Antioxidant Mechanism of Carnosic Acid: Structural Identification of Two Oxidation Products
Authors:
- 13 October 2001
- journal article
- research article
- Published by American Chemical Society (ACS) in Journal of Agricultural and Food Chemistry
- Vol. 49 (11) , 5560-5565
Abstract
To determine the antioxidant mechanism of food phenolics against the oxidation of food components, the reaction of carnosic acid, an antioxidative constituent of the popular herbs sage and rosemary, was investigated in the presence of ethyl linoleate and the radical oxidation initiator 2,2‘-azobis(2,4-dimethylvaleronitrile). During this process, carnosic acid was oxidized to an o-quinone and a hydroxy p-quinone, the chemical structures of which were confirmed by physical and chemical techniques. From a quantitative time course analysis of the production of these quinones, an antioxidant mechanism of carnosic acid is proposed, consisting of the oxidative coupling reaction with the peroxyl radical at the 12- or 14-position of carnosic acid and subsequent degradation reactions. Keywords: Carnosic aid; antioxidant mechanism; radical termination; sage; Labiatae; o-quinoneKeywords
This publication has 6 references indexed in Scilit:
- Antioxidant activity of lipid‐soluble phenolic diterpenes from rosemaryJournal of the American Oil Chemists' Society, 1996
- Iron-Catalyzed Oxidation of (+)-Catechin in Model SystemsJournal of Agricultural and Food Chemistry, 1996
- Antioxidative constituents ofRosmarinus officinalis andSalvia officinalisEuropean Food Research and Technology, 1992
- Phenolic antioxidantsCritical Reviews in Food Science and Nutrition, 1992
- Oxidation of vitamin E: evidence for competing autoxidation and peroxyl radical trapping reactions of the tocopheroxyl radicalJournal of the American Chemical Society, 1990
- Tetrasodio Bis-β-diketones. Dicondensations with Electrophilic Compounds1The Journal of Organic Chemistry, 1965