NMR-based identification of cell wall anionic polymers of Spirilliplanes yamanashiensis VKM Ac-1993(T)

Recent progress on fluorous synthesis of biologically interesting compounds

This article highlights research papers published in 2011 and 2012 on fluorous linker-assisted synthesis of biologically interesting small molecules and biomolecules.

Disaccharide 1-phosphate polymers of some representatives of the Bacillus subtilis group

Disaccharide 1-phosphate polymers as well as teichoic acids of various structures have been found in the cell walls of the representatives of the Bacillus subtilis group, namely Bacillus subtilis subsp. spizizenii VKM B-720 and VKM B-916, B. subtilis VKM B-517, and Bacillus vallismortis VKM B-2653(T). Disaccharide 1-phosphate polymers are composed of repeating units of the following structure: -P-4)-β-D-GlcpNAc-(1→6)-α-D-Galp-(1-, the N-acetylglucosamine residues are partially acetylated at positions O3 and O6 (VKM B-720 and VKM B-916); -P-4)-β-D-Glcp-(1→6)-α-D-GlcpNAc-(1-, the glucopyranose residues are partially acetylated at positions O2 or O3 (VKM B-517); -P-6)-α-D-GlcpNH3(+)/α-D-GlcpNAc-(1→2)-α-D-Glcp-(1-, the N-acetylglucosamine residues are partially deacetylated (VKM B-2653(T)). The structures of the two last disaccharide 1-phosphate polymers have not been reported so far for Gram-positive bacteria. The teichoic acids in the studied strains are O-D-alanyl-1,5-poly(ribitol phosphates) substituted with β-D-glucopyranose (VKM B-517, VKM B-720, VKM B-916) or 2-acetamido-2-deoxy-β-D-glucopyranose (VKM B-2653(T)). The structures of the phosphate-containing polymers have been studied by chemical methods and by NMR spectroscopy.

Heterogeneous set of cell wall teichoic acids in strains of Bacillus subtilis VKM B-760 and VKM B-764

Cell walls of Bacillus subtilis VKM B-760 and VKM B-764 are characterized by heterogeneous composition of teichoic acids. Polymer I with structure -6)-beta-D-Galp-(1-->1)-sn-Gro-(3-P-, polymer II with structure -6)-alpha-D-Glcp-(1-->1)-sn-Gro-(3-P-, and a small amount of unsubstituted 1,3-poly(glycerol phosphate) were detected in strain VKM B-760. Strain VKM B-764 contains an analogous set of teichoic acids, but a characteristic feature of polymer II is the presence of disubstituted glycerol residue with alpha-glucopyranose localization in the integral chain at C-1 hydroxyl and beta-glucopyranose as a side branch at C-2 hydroxyl (polymer III): -6)-alpha-D-Glcp-(1-->1)-[beta-D-Glcp-(1-->2)]-sn-Gro-(3-P-. The structures of polymer I in bacilli and polymer III in Gram-positive bacteria are described for the first time. Teichoic acids were studied by chemical methods and on the basis of combined analysis of one-dimensional 1H-, 13C-, and (31)P-NMR spectra, homonuclear two-dimensional (1)H/(1)H COSY, TOCSY, and ROESY, and heteronuclear two-dimensional (1)H/(13)C gHSQC- and HMQC-TOCSY experiments. Simultaneous presence of several different structure teichoic acids in the bacillus cell walls as well as chemotaxonomical perspectives of the application of these polymers as species-specific markers for members of the Bacillus genus is discussed.

Natural phosphoglycans containing glycosyl phosphate units: structural diversity and chemical synthesis

An anomeric phosphodiester linkage formed by a glycosyl phosphate unit and a hydroxyl group of another monosaccharide is found in many glycopolymers of the outer membrane in bacteria (e.g., capsular polysaccharides and lipopolysaccharides), yeasts and protozoa. The polymers (phosphoglycans) composed of glycosyl phosphate (or oligoglycosyl phosphate) repeating units could be chemically classified as poly(glycosyl phosphates). Their importance as immunologically active components of the cell wall and/or capsule of numerous microorganisms upholds the need to develop routes for the chemical preparation of these biopolymers. In this paper, we (1) present a review of the primary structures (known to date) of natural phosphoglycans from various sources, which contain glycosyl phosphate units, and (2) discuss different approaches and recent achievements in the synthesis of glycosyl phosphosaccharides and poly(glycosyl phosphates).

Carbohydrate-containing polymers of the cell wall of the thermophilic streptomycete Streptomyces thermoviolaceus subsp. thermoviolaceus VKM Ac-1857T

Anionic polymers of the cell surface of a thermophilic streptomycete were investigated. The cell wall of Streptomyces thermoviolaceus subsp. thermoviolaceus VKM Ac-1857(T) was found to contain polymers with different structure: teichoic acid--1,3-poly(glycerol phosphate), disaccharide-1-phosphate polymer with repeating unit -6)-alpha-Galp-(1-->6)-alpha-GlcpNAc-P-, and polysaccharide without phosphate with repeating unit -->6)-alpha-GalpNAc-(1-->3)-beta-GalpNAc-(1-->. Disaccharide-1-phosphate and polysaccharide without phosphate have not been described earlier in prokaryotic cell walls.

Anionic Polymers of the Cell Wall of Brevibacterium linens VKM Ac-2159

Unsubstituted 1,3-poly(glycerol phosphate) and two sugar-1-phosphate polymers were identified in the cell wall of Brevibacterium linens VKM Ac-2159 by NMR spectroscopy and chemical methods. A monomer of one of the sugar-1-phosphate polymers has the branched repeating unit of the following structure: -4)-[beta-D-GlcpNAc-(1-->3)]-alpha-D-Glcp-(1-P-. The repeating unit of another sugar-1-phosphate polymer has a linear structure consisting of alternating beta- and alpha-N-acetylglucosamine residues: -4)-beta-D-GlcpNAc-(1-->6)-alpha-D-GlcpNAc-(1-P-. Some part of the beta-N-acetylglucosaminyl residues bear O-ester-bound succinic acid residues at C-3. The identified sugar-1-phosphate polymers have not been described earlier in cell walls of other bacteria.