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Yang W, Zhang B, Tan Q, Chen Y, Chen T, Zou G, Sun B, Wang B, Yuan J, She Z. 4-Hydroxy-2-pyridone derivatives with antitumor activity produced by mangrove endophytic fungus Talaromyces sp. CY-3. Eur J Med Chem 2024; 269:116314. [PMID: 38527379 DOI: 10.1016/j.ejmech.2024.116314] [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: 01/12/2024] [Revised: 02/21/2024] [Accepted: 03/07/2024] [Indexed: 03/27/2024]
Abstract
OSMAC strategy is a useful tool for discovering series of metabolites from microorganism. Five new sambutoxin derivatives (1-2, 4, 8-9), together with seven known compounds (3, 5-7, 10-12), were isolated from Talaromyces sp. CY-3 under OSMAC strategy and guidance of molecular networking. Their planar structures and absolute configurations were determined by NMR, HRESIMS, ECD spectra and common biosynthetic pathway. In bioassay, compounds 1-12 showed cytotoxicity to tumor cell lines with IC50 values in the range of 1.76-49.13 μM. The antitumor molecular mechanism of 10 was also explored. In vitro compound 10 significantly inhibited the growth and proliferation of two lung cancer cell lines (A549 and H1703). Furthermore, colony formation, EdU analysis, flow cytometry and Western blot analysis showed that 10 could induce cell cycle arrest in G0/G1 phase by promoting the expression of p53 and p21. The molecular mechanism of its antitumor effects in vitro is that 10 arrests the cell cycle by activating the p21/CyclinD1/Rb signaling pathway and the p53 pathway. Our results identified a lead small molecule compound with efficient antitumor growth and proliferation activity.
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Affiliation(s)
- Wencong Yang
- School of Chemistry, Sun Yat-Sen University, Guangzhou, 510275, PR China; School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou, 510006, PR China
| | - Bingzhi Zhang
- School of Pharmacy, Guangdong Pharmaceutical University, Guangzhou, 510006, PR China; Key Laboratory of Tropical Disease Control, Sun Yat-Sen University, Ministry of Education, Guangzhou, 510080, PR China
| | - Qi Tan
- School of Chemistry, Sun Yat-Sen University, Guangzhou, 510275, PR China
| | - Yan Chen
- School of Chemistry, Sun Yat-Sen University, Guangzhou, 510275, PR China; School of Pharmacy, Anhui Medical University, Hefei, 230032, PR China
| | - Tao Chen
- School of Chemistry, Sun Yat-Sen University, Guangzhou, 510275, PR China
| | - Ge Zou
- School of Chemistry, Sun Yat-Sen University, Guangzhou, 510275, PR China
| | - Bing Sun
- School of Chemistry, Sun Yat-Sen University, Guangzhou, 510275, PR China
| | - Bo Wang
- School of Chemistry, Sun Yat-Sen University, Guangzhou, 510275, PR China.
| | - Jie Yuan
- Key Laboratory of Tropical Disease Control, Sun Yat-Sen University, Ministry of Education, Guangzhou, 510080, PR China; Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, PR China.
| | - Zhigang She
- School of Chemistry, Sun Yat-Sen University, Guangzhou, 510275, PR China.
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2
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Hatmaker EA, Rangel-Grimaldo M, Raja HA, Pourhadi H, Knowles SL, Fuller K, Adams EM, Lightfoot JD, Bastos RW, Goldman GH, Oberlies NH, Rokas A. Genomic and Phenotypic Trait Variation of the Opportunistic Human Pathogen Aspergillus flavus and Its Close Relatives. Microbiol Spectr 2022; 10:e0306922. [PMID: 36318036 PMCID: PMC9769809 DOI: 10.1128/spectrum.03069-22] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 10/10/2022] [Indexed: 11/16/2022] Open
Abstract
Fungal diseases affect millions of humans annually, yet fungal pathogens remain understudied. The mold Aspergillus flavus can cause both aspergillosis and fungal keratitis infections, but closely related species are not considered clinically relevant. To study the evolution of A. flavus pathogenicity, we examined genomic and phenotypic traits of two strains of A. flavus and three closely related species, Aspergillus arachidicola (two strains), Aspergillus parasiticus (two strains), and Aspergillus nomiae (one strain). We identified >3,000 orthologous proteins unique to A. flavus, including seven biosynthetic gene clusters present in A. flavus strains and absent in the three nonpathogens. We characterized secondary metabolite production for all seven strains under two clinically relevant conditions, temperature and salt concentration. Temperature impacted metabolite production in all species, whereas salinity did not affect production of any species. Strains of the same species produced different metabolites. Growth under stress conditions revealed additional heterogeneity within species. Using the invertebrate fungal disease model Galleria mellonella, we found virulence of strains of the same species varied widely; A. flavus strains were not more virulent than strains of the nonpathogens. In a murine model of fungal keratitis, we observed significantly lower disease severity and corneal thickness for A. arachidicola compared to other species at 48 h postinfection, but not at 72 h. Our work identifies variations in key phenotypic, chemical, and genomic attributes between A. flavus and its nonpathogenic relatives and reveals extensive strain heterogeneity in virulence that does not correspond to the currently established clinical relevance of these species. IMPORTANCE Aspergillus flavus is a filamentous fungus that causes opportunistic human infections, such as aspergillosis and fungal keratitis, but its close relatives are considered nonpathogenic. To begin understanding how this difference in pathogenicity evolved, we characterized variation in infection-relevant genomic, chemical, and phenotypic traits between strains of A. flavus and its relatives. We found extensive variation (or strain heterogeneity) within the pathogenic A. flavus as well as within its close relatives, suggesting that strain-level differences may play a major role in the ability of these fungi to cause disease. Surprisingly, we also found that the virulence of strains from species not considered to be pathogens was similar to that of A. flavus in both invertebrate and murine models of disease. These results contrast with previous studies on Aspergillus fumigatus, another major pathogen in the genus, for which significant differences in infection-relevant chemical and phenotypic traits are observed between closely related pathogenic and nonpathogenic species.
