New amide N-glycosides of ansamitocins identified from Actinosynnema pretiosum.

By using preparative TLC as the critical isolation procedure, two compounds, including one new amide N-glycosides of ansamitocin (2), were isolated from Actinosynnema pretiosum. The compounds were elucidated as N-demethyl-N-beta-D-glucopyranosyl ansamitocin P-2, named ansamitocinoside P-2 (1), and N-demethyl-N-beta-D-glucopyranosyl ansamitocin P-1, named ansamitocinoside P-1 (2) on the basis of their spectral data. The 1H-NMR and 13C-NMR assignments were made for 1 and 2 while the 13C-NMR assignment for 1 was revised. Bioassay results showed that 1 had antineoplastic activity.