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Of tyvelose

The enantiomorph of tyvelose is ascarylose, found not only in certain bacterial antigens but also in the eggs of Ascaris. [Pg.180]

With the dibenzylidene acetal 124a, a twofold reaction with N-bromosuccinimide is possible. Thus, compound 124a reacts with two molecular proportions of N-bromosuccinimide to form the dibromide 124b, which, on hydrogenation, yields 124c, a derivative of tyvelose. [Pg.166]

Fig. 6.2. Caco-2 epithelial cell monolayers cultured with T. spiralis L1 larvae in (A) the absence or (B) presence of 1 mg ml 1 rat monoclonal, tyvelose-specific antibody 9D4 (McVay etal., 2000). Monolayers were fixed and stained with trypan blue as described in ManWarren etal. (1997). (A) Serpentine trails of nuclei in dead cells are evident, revealing the paths travelled by larvae. (B) Tyvelose-specific antibody has inhibited the migration of the larva such that it is encumbered in cell debris and has pulled up a large area of the monolayer, creating a plaque (P). Bar = 50 urn. Photomicrograph prepared by C. McVay, TTUHSC, Lubbock, Texas. [Pg.118]

McVay, C.S., Bracken, P., Gagliardo, L.F. and Appleton, J.A (2000) Antibodies to tyvelose exhibit multiple modes of interference with the epithelial niche of TrichineUa spiralis. Infection and Immunity 68, 1912-1918. [Pg.127]

Reason, A.J., Ellis, L.A., Appleton, J.A., Wisnewski, N., Grieve, R.B., McNeil, M., Wassom, D.L., Morris, H.R. and Dell, A. (1994) Novel tyvelose-containing tri- and tetra-antennary N-glycans in the immunodominant antigens of the intracellular parasite TrichineUa spiralis. Glycobiology 4, 593-603. [Pg.127]

It is important to emphasize that detection of NA has depended on antibody determinants shared by other parasite products, such as the tyvelose containing glycan. The earliest detection of NA is about 9 dpi (Despommier et al., 1990) and persists throughout the chronic infection. Therefore, current evidence supports a potential role for NA only after cell cycle repositioning. [Pg.138]

Fig. 15.5. Structures of A/-linked glycans from several different species of parasitic nematodes, illustrating both similarities with mammalian glycans (compare with Figs 15.1 and 15.2) and features unique to nematodes (e.g. tyvelose and PC capping and novel core fucosylation). The filarial nematode glycans are believed to be substituted with charged residues, which are not yet characterized. Fig. 15.5. Structures of A/-linked glycans from several different species of parasitic nematodes, illustrating both similarities with mammalian glycans (compare with Figs 15.1 and 15.2) and features unique to nematodes (e.g. tyvelose and PC capping and novel core fucosylation). The filarial nematode glycans are believed to be substituted with charged residues, which are not yet characterized.
M. A. Probert, J. Zhang, and D. R. Bundle, Synthesis of a- and /blinked tyvelose epitopes of the Trichinella spiralis glycan 2-Acetamido-2-deoxy-3-0-(3, 6-dideoxy-D-arabmo-hexopyninosyl)-/)-D-galactopyranosides. Carbohydr. Res., 296 (1996) 149-170. [Pg.89]

The derivative (9) of 3,6-dideoxy-a-D-xyIo-hexopyranose (abequose) was isolated from a strain of Salmonella typhimurium,16 that (10) of 3,6-dideoxy-a-D-nfco-hexopyranose (paratose) from Salmonella paratyphi,54 and a mixture of 10 and the ester (11) of 3,6-dideoxy-a-D-arabino-hexopyranose (tyvelose) from Salmonella enteritidis.,6 It was shown that these derivatives are formed from cytidine 5 -(a-D-glu-copyranosyl pyrophosphate) by treatment with nicotinamide adenine dinucleotide (NAD+) and reduced nicotinamide adenine dinucleotide phosphate (NADPH) in the presence of cell extracts of the respective bacterial strain. For example, formation of 9 is characteristic of preparations from Salmonella, group B,55,56 or Pasteurella pseudotuberculosis, type II.56 The derivative 10 was obtained with extracts of Salmonella, group A,56 and Pasteurella pseudotuberculosis, type I and III,56 and a mixture of 10 and 11 with those of Salmonella, group D,55-60 or Pasteurella pseudotuberculosis, type IV 56.59,60 Under similar conditions, the ester (12) of cytidine 5 -pyro-... [Pg.316]