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Affiliation(s)
- E. Anne Hatmaker
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, USA
- Evolutionary Studies Initiative, Vanderbilt University, Nashville, Tennessee, USA
| | - Manuel Rangel-Grimaldo
- Department of Chemistry & Biochemistry, University of North Carolina at Greensboro, Greensboro, North Carolina, USA
| | - Huzefa A. Raja
- Department of Chemistry & Biochemistry, University of North Carolina at Greensboro, Greensboro, North Carolina, USA
| | - Hadi Pourhadi
- Department of Chemistry & Biochemistry, University of North Carolina at Greensboro, Greensboro, North Carolina, USA
| | - Sonja L. Knowles
- Department of Chemistry & Biochemistry, University of North Carolina at Greensboro, Greensboro, North Carolina, USA
| | - Kevin Fuller
- Department of Microbiology and Immunology, University of Oklahoma Health Science Center, Oklahoma City, Oklahoma, USA
| | - Emily M. Adams
- Department of Microbiology and Immunology, University of Oklahoma Health Science Center, Oklahoma City, Oklahoma, USA
| | - Jorge D. Lightfoot
- Department of Microbiology and Immunology, University of Oklahoma Health Science Center, Oklahoma City, Oklahoma, USA
| | - Rafael W. Bastos
- Biosciences Center, Federal University of Rio Grande do Norte, Natal, Brazil
| | - Gustavo H. Goldman
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Nicholas H. Oberlies
- Department of Chemistry & Biochemistry, University of North Carolina at Greensboro, Greensboro, North Carolina, USA
| | - Antonis Rokas
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, USA
- Evolutionary Studies Initiative, Vanderbilt University, Nashville, Tennessee, USA
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Okamoto T, Kishimoto S, Watanabe K. Isolation of Natural Prodrug-Like Metabolite by Simulating Human Prodrug Activation in Filamentous Fungus. Chem Pharm Bull (Tokyo) 2022; 70:304-308. [DOI: 10.1248/cpb.c21-01099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Takumi Okamoto
- Department of Pharmaceutical Sciences, University of Shizuoka
| | | | - Kenji Watanabe
- Department of Pharmaceutical Sciences, University of Shizuoka
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4
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Kong Y, Yang B, Zhuang Y, Zhang J, Sun D, Dong C. Research Progress on the Synthesis and Structure-Activity Relationship of Five Hypoglycemic Active Heterocycles Based on Dipeptidyl Peptidase 4 (DPP-4) Target Design. CHINESE J ORG CHEM 2022. [DOI: 10.6023/cjoc202107001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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5
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Bannykh A, Levashova E, Bakulina O, Krasavin M. New reagent space and new scope for the Castagnoli–Cushman reaction of oximes and 3-arylglutaconic anhydrides. Org Biomol Chem 2022; 20:8643-8648. [DOI: 10.1039/d2ob01675c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The Castagnoli–Cushman reaction of oximes, previously known only for homophthalic anhydride, was extended to 3-arylglutaconic anhydrides to produce a new family of cyclic hydroxamic acids from a significantly improved diversity of oxime substrates.
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Affiliation(s)
- Anton Bannykh
- Saint Petersburg State University, Saint Petersburg 199034, Russian Federation
| | - Ekaterina Levashova
- Saint Petersburg State University, Saint Petersburg 199034, Russian Federation
| | - Olga Bakulina
- Saint Petersburg State University, Saint Petersburg 199034, Russian Federation
| | - Mikhail Krasavin
- Saint Petersburg State University, Saint Petersburg 199034, Russian Federation
- Immanuel Kant Baltic Federal University, Kaliningrad 236016, Russian Federation
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6
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Labadie SS, Thai K, Grandner JM, Liu Y, Parr BT. Enyne Amides to Fused Pyridones: Scope and Limitations. J Org Chem 2021; 86:14177-14191. [PMID: 34337936 DOI: 10.1021/acs.joc.1c00688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Herein we present an investigation into the scope and mechanism for the synthesis of cyclopentyl and heterocyclic fused pyridones from the corresponding enyne amides. In the presence of a secondary amine, cyclization proceeds smoothly to form 5,6-bicyclic pyridones in 12-90% yield. The cyclization fails with enyne amides of six-membered and larger ring systems. The ring closure reaction is catalytic in nature with respect to the secondary amine and proceeds via sequential 1,6-addition of the amine, 6-exo-trig ring closure of the iminium intermediate, and subsequent elimination of the secondary amine. Computations show reduced conjugation between the enyne and amide for six-membered and larger systems, thereby providing an explanation for the inability of such enyne amides to form fused pyridones.
