Synthesis and characterisation of novel tetradentate Schiff base complexes: Biological evaluation exploring anticancer activity towards MCF 7 cell breast cancer lines with in vitro docking studies

Abstract

A method to synthesize novel tetradentate ligand and a new series of metal complexes comprising Co (II), Fe (II), Cu (II) and Zn (II) (1-4) using 3,5-dichlorosalicylaldehyde and trans 1,2-diaminocyclohexane is described. The structural features and mode of bonding exhibited by Schiff base have been characterized by spectral methods like UV-visible, FT-IR and ESI-MS. Schiff base ligand and (1-4) complexes have displayed superior antibacterial towards both Gram positive and Gram negative bacteria. The antioxidant studies have revealed significant free radical scavenging activity towards the free radical DPPH. Theoretical molecular docking studies are performed to elucidate the interactions of synthesized compounds with biomolecules. A model illustrating specific DNA-binding of synthesized compounds and groove binding mode of DNA interaction is evolved. Cu(II) complex (3) with more pronounced biological activity (antibacterial and antioxidant) has been subjected to cytotoxicity studies against MCF-7 breast cancer cell lines through MMT assay. Cu (II) complex have exhibited stronger anti-cancer activity in comparision to ligand in that way the synergistic effects of signifying Cu Schiff base complexes illustrate the higher inhibiting efficiency of 77.2% at 320 μg/mL. The proposed study, therefore discloses potentiality of the synthesized new Schiff base derived complexes as a prodrug for cancer treatment.