Synthesis of 2-Amino-2-deoxy-β-D-galactopyranosyl-(1→4)-2-amino-2-deoxy-β-D-galactopyranosides: Using Various 2-Deoxy-2-phthalimido-D-galactopyranosyl Donors and Acceptors

2004 ◽  
Vol 69 (10) ◽  
pp. 1914-1938 ◽  
Author(s):  
Jan Veselý ◽  
Miroslav Ledvina ◽  
Jindřich Jindřich ◽  
Tomáš Trnka ◽  
David Šaman
Keyword(s):  
Systematic Study ◽  
Glycosyl Donor ◽  
Derivatives Of ◽  
Glycosyl Donors

A systematic study is presented of the efficiency of the most common glycosylation methods using standard 2-deoxy-2-phthalimidogalactopyranosyl donors ethyl 4-O-acetyl-3,6-di-O- benzyl-2-deoxy-2-phthalimido-1-thio-β-D-galactopyranoside (3a), 4-O-Acetyl-3,6-di-O-benzyl- 2-deoxy-2-phthalimido-β-D-galactopyranosyl bromide (4), 4-O-acetyl-3,6-di-O-benzyl-2-deoxy-2-phthalimido-β-D-galactopyranosyl fluoride (5b), O-(4-O-acetyl-3,6-di-O-benzyl-2-deoxy-2-phthalimido-β-D-galactopyranosyl) trichloroacetimidate (7) and ethyl 3,6-di-O-benzyl-2-deoxy-2-phthalimido-1-thio-β-D-galactopyranoside (8), pent-4-enyl 3,6-di-O-benzyl- and 3-O-allyl-6-O-benzyl-2-deoxy-2-phthalimido-β-D-galactopyranoside (10a) and (10b) and pent-4-enyl 3,6-di-O-benzyl-2-deoxy-2-phthalimido-4-O-(trimethylsilyl)-β-D-galactopyranoside (11) as glycosyl acceptors in the synthesis of 2-amino-2-deoxy-β-D-galactopyranosyl-(1→4)-2-amino-2-deoxy-β-D-galactopyranosides 12, 16a and 17a. It was found that due to a low reactivity of the axial OH(4) group of glycosyl acceptors, disaccharides 16b and 17b with α(1→4) bond were also formed. The unexpected intermolecular migration of ethylsufanyl group from the reducing end of glycosyl acceptor 8 the reducing end of the activated form of glycosyl donor 4 in the glycosylation step to give ethylsulfanyl derivative 3a was proved. For preparation of the glycosyl donors and glycosyl acceptors with galacto configuration an approach based on epimerization of 4-O-mesyl derivatives of appropriate synthons with gluco configuration 2a and 2b was employed.

Synthesis of N-substituted Five and Six-membered Iminocyclitols-bearing Sugar Moiety: Strategy Toward the Synthesis of Pseudodisaccharide

2018 ◽  
Vol 15 (6) ◽  
pp. 853-862
Author(s):  
Nader Al Bujuq ◽  
Manuel Angulo
Keyword(s):  
Molecular Modeling ◽  
Biologically Active Compounds ◽  
Biologically Active ◽  
Efficient Synthesis ◽  
Active Compounds ◽  
Sugar Moiety ◽  
Stereoselective Method ◽  
Glycosyl Donor ◽  
Derivatives Of ◽  
Glycosyl Donors

Aim and Objective: The efficient synthesis of disaccharide containing iminosugar moiety has a considerable interest in the field of glycoscience. In the present work, we describe a novel and applicable method for synthesis of five and six-membered N-substituted iminosugars attached with sugar moiety (pseudodisaccharides). Materials and Methods: The method of the glycosylation was based on the coupling of iminosugar thioglycoside (glycosyl donors) with partially protected sugars (glycosyl acceptors) in the presence of DMTST as a promoter. 2D COSY, HMQC, HMBC experiments were carried out to assist in NMR signal assignments. The pseudoanomeric configuration was established through NOE experiments and molecular modeling calculations. Results: Two classes of pseudodisaccharides were successfully obtained, five and six-membered N-substituted iminosugars glycosides. The six-membered pseudodisaccharides compounds were produced selectively with only β anomer. The corresponding five-membered pseudodisaccharides were achieved with moderate stereoselectivity. The yields obtained were good. These derivatives of iminocyclitols are thought to be precedents to develop various pseudodisaccharides, novel biologically active compounds, and new functional molecules. Conclusion: According to the results, utilizing iminosugar thioglycosides (1 and 2) as a glycosyl donor in glycosylation reactions is an efficient and highly stereoselective method to prepare (five- and six-membered) iminocyclitols (iminosugars) that bear a sugar moiety. The results will add to the synthesis of the iminosugars derivatives and contribute to make our approach among the few methods able to synthesize iminosugar glycosides.

