Oxidation of Methyl Linoleate in Triton X‐100 Micelles Initiated by Lipid‐soluble Initiator 2,2′‐Azobis (2,4‐dimethylvaleronitrile)

• Published in: ChemistrySelect (Weinheim) 2023-07, Vol.8 (25), p.n/a
• Main Authors: Moskalenko, Ivan V., Borodin, Leonid I., Novikov, Alexander S.
• Format: Article
• Language: English
• Subjects: antioxidant test systems; DFT; lipid peroxidation; micelles; radical chain oxidation
• ISSN: 2365-6549; 2365-6549
• DOI: 10.1002/slct.202301357

This article discusses the oxidation of methyl linoleate in micelles, initiated by the lipid‐soluble initiator 2,2′‐azobis (2,4‐dimethylvaleronitrile) (AMVN). It was shown that the rate constant (ki) is initiated in micelles for AMVN significantly lower than the known rate constant of initiation in true solutions. This can be explained by the reduced probability of AMVN radicals leaving the cage and an increase in the rate of chain termination between initiator radicals under conditions of low oxygen content. This conclusion was confirmed by quantum chemical calculations. Surprisingly, when determining the AMVN initiation rate constant for the consumption of nitroxyl radicals (>NO⋅), the ki depends on the concentration >NO⋅, this is due to the dependence of the probability of the nitroxyl radical and initiator radicals in micelles meeting on their concentration. Upon initiation of AMVN, no hydroperoxyl radical is expelled. The rate constant for oxidation of methyl linoleate in micelles, initiated by the lipid‐soluble initiator 2,2′‐azobis (2,4‐dimethylvaleronitrile), is significantly lower than the known rate constant of initiation in true solutions.