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Ma J, Wang L, Qiao A, Li Z, Zhao F, Wu J. Synthesis of alkenylphosphine oxides via Tf 2O promoted addition-elimination of ketones and secondary phosphine oxides. Org Biomol Chem 2024; 22:3592-3596. [PMID: 38624160 DOI: 10.1039/d4ob00318g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/17/2024]
Abstract
Herein, we describe an efficient method for the synthesis of alkenylphosphine oxides via a Tf2O promoted addition-elimination process. Various diarylphosphine oxides and alkylarylphosphine oxides react with ketones smoothly and produce alkenylphosphine oxides in moderate to excellent yields with abundant functional group compatibility. In addition, several transformations and applications of the product also demonstrate the potential value of the methodology.
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Affiliation(s)
- Jiangkai Ma
- Green Catalysis Center, and College of Chemistry, Zhengzhou University, Zhengzhou 450001, P. R. China.
| | - Lianjie Wang
- High & New Technology Research Center, Henan Academy of Sciences, Zhengzhou 450002, P. R. China
| | - Anjiang Qiao
- Green Catalysis Center, and College of Chemistry, Zhengzhou University, Zhengzhou 450001, P. R. China.
| | - Zhongxian Li
- High & New Technology Research Center, Henan Academy of Sciences, Zhengzhou 450002, P. R. China
| | - Fengqian Zhao
- Green Catalysis Center, and College of Chemistry, Zhengzhou University, Zhengzhou 450001, P. R. China.
| | - Junliang Wu
- Green Catalysis Center, and College of Chemistry, Zhengzhou University, Zhengzhou 450001, P. R. China.
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2
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Heimhalt M, Mukherjee P, Grainger RA, Szabla R, Brown C, Turner R, Junop MS, Berti PJ. An Inhibitor-in-Pieces Approach to DAHP Synthase Inhibition: Potent Enzyme and Bacterial Growth Inhibition. ACS Infect Dis 2021; 7:3292-3302. [PMID: 34761906 DOI: 10.1021/acsinfecdis.1c00462] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
3-Deoxy-d-arabinoheptulosonate-7-phosphate (DAHP) synthase catalyzes the first step in the shikimate biosynthetic pathway and is an antimicrobial target. We used an inhibitor-in-pieces approach, based on the previously reported inhibitor DAHP oxime, to screen inhibitor fragments in the presence and absence of glycerol 3-phosphate to occupy the distal end of the active site. This led to DAHP hydrazone, the most potent inhibitor to date, Ki = 10 ± 1 nM. Three trifluoropyruvate (TFP)-based inhibitor fragments were efficient inhibitors with ligand efficiencies of up to 0.7 kcal mol-1/atom compared with 0.2 kcal mol-1/atom for a typical good inhibitor. The crystal structures showed the TFP-based inhibitors binding upside down in the active site relative to DAHP oxime, providing new avenues for inhibitor development. The ethyl esters of TFP oxime and TFP semicarbazone prevented E. coli growth in culture with IC50 = 0.21 ± 0.01 and 0.77 ± 0.08 mg mL-1, respectively. Overexpressing DAHP synthase relieved growth inhibition, demonstrating that DAHP synthase was the target. Growth inhibition occurred in media containing aromatic amino acids, suggesting that growth inhibition was due to depletion of some other product(s) of the shikimate pathway, possibly folate.
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Affiliation(s)
| | | | - Ryan A. Grainger
- Department of Biochemistry, Molecular Biology Lab, Western University, London, Ontario N6A 5C1, Canada
| | - Robert Szabla
- Department of Biochemistry, Molecular Biology Lab, Western University, London, Ontario N6A 5C1, Canada
| | - Christopher Brown
- Department of Biochemistry, Molecular Biology Lab, Western University, London, Ontario N6A 5C1, Canada
| | | | - Murray S. Junop
- Department of Biochemistry, Molecular Biology Lab, Western University, London, Ontario N6A 5C1, Canada
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3
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Popović V, Morrison E, Rosanally AZ, Balachandran N, Senson AW, Szabla R, Junop MS, Berti PJ. NeuNAc Oxime: A Slow-Binding and Effectively Irreversible Inhibitor of the Sialic Acid Synthase NeuB. Biochemistry 2019; 58:4236-4245. [PMID: 31549502 DOI: 10.1021/acs.biochem.9b00654] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
NeuB is a bacterial sialic acid synthase used by neuroinvasive bacteria to synthesize N-acetylneuraminate (NeuNAc), helping them to evade the host immune system. NeuNAc oxime is a potent slow-binding NeuB inhibitor. It dissociated too slowly to be detected experimentally, with initial estimates of its residence time in the active site being >47 days. This is longer than the lifetime of a typical bacterial cell, meaning that inhibition is effectively irreversible. Inhibition data fitted well to a model that included a pre-equilibration step with a Ki of 36 μM, followed by effectively irreversible conversion to an E*·I complex, with a k2 of 5.6 × 10-5 s-1. Thus, the inhibitor can subvert ligand release and achieve extraordinary residence times in spite of a relatively modest initial dissociation constant. The crystal structure showed the oxime functional group occupying the phosphate-binding site normally occupied by the substrate PEP and the tetrahedral intermediate. There was an ≈10% residual rate at high inhibitor concentrations regardless of how long NeuB and NeuNAc oxime were preincubated together. However, complete inhibition was achieved by incubating NeuNAc oxime with the actively catalyzing enzyme. This requirement for the enzyme to be actively turning over for the inhibitor to bind to the second subunit demonstrated an important role for intersubunit communication in the inhibitory mechanism.
