73208-61-4Relevant academic research and scientific papers
Efficient method for the elongation of the N-acetylglucosamine unit by combined use of chitinase and β-galactosidase
Shoda, Shin-ichiro,Fujita, Masaya,Lohavisavapanichi, Chakapan,Misawa, Yoshinori,Ushizaki, Koushin,Tawata, Yukiko,Kuriyama, Mao,Kohri, Michinari,Kuwata, Hideyuki,Watanabe, Takeshi
, p. 3919 - 3936 (2002)
A novel strategy for the regio- and stereoselective synthesis by two enzymatic steps of oligosaccharides having an N-acetylglucosamine unit at the nonreducing end was developed. The first step involves a chitinase-catalyzed highly selective β-N-acetyllactosamination of an oligosaccharide acceptor with a 4,5-dihydrooxazole derivative of N-acetyllactosamine as the glycosyl donor. The usage of a transition-state-analogue substrate for the chitinase under basic conditions allows the reaction to proceed only in the synthetic direction while suppressing hydrolysis of the product in aqueous media. Several chitinase mutants also catalyzed the glycosylation efficiently under neutral conditions, The second step is a regioselective cleavage of the glycosidic bond between the terminal galactose unit and the adjacent N-acetylglucosamine unit by the action of a β- galactosidase. This constitutes a very useful method to add an N-acetylglucosamine unit to the nonreducing end of chito- and cello-oligosaccharide derivatives in a regio- and stereoselective manner.
Chemoenzymatic Synthesis of Asymmetrical Multi-Antennary N-Glycans to Dissect Glycan-Mediated Interactions between Human Sperm and Oocytes
Chinoy, Zoeisha S.,Friscourt, Frédéric,Capicciotti, Chantelle J.,Chiu, Philip,Boons, Geert-Jan
supporting information, p. 7970 - 7975 (2018/05/15)
Complex N-glycans of glycoproteins of the zona pellucida (ZP) of human oocytes have been implicated in the binding of spermatozoa. The termini of these unusual bi-, tri-, and tetra-antennary N-glycans consist of the tetrasaccharide sialyl-Lewisx (SLex), which was previously identified as the minimal epitope for sperm binding. We describe here the chemoenzymatic synthesis of highly complex triantennary N-glycans derived from ZP carrying SLex moieties at the C-2 and C-2′ arm and a sialyl-Lewisx-Lewisx (SLex–Lex) residue at the C-6 antenna and two closely related analogues. The compounds were examined for their ability to inhibit the interaction of human sperm to ZP. It was found that the SLex–Lex moiety is critical for inhibitory activity, whereas the other SLex moieties exerted minimal effect. Further studies with SLex–Lex and SLex showed that the extended structure is the more potent inhibitor. In addition, trivalent SLex–Lex and SLex were prepared which showed greater inhibitory activity compared to their monovalent counterparts. Our studies show that although SLex can inhibit the binding of spermatozoa, presenting this epitope in the context of a complex N-glycan results in a loss of inhibitory potential, and in this context only SLex–Lex can make productive interactions. It is not the multivalent display of SLex on a multi-antennary glycan but the presentation of multiple SLex–Lex on the various glycosylation sites of ZP that accounts for high avidity binding.
Facile preparation of indoxyl- and nitrophenyl glycosides of lactosamine and isolactosamine
Boettcher, Stephan,Thiem, Joachim
, p. 10856 - 10861 (2014/03/21)
The synthesis of the novel indoxyl glycosides of N-acetyl-lactosamine (X-LacNAc) and N-acetyl-isolactosamine (X-LNB) is reported employing glycosyl chlorides in a facile phase transfer glycosylation, followed by mild decarboxylation and finally deacetylat
Novel Lactosamine Derivatives
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Page/Page column 13, (2009/09/28)
The present invention provides novel lactosamine derivatives and related methods suitable for the preparation, including large-scale production, of N-acetyllactosamine, lactosamine, numerous lactosamine salts and a number of lactosamine-containing oligosa
A highly convergent synthesis of an N-linked glycopeptide presenting the H-type 2 human blood group determinant
Wang, Zhi-Guang,Warren, J. David,Dudkin, Vadim Y.,Zhang, Xufang,Iserloh, Ulrich,Visser, Michael,Eckhardt, Matthias,Seeberger, Peter H.,Danishefsky, Samuel J.
, p. 4954 - 4978 (2007/10/03)
The total synthesis of an H-type blood group determinant in a model biological setting is described. The construct is comprised of a high mannose core structure with projecting lactose spacers, culminating in a two-copy presentation of the H-type blood group determinant itself. Key reactions that were used in this construction include sulfonamidohydroxylation (see 15→18) and benzoate-directed glycosylation via an activated thiophenyl donor (see 34→36). Another key strategic element involved the epimerization of an interior core glucoside to reach the β-mannoside (see 37→38) required in the ring C sugar of the high mannose core.
Reducing oligosaccharides via glycal assembly: On the remarkable stability of anomeric hydroxyl groups to global deprotection with sodium in liquid ammonia
Iserloh, Ulrich,Dudkin, Vadim,Wang, Zhi-Guang,Danishefsky, Samuel J
, p. 7027 - 7030 (2007/10/03)
Several partially benzylated 1-hydroxy sugars were rapidly deprotected by sodium/liquid ammonia. The terminal hemiketal linkage of the substrates remained intact under these conditions and does not generate ring-opened alditols. Peracetylated glucose and glucosamine derivatives were obtained in 64-79% isolated yields.