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Affiliation(s)
- Sharada S Labadie
- Genentech, Inc., 1 DNA Way, South San Francisco, California 94080, United States
| | - Karine Thai
- Genentech, Inc., 1 DNA Way, South San Francisco, California 94080, United States
| | - Jessica M Grandner
- Genentech, Inc., 1 DNA Way, South San Francisco, California 94080, United States
| | - Yanzhou Liu
- Genentech, Inc., 1 DNA Way, South San Francisco, California 94080, United States
| | - Brendan T Parr
- Genentech, Inc., 1 DNA Way, South San Francisco, California 94080, United States
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7
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Secondary Metabolites with α-Glucosidase Inhibitory Activity from Mangrove Endophytic Fungus Talaromyces sp. CY-3. Mar Drugs 2021; 19:md19090492. [PMID: 34564154 PMCID: PMC8465095 DOI: 10.3390/md19090492] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 08/26/2021] [Accepted: 08/27/2021] [Indexed: 11/17/2022] Open
Abstract
Eight new compounds, including two sambutoxin derivatives (1-2), two highly oxygenated cyclopentenones (7-8), four highly oxygenated cyclohexenones (9-12), together with four known sambutoxin derivatives (3-6), were isolated from semimangrove endophytic fungus Talaromyces sp. CY-3, under the guidance of molecular networking. The structures of new isolates were elucidated by analysis of detailed spectroscopic data, ECD spectra, chemical hydrolysis, 13C NMR calculation, and DP4+ analysis. In bioassays, compounds 1-5 displayed better α-glucosidase inhibitory activity than the positive control 1-deoxynojirimycin (IC50 = 80.8 ± 0.3 μM), and the IC50 value was in the range of 12.6 ± 0.9 to 57.3 ± 1.3 μM.
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8
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Forrestall KL, Burley DE, Cash MK, Pottie IR, Darvesh S. 2-Pyridone natural products as inhibitors of SARS-CoV-2 main protease. Chem Biol Interact 2020; 335:109348. [PMID: 33278462 PMCID: PMC7710351 DOI: 10.1016/j.cbi.2020.109348] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Revised: 10/05/2020] [Accepted: 11/26/2020] [Indexed: 12/16/2022]
Abstract
The disease, COVID-19, is caused by the severe acute respiratory coronavirus 2 (SARS-CoV-2) for which there is currently no treatment. The SARS-CoV-2 main protease (Mpro) is an important enzyme for viral replication. Small molecules that inhibit this protease could lead to an effective COVID-19 treatment. The 2-pyridone scaffold was previously identified as a possible key pharmacophore to inhibit SARS-CoV-2 Mpro. A search for natural, antimicrobial products with the 2-pyridone moiety was undertaken herein, and their calculated potency as inhibitors of SARS-CoV-2 Mpro was investigated. Thirty-three natural products containing the 2-pyridone scaffold were identified from the literature. An in silico methodology using AutoDock was employed to predict the binding energies and inhibition constants (Ki values) for each 2-pyridone-containing compound with SARS-CoV-2 Mpro. This consisted of molecular optimization of the 2-pyridone compound, docking of the compound with a crystal structure of SARS-CoV-2 Mpro, and evaluation of the predicted interactions and ligand-enzyme conformations. All compounds investigated bound to the active site of SARS-CoV-2 Mpro, close to the catalytic dyad (His-41 and Cys-145). Thirteen molecules had predicted Ki values <1 μM. Glu-166 formed a key hydrogen bond in the majority of the predicted complexes, while Met-165 had some involvement in the complex binding as a close contact to the ligand. Prominent 2-pyridone compounds were further evaluated for their ADMET properties. This work has identified 2-pyridone natural products with calculated potent inhibitory activity against SARS-CoV-2 Mpro and with desirable drug-like properties, which may lead to the rapid discovery of a treatment for COVID-19. 2-pyridone-scaffold is an inhibitory pharmacophore for SARS-CoV-2 Mpro. Thirty-three natural, antimicrobial products identified with 2-pyridone moiety. All 2-pyridone natural products bind to active site of SARS-CoV-2 Mproin silico. Thirteen molecules found to have potent inhibitory activity against SARS-CoV-2 Mpro. Inhibition of SARS-CoV-2 by natural 2-pyridones may lead to treatment of COVID-19.
