Shinjulactone O, a new quassinoid from the root bark of Ailanthus altissima

A new quassinoid, shinjulactone O (1), and seven known quassinoids, were isolated from the 50% ethanol extract of the root bark of Ailanthus altissima. The structures of these compounds were determined based on spectroscopic methods including UV, IR, HR-ESI-MS, 1D and 2D NMR. Their cytotoxic activities were evaluated on the tumour cell lines MCF-7, MDA-MB-231, HepG2 and A549 cells, as well as the normal HUVEC line in vitro. Compounds 1-8 exhibited different levels of inhibitory activity against tumour cell lines.