1
|
Szcześniak P, Furman B. Concise synthesis of bicyclic iminosugars via reductive functionalization of sugar-derived lactams and subsequent RCM reaction. Org Biomol Chem 2021; 19:6842-6846. [PMID: 34318856 DOI: 10.1039/d1ob01172c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An efficient method for the synthesis of bicyclic iminosugars has been developed. The strategy is based on the partial reduction of sugar-derived lactams by Schwartz's reagent and tandem stereoselective nucleophile addition dictated by Woerpel's model which affords polyhydroxylated cyclic amines as key intermediates. Introduction of a vinyl or allyl group to the iminosugar produces diene derivatives that can be subjected to the ring-closing metathesis reaction (RCM) to furnish polyhydroxylated pyrrolizidine, indolizidine and quinozilidine derivatives in good to excellent yields. This sequence of reactions has been applied to the formal synthesis of hyacinthacine A2, a polyhydroxylated pyrrolizidine alkaloid.
Collapse
Affiliation(s)
- Piotr Szcześniak
- Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland.
| | | |
Collapse
|
2
|
Biosynthesis of Galactan in Mycobacterium tuberculosis as a Viable TB Drug Target? Antibiotics (Basel) 2020; 9:antibiotics9010020. [PMID: 31935842 PMCID: PMC7168186 DOI: 10.3390/antibiotics9010020] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 12/27/2019] [Accepted: 01/02/2020] [Indexed: 12/21/2022] Open
Abstract
While target-based drug design has proved successful in several therapeutic areas, this approach has not yet provided compelling outcomes in the field of antibacterial agents. This statement remains especially true for the development of novel therapeutic interventions against tuberculosis, an infectious disease that is among the top ten leading causes of death globally. Mycobacterial galactan is an important component of the protective cell wall core of the tuberculosis pathogen and it could provide a promising target for the design of new drugs. In this review, we summarize the current knowledge on galactan biosynthesis in Mycobacterium tuberculosis, including landmark findings that led to the discovery and understanding of three key enzymes in this pathway: UDP-galactose mutase, and galactofuranosyl transferases GlfT1 and GlfT2. Moreover, we recapitulate the efforts aimed at their inhibition. The predicted common transition states of the three enzymes provide the lucrative possibility of multitargeting in pharmaceutical development, a favourable property in the mitigation of drug resistance. We believe that a tight interplay between target-based computational approaches and experimental methods will result in the development of original inhibitors that could serve as the basis of a new generation of drugs against tuberculosis.
Collapse
|
3
|
|
4
|
|
5
|
Synthesis and glycosidase inhibition evaluation of (3S,4S)-3-((R)-1,2-dihydroxyethyl)pyrrolidine-3,4-diol. Carbohydr Res 2016; 434:33-36. [PMID: 27563841 DOI: 10.1016/j.carres.2016.08.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2016] [Revised: 07/26/2016] [Accepted: 08/02/2016] [Indexed: 11/22/2022]
Abstract
A new azasugar (3S,4S)-3-((R)-1,2-dihydroxyethyl)pyrrolidine-3,4-diol (1) was obtained from commercially available d-glucose using one-pot reductive cyclization as a key step. The target product, i.e., the iminosugar isomer, was obtained in 10 steps and 24.3% overall yield. Only three column chromatography purifications were needed in this synthesis. The biological activity of the target molecule as glycosidase inhibitor was studied, but the inhibitory activity against four glycosidases was not good (IC50 > 100 μM).
