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Zhou JL, Chen HH, Xu J, Huang MY, Wang JF, Shen HJ, Shen SX, Gao CX, Qian CD. Myricetin Acts as an Inhibitor of Type II NADH Dehydrogenase from Staphylococcus aureus. Molecules 2024; 29:2354. [PMID: 38792214 PMCID: PMC11124336 DOI: 10.3390/molecules29102354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2024] [Revised: 05/09/2024] [Accepted: 05/10/2024] [Indexed: 05/26/2024] Open
Abstract
BACKGROUND Staphylococcus aureus is a common pathogenic microorganism in humans and animals. Type II NADH oxidoreductase (NDH-2) is the only NADH:quinone oxidoreductase present in this organism and represents a promising target for the development of anti-staphylococcal drugs. Recently, myricetin, a natural flavonoid from vegetables and fruits, was found to be a potential inhibitor of NDH-2 of S. aureus. The objective of this study was to evaluate the inhibitory properties of myricetin against NDH-2 and its impact on the growth and expression of virulence factors in S. aureus. RESULTS A screening method was established to identify effective inhibitors of NDH-2, based on heterologously expressed S. aureus NDH-2. Myricetin was found to be an effective inhibitor of NDH-2 with a half maximal inhibitory concentration (IC50) of 2 μM. In silico predictions and enzyme inhibition kinetics further characterized myricetin as a competitive inhibitor of NDH-2 with respect to the substrate menadione (MK). The minimum inhibitory concentrations (MICs) of myricetin against S. aureus strains ranged from 64 to 128 μg/mL. Time-kill assays showed that myricetin was a bactericidal agent against S. aureus. In line with being a competitive inhibitor of the NDH-2 substrate MK, the anti-staphylococcal activity of myricetin was antagonized by MK-4. In addition, myricetin was found to inhibit the gene expression of enterotoxin SeA and reduce the hemolytic activity induced by S. aureus culture on rabbit erythrocytes in a dose-dependent manner. CONCLUSIONS Myricetin was newly discovered to be a competitive inhibitor of S. aureus NDH-2 in relation to the substrate MK. This discovery offers a fresh perspective on the anti-staphylococcal activity of myricetin.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Chao-Dong Qian
- College of Life Sciences, Zhejiang Chinese Medical University, Hangzhou 310053, China; (J.-L.Z.); (H.-H.C.); (J.X.); (M.-Y.H.); (J.-F.W.); (H.-J.S.); (S.-X.S.); (C.-X.G.)
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2
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Ibrahim MK, Haria A, Mehta NV, Degani MS. Antimicrobial potential of quaternary phosphonium salt compounds: a review. Future Med Chem 2023; 15:2113-2141. [PMID: 37929337 DOI: 10.4155/fmc-2023-0188] [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: 06/30/2023] [Accepted: 09/11/2023] [Indexed: 11/07/2023] Open
Abstract
Given that mitochondrial dysregulation is a biomarker of many cancers, cationic quaternary phosphonium salt (QPS) conjugation is a widely utilized strategy for anticancer drug design. QPS-conjugated compounds exhibit greater cell permeation and accumulation in negatively charged mitochondria, and thus, show enhanced activity. Phylogenetic similarities between mitochondria and bacteria have provided a rationale for exploring the antibacterial properties of mitochondria-targeted compounds. Additionally, due to the importance of mitochondria in the survival of pathogenic microbes, including fungi and parasites, this strategy can be extended to these organisms as well. This review examines recent literature on the antimicrobial activities of various QPS-conjugated compounds and provides future directions for exploring the medicinal chemistry of these compounds.
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Affiliation(s)
- Mahin K Ibrahim
- Department of Pharmaceutical Sciences & Technology, Institute of Chemical Technology, Nathalal Parekh Marg, Mumbai, 400019, Maharashtra, India
| | - Akash Haria
- Department of Pharmaceutical Sciences & Technology, Institute of Chemical Technology, Nathalal Parekh Marg, Mumbai, 400019, Maharashtra, India
| | - Namrashee V Mehta
- Department of Pharmaceutical Sciences & Technology, Institute of Chemical Technology, Nathalal Parekh Marg, Mumbai, 400019, Maharashtra, India
| | - Mariam S Degani
- Department of Pharmaceutical Sciences & Technology, Institute of Chemical Technology, Nathalal Parekh Marg, Mumbai, 400019, Maharashtra, India
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3
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Kumar G, Adhikrao PA. Targeting Mycobacterium tuberculosis iron-scavenging tools: a recent update on siderophores inhibitors. RSC Med Chem 2023; 14:1885-1913. [PMID: 37859726 PMCID: PMC10583813 DOI: 10.1039/d3md00201b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 08/22/2023] [Indexed: 10/21/2023] Open
Abstract
Among the various bacterial infections, tuberculosis (TB) remains a life-threatening infectious disease responsible as the most significant cause of mortality and morbidity worldwide. The co-infection of human immunodeficiency virus (HIV) in association with TB burdens the healthcare system substantially. Notably, M.tb possesses defence against most antitubercular antibiotic drugs, and the efficacy of existing frontline anti-TB drugs is waning. Also, new and recurring cases of TB from resistant bacteria such as multidrug-resistant TB (MDR), extensively drug-resistant TB (XDR), and totally drug-resistant TB (TDR) strains are increasing. Hence, TB begs the scientific community to explore the new therapeutic class of compounds with their novel mechanism. M.tb requires iron from host cells to sustain, grow, and carry out several biological processes. M.tb has developed strategic methods of acquiring iron from the surrounding environment. In this communication, we discuss an overview of M.tb iron-scavenging tools. Also, we have summarized recently identified MbtA and MbtI inhibitors, which prevent M.tb from scavenging iron. These iron-scavenging tool inhibitors have the potential to be developed as anti-TB agents/drugs.
