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Khan MEI, Cassini TL, Petrini M, Palmieri A. Synthesis of 3,5-disubstituted isoxazoles by domino reductive Nef reaction/cyclization of β-nitroenones. Org Biomol Chem 2024; 22:3299-3303. [PMID: 38577730 DOI: 10.1039/d4ob00232f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/06/2024]
Abstract
β-Nitroenones can be efficiently converted into 3,5-disubstituted isoxazoles by using tin(II)chloride dihydrate and ethyl acetate as a reducing agent and solvent, respectively. Products are obtained in good yields and several functional groups are tolerated thanks to the mild reaction conditions.
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Affiliation(s)
| | - Tomas Lighuen Cassini
- University of Camerino, ChIP Research Center, Via Madonna delle Carceri, 62032 Camerino, MC, Italy.
| | - Marino Petrini
- University of Camerino, ChIP Research Center, Via Madonna delle Carceri, 62032 Camerino, MC, Italy.
| | - Alessandro Palmieri
- University of Camerino, ChIP Research Center, Via Madonna delle Carceri, 62032 Camerino, MC, Italy.
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2
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Treuer AV, Faúndez M, Ebensperger R, Hovelmeyer E, Vergara-Jaque A, Perera-Sardiña Y, Gutierrez M, Fuentealba R, González DR. New NADPH Oxidase 2 Inhibitors Display Potent Activity against Oxidative Stress by Targeting p22 phox-p47 phox Interactions. Antioxidants (Basel) 2023; 12:1441. [PMID: 37507978 PMCID: PMC10376059 DOI: 10.3390/antiox12071441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 07/03/2023] [Accepted: 07/13/2023] [Indexed: 07/30/2023] Open
Abstract
NADPH oxidase (NOX2) is responsible for reactive oxygen species (ROS) production in neutrophils and has been recognized as a key mediator in inflammatory and cardiovascular pathologies. Nevertheless, there is a lack of specific NOX2 pharmacological inhibitors. In medicinal chemistry, heterocyclic compounds are essential scaffolds for drug design, and among them, indole is a very versatile pharmacophore. We tested the hypothesis that indole heteroaryl-acrylonitrile derivatives may serve as NOX2 inhibitors by evaluating the capacity of 19 of these molecules to inhibit NOX2-derived ROS production in human neutrophils (HL-60 cells). Of these compounds, C6 and C14 exhibited concentration-dependent inhibition of NOX2 (IC50~1 µM). These molecules also reduced NOX2-derived oxidative stress in cardiomyocytes and prevented cardiac damage induced by ischemia-reperfusion. Compound C6 significantly reduced the membrane translocation of p47phox, a cytosolic subunit that is required for NOX2 activation. Molecular docking analyses of the binding modes of these molecules with p47phox indicated that C6 and C14 interact with specific residues in the inner part of the groove of p47phox, the binding cavity for p22phox. This combination of methods showed that novel indole heteroaryl acrylonitriles represent interesting lead compounds for developing specific and potent NOX2 inhibitors.
