Cytotoxicity of the novel spin trapping compound 5-ethoxycarbonyl-3,5-dimethyl-pyrroline N-oxide (3,5-EDPO) and its derivatives

ESR spin trapping allows detection of superoxide radicals. Novel spin traps forming more stable superoxide adducts (t1/2 ca. 12–55 min) were tested for their toxicity to cultured cells. The following toxicity ranking was obtained: 4,5-DPPO > 4-BEMPO 3-BEMPO > trans-3,5-EDPO > 3,5-DPPO 4,5-DiPPO 4,5-EDPO > cis-3,5-EDPO 3,5-DiPPO > DEPMPO. In conclusion, 4,5-EDPO, cis-3,5-EDPO and 3,5-DiPPO can be recommended for further investigation of superoxide in biological systems.