Abstract
In the presence of 5×10^-11 mole pyridoxine-HCl/4ml, imidazolothiamine compounds (imidazolothiamine, benzyl- or butylimidazolothiamine) showed the inhibition as antithiamine to the growth of Saccharomyces carlsbergensis in the concentrations lower than 10^-8mole thiamine-HCl/4ml. In the concentrations higher than 10^-8 mole thiamine-HCl/4ml, benzylimidazolothiamine showed the growth-inhibition which was recovered by addition of pyridoxine, but not by addition of thiamine. A molar ratio of benzylimidazolothiamine to thiamine or pyridoxine required for 50% growth-inhibition was about 200 or 38,000. Benzylimidazolothiamine inhibited the cell-uptake of thiamine more strongly than the cell-uptake of pyridoxine, when the sufficient amount of thiamine and pyridoxine with benzylimidazolothiamine was added to the broth.