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Affiliation(s)
- Adriana V Treuer
- Department of Basic Biomedical Sciences, School of Health Sciences, Universidad de Talca, Avenida Lircay s/n, Talca 3460000, Chile
| | - Mario Faúndez
- Departamento de Farmacia, Escuela de Química y Farmacia, Facultad de Química y de Farmacia, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, Santiago 7820436, Chile
| | - Roberto Ebensperger
- Escuela de Química y Farmacia, Facultad de Medicina y Ciencia, Universidad San Sebastián, Santiago 7510157, Chile
| | - Erwin Hovelmeyer
- Center for Bioinformatics, Simulation and Modeling, Faculty of Engineering, Universidad de Talca, Avenida Lircay s/n, Talca 3460000, Chile
| | - Ariela Vergara-Jaque
- Center for Bioinformatics, Simulation and Modeling, Faculty of Engineering, Universidad de Talca, Avenida Lircay s/n, Talca 3460000, Chile
| | - Yunier Perera-Sardiña
- Department of Basic Biomedical Sciences, School of Health Sciences, Universidad de Talca, Avenida Lircay s/n, Talca 3460000, Chile
| | - Margarita Gutierrez
- Organic Synthesis Laboratory and Biological Activity (LSO-Act-Bio), Institute of Chemistry of Natural Resources, Universidad de Talca, Talca 3460000, Chile
| | - Roberto Fuentealba
- Escuela de Enfermería, Facultad de Salud, Universidad Santo Tomás, Talca 3460000, Chile
| | - Daniel R González
- Department of Basic Biomedical Sciences, School of Health Sciences, Universidad de Talca, Avenida Lircay s/n, Talca 3460000, Chile
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3
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Novel Synthesis of Dihydroisoxazoles by p-TsOH-Participated 1,3-Dipolar Cycloaddition of Dipolarophiles withα-Nitroketones. Molecules 2023; 28:molecules28062565. [PMID: 36985536 PMCID: PMC10052018 DOI: 10.3390/molecules28062565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 03/06/2023] [Accepted: 03/06/2023] [Indexed: 03/16/2023] Open
Abstract
This article reports in detail a method for the synthesis of 3-benzoxoxazoline by the reaction of alkenes (alkynes) and a variety of α-nitroketones in the presence of p-TsOH. The scope of alkenes is broad, including different alkenes and the alkyne. This reaction provides a convenient and efficient synthetic method of 3-benzoylisoxazolines.
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4
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Thakur A, Verma M, Bharti R, Sharma R. Oxazole and isoxazole: From one-pot synthesis to medical applications. Tetrahedron 2022. [DOI: 10.1016/j.tet.2022.132813] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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5
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Karunakaran KB, Thiyagaraj A, Santhakumar K. Novel insights on acetylcholinesterase inhibition by Convolvulus pluricaulis, scopolamine and their combination in zebrafish. NATURAL PRODUCTS AND BIOPROSPECTING 2022; 12:6. [PMID: 35212831 PMCID: PMC8881542 DOI: 10.1007/s13659-022-00332-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 02/16/2022] [Indexed: 06/14/2023]
Abstract
Acetylcholinesterase (AChE) inhibitors increase the retention of acetylcholine (ACh) in synapses. Although they alleviate cognitive deficits in Alzheimer's disease, their limited benefits warrant investigations of plant extracts with similar properties. We studied the anti-AChE activity of Convolvulus pluricaulis (CP) in a zebrafish model of cognitive impairment induced by scopolamine (SCOP). CP is a perennial herb with anti-amnesiac and anxiolytic properties. It contains alkaloid, anthocyanin, coumarin, flavonoid, phytosterol and triterpenoid components. Isoxazole (ISOX) was used as a positive control for AChE inhibition. CP-treated 168 hpf larvae showed a similar pattern of AChE inhibition (in the myelencephalon and somites) as that of ISOX-treated larvae. CP was superior to ISOX as evidenced by the retention of avoidance response behavior in adult zebrafish. Molecular docking studies indicated that ISOX binds Ser203 of the catalytic triad on the human AChE. The active components of CP-scopoletin and kaempferol-were bound by His447 of the catalytic triad, the anionic subsite of the catalytic center, and the peripheral anionic site. This suggested the ability of CP to mediate both competitive and non-competitive modes of inhibition. Surprisingly, SCOP showed AChE inhibition in larvae, possibly mediated via the choline-binding sites. CP + SCOP induced a concentration-dependent increase in AChE inhibition and ACh depletion. Abnormal motor responses were observed with ISOX, CP, ISOX + SCOP, and CP + SCOP, indicative of undesirable effects on the peripheral cholinergic system. Our study proposes the examination of CP, SCOP, and CP + SCOP as potential AChE inhibitors for their ability to modulate cognitive deficits.
