis of β-peptide aldehydes is described. From a mechanistic perspective, we demonstrate that tBuOH acts as a nucleophile in the reaction and that the initially formed tert-butyl ether undergoes spontaneous loss of isobutene to yield the aldehyde product. Furthermore, tBuOH can be used stoichiometrically, thereby broadening the solvent scope of the reaction. Primary and secondary alcohols do not undergo elimination, allowing the isolation of acetals, which subsequently can be hydrolyzed to their corresponding aldehyde products.

Synthesis of carboxylic acids, esters, alcohols and ethers containing a tetrahydropyran ring derived from 6-methyl-5-hepten-2-one.

PubMed

Hanzawa, Yohko; Hashimoto, Kahoko; Kasashima, Yoshio; Takahashi, Yoshiko; Mino, Takashi; Sakamoto, Masami; Fujita, Tsutomu

2012-01-01

3-hydroxy acids, 3-hydroxy-3,7-dimethyloct-6-enoic acid (1) and 3-hydroxy-2,2,3,7-tetramethyloct-6-enoic acid (2), were prepared from 6-methyl-5-hepten-2-one, and they were subsequently used to prepare (2,6,6-trimethyltetrahydropyran-2-yl)acetic acid (3) and 2-methyl-2-(2,6,6-trimethyltetrahydropyran-2-yl)propanoic acid (4), respectively, via cyclization with an acidic catalyst such as boron trifluoride diethyl etherate or iodine. The reaction of carboxylic acids 3 and 4 with alcohols, including methanol, ethanol, and 1-propanol, produced the corresponding methyl, ethyl, and propyl esters, which all contained a tetrahydropyran ring. Reduction of carboxylic acids 3 and 4 afforded the corresponding alcohols. Subsequent reactions of these alcohols with several acyl chlorides produced novel esters. The alcohols also reacted with methyl iodide and sodium hydride to provide novel ethers. A one-pot cyclization-esterification of 1 to produce esters containing a tetrahydropyran ring, using iodine as a catalyst, was also investigated.

Reductive Etherification of Fatty Acids or Esters with Alcohols using Molecular Hydrogen.

PubMed

Erb, Benjamin; Risto, Eugen; Wendling, Timo; Gooßen, Lukas J

2016-06-22

In the presence of a catalyst system consisting of a ruthenium/triphos complex and the Brønsted acid trifluoromethanesulfonimide, mixtures of fatty acids and aliphatic alcohols are converted into the corresponding ethers at 70 bar H2 . The protocol allows the sustainable one-step synthesis of valuable long-chain ether fragrances, lubricants, and surfactants from renewable sources. The reaction protocol is extended to various fatty acids and esters both in pure form and as mixtures, for example, tall oil acids or rapeseed methyl ester (RME). Even the mixed triglyceride rapeseed oil was converted in one step. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Preparation of novel alumina nanowire solid-phase microextraction fiber coating for ultra-selective determination of volatile esters and alcohols from complicated food samples.

PubMed

Zhang, Zhuomin; Ma, Yunjian; Wang, Qingtang; Chen, An; Pan, Zhuoyan; Li, Gongke

2013-05-17

A novel alumina nanowire (ANW) solid-phase microextraction (SPME) fiber coating was prepared by a simple and rapid anodization-chemical etching method for ultra-selective determination of volatile esters and alcohols from complicated food samples. Preparation conditions for ANW SPME fiber coating including corrosion solution concentration and corrosion time were optimized in detail for better surface morphology and higher surface area based on scanning electron microscope (SEM). Under the optimum conditions, homogeneous alumina nanowire structure of ANW SPME fiber coating was achieved with the average thickness of 20 μm around. Compared with most of commercial SPME fiber coatings, ANW SPME fiber coatings achieved the higher extraction capacity and special selectivity for volatile esters and alcohols. Finally, an efficient gas sampling technique based on ANW SPME fiber coating as the core was established and successfully applied for the ultra-selective determination of trace volatile esters and alcohols from complicated banana and fermented glutinous rice samples coupled with gas chromatography/mass spectrometry (GC/MS) detection. It was interesting that 25 esters and 2 alcohols among 30 banana volatile organic compounds (VOCs) identified and 4 esters and 7 alcohols among 13 identified VOCs of fermented glutinous rice were selectively sampled by ANW SPME fiber coatings. Furthermore, new analytical methods for the determination of some typical volatile esters and alcohols from banana and fermented glutinous rice samples at specific storage or brewing phases were developed and validated. Good recoveries for banana and fermented glutinous rice samples were achieved in range of 108-115% with relative standard deviations (RSDs) of 2.6-6.7% and 80.0-91.8% with RSDs of 0.3-1.3% (n=3), respectively. This work proposed a novel and efficient gas sampling technique of ANW SPME which was quite suitable for ultra-selectively sampling trace volatile esters and alcohols from

Kinetic study of the degradation of C5 and C6 unsaturated aldehydes and alcohols by ozone

NASA Astrophysics Data System (ADS)

Kalalian, Carmen; Roth, Estelle; Chakir, Abdelkhaleq

2017-04-01

Emissions of biogenic volatile organic compounds (VOCs) are higher than those from anthropogenic sources. They are therefore likely to have a great influence on atmospheric chemistry both locally and regionally, through their impact on the HOx balance (HOx = HO + HO2), ozone production and ability to form secondary organic aerosols (SOA). Among the volatile organic compounds of biogenic origin are the family of C5 and C6 unsaturated aldehydes and alcohols. Few information exist regarding the fate of these compounds in the atmosphere especially there reaction with ozone. In this work, we studied the kinetics of the reaction of three unsaturated aldehydes (trans-2-pentenal, trans-2-hexenal and 2-methyl-2-pentenal) and three unsaturated alcohols (1-penten-3-ol, cis-2-penten-1-ol and trans-3-hexen-1-ol) with ozone O3 in a rigid atmospheric simulation chamber coupled to an FTIR spectrometer at four different temperatures (273, 298, 333 and 353 K) and at atmospheric pressure. The rate constants of the ozonolysis reaction of the unsaturated aldehydes and the unsaturated alcohols studied were determined and the following Arrhenius expression was obtained (cm3 molecule -1 s -1): k (Trans -2-pentenal)= (3.83 ± 3.71) x 10-16 exp (- (1706 ± 295) / T) k (Trans-2-hexenal)= (1.43 ± 0.67) x 10-16 exp (- (1369 ± 141) / T) k(2-Methyl-2-pentenal)= (3.62± 0.22) x 10-18 exp (- (121 ± 20) / T) k(1-penten-3-ol) = (1.42 ± 1.24) x 10-16 exp (- (642 ± 250) / T) k(Cis-2-penten-1-ol)= (3.14 ± 0.45) x 10-15 exp (- (1045 ± 40) / T) k(Trans-3-hexen-1-ol)= (6.38 ± 1.75) x 10-16 exp (- (686 ± 89) / T) The obtained data will be discussed in terms of structure-reactivity relationship and compared with the reported reactivity with OH radicals. The atmospheric implications derived from this study are discussed as well.

Selective reduction of carboxylic acids to aldehydes with hydrosilane via photoredox catalysis.

PubMed

Zhang, Muliang; Li, Nan; Tao, Xingyu; Ruzi, Rehanguli; Yu, Shouyun; Zhu, Chengjian

2017-09-12

The direct reduction of carboxylic acids to aldehydes with hydrosilane was achieved through visible light photoredox catalysis. The combination of both single electron transfer and hydrogen atom transfer steps offers a novel and convenient approach to selective reduction of carboxylic acids to aldehydes. The method also features mild conditions, high yields, broad substrate scope, and good functional group tolerance, such as alkyne, ester, ketone, amide and amine groups.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Karakalos, Stavros; Zugic, Branko; Stowers, Kara J.

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

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

DOE PAGES

Karakalos, Stavros; Zugic, Branko; Stowers, Kara J.; ...

2016-03-18

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

Japan Flavour and Fragrance Materials Association's (JFFMA) safety assessment of food-flavouring substances uniquely used in Japan that belong to the class of aliphatic primary alcohols, aldehydes, carboxylic acids, acetals and esters containing additional oxygenated functional groups.

PubMed

Saito, Kenji; Hasegawa-Baba, Yasuko; Sekiya, Fumiko; Hayashi, Shim-Mo; Mirokuji, Yoshiharu; Okamura, Hiroyuki; Maruyama, Shinpei; Ono, Atsushi; Nakajima, Madoka; Degawa, Masakuni; Ozawa, Shogo; Shibutani, Makoto; Maitani, Tamio

2017-09-01

We performed a safety evaluation using the procedure devised by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) of the following four flavouring substances that belong to the class of 'aliphatic primary alcohols, aldehydes, carboxylic acids, acetals, and esters containing additional oxygenated functional groups' and are uniquely used in Japan: butyl butyrylacetate, ethyl 2-hydroxy-4-methylpentanoate, 3-hydroxyhexanoic acid and methyl hydroxyacetate. Although no genotoxicity study data were found in the published literature, none of the four substances had chemical structural alerts predicting genotoxicity. All four substances were categorised as class I by using Cramer's classification. The estimated daily intake of each of the four substances was determined to be 0.007-2.9 μg/person/day by using the maximised survey-derived intake method and based on the annual production data in Japan in 2001, 2005 and 2010, and was determined to be 0.250-600.0 μg/person/day by using the single-portion exposure technique and based on average-use levels in standard portion sizes of flavoured foods. Both of these estimated daily intake ranges were below the threshold of toxicological concern for class I substances, which is 1800 μg/person/day. Although no information from in vitro and in vivo toxicity studies for the four substances was available, these substances were judged to raise no safety concerns at the current levels of intake.

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.

Substrate specificity and subcellular localization of the aldehyde-alcohol redox-coupling reaction in carp cones.

PubMed

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

2013-12-20

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.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ide, Matthew S.; Hao, Bing; Neurock, Matthew

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. Althoughmore » 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.« less

[Distribution of genotypes of alcohol dehydrogenase 2 and aldehyde dehydrogenase 2 in Japanese twin children].

PubMed

Qu, W; Yamagata, Z; Wu, D; Zhang, B; Zhang, Y

1999-03-01

In order to prevent alcohol related deseases, this study investigated the distribution of the genes controlling alcohol metabolism in Japan's twin. Restriction fragment length polymorphism-polymerase chain reaction (RFLP-PCR) technique was used to measure the control gene of alcohol metabolized enzymes and the genotypes of alcohol dehydrogenase 2 (ADH2) and aldehyde dehydrogenase 2 (ALDH2), which were distributed in Japan's twins. At the same time, according to the difference in genotypes, the sensitive individuals were screened from the study subjects. The distribution of ADH2 and ALDH2 genes were consistent with the Hardy-weinberg equation. The three genotypes of ADH2 gene were ADH2(1)/ADH2(1) (1.1%), ADH2(1)/ADH2(2) (44.6%) and ADH2(2)/ADH2(2) (54.3%). And those of ALDH2 gene were ALDH2(1)/ALDH2(1) (41.3%), ALDH2(1)/ALDH2(2) (39.1%) and ALDH2(2)/ALDH2(2) (19.6%). The frequency of ADH2 and ALDH2 genes was 0.255, 0.745 and 0.609, 0.391 respectively. Not only the distribution of genotypes of ADH2 and ALDH2 is known, but also the sensitive individuals are found, which can help prevent alcohol related disease.

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

USDA-ARS?s Scientific Manuscript database

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...

Saccharomyces kudriavzevii and Saccharomyces uvarum differ from Saccharomyces cerevisiae during the production of aroma-active higher alcohols and acetate esters using their amino acidic precursors.

PubMed

Stribny, Jiri; Gamero, Amparo; Pérez-Torrado, Roberto; Querol, Amparo

2015-07-16

Higher alcohols and acetate esters are important flavour and aroma components in the food industry. In alcoholic beverages these compounds are produced by yeast during fermentation. Although Saccharomyces cerevisiae is one of the most extensively used species, other species of the Saccharomyces genus have become common in fermentation processes. This study analyses and compares the production of higher alcohols and acetate esters from their amino acidic precursors in three Saccharomyces species: Saccharomyces kudriavzevii, Saccharomyces uvarum and S. cerevisiae. The global volatile compound analysis revealed that S. kudriavzevii produced large amounts of higher alcohols, whereas S. uvarum excelled in the production of acetate esters. Particularly from phenylalanine, S. uvarum produced the largest amounts of 2-phenylethyl acetate, while S. kudriavzevii obtained the greatest 2-phenylethanol formation from this precursor. The present data indicate differences in the amino acid metabolism and subsequent production of flavour-active higher alcohols and acetate esters among the closely related Saccharomyces species. This knowledge will prove useful for developing new enhanced processes in fragrance, flavour, and food industries. Copyright © 2015. Published by Elsevier B.V.

Methods of making organic compounds by metathesis

DOEpatents

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

2015-09-01

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

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.

One-Pot Synthesis of N-Substituted β-Amino Alcohols from Aldehydes and Isocyanides.

PubMed

Cioc, Răzvan C; van der Niet, Daan J H; Janssen, Elwin; Ruijter, Eelco; Orru, Romano V A

2015-05-18

A practical two-stage one-pot synthesis of N-substituted β-amino alcohols using aldehydes and isocyanides as starting materials has been developed. This method features mild reaction conditions, broad scope, and general tolerance of functional groups. Based on a less common central carbon-carbon bond disconnection, this protocol complements traditional approaches that involve amines and various carbon electrophiles (epoxides, α-halo ketones, β-halohydrins). Medicinally relevant products can be prepared in a concise and efficient way from simple building blocks, as demonstrated in the synthesis of the antiasthma drug salbutamol. Upgrading the synthesis to an enantioselective variant is also feasible. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Catalytic Nucleophilic Glyoxylation of Aldehydes

PubMed Central

Steward, Kimberly M.; Johnson, Jeffrey S.

2010-01-01

β-Silyloxy-α-ketoesters are prepared through a cyanide-catalyzed benzoin-type reaction with silyl glyoxylates and aldehydes. The products undergo a dynamic kinetic resolution to provide enantioenriched orthogonally protected alcohols and can be converted to the corresponding β-silyloxy-α-aminoesters. PMID:20481613

Molecular Structure and Reactivity in the Pyrolysis of Aldehydes

NASA Astrophysics Data System (ADS)

Sias, Eric; Cole, Sarah; Sowards, John; Warner, Brian; Wright, Emily; McCunn, Laura R.

2016-06-01

The effect of alkyl chain structure on pyrolysis mechanisms has been investigated in a series of aldehydes. Isovaleraldehyde, CH_3CH(CH_3)CH_2CHO, and pivaldehyde, (CH_3)_3CCHO, were subject to thermal decomposition in a resistively heated SiC tubular reactor at 800-1200 °C. Matrix-isolation FTIR spectroscopy was used to identify pyrolysis products. Carbon monoxide and isobutene were major products from each of the aldehydes, which is consistent with what is known from previous studies of unbranched alkyl-chain aldehydes. Other products observed include vinyl alcohol, propene, acetylene, and ethylene, revealing complexities to be considered in the pyrolysis of large, branched-chain aldehydes.

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

NASA Astrophysics Data System (ADS)

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

2014-02-01

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

Measurement uncertainty of ester number, acid number and patchouli alcohol of patchouli oil produced in Yogyakarta

NASA Astrophysics Data System (ADS)

Istiningrum, Reni Banowati; Saepuloh, Azis; Jannah, Wirdatul; Aji, Didit Waskito

2017-03-01

Yogyakarta is one of patchouli oil distillation center in Indonesia. The quality of patchouli oil greatly affect its market price. Therefore, testing quality of patchouli oil parameters is an important concern, one through determination of the measurement uncertainty. This study will determine the measurement uncertainty of ester number, acid number and content of patchouli alcohol through a bottom up approach. Source contributor to measurement uncertainty of ester number is a mass of the sample, a blank and sample titration volume, the molar mass of KOH, HCl normality, and replication. While the source contributor of the measurement uncertainty of acid number is the mass of the sample, the sample titration volume, the relative mass and normality of KOH, and repetition. Determination of patchouli alcohol by Gas Chromatography considers the sources of measurement uncertainty only from repeatability because reference materials are not available.

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

Chemical and physical analyses of wax ester properties

PubMed Central

Patel, Sejal; Nelson, Dennis R.; Gibbs, Allen G.

2001-01-01

Wax esters are major constituents of the surface lipids in many terrestrial arthropods, but their study is complicated by their diversity. We developed a procedure for quantifying isomers in mixtures of straight-chain saturated and unsaturated wax esters having the same molecular weights, using single-ion monitoring of the total ion current data from gas chromatography-mass spectrometry. We examined the biological consequences of structural differences by measuring the melting temperatures, Tm, of >60 synthetic wax esters, containing 26–48 carbon atoms. Compounds containing saturated alcohol and acid moieties melted at 38–73°C. The main factor affecting Tm was the total chain length of the wax ester, but the placement of the ester bond also affected Tm. Insertion of a double bond into either the alcohol or acid moiety decreased Tm by ∼30°C. Simple mixtures of wax esters with n-alkanes melted several °C lower than predicted from the melting points of the component lipids. Our results indicate that the wax esters of primary alcohols that are most typically found on the cuticle of terrestrial arthropods occur in a solid state under physiological conditions, thereby conferring greater waterproofing. Wax esters of secondary alcohols, which occur on melanopline grasshoppers, melted >60°C below primary esters of the same molecular weight and reduced Tm of the total surface lipids to environmental values. PMID:15455064

Synthesis of fruity ethyl esters by acyl coenzyme A: alcohol acyltransferase and reverse esterase activities in Oenococcus oeni and Lactobacillus plantarum.

PubMed

Costello, P J; Siebert, T E; Solomon, M R; Bartowsky, E J

2013-03-01

To assess the abilities of commercial wine lactic acid bacteria (LAB) to synthesize potentially flavour active fatty acid ethyl esters and determine mechanisms involved in their production. Oenococcus oeni AWRI B551 produced significant levels of ethyl hexanoate and ethyl octanoate following growth in an ethanolic test medium, and ester formation generally increased with increasing pH (4.5 > 3.5), anaerobiosis and precursor supplementation. Cell-free extracts of commercial O. oeni strains and Lactobacillus plantarum AWRI B740 were also tested for ester-synthesizing capabilities in a phosphate buffer via: (i) acyl coenzyme A: alcohol acyltransferase (AcoAAAT) activity and (ii) reverse esterase activity. For both ester-synthesizing activities, strain-dependent variation was observed, with AcoAAAT activity generally greater than reverse esterase. Reverse esterase in O. oeni AWRI B551 also esterified 1-propanol to produce propyl octanoate, and deuterated substrates ([(2)H(6)]ethanol and [(2)H(15)]octanoic acid) to produce the fully deuterated ester, [(2)H(5)]ethyl [(2)H(15)]octanoate. Wine LAB exhibit ethyl ester-synthesizing capability and possess two different ester-synthesizing activities, one of which is associated with an acyl coenzyme A: alcohol acyltransferase. This study demonstrates that wine LAB exhibit enzyme activities that can augment the ethyl ester content of wine. This knowledge will facilitate greater control over the impacts of malolactic fermentation on the fruity sensory properties and quality of wine. © 2012 Australian Wine Research Institute © 2012 The Society for Applied Microbiology.

Characterization of volatile compounds of Mezcal, an ethnic alcoholic beverage obtained from Agave salmiana.

PubMed

De León-Rodríguez, Antonio; González-Hernández, Lidia; Barba de la Rosa, Ana P; Escalante-Minakata, Pilar; López, Mercedes G

2006-02-22

Commercial mezcals (white, white with worm, rested, rested with worm, and aged) produced from Agave salmiana were analyzed by solid-phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS). Thirty-seven compounds were identified, and nine of them were classified as major compounds of mezcal (MCM). Saturated alcohols, ethyl acetate, ethyl 2-hydroxypropanoate, and acetic acid form the MCM group. Minor compounds of mezcal group include other alcohols, aldehydes, ketones, large chain ethyl esters, organic acids, furans, terpenes, alkenes, and alkynes. Most of the compounds found in mezcals in this study are similar to those present in tequilas and other alcoholic beverages. However, mezcals contain unique compounds such as limonene and pentyl butanoate, which can be used as markers for the authenticity of mezcal produced from A. salmiana.

Alcohol acyl transferase 1 links two distinct volatile pathways that produce esters and phenylpropenes in apple fruit.

PubMed

Yauk, Yar-Khing; Souleyre, Edwige J F; Matich, Adam J; Chen, Xiuyin; Wang, Mindy Y; Plunkett, Blue; Dare, Andrew P; Espley, Richard V; Tomes, Sumathi; Chagné, David; Atkinson, Ross G

2017-07-01

Fruit accumulate a diverse set of volatiles including esters and phenylpropenes. Volatile esters are synthesised via fatty acid degradation or from amino acid precursors, with the final step being catalysed by alcohol acyl transferases (AATs). Phenylpropenes are produced as a side branch of the general phenylpropanoid pathway. Major quantitative trait loci (QTLs) on apple (Malus × domestica) linkage group (LG)2 for production of the phenylpropene estragole and volatile esters (including 2-methylbutyl acetate and hexyl acetate) both co-located with the MdAAT1 gene. MdAAT1 has previously been shown to be required for volatile ester production in apple (Plant J., 2014, https://doi.org/10.1111/tpj.12518), and here we show it is also required to produce p-hydroxycinnamyl acetates that serve as substrates for a bifunctional chavicol/eugenol synthase (MdoPhR5) in ripe apple fruit. Fruit from transgenic 'Royal Gala' MdAAT1 knockdown lines produced significantly reduced phenylpropene levels, whilst manipulation of the phenylpropanoid pathway using MdCHS (chalcone synthase) knockout and MdMYB10 over-expression lines increased phenylpropene production. Transient expression of MdAAT1, MdoPhR5 and MdoOMT1 (O-methyltransferase) genes reconstituted the apple pathway to estragole production in tobacco. AATs from ripe strawberry (SAAT1) and tomato (SlAAT1) fruit can also utilise p-coumaryl and coniferyl alcohols, indicating that ripening-related AATs are likely to link volatile ester and phenylpropene production in many different fruit. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

Asymmetric functional organozinc additions to aldehydes catalyzed by 1,1'-bi-2-naphthols (BINOLs).

PubMed

Pu, Lin

2014-05-20

Chiral alcohols are ubiquitous in organic structures. One efficient method to generate chiral alcohols is the catalytic asymmetric addition of a carbon nucleophile to a carbonyl compound since this process produces a C-C bond and a chiral center simultaneously. In comparison with the carbon nucleophiles such as an organolithium or a Grignard reagent, an organozinc reagent possesses the advantages of functional group tolerance and more mild reaction conditions. Catalytic asymmetric reactions of aldehydes with arylzincs, vinylzincs, and alkynylzincs to generate functional chiral alcohols are discussed in this Account. Our laboratory has developed a series of 1,1'-bi-2-naphthol (BINOL)-based chiral catalysts for the asymmetric organozinc addition to aldehydes. It is found that the 3,3'-dianisyl-substituted BINOLs are not only highly enantioselective for the alkylzinc addition to aldehydes, but also highly enantioselective for the diphenylzinc addition to aldehydes. A one-step synthesis has been achieved to incorporate Lewis basic amine groups into the 3,3'-positions of the partially hydrogenated H8BINOL. These H8BINOL-amine compounds have become more generally enantioselective and efficient catalysts for the diphenylzinc addition to aldehydes to produce various types of chiral benzylic alcohols. The application of the H8BINOL-amine catalysts is expanded by using in situ generated diarylzinc reagents from the reaction of aryl iodides with ZnEt2, which still gives high enantioselectivity and good catalytic activity. Such a H8BINOL-amine compound is further found to catalyze the highly enantioselective addition of vinylzincs, in situ generated from the treatment of vinyl iodides with ZnEt2, to aldehydes to give the synthetically very useful chiral allylic alcohols. We have discovered that the unfunctionalized BINOL in combination with ZnEt2 and Ti(O(i)Pr)4 can catalyze the terminal alkyne addition to aldehydes to produce chiral propargylic alcohols of high synthetic

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

Dynamic kinetic asymmetric cross-benzoin additions of β-stereogenic α-keto esters.

PubMed

Goodman, C Guy; Johnson, Jeffrey S

2014-10-22

The dynamic kinetic resolution of β-halo α-keto esters via an asymmetric cross-benzoin reaction is described. A chiral N-heterocyclic carbene catalyzes the umpolung addition of aldehydes to racemic α-keto esters. The resulting fully substituted β-halo glycolic ester products are obtained with high levels of enantio- and diastereocontrol. The high chemoselectivity observed is a result of greater electrophilicity of the α-keto ester toward the Breslow intermediate. The reaction products are shown to undergo highly diastereoselective substrate-controlled reduction to give highly functionalized stereotriads.

Dynamic Kinetic Asymmetric Cross-Benzoin Additions of β-Stereogenic α-Keto Esters

PubMed Central

2015-01-01

The dynamic kinetic resolution of β-halo α-keto esters via an asymmetric cross-benzoin reaction is described. A chiral N-heterocyclic carbene catalyzes the umpolung addition of aldehydes to racemic α-keto esters. The resulting fully substituted β-halo glycolic ester products are obtained with high levels of enantio- and diastereocontrol. The high chemoselectivity observed is a result of greater electrophilicity of the α-keto ester toward the Breslow intermediate. The reaction products are shown to undergo highly diastereoselective substrate-controlled reduction to give highly functionalized stereotriads. PMID:25299730

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

USDA-ARS?s Scientific Manuscript database

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...

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

2016-06-20

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.

Inhibition of human alcohol and aldehyde dehydrogenases by cimetidine and assessment of its effects on ethanol metabolism.

PubMed

Lai, Ching-Long; Li, Yeung-Pin; Liu, Chiu-Ming; Hsieh, Hsiu-Shan; Yin, Shih-Jiun

2013-02-25

Previous studies have reported that cimetidine, an H2-receptor antagonist used to treat gastric and duodenal ulcers, can inhibit alcohol dehydrogenases (ADHs) and ethanol metabolism. Human alcohol dehydrogenases and aldehyde dehydrogenases (ALDHs), the 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 by cimetidine of alcohol oxidation by recombinant human ADH1A, ADH1B1, ADH1B2, ADH1B3, ADH1C1, ADH1C2, ADH2, and ADH4, and aldehyde oxidation by ALDH1A1 and ALDH2 at pH 7.5 and a cytosolic NAD(+) concentration. Cimetidine acted as competitive or noncompetitive inhibitors for the ADH and ALDH isozymes/allozymes with near mM inhibition constants. The metabolic interactions between cimetidine and ethanol/acetaldehyde were assessed by computer simulation using the inhibition equations and the determined kinetic constants. At therapeutic drug levels (0.015 mM) and physiologically relevant concentrations of ethanol (10 mM) and acetaldehyde (10 μM) in target tissues, cimetidine could weakly inhibit (<5%) the activities of ADH1B2 and ADH1B3 in liver, ADH2 in liver and small intestine, ADH4 in stomach, and ALDH1A1 in the three tissues, but not significantly affect ADH1A, ADH1B1, ADH1C1/2, or ALDH2. At higher drug levels, which may accumulate in cells (0.2 mM), the activities of the weakly-inhibited enzymes may be decreased more significantly. The quantitative effects of cimetidine on metabolism of ethanol and other physiological substrates of ADHs need further investigation. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Semi-catalytic reduction of secondary amides to imines and aldehydes.

PubMed

Lee, Sun-Hwa; Nikonov, Georgii I

2014-06-21

Secondary amides can be reduced by silane HSiMe2Ph into imines and aldehydes by a two-stage process involving prior conversion of amides into iminoyl chlorides followed by catalytic reduction mediated by the ruthenium complex [Cp(i-Pr3P)Ru(NCCH3)2]PF6 (1). Alkyl and aryl amides bearing halogen, ketone, and ester groups were converted with moderate to good yields under mild reaction conditions to the corresponding imines and aldehydes. This procedure does not work for substrates bearing the nitro-group and fails for heteroaromatic amides. In the case of cyano substituted amides, the cyano group is reduced to imine.

The Activity of Class I-IV Alcohol Dehydrogenase Isoenzymes and Aldehyde Dehydrogenase in Bladder Cancer Cells.

PubMed

Orywal, Karolina; Jelski, Wojciech; Werel, Tadeusz; Szmitkowski, Maciej

2018-01-02

The aim of this study was to determine the differences in the activity of Alcohol Dehydrogenase (ADH) isoenzymes and Aldehyde Dehydrogenase (ALDH) in normal and cancerous bladder cells. Class III, IV of ADH and total ADH activity were measured by the photometric method and class I, II ADH and ALDH activity by the fluorometric method. Significantly higher total activity of ADH was found in both, low-grade and high-grade bladder cancer, in comparison to healthy tissues. The increased activity of total ADH in bladder cancer cells may be the cause of metabolic disorders in cancer cells, which may intensify carcinogenesis.

N-Heterocyclic carbene-catalyzed direct cross-aza-benzoin reaction: Efficient synthesis of α-amino-β-keto esters.

PubMed

Uno, Takuya; Kobayashi, Yusuke; Takemoto, Yoshiji

2012-01-01

An efficient catalytic synthesis of α-amino-β-keto esters has been newly developed. Cross-coupling of various aldehydes with α-imino ester, catalyzed by N-heterocyclic carbene, leads chemoselectively to α-amino-β-keto esters in moderate to good yields with high atom efficiency. The reaction mechanism is discussed, and it is proposed that the α-amino-β-keto esters are formed under thermodynamic control.

Five Fatty Aldehyde Dehydrogenase Enzymes from Marinobacter and Acinetobacter spp. and Structural Insights into the Aldehyde Binding Pocket

PubMed Central

Bertram, Jonathan H.; Mulliner, Kalene M.; Shi, Ke; Plunkett, Mary H.; Nixon, Peter; Serratore, Nicholas A.; Douglas, Christopher J.; Aihara, Hideki

2017-01-01

ABSTRACT Enzymes involved in lipid biosynthesis and metabolism play an important role in energy conversion and storage and in the function of structural components such as cell membranes. The fatty aldehyde dehydrogenase (FAldDH) plays a central function in the metabolism of lipid intermediates, oxidizing fatty aldehydes to the corresponding fatty acid and competing with pathways that would further reduce the fatty aldehydes to fatty alcohols or require the fatty aldehydes to produce alkanes. In this report, the genes for four putative FAldDH enzymes from Marinobacter aquaeolei VT8 and an additional enzyme from Acinetobacter baylyi were heterologously expressed in Escherichia coli and shown to display FAldDH activity. Five enzymes (Maqu_0438, Maqu_3316, Maqu_3410, Maqu_3572, and the enzyme reported under RefSeq accession no. WP_004927398) were found to act on aldehydes ranging from acetaldehyde to hexadecanal and also acted on the unsaturated long-chain palmitoleyl and oleyl aldehydes. A comparison of the specificities of these enzymes with various aldehydes is presented. Crystallization trials yielded diffraction-quality crystals of one particular FAldDH (Maqu_3316) from M. aquaeolei VT8. Crystals were independently treated with both the NAD+ cofactor and the aldehyde substrate decanal, revealing specific details of the likely substrate binding pocket for this class of enzymes. A likely model for how catalysis by the enzyme is accomplished is also provided. IMPORTANCE This study provides a comparison of multiple enzymes with the ability to oxidize fatty aldehydes to fatty acids and provides a likely picture of how the fatty aldehyde and NAD+ are bound to the enzyme to facilitate catalysis. Based on the information obtained from this structural analysis and comparisons of specificities for the five enzymes that were characterized, correlations to the potential roles played by specific residues within the structure may be drawn. PMID:28389542

Five Fatty Aldehyde Dehydrogenase Enzymes from Marinobacter and Acinetobacter spp. and Structural Insights into the Aldehyde Binding Pocket

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bertram, Jonathan H.; Mulliner, Kalene M.; Shi, Ke

ABSTRACT Enzymes involved in lipid biosynthesis and metabolism play an important role in energy conversion and storage and in the function of structural components such as cell membranes. The fatty aldehyde dehydrogenase (FAldDH) plays a central function in the metabolism of lipid intermediates, oxidizing fatty aldehydes to the corresponding fatty acid and competing with pathways that would further reduce the fatty aldehydes to fatty alcohols or require the fatty aldehydes to produce alkanes. In this report, the genes for four putative FAldDH enzymes fromMarinobacter aquaeoleiVT8 and an additional enzyme fromAcinetobacter baylyiwere heterologously expressed inEscherichia coliand shown to display FAldDH activity.more » Five enzymes (Maqu_0438, Maqu_3316, Maqu_3410, Maqu_3572, and the enzyme reported under RefSeq accession no.WP_004927398) were found to act on aldehydes ranging from acetaldehyde to hexadecanal and also acted on the unsaturated long-chain palmitoleyl and oleyl aldehydes. A comparison of the specificities of these enzymes with various aldehydes is presented. Crystallization trials yielded diffraction-quality crystals of one particular FAldDH (Maqu_3316) fromM. aquaeoleiVT8. Crystals were independently treated with both the NAD +cofactor and the aldehyde substrate decanal, revealing specific details of the likely substrate binding pocket for this class of enzymes. A likely model for how catalysis by the enzyme is accomplished is also provided. IMPORTANCEThis study provides a comparison of multiple enzymes with the ability to oxidize fatty aldehydes to fatty acids and provides a likely picture of how the fatty aldehyde and NAD +are bound to the enzyme to facilitate catalysis. Based on the information obtained from this structural analysis and comparisons of specificities for the five enzymes that were characterized, correlations to the potential roles played by specific residues within the structure may be drawn.« less

Salivary aldehyde dehydrogenase - temporal and population variability, correlations with drinking and smoking habits and activity towards aldehydes contained in food.

PubMed

Giebułtowicz, Joanna; Dziadek, Marta; Wroczyński, Piotr; Woźnicka, Katarzyna; Wojno, Barbara; Pietrzak, Monika; Wierzchowski, Jacek

2010-01-01

Fluorimetric method based on oxidation of the fluorogenic 6-methoxy-2-naphthaldehyde was applied to evaluate temporal and population variability of the specific activity of salivary aldehyde dehydrogenase (ALDH) and the degree of its inactivation in healthy human population. Analyzed was also its dependence on drinking and smoking habits, coffee consumption, and its sensitivity to N-acetylcysteine. Both the specific activity of salivary ALDH and the degree of its inactivation were highly variable during the day, with the highest activities recorded in the morning hours. The activities were also highly variable both intra- and interpersonally, and negatively correlated with age, and this correlation was stronger for the subgroup of volunteers declaring abstinence from alcohol and tobacco. Moderately positive correlations of salivary ALDH specific activity with alcohol consumption and tobacco smoking were also recorded (r(s) ~0.27; p=0.004 and r(s) =0.30; p=0.001, respectively). Moderate coffee consumption correlated positively with the inactivation of salivary ALDH, particularly in the subgroup of non-drinking and non-smoking volunteers. It was found that mechanical stimulation of the saliva flow increases the specific activity of salivary ALDH. The specific activity of the salivary ALDH was strongly and positively correlated with that of superoxide dismutase, and somewhat less with salivary peroxidase. The antioxidant-containing drug N-acetylcysteine increased activity of salivary ALDH presumably by preventing its inactivation in the oral cavity. Some food-related aldehydes, mainly cinnamic aldehyde and anisaldehyde, were excellent substrates of the salivary ALDH3A1 enzyme, while alkenals, particularly those with short chain, were characterized by lower affinity towards this enzyme but high catalytic constants. The protective role of salivary ALDH against aldehydes in food and those found in the cigarette smoke is discussed, as well as its participation in

STIMULATION OF TARSAL RECEPTORS OF THE BLOWFLY BY ALIPHATIC ALDEHYDES AND KETONES

PubMed Central

Chadwick, L. E.; Dethier, V. G.

1949-01-01

Rejection of eight aldehydes, eight ketones, five secondary alcohols, and 3-pentanol has been studied in the blowfly Phormia regina Meigen. The data agree with results previously reported for normal alcohols and several series of glycols in showing a logarithmic increase in stimulating effect with increasing chain length. The order of increasing effectiveness among the different species of compounds thus far investigated is the following: polyglycols, diols, secondary alcohols, iso-alcohols, normal alcohols, ketones, iso-aldehydes, normal aldehydes. Curves relating the logarithms of threshold concentration to the logarithms of chain length for diols, alcohols, aldehydes, and ketones show inflections in the 3 to 6 carbon range. Above and below the region of inflection the curves are nearly rectilinear. The slopes for the upper limbs (smaller molecules) are of the order of –2; for the lower limbs, about –10. Comparisons of the threshold data with numerical values for molecular weights, molecular areas and volumes, oil-water distribution coefficients, activity coefficients, standard free energies, vapor pressures, boiling points, melting points, dipole moments, dielectric constants, and degree of association are discussed briefly, and it is concluded that none of the comparisons serves to bring the data from the several series and from the two portions of each series into a single homogeneous system. A qualitative comparison with water solubilities shows fewer discrepancies. It is suggested that the existence of a combination of aqueous and lipoid phases at the receptor surface would fit best with what is presently known about the relationship between chemical structure and stimulating effect in contact chemoreception. In this hypothesis the smaller and more highly water-soluble compounds are envisaged as gaining access to the receptors partly through the aqueous phase, the larger molecules predominantly through the lipoid phase. PMID:18114559

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.

Alcohol and aldehyde dehydrogenase gene polymorphisms and oropharyngolaryngeal, esophageal and stomach cancers in Japanese alcoholics.

PubMed

Yokoyama, A; Muramatsu, T; Omori, T; Yokoyama, T; Matsushita, S; Higuchi, S; Maruyama, K; Ishii, H

2001-03-01

Alcohol dehydrogenase-2 (ADH2) and aldehyde dehydrogenase-2 (ALDH2) gene polymorphisms play roles in ethanol metabolism, drinking behavior and esophageal carcinogenesis in Japanese; however, the combined influence of ADH2 and ALDH2 genotypes on other aerodigestive tract cancers have not been investigated. ADH2/ALDH2 genotyping was performed on lymphocyte DNA samples from Japanese alcoholic men (526 cancer-free; 159 with solitary or multiple aerodigestive tract cancers, including 33 oropharyngolaryngeal, 112 esophageal, 38 stomach and 22 multiple primary cancers in two or three organs). After adjustment for age, drinking and smoking habits, and ADH2/ALDH2 genotypes, the presence of either ADH2*1/2*1 or ALDH2*1/2*2 significantly increased the risk for oropharyngolaryngeal cancer [odds ratios (ORs), 6.68 with ADH2*1/2*1 and 18.52 with ALDH2*1/2*2] and esophageal cancer (ORs, 2.64 and 13.50, respectively). For patients with both ADH2*1/2*1 and ALDH2*1/2*2, the risks for oropharyngolaryngeal and esophageal cancers were enhanced in a multiplicative fashion (OR = 121.77 and 40.40, respectively). A positive association with ALDH2*1/2*2 alone was observed for stomach cancer patients who also had oropharyngolaryngeal and/or esophageal cancer (OR = 110.58), but it was not observed for those with stomach cancer alone. Furthermore, in the presence of ALDH2*1/2*2, the risks for multiple intra-esophageal cancers (OR = 3.43) and for esophageal cancer with oropharyngolaryngeal and/or stomach cancer (OR = 3.95) were higher than the risks for solitary intra-esophageal cancer and for esophageal cancer alone, but these tendencies were not observed for ADH2*1/2*1 genotype. Alcoholics' population attributable risks due to ADH2/ALDH2 polymorphisms were estimated to be 82.0% for oropharyngolaryngeal cancer and 63.9% for esophageal cancer.

Genetic polymorphisms of alcohol dehydrogense-1B and aldehyde dehydrogenase-2, alcohol flushing, mean corpuscular volume, and aerodigestive tract neoplasia in Japanese drinkers.

PubMed

Yokoyama, Akira; Mizukami, Takeshi; Yokoyama, Tetsuji

2015-01-01

Genetic polymorphisms of alcohol dehydrogenase-1B (ADH1B) and aldehyde dehydrogenase-2 (ALDH2) modulate exposure levels to ethanol/acetaldehyde. Endoscopic screening of 6,014 Japanese alcoholics yielded high detection rates of esophageal squamous cell carcinoma (SCC; 4.1%) and head and neck SCC (1.0%). The risks of upper aerodigestive tract SCC/dysplasia, especially of multiple SCC/dysplasia, were increased in a multiplicative fashion by the presence of a combination of slow-metabolizing ADH1B*1/*1 and inactive heterozygous ALDH2*1/*2 because of prolonged exposure to higher concentrations of ethanol/acetaldehyde. A questionnaire asking about current and past facial flushing after drinking a glass (≈180 mL) of beer is a reliable tool for detecting the presence of inactive ALDH2. We invented a health-risk appraisal (HRA) model including the flushing questionnaire and drinking, smoking, and dietary habits. Esophageal SCC was detected at a high rate by endoscopic mass-screening in high HRA score persons. A total of 5.0% of 4,879 alcoholics had a history of (4.0%) or newly diagnosed (1.0%) gastric cancer. Their high frequency of a history of gastric cancer is partly explained by gastrectomy being a risk factor for alcoholism because of altered ethanol metabolism, e.g., by blood ethanol level overshooting. The combination of H. pylori-associated atrophic gastritis and ALDH2*1/*2 showed the greatest risk of gastric cancer in alcoholics. High detection rates of advanced colorectal adenoma/carcinoma were found in alcoholics, 15.7% of 744 immunochemical fecal occult blood test (IFOBT)-negative alcoholics and 31.5% of the 393 IFOBT-positive alcoholics. Macrocytosis with an MCV≥106 fl increased the risk of neoplasia in the entire aerodigestive tract of alcoholics, suggesting that poor nutrition as well as ethanol/acetaldehyde exposure plays an important role in neoplasia.

Dinuclear Zinc-Prophenol-Catalyzed Enantioselective α-Hydroxyacetate Aldol Reaction with Activated Ester Equivalents

PubMed Central

Trost, Barry M.; Michaelis, David J.; Truica, Mihai I.

2013-01-01

An enantioselective α-hydroxyacetate aldol reaction that employs N-acetyl pyrroles as activated ester equivalents and generates syn 1,2-diols in good yield and diastereoselectivity is reported. This dinuclear zinc Prophenol-catalyzed transformation proceeds with high enantioselectivity with a wide variety of substrates including aryl, alyl, and alkenyl aldehydes. The resulting α,β-dihydroxy activated esters are versatile intermediates for the synthesis of a variety of carboxylic acid derivatives including amides, esters, and unsymmetrical ketones. PMID:23947595

Asymmetric Functional Organozinc Additions to Aldehydes Catalyzed by 1,1′-Bi-2-naphthols (BINOLs)†

PubMed Central

2015-01-01

Conspectus Chiral alcohols are ubiquitous in organic structures. One efficient method to generate chiral alcohols is the catalytic asymmetric addition of a carbon nucleophile to a carbonyl compound since this process produces a C–C bond and a chiral center simultaneously. In comparison with the carbon nucleophiles such as an organolithium or a Grignard reagent, an organozinc reagent possesses the advantages of functional group tolerance and more mild reaction conditions. Catalytic asymmetric reactions of aldehydes with arylzincs, vinylzincs, and alkynylzincs to generate functional chiral alcohols are discussed in this Account. Our laboratory has developed a series of 1,1′-bi-2-naphthol (BINOL)-based chiral catalysts for the asymmetric organozinc addition to aldehydes. It is found that the 3,3′-dianisyl-substituted BINOLs are not only highly enantioselective for the alkylzinc addition to aldehydes, but also highly enantioselective for the diphenylzinc addition to aldehydes. A one-step synthesis has been achieved to incorporate Lewis basic amine groups into the 3,3′-positions of the partially hydrogenated H8BINOL. These H8BINOL–amine compounds have become more generally enantioselective and efficient catalysts for the diphenylzinc addition to aldehydes to produce various types of chiral benzylic alcohols. The application of the H8BINOL–amine catalysts is expanded by using in situ generated diarylzinc reagents from the reaction of aryl iodides with ZnEt2, which still gives high enantioselectivity and good catalytic activity. Such a H8BINOL–amine compound is further found to catalyze the highly enantioselective addition of vinylzincs, in situ generated from the treatment of vinyl iodides with ZnEt2, to aldehydes to give the synthetically very useful chiral allylic alcohols. We have discovered that the unfunctionalized BINOL in combination with ZnEt2 and Ti(OiPr)4 can catalyze the terminal alkyne addition to aldehydes to produce chiral propargylic alcohols

Neutral Lipid Biosynthesis in Engineered Escherichia coli: Jojoba Oil-Like Wax Esters and Fatty Acid Butyl Esters

PubMed Central

Kalscheuer, Rainer; Stöveken, Tim; Luftmann, Heinrich; Malkus, Ursula; Reichelt, Rudolf; Steinbüchel, Alexander

2006-01-01

Wax esters are esters of long-chain fatty acids and long-chain fatty alcohols which are of considerable commercial importance and are produced on a scale of 3 million tons per year. The oil from the jojoba plant (Simmondsia chinensis) is the main biological source of wax esters. Although it has a multitude of potential applications, the use of jojoba oil is restricted, due to its high price. In this study, we describe the establishment of heterologous wax ester biosynthesis in a recombinant Escherichia coli strain by coexpression of a fatty alcohol-producing bifunctional acyl-coenzyme A reductase from the jojoba plant and a bacterial wax ester synthase from Acinetobacter baylyi strain ADP1, catalyzing the esterification of fatty alcohols and coenzyme A thioesters of fatty acids. In the presence of oleate, jojoba oil-like wax esters such as palmityl oleate, palmityl palmitoleate, and oleyl oleate were produced, amounting to up to ca. 1% of the cellular dry weight. In addition to wax esters, fatty acid butyl esters were unexpectedly observed in the presence of oleate. The latter could be attributed to solvent residues of 1-butanol present in the medium component, Bacto tryptone. Neutral lipids produced in recombinant E. coli were accumulated as intracytoplasmic inclusions, demonstrating that the formation and structural integrity of bacterial lipid bodies do not require specific structural proteins. This is the first report on substantial biosynthesis and accumulation of neutral lipids in E. coli, which might open new perspectives for the biotechnological production of cheap jojoba oil equivalents from inexpensive resources employing recombinant microorganisms. PMID:16461689

Neutral lipid biosynthesis in engineered Escherichia coli: jojoba oil-like wax esters and fatty acid butyl esters.

