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Arakal BS, Rowlands RS, Maddocks SE, Whitworth DE, James PE, Livingstone PG. Myxobacteria from soil can substantially reduce the bacterial load in a wound infection model. J Appl Microbiol 2025; 136:lxae315. [PMID: 39730144 DOI: 10.1093/jambio/lxae315] [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: 06/28/2024] [Revised: 11/20/2024] [Accepted: 12/26/2024] [Indexed: 12/29/2024]
Abstract
AIMS Myxobacteria are non-pathogenic, saprophytic, soil-dwelling predatory bacteria known for their antimicrobial potential. Many pathogenic bacteria form biofilms to protect themselves from antimicrobial agents and the immune system. This study has investigated the predatory activities of myxobacteria against pathogenic bacteria in biofilms. METHODS AND RESULTS A total of 50 soil samples were collected in and around Cardiff, South Wales (UK). Using a baiting method with 6 prey organisms, 32 myxobacteria were isolated and identified by 16S rRNA sequencing, of which 18 were Myxococcus spp. and 14 were Corallococcus spp. Predation assays, biofilm inhibition and disruption assays, and a dynamic, polymicrobial wound biofilm model were used with live myxobacteria to assess efficacy of predation. Good activity in predation assays was observed against Escherichia coli, while Enterococcus faecalis was more recalcitrant to myxobacteria. Staphylococcus aureus and Citrobacter freundii were significantly (P < 0.05) reduced in both biofilm inhibition and disruption assays compared to other pathogens. Considerable reductions (>3 log10 CFU) in the wound infection model were seen after 96 h of incubation, particularly for C. freundii and E. coli. CONCLUSION Using live predatory bacteria as an alternative therapeutic agent has received attention in the recent past to combat the problem of antimicrobial resistance. Myxobacteria isolated from soil using multiple prey organisms yielded diverse isolates, including strains which exhibited therapeutically promising activities in a variety of infection/biofilm assays.
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Affiliation(s)
- Benita S Arakal
- School of Sports and Health Sciences, Cardiff Metropolitan University, Llandaff campus, Cardiff CF5 2YB, United Kingdom
| | - Richard S Rowlands
- School of Sports and Health Sciences, Cardiff Metropolitan University, Llandaff campus, Cardiff CF5 2YB, United Kingdom
| | - Sarah E Maddocks
- School of Sports and Health Sciences, Cardiff Metropolitan University, Llandaff campus, Cardiff CF5 2YB, United Kingdom
| | - David E Whitworth
- Department of Life Sciences, Aberystwyth University, Aberystwyth SY23 3FL, United Kingdom
| | - Philip E James
- School of Sports and Health Sciences, Cardiff Metropolitan University, Llandaff campus, Cardiff CF5 2YB, United Kingdom
| | - Paul G Livingstone
- School of Sports and Health Sciences, Cardiff Metropolitan University, Llandaff campus, Cardiff CF5 2YB, United Kingdom
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2
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Scharnow A, Solinski AE, Rowe S, Drechsel I, Zhang H, Shaw E, Page JE, Wu H, Sieber SA, Wuest WM. In Situ Biofilm Affinity-Based Protein Profiling Identifies the Streptococcal Hydrolase GbpB as the Target of a Carolacton-Inspired Chemical Probe. J Am Chem Soc 2024; 146:23449-23456. [PMID: 39133525 PMCID: PMC11345752 DOI: 10.1021/jacs.4c06658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2024] [Revised: 08/01/2024] [Accepted: 08/01/2024] [Indexed: 08/13/2024]
Abstract
Natural products are important precursors for antibiotic drug design. These chemical scaffolds serve as synthetic inspiration for chemists who leverage their structures to develop novel antibacterials and chemical probes. We have previously studied carolacton, a natural product macrolactone fromSorangium cellulosum, and discovered a simplified derivative, A2, that maintained apparent biofilm inhibitory activity, although the biological target was unknown. Herein, we utilize affinity-based protein profiling (AfBPP) in situ during biofilm formation to identify the protein target using a photoexcitable cross-linking derivative of A2. From these studies, we identified glucan binding protein B (GbpB), a peptidoglycan hydrolase, as the primary target of A2. Further characterization of the interaction between A2 and GbpB, as well as PcsB, a closely related homologue from the more pathogenic S. pneumoniae, revealed binding to the catalytic CHAP (cysteine, histidine, aminopeptidase) domain. To the best of our knowledge, this is the first report of a small-molecule binder of a conserved and essential bacterial CHAP hydrolase, revealing its potential as an antibiotic target. This work also highlights A2 as a useful tool compound for streptococci and as an initial scaffold for the design of more potent CHAP binders.
