Trisaccharide Unit Research Articles

Capsule structure of Proteus mirabilis (ATCC 49565).

Proteus mirabilis 2573 (ATCC 49565) produces an acidic capsular polysaccharide which was shown from glycose analysis, carboxyl reduction, methylation, periodate oxidation, and the application of one dimensional and two-dimensional high-resolution nuclear magnetic resonance techniques to be a high-molecular-weight polymer of branched trisaccharide units composed of 2-acetamido-2-deoxy-D-glucose (N-acetyl-D-glucosamine), 2-acetamido-2,6-dideoxy-L-galactose (N-acetyl-L-fucosamine), and D-glucuronic acid, having the structure: [formula: see text] P. mirabilis 2573 also produces an O:6 serotype lipopolysaccharide in which the O-chain component has the same structure as the homologous capsular polysaccharide. This is the first report of a defined capsular polysaccharide in this bacterial genus.

Convergent synthesis of higher-order oligosaccharides corresponding to the cell-wall polysaccharide of the β-hemolytic streptococci group A. a branched hexasaccharide hapten

A convergent synthesis of a hexasaccharide corresponding to the cell-wall polysaccharide of the β-hemolytic Streptococci Group A is described. The strategy relies on the preparation of a key branched trisaccharide unit α- l-Rha p-(1 → 2)[[β- d-Glc pNAc-(1 → 3)]-α- l-Rha p which functions both as a glycosyl acceptor and donor. The hexasaccharide is obtained after only three glycosylation reactions. This fully functionalized unit can serve, in turn, as a glycosyl acceptor or donor for the synthesis of higher-order structures. Deprotection gives a hexasaccharide for use as a hapten in immunochemical studies. The characterization of all compounds by high resolution 1H- and 13C-n.m.r. spectroscopy is also described.

Structural characterization of the O-polysaccharide of the lipopolysaccharide produced by Salmonella milwaukee O:43 (group U) which possesses human blood group B activity.

The O-polysaccharide of the lipopolysaccharide produced by Salmonella milwaukee O:43 (group U) was shown by composition analysis, methylation, periodate oxidation, and 1H and 13C nuclear magnetic resonance spectroscopic analytical methods to be a polymer of branched pentasaccharide repeating units having the structure: [formula: see text] The blood-group activity of the O-polysaccharide was established by its serological reactivity with a specific monoclonal antibody to human blood group B, using passive hemagglutination and ELISA assays, indicating the common antigenic epitope to be a nonreducing terminal trisaccharide unit composed of L-Fucp and D-Galp (1:2) residues.

Structural studies of the capsular polysaccharide from actinobacillus pleuropneumoniae serotype 12

The capsular polysaccharide of A. pleuropneumoniae is composed of 2-acetamido-2-deoxy- d-glucose (3 parts) and phosphate (1 part). The arrangement of these components in the repeating unit was determined by dephosphorylation, methylation, g.l.c.-m.s., and 1D and 2D n.m.r. spectroscopic methods. The polysaccharide was found to be a high molecular weight polymer of repeating trisaccharide units, joined through phosphate diester linkages, having the structure.

Structure of the type 5 capsular polysaccharide of Staphylococcus aureus

The Staphylococcus aureus type 5 capsular polysaccharide is composed of 2-acetamido-2-deoxy- l-fucose (1 part), 2-acetamido-2-deoxy- d-fucose (1 part), and 2-acetamido-2-deoxy- d-mannuronic acid (1 part). On the basis of methylation analysis, optical rotation, high-field one- and two-dimensional 1H- and 13C-n.m.r. experiments, and selective cleavage with 70% aqueous hydrogen fluoride, the polysaccharide was found to be a partially O-acetylated (50%) polymer of the repeating trisaccharide unit, [→4)-3- O-Ac-β- d-Man pNAcA-(1→4)-α- l-Fuc pNAc-(1→3)-β- d-Fuc pNAc-(1→] n.

