A new diacetylated flavonol triglycoside from the aerial parts of Actinidia polygama.

Phytochemical investigation of a methanolic extract of aerial parts Actinidia polygama Miq. led to the isolation of one new diacetylated flavonol triglycoside, kaempferol 3-O-[α-L-rhamnopyranosyl(1→3)-(4-O-acetyl)-O-α-L-rhamnopyranosyl(1→6)-(2-Oacetyl)-O-β-D-galactopyranoside] (1) along with 12 known compounds (2-13). The chemical structures were determined using their spectroscopic data including 1D and 2D NMR. To the best of our knowledge, this is the first time that compounds 2, 4, 6, 7, 8, 9, 12 and 13 are isolated from this plant. All purified compounds were tested for free radical scavenging effect using DPPH and ABTS assays. Our results showed that compounds 4, 6, 7 and 13 have potential antioxidative effect for scavenging both DPPH and ABTS radicals that are comparable with those of ascorbic acid used as positive control, whereas compounds 1 and 2, which are di- and mono- acetylated flavonol triglycoside respectively, were not found to be potent scavengers of free radicals.