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Affiliation(s)
- Katrina L Forrestall
- Department of Medical Neuroscience, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada
| | - Darcy E Burley
- Department of Medical Neuroscience, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada
| | - Meghan K Cash
- Department of Medical Neuroscience, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada
| | - Ian R Pottie
- Department of Chemistry and Physics, Faculty of Arts and Science, Mount Saint Vincent University, Halifax, Nova Scotia, B3M 2J6, Canada; Department of Chemistry, Faculty of Science, Saint Mary's University, Halifax, Nova Scotia, B3H 3C3, Canada
| | - Sultan Darvesh
- Department of Medical Neuroscience, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada; Department of Chemistry and Physics, Faculty of Arts and Science, Mount Saint Vincent University, Halifax, Nova Scotia, B3M 2J6, Canada; Department of Medicine (Neurology), Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada.
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9
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Uka V, Cary JW, Lebar MD, Puel O, De Saeger S, Diana Di Mavungu J. Chemical repertoire and biosynthetic machinery of the Aspergillus flavus secondary metabolome: A review. Compr Rev Food Sci Food Saf 2020; 19:2797-2842. [PMID: 33337039 DOI: 10.1111/1541-4337.12638] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 08/23/2020] [Accepted: 08/24/2020] [Indexed: 12/18/2022]
Abstract
Filamentous fungi represent a rich source of extrolites, including secondary metabolites (SMs) comprising a great variety of astonishing structures and interesting bioactivities. State-of-the-art techniques in genome mining, genetic manipulation, and secondary metabolomics have enabled the scientific community to better elucidate and more deeply appreciate the genetic and biosynthetic chemical arsenal of these microorganisms. Aspergillus flavus is best known as a contaminant of food and feed commodities and a producer of the carcinogenic family of SMs, aflatoxins. This fungus produces many SMs including polyketides, ribosomal and nonribosomal peptides, terpenoids, and other hybrid molecules. This review will discuss the chemical diversity, biosynthetic pathways, and biological/ecological role of A. flavus SMs, as well as their significance concerning food safety and security.
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Affiliation(s)
- Valdet Uka
- Center of Excellence in Mycotoxicology and Public Health, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium.,Division of Pharmacy, Faculty of Medicine, University of Pristina, Pristina, Kosovo
| | - Jeffrey W Cary
- Southern Regional Research Center, USDA-ARS, New Orleans, Louisiana
| | - Matthew D Lebar
- Southern Regional Research Center, USDA-ARS, New Orleans, Louisiana
| | - Olivier Puel
- Toxalim (Research Centre in Food Toxicology), INRAE, ENVT, INP-Purpan, UPS, Université de Toulouse, Toulouse, France
| | - Sarah De Saeger
- Center of Excellence in Mycotoxicology and Public Health, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium
| | - José Diana Di Mavungu
- Center of Excellence in Mycotoxicology and Public Health, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium
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10
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Qiao Y, Xu Q, Feng W, Tao L, Li XN, Liu J, Zhu H, Lu Y, Wang J, Qi C, Xue Y, Zhang Y. Asperpyridone A: An Unusual Pyridone Alkaloid Exerts Hypoglycemic Activity through the Insulin Signaling Pathway. JOURNAL OF NATURAL PRODUCTS 2019; 82:2925-2930. [PMID: 31490677 DOI: 10.1021/acs.jnatprod.9b00188] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
A pyridone alkaloid, asperpyridone A (1), which possesses an unusual pyrano[3,2-c]pyridine scaffold, was isolated from solid cultures of the endophytic fungus Aspergillus sp. TJ23. Its structure, including its absolute configuration, was determined using a combination of nuclear magnetic resonance, high-resolution electrospray ionization mass spectrometry, quantum chemical calculations (electronic circular dichroism), and X-ray crystallography. In vitro bioassays demonstrated that asperpyridone A (1) could function as a potential hypoglycemic agent, which exhibited pronounced glucose uptake effect in liver HepG2 cells, under both normal and insulin-resistant conditions, with higher efficacy than metformin. The underlying mechanism of asperpyridone A was elucidated by analyzing the genes expressed, the Gene Ontology (GO) function enrichment, the protein interaction network, and real-time quantitative reverse transcription polymerase chain reaction, which suggested that asperpyridone A exhibits hypoglycemic activity by activating the insulin signaling pathway. Moreover, on the basis of the hypoglycemic potency, fibroblast growth factor 21 (FGF21) was determined to be a potential target for asperpyridone A.