Synthesis of the tetrasaccharide repeat unit of the O-antigen polysaccharide from Escherichia coli O77 employing the 2′-carboxybenzyl glycoside

2006 ◽  
Vol 84 (4) ◽  
pp. 506-515 ◽  
Author(s):  
Bo Ram Lee ◽  
Joo Mi Jeon ◽  
Jae Hyuk Jung ◽  
Heung Bae Jeon ◽  
Kwan Soo Kim
Keyword(s):  
Escherichia Coli ◽  
Repeat Unit ◽  
O Antigen ◽  
Glycosyl Donor ◽  
Glycosyl Donors

The synthesis of the suitably protected form (1) of the tetrasaccharide repeat unit, →2)-α-D-Manp-(1→2)-β-D-Manp-(1→3)-α-D-GlcpNAc-(1→6)-α-D-Manp-(1→ (A), of the O-antigen polysaccharide of the lipopolysaccharide from Escherichia coli O77 has been accomplished by latent–active glycosylation employing the 2′-carboxybenzyl (CB) gly coside method. In addition to previously used latent glycosyl donors, 2′-(benzyloxycarbonyl)benzyl (BCB) glycosides, new latent glycosyl donors, 2'-(allyloxycarbonyl)benzyl (ACB) glycosides, have been introduced as a direct precursor for the active CB glycosides. We also demonstrate that 4,6-O-benzylidene-2-azido-2-deoxy-α-D-mannopyranoside (7) has been readily prepared from D-glucosamine in good yield.Key words: Escherichia coli O77, glycosylation, 2′-carboxybenzyl (CB) glycosides, 2′-(allyloxycarbonyl)benzyl (ACB) glycosides, glycosyl donor.

N-Thiodiglycoloyl derivatives of glucosamine as glycosyl donors

2000 ◽  
Vol 41 (5) ◽  
pp. 629-632 ◽  
Author(s):  
Julio C Castro-Palomino ◽  
Richard R Schmidt
Keyword(s):  
Derivatives Of ◽  
Glycosyl Donors

Investigations into the Chemistry of Some 1,6-Epithio and 1,6-Episeleno ß-D-Glucopyranoses

2000 ◽  
Vol 53 (5) ◽  
pp. 389 ◽  
Author(s):  
Brian W. Skelton ◽  
Robert V. Stick ◽  
D. Matthew G. Tilbrook ◽  
Allan H. White ◽  
Spencer J. Williams
Keyword(s):  
Crystal Structures ◽  
Oxidation Reactions ◽  
Derivatives Of ◽  
Glycosyl Donors

Derivatives of 1,6-dideoxy-1,6-epithio-β-D-glucopyranose have been shown to undergo oxidation reactions to afford the corresponding sulfoxides and sulfones. The sulfoxides participate in Pummerer reactions to afford the corresponding α-acetoxy sulfides which were then oxidized further. None of the sulfoxides, sulfones or α-acetoxy sulfides prepared were particularly efficient glycosyl donors. Also presented are crystal structures of 1,6-dideoxy-1,6-epithio-β-D-glucopyranose S,S-dioxide and 1,6-dideoxy-1,6-episeleno-β-D-glucopyranose, interesting analogues of 1,6-anhydro-β-D-glucopyranose.

C-Glycosylation of Oxygenated Naphthols with 3-Dimethylamino-2,3,6-trideoxy-L-arabino-hexopyranose and 3-Azido-2,3,6-trideoxy-D-arabino-hexopyranose

2003 ◽  
Vol 56 (8) ◽  
pp. 787 ◽  
Author(s):  
Margaret A. Brimble ◽  
Roger M. Davey ◽  
Malcolm D. McLeod ◽  
Maureen Murphy
Keyword(s):  
Lewis Acid ◽  
Boron Trifluoride ◽  
Electronic Effects ◽  
Effective Coupling ◽  
Boron Trifluoride Diethyl Etherate ◽  
Glycosyl Donor ◽  
Aryl Glycosides ◽  
Coupling Partner ◽  
Fine Tune ◽  
Glycosyl Donors

In connection with studies directed towards the synthesis of the pyranonaphthoquinone antibiotic medermycin, C-aryl glycosides were prepared by C-glycosylation of naphthols with glycosyl donors. Boron trifluoride diethyl etherate proved to be a suitable Lewis acid to promote the C-glycosylation, and use of the azido glycosyl donor proved more successful than using the dimethylamino glycosyl donor. 5-Hydroxy-1,4-dimethoxynaphthalene underwent facile C-glycosylation with two particular glycosyl donors, whereas 3-bromo-5-hydroxy-1,4-dimethoxynaphthalene was not an effective coupling partner with the same glycosyl donors. These studies indicate that subtle steric and electronic effects need to be considered in order to fine-tune C-glycosylations when using highly functionalized glycosyl donors.

