Objective To investigate the chemical constituents of limonoid-type triterpenes from the 95% ethanol extract of Melia toosendan and their antitumor activity. Methods The compounds were isolated and purified using various chromatographic techniques, including normal-pressure column chromatography, high-pressure column chromatography, and gel column chromatography. The isolated compounds were structurally characterized by modern spectroscopic techniques. Their antitumor activity was evaluated using the CCK-8 assay. Results Eight limonoid-type triterpenoids were isolated from the ethyl acetate extract of M. toosendan. Structural elucidation by spectroscopic techniques identified them as 15-oxotrichilinin (1), 11,15-dioxotrichilinin (2), 12-O-ethyl nimbolinin B (3), mufolinoid U (4), trichilinin (5), trichilinin D (6), trichilinin E (7), and trichilinin G (8). Activity evaluation results showed that all compounds exhibited varying degrees of inhibitory effects on four tumor cell lines. Conclusion Compound 1 is a new compound, named 15-oxotrichilinin. Antitumor activity results indicated that compounds 1—8 all possess antitumor activity to varying extents, with some compounds showing favorable activity against HepG2 cells.

Melia toosendan Sieb. et Zucc.  /  limonoid-type triterpene  /  antitumor activity  /  15-oxotrichilinin  /  trichilinin  /  trichilinin G