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Results for “Pyruvic Acid”

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At least 1,135 records · Page 63Linked to original sources
PubMed2006

Composition of beer by 1H NMR spectroscopy: effects of brewing site and date of production.

A principal component analysis (PCA) of 1H NMR spectra of beers differing in production site (A, B, C) and date is described, to obtain information about composition variability. First, lactic and pyruvic acids contents were found to vary significantly between production sites, good reproducibility between dates being found for site A but not for sites B and C beers. Second, site B beers were clearly distinguished by the predominance of linear dextrins, while A and C beers were richer in branched dextrins. Carbohydrate reproducibility between dates is poorer for site C with dextrin branching degree varying significantly. Finally, all production sites were successfully distinguished by their contents in adenosine/inosine, uridine, tyrosine/tyrosol, and 2-phenylethanol, reproducibility between dates being again poorer for site C. Interpretation of the above compositional differences is discussed in terms of the biochemistry taking place during brewing, and possible applications of the method in brewing process control are envisaged.

Adenosine↗
PubMed1981

The role of glycolysis in aflatoxin biosynthesis.

In resting mycelia of Aspergillus parasiticus NRRL 3240, all the glycolytic intermediates with the exception of glucose and phosphoenolpyruvate stimulated the de novo synthesis of aflatoxin from exogenous acetate. Intracellular levels of glycolytic intermediates were measured in the toxigenic strain, A. parasiticus NRRL 3240, and the nontoxigenic strain, A. flavus NRRL 3537. In 48-h cultures, the concentrations of the intermediates beyond the phosphofructokinase reaction were higher in toxigenic mycelial extracts than in nontoxigenic cultures. There was a marked reduction in the specific activity of phosphofructokinase with increasing age in the toxigenic strain. The specific activity of this enzyme was two- to four-fold lower in zinc-deficient mycelia of A. parasiticus. In resting cultures, the uptake rate of labeled glucose was considerably lower in zinc-deficient mycelia than in zinc-replete or nontoxigenic cultures. On the basis of the results obtained, it can be said that intense formation of aflatoxin is associated with a sharp fall in the level of phosphoenolpyruvic and pyruvic acids. This was accompanied by a significantly higher pyruvate kinase activity.

Aflatoxins↗
PubMed1982

Elevation of serum angiotensin-converting enzyme activity in patients with hyperthyroidism.

The activity of serum angiotensin-converting enzyme (S-ACE) was determined spectrophotometrically in 45 patients with hyperthyroidism (30 untreated and 15 treated and euthyroid patients), 14 patients with hypothyroidism, and 135 normotensive healthy subjects. S-ACE was significantly higher in the patients with untreated hyperthyroidism (51.6 +/- 1.9 less than SE greater than nmol.min/ml) than in the healthy controls (28.6 +/- 0.6 nmol.min/ml; P less than 0.001). On the other hand, S-ACE was found to be within the normal range in patients with hypothyroidism (23.2 +/- 1.3 nmol.min/ml). In patients with hyperthyroidism, S-ACE gradually fell into the normal range as the thyroid function became normalized, and there were significant positive correlations between S-ACE and the plasma T3 or T4 concentration (r = 0.60 and P less than 0.001; r = 0.61 and P less than 0.001, respectively ). S-ACE had no definite relation to blood pressure, serum glutamic oxaloacetic acid transaminase, or glutamic pyruvic acid transaminase. When the physicochemical characteristics of the enzyme in the sera of hyperthyroidism patients were compared with those in sarcoidosis patients, similar peak activities of S-ACE on gel chromatography and identical Michaelis constants were obtained; the effects of ethyldiaminetetraacetic acid, SQ14225, and pH on the enzymatic reaction were also similar in both diseases. Thus, hyperthyroidism is considered to be one of the diseases in which S-ACE is elevated. The elevation of S-ACE might be directly or indirectly related to the hyperthyroid state. In addition, it is suggested that the enzyme characteristics are identical in hyperthyroidism and sarcoidosis.

Adolescent↗
PubMed1991

Metabolic fates of L-tryptophan in Saccharomyces uvarum (Saccharomyces carlsbergensis).

The metabolism of L-tryptophan by Saccharomyces uvarum (carlsbergensis) was investigated by simultaneous measuring of fluxes through kynureninase, through transaminases and into protein using L-[methylene-14C] and L-[side chain-2,3-3H]tryptophan. In yeasts cultivated in synthetic medium (S medium), the flux into protein was predominant, closely followed by the flux leading to 2-3H liberation. The proportion of L-tryptophan metabolized via the latter flux increased over 10-fold (75% of total tryptophan metabolized) as the concentration of L-tryptophan was raised from 5 x 10(-5) to 5 x 10(-4) M. L-Tryptophan metabolized via the kynureninase flux was less than 5% of total tryptophan metabolized. In yeast extract-polypepton-glucose medium (YPG medium), more tryptophan was incorporated into protein than in the S medium. Contribution of the kynureninase flux remained very low. Tryptophan metabolism via each flux changed depending on the growth phase. 2-3H liberation was shown to be primarily due to tryptophol synthesis by high performance liquid chromatography (HPLC) and nuclear magnetic resonance (NMR), indole-3-acetic acid and kynurenic acid also contributing to 2-3H liberation but to a much lesser extent. 2-3H liberation increased dose-dependently at tryptophan concentration higher than 10(-5)M, while the kynureninase flux reached its plateau at 10(-5)M. Formation of tryptophol and indole-3-acetic acid via indole-3-pyruvic acid and indole-3-acetaldehyde with indole aldehyde as a by-product was confirmed using exogenous tryptophan metabolites with indole rings.

