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Abstract: An efficient synthesis of sialyllactosamine (SiaLacNAc) clusters using carbosilanes as core scaffolds has been accomplished by means of chemical and enzymatic approaches. N-Acetyl-d-glucosamine (GlcNAc) clusters having O-glycosidic linkage or S-glycosidic linkage were chemically synthesized from known intermediates in high yields. The GlcNAc clusters were first used as substrates for β1,4 galactosyl transferase using UDP-galactose (UDP-Gal) as a sugar source to provide corresponding N-acetyllactosamine clusters. Further sugar elongation of the LacNAc clusters was demonstrated using α2,3 sialyl transferase and CMP-neuraminic acid (CMP-NANA) to yield the corresponding SiaLacNAc clusters. [ABSTRACT FROM AUTHOR]

Abstract: Synthetic construction of fucosyl chitobiose [GlcNAcβ1→4(Fucα1→3)GlcNAc] as an allergy-associated carbohydrate epitope was accomplished from three building blocks. The trisaccharidic unit was further transformed into a carbohydrate monomer and polymerization of the glycomonomer proceeded smoothly to provide a series of glycopolymers having various carbohydrate densities. In addition to the organic syntheses, biological evaluations of the glycomonomer and the polymers were carried out and sugar-clustering effects were observed. [Copyright &y& Elsevier]

Abstract: Synthetic construction of a Lex determinant was accomplished via slightly modified Gabriel amine synthesis from three building blocks. Further transformations followed by polymerization of the Lex derivative gave a glycopolymer having trisaccharidic units as pendant-type epitopes. [Copyright &y& Elsevier]

Abstract: An efficient separation between fully acetylated thiosialoside methyl esters and fully acetylated Neu5Ac2en methyl esters was accomplished by means of a size-exclusion chromatography (SEC) method. Purity determinations and structural elucidation of the isolated compounds were performed by a combination of elemental analyses and spectroscopic analyses, including IR, 1H, and 13C NMR, and mass spectroscopic analyses. [Copyright &y& Elsevier]

Convenient and useful construction of a trisaccharide moiety of globotriaosyl ceramide was performed by means of modified Ogawa’s protocol. In order to evaluate an efficiency of new class of glycopolymers, further chemical transformations of the trisaccharide were accomplished to afford a globotriaosyl carbohydrate monomer, and homopolymerization of the monomer by a general radical polymerization protocol gave a high-density glycopolymer in 84.3% yield after usual work-up procedures. In addition to the homopolymer, a copolymer composed of carbohydrate units and acrylamide units was also synthesized by the radical polymerization in 96.7% yield. [Copyright &y& Elsevier]

A novel anomeric β-thioacetate of an N-acetyllactosamine derivative was efficiently synthesized in high yield from the known 2-azido glycosyl chloride using thioacetic acid as a convenient reagent. The synthesis involved not only an SN2 replacement of the chloride by a carbothiolate anion but also a reductive acetamidation of the azide group. Applications of the thioacetate for glycosidation were demonstrated to provide both O- and S-glycosides in high yields. Furthermore, both intermediates gave a new class of glycoclusters that included thioglycosidic linkages. [Copyright &y& Elsevier]