title: Antioxidant activity of a catechol derived from abietic acid.
abstract: The demand for novel effective antioxidant-based drugs has led to the synthesis and evaluation of the antioxidant potential in several molecules derived from natural compounds. In this work the in vitro antioxidant activity of an abietic acid-derived catechol (methyl 11,12-dihydroxyabietate-8,11,13-trien-18-oate, MDTO) was evaluated. This substance, possessing important biological properties, is similar to carnosic acid, a natural antioxidant from rosemary or sage leaves. Aiming to understand the antioxidant activity of MDTO, the energetics of its O-H bond, using time-resolved photoacoustic calorimetry (TR-PAC), was investigated. On energetic grounds it is predicted that MDTO is a good free radical scavenger, although its activity is lower than that of quercetin, a very effective antioxidant, which was used for comparison. In agreement with these predictions, the DPPH(*) and ABTS(*+) radical scavenging activities are lower than those of quercetin. In addition, MDTO also reacts with HOCl, a powerful proinflammatory oxidant produced by activated neutrophils, and protects liposomes against iron-ascorbate-induced oxidation. The discussion of these results foresees potential applications of MDTO as an antioxidant.
authors.affiliation: Departamento de Química e Bioquímica and Centro de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal.
authors.forename: Gonçalo C
authors.initials: GC
authors.lastname: Justino
authors.forename: Catarina F
authors.initials: CF
authors.lastname: Correia
authors.forename: Lurdes
authors.initials: L
authors.lastname: Mira
authors.forename: Rui M
authors.initials: RM
authors.lastname: Borges Dos Santos
authors.forename: José A
authors.initials: JA
authors.lastname: Martinho Simões
authors.forename: Ana M
authors.initials: AM
authors.lastname: Silva
authors.forename: Célia
authors.initials: C
authors.lastname: Santos
authors.forename: Bárbara
authors.initials: B
authors.lastname: Gigante
mesh_terms: D045784:Abietanes / Q000737:chemistry*; D000975:Antioxidants / Q000494:pharmacology*; D052160:Benzothiazoles; D001713:Biphenyl Compounds; D002151:Calorimetry / Q000379:methods; D002396:Catechols / Q000737:chemistry* / Q000494:pharmacology*; D016166:Free Radical Scavengers / Q000737:chemistry; D015227:Lipid Peroxidation / Q000187:drug effects; D008081:Liposomes / Q000737:chemistry; D010616:Phenanthrenes / Q000737:chemistry*; D010851:Picrates; D013451:Sulfonic Acids; D013816:Thermodynamics
chemical_list: D045784:Abietanes; D000975:Antioxidants; D052160:Benzothiazoles; D001713:Biphenyl Compounds; D002396:Catechols; D016166:Free Radical Scavengers; D008081:Liposomes; D010616:Phenanthrenes; D010851:Picrates; D013451:Sulfonic Acids; C002502:2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid; C004931:1,1-diphenyl-2-picrylhydrazyl; C034221:catechol; C023710:abietic acid