New Coumarin Derivatives and Other Constituents from the Stem Bark of Zanthoxylum avicennae: Effects on Neutrophil Pro-Inflammatory Responses

Three new coumarin derivatives, 8-formylalloxanthoxyletin (1), avicennone (2), and (Z)-avicennone (3), have been isolated from the stem bark of Zanthoxylum avicennae (Z. avicennae), together with 15 known compounds (4–18). The structures of these new compounds were determined through spectroscopic and MS analyses. Compounds 1, 4, 9, 12, and 15 exhibited inhibition (half maximal inhibitory concentration (IC(50)) values ≤7.65 µg/mL) of superoxide anion generation by human neutrophils in response to formyl-l-methionyl-l-leucyl-l-phenylalanine/cytochalasin B (fMLP/CB). Compounds 1, 2, 4, 8 and 9 inhibited fMLP/CB-induced elastase release with IC(50) values ≤8.17 µg/mL. This investigation reveals bioactive isolates (especially 1, 2, 4, 8, 9, 12 and 15) could be further developed as potential candidates for the treatment or prevention of various inflammatory diseases.