Synthesis of α 1→6-Mannooligosaccharides in Mycobacterium Smegmatis: Function of β-Mannosylphosphoryldecaprenol as the Mannosyl Donor

Incubation of a membrane fraction from Mycobacterium smegmatis cells with GDP-mannose and free mannose at pH 7 in presence of Mg2+ ions resulted in the formation of a series of alpha 1----6-linked mannooligosaccharides with up to 12 mannoses. The membrane fraction also catalyzed incorporation of mannose from GDP-mannose into a lipid-soluble product with the properties of a mannosyl phospholipid. A similar product was formed by the incubation of the membrane protein with decaprenol phosphate and GDP-mannose, and it was characterized as beta-mannosylphosphoryldecaprenol. A pulse-chase experiment suggested that the mannosyl phospholipid was an intermediate in alpha 1----6-linked mannooligosaccharide synthesis, and the isolated beta-mannosylphosphoryldecaprenol was shown to function as a direct mannosyl donor on incubation with mannose, methyl alpha-D-mannoside, or alpha 1----6-linked mannooligosaccharides as acceptors. The Km values for mannose, methylmannoside, and alpha 1----6-linked mannobiose were 30-90 mM, whereas for alpha 1----6-linked mannotriose, mannotetraose, and mannopentaose the Km dropped to 2 mM. A weak enzymic activity was detected at pH 6 in the presence of both Mg2+ and Mn2+ ions that catalyzed addition of mannose in alpha 1----2 linkage to the longer alpha 1----6-mannooligosaccharides in a reaction that was specific for GDP-mannose as the donor. The membrane preparation also contained an endo-alpha 1----6-mannanase activity that degraded products longer than mannotriose by cleavage of trisaccharide units from the nonreducing end of the alpha 1----6-mannooligosaccharides.

ChemInform Abstract: Building Units of Oligosaccharides. Part 92. Synthesis of Trisaccharide Units of the Inner Core Region of Lipopolysaccharides.

ChemInform Abstract: Building Units of Oligosaccharides. Part 92. Synthesis of Trisaccharide Units of the Inner Core Region of Lipopolysaccharides.

Partial deletion of the cloned rfb gene of Escherichia coli O9 results in synthesis of a new O-antigenic lipopolysaccharide

The rfb gene, involved in the synthesis of the O-specific polysaccharide (a mannose homopolymer) of Escherichia coli O9 lipopolysaccharide (LPS), was cloned in E. coli K-12 strains. The O9-specific polysaccharide covalently linked to the R core of K-12 was extracted from the K-12 strains harboring the O9 rfb gene. All the other genes required for the synthesis of rfe-dependent LPS are therefore considered to be present in the K-12 strains. It was found that bacteria harboring some clones with deletions of the ca. 20-kilobase-pair (kbp) BglII-StuI fragment no longer synthesized the O9-specific polysaccharide. However, bacteria harboring clones del 21, del 22, and del 25, which carry deletions of the 10-kbp PstI-StuI fragment, synthesized an O-specific polysaccharide antigenically distinct from E. coli O9 LPS. Although this new O-specific polysaccharide consisted solely of mannose and the mannose residues were combined only through alpha-1,2 linkage, it was still composed of a repeating oligosaccharide unit, possibly a trisaccharide unit,----2)alpha Man-(1----2)alpha Man-(1----2)alpha Man-(1----. It is therefore likely that this new O-specific polysaccharide was derived from a part of the O9-specific polysaccharide----3)alpha Man-(1----3)alpha Man-(1----2)alpha Man-(1----2)alpha Man-(1----2)alpha Man-(1----and that the deleted part of the clones was responsible for the synthesis of alpha-1,3 linkages of the O9-specific polysaccharide.

Ontogenetic expression of the murine erythrocyte glycophorins.

The major sialoglycoproteins or glycophorins of the murine erythrocyte membrane, gp2 (Mr 44,000) and gp3 (Mr 29,000), are expressed as identical or closely related antigens by the three erythroid cell lines that succeed each other in normal mouse development. The embryonic forms of gp2 and gp3 differ from the adult forms by their mobility on SDS-PAGE. The apparent Mr values are increased by 1000-2000 for gp2 and 500 for gp3. An increase in the microheterogeneity of both embryonic and fetal forms of gp2 is also detected. Variations in glycosylation account in part for the apparent differences in Mr. Sizing of O-glycosidically linked oligosaccharide chains reveals that fetal glycophorins contain predominantly trisaccharide units while their adult counterparts are mostly tetrasaccharides. The kinetics of gp2 and gp3 biosynthesis in fetal liver are comparable to those established for the splenic erythroblasts of adult anemic mice. Like their adult counterparts, fetal glycophorins incorporate [3H]palmitate and [3H]galactose. The results indicate that, in murine ontogeny, distinct but antigenically related sialoglycoproteins are produced at each erythropoietic stage.

