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Results 601 - 650 of 1907
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Kurek B - - 2000
This paper reports the modification/degradation of lignin within spruce sawdust by manganese complexes formed by the association of MnO(2) and oxalate. The Mn oxidants formed are shown to modify both the chemical and physical properties of the wood cell wall. Scanning electron microscopy analysis of oxidized tracheids revealed a smoothing ...
Thompson J E - - 2000
Neutral xyloglucan was purified from the cell walls of suspension-cultured rose (Rosa sp. 'Paul's Scarlet') cells by alkali extraction, ethanol precipitation and anion-exchange chromatography on 'Q-Sepharose FastFlow'. The procedure recovered 70% of the total xyloglucan at about 95% purity in the neutral fraction. The remaining 30% of the xyloglucan was ...
Svobodová H - - 2000
The present study focused on changes in the annual dynamics of the contents of non-structural saccharides (NSS) of Norway spruce vegetative buds related to their structural development under the effect of acidic pollution during the year 1995. Two types of material were analysed: (1) 4-year-old trees treated for 2 years ...
Gamian A - - 2000
Lipopolysaccharide was extracted from cells of Salmonella enterica serovar Toucra O48 and, after mild acid hydrolysis (1% AcOH, 1 h, 100 degrees C or 0.1 M NaOH-AcOH, pH 4.5, 5 h, 100 degrees C), the O-specific polysaccharide was isolated and characterized. The core and an oligosaccharide containing a fragment of ...
Bystrova O V - - 2000
An acidic O-specific polysaccharide was obtained by mild acid degradation of the lipopolysaccharide of the bacterium Providencia alcalifaciens O7 and purified by gel chromatography followed by anion-exchange chromatography. On the basis of full acid hydrolysis, methylation, carboxyl reduction, selective cleavage with anhydrous hydrogen fluoride, and 1H- and 13C-NMR spectroscopy, including ...
Farquharson S I - - 2000
The cell-surface carbohydrates of Porphyromonas gingivalis strain ATCC 53978 were isolated and partially characterized. Three separate polysaccharides were found to be present: an extracellular polysaccharide, capsular polysaccharide and lipopolysaccharide. The capsular polysaccharide, which had peculiar, gel-like viscoelastic properties, was found to be comprised of mannuronic acid, glucuronic acid, galacturonic acid, ...
Jerić I - - 2000
The increasing prevalence of sepsis from gram-positive bacterial pathogens necessitates further evaluation of the basic assumptions about the molecular pathogenesis of septic shock. Since diverse physiological functions of gram-positive bacteria are controlled by the degree of esterification of teichoic acids with D-alanine, we examined the reactivity of monosaccharide esters in ...
Lee S D - - 2000
A new actinomycete strain, LM 042T, which was isolated from a gold-mine cave in Kongju, Republic of Korea, is described by phenotypic and genotypic characters. The organism formed short chains of non-motile spores and globose bodies from substrate mycelium. An aerial mycelium was absent. This organism was chemotaxonomically characterized by ...
Monchois V - - 2000
Glucansucrases of oral streptococci and Leuconostoc mesenteroides are enzymes of medical and biotechnological interest that synthesize alpha-glucans. They can also synthesize oligosaccharides in the presence of a sugar acceptor. Previous reports have identified an amino acid residue that may affect the structure of the glucan product; therefore, random mutagenesis of ...
Plötz B M - - 2000
According to the 16 S rRNA phylogenetic tree, the hyperthermophilic bacterium Aquifex pyrophilus represents the deepest and shortest branching species of the kingdom Bacteria. We show for the first time that an organism, which is phylogenetically ancient on the basis of its 16 S rRNA and that exists at extreme ...
Basu S S - - 2000
Galacturonic acid (GalA) is a major component of plant cell-wall-derived pectins. It can be also found in the cell-surface polysaccharides of different microorganisms, including several symbiotic and pathogenic bacteria. Uridine diphosphogalacturonic acid (UDP-GalA) is a likely donor for GalA during the biosynthesis of these polysaccharides. A highly efficient, yet simple, ...
