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Wheatley DE, Fontenelle CQ, Kuppala R, Szpera R, Briggs EL, Vendeville JB, Wells NJ, Light ME, Linclau B. Synthesis and Structural Characteristics of all Mono- and Difluorinated 4,6-Dideoxy-d- xylo-hexopyranoses. J Org Chem 2021; 86:7725-7756. [PMID: 34029099 DOI: 10.1021/acs.joc.1c00796] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Protein-carbohydrate interactions are implicated in many biochemical/biological processes that are fundamental to life and to human health. Fluorinated carbohydrate analogues play an important role in the study of these interactions and find application as probes in chemical biology and as drugs/diagnostics in medicine. The availability and/or efficient synthesis of a wide variety of fluorinated carbohydrates is thus of great interest. Here, we report a detailed study on the synthesis of monosaccharides in which the hydroxy groups at their 4- and 6-positions are replaced by all possible mono- and difluorinated motifs. Minimization of protecting group use was a key aim. It was found that introducing electronegative substituents, either as protecting groups or as deoxygenation intermediates, was generally beneficial for increasing deoxyfluorination yields. A detailed structural study of this set of analogues demonstrated that dideoxygenation/fluorination at the 4,6-positions caused very little distortion both in the solid state and in aqueous solution. Unexpected trends in α/β anomeric ratios were identified. Increasing fluorine content always increased the α/β ratio, with very little difference between regio- or stereoisomers, except when 4,6-difluorinated.
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Affiliation(s)
- David E Wheatley
- School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, U.K
| | - Clement Q Fontenelle
- School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, U.K
| | - Ramakrishna Kuppala
- School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, U.K
| | - Robert Szpera
- School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, U.K
| | - Edward L Briggs
- School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, U.K
| | | | - Neil J Wells
- School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, U.K
| | - Mark E Light
- School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, U.K
| | - Bruno Linclau
- School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, U.K
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Affiliation(s)
| | - Mikael Bols
- Department of Chemistry, University of Copenhagen, DK-2100 Copenhagen, Denmark
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Frihed TG, Pedersen CM, Bols M. Synthesis of All Eight Stereoisomeric 6-Deoxy-L-hexopyranosyl Donors - Trends in Using Stereoselective Reductions or Mitsunobu Epimerizations. European J Org Chem 2014. [DOI: 10.1002/ejoc.201403074] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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Synthetic analogues of mycobacterial arabinogalactan linkage-disaccharide part II: synthesis and preliminary screening of lipophilic O-alkyl glycosides. Carbohydr Res 2011; 346:2401-5. [PMID: 21962454 DOI: 10.1016/j.carres.2011.08.027] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2011] [Revised: 08/17/2011] [Accepted: 08/25/2011] [Indexed: 11/24/2022]
Abstract
Lipophilic analogues of the linkage-disaccharide found in the mycobacterial cell wall were synthesized and the synthetic analogues when biologically evaluated showed promising antimycobacterial property with MIC value in the range 3.13-12.50 μg/mL against Mycobacterium tuberculosis H(37)Rv.
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Sofian ASM, Lee CK. C-4 EPIMERIZATION OF α-D-GLUCOPYRANOSIDE: A FACILE SYNTHESIS OF 4-O-ACETYL-α-D-GALACTOPYRANOSYL DERIVATIVES. J Carbohydr Chem 2006. [DOI: 10.1081/car-100106926] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- A. S. Md. Sofian
- a Department of Chemistry , National University of Singapore , Kent Ridge, 0511, Singapore
| | - C. Kuan Lee
- b Department of Chemistry , National University of Singapore , Kent Ridge, 0511, Singapore
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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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Pathak AK, Pathak V, Seitz L, Maddry JA, Gurcha SS, Besra GS, Suling WJ, Reynolds RC. Studies on (beta,1-->5) and (beta,1-->6) linked octyl Gal(f) disaccharides as substrates for mycobacterial galactosyltransferase activity. Bioorg Med Chem 2001; 9:3129-43. [PMID: 11711288 DOI: 10.1016/s0968-0896(01)00179-1] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The emergence of multi-drug resistant (MDR) strains of Mycobacterium tuberculosis (MTB) and the continuing pandemic of tuberculosis emphasizes the urgent need for the development of new anti-tubercular agents with novel drug targets. The recent structural elucidation of the mycobacterial cell wall highlights a large variety of structurally unique components that may be a basis for new drug development. This publication describes the synthesis, characterization, and screening of several octyl Galf(beta,1-->5)Galf and octyl Galf(beta,1-->6)Galf derivatives. A cell-free assay system has been utilized for galactosyltransferase activity using UDP[14C]Galf as the glycosyl donor, and in vitro inhibitory activity has been determined in a colorimetric broth microdilution assay system against MTB H37Ra and three clinical isolates of Mycobacterium avium complex (MAC). Certain derivatives showed moderate activities against MTB and MAC. The biological evaluation of these disaccharides suggests that more hydrophobic analogues with a blocked reducing end showed better activity as compared to totally deprotected disaccharides that more closely resemble the natural substrates in cell wall biosynthesis.
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Affiliation(s)
- A K Pathak
- Department of Organic Chemistry, Southern Research Institute, PO Box 55305, Birmingham, AL 35255-5305, USA
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