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PubMed2002

Palladium(II)-catalyzed transfer vinylation of protected monosaccharides.

A method for the catalytic vinylation of protected monosaccharides bearing a single free hydroxyl function has been developed. Reaction of representative primary, secondary, and anomeric sugar hydroxyl functions with butyl vinyl ether as the reactant and solvent and (phen)Pd(OAc)(2) (phen = 1,10-phenanthroline ligand) as the catalyst gives the corresponding vinylated sugar products in 36-79% yield. The catalyst requires the presence of traces of oxygen in the reaction mixture to prevent decomposition to Pd(0).

Journal Article↗
PubMed1998

Development of glycosylated human interleukin-1alpha, neoglyco IL-1alpha, coupled with D-galactose monosaccharide: biological activities in vivo.

In our previous study, a galactose monosaccharide with C9 spacer was chemically coupled to recombinant human interleukin 1alpha (rhIL-1alpha) in order to study the effect of glycosylation on its activities, and to develop IL-1 with less deleterious effects. The glycosylated IL-la exhibited reduced activities in vitro by 10 to 10000-fold depending upon different aspects of activities addressed. The affinity to type I and II IL-1 receptors were also reduced. In this study we examined a variety of IL-1 activities in vivo, including upregulation of serum levels of IL-6, alpha1-acid glycoprotein, NOx, corticosterone, downregulation of serum level of glucose, and recovery of peripheral white blood cells (WBCs) from myelosuppression in 5-fluorouracil-treated mice. In contrast to the biological activities in vitro, these activities in vivo were uniformly reduced by only about 10 to 20-fold compared to untreated IL-1alpha.

Animals↗
PubMed1998

Development of glycosylated human interleukin-1alpha, neoglyco IL-1alpha, by coupling with D-galactose monosaccharide: synthesis and purification.

In order to develop glycosylated cytokine, recombinant human IL-1alpha was chemically modified with galactose monosaccharide. Galactose with C9 spacer, 8-(hydrazinocarbonyl)octyl beta-D-galactopyranoside (3), was synthesized by glycosylation of C9 spacer, methyl 9-hydroxynonanoate, with acetobromogalactose, followed by deacetylation and hydrazidation. Total yield of 3 was 43.6% in three steps. Compound 3 was coupled to IL-1alpha by the acyl azide method. The glycosylated IL-1 was purified by anion-exchange chromatography, and galactose coupled to IL-1 was confirmed by R. communis lectin blotting. Based on the molecular weight, the average number of carbohydrate molecules introduced per molecule of IL-1alpha was estimated to be 9.1.

Galactose↗
PubMed2001

Study of the separation and determination of monosaccharides in soluble coffee by capillary zone electrophoresis with electrochemical detection.

A simple, fast and reliable method, based on capillary electrophoresis with electrochemical detection, for the separation and determination of six monosaccharides, namely glucose, galactose, arabinose, fructose, xylose and ribose, in soluble coffees was developed. A copper disk electrode was used as the working electrode. The optimum conditions for separation and detection were 50 mmol L-1 sodium hydroxide buffer (pH 12.7), separation voltage 5 kV and detection potential 0.65 V (vs. Ag/AgCl). The linear ranges were from 5.0 x 10(-3) to 0.5 mmol L-1 for all six sugars. All regression coefficients were > 0.99. The detection limits for all the sugars were 1.0 x 10(-3) mmol L-1. The RSD of the peak current was < 4.2% (n = 5). The proposed method was applied directly to the separation and determination of the six sugars without prior derivatization, and the assay results were satisfactory.

Journal Article↗
PubMed1969

Uptake of monosaccharides by guinea-pig cerebral-cortex slices.

By the use of 1mm-iodoacetate to inhibit glycolysis in guinea-pig cerebral tissue slices, the kinetics of the uptake of monosaccharides on transfer of tissue from 0 degrees to 37 degrees were studied. d-Ribose, d-galactose, d-mannose, l-sorbose, and d-fructose showed diffusion kinetics, whereas 2-deoxy-d-glucose, d-glucose, d-arabinose and d-xylose showed saturation kinetics.

Animals↗
PubMed1981

The binding of monosaccharide inhibitors to hen egg-white lysozyme by proton magnetic resonance at 270 MHz and analysis by ring-current calculations.