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Affiliation(s)
- Gautam Kumar
- Department of Natural Products, Chemical Sciences, National Institute of Pharmaceutical Education and Research-Hyderabad (NIPER-Hyderabad) Balanagar Hyderabad 500037 India
| | - Patil Amruta Adhikrao
- Department of Natural Products, Chemical Sciences, National Institute of Pharmaceutical Education and Research-Hyderabad (NIPER-Hyderabad) Balanagar Hyderabad 500037 India
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4
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Fridianto KT, Gunawan GA, Hards K, Sarathy JP, Cook GM, Dick T, Go ML, Lam Y. Alkyltriphenylphosphonium turns naphthoquinoneimidazoles into potent membrane depolarizers against mycobacteria. RSC Med Chem 2022; 13:1605-1613. [PMID: 36545436 PMCID: PMC9749938 DOI: 10.1039/d2md00251e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 10/10/2022] [Indexed: 11/05/2022] Open
Abstract
Due to its central role in energy generation and bacterial viability, mycobacterial bioenergetics is an attractive therapeutic target for anti-tuberculosis drug discovery. Building upon our work on antimycobacterial dioxonaphthoimidazoliums that were activated by a proximal positive charge and generated reactive oxygen species upon reduction by Type II NADH dehydrogenase, we herein studied the effect of a distal positive charge on the antimycobacterial activity of naphthoquinoneimidazoles by incorporating a trialkylphosphonium cation. The potency-enhancing properties of the linker length were affirmed by structure-activity relationship studies. The most active compound against M. tb H37Rv displayed good selectivity index (SI = 34) and strong bactericidal activity in the low micromolar range, which occurred through rapid bacterial membrane depolarization that resulted in depletion of intracellular ATP. Through this work, we demonstrated a switch of the scaffold's mode-of-action via relocation of positive charge while retaining its excellent antibacterial activity and selectivity.
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Affiliation(s)
| | | | - Kiel Hards
- Department of Microbiology and Immunology, University of OtagoDunedin 9054New Zealand
| | - Jickky Palmae Sarathy
- Center for Discovery and Innovation, Hackensack Meridian Health & Department of Medical Sciences, Hackensack Meridian School of Medicine Nutley NJ 071110 USA
| | - Gregory M. Cook
- Department of Microbiology and Immunology, University of OtagoDunedin 9054New Zealand
| | - Thomas Dick
- Center for Discovery and Innovation, Hackensack Meridian Health & Department of Medical Sciences, Hackensack Meridian School of Medicine Nutley NJ 071110 USA .,Department of Microbiology and Immunology, Georgetown University Washington DC USA
| | - Mei-Lin Go
- Department of Pharmacy, National University of Singapore 117543 Singapore
| | - Yulin Lam
- Department of Chemistry, National University of Singapore 117543 Singapore
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5
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McNeil MB, Cheung CY, Waller NJE, Adolph C, Chapman CL, Seeto NEJ, Jowsey W, Li Z, Hameed HMA, Zhang T, Cook GM. Uncovering interactions between mycobacterial respiratory complexes to target drug-resistant Mycobacterium tuberculosis. Front Cell Infect Microbiol 2022; 12:980844. [PMID: 36093195 PMCID: PMC9461714 DOI: 10.3389/fcimb.2022.980844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 08/03/2022] [Indexed: 11/24/2022] Open
Abstract
Mycobacterium tuberculosis remains a leading cause of infectious disease morbidity and mortality for which new drug combination therapies are needed. Mycobacterial bioenergetics has emerged as a promising space for the development of novel therapeutics. Further to this, unique combinations of respiratory inhibitors have been shown to have synergistic or synthetic lethal interactions, suggesting that combinations of bioenergetic inhibitors could drastically shorten treatment times. Realizing the full potential of this unique target space requires an understanding of which combinations of respiratory complexes, when inhibited, have the strongest interactions and potential in a clinical setting. In this review, we discuss (i) chemical-interaction, (ii) genetic-interaction and (iii) chemical-genetic interaction studies to explore the consequences of inhibiting multiple mycobacterial respiratory components. We provide potential mechanisms to describe the basis for the strongest interactions. Finally, whilst we place an emphasis on interactions that occur with existing bioenergetic inhibitors, by highlighting interactions that occur with alternative respiratory components we envision that this information will provide a rational to further explore alternative proteins as potential drug targets and as part of unique drug combinations.
