1
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Kumar N, Yadav M, Kashyap S. Reagent-controlled chemo/stereoselective glycosylation of ʟ-fucal to access rare deoxysugars. Carbohydr Res 2024; 535:108992. [PMID: 38091695 DOI: 10.1016/j.carres.2023.108992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2023] [Revised: 11/22/2023] [Accepted: 11/22/2023] [Indexed: 01/14/2024]
Abstract
2,6-Dideoxy sugars constitute an important class of anticancer antibiotics natural products and serve as essential medicinal tools for carbohydrate-based drug discovery and vaccine development. In particular, 2-deoxy ʟ-fucose or ʟ-oliose is a rare sugar and vital structural motif of several potent antifungal and immunosuppressive bioactive molecules. Herein, we devised a reagent-controlled stereo and chemoselective activation of ʟ-fucal, enabling the distinctive glycosylation pathways to access the rare ʟ-oliose and 2,3-unsaturated ʟ-fucoside. The milder oxo-philic Bi(OTf)3 catalyst induced the direct 1,2-addition predominantly, whereas B(C6F5)3 promoted the allylic Ferrier-rearrangement of the enol-ether moiety in ʟ-fucal glycal donor, distinguishing the competitive mechanisms. The reagent-tunable modular approach is highly advantageous, employing greener catalysts and atom-economical transformations, expensive ligand/additive-free, and probed for a diverse range of substrates comprising monosaccharides, amino-acids, bioactive natural products, and drug scaffolds embedded with susceptible or labile functionalities.
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Affiliation(s)
- Nitin Kumar
- Carbohydrate Chemistry Research Laboratory (CCRL), Department of Chemistry, Malaviya National Institute of Technology Jaipur (MNITJ), Jaipur, 302017, India
| | - Monika Yadav
- Carbohydrate Chemistry Research Laboratory (CCRL), Department of Chemistry, Malaviya National Institute of Technology Jaipur (MNITJ), Jaipur, 302017, India
| | - Sudhir Kashyap
- Carbohydrate Chemistry Research Laboratory (CCRL), Department of Chemistry, Malaviya National Institute of Technology Jaipur (MNITJ), Jaipur, 302017, India.
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2
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Mukherji A, Rotta MKV, Sarmah BK, Kancharla PK. Influence of Various Silyl Protecting Groups on Stereoselective 2-Deoxyrhamnosylation. J Org Chem 2023; 88:245-260. [PMID: 36524596 DOI: 10.1021/acs.joc.2c02285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The influence of various silyl protecting groups on 2-deoxyrhamnosylation using 2-deoxyrhamnosyl acetates, thioglycosides, and (p-methoxyphenyl)vinylbenzoate (PMPVB) donors has been presented. C-Glycosylation reactions reveal that tert-butyldimethylsilyl (TBDMS), triisopropylsilyl (TIPS), and tert-butyldiphenylsilyl (TBDPS) silyl protected rhamnosyl oxocarbenium ions have no facial selectivity except for the conformationally (4H3) locked tetraisopropyldisiloxane (TIPDS) protected rhamnose donor, which provides complete α-selectivity. However, TBDPS protected rhamnosyl donors are found to be superior protecting groups for α-stereoselective O-glycosylation reactions with various acceptors. The observed results are found consistent across donors and donor activation conditions. Most importantly, the study was conducted at room temperature unlike the other energy-intensive low-temperature studies and was bound to have more practical utility. The outcomes have been explained using kinetic and thermodynamic analyses.
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Affiliation(s)
- Ananya Mukherji
- Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati, Assam 781039, India
| | - Mahendra K V Rotta
- Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati, Assam 781039, India
| | - Bikash K Sarmah
- Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati, Assam 781039, India
| | - Pavan K Kancharla
- Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati, Assam 781039, India
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3
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Lin PC, Lin ZP, Chen PY, Hsieh MT, Lin HC. New metal-free one-pot synthesis of α-2-deoxy-Ulosides by microwave-assisted double Michael Addition of β-enamino ketones. Carbohydr Res 2023; 523:108712. [PMID: 36423508 DOI: 10.1016/j.carres.2022.108712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 11/03/2022] [Accepted: 11/04/2022] [Indexed: 11/18/2022]
Abstract
New metal-free one-pot synthesis of α-2-deoxy-ulosides in moderate to good yields by microwave-assisted double Michael addition of various O-nucleophiles to β-enamino ketones in the presence of 12 N HCl. These glycosyl additions occurred with high α-stereoselectivity and were complete in 10-25 min in 51-93% yield. In addition, high α-stereoselectivity was also observed when S-nucleophiles were examined.
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Affiliation(s)
- Pin-Chun Lin
- Graduate Institute of Pharmaceutical Chemistry, China Medical University, No. 91, Hsueh-Shih Rd., Taichung, 40402, Taiwan
| | - Zi-Ping Lin
- Graduate Institute of Pharmaceutical Chemistry, China Medical University, No. 91, Hsueh-Shih Rd., Taichung, 40402, Taiwan
| | - Po-Yen Chen
- School of Pharmacy, China Medical University, No. 91, Hsueh-Shih Rd., Taichung, 40402, Taiwan
| | - Min-Tsang Hsieh
- School of Pharmacy, China Medical University, No. 91, Hsueh-Shih Rd., Taichung, 40402, Taiwan; Chinese Medicinal Research and Development Center, China Medical University Hospital, No. 2, Yude Rd., Taichung, 40447, Taiwan
| | - Hui-Chang Lin
- School of Pharmacy, China Medical University, No. 91, Hsueh-Shih Rd., Taichung, 40402, Taiwan; Graduate Institute of Pharmaceutical Chemistry, China Medical University, No. 91, Hsueh-Shih Rd., Taichung, 40402, Taiwan.
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4
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Mukherji A, Addanki RB, Halder S, Kancharla PK. Sterically Strained Brønsted Pair Catalysis by Bulky Pyridinium Salts: Direct Stereoselective Synthesis of 2-Deoxy and 2,6-Dideoxy-β-thioglycosides from Glycals. J Org Chem 2021; 86:17226-17243. [PMID: 34794312 DOI: 10.1021/acs.joc.1c02305] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A sterically strained ionic Brønsted pair complex obtained from a sterically bulky base 2,4,6-tri-tert-butylpyridine and hydrochloric acid imbues unusual reactivity to the anionic chloride. The complete shielding of the cationic [N-H]+ by the bulky ortho-tert-butyl groups weakens the possible hydrogen-bonding interactions with the chloride anion, and the [N-H]+···Cl- distance is unusually longer (3.10 Å). This results in strained/frustrated electrostatic interactions between the ion-pair, thus infusing an increased reactivity in both of the ions, which results in the activation of a third molecule like thiol via hydrogen-bonding. This intriguing weak interaction-based reactivity has been utilized to develop an organocatalytic synthesis of 2-deoxy-β-thioglycosides from glycals. While the 1H NMR studies showcase the diamagnetic activation of thiols in the presence of the catalyst, the electron paramagnetic resonance (EPR) studies reveal the generation of a radical species that suggests a possible frustrated radical pair catalysis. Besides, IR spectroscopic studies explain the intriguing influence of size/charge density of the anion on the solvation-insusceptible, cationic [TTBPyH]+ and on the observed reactivity.
