Unusual Kinetic Isotope Effects of Deuterium Reinforced Polyunsaturated Fatty Acids in Tocopherol-Mediated Free Radical Chain Oxidations

详细信息    查看全文

• 作者：Connor R. Lamberson ; Libin Xu ; Hubert Muchalski ; J. Rafael Montenegro-Burke ; Vadim V. Shmanai ; Andrei V. Bekish ; John A. McLean ; Catherine F. Clarke ; Mikhail S. Shchepinov ; Ned A. Porter
• 刊名：Journal of the American Chemical Society
• 出版年：2014
• 出版时间：January 22, 2014
• 年：2014
• 卷：136
• 期：3
• 页码：838-841
• 全文大小：226K
• ISSN：1520-5126

文摘

Substitution of 鈭扖D₂鈥?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 鈭扖H₂鈥?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.