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Affiliation(s)
| | | | | | | | | | - Robert Szabla
- Department of Biochemistry, Molecular Biology Lab , Western University , London , ON N6A 5C1 , Canada
| | - Murray S Junop
- Department of Biochemistry, Molecular Biology Lab , Western University , London , ON N6A 5C1 , Canada
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4
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Heimhalt M, Jiang S, Berti PJ. Eliminating Competition: Characterizing and Eliminating Competitive Binding at Separate Sites between DAHP Synthase’s Essential Metal Ion and the Inhibitor DAHP Oxime. Biochemistry 2018; 57:6679-6687. [DOI: 10.1021/acs.biochem.8b00837] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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5
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Gama SR, Balachandran N, Berti PJ. Campylobacter jejuni KDO8P Synthase, Its Inhibition by KDO8P Oxime, and Control of the Residence Time of Slow-Binding Inhibition. Biochemistry 2018; 57:5327-5338. [DOI: 10.1021/acs.biochem.8b00748] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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6
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Cytlak T, Skibińska M, Kaczmarek P, Kaźmierczak M, Rapp M, Kubicki M, Koroniak H. Functionalization of α-hydroxyphosphonates as a convenient route to N-tosyl-α-aminophosphonates. RSC Adv 2018; 8:11957-11974. [PMID: 35539392 PMCID: PMC9079259 DOI: 10.1039/c8ra01656a] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2018] [Accepted: 03/14/2018] [Indexed: 11/21/2022] Open
Abstract
Direct conversion of the α-hydroxyl group by para-toluenesulfonamide to yield α-(N-tosyl)aminophosphonates is reported. α-Aminophosphonates 23a,b-37a,b were obtained from the corresponding α-hydroxyphosphonates 6a,b-21a,b in the presence of K2CO3, via the retro-Abramov reaction of the appropriate aldehydes, 1-5. The subsequent formation of imines with simultaneous addition of diethyl phosphite provided access to the α-sulfonamide phosphonates 23a,b-37a,b with better diastereoselectivity than in the case of the Pudovik reaction. The mechanism for this transformation is proposed herein. When Cbz N-protected aziridine 9a,b and phenylalanine analogue 12a,b were exploited, intramolecular substitution was observed, leading to the corresponding epoxide 38 as the sole product, or oxazolidin-2-one 39 as a minor product. Analogous substitution was not observed in the case of proline 18a,b and serine 21a,b derivatives.
