Bibliografias temáticas / Amino-carboxylic

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Literatura científica selecionada sobre o tema "Amino-carboxylic"

Autor: Grafiati
Publicado: 1 de abril de 2023

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Artigos de revistas sobre o assunto "Amino-carboxylic"

1

Siutkina, Alena I., Ramiz R. Makhmudov e Daria A. Shipilovskikh. "Synthesis and analgesic activity evaluation of derivatives of 2-[(1,4-dioxo-1-amino-4-arylbutyl-2-en-2-yl)amino]-4,5,6,7-tetrahydrobenzo[<i>b</i>]thiophene-3-carboxylic acid". Chimica Techno Acta 8, n.º 4 (22 de novembro de 2021): 20218404. http://dx.doi.org/10.15826/chimtech.2021.8.4.04.

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The synthesis of new derivatives of 2-[(1,4-dioxo-1-amino-4-arylbutyl-2-en-2-yl)amino]-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxylic acid is described. Starting 2-{[5-aryl-2-oxofuran-3(2H)-ylidene]amino}thiophene-3-carboxylic acids were obtained by intramolecular cyclisation of substituted 4-aryl-4-oxo-2-thienylaminobut-2-enoic acids in acetic anhydride. New derivatives of 2-[(1,4-dioxo-1-amino-4-arylbutyl-2-en-2-yl)amino]-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxylic acids were obtained via decyclization reaction of 2-{[5-aryl-2-oxofuran-3(2H)-ylidene]amino}thiophene-3-carboxylic acids. The structure of the compounds obtained was confirmed by the 1H and 13C NMR spectroscopy, IR spectrometry and elemental analysis methods. Analgesic activity of new compounds has been studied by the “hot plate” method on outbred white mice of both sexes with intraperitoneal injection. It was found that derivatives of 2-[(1,4-dioxo-1-amino-4-arylbutyl-2-en-2-yl)amino]-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxylic acid possess analgesic effect exceeding the effect of the comparison drug metamizole.
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Кудрявский, Дмитрий Леонович, Елена Константиновна Фомина, Людмила Юльевна Тычинская, Евгений Доминикович Скаковский e Светлана Евгеньевна Богушевич. "NMR spectroscopy of Cu(II) complexes with acrylamide and sodium acrylate copolymer and ω-amino acids". Journal of the Belarusian State University. Chemistry, n.º 1 (12 de abril de 2021): 85–98. http://dx.doi.org/10.33581/2520-257x-2021-1-85-98.

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Macromolecular complexes of acrylamide and sodium acrylate copolymer with microelements, including Cu(II), may form at preparation of crop protection and stimulation compositions, where the copolymer serves as an adhesive, water-retaining and film-forming agent. Preparations for crop production may also contain amino acids that protect plants under stressful conditions (cold, dry, etc.). Carboxylic groups of copolymer, carboxylic and amino groups of amino acids may be involved in mixed Cu(II) ions complexes formation. Number of methylene groups separating carboxylic and amino group of amino acids affects its ability to form a stable chelate cycle and, therefore, ligand composition of mixed Cu(II) ions complexes with acrylamide and sodium acrylate copolymer and amino acid. This work is aimed at determining the ligand composition of mixed macromolecular Cu(II) ion complexes with acrylamide and sodium acrylate copolymer and ω-amino acids (β-alanine, γ-aminobutyric acid, ε-aminocaproic acid). 13C and 1H NMR spectroscopy was used to clarify complexes composition. A complex where carboxylic groups of amino acids are ligands has been found to form in aqueous solutions of Cu(II) ions and ω-amino acid (β-alanine, γ-aminobutyric acid, ε-aminocaproic acid) at molar ratio of Cu(II) ions – amino acid equal to 1 : 6. A chelate complex where both carboxylic and amino groups of β-alanine are involved in coordination has been discovered to form in the solution containing Cu(II) ions, β-alanine, as well as acrylamide and sodium acrylate copolymer at molar ratio of Cu(II) – β-alanine – copolymer COO− equal to 1 : 6 : 30. Carboxylic groups of copolymer participate in complex formation as well. Carboxylic groups of both amino acids and the copolymer have been shown to participate in complex formation in aqueous solutions containing Cu(II) ions, either γ-aminobutyric or ε-aminokaproic acid and also acrylamide and sodium acrylate copolymer.
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Lynch, Daniel E., Tariq Latif, Graham Smith, Karl A. Byriel, Colin H. L. Kennard e Simon Parsons. "Molecular Cocrystals of Carboxylic Acids. XXXI Adducts of 2-Aminopyrimidine and 3-Amino-1,2,4-triazole with Heterocyclic Carboxylic Acids". Australian Journal of Chemistry 51, n.º 5 (1998): 403. http://dx.doi.org/10.1071/c97201.

