Evidence for the one-electron oxidation of 1-methyl-4-phenyl-2,3-dihydropyridinium (MPDP+)

Optical data have shown that the neurotoxin metabolite 1-methyl-4-phenyl-2,3-dihydropyridinium undergoes one-electron oxidation/reduction in the presence of iron chelates. The activation energy for one-electron oxidation of 1-methyl-4-phenyl-2,3-dihydropyridinium is less than that for two-electron oxidation. Horseradish peroxidase catalyzes the oxidation of 1-methyl-4-phenyl-2,3-dihydropyridinium. Reactivity of 1-methyl-4-phenylpyridinyl radical is discussed in relation to the well-known pyridinyl radicals.