Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “DISACCHARIDES”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

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

At least 127 records · Page 7Linked to original sources
PubMed2005

Analysis of the disaccharides derived from hyaluronic acid and chondroitin sulfate by capillary electrophoresis with sample stacking.

CE conditions for monitoring the unsaturated disaccharides of hyaluronic acid (di-HA) and chondroitin sulfate (di-CS) using an alkaline tetraborate buffer, electrokinetic sample injection, and UV absorption detection at 232 nm are reported. Separations were performed in an uncoated fused-silica capillary having reversed polarity and reversed electroosmosis generated with the addition of CTAB to the buffer. The influence of various separation parameters, including the concentration of CTAB, buffer pH, concentration of tetraborate, and applied voltage, on the resolution of the two disaccharides was investigated. Baseline separation was obtained with 25 mM tetraborate at pH 10.0 and having 0.05 mM CTAB. Chloride and phosphate in the sample are beneficial for the stacking of the disaccharides, with di-HA forming a much sharper peak than di-CS. Using samples prepared in 25 mM Tris-HCl (pH 7.5) and electrokinetic injection at the cathode at -10 kV for 40 s, linear relationships between the corrected peak area and the concentration of the disaccharides have been found in the ranges of 1.0-400.0 and 0.1-1.0 microg/mL (0.2-1.0 microg/mL for di-CS), with correlation coefficients being >0.9933 in all cases. The RSDs of detection times and corrected peak areas were between 1.13-1.24 and 1.57-2.13%, respectively. Applied to human serum samples that were prepared by ethanol precipitation and depolymerization of the two polysaccharides with chondroitinase ABC reveals comigration of endogenous compounds with di-HA and a sample-dependent detection time. The di-HA content in the serum sample can be estimated via subtraction of the blank peak that is obtained without enzymatic hydrolysis.

Chondroitin Sulfates↗
PubMed1995

Microanalysis of glycosaminoglycan-derived disaccharides labeled with the fluorophore 2-aminoacridone by capillary electrophoresis and high-performance liquid chromatography.

A series of disaccharides derived from chondroitin sulfate and heparin/heparan sulfate were derivatized at their reducing ends with the fluorophore 2-aminoacridone. The resulting labeled compounds derived from chondroitin sulfate or heparin/heparan sulfate were well separated and could be quantified by capillary electrophoresis and HPLC with a fluorescence detector. This method was successfully applied to the analysis of the disaccharide composition of sulfated tetra- and hexasaccharides derived from chondroitin sulfate and heparin/heparan sulfate. Remarkably, the saturated and the corresponding unsaturated chondrodisaccharides, the structures of which differ only in their nonreducing terminal uronic acid residues, were also well separated from each other by capillary electrophoresis. This facilitated disaccharide composition analysis of saturated chondrooligosaccharides prepared by testicular hyaluronidase digestion as well as unsaturated chondro- and heparin/heparan sulfate-oligosaccharides prepared by digestion with chondroitinases and heparitinases. The developed method employing the derivatization by 2-aminoacridone in conjunction with capillary electrophoresis or HPLC with a fluorescence detector allows a simple, sensitive, and quantitative disaccharide composition analysis of the glycosaminoglycan-derived oligosaccharides.

Aminoacridines↗
PubMed2000

Modified GOESY in the analysis of disaccharide conformation.

One-dimensional nuclear magnetic resonance techniques were applied to the conformational investigation of a disaccharide. More specifically, nuclear Overhauser enhancements (NOEs) of protons on either side of the glycosidic bond have been used to determine the conformation of the disaccharide alpha-l-Rhap-(1 --> 2)-alpha-l-Rhap-OMe. A modified GOESY sequence, incorporating selective excitation and pulsed field gradient enhancement, was developed and used to accurately measure small NOE signals of interest. These experiments were named M-GOESY, for modified GOESY, and the data they provided were used to calculate internuclear distances in the disaccharide molecule. The accuracy of the M-GOESY measurements was enhanced by elimination of indirect effects, or spin diffusion, by selective inversion(s) of either the intermediate magnetization or the source and target magnetization during the mixing time. Results of this study indicate that the alpha-l-Rhap-(1 --> 2)-alpha-l-Rhap-OMe disaccharide molecule exists primarily in one conformation, with the glycosidic torsion angle psi approximately -30 degrees based on past molecular dynamics simulations.

Disaccharides↗
PubMed1994

Tandem mass spectrometry for characterization of unsaturated disaccharides from chondroitin sulfate, dermatan sulfate and hyaluronan.

