Abstract
In order to ascertain the existence of thiothiamine in natural foodstuffs, which have been previously proved by chemical or microbiological method, the acid water extract of onion was shaken with acid clay, then the separated clay was eluted by 50% ethanol containing HCl. The eluate was evaporated and extracted by butanol, the butanol solution was further fractionated through column-chromatogram using filter-paper pulp. Finally thiothiamine was identified as the spot of Rf 0.72 by paper chromatography (acetic acid・butanol・water=1 : 4 : 5) of the concentrate. An another proof of thiothiamine was carried out through its transformation into thiochrome by cyanogen bromide in acid medium, the aqueous extract of onion or of cabbage was kept for 30 minutes with excess of cyanogen bromide at pH 3.5,and then cyanogen bromide was expelled by aeration. During this process thiamine in the solution had been unchanged. Thus formed thiochrome was extracted by butanol from the solution after addition of NaOH and identified by paper chromatography and spectrophotography. The extract of cabbage showed an another spot beside thiochrome, while that of onion indicated one spot of thiochrome only at paper chromatography.