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A series of molecular adducts of 2-aminopyrimidine and 3-amino-1,2,4-triazole with heterocyclic carboxylic acids have been prepared and characterized by using X-ray powder diffraction and in four cases by single-crystal X-ray diffraction methods. These four compounds are the (1 : 1) adducts of 2-aminopyrimidine with indole-3-acetic acid [(C4H5N3)(C10H9NO2)], N-methylpyrrole-2-carboxylic acid [(C4H5N3)(C6H7NO2)] and thiophen-2-carboxylic acid [(C4H5N3)(C5H4O2S)], and the (1 : 1) adduct of 3-amino-1,2,4-triazole with thiophen-2-carboxylic acid [(C2H4N4)(C5H4O2S)]. Other compounds described are the (1 : 1) adducts of 3-amino-1,2,4-triazole with indole-3-acetic acid and N-methylpyrrole-2-carboxylic acid.
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Shahmohammadi, Sayeh, Ferenc Fülöp e Enikő Forró. "Efficient Synthesis of New Fluorinated β-Amino Acid Enantiomers through Lipase-Catalyzed Hydrolysis". Molecules 25, n.º 24 (17 de dezembro de 2020): 5990. http://dx.doi.org/10.3390/molecules25245990.

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An efficient and novel enzymatic method has been developed for the synthesis of β-fluorophenyl-substituted β-amino acid enantiomers through lipase PSIM (Burkholderia cepasia) catalyzed hydrolysis of racemic β-amino carboxylic ester hydrochloride salts 3a–e in iPr2O at 45 °C in the presence of Et3N and H2O. Adequate analytical methods were developed for the enantio-separation of racemic β-amino carboxylic ester hydrochlorides 3a–e and β-amino acids 2a–e. Preparative-scale resolutions furnished unreacted amino esters (R)-4a–e and product amino acids (S)-5a–e with excellent ee values (≥99%) and good chemical yields (>48%).
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Wermuth, Urs D., Ian D. Jenkins, Raymond C. Bott, Karl A. Byriel e Graham Smith. "Some Stereochemical Aspects of the Strecker Synthesis and the Bucherer - Bergs Reaction". Australian Journal of Chemistry 57, n.º 5 (2004): 461. http://dx.doi.org/10.1071/ch03202.

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Both the Strecker and Bucherer–Bergs reactions convert the norbornane keto ester methyl bicyclo[2.2.1]hept-6-one-2-endo-carboxylate into the lactam 6-endo-aminobicyclo[2.2.1]heptane-2-endo-carboxylic acid-γ-lactam-6-exo-carboxylic acid. This lactam is unusually stable and cannot be hydrolyzed to the corresponding amino acid. The stereochemistry in the Strecker reaction, in which the amino group is endo, is contrary to that expected from literature precedent. The stereochemistry in the Bucherer–Bergs reaction, in which the amino group is also endo, has been confirmed by X-ray crystallographic analysis of the intermediate spirohydantoin (±)-bicyclo[2.2.1]heptane-2-endo-carboxylic acid-6-spiro-5′-hydantoin.
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Lynch, Daniel E., Laura J. Nicholls, Graham Smith, Karl A. Byriel e Colin H. L. Kennard. "Molecular co-crystals of 2-aminothiazole derivatives". Acta Crystallographica Section B Structural Science 55, n.º 5 (1 de outubro de 1999): 758–66. http://dx.doi.org/10.1107/s0108768199003146.

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A series of molecular adducts of 2-aminothiazole derivatives – 2-aminothiazole, 2-amino-2-thiazoline and 2-aminobenzothiazole with the carboxylic-acid-substituted heterocyclics indole-2-carboxylic acid, N-methylpyrrole-2-carboxylic acid and thiophene-2-carboxylic acid – have been prepared and characterized using X-ray powder diffraction and in five cases by single-crystal X-ray diffraction methods. These five compounds are the adducts of 2-amino-2-thiazolium with indole-2-carboxylate [(C3H7N2S)+(C9H6NO2)−], and N-methylpyrrole-2-carboxylate [(C3H7N2S)+-(C6H6NO2)−], 2-aminobenzothiazolium with indole-2-carboxylate [(C7H7N2S)+(C9H6NO2)−], N-methylpyrrole-2-carboxylate [(C7H7N2S)+(C6H6NO2)−] and thiophene-2-carboxylate [(C7H7N2S)+(C5H3O2S)−]. All complexes involve proton transfer, as indicated by IR spectroscopy, while the five crystal structures display similar hydrogen-bonding patterns with the dominant interaction being an R^2_2(8) graph set dimer association between carboxylate groups and the amine/heterocyclic nitrogen sites. Futhermore, in each case a subsiduary interaction between an amino proton and a carboxylate oxygen completes a linear hydrogen-bonded chain. In addition to this, the indole-2-carboxylate molecules in the adduct structure with 2-amino-2-thiazolium form associated dimers which add to the hydrogen-bonding network.
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Adams, Jerry L., Teng Man Chen e Brian W. Metcalf. "4-Amino-4,5-dihydrothiophene-2-carboxylic acid". Journal of Organic Chemistry 50, n.º 15 (julho de 1985): 2730–36. http://dx.doi.org/10.1021/jo00215a027.