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Affiliation(s)
- Amber
M. Scharnow
- Department
of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Amy E. Solinski
- Department
of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Sebastian Rowe
- Department
of Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Ines Drechsel
- Department
of Chemistry, Center for Functional Protein Assemblies, Technical University of Munich, Garching D-85747, Germany
| | - Hua Zhang
- Departments
of Pediatric Dentistry, Microbiology, Schools of Dentistry and Medicine, University of Alabama at Birmingham, Birmingham 35294, Alabama, United States
| | - Elana Shaw
- Department
of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Julia E. Page
- Department
of Microbiology, Blavatnik Institute, Harvard
Medical School, Boston, Massachusetts 02115, United States
| | - Hui Wu
- Departments
of Pediatric Dentistry, Microbiology, Schools of Dentistry and Medicine, University of Alabama at Birmingham, Birmingham 35294, Alabama, United States
| | - Stephan A. Sieber
- Department
of Chemistry, Center for Functional Protein Assemblies, Technical University of Munich, Garching D-85747, Germany
| | - William M. Wuest
- Department
of Chemistry, Emory University, Atlanta, Georgia 30322, United States
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3
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Shagufta, Ahmad I. An Update on Pharmacological Relevance and Chemical Synthesis of Natural Products and Derivatives with Anti SARS-CoV-2 Activity. ChemistrySelect 2021; 6:11502-11527. [PMID: 34909460 PMCID: PMC8661826 DOI: 10.1002/slct.202103301] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Accepted: 10/25/2021] [Indexed: 01/18/2023]
Abstract
Natural products recognized traditionally as a vital source of active constituents in pharmacotherapy. The COVID-19 infection caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is highly transmissible, pathogenic, and considered an ongoing global health emergency. The emergence of COVID-19 globally and the lack of adequate treatment brought attention towards herbal medicines, and scientists across the globe instigated the search for novel drugs from medicinal plants and natural products to tackle this deadly virus. The natural products rich in scaffold diversity and structural complexity are an excellent source for antiviral drug discovery. Recently the investigation of several natural products and their synthetic derivatives resulted in the identification of promising anti SARS-CoV-2 agents. This review article will highlight the pharmacological relevance and chemical synthesis of the recently discovered natural product and their synthetic analogs as SARS-CoV-2 inhibitors. The summarized information will pave the path for the natural product-based drug discovery of safe and potent antiviral agents, particularly against SARS-CoV-2.
