73724-48-8Relevant articles and documents
Use of remote acyl groups for stereoselective 1,2-: Cis -glycosylation with fluorinated glucosazide thiodonors
?ervenková ??astná, Lucie,Cu?ínová, Petra,Dra?ínsky, Martin,Hamala, Vojtěch,Karban, Jind?ich,Kurfi?t, Martin
supporting information, p. 5427 - 5434 (2020/08/03)
Fluorinated glycans are valuable probes for studying carbohydrate-protein interactions at the atomic level. Glucosamine is a ubiquitous component of glycans, and the stereoselective synthesis of α-linked fluorinated glucosamine is a challenge associated with the chemical synthesis of fluorinated glycans. We found that introducing a 6-O-acyl protecting group onto 3-fluoro and 4-fluoro glucosazide thiodonors endowed them with moderate α-selectivity in the glycosylation of carbohydrate acceptors, which was further improved by adjusting the acceptor reactivity via O-benzoylation. Excellent stereoselectivity was achieved for 3,6-di-O-acyl-4-fluoro analogues. The glycosylation of threonine-derived acceptors enabled the stereoselective synthesis of the protected fluorinated analogue of α-GlcNAc-O-Thr, a moiety abundant in cell-surface O-glycans of the protozoan parasite Trypanosoma cruzi. DFT calculations supported the involvement of transient cationic species which resulted from the stabilization of the oxocarbenium ion through O-6 acyl group participation. This journal is
A Synthetic MUC1 Glycopeptide Bearing βGalNAc-Thr as a Tn Antigen Isomer Induces the Production of Antibodies against Tumor Cells
Leiria Campo, Vanessa,Riul, Thalita B.,Oliveira Bortot, Leandro,Martins-Teixeira, Maristela B.,Fiori Marchiori, Marcelo,Iaccarino, Emanuela,Ruvo, Menotti,Dias-Baruffi, Marcelo,Carvalho, Ivone
, p. 527 - 538 (2017/03/22)
This study presents the synthesis of the novel protected O-glycosylated amino acid derivatives 1 and 2, containing βGalNAc-SerOBn and βGalNAc-ThrOBn units, respectively, as mimetics of the natural Tn antigen (αGalNAc-Ser/Thr), along with the solid-phase assembly of the glycopeptides NHAcSer-Ala-Pro-Asp-Thr[αGalNAc]-Arg-Pro-Ala-Pro-Gly-BSA (3-BSA) and NHAcSer-Ala-Pro-Asp-Thr[βGalNAc]-Arg-Pro-Ala-Pro-Gly-BSA (4-BSA), bearing αGalNAc-Thr or βGalNAc-Thr units, respectively, as mimetics of MUC1 tumor mucin glycoproteins. According to ELISA tests, immunizations of mice with βGalNAc-glycopeptide 4-BSA induced higher sera titers (1:320 000) than immunizations with αGalNAc-glycopeptide 3-BSA (1:40 000). Likewise, flow cytometry assays showed higher capacity of the obtained anti-glycopeptide 4-BSA antibodies to recognize MCF-7 tumor cells. Cross-recognition between immunopurified anti-βGalNAc antibodies and αGalNAc-glycopeptide and vice versa was also verified. Lastly, molecular dynamics simulations and surface plasmon resonance (SPR) showed that βGalNAc-glycopeptide 4 can interact with a model antitumor monoclonal antibody (SM3). Taken together, these data highlight the improved immunogenicity of the unnatural glycopeptide 4-BSA, bearing βGalNAc-Thr as Tn antigen isomer.