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LI, JORGE P., TOBIAS O. YELLIN, CHARLES W. DEBROSSE e DRAKE S. EGGLESTON. "3-Amino-2-piperidinone-6-carboxylic acid". International Journal of Peptide and Protein Research 34, n.º 4 (12 de janeiro de 2009): 311–18. http://dx.doi.org/10.1111/j.1399-3011.1989.tb01580.x.

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Steinschneider, A., B. Valentine, M. I. Burgar e D. Fiat. "NMR of carboxylic-17O in amino acids". Magnetic Resonance in Chemistry 23, n.º 2 (fevereiro de 1985): 104–10. http://dx.doi.org/10.1002/mrc.1260230211.

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Moustafa, Moustafa Sherief, Saleh Mohammed Al-Mousawi, Maghraby Ali Selim, Ahmed Mohamed Mosallam e Mohamed Hilmy Elnagdi. "Organobase-catalyzed three-component reactions for the synthesis of 4H-2-aminopyrans, condensed pyrans and polysubstituted benzenes". Beilstein Journal of Organic Chemistry 10 (14 de janeiro de 2014): 141–49. http://dx.doi.org/10.3762/bjoc.10.11.

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Novel routes for the preparation of 2-amino-4H-pyran-3-carbonitrile 9, amino-arylbenzoic acid ester derivatives 13a,b, 2-aminotetrahydro-4H-chromene-3-carbonitrile 18, 3-amino-4-cyanotetrahydronaphthalene-2-carboxylic acid ester 26 and 4-amino-3,5-dicyanophthalic acid ester derivatives 37a–c were developed. The synthetic methods utilize one-pot reactions of acetylene carboxylic acid esters, α,β-unsaturated nitriles and/or active methylenenitriles in the presence of L-proline or DABCO. Plausible mechanisms are suggested for the formation of the products. Finally, these compounds were used for the efficient synthesis of 6-amino-5-cyanonicotinic acid ester derivatives 31a,b, ethyl 4-amino-5H-pyrano[2,3-d]pyrimidine-6-carboxylates 33a,b, 4-amino-6H-pyrrolo[3,4-g]quinazoline-9-carbonitrile 39, and 1,7-diamino-6-(N'-hydroxycarbamimidoyl)-3-oxo-5-phenyl-3H-isoindole-4-carboxylate (40).
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Mais fontes

Teses / dissertações sobre o assunto "Amino-carboxylic"

1

Dobson, Allison J. "X-ray diffraction investigations of quinoline and amino carboxylic acids /". The Ohio State University, 1998. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487949836206992.

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Badiani, Kamal. "Synthesis and evaluation of enzyme inhibitors based on amino- and cyclopropane carboxylic acids". Thesis, University of St Andrews, 1997. http://hdl.handle.net/10023/14052.

