Rancinamycins, metabolites produced by Streptomyces lincolnensis in sulfur-depleted media.

Rancinamycins I, II, III, and IV are secondary metabolites produced by Streptomyces lincolnensis in a sulfur-depleted culture medium. Rancinamycins I, and II, the main components of the mixture, show broad spectrum antibiotic activity in vitro. Subcutaneously injected or orally administered antibiotic afforded no protection for experimentally infected mice against lethal challenges of Staphylococcus aureus. Radioactive tracer studies failed to demonstrate that the rancinamycin were precursors in the biosynthesis of lincomycin.