Three New C21 Steroidal Glycosides from Roots of Cynanchum otophyllum

ObjectiveTo investigate the chemical structures of glycosides in the roots of Cynanchum otophyllum (Asclepiadaceae) and to find new glycosides.MethodsThe total glycosides in the roots of C. olophyllum were separated by silica gel column chromatography. The structures of the resulting compounds were determined by NMR and FAB-MS spectra.ResultsThree C21 steroidal glycosides were separated. Their structures were determined as caudatin 3-O-(4-O-methyl-β-D-cymaropyranosyl)-(1→4)-α-D-oleandropyranosyl-(1→4)-β-D-glucopyranosyl-(1→4)-α-L-rhamnopyranoside (1), caudatin 3-O-β-D-digitoxopyranosyl-(1→4)-α-D-oleandropyranosyl-(1→4)-β-Ddiginopyranosyl-(1→4)-β-D-glucopyranoside (2), and caudatin 3-O-β-D-diginopyranosyl-(1→4)-α-D-oleandropyranosyl-(1→4)-α-D-oleandropyranosyl-(1→4)-β-D-glucopyranoside (3), respectively.ConclusionGlycosides 1–3 are new compounds.