1
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Escopy S, Demchenko AV. Transition-Metal-Mediated Glycosylation with Thioglycosides. Chemistry 2021; 28:e202103747. [PMID: 34935219 DOI: 10.1002/chem.202103747] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Indexed: 11/09/2022]
Abstract
Thioglycosides are among the most common glycosyl donors that find broad application in the synthesis of glycans and glycoconjugates. However, the requirement for toxic and/or large access of activators needed for common glycosylations with thioglycosides remains a notable drawback. Due to the increased awareness of the chemical waste impact on the environment, synthetic studies have been driven by the goal of finding non-toxic reagents. The main focus of this review is to highlight recent methods for thioglycoside activation that rely on transition metal catalysis.
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Affiliation(s)
- Samira Escopy
- University of Missouri - St. Louis, Chemistry, UNITED STATES
| | - Alexei V Demchenko
- Saint Louis University, Chemistry, 3501 Laclede Ave, 63103, St. Louis, UNITED STATES
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2
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Wang L, Guo Z. An extensive review of studies on mycobacterium cell wall polysaccharide-related oligosaccharides – part I: Synthetic studies on arabinofuranosyl oligosaccharides. J Carbohydr Chem 2019. [DOI: 10.1080/07328303.2019.1630839] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Lizhen Wang
- Biology Institute, Qilu University of Technology (Shandong Academy of Sciences), Ji'nan, China
| | - Zhongwu Guo
- Department of Chemistry, University of Florida, Gainesville, FL, USA
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3
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Corcilius L, Hastwell AH, Zhang M, Williams J, Mackay JP, Gresshoff PM, Ferguson BJ, Payne RJ. Arabinosylation Modulates the Growth-Regulating Activity of the Peptide Hormone CLE40a from Soybean. Cell Chem Biol 2017; 24:1347-1355.e7. [PMID: 28943356 DOI: 10.1016/j.chembiol.2017.08.014] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 07/05/2017] [Accepted: 08/15/2017] [Indexed: 11/21/2022]
Abstract
Small post-translationally modified peptide hormones mediate crucial developmental and regulatory processes in plants. CLAVATA/ENDOSPERM-SURROUNDING REGION (CLE) genes are found throughout the plant kingdom and encode for 12-13 amino acid peptides that must often undergo post-translational proline hydroxylation and glycosylation with O-β1,2-triarabinose moieties before they become functional. Apart from a few recent examples, a detailed understanding of the structure and function of most CLE hormones is yet to be uncovered. This is mainly owing to difficulties in isolating mature homogeneously modified CLE peptides from natural plant sources. In this study, we describe the efficient synthesis of a synthetic Araf3Hyp glycosylamino acid building block that was used to access a hitherto uninvestigated CLE hormone from soybean called GmCLE40a. Through the development and implementation of a novel in vivo root growth assay, we show that the synthetic triarabinosylated glycopeptide suppresses primary root growth in this important crop species.
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Affiliation(s)
- Leo Corcilius
- School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia
| | - April H Hastwell
- Centre for Integrative Legume Research, School of Agriculture and Food Sciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Mengbai Zhang
- Centre for Integrative Legume Research, School of Agriculture and Food Sciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - James Williams
- School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia
| | - Joel P Mackay
- School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW 2006, Australia
| | - Peter M Gresshoff
- Centre for Integrative Legume Research, School of Agriculture and Food Sciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Brett J Ferguson
- Centre for Integrative Legume Research, School of Agriculture and Food Sciences, The University of Queensland, Brisbane, QLD 4072, Australia.
| | - Richard J Payne
- School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia.