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Affiliation(s)
- Ananya Mukherji
- Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati, Assam 781039, India
| | - Rupa Bai Addanki
- Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati, Assam 781039, India
| | - Suvendu Halder
- Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati, Assam 781039, India
| | - Pavan K Kancharla
- Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati, Assam 781039, India
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5
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Suh CE, Carder HM, Wendlandt AE. Selective Transformations of Carbohydrates Inspired by Radical-Based Enzymatic Mechanisms. ACS Chem Biol 2021; 16:1814-1828. [PMID: 33988380 DOI: 10.1021/acschembio.1c00190] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Enzymes are a longstanding source of inspiration for synthetic reaction development. However, enzymatic reactivity and selectivity are frequently untenable in a synthetic context, as the principles that govern control in an enzymatic setting often do not translate to small molecule catalysis. Recent synthetic methods have revealed the viability of using small molecule catalysts to promote highly selective radical-mediated transformations of minimally protected sugar substrates. These transformations share conceptual similarities with radical SAM enzymes found in microbial carbohydrate biosynthesis and present opportunities for synthetic chemists to access microbial and unnatural carbohydrate building blocks without the need for protecting groups or lengthy synthetic sequences. Here, we highlight strategies through which radical reaction pathways can enable the site-, regio-, and diastereoselective transformation of minimally protected carbohydrates in both synthetic and enzymatic systems.
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Affiliation(s)
- Carolyn E. Suh
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Hayden M. Carder
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Alison E. Wendlandt
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
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6
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Li X, Ma Z, Liu R, Hurevich M, Yang Y. Photolabile Protecting
Group‐Mediated
Synthesis of
2‐Deoxy‐Glycosides. CHINESE J CHEM 2021. [DOI: 10.1002/cjoc.202100477] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Xiaoqian Li
- Shanghai Key Laboratory of New Drug Design, Engineering Research Center of Pharmaceutical Process Chemistry, Ministry of Education School of Pharmacy East China University of Science and Technology, 130 Meilong Road Shanghai 200237 China
| | - Zhi Ma
- Shanghai Key Laboratory of New Drug Design, Engineering Research Center of Pharmaceutical Process Chemistry, Ministry of Education School of Pharmacy East China University of Science and Technology, 130 Meilong Road Shanghai 200237 China
| | - Rongkun Liu
- Shanghai Key Laboratory of New Drug Design, Engineering Research Center of Pharmaceutical Process Chemistry, Ministry of Education School of Pharmacy East China University of Science and Technology, 130 Meilong Road Shanghai 200237 China
| | - Mattan Hurevich
- Institute of Chemistry Safra Campus, Givat Ram, Hebrew University of Jerusalem 91904 Israel
| | - You Yang
- Shanghai Key Laboratory of New Drug Design, Engineering Research Center of Pharmaceutical Process Chemistry, Ministry of Education School of Pharmacy East China University of Science and Technology, 130 Meilong Road Shanghai 200237 China
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7
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Yeh YC, Kim HJ, Liu HW. Mechanistic Investigation of 1,2-Diol Dehydration of Paromamine Catalyzed by the Radical S-Adenosyl-l-methionine Enzyme AprD4. J Am Chem Soc 2021; 143:5038-5043. [PMID: 33784078 DOI: 10.1021/jacs.1c00076] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
AprD4 is a radical S-adenosyl-l-methionine (SAM) enzyme catalyzing C3'-deoxygenation of paromamine to form 4'-oxo-lividamine. It is the only 1,2-diol dehydratase in the radical SAM enzyme superfamily that has been identified and characterized in vitro. The AprD4 catalyzed 1,2-diol dehydration is a key step in the biosynthesis of several C3'-deoxy-aminoglycosides. While the regiochemistry of the hydrogen atom abstraction catalyzed by AprD4 has been established, the mechanism of the subsequent chemical transformation remains not fully understood. To investigate the mechanism, several substrate analogues were synthesized and their fates upon incubation with AprD4 were analyzed. The results support a mechanism involving formation of a ketyl radical intermediate followed by direct elimination of the C3'-hydroxyl group rather than that of a gem-diol intermediate generated via 1,2-migration of the C3'-hydroxyl group to C4'. The stereochemistry of hydrogen atom incorporation after radical-mediated dehydration was also established.
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Affiliation(s)
- Yu-Cheng Yeh
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
| | - Hak Joong Kim
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
| | - Hung-Wen Liu
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States.,Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy, University of Texas at Austin, Austin, Texas 78712, United States
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8
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Wang C, Liang H, Hang Z, Wang ZY, Xie Q, Xue W. Lewis acid/base pair as a catalytic system for α-stereoselective synthesis of 2-deoxyglycosides through the addition of alcohols to glycals. Tetrahedron Lett 2020. [DOI: 10.1016/j.tetlet.2020.152643] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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9
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Jiang N, Dong Y, Sun G, Yang G, Wang Q, Zhang J. Core‐Shell Fe
3
O
4
@Carbon@SO
3
H: A Powerful Recyclable Catalyst for the Synthesis of α‐2‐Deoxygalactosides. ChemistrySelect 2020. [DOI: 10.1002/slct.202000089] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- Nan Jiang
- School of Chemistry and Molecular EngineeringEast China Normal University Shanghai 200241 P. R. of China
| | - Youxian Dong
- School of Chemistry and Molecular EngineeringEast China Normal University Shanghai 200241 P. R. of China
| | - Guosheng Sun
- School of Chemistry and Molecular EngineeringEast China Normal University Shanghai 200241 P. R. of China
| | - Guofang Yang
- School of Chemistry and Molecular EngineeringEast China Normal University Shanghai 200241 P. R. of China
| | - Qingbing Wang
- School of Chemistry and Molecular EngineeringEast China Normal University Shanghai 200241 P. R. of China
| | - Jianbo Zhang
- School of Chemistry and Molecular EngineeringEast China Normal University Shanghai 200241 P. R. of China
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10
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Smajlagic I, Guest M, Durán R, Herrera B, Dudding T. Mechanistic Insight toward Understanding the Role of Charge in Thiourea Organocatalysis. J Org Chem 2020; 85:585-593. [PMID: 31790584 DOI: 10.1021/acs.joc.9b02682] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Pyranylation and glycosylation are pivotal for accessing a myriad of natural products, pharmaceuticals, and drug candidates. Catalytic approaches for enabling these transformations are of utmost importance and integral to advancing this area of synthesis. In exploring this chemical space, a combined experimental and computational mechanistic study of pyranylation and 2-deoxygalactosylation catalyzed by a cationic thiourea organocatalyst is reported. To this end, a thiourea-cyclopropenium organocatalyst was employed as a model system in combination with an arsenal of mechanistic techniques, including 13C kinetic isotope effect experiments, deuterated labeling studies, variable-temperature 1H NMR spectroscopy, and density functional theory calculations. From these studies, two distinct reaction pathways were identified for this transformation corresponding to either dual hydrogen bond (H-bond) activation or Brønsted acid catalysis. The former involving thiourea orchestrated bifurcated hydrogen bonding proceeded in an asynchronous concerted fashion. In contrast, the latter stepwise mechanism involving Brønsted acid catalysis hinged upon the formation of an oxocarbenium intermediate accompanied by subsequent alcohol addition.
