A new cytotoxic cardenolide glycoside, euonymoside A (1), was isolated
from the bark of Euonymus sieboldianus. The structure of 1 was elucid
ated as acovenosigenin A-3-0-beta-D-glucopyranosyl (1-->2)-alpha-L-rha
mnopyranoside. The IC50 values of 1 against A549 (human lung carcinoma
) and SK-OV-3 (human ovary adenocarcinoma) were 0.06 and 0.4 mu g/ml,
respectively.