SEARCH · PubMed Health

Results for “HEPTOSES”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 487 records · Page 27Linked to original sources

PubMed1978

Isolation and characterization of the lipopolysaccharide of Thiocapsa roseopersicina.

The lipopolysaccharide from Thiocapsa roseopersicina was isolated by phenol/water, being found in the water phase. It is cleaved into a polysaccharide moiety (degraded polysaccharide) and lipid A by hydrolysis with 10% acetic acid (100 degree C, 3 h). D-Mannose, L-rhamnose, 3-amino-3, 6-dideoxy-D-galactose and D-glucose are the major constituents of the degraded polysaccharide. 2-O-Methyl-L-rhamnose, 3-O-methyl-D-mannose, D-galactose, glucosamine and quinovosamine are minor constituents. D-Glycer-D-manno-heptose (tentatively identified) and 3-deoxy-D-manno-octulosonic acid were detected in only small amounts. Conspicuously, lipid A from T. roseopersicina contains a neutral sugar, D-mannose, in addition to D-glucosamine, as had been observed with lipid A from Chromatium vinosum D. Major fatty acids are beta-hydroxymyristic and lauric acids. Only trace amounts of phosphorus were found indicating this lipid A to be free of phosphate. The lipopolysaccharide of T. roseopersicina represents the O-antigen of the strain. It reacts with antisera prepared against living or heat-killed cells in passive hemagglutination.

Carbohydrates↗

PubMed1978

N-Acetylneuraminic acid: a constituent of the lipopolysaccharide of Salmonella toucra.

The composition of lipopolysaccharide and polysaccharides isolated after acidic or alkaline degradation of lipopolysaccharide of Salmonella toucra has been investigated. The following analytical methods were used in this study: gel-filtration and ion-exchange techniques, paper and gas-liquid chromatography as well as spectrophotometric analysis. The products of the lipopolysaccharide degradation were fractionated on the Sephadex G-25 and Sephadex G-50 columns. Lipopolysaccharide and products of its degradation besides glucosamine, galactose, glucose, heptose(s) and 3-deoxy-D-manno-octulosonate described as 'basal' sugars, also contained N-acetylneuraminic acid and an unidentified amino sugar.

Carbohydrates↗

PubMed1980

Structural studies on the O-specific polysaccharide side-chains of Yersinia pseudotuberculosis, type III, lipopolysaccharides.

Lipopolysaccharide from pathogenic Yersinia pseudotuberculosis type III, strain 209, has been isolated and characterized. Lipopolysaccharide was shown to contain lipid A (30%), protein (4.4%), 2-keto-3-deoxyoctonate (7.8%) and a polysaccharide component (45%), which consisted of paratose, L-fucose, D-mannose, D-glucose, D-galactose (trace), L- and D-glycero-D-manno-heptose, 2-deoxy-2-amino-D-glucose and 2-deoxy-2-amino-D-galactose residues. Molecular -sieve chromatography on Sephadex G-50 afforded on O-specific polysaccharide, being hydrolysed to yield equimolar amounts of paratose, L-fucose, D-mannose and 2-deoxy-2-amino-D-galactose. The chemical repeating unit of the O-specific polysaccharide has been suggested on the basis of methylation studies and periodate oxidation data.

ABO Blood-Group System↗

PubMed1980

Structural studies on Shigella flexneri serotype 6 core region.

The core structure of Shigella flexneri serotype 6 has been investigated. The methods used in these studies involved methylation analysis, periodate oxidation, Smith degradation and enzymic modifications of core oligosaccharides isolated from two smooth strains and four rough mutants. As a result the complete core region was established (Formula: see text) where DGalp = D-galactopyranose, DGlcp = D-glucopyranose, L alpha DHepp = L-glycero-D-mannoheptapyranose, dOclA = 3-deoxy-D-manno-octulosonic, DGlcNp = 2-amino-2-deoxy-D-glucopyranose and P--PEtN = pyrophosphorylethanolamine (partially substituted). In the R mutants examined two types of mutation have been observed: (1) defect in heptose region (lack of D-glucosamine) or (2) defects in hexose region of the core.

