Triterpene Saponins from Cyclamen trocopteranthum

Two new triterpene saponins (1-2) together with three known saponins, deglucocyclamin I (3), cyclamin (4), and mirabilin (5), were isolated from the tubers of Cyclamen trocopteranthum. They were elucidated as 3 beta-O-{4-O-[3-hydroxyl-3-methylglutaryl]-beta-D-xylopyranosyl-(1 -> 2)-beta-D-glucopyranosyl-(1 -> 4)-[beta-D-glucopyranosyl-(1 -> 2)]-alpha-L-arabinopyranosyl}-16 alpha-hydroxy-13 beta,28-epoxy-oleanan-30-al (1) and 3 beta-O-{4-O-[3-hydroxyl-methylglutaryl]-beta-D-xylopyranosyl-(1 -> 2)-[beta-D-glucopyranosyl-(1 -> 6)]-beta-D-glucopyranosyl-(1 -> 4)-[beta-D-glucopyranosyl-(1 -> 2)]-alpha-L-arabinopyranosyl}-16 alpha-hydroxy-20,30-lactone-olean-12-ene (2). Their structures were characterized mainly by a combination of 1D- and 2D-NMR techniques ((1)H-(1)H COSY, TOCSY, NOESY, HSQC, and HMBC) and mass spectroscopy. Saponins 1, 3, and 4 showed a weak cytotoxic activity when tested HT-29 and HCT 116 tumor colon cancer cells.