Bacterial metabolism of thiamine. I. The isolation and characterization of the initial intermediates in the oxidation of thiamine.

The first intermediates in the metabolism of thiamine by a microorganism isolated from soil are Z-methyl-4-amino-5hydroxymethylpyrimidine and 5-(2-hydroxyethyl)-4-methylthiazole. The pyrimidine is further metabolized, first to 2-methyl-4hydroxy-5-hydroxymethylpyrimidine followed by 2-methyl4-hydroxy-5-pyrimidine-carboxylic acid. The thiazole metabolites 4-methylthiazole-5-acetic acid and 2-oxyd-methylthiazole-5-acetic acid also accumulate in the incubation medium but it is not known as yet whether they are derived directly from 5-(2-hydroxyethyl)-4-methylthiazole.