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Dhakal B, Mandhapati A, Park S, Sun L, Chaikof EL. Insights Derived from the Synthesis of a Complex Core 2 Glycan. J Org Chem 2024; 89:11641-11658. [PMID: 39087956 DOI: 10.1021/acs.joc.4c01345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/02/2024]
Abstract
We describe the synthesis of a benzoyl-based C2-O-sLeX-Thr-COOH building block devoid of any aglycone transfer or orthoester-formed byproducts. The absence of byproducts was achieved in the course of both [1 + 1] glycosylation reactions with thiophenol aglycone containing galactose acceptors, as well as a [2 + 2] glycosylation in the presence of a p-methoxy benzyl containing glucosamine-fucose disaccharide. We also report an efficient [2 + 1 + 1] synthesis of a peracetylated sLeX en route to a peracetylated C2-O-sLeX-Thr-COOH. While the total synthesis of the latter compound was recently reported by a related route, the divergent [2 + 1 + 1] synthesis provided good reaction yields for each step of the sequence, establishing this scheme as an alternate approach to the peracetylated C2-O-sLeX-Thr-COOH. Importantly, the current report details the role of a variety of hydroxy-protecting groups, including acetyl, benzoyl, p-methoxy benzyl, and naphthylmethyl that may be considered in designing a route to this complex Core 2 glycan. While we have previously described the use of more glycosylation-friendly naphthylmethyl protecting groups, the current synthesis used p-methoxy benzyl protecting groups with excellent reaction yields, demonstrating the feasibility of applying this side reaction-prone protecting group for this challenging synthesis.
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Affiliation(s)
- Bibek Dhakal
- Department of Surgery, Harvard Medical School, Beth Israel Deaconess Medical Center, Boston, Massachusetts 02215, United States
| | - Appi Mandhapati
- Department of Surgery, Harvard Medical School, Beth Israel Deaconess Medical Center, Boston, Massachusetts 02215, United States
| | - Simon Park
- Department of Surgery, Harvard Medical School, Beth Israel Deaconess Medical Center, Boston, Massachusetts 02215, United States
| | - Lijun Sun
- Department of Surgery, Harvard Medical School, Beth Israel Deaconess Medical Center, Boston, Massachusetts 02215, United States
- Harvard Medical School Center for Glycoscience, Harvard Medical School, Boston, Massachusetts 02215, United States
| | - Elliot L Chaikof
- Department of Surgery, Harvard Medical School, Beth Israel Deaconess Medical Center, Boston, Massachusetts 02215, United States
- Harvard Medical School Center for Glycoscience, Harvard Medical School, Boston, Massachusetts 02215, United States
- Wyss Institute of Biologically Inspired Engineering, Harvard University, Boston, Massachusetts 02115, United States
- Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
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2
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Gagnon SML, Legg MSG, Sindhuwinata N, Letts JA, Johal AR, Schuman B, Borisova SN, Palcic MM, Peters T, Evans SV. High-resolution crystal structures and STD NMR mapping of human ABO(H) blood group glycosyltransferases in complex with trisaccharide reaction products suggest a molecular basis for product release. Glycobiology 2018; 27:966-977. [PMID: 28575295 DOI: 10.1093/glycob/cwx053] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Accepted: 05/31/2017] [Indexed: 11/12/2022] Open
Abstract
The human ABO(H) blood group A- and B-synthesizing glycosyltransferases GTA and GTB have been structurally characterized to high resolution in complex with their respective trisaccharide antigen products. These findings are particularly timely and relevant given the dearth of glycosyltransferase structures collected in complex with their saccharide reaction products. GTA and GTB utilize the same acceptor substrates, oligosaccharides terminating with α-l-Fucp-(1→2)-β-d-Galp-OR (where R is a glycolipid or glycoprotein), but use distinct UDP donor sugars, UDP-N-acetylgalactosamine and UDP-galactose, to generate the blood group A (α-l-Fucp-(1→2)[α-d-GalNAcp-(1→3)]-β-d-Galp-OR) and blood group B (α-l-Fucp-(1→2)[α-d-Galp-(1→3)]-β-d-Galp-OR) determinant structures, respectively. Structures of GTA and GTB in complex with their respective trisaccharide products reveal a conflict between the transferred sugar monosaccharide and the β-phosphate of the UDP donor. Mapping of the binding epitopes by saturation transfer difference NMR measurements yielded data consistent with the X-ray structural results. Taken together these data suggest a mechanism of product release where monosaccharide transfer to the H-antigen acceptor induces active site disorder and ejection of the UDP leaving group prior to trisaccharide egress.
