TRANSFORMATION DE L'ACIDE γ-HYDROXYGLUTAMIQUE EN ALANINE ET EN ACIDE GLYOXYLIQUE

Abstract

A method is described for the synthesis of γ-hydroxyglutamic-5-C¹⁴ acid (racemic mixture). Doses of this substance were administered intraperitoneally to rats and among the amino acids isolated from the tissue proteins, glycine showed the highest radioactivity. This finding is compatible with the postulated theory that γ-hydroxyglutamic acid may be cleaved with the formation of alanine and glyoxylic acid, the latter being normally converted into glycine by amination in the animal tissues. Following the incubation of γ-hydroxyglutamic-5-C¹⁴ acid and also γ-hydroxyglutamic-2-C¹⁴ acid in the presence of rat liver homogenates, evidence was obtained, by the carrier technique, for the direct formation of radioactive glyoxylic acid and alanine; no trace of glutamic acid or aspartic acid could be detected in the incubation media. As a result of a comparative study of the breakdown in vitro of the racemates of γ-hydroxyglutamic-5-C¹⁴ acid, it was found that the isomers of erythro-DL-γ-hydroxyglutamic acid are utilized to a much greater extent than the isomers of threo-DL-γ-hydroxyglutamic acid.