1
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Kherroubi L, Bacon J, Rahman KM. Navigating fluoroquinolone resistance in Gram-negative bacteria: a comprehensive evaluation. JAC Antimicrob Resist 2024; 6:dlae127. [PMID: 39144447 PMCID: PMC11323783 DOI: 10.1093/jacamr/dlae127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Accepted: 07/04/2024] [Indexed: 08/16/2024] Open
Abstract
Since the introduction of quinolone and fluoroquinolone antibiotics to treat bacterial infections in the 1960s, there has been a pronounced increase in the number of bacterial species that have developed resistance to fluoroquinolone treatment. In 2017, the World Health Organization established a priority list of the most critical Gram-negative resistant pathogens. These included Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Escherichia coli. In the last three decades, investigations into the mechanisms of fluoroquinolone resistance have revealed that mutations in the target enzymes of fluoroquinolones, DNA gyrase or topoisomerase IV, are the most prevalent mechanism conferring high levels of resistance. Alterations to porins and efflux pumps that facilitate fluoroquinolone permeation and extrusion across the bacterial cell membrane also contribute to the development of resistance. However, there is a growing observation of novel mutants with newer generations of fluoroquinolones, highlighting the need for novel treatments. Currently, steady progress has been made in the development of novel antimicrobial agents that target DNA gyrase or topoisomerase IV through different avenues than current fluoroquinolones to prevent target-mediated resistance. Therefore, an updated review of the current understanding of fluoroquinolone resistance within the literature is imperative to aid in future investigations.
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Affiliation(s)
- Linda Kherroubi
- School of Cancer and Pharmaceutical Science, King’s College London, London SE1 9NH, UK
| | - Joanna Bacon
- Discovery Group, Vaccine Development and Evaluation Centre, UK Health Security Agency, Porton Down, Salisbury SP4 0JG, UK
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2
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Lyons A, Kirkham J, Blades K, Orr D, Dauncey E, Smith O, Dick E, Walker R, Matthews T, Bunt A, Finlayson J, Morrison I, Savage VJ, Moyo E, Butler HS, Newman R, Ooi N, Smith A, Charrier C, Ratcliffe AJ, Stokes NR, Best S, Salisbury AM, Craighead M, Cooper IR. Discovery and structure-activity relationships of a novel oxazolidinone class of bacterial type II topoisomerase inhibitors. Bioorg Med Chem Lett 2022; 65:128648. [PMID: 35231579 DOI: 10.1016/j.bmcl.2022.128648] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 02/22/2022] [Accepted: 02/24/2022] [Indexed: 11/02/2022]
Abstract
There is an increasingly urgent and unmet medical need for novel antibiotic drugs that tackle infections caused by multidrug-resistant (MDR) pathogens. Novel bacterial type II topoisomerase inhibitors (NBTIs) are of high interest due to limited cross-resistance with fluoroquinolones, however analogues with Gram-negative activity often suffer from hERG channel inhibition. A novel series of bicyclic-oxazolidinone inhibitors of bacterial type II topoisomerase were identified which display potent broad-spectrum anti-bacterial activity, including against MDR strains, along with an encouraging in vitro safety profile. In vivo proof of concept was achieved in a A. baumannii mouse thigh infection model.
