Nitroxyl compounds have been previously investigated as potential radioprotection drugs. To develop new radioprotectors, two kinds of novel chiral nitronyl nitroxyl radicals: L- tert-butyl 2-(4, 5-dihydro-4, 4, 5, 5-tetramethyl-3-oxido-1 H-imidazol-3-ium-1-oxyl-2-yl) pyrrolidine-1-carboxylate ( L-NNP) and L- tert-butyl 2-[(4-(4, 5-dihydro-4,4,5,5-tetramethyl-3-oxido-1 H-imidazol-3-ium-1-oxyl-2-yl)-2-methoxyphenoxy)methyl] pyrrolidine-1-carboxylate ( L-NNVP) have been synthesised. The cytotoxic and radioprotective effects of these two compounds were then evaluated in rat glioma C6 cells.