Biosynthesis of elsamicin A, a novel antitumor antibiotic.

The 1H noise-decoupled 13C-nmr spectrum of elsamicin A [1] prepared from the cultures of an unknown actinomycete species (ATCC 39417) supplemented with [1-13C]acetate and [2-13C]acetate showed enrichment of all 19-carbons in the aglycone. In addition, L-[methyl-13C]methionine- and D-[1-13C]glucose-supplemented cultures enriched the carbons of the two methyl groups on the disaccharide moiety and the C-1 carbons of the disaccharide, respectively. The results demonstrated that the aglycone of elsamicin A is derived entirely from acetate and the disaccharide portion is biosynthesized from two units of glucose and methionine.