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Affiliation(s)
- Amanda Lyons
- Redx Anti-Infectives Ltd, Alderley Park, Cheshire SK10 4TG, UK
| | - James Kirkham
- Infex Therapeutics Ltd, Mereside, Alderley Park, Macclesfield SK10 4TG,UK
| | - Kevin Blades
- Infex Therapeutics Ltd, Mereside, Alderley Park, Macclesfield SK10 4TG,UK
| | - David Orr
- Infex Therapeutics Ltd, Mereside, Alderley Park, Macclesfield SK10 4TG,UK
| | | | - Oliver Smith
- Infex Therapeutics Ltd, Mereside, Alderley Park, Macclesfield SK10 4TG,UK
| | - Emma Dick
- Redx Anti-Infectives Ltd, Alderley Park, Cheshire SK10 4TG, UK
| | - Rolf Walker
- Redx Anti-Infectives Ltd, Alderley Park, Cheshire SK10 4TG, UK
| | - Teresa Matthews
- Redx Anti-Infectives Ltd, Alderley Park, Cheshire SK10 4TG, UK
| | - Adam Bunt
- Infex Therapeutics Ltd, Mereside, Alderley Park, Macclesfield SK10 4TG,UK
| | | | - Ian Morrison
- Redx Anti-Infectives Ltd, Alderley Park, Cheshire SK10 4TG, UK
| | - Victoria J Savage
- Infex Therapeutics Ltd, Mereside, Alderley Park, Macclesfield SK10 4TG,UK
| | - Emmanuel Moyo
- Infex Therapeutics Ltd, Mereside, Alderley Park, Macclesfield SK10 4TG,UK
| | - Hayley S Butler
- Redx Anti-Infectives Ltd, Alderley Park, Cheshire SK10 4TG, UK
| | - Rebecca Newman
- Infex Therapeutics Ltd, Mereside, Alderley Park, Macclesfield SK10 4TG,UK
| | - Nicola Ooi
- Infex Therapeutics Ltd, Mereside, Alderley Park, Macclesfield SK10 4TG,UK
| | - Andrew Smith
- Redx Anti-Infectives Ltd, Alderley Park, Cheshire SK10 4TG, UK
| | - Cédric Charrier
- Redx Anti-Infectives Ltd, Alderley Park, Cheshire SK10 4TG, UK
| | | | - Neil R Stokes
- Redx Anti-Infectives Ltd, Alderley Park, Cheshire SK10 4TG, UK
| | - Stuart Best
- Redx Anti-Infectives Ltd, Alderley Park, Cheshire SK10 4TG, UK
| | | | - Mark Craighead
- Redx Anti-Infectives Ltd, Alderley Park, Cheshire SK10 4TG, UK
| | - Ian R Cooper
- Infex Therapeutics Ltd, Mereside, Alderley Park, Macclesfield SK10 4TG,UK.
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3
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Yan K, Stanley M, Kowalski B, Raimi OG, Ferenbach AT, Wei P, Fang W, van Aalten DMF. Genetic validation of Aspergillus fumigatus phosphoglucomutase as a viable therapeutic target in invasive aspergillosis. J Biol Chem 2022; 298:102003. [PMID: 35504355 PMCID: PMC9168620 DOI: 10.1016/j.jbc.2022.102003] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 04/27/2022] [Accepted: 04/28/2022] [Indexed: 02/09/2023] Open
Abstract
Aspergillus fumigatus is the causative agent of invasive aspergillosis, an infection with mortality rates of up to 50%. The glucan-rich cell wall of A. fumigatus is a protective structure that is absent from human cells and is a potential target for antifungal treatments. Glucan is synthesized from the donor uridine diphosphate glucose, with the conversion of glucose-6-phosphate to glucose-1-phosphate by the enzyme phosphoglucomutase (PGM) representing a key step in its biosynthesis. Here, we explore the possibility of selectively targeting A. fumigatus PGM (AfPGM) as an antifungal treatment strategy. Using a promoter replacement strategy, we constructed a conditional pgm mutant and revealed that pgm is required for A. fumigatus growth and cell wall integrity. In addition, using a fragment screen, we identified the thiol-reactive compound isothiazolone fragment of PGM as targeting a cysteine residue not conserved in the human ortholog. Furthermore, through scaffold exploration, we synthesized a para-aryl derivative (ISFP10) and demonstrated that it inhibits AfPGM with an IC50 of 2 μM and exhibits 50-fold selectivity over the human enzyme. Taken together, our data provide genetic validation of PGM as a therapeutic target and suggest new avenues for inhibiting AfPGM using covalent inhibitors that could serve as tools for chemical validation.
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Affiliation(s)
- Kaizhou Yan
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Mathew Stanley
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Bartosz Kowalski
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Olawale G Raimi
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Andrew T Ferenbach
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Pingzhen Wei
- National Engineering Research Center for Non-Food Biorefinery, Guangxi Academy of Sciences, Nanning, China
| | - Wenxia Fang
- National Engineering Research Center for Non-Food Biorefinery, Guangxi Academy of Sciences, Nanning, China
| | - Daan M F van Aalten
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom.