PubMed

Kalscheuer, Rainer; Stöveken, Tim; Luftmann, Heinrich; Malkus, Ursula; Reichelt, Rudolf; Steinbüchel, Alexander

2006-02-01

Wax esters are esters of long-chain fatty acids and long-chain fatty alcohols which are of considerable commercial importance and are produced on a scale of 3 million tons per year. The oil from the jojoba plant (Simmondsia chinensis) is the main biological source of wax esters. Although it has a multitude of potential applications, the use of jojoba oil is restricted, due to its high price. In this study, we describe the establishment of heterologous wax ester biosynthesis in a recombinant Escherichia coli strain by coexpression of a fatty alcohol-producing bifunctional acyl-coenzyme A reductase from the jojoba plant and a bacterial wax ester synthase from Acinetobacter baylyi strain ADP1, catalyzing the esterification of fatty alcohols and coenzyme A thioesters of fatty acids. In the presence of oleate, jojoba oil-like wax esters such as palmityl oleate, palmityl palmitoleate, and oleyl oleate were produced, amounting to up to ca. 1% of the cellular dry weight. In addition to wax esters, fatty acid butyl esters were unexpectedly observed in the presence of oleate. The latter could be attributed to solvent residues of 1-butanol present in the medium component, Bacto tryptone. Neutral lipids produced in recombinant E. coli were accumulated as intracytoplasmic inclusions, demonstrating that the formation and structural integrity of bacterial lipid bodies do not require specific structural proteins. This is the first report on substantial biosynthesis and accumulation of neutral lipids in E. coli, which might open new perspectives for the biotechnological production of cheap jojoba oil equivalents from inexpensive resources employing recombinant microorganisms.

Evaluation of certain food additives.

PubMed

2009-01-01

This report represents the conclusions of a Joint FAO/WHO Expert Committee convened to evaluate the safety of various food additives, including flavouring agents, with a view to recommending acceptable daily intakes (ADIs) and to preparing specifications for identity and purity. The first part of the report contains a general discussion of the principles governing the toxicological evaluation and assessment of intake of food additives (in particular, flavouring agents). A summary follows of the Committee's evaluations of technical, toxicological and intake data for certain food additives (asparaginase from Aspergillus niger expressed in A. niger, calcium lignosulfonate (40-65), ethyl lauroyl arginate, paprika extract, phospholipase C expressed in Pichia pastoris, phytosterols, phytostanols and their esters, polydimethylsiloxane, steviol glycosides and sulfites [assessment of dietary exposure]) and 10 groups of related flavouring agents (aliphatic branched-chain saturated and unsaturated alcohols, aldehydes, acids and related esters; aliphatic linear alpha,beta-unsaturated aldehydes, acids and related alcohols, acetals and esters; aliphatic secondary alcohols, ketones and related esters; alkoxy-substituted allylbenzenes present in foods and essential oils and used as flavouring agents; esters of aliphatic acyclic primary alcohols with aliphatic linear saturated carboxylic acids; furan-substituted aliphatic hydrocarbons, alcohols, aldehydes, ketones, carboxylic acids and related esters, sulfides, disulfides and ethers; miscellaneous nitrogen-containing substances; monocyclic and bicyclic secondary alcohols, ketones and related esters; hydroxy- and alkoxy-substituted benzyl derivatives; and substances structurally related to menthol). Specifications for the following food additives were revised: canthaxanthin; carob bean gum and carob bean gum (clarified); chlorophyllin copper complexes, sodium and potassium salts; Fast Green FCF; guar gum and guar gum (clarified

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

Decarboxylative aldol reactions of allyl beta-keto esters via heterobimetallic catalysis.

PubMed

Lou, Sha; Westbrook, John A; Schaus, Scott E

2004-09-22

Mild and selective heterobimetallic-catalyzed decarboxylative aldol reactions involving allyl beta-keto esters have been developed. The reaction is promoted by Pd(0)- and Yb(III)-DIOP complexes at room temperature and involves the in situ formation of a ketone enolate from allyl beta-keto esters followed by addition of the enolate to aldehydes. The reaction is a new example of heterobimetallic catalysis in which the optimized reaction conditions require the addition of both metals.

Manganese catalyzed reductive amination of aldehydes using hydrogen as a reductant.

PubMed

Wei, Duo; Bruneau-Voisine, Antoine; Valyaev, Dmitry A; Lugan, Noël; Sortais, Jean-Baptiste

2018-04-24

A one-pot two-step procedure was developed for the alkylation of amines via reductive amination of aldehydes using molecular dihydrogen as a reductant in the presence of a manganese pyridinyl-phosphine complex as a pre-catalyst. After the initial condensation step, the reduction of imines formed in situ is performed under mild conditions (50-100 °C) with 2 mol% of catalyst and 5 mol% of tBuOK under 50 bar of hydrogen. Excellent yields (>90%) were obtained for a large combination of aldehydes and amines (40 examples), including aliphatic aldehydes and amino-alcohols.

Synthesis of amino ester-embedded benzimidazoles: a one-pot sequential protocol under metal-free neutral conditions.

PubMed

Roy, Priyabrata; Bodhak, Chandan; Pramanik, Animesh

2017-02-01

A one-pot three-component protocol has been developed for the synthesis of amino ester-embedded benzimidazoles under metal-free neutral conditions. Sequentially, the methodology involves coupling of an amino ester with 1-fluoro-2-nitrobenzene, reduction of the coupled nitroarene by sodium dithionite, and cyclization of the corresponding diamine with an aldehyde.

Lipoate ester multifunctional lubricant additives

USDA-ARS?s Scientific Manuscript database

Seven lipoate esters were synthesized by esterification of lipoic acid with different structures of alcohols in the presence of a solid acid catalyst and without solvent. The esters were obtained in good yield, characterized using 1H NMR and GPC; and their physical properties investigated. Four of t...

Regioselectivity switch in chiral amine-catalysed asymmetric addition of aldehydes to reactive enals.

PubMed

Kano, Taichi; Maruyama, Hiroki; Sakamoto, Ryu; Maruoka, Keiji

2015-06-21

In this communication, we present a regioselectivity switch for the chiral amine-catalysed asymmetric addition of aldehydes to reactive enals to afford either aldol adducts or conjugate adducts in a stereoselective fashion. The unprecedented asymmetric aldol reaction of aldehydes with enals was realized by the use of a diarylprolinol catalyst, giving synthetically useful and important chiral allylic alcohols.

Engineering modular ester fermentative pathways in Escherichia coli.

PubMed

Layton, Donovan S; Trinh, Cong T

2014-11-01

Sensation profiles are observed all around us and are made up of many different molecules, such as esters. These profiles can be mimicked in everyday items for their uses in foods, beverages, cosmetics, perfumes, solvents, and biofuels. Here, we developed a systematic 'natural' way to derive these products via fermentative biosynthesis. Each ester fermentative pathway was designed as an exchangeable ester production module for generating two precursors- alcohols and acyl-CoAs that were condensed by an alcohol acyltransferase to produce a combinatorial library of unique esters. As a proof-of-principle, we coupled these ester modules with an engineered, modular, Escherichia coli chassis in a plug-and-play fashion to create microbial cell factories for enhanced anaerobic production of a butyrate ester library. We demonstrated tight coupling between the modular chassis and ester modules for enhanced product biosynthesis, an engineered phenotype useful for directed metabolic pathway evolution. Compared to the wildtype, the engineered cell factories yielded up to 48 fold increase in butyrate ester production from glucose. Copyright © 2014 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

Doubly Vinylogous Aldol Reaction of Furoate Esters with Aldehydes and Ketones.

PubMed

Hartwig, William T; Sammakia, Tarek

2017-01-06

The use of bulky Lewis acids, aluminum tris(2,6-diphenylphenoxide) (ATPH) and aluminum tris(2,6-di-2-naphthylphenoxide) (ATNP), in the doubly vinylogous aldol reaction between methyl-5-methyl-2-furoate and aldehydes or ketones is described. These reactions proceed smoothly and in high yields with both enolizable and non-enolizable substrates. This C-C bond-forming reaction enables a new bond construction for the synthesis of functionalized furans.

The metabolism of ethanol-derived acetaldehyde by alcohol dehydrogenase (EC 1.1.1.1) and aldehyde dehydrogenase (EC 1.2.1.3) in Drosophila melanogaster larvae.

PubMed Central

Heinstra, P W; Geer, B W; Seykens, D; Langevin, M

1989-01-01

Both aldehyde dehydrogenase (ALDH, EC 1.2.1.3) and the aldehyde dehydrogenase activity of alcohol dehydrogenase (ADH, EC 1.1.1.1) were found to coexist in Drosophila melanogaster larvae. The enzymes, however, showed different inhibition patterns with respect to pyrazole, cyanamide and disulphiram. ALDH-1 and ALDH-2 isoenzymes were detected in larvae by electrophoretic methods. Nonetheless, in tracer studies in vivo, more than 75% of the acetaldehyde converted to acetate by the ADH ethanol-degrading pathway appeared to be also catalysed by the ADH enzyme. The larval fat body probably was the major site of this pathway. Images Fig. 1. Fig. 2. PMID:2499314

Expression Levels of the Yeast Alcohol Acetyltransferase Genes ATF1, Lg-ATF1, and ATF2 Control the Formation of a Broad Range of Volatile Esters

PubMed Central

Verstrepen, Kevin J.; Van Laere, Stijn D. M.; Vanderhaegen, Bart M. P.; Derdelinckx, Guy; Dufour, Jean-Pierre; Pretorius, Isak S.; Winderickx, Joris; Thevelein, Johan M.; Delvaux, Freddy R.

2003-01-01

Volatile aroma-active esters are responsible for the fruity character of fermented alcoholic beverages such as beer and wine. Esters are produced by fermenting yeast cells in an enzyme-catalyzed intracellular reaction. In order to investigate and compare the roles of the known Saccharomyces cerevisiae alcohol acetyltransferases, Atf1p, Atf2p and Lg-Atf1p, in volatile ester production, the respective genes were either deleted or overexpressed in a laboratory strain and a commercial brewing strain. Subsequently, the ester formation of the transformants was monitored by headspace gas chromatography and gas chromatography combined with mass spectroscopy (GC-MS). Analysis of the fermentation products confirmed that the expression levels of ATF1 and ATF2 greatly affect the production of ethyl acetate and isoamyl acetate. GC-MS analysis revealed that Atf1p and Atf2p are also responsible for the formation of a broad range of less volatile esters, such as propyl acetate, isobutyl acetate, pentyl acetate, hexyl acetate, heptyl acetate, octyl acetate, and phenyl ethyl acetate. With respect to the esters analyzed in this study, Atf2p seemed to play only a minor role compared to Atf1p. The atf1Δ atf2Δ double deletion strain did not form any isoamyl acetate, showing that together, Atf1p and Atf2p are responsible for the total cellular isoamyl alcohol acetyltransferase activity. However, the double deletion strain still produced considerable amounts of certain other esters, such as ethyl acetate (50% of the wild-type strain), propyl acetate (50%), and isobutyl acetate (40%), which provides evidence for the existence of additional, as-yet-unknown ester synthases in the yeast proteome. Interestingly, overexpression of different alleles of ATF1 and ATF2 led to different ester production rates, indicating that differences in the aroma profiles of yeast strains may be partially due to mutations in their ATF genes. PMID:12957907

Main-group compounds selectively oxidize mixtures of methane, ethane, and propane to alcohol esters.

PubMed

Hashiguchi, Brian G; Konnick, Michael M; Bischof, Steven M; Gustafson, Samantha J; Devarajan, Deepa; Gunsalus, Niles; Ess, Daniel H; Periana, Roy A

2014-03-14

Much of the recent research on homogeneous alkane oxidation has focused on the use of transition metal catalysts. Here, we report that the electrophilic main-group cations thallium(III) and lead(IV) stoichiometrically oxidize methane, ethane, and propane, separately or as a one-pot mixture, to corresponding alcohol esters in trifluoroacetic acid solvent. Esters of methanol, ethanol, ethylene glycol, isopropanol, and propylene glycol are obtained with greater than 95% selectivity in concentrations up to 1.48 molar within 3 hours at 180°C. Experiment and theory support a mechanism involving electrophilic carbon-hydrogen bond activation to generate metal alkyl intermediates. We posit that the comparatively high reactivity of these d(10) main-group cations relative to transition metals stems from facile alkane coordination at vacant sites, enabled by the overall lability of the ligand sphere and the absence of ligand field stabilization energies in systems with filled d-orbitals.

Direct reductive amination of aromatic aldehydes catalyzed by gold(I) complex under transfer hydrogenation conditions.

PubMed

Zhang, Ming; Yang, Hongwei; Zhang, Yan; Zhu, Chengjian; Li, Wei; Cheng, Yixiang; Hu, Hongwen

2011-06-21

The direct reductive amination of aromatic aldehydes has been achieved with excellent isolated yields (89-96%) using readily accessible Ph(3)PAuCl/AgOTf catalyst along with ethyl Hantzsch ester as hydrogen source under mild reaction conditions. This journal is © The Royal Society of Chemistry 2011

Telescoping Reactions with Trifluorodiazoethane-Derived Aza-Wittig Reagents and Allenyl esters.

PubMed

Zhang, Fa-Guang; Zeng, Jun-Liang; Tian, Yi-Qiang; Zheng, Yan; Cahard, Dominique; Ma, Jun-An

2018-05-28

A telescoping process involving the consecutive addition of four reagents (trifluorodiazoethane, phosphine, allenyl ester, and acetic acid) into a single reactor was developed for the novel functionalization of allenyl esters. First, new phosphazenes derived from trifluorodiazoethane and phosphines were generated and reacted with allenyl esters to give unexpected α-iminophosphoranes through the creation of C=P, C=N, and C-H bonds at the α-, β-, and γ-carbon atoms, respectively, of the allenyl esters. The α-iminophosphoranes did not react with aldehydes in a classic Wittig reaction, but instead β-enamino esters were obtained. The overall sequence of reactions offered a formal hydrohydrazonation of allenyl esters. The method was extended to other related diazo compounds and applied to the preparation of novel 5-pyrazolone derivatives. Not only is the telescoping process described herein an effective approach for truncating the multistep synthesis, but also each step has been dissected to understand and support the reaction mechanisms. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

DOE PAGES

Chung, Daehwan; Verbeke, Tobin J.; Cross, Karissa L.; ...

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

Polymorphisms of alcohol dehydrogenase-1B and aldehyde dehydrogenase-2 and the blood and salivary ethanol and acetaldehyde concentrations of Japanese alcoholic men.

PubMed

Yokoyama, Akira; Tsutsumi, Eri; Imazeki, Hiromi; Suwa, Yoshihide; Nakamura, Chizu; Yokoyama, Tetsuji

2010-07-01

The effects of genetic polymorphism of aldehyde dehydrogenase-2 (ALDH2) on alcohol metabolism are striking in nonalcoholics, and the effects of genetic polymorphism of alcohol dehydrogenase-1B (ADH1B) are modest at most, whereas genetic polymorphisms of both strongly affect the susceptibility to alcoholism and upper aerodigestive tract (UADT) cancer of drinkers. We evaluated associations between ADH1B/ADH1C/ALDH2 genotypes and the blood and salivary ethanol and acetaldehyde levels of 168 Japanese alcoholic men who came to our hospital for the first time in the morning and had been drinking until the day before. The ethanol levels in their blood and saliva were similar, but the acetaldehyde levels in their saliva were much higher than in their blood, probably because of acetaldehyde production by oral bacteria. Blood and salivary ethanol and acetaldehyde levels were both significantly higher in the subjects with the less active ADH1B*1/*1 genotype than in the ADH1B*2 carriers, but none of the levels differed according to ALDH2 genotype. Significant linkage disequilibrium was detected between the ADH1B and ADH1C genotypes, but ADH1C genotype did not affect the blood or salivary ethanol or acetaldehyde levels. High blood acetaldehyde levels were found even in the active ALDH2*1/*1 alcoholics, which were comparable with the levels of the inactive heterozygous ALDH2*1/*2 alcoholics with less active ADH1B*1/*1. The slope of the increase in blood acetaldehyde level as the blood ethanol level increased was significantly steeper in alcoholics with inactive heterozygous ALDH2*1/*2 plus ADH1B*2 allele than with any other genotype combinations, but the slopes of the increase in salivary acetaldehyde level as the salivary ethanol level increased did not differ between the groups of subjects with any combinations of ALDH2 and ADH1B genotypes. The ADH1B/ALDH2 genotype affected the blood and salivary ethanol and acetaldehyde levels of nonabstinent alcoholics in a different manner

40 CFR 52.1145 - Regulation on organic solvent use.

Code of Federal Regulations, 2014 CFR

2014-07-01

... hydrocarbons, alcohols, aldehydes, esters, ethers, or ketones having an olefinic or cycloolefinic type of... molecule except ethylbenzene: 8 percent; (iii) A combination of ethylbenzene, ketones having branched...

40 CFR 52.1145 - Regulation on organic solvent use.

Code of Federal Regulations, 2010 CFR

2010-07-01

... hydrocarbons, alcohols, aldehydes, esters, ethers, or ketones having an olefinic or cycloolefinic type of... molecule except ethylbenzene: 8 percent; (iii) A combination of ethylbenzene, ketones having branched...

40 CFR 52.1145 - Regulation on organic solvent use.

Code of Federal Regulations, 2011 CFR

2011-07-01

... hydrocarbons, alcohols, aldehydes, esters, ethers, or ketones having an olefinic or cycloolefinic type of... molecule except ethylbenzene: 8 percent; (iii) A combination of ethylbenzene, ketones having branched...

40 CFR 52.1145 - Regulation on organic solvent use.

Code of Federal Regulations, 2012 CFR

2012-07-01

... hydrocarbons, alcohols, aldehydes, esters, ethers, or ketones having an olefinic or cycloolefinic type of... molecule except ethylbenzene: 8 percent; (iii) A combination of ethylbenzene, ketones having branched...

40 CFR 52.1145 - Regulation on organic solvent use.

Code of Federal Regulations, 2013 CFR

2013-07-01

... hydrocarbons, alcohols, aldehydes, esters, ethers, or ketones having an olefinic or cycloolefinic type of... molecule except ethylbenzene: 8 percent; (iii) A combination of ethylbenzene, ketones having branched...

40 CFR 52.254 - Organic solvent usage.

Code of Federal Regulations, 2011 CFR

2011-07-01

... volume of solvent: (1) A combination of hydrocarbons, alcohols, aldehydes, esters, ethers, or ketones... benzoate; 8 percent; (3) A combination of ethylbenzene, ketones having branched hydrocarbon structures...

Coniferyl aldehyde 5-hydroxylation and methylation direct syringyl lignin biosynthesis in angiosperms

PubMed Central

Osakabe, Keishi; Tsao, Cheng Chung; Li, Laigeng; Popko, Jacqueline L.; Umezawa, Toshiaki; Carraway, Daniel T.; Smeltzer, Richard H.; Joshi, Chandrashekhar P.; Chiang, Vincent L.

1999-01-01

A central question in lignin biosynthesis is how guaiacyl intermediates are hydroxylated and methylated to the syringyl monolignol in angiosperms. To address this question, we cloned cDNAs encoding a cytochrome P450 monooxygenase (LsM88) and a caffeate O-methyltransferase (COMT) from sweetgum (Liquidambar styraciflua) xylem. Mass spectrometry-based functional analysis of LsM88 in yeast identified it as coniferyl aldehyde 5-hydroxylase (CAld5H). COMT expressed in Escherichia coli methylated 5-hydroxyconiferyl aldehyde to sinapyl aldehyde. Together, CAld5H and COMT converted coniferyl aldehyde to sinapyl aldehyde, suggesting a CAld5H/COMT-mediated pathway from guaiacyl to syringyl monolignol biosynthesis via coniferyl aldehyde that contrasts with the generally accepted route to sinapate via ferulate. Although the CAld5H/COMT enzyme system can mediate the biosynthesis of syringyl monolignol intermediates through either route, kcat/Km of CAld5H for coniferyl aldehyde was ≈140 times greater than that for ferulate. More significantly, when coniferyl aldehyde and ferulate were present together, coniferyl aldehyde was a noncompetitive inhibitor (Ki = 0.59 μM) of ferulate 5-hydroxylation, thereby eliminating the entire reaction sequence from ferulate to sinapate. In contrast, ferulate had no effect on coniferyl aldehyde 5-hydroxylation. 5-Hydroxylation also could not be detected for feruloyl-CoA or coniferyl alcohol. Therefore, in the presence of coniferyl aldehyde, ferulate 5-hydroxylation does not occur, and the syringyl monolignol can be synthesized only from coniferyl aldehyde. Endogenous coniferyl, 5-hydroxyconiferyl, and sinapyl aldehydes were detected, consistent with in vivo operation of the CAld5H/COMT pathway from coniferyl to sinapyl aldehydes via 5-hydroxyconiferyl aldehyde for syringyl monolignol biosynthesis. PMID:10430877

Olfactory Impact of Higher Alcohols on Red Wine Fruity Ester Aroma Expression in Model Solution.

PubMed

Cameleyre, Margaux; Lytra, Georgia; Tempere, Sophie; Barbe, Jean-Christophe

2015-11-11

This study focused on the impact of five higher alcohols on the perception of fruity aroma in red wines. Various aromatic reconstitutions were prepared, consisting of 13 ethyl esters and acetates and 5 higher alcohols, all at the average concentrations found in red wine. These aromatic reconstitutions were prepared in several matrices. Sensory analysis revealed the interesting behavior of certain compounds among the five higher alcohols following their individual addition or omission. The "olfactory threshold" of the fruity pool was evaluated in several matrices: dilute alcohol solution, dilute alcohol solution containing 3-methylbutan-1-ol or butan-1-ol individually, and dilute alcohol solution containing the mixture of five higher alcohols, blended together at various concentrations. The presence of 3-methylbutan-1-ol or butan-1-ol alone led to a significant decrease in the "olfactory threshold" of the fruity reconstitution, whereas the mixture of alcohols raised the olfactory threshold. Sensory profiles highlighted changes in the perception of fruity nuances in the presence of the mixture of higher alcohols, with specific perceptive interactions, including a relevant masking effect on fresh- and jammy-fruit notes of the fruity mixture in both dilute alcohol solution and dearomatized red wine matrices. When either 3-methylbutan-1-ol or butan-1-ol was added to the fruity reconstitution in dilute alcohol solution, an enhancement of butyric notes was reported with 3-methylbutan-1-ol and fresh- and jammy-fruit with butan-1-ol. This study, the first to focus on the impact of higher alcohols on fruity aromatic expression, revealed that these compounds participate, both quantitatively and qualitatively, in masking fruity aroma perception in a model fruity wine mixture.

Enantioselective synthesis of syn/anti-1,3-amino alcohols via proline-catalyzed sequential alpha-aminoxylation/alpha-amination and Horner-Wadsworth-Emmons olefination of aldehydes.

PubMed

Jha, Vishwajeet; Kondekar, Nagendra B; Kumar, Pradeep

2010-06-18

A novel and general method for asymmetric synthesis of both syn/anti-1,3-amino alcohols is described. The method uses proline-catalyzed sequential alpha-aminoxylation/ alpha-amination and Horner-Wadsworth-Emmons (HWE) olefination of aldehydes as the key step. By using this method, a short synthesis of a bioactive molecule, (R)-1-((S)-1-methylpyrrolidin-2-yl)-5-phenylpentan-2-ol, is also accomplished.

Mitochondria-targeted ubiquinone (MitoQ) enhances acetaldehyde clearance by reversing alcohol-induced posttranslational modification of aldehyde dehydrogenase 2: A molecular mechanism of protection against alcoholic liver disease.

PubMed

Hao, Liuyi; Sun, Qian; Zhong, Wei; Zhang, Wenliang; Sun, Xinguo; Zhou, Zhanxiang

2018-04-01

Alcohol metabolism in the liver generates highly toxic acetaldehyde. Breakdown of acetaldehyde by aldehyde dehydrogenase 2 (ALDH2) in the mitochondria consumes NAD + and generates reactive oxygen/nitrogen species, which represents a fundamental mechanism in the pathogenesis of alcoholic liver disease (ALD). A mitochondria-targeted lipophilic ubiquinone (MitoQ) has been shown to confer greater protection against oxidative damage in the mitochondria compared to untargeted antioxidants. The present study aimed to investigate if MitoQ could preserve mitochondrial ALDH2 activity and speed up acetaldehyde clearance, thereby protects against ALD. Male C57BL/6J mice were exposed to alcohol for 8 weeks with MitoQ supplementation (5mg/kg/d) for the last 4 weeks. MitoQ ameliorated alcohol-induced oxidative/nitrosative stress and glutathione deficiency. It also reversed alcohol-reduced hepatic ALDH activity and accelerated acetaldehyde clearance through modulating ALDH2 cysteine S-nitrosylation, tyrosine nitration and 4-hydroxynonenol adducts formation. MitoQ ameliorated nitric oxide (NO) donor-mediated ADLH2 S-nitrosylation and nitration in Hepa-1c1c7 cells under glutathion depletion condition. In addition, alcohol-increased circulating acetaldehyde levels were accompanied by reduced intestinal ALDH activity and impaired intestinal barrier. In accordance, MitoQ reversed alcohol-increased plasma endotoxin levels and hepatic toll-like receptor 4 (TLR4)-NF-κB signaling along with subsequent inhibition of inflammatory cell infiltration. MitoQ also reversed alcohol-induced hepatic lipid accumulation through enhancing fatty acid β-oxidation. Alcohol-induced ER stress and apoptotic cell death signaling were reversed by MitoQ. This study demonstrated that speeding up acetaldehyde clearance by preserving ALDH2 activity critically mediates the beneficial effect of MitoQ on alcohol-induced pathogenesis at the gut-liver axis. Copyright © 2017 The Authors. Published by Elsevier B

Lewis base activation of Lewis acids: catalytic, enantioselective addition of glycolate-derived silyl ketene acetals to aldehydes.

PubMed

Denmark, Scott E; Chung, Won-Jin

2008-06-20

A catalytic system involving silicon tetrachloride and a chiral, Lewis basic bisphosphoramide catalyst is effective for the addition of glycolate-derived silyl ketene acetals to aldehydes. It was found that the sense of diastereoselectivity could be modulated by changing the size of the substituents on the silyl ketene acetals. In general, the trimethylsilyl ketene acetals derived from methyl glycolates with a large protecting group on the alpha-oxygen provide enantiomerically enriched alpha,beta-dihydroxy esters with high syn-diastereoselectivity, whereas the tert-butyldimethylsilyl ketene acetals derived from bulky esters of alpha-methoxyacetic acid provide enantiomerically enriched alpha,beta-dihydroxy esters with high anti-diastereoselecitvity.

Benzoyl radicals from (hetero)aromatic aldehydes. Decatungstate photocatalyzed synthesis of substituted aromatic ketones.

PubMed

Ravelli, Davide; Zema, Michele; Mella, Mariella; Fagnoni, Maurizio; Albini, Angelo

2010-09-21

Benzoyl radicals are generated directly from (hetero)aromatic aldehydes upon tetrabutylammonium decatungstate ((n-Bu(4)N)(4)W(10)O(32)), TBADT) photocatalysis under mild conditions. In the presence of alpha,beta-unsaturated esters, ketones and nitriles radical conjugate addition ensues and gives the corresponding beta-functionalized aryl alkyl ketones in moderate to good yields (stereoselectively in the case of 3-methylene-2-norbornanone). Due to the mild reaction conditions the presence of various functional groups on the aromatic ring is tolerated (e.g. methyl, methoxy, chloro). The method can be applied to hetero-aromatic aldehydes whether electron-rich (e.g. thiophene-2-carbaldehyde) or electron-poor (e.g. pyridine-3-carbaldehyde).

Catalytic Carbonyl Allylation, Propargylation and Vinylation from the Alcohol or Aldehyde Oxidation Level via C-C Bond Forming Hydrogenation and Transfer Hydrogenation: A Departure from Preformed Organometallic Reagents**

PubMed Central

Bower, John F.; Kim, In Su; Patman, Ryan L.; Krische, Michael J.

2009-01-01

Classical protocols for carbonyl allylation, propargylation and vinylation typically rely upon the use of preformed allyl metal, allenyl metal and vinyl metal reagents, respectively, mandating stoichiometric generation of metallic byproducts. Through transfer hydrogenative C-C coupling, carbonyl addition may be achieved from the aldehyde or alcohol oxidation level in the absence of stoichiometric organometallic reagents or metallic reductants. Here, we review transfer hydrogenative methods for carbonyl addition, which encompass the first cataltyic protocols enabling direct C–H functionalization of alcohols. PMID:19040235

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.

Synthesis and low temperature characterization of iso-oleic ester derivatives

USDA-ARS?s Scientific Manuscript database

Three new iso-oleic ester derivatives (i.e., isopropyl esters (IOA-iPrE), n-butyl esters (IOA-n-BuE), and 2-ethylhexyl esters (IOA-2-EHE)) were synthesized from iso-oleic acid (IOA) using a standard esterification method. These esterified alcohols were chosen because of their bulky and branched-cha...

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.

Evaluation of certain food additives.

PubMed

2012-01-01

This report represents the conclusions of a Joint FAO/WHO Expert Committee convened to evaluate the safety of various food additives, including flavouring agents, with a view to concluding as to safety concerns and to preparing specifications for identity and purity. The first part of the report contains a general discussion of the principles governing the toxicological evaluation of and assessment of dietary exposure to food additives, including flavouring agents. A summary follows of the Committee's evaluations of technical, toxicological and dietary exposure data for five food additives (magnesium dihydrogen diphosphate; mineral oil (medium and low viscosity) classes II and III; 3-phytase from Aspergillus niger expressed in Aspergillus niger; serine protease (chymotrypsin) from Nocardiopsis prasina expressed in Bacillus licheniformis; and serine protease (trypsin) from Fusarium oxysporum expressed in Fusarium venenatum) and 16 groups of flavouring agents (aliphatic and aromatic amines and amides; aliphatic and aromatic ethers; aliphatic hydrocarbons, alcohols, aldehydes, ketones, carboxylic acids and related esters, sulfides, disulfides and ethers containing furan substitution; aliphatic linear alpha,beta-unsaturated aldehydes, acids and related alcohols, acetals and esters; amino acids and related substances; epoxides; furfuryl alcohol and related substances; linear and branched-chain aliphatic, unsaturated, unconjugated alcohols, aldehydes, acids and related esters; miscellaneous nitrogen-containing substances; phenol and phenol derivatives; pyrazine derivatives; pyridine, pyrrole and quinoline derivatives; saturated aliphatic acyclic branched-chain primary alcohols, aldehydes and acids; simple aliphatic and aromatic sulfides and thiols; sulfur-containing heterocyclic compounds; and sulfur-substituted furan derivatives). Specifications for the following food additives were revised: ethyl cellulose, mineral oil (medium viscosity), modified starches and titanium

A Hepatocyte-Mimicking Antidote for Alcohol Intoxication.

PubMed

Xu, Duo; Han, Hui; He, Yuxin; Lee, Harrison; Wu, Di; Liu, Fang; Liu, Xiangsheng; Liu, Yang; Lu, Yunfeng; Ji, Cheng

2018-04-11

Alcohol intoxication causes serious diseases, whereas current treatments are mostly supportive and unable to remove alcohol efficiently. Upon alcohol consumption, alcohol is sequentially oxidized to acetaldehyde and acetate by the endogenous alcohol dehydrogenase and aldehyde dehydrogenase, respectively. Inspired by the metabolism of alcohol, a hepatocyte-mimicking antidote for alcohol intoxication through the codelivery of the nanocapsules of alcohol oxidase (AOx), catalase (CAT), and aldehyde dehydrogenase (ALDH) to the liver, where AOx and CAT catalyze the oxidation of alcohol to acetaldehyde, while ALDH catalyzes the oxidation of acetaldehyde to acetate. Administered to alcohol-intoxicated mice, the antidote rapidly accumulates in the liver and enables a significant reduction of the blood alcohol concentration. Moreover, blood acetaldehyde concentration is maintained at an extremely low level, significantly contributing to liver protection. Such an antidote, which can eliminate alcohol and acetaldehyde simultaneously, holds great promise for the treatment of alcohol intoxication and poisoning and can provide therapeutic benefits. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The Arabidopsis thaliana REDUCED EPIDERMAL FLUORESCENCE1 gene encodes an aldehyde dehydrogenase involved in ferulic acid and sinapic acid biosynthesis.

PubMed

Nair, Ramesh B; Bastress, Kristen L; Ruegger, Max O; Denault, Jeff W; Chapple, Clint

2004-02-01

Recent research has significantly advanced our understanding of the phenylpropanoid pathway but has left in doubt the pathway by which sinapic acid is synthesized in plants. The reduced epidermal fluorescence1 (ref1) mutant of Arabidopsis thaliana accumulates only 10 to 30% of the sinapate esters found in wild-type plants. Positional cloning of the REF1 gene revealed that it encodes an aldehyde dehydrogenase, a member of a large class of NADP(+)-dependent enzymes that catalyze the oxidation of aldehydes to their corresponding carboxylic acids. Consistent with this finding, extracts of ref1 leaves exhibit low sinapaldehyde dehydrogenase activity. These data indicate that REF1 encodes a sinapaldehyde dehydrogenase required for sinapic acid and sinapate ester biosynthesis. When expressed in Escherichia coli, REF1 was found to exhibit both sinapaldehyde and coniferaldehyde dehydrogenase activity, and further phenotypic analysis of ref1 mutant plants showed that they contain less cell wall-esterified ferulic acid. These findings suggest that both ferulic acid and sinapic acid are derived, at least in part, through oxidation of coniferaldehyde and sinapaldehyde. This route is directly opposite to the traditional representation of phenylpropanoid metabolism in which hydroxycinnamic acids are instead precursors of their corresponding aldehydes.

Essential Oils in Foods: From Ancient Times to the 21st Century.

PubMed

Sendra, Esther

2016-06-14

Medicinal plants and culinary herbs have been used since ancient times. Essential oils (EO) are a mixture of numerous compounds, mainly terpenes, alcohols, acids, esters, epoxides, aldehydes, ketones,aminesandsulfides,thatareprobablyproducedbyplantsasaresponsetostress[1].[...].

Synthetic Methods for Ester Bond Formation and Conformational Analysis of Ester-Containing Carbohydrates

NASA Astrophysics Data System (ADS)

Hackbusch, Sven

carbohydrate based compounds with specific shape constraints for its use as enzyme inhibitors or similar targets. In addition, the above project led to the development of a methodology for the synthesis of symmetrical ester molecules from primary alcohols using a mild oxidative esterification reaction, which proceeds in hydrous solvents using a nitrosyl radical catalyst. The reaction could be performed with a variety of alcohols and the resulting compounds are of interest in the fragrance and flavor industries.

Composition of the epicuticular waxes coating the adaxial side of Phyllostachys aurea leaves: Identification of very-long-chain primary amides.

PubMed

Racovita, Radu C; Jetter, Reinhard

2016-10-01

The present study presents comprehensive chemical analyses of cuticular wax mixtures of the bamboo Phyllostachys aurea. The epicuticular and intracuticular waxes were sampled selectively from the adaxial side of leaves on young and old plants and investigated by gas chromatography-mass spectrometry and flame ionization detection. The epi- and intracuticular layers on young and old leaves had wax loads ranging from 1.7 μg/cm(2) to 1.9 μg/cm(2). Typical very-long-chain aliphatic wax constituents were found with characteristic chain length patterns, including alkyl esters (primarily C48), alkanes (primarily C29), fatty acids (primarily C28 and C16), primary alcohols (primarily C28) and aldehydes (primarily C30). Alicyclic wax components were identified as tocopherols and triterpenoids, including substantial amounts of triterpenoid esters. Alkyl esters, alkanes, fatty acids and aldehydes were found in greater amounts in the epicuticular layer, while primary alcohols and most terpenoids accumulated more in the intracuticular wax. Alkyl esters occurred as mixtures of metamers, combining C20 alcohol with various acids into shorter ester homologs (C36C40), and a wide range of alcohols with C22 and C24 acids into longer esters (C42C52). Primary amides were identified, with a characteristic chain length profile peaking at C30. The amides were present exclusively in the epicuticular layer and thus at or near the surface, where they may affect plant-herbivore or plant-pathogen interactions. Copyright © 2016 Elsevier Ltd. All rights reserved.

Body odor aldehyde reduction by acetic acid bacterial extract including enzymes: alcohol dehydrogenase and aldehyde dehydrogenase.

PubMed

Yoshioka, N; Kurata, K; Takahashi, T; Ariizumi, M; Mori, T; Fujisawa, H; Kameyama, N; Okuyama, Y

2018-06-13

Body odor is mainly caused by secreted sweat. Although sweat is almost odorless immediately after secretion, decomposition or denaturation of components contained in sweat by bacteria on the skin surface contributes to unpleasant body odor. Body odor is due to various substances and aldehydes are primarily detected in body odor [1-4]. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Indium-mediated asymmetric barbier-type allylations: additions to aldehydes and ketones and mechanistic investigation of the organoindium reagents.

PubMed

Haddad, Terra D; Hirayama, Lacie C; Singaram, Bakthan

2010-02-05

We report a simple, efficient, and general method for the indium-mediated enantioselective allylation of aromatic and aliphatic aldehydes and ketones under Barbier-type conditions in a one-pot synthesis affording the corresponding chiral alcohol products in very good yield (up to 99%) and enantiomeric excess (up to 93%). Our method is able to tolerate various functional groups, such as esters, nitriles, and phenols. Additionally, more substituted allyl bromides, such as crotyl and cinnamyl bromide, can be used providing moderate enantioselectivity (72% and 56%, respectively) and excellent diastereoselectivity when employing cinnamyl bromide (>95/5 anti/syn). However, the distereoselectivity when using crotyl bromide was poor and other functionalized allyl bromides under our method afforded low enantioselectivities for the alcohol products. In these types of indium-mediated additions, solvent plays a major role in determining the nature of the organoindium intermediate and we observed the susceptibility of some allylindium intermediates to hydrolysis in protic solvents. Under our reaction conditions using a polar aprotic solvent, we suggest that an allylindium(III) species is the active allylating intermediate. In addition, we have observed the presence of a shiny, indium(0) nugget throughout the reaction, irrespective of the stoichiometry, indicating disproportionation of indium halide byproduct formed during the reaction.

Aldehyde dehydrogenase 2 polymorphism for development to hepatocellular carcinoma in East Asian alcoholic liver cirrhosis.

PubMed

Abe, Hiroshi; Aida, Yuta; Seki, Nobuyoshi; Sugita, Tomonori; Tomita, Yoichi; Nagano, Tomohisa; Itagaki, Munenori; Sutoh, Satoshi; Nagatsuma, Keisuke; Itoh, Kyoko; Matsuura, Tomokazu; Aizawa, Yoshio

2015-09-01

We aimed to clarify the influences of aldehyde dehydrogenase 2 (ALDH2), alcohol dehydrogenase 1B (ADH1B) polymorphisms, and ethanol consumption profile to hepatocellular carcinoma (HCC) development in alcoholic liver cirrhosis without chronic hepatitis B and C virus infection (non-B non-C). Of 236 freshly diagnosed non-B non-C alcoholic liver cirrhosis patients, 67 were diagnosed as HCC and the remaining 169 as not having HCC. The relationship between the genetic polymorphisms and development to HCC were evaluated in well-matched patients with HCC (HCC group, n = 67) and without HCC (non-HCC group, n = 67) using propensity scores in age, sex, and prevalence of diabetes mellitus. Daily amount of ethanol consumption was significantly lower (P = 0.005), and consumptive period was significantly longer (P = 0.003) in HCC group than non-HCC group. Of 134 well-matched patients, 113 (84.3%) had ALDH2*1/*1 genotype and 21 (15.7%) had ALDH2*1/*2 genotype. In HCC development, consumptive long period (P = 0.007) and carrying ALDH2*1/*2 genotype (P = 0.026) were identified as significant factors independently participated, while there was no relation to ADH1B polymorphism. In addition, consumptive period was significantly longer in HCC group than non-HCC group in ALDH2*1/*1 genotype patients (P = 0.0005), while there was no difference in profile of ethanol consumption in ALDH2*1/*2 genotype patients. Among HCC group, daily (P = 3.78 × 10(-6) ) and cumulative amount (P = 4.89 × 10(-6) ) of ethanol consumption were significantly higher in ALDH2*1/*1 genotype patients than ALDH2*1/*2 genotype patients. In alcoholic liver cirrhosis, investigations of ALDH2 polymorphism and ethanol consumption profile are useful for prediction of HCC development. © 2015 Journal of Gastroenterology and Hepatology Foundation and Wiley Publishing Asia Pty Ltd.

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.

Chemoselective Hydrogenation of Aldehydes under Mild, Base-Free Conditions: Manganese Outperforms Rhenium

PubMed Central

2018-01-01

Several hydride Mn(I) and Re(I) PNP pincer complexes were applied as catalysts for the homogeneous chemoselective hydrogenation of aldehydes. Among these, [Mn(PNP-iPr)(CO)2(H)] was found to be one of the most efficient base metal catalysts for this process and represents a rare example which permits the selective hydrogenation of aldehydes in the presence of ketones and other reducible functionalities, such as C=C double bonds, esters, or nitriles. The reaction proceeds at room temperature under base-free conditions with catalyst loadings between 0.1 and 0.05 mol% and a hydrogen pressure of 50 bar (reaching TONs of up to 2000). A mechanism which involves an outer-sphere hydride transfer and reversible PNP ligand deprotonation/protonation is proposed. Analogous isoelectronic and isostructural Re(I) complexes were only poorly active. PMID:29755828

Bioactivation of cinnamic alcohol forms several strong skin sensitizers.

PubMed

Niklasson, Ida B; Ponting, David J; Luthman, Kristina; Karlberg, Ann-Therese

2014-04-21

Cinnamic alcohol is a frequent contact allergen, causing allergic contact dermatitis (ACD) in a substantial number of individuals sensitized from contacts with fragrances. Hence, cinnamic alcohol is one of the constituents in fragrance mix I (FM I) used for screening contact allergy in dermatitis patients. Cinnamic alcohol lacks structural alerts for protein reactivity and must therefore be activated by either air oxidation or bioactivation to be able to act as a sensitizer. In the present study, we explored the bioactivation of cinnamic alcohol using human liver microsomes (HLM), and the potential pathways for these reactions were modeled by in silico (DFT) techniques. Subsequently, the reactivity of cinnamic alcohol and its metabolites toward a model hexapeptide were investigated. In addition to cinnamic aldehyde and cinnamic acid, two highly sensitizing epoxides previously unobserved in studies of bioactivation were detected in the incubations with HLMs. Formation of epoxy cinnamic aldehyde was shown (both by the liver microsomal experiments, in which no depletion of epoxy cinnamic alcohol was observed after initial formation, and by the very high activation energy found for the oxidation thereof by calculations) to proceed via cinnamic aldehyde and not epoxy cinnamic alcohol.

Preparation of polyol esters based on vegetable and animal fats.