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Affiliation(s)
| | - Anand Thiyagaraj
- Department of Genetic Engineering, SRM Institute of Science and Technology, Kattankulathur, 603 203, India
| | - Kirankumar Santhakumar
- Department of Genetic Engineering, SRM Institute of Science and Technology, Kattankulathur, 603 203, India.
- Zebrafish Genetics Laboratory, Department of Genetic Engineering, SRM Institute of Science and Technology, Kattankulathur, 603 203, India.
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6
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Elkina NA, Shchegolkov EV, Burgart YV, Agafonova NA, Perminova AN, Gerasimova NA, Makhaeva GF, Rudakova EV, Kovaleva NV, Boltneva NP, Serebryakova OG, Borisevich SS, Evstigneeva NP, Zilberberg NV, Kungurov NV, Saloutin VI. Synthesis and biological evaluation of polyfluoroalkyl-containing 4-arylhydrazinylidene-isoxazoles as antifungal agents with antioxidant activity. J Fluor Chem 2022. [DOI: 10.1016/j.jfluchem.2021.109935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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7
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Muto K, Kumagai T, Kakiuchi F, Kochi T. Remote Arylative Substitution of Alkenes Possessing an Acetoxy Group via β-Acetoxy Elimination. Angew Chem Int Ed Engl 2021; 60:24500-24504. [PMID: 34510680 DOI: 10.1002/anie.202111396] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Indexed: 12/14/2022]
Abstract
Palladium-catalyzed remote arylative substitution was achieved for the reaction of arylboronic acids with alkenes possessing a distant acetoxy group to provide arylation products having an alkene moiety at the remote position. The use of β-acetoxy elimination as a key step in the catalytic cycle allowed for regioselective formation of unstabilized alkenes after chain walking. This reaction was applicable to various arylboronic acids as well as alkene substrates.
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Affiliation(s)
- Kazuma Muto
- Department of Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, 223-8522, Japan
| | - Takaaki Kumagai
- Department of Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, 223-8522, Japan
| | - Fumitoshi Kakiuchi
- Department of Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, 223-8522, Japan
| | - Takuya Kochi
- Department of Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, 223-8522, Japan
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8
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Muto K, Kumagai T, Kakiuchi F, Kochi T. Remote Arylative Substitution of Alkenes Possessing an Acetoxy Group via β‐Acetoxy Elimination. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202111396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Kazuma Muto
- Department of Chemistry Faculty of Science and Technology Keio University 3-14-1 Hiyoshi, Kohoku-ku Yokohama 223-8522 Japan
| | - Takaaki Kumagai
- Department of Chemistry Faculty of Science and Technology Keio University 3-14-1 Hiyoshi, Kohoku-ku Yokohama 223-8522 Japan
| | - Fumitoshi Kakiuchi
- Department of Chemistry Faculty of Science and Technology Keio University 3-14-1 Hiyoshi, Kohoku-ku Yokohama 223-8522 Japan
| | - Takuya Kochi
- Department of Chemistry Faculty of Science and Technology Keio University 3-14-1 Hiyoshi, Kohoku-ku Yokohama 223-8522 Japan
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9
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Das S, Chanda K. An overview of metal-free synthetic routes to isoxazoles: the privileged scaffold. RSC Adv 2021; 11:32680-32705. [PMID: 35493554 PMCID: PMC9042182 DOI: 10.1039/d1ra04624a] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 09/11/2021] [Indexed: 12/19/2022] Open
Abstract
In the field of drug discovery, isoxazole is a five-membered heterocyclic moiety commonly found in many commercially available drugs. In view of their enormous significance, it is always imperative to unleash new eco-friendly synthetic strategies. Among various novel synthetic techniques in use for isoxazole synthesis, most synthetic methods employ Cu(i) or Ru(ii) as catalysts for (3 + 2) cycloaddition reaction. The particular disadvantages associated with metal-catalyzed reactions are high costs, low abundance, toxicity, a significant generation of waste, and difficulty to separate from the reaction mixtures. In view of these drawbacks, it is always imperative to develop alternate metal-free synthetic routes. This review article highlights a comprehensive overview on the potential application of metal-free synthetic routes for the synthesis of isoxazoles with significant biological interests.
