- Synthesis of short and long-wavelength functionalised probes: amino acids' labelling and photophysical studies
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Fluorescent labelling of α-amino acids at their N or C terminals in the main and lateral chains at short and long wavelengths was carried out in different ways. The N-[3-(naphthalen-1-ylamino)propanoyl]amino acid methyl esters synthesised showed strong fluorescence in the visible region (~415 nm) of the electromagnetic spectrum. Condensation of these compounds with 5-diethylamino-2-nitrosophenol or 5-ethylamino-4-methyl-2-nitrosophenol produced the benzo[a]phenoxazine derivatives, with maximum emission wavelengths shifted to values higher than 644 nm. The synthesis of novel functionalised 5,9-diaminobenzo[a]phenoxazinium salts, by reaction of 5-ethylamino-4-methyl-2-nitrosophenol and N-substituted 1-naphthylamine and their use in the covalent labelling of the N or C terminals of valine, produced derivatives with long-wavelength emissions (644-653 nm). Photophysical studies using the synthesised compounds both in different solvents and in controlled pH were undertaken. Preliminary evaluation of photostability of the cationic polycyclic heterocycles in ethanol and water at physiological pH was also performed.
- Frade, Vania H.J.,Barros, Síria A.,Moura, Jo?o C.V.P.,Coutinho, Paulo J.G.,Gon?alves, M. Sameiro T.
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- Transketolase A from E. coli Significantly Suppresses Protein Glycation by Glycolaldehyde and Glyoxal in Vitro
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Short-chained carbonyl species such as glycolaldehyde and its oxidized pendant glyoxal are highly reactive Maillard agents, leading to the formation of protein modifications. These advanced glycation endproducts have gained considerable interest as they have been linked to various pathologies in vivo. The ability of transketolase to use glycolaldehyde as a substrate suggested the possibility to modulate carbonyl-driven Maillard reactions. Model incubations with recombinant transketolase A from Escherichia coli in the presence of bovine serum albumin and glycolaldehyde indeed led to a decrease in glycolaldehyde concentrations paralleled by the enzymatic conversion to erythrulose. As a result, reversibly protein-bound glycolaldehyde and the major final endproduct N6-carboxymethyl lysine were significantly reduced by approximately 50%, respectively. Glycolaldehyde is easily oxidized to glyoxal in the presence of amines and oxygen. In the presence of transketolase, the lower amounts of glycolaldehyde therefore also strongly suppressed the formation of glyoxal specific arginine modifications, measured as 5-(2-imino-5-oxo-1-imidazolidinyl)norvaline after acid hydrolysis.
- Klaus, Alexander,Pfirrmann, Thorsten,Glomb, Marcus A.
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- 3,6-DISUBSTITUTED-2-PYRIDINALDOXIME SCAFFOLDS
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The present invention relates to a compound of formula (I), or one of its pharmaceutically acceptable salts: wherein R1, R2 and -X-Y- have specific definitions. It also relates to the use of such a compound as reactivator of acetylcholinesterase for treating organophosphorous nerve agents poisoning; and to a process for preparing it.
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Paragraph 0095; 0118-0120
(2020/08/27)
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- Green synthesis of N-(2-hydroxyethyl)anilines by the selective alkylation reaction in H2O
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Based on our previous work, a safer and more sustainable protocol for the synthesis of N-(2-Hydroxyethyl)anilines has been developed. The synthesis included the selective alkylation reaction of aniline with 2-chloroethanol in H2O, eliminating the need for any catalysts and solvents during synthesis. Comparing with our previous work, the salient features of this methodology are eco-friendliness, economic benefit, and the ease of obtaining target compounds. The selective alkylation reaction in H2O is amenable to scale-up for the synthesis of N-(2-Hydroxyethyl)anilines.