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Affiliation(s)
- Susannah M L Gagnon
- Department of Biochemistry & Microbiology, University of Victoria, Victoria, British Columbia, Canada V8W 3P6
| | - Max S G Legg
- Department of Biochemistry & Microbiology, University of Victoria, Victoria, British Columbia, Canada V8W 3P6
| | - Nora Sindhuwinata
- Institute of Chemistry, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany
| | - James A Letts
- Department of Biochemistry & Microbiology, University of Victoria, Victoria, British Columbia, Canada V8W 3P6
| | - Asha R Johal
- Department of Biochemistry & Microbiology, University of Victoria, Victoria, British Columbia, Canada V8W 3P6
| | - Brock Schuman
- Department of Biochemistry & Microbiology, University of Victoria, Victoria, British Columbia, Canada V8W 3P6
| | - Svetlana N Borisova
- Department of Biochemistry & Microbiology, University of Victoria, Victoria, British Columbia, Canada V8W 3P6
| | - Monica M Palcic
- Department of Biochemistry & Microbiology, University of Victoria, Victoria, British Columbia, Canada V8W 3P6.,Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2
| | - Thomas Peters
- Institute of Chemistry, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany
| | - Stephen V Evans
- Department of Biochemistry & Microbiology, University of Victoria, Victoria, British Columbia, Canada V8W 3P6
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3
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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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4
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Kinnaert C, Daugaard M, Nami F, Clausen MH. Chemical Synthesis of Oligosaccharides Related to the Cell Walls of Plants and Algae. Chem Rev 2017; 117:11337-11405. [DOI: 10.1021/acs.chemrev.7b00162] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Christine Kinnaert
- Center for Nanomedicine and
Theranostics, Department of Chemistry, Technical University of Denmark, Kemitorvet, Building 207, 2800 Kongens Lyngby, Denmark
| | - Mathilde Daugaard
- Center for Nanomedicine and
Theranostics, Department of Chemistry, Technical University of Denmark, Kemitorvet, Building 207, 2800 Kongens Lyngby, Denmark
| | - Faranak Nami
- Center for Nanomedicine and
Theranostics, Department of Chemistry, Technical University of Denmark, Kemitorvet, Building 207, 2800 Kongens Lyngby, Denmark
| | - Mads H. Clausen
- Center for Nanomedicine and
Theranostics, Department of Chemistry, Technical University of Denmark, Kemitorvet, Building 207, 2800 Kongens Lyngby, Denmark
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5
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A novel O -fucosylation strategy preactivated by ( p -Tol) 2 SO/Tf 2 O and its application for the synthesis of Lewis blood group antigen Lewis a. Tetrahedron Lett 2017. [DOI: 10.1016/j.tetlet.2017.04.056] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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6
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Ghosh T, Santra A, Misra AK. Convergent synthesis of a hexasaccharide corresponding to the cell wall O-antigen of Escherichia coli O41. RSC Adv 2014. [DOI: 10.1039/c3ra45493b] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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7
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Tsvetkov YE, Burg-Roderfeld M, Loers G, Ardá A, Sukhova EV, Khatuntseva EA, Grachev AA, Chizhov AO, Siebert HC, Schachner M, Jiménez-Barbero J, Nifantiev NE. Synthesis and molecular recognition studies of the HNK-1 trisaccharide and related oligosaccharides. The specificity of monoclonal anti-HNK-1 antibodies as assessed by surface plasmon resonance and STD NMR. J Am Chem Soc 2011; 134:426-35. [PMID: 22087768 DOI: 10.1021/ja2083015] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The human natural killer cell carbohydrate, HNK-1, plays function-conducive roles in peripheral nerve regeneration and synaptic plasticity. It is also the target of autoantibodies in polyneuropathies. It is thus important to synthesize structurally related HNK-1 carbohydrates for optimizing its function-conducive roles, and for diagnosis and neutralization of autoantibodies in the fatal Guillain-Barré syndrome. As a first step toward these goals, we have synthesized several HNK-1 carbohydrate derivatives to assess the specificity of monoclonal HNK-1 antibodies from rodents: 2-aminoethyl glycosides of selectively O-sulfated trisaccharide corresponding to the HNK-1 antigen, its nonsulfated analogue, and modified structures containing 3-O-fucosyl or 6-O-sulfo substituents in the N-acetylglucosamine residues. These were converted, together with several related oligosaccharides, into biotin-tagged probes to analyze the precise carbohydrate specificity of two anti-HNK-1 antibodies by surface plasmon resonance that revealed a crucial role of the glucuronic acid in antibody binding. The contribution of the different oligosaccharide moieties in the interaction was shown by saturation transfer difference (STD) NMR of the complex consisting of the HNK-1 pentasaccharide and the HNK-1 412 antibody.
