EPR study of beta-phosphorylated stable aminoxyl radicals in the presence of liposomes

The behaviour of four stable beta -phosphorylated aminoxyl, radicals of the pyrrolidinoxyl series has been studied by EPR spectroscopy in the presence of dimyristoyl-phosphatidylcholine (DMPC) unilamellar liposomes. The affin ity of these compounds for the liposome structure was found to be more,or l ess high depending on their hydrophobicity In each case, computer simulatio ns of experimental EPR spectra permitted the determination of the hyperfine coupling constants of the radical inserted in the phospholipid bilayer.