Fast atom bombardment tandem mass spectrometry has been used in the characterization of non-, mono-, di- and trisulfated disaccharides from chondroitin sulfate, dermatan sulfate and hyaluronan. The positional isomers of the sulfate group of mono- and disulfated disaccharides were distinguished from each other by both positive- and negative-ion fast atom bombardment tandem mass spectra, which gave sufficient information characteristic of the isomers. The anomeric isomers of nonsulfated disaccharides were characterized by the technique in the positive-ion mode. This fast atom bombardment collision induced dissociation mass spectrometry/mass spectrometry technique was also applied successfully to the characterization of trisulfated disaccharide.

Carbohydrate Conformation↗
PubMed1996

Synthesis of the disaccharides methyl 4-O-(2'/3'-O-sulfo-beta-D-glucopyranosyluronic acid)-2-amino-2-deoxy-alpha-D-glucopyranoside disodium salts, related to heparin biosynthesis.

The synthesis of the disaccharides methyl 4-O-(2'/3'-O-sulfo-beta-D-glucopyranosyluronic acid)-2-amino-2-deoxy-alpha-D-glucopyranoside 3 and 4 as disodium salts is described. Allyl 4,6-O-benzylidene-alpha-D-glucopyranoside 6 was converted to trichloroacetimidate 20. Glycosylation of 20 with 5 promoted by BF3.OEt2 gave disaccharide 21. Deacetylation of 21 followed by monoacetylation of the resultant diol 22 afforded the two monoacetylated disaccharides 23 and 24. Sulfation and deprotection of each disaccharide gave the desired sulfated compounds 3 and 4.

Chromatography, High Pressure Liquid↗
PubMed1976

Stimulation of the gerbil's gustatory receptors by disaccharides.

The gustatory responses from the chorda tympani nerve of the Mongolian gerbil, Meriones unguiculatus, were treated with 13 disaccharides. Sucrose was the most stimulatory sugar. The ability of fructosyl glycosides to stimulate may depend upon the linkage between fructose and the glycoside. Disaccharides possessing 1 leads to 3, 1 leads to 4, or 1 leads to 6 linkages were poor stimuli compared to sucrose which has a 1 leads to 2 linkage. Glucopyranosyl disaccharides with an alpha-linkage were better stimuli than the beta-anomers, while galactopyranosyl disaccharides possessing a beta-linkage were better than their alpha-amoners.

Animals↗
PubMed1993

The synthesis of chemically modified disaccharide derivatives of the Shigella flexneri Y polysaccharide antigen.

Disaccharide analogs related to the 2-acetamido-2-deoxy-3-O-(alpha-L- rhamnopyranosyl)-beta-D-glucopyranose element of the Shigella flexneri Y polysaccharide antigen have been synthesized and used to map the binding site of murine monoclonal antibodies GC-4 and SYA/J6 by solid-phase inhibition assays. N-Acetyl, N-trifluoroacetyl and N-benzyloxycarbonyl derivatives of methyl-2-amino-4,6-O-benzylidene-2-deoxy-beta-D-glucopyranoside 1, 3, and 4 were glycosylated by rhamnopyranosyl bromide and thioglycoside donors 5 and 6. These in turn provided access to a series of alpha-L-Rha p-(1-->3)-beta-D-GlcNp-(1-->O)-Me disaccharide glycosides with amino 13, N-acetyl 10, N-propionyl 14, N-pivaloyl 15, and N-trifluoroacetyl 11 functionalities. Congeners of the disaccharide 10 were synthesized with monodeoxy groups introduced at the C-4 and C-6 positions of the GlcNAc residues and at the C-4' position of the rhamnose unit. Chlorosulfation of the selectively protected disaccharide 24, followed by reduction of the 4-chloro-4-deoxy compound 25, was used to prepare the 4-deoxy congener 27, while the C-6 and C-4' deoxy derivatives 31 and 23 were assembled from their respective pre-functionalized monosaccharide building blocks 29 and 19.

Carbohydrate Sequence↗
PubMed1993

Influence of sulfate and carboxylate groups on the conformation of chondroitin sulfate related disaccharides.