Collapse
|
6
|
Mechanism-based candidate inhibitors of uridine diphosphate galactopyranose mutase (UGM). Carbohydr Res 2015; 419:1-7. [PMID: 26595659 DOI: 10.1016/j.carres.2015.10.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2015] [Revised: 10/20/2015] [Accepted: 10/22/2015] [Indexed: 01/07/2023]
Abstract
Uridine diphosphate-galactopyranose mutase (UGM), an enzyme found in many eukaryotic and prokaryotic human pathogens, catalyzes the interconversion of UDP-galactopyranose (UDP-Galp) and UDP-galactofuranose (UDP-Galf), the latter being used as the biosynthetic precursor of the galactofuranose polymer portion of the mycobacterium cell wall. We report here the synthesis of a sulfonium and selenonium ion with an appended polyhydroxylated side chain. These compounds were designed as transition state mimics of the UGM-catalyzed reaction, where the head groups carrying a permanent positive charge were designed to mimic both the shape and positive charge of the proposed galactopyranosyl cation-like transition state. An HPLC-based UGM inhibition assay indicated that the compounds inhibited about 25% of UGM activity at 500 µM concentration.
Collapse
|
7
|
Jagadeesh Y, Tran AT, Luo B, Auberger N, Désiré J, Nakagawa S, Kato A, Zhang Y, Sollogoub M, Blériot Y. γ-Aminoalcohol rearrangement applied to pentahydroxylated azepanes provides pyrrolidines epimeric to homoDMDP. Org Biomol Chem 2015; 13:3446-56. [PMID: 25666467 DOI: 10.1039/c5ob00050e] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A series of pentahydroxylated pyrrolidines, displaying five contiguous stereogenic centres and epimeric to α-glucosidase inhibitor homoDMDP, have been synthesized. The key step involves a γ-aminoalcohol rearrangement applied to polyhydroxylated azepanes. These five-membered iminosugars demonstrate micromolar inhibition of glycosidases.
Collapse
Affiliation(s)
- Y Jagadeesh
- Glycochemistry Group of "Organic Synthesis" Team, Université de Poitiers, UMR-CNRS 7285 IC2MP, 4 rue Michel Brunet, 86073 Poitiers Cedex 9, France.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
8
|
Aher RD, Kumar BS, Sudalai A. Proline-Catalyzed Sequential syn-Mannich and [4 + 1]-Annulation Cascade Reactions To Form Densely Functionalized Pyrrolidines. J Org Chem 2015; 80:2024-31. [DOI: 10.1021/jo5028886] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Ravindra D. Aher
- Chemical Engineering & Process Development Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune, Maharashtra, India 411008
| | - B. Senthil Kumar
- Chemical Engineering & Process Development Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune, Maharashtra, India 411008
| | - Arumugam Sudalai
- Chemical Engineering & Process Development Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune, Maharashtra, India 411008
| |
Collapse
|
9
|
Li J, Lowary TL. Sulfonium ions as inhibitors of the mycobacterial galactofuranosyltransferase GlfT2. MEDCHEMCOMM 2014. [DOI: 10.1039/c4md00067f] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The mycobacterial cell wall possesses a core galactan moiety composed of approximately 30 galactofuranosyl residues attached via alternating β-(1→5) and β-(1→6) linkages.
Collapse
Affiliation(s)
- Jing Li
- Alberta Glycomics Centre and Department of Chemistry
- The University of Alberta
- Gunning–Lemieux Chemistry Centre
- Edmonton
- Canada
| | - Todd L. Lowary
- Alberta Glycomics Centre and Department of Chemistry
- The University of Alberta
- Gunning–Lemieux Chemistry Centre
- Edmonton
- Canada
| |
Collapse
|
10
|
Poulin MB, Zhou R, Lowary TL. Synthetic UDP-galactofuranose analogs reveal critical enzyme-substrate interactions in GlfT2-catalyzed mycobacterial galactan assembly. Org Biomol Chem 2012; 10:4074-87. [PMID: 22499274 DOI: 10.1039/c2ob25159k] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Mycobacterial cell wall galactan, composed of alternating β-(1→5) and β-(1→6) galactofuranosyl residues, is assembled by the action of two bifunctional galactofuranosyltransferases, GlfT1 and GlfT2, which use UDP-galactofuranose (UDP-Galf) as the donor substrate. Kinetic analysis of synthetic UDP-Galf analogs identified critical interactions involved in donor substrate recognition by GlfT2, a processive polymerizing glycosyltransferase. Testing of methylated UDP-Galf analogs showed the donor substrate-binding pocket is sterically crowded. Evaluation of deoxy UDP-Galf analogs revealed that the C-6 hydroxyl group is not essential for substrate activity, and that interactions with the UDP-Galf C-3 hydroxyl group orient the substrate for turnover but appears to play no role in substrate recognition, making the 3-deoxy-analog a moderate competitive inhibitor of the enzyme. Moreover, the addition of a Galf residue deoxygenated at C-5 or C-6, or an l-arabinofuranose residue, to the growing galactan chain resulted in "dead end" reaction products, which no longer act as an acceptor for the enzyme. This finding shows dual recognition of both the terminal C-5 and C-6 hydroxyl groups of the acceptor substrate are required for GlfT2 activity, which is consistent with a recent model developed based upon a crystal structure of the enzyme. These observations provide insight into specific protein-carbohydrate interactions in the GlfT2 active site and may facilitate the design of future inhibitors.
