In the preceding paper (I), evidence concerning the proof of structure of 2-keto-3-deoxyheptonic acid was presented and it was indicated that this compound is a major product of ribose 5-phosphate metabolism in extracts of Escherichia coli strain B. This report is concerned with the enzymic synthesis of 2-keto-3deosyheptonic acid in extracts of Escherichia coli strain B and is the first direct ...

Rat liver glutamine transaminase acts on y-glutamyl hydrazones of a-keto acids to yield the corresponding L-amino acids and 3-hydroxy-tetrahydro-6-pyridazinone-3-carboxyllc acid; the latter compound undergoes nonenzymatic dehydration in acid to yield 1,4,5,6-tetrahydro-6-pyridazinone -3carboxylic acid. L-Amino acid oxidase (snake venom) also catalyzes the formation of 3-hydroxy-tetrahydro-6-pyr...

The oxidation of a stoichiometric diethyl ether-oxygen-nitrogen mixture containing 5000 ppm fuel was studied in jet-stirred reactor at 10 atm and residence times 1 s. Experimental temperatures varied stepwise for 440 to 740 K products were quantified by gas chromatography with TCD FID, chromatography-mass spectrometry, FTIR. Other experiments the temperature range 480 570 performed characterizi...

palladium (ii) coordination complexes catalyze the reaction of alcohols with ketones to yield ethers. during the catalytic cycle, the alcohol adds selectively to the β-carbon (anti-markovnikov). in this work, mechanism and kinetics for the reaction of methanol with methyl vinyl ketone (mvk), being catalyzed by pd, has been theoretically investigated in detail. using quantum mechanical approach,...

Extensive ab initio surface-hopping dynamics simulations have been used to explore the excited-state nonadiabatic decay of two biologically relevant hypoxanthine keto-N7H and keto-N9H tautomers in aqueous solution. QM/MM calculations and QM/MM-based MD simulations predict different hydrogen bonding networks around these nucleobase analogues, which influence their photodynamical properties remar...

BACKGROUND The D-galacturonic acid derived from plant pectin can be converted into a variety of other chemicals which have potential use as chelators, clarifiers, preservatives and plastic precursors. Among these is the deoxy-keto acid derived from L-galactonic acid, keto-deoxy-L-galactonic acid or 3-deoxy-L-threo-hex-2-ulosonic acid. The keto-deoxy sugars have been found to be useful precursor...

Hepatic metabolism of prostacydin (PGI,) results in the formation of several biologically inactive lipids and one stable product that has the same chromatographic and biological properties as authentic 6-keto PGE,. Both prostaglandins, 6-keto PGE, and PGI2, hare comparable potency in their antiaggregatory and disaggregatory effects on platelets. They contract the superfused rat stomach strip bu...

Hepatic metabolism of prostacyclin (PGI2) results in the formation of several biologically inactive lipids and one stable product that has the same chromatographic and biological properties as authentic 6-keto PGE1. Both prostaglandins, 6-keto PGE1 and PGI2, have comparable potency in their antiaggregatory and disaggregatory effects on platelets. They contract the superfused rat stomach strip b...

4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), a potent tobacco-specific carcinogen, has been demonstrated to induce lung tumors in animals and is suspected to be a human carcinogen. Cytochromes P450 are the major enzymes responsible for the activation of NNK in microsomes from the lung and liver of rat and mouse, as well as human liver. The present study investigated the enzymes respons...

using hartree–fock (hf) and ِِdensity functional theory (dft) calculations the thermodynamic properties such as thermal energy , , thermal enthalpy , , thermal entropy , , thermal gibbs free energy , , heat capacity ,cv, and molecular structures of several species involving in keto↔enol tautomerism related to acetaldehyde (a), 5,5-dimethyl-1,3-cyclohexanedione (dimedone) and  acetylacetone (aa) h...