Biomolecular Interaction, Molecular Docking, Antimicrobial, Antioxidant, Antitumor, Cell Cycle Analysis, and Annexin V/PI Assay Efficiency of Some Co (II), Cu (II), Mn (II), Ni (II), Pd (II), and Pt (II) Complexes With a Halogenated Bidentate Schiff Base

This study addresses the bioactivity evaluation of some complexes with a halogenated Schiff base ( HL ). The investigation of the biological potential was first performed in silico, through molecular docking studies. Thus, binding affinities of the ligand and complexes with various proteins involved in cancer and bacterial activity were analyzed. The results obtained indicated a decrease in the minimum binding energy by complexing the ligands to metal ions, thus a higher binding affinity. Interaction of the complexes with biomolecules has been investigated by electronic absorption and fluorescence spectroscopy. The results show that the complexes can bind to DNA via a minor groove binding mode. The study of antibacterial and antifungal activity in vitro carried out on three Gram‐positive bacteria, two Gram‐negative bacteria, and three strains of fungi revealed an antibacterial effect was manifested by the Pt (II) complex on the Staphylococcus aureus strain and an antifungal effect on the Candida albicans strain induced by Co (II) and Ni (II) complexes. HL ligand and its complexes were evaluated for cytotoxic activity against the MCF‐7 breast and A549 lung cancer cell lines, using MTT, Annexin V/PI, and cell cycle assays. The complexes showed cytotoxic potential on the tested tumor lines, notable results being attributed to the Cu (II) complex and especially the Pt (II) complex, in which case the observed toxic effect was very intense. The evaluation of the antioxidant potential of the compounds studied by DPPH and ABTS methods revealed for the Cu (II), Ni (II), and Mn (II) complexes a good antioxidant activity against the cation of the ABTS + radical.