Studies on the biogenesis of some simple amines and quaternary ammonium compounds in higher plants. : Isoamylamine and isobutylamine

Abstract

In vivo infiltration of the inflorescences of Sorbus aucuparia and Crataegus monogyna with L-leucine-U- 14C and L-valine-U- 14C gave rise to radioactive isoamylamine and isobutylamine respectively. Simple enzyme preparations from the flowers of both species protected with polyvinylpyrrolidone (PVP) catalysed the decarboxylation of DL-leucine-1- 14C and L-leucine-U- 14C. The product of the decarboxylation was isoamylamine. The enzyme in both species was substantially inhibited by hydroxylamine. Extracts from Crataegus monogyna required the addition of the co-enzyme pyridoxal phosphate for maximum activity, whereas extracts from Sorbus aucuparia did not. The enzyme in Sorbus aucuparia was in the soluble cytoplasmic fraction and appeared to have an optimum pH in the region of 7·5.