Mechanisms of lipid peroxidation: Iron catalyzed decomposition of fatty acid hydroperoxides as the basis of hydrocarbon evolution in vivo

Summary Ethane and pentane are evolved during peroxidation of tissue lipids in vivo and are believed to be derived from 3 and 6 fatty acids respectively. We present evidence supporting a scission mechanism as the means of forming these hydrocarbons during hydroperoxide decomposition. A fatty acid 6 hydroperoxide (methyl 13-hydroperoxy-6,9,11-octatrienoate), when incubated with a ferrous ion, yielded pentane as the major hydrocarbon (98%). Reaction with ferrous ion results in an alkoxy radical capable of undergoing scission to an aldehydic fatty acid and a hydrocarbon.We wish to thank Dr Ned Porter for both his generous donation of a supply of hydroperoxide and for his suggestions regarding possible reaction mechanisms. This research was supported by U.S.P.H.S. N.I.H. Grants ES00798, HL16264 and T32 GM07105.