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The coenzyme B12-dependent enzyme, glutamate mutase (E. C. 5.4.99.1), catalyses the reversible carbon-skeleton rearrangement of (2S)-glutamic acid to (25.35)-3-methylaspartic acid. Glutamate mutase is the first enzyme on the mesaconate pathway. A variety of glutamate and 3-methylaspartate analogues (which also include isotopically labelled molecules), were synthesised as molecular probes of the enzyme. Synthesis of stereospecifically labelled 3-ethylaspartic acid: (2S,3S)-[3'-C2H3], and (2S,3S)-[C2H2C2H3]-ethylaspartic acids were constructed using appropriately labelled iodoethane. (2S,3S)-2-Bromo-3-methylsuccinic acid was synthesised via the diazotization of (2S,3S)-3-methylaspartic acid, in the presence of bromide ion. (2S)-Methylsuccinic acid was synthesised by the catalytic hydrogenation of (2S,3S)-2-bromo-3-methylsucdnic acid. Biological studies of the synthesised compounds (including the labelled isotopomers) displayed no activity against glutamate mutase. 3-Methylaspartate ammonia-lyase, the second enzyme in the mesaconate pathway, catalyses the deamination of (2S,3S)-3-methylaspartic acid to mesaconic acid. A range of 1-substituted cyclopropane 1,2-dicarboxylic acids were synthesised using short efficient routes and were found to be good to potent inhibitors of 3-methylaspartase. X-ray crystallographic studies have determined the absolute stereochemistry. The mode of action of the most potent inhibitor, (1S,2S)-1-methylcyclopropane 1,2-dicarboxylic acid (20 mumol dm-3), is consistent with it acting as a transition state analogue for the central substrate deamination reaction catalysed by the enzyme. beta-Amino acids are constituents of many biologically active peptides. A general procedure for the synthesis of alpha-substituted-beta-amino acids has been developed. The synthesis involves a Baylis-Hillman amine catalysed conversion of methyl acrylate, with an appropriate aldehyde, to give the alpha-(hydroxyalkyl) acrylate. Bromination and subsequent azide displacement furnishes the azido alkene, which is catalytically hydrogenated, to furnish the beta-amino ester.
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Marsh, Paul Robert. "3-Azido-tetrahydrofuran carboxylates as scaffolds for oligomers of β-amino-THF carboxylic acids". Thesis, University of Oxford, 2002. https://ora.ox.ac.uk/objects/uuid:749edfc8-8e18-4811-9247-8e29a3f54c7b.

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This thesis describes investigations into the synthesis and secondary structural properties of novel carbohydrate-derived peptidomimetics. The syntheses from diacetone-D-glucose of five diastereomeric 3-azido-tetrahydrofuran carboxylates are described. These highly functionalised β-amino acid equivalents are accessed via the diacetone-3-azido-3-deoxy sugars and 3-azido-3-deoxy-1,4-lactones. An acid-catalysed rearrangement results in the formation of the tetrahydrofuran ring with the protected amine functionality already in place in a position β- to the carboxylate group. Attempts to synthesise "carbopeptoids" via various oligomerisation strategies, including three novel approaches to oligomerisation, are delineated. The first approach attempted involves an iterative addition of a bicyclic lactone, which acts as the activated acid component, to the substrate containing an amine functionality. A new solid-phase oligomerisation strategy, whereby the coupling reagent is tethered to the polystyrene support and the substrates remain in solution, is described. The third attempted novel oligomerisation strategy involves activation by microwave irradiation, in the absence of coupling reagents. The conventional coupling using a carbodiimide coupling reagent proves to be a highly efficient means to access oligomers up to six residues in length, and is utilised for the synthesis of the homooligomers of four diastereomeric carbohydrate-derived β-amino acids. The prospect that the carbopeptoids may emulate the helical conformations reported for closely related 2-aminocyclopentanecarboxylic acid oligomers is investigated. Different methods of spectroscopic analysis of the tetrameric and hexameric oligomers are discussed. Circular dichroism spectroscopy provides a rapid diagnostic tool for the investigation of peptide bond orientations and forms the basis for a postulation on a possible stabilised hydrogen-bonding secondary structural conformation in two tetrameric species. Several nuclear magnetic resonance spectroscopic experiments are performed, enabling the assignment of each signal in the proton spectrum for a hexameric oligomer. However the resulting data does not provide sufficient evidence for a well-defined secondary structural motif, and so the potential conformational preference postulated on the basis of circular dichroism spectroscopy is not confirmed.
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Champion, Susan M. "Asymmetric synthesis of 2-amino carboxylic acids and the synthesis of novel phosphono-compounds". Thesis, University of Bristol, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.260485.

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Lundberg, Helena. "Group (IV) Metal-Catalyzed Direct Amidation : Synthesis and Mechanistic Considerations". Doctoral thesis, Stockholms universitet, Institutionen för organisk kemi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-116955.

