Three cytotoxic Annonaceous acetogenins from the seeds of Annona squamosa

Three new Annonaceous acetogenins, squamocin-IV (1), squamocin-V (2) and squamoxinone-E (3), together with seven other known Annonaceous acetogenins (4–10) were isolated from the seeds of Annona squamosa. The structures of all of the isolates were established and characterized through spectral and chemical methods. The new Annonaceous acetogenins 1–3 were evaluated for their cytotoxicity against the Hep-G2, SMMC-7721, BEL-7402, BGC-803 and H460 human cancer cell lines. Compound 3 exhibited the best cytotoxic activity, with IC₅₀ values of 0.103, 0.687, 4.19, 0.43 and 6.56 μg/mL, respectively for the cell lines above; meanwhile, Compound 1 showed selective cytotoxic activity against H460, with an IC₅₀ value of 0.049 μg/mL. The first mono-ACG (2) composed of 38 carbons was discovered.