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Results 251 - 300 of 1894
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Lee J W - - 2008
Fatty acid methyl ester (FAME) technology was evaluated as a monitoring tool for quantification of Gordonia amarae in activated sludge systems. The fatty acid, 19:1 alcohol, which was identified as a unique fatty acid in G. amarae was not only confirmed to be present in foaming plant samples, but the ...
Li Xin - - 2008
Flaxseed contains the largest amount of lignan secoisolariciresinol diglucoside (SDG) oligomers and is the richest dietary source of SDG. SDG oligomers in the flaxseed extract are often hydrolyzed to break the ester linkages for the release of SDG and the glycosidic bonds for the release of secoisolariciresinol (SECO). The hydrolysates ...
Crugeiras Juan J Departamento de Química Física, Facultad de Química, Universidad de Santiago, 15782 Santiago de Compostela, - - 2008
Equilibrium constants in D2O were determined by 1H NMR analyses for formation of imines/iminium ions from addition of glycine methyl ester to acetone and from addition of glycine to phenylglyoxylate. First-order rate constants, also determined by 1H NMR, are reported for deuterium exchange between solvent D2O and the alpha-amino carbon ...
Koo Yeon Jong - - 2008
We developed a quantitative method for the determination of methyl esterase activity, analyzing substrate specificity against three major signal molecules, jasmonic acid methyl ester (MeJA), salicylic acid methyl ester (MeSA), and indole-3-acetic acid methyl ester (MeIAA). We used a silylation reagent for chemical derivatization and used gas chromatography (GC)-mass spectroscopy ...
Hufnagel Jan Carlos - - 2008
Application of sequential solvent extraction, followed by HPLC combined with the taste dilution analysis, enabled the localization of the most intense velvety astringent, drying, and puckering astringent, as well as bitter-tasting, compounds in red wine, respectively. Isolation of the taste components involving gel adsorption chromatography, ultrafiltration, and synthesis revealed the ...
Ramachary Dhevalapally B - - 2008
The amino acid proline catalyzed the three- and five-component cascade olefination-Diels-Alder-epimerization and olefination-Diels-Alder-epimerization-olefination-hydrogenation reactions of readily available precursors enones 1a-i, arylaldehydes 2a-k, alkyl cyanoacetates 3a-e and Hantzsch ester 9 to furnish highly substituted prochiral 1-cyano-4-oxo-2,6-diaryl-cyclohexanecarboxylic acid alkyl esters 6 and 1-cyano-4-(cyano-alkoxycarbonyl-methyl)-2,6-diaryl-cyclohexanecarboxylic acid alkyl esters 10 in a highly diastereoselective fashion ...
Struijs Karin - - 2008
In flaxseed hulls, lignans are present in an oligomeric structure. Secoisolariciresinol diglucoside (SDG), ester-linked to hydroxy-methyl-glutaric acid (HMGA), forms the backbone of this lignan macromolecule. The hydroxycinnamic acids p-coumaric acid glucoside (CouAG) and ferulic acid glucoside (FeAG) are also part of the lignan macromolecule. However, their position and type of ...
Bender David M - - 2008
Esters of cyclopropanecarboxylic acid demonstrate a substantial increase in stability under both acid- and base-catalyzed hydrolytic conditions. Comparison of the stability of valacyclovir 13 with the cyclopropane analogue 14 shows that at 40 degrees C and pH 6 the half-life of 14 is >300 h while the value for 13 ...
Sato Hirofumi - - 2008
The chiral-discriminating abilities of new triazole-linked host compounds (6, 7) toward amino acid esters were evaluated by the FABMS/EL-guest method. Two types of host appending saccharide derivatives were synthesized by the copper-catalyzed Huisgen-1,3-dipolar cycloaddition (CuAAC). Host compounds binding constants and chiral-discriminating abilities toward the enantiomeric alanine esters were evaluated by ...
