Effect of ionizing radiation and U.V. light on N-acetylglycine in the presence of ammonia.

Abstract

Aqueous solutions of 1-14C-N-acetylglycine and ammonia were irradiated with 7.5 MeV fast electrons,60Co γ-rays, and u.v. light (low pressure mercury lamp). The products and their hydrolyzates were separated by electrophoresis, paper chromatography, and ion exchange chromatography. Among the main reactions are: decarboxylations, aminations yielding diglycine, dimerizations giving rise to diaminosuccinic acid, succinic acid, aspartic acid, β-aspartylglycine, β-alanylglycine, and the N-acetyl derivatives of these compounds. Methylations yield α-alanine, and a reductive transacetylation yields threonine. The results are briefly discussed with respect to the effect of different concentrations and the use of different qualities of radiation. The results also point to a possible pathway to the prebiotic origin of a number of biologically important micromolecules, including oligopeptides. The results indicate, however, that a prebiotic formation of polypeptides or protein-like macromolecules by the action of ionizing radiations or u.v. light upon aqueous solutions of monomers is unlikely under the conditions of this investigation.