卷 50, 编号 2 (2024)

A conjugate of hyaluronic acid and antimicrobial peptide LL-37 was synthesized for the first time. The hybrid compound was tested as an antimicrobial organic coating for titanium samples with an inorganic sublayer obtained by plasma electrolytic oxidation (PEO) of the surface. As a result of in vitro studies, the antibacterial effect of the hybrid molecule within the inorganic PEO coating was established, which consists of a significant (p < 0.05) suppression of the ability of Staphylococcus aureus, Pseudomonas aeruginosa, Enterococcus faecium and Escherichia coli to form biofilms. The presented approach can be utilized for the subsequent design and development of non-fouling antimicrobial coatings to decrease the risk of infectious diseases caused by bacteria when using implants.

The fatty acids and their ethyl esters from an extract of a sponge Penares sp. (South China Sea) were fractionated by high-performance liquid chromatography and analyzed by gas chromatography-mass spectrometry using pyrrolidine, 4,4-dimethyloxazoline, dimethyl disulfide, and hydrogenated derivatives. In some cases, ¹Н and ¹³С NMR spectroscopy was applied for the structural analysis of fatty acids. 71 С₁₂–С₂₈ acids, including 12 new compounds, were found. The new compounds were shown to be (5Z,9Z)-9-chloro-24-methy-5,9-pentacosadienoic, (5Z,9Z)-9-chloro-25-methyl-5,9-hexacosadienoic, (5Z,9Z)-9-chloro-24-methyl-5,9-hexacosadienoic, (5Z,9Z)-9-chloro-25-methyl-5,9-heptacosadienoic, 6-chloro-20-methyl-4-heneicosenoic, 6-chloro-19-methyl-4-heneicosenoic, 6-chloro-20-methyl-4-docosenoic, cis-17,18-methylene-tetracosanoic, 16,21-dimethyldocosanoic, 18,23-dimethyltetracosanoic, 16,18,22-trimethyltricosanoic, and 18,20,24-trimethylpentacosanoic acids. It was shown that the characteristic features of the fatty acid mixture were a high level of constituents with monomethylated chains (over 50%) and the nearly total substitution of common demospongic acids for their chloro-derivatives, previously unknown (5Z,9Z)-9-chloro-5,9-dienoic acids. The presence of analogous structural fragments in the fatty acids from Penares sp. and in some biologically active secondary metabolites from Penares sponges was discussed. The results of this work may be used for the structural, comparative and biosynthetic studies of marine lipids.

The mammal microbiome is considered an attractive source of bioactive compounds, including antibiotics. In this work, we studied cultivable microorganisms from the nasal microbiota of the Hungarian domestic pig (Sus domesticus). Taxonomy positions of the 20 isolated strains (18 bacteria, 1 yeast, 1 fungus) were determined by phylogenetic analysis, morphological study and a substrate utilization assay. The strains were subjected to antibiotic susceptibility testing and antimicrobial activity screening. Pseudomonas aeruginosa strain SM-11 was found to produce 4 known antibacterial molecules (pyocyanine, pyochelin, pyoluteorin, monorhamnolipid). Production of pyocyanine was induced by cocultivation with test microorganisms Pseudomonas aeruginosa ATCC 27853 and Escherichia coli ATCC 25922. The results suggest that the mammal microbiota might serve as a valuable source of antimicrobial-producing strains, including those of rare taxa. Cocultivation techniques are promising approach to explore antimicrobials from silent biosynthetic gene clusters.

We report about a series of methylene-imidazolones with complexing groups. The fluorescent properties of these compounds were studied in various solvents as well as in the presence of different salts. We discovered that two of the synthesized substances – hydroxyquinolinidene-imidazolone and difluorobenzimidazolidene-imidazolone – can be used as selective fluorescent sensors for cadmium and zinc ions and potentially as markers for monitoring intracellular processes.