Miyazawa Toshifumi - - 2008
Bacillus amyloliquefaciens protease-catalyzed peptide bond formation was investigated using the carbamoylmethyl (Cam) ester as the acyl donor. A series of N-protected L-amino acid Cam esters were coupled with an L-amino acid amide in acetonitrile in good to excellent yields. The superiority of the Cam ester for segment condensations was demonstrated ...
Yanagishita Yoshio - - 2008
Two novel types of chemically recyclable ester-containing polyurethanes, namely, a diol-diacid-type poly(diester-urethane) (PDEU) and a hydroxy acid type poly(ester-urethane) (PEU), were prepared by a green synthetic route that avoids the use of hazardous diisocyanate. The urethane linkage was introduced by the reaction of ethylene carbonate with amino alcohols and amino ...
Jung Won-Kyo - - 2008
Caffeic acid phenethyl ester has been shown to have anti-inflammatory and anti-cancer effects. We examined the effects of caffeic acid phenethyl ester on lipopolysaccharide-induced production of nitric oxide and prostaglandin E2, and expression of inducible nitric oxide synthase and cyclooxygenase-2 in RAW 264.7 macrophages. We also investigated the effects of ...
Gianini Aline S - - 2008
Esters of 2-hydroxy-4-methoxy-6-n-pentylbenzoic acid (2-8) (methyl, ethyl, butyl, pentyl, isopropyl, sec-butyl and benzyl), olivetol (9), methyl, ethyl, butyl perlatolates (10-12), 2,4-dihydroxy-6-n-pentylbenzoic acid (15), and methyl and ethyl esters of (15) were prepared through structural modifications of perlatolic acid (1) with the aim to detect new antifungal and antibacterial substances and ...
Atta-Ur-Rahman - - 2008
Investigation of roots of Rhazya stricta (Apocynanaceae) of Pakistan origin lead to isolation of two new fatty esters 9-octadecenoic acid-2',3'-dihydroxy propyl ester (1) and hexadecanoic acid-2',3'-dihydroxy propyl ester (2). Linked scan MS measurements were used to propose a mass fragmentation pattern for the fatty ester 9-octadecenoic acid-2',3'-dihydroxy propyl ester.
Choquenet Benjamin - - 2008
Topical sunscreens have been used for many years on exposed areas to protect the skin from the damaging effects of ultraviolets. If the sunscreens were essential, it is suggested that they have adverse effects. We chose to study ferulic acid ethyl ester (FAEE) as agent which could potentially be used ...
Corma Avelino - - 2008
Sorbitol fatty esters have been prepared through a two-step catalytic process which involves the protection of the polyalcohol by ketalization followed by esterification with the fatty acid. Inorganic molecular sieves with different pore topologies as well as heteropolyacids (HPA) were used as acid catalysts to perform both the ketalization and ...
Solinas Rosanna - - 2008
The imidazole-4,5-dicarboxylic acid scaffold is readily derivatized with amino acid esters and alkanamines to afford compounds with intramolecularly hydrogen bonded conformations that mimic substituted purines and therefore are hypothesized to be potential inhibitors of kinases through competitive binding to the ATP site. In this work, a total of 126 dissymmetrically ...
Adam Frédérick - - 2008
In the current energetic context (increasing consumption of vehicle fuels, greenhouse gas emission etc.) government policies lead to mandatory introduction in fossil fuels of fuels resulting from renewable sources of energy such as biomass. Blending of fatty acid alkyl esters from vegetable oils (also known as biodiesel) with conventional diesel ...
Villar-González A - - 2008
The contamination of different types of shellfish by okadaic acid (OA)-group toxin esters is an important problem that presents serious risk for human health. During previous investigations carried out in our laboratory by liquid chromatography coupled with tandem mass spectrometry (LC/MS/MS), the occurrence of a high percentage of esters in ...
Dumlao Darren S - - 2008
The Saccharomyces cerevisiae methyltransferase encoded by TMT1 catalyzes the AdoMet-dependent monomethylation of 3-isopropylmalate, an intermediate of the leucine biosynthetic pathway. The biological significance of methylating 3-isopropylmalate and the relationship between Tmt1 and the leucine biosynthetic pathway is not yet established. We present evidence here showing that methylation of 3-isopropylmalate functions ...