PubMed

Gryglewicz, S; Piechocki, W; Gryglewicz, G

2003-03-01

The possibility of using some natural fats: rapeseed oil, olive oil and lard, as starting material for the preparation of neopentyl glycol (NPG) and trimethylol propane (TMP) esters is reported. The syntheses of final products were performed by alcoholysis of fatty acid methyl esters, obtained from natural fats studied, with the appropriate polyhydric alcohol using calcium methoxide as a catalyst. The basic physicochemical properties of the NPG and TMP esters synthesized were the following: viscosity at 40 degrees C in the range of 13.5-37.6 cSt, pour point between -10.5 and -17.5 degrees C and very high viscosity indices, higher than 200. Generally, the esters of neopentyl alcohols were characterized by higher stability in thermo-oxidative conditions in comparison to native triglycerides. Due to the low content of polyunsaturated acids, the olive oil based esters showed the highest thermo-oxidative resistance. Also, methyl esters of fatty acids of lard would constitute a good raw material for the synthesis of lubricating oils, provided that their saturated acids content was lowered. This permits synthesis of NPG and TMP esters with a lower pour point (below -10 degrees C) than natural lard (+33 degrees C).

The Arabidopsis thaliana REDUCED EPIDERMAL FLUORESCENCE1 Gene Encodes an Aldehyde Dehydrogenase Involved in Ferulic Acid and Sinapic Acid Biosynthesis

PubMed Central

Nair, Ramesh B.; Bastress, Kristen L.; Ruegger, Max O.; Denault, Jeff W.; Chapple, Clint

2004-01-01

Recent research has significantly advanced our understanding of the phenylpropanoid pathway but has left in doubt the pathway by which sinapic acid is synthesized in plants. The reduced epidermal fluorescence1 (ref1) mutant of Arabidopsis thaliana accumulates only 10 to 30% of the sinapate esters found in wild-type plants. Positional cloning of the REF1 gene revealed that it encodes an aldehyde dehydrogenase, a member of a large class of NADP+-dependent enzymes that catalyze the oxidation of aldehydes to their corresponding carboxylic acids. Consistent with this finding, extracts of ref1 leaves exhibit low sinapaldehyde dehydrogenase activity. These data indicate that REF1 encodes a sinapaldehyde dehydrogenase required for sinapic acid and sinapate ester biosynthesis. When expressed in Escherichia coli, REF1 was found to exhibit both sinapaldehyde and coniferaldehyde dehydrogenase activity, and further phenotypic analysis of ref1 mutant plants showed that they contain less cell wall–esterified ferulic acid. These findings suggest that both ferulic acid and sinapic acid are derived, at least in part, through oxidation of coniferaldehyde and sinapaldehyde. This route is directly opposite to the traditional representation of phenylpropanoid metabolism in which hydroxycinnamic acids are instead precursors of their corresponding aldehydes. PMID:14729911

Oxidation of Alcohols by Botrytis cinerea1

PubMed Central

Fukuda, D. S.; Brannon, D. R.

1971-01-01

Crude cell-free preparations of Botrytis cinerea were found to oxidize straight-chain primary alcohols (except methanol), aromatic primary alcohols, and unsaturated primary alcohols. The resulting products were the corresponding aldehydes and an equal molar quantity of hydrogen peroxide. PMID:5102778

Trifluoromethylation of ketones and aldehydes with Bu₃SnCF₃.

PubMed

Sanhueza, Italo A; Bonney, Karl J; Nielsen, Mads C; Schoenebeck, Franziska

2013-08-02

The (trifluoromethyl)stannane reagent, Bu3SnCF3, was found to react under CsF activation with ketones and aldehydes to the corresponding trifluoromethylated stannane ether intermediates at room temperature in high yield. Only a mildly acidic extraction (aqueous NH4Cl) is required to release the corresponding trifluoromethyl alcohol products. The protocol is compatible with acid-sensitive functional groups.

Expedient generation of patterned surface aldehydes by microfluidic oxidation for chemoselective immobilization of ligands and cells.

PubMed

Westcott, Nathan P; Pulsipher, Abigail; Lamb, Brian M; Yousaf, Muhammad N

2008-09-02

An expedient and inexpensive method to generate patterned aldehydes on self-assembled monolayers (SAMs) of alkanethiolates on gold with control of density for subsequent chemoselective immobilization from commercially available starting materials has been developed. Utilizing microfluidic cassettes, primary alcohol oxidation of tetra(ethylene glycol) undecane thiol and 11-mercapto-1-undecanol SAMs was performed directly on the surface generating patterned aldehyde groups with pyridinium chlorochromate. The precise density of surface aldehydes generated can be controlled and characterized by electrochemistry. For biological applications, fibroblast cells were seeded on patterned surfaces presenting biospecifc cell adhesive (Arg-Glyc-Asp) RGD peptides.

Mechanisms of aldehyde-induced adenosinetriphosphatase activities of kinases.

PubMed

Rendina, A R; Cleland, W W

1984-10-23

Aldehyde analogues of the normal alcohol substrates induce ATPase activities by glycerokinase (D-glyceraldehyde), fructose-6-phosphate kinase (2,5-anhydromannose 6-phosphate), fructokinase (2,5-anhydromannose or 2,5-anhydrotalose), hexokinase (D-gluco-hexodialdose), choline kinase (betaine aldehyde), and pyruvate kinase (glyoxylate). Since purified deuterated aldehydes give V and V/K isotope effects near 1.0 for glycerokinase, fructokinase with 2,5-anhydro[1-2H]talose, hexokinase, choline kinase, and pyruvate kinase, the hydrates of these almost fully hydrated aldehydes are the activators of the ATPase reactions. Fructose-6-phosphate kinase and fructokinase with 2,5-anhydro[1-2H]mannose show V/K deuterium isotope effects of 1.10 and 1.22, respectively, suggesting either that both hydrate and free aldehyde may be activators (predicted values are 1.37 if only the free aldehyde activates the ATPase) or, more likely, that the phosphorylated hydrate breaks down in a rate-limiting step on the enzyme while MgADP is still present and the back-reaction to yield free hydrate in solution is still possible. 18O was transferred from the aldehyde hydrate to phosphate during the ATPase reactions of glycerokinase, fructose-6-phosphate kinase, fructokinase, and hexokinase but not with choline kinase or pyruvate kinase. Thus, direct phosphorylation of the hydrates by the first four enzymes gives the phosphate adduct of the aldehyde, which decomposes nonenzymatically, while with choline kinase and pyruvate kinase the hydrates induce transfer to water (metal-bound hydroxide or water with pyruvate kinase on the basis of pH profiles). Observation of a lag in the release of phosphate from the glycerokinase ATPase reaction at 15 degrees C supports the existence of a phosphorylated hydrate intermediate with a rate constant for breakdown of 0.035-0.043 s-1 at this temperature. Kinases that phosphorylate creatine, 3-phosphoglycerate, and acetate did not exhibit ATPase activities in the

Mild and Selective Hydrozirconation of Amides to Aldehydes Using Cp2Zr(H)Cl

PubMed Central

Spletstoser, Jared T.; White, Jonathan M.; Tunoori, Ashok Rao; Georg, Gunda I.

2008-01-01

An investigation of the use of Cp2Zr(H)Cl (Schwartz’s reagent) to reduce a variety of amides to the corresponding aldehydes under very mild reaction conditions and in high yields is reported. A range of tertiary amides, including Weinreb’s amide, can be converted directly to the corresponding aldehydes with remarkable chemoselectivity. Primary and secondary amides proved to be viable substrates for reduction as well, although the yields were somewhat diminished compared to the corresponding tertiary amides. Results from NMR experiments suggested the presence of a stable, 18-electron zirconacycle intermediate that presumably affords the aldehyde upon water or silica gel workup. A series of competition experiments revealed a preference of the reagent for substrates in which the lone pair of the nitrogen is electron releasing and thus more delocalized across the amide bond by resonance. This trend accounts for the observed excellent selectivity for tertiary amides versus esters. Experiments regarding the solvent dependence of the reaction suggested a kinetic profile similar to that postulated for the hydrozirconation of alkenes and alkynes. Addition of p-anisidine to the reaction intermediate resulted in the formation of the corresponding imine mimicking the addition of water that forms the aldehyde. PMID:17315870

FACTORS CONTROLLING THE EMISSIONS OF MONOTERPENES AND OTHER VOLATILE ORGANIC COMPOUNDS

EPA Science Inventory

Plants contain a number of volatile organic compounds, including isoprene, mono- and sesquiterpenes, alcohols, aldehydes, ketones, and esters. ndividual plant species have unique combinations of these compounds; consequently, the emission pattern for each species is also specific...

Copper-Catalyzed Alkoxycarbonylation of Alkanes with Alcohols.

PubMed

Li, Yahui; Wang, Changsheng; Zhu, Fengxiang; Wang, Zechao; Dixneuf, Pierre H; Wu, Xiao-Feng

2017-04-10

Esters are important chemicals widely used in various areas, and alkoxycarbonylation represents one of the most powerful tools for their synthesis. In this communication, a new copper-catalyzed carbonylative procedure for the synthesis of aliphatic esters from cycloalkanes and alcohols was developed. Through direct activation of the Csp3 -H bond of alkanes and with alcohols as the nucleophiles, the desired esters were prepared in moderate-to-good yields. Paraformaldehyde could also be applied for in situ alcohol generation by radical trapping, and moderate yields of the corresponding esters could be produced. Notably, this is the first report on copper-catalyzed alkoxycarbonylation of alkanes. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Silica gel promotes reductions of aldehydes and ketones by N-heterocyclic carbene boranes.

PubMed

Taniguchi, Tsuyoshi; Curran, Dennis P

2012-09-07

N-Heterocyclic carbene boranes (NHC-boranes) such as 1,3-dimethylimidazol-2-ylidine trihydridoborane (diMe-Imd-BH(3)) serve as practical hydride donors for the reduction of aldehydes and ketones in the presence of silica gel. Primary and secondary alcohols are formed in good yields under ambient conditions. Aldehydes are selectively reduced in the presence of ketones. One, two, or even all three of the boron hydrides can be transferred. The process is attractive because all the components are stable and easy to handle and because both the reaction and isolation procedures are convenient.

Metabolic engineering of Saccharomyces cerevisiae for production of fatty acid short- and branched-chain alkyl esters biodiesel.

PubMed

Teo, Wei Suong; Ling, Hua; Yu, Ai-Qun; Chang, Matthew Wook

2015-01-01

Biodiesel is a mixture of fatty acid short-chain alkyl esters of different fatty acid carbon chain lengths. However, while fatty acid methyl or ethyl esters are useful biodiesel produced commercially, fatty acid esters with branched-chain alcohol moieties have superior fuel properties. Crucially, this includes improved cold flow characteristics, as one of the major problems associated with biodiesel use is poor low-temperature flow properties. Hence, microbial production as a renewable, nontoxic and scalable method to produce fatty acid esters with branched-chain alcohol moieties from biomass is critical. We engineered Saccharomyces cerevisiae to produce fatty acid short- and branched-chain alkyl esters, including ethyl, isobutyl, isoamyl and active amyl esters using endogenously synthesized fatty acids and alcohols. Two wax ester synthase genes (ws2 and Maqu_0168 from Marinobacter sp.) were cloned and expressed. Both enzymes were found to catalyze the formation of fatty acid esters, with different alcohol preferences. To boost the ability of S. cerevisiae to produce the aforementioned esters, negative regulators of the INO1 gene in phospholipid metabolism, Rpd3 and Opi1, were deleted to increase flux towards fatty acyl-CoAs. In addition, five isobutanol pathway enzymes (Ilv2, Ilv5, Ilv3, Aro10, and Adh7) targeted into the mitochondria were overexpressed to enhance production of alcohol precursors. By combining these engineering strategies with high-cell-density fermentation, over 230 mg/L fatty acid short- and branched-chain alkyl esters were produced, which is the highest titer reported in yeast to date. In this work, we engineered the metabolism of S. cerevisiae to produce biodiesels in the form of fatty acid short- and branched-chain alkyl esters, including ethyl, isobutyl, isoamyl and active amyl esters. To our knowledge, this is the first report of the production of fatty acid isobutyl and active amyl esters in S. cerevisiae. Our findings will be useful for

Highly stereoselective three-component reactions of phenylselenomagnesium bromide, acetylenic sulfones, and saturated aldehydes/ketones or alpha,beta-unsaturated enals or enones.

PubMed

Huang, Xian; Xie, Meihua

2002-12-13

beta-Phenylseleno-alpha-tolylsulfonyl-substituted alkenes were synthesized via the three-component conjugate-nucleophilic addition of acetylenic sulfones, phenylselenomagnesium bromide, and carbonyl compounds, such as aldehydes, aliphatic ketones, or alpha,beta-unsaturated enals or enones. The reaction is highly regio- and stereoselective with moderate to good yields. Functionalized allylic alcohols were obtained in the case of aldehydes and aliphatic ketones. In the case of alpha,beta-unsaturated enones, functionalized allylic alcohols or functionalized gamma,delta-unsaturated ketones were obtained, depending on the structures of the ketones.

Sweet little Gabonese palm wine: a neglected alcohol.

PubMed

Mavioga, E M; Mullot, J U; Frederic, C; Huart, B; Burnat, P

2009-01-01

During the last ten years, consumption of palm wine, a popular traditional alcoholic beverage, seriously increases in Gabon. This sweet beverage seems to be the main alcohol and the most drunken in low socioeconomic population. To have an idea of its composition and toxicity, 21 samples of palm wine were collected in the country and analysed. Twenty-one palm wine samples were randomly selected from all over Gabon. Methanol and ethanol concentrations in the samples were measured by gas chromatography. Aromatic hydrocarbons were measured by selected ion monitoring mode in mass spectrometry. Delection of heavy metals was by standard techniques. Gabonese palm wine contained ethanol at a mean concentration of about 60 g*L-1, i.e. 7.5 degrees (volume %), volatile components such as alcohols, aldehydes, carboxylic acids and esters and trace metals. Trace metals were present at low concentrations below internationally recognized maximal limits for alcoholic beverages with less than 2 microg*L-1 for cadmium, less than 10 microg*L-1 for arsenic and for lead 15 samples with concentrations under 10 microg*L-1 and the last six samples with concentrations between 11 and 61 microg*L-1. None of the searched aromatic or chlorinated solvents, indicative of refined fuel or industrial contamination, was detected. For the parameters analyzed here, there seems to be no significant difference in constitution between Gabonese wine palm and others kind of palm wine produced in West Africa. This alcohol needs to be more considered by public health authorities and medical teams because of its health and economic consequences.

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.

Process for the synthesis of unsaturated alcohols

DOEpatents

Maughon, Bob R.; Burdett, Kenneth A.; Lysenko, Zenon

2007-02-13

A process of preparing an unsaturated alcohol (olefin alcohol), such as, a homo-allylic mono-alcohol or homo-allylic polyol, involving protecting a hydroxy-substituted unsaturated fatty acid or fatty acid ester, such as methyl ricinoleate, derived from a seed oil, to form a hydroxy-protected unsaturated fatty acid or fatty acid ester; homo-metathesizing or cross-metathesizing the hydroxy-protected unsaturated fatty acid or fatty acid ester to produce a product mixture containing a hydroxy-protected unsaturated metathesis product; and deprotecting the hydroxy-protected unsaturated metathesis product under conditions sufficient to prepare the unsaturated alcohol. Preferably, methyl ricinoleate is converted by cross-metathesis or homo-metathesis into the homo-allylic mono-alcohol 1-decene-4-ol or the homo-allylic polyol 9-octadecene-7,12-diol, respectively.

Metal-free catalytic enantioselective C-B bond formation: (pinacolato)boron conjugate additions to α,β-unsaturated ketones, esters, Weinreb amides, and aldehydes promoted by chiral N-heterocyclic carbenes.

PubMed

Wu, Hao; Radomkit, Suttipol; O'Brien, Jeannette M; Hoveyda, Amir H

2012-05-16

The first broadly applicable metal-free enantioselective method for boron conjugate addition (BCA) to α,β-unsaturated carbonyls is presented. The C-B bond forming reactions are promoted in the presence of 2.5-7.5 mol % of a readily accessible C(1)-symmetric chiral imidazolinium salt, which is converted, in situ, to the catalytically active diastereo- and enantiomerically pure N-heterocyclic carbene (NHC) by the common organic base 1,8-diazabicyclo[5.4.0]undec-7-ene (dbu). In addition to the commercially available bis(pinacolato)diboron [B(2)(pin)(2)], and in contrast to reactions with the less sterically demanding achiral NHCs, the presence of MeOH is required for high efficiency. Acyclic and cyclic α,β-unsaturated ketones, as well as acyclic esters, Weinreb amides, and aldehydes, can serve as suitable substrates; the desired β-boryl carbonyls are isolated in up to 94% yield and >98:2 enantiomer ratio (er). Transformations are often carried out at ambient temperature. In certain cases, such as when the relatively less reactive unsaturated amides are used, elevated temperatures are required (50-66 °C); nonetheless, reactions remain highly enantioselective. The utility of the NHC-catalyzed method is demonstrated through comparison with the alternative Cu-catalyzed protocols; in cases involving a polyfunctional substrate, unique profiles in chemoselectivity are exhibited by the metal-free approach (e.g., conjugate addition vs reaction with an alkyne, allene, or aldehyde).

Metal-Free Catalytic Enantioselective C–B Bond Formation: (Pinacolato)boron Conjugate Additions to α,β-Unsaturated Ketones, Esters, Weinreb Amides and Aldehydes Promoted by Chiral N-Heterocyclic Carbenes

PubMed Central

Wu, Hao; Radomkit, Suttipol; O’Brien, Jeannette M.; Hoveyda, Amir H.

2012-01-01

The first broadly applicable metal-free enantioselective method for boron conjugate addition (BCA) to α,β-unsaturated carbonyls is presented. The C–B bond forming reactions are promoted in the presence of 2.5–7.5 mol % of a readily accessible C1-symmetric chiral imidazolinium salt, which is converted, in situ, to the catalytically active diastereo- and enantiomerically pure N-heterocyclic carbene (NHC) by the common organic base 1,8-diazabicyclo[5.4.0]undec-7-ene (dbu). In addition to the commercially available bis(pinacolato)diboron [B2(pin)2], and in contrast to reactions with the less sterically demanding achiral NHCs, the presence of MeOH is required for high efficiency. Acyclic and cyclic α,β-unsaturated ketones, as well as acyclic esters, Weinreb amides and aldehydes can serve as suitable substrates; the desired β-boryl carbonyls are isolated in up to 94% yield and >98:2 enantiomer ratio (er). Transformations are often carried out at ambient temperature. In certain cases, such as when the relatively less reactive unsaturated amides are used, elevated temperatures are required (50–66 °C); nonetheless, reactions remain highly enantioselective. The utility of the NHC-catalyzed method is demonstrated through comparison with the alternative Cu-catalyzed protocols; in cases involving a polyfunctional substrate, unique profiles in chemoselectivity are exhibited by the metal-free approach (e.g., conjugate addition vs reaction with an alkyne, allene or aldehyde). PMID:22559866

Wax ester profiling of seed oil by nano-electrospray ionization tandem mass spectrometry

PubMed Central

2013-01-01

Background Wax esters are highly hydrophobic neutral lipids that are major constituents of the cutin and suberin layer. Moreover they have favorable properties as a commodity for industrial applications. Through transgenic expression of wax ester biosynthetic genes in oilseed crops, it is possible to achieve high level accumulation of defined wax ester compositions within the seed oil to provide a sustainable source for such high value lipids. The fatty alcohol moiety of the wax esters is formed from plant-endogenous acyl-CoAs by the action of fatty acyl reductases (FAR). In a second step the fatty alcohol is condensed with acyl-CoA by a wax synthase (WS) to form a wax ester. In order to evaluate the specificity of wax ester biosynthesis, analytical methods are needed that provide detailed wax ester profiles from complex lipid extracts. Results We present a direct infusion ESI-tandem MS method that allows the semi-quantitative determination of wax ester compositions from complex lipid mixtures covering 784 even chain molecular species. The definition of calibration prototype groups that combine wax esters according to their fragmentation behavior enables fast quantitative analysis by applying multiple reaction monitoring. This provides a tool to analyze wax layer composition or determine whether seeds accumulate a desired wax ester profile. Besides the profiling method, we provide general information on wax ester analysis by the systematic definition of wax ester prototypes according to their collision-induced dissociation spectra. We applied the developed method for wax ester profiling of the well characterized jojoba seed oil and compared the profile with wax ester-accumulating Arabidopsis thaliana expressing the wax ester biosynthetic genes MaFAR and ScWS. Conclusions We developed a fast profiling method for wax ester analysis on the molecular species level. This method is suitable to screen large numbers of transgenic plants as well as other wax ester samples

VOLATILE ORGANIC CHEMICALS IN 10 PUBLIC-ACCESS BUILDINGS

EPA Science Inventory

The U.S. EPA carried out studies of indoor air quality in 10 buildings. Qualitative analysis identified over 200 aromatics, halogens, esters, alcohols, phenols, ethers, ketones, aldehydes, and epoxides, in addition to several hundred aliphatic hydrocarbons. The total organic load...

TiO2 supported gold nanoparticles: An efficient photocatalyst for oxidation of alcohol to aldehyde and ketone in presence of visible light irradiation

NASA Astrophysics Data System (ADS)

Gogoi, Nibedita; Borah, Geetika; Gogoi, Pradip K.; Chetia, Tridip Ranjan

2018-01-01

An efficient heterogeneous photocatalyst composed of Au nanoparticle supported on TiO2 (anatase) is prepared by sol-gel method. This prepared nanocomposite showed good catalytic activity in the oxidation of various alcohols to aldehyde and ketone under irradiation of visible light. Various spectroscopic techniques including UV-Visible absorption spectral studies and photoluminescence study are employed to characterize the catalyst. It was also characterized by XRD, TEM, BET, XPS and ICP-AES analysis. In contrast to air and H2O2, use of TBHP as oxidant gave good yield. The reaction conditions with respect to solvent and amount of catalyst are optimized.

Volatile components of the enzyme-ripened sufu, a Chinese traditional fermented product of soy bean.

PubMed

Moy, Yin-Soon; Lu, Ting-Jang; Chou, Cheng-Chun

2012-02-01

In the present study, sufu, a soft cheese-like oriental fermented food, was prepared by ripening the salted-tofu cubes in Aspergillus oryzae-fermented soybean-rice koji at 37°C for 16 days (16-day sufu). Sufu was further held at room temperature for another 30 days (46-day sufu). The volatile components of the non-fermented tofu cubes and the sufu products were identified and quantified by GC and GC-MS. A total of 70 volatile compounds including 20 aldehydes, 18 alcohols, 16 esters, 5 ketones, 5 acids and 6 other compounds were identified. Sufu products contained more volatile compounds than non-fermented tofu cubes qualitatively and quantitatively. After 16-days of ripening, fatty acid, aldehyde and ester were noted to be the dominant volatile fractions. In contrast, the 46-day sufu contained ester, and alcohol as the major volatile fractions. They comprise approximately 63.9% of the total volatile components. Copyright © 2011 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Inhibition effects of furfural on alcohol dehydrogenase, aldehyde dehydrogenase and pyruvate dehydrogenase.

PubMed Central

Modig, Tobias; Lidén, Gunnar; Taherzadeh, Mohammad J

2002-01-01

The kinetics of furfural inhibition of the enzymes alcohol dehydrogenase (ADH; EC 1.1.1.1), aldehyde dehydrogenase (AlDH; EC 1.2.1.5) and the pyruvate dehydrogenase (PDH) complex were studied in vitro. At a concentration of less than 2 mM furfural was found to decrease the activity of both PDH and AlDH by more than 90%, whereas the ADH activity decreased by less than 20% at the same concentration. Furfural inhibition of ADH and AlDH activities could be described well by a competitive inhibition model, whereas the inhibition of PDH was best described as non-competitive. The estimated K(m) value of AlDH for furfural was found to be about 5 microM, which was lower than that for acetaldehyde (10 microM). For ADH, however, the estimated K(m) value for furfural (1.2 mM) was higher than that for acetaldehyde (0.4 mM). The inhibition of the three enzymes by 5-hydroxymethylfurfural (HMF) was also measured. The inhibition caused by HMF of ADH was very similar to that caused by furfural. However, HMF did not inhibit either AlDH or PDH as severely as furfural. The inhibition effects on the three enzymes could well explain previously reported in vivo effects caused by furfural and HMF on the overall metabolism of Saccharomyces cerevisiae, suggesting a critical role of these enzymes in the observed inhibition. PMID:11964178

Fluorescence method for enzyme analysis which couples aromatic amines with aromatic aldehydes

DOEpatents

Smith, R.E.; Dolbeare, F.A.

1980-10-21

Analysis of proteinases is accomplished using conventional amino acid containing aromatic amine substrates. Aromatic amines such as 4-methoxy-2-naphthylamine (4M2NA), 2-naphthylamine, aminoisophthalic acid dimethyl ester, p-nitroaniline, 4-methoxy-1-aminofluorene and coumarin derivatives resulting from enzymatic hydrolysis of the substrate couples with aromatic aldehydes such as 5-nitrosalicylaldehyde (5-NSA), benzaldehyde and p-nitrobenzaldehyde to produce Schiff-base complexes which are water insoluble. Certain Schiff-base complexes produce a shift from blue to orange-red (visible) fluorescence. Such complexes are useful in the assay of enzymes. No Drawings

Fluorescence method for enzyme analysis which couples aromatic amines with aromatic aldehydes

DOEpatents

Smith, Robert E. [557 Escondido Cir., Livermore, CA 94550; Dolbeare, Frank A. [5178 Diane La., Livermore, CA 94550

1980-10-21

Analysis of proteinases is accomplished using conventional amino acid containing aromatic amine substrates. Aromatic amines such as 4-methoxy-2-naphthylamine (4M2NA), 2-naphthylamine, aminoisophthalic acid dimethyl ester, p-nitroaniline, 4-methoxy-1-aminofluorene and coumarin derivatives resulting from enzymatic hydrolysis of the substrate couples with aromatic aldehydes such as 5-nitrosalicylaldehyde (5-NSA), benzaldehyde and p-nitrobenzaldehyde to produce Schiff-base complexes which are water insoluble. Certain Schiff-base complexes produce a shift from blue to orange-red (visible) fluorescence. Such complexes are useful in the assay of enzymes.

Fluorescence method for enzyme analysis which couples aromatic amines with aromatic aldehydes

DOEpatents

Smith, Robert E.; Dolbeare, Frank A.

1979-01-01

Analysis of proteinases is accomplished using conventional amino acid containing aromatic amine substrates. Aromatic amines such as 4-methoxy-2-naphthylamine (4M2NA), 2-naphthylamine, aminoisophthalic acid dimethyl ester, p-nitroaniline, 5-methoxy-1-aminofluorene and coumarin derivatives resulting from enzymatic hydrolysis of the substrate couples with aromatic aldehydes such as 5-nitrosalicylaldehyde (5-NSA), benzaldehyde and p-nitrobenzaldehyde to produce Schiff-base complexes which are water insoluble. Certain Schiff-base complexes produce a shift from blue to orange-red (visible) fluorescence. Such complexes are useful in the assay of enzymes.

Pretreatment of industrial wastewater containing phthalate esters by centrifugation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Petrosky, C.J.; Vidic, R.D.

1996-11-01

In this study, a full-scale commercial centrifuge was used to treat, on a continuous basis, the entire wastewater stream generated by a chemical manufacturing facility which produces a variety of phthalate, adipate, maleate, and trimellitate esters. The wastewater from this facility is comprised of process water, equipment was water, and rain water runoff containing varying concentrations of bis(2-ethylhexyl) phthalate (BEHP), di-n-octyl phthalate (DNOP), and di-n-butyl phthalate (DNBP) esters in addition to mono-ester salts and alcohols. The wastewater is discharged to the local Publicly Owned Treatment Works (POTW) under pretreatment regulations which specify an effluent limitation of 5.0 mg/L on themore » total toxic organic (TTO) concentration which can be placed on the combined BEHP, DNOP, and DNBP ester concentration. Various esters and long chain alcohols present in the wastewater have very low water solubilities and are considered immiscible. They form a dispersed phase in the wastewater that has a specific gravity in the range of 0.88 to 0.93. Separation of the dispersed phase containing the regulated esters from the heavier water phase to consistently below 5.0 mg/L poses a challenge due to the stability of this colloidal suspension. The objective of this study was to evaluate the effectiveness of centrifugation in meeting the 5.0 mg/L effluent limit on the total BEHP, DNOP, and DNBP ester concentration.« less

Selective Oxidative Esterification from Two Different Alcohols via Photoredox Catalysis.

PubMed

Yi, Hong; Hu, Xia; Bian, Changliang; Lei, Aiwen

2017-01-10

Esters functionalities are important building blocks that are extensively used in the chemical industry and academic laboratories. Direct oxidative esterification from easy-available alcohols to esters would be a much more appealing approach, especially using O 2 as terminal oxidant. Inputting external energy by photocatalysis for dioxygen activation, a mild and simple method for ester synthesis from two different alcohols has been achieved in this work. This reaction is performed under neutral conditions using O 2 as the terminal oxidant. A variety of primary alcohols, especially long chain alcohols and secondary alcohols are tolerated in this system. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Agreement between the fatty acid ethyl ester hair test for alcohol and social workers' reports.

PubMed

Kulaga, Vivian; Gareri, Joey; Fulga, Netta; Koren, Gideon

2010-06-01

The purpose of this study was to examine the relationship between social worker reports and the fatty acid ethyl ester (FAEE) test as a biomarker for heavy alcohol use. In 2005, a diagnostic program to detect excessive alcohol use by FAEE hair analysis in parents at high risk of having children with fetal alcohol spectrum disorders was established. All cases submitted by Child Protective Services between May and December of 2007 (n = 172) were included comparing social worker reports with FAEE test outcome by odds ratio analysis. A subanalysis of mothers (n = 119), excluding fathers, was also performed. Factors associated with testing positive for hair FAEE in parents, and mothers alone, were: knowledge of a specific instance of problem drinking within the past 6 months (odds ratio [OR] = 5.11, 2.57-10.16 and OR = 8.51, 3.59-20.18, respectively) and third party reports alleging alcohol abuse (OR = 3.31, 1.69-6.46 and OR = 3.30, 1.45-7.50, respectively). Mothers who admitted to heavy drinking were also seven times more likely to test positive for hair FAEE (OR = 6.74, 1.50-30.38) than those who did not. Factors negatively associated with testing positive for hair FAEE in parents, and mothers alone, were: social workers testing for FAEE without the suspicion of alcohol use but rather as a measure to "cover all bases" (OR = 0.09, 0.02-0.40 and (OR = 0.13, 0.03-0.58, respectively) or because of a history/suspicion of illicit drug use (OR = 0.2, 0.07-0.55 and OR = 0.26, 0.08-0.80, respectively). Eleven of 15 reports, indicating levels of consumption, were also in clinical agreement with FAEE test outcome. The FAEE hair test is being applied for the first time in the present context. Our results show the test corroborates well with social workers' suspicion of alcohol use. Reported factors directly related to alcohol use were significantly associated with testing positive for excessive alcohol use, whereas factors not directly related to alcohol use were negatively

Volatile constituents of commercial imported and domestic black-ripe table olives (Olea europaea)

USDA-ARS?s Scientific Manuscript database

Volatile constituents of commercial black-ripe table olives (Olea europaea) from the United States, Spain, Egypt and Morocco were analyzed by gas chromatography and gas chromatography-mass spectrometry (GC-MS). Dynamic headspace sampling was used to isolate a variety of aldehydes, alcohols, esters, ...

Increased production of wax esters in transgenic tobacco plants by expression of a fatty acid reductase:wax synthase gene fusion.

PubMed

Aslan, Selcuk; Hofvander, Per; Dutta, Paresh; Sun, Chuanxin; Sitbon, Folke

2015-12-01

Wax esters are hydrophobic lipids consisting of a fatty acid moiety linked to a fatty alcohol with an ester bond. Plant-derived wax esters are today of particular concern for their potential as cost-effective and sustainable sources of lubricants. However, this aspect is hampered by the fact that the level of wax esters in plants generally is too low to allow commercial exploitation. To investigate whether wax ester biosynthesis can be increased in plants using transgenic approaches, we have here exploited a fusion between two bacterial genes together encoding a single wax ester-forming enzyme, and targeted the resulting protein to chloroplasts in stably transformed tobacco (Nicotiana benthamiana) plants. Compared to wild-type controls, transgenic plants showed both in leaves and stems a significant increase in the total level of wax esters, being eight-fold at the whole plant level. The profiles of fatty acid methyl ester and fatty alcohol in wax esters were related, and C16 and C18 molecules constituted predominant forms. Strong transformants displayed certain developmental aberrations, such as stunted growth and chlorotic leaves and stems. These negative effects were associated with an accumulation of fatty alcohols, suggesting that an adequate balance between formation and esterification of fatty alcohols is crucial for a high wax ester production. The results show that wax ester engineering in transgenic plants is feasible, and suggest that higher yields may become achieved in the near future.

HEPATOCYTE EXPRESION OF TUMOR ASSOCIATED ALDEHYDE DEHYDROGENASE (ALDH-3) AND P21 RAS FOLLOWING DIETHYLNITROSAMINE (DEN) INITIATION AND CHRONIC EXPOSURE TO DI(2-ETHYLHEXYL) PHTHALATE (DHEP)

EPA Science Inventory

Phthalate esters such as di(2-ethylhexyl)phthalate (DEHP)either promote or inhibit rat liver tumorigenesis depending on the carcinogenesis protocol. In this study, we examined the expression of two histochemical markers, the tumor associated isozyme of aldehyde dehydrogenase (ALD...

Isolation and identification of an ester from a crude oil

USGS Publications Warehouse

Phillips, H.F.; Breger, I.A.

1958-01-01

A dioctylphthalate has been isolated from a crude oil by means of adsorption column chromatography. The ester was identified by means of elemental analysis, refractive index, and its infra-red absorption spectrum. Saponification of the isolate and examination of the resultant alcohol by means of infrared absorption spectra led to the conclusion that the ester is a branched chain dioctylphthalate. This is the first reported occurrence of an ester in crude petroleum. ?? 1958.

Aldehyde dedydrogenase-2 plays a beneficial role in ameliorating chronic alcohol-induced hepatic steatosis and inflammation through regulation of autophagy.

PubMed

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

2015-03-01

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. Wild type Friend 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 signalling were examined. The role of autophagy was evaluated in alcohol dehydrogenase 1 (ADH1)-transfected human hepatocellular liver carcinoma cells (VA-13) treated with or without the autophagy inducer rapamycin and lysosomal inhibitors. Chronic alcohol intake led to elevated AST-, ALT-levels, bilirubin, AST/ALT ratio, cholesterol, hepatic triglycerides and hepatic fat deposition as evidenced by H&E and Oil Red O staining. Hepatic fat deposition was associated with disturbed levels of fat metabolism-related proteins (fatty acid synthase, SCD1), upregulated interleukin-6, TNF-α, cyclooxygenase, oxidative stress, and loss of autophagy, effects which were attenuated or ablated by the ALDH2 transgene. Moreover, ethanol (100 mM) and acetaldehyde (100 and 500 μM) increased levels of IL-6 and IFN-γ, and suppressed autophagy in VA-13 cells, effects 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. 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. Copyright © 2014 European Association for the Study of the Liver

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.

Methods of refining and producing dibasic esters and acids from natural oil feedstocks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Snead, Thomas E; Cohen, Steven A; Gildon, Demond L

2015-04-07

Methods are provided for refining natural oil feedstocks and producing dibasic esters and/or dibasic acids. The methods comprise reacting a terminal olefin with an internal olefin in the presence of a metathesis catalyst to form a dibasic ester and/or dibasic acid. In certain embodiments, the olefin esters are formed by reacting the feedstock in the presence of a metathesis catalyst under conditions sufficient to form a metathesized product comprising olefins and esters, separating the olefins from the esters in the metathesized product, and transesterifying the esters in the presence of an alcohol to form a transesterified product having olefin esters.

Methods of refining and producing dibasic esters and acids from natural oil feedstocks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Snead, Thomas E.; Cohen, Steven A.; Gildon, Demond L.

2016-03-15

Methods are provided for refining natural oil feedstocks and producing dibasic esters and/or dibasic acids. The methods comprise reacting a terminal olefin with an internal olefin in the presence of a metathesis catalyst to form a dibasic ester and/or dibasic acid. In certain embodiments, the olefin esters are formed by reacting the feedstock in the presence of a metathesis catalyst under conditions sufficient to form a metathesized product comprising olefins and esters, separating the olefins from the esters in the metathesized product, and transesterifying the esters in the presence of an alcohol to form a transesterified product having olefin esters.

Aldehyde Oxidase 4 Plays a Critical Role in Delaying Silique Senescence by Catalyzing Aldehyde Detoxification.

PubMed

Srivastava, Sudhakar; Brychkova, Galina; Yarmolinsky, Dmitry; Soltabayeva, Aigerim; Samani, Talya; Sagi, Moshe

2017-04-01

The Arabidopsis ( Arabidopsis thaliana ) aldehyde oxidases are a multigene family of four oxidases (AAO1-AAO4) that oxidize a variety of aldehydes, among them abscisic aldehyde, which is oxidized to the phytohormone abscisic acid. Toxic aldehydes are generated in plants both under normal conditions and in response to stress. The detoxification of such aldehydes by oxidation is attributed to aldehyde dehydrogenases but never to aldehyde oxidases. The feasibility of the detoxification of aldehydes in siliques via oxidation by AAO4 was demonstrated, first, by its ability to efficiently oxidize an array of aromatic and aliphatic aldehydes, including the reactive carbonyl species (RCS) acrolein, hydroxyl-2-nonenal, and malondialdehyde. Next, exogenous application of several aldehydes to siliques in AAO4 knockout (KO) Arabidopsis plants induced severe tissue damage and enhanced malondialdehyde levels and senescence symptoms, but not in wild-type siliques. Furthermore, abiotic stresses such as dark and ultraviolet C irradiation caused an increase in endogenous RCS and higher expression levels of senescence marker genes, leading to premature senescence of KO siliques, whereas RCS and senescence marker levels in wild-type siliques were hardly affected. Finally, in naturally senesced KO siliques, higher endogenous RCS levels were associated with enhanced senescence molecular markers, chlorophyll degradation, and earlier seed shattering compared with the wild type. The aldehyde-dependent differential generation of superoxide and hydrogen peroxide by AAO4 and the induction of AAO4 expression by hydrogen peroxide shown here suggest a self-amplification mechanism for detoxifying additional reactive aldehydes produced during stress. Taken together, our results indicate that AAO4 plays a critical role in delaying senescence in siliques by catalyzing aldehyde detoxification. © 2017 American Society of Plant Biologists. All Rights Reserved.

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. Copyright © 2015 Elsevier B.V. All rights reserved.

Hydride transfer made easy in the oxidation of alcohols catalyzed by choline oxidase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gadda, G.; Orville, A.; Pennati, A.

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 sitemore » 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.« less

Effects of Schiff Base Formation and Aldol Condensation on the Determination of Aldehydes in Rice Wine Using GC-MS.

PubMed

Han, Ji Hye; Lee, Sang Mi; Kim, Young-Suk

2017-04-11

The Schiff base reaction and aldol condensation that occur during sample preparation can lead to the reduction of aldehyde content in the analysis of traditional Korean rice wine, makgeolli. The contents of aldehydes were decreased, whereas those of hydroxy carbonyl compounds were increased by increasing the pH. In the presence of added amino acids, the levels of aldehydes in makgeolli were reduced as the amount of the amino acid alanine increased. Also, the contents of hydroxyl carbonyl compounds were reduced by alanine addition as compared to the control. Therefore, the determination of aldehydes can be affected by pH and the amount of amino acids, which can vary during fermentation and storage of alcoholic beverages because pH and amino acids affect Schiff base formation and aldol condensation.

Lipase-catalysed esters synthesis of cafestol and kahweol.

PubMed

Novaes, Fábio Junior Moreira; Itabaiana Junior, Ivaldo; Sutili, Felipe Korbus; Marriott, Philip John; Bizzo, Humberto Ribeiro; Aquino Neto, Francisco Radler de; Souza, Rodrigo Octávio Mendonça Alves de; Rezende, Claudia Moraes

2018-09-01

Cafestol and kahweol (C&K), two coffee diterpene alcohols with structural similarity which exhibit anticarcinogenic effects, were isolated from green coffee Arabica beans, followed by their lipase-catalysed esterification and purification by preparative high-performance liquid chromatography (HPLC). The isolation and enzymatic synthesis parameters of C&K esters were studied, with the latter optimised by a Central Composite Design; both procedures were monitored by gas chromatography. Scale up and improved isolation conditions resulted in 1.29 g of C&K, with 98% purity from 300 g of green Arabica beans. The highest C&K ester yields were observed using an alcohol:fatty acid molar ratio of 1:5, 73.3 mg mL -1 of CAL-B enzyme, 70 °C and 240 rpm for 3 days in toluene, leading to 85-88% conversion among a variety of tested C&K esters, including n-C 14:0 -C 20:0 , C 18:1 , C 18:2 and C 18:3 . Copyright © 2018. Published by Elsevier Ltd.

[Analysis of constituents of ester-type gum bases used as natural food additives].

PubMed

Tada, Atsuko; Masuda, Aino; Sugimoto, Naoki; Yamagata, Kazuo; Yamazaki, Takeshi; Tanamoto, Kenichi

2007-12-01

The differences in the constituents of ten ester-type gum bases used as natural food additives in Japan (urushi wax, carnauba wax, candelilla wax, rice bran wax, shellac wax, jojoba wax, bees wax, Japan wax, montan wax, and lanolin) were investigated. Several kinds of gum bases showed characteristic TLC patterns of lipids. In addition, compositions of fatty acid and alcohol moieties of esters in the gum bases were analyzed by GC/MS after methanolysis and hydrolysis, respectively. The results indicated that the varieties of fatty acids and alcohols and their compositions were characteristic for each gum base. These results will be useful for identification and discrimination of the ester-type gum bases.

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.

Synthesis and characterization of ester and amide derivatives of titanium(IV) carboxymethylphosphonate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Melánová, Klára, E-mail: klara.melanova@upce.cz; Beneš, Ludvík; Trchová, Miroslava

2013-06-15

A set of layered ester and amide derivatives of titanium(IV) carboxymethylphosphonate was prepared by solvothermal treatment of amorphous titanium(IV) carboxymethylphosphonate with corresponding 1-alkanols, 1,ω-alkanediols, 1-aminoalkanes, 1,ω-diaminoalkanes and 1,ω-amino alcohols and characterized by powder X-ray diffraction, IR spectroscopy and thermogravimetric analysis. Whereas alkyl chains with one functional group form bilayers tilted to the layers, 1,ω-diaminoalkanes and most of 1,ω-alkanediols form bridges connecting the adjacent layers. In the case of amino alcohols, the alkyl chains form bilayer and either hydroxyl or amino group is used for bonding. This simple method for the synthesis of ester and amide derivatives does not require preparationmore » of acid chloride derivative as a precursor or pre-intercalation with alkylamines and can be used also for the preparation of ester and amide derivatives of titanium carboxyethylphosphonate and zirconium carboxymethylphosphonate. - Graphical abstract: Ester and amide derivatives of layered titanium carboxymethylphosphonate were prepared by solvothermal treatment of amorphous solid with alkanol or alkylamine. - Highlights: • Ester and amide derivatives of titanium carboxymethylphosphonate. • Solvothermal treatment of amorphous solid with alkanol or alkylamine. • Ester and amide formation confirmed by IR spectroscopy.« less

The antifungal activity of the cuticular and internal fatty acid methyl esters and alcohols in Calliphora vomitoria.

PubMed

Gołębiowski, Marek; Cerkowniak, Magdalena; Dawgul, Małgorzata; Kamysz, Wojciech; Boguś, Mieczysława I; Stepnowski, Piotr

2013-07-01

SUMMARY The composition of the fatty acid methyl ester (FAME) and alcohol fractions of the cuticular and internal lipids of Calliphora vomitoria larvae, pupae and male/female adults was obtained by separating these two fractions by HPLC-LLSD and analysing them quantitatively using GC-MS. Analysis of the cuticular lipids of the worldwide, medically important ectoparasite C. vomitoria revealed 6 FAMEs with odd-numbered carbon chains from C15:0 to C19:0 in the larvae, while internal lipids contained 9 FAMEs ranging from C15:1 to C19:0. Seven FAMEs from C15:0 to C19:0 were identified in the cuticular lipids of the pupae, whereas the internal lipids of the pupae contained 10 FAMEs from C13:0 to C19:0. The cuticular lipids of males and females and also the internal lipids of males contained 5, 7 and 6 FAMEs from C15:0 to C19:0 respectively. Seven FAMEs from C13:0 to C19:0 were identified in the internal lipids of females, and 7, 6, 5 and 3 alcohols were found in the cuticular lipids of larvae, pupae, males and females respectively. Only saturated alcohols with even-numbered carbon chains were present in these lipids. Only 1 alcohol (C22:0) was detected in the internal lipids of C. vomitoria larvae, while just 4 alcohols from - C18:0 to C24:0 - were identified in the internal lipids of pupae, and males and females. We also identified glycerol and cholesterol in the larvae, pupae, males and females of C. vomitoria. The individual alcohols and FAMEs, as well as their mixtures isolated from the cuticular and internal lipids of larvae, pupae, males and females of C. vomitoria, demonstrated antimicrobial activity against entomopathogenic fungi.

