title: Antioxidant effectiveness generated by one or two phenolic hydroxyl groups in coumarin-substituted dihydropyrazoles.
abstract: A cascade operation was designed to synthesize nine coumarin-substituted dihydropyrazoles with only one or two phenolic hydroxyl groups contained. Antioxidant abilities of the obtained compounds were evaluated by inhibiting 2,2'-azobis(2-amidinopropanehydrochloride) (AAPH)-, Cu2+/glutathione (GSH)-, and .OH-induced oxidation of DNA. It was found that less phenolic hydroxyl groups can enhance the abilities of coumarin-substituted dihydropyrazoles to protect DNA against the oxidation. Moreover, these coumarin-substituted dihydropyrazoles were employed to scavenge 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonate) cationic radical (ABTS+.), 2,2'-diphenyl-1-picrylhydrazyl radical (DPPH), and galvinoxyl radical, respectively. It was found that double phenolic hydroxyl groups were more beneficial for enhancing the abilities of coumarin-substituted dihydropyrazoles to quench the aforementioned radicals. Therefore, dihydropyrazole linked with coumarin exhibited powerful antioxidant effectiveness even in the case of less phenolic hydroxyl groups involved.
authors.affiliation: Department of Organic Chemistry, College of Chemistry, Jilin University, Changchun 130021, China.
authors.forename: Gao-Lei
authors.initials: GL
authors.lastname: Xi
authors.forename: Zai-Qun
authors.initials: ZQ
authors.lastname: Liu
mesh_terms: D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology; D003374:Coumarins / Q000737:chemistry*; D005609:Free Radicals / Q000378:metabolism; D010084:Oxidation-Reduction / Q000187:drug effects; D010636:Phenols / Q000737:chemistry*; D011720:Pyrazoles / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D000975:Antioxidants; D003374:Coumarins; D005609:Free Radicals; D010636:Phenols; D011720:Pyrazoles; C030123:coumarin
keywords: Antioxidant; Coumarin; Dihydropyrazole; Free radical; Oxidation of DNA