Widespread occurrence of 2-acetylthiazole-4-carboxylic acid in biological material

2-Acetylthiazole-4-carboxylic acid was shown to be widely distributed in all organisms tested, which included members of the eukaryotes, archaebacteria, and eubacteria. This thiazole, which was identified and quantitated as the methyl ester methoxyamine derivative, was found in these organisms at levels of from 27 to 1100 nmol/g dry weight (d.wt) of tissue. On the basis of its widespread occurrence, the levels at which it occurs in these organisms, and its chemical structure, which contains a reactive carbonyl group, it is proposed that this compound is a previously undescribed coenzyme.