Allyl transfer to aldehydes and ketones by Brønsted acid activation of allyl and crotyl 1,3,2-dioxazaborolidines.

PubMed

Reilly, Maureen K; Rychnovsky, Scott D

2010-11-05

Alkyl dioxazaborolidines are air-stable and often crystalline organoboranes. A variety of Brønsted acids activate allyl dioxazaborolidines to generate reactive allyl-transfer reagents in situ. These reagents add to aldehydes and ketones to generate the corresponding alcohols in good yields under mild conditions. The E- and Z-crotyl reagents react diastereoselectively with aldehydes and ketones to produce anti and syn adducts, respectively, a result consistent with a cyclic transition state (type I mechanism).

Identification of the Wax Ester Synthase/Acyl-Coenzyme A:Diacylglycerol Acyltransferase WSD1 Required for Stem Wax Ester Biosynthesis in Arabidopsis12[W][OA

PubMed Central

Li, Fengling; Wu, Xuemin; Lam, Patricia; Bird, David; Zheng, Huanquan; Samuels, Lacey; Jetter, Reinhard; Kunst, Ljerka

2008-01-01

Wax esters are neutral lipids composed of aliphatic alcohols and acids, with both moieties usually long-chain (C16 and C18) or very-long-chain (C20 and longer) carbon structures. They have diverse biological functions in bacteria, insects, mammals, and terrestrial plants and are also important substrates for a variety of industrial applications. In plants, wax esters are mostly found in the cuticles coating the primary shoot surfaces, but they also accumulate to high concentrations in the seed oils of a few plant species, including jojoba (Simmondsia chinensis), a desert shrub that is the major commercial source of these compounds. Here, we report the identification and characterization of WSD1, a member of the bifunctional wax ester synthase/diacylglycerol acyltransferase gene family, which plays a key role in wax ester synthesis in Arabidopsis (Arabidopsis thaliana) stems, as first evidenced by severely reduced wax ester levels of in the stem wax of wsd1 mutants. In vitro assays using protein extracts from Escherichia coli expressing WSD1 showed that this enzyme has a high level of wax synthase activity and approximately 10-fold lower level of diacylglycerol acyltransferase activity. Expression of the WSD1 gene in Saccharomyces cerevisiae resulted in the accumulation of wax esters, but not triacylglycerol, indicating that WSD1 predominantly functions as a wax synthase. Analyses of WSD1 expression revealed that this gene is transcribed in flowers, top parts of stems, and leaves. Fully functional yellow fluorescent protein-tagged WSD1 protein was localized to the endoplasmic reticulum, demonstrating that biosynthesis of wax esters, the final products of the alcohol-forming pathway, occurs in this subcellular compartment. PMID:18621978

The leaf volatile constituents of Isatis tinctoria by Solid-Phase Microextraction and Gas chromatography/Mass Spectrometry.

PubMed

Condurso, Cettina; Verzera, Antonella; Romeo, Vincenza; Ziino, Marisa; Trozzi, Alessandra; Ragusa, Salvatore

2006-08-01

The leaf volatile constituents of Isatis tinctoria L. (Brassicaceae) have been studied by Solid-Phase Microextraction and Gas chromatography/Mass Spectrometry (SPME/GC-MS). Seventy components were fully characterized by mass spectra, linear retention indices, and injection of standards; the average composition (ppm) as single components and classes of substances is reported. Aliphatic hydrocarbons, acids, alcohols, aldehydes and esters, aromatic aldehydes, esters and ethers, furans, isothiocyanates and thiocyanates, sulfurated compounds, nitriles, terpenes and sesquiterpenes were identified. Leaf volatiles in Isatis tinctoria L. were characterized by a high amount of isothiocyanates which accounted for about 40 % of the total volatile fraction. Isothiocyanates are important and characteristic flavour compounds in Brassica vegetables and the cancer chemo-protective attributes are recently responsible for their growing interest.

Converting lignin derived phenolic aldehydes into microbial lipid by Trichosporon cutaneum.

PubMed

Hu, Mingshan; Wang, Juan; Gao, Qiuqiang; Bao, Jie

2018-06-18

Lignin is one of the major components of lignocellulose biomass and chemically degrades into phenolic aldehydes including 4-hydroxybenzaldehyde, vanillin, and syringaldehyde. No lipid accumulation from the phenolic aldehydes by oleaginous microbes had been succeeded. Compared with vanillin and syringaldehyde, T. cutaneum ACCC 20271 have better tolerance to 4-hydroxybenzaldehyde. 4-Hydroxybenzaldehyde was found to be able as the substrate for lipid accumulation, while vanillin and syringaldehyde were only converted to less toxic phenolic alcohols and acids without observable lipid accumulation, perhaps due to the space shelling of methoxyl group(s) in the structures. A long term fed batch fermentation of 4-hydroxybenzaldehyde accumulated 0.85 g L -1 of lipid, equivalent to 0.039 g lipid per gram of 4-hydroxybenzaldehyde substrate, approximately 3.7 folds greater than the control without 4-hydroxybenzaldehyde addition. The fatty acid composition well met the need for biodiesel synthesis. The preliminary pathway from 4-hydroxybenzaldehyde to lipid was predicted. This study took the first experimental trial on utilizing phenolic aldehydes as the sole carbon sources for microbial lipid accumulation by T. cutaneum ACCC 20271. Copyright © 2018 Elsevier B.V. All rights reserved.

Aldehyde-alcohol reactions catalyzed under mild conditions by chromium(III) terephthalate metal organic framework (MIL-101) and phosphotungstic acid composites.

PubMed

Bromberg, Lev; Hatton, T Alan

2011-12-01

Porous materials based on chromium(III) terephthalate metal organic frameworks (MIL-101) and their composites with phosphotungstic acid (PTA) were studied as heterogeneous acid catalysts in aldehyde-alcohol reactions exemplified by acetaldehyde-phenol (A-P) condensation and dimethylacetal formation from benzaldehyde and methanol (B-M reaction). The MIL-101 was synthesized solvothermically in water, and the MIL101/PTA composite materials were obtained by either impregnation of the already prepared MIL-101 porous matrix with phosphotungstic acid solution or by solvothermic treatment of aqueous mixtures of Cr(NO(3))(3), and terephthalic and phosphotungstic acids. The MIL101/PTA materials appeared to be effective catalysts for both A-P and B-M reactions occurring at room temperature, with half-lives ranging from 0.5 h (A-P) to 1.5-2 h (B-M) and turnover numbers over 600 for A-P and over 2900 for the B-M reaction, respectively. A synergistic effect of the strong acidic moieties (PTA) addition to mildly acidic Brønsted and Lewis acid cites of the MIL-101 was observed with the MIL101/PTA composites. The ability of the PTA and MIL101/PTA materials to strongly absorb and condense acetaldehyde vapors was discovered, with the MIL101/PTA absorbing over 10-fold its dry weight of acetaldehyde condensate at room temperature. The acetaldehyde was converted rapidly to crotonaldehyde and higher-molecular-weight compounds while in contact with MIL-101 and MIL101/PTA materials. The stability of the MIL-101 and MIL101/PTA catalysts was assessed within four cycles of the 1-day alcohol-aldehyde reactions in terms of the overall catalyst recovery, PTA or Cr content, and reaction rate constants in each cycle. The loss of the catalyst over 4 cycles was approximately 10 wt % for all tested catalysts due to the incomplete recovery and minute dissolution of the components. The reaction rates in all cycles remained unchanged and the catalyst losses stopped after the third cycle. The developed

Aldehyde Oxidase 4 Plays a Critical Role in Delaying Silique Senescence by Catalyzing Aldehyde Detoxification1[OPEN

PubMed Central

Yarmolinsky, Dmitry; Soltabayeva, Aigerim; Samani, Talya

2017-01-01

The Arabidopsis (Arabidopsis thaliana) aldehyde oxidases are a multigene family of four oxidases (AAO1–AAO4) that oxidize a variety of aldehydes, among them abscisic aldehyde, which is oxidized to the phytohormone abscisic acid. Toxic aldehydes are generated in plants both under normal conditions and in response to stress. The detoxification of such aldehydes by oxidation is attributed to aldehyde dehydrogenases but never to aldehyde oxidases. The feasibility of the detoxification of aldehydes in siliques via oxidation by AAO4 was demonstrated, first, by its ability to efficiently oxidize an array of aromatic and aliphatic aldehydes, including the reactive carbonyl species (RCS) acrolein, hydroxyl-2-nonenal, and malondialdehyde. Next, exogenous application of several aldehydes to siliques in AAO4 knockout (KO) Arabidopsis plants induced severe tissue damage and enhanced malondialdehyde levels and senescence symptoms, but not in wild-type siliques. Furthermore, abiotic stresses such as dark and ultraviolet C irradiation caused an increase in endogenous RCS and higher expression levels of senescence marker genes, leading to premature senescence of KO siliques, whereas RCS and senescence marker levels in wild-type siliques were hardly affected. Finally, in naturally senesced KO siliques, higher endogenous RCS levels were associated with enhanced senescence molecular markers, chlorophyll degradation, and earlier seed shattering compared with the wild type. The aldehyde-dependent differential generation of superoxide and hydrogen peroxide by AAO4 and the induction of AAO4 expression by hydrogen peroxide shown here suggest a self-amplification mechanism for detoxifying additional reactive aldehydes produced during stress. Taken together, our results indicate that AAO4 plays a critical role in delaying senescence in siliques by catalyzing aldehyde detoxification. PMID:28188272

Aldehyde dehydrogenase polymorphism in North American, South American, and Mexican Indian populations.

PubMed Central

Goedde, H W; Agarwal, D P; Harada, S; Rothhammer, F; Whittaker, J O; Lisker, R

1986-01-01

While about 40% of the South American Indian populations (Atacameños, Mapuche, Shuara) were found to be deficient in aldehyde dehydrogenase isozyme I (ALDH2 or E2), preliminary investigations showed very low incidence of isozyme deficiency among North American natives (Sioux, Navajo) and Mexican Indians (mestizo). Possible implications of such trait differences on cross-cultural behavioral response to alcohol drinking are discussed. PMID:3953578

The thermodynamic parameters of sorption and enantioselectivity of the chiral smectic liquid crystal 2-methylbutyl ester of 4-(4-decyloxybenzylideneamino)-cinnamic acid

NASA Astrophysics Data System (ADS)

Onuchak, L. A.; Stepanova, R. F.; Akopova, O. B.; Glebova, O. V.; Chernova, O. M.

2008-06-01

The thermodynamic characteristics of sorption of n-alkanes, arenes, aldehydes, monoatomic alcohols, and optical isomers of camphene and butanediol-2,3 by a chiral smectic liquid crystal, 2-methylbutyl ester of 4-(4-decyloxybenzylideneamino)-cinnamic acid, from the gas phase were studied over the temperature range including the S*C and S*A mesophases and isotropic phase. The standard and excess thermodynamic functions of sorption were determined for 26 sorbates of the classes of substances specified. The S*C and S*A mesophases exhibited selectivity with respect to the separation of para and meta xylenes (α p/m = 1.06 1.07, 90 108°C) and pronounced enantioselectivity (αR/S = 1.05 1.09, 87 108°C). The helically twisted structure of the smectic liquid crystal was shown to play an important role in the mechanism of the chiral recognition of optical isomers of polar and low-polarity compounds under gas-liquid chromatography conditions.

Allyl Transfer to Aldehydes and Ketones by Brønsted Acid Activation of Allyl and Crotyl 1,3,2-Dioxazaborolidines

PubMed Central

Reilly, Maureen K.; Rychnovsky, Scott D.

2010-01-01

Alkyl dioxazaborolidines are air-stable and often crystalline organoboranes. A variety of Brønsted acids activate allyl dioxazaborolidines to generate reactive allyl-transfer reagents in situ. These reagents add to aldehydes and ketones to generate the corresponding alcohols in good yields under mild conditions. The E- and Z-crotyl reagents react diastereoselectively with aldehydes and ketones to produce anti and syn adducts, respectively, a result consistent with a cyclic transition state (Type I mechanism). PMID:20942379

Fatty acid ethyl esters (FAEEs) as markers for alcohol in meconium: method validation and implementation of a screening program for prenatal drug exposure.

PubMed

Hastedt, Martin; Krumbiegel, Franziska; Gapert, René; Tsokos, Michael; Hartwig, Sven

2013-09-01

Alcohol consumption during pregnancy is a widespread problem and can cause severe fetal damage. As the diagnosis of fetal alcohol syndrome is difficult, the implementation of a reliable marker for alcohol consumption during pregnancy into meconium drug screening programs would be invaluable. A previously published gas chromatography mass spectrometry method for the detection of fatty acid ethyl esters (FAEEs) as alcohol markers in meconium was optimized and newly validated for a sample size of 50 mg. This method was applied to 122 cases from a drug-using population. The meconium samples were also tested for common drugs of abuse. In 73 % of the cases, one or more drugs were found. Twenty percent of the samples tested positive for FAEEs at levels indicating significant alcohol exposure. Consequently, alcohol was found to be the third most frequently abused substance within the study group. This re-validated method provides an increase in testing sensitivity, is reliable and easily applicable as part of a drug screening program. It can be used as a non-invasive tool to detect high alcohol consumption in the last trimester of pregnancy. The introduction of FAEEs testing in meconium screening was found to be of particular use in a drug-using population.

Catalytic Amination of Alcohols, Aldehydes, and Ketones

NASA Astrophysics Data System (ADS)

Klyuev, M. V.; Khidekel', M. L.

1980-01-01

Data on the catalytic amination of alcohols and carbonyl compounds are examined, the catalysts for these processes are described, and the problems of their effectiveness, selectivity, and stability are discussed. The possible mechanisms of the reactions indicated are presented. The bibliography includes 266 references.

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

Stereocontrolled reduction of alpha- and beta-keto esters with micro green algae, Chlorella strains.

PubMed

Ishihara, K; Yamaguchi, H; Adachi, N; Hamada, H; Nakajima, N

2000-10-01

The stereocontrolled reduction of alpha- and beta-keto esters using micro green algae was accomplished by a combination of the cultivation method and the introduction of an additive. The reduction of ethyl pyruvate and ethyl benzoylformate by the photoautotrophically cultivated Chlorella sorokiniana gave the corresponding alcohol in high e.e. (>99% e.e. (S) and >99% e.e. (R), respectively). In the presence of glucose as an additive, the reduction of ethyl 3-methyl-2-oxobutanoate by the heterotrophically cultivated C. sorokiniana afforded the corresponding (R)-alcohol. On the other hand, the reduction in the presence of ethyl propionate gave the (S)-alcohol. Ethyl 2-methyl-3-oxobutanoate was reduced in the presence of glycerol by the photoautotrophically cultivated C. sorokiniana or the heterotrophically cultivated C. sorokiniana to the corresponding syn-(2R,3S)-hydroxy ester with high diastereo- and enantiomeric excess (e.e.). Some additives altered the stereochemical course in the reduction of alpha- and beta-keto esters.

Chemical and sensorial aroma characterization of freshly distilled Calvados. 1. Evaluation of quality and defects on the basis of key odorants by olfactometry and sensory analysis.

PubMed

Guichard, Hugues; Lemesle, Stéphane; Ledauphin, Jérôme; Barillier, Daniel; Picoche, Bernard

2003-01-15

Eight freshly distilled samples of Calvados, a fermented and distilled apple juice, were analyzed by sensory evaluation and direct injection GC to determine the composition of higher alcohols, esters, and aldehydes. The composition determined by direct injection was tentatively related to sensory descriptors. Esters have a probable maximum level around 500 g/hl of pure alcohol (PA). This level also corresponds to the threshold of the main ester constituent, ethyl acetate. A high ratio of esters to ethyl acetate seems to be of prime importance for good quality. Total aldehydes, with a maximum level between 8 and 11 g/hl of PA and mainly comprising acetal (maximum between 5 and 9 g/hl of PA), were related to a "green" descriptor. Higher alcohols do not have a direct impact on quality, but other volatile compounds with a positive impact on flavor should probably be present at a high level. As overall quality was not well related to sensory quality, it was necessary to perform more a precise analysis to determine the key odorants. The Calvados samples were thus extracted using pentane. Gas chromatography, employing both a flame ionization detector and an olfactometry port, was used to analyze the obtained extracts. Seventy-one odors were detected and distributed according to Calvados quality determined by sensory evaluation. Nineteen odors common to all Calvados samples constituted the "skeleton" of the aroma. Twenty-eight odors were specific to a quality class: 6 for good quality, 4 for neutral, and 18 for defective. Twenty-four other odors had either too low an odor impact or no evident specificity.

Simultaneous determination of trace concentrations of aldehydes and carboxylic acids in particulate matter.

PubMed

Rousová, Jana; Chintapalli, Manikyala R; Lindahl, Anastasia; Casey, Jana; Kubátová, Alena

2018-04-06

Carboxylic acids and aldehydes are present in ambient air particulate matter (PM) originating from both primary emission and secondary production in air and may, due to their polarity have, an impact on formation of cloud condensation nuclei. Their simultaneous determination may provide improved understanding of atmospheric processes. We developed a new analytical method allowing for a single step determination of majority of carboxylic acids and aldehydes (+95 compounds). This sample preparation employed O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine (PFBHA·HCl) in methanol to yield oximes (for aldehydes) and methyl esters (for majority of acids); with the limits of detection of 0.02-1 ng per injection, corresponding to approximately 0.4-20 μg/g PM . Subsequent trimethylsilylation with N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) was employed only for aromatic acids, which were not completely esterified, and for hydroxyl groups. Our method, in contrast to previous primarily qualitative studies, based on derivatization with an aqueous PFBHA followed by BSTFA derivatization, is less labor-intesive and reduces sample losses caused by an evaporation. The method was tested with a broad range of functionalized compounds (95), including monocarboxylic, dicarboxylic and aromatic acids, ketoacids, hydroxyacids and aldehydes. The developed protocol was applied to wood smoke (WS) and urban air standard reference material 1648b (UA) PM. The observed concentrations of aldehydes were 10-3000 μg/g PM in WS PM and 10-900 μg/g PM in UA PM, while those of acids were 20-1800 μg/g PM in WS PM and 15-1200 μg/g PM in UA PM. The most prominent aldehydes were syringaldehyde and vanillin in WS PM and glyoxal in UA PM. The most abundant acids in both PM samples were short-chain dicarboxylic acids (≤C 10 ). WS PM had a high abundance of hydroxyacids (vanillic and malic acids) as well as ketoacids (glutaric and oxalacetic) while UA PM also featured a high abundance of

Alcohol and aldehyde dehydrogenase polymorphisms and a new strategy for prevention and screening for cancer in the upper aerodigestive tract in East Asians.

PubMed

Yokoyama, Akira; Omori, Tai; Yokoyama, Tetsuji

2010-01-01

The ethanol in alcoholic beverages and the acetaldehyde associated with alcohol consumption are Group 1 human carcinogens (WHO, International Agency for Research on Cancer). The combination of alcohol consumption, tobacco smoking, the inactive heterozygous aldehyde dehydrogenase-2 genotype (ALDH2*1/*2) and the less-active homozygous alcohol dehydrogenase-1B genotype (ADH1B*1/*1) increases the risk of squamous cell carcinoma (SCC) in the upper aerodigestive tract (UADT) in a multiplicative fashion in East Asians. In addition to being exposed to locally high levels of ethanol, the UADT is exposed to a very high concentration of acetaldehyde from a variety of sources, including that as an ingredient of alcoholic beverages per se and that found in tobacco smoke; acetaldehyde is also produced by salivary microorganisms and mucosal enzymes and is present as blood acetaldehyde. The inefficient degradation of acetaldehyde by weakly expressed ALDH2 in the UADT may be cri! tical to the local accumulation of acetaldehyde, especially in ALDH2*1/*2 carriers. ADH1B*1/*1 carriers tend to experience less intense alcohol flushing and are highly susceptible to heavy drinking and alcoholism. Heavy drinking by persons with the less-active ADH1B*1/*1 leads to longer exposure of the UADT to salivary ethanol and acetaldehyde. The ALDH2*1/*2 genotype is a very strong predictor of synchronous and metachronous multiple SCCs in the UADT. High red cell mean corpuscular volume (MCV), esophageal dysplasia, and melanosis in the UADT, all of which are frequently found in ALDH2*1/*2 drinkers, are useful for identifying high-risk individuals. We invented a simple flushing questionnaire that enables prediction of the ALDH2 phenotype. New health appraisal models that include ALDH2 genotype, the simple flushing questionnaire, or MCV are powerful tools for devising a new strategy for prevention and screening for UADT cancer in East Asians.

Two-carbon homologation of aldehydes and ketones to a,ß-unsaturated aldehydes

USDA-ARS?s Scientific Manuscript database

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

A comparative study of aroma-active compounds between dark and milk chocolate: relationship to sensory perception.

PubMed

Liu, Jianbin; Liu, Mengya; He, Congcong; Song, Huanlu; Guo, Jia; Wang, Ye; Yang, Haiying; Su, Xiaoxia

2015-04-01

The most important aroma-active compounds of two types of chocolate and cocoa liquor used for their production were analysed by gas chromatography-olfactometry-mass spectrometry (GC-O-MS) and aroma extract dilution analysis (AEDA). Furthermore, the relationship between odorants and sensory perception of chocolate was measured by quantitative analysis, sensory evaluation and correlation analysis. In addition, some chemicals were added to the original dark or milk chocolate to validate their roles in the aroma property of chocolate. A total of 32 major aroma-active compounds were identified in the chocolate with the flavour dilution factors of 27-729 by AEDA, including seven aldehydes, six pyrazines, three pyrroles, four carboxylic acids, four lactones, two alcohols, two ketones, one ester, one pyrone, one furan and one sulfur-containing compound. Further quantitative analysis showed that dark chocolate had higher contents of pyrazine, pyrrole, carboxylic acids, alcohols and Strecker aldehydes, whereas the concentration of lactones, esters, long chain aldehydes and ketones were higher in the milk type. Differences in volatile composition and descriptive flavour attributes between the dark and milk chocolate were observed. The relationship between aroma-active compounds and sensory perception in the chocolate was verified. © 2014 Society of Chemical Industry.

Rhenium(VII) Catalysis of Prins Cyclization Reactions

PubMed Central

Tadpetch, Kwanruthai; Rychnovsky, Scott D.

2009-01-01

The rhenium(VII) complex O3ReOSiPh3 are particularly effective catalyst for Prins cyclizations using aromatic and α,β-unsaturated aldehydes. The reaction conditions are mild and the highly substituted 4-hydroxy tetrahydropyran products are formed stereoselectively. Rhenium(VII) complexes appear to spontaneously form esters with alcohols and to directly activate electron rich alcohols for solvolysis. Re2O7 and perrhenic acid were equally effective in catalyzing these cyclizations. PMID:18816133

Aroma characterization of tangerine hybrids by gas-chromatography-olfactometry and sensory evaluation

USDA-ARS?s Scientific Manuscript database

Although a total of 150 volatiles were detected by GC-MS, only 49 aroma active peaks were found in a consensus by the three panelists. Aldehydes were the most important group with odor activity, as well as monoterpenes, esters, alcohols and ketones. 1,8-Cineole, ·-myrcene, (E,E)-2,4-nonadienal, hexa...

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...

Asymmetric 1,2-perfluoroalkyl migration: easy access to enantioenriched α-hydroxy-α-perfluoroalkyl esters.

PubMed

Wang, Pan; Feng, Liang-Wen; Wang, Lijia; Li, Jun-Fang; Liao, Saihu; Tang, Yong

2015-04-15

This study has led to the development of a novel, highly efficient, 1,2-perfluoro-alkyl/-aryl migration process in reactions of hydrate of 1-perfluoro-alkyl/-aryl-1,2-diketones with alcohols, which are promoted by a Zn(II)/bisoxazoline and form α-perfluoro-alkyl/-aryl-substituted α-hydroxy esters. With (-)-8-phenylmenthol as the alcohol, the corresponding menthol esters are generated in high yields with excellent levels of diastereoselectivity. The mechanistic studies show that the benzilic ester-type rearrangement reaction takes place via an unusual 1,2-migration of electron-deficient trifluoromethyl group rather than the phenyl group. The overall process serves as a novel, efficient, and simple approach for the synthesis of highly enantioenriched, biologically relevant α-hydroxy-α-perfluoroalkyl carboxylic acid derivatives.

A comparative multidimensional LC-MS proteomic analysis reveals mechanisms for furan aldehyde detoxification in Thermoanaerobacter pseudethanolicus 39E

DOE Office of Scientific and Technical Information (OSTI.GOV)

Clarkson, Sonya M.; Hamilton-Brehm, Scott D.; Giannone, Richard J.

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

A comparative multidimensional LC-MS proteomic analysis reveals mechanisms for furan aldehyde detoxification in Thermoanaerobacter pseudethanolicus 39E

DOE PAGES

Clarkson, Sonya M.; Hamilton-Brehm, Scott D.; Giannone, Richard J.; ...

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

One-Pot Multicomponent Coupling Methods for the Synthesis of Diastereo- and Enantioenriched (Z)-Trisubstituted Allylic Alcohols

PubMed Central

Kerrigan, Michael H.; Jeon, Sang-Jin; Chen, Young K.; Salvi, Luca; Carroll, Patrick J.; Walsh, Patrick J.

2009-01-01

(Z)-Trisubstituted allylic alcohols are widespread structural motifs in natural products and biologically active compounds but are difficult to directly prepare. Introduced herein is a general one-pot multicomponent coupling method for the synthesis of (Z)-α,α,β-trisubstituted allylic alcohols. (Z)-Trisubstituted vinylzinc reagents are formed in situ by initial hydroboration of 1-bromo-1-alkynes. Addition of dialkylzinc reagents induces a 1,2-metallate rearrangement that is followed by a boron-to-zinc transmetallation. The resulting vinylzinc reagents add to a variety of prochiral aldehydes to produce racemic (Z)-trisubstituted allylic alcohols. When enantioenriched aldehyde substrates are employed (Z)-trisubstituted allylic alcohols are isolated with high dr (>20:1 in many cases). For example, vinylation of enantioenriched benzyl protected α- and β-hydroxy propanal derivatives furnished the expected anti-Felkin addition products via chelation control. Surprisingly, silyl protected α-hydroxy aldehydes also afford anti-Felkin addition products. A protocol for the catalytic asymmetric addition of (Z)-trisubstituted vinylzinc reagents to prochiral aldehydes with a (−)-MIB-based catalyst has also been developed. Several additives were investigated as inhibitors of the Lewis acidic alkylzinc halide byproducts, which promote the background reaction to form the racemate. α-Ethyl and α-cyclohexyl (Z)-trisubstituted allylic alcohols can now be synthesized with excellent levels of enantioselectivity in the presence of diamine inhibitors. PMID:19476375

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

Kinetics of enzymatic synthesis of liquid wax ester from oleic acid and oleyl alcohol.

PubMed

Radzi, Salina Mat; Mohamad, Rosfarizan; Basri, Mahiran; Salleh, Abu Bakar; Ariff, Arbakariya; Rahman, Mohammad Basyaruddin Abdul; Rahman, Raja Noor Zaliha Raja Abdul

2010-01-01

The kinetics of wax ester synthesis from oleic acid and oleyl alcohol using immobilized lipase from Candida antartica as catalyst was studied with different types of impeller (Rushton turbine and AL-hydrofoil) to create different mixing conditions in 2l stirred tank reactor. The effects of catalyst concentration, reaction temperature, and impeller tip speed on the synthesis were also evaluated. Rushton turbine impeller exhibited highest conversion rate at lower impeller tip speed as compared to AL-hydrofoil impeller. A second-order reversible kinetic model from single progress curve for the prediction of fractional conversion at given reaction time was proposed and the corresponding kinetic parameter values were calculated by non-linear regression method. The results from the simulation using the proposed model showed satisfactory agreement with the experimental data. Activation energy shows a value of 21.77 Kcal/mol. The thermodynamic parameters of the process, enthalpy and entropy, were 21.15 Kcal/mol and 52.07 cal/mol.K, respectively.

The allylation reactions of aromatic aldehydes and ketones with tin dichloride in water.

PubMed

Bian, Yan-Jiang; Xue, Wei-Li; Yu, Xu-Guang

2010-01-01

The allylation reactions of aromatic aldehydes and ketones were carried out in 31-86% yield using SnCl(2)-H(2)O system under ultrasound irradiation at r.t. for 5h. The reactions in the same system gave homoallyl alcohols in 21-84% yield with stirring at r.t. for 24h. Compared with traditional stirring methods, ultrasonic irradiation is more convenient and efficient.

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...

Establishing very long-chain fatty alcohol and wax ester biosynthesis in Saccharomyces cerevisiae.

PubMed

Wenning, Leonie; Yu, Tao; David, Florian; Nielsen, Jens; Siewers, Verena

2017-05-01

Wax esters (WEs) are neutral lipids and can be used for a broad range of commercial applications, including personal care products, lubricants, or coatings. They are synthesized by enzymatic reactions catalyzed by a fatty acyl reductase (FAR) and a wax ester synthase (WS). At present, commercially used WEs are mainly isolated from Simmondsia chinensis (jojoba), but the high extraction costs and limited harvest areas constrain their use. The use of FARs in combination with different WSs to achieve a synthesis of jojoba-like WEs in bacteria and yeast has been reported previously, but the products were restricted to C28-C36 WEs. These rather short WEs make up only a very small percentage of the total WEs in natural jojoba oil. The synthesis of longer chain WEs (up to C44) in Saccharomyces cerevisiae has so far only been achieved after substrate feeding. Here we identified new routes for producing very long-chain fatty alcohols (VLCFOHs) up to a chain length of C22 by heterologous expression of a FAR derived from Apis mellifera (AmFAR1) or Marinobacter aquaeolei VT8 (Maqu_2220) in S. cerevisiae and achieved maximum yields of 3.22 ± 0.36 mg/g cell dry weight (CDW) and 7.84 ± 3.09 mg/g CDW, respectively, after 48 h. Moreover, we enabled the synthesis of jojoba-like WEs up to a chain length of C42, catalyzed by a combination of Maqu_2220 together with the WS from S. chinensis (SciWS) and the S. cerevisiae elongase Elo2p, with a maximum yield of 12.24 ± 3.35 mg/g CDW after 48 h. Biotechnol. Bioeng. 2017;114: 1025-1035. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Bioactivation to an aldehyde metabolite--possible role in the onset of toxicity induced by the anti-HIV drug abacavir.

PubMed

Grilo, Nádia M; Charneira, Catarina; Pereira, Sofia A; Monteiro, Emília C; Marques, M Matilde; Antunes, Alexandra M M

2014-01-30

Aldehydes are highly reactive molecules, which can be generated during numerous physiological processes, including the biotransformation of drugs. Several non-P450 enzymes participate in their metabolism albeit alcohol dehydrogenase and aldehyde dehydrogenase are the ones most frequently involved in this process. Endogenous and exogenous aldehydes have been strongly implicated in multiple human pathologies. Their ability to react with biomacromolecules (e.g. proteins) yielding covalent adducts is suggested to be the common primary mechanism underlying the toxicity of these reactive species. Abacavir is one of the options for combined anti-HIV therapy. Although individual susceptibilities to adverse effects differ among patients, abacavir is associated with idiosyncratic hypersensitivity drug reactions and an increased risk of cardiac dysfunction. This review highlights the current knowledge on abacavir metabolism and discusses the potential role of bioactivation to an aldehyde metabolite, capable of forming protein adducts, in the onset of abacavir-induced toxic outcomes. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

A Green Approach for Allylations of Aldehydes and Ketones: Combining Allylborate, Mechanochemistry and Lanthanide Catalyst.

PubMed

de Souza, Viviane P; Oliveira, Cristiane K; de Souza, Thiago M; Menezes, Paulo H; Alves, Severino; Longo, Ricardo L; Malvestiti, Ivani

2016-11-16

Secondary and tertiary alcohols synthesized via allylation of aldehydes and ketones are important compounds in bioactive natural products and industry, including pharmaceuticals. Development of a mechanochemical method using potassium allyltrifluoroborate salt and water, to successfully perform the allylation of aromatic and aliphatic carbonyl compounds is reported for the first time. By controlling the grinding parameters, the methodology can be selective, namely, very efficient for aldehydes and ineffective for ketones, but by employing lanthanide catalysts, the reactions with ketones can become practically quantitative. The catalyzed reactions can also be performed under mild aqueous stirring conditions. Considering the allylation agent and its by-products, aqueous media, energy efficiency and use of catalyst, the methodology meets most of the green chemistry principles.

First general methods toward aldehyde enolphosphates.

PubMed

Barthes, Nicolas; Grison, Claude

2012-02-01

We herein report two innovative methods toward aldehyde enolphosphates and the first saccharidic aldehyde enolphosphates. Aldehyde enolphosphate function is worthwhile to be considered as a good phosphoenolpyruvate analogue. Copyright © 2011 Elsevier Inc. All rights reserved.

21 CFR 178.3780 - Polyhydric alcohol esters of long chain monobasic acids.

Code of Federal Regulations, 2013 CFR

2013-04-01

... chloride copolymer articles complying with § 177.1980 of this chapter that contact food of Types I, II, IV... 1,050 to 1,700. The esters are produced by the reaction of either ethylene glycol or glycerol with... chain alpha-olefins, the unreacted carboxylic acids in the formation of the glycerol esters being...

21 CFR 178.3780 - Polyhydric alcohol esters of long chain monobasic acids.

Code of Federal Regulations, 2010 CFR

2010-04-01

... chloride copolymer articles complying with § 177.1980 of this chapter that contact food of Types I, II, IV... 1,050 to 1,700. The esters are produced by the reaction of either ethylene glycol or glycerol with... chain alpha-olefins, the unreacted carboxylic acids in the formation of the glycerol esters being...

21 CFR 178.3780 - Polyhydric alcohol esters of long chain monobasic acids.

Code of Federal Regulations, 2012 CFR

2012-04-01

... chloride copolymer articles complying with § 177.1980 of this chapter that contact food of Types I, II, IV... 1,050 to 1,700. The esters are produced by the reaction of either ethylene glycol or glycerol with... chain alpha-olefins, the unreacted carboxylic acids in the formation of the glycerol esters being...

21 CFR 178.3780 - Polyhydric alcohol esters of long chain monobasic acids.

Code of Federal Regulations, 2011 CFR

2011-04-01

... chloride copolymer articles complying with § 177.1980 of this chapter that contact food of Types I, II, IV... 1,050 to 1,700. The esters are produced by the reaction of either ethylene glycol or glycerol with... chain alpha-olefins, the unreacted carboxylic acids in the formation of the glycerol esters being...

Aldehyde Detection in Electronic Cigarette Aerosols

PubMed Central

2017-01-01

Acetaldehyde, acrolein, and formaldehyde are the principal toxic aldehydes present in cigarette smoke and contribute to the risk of cardiovascular disease and noncancerous pulmonary disease. The rapid growth of the use of electronic cigarettes (e-cigarettes) has raised concerns over emissions of these harmful aldehydes. This work determines emissions of these aldehydes in both free and bound (aldehyde–hemiacetal) forms and other carbonyls from the use of e-cigarettes. A novel silicon microreactor with a coating phase of 4-(2-aminooxyethyl)-morpholin-4-ium chloride (AMAH) was used to trap carbonyl compounds in the aerosols of e-cigarettes via oximation reactions. AMAH–aldehyde adducts were measured using gas chromatography–mass spectrometry. 1H nuclear magnetic resonance spectroscopy was used to analyze hemiacetals in the aerosols. These aldehydes were detected in the aerosols of all e-cigarettes. Newer-generation e-cigarette devices generated more aldehydes than the first-generation e-cigarettes because of higher battery power output. Formaldehyde–hemiacetal was detected in the aerosols generated from some e-liquids using the newer e-cigarette devices at a battery power output of 11.7 W and above. The emission of these aldehydes from all e-cigarettes, especially higher levels of aldehydes from the newer-generation e-cigarette devices, indicates the risk of using e-cigarettes. PMID:28393137

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

Water-soluble metal working fluids additives derived from the esters of acid anhydrides with higher alcohols for aluminum alloy materials.

PubMed

Yamamoto, Syutaro; Tomoda, Hideyuki; Watanabe, Shoji

2007-01-01

Water-soluble metal working fluids are used for processing of aluminum alloy materials. This short article describes properties of new additives in water-soluble metal working fluids for aluminum alloy materials. Many half esters or diesters were prepared from the reactions of higher alcohols with acid anhydrides. Interestingly, diesters of PTMG (tetrahydrofuran oligomer, MW = 650 and 1000) and polybutylene oxide (MW = 650) with maleic anhydride and succinic anhydride showed both of an excellent anti-corrosion property for aluminum alloy and a good hard water tolerance. The industrial soluble type processing oils including these additives also showed anti-corrosion property and hard water tolerance.

Cross-linked polyvinyl alcohol and method of making same

NASA Technical Reports Server (NTRS)

Hsu, L. C.; Sheibley, D. W.; Philipp, W. H. (Inventor)

1981-01-01

A film-forming polyvinyl alcohol polymer is mixed with a polyaldehyde-polysaccharide cross-linking agent having at least two monosaccharide units and a plurality of aldehyde groups per molecule, perferably an average of at least one aldehyde group per monosaccharide units. The cross-linking agent, such as a polydialdehyde starch, is used in an amount of about 2.5 to 20% of the theoretical amount required to cross-link all of the available hydroxyl groups of the polyvinyl alcohol polymer. Reaction between the polymer and cross-linking agent is effected in aqueous acidic solution to produce the cross-linked polymer. The polymer product has low electrical resistivity and other properties rendering it suitable for making separators for alkaline batteries.

USING ACID-RESISTANT PHOTOSENSITIVE EMULSIONS TO OBTAIN LOCAL INHOMOGENEITIES WITH A HIGH RESOLVING POWER ON MONOCRYSTALS AND FILMS OF GERMANIUM AND SILICON (PRIMENENIE KISLOTOSTOYKHIKH SVETOCHUVSTVITELNYKH EMULSII DLYA POLUCHENIYA LOKALNYKH NEODNORODNOSTEI S VYSOKIM RAZRESHENIEM NA MONOKRISTALLAKH I PLENKAKH GERMANIYA I KREMNIYA),

DTIC Science & Technology

It was found that the esters of polystyrene and cinnamic acid , polyvinyl alcohol, and cinnamic acid have high dielectric characteristics that change...Photosensitive acid -resisting emulsions for use in photoengraving of semiconductor parts and semiconductor surfaces were synthesized and tested...organosilicon compounds, cinnamic aldehyde, emulsions based on azo and diazo compounds and polymeric polyesters--were tested. The photoengraving method

Fatty acid ethyl esters (FAEE); comparative accumulation in human and guinea pig hair as a biomarker for prenatal alcohol exposure.

PubMed

Kulaga, Vivian; Caprara, Daniela; Iqbal, Umar; Kapur, Bhushan; Klein, Julia; Reynolds, James; Brien, James; Koren, Gideon

2006-01-01

To compare the incorporation rate (ICR) of fatty acid ethyl esters (FAEE) in hair between guinea pigs and humans, and to assess the relationship between ethanol exposure and FAEE concentrations in hair. Published data from pregnant guinea pigs, including maximum blood ethanol concentration (BEC), dosage regimen, and total hair FAEE concentration, were compared with published data from alcoholic patients, where dose of ethanol consumed and total hair FAEE concentration were reported. Mean values of ethanol Vmax for pregnant guinea pigs and humans were obtained from published data (26.2 and 24 mg/dl/h, respectively). Total and individual FAEE ICRs, defined as the ratio of hair FAEE to the area under the BEC-time curve (total systemic ethanol exposure), were found to be on average an order of magnitude lower in the guinea pig than in the human. The profiles of ester incorporation also differed slightly between species, with ethyl stearate being highly incorporated in guinea pig hair and less so in human hair. The results may reflect in the human greater FAEE production, greater FAEE deposition in hair, slower FAEE catabolism, differential sebum production and composition, or a combination thereof. Also, ethyl oleate was found to correlate with total systemic ethanol exposure for both guinea pigs and humans, correlation coefficients equalling 0.67 (P < 0.05) and 0.49 (P < 0.05), respectively. No other ethyl esters, nor total FAEE, were found to correlate with systemic ethanol exposure. When extrapolating FAEE concentrations in hair from guinea pigs to humans, an order of magnitude difference should be considered, with humans incorporating more FAEE per unit of ethanol exposure. Also, the results suggest caution should be taken when interpreting values of single esters because of their differential incorporation among species. Lastly, our findings suggest ethyl oleate may be of keen interest in FAEE hair analysis, particularly across species.

Reaction and catalyst engineering to exploit kinetically controlled whole-cell multistep biocatalysis for terminal FAME oxyfunctionalization.

PubMed

Schrewe, Manfred; Julsing, Mattijs K; Lange, Kerstin; Czarnotta, Eik; Schmid, Andreas; Bühler, Bruno

2014-09-01

The oxyfunctionalization of unactivated C−H bonds can selectively and efficiently be catalyzed by oxygenase-containing whole-cell biocatalysts. Recombinant Escherichia coli W3110 containing the alkane monooxygenase AlkBGT and the outer membrane protein AlkL from Pseudomonas putida GPo1 have been shown to efficiently catalyze the terminal oxyfunctionalization of renewable fatty acid methyl esters yielding bifunctional products of interest for polymer synthesis. In this study, AlkBGTL-containing E. coli W3110 is shown to catalyze the multistep conversion of dodecanoic acid methyl ester (DAME) via terminal alcohol and aldehyde to the acid, exhibiting Michaelis-Menten-type kinetics for each reaction step. In two-liquid phase biotransformations, the product formation pattern was found to be controlled by DAME availability. Supplying DAME as bulk organic phase led to accumulation of the terminal alcohol as the predominant product. Limiting DAME availability via application of bis(2-ethylhexyl)phthalate (BEHP) as organic carrier solvent enabled almost exclusive acid accumulation. Furthermore, utilization of BEHP enhanced catalyst stability by reducing toxic effects of substrate and products. A further shift towards the overoxidized products was achieved by co-expression of the gene encoding the alcohol dehydrogenase AlkJ, which was shown to catalyze efficient and irreversible alcohol to aldehyde oxidation in vivo. With DAME as organic phase, the aldehyde accumulated as main product using resting cells containing AlkBGT, AlkL, as well as AlkJ. This study highlights the versatility of whole-cell biocatalysis for synthesis of industrially relevant bifunctional building blocks and demonstrates how integrated reaction and catalyst engineering can be implemented to control product formation patterns in biocatalytic multistep reactions. © 2014 Wiley Periodicals, Inc.

Characterization of Wax Esters by Electrospray Ionization Tandem Mass Spectrometry: Double Bond Effect and Unusual Product Ions

PubMed Central

Chen, Jianzhong; Green, Kari B; Nichols, Kelly K

2015-01-01

A series of different types of wax esters (represented by RCOOR′) were systematically studied by using electrospray ionization (ESI) collision-induced dissociation tandem mass spectrometry (MS/MS) along with pseudo MS3 (in-source dissociation combined with MS/MS) on a quadrupole time-of-flight (Q-TOF) mass spectrometer. The tandem mass spectra patterns resulting from dissociation of ammonium/proton adducts of these wax esters were influenced by the wax ester type and the collision energy applied. The product ions [RCOOH2]+, [RCO]+ and [RCO – H2O]+ that have been reported previously were detected; however, different primary product ions were demonstrated for the three wax ester types including: 1) [RCOOH2]+ for saturated wax esters, 2) [RCOOH2]+, [RCO]+ and [RCO – H2O]+ for unsaturated wax esters containing only one double bond in the fatty acid moiety or with one additional double bond in the fatty alcohol moiety, and 3) [RCOOH2]+ and [RCO]+ for unsaturated wax esters containing a double bond in the fatty alcohol moiety alone. Other fragments included [R′]+ and several series of product ions for all types of wax esters. Interestingly, unusual product ions were detected, such as neutral molecule (including water, methanol and ammonia) adducts of [RCOOH2]+ ions for all types of wax esters and [R′ – 2H]+ ions for unsaturated fatty acyl-containing wax esters. The patterns of tandem mass spectra for different types of wax esters will inform future identification and quantification approaches of wax esters in biological samples as supported by a preliminary study of quantification of isomeric wax esters in human meibomian gland secretions. PMID:26178197

Characterization of Wax Esters by Electrospray Ionization Tandem Mass Spectrometry: Double Bond Effect and Unusual Product Ions.

