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PubMed1983

Catecholamine-derived tetrahydroisoquinolines: O-methylation patterns and regional brain distribution following intraventricular administration in rats.

The metabolism of 6,7-dihydroxy (catecholic)-1,2,3,4-tetrahydroisoquinolines (TIQs) is of interest because the heterocyclic substances may form in mammals normally or during certain disease via condensations of catecholamines (CAs) with aldehydes or alpha-keto acids. With a specific capillary gas chromatography procedure and confirmatory liquid chromatographic assays, we have determined the structural isomers and relative amounts of mono-O-methylated (phenolic) TIQ metabolites in several rat brain regions 40 min following the acute intracerebroventricular injection of four structurally related catecholic TIQs. In sharp contrast with the established selective m-O-methylation of dopamine (DA) by catechol-O-methyltransferase in brain, the two simple TIQs derived from DA produced predominantly or even exclusively the metabolic isomer arising from methylation of the original p-hydroxyl group (7-O-methylation). In three catecholaminergic brain regions examined, the 7-O-methyl isomer was the only detectable phenolic metabolite of (+/-) salsolinol-1-carboxylic acid (a condensation product of DA and pyruvic acid) and, as first noted by Bail et al. (1980), constituted 95% of the two possible isomeric mono-O-methyl metabolites of (+/-) salsolinol (TIQ derivative of DA and acetaldehyde). Though less, the 7-O-methyl isomers still were a significant proportion (40-55%) of the two mono-O-methylated metabolites of (+/-) 4-hydroxy-desmethylsalsolinol (a TIQ derived from norepinephrine and formaldehyde), or of the DOPA/acetaldehyde-derived TIQ, (cis) salsolinol-3-carboxylic acid. In the time frame of the study, all four administered TIQs showed higher levels in hypothalamus than in striatum or hippocampus, with the two carboxylated alkaloids displaying the greatest differences.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1976

Symbiotic association of Photobacterium fischeri with the marine luminous fish Monocentris japonica; a model of symbiosis based on bacterial studies.

Isolation of bacteria from the luminous organ of the fish Monocentris japonica has revealed that the organ contains a pure culture of luminous bacteria. For the four fish examined, all contained Photobacterium fischeri as their luminous bacterial symbiont. This is the first time that P. fischeri has been identified in a symbiotic association. A representative isolate (MJl) of the light organ population was selected for in vivo studies of its luminous system. Several physiological features suggest adaptation for symbiotic existence. First, MJl has been shown to produce and respond to an inducer of luciferase that could accumulate in the light organ. Secondly, the specific activity of light production was seen to be maximal under low, growth-limiting concentrations of oxygen. Thirdly, unlike another luminous species (Beneckea harveyi), synthesis of the light production system of these bacteria is not catabolite repressed by glucose--a possible source of nutrition in the light organ. Fourthly, when grown aerobically on glucose these bacteria excrete pyruvic acid into the medium. This production of pyruvate is a major process, accounting for 30-40% of the glucose utilized and may serve as a form of regulatory and nutritional communication with the host.

Animals↗
PubMed1977

Introductory studies on metabolism of free glucose in aqueous extracts from smooth muscles of the stomach of geese and ducks.

Aqueous extracts from smooth muscles of the stomachs of geese and ducks contain enzyme systems which not only oxidize free D-glucose, but also determine its further metabolism. The successive metabolites are probably 1,5-D-gluconolactone and 2-ketogluconic acid, and the final product is either pyruvic acid of alpha-ketoglutaric acid. Better understanding of this metabolism will require further studies.

Acid Phosphatase↗
PubMed1989

In vitro effects of gossypol and lactic acid on rat uterus and ovary during implantation and antiimplantation.

ATPase activity of uterus and ovary was markedly elevated in presence of gossypol and decreased in presence of lactic acid indicating activation and inhibition of energy metabolism by gossypol and lactic acid respectively. The elevated levels of glycogen in uterus indicate inhibition of glycogenolysis as supported by phosphorylase activity. Whereas in ovary the glycogen depletion indicates activation of glycogenolysis supported by phosphorylase activity. The activity levels of aldolase and G-6-PDH decreased in the uterus in presence of gossypol and increased in presence of lactic acid. The same were elevated in ovary indicating the activation of hexose mono and diphosphate pathways. Lactic acid accumulated in presence of both gossypol and lactic acid with a depletion in level of pyruvic acid in both the tissues. This situation in the uterus indicates the condition of anti-implantation in presence of both gossypol and lactic acid. The NAD-LDH activity was inhibited in presence of gossypol and activated in presence of lactic acid in both tissues.

Animals↗
PubMedDate not supplied

Studies in the rabbit on 3-methyltriazolophthalazine, an acetylated metabolite of hydralazine. Evidence for an alternative route of formation.