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Affiliation(s)
- Yuben Qiao
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, Tongji Medical College , Huazhong University of Science and Technology , Wuhan 430030 , Hubei Province , People's Republic of China
| | - Qianqian Xu
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, Tongji Medical College , Huazhong University of Science and Technology , Wuhan 430030 , Hubei Province , People's Republic of China
| | - Wenya Feng
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, Tongji Medical College , Huazhong University of Science and Technology , Wuhan 430030 , Hubei Province , People's Republic of China
| | - Li Tao
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, Tongji Medical College , Huazhong University of Science and Technology , Wuhan 430030 , Hubei Province , People's Republic of China
| | - Xiao-Nian Li
- State Key Laboratory of Phytochemistry and Plant Resourcses in West China , Kunming Institute of Botany, Chinese Academy of Sciences , Kunming 650201 , Yunnan Province , People's Republic of China
| | - Junjun Liu
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, Tongji Medical College , Huazhong University of Science and Technology , Wuhan 430030 , Hubei Province , People's Republic of China
| | - Hucheng Zhu
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, Tongji Medical College , Huazhong University of Science and Technology , Wuhan 430030 , Hubei Province , People's Republic of China
| | - Yuanyuan Lu
- Department of Pharmacy, Tongji Hospital, Tongji Medical College , Huazhong University of Science and Technology , Wuhan 430030 , Hubei Province , People's Republic of China
| | - Jianping Wang
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, Tongji Medical College , Huazhong University of Science and Technology , Wuhan 430030 , Hubei Province , People's Republic of China
| | - Changxing Qi
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, Tongji Medical College , Huazhong University of Science and Technology , Wuhan 430030 , Hubei Province , People's Republic of China
| | - Yongbo Xue
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, Tongji Medical College , Huazhong University of Science and Technology , Wuhan 430030 , Hubei Province , People's Republic of China
- School of Pharmaceutical Sciences (Shenzhen) , Sun Yat-Sen University , Guangzhou 510275 , People's Republic of China
| | - Yonghui Zhang
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, Tongji Medical College , Huazhong University of Science and Technology , Wuhan 430030 , Hubei Province , People's Republic of China
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11
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The Aspergillus flavus rtfA Gene Regulates Plant and Animal Pathogenesis and Secondary Metabolism. Appl Environ Microbiol 2019; 85:AEM.02446-18. [PMID: 30635379 DOI: 10.1128/aem.02446-18] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Accepted: 12/31/2018] [Indexed: 02/04/2023] Open
Abstract
Aspergillus flavus is an opportunistic fungal plant and human pathogen and a producer of mycotoxins, including aflatoxin B1 (AFB1). As part of our ongoing studies to elucidate the biological functions of the A. flavus rtfA gene, we examined its role in the pathogenicity of both plant and animal model systems. rtfA encodes a putative RNA polymerase II (Pol II) transcription elongation factor previously characterized in Saccharomyces cerevisiae, Aspergillus nidulans, and Aspergillus fumigatus, where it was shown to regulate several important cellular processes, including morphogenesis and secondary metabolism. In addition, an initial study in A. flavus indicated that rtfA also influences development and production of AFB1; however, its effect on virulence is unknown. The current study reveals that the rtfA gene is indispensable for normal pathogenicity in plants when using peanut seed as an infection model, as well as in animals, as shown in the Galleria mellonella infection model. Interestingly, rtfA positively regulates several processes known to be necessary for successful fungal invasion and colonization of host tissue, such as adhesion to surfaces, protease and lipase activity, cell wall composition and integrity, and tolerance to oxidative stress. In addition, metabolomic analysis revealed that A. flavus rtfA affects the production of several secondary metabolites, including AFB1, aflatrem, leporins, aspirochlorine, ditryptophenaline, and aflavinines, supporting a role of rtfA as a global regulator of secondary metabolism. Heterologous complementation of an A. flavus rtfA deletion strain with rtfA homologs from A. nidulans or S. cerevisiae fully rescued the wild-type phenotype, indicating that these rtfA homologs are functionally conserved among these three species.IMPORTANCE In this study, the epigenetic global regulator rtfA, which encodes a putative RNA-Pol II transcription elongation factor-like protein, was characterized in the mycotoxigenic and opportunistic pathogen A. flavus Specifically, its involvement in A. flavus pathogenesis in plant and animal models was studied. Here, we show that rtfA positively regulates A. flavus virulence in both models. Furthermore, rtfA-dependent effects on factors necessary for successful invasion and colonization of host tissue by A. flavus were also assessed. Our study indicates that rtfA plays a role in A. flavus adherence to surfaces, hydrolytic activity, normal cell wall formation, and response to oxidative stress. This study also revealed a profound effect of rtfA on the metabolome of A. flavus, including the production of potent mycotoxins.
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12
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Aspergillus flavus Secondary Metabolites: More than Just Aflatoxins. Food Saf (Tokyo) 2018; 6:7-32. [PMID: 32231944 DOI: 10.14252/foodsafetyfscj.2017024] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 03/09/2018] [Indexed: 11/21/2022] Open
Abstract
Aspergillus flavus is best known for producing the family of potent carcinogenic secondary metabolites known as aflatoxins. However, this opportunistic plant and animal pathogen also produces numerous other secondary metabolites, many of which have also been shown to be toxic. While about forty of these secondary metabolites have been identified from A. flavus cultures, analysis of the genome has predicted the existence of at least 56 secondary metabolite gene clusters. Many of these gene clusters are not expressed during growth of the fungus on standard laboratory media. This presents researchers with a major challenge of devising novel strategies to manipulate the fungus and its genome so as to activate secondary metabolite gene expression and allow identification of associated cluster metabolites. In this review, we discuss the genetic, biochemical and bioinformatic methods that are being used to identify previously uncharacterized secondary metabolite gene clusters and their associated metabolites. It is important to identify as many of these compounds as possible to determine their bioactivity with respect to fungal development, survival, virulence and especially with respect to any potential synergistic toxic effects with aflatoxin.
