New amide N-glycosides of ansamitocins identified fromActinosynnema pretiosum

By using preparative TLC as the critical isolation procedure, two compounds, including one new amideN-glycosides of ansamitocin (2), were isolated fromActinosynnema pretiosum. The compounds were elucidated asN-demethyl-N-β-D-glucopyranosyl ansamitocin P-2, named ansamitocinoside P-2 (1), andN-demethyl-N-β-D-glucopyranosyl ansamitocin P-1, named ansamitocinoside P-1 (2) on the basis of their spectral data. The1H-NMR and13C-NMR assignments were made for1 and2 while the13C-NMR assignment for1 was revised. Bioassay results showed that1 had antineoplastic activity.