Synthesis and structural studies of 1-phenyl-1,3-butanedione copper(II) complexes as an excellent antimicrobial agent against methicillin-resistant Staphylococcus aureus

Copper(II) carboxylate complexes inhibit Staphylococcus aureus biofilm formation by targeting extracellular proteins

Three copper(II) complexes of diphenyl acetic acid (DPAA) pyridine (py), 2,2΄-dipyridylamine (dpa), and 4,7-diphenyl, 1,10-phenanthroline (di-phen), [Cu₂(DPAA)₄(py)2] (Cu-1), [Cu(DPAA)₂(dpa)] (Cu-2), and [Cu₂(DPAA)₄(di-phen)₂] (Cu-3) were synthesized and characterized. Their antibacterial activities were evalvated. The minimum inhibitory concentrations (MIC) of these complexes against six tested microbial strains ranged from 1 to 128 μg/mL, and that of vancomycin antibiotic ranged from 0.5 to 2 μg/mL. The bactericidal effects of Cu-1, Cu-2 and Cu-3 and vancomycin against Staphylococcus aureus (S. aureus) were determined by colony count assay. Cu-1, Cu-2, and vancomycin showed relatively weaker antibiofilm formation activities; however, Cu-3 showed enhanced activity against S. aureus proliferation and biofilm formation as confirmed by microscopic analysis. In antibiofilm assays, Cu-1, Cu-2 and Cu-3 demonstrated high inhibition ability (23-75 %), of mature biofilm formation at concentrations of 5 to 15 μg/mL, and vancomycin at 15 μg/mL inhibited only 47 %. Cu-3 also effectively killed S. aureus within biofilms at doses up to 2 × MIC μg/mL. Further analysis of extracellular proteins (ECPs) expression revealed, that Cu-3 had significant potential in suppressing ECPs production. Molecular docking (MD) studies with biofilm associated protein (Bap) and SARS-CoV-2 receptors showed high interactions by several bonding types, where Cu-2 found as potent antiviral agent. Collectively, these findings highlighted the copper complexes potential in antibacterial applications, with Cu-3 emerging as a potent candidate for S. aureus biofilm inhibition.

Unsymmetrical Trifluoromethyl Methoxyphenyl β-Diketones: Effect of the Position of Methoxy Group and Coordination at Cu(II) on Biological Activity

Copper(II) complexes with 1,1,1-trifluoro-4-(4-methoxyphenyl)butan-2,4-dione (HL1) were synthesized and characterized by elemental analysis, FT-IR spectroscopy, and single crystal X-ray diffraction. The biological properties of HL1 and cis-[Cu(L1)₂(DMSO)] (3) were examined against Gram-positive and Gram-negative bacteria and opportunistic unicellular fungi. The cytotoxicity was estimated towards the HeLa and Vero cell lines. Complex 3 demonstrated antibacterial activity towards S. aureus comparable to that of streptomycin, lower antifungal activity than the ligand HL1 and moderate cytotoxicity. The bioactivity was compared with the activity of compounds of similar structures. The effect of changing the position of the methoxy group at the aromatic ring in the ligand moiety of the complexes on their antimicrobial and cytotoxic activity was explored. We propose that complex 3 has lower bioavailability and reduced bioactivity than expected due to strong intermolecular contacts. In addition, molecular docking studies provided theoretical information on the interactions of tested compounds with ribonucleotide reductase subunit R2, as well as the chaperones Hsp70 and Hsp90, which are important biomolecular targets for antitumor and antimicrobial drug search and design. The obtained results revealed that the complexes displayed enhanced affinity over organic ligands. Taken together, the copper(II) complexes with the trifluoromethyl methoxyphenyl-substituted β-diketones could be considered as promising anticancer agents with antibacterial properties.

Recent Studies on the Antimicrobial Activity of Transition Metal Complexes of Groups 6–12

Antimicrobial resistance is an increasingly serious threat to global public health that requires innovative solutions to counteract new resistance mechanisms emerging and spreading globally in infectious pathogens. Classic organic antibiotics are rapidly exhausting the structural variations available for an effective antimicrobial drug and new compounds emerging from the industrial pharmaceutical pipeline will likely have a short-term and limited impact before the pathogens can adapt. Inorganic and organometallic complexes offer the opportunity to discover and develop new active antimicrobial agents by exploiting their wide range of three-dimensional geometries and virtually infinite design possibilities that can affect their substitution kinetics, charge, lipophilicity, biological targets and modes of action. This review describes recent studies on the antimicrobial activity of transition metal complexes of groups 6–12. It focuses on the effectiveness of the metal complexes in relation to the rich structural chemical variations of the same. The aim is to provide a short vade mecum for the readers interested in the subject that can complement other reviews.

Solvent induced mononuclear and dinuclear mixed ligand Cu(ii) complex: structural diversity, supramolecular packing polymorphism and molecular docking studies

Phenolate bridged dinuclear and solvent induced mononuclear supramolecular isomers of Cu(ii) complex have been reported to explore the structural diversity and their antibacterial activity supported by molecular docking studies.