Search Results
Results 251 - 300 of 1646
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Yamasaki Masao - - 2009
Alpha-lipoic acid has been shown to possess cancer-cell-killing activity via activation of the apoptosis pathway. In this study, the cytotoxic activities of alpha-lipoic and dihydro-alpha-lipoic acid were compared in HL-60 cells. The cell-killing activity of dihydro-alpha-lipoic acid was higher than that of alpha-lipoic acid. Both alpha-lipoic and dihydro-alpha-lipoic acid induced ...
Vallianou Natalia - - 2009
Diabetic neuropathy presents a major public health problem. It is defined by the symptoms and signs of peripheral nerve dysfunction in diabetic patients, in whom other causes of neuropathy have been excluded. Pathogenetic mechanisms that have been implicated in diabetic neuropathy are: a) increased flux through the polyol pathway, leading ...
Brückner Hans - - 2009
Fourty-nine species and strains of filamentous fungi of the genera Acremonium, Bionectria, Clonostachys, Emericellopsis, Hypocrea/Trichoderma, Lecythophora, Monocillium, Nectriopsis, Niesslia, Tolypocladium, and Wardomyces, deposited with the culture collection of the Centraalbureau voor Schimmelcultures (CBS) in Utrecht, The Netherlands, were grown on nutrient agar plates. Organic extracts of mycelia were analyzed after ...
DeFilippis Andrew P - - 2009
We previously reported a >50% increase in mean plasma eicosapentaenoic acid levels in a general medicine clinic population after supplementation with alpha-linolenic acid. In the current analysis, we evaluate the variability of changes in eicosapentaenoic acid levels among individuals supplemented with alpha-linolenic acid and evaluated the impact of baseline plasma ...
Narendra N - - 2009
We report a one pot synthesis of Fmoc amino acid derived 4-amino-thiazole derivatives and thiazole linked N-orthogonally protected dipeptidomimetics by the condensation of N(alpha)-Fmoc alpha-halomethylketones with thiourea and Boc/Z-alpha-amino acid thioamides via modified Hantzch protocol. Side chain modified Fmoc amino acids containing 4-amino thiazole moiety have also been synthesized following ...
Günther Svenja - - 2009
Lipoic acid (LA) is a dithiol-containing cofactor that is essential for the function of alpha-keto acid dehydrogenase complexes. LA acts as a reversible acyl group acceptor and 'swinging arm' during acyl-coenzyme A formation. The cofactor is post-translationally attached to the acyl-transferase subunits of the multienzyme complexes through the action of ...
Tanaka Hiroshi - - 2008
An efficient synthesis of alpha(2,9) trisialic acid has been achieved via one-pot glycosylation and polymer-assisted deprotection. The synthesis involves chemo- and regioselective alpha-sialylation of ethylthiosialoside with the S-benzoxazolyl (S-Box) sialyl donor. Use of a prelinker to link an activated ester and a vinyl ether via a carbon chain enables polymer-assisted ...
Zembron-Lacny A - - 2009
The aim of this study was to follow up whether the modification of pro-antioxidant status by oral thiol administration such as N-acetylcysteine and alpha-lipoic acid affects the hematological response. Twenty-eight healthy men participated in two independent experiments. Subjects were randomly assigned to one of four groups: controls (C(NAC) and C(ALA)), ...
Sado-Kamdem Sylvain L - - 2009
The antimicrobial activity of alpha-linolenic, capric and lauric acids on Staphylococcus aureus was studied in relation to their effect on the de novo fatty acid biosynthesis. Labelled acetate was used as integrated carbon source and traced in the de novo fatty acid by using a GC-Mass spectrometer and the single ...
Uchigata Yasuko - - 2009
Although insulin autoimmune syndrome (IAS) was found to be strongly related with methimazole, rapidly increasing numbers of cases with alpha lipoic acid-induced IAS have been confirmed to be reported since 2003. As alpha lipoic acid has gained popularity as a supplement for dieting and anti-aging, a warning should be issued.
