A new bufadienolide with cytotoxic activity from the Chinese traditional drug Ch'an Su

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 3-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 nmolL-1.The relationships between structure and activity are discussed.