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Affiliation(s)
- Tomasz Cytlak
- Faculty of Chemistry, Adam Mickiewicz University in Poznań Umultowska 89b 61-614 Poznań Poland.,Centre for Advanced Technologies, Adam Mickiewicz University in Poznań Umultowska 89c 61-614 Poznań Poland
| | - Monika Skibińska
- Faculty of Chemistry, Adam Mickiewicz University in Poznań Umultowska 89b 61-614 Poznań Poland
| | - Patrycja Kaczmarek
- Faculty of Chemistry, Adam Mickiewicz University in Poznań Umultowska 89b 61-614 Poznań Poland
| | - Marcin Kaźmierczak
- Faculty of Chemistry, Adam Mickiewicz University in Poznań Umultowska 89b 61-614 Poznań Poland.,Centre for Advanced Technologies, Adam Mickiewicz University in Poznań Umultowska 89c 61-614 Poznań Poland
| | - Magdalena Rapp
- Faculty of Chemistry, Adam Mickiewicz University in Poznań Umultowska 89b 61-614 Poznań Poland
| | - Maciej Kubicki
- Faculty of Chemistry, Adam Mickiewicz University in Poznań Umultowska 89b 61-614 Poznań Poland
| | - Henryk Koroniak
- Faculty of Chemistry, Adam Mickiewicz University in Poznań Umultowska 89b 61-614 Poznań Poland
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Balachandran N, To F, Berti PJ. Linear Free Energy Relationship Analysis of Transition State Mimicry by 3-Deoxy-d-arabino-heptulosonate-7-phosphate (DAHP) Oxime, a DAHP Synthase Inhibitor and Phosphate Mimic. Biochemistry 2017; 56:592-601. [PMID: 28045507 DOI: 10.1021/acs.biochem.6b01211] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Naresh Balachandran
- Department of Chemistry & Chemical Biology and ‡Department of Biochemistry & Biomedical Sciences, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4M1, Canada
| | - Frederick To
- Department of Chemistry & Chemical Biology and ‡Department of Biochemistry & Biomedical Sciences, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4M1, Canada
| | - Paul J. Berti
- Department of Chemistry & Chemical Biology and ‡Department of Biochemistry & Biomedical Sciences, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4M1, Canada
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8
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Balachandran N, Heimhalt M, Liuni P, To F, Wilson DJ, Junop MS, Berti PJ. Potent Inhibition of 3-Deoxy-d-arabinoheptulosonate-7-phosphate (DAHP) Synthase by DAHP Oxime, a Phosphate Group Mimic. Biochemistry 2016; 55:6617-6629. [DOI: 10.1021/acs.biochem.6b00930] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | | | - Peter Liuni
- Department
of Chemistry, York University, Toronto, Ontario M3J 1P3, Canada
| | | | - Derek J. Wilson
- Department
of Chemistry, York University, Toronto, Ontario M3J 1P3, Canada
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Structural analysis of substrate-mimicking inhibitors in complex with Neisseria meningitidis 3-deoxy-d-arabino-heptulosonate 7-phosphate synthase – The importance of accommodating the active site water. Bioorg Chem 2014; 57:242-250. [DOI: 10.1016/j.bioorg.2014.08.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2014] [Revised: 08/15/2014] [Accepted: 08/17/2014] [Indexed: 11/19/2022]
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Joseph DDA, Jiao W, Parker EJ. Arg314 is essential for catalysis by N-acetyl neuraminic acid synthase from Neisseria meningitidis. Biochemistry 2013; 52:2609-19. [PMID: 23534460 DOI: 10.1021/bi400062c] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The sialic acid N-acetylneuraminic acid (NANA) has a key role in the pathogenesis of a select number of neuroinvasive bacteria such as Neisseria meningitidis. These pathogens coat themselves with polysialic acids, mimicking the exterior surface of mammalian cells and consequentially concealing the bacteria from the host's immune system. NANA is synthesized in bacteria by the homodimeric enzyme NANA synthase (NANAS), which catalyzes a condensation reaction between phosphoenolpyruvate (PEP) and N-acetylmannosamine (ManNAc). NANAS is closely related to the α-keto acid synthases 3-deoxy-d-arabino-heptulosonate 7-phosphate synthase and 3-deoxy-d-manno-octulosonate 8-phosphate synthase. NANAS differs from these enzymes in that it contains an antifreeze protein like (AFPL) domain, which extends from the C-terminal of the (β/α)8 barrel containing the active site and contributes a highly conserved arginine (Arg314) into the active site of the opposing monomer chain. We have investigated the role of Arg314 in NmeNANAS through mutagenesis and a combination of kinetic and structural analyses. Using isothermal titration calorimetry and molecular modeling, we have shown that Arg314 is required for the catalytic function of NANAS and that the delocalized positively charged guanidinium functionality of this residue provides steering of the sugar substrate ManNAc for suitable placement in the active site and thus reaction with PEP.