ChemInform Abstract: Protective Group Dependent Stability of Intersaccharide Bonds ‐ Synthesis of a Fucosyl Chitobiose Glycopeptide.

AbstractThe acetyl‐protecting groups in the fucose moiety of the trisaccharide unit Fch stabilize the intersaccharide bonds such that they are not ruptured during the cleavage of the C‐terminal tert.‐butyl protecting group from, e.g., the condensation product of the components (III) and (IV) with TFA.

Synthesis and immunoreactivity of neoglycoproteins containing the trisaccharide unit of phenolic glycolipid I of Mycobacterium leprae

The trisaccharide segment, O-(3,6-di- O-methyl-β- d-glucopyranosyl)-(1→4)- O-(2,3-di- O-methyl-α- l-rhamnopyranosyl)-(1→2)- 3- O-methyl- l-rhamnopyranose, of the Mycobacterium leprae-specific phenolic glycolipid I has been synthesized as its 8-(methoxycarbonyl)octyl glycoside and coupled to a carrier protein, to produce a leprosy-specific neoglycoprotein, the so-called natural trisaccharide-octyl-bovine serum albumin (NT-O-BSA). Special features of the synthetic strategy were the use of silver trifluoromethanesulfonate (triflate) to promote glycosylation, resulting in the rhamnobiose in high yield and absolute stereospecificity. The terminal 3,6-di- O-methyl- d-glucopyranosyl group was introduced after O-deallylation of the rhamnobiose. Removal of protecting groups yielded the trisaccharide hapten suitable for coupling to carrier protein. Poly(acrylamide)-gel electrophoresis of the neoglycoprotein demonstrated its purity, and subsequent immunoblotting with a monoclonal antibody directed to the terminal 3,6-di- O-methyl-β- d-glucopyranosyl epitope of the native glycolipid demonstrated its antigenicity. Comparative serological testing in enzyme-linked immunosorbent assays of NT-O-BSA, the corresponding disaccharide-containing products, and another trisaccharide-containing neoglycoprotein, O-(3,6-di- O-methyl-β- d-glucopyranosyl)-(1→4)- O-(2,3-di- O-methyl-α- l-rhamnopyranosyl)-(1→2)-(3- O- methyl-α- l-rhamnopyranosyl)-(1→4′)-oxy-(3-phenylpropanoyl)-BSA (NT-P-BSA) [Fujiwara et al., Agric. Biol. Chem., 51 (1987) 2539–2547] against sera from leprosy patients and control populations showed concordance; the presence of the innermost sugar did not contribute significantly to sensitivity or specificity. The di- and tri-saccharide-containing neoantigens, on account of ready availability and solubility, provide greater flexibility than the native glycolipid for the serodiagnosis of leprosy.

Structure of the capsular polysaccharide of Haemophilus pleuropneumoniae serotype 3.

The capsular polysaccharide of Haemophilus pleuropneumoniae serotype 3 (ATCC 27090) is composed of D-galactose (one part), 2-acetamido-2-deoxy-D-glucose (one part), glycerol (one part), and phosphate (one part). From hydrolysis, dephosphorylation, methylation, and 1H and 13C nuclear magnetic resonance studies, the polysaccharide was found to be a high molecular weight polymer of a repeating trisaccharide unit, joined through monophosphate diester linkages and having the following structure: (formula; see text).

