The author synthesized hydroxythiamine triphosphate by phosphorylating hydroxythiamine with metaphosphate according to Viscontini et al., and Koike. The author found that the synthetic hydroxythiamine triphosphate inhibited competitively the action of thiamine triphosphate in the carboxylase system isolated from bakers' yeast according to Green et al. This result agreed with that of Velluz et al.
