Synthesis and structure elucidation of novel salophen-based dioxo-uranium(VI) complexes: In-vitro and in-silico...

The synthesis and characterization of three dioxo U(VI) complexes, [UO₂(L¹)(OH₂)], [UO₂(L²)DMF], and [UO₂(L²)DMSO], [L¹]^2- = 1,1'-(4-methyl-1,2-phenylenebis (nitrilomethylidyne))di-2-naphtholate: [L²]^2- = 1,1'-(o-phenylenebis (nitrilomethylidyne)) di-2-naphtholate, are reported. Elemental analysis, FT-IR, ¹HNMR, UV-Vis spectroscopy, molar conductivity and single crystal X-ray diffraction were used to characterize the complexes. It was found that the complexes adopt a distorted pentagonal bipyramidal coordination geometry. The interaction of the synthesized complexes with DNA and bovine serum albumin was thoroughly investigated using both experimental and theoretical studies. UV-Vis absorption and fluorescence quenching techniques were applied to determine the binding parameters as well as the mechanism of the interaction of each complex with DNA and the protein. The results obtained suggested that interaction of the complexes with DNA occurred through partial intercalation into the minor grooves of DNA with binding constants in the range of 0.661 × 10⁵-1.56 × 10⁵ M^-1. In addition, interaction of the complexes with bovine serum albumin quenched the fluorescence emission of the tryptophan residues of the protein binding constants and thermodynamic parameters were obtained from the fluorescence quenching experiments at different temperatures. The values of binding constants revealed moderate interactions between the synthesized complexes and the protein suggesting that this protein could act as a suitable vehicle for transportation of the compounds. The results of molecular docking confirmed those of the experimental studies. The anticancer properties of the title complexes were also evaluated through a study of the in vitro cytotoxicity of the compounds against the HT-29 and MCF-7 cancer cell lines and the DPSC normal cell line using an MTT assay.