Cytotoxic and apoptosis-inducing activities against human lung cancer cell lines of cassaine diterpenoids from the bark of Erythrophleum fordii.
Ha MT, Tran MH, Phuong TT, Kim JA, Woo MH, Choi JS, Lee S, Lee JH, Lee HK, Min BS.
A phytochemical investigation into the bark of Erythrophleum fordii yielded four new compounds, two new cassaine diterpenoids (erythrofordin T and U, 1 and 2) and two new cassaine diterpenoid amines (erythroformine A and B, 6 and 7), as well as nine known compounds. We report for the first time the isolation of erythrofordin V (3) from a natural source and that of the remaining eight known diterpenoids (4-5, 8-13) from E. fordii. All structures were elucidated using spectroscopic analysis. Cytotoxic activity of the isolated compounds (1-13) was examined in vitro against three non-small cell lung cancer cell lines (A549, NCI-H1975, and NCI-H1229) using the MTT assay. Cassaine diterpene amines (6-10, 12, 13) exhibited potent cytotoxic activity against all three cell lines with IC50 values between 0.4μM and 5.9μM. Erythroformine B (7) significantly induced apoptosis in all three cancer cells in a concentration-dependent manner.