The origin of the carbon chain in the thiazole moiety of thiamine in Escherichia coli: Incorporation of deuterated 1-deoxy-D-threo-2-pentulose

Abstract Non growing washed cells of Escherichia coli , derepressed for the biosynthesis of thiamine, have been incubated in the presence of glucose and either 1-deoxy- D - threo -2-pentulose 1 or 1-deoxy- D - erythro -2-pentulose 2 trideuterated on the methyl group. The incorporation of deuterium into the thiazole moiety of thiamine was measured by mass spectrometry. The label of the threo -compound was found in more than 40% of the thiazole biosynthesized in its presence; the label of the erythro -compound in less than 5%. Hence it is likely that the carbon chain of 1-deoxy- D - threo -2-pentulose is the precursor of the five carbons chain of the thiazole moiety of the thiamine molecule in E. coli .