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PubMed1995

Digestibility characteristics of isomaltooligosaccharides in comparison with several saccharides using the rat jejunum loop method.

Isomaltooligosaccharides (IMO) are a mixture of isomaltose, isomaltotriose, panose, isomaltotetraose, etc. IMO and its hydrogenated derivative (IMH) were characterized for their luminal clearance from rat jujunum loops as the indication of their digestibility. They were compared with a disaccharide fraction (IM2) and a higher oligosaccharide fraction (IM3) prepared from IMO, typical digestible saccharides (maltose, maltotriose, and sucrose), and typical nondigestible saccharides (maltitol, raffinose, and fructooligosaccharides (FO)). The clearance rate of IMO was significantly smaller than that of IM2, which was mainly composed of isomaltose (64.3%), and digestible saccharides, and significantly larger than that of nondigestible saccharides. That of IM2 was almost the same as that of sucrose or maltotriose but significantly smaller than that of maltose. That of IM3 tended to be smaller than that of IMO, and larger than that of nondigestible saccharides. That of IMH was significantly smaller than that of IMO and similar to that of maltitol. These results seem to indicate that IMO is slowly digested in the jejunum, that the components having higher degree of polymerization of IMO are less digestible, and that IMH is nondigestible.

Animals↗
PubMed2005

Effects of saccharides on brain function and cognitive performance.

This review outlines a role for saccharides in the brain and offers predictions about how saccharides might influence cognitive performance. Animal studies provide a biological mechanism by which saccharides affect brain function and, in turn, cognition. Furthermore, recent intervention studies suggest that saccharides may have an effect on the cognitive performance of humans. Because the effects of saccharide supplementation on cognitive performance are likely to be subtle, future investigations will face various methodological challenges, not the least of which is the need for sensitive outcome measures.

Animals↗
PubMedDate not supplied

Quantitative determination of saccharides in dietary glyconutritional products by anion-exchange liquid chromatography with integrated pulsed amperometric detection.

A new technique for the assay of carbohydrates is described in which separation and quantification of neutral saccharides, aminosaccharides, glycuronic acids, and disaccharides may be accomplished in less than 50 min of total run time. This method involves optimized anion-exchange liquid chromatography coupled with integrated pulse amperometric detection. Complex carbohydrates from various sources, including dietary supplements, were hydrolyzed in a dilute solution of trifluoroacetic acid, freeze-dried, and reconstituted in water containing 2-deoxygalactose as the internal standard. The solution was filtered and separated on CarboPac PA20 column. The eluted saccharides were detected by oxidation on a gold electrode with quadruple-pulsed integrated amperometry. The calibration plots for the saccharides were linear with an average correlation coefficient of 0.999. Method precision regarding peak retention time and resolution used in the peak identifications was verified. With this method, previously difficult-to-separate saccharides, such as galactosamine, glucosamine, and N-acetylglucosamine, were successfully resolved from the neutral saccharides rhamnose, arabinose, and galactose. Mannose was also resolved from xylose, and de-acetylation of aminosaccharides prior to separation was not necessary. This technique provides an accurate and efficient means to assay carbohydrates in dietary supplements, which new federal regulations will soon mandate.

Acetylgalactosamine↗
PubMed1991

Changes in saccharide and phospholipid content associated with drug storage in cultured rabbit aorta muscle cells.

In the investigation of cellular changes associated with intracellular drug storage, we incubated cultured rabbit aorta muscle cells with various amphiphilic agents. Disobutamide, chloroquine, and desipramine each increased cellular content of rhamnose, arabinose, mannose, glucose, and total saccharides; these agents also elevated total and individual phospholipid of all classes. Amiodarone did not alter total saccharide content, but increased total phospholipid. Tilorone, in contrast, decreased total saccharides, but phospholipid content was unchanged. All test agents decreased xylose content. By light microscopy, disobutamide, chloroquine, and tilorone induced clear cytoplasmic vacuoles; desipramine induced dense cytoplasmic granules; and amiodarone induced both cytoplasmic changes. By electron microscopy, the content of the cellular alterations induced by disobutamide was primarily electron lucent; that of the alterations induced by desipramine was primarily concentric lamellar bodies/flocculent electron-dense structures; and that of the alterations induced by amiodarone was a mixture of both. There was no correlation, therefore, between the induced cellular chemical contents and morphologic changes. Despite the physicochemical similarity of the amphiphilic drugs (all have cationic and lipophilic moieties), the chemical responses they induced were different. The results suggest that amphiphilic drugs alter processes involving saccharides as well as those of phospholipid metabolism. The origin of the saccharide moieties associated with the induced changes in monosaccharide contents is not known. Increased content of phosphatidylinositol, mannose, and glycosyl residues is consistent with the suggestion that amphiphilic drugs may cause an increase in membrane anchor synthesis. The inhibition of lysosomal enzyme activities responsible for the degradation of phospholipid and other anchors may also account for the observed increase in monosaccharides and phosphatidylinositol content.

