Design and Characterization of Cu(II), Ni(II), and Co(II) Complexes with 5-Carboxy-2-Thiouracil: Spectroscopic, Antimicrobial and Cytotoxic Studies

In this paper, we describe and verify the structures and biological activity of novel metal complexes derived from 5-carboxy-2-thiouracil. We outline a synthesis method and assess the antimicrobial activity of newly formed Cu(II), Ni(II) and Co(II) complexes. Several syntheses were carried out with and without NaOH. The structures were verified using melting point analysis, MP-AES for Cu, Ni and Co and ICP-OES for sulfur, UV-Vis, ATR, solid-state and solution 1H NMR, 13C NMR spectroscopy. In addition, the antimicrobial activity of these complexes and the free ligand were assessed against both Gram-positive and Gram-negative bacteria, as well as yeasts. The HCT-116 colorectal cell line (ATCC) was used for a cytotoxic assay. Only two Ni(II) complexes showed reduction in the number of viable tumor cells. None of the other compounds led to a significant reduction in the number of viable cells, as determined by one-way ANOVA statistical analysis.