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Affiliation(s)
- Yury E Tsvetkov
- Laboratory of Glycoconjugate Chemistry, N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky prospect 47, 119991 Moscow, Russia
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8
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Application and limitations of the methyl imidate protection strategy of N-acetylglucosamine for glycosylations at O-4: synthesis of Lewis A and Lewis X trisaccharide analogues. Carbohydr Res 2008; 343:2914-23. [PMID: 18801477 DOI: 10.1016/j.carres.2008.08.025] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2008] [Revised: 08/21/2008] [Accepted: 08/25/2008] [Indexed: 11/22/2022]
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9
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Glycosyltransferase-catalyzed synthesis of bioactive oligosaccharides. Biotechnol Adv 2008; 26:436-56. [PMID: 18565714 DOI: 10.1016/j.biotechadv.2008.05.001] [Citation(s) in RCA: 124] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2008] [Revised: 02/14/2008] [Accepted: 05/09/2008] [Indexed: 02/07/2023]
Abstract
Mammalian cell surfaces are all covered with bioactive oligosaccharides which play an important role in molecular recognition events such as immune recognition, cell-cell communication and initiation of microbial pathogenesis. Consequently, bioactive oligosaccharides have been recognized as a medicinally relevant class of biomolecules for which the interest is growing. For the preparation of complex and highly pure oligosaccharides, methods based on the application of glycosyltransferases are currently recognized as being the most effective. The present paper reviews the potential of glycosyltransferases as synthetic tools in oligosaccharide synthesis. Reaction mechanisms and selected characteristics of these enzymes are described in relation to the stereochemistry of the transfer reaction and the requirements of sugar nucleotide donors. For the application of glycosyltransferases, accepted substrate profiles are summarized and the whole-cell approach versus isolated enzyme methodology is compared. Sialyltransferase-catalyzed syntheses of gangliosides and other sialylated oligosaccharides are described in more detail in view of the prominent role of these compounds in biological recognition.
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10
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Brown JR, Crawford BE, Esko JD. Glycan antagonists and inhibitors: a fount for drug discovery. Crit Rev Biochem Mol Biol 2008; 42:481-515. [PMID: 18066955 DOI: 10.1080/10409230701751611] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Glycans, the carbohydrate chains of glycoproteins, proteoglycans, and glycolipids, represent a relatively unexploited area for drug development compared with other macromolecules. This review describes the major classes of glycans synthesized by animal cells, their mode of assembly, and available inhibitors for blocking their biosynthesis and function. Many of these agents have proven useful for studying the biological activities of glycans in isolated cells, during embryological development, and in physiology. Some are being used to develop drugs for treating metabolic disorders, cancer, and infection, suggesting that glycans are excellent targets for future drug development.
