- Kinetics and mechanism of the condensation of pyridoxal hydrochloride with L-tryptophan and D-tryptophan, and the chemical transformation of their products
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The kinetics and mechanism of interaction between pyridoxal and L-tryptophan, D-tryptophan, and their derivatives are studied. It is found that condensation reactions proceed via three kinetically distinguishable stages: (1) the rapid intraplanar addition of the NH2 groups of the amino acids to pyridoxal with the formation of amino alcohols; (2) the rotational isomerism of amino alcohol fragments with their subsequent dehydration and the formation of a Schiff base with a specific configuration; (3) the abstraction of α-hydrogen in the product of condensation of pyridoxal with L-tryptophan, or the abstraction of СО2 in the product of condensation of pyridoxal with D-tryptophan with the formation of quinoid structures, hydrolysis of which results in the preparation of pyridoxamine and keto acid or pyridoxal and tryptamine, respectively. Schiff bases resistant to further chemical transformations are formed in the reaction with tryptophan methyl ester.
- Pishchugin,Tuleberdiev
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Read Online
- Catalytic Staudinger Reduction at Room Temperature
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We report an efficient catalytic Staudinger reduction at room temperature that enables the preparation of a structurally diverse set of amines from azides in excellent yields. The reaction is based on the use of catalytic amounts of triphenylphosphine as a phosphine source and diphenyldisiloxane as a reducing agent. Our catalytic Staudinger reduction exhibits a high chemoselectivity, as exemplified by reduction of azides over other common functionalities, including nitriles, alkenes, alkynes, esters, and ketones.
- Lenstra, Danny C.,Wolf, Joris J.,Mecinovi?, Jasmin
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p. 6536 - 6545
(2019/05/24)
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- Sustainable organophosphorus-catalysed Staudinger reduction
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A highly efficient and sustainable catalytic Staudinger reduction for the conversion of organic azides to amines in excellent yields has been developed. The reaction displays excellent functional group tolerance to functionalities that are otherwise prone to reduction, such as sulfones, esters, amides, ketones, nitriles, alkenes, and benzyl ethers. The green nature of the reaction is exemplified by the use of PMHS, CPME, and a lack of column chromatography.
- Lenstra, Danny C.,Lenting, Peter E.,Mecinovi?, Jasmin
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supporting information
p. 4418 - 4422
(2018/10/17)
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- Indolamide compound capable of selectively inhibiting gastric cancer cells
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The invention discloses an indolamide compound capable of selectively inhibiting gastric cancer cells. The compound is capable of inhibiting the gastric cancer cells, particularly MGC-803 (human gastric cancer cells) cell strains, therefore the compound can be used as medicines for the selectively treatment of gastric cancer and has better developing prospect.
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Paragraph 0024; 0025
(2018/10/19)
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- Cyclometalated beta-carboline ruthenium complex and preparation method and application thereof
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The invention relates to the technical field of antitumor drugs and concretely discloses a cyclometalated beta-carboline ruthenium complex and a preparation method and application thereof. The ruthenium complex takes 1-phenyl-9H-pyrido[3,4-b] indole as a main ligand, and takes 2,2-bipyridyl or 4,4-dimethyl-2,2 bipyridyl as an ancillary ligand. The ruthenium complex has a very excellent anti-tumor effect and has more excellent activity against liver cancer, breast cancer, lung cancer and cervical cancer cell lines than cis-platinum and similar polypyridine carboline ruthenium complexes.
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Page/Page column 7
(2017/07/23)
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- Rapid Conventional and Microwave-Assisted Decarboxylation of L-Histidine and Other Amino Acids via Organocatalysis with R-Carvone under Superheated Conditions
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This article reports a new methodology taking advantage of superheated chemistry via either microwave or conventional heating for the facile decarboxylation of alpha amino acids using the recoverable organocatalyst, R-carvone. The decarboxylation of amino acids is an important synthetic route to biologically active amines, and traditional methods of amino acid decarboxylation are time consuming (taking up to several days in the case of L-histidine), are narrow in scope, and make use of toxic catalysts. Decarboxylations of amino acids including L-histidine occur in just minutes while replacing toxic catalysts with green catalyst, spearmint oil. Yields are comparable to or exceed previous methods and purification of product ammonium chloride salts is aided by an isomerization reaction of residual catalyst to phenolic carvacrol. The method has been shown to be effective for the decarboxylations of a range of natural, synthetic, and protected amino acids.