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4
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Verderosa A, Hawas S, Harris J, Totsika M, Fairfull-Smith KE. Isothiazolone-Nitroxide Hybrids with Activity against Antibiotic-Resistant Staphylococcus aureus Biofilms. ACS OMEGA 2022; 7:5300-5310. [PMID: 35187345 PMCID: PMC8851655 DOI: 10.1021/acsomega.1c06433] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Accepted: 01/20/2022] [Indexed: 06/14/2023]
Abstract
Isothiazolones are widely used as biocides in industrial processing systems and personal care products, but their use to treat infections in humans has been hampered by their inherent cytotoxicity. Herein, we report a strategy to alleviate isothiazolone toxicity and improve antibacterial and antibiofilm potency by functionalization with a nitroxide moiety. Isothiazolone-nitroxide hybrids 6 and 22 were prepared over three steps in moderate yields (58 and 36%, respectively) from (Z)-3-(benzylsulfanyl)-propenoic acid. Hybrid 22 displayed better activity (minimum inhibitory concentration (MIC) = 35 μM) than the widely used methylisothiazolinone (MIT 1, MIC = 280 μM) against methicillin-susceptible Staphylococcus aureus (MSSA). Hybrid 22 was even more active against drug-resistant strains, such as vancomycin-resistant Staphylococcus aureus (VRSA, MIC = 8.75 μM) over MIT 1 (MIC = 280 μM). The enhanced antibacterial activity of hybrid 22 over MIT 1 was retained against established MSSA and VRSA biofilms, with minimum biofilm eradication concentration (MBEC) values of 35 and 70 μM, respectively, for 22 (the MBEC value for MIT 1 against both strains was ≥280 μM). No toxicity was observed in human epithelial T24 cells treated with hybrid 22 in concentrations up to 560 μM using a lactate dehydrogenase assay.
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Affiliation(s)
- Anthony
D. Verderosa
- School
of Biomedical Sciences, Centre for Immunology and Infection Control,
Faculty of Health, Queensland University
of Technology, 300 Herston Rd, Brisbane, Queensland 4006, Australia
| | - Sophia Hawas
- School
of Biomedical Sciences, Centre for Immunology and Infection Control,
Faculty of Health, Queensland University
of Technology, 300 Herston Rd, Brisbane, Queensland 4006, Australia
| | - Jessica Harris
- School
of Chemistry and Physics, Centre for Materials Science, Faculty of
Science, Queensland University of Technology, 2 George St, Brisbane, Queensland 4001, Australia
| | - Makrina Totsika
- School
of Biomedical Sciences, Centre for Immunology and Infection Control,
Faculty of Health, Queensland University
of Technology, 300 Herston Rd, Brisbane, Queensland 4006, Australia
| | - Kathryn E. Fairfull-Smith
- School
of Chemistry and Physics, Centre for Materials Science, Faculty of
Science, Queensland University of Technology, 2 George St, Brisbane, Queensland 4001, Australia
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5
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Ceramella J, Mariconda A, Iacopetta D, Saturnino C, Barbarossa A, Caruso A, Rosano C, Sinicropi MS, Longo P. From coins to cancer therapy: Gold, silver and copper complexes targeting human topoisomerases. Bioorg Med Chem Lett 2019; 30:126905. [PMID: 31874823 DOI: 10.1016/j.bmcl.2019.126905] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 12/07/2019] [Accepted: 12/09/2019] [Indexed: 02/07/2023]
Abstract
Cancer is a complex issue and, even though the prevention basics and therapy have been implemented, it is still the second leading death cause worldwide. With the hope to discover new powerful and safer molecules to fight cancer, many researchers focused their attention on metal-based compounds, starting from the most famous and successfully employed anticancer drug, i.e. cisplatin. The current article aims to report the most recent discoveries about the use of gold, silver and copper complexes as antitumor agents, highlighting their influences on important enzymes, namely human topoisomerases. The latter are fundamental for the cell life and, if overexpressed, strongly implicated in cancer onset and progression. The identification of lead complexes targeting human topoisomerases and gifted with the appropriate chemical and pharmacological properties represents a fecund starting point to obtain new and more effective anticancer molecules.
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Affiliation(s)
- Jessica Ceramella
- Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, 87036 Arcavacata di Rende, CS, Italy
| | | | - Domenico Iacopetta
- Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, 87036 Arcavacata di Rende, CS, Italy.