Chemical synthesis of the trisaccharide unit of the species-specific phenolic glycolipid from Mycobacterium leprae

O-(3,6-di- O-methyl-β- d-glucopyranosyl)-(1→4)- O-(2,3-di- O-methyl-α- l-rhamnopyranosyl)-(1→2)-3- O-methyl- l- rhamnopyranose, the haptenic trisaccharide of the Mycobacterium leprae-specific phenolic glycolipid I (PGL-I) antigen, and related trisaccharides, were synthesized by allylation of O-2 of benzyl 4- O-benzyl-α- l-rhamnopyranoside using phase-transfer catalysis, methylation of the product, deallylation, and coupling to O-(2,4-di- O-acetyl-3,6-di- O-methyl-β- d-glucopyranosyl)-(1→4)-2,3-di- O-methyl- l-rhamnopyranosyl bromide or related disaccharides. Anomeric mixtures of the trisaccharide derivatives were separated by preparative t.l.c., deacetylated, and hydrogenolyzed, to give the pure trisaccharides. It had already been demonstrated that only those trisaccharides containing an intact, terminal 3,6-di- O-methyl-β- d-glucopyranosyl unit are effective in inhibiting the specific binding between PGL-I and unit-PGL-I immunoglobulin M antibodies in human lepromatous leprosy sera.

ChemInform Abstract: Chemical Synthesis of Disaccharides of the Specific Phenolic Glycolipid Antigens from Mycobacterium leprae and of Related Sugars.

Abstract O -(3,6-Di- O -methyl-β- d -glucopyranosyl)-(1→4)-2,3-di- O -methyl- l -rhamnopyranose, which is the nonreducing disaccharide of the haptenic trisaccharide of the Mycobacterium leprae -specific, phenolic glycolipid I, O -(6- O -methyl-β- d -glucopyranosyl)-(1→4)-2,3-di- O -methyl- l -rhamnopyranose, the nonreducing end of the specific, phenolic glycolipid III, and the nonhaptenic O -β-( d -glucopyranosyl)-(1→4)-2,3-di- O -methyl- l -rhamnopyranose, were synthesized in relatively good yield from 3- O -methyl- d -glucose, or d -glucose, and l -rhamnose via Koenigs-Knorr reactions. These disaccharides can be used as precursors in the synthesis of the trisaccharide unit of phenolic glycolipid I and of neoglycoconjugates suitable for the serodiagnosis of leprosy.

Chemical synthesis of disaccharides of the specific phenolic glycolipid antigens from Mycobacterium leprae and of related sugars

O-(3,6-Di- O-methyl-β- d-glucopyranosyl)-(1→4)-2,3-di- O-methyl- l-rhamnopyranose, which is the nonreducing disaccharide of the haptenic trisaccharide of the Mycobacterium leprae-specific, phenolic glycolipid I, O-(6- O-methyl-β- d-glucopyranosyl)-(1→4)-2,3-di- O-methyl- l-rhamnopyranose, the nonreducing end of the specific, phenolic glycolipid III, and the nonhaptenic O-β-( d-glucopyranosyl)-(1→4)-2,3-di- O-methyl- l-rhamnopyranose, were synthesized in relatively good yield from 3- O-methyl- d-glucose, or d-glucose, and l-rhamnose via Koenigs-Knorr reactions. These disaccharides can be used as precursors in the synthesis of the trisaccharide unit of phenolic glycolipid I and of neoglycoconjugates suitable for the serodiagnosis of leprosy.

Anticancer and antimicrobial glycosides from ipomoea bahiensis

Four new antimicrobial glycosides have been isolated from Ipomoea bahiensis. Spectroscopic properties and basic and acidic hydrolysis characterized them as derivatives of 11 -hydroxy hexadecanoic and 11-hydroxy tetradecanoic acid, glycosidically linked in the 11-position to a trisaccharide unit composed of glucose, rhamnose and fucose which is esterified by tiglic and 3-hydroxy-2-methylbutyric acid. One of these compounds revealed significant activity against Sarcoma 180 in mice.