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Affiliation(s)
- Matthew B. McNeil
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
- Maurice Wilkins, Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand
- *Correspondence: Matthew B. McNeil, ; Gregory M. Cook,
| | - Chen-Yi Cheung
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Natalie J. E. Waller
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Cara Adolph
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Cassandra L. Chapman
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Noon E. J. Seeto
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - William Jowsey
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Zhengqiu Li
- School of Pharmacy, Jinan University, Guangzhou, China
| | - H. M. Adnan Hameed
- State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health (GIBH), Chinese Academy of Sciences (CAS), Guangzhou, China
- China-New Zealand Joint Laboratory of Biomedicine and Health, Guangzhou Institutes of Biomedicine and Health (GIBH), Chinese Academy of Sciences (CAS), Guangzhou, China
- Guangdong-Hong Kong-Macau Joint Laboratory of Respiratory Infectious Diseases, Guangzhou, China
- University of Chinese Academy of Sciences (UCAS), Beijing, China
| | - Tianyu Zhang
- State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health (GIBH), Chinese Academy of Sciences (CAS), Guangzhou, China
- China-New Zealand Joint Laboratory of Biomedicine and Health, Guangzhou Institutes of Biomedicine and Health (GIBH), Chinese Academy of Sciences (CAS), Guangzhou, China
- Guangdong-Hong Kong-Macau Joint Laboratory of Respiratory Infectious Diseases, Guangzhou, China
- University of Chinese Academy of Sciences (UCAS), Beijing, China
| | - Gregory M. Cook
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
- Maurice Wilkins, Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand
- *Correspondence: Matthew B. McNeil, ; Gregory M. Cook,
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6
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Modak B, Girkar S, Narayan R, Kapoor S. Mycobacterial Membranes as Actionable Targets for Lipid-Centric Therapy in Tuberculosis. J Med Chem 2022; 65:3046-3065. [PMID: 35133820 DOI: 10.1021/acs.jmedchem.1c01870] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Infectious diseases remain significant health concerns worldwide, and resistance is particularly common in patients with tuberculosis caused by Mycobacterium tuberculosis. The development of anti-infectives with novel modes of action may help overcome resistance. In this regard, membrane-active agents, which modulate membrane components essential for the survival of pathogens, present attractive antimicrobial agents. Key advantages of membrane-active compounds include their ability to target slow-growing or dormant bacteria and their favorable pharmacokinetics. Here, we comprehensively review recent advances in the development of membrane-active chemotypes that target mycobacterial membranes and discuss clinically relevant membrane-active antibacterial agents that have shown promise in counteracting bacterial infections. We discuss the relationship between the membrane properties and the synthetic requirements within the chemical scaffold, as well as the limitations of current membrane-active chemotypes. This review will lay the chemical groundwork for the development of membrane-active antituberculosis agents and will foster the discovery of more effective antitubercular agents.
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Affiliation(s)
- Biswabrata Modak
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai 400076, India
| | - Siddhali Girkar
- School of Chemical and Materials Sciences, Indian Institute of Technology Goa, Goa 403110, India
| | - Rishikesh Narayan
- School of Chemical and Materials Sciences, Indian Institute of Technology Goa, Goa 403110, India
| | - Shobhna Kapoor
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai 400076, India.,Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima 739-8528, Japan
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7
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Development of Phenothiazine Hybrids with Potential Medicinal Interest: A Review. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27010276. [PMID: 35011508 PMCID: PMC8746661 DOI: 10.3390/molecules27010276] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 12/27/2021] [Accepted: 12/29/2021] [Indexed: 12/15/2022]
Abstract
The molecular hybridization approach has been used to develop compounds with improved efficacy by combining two or more pharmacophores of bioactive scaffolds. In this context, hybridization of various relevant pharmacophores with phenothiazine derivatives has resulted in pertinent compounds with diverse biological activities, interacting with specific or multiple targets. In fact, the development of new drugs or drug candidates based on phenothiazine system has been a promising approach due to the diverse activities associated with this tricyclic system, traditionally present in compounds with antipsychotic, antihistaminic and antimuscarinic effects. Actually, the pharmacological actions of phenothiazine hybrids include promising antibacterial, antifungal, anticancer, anti-inflammatory, antimalarial, analgesic and multi-drug resistance reversal properties. The present review summarizes the progress in the development of phenothiazine hybrids and their biological activity.
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8
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Lee BS, Hards K, Engelhart CA, Hasenoehrl EJ, Kalia NP, Mackenzie JS, Sviriaeva E, Chong SMS, Manimekalai MSS, Koh VH, Chan J, Xu J, Alonso S, Miller MJ, Steyn AJC, Grüber G, Schnappinger D, Berney M, Cook GM, Moraski GC, Pethe K. Dual inhibition of the terminal oxidases eradicates antibiotic-tolerant Mycobacterium tuberculosis. EMBO Mol Med 2021; 13:e13207. [PMID: 33283973 PMCID: PMC7799364 DOI: 10.15252/emmm.202013207] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 10/28/2020] [Accepted: 10/30/2020] [Indexed: 11/09/2022] Open
Abstract
The approval of bedaquiline has placed energy metabolism in the limelight as an attractive target space for tuberculosis antibiotic development. While bedaquiline inhibits the mycobacterial F1 F0 ATP synthase, small molecules targeting other components of the oxidative phosphorylation pathway have been identified. Of particular interest is Telacebec (Q203), a phase 2 drug candidate inhibitor of the cytochrome bcc:aa3 terminal oxidase. A functional redundancy between the cytochrome bcc:aa3 and the cytochrome bd oxidase protects M. tuberculosis from Q203-induced death, highlighting the attractiveness of the bd-type terminal oxidase for drug development. Here, we employed a facile whole-cell screen approach to identify the cytochrome bd inhibitor ND-011992. Although ND-011992 is ineffective on its own, it inhibits respiration and ATP homeostasis in combination with Q203. The drug combination was bactericidal against replicating and antibiotic-tolerant, non-replicating mycobacteria, and increased efficacy relative to that of a single drug in a mouse model. These findings suggest that a cytochrome bd oxidase inhibitor will add value to a drug combination targeting oxidative phosphorylation for tuberculosis treatment.
