Unveiling the anti-vitiligo, anti-inflammatory, and antitumor activities of sesquiterpene coumarins isolated from Ferula kuhistanica

Six undescribed bicyclic sesquiterpene coumarins, kuhistanin A, ferukrin isovalerate, 9'β,12'α - ferukrin isovalerate, (17'E)- 9'α, 12'β - isomarcandin, (17'Z)- 9'α, 12'β - isomarcandin and (17'E) - isomarcandin, together with nine known ones were isolated from the roots of Ferula kuhistanica Korovin. The structures of them were elucidated using NMR and HRESIMS data analysis. The relative configurations of the isolates were confirmed by NOE correlations and NMR calculation. The absolute configurations of them were confirmed by X-ray diffraction analysis and ECD calculation. Anti-vitiligo, anti-inflammatory and cytotoxicity of the isolates were tested. Acetyl feselol, feselol, ferusingensine I and farnesiferol A significantly increased the melanin content at the concentration of 10 μM. (17'E) - 9'α, 12'β - isomarcandin exhibited strong cytotoxicity against HT-29 cell line with IC