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Zhuo JR, Zhao JQ, Yang L, Wu YL, Zhang YP, You Y, Wang ZH, Zhou MQ, Yuan WC. Thiol-Triggered Tandem Dearomative Michael Addition/Intramolecular Henry Reaction of 2-Nitrobenzofurans: Access to Sulfur-Containing Polyheterocyclic Compounds. Org Lett 2024; 26:2623-2628. [PMID: 38522081 DOI: 10.1021/acs.orglett.4c00646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/26/2024]
Abstract
An efficient dearomative cyclization of 2-nitrobenzofurans via a thiol-triggered tandem Michael addition/intramolecular Henry reaction has been developed. A range of thiochromeno[3,2-b]benzofuran-11-ols and tetrahydrothieno[3,2-b]benzofuran-3-ols could be obtained in up to 99% yield and up to >20:1 dr. The valuable thiochromone fused benzofurans could be prepared with the reaction of 2-nitrobenzofurans and 2-mercaptobenzaldehyde via the tandem dearomative Michael addition/intramolecular Henry reaction/rearomatization/oxidative dehydrogenation process in a one-pot two-step operation. A mechanism for the reaction was tentatively proposed.
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Affiliation(s)
- Jun-Rui Zhuo
- Innovation Research Center of Chiral Drugs, Institute for Advanced Study, Chengdu University, Chengdu 610106, China
- Zunyi Medical and Pharmaceutical College, Zunyi 563006, China
| | - Jian-Qiang Zhao
- Innovation Research Center of Chiral Drugs, Institute for Advanced Study, Chengdu University, Chengdu 610106, China
| | - Lei Yang
- Innovation Research Center of Chiral Drugs, Institute for Advanced Study, Chengdu University, Chengdu 610106, China
| | - Yu-Lu Wu
- Innovation Research Center of Chiral Drugs, Institute for Advanced Study, Chengdu University, Chengdu 610106, China
| | - Yan-Ping Zhang
- Innovation Research Center of Chiral Drugs, Institute for Advanced Study, Chengdu University, Chengdu 610106, China
| | - Yong You
- Innovation Research Center of Chiral Drugs, Institute for Advanced Study, Chengdu University, Chengdu 610106, China
| | - Zhen-Hua Wang
- Innovation Research Center of Chiral Drugs, Institute for Advanced Study, Chengdu University, Chengdu 610106, China
| | - Ming-Qiang Zhou
- Innovation Research Center of Chiral Drugs, Institute for Advanced Study, Chengdu University, Chengdu 610106, China
- National Engineering Research Center of Chiral Drugs, Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wei-Cheng Yuan
- Innovation Research Center of Chiral Drugs, Institute for Advanced Study, Chengdu University, Chengdu 610106, China
- National Engineering Research Center of Chiral Drugs, Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041, China
- University of Chinese Academy of Sciences, Beijing 100049, China
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2
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Dehbashi S, Tahmasebi H, Alikhani MY, Vidal JE, Seifalian A, Arabestani MR. The healing effect of Pseudomonas Quinolone Signal (PQS) with co-infection of Staphylococcus aureus and Pseudomonas aeruginosa: A preclinical animal co-infection model. J Infect Public Health 2024; 17:329-338. [PMID: 38194764 DOI: 10.1016/j.jiph.2023.12.016] [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: 08/01/2023] [Revised: 12/09/2023] [Accepted: 12/18/2023] [Indexed: 01/11/2024] Open
Abstract
BACKGROUND Because of the rise in antibiotic resistance and the control of pathogenicity, polymicrobial bacterial biofilms exacerbate wound infections. Since bacterial quorum sensing (QS) signals can dysregulate biofilm development, they are interesting therapeutic treatments. In this study, Pseudomonas Quinolone Signal (PQS) was used to treat an animal model of a wound that had both Staphylococcus aureus and Pseudomonas aeruginosa co-infection. METHODS S. aureus and P. aeruginosa mono- and co-infection models were developed in vitro on the L-929 cell line and in an animal model of wound infection. Moreover, PQS was extracted and purified using liquid chromatography. Then, the mono- and co-infection models were treated by PQS in vitro and in vivo. RT-PCR analysis was used to look into changes in biofilm, QS, tissue regeneration, and apoptosis genes after the treatment. RESULTS PQS significantly disrupted established biofilm up to 90% in both in vitro and in vivo models. Moreover, a 93% reduction in the viability of S. aureus and P. aeruginosa was detected during the 10 days of treatment in comparison to control groups. In addition, the biofilm-encoding and QS-regulating genes were down-regulated to 75% in both microorganisms. Also, fewer epithelial cells died when treated with PQS compared to control groups in both mono- and co-infection groups. CONCLUSION According to this study, PQS may facilitate wound healing by stimulating the immune system and reducing apoptosis. It seems to be a potential medication to use in conjunction with antibiotics to treat infections that are difficult to treat.