| | - Carmela Saturnino
- Department of Science, University of Basilicata, 85100 Potenza, Italy
| | - Alexia Barbarossa
- Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, 87036 Arcavacata di Rende, CS, Italy
| | - Anna Caruso
- Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, 87036 Arcavacata di Rende, CS, Italy
| | - Camillo Rosano
- Biopolymers and Proteomics IRCCS, Ospedale Policlinico San Martino - IST, 16132 Genova, Italy
| | - Maria Stefania Sinicropi
- Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, 87036 Arcavacata di Rende, CS, Italy
| | - Pasquale Longo
- Department of Biology and Chemistry, University of Salerno, 84084 Fisciano, Italy
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6
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Luna BL, Garcia JA, Huang M, Ewing PJ, Valentine SC, Chu YM, Ye QZ, Xu HH. Identification and characterization of novel isothiazolones with potent bactericidal activity against multi-drug resistant Acinetobacter baumannii clinical isolates. Int J Antimicrob Agents 2018; 53:474-482. [PMID: 30593847 DOI: 10.1016/j.ijantimicag.2018.12.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 12/10/2018] [Accepted: 12/15/2018] [Indexed: 11/27/2022]
Abstract
Acinetobacter baumannii has emerged as a globally important nosocomial pathogen characterized by an increased multi-drug resistance (MDR), leaving limited options for treating its infection. To identify novel antibacterial compounds with activity against clinical isolates of A. baumannii, we performed high-throughput screening against a chemical library of 42,944 compounds using nonpathogenic Escherichia coli MG1655 and identified 55 hit compounds. The antibacterial activities of 30 pure compounds were determined against MDR clinical isolates of A. baumannii obtained from Los Angeles County hospitals. Two isothiazolones identified, 5-chloro-2-(4-chloro-3-methylphenyl)-4-methyl-3(2H)-isothiazolone (Compound 6) and 5-chloro-2-(4-chlorophenyl)-4-methyl-3(2H)-isothiazolone (Compound 7), possess novel structure and exhibited consistent, potent and cidal activity against all 46 MDR A. baumannii clinical isolates and reference strains. Additionally, structure-activity relationship analysis involving several additional isothiazolones supports the link between a chloro-group on the heterocyclic ring or a fused benzene ring and the cidal activity. Attempts to obtain isothiazolone resistant mutants failed, consistent with the rapid cidal action and indicative of a complex mechanism of action. While cytotoxicity was observed with Compound 7, it had a therapeutic index value of 28 suggesting future therapeutic potential. Our results indicate that high-throughput screening of compound libraries followed by in vitro biological evaluations is a viable approach for the discovery of novel antibacterial agents to contribute in the fight against MDR bacterial pathogens.
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Affiliation(s)
- Breanna L Luna
- Department of Biological Sciences, California State University, Los Angeles, 5151 State University Drive, Los Angeles, CA 90032, USA
| | - Javier A Garcia
- Department of Biological Sciences, California State University, Los Angeles, 5151 State University Drive, Los Angeles, CA 90032, USA
| | - Min Huang
- High Throughput Screening Laboratory and Department of Medicinal Chemistry, University of Kansas, 1501 Wakarusa Drive, Lawrence, KS 66045, USA
| | - Peter J Ewing
- Department of Biological Sciences, California State University, Los Angeles, 5151 State University Drive, Los Angeles, CA 90032, USA
| | - Sonya C Valentine
- Department of Biological Sciences, California State University, Los Angeles, 5151 State University Drive, Los Angeles, CA 90032, USA
| | - Yi-Ming Chu
- Department of Biological Sciences, California State University, Los Angeles, 5151 State University Drive, Los Angeles, CA 90032, USA
| | - Qi-Zhuang Ye
- High Throughput Screening Laboratory and Department of Medicinal Chemistry, University of Kansas, 1501 Wakarusa Drive, Lawrence, KS 66045, USA; School of Medicine, Shenzhen University, 3688 Nanhai Avenue, Shenzhen, Guangdong 518060, China
| | - H Howard Xu
- Department of Biological Sciences, California State University, Los Angeles, 5151 State University Drive, Los Angeles, CA 90032, USA.