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13
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Gilbert MK, Medina A, Mack BM, Lebar MD, Rodríguez A, Bhatnagar D, Magan N, Obrian G, Payne G. Carbon Dioxide Mediates the Response to Temperature and Water Activity Levels in Aspergillus flavus during Infection of Maize Kernels. Toxins (Basel) 2017; 10:E5. [PMID: 29271897 PMCID: PMC5793092 DOI: 10.3390/toxins10010005] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 11/17/2017] [Accepted: 12/14/2017] [Indexed: 12/20/2022] Open
Abstract
Aspergillus flavus is a saprophytic fungus that may colonize several important crops, including cotton, maize, peanuts and tree nuts. Concomitant with A. flavus colonization is its potential to secrete mycotoxins, of which the most prominent is aflatoxin. Temperature, water activity (aw) and carbon dioxide (CO₂) are three environmental factors shown to influence the fungus-plant interaction, which are predicted to undergo significant changes in the next century. In this study, we used RNA sequencing to better understand the transcriptomic response of the fungus to aw, temperature, and elevated CO₂ levels. We demonstrate that aflatoxin (AFB₁) production on maize grain was altered by water availability, temperature and CO₂. RNA-Sequencing data indicated that several genes, and in particular those involved in the biosynthesis of secondary metabolites, exhibit different responses to water availability or temperature stress depending on the atmospheric CO₂ content. Other gene categories affected by CO₂ levels alone (350 ppm vs. 1000 ppm at 30 °C/0.99 aw), included amino acid metabolism and folate biosynthesis. Finally, we identified two gene networks significantly influenced by changes in CO₂ levels that contain several genes related to cellular replication and transcription. These results demonstrate that changes in atmospheric CO₂ under climate change scenarios greatly influences the response of A. flavus to water and temperature when colonizing maize grain.
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Affiliation(s)
- Matthew K Gilbert
- USDA/Agricultural Research Service, 1100 Robert E Lee Blvd., New Orleans, LA 70124, USA.
| | - Angel Medina
- Applied Mycology Group, Biotechnology Centre, Cranfield University, Silsoe, Bedford MK45 4DT, UK.
| | - Brian M Mack
- USDA/Agricultural Research Service, 1100 Robert E Lee Blvd., New Orleans, LA 70124, USA.
| | - Matthew D Lebar
- USDA/Agricultural Research Service, 1100 Robert E Lee Blvd., New Orleans, LA 70124, USA.
| | - Alicia Rodríguez
- Food Hygiene and Safety, Meat and Meat products Research Institute, University of Extremadura, 10003 Caceres, Spain.
| | - Deepak Bhatnagar
- USDA/Agricultural Research Service, 1100 Robert E Lee Blvd., New Orleans, LA 70124, USA.
| | - Naresh Magan
- Applied Mycology Group, Biotechnology Centre, Cranfield University, Silsoe, Bedford MK45 4DT, UK.
| | - Gregory Obrian
- Department of Entomology and Plant Pathology, 223 Partners III, P.O. Box 7567, North Carolina State University, Raleigh, NC 27695, USA.
| | - Gary Payne
- Department of Entomology and Plant Pathology, 223 Partners III, P.O. Box 7567, North Carolina State University, Raleigh, NC 27695, USA.
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14
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Abstract
This review covers the literature published in 2014 for marine natural products (MNPs), with 1116 citations (753 for the period January to December 2014) referring to compounds isolated from marine microorganisms and phytoplankton, green, brown and red algae, sponges, cnidarians, bryozoans, molluscs, tunicates, echinoderms, mangroves and other intertidal plants and microorganisms. The emphasis is on new compounds (1378 in 456 papers for 2014), together with the relevant biological activities, source organisms and country of origin. Reviews, biosynthetic studies, first syntheses, and syntheses that lead to the revision of structures or stereochemistries, have been included.
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Affiliation(s)
- John W Blunt
- Department of Chemistry, University of Canterbury, Christchurch, New Zealand.
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15
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Sy-Cordero AA, Figueroa M, Raja HA, Meza Aviña ME, Croatt MP, Adcock AF, Kroll DJ, Wani MC, Pearce CJ, Oberlies NH. Spiroscytalin, a new tetramic acid and other metabolites of mixed biogenesis from Scytalidium cuboideum. Tetrahedron 2015; 71:8899-904. [PMID: 26525642 DOI: 10.1016/j.tet.2015.09.073] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Spiroscytalin (1), a new tetramic acid that possesses an uncommon spiro-ring fusion between a polyketide-derived octalin ring system and a 2,4-pyrrolidinedione, along with two known compounds, leporin B (2) and purpactin A (3), were isolated from a solid phase culture of the fungus Scytalidium cuboideum (MSX 68345). The molecular connectivity of 1-3 was determined using NMR spectroscopy and mass spectrometry. The relative configurations of 1 and 2 were determined by NOESY experiments. The absolute configuration of 1 was determined by electronic circular dichroism (ECD) via a combination of experimental measurements and computational calculations. While leporin B was known, it displayed activities that had not been reported previously, including cytotoxicity against three human tumor cell lines and antibacterial activity against Candida albicans and Staphylococcus aureus.