The formation and disposition of 3-methyltriazolophthalazine (MTP), an acetylated metabolite of hydralazine (H) was studied in rabbits. Following its iv administration MTP was rapidly and almost completely metabolized. The major metabolite in plasma and urine was found to be a hitherto unrecognized glucuronide conjugate, most likely of the carboxylic acid analogue of MTP. The hydralazine-pyruvic acid hydrazone (HPH), which is a major plasma metabolite of H, was recognized as a more potent source for MPT in vivo than was parent H. MTP was also formed in significant amounts in vitro following incubation of HPH in phosphate buffer. We conclude that MTP can arise directly from HPH. Consequently, MTP and the compounds formed during its further biotransformation may not provide any valid measure of the extent to which H is acetylated in vivo.

Animals↗
PubMed2003

A new class of blue anthocyanin-derived pigments isolated from red wines.

Two newly formed anthocyanin-derived pigments that revealed unique spectroscopic features, showing maximum absorption in their UV-vis spectra at 575 nm, were isolated by TSK Toyopearl HW-40 (S) gel column chromatography and semipreparative HPLC from an aged Port red wine. Further characterization by ESI/MS and NMR ((1)H, gCOSY) showed them to belong to a new class of pigments described here for the first time, the structure of which consisted of a pyranoanthocyanin moiety linked to a flavanol by a vinyl bridge. The extended conjugation of the pi electrons throughout all the pigment molecule is likely to confer a higher stability on it and is probably the origin of the intense blue color. The formation of these pigments was found to arise from the reaction between anthocyanin-pyruvic acid adducts and vinyl-flavanol adducts.

Anthocyanins↗
PubMed1989

Stimulatory effect of calcitonin on bone formation in tissue culture.

The present investigation was undertaken to clarify the in vitro effect of synthetic [Asu1,7]eel calcitonin (CT) on bone metabolism in tissue culture. Calvaria were removed from weanling rats (3-week-old male) and cultured for periods up to 96 h in Dulbecco's Modified Eagle Medium supplemented with antibiotics and bovine serum albumin. The experimental cultures contained 1.0 to 100 ng/ml CT. All cultures were incubated at 37 degrees C in 5% CO2-95% air. Bone calcium content was increased significantly by the presence of 10 and 100 ng/ml CT. This increase was blocked by the presence of 10(-6) M cycloheximide or 10(-7) M actinomycin D. Bone alkaline phosphatase activity was significantly increased by the presence of 100 ng/ml CT for 48 and 96 h. Bone acid phosphatase activity was not altered significantly by CT (1-100 ng/ml). The incorporation of [3H]proline into the acid-insoluble residues of bone tissue was significantly increased by the presence of CT (1-100 ng/ml) for 96 h. This increase was completely blocked by the presence of 10(-7) M cycloheximide. Bone DNA content was significantly raised by the presence of 10 and 100 ng/ml CT for 96 h. Furthermore, the culture with CT (10 and 100 ng/ml) produced a significant decrease in glucose concentration in the medium. Also, CT (10 and 100 ng/ml) stimulated the production of pyruvic acid from bone tissue. These results suggest that CT had a direct stimulatory effect on bone formation and mineralization in vitro, and that the hormone stimulates energy metabolism in bone cells.

Animals↗
PubMed2002

Yeast-mediated preparation of l-PAC in an organic solvent.

The yeast-mediated acyloin condensation of benzaldehyde and pyruvic acid to form l-PAC occurs in a petroleum spirit solvent system at room temperature with moderate conversion (30%) and high enantioselectivity (86%ee) after 24 h. The addition of a small amount of ethanol (0.5% mL) to the reaction mixture inhibits the formation of the side product benzyl alcohol and increases the conversion to l-PAC. Conducting the reaction using 13C labeled pyruvate indicated that the pyruvate was incorporated into the l-PAC and that the excess pyruvate was converted into ethanol. Conducting the reaction at 5 degrees C results in similar conversion but higher enantioselectivity.

Acetone↗
PubMed2006

Pyruvate is an endogenous anti-inflammatory and anti-oxidant molecule.

Pyruvic acid, an intermediate metabolite of glucose, an effective scavenger of reactive oxygen species (ROS), inhibits tumor necrosis factor-alpha production and NF-kappaB signaling pathways, reduces circulating levels of HMGB1 (high mobility group B1), decreases COX-2 (cyclo-oxygenase-2), iNOS (inducible nitric oxide synthase), and IL-6 (interleukin-6) mRNA expression in liver, ileal mucosa, and colonic mucosa in animal models with endotoxemia. These studies suggest that pyruvate has potent anti-oxidant and anti-inflammatory actions. Insulin influences the production of pyruvate by its action on glucose metabolism and pyruvate is an insulin secretagogue. This suggests that in metabolic syndrome X, obesity, hypertension, diabetes mellitus, and cancer (where insulin resistance is common due to enhanced TNF-alpha production) pyruvate plays a role. This may have relevance to the use of glucose-insulin-potassium regimen in these clinical conditions, sepsis, and cancer.