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7
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Gerasyuto AI, Arnold MA, Wang J, Chen G, Zhang X, Smith S, Woll MG, Baird J, Zhang N, Almstead NG, Narasimhan J, Peddi S, Dumble M, Sheedy J, Weetall M, Branstrom AA, Prasad JVN, Karp GM. Discovery and Optimization of Indolyl-Containing 4-Hydroxy-2-Pyridone Type II DNA Topoisomerase Inhibitors Active against Multidrug Resistant Gram-negative Bacteria. J Med Chem 2018; 61:4456-4475. [PMID: 29727185 PMCID: PMC5991783 DOI: 10.1021/acs.jmedchem.8b00114] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
There exists an urgent medical need to identify new chemical entities (NCEs) targeting multidrug resistant (MDR) bacterial infections, particularly those caused by Gram-negative pathogens. 4-Hydroxy-2-pyridones represent a novel class of nonfluoroquinolone inhibitors of bacterial type II topoisomerases active against MDR Gram-negative bacteria. Herein, we report on the discovery and structure-activity relationships of a series of fused indolyl-containing 4-hydroxy-2-pyridones with improved in vitro antibacterial activity against fluoroquinolone resistant strains. Compounds 6o and 6v are representative of this class, targeting both bacterial DNA gyrase and topoisomerase IV (Topo IV). In an abbreviated susceptibility screen, compounds 6o and 6v showed improved MIC90 values against Escherichia coli (0.5-1 μg/mL) and Acinetobacter baumannii (8-16 μg/mL) compared to the precursor compounds. In a murine septicemia model, both compounds showed complete protection in mice infected with a lethal dose of E. coli.
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Affiliation(s)
- Aleksey I Gerasyuto
- PTC Therapeutics, Inc. , 100 Corporate Court , South Plainfield , New Jersey 07080 , United States
| | - Michael A Arnold
- PTC Therapeutics, Inc. , 100 Corporate Court , South Plainfield , New Jersey 07080 , United States
| | - Jiashi Wang
- PTC Therapeutics, Inc. , 100 Corporate Court , South Plainfield , New Jersey 07080 , United States
| | - Guangming Chen
- PTC Therapeutics, Inc. , 100 Corporate Court , South Plainfield , New Jersey 07080 , United States
| | - Xiaoyan Zhang
- PTC Therapeutics, Inc. , 100 Corporate Court , South Plainfield , New Jersey 07080 , United States
| | - Sean Smith
- PTC Therapeutics, Inc. , 100 Corporate Court , South Plainfield , New Jersey 07080 , United States
| | - Matthew G Woll
- PTC Therapeutics, Inc. , 100 Corporate Court , South Plainfield , New Jersey 07080 , United States
| | - John Baird
- PTC Therapeutics, Inc. , 100 Corporate Court , South Plainfield , New Jersey 07080 , United States
| | - Nanjing Zhang
- PTC Therapeutics, Inc. , 100 Corporate Court , South Plainfield , New Jersey 07080 , United States
| | - Neil G Almstead
- PTC Therapeutics, Inc. , 100 Corporate Court , South Plainfield , New Jersey 07080 , United States
| | - Jana Narasimhan
- PTC Therapeutics, Inc. , 100 Corporate Court , South Plainfield , New Jersey 07080 , United States
| | - Srinivasa Peddi
- PTC Therapeutics, Inc. , 100 Corporate Court , South Plainfield , New Jersey 07080 , United States
| | - Melissa Dumble
- PTC Therapeutics, Inc. , 100 Corporate Court , South Plainfield , New Jersey 07080 , United States
| | - Josephine Sheedy
- PTC Therapeutics, Inc. , 100 Corporate Court , South Plainfield , New Jersey 07080 , United States
| | - Marla Weetall
- PTC Therapeutics, Inc. , 100 Corporate Court , South Plainfield , New Jersey 07080 , United States
| | - Arthur A Branstrom
- PTC Therapeutics, Inc. , 100 Corporate Court , South Plainfield , New Jersey 07080 , United States
| | - J V N Prasad
- PTC Therapeutics, Inc. , 100 Corporate Court , South Plainfield , New Jersey 07080 , United States
| | - Gary M Karp
- PTC Therapeutics, Inc. , 100 Corporate Court , South Plainfield , New Jersey 07080 , United States
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8
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Badshah SL, Ullah A. New developments in non-quinolone-based antibiotics for the inhibiton of bacterial gyrase and topoisomerase IV. Eur J Med Chem 2018; 152:393-400. [DOI: 10.1016/j.ejmech.2018.04.059] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 04/23/2018] [Accepted: 04/29/2018] [Indexed: 01/06/2023]
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9
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Selenazolinium Salts as "Small Molecule Catalysts" with High Potency against ESKAPE Bacterial Pathogens. Molecules 2017; 22:molecules22122174. [PMID: 29292789 PMCID: PMC6149925 DOI: 10.3390/molecules22122174] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 11/29/2017] [Accepted: 12/05/2017] [Indexed: 12/25/2022] Open
Abstract
In view of the pressing need to identify new antibacterial agents able to combat multidrug-resistant bacteria, we investigated a series of fused selenazolinium derivatives (1–8) regarding their in vitro antimicrobial activities against 25 ESKAPE-pathogen strains. Ebselen was used as reference compound. Most of the selenocompounds demonstrated an excellent in vitro activity against all S. aureus strains, with activities comparable to or even exceeding the one of ebselen. In contrast to ebselen, some selenazolinium derivatives (1, 3, and 7) even displayed significant actions against all Gram-negative pathogens tested. The 3-bromo-2-(1-hydroxy-1-methylethyl)[1,2]selenazolo[2,3-a]pyridinium chloride (1) was particularly active (minimum inhibitory concentrations, MICs: 0.31–1.24 µg/mL for MRSA, and 0.31–2.48 µg/mL for Gram-negative bacteria) and devoid of any significant mutagenicity in the Ames assay. Our preliminary mechanistic studies in cell culture indicated that their mode of action is likely to be associated with an alteration of intracellular levels of glutathione and cysteine thiols of different proteins in the bacterial cells, hence supporting the idea that such compounds interact with the intracellular thiolstat. This alteration of pivotal cysteine residues is most likely the result of a direct or catalytic oxidative modification of such residues by the highly reactive selenium species (RSeS) employed.
