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Pyruvic Acid (pyruvic + acid)
Selected AbstractsChemInform Abstract: Enzymatic Synthesis of Pyruvic Acid from Acetaldehyde and Carbon Dioxide.CHEMINFORM, Issue 2 2002Masaya Miyazaki Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Recovery of pyruvic acid with weakly basic polymeric sorbentsJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 5 2008Shaokai Huang Abstract BACKGROUND: Carboxylic acids are among the most important substances that can be manufactured from biomass. However, the recovery of carboxylic acids from fermentation broths presents a challenging separation problem. To avoid the production of waste salts and net consumption of chemicals in the calcium carboxylate salt process, the use of reversible chemical complexation with polymeric sorbents and extractants is attractive for carboxylic acid recovery. Pyruvic acid is widely used in the manufacture of medicines, pesticides and foodstuffs and can be produced by fermentation. Since the acidity of pyruvic acid (pKa = 2.49) is stronger than that of normal carboxylic acids, and as few reports on the recovery of pyruvic acid are available, the sorption of pyruvic acid from aqueous solution on two types of weakly basic polymeric sorbent, tertiary amine D301R and primary amine D392, was investigated over a wide pH range and at various salt (MgSO4) concentrations. RESULTS: Overloading adsorption of pyruvic acid on both weakly basic polymeric sorbents occurred, with the overloading of D392 being greater than that of D301R. The adsorption of pyruvic acid on both sorbents was greatly affected by the solution pH and the salt concentration in the aqueous phase. An overloading model was able to predict the experimental uptake data very well. CONCLUSION: Solution pH is one of the most important operating conditions, and both polymeric sorbents D392 and D301R can be used to recover pyruvic acid from dilute aqueous solution with high efficiency at a solution pH around 2. The uptake by D392 is greater than that by D301R owing to steric hindrance of the tertiary amine. Copyright © 2008 Society of Chemical Industry [source] An Efficient Synthesis of Novel Hexahydropyrido[2,3- d]pyrimidine Derivatives from (Arylmethylidene)pyruvic Acids (=(3E)-4-Aryl-2-oxobut-3-enoic Acids) in Aqueous MediaHELVETICA CHIMICA ACTA, Issue 5 2009Saeed Balalaie Abstract A series of new hexahydropyrido[2,3- d]pyrimidine derivatives 3 were synthesized by the cyclocondensation reaction of (arylmethylidene)pyruvic acids (=(3E)-4-aryl-2-oxobut-3-enoic acids) 1 and 6-aminouracils (=6-aminopyrimidine-2,4(1H,3H)-diones) 2 in H2O under reflux conditions (Scheme,1, Table). This novel protocol has the advantages of facility, of easy workup, of high yields, and of an environmentally benign procedure. The structures of compounds 3a,3f were corroborated spectroscopically (IR, 1H- and 13C-NMR, and EI-MS). A plausible mechanism for the reaction is proposed (Scheme,2). [source] Transamination by Polymeric Enzyme MimicsHELVETICA CHIMICA ACTA, Issue 11 2003Wenjun Zhou Pyridoxamine was linked to a series of polyethylenimines (PEIs) with Mn=600, 1800, 10,000, and 60,000, both simply permethylated and with additional attached dodecyl chains. They were examined in the transamination of pyruvic acid and of phenylpyruvic acid, and showed MichaelisMenten behavior. The values of k2 and of KM determined showed only small variations with polymer size. Thus, the previously reported strong advantage of pyridoxamines attached to the Mn=60,000 PEI, relative to simple pyridoxamine alone, is seen to almost the same extent with the smaller PEIs. [source] Two-step syntheses of 3-methyl and 3-phenyl-1,2,4-benzotriazinesHETEROATOM CHEMISTRY, Issue 2 2006Mohamed Khodja 3-Methyl-1,2,4-benzotriazine and some of its derivatives were prepared in moderate yields (50,70%) via a reductive cyclization by a PtO2 -catalyzed hydrogenation of the corresponding 2-nitrophenylhydrazones of the pyruvic acid. The latter compounds were obtained in yields higher than 90% by reacting 2-nitrophenylhydrazines with sodium pyruvate salt. Three 3-phenyl-1,2,4-benzotriazine compounds were also produced via a reductive cyclization by a Pt/C-catalyzed hydrogenation of their corresponding 2-nitrophenylhydrazono-ethers in high yields (>70%). © 2006 Wiley Periodicals, Inc. Heteroatom Chem 