Pyruvic acid formulations

After pyruvic acid and acetaldehyde had been identified as intermediate products of glycolysis, sugar degradation could be formulated schematically by the following equations ... 

Thus, the nonulosaminic acids were formulated as aldol condensation products of a hexosamine with pyruvic acid. This speculative concept received its first support with the isolation of A -acetyl-n-glucosamine as a degradation product of A -acetylneuraminic acid. These degradations employed nickel acetate plus pyridine or mild alkah for ten minutes. Besides A -acetyl-n-glucosamine and a number of unidentified degradation products, pyruvic acid was produced and was isolated as its (2,4-di-nitrophenyl) hydrazone. 

The conclusion was reached that the biosynthetic route was by way of a two-carbon insertion into 2-oxo-3-hydroxy-3-methylbutyric acid (CLXXIV). Taken in conjunction with the established bios3uithesis of valine (CLXXV) from pyruvic acid by way of acetyllactic acid (CLXXVI) and the ketol rearrangement to CLXXIV the biosynthesis of echimidinic acid may be formulated as in Chart VI. 

In the reactions of 2-amino-2-deoxy-D-glucose with some /3-dicarbonyl compounds (such as ethyl acetoacetate, 2,4-pentanedione, or pyruvic acid) in alkaline solution, pyrroles lacking the tetrahydroxybutyl chain are obtained. The loss of this group cannot occur with the already formed (tetrahydroxybutyl)pyrroles, because these compounds, as exemplified by 3-acetyl-2-methyl-5-(D-ora wo-tetrahydroxybutyl)pyrrole (2), remain unchanged at the pH (9-10) of the reaction. The fission of the sugar chain most probably occurs for one of the intermediates of the reaction, for instance (79), and it may be formulated as a concerted-elimination reaction catalyzed by the hydroxyl ion, as indicated in Scheme C. The... 

The initial syntheses of Cypridina luciferin and its analogues were performed in low yields by reaction of appropriate 2-aminopyrazines with a-keto acids, followed by reduction with aluminum amalgam or catalytic hydrogenation, and treatment of the product with dicyclohexyl-carbodiimide. For example, 2-amino-5-phenylpyrazine (36) on reaction with pyruvic acid gave the product 37, which was reduced to give an intermediate formulated as 38, which was then cyclized to give the 0x0 compound 39 in 7% yield. It was later discovered that these products could be obtained in high yield in one step by reaction of aminopyrazines such as 36 with a-keto aldehydes such as pyruvaldehyde (MeCOCHO). Condensation of the appropriate aminopyrazine with... 

From these studies of the concomitant organic products it is clear that the observed G(NHS) values represent the combined yield of a number of different modes of degradation of the peptide chain. And, before proceeding to detailed considerations of elementary processes, it is useful here to formulate working hypotheses as to the stoichiometry of these reactions. First of all we note that the maximal yields of lactic acid and of the carbonyl products, acetaldehyde and pyruvic acid from acetylalanine are obtained only after mild hydrolysis of the irradiated... 

De Padova MP, BeUavista S, Tosti A (2007) Peel with pyruvic acid the new formulation in gel. J Am Acad Dermatol 56(S2) AB17... 

Much work [42] has been devoted to cinchona alkaloid modified Pd and Pt catalysts in the enantioselective hydrogenation of a-keto esters such as ethyl pyruvate (Scheme 5.11). Optimal formulation and conditions include supported Pt, the inexpensive (—)-cinchonidine, acetic acid as solvent, 25 °C and 10-70 bar H2. Presently, the highest e.e. is 97.6% [to (R)-ethyl lactate]. 

With the exception of lactate and pyruvate, the differences in levels of these acids emanating from the skin of the subjects did not vary too greatly between our small groups of representatives of the different sexes. The statistical and socio-sexual significance of these results notwithstanding, the above study has demonstrated the chemical complexity of cutaneous emissions even prior to the application of natural or artificially formulated scents and fragrances. 

