Cardiac glycosides from Erysimum cheiranthoides

Three new cardiac glycosides named cheiranthoside VIII (1), cheiranthoside IX (2) and cheiranthoside X (3) were isolated from the seeds of Erysimum cheiranthoides. Based on spectroscopic data, the structures of 1-3 were characterized as strophanthidin 3-O-beta-D-glucopyranosyl-(1-->4)-beta-D-antiaropyranoside, cheiranthidin 3-O-beta-D-glucopyranosyl-(1-->4)-beta-D-boiviopyranoside and cheiranthidin 3-O-alpha-L-rhamnopyranosyl-(1-->4)-beta-D-digitoxopyranoside, respectively. The aglycone moiety possessing a carboxyl group at C-10 of 2 and 3 was regarded to be determined for the first time.