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Affiliation(s)
- Sanaz Dehbashi
- Department of Laboratory Sciences, Varastegan Institute of Medical Sciences, Mashhad, Iran
| | - Hamed Tahmasebi
- School of Medicine, Shahroud University of Medical Sciences, Shahroud, Iran
| | - Mohammad Yousef Alikhani
- Department of Microbiology, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Jorge E Vidal
- Department of Cell and Molecular Biology, Center for Immunology and Microbial Research, University of Mississippi Medical Center, Jackson, MS 39216-4505, USA
| | - Alexander Seifalian
- Nanotechnology & Regenerative Medicine Commercialization Centre (NanoRegMed Ltd, Nanoloom Ltd, & Liberum Health Ltd), London BioScience Innovation Centre, London, United Kingdom
| | - Mohammad Reza Arabestani
- Department of Microbiology, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran; Infectious Disease Research center, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran.
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3
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Wu Y, Peng L, Feng P, Han R, Khan A, Kulshreshtha S, Ling Z, Liu P, Li X. Gut microbes consume host energy and reciprocally provide beneficial factors to sustain a symbiotic relationship with the host. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 904:166773. [PMID: 37689204 DOI: 10.1016/j.scitotenv.2023.166773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 08/30/2023] [Accepted: 08/31/2023] [Indexed: 09/11/2023]
Abstract
The gut microbes thrive by utilizing host energy and, in return, provide valuable benefits, akin to the symbiotic relationship. To study the mutualistic association between the gut microbiota and host, a range of gut microbe populations (85 %, 66 %, 45 % and 38 % at the normal level) with comparable structures were constructed in broiler model. The results revealed that reductions in gut microbial population led to decreased energy consumption, resulting in increased host weight (10.26 %, 30.88 %, 17.65 % and - 12.77 %, respectively). Fecal metabolome revealed that among 85 % and 66 % of the normal population level, the gut microbes downregulated the immune-associated pathways of tryptophan metabolism and catecholamine biosynthesis, while the level of fatty acid oxidation was upregulated at 45 %. In the host, the concentration of gut microbes contributed to regulate functions related to lipid biosynthesis (from glycerophosphoserines to glycerophosphoethanolamines (9.63 %, 12.20 %, 6.66 % and 47.75 %) and glycerophosphocholines (10.78 %, 36.51 %, 2.00 % and 87.11 %)) and inflammation responses (methionine and betaine metabolism). From 85 % to 45 % of gut microbes, broiler showed an inhibited immunity (thymus gland, spleen, SIgG and IgA) and increased low-level inflammation response (ALT and T-SOD). However, at 38 %, the immune indexes exhibited an increase (thymus gland, spleen, SIgG, and IgA increased by 8.67 %, 8.50 %, 20.87 %, and 29.43 %, respectively), indicating the host lipid accumulation and inflammation response were negatively correlated with the immune reaction. Collectively, the gut microbiota maintains a symbiotic relationship with the host through the secretion of beneficial substances to interact with the host.
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Affiliation(s)
- Ying Wu
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, Lanzhou, China; Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Science, Lanzhou University, Lanzhou, China
| | - Liang Peng
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, Lanzhou, China; Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Science, Lanzhou University, Lanzhou, China
| | - Pengya Feng
- Department of Children Rehabilitation Medicine, the Fifth Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China
| | - Rong Han
- College of Life Science and Technology, Gansu Agricultural University, Lanzhou, China
| | - Aman Khan
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, Lanzhou, China; Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Science, Lanzhou University, Lanzhou, China
| | - Sourabh Kulshreshtha
- School of Biotechnology, Faculty of Applied Sciences and Biotechnology, Shoolini University of Biotechnology and Management Sciences, Solan 173212, Himachal Pradesh, India
| | - Zhenmin Ling
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, Lanzhou, China; Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Science, Lanzhou University, Lanzhou, China
| | - Pu Liu
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, Lanzhou, China; Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Science, Lanzhou University, Lanzhou, China.