Collapse
Affiliation(s)
- Myles B Poulin
- Alberta Glycomics Centre and Department of Chemistry, Gunning-Lemieux Chemistry Centre, University of Alberta, Edmonton, AB T6G 2G2, Canada
| | | | | |
Collapse
|
11
|
Awan SI, Werz DB. Syntheses of 1,2-annulated and 1-spiroannulated carbohydrate derivatives: Recent developments. Bioorg Med Chem 2012; 20:1846-56. [DOI: 10.1016/j.bmc.2011.10.089] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2011] [Revised: 10/20/2011] [Accepted: 10/30/2011] [Indexed: 01/09/2023]
|
12
|
Narui R, Hayashi S, Otomo H, Shintani R, Hayashi T. (S)-Phenylalanine-derived chiral phosphorus–olefin ligands in rhodium-catalyzed asymmetric 1,4-addition reactions. ACTA ACUST UNITED AC 2012. [DOI: 10.1016/j.tetasy.2012.02.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
13
|
Schmidt B, Krehl S, Jablowski E. Assisted tandem catalytic RCM-aromatization in the synthesis of pyrroles and furans. Org Biomol Chem 2012; 10:5119-30. [DOI: 10.1039/c2ob25543j] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
14
|
Dragutan I, Dragutan V, Mitan C, Vosloo HCM, Delaude L, Demonceau A. Metathesis access to monocyclic iminocyclitol-based therapeutic agents. Beilstein J Org Chem 2011; 7:699-716. [PMID: 21804866 PMCID: PMC3135129 DOI: 10.3762/bjoc.7.81] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2011] [Accepted: 05/05/2011] [Indexed: 02/05/2023] Open
Abstract
By focusing on recent developments on natural and non-natural azasugars (iminocyclitols), this review bolsters the case for the role of olefin metathesis reactions (RCM, CM) as key transformations in the multistep syntheses of pyrrolidine-, piperidine- and azepane-based iminocyclitols, as important therapeutic agents against a range of common diseases and as tools for studying metabolic disorders. Considerable improvements brought about by introduction of one or more metathesis steps are outlined, with emphasis on the exquisite steric control and atom-economical outcome of the overall process. The comparative performance of several established metathesis catalysts is also highlighted.
