Competitive inhibition of thiaminetriphosphate action by oxythiaminetriphosphate in the carboxylase system.

the attacks of convulsion or death of the mouse and rat caused by injecting the pyrimidine moiety of thi amine, i. e. 2-methyl-6amino-5-hydroxymethylpyrimidine, (conveniently call ed "toxopyrimidine"), were protected by the substance, contained in the rice-bran, and they confirmed that vitamin B6-complex was the typical antimetabolite against toxopyrimidine be cause of partial similarity of their structure. K. Makino and M. Koike (6) confirmed further the analogous rela tion between toxopyrimid ine phosphate and pyridoxal