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4
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Xing L, Niu Q, Li C. Practical Glucosylations and Mannosylations Using Anomeric Benzoyloxy as a Leaving Group Activated by Sulfonium Ion. ACS OMEGA 2017; 2:3698-3709. [PMID: 30023701 PMCID: PMC6044952 DOI: 10.1021/acsomega.7b00729] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/04/2017] [Accepted: 07/06/2017] [Indexed: 06/08/2023]
Abstract
One obstacle for practical glycosylations is the high cost of promoters and low-temperature equipment. This problem has been at least partially solved by using MeSCH2Cl/KI as a low-cost promoter system. MeSCH2Cl has an estimated cost of <$1/mol compared with $1741/mol for AgOTf and $633/mol for TMSOTf. This new promoter system is capable of activating various leaving groups including anomeric Cl, F, trichloroacetimidate, and acyloxy groups. Stable and easy-to-prepare anomeric benzoloxy carbohydrate donors were investigated in the glycosylations of carbohydrates, aliphatic alcohols, amino acids, steroids, and nucleoside acceptors. Most of these glycosylations were operationally simple with fast reaction rates and moderate yields of 35-79%. In addition, direct glycosylations of nucleosides using less than 2 equiv of anomeric benzoloxy donors and high stereoselective mannosylation have been achieved. From an economic point of view, this glycosylation method should be highly applicable to industrial processes.
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Affiliation(s)
- Linlin Xing
- Department of Chemistry, School of Science, Tianjin University, 135 Yaguan Road, Jinnan District, Tianjin 300354, P. R. China
| | - Qun Niu
- Department of Chemistry, School of Science, Tianjin University, 135 Yaguan Road, Jinnan District, Tianjin 300354, P. R. China
| | - Chunbao Li
- Department of Chemistry, School of Science, Tianjin University, 135 Yaguan Road, Jinnan District, Tianjin 300354, P. R. China
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5
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Lee BY, Oh JW, Baek JY, Jeon HB, Kim KS. Phthalic Anhydride-Mediated Direct Glycosylation of Anomeric Hydroxy Arabinofuranose: Synthesis of Repeating Oligoarabinofuranoside and Tetradecasaccharide Arabinan Motif of Mycobacterial Cell Wall. J Org Chem 2016; 81:11372-11383. [DOI: 10.1021/acs.joc.6b01723] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Bo-Young Lee
- Center
for Bioactive Molecular Hybrids and Department of Chemistry, Yonsei University, Seoul 120-749, Korea
| | - Jung Woo Oh
- Center
for Bioactive Molecular Hybrids and Department of Chemistry, Yonsei University, Seoul 120-749, Korea
| | - Ju Yuel Baek
- Center
for Bioactive Molecular Hybrids and Department of Chemistry, Yonsei University, Seoul 120-749, Korea
| | - Heung Bae Jeon
- Department
of Chemistry, Kwangwoon University, Seoul 139-701, Korea
| | - Kwan Soo Kim
- Center
for Bioactive Molecular Hybrids and Department of Chemistry, Yonsei University, Seoul 120-749, Korea
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6
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Abstract
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The cell surface (or cell wall) of bacteria is coated with carbohydrate
(or glycan) structures that play a number of important roles. These
include providing structural integrity, serving as a permeability
barrier to extracellular compounds (e.g., drugs) and modulating the
immune system of the host. Of interest to this Account is the cell
wall structure of mycobacteria. There are a host of different mycobacterial
species, some of which cause human disease. The most well-known is Mycobacterium tuberculosis, the causative agent of tuberculosis.
The mycobacterial cell wall is characterized by the presence of unusual
carbohydrate structures that fulfill the roles described above. However,
in many cases, a molecular-level understanding of how mycobacterial
cell wall glycans mediate these processes is lacking. Inspired
by a seminar he heard as a postdoctoral fellow, the author
began his independent research program with a focus on the chemical
synthesis of mycobacterial glycans. The goals were not only to develop
synthetic approaches to these unique structures but also to provide
molecules that could be used to probe their biological function. Initial
work addressed the preparation of fragments of two key polysaccharides,
arabinogalactan and lipoarabinomannan, which contain large numbers
of sugar residues in the furanose (five-membered) ring form. At the
time these investigations began, there were few methods reported for
the synthesis of oligosaccharides containing furanose rings. Thus,
early in the program, a major area of interest was methodology development,
particularly for the preparation of 1,2-cis-furanosides.
