抄録
From the estimation of urinary thiamine excretion after intraperitoneal administration of thiamine or O-acylthiamine, it was suggested that O-acylthiamine was much more metabolized than thiamine in rat. Metabolism of O-acylthiamine was investigated in vitro, using various rat tissue homogenates, and the enzyme which metabolizes O-acylthiamine to thiochrome-negative substance was found in liver, but scarcely in other tissues. The enzyme was partially purified from rat liver, and the reaction product of O-acylthiamine with this enzyme was isolated as colorless needle crystal, mp. 231-2℃. It was identified as thiamine thiazolone, which has the structure added oxygen atom to 2C-position of thiazole ring of thiamine, by infrared absortpion spectra, paper and thin layer chromatography and elementary analysis. This enzyme, which produce thiamine thiazolone from O-acylthiamine, was named O-acylthiamine oxidase tentatively.
