Five daucane-type sesquiterpenes isolated from the roots of Ferula songarica Pall. ex Schult. and their anti-gastric cancer activity

Two new daucane-type sesquiterpenes (1-2) and three known compounds (3-5) were isolated from the dried roots of Ferula songarica Pall. ex Schult., their structures were elucidated through comprehensive 1D and 2D NMR spectroscopy, high-resolution electrospray ionisation mass spectrometry (HR-ESI-MS), experimental and calculated (ECD) spectra, and other complementary methods. The MTT assay was employed to evaluate its in vitro antitumor activity. The results indicated that compounds 1, 3 and 4 exhibited potent cytotoxicity against gastric cancer cells with IC₅₀ values of 14.27 ± 0.4 μM, 18.71 ± 1.2 μM and 21.83 ± 3.4 μM, respectively. Compound 2 displayed moderate inhibition with an IC₅₀ value of 45.66 ± 1.9 μM.