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Affiliation(s)
- Shagufta
- Department of Mathematics and Natural SciencesSchool of Arts and SciencesAmerican University of Ras Al KhaimahRas Al Khaimah Road, P. O. Box10021Ras Al Khaimah, UAE
| | - Irshad Ahmad
- Department of Mathematics and Natural SciencesSchool of Arts and SciencesAmerican University of Ras Al KhaimahRas Al Khaimah Road, P. O. Box10021Ras Al Khaimah, UAE
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4
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Cataldo PG, Klemm P, Thüring M, Saavedra L, Hebert EM, Hartmann RK, Lechner M. Insights into 6S RNA in lactic acid bacteria (LAB). BMC Genom Data 2021; 22:29. [PMID: 34479493 PMCID: PMC8414754 DOI: 10.1186/s12863-021-00983-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 08/12/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND 6S RNA is a regulator of cellular transcription that tunes the metabolism of cells. This small non-coding RNA is found in nearly all bacteria and among the most abundant transcripts. Lactic acid bacteria (LAB) constitute a group of microorganisms with strong biotechnological relevance, often exploited as starter cultures for industrial products through fermentation. Some strains are used as probiotics while others represent potential pathogens. Occasional reports of 6S RNA within this group already indicate striking metabolic implications. A conceivable idea is that LAB with 6S RNA defects may metabolize nutrients faster, as inferred from studies of Echerichia coli. This may accelerate fermentation processes with the potential to reduce production costs. Similarly, elevated levels of secondary metabolites might be produced. Evidence for this possibility comes from preliminary findings regarding the production of surfactin in Bacillus subtilis, which has functions similar to those of bacteriocins. The prerequisite for its potential biotechnological utility is a general characterization of 6S RNA in LAB. RESULTS We provide a genomic annotation of 6S RNA throughout the Lactobacillales order. It laid the foundation for a bioinformatic characterization of common 6S RNA features. This covers secondary structures, synteny, phylogeny, and product RNA start sites. The canonical 6S RNA structure is formed by a central bulge flanked by helical arms and a template site for product RNA synthesis. 6S RNA exhibits strong syntenic conservation. It is usually flanked by the replication-associated recombination protein A and the universal stress protein A. A catabolite responsive element was identified in over a third of all 6S RNA genes. It is known to modulate gene expression based on the available carbon sources. The presence of antisense transcripts could not be verified as a general trait of LAB 6S RNAs. CONCLUSIONS Despite a large number of species and the heterogeneity of LAB, the stress regulator 6S RNA is well-conserved both from a structural as well as a syntenic perspective. This is the first approach to describe 6S RNAs and short 6S RNA-derived transcripts beyond a single species, spanning a large taxonomic group covering multiple families. It yields universal insights into this regulator and complements the findings derived from other bacterial model organisms.
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Affiliation(s)
- Pablo Gabriel Cataldo
- Centro de Referencia para Lactobacilos (CERELA-CONICET), Chacabuco 145, San Miguel de Tucumán, 4000, Argentina
| | - Paul Klemm
- Philipps-Universität Marburg, Institut für Pharmazeutische Chemie, Marbacher Weg 6, Marburg, 35032, Germany
| | - Marietta Thüring
- Philipps-Universität Marburg, Institut für Pharmazeutische Chemie, Marbacher Weg 6, Marburg, 35032, Germany
| | - Lucila Saavedra
- Centro de Referencia para Lactobacilos (CERELA-CONICET), Chacabuco 145, San Miguel de Tucumán, 4000, Argentina
| | - Elvira Maria Hebert
- Centro de Referencia para Lactobacilos (CERELA-CONICET), Chacabuco 145, San Miguel de Tucumán, 4000, Argentina
| | - Roland K Hartmann
- Philipps-Universität Marburg, Institut für Pharmazeutische Chemie, Marbacher Weg 6, Marburg, 35032, Germany
| | - Marcus Lechner
- Philipps-Universität Marburg, Institut für Pharmazeutische Chemie, Marbacher Weg 6, Marburg, 35032, Germany. .,Philipps-Universität Marburg, Center for Synthetic Microbiology (Synmikro), Hans-Meerwein-Straße 6, Marburg, 35043, Germany.
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5
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Wang QQ, Li MX, Li C, Gu XX, Zheng MZ, Chen LX, Li H. Natural Products and Derivatives Targeting at Cancer Energy Metabolism: A Potential Treatment Strategy. Curr Med Sci 2020; 40:205-217. [PMID: 32337682 DOI: 10.1007/s11596-020-2165-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2020] [Revised: 03/14/2020] [Indexed: 12/13/2022]
Abstract
In the 1920s, Dr Otto Warburg first suggested the significant difference in energy metabolism between malignant cancer cells and adjacent normal cells. Tumor cells mainly adopt the glycolysis as energy source to maintain tumor cell growth and biosynthesis under aerobic conditions. Investigation on energy metabolism pathway in cancer cells has aroused the interest of cancer researchers all around the world. In recent years, plentiful studies suggest that targeting the peculiar cancer energy metabolic pathways, including glycolysis, mitochondrial respiration, amino acid metabolism, and fatty acid oxidation may be an effective strategy to starve cancer cells by blocking essential nutrients. Natural products (NPs) are considered as the "treasure trove of small molecules drugs" and have played an extremely remarkable role in the discovery and development of anticancer drugs. And numerous NPs have been reported to act on cancer energy metabolism targets. Herein, a comprehensive overview about cancer energy metabolism targets and their natural-occurring inhibitors is prepared.