Studies of the binding of the four sugars alpha- and beta-N-acetyl-D-glucosamine (GlcNAc) and its alpha- and beta-methyl glycosides to hen egg-white lysozyme (EC 3.2.1.17) by means of high-resolution 1H n.m.r. at 270 MHz are reported. The details of the binding analyses are described in an Appendix. The results show that the sugars bind independently to more than one site in lysozyme. The apparent fully bound chemical shifts to the inhibitor proton signals show that, although the major binding modes are generally similar for the four sugars, the binding of alpha GlcNAc is distinct from that of alpha MeGlcNAc and beta MeClcNAc. The binding of beta GlcNAc is intermediate in character between these two modes. The observed shift changes of the inhibitor signals are correlated with the crystal structures of lysozyme-inhibitor complexes by the use of Johnson-Bovey ring-current calculations. Together with consideration of the chemical-shift anisotropy of the GlcNAc amide group, these suggest that GlcNAc-binding sites in solution are in subsites C and E. The calculations show also that the indole rings of Trp-62 and Trp-63 rotate towards subsite C on the binding of GlcNAc, whereas Trp-108 moves away slightly. These findings indicate a difference between the solution and tetragonal crystal forms of lysozyme-GlcNAc and lysozymes-beta MeGlcNAc complexes. In the crystal structure, binding of acetamido monosaccharides is only observed in subsite C, and binding in subsite E is prevented by crystal packing.

Acetylglucosamine↗
PubMed1992

Influence of hypertonic monosaccharide infusions on the release of plasma arginine vasopressin in normal humans.

Six healthy men were investigated to determine the osmotic efficiency of hypertonic monosaccharide solutes on the release of plasma arginine vasopressin (AVP). Twenty percent hypertonic glucose infused at 0.187 mmol/kg body weight/min. over 15 min. increases plasma osmolality but not AVP. In contrast, 20% hypertonic fructose administered identically obtains an increase in both. An initial 71% rise in AVP concentration (p less than 0.01) occurred 10 min. post-infusion accompanied by a peak in plasma osmolality and we did not expect AVP to rise by 336% (p less than 0.01) 45 minutes after infusion as plasma osmolality was returning to baseline values. The first increase in plasma AVP reflects an osmotic efficiency probably resulting from the fact that fructose does not cross the membrane of osmoreceptor cells. The mechanism of the second and unexpected increase is discussed, especially the influence of plasma insulin released as a result of fructose infusion.

Adult↗
PubMed1981

Specific monosaccharide inhibition of active sodium channels in neuroblastoma cells.

L-Fucose and D-galactose in low concentrations (0.27 or 2.7 mM) inhibited the induction of active Na+ channels in mouse and human neuroblastoma cells when the monosaccharides were added to the culture medium for 4 days with the inducing agent dimethyl sulfoxide. Active Na+ ionophores were determined by measurement of the toxin-stimulated efflux of 86Rb from the cells. At the same time, the amount of a radioactive glycoprotein (Mr 200,000), which was shown previously to be associated with neurite and membrane preparations from cells with active Na+ channels, was decreased. Cell growth and viability were not affected. The nonphysiological isomer D-fucose or the addition of D-glucose in the same concentration did not inhibit differentiation. Vibrio cholerae neuraminidase, added to the cells prior to the stimulation of 86Rb efflux by veratridine and scorpion venom, was inhibitory. The implications of these findings, which suggest a key role for glycoproteins in at least a portion of the excitability process, are discussed.

Animals↗
PubMed1985

Macrophage activation by monosaccharide precursors of Escherichia coli lipid A.

Certain Escherichia coli mutants defective in phosphatidylglycerol biosynthesis accumulate two novel glycolipids, designated X and Y. Lipid X is a diacylglucosamine 1-phosphate bearing beta-hydroxymyristoyl groups at positions 2 and 3, and lipid Y has the same structure as X, except for the additional presence of a palmitoyl moiety on the N-linked beta-hydroxymyristate. We have examined the activities of X, Y, and several related compounds as activators of macrophages. Both X and Y induce morphological changes (spreading), prostaglandin E2 synthesis, and killing of tumor cells by mouse peritoneal macrophages in vitro, properties with which lipopolysaccharide and lipid A are also endowed. Both glycolipids have similar effects on the macrophage-like mouse cell line J774.1. Selective removal from lipid X of either the ester-linked beta-hydroxymyristate at position 3 or the phosphate at position 1 abolishes activity. Our results show that the monosaccharides X and Y retain some of the properties of intact lipopolysaccharide and lipid A with respect to macrophage activation. Because the structures of X and Y are defined, our findings should facilitate the elucidation of the molecular mechanism of macrophage activation by lipid A.

