Anti-inflammatory Constituents from the Aerial Parts of Iris minutiaurea

Phytochemical investigation of the methanol extract of the aerial parts of Iris minutiaurea (Iridaceae) using column chromatography led to the isolation of a new xanthone glycoside, 1-hydroxy-3,5-dimethoxy-xanthone-6-O-β-D-glucoside (1), together with one known flavonoid glycoside (2). The structure of this new compound was elucidated by analysis of spectroscopic, including 1D (1H, 13C), 2D NMR (COSY, HMQC, HMBC), and high resolution fast atom bombardment mass spectrometric (HR-FAB-MS) data and enzyme hydrolysis. We found that compounds 1 and 2 significantly suppressed production of NO, and pro-inflammatory cytokine in LPS-induced RAW264.7 cells. These results suggest that compound 1 and 2 have anti-inflammatory activity related with production of TNF-α, IL-6, IL-1β, and NO in macrophages, and then compound 1 were more efficient than compound 2 in lowering the level of proinflammatory cytokine.