Napifera A-F, six previously undescribed sesquiterpenoid derivatives from the roots of Crepis napifera.

Phytochemical investigation of the roots of Crepis napifera yielded six previously undescribed sesquiterpenoid derivatives, napifera A-F (1-5 and 16), together with 23 known compounds. The new compounds comprised five non-glycosylated sesquiterpenoid-derived acids (1-5) and one acylated sesquiterpene lactone glucoside (16). Their structures were elucidated through spectroscopic and computational analyses. All isolates were evaluated for cytotoxicity against five tumor cell lines and antibacterial activity against Staphylococcus aureus. Compound 11 showed an IC50 of 14.38 ± 0.57 μM against HeLa cells and an MIC of 12.5 μg/mL against S. aureus. These findings expand the known structural diversity of sesquiterpenoids from C. napifera.