Guo S - - 2000
Seven novel saponins were isolated from a bark extract of Quillaja saponaria Molina. the compounds were characterized, using mainly NMR spectroscopy, mass spectrometry and chemical methods, as quillaic acid substituted at C-3 with oligosaccharides consisting of various compositions of D-glucuronic acid D-galactose, D-xylose, and L-rhamnose and at C-28 with complex ...
Redgwell R J - - 2000
Cell wall material (CWM) was prepared from sun-dried cocoa (Theobroma cacao L.) bean cotyledons before and after fermentation. The monosaccharide composition of the CWM was identical for unfermented and fermented beans. Polysaccharides of the CWM were solubilised by sequential extraction with 0.05 M trans-1,2-diaminocyclohexane-N,N,N',N'-tetraacetic acid (CDTA), 0.05 M Na2CO3, and ...
Wong A W - - 2000
Alkylsulfonates are examined as anion dopants for the matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS) of neutral oligosaccharides. The anion dopants allow neutral oligosaccharides to be examined in the same mixture as acidic oligosaccharides. The alkylsulfonate dopants interact strongly with the oligosaccharide to produce a quasimolecular ion composed of the oligosaccharides and ...
Belogortseva N I - - 2000
Polysaccharides from the roots of Panax ginseng were extracted by hot water and fractionated by using ethanol precipitation and ion exchange chromatography. Fractions FC (crude extract), F1 (fraction precipitated by ethanol), F1N (fraction unbound to DEAE-Sepharose CL-6B), and F1A (bound fraction) were obtained. Their carbohydrate analyses showed that acidic fraction ...
Shashkov A S - - 2000
A teichoic acid from the cell walls of Nocardioides luteus VKM Ac-1246T, a validly described species of the Nocardioides genus, is a 1,5-poly(ribitol phosphate) completely substituted at C-4 by alpha-D-galactopyranosyl residues carrying a 4,6-pyruvate ketal group in R-configuration. The structure of the repeating unit of the polymer is as follows: ...
Ahrazem O - - 2000
The polysaccharides obtained from the alkali-extractable, water-soluble fraction (F1SS) from the cell wall of Myrothecium verrucaria and Myrothecium atroviride were shown to be composed of beta-(1-->6)-galactofuranose fully substituted at O-2 by terminal residues of alpha-glucopyranose and alpha-glucuronic acid. Glucuronic acid was substituted at O-4 by glucopyranose in the Myrothecium species ...
Hagner-Mcwhirter A - - 2000
In the biosynthesis of heparin and heparan sulphate, D-glucuronic acid residues are converted into L-iduronic acid (IdoA) units by C-5 epimerization, at the polymer level. The reaction catalysed by the epimerase occurs by reversible abstraction and readdition of a proton at C-5 of target hexuronic acid residues, through a carbanion ...
Perepelov A V - - 2000
A phosphorylated O-specific polysaccharide (O-antigen) was obtained by mild acid degradation of Proteus vulgaris O12 lipopolysaccharide and studied by sugar and methylation analyses, 1H-, 13C- and 31P-NMR spectroscopy, including two-dimensional COSY, TOCSY, NOESY, H-detected 1H, 13C and 1H, 31P heteronuclear multiple-quantum coherence experiments. It was found that the polysaccharide consists ...
Helm R F - - 2000
The structure of the viscous extracellular polysaccharide (glycan) of desiccation-tolerant Nostoc commune DRH-1 was determined through chromatographic and spectroscopic methods. The polysaccharide is novel in that it possesses a 1-4-linked xylogalactoglucan backbone with D-ribofuranose and 3-O-[(R)-1-carboxyethyl]-D-glucuronic acid (nosturonic acid) pendant groups. The presence of D-ribose and nosturonic acid as peripheral ...
