Search Results
Results 401 - 450 of 1526
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Goto Koichi - - 2002
With respect to the hydrolysis (deacylation) of Z-D(L)-amino acid esters (N-(benzyloxycarbonyl)-D(L)-amino acid p-nitrophenyl esters) mediated by alpha-, beta- and gamma-cyclodextrins (CyDs), a remarkably high enantioselectivity (L/D=9.0) was observed for the deacylation of Ala substrate with gamma-CyD. The kinetic results on the basis of the Michaelis-Menten principle indicate that the enantioselectivity ...
Aliyev Nadir N - - 2002
OBJECTIVE: The importance of serum levels of amino-acid neurotransmitters and of relevant enzymes has not been adequately evaluated in alcoholics. It is hypothesized that several of these neurotransmitters would be likely to be elevated in alcoholics overall, those with alcoholic withdrawal and, especially, individuals undergoing severe withdrawal as might be ...
Bereiter D A - - 2002
The neurological basis for painful temporomandibular disorders (TMD) and the higher prevalence of TMD pain in women than men is not known. To better define the circuitry and neurochemical mechanisms in the lower brainstem associated with noxious sensory inputs from the temporomandibular joint (TMJ) region a microdialysis method was used ...
Gupta Maneesh - - 2002
Therapeutic intervention for human succinic semialdehyde dehydrogenase (SSADH) deficiency (gamma-hydroxybutyric aciduria) has been limited to vigabatrin (VGB). Pharmacologically, VGB should be highly effective due to 4-aminobutyrate-transaminase (GABA-transaminase) inhibition, lowering succinic semialdehyde and, thereby, gamma-hydroxybutyric acid (GHB) levels. Unfortunately, clinical efficacy has been limited. Because GHB possesses a number of potential ...
Pirianowicz-Chaber Elzbieta - - 2002
Qualitative and quantitative methods of analysis of two new amino acid derivatives, potential anticonvulsants of low neurotoxicity: N-acetyl-gamma-aminobutyric acid benzylamide (1) and N-melhyl-gamma-aminobutyric acid benzylamide (2) were developed. Qualitative analysis includes characteristic colour reactions, chromatographic (TLC) investigations, IR and UV spectra interpretation and quantitative analysis involves spectrophotometric, chromatographic (HPLC). acidimetric ...
Pearson Anthony J - - 2002
[reaction: see text] pi-Allylmolybdenum complex 6b is obtained as a single isomer by Knoevenagel condensation of aldehyde 1 with Meldrum's acid. Conjugate additions of Grignard reagents to Meldrum's acid alkylidene derivative 6b are shown to be completely diastereoselective. Further functional group transformation of the 1,4-adducts, followed by demetalation, leads to ...
Zachariae Ulrich - - 2002
The functional properties of the anion-selective porin Omp32 from the bacterium Delftia acidovorans, formerly Comamonas acidovorans, are determined by the particularly narrow channel constriction and the electrostatic field inside and outside the pore. A cluster of arginines (Arg 38, Arg 75, and Arg 133) determines the electrostatic field close to ...
Kim Yong - - 2002
Dibenzyl-g-butyrolactone and 1,2,3,4-tetrahydro-2-naphthoic acid gamma-lactone (TNL) derivatives were synthesized and evaluated for cytotoxic activity against some cancer cell lines. It was found that TNL derivatives with a shorter distance between C-4 in ring A and C'-2 in ring C were more cytotoxic, while dibenzyl-gamma-butyrolactones with a longer one were nearly ...
Herrero Susana - - 2002
2-Oxopiperazine derivatives 1 have been designed as mimetics of gamma-turn conformationally constrained tripeptides. The synthetic pathway devised for the preparation of both epimers of 1 at C(5) involves a reductive amination of cyanomethyleneamino pseudopeptides with amino acid derivatives, followed by regiospecific lactamization of the resulting C-backbone branched pseudopeptides. The versatility ...
