Synthesis, structures, molecular docking, cytotoxicity and bioimaging studies of two novel Zn(II) complexes

Two novel compounds [Zn2(Endc)2(bipy)2(H2O)3]·4(H2O)·2(O)(1), [Zn2(Endc)2(phen)2(H2O)]·(O)(2) (bipy = 2,2-bipyridine, phen = 1,10-phenanthroline, and Endc = endo-norbornene-cis-5,6-dicarboxylicacid) have been synthesized and characterized. In this paper abbreviations are FS-DNA (fish sperm DNA), HeLa (human cervix epithelia carcinoma cells), KB (human oral epithelial carcinoma cells), LO2 (human liver cell L-O2), EtBr (ethidium bromide), DMF (Dimethyl Formamide), MTT ([3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium]). The binding of complexes with Fish Sperm DNA were measured by electronic absorption spectra and fluorescence spectroscopy. The ability of these complexes to cleave the pBR322 plasmid DNA or the KB and HeLa DNA extracted in our laboratory was demonstrated by gel electrophoresis assay. The cytotoxic effects of these complexes were examined on two tumor cell lines, HeLa, KBr and one normal cell line LO-2. UV absorption and fluorescence spectra indicate the ability of the complexes bond to DNA with different binding affinity. Gel electrophoresis assay demonstrates which one complex more effective DNA-cleavage activity. The cytotoxic activity of the complexes was tested against two different cancer and one normal cell lines. The two complexes exhibited cytotoxic specificity and significant cancer cell inhibitory rate and lower cytotoxicity toward the normal cell lines. The unique interaction mode with DNA and cancer cells inhibition effect clearly revealed the relationship between the structure and the activity of the novel antitumor agent Zn(II) complexes.