An antibacterial silver(I) supramolecular network assembled from thiophene-2,5-dicarboxylate and benzimidazole

In situ facile synthesis and antibacterial activity of Ag-MOFs/cellulose filter paper composites for fruit fresh-keeping

A large number of fresh fruits are wasted in the supply chain due to spoilage, so it is crucial to develop fruit preservation materials. Herein, two novel Ag-MOFs/carboxymethyl filter paper (Ag-MOFs/CMFP) composites were successfully synthesized by in situ facile synthesis, which can be used as packaging materials to delay fruit spoilage. The synthesis process is simple and environmentally friendly, and the reaction conditions are mild. The mechanical property, water stability, and antibacterial activity of the as-synthesized Ag-MOFs/CMFP composites were investigated. Specifically, the composites exhibited high mechanical performance and the tensile strength was >10.00 MPa. Moreover, the composites displayed good water stability and can remain stable in water environment for >7 days, which can be attributed to the strong interaction between Ag-MOFs and CMFP. Significantly, Ag-MOF particles endow the composite papers with excellent antibacterial activity, which can inactivate 99.9 % of the bacteria. Attributed to these characteristics, these composite papers were used as fruit fresh-keeping materials and can prolong the shelf-life of cherry tomatoes and peaches for >10 days. This research not only provides a facile synthesis strategy for the flexible MOFs paper, but also provides instructive guidance for related research on fruit preservation materials.

Synthesis, antimicrobial activity and molecular docking study of benzyl functionalized benzimidazole silver(I) complexes

In this study, a series of N-functionalized benzimidazole silver(I) complexes were prepared and characterized by FT-IR, 1H, 13C{1H} NMR spectroscopy, and elemental analysis. Synthesized N-benzylbenzimidazole silver(I) complexes were evaluated for their antimicrobial activities against bacteria Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and the fungal strains Candida albicans and Candida glabrata. The results indicated that N-alkylbenzimidazole silver(I) complexes exhibited good antimicrobial activity compared to N-alkylbenzimidazole derivatives. Especially, complex 2e presented perfect antimicrobial activity than the other complexes. The characterized molecules were optimized by DFT-based calculation methods and the optimized molecules were analyzed in detail by molecular docking methods against bacterial DNA-gyrase and CYP51. The amino acid residues detected for both target molecules are consistent with expectations, and the calculated binding affinities and inhibition constants are promising for further studies. A series of N-alkylbenzimidazole silver(I) complexes were synthesized and fully characterized by means of 1H NMR, 13C NMR, and FT-IR spectroscopies. Synthesized N-alkylbenzimidazole silver(I) complexes were investigated for their antimicrobial activities against bacteria Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and the fungal strains Candida albicans and Candida glabrata. All complexes showed better activity according to Ampicilin against Pseudomonas aeruginosa. The molecules which were firstly optimized by DFT-based calculation methods were also analyzed by molecular docking methods against DNA gyrase of E. Coli and CYP51. 338 × 190 mm (96 × 96 DPI).

Design, synthesis, antimicrobial activity and molecular docking study of cationic bis-benzimidazole-silver(I) complexes

Two series of bis(1-alkylbenzimidazole)silver(I) nitrate and bis(1-alkyl-5,6-dimethylbenzimidazole)silver(I) nitrate complexes, in which the alkyl substituent is either an allyl, a 2-methylallyl, an isopropyl or a 3-methyloxetan-3-yl-methyl chain, were synthesized and fully characterized. The eight N-coordinated silver(I) complexes were screened for both antimicrobial activities against Gram-negative (Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Acinetobacter baumannii) and Gram-positive (Staphylococcus aureus, Staphylococcus aureus MRSA, and Enterococcus faecalis) bacteria and antifungal activities against Candida albicans and Candida glabrata strains. Moderate minimal inhibitory concentrations (MIC) of 0.087 μmol/mL were found when the Gram-negative and Gram-positive bacteria were treated with the silver complexes. Nevertheless, MIC values of 0.011 μmol/mL, twice lower than for the well-known fluconazole, against the two fungi were measured. In addition, molecular docking was carried out with the structure of Escherichia coli DNA gyrase and CYP51 from the pathogen Candida glabrata with the eight organometallic complexes, and molecular reactivity descriptors were calculated with the density functional theory-based calculation methods.

Thiophene-containing compounds with antimicrobial activity

Thiophene, as a member of the group of five-membered heterocycles containing one heteroatom, is one of the simplest heterocyclic systems. Many synthetic strategies allow the accurate positioning of various functionalities onto the thiophene ring. This review provides a comprehensive, systematic and detailed account of the developments in the field of antimicrobial compounds featuring at least one thiophene ring in their structure, over the last decade.

Reactive organic radical-doped Ag(I)-based coordination compounds for highly efficient antibacterial wound therapy

Antibiotics, being critical antimicrobial agents, have been widely used for treating bacterial infections. However, prolonged use of antibiotics can induce drug resistance resulting in "superbug" that threatens human health. Therefore, developing antibiotic-free materials with intrinsic antibacterial properties is the key to the "superbug" challenge. In this study, two highly efficient metal-organic frameworks (MOFs) were successfully assembled through synergistic use of the antibacterial properties of reactive organic radicals and silver (Ag) cations. These hybrid Ag-based materials possessed radical-doped characteristics, continuously releasing Ag⁺, which significantly inhibited the growth of four common Gram-negative and Gram-positive human pathogens (Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, and Staphylococcus aureus), and particularly two multi-drug-resistance bacteria (MRSA and MDR-PA). Furthermore, in vivo assays indicated that the synergistic antibacterial effect of these compounds could significantly accelerate the healing rate of infected wounds in mice. Blood biochemistry and histological analyses of main organs in treated mice also exhibited negligible cytotoxicity. This study unveiled the promising potential of Ag-MOFs for anti-infective therapies and future clinical applications.

Copper(ii)-based coordination polymer nanofibers as a highly effective antibacterial material with a synergistic mechanism

Nanofibers of a copper(ii)-based coordination polymer [Cu(HBTC)(H₂O)₃] were synthesized via a microwave-assisted hydrothermal process, while macroparticles and bulk crystals were prepared via a hydrothermal method. X-ray analysis revealed that this compound possesses one-dimensional zig-zag chains, in which the coordination polyhedron of the copper(ii) center is a five-coordinate distorted square-pyramid. The width of the as-prepared nanofibers was about 150 nm, while the size of the macroparticles was about 200 μm. The antibacterial activities of the nanofibers and macroparticles against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were evaluated by determining the minimal inhibitory concentration (MIC), the growth curve of the bacteria and the bacterial reduction assay. The nanofibers showed higher antibacterial performance as compared with macroparticles, commercial copper nanoparticles, and pure ligands alone. The bacteriostatic rates of nanofibers and macroparticles were up to 99.9% and 96.7% against E. coli, while 99.1% and 96.2% against S. aureus, respectively, when the concentration was 250 μg mL^-1. The synergistic antibacterial mechanism was also proposed based on the generation of reactive oxygen species (ROS) and the release of Cu²⁺ ions.