Additional bioactive compounds and trilobacin, a novel highly cytotoxic acetogenin, from the bark of Asimina triloba

Fractionation of the EtOH extract of the bark of Asimina triloba, monitoring by brine shrimp lethality, has led to the isolation and structural elucidation of a novel highly cytotoxic Annonaceous acetogenin, trilobacin [1], in addition to six known compounds: asimicin 2], bullatacin [3], bullatacinone [4], N-p-coumaroyltyramine [5], N-trans-feruloyltyramine [6], and (+)-syringaresinol [7]. Acetogenin 1 was identified as a diastereomer of asimicin [2] by spectral and chemical methods, and both 1 and 2 showed potent and selective cytotoxicities in the NCI human tumor cell line screen.