Cytotoxic saponins from Schefflera fagueti.

Six new lupane (1 - 4) and oleanane saponins (5 and 6) were isolated from the aerial parts of Schefflera fagueti Baill. (Araliaceae). Their structures were determined by 2D-NMR spectroscopy (DQF-COSY, 1D-TOCSY, 2D-HOHAHA, 1D-ROESY, HSQC, HMBC). The antiproliferative activity of compounds 1 - 6 and of their prosapogenins (1a - 6a) was evaluated using three continuous murine and human culture cell lines J774, HEK-293, WEHI-164. Oleanane saponins 5 and 6 were the most active, showing significant inhibitory effects on all cell lines, while their prosapogenins 5a and 6a demonstrated minor activity.