Abstract
1. Monosulfoxides of symmetrical disulfide-type thiamine derivatives were synthesized by oxidation with perbenzoic acid instead of H2O2. As a solvent, acetic acid or acetic acid in chloroform gave better results than chloroform alone. The oxidation products thus obtained were identified as monosulfoxides of symmetrical disulfide-type thiamine derivatives by elementany analyses, ultraviolet and infrared absorption spectra and HI reaction.
2. One molecule of O-benzoylthiamine disulfide monosulfoxide (BTDSO) was found to be reduced with excess cysteine (pH 8.5-9) or Na2S2O3 (pH 4-5) to two molecules of free thiamine. Preventive test of BTDSO in thiamine-deficient lovebirds showed the same activity as thiamine, OBT and BTDS. Biologically, one molecule of monosultoxide was estimated to correspond to two molecules of thiamine.
3. When BTDSO was orally and intravenously administered in rabbits, the blood thiamine level was higher and retained longer than in the case of thiamine and BTDS.