Animals↗
PubMed1975

Amino acid biosynthesis in mixed rumen cultures.

Mixed rumen micro-organisms, maintained in continuous culture readily incorporated labelled HCO3- and acetate into amino acids. Labelled propionate, in contrast, was utilized only for isoleucine biosynthesis, but failed to label other amino acids to any significant extent. Evidence was obtained showing that in these mixed, i.e. symbiotic, cultures foward tricarboxylic acid-cycle reactions only proceed to 2-oxoglutarate. 14C distribution in amino acids clearly shows that 2-oxoglutarate is not oxidized further by tricarboxylic acid-cycle enzymes. Instead, acetate is carboxylated to pyruvate which is then carboxylated to oxaloacetate. Oxaloacetate equilibrates with fumarate and thereby carbon atoms 1 and 4 as well as carbon atoms 2 and 3 are randomized. Evidence was also obtained for the carboxylation of propionate to 2-oxobutyrate, isovalerate to 4-methyl-2-oxopentanoate, phenylacetate and hydroxyphentlacetate to the corresponding phenyl- and hydroxyphenyl-pyruvic acids and succinate to 2-oxoglutarate. Of the amino acid precursors investigated, only 3-hydroxypyruvate, the precursor of serine, appeared to be synthesized via an oxidative step, i.e. 3-phosphoglyceric acid to 3-phosphohydroxypyruvic acid. Most 2-oxo precursors of amino acids in these organisms appear to be formed via reductive carboxylation of the precursor acid.

Alanine↗
PubMed1962

Cell division in a species of Erwinia IV. Metabolic blocks in panothenate biosynthesis and their relationship to inhibition of cell division.

Grula, Mary M. (Oklahoma State University, Stillwater) and E. A. Grula. Cell division in a species of Erwinia. IV. Metabolic blocks in pantothenate biosynthesis and their relationship to inhibition of cell division. J. Bacteriol. 83:989-997. 1962.-Four compounds that inhibit cell division in an Erwinia sp., d-serine, d-histidine, d-phenylalanine, and penicillin, decrease the intracellular pantothenate content of Erwinia at culture ages of 10 and 16 hr. In the case of penicillin, it appears to be the result of excessive leakage from long cells; however, with the three d-amino acids, there is a genuine inhibition of synthesis. Among agents tested that reverse the inhibition of division, only pantoyl lactone, and to a lesser extent, omega-methylpantoyl lactone, restore intracellular content of pantothenate. This restoration is considerably less effective with d-serine as a division-inhibiting agent than with the others. Other lactones, l-alpha-alanine, and ammonium chloride are ineffective, or only slightly effective, in restoring pantothenate synthesis. Effects of division-inhibiting compounds and reversing agents upon cellular coenzyme A activity in general parallel their effects on pantothenate synthesis. There is no direct correlation between ability of a compound to reverse cell-division inhibition and ability to restore synthesis of either pantothenic acid or coenzyme A. Evidence is presented that d-serine interferes with the utilization of aspartic acid and also blocks synthesis of pantoic acid. Compounds (including glucose) which tend to produce long cells result in the accumulation of pyruvic acid in the growth medium. Pantoic acid reduces, and pantoyl lactone abolishes completely, this accumulation of pyruvate. Other reversing agents do not abolish the pyruvate accumulation.

Amino Acids↗
PubMed1977

[Analysis of the effect of bicarbonate on taste receptor sensitivity to organic acids].

Addition of NaHCO3 or NaOH to the solutions of lactic or pyruvic acids decreased threshold concentrations of H+ ions and increased intensity of afferent impulsation in the cat chroda tympani nerve. In spite of the fact that the concentrations of both lactate and pyruvate anions with the presence of NaOH and NaHCO3 are the same at equal pH values the observed changes of the receptors responses were more intensive if NaHCO3 had been added. Therefore the influence of NaHCO3 on the perception of organic acids depends not only on its buffer properties but, probably, on direct action of CO2 appearing as the result of interaction of NaHCO3 and acids, as well. This assumption was confirmed by the data on high sensitivity of the cat tongue receptors for the carbon dioxide.

Animals↗
PubMed1994

The structure of the polysaccharide produced by Proteus vulgaris (ATCC 49990).