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Affiliation(s)
- Bei Shi Lee
- School of Biological SciencesNanyang Technological UniversitySingaporeSingapore
| | - Kiel Hards
- Department of Microbiology and ImmunologySchool of Biomedical SciencesUniversity of OtagoDunedinNew Zealand
- Maurice Wilkins Centre for Molecular BiodiscoveryUniversity of AucklandAucklandNew Zealand
| | - Curtis A Engelhart
- Department of Microbiology and ImmunologyWeill Cornell Medical CollegeNew YorkNYUSA
| | - Erik J Hasenoehrl
- Department of Microbiology and ImmunologyAlbert Einstein College of MedicineBronxNYUSA
| | - Nitin P Kalia
- Lee Kong Chian School of MedicineNanyang Technological UniversitySingaporeSingapore
- Ramalingaswami FellowClinical Microbiology DivisionCSIR‐IIIMJammu and KashmirIndia
| | - Jared S Mackenzie
- Africa Health Research InstituteNelson R. Mandela School of MedicineUniversity of KwaZulu‐NatalDurbanSouth Africa
| | - Ekaterina Sviriaeva
- School of Biological SciencesNanyang Technological UniversitySingaporeSingapore
| | - Shi Min Sherilyn Chong
- School of Biological SciencesNanyang Technological UniversitySingaporeSingapore
- Nanyang Institute of Technology in Health and MedicineInterdisciplinary Graduate SchoolNanyang Technological UniversitySingaporeSingapore
| | | | - Vanessa H Koh
- Department of MicrobiologyYong Loo Lin School of MedicineNational University of SingaporeSingaporeSingapore
- Infectious Disease ProgrammeDepartment of Microbiology and ImmunologyNational University of SingaporeSingaporeSingapore
| | - John Chan
- Department of MedicineAlbert Einstein College of MedicineBronxNYUSA
| | - Jiayong Xu
- Department of MedicineAlbert Einstein College of MedicineBronxNYUSA
| | - Sylvie Alonso
- Department of MicrobiologyYong Loo Lin School of MedicineNational University of SingaporeSingaporeSingapore
- Infectious Disease ProgrammeDepartment of Microbiology and ImmunologyNational University of SingaporeSingaporeSingapore
| | - Marvin J Miller
- Department of Chemistry and BiochemistryUniversity of Notre DameNotre DameINUSA
| | - Adrie J C Steyn
- Africa Health Research InstituteNelson R. Mandela School of MedicineUniversity of KwaZulu‐NatalDurbanSouth Africa
- Department of MicrobiologyUniversity of AlabamaBirminghamALUSA
| | - Gerhard Grüber
- School of Biological SciencesNanyang Technological UniversitySingaporeSingapore
| | - Dirk Schnappinger
- Department of Microbiology and ImmunologyWeill Cornell Medical CollegeNew YorkNYUSA
| | - Michael Berney
- Department of Microbiology and ImmunologyAlbert Einstein College of MedicineBronxNYUSA
| | - Gregory M Cook
- Department of Microbiology and ImmunologySchool of Biomedical SciencesUniversity of OtagoDunedinNew Zealand
- Maurice Wilkins Centre for Molecular BiodiscoveryUniversity of AucklandAucklandNew Zealand
| | - Garrett C Moraski
- Department of Chemistry and BiochemistryMontana State UniversityBozemanMTUSA
| | - Kevin Pethe
- School of Biological SciencesNanyang Technological UniversitySingaporeSingapore
- Lee Kong Chian School of MedicineNanyang Technological UniversitySingaporeSingapore
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9
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10
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Design and synthesis of phenothiazine based imidazolium ionic liquid for electrochemical nonenzymatic detection of sulfite in food samples. J Mol Liq 2020. [DOI: 10.1016/j.molliq.2019.112412] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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11
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The synthesis and evaluation of quinolinequinones as anti-mycobacterial agents. Bioorg Med Chem 2019; 27:3532-3545. [DOI: 10.1016/j.bmc.2019.06.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2019] [Revised: 05/30/2019] [Accepted: 06/01/2019] [Indexed: 12/30/2022]
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12
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Santoso KT, Cheung CY, Hards K, Cook GM, Stocker BL, Timmer MSM. Synthesis and Investigation of Phthalazinones as Antitubercular Agents. Chem Asian J 2019; 14:1278-1285. [PMID: 30680937 DOI: 10.1002/asia.201801805] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 01/16/2019] [Indexed: 11/08/2022]
Abstract
A series of 2- and 7-substituted phthalazinones was synthesised and their potential as anti-tubercular drugs assessed via Mycobacterium tuberculosis (mc2 6230) growth inhibition assays. All phthalazinones tested showed growth inhibitory activity (MIC <100 μm), and those compounds containing lipophilic and electron-withdrawing groups generally exhibited better anti-tubercular activity. Several lead compounds were identified, including 7-((2-amino-6-(4-fluorophenyl)pyrimidin-4-yl)amino)-2-heptylphthalazin-1(2H)-one (MIC=1.6 μm), 4-tertbutylphthalazin-2(1H)-one (MIC=3 μm), and 7-nitro-phthalazin-1(2H)-one (MIC=3 μm). Mode of action studies indicated that selected pyrimidinyl-phthalazinones may interfere with NADH oxidation, however, the mode of action of the lead compound is independent of this enzyme. MIC=minimum inhibitory concentration.
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Affiliation(s)
- Kristiana T Santoso
- School of Chemical and Physical Sciences, Victoria University of Wellington, P.O. Box 600, 6140, Wellington, New Zealand.,Centre for Biodiscovery, Victoria University of Wellington, P.O. Box 600, 6140, Wellington, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand
| | - Chen-Yi Cheung
- Department of Microbiology and Immunology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Kiel Hards
- Department of Microbiology and Immunology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand
| | - Gregory M Cook
- Department of Microbiology and Immunology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand
| | - Bridget L Stocker
- School of Chemical and Physical Sciences, Victoria University of Wellington, P.O. Box 600, 6140, Wellington, New Zealand.,Centre for Biodiscovery, Victoria University of Wellington, P.O. Box 600, 6140, Wellington, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand
| | - Mattie S M Timmer
- School of Chemical and Physical Sciences, Victoria University of Wellington, P.O. Box 600, 6140, Wellington, New Zealand.,Centre for Biodiscovery, Victoria University of Wellington, P.O. Box 600, 6140, Wellington, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand
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13
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Lee BS, Kalia NP, Jin XEF, Hasenoehrl EJ, Berney M, Pethe K. Inhibitors of energy metabolism interfere with antibiotic-induced death in mycobacteria. J Biol Chem 2018; 294:1936-1943. [PMID: 30530783 PMCID: PMC6369303 DOI: 10.1074/jbc.ra118.005732] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 11/29/2018] [Indexed: 11/17/2022] Open
Abstract
Energy metabolism has recently gained interest as a target space for antibiotic drug development in mycobacteria. Of particular importance is bedaquiline (Sirturo), which kills mycobacteria by inhibiting the F1F0 ATP synthase. Other components of the electron transport chain such as the NADH dehydrogenases (NDH-2 and NdhA) and the terminal respiratory oxidase bc1:aa3 are also susceptible to chemical inhibition. Because antituberculosis drugs are prescribed as part of combination therapies, the interaction between novel drugs targeting energy metabolism and classical first and second line antibiotics must be considered to maximize treatment efficiency. Here, we show that subinhibitory concentration of drugs targeting the F1F0 ATP synthase and the cytochrome bc1:aa3, as well as energy uncouplers, interfere with the bactericidal potency of isoniazid and moxifloxacin. Isoniazid- and moxifloxacin-induced mycobacterial death correlated with a transient increase in intracellular ATP that was dissipated by co-incubation with energy metabolism inhibitors. Although oxidative phosphorylation is a promising target space for drug development, a better understanding of the link between energy metabolism and antibiotic-induced mycobacterial death is essential to develop potent drug combinations for the treatment of tuberculosis.