Robosky Lora C - - 2008
A NMR spectroscopic method is described that enables the quantitation of specific lipid classes and components, independent of fatty acid composition. We demonstrate this method for measuring cholesterol, squalene, and pools of sterol esters, wax esters (WEs), and triglyceride (TG) components in sebum and meibum. When 600 MHz NMR equipment ...
Noiarsa Pawadee - - 2008
From the whole plants of Oldenlandia corymbosa of Thai origin, ten compounds have been isolated and elucidated as geniposide, 6 alpha-hydroxygeniposide, scandoside methyl ester (6 beta-hydroxygeniposide), asperulosidic acid, deacetylasperuloside, asperuloside, 10-O-benzoylscandoside methyl ester, 10-O-p-hydroxybenzoylscandoside methyl ester, (+)-lyoniresinol-3 alpha-O-beta-glucopyranoside, and rutin. Their structures were determined on the basis of spectroscopic data.
Xie Congxia - - 2008
Several plasticizer esters were synthesized by using acid-functionalized ionic liquids as catalyst. The results indicated that HSO3-functionalized Brønsted acidic ionic liquids show better catalytic and reusable performance than non-functionalized ionic liquids. For each plasticizer ester examined, one or two ionic liquids with high catalytic activity were chosen. Especially, the ionic ...
Baptista Patrícia - - 2008
Biodiesel is the main alternative to fossil diesel. The key advantages of its use are the fact that it is a non-toxic renewable resource, which leads to lower emissions of polluting gases. European governments are targeting the incorporation of 20% of biofuels in the general fuels until 2020. Chemically, biodiesel ...
Doria Filippo - - 2007
Mild photoactivation of new BINOL-amino acid and -amino ester conjugates (BINOLAMs) yielded alkylating and DNA cross-linking agents with high photoefficiency and superior cytotoxicity. Detection of the transient electrophile, by laser flash photolysis (LFP), suggests that BINOL-quinone methides (QMs) are key intermediates in the process. QMs trapping by water, monitored in ...
Heinze Thomas - - 2007
Novel bulky esters of cellulose were synthesized homogeneously, applying the solvent systems DMA/LiCl or DMSO/TBAF, by conversion of the biopolymer with aryl polyester dendrons. The carboxylic acid moieties were efficiently activated in situ with CDI or the acid chloride was applied. Cellulose esters with DS values of up to 0.7 ...
Landolt P J - - 2007
Codling moths are attracted to acetic acid and to ethyl-(E,Z)-2,4-decadienoate, the pear ester, when presented individually. The attraction to acetic acid is thought to be a food finding behavior, whereas the pear odorant, ethyl-(E,Z)-2,4-decadienoate, may be a host kairomone. We found, in a flight tunnel study, that more male and ...
Bodet Charles - - 2008
The aim of this study was to investigate the effect of 3-(4'-geranyloxy-3'-methoxyphenyl)-2-trans propenoic acid, active principle isolated from Acronychia baueri Schott, and its ester derivatives on biofilm formation by two important oral pathogens, Porphyromonas gingivalis and Streptococcus mutans. The parent acid and conjugates with vanillic acid, 2-hydroxynaphthoquinone and guaiacol caused ...
Saerens S M G - - 2008
Volatile esters are responsible for the fruity character of fermented beverages and thus constitute a vital group of aromatic compounds in beer and wine. Many fermentation parameters are known to affect volatile ester production. In order to obtain insight into the production of ethyl esters during fermentation, we investigated the ...
Yasui Eiko - - 2007
Versatile electrophiles N-acylhydrazones are synthesized via diazotization, reduction, and acylation of alpha-amino acid esters. Reduction of diazo esters with L-selectride or tributylphosphine affords the corresponding hydrazones in good yields. Both reducing agents give anti-hydrazones as the major product although the reactivity of each reductant is slightly different. The resulting hydrazones ...