Carbohydrate Sequence↗

PubMed1981

Structural studies on the hexose region of the core in lipopolysaccharides from Enterobacteriaceae.

The structures for the hexose regions of cores from Enterobacteriaceae lipopolysaccharides have been investigated, using specific degradations and 1H NMR studies as the principal methods. Complete structures for these regions in the Salmonella, the Escherichia coli R1, R2, R3, R4, the E. coli K12 and E. coli B cores are proposed. Some complementary information on the structure of the heptose region has also been obtained.

Carbohydrate Conformation↗

PubMed1983

The lipopolysaccharide from Pseudomonas aeruginosa NCTC 8505. Structure of the O-specific polysaccharide.

Structural studies have been carried out on the O-specific fraction from the lipopolysaccharide of Pseudomonas aeruginosa NCTC 8505, Habs serotype 03. The O-specific polysaccharide has a tetrasaccharide repeating-unit containing residues of L-rhamnose (Rha), 2-acetamido-2-deoxy-D-glucose (GlcNAc), 2-acetamido-2-deoxy-L-galacturonic acid (GalNAcA), and 2,4-diacetamido-2,4,6-trideoxy-D-glucose (BacNAc2). The following structure has been assigned to the repeating-unit: leads to 3)Rhap(beta 1 leads to 6)GlcpNAc(alpha 1 leads to 4)GalpNAcA(alpha 1 leads to 3)BacpNAc2(alpha 1 leads to. The parent lipopolysaccharide is a mixture of S, R, and SR species, and its high phosphorus content is partly due to the presence of triphosphate residues, as found for other lipopolysaccharides from P. aeruginosa. In addition to phosphorus, heptose, a 3-deoxyoctulosonic acid, and amide-bound alanine, the core oligosaccharide contains glucose, rhamnose, and galactosamine (molar proportions 3:1:1). The rhamnose and part of the glucose are present as unsubstituted pyranoside residues: other glucose residues are 6-substituted.

Carbohydrate Sequence↗

PubMed1983

The lipopolysaccharide of a chloridazon-degrading bacterium.

Lipopolysaccharide of a chloridazon-degrading bacterium was obtained by a two-stage extraction procedure with phenol/EDTA in a yield of 0.3% of dried bacteria. The carbohydrate moiety consisted of heptose, 3-deoxyoctulosonic acid and D-glucose in a molar ratio of 1:2:2 X 3. Lipid A was composed of 1 mol 2,3-diamino-2,3-dideoxy-D-glucose, 2 mol amide-bound and 2.6 mol ester-bound fatty acids/mol. Amide-bound fatty acids were 3-hydroxydodecanoic acid and 3-hydroxyhexadecanoic acid; dodecanoic acid and R-(-)-3-hydroxydodec-5-cis-enoic acid were found to be present in ester linkage. Under conditions of acidic hydrolysis, the latter was converted into the cis and trans isomers of 5-hexyltetrahydrofuran-2-acetic acid. Dodecanoic acid was demonstrated to be linked with the hydroxy groups of the amide-bound fatty acids. The taxonomic significance of these results, especially the demonstration of 2,3-diamino-2, 3-dideoxy-D-glucose, is discussed.

Bacteria↗

PubMed1983

Lipopolysaccharides of the cyanobacterium Microcystis aeruginosa.

