Dimerization of Mn(III) complexes driven by the solvent. Correlation with the catalase like activity

C. M. PALOPOLI; A. CAIMI; F. FARABOLLINI; A. RECIO BALSELLS; S. SIGNORELLA

Smolenice

Conferencia; XXIV. International Conference on Coordination and Bioinorganic Chemistry; 2013

Slovak Academy of Sciences

Manganese catalases (MnCAT) and superoxide dismutases (MnSOD) deplete O2?? and O22? in cells through a ping-pong mechanism involving cyclic redox processes of the metal cofactor. To dismutate efficiently O2?? and O22?, the ºE of MnSOD and MnCAT is fine-tuned to values much lower than that of the Mn3+(ac)/Mn2+(ac) couple. In this work we evaluated the catalytic activity of mononuclear Mn complexes with the ligands: 1,3-bis(3,5-diX-salicylidenamino)propane (X=Cl or F), 1,3-bis(5-NO2salicylidenamino)propane in different solvents (MeOH, MeCN, DMF, DMSO). The catalase activity was tested using a volumetric method and measuring the oxygen evolution of H2O2 + catalyst mixtures with a Clark-type oxygen electrode. The SOD activity was assayed by measuring the inhibition of the photoreduction of NBT in the presence of the catalyst.