Pregnane glycoside multidrug-resistance modulators from cynanchum wilfordii

Abstract

The methanol-soluble extracts of the roots of Cynanchum wilfordii showed a significant multidrug-resistance-reversing activity, and four known pregnane glycosides were isolated by bioassay-directed fractionation and separation. Their structures were identified as gagaminin 3-O-β-D- cymaropyranosyl(1→4)-β-D-oleandropyranosyl-(1→4)-β-D-cymaropyranosyl- (1→4)-β-D-cymaropyranoside (1), wilfoside K1N (2), wilfoside C1N (3), and cynauricuoside A (4). In particular, compound 1, at a concentration level of 1 μM, was found to completely reverse the multidrug-resistance of KB-V1 and MCF7/ADR cells to adriamycin, vinblastine, and colchicine.