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10
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Arnold MA, Gerasyuto AI, Wang J, Du W, Gorske YJK, Arasu T, Baird J, Almstead NG, Narasimhan J, Peddi S, Ginzburg O, Lue SW, Hedrick J, Sheedy J, Lagaud G, Branstrom AA, Weetall M, Prasad JVNV, Karp GM. 4-Hydroxy-2-pyridones: Discovery and evaluation of a novel class of antibacterial agents targeting DNA synthesis. Bioorg Med Chem Lett 2017; 27:5014-5021. [PMID: 29032026 DOI: 10.1016/j.bmcl.2017.10.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 09/27/2017] [Accepted: 10/04/2017] [Indexed: 01/01/2023]
Abstract
The continued emergence of bacteria resistant to current standard of care antibiotics presents a rapidly growing threat to public health. New chemical entities (NCEs) to treat these serious infections are desperately needed. Herein we report the discovery, synthesis, SAR and in vivo efficacy of a novel series of 4-hydroxy-2-pyridones exhibiting activity against Gram-negative pathogens. Compound 1c, derived from the N-debenzylation of 1b, preferentially inhibits bacterial DNA synthesis as determined by standard macromolecular synthesis assays. The structural features of the 4-hydroxy-2-pyridone scaffold required for antibacterial activity were explored and compound 6q, identified through further optimization of the series, had an MIC90 value of 8 μg/mL against a panel of highly resistant strains of E. coli. In a murine septicemia model, compound 6q exhibited a PD50 of 8 mg/kg in mice infected with a lethal dose of E. coli. This novel series of 4-hydroxy-2-pyridones serves as an excellent starting point for the identification of NCEs treating Gram-negative infections.
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Affiliation(s)
- Michael A Arnold
- PTC Therapeutics, Inc., 100 Corporate Court, South Plainfield, NJ 07080, USA.
| | - Aleksey I Gerasyuto
- PTC Therapeutics, Inc., 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Jiashi Wang
- PTC Therapeutics, Inc., 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Wu Du
- PTC Therapeutics, Inc., 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Yi Jin Kim Gorske
- PTC Therapeutics, Inc., 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Tamil Arasu
- PTC Therapeutics, Inc., 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - John Baird
- PTC Therapeutics, Inc., 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Neil G Almstead
- PTC Therapeutics, Inc., 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Jana Narasimhan
- PTC Therapeutics, Inc., 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Srinivasa Peddi
- PTC Therapeutics, Inc., 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Olya Ginzburg
- PTC Therapeutics, Inc., 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Stanley W Lue
- PTC Therapeutics, Inc., 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Jean Hedrick
- PTC Therapeutics, Inc., 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Josephine Sheedy
- PTC Therapeutics, Inc., 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Guy Lagaud
- PTC Therapeutics, Inc., 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Arthur A Branstrom
- PTC Therapeutics, Inc., 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Marla Weetall
- PTC Therapeutics, Inc., 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - J V N Vara Prasad
- PTC Therapeutics, Inc., 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Gary M Karp
- PTC Therapeutics, Inc., 100 Corporate Court, South Plainfield, NJ 07080, USA
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