Search results for "Aldose"
showing 6 items of 16 documents
Structural Characterization of Glycoconjugate Polystyrene in Aqueous Solution
1999
Maltopentaose-carrying polystyrene was synthesized by the homopolymerization of vinylbenzyl maltopentaose amide. Resulted amphiphilc polymacromonomer was dissolved in 0.1 M urea aqueous solution, and its structure was characterized by small-angle X-ray scattering and molecular modeling. Maltopentaose-carrying polystyrene polymacromonomer was found to be represented by a molecular bottlebrush, composed of a large helix of polystyrene backbone and maltopentaose brushes. The molecular bottlebrush seems to be distributed randomly or many even be broken once or twice in segments with no apparent intersegmental spatial correlation. A large helix of polystyrene backbone is formed by a random seque…
Glycoside synthesis via electrophile-induced activation of N-allyl carbamates
1993
Abstract O-Benzyl-, O-acyl-, N-acyl- and isopropylidene-protected glycosyl N-allylcarbamates, obtained from anomerically unprotected monosaccharides and allyl isocyanate, are activated by an electrophile-induced cyclisation and react with hydroxyl compounds to form the corresponding glycosides.
Noncovalent Saccharide Recognition by Means of a Tetrakis(bile acid)-Porphyrin Conjugate: Selectivity, Cooperation, and Stability
2010
Molecular recognition of Glu, Glc 2 -Glc 6 and Mal 3 by a tetrakis(bile acid)―porphyrin conjugate has been studied by using ESI-FTICR mass spectrometry. The bile acid conjugate was observed to form 1:1 noncovalent complexes with saccharides. The conjugate was found to have size-selectivity towards saccharides with three or more glucose residues. The Glc 3 and Glc 4 also formed kinetically the most stable complexes. The electron capture dissociation (ECD) experiments revealed that in complexation of an oligosaccharide three glucose residues interact with the bile acid conjugate, whereas additional glucose residues are susceptible to fragmentation. The ECD results also showed the significance…
Synthesis of β-d-mannosides from β-d-glucosides via an intramolecular Sn2 reaction at C-2
1992
Abstract The selective synthesis of β- d -mannosides was achieved by first synthesizing β- d -glucosides that carry a N -phenylcarbamoyl protecting group at O-3. These derivatives were transformed into the corresponding β- d -mannosides by intramolecular nucleophilic substitution with inversion of configuration at C-2, the O -triflyl group being the leaving group. Subsequent intramolecular attack of the neighboring carbamoyl group resulted in the formation of the 2,3-carbonate of the desired β d -mannoside.
Stereoselective Synthesis of β-1-O-Acyl Derivatives of Carbohydrates: An Application of the Cesium Effect.
1992
Abstract The stereoselective formation of anomerically pure 1-O-acyl derivatives of protected carbohydrates is achieved by reaction of the α-glycosyl halogenoses with cesium caboxylates.
Qualitative and quantitative evaluation of mono- and disaccharides in d-fructose, d-glucose and sucrose caramels by gas–liquid chromatography–mass sp…
1999
The monosaccharide (D-fructose, D-glucose, anhydrosugars), disaccharide (glucobioses) and pseudodisaccharide (di-D-fructose dianhydrides) content of D-fructose, D-glucose and sucrose caramels has been determined by gas-liquid chromatography-mass spectrometry (GLC-MS) of their trimethylsilyl (TMS) or TMS-oxime derivatives. The chromatographic profiles revealed significant differences in the disaccharide/pseudodisaccharide distribution depending on the caramel source: a D-fructose caramel contains prominent proportions of di-D-fructose dianhydrides, a D-glucose caramel mainly D-glucobioses, and a sucrose caramel similar proportions of both disaccharide/pseudodisaccharide series. It is notewor…