title: Antioxidant activities of carotenoids: quantitative relationships between theoretical calculations and experimental literature data.
abstract: Quantitative structure activity relationships (QSARs) are described for the antioxidant activity of series of all-trans carotenoids. The antioxidant activity of the carotenoids is characterised by literature data for (i) their relative ability to scavenge the ABTS*+ radical cation, reflected by the so-called trolox equivalent antioxidant capacity (TEAC) value, (ii) their relative rate of oxidation by a range of free radicals, or (iii) their capacity to inhibit lipid peroxidation in multilamellar liposomes, leading to a decrease in formation of thiobarbituric acid reactive substances (TBARS). All these antioxidant values for radical scavenging action correlate quantitatively with computer-calculated ionisation potentials of the carotenoids. These correlations are observed both when the ionisation potential is calculated as the negative of the energy of the highest occupied molecular orbital (-E(HOMO)) of the molecule, or as the relative change in heat of formation (deltadeltaHF) upon the one-electron oxidation of the carotenoids. The calculations provide a theoretical assay able to characterise the intrinsic electron donating capacity of an antioxidant, in hydrophilic, hydrophobic or artificial membrane environment.
authors.affiliation: Department of Biomolecular Sciences, Agricultural University, Wageningen, The Netherlands.
authors.forename: A E
authors.initials: AE
authors.lastname: Soffers
authors.forename: M J
authors.initials: MJ
authors.lastname: Van Haandel
authors.forename: M G
authors.initials: MG
authors.lastname: Boersma
authors.forename: B
authors.initials: B
authors.lastname: Tyrakowska
authors.forename: C
authors.initials: C
authors.lastname: Laane
authors.forename: I M
authors.initials: IM
authors.lastname: Rietjens
mesh_terms: D000975:Antioxidants / Q000737:chemistry* / Q000494:pharmacology*; D002338:Carotenoids / Q000737:chemistry* / Q000494:pharmacology*; D016166:Free Radical Scavengers / Q000737:chemistry / Q000494:pharmacology; D005609:Free Radicals / Q000737:chemistry; D066298:In Vitro Techniques; D015227:Lipid Peroxidation / Q000187:drug effects; D008956:Models, Chemical; D010084:Oxidation-Reduction; D011789:Quantum Theory; D013329:Structure-Activity Relationship; D013816:Thermodynamics
chemical_list: D000975:Antioxidants; D016166:Free Radical Scavengers; D005609:Free Radicals; D002338:Carotenoids