New isoflavones and anti-inflammatory constituents from the fruits of Cnidium monnieri

The fruit of Cnidium monnieri is commercially used as healthcare products for the improvement of impotence and skin diseases. Three new coumarins, 3'-O-methylmurraol (1), rel-(1'S,2'S)-1'-O-methylphlojodicarpin (2), and (1'S,2'S)-1'-O-methylvaginol (3), have been isolated from the fruits of C. monnieri, together with 14 known compounds (4-17). The structures of these new compounds were determined through spectroscopic and MS analyses. Compounds 1, 4-12, and 14-17 exhibited inhibition (IC₅₀ ≤ 7.31 μg/mL) of superoxide anion generation by human neutrophils in response to formyl-L-methionyl-L leucyl-L-phenylalanine/cytochalasin B (fMLP/CB). Compounds 7, 9-11, 15, and 17 inhibited fMLP/CB-induced elastase release with IC₅₀ values ≤7.83 μg/mL. This investigation reveals that bioactive isolates (especially 6, 7, 14, and 17) could be further developed as potential candidates for the treatment or prevention of various inflammatory diseases.