During our lifetime we are constantly being exposed to free radicals, which oxidize biologically important substances in the cells. We are partially protected against their harmful effects by a complex antioxidative system. In case a superoxide anion appears within the organism, the enzyme superoxide dismutase will always be the fastest to react with it and convert it to less reactive hydrogen peroxide and oxygen in the reaction of dismutation. Usage of SOD enzyme for therapeutic purposes has proven to be inappropriate, so the development has shifted towards smaller, synthetic SOD mimetics. In this thesis we were testing if the selected metal complexes (Cu, Mn, Ni, Pd) and nitroxides can be estimated as potential SOD mimetics. Their activity was evaluated using the indirect UV-Vis spectrophotometric method by Fridovich with the calculation of the I50 value. We measured a change in the absorbance at 550 nm in the absence (V0) and the presence (Vc) of various concentrations of potential SOD mimetics. We plotted the diagrams (V0 / Vc) – 1 in dependance to concentration of the analyte for all active compounds. We determined the concentration of the analyte needed to decrease the cytochrome c (I50) reduction rate by 50% at the value (V0 / Vc) = 1. We found out that the activity of metal complexes is mostly influenced by the type of included central ion, since only the already established reference compound with manganese center (Mn-salen) was shown as active, while other metal complexes (Cu, Ni, Pd) could not to convert superoxide . Due to predominantly negative results, some nitroxides were tested. All of them were active, but their efficacy requires a much higher concentration than in the reference compound, so they can be established as weak SOD mimetics.
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