Synthesis, characterization and biological evaluation of heterocyclic triazole derived Schiff base ligands comprising Mn(II) complexes: Implications of their DNA/protein binding docking and anticancer activity studies

Abstract

Schiff base ligands comprising heterocyclic moieties deserve distinct consideration because of their excellent chemotherapeutic and antioxidant properties as biologically active agents. In present investigation, two novel heterocyclic triazole derived Schiff base ligands have been synthesized using 3-chlorobenzaldehyde (L1), 4-methoxybenzaldehyde (L2) with 1H-1,2,4-triazol-3-amine backbone that are biologically active. Mn(II) complexes have been synthesized by combing ligands in 1:2 molar ratio (metal:ligand), their structure and bonding nature are recognised by respective physical, spectral and analytical data. The ligands (L1 & L2) and their metal complexes are characterized by elemental analyses, electronic, FT-IR, 1H and 13C NMR and EPR spectroscopy techinques. Antimicrobial activity of the synthesized L1, L2 and their metal complexes are tested against Bacillus subtilis (Gram-positive, catalase-positive bacterium) as well as Fungi namely Phylium Aphanidematum, Macrophomina phasiolina, Fusarium oxysporum. Both the ligands and metal complexes exhibit excellent antimicrobial activity under low inhibitory concentration such MIC ≤ 250 μg/mL. Upon co-ordination, antimicrobial properties have been enhanced by 21%. The anticancer activity of the synthesized complex has been investigated against human tumour cell lines (Breast cancer MCF-7 cells) demonstrated that L1M complex displays potent inhibition against MCF-7. Using this molecular docking study, we can predict the complex–biomolecular interaction and it plays vital role in the drug discovery and also it is a step by step process which is used to place synthesised compounds into the binding sites of the DNA molecule. Further, Molecular DNA docking results demonstrated encouraging responses, thereby opening up new avenues for the application of the synthesized inorganic triazole derivative complexes as leads for the development of novel anti-cancer drugs.