5-Hydroxymethylfurfural derivatives with NO production inhibitory activity from the fruits of Schisandra chinensis.

Five previously unreported 5-hydroxymethylfurfural (5-HMF) derivatives, including chinenfurfurals A (1) and B (2) as 5-HMF-citric acid hybrids and chinenfurfurals C-E (3-5) as 5-HMF oligomers, as well as four known analogues (6-9), were isolated from the fruits of a well-known Chinese herbal species Schisandra chinensis. The structures of these furfural compounds were established by detailed analyses of spectroscopic data especially HRMS and NMR, and it is the first report of furfural type constituents from the title species. The in vitro anti-inflammatory property of them was further evaluated by testing their inhibition against the production of nitric oxide in lipopolysaccharide-activated murine RAW264.7 macrophages, and compound 6 showed moderate activity with an IC50 of 41.2 µM. In addition, compound 6 also suppressed the expression of two inflammation-related proteins, namely, inducible nitric oxide synthase and cyclooxygenase-2.