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Affiliation(s)
- Bei Shi Lee
- From the School of Biological Sciences, Nanyang Technological University, Singapore 637551
| | - Nitin P Kalia
- the Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore 636921, and
| | - Xin Er F Jin
- the Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore 636921, and
| | - Erik J Hasenoehrl
- the Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Michael Berney
- the Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Kevin Pethe
- From the School of Biological Sciences, Nanyang Technological University, Singapore 637551, .,the Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore 636921, and
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14
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Bresolí-Obach R, Gispert I, Peña DG, Boga S, Gulias Ó, Agut M, Vázquez ME, Nonell S. Triphenylphosphonium cation: A valuable functional group for antimicrobial photodynamic therapy. JOURNAL OF BIOPHOTONICS 2018; 11:e201800054. [PMID: 29882394 DOI: 10.1002/jbio.201800054] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Accepted: 06/06/2018] [Indexed: 06/08/2023]
Abstract
Light-mediated killing of pathogens by cationic photosensitisers is a promising antimicrobial approach that avoids the development of resistance inherent to the use of antimicrobials. In this study, we demonstrate that modification of different photosensitisers with the triphenylphosphonium cation yields derivatives with excellent photoantimicrobial activity against Gram-positive bacteria (ie, Staphylococcus aureus and Enterococcus faecalis). Thus, the triphenylphosphonium functional group should be considered for the development of photoantimicrobials for the selective killing of Gram-positive bacteria in the presence of Gram-negative species.
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Affiliation(s)
| | - Ignacio Gispert
- Institut Químic de Sarrià, Universitat Ramon Llull, Barcelona, Spain
| | - Diego G Peña
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS), Departamento de Química Orgánica, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - Sonia Boga
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS), Departamento de Química Orgánica, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - Óscar Gulias
- Institut Químic de Sarrià, Universitat Ramon Llull, Barcelona, Spain
| | - Montserrat Agut
- Institut Químic de Sarrià, Universitat Ramon Llull, Barcelona, Spain
| | - M Eugenio Vázquez
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS), Departamento de Química Orgánica, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - Santi Nonell
- Institut Químic de Sarrià, Universitat Ramon Llull, Barcelona, Spain
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15
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Chen H, Nyantakyi SA, Li M, Gopal P, Aziz DB, Yang T, Moreira W, Gengenbacher M, Dick T, Go ML. The Mycobacterial Membrane: A Novel Target Space for Anti-tubercular Drugs. Front Microbiol 2018; 9:1627. [PMID: 30072978 PMCID: PMC6060259 DOI: 10.3389/fmicb.2018.01627] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 06/28/2018] [Indexed: 01/09/2023] Open
Abstract
Tuberculosis (TB) poses an enduring threat to global health. Consistently ranked among the top 10 causes of death worldwide since 2000, TB has now exceeded HIV-AIDS in terms of deaths inflicted by a single infectious agent. In spite of recently declining TB incident rates, these decreases have been incremental and fall short of threshold levels required to end the global TB epidemic. As in other infectious diseases, the emergence of resistant organisms poses a major impediment to effective TB control. Resistance in mycobacteria may evolve from genetic mutations in target genes which are transmitted during cell multiplication from mother cells to their progeny. A more insidious form of resistance involves sub-populations of non-growing (“dormant”) mycobacterial persisters. Quiescent and genetically identical to their susceptible counterparts, persisters exhibit non-inheritable drug tolerance. Their prevalence account for the protracted treatment period that is required for the treatment of TB. In order to improve the efficacy of treatment against mycobacterial persisters and drug-resistant organisms, novel antitubercular agents are urgently required. Selective targeting of bacterial membranes has been proposed as a viable therapeutic strategy against infectious diseases. The underpinning rationale is that a functionally intact cell membrane is vital for both replicating and dormant bacteria. Perturbing the membrane would thus disrupt a multitude of embedded targets with lethal pleiotropic consequences, besides limiting the emergence of resistant strains. There is growing interest in exploring small molecules as selective disruptors of the mycobacterial membrane. In this review, we examined the recent literature on different chemotypes with membrane perturbing properties, the mechanisms by which they induce membrane disruption and their potential as anti-TB agents. Cationic amphiphilicity is a signature motif that is required of membrane targeting agents but adherence to this broad physical requirement does not necessarily translate to conformity in terms of biological outcomes. Nor does it ensure selective targeting of mycobacterial membranes. These are unresolved issues that require further investigation.
