title: Antioxidative activities of galloyl glucopyranosides from the stem-bark of Juglans mandshurica.
abstract: Two phenolics, 1,2,6-trigalloylglucose (1) and 1,2,3,6-tetragalloylglucose (2), isolated from the stem-bark of Juglans mandshurica were evaluated for their antioxidative activities. The results showed that compounds 1 and 2 exhibited strong scavenging activities against 1,1'-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis-(3-ethylbenzenthiazoline-6-sulphonic) acid (ABTS(*+)), and superoxide radicals (O(2)(*-)), and also had a significant inhibitory effect on lipid peroxidation and low-density lipoprotein (LDL) oxidation. The strong superoxide radical scavenging of 1 and 2 resulted from the potential competitive inhibition with xanthine at the active site of xanthine oxidase (OX). In addition, compounds 1 and 2 displayed significant lipoxygenase inhibitory activity, the mode of inhibition also being identified as competitive. In comparison, the antioxidative activities of compounds 1 and 2, together with gallic acid, indicated that the number of galloyl moieties could play an important role in the antioxidative activity.
authors.affiliation: College of Pharmacy, Chungnam National University, Daejeon, Korea.
authors.forename: Tran Minh
authors.initials: TM
authors.lastname: Ngoc
authors.forename: Tran Manh
authors.initials: TM
authors.lastname: Hung
authors.forename: Phuong Thien
authors.initials: PT
authors.lastname: Thuong
authors.forename: Jin-Cheon
authors.initials: JC
authors.lastname: Kim
authors.forename: Jae Sue
authors.initials: JS
authors.lastname: Choi
authors.forename: KiHwan
authors.initials: K
authors.lastname: Bae
authors.forename: Masao
authors.initials: M
authors.lastname: Hattori
authors.forename: Chung-Sig
authors.initials: CS
authors.lastname: Choi
authors.forename: Joon Seok
authors.initials: JS
authors.lastname: Lee
authors.forename: Byung-Sun
authors.initials: BS
authors.lastname: Min
mesh_terms: D000975:Antioxidants / Q000737:chemistry* / Q000494:pharmacology*; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000494:pharmacology; D005960:Glucosides / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D006801:Humans; D031324:Juglans / Q000737:chemistry*; D015227:Lipid Peroxidation / Q000187:drug effects; D008084:Lipoxygenase / Q000378:metabolism; D015394:Molecular Structure; D024301:Plant Bark / Q000737:chemistry*; D013025:Glycine max / Q000201:enzymology; D013379:Substrate Specificity; D014969:Xanthine Oxidase / Q000037:antagonists & inhibitors / Q000378:metabolism
chemical_list: D000975:Antioxidants; D004791:Enzyme Inhibitors; D005960:Glucosides; D008084:Lipoxygenase; D014969:Xanthine Oxidase