1H NMR and 13C NMR spectral parameters of eight sulfated uronic acid containing disaccharides 1-8 were used to determine the conformational preferences that depend on the pattern of sulfation. Three sulfated derivatives of benzyl beta-D-Gal-(1-->4)-beta-D-GlcA (1), its 6'-sulfate 2, 4'-sulfate 3, and 4',6'-disulfate 4 were used as models for the beta-(1-->4) glycosidic linkage of chondroitin sulfates and three sulfated derivatives of benzyl beta-D-GlcA-(1-->3)-beta-D-Gal (5), its 6-sulfate 6, 4-sulfate 7, and 4,6-disulfate 8 were used as models for the beta-(1-->3) glycosidic linkage of chondroitin sulfates. To determine the dependence of conformational preferences on the charged groups, the sulfated disaccharides 2, 3, and 4 were compared to their unsulfated parent compound 1, and 6, 7, and 8 were compared to their parent compound 5. The 3JH-5,H-6 coupling constants were determined by high-order analysis of the spin systems, and from these the preferred populations of the hydroxymethyl groups were calculated. Selective 1D NOEs and ROEs were measured from H-1' across the glycosidic linkage to obtain the average distance of the protons adjacent to the glycosidic linkage. Derivatives of beta-D-Gal-(1-->4)-beta-D-GlcA carrying a sulfate group in the 6'-position (2) and in the 4'- and 6'-position (4) show a slight repulsive effect between the 6'-sulfate groups and the carboxylate group as expressed in small changes of the preferred populations of the glycosidic linkage and the sulfonyloxymethyl group. The 4-sulfate groups in 3 and 4 do not show a significant influence on the glycosidic linkage. However, the two sulfate groups in 4 exhibit a repulsive effect leading to a very high population of the gt conformation of the sulfonyloxymethyl group. In contrast hereto, the sulfate group at C-4 of beta-D-GlcA-(1-->3)-beta-D-Gal disaccharides 7 and 8 and the carboxylate group exert an attractive interaction that leads to a change of the conformation of the glycosidic linkage in 7 and 8 by about 30 degrees. The 6-sulfate groups of the disaccharides 6 and 8 show a slight repulsive interaction with the carboxylate and/or 4-sulfate group. Changes in 13C NMR chemical shifts support the interpretation obtained from the NOE and ROE analysis.(ABSTRACT TRUNCATED AT 400 WORDS)

Carbohydrate Conformation↗
PubMed1994

Synthesis of allyl 3-deoxy- and 4-deoxy-beta-D-galactopyranoside and simultaneous preparations of Gal(1-->2)- and Gal(1-->3)-linked disaccharide glycosides.

Syntheses of galactose derivatives that are useful in probing the binding specificity of galactose-specific lectins are reported. These include allyl 3-deoxy- and 4-deoxy-beta-D-xylo-hexopyranoside and several disaccharide glycosides having Gal(1-->2) and Gal(1-->3) linkages. The beta-linked Gal disaccharide isomers were produced using 2,3,4,6-tetra-O-acetyl-alpha-D-galactopyranosyl bromide as glycosyl donor and the 4,6-O-benzylidene derivatives of allyl beta-D-galactopyranoside, alpha-D-glucopyranoside, alpha-D-mannopyranoside, and 2-acetamido-2-deoxy-alpha-D-galactopyranoside as acceptors. Only the Gal(1-->3)-linked disaccharide was obtained when the benzylidene derivatives of the mannopyranoside and 2-acetamido-2-deoxygalactopyranoside were used. Attempts at the preparation of Gal(alpha, 1-->2)Gal and Gal(alpha, 1-->3)Gal disaccharide glycosides were made using the same strategy, but employing the 1-trichloro-acetimidate or 1-N-methylacetimidate of 2,3,4,6-tetra-O-benzyl-D-galactopyranose as the glycosyl donor. The latter imidate produced a mixture of Gal(alpha, 1-->2)Gal and Gal(alpha, 1-->3)Gal derivatives as major products, but the former gave the Gal(beta, 1-->2)Gal isomer as the major product.

Carbohydrate Sequence↗
PubMed1995

Synthesis and glycosaminoglycan priming activity of three disaccharides related to the linkage region tetrasaccharide of proteoglycans.