Stewart Allison - - 2002
The enzymatic properties of cytosolic phospholipase A(2)gamma (cPLA(2)gamma), an isoform of 85-kDa group IV cPLA(2)alpha (cPLA(2)alpha) were studied in vitro and when the enzyme was expressed in cells. cPLA(2)gamma expressed in Sf9 cells is associated with membrane. Membranes isolated from [(3)H]arachidonic acid-labeled Sf9 cells expressing cPLA(2)gamma, constitutively release [(3)H]arachidonic acid. ...
Zhang Xu-Ying - - 2002
In the present communication, we determined the dynamic release of amino acid transmitters from spinal dorsal horn induced by scorpion Buthus martensi Karsch (BmK) venom and a neurotoxin (BmK I). The results found that glutamate and aspartate release could be evoked significantly within the initial 30 min with the applied ...
Carai Mauro A M - - 2002
The aliphatic alcohol 1,4-butanediol in converted into gamma-hydroxybutyric acid (GHB) via two enzymatic steps: first, it is oxidised by alcohol dehydrogenase in gamma-hydroxybutyraldehyde; second, the latter is transformed, likely by aldehyde dehydrogenase, into GHB. Initially, the present study compared the sedative/hypnotic effect of GHB and 1,4-butanediol, measured as loss of ...
Stintzing Florian C - - 2002
Betaxanthins, the yellow-orange water-soluble pigments from yellow beet (Beta vulgaris ssp. vulgaris cv. Bejo Zaden) and cactus pear (Opuntia ficus-indica cv. Gialla) have been investigated using an HPLC system compatible with mass spectrometry. Five novel betaxanthins were found and characterized as the immonium adducts of betalamic acid with serine, gamma-aminobutyric ...
Kuroda M - - 2002
Changes in the amino acid composition and contents of gamma-glutamyl-beta-alanyl-histidine isopeptide in the macromolecular fraction were measured during heating of chicken extract. Increases of histidine, 1-methylhistidine, and beta-alanine were observed, suggesting that carnosine and anserine were incorporated into the macromolecular fraction. The increase of gamma-glutamyl-beta-alanylhistidine isopeptide in the macromolecular fraction ...
Brown M A - - 2002
gamma-Carboxyglutamic acid (Gla) is an unusual amino acid that is synthesized post-translationally from glutamate in a vitamin K-dependent reaction. The dicarboxylic side chain of Gla chelates Ca(2+), a property important for the biological activity of vitamin K-dependent proteins. To date, Gla-containing polypeptides have been identified in venom from two groups ...
Amir Rachel - - 2002
The sulfur-containing amino acid methionine is a nutritionally important essential amino acid and is the precursor of several metabolites that regulate plant growth and responses to the environment. Methionine production is largely regulated by cystathionine gamma-synthase, the first specific enzyme for its synthesis. This enzyme competes in a complex manner ...
Iacazio G - - 2002
During a screening procedure for the discovery of a strong gamma-decalactone producer from ricinoleic acid, we observed that the yeast Pichia guilliermondii accumulated transiently 8-hydroxy-3Z,5Z-tetradecadienoic acid 1 during gamma-decalactone biosynthesis in the stationary phase of growth. The structural elucidation of 1 was based on nuclear magnetic resonance, infrared, ultraviolet and ...
García-Santos M del Pilar Mdel - - 2002
Nitrosation reactions of amino acids with an -NH(2) group [namely, six alpha-amino acids (glycine, alanine, alpha-aminobutyric acid, alpha-aminoisobutyric acid, valine, and norvaline); two beta-amino acids (beta-alanine and beta-aminobutyric acid), and one gamma-amino acid (gamma-aminobutyric acid)] were studied. Nitrosation was carried out in aqueous acid media, mimicking the conditions of the ...
Rump P - - 2002
AIMS/HYPOTHESIS: According to the foetal origins hypothesis, there is a relation between foetal nutrition and adult glucose intolerance. In adults, insulin resistance has been associated with dietary polyunsaturated fatty acids. We examined whether the availability of polyunsaturated fatty acids during foetal life, as indicated by the fatty acid composition of ...