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Affiliation(s)
- Qi-Qi Wang
- Wuya College of Innovation, School of Pharmaceutical Engineering, Key Laboratory of Structure-Based Drug Design & Discovery, Ministry of Education, Shenyang Pharmaceutical University, Shenyang, 110016, China
| | - Ming-Xue Li
- Wuya College of Innovation, School of Pharmaceutical Engineering, Key Laboratory of Structure-Based Drug Design & Discovery, Ministry of Education, Shenyang Pharmaceutical University, Shenyang, 110016, China
| | - Chen Li
- Wuya College of Innovation, School of Pharmaceutical Engineering, Key Laboratory of Structure-Based Drug Design & Discovery, Ministry of Education, Shenyang Pharmaceutical University, Shenyang, 110016, China
| | - Xiao-Xia Gu
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Meng-Zhu Zheng
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
| | - Li-Xia Chen
- Wuya College of Innovation, School of Pharmaceutical Engineering, Key Laboratory of Structure-Based Drug Design & Discovery, Ministry of Education, Shenyang Pharmaceutical University, Shenyang, 110016, China.
| | - Hua Li
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
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6
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Conrads G, Wendt LK, Hetrodt F, Deng ZL, Pieper D, Abdelbary MMH, Barg A, Wagner-Döbler I, Apel C. Deep sequencing of biofilm microbiomes on dental composite materials. J Oral Microbiol 2019; 11:1617013. [PMID: 31143408 PMCID: PMC6522937 DOI: 10.1080/20002297.2019.1617013] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Revised: 04/16/2019] [Accepted: 05/06/2019] [Indexed: 12/31/2022] Open
Abstract
Background: The microbiome on dental composites has not been studied in detail before. It has not been conclusively clarified whether restorative materials influence the oral microbiome. Methods: We used Illumina Miseq next-generation sequencing of the 16S V1-V2 region to compare the colonisation patterns of bovine enamel (BE) and the composite materials Grandio Flow (GF) and Grandio Blocs (GB) after 48 h in vivo in 14 volunteers. Applying a new method to maintain the oral microbiome ex vivo for 48 h also, we compared the microbiome on GF alone and with the new antimicrobial substance carolacton (GF+C). Results: All in vitro biofilm communities showed a higher diversity and richness than those grown in vivo but the very different atmospheric conditions must be considered. Contrary to expectations, there were only a few significant differences between BE and the composite materials GB and GF either in vivo or in vitro: Oribacterium, Peptostreptococcaceae [XI][G-1] and Streptococcus mutans were more prevalent and Megasphaera, Prevotella oulorum, Veillonella atypica, V. parvula, Gemella morbillorum, and Fusobacterium periodonticum were less prevalent on BE than on composites. In vivo, such preferences were only significant for Granulicatella adiacens (more prevalent on BE) and Fusobacterium nucleatum subsp. animalis (more prevalent on composites). On DNA sequence level, there were no significant differences between the biofilm communities on GF and GF+C. Conclusion: We found that the oral microbiome showed an increased richness when grown on various composites compared to BE in vitro, but otherwise changed only slightly independent of the in vivo or in vitro condition. Our new ex vivo biofilm model might be useful for pre-clinical testing of preventive strategies.
