Abstract
It was observed that yield of hydroxyiminothoiamine (IV) was increased by addition of glycine with equimolar NaOH in the reaction of thiamine (I) with hydroxylamine in NaOH solution. The addition of desthiothiamine (III) also increased the yield of (IV), corresponding to the amount of (III). When desthiothiamine was reacted with hydroxylamine, phenylhydrazine, ammonia or benzylamine in weak acidic or alkaline solution, formation of hydroxyiminothiamine, phenylhydrazonothiamine (V), imidazolethiamine (VI) and benzylaminothiamine (VII) were demonstrated by means of paper partition chromatography. When desthiothiamine, hydroxyiminothiamine, phenylhydrazonothiamine or thiosemicarbazonothiamine (VIII) was heated with 10 % hydrochloric acid, formic acid was demonstrated in the reaction mixture, and thiamine was also shown to be formed by saturation of H_2S in the acetate buffer solutions (pH 5.0) of these compounds at 90℃. But the formation of formic acid and thiamine were not demonstrated in the case of imidazolethiamine and benzylaminothiamine.
