Evaluation of Antimicrobial, Antitumor, Antioxidant Activities, and Molecular Docking Studies of Some Co(II), Cu(II), Mn(II), Ni(II), Pd(II), and Pt(II) Complexes With a Schiff Base Derived From 2‐Chloro‐5‐(trifluoromethyl)aniline

The antimicrobial, antitumor and antioxidant potential of Co(II), Cu(II), Mn(II), Ni(II), Pd(II), and Pt(II) complexes with 2‐(((2‐chloro‐5‐(trifluoromethyl)phenyl)imino)methyl)phenol HL ligand was investigated. A molecular docking study was carried out to estimate the predicted binding affinity of the compounds to protein targets involved in proliferative and bacterial activities. Fluorescence quenching studies and synchronous spectra were used to examine the metal complexes interactions with CT‐DNA and BSA protein. The DNA binding study have revealed that the complexes are capable of binding with DNA via intercalative mode. The antimicrobial activity of the ligand and metal complexes was studied against three Gram‐positive bacteria, two Gram‐negative bacteria, and three strains of fungi. The best antibacterial effect was demonstrated by the Pt(II) complex on the Staphylococcus aureus strain, and as for the inhibitory effect on fungi, it was stronger on the Candida albicans strain after treatment with the Co(II) complex. The in vitro antiproliferative activity of ligand and complexes was analyzed using MTT, Annexin V/PI, and cell cycle assays. The in vitro results showed that, except for Pd(II) complex, where slight effects were observed, the MCF‐7 line was resistant to the activity of the complexes. In the case of A549 cells, Cu(II) and Pd(II) complexes showed a dose‐dependent antitumor activity, confirmed by both the Alamar blue and the Annexin V/PI analysis. Finally, the antioxidant activity of the compounds was examined by ABTS and DPPH methods. Antioxidant investigation showed that the Ni(II) complex possesses a remarkable ability to trap the cation of the ABTS + radical (IC 50 value 9.35 μM).