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Affiliation(s)
- Ivor Smajlagic
- Brock University , 1812 Sir Isaac Brock Way , St. Catharines , ON L2S 3A1 , Canada
| | - Matt Guest
- Brock University , 1812 Sir Isaac Brock Way , St. Catharines , ON L2S 3A1 , Canada
| | - Rocío Durán
- Laboratorio de Química Teórica Computacional (QTC), Departamento de Química-Física, Facultad de Química y de Farmacia , Pontificia Universidad Católica de Chile , Av. Vicuña Mackenna 4860 , Macul, Santiago , Chile
| | - Barbara Herrera
- Laboratorio de Química Teórica Computacional (QTC), Departamento de Química-Física, Facultad de Química y de Farmacia , Pontificia Universidad Católica de Chile , Av. Vicuña Mackenna 4860 , Macul, Santiago , Chile
| | - Travis Dudding
- Brock University , 1812 Sir Isaac Brock Way , St. Catharines , ON L2S 3A1 , Canada
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11
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Tatina MB, Moussa Z, Xia M, Judeh ZMA. Perfluorophenylboronic acid-catalyzed direct α-stereoselective synthesis of 2-deoxygalactosides from deactivated peracetylated d-galactal. Chem Commun (Camb) 2019; 55:12204-12207. [PMID: 31549691 DOI: 10.1039/c9cc06151g] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Perfluorophenylboronic acid 1c catalyzes the direct stereoselective addition of alcohol nucleophiles to deactivated peracetylated d-galactal to give 2-deoxygalactosides in 55-88% yield with complete α-selectivity. The unprecedented results reported here also enable the synthesis of disaccharides containing the 2-deoxygalactose moiety directly from the deactivated peracetylated d-galactal. This convenient and metal-free glycosylation method works well with a wide range of alcohol nucleophiles as acceptors and tolerates a range of functional groups without the formation of the Ferrier byproduct and without the need for a large excess of nucleophiles or additives. The method is potentially useful for the synthesis of a variety of α-2-deoxygalactosides.
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Affiliation(s)
- Madhu Babu Tatina
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 637459, Singapore.
| | - Ziad Moussa
- Department of Chemistry, College of Science, United Arab Emirates University, 15551, United Arab Emirates
| | - Mengxin Xia
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 637459, Singapore.
| | - Zaher M A Judeh
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 637459, Singapore.
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12
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Ghosh T, Mukherji A, Kancharla PK. Sterically Hindered 2,4,6-Tri-tert-butylpyridinium Salts as Single Hydrogen Bond Donors for Highly Stereoselective Glycosylation Reactions of Glycals. Org Lett 2019; 21:3490-3495. [DOI: 10.1021/acs.orglett.9b00626] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Titli Ghosh
- Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati, Assam 781039, India
| | - Ananya Mukherji
- Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati, Assam 781039, India
| | - Pavan K. Kancharla
- Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati, Assam 781039, India
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13
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Sau A, Palo-Nieto C, Galan MC. Substrate-Controlled Direct α-Stereoselective Synthesis of Deoxyglycosides from Glycals Using B(C 6F 5) 3 as Catalyst. J Org Chem 2019; 84:2415-2424. [PMID: 30706711 PMCID: PMC6466476 DOI: 10.1021/acs.joc.8b02613] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
B(C6F5)3 enables the metal-free
unprecedented substrate-controlled direct α-stereoselective
synthesis of deoxyglycosides from glycals. 2,3-Unsaturated α-O-glycoside products are obtained with deactivated glycals
at 75 °C in the presence of the catalyst, while 2-deoxyglycosides
are formed using activated glycals that bear no leaving group at C-3
at lower temperatures. The reaction proceeds in good to excellent
yields via concomitant borane activation of glycal donor and nucleophile
acceptor. The method is exemplified with the synthesis of a series
of rare and biologically relevant glycoside analogues.
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Affiliation(s)
- Abhijit Sau
- School of Chemistry , University of Bristol , Cantock's Close, Bristol BS8 1TS , United Kingdom
| | - Carlos Palo-Nieto
- School of Chemistry , University of Bristol , Cantock's Close, Bristol BS8 1TS , United Kingdom
| | - M Carmen Galan
- School of Chemistry , University of Bristol , Cantock's Close, Bristol BS8 1TS , United Kingdom
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14
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Riegert AS, Thoden JB, Schoenhofen IC, Watson DC, Young NM, Tipton PA, Holden HM. Structural and Biochemical Investigation of PglF from Campylobacter jejuni Reveals a New Mechanism for a Member of the Short Chain Dehydrogenase/Reductase Superfamily. Biochemistry 2017; 56:6030-6040. [PMID: 29053280 DOI: 10.1021/acs.biochem.7b00910] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Within recent years it has become apparent that protein glycosylation is not limited to eukaryotes. Indeed, in Campylobacter jejuni, a Gram-negative bacterium, more than 60 of its proteins are known to be glycosylated. One of the sugars found in such glycosylated proteins is 2,4-diacetamido-2,4,6-trideoxy-α-d-glucopyranose, hereafter referred to as QuiNAc4NAc. The pathway for its biosynthesis, initiating with UDP-GlcNAc, requires three enzymes referred to as PglF, PglE, and PlgD. The focus of this investigation is on PglF, an NAD+-dependent sugar 4,6-dehydratase known to belong to the short chain dehydrogenase/reductase (SDR) superfamily. Specifically, PglF catalyzes the first step in the pathway, namely, the dehydration of UDP-GlcNAc to UDP-2-acetamido-2,6-dideoxy-α-d-xylo-hexos-4-ulose. Most members of the SDR superfamily contain a characteristic signature sequence of YXXXK where the conserved tyrosine functions as a catalytic acid or a base. Strikingly, in PglF, this residue is a methionine. Here we describe a detailed structural and functional investigation of PglF from C. jejuni. For this investigation five X-ray structures were determined to resolutions of 2.0 Å or better. In addition, kinetic analyses of the wild-type and site-directed variants were performed. On the basis of the data reported herein, a new catalytic mechanism for a SDR superfamily member is proposed that does not require the typically conserved tyrosine residue.
