Cleavage of the Imidazole Ring of Histidine and Carnosine by Bromine. ∗

Abstract

Summary

When histidine and related compounds are treated with bromine at pH 1 to 1.5, the excess bromine removed, and the solution alkalinized and aerated, significant amounts of ammonia are recovered from the imidazole ring. Copper carnosine, copper acetyl histidine, and imidazole lactic acid yield amounts of ammonia which correspond to a complete cleavage of the ring nitrogen. Histidine yields sufficient ammonia to account for all of the ring nitrogen plus almost one-half of the alpha-amino nitrogen. Other compounds tested gave 13-55% of their imidazole nitrogen as ammonia.