Novel tirucallane triterpenoids from the stem bark of Toona sinensis.
Fitoterapia. 2016 Jul ;112:97-103. Epub 2016 May 20. PMID: 27215130
Phytochemical investigation on the stem bark of Toona sinensis was carried out by various chromatographic techniques resulting in the isolation and elucidation of two novel tirucallane triterpenoids, named (20S)-3-oxo-tirucalla-25-nor-7-en-24-oic acid (1) and (20S)-5α,8α-epidioxy-3-oxo-24-nor-6.9(11)-dien-23-oic acid (2), along with fifteen known triterpenoids (3-17), their structures were determined by extensive spectroscopic methods, including 1D-, 2D-NMR and HR-ESI-MS experiments. Compound 2 is uncommon in nature, which possesses a peroxide bridge cross C-5 and C-8 in the triterpenoid skeleton. All isolated compounds were evaluated for cytotoxicity against five human tumor cell lines (A-549, Hela, HepG2, SGC-7901 and SW-480), among them, compound 17 displayed strongest cytotoxic activity against A-549 cells and the results indicated that its cytotoxicity against A-549 cells was mediated by the intrinsic mitochondrial apoptotic pathway. In addition, ROS production-inhibitory activities were also evaluated, but none of them was active.