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Affiliation(s)
- Georg Conrads
- Division of Oral Microbiology and Immunology, Department of Operative and Preventive Dentistry & Periodontology, RWTH Aachen University Hospital, Aachen, Germany
| | - Laura Katharina Wendt
- Division of Oral Microbiology and Immunology, Department of Operative and Preventive Dentistry & Periodontology, RWTH Aachen University Hospital, Aachen, Germany
| | - Franziska Hetrodt
- Division of Oral Microbiology and Immunology, Department of Operative and Preventive Dentistry & Periodontology, RWTH Aachen University Hospital, Aachen, Germany.,Department of Biohybrid & Medical Textiles, Institute of Applied Medical Engineering, RWTH Aachen University, Aachen, Germany
| | - Zhi-Luo Deng
- Group Microbial Communication, Helmholtz Center for Infection Research (HZI), Braunschweig, Germany
| | - Dietmar Pieper
- Group Microbial Interactions and Processes, Helmholtz Center for Infection Research (HZI), Braunschweig, Germany
| | - Mohamed M H Abdelbary
- Division of Oral Microbiology and Immunology, Department of Operative and Preventive Dentistry & Periodontology, RWTH Aachen University Hospital, Aachen, Germany
| | | | - Irene Wagner-Döbler
- Group Microbial Communication, Helmholtz Center for Infection Research (HZI), Braunschweig, Germany
| | - Christian Apel
- Department of Biohybrid & Medical Textiles, Institute of Applied Medical Engineering, RWTH Aachen University, Aachen, Germany
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7
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Leonard A, Lalk M. Infection and metabolism – Streptococcus pneumoniae metabolism facing the host environment. Cytokine 2018; 112:75-86. [DOI: 10.1016/j.cyto.2018.07.021] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 07/15/2018] [Accepted: 07/16/2018] [Indexed: 12/21/2022]
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8
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van Geelen L, Meier D, Rehberg N, Kalscheuer R. (Some) current concepts in antibacterial drug discovery. Appl Microbiol Biotechnol 2018; 102:2949-2963. [PMID: 29455386 DOI: 10.1007/s00253-018-8843-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 02/05/2018] [Accepted: 02/06/2018] [Indexed: 12/30/2022]
Abstract
The rise of multidrug resistance in bacteria rendering pathogens unresponsive to many clinical drugs is widely acknowledged and considered a critical global healthcare issue. There is broad consensus that novel antibacterial chemotherapeutic options are extremely urgently needed. However, the development pipeline of new antibacterial drug lead structures is poorly filled and not commensurate with the scale of the problem since the pharmaceutical industry has shown reduced interest in antibiotic development in the past decades due to high economic risks and low profit expectations. Therefore, academic research institutions have a special responsibility in finding novel treatment options for the future. In this mini review, we want to provide a broad overview of the different approaches and concepts that are currently pursued in this research field.
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Affiliation(s)
- Lasse van Geelen
- Institute of Pharmaceutical Biology and Biotechnology, Heinrich Heine University Düsseldorf, 40225, Dusseldorf, Germany
| | - Dieter Meier
- Institute of Pharmaceutical Biology and Biotechnology, Heinrich Heine University Düsseldorf, 40225, Dusseldorf, Germany
| | - Nidja Rehberg
- Institute of Pharmaceutical Biology and Biotechnology, Heinrich Heine University Düsseldorf, 40225, Dusseldorf, Germany
| | - Rainer Kalscheuer
- Institute of Pharmaceutical Biology and Biotechnology, Heinrich Heine University Düsseldorf, 40225, Dusseldorf, Germany.
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9
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Solinski AE, Ochoa C, Lee YE, Paniak T, Kozlowski MC, Wuest WM. Honokiol-Inspired Analogs as Inhibitors of Oral Bacteria. ACS Infect Dis 2018; 4:118-122. [PMID: 29236466 PMCID: PMC5869685 DOI: 10.1021/acsinfecdis.7b00178] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The oral microbiome is a complex ecological niche where both commensal and pathogenic bacteria coexist. Previous reports have cited that the plant isolate honokiol is a potent inhibitor of S. mutans biofilms. Herein we report a cross-coupling method that provides access to a concise library of honokiol-inspired analogs. Through this work we determined that the inhibitory activity of honokiol is highly dependent on the growth conditions. Further, we identify a series of analogs that display significant potency against oral bacteria leading to the discovery of a potent antimicrobial.