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Affiliation(s)
- Alexander S Riegert
- Department of Biochemistry, University of Wisconsin , Madison, Wisconsin 53706, United States
| | - James B Thoden
- Department of Biochemistry, University of Wisconsin , Madison, Wisconsin 53706, United States
| | - Ian C Schoenhofen
- National Research Council Canada, Human Health Therapeutics , Ottawa, Ontario K1A 0R6, Canada
| | - David C Watson
- National Research Council Canada, Human Health Therapeutics , Ottawa, Ontario K1A 0R6, Canada
| | - N Martin Young
- National Research Council Canada, Human Health Therapeutics , Ottawa, Ontario K1A 0R6, Canada
| | - Peter A Tipton
- Department of Biochemistry, University of Missouri , Columbia, Missouri 65211, United States
| | - Hazel M Holden
- Department of Biochemistry, University of Wisconsin , Madison, Wisconsin 53706, United States
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15
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Mahato S, Chatterjee R, Chakraborty Ghosal N, Majee A. Zwitterionic imidazolium salt: An efficient organocatalyst for tetrahydropyranylation of alcohols. SYNTHETIC COMMUN 2017. [DOI: 10.1080/00397911.2017.1356334] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Sachinta Mahato
- Department of Chemistry, Visva-Bharati (A Central University), Santiniketan, West Bengal, India
| | - Rana Chatterjee
- Department of Chemistry, Visva-Bharati (A Central University), Santiniketan, West Bengal, India
| | | | - Adinath Majee
- Department of Chemistry, Visva-Bharati (A Central University), Santiniketan, West Bengal, India
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16
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Iodosobenzene diacetate-Iodine and IBX-Iodine: Reagent systems for the synthesis of diastereomerically enriched 2-deoxy-2-iodoglycosyl acetates and 2-deoxy-2-iodoglycosyl ortho-iodobenzoates from protected glycals. Tetrahedron 2017. [DOI: 10.1016/j.tet.2017.06.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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17
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Zeng J, Xu Y, Wang H, Meng L, Wan Q. Recent progress on the synthesis of 2-deoxy glycosides. Sci China Chem 2017. [DOI: 10.1007/s11426-016-9010-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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18
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Sau A, Williams R, Palo‐Nieto C, Franconetti A, Medina S, Galan MC. Palladium-Catalyzed Direct Stereoselective Synthesis of Deoxyglycosides from Glycals. Angew Chem Int Ed Engl 2017; 56:3640-3644. [PMID: 28211228 PMCID: PMC5484376 DOI: 10.1002/anie.201612071] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Revised: 01/26/2017] [Indexed: 02/06/2023]
Abstract
Palladium(II) in combination with a monodentate phosphine ligand enables the unprecedented direct and α-stereoselective catalytic synthesis of deoxyglycosides from glycals. Initial mechanistic studies suggest that in the presence of N-phenyl-2-(di-tert-butylphosphino)pyrrole as the ligand, the reaction proceeds via an alkoxy palladium intermediate that increases the proton acidity and oxygen nucleophilicity of the alcohol. The method is demonstrated with a wide range of glycal donors and acceptors, including substrates bearing alkene functionalities.
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Affiliation(s)
- Abhijit Sau
- School of ChemistryUniversity of BristolCantock's CloseBristolBS8 1TSUK
| | - Ryan Williams
- School of ChemistryUniversity of BristolCantock's CloseBristolBS8 1TSUK
| | - Carlos Palo‐Nieto
- School of ChemistryUniversity of BristolCantock's CloseBristolBS8 1TSUK
| | | | - Sandra Medina
- School of ChemistryUniversity of BristolCantock's CloseBristolBS8 1TSUK
| | - M. Carmen Galan
- School of ChemistryUniversity of BristolCantock's CloseBristolBS8 1TSUK
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19
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Sau A, Williams R, Palo‐Nieto C, Franconetti A, Medina S, Galan MC. Palladium‐Catalyzed Direct Stereoselective Synthesis of Deoxyglycosides from Glycals. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201612071] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Abhijit Sau
- School of Chemistry University of Bristol Cantock's Close Bristol BS8 1TS UK
| | - Ryan Williams
- School of Chemistry University of Bristol Cantock's Close Bristol BS8 1TS UK
| | - Carlos Palo‐Nieto
- School of Chemistry University of Bristol Cantock's Close Bristol BS8 1TS UK
| | - Antonio Franconetti
- School of Chemistry University of Bristol Cantock's Close Bristol BS8 1TS UK
| | - Sandra Medina
- School of Chemistry University of Bristol Cantock's Close Bristol BS8 1TS UK
| | - M. Carmen Galan
- School of Chemistry University of Bristol Cantock's Close Bristol BS8 1TS UK
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20
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Palo-Nieto C, Sau A, Williams R, Galan MC. Cooperative Brønsted Acid-Type Organocatalysis for the Stereoselective Synthesis of Deoxyglycosides. J Org Chem 2016; 82:407-414. [PMID: 28004941 PMCID: PMC5309864 DOI: 10.1021/acs.joc.6b02498] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
A practical approach for the α-stereoselective synthesis of deoxyglycosides using cooperative Brønsted acid-type organocatalysis has been developed. The method is tolerant of a wide range of glycoside donors and acceptors, and its versatility is exemplified in the one-pot synthesis of a trisaccharide. Mechanistic studies suggest that thiourea-induced acid amplification of the chiral acid via H-bonding is key for the enhancement in reaction rate and yield, while stereocontrol is dependent on the chirality of the acid.
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Affiliation(s)
- Carlos Palo-Nieto
- School of Chemistry, University of Bristol , Cantock's Close, Bristol BS8 1TS, United Kingdom
| | - Abhijit Sau
- School of Chemistry, University of Bristol , Cantock's Close, Bristol BS8 1TS, United Kingdom
| | - Ryan Williams
- School of Chemistry, University of Bristol , Cantock's Close, Bristol BS8 1TS, United Kingdom
| | - M Carmen Galan
- School of Chemistry, University of Bristol , Cantock's Close, Bristol BS8 1TS, United Kingdom
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21
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Brenna E, Cannavale F, Crotti M, De Vitis V, Gatti FG, Migliazza G, Molinari F, Parmeggiani F, Romano D, Santangelo S. Synthesis of Enantiomerically Enriched 2-Hydroxymethylalkanoic Acids by Oxidative Desymmetrisation of Achiral 1,3-Diols Mediated byAcetobacter aceti. ChemCatChem 2016. [DOI: 10.1002/cctc.201601051] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Elisabetta Brenna
- Dipartimento di Chimica; Materiali ed Ingegneria Chimica “Giulio Natta” Politecnico di Milano; Via Mancinelli 7 20131 Milano Italy
- Istituto di Chimica del Riconoscimento Molecolare, C.N.R.; Via Mario Bianco, 9 20131 Milano Italy
| | - Flavia Cannavale
- Dipartimento di Chimica; Materiali ed Ingegneria Chimica “Giulio Natta” Politecnico di Milano; Via Mancinelli 7 20131 Milano Italy
| | - Michele Crotti
- Dipartimento di Chimica; Materiali ed Ingegneria Chimica “Giulio Natta” Politecnico di Milano; Via Mancinelli 7 20131 Milano Italy
| | - Valerio De Vitis
- University of Milan; Department of Food, Environmental and Nutritional Science (DeFENS); Via Mangiagalli 25 20133 Milano Italy
| | - Francesco G. Gatti
- Dipartimento di Chimica; Materiali ed Ingegneria Chimica “Giulio Natta” Politecnico di Milano; Via Mancinelli 7 20131 Milano Italy
