Two new flavonol-bis-3,7-glucuronides from Geum rivale L

Abstract Two undescribed flavonol-bis-3,7-O-β-D-glucuronide derivatives - kaempferol-bis-3,7-O-β-D-glucuronide (1) and isorhamnetin-bis-3,7-O-β-D-glucuronide (2) have been isolated from the aerial parts of Geum rivale L. along with three previously described flavonol glucuronide derivatives - quercetin-bis-3,7-O-β-D-glucuronide (3), isorhamnetin-3-O-β-D-glucuronide (4), kaempferol-3-O-β-D-glucuronide (5); and ellagic acid (6), 3-O-methylellagic acid (7), 6"-(4-hydroxycinnamoyl)-astragalin (8) and caffeoylmalic acid (9). All compound structures were elucidated by HR-ESI-MS, extensive 1D- and 2D-NMR experiments along with comparison of their spectroscopic data with those reported in the literature.