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Affiliation(s)
- Amy E. Solinski
- Department of Chemistry, 1515 Dickey Drive, Emory University, Atlanta, Georgia 30322, United States
| | - Cristian Ochoa
- Department of Chemistry, Roy and Diana Vagelos Laboratories, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Young Eun Lee
- Department of Chemistry, Roy and Diana Vagelos Laboratories, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Thomas Paniak
- Department of Chemistry, Roy and Diana Vagelos Laboratories, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Marisa C. Kozlowski
- Department of Chemistry, Roy and Diana Vagelos Laboratories, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - William M. Wuest
- Department of Chemistry, 1515 Dickey Drive, Emory University, Atlanta, Georgia 30322, United States
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10
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The natural product carolacton inhibits folate-dependent C1 metabolism by targeting FolD/MTHFD. Nat Commun 2017; 8:1529. [PMID: 29142318 PMCID: PMC5688156 DOI: 10.1038/s41467-017-01671-5] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Accepted: 10/05/2017] [Indexed: 01/26/2023] Open
Abstract
The natural product carolacton is a macrolide keto-carboxylic acid produced by the myxobacterium Sorangium cellulosum, and was originally described as an antibacterial compound. Here we show that carolacton targets FolD, a key enzyme from the folate-dependent C1 metabolism. We characterize the interaction between bacterial FolD and carolacton biophysically, structurally and biochemically. Carolacton binds FolD with nanomolar affinity, and the crystal structure of the FolD–carolacton complex reveals the mode of binding. We show that the human FolD orthologs, MTHFD1 and MTHFD2, are also inhibited in the low nM range, and that micromolar concentrations of carolacton inhibit the growth of cancer cell lines. As mitochondrial MTHFD2 is known to be upregulated in cancer cells, it may be possible to use carolacton as an inhibitor tool compound to assess MTHFD2 as an anti-cancer target. The mechanisms behind the antibacterial activity of the natural product carolacton are unknown. Here, the authors show that carolacton is a potent inhibitor of FolD/MTHFD enzymes (involved in folate-dependent C1 metabolism in bacteria and humans) and inhibits the growth of cancer cell lines
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11
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Selwood DL. Macrocycles, the edge of drug-likeness chemical space or Goldilocks zone? Chem Biol Drug Des 2017; 89:164-168. [PMID: 28205398 DOI: 10.1111/cbdd.12922] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2016] [Accepted: 12/24/2016] [Indexed: 11/29/2022]
Affiliation(s)
- David L Selwood
- The Wolfson Institute for Biomedical Research, University College London, London, UK
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12
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Abstract
Natural products have served as powerful therapeutics against pathogenic bacteria since the golden age of antibiotics of the mid-20th century. However, the increasing frequency of antibiotic-resistant infections clearly demonstrates that new antibiotics are critical for modern medicine. Because combinatorial approaches have not yielded effective drugs, we propose that the development of new antibiotics around proven natural scaffolds is the best short-term solution to the rising crisis of antibiotic resistance. We analyze herein synthetic approaches aiming to reengineer natural products into potent antibiotics. Furthermore, we discuss approaches in modulating quorum sensing and biofilm formation as a nonlethal method, as well as narrow-spectrum pathogen-specific antibiotics, which are of interest given new insights into the implications of disrupting the microbiome.
