The isolation of some hitherto undescribed products of hydrolysis of proteins.— Part III

Abstract

A base, isolated from the proteins of oats and of castor-bean, differs from the known basic hydrolysis products in being soluble in absolute alcohol. It has theempiricalformula C8H15O3N3, and the molecule contains 1 carboxyl-group, 1 amino-group, and 1 hydroxyl-group. The constitution is unknown. It has been designated "protoctine." It has an acid dissociation constant of 1.8 X10-13. The base and most of its salts are extremely soluble in water. The dibenzoyl derivative melts at 109[degree], the phenyl isocya-nate at 130[degree], and the phenyl hydantoin at 148[degree]C. Color reactions with bromine water and with diazobenzene-sulphonic acid distinguish it from histidine.