Antioxidant, DNA interaction, molecular docking and cytotoxicity studies of aminoethylpiperazine‐containing macrocyclic binuclear copper(II) complexes

Abstract

A series of new macrocyclic binuclear copper(II) complexes of the type [Cu2L1–5(ClO4)](ClO4) (1–5) were synthesized by template condensation between precursor compounds 2,6‐bis(4‐aminoethylpiperazin‐1‐ylmethyl)‐4‐substituted phenols and 2,6‐diformyl‐4‐substituted phenols. The synthesized precursors and complexes were characterized using regular physicochemical techniques. The rate constant values obtained for the hydrolysis of 4‐nitrophenylphosphate were in the range 1.83 × 10−2–4.19 × 10−2 min−1. Antioxidant studies against 2,2′‐diphenyl‐1‐picrylhydrazyl revealed the antioxidant potency of the synthesized complexes. Binding studies of the complexes with calf thymus DNA were conducted using electronic, viscometric and voltammetric techniques, and the obtained results suggested a non‐covalent groove mode of binding. The oxidative cleavage of pBR322 DNA in the presence of co‐reactant H2O2 and radical scavengers showed single strand scission and involvement of H2O2 radical in the cleavage process. Molecular docking studies were performed to insert complexes into the crystal structures of 1BNA and VEGFR kinase at active sites to determine the possible binding mode and predominant binding interactions. In vitro cytotoxicity of the complexes was tested against human epidermoid carcinoma cells (A431) by MTT assay, which revealed the effective anticancer activity of the complexes. Live cell and fluorescent imaging of A431 cells showed that the complexes induce cell death through apoptosis.

In vitro anti‐proliferative and in silico docking studies of heteroleptic copper(II) complexes of pyridazine‐based ligands and ciprofloxacin

“…Further, the spectra of the complexes showed peaks at ca 1100 cm −1 (antisymmetric stretching) and ca 625 cm −1 (antisymmetric bending) of perchlorate ions. The splitting of the band at 1100 cm −1 and an additional band at around 930 cm −1 clearly indicates the presence of the coordinated perchlorate ion in the complexes . Moreover, the appearance of weak bands in the regions 553–577 and 451–477 cm −1 attributed to the ʋ (M─O) and ʋ (M─N) stretching vibrations, respectively, further confirms the complexation .…”

“…The splitting of the band at 1100 cm −1 and an additional band at around 930 cm −1 clearly indicates the presence of the coordinated perchlorate ion in the complexes. [28] Moreover, the appearance of weak bands in the regions 553-577 and 451-477 cm −1 attributed to the ʋ(M─O) and ʋ(M─N) stretching vibrations, respectively, further confirms the complexation. [29] All these features are consistent with the proposed structures of the complexes, in which the copper(II) ion is coordinated through azomethine nitrogen, phenolic oxygen and pyridazine nitrogens of monoanionic tridentate ligand, oxygen atoms of the ciprofloxacin drug and oxygen atom of perchlorate anion.…”

Unusual Ni⋯Ni interaction in Ni(ii) complexes as potential inhibitors for the development of new anti-SARS-CoV-2 Omicron drugs

“…Molecular docking is an attractive technique for elucidating the interaction mode and binding affinity between a drug and various biological molecules at the supramolecular level. 70–72 In our experiment, molecular docking studies of the nickel( ii ) coordination complexes [Ni(L)] 2 ( 1 ) and [Ni(L)] n ( 2 ) with the crystal structure of OSPHR2 in complex with DNA (PDB ID: ) were performed in order to preliminarily predict the chosen binding sites. Fig.…”

Potential of Copper and Copper Compounds for Anticancer Applications

“…Inspired by traditional metal–organic coordination chemistry, the researchers propose a new concept of constructing Cu nanostructures using metal coordination-driven self-assembly. Karthick et al synthesized a series of new [Cu 2 L1-5 (ClO 4 )] (ClO 4 -1-5) ( Figure 6 A)-type macrocyclic binuclear copper (II) complexes through the template condensation reaction between the precursor compound 2,6-bis (4-aminoethylpiperazin-1-ylmethyl)-4-substituted phenol and 2,6-diformyl-4-substituted phenol [ 65 ]. The in vitro cytotoxicity of the complex against human epidermoid cancer cells (A431) was tested by MTT assay, and the results showed that the complex has effective anticancer activity.…”