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| 2. |
- Buskas, T., et al.
(author)
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Efficient synthesis of polylactosamine structures through regioselective glycosylations
- 2001
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In: Journal of carbohydrate chemistry. - 0732-8303 .- 1532-2327. ; 20:7-8, s. 569-583
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Journal article (peer-reviewed)abstract
- Di-, tri-and tetramers of ß-(1?3)-linked N-acetyllactosamine residues have been synthesised as their methyl glycosides, to be used in ITC binding studies to various galectins. The synthetic strategy involves two types of regioselective glycosylations: couplings of a galactosyl donor to 3,4-diol N-tetrachlorophthalimido glucose acceptors to give the lactosamine monomer building blocks, and subsequent formation of the oligomers through consecutive couplings of lactosamine donors to 2',3',4'-lactosamine acceptors, with high selectivity for the desired products.
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| 3. |
- Buskas, T, et al.
(author)
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Synthesis of oligosaccharides designed to form micelles, corresponding to structures found in ovarian cyst fluid
- 2000
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In: Journal of carbohydrate chemistry. - 0732-8303 .- 1532-2327. ; 19:1, s. 25-51
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Journal article (peer-reviewed)abstract
- The syntheses of alpha-D-GlcpNAc-(1-->4)-beta-D-Galp-(1-->4)-beta-D-GlcNAc-(1-->O)-(CH2)(15)CH3 (1) and fragments thereof, corresponding to structures found in human ovarian cyst fluid, are described. Silver triflate promoted coupling of 3.4,6-tri-O-acetyl-2-azido-2-deoxy-beta-D-glucopyranosyl bromide (12) and galactose acceptor (11) gave a disaccharide donor (13), which was readily transformed into the corresponding bromo-derivative 18. For the synthesis of disaccharide beta-D-Galp-(1-->4)-D-GlcNAc, several differently protected glucosamine accepters were prepared. It was found that cetyl alcohol needed to be introduced after the formation of the P-galactoside bond. Glycosylation of pent-4-enyl 3,6-di-O-benzyl-2-deoxy-2-tetrachlorophthalimido-beta-D-glucopyranoside (30) with (3,4,6-tri-O-acetyl-2-azido-2-deoxy-alpha-D-glucopyranosyl)-(1-->4)-2,3,6-tri-O-benzoyl-alpha-D-galactopyranosyl bromide (18) by use of silver triflate as promoter gave the desired trisaccharide 31. Finally 31 was transformed via coupling to the long alkyl chain aglycon and deprotection into the title compound 1.
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| 4. |
- Desmet, Tom, et al.
(author)
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Synthesis and Evaluation of 2-Deoxy-2-amino-beta-cellobiosides as Cellulase Inhibitors
- 2010
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In: Journal of carbohydrate chemistry. - : Informa UK Limited. - 0732-8303 .- 1532-2327. ; 29:4, s. 164-180
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Journal article (peer-reviewed)abstract
- The cellulase mixture of Hypocrea jecorina (formerly Trichoderma reesei) contains a variety of exo- and endoglucanases that belong to different structural families. As such, these enzymes form an interesting model system to study the enzyme-ligand interactions in glycoside hydrolases. The nucleophilic carboxylate of retaining -glycosidases is believed to form a hydrogen bond with the 2-hydroxyl group of their substrate. Consequently, replacing this hydroxyl group with an amino group should result in a stronger electrostatic interaction and thus an increased affinity for the ligand. In this study, several modified cellobiosides were synthesized and evaluated as cellulase inhibitors. The introduction of an amino group was found to have an unpredictable effect on the inhibitory power of the ligands. However, the enzymes display a very high affinity for the corresponding 2-azido compounds, precursors in the synthetic route. The new ligand m-iodobenzyl 2-deoxy-2-azido--cellobioside even is the strongest inhibitor of cellobiohydrolase I known to date (KI= 1 M).
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| 5. |
- Hederos, Markus, et al.
