ISOLATION AND IDENTIFICATION OF α‐ASPARTYL‐SERINE, ALANYLPHENYLALANINE AND ISOLEUCYLLEUCINE FROM CALF BRAIN STEM

Abstract

Abstract— A reproducible extraction and fractionation scheme for the isolation of peptides from nervous tissue is described. The low molecular weight fraction, obtained by this procedure from calf brain stem tissue, was further investigated. The presence of N ‐acetyl‐aspartic acid, N ‐acetyl‐α‐aspartylglutamic acid and pyrrolidone‐2‐carboxylic acid was confirmed. The occurrence of minor quantities of glutamylpeptides, identical with or related to known γ‐glutamyldipeptides and glutathione, was indicated. Three hitherto unknown dipeptides α‐aspartylserine, alanylphenylalanine and isoleucylleucine were identified. Mass spectrometry was used in the final structure analysis.