Abstract
A monobasic bidentate ligand (H2L) was prepared from the reaction of cyanoacetic acid hydrazide with 1-(4-((1H-imidazol-2-yl)sulfonyl) phenyl) ethanone (ISE) in ethanol. A new series of Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Ag(I) and Zn(II) metal complexes of H2L ligand was synthesised. The interaction of the H2L ligand with salicyaldehyde and naphthaldehyde afforded coumarin and benzocoumarin derivatives, respectively. Structural characterisation of the newly synthesised compounds was achieved by elemental analysis, thermogravimetric analysis TGA, electrical molar conductance and spectral techniques, such as IR, UV, H-1 NMR, C-13-NMR and ESR, as well as by magnetic moment measurements. The reported ligand (H2L) is monobasic dibasic with an N-O bidentate set, which coordinated with the metal ions to produce the metal complexes. The N atom of CH=N functioned coordinately with the O atom of carbonyl in the ligand. The prepared novel compounds were assessed for their antimicrobial activities. Fe(III), Co(II), Ni(II) and Ag(I) compounds showed good activity against Gram (-ve) bacteria. The newly synthesised compounds were assessed for their in vitro anticancer activity against both MCF-7 and HCT-116 cell lines; normal fibroblasts of the baby hamster kidney (BHK) cell line were also assessed. Ni(II) and Ag(I) complexes exhibited significant activity towards the MCF-7 and HCT-116 cell lines. Cu(II) and Fe( III) complexes exhibited better activity in the MCF-7 cell line, while Zn(II) and benzocoumarin compounds showed better activity in the HCT-116 cell line compared to doxorubicin (DOX) as a reference drug. Molecular docking was used to illustrate interaction among components within the active sites of dihydrofolate reductase (DHFR).