A biosynthetic scheme is proposed for the ravidcmycin aglycone. Incorporation of 13C-labeled precursors was followed by conventional and 2-dimensional NMR techniques.The yellow antitmr antibiotic ravidanycin 1, recently isolated frQn Streptanyces ravidusl, represents the newest member of the chrysomycin family of antibiotics. Possible routes for the biosynthesis of the aglycone portion of these antibiotics has been discussed by Weiss et a1.2 in conjunction with their work on the chryscmycins. Given the difficulty of constructing the aglycone carbon skeleton fran the simple folding of a single polyketide chain, they proposed a biosynthetic model based upon the rearrangement of an intermediate 1,2+enzanthraquinone. An alternate explanation involves the ambination of tW separate polyketide chains to give the carbon skeleton directly. Examples of this latter type of construction are known.3 This report presents experimental evidence for a biosynthetic scheme involving the rearrangement of a decaketide intermediate in a novel species of Streptcxnyces.