Molecular mechanism of hydrogen peroxide conversion and activation by Cu(II)-amikacin complexes.
The interactions between Cu(II)-amikacin complexes [Cu(II)-Ami] and hydrogen peroxide were studied by spectroscopy (EPR, UV-vis, CD, XAS) and cyclic voltammetry. A monomer-dimer equilibrium was detected at complex concentrations above 5 mM (log K(dim) = 1.84 +/- 0.03). The dimeric complex undergoes easy, although irreversible oxidation (ca. 0.5-0.6 V) to a Cu(III) species on platinum electrode. However, the monomeric complexes are able to catalyze hydrogen peroxide disproportionation reaction at pH 7.4 in a multistep process, mediated by hydroxyl radicals and involving both Cu(I)/Cu(II) and Cu(II)/Cu(III) redox pairs.
Jezowska-Bojczuk
M
M
Faculty of Chemistry, University of Wroclaw, F. Joliot-Curie 14, 50-383 Wroclaw, Poland. MJB@wchuwr.chem.uni.wroc.pl
Leśniak
W
W
Bal
W
W
Kozłowski
H
H
Gatner
K
K
Jezierski
A
A
Sobczak
J
J
Mangani
S
S
Meyer-Klaucke
W
W
D000583:Amikacin / Q000737:chemistry*; D000900:Anti-Bacterial Agents / Q000737:chemistry*; D002384:Catalysis; D003300:Copper / Q000737:chemistry*; D004566:Electrodes; D006861:Hydrogen Peroxide / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D016877:Oxidants / Q000737:chemistry*; D010084:Oxidation-Reduction; D010984:Platinum; D013057:Spectrum Analysis
D000900:Anti-Bacterial Agents; D016877:Oxidants; D010984:Platinum; D003300:Copper; D000583:Amikacin; D006861:Hydrogen Peroxide