Abstract
Compound X, reported as an intermediate in the biosyn-thesis of biotin from dethiobiotin (DTB) (Biochem. Biophys. Res. Commun., 88, 312 (1979)), was found to contain N-formyl DTB and biotin. The methyl ester of N-formyl biotin was considered to be a product from the biotin, which was biosynthesized from DTB by resting cells of E. coli C 124, through treatment with diazomethane in the presence of a trace amount of formic acid after Dowex 1X2 column chromatography. NMR analysis revealed that biotin was formylated at 1'-N. N-Formylated DTB and biotin are new biotin derivatives.