PG, similar to glycerin, is a multifunctional excipient that can be an effective preservative when used at concentrations of 15% to 30% in oral solutions. However, formulations containing 35% PG can cause hemolysis in humans. PG exhibits nonlinear pharmacokinetics and when elimination pathways are saturated, serum levels dramatically increase. Pyruvic and lactic acid are produced from the metabolic degradation of PG and can lead to acidosis. Neonates have a longer PG half-life (16.9 hours) compared with adults (5 hours) and seizures, and respiratory depression has occurred in children who have ingested oral liquid medications containing PG (9). Therefore, special consideration should be placed on the amount of PG in formulations that are intended for infants and children. 

Hydroxyglutaric acid forms a ternary anionic complex with Fe and The complexes TiCl2L2 (L = ethyl-4-nitrobenzoylpyruvate, ethyl-4-phenylbenzoyl-pyruvate, ethyl-2,4-dimethoxybenzoylpyruvate, or ethyl-2-naphthylpyruvate) have been prepared.There has been a spectroscopic study of complex formation in the Ti -salicylate-aa-bipyridyl system,and a reinvestigation of the reaction between Ti and salicylic acid in concentrated sulphuric acid. The coloured TiO salicylic acid complex formed in the latter system is formulated as a 7t-compIex rather than a chelate. 

It is well known that in the oxidation of pyruvate an active 2-carbon intermediate, known as active acetate, is formed (Gurin and Crandall, 1948 Bloch, 1948 Lehninger, 1950). A suggestion that pantothenic acid is involved in the conversion of acetate to citrate in yeast came from Novelli and Lipmann s (1950) experiments showing a correlation between the ability of the yeast to oxidize acetate or ethanol and the coenzyme A content of the cells. The formation of citrate from acetate and oxaloacetate in cell-free extracts from pigeon liver or yeast was also shown to require coenzyme A (Novelli and Lipmann, 1950 Stern and Ochoa, 1949, 1951). Further study of these enzyme systems led to the isolation of a crystalline condensing enzyme from pig heart (Ochoa et al., 1951) and to a formulation of the mechanism of the enzymatic synthesis of citric acid from... 

We previously reported the complete transformation of brushite (DCPD, dicalcium phosphate dihydrate, CaHP04-2H20) powders in less than a week to octacalcium phosphate (OCP), but not to apatitic calcium phosphate, when a commercial DMEM solution was used as the soak test medium at 37°C [42]. The removal of all the amino acids, vitamins, ucose/dextrose, phenol red, Hepes and pyruvate from the DMEM formulation and raising the Ca/P molar ratio of thus modified form of biomineralization solution from 1.99 to 2.50 led to observing much faster transformation of DCPD powders to OCP in comparison to DMEM [43]. 

S) Amino Acid Amide Transaminases. Mention was made previously (see Amidases) of the observations by Greenstein and co-workers that the addition of pyruvic and other a-keto acids to liver extracts accelerated the formation of ammonia from glutamine and asparagine. This reaction has been shown by Meister and co-workers to involve a transamination reaction different in several respects from those previously discussed. The reaction for glutamine may be formulated as follows ... 

According to the authors the formulation shown in Fig. 4A requires that the carboxylate ion be bound to the enzyme so that complete randomization between all three carbons is prohibited. In the above scheme randomization between the a- and 8-carbons would be complete with propionate where racemization is obligatory. In the case of lactate, however, use of the DL-substrate would only result in a partial randomization since the withdrawal of the D-isomer via pyruvate and the citric acid cycle would compete with the route leading to its inversion. 

As can be expected, many aspects of the citric acid chemistry are linked with chemical analysis of citric acid or citrates in biological materials [169, 172, 179, 326-328], in fermentation media [179, 188, 192, 329-333], in foods [155, 334-340], in fraits [165, 177, 341-347], in tomato-based products [348-350], in musts, wines and beers [155, 174, 351-363], in soft drinks and fruit juices [155, 165, 177, 361, 364-377], in milk and dairy products [155,170,173,176,378-386], in honey [387, 388], in pharmaceutical formulations [361, 389-391], in medical tests (blood, se-ram, mine, pancreatic juice and other physiological flttids) [162, 183, 187, 193-195,392-400], and in mixtures with other caiboxyhc acids (formic, acetic, tartaric, malic, oxalic, isocitric, succinic, lactic, pyruvic, oxalacetic and others) [160, 184, 211,265,401-409]. 

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