Amines↗
PubMed1975

Optical properties of lysozyme. pH and saccharide binding difference spectra.

Difference spectra associated with changes in pH and with binding of saccharides have been recorded for hen egg white (HEW) lysozyme, turkey egg white (TEW) lysozyme, and for the derivatives of the hen protein in which Tre-62 or Trp-108 had been oxidized specifically to oxindolealanine to give the Oxa-62 or Oxa-108-proteins. Identical pH difference spectra were obtained for HEW, TEW, and Oxa-62-lysozymes. Oxidation of Trp-108 is reflected in both the high and low pH (pH 7 versus 5 and pH 2 versus 5) difference spectra. The magnitude of the low pH difference spectrum is enhanced by binding of saccharide for HEW and Oxa-62-lysozymes but not for TEW lysozyme. The shapes and magnitudes of saccharide binding difference spectra are affected by oxidation of residues 62 or 108. These results can be interpreted in terms of the perturbations responsible for the lysozyme difference spectra. The pH 7 versus 5 difference spectrum results from perturbation by Glu-35 of Trp-108 and another tryptophan, probably Trp-63. Perturbation of Trp-108 and one or more other tryptophan residues by several carboxylate groups is responsible for the low pH difference spectra of the unliganded HEW and TEW lysozyme molecules. Perturbation of Trp-108 makes a principal contribution to the saccharide-binding difference spectrum. Perturbation of the Oxa-108 chromophore by ionization of Glu-35 or by saccharide binding produces absorbance changes in the 250 to 265 nm region.

Acetylglucosamine↗
PubMed1982

[Utilization of proteins in rats with different fat and saccharide intakes].

For 14-day periods, 30-day-old and 90-day-old male rats were fed ad libitum the diets with a constant protein content (casein) of 10 p. c. and with an increased fat content (margarine) of 10, 20. 30, 40 and 50 p.c. (first experiment) and then the diets with a constant protein content (casein) of 10 p. c. and with a constant fat content (margarine) of 30 p. c. (30-day rats) and of 11 p. c. (90-day rats) and with an increasing saccharide content of 31, 36, 41, 46 and 51 p. c. (90-day rats were further fed by 56, 61 and 66 p. c.) composed of rice starch, sugar and potato starch at a ratio of 6.4 : 1.2 :1 (second experiment). Net protein utilization (NPU) was determined on the basis of body nitrogen content and protein intake. The animal liver was examined for the gluconeogenesis by measuring the specific activity of phosphoenolpyruvate carboxykinase (PEPCK). The highest NPU value can be achieved as follows: in 30-day animals by administration of the feeds containing 30 p. c. of fat, 36 p. c. of saccharides; in 90-day animals by 10 p. c. of fat and 51 p. c. of saccharides. Under the optimum nutrition conditions, both age groups utilize protein in the same way. The extreme nutrition conditions are better tolerated by the just weaned animals than by 90-day animals. The results of this biological method were also proved by the course of gluconeogenesis (activated at 40 and 50 p. c. fat content and 31 p. c. saccharide content in the diet fed to 30-day animals; in 90-day animals the activation occurred beginning 20 p. c. fat content and at 31 to 46 p. c. saccharide content). This paper contributes to the determination of optimum physiological nutrient rates by biological and biochemical methods.

Animals↗
PubMedDate not supplied

Molecular recognition of saccharides using synthesized glycated surface active reagents.

The molecular recognition of saccharides was studied using N-glycosides, glycated surface active reagents synthesized by the glycosyl reaction from alkylamines and monosaccharides. The alkylamines selected were octyl and dodecylamines because of their hydrophobicity. Glucose and mannose were selected as an energy saccharide and a structural saccharide, respectively. The synthesized glycated surface-active reagents were added as components of the carrier solution used for capillary electrophoresis, and the selective molecular recognition of saccharides was studied using several nitrogen-containing compounds. The migration times of the cationic forms of nitrogen-containing compounds were delayed by interaction with the N-glycosides. However, this system did not show clear selectivity between glucose and mannose.

Amines↗
PubMed2002

1,1'-Binaphthyl-substituted macrocycles as receptors for saccharide recognition.