To solve this challenge, a range of conformationally restricted donors
have been developed, both in the author’s group and others,
which provide 1,2-cis-furanosidic linkages with high
stereoselectivity. These investigations were followed by application
of the developed
methods to the synthesis of a range of target molecules containing
arabinofuranose and galactofuranose residues. These molecules have
now found application in biochemical, immunological, and structural
biology investigations, which have shed light on their biosynthesis
and how these motifs are recognized by both the innate and adaptive
immune systems. More recently, attention has been directed toward
the synthesis
of another class of immunologically active mycobacterial cell wall
glycans, the extractable glycolipids. In this case, efforts have been
primarily on phenolic glycolipids, and the compounds synthesized have
been used to evaluate their ability to modulate cytokine release.
Over the past 20 years, the use of chemical synthesis to provide increasingly
complex glycan structures has provided significant benefit to the
burgeoning field of mycobacterial glycobiology. Through the efforts
of groups from around the globe, access to these compounds is now
possible via relatively straightforward methods. As the pool of mycobacterial
glycans continues to grow, so too will our understanding of their
role in disease, which will undoubtedly lead to new strategies to
prevent or treat mycobacterial infections.
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Affiliation(s)
- Todd L. Lowary
- Alberta Glycomics Centre
and Department of Chemistry, University of Alberta, Gunning−Lemieux
Chemistry Centre, Edmonton, Alberta T6G 2G2, Canada
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7
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Wang L, Feng S, An L, Gu G, Guo Z. Synthetic and Immunological Studies of Mycobacterial Lipoarabinomannan Oligosaccharides and Their Protein Conjugates. J Org Chem 2015; 80:10060-75. [DOI: 10.1021/acs.joc.5b01686] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Lizhen Wang
- National Glycoengineering
Research Center, School of Life Science, Shandong University, Jinan 250100, China
| | - Shaojie Feng
- National Glycoengineering
Research Center, School of Life Science, Shandong University, Jinan 250100, China
| | - Lian An
- National Glycoengineering
Research Center, School of Life Science, Shandong University, Jinan 250100, China
| | - Guofeng Gu
- National Glycoengineering
Research Center, School of Life Science, Shandong University, Jinan 250100, China
| | - Zhongwu Guo
- National Glycoengineering
Research Center, School of Life Science, Shandong University, Jinan 250100, China
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8
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Kumar V, Taxak N, Jangir R, Bharatam PV, Kartha KPR. In(III) triflate-mediated solvent-free synthesis and activation of thioglycosides by ball milling and structural analysis of long chain alkyl thioglycosides by TEM and quantum chemical methods. J Org Chem 2014; 79:3427-39. [PMID: 24669760 DOI: 10.1021/jo5001753] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Conventional solution-phase synthesis of thioglycosides from glycosyl acetates and thiols in the presence of In(III) triflate as reported for benzyl thioglucoside failed when applied to the synthesis of phenolic and alkyl thioglycosides. But, it was achieved in high efficiency and diastereospecificity with ease by solvent-free grinding in a ball mill. The acetates in turn were also obtained by the homogenization of free sugars with stoichiometric amounts of acetic anhydride and catalytic In(OTf)3 in the mill as neat products. Per-O-benzylated thioglycosides on grinding with an acceptor sugar in the presence of In(OTf)3 yield the corresponding O-glycosides efficiently. The latter in the case of a difficult secondary alcohol was nearly exclusive (>98%) in 1,2-cis-selectivity. In contrast, the conventional methods for this purpose require use of a coreagent such as NIS along with the Lewis acid to help generate the electrophilic species that actually is responsible for the activation of the thioglycoside donor in situ. The distinctly different self-assembling features of the peracetylated octadecyl 1-thio-α- and β-D-galactopyranosides observed by TEM could be rationalized by molecular modeling.
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Affiliation(s)
- Vajinder Kumar
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research , S.A.S. Nagar, Punjab 160062, India
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9
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Liang XY, Bin HC, Yang JS. Tuning effect of silyl protecting groups on the glycosylation reactivity of arabinofuranosyl thioglycosides. Org Lett 2013; 15:2834-7. [PMID: 23682928 DOI: 10.1021/ol401166x] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The tuning effect of silyl protecting groups on the glycosylation reactivity of arabinofuranosyl phenyl thioglycoside donors is presented. Silyl ethers on the 3-, 5-, and 3,5-positions of the arabinofuranose ring are found to have an arming effect on the donor reactivity, whereas the cyclic 3,5-acetal type protecting groups reduce the reactivity.