Taber Douglass F - - 2008
A strategy for the facile alpha-amination of carboxylic acid menthyl esters is described. The resulting diastereomers, readily separable, can be individually carried on to each enantiomer of the FMOC alpha-amino acid. A variety of unnatural side chains were compatible with this approach. The menthyl ester was easily removed from the ...
Di Gioia Maria Luisa - - 2010
A convenient route for the synthesis of lipophilic N-Fmoc-N-methyl-alpha-amino acids and N-nosyl-N-methyl-alpha-amino acids, interesting building blocks to be used for the preparation of N-methylated peptides, is presented. Both nosyl- and Fmoc-protected monomers are accessible, so these compounds can be used in solution as well as in solid phase peptide synthesis. ...
Ohta Atsushi - - 2008
Over 30 years ago, Fahnestock and Rich reported intriguing data showing the capability of the ribosome to polymerize phenyllactic acid. Although the polymerization was initiated and terminated randomly on polyuridic acids, the given data convincingly suggested that the generated polymer was composed of an approximately 7:3 mixture of phenyllactic acid ...
Lee Charles C - - 2009
Glucuronic acid is a common chemical moiety that decorates the xylan polymer of hemicellulose. This chemical substituent impairs both enzymatic and acidic hydrolysis of xylosidic bonds. The alpha-glucuronidase enzyme hydrolyzes the 1,2-linked glucuronic acid from the terminal, non-reducing xylose of xylo-oligosaccharides. There are relatively few alpha-glucuronidase genes in the public ...
Bongo Nlandu B - - 2009
A novel photoreactive alpha-amino acid bearing an acidic residue and a cleavable diazirine was developed. To mimic common acidic alpha-amino acids, the residue was designed to be N-acylsulfonamide that possesses an acidic proton and is able to dissociate under the physiological conditions. The inhibition assay of its biotin-tagged derivative with ...
Karaman Rafik - - 2009
AM1 semi-empirical molecular orbital and ab initio HF at the 6-31G level calculations for the lactonization processes of 12 different hydroxy acids (1a-1l) which differ in their structural features have been conducted. The calculations obtained reveal the following: (1) The rate-limiting step in the lactonization process is formation of a ...
Brinkevich S D - - 2008
Effects of ascorbic acid and 5,6-O-isopropylidene-2,3-O-dimethylascorbic acid on final product formation in radiolysis of ethanol, aqueous solutions of ethanol, ethylene glycol, alpha-methylglycoside, maltose, alpha-glycerophosphate, and alpha-glucose phosphate were studied. It was found that ascorbic acid is able to suppress reactions involving various alpha-hydroxyl-containing carbon-centered radicals and depending on the experimental ...
Merkler David J - - 2008
Peptidyl alpha-hydroxylating monooxygenase (PHM) functions in vivo towards the biosynthesis of alpha-amidated peptide hormones in mammals and insects. PHM is a potential target for the development of inhibitors as drugs for the treatment of human disease and as insecticides for the management of insect pests. We show here that relatively ...
Brown Zachary Z - - 2008
The creation of highly hindered peptides that contain combinations of non-natural N-alkyl amino acids and N-alkyl-alpha,alpha-disubstituted amino acids presents a formidable challenge. Hindered, non-natural amino acids are of interest because they import resistance to proteolysis and unusual conformational properties to peptides that contain them. Toward a solution to this problem, ...
Mukherjee Debaraj D Bio-organic Chemistry Division, Indian Institute of Integrative Medicine (CSIR), Canal Road, Jammu, - - 2008
Lewis acid mediated one-pot transformation of D-glucal in the presence of nucleophiles leads to the formation of racemic alpha-substituted alpha-hydroxymethyl furfuryl derivatives, versatile synthons for biologically active molecules. Transformations using O-, S-, C-, and N-nucleophiles could be achieved readily under mild and scalable conditions. Indium triflate proved to be the ...
