INORGANIC CHEMISTRY COMMUNICATIONS, cilt.173, 2025 (SCI-Expanded)
The molecular structure and redox properties of benzoylthiourea compounds provide high biological activity of these compounds. The activity of these compounds in biological systems is generally increased when they are converted into metal complexes and when they form mixed ligand complexes with an active coligand. In this study, four new M(II) complexes having formula [ML(aa)(H2O)(2)] where M = Mn and Cu, L = deprotonated 1benzoyl-3-(benzimidazolyl)thiourea and aa = deprotonated phenylalanine and tyrosine have been synthesized via complexation of corresponding M(II) acetate with HL and amino acids originally. Elemental analysis, Ir spectra, thermal analysis, molar conductivity, and magnetic measurements were carried out to elucidate the structure of the obtained compounds. The electrochemical behavior of the complexes was determined by cyclic voltammetry, which shows that the chelate and electron donating effects of the ligands are among the factors influencing the redox potentials of the complexes. Additionally, the antioxidant activities of compounds were determined using the 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity and Cupric Ion Reducing Antioxidant Capacity methods. IC50 and TEAC values for complex 4 were calculated as 0.736 mM and 0.539, respectively. Antibacterial activity studies were conducted with the ASTM E2149 standard method, using Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) as representative Gram-positive and-negative bacteria, respectively. Although all synthesized compounds provided more than 99 % mortality rate in 24-hour contact time, complex 4 was determined to have the strongest antibacterial effect with >99.98 % (>3 log) mortality in 1 h for both bacteria; >99.9999 % (>6 log) for S. aureus and >99.99999 % (>7 log) for E. coli in 24 h. The [CuL(tyr)(H2O)(2)] (4) was found to exhibit the highest electrochemical, antioxidant, and antibacterial properties. To evaluate the antibacterial activity of complex 4, molecular docking method was also investigated to understand the molecular interaction and binding mode of the complex 4 against S. aureus (S. aureus Murb protein and MRSA) and E. coli. As a result, Complex 4 had also high binding affinity to S. aureus (S. aureus Murb and MRSA) and E. coli. with-10.8 kcal/mol,-8.5 kcal/mol and-9.4 kcal/mol binding energies supported by several hydrogen bonding, Pi-Alkyl, Pi-Sulfur and Pi-Cation interactions.