Dahlén Johan - - 2002
A micellar electrokinetic chromatography (MEKC) method was optimised for simultaneous analysis of gamma-hydroxybutyric acid (GHB), gamma-butyrolactone (GBL), and 1,4-butanediol (BD). Best conditions for separation and baseline stability were achieved using a carrier electrolyte comprising 30.0mM sodium barbital and 150.0mM sodium dodecyl sulphate (SDS) at pH 10.2. Calibration functions were linear, ...
Seebach Dieter - - 2002
There are numerous possible gamma-amino acids with different degrees of substitution and with various constitutions and configurations. Of these the gamma4- and the like- and unlike-gamma(2,4)-amino acids have been previously used as building blocks in gamma-peptides. The synthesis of gamma2-, gamma3-, and gamma(2,3,4)-peptides is now described. The corresponding amino acids ...
Reggio Patricia H - - 2002
Anandamide (N -arachidonoylethanolamine) was the first ligand to be identified as an endogenous ligand of the G-protein coupled cannabinoid CB1 receptor. Subsequently, two other fatty acid ethanolamides, N -homo- gamma -linolenylethanolamine and N -7,10,13,16-docosatetraenylethanolamine were identified as endogenous cannabinoid ligands. A fatty acid ester, 2-arachidonoylglycerol (2-AG), and a fatty acid ...
Vien Jimmy - - 2002
1. This study investigated the effects of a number of GABA analogues on rat rho3 GABA(C) receptors expressed in Xenopus oocytes using 2-electrode voltage clamp methods. 2. The potency order of agonists was muscimol (EC(50)=1.9 +/- 0.1 microM) (+)-trans-3-aminocyclopentanecarboxylic acids ((+)-TACP; EC(50)=2.7 +/- 0.9 microM) trans-4-aminocrotonic acid (TACA; EC(50)=3.8 +/-0.3 ...
Tokumoto Mika - - 2002
One of the eukaryotic polypeptide chain elongation factors, EF-1 beta gamma delta complex, is involved in polypeptide chain elongation via the GDP/GTP exchange activity of EF-1 alpha. In the complex, EF-1 gamma has been reported to be a major substrate for maturation promoting factor (MPF). Here, we present the cloning, ...
Makabe Akira - - 2002
Regioselectively hetero-labeled hosts, 6A-pyrenebutylate-6X-tosyl-modified gamma-cyclodextrins (X = B or H, C or G, D or F, and E for gamma-1, gamma-2, gamma-3, and gamma-4, respectively), were synthesized in order to investigate their chemo-sensor properties for applications to organic compounds, such as bile acids and terpenes. The hosts (gamma-1, gamma-2, gamma-3, ...
Fraser E J - - 2002
This study investigated the effect of water temperature on the synthesis of the amino acid neurotransmitter gamma-aminobutyric acid (GABA). In goldfish, GABA stimulates the release of pituitary gonadotropin-II (GTH-II), which regulates gonadal function. Fish were maintained in water of 11, 18, or 24 degrees. In the female and male goldfish, ...
Suzuki Hideyuki - - 2002
The tastes of several bitter amino acids and their gamma-glutamyl derivatives were compared. The bitterness of Phe, Val, Leu, and His was reduced, sourness was produced, and preferences were increased by gamma-glutamylization. Because the effect of gamma-glutamylization of bitter amino acids was most obvious for Phe, which is an atypical ...
Schrott-Fischer Anneliese - - 2002
Different neuroactive substances have been found in the efferent pathways of both the olivocochlear and vestibular systems. In the present study, the distribution and role of three neurotransmitters, choline acetyltransferase (ChAT), gamma aminobutyric acid (GABA), and enkephalin were investigated in the human labyrinth of 4 normal-hearing individuals. Immunohistochemical studies in ...
Okamoto Kenji - - 2002
A wild strain of brown-rot basidiomycete Piptoporus soloniensis produced a sweet flavor similar to tropical fruits in liquid cultures. The major and minor compounds were identified to be gamma-decalactone and gamma-octanolactone by gas chromatography-mass spectrometry analysis, respectively. The growth and production of gamma-decalactone by P. soloniensis in broth to which ...
