Abstract
The new oxidized products of thiol-type thiamines, 2-[2'-methyl-4'-aminopyrimidyl-(5')]-methylformamino-5-hydroxy-Δ^2-pentenyl-3-sulfonic acid (thiaminic acid) and its O-benzoyl ester, were obtained by the oxidation of thiamine disulfide or its benzoyl ester with hydrogen peroxide. The other derivatives of thiol-type thiamines such as thiamine alkyl disulfide, S-acylated thiamine and cyanothiamine, which are easily reduced to thiamines by treating with cysteine or other sulfhydryl compounds, were also converted into the thiaminic acids through the similar oxidation. Further, several O-acyl derivatives of thiaminic acids were prepared by the oxidation of O-acylated thiamine disulfides and O, S-acylated thiamine or by the acylation of thiaminic acid.
