Bioinspired Aldimine‐Based Copper Complexes as Artificial Nucleases

Abstract In this study, we have synthesized and structurally characterized mononuclear copper(II) complexes from salicylaldehyde‐based aldimine ligands H 2 L1 and H 2 L2. The structures and geometries of the ligands and the complexes are optimized using quantum mechanical calculations through DFT studies. Additionally, the interactions of the ligands and the complexes with DNA and BSA are investigated experimentally through spectrophotometric techniques and theoretically using molecular docking studies. The binding constant value for CuL2 is higher, 8.33 × 10 5 M −1 , than CuL1 based on UV absorption titration. The fluorescence quenching constant values for both the complexes with the DNA are found to be 8.9 × 10 3 M −1 . The fluorescence quenching constant based on the BSA quenching assay is found to be higher for CuL1, 1.596 × 10 4 M −1 . Further, the ability of the test compounds to cleave plasmid DNA (pBR322) is monitored through gel electrophoresis technique. The cell‐death assay against human hepatocellular carcinoma, HepG2 cell lines, reveals a higher cytotoxic effect of CuL1 with the IC 50 value of 41.09 µg/mL than CuL2.