THE BIOGENESIS OF ALKALOIDS: IX. FURTHER INVESTIGATIONS ON THE FORMATION OF GRAMINE FROM TRYPTOPHAN

Abstract

A mixture of dl-tryptophan-2-C14and dl-tryptophan-β-C14with a known ratio of activity in the 2 and β positions was prepared. Feeding it to sprouting barley produced radioactive gramine which was isolated from the leaves. Systematic degradation of the alkaloid showed the activity to be present only in the 2 position of the nucleus and the methylene group of the side chain. The ratio of the activity in the two positions was the same as in the administered tryptophan. These results thus indicate that tryptophan is converted to gramine in the plant without cleavage of the indole–alanine linkage.