| | - Xiangkai Li
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, Lanzhou, China; Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Science, Lanzhou University, Lanzhou, China
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4
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Ückert AK, Rütschlin S, Gutbier S, Wörz NC, Miah MR, Martins AC, Hauer I, Holzer AK, Meyburg B, Mix AK, Hauck C, Aschner M, Böttcher T, Leist M. Identification of the bacterial metabolite aerugine as potential trigger of human dopaminergic neurodegeneration. ENVIRONMENT INTERNATIONAL 2023; 180:108229. [PMID: 37797477 PMCID: PMC10666548 DOI: 10.1016/j.envint.2023.108229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 09/14/2023] [Accepted: 09/22/2023] [Indexed: 10/07/2023]
Abstract
The causes of nigrostriatal cell death in idiopathic Parkinson's disease are unknown, but exposure to toxic chemicals may play some role. We followed up here on suggestions that bacterial secondary metabolites might be selectively cytotoxic to dopaminergic neurons. Extracts from Streptomyces venezuelae were found to kill human dopaminergic neurons (LUHMES cells). Utilizing this model system as a bioassay, we identified a bacterial metabolite known as aerugine (C10H11NO2S; 2-[4-(hydroxymethyl)-4,5-dihydro-1,3-thiazol-2-yl]phenol) and confirmed this finding by chemical re-synthesis. This 2-hydroxyphenyl-thiazoline compound was previously shown to be a product of a wide-spread biosynthetic cluster also found in the human microbiome and in several pathogens. Aerugine triggered half-maximal dopaminergic neurotoxicity at 3-4 µM. It was less toxic for other neurons (10-20 µM), and non-toxic (at <100 µM) for common human cell lines. Neurotoxicity was completely prevented by several iron chelators, by distinct anti-oxidants and by a caspase inhibitor. In the Caenorhabditis elegans model organism, general survival was not affected by aerugine concentrations up to 100 µM. When transgenic worms, expressing green fluorescent protein only in their dopamine neurons, were exposed to aerugine, specific neurodegeneration was observed. The toxicant also exerted functional dopaminergic toxicity in nematodes as determined by the "basal slowing response" assay. Thus, our research has unveiled a bacterial metabolite with a remarkably selective toxicity toward human dopaminergic neurons in vitro and for the dopaminergic nervous system of Caenorhabditis elegans in vivo. These findings suggest that microbe-derived environmental chemicals should be further investigated for their role in the pathogenesis of Parkinson's disease.
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Affiliation(s)
- Anna-Katharina Ückert
- In vitro Toxicology and Biomedicine, Dept inaugurated by the Doerenkamp-Zbinden foundation, University of Konstanz, 78457 Konstanz, Germany
| | - Sina Rütschlin
- Department of Chemistry, Konstanz Research School Chemical Biology, Zukunftskolleg, University of Konstanz, 78457 Konstanz, Germany
| | - Simon Gutbier
- In vitro Toxicology and Biomedicine, Dept inaugurated by the Doerenkamp-Zbinden foundation, University of Konstanz, 78457 Konstanz, Germany
| | - Nathalie Christine Wörz
- Faculty of Chemistry, Institute for Biological Chemistry & Centre for Microbiology and Environmental Systems Science, Department of Microbiology and Ecosystems Science, University of Vienna, Josef-Holaubek-Platz 2 (UZA II), 1090 Vienna, Austria; Doctoral School in Chemistry (DoSChem), University of Vienna, 1090 Vienna, Austria
| | - Mahfuzur R Miah
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, 10641 Bronx, NY, United States
| | - Airton C Martins
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, 10641 Bronx, NY, United States; Department of Neuroscience, Albert Einstein College of Medicine, 10641 Bronx, NY, United States
| | - Isa Hauer
- In vitro Toxicology and Biomedicine, Dept inaugurated by the Doerenkamp-Zbinden foundation, University of Konstanz, 78457 Konstanz, Germany
| | - Anna-Katharina Holzer
- In vitro Toxicology and Biomedicine, Dept inaugurated by the Doerenkamp-Zbinden foundation, University of Konstanz, 78457 Konstanz, Germany
| | - Birthe Meyburg
- In vitro Toxicology and Biomedicine, Dept inaugurated by the Doerenkamp-Zbinden foundation, University of Konstanz, 78457 Konstanz, Germany
| | - Ann-Kathrin Mix
- Lehrstuhl Zellbiologie, Universität Konstanz, Universitätsstraße 10, Postablage 621, 78457 Konstanz, Germany
| | - Christof Hauck
- Lehrstuhl Zellbiologie, Universität Konstanz, Universitätsstraße 10, Postablage 621, 78457 Konstanz, Germany
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, 10641 Bronx, NY, United States; Department of Neuroscience, Albert Einstein College of Medicine, 10641 Bronx, NY, United States
| | - Thomas Böttcher
- Department of Chemistry, Konstanz Research School Chemical Biology, Zukunftskolleg, University of Konstanz, 78457 Konstanz, Germany; Faculty of Chemistry, Institute for Biological Chemistry & Centre for Microbiology and Environmental Systems Science, Department of Microbiology and Ecosystems Science, University of Vienna, Josef-Holaubek-Platz 2 (UZA II), 1090 Vienna, Austria.