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Affiliation(s)
- Dmitri D A Joseph
- Biomolecular Interaction Centre and Department of Chemistry, University of Canterbury , Christchurch, New Zealand
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11
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Reichau S, Jiao W, Walker SR, Hutton RD, Baker EN, Parker EJ. Potent inhibitors of a shikimate pathway enzyme from Mycobacterium tuberculosis: combining mechanism- and modeling-based design. J Biol Chem 2011; 286:16197-207. [PMID: 21454647 PMCID: PMC3093739 DOI: 10.1074/jbc.m110.211649] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2010] [Revised: 02/07/2011] [Indexed: 11/06/2022] Open
Abstract
Tuberculosis remains a serious global health threat, with the emergence of multidrug-resistant strains highlighting the urgent need for novel antituberculosis drugs. The enzyme 3-deoxy-D-arabino-heptulosonate 7-phosphate synthase (DAH7PS) catalyzes the first step of the shikimate pathway for the biosynthesis of aromatic compounds. This pathway has been shown to be essential in Mycobacterium tuberculosis, the pathogen responsible for tuberculosis. DAH7PS catalyzes a condensation reaction between P-enolpyruvate and erythrose 4-phosphate to give 3-deoxy-D-arabino-heptulosonate 7-phosphate. The enzyme reaction mechanism is proposed to include a tetrahedral intermediate, which is formed by attack of an active site water on the central carbon of P-enolpyruvate during the course of the reaction. Molecular modeling of this intermediate into the active site reported in this study shows a configurational preference consistent with water attack from the re face of P-enolpyruvate. Based on this model, we designed and synthesized an inhibitor of DAH7PS that mimics this reaction intermediate. Both enantiomers of this intermediate mimic were potent inhibitors of M. tuberculosis DAH7PS, with inhibitory constants in the nanomolar range. The crystal structure of the DAH7PS-inhibitor complex was solved to 2.35 Å. Both the position of the inhibitor and the conformational changes of active site residues observed in this structure correspond closely to the predictions from the intermediate modeling. This structure also identifies a water molecule that is located in the appropriate position to attack the re face of P-enolpyruvate during the course of the reaction, allowing the catalytic mechanism for this enzyme to be clearly defined.
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Affiliation(s)
- Sebastian Reichau
- From the Biomolecular Interaction Centre and Department of Chemistry, University of Canterbury, Christchurch 8140 and
| | - Wanting Jiao
- From the Biomolecular Interaction Centre and Department of Chemistry, University of Canterbury, Christchurch 8140 and
| | - Scott R. Walker
- From the Biomolecular Interaction Centre and Department of Chemistry, University of Canterbury, Christchurch 8140 and
| | - Richard D. Hutton
- From the Biomolecular Interaction Centre and Department of Chemistry, University of Canterbury, Christchurch 8140 and
| | - Edward N. Baker
- the Maurice Wilkins Centre for Molecular Biodiscovery and School of Biological Sciences, University of Auckland, Auckland 1010, New Zealand
| | - Emily J. Parker
- From the Biomolecular Interaction Centre and Department of Chemistry, University of Canterbury, Christchurch 8140 and
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Houghton SR, Melton J, Fortunak J, Brown Ripin DH, Boddy CN. Rapid, mild method for phosphonate diester hydrolysis: development of a one-pot synthesis of tenofovir disoproxil fumarate from tenofovir diethyl ester. Tetrahedron 2010. [DOI: 10.1016/j.tet.2010.08.037] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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13
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Liu F, Lee HJ, Strynadka NCJ, Tanner ME. Inhibition of Neisseria meningitidis sialic acid synthase by a tetrahedral intermediate analogue. Biochemistry 2009; 48:9194-201. [PMID: 19719325 DOI: 10.1021/bi9012758] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The Neisseria meningitidis sialic acid synthase (NeuB) catalyzes the metal-dependent condensation of N-acetylmannosamine (ManNAc) and phosphoenolpyruvate (PEP) to generate N-acetylneuraminic acid (NeuAc or sialic acid). N. meningitidis is a causative agent of meningitis and produces a capsular polysaccharide comprised of polysialic acid. This allows it to evade the immune system of the host by an act of molecular mimicry. This work describes the synthesis and characterization of the first potent inhibitor of sialic acid synthase. The inhibitor is a stable deoxy analogue of the tetrahedral intermediate presumed to form in the NeuB reaction and was synthesized as a mixture of stereoisomers at the key tetrahedral center. Inhibition studies demonstrate that one stereoisomer binds more tightly than the other and that the more potent isomer binds with micromolar affinity. An X-ray crystallographic analysis of the NeuB.inhibitor.Mn(2+) complex solved to a resolution of 1.75 A shows that the more tightly bound stereoisomer bears a (2R)-configuration. This suggests that the tetrahedral intermediate formed in the NeuB reaction also bears a (2R)-configuration. This analysis is consistent with a mechanism whereby the active site metal plays at least two roles during catalysis. First, it serves as an electrostatic catalyst and activates the aldehyde of ManNAc for attack by the alkene of PEP. Second, it serves as a source of nucleophilic water and delivers it to the si face of the oxocarbenium intermediate to generate a tetrahedral intermediate with a (2R)-configuration.
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Affiliation(s)
- Feng Liu
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z1
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Walker SR, Cumming H, Parker EJ. Substrate and reaction intermediate mimics as inhibitors of 3-deoxy-d-arabino-heptulosonate 7-phosphate synthase. Org Biomol Chem 2009. [DOI: 10.1039/b909241b] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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