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Affiliation(s)
- Soumyadip Das
- Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology Vellore-632014 India
| | - Kaushik Chanda
- Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology Vellore-632014 India
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10
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Popov AV, Kobelevskaya VA, Titov ID, Larina LI, Rozentsveig IB. Synthesis of 5-Chloroisoxazoles Derived from 2,2-Dichlorovinyl Ketones. RUSSIAN JOURNAL OF ORGANIC CHEMISTRY 2021. [DOI: 10.1134/s107042802011010x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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11
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Agrawal N, Mishra P. The synthetic and therapeutic expedition of isoxazole and its analogs. Med Chem Res 2018; 27:1309-1344. [PMID: 32214770 PMCID: PMC7079875 DOI: 10.1007/s00044-018-2152-6] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Accepted: 02/01/2018] [Indexed: 11/28/2022]
Abstract
Isoxazole, constituting an important family of five-membered heterocycles with one oxygen atom and one nitrogen atom at adjacent positions is of immense importance because of its wide spectrum of biological activities and therapeutic potential. It is, therefore, of prime importance that the development of new synthetic strategies and designing of new isoxazole derivatives should be based on the most recent knowledge emerging from the latest research. This review is an endeavor to highlight the progress in the chemistry and biological activity of isoxazole derivatives which could provide a low-height flying bird's eye view of isoxazole derivatives to the medicinal chemists for the development of clinically viable drugs using this information.
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Affiliation(s)
- Neetu Agrawal
- Institute of Pharmaceutical Research, GLA University, Mathura, U.P. India
| | - Pradeep Mishra
- Institute of Pharmaceutical Research, GLA University, Mathura, U.P. India
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12
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Acosta P, Insuasty B, Abonia R, Gutierrez M, Quiroga J. Synthesis of novel 7-aryl and 7-spiropyrazolo[4′,3′:5,6]pyrido[2,3-d]pyrimidine derivatives and their study as AChE inhibitors. Mol Divers 2017; 21:943-955. [DOI: 10.1007/s11030-017-9774-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 07/24/2017] [Indexed: 10/19/2022]
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13
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Bonacorso HG, Ketzer A, Garcia FD, Rosa WC, Calheiro TP, Feitosa SC, Dal Forno GM, Zanatta N, Martins MA, Frizzo CP. Efficient approach for regioselective synthesis of new trifluoromethyl-substituted spirotetracyclic isoxazolines and isoxazoles. J Fluor Chem 2017. [DOI: 10.1016/j.jfluchem.2017.02.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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14
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Pairas GN, Perperopoulou F, Tsoungas PG, Varvounis G. The Isoxazole Ring and ItsN-Oxide: A Privileged Core Structure in Neuropsychiatric Therapeutics. ChemMedChem 2017; 12:408-419. [DOI: 10.1002/cmdc.201700023] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 02/13/2017] [Indexed: 01/23/2023]
Affiliation(s)
- George N. Pairas
- Laboratory of Medicinal Chemistry, Department of Pharmacy; University of Patras; 265 04 Patras Greece
| | - Fereniki Perperopoulou
- Laboratory of Enzyme Technology, Department of Biotechnology; Agricultural University of Athens; 75 Iera Odos St. 118 55 Athens Greece
| | - Petros G. Tsoungas
- Laboratory of Biochemistry; Hellenic Pasteur Institute; 127 Vas. Sofias Ave. 115 21 Athens Greece
| | - George Varvounis
- Section of Organic Chemistry and Biochemistry, Department of Chemistry; University of Ioannina; 451 10 Ioannina Greece
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15
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Synthesis of New (E)-2-(1 H-Indole-3-ylcarbonyl)-3-heteroaryl-acrylonitriles via Microwave-Assisted Knoevenagel Condensation. J CHEM-NY 2017. [DOI: 10.1155/2017/8418930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Given the broad spectrum of biological uses of heteroaryl-acrylonitrile derivatives, it is necessary to find simple methods to synthesize and diversify this family of compounds. We report a stereoselective synthesis of a series of new (E)-2-(1H-indole-3-ylcarbonyl)-3-heteroaryl-acrylonitriles (3a–3i) obtained from 3-(cyanoacetyl)indole and heteroaryl-aldehydes under microwave-assisted Knoevenagel reaction at 300 W of potency and 100°C. The desired derivatives (3a–3i) were obtained with variable yields (30–94%) and time reactions (8–90 min). All the heteroaryl-acrylonitriles were characterized by physicoanalytical techniques such IR, 1H, 13C NMR, and electrospray mass spectrometry.