PubMed

Chen, Jianzhong; Green, Kari B; Nichols, Kelly K

2015-08-01

A series of different types of wax esters (represented by RCOOR') were systematically studied by using electrospray ionization (ESI) collision-induced dissociation tandem mass spectrometry (MS/MS) along with pseudo MS(3) (in-source dissociation combined with MS/MS) on a quadrupole time-of-flight (Q-TOF) mass spectrometer. The tandem mass spectra patterns resulting from dissociation of ammonium/proton adducts of these wax esters were influenced by the wax ester type and the collision energy applied. The product ions [RCOOH2](+), [RCO](+) and [RCO-H2O](+) that have been reported previously were detected; however, different primary product ions were demonstrated for the three wax ester types including: (1) [RCOOH2](+) for saturated wax esters, (2) [RCOOH2](+), [RCO](+) and [RCO-H2O](+) for unsaturated wax esters containing only one double bond in the fatty acid moiety or with one additional double bond in the fatty alcohol moiety, and (3) [RCOOH2](+) and [RCO](+) for unsaturated wax esters containing a double bond in the fatty alcohol moiety alone. Other fragments included [R'](+) and several series of product ions for all types of wax esters. Interestingly, unusual product ions were detected, such as neutral molecule (including water, methanol and ammonia) adducts of [RCOOH2](+) ions for all types of wax esters and [R'-2H](+) ions for unsaturated fatty acyl-containing wax esters. The patterns of tandem mass spectra for different types of wax esters will inform future identification and quantification approaches of wax esters in biological samples as supported by a preliminary study of quantification of isomeric wax esters in human meibomian gland secretions.

Metabolic engineering of Clostridium autoethanogenum for selective alcohol production.

PubMed

Liew, Fungmin; Henstra, Anne M; Kӧpke, Michael; Winzer, Klaus; Simpson, Sean D; Minton, Nigel P

2017-03-01

Gas fermentation using acetogenic bacteria such as Clostridium autoethanogenum offers an attractive route for production of fuel ethanol from industrial waste gases. Acetate reduction to acetaldehyde and further to ethanol via an aldehyde: ferredoxin oxidoreductase (AOR) and alcohol dehydrogenase has been postulated alongside the classic pathway of ethanol formation via a bi-functional aldehyde/alcohol dehydrogenase (AdhE). Here we demonstrate that AOR is critical to ethanol formation in acetogens and inactivation of AdhE led to consistently enhanced autotrophic ethanol production (up to 180%). Using ClosTron and allelic exchange mutagenesis, which was demonstrated for the first time in an acetogen, we generated single mutants as well as double mutants for both aor and adhE isoforms to confirm the role of each gene. The aor1+2 double knockout strain lost the ability to convert exogenous acetate, propionate and butyrate into the corresponding alcohols, further highlighting the role of these enzymes in catalyzing the thermodynamically unfavourable reduction of carboxylic acids into alcohols. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

General and highly α-regioselective zinc-mediated prenylation of aldehydes and ketones.

PubMed

Zhao, Li-Ming; Jin, Hai-Shan; Wan, Li-Jing; Zhang, Li-Ming

2011-03-18

A simple, efficient, and general α-prenylation approach for the synthesis of a variety of α-prenylated alcohols has been successfully developed. A wide range of α-prenylated alcohol derivatives could be obtained in good yields by highly α-regioselective zinc-mediated prenylation of various aldehydes and ketones with prenyl bromide at 120 °C in HMPA. By simply altering the reaciton solvent and temperature, the method allows the achievement of a highly notable opposite regiocontrol, providing the expected regiochemical product. The method provides a convenient route for the direct α-prenylation of carbonyl compounds in a highly α-regioselective manner using a cheap and convenient mediator. Two possible pathways are proposed to account for the formation of these synthetically difficult-to-obtain molecules.

Varietal Dependence of GLVs Accumulation and LOX-HPL Pathway Gene Expression in Four Vitis vinifera Wine Grapes

PubMed Central

Qian, Xu; Xu, Xiao-Qing; Yu, Ke-Ji; Zhu, Bao-Qing; Lan, Yi-Bin; Duan, Chang-Qing; Pan, Qiu-Hong

2016-01-01

Variety is one of the major factors influencing grape and wine aromatic characteristics. Green leaf volatiles (GLVs), derived from lipoxygenase-hydroperoxides lyase (LOX-HPL) pathway, are important components for the aromatic quality of grapes and wines. However, the varietal difference regarding GLVs accumulation and related gene expression are poorly studied. This work exhibited that the accumulation of various GLVs and the expression of LOX-HPL pathway genes in four Vitis vinifera wine grape cultivars: Syrah, Muscat Tchervine, Gewürztraminer and Chardonnay. The results showed a variety dependence of GLVs profile. Muscat Tchervine harvested grapes contained less C6 aldehydes and the most abundant esters, which corresponded to very low VvLOXA and VvHPL1 expression abundance as well as high VvAAT transcript in this variety. High expression level of both VvLOXA and VvHPL1 paralleled with higher level of C6 aldehydes together with higher alcohols in Syrah grape. Gewürztraminer and Chardonnay grapes had high aldehydes and alcohols as well as low esters, which were resulted from their higher expression level of VvLOXA or VvHPL1 and lower VvAAT. From these above corresponding relations, it is concluded that VvLOXA, VvHPL1 and VvAAT in the LOX-HPL pathway are targets for altering GLVs composition in the grape varieties. PMID:27886056

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

A direct conversion of benzylic and allylic alcohols to phosphonates

PubMed Central

Barney, Rocky J.; Richardson, Rebekah M.; Wiemer, David F.

2011-01-01

Benzyl phosphonate esters often serve as reagents in Horner-Wadsworth-Emmons reactions. In most cases, they can be prepared from benzylic alcohols via formation of the corresponding halide followed by an Arbuzov reaction. To identify a more direct synthesis of phosphonate esters, we have developed a one-flask procedure for conversion of benzylic and allylic alcohols to the corresponding phosphonates through treatment with triethyl phosphite and ZnI2. PMID:21405073

Aldehyde-forming fatty acyl-CoA reductase from cyanobacteria: expression, purification and characterization of the recombinant enzyme.

PubMed

Lin, Fengming; Das, Debasis; Lin, Xiaoxia N; Marsh, E Neil G

2013-10-01

Long-chain acyl-CoA reductases (ACRs) catalyze a key step in the biosynthesis of hydrocarbon waxes. As such they are attractive as components in engineered metabolic pathways for 'drop in' biofuels. Most ACR enzymes are integral membrane proteins, but a cytosolic ACR was recently discovered in cyanobacteria. The ACR from Synechococcus elongatus was overexpressed in Escherichia coli, purified and characterized. The enzyme was specific for NADPH and catalyzed the reduction of fatty acyl-CoA esters to the corresponding aldehydes, rather than alcohols. Stearoyl-CoA was the most effective substrate, being reduced more rapidly than either longer or shorter chain acyl-CoAs. ACR required divalent metal ions, e.g. Mg(2+), for activity and was stimulated ~ 10-fold by K(+). The enzyme was inactivated by iodoacetamide and was acylated on incubation with stearoyl-CoA, suggesting that reduction occurs through an enzyme-thioester intermediate. Consistent with this, steady state kinetic analysis indicates that the enzyme operates by a 'ping-pong' mechanism with kcat = 0.36 ± 0.023 min(-1), K(m)(stearoyl-CoA) = 31.9 ± 4.2 μM and K(m)(NADPH) = 35.6 ± 4.9 μM. The slow turnover number measured for ACR poses a challenge for its use in biofuel applications where highly efficient enzymes are needed. © 2013 FEBS.

Methods of refining and producing isomerized fatty acid esters and fatty acids from natural oil feedstocks

DOEpatents

Snead, Thomas E.; Cohen, Steven A.; Gildon, Demond L.; Beltran, Leslie V.; Kunz, Linda A.; Pals, Tessa M.; Quinn, Jordan R; Behrends, Jr., Raymond T.; Bernhardt, Randal J.

2016-07-05

Methods are provided for refining natural oil feedstocks and producing isomerized esters and acids. The methods comprise providing a C4-C18 unsaturated fatty ester or acid, and isomerizing the fatty acid ester or acid in the presence of heat or an isomerization catalyst to form an isomerized fatty ester or acid. In some embodiments, the methods comprise forming a dibasic ester or dibasic acid prior to the isomerizing step. In certain embodiments, the methods further comprise hydrolyzing the dibasic ester to form a dibasic acid. In certain embodiments, the olefin is formed by reacting the feedstock in the presence of a metathesis catalyst under conditions sufficient to form a metathesized product comprising olefins and esters, separating the olefins from the esters in the metathesized product, and transesterifying the esters in the presence of an alcohol to form a transesterified product having unsaturated esters.

Indium-catalyzed synthesis of keto esters from cyclic 1,3-diketones and alcohols and application to the synthesis of seratrodast.

PubMed

Kuninobu, Yoichiro; Kawata, Atsushi; Noborio, Taihei; Yamamoto, Syun-Ichi; Matsuki, Takashi; Takata, Kazumi; Takai, Kazuhiko

2010-04-01

Esterification reactions from cyclic 1,3-diketones and alcohols are carried out in the presence of several Lewis acids. In particular, indium(III) triflate, In(OTf)(3), iron(III) triflate, Fe(OTf)(3), copper(II) triflate, Cu(OTf)(2), and silver(I) triflate, AgOTf, show high catalytic activities. These reactions proceed through the carbon-carbon bond cleavage by a retro-aldol reaction and were found to be highly regioselective even in the presence of other functional groups. This type of reaction can also be applied to the preparation of the keto esters during the synthesis of seratrodast, which is an antiasthmatic and eicosanoid antagonist.

Direct catalytic asymmetric alpha-amination of aldehydes.

PubMed

List, Benjamin

2002-05-22

The first direct catalytic asymmetric alpha-amination of aldehydes is described herein. alpha-Unbranched aldehydes react in this novel proline-catalyzed reaction with dialkyl azodicarboxylates to give alpha-amino aldehydes in excellent yields and enantioselectivities.

Screening of adjunct cultures and their application in ester formation in Camembert-type cheese.

PubMed

Hong, Q; Liu, X M; Hang, F; Zhao, J X; Zhang, H; Chen, W

2018-04-01

The ethanol content and esterase and alcohol acyltransferase activities are the limiting factors in the synthesis of ethyl esters in Camembert-type cheeses. This study aimed to investigate the effects of alcohol, esterase and alcohol acyltransferase activities on ethyl ester formation in Camembert-type cheeses. Five experimental cheeses were prepared with three adjunct cultures with different enzyme activities and two levels of ethanol content (400 or 800 μg/g). The cheeses were aged for 4 weeks and analysed weekly for basic physicochemical, textural, volatile and sensory properties. The results showed that both the enzyme activity and ethanol content were limiting factors in the synthesis of ethyl esters in the Camembert-type cheeses. Variation in the esterase synthesis activity was observed among lactic acid bacteria, and the starter culture Lactococcus lactis MA 14 LYO distinguished itself through its high acidifying and esterase hydrolysis abilities. The addition of CCFM 12, a lactic acid bacteria strain with high esterase and alcohol acyltransferase activity, along with 400 or 800 μg/g of ethanol, notably enhanced the generation of ethyl esters and the corresponding fruity flavour, without causing dramatic changes in the basic physicochemical indices and microbial profile. In addition, cohesiveness was influenced by the addition of 400 and 800 μg/g of ethanol, and more resilience with 800 μg/g of ethanol had been found. The results showed that the addition of CCFM12 with 400 and 800 μg/g of ethanol may be applied in the production of Camembert cheese to enhance its fruity flavour. Copyright © 2017 Elsevier Ltd. All rights reserved.

Methods of making alkyl esters

DOEpatents

Elliott, Brian

2010-08-03

A method comprising contacting an alcohol, a feed comprising one or more glycerides and equal to or greater than 2 wt % of one or more free fatty acids, and a solid acid catalyst, a nanostructured polymer catalyst, or a sulfated zirconia catalyst in one or more reactors, and recovering from the one or more reactors an effluent comprising equal to or greater than about 75 wt % alkyl ester and equal to or less than about 5 wt % glyceride.

Chemoenzymatic Synthesis and Chemical Recycling of Poly(ester-urethane)s

PubMed Central

Hayashi, Hiroto; Yanagishita, Yoshio; Matsumura, Shuichi

2011-01-01

Novel poly(ester-urethane)s were prepared by a synthetic route using a lipase that avoids the use of hazardous diisocyanate. The urethane linkage was formed by the reaction of phenyl carbonate with amino acids and amino alcohols that produced urethane-containing diacids and hydroxy acids, respectively. The urethane diacid underwent polymerization with polyethylene glycol and α,ω-alkanediols and also the urethane-containing hydroxy acid monomer was polymerized by the lipase to produce high-molecular-weight poly(ester-urethane)s. The periodic introduction of ester linkages into the polyurethane chain by the lipase-catalyzed polymerization afforded chemically recyclable points. They were readily depolymerized in the presence of lipase into cyclic oligomers, which were readily repolymerized in the presence of the same enzyme. Due to the symmetrical structure of the polymers, poly(ester-urethane)s synthesized in this study showed higher Tm, Young’s modulus and tensile strength values. PMID:22016604

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. Copyright © 2015 Elsevier Inc. All rights reserved.

Recent advances in biotechnological applications of alcohol dehydrogenases.

PubMed

Zheng, Yu-Guo; Yin, Huan-Huan; Yu, Dao-Fu; Chen, Xiang; Tang, Xiao-Ling; Zhang, Xiao-Jian; Xue, Ya-Ping; Wang, Ya-Jun; Liu, Zhi-Qiang

2017-02-01

Alcohol dehydrogenases (ADHs), which belong to the oxidoreductase superfamily, catalyze the interconversion between alcohols and aldehydes or ketones with high stereoselectivity under mild conditions. ADHs are widely employed as biocatalysts for the dynamic kinetic resolution of racemic substrates and for the preparation of enantiomerically pure chemicals. This review provides an overview of biotechnological applications for ADHs in the production of chiral pharmaceuticals and fine chemicals.

Myoglobin-Catalyzed Olefination of Aldehydes.

PubMed

Tyagi, Vikas; Fasan, Rudi

2016-02-12

The olefination of aldehydes constitutes a most valuable and widely adopted strategy for constructing carbon-carbon double bonds in organic chemistry. While various synthetic methods have been made available for this purpose, no biocatalysts are known to mediate this transformation. Reported herein is that engineered myoglobin variants can catalyze the olefination of aldehydes in the presence of α-diazoesters with high catalytic efficiency (up to 4,900 turnovers) and excellent E diastereoselectivity (92-99.9 % de). This transformation could be applied to the olefination of a variety of substituted benzaldehydes and heteroaromatic aldehydes, also in combination with different alkyl α-diazoacetate reagents. This work provides a first example of biocatalytic aldehyde olefination and extends the spectrum of synthetically valuable chemical transformations accessible using metalloprotein-based catalysts. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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. Copyright © 2015 John Wiley & Sons, Ltd.

Deodorants: an experimental provocation study with cinnamic aldehyde.

PubMed

Bruze, Magnus; Johansen, J D; Andersen, K E; Frosch, P; Lepoittevin, J-P; Rastogi, S; Wakelin, S; White, I; Menné, T

2003-02-01

Axillary dermatitis is common and overrepresented in individuals with contact allergy to fragrances. Many individuals suspect their deodorants to be the incriminating products. Our aim was to investigate the significance of cinnamic aldehyde in deodorants for the development of axillary dermatitis when used by individuals with and without contact allergy to cinnamic aldehyde. Patch tests with deodorants and ethanol solutions with cinnamic aldehyde, and repeated open application tests with roll-on deodorants without and with cinnamic aldehyde at different concentrations, were performed in 37 patients with dermatitis, 20 without and 17 with contact allergy to cinnamic aldehyde. A repeated open application test with positive findings was noted only in patients hypersensitive to cinnamic aldehyde (P <.001) and only in the axilla to which the deodorants containing cinnamic aldehyde had been applied (P <.001). Deodorants containing cinnamic aldehyde in the concentration range 0.01% to 0.32%, used twice daily on healthy skin, can elicit axillary dermatitis within a few weeks.

Mode of oxygen and carbon dioxide action on strawberry ester biosynthesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ke, D.; Zhou, L.; Kader, A.A.

1994-09-01

Chandler strawberries (Fragaria ananassa Duck.) were kept in air, 0.25% O[sub 2], 21% O[sub 2] + 50% CO[sub 2], or 0.25 O[sub 2] + 50% CO[sub 2] (balance N[sub 2]) at 5 C for 1 to 7 days to study the effects of controlled atmospheres (CAs) on volatiles and fermentation enzymes. Concentrations of acetaldehyde, ethanol, ethyl acetate, and ethyl butyrate were greatly increased, while concentrations of isopropyl acetate, propyl acetate, and butyl acetate were reduced by the three CA treatments compared to those of air-control fruit. The CA treatments enhanced activities of pyruvate decarboxylase (PDC) and alcohol dehydrogenase (ADH) butmore » slightly decreased activity of alcohol acetyltransferase (AAT). The results indicate that the enhanced PDC and ADH activities by CA treatments cause ethanol accumulation, which in turn drives the biosynthesis of ethyl esters. The increased ethanol concentration also competes with other alcohols for carboxyl groups for esterification reactions. The reduced AAT activity and limited availability of carboxyl groups due to ethanol competition decrease production of other acetate esters.« less

Effects of Moderate Alcohol Consumption on Gene Expression Related to Colonic Inflammation and Antioxidant Enzymes in Rats

PubMed Central

Klarich, DawnKylee S.; Penprase, Jerrold; Cintora, Patricia; Medrano, Octavio; Erwin, Danielle; Brasser, Susan M.; Hong, Mee Young

2017-01-01

Excessive alcohol consumption is a risk factor associated with colorectal cancer; however, some studies have reported that moderate alcohol consumption may not contribute additional risk for developing colorectal cancer while others suggest that moderate alcohol consumption provides a protective effect that reduces colorectal cancer risk. The purpose of this study was to determine the effects of moderate voluntary alcohol (20% ethanol) intake on alternate days for 3 months in outbred Wistar rats on risk factors associated with colorectal cancer development. Colonic gene expression of cyclooxygenase-2, RelA, 8-oxoguanine DNA glycosylase 1, superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glutathione-S-transferase M1, and aldehyde dehydrogenase 2 were determined. Blood alcohol content, liver function enzyme activities, and 8-oxo-deoxyguanosine DNA adducts were also assessed. Alcohol-treated rats were found to have significantly lower 8-oxo-deoxyguanosine levels in blood, a marker of DNA damage. Alanine aminotransferase and lactate dehydrogenase were both significantly lower in the alcohol group. Moderate alcohol significantly decreased cyclooxygenase-2 gene expression, an inflammatory marker associated with colorectal cancer risk. The alcohol group had significantly increased glutathione-S-transferase M1 expression, an antioxidant enzyme that helps detoxify carcinogens, such as acetaldehyde, and significantly increased aldehyde dehydrogenase 2 expression, which allows for greater acetaldehyde clearance. Increased expression of glutathione-S-transferase M1 and aldehyde dehydrogenase 2 likely contributed to reduce mucosal damage that is caused by acetaldehyde accumulation. These results indicate that moderate alcohol may reduce the risk for colorectal cancer development, which was evidenced by reduced inflammation activity and lower DNA damage after alcohol exposure. PMID:28599714

Method for the determination of natural ester-type gum bases used as food additives via direct analysis of their constituent wax esters using high-temperature GC/MS.

PubMed

Tada, Atsuko; Ishizuki, Kyoko; Yamazaki, Takeshi; Sugimoto, Naoki; Akiyama, Hiroshi

2014-07-01

Natural ester-type gum bases, which are used worldwide as food additives, mainly consist of wax esters composed of long-chain fatty acids and long-chain fatty alcohols. There are many varieties of ester-type gum bases, and thus a useful method for their discrimination is needed in order to establish official specifications and manage their quality control. Herein is reported a rapid and simple method for the analysis of different ester-type gum bases used as food additives by high-temperature gas chromatography/mass spectrometry (GC/MS). With this method, the constituent wax esters in ester-type gum bases can be detected without hydrolysis and derivatization. The method was applied to the determination of 10 types of gum bases, including beeswax, carnauba wax, lanolin, and jojoba wax, and it was demonstrated that the gum bases derived from identical origins have specific and characteristic total ion chromatogram (TIC) patterns and ester compositions. Food additive gum bases were thus distinguished from one another based on their TIC patterns and then more clearly discriminated using simultaneous monitoring of the fragment ions corresponding to the fatty acid moieties of the individual molecular species of the wax esters. This direct high-temperature GC/MS method was shown to be very useful for the rapid and simple discrimination of varieties of ester-type gum bases used as food additives.

Method for the determination of natural ester-type gum bases used as food additives via direct analysis of their constituent wax esters using high-temperature GC/MS

PubMed Central

Tada, Atsuko; Ishizuki, Kyoko; Yamazaki, Takeshi; Sugimoto, Naoki; Akiyama, Hiroshi

2014-01-01

Natural ester-type gum bases, which are used worldwide as food additives, mainly consist of wax esters composed of long-chain fatty acids and long-chain fatty alcohols. There are many varieties of ester-type gum bases, and thus a useful method for their discrimination is needed in order to establish official specifications and manage their quality control. Herein is reported a rapid and simple method for the analysis of different ester-type gum bases used as food additives by high-temperature gas chromatography/mass spectrometry (GC/MS). With this method, the constituent wax esters in ester-type gum bases can be detected without hydrolysis and derivatization. The method was applied to the determination of 10 types of gum bases, including beeswax, carnauba wax, lanolin, and jojoba wax, and it was demonstrated that the gum bases derived from identical origins have specific and characteristic total ion chromatogram (TIC) patterns and ester compositions. Food additive gum bases were thus distinguished from one another based on their TIC patterns and then more clearly discriminated using simultaneous monitoring of the fragment ions corresponding to the fatty acid moieties of the individual molecular species of the wax esters. This direct high-temperature GC/MS method was shown to be very useful for the rapid and simple discrimination of varieties of ester-type gum bases used as food additives. PMID:25473499

Genetic polymorphisms of alcohol dehydrogenase-1B and aldehyde dehydrogenase-2 and liver cirrhosis, chronic calcific pancreatitis, diabetes mellitus, and hypertension among Japanese alcoholic men.

PubMed

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

2013-08-01

The presence of the less-active form of alcohol dehydrogenase-1B encoded by ADH1B*1/*1 (vs. *2 allele) and active form of aldehyde dehydrogenase-2 (ALDH2) encoded by ALDH2*1/*1 (vs. *2 allele) increases the risk of alcoholism in East Asians. The subjects in this cross-sectional survey were 1,902 Japanese alcoholic men (≥40 years) who underwent ADH1B/ALDH2 genotyping. Age-adjusted daily alcohol consumption did not differ according to the ADH1B/ALDH2 genotypes. The age-adjusted odds ratios (AORs; 95% confidence interval) for liver cirrhosis (LC; n = 359, 1.58 [1.19 to 2.09]), chronic calcific pancreatitis (CP; n = 80, 2.24 [1.20 to 4.20]), and diabetes mellitus (DM; n = 383, 1.51 [1.15 to 1.99]) were higher in the ADH1B*2 allele carriers than in the ADH1B*1/*1 carriers. The AORs for LC (1.43 [1.01 to 2.02]), CP (1.68 [0.80 to 3.53]), DM (1.63 [1.15 to 2.30]), and hypertension (HT; n = 495, 1.52 [1.11 to 2.07]) were higher in the ALDH2*1/*1 carriers than in the ALDH2*1/*2 carriers. The ADH1B*2-associated AOR for LC was 2.08 (1.46 to 2.94) among those aged 40 to 59 years, but 0.89 (0.56 to 1.43) among those aged 60 years or over, and the interaction between ADH1B genotype and age on the LC risk was significant (p = 0.009). When the group with non-LC and no/mild fibrosis was used as controls, the ADH1B*2-associated AORs increased according to the severity of their liver disease: 1.67 (1.32 to 2.11) for the group with non-LC and serum type IV collagen values ≥200 ng/ml, 1.81 (1.24 to 2.63) for the group of Child-Pugh class A LC, and 3.17 (1.98 to 5.07) for the group with Child-Pugh class B/C LC. Anti-hepatitis C virus (HCV) antibody was positive in 103 patients, and the groups with a high anti-HCV antibody titer and either the ADH1B*2/*2 genotype or the ALDH2*1/*1 genotype had the highest AORs (8.83 and 4.90, respectively). The population attributable fraction (PAF) due to the ADH1B*2 allele was 29% for LC, 47% for CP, and 27% for DM, and the PAF due to the ALDH2

The defensive secretion of Carabus lefebvrei Dejean 1826 pupa (Coleoptera, Carabidae): gland ultrastructure and chemical identification.

PubMed

Giglio, Anita; Brandmayr, Pietro; Dalpozzo, Renato; Sindona, Giovanni; Tagarelli, Antonio; Talarico, Federica; Brandmayr, Tullia Zetto; Ferrero, Enrico A

2009-05-01

This study documents the defensive function of flavored humor secreted by the abdominal glands of Carabus lefebvrei pupae. The morphology and the ultrastructure of these glands were described and the volatile compounds of glands secretion were identified by gas chromatography/mass spectrometry. The ultrastructure analysis shows an acinose complex formed by about 50 clusters. Each cluster has 20 glandular units and the unit-composed of one secretory and one canal cell lying along a duct-belongs to the class 3 cell type of Quennedey (1998). In the cytoplasm, the secretory cell contains abundant rough endoplasmatic reticula, glycogen granules, numerous mitochondria, and many well-developed Golgi complexes producing electron-dense secretory granules. Mitochondria are large, elongated, and often adjoining electronlucent vesicles. The kind and the origin of secretory granules varying in size and density were discussed. The chemical analysis of the gland secretion revealed the presence of a mixture of low molecular weight terpenes, ketones, aldehydes, alcohols, esters, and carboxylic acids. Monoterpenes, especially linalool, were the major products. We supposed that ketones, aldehydes, alcohols, esters, and carboxylic acids have a deterrent function against the predators and monoterpenes provide a prophylaxis function against pathogens. (c) 2008 Wiley-Liss, Inc.

Effect of pH on the interaction of volatile compounds with the myofibrillar proteins of duck meat.

PubMed

Yang, Q L; Lou, X W; Wang, Y; Pan, D D; Sun, Y Y; Cao, J X

2017-06-01

In order to clarify the influence of curing agents on the flavor of duck, the effect of pH on the surface hydrophobicity, secondary structures, and adsorption capacity of myofibrillar proteins to alcohols, aldehydes, ketones, and esters was assessed using Raman spectroscopy, gas chromatography-mass spectrometer, and other methodologies. The hydrophobicity decreased as pH increased from 5.0 to 8.0; β-turn turned into α-helix and random coil as pH increased from 5.0 to 7.0, while α-helix and random coil turned into β-sheet and β-turn as pH increased from 7.0 to 8.0. With the increase of pH, the decreased adsorbing of alcohols could depend on hydrogen bonds. As pH increased from 5.0 to 8.0, the increase of aldehydes and esters was attributed to the unfolding of myofibrillar proteins and decreased hydrophobicity. The decreased adsorbing of ketones was due to the decreased hydrophobicity as pH increased from 5.0 to 8.0. The present work provided information about the correlation between structure and adsorption capacity of myofibrillar proteins to flavor compounds. © 2016 Poultry Science Association Inc.

Desorption behavior of sorbed flavor compounds from packaging films with ethanol solution.

PubMed

Hwang, Y H; Matsui, T; Hanada, T; Shimoda, M; Matsumoto, K; Osajima, Y

2000-09-01

Desorption behavior of sorbed flavor compounds such as ethyl esters, n-aldehydes, and n-alcohols from LDPE and PET films was investigated in 0 to 100% (v/v) ethanol solutions at 20 degrees C, 50 degrees C, and 60 degrees C. In both films, the desorption apparently increased with increasing ethanol concentration and treatment temperature, depending on the compatibility of the flavor compound with the solvent. Namely, the partition coefficient of ethyl esters, n-aldehydes, and n-alcohols in the LDPE film turned out to be approximately zero at >/=60%, >/=80%, and >/=40% (v/v) ethanol, respectively (for PET film, >/=80%, >/=80%, and >/=40% (v/v) ethanol concentrations were required for complete desorption, respectively). As for physical properties (heat of fusion, melting point, and tensile strength and elongation at break) of LDPE and PET films, there were no significant differences between intact film and the treated film with 60% (v/v) ethanol for 30 min at 60 degrees C. These results suggest that it is possible to apply a desorption solvent such as ethanol solution for desorption of sorbed flavor compounds from packaging films with no physical change in the film properties by this desorption treatment.

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 P-94-1810...

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 P-94-1810...

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 P-94-1810...

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 P-94-1810...

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 P-94-1810...

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

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

2015-01-01

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. 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. 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). 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-metabolizing ADH1B was associated with lower serum LDL

ALD5, PAD1, ATF1 and ATF2 facilitate the catabolism of coniferyl aldehyde, ferulic acid and p-coumaric acid in Saccharomyces cerevisiae

PubMed Central

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

2017-01-01

The ability of Saccharomyces cerevisiae to catabolize phenolic compounds remains to be fully elucidated. Conversion of coniferyl aldehyde, ferulic acid and p-coumaric acid by S. cerevisiae under aerobic conditions was previously reported. A conversion pathway was also proposed. In the present study, possible enzymes involved in the reported conversion were investigated. Aldehyde dehydrogenase Ald5, phenylacrylic acid decarboxylase Pad1, and alcohol acetyltransferases Atf1 and Atf2, were hypothesised to be involved. Corresponding genes for the four enzymes were overexpressed in a S. cerevisiae strain named APT_1. The ability of APT_1 to tolerate and convert the three phenolic compounds was tested. APT_1 was also compared to strains B_CALD heterologously expressing coniferyl aldehyde dehydrogenase from Pseudomonas, and an ald5Δ strain, all previously reported. APT_1 exhibited the fastest conversion of coniferyl aldehyde, ferulic acid and p-coumaric acid. Using the intermediates and conversion products of each compound, the catabolic route of coniferyl aldehyde, ferulic acid and p-coumaric acid in S. cerevisiae was studied in greater detail. PMID:28205618

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

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

Molecular Basis of Alcohol-Related Gastric and Colon Cancer.

PubMed

Na, Hye-Kyung; Lee, Ja Young

2017-05-24

Many meta-analysis, large cohort studies, and experimental studies suggest that chronic alcohol consumption increases the risk of gastric and colon cancer. Ethanol is metabolized by alcohol dehydrogenases (ADH), catalase or cytochrome P450 2E1 (CYP2E1) to acetaldehyde, which is then further oxidized to acetate by aldehyde dehydrogenase (ALDH). Acetaldehyde has been classified by the International Agency for Research on Cancer (IARC) as a Group 1 carcinogen to humans. The acetaldehyde level in the stomach and colon is locally influenced by gastric colonization by Helicobacter pylori or colonic microbes, as well as polymorphisms in the genes encoding tissue alcohol metabolizing enzymes, especially ALDH2. Alcohol stimulates the uptake of carcinogens and their metabolism and also changes the composition of enteric microbes in a way to enhance the aldehyde level. Alcohol also undergoes chemical coupling to membrane phospholipids and disrupts organization of tight junctions, leading to nuclear translocation of β-catenin and ZONAB, which may contributes to regulation of genes involved in proliferation, invasion and metastasis. Alcohol also generates reactive oxygen species (ROS) by suppressing the expression of antioxidant and cytoprotective enzymes and inducing expression of CYP2E1 which contribute to the metabolic activation of chemical carcinogens. Besides exerting genotoxic effects by directly damaging DNA, ROS can activates signaling molecules involved in inflammation, metastasis and angiogenesis. In addition, alcohol consumption induces folate deficiency, which may result in aberrant DNA methylation profiles, thereby influencing cancer-related gene expression.

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...

Evaluation of Beer Fermentation with a Novel Yeast
Williopsis saturnus.

PubMed

Liu, Shao-Quan; Quek, Althea Ying Hui

2016-12-01

The aim of this study is to evaluate the potential of a novel yeast Williopsis saturnus var. mrakii NCYC 500 to produce fruity beer. Fermentation performance of W. mrakii and beer volatile composition were compared against that fermented with Saccharomyces cerevisiae Safale US-05. o Brix, sugar and pH differed significantly between the two types of beer. A total of 8 alcohols, 11 acids, 41 esters, 9 aldehydes, 8 ketones, 21 terpenes and terpenoids, 5 Maillard reaction products and 2 volatile phenolic compounds were detected. Yeast strain Safale US-05 was more capable of producing a wider range of ethyl and other esters, while yeast strain NCYC 500 produced significantly higher amounts of acetate esters. Strain NCYC 500 retained more terpenes and terpenoids, suggesting that the resultant beer could possess more of the aromatic hint of hops. This study showed that W. saturnus var. mrakii NCYC 500 could ferment wort to produce low-alcohol beer with higher levels of acetate esters, terpenes and terpenoids than yeast S. cerevisiae Safale US-05.

Evaluation of Beer Fermentation with a Novel Yeast
Williopsis saturnus

PubMed Central

Quek, Althea Ying Hui

2016-01-01

Summary The aim of this study is to evaluate the potential of a novel yeast Williopsis saturnus var. mrakii NCYC 500 to produce fruity beer. Fermentation performance of W. mrakii and beer volatile composition were compared against that fermented with Saccharomyces cerevisiae Safale US-05. oBrix, sugar and pH differed significantly between the two types of beer. A total of 8 alcohols, 11 acids, 41 esters, 9 aldehydes, 8 ketones, 21 terpenes and terpenoids, 5 Maillard reaction products and 2 volatile phenolic compounds were detected. Yeast strain Safale US-05 was more capable of producing a wider range of ethyl and other esters, while yeast strain NCYC 500 produced significantly higher amounts of acetate esters. Strain NCYC 500 retained more terpenes and terpenoids, suggesting that the resultant beer could possess more of the aromatic hint of hops. This study showed that W. saturnus var. mrakii NCYC 500 could ferment wort to produce low-alcohol beer with higher levels of acetate esters, terpenes and terpenoids than yeast S. cerevisiae Safale US-05. PMID:28115897

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...

A Lysine at the C-Terminus of an Odorant-Binding Protein is Involved in Binding Aldehyde Pheromone Components in Two Helicoverpa Species

PubMed Central

Sun, Ya-Lan; Huang, Ling-Qiao; Pelosi, Paolo; Wang, Chen-Zhu

2013-01-01

Odorant-binding proteins (OBPs) are soluble proteins, whose role in olfaction of insects is being recognized as more and more important. We have cloned, expressed and purified an OBP (HarmOBP7) from the antennae of the moth Helicoverpa armigera. Western blot experiments indicate specific expression of this protein in the antennae of adults. HarmOBP7 binds both pheromone components Z-11-hexadecenal and Z-9-hexadecenal with good affinity. We have also performed a series of binding experiments with linear aldehydes, alcohols and esters, as well as with other compounds and found a requirement of medium size for best affinity. The affinity of OBP7, as well as that of a mutant lacking the last 6 residues does not substantially decrease in acidic conditions, but increases at basic pH values with no significant differences between wild-type and mutant. Binding to both pheromone components, instead, is negatively affected by the lack of the C-terminus. A second mutant, where one of the three lysine residues in the C-terminus (Lys123) was replaced by methionine showed reduced affinity to both pheromone components, as well as to their analogues, thus indicating that Lys123 is involved in binding these compounds, likely forming hydrogen bonds with the functional groups of the ligands. PMID:23372826

Association between alcoholism and the dopamine D4 receptor gene.

PubMed Central

Muramatsu, T; Higuchi, S; Murayama, M; Matsushita, S; Hayashida, M

1996-01-01

A point mutation in the aldehyde dehydrogenase 2 gene (ALDH2(2) allele) is considered to be a genetic deterrent for alcoholism; however, 80 of 655 Japanese alcoholics had the mutant allele. Genotype factors that might increase susceptibility by overriding the deterrent showed a higher frequency of a five repeat allele of the dopamine D4 receptor 48 bp repeat polymorphism in alcoholics with ALDH2(2) than in 100 other alcoholics and 144 controls. Alcoholics with the five repeat allele also abused other drugs more often. These data suggest the involvement of the dopamine system in the development of alcoholism and other addictive behaviour. PMID:8929946

RDH13L, an enzyme responsible for the aldehyde-alcohol redox coupling reaction (AL-OL coupling reaction) to supply 11-cis retinal in the carp cone retinoid cycle.

PubMed

Sato, Shinya; Miyazono, Sadaharu; Tachibanaki, Shuji; Kawamura, Satoru

2015-01-30

Cone photoreceptors require effective pigment regeneration mechanisms to maintain their sensitivity in the light. Our previous studies in carp cones suggested the presence of an unconventional and very effective mechanism to produce 11-cis retinal, the necessary component in pigment regeneration. In this reaction (aldehyde-alcohol redox coupling reaction, AL-OL coupling reaction), formation of 11-cis retinal, i.e. oxidation of 11-cis retinol is coupled to reduction of an aldehyde at a 1:1 molar ratio without exogenous NADP(H) which is usually required in this kind of reaction. Here, we identified carp retinol dehydrogenase 13-like (RDH13L) as an enzyme catalyzing the AL-OL coupling reaction. RDH13L was partially purified from purified carp cones, identified as a candidate protein, and its AL-OL coupling activity was confirmed using recombinant RDH13L. We further examined the substrate specificity, subcellular localization, and expression level of RDH13L. Based on these results, we concluded that RDH13L contributes to a significant part, but not all, of the AL-OL coupling activity in carp cones. RDH13L contained tightly bound NADP(+) which presumably functions as a cofactor in the reaction. Mouse RDH14, a mouse homolog of carp RDH13L, also showed the AL-OL coupling activity. Interestingly, although carp cone membranes, carp RDH13L and mouse RDH14 all showed the coupling activity at 15-37 °C, they also showed a conventional NADP(+)-dependent 11-cis retinol oxidation activity above 25 °C without addition of aldehydes. This dual mechanism of 11-cis retinal synthesis attained by carp RDH13L and mouse RDH14 probably contribute to effective pigment regeneration in cones that function in the light. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Production of wax esters via microbial oil synthesis from food industry waste and by-product streams.

PubMed

Papadaki, Aikaterini; Mallouchos, Athanasios; Efthymiou, Maria-Nefeli; Gardeli, Chryssavgi; Kopsahelis, Nikolaos; Aguieiras, Erika C G; Freire, Denise M G; Papanikolaou, Seraphim; Koutinas, Apostolis A

2017-12-01

The production of wax esters using microbial oils was demonstrated in this study. Microbial oils produced from food waste and by-product streams by three oleaginous yeasts were converted into wax esters via enzymatic catalysis. Palm oil was initially used to evaluate the influence of temperature and enzyme activity on wax ester synthesis catalysed by Novozyme 435 and Lipozyme lipases using cetyl, oleyl and behenyl alcohols. The highest conversion yields (up to 79.6%) were achieved using 4U/g of Novozyme 435 at 70°C. Transesterification of microbial oils to behenyl and cetyl esters was achieved at conversion yields up to 87.3% and 69.1%, respectively. Novozyme 435 was efficiently reused for six and three cycles during palm esters and microbial esters synthesis, respectively. The physicochemical properties of microbial oil derived behenyl esters were comparable to natural waxes. Wax esters from microbial oils have potential applications in cosmetics, chemical and food industries. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

Reversible catalytic dehydrogenation of alcohols for energy storage

DOE PAGES

Bonitatibus, Jr., Peter J.; Chakraborty, Sumit; Doherty, Mark D.; ...

2015-01-14

Reversibility of a dehydrogenation/hydrogenation catalytic reaction has been an elusive target for homogeneous catalysis. In this paper, 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. Finally, this reactivity suggests a strategy for the development of reversible fuel cell electrocatalysts for partial oxidation (dehydrogenation) of hydroxyl-containing fuels.

Genes contributing to the development of alcoholism: an overview.

PubMed

Edenberg, Howard J

2012-01-01

Genetic factors (i.e., variations in specific genes) account for a substantial portion of the risk for alcoholism. However, identifying those genes and the specific variations involved is challenging. Researchers have used both case-control and family studies to identify genes related to alcoholism risk. In addition, different strategies such as candidate gene analyses and genome-wide association studies have been used. The strongest effects have been found for specific variants of genes that encode two enzymes involved in alcohol metabolism-alcohol dehydrogenase and aldehyde dehydrogenase. Accumulating evidence indicates that variations in numerous other genes have smaller but measurable effects.

Alternative fuel properties of tall oil fatty acid methyl ester-diesel fuel blends.

PubMed

Altiparmak, Duran; Keskin, Ali; Koca, Atilla; Gürü, Metin

2007-01-01

In this experimental work, tall oil methyl ester-diesel fuel blends as alternative fuels for diesel engines were studied. Tall oil methyl ester was produced by reacting tall oil fatty acids with methyl alcohol under optimum conditions. The blends of tall oil methyl ester-diesel fuel were tested in a direct injection diesel engine at full load condition. The effects of the new fuel blends on the engine performance and exhaust emission were tested. It was observed that the engine torque and power output with tall oil methyl ester-diesel fuel blends increased up to 6.1% and 5.9%, respectively. It was also seen that CO emissions decreased to 38.9% and NO(x) emissions increased up to 30% with the new fuel blends. The smoke opacity did not vary significantly.

Chirped Pulse-Fourier Transform Microwave Spectroscopy of Ethyl 3-METHYL-3-PHENYLGLYCIDATE (strawberry Aldehyde)

NASA Astrophysics Data System (ADS)

Shipman, Steven T.; Neill, Justin L.; Muckle, Matt T.; Suenram, Richard D.; Pate, Brooks H.

2009-06-01

Strawberry aldehyde (C_{12} O_3 H_{14}), a common artificial flavoring compound, has two non-interconvertible conformational families defined by the relative stereochemistry around its epoxide carbons. In one family, referred to as the trans because the two large substituents (a phenyl ring and an ethyl ester) are on opposite sides of the epoxide ring, these two substituents are unable to interact with each other. However, in the cis family, there is a long-range interaction that is difficult to accurately capture in electronic structure calculations. Three trans and two cis conformations have been assigned by broadband chirped pulse Fourier transform microwave spectroscopy, along with the C-13 isotopomers in natural abundance for one conformer from each of the families. The agreement of the rotational constants, relative dipole moments, and relative energies between theory and experiment is excellent, even at relatively crude levels of theory, for the trans family, but is quite poor for the cis conformers. In addition, due to the reactivity of strawberry aldehyde and the high temperature to which it must be heated to yield a suitable vapor pressure, several decomposition products have been assigned, and more, as of yet unassigned, are likely to be present. This project demonstrates some of the challenges in performing large-molecule rotational spectroscopy.

In situ self cross-linking of polyvinyl alcohol battery separators

NASA Technical Reports Server (NTRS)

Philipp, W. H.; Hsu, L. C.; Sheibley, D. W. (Inventor)

1979-01-01

A battery separator was produced from a polyvinyl alcohol sheet structure which was subjected to an in situ, self crosslinking process by selective oxidation of the 1,2 diol units present in the polyvinyl alcohol sheet structure. The 1,2 diol units were cleaved to form aldehyde end groups which subsequently crosslink through acetalization of the 1,3 diol units of the polyvinyl alcohol. Selective oxidation was achieved using a solution of a suitable oxidizing agent such as periodic acid or lead tetraacetate.

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...

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.

Acute and chronic ethanol exposure differentially alters alcohol dehydrogenase and aldehyde dehydrogenase activity in the zebrafish liver.

PubMed

Tran, Steven; Nowicki, Magda; Chatterjee, Diptendu; Gerlai, Robert

2015-01-02

Chronic ethanol exposure paradigms have been successfully used in the past to induce behavioral and central nervous system related changes in zebrafish. However, it is currently unknown whether chronic ethanol exposure alters ethanol metabolism in adult zebrafish. In the current study we examine the effect of acute ethanol exposure on adult zebrafish behavioral responses, as well as alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) activity in the liver. We then examine how two different chronic ethanol exposure paradigms (continuous and repeated ethanol exposure) alter behavioral responses and liver enzyme activity during a subsequent acute ethanol challenge. Acute ethanol exposure increased locomotor activity in a dose-dependent manner. ADH activity was shown to exhibit an inverted U-shaped curve and ALDH activity was decreased by ethanol exposure at all doses. During the acute ethanol challenge, animals that were continuously housed in ethanol exhibited a significantly reduced locomotor response and increased ADH activity, however, ALDH activity did not change. Zebrafish that were repeatedly exposed to ethanol demonstrated a small but significant attenuation of the locomotor response during the acute ethanol challenge but ADH and ALDH activity was similar to controls. Overall, we identified two different chronic ethanol exposure paradigms that differentially alter behavioral and physiological responses in zebrafish. We speculate that these two paradigms may allow dissociation of central nervous system-related and liver enzyme-dependent ethanol induced changes in zebrafish. Copyright © 2014 Elsevier Inc. All rights reserved.

