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Ambade SS, Gupta VK, Bhole RP, Khedekar PB, Chikhale RV. A Review on Five and Six-Membered Heterocyclic Compounds Targeting the Penicillin-Binding Protein 2 (PBP2A) of Methicillin-Resistant Staphylococcus aureus (MRSA). Molecules 2023; 28:7008. [PMID: 37894491 PMCID: PMC10609489 DOI: 10.3390/molecules28207008] [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: 09/08/2023] [Revised: 10/05/2023] [Accepted: 10/05/2023] [Indexed: 10/29/2023] Open
Abstract
Staphylococcus aureus is a common human pathogen. Methicillin-resistant Staphylococcus aureus (MRSA) infections pose significant and challenging therapeutic difficulties. MRSA often acquires the non-native gene PBP2a, which results in reduced susceptibility to β-lactam antibiotics, thus conferring resistance. PBP2a has a lower affinity for methicillin, allowing bacteria to maintain peptidoglycan biosynthesis, a core component of the bacterial cell wall. Consequently, even in the presence of methicillin or other antibiotics, bacteria can develop resistance. Due to genes responsible for resistance, S. aureus becomes MRSA. The fundamental premise of this resistance mechanism is well-understood. Given the therapeutic concerns posed by resistant microorganisms, there is a legitimate demand for novel antibiotics. This review primarily focuses on PBP2a scaffolds and the various screening approaches used to identify PBP2a inhibitors. The following classes of compounds and their biological activities are discussed: Penicillin, Cephalosporins, Pyrazole-Benzimidazole-based derivatives, Oxadiazole-containing derivatives, non-β-lactam allosteric inhibitors, 4-(3H)-Quinazolinones, Pyrrolylated chalcone, Bis-2-Oxoazetidinyl macrocycles (β-lactam antibiotics with 1,3-Bridges), Macrocycle-embedded β-lactams as novel inhibitors, Pyridine-Coupled Pyrimidinones, novel Naphthalimide corbelled aminothiazoximes, non-covalent inhibitors, Investigational-β-lactam antibiotics, Carbapenem, novel Benzoxazole derivatives, Pyrazolylpyridine analogues, and other miscellaneous classes of scaffolds for PBP2a. Additionally, we discuss the penicillin-binding protein, a crucial target in the MRSA cell wall. Various aspects of PBP2a, bacterial cell walls, peptidoglycans, different crystal structures of PBP2a, synthetic routes for PBP2a inhibitors, and future perspectives on MRSA inhibitors are also explored.
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Affiliation(s)
- Shraddha S. Ambade
- Department of Pharmaceutical Sciences, Rashtrasant Tukadoji Maharaj Nagpur University, Nagpur 440033, MH, India (P.B.K.)
| | - Vivek Kumar Gupta
- Department of Biochemistry, National JALMA Institute for Leprosy & Other Mycobacterial Diseases (ICMR), Agra 282004, UP, India
| | - Ritesh P. Bhole
- Dr. D. Y. Patil Institute of Pharmaceutical Sciences and Research, Pimpri, Pune 411018, MH, India
- Dr. D. Y. Patil Dental College and Hospital, Dr. D. Y. Patil Vidyapeeth, Pimpri, Pune 411018, MH, India
| | - Pramod B. Khedekar
- Department of Pharmaceutical Sciences, Rashtrasant Tukadoji Maharaj Nagpur University, Nagpur 440033, MH, India (P.B.K.)
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2
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Mohamed A, Al-Awadhi FH, Al-Awadi NA. Variable-Sized bis(4-spiro-fused-β-lactam)-Based Unsaturated Macrocycles: Synthesis and Characterization. ACS OMEGA 2022; 7:36795-36803. [PMID: 36278047 PMCID: PMC9583306 DOI: 10.1021/acsomega.2c05212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/14/2022] [Accepted: 09/19/2022] [Indexed: 06/16/2023]
Abstract
The synthesis with structural identifications including NMR and HRMS spectral data along with single-crystal X-ray diffraction analysis (for 20b, 23b, 25b-27b) of a family of 14 new syn/anti bis-4-spiro-β-lactam-based unsaturated macrocycles (19a,b-27a,b), obtained by multistep synthesis including (i) diimine formation, (ii) Staudinger [2 + 2] ketene-imine cycloaddition, and (iii) ring-closing metathesis (RCM), is reported.
