title: High performance liquid chromatography/electron spin resonance/mass spectrometry analyses of radicals formed in an anaerobic reaction of 9- (or 13-) hydroperoxide octadecadienoic acids with ferrous ions.
abstract: The oxidation of linoleic acid yields isomeric acyl hydroperoxides. In order to clarify the relation between the lipid peroxide-derived radicals and the toxicity of the lipid peroxide, identification of the lipid-derived radicals is essential. In this paper, high performance liquid chromatography/electron spin resonance/mass spectrometry (HPLC/EPR/MS) analysis of the radicals was performed for the reaction mixture containing 9-hydroperoxy-(10E,12E)-octadeca-10,12-dienoic acid (9EE-OOH) [or 13-hydroperoxy-(9Z,11E)-octadeca-9,11-dienoic acid (13ZE-OOH)] under an aerobic condition or an anaerobic condition. Following radicals were identified from 9EE-OOH (or 13EZ-OOH) by using high performance liquid chromatography/electron spin resonance spectrometry (HPLC/EPR) and HPLC/EPR/MS: pentyl radical and isomers of epoxylinoleic acid radicals from 13EZ-OOH under an anaerobic condition; 7-carboxyheptyl radical and pentyl radical from 13EZ-OOH under an aerobic condition; 7-carboxyheptyl radical and pentyl radical from 9EE-OOH under an aerobic condition; 7-carboxyheptyl radical from 9EE-OOH under an anaerobic condition. These results showed that the formation of the respective radical species depends on oxygen concentration in the reaction mixtures to a great extent.
authors.affiliation: Department of Chemistry, Wakayama Medical University, 811-1 Kimiidera, Wakayama 641-8509, Japan. chem1@wakayma-med.ac.jp <chem1@wakayma-med.ac.jp>
authors.forename: Hideo
authors.initials: H
authors.lastname: Iwahashi
authors.forename: Tomihiro
authors.initials: T
authors.lastname: Hirai
authors.forename: Kazumasa
authors.initials: K
authors.lastname: Kumamoto
mesh_terms: D000693:Anaerobiosis; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D005231:Fatty Acids, Unsaturated / Q000737:chemistry*; D005296:Ferrous Compounds / Q000032:analysis* / Q000737:chemistry; D005609:Free Radicals / Q000032:analysis* / Q000737:chemistry; D008054:Lipid Peroxides / Q000737:chemistry*; D013058:Mass Spectrometry / Q000379:methods*; D008956:Models, Chemical
chemical_list: D005231:Fatty Acids, Unsaturated; D005296:Ferrous Compounds; D005609:Free Radicals; D008054:Lipid Peroxides; C027369:octadecadienoic acid