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.
Keywords: (20S,24R)-epoxydammarane-1225-diol-3-one (PubChem CID: 14038588); (20S,24R)-epoxydammarane-3β,25-diol (PubChem CID: 11385662); 20-hydroxy-24-dammaren-3-one (PubChem CID: 441676); Cytotoxic activity; ROS production-inhibitory activity; Tirucallane triterpenoids; Toona sinensis; bourjotinolone B (PubChem CID: 101280173); cabralealactone (PubChem CID: 44421647); cylindrictone D (PubChem CID: 25104959); methyl shoreate (PubChem CID: 44421646); ocotillone (PubChem CID: 12313665); richenone (PubChem CID: 101599479); shoreic acid (PubChemCID: 12315515).
Copyright © 2016 Elsevier B.V. All rights reserved.