title: Antioxidative effects of phenylethanoids from Cistanche deserticola.
abstract: The acetone-H2O (9:1) extract from the stem of Cistanche deserticola showed a strong free radical scavenging activity. Nine major phenylethanoid compounds were isolated from this extract. They were identified by NMR as acteoside, isoacteoside, 2'-acetylacteoside, tubuloside B, echinacoside, tubuloside A, syringalide A 3'-alpha-rhamnopyranoside, cistanoside A and cistanoside F. All of these compounds showed stronger free radical scavenging activities than alpha-tocopherol on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and xanthine/xanthine oxidase (XOD) generated superoxide anion radical (O2-.). Among the nine compounds, isoacteoside and tubuloside B, whose caffeoyl moiety is at 6'-position of the glucose, showed an inhibitory effect on XOD. We further studied the effects of these phenylethanoids on the lipid peroxidation in rat liver microsomes induced by enzymatic and non-enzymatic methods. As expected, each of them exhibited significant inhibition on both ascorbic acid/Fe2+ and ADP/NADPH/Fe3+ induced lipid peroxidation in rat liver microsomes, which were more potent than alpha-tocopherol of caffeic acid. The antioxidative effect was found to be potentiated by an increase in the number of phenolic hydroxyl groups in the molecule.
authors.affiliation: Research Institute for Wakan-Yaku (Traditional Sino-Japanese Medicines), Toyama Medical and Pharmaceutical University, Japan.
authors.forename: Q
authors.initials: Q
authors.lastname: Xiong
authors.forename: S
authors.initials: S
authors.lastname: Kadota
authors.forename: T
authors.initials: T
authors.lastname: Tani
authors.forename: T
authors.initials: T
authors.lastname: Namba
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D016166:Free Radical Scavengers; D066298:In Vitro Techniques; D015227:Lipid Peroxidation / Q000187:drug effects; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008862:Microsomes, Liver / Q000187:drug effects / Q000201:enzymology; D010626:Phenylethyl Alcohol / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D010946:Plants, Medicinal / Q000737:chemistry*; D051381:Rats; D017208:Rats, Wistar; D013056:Spectrophotometry, Ultraviolet; D013481:Superoxides / Q000737:chemistry; D014969:Xanthine Oxidase / Q000037:antagonists & inhibitors / Q000378:metabolism
chemical_list: D000975:Antioxidants; D016166:Free Radical Scavengers; D013481:Superoxides; D014969:Xanthine Oxidase; D010626:Phenylethyl Alcohol