Yokoyama Sadaji - - 2002
Lactobacillus brevis IFO-12005 showed good growth in rice shochu distillery lees (kome shochu kasu). Almost all of the free glutamic acid (10.50 mM) in shochu kasu was converted to gamma-amino-butyric acid (GABA) within 2 d of stationary culture at 30 degrees C. The amount of GABA in the kome shochu ...
Crites Glenda J - - 2002
Gamma-aminobutyric acid (GABA) is the main inhibitory neurotransmitter in mammalian brain. The synaptic action of GABA is terminated by a sodium- and chloride-linked transport system. The GABA transporter is known as GAT and several isoforms have been identified. Many components of a GABA neurotransmitter system, including a GABA transport system, ...
Mizuguchi M - - 2001
Osteocalcin, the gamma-carboxyglutamic acid-containing protein, which is the most abundant noncollagenous protein of bone and dentin, is considered to play roles in bone formation and remodeling. It is unclear how the gamma-carboxyglutamic acid side-chains in osteocalcin coordinate to Ca2+, since the X-ray structure of osteocalcin is not available. Interactions between ...
Takaichi S - - 2001
We identified pigments in a thermophilic filamentous photosynthetic bacterium Roseiflexus castenholzii strain HL08. We detected neither bacteriochlorophyll (BChl) c nor carotenes in this bacterium cultured under the aerobic dark and the anaerobic light conditions, which may correspond to its lack of chlorosomes. In the cells cultured under the aerobic dark ...
Vesselkin N P - - 2001
In three frog species Rana esculenta, Rana temporaria and Xenopus laevis, the contacts established by gamma-aminobutyric acid and glutamate decarboxylase immunoreactive (-ir) terminals upon primary afferent fibers were studied using confocal and electron microscopy. For confocal microscopy, the primary afferent fibers were labeled through the dorsal root with Dextran-Texas Red, ...
Sanz M L - - 2001
The presence of Amadori compounds in commercial dehydrated fruits has been shown through HPLC analysis of the corresponding 2-furoylmethyl-amino acids obtained by acid hydrolysis. Furosine (2-furoylmethyl-lysine) was the main 2-furoylmethyl derivative observed in dried figs and apricot samples, whereas in prunes and dates similar amounts of furosine and 2-furoylmethyl-gamma-aminobutyric acid ...
Mendyk A - - 2001
The present study investigated the influence of BM-78, BM-121 (gamma-aminobutyric acid amide derivatives) and BM-42, BM-43 (phthalimide precursors of BM-78 and BM-121) on the spontaneous locomotor activity and on the picrotoxin-induced seizures. Results of pharmacological in vivo examination of the effects of new gamma-aminobutyric acid amide derivatives and its phthalimide ...
Xian M - - 2001
AIMS: To optimize the production of linolenic acid by Mortierella isabellina grown on hexadecanol. METHODS AND RESULTS: Effects of culture conditions such as culture time, pH of medium, hexadecanol concentration, incubation temperature and ageing of mycelia on production of linolenic acid were studied. The production of gamma-linolenic acid reached 2.44 ...
Duer W C - - 2001
The most common chemicals that can be ingested and lead to greater than endogenous levels of gamma-hydroxybutyric acid (GHB) in decedents are salts of GHB, gamma-butyrolactone (GBL), and 1,4-butanediol (BD). Results for three deaths involving the ingestion of one or another of these three chemicals, which led to findings of ...
Kang T C - - 2001
To identify the roles of gamma-aminobutyric acid (GABA) transporter in epileptogenesis and the recovery mechanisms in spontaneous seizure, a chronological and comparative analysis of GABA transporters (GAT) expression was conducted. GAT-1 immunoreactivity was more strongly detected in the pre-seizure group of seizure sensitive (SS) gerbils than that seen in the ...
