Synthesis, spectroscopic and thermal studies of Cu+2, Ni+2and Co+3complexes of Schiff base containing furan moiety. Antitumor, antioxidant, antibacterial and DNA interaction studies

Abstract

Three mononuclear bioefficient imine‐based coordination complexes [Cu(FMIMBCP)2] (1), [Ni(FMIMBCP)2] (2), and [Co(FMIMBCP)3] (3) were synthesized using ligand [FMIMBCP = (((furan‐2‐yl)methylimino)methyl)‐6‐bromo‐4‐chlorophenol]. The formation of the complexes was ascertained by elemental analysis, Fourier transform infrared, UV–Visible, electrospray‐mass spectrometry, electron paramagnetic resonance, and thermogravimetric analysis. From the thermogravimetric curves, the kinetic and thermodynamic parameters of the thermal degradation steps were computed. The stability of the complexes has been calculated from quantum chemical parameters using HOMO‐LUMO energies. The comparative binding propensity profiles of above synthesized complexes with thecalf thymus‐DNA were investigated via UV absorption and fluorescence studies. On the basis of extended conjugation and increased chromophores, complex3exhibited superior bioactivity with greater calculated DNA binding constant values, (Kb) 5.73 × 104 M−1(3) as compared to complexes1(2.96 × 104 M−1) and2(8.38 × 103 M−1). The competitive binding titration with ethidium bromide (EB) revealed that metal complexes efficiently displace EB from the EB‐DNA system. The complexes were found to have pronounced cleavage efficiency as evaluated from agarose gel electrophoresis. The anticancer activity of the ligand and metal complexes against MCF‐7 and KB3 cells revealed that the complexes were more efficacious than the corresponding ligand. Further, in vitro antioxidant activity against DPPH proclaimed the remarkable bioefficiency of compounds, which makes them promising as an active chemotherapeutic agent. The complexes have strong antibacterial activity againstBacillus thuringiensis,Streptococcus pneumoniae,Escherichia coli, andPseudomonas putida.