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Affiliation(s)
- Huan Chen
- Department of Pharmacy, Faculty of Science, National University of Singapore, Singapore, Singapore
| | - Samuel A Nyantakyi
- Department of Pharmacy, Faculty of Science, National University of Singapore, Singapore, Singapore
| | - Ming Li
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Pooja Gopal
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Dinah B Aziz
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Tianming Yang
- Department of Pharmacy, Faculty of Science, National University of Singapore, Singapore, Singapore
| | - Wilfried Moreira
- Interdisciplinary Research Group, Singapore-MIT Alliance for Research and Technology, Antimicrobial Resistance Singapore, Singapore, Singapore
| | - Martin Gengenbacher
- Public Health Research Institute, New Jersey Medical School, Rutgers University, Newark, NJ, United States
| | - Thomas Dick
- Public Health Research Institute, New Jersey Medical School, Rutgers University, Newark, NJ, United States
| | - Mei L Go
- Department of Pharmacy, Faculty of Science, National University of Singapore, Singapore, Singapore
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16
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Nyantakyi SA, Li M, Gopal P, Zimmerman M, Dartois V, Gengenbacher M, Dick T, Go ML. Indolyl Azaspiroketal Mannich Bases Are Potent Antimycobacterial Agents with Selective Membrane Permeabilizing Effects and in Vivo Activity. J Med Chem 2018; 61:5733-5750. [PMID: 29894180 DOI: 10.1021/acs.jmedchem.8b00777] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The inclusion of an azaspiroketal Mannich base in the membrane targeting antitubercular 6-methoxy-1- n-octyl-1 H-indole scaffold resulted in analogs with improved selectivity and submicromolar activity against Mycobacterium tuberculosis H37Rv. The potency enhancing properties of the spiro-fused ring motif was affirmed by SAR and validated in a mouse model of tuberculosis. As expected for membrane inserting agents, the indolyl azaspiroketal Mannich bases perturbed phospholipid vesicles, permeabilized bacterial cells, and induced the mycobacterial cell envelope stress reporter promoter p iniBAC. Surprisingly, their membrane disruptive effects did not appear to be associated with bacterial membrane depolarization. This profile was not uniquely associated with azaspiroketal Mannich bases but was characteristic of indolyl Mannich bases as a class. Whereas resistant mycobacteria could not be isolated for a less potent indolyl Mannich base, the more potent azaspiroketal analog displayed low spontaneous resistance mutation frequency of 10-8/CFU. This may indicate involvement of an additional envelope-related target in its mechanism of action.
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Affiliation(s)
- Samuel Agyei Nyantakyi
- Department of Pharmacy , National University of Singapore , 18 Science Drive 4 , 117543 , Singapore
| | - Ming Li
- Department of Medicine , National University of Singapore , 14 Medical Drive , 117599 , Singapore
| | - Pooja Gopal
- Department of Medicine , National University of Singapore , 14 Medical Drive , 117599 , Singapore
| | - Matthew Zimmerman
- Public Health Research Institute, New Jersey Medical School, Rutgers, The State University of New Jersey , 225 Warren Street , Newark , New Jersey 07103-2714 , United States
| | - Véronique Dartois
- Public Health Research Institute, New Jersey Medical School, Rutgers, The State University of New Jersey , 225 Warren Street , Newark , New Jersey 07103-2714 , United States
| | - Martin Gengenbacher
- Public Health Research Institute, New Jersey Medical School, Rutgers, The State University of New Jersey , 225 Warren Street , Newark , New Jersey 07103-2714 , United States
| | - Thomas Dick
- Department of Microbiology and Immunology , National University of Singapore , 5 Science Drive 2 , 117545 , Singapore.,Public Health Research Institute, New Jersey Medical School, Rutgers, The State University of New Jersey , 225 Warren Street , Newark , New Jersey 07103-2714 , United States
| | - Mei-Lin Go
- Department of Pharmacy , National University of Singapore , 18 Science Drive 4 , 117543 , Singapore
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17
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Abstract
Bedaquiline (BDQ), an inhibitor of the mycobacterial F1Fo-ATP synthase, has revolutionized the antitubercular drug discovery program by defining energy metabolism as a potent new target space. Several studies have recently suggested that BDQ ultimately causes mycobacterial cell death through a phenomenon known as uncoupling. The biochemical basis underlying this, in BDQ, is unresolved and may represent a new pathway to the development of effective therapeutics. In this communication, we demonstrate that BDQ can inhibit ATP synthesis in Escherichia coli by functioning as a H+/K+ ionophore, causing transmembrane pH and potassium gradients to be equilibrated. Despite the apparent lack of a BDQ-binding site, incorporating the E. coli Fo subunit into liposomes enhanced the ionophoric activity of BDQ. We discuss the possibility that localization of BDQ at F1Fo-ATP synthases enables BDQ to create an uncoupled microenvironment, by antiporting H+/K+ Ionophoric properties may be desirable in high-affinity antimicrobials targeting integral membrane proteins.
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18
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Oxidative Phosphorylation as a Target Space for Tuberculosis: Success, Caution, and Future Directions. Microbiol Spectr 2017; 5. [PMID: 28597820 DOI: 10.1128/microbiolspec.tbtb2-0014-2016] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The emergence and spread of drug-resistant pathogens, and our inability to develop new antimicrobials to combat resistance, have inspired scientists to seek out new targets for drug development. The Mycobacterium tuberculosis complex is a group of obligately aerobic bacteria that have specialized for inhabiting a wide range of intracellular and extracellular environments. Two fundamental features in this adaptation are the flexible utilization of energy sources and continued metabolism in the absence of growth. M. tuberculosis is an obligately aerobic heterotroph that depends on oxidative phosphorylation for growth and survival. However, several studies are redefining the metabolic breadth of the genus. Alternative electron donors and acceptors may provide the maintenance energy for the pathogen to maintain viability in hypoxic, nonreplicating states relevant to latent infection. This hidden metabolic flexibility may ultimately decrease the efficacy of drugs targeted against primary dehydrogenases and terminal oxidases. However, it may also open up opportunities to develop novel antimycobacterials targeting persister cells. In this review, we discuss the progress in understanding the role of energetic targets in mycobacterial physiology and pathogenesis and the opportunities for drug discovery.
