STUDIES ON MARIDOMYCIN FERMENTATION .4. INTERCONVERSION AMONG 16-MEMBERED MACROLIDE ANTIBIOTICS BELONGING TO LEUCOMYCIN-MARIDOMYCIN GROUP

To clarify the biosynthetic pathway of maridomycin, the biosynthetic relation among 16- membered macrolide antibiotics belonging to leucomycin-maridomycin group was examined with intact cells or growing cultures of Streptomyces hygroscopicus No. B-5050-HA and its mutants. Carbomycin A, B and leucomycin As were converted to maridomycin II in the pH range of 5.5˷7.5 with an optimum between 6.0˷6.5. But, maridomycin II was not converted to leucomycin A3 or carbomycin B. These findings were confirmed by culture experiment. Leucomycin A3, carbomycin A and B added to the culture at 48 hr were almost completely converted to maridomycin II. On the basis of these facts, we propose a biosynthetic relation among leucomycin A3, carbomycin A, carbomycin B and maridomycin II. © 1979 Taylor & Francis Group, LLC.