Lopes M H - - 2000
The monomeric composition of suberin extracts obtained by gradual alkaline methanolysis of Quercus suber cork was determined by gas chromatography-mass spectrometry (GC-MS). Results show that 1-alkanols and alkanoic and alpha,omega-alkanedioic acids are preferentially removed upon mild alkaline conditions, whereas mid-chain-modified omega-hydroxyalkanoic acids are preferentially removed under stronger alkaline conditions. Saturated ...
Perepelov A V - - 2000
An O-specific polysaccharide was obtained by mild acid degradation of P. mirabilis O29 lipopolysaccharide (LPS) and found to contain 2-acetamido-2-deoxy-D-galactose and D-glucuronic acid (D-GlcA) in the ratio 3:1. Studies of the polysaccharide by 1H- and 13C-NMR spectroscopy including two-dimensional correlation spectroscopy (COSY), total correlation spectroscopy (TOCSY), nuclear Overhauser effect spectroscopy ...
Knirel Y A - - 2000
An acidic O-specific polysaccharide was obtained by mild acid degradation of the Proteus penneri 8 lipopolysaccharide and found to contain D-glucose, D-galacturonic acid, 2-acetamido-2-deoxy-D-glucose, 2-acetamido-2-deoxy-D-galactose, 2-acetamido-2,6-dideoxy-L-galactose (L-FucNAc) and 2-aminoethyl phosphate (PEtn) in the ratios 2 : 1 : 1 : 1 : 1 : 1. 1H and 13C NMR spectroscopy ...
Sogawa K - - 2000
We have previously purified an extracellular polysaccharide, D-galactan sulfate associated with L(+)-lactic acid, produced from a marine microalga Dinoflagellate Gymnodinium sp. A3 (GA3). The GA3 polysaccharide, irrespective of presence or absence of lactic acid, exhibited significant cytotoxicity, which is based on an induction of apoptotic cell death, toward human myeloid ...
Curtino J A - - 2000
Glycogen synthase of bovine retina was found associated with the acid-insoluble and acid-soluble proteoglycogen fractions. The synthase associated with the acid-insoluble proteoglycogen precursor showed an 8-fold lower Km for UDP-glucose than the synthase associated with the acid-soluble fraction, and was inhibited by detergent. A short digestion with pronase resulted in ...
Katz S S - - 1999
Deacylation of purified lipopolysaccharides (LPS) markedly reduces its toxicity toward mammals. However, the biological significance of LPS deacylation during infection of the mammalian host is uncertain, particularly because the ability of acyloxyacyl hydrolase, the leukocyte enzyme that deacylates purified LPS, to attack LPS residing in the bacterial cell envelope has ...
de Vries R P - - 1999
Feruloyl esterases can remove aromatic residues (e.g., ferulic acid) from plant cell wall polysaccharides (xylan, pectin) and are essential for complete degradation of these polysaccharides. Expression of the feruloyl esterase-encoding gene (faeA) from Aspergillus niger depends on D-xylose (expression is mediated by XlnR, the xylanolytic transcriptional activator) and on a ...
Nakata K - - 1999
Klebsiella pneumoniae H12 produced a newly identified extracellular polysaccharide in an ethanol medium with a yield of 3.0 g/l. The molar composition of the polysaccharide was 56.04% galactose, 25.92% glucose, 10.92% galacturonic acid, 3.71% mannose, and 3.37% glucuronic acid. The addition of 0.5%-1.5% NaCl increased production. The polysaccharide flocculated with ...
Saraf A - - 1999
The in vitro potency of house dust to induce cytokine response in A549 lung epithelial cells was studied. Dusts collected from carpet, bed, shelf and floor of a villa and an apartment by vacuuming were found to trigger the production of interleukin-8 (IL-8) and interleukin-6 (IL-6) in a dose-dependent manner, ...
