Antibacterial Activities of Azole Complexes Combined with Silver Nanoparticles

Abstract

Growing antimicrobial resistance is considered a potential threat for human health security by health organizations, such as the WHO, CDC and FDA, pointing to MRSA as an example. New antibacterial drugs and complex derivatives are needed to combat the development of bacterial resistance. Six new copper and cobalt complexes of azole derivatives were synthesized and isolated as air-stable solids and characterized by melting point analyses, elemental analyses, thermogravimetric analyses (TGA), and infrared and ultraviolet/visible spectroscopy. The analyses and spectral data showed that the complexes had 1:1 (M:L) stoichiometries and tetrahedral geometries, the latter being supported by DFT calculations. The antibacterial activities of the metal complexes by themselves and combined with silver nanoparticles (AgNPs; 2 μg mL−1) were assessed in vitro by broth microdilution assays against eight bacterial strains of clinical relevance. The results showed that the complexes alone exhibited moderate antibacterial activities. However, when the metal complexes were combined with AgNPs, their antibacterial activities increased (up to 10-fold in the case of complex 5), while human cell viabilities were maintained. The minimum inhibitory concentration (MIC50) values were in the range of 25–500 μg mL−1. This study thus presents novel approaches for the design of materials for fighting bacterial resistance. The use of azole complexes combined with AgNPs provides a new alternative against bacterial infections, especially when current treatments are associated with the rapid development of antibiotic resistance.

Sensitive and Profitable Electrochemical Detection of Uric Acid in the Presence of Dopamine with a Novel Carbon Paste Electrode Decorated with a Copper(II) Complex

“…The electrochemical properties of the carbon paste surface decorated with Cu C were investigated via EIS and CV using 10.0 mmol L À 1 K 4 Fe(CN) 6 in 10.0 mmol L À 1 KCl as the test electrolyte. Moreover, the presence of metals ions, such as copper ions, was assessed via EDS.We previously studied the synthesis and characterization of copper(II) complexes derived from azole and they have received considerable attention due to their low cost, easy preparation, air-stable and electroactive properties [24][25][26][27] In the CV measurement for the ferri/ferrocyanide couple with CPE and Cu C /CPE ( Figure 1A), the anodic and cathodic peak potentials were observed at almost the same potential values of 0.66 V and À 0.20 V, respectively, with a ΔE of 0.81 V, indicating a quasi-reversible redox reaction. However, the anodic and cathodic peak currents increased by almost 30.6 % and 55.1 %, respectively, with the CPE decorated with Cu C .…”

Development of Antibacterial and Antifungal Triazole Chromium(III) and Cobalt(II) Complexes: Synthesis and Biological Activity Evaluations

“…The combination of metals and azoles is a promising strategy to develop new efficient drugs, even against drug-resistant pathogens [ 17 , 18 , 19 , 20 , 21 , 22 ]. The development of these new drugs is related to the complexation of azole derivatives with transition metals that have low toxicity and are biocompatible [ 18 , 23 , 24 ]. Previous studies demonstrated that the resulting complexes may have higher antimicrobial activity than the corresponding free azole ligands, and, in some cases, exceeding that of standard test substances (nystatin) [ 25 , 26 ].…”

Water Dissociation of a Dinuclear Bis(3,5‐dimethylpyrazolyl)methane Copper(II) Complex: X‐ray Diffraction Structure, Magnetic Properties, and Characteristic Absorption of the (CuN2Cl2)2 Core

“…In 2007, the synthesis and crystalline structure of a monomeric compound of L and CuCl 2 , produced by the reaction of N ‐hydroxymethyl‐3,5‐dimethylpyrazole with CuCl 2 in a 2:1 ratio in ethanol, was reported, supporting the work of Mesubi and Anumba. The reaction between L and CuCl 2 , yielding a yellow complex, has also been previously reported, and the compound is considered to be a monomeric compound, as well , , , . However, the yellow complex had not been characterized by single‐crystal X‐ray diffraction, which led us to inquire about the structural identity of this compound.…”