Chemical transformations of the condensation products of structurally different aminoacids with pyridoxal as a function of Ph, solvent, and temperature

Abstract

The kinetics and mechanism of chemical transformations of condensation products of structurally different aminoacids with pyridoxal as a function of pH of the medium, the solvent, and temperature were studied. The Schiff bases were found to be the most stable at pH close to neutral values. In acidic media the condensation products of α-aminoacids with pyridoxal decompose to the starting components. In alkaline media the elimination of the α-hydrogen atom from the aminoacid fragment and rearrangement of the Schiff base into the quinoid form occurs, the subsequent hydrolysis leading to the formation of pyridoxamine and ketoacids. The condensation products of the β- and e-aminoacids with pyridoxal decompose to the starting components in acidic media but are stable in alkaline media.