Strong dependence of the lipid peroxidation product spectrum whether Fe2+/O2 or Fe3+/O2 is used as oxidant.
Catalytic amounts of Fe2+ or Fe3+ ions are widely applied to induce simulated biological lipid peroxidation reactions. Independently, whether Fe2+ or Fe3+ were used, similar products were obtained. We show in this paper that the product spectrum is indeed very different, whether one ion species, either Fe2+ or Fe3+, is present in excess; thus, decomposition of (13S,9Z,11E) 13-hydroxyperoxy-9, 11-octadecadienoic acid (13S-HPODE) generates in the presence of equimolar amounts of Fe2+ ions mainly the corresponding alcohol (13S, 9Z,11E) 13-hydroxy-9,11-octadecadienoic acid besides 12,13-epoxy-11-hydroxy-9-octadecenoic acid (12,13-epHOD) and 13-oxo-9,11-octa-decadienoic acid (13-KODE), while decomposition of 13S-HPODE with equimolar amounts of Fe3+ produces mainly 12,13-epHOD, hydrolysis products thereof and other oxidized products, e.g., hydroxyoxo acids. In addition, unusually large amounts of aldehydes are formed, e.g., the amount of 4-hydroxy-nonenal was found to exceed that obtained by Fe2+ induced air oxidation for a factor of about 100. Since these further oxidation products are suspected to cause cell damage, liberated Fe3+ ions seem to be responsible for generation of toxic products in inflammatory diseases, e.g., atherosclerosis.
Spiteller
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P
Lehrstuhl Organische Chemie I, Universität Bayreuth, Universitätsstrasse 30, Bayreuth 95440, Germany.
Spiteller
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G
D002855:Chromatography, Thin Layer; D005290:Ferric Compounds; D005296:Ferrous Compounds; D008041:Linoleic Acids / Q000032:analysis; D008042:Linolenic Acids / Q000032:analysis; D015227:Lipid Peroxidation; D008054:Lipid Peroxides / Q000032:analysis; D013058:Mass Spectrometry; D010084:Oxidation-Reduction; D010100:Oxygen
D005290:Ferric Compounds; D005296:Ferrous Compounds; D008041:Linoleic Acids; D008042:Linolenic Acids; D008054:Lipid Peroxides; D010100:Oxygen