α-Selective glycosylation affords mucin-related GalNAc amino acids and diketopiperazines active on Trypanosoma cruzi
Martins-Teixeira, Maristela B.,Campo, Vanessa L.,Biondo, Monica,Sesti-Costa, Renata,Carneiro, Zumira A.,Silva, Jo?o S.,Carvalho, Ivone
, p. 1978 - 1987 (2013/05/08)
This work addresses the synthesis and biological evaluation of glycosyl diketopiperazines (DKPs) cyclo[Asp-(αGalNAc)Ser] 3 and cyclo[Asp-(αGalNAc)Thr] 4 for the development of novel anti-trypanosomal agents and Trypanosoma cruzi trans-sialidase (TcTS) inhibitors. The target compounds were synthetized by coupling reactions between glycosyl amino acids αGalNAc-Ser 7 or αGalNAc-Thr 8 and the amino acid (O-tBu)-Asp 17, followed by one-pot deprotection-cyclisation reaction in the presence of 20% piperidine in DMF. The protected glycosyl amino acid intermediates 7 and 8 were, in turn, obtained by α-selective, HgBr2-catalysed glycosylation reactions of Fmoc-Ser/Thr benzyl esters 12/14 with αGalN3Cl 11, being, subsequently, fully deprotected for comparative biological assays. The DKPs 3 and 4 showed relevant anti-trypanosomal effects (IC50 282-124 μM), whereas glycosyl amino acids 1 and 2 showed better TcTS inhibition (57-79%) than the corresponding DKPs (13-25%).
Influence of steric parameters on the synthesis of tetramates from α-amino-β-alkoxy-esters and Ph3PCCO
Loke, Inga,Park, Natja,Kempf, Karl,Jagusch, Carsten,Schobert, Rainer,Laschat, Sabine
, p. 697 - 704 (2012/01/05)
α-Aminoesters react with Ph3PCCO in a domino addition-Wittig cyclization sequence affording enantiomerically pure tetramates. In the case of β-oxo functionalized α-aminoesters, e.g., esters of serine, threonine or β-hydroxyornithine the yields of this reaction depend heavily on the bulkiness of the β-OR group and on the configuration of β-carbon atom C-3. Smaller residues and 2R/3R-configured aminoesters give better yields. The alkoxycarbonyl group of the ester moiety and the residue on the N-atom are less important. These findings can be accounted for by assuming an early puckered transition state for the intramolecular ring-closing Wittig reaction. The addition of sub-stoichiometric amounts of benzoic acid or N-hydroxysuccinimide (for acid-sensitive compounds) is advantageous in some cases as it accelerates the formation of the intermediate amide ylides.
Design, synthesis and the effect of 1,2,3-triazole sialylmimetic neoglycoconjugates on Trypanosoma cruzi and its cell surface trans-sialidase
Campo, Vanessa L.,Sesti-Costa, Renata,Carneiro, Zumira A.,Silva, Jo?o S.,Schenkman, Sergio,Carvalho, Ivone
body text, p. 145 - 156 (2012/02/15)
This work describes the synthesis of a series of sialylmimetic neoglycoconjugates represented by 1,4-disubstituted 1,2,3-triazole-sialic acid derivatives containing galactose modified at either C-1 or C-6 positions, glucose or gulose at C-3 position, and by the amino acid derivative 1,2,3-triazole fused threonine-3-O-galactose as potential TcTS inhibitors and anti-trypanosomal agents. This series was obtained by Cu(I)-catalysed azide-alkyne cycloaddition reaction ('click chemistry') between the azido-functionalized sugars 1-N3-Gal (commercial), 6-N 3-Gal, 3-N3-Glc and 3-N3-Gul with the corresponding alkyne-based 2-propynyl-sialic acid, as well as by click chemistry reaction between the amino acid N3-ThrOBn with 3-O-propynyl-GalOMe. The 1,2,3-triazole linked sialic acid-6-O-galactose and the sialic acid-galactopyranoside showed high Trypanosoma cruzi trans-sialidase (TcTS) inhibitory activity at 1.0 mM (approx. 90%), whilst only the former displayed relevant trypanocidal activity (IC50 260 μM). These results highlight the 1,2,3-triazole linked sialic acid-6-O-galactose as a prototype for further design of new neoglycoconjugates against Chagas' disease.
Chemical and chemoenzymatic synthesis of glycosyl-amino acids and glycopeptides related to Trypanosoma cruzi mucins
Campo, Vanessa Leiria,Carvalho, Ivone,Allman, Sarah,Davis, Benjamin G.,Field, Robert A.