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Affiliation(s)
- Xing-Yong Liang
- Key Laboratory of Drug Targeting and Drug Delivery Systems of the Ministry of Education, Department of Chemistry of Medicinal Natural Products, West China School of Pharmacy, Sichuan University, Chengdu 610041, China
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10
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Ekholm FS, Ardá A, Eklund P, André S, Gabius HJ, Jiménez-Barbero J, Leino R. Studies related to Norway spruce galactoglucomannans: chemical synthesis, conformation analysis, NMR spectroscopic characterization, and molecular recognition of model compounds. Chemistry 2012; 18:14392-405. [PMID: 23008171 DOI: 10.1002/chem.201200510] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Revised: 05/16/2012] [Indexed: 12/20/2022]
Abstract
Galactoglucomannan (GGM) is a polysaccharide mainly consisting of mannose, glucose, and galactose. GGM is the most abundant hemicellulose in the Norway spruce (Picea abies), but is also found in the cell wall of flax seeds, tobacco plants, and kiwifruit. Although several applications for GGM polysaccharides have been developed in pulp and paper manufacturing and the food and medical industries, attempts to synthesize and study distinct fragments of this polysaccharide have not been reported previously. Herein, the synthesis of one of the core trisaccharide units of GGM together with a less-abundant tetrasaccharide fragment is described. In addition, detailed NMR spectroscopic characterization of the model compounds, comparison of the spectral data with natural GGM, investigation of the acetyl-group migration phenomena that takes place in the polysaccharide by using small model compounds, and a binding study between the tetrasaccharide model fragment and a galactose-binding protein (the toxin viscumin) are reported.
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Affiliation(s)
- Filip S Ekholm
- Laboratory of Organic Chemistry, Åbo Akademi University, Piispankatu 8, 20500 Åbo, Finland
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11
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Chao CS, Lin CY, Mulani S, Hung WC, Mong KKT. Neighboring-Group Participation by C-2 Ether Functions in Glycosylations Directed by Nitrile Solvents. Chemistry 2011; 17:12193-202. [DOI: 10.1002/chem.201100732] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2011] [Indexed: 01/10/2023]
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12
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13
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Synthesis of partially benzylated arabinofuranosides, NMR analysis, and application to oligosaccharide synthesis. ACTA ACUST UNITED AC 2010. [DOI: 10.1016/j.tetasy.2010.06.033] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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14
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Tam PH, Lowary TL. Mycobacterial lipoarabinomannan fragments as haptens for potential anti-tuberculosis vaccines. CARBOHYDRATE CHEMISTRY 2010. [DOI: 10.1039/9781849730891-00038] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Pui-Hang Tam
- Alberta Ingenuity Centre for Carbohydrate Science and Department of Chemistry, The University of Alberta Gunning-Lemieux Chemistry Centre Edmonton AB, T6G 2G2 Canada
| | - Todd L. Lowary
- Alberta Ingenuity Centre for Carbohydrate Science and Department of Chemistry, The University of Alberta Gunning-Lemieux Chemistry Centre Edmonton AB, T6G 2G2 Canada
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15
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Liu C, Richards MR, Lowary TL. Probing the Effect of Acylation on Arabinofuranose Ring Conformation in Di- and Trisaccharide Fragments of Mycobacterial Arabinogalactan. J Org Chem 2010; 75:4992-5007. [DOI: 10.1021/jo100575a] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Chunjuan Liu
- Alberta Ingenuity Centre for Carbohydrate Science and Department of Chemistry, The University of Alberta, Gunning-Lemieux Chemistry Centre, Edmonton, Alberta, T6G 2G2 Canada
| | - Michele R. Richards
- Alberta Ingenuity Centre for Carbohydrate Science and Department of Chemistry, The University of Alberta, Gunning-Lemieux Chemistry Centre, Edmonton, Alberta, T6G 2G2 Canada
| | - Todd L. Lowary
- Alberta Ingenuity Centre for Carbohydrate Science and Department of Chemistry, The University of Alberta, Gunning-Lemieux Chemistry Centre, Edmonton, Alberta, T6G 2G2 Canada
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16
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Wang Y, Maguire-Boyle S, Dere RT, Zhu X. Synthesis of beta-D-arabinofuranosides: stereochemical differentiation between D- and L-enantiomers. Carbohydr Res 2008; 343:3100-6. [PMID: 18809174 DOI: 10.1016/j.carres.2008.09.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2008] [Revised: 08/22/2008] [Accepted: 09/04/2008] [Indexed: 10/21/2022]
Abstract
The glycosylation of 3,5-O-di-tert-butylsilylene-protected d-thioarabinofuranosides with a range of glycosyl acceptors using NIS/AgOTf as promoters proceeded in a stereoselective manner to give the corresponding beta-D-arabinofuranosides in high yields.
