title: Discerning the antioxidant mechanism of rapanone: A naturally occurring benzoquinone with iron complexing and radical scavenging activities.
abstract: Oxidative stress resulting from iron and reactive oxygen species (ROS) homeostasis breakdown has been implicated in several diseases. Therefore, molecules capable of binding iron and/or scavenging ROS may be reasonable strategies for protecting cells. Rapanone is a naturally occurring hydroxyl-benzoquinone with a privileged chelating structure. In this work, we addressed the antioxidant properties of rapanone concerning its iron-chelating and scavenging activities, and its protective potential against iron and tert-butyl hydroperoxide-induced damage to mitochondria. Experimental determinations revealed the formation of rapanone-Fe(II)/Fe(III) complexes. Additionally, the electrochemical assays indicated that rapanone oxidized Fe(II) and O2-, thus inhibiting Fenton-Haber-Weiss reactions. Furthermore, rapanone displayed an increased 2,2-diphenyl-1-picrylhydrazyl radical scavenging ability in the presence of Fe(II). The above results explained the capacity of rapanone to provide near-full protection against iron and tert-butyl hydroperoxide induced mitochondrial lipid peroxidation in energized organelles, which fail under non-energized condition. We postulate that rapanone affords protection against iron and reactive oxygen species by means of both iron chelating and iron-stimulated free radical scavenging activity.
authors.affiliation: Departamento de Farmacia, Instituto de Farmacia y Alimentos, Universidad de La Habana, Ave. 23 # 21425 e/ 214 y 222, La Coronela, La Lisa, CP 13600, La Habana, Cuba.
authors.forename: Karen
authors.initials: K
authors.lastname: de la Vega-Hernández
authors.affiliation: Departamento de Química-Física, Facultad de Química, Universidad de la Habana, Ave. Zapata y G, Vedado, CP 10400 La Habana, Cuba.
authors.forename: Manuel
authors.initials: M
authors.lastname: Antuch
authors.affiliation: Facultad de Química y Salud, Universidad Técnica de Machala, Ecuador.
authors.forename: Osmany
authors.initials: O
authors.lastname: Cuesta-Rubio
authors.affiliation: Centro de Investigación y Desarrollo de Medicamentos, La Habana, Cuba.
authors.forename: Yanier
authors.initials: Y
authors.lastname: Núñez-Figueredo
authors.affiliation: Centro de Estudio para las Investigaciones y Evaluaciones Biológicas, Instituto de Farmacia y Alimentos, Universidad de La Habana, Calle 222, No. 2317 entre 23 y 31, La Coronela, La Lisa, CP 13600 La Habana, Cuba. Electronic address: gpardo@ifal.uh.cu.
authors.forename: Gilberto L
authors.initials: GL
authors.lastname: Pardo-Andreu
mesh_terms: D016227:Benzoquinones / Q000737:chemistry*; D056831:Coordination Complexes / Q000737:chemistry*; D016166:Free Radical Scavengers / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*
chemical_list: D016227:Benzoquinones; D056831:Coordination Complexes; D016166:Free Radical Scavengers; C054611:rapanone; D007501:Iron
keywords: Antioxidant; Iron; Iron-chelation; Mitochondria; Quinones; Rapanone