Wang Lei - - 2008
Hypertriglyceridemia and associated high circulating free fatty acids are important risk factors for atherosclerosis. In contrast to omega-3 fatty acids, linoleic acid, the major omega-6 unsaturated fatty acid in the American diet, may be atherogenic by amplifying an endothelial inflammatory response. We hypothesize that omega-6 and omega-3 fatty acids can ...
Nieuwendaal Ryan C - - 2008
We have detected a phase transition during the progress of the solid-state [2 + 2] photocycloaddition reaction of alpha-trans-cinnamic acid. The reaction was monitored using (13)C CPMAS experiments as a function of irradiation time of the parent alpha-trans-cinnamic acid, which forms the product dimer, alpha-truxillic acid. UV light centered at ...
Juan Yung-Shun - - 2008
PURPOSE: Recent evidence indicates that ischemia and reperfusion are major etiological factors in the bladder dysfunction that occurs after partial bladder outlet obstruction. Coenzyme Q10 and alpha-lipoic acid are found naturally in mitochondria and act as potent antioxidants. We investigated the beneficial effects of coenzyme Q10 plus alpha-lipoic acid in ...
Omata Kenji - - 2008
(1)H NMR analyses of individual alpha-amino acids in their mixture were simultaneously conducted in the presence of Sm-(pdta-d(8)) in water: high regularity, promising for direct simultaneous determination of absolute configurations of each alpha-amino acids in peptide hydrolysate mixtures, was observed between absolute configuration and the induced shifts.
Li Xiang - - 2008
Naturally occurring peptides serve important functions as enzyme inhibitors, hormones, neurotransmitters, and immunomodulators in many physiological processes including metabolism, digestion, pain sensitivity, and the immune response. However, due to their conformational flexibility and poor bioavailability, such peptides are not generally viewed as useful therapeutic agents in clinical applications. In an ...
Ma Chao-Mei - - 2008
Alpha-glucosidases play important roles in the digestion of carbohydrates and biosynthesis of viral envelope glycoproteins. Inhibitors of alpha-glucosidase are promising candidates for the development of antitype II diabetics and anti-AIDS drugs. Here, we report the synthesis and alpha-glucosidase inhibitory activity of mono- and diketal/acetal derivatives of chlorogenic acid. The diketal ...
Melli Giorgia - - 2008
The study investigates if alpha-lipoic acid is neuroprotective against chemotherapy induced neurotoxicity, if mitochondrial damage plays a critical role in toxic neurodegenerative cascade, and if neuroprotective effects of alpha-lipoic acid depend on mitochondria protection. We used an in vitro model of chemotherapy induced peripheral neuropathy that closely mimic the in ...
Tayama Eiji - - 2008
The Stevens rearrangement of N-allylic alpha-aryl amino acid-derived ammonium salts and the Sommelet-Hauser rearrangement of N-benzylic alpha-alkyl amino acid-derived ammonium salts are shown to proceed with remarkably high levels of diastereoselectivity. The methods presented in this work provide new routes to optically active alpha-quaternary alpha-aryl amino acid derivatives.
Kunimune Takeshi - - 2008
Foam-stabilizing properties and cling formation patterns of iso-alpha-acids and reduced iso-alpha-acids were investigated using an unhopped lager beer. Unhopped beer was dosed with iso-alpha-acid (Iso), rho-iso-alpha-acid (Rho), tetrahydro-iso-alpha-acid (Tetra), and hexahydro-iso-alpha-acid (Hexa), separately, over a range of concentrations from 2 to 10 ppm. A uniform foam was created by Inpack ...
Bahde Robert J - - 2008
We report a new route to tertiary alpha-amino stereocenters by sequential alkylation of alpha-amino nitriles followed by reductive lithiation of the nitrile and cyclization onto an alkene. Reductive lithiation of alpha-amino nitriles using lithium 4,4'-di-tert-butylbiphenylide (LiDBB) and subsequent intramolecular carbolithiation proceeded with modest to high diastereoselectivity to deliver cyclic or ...