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Affiliation(s)
- Yingxi Wang
- Centre for Synthesis and Chemical Biology, UCD School of Chemistry and Chemical Biology, University College Dublin, Belfield, Dublin 4, Ireland
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17
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Kim KS, Fulse DB, Baek JY, Lee BY, Jeon HB. Stereoselective Direct Glycosylation with Anomeric Hydroxy Sugars by Activation with Phthalic Anhydride and Trifluoromethanesulfonic Anhydride Involving Glycosyl Phthalate Intermediates. J Am Chem Soc 2008; 130:8537-47. [DOI: 10.1021/ja710935z] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Kwan Soo Kim
- Center for Bioactive Molecular Hybrids and the Department of Chemistry, Yonsei University, Seoul 120-749, Korea, and the Department of Chemistry, Kwangwoon University, Seoul 139-701, Korea
| | - Dinanath Baburao Fulse
- Center for Bioactive Molecular Hybrids and the Department of Chemistry, Yonsei University, Seoul 120-749, Korea, and the Department of Chemistry, Kwangwoon University, Seoul 139-701, Korea
| | - Ju Yuel Baek
- Center for Bioactive Molecular Hybrids and the Department of Chemistry, Yonsei University, Seoul 120-749, Korea, and the Department of Chemistry, Kwangwoon University, Seoul 139-701, Korea
| | - Bo-Young Lee
- Center for Bioactive Molecular Hybrids and the Department of Chemistry, Yonsei University, Seoul 120-749, Korea, and the Department of Chemistry, Kwangwoon University, Seoul 139-701, Korea
| | - Heung Bae Jeon
- Center for Bioactive Molecular Hybrids and the Department of Chemistry, Yonsei University, Seoul 120-749, Korea, and the Department of Chemistry, Kwangwoon University, Seoul 139-701, Korea
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18
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Kim KS, Jeon HB. Lactonization-mediated glycosylations and their application to oligosaccharide synthesis. CHEM REC 2008; 8:46-65. [DOI: 10.1002/tcr.20138] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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19
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Crich D, Pedersen CM, Bowers AA, Wink DJ. On the use of 3,5-O-benzylidene and 3,5-O-(di-tert-butylsilylene)-2-O-benzylarabinothiofuranosides and their sulfoxides as glycosyl donors for the synthesis of beta-arabinofuranosides: importance of the activation method. J Org Chem 2007; 72:1553-65. [PMID: 17286432 PMCID: PMC2617737 DOI: 10.1021/jo061440x] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A 2-O-benzyl-3,5-O-benzylidene-alpha-d-thioarabinofuranoside was obtained by reaction of the corresponding diol with alpha,alpha-dibromotoluene under basic conditions. On activation with 1-benzenesulfinyl piperidine, or diphenyl sulfoxide, and trifluoromethanesulfonic anhydride in dichloromethane at -55 degrees C, reaction with glycosyl acceptors affords anomeric mixtures with little or no selectivity. The analogous 2-O-benzyl-3,5-O-(di-tert-butylsilylene)-alpha-d-thioarabinofuranoside also showed no significant selectivity under the 1-benzenesulfinyl piperidine or diphenyl sulfoxide conditions. With N-iodosuccinimide and silver trifluoromethanesulfonate the silylene acetal showed moderate to high beta-selectivity, independent of the configuration of the starting thioglycoside. High beta-selectivity was also obtained with a 2-O-benzyl-3,5-O-(di-tert-butylsilylene)-alpha-arabinofuranosyl sulfoxide donor on activation with trifluoromethanesulfonic anhydride. The high beta-selectivities obtained by the N-iodosuccinimide/silver trifluoromethanesulfonate and sulfoxide methods are consistent with a common intermediate, most likely to be the oxacarbenium ion. The poor selectivity observed on activation of the thioglycosides with the 1-benzenesulfinyl piperidine, or diphenyl sulfoxide, and trifluoromethanesulfonic anhydride methods appears to be the result of the formation of a complex mixture of glycosyl donors, as determined by low-temperature NMR work.
