Modification of Polyfluoro-Containing 3-(Ethoxycarbonyl)flavones by Biogenic Amines and Amino Acids

2018 ◽  
Vol 15 (5) ◽  
pp. 707-714 ◽  
Author(s):  
Konstantin V. Shcherbakov ◽  
Yanina V. Burgart ◽  
Victor I. Saloutin ◽  
Oleg N. Chupakhin
Keyword(s):  
Amino Acids ◽  
Biogenic Amines ◽  
Nucleophilic Aromatic Substitution ◽  
Gamma Aminobutyric Acid ◽  
Aromatic Substitution ◽  
Substitution Product ◽  
Reaction Conditions ◽  
Pyrone Ring ◽  
Beta Alanine ◽  
Ir Spectroscopic

Aim and Objective: The objective of our work was to study the peculiarities of transformations of fluorine-containing flavone-3-carboxylates with N-nucleophiles, including biogenic amines and amino acids. Materials and Methods: 6,7,8-Trifluoro and 5,6,7,8-tetrafluoroflavone-3-carboxylates were involved in interactions with a number of N-nucleophiles, such as pyrrolidine, morpholine, proline, arginine, gammaaminobutyric acid, beta-alanine, histamine, dopamine and amantadine under different reaction conditions. All synthesized compounds were characterized by NMR 1H, 19F, (NMR 13C for some compounds) and IR spectroscopic data, and elemental analysis. Results: 3-(Ethoxycarbonyl)polyfluoroflavones react with morpholine, pyrrolidine and L-proline to form 7- monosubstituted flavone-3-carboxylates. For the reactions of tetrafluoroflavone with pyrrolidine and morpholine, the formation of 5,7-disubstituted products is also possible. Interaction with gamma-aminobutyric acid leads to the 4-{[3-ethoxy-2-(2-hydroxypolyfluorobenzoyl)-3-oxo-1-phenylprop-1-enyl]amino}butanoic acids as a result of the pyrone ring opening. In reactions with dopamine, histamine, L-arginine and β-alanine, polyfluoroflavone-3-carboxylates underwent a chromone-coumarin rearrangement. 3-(Ethoxycarbonyl)tetrafluoroflavone forms with amantadine the nucleophilic aromatic substitution product, while trifluoro-substituted analog gives the chromone-coumarin rearrangement product. Conclusion: This work showed possibilities of chemical modification of polyfluorinated flavones in the reactions with amines depending on the structure of the nucleophilic reagent. Synthesized compounds are of interest for biological testing.

Purification of Antihemophilic Factor (Factor VIII) by Amino Acid Precipitation*

1964 ◽  
Vol 11 (01) ◽  
pp. 064-074 ◽  
Author(s):  
Robert H Wagner ◽  
William D McLester ◽  
Marion Smith ◽  
K. M Brinkhous
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Factor Viii ◽  
Plasma Protein ◽  
Acid Precipitation ◽  
Aminobutyric Acid ◽  
Gamma Aminobutyric Acid ◽  
Specific Procedure ◽  
Beta Alanine ◽  
Antihemophilic Factor

Summary1. The use of several amino acids, glycine, alpha-aminobutyric acid, alanine, beta-alanine, and gamma-aminobutyric acid, as plasma protein precipitants is described.2. A specific procedure is detailed for the preparation of canine antihemophilic factor (AHF, Factor VIII) in which glycine, beta-alanine, and gammaaminobutyric acid serve as the protein precipitants.3. Preliminary results are reported for the precipitation of bovine and human AHF with amino acids.

Deuterated Aryl Alkyl Ethers Synthesis via Nucleophilic Etherification of Aryl Alkyl Ethers and Thioethers with Deuterated Alcohols

Synlett ◽  
2019 ◽  
Vol 30 (15) ◽  
pp. 1805-1809
Author(s):  
Shuai Li ◽  
Xia Wang ◽  
Xin-Ge Yang ◽  
Gui-Quan Yu ◽  
Xue-Qiang Wang
Keyword(s):  
Transition Metal ◽  
Nucleophilic Aromatic Substitution ◽  
Aromatic Substitution ◽  
Mechanistic Studies ◽  
Reaction Conditions ◽  
Metal Free ◽  
Wide Range ◽  
Alkyl Ethers

A transition-metal-free etherification protocol that is capable of synthesizing deuterated ethers is described. A wide range of aryl alkyl ethers and thioethers were suitable for this transformation owing to the mild reaction conditions. Besides, a series of sterically bulky deuterated alcohols were successfully incorporated into cyano-substituted arenes. The results of mechanistic studies suggested this reaction might take place via nucleophilic aromatic substitution pathway.

