Triterpene saponins from cyclamen trocopteranthum

Two new triterpene saponins (12) 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-O-{4-O-[3- hydroxyl-3-methylglutaryl] - D-xylopyranosyl-(12) - D-glucopyranosyl-(14)-[-D- glucopyranosyl-(12)] - L-arabinopyranosyl}-16-hydroxy-13,28-epoxy-oleanan-30-al (1) and 3-O-{4-O-[3-hydroxyl-3-methylglutaryl] - D-xylopyranosyl-(12)-[-D- glucopyranosyl-(16)] - D-glucopyranosyl-(14)-[-D-glucopyranosyl-(12)] - L-arabinopyranosyl}-16-hydroxy-20,30-lactone-olean-12-ene (2). Their structures were characterized mainly by a combination of 1D- and 2DNMR techniques ( ¹H-¹H COSY, TOCSY, NOESY, HSQC, and HMBC) and mass spectroscopy. Saponins 1, 3, and 4 showed a weak cytotoxic activity when tested against HT-29 and HCT 116 tumor colon cancer cells.