Synthesis, characterization, antimicrobial, and docking study of novel 1-(furanyl)-3-(pyrrolyl)propenone-based ligand and its chelates of 3d-transition metal ions

The novel ligand (L) 1-(furanyl)-3-(pyrrolyl)propenone had been synthesized, and its novel chelates of some 3d series of transition metal ions had been prepared and characterized. The structural properties of the titled compounds were explored using elemental analyses, spectroscopic techniques (UV-visible, MS, and FT-IR), molar conductivity, and magnetic susceptibility measurements. The scanning electron microscope (SEM) showed that the ligand and its metal chelates exist in stick crystallized structures and sizes of their molecules can exist in nanoform. Thermal analyses techniques (TG and DTA) measured the investigated chelates during their thermal degradation to elucidate their structures. It was proved that ligand (L) acts as bibasic bidentate ligand coordinating to metal cations via its two oxygen atoms of carbonyl and epoxy groups. The optimization of the structural formula for the examined ligand had been performed by using Gaussian 09 program. The energy gaps were calculated using the DFT/B3LYP method. The ligand and its chelates had been fixed to have consistent bond lengths and bond angles that proved via quantum chemical factors. The ligand (L) and its transition metal chelates had been tested for their antibacterial activities. In vitro biological properties for ligand (L) and its transition metal complexes were carried out against Gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) by agar diffusion technique. The results showed that title compounds are biologically active than the parent ligand in their sticks crystalline and possible nanostructures and consequently large surface interactions. Molecular docking showed favorable interaction between ligand and crystal structures of 3t88 E. coli, 3ty7 S. aureus, 5h67 B. subtilis, and 5i39 P. aeruginosa. This docking study proved that nanosize of ligand helps it to interact efficiently with proteins of bacteria.