Synthesis Of Tetrasaccharide Research Articles

Facile synthesis of tetrasaccharide aided by fluorous chemistry toward a dengue virus vaccine

We report the synthesis of a tetrasaccharide with side chain using a light-fluorous-tagged glycosyl donor through the double glycosylation and gradient fluorous solid-phase extraction by adding a little of DCM to improve the solubility for retention for the first time. This convergent method has high efficacy by saving much time and solvent.

Sequential enzymatic glycosyltransfer reactions on a microfluidic device: Synthesis of a glycosaminoglycan linkage region tetrasaccharide

A microfluidic chip carrying three reaction chambers was designed and constructed to examine sequential multiple enzymatic reactions. The synthesis of oligosaccharides in living cells is carried out in the Golgi apparatus where multiple enzymes such as glycosidase and glycosyltransferases act on a variety of substrates to generate glycoconjugates that include glycolipids and glycoproteins. The regulatory mechanism of the process however remains unknown. A microchip-based analysis platform may provide a valuable tool with which to address the issue by mimicking the Golgi function. We thus examined 3 sequential glycosyltransfer reactions on a chip, and succeeded in the synthesis of a tetrasaccharide using immobilized enzymes. Also, the kinetic parameters for a recently identified glycosyltransferase, proteoglycan GalT-I, were obtained for the first time.

First Synthesis of Heparan Sulfate Tetrasaccharides Containing both N‐Acetylated and N‐Unsubstituted Glucosamine—Search for Putative 10E4 Epitopes

A methodology allowing the differentiation of azido groups in protected oligosaccharides was optimized. It allowed the first synthesis of tetrasaccharides 1 and 2 containing both N-acetylated and N-unsubstituted glucosamine, as well as glucuronic and/or iduronic acid residues. These tetrasaccharides were then examined for their ability to interact with 10E4, an antibody recognizing early lesions in the brain of scrapie prion-infected mice.

Synthesis of the Glc 3Man N-glycan tetrasaccharide by iterative allyl IAD

The synthesis of the tetrasaccharide α- d-Glc p-(1→2)-α- d-Glc p-(1→3)-α- d-Glc p-(1→3)-α- d-Man p-OMe, corresponding to the terminal tetrasaccharide portion of the glucose terminated arm of the N-glycan tetradecasaccharide, was achieved with complete stereocontrol by the use of iterative allyl protecting group mediated intramolecular aglycon delivery (allyl IAD) demonstrating the utility of intramolecular glycosylation for the stereocontrolled construction of multiple glycosidic linkages during the synthesis of an oligosaccharide.

Synthesis of Tetrasaccharide Repeating Unit of the O‐Antigen from Enterohemorrhagic Escherichia coli O157 in the form of its 2‐(trimethylsilyl)ethyl Glycoside

Two α‐linked disaccharide derivatives, ethyl 3,4,6‐tri‐O‐acetyl‐2‐azido‐2‐deoxy‐α‐D‐galactopyranosyl‐(1→2)‐4‐azido‐3‐O‐benzyl‐4,6‐dideoxy‐1‐thio‐α‐D‐mannopyranoside (10) and 2‐(trimethylsilyl)ethyl 3‐O‐acetyl‐4‐O‐benzoyl‐2‐O‐benzyl‐α‐L‐fucopyranosyl‐(1→4)‐2,3‐di‐O‐benzyl‐6‐O‐tert‐butyldiphenylsilyl‐β‐D‐glucopyranoside (16), were prepared from appropriate monosaccharide synthons. The disaccharide 16 was deacetylated and debenzoylated to afford the acceptor 17, which was allowed to react with the donor 10 to afford a tetrasaccharide derivative 18. This tetrasaccharide was transformed in three steps into 21, the desired repeating unit of the antigen from enterohemorrhagic E. coli type O157.

Synthesis and biological evaluation of oligosaccharides related to the molecule signals in plant defence and the Rhizobium-legume symbiosis

The synthesis of tetrasaccharides related to the chitinoligosaccharides involved in plant defence and Rhizobium-legume symbiosis is reported. One and two central GlcNAc residues of the chitin backbone have been replaced by Glc units. A biological evaluation using Catharanthus roseaus assay indicates that the replacement of the two central units produces a total loss of activity. However, the replacement of the GlcNAc moiety close to the reducing end by Glc in the chitin tetramer, does not reduce its activity.

Synthesis of tetrasaccharides as possible metastatic inhibitors

The synthesis is reported of the possible metastatic inhibitors — methyl β-d-galactopyranosyl-(1 → 4)-(2-acetamido-2-deoxy- α- d-glucopyranosyl)-(1 → 6)- β-d-galactopyranosyl-(1 → 4)- β-d-glucopyranoside ( 11) and methyl β-d- galactopyranosyl-(1 → 4)-(2-acetamido-2-deoxy- β-d- glucopyranosyl)-(1 → 6)- β-d-galactopyranosyl-(1 → 4)- β- d-glucopyranoside ( 14) — by procedures for regio- and stereo- selective coupling, reduction of azido groups, N-acetylation, and O-deacetylation.

Synthesis of tetrasaccharide containing glycopeptides related to bacterial cell wall starting from free tetrasaccharide by the pentafluorophenyl ester method

The free tetrasaccharide GlcNAc-MurNAc-GlcNAc-MurNAc was converted into the tetrasaccharide bis-pentafluorophenyl ester I by treatment with bis(pentafluorophenyl)carbonate. Reaction of I with suitably protected peptides afforded [GlcNAc-MurNAc-L-Ala-D-Glu(OBzl)2]2 (II) and [GlcNAc-MurNAc-L-Ala-D-iGln-L-Lys(Z)-OBzl]2 (IV). Catalytic hydrogenolysis of compound II and IV yielded (GlcNAc-MurNAc-L-Ala-D-Glu)2 (III) and (GlcNAc-MurNAc-L-Ala-D-iGln-L-Lys)2 (V), respectively. [GlcNAc-MurNAc-L-Ala-D-iGln-L-Lys(St)2]2 (VI) was prepared from compound V by reaction with stearic acid N-hydroxysuccinimide ester.

Synthesis of Tetrasaccharides Related to the O-Specific Determinants of Salmonella Serogroups A, B and D1.

Synthesis of Tetrasaccharides Related to the O-Specific Determinants of Salmonella Serogroups A, B and D1.