Cytotoxic cardenolides from woods of Euonymus alata.

Three cytotoxic cardenolides, acovenosigenin A 3-O-alpha-L-ramnopyranoside (1), euonymoside A (2) and euonymusoside A (3), were isolated from the woods of Euonymus alata (Celastraceae). The chemical structure of a new cardenolide, euonymusoside A (3) has been elucidated on the basis of extensive spectral analysis and enzymic hydrolysis to be acovenosigenin A (1 beta, 3 beta, 14 beta-trihydroxy-5 beta-cardenolide) 3-O-beta-D-glucopyranosyl (1-->6)-beta-D-glucopyranosyl(1-->4)-alpha-L-rhamnopyranoside. All three showed potent cytotoxic activity against some neoplastic cell lines.