title: Coumarin-fused coumarin: antioxidant story from N,N-dimethylamino and hydroxyl groups.
abstract: Two coumarin skeletons can form chromeno[3,4-c]chromene-6,7-dione by sharing with the C ═ C in lactone. The aim of the present work was to explore the antioxidant effectiveness of the coumarin-fused coumarin via six synthetic compounds containing hydroxyl and N,N-dimethylamino as the functional groups. The abilities to quench 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonate) cationic radical (ABTS(+•)), 2,2'-diphenyl-1-picrylhydrazyl radical (DPPH), and galvinoxyl radical revealed that the rate constant for scavenging radicals was related to the amount of hydroxyl group in the scaffold of coumarin-fused coumarin. But coumarin-fused coumarin was able to inhibit DNA oxidations caused by (•)OH, Cu(2+)/glutathione (GSH), and 2,2'-azobis(2-amidinopropane hydrochloride) (AAPH) even in the absence of hydroxyl group. In particular, a hydroxyl and an N,N-dimethylamino group locating at different benzene rings increased the inhibitory effect of coumarin-fused coumarin on AAPH-induced oxidation of DNA about 3 times higher than a single hydroxyl group, whereas N,N-dimethylamino-substituted coumarin-fused coumarin possessed high activity toward (•)OH-induced oxidation of DNA without the hydroxyl group contained. Therefore, the hydroxyl group together with N,N-dimethylamino group may be a novel combination for the design of coumarin-fused heterocyclic antioxidants.
authors.affiliation: Department of Organic Chemistry, College of Chemistry, Jilin University, No. 2519 Jiefang Road , Changchun 130021, China.
authors.forename: Gao-Lei
authors.initials: GL
authors.lastname: Xi
authors.affiliation: Department of Organic Chemistry, College of Chemistry, Jilin University, No. 2519 Jiefang Road , Changchun 130021, China.
authors.forename: Zai-Qun
authors.initials: ZQ
authors.lastname: Liu
mesh_terms: D000578:Amidines / Q000737:chemistry; D000975:Antioxidants / Q000737:chemistry*; D003300:Copper / Q000737:chemistry; D003374:Coumarins / Q000737:chemistry*; D004247:DNA / Q000737:chemistry; D016166:Free Radical Scavengers / Q000737:chemistry; D005609:Free Radicals / Q000737:chemistry; D005978:Glutathione / Q000737:chemistry; D017665:Hydroxyl Radical / Q000737:chemistry; D016877:Oxidants; D010084:Oxidation-Reduction
chemical_list: D000578:Amidines; D000975:Antioxidants; D003374:Coumarins; D016166:Free Radical Scavengers; D005609:Free Radicals; D016877:Oxidants; D017665:Hydroxyl Radical; C046728:2,2'-azobis(2-amidinopropane); D003300:Copper; D004247:DNA; C030123:coumarin; D005978:Glutathione
keywords: DNA oxidation; antioxidant; coumarin-fused coumarin; free radical