Abstract
Attempts were made to elucidate the action mechanism of INAH and several of its derivatives by the utilization of their action in inhibiting growth of Lactobacillus. All these substances were found to show marked inhibition in a concentration of 0.25×10-2M and the inhibition was completely reversed by pyridoxal and pyridoxamine. On keeping the aqueous solution of INAH-G in an incubator, its inhibitive activity became closer to that of INAH, the stronger the longer the period in the incubator. 1-Isonicotinyl-2-methylhydrazine which hardly forms INAH by hydrolysis, showed no inhibitive activity. It was assumed from these experiments that the antibacterial activity of INAH derivatives is due to that of INAH formed by hydrolysis and the antibacterial action of INAH is the result of inactivation by formation of Schiff base with pyridoxal.