(author)
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Efficient routes to ethyl-2-deoxy-2-phthalimido-1-β-D-thio-galactosamine derivatives via epimerization of the corresponding glucosamine compounds
- 2005
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In: Journal of carbohydrate chemistry. - 0732-8303 .- 1532-2327. ; 24:3, s. 297-320
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Journal article (peer-reviewed)abstract
- Short synthetic routes to protected ethyl 2-deoxy-2-phthalimido-1-β-D- thio-galactosamine derivatives via epimerization of the corresponding glucosamine compounds are described. Starting from D-glucosamine hydrochloride, the epimerizations were performed by displacement of presynthesized triflates with nitrite anions and by an oxidation/reduction route. The latter method involved Moffatt oxidation to the corresponding 4-ketohexoses and subsequent reduction using sodium borohydride/ tetrabutylammonium borohydride, zinc borohydride, or lithium tri-sec-butyl borohydride in THF. The displacement route was found to be the preferred method for epimerization of 3-O-acyl (benzoyl) derivatives. For glucosamine compounds with 3-O-etheral- (allyl or benzyl) and 6-O-benzyl protecting groups, the oxidation/reduction route was the most convenient procedure to achieve corresponding galactosamine compounds. The produced galactosamine derivatives will be useful building blocks in the synthesis of antifreeze glycoproteins substances and analogues thereof.
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| 6. |
- Lahmann, Martina, 1963, et al.
(author)
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Synthesis of urine drug metabolites: Glucuronosyl esters of carboxymefloquine, indoprofen, (S)-naproxen, and desmethyl (S)-naproxen
- 2004
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In: Journal of Carbohydrate Chemistry. - : Taylor & Francis Group. - 0732-8303 .- 1532-2327. ; 23:2-3, s. 123-132
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Journal article (peer-reviewed)abstract
- A general procedure for the synthesis of 1-O-acyl-beta-D-glucuronic acids using the benzyl 1-O-trichloroacetimidoyl-2,3,4-tri-O-benzyl-D-glucopyranuronate 6 as donor is exemplified by the synthesis of the urine metabolites of (S)-naproxen, desmethyl (S)-naproxen, indoprofen, and carboxymefloquine. The key intermediate benzyl 2,3,4-tri-O-benzyl-D-glucopyranuronate 5 is easily accessible in four steps (29%) from the peracetylated beta-D-glucuronic acid 1.
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| 7. |
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| 8. |
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| 9. |
- Peterson, Kristoffer, et al.
(author)
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Aryl Sulfonates in Inversions at Secondary Carbohydrate Hydroxyl Groups: A New and Improved Route Toward 3-Azido-3-deoxy-beta-D-galactopyranosides
- 2015
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In: Journal of Carbohydrate Chemistry. - : Informa UK Limited. - 0732-8303 .- 1532-2327. ; 34:8, s. 490-499
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Journal article (peer-reviewed)abstract
- A method of using benzenesulfonates and imidazylates as leaving groups at the secondary C3 galactopyranose carbon, instead of the commonly used less stable triflate leaving group, to facilitate scale-up and improve reproducibility is disclosed. The benzenesulfonates and imidazylates were proven to be significantly more stable than the corresponding triflates and the method was used to devise an improved route toward 3-azido-3-deoxy-beta-D-galactopyranosides.
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| 10. |
- Sundgren, Andreas, 1975, et al.
(author)
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Block synthesis of Streptococcus pneumoniae type 14 capsular polysaccharide structures
- 2005
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In: Journal of Carbohydrate Chemistry. - 0732-8303 .- 1532-2327. ; 24:4-6, s. 379-391
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Journal article (peer-reviewed)abstract
- Synthesis of a thioglycoside tetrasaccharide block, beta-D-Galp-(1 -> 4)-beta-DGlcp-(1 -> 6)-[beta-D-Galp-(1 -> 4)]-beta-D-GlcNPhthp-(1 -> SEt, corresponding to the repeating unit of Streptococcus pneumoniae serotype 14 CPS is described. Coupling of this block with a spacer followed by removal of an isopropylidene acetal yielded an acceptor, which was elongated with the donor block to give a protected dimer of the repeating unit. Iteration of this methodology yielded the trimer. Deprotection then produced an octa and a dode-casaccharide derivative ready for conjugation to proteins to afford immunoactive glycoconjugates.
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