- Multicomponent Catalytic Enantioselective Synthesis of Isoxazolidin-5-Ones
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We report herein a strategy to afford a multicomponent catalytic enantioselective synthesis of β-substituted isoxazolidin-5-ones via a KMC process promoted by a suited cupreine used as bifunctional organocatalyst. The hydroxamic acid component, with a ste
- Annibaletto, Julien,Martzel, Thomas,Levacher, Vincent,Oudeyer, Sylvain,Brière, Jean-Fran?ois
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supporting information
p. 4447 - 4451
(2021/08/09)
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- NUCLIDE LABELLED H-TETRAZINES AND USE THEREOF FOR PET AND SPECT PRETARGETED IMAGING AND RADIONUCLIDE THERAPY
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The present invention relates to novel tetrazine compounds for use in pretargeted in vivo imaging and in therapy and to the precursors of the tetrazine compounds. The compounds are suitable for use in click chemistry, i.e. reactions that join a targeting
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Page/Page column 31
(2021/11/20)
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- A Novel 18F-Labeled Radioligand for Positron Emission Tomography Imaging of 11β-Hydroxysteroid Dehydrogenase (11β-HSD1): Synthesis and Preliminary Evaluation in Nonhuman Primates
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11β-Hydroxysteroid dehydrogenase type 1 (11β-HSD1) catalyzes the conversion of cortisone to cortisol and controls a key pathway in the regulation of stress. Studies have implicated 11β-HSD1 in metabolic diseases including type 2 diabetes and obesity, as well as stress-related disorders and neurodegenerative diseases, such as depression and Alzheimer's disease (AD). We have previously developed [11C]AS2471907 as a PET radiotracer to image 11β-HSD1 in the brain of nonhuman primates and humans. However, the radiosynthesis of [11C]AS2471907 was unreliable and low-yielding. Here, we report the development of the 18F-labeled version [18F]AS2471907, including the synthesis of two iodonium ylide precursors and the optimization of 18F-radiosynthesis. Preliminary PET experiments, composed of a baseline scan of [18F]AS2471907 and a blocking scan with the reversible 11β-HSD1 inhibitor ASP3662 (0.3 mg/kg), was also conducted in a rhesus monkey to verify the pharmacokinetics of [18F]AS2471907 and its specific binding in the brain. The iodonium ylide precursors were prepared in a seven-step synthetic route with an optimized overall yield of 7sim;2%. [18F]AS2471907 was synthesized in good radiochemical purity, with the ortho regioisomer of iodonium ylide providing greater radiochemical yield as compared with the para regioisomer. In monkey brain, [18F]AS2471907 displayed high uptake and heterogeneous distribution, while administration of the 11β-HSD1 inhibitor ASP3662 significantly reduced radiotracer uptake, thus demonstrating the binding specificity of [18F]AS2471907. Given the longer half-life of F-18 and feasibility for central production and distribution, [18F]AS2471907 holds great promise to be a valuable PET radiotracer to image 11β-HSD1 in the brain.
- Baum, Evan,Zhang, Wenjie,Li, Songye,Cai, Zhengxin,Holden, Daniel,Huang, Yiyun
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p. 2450 - 2458
(2019/03/08)
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- Nucleophilic18F-Labeling of Spirocyclic Iodonium Ylide or Boronic Pinacol Ester Precursors: Advantages and Disadvantages
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The field of labeling electron-rich aryl compounds with nucleophilic [18F]fluoride has recently expanded with radiofluorination strategies that apply boronic esters or spirocyclic iodonium ylides as precursors. Herein, we present a direct compa
- Petersen, Ida Nymann,Kristensen, Jesper Langgaard,Herth, Matthias Manfred
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supporting information
p. 453 - 458
(2017/02/05)
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- IODINE(III)-MEDIATED RADIOFLUORINATION
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A process for fluorination of aromatic compounds employing iodonium ylides and applicable to radiofluorination using 18F is described. Processes, intermediates, reagents and radiolabelled compounds are described.
