Biologically Active Aspidofractinine,Rhazinilam,Akuammiline,and Vincorine Alkaloids from Kopsia

摘要

Eleven new indole alkaloids,in addition to the previously reported rhazinal (1),and 14 other known alkaloids,were obtained from the Malayan Kopsia singapurensis,viz.,kopsiloscines A-F (2-7),16-epikopsinine (8),kopsilongine-N-oxide (9),16-epiakuammiline (10),aspidophylline A (11),and vincophylline (12).The structures of these alkaloids were determined using NMR and MS analyses.Rhazinal (1),rhazinilam (17),and rhazinicine (18) showed appreciable cytotoxicity toward drug-sensitive as well as vincristine-resistant KB cells,while kopsiloscines A (2),B (3),and D (5) and aspidophylline A (11) were found to reverse drug-resistance in drug-resistant KB cells.