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Affiliation(s)
- Asaad
S. Mohamed
- Department
of Chemistry, Faculty of Science, Kuwait
University, P.O. Box 5969, Safat 13060, Kuwait
| | - Fatma H. Al-Awadhi
- Department
of Pharmaceutical Chemistry, Faculty of Pharmacy, Kuwait University, Safat 13060, Kuwait
| | - Nouria A. Al-Awadi
- Department
of Chemistry, Faculty of Science, Kuwait
University, P.O. Box 5969, Safat 13060, Kuwait
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3
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Habib OM, Mohamed AS, Ibrahim YA, Al-Awadi NA. Sequential Diimination, Staudinger [2 + 2] Ketene-Imine Cycloaddition, and Ring-Closing Metathesis (RCM) Reactions: In Route to Bis(4-spiro-fused-β-lactams)-Based Macrocycles. J Org Chem 2021; 86:14777-14785. [PMID: 34609859 DOI: 10.1021/acs.joc.1c01576] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Based on sequential organic transformations, that is, diimine formation, Staudinger [2 + 2] ketene-imine cycloaddition, and ring-closing metathesis (RCM) reactions, the synthesis with full structural identification including NMR and HRMS spectral data along with single X-ray diffraction analysis (for anti 7b, anti 8b, syn 9a, and anti 9b) of the first syn/anti bis-4-spiro-β-lactams-based azacrown ethers (7a,b-9a,b) is reported.
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Affiliation(s)
- Osama M Habib
- Biochemistry Department, Faculty of Medicine, Kuwait University, P.O. Box 5969, Safat 13060, Kuwait
| | - Asaad S Mohamed
- Department of Chemistry, Faculty of Science, Kuwait University, P.O. Box 5969, Safat 13060, Kuwait
| | - Yehia A Ibrahim
- Department of Chemistry, Faculty of Science, Kuwait University, P.O. Box 5969, Safat 13060, Kuwait
| | - Nouria A Al-Awadi
- Department of Chemistry, Faculty of Science, Kuwait University, P.O. Box 5969, Safat 13060, Kuwait
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4
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Shalaby MAW, Dokla EME, Serya RAT, Abouzid KAM. Penicillin binding protein 2a: An overview and a medicinal chemistry perspective. Eur J Med Chem 2020; 199:112312. [PMID: 32442851 DOI: 10.1016/j.ejmech.2020.112312] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 03/28/2020] [Accepted: 04/05/2020] [Indexed: 12/17/2022]
Abstract
Antimicrobial resistance is an imminent threat worldwide. Methicillin-resistant Staphylococcus aureus (MRSA) is one of the "superbug" family, manifesting resistance through the production of a penicillin binding protein, PBP2a, an enzyme that provides its transpeptidase activity to allow cell wall biosynthesis. PBP2a's low affinity to most β-lactams, confers resistance to MRSA against numerous members of this class of antibiotics. An Achilles' heel of MRSA, PBP2a represents a substantial target to design novel antibiotics to tackle MRSA threat via inhibition of the bacterial cell wall biosynthesis. In this review we bring into focus the PBP2a enzyme and examine the various aspects related to its role in conferring resistance to MRSA strains. Moreover, we discuss several antibiotics and antimicrobial agents designed to target PBP2a and their therapeutic potential to meet such a grave threat. In conclusion, we consider future perspectives for targeting MRSA infections.
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Affiliation(s)
- Menna-Allah W Shalaby
- Pharmaceutical Chemistry Department, Faculty of Pharmacy, Ain Shams University, Abbassia, 11566, Cairo, Egypt
| | - Eman M E Dokla
- Pharmaceutical Chemistry Department, Faculty of Pharmacy, Ain Shams University, Abbassia, 11566, Cairo, Egypt.
| | - Rabah A T Serya
- Pharmaceutical Chemistry Department, Faculty of Pharmacy, Ain Shams University, Abbassia, 11566, Cairo, Egypt
| | - Khaled A M Abouzid
- Pharmaceutical Chemistry Department, Faculty of Pharmacy, Ain Shams University, Abbassia, 11566, Cairo, Egypt; Department of Organic and Medicinal Chemistry, Faculty of Pharmacy, University of Sadat City, Sadat City, Egypt.
