Phenanthroline-based Ni(II) coordination compounds involving unconventional discrete fumarate-water-nitrate clusters and energetically significant cooperative ternary π-stacked assemblies: Antiproliferative evaluation and theoretical studies

Synergistic antibacterial action of the iron complex and ampicillin against Staphylococcus aureus

OBJECTIVES

Resistance to antibiotics among bacteria of clinical importance, including Staphylococcus aureus, is a serious problem worldwide and the search for alternatives is needed. Some metal complexes have antibacterial properties and when combined with antibiotics, they may increase bacterial sensitivity to antimicrobials. In this study, we synthesized the iron complex and tested it in combination with ampicillin (Fe16 + AMP) against S. aureus.

METHODS

An iron complex (Fe16) was synthesized and characterized using spectroscopy methods. Confirmation of the synergistic effect between the iron complex (Fe16) and ampicillin (AMP) was performed using ζ-potential, infrared spectra and FICI index calculated from the minimum inhibitory concentration (MIC) from the checkerboard assay. Cytotoxic properties of combination Fe16 + AMP was evaluated on eukaryotic cell line. Impact of combination Fe16 + AMP on chosen genes of S. aureus were performed by Quantitative Real-Time PCR.

RESULTS

The MIC of Fe16 + AMP was significantly lower than that of AMP and Fe16 alone. Furthermore, the infrared spectroscopy revealed the change in the ζ-potential of Fe16 + AMP. We demonstrated the ability of Fe16 + AMP to disrupt the bacterial membrane of S. aureus and that likely allowed for better absorption of AMP. In addition, the change in gene expression of bacterial efflux pumps at the sub-inhibitory concentration of AMP suggests an insufficient import of iron into the bacterial cell. At the same time, Fe16 + AMP did not have any cytotoxic effects on keratinocytes.

CONCLUSIONS

Combined Fe16 + AMP therapy demonstrated significant synergistic and antimicrobial effects against S. aureus. This study supports the potential of combination therapy and further research.

Fumarato and Phthalato Bridged Dinuclear Metal-Organic Cu(II) and Mn(II) Compounds involving Infinite Fumarate-water Assemblies and Unusual Structure-guiding H-bonded Synthons: Antiproliferative Evaluation and Theoretical Studies

Two new dinuclear coordination compounds viz. [Cu2(µ-fum)(phen)2(H2O)6](fum)•6H2O (1) and [Mn2(µ-phth)2(phen)4]•2H2O (2) (phen = 1,10-phenanthroline, fum = fumarate and phth = phthalate) have been synthesized and characterized by elemental analysis, single...

Structural topologies involving energetically significant antiparallel π-stacking and unconventional N(nitrile)⋯π(fumarate) contacts in dinuclear Zn(ii) and polymeric Mn(ii) compounds: antiproliferative evaluation and theoretical studies

Anticancer activities considering cell viability, apoptosis and molecular docking have been explored in dinuclear Zn(ii) and polymeric Mn(ii) compounds involving energetically significant unconventional N(nitrile)⋯π(fum) contacts.

Solvent-driven structural topologies in phenanthroline-based co-crystals of Zn(ii) involving fascinating infinite chair-like {[(bzH)4Cl2]2−}n assemblies and unconventional layered infinite {bz-H2O-Cl}n anion-water clusters: antiproliferative evaluation and theoretical studies

Anticancer activities considering cell cytotoxicity, apoptosis and molecular docking have been explored in Zn(ii) co-crystals of phenanthroline involving infinite chair-like assemblies and unconventional layered infinite anion-water clusters.

Coordination complexes of zinc and manganese based on pyridine-2,5-dicarboxylic acid N-oxide: DFT studies and antiproliferative activities consideration

We report here the design, synthesis, and antiproliferative activity of three coordination complexes [Mn₂(pydco)₂(bpy)₂(H₂O)₂]·2H₂O (1), [Zn(bpy)(Hpydco)₂] (2), and [Zn(bpy)Cl(Hpydco)]·2H₂O (3) (H₂pydco = pyridine-2,5-dicarboxylic acid N-oxide, bpy = 2,2'-bipyridine). Molecular structures of these complexes have been characterized by elemental analysis, Fourier transform infrared spectroscopy, thermogravimetric analysis, and powder and single-crystal X-ray diffraction. According to the structural analysis, 1-3 are discrete complexes containing N- and O-donor ligands (bpy and pydco^2-) in which pydco^2- can be coordinated to the metal centres via the N-oxide oxygen and one carboxylate oxygen to generate a six-membered chelate ring. Also, these structures benefit from extensive intermolecular interactions such as hydrogen bonds and π-interactions which are the major forces to make them more stable in the solid state. The energetic features of the π-stacking interactions observed in compounds 1-3 have been computed and compared to the H-bonds. The interactions in the solid state have been also studied using the independent gradient model approach (IGM plot). The IGM-δg approach uses a new descriptor (δg) that locally represents the difference between a virtual upper limit of the electron density gradient and the true electron density gradient. This newly developed IGM methodology automatically extracts the signature of interactions between two given fragments. Finally, the antiproliferative properties of these complexes were tested on several cancer cell lines by MTT assay and flow cytometry. Also, to compare the antiproliferative activities of these complexes with common chemotherapy drugs, the antiproliferative property of cisplatin was evaluated as a reference and positive control.