Bis(imidazol-1-yl)methane-based heteroscorpionate metal(II) complexes: Theoretical, antimicrobial, antioxidant, in vitro cytotoxicity and c-Met tyrosine kinase studies

Abstract The C-centered bis(imidazole-1-yl)methane-based heteroscorpionatemetal(II) complexes of the type [M(L 1−3 )Cl] ( 1 – 9 ), where M = Mn(II), Ni(II) or Cu(II) have been synthesized using the heteroscorpionate ligands, (2-hydroxyphenyl)bis(imidazole-1-yl)methane (HL 1 ), (4-diethylamino-2-hydroxyphenyl)bis(imidazole-1-yl)methane (HL 2 ) and (5-bromo-2-hydroxyphenyl)bis(imidazole-1-yl)methane (HL 3 ). The spectral and theoretical studies suggested tetrahedral geometry for manganese(II) and nickel(II) complexes, and square-planar geometry for copper(II) complexes. The antimicrobial activity of the complexes was evaluated against two Gram (–ve) ( Shigella dysenteriae and Vibrio cholerae ) and two Gram (+ve) ( Bacillus cereus and Streptococcus faecalis ) bacterial, and three fungal ( Candida albicans, Candida glabrata and Candida krusei ) strains. The antioxidant activity of the ligands and their nickel(II) and copper(II) complexes were determined by ABTS, DPPH and H 2 O 2 free radical scavenging assays. In vitro cytotoxicity activity of the ligands and their nickel(II) and copper(II) complexes were tested against human breast adenocarcinoma (MCF-7), cervical (HeLa) and lung (A549) cancerous and normal human dermal fibroblast (NHDF) cell lines by MTT reduction assay. The copper(II) complex 8 exhibit higher cytotoxicity activity than the other complexes against all the tested cancer cell lines. Molecular docking studies of the complexes were also performed with c -Met tyrosine kinase receptor to determine the possible binding mode and predominant binding interactions.