STRUCTURAL ELUCIDATION OF ROKITAMYCIN, MIDECAMYCIN AND ERYTHROMYCIN METABOLITES FORMED BY PATHOGENIC NOCARDIA

Pathogenic Nocardia spp. converted rokitamycin, midecamycin and erythr omycin into inactive metabolites, the structures of which were determi ned from NMR and mass spectral data. Depending on the species of Nocar dia, these macrolides underwent phosphorylation at 2'-OH, hydrolysis o f the 4''-O-acyl group, glycosylation at 2'-OH and/or reduction of the 18-formyl group. Full H-1 and C-13 assignments are presented and some solvent effects are described.