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Jegatheeswaran S, Asnani A, Forman A, Hendel JL, Moore CJ, Nejatie A, Wang A, Wang JW, Auzanneau FI. Recognition of Dimeric Lewis X by Anti-Dimeric Le x Antibody SH2. Vaccines (Basel) 2020; 8:vaccines8030538. [PMID: 32957489 PMCID: PMC7563222 DOI: 10.3390/vaccines8030538] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 09/11/2020] [Accepted: 09/14/2020] [Indexed: 11/16/2022] Open
Abstract
The carbohydrate antigen dimeric Lewis X (DimLex), which accumulates in colonic and liver adenocarcinomas, is a valuable target to develop anti-cancer therapeutics. Using the native DimLex antigen as a vaccine would elicit an autoimmune response against the Lex antigen found on normal, healthy cells. Thus, we aim to study the immunogenic potential of DimLex and search internal epitopes displayed by DimLex that remain to be recognized by anti-DimLex monoclonal antibodies (mAbs) but no longer possess epitopes recognized by anti-Lex mAbs. In this context, we attempted to map the epitope recognized by anti-DimLex mAb SH2 by titrations and competitive inhibition experiments using oligosaccharide fragments of DimLex as well as Lex analogues. We compare our results with that reported for anti-Lex mAb SH1 and anti-polymeric Lex mAbs 1G5F6 and 291-2G3-A. While SH1 recognizes an epitope localized to the non-reducing end Lex trisaccharide, SH2, 1G5F6, and 291-2G3-A have greater affinity for DimLex conjugates than for Lex conjugates. We show, however, that the Lex trisaccharide is still an important recognition element for SH2, which (like 1G5F6 and 291-2G3-A) makes contacts with all three sugar units of Lex. In contrast to mAb SH1, anti-polymeric Lex mAbs make contact with the GlcNAc acetamido group, suggesting that epitopes extend further from the non-reducing end Lex. Results with SH2 show that this epitope is only recognized when DimLex is presented by glycoconjugates. We have reported that DimLex adopts two conformations around the β-d-GlcNAc-(1→3)-d-Gal bond connecting the Lex trisaccharides. We propose that only one of these conformations is recognized by SH2 and that this conformation is favored when the hexasaccharide is presented as part of a glycoconjugate such as DimLex-bovine serum albumin (DimLex-BSA). Proper presentation of the oligosaccharide candidate via conjugation to a protein or lipid is essential for the design of an anti-cancer vaccine or immunotherapeutic based on DimLex.
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Affiliation(s)
- Sinthuja Jegatheeswaran
- Department of Chemistry, University of Guelph, Guelph, ON N1G 2W1, Canada; (S.J.); (A.A.); (A.F.); (J.L.H.); (C.J.M.); (A.N.); (A.W.); (J.-W.W.)
- Immunology Department, University of Toronto, 1 King’s College Circle, Toronto, ON M5S-1A8, Canada
| | - Ari Asnani
- Department of Chemistry, University of Guelph, Guelph, ON N1G 2W1, Canada; (S.J.); (A.A.); (A.F.); (J.L.H.); (C.J.M.); (A.N.); (A.W.); (J.-W.W.)
- Department of Chemistry, Universitas Jenderal Soedirman, Purwokerto, Jawa Tengah 53123, Indonesia
| | - Adam Forman
- Department of Chemistry, University of Guelph, Guelph, ON N1G 2W1, Canada; (S.J.); (A.A.); (A.F.); (J.L.H.); (C.J.M.); (A.N.); (A.W.); (J.-W.W.)
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, ON M5S-3H6, Canada
| | - Jenifer L. Hendel
- Department of Chemistry, University of Guelph, Guelph, ON N1G 2W1, Canada; (S.J.); (A.A.); (A.F.); (J.L.H.); (C.J.M.); (A.N.); (A.W.); (J.-W.W.)
