Antioxidative activities of galloyl glucopyranosides from the stem-bark of Juglans mandshurica.
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.
Ngoc
Tran Minh
TM
College of Pharmacy, Chungnam National University, Daejeon, Korea.
Hung
Tran Manh
TM
Thuong
Phuong Thien
PT
Kim
Jin-Cheon
JC
Choi
Jae Sue
JS
Bae
KiHwan
K
Hattori
Masao
M
Choi
Chung-Sig
CS
Lee
Joon Seok
JS
Min
Byung-Sun
BS
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
D000975:Antioxidants; D004791:Enzyme Inhibitors; D005960:Glucosides; D008084:Lipoxygenase; D014969:Xanthine Oxidase