Animals↗
PubMed2005

Quantification of monosaccharide anhydrides by liquid chromatography combined with mass spectrometry: application to aerosol samples from an urban and a suburban site influenced by small-scale wood burning.

Levels of the monosaccharide anhydride (MA) levoglucosan and its isomeric compounds galactosan and mannosan were quantified in the PM10 fraction (particulate matter < or = 10 microm in aerodynamic diameter) of ambient aerosols from an urban (Oslo) and a suburban (Elverum) site in Norway, both influenced by small-scale wood burning. MAs are degradation products of cellulose and hemicellulose, and levoglucosan is especially emitted in high concentrations during pyrolysis and combustion of wood, making it a potential tracer of primary particles emitted from biomass burning. MAs were quantified using a novel high-performance liquid chromatography/ high-resolution mass spectrometry-time of flight method. This approach distinguishes between the isomeric compounds of MAs and benefits from the limited sample preparation required before analysis, and no extensive derivatization step is needed. The highest concentrations of levogucosan, galactosan, and mannosan (sigmaMA) were recorded in winter because of wood burning for residential heating (sigmaMA(MAX) = 1,240 ng m(-3)). This finding was substantiated by a relatively high correlation (R2 = 0.64) between the levoglucosan concentration and decreasing ambient temperature. At the suburban site, sigmaMA accounted for 3.1% of PM10, whereas the corresponding level at the urban site was 0.6%. The mass size distribution of MAs associated with atmospheric aerosols was measured using a Berner cascade impactor. The size distribution was characterized with a single mode at 561 nm. Ninety-five percent of the mass concentration of the MAs was found to be associated with particles < 2 micro.m. A preliminary attempt to estimate the contribution of wood burning to the mass concentration of PM10 in Oslo using levoglucosan as a tracer indicates that 24% comes from wood burning. This is approximately a factor of 2 lower than estimated by the AirQUIS dispersion model.

Aerosols↗
PubMed1992

Modification of immunopharmacological activities of synthetic monosaccharide lipid A analogue, GLA60, by lysozyme.

Recent studies by our group suggested that lysozyme has a high affinity for bacterial lipopolysaccharide (LPS) of both the smooth and rough forms, and inhibits various immunomodulatory activities of LPS. GLA60 is a synthetic monosaccharide analogue of bacterial lipid A well known as having most of the activities of lipid A with very low toxicity. In this study, we characterized the interaction of lysozyme with GLA60 in comparison to that with Escherichia coli 0111 LPS (smooth form) by means of an immunopharmacological approach. Using dansylated lysozyme (DNS-LZM) as a probe, LZM was found to bind to GLA60. The mitogenic and polyclonal B-cell activating activities were significantly reduced by complex formation. However, there was no inhibitory effect on GLA60 induced production of IL-1 and TNF of macrophages. Interestingly, the activities of macrophages induced by the complex were found to be significantly higher than those induced by GLA60 itself. In contrast, the activities of 0111 LPS were significantly inhibited by LZM. Since the GLA60-LZM complex produced a turbid suspension but the 0111 LPS-LZM complex remained soluble, we consider that the activities of GLA60 alone were mediated by the common functional LPS receptor for dispersed form in both macrophages and B-lymphocytes, but activation of macrophages by the complex was mediated either by another LPS receptor not present in B-lymphocytes or through the phagocytic function of macrophages.

Adjuvants, Immunologic↗
PubMed1982

Comparison of acquired monosaccharide intolerance and acute diarrheal syndrome.

In a retrospective study, 9% of the admissions to Ben Taub General Hospital for diarrhea were found to have acquired monosaccharide intolerance (AMI). The course of AMI was compared with that of acute diarrheal syndrome (ADS). The patients with AMI were younger at the time of admission, and, although the mean birthweight and percent of prematurity were approximately the same in the two groups, the AMI patients were found to be malnourished (p less than 0.02). Data suggest that the nutritional insult had occurred between birth and admission, and that malnutrition was a contributing factor in the development of AMI.

Age Factors↗
PubMed1994

The oligosaccharide composition of human milk: temporal and individual variations in monosaccharide components.

