Characterization and superoxide dismutase activity of copper(II) complexes of 6A,6X-difunctionalized β-cyclodextrins

Abstract

Thermodynamic and EPR spectroscopic measurements were carried out in aqueous solution on copper(II) complexes of β-cyclodextrins 6A,6X-difunctionalized (X = B, C or D) with histamine (imidazole-4-ethanamine). The O₂^– scavenger activity of these systems was determined through both enzymatic and photohaemolysis assays. An attempt was made to correlate the scavenger ability with the geometrical features of the copper(II) complexes. The determination of the stability constants of the copper(II) complexes with 6A,6B-bis[2-(imidazol-4-yl)ethylamino]-6A,6B-dideoxy-β-cyclodextrin revealed the speciation under the experimental conditions.