Collapse
Affiliation(s)
- Ileana Dragutan
- Institute of Organic Chemistry, Romanian Academy, 202B Spl. Independentei, P.O. Box 35-108, Bucharest 060023, Romania
| | - Valerian Dragutan
- Institute of Organic Chemistry, Romanian Academy, 202B Spl. Independentei, P.O. Box 35-108, Bucharest 060023, Romania
| | - Carmen Mitan
- Institute of Organic Chemistry, Romanian Academy, 202B Spl. Independentei, P.O. Box 35-108, Bucharest 060023, Romania
| | - Hermanus CM Vosloo
- School of Physical and Chemical Sciences, North-West University, Hoffman Street, Potchefstroom 2520, South Africa
| | - Lionel Delaude
- Macromolecular Chemistry and Organic Catalysis, Institute of Chemistry (B6a), University of Liège, Sart Tilman, Liège 4000, Belgium
| | - Albert Demonceau
- Macromolecular Chemistry and Organic Catalysis, Institute of Chemistry (B6a), University of Liège, Sart Tilman, Liège 4000, Belgium
| |
Collapse
|
15
|
Shintani R, Narui R, Tsutsumi Y, Hayashi S, Hayashi T. Design and synthesis of new chiral phosphorus-olefin bidentate ligands and their use in the rhodium-catalyzed asymmetric addition of organoboroxines to N-sulfonyl imines. Chem Commun (Camb) 2011; 47:6123-5. [PMID: 21537505 DOI: 10.1039/c1cc11823d] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Novel chiral phosphorus-olefin bidentate ligands have been synthesized in a few steps from a readily available enantiopure compound. These ligands have been applied to a rhodium-catalyzed asymmetric addition of organoboroxines to N-sulfonyl aldimines, achieving high yield and enantioselectivity.
Collapse
Affiliation(s)
- Ryo Shintani
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502, Japan.
| | | | | | | | | |
Collapse
|
16
|
Horne G, Wilson FX. Therapeutic Applications of Iminosugars: Current Perspectives and Future Opportunities. PROGRESS IN MEDICINAL CHEMISTRY 2011; 50:135-76. [DOI: 10.1016/b978-0-12-381290-2.00004-5] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
|
17
|
Delso I, Tejero T, Goti A, Merino P. Synthesis of d-arabinose-derived polyhydroxylated pyrrolidine, indolizidine and pyrrolizidine alkaloids. Total synthesis of hyacinthacine A2. Tetrahedron 2010. [DOI: 10.1016/j.tet.2009.12.030] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
18
|
Wang N, Zhang LH, Ye XS. A new synthetic access to bicyclic polyhydroxylated alkaloid analogues from pyranosides. Org Biomol Chem 2010; 8:2639-49. [DOI: 10.1039/b923180c] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
19
|
Szczepina MG, Zheng RB, Completo GC, Lowary TL, Pinto BM. STD-NMR studies suggest that two acceptor substrates for GlfT2, a bifunctional galactofuranosyltransferase required for the biosynthesis of Mycobacterium tuberculosis arabinogalactan, compete for the same binding site. Chembiochem 2009; 10:2052-9. [PMID: 19575371 DOI: 10.1002/cbic.200900202] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The mycobacterial cell wall is a complex architecture, which has, as its major structural component, a lipidated polysaccharide covalently bound to peptidoglycan. This structure, termed the mycolyl-arabinogalactan-peptidoglycan complex, possesses a core galactan moiety composed of approximately 30 galactofuranosyl (Galf) resides attached via alternating beta-(1-->6) and beta-(1-->5) linkages. Recent studies have shown that the entire galactan is synthesized by the action of only two bifunctional galactofuranosyltransferases, GlfT1 and GlfT2. We report here saturation-transfer difference (STD) NMR spectroscopy studies with GlfT2 using two trisaccharide acceptor substrates, beta-D-Galf-(1-->6)-beta-D-Galf-(1-->5)-beta-D-Galf-O(CH(2))(7)CH(3) (2) and beta-D-Galf-(1-->5)-beta-D-Galf-(1-->6)-beta-D-Galf-O(CH(2))(7)CH(3) (3), as well as the donor substrate for the enzyme, UDP-Galf. Competition STD-NMR titration experiments and saturation transfer double difference (STDD) experiments with 2 and 3 were undertaken to explore the bifunctionality of this enzyme, in particular to answer whether one or two active sites are responsible for the formation of both beta-(1-->5)- and beta-(1-->6)-Galf linkages. It was demonstrated that 2 and 3 bind competitively at the same site; this suggests that GlfT2 has one active site pocket capable of catalyzing both beta-(1-->5) and beta-(1-->6) galactofuranosyl transfer reactions. The addition of UDP-Galf to GlfT2 in the presence of either 2 or 3 generated a tetrasaccharide product; this indicates that the enzyme was catalytically active under the conditions at which the STD-NMR experiments were carried out.