The preparation of receptors for saccharide recognition in a natural environment has been an unmet goal for a long time. We present herein the synthesis and binding properties of (R,S)-1,1'-binaphthyl-substituted macrocycles as receptors for saccharide recognition in water/acetonitrile (1:1) and in DMSO. Porphyrin and metalloporphyrin macrocycles with two to four 1,1'-binaphthyl substituents and multiple hydroxy groups generate a binding site for saccharides that incorporates hydrogen-bonding hydroxy groups together with the aromatic hydrophobic pocket. The specificity for di- and trisaccharides is governed by the cavity size. The mechanism of binding has been studied by 1H NMR spectroscopy and the role of H-bonding and CH-pi interactions has been evaluated; the ability to bind saccharides has been demonstrated by the surface plasmon resonance (SPR) technique. The application of these macrocyclic receptors to sensor development is also presented.

Biosensing Techniques↗
PubMed1978

Capping of saccharides on the plasma membrane of lymphocytes as studied by fluorescein-labelled lectins.

The capping of saccharides on the plasma membrane of rat splenic lymphocytes was studied by means of fluorescein-labelled lectins. Treatment of unfixed splenic lymphocytes with any one of the three lectins, concanavalin A (Con A), Ricinus communis agglutinin (RCA) and wheat germ agglutinin (WGA) led to the formation of caps of each saccharide receptor on the plasma membrane. Treatment of unfixed lymphocytes with Con A was found to result in the formation of caps of saccharide receptors for RCA, whereas cap formations were never noted in such double treatment of the cells with all other combined uses of two lectins. These results are taken to indicate that the saccharide receptors for Con A are associated with those for RCA in the plasma membrane of rat splenic lymphocytes.

Animals↗
PubMed2006

Structural analysis of a novel saccharide isolated from fermented beverage of plant extract.

Fermented beverage of plant extract was prepared from about 50 kinds of vegetables and fruits. Natural fermentation was carried out mainly by lactic acid bacteria (Leuconostoc spp.) and yeast (Zygosaccharomyces spp. and Pichia spp.). Three kinds of saccharides have been found in this beverage and produced by fermentation. The saccharides isolated from the beverage using carbon-Celite column chromatography and preparative HPLC, were identified as a new saccharide, beta-d-fructopyranosyl-(2-->6)-d-glucopyranose, laminaribiose and maltose by examination of constituted sugars, GLC and GC-MS analyses of methyl derivatives and MALDI-TOF-MS and NMR measurements of the saccharides.

Beverages↗
PubMed2005

Controlled release of saccharides from matrix tablets.

The aim of this study was to design site specific, controlled release tablets of N-acetyl-d-glucosamine (NAG), maltose monohydrate and maltopentaose by using hydrophobic matrix formers starch acetate (SA) and ethyl cellulose (EC). The optimized matrices, which had either low porosity and high drug load or high porosity and low drug load, released the saccharides within the desired 2-4 h. In general, it was possible to control the release rate of saccharides by altering the relative amount of hydrophobic matrix former in the tablet and tablet porosity. The release type of saccharides from these formulations varied from immediate release to sustained release. In the case of sustained release formulations, it was found that the release of maltose monohydrate and maltopentaose was biphasic and slower than the release rate of NAG from similar tablets. NAG release kinetics followed square root of time kinetics, while in the case of maltose monohydrate and maltopentaose, the release kinetics were zero order in both phases. The biphasic dissolution profile was proposed to be caused by water mediated recrystallisation of the disordered material formed during the dissolution. Both SA and EC matrices were found to represent suitable controlled oral delivery vehicles for saccharides.

Acetylglucosamine↗
PubMed2000

Quantitative determination of saccharide in Haemophilus influenzae type b glycoconjugate vaccines, alone and in combination with DPT, by use of high-performance anion-exchange chromatography with pulsed amperometric detection.

The stability and integrity of glycoconjugate vaccines requires determination of the total saccharide and quantification of the unbound or free saccharide present. The traditional assay for Hib conjugates, based on colorimetric determination of ribose, has been much improved by the use of base hydrolysis and analysis of the Hib subunit generated using high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD). The production of this subunit was confirmed by NMR analysis. However, quantification of free Hib saccharide using this method was not possible in the combination vaccines evaluated due to interferences emanating from DPT. Thus a method based on TFA hydrolysis followed by the chromatographic separation and quantification of ribitol on a CarboPac MA1 column was developed. The method is selective, and with the use of ED40 electrode, requires only nanomole amounts for the chromatographic step, thereby ensuring that free saccharide can be monitored accurately in the formulated Hib-CRM vaccine alone and when in combination with other vaccines.

Carbohydrates↗
PubMed2005

Development of an aerosol chemiluminescent detector coupled to capillary electrophoresis for saccharide analysis.