E. H. Williams, W. A. Szarek, and J. K. N. Jones, Synthesis of paratose (3,6-dideoxy-D-rifw-hexose) and tyvelose (3,6-dideoxy-D-orahmo-hexose), Can. J. Chem. 49 796 (1971). [Pg.126]

C. Fouquey, J. Polonsky, and E. Lederer, Synthesis of three 3,6-dideoxyhexoses. Determination of the structure of the natural sugars tyvelose, ascarylose, and paratose, Bull. Soc. Chim. Fr. p. 803 (1959). [Pg.126]

A similar reaction sequence without the last epimerization would yield D-abequose. CDP-D-tyvelose arises by C-2 epimerization of CDP-D-paratose.65a Other unusual sugars66-68 are formed from intermediates in Eq. 20-11. One is a 3-amino-3,4,6-trideoxyhexose in which the amino group has been provided by transamination67 (see also Box 20-B). [Pg.1138]

CDP-6-deoxy-D-xy/o-hexos-4-ulose (7b) serves as a precursor in the biosynthesis of CDP-3,6-dideoxyhexoses28,168 having the d-ribo (paratose, 3,6-dideoxy- D-glucose ), o-xylo (abequose, 3,6-dideoxy- D-galactose ), and d-arabino (tyvelose, 3,6-dideoxy- D-mannose ) configurations. These monosaccharides are characteristic components of O-specific polysaccharides from Salmonella and Yersinia pseudotuberculosis. [Pg.292]

The conversion includes at least three enzymic reactions.169-171 In the first stage, which requires pyridoxamine 5 -phosphate as a cofactor,171,172 dehydration of 7b occurs through intermediate formation of the Schiff base.173 Reduction of the resulting, unsaturated derivative with NADPH, the mechanism of which is not completely clear,174 leads to CDP-3,6-dideoxy-D-eryf/iro-hexos-4-ulose,169 and, in the third stage, further reduction of the latter at C-4 of the hexosyl group produces the derivatives of paratose or abequose the stereochemistry of the reaction is determined by the source of the enzyme.168 The tyvelose derivative is formed as a result of enzymic epimerization at C-2 of the hexosyl group in CDP-paratose.175... [Pg.292]

Dideoxyhexoses. Several bacterial antigenic determinants with the general structure of 3,6-dideoxyhexoses occur in the cell wall of Pasteurella and Salmonella strains. Most of the transformations reported so far occur as cytidine nucleotides (see Table I, References 15, 16, 17, 18, 19). Here, again the first step is the transformation of the cytidine diphospho-linked glucose into its corresponding 4-keto derivative. By at least two distinct steps, requiring NADPH, reduction to several different 3,6-dideoxyhexoses have been reported. One 3,6-dideoxyhexose CDP-tyvelose (3,6-dideoxy-D-arabino hexose) is formed by a specific 2-epimer-ase from CDP-paratose (24). [Pg.397]

G., Garegg, P.J., Svensson, S., and Wallin, N.-H. (1979). Immuno-chemistry of Salmonella O-antigens. Specificity and cross-reactivity of factor 09 serum and of antibodies against tyvelose a-(l—3)-mannose coupled to bovine serum albumin. Int. Archs Allergy appl. Immun. 58, 11-19... [Pg.18]


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See also in sourсe #XX -- [ Pg.282 ]




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