Collapse
Affiliation(s)
- Monica G Szczepina
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia (Canada)
| | | | | | | | | |
Collapse
|
20
|
van Otterlo WAL, de Koning CB. Metathesis in the synthesis of aromatic compounds. Chem Rev 2009; 109:3743-82. [PMID: 19618929 DOI: 10.1021/cr900178p] [Citation(s) in RCA: 247] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Willem A L van Otterlo
- Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand, PO Wits 2050, South Africa.
| | | |
Collapse
|
21
|
|
22
|
Doddi VR, Kokatla HP, Pal APJ, Basak RK, Vankar YD. Synthesis of Hybrids of D-Glucose and D-Galactose with Pyrrolidine-Based Iminosugars as Glycosidase Inhibitors. European J Org Chem 2008. [DOI: 10.1002/ejoc.200800770] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
23
|
Desvergnes S, Vallée Y, Py S. Novel Polyhydroxylated Cyclic Nitrones and N-Hydroxypyrrolidines through BCl3-Mediated Deprotection. Org Lett 2008; 10:2967-70. [DOI: 10.1021/ol8007759] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Stéphanie Desvergnes
- Département de Chimie Moléculaire (SERCO) UMR-5250, ICMG FR-2607, CNRS - Université Joseph Fourier, BP 53, 38041 Grenoble Cedex 09, France
| | - Yannick Vallée
- Département de Chimie Moléculaire (SERCO) UMR-5250, ICMG FR-2607, CNRS - Université Joseph Fourier, BP 53, 38041 Grenoble Cedex 09, France
| | - Sandrine Py
- Département de Chimie Moléculaire (SERCO) UMR-5250, ICMG FR-2607, CNRS - Université Joseph Fourier, BP 53, 38041 Grenoble Cedex 09, France
| |
Collapse
|
24
|
Development of a coupled spectrophotometric assay for GlfT2, a bifunctional mycobacterial galactofuranosyltransferase. Carbohydr Res 2008; 343:2130-9. [PMID: 18423586 DOI: 10.1016/j.carres.2008.03.023] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2008] [Revised: 03/13/2008] [Accepted: 03/17/2008] [Indexed: 11/22/2022]
Abstract
As a key constituent of their protective cell wall all mycobacteria produce a large structural component, the mycolyl-arabinogalactan (mAG) complex, which has at its core a galactan moiety of alternating beta-(1-->5) and beta-(1-->6) galactofuranosyl residues. Galactan biosynthesis is essential for mycobacterial viability and thus inhibitors of the enzymes involved in its assembly are potential drugs for the treatment of mycobacterial diseases, including tuberculosis. Only two galactofuranosyltransferases, GlfT1 and GlfT2, are responsible for the biosynthesis of the entire galactan domain of the mAG and we report here the first high-throughput assay for GlfT2. Successful implementation of the assay required the synthesis of multi-milligram amounts of the donor for the enzyme, UDP-Galf, 1, which was achieved using a chemoenzymatic approach. We also describe an improved expression system for GlfT2, which provides a larger amount of active protein for the assay. Kinetic analysis of 1 and a known trisaccharide acceptor for the enzyme, 2, have been carried out and the apparent K(m) and k(cat) values obtained for the latter are in agreement with those obtained using a previously reported radiochemical assay. The assay has been implemented in 384-well microtiter plates, which will facilitate the screening of large numbers of potential GlfT2 inhibitors, with possible utility as novel anti-TB drugs.
