| 摘要 |
Screening of crude extracts of the bark of Annona bullata Rich. (Annonaceae) showed cytotoxic and pesticidal activities. By monitoring with brine shrimp lethality, two novel extremely potent acetogenins, bullatacin (1) and bullatacinone (2), were isolated. Spectral and chemical methods identified bullatacin as a diastereomer of asimicin. Bullatacinone represents bullatacin with the lactone cleaved and reformed at the 4-OH. Unlike asimicin, which is more generally cytotoxic, 1 and 2 show some selective cytotoxicities in human tumor cell lines, and certain susceptible cells give ED50 values as low as 10-12-10-15 mcg/ml. Bullatacin was pesticidal at concentration as low as 1 ppm, while bullatacinone lacked pesticidal activities.
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