ABSTRACT
A scalable synthetic procedure to high quality 2'-fucosyllactose, the most abundant oligosaccharide in human breast milk, has been designed and validated in kilogram scale. The synthetic route has been developed to suit industrial environment and contains only a single chromatographic purification step.
Subject(s)
Trisaccharides/chemical synthesis , Chemistry Techniques, Synthetic , Glycosylation , Trisaccharides/chemistryABSTRACT
A new test was elaborated to identify a new set of orthogonal protecting groups. With the developed method eight different protecting groups were tested under various deprotection conditions and the complex reaction mixtures were analysed by HPLC. The developed method allows for quick identification of orthogonality using simple model structures.
Subject(s)
Biological Products/chemistry , Chromatography, High Pressure Liquid/methods , Glucosides/chemistry , Biological Products/chemical synthesis , Glucosides/chemical synthesis , Molecular ConformationABSTRACT
The synthesis of nine new, bifunctional organocatalysts having carbohydrate scaffolds has been accomplished. In these catalysts both of the catalytic amino and thiourea functions are directly attached to a carbohydrate core. The activities of the newly prepared catalysts were tested in a Michael addition.
Subject(s)
Glucose/chemistry , Amines/chemistry , Catalysis , Drug Design , Thiourea/chemistryABSTRACT
Two different approaches were employed to study solid phase random glycosylations to obtain oligosaccharide libraries. In approach I, Wang resin esters were attached to the acceptors structures. Following their glycosylation and resin cleavage, the peracetylated components of the oligosaccharide libraries were characterized. In approach II, polymer-linked donor components could be employed and processed correspondingly. Approach I proved to be superior regarding yield and versatility of products and also allowed the formation of higher oligomers.
Subject(s)
Combinatorial Chemistry Techniques , Glycosylation , Oligosaccharides/chemical synthesis , Carbohydrate Conformation , Carbohydrate Sequence , Magnetic Resonance Spectroscopy , Oligosaccharides/chemistryABSTRACT
A comparative study on solution-phase and solid-phase oligosaccharide synthesis was performed. A 16-member library containing all regioisomers of Glc-Glc, Glc-Gal, Gal-Glc, and Gal-Gal disaccharides was synthesized both in solution and on solid phase. The various reaction conditions for different approaches and corresponding yields are analyzed and discussed.
Subject(s)
Disaccharides/chemistry , Disaccharides/chemical synthesis , Carbohydrate Sequence , Glycosylation , Magnetic Resonance Spectroscopy , Molecular Sequence DataABSTRACT
Four novel disaccharides of glycosylated 1,5-anhydro-D-ketoses have been prepared: 1,5-anhydro-4-O-beta-D-glucopyranosyl-D-fructose, 1,5-anhydro-4-O-beta-D-galactopyranosyl-D-fructose, 1,5-anhydro-4-O-beta-D-glucopyranosyl-D-tagatose, and 1,5-anhydro-4-O-beta-D-galactopyranosyl-D-tagatose. The common intermediate, 1,5-anhydro-2,3-O-isopropylidene-beta-D-fructopyranose, was prepared from D-fructose and was converted into the D-tagatose derivative by oxidation followed by stereoselective reduction to the 4-epimer. The anhydroketoses thus prepared were glycosylated and deprotected to give the disaccharides.
Subject(s)
Disaccharides/chemistry , Disaccharides/chemical synthesis , Fructose/analogs & derivatives , Fructose/chemical synthesis , Sugar Alcohols/chemistry , Fructose/chemistry , Glycosylation , Magnetic Resonance Spectroscopy , Molecular StructureABSTRACT
Trifluoromethanesulfonic acid anhydride (triflic acid anhydride) transforms the bicyclic thiazolidinlactam 1 a into the crystalline elimination product 2, in which all four secondary hydroxyl groups of 1 a are differently functionalized. Compound 2 can then add nucleophiles with high chemo- and stereoselectivity. Altogether, the four secondary hydroxyl groups of D-glucuronic acid are selectively transformed without the need for any O-protecting groups. Minimizing the number of O-protecting groups is a prerequisite for the use of sugar scaffolds in molecular libraries. The hapalosin analogues 15, 16, 19, and 22 outline the strategy towards O-diversified glucose derivatives.
Subject(s)
Glucuronic Acid/chemistry , Hydroxyl Radical/chemistry , Bridged Bicyclo Compounds/chemistry , Crystallography, X-Ray , Depsipeptides/chemical synthesis , Depsipeptides/chemistry , Indicators and Reagents , Lactams/chemical synthesis , Lactams/chemistry , Lactones/chemical synthesis , Lactones/chemistry , Mesylates , Models, Molecular , Molecular ConformationABSTRACT
The chemical synthesis of alpha-L-Fucp-(1 --> 3)-beta-D-GalpNAc-(1 --> 4)-beta-D-GlcpNAc-(1 --> 3)-alpha-D-GalpO(CH2)5NH2, beta-D-GalpNAc-(1 --> 4)-[alpha-L-Fucp-(1 --> 3)-]beta-D-GlcpNAc-(1 --> 3)-alpha-D-GalpO(CH2)5NH2, and alpha-L-Fucp-(1 --> 3)-beta-D-GalpNAc-(1 --> 4)-[alpha-L-Fucp-(1 --> 3)-]beta-D-GlcpNAc-(1 --> 3)-alpha-D-GalpO(CH2)5NH2 is described. These structures represent fucosylated oligosaccharide fragments of the glycocalyx glycan of the cercarial stage of the parasite Schistosoma mansoni, and in protein-conjugated form they are potential diagnostics in the search for antibodies raised against the glycan in the serum of infected humans.