Biotransformation↗
PubMedDate not supplied

[Clinical classification of iron deficiency anemia].

Symptoms have been analyzed of clinical pleomorphism of iron deficiency anemia (IDA). In the examination of 89 patients with IDA, as example, a complex of secondary abnormalities of metabolism accompanying IDA clinical course is demonstrated. Based on the study of aspects of the clinical course, features of the peripheral blood, indices for iron metabolism, measuring of the blood content of lactic, pyruvic acids, free histamine, free serotonin, free heparin in the blood plasma a clinical classification has been elaborated detailing stages of the condition, basic clinical forms and complications. A classification of IDA is presented. Included in the above classification are stages of the above medical condition, its clinical forms and complications with diagnostic criteria and policy of dealing with IDA outlined. The use of such a classification ensures continuity of work among physicians when they come to deal with problems of diagnosis, treatment and prophylaxis of IDA in patients.

Adult↗
PubMed2003

[Quantitation & optimization of guanosine fermentation process: prevention of NH4+ accumulation increases guanosine production by 70%].

Metabolic engineering has become a powerful tool for optimization of industrial fermentation processes. Metabolic engineering usually undergoes three steps: construction of a recombinant strain with improved properties, genetic and biochemical analysis of the strain, and identification of target for further improvement. Metabolic fluxes analysis is an important part of the biochemical analysis. Based on the law of mass conservation and assuming pseudo-steady-state for the intermediates in the metabolic pathways, we have quantitatively analyzed the time course of the flux distribution in Bacillus subtilis and used the data to reveal the nature of the so-called "40 hour" phenomenon in fermentation of guanosine, a key raw material for the synthesis of additives for human consumption and animal feeds. The phenomenon refers to the observation that guanosine production, which proceeds at high rate from 12 hour on, declines around 40 hour while consumption of glucose keeps increasing, leading to the lower yield of the nucleoside. Equations based upon the metabolic network of Bacillus subtilis consisted of EMP pathway, HMP pathway, TCA cycle, oxidative phosphorylation pathway and others reactions of the intermediates, was constructed. The equations were solved by using the quantitative data obtained in this study. The air flow and volume, concentration of oxygen and carbon dioxide in the exit-gas were monitored online; the concentration of biomass, glucose and guanosine was analyzed manually; and the concentration of acetate, citric acid, pyruvate, and 17 amino acids were HPLC quantified. The solutions of the equation were proved to be valid, as the experimental data on oxygen consumption agrees with that of predicted form the equation. The results indicated that at 40h of the fermentation process the flux of HMP pathway, which provides the precursor of the nucleoside, decreased while that of EMP pathway and the pathways that generate amino acids and organic acids increased. The shift correlated with the accumulation of NH4+ in the broth. The assimilation of NH4+ is an energy consuming process and could shift the metabolism to the energy generating EMP pathway. Accordingly, measures were taken to prevent the accumulation of NH4+. The interference indeed stopped the metabolism shift and boosted the guanosine production at 30 g/L, 70% higher than the level reported in literature.

Bacillus subtilis↗
PubMed1990

[Studies on the mechanism of ginseng polypeptide induced hypoglycemia].

When ginseng polypeptide (GP) was administered iv or sc to mice or rats, the blood sugar and liver glycogen were decreased. The decrease of blood sugar and liver glycogen induced by GP in rats were inhibited by pretreatments with pentolamine and propranolol, respectively. The results suggest that the effect of GP on glucose metabolism may be related to adrenergic receptors. In addition, GP at doses which cause decreases of blood sugar and glycogen, inhibited LDH activity, and consequently produced decrease of lactic acid and increase of pyruvic acid. GP was also found to stimulate SDH and CCO activities (which are respiratory enzymes in the electron transport chain), consequently promote aerobic oxidation course.

Animals↗
PubMedDate not supplied

[The mechanism of the antihypoxic action of indomethacin, voltaren and ibuprofen].

The antihypoxic effects of indomethacin, voltaren and ibuprofen were studied experimentally by the parameters of acid-base equilibrium of the blood and the ratio of lactic and pyruvic acids in the blood during chronic hemic and respiratory hypoxia. The results of the studies suggested that indomethacin, voltaren and to a lesser extent ibuprofen in the tested doses (10% LD50) exerted the antihypoxic action that consisted in the improvement of oxygen supply to tissues under conditions of its deficiency, the decrease of incompletely oxidized products of metabolism, the enhancement of hemoglobin synthesis and the ability of voltaren to influence the increase of the number of erythrocytes in the peripheral blood.

Acid-Base Equilibrium↗
PubMedDate not supplied

[Effect of a therapeutic and prophylactic diet enriched with thiamine and calcium pantothenate on the acetylating capacity of the body of workers engaged in the manufacture of phenol-formaldehyde resins].

The present investigation uncovered certain changes in the intensity of the acetylating processes, in the blood and urine levels of the pyruvic acid and in the urinary excretion of thiamine in a number of persons engaged in the production of phenol-formaldehyde resins. An enrichment of medico-prophylactic ration No 4 with thiamine and calcium pantothenate led to normalization of the study characteristics. The results thus made available bear proof to the prophylactic effectiveness of a supplementary vitaminization of the special diet accorded to workers handling phenol-formaldehyde resins.

Acetylation↗