Abstract
Maridomycin III, a macrolide antibiotic, was reduced at the aldehyde group to 18-dihydromaridomycin III by culture broth of Nocardia mexicana IFO 3927. 9-Propionylmaridomycin III and josamycin were also reduced to 18-dihydro-9-propionylmaridomycin III and 18-dihydrojosamycin, respectively, by the same strain. The structures of the reduction products were elucidated from the results of their IR, NMR and mass spectra. Antimicrobial activities of the reduction products against Gram-positive bacteria were about 1/10 of their substrates.
