New coumarins and anti-inflammatory constituents from Zanthoxylum avicennae

Zanthoxylum avicennae is commercially used as healthcare products for the improvement of chronic hepatitis and rheumatism. Its fruit is also used as a spice. Five new coumarins, 5′-methoxyauraptene (1), 6,5′-dimethoxyauraptene (2), 5′-methoxycollinin (3), 7-((2′E,5′E)-7′-methoxy-3′,7′-dimethylocta-2′,5′-dienyloxy)coumarin (4), and 6-methoxy-7-((2′E,5′E)-7′-methoxy-3′,7′-dimethylocta-2′,5′-dienyloxy)coumarin (5), have been isolated from the leaves of Z. avicennae, together with 15 known compounds (6–20). The structures of these new compounds were determined through spectroscopic and MS analyses. Compounds 6, 9–15, and 18 exhibited inhibition (IC50 ⩽ 8.29 μg/ml) of superoxide anion generation by human neutrophils in response to formyl-l-methionyl-l-leucyl-l-phenylalanine/cytochalasin B (fMLP/CB). Compounds 6, 10, 12, 14, and 18 inhibited fMLP/CB-induced elastase release with IC50 values ⩽6.30 μg/ml.