Two New Eremophilane‐Type Sesquiterpenoids from the Rhizomes of Ligularia veitchiana ( Hemsl .) Greenm

Two new eremophilane‐type sesquiterpenoids eremophil‐6‐en‐11‐ol ( 1 ) and (7 α ,9 α ,10 α )‐9,10‐epoxy‐eremophilan‐11‐ol ( 2 ), together with a known eremophilane‐type (6 α ,8 α )‐6,8‐dihydroxyeremophil‐7(11)‐en‐12‐oic acid 12,8‐lactone ( 3 ) were isolated from the rhizomes of Ligularia veitchiana. The structures of 1 and 2 were established by spectral analysis including 1 H‐ and 13 C‐NMR, HSQC, HMBC, and HR‐ESI‐MS data. The compounds 1 and 3 were assessed against lung‐cancer (A549) and stomach‐cancer (BCG823) cell lines by the MTT method. The results showed that 1 exhibited significant inhibiting activities on the growth of these cancer cells with IC 50 values between 1–100 μg/ml, whereas compound 3 had no effect on the same cell lines.