Synthesis, crystallographic studies, electrochemical and in vitro cytotoxicity properties of two Mn (II) and U(IV) complexes containing dipicolinic acid and 4-dimethylaminopyridine

Two new coordination complexes, [pydcH(2)][Mn-2(pydc)(2)(H2O)(6)] (1) and [dmapH(2)][UO2(pydc)(2)] (2) were obtained from a compound containing dipicolinic acid and 4-dimethylaminopyridine.The complexes were characterized by X-ray crystallography. Electrochemical behavior of the compounds was investigated by cyclic voltammograms. Redox couples were observed at E-0' 1.625 and -0.159 V for (1) and (2) respectively, versus Ag/AgCl, under argon. After aeration, stronger interaction tendency with oxygen was exhibited for complex (1) compared to (2), within 5 min. In the next section, toxicity of each of three compounds were assayed using oxaliplatin as a standard, under MTT method, against MCF7 (a human breast cancer), HeLa (a human cervix epithelioid carcinoma) and KB (a human oral epithelial carcinoma) cell lines. Complex (1) with E-0' of about ten times (2) proved further cytotoxic potential on all three tested cancerous cell line compared to (2). The highest inhibition potential was exhibited on MCF7 cell line (IC50 = 1.00 mu M, Viability inhibition = 81.19%) for (1). Determination of mitochondrial membrane potential (MMP) and reactive oxygen species (ROS) in treated MCF7 cells with (1) confirmed a clear decrease in MMP and sharp increases in ROS generation in this cell line. (C) 2020 Elsevier Ltd. All rights reserved.