Thiamine deficiency in all species thus far studied affects the metabolism of pyruvic acid. The lacki until quite recently (l), of a rapid specific method for estimating pyruvic acid necessitated the use of the rapid but less specific technique introduced by Clift and Cook (2). Occasionally it has been estimated by isolation as the 2,4-dinitrophenylhydrazone, by the method of Case (3) or a modi...

The Schiff base molecule of the title compound, C(14)H(12)N(4)O(6)·C(5)H(5)N, was obtained from the condensation reaction of 2-hy-droxy-3-meth-oxy-benzaldehyde and 2,4-dinitro-phenyl-hydrazine. The C=N bond of the Schiff base has a trans arrangement and the dihedral angle between the two benzene rings is 3.49 (10)°. An intra-molecular N-H⋯O hydrogen bond generates an S(6) ring. In the crystal, ...

A simple and sensitive procedure for determination of ethanol in biological samples was established. In this procedure, ethanol in biological samples was first converted to acetaldehyde by yeast alcohol dehydrogenase. Then, acetaldehyde formed was derivatized to 2,4-dinitrophenylhydrazone, which was determined by gas chromatography with an electron-capture detection. Ethanol concentration in 1 ...

Mitochondrial monoamine oxidase was inactivated with 2-[2-’4C]phenylcyclopropylamine, dialyzed, and treated with acidic 2,4-dinitrophenylhydrazine. Contrary to the report of Paech et al. (Paech, C., Salach, J. I., and Singer, T. P. (1980) J. Biol. Chern. 255, 2700-2704), the 2,4-dinitrophenylhydrazone obtained was not that of 2-phenylcyclopropanone, but rather of cinnamaldehyde. Futhermore, den...

Mitochondrial monoamine oxidase was inactivated with 2-[2-14C]phenylcyclopropylamine, dialyzed, and treated with acidic 2,4-dinitrophenylhydrazine. Contrary to the report of Paech et al. (Paech, C., Salach, J. I., and Singer, T. P. (1980) J. Biol. Chem. 255, 2700-2704), the 2,4-dinitrophenylhydrazone obtained was not that of 2-phenylcyclopropanone, but rather of cinnamaldehyde. Furthermore, den...

With a washed and dialyzed preparation of rabbit kidney cortex mitochondria, the requirement of Mg ++ (or R/In++), inorganic phosphate, and adenosinetriphosphate for the enzymatic oxidation of a-ketoglutarate to succinate plus COZ may be readily demonstrated (2), confirming results (3) with cat heart muscle. Diphosphothiamine is a necessary coenzyme for this enzymatic system (4, 5). However, in...