Stable Organophosphorus Analogues of S-Adenosylmethionine and S-Methylmethionine. -The organo-phosphorus analogues of biologically significant sulfonium compounds S-adenosylmethionine (I) and S-methylmethionine (II) are significantly more stable than their carboxylic prototypes. -(ALFEROV, K. V.; ZHUKOV, Y. N.; KHURS, E. N.; KHOMUTOV*, R. M.; Mendeleev Commun. 2003, 6, 243-244; Engelgardt Inst. Mol. Biol., Russ. Acad. Sci., Moscow 117984, Russia; Eng.) -Staver 20-194

The phosphinic analogues of tyrosine and pyruvate were first demonstrated to be substrates in the reactions of elimination and synthesis catalyzed by tyrosine phenol-lyase. Kinetic parameters of the enzymatic process were determined, and the first enzymic synthesis of an aminophosphinic acid was carried out. Replacement of the planar HOOC-group by the tetrahedral (HO)(O)PH-group in the substrate slightly affected its affinity for the enzyme but substantially diminished the conversion rate. For phosphonic analogues, containing (HO)2(O)P group, the affinity to the enzyme was decreased considerably while the conversion was completely prevented. Thus, the structural parameters of the acid group are important not only for the affinity for the enzyme, but also for the formation of the catalytically competent conformation of the active site.

New Synthesis and Fungicidal Activity of a Phosphinic Analogue of Glycine. -Compound (II) exhibits fungicidal activity towards Pyricularia oryzae, a pathogen of rice. -(ZHUKOV, Y. N.; VAVILOVA, N. A.; OSIPOVA, T. I.; KHURS, E. N.; DZHAVAKHIYA, V. G.; KHOMUTOV*, R. M.; Mendeleev Commun. 2004, 3, 93; Engelhardt Inst. Mol. Biol., Russ. Acad. Sci., Moscow 117984, Russia; Eng.) -M. Bohle 43-180

The phosphinic analogues of tyrosine and pyruvate were first demonstrated to be substrates in the reactions of elimination and synthesis catalyzed by tyrosine phenol-lyase. Kinetic parameters of the enzymatic process were determined, and the first enzymic synthesis of an aminophosphinic acid was carried out. Replacement of the planar HOOC-group by the tetrahedral (HO)(O)PH-group in the substrate slightly affected its affinity for the enzyme but substantially diminished the conversion rate. For phosphonic analogues, containing (HO) 2 (O)P group, the affinity to the enzyme was decreased considerably while the conversion was completely prevented. Thus, the structural parameters of the acid group are important not only for the affinity for the enzyme, but also for the formation of the catalytically competent conformation of the active site.

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