Antioxidant properties and free radical-scavenging reactivity of a family of hydroxynaphthalenones and dihydroxyanthracenones.
This study was undertaken to investigate the free radical-scavenging and antioxidant activities of various structurally related hydroquinones including hydroxynaphthalenones and dihydroxyanthracenones. Electron spin resonance spectroscopy and spin trapping techniques were used to evaluate the ability of hydroquinones to scavenge hydroxyl, diphenylpicrylhydrazyl, and galvinoxyl radicals. In addition, the oxygen radical absorbing capacity assay using fluorescein (ORAC-FL) was used to obtain the relative antioxidant capacity of these radicals. The rate constants of the first H atom abstraction by 2,2-diphenyl-2-picrylhydrazyl (k(2)), were obtained under pseudo-first-order conditions. The free radical-scavenging activities and k(2) values discriminate well between hydroxynaphthalenones and dihydroxyanthracenones, showing that the latter have better antioxidant properties. The aforementioned experimental data agree with quantum-chemical results demonstrating the relevance of intramolecular H bonding to radical-scavenging activities.
Rodríguez
Jorge
J
Departamento de Química Inorgánica y Analítica, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Chile.
Olea-Azar
Claudio
C
Cavieres
Cristina
C
Norambuena
Ester
E
Delgado-Castro
Tomás
T
Soto-Delgado
Jorge
J
Araya-Maturana
Ramiro
R
D000818:Animals; D000873:Anthracenes / Q000737:chemistry* / Q000494:pharmacology; D000975:Antioxidants / Q000737:chemistry* / Q000494:pharmacology; D045744:Cell Line, Tumor; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods; D016166:Free Radical Scavengers / Q000737:chemistry* / Q000494:pharmacology; D006860:Hydrogen Bonding; D007700:Kinetics; D051379:Mice; D015394:Molecular Structure; D009281:Naphthalenes / Q000737:chemistry* / Q000494:pharmacology; D010100:Oxygen / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000737:chemistry / Q000378:metabolism; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D000873:Anthracenes; D000975:Antioxidants; D016166:Free Radical Scavengers; D009281:Naphthalenes; D017382:Reactive Oxygen Species; D010100:Oxygen