Estimates of alcohol-related oesophageal cancer burden in Japan: systematic review and meta-analyses

PubMed Central

Shield, Kevin D; Higuchi, Susumu; Yoshimura, Atsushi; Larsen, Elisabeth; Rehm, Maximilien X; Rehm, Jürgen

2015-01-01

Abstract Objective To refine estimates of the burden of alcohol-related oesophageal cancer in Japan. Methods We searched PubMed for published reviews and original studies on alcohol intake, aldehyde dehydrogenase polymorphisms, and risk for oesophageal cancer in Japan, published before 2014. We conducted random-effects meta-analyses, including subgroup analyses by aldehyde dehydrogenase variants. We estimated deaths and loss of disability-adjusted life years (DALYs) from oesophageal cancer using exposure distributions for alcohol based on age, sex and relative risks per unit of exposure. Findings We identified 14 relevant studies. Three cohort studies and four case-control studies had dose–response data. Evidence from cohort studies showed that people who consumed the equivalent of 100 g/day of pure alcohol had an 11.71 fold, (95% confidence interval, CI: 2.67–51.32) risk of oesophageal cancer compared to those who never consumed alcohol. Evidence from case-control studies showed that the increase in risk was 33.11 fold (95% CI: 8.15–134.43) in the population at large. The difference by study design is explained by the 159 fold (95% CI: 27.2–938.2) risk among those with an inactive aldehyde dehydrogenase enzyme variant. Applying these dose–response estimates to the national profile of alcohol intake yielded 5279 oesophageal cancer deaths and 102 988 DALYs lost – almost double the estimates produced by the most recent global burden of disease exercise. Conclusion Use of global dose–response data results in an underestimate of the burden of disease from oesophageal cancer in Japan. Where possible, national burden of disease studies should use results from the population concerned. PMID:26229204

Sensitive Determination of Volatile Organic Compounds and Aldehydes in Tattoo Inks.

PubMed

Lim, Hyun-Hee; Shin, Ho-Sang

2017-02-01

As the popularity of body art including tattoo ink has increased, the safety associated with it has become an important interest. In this study, twenty volatile organic compounds (VOCs) and two aldehydes in tattoo inks were identified and quantified. Headspace and gas chromatography-mass spectrometry (HS GC-MS) for the VOCs and HS GC-MS based on derivatization with 2,2,2-trifluoroethylhydrazine (TFEH) for aldehydes was developed. Benzene, chloroform, toluene, ethylbenzene, m-xylene, p-xylene, o-xylene, propylbenzene, chlorobenzene, tert-butylbenzene, 1,3,5-trimethylbenzene, styrene, 1,2,4-trimethylbenzene, 2-chlorotoluene, 4-chlorotoluene, 1,3-dichlorobenzene, 1,4-dichlorobenzene, 1,2-dichlorobenzene, 1,2,4-trichlorobenzene and isopropyl alcohol were detected with the concentration range of 0.02-207,000 mg/kg in 16 different tattoo inks. Formaldehyde and acetaldehyde were detected with the concentration range of 0.4-308 mg/kg in the same samples. Our analytical results represent solvents used intentionally or non-intentionally in tattoo inks, and thus they may provide important information for national regulation. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Biogenic Aldehydes as Therapeutic Targets for Cardiovascular Disease

PubMed Central

Nelson, Margaret-Ann M; Baba, Shahid P; Andersonc, Ethan J

2017-01-01

Aldehydes are continuously formed in biological systems through enzyme-dependent and spontaneous oxidation of lipids, glucose, and primary amines. These highly reactive, biogenic electrophiles can become toxic via covalent modification of proteins, lipids and DNA. Thus, agents that scavenge aldehydes through conjugation have therapeutic value for a number of major cardiovascular diseases. Several commonly-prescribed drugs (e.g., hydralazine) have been shown to have potent aldehyde-conjugating properties which may contribute to their beneficial effects. Herein, we briefly describe the major sources and toxicities of biogenic aldehydes in cardiovascular system, and provide an overview of drugs that are known to have aldehyde-conjugating effects. Some compounds of phytochemical origin, and histidyl-dipeptides with emerging therapeutic value in this area are also discussed. PMID:28528297

Purifying contaminated water. [DOE patent application

DOEpatents

Daughton, C.G.

1981-10-27

Process is presented for removing biorefactory compounds from contaminated water (e.g., oil shale retort waste-water) by contacting same with fragmented raw oil shale. Biorefractory removal is enhanced by preactivating the oil shale with at least one member of the group of carboxylic acids, alcohols, aldehydes, ketones, ethers, amines, amides, sulfoxides, mixed ether-esters and nitriles. Further purification is obtained by stripping, followed by biodegradation and removal of the cells.

Purifying contaminated water

DOEpatents

Daughton, Christian G.

1983-01-01

Process for removing biorefractory compounds from contaminated water (e.g., oil shale retort waste-water) by contacting same with fragmented raw oil shale. Biorefractory removal is enhanced by preactivating the oil shale with at least one member of the group of carboxylic, acids, alcohols, aldehydes, ketones, ethers, amines, amides, sulfoxides, mixed ether-esters and nitriles. Further purification is obtained by stripping, followed by biodegradation and removal of the cells.

An Efficient, Eco-friendly and Sustainable One-Pot Synthesis of 3,4-Dihydropyrimidin-2(1H)-ones Directly from Alcohols Catalyzed by Heteropolyanion-Based Ionic Liquids.

PubMed

Fu, Renzhong; Yang, Yang; Ma, Xudong; Sun, Yu; Li, Jin; Gao, Hang; Hu, Huaxing; Zeng, Xiaojun; Yi, Jun

2017-09-11

Efficient, eco-friendly and sustainable access to 3,4-dihydropyrimidin-2(1 H )-ones directly from alcohols under microwave and solvent-free conditions has been reported. The practical protocol involves heteropolyanion-based catalyzed oxidation of alcohols to aldehydes with NaNO₃ as the oxidant followed by cyclocondensation with dicarbonyl compounds and urea or thiourea in a two-step, one-pot manner. Compatibility with different functional groups, good to excellent yields and reusable catalysts are the main highlights. The utilization of alcohols instead of aldehydes is a valid and green alternative to the classical Biginelli reaction.

Determination of esters in glycerol phase after transesterification of vegetable oil.

PubMed

Hájek, Martin; Skopal, Frantisek; Kwiecien, Jirí; Cernoch, Michal

2010-06-30

In biodiesel production, glycerol is formed as a side product and it is contained in the glycerol phase. This phase contains (besides glycerol): water, soaps, alcohol, traces of catalyst and glycerides and the remaining esters. In this paper, a new method for the determination of esters in the glycerol phase is introduced. The determination enables the minimization of the losses of biodiesel within the production process. It is based on the gradient RP-LC method (water and acetonitrile) with refractometric detection. The analysis is easy and the samples do not need any treatment (only dilution by water) and has a low detection limit. The results of this method were compared with the results of two other published methods: isocratic HPLC and GC. The disadvantage of these two methods is that they need extensive treatment of the sample, which takes many hours, and they are able to determine only the sum of esters. The new method is reliable, much faster and able to differentiate esters of almost each higher fatty acid (e.g. linoleic, linolenic, strearic alkyl ester) in the glycerol phase. Copyright 2010 Elsevier B.V. All rights reserved.

Electrogenerative oxidation of lower alcohols to useful products

DOEpatents

Meshbesher, Thomas M.

1987-01-01

In the disclosed electrogenerative process for converting alcohols such as ethanol to aldehydes such as acetaldehyde, the alcohol starting material is an aqueous solution containing more than the azeotropic amount of water. Good first-pass conversions (<40% and more typically <50%) are obtained at operating cell voltages in the range of about 80 to about 350 millivolts at ordinary temperatures and pressures by using very high flow rates of alcohol to the exposed anode surface (i.e. the "gas" side of an anode whose other surface is in contact with the electrolyte). High molar flow rates of vaporized aqueous alcohol also help to keep formation of undesired byproducts at a low level.

Influence of Grape Composition on Red Wine Ester Profile: Comparison between Cabernet Sauvignon and Shiraz Cultivars from Australian Warm Climate.

PubMed

Antalick, Guillaume; Šuklje, Katja; Blackman, John W; Meeks, Campbell; Deloire, Alain; Schmidtke, Leigh M

2015-05-13

The relationship between grape composition and subsequent red wine ester profile was examined. Cabernet Sauvignon and Shiraz, from the same Australian very warm climate vineyard, were harvested at two different stages of maturity and triplicate wines were vinified. Grape analyses focused on nitrogen and lipid composition by measuring 18 amino acids by HPLC-FLD, 3 polyunsaturated fatty acids, and 6 C6-compounds derived from lipid degradation by GC-MS. Twenty esters and four higher alcohols were analyzed in wines by HS-SPME-GC-MS. Concentrations of the ethyl esters of branched acids were significantly affected by grape maturity, but the variations were inconsistent between cultivars. Small relative variations were observed between wines for ethyl esters of fatty acids, whereas higher alcohol acetates displayed the most obvious differences with concentrations ranging from 1.5- to 26-fold higher in Shiraz than in Cabernet Sauvignon wines regardless of the grape maturity. Grape analyses revealed the variations of wine ester composition might be related to specific grape juice nitrogen composition and lipid metabolism. To the authors' knowledge the present study is the first to investigate varietal differences in the ester profiles of Shiraz and Cabernet Sauvignon wines made with grapes harvested at different maturity stages.

Biogenic Aldehydes as Therapeutic Targets for Cardiovascular Disease.

PubMed

Nelson, Margaret-Ann M; Baba, Shahid P; Anderson, Ethan J

2017-04-01

Aldehydes are continuously formed in biological systems through enzyme-dependent and spontaneous oxidation of lipids, glucose, and primary amines. These highly reactive, biogenic electrophiles can become toxic via covalent modification of proteins, lipids and DNA. Thus, agents that scavenge aldehydes through conjugation have therapeutic value for a number of major cardiovascular diseases. Several commonly-prescribed drugs (e.g., hydralazine) have been shown to have potent aldehyde-conjugating properties which may contribute to their beneficial effects. Herein, we briefly describe the major sources and toxicities of biogenic aldehydes in cardiovascular system, and provide an overview of drugs that are known to have aldehyde-conjugating effects. Some compounds of phytochemical origin, and histidyl-dipeptides with emerging therapeutic value in this area are also discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

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.

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.

Microsphere coated substrate containing reactive aldehyde groups

NASA Technical Reports Server (NTRS)

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

Biodiesel production from triolein and short chain alcohols through biocatalysis.

PubMed

Salis, Andrea; Pinna, Marcella; Monduzzi, Maura; Solinas, Vincenzo

2005-09-29

Oleic acid alkyl esters (biodiesel) were synthesised by biocatalysis in solvent-free conditions. Different commercial immobilised lipases, namely Candida antarctica B, Rizhomucor miehei, and Pseudomonas cepacia, were tested towards the reaction between triolein and butanol to produce butyl oleate. Pseudomonas cepacia lipase resulted to be the most active enzyme reaching 100% of conversion after 6h. Different operative conditions such as reaction temperature, water activity, and reagent stoichiometric ratio were investigated and optimised. These conditions were then used to investigate the effect of linear and branched short chain alcohols. Methanol and 2-butanol were the worst alcohols: the former, probably, due to its low miscibility with the oil and the latter because secondary alcohols usually are less reactive than primary alcohols. Conversely, linear and branched primary alcohols with short alkyl chains (C(2)--C(4)) showed high reaction rate and conversion. A mixture of linear and branched short chain alcohols that mimics the residual of ethanol distillation (fusel oil) was successfully used for oleic acid ester synthesis. These compounds are important in biodiesel mixtures since they improve low temperature properties.

Genetics of alcoholism.

PubMed

Edenberg, Howard J; Foroud, Tatiana

2014-01-01

Multiple lines of evidence strongly indicate that genetic factors contribute to the risk for alcohol use disorders (AUD). There is substantial heterogeneity in AUD, which complicates studies seeking to identify specific genetic factors. To identify these genetic effects, several different alcohol-related phenotypes have been analyzed, including diagnosis and quantitative measures related to AUDs. Study designs have used candidate gene analyses, genetic linkage studies, genomewide association studies (GWAS), and analyses of rare variants. Two genes that encode enzymes of alcohol metabolism have the strongest effect on AUD: aldehyde dehydrogenase 2 and alcohol dehydrogenase 1B each has strongly protective variants that reduce risk, with odds ratios approximately 0.2-0.4. A number of other genes important in AUD have been identified and replicated, including GABRA2 and alcohol dehydrogenases 1B and 4. GWAS have identified additional candidates. Rare variants are likely also to play a role; studies of these are just beginning. A multifaceted approach to gene identification, targeting both rare and common variations and assembling much larger datasets for meta-analyses, is critical for identifying the key genes and pathways important in AUD. © 2014 Elsevier B.V. All rights reserved.

Identification of Aroma Compounds of Lamiaceae Species in Turkey Using the Purge and Trap Technique.

PubMed

Sonmezdag, Ahmet Salih; Kelebek, Hasim; Selli, Serkan

2017-02-08

The present research was planned to characterize the aroma composition of important members of the Lamiaceae family such as Salvia officinalis , Lavandula angustifolia and Mentha asiatica . Aroma components of the S. officinalis , L. angustifolia and M. asiatica were extracted with the purge and trap technique with dichloromethane and analyzed with the gas chromatography-mass spectrometry (GC-MS) technique. A total of 23, 33 and 33 aroma compounds were detected in Salvia officinalis , Lavandula angustifolia and Mentha asiatica , respectively including, acids, alcohols, aldehydes, esters, hydrocarbons and terpenes. Terpene compounds were both qualitatively and quantitatively the major chemical group among the identified aroma compounds, followed by esters. The main terpene compounds were 1,8-cineole, sabinene and linalool in Salvia officinalis , Lavandula angustifolia and Mentha asiatica , respectively. Among esters, linalyl acetate was the only and most important ester compound which was detected in all samples.

Temperature-enhanced alumina HPLC method for the analysis of wax esters, sterol esters, and methyl esters.

PubMed

Moreau, Robert A; Kohout, Karen; Singh, Vijay

2002-12-01

Previous attempts at separating nonpolar lipid esters (including wax esters, sterol esters, and methyl esters) have achieved only limited success. Among the several normal-phase methods tested, a single recent report of a method employing an alumina column at 30 degrees C with a binary gradient system was the most promising. In the current study, modification of the alumina method by increasing the column temperature to 75 degrees C improved the separation of standards of wax esters and sterol esters. Elevated column temperature also enhanced the separation of FAME with differing degrees of unsaturation. Evidence was also presented to indicate that the method similarly separated phytosterol esters, based on their levels of unsaturation. With the increased interest in phytosterol- and phytostanol-ester enriched functional foods, this method should provide a technique to characterize and compare these products.

Process for the generation of .alpha., .beta.-unsaturated carboxylic acids and esters using niobium catalyst

DOEpatents

Gogate, Makarand Ratnakav; Spivey, James Jerome; Zoeller, Joseph Robert

1999-01-01

A process using a niobium catalyst includes the step of reacting an ester or carboxylic acid with oxygen and an alcohol in the presence a niobium catalyst to respectively produce an .alpha.,.beta.-unsaturated ester or carboxylic acid. Methanol may be used as the alcohol, and the ester or carboxylic acid may be passed over the niobium catalyst in a vapor stream containing oxygen and methanol. Alternatively, the process using a niobium catalyst may involve the step of reacting an ester and oxygen in the presence the niobium catalyst to produce an .alpha.,.beta.-unsaturated carboxylic acid. In this case the ester may be a methyl ester. In either case, niobium oxide may be used as the niobium catalyst with the niobium oxide being present on a support. The support may be an oxide selected from the group consisting of silicon oxide, aluminum oxide, titanium oxide and mixtures thereof. The catalyst may be formed by reacting niobium fluoride with the oxide serving as the support. The niobium catalyst may contain elemental niobium within the range of 1 wt % to 70 wt %, and more preferably within the range of 10 wt % to 30 wt %. The process may be operated at a temperature from 150 to 450.degree. C. and preferably from 250 to 350.degree. C. The process may be operated at a pressure from 0.1 to 15 atm. absolute and preferably from 0.5-5 atm. absolute. The flow rate of reactants may be from 10 to 10,000 L/kg.sub.(cat) /h, and preferably from 100 to 1,000 L/kg.sub.(cat) /h.

Purification and characterization of a novel recombinant highly enantioselective short-chain NAD(H)-dependent alcohol dehydrogenase from Thermus thermophilus.

PubMed

Pennacchio, Angela; Pucci, Biagio; Secundo, Francesco; La Cara, Francesco; Rossi, Mosè; Raia, Carlo A

2008-07-01

The gene encoding a novel alcohol dehydrogenase (ADH) that belongs to the short-chain dehydrogenase/reductase (SDR) superfamily was identified in the extremely thermophilic, halotolerant gram-negative eubacterium Thermus thermophilus HB27. The T. thermophilus ADH gene (adh(Tt)) was heterologously overexpressed in Escherichia coli, and the protein (ADH(Tt)) was purified to homogeneity and characterized. ADH(Tt) is a tetrameric enzyme consisting of identical 26,961-Da subunits composed of 256 amino acids. The enzyme has remarkable thermophilicity and thermal stability, displaying activity at temperatures up to approximately 73 degrees C and a 30-min half-inactivation temperature of approximately 90 degrees C, as well as good tolerance to common organic solvents. ADH(Tt) has a strict requirement for NAD(H) as the coenzyme, a preference for reduction of aromatic ketones and alpha-keto esters, and poor activity on aromatic alcohols and aldehydes. This thermophilic enzyme catalyzes the following reactions with Prelog specificity: the reduction of acetophenone, 2,2,2-trifluoroacetophenone, alpha-tetralone, and alpha-methyl and alpha-ethyl benzoylformates to (S)-(-)-1-phenylethanol (>99% enantiomeric excess [ee]), (R)-alpha-(trifluoromethyl)benzyl alcohol (93% ee), (S)-alpha-tetralol (>99% ee), methyl (R)-(-)-mandelate (92% ee), and ethyl (R)-(-)-mandelate (95% ee), respectively, by way of an efficient in situ NADH-recycling system involving 2-propanol and a second thermophilic ADH. This study further supports the critical role of the D37 residue in discriminating NAD(H) from NADP(H) in members of the SDR superfamily.

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

PubMed

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

2013-02-01

Fourteen new naphthoquinone aliphatic amides and seventeen naphthoquinone aliphatic esters were synthesized in nine to ten steps from 1-hydroxy-2-naphthoic acid with 9-25% overall yield for the amides, and 16-21% overall yield for the esters. The key step of the amide synthesis is a coupling reaction between amine and various aliphatic acids using 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMTMM) as a coupling agent while for the ester synthesis, DCC/DMAP or CDI was used as the coupling reagent between aliphatic acids and naphthoquinone alcohol. Both naphthoquinone amides and esters were evaluated for their anticancer activity against KB cells. It was found that naphthoquinone aliphatic amides showed stronger anticancer activity than those of the esters when the chains are longer than 7-carbon atoms. The optimum chain of amides is expected to be 16-carbon atoms. In addition, naphthoquinone aliphatic esters with α-methyl on the ester moiety possessed much stronger anticancer activity than the straight chains. Decatenation assay revealed that naphthoquinone amide with 16-carbon atoms chain at 15 μM and 20 μM can completely inhibit hTopoIIα activity while at 10 μM the enzyme activity was moderately inhibited. Molecular docking result also showed the same trend as the cytotoxicity and decatenation assay. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Analysis of fatty acid ethyl esters in hair as possible markers of chronically elevated alcohol consumption by headspace solid-phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS).

PubMed

Pragst, F; Auwaerter, V; Sporkert, F; Spiegel, K

2001-09-15

Fatty acid ethyl esters (FAEE) are products of the nonoxidative ethanol metabolism, which are known to be detectable in blood only about 24h after the last alcohol intake. After deposition in hair they should be suitable long-term markers of chronically elevated alcohol consumption. Therefore, a method for the analysis of ethyl myristate, ethyl palmitate, ethyl oleate and ethyl stearate from hair was developed based on the extraction of the hair sample by a dimethylsulphoxide (DMSO)/n-hexane mixture, separation and evaporation of the n-hexane phase and application of headspace solid-phase microextraction (HS-SPME) in combination with gas chromatography-mass spectrometry (GC-MS) to the extract. For use as internal standards, the corresponding D(5)-ethyl esters were prepared. The HS-SPME/GC-MS measurements were automatically performed using a multi-purpose sampler. The detection limits of the FAEE were between 0.01 and 0.04ng/mg and the reproducibility was between 3.5 and 16%. By application of the method to hair samples of 21 fatalities with known heavy alcohol abuse 0.045-2.4ng/mg ethyl myristate, 0.35-13.5ng/mg ethyl palmitate, 0.25-7.7ng/mg ethyl oleate and 0.05-3.85ng/mg ethyl stearate were measured. For social drinkers (30-60g ethanol per week), the concentrations were about one order of magnitude smaller. For 10 teetotalers negative results or traces of ethyl palmitate were found. It was shown by supplementary investigations in single cases that FAEE are also present in sebum, that there is no strong difference in their concentrations between pubic, chest and scalp hair, and that they are detectable in hair segments after a 2 months period of abstinence. From the results follows that the measurement of FAEE concentrations in hair is a useful way for a retrospective detection of alcohol abuse.

New insights into the formation mechanism of Ag, Au and AgAu nanoparticles in aqueous alkaline media: alkoxides from alcohols, aldehydes and ketones as universal reducing agents.

PubMed

Gomes, Janaina F; Garcia, Amanda C; Ferreira, Eduardo B; Pires, Cleiton; Oliveira, Vanessa L; Tremiliosi-Filho, Germano; Gasparotto, Luiz H S

2015-09-07

In this report we present new insights into the formation mechanism of Ag, Au and AgAu nanoparticles with alcohols, aldehydes and ketones in alkaline medium at room temperature. We selected methanol, ethanol, glycerol, formaldehyde, acetaldehyde and acetone to demonstrate their capability of reducing gold and silver ions under the above-mentioned conditions. We showed that the particles are also formed with potassium tert-butoxide in the absence of hydroxides. Our results strongly suggest that alkoxides, formed from any molecule containing a hydroxyl or a functional group capable of generating them in alkaline medium, are the actual and universal reducing agent of silver and gold ions, in opposition to the currently accepted mechanisms. The universality of the reaction mechanism proposed in this work may impact on the production of noble nanoparticles with simple chemicals normally found in standard laboratories.

Beyond benzoin condensation: trimerization of aldehydes via metal-free aerobic oxidative esterification of aldehydes with benzoin products in the presence of cyanide.

PubMed

Kim, Yoo-Jin; Kim, Na Yeun; Cheon, Cheol-Hong

2014-05-02

An unusual trimerization of aldehydes in the presence of cyanide via metal-free aerobic oxidative esterification under ambient conditions is described. Various aromatic aldehydes provided the corresponding oxidative esterification products in good to excellent yields. Mechanistic studies suggested that this reaction would proceed via a two-step sequence: cyanide-catalyzed benzoin condensation of aldehydes and subsequent aerobic oxidative esterification of aldehydes with the resultant benzoin products. The usefulness of this protocol was further demonstrated by converting the resulting trimeric products into other biologically important compounds.

Synthesis and antibacterial activity of aromatic and heteroaromatic amino alcohols.

PubMed

de Almeida, Camila G; Reis, Samira G; de Almeida, Angelina M; Diniz, Claudio G; da Silva, Vânia L; Le Hyaric, Mireille

2011-11-01

Two series of aromatic and heteroaromatic amino alcohols were synthesized from alcohols and aldehydes and evaluated for their antibacterial activities. All the octylated compounds displayed a better activity against the four bacteria tested when evaluated by the agar diffusion method and were selected for the evaluation of minimal inhibitory concentration. The best results were obtained for p-octyloxybenzyl derivatives against Staphylococcus epidermidis (minimal inhibitory concentrations = 32 μm). © 2011 John Wiley & Sons A/S.

RP-HPLC-fluorescence analysis of aliphatic aldehydes: application to aldehyde-generating enzymes HACL1 and SGPL1

PubMed Central

Mezzar, Serena; de Schryver, Evelyn; Van Veldhoven, Paul P.

2014-01-01

Long-chain aldehydes are commonly produced in various processes, such as peroxisomal α-oxidation of long-chain 3-methyl-branched and 2-hydroxy fatty acids and microsomal breakdown of phosphorylated sphingoid bases. The enzymes involved in the aldehyde-generating steps of these processes are 2-hydroxyacyl-CoA lyase (HACL1) and sphingosine-1-phosphate lyase (SGPL1), respectively. In the present work, nonradioactive assays for these enzymes were developed employing the Hantzsch reaction. Tridecanal (C13-al) and heptadecanal (C17-al) were selected as model compounds and cyclohexane-1,3-dione as 1,3-diketone, and the fluorescent derivatives were analyzed by reversed phase (RP)-HPLC. Assay mixture composition, as well as pH and heating, were optimized for C13-al and C17-al. Under optimized conditions, these aldehydes could be quantified in picomolar range and different long-chain aldehyde derivatives were well resolved with a linear gradient elution by RP-HPLC. Aldehydes generated by recombinant enzymes could easily be detected via this method. Moreover, the assay allowed to document activity or deficiency in tissue homogenates and fibroblast lysates without an extraction step. In conclusion, a simple, quick, and cheap assay for the study of HACL1 and SGPL1 activities was developed, without relying on expensive mass spectrometric detectors or radioactive substrates. PMID:24323699

Structural and Affinity Determinants in the Interaction between Alcohol Acyltransferase from F. x ananassa and Several Alcohol Substrates: A Computational Study

PubMed Central

Herrera, Raúl; Caballero, Julio; Alzate-Morales, Jans H.

2016-01-01

Aroma and flavor are important factors of fruit quality and consumer preference. The specific pattern of aroma is generated during ripening by the accumulation of volatiles compounds, which are mainly esters. Alcohol acyltransferase (AAT) (EC 2.3.1.84) catalyzes the esterification reaction of aliphatic and aromatic alcohols and acyl-CoA into esters in fruits and flowers. In Fragaria x ananassa, there are different volatiles compounds that are obtained from different alcohol precursors, where octanol and hexanol are the most abundant during fruit ripening. At present, there is not structural evidence about the mechanism used by the AAT to synthesize esters. Experimental data attribute the kinetic role of this enzyme to 2 amino acidic residues in a highly conserved motif (HXXXD) that is located in the middle of the protein. With the aim to understand the molecular and energetic aspects of volatiles compound production from F. x ananassa, we first studied the binding modes of a series of alcohols, and also different acyl-CoA substrates, in a molecular model of alcohol acyltransferase from Fragaria x ananassa (SAAT) using molecular docking. Afterwards, the dynamical behavior of both substrates, docked within the SAAT binding site, was studied using routine molecular dynamics (MD) simulations. In addition, in order to correlate the experimental and theoretical data obtained in our laboratories, binding free energy calculations were performed; which previous results suggested that octanol, followed by hexanol, presented the best affinity for SAAT. Finally, and concerning the SAAT molecular reaction mechanism, it is suggested from molecular dynamics simulations that the reaction mechanism may proceed through the formation of a ternary complex, in where the Histidine residue at the HXXXD motif deprotonates the alcohol substrates. Then, a nucleophilic attack occurs from alcohol charged oxygen atom to the carbon atom at carbonyl group of the acyl CoA. This mechanism is in

Cellular fatty acids and aldehydes of oral Eubacterium.

PubMed

Itoh, U; Sato, M; Tsuchiya, H; Namikawa, I

1995-02-01

The cellular fatty acids and aldehydes of oral Eubacterium species were determined by gas chromatography-mass spectrometry. E. brachy and E. lentum contained mainly branched-chain fatty acids, whereas the others contained straight-chain acids. E. brachy, E. lentum, E. yurii ssp. yurii, E. yurii spp. margaretiae, E. limosum, E. plauti and E. aerofaciens also contained aldehydes with even carbon numbers. In addition to species-specific components, the compositional ratios of fatty acids and aldehydes characterized each individual species. The 10 species tested were divided into 5 groups by the principal component analysis. Cellular fatty acids and aldehydes would be chemical markers for interspecies differentiation of oral Eubacterium.

The two-step electrochemical oxidation of alcohols using a novel recombinant PQQ alcohol dehydrogenase as a catalyst for a bioanode.

PubMed

Takeda, Kouta; Matsumura, Hirotoshi; Ishida, Takuya; Samejima, Masahiro; Igarashi, Kiyohiko; Nakamura, Nobuhumi; Ohno, Hiroyuki

2013-12-01

A bioanode has been developed based on the oxidation of ethanol by the recombinant pyrroloquinoline quinone (PQQ) dependent alcohol dehydrogenase from Pseudomonas putidaKT2440 heterologously expressed in Pichia pastoris. The apo form of the recombinant protein (PpADH) was purified and displayed catalytic activity for binding PQQ in the presence of Ca(2+). PpADH exhibited broad substrate specificity towards various alcohols and aldehydes. The Km values for the aldehydes of PpADH were increased compared to those for the alcohols, whereas the kcat values were unaltered. For instance, the Km values at T=298.15K (25 °C) for ethanol and acetaldehyde were 0.21 (± 0.02)mM and 5.8 (± 0.60)mM, respectively. The kcat values for ethanol and acetaldehyde were 24.8 (± 1.2) s(-1) and 31.1 (± 1.2) s(-1), respectively. The aminoferrocene was used as an electron transfer mediator between PpADH and the electrode during electrochemical experiments. The catalytic currents for the oxidation of alcohol and acetaldehyde by PpADH were also observed in this system. The electric charge for the oxidation of ethanol (Q = 2.09 × 10(-3) · C) was increased two-fold compared to that for the oxidation of acetaldehyde (Q = 0.95 × 10(-3) · C), as determined by chronoamperometric measurements. Thus, we have electrochemically demonstrated the two-step oxidation of ethanol to acetate using only PpADH. © 2013.

The mechanism and thermodynamics of transesterification of acetate-ester enolates in the gas phase

NASA Astrophysics Data System (ADS)

Haas, George W.; Giblin, Daryl E.; Gross, Michael L.

1998-01-01

In solution, base-catalyzed hydrolysis and transesterification of esters are initiated by hydroxide- or alkoxide-ion attack at the carbonyl carbon. At low pressures in the gas phase, however, transesterification proceeds by an attack of the enolate anion of an acetate ester on an alcohol. Fourier transform mass spectrometry (FTMS) indicates that the reaction is the second-order process: -CH2-CO2-R + R'-OH --> - CH2-CO2-R' + R-OH and there is little to no detectable production of either alkoxide anion. Labeling studies show that the product and reactant enolate anion esters undergo exchange of hydrogens located [alpha] to the carbonyl carbon with the deuterium of R'-OD. The extent of the H/D exchange increases with reaction time, pointing to a short-lived intermediate. The alcoholysis reaction rate constants increase with increasing acidity of the primary, straight-chained alkyl alcohols, whereas steric effects associated with branched alcohols cause the rate constants to decrease. Equilibrium constants, which were determined directly from measurements at equilibrium and which were calculated from the forward and reverse rate constants, are near unity and show internal consistency. In the absence of steric effects, the larger enolate is always the favored product at equilibrium. The intermediate for the transesterification reaction, which can be generated at a few tenths of a torr in a tandem mass spectrometer, is tetrahedral, but other adducts that are collisionally stabilized under these conditions are principally loosely bound complexes.

Synthesis of hydrocarbons by CO2 fluid conversion with hydrogen: Experimental modeling at 7.8 GPa and 1350°C

NASA Astrophysics Data System (ADS)

Sokol, A. G.; Tomilenko, A. A.; Bul'bak, T. A.; Sobolev, N. V.

2017-12-01

Synthesis of hydrocarbons by the interaction of a CO2 fluid with hydrogen mantle domains has been simulated in an experiment at 7.8 GPa and 1350°C. The synthesized fluid contains mainly aldehydes; lower amounts of ketones, alcohols, esters, and ethers; as well as noticeable amounts of isobutane and butane, alkenes, arenes, and polycyclic aromatic and heterocyclic hydrocarbons. The fluid is compositionally close to volatiles found in inclusions from mantle olivines and picroilmenites.

Near Infrared Spectroscopic Identification of Alkyl Aromatic Esters and Phenyl Ketones

NASA Astrophysics Data System (ADS)

Nelyubov, D. V.; Vazhenin, D. A.; Kudriavtsev, A. A.; Buzolina, A. Yu.

2018-03-01

Bands characterizing the content of carbon atoms in alkyl (7177-7205 cm-1) and phenyl structural fragments (9175-9192 cm-1) in organic molecules were revealed by studying the near infrared spectra of such compounds. The optical density at the maxima of these absorption bands was shown to depend strongly on the fraction of carbon atoms in the corresponding fragments. The developed models proved to be adequate for determining the fraction of carbon atoms in alkyl aromatic esters and phenyl ketones. The feasibility of modeling the molecular structure of alkyl aromatic esters using regression models was demonstrated for the product of the condensation of oleic acid and benzyl alcohol.

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

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 31 2011-07-01 2011-07-01 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 the...

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

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 32 2012-07-01 2012-07-01 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 the...

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

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 31 2014-07-01 2014-07-01 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 the...

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

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 32 2013-07-01 2013-07-01 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 the...

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 the...

Palladium-metalated porous organic polymers as recyclable catalysts for chemoselective decarbonylation of aldehydes.

PubMed

Li, Wen-Hao; Li, Cun-Yao; Li, Yan; Tang, Hai-Tao; Wang, Heng-Shan; Pan, Ying-Ming; Ding, Yun-Jie

2018-06-07

A novel palladium nanoparticle (NP)-metalated porous organic ligand (Pd NPs/POL-xantphos) has been prepared for the chemoselective decarbonylation of aldehydes. This heterogenous catalyst not only has excellent catalytic activity and chemoselectivity, but also holds high activity after 10 runs of reuse. The effective usage of this method is demonstrated through the synthesis of biofuels such as furfuryl alcohol (FFA) via the highly chemoselective decarbonylation of biomass-derived 5-hydroxy-methylfurfural (HMF) with a TON up to 1540. More importantly, 9-fluorenone could be obtained in one step through the decarbonylation of 2-bromobenzaldehyde by using this heterogeneous catalyst.

Betaine aldehyde dehydrogenase isozymes of spinach

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 inmore » salinized leaves. The phenotype of a natural variant of isozyme number1 suggests that the enzyme is a dimer.« less

Synthesis of palm oil fatty acid and trimethylolpropane based ester for biolubricant base stocks

NASA Astrophysics Data System (ADS)

Nor, Nurazira Mohd; Derawi, Darfizzi; Salimon, Jumat

2018-04-01

RBD palm oil become one of the interesting renewable resources in biolubricant application. However, palm oil cannot be used directly as lubricant due to some performance limitations such as thermal and oxidative stability. This drawback can be overcome by chemical modification through esterification with polyhydric alcohol such as trimethylolpropane (TMP). The synthesis of ester was carried out via esterification of palm oil fatty acid (POFA) with TMP in the presence of 2% sulphuric acid as catalyst at 150 °C for 5 hours. Gas Chromatography equipped with a Flame Ionization Detector (GC-FID) was used to determine the percentage composition of POTMP ester. The structure confirmation of POTMP ester was proven by Fourier Transformation Infra-Red (FTIR), proton and carbon Nuclear Magnetic Resonance (1H-NMR and 13C-NMR) spectroscopy analysis. The result showed that POTMP ester has successfully synthesized with 97.7% composition of triesters (TE), proved by GC chromatogram. Presence of ester group also evidenced by 1H NMR at 2.27-2.30 ppm and 13C NMR at 173.52-173.54 ppm. The percentage yield of POTMP ester produced was 82% and exist in liquid form at room temperature.

Cinnamic aldehyde: a survey of consumer patch-test sensitization.

PubMed

Danneman, P J; Booman, K A; Dorsky, J; Kohrman, K A; Rothenstein, A S; Sedlak, R I; Steltenkamp, R J; Thompson, G R

1983-12-01

The potential for cinnamic aldehyde, an important fragrance and flavour ingredient, to induce or to elicit delayed contact hypersensitivity reactions in man was evaluated by analysing patch-test data. Results of studies involving a total of 4117 patch tests on various consumer products and fragrance blends containing cinnamic aldehyde and on the material itself were collected from fragrance and formulator companies. The data indicate that cinnamic aldehyde contained in consumer products and fragrance blends at concentrations up to 6 X 10(-1)%, and patch-tested at concentrations up to 8 X 10(-3)%, has no detectable potential to induce hypersensitivity. Cinnamic aldehyde when tested alone induced a dose-related hypersensitivity response. According to published reports, cinnamic aldehyde elicited positive delayed hypersensitivity responses in dermatitic patients. However, results of the current survey show that when cinnamic aldehyde was tested alone or as part of a mixture in subjects in the general population, no pre-existing hypersensitivity reactions to the fragrance material were observed in any of the 4117 patch tests which constituted the survey. Cinnamic aldehyde at the concentrations contained in consumer products and fragrances, has a very low potential to induce hypersensitivity ('induced' reactions) or to elicit sensitization reactions ('elicited' reactions) in the general population.

Emissions from diesel engines using fatty acid methyl esters from different vegetable oils as blends and pure fuel

NASA Astrophysics Data System (ADS)

Schröder, O.; Munack, A.; Schaak, J.; Pabst, C.; Schmidt, L.; Bünger, J.; Krahl, J.

2012-05-01

Biodiesel is used as a neat fuel as well as in blends with mineral diesel fuel. Because of the limited availability of fossil resources, an increase of biogenic compounds in fuels is desired. To achieve this goal, next to rapeseed oil, other sustainably produced vegetable oils can be used as raw materials. These raw materials influence the fuel properties as well as the emissions. To investigate the environmental impact of the exhaust gas, it is necessary to determine regulated and non-regulated exhaust gas components. In detail, emissions of aldehydes and polycyclic aromatic hydrocarbons (PAH), as well as mutagenicity in the Ames test are of special interest. In this paper emission measurements on a Euro III engine OM 906 of Mercedes-Benz are presented. As fuel vegetable oil methyl esters from various sources and reference diesel fuel were used as well as blends of the vegetable oil methyl esters with diesel fuel. PAH were sampled according to VDI Guideline 3872. The sampling procedure of carbonyls was accomplished using DNPH cartridges coupled with potassium iodide cartridges. The carbon monoxide and hydrocarbon emissions of the tested methyl esters show advantages over DF. The particle mass emissions of methyl esters were likewise lower than those of DF, only linseed oil methyl ester showed higher particle mass emissions. A disadvantage is the use of biodiesel with respect to emissions of nitrogen oxides. They increased depending on the type of methyl ester by 10% to 30%. Emissions of polycyclic aromatic hydrocarbons (PAHs) and the results of mutagenicity tests correlate with those of the PM measurements, at which for palm oil methyl ester next to coconut oil methyl ester the lowest emissions were detected. From these results one can formulate a clear link between the iodine number of the ester and the emission behaviour. For blends of biodiesel and diesel fuel, emissions changed linearly with the proportion of biodiesel. However, especially in the non

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 ...

Identification of Aroma Compounds of Lamiaceae Species in Turkey Using the Purge and Trap Technique

PubMed Central

Sonmezdag, Ahmet Salih; Kelebek, Hasim; Selli, Serkan

2017-01-01

The present research was planned to characterize the aroma composition of important members of the Lamiaceae family such as Salvia officinalis, Lavandula angustifolia and Mentha asiatica. Aroma components of the S. officinalis, L. angustifolia and M. asiatica were extracted with the purge and trap technique with dichloromethane and analyzed with the gas chromatography–mass spectrometry (GC–MS) technique. A total of 23, 33 and 33 aroma compounds were detected in Salvia officinalis, Lavandula angustifolia and Mentha asiatica, respectively including, acids, alcohols, aldehydes, esters, hydrocarbons and terpenes. Terpene compounds were both qualitatively and quantitatively the major chemical group among the identified aroma compounds, followed by esters. The main terpene compounds were 1,8-cineole, sabinene and linalool in Salvia officinalis, Lavandula angustifolia and Mentha asiatica, respectively. Among esters, linalyl acetate was the only and most important ester compound which was detected in all samples. PMID:28231089

Human class II (pi) alcohol dehydrogenase has a redox-specific function in norepinephrine metabolism.

PubMed Central

Mårdh, G; Dingley, A L; Auld, D S; Vallee, B L

1986-01-01

Studies of the function of human alcohol dehydrogenase (ADH) have revealed substrates that are virtually unique for class II ADH (pi ADH). It catalyzes the formation of the intermediary glycols of norepinephrine metabolism, 3,4-dihydroxyphenylglycol and 4-hydroxy-3-methoxyphenylglycol, from the corresponding aldehydes 3,4-dihydroxymandelaldehyde and 4-hydroxy-3-methoxymandelaldehyde with Km values of 55 and 120 microM and kcat/Km ratios of 14,000 and 17,000 mM-1 X min-1; these are from 60- to 210-fold higher than those obtained with class I ADH isozymes. The catalytic preference of class II ADH also extends to benzaldehydes. The kcat/Km values for the reduction of benzaldehyde, 3,4-dihydroxybenzaldehyde and 4-hydroxy-3-methoxybenzaldehyde by pi ADH are from 9- to 29-fold higher than those for a class I isozyme, beta 1 gamma 2 ADH. Furthermore, the norepinephrine aldehydes are potent inhibitors of alcohol (ethanol) oxidation by pi ADH. The high catalytic activity of pi ADH-catalyzed reduction of the aldehydes in combination with a possible regulatory function of the aldehydes in the oxidative direction leads to essentially "unidirectional" catalysis by pi ADH. These features and the presence of pi ADH in human liver imply a physiological role for pi ADH in the degradation of circulating epinephrine and norepinephrine. PMID:3466164

Three-Component Reactions of Diazoesters, Aldehydes, and Imines Using a Dual Catalytic System Consisting of a Rhodium(II) Complex and a Lewis Acid.

PubMed

Toda, Yasunori; Kaku, Wakatake; Tsuruoka, Makoto; Shinogaki, Sho; Abe, Tomoka; Kamiya, Hideaki; Kikuchi, Ayaka; Itoh, Kennosuke; Suga, Hiroyuki

2018-05-04

A dual catalytic system, dirhodium tetrapivalate/ytterbium(III) triflate, enables the three-component reactions of α-alkyl-α-diazoesters, aromatic aldehydes, and N-benzylidenebenzylamine derivatives to afford the corresponding β-amino alcohols in good yields after hydrolysis of the oxazolidine cycloadducts, whereas no β-amino alcohols are obtained in the absence of ytterbium(III) triflate. A similar dual catalytic system, dirhodium tetraacetate/ytterbium(III) triflate, is found to be effective in accelerating the reactions of α-aryl-α-diazoesters in high yields. Furthermore, the reactions using dimethyl diazomalonate are described.

Five Fatty Acyl-Coenzyme A Reductases Are Involved in the Biosynthesis of Primary Alcohols in Aegilops tauschii Leaves

PubMed Central

Wang, Meiling; Wu, Hongqi; Xu, Jing; Li, Chunlian; Wang, Yong; Wang, Zhonghua

2017-01-01

The diploid Aegilops tauschii is the D-genome donor to hexaploid wheat (Triticum aestivum) and represents a potential source for genetic study in common wheat. The ubiquitous wax covering the aerial parts of plants plays an important role in protecting plants against non-stomatal water loss. Cuticular waxes are complex mixtures of very-long-chain fatty acids, alkanes, primary and/or secondary alcohols, aldehydes, ketones, esters, triterpenes, sterols, and flavonoids. In the present work, primary alcohols were identified as the major components of leaf cuticular wax in Ae. tauschii, with C26:0-OH being the dominant primary alcohol. Analysis by scanning electron microscope revealed that dense platelet-shaped wax crystals were deposited on leaf surfaces of Ae. tauschii. Ten putative wax biosynthetic genes encoding fatty acyl-coenzyme A reductase (FAR) were identified in the genome of Ae. tauschii. Five of these genes, Ae.tFAR1, Ae.tFAR2, Ae.tFAR3, Ae.tFAR4, and Ae.tFAR6, were found expressed in the leaf blades. Heterologous expression of the five Ae.tFARs in yeast (Saccharomyces cerevisiae) showed that Ae.tFAR1, Ae.tFAR2, Ae.tFAR3, Ae.tFAR4, and Ae.tFAR6 were predominantly responsible for the accumulation of C16:0, C18:0, C26:0, C24:0, and C28:0 primary alcohols, respectively. In addition, nine Ae.tFAR paralogous genes were located on D chromosome of wheat and the wheat nullisomic–tetrasomic lines with the loss of Ae.tFAR3 and Ae.tFAR4 paralogous genes had significantly reduced levels of primary alcohols in the leaf blades. Collectively, these data suggest that Ae.tFAR1, Ae.tFAR2, Ae.tFAR3, Ae.tFAR4, and Ae.tFAR6 encode alcohol-forming FARs involved in the biosynthesis of primary alcohols in the leaf blades of Ae. tauschii. The information obtained in Ae. tauschii enables us to better understand wax biosynthesis in common wheat. PMID:28659955

Approaches for the Analysis of Chlorinated Lipids

PubMed Central

Wang, Wen-yi; Albert, Carolyn J.; Ford, David A.

