In vitro: |
J Nat Prod. 2007 Nov;70(11):1783-9. | Biologically active aspidofractinine, rhazinilam, akuammiline, and vincorine alkaloids from Kopsia.[Pubmed: 17939738] | METHODS AND RESULTS:
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.
CONCLUSIONS:
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. |
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