Gloaguen V - - 1999
The capsular polysaccharide produced by the thermophilic cyanobacterium Mastigocladus laminosus has been subjected to a specific degradation with lithium in ethylenediamine. The released undecasaccharide attached to one unit of tetrahydroxycyclopentanecarboxylic acid has been characterized by a combination of 2D nuclear magnetic resonance spectroscopy, mass spectrometry, monosaccharidic composition and linkage analyses. ...
Limb J K - - 1999
Monoacetyldiglycerides (MADGs) were isolated from an animal tissue, bovine udder, by solvent extraction and silica gel column chromatography. Monoacetyldiglyceride structures were identified using a variety of 1-D and 2-D NMR techniques and collision-induced dissociation (CID) tandem mass spectrometry coupled with fast atom bombardment. CID of sodium-adducted molecular ions ([M+ Na](+)) ...
Molinaro A - - 1999
Xanthomonas hortorum pv. vitians is a Gram-negative bacterium that acts as the causative agent of bacterial leaf spot and headrot in lettuce. The lipopolysaccharide (LPS) of this bacterium is suspected to be an important molecule for adhesion to the plants. We have isolated the LPS, prepared the lipid A and ...
Gerdt S - - 1999
Caenorhabditis elegans displays three neutral glycosphingolipids with structural homology to glycosphingolipids from the porcine nematode parasite, Ascaris suum. The present findings extend the degree of structural conservation between the two nematode species to glycosphingolipids with a phosphodiester substitution. Using a combination of hydrofluoric acid pretreatment, immunochemical characterization and matrix-assisted laser ...
Lahooti M - - 1999
The cell walls of Gram-positive bacteria consist primarily of a macromolecular matrix comprising similar amounts of peptidoglycan and covalently attached anionic polymers. Under most growth conditions the anionic polymers of Bacillus subtilis are principally teichoic acids; in strain 168 these include a polyglycerol teichoic acid and a glucose/galactosamine-containing teichoic acid. ...
Krasikova I N - - 1999
Prior studies have shown some unusual changes in the lipopolysaccharides (LPSs) from Yersinia pseudotuberculosis that occur when the microbe is grown at low temperature; the specific features of these LPSs in comparison with the LPSs from other enteropathogens may be due to unusual thermal adaptation mechanisms. To gain insight into ...
Bystrický S - - 1999
The cross-linking effect of adipic acid dihydrazide (ADH) on polysaccharide derivatization can be evaluated by applying combination of elemental analysis and colorimetric assay. Elemental analysis is used for estimation of total ADH bound to polysaccharide and a colorimetric trinitrobenzene sulfonic acid assay is used to determine the part of ADH ...
Rodríguez R - - 1999
The main polysaccharides involved in asparagus cell wall turnover have been identified. Homogalacturonans are lost from both the apical and basal sections of the spear. Galactans are mobilized from the cellulose residue of the apical section and recovered in the KOH-soluble fractions while they are lost from the cellulose residue ...
Dermlim W - - 1999
Sixteen strains of polymer-producing bacteria were isolated from the activated sludge samples taken from two seafood processing plants in Southern Thailand. Their culture broths possessed the ability to flocculate kaolin suspension in the presence of 1% CaCl2. Based on the flocculating activity, the strain S11 was selected and identified to ...
Schneider O - - 1999
Lipoteichoic and teichoic acids are components of the cell wall of Streptococcus pneumoniae. A recently developed enzyme immunoassay was used in patients with pneumococcal meningitis to investigate lipoteichoic and teichoic acid concentrations in CSF at the first lumbar puncture in relation to the clinical outcome determined by the Glasgow Outcome ...
Trinel P A - - 1999
In a series of studies, we have shown that Candida albicans synthesizes a glycolipid, phospholipomannan (PLM), which reacted with antibodies specific for beta-1,2-oligomannosides and was biosynthetically labeled by [(3)H]mannose, [(3)H]palmitic acid, and [(32)P]phosphorus. PLM has also been shown to be released from the C. albicans cell wall and to bind ...
