Abstract
It was found that in the rat about 50% of orally administered thiamine was decomposed into 4-methyl-5β-hydroxyethylthiazole (HT) and pyrimidyl derivative. It was demonstrated that 2-methyl-4-amino-5-hydroxymethylpyrimidine (HMP) was formed from thiamine as one of pyrimidyl derivatives. However, the amount of excreted HMP was extremely small as compared to that of excreted HT. It was concluded that the main cleavage of thiamine was not a direct hydrolysis into HT and HMP.