Moriyama Katsuhiko - - 2008
The intramolecular alpha-alkylation of beta-alkoxy-alpha-amino esters derived from L-serine proceeded predominantly over beta-elimination. When beta-alkoxy-alpha-amino esters were treated with powdered CsOH in DMSO at 20 degrees C, alpha-alkoxymethyl cyclic amino esters were obtained in up to 94% ee. Optically active THF amino acids were synthesized for the first time by ...
Sasaki Tsukasa - - 2008
We developed a novel derivatization reagent, (2R)-2,5-dioxopyrrolidin-1-yl-2,5,7,8-tetramethyl-6-(tetrahydro-2H-pyran-2-yloxy)chroman-2-carboxylate (NPCA), for electrochemical (EC) detection in HPLC. NPCA was synthesized from (R)-(+)-6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (alpha-CA), which exhibits intense EC response. NPCA successfully yielded alpha-CA derivatives of primary amines by a two-step derivatization procedure. Following pre-column derivatization with NPCA, a simultaneous determination of alpha-CA derivatives ...
Ibrahim Siti Fatimah - - 2008
Assisted reproductive techniques are useful in helping infertile couples achieve successful conception. Initial studies have shown that sperm cryopreservation, one step in assisted reproduction, causes a dramatic reduction in sperm quality. This has been attributed to, among other things, free radical activities. The aim of the present study was to ...
Benbrahim Nasséra - - 2008
alpha-Aminophosphonic acids are analogues of natural alpha-aminoacids and very promising agents for use in various pharmaceutical applications. However, in contrast to the numerous theoretical investigations on the structure of natural alpha-aminoacids, only very few studies on alpha-aminophosphonic acids have been performed. In the present work, we report a detailed investigation ...
Arora Jasbir Singh - - 2008
A new amide-forming reaction with N-benzoyloxyamines and alpha-ketophosphonic acids was investigated. A mixed solvent of t-BuOH/water (1:1) at 40 degrees C provided the desired amide in high yield (71-96%). Both phosphonic acids ( 9, 12, or 13) and their disodium salts (e.g., 10) were shown to react with the respective ...
Ingratta Mark - - 2008
Two series of pyrene-labeled poly(glutamic acid) (Py-PGA) were synthesized utilizing two different linkers for pyrene attachment, namely 1-pyrenemethylamine (PMA) and 1-pyrenebutylamine (PBA). Several Py-PGAs were synthesized for each series with pyrene contents ranging from 4 to 15 mol %. Py-PGA forms a rigid alpha-helix in DMF that effectively locks the ...
Jaskula Barbara - - 2008
In this article, a detailed study on hop alpha-acid isomerization kinetics is presented. Because of the complex wort matrix and interfering interactions occurring during real wort boiling (i.e., trub formation and alpha-acids/iso-alpha-acids complexation), this investigation on alpha-acid isomerization kinetics was performed in aqueous buffer solution as a function of time ...
Cavelier Florine - - 2008
New alpha,alpha'-disubstituted amino acids with silylated side chains have been synthesized in racemic form. Starting from a Schiff base of glycine tert-butyl ester, a large variety of alpha,alpha'-dialkylated amino acids has been obtained, depending on the alkylating reagents. The application of a hydrosilylation methodology enabled the synthesis of the same ...
Smits René - - 2008
The combination of the unique physical and chemical properties of fluorine with proteinogenic amino acids represents a new approach to the design of biologically active compounds including peptides with improved pharmacological parameters. Therefore, the development of routine synthetic methods which enable the effective and selective introduction of fluorine into the ...
An S M - - 2008
BACKGROUND: Recent study has demonstrated that Sasa quelpaertensis (Korean name, Jeju-Joritdae) extracts inhibit cellular melanogenesis implicating potential use in the control of skin pigmentation. OBJECTIVES: The purpose of the present study was to elucidate the active constituents of this plant inhibiting melanogenesis and the associated mechanism. METHODS: The effect of ...
