Bioactive sesquiterpene coumarins from Ferula pseudalliacea.

One new and five known sesquiterpene coumarins were isolated from the roots of Ferula pseudalliacea. The structures were elucidated by 1D and 2D NMR, and HR-ESIMS data as 4'-hydroxy kamolonol acetate (1), kamolonol (2), szowitsiacoumarin A (3), farnesiferon B (4), farnesiferol C (5), and flabellilobin A (6). The absolute configuration of compounds 1, 2, and 4 was established by comparison of experimental and simulated electronic circular dichroism spectra using time dependence density function theory. 4'-Hydroxy kamolonol acetate and kamolonol showed antibacterial activity against Heliobacter pylori and Staphylococcus aureus at a concentration of 64 µg/mL. Kamolonol, 4'-hydroxy kamolonol acetate, and farnesiferon B displayed a cytotoxic activity in HeLa cells, with an IC50 of 3.8, 4.5, and 7.7 µM, respectively.