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16
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Rodríguez YA, Gutiérrez M, Ramírez D, Alzate-Morales J, Bernal CC, Güiza FM, Romero Bohórquez AR. Novel N-allyl/propargyl tetrahydroquinolines: Synthesis via Three-component Cationic Imino Diels-Alder Reaction, Binding Prediction, and Evaluation as Cholinesterase Inhibitors. Chem Biol Drug Des 2016; 88:498-510. [PMID: 27085663 PMCID: PMC5053295 DOI: 10.1111/cbdd.12773] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Revised: 03/10/2016] [Accepted: 04/05/2016] [Indexed: 01/11/2023]
Abstract
New N‐allyl/propargyl 4‐substituted 1,2,3,4‐tetrahydroquinolines derivatives were efficiently synthesized using acid‐catalyzed three components cationic imino Diels–Alder reaction (70–95%). All compounds were tested in vitro as dual acetylcholinesterase and butyryl‐cholinesterase inhibitors and their potential binding modes, and affinity, were predicted by molecular docking and binding free energy calculations (∆G) respectively. The compound 4af (IC50 = 72 μm) presented the most effective inhibition against acetylcholinesterase despite its poor selectivity (SI = 2), while the best inhibitory activity on butyryl‐cholinesterase was exhibited by compound 4ae (IC50 = 25.58 μm) with considerable selectivity (SI = 0.15). Molecular docking studies indicated that the most active compounds fit in the reported acetylcholinesterase and butyryl‐cholinesterase active sites. Moreover, our computational data indicated a high correlation between the calculated ∆G and the experimental activity values in both targets.
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Affiliation(s)
- Yeray A Rodríguez
- Laboratorio Síntesis Orgánica, Instituto de Química de Recursos Naturales, Universidad de Talca, Casilla 747, Talca, 3460000, Chile
| | - Margarita Gutiérrez
- Laboratorio Síntesis Orgánica, Instituto de Química de Recursos Naturales, Universidad de Talca, Casilla 747, Talca, 3460000, Chile.
| | - David Ramírez
- Centro de Bioinformática y Simulación Molecular, Universidad de Talca, 2 Norte 685, Casilla 721, Talca, 3460000, Chile
| | - Jans Alzate-Morales
- Centro de Bioinformática y Simulación Molecular, Universidad de Talca, 2 Norte 685, Casilla 721, Talca, 3460000, Chile
| | - Cristian C Bernal
- Grupo de Investigación de Compuestos Orgánicos de Interés Medicinal (CODEIM), Parque Tecnológico Guatiguará, Universidad Industrial de Santander, A.A. 678, Piedecuesta, Colombia
| | - Fausto M Güiza
- Grupo de Investigación de Compuestos Orgánicos de Interés Medicinal (CODEIM), Parque Tecnológico Guatiguará, Universidad Industrial de Santander, A.A. 678, Piedecuesta, Colombia
| | - Arnold R Romero Bohórquez
- Grupo de Investigación de Compuestos Orgánicos de Interés Medicinal (CODEIM), Parque Tecnológico Guatiguará, Universidad Industrial de Santander, A.A. 678, Piedecuesta, Colombia.
