Search Results
Results 501 - 550 of 1907
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Baka Zakaria A M - - 2002
The ultrastructure of intercellular hyphae and dikaryotic haustoria of Uromyces euphorbiae, and the host response to haustorial invasion was investigated. The intercellular hyphae share common characteristics with those of other uredinial stages of rust fungi. Three types of septa were recognized inside the intercellular hypha. This study showed that the ...
Kooistra Oliver - - 2002
Two modifications of 5-acetimidoylamino-7-acetamido-3,5,7,9-tetradeoxy-D-glycero-D-galacto-non-2-ulosonic acid (5-N-acetimidoyl-7-N-acetyllegionaminic acid) in the O-chain polysaccharide (OPS) of the Legionella pneumophila serogroup 1 lipopolysaccharide (LPS) concern N-methylation of the 5-N-acetimidoyl group in legionaminic acid. Both N-methylated substituents, the (N,N-dimethylacetimidoyl) amino and acetimidoyl(N-methyl)amino group, could be allocated to one single legionaminic acid residue in the long- ...
Kooistra Oliver - - 2002
Previously, a phase-variable epitope was detected in the virulent wild-type strain RC1 of Legionella pneumophila serogroup 1 subgroup OLDA using a lipopolysaccharide-specific monoclonal antibody, mAb 2625 [Lüneberg, E., Zähringer, U., Knirel, Y. A., Steinmann, D., Hartmann, M., Steinmetz, I., Rohde, M., Kohl, J. & Frosch, M. (1998) J.Exp. Med. 188, ...
Padmanabhan Kiran - - 2002
Previous reports have demonstrated the effectiveness of chitosan as a transfection agent. These studies have noted the importance of polysaccharide backbone interactions with the cell surface as well as cationic groups in the transfection process. The present study focuses upon the potential utility of another polysaccharide hydrogel, alginic acid, as ...
Choma Adam - - 2002
Lipopolysaccharides of two Mesorhizobium species of different host specificity were compared: M. huakuii and M. ciceri. M. huakuii sp. was represented by five strains with special consideration of M. huakuii IFO 15243(T). SDS/PAGE profiles revealed that all M. huakuii LPS preparations contained low molecular mass fractions (LPS-II) of the same ...
DiCesare N - - 2001
Sugar detection is important for many applications. New developments in sugar signaling would provide new technologies to monitor glucose and other sugars. Azo dye 1 presents a new way to build molecular color sensors for monosaccharides. The boronic acid group is used as chelator group for monosaccharides and linked directly ...
Hussein A - - 2001
Lipopolysaccharides (LPSs) of Chlamydophila psittaci 6BC and Chlamydophila pneumoniae Kajaani 6 contain 3-deoxy-D-manno-oct-2-ulosonic acid (Kdo), GlcN, organic bound phosphate, and fatty acids in the molar ratios of approximately 3:2:2.2:4.8 and approximately 2.9:2:2.1:4.9, respectively. The LPSs were immunoreactive with a monoclonal antibody against a family-specific epitope of chlamydial LPS. This finding, ...
Sun R C - - 2001
A new method has been developed for the quantitative determination of hydroxycinnamic acids participating in ester or ether linkages to the cell wall polymers. The method is based on mild alkaline hydrolysis followed by acid hydrolysis or mild alkaline hydrolysis, which partially removed esterified phenolic acids, and high-temperature concentrated alkaline ...
Hansen K M - - 2001
A simple method was developed for fast identification of pectin, based on a recombinant endopectate lyase cloned from Aspergillus niger. When pectin was demethylated and treated with pectate lyase, beta-elimination occurred, resulting in a double bond between C-4 and C-5 in the galacturonic acid residue of the released nonreducing end. ...
Bao X - - 2001
A polysaccharide with a molecular weight of 1.26 x 10(5), obtained from the sporoderm-broken spores of Ganoderma lucidum, was purified by anion-exchange and gel-permeation chromatography. This polysaccharide had a strong effect on suppressing the antibody production and the Con A or LPS induced lymphocyte proliferation in mice. Chemically, the structure ...
