Design, synthesis, antioxidant, antimicrobial, DNA binding and molecular docking studies of morpholine based Schiff base ligand and its metal(II) complexes

Abstract

Morpholine based Schiff base ligand (L) and its metal(II) complexes of the type [ML]X2, where M = Cu(II), Co(II), Ni(II), and Zn(II); L = Ligand; X = OAc, have been synthesized and characterized by elemental analysis, by means of 1H NMR, FT-IR, UV–Visible, mass and ESR spectroscopic method. Analytical and mass spectrometric results have shown that ligand to metal is in 1:1 stoichiometric ratio. 1H NMR and FT-IR spectroscopic results revealed that ligand is coordinated with central metal atom through an azomethine and morpholine nitrogen atoms. UV–Visible, mass and ESR spectroscopic results have shown that the proposed structure of metal complexes has square planar geometry. Antioxidant activity of L and its complexes have been tested against stable free radical DPPH (2,2-diphenyl-1-picrylhydrazyl) and the results have shown that L and its complexes have good scavenging ability. Antimicrobial activities of L and its complexes have been screened against selected bacterial (B. subtilis, E. coli, and Stap. aureus) and fungal (A. niger, C. albicans and M. indicus) strains. Moreover, L and its complexes have better antimicrobial activity againt B. subtilis bacteria and C. albicancs fungi than the other antimicrobial species. These results reveal that prepared metal(II) complexes act as good antimicrobial agents better than L. DNA binding of L and its complexes have been probed with calf thymus DNA (CT-DNA) by electronic absorption and viscometric measurements. The result indicates that L and its complexes may be interacting with DNA towards intercalative interaction mode. Molecular docking activities of metal(II) complexes with CT-DNA have been carried out.