Amino Acids and gamma-Glutamyl Derivatives in Seeds of Lunaria annua L.

Abstract

Unhydrolyzed seed extracts of L. annua (Cruciferae) were investigated for ninhydrin-reacting constituents. gamma-L-Glutamyl-[beta]-alanine, not previously found in nature, was isolated and identified on comparison with a synthetic sample. In addition, gamma-L-glutamyl-[beta]-aminoisobutyric acid, m-carboxy-L-phenylalanine and 3-(3-carboxy-4-hydroxyphenyl)-L-alanine (m-carboxy-L-tyrosine), all previously known from higher plants, were isolated in crystalline form. The presence of still other amino acids, such as several of the ordinary protein constituents, as well as [beta]-alanine, [beta]-aminoisobutyric acid and m-carboxyphenylglycine, was demonstrated by paper chromatog-raphy. A minor constituent is tentatively regarded as [alpha]- or gamma-glutamyl-gamma-aminobutyric acid, whereas 2 additional glutamic acid derivatives are still under consideration. The Lunaria seed extract is the 1st reported source of the simultaneous occurrence of the 3 m-carboxy-substituted aromatic amino acids encountered so far in higher plants. The occurrence of the above-mentioned and related compounds in the plant kingdom is briefly discussed.