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5
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Allen SE, Dokholyan NV, Bowers AA. Dynamic Docking of Conformationally Constrained Macrocycles: Methods and Applications. ACS Chem Biol 2016; 11:10-24. [PMID: 26575401 DOI: 10.1021/acschembio.5b00663] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Many natural products consist of large and flexible macrocycles that engage their targets via multiple contact points. This combination of contained flexibility and large contact area often allows natural products to bind at target surfaces rather than deep pockets, making them attractive scaffolds for inhibiting protein-protein interactions and other challenging therapeutic targets. The increasing ability to manipulate such compounds either biosynthetically or via semisynthetic modification means that these compounds can now be considered as starting points for medchem campaigns rather than solely as ends. Modern medchem benefits substantially from rational improvements made on the basis of molecular docking. As such, docking methods have been enhanced in recent years to deal with the complicated binding modalities and flexible scaffolds of macrocyclic natural products and natural product-like structures. Here, we comprehensively review methods for treating and docking these large macrocyclic scaffolds and discuss some of the resulting advances in medicinal chemistry.
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Affiliation(s)
- Scott E. Allen
- Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, and ‡Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Nikolay V. Dokholyan
- Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, and ‡Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Albert A. Bowers
- Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, and ‡Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
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Bessa LJ, Palmeira A, Gomes AS, Vasconcelos V, Sousa E, Pinto M, Martins da Costa P. Synergistic Effects Between Thioxanthones and Oxacillin Against Methicillin-Resistant Staphylococcus aureus. Microb Drug Resist 2015; 21:404-15. [PMID: 25789724 DOI: 10.1089/mdr.2014.0162] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The extensive use of antimicrobials is leaving medicine with few effective therapeutic options to treat many infections due to the fact that many organisms developed resistance to commonly used drugs. It is therefore pertinent to search not only for new antimicrobials but also for compounds able to restore or potentiate the activity of existing antibiotics. We have screened a library consisting of 40 (thio)xanthone derivatives for antibacterial activity and possible synergistic effects when used in combination with antibiotics. Nine out of the 40 compounds exhibited antibacterial activity against Gram-positive bacteria. Two xanthone derivatives, 1-formyl-4-hydroxy-3-methoxy (7), 2-formyl-3-hydroxy-4-methoxyxanthone (8) and the thioxanthone derivative 1-((2-(diethylamino)ethyl)amino)-4-propoxythioxanthone (10) and its hydrochloride form 13, showed activity against a methicillin-resistant Staphylococcus aureus (MRSA) isolate with minimum inhibitory concentration (MIC) values lower than 256 μg/ml. Thioxanthone 10 demonstrated antibacterial activity and also synergy when combined with ampicillin and oxacillin against MRSA. Additionally, thioxanthone 1-(piperidin-1-yl)-4-propoxythioxanthone (9), despite not having antibacterial activity presented remarkable synergy with oxacillin against MRSA; the MIC of tioxanthone 9 and oxacillin when both were in combination were 128 and 8 μg/ml, respectively. Thioxanthones 9 and 10 were also found to be synergistic when both were combined. Subsequently, docking simulations between thioxanthones 9 and 10 and the allosteric domain of penicillin-binding protein 2A (PBP2A) were undertaken in AutoDock Vina. Both compounds had the ability to bind with an allosteric domain of PBP2A, which may explain their synergy with oxacillin. These two thioxanthone derivatives with different profiles may be promising tools for restoring the activity of oxacillin against MRSA.
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Affiliation(s)
- Lucinda J Bessa
- 1 Laboratório de Microbiologia e Tecnologia Alimentar, Departamento de Produção Aquática, Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto , Porto, Portugal .,2 Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR), Universidade do Porto , Porto, Portugal
| | - Andreia Palmeira
- 3 Laboratório de Química Orgânica e Farmacêutica, Departamento de Ciências Químicas, Faculdade de Farmácia, Centro de Química Medicinal da Universidade do Porto (CEQUIMED-UP), Universidade do Porto , Porto, Portugal
| | - Ana S Gomes
- 3 Laboratório de Química Orgânica e Farmacêutica, Departamento de Ciências Químicas, Faculdade de Farmácia, Centro de Química Medicinal da Universidade do Porto (CEQUIMED-UP), Universidade do Porto , Porto, Portugal
| | - Vitor Vasconcelos
- 2 Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR), Universidade do Porto , Porto, Portugal .,4 Departamento de Biologia, Faculdade de Ciências, Universidade do Porto , Porto, Portugal