| | - Gaia Migliazza
- Dipartimento di Chimica; Materiali ed Ingegneria Chimica “Giulio Natta” Politecnico di Milano; Via Mancinelli 7 20131 Milano Italy
| | - Francesco Molinari
- University of Milan; Department of Food, Environmental and Nutritional Science (DeFENS); Via Mangiagalli 25 20133 Milano Italy
| | - Fabio Parmeggiani
- Dipartimento di Chimica; Materiali ed Ingegneria Chimica “Giulio Natta” Politecnico di Milano; Via Mancinelli 7 20131 Milano Italy
| | - Diego Romano
- University of Milan; Department of Food, Environmental and Nutritional Science (DeFENS); Via Mangiagalli 25 20133 Milano Italy
| | - Sara Santangelo
- Dipartimento di Chimica; Materiali ed Ingegneria Chimica “Giulio Natta” Politecnico di Milano; Via Mancinelli 7 20131 Milano Italy
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22
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Qiu S, Zhang W, Sun G, Wang Z, Zhang J. A Facile and Direct Glycosidation Method for the Synthesis of 2-Deoxy α-Rhamnosides Catalyzed by Ferric Chloride. ChemistrySelect 2016. [DOI: 10.1002/slct.201600802] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Saifeng Qiu
- School of Chemistry and Molecular Engineering; East China Normal University; Shanghai 200241 P.R. China
| | - Wan Zhang
- School of Chemistry and Molecular Engineering; East China Normal University; Shanghai 200241 P.R. China
| | - Guosheng Sun
- School of Chemistry and Molecular Engineering; East China Normal University; Shanghai 200241 P.R. China
| | - Zhongfu Wang
- School of Life Sciences; Northwestern University; Xi'an, Shaanxi 710069 P.R. China
| | - Jianbo Zhang
- School of Chemistry and Molecular Engineering; East China Normal University; Shanghai 200241 P.R. China
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23
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Identification of a dTDP-rhamnose biosynthetic pathway that oscillates with the molting cycle in Caenorhabditis elegans. Biochem J 2016; 473:1507-21. [PMID: 27009306 PMCID: PMC4888466 DOI: 10.1042/bcj20160142] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Accepted: 03/23/2016] [Indexed: 01/08/2023]
Abstract
The rhamnose biosynthetic pathway, which is highly conserved across nematode species, was characterized in the nematode Caenorhabditis elegans. The pathway is up-regulated before each larval molt, suggesting that rhamnose biosynthesis plays a role in cuticle or surface coat synthesis. L-Rhamnose is a common component of cell-wall polysaccharides, glycoproteins and some natural products in bacteria and plants, but is rare in fungi and animals. In the present study, we identify and characterize a biosynthetic pathway for dTDP-rhamnose in Caenorhabditis elegans that is highly conserved across nematode species. We show that RML-1 activates glucose 1-phosphate (Glc-1-P) in the presence of either dTTP or UTP to yield dTDP-glucose or UDP-glucose, respectively. RML-2 is a dTDP-glucose 4,6-dehydratase, converting dTDP-glucose into dTDP-4-keto-6-deoxyglucose. Using mass spectrometry and NMR spectroscopy, we demonstrate that coincubation of dTDP-4-keto-6-deoxyglucose with RML-3 (3,5-epimerase) and RML-4 (4-keto-reductase) produces dTDP-rhamnose. RML-4 could only be expressed and purified in an active form through co-expression with a co-regulated protein, RML-5, which forms a complex with RML-4. Analysis of the sugar nucleotide pool in C. elegans established the presence of dTDP-rhamnose in vivo. Targeting the expression of the rhamnose biosynthetic genes by RNAi resulted in significant reductions in dTDP-rhamnose, but had no effect on the biosynthesis of a closely related sugar, ascarylose, found in the ascaroside pheromones. Therefore, the rhamnose and ascarylose biosynthetic pathways are distinct. We also show that transcriptional reporters for the rhamnose biosynthetic genes are expressed highly in the embryo, in the hypodermis during molting cycles and in the hypodermal seam cells specifically before the molt to the stress-resistant dauer larval stage. These expression patterns suggest that rhamnose biosynthesis may play an important role in hypodermal development or the production of the cuticle or surface coat during molting.
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24
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Balmond EI, Benito-Alifonso D, Coe DM, Alder RW, McGarrigle EM, Galan MC. A 3,4-trans-fused cyclic protecting group facilitates α-selective catalytic synthesis of 2-deoxyglycosides. Angew Chem Int Ed Engl 2014; 53:8190-4. [PMID: 24953049 PMCID: PMC4499252 DOI: 10.1002/anie.201403543] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Indexed: 11/09/2022]
Abstract
A practical approach has been developed to convert glucals and rhamnals into disaccharides or glycoconjugates with high α-selectivity and yields (77-97%) using a trans-fused cyclic 3,4-O-disiloxane protecting group and TsOH⋅H2O (1 mol%) as a catalyst. Control of the anomeric selectivity arises from conformational locking of the intermediate oxacarbenium cation. Glucals outperform rhamnals because the C6 side-chain conformation augments the selectivity.
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Affiliation(s)
- Edward I Balmond
- School of Chemistry, University of Bristol, Cantock's CloseBristol BS8 1TS (UK)
| | | | - Diane M Coe
- GlaxoSmithKline Medicines Research CentreGunnels Wood Road, Stevenage SG1 2NY (UK)
| | - Roger W Alder
- School of Chemistry, University of Bristol, Cantock's CloseBristol BS8 1TS (UK)
| | - Eoghan M McGarrigle
- Centre for Synthesis and Chemical Biology, UCD School of Chemistry & Chemical Biology, University College DublinBelfield, Dublin 4 (Ireland)
| | - M Carmen Galan
- School of Chemistry, University of Bristol, Cantock's CloseBristol BS8 1TS (UK)
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25
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Balmond EI, Benito-Alifonso D, Coe DM, Alder RW, McGarrigle EM, Galan MC. A 3,4-trans-Fused Cyclic Protecting Group Facilitates α-Selective Catalytic Synthesis of 2-Deoxyglycosides. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201403543] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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26
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Gómez AM, Lobo F, Uriel C, López JC. Recent Developments in the Ferrier Rearrangement. European J Org Chem 2013. [DOI: 10.1002/ejoc.201300798] [Citation(s) in RCA: 118] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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27
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Skariyachan S, Jayaprakash N, Bharadwaj N, Narayanappa R. Exploring insights for virulent gene inhibition of multidrug resistantSalmonella typhi,Vibrio cholerae, andStaphylococcus areusby potential phytoligands viain silicoscreening. J Biomol Struct Dyn 2013; 32:1379-95. [DOI: 10.1080/07391102.2013.819787] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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28
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Ding F, Cai S, William R, Liu XW. Pathways leading to 3-amino- and 3-nitro-2,3-dideoxy sugars: strategies and synthesis. RSC Adv 2013. [DOI: 10.1039/c3ra40595h] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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29
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The synthesis of 2-deoxy-α-d-glycosides from d-glycals catalyzed by TMSI and PPh3. Carbohydr Res 2012; 358:19-22. [DOI: 10.1016/j.carres.2012.06.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2012] [Revised: 05/05/2012] [Accepted: 06/04/2012] [Indexed: 11/18/2022]
