IQUIR   05412
INSTITUTO DE QUIMICA ROSARIO
Unidad Ejecutora - UE
artículos
Título:
NEW BIOMIMETIC ANTIOXIDANTS WITH CATALASE AND SUPEROXIDE DISMUTASE ACTIVITY
Autor/es:
DAIER, VERÓNICA; CLAUDIA PALOPOLI,; HERNÁN BIAVA,; DIEGO MORENO,; SANDRA SIGNORELLA,
Revista:
Biocell
Referencias:
Año: 2007 vol. 31 p. 145 - 145
ISSN:
0327-9545
Resumen:
In a variety of pathological situations the production of reactive oxygen species overwhelms the activity of endogenous defence systems (catalases (CAT) and superoxide dismutases (SOD)). Renewed interest has recently been stimulated by reports of catalytic antioxidants as novel therapeutics based on their ability to sequester oxidants at a much higher rate than stoichiometric antioxidants. Particularly attractive are complexes exhibiting combined CAT and SOD activity because they offer a possible therapeutic advantage arising from their multiple mechanism of action. With this in mind, we have evaluated the SOD and CAT activity of new Mn complexes of 1,3-bis(2-hydroxybenzyl-2-methylpyridylamino)propan-2-ol (H3L1), 1,4-bis(salicylidenamino) butan-2-ol (H3L2), 1,5-bis(5-sulphonatesalicilidenamino)pentan-3-ol (H3L3) and 1,5-bis(2-hydroxybenzyl-2-methylpyridylamino)pentan-3-ol (H3L3). These ligands afford Mn complexes of different nuclearity, that are good structural mimics of MnSOD and MnCAT. The catalase activity was determined polarographically by measuring the oxygen concentration of H2O2 + catalyst mixtures with a Clark-type oxygen electrode. The SOD activity was assayed by measuring the inhibition of the photoreduction of nitro blue tetrazolium in the presence of the catalyst. Complexes Mn2L1 and Mn2L4, with Mn ions possessing saturated coordination spheres, showed moderate CAT activity. Complex Mn2L3 was found to be highly efficient to disproportionate H2O2 in aqueous basic medium and is the most efficient MnCAT mimic known up to date. Complex MnL2 was found to be an excellent catalyst with combined SOD/CAT activity.