Pyridine‐derived Schiff base copper (II), zinc (II), and cadmium (II) complexes: Synthesis, structural properties, biological evaluation, and docking studies

Abstract

Herein, Cu (II), Zn (II), and Cd (II) complexes, [DEP(M)X2], encompassing the pyridine‐derived Schiff‐base ligand DEP, where DEP is (E)‐N,N‐diethyl‐2‐([pyridine‐2‐ylmethylene]amino)ethane‐1‐amine, are synthesized. X‐ray diffraction studies reveal distorted square pyramidal geometries for the Cd (II) and Cu (II) complexes, whereas the geometry of [DEP (Zn)Cl2] can best be described as trigonal bipyramidal. The antibacterial potential of DEP and its [DEP(M)X2] complexes were evaluated against four bacterial strains: Salmonella typhi, Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa; five fungal strains: Candida glabrata, Candida albicans, Microsporum canis, Fusarium solani, and Aspergillus flavus; and Leishmania major protozoan. Complexes exhibited superior bactericidal, fungicidal, and leishmanicidal inhibition potential against all tested microbes compared with the free ligand. The preliminary cytotoxic activity of [DEP(M)X2] complexes on breast and colon carcinoma cells, that is, MCF‐7cell line and HCT‐116 cell line, respectively, revealed that studied complexes showed high cytotoxicity compared with ligand (DEP). Among the studied complexes, [DEP (Cd)Br2] exhibited an excellent inhibitory profile, as confirmed by the docking study. The molecular docking studies showed a good correlation between the biological activities of synthesized metal complexes and docking studies. We have confidence in the contribution of these complexes toward the design of new metal‐derived candidates that can treat infectious diseases.

Insight into the inhibitory potential of metal complexes supported by (E)-2-morpholino-N-(thiophen-2-ylmethylene)ethanamine: synthesis, structural properties, biological evaluation and docking studies

“…48 Bands corresponding to the n → π* electronic transition owing to the imine CN group were observed at approximately 275–355 nm. 14,35 A bathochromic shift was observed in the absorption wavelength of complexes, indicating that a lone pair of electrons of N is donated to M( ii ) ions upon complexation (Fig. 1).…”

“…1). 35,48 In addition, representative time–stability curves of [TEM(Cd)Br 2 ] at 0 and 72 h are shown in Fig. S13 †.…”

“…The Molecular Operation Environment (MOE) 2015 software was used for studying molecular docking. 34,35 The charge correction, missing addition of hydrogen, and removal of water molecules from the selected residue were performed before molecular docking. In addition, corrected protonation was achieved using a 3D protonate module in the MOE with a generalized Born/volume integral electrostatic function.…”