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Affiliation(s)
- Arlene A Sy-Cordero
- University of North Carolina at Greensboro, Department of Chemistry and Biochemistry, Greensboro, NC 27402, United States
| | - Mario Figueroa
- Facultad de Química, Universidad Nacional Autónoma de México, Mexico DF 04510, Mexico
| | - Huzefa A Raja
- University of North Carolina at Greensboro, Department of Chemistry and Biochemistry, Greensboro, NC 27402, United States
| | - Maria Elena Meza Aviña
- University of North Carolina at Greensboro, Department of Chemistry and Biochemistry, Greensboro, NC 27402, United States
| | - Mitchell P Croatt
- University of North Carolina at Greensboro, Department of Chemistry and Biochemistry, Greensboro, NC 27402, United States
| | - Audrey F Adcock
- Department of Pharmaceutical Sciences, BRITE, North Carolina Central University, Durham, NC 27707, United States
| | - David J Kroll
- Department of Pharmaceutical Sciences, BRITE, North Carolina Central University, Durham, NC 27707, United States
| | - Mansukh C Wani
- Natural Products Laboratory, Research Triangle Institute, Research Triangle Park, NC 27709, United States
| | | | - Nicholas H Oberlies
- University of North Carolina at Greensboro, Department of Chemistry and Biochemistry, Greensboro, NC 27402, United States
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16
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Arroyo-Manzanares N, Diana Di Mavungu J, Uka V, Malysheva SV, Cary JW, Ehrlich KC, Vanhaecke L, Bhatnagar D, De Saeger S. Use of UHPLC high-resolution Orbitrap mass spectrometry to investigate the genes involved in the production of secondary metabolites inAspergillus flavus. Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2015; 32:1656-73. [DOI: 10.1080/19440049.2015.1071499] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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17
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Cary JW, Uka V, Han Z, Buyst D, Harris-Coward PY, Ehrlich KC, Wei Q, Bhatnagar D, Dowd PF, Martens SL, Calvo AM, Martins JC, Vanhaecke L, Coenye T, De Saeger S, Di Mavungu JD. An Aspergillus flavus secondary metabolic gene cluster containing a hybrid PKS–NRPS is necessary for synthesis of the 2-pyridones, leporins. Fungal Genet Biol 2015; 81:88-97. [DOI: 10.1016/j.fgb.2015.05.010] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Revised: 05/22/2015] [Accepted: 05/26/2015] [Indexed: 01/04/2023]
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18
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Sun K, Li Y, Guo L, Wang Y, Liu P, Zhu W. Indole diterpenoids and isocoumarin from the fungus, Aspergillus flavus, isolated from the prawn, Penaeus vannamei. Mar Drugs 2014; 12:3970-81. [PMID: 24983640 PMCID: PMC4113809 DOI: 10.3390/md12073970] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Revised: 06/03/2014] [Accepted: 06/13/2014] [Indexed: 01/20/2023] Open
Abstract
Two new indole-diterpenoids (1 and 2) and a new isocoumarin (3), along with the known β-aflatrem (4), paspalinine (5), leporin B (6), α-cyclopiazonic acid (7), iso-α-cyclopiazonic acid (8), ditryptophenaline (9), aflatoxin B1 (10), 7-O-acetylkojic acid (11) and kojic acid (12), were isolated from the fermentation broth of the marine-derived fungus, Aspergillus flavus OUCMDZ-2205. The structures of Compounds 1–12 were elucidated by spectroscopic analyses, quantum ECD calculations and the chemical method. New Compound 1 exhibited antibacterial activity against Staphylococcus aureus with a MIC value of 20.5 μM. Both new Compounds 1 and 2 could arrest the A549 cell cycle in the S phase at a concentration of 10 μM. Compound 1 showed PKC-beta inhibition with an IC50 value of 15.6 μM. In addition, the absolute configurations of the known compounds, 4–6 and leporin A (6a), were also determined for the first time.
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Affiliation(s)
- Kunlai Sun
- Key Laboratory of Marine Drugs, Ministry of Education of China, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China.
| | - Ye Li
- Key Laboratory of Marine Drugs, Ministry of Education of China, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China.
| | - Lei Guo
- Key Lab of Marine Biotechnology, Huaihai Institute of Technology, Lianyungang 222005, China.
| | - Yi Wang
- Key Laboratory of Marine Drugs, Ministry of Education of China, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China.
| | - Peipei Liu
- Key Laboratory of Marine Drugs, Ministry of Education of China, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China.
| | - Weiming Zhu
- Key Laboratory of Marine Drugs, Ministry of Education of China, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China.