Collapse
|
25
|
|
26
|
Doddi VR, Vankar YD. Synthesis of Pyrrolidine-Based Imino Sugars as Glycosidase Inhibitors. European J Org Chem 2007. [DOI: 10.1002/ejoc.200700719] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
27
|
Rose NL, Completo GC, Lin SJ, McNeil M, Palcic MM, Lowary TL. Expression, purification, and characterization of a galactofuranosyltransferase involved in Mycobacterium tuberculosis arabinogalactan biosynthesis. J Am Chem Soc 2007; 128:6721-9. [PMID: 16704275 DOI: 10.1021/ja058254d] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The major structural component of the cell wall of Mycobacterium tuberculosis is a lipidated polysaccharide, the mycoyl-arabinogalactan-peptidoglycan (mAGP) complex. This glycoconjugate plays a key role in the survival of the organism, and thus, enzymes involved in its biosynthesis have attracted attention as sites for drug action. At the core of the mAGP is a galactan composed of D-galactofuranose residues attached via alternating beta-(1-->5) and beta-(1-->6) linkages. A single enzyme, glfT, has been shown to synthesize both glycosidic linkages. We report here the first high-level expression and purification of glfT by expression of the Rv3808c gene in Escherichia coli C41(DE3). Following a three-step purification procedure, 3-7 mg of protein of >95% purity was isolated from each liter of culture. We subsequently probed the substrate specificity of glfT by evaluating a panel of potential mono- and oligosaccharide substrates and demonstrated, for the first time, that trisaccharides are better substrates than disaccharides and that one disaccharide, in which the terminal D-galactofuranose residue is replaced with an L-arabinofuranose moiety, is a weak substrate. Kinetic characterization of the enzyme using four of the oligosaccharide acceptors gave K(m) values ranging from 204 microM to 1.7 mM. Through the use of NMR spectroscopy and mass spectrometry, we demonstrated that this recombinant enzyme, like the wild-type protein, is bifunctional and can synthesize both beta-(1-->6) and beta-(1-->5)-linkages in an alternating fashion. Access to purified glfT is expected to facilitate the development of high-throughput assays for the identification of inhibitors of the enzyme, which are potential antituberculosis agents.
Collapse
Affiliation(s)
- Natisha L Rose
- Department of Chemistry, University of Alberta, Edmonton, AB T6G 2G2, Canada
| | | | | | | | | | | |
Collapse
|
28
|
Compain P. Olefin Metathesis of Amine-Containing Systems: Beyond the Current Consensus. Adv Synth Catal 2007. [DOI: 10.1002/adsc.200700161] [Citation(s) in RCA: 144] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
29
|
Synthesis of acyclic galactitol- and lyxitol-aminophosphonates as inhibitors of UDP-galactopyranose mutase. Tetrahedron Lett 2007. [DOI: 10.1016/j.tetlet.2007.04.113] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
30
|
Herndon JW. The chemistry of the carbon–transition metal double and triple bond: Annual survey covering the year 2005. Coord Chem Rev 2007. [DOI: 10.1016/j.ccr.2006.11.002] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
31
|
Schomaker JM, Bhattacharjee S, Yan J, Borhan B. Diastereomerically and Enantiomerically Pure 2,3-Disubstituted Pyrrolidines from 2,3-Aziridin-1-ols Using a Sulfoxonium Ylide: A One-Carbon Homologative Relay Ring Expansion. J Am Chem Soc 2007; 129:1996-2003. [PMID: 17256932 DOI: 10.1021/ja065833p] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
An ylide-based aza-Payne rearrangement of 2,3-aziridin-1-ols leads to an efficient process for the preparation of pyrrolidines. The aza-Payne rearrangement under basic reaction conditions favors the formation of epoxy amines. Subsequent nucleophilic attack of the epoxide by the ylide yields a bis-anion, which upon a 5-exo-tet ring-closure yields the desired pyrrolidine, thus completing the relay of the three-membered to the five-membered nitrogen-containing ring system. This process takes place with complete transfer of stereochemical fidelity and can be applied to sterically hindered aziridinols.
