Triterpenoid saponins from Spergularia ramosa

Six new oleanene glycosides were isolated from the MeOH extract of the aerial parts of Spergularia ramosa. They possess gypsogenin or quillaic acid as the aglycons. The disaccharide moiety linked to C-3 of the aglycons is made up of galactose (or glucose) and glucuronic acid (or glucose); the pentasaccharide moiety linked to C-28 is made up of glucose (or galactose), xylose, rhamnose, fucose, and arabinose. Their structures were elucidated by 1D and 2D NMR experiments including H-1-H-1 (DQF-COSY, 1D TOCSY, 2D HOHAHA, ROESY) and H-1-C-13 (HSQC, HMBC) spectroscopy.