- Research and Development, Ludger Ltd., Culham Science Centre, Abingdon, Oxfordshire OX14-3EB, UK
| | - Christopher J. Moore
- Department of Chemistry, University of Guelph, Guelph, ON N1G 2W1, Canada; (S.J.); (A.A.); (A.F.); (J.L.H.); (C.J.M.); (A.N.); (A.W.); (J.-W.W.)
- Quality Control, SteriMax Inc., 2770 Portland Dr, Oakville, ON L6H-6R4, Canada
| | - Ali Nejatie
- Department of Chemistry, University of Guelph, Guelph, ON N1G 2W1, Canada; (S.J.); (A.A.); (A.F.); (J.L.H.); (C.J.M.); (A.N.); (A.W.); (J.-W.W.)
- Department of Chemistry, Simon Fraser University, Burnaby, BC V5A1S6, Canada
| | - An Wang
- Department of Chemistry, University of Guelph, Guelph, ON N1G 2W1, Canada; (S.J.); (A.A.); (A.F.); (J.L.H.); (C.J.M.); (A.N.); (A.W.); (J.-W.W.)
- SGS-CSTC Standards Technical Services Co., Ltd. 4/F, 4th Building, 889 Yishan Road, Xuhui District, Shanghai 200233, China
| | - Jo-Wen Wang
- Department of Chemistry, University of Guelph, Guelph, ON N1G 2W1, Canada; (S.J.); (A.A.); (A.F.); (J.L.H.); (C.J.M.); (A.N.); (A.W.); (J.-W.W.)
- IQVIA, QuintilesIMS, Clinical Research, 10188 Telesis Ct #400, San Diego, CA 92121, USA
| | - France-Isabelle Auzanneau
- Department of Chemistry, University of Guelph, Guelph, ON N1G 2W1, Canada; (S.J.); (A.A.); (A.F.); (J.L.H.); (C.J.M.); (A.N.); (A.W.); (J.-W.W.)
- Correspondence:
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Jegatheeswaran S, Auzanneau FI. Recognition of Lewis X by Anti-Le x Monoclonal Antibody IG5F6. THE JOURNAL OF IMMUNOLOGY 2019; 203:3037-3044. [PMID: 31666308 DOI: 10.4049/jimmunol.1900806] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 09/22/2019] [Indexed: 11/19/2022]
Abstract
mAbs directed toward the Lewis X (Lex) determinant have been shown to display different specificities, depending on the presentation of Lex to the immune system. Of interest is the murine anti-Lex mAb IG5F6, generated against the O chain polysaccharide of Helicobacter pylori that contains polymeric Lex structures. The mAb was found to have a higher affinity for polymeric Lex over monomeric Lex In this study, we explore the recognition of monomeric Lex by IG5F6 using a panel of Lex analogues in which N-acetyl-d-glucosamine, l-fucose, or d-galactose (D-Gal) are replaced with d-glucose and/or l-rhamnose. Our studies show that all analogues were weaker inhibitors than the Lex Ag, indicating that all three residues are essential in the recognition of Lex by mAb IG5F6. We explored the involvement of 4″-OH of d-Gal in the binding with IG5F6 using a panel of 4″-modified Lex analogues. Although the 4″-OH is only involved in a weak polar interaction, we conclude that the D-Gal residue in Lex is primarily involved in aromatic stacking interactions with the Ab binding site. We compared these results to our work with mAb SH1. Although stacking interactions between D-Gal and an aromatic residue was also suggested for SH1, an H-bond involving the 4″-OH was identified that is not found in the binding of IG5F6 to Lex Thus, anti-Lex mAbs SH1 and IG5F6 bind to Lex in different manners, even though the hydrophobic patch displayed by the β-galactoside in Lex is essential in both cases for their binding to Lex.
