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

Abstract

Two new coordination complexes, [pydcH2][Mn2(pydc)2(H2O)6] (1) and [dmapH2][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 E0ˊ 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 E0ˊ 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 μM, 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.