title: Antioxidant activity of anthraquinones and flavonoids from flower of Reynoutria sachalinensis.
abstract: Bioassay-guided fractionation of methanol extract of Reynoutria sachalinensis flower using DPPH assay has led to the isolation of three anthraquinones and three flavonoids. Their structures were identified as emodin (1), emodin-8-O-beta-D-glucopyranoside (2), physcion-8-O-beta-D-glucopyranoside (3), quercetin-3-O-alpha-L-arabinofuranoside (4), quercetin-3-O-beta-D-galactopyranoside (5), and quercetin-3-O-beta-D-glucuronopyranoside (6) by comparing their physicochemical and spectral data with those published in literatures. All isolated compounds were evaluated for antioxidant activities with free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging, superoxide radical scavenging and Cu2+-mediated low density lipoprotein (LDL) oxidation assay. The results demonstrated that three flavonoids, 4, 5, and 6 had remarkable antioxidant activities with the IC50 values of 64.3, 54.7, and 46.2 microM (DPPH scavenging), the IC50 values of 6.0, 6.7, and 4.4 microM (superoxide radical scavenging) and the IC50 values of 3.8, 3.2, and 5.4 microM against LDL oxidation, respectively.
authors.affiliation: College of Pharmacy, Chungnam National University, Daejeon 305-764, Korea.
authors.forename: Xinfeng
authors.initials: X
authors.lastname: Zhang
authors.forename: Phuong Thien
authors.initials: PT
authors.lastname: Thuong
authors.forename: WenYi
authors.initials: W
authors.lastname: Jin
authors.forename: Nguyen Duy
authors.initials: ND
authors.lastname: Su
authors.forename: Dai Eun
authors.initials: DE
authors.lastname: Sok
authors.forename: KiHwan
authors.initials: K
authors.lastname: Bae
authors.forename: Sam Sik
authors.initials: SS
authors.lastname: Kang
mesh_terms: D000880:Anthraquinones / Q000302:isolation & purification / Q000494:pharmacology*; D000975:Antioxidants / Q000302:isolation & purification / Q000494:pharmacology*; D008078:Cholesterol, LDL / Q000097:blood; D005419:Flavonoids / Q000302:isolation & purification / Q000494:pharmacology*; D035264:Flowers; D006801:Humans; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology; D019664:Polygonaceae
chemical_list: D000880:Anthraquinones; D000975:Antioxidants; D008078:Cholesterol, LDL; D005419:Flavonoids; D010936:Plant Extracts