Synthesis of the E-D-C trisaccharide unit of aureolic acid cytostatics

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis of the E-D-C trisaccharide unit of aureolic acid cytostaticsJoachim Thiem and Manfred GerkenCite this: J. Org. Chem. 1985, 50, 7, 954–958Publication Date (Print):April 1, 1985Publication History Published online1 May 2002Published inissue 1 April 1985https://doi.org/10.1021/jo00207a009RIGHTS & PERMISSIONSArticle Views245Altmetric-Citations58LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (736 KB) Get e-Alerts Get e-Alerts

Synthese der tetra- und trisaccharid-sequenzen von asialo-G M1 und -G M2. Lenkung der regioselektivität der glycosidierung von lactose

A regioselective β-glycosidation of lactose derivatives unsubstituted at OH-3′ and -4′ is possible, depending on the catalyst system applied. With silver silicate or silver carbonate as catalyst under heterogeneous conditions, β-glycosidation occurred selectively at the less reactive OH-4′ group of the acceptor, whereas with trimethylsilyl triflate or soluble mercury salt as catalyst under homogeneous conditions, it occurred almost exclusively at the more reactive OH-3′ group. The reactivity of the glycosyl donor, acceptor, and catalyst had to be properly matched for successful regioselective coupling. In this way, the trisaccharide unit of asialo- G M2-ganglioside, O-(2-acetamido-2-deoxy-β- d-galactopyranosyl)-(1→4)-(β- d- galactopyranosyl)-(1→4)- d-glucopyranose, and the tetrasaccharide unit of asialo- G M1-ganglioside, O-(β- d-galactopyranosyl)-(1→3)-(2-acetamido-2-deoxy-β- d-galactopyranosyl)- (1→4)-(β- d-galactopyranosyl)-(1→4)-β- d-glucopyranose were synthesized. This new method constitutes a very useful approach in the field of ganglioside synthesis.

Secondary structure of hyaluronate in solution. A 1H-n.m.r. investigation at 300 and 500 MHz in [2H6]dimethyl sulphoxide solution.

The 1H-n.m.r. spectra of solutions in [2H6]dimethyl sulphoxide of the sodium salts of tetra-, hexa- and octa-saccharides prepared from hyaluronate by testicular-hyaluronidase digestion were examined at 300 and 500 MHz. The signals from hydroxy groups at positions 2 and 3 in the glucuronic acid moiety were assigned. Their chemical shifts and associated temperature-dependencies, as well as their coupling constants, depended on whether or not the uronic acid was at the non-reducing end. Deviations from the 'normal' pattern of hydroxy-group proton n.m.r. behaviour were attributable to participation in hydrogen bonds, either to the acetamido carbonyl oxygen atom or the pyranose ring oxygen atom of neighbouring N-acetylhexosamine moieties. A secondary structure, containing four different hydrogen bonds per trisaccharide unit of glucuronsyl-hexosaminyl-glucuronic acid, was demonstrated. This is the first complete and detailed secondary structure to be established for hyaluronate in any solvent. Hyaluronate is compared with chondroitin sulphate, dermatan sulphate, heparan sulphate and keratan sulphate in their potential to form secondary structures with features in common. The significance of the details of the structure to its overall stability, and the probability of their persistence into aqueous environments, are discussed. The presence of all or most of the secondary structure in glycosaminoglycuronans is correlated with a space-filling function in the tissue, and with a high carbohydrate content in the parent proteoglycan in the case of the chondroitin sulphates.

Novel oligosaccharide chains on polysialoglycoproteins isolated from rainbow trout eggs. A unique carbohydrate sequence with a sialidase-resistant sialyl group, DGa1NAc beta 1 leads to 4(NeuGc2 leads to 3)DGa1NAc.

A series of novel carbohydrate chains all possessing a hitherto unknown trisaccharide unit, Ga1NAc beta 1 leads to 4-(NeuGc2 leads to 3)Ga1NAc beta 1 leads to, have been isolated from trout egg polysialoglycoproteins, a new class of glycoproteins, on alkali-borohydride treatment. On the basis of chemical (methylation, Smith degradation, and hydrazinolysis-nitrous deamination) and direct-probe mass spectrometric methods. deamination) and direct-probe mass spectrometric methods, the structures of a series of the first major type of oligosaccharide alditols having a sialidase-resistant N-glycolyneuraminic acid residue in each molecule were determined. The structures thus determined are novel and all possess a unique carbohydrate sequence (sialidase-resistant unsubstituted sialyl group italicized): Ga1NAc beta 1 leads to 4(NeuGc2 leads to 3)Ga1NAc beta 1 leads to 3Gal beta 1 leads to-4Gal beta 1 leads to 3[(leads to 8NeuGc alpha 2)n leads to 6]Ga1NAcol (n = 0 through 3).