Scrutinizing the DNA damaging and antimicrobial abilities of triazole appended metal complexes
•Synthesis of new and efficient DNA targeting triazole derived complexes•Synthesis of good metallointercalators•Exceptional DNA exploiting ability of nitro substituted Cu(II) complex•Better antimicrobial effect of complexes against various pathogens
New mononuclear transition metal complexes 1–12 bearing the bioactive triazole analogues were synthesized and characterized by elemental analysis and spectroscopic techniques. The interaction of calf thymus DNA (CT-DNA) with the synthesized compounds was studied at physiological pH by spectrophotometric, spectrofluorometric, cyclic voltammetry, and viscometric techniques. The entire DNA binding results suggested the intercalative mode of binding for the synthesized compounds. Interestingly, the binding strength of the complexes is found to be greater than that of the free ligands. Among the complexes explored, complex 5 reveals strong hypochromism and a slight red shift as compared to the other complexes highlighting its higher DNA binding propensity. The intrinsic binding constant values of the complexes compared to cisplatin reveal that all the complexes are greater in magnitude than that of cisplatin. Fluorescence titrations show that the Cu(II) complexes have the ability to displace DNA-bound ethidium bromide. Also, these compounds induce cleavage in pBR322 plasmid DNA as indicated in gel electrophoresis and exhibit excellent nuclease activity in the presence of H2O2. Moreover, the complexes were screened for in vitro antimicrobial activity along with free ligands and solvent control. The outcome is that the complexes possess good activity than the free ligands. These complexes may have further scope in developing them into antimicrobial drugs and DNA probes.
Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slide
Journal: Journal of Photochemistry and Photobiology B: Biology - Volume 158, May 2016, Pages 136–144