Novel copper nano-complex based on tetraazamacrocyclic backbone: Template synthesis, structural elucidation, cytotoxic, DNA binding and molecular docking studies

Bioactive binuclear Cu(II) nanocomplex of 1,8-dihydro-6-13-di(2-hydroxybenzoyl)-dibenzo[b,i]-1,4,8,11tetra-azacycloretradeca-4,6,11,13-tetraene) (H4L) derived from 3-formylchromone and o-phenylenediamine in molar ratio 2:2:2 has been designed via template methodology. The structure of macrocyclic ligand (H4L) has been determined by elemental analysis and FT-IR and 1HNMR spectroscopy. As well, the new complex witHgeneral formula: [Cu-2 (H2L)(NO3)(2)]; was characterized using elemental and thermal analyses, molar conductivity, magnetic susceptibility measurements, UV-Vis, FT-IR, EPR and mass spectroscopy. The crystallinity and morphology of the complex were analyzed by XRD and TEM measurements. On the basis of the spectroscopic data, the ligand behaves as a dianionic bis(tridentate) ligand througHOON donor sites forming tetrahedral complex. Transmission electron microscope (TEM) analysis reveals that Cu(II) nanocomplex has higHdispersed nanospherical morphology (2 nm). In order to gain some insight into the structure-activity relationship; the binding of H4L and its Cu(II) nanocomplex witHDNA was studied theoretically and by spectral titration. Absorption spectroscopic and docking investigation suggest that the H4L and Cu(II) complex bind to groove of DNA. The intrinsic binding constants (K b) of H4L and Cu(II) complex witHDNA are 0.69 x10 (4) and 0.90 x10 M-4(-1), respectively. The antioxidant activities of prepared compounds were studied. Also, the cytotoxicity assay indicates that Cu(II) nanocomplex exhibited significant inhibitory activity toward HepG-2 cell line, witHthe lowest IC50 value witHrespect to H-4 L and standard drugs. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

A bioactive binuclear Cu(II) nanocomplex has been designed and characterized for its antioxidant and significant cytotoxic activity towards HepG-2 cell line with a low IC50 value. The complex has been studied for its structure-activity relationship, interaction with DNA, and binding constants, showing promising potential as a therapeutic agent.