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17
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Kupka T, Wieczorek PP. Theoretical and experimental NMR studies on muscimol from fly agaric mushroom (Amanita muscaria). SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2016; 153:216-225. [PMID: 26312739 DOI: 10.1016/j.saa.2015.08.026] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Revised: 07/13/2015] [Accepted: 08/12/2015] [Indexed: 06/04/2023]
Abstract
In this article we report results of combined theoretical and experimental NMR studies on muscimol, the bioactive alkaloid from fly agaric mushroom (Amanita muscaria). The assignment of (1)H and (13)C NMR spectra of muscimol in DMSO-d6 was supported by additional two-dimensional heteronuclear correlated spectra (2D NMR) and gauge independent atomic orbital (GIAO) NMR calculations using density functional theory (DFT). The effect of solvent in theoretical calculations was included via polarized continuum model (PCM) and the hybrid three-parameter B3LYP density functional in combination with 6-311++G(3df,2pd) basis set enabled calculation of reliable structures of non-ionized (neutral) molecule and its NH and zwitterionic forms in the gas phase, chloroform, DMSO and water. GIAO NMR calculations, using equilibrium and rovibrationally averaged geometry, at B3LYP/6-31G* and B3LYP/aug-cc-pVTZ-J levels of theory provided muscimol nuclear magnetic shieldings. The theoretical proton and carbon chemical shifts were critically compared with experimental NMR spectra measured in DMSO. Our results provide useful information on its structure in solution. We believe that such data could improve the understanding of basic features of muscimol at atomistic level and provide another tool in studies related to GABA analogs.
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Affiliation(s)
- Teobald Kupka
- Faculty of Chemistry, Opole University, Oleska 48, 45-052 Opole, Poland.
| | - Piotr P Wieczorek
- Faculty of Chemistry, Opole University, Oleska 48, 45-052 Opole, Poland.
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18
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Tu KN, Hirner JJ, Blum SA. Oxyboration with and without a Catalyst: Borylated Isoxazoles via B-O σ-Bond Addition. Org Lett 2016; 18:480-3. [PMID: 26771389 PMCID: PMC4763986 DOI: 10.1021/acs.orglett.5b03530] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
Herein
we report an oxyboration reaction with activated substrates
that employs B–O σ bond additions to C–C π
bonds to form borylated isoxazoles, which are potential building blocks
for drug discovery. Although this reaction can be effectively catalyzed
by gold, it is the first example of uncatalyzed oxyboration of C–C
π bonds by B–O σ bonds—and only the second
example that is catalyzed. This oxyboration reaction is tolerant of
groups incompatible with alternative lithiation/borylation and palladium-catalyzed
C–H activation/borylation technologies for the synthesis of
borylated isoxazoles.
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Affiliation(s)
- Kim N Tu
- Department of Chemistry, University of California-Irvine , Irvine, California 92697-2025, United States
| | - Joshua J Hirner
- Department of Chemistry, University of California-Irvine , Irvine, California 92697-2025, United States
| | - Suzanne A Blum
- Department of Chemistry, University of California-Irvine , Irvine, California 92697-2025, United States
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19
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Urdaneta N, Landaeta VR, Rodríguez-Lugo RE, Díaz C, Santiso-Quinones G, Quiroga J, Insuasty B. Synthesis and characterization of Cu(I) and Zn(II) complexes with new sulfur-bearing isoxazole- or pyrazole-based ligands. INORG CHEM COMMUN 2015. [DOI: 10.1016/j.inoche.2015.03.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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