Irumamycin, an antifungal 20-membered macrolide produced by a Streptomyces. Taxonomy, fermentation and biological properties.

Irumamycin is a new 20-membered macrolide antibiotic isolated from a culture broth of a soil isolate which was named Streptomyces subflavus subsp. irumaensis AM-3603. It is active in vitro against some phytopathogenic fungi, but inactive against most aerobic and anaerobic bacteria and mycoplasmas. The potent in vitro activity and the results of preliminary pot tests indicated that the antibiotic is practicable as an agricultural antifungal agent.