A novel aerosol chemiluminescent (CL) detector coupling to capillary electrophoresis (CE) for the detection of saccharides is reported. This CL detector is composed of a postcapillary nebulizer and porous alumina as catalyzer in quartz tube. The CL emission could be generated due to the catalyzing oxidization of saccharides on the surface of porous alumina. The saccharides such as sucrose, alpha-lactose, maltose, raffinose, galactose, xylose, and glucose with only weak UV absorbance can be successfully detected. The linear ranges of those saccharides are from 30-2000 to 50-2000 mg/L; relative standard deviations range from 2.1 to 3.7% (200 mg/L, n = 11). Compared with the traditional UV detector currently used in CE, this novel detector shows the advantage of high sensitivity to the compounds with only weak UV absorption. Thus, it could be an important supplement of CE detectors for UV-lacking compounds.

Aerosols↗
PubMed1993

Orientation of the saccharide chains of glycolipids at the membrane surface: conformational analysis of the glucose-ceramide and the glucose-glyceride linkages using molecular mechanics (MM3).

Preferred conformations of the saccharide-ceramide linkage of glucosylceramides with different ceramide structures (normal and hydroxy fatty acids) were investigated by molecular mechanics (MM3) calculations and compared with conformational features obtained for glucosylglycerolipids (diacyl and dialkyl analogues). Relaxed energy map calculations with MM3 were performed for the three bonds (C1'-O1-C1-C2, torsion angles phi, psi, and theta 1) of the glucose-ceramide/diglyceride linkage at different values of the dielectric constant. For the phi torsion of the glycosidic C1'-O1 bond the calculations show a strict preference for the +sc range whereas the psi/theta 1 energy surface is dependent on the structure of the lipid moiety as well as on the dielectric constant (epsilon). Calculations performed on glucosylceramide with normal and hydroxy fatty acids at epsilon = 4 (bilayer subsurface conditions) show three dominating conformers (psi/theta 1 = ap/-sc, -sc/ap, and ap/ap). The ap/-sc conformer, which represents the global energy minimum, is stabilized by polar interactions involving the amide group. The +sc rotamer of theta 1 is unfavored in sphingolipids due to a Hassel-Ottar effect involving the sphingosine O3 and O1 oxygen atoms. Comparative calculations on glycosylglycerolipid analogues (ester and ether derivatives) show a distinct preference for the ap rotamer of theta 1. An evaluation of the steric hindrance imposed by the surrounding membrane surface shows that in a bilayer arrangement the range of possible conformations for the saccharide-lipid linkage is considerably reduced. The significance of preferred conformations of the saccharide-ceramide linkage for the presentation and recognition of the saccharide chains of glycosphingolipids at the membrane surface is discussed.

Carbohydrate Conformation↗
PubMed1978

Conformation as the determinant of saccharide binding in concanavalin A: Ca2+-concanavalin A complexes.

The existence of two conformational states of concanavalin A (Con A) with different metal ion binding properties has been recently demonstrated (Brown, R. D., Brewer, C. F., & Koenig, S. H. (1977) Biochemistry 16, 3883). Introduction of Mn2+ to the S1 site and Ca2+ to the S2 site of apo-Con A was shown to induce a conformational change in the protein, ascribed to a cis-trans isomerization of a peptide bond in the secondary structure, which results in extremely tight binding of the metal ions. This induced conformation is referred to as "locked" and the initial conformation as "unlocked". The locked ternary complex is identical with the native protein. In the present paper, we report evidence for the formation of a relatively stable, locked, ternary Ca2+-Con A complex that possesses properties similar to those of native Ca2+-Mn2+Con A. The experimental technique involves measurement of the magnetic field and time dependence of the nuclear magnetic relaxation rate (1/T1) of solvent water protons in solutions of Ca2+-Con A, after the addition of Mn2+ ion which slowly bind to the protein. The kinetic data can be fit by a model for Ca2+ interactions with Con A which indicates that Ca2+, in the absence of Mn2+, can bind at both the S1 and S2 sites of the protein and, furthermore, can induce the protein to undergo the unlocked to locked conformational transition. In terms of this model, the time-dependent binding of the Mn2+ ions is due to replacement of Ca2+ ions at the S1 sites in the locked protein. The off-rate of Ca2+ from the S2 site of the locked ternary Ca2+-Con A complex is much greater than that from the locked Ca2+-Mn2+-Con A complex. From the effects of added alpha-methyl D-mannopyranoside on the rate of replacement of Ca2+ by Mn2+ at the S1 site of the locked ternary Ca2+-Con A complex, it is concluded that the latter complex binds saccharides as strongly as the locked Ca2+-Mn2+-Con A complex. In addition, analysis of the data indicates that apo-Con A in the locked conformation binds alpha -methyl D-mannopyranoside with approximately 7% of the affinity of the fully metallized locked form of the protein. This strong saccharide-binding activity of locked apo-Con A, compared with that of the unlocked apo-Con A, was further demonstrated by equilibration of unlocked apo-Con A with alpha-methyl D-mannopyranoside, which resulted in the formation of the locked apo-Con A-saccharide complex. These results demonstrate that it is the locked conformation of Con A that is primarily responsible for saccharide-binding activity, and that the function of the bound metals is primarily to maintain the protein in the locked conformation.