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19
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Li M, Nyantakyi SA, Gopal P, Aziz DB, Dick T, Go ML. Indolylalkyltriphenylphosphonium Analogues Are Membrane-Depolarizing Mycobactericidal Agents. ACS Med Chem Lett 2017; 8:1165-1170. [PMID: 29152049 DOI: 10.1021/acsmedchemlett.7b00287] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Accepted: 10/09/2017] [Indexed: 12/20/2022] Open
Abstract
Agents that selectively target the mycobacterial membrane could potentially shorten treatment time for tuberculosis, reduce relapse, and curtail emergence of resistant strains. The lipophilicity and extensive charge-delocalized state of the triphenylphosphonium cation strongly favor accumulation within bacterial membranes. Here, we explored the antimycobacterial activities and membrane-targeting properties of indolylalkyltriphenylphosphonium analogues. The most active analogues preferentially inhibited growth of Mycobacterium tuberculosis H37Rv (MIC50 2-4 μM) and were bactericidal against Mycobacterium bovis BCG (MBC99 3 μM). In spite of their propensity to accumulate within membranes, we found no evidence that these compounds permeabilized mycobacterial membranes or induced cell-envelope stress. Our investigations indicated that their bacterical effects stem from sustained depolarization of mycobacterial membranes and ensuing disruptive effects on electron transfer and cell division.
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Affiliation(s)
| | - Samuel A. Nyantakyi
- Department
of Pharmacy, Faculty of Science, National University of Singapore, Singapore 117543
| | | | | | - Thomas Dick
- Public
Health Research Institute, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, New Jersey 07103, United States
| | - Mei-Lin Go
- Department
of Pharmacy, Faculty of Science, National University of Singapore, Singapore 117543
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20
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Sellamuthu S, Singh M, Kumar A, Singh SK. Type-II NADH Dehydrogenase (NDH-2): a promising therapeutic target for antitubercular and antibacterial drug discovery. Expert Opin Ther Targets 2017; 21:559-570. [PMID: 28472892 DOI: 10.1080/14728222.2017.1327577] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
INTRODUCTION Tuberculosis (TB) is highly dangerous due to the development of resistance to first-line drugs. Moreover, Mycobacterium tuberculosis (Mtb) has also developed resistance to newly approved antitubercular drug bedaquiline. This necessitates the search for drugs acting on newer molecular targets. The energy metabolism of mycobacteria is the prime focus for the discovery of novel antitubercular drugs. Targeting type-2 NADH dehydrogenase (NDH-2) involved in the production of respiratory ATP could, therefore, be effective in treating the disease. Areas covered: This review describes the energetics of mycobacteria and the role of NDH-2 in ATP synthesis. Special attention has been given for genetic and chemical validations of NDH-2 as a molecular target. The reported kinetics and crystal structures of NDH-2 have been given in detail for better understanding of the enzyme. Expert opinion: NDH-2 is an essential enzyme for ATP synthesis and has a potential role in dormancy and persistence of Mtb. The human counterpart lacks this enzyme and hence NDH-2 inhibitors could have more clinical importance. Phenothiazines are potent inhibitor of NDH-2 and are effective against both drug-susceptible and drug-resistant Mtb. Thus, it is highly desirable to optimize phenothiazine class of compounds for the development of next generation anti-TB drugs.
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Affiliation(s)
- Satheeshkumar Sellamuthu
- a Pharmaceutical Chemistry Research Laboratory, Department of Pharmaceutics , Indian Institute of Technology (Banaras Hindu University) , Varanasi , India
| | - Meenakshi Singh
- a Pharmaceutical Chemistry Research Laboratory, Department of Pharmaceutics , Indian Institute of Technology (Banaras Hindu University) , Varanasi , India
| | - Ashok Kumar
- a Pharmaceutical Chemistry Research Laboratory, Department of Pharmaceutics , Indian Institute of Technology (Banaras Hindu University) , Varanasi , India
| | - Sushil Kumar Singh
- a Pharmaceutical Chemistry Research Laboratory, Department of Pharmaceutics , Indian Institute of Technology (Banaras Hindu University) , Varanasi , India
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21
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Logan A, Murphy MP. Using chemical biology to assess and modulate mitochondria: progress and challenges. Interface Focus 2017; 7:20160151. [PMID: 28382206 PMCID: PMC5311910 DOI: 10.1098/rsfs.2016.0151] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Our understanding of the role of mitochondria in biomedical sciences has expanded considerably over the past decade. In addition to their well-known metabolic roles, mitochondrial are also central to signalling for various processes through the generation of signals such as ROS and metabolites that affect cellular homeostasis, as well as other processes such as cell death and inflammation. Thus, mitochondrial function and dysfunction are central to the health and fate of the cell. Consequently, there is considerable interest in better understanding and assessing the many roles of mitochondria. Furthermore, there is also a growing realization that mitochondrial are a promising drug target in a wide range of pathologies. The application of interdisciplinary approaches at the interface between chemistry and biology are opening up new opportunities to understand mitochondrial function and in assessing the role of the organelle in biology. This work and the experience thus gained are leading to the development of new classes of therapies. Here, we overview the progress that has been made to date on exploring the chemical biology of the organelle and then focus on future challenges and opportunities that face this rapidly developing field.
