Studies on the biosynthesis of basic 16-membered macrolide antibiotics, platenomycins. IV. Biosynthesis of platenomycins.

To elucidate the biosynthetic pathway of platenomycin (PLM), biosynthetic relationships of platenolides I (PL-I) and II (PL-II), 3-O-propionyl-5-O-mycaminosyl platenolides I (PPL-I-MC) and II (PPL-UU-MC), 9-dehydro demycarosyl platenomycin (DDM-PLM) were examined with growing cultures or the washed mycelium of blocked mutants of Streptomyces platensis subsp. malvinus MCRL0388, a platenomycin-producing organism. As a result, it was revealed that PLM was biosynthesized from PL-I via DM-PLM and DA-PLM along the pathways shown in Chart 1. 4''-Isovaleroyl unit of PLM-A and 4''-propionyl unit of PLM-B were respectively derived from L-leucine and L-isoleucine.