Two New Eremophilane‐Type Sesquiterpenoids from Ligularia sagitta

Two new eremophilane‐type sesquiterpenoids, sagittacins F and G (1 and 2), together with one known isomer of sagittacin F (3) were isolated from the leaves and stems of Ligularia sagitta. Their structures were elucidated by interpretation of spectroscopic data and the absolute configurations of 1 and 3 were determined by X‐ray spectroscopy. Compound 1 belongs to a rare class of eremophilane‐type sesquiterpenoid featuring an α‐oriented hydroxy group at C‐1. A nitric oxide (NO) production inhibitory assay was applied to evaluate their anti‐inflammatory activities by using LPS‐induced RAW 264.7 cells. Compounds 2 and 3 exhibited modest NO production inhibitions with IC50 values of 45.15±2.72 and 49.83±2.34 μM, respectively.