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Nejatie A, Jegatheeswaran S, Auzanneau FI. Synthesis of LacNAcLe x- and DimLe x-BSA Conjugates and Binding to Anti-Polymeric Le xmAbs. European J Org Chem 2019. [DOI: 10.1002/ejoc.201901142] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Ali Nejatie
- Department of Chemistry; University of Guelph; 50 Stone Road East N1G2W1 Guelph ON Canada
- Department of Chemistry; Simon Fraser University; 8888 University Dr V5A1S6 Burnaby BC Canada
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Convergent synthesis of tetra- and penta-saccharide fragments of dimeric Lewis X. Carbohydr Res 2019; 482:107730. [DOI: 10.1016/j.carres.2019.06.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 06/13/2019] [Accepted: 06/14/2019] [Indexed: 11/19/2022]
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Paramasivam S, Fairbanks AJ. Rapid synthesis of N-glycan oxazolines from locust bean gum via the Lafont rearrangement. Carbohydr Res 2019; 477:11-19. [DOI: 10.1016/j.carres.2019.03.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 03/20/2019] [Indexed: 12/16/2022]
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Synthesis and anticoagulation studies of “short-armed” fucosylated chondroitin sulfate glycoclusters. Carbohydr Res 2018; 467:45-51. [DOI: 10.1016/j.carres.2018.07.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 07/27/2018] [Accepted: 07/27/2018] [Indexed: 11/20/2022]
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Zhang X, Yao W, Xu X, Sun H, Zhao J, Meng X, Wu M, Li Z. Synthesis of Fucosylated Chondroitin Sulfate Glycoclusters: A Robust Route to New Anticoagulant Agents. Chemistry 2017; 24:1694-1700. [PMID: 29131431 DOI: 10.1002/chem.201705177] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Indexed: 12/15/2022]
Affiliation(s)
- Xiao Zhang
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing, 100191, P.R. China
| | - Wang Yao
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing, 100191, P.R. China
| | - Xiaojiang Xu
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing, 100191, P.R. China
| | - Huifang Sun
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, P.R. China
| | - Jinhua Zhao
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, P.R. China
| | - Xiangbao Meng
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing, 100191, P.R. China
| | - Mingyi Wu
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, P.R. China
| | - Zhongjun Li
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing, 100191, P.R. China
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Vibhute AM, Dhaka A, Athiyarath V, Sureshan KM. A versatile glycosylation strategy via Au(iii) catalyzed activation of thioglycoside donors. Chem Sci 2016; 7:4259-4263. [PMID: 30090287 PMCID: PMC6054025 DOI: 10.1039/c6sc00633g] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Accepted: 03/04/2016] [Indexed: 12/15/2022] Open
Abstract
Among various methods of chemical glycosylations, glycosylation by activation of thioglycoside donors using a thiophilic promoter is an important strategy. Many promoters have been developed for the activation of thioglycosides. However, incompatibility with substrates having alkenes and the requirement of a stoichiometric amount of promoters, co-promoters and extreme temperatures are some of the limitations. We have developed an efficient methodology for glycosylation via the activation of thioglycoside donors using a catalytic amount of AuCl3 and without any co-promoter. The reaction is very fast, high-yielding and very facile at room temperature. The versatility of this method is evident from the facile glycosylation with both armed and disarmed donors and sterically demanding substrates (acceptors/donors) at ambient conditions, from the stability of the common protecting groups, and from the compatibility of alkene-containing substrates during the reaction.