2013-01-01

Leukocytes are key cellular mediators of human diseases through their role in inflammation. Identifying unique molecules produced by leukocytes may provide new biomarkers and mechanistic insights into the role of leukocytes in disease. Chlorinated lipids are generated as a result of myeloperoxidase-containing leukocyte-derived hypochlorous acid targeting the vinyl ether bond of plasmalogens. The initial product of this reaction is α-chlorofatty aldehyde. α -Chlorofatty aldehyde is both oxidized to α-chlorofatty acid and reduced to α-chlorofatty alcohol by cellular metabolism. This review focuses on the separation techniques and quantitative analysis for these chlorinated lipids. For α-chlorofatty acid the negative charge of carboxylic acids is exploited to detect the chlorinated lipid species of these acids by electrospray ionization mass spectrometry in the negative ion mode. In contrast, α-chlorofatty aldehyde and α-chlorofatty alcohol are converted to pentafluorobenzyl oxime and pentafluorobenzoyl ester derivatives, which are detected by negative ion-chemical ionization mass spectrometry. These two detection methods coupled with the use of stable isotope internal standards and either liquid chromatography or gas chromatography provide highly sensitive analytical approaches to measure these novel lipids. PMID:24056259

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.

Chiral Brønsted Acid-Catalyzed Allylboration of Aldehydes

PubMed Central

Jain, Pankaj; Antilla, Jon C.

2010-01-01

The catalytic enantioselective allylation of aldehydes is a long-standing problem with considerable interest to the chemical community. We wish to disclose a new high yielding and highly enantioselective chiral Brønsted acid-catalyzed allylboration of aldehydes. The reaction is shown to be highly general, with broad substrate scope that covers aryl, heteroaryl, α,β-unsaturated, and aliphatic aldehydes. The reaction conditions were also shown to be effective for the catalytic enantioselective crotylation of aldehydes. We believe that the high reactivity of the allyl boronate is due to protonation of the boronate oxygen by the chiral phosphoric acid catalyst. PMID:20690662

Quantification of fatty acid ethyl esters (FAEE) and ethyl glucuronide (EtG) in meconium for detection of alcohol abuse during pregnancy: Correlation study between both biomarkers.

PubMed

Cabarcos, Pamela; Tabernero, María Jesús; Otero, José Luís; Míguez, Martha; Bermejo, Ana María; Martello, Simona; De Giovanni, Nadia; Chiarotti, Marcello

2014-11-01

This article presents results from 47 meconium samples, which were analyzed for fatty acid ethyl esters (FAEE) and ethyl glucuronide (EtG) for detection of gestational alcohol consumption. A validated microwave assisted extraction (MAE) method in combination with GC-MS developed in the Institute of Forensic Science (Santiago de Compostela) was used for FAEE and the cumulative concentration of ethyl myristate, ethyl palmitate and ethyl stearate with a cut-off of 600ng/g was applied for interpretation. A simple method for identification and quantification of EtG has been evaluated by ultrasonication followed solid phase extraction (SPE). Successful validation parameters were obtained for both biochemical markers of alcohol intake. FAEE and EtG concentrations in meconium ranged between values lower than LOD and 32,892ng/g or 218ng/g respectively. We have analyzed FAEE and EtG in the same meconium aliquot, enabling comparison of the efficiency of gestational ethanol exposure detection. Certain agreement between the two biomarkers was found as they are both a very specific alcohol markers, making it a useful analysis for confirmation. Copyright © 2014 Elsevier B.V. All rights reserved.

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. Copyright © 2016 Elsevier B.V. All rights reserved.

Colorimetric Recognition of Aldehydes and Ketones.

PubMed

Li, Zheng; Fang, Ming; LaGasse, Maria K; Askim, Jon R; Suslick, Kenneth S

2017-08-07

A colorimetric sensor array has been designed for the identification of and discrimination among aldehydes and ketones in vapor phase. Due to rapid chemical reactions between the solid-state sensor elements and gaseous analytes, distinct color difference patterns were produced and digitally imaged for chemometric analysis. The sensor array was developed from classical spot tests using aniline and phenylhydrazine dyes that enable molecular recognition of a wide variety of aliphatic or aromatic aldehydes and ketones, as demonstrated by hierarchical cluster, principal component, and support vector machine analyses. The aldehyde/ketone-specific sensors were further employed for differentiation among and identification of ten liquor samples (whiskies, brandy, vodka) and ethanol controls, showing its potential applications in the beverage industry. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Transesterification process to manufacture ethyl ester of rape oil

DOE Office of Scientific and Technical Information (OSTI.GOV)

Korus, R.A.; Hoffman, D.S.; Bam, N.

1993-12-31

A process for the production of the ethyl ester of winter rape [EEWR] for use as a biodiesel fuel has been studied. The essential part of the process is the transesterification of rape oil with ethanol, in the presence of a catalyst, to yield the ethyl ester of rape oil as a product and glycerin as a by-product. Experiments have been performed to determine the optimum conditions for the preparation of EEWR. The process variables were: (1) temperature, (2) catalyst, (3) rate of agitation, (4) water content of the alcohol used, and (5) the amount of excess alcohol used. Themore » optimum conditions were: (1) room temperature, (2) 0.5% sodium methoxide or 1% potassium hydroxide catalyst by weight of rapeseed oil, (3) extremely vigorous agitation with some splashing during the initial phase of the reaction and agitation was not necessary after the reaction mixture became homogeneous, (4) absolute ethanol was necessary for high conversion, and (5) 50% excess ethanol with NaOCH{sub 3} or 100% excess with KOH gave a maximum conversion. Viscosity, cloud point and pour point of the EEWR were measured. A preliminary break-even cost for the commercial production of EEWR was found to be $0.55/liter [$2.08/US gallon].« less

Cigarette Filter Ventilation and Smoking Protocol Influence Aldehyde Smoke Yields

PubMed Central

2018-01-01

The WHO study group on tobacco product regulation (TobReg) advised regulating and lowering toxicant levels in cigarette smoke. Aldehydes are one of the chemical classes on the TobReg smoke toxicants priority list. To provide insight in factors determining aldehyde yields, the levels of 12 aldehydes in mainstream cigarette smoke of 11 Dutch brands were quantified. Variations in smoking behavior and cigarette design affecting human exposure to aldehydes were studied by using four different machine testing protocols. Machine smoking was based on the International Standardization Organization (ISO) and Health Canada Intense (HCI) regime, both with and without taping the filter vents. The 11 cigarette brands differed in (i) design and blend characteristics; (ii) tar, nicotine, and carbon monoxide (TNCO) levels; (iii) popularity; and (iv) manufacturer. Cigarette smoke was trapped on a Cambridge filter pad and carboxen cartridge. After being dissolved in methanol/CS2 and derivatization with DNPH, the aldehyde yields were determined using HPLC-DAD. Using an intense smoking regime (increased puff volume, shorter puff interval) significantly increased aldehyde yields, following the pattern: ISO < ISO-taped < HCI-untaped < HCI. For all of the regimes, acetaldehyde and acrolein yields were strongly correlated (r = 0.804). The difference in TNCO and aldehyde levels between regular and highly ventilated low-TNCO cigarettes (as measured using ISO) diminished when smoking intensely; this effect is stronger when combined with taping filter vents. The highly ventilated low-TNCO brands showed six times more aldehyde production per mg nicotine for the intense smoking regimes. In conclusion, acetaldehyde and acrolein can be used as representatives for the class of volatile aldehydes for the different brands and smoking regimes. The aldehyde-to-nicotine ratio increased when highly ventilated cigarettes were smoked intensely, similar to real smokers. Thus, a smoker of highly ventilated

Effect of Alcohols on the Phase Behavior and Emulsification of a Sucrose Fatty Acid Ester/Water/Edible Oil System.

PubMed

Matsuura, Tsutashi; Ogawa, Akihiro; Ohara, Yukari; Nishina, Shogo; Nakanishi, Maho; Gohtani, Shoichi

2018-02-01

The effect of alcohols (ethanol, 1-propanol, propylene glycol, glycerin, sucrose) on the phase behavior and emulsification of sucrose stearic acid ester (SSE)/water/edible vegetable oil (EVO) systems was investigated. Adding sucrose, propylene glycol, and glycerin narrowed the oil-separated two-phase region in the phase diagram of the SSE/water/EVO systems, whereas adding ethanol and 1-propanol expanded the oil-separated two-phase region. Changing the course of emulsification in the phase diagram showed that the size of the oil-droplet particle typically decreased in a system with a narrowed oil-separated region. The emulsification properties of the systems varied with respect to changes in the phase diagram. The microstructure of the systems was examined using small-angle X-ray scattering, and the ability to retain the oil in the lamellar structure of the SSEs was suggested as an important role in emulsification, because the mechanism of the systems was the same as that for the liquid crystal emulsification method.

Predictive analysis of beer quality by correlating sensory evaluation with higher alcohol and ester production using multivariate statistics methods.

PubMed

Dong, Jian-Jun; Li, Qing-Liang; Yin, Hua; Zhong, Cheng; Hao, Jun-Guang; Yang, Pan-Fei; Tian, Yu-Hong; Jia, Shi-Ru

2014-10-15

Sensory evaluation is regarded as a necessary procedure to ensure a reproducible quality of beer. Meanwhile, high-throughput analytical methods provide a powerful tool to analyse various flavour compounds, such as higher alcohol and ester. In this study, the relationship between flavour compounds and sensory evaluation was established by non-linear models such as partial least squares (PLS), genetic algorithm back-propagation neural network (GA-BP), support vector machine (SVM). It was shown that SVM with a Radial Basis Function (RBF) had a better performance of prediction accuracy for both calibration set (94.3%) and validation set (96.2%) than other models. Relatively lower prediction abilities were observed for GA-BP (52.1%) and PLS (31.7%). In addition, the kernel function of SVM played an essential role of model training when the prediction accuracy of SVM with polynomial kernel function was 32.9%. As a powerful multivariate statistics method, SVM holds great potential to assess beer quality. Copyright © 2014 Elsevier Ltd. All rights reserved.

Development of an azanoradamantane-type nitroxyl radical catalyst for class-selective oxidation of alcohols.

PubMed

Doi, Ryusuke; Shibuya, Masatoshi; Murayama, Tsukasa; Yamamoto, Yoshihiko; Iwabuchi, Yoshiharu

2015-01-02

The development of 1,5-dimethyl-9-azanoradamantane N-oxyl (DMN-AZADO; 1,5-dimethyl-Nor-AZADO, 2) as an efficient catalyst for the selective oxidation of primary alcohols in the presence of secondary alcohols is described. The compact and rigid structure of the azanoradamantane nucleus confers potent catalytic ability to DMN-AZADO (2). A variety of hindered primary alcohols such as neopentyl primary alcohols were efficiently oxidized by DMN-AZADO (2) to the corresponding aldehydes, whereas secondary alcohols remained intact. DMN-AZADO (2) also has high catalytic efficiency for one-pot oxidation from primary alcohols to the corresponding carboxylic acids in the presence of secondary alcohols and for oxidative lactonization from diols.

Photochemical dimerization and functionalization of alkanes, ethers, primary alcohols and silanes

DOEpatents

Crabtree, Robert H.; Brown, Stephen H.

1988-01-01

The space-time yield and/or the selectivity of the photochemical dimerization of alkanes, ethers, primary alcohols and tertiary silanes with Hg and U.V. light is enhanced by refluxing the substrate in the irradiated reaction zone at a temperature at which the dimer product condenses and remains condensed promptly upon its formation. Cross-dimerization of the alkanes, ethers and silanes with primary alcohols is disclosed, as is the functionalization to aldehydes of the alkanes with carbon monoxide.

Photochemical dimerization and functionalization of alkanes, ethers, primary alcohols and silanes

DOEpatents

Crabtree, R.H.; Brown, S.H.

1988-02-16

The space-time yield and/or the selectivity of the photochemical dimerization of alkanes, ethers, primary alcohols and tertiary silanes with Hg and U.V. light is enhanced by refluxing the substrate in the irradiated reaction zone at a temperature at which the dimer product condenses and remains condensed promptly upon its formation. Cross-dimerization of the alkanes, ethers and silanes with primary alcohols is disclosed, as is the functionalization to aldehydes of the alkanes with carbon monoxide.

Volatile Ester Formation in Roses. Identification of an Acetyl-Coenzyme A. Geraniol/Citronellol Acetyltransferase in Developing Rose Petals1

PubMed Central

Shalit, Moshe; Guterman, Inna; Volpin, Hanne; Bar, Einat; Tamari, Tal; Menda, Naama; Adam, Zach; Zamir, Dani; Vainstein, Alexander; Weiss, David; Pichersky, Eran; Lewinsohn, Efraim

2003-01-01

The aroma of roses (Rosa hybrida) is due to more than 400 volatile compounds including terpenes, esters, and phenolic derivatives. 2-Phenylethyl acetate, cis-3-hexenyl acetate, geranyl acetate, and citronellyl acetate were identified as the main volatile esters emitted by the flowers of the scented rose var. “Fragrant Cloud.” Cell-free extracts of petals acetylated several alcohols, utilizing acetyl-coenzyme A, to produce the corresponding acetate esters. Screening for genes similar to known plant alcohol acetyltransferases in a rose expressed sequence tag database yielded a cDNA (RhAAT1) encoding a protein with high similarity to several members of the BAHD family of acyltransferases. This cDNA was functionally expressed in Escherichia coli, and its gene product displayed acetyl-coenzyme A:geraniol acetyltransferase enzymatic activity in vitro. The RhAAT1 protein accepted other alcohols such as citronellol and 1-octanol as substrates, but 2-phenylethyl alcohol and cis-3-hexen-1-ol were poor substrates, suggesting that additional acetyltransferases are present in rose petals. The RhAAT1 protein is a polypeptide of 458 amino acids, with a calculated molecular mass of 51.8 kD, pI of 5.45, and is active as a monomer. The RhAAT1 gene was expressed exclusively in floral tissue with maximum transcript levels occurring at stage 4 of flower development, where scent emission is at its peak. PMID:12692346

Expanding the chemical diversity of natural esters by engineering a polyketide-derived pathway into Escherichia coli.

PubMed

Menendez-Bravo, Simón; Comba, Santiago; Sabatini, Martín; Arabolaza, Ana; Gramajo, Hugo

2014-07-01

Microbial fatty acid (FA)-derived molecules have emerged as promising alternatives to petroleum-based chemicals for reducing dependence on fossil hydrocarbons. However, native FA biosynthetic pathways often yield limited structural diversity, and therefore restricted physicochemical properties, of the end products by providing only a limited variety of usually linear hydrocarbons. Here we have engineered into Escherichia coli a mycocerosic polyketide synthase-based biosynthetic pathway from Mycobacterium tuberculosis and redefined its biological role towards the production of multi-methyl-branched-esters (MBEs) with novel chemical structures. Expression of FadD28, Mas and PapA5 enzymes enabled the biosynthesis of multi-methyl-branched-FA and their further esterification to an alcohol. The high substrate tolerance of these enzymes towards different FA and alcohol moieties resulted in the biosynthesis of a broad range of MBE. Further metabolic engineering of the MBE producer strain coupled this system to long-chain-alcohol biosynthetic pathways resulting in de novo production of branched wax esters following addition of only propionate. Copyright © 2014 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

21 CFR 182.60 - Synthetic flavoring substances and adjuvants.

Code of Federal Regulations, 2014 CFR

2014-04-01

... aldehyde). N-Butyric acid (butanoic acid). d- or l-Carvone (carvol). Cinnamaldehyde (cinnamic aldehyde... aldehyde, caprinaldehyde, aldehyde C-10). Ethyl acetate. Ethyl butyrate. 3-Methyl-3-phenyl glycidic acid ethyl ester (ethyl-methyl-phenyl-glycidate, so-called strawberry aldehyde, C-16 aldehyde). Ethyl...

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

Release and Formation of Oxidation-Related Aldehydes during Wine Oxidation.

PubMed

Bueno, Mónica; Carrascón, Vanesa; Ferreira, Vicente

2016-01-27

Twenty-four Spanish wines were subjected to five consecutive cycles of air saturation at 25 °C. Free and bound forms of carbonyls were measured in the initial samples and after each saturation. Nonoxidized commercial wines contain important and sensory relevant amounts of oxidation-related carbonyls under the form of odorless bound forms. Models relating the contents in total aldehydes to the wine chemical composition suggest that fermentation can be a major origin for Strecker aldehydes: methional, phenylacetaldehyde, isobutyraldehyde, 2-methylbutanal, and isovaleraldehyde. Bound forms are further cleaved, releasing free aldehydes during the first steps of wine oxidation, as a consequence of equilibrium shifts caused by the depletion of SO2. At low levels of free SO2, de novo formation and aldehyde degradation are both observed. The relative importance of these phenomena depends on both the aldehyde and the wine. Models relating aldehyde formation rates to wine chemical composition suggest that amino acids are in most cases the most important precursors for de novo formation.

Poly(ether ester) Ionomers as Water-Soluble Polymers for Material Extrusion Additive Manufacturing Processes.

PubMed

Pekkanen, Allison M; Zawaski, Callie; Stevenson, André T; Dickerman, Ross; Whittington, Abby R; Williams, Christopher B; Long, Timothy E

2017-04-12

Water-soluble polymers as sacrificial supports for additive manufacturing (AM) facilitate complex features in printed objects. Few water-soluble polymers beyond poly(vinyl alcohol) enable material extrusion AM. In this work, charged poly(ether ester)s with tailored rheological and mechanical properties serve as novel materials for extrusion-based AM at low temperatures. Melt transesterification of poly(ethylene glycol) (PEG, 8k) and dimethyl 5-sulfoisophthalate afforded poly(ether ester)s of sufficient molecular weight to impart mechanical integrity. Quantitative ion exchange provided a library of poly(ether ester)s with varying counterions, including both monovalent and divalent cations. Dynamic mechanical and tensile analysis revealed an insignificant difference in mechanical properties for these polymers below the melting temperature, suggesting an insignificant change in final part properties. Rheological analysis, however, revealed the advantageous effect of divalent countercations (Ca 2+ , Mg 2+ , and Zn 2+ ) in the melt state and exhibited an increase in viscosity of two orders of magnitude. Furthermore, time-temperature superposition identified an elevation in modulus, melt viscosity, and flow activation energy, suggesting intramolecular interactions between polymer chains and a higher apparent molecular weight. In particular, extrusion of poly(PEG 8k -co-CaSIP) revealed vast opportunities for extrusion AM of well-defined parts. The unique melt rheological properties highlighted these poly(ether ester) ionomers as ideal candidates for low-temperature material extrusion additive manufacturing of water-soluble parts.

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

Origin and dispersal of atypical aldehyde dehydrogenase ALDH2487Lys.

PubMed

Luo, Huai-Rong; Wu, Gui-Sheng; Pakstis, Andrew J; Tong, Li; Oota, Hiroki; Kidd, Kenneth K; Zhang, Ya-Ping

2009-04-15

The East Asian respond with a marked facial flushing and mild to moderate symptoms of intoxication after drinking the amounts of alcohol that has no detectable effect on European. The alcohol sensitivity in Orientals is due to a delayed oxidation of acetaldehyde by an atypical aldehyde dehydrogenase ALDH2487Lys, which is resulted from a structural mutation in gene ALDH2. The atypical ALDH2487Lys allele has been associated with various phenotypic statuses, such as protective against alcohol dependence and the risk of alcohol-related digestive tract cancers. Here, we have examined this SNP, adjacent four non-coding SNPs, and one downstream STRP on ALDH2 gene, in total of 1072 unrelated healthy individuals from 14 Chinese populations and 130 Indian individuals. Five major haplotypes based on five SNPs across the ALDH2 gene 40 kb were found in all East Asian populations. The frequencies of the ancestral haplotype GCCTG and the East Asian special haplotype GCCTA containing the atypical ALDH2487Lys allele were 44.8% and 14.9%, respectively. The frequency of the atypical ALDH2487Lys allele or the East Asian specific haplotype GCCTA is high in Yunnan, South coastal, east coastal of China, and decreased gradually toward inland China, West, Northwest and North China. Combined with demographic history in East Asian, our results showed that the presence of ALDH2487Lys allele in peripheral regions of China might be the results of historical migration events from China to these regions. The origin of ALDH2487Lys could be possibly traced back to ancient Pai-Yuei tribe in South China.

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 PAGES

Coursolle, Dan; Shanklin, John; Lian, Jiazhang; ...

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

Aromatic aldehydes at the active site of aldehyde oxidoreductase from Desulfovibrio gigas: reactivity and molecular details of the enzyme-substrate and enzyme-product interaction.

PubMed

Correia, Hugo D; Marangon, Jacopo; Brondino, Carlos D; Moura, Jose J G; Romão, Maria J; González, Pablo J; Santos-Silva, Teresa

2015-03-01

Desulfovibrio gigas aldehyde oxidoreductase (DgAOR) is a mononuclear molybdenum-containing enzyme from the xanthine oxidase (XO) family, a group of enzymes capable of catalyzing the oxidative hydroxylation of aldehydes and heterocyclic compounds. The kinetic studies reported in this work showed that DgAOR catalyzes the oxidative hydroxylation of aromatic aldehydes, but not heterocyclic compounds. NMR spectroscopy studies using (13)C-labeled benzaldehyde confirmed that DgAOR catalyzes the conversion of aldehydes to the respective carboxylic acids. Steady-state kinetics in solution showed that high concentrations of the aromatic aldehydes produce substrate inhibition and in the case of 3-phenyl propionaldehyde a suicide substrate behavior. Hydroxyl-substituted aromatic aldehydes present none of these behaviors but the kinetic parameters are largely affected by the position of the OH group. High-resolution crystallographic structures obtained from single crystals of active-DgAOR soaked with benzaldehyde showed that the side chains of Phe425 and Tyr535 are important for the stabilization of the substrate in the active site. On the other hand, the X-ray data of DgAOR soaked with trans-cinnamaldehyde showed a cinnamic acid molecule in the substrate channel. The X-ray data of DgAOR soaked with 3-phenyl propionaldehyde showed clearly how high substrate concentrations inactivate the enzyme by binding covalently at the surface of the enzyme and blocking the substrate channel. The different reactivity of DgAOR versus aldehyde oxidase and XO towards aromatic aldehydes and N-heterocyclic compounds is explained on the basis of the present kinetic and structural data.

Increased salivary aldehyde dehydrogenase 1 in non-reticular oral lichen planus.

PubMed

Mansourian, Arash; Shanbehzadeh, Najmeh; Kia, Seyed Javad; Moosavi, Mahdieh-Sadat

2017-01-01

Oral lichen planus is a potentially malignant disorder. One of the malignant transformation markers is cancer stem cells. One of the proposed marker for the detection of cancer stem cells's in head and neck cancer is aldehyde dehydrogenase. Recently it is shown that aldehyde dehydrogenase 1 expression in tissue samples is associated with oral lichen planus malignant transformation. This study evaluates salivary aldehyde dehydrogenase 1 in oral lichen planus. Thirty patients and 30 age and sex-matched healthy volunteers were recruited. Oral lichen planus was diagnosed based on the modified World Health Organization criteria. Subjects in the case group were divided into reticular and non-reticular forms. Unstimulated salivary samples were collected at 10-12 AM. Saliva concentrations of aldehyde dehydrogenase 1 were measured by ELISA. The differences between aldehyde dehydrogenase levels in the oral lichen planus group compared with the control group were not significant but aldehyde dehydrogenase in non-reticular oral lichen planus was significantly higher than that of the reticular form. This is a cross-sectional study, thus longitudinal studies in oral lichen planus may present similar or different results. The mechanism of malignant transformation in oral lichen planus is not defined. Previous analyses revealed that the aldehyde dehydrogenase 1 expression is significantly correlated with increased risk of transformation. This finding is consistent with our results because in the erosive and ulcerative forms of oral lichen planus, which have an increased risk of transformation, salivary aldehyde dehydrogenase 1 was overexpressed. A higher salivary aldehyde dehydrogenase level in non-reticular oral lichen planus can be a defensive mechanism against higher oxidative stress in these groups. Aldehyde dehydrogenase may be one of the malignant transformation markers in oral lichen planus. Further studies are needed for introducing aldehyde dehydrogenase as a prognostic

Increased salivary aldehyde dehydrogenase 1 in non-reticular oral lichen planus*

PubMed Central

Mansourian, Arash; Shanbehzadeh, Najmeh; Kia, Seyed Javad; Moosavi, Mahdieh-Sadat

2017-01-01

Background Oral lichen planus is a potentially malignant disorder. One of the malignant transformation markers is cancer stem cells. One of the proposed marker for the detection of cancer stem cells's in head and neck cancer is aldehyde dehydrogenase. Recently it is shown that aldehyde dehydrogenase 1 expression in tissue samples is associated with oral lichen planus malignant transformation. Objective This study evaluates salivary aldehyde dehydrogenase 1 in oral lichen planus. Method Thirty patients and 30 age and sex-matched healthy volunteers were recruited. Oral lichen planus was diagnosed based on the modified World Health Organization criteria. Subjects in the case group were divided into reticular and non-reticular forms. Unstimulated salivary samples were collected at 10-12 AM. Saliva concentrations of aldehyde dehydrogenase 1 were measured by ELISA. Results The differences between aldehyde dehydrogenase levels in the oral lichen planus group compared with the control group were not significant but aldehyde dehydrogenase in non-reticular oral lichen planus was significantly higher than that of the reticular form. Limitations of the study This is a cross-sectional study, thus longitudinal studies in oral lichen planus may present similar or different results. Conclusions The mechanism of malignant transformation in oral lichen planus is not defined. Previous analyses revealed that the aldehyde dehydrogenase 1 expression is significantly correlated with increased risk of transformation. This finding is consistent with our results because in the erosive and ulcerative forms of oral lichen planus, which have an increased risk of transformation, salivary aldehyde dehydrogenase 1 was overexpressed. A higher salivary aldehyde dehydrogenase level in non-reticular oral lichen planus can be a defensive mechanism against higher oxidative stress in these groups. Aldehyde dehydrogenase may be one of the malignant transformation markers in oral lichen planus. Further

Influence of alcohol containing and alcohol free cosmetics on FAEE concentrations in hair. A performance evaluation of ethyl palmitate as sole marker, versus the sum of four FAEEs.

PubMed

Dumitrascu, C; Paul, R; Kingston, R; Williams, Rachel

2018-02-01

Fatty acid ethyl esters (FAEE) are direct metabolites of ethanol and have been shown to be suitable markers for the evaluation of alcohol consumption. Previous research has suggested that the regular use of alcohol containing cosmetic products can influence the concentration of FAEE detected in hair. In this study we investigated the influence of alcohol containing and alcohol free hair cosmetics (hairspray and waxes) on the FAEE concentrations in hair. The effect of cosmetic treatment was measured against the impact on ethyl palmitate in isolation as compared to the sum of four esters. 10 volunteers treated part of their scalp with cosmetic products every day during a 2 month period (alcohol free hairspray n=2, hairspray containing alcohol (42% by volume) n=3, alcohol free wax n=2, wax containing alcohol (11% by volume) n=3). After the 2 month period of cosmetic application hair samples from volunteers were collected from both sides of the scalp. Hair samples were washed with n-heptane, and then cut finely into small pieces. All samples were subjected to clean-up by HS-SPME and then GC PCI-MS/MS for analysis of FAEEs. Comparison of FAEE concentrations between treated and untreated hair showed in some instances that application of hair spray or wax products caused an increase in FAEE levels. Products containing alcohol caused a more substantial increase in alcohol metabolite concentrations in hair when compared to alcohol free products. Three volunteers using an alcohol based hairspray in the study experienced a significant increase in FAEE levels (+27.4%, +205.5%, and +1287.5%), with one of the volunteers showing levels below the cut off for 'abstinence' in the untreated scalp portion, and levels above the cut off for 'chronic excessive consumption' in the treated scalp portion. Performance evaluation of ethyl palmitate as sole marker, compared to the sum of four esters approach suggested that the two quantification approaches react in a very similar manner to the

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

Organic-Solvent-Free Phase-Transfer Oxidation of Alcohols Using Hydrogen Peroxide

NASA Astrophysics Data System (ADS)

Hulce, Martin; Marks, David W.

2001-01-01

Organic-solvent-free oxidations of alcohols using aqueous hydrogen peroxide in the presence of sodium tungstate and phase-transfer catalysts provide a general, safe, simple, and cost-effective means to prepare ketones. Six representative alcohols, 1-phenylethanol, 1-phenylpropanol, benzhydrol, 4-methylbenzhydrol, cis,trans-4-tert-butylcyclohexanol, and benzyl alcohol are oxidized to the corresponding aldehyde or ketone over 1-3 hours in 81-99% yields. Purities are very high, with only small to trace amounts of starting alcohol remaining. Experiments can be readily designed for one or two 3-hour laboratory periods, integrating the various techniques of extraction, drying, filtration, column chromatography, gas chromatography, NMR and IR spectroscopy, and reaction kinetics.

Preparation, characterization, and application of poly(vinyl alcohol)-graft-poly(ethylene glycol) resins: novel polymer matrices for solid-phase synthesis.

PubMed

Luo, Juntao; Pardin, Christophe; Zhu, X X; Lubell, William D

2007-01-01

Spherical crosslinked poly(vinyl alcohol) (PVA) beads with good mechanical stability were prepared by reverse-suspension polymerization, using dimethyl sulfoxide (DMSO) as a cosolvent in an aqueous phase. Poly(ethylene glycol)s with varying chain lengths were grafted onto the PVA beads by anionic polymerization of ethylene oxide. The thermal behavior, morphology, and swelling were evaluated for each of the new polymer matrices. High loading and good swelling in water and organic solvents were characteristic of the PEG-grafted PVA beads. The polymer beads also exhibited good mechanical and chemical stability and were unaffected by treatment with 6 N HCl and with 6 N NaOH. The hydroxyl groups of the PVA-PEG beads were converted into aldehyde, carboxylic acid, and isocyanate functions to provide scavenger resins and were extended by way of a benzyl alcohol in a Wang linker. The transglutaminase substrates dipeptides (Z-Gln-Gly) and heptapeptides (Pro-Asn-Pro-Gln-Leu-Pro-Phe) were synthesized on PVA-PEG_5, PVA-PEG_20, and the Wang linker-derivatized PVA-PEG resins. The cleavage of the peptides from the resins using MeOH/NH3 mixture at different temperatures (0 degrees C and room temp) and 50% TFA/DCM provided, respectively, peptide methyl esters, amides, and acids in good yields and purity as assessed by LC-MS analysis.

Determination of some volatile compounds in alcoholic beverage by headspace solid-phase microextraction gas chromatography - mass spectrometry

NASA Astrophysics Data System (ADS)

Schmutzer, G.; Avram, V.; Feher, I.; David, L.; Moldovan, Z.

2012-02-01

The volatile composition of alcoholic beverage was studied by headspace solid-phase microextraction (HSSPME) method and gas chromatography - mass spectrometry (GC-MS). Some volatile compounds, such as alcohols, esters, terpenes and other are mainly responsible for the flavor of fortified wines and their amounts specify the quality of the alcoholic beverages. From this perspective it is interesting to develop a rapid, selective and sensitive analytical method suitable for simultaneous quantification of the main molecules being responsible for the organoleptic characteristic of alcoholic beverages. Vermouth fortified drink was analyzed in order to characterize the volatile profile. Using the HS-SPME/GC-MS a number of twenty-six volatile compounds from a commercial market alcoholic beverage were identified. The most abundant compounds were m-thymol, o-thymol and eugenol, alongside of the ethyl ester compounds.

CER4 Encodes an Alcohol-Forming Fatty Acyl-Coenzyme A Reductase Involved in Cuticular Wax Production in Arabidopsis1[W

PubMed Central

Rowland, Owen; Zheng, Huanquan; Hepworth, Shelley R.; Lam, Patricia; Jetter, Reinhard; Kunst, Ljerka

2006-01-01

A waxy cuticle that serves as a protective barrier against uncontrolled water loss and environmental damage coats the aerial surfaces of land plants. It is composed of a cutin polymer matrix and waxes. Cuticular waxes are complex mixtures of very-long-chain fatty acids and their derivatives. We report here the molecular cloning and characterization of CER4, a wax biosynthetic gene from Arabidopsis (Arabidopsis thaliana). Arabidopsis cer4 mutants exhibit major decreases in stem primary alcohols and wax esters, and slightly elevated levels of aldehydes, alkanes, secondary alcohols, and ketones. This phenotype suggested that CER4 encoded an alcohol-forming fatty acyl-coenzyme A reductase (FAR). We identified eight FAR-like genes in Arabidopsis that are highly related to an alcohol-forming FAR expressed in seeds of jojoba (Simmondsia chinensis). Molecular characterization of CER4 alleles and genomic complementation revealed that one of these eight genes, At4g33790, encoded the FAR required for cuticular wax production. Expression of CER4 cDNA in yeast (Saccharomyces cerevisiae) resulted in the accumulation of C24:0 and C26:0 primary alcohols. Fully functional green fluorescent protein-tagged CER4 protein was localized to the endoplasmic reticulum in yeast cells by confocal microscopy. Analysis of gene expression by reverse transcription-PCR indicated that CER4 was expressed in leaves, stems, flowers, siliques, and roots. Expression of a β-glucuronidase reporter gene driven by the CER4 promoter in transgenic plants was detected in epidermal cells of leaves and stems, consistent with a dedicated role for CER4 in cuticular wax biosynthesis. CER4 was also expressed in all cell types in the elongation zone of young roots. These data indicate that CER4 is an alcohol-forming FAR that has specificity for very-long-chain fatty acids and is responsible for the synthesis of primary alcohols in the epidermal cells of aerial tissues and in roots. PMID:16980563

Synthesis of oleyl oleate wax esters in Arabidopsis thaliana and Camelina sativa seed oil.

PubMed

Iven, Tim; Hornung, Ellen; Heilmann, Mareike; Feussner, Ivo

2016-01-01

Seed oil composed of wax esters with long-chain monoenoic acyl moieties represents a high-value commodity for industry. Such plant-derived sperm oil-like liquid wax esters are biodegradable and can have excellent properties for lubrication. In addition, wax ester oil may represent a superior substrate for biodiesel production. In this study, we demonstrate that the low-input oil seed crop Camelina sativa can serve as a biotechnological platform for environmentally benign wax ester production. Two biosynthetic steps catalysed by a fatty alcohol-forming acyl-CoA reductase (FAR) and a wax ester synthase (WS) are sufficient to achieve wax ester accumulation from acyl-CoA substrates. To produce plant-derived sperm oil-like liquid wax esters, the WS from Mus musculus (MmWS) or Simmondsia chinensis (ScWS) were expressed in combination with the FAR from Mus musculus (MmFAR1) or Marinobacter aquaeolei (MaFAR) in seeds of Arabidopsis thaliana and Camelina sativa. The three analysed enzyme combinations Oleo3:mCherry:MmFAR1∆c/Oleo3:EYFP:MmWS, Oleo3:mCherry:MmFAR1∆c/ScWS and MaFAR/ScWS showed differences in the wax ester molecular species profiles and overall biosynthetic performance. By expressing MaFAR/ScWS in Arabidopsis or Camelina up to 59% or 21% of the seed oil TAGs were replaced by wax esters, respectively. This combination also yielded wax ester molecular species with highest content of monounsaturated acyl moieties. Expression of the enzyme combinations in the Arabidopsis fae1 fad2 mutant background high in oleic acid resulted in wax ester accumulation enriched in oleyl oleate (18:1/18:1 > 60%), suggesting that similar values may be obtained with a Camelina high oleic acid line. © 2015 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

Colorimetric monitoring of solid-phase aldehydes using 2,4-dinitrophenylhydrazine.

PubMed

Shannon, Simon K; Barany, George

2004-01-01

A simple and rapid method to achieve colorimetric monitoring of resin-bound aldehydes, based on ambient temperature reaction with 2,4-dinitrophenylhydrazine (DNPH) in the presence of dilute acid, has been developed as an adjunct to solid-phase organic synthesis and combinatorial chemistry. By this test, the presence of aldehydes is indicated by a red to dark-orange appearance, within a minute. Alternatively, resins that are free of aldehydes or in which aldehyde functions have reacted completely retain their original color. The DNPH test was demonstrated for poly(ethylene glycol)-polystyrene (PEG-PS), aminomethyl polystyrene (AMP), cross-linked ethoxylate acrylate resin (CLEAR), and acryloylated O,O'-bis(2-aminopropyl)poly(ethylene glycol) (PEGA) supports and gave results visible to the naked eye at levels as low as 18 micromol of aldehyde per gram of resin.

Analysis of aroma compounds of pitaya fruit wine

NASA Astrophysics Data System (ADS)

Gong, Xiao; Ma, Lina; Li, Liuji; Yuan, Yuan; Peng, Shaodan; Lin, Mao

2017-12-01

In order to analyze the volatile components in red pitaya fruit wine, the study using headspace solid phase microextractionand gas chromatography-mass spectrometry technology of pitaya fruit juice and wine aroma composition analysis comparison. Results showed that 55 volatile components were detected in red pitaya fruit wine, including 12 kinds of alcohol (18.16%), 18 kinds of esters (66.17%), 7 kinds of acids (5.94%), 11 kinds of alkanes (4.32%), one kind of aldehyde (0.09%), 2 kinds of olefins (0.09%) and 3 kinds of other volatile substances (0.23%). Relative contents among them bigger have 11 species, such as decanoic acid, ethyl ester (22.92%), respectively, diisoamylene (20.75%), octanoic acid, ethyl ester (17.73%), etc. The red pitaya fruit wine contained a lot of aroma components, which offer the products special aroma like brandy, rose and fruit.

[Alcohol intake--a two-edged sword. Part 1: metabolism and pathogenic effects of alcohol].

PubMed

Ströhle, Alexander; Wolters, Maike; Hahn, Andreas

2012-08-01

From the biomedical point of view alcohol is a Janus-faced dietary component with a dose-dependent effect varying from cardiovascular protection to cytotoxicity. Alcohol is absorbed in the upper gastrointestinal tract by passive diffusion, is quickly distributed throughout body water and is mostly eliminated through oxidation. The enzymatically-catalyzed oxidative degradation to acetaldehyde and further to acetate is primarily localized in the liver. In case of a low blood alcohol concentration (<0.5 per thousand) alcohol is predominantely metabolized by the enzyme aldehyde dehydrogenase; higher blood concentrations (>0.5 per thousand) are increasingly oxidized by the microsomal ethanoloxidizing system (MEOS). Alcohol consumption induces several metabolic reactions as well as acute effects on the central nervous system. Chronic alcohol consumption to some extent irreparably damages nearly every organ with the liver being particularly concerned. There are three stages of alcohol-induced liver disease (fatty liver, alcohol hepatitis, liver cirrhosis) and the liver damages mainly result from reaction products of alcohol degradation (acetaldehyde, NADH and reactive oxygen species). An especially dreaded clinical complication of the alcohol-induced liver disease is the hepatic encephalopathy. Its pathogenesis is a multifactorial and self-perpetuating process with the swelling of astrocytes being a crucial point. Swollen astrocytes induce several reactions such as oxidative/nitrosative stress, impaired signal transduction, protein modifications and a modified gene expression profile. The swelling of astrocytes and the change in neuronal activity are attributed to several neurotoxins, especially ammonia and aromatic amino acids. In alcohol addicted subjects multiple micronutrient deficiencies are common. The status of folic acid, thiamine, pyridoxine and zinc is especially critical.

Hydrogen-bond-driven electrophilic activation for selectivity control: scope and limitations of fluorous alcohol-promoted selective formation of 1,2-disubstituted benzimidazoles and mechanistic insight for rationale of selectivity.

PubMed

Chebolu, Rajesh; Kommi, Damodara N; Kumar, Dinesh; Bollineni, Narendra; Chakraborti, Asit K

2012-11-16

Hydrogen-bond-driven electrophilic activation for selectivity control during competitive formation of 1,2-disubstituted and 2-substituted benzimidazoles from o-phenylenediamine and aldehydes is reported. The fluorous alcohols trifluoroethanol and hexafluoro-2-propanol efficiently promote the cyclocondensation of o-phenylenediamine with aldehydes to afford selectively the 1,2-disubstituted benzimidazoles at rt in short times. A mechanistic insight is invoked by NMR, mass spectrometry, and chemical studies to rationalize the selectivity. The ability of the fluorous alcohols in promoting the reaction and controlling the selectivity can be envisaged from their better hydrogen bond donor (HBD) abilities compared to that of the other organic solvents as well as of water. Due to the better HBD values, the fluorous alcohols efficiently promote the initial bisimine formation by electrophilic activation of the aldehyde carbonyl. Subsequently the hydrogen-bond-mediated activation of the in situ-formed bisimine triggers the rearrangement via 1,3-hydride shift to form the 1,2-disubstituted benzimidazoles.

Hangover symptoms in Asian Americans with variations in the aldehyde dehydrogenase (ALDH2) gene.

PubMed

Wall, T L; Horn, S M; Johnson, M L; Smith, T L; Carr, L G

2000-01-01

Hangovers are not experienced by all people and whether they contribute to the development of alcoholism is unclear. One population that might provide some insight into the role of hangover in the etiology of alcohol use disorders is that of individuals of Asian heritage. Certain Asians have lower rates of alcohol use and alcoholism, findings associated with a mutation in the aldehyde dehydrogenase (ALDH2) gene. Asians with ALDH2*2 alleles drink less and are less likely to be alcoholic than Asians without this mutation. Following alcohol ingestion, they exhibit more intense reactions to alcohol and generate higher levels of the metabolite acetaldehyde. This study evaluated hangover symptoms in Asian Americans with variations in the ALDH2 gene. Men and women of Chinese, Japanese and Korean heritage (N = 140) were asked about their drinking history and a blood sample was collected for genotyping at the ALDH2 locus. Subjects used a Likert-type scale to estimate their severity of hangover and completed a 13-item hangover scale assessing the frequency of hangover symptoms during the previous 6 months. With abstainers (n = 17) excluded and with the effects of gender and recent drinking history controlled, ALDH2 genotype accounted for a significant amount of additional variability in the estimated severity of hangover score with a similar, but nonsignificant, trend for a five-item subscale score derived from the hangover scale. These results suggest that Asian Americans with ALDH2*2 alleles may experience more severe hangovers that may contribute, in part, to protection against the development of excessive or problematic drinking in this population.

Aldehyde dehydrogenase 1a1 mediates a GABA synthesis pathway in midbrain dopaminergic neurons.

PubMed

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

2015-10-02

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 co-release in dopamine neurons does not use 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 (EtOH) at concentrations seen in blood alcohol after binge drinking, 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. Copyright © 2015, American Association for the Advancement of Science.

Evaluation of certain food additives.

PubMed

2015-01-01

This report represents the conclusions of a Joint FAO/WHO Expert Committee convened to evaluate the safety of various food additives, including flavouring agents, and to prepare specifications for identity and purity. The first part of the report contains a general discussion of the principles governing the toxicological evaluation of and assessment of dietary exposure to food additives, including flavouring agents. A summary follows of the Committee's evaluations of technical, toxicological and dietary exposure data for eight food additives (Benzoe tonkinensis; carrageenan; citric and fatty acid esters of glycerol; gardenia yellow; lutein esters from Tagetes erecta; octenyl succinic acid-modified gum arabic; octenyl succinic acid-modified starch; paprika extract; and pectin) and eight groups of flavouring agents (aliphatic and alicyclic hydrocarbons; aliphatic and aromatic ethers; ionones and structurally related substances; miscellaneous nitrogen-containing substances; monocyclic and bicyclic secondary alcohols, ketones and related esters; phenol and phenol derivatives; phenyl-substituted aliphatic alcohols and related aldehydes and esters; and sulfur-containing heterocyclic compounds). Specifications for the following food additives were revised: citric acid; gellan gum; polyoxyethylene (20) sorbitan monostearate; potassium aluminium silicate; and Quillaia extract (Type 2). Annexed to the report are tables summarizing the Committee's recommendations for dietary exposures to and toxicological evaluations of all of the food additives and flavouring agents considered at this meeting.

Clean synthesis of biolubricant range esters using novel liquid lipase enzyme in solvent free medium.

PubMed

Trivedi, Jayati; Aila, Mounika; Sharma, Chandra Dutt; Gupta, Piyush; Kaul, Savita

2015-01-01

In view of the rising global problems of environment pollution and degradation, the present process provides a 'green solution' to the synthesis of higher esters of lubricant range, more specifically in the range C12-C36, using different combinations of acids and alcohols, in a single step reaction. The esters produced are biodegradable in nature and have a plethora of uses, such as in additives, as lubricating oils and other hydraulic fluids. The enzymatic esterification was performed using liquid (non-immobilized or free) lipase enzyme, without any additional organic solvent. Soluble lipase proves to be superior to immobilized enzymes as it is more cost effective and provides a faster process for the production of higher esters of lubricant range. An interesting finding was, that the lipase enzyme showed higher conversion rates with increasing carbon number of straight chain alcohols and acids. Reactions were carried out for the optimization of initial water concentration, temperature, pH of the substrate mixture and the chain length of the substrates. Under optimized conditions, the method was suitable to achieve ~ 99% conversion. Thus, the process provides an environment friendly, enzymatic alternative to the chemical route which is currently used in the industrial synthesis of lubricant components.

