title: Enzymatic synthesis and antioxidant properties of poly(rutin).
abstract: Rutin, quercetin-3-rutinoside, is one of the most famous glycosides of flavonoid and widely present in many plants. In this study, we performed an oxidative polymerization of rutin using Myceliophthora laccase as catalyst in a mixture of methanol and buffer to produce a flavonoid polymer and evaluated antioxidant properties of the resultant polymer. Under selected conditions, the polymer with molecular weight of several thousands was obtained in good yields. The resulting polymer was readily soluble in water, DMF, and DMSO, although rutin monomer showed very low water solubility. UV measurement showed that the polymer had broad transition peaks around 255 and 350 nm in water, which were red-shifted in an alkaline solution. Electron spin resonance (ESR) measurement showed the presence of a radical in the polymer. The polymer showed greatly improved superoxide scavenging activity and inhibition effects on human low-density lipoprotein (LDL) oxidation initiated by 2,2'-azobis(2-amidinopropane)dihydrochloride (AAPH), compared with the rutin monomer. The polymer also protected endothelial cells from oxidative injury induced by AAPH as a radical generator with a much greater effect than the rutin monomer.
authors.affiliation: Department of Materials Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 606-8501, Japan.
authors.forename: Motoichi
authors.initials: M
authors.lastname: Kurisawa
authors.forename: Joo Eun
authors.initials: JE
authors.lastname: Chung
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Uyama
authors.forename: Shiro
authors.initials: S
authors.lastname: Kobayashi
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000138:chemical synthesis* / Q000494:pharmacology*; D002417:Cattle; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism; D016166:Free Radical Scavengers / Q000138:chemical synthesis / Q000494:pharmacology; D042845:Laccase / Q000378:metabolism*; D008077:Lipoproteins, LDL / Q000378:metabolism; D010084:Oxidation-Reduction / Q000187:drug effects; D018384:Oxidative Stress / Q000187:drug effects; D011108:Polymers / Q000138:chemical synthesis / Q000494:pharmacology*; D012431:Rutin / Q000031:analogs & derivatives / Q000737:chemistry / Q000494:pharmacology*; D012995:Solubility
chemical_list: D000975:Antioxidants; D016166:Free Radical Scavengers; D008077:Lipoproteins, LDL; D011108:Polymers; D012431:Rutin; D042845:Laccase