Antimicrobial, cytotoxic, and antioxidant activities and physicochemical characteristics of chromium(III) complexes with picolinate, dipicolinate, oxalate, 2,2′-bipyridine, and 4,4′-dimethoxy-2,2′-bipyridine as ligands in aqueous solutions

Abstract

The physicochemical properties of several chromium(III) complexes with ligands, such as picolinate, dipicolinate, oxalate, 2,2′-bipyridine, and 4,4′-dimethoxy-2,2′-bipyridine were investigated. First, the stability and formation constants of the synthesised chromium(III) complexes in aqueous solutions were evaluated with potentiometric titrations. In addition, the stoichiometry of each chromium(III) complex in water was analysed with conductometric titrations. Next, the potential antioxidant properties of chromium(III) compounds were determined by evaluating the ability of the synthesised complexes to reduce nitro blue tetrazolium salt. We also investigated the antimicrobial properties of the solutions of these compounds against Bacillus subtilis, Escherichia coli, Enterococcus faecalis, Pseudomonas aeruginosa, Staphylococcus aureus, and Staphylococcus epidermidis. The cytotoxic properties of chromium(III) complexes were tested using a human keratinocyte cell line (HaCaT).