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Affiliation(s)
- David Crich
- Department of Chemistry, University of Illinois at Chicago, 845 West Taylor Street, Chicago, IL 60607-7061, USA.
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20
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Cociorva OM, Lowary TL. 2,3-Anhydrosugars in glycoside bond synthesis. Application to the preparation of C-2 functionalized α-d-arabinofuranosides. Tetrahedron 2004. [DOI: 10.1016/j.tet.2003.12.022] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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21
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Wen X, Crick DC, Brennan PJ, Hultin PG. Analogues of the mycobacterial arabinogalactan linkage disaccharide as cell wall biosynthesis inhibitors. Bioorg Med Chem 2003; 11:3579-87. [PMID: 12901902 DOI: 10.1016/s0968-0896(03)00366-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The mycobacterial arabinogalactan linkage disaccharide [alpha-L-Rha-(1-->3)-alpha-D-GlcNAc] provides a basis for the design of new antitubercular drugs, since it supports a key skeletal structure in the bacterial cell wall. A series of analogues of the linker was synthesized by coupling appropriate thiorhamnosyl donors modified at their 4-positions, with an N-acetyl glucosamine acceptor. In a cell-free enzyme inhibition assay, three analogues inhibited the activity of the galactosyltransferase that adds a Galf residue to the linkage disaccharide. Although the compounds were modest inhibitors, these data confirm the viability of this approach to anti-mycobacterial agents. It is especially significant that the three effective compounds are modified at the site of the acceptor atom in the natural substrate.
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Affiliation(s)
- Xianghui Wen
- Department of Chemistry, University of Manitoba, R3T 2N2, Winnipeg, MB, Canada
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22
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Gadikota RR, Callam CS, Wagner T, Del Fraino B, Lowary TL. 2,3-Anhydro sugars in glycoside bond synthesis. Highly stereoselective syntheses of oligosaccharides containing alpha- and beta-arabinofuranosyl linkages. J Am Chem Soc 2003; 125:4155-65. [PMID: 12670238 DOI: 10.1021/ja029302m] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The ever-increasing discovery of biologically important events mediated by carbohydrates has generated great interest in the synthesis of oligosaccharides and the development of new methods for glycosidic bond formation. In this paper, we report that 2,3-anhydrofuranose thioglycosides (1, 5) and glycosyl sulfoxides (2, 6), in which the hydroxyl groups C-2 and C-3 are "protected" as an epoxide, glycosylate alcohols with an exceptionally high degree of stereocontrol. The predominant or exclusive product of reactions with this fundamentally new class of glycosylating agent is that in which the newly formed glycosidic bond is cis to the epoxide moiety. We further demonstrate that subsequent nucleophilic opening of the epoxide moiety proceeds under basic conditions to give products in high yield and with good to excellent regioselectivity. The major ring-opened products possess the arabino stereochemistry, and thus this methodology constitutes a new approach for the synthesis of arabinofuranosides. In the epoxide opening reactions of glycosides with the 2,3-anhydro-beta-D-lyxo stereochemistry (e.g., 73), the addition of (-)-sparteine (78) to the reaction mixture dramatically enhanced the regioselectivity in favor of the arabino product. This represents the first example of the use of 78 to influence the regioselectivity of an epoxide ring opening reaction with a non-carbon nucleophile. We have demonstrated the utility of this methodology through the efficient synthesis of an arabinofuranosyl hexasaccharide, 7, which is a key structural motif in two mycobacterial cell wall polysaccharides.
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23
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First synthesis of methyl α-C-d-arabinofuranosyl-(1→5)-α-d-arabinofuranoside: the C-disaccharide segment of motif C of Mycobacterium tuberculosis. Tetrahedron Lett 2002. [DOI: 10.1016/s0040-4039(02)01760-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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