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Affiliation(s)
- Sean E. Rossiter
- Department of Chemistry, Emory University, 1515 Dickey Drive, Atlanta, Georgia 30322, United States
| | - Madison H. Fletcher
- Department of Chemistry, Temple University, 1901 North 13th Street, Philadelphia, Pennsylvania 19122, United States
| | - William M. Wuest
- Department of Chemistry, Emory University, 1515 Dickey Drive, Atlanta, Georgia 30322, United States
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13
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The Biofilm Inhibitor Carolacton Enters Gram-Negative Cells: Studies Using a TolC-Deficient Strain of Escherichia coli. mSphere 2017; 2:mSphere00375-17. [PMID: 28959742 PMCID: PMC5615136 DOI: 10.1128/mspheredirect.00375-17] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 08/26/2017] [Indexed: 12/18/2022] Open
Abstract
The emergence of pathogens resistant against most or all of the antibiotics currently used in human therapy is a global threat, and therefore the search for antimicrobials with novel targets and modes of action is of utmost importance. The myxobacterial secondary metabolite carolacton had previously been shown to inhibit biofilm formation and growth of streptococci. Here, we investigated if carolacton could act against Gram-negative bacteria, which are difficult targets because of their double-layered cytoplasmic envelope. We found that the model organism Escherichia coli is susceptible to carolacton, similar to the Gram-positive Streptococcus pneumoniae, if its multidrug efflux system AcrAB-TolC is either inactivated genetically, by disruption of the tolC gene, or physiologically by coadministering an efflux pump inhibitor. A carolacton epimer that has a different steric configuration at carbon atom 9 is completely inactive, suggesting that carolacton may interact with the same molecular target in both Gram-positive and Gram-negative bacteria. The myxobacterial secondary metabolite carolacton inhibits growth of Streptococcus pneumoniae and kills biofilm cells of the caries- and endocarditis-associated pathogen Streptococcus mutans at nanomolar concentrations. Here, we studied the response to carolacton of an Escherichia coli strain that lacked the outer membrane protein TolC. Whole-genome sequencing of the laboratory E. coli strain TolC revealed the integration of an insertion element, IS5, at the tolC locus and a close phylogenetic relationship to the ancient E. coli K-12. We demonstrated via transcriptome sequencing (RNA-seq) and determination of MIC values that carolacton penetrates the phospholipid bilayer of the Gram-negative cell envelope and inhibits growth of E. coli TolC at similar concentrations as for streptococci. This inhibition is completely lost for a C-9 (R) epimer of carolacton, a derivative with an inverted stereocenter at carbon atom 9 [(S) → (R)] as the sole difference from the native molecule, which is also inactive in S. pneumoniae and S. mutans, suggesting a specific interaction of native carolacton with a conserved cellular target present in bacterial phyla as distantly related as Firmicutes and Proteobacteria. The efflux pump inhibitor (EPI) phenylalanine arginine β-naphthylamide (PAβN), which specifically inhibits AcrAB-TolC, renders E. coli susceptible to carolacton. Our data indicate that carolacton has potential for use in antimicrobial chemotherapy against Gram-negative bacteria, as a single drug or in combination with EPIs. Strain E. coli TolC has been deposited at the DSMZ; together with the associated RNA-seq data and MIC values, it can be used as a reference during future screenings for novel bioactive compounds. IMPORTANCE The emergence of pathogens resistant against most or all of the antibiotics currently used in human therapy is a global threat, and therefore the search for antimicrobials with novel targets and modes of action is of utmost importance. The myxobacterial secondary metabolite carolacton had previously been shown to inhibit biofilm formation and growth of streptococci. Here, we investigated if carolacton could act against Gram-negative bacteria, which are difficult targets because of their double-layered cytoplasmic envelope. We found that the model organism Escherichia coli is susceptible to carolacton, similar to the Gram-positive Streptococcus pneumoniae, if its multidrug efflux system AcrAB-TolC is either inactivated genetically, by disruption of the tolC gene, or physiologically by coadministering an efflux pump inhibitor. A carolacton epimer that has a different steric configuration at carbon atom 9 is completely inactive, suggesting that carolacton may interact with the same molecular target in both Gram-positive and Gram-negative bacteria.
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14
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Abstract
A short and convergent strategy for the stereoselective total synthesis of biologically active natural product carolacton has been accomplished. Our synthesis highlights the Urpi acetal aldol, Crimmins aldol, Ireland-Claisen rearrangement, TiCl4-assisted aldol followed by β-hydroxy elimination to construct C7-C8 olefin, and ring-closing metathesis as the key steps for achieving the target molecule with an overall yield of 18.8%.