17:166,172, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20200 [source] Comparison of the characteristics of set type yoghurt made from ovine milk of different fat contentINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 9 2007Stelios Kaminarides Summary Characteristics of four types of yoghurt made from ovine milk containing 6.6%, 3.8%, 2.3%, or 0.9% fat respectively were studied. The yoghurt produced from ovine milk with high fat had the highest flavour and texture scores, fat and total solids content and firmness, but the lowest syneresis, lactic acid and galactose content. Low-fat yoghurts can be successfully produced from homogenised ovine milk and these yoghurts did not significantly differ from that of full fat yoghurt in values for ash, lactose, citric acid, pyruvic acid, pH and non-protein nitrogen. The HPLC procedure that was used for the determination of lactose was appropriate for the simultaneous determination of galactose and organic acids in milk or yoghurt. A total of sixteen volatile compounds were identified in ovine yoghurt and the main volatile flavour compounds in yoghurt on 2 days were acetic acid, acetaldehyde, acetone, diacetyl, 2-butanone, 3-hydroxy-2-butanone and 3-methyl-2-butanone. [source] Recovery of pyruvic acid with weakly basic polymeric sorbentsJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 5 2008Shaokai Huang Abstract BACKGROUND: Carboxylic acids are among the most important substances that can be manufactured from biomass. However, the recovery of carboxylic acids from fermentation broths presents a challenging separation problem. To avoid the production of waste salts and net consumption of chemicals in the calcium carboxylate salt process, the use of reversible chemical complexation with polymeric sorbents and extractants is attractive for carboxylic acid recovery. Pyruvic acid is widely used in the manufacture of medicines, pesticides and foodstuffs and can be produced by fermentation. Since the acidity of pyruvic acid (pKa = 2.49) is stronger than that of normal carboxylic acids, and as few reports on the recovery of pyruvic acid are available, the sorption of pyruvic acid from aqueous solution on two types of weakly basic polymeric sorbent, tertiary amine D301R and primary amine D392, was investigated over a wide pH range and at various salt (MgSO4) concentrations. RESULTS: Overloading adsorption of pyruvic acid on both weakly basic polymeric sorbents occurred, with the overloading of D392 being greater than that of D301R. The adsorption of pyruvic acid on both sorbents was greatly affected by the solution pH and the salt concentration in the aqueous phase. An overloading model was able to predict the experimental uptake data very well. CONCLUSION: Solution pH is one of the most important operating conditions, and both polymeric sorbents D392 and D301R can be used to recover pyruvic acid from dilute aqueous solution with high efficiency at a solution pH around 2. The uptake by D392 is greater than that by D301R owing to steric hindrance of the tertiary amine. Copyright © 2008 Society of Chemical Industry [source] Thermal deactivation and inhibition of D -Amino acid oxidase in permeabilized cells of the yeast Trigonopsis variabilisJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 4 2004José A Moreno Abstract The inhibition of D -amino acid oxidase contained in permeabilized cells of the yeast Trigonopsis variabilis by ,-keto acids (pyruvic acid, phenylpyruvic acid and 4-methylthio-2-oxobutanoic acid), products of the transformation of the corresponding D -amino acids, was studied. In all cases, inhibition was of the mixed type and significant differences with respect to the inhibition shown by the enzyme from other sources such as pig kidney or the yeast Rhodotorula gracilis were observed. A study was also made of the thermal deactivation of the enzyme contained in permeabilized cells of T variabilis in the temperature range 30,50 °C in sodium phosphate and Tris hydroxylmethyl aminomethane + CaCl2 buffers. A deactivation mechanism with two steps in series is proposed to account for the variation in activity with time. The results suggest that the enzyme shows greater stability in phosphate buffer, with half-lives between 7.6 days at 30 °C and 8.6 h at 50 °C. Copyright © 2004 Society of Chemical Industry [source] Study of factors affecting binding of zinc