Lipopolysaccharides (LPS) of two isolates of Microcystis aeruginosa were extracted with phenol/water and purified. Cesium chloride gradient ultracentrifugation of these preparations yielded only one fraction. The LPS contained significant amounts of 3-deoxy-D-manno-octulosonic acid, glucose, 3-deoxy sugars, glucosamine, fatty acids, fatty acid esters, hexoses, and phosphate. Heptose, a characteristic sugar component of the polysaccharide moiety of LPS of most gram-negative bacteria was absent. Lipopolysaccharides and lipid A hydrolysate of LPS preparations were active in mouse lethality and Limulus lysate gelation. The lipid A moiety was slightly less active in toxicity and Limulus lysate gelation assays than the intact LPS. The LPS and lipid A moiety of the two isolates of M. aeruginosa were less active in toxicity in mice and Limulus test than LPS of Salmonella abortus equi.

Animals↗

PubMed1985

Alterations in rats in vivo of the chemical structure of lipopolysaccharide from Salmonella abortus equi.

A biosynthetically double-labelled lipopolysaccharide (LPS) from Salmonella abortus equi was used to study possible in vivo degradation of LPS in rats. The preparation designated rLPS-I was labelled with 3H in the fatty acids and 14C in the sugars. Three days after its intravenous injection the concentration of the two isotopes in the liver was analysed directly by combustion of liver tissue in a sample oxidizer. It was found that compared to the starting LPS, less 3H activity was present than 14C, indicating that partial deacylation had occurred. Reisolation and purification of radioactive material present in the liver revealed that all radioactivity was present in a macromolecular form. Analysis showed that the ratio of the two isotopes was identical to that determined in the starting liver tissue. To exclude the possibility that the loss of 3H might have been due to isotopic dilution the above experiments were repeated with a second LPS preparation (rLPS-II) labelled with 14C in the fatty acids and 3H in glucosamine. Isotopic analysis confirmed that here too a lower content of fatty acids in the LPS was present in the liver. A large-scale (20 rats) reisolation of non-radioactive LPS of S. abortus equi from rat livers three days after injection was carried out. Chemical analysis revealed the presence of 3-deoxy-D-manno-octulosonic acid, heptose, galactose, mannose and rhamnose in a molar ratio similar to that of the original LPS. However a significant reduction in the amount of abequose was found. Fatty acid analysis showed a significant reduction in the content of 3-hydroxytetradecanoic, dodecanoic and hexadecanoic acids, while 2-hydroxytetradecanoic acid was virtually absent. Only the relative amount of tetradecanoic acid was comparable to that of the starting LPS. Biological activity tests on the reisolated material showed a reduced antigenic activity. However, pyrogenicity, lethal toxicity, local Shwartzman-inducing properties and Limulus lysate gelating activity were comparable to the starting S. abortus equi LPS.

Animals↗

PubMed1986

Structural studies on O-specific polysaccharides of lipopolysaccharides from Yersinia enterocolitica serovars O:5 and O:5,27.

Lipopolysaccharides of Yersinia enterocolitica serovars O:5 and O:5,27 were shown to have a similar sugar composition, consisting of L-rhamnose, D-glucose, D-galactose, D- and L-glycero-D-manno-heptose, 2-acetamido-2-deoxy-D-glucose, 2-acetamido-2-deoxy-D-galactose, 3-deoxy-D-manno-octulosonate and D-threo-pent-2-ulose (D-xylulose). Partial hydrolysis of lipopolysaccharides with acetic acid produced rhamnans with the following repeating unit: ----3)-L-Rha rho(alpha 1----3)-L-Rha rho(alpha 1----3)-L-Rha rho(beta 1----. 13C-NMR and methylation studies of the lipopolysaccharides gave the following structure for the repeating unit of the two O-specific polysaccharides: ----3)-L-Rha rho(alpha 1----3)-L-Rha rho(alpha 1----3)-L-Rha rho(beta 1----. (formula; see text)

Antigens, Bacterial↗

PubMed1986

Core region of Citrobacter lipopolysaccharide from strain PCM 1487. Structure elucidation by two-dimensional 1H-NMR spectroscopy at 500 MHz and methylation analysis/mass spectrometry.