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11
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Exploring the Substrate Specificity of a Mycobacterial Polyprenol Monophosphomannose-Dependent α-(1→6)-Mannosyltransferase. Chembiochem 2008; 9:267-78. [DOI: 10.1002/cbic.200700391] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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12
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Qian X, Sujino K, Palcic MM, Ratcliffe RM. GLYCOSYLTRANSFERASES IN OLIGOSACCHARIDE SYNTHESIS. J Carbohydr Chem 2007. [DOI: 10.1081/car-120016492] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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13
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Cociorva OM, Gurcha SS, Besra GS, Lowary TL. Oligosaccharides as inhibitors of mycobacterial arabinosyltransferases. Di- and trisaccharides containing C-3 modified arabinofuranosyl residues. Bioorg Med Chem 2005; 13:1369-79. [PMID: 15670944 DOI: 10.1016/j.bmc.2004.11.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2004] [Revised: 10/29/2004] [Accepted: 11/04/2004] [Indexed: 11/20/2022]
Abstract
The assembly of the arabinan portions of cell wall polysaccharides in mycobacteria involves a family of arabinosyltransferases (AraT's) that promote the polymerization of decaprenolphosphoarabinose. Mycobacterial viability depends upon the ability of the organism to synthesize an intact arabinan and thus compounds that inhibit these AraT's are both useful biochemical tools as well as potential lead compounds for new anti-tuberculosis agents. We describe here the preparation of oligosaccharide fragments of mycobacterial arabinan that contain arabinofuranosyl residues modified at C-3 by the replacement of the hydroxyl group with an amino, azido or methoxy functionality. Subsequent testing of these oligosaccharides as inhibitors of mycobacterial AraT's revealed that all inhibited the enzymes, but to varying degrees. In further studies, each compound was shown to have only low activity as an inhibitor of mycobacterial growth.
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Affiliation(s)
- Oana M Cociorva
- Department of Chemistry, The Ohio State University, 100 West 18th Avenue, Columbus, OH 43210, USA
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14
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Subramaniam V, Gurcha SS, Besra GS, Lowary TL. Modified mannose disaccharides as substrates and inhibitors of a polyprenol monophosphomannose-dependent α-(1→6)-mannosyltransferase involved in mycobacterial lipoarabinomannan biosynthesis. Bioorg Med Chem 2005; 13:1083-94. [PMID: 15670916 DOI: 10.1016/j.bmc.2004.11.027] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2004] [Revised: 11/15/2004] [Accepted: 11/15/2004] [Indexed: 10/26/2022]
Abstract
A panel of alpha-(1-->6)-linked mannose disaccharides (5-8) in which the 2'-OH group has been replaced, independently, by deoxy, fluoro, amino, and methoxy functionalities has been synthesized. Evaluation of these compounds as potential substrates or inhibitors of a polyprenol monophosphomannose-dependent alpha-(1-->6)-mannosyltransferase involved in mycobacterial LAM biosynthesis demonstrated that the enzyme is somewhat tolerant substitution at this site. The enzyme recognizes the disaccharides with groups similar or smaller in size than the native hydroxyl (6-8), but not the disaccharide with the more sterically demanding methoxy group (5). The 2'-OH appears not form a critical hydrogen bonding interaction with the protein as the 2'-deoxy analog is a substrate for the enzyme.
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Affiliation(s)
- Vinodhkumar Subramaniam
- Department of Chemistry, The Ohio State University, 100 West 18th Avenue, Columbus, OH 43210, USA
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15
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Synthesis of fully protected α-l-fucopyranosyl-(1→2)-β-d-galactopyranosides with a single free hydroxy group at position 2′, 3′ or 4′ using O-(2-naphthyl)methyl (NAP) ether as a temporary protecting group. ACTA ACUST UNITED AC 2005. [DOI: 10.1016/j.tetasy.2004.11.056] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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16
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Hua Y, Du Y, Yu G, Chu S. Synthesis and biological activities of octyl 2,3-di-O-sulfo-α-l-fucopyranosyl-(1→3)-2-O-sulfo-α-l-fucopyranosyl-(1→4)-2,3-di-O-sulfo-α-l-fucopyranosyl-(1→3)-2-O-sulfo-α-l-fucopyranosyl-(1→4)-2,3-di-O-sulfo-β-l-fucopyranoside. Carbohydr Res 2004; 339:2083-90. [PMID: 15280053 DOI: 10.1016/j.carres.2004.06.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2004] [Accepted: 06/05/2004] [Indexed: 10/26/2022]
Abstract
Octyl 2,3-di-O-sulfo-alpha-L-fucopyranosyl-(1-->3)-2-O-sulfo-alpha-L-fucopyranosyl-(1-->4)-2,3-di-O-sulfo-alpha-L-fucopyranosyl-(1-->3)-2-O-sulfo-alpha-L-fucopyranosyl-(1-->4)-2,3-di-O-sulfo-beta-L-fucopyranoside, a fucosyl pentasaccharide with a regular structure resembling the repeating unit of a natural sulfated fucan, was chemically synthesized using a convergent '2+3' strategy. Regioselective 3-O-silylation of beta-thiofucopyranoside and AgOTf-catalyzed glycosylation of the protected glycosyl trichloroacetimidate facilitated a one-pot trisaccharide synthesis. The synthesized target compound showed good antitumor activity in vivo, and promising anticoagulant activity in vitro.