- Jackson, Douglas M.,Ashley, Robert L.,Brownfield, Callan B.,Morrison, Daniel R.,Morrison, Richard W.
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p. 2691 - 2700
(2015/12/18)
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- METHOD FOR DECARBOXYLATION OF AMINO ACIDS VIA IMINE FORMATION
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The present application provides methods for decarboxylation of amino acids via imine formation with a catalyst under superheated conditions in either a microwave or oil bath.
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Page/Page column 0045; 0053; 0066; 0067
(2014/09/30)
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- Low-temperature deacylation of N-monosubstituted amides
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(Chemical Equation Presented) The (PhO)3P-Cl2 reagent, prepared in situ by titrating a solution of triphenyl phosphite with chlorine, is used to convert N-monosubstituted amides into their corresponding amines. The reaction, if compared to other traditional methods, shows the advantage of very mild conditions and low temperature (-30°C→rt).
- Spaggiari, Alberto,Blaszczak, Larry C.,Prati, Fabio
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p. 3885 - 3888
(2007/10/03)
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- Versatile Reagent for Reduction of Azides to Amines
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Triphenylphosphine (TPP) in refluxing methanol effectively reduces a variety of azides 1a-k to amines 2a-k in very good yields.
- Pal, Bikash,Jaisankar, Parasuraman,Giri, Venkatachalam S.
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p. 1317 - 1323
(2007/10/03)
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- N6-Substituted Adenosine Receptor Agonists. Synthesis and Pharmacological Activity as Potent Antinociceptive Agents
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Novel N6-(indol-3-yl)alkyl derivatives of adenosine were synthesized.The adenosine receptor affinity and the antinociceptive activity of these compounds were assessed in binding studies and the phenylbenzoquinone-induced writhing test.Most of these analogues exhibited a potent analgesic activity without side effects.Among them, compound 3c (UP 202-32) bound to A1 (Ki = 110 nM) and A2 (Ki = 350 nM) adenosine receptors in a specific manner since it did not interact with many other receptors, especially opioid binding sites.The antinociceptive activity in the phenylbenzoquinone assay (ED50 = 3.3 mg/kg po) was antagonized by 8-cyclopentyltheophylline, suggesting that an adenosinergic mechanism underlies the analgesic activity observed with this compound.The data obtained with these new N6-substituted adenosine receptor agonists emphasize the interest of such compounds in the treatment of pain.
- Guengoer, Timur,Malabre, Patrice,Teulon, Jean-Marie,Camborde, Francoise,Meignen, Joelle,et al.
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p. 4307 - 4316
(2007/10/02)
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- ALKALOIDS OF Nitraria schoberi. STRUCTURE OF NITRARAINE
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The dehydration of nitraraine leads to the formation of 1-(2',6'-dimethylbenzyl)-β-carboline, together with other products.Several isomeric 1-(dimethylbenzyl)-β-carbolines have been synthesized for comparison.The products of acylation, hydrogenation, and oxidation of the alkaloid nitraraine have been studied.The results obtained have shown its structure as (+/-)-16-hydroxymethylyohimb-16-ene.
- Ibragimov, A. A.,Yunusov, S. Yu.
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p. 502 - 509
(2007/10/02)
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- ALKALOIDS OF Nitraria komarovii. IV. TOTAL SYNTHESIS OF KOMAROVINE AND KOMAROVIDINE
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Two alkaloids of a new type - komarovine and komarovidine - have been isolated from the epigeal part of the Nitraria komarovii.Their structures - 3-(quinolin-8'-yl)-β-carboline and 3-(quinolin-8'-yl)-5,6-dihydro-β-carboline, respectively - have been established by synthesis.
- Tulyaganov, T. S.,Ibragimov, A. A.,Yunusov, S. Yu.
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p. 149 - 152
(2007/10/02)
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