An exocellular polysaccharide produced by a clinical isolate of Proteus vulgaris (ATCC 49990) was shown by composition, methylation, periodate oxidation, and nuclear magnetic resonance analyses to be composed of repeating trisaccharide units containing D-galactose, 2-acetamido-2-deoxy-D-glucose and pyruvic acid (2:1:1), and having the structure: [formula: see text] The homologus smooth lipopolysaccharide of the P. vulgaris strain was determined to have an O-polysaccharide component having the same structure as the above extracellular polysaccharide.

Acetylglucosamine↗
PubMed2006

Outside-in trimming of humic substances during ozonation in a membrane contactor.

This paper addresses the change of molecular size distribution of humic substances (HS) during ozonation in a membrane contactor. It focuses on the characterization and identification of some small ozonation products. The membrane contactor setup allows very precise control of ozone transfer into the solution as well as precise sampling of the products in time. The molecular size distribution was followed by gel permeation chromatography (GPC). Characterization and identification of small ozonation products was performed by membrane nanofiltration and high-performance liquid chromatography (HPLC). Measurements on molecular size distribution indicate that during the ozonation process the size of the HS molecules decreases slowly and only small highly oxidated compounds are being split off the larger molecules. Pyruvic acid, formic acid, methylglyoxal, and acetaldehyde could be identified by substantial peaks. Glyoxilic acid and glyoxal were identified to a lesser extent. This suggests that HS molecules consist of a relatively stable backbone network structure and that the HS molecule degrades according to an outside-in trimming mechanism.

Acetaldehyde↗
PubMed2000

Primordial carbonylated iron-sulfur compounds and the synthesis of pyruvate.

Experiments exploring the potential catalytic role of iron sulfide at 250 degrees C and elevated pressures (50, 100, and 200 megapascals) revealed a facile, pressure-enhanced synthesis of organometallic phases formed through the reaction of alkyl thiols and carbon monoxide with iron sulfide. A suite of organometallic compounds were characterized with ultraviolet-visible and Raman spectroscopy. The natural synthesis of such compounds is anticipated in present-day and ancient environments wherever reduced hydrothermal fluids pass through iron sulfide-containing crust. Here, pyruvic acid was synthesized in the presence of such organometallic phases. These compounds could have provided the prebiotic Earth with critical biochemical functionality.

Carbon Monoxide↗
PubMed2005

[Use of lozartan in patients with chronic cor pulmonale].

The purpose of the study was to determine the effect of the angiotensin receptor blocker lozartan on clinical manifestations, gas transport, and metabolism in blood cells in patients with chronic cor pulmonale (CCP). The subjects were 53 patients with chronic obstructive bronchitis (COB) and secondary functional claa III pulmonary hypertension. Use of lozartan in complex therapy of these patients led to increase of pyruvic acid content in erythrocytes and glucose-6-phosphatdehydrogenase activity, which suggests that lozartan stimulates redox processes in blood cells. This significantly improves metabolic provision of erythrocyte functioning, phagocytosis and immunogenesis, and leads to favorable clinical effect in patients with COB and CCP.

Adult↗
PubMed1994

Studies on the extracellular polysaccharide from Agrobacterium radiobacter biovar I S-1231.

A strain S-1231 isolated from specimen of soil around Beijing area is gram-negative, non-sporing, motile by peritrichous flagella. It produces exopolysaccharide succinoglycan from carbohydrates as its carbon source but not starch and cellulose. Acid is produced during fermentation of glucose. Growing for 12-24 hr, the cells are rods 0.7-0.8 x 1.3-1.5 microns, round ended, single or in pairs. Colonies on nutrient agar plate are unpigmented, circular, raised, smooth and moist-glistening, edge entire. The organism produces 3-ketolactose and is unable to invade sunflower tissue. The G+C content of DNA is 62.8-63.4 mol%. The organism is referred to as Agrobacterium radiobacter. Moreover, the strain is oxidase-positive, catalase-positive, H2S-produce and can grow at 35 degrees C and 2% NaCl also. Litmus milk is alkalified. Thus, the organism was renamed Agrobacterium radiobacter biovar I. Component analyses showed that the exopolysaccharide (Agran-S) from A. radiobacter biovar I S-1231 consisted of D-glucose (69.1%), D-galactose (8.6%), pyruvic acid (9.5%) and succinic acid (10.5%). Methylation analyses revealed that the polysaccharide Agran-S contained following main structural units: (1-->3)-linked D-glucose (21.2%), (1-->3)-linked D-galactose (11.4%), (1-->6)-linked D-glucose (10.5%), (1-->4)-linked D-glucose (30.4%), (1-->4, 1-->6)-linked D-glucose (22.2%) and terminal D-glucose (4.3%). The -1H-NMR spectrum of the polysaccharide indicated that the linkages in the polymer are all beta-glycosidic. The IR spectra of the polysaccharide revealed the presence of ester linkage in polysaccharide Agran-S.

Bacterial Typing Techniques↗