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- Is RK-682 a promiscuous enzyme inhibitor? Synthesis and in vitro evaluation of protein tyrosine phosphatase inhibition of racemic RK-682 and analogues
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RK-682 (1) is a natural product known to selectively inhibit protein tyrosine phosphatases (PTPases) and is used commercially as a positive control for phosphatase inhibition in in vitro assays. Protein phosphatases are involved in several human diseases including diabetes, cancer and inflammation, and are considered important targets for pharmaceutical development. Here we report the synthesis of racemic RK-682 (rac-1) and a focused set of compounds, including racemic analogues of 1, dihydropyranones and C-acylated Meldrum's acid derivatives, the later obtained in one synthetic step from commercially available starting material. We further characterized the behavior of some representative compounds in aqueous solution and evaluated their in vitro PTPase binding and inhibition. Our data reveal that rac-1 and some derivatives are able to form large aggregates in solution, in which the aggregation capacity is dependent on the acyl side chain size. However, compound aggregation per se is not able to promote PTPase inhibition. Our data disclose a novel family of PTPase inhibitors (C-acylated Meldrum's acid derivatives) and that rac-1 and derivatives with an exposed latent negatively charged substructure (e.g.: the tetronic acid core of 1) can bind to the PTPase binding site, as well promiscuously to protein surfaces. The combined capacity of compounds to bind to proteins together with their intrinsic capacity to aggregate in solution seems essential to promote enzyme aggregation and thus, its inhibition. We also observed that divalent cations, such as magnesium frequently used in enzyme buffer solutions, can deplete the inhibitory activity of rac-1, thus influencing the enzyme inhibition experiment. Overall, these data help to characterize the mechanism of PTPase inhibition by rac-1 and derivatives, revealing that enzyme inhibition is not solely dependent on compound binding to the PTPase catalytic site as generally accepted in the literature. In addition, our results point to promiscuous mechanisms that influence significantly the in vitro evaluation of enzyme inhibition by rac-1. Therefore, we recommend caution when using natural or synthetic RK-682 (1) as an internal control for evaluating PTPase inhibition and selectivity, since many events can modulate the apparent enzyme inhibition.
- Carneiro, Vania M.T.,Trivella, Daniela B.B.,Scorsato, Valéria,Beraldo, Viviane L.,Dias, Mariana P.,Sobreira, Tiago J.P.,Aparicio, Ricardo,Pilli, Ronaldo A.
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- Dioxocyclohexane carboxylic acid phenyl amide derivatives for modulating voltage-gated potassium channels and pharmaceutical compositions containing the same
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Dioxocyclohexane carboxylic acid phenyl amide derivatives of Formula (I) or a tautomer or a pharmaceutically acceptable salt thereof or both, and pharmaceutical compositions containing the same are provided: [image] The dioxocyclohexane carboxylic acid phenyl amide derivatives are useful for treating a variety of conditions associated with the abnormal modulation of one or more Kv1.1 voltage-gated potassium channels.
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Page/Page column 14-15
(2010/02/15)
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- Reaction of N,N'-di(methoxycarbonyl)-p-benzoquinonediimine with Meldrum's acid and its analogs
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Reactions of 2,2-dimethyl-4,6-dioxo-1,3-dioxane (Meldrum's acid), 2,2-tetramethylene-4,6-dioxo-1,3-dioxane and 2,2-pentamethylene-4,6-dioxo-1,3- dioxane in the presence of MeONa gave rise instead of expectable products of Michael 1,4-addition the correspo
- Velikorodov
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p. 690 - 692
(2007/10/03)
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- Spectrophotometric determination and kinetic studies of condensation of aromatic aldehydes with 7,9-dioxo-6,10-dioxaspiro[4.5]decane
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The condensation reaction rates of 7,9-dioxo-6,10-dioxaspiro[4.5]decane with aromatic aldehydes in chloroform in the presence of piperidine has been investigated spectrophotometrically at 25-50°C. The reaction follows overall second order kinetics, first
- Medien,Zahran,Erian
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p. 139 - 145
(2007/10/03)
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