THE REACTION OF THIAMINASE SOLUTION WITH DISULFIDE FORMS OF THIAMINE AND O, S-DIACYLTHIAMINES

The experiment on the factors of reducting or hydrolysing disulfide forms of thiamine or O, S-diacylthiamines and on thiamine-destroying activity of thiaminase solutions of fern, shell-fish, Bacillus thiaminolyticus Matsukawa et Misawa and Bacillus aneurinolyticus Kimura et Aoyama, showed that thermostable and enzymatic, reductive and hydrolytic factors exist in the enzyme solutions, and that disulfide forms of thiamine and O, S-diacylthiamines are at the first step reduced or hydrolysed, followed by decomposition by thiaminase. The decomposition percentages of thiamine disulfide forms of thiamine and O, S-diacylthiamines in the enzyme solutions were compared and thiamine disulfide were found to be more resistant. Diacetylthiamine is considerably decomposed by the solution of fern and shell-fish containing thiaminase I, but remained intact with bacterial enzyme solution containing either thiaminase I or II. Dibenzoylthiamine, however, is generally scarcely destroyed by all these enzyme preparations.