Synthesis, characterisation, cytotoxicity and radioprotective effect of novel chiral nitronyl nitroxyl radicals

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-1H-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-1H-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.