Activity of Superoxide Dismutase Mimic of [Mn(salen)OAc] Complex Compound Non-enzymatically in Vitro Through Riboflavin Photoreduction

Abstract

The complex compound of [Mn(salen)OAc] can serve as mSOD and its activity has been determined non-enzymatically in vitro through riboflavin photoreduction. The complex was synthesized from Mn(OAc)2.4H2O and H2salen. Based on the elemental analysis, the C=56.69%; H=4.21%; and N=7.52% content are corresponding to the chemical formula of MnC18H17N2O4. The functional groups and ionic species in the complex have been analyzed by infrared spectroscopy and ESI-MS. SOD activity was determined by mixing complex at various concentrations with riboflavin and nitroblue tetrazolium (NBT), then the mixture was lighted with 20 Watt tungsten lamp for 15 minutes in a closed box. Then the reduced NBT absorptions were measured at λ 560 nm. The difference of absorbance between standard and sample solutions (without and with riboflavin, respectively) was multiplied by 100% to obtain %inhibition of each various sample concentration against NBT. SOD activity was obtained from IC50 data defined as a 50% inhibition of the plot curve of % inhibition to the concentration of the complex. The result obtained for this compound is IC50 = 2.7 ± 0.05 µM as well as enzymatic method. Therefore, this method can be used to determine the SOD activity by giving more stability and accuracy of IC50 value.