title: Amplification of antioxidant activity of catechin by polycondensation with acetaldehyde.
abstract: Catechin exhibits numerous biological and pharmacological effects attributed to antioxidant action. The synthetic poly(catechin)s condensed through acetaldehyde with different molecular weights were assessed in terms of antioxidant activity and enzyme inhibitory activity on the basis of a catechin repeating unit and compared with monomeric catechin. The poly(catechin)s showed great amplification of superoxide scavenging activity, xanthine oxidase (XO) inhibitory activity, and inhibition effects on human low-density lipoprotein oxidation initiated by 2,2'-azobis(2-amidinopropane)dihydrochloride (AAPH) as a radical generator on the catechin unit level, compared to monomeric catechin: these activities were proportional to their molecular weights. The reducing power of the polymer was lower than that of monomeric catechin, which decreased with increasing the molecular weight. The polymer also protected endothelial cells from oxidative injury induced by AAPH, with a greater effect expressed on a catechin unit basis than that of the monomer. These results demonstrate that the poly(catechin)s are more potent antioxidant agents and enzyme inhibitors.
authors.affiliation: Department of Materials Chemistry, Graduate School of Engineering, Kyoto University, 615-8510, Japan.
authors.forename: Joo Eun
authors.initials: JE
authors.lastname: Chung
authors.forename: Motoichi
authors.initials: M
authors.lastname: Kurisawa
authors.forename: Young-Jin
authors.initials: YJ
authors.lastname: Kim
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Uyama
authors.forename: Shiro
authors.initials: S
authors.lastname: Kobayashi
mesh_terms: D000079:Acetaldehyde / Q000737:chemistry; D000975:Antioxidants / Q000737:chemistry* / Q000494:pharmacology*; D002392:Catechin / Q000737:chemistry* / Q000494:pharmacology; D002470:Cell Survival / Q000187:drug effects; D042783:Endothelial Cells / Q000187:drug effects; D004791:Enzyme Inhibitors; D006801:Humans; D015227:Lipid Peroxidation / Q000187:drug effects; D008077:Lipoproteins, LDL / Q000378:metabolism; D011108:Polymers / Q000737:chemistry* / Q000494:pharmacology; D013329:Structure-Activity Relationship; D013481:Superoxides / Q000378:metabolism; D014969:Xanthine Oxidase / Q000037:antagonists & inhibitors
chemical_list: D000975:Antioxidants; D004791:Enzyme Inhibitors; D008077:Lipoproteins, LDL; D011108:Polymers; D013481:Superoxides; D002392:Catechin; D014969:Xanthine Oxidase; D000079:Acetaldehyde