Collapse
Affiliation(s)
- Jennifer M Schomaker
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
| | | | | | | |
Collapse
|
32
|
Liautard V, Desvergnes V, Martin OR. Stereoselective synthesis of alpha-C-Substituted 1,4-dideoxy-1,4-imino-D-galactitols. Toward original UDP-Galf mimics via cross-metathesis. Org Lett 2006; 8:1299-302. [PMID: 16562876 DOI: 10.1021/ol053078z] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
[reaction: see text] Various alpha-C-substituted 1,4-dideoxy-1,4-imino-d-galactitols were prepared efficiently from 1-O-acetyl-2,3,5,6-tetra-O-benzyl-d-glucofuranose by a four-step sequence involving as the key step the highly syn-selective TMSOTf-catalyzed addition of silylated nucleophiles to a glycofuranosylamine. Cross-metathesis of the alpha-C-allylated iminogalactofuranose derivative with an original uridin-5'-yl vinylphosphonate led to novel UDP-galactofuranose mimics. Such compounds are of interest as potential inhibitors of the mycobacterial galactan biosynthesis pathway.
Collapse
Affiliation(s)
- Virginie Liautard
- Institut de Chimie Organique et Analytique, UMR 6005, Université d'Orléans-CNRS Rue de Chartres, BP 6759, F-45067 Orléans Cedex 2, France
| | | | | |
Collapse
|
33
|
Dougherty AM, McDonald FE, Liotta DC, Moody SJ, Pallas DC, Pack CD, Merrill AH. Synthesis of 1-deoxysphingosine derivatives with conformationally restricted pyrrolidinediol head groups. Org Lett 2006; 8:649-52. [PMID: 16468733 PMCID: PMC4604444 DOI: 10.1021/ol052839v] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
[structure: see text] A family of cyclic 1-deoxysphingolipid derivatives of structure 4 has been designed and synthesized, which may serve as tumorigenesis suppressors for various cancers. Compound 4 is a second-generation analogue developed from sphingosine (1), in which a hydroxyl substituent is moved from C1 to C5 and a methylene is added for conformational rigidity between the C2-nitrogen substituent and C4. The synthetic chemistry for pyrrolidine ring closure at C3-C4 features ring-closing metathesis followed by hydroboration-oxidation.
Collapse
Affiliation(s)
| | | | | | - Steven J. Moody
- Department of Biochemistry, and Winship Cancer Institute, Emory University
| | - David C. Pallas
- Department of Biochemistry, and Winship Cancer Institute, Emory University
| | | | | |
Collapse
|
34
|
Synthesis of oxepine-, oxocine- and azepine-annulated carbazole derivatives by combined Claisen rearrangement and diene/enyne metathesis. Tetrahedron Lett 2006. [DOI: 10.1016/j.tetlet.2006.07.045] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
35
|
Moonen K, Dieltiens N, Stevens CV. Synthesis of 2-Phosphonopyrroles via a One-Pot RCM/Oxidation Sequence. J Org Chem 2006; 71:4006-9. [PMID: 16674086 DOI: 10.1021/jo060160e] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A four-step synthesis of 2-phosphonopyrroles is presented starting from suitable aldehydes. The key step in the synthesis involves a one-pot ring-closing metathesis/oxidation sequence of a functionalized alpha-aminoalkenyl phosphonate. Notwithstanding the presence of a nucleophilic nitrogen atom and high substitution patterns in the substrate, the results of the RCM reaction are excellent using mild reaction conditions. Furthermore, a synergism is observed between the RCM catalyst and the oxidizing agent, causing higher oxidation rates and allowing reaction for substrates that normally fail to ring close under standard RCM conditions.
Collapse
Affiliation(s)
- Kristof Moonen
- Research Group SynBioC, Department of Organic Chemistry, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, B-9000 Ghent, Belgium.
| | | | | |
Collapse
|