Redox-active Mn3+ complexes with antitumoral applications.

ROS consumption is the main purpose of various Mn-based enzymes, with SOD-2 and catalases as main examples[1,2]; other than contrast oxidation-stress related diseases, this action can interfere specifically with cancer cells proliferation especially through H2O2 dismutation[3][4]. Here we propose two Mn3+-based synzymes pairing in vitro cytotoxicity against lung cancer cells and powerful redox activity. As a start, we investigated their chemical features combining numerous analysis techniques from basic 1H-NMR, IR, ESI-MS and EA characterization to TGA, 2D-NMR, and UV-vis deconvolution studies. Once obtained convincing chemical profiles of these system we deeply studied their oxidation-reduction properties, particularly their redox potentials (via CV), their capacity to consume ROS of different size and type (DPPH, hydroxyl radical, hydrogen peroxide, superoxide UV-vis tests), and the specific kinetics of the H2O2 dismutation process using Clark electrode, which revealed that these two compounds share catalytic activity. Eventually, biological studies occurred: toxicologic experiments with the recently developed techniques employing Galleria mellonella larvae showed their innocuous nature towards higher eukaryotic organisms, whereas cytotoxicity assays demonstrated their efficacy against lung cancer cells. Future perspectives involve EPR analysis, XRD, computational studies, and deeper biological insights such as ROS consumption estimate in the various cell organelles and cytofluorimetric analysis.