A New C22‐Quassinoid with Anti‐Pancreatic Adenocarcinoma Activity from Seeds of Brucea javanica

An undescribed C22-quassinoid named sergeolide A (1) and fifteen known quassinoids (2-16) were obtained from the seeds of Brucea javanica (Simaroubaceae). All chemical structures were established based on spectroscopic data and X-ray diffraction analysis. Sergeolide A (1) is the first example of a naturally occurring C22-quassinoid bearing a butenolide group fused the A ring of the bruceolide skeleton from Brucea genus. And this is the first report of the NMR data for desmethyl-bruceines B (2) and C (3) and the crystal structure for bruceolide (11). In addition, all isolates were evaluated for their anti-pancreatic adenocarcinoma activity by measuring the growth inhibitory of the MIA PaCa-2 cell lines. Consequently, compounds 1, 7-10, and 12-16 exhibited potent anti-pancreatic cancer activity in vitro (IC50 =0.054∼0.357 μM).