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Affiliation(s)
- Amol M Vibhute
- School of Chemistry , Indian Institute of Science Education and Research , Thiruvananthapuram , KERALA-695016 , India . ; http://kms514.wix.com/kmsgroup
| | - Arun Dhaka
- School of Chemistry , Indian Institute of Science Education and Research , Thiruvananthapuram , KERALA-695016 , India . ; http://kms514.wix.com/kmsgroup
| | - Vignesh Athiyarath
- School of Chemistry , Indian Institute of Science Education and Research , Thiruvananthapuram , KERALA-695016 , India . ; http://kms514.wix.com/kmsgroup
| | - Kana M Sureshan
- School of Chemistry , Indian Institute of Science Education and Research , Thiruvananthapuram , KERALA-695016 , India . ; http://kms514.wix.com/kmsgroup
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Kuir D, Guillemineau M, Auzanneau FI. Aggregation of a Tetrasaccharide Acceptor Observed by NMR: Synthesis of Pentasaccharide Fragments of the Le(a)Le(x) Tumor-Associated Hexasaccharide Antigen. J Org Chem 2015; 80:5004-13. [PMID: 25860389 DOI: 10.1021/acs.joc.5b00405] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We report the synthesis of a tetrasaccharide and two pentasaccharide fragments of the Le(a)Le(x) tumor-associated carbohydrate antigen α-L-Fuc-(1→4)-[β-D-Gal-(1→3)]-β-D-GlcNAc-(1→3)-β-D-Gal-(1→4)-[α-L-Fuc-(1→3)]-β-D-GlcNAc-(1→OR). The choice of protecting groups permitted a one-step global deprotection (Na/NH3(l)). The protected chlorohexyl glycoside pentasaccharide was the precursor to the hexyl glycoside, to be used as a soluble inhibitor, and the aminohexyl glycoside analogue, to be conjugated to proteins for surface immobilization and immunization experiments. We observed that a linear tetrasaccharide that contained two N-acetylglucosamine residues and a free OH group gave two distinct sets of (1)H NMR signals when the data were acquired in deuterated chloroform. Data acquisition at variable concentrations and variable temperatures suggests that the second set of NMR signals results from aggregation of the tetrasaccharide driven by the formation of intermolecular H-bonds involving the NHAc. While the formation of intra- and intermolecular H-bonds involving N-acetylgucosamine residues has been reported in non-H-bonding solvents, this is, to our knowledge, the first time that these have lead to the appearance of two distinct sets of signals in the NMR spectra. This aggregation may explain the lack of reactivity observed when an attempt is made to glycosylate such an acceptor using non-H-bonding solvents such as dichloromethane.
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Affiliation(s)
- Deng Kuir
- Department of Chemistry, University of Guelph, Guelph, Ontario N1G 2W1, Canada
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Lian G, Zhang X, Yu B. Thioglycosides in Carbohydrate Research. Carbohydr Res 2015; 403:13-22. [DOI: 10.1016/j.carres.2014.06.009] [Citation(s) in RCA: 143] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2014] [Revised: 05/29/2014] [Accepted: 06/10/2014] [Indexed: 11/30/2022]
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Singh S, Su Z, Grossutti M, Auzanneau FI. Attempts to prepare tethered bilayer lipid membranes using synthetic thioglycolipid anchors: synthesis of 6″-thiotrisaccharide glycolipid analogues and applications. Carbohydr Res 2014; 390:50-8. [PMID: 24704433 DOI: 10.1016/j.carres.2014.03.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Revised: 03/07/2014] [Accepted: 03/08/2014] [Indexed: 11/29/2022]
Abstract
The synthesis of the three 6″-deoxy-6″-thio glycolipid analogues β-d-Gal-(1→6)-β-d-Gal-(1→4)-β-d-Glu-(1→OCH2)-[1,2,3]-triazole-1-dodecane, β-d-Gal-(1→4)-β-d-Glu-(1→4)-β-d-Glu-(1→OCH2)-[1,2,3]-triazole-1-dodecane and β-d-Gal-(1→4)-β-d-Glu-(1→4)-β-d-Glu-(1→OCH2)-[1,2,3]-triazole-1-octadecane is presented. Glycosylation at position O-4' of a propargyl cellobioside glycosyl acceptor and position O-6' of a propargyl lactoside glycosyl acceptor with a 6-deoxy-6-thio galactosyl donor gave rise to two unique trisaccharides that in turn underwent copper-catalyzed azide-alkyne cycloadditions with either 1-azidododecane or 1-azidooctadecane. The potential for each of these analogues to function as tethers of lipid bilayers to Au(111) surface was assessed by differential capacitance experiments. A monolayer of the previously described monosaccharide 1-octadecane-4-(6-thio-β-d-galacto-pyranosyloxymethyl)-[1,2,3]-triazole either self-assembled or prepared by Langmuir-Blodgett (LB) transfer was found to support an outer leaflet monolayer (DMPC/cholesterol, 70:30) deposited by Langmuir-Schaefer (LS) touch. The bilayers obtained with this monosaccharide analogue had minimum differential capacitances of 1.0 and 0.9μF/cm(2) when the inner monolayer was prepared by self-assembly and LS touch, respectively. Attempts to produce bilayers using the trisaccharides synthesized here were unsuccessful; we are attributing these unsuccessful results mostly to the high water solubility of trisaccharides combined with the relatively short length of the hydrocarbon chains used in this study.