To test if disaccharides might serve as primers of oligosaccharide synthesis in animal cells, we synthesized 2-naphthyl O-(beta-D-galactopyranosyl)-(1 --> 4)-beta-D-xylopyranoside, 2-naphthyl O-(beta-D-galactopyranosyl)-(1 --> 3)-beta-D-galactopyranoside, and 2-naphthyl O-(beta-D-glucopyranosyluronic acid)-(1 --> 3)-beta-D-galactopyranoside. These three disaccharides are related to subunits of the linkage tetrasaccharide of heparan sulfate and chondroitin sulfate chains in animal cell proteoglycans. The disaccharides were synthesized with coupling efficiencies of 40-70% using thioglycosides or by activating the monosaccharides with trichloroacetimidate. The structures of these compounds were confirmed by 1H NMR, 13C NMR and elemental analysis. The ability of these disaccharides to prime glycosaminoglycan chains was examined in a Chinese hamster ovary cell mutant, p gsA 745, which lacks xylosyltransferase. The missing enzyme renders the cells dependent on exogenous primers for making glycosaminoglycan chains. 2-Naphthyl O-(beta-D-galactopyranosyl)-(1 --> 3)-beta-D-galactopyranoside and 2-naphthyl O-(beta-D-glucopyranosyluronic acid)-(1 --> 3)-beta-D-galactopyranoside did not stimulate glycosaminoglycan synthesis, but 2-naphthyl O-(beta-D-galactopyranosyl)-(1 --> 4)-beta-D-xylopyranoside at high concentration primed chains. The peracetylated derivative (2-naphthyl O-(2,3,4,6-tetra-O-acetyl-beta-D-galactopyranosyl)-(1 --> 4)- 2,3-di-O-acetyl-beta-D-xylopyranoside) primed chains at lower concentration (100 microM), suggesting that cells took up the compound and removed the acetyl groups apparently in the compartment where glycosaminoglycan synthesis occurs.

Acetylation↗
PubMed1995

Separation of hydroxyl protected heparin derived disaccharides using reversed-phase high-performance liquid chromatography.

A simple and efficient method for the separation of hydrophobic derivatives of glycosaminoglycan-derived disaccharides is described. Hydroxyl-protected derivatives of a trisulfated disaccharide, prepared from heparin using heparin lyase, were separated by reversed-phase high-performance liquid chromatography. These disaccharide derivatives differed by the number, position, and stereochemistry of acetyl and pivaloyl groups. Separation was achieved on a C18 column using a reversed gradient of ammonium sulfate in water. This method has application in the purification of disaccharide derivatives being used as chiral synthons in the preparation of higher oligosaccharides.

Carbohydrate Sequence↗
PubMed1996

Capillary electrophoresis of heparin and dermatan sulfate unsaturated disaccharides with triethylamine and acetonitrile as electrolyte additives.

Capillary electrophoresis at constant voltage with the addition of triethylamine as electrolyte to a running buffer containing borate using fused-silica capillaries permits the complete resolution in less than 30 min of 11 standard heparin and 8 standard dermatan sulfate disaccharides, which represent degradation products of heparin and dermatan sulfate by specific lyases. Triethylamine influences the migration time of disaccharides by reducing both their electrophoretic mobility towards the anode and the electroosmotic flow towards the cathode. A modulated combination of these effects together with borate-disaccharide complex formation is responsible for separation, especially in the case of isomers which differ in the position of the sulfate groups. The addition of acetonitrile did not introduce any favourable effect in the separation of disaccharide mixtures. Under these conditions different dermatan sulfates were analysed to assess the source of the preparations.

Acetonitriles↗
PubMed1992

Preparation of unsaturated disaccharides by eliminative cleavage of heparin and heparan sulfate with heparitinases.

1. Six kinds of unsaturated disaccharides were prepared by enzymatic digestion of heparin and heparan sulfate with heparitinases I0 and IV, and subsequent column chromatography. They were identified by HPLC showing good separation from each other. 2. The content of each unsaturated disaccharide fraction was determined colorimetrically, and found to range from 130.7 to 722.3 mumol. 3. Molecular extinction coefficient of each unsaturated disaccharide was calculated from absorbance at a wavelength of around 230 nm where a peak appeared on the ultraviolet spectrum of each disaccharide solution at pH 2. The values varied from 6000 to 6600.

Animals↗
PubMed2005

Development of specific inhibitors for heparin-binding proteins based on the cobra cardiotoxin structure: an effective synthetic strategy for rationally modified heparin-like disaccharides and a trisaccharide.

Recently, a new heparin disaccharide-binding site on the convex side of cobra cardiotoxin (CTX) was identified by NMR spectroscopy and molecular modeling. To further characterize this site two heparin-like disaccharides were synthesized for binding studies with CTX, and a trisaccharide was synthesized for testing the sequence of the disaccharide binding to CTX. Thus six differentially protected monosaccharide building blocks (three l-iduronic acids and three d-glucosamines) were prepared. These include a l-iduronic acid elongation building block namely methyl 2-O-acetyl-4-O-levulinoyl-3-O-pivaloyl-alpha-l-idopyranosyluronate trichloroacetimidate for which a single-crystal X-ray structure was determined to have M(r)=576.79, a=9.3098(11)A alpha=90 degrees , b=10.3967(12)A beta=90 degrees , c=28.026(3)A gamma=90 degrees , V=2712.7(6)A(3), P2(1)2(1)2(1), Z=4, mu=0.71073A, and R=0.0378 for 7586 observed reflections. It shows that the molecular structure of the donor is in the (1)C(4) conformation with significant 1,3-diaxial interactions between O-1 and O-3 as well as O-2 and O-4. The disaccharides and trisaccharide vary in the degree and position of O- and N-sulfation. The pivaloyl group was used as permanent protecting group of hydroxyl. The levulinoyl group was used as the temporary protecting group to protect the hydroxyl for elongation.