Apoproteins↗
PubMed1999

Allylmalonamide as a bivalent linker: synthesis of biantennary GM3-saccharide--keyhole limpet hemocyanin glycoconjugate and the immune response in mice.

A biantennary GM3-saccharide (sialyllactoside) derivative (4) was constructed using allylmalonic acid as a bivalent linker, both carboxylic acids of which were condensed with 3-aminopropyl lactoside (2) prior to enzymatic sialylation with a fusion enzyme. While ozonolysis of its allyl group generated a saccharide having a terminal aldehyde (6), we were unable to couple 6 directly to protein by reductive amination. However, extension of the spacer by means of introducing a maleimide group to 6 through its aldehyde group to give 7 enabled the latter to be successfully coupled to thiolated proteins. The average ratios of saccharide to protein were observed to be 35 in KLH conjugate (13) and 9-12 in HSA conjugates (14 and 15). The antisera obtained by immunizing mice with the biantennary sialyllactoside-KLH conjugate (13) together with MPL adjuvant were analyzed by ELISA. Using several structurally related saccharide-HSA conjugates as screening antigens, it was concluded that anti-sialyllactoside antibodies, both IgG and IgM, were effectively raised. This was further supported by competitive inhibition experiments using lactoside (1), sialyllactoside (8) and biantennary sialyllactoside (4) as inhibitors.

Adjuvants, Immunologic↗
PubMed2003

Saccharide imprinting of poly(aniline boronic acid) in the presence of fluoride.

A new approach for the electrosynthesis of saccharide-imprinted poly(aniline boronic acid) is described. The method involves the formation of a saccharide-aminophenylboronic acid complex in the presence of fluoride to allow the electropolymerization of a self-doped, molecularly imprinted polyaniline. The formation of the anionic monomer complex enables electrochemical polymerization at near neutral pH (5-7) ensuring the incorporation of saccharide in the resulting, self-doped polymer. In this work, films were imprinted with D-fructose where saccharide-aminophenylboronic acid complexation occurred in the presence of one equivalent of fluoride. The selectivity toward D-fructose relative to D-glucose showed an increase of over 25% as a result of imprinting. In addition to the enhanced selectivity, to the best of our knowledge this is the first example of the electropolymerization of a self-doped polyaniline homopolymer under neutral pH conditions.

Journal Article↗
PubMed1999

A strategy for rapid sequencing of heparan sulfate and heparin saccharides.

Sulfated glycosaminoglycans (GAGs) are linear polysaccharides of repeating disaccharide sequences on which are superimposed highly complex and variable patterns of sulfation, especially in heparan sulfate (HS). HS and the structurally related heparin exert important biological functions, primarily by interacting with proteins and regulating their activities. Evidence is accumulating that these interactions depend on specific saccharide sequences, but the lack of simple, direct techniques for sequencing GAG saccharides has been a major obstacle to progress. We describe how HS and heparin saccharides can be sequenced rapidly by using an integrated strategy with chemical and enzymic steps. Attachment of a reducing-end fluorescent tag establishes a reading frame. Partial selective chemical cleavage at internal N-sulfoglucosamine residues with nitrous acid then creates a set of fragments of defined sizes. Subsequent digestion of these fragments with combinations of exosulfatases and exoglycosidases permits the selective removal of specific sulfates and monosaccharides from their nonreducing ends. PAGE of the products yields a pattern of fluorescent bands from which the saccharide sequence can be read directly. Data are presented on sequencing of heparin tetrasaccharides and hexasaccharides of known structure; these data show the accuracy and versatility of this sequencing strategy. Data also are presented on the application of the strategy to the sequencing of an HS decasaccharide of unknown structure. Application and further development of this sequencing strategy, called integral glycan sequencing, will accelerate progress in defining the structure-activity relationships of these complex GAGs and lead to important insights into their biological functions.

Carbohydrate Sequence↗