INVESTIGADORES
DAIER Veronica Andrea
artículos
Título:
Synthesis, characterization and combined superoxide dismutase and catalase activities of manganese complexes of 1,4-bis(salicylidenamino)butan-2-ol
Autor/es:
DAIER VERÓNICA; MORENO DIEGO; DUHAYON CARINE; TUCHAGUES JEAN PIERRE; SIGNORELLA SANDRA
Revista:
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
Editorial:
WILEY-V C H VERLAG GMBH
Referencias:
Año: 2010 p. 965 - 974
ISSN:
1434-1948
Resumen:
Two MnIV complexes of general formula [Mn(salbutO)X]
[H3salbutO = 1,4-bis(salicylidenamino)butan-2-ol, 1: X = N3,
2: X = SCN] have been prepared and structurally charac-
terized. The crystal structure of 1 shows that salbutO3 acts
as a pentadentate ligand through the two phenolato-O, two
imino-N, and one alcoholato-O atoms, and the sixth coordi-
nation position is occupied by the azido-N atom, resulting in
a slightly distorted N3O3 donor set around the MnIV ion. ESI-
MS, UV/Vis, and 1H NMR spectroscopy were used for solu-
tion studies. In methanol and dmf, the starting complexes are
converted into [MnIII(salbutO)] and its dimeric form. The
E1/2 of MnIII/MnIV (ca. 0.4 V vs. Ag/AgCl) allows this couple
to efficiently catalyze the dismutation of O2· with catalytic
rate constant and IC50 values of 1.91 ϫ 106 M1 s1 and
1.43 μM, respectively, which were obtained through the nitro
blue tetrazolium photoreduction inhibition SOD assay, in
aqueous solution of pH 7.8. The Mn-salbutO complexes also
show catalase activity in methanol and dmf, with kcat = 1.6
M2 s1 and 5.6 M1 s1, respectively, an advantageous prop-
erty for acting as scavenger of reactive oxygen species (ROS).
This valuable conjunction of properties results from the con-
version of [MnIV(salbutO)X] into [MnIII(salbutO)]2 in equilib-
rium with its monomer [MnIII(salbutO)].