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Affiliation(s)
- Angela Logan
- MRC Mitochondrial Biology Unit , Hills Road, Cambridge CB2 0XY , UK
| | - Michael P Murphy
- MRC Mitochondrial Biology Unit , Hills Road, Cambridge CB2 0XY , UK
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22
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Yang T, Moreira W, Nyantakyi SA, Chen H, Aziz DB, Go ML, Dick T. Amphiphilic Indole Derivatives as Antimycobacterial Agents: Structure–Activity Relationships and Membrane Targeting Properties. J Med Chem 2017; 60:2745-2763. [DOI: 10.1021/acs.jmedchem.6b01530] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Tianming Yang
- Department
of Pharmacy and ‡Department of Microbiology and Immunology, National University of Singapore, Singapore 117543, Singapore
| | - Wilfried Moreira
- Department
of Pharmacy and ‡Department of Microbiology and Immunology, National University of Singapore, Singapore 117543, Singapore
| | - Samuel Agyei Nyantakyi
- Department
of Pharmacy and ‡Department of Microbiology and Immunology, National University of Singapore, Singapore 117543, Singapore
| | - Huan Chen
- Department
of Pharmacy and ‡Department of Microbiology and Immunology, National University of Singapore, Singapore 117543, Singapore
| | - Dinah binte Aziz
- Department
of Pharmacy and ‡Department of Microbiology and Immunology, National University of Singapore, Singapore 117543, Singapore
| | - Mei-Lin Go
- Department
of Pharmacy and ‡Department of Microbiology and Immunology, National University of Singapore, Singapore 117543, Singapore
| | - Thomas Dick
- Department
of Pharmacy and ‡Department of Microbiology and Immunology, National University of Singapore, Singapore 117543, Singapore
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23
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The mechanism of catalysis by type-II NADH:quinone oxidoreductases. Sci Rep 2017; 7:40165. [PMID: 28067272 PMCID: PMC5220320 DOI: 10.1038/srep40165] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Accepted: 12/01/2016] [Indexed: 11/08/2022] Open
Abstract
Type II NADH:quinone oxidoreductase (NDH-2) is central to the respiratory chains of many organisms. It is not present in mammals so may be exploited as an antimicrobial drug target or used as a substitute for dysfunctional respiratory complex I in neuromuscular disorders. NDH-2 is a single-subunit monotopic membrane protein with just a flavin cofactor, yet no consensus exists on its mechanism. Here, we use steady-state and pre-steady-state kinetics combined with mutagenesis and structural studies to determine the mechanism of NDH-2 from Caldalkalibacillus thermarum. We show that the two substrate reactions occur independently, at different sites, and regardless of the occupancy of the partner site. We conclude that the reaction pathway is determined stochastically, by the substrate/product concentrations and dissociation constants, and can follow either a ping-pong or ternary mechanism. This mechanistic versatility provides a unified explanation for all extant data and a new foundation for the development of therapeutic strategies.
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24
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Kavianinia I, Kunalingam L, Harris PWR, Cook GM, Brimble MA. Total Synthesis and Stereochemical Revision of the Anti-Tuberculosis Peptaibol Trichoderin A. Org Lett 2016; 18:3878-81. [DOI: 10.1021/acs.orglett.6b01886] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Iman Kavianinia
- School
of Biological Sciences, The University of Auckland, 3A Symonds
Street, Auckland 1010, New Zealand
- Maurice
Wilkins Centre for Molecular Biodiscovery, The University of Auckland, 3A Symonds Street, Auckland 1010, New Zealand
| | - Lavanya Kunalingam
- School
of Biological Sciences, The University of Auckland, 3A Symonds
Street, Auckland 1010, New Zealand
| | - Paul W. R. Harris
- School
of Biological Sciences, The University of Auckland, 3A Symonds
Street, Auckland 1010, New Zealand
- Maurice
Wilkins Centre for Molecular Biodiscovery, The University of Auckland, 3A Symonds Street, Auckland 1010, New Zealand
| | - Gregory M. Cook
- Maurice
Wilkins Centre for Molecular Biodiscovery, The University of Auckland, 3A Symonds Street, Auckland 1010, New Zealand
- Department
of Microbiology and Immunology, School of Medical Sciences, University of Otago, 720 Cumberland Street, Dunedin 9054, New Zealand
| | - Margaret A. Brimble
- School
of Biological Sciences, The University of Auckland, 3A Symonds
Street, Auckland 1010, New Zealand
- Maurice
Wilkins Centre for Molecular Biodiscovery, The University of Auckland, 3A Symonds Street, Auckland 1010, New Zealand
- School
of Chemical Sciences, The University of Auckland, 23 Symonds
Street, Auckland 1010, New Zealand
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25
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Trush MM, Kovalishyn VV, Blagodatnyi VM, Brovarets VS, Pilyo SG, Prokopenko VM, Hodyna DM, Metelytsia LO. QSAR studies and antimicrobial potential of 1,3-thiazolylphosphonium salts. UKRAINIAN BIOCHEMICAL JOURNAL 2016; 88:57-65. [PMID: 29235765 DOI: 10.15407/ubj88.04.057] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The regression QSAR models were built to predict the antimicrobial activity of new thiazole derivatives. Compounds with high predicting activity were synthesized and evaluated against Gram-positive and Gram-negative bacteria and fungi. 1,3-Thiazole-4-ylphosphonium salts 4 and 5 displayed good antibacterial properties and high antifungal activity. The predictions are in a good agreement with the experiment results, which indicate the good predictive power of the created QSAR models.
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26
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Heikal A, Hards K, Cheung CY, Menorca A, Timmer MSM, Stocker BL, Cook GM. Activation of type II NADH dehydrogenase by quinolinequinones mediates antitubercular cell death. J Antimicrob Chemother 2016; 71:2840-7. [DOI: 10.1093/jac/dkw244] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Accepted: 05/19/2016] [Indexed: 12/31/2022] Open
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