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19
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Biomimetic conversion of (-)-fusoxypyridone and (-)-oxysporidinone to (-)-sambutoxin: further evidence for the structure of the tricyclic pyridone alkaloid, (-)-fusoxypyridone. Bioorg Med Chem Lett 2011; 21:2327-9. [PMID: 21419624 DOI: 10.1016/j.bmcl.2011.02.091] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2011] [Revised: 02/16/2011] [Accepted: 02/22/2011] [Indexed: 11/22/2022]
Abstract
Biomimetic-type reactions of the tricyclic pyridone alkaloid, (-)-fusoxypyridone [(-)-4,6'-anhydrooxysporidinone] (1), recently encountered in an endophytic strain of Fusarium oxysporum, and (-)-oxysporidinone (2) afforded (-)-sambutoxin (3) and an analogue of 1, identified as (-)-1'(6')-dehydro-4,6'-anhydrooxysporidinone (4), thus confirming the structure previously proposed for 1 and suggesting that 1-3 bear the same relative stereochemistry. Oxidation of 4 with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) yielded a hitherto unknown sambutoxin analogue, (-)-4,2'-anhydrosambutoxin (5).
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20
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Rubinov DB, Rubinova IL, Lakhvich FA. Synthesis and keto-enol tautomerism of 6-alkyl-1-alkoxypyridine-2,4-diones. RUSSIAN JOURNAL OF ORGANIC CHEMISTRY 2011. [DOI: 10.1134/s1070428011020199] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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21
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Jessen HJ, Gademann K. 4-Hydroxy-2-pyridone alkaloids: Structures and synthetic approaches. Nat Prod Rep 2010; 27:1168-85. [PMID: 20532354 DOI: 10.1039/b911516c] [Citation(s) in RCA: 171] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Henning Jacob Jessen
- University of Basel, Department of Chemistry, St. Johanns-Ring 19, CH-4056, Basel, Switzerland
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22
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Kemami Wangun HV, Hertweck C. Epicoccarines A, B and epipyridone: tetramic acids and pyridone alkaloids from an Epicoccum sp. associated with the tree fungus Pholiota squarrosa. Org Biomol Chem 2007; 5:1702-5. [PMID: 17520137 DOI: 10.1039/b702378b] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Investigation of the metabolic profile of a fungus (Epicoccum sp.) isolated from the fruiting body of the tree fungus Pholiota squarrosa led to the discovery of two novel tetramic acid derivatives, epicoccarine A (2) and B (3), as well as a new pyridone alkaloid, epipyridone (1), with an unusually cyclized side chain. It appears that 1 is biogenetically derived from the ring expansion of 2 followed by a proposed hetero-Diels-Alder reaction. 2 shows selective antibacterial activity against Gram positive bacteria, in particular Mycobacterium vaccae.
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Affiliation(s)
- Hilaire V Kemami Wangun
- Dept. Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology, Beutenbergstr. 11a, 07745 Jena, Germany
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23
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Conreaux D, Bossharth E, Monteiro N, Desbordes P, Vors JP, Balme G. Flexible Strategy for Differentially 3,5-Disubstituted 4-Oxypyridin-2(1H)-ones Based on Site-Selective Pd-Catalyzed Cross-Coupling Reactions. Org Lett 2006; 9:271-4. [PMID: 17217282 DOI: 10.1021/ol062721u] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
3,5-Dihalogeno-4-methoxy-N-methylpyridin-2(1H)-ones have been shown to undergo single Suzuki coupling reactions in a site-selective fashion. Monoarylations occur at the C-5 position preferentially, thus leaving the remaining C-3 halide free for further functionalization, to finally access differentially 3,5-disubstituted 2-pyridones. This two-step strategy has been applied to the elaboration of the 3-acyl-5-aryl-4-oxy-2-pyridone subunit that is prevalent in numerous bioactive natural products. [reaction: see text].
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Affiliation(s)
- David Conreaux
- Laboratoire de Synthèse Organométallique et Molécules Bioactives, CNRS UMR 5181, Université Claude Bernard-Lyon 1, ESCPE Lyon 43, Boulevard du 11 Novembre 1918, 69622 Villeurbanne, France
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24
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Fujita Y, Oguri H, Oikawa H. Biosynthetic studies on the antibiotics PF1140: a novel pathway for a 2-pyridone framework. Tetrahedron Lett 2005. [DOI: 10.1016/j.tetlet.2005.06.115] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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25
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Abstract
A potentially general approach for elucidating the absolute configuration of N-hydroxypyridone antibiotics has been developed. One member of this family of antibiotics, PF1140, was efficiently purified from a crude fungal extract following allylation of its N-hydroxyl group. Removal of the resultant allyl group permitted regeneration of the N-hydroxyl group as well as conversion into the corresponding pyridone derivative. The stereochemistry of PF1140 including the absolute configuration was established by X-ray crystallographic analysis of the S-2-methoxy-2-(1-naphthyl)propionic ester derivative.
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Affiliation(s)
- Yuta Fujita
- Division of Chemistry, Graduate School of Science, Hokkaido University, Sapporo 060-0810, Japan.
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