| | - Marcel Leist
- In vitro Toxicology and Biomedicine, Dept inaugurated by the Doerenkamp-Zbinden foundation, University of Konstanz, 78457 Konstanz, Germany
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5
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Hoshiko Y, Nishiyama Y, Moriya T, Kadokami K, López-Jácome LE, Hirano R, García-Contreras R, Maeda T. Quinolone Signals Related to Pseudomonas Quinolone Signal-Quorum Sensing Inhibits the Predatory Activity of Bdellovibrio bacteriovorus. Front Microbiol 2021; 12:722579. [PMID: 34566925 PMCID: PMC8461301 DOI: 10.3389/fmicb.2021.722579] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 08/12/2021] [Indexed: 12/12/2022] Open
Abstract
Bdellovibrio bacteriovorus is one of the predatory bacteria; therefore, it can act as a novel “living antibiotic,” unlike the current antibiotics. Here the predation of Escherichia coli by B. bacteriovorus was inhibited in the presence of Pseudomonas aeruginosa. This study investigated whether P. aeruginosa-induced predation inhibition is associated with bacterial quorum sensing (QS). Each las, rhl, or pqs QS mutant in P. aeruginosa was used to check the predatory activity of E. coli cells using B. bacteriovorus. As a result, the predatory activity of B. bacteriovorus increased in a mutant pqs QS system, whereas wild-type PA14 inhibited the predatory activity. Moreover, the addition of 4-hydroxy-2-heptylquinoline (HHQ) or the analog triggered the low predatory activity of B. bacteriovorus and killed B. bacteriovorus cells. Therefore, a defensive action of P. aeruginosa against B. bacteriovorus is activated by the pqs QS system, which produces some quinolone compounds such as HHQ.
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Affiliation(s)
- Yuki Hoshiko
- Department of Biological Functions Engineering, Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology, Kitakyushu, Japan
| | - Yoshito Nishiyama
- Department of Biological Functions Engineering, Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology, Kitakyushu, Japan
| | - Tae Moriya
- Department of Biological Functions Engineering, Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology, Kitakyushu, Japan
| | - Kiwao Kadokami
- Institute of Environmental Science and Technology, The University of Kitakyushu, Kitakyushu, Japan
| | - Luis Esaú López-Jácome
- Department of Microbiology and Parasitology, Faculty of Medicine, UNAM, Mexico City, Mexico.,Laboratory of Infectology, National Institute of Rehabilitation Luis Guillermo Ibarra Ibarra, Mexico City, Mexico
| | - Ryutaro Hirano
- Department of Biological Functions Engineering, Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology, Kitakyushu, Japan
| | | | - Toshinari Maeda
- Department of Biological Functions Engineering, Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology, Kitakyushu, Japan
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6
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In Lee J. Synthetic Approaches to
2‐Alkylthiochroman
‐4‐ones and Thioflavanones. B KOREAN CHEM SOC 2021. [DOI: 10.1002/bkcs.12272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Jae In Lee
- Department of Chemistry, College of Science and Technology Duksung Women's University Seoul 01369 Republic of Korea
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7
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Yang B, Fang D, Lv Q, Wang Z, Liu Y. Targeted Therapeutic Strategies in the Battle Against Pathogenic Bacteria. Front Pharmacol 2021; 12:673239. [PMID: 34054548 PMCID: PMC8149751 DOI: 10.3389/fphar.2021.673239] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Accepted: 04/23/2021] [Indexed: 12/14/2022] Open
Abstract
The emergence and rapid spread of antibiotic resistance in pathogenic bacteria constitute a global threat for public health. Despite ongoing efforts to confront this crisis, the pace of finding new potent antimicrobials is far slower than the evolution of drug resistance. The abuse of broad-spectrum antibiotics not only accelerates the formation of resistance but also imposes a burden on the intestinal microbiota, which acts a critical role in human homeostasis. As such, innovative therapeutic strategies with precision are pressingly warranted and highly anticipated. Recently, target therapies have achieved some breakthroughs by the aid of modern technology. In this review, we provide an insightful illustration of current and future medical targeted strategies, including narrow-spectrum agents, engineered probiotics, nanotechnology, phage therapy, and CRISPR-Cas9 technology. We discuss the recent advances and potential hurdles of these strategies. Meanwhile, the possibilities to mitigate the spread of resistance in these approaches are also mentioned. Altogether, a better understanding of the advantages, disadvantages, and mechanisms of action of these targeted therapies will be conducive to broadening our horizons and optimizing the existing antibacterial approaches.
