Effect of 2-methyl substitution on the stability of spin adducts composed of pyrroline N-oxide analogues and superoxide anion radicals

The synthesis of a novel alpha -phosphorus-containing spin trap, DEPDMPO (5 -diethoxy Phosphoryl-2, 5-dimethyl-1-pyrroline N-oxide) and the evaluation of its ability to spin-trap the hydroxyl and the superoxide anion radicals were described in the present article. The ability to trap an active supero xide anion radical generated in the photo system I (PSII) and the stability of their spin adduct of DEPDMPO as well as three previously reported traps DMPO, DEPMPO and M3PO were comparatively analyzed according to their chemi cal structures. In addition, the effects of 2-methyl and alpha -phosphoryl substituted analogues of DMPO on the stabilities of the corresponding spin adduts were systematically illustrated