Animals↗
PubMed2005

Analysis of proteoglycans derived sulphated disaccharides by liquid chromatography/mass spectrometry.

A method has been developed for the identification and quantitative determination of sulphated disaccharides derived from chondroitin sulphate (CS) and dermatan sulphate (DS) chains attached to proteoglycans (PGs). After digestion with Chondroitinase ABC, the pool of disaccharides can be directly separated by liquid chromatography on a porous graphitized carbon (PGC) column and identified by on-line electrospray mass spectrometry under negative ionization conditions. The relative intensities of the fragment ions obtained by MS/MS allow to distinguish the sulphate position. Calibration with standard disaccharides allows the quantification of the different isomers. The method showed good repeatability in terms of relative standard deviation (RSD < 2%) and linearity between 0.5 and 50 ng (total injected amount) for both 4- and 6-sulphated disaccharides. The limit of detection achieved in full scan mode was 0.1 ng. The methodology was applied to different types of biological samples obtained from patients suffering from chronic lung inflammation such as: lung tissue, bronchoalveolar lavage fluid (BALF), induced sputum and urine.

Bronchoalveolar Lavage Fluid↗
PubMed2006

Development of a robust method for the quantitative determination of disaccharides in honey by gas chromatography.

An iterative method for the GC quantitative determination of TMS-oxime disaccharides in honey has been developed. This approach takes into account possible positive systematic errors caused by unidentified compounds which overlap with the expected disaccharides. The results of its application to the determination of 15 disaccharides in simulated honey samples indicate that the iterative method is more robust that methods based on least-squares regression, improves the accuracy of the quantitative analysis and allows to detect the possible presence of disaccharides not identified.

Chromatography, Gas↗
PubMed2001

Role of the sugar moiety in the pharmacological activity of anthracyclines: development of a novel series of disaccharide analogs.

The sugar moiety is an essential component of anthracycline antibiotics for their topoisomerase poisoning activity and antitumor efficacy. Since the sugar interacts with the minor groove, modifications in this moiety could enhance the recognition potential of the drug at the target level. Based on this hypothesis, novel anthracyclines, disaccharides lacking the amino group in the first (aglycone-linked) sugar, were designed. The 3'-amino group in the first sugar was replaced by an hydroxyl group, and the second sugar residue was bound to the first sugar via an alpha (1-4) linkage. The cytotoxic and antitumor activities of disaccharide analogs of idarubicin were critically dependent on the optimal (axial) orientation of the second sugar residue. Although configurational requirements of the sugar moiety for optimal drug activity support a critical role of the external (non-intercalating) drug domains in the interaction of anthracyclines with the DNA-topoisomerase (ternary complex), the antitumor efficacy of disaccharide analogs is not fully explained by effects mediated by the nuclear enzyme target. The development of this novel disaccharide series may provide insights for a rational synthesis of anthracycline analogs with improved pharmacological profile.

Anthracyclines↗
PubMed1977

Determination of the linkages of disaccharides containing a 2-acetamido-2-deoxy sugar unit by solvent effects in circular dichroism.

The circular dichroism spectra of 2-acetamido-2-deoxy sugars in 1,1,1,3,3,3-hexafluoro-2-propanol (F6Pr-2-ol) solutions show a positive band in the n-pi region (209 nm) in contrast to a negative c.d. band in water solution. This difference is interpreted as an indication of a change in the average orientation of the hydroxyl groups adjacent to the amide group. C.d. spectra of 2-acetamido-2-deoxy sugars having a methyl group at O-1 and O-3 confirm this interpretation and suggest that the c.d. spectrum of a disaccharide in F6Pr-2-ol reflects strongly the disaccharide linkage. Large differences in the c.d. spectra of (1 leads to 4) and (1 leads to 6)-linked disaccharides in this solvent lead to rules for distinguishing the linkages of the disaccharides.

Acetylgalactosamine↗