Six new zinc(II) complexes were prepared by the reaction of ZnBr2 or ZnI2 with 4'-(substituted-phenyl)-2,2':6',2''-terpyridine compounds, bearing p-methylsulfonyl (L1), p-methoxy (L2) and p-methyl (L3), which were characterized by elemental analysis, FT-IR, NMR and single crystal X-ray diffraction. The antiproliferative properties against Eca-109, A549 and Bel-7402 cell lines and the cytotoxicity test on RAW-264.7 of these compounds were monitored using a CCK-8 assay, and the studies indicate that the complexes show higher antiproliferative activities than cisplatin. The interactions of these complexes with CT-DNA and proteins (BSA) were studied by UV-Vis, circular dichroism (CD) and fluorescent spectroscopy, respectively. The results indicate that the interaction of these zinc(II) complexes with CT-DNA is achieved through intercalative binding, and their strong binding affinity to BSA is fulfilled through a static quenching mechanism. The simulation of the complexes with the CT-DNA fragment and BSA was studied by using molecular docking software. It further validates that the complexes interact with DNA through intercalative binding mode and that they have a strong interaction with BSA.
Keywords: CT-DNA binding; antiproliferative activity; fluorescence quenching; molecular docking; zinc (II) complexes.