Determination of the α-Tocopherol Inhibition Rate Constant for Peroxidation in Low-Density Lipoprotein
| Autor: | Ginger L Milne, Fernando Antunes, Sean M. Culbertson, Ned A Porter, Christine M Havrilla |
|---|---|
| Rok vydání: | 2002 |
| Předmět: |
Lipid Peroxides
Antioxidant Free Radicals Stereochemistry Radical medicine.medical_treatment alpha-Tocopherol Kinetics Stereoisomerism Toxicology Medicinal chemistry Antioxidants Linoleic Acid chemistry.chemical_compound Reaction rate constant medicine Humans Tocopherol Autoxidation General Medicine Lipoproteins LDL Models Chemical chemistry Low-density lipoprotein Liposomes Regression Analysis Thermodynamics lipids (amino acids peptides and proteins) Lipid Peroxidation Oxidation-Reduction |
| Zdroj: | Chemical Research in Toxicology. 15:870-876 |
| ISSN: | 1520-5010 0893-228X |
| DOI: | 10.1021/tx020012t |
| Popis: | This work reports an estimate of the inhibition rate constant (k(inh)) for alpha-tocopherol (alpha-TOH) in low-density lipoproteins (LDL) based on cholesteryl linoleate hydroperoxide products formed during autoxidation of intact lipoproteins. The ratio of cis,trans/trans,trans product hydroperoxides was determined during the consumption of the antioxidant. For a reasonable determination of k(inh) in LDL, the pro-oxidant behavior of alpha-TOH was minimized by oxidizing LDL with an unsymmetrical amphiphilic azo initiator which significantly reduces phase-transfer mediated pro-oxidant effects of alpha-TOH. This initiator delivers a more constant flux of initiator radicals into LDL lipid regions and permits determination of alpha-TOH k(inh) in LDL. Development of a tocopherol-mediated peroxidation (TMP) model and analysis of cholesteryl linoleate hydroperoxide cis,trans/trans,trans product ratios provided an estimated value for the inhibition rate constant of alpha-TOH in a lipoprotein of k(inh) = 5.9 +/- 0.5 x 10(5) M(-)(1) s(-)(1) |
| Databáze: | OpenAIRE |
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