Rhamnose lipopolysaccharide

Hickman, J., Ashwell, G. Isolation of a bacterial lipopolysaccharide from Xanthomonas campestris containing 3-acetamido-3,6-dideoxy-D-galactose and D-rhamnose. J Biol Chem 241 (1966) 1424-1428. 

Jack bean a-mannosidase has also been able to catalyze the transglycosylation of rhamnose residue. It has been used in the synthesis of a disaccharide Rhaal,2RhaaSEt in 32.1% yield from RhaapNP and ethyl 1-thio-a-D-rhamnopyranoside. The disaccharide product is a derivative of the common oligosaccharide unit of antigenic lipopolysaccharides from Pseudomonas (33). 

J. J. Zhang and F. Kong, Synthesis of a xylosylated rhamnose pentasaccharide-the repeating unit of the O-specific side chain of lipopolysaccharides from the reference strains for Stenotrophomonas mal-tophilia serogroup 018,/. Carbohydr. Chem., 21 (2002) 89-97. 

These two deoxy sugars are the rare monosaccharides that are in the u-configuration. u-Rhamnose is a constituent of lipopolysaccharides of the outer membrane layer of gram-negative bacteria. L-Fucose is a constituent of glycoproteins in cell membranes. 

In bacteria, L-rhamnose may be found linked a and (3 in the same oligosaccharide chain, for instance in the capsular polysaccharide of Streptococcus pneumoniae229 and in the secreted polysaccharide of S. thermophilus.230 In Gram-negative bacteria, L-rhamnose is present in the O-antigen of lipopolysaccharides some recent examples are cited.231 A rhamnan and fucorhamnan are present in the lipopolysaccharide of Burkholderia vietnamiensis "... 

S. N. Senchenkova, A. S. Shashkov, Y. A. Knirel, J. J. McGovern, and A. P. Moran, The O-specific polysaccharide chain of Campylobacter fetus serotype E lipopolysaccharide is a D-rhamnan terminated with 3-O-methyl-D-rhamnose (D-acofriose), Eur. J. Biochem., 239 (1996) 434-438. 

The alginate pathway and the activities of the alginate enzymes overlap with a few other metabolic endpoints. The committed step in alginate biosynthesis is the formation of GDP-mannuronate. GDP-mannose is the precursor of GDP-rhamnose, a constituent of the A-band in lipopolysaccharide (EPS). The GDP-mannose that is required for A-band EPS biosynthesis is formed by the action of phosphomannose isomerase (PMI)/GDP-mannose pyrophosphorylase (GMP) activities that are separate from those used in... 

A sugar component isolated from the lipopolysaccharide from Rh. capsulata was shown by m.s. (as its alditol acetate) to be a 6-deoxy-3-O-methylhexose. From its chromatographic mobilities and optical rotation, it was shown to be identical with 3-O-methyl-L-rhamnose (l-acofriose)... 

The polysaccharide chain of the cell wall lipopolysaccharide of Escherichia coli 058 contains D-mannose, 2-acetamido-2-deoxy-D-mannose, 3-0-[(l R)-carboxyethyl)]-L-rhamnose (rhamnolytic acid), and 0-acetyl groups in the molar ratios of 2 1 1 . Structural investigations show that this polysaccharide, which contains a substituted trisaccharide repeating unit, has an identical structure (4) to that of Shigella dysenteriae type 5. 

The polysaccharide moiety of the lipopolysaccharide of Schizothrix calcicola contains 2-amino-2-deoxy-D-glucose, D-galactose, D-glucose, D-mannose, D-xylose, and L-rhamnose. In contrast to many enterobacterial lipopoly-saccharides, the major fatty acid component has been identified as 3-hydroxy-palmitic acid and not 3-hydroxymyristic acid. 

Figure 2.9 Generalized structures of lipopolysaccharide and lipid A. Abbreviations Abe, abequose Man, Mannose Rha, rhamnose Gal, galactose Glc, glucose Hep, heptose KDO, 3-deoxy-D-manno-octulosonic acid 0, phosphate EtN, ethanolamine M, myristate Mo, y3-hydroxymyristate. Reproduced with permission from Harwood and Russell (1984).

Bacterial cell wall lipopolysaccharides of Salmonella are some of the most interesting examples of the coordinated use of sugar nucleotides involving both different sugars and different nucleotide bases. To a backbone of hexose, phosphate, and ketodeoxyoctanoate, are added in a sequential manner the sugars galactose, abequose, rhamnose, mannose, and A-acetyl-... 

The following 0-methylaldoses have been isolated from, or identified as constituents of, natural products 3-0-methylxylose (in the extracellular mucilage from the red alga Rhodella maculata), 3-0-methyl-L-xylose (together with L-xylose and L-rhamnose from the lipopolysaccharide of Pseudomonas maltophilia), 3-0-methy]-D-ribose (from the extracellular polysaccharide of a Cowpea strain of slow-growing Rhizobium, strain CB 756), 2-0-methyl- and 2,4-di-O-methyl-L-rhamnose (in the antibiotics steffimycin and steffimycin B produced by Strepto-myces steffisburgensis), and 3-0-methyl-galactose and -mannose (from the haemocyanin of snails). ... 

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