Studies on the Biosynthesis of Mitomycin C by <i>Streptomyces verticillatus</i>

Abstract

Of a series of 14 C-labeled substrates tested as precursors of mitomycin C, D-glucose was the most effective. L-Methionine-methyl- 14 C specifically labeled the methoxyl but not the C-methyl substituent; several precursors which labeled the carbamyl group were probably first metabolized to carbon dioxide. Other results suggest that the carbon skeleton of mitomycin is not assembled from an aromatic precursor derived by either the shikimate or polyketide pathways, and is not a disguised sesquiterpene. The distribution of radioactivity in C-6 and the attached methyl group of mitomycin C labeled from glucose-1- 14 C, -2- 14 C, and -6- 14 C is consistent with derivation of the methylbenzoquinone moiety from a seven-carbon intermediate which, in turn, originates from glucose by reactions of the nonoxidative pentose phosphate pathway. An additional molecule of glucose may supply the six remaining carbon atoms of the mitomycin C skeleton.