, p. 2645 - 2657 (2008/03/12)
This study describes the synthesis of the α- and β-linked N-acetyllactosamine (Galp-β-1,4-GlcNAc; LacNAc) glycosides of threonine (LacNAc-Thr). LacNAc-α-Thr was prepared by direct chemical coupling of a 2-azido-2-deoxy-lactose disaccharide donor to a suitable partially protected threonine unit. In contrast, stepwise chemical generation of β-linked N-acetylglucosamine followed by enzymatic galactosylation to give LacNAc-β-Thr proved effective, whereas use of a 2-azido-2-deoxy-lactose donor in acetonitrile failed to give the desired β-linked disaccharyl glycoside. This study illustrates that it is possible to overcome the inherent stereoselection for 1,2-trans chemical glycosylation with a GlcNAc donor, and that the well-established preference of bovine β-1,4-galactosyltransferase for β-linked acceptor substrates can also be overcome. Using this knowledge, short glycopeptide fragments based on T. cruzi mucin sequences, Thr-Thr-[LacNAcThr]-Thr-Thr-Gly, were synthesised. All LacNAc-based compounds outlined were shown to serve as acceptor substrates for sialylation by T. cruzi trans-sialidase. The Royal Society of Chemistry.
Synthesis of mannosyl and oligomannosyl threonine building blocks found on the mycobacterium tuberculosis 45 kDa MPT 32 glycoprotein
Varon, Daniel,Lioy, Eduardo,Patarroyo, Manuel E.,Schratt, Xaver,Unverzagt, Carlo
, p. 161 - 165 (2007/10/03)
Mycobacterium tuberculosis secretes a 45 kDa glycoprotein (MPT 32) carrying mannosylated threonine residues. A general strategy was developed to couple peracetylated mannose, α-(1,2)-linked mannobiose or mannotriose to Fmoc-threonine-benzyl ester. Activation of mannosyl acetates or fluorides by borontrifluoride etherate gave the desired Fmoc-glycosyl amino acid building blocks in good yields. The synthesis leads to stable compounds and can easily be scaled up.
Solid-phase synthesis of O-linked glycopeptide analogues of enkephalin
Mitchell,Pratt,Hruby,Polt
, p. 2327 - 2342 (2007/10/03)
The synthesis of 18 N-α-FMOC-amino acid glycosides for solid-phase glycopeptide assembly is reported. The glycosides were synthesized either from the corresponding O'Donnell Schiff bases or from N-α-FMOC-amino protected serine or threonine and the appropriate glycosyl bromide using Hanessian's modification of the Koenigs-Knorr reaction. Reaction rates of D-glycosyl bromides (e.g., acetobromoglucose) with the L- and D-forms of serine and threonine are distinctly different and can be rationalized in terms of the steric interactions within the two types of diastereomeric transition states for the D/L and D/D reactant pairs. The N-α-FMOC-protected glycosides [monosaccharides Xyl, Glc, Gal, Man, GlcNAc, and GalNAc; disaccharides Gal-β(1-4)-Glc (lactose), Glc-β(1-4)-Glc (cellobiose), and Gal-α(1-6)-Glc (melibiose)] were incorporated into 22 enkephalin glycopeptide analogues. These peptide opiates bearing the pharmacophore H-Tyr-c[DCys-Gly-Phe-DCys]- were designed to probe the significance of the glycoside moiety and the carbohydrate-peptide linkage region in blood-brain barrier (BBB) transport, opiate receptor binding, and analgesia.
Chemical Synthesis of Some Mono- and Digalactosyl O-Glycopeptides
Lacombe, J. M.,Pavia, A. A.
, p. 2557 - 2563 (2007/10/02)
Chemical synthesis of several O-glycopeptides containing O-galactosylthreonine are reported.Two different approaches have been investigated to determine the strategy best adapted to the synthesis of any desired O-glycopeptide.Glycosylation of an adequatel