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The amide unit constitutes the backbone of proteins, and it is present in a large number of pharmaceutically active molecules, polymeric materials such as nylon and Kevlar, as well as in food additives like aspartame. Amides are produced in enormous amounts every year, thus, environmentally friendly and selective methods for their formation are of great importance. This thesis deals with the direct formation of amides from non-activated carboxylic acids and amines with the aid of group (IV) metal complexes. Water is the only by-product of this environmentally benign process. This fact stands in contrast to the most common methods for amide formation to date, which involve the use of waste-intensive, expensive and often toxic coupling reagents. The catalytic protocols presented herein use titanium, zirconium and hafnium complexes under mild reaction conditions to produce amides in good to excellent yields. Furthermore, carbamates are demonstrated to be suitable sources of gaseous amines for the formation of primary and tertiary amides under catalytic conditions. In addition, preliminary results from on-going mechanistic investigations of the zirconium- and hafnium-catalyzed processes are presented.
Amidbindningen är en kemisk enhet som utgör ryggraden i proteiner, och som även återfinns i en stor mängd läkemedelsmolekyler, polymera material som nylon och Kevlar, samt i tillsatser i livsmedelsindustrin, exempelvis aspartam. Amider produceras i enorma mängder varje år, och det är av stor vikt att utveckla miljövänliga och selektiva metoder för deras framställning. Denna avhandling behandlar direkt amidering av icke-aktiverade karboxylsyror och aminer med hjälp av katalytiska mängder metallkomplex, baserade på titan, zirkonium och hafnium. Den enda biprodukten från denna amideringsreaktion är vatten. Jämfört med de metoder som generellt används idag för amidsyntes, så är de presenterade metoderna avsevärt mer miljövänliga med avseende på toxicitet hos reagensen såväl som på mängden avfall som genereras. Dessutom redovisas här en katalytisk metod för syntes av primära och tertiära amider genom att använda olika karbamat som källa till gasformiga aminer, vilka annars kan vara praktiskt svåra att arbeta med. Preliminära resultat från en pågående mekanistisk studie av de zirkonium- och hafnium-katalyserade processerna är också inkluderade.

At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 2: Accepted.

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Navin, V. "One-Pot Synthesis Of Chiral Disulfides & Diselenides From α-Amino Acids Mediated By Ammonium Tetrathiomolybdate In Water". Thesis, Indian Institute of Science, 2001. http://hdl.handle.net/2005/268.

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We have described herein a convenient one-pot synthesis of lisulfides/diselenides from a-amino acids mediated by ammonium etrathiomolybdate in water. (Figure 1) (Figure) Figure 1 Transformation of α-amino acids into the corresponding tiiocyanates/selenocyanates/disulfides/diselenides Halo-de-amination of a-amino acids using HBr/NaNCte followed by treatment with ammonium tetrathiomolybdate (NH4)2]VloS4 jLb provided a general route for the the one-pot synthesis of chiral a,a' bis (dithio) carboxylic acids (Figure 1, 2b). The yields were moderate, limited mainly the moderate conversion of a-amino acids into the corresponding chiral a-bromides. It was possible to synthesize the 2-thiocyanto carboxylic acids from the corresponding a-amino acids by a similar strategy. Thus diazotization in the presence of KSCN yielded in the chiral 2-thiocyanto carboxylic acids in moderate yields (Figure 1, 3). Thiocyanato-de-amination thus afforded the thiocyanates which when treated with JJD provided the chiral disulfides (Figure 1, 4a). We could thus synthesize both enantiomers of the disulfide from a single enantiomer of the starting a-amino acid. (Figure 1, 4a,4b) Using a similar strategy we have also demonstrated an efficient method for the synthesis of chiral selenocyanates starting from a-amino acids, using selenocyanate anion as the nucleophile (Figure 1, 5). It is possible to demonstrate a one-pot synthesis of chiral diselenides by reductive coupling of selenocyanates using JJb. (Figure 1, 6) (for figure see the pdf file)
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Hu, Zilun. "CONSTRAINED β–PROLINES: I. METHANOPYRROLIDINE β-AMINO ACIDS: SYNTHESIS AND CHARACTERIZATION OF NOVEL C6- SUBSTITUTED ANALOGUES AND PEPTIDE OLIGOMERS II. SYNTHESIS OF 2,2-DISUBSTITUTED PYRROLIDINE-3-CARBOXYLIC ACIDS". Diss., Temple University Libraries, 2015. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/339315.

