Two new terpenoid benzoates with antitumor activity from the roots of Ferula dissecta.

Two new sesquiterpene benzoates, syreiteate A (1) and syreiteate B (2), were isolated from the roots of Ferula dissecta (Ledeb.) Ledeb. Their structures were elucidated by extensive spectroscopic methods including 1D ((1)H and (13)C) NMR, 2D (HSQC, HMBC, DQF-COSY, and NOESY) NMR, and ESI-TOF-MS. Their configurations were determined on the basis of the analysis of the coupling constants, NOESY correlations, and circular dichroism spectrum. Compounds 1 and 2 showed potent growth inhibitory activity against cervical cancer HeLa cell line with the IC50 values of 13.2 and 19.3 µM, respectively.