Romanenko A S - - 1999
The properties of extracellular polysaccharides of the potato ring rot pathogen Clavibacter michiganensis subsp. sepedonicus (Cms) and the corresponding recognition sites isolated from cell walls of potato suspension cultures have been studied. Extracellular polysaccharides of Cms consist of 4-6 components, which differ greatly in molecular mass (from <1 kD to ...
Walker S G - - 1999
Isolation of a putative lipopolysaccharide from the surface of the oral treponeme, Treponema pectinovorum, revealed it to contain larger amounts of 3-deoxy-D-manno-octulosonic acid compared with other oral Treponema species. This molecule was isolated from the outer membrane of T. pectinovorum and had chemical characteristics of a putative lipopolysaccharide. The yield ...
Sedlaczek L - - 1999
beta-Sitosterol side chain degradation by Mycobacterium sp. NRRL MB 3683 results in the formation of androstene derivatives and is increased in the presence of glycine. As the sterol transformation is carried out inside the cell, higher product accumulation could indicate faster diffusion of highly hydrophobic substrate through the cell wall ...
Theocharis A D - - 1999
A new non-sulphated acidic polysaccharide with an average molecular mass of 55 kDa was isolated from squid pen case after papain digestion and beta-elimination. This polysaccharide contains mainly L-iduronic acid, D-glucuronic acid, D-galactosamine, D-glucosamine and significant amounts of neutral sugars as glucose, galactose and fucose. The polysaccharide was not degraded ...
Rodríguez R - - 1999
The postharvest changes of the white asparagus cell wall have been studied in relation to the toughening process along the length of a spear that was divided into three sections: apical, middle, and basal. Polysaccharides underwent significant turnover during storage. Uronic acid concentration decreased in all sections and in almost ...
Corsaro M M - - 1999
An exopolysaccharide obtained from an alkaliphilic bacterium closely related to Bacillus spp. was found to contain D-galactopyranuronic acid (GalpA), 2,4-diacetamido-2,4,6-trideoxy-D-glucopyranose (QuipNAc4NAc), 2-acetamido-2-deoxy D-mannopyranuronic acid (ManpNAcA) and one uncommon unit of D-galactopyranuronic acid with the carboxyl group amide-linked to glycine [GalpA(Gly)]. The polysaccharide was studied by one-dimensional and two-dimensional 1H-NMR and ...
McSweeney C S - - 1999
Microorganisms that hydrolyse the ester linkages between phenolic acids and polysaccharides in plant cell walls are potential sources of enzymes for the degradation of lignocellulosic waste. An anaerobic, mesophilic, spore-forming, xylanolytic bacterium with high hydroxy cinnamic acid esterase activity was isolated from the gut of the grass-eating termite Tumilitermes pastinator. ...
Severn W B - - 1999
The specific capsular polysaccharide produced by Rhodococcus equi serotype 4 was found to be a high-molecular-weight acidic polymer composed of D-glucose, D-mannose, pyruvic acid and a previously unidentified 5-amino-3,5-dideoxynonulosonic (rhodaminic) acid in the proportions 2:1:1:1. Structural analysis, employing a combination of microanalytical methods, nuclear magnetic resonance spectroscopy, and mass spectrometric ...
González LF - - 1999
Incubation of oat coleoptile segments with 40 µm indoleacetic acid (IAA) induced a decrease of 35-60% in peroxidase activity at the cell wall compartment. Treatment with IAA also produced a similar decrease in the oxidation of NADH and IAA at the cell wall. Isoelectric focusing of ionic, covalent, and intercellular ...
Kerwin J L - - 1999
Glucosamine (Gln), glucosamine polymers, and their catecholamine adducts were characterized using positive ion electrospray mass spectrometry (ESMS) and tandem mass spectrometry (ESMS-MS). N-acetyldopamine (NADA), a catecholamine found in many insect cuticles, was oxidized using mushroom tyrosinase, and the resulting quinone derivatives were reacted with Gln, (Gln)3, and polymeric glucosamine (chitosan). ...
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