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Chemistry
Ph.D.
In the study of structurally restricted cyclic β-amino acids and peptides, methanopyrrolidine-5-carboxylic acids (MetPyr-5-acids), or 5-syn-carboxy-2-azabicyclo[2.1.1] hexanes, and derivatives were investigated. MetPyr-5-acids are a series of highly conformationally constrained β-proline derivatives, which belong to a novel category of β-amino acids utilized as building blocks for the synthesis of β-peptides. These β-peptides lack the backbone hydrogen bonds necessary for folding in the usual manner. Substituents and functional groups in this ring system were envisioned to impact the folding properties and functionalities of the corresponding β-peptides. In the present study, the analogues of MetPyr-5-acids with C6- substitutions were prepared, and the folding properties of their peptides were explored. To introduce different functionalities at C6 in MetPyr-5-acids, 6-syn-hydroxymethyl substituted derivatives were synthesized and were used as key intermediates. In the synthesis of this core structure, the major steps in their preparation included the Michael addition of benzyloxymethyl allyl amine to 3-butynone, followed by UV light irradiation of the diene to afford 5-acetyl-6-benzyloxymethyl-2-azabicyclo[2.1.1]hexane. Haloform (Br2/NaOH) oxidation of the acetyl group leads to the 6-substituted MetPyr-5-acid. Resolution of the racemate was achieved either by resolving (±)-6-syn-benzyloxymethyl-MetPyr-5-acid via a classical crystallization resolution method using (S)-(-)-α-methylbenzylamine, or by chiral preparative HPLC separation of (±)-6-syn-benzyloxymethyl-MetPyr-5-acid methyl ester. The absolute stereochemistry was confirmed by X-ray crystallography of a derivative. Novel analogs with a range of functionalities incorporated at the C6 position in MetPyr-5-acid were synthesized from 6-syn-hydroxymethyl-MetPyr-5-acid methyl ester, and include hydrophilic groups such as hydroxyl, amino, methyl ether, and hydrophobic groups, such as substituted phenyl groups and triazole. From the protected C6-substituted analogs of MetPyr-5-acids, peptide oligomers of C6-benzyloxymethyl-2,4-methanopyrrolidine-b-amino acid were prepared up to the length of octomer in high yields. This series of oligomers were characterized by circular dichroism (CD) and indicated enhanced order of folding uniformity for the tetramer and up, with increasing ordered folding for longer oligomers. The octomer exhibited minimal solvent effects, and was stable with increasing temperature up to 80 °C. Analysis by NMR of the iso-butyric amide capped monomer indicated a mixture of cis/trans conformation favoring the cis conformation. This was slightly different from the C6 unsubstituted iso-butyric amide derivative, which favored the trans conformation. For the dipeptide, the C6-benzyloxymethyl substitution increased the percentage of cis conformation of the dipeptide amide bond, but the major peptide had the trans conformation. This demonstrated that C6 substitutions could shift the cis/trans equilibrium towards the cis conformation. Longer oligomers showed ordered secondary folding structure as demonstrated by the increase in ellipticity per amino acid unit, but was too complicated to be determined by NMR analysis. Both the CD patterns and molecular model calculation predicted that the longer oligomers (tetramer and above) favor the trans conformation. This preference was driven by the backbone dipole effect. II. SYNTHESIS OF 2,2-DISUBSTITUTED PYRROLIDINE-3-CARBOXYLIC ACIDS Due to the perceived steric influence of 2,2-disubstitution in the pyrrolidine-3-carboxylic acid, it is believed that the adjacent amide/peptide bonds should result in a trans amide bond conformation. Because of the difficulty in introducing disubstitution at the hindered C2 position, the synthesis of such derivatives has not been successful. For this reason a new method was introduced to prepare novel derivatives, at the N- and C- termini of protected 2,2-dimethyl pyrrolidine-3-carboxylic acid, i.e., benzyloxycarbonyl protected 2,2-dimethylpyrrolidine-3-carboxylate. This procedure included the Michael addition of 2-nitropropane to dimethyl fumarate, followed by ring closure of the amino ester derived from reduction of the nitro ester providing the pyrrolidinone. Reduction of the pyrrolidinone to the pyrrolidine with borane finished 2,2-dimethylpyrrolidine-3-carboxylate in moderate overall yield. A preliminary set of two amides, iso-butyric amide and 3,5-dichlorobenzamide of this 2,2-dimethylpyrrolidine-3-carboxylate, were also prepared. NMR analysis of this pyrrolidine derivative suggested the amide bonds adopted the trans conformation. It was concluded that steric bulk of the 2,2-disubstitution favorably influenced the trans amide conformation. This demonstrated that trans amide conformation control of a β-proline amide was possible.
Temple University--Theses
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Olszewski, Tomasz Krzysztof. "Original syntheses of new biomolecules : from imidazole and thiazole derivatives of α-aminophosphonic acids and γ-amino-α, β-dihydroxy carboxylic acid derivatives to disaccharide mimics". Montpellier 2, 2006. http://www.theses.fr/2006MON20017.

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Rocha, Sandra Carla. "Avaliação das perspectivas terapêuticas do ácido L-tiazolidina-4-carboxílico, um análogo de prolina, na infecção de camundongos pelo Trypanosoma cruzi". Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/42/42135/tde-16082011-160411/.

