Reference

The reactions of phenylglyoxal and related reagents with amino acids

The reactions of phenylglyoxal and related reagents with amino acids. Takahashi, Kenji (Fac. Sci., Univ. Tokyo, Tokyo, Japan). J. Biochem. (Tokyo), 81(2), 395-402 (English) 1977. CODEN: JOBIAO. DOCUMENT TYPE: Journal CA Section: 6 (General Biochemistry) Section cross-reference(s): 34 The reaction of phenylglyoxal (PGO), glyoxal (GO), and methylglyoxal (MGO) with amino acids was investigated at mild pH values at 25.degree.. These aldehydes reacted most rapidly with arginine, the rate of reaction increasing with increasing pH values. Histidine, cystine, glycine, tryptophan, asparagine, glutamine, and lysine reacted with these aldehydes at significant but various rates, depending on the pH and the reagent used. The reactions seemed to involve both the .alpha.-groups and the side-chain groups. Di-PGO-L-arginine was prepd. from N.alpha. 56-87-1 and 22661-87-6 are cas registry numbers of chemicals which are used as reagents here.-benzyloxycarbonyl-L-arginine and di-PGO-methylguanidine was prepd. from methylguanidine. The stoichiometry of the reaction of 2 PGO mols. with 1 guanidino group was confirmed. A glyoxal deriv. of L-arginine (GO-arginine) was prepd. by reaction of glyoxal with arginine. GO-arginine was fairly unstable, esp. at higher pH values. A similar deriv. (MGO-arginine) was also formed by reaction of MGO with L-arginine. This deriv. was also unstable. .