Cytotoxic triterpenoids from Antrodia camphorata as sensitizers of paclitaxel†
In an attempt to discover anticancer triterpenoids from the medicinal fungus Antrodia camphorata, a total of 60 triterpenoids (1–60) including 18 new ones (antcamphins M–X, 1–18) were isolated from its dish cultures. The structures of the new compounds were elucidated by extensive NMR and HRESIMS data analyses. The absolute configurations were established by the modified Mosher's method, chemical transformation, or X-ray crystallographic data analysis. The cytotoxic activities of 1–60, together with previously reported compounds 61–81, were evaluated using four human cancer cell lines (HL60, U251, SW480, and MCF-7 cells). Compound 57 exhibited potent activities against all the four cell lines with IC50 values of 2.6, 8.2, 2.5, and 4.6 μM, respectively. Moreover, the combination of 10 and 69 (20 μM) could remarkably enhance their cytotoxic activities against the HL60 cells of paclitaxel (10 nM), with inhibition rates increasing from 19.6% to 58.2% and 70.6%, respectively.