Oligosaccharides are an important component of human milk, but little is known about variations in their composition. The aim of this study was to determine the temporal and inter-individual variations in carbohydrate composition of human milk during the first 3 months of lactation. Serial milk samples of 10 mothers (eight full-term and two preterm births) were analyzed to determine the concentration of lactose and three monosaccharide components derived from the non-lactose carbohydrate: sialic acid, N-acetylglucosamine, and fucose. In full-term milk, sialic acid and N-acetylglucosamine were found to decrease significantly (p < 0.05) from weeks 1 to 13 postnatally. On average (mean +/- SD), sialic acid decreased by 71% (from 879 +/- 157 to 256 +/- 82 mg/L; p < 0.05) and N-acetylglucosamine by 56% (from 1,459 +/- 282 to 646 +/- 214 mg/L; p < 0.05), while fucose decreased by only 35% (from 660 +/- 192 to 432 +/- 180 mg/L; p > 0.05). On average, lactose concentration increased by 17% over the same period, from 55.4 +/- 4.2 g/L in week 1 to 64.9 +/- 2.3 g/L at 3 months. Preterm milk contained higher concentrations of each component, but temporal changes were similar to those seen in full-term milk. Apart from temporal changes, there were large inter-individual differences in oligosaccharide composition: fucose varied four-fold, sialic acid threefold, and N-acetylglucosamine two-fold among women at the same stage of lactation. The changes observed may simply reflect the aging of the cells responsible for milk secretion, but they are also consistent with a programmed adaptation of the milk composition to the needs of the infant.

Acetylglucosamine↗
PubMed1994

Effect of monosaccharides during severe dry heat treatment of coagulation factor VIII concentrates.

During product development of a factor VIII concentrate (Dutch blood banks) the conversion from unsterilized to autoclaved freeze-drying buffer caused impaired product characteristics after severe dry heat treatment (80 degrees C for 72 h). Analysis of the freeze-drying buffers showed the presence of fructose and glucose in heated buffers, resulting from hydrolysis of sucrose. The detrimental effect of glucose and fructose on solubility, yield of factor VIII and color of the heat-treated product was confirmed by freeze-drying and heating products spiked with increasing levels of these monosaccharides. The effect of the use of freeze-drying buffers autoclaved with and without sucrose was examined in two other factors VIII concentrates, S(8) and Z8 (Protein Fractionation Centre, Edinburgh, UK). If sucrose was present during autoclaving of the buffer, a slightly lower yield over freeze-drying and 80 degrees C heat treatment was observed. Since glucose is present as a substrate in the medium for the host cells during cultivation of viruses, its potential effect on the 80 degrees C heated product (Dutch blood banks) was examined during the validation study of the inactivation of HIV-1 and Sindbis. The cultivation cycles for the virus inocula were simulated and residual glucose levels measured. In the supernatant medium of the host cell culture used for the propagation of Sindbis no residual glucose was found. Glucose however was found in the supernatant medium of the host cell culture for propagation of HIV-1, and therefore small molecular weight substances were removed from the actual HIV-1 inoculum by ultrafiltration.(ABSTRACT TRUNCATED AT 250 WORDS)

Buffers↗
PubMed1994

Multistep regulation mechanisms for tolerance induction to lipopolysaccharide lethality in the tumor-necrosis-factor-alpha-mediated pathway. Application of non-toxic monosaccharide lipid A analogues for elucidation of mechanisms.

Lipid A is the active principle of lipopolysaccharide (LPS). Synthetic lipid A analogues with monosaccharide backbones, GLA-60, GLA-69 and GLA-58, which exhibit potent, weak and scarce agonistic activities of LPS, respectively, induced tolerance against LPS lethality in galactosamine-(GalN)-sensitized mice while none of them were pyrogenic in rabbits. The tolerance-inducing mechanisms were investigated focusing on the regulation of tumor-necrosis-factor-alpha(TNF-alpha)-mediated lethal pathway of LPS. Induction of serum TNF-alpha in LPS-challenged mice was suppressed by prior administration of these analogues as well as LPS. Prior treatment of murine macrophages with the substances suppressed LPS-stimulated TNF-alpha production in the culture supernatant and TNF-alpha mRNA expression in the cells as well. Lethal toxicity of TNF-alpha in GalN-sensitized mice was effectively suppressed by prior treatment with LPS, GLA-60 and GLA-69 but not by GLA-58. This protective effect was suggested to be mediated by endogenous TNF-alpha, which was induced by prior treatment with the effective substances, because either neutralization of endogenously induced TNF-alpha activity with an antibody or deletion of its induction by using LPS-resistant C3H/HeJ mice reduced the protective effect, and a detectable amount of TNF-alpha was produced by stimulating macrophages with the effective substances but not with GLA-58. These results indicated that multiple regulation steps (one is prior to and the others are following TNF-alpha production) are participating in the tolerance induction by LPS and some lipid A analogues and that GLA-58 is a characteristic compound which induces the tolerance by only blocking the step prior to TNF-alpha production.

