Synthesis, characterization, biological applications, and molecular docking studies of some transition metal complexes with azo dye ligand derived from 5-methyl imidazole

Abstract

Metal complexes for Pd (II) and Pt (IV) ions were prepared and spectral identified using a new heterocyclic azo dye ligand 2-[2′-(3,4-dimethyl carboxy phenyl)azo]-5-methyl imidazole. In an alkaline ethanolic solution, a diazonium chloride salt solution of 2-amino-3,4-dimethyl benzoic acid and 5-methyl imidazole was reacted. Various spectral techniques, such as elemental analysis, (1HNMR , mass, FT-IR, UV–Vis.) spectroscopy, thermal analysis and FE-SEM-EDX, have been used to investigate azo dye ligand and chelate complex structures. Due to the presence of Cl outside the coordination sphere, the Pt(IV)-complex is the electrolyte because it contains conductive species, while the Pd(II) complex is not an electrolyte and does not contain conductive species. Based on the results, the ligand (N, N, O) behaves as a tridentate and coordinates with the metal ion via N-atom of the azomethine group (C = N) of the heterocyclic imidazole molecule, N-atom of the azo group (N = N) which are the furthest from imidazole ring, and O-atom of the benzoic acid ring. DPPH radical scavenging assays were also carried out on synthesized compounds to determine their antioxidant activities. A DPPH radical scavenging assay was used to measure the antioxidant activity of produced compounds and to compare them with ascorbic acid, a well-known antioxidant. Accordingly, the MTT cytotoxicity assay was used to assess the anti-cancer and toxicity of Pt(IV)-Complex against a breast cancer cell line (MCF-7). Molecular docking studies were performed on the new ligand and its metal complexes. It has been shown that the biological activity of compounds against breast cancer receptors was demonstrated by their interaction with BCL-2 and a BAX BH3 peptide from the RCSB protein data bank, PDB ID: 2XA0.