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Trypanosoma cruzi é dependente de prolina para diversos processos tal como metabolismo energético, invasão celular, diferenciação e resistência a estresse osmótico, metabólico e oxidativo. O ácido L-tiazolidina-4-carboxílico (T4C), um análogo estrutural da prolina, inibe competitivamente o transporte deste aminoácido em T. cruzi, e interage sinergicamente com fatores de estresse que ocorrem ao longo do seu ciclo de vida. Aqui nós avaliamos o efeito de T4C na infecção de camundongos pelo T. cruzi. Foi observada uma redução de 49% do pico parasitêmico de animais infectados e tratados com dose única de T4C (100 mg/Kg). A análise histológica e por PCR quantitativa de diferentes tecidos revelou uma redução significativa da carga parasitária apenas no intestino de animais tratados com T4C (100 ou 150 mg/Kg). Por outro lado, a dose única de 200 mg/Kg diminuiu o peso corporal e sobrevida de animais não infectados. O tratamento prolongado (10 mg/Kg dia) não reduziu a parasitemia, mas aumentou a sobrevida e diminuiu a carga parasitária no intestino. T4C não afetou a expressão gênica de IFN-g e IL-10 em qualquer um dos tecidos analisados (coração, baço, intestino). Em conclusão, T4C contribui em reduzir a virulência da infecção, mas é tóxico em doses que superem 150 mg/kg.
Trypanosoma cruzi is dependent on proline for a variety of processes such as energy metabolism, host cell invasion, differentiation and resistance to osmotic, metabolic and oxidative stress. L-thiazolidine-4-carboxylic acid (T4C), a proline structural analogue, inhibits the proline uptake and interacts with several stress factors that the parasite undergoes throughout its life cycle. Herein, we evaluated the T4C effects on mice infection by T. cruzi. It was observed a reduction of 49% of the parasitemia peak in infected mice that were treated with a unique dose of T4C (100 mg/Kg). Histological and quantitative PCR analysis of several tissues revealed a significant reduction of parasite load in the intestine (100 or 150 mg/kg). In the other hand, the unique dose of 200 mg/Kg reduced the body weight and survival of non-infected mice. A T4C prolonged treatment (10 mg/Kg day), did not diminish the parasitemia, but increased survival and reduced the parasite load in the intestine. T4C did not affect the gene expression of g-IFN and IL-10 in any of the organs analyzed (heart, spleen, intestine). In conclusion, T4C-treatment contributes to reduce the virulence of T. cruzi infection, but it was toxic in doses over 150 mg/kg.
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Bianco, Angelica. "Formation photoinduite du radical hydroxyle dans la phase aqueuse du nuage : impact sur les acides carboxyliques et les acides aminés". Thesis, Clermont-Ferrand 2, 2016. http://www.theses.fr/2016CLF22746/document.

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Les nuages représentent un milieu multiphasique complexe et réactif. Une grande partie de composés chimiques atmosphériques de la phase particulaire ou gazeuse se dissout dans les gouttelettes de nuage où peuvent subir des transformations chimiques, photochimiques et microbiologiques. L'eau de nuage a été échantillonnée à la station du puy de Dôme et caractérisée par des mesures physico-chimiques. La première partie de mon travail de thèse est focalisée sur la réactivité de l’eau du nuage. La formation d’espèces réactives, le radical hydroxyle, est étudiée par photolyse directe de sources inorganiques et photolyses nano-pulsée et sa vitesse de formation a été corrélée à la concentration de sources. Les propriétés spectroscopiques et la dégradation d'un composé modèle, l'acide tartronique, ont été étudiés. Les expériences faite par irradiation continue (photolyse directe et induite par le radical hydroxyle) et par photolyse pulsée ont permis de comprendre la réactivité de ce composé dans le milieu nuageux. La deuxième partie de mon travail est focalisée sur la caractérisation et la réactivité de la matière organique dans la phase aqueuse des nuages. La détection et la quantification de tryptophane par spectroscopie de fluorescence et l'étude de sa réactivité ainsi que la détection et quantification d‘acides aminés représente une partie importante de ce travail. Les acides aminés ont été détectés pour la première fois dans l'eau de nuage grâce à l'utilisation d'une méthode chromatographique de dérivation et détection par fluorescence. Ce travail à démontré que les acides aminés peuvent représenter entre 4 et 21 % de la concentration en carbone de la matière organique dissoute dans le nuage. La réactivité des acides aminés avec le radical hydroxyle a été comparée avec celle des acides carboxyliques et de la matière organique dissoute. Ce résultat montre clairement que le rôle des acides aminés comme piège de radicaux hydroxyles ne peut plus être négligé
Clouds represent a multiphase complex and reactive medium in which gases, liquid particles and aerosols are in continuous interaction. A large fraction of atmospheric chemical compounds present in the particulate and gaseous phases can be transferred to the cloud droplets where can undergo chemical, photochemical and microbiological transformations. Cloud waters were sampled at the puy de Dôme station. The first part of my PhD work is focused on the photoreactivity of cloud water. Formation of a reactive species such as hydroxyl radical, by direct photolysis of inorganic sources was investigated, as well as the correlation between the concentration of sources and the hydroxyl radical formation rate. The spectroscopic proprieties and fate of tartronic acid, were investigated under cloud water conditions. Moreover, photochemical experiments were performed using continuous irradiation (direct and hydroxyl radical mediated photolysis) and nanosecond flash photolysis in order to assess the reactivity of this compound in cloud aqueous phase. The second part of my work is centered on the characterization of organic matter in clouds. Two studies are presented: i) Detection and quantification of tryptophan by fluorescence spectroscopy and the assessment of its reactivity; ii) detection and quantification of amino acids. Amino acids are detected for the first time in cloud water using a derivatization method and this work show that they represent the 9% of the dissolved organic matter in cloud. Their reactivity with hydroxyl radical was compared to the reactivity of carboxylic acids and dissolved organic matter. These results clearly demonstrate that amino acids represent a major sink of hydroxyl radicals in cloud water
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Livros sobre o assunto "Amino-carboxylic"