Mondal S K - - 2001
A water soluble gum polysaccharide was isolated from Murraya paniculata fruits. Hydrolytic experiments, methylation analysis, periodate oxidation studies and NMR data revealed that the polysaccharide was extensively branched and it consisted of 1,3-, and 1,3,6-linked beta-D-galactopyranosyl units, terminal beta-D-galactopyranosyl units and terminal alpha-D-glucopyranosyl 1,4-beta-D-galactopyranosyl units. Small amounts of 4-O-methylglucuronic acid ...
Bauer S H - - 2001
In view of the importance of 5-N-acetyl neuraminic acid in bacterial pathogenesis, a sensitive, reproducible and reliable method for the determination of 5-N-acetyl neuraminic acid levels in lipopolysaccharide (LPS) is described and applied to 24 different non-typeable Haemophilus influenzae (NTHi) strains. The method involves analysis by high-performance anion-exchange chromatography with ...
Tsvetkov Y E - - 2001
Derivatives of 5,7-diamino-3,5,7,9-tetradeoxynon-2-ulosonic acids are essential constituents of some bacterial polysaccharides and glycoproteins. In order to establish reliably the configuration of the natural sugars, nine stereoisomeric 5,7-diacetamido-3,5,7,9-tetradeoxynon-2-ulosonic acids were synthesized, including di-N-acetyl-legionaminic and -pseudaminic acids (the D-glycero-D-galacto and L-glycero-L-manno isomers, respectively) and their isomers at C-4, C-5, C-7, and C-8 ...
Ozaki N - - 2001
Coccolith is a calcified scale with species-specific fine structure produced by marine unicellular coccolithophorid algae, and consists of calcium carbonate crystals and organic matrices. EDTA-soluble organic materials extracted from coccoliths of Pleurochrysis carterae showed anti-calcification activity. They were separated by anion-exchange HPLC, and two fractions, fractions A and B, were ...
de Swaaf M E - - 2001
The valuable polyunsaturated fatty acid, docosahexaenoic acid, can be produced by cultivation of the heterotrophic microalga, Crypthecodinium cohnii. During batch growth of C. cohnii on glucose, sea salt and yeast extract for 5 days, so far unreported extracellular polysaccharides were produced. These caused an increased viscosity and a strong drop ...
Linker A - - 2001
The structure of an acidic exopolysaccharide (EPS) from eight strains of Burkholderia cepacia has been investigated by methylation and sugar analysis, periodate oxidation-Smith degradation, and partial acid-hydrolysis. An enzyme preparation obtained from the same organisms producing the EPS was also used to depolymerize the polysaccharide. Detailed NMR studies of the ...
Gyémánt G - - 2001
MALDI-TOF mass spectroscopy was used for the molecular weight determination of protected synthetic oligosaccharides related to a cell surface bacterial polysaccharide. By-products containing chlorinated protecting groups caused isotopic patterns characteristic of the natural isotopic distribution of chlorine, were identified on the basis of isotopic distribution. 2,4,6-Trihydroxyacetophenone (THAP) as a matrix ...
Cho D H - - 2001
The aim of this work was to characterize an exopolysaccharide by Rhodotorula glutinis KCTC 7989 and to investigate the effect of the culture conditions on the production of this polymer. The extracellular polysaccharide (EPS) produced from this strain was a novel acidic heteropolysaccharide composed of neutral sugars (85%) and uronic ...
Morimoto S - - 2001
We identified a novel metabolic system of morphine in the opium poppy (Papaver somniferum L.). In response to stress, morphine is quickly metabolized to bismorphine consisting of two morphine units, followed by accumulation in the cell wall. This bismorphine binds predominantly to pectins, which possess high galacturonic acid residue contents, ...
Chun H - - 2001
Polysaccharides are involved in biological responses and can activate complement system, which plays an important role in primary host defense mechanisms. We investigated anticomplementary activities from spice plants and selected thyme (Thymus vulgaris L.) as a potent complementary activator. Acidic polysaccharide (TV-3-IIIA-IIa) purified from the hot-water extract of thyme leaves ...
