IQUIR   05412
INSTITUTO DE QUIMICA ROSARIO
Unidad Ejecutora - UE
artículos
Título:
Synthesis, characterization and antioxidant activity of water soluble MnIII complexes of sulphonato-substituted Schiff base ligands
Autor/es:
DIEGO MORENO; VERÓNICA DAIER; CLAUDIA PALOPOLI; JEAN-PIERRE TUCHAGUES; SANDRA SIGNORELLA
Revista:
JOURNAL OF INORGANIC BIOCHEMISTRY
Editorial:
ELSEVIER SCIENCE INC
Referencias:
Lugar: Amsterdam; Año: 2009
ISSN:
0162-0134
Resumen:
Two new MnIII complexes Na[Mn(5-SO3-salpnOH)(H2O)].5H2O (1) and Na[Mn(5-SO3-salpn)(MeOH)] . 4H2O (2) (5-SO3-salpnOH = 1,3-bis(5-sulphonatosalicylidenamino) propan-2-ol, 5-SO3-salpn = 1,3-bis(5-sulphonatosalicylidenamino)propane) have been prepared and characterized.Electrospray ionization-mass spectrometry, UV–visible and 1H NMR spectroscopicstudies showed that the two complexes exist in solution as monoanions [Mn(5-SO3-salpn(OH))(solvent)2]-, with the ligand bound to MnIII through the two phenolato-Oand two imino-N atoms located in the equatorial plane. The E1/2 of the MnIII/MnIIcouple (47.11 (1) and 77.80 mV (2) vs. Ag/AgCl) allows these complexes to efficientlycatalyze the dismutation of O2 .- , with catalytic rate constants 2.4 106 (1) and 3.6 106(2) M-1 s-1, and IC50 values of 1.14 (1) and 0.77 (2) 1M, obtained through the nitro bluetetrazolium photoreduction inhibition superoxide dismutase assay, in aqueous solutionof pH 7.8. The two complexes are also able to disproportionate up to 250 equivalents ofH2O2 in aqueous solution of pH 8.0, with initial turnover rates of 178 (1) and 25.2 (2)mM H2O2 min-1 mM-1 catalyst-1. Their dual superoxide dismutase/catalase activityrenders these compounds particularly attractive as catalytic antioxidants.