Biological glycosidation of macrolide aglycones. II. Isolation and characterization of desosaminyl-platenolide I.

Biological glycosidation of platenolide I (I), a biosynthetic intermediate of 16-membered macrolide antibiotic platenomycin aglycones, with desosamine by Streptomycetes producing 14-membered macrolide antibiotics was attempted. Streptomyces narbonensis producing narbomycin gave a new product designated as 5-O-desosaminyl-platenolide I (III), and Streptomyces venezuelae producing narbomycin and picromycin gave III together with a second new product, 5-O-desosaminyl-14-hydroxyplatenolide I (IV). A nonantibiotic-producing blocked mutant of Streptomyces platensis subsp. malvinus, a producer of platenomycins, converted III to an antibiotically active compound identified as 3-O-propionyl-5-O-desosaminyl-9-dihydro-18-oxo-platenolide I (V).