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30
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Balmond EI, Coe DM, Galan MC, McGarrigle EM. α-Selective Organocatalytic Synthesis of 2-Deoxygalactosides. Angew Chem Int Ed Engl 2012; 51:9152-5. [DOI: 10.1002/anie.201204505] [Citation(s) in RCA: 131] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Indexed: 12/14/2022]
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31
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Balmond EI, Coe DM, Galan MC, McGarrigle EM. α-Selective Organocatalytic Synthesis of 2-Deoxygalactosides. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201204505] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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32
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pTSA/[bmim][BF4] Ionic Liquid: A Powerful Recyclable Catalytic System for the Synthesis of α-2-Deoxyglycosides. Top Catal 2012. [DOI: 10.1007/s11244-012-9847-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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33
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Ding F, William R, Cai S, Ma J, Liu XW. Direct and Stereoselective Synthesis of 1,3-cis-3- Arylsulphonaminodeoxydisaccharides and Oligosaccharides. J Org Chem 2012; 77:5245-54. [DOI: 10.1021/jo300791v] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Feiqing Ding
- Division of Chemistry and Biological Chemistry, School of
Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371
| | - Ronny William
- Division of Chemistry and Biological Chemistry, School of
Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371
| | - Shuting Cai
- Division of Chemistry and Biological Chemistry, School of
Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371
| | - Jimei Ma
- Division of Chemistry and Biological Chemistry, School of
Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371
| | - Xue-Wei Liu
- Division of Chemistry and Biological Chemistry, School of
Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371
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34
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Ding N, Chun Y, Zhang W, Li Y. Bromodimethylsulfonium Bromide Catalyzed Synthesis of Methyl 2-Dexoy-4,6-O-benzylidene Galactopyranoside from Galactal and the Rapid Route to 2,3- and 2,6-Dideoxygalactopyranoses. CHINESE J CHEM 2012. [DOI: 10.1002/cjoc.201180487] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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35
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Romo AJ, Liu HW. Mechanisms and structures of vitamin B(6)-dependent enzymes involved in deoxy sugar biosynthesis. BIOCHIMICA ET BIOPHYSICA ACTA 2011; 1814:1534-47. [PMID: 21315852 PMCID: PMC3115481 DOI: 10.1016/j.bbapap.2011.02.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2010] [Revised: 01/08/2011] [Accepted: 02/01/2011] [Indexed: 10/18/2022]
Abstract
PLP is well-regarded for its role as a coenzyme in a number of diverse enzymatic reactions. Transamination, deoxygenation, and aldol reactions mediated by PLP-dependent enzymes enliven and enrich deoxy sugar biosynthesis, endowing these compounds with unique structures and contributing to their roles as determinants of biological activity in many natural products. The importance of deoxy aminosugars in natural product biosynthesis has spurred several recent structural investigations of sugar aminotransferases. The structure of a PMP-dependent enzyme catalyzing the C-3 deoxygenation reaction in the biosynthesis of ascarylose was also determined. These studies, and the crystal structures they have provided, offer a wealth of new insights regarding the enzymology of PLP/PMP-dependent enzymes in deoxy sugar biosynthesis. In this review, we consider these recent achievements in the structural biology of deoxy sugar biosynthetic enzymes and the important implications they hold for understanding enzyme catalysis and natural product biosynthesis in general. This article is part of a Special Issue entitled: Pyridoxal Phosphate Enzymology.
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Affiliation(s)
- Anthony J. Romo
- Division of Medicinal Chemistry, College of Pharmacy, and Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712
| | - Hung-wen Liu
- Division of Medicinal Chemistry, College of Pharmacy, and Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712
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36
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Lin HC, Pan JF, Chen YB, Lin ZP, Lin CH. Stereoselective glycosylation of endo-glycals by microwave- and AlCl3-assisted catalysis. Tetrahedron 2011. [DOI: 10.1016/j.tet.2011.05.124] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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37
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Kharel MK, Lian H, Rohr J. Characterization of the TDP-D-ravidosamine biosynthetic pathway: one-pot enzymatic synthesis of TDP-D-ravidosamine from thymidine-5-phosphate and glucose-1-phosphate. Org Biomol Chem 2011; 9:1799-808. [PMID: 21264378 PMCID: PMC4482361 DOI: 10.1039/c0ob00854k] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ravidomycin V and related compounds, e.g., FE35A-B, exhibit potent anticancer activities against various cancer cell lines in the presence of visible light. The amino sugar moieties (D-ravidosamine and its analogues, respectively) in these molecules contribute to the higher potencies of ravidomycin and analogues when compared to closely related compounds with neutral or branched sugars. Within the ravidomycin V biosynthetic gene cluster, five putative genes encoding NDP-D-ravidosamine biosynthetic enzymes were identified. Through the activities of the isolated enzymes in vitro, it is demonstrated that ravD, ravE, ravIM, ravAMT and ravNMT encode TDP-D-glucose synthase, TDP-4-keto-6-deoxy-D-glucose-4,6-dehydratase, TDP-4-keto-6-deoxy-D-glucose-3,4-ketoisomerase, TDP-3-keto-6-deoxy-D-galactose-3-aminotransferase, and TDP-3-amino-3,6-dideoxy-D-galactose-N,N-dimethyl-transferase, respectively. A protocol for a one-pot enzymatic synthesis of TDP-D-ravidosamine has been developed. The results presented here now set the stage to produce TDP-D-ravidosamine routinely for glycosylation studies.
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Affiliation(s)
- Madan K. Kharel
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536-0596, USA
| | - Hui Lian
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536-0596, USA
| | - Jürgen Rohr
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536-0596, USA
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38
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Sasaki E, Liu HW. Mechanistic studies of the biosynthesis of 2-thiosugar: evidence for the formation of an enzyme-bound 2-ketohexose intermediate in BexX-catalyzed reaction. J Am Chem Soc 2011; 132:15544-6. [PMID: 20961106 DOI: 10.1021/ja108061c] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The first mechanistic insight into 2-thiosugar production in an angucycline-type antibiotic, BE-7585A, is reported. d-Glucose 6-phosphate was identified as the substrate for the putative thiosugar biosynthetic protein, BexX, by trapping the covalently bonded enzyme-substrate intermediate. The site-specific modification at K110 residue was determined by mutagenesis studies and LC-MS/MS analysis. A key intermediate carrying a keto functionality was confirmed to exist in the enzyme-substrate complex. These results suggest that the sulfur insertion mechanism in 2-thiosugar biosynthesis shares similarities with that for thiamin biosynthesis.
