Isolation, chemotaxonomic significance and cytotoxic effects of quassinoids from Brucea java']javanica

A new quassinoid, bruceene A (1) along with seventeen known quassinoids (2-18) was isolated from the fruits of Brucea javanica. The structure of 1 was elucidated by extensive spectroscopic methods, and was further confirmed by single-crystal X-ray diffraction analysis. Isolation of similar quassinoids 1-3 as those in genus Ailanthus from genus Bruce a, indicated the close chemotaxonomic relationship between these two genera, which further supported the phylogenetic study by DNA analysis. Compounds 5, 7, 10 and 12 with a 3-hydroxy-3-en-2-one moiety showed potent inhibitory activities against the MCF-7 and MDA-MB-231 cells with IC50 values in the ranges 0.063-0.182 mu M and 0.081-0.238 mu M, respectively; while glycosidation at 3-OH significantly decreased the cytotoxicity. It was also found that the most potent compound 7 induced apoptosis in MCF-7 cells via the intrinsic mitochondrial apoptotic pathway. (C) 2015 Elsevier BY. All rights reserved.