The core structure of Citrobacter PCM 1487 lipopolysaccharide has been established using methylation analysis/mass spectrometry, chemical degradations and one- and two-dimensional 1H-NMR spectroscopy at 500 MHz. 1H-NMR assignments are given for all sugar components of the core oligosaccharide. In the formula shown below, the alternative locations of branch terminal heptose (LDHep) and diphosphorylethanolamine (PPEtN) residues are marked by dashed lines; dOclA stands for 3-deoxy-D-manno-octulosonic acid. (Formula: see text). The sample of the core oligosaccharide showed some microheterogeneity due to a slightly incomplete substitution by terminal N-acetylgalactosamine and a partial splitting of diphosphorylethanolamine residues.

Chemical Phenomena↗

PubMed1989

The core region of Proteus mirabilis R110/1959 lipopolysaccharide.

The complete core structure present in the lipopolysaccharide of the R mutant R110/1959 from Proteus mirabilis (Proteus type II core) was investigated using methylation analysis and a number of degradation methods such as Smith degradation and beta-elimination. These studies combined with earlier work on a Rc-type mutant of P. mirabilis O28 (R4/O28) which shares the same inner core region, allowed formulation of the complete core structure of the Proteus type II core as shown in Scheme 1. (formula; see text) A characteristic feature of the Proteus core of type II is the presence of two units of D-galacturonic acid (DGalA); one in terminal, the other one in a chain-linked position. In addition, the presence of the two isomers of glycero-D-manno-heptose (LDHep and DDHep) and the lack of galactose are conspicuous. DDHep occupies a terminal position in the external core region, whereas the three units of LDHep in addition to dOclA form, as in other enterobacterial core types, the internal core region. The taxonomic significance of the presence of DGalA in the Proteus type II core, but also in all R cores of other Proteeae investigated so far, will be discussed.

Carbohydrate Conformation↗

PubMed1992

Structural investigation on the lipopolysaccharide of Escherichia coli rough mutant F653 representing the R3 core type.

The chemical structure of the core oligosaccharide of the lipopolysaccharide isolated from Escherichia coli rough mutant strain F653, representing the enterobacterial R3 core type, was investigated by quantitative and methylation analyses, nuclear magnetic resonance spectroscopy, gas-liquid chromatography/mass spectrometry, and determined as [formula: see text] All sugars are present as alpha-pyranosides but the anomeric configurations of the 3-deoxy-D-manno-octulopyranosonic acid (Kdo) residues could not be determined. The third Kdo and the heptose-linked GlcN residue are present in nonstoichiometric amounts; the GlcN residues may be, at least partially, N-acetylated.

Acetylation↗

PubMed1993

The structure of the carbohydrate backbone of the core-lipid-A region of the lipopolysaccharide from Vibrio cholerae strain H11 (non-O1).

Lipopolysaccharide from Vibrio cholerae strain H11 (non-O1) was de-O-acylated, dephosphorylated, reduced, de-N-acylated, N-acetylated, and the products were separated by high-performance anion-exchange chromatography (HPAE). A decasaccharide, 1, was isolated as the major product, representing the core oligosaccharide attached to the reduced GlcN-disaccharide lipid A backbone. Its structure was established by compositional and methylation analyses, and extensive NMR investigations including 1H,1H correlation spectroscopy (COSY), total correlation spectroscopy (TOCSY), and nuclear Overhauser enhancement spectroscopy (NOESY), as well as heteronuclear 13C,1H COSY. In another reaction sequence the lipopolysaccharide was hydrolysed with dilute acetic acid and reduced with NaBH4. The resulting core fractions were separated by HPAE giving seven individual octasaccharides differing at the reducing 3-deoxy-D-manno-octulosonic acid (Kdo) residue. A major product, 2, was isolated and investigated by the same methods as described for the decasaccharide 1. The following structures are proposed for compounds 1 and 2: alpha-D-GlcNAcp-(1-7)-[beta-D-Galp-(1-3)-]-alpha-Hepp-(1-2)- alpha-Hepp- (1-3)-[beta-D-Glcp-(1-4)-]- [alpha-D-Glcp-(1-6)-]-alpha-Hepp-(1-5)-R, where R is alpha-Kdop-(2-6)-beta-D-GlcNAcp-(1-6)-D-GlcNAcol in 1 and 4,8-anhydro-Kdool in 2, and Hep is L-glycero-D-manno-heptose. In lipopolysaccharide, the terminal residue of alpha-D-glucosamine possessed a free amino group, as proved by deamination with nitrous acid and the 1H-NMR spectrum of de-O-acylated lipopolysaccharide. The conformational preferences of the terminal core heptasaccharide was assessed by Monte Carlo simulations combined with restrained calculations of side chains based on experimentally determined proton-coupling constants. These calculations, confirmed by NOE data, displayed several long-range interactions, which resulted in a well-defined three-dimensional structure of the core oligosaccharide.