Barbana C - - 2008
The interaction of holo- and apo-forms of human alpha-lactalbumin with fatty acids was studied by a partition equilibrium method. Apo-alpha-lactalbumin, obtained by treatment with EDTA, displays one binding site for fatty acids, the association constants for oleic and palmitic acids being 1.9.10(6) and 4.2.10(5) M(-1), respectively. However, holo-alpha-lactalbumin was unable ...
Soczynska Joanna K - - 2008
BACKGROUND: Mood disorders are associated with decrements in cognitive function, which are insufficiently treated with contemporary pharmacotherapies. OBJECTIVES: To evaluate the putative neurotherapeutic effects of the mitochondrial cofactors, L-carnitine, acetyl-L-carnitine, and alpha-lipoic acid; and to provide a rationale for investigating their efficacy in the treatment of neurocognitive deficits associated with ...
Wu Guanghua - - 2008
Parkinson's disease (PD) is a progressive neurodegenerative disease that affects aged people. Although a number of genes have been linked to familial PD, the genetic causes of sporadic PD that accounts for 90% of all PD cases remain unclear. Accumulating evidence has demonstrated that alpha-synuclein aggregation is essential to the ...
Hybelbauerová Simona - - 2008
Metabolites of the wood-rotting fungus Stereum subtomentosum Pouzar (Basidiomycetes, order Russulales, family Stereaceae) occurring on birch (Betula pendula Roth) trees were phytochemically investigated for the first time. Three main metabolite chemotypes present in MeOH extracts of the fruit bodies, viz. steroids, fatty acids, and water-soluble sugars, were fractionated, isolated, and ...
Maina Ndegwa Henry - - 2008
Dextrans are the main exopolysaccharides produced by Leuconostoc species. Other dextran-producing lactic acid bacteria include Streptococci, Lactobacilli, and Weissella species. Commercial production and structural analysis has focused mainly on dextrans from Leuconostoc species, particularly on Leuconostoc mesenteroides strains. In this study, we used NMR spectroscopy techniques to analyze the structures ...
Dickstein Joshua S - - 2008
Alpha-iminoesters are useful precursors to substituted alpha-amino acid derivatives and are utilized in a number of organic transformations. As a consequence of the adjacent ester functionality, these imines are more reactive relative to other types of imines. While a significant body of work has focused on nucleophilic additions to the ...
Borah Jayanta M - - 2008
Adsorption kinetics, adsorption isotherms and surface complexation of trimesic acid onto alpha-alumina surfaces were investigated. Adsorption kinetics of trimesic acid with an initial concentration of 0.5 mM onto alpha-alumina surfaces were carried out in batch method in presence of 0.05 mM NaCl (aq) at pH 6 and 298.15, 303.15 and ...
Huguenot Florent - - 2008
Difluoroenol silyl ethers, produced in situ from acylsilanes and CF3TMS, react as electrophiles with amines to give difluoroimines, via the corresponding hemiaminal adduct, as evidenced by 19F NMR spectroscopy. Reaction with (R)-phenylglycinol led to 2-difluoromethyloxazolidines. After separation of the diastereomers, reduction with LAH and Strecker-type synthesis gave enantiopure alpha-difluoromethylamines and ...
Matteson Donald S - - 2008
This review includes a personal account of the history of the development of the alpha-amido boronic acid synthesis and related chemistry in the author's laboratory, as well as a review of some of the more significant developments that have occurred elsewhere more recently. The simple initial target, suggested by biochemist ...
Ahmed Safwat A - - 2008
Eleven new cannabinoid esters, together with three known cannabinoid acids and Delta9-tetrahydrocannabinol ( Delta9-THC ), were isolated from a high-potency variety of Cannabis sativa. The structures were determined by extensive spectroscopic analyses to be beta-fenchyl Delta9-tetrahydrocannabinolate ( 1), epi-bornyl Delta9-tetrahydrocannabinolate ( 2), alpha-terpenyl Delta9-tetrahydrocannabinolate ( 3), 4-terpenyl Delta 9-tetrahydrocannabinolate ( ...
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