| | - Emília Sousa
- 2 Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR), Universidade do Porto , Porto, Portugal .,3 Laboratório de Química Orgânica e Farmacêutica, Departamento de Ciências Químicas, Faculdade de Farmácia, Centro de Química Medicinal da Universidade do Porto (CEQUIMED-UP), Universidade do Porto , Porto, Portugal
| | - Madalena Pinto
- 2 Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR), Universidade do Porto , Porto, Portugal .,3 Laboratório de Química Orgânica e Farmacêutica, Departamento de Ciências Químicas, Faculdade de Farmácia, Centro de Química Medicinal da Universidade do Porto (CEQUIMED-UP), Universidade do Porto , Porto, Portugal
| | - Paulo Martins da Costa
- 1 Laboratório de Microbiologia e Tecnologia Alimentar, Departamento de Produção Aquática, Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto , Porto, Portugal .,2 Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR), Universidade do Porto , Porto, Portugal
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7
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Herndon JW. The chemistry of the carbon-transition metal double and triple bond: Annual survey covering the year 2012. Coord Chem Rev 2014. [DOI: 10.1016/j.ccr.2014.02.026] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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8
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Dave K, Palzkill T, Pratt RF. Neutral β-Lactams Inactivate High Molecular Mass Penicillin-Binding Proteins of Class B1, Including PBP2a of MRSA. ACS Med Chem Lett 2014; 5:154-7. [PMID: 24900789 DOI: 10.1021/ml400408c] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2013] [Accepted: 12/06/2013] [Indexed: 11/28/2022] Open
Abstract
The targets of β-lactam antibiotics are bacterial DD-peptidases (penicillin-binding proteins). β-Lactam SAR studies over many years have demonstrated the importance of a specifically placed negative charge, usually carboxylate, on these molecules. We show here that neutral analogues of classical β-lactam antibiotics are of comparable activity to the originals against β-lactam-resistant high molecular mass DD-peptidases of the B1 class, a group that includes PBP2a of methicillin-resistant Staphylococcus aureus. These neutral β-lactams may direct new development of antibiotics against certain penicillin-resistant bacteria. These molecules do have antibiotic activity against Gram-positive bacteria.
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Affiliation(s)
- Kinjal Dave
- Department
of Chemistry, Wesleyan University, Middletown, Connecticut 06459, United States
| | - Timothy Palzkill
- Departments of Pharmacology, and Biochemistry & Molecular Biology, Baylor College of Medicine, Houston, Texas 77030, United States
| | - R. F. Pratt
- Department
of Chemistry, Wesleyan University, Middletown, Connecticut 06459, United States
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9
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Otero LH, Rojas-Altuve A, Llarrull LI, Carrasco-López C, Kumarasiri M, Lastochkin E, Fishovitz J, Dawley M, Hesek D, Lee M, Johnson JW, Fisher JF, Chang M, Mobashery S, Hermoso JA. How allosteric control of Staphylococcus aureus penicillin binding protein 2a enables methicillin resistance and physiological function. Proc Natl Acad Sci U S A 2013; 110:16808-13. [PMID: 24085846 PMCID: PMC3800995 DOI: 10.1073/pnas.1300118110] [Citation(s) in RCA: 185] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The expression of penicillin binding protein 2a (PBP2a) is the basis for the broad clinical resistance to the β-lactam antibiotics by methicillin-resistant Staphylococcus aureus (MRSA). The high-molecular mass penicillin binding proteins of bacteria catalyze in separate domains the transglycosylase and transpeptidase activities required for the biosynthesis of the peptidoglycan polymer that comprises the bacterial cell wall. In bacteria susceptible to β-lactam antibiotics, the transpeptidase activity of their penicillin binding proteins (PBPs) is lost as a result of irreversible acylation of an active site serine by the β-lactam antibiotics. In contrast, the PBP2a of MRSA is resistant to β-lactam acylation and successfully catalyzes the DD-transpeptidation reaction necessary to complete the cell wall. The inability to contain MRSA infection with β-lactam antibiotics is a continuing public health concern. We report herein the identification of an allosteric binding domain--a remarkable 60 Å distant from the DD-transpeptidase active site--discovered by crystallographic analysis of a soluble construct of PBP2a. When this allosteric site is occupied, a multiresidue conformational change culminates in the opening of the active site to permit substrate entry. This same crystallographic analysis also reveals the identity of three allosteric ligands: muramic acid (a saccharide component of the peptidoglycan), the cell wall peptidoglycan, and ceftaroline, a recently approved anti-MRSA β-lactam antibiotic. The ability of an anti-MRSA β-lactam antibiotic to stimulate allosteric opening of the active site, thus predisposing PBP2a to inactivation by a second β-lactam molecule, opens an unprecedented realm for β-lactam antibiotic structure-based design.
