Flavonoids from the aerial parts of Lespedeza cuneata

The chemical constituents of the aerial parts of Lespedeza cuneata (Dum. Cour.) G. Don were investigated using chromatographic techniques, such as silica gel, reversed phase MPLC and preparative HPLC. Five compounds were isolated and their structures were elucidated by spectroscopic data and physicochemical properties, which were identified as 7-O-glucosyllaburnetin (1), kaempferol-3-O-β-D-galactopyranoside (2), kaempferol-3-O-α-L-rhamnoside (3), vitexin (4), and isovitexin (5). Among those, compound 1 is a new compound, compounds 2-3 were isolated from this plant for the first time. Compounds 1-5 were tested for their anti-ulcerative colitis activity by dual luciferase report gene assay targeting xbp1. Compared with control group, compound 1 showed a certain activity on activating the transcription of xbp1, with its relative activating ratio being 1.80 times.