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Affiliation(s)
- Yuxia Hua
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, PO Box 2871, Beijing 100085, PR China
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17
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Cociorva OM, Lowary TL. Synthesis of oligosaccharides as potential inhibitors of mycobacterial arabinosyltransferases. Di- and trisaccharides containing C-5 modified arabinofuranosyl residues. Carbohydr Res 2004; 339:853-65. [PMID: 14980829 DOI: 10.1016/j.carres.2003.12.015] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2003] [Accepted: 12/16/2003] [Indexed: 11/17/2022]
Abstract
The synthesis of a panel of oligosaccharides containing C-5 arabinofuranosyl residues (9-20) is described. These compounds are of interest as potential inhibitors of the alpha-(1-->5)-arabinosyltransferase involved in the assembly of mycobacterial cell-wall arabinan. In the series of compounds prepared, the 5-OH group on the nonreducing residue(s) is replaced, independently, with an amino, azido, fluoro, or methoxy functionality. The synthesis of the target compounds involved the preparation of a series of C-5 modified arabinofuranosyl thioglycosides (24-26) and their subsequent coupling to the appropriate acceptor species (21-23). Deprotection of the glycosylation products afforded the azido, fluoro, or methoxy analogs directly. The amino derivatives were obtained in one additional step by reduction of the azido compounds.
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Affiliation(s)
- Oana M Cociorva
- Department of Chemistry, The Ohio State University, 100 West 18th Avenue, Columbus, OH 43210, USA
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18
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Abstract
All possible eight monomethylated dioscin derivatives (1-8) were synthesized. Their inhibitory activities against P388 and A-549 cells were determined, and the results indicate that six of the eight hydroxyls of dioscin are the 'key polar groupings' for tumor inhibitory activities.
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Affiliation(s)
- Ming Li
- State Key Laboratory of Catalyst, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
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19
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Xia J, Alderfer JL, Srikrishnan T, Chandrasekaran EV, Matta KL. A convergent synthesis of core 2 branched sialylated and sulfated oligosaccharides. Bioorg Med Chem 2002; 10:3673-84. [PMID: 12213483 DOI: 10.1016/s0968-0896(02)00246-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A convergent pathway for the syntheses of core 2 oligosaccharide analogues 1 and 2, and a natural form sialylated and sulfated hexasaccharide 3 was developed. Construction of pentasaccharides 24, 27 and hexasaccharide 28 was achieved by complete regioselective glycosylation of the 6-OH in the acceptors 5, 7 and 8, respectively, owing to the much higher reactivity of the primary hydroxyl group over the secondary axial hydroxyl group in these structures. Stereoselective sialylation was accomplished using donor 10 with defined configuration established through X-ray crystallographic analysis. Target oligosaccharides 1-3 were then obtained by the systematic deprotection of intermediates 24, 27 and 29. With these target oligosaccharides 1-3 obtained, biological evaluations of these molecules as enzyme substrates was undertaken and selectin binding studies are planned.
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Affiliation(s)
- Jie Xia
- Molecular & Cellular Biophysics, Roswell Park Cancer Institute, Elm & Carlton Streets, Buffalo, NY 14263, USA
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