A mixture of two novel cytotoxic adjacent bis-tetrahydrofuran (THF) ketolactone acetogenins, (2,4-cis and tram)-bulladecinones (1 and 2), was isolated from the bark of Annona bullata Rich. (Annonaceae). Adjacent bis-THF rings, located at C-12 and C-16 and having only one adjacent hydroxyl group, and the presence of an erythro vicinal diol in 1 and 2 are new features for the Annonaceous acetogenins.