The coumarin nucleus is a recurring motif in both natural and synthetic compounds that exhibit a broad spectrum of biological properties including anticoagulant, anti-inflammatory, antioxidant, antiviral, antimicrobial and anticancer agents as well as enzyme inhibitors. On the other hand, it has been reported that the incorporation of a metal ion into coumarin derivatives can increase the activity of such complexes compared to coumarin-based ligands. Accordingly, some of them have been found to display promising antioxidant, antitumor or antibacterial activities. This mini-review briefly summarizes the recent development of coumarin-metal complexes with proven biological properties. The attention is also paid to agents for which practical applications in the detection of biologically important species may be found.

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The O-polysaccharide (OPS) was isolated from Cronobacter universalis NCTC 9529 T , a new species in the genus Cronobacter, which was created by the reclassification of the species Enterobacter sakazakii. Purified polysaccharide was analyzed by NMR spectroscopy ( 1 H, COSY, TOCSY, ROESY, HSQC, and HSQC-TOCSY) and chemical methods. The monosaccharide derivatives were analyzed by gas chromatography, and gas chromatographymass spectrometry. These experiments enabled the type and number of monosaccharides in the repeating unit of OPS, their positions of linkages, and absolute configuration to be determined. Together the chemical analysis established a structure of the OPS of C.universalis NCTC 9529 T : Cronobacter is a newly emergent Gram-negative bacterial pathogen associated with severe neonatal infections through the ingestion of contaminated reconstituted infant formula. →3)--L-FucpNAc-(1→4)--D-Manp-(1→3)--L-FucpNAc-(1→3)-β-D-GlcpNAc-(1→Despite the need for improved detection and profiling technologies for the detection and control of the bacterium in powdered infant formula to date the OPS of only a fewCronobacter strains has been determined from the ten recognised species. Lipopolysaccharide Table. 1. The anomeric configurations of sugar residues were assigned (Fig. 2). 13 On the ROESY spectrum inter-residual NOE protons contacts were observed between: A1/B4, B1/C3, C1/D3, D1/A3.The NMR spectroscopy experiments and chemical analysis of O-polysaccharide enabled to establish a structure of the OPS of C. universalis NCTC 9529 T as:In this paper we structurally characterized the OPS isolated from C. universalis for the first The isolation of O-polysaccharideLPS (380 mg) was hydrolyzed with diluted acetic acid (1% CH3COOH, 2h at 100 °C) to cleave lipid A from the sugar portion of LPS. Then the sample was centrifuged to separate the lipid A. The supernatant was evaporated in a vacuum evaporator to remove acetic acid. Then sample was dissolved in distilled water, frozen and lyophilized. The part of lyophilizate (100 mg) was dissolved in distilled water and subjected to size exclusion chromatography (SEC)using Bio-Gel P-100 (Bio-councils; USA). 10 Separation was carried out against deionized water on a column (100 x 0.9 cm). Collected fractions were monitored by a differential refractometer detector (RI-2031 Jasco, Japan). Finally, 3 mg of high molecular weight polysaccharide was obtained for structural analyses. Chemical analysisSugar analysis was performed to determine the sugar composition of O-polysaccharide. The NMR spectroscopyNMR spectra were recorded at 308 K using Bruker Avance III 700 MHz spectrometer. 2 mg of polysaccharide was dissolved in 1 mL of 99% D2O and freeze-dried to replace all exchangeable protons. The process was repeated twice, and the final sample was dissolved in 0.75 mL of 99.9% D2O. Chemical shifts were referenced to acetone (δH 2.225, δC 31.45). All 1D NMR spectra ( 1 H and 13 C) and 2D (COSY, TOCSY, ROESY, HSQC, and HSQC-TOCSY were registered using standard Bruker pulse prog...

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Pectobacterium and Dickeya are gram‐negative phytopathogens representing the Pectobacteriaceae family. Representatives of this genus cause damage to crops worldwide, posing a global threat to agricultural food production. The studies of chemical structures of the bacterial O‐polysaccharide repeating units and the role of these elements in the pathogenesis process are bringing about in‐depth understanding of the complex interactions of pathogenic microbes with plants, leading to potential reduction or elimination of phytopathogens. This review is devoted to structural variation characteristics of the O‐polysaccharides of strains of the Pectobacterium and Dickeya genera, which help with improving classification schemes of these strains. Attention is also paid to the antigenic correlations of these strains within the genus and their O‐polysaccharide‐related bioactivities as well as the possible role of this component in plant–microbe interactions.