Volume-regulatory amino acid transport in erythrocytes of the little skate, Raja erinacea

1993 ◽  
Vol 265 (1) ◽  
pp. R173-R179 ◽  
Author(s):  
J. K. Haynes ◽  
L. Goldstein
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Transport ◽  
Amino Acid Uptake ◽  
Disulfonic Acid ◽  
Acid Uptake ◽  
Gamma Aminobutyric Acid ◽  
Acid Transport ◽  
Beta Alanine ◽  
Volume Activation

Skate erythrocytes swell in a hypotonic medium and then reduce their volume mainly by releasing the beta-amino acids taurine and beta-alanine. Although these amino acids exhibit a net efflux, Na(+)-independent influx is also increased. Both the reduction in cell volume and increase in amino acid transport are inhibited by several inhibitors of band 3-mediated anion transport, including 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS) [L. Goldstein and S. R. Brill, Am. J. Physiol. 260 (Regulatory Integrative Comp. Physiol. 29): R1014-R1020, 1991]. The objective of the present investigation was to further characterize the mechanism of volume-activated amino acid transport. Na(+)-independent amino acid uptake was studied because of the ease in controlling amino acid concentrations. Na(+)-independent taurine uptake was observed to be linear over a range of 0.1-15 mM and was not inhibited by 10 mM beta-alanine, suggesting that the transporter may be a channel rather than a carrier. The uptake of a variety of amino acids was examined to characterize the size of the putative channel. Glycine, beta-alanine, taurine, proline, gamma-aminobutyric acid (GABA), and threonine exhibited volume-activated transport that was DIDS inhibited, whereas aspartic acid, leucine, methionine, and ornithine were not transported. On the basis of the size of these amino acids, it appears that molecules containing eight or fewer major atoms and having a molecular mass of < 125-131 Da are transported during volume activation but larger molecules are not. We estimate the size of the channel to be 5.7-6.3 A in diameter.

scholarly journals Nucleophilic Aromatic Substitution Reactions under Aqueous, Mild Conditions Using Polymeric Additive HPMC

2021 ◽  
Author(s):  
Niginia Borlinghaus ◽  
Tharique N. Ansari ◽  
Leon Hendrik H. Braje ◽  
Deborah Ogulu ◽  
Sachin Handa ◽  
...  
Keyword(s):  
Hydroxypropyl Methylcellulose ◽  
Nucleophilic Aromatic Substitution ◽  
Aromatic Substitution ◽  
Substitution Reactions ◽  
Reaction Conditions ◽  
Polymeric Additive ◽  
Mild Conditions

The use of the inexpensive, benign, and sustainable polymer, hydroxypropyl methylcellulose (HPMC), in water enables nucleophilic aromatic subsitution (SNAr) reactions between various nucleophiles and electrophiles. The mild reaction conditions facilitate...

Reconfigurable system for automated optimization of diverse chemical reactions

Science ◽  
2018 ◽  
Vol 361 (6408) ◽  
pp. 1220-1225 ◽  
Author(s):  
Anne-Catherine Bédard ◽  
Andrea Adamo ◽  
Kosi C. Aroh ◽  
M. Grace Russell ◽  
Aaron A. Bedermann ◽  
...  
Keyword(s):  
Chemical Synthesis ◽  
High Performance ◽  
Smartphone Application ◽  
Nucleophilic Aromatic Substitution ◽  
Aromatic Substitution ◽  
Reaction Conditions ◽  
Unit Operations ◽  
Electronic File ◽  
Automated Optimization ◽  
Error Optimization

Chemical synthesis generally requires labor-intensive, sometimes tedious trial-and-error optimization of reaction conditions. Here, we describe a plug-and-play, continuous-flow chemical synthesis system that mitigates this challenge with an integrated combination of hardware, software, and analytics. The system software controls the user-selected reagents and unit operations (reactors and separators), processes reaction analytics (high-performance liquid chromatography, mass spectrometry, vibrational spectroscopy), and conducts automated optimizations. The capabilities of this system are demonstrated in high-yielding implementations of C-C and C-N cross-coupling, olefination, reductive amination, nucleophilic aromatic substitution (SNAr), photoredox catalysis, and a multistep sequence. The graphical user interface enables users to initiate optimizations, monitor progress remotely, and analyze results. Subsequent users of an optimized procedure need only download an electronic file, comparable to a smartphone application, to implement the protocol on their own apparatus.

Sign in / Sign up

Export Citation Format

Share Document