A new bufadienolide with cytotoxic activity from the Chinese traditional drug Ch'an Su / 中国天然药物

AIM@#To study the bufadienolides in the Chinese traditional drug "Ch'an Su" and their cytotoxic activity.@*METHOD@#Various chromatographic techniques were used to isolate the constituents, and their structures were elucidated through physical and spectroscopic data.@*RESULTS@#Twenty compounds were isolated, and eighteen were evaluated in vitro for their cytotoxic activity against A-549 and K-562 cells.@*CONCLUSION@#Compound 1 (bufalin 3β-acrylic ester) was a new bufadienolide and exhibited the most potent activity against the two tumor cell lines with IC50 values of 7.16 and 6.83 nmol · L(-1). The relationships between structure and activity are discussed.