Репозиторий Университета

© 2020 Elsevier Inc. In the present study, the novel shell nanostructures of Cu-MOF compound were synthesized for the first time by effective, fast and controllable method of ultrasonic assisted reverse micelle. The Fe3O4 nanoparticle was used as core for improving the physicochemical properties and also the stability of these compounds. The results showed that Fe3O4@Cu-MOF/core-shell nanostructures have significant thermal stability compared to pure Cu-MOF samples. In fact, the TEM study verified the development of core shell nanostructures. The EDS with mapping has been applied to be sure about the existence of related elements in the final Fe3O4@Cu-MOF/core-shell nanostructure. The design of the fractional test was used to change the antibacterial properties of these compounds. This method of optimization generates structures with a high surface area that affect the antibacterial properties of the materials. Systematic studies applied in this study, as well as optimization processes, can be developed as a new strategy for controlling the physicochemical properties of the products. Fe3O4@Cu-MOF/core-shell nanostructures have shown reasonably good antibacterial activities against both Gram-positive and Gram-negative bacteria.

© 2018 MDPI AG. All rights reserved. Soil fungi are known to contain a rich variety of defense metabolites that allow them to compete with other organisms (fungi, bacteria, nematodes, and insects) and help them occupy more preferential areas at the expense of effective antagonism. These compounds possess antibiotic activity towards a wide range of other microbes, particularly fungi that belong to different taxonomical units. These compounds include peptaibols, which are non-ribosomal synthesized polypeptides containing non-standard amino acid residues (alpha-aminoisobutyric acid mandatory) and some posttranslational modifications. We isolated a novel antibiotic peptide from the culture medium of Emericellopsis alkalina, an alkalophilic strain. This peptide, called emericellipsin A, exhibited a strong antifungal effect against the yeast Candida albicans, the mold fungus Aspergillus Niger, and human pathogen clinical isolates. It also exhibited antimicrobial activity against some Gram-positive and Gram-negative bacteria. Additionally, emericellipsin A showed a significant cytotoxic effect and was highly active against Hep G2 and HeLa tumor cell lines. We used NMR spectroscopy to reveal that this peptaibol is nine amino acid residues long and contains non-standard amino acids. The mode of molecular action of emericellipsin A is most likely associated with its effects on the membranes of cells. Emericellipsin A is rather short peptaibol and could be useful for the development of antifungal, antibacterial, or anti-tumor remedies.

© 2018, © 2018 Taylor  &  Francis. A library of 29 2-amino-6-sulfanylpyridine-3,5-dicarbonitriles functionalized with a pyridoxine moiety was synthesized using a three-component one-pot reaction of aldehyde derivative of pyridoxine, malononitrile, and thiophenol. The obtained bipyridine structures were converted into methylpyridinium salts. Several compounds demonstrated expressed antibacterial activity with MICs (minimum inhibitory concentrations) in the range of 0.5–4 µg/mL against the three studied Gram-positive strains and 8–64 µg/mL against the Gram-negative E. coli strain, which was comparable or better than the activity of the reference antimicrobial agents. At the same time, all the synthesized compounds were inactive against the Gram-negative P. aeruginosa. Several compounds also demonstrated high cytotoxic activity against the studied tumor cells, but without selectivity for the normal HSF (human foreskin fibroblast) cells. Despite the preliminary character of the performed biological studies, the obtained results make the obtained structural chemotype a promising starting point for the design of physiologically active compounds.