RADIOFORMATION OF ASPARTIC ACID IN AQUEOUS SOLUTIONS OF ALANINE

Abstract

Aspartic acid was found to be present in 0.1 M aqueous solutions of alanine irradiated with gamma rays from cobalt-60 under three different experimental conditions: (a) in the presence of air, (b) in a nitrogen atmosphere, and (c) in the presence of nitrogen plus CO2. Although the presence of oxygen and CO2in the solutions was necessary for the formation of appreciable quantities of aspartic acid, small quantities of it may be formed in their absence. Addition of CO2to the nitrogen atmosphere favored formation of aspartic acid at the lowest levels of irradiation, but the amount decreased rapidly with higher levels. Degradation of alanine was less in the presence of oxygen than under the other two experimental conditions. Addition of CO2to the nitrogen atmosphere had no effect on the degradation of alanine. Two possible mechanisms to explain the radiochemical degradation of alanine with formation of aspartic acid are proposed.