Antibacterial Activity Screening Of an Imine Compound Synthesized Using a Cinnamaldehyde Derivative Against Staphylococcus Aureus Strains

Imine pharmacophore groups offer the advantage of serving as the foundation for various drug representatives. Examples include furazolidone for bacterial or protozoal diarrhea, nitrofurantoin for uncomplicated urinary tract infections, and imbruvica for chronic lymphocytic leukemia and mantle cell lymphoma. Cinnamaldehyde, a major constituent of cinnamon oil, is an aromatic compound with a benzene ring and an aldehyde group attached to an unsaturated C=C bond at both ends. Studies on cinnamaldehyde have shown that it exhibits a broad range of biological activities. A novel imine compound, created using trans-cinnamaldehyde and polyamines such as tris (2-aminoethyl) amine (compound 5), was synthesized. The antibacterial activity of the compound was tested against clinical isolates (S. aureus, S. aureus ATCC 6538, S. aureus ATCC 25923, S. aureus UAMS-1, and S. aureus UAMS -929) using the two-fold microdilution method. The obtained results were compared with the results of the ampicillin and gentamicin. It was revealed that the MIC of F2-112B in the case of S. aureus (8 μg/mL) were lower than the MIC of ampicillin (16 μg/mL). The MIC value of compound F2-112B was equal (16 μg/ml) to ampicillin in the case of S. aureus ATCC 6538. According to the results, compared with other strains, compound 5 showed similar activities against UAMS-929 and ATCC 25923, and its MIC values were 64 µg/ml for each strain. The MIC value was 128 µg/ml when compound 5 was tested against the S. aureus strain UAMS-1. We also examined the potential binding mode between compound 5 and bacterially derived target proteins and carried out a protein–ligand docking simulation. The docking results for PBP2a (5M18) indicated that compound 5 successfully binds to the allosteric binding site of the protein, which aligns with the binding site of Cefepime, demonstrating a high binding affinity of -8.42 Kcal/mol.