Carbohydrate Conformation↗

PubMed1994

Isolation and structural analysis of oligosaccharide phosphates containing the complete carbohydrate chain of the lipopolysaccharide from Vibrio cholerae strain H11 (non-O1).

For the first time, an oligosaccharide has been prepared comprising the lipid A backbone, the core oligosaccharide and one repeating unit of the O-specific polysaccharide (O-chain) of a lipopolysaccharide. Lipopolysaccharide from Vibrio cholerae strain H11 (non-O1) was deacylated and the products were separated by high-performance anion-exchange chromatography. Major fractions were a hexadecasaccharide trisphosphate 1, representing the core-lipid A oligosaccharide substituted by one modified repeating unit of the O-antigenic polysaccharide, a dodecasaccharide trisphosphate 2 and an undecasaccharide trisphosphate 3, representing the core-lipid A region. Oligosaccharide 1 originated from beta-elimination upon alkaline hydrolysis of alpha-galacturonic acid of the O-chain; oligosaccharides 2 and 3 were most likely obtained from naturally occurring lipopolysaccharide species carrying no O-chain. The structures of these compounds were elucidated on the basis of monosaccharide composition, and NMR investigations comprising correlation spectroscopy, total correlation spectroscopy and nuclear Overhauser enhancement spectroscopy experiments, as well as heteronuclear 13C, 1H correlation spectroscopy. The structures are as follows: [formula: see text] where R is beta-L-threo-hex-4-enuronopyranosyl-(1-4)-alpha-Neu-(2-3)-beta-Gal A-(1-3)- beta-QuiN-(1-4)-beta-Sedf-(2- in 1, beta-Sedf-(2- in 2, and H in 3. Where not stated otherwise, sugars are pyranoses of the D-series. Hep is L-glycero-D-manno-heptose, QuiN is 2-amino-2,6-dideoxy-glucose, Kdo is 3-deoxy-D-manno-2-octulosonic acid, Sed is D-altro-heptulose and GalA is galacturonic acid.

Carbohydrate Sequence↗

PubMed1994

Chemical structure of the core region of Escherichia coli J-5 lipopolysaccharide.

