Quinoline alkaloids with anti-inflammatory activity from Zanthoxylum avicennae

Zanthoxylum avicennae fruits were traditionally used to treat many inflammatory-related diseases, such as icterohepatitis, nephritis and colitis, which inspired us to explore the active chemicals and pharmacological activity. As a result, ten quinoline alkaloids, including six new ones, avicenines A-F (1-6), were isolated and structurally characterized by solid data. Compounds 1, 7 and 8 were identified as three pairs of enantiomers by chiral HPLC separation, of which 1 was an unusual 6/6/5/5-fused quinoline alkaloid bearing a unique cis-hexahydrofuro[3,2-b]furan moiety. The putative biosynthetic pathway for enantiomeric compounds was also proposed. In addition, compound 6 significantly suppressed the gene expression and secretion of pro-inflammatory cytokines IL-1β and IL-6 in macrophages.