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Affiliation(s)
- Eita Sasaki
- Division of Medicinal Chemistry, College of Pharmacy, and Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712, United States
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39
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Rale M, Schneider S, Sprenger GA, Samland AK, Fessner WD. Broadening deoxysugar glycodiversity: natural and engineered transaldolases unlock a complementary substrate space. Chemistry 2011; 17:2623-32. [PMID: 21290439 DOI: 10.1002/chem.201002942] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2010] [Indexed: 11/06/2022]
Abstract
The majority of prokaryotic drugs are produced in glycosylated form, with the deoxygenation level in the sugar moiety having a profound influence on the drug's bioprofile. Chemical deoxygenation is challenging due to the need for tedious protective group manipulations. For a direct biocatalytic de novo generation of deoxysugars by carboligation, with regiocontrol over deoxygenation sites determined by the choice of enzyme and aldol components, we have investigated the substrate scope of the F178Y mutant of transaldolase B, TalB(F178Y), and fructose 6-phosphate aldolase, FSA, from E. coli against a panel of variously deoxygenated aldehydes and ketones as aldol acceptors and donors, respectively. Independent of substrate structure, both enzymes catalyze a stereospecific carboligation resulting in the D-threo configuration. In combination, these enzymes have allowed the preparation of a total of 22 out of 24 deoxygenated ketose-type products, many of which are inaccessible by available enzymes, from a [3×8] substrate matrix. Although aliphatic and hydroxylated aliphatic aldehydes were good substrates, D-lactaldehyde was found to be an inhibitor possibly as a consequence of inactive substrate binding to the catalytic Lys residue. A 1-hydroxy-2-alkanone moiety was identified as a common requirement for the donor substrate, whereas propanone and butanone were inactive. For reactions involving dihydroxypropanone, TalB(F178Y) proved to be the superior catalyst, whereas for reactions involving 1-hydroxybutanone, FSA is the only choice; for conversions using hydroxypropanone, both TalB(F178Y) and FSA are suitable. Structure-guided mutagenesis of Ser176 to Ala in the distant binding pocket of TalB(F178Y), in analogy with the FSA active site, further improved the acceptance of hydroxypropanone. Together, these catalysts are valuable new entries to an expanding toolbox of biocatalytic carboligation and complement each other well in their addressable constitutional space for the stereospecific preparation of deoxysugars.
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Affiliation(s)
- Madhura Rale
- Institut für Organische Chemie und Biochemie, Technische Universität Darmstadt, Darmstadt, Germany
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40
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Huang W, Llano J, Gauld JW. Redox mechanism of glycosidic bond hydrolysis catalyzed by 6-phospho-alpha-glucosidase: a DFT study. J Phys Chem B 2010; 114:11196-206. [PMID: 20698522 DOI: 10.1021/jp102399h] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Glycosidic bonds are remarkably resistant to cleavage by chemical hydrolysis. Glycoside hydrolases catalyze their selective hydrolysis in oligosaccharides, polysaccharides, and glycoconjugates by following nonredox catalytic pathways or a net redox-neutral catalytic pathway using NAD(+) and divalent metal ions as cofactors. GlvA (6-phospho-alpha-glucosidase) is a glycosidase belonging to family GH4 and follows a regioselective redox-neutral mechanism of glycosidic-bond hydrolysis that favors alpha- over beta-glycosides. Its proposed catalytic mechanism can be divided into two half-reactions: the first one activates the glucopyranose ring by successively forming intermediates that are oxidized at the 3-, 2-, and 1-positions of the ring, which ultimately facilitate the heterolytic deglycosylation. The second half-reaction is essentially the reverse of the first half-reaction, beginning with the pyranose ring hydroxylation at the anomeric carbon, and it is followed by 3-reduction and regeneration of the active forms of the catalytic site and its cofactors. We investigated the NAD(+)-dependent redox mechanism of glycosidic bond hydrolysis as catalyzed by GlvA through the combined application of density functional theory and a self-consistent reaction field to a large active-site model obtained from the crystallographic structure of the enzyme, then we applied natural bond orbital and second-order perturbation analyses to monitor the electron flow and change in oxidation state on each atomic center along the reaction coordinate to rationalize the energetics and regioselectivity of this catalytic mechanism. We find that in GlvA, the redox catalytic mechanism of hydrolysis is driven by the gradual strengthening of the axial endo-anomeric component within the hexose ring along the reaction coordinate to facilitate the heterolytic dissociation of the axial C1-O bond. In addition, the combined influence of specific components of the generalized anomeric effect fully explains the regioselectivity observed in the catalytic activity of GlvA.
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Affiliation(s)
- Wenjuan Huang
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario N9B 3P4, Canada
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41
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Ortega-Castro J, Adrover M, Frau J, Salvà A, Donoso J, Muñoz F. DFT Studies on Schiff Base Formation of Vitamin B6 Analogues. Reaction between a Pyridoxamine-Analogue and Carbonyl Compounds. J Phys Chem A 2010; 114:4634-40. [DOI: 10.1021/jp909156m] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- J. Ortega-Castro
- Institut Universitari d’Investigació en Ciències de la Salut (IUNICS), Departament de Química, Universitat de les Illes Balears, Cra. Valldemossa km 7.5, E-07122 Palma de Mallorca, Spain
| | - M. Adrover
- Institut Universitari d’Investigació en Ciències de la Salut (IUNICS), Departament de Química, Universitat de les Illes Balears, Cra. Valldemossa km 7.5, E-07122 Palma de Mallorca, Spain
| | - J. Frau
- Institut Universitari d’Investigació en Ciències de la Salut (IUNICS), Departament de Química, Universitat de les Illes Balears, Cra. Valldemossa km 7.5, E-07122 Palma de Mallorca, Spain
| | - A. Salvà
- Institut Universitari d’Investigació en Ciències de la Salut (IUNICS), Departament de Química, Universitat de les Illes Balears, Cra. Valldemossa km 7.5, E-07122 Palma de Mallorca, Spain
| | - J. Donoso
- Institut Universitari d’Investigació en Ciències de la Salut (IUNICS), Departament de Química, Universitat de les Illes Balears, Cra. Valldemossa km 7.5, E-07122 Palma de Mallorca, Spain
| | - F. Muñoz
- Institut Universitari d’Investigació en Ciències de la Salut (IUNICS), Departament de Química, Universitat de les Illes Balears, Cra. Valldemossa km 7.5, E-07122 Palma de Mallorca, Spain
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Szu PH, Ruszczycky MW, Choi SH, Yan F, Liu HW. Characterization and mechanistic studies of DesII: a radical S-adenosyl-L-methionine enzyme involved in the biosynthesis of TDP-D-desosamine. J Am Chem Soc 2009; 131:14030-42. [PMID: 19746907 PMCID: PMC2780582 DOI: 10.1021/ja903354k] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
D-desosamine (1) is a 3-(N,N-dimethylamino)-3,4,6-trideoxyhexose found in a number of macrolide antibiotics including methymycin (2), neomethymycin (3), pikromycin (4), and narbomycin (5) produced by Streptomyces venezuelae . It plays an essential role in conferring biological activities to its parent aglycones. Previous genetic and biochemical studies of the biosynthesis of desosamine in S. venezuelae showed that the conversion of TDP-4-amino-4,6-dideoxy-D-glucose (8) to TDP-3-keto-4,6-dideoxy-D-glucose (9) is catalyzed by DesII, which is a member of the radical S-adenosyl-L-methionine (SAM) enzyme superfamily. Here, we report the purification and reconstitution of His(6)-tagged DesII, characterization of its [4Fe-4S] cluster using UV-vis and EPR spectroscopies, and the capability of flavodoxin, flavodoxin reductase, and NADPH to reduce the [4Fe-4S](2+) cluster. Also included are a steady-state kinetic analysis of DesII-catalyzed reaction and an investigation of the substrate flexibility of DesII. Studies of deuterium incorporation into SAM using TDP-[3-(2)H]-4-amino-4,6-dideoxy-D-glucose as the substrate provides strong evidence for direct hydrogen atom transfer to a 5'-deoxyadenosyl radical in the catalytic cycle. The fact that hydrogen atom abstraction occurs at C-3 also sheds light on the mechanism of this intriguing deamination reaction.