Manzo E - - 2001
A novel mild procedure for the selective cleavage of ketosidic linkages is developed using ceric ammonium nitrate (CAN) in anhydrous N,N-dimethylformamide. Its application to lipopolysaccharides (LPS) is very significant because in the so far investigated LPS, the connection between the Lipid A region and the oligo(poly)saccharide part is always a ...
Kondakova A N - - 2001
The O-specific polysaccharide of Proteus vulgaris O39 was found to contain a new acidic component of Proteus lipopolysaccharides, 5,7-diacetamido-3,5,7,9-tetradeoxy-L-glycero-L-manno-non-2-ulosonic acid (di-N-acetylpseudaminic acid, Pse5Ac7Ac). The following structure of the polysaccharide was determined by NMR spectroscopy, including 2D 1H,(1)H COSY, TOCSY, ROESY, and 1H,(13)C HMQC experiments, along with selective cleavage of the ...
Tømmeraas K - - 2001
Two chitosans with widely different chemical composition (fraction of N-acetylated units (F(A))<0.001 and F(A)=0.59), were degraded by nitrous acid, to obtain the reactive 2,5-anhydro-D-mannose- (M-) unit at the new reducing end. The fully N-acetylated and fully N-deacetylated oligomers were separated by size-exclusion chromatography. Both the chemical structure and purity were ...
Ishii T - - 2001
A borate-containing pectin was solubilized from sugar beet (Beta vulgaris L. ) cell walls by treatment with 0.5 M imidazole, pH 7. The molecular weight of the pectin was reduced when the borate ester was hydrolyzed by treatment with 1 N HCl. Treatment of the acid-treated pectin with boric acid ...
Popper Z A - - 2001
Acid hydrolysis of cell wall-rich material from young leaves of the lycophyte Selaginella apoda (L.) Spring yielded substantial amounts of 3-O-methyl-D-galactose (1) in addition to the usual major monosaccharides (glucose, galactose, arabinose, xylose and galacturonic acid). The yield of 1 approximately equalled that of galacturonic acid. Compound 1 was identified ...
Lam T B - - 2001
A suspension in dichloromethane-water (18:1, v/v) of various fractions containing hydroxycinnamic acid ester-ether bridges between lignin and polysaccharides prepared from cell walls of matured oat (Avena sativa L.) intemodes, and a solution of their acetates in the same solvent, were treated with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ). This reagent selectively cleaves benzyl ether ...
Yun Yang B - - 2001
The Erwinia chrysanthemi CU643 EPS has a linear hexasaccharide repeating unit in which a 4-linked uronic acid residue is present. The EPS was methylated by either the NaOH-Me2SO-MeI or Li-dimsyl procedure. MALDI-TOF MS analysis of the methylated products indicates that the beta-eliminative degradation occurs during the methylation, as characterized by ...
Kocharova N A - - 2001
The O-specific polysaccharide (OPS) was isolated by mild-acid degradation of the lipopolysaccharide of Vibrio cholerae O9 and studied by carboxyl reduction, sugar and methylation analyses, Smith degradation, and two-dimensional NMR spectroscopy, including COSY, TOCSY, NOESY, and H-detected 1H,(13)C HMQC experiments. The following structure of the pentasaccharide-repeating unit of the OPS ...
Sunish Kumar R - - 2001
In order to understand the mode of action of the taxonomically related pathogens Xanthomonas campestris pv. translucens, Xanthomonas oryzae pv. oryzae, and Xanthomonas oryzae pv. oryzicola, which attack wheat and rice crops, we examined the compositional differences of their exopolysaccharides (EPSs). Maximum production of polysaccharide in shake cultures of these ...
Isobe Y - - 2001
A bacterium which was isolated from pond water and identified as Enterobacter cloacae produced a viscous extracellular polysaccharide when it was grown aerobically in a medium containing sucrose as a sole source of carbon. The maximum molecular weight of the polysaccharide was about 9.0 x 10(5). The polysaccharide was composed ...
