Bis(indolyl)methane and 8-Hydroxyquinoline Derivative based Mixed Ligand Metal Complexes: Synthesis, Characterization, Antimicrobial Screening and Molecular Docking Study

Abstract

Present study described the synthesis of mixed ligand metal complexes of Mn(II), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II). Metal complexes were synthesized by two ligands such as 8-hydroxyquinoline derivative (primary ligand) and bis(indolyl)methane derivative (secondary ligand). The ligands and their transition metal complexes were characterized by IR, 1H NMR, mass spectrum, elemental analysis, TGA, electronic spectra (UV) and molar conductance. The results of analysis predicted that both ligands are bidentate and resulting complexes are ML1L2 type with molar ratio 1:1:1. To screen their biological potential, the antibacterial and antifungal activity of synthesized compounds have also been investigated. Results of antimicrobial activity were expressed as minimum inhibitory concentration (MIC). Synthesized complexes showed moderate to excellent antimicrobial activity against pathogens. Further, the more potent antimicrobial complexes of Fe(II) and Co(II) were docked with topoisomerase II as a receptor protein, Fe-complex bound to Met1113 (2.53 Å), Asn1296 (2.86 Å) and with nucleotide DC12 (3.28 Å). Similarly, Co-complex bound to Lys1276 (2.27 Å), Leu1280 (2.40 Å), Thr1325 (2.37 Å) and Gly1332 (2.42 Å) via intermolecular hydrogen bonding.