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Affiliation(s)
- Ping-Hui Szu
- Division of Medicinal Chemistry, College of Pharmacy, and Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712, USA
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Recent advances in the synthesis of 2-deoxy-glycosides. Carbohydr Res 2009; 344:1911-40. [DOI: 10.1016/j.carres.2009.07.013] [Citation(s) in RCA: 127] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2009] [Accepted: 07/29/2009] [Indexed: 11/23/2022]
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Richard JP, Amyes TL, Crugeiras J, Rios A. Pyridoxal 5'-phosphate: electrophilic catalyst extraordinaire. Curr Opin Chem Biol 2009; 13:475-83. [PMID: 19640775 DOI: 10.1016/j.cbpa.2009.06.023] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2009] [Accepted: 06/16/2009] [Indexed: 11/28/2022]
Abstract
Studies of nonenzymatic electrophilic catalysis of carbon deprotonation of glycine show that pyridoxal 5'-phosphate (PLP) strongly enhances the carbon acidity of alpha-amino acids, but that this is not the overriding mechanistic imperative for cofactor catalysis. Although the fully protonated PLP-glycine iminium ion adduct exhibits an extraordinary low alpha-imino carbon acidity (pK(a)=6), the more weakly acidic zwitterionic iminium ion adduct (pK(a)=17) is selected for use in enzymatic reactions. The similar alpha-imino carbon acidities of the iminium ion adducts of glycine with 5'-deoxypyridoxal and with phenylglyoxylate show that the cofactor pyridine nitrogen plays a relatively minor role in carbanion stabilization. The 5'-phosphodianion group of PLP likely plays an important role in catalysis by providing up to 12 kcal/mol of binding energy that may be utilized for transition state stabilization.
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Affiliation(s)
- John P Richard
- Department of Chemistry, University at Buffalo, State University of New York, Buffalo, NY 14260-3000, USA.
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Hou D, Lowary TL. 2,3-Anhydrosugars in glycoside bond synthesis. Application to 2,6-dideoxypyranosides. J Org Chem 2009; 74:2278-89. [PMID: 19249832 DOI: 10.1021/jo900131a] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We describe here the first use of 2,3-anhydrosugars as glycosylating agents for the preparation of 2-deoxypyranosides. In particular, the methodology was used to assemble 2,6-dideoxysugar glycosides. Glycosylation of a panel of alcohols with one of two 6-deoxy-2,3-anhydrosugar thioglycosides (8 and 9) in the presence of a Lewis acid afforded 2,6-dideoxy-2-thiotolyl glycoside products in generally excellent yields with an exclusively syn relationship between the aglycon and the C-3 hydroxyl group. Removal of the 2-thiotolyl group can be achieved upon reaction with tri-n-butyltin hydride and AIBN to give the corresponding 2,6-dideoxy pyranosides. Once developed, the method was applied to the synthesis of oligosaccharide moieties in the natural products apoptolidin and olivomycin A.
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Affiliation(s)
- Dianjie Hou
- 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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Abstract
Many biologically active bacterial natural products contain highly modified deoxysugar residues that are often critical for the activity of the parent compounds. Most of these deoxysugars are secondary metabolites that are biosynthesized in the form of nucleotide diphosphate (NDP) sugars prior to their transfer to natural product aglycones by glycosyltransferases. Over the past decade, many biosynthetic pathways that lead to the formation of these unusual sugars have been unraveled, and the mechanisms of many key enzymatic transformations involved in these pathways have been elucidated. However, obtaining workable quantities of NDP-deoxysugars for in vitro studies is often a difficult task. This limitation has hindered an in-depth investigation of the substrate specificity of deoxysugar biosynthetic enzymes, many of which are promiscuous with respect to their NDP-sugar substrates and are, thus, potentially useful catalysts for natural product glycoengineering. Presented in this review are procedures for the enzymatic synthesis and purification of a variety of NDP-deoxysugars, including some early intermediates in NDP-deoxysugar biosynthetic pathways, and highly modified NDP-deoxysugars that are late intermediates in their respective biosynthetic pathways. The procedures described herein could be used as general guidelines for the development of specific protocols for the synthesis of other NDP-deoxysugars.
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Chiu HT, Chen YL, Chen CY, Jin C, Lee MN, Lin YC. Molecular cloning, sequence analysis and functional characterization of the gene cluster for biosynthesis of K-252a and its analogs. MOLECULAR BIOSYSTEMS 2009; 5:1180-91. [DOI: 10.1039/b905293c] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Thibodeaux C, Melançon C, Liu HW. Biosynthese von Naturstoffzuckern und enzymatische Glycodiversifizierung. Angew Chem Int Ed Engl 2008. [DOI: 10.1002/ange.200801204] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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49
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Transient oxidation as a mechanistic strategy in enzymatic catalysis. Curr Opin Chem Biol 2008; 12:532-8. [DOI: 10.1016/j.cbpa.2008.06.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2008] [Accepted: 06/17/2008] [Indexed: 11/18/2022]
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Cook PD, Carney AE, Holden HM. Accommodation of GDP-linked sugars in the active site of GDP-perosamine synthase. Biochemistry 2008; 47:10685-93. [PMID: 18795799 DOI: 10.1021/bi801309q] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Perosamine (4-amino-4,6-dideoxy- d-mannose), or its N-acetylated form, is one of several dideoxy sugars found in the O-antigens of such infamous Gram-negative bacteria as Vibrio cholerae O1 and Escherichia coli O157:H7. It is added to the bacterial O-antigen via a nucleotide-linked version, namely GDP-perosamine. Three enzymes are required for the biosynthesis of GDP-perosamine starting from mannose 1-phosphate. The focus of this investigation is GDP-perosamine synthase from Caulobacter crescentus, which catalyzes the final step in GDP-perosamine synthesis, the conversion of GDP-4-keto-6-deoxymannose to GDP-perosamine. The enzyme is PLP-dependent and belongs to the aspartate aminotransferase superfamily. It contains the typically conserved active site lysine residue, which forms a Schiff base with the PLP cofactor. Two crystal structures were determined for this investigation: a site-directed mutant protein (K186A) complexed with GDP-perosamine and the wild-type enzyme complexed with an unnatural ligand, GDP-3-deoxyperosamine. These structures, determined to 1.6 and 1.7 A resolution, respectively, revealed the manner in which products, and presumably substrates, are accommodated within the active site pocket of GDP-perosamine synthase. Additional kinetic analyses using both the natural and unnatural substrates revealed that the K m for the unnatural substrate was unperturbed relative to that of the natural substrate, but the k cat was lowered by a factor of approximately 200. Taken together, these studies shed light on why GDP-perosamine synthase functions as an aminotransferase whereas another very similar PLP-dependent enzyme, GDP-4-keto-6-deoxy- d-mannose 3-dehydratase or ColD, catalyzes a dehydration reaction using the same substrate.
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Affiliation(s)
- Paul D Cook
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706, USA
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