Animals↗
PubMed1975

Heterogeneity of carcinoembryonic antigen. II. Monosaccharide composition of concanavalin A-reactive and -nonreactive CEA.

Monosaccharide compositions of Con A-reactive CEA (CEA-M) and Con A-nonreactive CEA (CEA-P) separated from two different samples of CEA were analysed by gas liquid chromatography. It was revealed that all CEA subfractions possessed N-acetylglucosamine, fucose, and galactose residues. One out of 4 subfractions did not contain sialic acid and another one lacked glucose in its carbohydrate moiety. N-acetylgalactosamine was not detected in measurable amount in any of the 4 subfractions. A large amount of mannose was found in CEA-M, but only a small amount in CEA-P.

Acetylgalactosamine↗
PubMed1988

Elimination and tissue distribution of the monosaccharide lipid A precursor, lipid X, in mice and sheep.

Lipid X (2,3-diacylglucosamine 1-phosphate) is a novel monosaccharide precursor of lipid A (the active moiety of gram-negative endotoxin) and has been found to be protective against endotoxin administered to mice and sheep and against life-threatening gram-negative infections in mice. Because of the need to design optimal dosing regimens in experimental models of ovine and murine septicemia, the pharmacokinetic profile of lipid X was investigated in sheep and in two strains of mice by using 32P-labeled lipid X. In sheep, peak whole blood lipid X levels after a bolus injection of 100 micrograms of lipid X per kg were 900 ng/ml. An initial rapid distribution phase of 7.98 +/- 0.1 min was observed, followed by a prolonged elimination phase of 3.0 +/- 0.5 h; the area under the curve from time zero to infinity was 428 +/- 27 ng.h/ml. The serum half-lives of lipid X were slightly shorter than whole blood half-lives, suggesting that lipid X associates with cellular elements. Metabolites of lipid X could not be detected in serum over a 4-h period. Lipid X appears to accumulate mainly in the liver, and the tissue distribution of lipid X resembles that of lipopolysaccharide. The elimination rate of lipid X in mice was approximately four times as rapid as that seen in sheep. Lipid X pharmacokinetics in lipopolysaccharide-sensitive DBA/2J mice were virtually identical with those seen in endotoxin-resistant C3H/HeJ mice. The pharmacokinetics described here should greatly aid in the design and interpretation of animal studies investigating the therapeutic applications of lipid X in gram-negative septicemia.

Animals↗
PubMed1991

SDZ MRL 953, a novel immunostimulatory monosaccharidic lipid A analog with an improved therapeutic window in experimental sepsis.

SDZ MRL 953, a new synthetic monosaccharidic lipid A, was investigated in vitro and in vivo for immunopharmacological activities. In experimental models of microbial infections, the compound was highly protective when it was administered prophylactically either once or three times to myelosuppressed or immunocompetent mice. The 50% effective doses of SDZ MRL 953 varied with the infectious agents and the route of its administration. In all cases, the 50% effective doses were about 10(3) times higher than those obtained with endotoxin from Salmonella abortus equi. SDZ MRL 953 was, however, less toxic than lipopolysaccharide by a factor of 10(4) to greater than 7 x 10(5) times in galactosamine-sensitized mice. The compound was also an effective inducer of tolerance to endotoxin. Hence, repeated dosing with the compound induced a transient resistance (greater than or equal to 1 week) to lethal challenges with endotoxin. In vitro, the compound was devoid of intrinsic antimicrobial activity, but it moderately induced the release of cytokines from monocytes and primed human neutrophils for the enhanced production of reactive oxygen metabolites in response to a soluble stimulus. The results presented here suggest that SDZ MRL 953 may be useful in a clinical setting for enhancing resistance to infections, particularly in patients undergoing myelosuppressive chemotherapy or irradiation, and for the prophylaxis of endotoxin shock.

Animals↗