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Affiliation(s)
- Serena Singh
- Department of Chemistry, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - Zhangfei Su
- Department of Chemistry, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - Michael Grossutti
- Department of Chemistry, University of Guelph, Guelph, Ontario N1G 2W1, Canada
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Moore CJ, Auzanneau FI. Understanding the Recognition of Lewis X by Anti-Lex Monoclonal Antibodies. J Med Chem 2013; 56:8183-90. [DOI: 10.1021/jm401304h] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Rönnols J, Pendrill R, Fontana C, Hamark C, d’Ortoli TA, Engström O, Ståhle J, Zaccheus MV, Säwén E, Hahn LE, Iqbal S, Widmalm G. Complete 1H and 13C NMR chemical shift assignments of mono- to tetrasaccharides as basis for NMR chemical shift predictions of oligosaccharides using the computer program CASPER. Carbohydr Res 2013; 380:156-66. [DOI: 10.1016/j.carres.2013.06.026] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Revised: 06/27/2013] [Accepted: 06/27/2013] [Indexed: 12/25/2022]
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Guillemineau M, Auzanneau FI. Challenging deprotection steps during the synthesis of tetra- and pentasaccharide fragments of the Le(a)Le(x) tumor-associated hexasaccharide antigen. J Org Chem 2012; 77:8864-78. [PMID: 23009725 DOI: 10.1021/jo301644w] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
We report the convergent synthesis of two novel tetrasaccharide and two novel pentasaccharide fragments of the Le(a)Le(x) TACA: the tetrasaccharides contain neither the galactose at the Le(a) nonreducing end nor the fucose at the Le(x) reducing end; the pentasaccharides only lack the galactose residue at the Le(a) nonreducing end. Two of the analogues were prepared as hexyl glycosides to be used in NMR experiments and as soluble inhibitors in binding studies and two as 6-aminohexyl glycosides to be conjugated to carrier proteins. Our strategy relied on stepwise extensions using excess monosaccharide glycosyl donors (trichloroacetimidates and thioglycosides) in sequential glycosylation reactions. The protecting groups were chosen to limit the number of deprotection steps required to obtain the final derivatives. While this strategy ensured that all glycosylation reactions proceeded in very good yields (70-84%), deprotection of the oligosaccharide intermediates was challenging. Global deprotection using Birch metal dissolving conditions did not remove the tert-butyldiphenylsilyl group, which indeed was incompatible with such reaction conditions. Attempts to remove the TBDPS with tetrabutylammonium fluoride was unsuccessful and led to a complex mixture of compounds that could not be separated. The desired hexyl and aminohexyl tetrasaccharides were finally obtained after four- and five-step deprotection sequences, respectively. Deprotection of the pentasaccharide intermediate to give the hexyl and aminohexyl analogues also led to unexpected results. Indeed, during Zemplén deacylation, a chloroacetamide chlorine atom was displaced by methoxide ions leading to the corresponding methoxyacetamide. Once the chloroacetamide was fully reduced to an acetamide the pentasaccharides were obtained in four and five steps, respectively.
