Novel flavonoids from the leaves of Actinidia valvata Dunn: structural elucidation and antioxidant activity

Two novel flavonoids, kaempferol 3- O- α-L-rhamnopyranosyl (1-3) (2,4-di- O-acetyl-α-L-rhamnopyranosyl) (1-6) β-D-galactopyranoside (1) and kaempferol 3- O-α-L-rhamnopyranosyl (1-3) (4-O-acetyl-α-L-rhamnopyranosyl) (1-6) β-D-galactopyranoside (2), along with three known ones, kaempferol-3- O-β-D-galactopyranoside (3), kaempferol (4), and 7-hydroxychromone (5), have been isolated from the leaves of Actinidia valvata Dunn, and their structures were elucidated based on spectroscopic methods. Compounds 1-3 exhibited dose-dependent activity in scavenging 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radicals, superoxide anion radicals, and hydroxyl radicals, and inhibited lipid peroxidation of mouse liver homogenate IN VITRO.