Hydrogenation of carbonyl compounds of relevance to hydrogen storage in alcohols

NASA Astrophysics Data System (ADS)

Suárez, Andrés

2018-02-01

Alcohols are a promising source for the sustainable production of hydrogen that may also serve as rechargeable liquid organic hydrogen carriers (LOHCs). Metal-catalyzed acceptorless dehydrogenation of alcohols produces carbonyl derivatives as H2-depleted by-products, which by means of a hydrogenation reaction can be reconverted to the initial alcohols. Hence, reversible H2-storage systems based on pairs of secondary alcohols/ketones and primary alcohols/carboxylic acid derivatives may be envisaged. In this contribution, the hydrogenation of carbonyl derivatives, including ketones, esters, amides and carboxylic acids, is reviewed from the perspective of the hydrogen storage in alcohols.

Alcohol and acetaldehyde in public health: from marvel to menace.

PubMed

Guo, Rui; Ren, Jun

2010-04-01

Alcohol abuse is a serious medical and social problem. Although light to moderate alcohol consumption is beneficial to cardiovascular health, heavy drinking often results in organ damage and social problems. In addition, genetic susceptibility to the effect of alcohol on cancer and coronary heart disease differs across the population. A number of mechanisms including direct the toxicity of ethanol, its metabolites [e.g., acetaldehyde and fatty acid ethyl esters (FAEEs)] and oxidative stress may mediate alcoholic complications. Acetaldehyde, the primary metabolic product of ethanol, is an important candidate toxin in developing alcoholic diseases. Meanwhile, free radicals produced during ethanol metabolism and FAEEs are also important triggers for alcoholic damages.

ELASTIN: DIMINISHED REACTIVITY WITH ALDEHYDE REAGENTS IN COPPER DEFICIENCY AND LATHYRISM

PubMed Central

Miller, E. J.; Fullmer, Harold M.

1966-01-01

Elastin fibers in the aortas of control, lathyritic, copper-supplemented, and copper-deficient chicks were examined histochemically and chemically for aldehyde content. Diminished staining for aldehydes was obtained in the fibers from the aortas of lathyritic and copper-deficient chicks. Chemical studies of elastin isolated from the aortas of control and lathyritic chicks showed an apparent loss of lysine residues in control elastin to be associated with an increase in aldehyde content providing evidence that lysine is converted to an aldehyde-containing intermediate during biosynthesis of desmosine and isodesmosine. Approximately 6 aldehyde groups were present for every 1000 amino acids in elastin isolated from the aortas of control animals, while the corresponding number in lathyritic elastin was 4. At least two types of aldehydes, saturated and α,β-unsaturated, appear to be associated with elastin, suggesting the presence of more than one intermediate between lysine and the desmosines. PMID:5941783

Alcoholism: genes and mechanisms.

PubMed

Oroszi, Gabor; Goldman, David

2004-12-01

Alcoholism is a chronic relapsing/remitting disease that is frequently unrecognized and untreated, in part because of the partial efficacy of treatment. Only approximately one-third of patients remain abstinent and one-third have fully relapsed 1 year after withdrawal from alcohol, with treated patients doing substantially better than untreated [1]. The partial effectiveness of strategies for prevention and treatment, and variation in clinical course and side effects, represent a challenge and an opportunity to better understand the neurobiology of addiction. The strong heritability of alcoholism suggests the existence of inherited functional variants of genes that alter the metabolism of alcohol and variants of other genes that alter the neurobiologies of reward, executive cognitive function, anxiety/dysphoria, and neuronal plasticity. Each of these neurobiologies has been identified as a critical domain in the addictions. Functional alleles that alter alcoholism-related intermediate phenotypes include common alcohol dehydrogenase 1B and aldehyde dehydrogenase 2 variants that cause the aversive flushing reaction; catechol-O-methyltransferase (COMT) Val158Met leading to differences in three aspects of neurobiology: executive cognitive function, stress/anxiety response, and opioid function; opioid receptor micro1 (OPRM1) Asn40Asp, which may serve as a gatekeeper molecule in the action of naltrexone, a drug used in alcoholism treatment; and HTTLPR, which alters serotonin transporter function and appears to affect stress response and anxiety/dysphoria, which are factors relevant to initial vulnerability, the process of addiction, and relapse.

Analysis of 16 phthalic acid esters in food simulants from plastic food contact materials by LC-ESI-MS/MS.

PubMed

Li, Xiaojing; Xiong, Wenming; Lin, Hua; Zhuo, Liyang; Lv, Shuiyuan; Tang, Xi; Chen, Minshi; Zou, Zhexiang; Lin, Zhenyu; Qiu, Bin; Chen, Guonan

2013-02-01

An RP LC-ESI-MS/MS method for the determination of the migration of 16 primary phthalic acid esters from plastic samples has been developed using distilled water, 3% acetic acid, 10% alcohol, and olive oil as food simulants. Detection limits were 1.6-18.5 μg/kg in distilled water, 1.4-17.3 μg/kg in 3% acetic acid, 1.4-19.2 μg/kg in 10% alcohol, and 31.9-390.8 μg/kg in olive oil. The RSDs were in the range of 0.07-11.28%. The real plastic products inspection showed that only few analyzed samples were phthalates contaminated. Bis-2-ethylhexyl ester and dibutyl phthalate were the common items migrated from the plastic products into food and feeds, but the migration concentrations were far below the limits set by European Union (1.5 mg/kg for bis-2-ethylhexyl ester and 0.3 mg/kg for dibutyl phthalate). © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

21 CFR 178.3780 - Polyhydric alcohol esters of long chain monobasic acids.

Code of Federal Regulations, 2014 CFR

2014-04-01

... § 177.1980 of this chapter that contact food of Types I, II, IV-B, VI-B, VII-B, and VIII identified in... produced by the reaction of either ethylene glycol or glycerol with long chain monobasic acids containing... carboxylic acids in the formation of the glycerol esters being neutralized with calcium hydroxide to produce...

Antimicrobial activity of betaine esters, quaternary ammonium amphiphiles which spontaneously hydrolyze into nontoxic components.

PubMed Central

Lindstedt, M; Allenmark, S; Thompson, R A; Edebo, L

1990-01-01

A series of quaternary ammonium compounds that are esters of betaine and fatty alcohols with hydrocarbon chain lengths of 10 to 18 carbon atoms were tested with respect to antimicrobial activities and rates of hydrolysis. When the tetradecyl derivative was tested against some selected microorganisms, the killing effect was comparable to that of the stable quaternary ammonium compound cetyltrimethylammonium bromide. At higher pH values, both the antimicrobial effect and the rate of hydrolysis of the esters increased. However, whereas at pH 6 greater than 99.99% killing of Salmonella typhimurium was achieved with 5 micrograms/ml in 3 min, the rate of hydrolysis was less than 20% in 18 h. At pH 7, a similar killing effect was achieved in 2 min and 50% hydrolysis occurred in ca. 5 h. Thus, it is possible to exploit the rapid microbicidal effect of the compounds before they hydrolyze. The rate of hydrolysis was reduced by the presence of salt. The bactericidal effect of the betaine esters increased with the length of the hydrocarbon chain of the fatty alcohol moiety up to 18 carbon atoms. Since the hydrolysis products are normal human metabolites, the hydrolysis property may extend the use of these quaternary ammonium compounds as disinfectants and antiseptics for food and body surfaces. PMID:2291660

Assessment of chemical and sensory quality of sugarcane alcoholic fermented beverage.

PubMed

Resende Oliveira, Érica; Caliari, Márcio; Soares Soares Júnior, Manoel; Ribeiro Oliveira, Aryane; Cristina Marques Duarte, Renata; Valério de Barros Vilas Boas, Eduardo

2018-01-01

This study aimed to verify the technological feasibility, chemical quality and sensory acceptance of alcoholic fermented beverage obtained from sugarcane juice. A completely randomized design was applied. Sugar and alcohol content, phenolic (HPLC-MS) and volatile (GS-MS) compounds, pH, density, dry matter and acidity of the fermented beverage of sugarcane were quantified, as well as the acceptance of the product was carried out. The complete fermentation of sugarcane lasted 7 days, and it was obtained an alcohol content of 8.0% v/v. Titrable acidity of the beverage was of 67.31 meq L -1 , pH 4.03, soluble solids of 5 °Brix, reducing sugar of 0.07 g glucose 100 g -1 , density of 0.991 g cm -3 , reduced dry matter of 14.15 g L -1 , sulfates lower than 0.7 g K 2 SO 4  L -1 . Various phenolic compounds, among which, gallic acid (10.97%), catechin (1.73%), chlorogenic acid (3.52%), caffeic acid (1.49%), vanillic acid (0.28%), p -coumaric acid (0.24%), ferulic acid (6.63%), m -coumaric acid (0.36%), and o -coumaric acid (0.04%). Amongst aromatic compounds, were found mainly esters with fruity aromas (ethyl ester hexanoic acid and ethyl ester octanoic acid). The sugarcane juice can be commercialized as an alternative wine, as it presented adequate features to an alcoholic fermented beverage and was sensory accepted by consumers.

A Pauson-Khand-type reaction between alkynes and olefinic aldehydes catalyzed by rhodium/cobalt heterobimetallic nanoparticles: an olefinic aldehyde as an olefin and CO source.

PubMed

Park, Kang Hyun; Jung, Il Gu; Chung, Young Keun

2004-04-01

Co/Rh (Co:Rh = 2:2) heterobimetallic nanoparticles derived from Co(2)Rh(2)(CO)(12) react with alkynes and alpha,beta-unsaturated aldehydes such as acrolein, crotonaldehyde, and cinnamic aldehyde and release products resulting from [2 + 2 + 1]cycloaddition of alkyne, carbon monoxide, and alkene. alpha,beta-Unsaturated aldehydes act as a CO and alkene source. These reactions produce 2-substituted cyclopentenones.

Rotational Investigation of the Adducts of Formic Acid with Alcohols, Ethers and Esters

NASA Astrophysics Data System (ADS)

Evangelisti, Luca; Spada, Lorenzo; Li, Weixing; Caminati, Walther

2016-06-01

Mixtures of formic acid with methyl alcohol, with isopropyl alcohol, with tert-butyl alcohol, with dimethylether and with isopropylformiate have been supersonically expanded as pulsed jets. The obtained cool plumes have been analyzed by Fourier transform microwave spectroscopy. It has been possible to assign the rotational spectra of the 1:1 adducts of formic acid with tert-butyl alcohol, with dimethyl ether and with isopropylformiate. The conformational shapes and geometries of these adducts, as well as the topologies of their itermolecular hydrogen bonds will be presented. An explanation is given of the failure of the assignments of the rotational spectra of the adducts of formic acid with methyl alcohol and isopropyl alcohol.

Deletion of GSTA4-4 results in increased mitochondrial post-translational modification of proteins by reactive aldehydes following chronic ethanol consumption in mice

PubMed Central

Shearn, Colin T.; Fritz, Kristofer S.; Shearn, Alisabeth H.; Saba, Laura M.; Mercer, Kelly E.; Engi, Bridgette; Galligan, James J.; Zimniak, Piotr; Orlicky, David J.; Ronis, Martin J.; Petersen, Dennis R.

2015-01-01

Chronic alcohol consumption induces hepatic oxidative stress resulting in production of highly reactive electrophilic α/β-unsaturated aldehydes that have the potential to modify proteins. A primary mechanism of reactive aldehyde detoxification by hepatocytes is through GSTA4-driven enzymatic conjugation with GSH. Given reports that oxidative stress initiates GSTA4 translocation to the mitochondria, we hypothesized that increased hepatocellular damage in ethanol (EtOH)-fed GSTA4−/− mice is due to enhanced mitochondrial protein modification by reactive aldehydes. Chronic ingestion of EtOH increased hepatic protein carbonylation in GSTA4−/− mice as evidenced by increased 4-HNE and MDA immunostaining in the hepatic periportal region. Using mass spectrometric analysis of biotin hydrazide conjugated carbonylated proteins, a total of 829 proteins were identified in microsomal, cytosolic and mitochondrial fractions. Of these, 417 were novel to EtOH models. Focusing on mitochondrial fractions, 1.61-fold more carbonylated proteins were identified in EtOH-fed GSTA4−/− mice compared to their respective WT mice ingesting EtOH. Bioinformatic KEGG pathway analysis of carbonylated proteins from the mitochondrial fractions revealed an increased propensity for modification of proteins regulating oxidative phosphorylation, glucose, fatty acid, glutathione and amino acid metabolic processes in GSTA4−/− mice. Additional analysis revealed sites of reactive aldehyde protein modification on 26 novel peptides/proteins isolated from either SV/GSTA4−/− PF or EtOH fed mice. Among the peptides/proteins identified, ACSL, ACOX2, MTP, and THIKB contribute to regulation of fatty acid metabolism and ARG1, ARLY, and OAT, which regulate nitrogen and ammonia metabolism having direct relevance to ethanol-induced liver injury. These data define a role for GSTA4-4 in buffering hepatic oxidative stress associated with chronic alcohol consumption and that this GST isoform plays an

An anionic rhodium eta4-quinonoid complex as a multifunctional catalyst for the arylation of aldehydes with arylboronic acids.

PubMed

Son, Seung Uk; Kim, Sang Bok; Reingold, Jeffrey A; Carpenter, Gene B; Sweigart, Dwight A

2005-09-07

The pi-bonded rhodium quinonoid complex, K+[(1,4-benzoquinone)Rh(COD)]-, functions as a good catalyst for the coupling of arylboronic acid and aldehydes to afford diaryl alcohols. The catalysis is heterobimetallic in that both the transition metal and concomitant alkali metal counterion play an integral part in the reaction. In addition, the anionic quinonoid catalyst itself plays a bifunctional role by acting as a ligand to the boronic acid and as a Lewis acid receptor site for the transferring aryl group.

Concerning the mechanism of the FeCl3-catalyzed alpha-oxyamination of aldehydes: evidence for a non-SOMO activation pathway.

PubMed

Van Humbeck, Jeffrey F; Simonovich, Scott P; Knowles, Robert R; MacMillan, David W C

2010-07-28

The mechanism of a recently reported aldehyde alpha-oxyamination reaction has been studied using a combination of kinetic, spectrometric, and spectrophotometric techniques. Most crucially, the use of a validated cyclopropane-based radical-clock substrate has demonstrated that carbon-oxygen bond formation occurs predominantly through an enamine activation manifold. The mechanistic details reported herein indicate that, as has been proposed for previously studied alcohol oxidations, complexation between TEMPO and a simple metal salt leads to electrophilic ionic reactivity.

Schiff and pseudo-Schiff reagents: the reactions and reagents of Hugo Schiff, including a classification of various kinds of histochemical reagents used to detect aldehydes.

PubMed

Dapson, R W

2016-11-01

During the 1860's, Hugo Schiff studied many reactions between amines and aldehydes, some of which have been used in histochemistry, at times without credit to Schiff. Much controversy has surrounded the chemical structures and reaction mechanisms of the compounds involved, but modern analytical techniques have clarified the picture. I review these reactions here. I used molecular modeling software to investigate dyes that contain primary amines representing eight chemical families. All dyes were known to perform satisfactorily for detecting aldehydes in tissue sections. The models verified the correct chemical structures at various points in their reactions and also determined how decolorization occurred in those with "leuco" forms. Decolorization in the presence of sulfurous acid can occur by either adduction or reduction depending on the dye. The final condensation product with aldehyde was determined to be either a C-sulfonic acid adduct on the carbonyl carbon atom or an aminal at the same atom. Based on the various outcomes, I have placed the dyes and their reactions into five categories. Because Hugo Schiff studied the reactions between aldehydes and amines with and without various acids or alcohol, it is only proper to call each of them Schiff reactions that used various types of Schiff reagents.

Volatile organic chemicals of a shore-dwelling cyanobacterial mat community.

PubMed

Evans, W G

1994-02-01

The main components of a cyanobacterial mat community of a hypersaline lake shore consist of edaphic, mat-forming strains (ecophenes), and littoral strains ofOscillatoria animalis Agardh andO. subbrevis Schmidle, other microorganisms associated with these cyanobacteria, several species ofBembidion (Carabidae: Coleoptera), and two halophytic flowering plants:Puccinellia nuttalliana (salt meadow grass) andSalicornia europaea rubra (samphire). The volatile organic compounds of this community are a blend of those emitted by each of these components such as the C17 alka(e)nes, geosmin, 2-methylisoborneol,β-cyclocitral,β-ionone, dimethyl sulfide, and dimethyl trisulfide of cyanobacteria and associated microorganisms; alcohols, esters, and aldehydes usually associated with flowering plants; and possibly some insect-derived esters, particularly isopropyl tetradecanoate. The dominant compounds were: C11, C13, C15, and C17 alka(e)nes, methyl esters of C16 and C18:2 acids, isopropyl tetradecanoate, heptanal, 3-octanone and 2-nonanone, the acyclic terpene linalool, and the alcohols 1-heptanol, 1-hexanol, 1-octanol, 3-hexen-1-ol, and 2-octen-1-ol. It is concluded that this community may be distinguished from related communities by its repertoire of volatile organic compounds.

Research on alcohol metabolism among Asians and its implications for understanding causes of alcoholism.

PubMed Central

Suddendorf, R F

1989-01-01

Research into the causes of alcoholism is a relatively recent scientific endeavor. One area of study which could lead to better understanding of the disease is the possibility of a genetic predisposition to alcoholism. Recent work has demonstrated that people have varying complements of enzymes to metabolize alcohol. Current knowledge is examined about the influence of various ethanol metabolizing enzymes on alcohol consumption by Asians and members of other ethnic groups. The two principal enzymes involved in ethanol oxidative metabolism are alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH). ADH is responsible for the metabolism of ethanol to acetaldehyde. ALDH catalyzes the conversion of acetaldehyde to acetate. The different isozymes account for the diversity of alcohol metabolism among individuals. An isozyme of ADH (beta 2 beta 2) is found more frequently in Asians than in whites, and an ALDH isozyme (ALDH2), although present in Asians, often is in an inactive form. The presence of an inactive form of ALDH2 is thought to be responsible for an increase in acetaldehyde levels in the body. Acetaldehyde is considered responsible for the facial flushing reaction often observed among Asians who have consumed alcohol. A dysphoric reaction to alcohol, producing uncomfortable sensations, is believed to be a response to deter further consumption. Although the presence of an inactive ALDH2 isozyme may serve as a deterrent to alcohol consumption, its presence does not fully explain the levels of alcohol consumption by those with the inactive isozyme. Other conditions, such as social pressure, and yet undetermined biological factors, may play a significant role in alcohol consumption. PMID:2511595

Substitutions of S101 decrease proton and hydride transfers in the oxidation of betaine aldehyde by choline oxidase.

PubMed

Gadda, Giovanni; Yuan, Hongling

2017-11-15

Choline oxidase oxidizes choline to glycine betaine, with two flavin-mediated reactions to convert the alcohol substrate to the carbon acid product. Proton abstraction from choline or hydrated betaine aldehyde in the wild-type enzyme occurs in the mixing time of the stopped-flow spectrophotometer, thereby precluding a mechanistic investigation. Mutagenesis of S101 rendered the proton transfer reaction amenable to study. Here, we have investigated the aldehyde oxidation reaction catalyzed by the mutant enzymes using steady-state and rapid kinetics with betaine aldehyde. Stopped-flow traces for the reductive half-reaction of the S101T/V/C variants were biphasic, corresponding to the reactions of proton abstraction and hydride transfer. In contrast, the S101A enzyme yielded monophasic traces like wild-type choline oxidase. The rate constants for proton transfer in the S101T/C/V variants decreased logarithmically with increasing hydrophobicity of residue 101, indicating a behavior different from that seen previously with choline for which no correlation was determined. The rate constants for hydride transfer also showed a logarithmic decrease with increasing hydrophobicity at position 101, which was similar to previous results with choline as a substrate for the enzyme. Thus, the hydrophilic character of S101 is necessary not only for efficient hydride transfer but also for the proton abstraction reaction. Copyright © 2017. Published by Elsevier Inc.

Polyvinyl alcohol membranes as alkaline battery separators

NASA Technical Reports Server (NTRS)

Sheibley, D. W.; Gonzalez-Sanabria, O.; Manzo, M. A.

1982-01-01

Polyvinly alcohol (PVA) cross-linked with aldehyde reagents yields membranes that demonstrate properties that make them suitable for use as alkaline battery separators. Film properties can be controlled by the choice of cross-linker, cross-link density and the method of cross-linking. Three methods of cross-linking and their effects on film properties are discussed. Film properties can also be modified by using a copolymer of vinyl alcohol and acrylic acid as the base for the separator and cross-linking it similarly to the PVA. Fillers can be incorporated into the films to further modify film properties. Results of separator screening tests and cell tests for several variations of PBA films are discussed.

Saccharomyces cerevisiae Atf1p is an alcohol acetyltransferase and a thioesterase in vitro.

PubMed

Nancolas, Bethany; Bull, Ian D; Stenner, Richard; Dufour, Virginie; Curnow, Paul

2017-06-01

The alcohol-O-acyltransferases are bisubstrate enzymes that catalyse the transfer of acyl chains from an acyl-coenzyme A (CoA) donor to an acceptor alcohol. In the industrial yeast Saccharomyces cerevisiae this reaction produces acyl esters that are an important influence on the flavour of fermented beverages and foods. There is also a growing interest in using acyltransferases to produce bulk quantities of acyl esters in engineered microbial cell factories. However, the structure and function of the alcohol-O-acyltransferases remain only partly understood. Here, we recombinantly express, purify and characterize Atf1p, the major alcohol acetyltransferase from S. cerevisiae. We find that Atf1p is promiscuous with regard to the alcohol cosubstrate but that the acyltransfer activity is specific for acetyl-CoA. Additionally, we find that Atf1p is an efficient thioesterase in vitro with specificity towards medium-chain-length acyl-CoAs. Unexpectedly, we also find that mutating the supposed catalytic histidine (H191) within the conserved HXXXDG active site motif only moderately reduces the thioesterase activity of Atf1p. Our results imply a role for Atf1p in CoA homeostasis and suggest that engineering Atf1p to reduce the thioesterase activity could improve product yields of acetate esters from cellular factories. © 2017 The Authors. Yeast published by John Wiley & Sons, Ltd. © 2017 The Authors. Yeast published by John Wiley & Sons, Ltd.

Volatile composition of coffee berries at different stages of ripeness and their possible attraction to the coffee berry borer Hypothenemus hampei (Coleoptera: Curculionidae).

PubMed

Ortiz, Américo; Ortiz, Aristófeles; Vega, Fernando E; Posada, Francisco

2004-09-22

The analysis of volatile emissions of coffee berries in different physiological states of ripeness was performed using dynamic headspace and gas chromatography/mass spectrometry analysis for Coffea arabica, var. Colombia. The composition of the volatiles emitted by coffee berries is dominated by very high levels of alcohols, mainly ethanol, in all stages of ripeness in comparison with other compounds. Overripe coffee berries have high volatile emissions and show a composition dominated mainly by esters followed by alcohols, ketones, and aldehydes. The lowest level compounds were monoterpenes. 2-Methyl furan was detected in various ripening stages; this compound has not been previously reported as a coffee berry volatile. The presence of ethanol and other alcohols in the volatile composition might explain the effectiveness of using traps with mixed alcohols for detection and capture of coffee berry borers.

One-Pot Catalytic Enantio- and Diastereoselective Syntheses of anti-, syn-cis-Disubstituted, and syn-Vinyl Cyclopropyl Alcohols

PubMed Central

Kim, Hun Young; Salvi, Luca; Carroll, Patrick J.; Walsh, Patrick J.

2009-01-01

Highly enantio- and diastereoselective methods for the synthesis of a variety of cyclopropyl alcohols are reported. These methods represent the first one-pot approaches to syn-vinyl cyclopropyl alcohols, syn-cis-disubstituted cyclopropyl alcohols, and anti-cyclopropyl alcohols from achiral precursors. The methods begin with enantioselective C–C bond formations promoted by a MIB-based zinc catalyst to generate allylic alkoxide intermediates. The intermediates are then subjected to in situ alkoxide-directed cyclopropanation to provide cyclopropyl alcohols. In the synthesis of vinyl cyclopropyl alcohols, hydroboration of enynes is followed by transmetalation of the resulting dienylborane to zinc to provide dienylzinc reagents. Enantioselective addition to aldehydes generates the requisite dienyl zinc alkoxides, which are then subjected to in situ cyclopropanation to furnish vinyl cyclopropyl alcohols. Cyclopropanation occurs at the double bond allylic to the alkoxide. Using this method, syn-vinylcyclopropyl alcohols are obtained in 65–85% yield, 76–93% ee, and >19:1 dr. To prepare anti-cyclopropanols, enantioselective addition of alkylzinc reagents to conjugated enals provides allylic zinc alkoxides. Because direct cyclopropanation provides syn-cyclopropyl alcohols, the intermediate allylic alkoxides were treated with TMSCl/Et3N to generate intermediate silyl ethers. In situ cyclopropanation of the allylic silyl ether resulted in cyclopropanation to form the anti-cyclopropyl silyl ether. Workup with TBAF affords the anti-cyclopropyl alcohols in one-pot in 60–82% yield, 89–99% ee, and ≥10:1 dr. For the synthesis of cis-disubstituted cyclopropyl alcohols, in situ generated (Z)-vinyl zinc reagents were employed in asymmetric addition to aldehydes to generate (Z)-allylic zinc alkoxides. In situ cyclopropanation provides syn-cis-disubstituted cyclopropyl alcohols in 42–70% yield, 88–97% ee, and >19:1 dr. These one-pot procedures enable the synthesis of a

Genetic polymorphisms of ADH1B, ADH1C and ALDH2 in Turkish alcoholics: lack of association with alcoholism and alcoholic cirrhosis.

PubMed

Vatansever, Sezgin; Tekin, Fatih; Salman, Esin; Altintoprak, Ender; Coskunol, Hakan; Akarca, Ulus Salih

2015-05-17

No data exists regarding the alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) gene polymorphisms in Turkish alcoholic cirrhotics. We studied the polymorphisms of ADH1B, ADH1C and ALDH2 genes in alcoholic cirrhotics and compared the results with non-cirrhotic alcoholics and healthy volunteers. Overall, 237 subjects were included for the study: 156 alcoholic patients (78 cirrhotics, 78 non-cirrhotic alcoholics) and 81 healthy volunteers. Three different single-nucleotide-polymorphism genotyping methods were used. ADH1C genotyping was performed using a polymerase chain reaction-restriction fragment length polymorphism method. The identified ADH1C genotypes were named according to the presence or absence of the enzyme restriction sites. ADH1B (Arg47Hys) genotyping was performed using the allele specific primer extension method, and ALDH2 (Glu487Lys) genotyping was performed by a multiplex polymerase chain reaction using two allele-specific primer pairs. For ADH1B, the frequency of allele *1 in the cirrhotics, non-cirrhotic alcoholics and healthy volunteers was 97.4%, 94.9% and 99.4%, respectively. For ADH1C, the frequency of allele *1 in the cirrhotics, non-cirrhotic alcoholics and healthy volunteers was 47%, 36.3% and 45%, respectively. There was no statistical difference between the groups for ADH1B and ADH1C (p>0.05). All alcoholic and non-alcoholic subjects (100%) had the allele *1 for ALDH2. The obtained results for ADH1B, ADH1C, and ALDH gene polymorphisms in the present study are similar to the results of Caucasian studies. ADH1B and ADH1C genetic variations are not related to the development of alcoholism or susceptibility to alcoholic cirrhosis. ALDH2 gene has no genetic variation in the Turkish population.

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. © 2016 Authors; published by Portland Press Limited.

Selective Oxidation of Alcohols Using Photoactive VO@g??C3N4

EPA Pesticide Factsheets

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.This dataset is associated with the following publication:Verma, S., R.B. Nasir Baig, M. Nadagouda , and R. Varma. Selective oxidation of alcohols using photoactive VO@g-C3N4.. ACS Sustainable Chemistry & Engineering. American Chemical Society, Washington, DC, USA, 4(3): 1094-1098, (2015).

Fatty acid ethyl ester concentrations in hair and self-reported alcohol consumption in 644 cases from different origin.

PubMed

Süsse, Silke; Selavka, Carl M; Mieczkowski, Tom; Pragst, Fritz

2010-03-20

For diagnosis of chronic alcohol abuse, fatty acid ethyl esters (FAEE) were determined in hair samples from 644 individuals, mainly parents from child protection cases. The analysis for ethyl myristate, ethyl palmitate, ethyl oleate and ethyl stearate was performed according to a validated procedure consisting of external degreasing by two times washing with n-heptane, extraction with a mixture of dimethylsulfoxide and n-heptane, separation and evaporation of the n-heptane layer, headspace solid phase microextraction of the residue after addition of phosphate buffer pH 7.6 and gas chromatography-mass spectrometry using deuterated internal standards. For interpretation, the sum of the concentrations of the four esters C(FAEE) was used with the cut-off's 0.5 ng/mg for the proximal scalp hair segment 0-3 cm or less and 1.0 ng/mg for scalp hair samples with a length between 3 and 6 cm and for body hair. C(FAEE) ranged from 0.11 to 31 ng/mg (mean 1.77 ng/mg, median 0.82 ng/mg). The mean concentration ratio between the 4 esters was 8:45:38:9. 298 cases had C(FAEE) above the cut-off's. Self-reported drinking data were obtained in 553 of the cases in the categories abstinent (156 cases), moderate drinking (252 cases) and excessive drinking (145 cases). Median and box-plot data clearly demonstrate differentiation of these ingestor sub-populations by C(FAEE). However, in the abstinent and moderate groups the consumption was frequently underreported (37 and 110 cases positive) whereas in the group self-reported excessive drinking 32 cases were negative. Comparison of C(FAEE) with carbohydrate-deficient transferrin (CDT) in 139 cases and gamma-glutamyltransferase (GGT) in 136 cases showed a good agreement in CDT- and GGT positive cases (27/28 and 32/41) but a large portion of the negative CDT- and GGT-results with positive hair test (44/100 and 48/95) which is explained mainly by the much shorter time window of CDT and GGT. No significant correlation was found between persons

Certain tricyclic and pentacyclic-hetero nitrogen rhodol dyes

DOEpatents

Haugland, Richard P.; Whitaker, James E.

1993-01-01

Novel fluorescent dyes based on the rhodol structure are provided. The new reagents contain functional groups capable of forming a stable fluorescent product with functional groups typically found in biomolecules or polymers including amines, phenols, thiols, acids, aldehydes and ketones. Reactive groups in the rhodol dyes include activated esters, isothiocyanates, amines, hydrazines, halides, acids, azides, maleimides, aldehydes, alcohols, acrylamides and haloacetamides. The products are detected by their absorbance or fluorescence properties. The spectral properties of the fluorescent dyes are sufficiently similar in wavelengths and intensity to fluorescein or rhodamine derivatives as to permit use of the same equipment. The dyes, however, show less spectral sensitivity to pH in the physiological range than does fluorescein, have higher solubility in non-polar solvents and have improved photostability and quantum yields.

Liquid Crystalline Thermosets from Ester, Ester-imide, and Ester-amide Oligomers

NASA Technical Reports Server (NTRS)

Dingemans, Theodorus J. (Inventor); Weiser, Erik S. (Inventor); St. Clair, Terry L. (Inventor)

2009-01-01

Main chain thermotropic liquid crystal esters, ester-imides, and ester-amides were prepared from AA, BB, and AB type monomeric materials and end-capped with phenylacetylene, phenylmaleimide, or nadimide reactive end-groups. The end-capped liquid crystal oligomers are thermotropic and have, preferably, molecular weights in the range of approximately 1000-15,000 grams per mole. The end-capped liquid crystaloligomers have broad liquid crystalline melting ranges and exhibit high melt stability and very low melt viscosities at accessible temperatures. The end-capped liquid crystal oli-gomers are stable forup to an hour in the melt phase. They are highly processable by a variety of melt process shape forming and blending techniques. Once processed and shaped, the end-capped liquid crystal oigomers were heated to further polymerize and form liquid crystalline thermosets (LCT). The fully cured products are rubbers above their glass transition temperatures.

Tandem cyclopropanation with dibromomethane under Grignard conditions.

PubMed

Brunner, Gerhard; Eberhard, Laura; Oetiker, Jürg; Schröder, Fridtjof

2008-10-03

Tertiary Grignard reagents and dibromomethane efficiently cyclopropanate allylic (and certain homoallylic) magnesium and lithium alcoholates at ambient temperature in ether solvents. Lithium (homo)allyl alcoholates are directly cyclopropanated with magnesium and CH2Br2 under Barbier conditions at higher temperatures. The reaction rates depend on the substitution pattern of the (homo)allylic alcoholates and on the counterion with lithium giving best results. Good to excellent syn-selectivities are obtained from alpha-substituted substrates, which are in accord with a staggered Houk model. In tandem reactions, cyclopropyl carbinols are obtained from allyloxylithium or -magnesium intermediates, generated in situ by alkylation of conjugated aldehydes, ketones, and esters as well as from allyl carboxylates or vinyloxiranes. Using this methodology, numerous fragrance ingredients and their precursors were efficiently converted to the corresponding cyclopropyl carbinols.

Effect of pentachlorophenol and 2,6-dichloro-4-nitrophenol on the activity of cDNA-expressed human alcohol and aldehyde dehydrogenases.

PubMed

Kollock, Ronny; Rost, Katharina; Batke, Monika; Glatt, Hansruedi

2009-12-15

Pentachlorophenol (PCP) and 2,6-dichloro-4-nitrophenol (DCNP), potent inhibitors of phenol sulphotransferases, are frequently used in animal studies to elucidate the role of these enzymes in the biotransformation and toxicity of xenobiotics. An unexpected finding with 1-hydroxymethylpyrene--a strong decrease in the excretion of the corresponding carboxylic acid in rats concurrently treated with PCP-led us to suspect that this sulphotransferase inhibitor may also affect alcohol dehydrogenases (ADHs) and/or aldehyde dehydrogenases (ALDHs). Subsequently we investigated the influence of PCP and DCNP on the activity of cDNA-expressed human ADHs and ALDHs. PCP inhibited all four ADHs studied. The inhibition was strong for ADH3 (K(i) 1.4 microM, K(i)' 5.2 microM, mixed-type) and ADH2 (K(i) 3.7 microM, competitive), but moderate for ADH4 (K(i) 81 microM, competitive) and ADH1C (K(i)' 310 microM, uncompetitive). Activities of ALDH2 and ALDH3A1 were unaffected by PCP (used up to a concentration of 1 mM). In contrast, DCNP primarily inhibited ALDH2 (K(i)=K(i)' 7.4 microM, non-competitive), showed moderate competitive inhibition of ADH2 (K(i) 160 microM) and ADH4 (K(i) 710 microM), but did not affect the remaining enzymes (ADH1C, ADH3 and ALDH3A1). The study demonstrates that caution is required when using putative specific enzyme inhibitors in biotransformation studies.

Determination of fatty acid ethyl esters (FAEE) and ethyl glucuronide (EtG) in hair: a promising way for retrospective detection of alcohol abuse during pregnancy?

PubMed

Pragst, Fritz; Yegles, Michel

2008-04-01

The retrospective detection of alcohol consumption during pregnancy is an important part of the diagnosis of the fetal alcohol syndrome. A promising way to solve this problem can be the determination of fatty acid ethyl esters (FAEE) or/and ethyl glucuronide (EtG) in hair of the mothers. In this article, the present state in analytical determination and interpretation of FAEE and EtG concentrations in hair are reviewed. Both FAEE and EtG are minor metabolites of ethanol and as direct alcohol markers very specific for alcohol. They are durably deposited in hair, which enables taking advantage of the long diagnostic time window of this sample material. In the last years, specific and sensitive methods for determination of both alcohol markers in hair were developed. Headspace solid phase microextraction in combination with gas chromatography-mass spectroscopy after hair extraction with an n-heptane/dimethylsulfoxide mixture proved to be a favorable technique for determination of four characteristic FAEE (ethyl myristate, ethyl palmitate, ethyl oleate, and ethyl stearate). EtG is extracted from hair by water and analyzed either by gas chromatography-mass spectroscopy with negative chemical ionization after cleanup with solid phase extraction and derivatization with pentafluoropropionic anhydride or by liquid chromatography-mass spectroscopy-mass spectroscopy. The detection limits of the single FAEE as well as of EtG are in the range of 1 to 10 pg/mg. FAEE as well as EtG were determined in a larger number of hair samples of teetotalers, social drinkers, patients in alcohol withdrawal treatment, and death cases with previous known heavy drinking. From the results, the following criteria were derived: strict abstinence is excluded or improbable at C FAEE >0.2 ng/mg or C EtG >7 pg/mg. Moderate social drinkers should have C FAEE <0.5 ng/mg and C EtG <25 pg/mg; above these values, alcohol abuse is probable. Until now, there has been no evaluation in context of FAS diagnosis

Direct, enantioselective α-alkylation of aldehydes using simple olefins.

PubMed

Capacci, Andrew G; Malinowski, Justin T; McAlpine, Neil J; Kuhne, Jerome; MacMillan, David W C

2017-11-01

Although the α-alkylation of ketones has already been established, the analogous reaction using aldehyde substrates has proven surprisingly elusive. Despite the structural similarities between the two classes of compounds, the sensitivity and unique reactivity of the aldehyde functionality has typically required activated substrates or specialized additives. Here, we show that the synergistic merger of three catalytic processes-photoredox, enamine and hydrogen-atom transfer (HAT) catalysis-enables an enantioselective α-aldehyde alkylation reaction that employs simple olefins as coupling partners. Chiral imidazolidinones or prolinols, in combination with a thiophenol, iridium photoredox catalyst and visible light, have been successfully used in a triple catalytic process that is temporally sequenced to deliver a new hydrogen and electron-borrowing mechanism. This multicatalytic process enables both intra- and intermolecular aldehyde α-methylene coupling with olefins to construct both cyclic and acyclic products, respectively. With respect to atom and step-economy ideals, this stereoselective process allows the production of high-value molecules from feedstock chemicals in one step while consuming only photons.

Direct, enantioselective α-alkylation of aldehydes using simple olefins

NASA Astrophysics Data System (ADS)

Capacci, Andrew G.; Malinowski, Justin T.; McAlpine, Neil J.; Kuhne, Jerome; MacMillan, David W. C.

2017-11-01

Although the α-alkylation of ketones has already been established, the analogous reaction using aldehyde substrates has proven surprisingly elusive. Despite the structural similarities between the two classes of compounds, the sensitivity and unique reactivity of the aldehyde functionality has typically required activated substrates or specialized additives. Here, we show that the synergistic merger of three catalytic processes—photoredox, enamine and hydrogen-atom transfer (HAT) catalysis—enables an enantioselective α-aldehyde alkylation reaction that employs simple olefins as coupling partners. Chiral imidazolidinones or prolinols, in combination with a thiophenol, iridium photoredox catalyst and visible light, have been successfully used in a triple catalytic process that is temporally sequenced to deliver a new hydrogen and electron-borrowing mechanism. This multicatalytic process enables both intra- and intermolecular aldehyde α-methylene coupling with olefins to construct both cyclic and acyclic products, respectively. With respect to atom and step-economy ideals, this stereoselective process allows the production of high-value molecules from feedstock chemicals in one step while consuming only photons.

Aldehyde dehydrogenase 3A1 activation prevents radiation-induced xerostomia by protecting salivary stem cells from toxic aldehydes

PubMed Central

Saiki, Julie P.; Cao, Hongbin; Van Wassenhove, Lauren D.; Viswanathan, Vignesh; Bloomstein, Joshua; Nambiar, Dhanya K.; Mattingly, Aaron J.; Jiang, Dadi; Chen, Che-Hong; Simmons, Amanda L.; Park, Hyun Shin; von Eyben, Rie; Kool, Eric T.; Sirjani, Davud; Knox, Sarah M.; Le, Quynh Thu; Mochly-Rosen, Daria

2018-01-01

Xerostomia (dry mouth) is the most common side effect of radiation therapy in patients with head and neck cancer and causes difficulty speaking and swallowing. Since aldehyde dehydrogenase 3A1 (ALDH3A1) is highly expressed in mouse salivary stem/progenitor cells (SSPCs), we sought to determine the role of ALDH3A1 in SSPCs using genetic loss-of-function and pharmacologic gain-of-function studies. Using DarkZone dye to measure intracellular aldehydes, we observed higher aldehyde accumulation in irradiated Aldh3a1−/− adult murine salisphere cells and in situ in whole murine embryonic salivary glands enriched in SSPCs compared with wild-type glands. To identify a safe ALDH3A1 activator for potential clinical testing, we screened a traditional Chinese medicine library and isolated d-limonene, commonly used as a food-flavoring agent, as a single constituent activator. ALDH3A1 activation by d-limonene significantly reduced aldehyde accumulation in SSPCs and whole embryonic glands, increased sphere-forming ability, decreased apoptosis, and improved submandibular gland structure and function in vivo after radiation. A phase 0 study in patients with salivary gland tumors showed effective delivery of d-limonene into human salivary glands following daily oral dosing. Given its safety and bioavailability, d-limonene may be a good clinical candidate for mitigating xerostomia in patients with head and neck cancer receiving radiation therapy. PMID:29794221

Determination of Volatiles by Odor Activity Value and Phenolics of cv. Ayvalik Early-Harvest Olive Oil

PubMed Central

Guclu, Gamze; Sevindik, Onur; Kelebek, Hasim; Selli, Serkan

2016-01-01

Ayvalik is an important olive cultivar producing high quality oils in Turkey. In the present study, volatile and phenolic compositions of early-harvest extra virgin olive oil (cv. Ayvalik) were determined. The solvent-assisted flavor evaporation (SAFE) technique was used for the extraction of volatile components. The aromatic extract obtained by SAFE was representative of the olive oil odor. A total of 32 aroma compounds, including alcohols, aldehydes, terpenes, esters, and an acid, were identified in the olive oil. Aldehydes and alcohols were qualitatively and quantitatively the most dominant volatiles in the oil sample. Of these, six volatile components presented odor activity values (OAVs) greater than one, with (Z)-3-hexenal (green), hexanal (green-sweet) and nonanal (fatty-pungent) being those with the highest OAVs in olive oil. A total of 14 phenolic compounds were identified and quantified by liquid chromatography combined with a diode array detector and ion spray mass spectrometry. The major phenolic compounds were found as 3,4-DHPEA-EDA, 3,4-DHPEA-EA and p-HPEA-EDA. PMID:28231141

Simple one-pot conversion of aldehydes and ketones to enals.

PubMed

Valenta, Petr; Drucker, Natalie A; Bode, Jeffrey W; Walsh, Patrick J

2009-05-21

A simple and efficient method to convert aldehydes into alpha,beta-unsaturated aldehydes with a two-carbon homologation is presented. Hydroboration of ethoxy acetylene with BH(3).SMe(2) generates tris(ethoxyvinyl) borane. Transmetalation with diethylzinc, addition to aldehydes or ketones, and acidic workup affords enals. When the addition is quenched with anilinium hydrochloride, 1,2-dithioglycol, or acetic anhydride, the unsaturated imine, dithiolane, or 1,1-diacetate is isolated in high yield. These transformations can be performed in a one-pot procedure.

Spectral and catalytic properties of aryl-alcohol oxidase, a fungal flavoenzyme acting on polyunsaturated alcohols

PubMed Central

2005-01-01

Spectral and catalytic properties of the flavoenzyme AAO (aryl-alcohol oxidase) from Pleurotus eryngii were investigated using recombinant enzyme. Unlike most flavoprotein oxidases, AAO does not thermodynamically stabilize a flavin semiquinone radical and forms no sulphite adduct. AAO catalyses the oxidative dehydrogenation of a wide range of unsaturated primary alcohols with hydrogen peroxide production. This differentiates the enzyme from VAO (vanillyl-alcohol oxidase), which is specific for phenolic compounds. Moreover, AAO is optimally active in the pH range of 5–6, whereas VAO has an optimum at pH 10. Kinetic studies showed that AAO is most active with p-anisyl alcohol and 2,4-hexadien-1-ol. AAO converts m- and p-chlorinated benzyl alcohols at a similar rate as it does benzyl alcohol, but introduction of a p-methoxy substituent in benzyl alcohol increases the reaction rate approx. 5-fold. AAO also exhibits low activity on aromatic aldehydes. 19F NMR analysis showed that fluorinated benzaldehydes are converted into the corresponding benzoic acids. Inhibition studies revealed that the AAO active site can bind a wide range of aromatic ligands, chavicol (4-allylphenol) and p-anisic (4-methoxybenzoic) acid being the best competitive inhibitors. Uncompetitive inhibition was observed with 4-methoxybenzylamine. The properties described above render AAO a unique oxidase. The possible mechanism of AAO binding and oxidation of substrates is discussed in the light of the results of the inhibition and kinetic studies. PMID:15813702