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Moore CJ, Auzanneau FI. Synthesis of 4" manipulated Lewis X trisaccharide analogues. Beilstein J Org Chem 2012; 8:1134-43. [PMID: 23019441 PMCID: PMC3458731 DOI: 10.3762/bjoc.8.126] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2012] [Accepted: 06/29/2012] [Indexed: 11/25/2022] Open
Abstract
Three analogues of the Lex trisaccharide antigen (β-D-Galp(1→4)[α-L-Fucp(1→3)]-D-GlcNAcp) in which the galactosyl residue is modified at O-4 as a methyloxy, deoxychloro or deoxyfluoro, were synthesized. We first report the preparation of the modified 4-OMe, 4-Cl and 4-F trichloroacetimidate galactosyl donors and then report their use in the glycosylation of an N-acetylglucosamine glycosyl acceptor. Thus, we observed that the reactivity of these donors towards the BF3·OEt2-promoted glycosylation at O-4 of the N-acetylglucosamine glycosyl acceptors followed the ranking 4-F > 4-OAc ≈ 4-OMe > 4-Cl. The resulting disaccharides were deprotected at O-3 of the glucosamine residue and fucosylated, giving access to the desired protected Lex analogues. One-step global deprotection (Na/NH3) of the protected 4”-methoxy analogue, and two-step deprotections (removal of a p-methoxybenzyl with DDQ, then Zemplén deacylation) of the 4”-deoxychloro and 4”-deoxyfluoro protected Lex analogues gave the desired compounds in good yields.
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Affiliation(s)
- Christopher J Moore
- Department of Chemistry, University of Guelph, 50 Stone Rd. East, Guelph, Ontario, N1G 2W1, Canada
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Guillemineau M, Auzanneau FI. Matched and mismatched acceptor/donor pairs in the glycosylation of a trisaccharide diol free at O-3 of two N-acylated glucosamine residues. Carbohydr Res 2012; 357:132-8. [PMID: 22704194 DOI: 10.1016/j.carres.2012.04.020] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2012] [Revised: 04/25/2012] [Accepted: 04/30/2012] [Indexed: 10/28/2022]
Abstract
Reciprocal donor acceptor selectivity (RDAS) and double diastereodifferentiation are two concepts that have been used to explain how a glycosyl acceptor and donor may be 'matched' or 'mismatched' in glycosylation reactions. We describe here how the α-L-fucosylation and β-D-galactosylation of a trisaccharide displaying two equatorial OH groups at C-3 of N-acylated glucosamine units led to different regioselectivities or different 'matched' pairs. These results may be explained under the reciprocal donor acceptor selectivity or double diastereodifferentiation concepts. We also suggest a third explanation to these results: the presence of a benzylidene at the nonreducing end acceptor led to rigidity at this residue which resulted into a mismatched pair during β-D-galactosylation but allowed α-L-fucosylation.
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Maza S, Macchione G, Ojeda R, López-Prados J, Angulo J, de Paz JL, Nieto PM. Synthesis of amine-functionalized heparin oligosaccharides for the investigation of carbohydrate-protein interactions in microtiter plates. Org Biomol Chem 2012; 10:2146-63. [PMID: 22294265 DOI: 10.1039/c2ob06607f] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The synthesis of well-defined oligosaccharides is crucial for the establishment of structure-activity relationships for specific sequences of heparin, contributing to the understanding of the biological role of this polysaccharide. It is highly convenient that the synthetic oligosaccharides contain an orthogonal functional group that allows selective conjugation of the probes and expands their use as chemical tools in glycobiology. We present here the synthesis of a series of amine-functionalized heparin oligosaccharides using an n+2 modular approach. The conditions of the glycosylation reactions were carefully optimized to produce efficiently the desired synthetic intermediates with an N-benzyloxycarbonyl-protected aminoethyl spacer at the reducing end. The use of microwave heating greatly facilitates O- and N-sulfation steps, avoiding experimental problems associated with these reactions. The synthesized oligosaccharides were immobilized in 384-well microtiter plates and successfully probed with a heparin-binding protein, the basic fibroblast growth factor FGF-2. The use of hexadecyltrimethylammonium bromide minimized the amount of sugar required for attachment to the solid support. Using this approach we quantified heparin-protein interactions, and surface dissociation constants for the synthetic heparin derivatives were determined.
