Novel norlignan glucosides from rhizomes of Curculigo sinensis Original Research Article

Eight norlignan glucosides, including two novel skeleton-rearranged compounds, sinenside A (1) and B (2), and six known compounds, crassifoside D (3), capituloside (4), a mixture of (1S,2R)-1-O-methylnyasicoside (5), (1R,2R)-1-O-methylisonyasicoside (6), and a mixture of (1S,2R)-1-O-methylcurculigine (7) and (1R,2R)-1-O-methylisocurculigine (8), were isolated from the rhizomes of Curculigo sinensis. Compounds 3–8 were isolated for the first time from this plant. Structures of the isolated compounds were established by spectroscopic analysis, including UV, IR, HRESI-MS, and 1D/2D NMR, and hydrolysis experiments. The free radical scavenging activity of the isolated compounds was evaluated by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. All the isolated compounds showed strong radical scavenging activities.