Spectroscopic, density functional theory and molecular docking studies of zinc (II) and nickel (II) complexes of N′-(Furan-2-ylmethylene) furan-2-carbohydrazide as potential antibacterial drug

A furoic acid hydrazide derivative C10H8N2O3 (L), its nickel (II) and zinc (II) complexes (Ni(L)2 and Zn(L)2 respectively have been synthesized. The prepared ligand and its metal(II) complexes were characterized by melting point determination, elemental analysis, conductivity, and magnetic susceptibilities measurements, infrared, UV-visible, and 1H NMR spectroscopic techniques. In addition, the crystal structure of the ligand was determined by single-crystal X-ray diffraction techniques. DFT calculations were used in the determination of quantum chemical parameters. Based on the experimental and computational results, distorted tetrahedral geometries have been proposed for the zinc (II) and nickel (II) complexes. The antibacterial activity of the ligand and its Ni (II) and Zn (II) complexes were evaluated against three Gram-positive bacteria Methicillin-resistant Staphylococcus aureus, Staphylococcus epidermidis, and Staphylococcus aureus. The nickel (II) complex showed promising results as an antibacterial agent for Methicillin-resistant Staphylococcus aureus with MIC value of 3.12 +/- 0.13 mu g/mL as compared to the standard drug with MIC value of 2.0 +/- 0.34 mu g/mL. Furthermore, molecular docking analysis was performed and the average binding energy of Ni(L)2 with MRSA strain was extremely favourable (-8.4 kcal/mol), followed by the Zn(L)2 complex with average binding energy of -8.3 kcal/mol when docked against 1SAX. The nickel and zinc complexes had average binding energies -7.0 kcal/mol and -6.7 kcal/ mol respectively against 2D45, as compared to that of the vancomycin drug (-4.2 kcal/mol). These results revealed that, the complexes are potential candidates for the development of new MRSA drug.