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Affiliation(s)
- Tapan Kumar Kuilya
- Department of Organic Chemistry, Indian Association for the Cultivation of Science , Jadavpur, Kolkata 700032, India
| | - Rajib Kumar Goswami
- Department of Organic Chemistry, Indian Association for the Cultivation of Science , Jadavpur, Kolkata 700032, India
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15
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Complete Genome Sequences of Three Multidrug-Resistant Clinical Isolates of Streptococcus pneumoniae Serotype 19A with Different Susceptibilities to the Myxobacterial Metabolite Carolacton. GENOME ANNOUNCEMENTS 2017; 5:5/7/e01641-16. [PMID: 28209832 PMCID: PMC5313624 DOI: 10.1128/genomea.01641-16] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The full-genome sequences of three drug- and multidrug-resistant Streptococcus pneumoniae clinical isolates of serotype 19A were determined by PacBio single-molecule real-time sequencing, in combination with Illumina MiSeq sequencing. A comparison to the genomes of other pneumococci indicates a high nucleotide sequence identity to strains Hungary19A-6 and TCH8431/19A.
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16
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Ammermann J, Schmidt T, Donner J, Reck M, Dalton M, Stumpp N, Stiesch M, Wagner-Döbler I, Kirschning A. The carolactam strategy is ineffective: synthesis and biological evaluation of carolactam. Org Biomol Chem 2017; 15:8553-8558. [DOI: 10.1039/c7ob02060k] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The lactam analogue of carolacton was prepared which has lost biofilm inhibitory activity towards Streptococcus mutans.
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Affiliation(s)
- Jonas Ammermann
- Institute of Organic Chemistry and Center of Biomolecular Drug Research (BMWZ)
- Leibniz Universität Hannover
- 30167 Hannover
- Germany
| | - Thomas Schmidt
- Institute of Organic Chemistry and Center of Biomolecular Drug Research (BMWZ)
- Leibniz Universität Hannover
- 30167 Hannover
- Germany
| | - Jannik Donner
- Helmholtz-Center for Infection Research
- Department of Microbial Communication
- 38124 Braunschweig
- Germany
| | - Michael Reck
- Helmholtz-Center for Infection Research
- Department of Microbial Communication
- 38124 Braunschweig
- Germany
| | - Marly Dalton
- Department of Prosthetic Dentistry and Biomedical Materials Science
- Hannover Medical School
- 30625 Hannover
- Germany
| | - Nico Stumpp
- Department of Prosthetic Dentistry and Biomedical Materials Science
- Hannover Medical School
- 30625 Hannover
- Germany
| | - Meike Stiesch
- Department of Prosthetic Dentistry and Biomedical Materials Science
- Hannover Medical School
- 30625 Hannover
- Germany
| | - Irene Wagner-Döbler
- Helmholtz-Center for Infection Research
- Department of Microbial Communication
- 38124 Braunschweig
- Germany
| | - Andreas Kirschning
- Institute of Organic Chemistry and Center of Biomolecular Drug Research (BMWZ)
- Leibniz Universität Hannover
- 30167 Hannover
- Germany
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17
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Herrmann J, Fayad AA, Müller R. Natural products from myxobacteria: novel metabolites and bioactivities. Nat Prod Rep 2016; 34:135-160. [PMID: 27907217 DOI: 10.1039/c6np00106h] [Citation(s) in RCA: 163] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Covering: 2011-July 2016Myxobacteria are a rich source for structurally diverse secondary metabolites with intriguing biological activities. Here we report on new natural products that were isolated from myxobacteria in the period of 2011 to July 2016. Some examples of recent advances on modes-of-action are also summarised along with a more detailed overview on five compound classes currently assessed in preclinical studies.
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Affiliation(s)
- J Herrmann
- Helmholtz Institute for Pharmaceutical Research Saarland, Department of Microbial Natural Products, Helmholtz Centre for Infection Research and Department of Pharmaceutical Biotechnology, Saarland University, Campus E8.1, 66123 Saarbrücken, Germany.
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