Two new adjacent bis-tetrahydrofuran annonaceous acetogenins from seeds of Annona cornifolia.

Two new adjacent bis-THF annonaceous acetogenins, 9-hydroxyfolianin (1) and folianin B (2), together with two known acetogenins, asimicin (3) and bullatacin (4), significantly bioactives in brine shrimp lethality test, were isolated from seeds of Annona cornifolia A. St. Hil (Annonaceae). Their structures were elucidated by NMR and ESI-MS analysis, and relative configurations were established. The absolute configuration around the THF rings of 1 was defined by Mosher esters methodology and circular dichroism.