with albumin at physiological zinc concentrationsBIOFACTORS, Issue 3 2004V.V. Agte Abstract Albumin has very high affinity for many organic and inorganic compounds that may influence albumin bound Zn (ABZn). To get insight of these molecular interactions, the effect of riboflavin, nicotinic acid, thiamine, folic acid, pyruvic acid and glucose on ABZn were studied. The ABZn was separated from the unbound zinc using equilibrium dialysis and estimated using atomic absorption spectrometer. At therapeutic zinc concentrations, folic acid and thiamine significantly enhanced the ABZn (p < 0.010), while nicotinic acid inhibited zinc binding to albumin. Folic acid was found to enhance the ABZn also at lower zinc concentrations representing physiological levels of plasma zinc (138,150 micromoles) (p < 0.05). [source] Simultaneous clinical monitoring of lactic acid, pyruvic acid and ketone bodies in plasma as methoxime/tert-butyldimethylsilyl derivatives by gas chromatography,mass spectrometry in selected ion monitoring modeBIOMEDICAL CHROMATOGRAPHY, Issue 5 2008Man-Jeong Paik Abstract Simultaneous determination of lactic acid, pyruvic acid, 3-hydroxybutyric acid and acetoacetic acid for clinical monitoring of lactic acidosis and ketone body formation in human plasma (20 µL) was performed by gas chromatography,mass spectrometry in selected ion monitoring (SIM) mode after generating methoxime/tert-butyldimethylsilyl derivatives. All of the targeted carboxylic acids were detected by characteristic fragment ions, which permitted sensitive and selective identification in the presence of co-extracted free fatty acids and other acidic metabolites at much higher levels. The method was linear (r , 0.9991), reproducible (% relative standard deviation = 1.2,5.8), and accurate (% relative error = ,7.2,7.6), with detection limits of 0.05,1.7 ng/mL. This rapid, accurate and selective method using minimal plasma samples (20 µL) is useful in the clinical monitoring of lactic acidosis and ketone body formation in plasma. Copyright © 2008 John Wiley & Sons, Ltd. [source] Enantioselective oxidation of 2-hydroxy carboxylic acids by glycolate oxidase and catalase coexpressed in methylotrophic Pichia pastorisBIOTECHNOLOGY PROGRESS, Issue 3 2010Shuvendu Das Abstract Glycolate oxidase (GO; (S)-2-hydroxyacid oxidase, EC 1.1.3.15) is a flavin mononucleotide (FMN)-dependent enzyme, which catalyzes the oxidation of 2-hydroxy carboxylic acids to the corresponding 2-keto acids. Catalase has been used as cocatalyst to decompose hydrogen peroxide produced in the reaction, thus limiting peroxide-based side reactions and GO deactivation. GO from spinach and catalase T from Saccharomyces cerevisiae previously coexpressed in Pichia pastoris strain NRRL Y-21001, was permeabilized and used for the oxidation of 3-phenyllactic acid, 3-indolelactic acid, 3-chlorolactic acid, 2-hydroxybutanoic acid, and 2-hydroxydecanoic acid to demonstrate high degree of selectivity to the (S)-enantiomers, leaving (R)-isomers intact. The rates of oxidation ranged from 1.3 to 120.0%, relative to the oxidation of lactic acid to pyruvic acid. The best substrates were 3-chlorolactic acid (110%) and 2-hydroxybutanoic acid (120%). Oxidation was carried out with (R)-, (S)-, and (RS)-3-phenyllactic acid, (RS)-lactic acid, and (RS)-2-hydroxybutanoic acid in 500 mL scale to characterize the products and stoichiometry of the reaction. All (RS)- and (S)-2-hydroxy acids produced 2-keto acids at close to the theoretical yield in 1,9 h. (R)-3-Phenyllactic acid was not oxidized over a period of 9 h. Addition of exogenous FMN and catalase were not required for this oxidation using double recombinant Pichia pastoris whole cells. As GO is absolutely specific to (S)-enantiomers, it can be used for resolution of racemic 2-hydroxy acids to (R)-2-hydroxy acids as well as for production of 2-keto acids. This is the first report on the selectivity of a broad range of 2-hydroxy acids by GO. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2010 [source] Effect of Different Carbon Sources on the Production of Succinic Acid Using Metabolically Engineered Escherichia coliBIOTECHNOLOGY PROGRESS, Issue 2 2007Christian Andersson Succinic acid (SA) is an important platform molecule in the synthesis of a number of commodity and specialty chemicals. In the present work, dual-phase batch fermentations with the E. coli strain AFP184 were performed using a medium suited for large-scale industrial production of SA. The ability of the strain to ferment different sugars was investigated. The sugars studied were sucrose, glucose, fructose, xylose, and equal mixtures of glucose and fructose and glucose and xylose at a total initial sugar concentration of 100 g L,1. AFP184 was able to utilize all sugars and sugar combinations except sucrose for biomass generation and succinate production. For sucrose as a substrate no succinic acid was produced and none of the sucrose was metabolized. The succinic acid yield from glucose (0.83 g succinic acid per gram glucose consumed anaerobically) was higher than the yield from fructose (0.66 g g,1). When using xylose as a carbon source, a yield of 0.50 g g,1 was obtained. In the mixed-sugar fermentations no catabolite repression was detected. Mixtures of glucose and xylose resulted in higher yields (0.60 g g,1) than use of xylose alone. Fermenting glucose mixed with fructose gave a lower yield (0.58 g g,1) than fructose used as the sole carbon source. The reason is an increased pyruvate production. The pyruvate concentration decreased later in the fermentation. Final succinic acid concentrations were in the range of 25,40 g L,1. Acetic and pyruvic acid were the only other products detected and accumulated to concentrations of 2.7,6.7 and 0,2.7 g L,1. Production of succinic acid decreased when organic acid concentrations reached approximately 30 g L,1. This study demonstrates that E. coli strain AFP184 is able to produce succinic acid in a low cost medium from a variety of sugars with only small amounts of byproducts formed. [source] Hydrogen Production from Glucose by AnaerobesBIOTECHNOLOGY PROGRESS, Issue 6 2005Hiroyasu Ogino Various anaerobes were cultivated in media containing glucose. When 100 mL of thioglycollate medium containing 2.0% (w/v) glucose was used, Clostridium butyricum ATCC 859, NBRC 3315, and NBRC 13949 evolved 227,243 mL of biogas containing about 180 mL of hydrogen in 1 day. Although some strains had some resistance against oxygen, C. butyricum ATCC 859 and 860 did not have it. C.butyricum NBRC 3315 and Enterobacter aerogenes NBRC 13534 produced hydrogen in the presence of glucose or pyruvic acid, and E. aerogenes NBRC 13534 produced hydrogen by not only glucose and pyruvic acid but also dextrin, sucrose, maltose, galactose, fructose, mannose, and mannitol. When a medium containing 0.5% (w/v) yeast extract and 2.0% (w/v) glucose was used, E. aerogenes NBRC 13534 evolved more biogas and hydrogen than C. butyricum NBRC 3315 in the absence of reducing agent. [source] Utilization of an Alternative Carbon Source for Efficient Production of Human ,1 -Antitrypsin by Genetically Engineered Rice Cell CultureBIOTECHNOLOGY PROGRESS, Issue 3 2001Masaaki Terashima Human ,1 -antitrypsin was produced by genetically engineered rice cells using promoter and signal peptide of a rice ,-amylase isozyme. Batch and continuous cultures were employed to investigate the effects of alternative carbon sources on the ,1 -antitrypsin production. While this expression system is inducible by sugar depletion, we have found that the productivity of ,1 -antitrypsin increased 2.4- to 3.4-fold, compared with the control medium without carbon source, in medium containing an alternative carbon source, such as pyruvic acid and glyoxylic acid. The accumulated ,1 -antitrypsin in the medium containing pyruvic acid reached 18.2,24.2 mg/g-dry cell in 50,70 h by batch culture. [source] An Efficient Synthesis of Novel Hexahydropyrido[2,3- d]pyrimidine Derivatives from (Arylmethylidene)pyruvic Acids (=(3E)-4-Aryl-2-oxobut-3-enoic Acids) in Aqueous MediaHELVETICA CHIMICA ACTA, Issue 5 2009Saeed Balalaie Abstract A series of new hexahydropyrido[2,3- d]pyrimidine derivatives 3 were synthesized by the cyclocondensation reaction of (arylmethylidene)pyruvic acids (=(3E)-4-aryl-2-oxobut-3-enoic acids) 1 and 6-aminouracils (=6-aminopyrimidine-2,4(1H,3H)-diones) 2 in H2O under reflux conditions (Scheme,1, Table). This novel protocol has the advantages of facility, of easy workup, of high yields, and of an environmentally benign procedure. The structures of compounds 3a,3f were corroborated spectroscopically (IR, 1H- and 13C-NMR, and EI-MS). A plausible mechanism for the reaction is proposed (Scheme,2). [source] | |||||||||||||