ナトリウムアルコラート溶液に溶かしたビタミンB_1の酸化反応

抄録

Oxidation of thiamine to its disulfide and to thiochrome was studied using air or N-bro-mosuccinimide as oxidants. Addition of 2 moles of Na-alcoholate to alcoholic suspension of thiamine hydrochloride gave a yellowish solution of free base, precipitating NaCl quantitatively. Dried air, passed through the alkali was introduced into this solution at room temperature. After aeration, thiochrome, thiamine disulfide and thiamine-thiazolone were obtained from the mixture. Paper chromatography of the mixture revealed the presence of thiamine, thiamine disulfide, thiochrome, thiamine-thiazolone, thiothiamine, vitachrome and unknown fluorescent substance. The above stated that ethanol solution of free base gave thiochrome by the action of one mole of N-bromosuccinimide, while thiamine disulfide by 0.5 mole of the oxidant. In aqueous solution, however, thiamine was oxidized to thiamine disulfide by N-bromosuccinimide and NaOH.