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Affiliation(s)
- Lisandro H. Otero
- Departamento de Cristalografía y Biología Estructural, Instituto de Química-Física “Rocasolano,” Consejo Superior de Investigaciones Cientificas, 28006 Madrid, Spain; and
| | - Alzoray Rojas-Altuve
- Departamento de Cristalografía y Biología Estructural, Instituto de Química-Física “Rocasolano,” Consejo Superior de Investigaciones Cientificas, 28006 Madrid, Spain; and
| | - Leticia I. Llarrull
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556
| | - Cesar Carrasco-López
- Departamento de Cristalografía y Biología Estructural, Instituto de Química-Física “Rocasolano,” Consejo Superior de Investigaciones Cientificas, 28006 Madrid, Spain; and
| | - Malika Kumarasiri
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556
| | - Elena Lastochkin
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556
| | - Jennifer Fishovitz
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556
| | - Matthew Dawley
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556
| | - Dusan Hesek
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556
| | - Mijoon Lee
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556
| | - Jarrod W. Johnson
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556
| | - Jed F. Fisher
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556
| | - Mayland Chang
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556
| | - Shahriar Mobashery
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556
| | - Juan A. Hermoso
- Departamento de Cristalografía y Biología Estructural, Instituto de Química-Física “Rocasolano,” Consejo Superior de Investigaciones Cientificas, 28006 Madrid, Spain; and
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10
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2-Nitrobenzyl Esters of Penam and Cephem Derivatives as Inhibitors of Penicillin-Binding Proteins. ASIAN J ORG CHEM 2013. [DOI: 10.1002/ajoc.201300108] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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11
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Dive G, Bouillon C, Sliwa A, Valet B, Verlaine O, Sauvage E, Marchand-Brynaert J. Macrocycle-embedded β-lactams as novel inhibitors of the Penicillin Binding Protein PBP2a from MRSA. Eur J Med Chem 2013; 64:365-76. [PMID: 23648973 DOI: 10.1016/j.ejmech.2013.03.052] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Revised: 03/20/2013] [Accepted: 03/24/2013] [Indexed: 10/27/2022]
Abstract
Assuming that bicyclic β-lactams endowed with high conformational adaptability should more easily form acyl-enzyme complexes with PBP2a than the traditional antibiotics, we have prepared a series of bis-2-oxo-azetidinyl macrocycles as potential inhibitors. The compounds are formally "head-head" (HH) cyclodimers of 1-(ω-alkenoyl)-3-(S)-(ω'-alkenoylamino)-2-azetidinones, with various lengths of the alkene chains, obtained by two successive metathesis reactions using the Grubbs catalyst. All compounds behave as acylating inhibitors of PBP2a and one β-lactam (5c), embedded into the largest ring (32 atoms), features an activity close to that of Ceftobiprole. Conformational analyses, theoretical reactivity models and docking experiments in PBP2a cavity allow to propose a novel pharmacophore, i.e. the 3-(S)-acylamino-1-acyl-2-azetidinone ring, with the syn-conformation of the imide function, associated to a flexible macrocycle favoring the opening of the active site.
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Affiliation(s)
- Georges Dive
- Université de Liège (ULg), Centre d'Ingénierie des Protéines (CIP), Bâtiment B6, Allée du 6 Août, Sart-Tilman, B-4000 Liège, Belgium
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12
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Development of new drugs for an old target: the penicillin binding proteins. Molecules 2012; 17:12478-505. [PMID: 23095893 PMCID: PMC6268044 DOI: 10.3390/molecules171112478] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Revised: 10/05/2012] [Accepted: 10/17/2012] [Indexed: 11/16/2022] Open
Abstract
The widespread use of β-lactam antibiotics has led to the worldwide appearance of drug-resistant strains. Bacteria have developed resistance to β-lactams by two main mechanisms: the production of β-lactamases, sometimes accompanied by a decrease of outer membrane permeability, and the production of low-affinity, drug resistant Penicillin Binding Proteins (PBPs). PBPs remain attractive targets for developing new antibiotic agents because they catalyse the last steps of the biosynthesis of peptidoglycan, which is unique to bacteria, and lies outside the cytoplasmic membrane. Here we summarize the “current state of the art” of non-β-lactam inhibitors of PBPs, which have being developed in an attempt to counter the emergence of β-lactam resistance. These molecules are not susceptible to hydrolysis by β-lactamases and thus present a real alternative to β-lactams. We present transition state analogs such as boronic acids, which can covalently bind to the active serine residue in the catalytic site. Molecules containing ring structures different from the β-lactam-ring like lactivicin are able to acylate the active serine residue. High throughput screening methods, in combination with virtual screening methods and structure based design, have allowed the development of new molecules. Some of these novel inhibitors are active against major pathogens, including methicillin-resistant Staphylococcus aureus (MRSA) and thus open avenues new for the discovery of novel antibiotics.
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