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Unusual kinetic isotope effects of deuterium reinforced polyunsaturated fatty acids in tocopherol-mediated free radical chain oxidations.

ABSTRACT: Substitution of -CD2- at the reactive centers of linoleic and linolenic acids reduces the rate of abstraction of D by a tocopheryl radical by as much as 36-fold, compared to the abstraction of H from a corresponding -CH2- center. This H atom transfer reaction is the rate-determining step in the tocopherol-mediated peroxidation of lipids in human low-density lipoproteins, a process that has been linked to coronary artery disease. The unanticipated large kinetic isotope effects reported here for the tocopherol-mediated oxidation of linoleic and linolenic acids and esters suggests that tunneling makes this process favorable.

SUBMITTER: Lamberson CR

PROVIDER: S-EPMC4578730 | biostudies-literature | 2014 Jan

REPOSITORIES: biostudies-literature

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Unusual kinetic isotope effects of deuterium reinforced polyunsaturated fatty acids in tocopherol-mediated free radical chain oxidations.

Lamberson Connor R CR Xu Libin L Muchalski Hubert H Montenegro-Burke J Rafael JR Shmanai Vadim V VV Bekish Andrei V AV McLean John A JA Clarke Catherine F CF Shchepinov Mikhail S MS Porter Ned A NA

Journal of the American Chemical Society 20140108 3

Substitution of -CD2- at the reactive centers of linoleic and linolenic acids reduces the rate of abstraction of D by a tocopheryl radical by as much as 36-fold, compared to the abstraction of H from a corresponding -CH2- center. This H atom transfer reaction is the rate-determining step in the tocopherol-mediated peroxidation of lipids in human low-density lipoproteins, a process that has been linked to coronary artery disease. The unanticipated large kinetic isotope effects reported here for t ...[more]

PMID: 24380377

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