Platinum complex with pyrimidine- and morpholine-based ligand: synthesis, spectroscopic, DFT, TDDFT, catalytic reduction, in vitro anticancer, antioxidant, antimicrobial, DNA binding and molecular modeling studies

Abstract

New monometallic platinum complex ([PtL2Cl2]Cl2) of pyrimidine and morpholine derivative ligand were synthesized and structurally elucidated by elemental analysis, molar conductance, 1H NMR, FT-IR, ESI-MS and UV-Visible spectroscopic techniques. Analytical and spectroscopic result suggests that platinum complex has octahedral geometry. In order to understand the molecular geometry and absorption spectra of the ligand and platinum complex, DFT and TDDFT calculations have been carried out. Catalytic reduction of platinum complex with p-nitrophenol (p-NP) was carried out by the spectrophotometric method. In vitro anticancer activity of ligand and platinum complex on human cancer cell lines (MCF-7, HepG2, HeLa and A549) as well as normal cell (NHDF) line was done by MTT assay. This result reveals that platinum complex has enhanced anticancer against MCF-7 (19.13 ± 0.96 µg/mL) cell line than HepG2 (32.82 ± 1.64 µg/mL), HeLa (29.2 ± 1.46 µg/mL) and A549 (34.21 ± 1.71, µg/mL) cell lines as compared to ligand. Antioxidant activity results sustained that platinum complex has better radical scavenging ability than ligand. Platinum complex has better antimicrobial activity toward E. coli bacteria and C. albicans fungi than other antimicrobial pathogens. DNA binding affinities of the ligand and platinum complex have been assessed by probing their ability to bind to calf thymus DNA (CT-DNA) with UV-Visible, fluorescence, viscometric measurements and cyclic voltammetric techniques. These results proved that ligand and platinum bind to CT-DNA by intercalative binding mode. Molecular docking analysis reveals that the platinum complex tends to show good binding affinity toward both DNA and BSA than ligand.