scholarly journals Koenigs-Knorr Glycosylation with Neuraminic Acid Derivatives

2010 ◽  
Vol 2010 ◽  
pp. 1-8 ◽  
Author(s):  
Galina Pazynina ◽  
Vitaly Nasonov ◽  
Ivan Belyanchikov ◽  
Reinchard Brossmer ◽  
Maxim Maisel ◽  
...  
Keyword(s):  
Methyl Ester ◽  
Acid Methyl Ester ◽  
Neuraminic Acid ◽  
Carbohydrate Binding ◽  
Acetylneuraminic Acid ◽  
Acid Methyl ◽  
Glycosyl Donor ◽  
Carbohydrate Binding Proteins ◽  
Derivatives Of

Earlier we reported a convenient and efficient method of preparing α2-6 sialooligosaccharides in conditions of Koenigs-Knorr reaction. The use of Ag2CO3 allowed carrying out α2-6 sialylation of galacto-4,6-diol of mono- and disaccharides with chloride of acetylated N-acetylneuraminic acid methyl ester as glycosyl donor. In this study we applied this approach to other derivatives of neuraminic acid, namely, Neu5Gc, 9-deoxy-9-NAc-Neu5Ac, Neu5Acα2-8Neu5Ac, and Neu5Acα2-8Neu5Acα2-8Neu5Ac as glycosyl donors; eight compounds were synthesized: Neu5Gcα-O(CH2)3NH2 (8), Neu5Gcα2-6Galβ1-4GlcNAcβ-O(CH2)3NH2 (10), 9-deoxy-9-NAc-Neu5Ac-O(CH2)3NH2 (15), 9-deoxy-9-NAc-Neu5Acα2-6Galβ1-4GlcNAcβ-O(CH2)3NH2 (17), Neu5Acα2-8Neu5Acα-O(CH2)3NH2(23) Neu5Acα2-8Neu5Acα-OCH3 (24), Neu5Acα2-8Neu5Acα-OCH2(p-C6H4)NHCOCH2NH2 (25), and Neu5Acα2-8Neu5Acα2-8Neu5Acα-O(CH2)3NH2 (32). These sialosides were used for characterization of siglecs and other carbohydrate-binding proteins.

scholarly journals Novel prenyl-linked benzophenone substrate analogues of mycobacterial mannosyltransferases

2004 ◽  
Vol 382 (3) ◽  
pp. 905-912 ◽  
Author(s):  
Mark R. GUY ◽  
Petr A. ILLARIONOV ◽  
Sudagar S. GURCHA ◽  
Lynn G. DOVER ◽  
Kevin J. C. GIBSON ◽  
...  
Keyword(s):  
Active Site ◽  
Covalent Modification ◽  
Biosynthetic Pathways ◽  
Specific Inhibition ◽  
Enzyme Active Site ◽  
Substrate Analogues ◽  
Glycosyl Donor ◽  
Derivatives Of ◽  
Polyprenyl Phosphates

PPM (polyprenol monophosphomannose) has been shown to act as a glycosyl donor in the biosynthesis of the Man (mannose)-rich mycobacterial lipoglycans LM (lipomannan) and LAM (lipoarabinomannan). The Mycobacterium tuberculosis PPM synthase (Mt-Ppm1) catalyses the transfer of Man from GDP-Man to polyprenyl phosphates. The resulting PPM then serves as a donor of Man residues leading to the formation of an α(1→6)LM intermediate through a PPM-dependent α(1→6)mannosyltransferase. In the present study, we prepared a series of ten novel prenyl-related photoactivatable probes based on benzophenone with lipophilic spacers replacing several internal isoprene units. These probes were excellent substrates for the recombinant PPM synthase Mt-Ppm1/D2 and, on photoactivation, several inhibited its activity in vitro. The protection of the PPM synthase activity by a ‘natural’ C75 polyprenyl acceptor during phototreatment is consistent with probe-mediated photoinhibition occurring via specific covalent modification of the enzyme active site. In addition, the unique mannosylated derivatives of the photoreactive probes were all donors of Man residues, through a PPM-dependent mycobacterial α(1→6)mannosyltransferase, to a synthetic Manp(1→6)-Manp-O-C10:1 disaccharide acceptor (where Manp stands for mannopyranose). Photoactivation of probe 7 led to striking-specific inhibition of the M. smegmatis α(1→6)mannosyltransferase. The present study represents the first application of photoreactive probes to the study of mycobacterial glycosyltransferases involved in LM and LAM biosynthesis. These preliminary findings suggest that the probes will prove useful in investigating the polyprenyl-dependent steps of the complex biosynthetic pathways to the mycobacterial lipoglycans, aiding in the identification of novel glycosyltransferases.

ChemInform Abstract: N-Thiodiglycoloyl Derivatives of Glucosamine as Glycosyl Donors.

ChemInform ◽  
2010 ◽  
Vol 31 (19) ◽  
pp. no-no
Author(s):  
Julio C. Castro-Palomino ◽  
Richard R. Schmidt
Keyword(s):  
Derivatives Of ◽  
Glycosyl Donors
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