Ferraro L - - 2001
The effect of gamma-hydroxybutyric acid on extracellular glutamate levels in the hippocampus was studied by microdialysis in freely moving rats and in isolated hippocampal synaptosomes. Intra-hippocampal (CA1) perfusion with gamma-hydroxybutyric acid (10 nM-1 mM) concentration-dependently influenced glutamate levels: gamma-hydroxybutyric acid (100 and 500 nM) increased glutamate levels; 100 and 300 ...
Hemmati P - - 2001
Recent evidence demonstrates that two subdivisions of the nucleus accumbens, the dorsolateral core and the ventromedial shell can be distinguished by morphological, immunohistochemical and chemoarchitectural differences. In the present study, we measured basal levels of amino acids in microdialysates from both the shell and core subterritories of the nucleus accumbens ...
Kim S H - - 2001
The aim of this study was to determine the effect of Panax ginseng and its fractions on jejunal crypt survival, endogenous spleen colony formation and apoptosis in jejunal crypt cells of mice irradiated with high- and low-dose of gamma-irradiation. The radioprotective effect of ginseng was compared with the effect of ...
Yang L - - 2001
The inferior colliculus (IC) is strongly implicated in seizure initiation in a genetic form of audiogenic seizures (AGS) and in AGS observed during ethanol withdrawal (ETX). Ethanol is known to block the actions of excitatory amino acids (EAA) and enhance the actions of gamma-aminobutyric acid (GABA) in several brain areas, ...
Rozan P - - 2001
The amino acid content of seeds and 4-day-old seedlings were studied in five species of lentil: Lens culinaris, L. orientalis, L. ervoides, L. nigricans and L. odemensis. Free amino acid and also total protein amino acid content after HCl hydrolysis were determined by HPLC. The nonprotein UV-absorbing amino acids were ...
Hou X - - 2001
15-F(2t)-isoprostane (15-F(2t)-IsoP), also termed 8-isoprostaglandin F(2alpha), is one of a series of prostanoids formed by free radical-mediated peroxidation of arachidonic acid and exerts potent biological actions such as vasoconstriction. We recently demonstrated that 15-F(2t)-IsoP is metabolized in humans to a major metabolite, 2,3-dinor-5,6-dihydro-15-F(2t)-IsoP (15-F(2t)-IsoP-M). 15-F(2t)-IsoP-M can also potentially be formed ...
Varju P - - 2001
In addition to being the major inhibitory neurotransmitter, gamma-aminobutyric acid (GABA) is thought to play a morphogenetic role in embryonic development. During the last decade, considerable progress has been made in elucidating the molecular mechanisms involved in GABA synthesis and biological action. The present review is an attempt to summarise ...
Valiaeva N - - 2001
Several routes to a complex phosphinate phosphapeptide analogous to the gamma-glutamyl peptide Glu-gamma-Glu have been investigated. Formation of gamma-phosphono glutamate derivatives via addition of a phosphorus-based radical to protected vinylglycine was found to be of limited value because of the elevated temperatures required. Alkylation and conjugate addition reactions of trivalent ...
Fujiyama F - - 2001
Brain-specific Na(+)-dependent inorganic phosphate cotransporter (BNPI) was recently reported to serve as a vesicular glutamate transporter (VGluT), and was renamed VGluT1 (Bellocchio et al. [ 2000] Science 289:957-960; Takamori et al. [2000] Nature 407:189-194). Ahead of these reports, cDNA encoding another brain-specific inorganic phosphate transporter, which showed 82% amino acid ...
Barrett-Jolley R - - 2001
The GABA-related compound nipecotic acid is commonly used to inhibit GABA uptake. This report shows that nipecotic acid can also directly activate GABA(A)-like chloride channels. When applied to outside-out patches of paraventricular neurones, nipecotic acid (1 mM) activated inward unitary currents (approximately 3 pA at a holding potential of -60 ...
Marianna P - - 2001
BACKGROUND AND OBJECTIVES: In addition to conventional therapy, current treatment of thalassemia and sickle cell anemia includes inducers of hemoglobin F synthesis (hydroxyurea, erythropoietin, azacytidine and butyrate). However, because of concerns about the dose-limiting myelotoxicity, potential carcinogenicity and high cost of the above agents, an intensive search for less toxic ...
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