Structures of two putative O-specific polysaccharides from the Rahnella aquatilis 3-95 lipopolysaccharide

Structure of the Cell-Wall-Associated Polysaccharides from the Deep-Sea Marine Bacterium Devosia submarina KMM 9415T

Two cell-wall-associated polysaccharides were isolated and purified from the deep-sea marine bacterium Devosia submarina KMM 9415^T, purified by ultracentrifugation and enzymatic treatment, separated by chromatographic techniques, and studied by sugar analyses and NMR spectroscopy. The first polysaccharide with a molecular weight of about 20.7 kDa was found to contain d-arabinose, and the following structure of its disaccharide repeating unit was established: →2)-α-d-Araf-(1→5)-α-d-Araf-(1→. The second polysaccharide was shown to consist of d-galactose and a rare component of bacterial glycans-d-xylulose: →3)-α-d-Galp-(1→3)-β-d-Xluf-(1→.

Structure of cell-wall glycopolymers of Micrococcus luteus C01

Glycopolymers of two types were isolated from the cell wall of Micrococcus luteus C01 by stepwise extraction with cold and hot 10% aq CCl₃CO₂H. The following structures of the glycopolymers were established by compositional analysis and 1D and 2D NMR spectroscopy: where L-Glu indicates glutamic acid.

A review of NMR analysis in polysaccharide structure and conformation: Progress, challenge and perspective

Nuclear magnetic resonance (NMR) has been widely used as an analytical chemistry technique to investigate the molecular structure and conformation of polysaccharides. Combined with 1D spectra, chemical shifts and coupling constants in both homo- and heteronuclear 2D NMR spectra are able to infer the linkage and sequence of sugar residues. Besides, NMR has also been applied in conformation, quantitative analysis, cell wall in situ, degradation, polysaccharide mixture interaction analysis, as well as carbohydrates impurities profiling. This review summarizes the principle and development of NMR in polysaccharides analysis, and provides NMR spectra data collections of some common polysaccharides. It will help to promote the application of NMR in complex polysaccharides of biochemical interest, and provide valuable information on commercial polysaccharide products.

Abundance of Plant-Associated Gammaproteobacteria Correlates with Immunostimulatory Activity of Angelica sinensis

Background:Angelica sinensis is a medicinal plant known for a variety of biological effects, including its ability to stimulate innate immune cells in humans. Recent studies indicate that the immunostimulatory activity of A. sinensis arises from microbe-associated molecular patterns (MAMPs) of plant-associated bacteria. However, it is unknown which bacterial taxa in A. sinensis are responsible for the production of immunostimulatory MAMPs. Methods: Samples of A. sinensis were subjected to a cell-based assay to detect monocyte-stimulation and 16S ribosomal RNA amplicon sequencing, which revealed their immunostimulatory activity and microbial communities. The resulting data were analyzed by Linear discriminant analysis effect size (LEfSe), an online biostatistical tool for metagenomic biomarker discovery, to identify the bacterial taxonomical features correlated with the immunostimulatory activity. Results: A series of bacterial taxa under Gammaproteobacteria correlated positively with the immunostimulatory activity, whereas several Gram-positive taxa and Betaproteobacteria correlated negatively with the activity. Conclusions: The identified bacterial taxa set a new stage to characterize immunostimulatory MAMPs in plants.

Structure of polysaccharide moiety of Pseudomonas xanthomarina KMM 1447T lipopolysaccharide

The structural analysis of a polysaccharide moiety of Pseudomonas xanthomarina KMM 1447^T lipopolysaccharide (LPS) was carried out. Mild acid degradation of LPS resulted in identification of two polysaccharides. The major one was built of β-D-GlcpNAcA residues amidated with L-Ala and Gly residues randomly. The minor polysaccharide was composed of branched tetrasaccharide repeating units constituted by two D-Galр, D-GalpNAc and ether of D-Glc with (2R,4R)-2,4-dihydroxypentanoic acid lactone (2R,4R-Dhpl): →3)-α-D-Galр-(1 → 3)-β-D-Galр-(1 → 3)-[β-D-Glcp4(2R,4R-Dhpl)-(1 → 4)]-β-D-GalpNAc-(1 → .