Coordination compounds of pyrazolone-based ligand: Design, characterization, biological evaluation, antitumor efficiency, and DNA binding evaluation supported by in silico studies

Cu (II), Ni (II), Mn (II), and Cr (III) chelates of the organic ligand named 3-(furan-2-yl)-5-oxo-N,1-diphenyl-4,5-dihydro-1H-pyrazole-4-carbothioamide ligand (abbreviated as H2L) have been obtained. Successful structure elucidation of the ligand and its chelates has been managed by applying alternative spectral and analytical techniques including elemental analysis, inductively coupled plasma (ICP), NMR, mass, and FTIR spectra in addition to molar conductance and TGA technique which all joint confirmed the formation of the metal complexes in the molar ratio 1:2 (M:L) for Cu (II) and Mn (II) chelates, while 1:1 for the rest of complexes. The applied techniques also confirmed the metal complexes to be formulated as [Cu (HL)(2)(H2O)(2)]center dot 0.5H(2)O, [Ni (HL)(H2O)Cl]center dot 0.5H(2)O, [Mn (HL)(2)(H2O)(2)]center dot 2H(2)O and [Cr (HL)(H2O)(2)(CH3COO)(2)]center dot 2.5H(2)O, where HL is the organic ligand. UV-Vis spectra and mu(eff) values of the metal chelates assured the geometry around the metal ion center to be octahedral for both Cu (II), Mn (II), and Cr (III) complexes. For the Ni (II) complex, tetrahedral arrangement has been concluded. The in vitro antimicrobial efficacy applied on several microorganisms and the antioxidant activity showed biological activities in relation to employed standard reported compounds with enhanced activity of the Cr (III) complex compared with the other tested compounds. The antitumor activity was examined upon four carcinoma cell lines that are HePG-2 MCF-7, HCT-116, and HeP-2 demonstrated that the Cr (III) complex to has the highest activity against the four tested carcinoma cell lines relative to the other tested compounds. The binding mode of the ligand and its complexes with SS-DNA have been examined applying UV-Vis spectral titration and viscosity measurements, assuring groove binding interactions, which were supported theoretically through the docking studies.