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Affiliation(s)
- Susana Maza
- Glycosystems Laboratory, Instituto de Investigaciones Químicas, Centro de Investigaciones Científicas Isla de La Cartuja, CSIC and Universidad de Sevilla, Américo Vespucio, 49, 41092 Sevilla, Spain
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Hendel JL, Auzanneau FI. Convergent Preparation of DimLex Hexasaccharide Analogues. European J Org Chem 2011. [DOI: 10.1002/ejoc.201101342] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Daragics K, Fügedi P. Synthesis of glycosaminoglycan oligosaccharides. Part 5: Synthesis of a putative heparan sulfate tetrasaccharide antigen involved in prion diseases. Tetrahedron 2010. [DOI: 10.1016/j.tet.2010.08.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Wang A, Auzanneau FI. Synthesis of LeaLex oligosaccharide fragments and efficient one-step deprotection. Carbohydr Res 2010; 345:1216-21. [DOI: 10.1016/j.carres.2010.03.038] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2010] [Revised: 03/25/2010] [Accepted: 03/28/2010] [Indexed: 11/27/2022]
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Wang A, Hendel J, Auzanneau FI. Convergent syntheses of Le analogues. Beilstein J Org Chem 2010; 6:17. [PMID: 20485599 PMCID: PMC2870943 DOI: 10.3762/bjoc.6.17] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2009] [Accepted: 01/21/2010] [Indexed: 02/02/2023] Open
Abstract
The synthesis of three Lex derivatives from one common protected trisaccharide is reported. These analogues will be used respectively for competitive binding experiments, conjugation to carrier proteins and immobilization on gold. An N-acetylglucosamine monosaccharide acceptor was first glycosylated at O-4 with a galactosyl imidate. This coupling was performed at 40 °C under excess of BF3·OEt2 activation and proceeded best if the acceptor carried a 6-chlorohexyl rather than a 6-azidohexyl aglycon. The 6-chlorohexyl disaccharide was then converted to an acceptor and submitted to fucosylation yielding the corresponding protected 6-chlorohexyl Lex trisaccharide. This protected trisaccharide was used as a precursor to the 6-azidohexyl, 6-acetylthiohexyl and 6-benzylthiohexyl trisaccharide analogues which were obtained in excellent yields (70–95%). In turn, we describe the deprotection of these intermediates in one single step using dissolving metal conditions. Under these conditions, the 6-chlorohexyl and 6-azidohexyl intermediates led respectively to the n-hexyl and 6-aminohexyl trisaccharide targets. Unexpectedly, the 6-acetylthiohexyl analogue underwent desulfurization and gave the n-hexyl glycoside product, whereas the 6-benzylthiohexyl analogue gave the desired disulfide trisaccharide dimer. This study constitutes a particularly efficient and convergent preparation of these three Lex analogues.
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Affiliation(s)
- An Wang
- Department of Chemistry, University of Guelph, Guelph, Ontario, N1G 2W1, Canada
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Hendel JL, Wang JW, Jackson TA, Hardmeier K, De Los Santos R, Auzanneau FI. How the Substituent at O-3 of N-Acetylglucosamine Impacts Glycosylation at O-4: A Comparative Study. J Org Chem 2009; 74:8321-31. [DOI: 10.1021/jo901616p] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jenifer L. Hendel
- Department of Chemistry, University of Guelph, Guelph, Ontario, N1G 2W1 Canada
| | - Jo-Wen Wang
- Department of Chemistry, University of Guelph, Guelph, Ontario, N1G 2W1 Canada
| | - Trudy A. Jackson
- Department of Chemistry, University of Guelph, Guelph, Ontario, N1G 2W1 Canada
| | - Karolyn Hardmeier
- Department of Chemistry, University of Guelph, Guelph, Ontario, N1G 2W1 Canada
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