Coumarin derivatives from Ferula kuhistanica and their biological activities.

Twenty-five sesquiterpene coumarins, including twelve previously undescribed ones, were isolated from the roots of Ferula kuhistanica Korovin. Their structures were established through comprehensive spectroscopic analysis, NMR, HRESIMS, quantum 13C NMR DP4+ analysis, ECD calculations, and single-crystal X-ray diffraction analysis. This study systematically evaluated the melanogenesis, tyrosinase, anti-inflammatory, and cytotoxic activities of isolates. Kuhistanin B (1) significantly, promoted melanin synthesis (157.8% ± 1.8%) and increased tyrosinase activity (147.9% ± 10.5%) at 50 μM in B16F10 cells. An MTT assay confirmed no significant cytotoxicity at this concentration (cell viability = 100.0% ± 1.6%). In the anti-inflammatory assay, ethyl galbanate (17) and kopeolin (19) showed good activity with IC50 values of 7.1 ± 0.9 and 9.4 ± 3.1 μM. Isosamarcandin (14) and kopeolin (19) exhibited good cytotoxicity against HT-29 cells with IC50 values of 9.82 ± 0.51 and 7.64 ± 0.41 μM, respectively.