Vinogradov E - - 2001
The polysaccharides from the outer membrane of the Gram-negative ruminal bacterium Fibrobacter succinogenes were isolated by phenol/water extraction and separated by size-exclusion chromatography in the presence of deoxycholate detergent into a lower-molecular-mass fraction designated 'glycolipid' and a high-molecular-mass 'capsular polysaccharide' fraction. Both fractions lacked typical lipopolysaccharide components including 2-keto-3-deoxyoctulosonic acid ...
Ferro V - - 2001
Mild acid-catalysed hydrolysis of the extracellular phosphomannan of the yeast Pichia holstii NRRL Y-2448 produces a high-molecular-weight phosphomannan core, a low-molecular-weight oligosaccharide phosphate fraction, and a neutral oligosaccharide fraction. A method was developed for the large-scale preparation of the oligosaccharide phosphate fraction, consisting predominantly of the pentasaccharide phosphate, 6-O-PO3H2-alpha-D-Man-(1 --> ...
Dong Q - - 2001
A polysaccharide fraction, NIB-2, was obtained from the 3% aqueous sodium carbonate extract of Nerium indicum leaves using anion-exchange chromatography and gel-permeation chromatography. It was found to be composed of rhamnose, arabinose, galactose, in the ratios of 1.0:10.4:4.4, along with 4% of galacturonic acid. The results of methylation analysis, periodate ...
Naumova I B - - 2001
Data on the structures of cell wall teichoic acids, the anionic carbohydrate-containing polymers, found in many Gram-positive bacteria have been summarized and the polymers of the actinomycete genus Nocardiopsis have been considered from the taxonomic standpoint. The structures of these polymers or their combinations have been demonstrated to be indicative ...
Buck R A - - 2001
The effects of endodontic irrigants and calcium hydroxide on lipopolysaccharide (LPS; endotoxin) were analyzed using the highly selective technique of mass spectrometry/gas chromatography with selected ion monitoring. An aqueous solution of LPS was mixed with one of a variety of endodontic irrigants for 30 min. Because it is a commonly ...
Farzam F - - 2001
BACKGROUND: Subinhibitory concentrations of antibiotics, which can occur in vivo, have been demonstrated to alter the production of bacterial virulence factors, including the capsule, or the interaction between microorganism and phagocyte by affecting surface hydrophobicity. METHODS: Using a microtiter assay system, the effect of subinhibitory concentrations of amikacin, gentamicin, cephalothin ...
Gross M - - 2001
Staphylococcus aureus is responsible for a large percentage of infections associated with implanted biomedical devices. The molecular basis of primary adhesion to artificial surfaces is not yet understood. Here, we demonstrate that teichoic acids, highly charged cell wall polymers, play a key role in the first step of biofilm formation. ...
Cogez V - - 2001
We report the initial characterization of the osmoregulated periplasmic glucans (OPGs) of Erwinia chrysanthemi. OPGs are intrinsic components of the bacterial envelope necessary to the pathogenicity of this phytopathogenic enterobacterium (F. Page, S. Altabe, N. Hugouvieux-Cotte-Pattat, J.-M. Lacroix, J. Robert-Baudouy and J.-P. Bohin, J. Bacteriol. 183:0000-0000, 2001 [companion in this ...
Tsvetkov Y E - - 2001
5,7-Diacetamido-3,5,7,9-tetradeoxy-D-glycero-D-galacto- and -D-glycero-D-talo-non-2-ulosonic acids were synthesized by condensation of 2,4-diacetamido-2,4,6-trideoxy-D-mannose with oxalacetic acid. Comparison of the 1H and 13C NMR data and the specific optical rotation values of these monosaccharides and the corresponding L-glycero-D-galacto and L-glycero-D-talo isomers synthesized earlier [Tsvetkov, Y. E.; Shashkov, A. S.; Knirel, Y. A.; Backinowsky, L. ...
Gulin S - - 2001
The exocellular polysaccharide S-7, a heteropolysaccharide from Azotobacter indicus var. myxogenes has been studied using methylation analysis, Smith degradation, partial acid hydrolysis, NMR spectroscopy and mass spectrometry as the principal methods. It is concluded that the repeating unit has the following structure: [structure: see text] The absolute configuration of the ...