The lipopolysaccharide of Escherichia coli J-5 was sequentially de-O-acylated, dephosphorylated, reduced, de-N-acylated, and N-acetylated. The products were separated by high-performance anion-exchange chromatography into a nonasaccharide (1), two octasaccharides (2, 3), and a heptasaccharide (4). Compositional analysis, methylation analysis, and NMR spectroscopy revealed the structures of the products as: alpha-D-GlcpNAc-(1-7)-L-alpha-D-Hepp-(1-7)-[alpha-D-Glcp-(1-3)-]-L -alpha-D- Hepp-(1-3)-R1, (1) L-alpha-D-Hepp-(1-7)-[alpha-D-Glcp-(1-3)-]-L-alpha-D-Hepp-(1 -3)-R1, (2) alpha-D-GlcpNAc-(1-7)-L-alpha-D-Hepp-(1-7)-[alpha-D-Glcp-(1-3)-]-L -alpha-D- Hepp-(1-3)-R2, (3) alpha-D-Glcp-(1-3)-L-alpha-D-Hepp-(1-3)-R1, (4) in which 1R is L-alpha-D-Hepp-(1-5)-[alpha-Kdop-(2-4)-]-alpha-Kdop-(2 -6)- beta-D-GlcpNAc-(1-6)-D-GlcN-Acol, and 2R is L-alpha-D-Hepp-(1-5)-alpha-Kdop-(2-6)-beta-D-GlcpNAc-(1-6 )-D- GlcNAcol (LD-Hep, L-glycero-D-manno-heptose; Kdo, 3-deoxy-D-manno-octulopyranosonic acid; GlcNAcol, 2-acetamido-2-deoxy-glucitol). Fast-atom-bombardment mass spectrometry of de-O-acylated and dephosphorylated lipopolysaccharide showed that the isolated oligosaccharides represented the complete carbohydrate moiety of the lipopolysaccharide, and indicated that the non-reducing terminal D-GlcN residue in lipopolysaccharide was present as the free base.

Carbohydrate Conformation↗

PubMed1995

The structure of the lipid A-core region of the lipopolysaccharides from Vibrio cholerae O1 smooth strain 569B (Inaba) and rough mutant strain 95R (Ogawa).

The lipopolysaccharides (LPS) from Vibrio cholerae 95R, a rough mutant strain of O1 V. cholerae 162 (Ogawa), and from smooth O1 V. cholerae 569B (Inaba) were de-O-acylated. In each case, one part of the products was treated with 48% aqueous HF which removed the phosphoryl and fructose residues, then reduced, de-N-acylated, and N-acetylated. Another part was de-N-acylated by treatment with hot KOH. The products of both degradation pathways were separated by high-performance anion-exchange chromatography. The major dephosphorylated and defructosylated product 1 was obtained in pure form, whereas the minor products 2 and 3 were eluted as a mixture, as were, from the second degradation, the phosphorylated oligosaccharides 4 (major product) and 5 (minor product). No phosphorylated component corresponding to oligosaccharide 3 could be identified by NMR spectroscopy in the latter mixture. The following structures of oligosaccharides 1-5 were established on the basis of monosaccharide and methylation analyses, Smith degradation, and 1H- and 13C-NMR investigations (correlated, total correlated, NOE and heteronuclear correlation spectroscopy; all sugars are present as alpha-D-pyranoses except where indicated otherwise; Hep, L-glycero-D-manno-heptose; Kdo, 3-deoxy-D-manno-2-octulosonic acid). [formula: see text] In the untreated lipopolysaccharide, the amino group of the non-reducing terminal glucosamine residue is not substituted.

Carbohydrate Sequence↗

PubMed1997

Elucidation of the structure of the core region and the complete structure of the R-type lipopolysaccharide of Erwinia carotovora FERM P-7576.

An R-type lipopolysaccharide (LPS) from Erwinia carotovora strain FERM P-7576 was studied after strong alkaline degradation and mild acid hydrolysis. The resulting products were analyzed by fast-atom bombardment mass spectrometry, one- and two-dimensional 1H and 13C NMR spectroscopy, dephosphorylation and methylation analysis. The following structure was proposed for the core region of the LPS: [formula in text] where Hep is L-glycero-D-manno-heptose and Kdo is 3-deoxy-D-manno-octulosonic acid. Some LPS species lack the beta-D-Galp residue or the beta-D-Galp-(1-->7)-alpha-Hepp disaccharide. With the known structures of lipid A [Fukuoka, S., Kamishima, H., Nagawa, Y., Nakanishi, H., Ishikawa, K., Niwa, Y., Tamiya, E. & Karube, I. (1992) Arch. Microbiol. 157, 311-318] and the core moiety, the complete LPS structure was established and confirmed by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry of the native and O-deacylated LPS.

Carbohydrate Conformation↗