- Guo, Hui,Hao, Jia,Sun, Tingting,Wang, Zuoyao,Cao, Jian,Zhang, Guobao
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- N-Arylazetidines: Preparation through Anionic Ring Closure
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We report herein an efficient synthesis of diversely substituted N-aryl-2-cyanoazetidines based on an anionic ring-closure reaction. These compounds can be prepared from β-amino alcohols in enantiomerically pure form through a three-step sequence involving (i) copper-catalyzed N-arylation, (ii) N-cyanomethylation of the secondary aniline, and (iii) one-pot mesylation followed by ring closure induced by a base. This high-yielding sequence gives access to azetidines with a predictable and adjustable substitution pattern and also with predictable diastereoselectivity. These compounds are susceptible to multiple further derivatizations through Suzuki coupling or nitrile transformation, thus appearing as valuable new scaffolds for medicinal chemistry. Their rigid shape, featuring an almost planar N-arylamine and a planar four-membered ring, was revealed by both AM1 calculations and X-ray crystallography.
- Quinodoz, Pierre,Drouillat, Bruno,Wright, Karen,Marrot, Jéro?me,Couty, Fran?ois
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p. 2899 - 2910
(2016/04/26)
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- BmimOAc ionic liquid: A highly efficient catalyst for synthesis of 3-aryl-2-oxazolidinones by direct condensation of 2-(arylamino) alcohols with diethyl carbonate
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An efficient convenient procedure for the synthesis of 3-aryl-2-oxazolidinones from 2-(arylamino) alcohols and diethyl carbonate (DEC) catalyzed by ionic liquids is described. The effects of reaction time, amount of catalyst and temperature were investigated. Excellent yields of products were obtained under the optimized reaction conditions, when using BmimOAc as a catalyst. An intermediate ethyl 2-(phenyl amino) ethyl carbonate was isolated and characterized. 1H NMR spectroscopy and DFT calculations indicated that BmimOAc cooperatively activate the substrates through hydrogen bonding with its anion and cation sites. According to these results, a possible reaction mechanism was discussed.
- Elageed, Elnazeer H.M.,Wang, Binshen,Zhang, Yongya,Wu, Shi,Gao, Guohua
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p. 271 - 277
(2015/09/01)
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- Heterocyclization Approach for Electrooxidative Coupling of Functional Primary Alkylamines with Aromatics
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A new approach for electrooxidative coupling of aromatic compounds and primary alkylamines bearing a functional group such as a hydroxyl group and an amino group was developed. The key to the success of the transformation is heterocyclization of functional primary alkylamines. Treatment of primary alkylamines bearing a functional group with nitriles or their equivalents gives the corresponding heterocycles. The electrochemical oxidation of aromatic substrates in the presence of the heterocycles followed by chemical reaction under nonoxidative conditions gave the desired coupling products.
- Morofuji, Tatsuya,Shimizu, Akihiro,Yoshida, Jun-Ichi
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supporting information
p. 9816 - 9819
(2015/08/24)
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- Green and efficient protocol for the synthesis of N-(2-hydroxyethyl)anilines by the alkylation reaction in ionic liquid
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A green and efficient protocol for the synthesis of N-(2-hydroxyethyl)anilines by the selective alkylation reaction in ionic liquid [BMIM]BF4 (1-butyl-3-methylimidazolium tetrafluoroborate) has been developed, eliminating the need for toxic and expensive catalysts and volatile organic solvents. The effects of the amount of ionic liquid, temperature, time, and substrate structure on the reaction were investigated. The conversion and selectivity of N-(2-hydroxyethyl)anilines obtained in ionic liquid [BMIM]BF4 are significantly increased in comparison to those traditional methods. Furthermore, the ionic liquid could be easily separated and reused at least five times. It provided a simple and efficient alternative way for the industrial synthesis of N-(2-hydroxyethyl)anilines.
- Guo, Hui,Zhuang, Yuwei,Cao, Jian,Zhang, Guobao
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p. 3368 - 3374
(2014/12/10)
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- SELECTIVE HDAC INHIBITORS
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This disclosure is related to compounds having the structure (I) wherein Ar1, Ar2, R1 - R6, Z, m, n, o, and p are defined herein. This disclosure also relates to pharmaceutical compositions comprising the above compounds and methods for their use.
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Page/Page column 95
(2011/12/04)
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