Corr Lorna T - - 2007
A novel derivatization procedure, N-acetyl methyl (NACME) esterification, was developed to improve the accuracy and precision of amino acid delta13C value determination using gas chromatography-combustion-isotope ratio mass spectrometry (GC/C/IRMS). Standard mixtures of 15 protein amino acids were converted to NACME and N-acetyl-isopropyl (NAIP) esters; the latter established derivative was employed ...
Matsumoto Masaomi - - 2007
Histidine-derived hydrazide acetal monomers (3-dimethoxymethylbenzoyl)-L-histidine methyl ester 1 and (3-dimethoxymethylbenzoyl)-tau-benzyl-L-histidine methyl ester 2 were prepared from a histidine methyl ester and a tau-benzyl-histidine methyl ester by N-acylation with 3-(dimethoxymethyl)benzoic acid (3) followed by hydrazinolysis. Acid-promoted hydrolysis of each acetal hydrazide initially produced a library of cyclic oligomers that eventually converted ...
Isayama Yohei - - 2008
In order to prepare a genuine biodiesel, it is essential to use methanol prepared from biomass but not natural gas for biodiesel production. Thus, we have proposed to use crude bio-methanol produced by wood gasification for biodiesel production. Since such a bio-methanol contains some impurities, an effect of its impurities ...
Kiran Kumar S T V S - - 2008
Carbodithioic acid esters of fluoxetine have been prepared by replacing the methylamino function in aminopropane chain with carbodithioic acid ester group and by adding various S-2-hydroxypropyl ester of dialkyl carbodithioic acid at 3-methylamino group. Some of these compounds showed spermicidal, antifungal and anti-Trichomonas activities. The study revealed that incorporation of ...
Shehata Mohamed R - - 2008
The complex-formation equilibria of [Pd(SMC)(H2O)2]+, where SMC = S-methyl-l-cysteinate, with bio-relevant ligands such as amino acids, peptides, dicarboxylic acids and DNA constituents were studied and their formation constants were determined. The binding mode of the ligands containing various functional groups was studied and the speciation diagrams were evaluated. The kinetics ...
Metcalf Matthew D MD Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, 20 Penn Street, Room 637, Baltimore, MD 21201, - - 2008
To investigate the effects of carboxylic ester and acid moieties as the N-substituent of opioids, a short series of racemic N-substituted normetazocines was prepared. The introduction of both groups as the normetazocine N-substituent produced compounds which displayed low potency in vitro and in vivo, with the esters displaying the greater ...
Gerber Minja - - 2008
The objective of this study was to determine the in vitro transdermal permeation through human epidermis of zalcitabine, lamivudine and the synthesised N-acyl lamivudine esters, with and without the use of Pheroid as delivery system and to establish a correlation, if any, with selected physicochemical properties. Six N-acyl lamivudine esters ...
Tsuchiyama Moriyasu - - 2007
We found that hydroxycinnamic acid (HA) glycerol esters such as 1-sinapoyl glycerol and 1-p-coumaroyl glycerol can be synthesized through a direct esterification reaction using a type A feruloyl esterase from Aspergillus niger. The water solubilities of HA glycerol esters were higher than those of the original chemicals. HA glycerol esters ...
Sekizaki Haruo - - 2007
A facile synthetic method for p- and m-(amidinomethyl)phenyl esters derived from a variety of amino acids is presented. We analyzed the kinetic behavior of trypsin towards these synthetic esters, which are inverse substrates. The substituent (meta- and para-isomers) and isosteric effects of (amidinomethyl)phenyl esters are discussed.
Fousteris Manolis A - - 2007
This study was designed as a rational continuation of our research regarding the functional requirements essential for the antileukemic activity of compounds comprising an alkylating moiety and a modified steroid. The steroidal esteric derivatives of 4-methyl-3-N,N-bis(2-chloroethyl)amino benzoic acid were tested on leukemias P388 and L1210 in vivo and in normal ...
