Wilson's Disease Research Today is a free monthly online journal that collates and summarizes the latest research about Wilson's Disease, including details on treatment, causes, symptoms, medication. | ||||||||
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Raman, IR, UV-vis and EPR characterization of two copper dioxolene complexes derived from L-dopa and dopamine.Barreto WJ, Barreto SR, Ando RA, Santos PS, Dimauro E, Jorge T Laboratory of Environmental Physical Chemistry, Department of Chemistry, CCE, Londrina State University, Londrina, PR 86051-990, Brazil. The anionic complexes [Cu(L(1-))(3)](1-), L(-)=dopasemiquinone or L-dopasemiquinone, were prepared and characterized. The complexes are stable in aqueous solution showing intense absorption bands at ca. 605nm for Cu(II)-L-dopasemiquinone and at ca. 595nm for Cu(II)-dopasemiquinone in the UV-vis spectra, that can be assigned to intraligand transitions. Noradrenaline and adrenaline, under the same reaction conditions, did not yield Cu-complexes, despite the bands in the UV region showing that noradrenaline and adrenaline were oxidized during the process. The complexes display a resonance Raman effect, and the most enhanced bands involve ring modes and particularly the nuCC+nuCO stretching mode at ca. 1384cm(-1). The free radical nature of the ligands and the oxidation state of the Cu(II) were confirmed by the EPR spectra that display absorptions assigned to organic radicals with g=2.0005 and g=2.0923, and for Cu(II) with g=2.008 and g=2.0897 for L-dopasemiquinone and dopasemiquinone, respectively. The possibility that dopamine and L-dopa can form stable and aqueous-soluble copper complexes at neutral pH, whereas noradrenaline and adrenaline cannot, may be important in understanding how Cu(II)-dopamine crosses the cellular membrane as proposed in the literature to explain the role of copper in Wilson disease. Published 6 June 2008 in Spectrochim Acta A Mol Biomol Spectrosc.
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