DECOMPOSITION OF THIAMINE DERIVATIVES BY ULTRAVIOLET IRRADIATION

Abstract

When thiamine derivatives were irradiated by a ultraviolet lamp with a maximum spectral energy at 365 mμ, the symmetric disulfides (thiamine disulfide, O-benzoylthiamine disulfide, O-benzenesulfonylthiamine disulfide, deoxythiamine disulfide, thiamine disulfide-O-methylether) and S-acylated thiamine (diacethylthiamine, O-acetyl-S-benzoylthiamine, O-benzoyl-S-acetylthiamine) were unstable, being remarkably decomposed, whereas the unsymmetric disulfides (thiamine propyl disulfide, thiamine tetrahydrofurfuryl disulfide) were somewhat resistant and S-carbethoxy-B₁, (S-carbethoxythiamine, dicarbethoxythiamine) and S-benzoylthiamine monophosphate were decomposed most slowly. On the other hand, thiamine, deoxythiamine or thiothiamine were hardly or not at all decomposed under the same condition. As a decomposition product of O-benzoylthiamine disulfide, 2-methyl-4-amino-5-aminomethyl pyrimidine was isolated and was identified as its picrate.