Cione E - - 2008
Ferulic acid plays a chemopreventive role in cancer by inducing tumor cells apoptosis. As mitochondria play a key role in the induction of apoptosis in many cells types, here we investigate the mitochondrial permeability transition (MPT) and the release of cytochrome c induced by ferulic acid and its esters in ...
Chen Qilin - - 2007
Fatty acyl esters of phytosterols are a major form of sterol conjugates distributed in many parts of plants. In this study we report an Arabidopsis (Arabidopsis thaliana) gene, AtSAT1 (At3g51970), which encodes for a novel sterol O-acyltransferase. When expressed in yeast (Saccharomyces cerevisiae), AtSAT1 mediated production of sterol esters enriched ...
Rowe Gerald E - - 2008
Thermodynamic analysis of hydrophobic interaction chromatography of amino acid methyl esters showed entropy-driven adsorption, consistent with solvophobic theory, except for phenyl ester on the Toyopearl resins. All esters adsorbed more strongly to the Toyopearl resins, including the polymethacrylate base matrix, than to Butyl Sepharose. Enthalpy changes were more favorable with ...
Wang Pei-Yun - - 2007
A thermally stable esterase (SNSM-87) from Klebsiella oxytoca is explored as an enantioselective biocatalyst for the hydrolytic resolution of (R,S)-2-hydroxycarboxylic acid esters in biphasic media, where the best methyl esters possessing the highest enantioselectivity and reactivity are selected and elucidated in terms of the structure-enantioselectivity correlations and substrate partitioning in ...
Kumooka Y - - 2008
The optimum method for analyzing glyceryl rosinate by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) was studied. The performances of dithranol, anthracene, and 2,5-dihydroxybenzoic acid, pyrene, trans,trans-1,4-diphenyl-1,3-butadiene, 9-nitroanthracene, indole-3-acrylic acid and retinoic acid as a matrix agent, and those of sodium trifluoroacetate (NaTFA) and silver trifluoroacetate (AgTFA) as a cationization ...
Badkar Pallavi A - - 2007
Allylic acetates, formed by the acetylation of Baylis Hillman adducts, undergo addition of phosphorus nucleophiles to give stereoselectively the Z-unsaturated esters. TFA cleavage of the tert-butyl ester and asymmetric hydrogenation of the unsaturated acid yields the phosphono alkyl propanoic acid moiety, commonly found in phosphonate- and phosphinate-based enzyme inhibitors.
Ando Yasuhiro - - 2007
This paper proposes a one-step method for preparation of fluorescent 9-anthrylmethyl esters from triacylglycerols (TAG) ranging in amount from 0.1 to 5 microg. It involves base-catalyzed transesterification using potassium 9-anthracenemethoxide, prepared by proton exchange between 9-anthracenemethanol and potassium tert-butoxide. Transesterification for 10 min at room temperature gave the fatty acid ...
Nechab Malek - - 2007
Optimization of the kinetic resolution of 2-amino-4-phenyl-butane was achieved at 80 degrees C using CAL-B-catalyzed aminolysis of carboxylic acids and their ethyl esters. The reactions carried out with long chain esters and the corresponding acids as acyl donors proceeded with remarkably high enantioselectivity. The use of carboxylic acids as acylating ...
Jiang Xiaomei - - 2007
4-Methyl-piperazine-1-carbodithioic acid 3-cyano-3,3-diphenylpropyl ester hydrochloride (TM-208) is a newly synthesized compound, which has shown excellent in vivo and in vitro anticancer activity and low toxicity. To investigate the metabolism of TM-208 in rats, in the present study, we administered TM-208 orally to rats and analyzed its metabolites existing in rat ...
Doucet Erin - - 2007
Okadaic acid (OA) and dinophysistoxins-1 and -2 (DTX1, DTX2), the toxins responsible for incidents of diarrhetic shellfish poisoning (DSP), can occur as complex mixtures of ester derivatives in both plankton and shellfish. Alkaline hydrolysis is usually employed to release parent OA/DTX toxins, and analyses are conducted before and after hydrolysis ...
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