Antioxidative flavonol glycosides from the flowers of Abelmouschus manihot

Bioassay-guided fractionation led to the isolation of six new flavonol glycosides, floramanosides A (1), B (2), C (3), D (4), E (5), and F (6), from the flowers of Abelmouschus manihot. Their structures were elucidated by chemical and spectroscopic methods (UV, IR, HRESI-TOF-MS, 1D- and 2D-NMR). Activity screening results showed that the compounds had 2,2-diphenyl-1-picrylhydrazyl scavenging and aldose reductase inhibitory activities.