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Affiliation(s)
- Bingqing Yang
- College of Veterinary Medicine, Yangzhou University, Yangzhou, China
| | - Dan Fang
- College of Veterinary Medicine, Yangzhou University, Yangzhou, China
| | - Qingyan Lv
- College of Veterinary Medicine, Yangzhou University, Yangzhou, China.,Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou, China.,Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, China
| | - Zhiqiang Wang
- College of Veterinary Medicine, Yangzhou University, Yangzhou, China.,Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou, China.,Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, China
| | - Yuan Liu
- College of Veterinary Medicine, Yangzhou University, Yangzhou, China.,Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou, China.,Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, China.,Institute of Comparative Medicine, Yangzhou University, Yangzhou, China
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8
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Sundaravelu N, Sekar G. Cu-Catalyzed one-pot synthesis of thiochromeno-quinolinone and thiochromeno-thioflavone via oxidative double hetero Michael addition using in situ generated nucleophiles. Chem Commun (Camb) 2020; 56:8826-8829. [DOI: 10.1039/d0cc03210g] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A copper catalyzed three-component synthesis of π-conjugated tetracyclic thiochromeno-quinolinone and thiochromeno-thioflavone was established via oxidative double hetero Michael addition using in situ generated nucleophiles.
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Affiliation(s)
| | - Govindasamy Sekar
- Department of Chemistry
- Indian Institute of Technology Madras
- Chennai-600036
- India
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9
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Abstract
Enzyme inhibitors are central tools for chemical biology. In this chapter we will discuss the application of chemical probes for competitive profiling of inhibitors of the quinolone biosynthesis enzyme PqsD of Pseudomonas aeruginosa. The human pathogen P. aeruginosa produces a large diversity of 2-alkyl-4(1H)-quinolones and their derivatives as metabolites with major roles in quorum sensing, virulence, and interspecies competition. PqsD is a central enzyme in the biosynthesis of all of these quinolones and hence an interesting target for inhibitor discovery. Activity-based probes with an electrophilic warhead bind covalently to active site nucleophiles like cysteine or serine. An α-chloroacetamide probe with terminal alkyne tag allowed to selectively label the active site cysteine of PqsD and was demonstrated to be a useful tool for inhibitor discovery using competition experiments. Potent inhibitors bind to the active site and thereby prevent labeling of the enzyme by the probe. Labeling intensity is quantified on polyacrylamide gels by the fluorescence of a reporter tag appended by bioorthogonal click chemistry. The competitive inhibitor profiling strategy has many advantages over traditional screening approaches and is applicable in vitro as well as in live cells. Here we describe the synthesis of an activity-based probe and provide our detailed protocols for target enzyme labeling as well as its application for the screening for potent enzyme inhibitors of PqsD by a competitive profiling strategy.
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Affiliation(s)
- Michaela Prothiwa
- Department of Chemistry, Konstanz Research School Chemical Biology, Zukunftskolleg, University of Konstanz, Konstanz, Germany
| | - Thomas Böttcher
- Department of Chemistry, Konstanz Research School Chemical Biology, Zukunftskolleg, University of Konstanz, Konstanz, Germany.
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