Schubert K - - 2001
The cell wall of Erysipelothrix rhusiopathiae was investigated. The corrected structure of the murein, which was published earlier, is reported here. The murein belongs to the B1delta type. It has L-alanine in position three of the peptide subunit and is crosslinked via a glycine-L-lysine-L-lysine interpeptide bridge. As expected by the ...
Jiménez A - - 2001
Cellulose and hemicelluloses obtained from the cell walls of partially depectinated olives have been studied at three stages of ripening (green, cherry, and black). Hemicelluloses were fractionated into two groups, the amounts of which diminished during ripening: those soluble in 4% KOH diminished between the cherry and black stages, whereas ...
Zdorovenko G M - - 2001
Lipopolysaccharide (LPS) was isolated from the phytopathogenic bacterium Pseudomonas syringae pv. atrofaciens IMV 948 by mild extraction of the microbial cells with saline, and the properties, composition, and structure of the LPS were studied. The LPS showed low toxicity in D- galactosamine-sensitized mice and low biological activity in plants. Structural ...
Faber E J - - 2001
The lactic acid bacterium Lactobacillus delbrueckii subsp. bulgaricus 291, when grown in skimmed milk, produced 80 mg/L exopolysaccharide with an average molecular mass of 1.4 x 10(3) kDa. Monosaccharide analysis, methylation analysis, MS, and 1D/2D NMR (1H and 13C) studies performed on the native polysaccharide, and on oligosaccharides obtained from ...
Perepelov A V - - 2001
A high-molecular-mass O-specific polysaccharide was obtained by mild acid degradation of Proteus vulgaris O4 lipopolysaccharide followed by GPC. The polysaccharide was studied by chemical methods along with 1H and 13C NMR spectroscopy, including two-dimensional COSY, TOCSY, NOESY, H-detected 1H,13C HMQC, and 1H,13C HMBC experiments. Solvolysis of the polysaccharide with trifluoromethanesulfonic ...
Huisman M M - - 2001
Structural characteristics of pectic substances extracted from soybean meal cell walls (water unextractable solids) with a chelating agent-containing buffer (0.05M 1,2-diaminocyclohexane-N,N,N',N'-tetraacetic acid (CDTA) and 0.05M NH(4)-oxalate in 0.05M NaOAc buffer) were studied. The arabinogalactans present as side chains to the rhamnogalacturonan backbone were largely removed by enzymatic hydrolysis using endo-galactanase, ...
Park K M - - 2001
The effects of an acidic polysaccharide isolated from the ethanol-insoluble and water-soluble fraction of Panax ginseng C. A. Meyer on immunomodulating activities were investigated. A high output nitric oxide synthase (iNOS) was shown in female BALB/c mice administered intraperitoneally with the acidic polysaccharide from ginseng. Newly synthesized iNOS protein was ...
Tako M - - 2001
An alginate was isolated from commercially cultured Nemacystus decipiens which had been harvested in Yonashiro Town (Okinawa, Japan). The yield of the alginate was 1.6% (w/w of wet alga), and the uronic acid, ash and moisture contents of the alginate were 86.0%, 12.0%, and 2.3% (w/w), respectively. The molecular mass ...
Smith B G - - 2001
The ester-linkage of ferulic acid (mainly E) to polysaccharides in primary cell walls of pineapple fruit (Ananas comosus) (Bromeliaceae) was investigated by treating a cell-wall preparation with 'Driselase' which contains a mixture of endo- and exo-glycanases, but no hydroxycinnamoyl esterase activity. The most abundant feruloyl oligosaccharide released was O-[5-O-(E-feruloyl)-alpha-L-arabinofuranosyl](1-->3)-O-beta-D-xylopyranosyl-(1-->4)-D-xylopyranose (FAXX). ...
Vinogradov E - - 2001
The structure of lipid A-core region of the lipopolysaccharide (LPS) from Klebsiella pneumoniae serotype O3 was determined using NMR, MS and chemical analysis of the oligosaccharides, obtained by mild acid hydrolysis, alkaline deacylation, and deamination of the LPS: [carbohydrate structure see text] where P is H or alpha-Hep; J is ...
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