Synthesis and Characterization of Heteroleptic Copper and Zinc Complexes with Saccharinate and Aminoacids. Evaluation of SOD-like Activity of the Copper Complexes

Five new copper and zinc heteroleptic complexes with saccharin and aminoacids with general stoichiometry Na2[M(sac)2(aa)2]⋅nH2O (M denotes Cu or Zn, sac the saccharinate ion, and aa the aminoacids) were synthesized and characterized by elemental and thermogravimetric analysis, conductimetric measurements and IR, Raman and UV–vis spectroscopies. In all the complexes, copper and zinc ions coordinated with the aminoacids through the terminal amine and carboxylate residues and with saccharin through the heterocyclic nitrogen atom. Besides, the superoxide dismutase-like activity of the heteroleptic copper complexes was evaluated and compared with the homoleptic copper amino acid complexes with the aim to observe the influence of the saccharin coordination.