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Sheu, Shwu-Meei. Characterization and purification of [̳t̳r̳i̳a̳n̳g̳l̳e̳]̳-pyrroline-5-carboxylic acid reductase in Schistosoma mansoni. 1985.

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Capítulos de livros sobre o assunto "Amino-carboxylic"

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Böning, Dieter, Michael I. Lindinger, Damian M. Bailey, Istvan Berczi, Kameljit Kalsi, José González-Alonso, David J. Dyck et al. "α-amino Carboxylic Acid". In Encyclopedia of Exercise Medicine in Health and Disease, 57. Berlin, Heidelberg: Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-540-29807-6_4001.

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Bährle-Rapp, Marina. "4-Amino-2-Nitrodiphenylamine-2′-Carboxylic Acid". In Springer Lexikon Kosmetik und Körperpflege, 30. Berlin, Heidelberg: Springer Berlin Heidelberg, 2007. http://dx.doi.org/10.1007/978-3-540-71095-0_497.

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Wang, Ruiyao, e Zhiping Zheng. "Rare Earth Complexes with Carboxylic Acids, Polyaminopolycarboxylic Acids, and Amino Acids". In Rare Earth Coordination Chemistry, 91–136. Chichester, UK: John Wiley & Sons, Ltd, 2010. http://dx.doi.org/10.1002/9780470824870.ch3.

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Tritt-Goc, J., e D. Fiat. "A Determination of the Dynamical Parameters in Amino Acids from Carboxylic- 17O NMR Linewidths Measurements". In 25th Congress Ampere on Magnetic Resonance and Related Phenomena, 584–85. Berlin, Heidelberg: Springer Berlin Heidelberg, 1990. http://dx.doi.org/10.1007/978-3-642-76072-3_307.

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Yunes, J. S., P. Rowell e N. W. Kerby. "Growth and Amino Acid Liberation by a Mutant Strain of Anabaena Variabilis Resistant to the Amino Acid Analogue Azetidine 2-Carboxylic Acid". In Nitrogen Fixation, 519–20. Dordrecht: Springer Netherlands, 1991. http://dx.doi.org/10.1007/978-94-011-3486-6_105.

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Van Der Straeten, Dominique, Luc Van Wiemeersch, Jozef Van Damme, Howard Goodman e Marc Van Montagu. "Purification and Amino-Acid Sequence Analysis of 1-Aminocyclopropane-1-Carboxylic Acid Synthase from Tomato Pericarp". In Biochemical and Physiological Aspects of Ethylene Production in Lower and Higher Plants, 93–100. Dordrecht: Springer Netherlands, 1989. http://dx.doi.org/10.1007/978-94-009-1271-7_11.

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González-Muñiz, R., M. J. Dominguez, M. T. García-López, I. Gómez-Monterrey e J. R. Harto. "An efficient synthesis of 8-amino-3-oxoindolizidine-2-carboxylic acid and derivatives as model peptidomimetics". In Peptides 1990, 366–67. Dordrecht: Springer Netherlands, 1991. http://dx.doi.org/10.1007/978-94-011-3034-9_153.

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Jeanmart, Stephane. "Amino Acids as Nonselective Herbicides". In Bioactive Carboxylic Compound Classes: Pharmaceuticals and Agrochemicals, 315–24. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2016. http://dx.doi.org/10.1002/9783527693931.ch23.

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Ishikawa, T. "From 5-Amino-2,6-dihydroxypyrimidine-4-carboxylic Acid". In Six-Membered Hetarenes with Two Identical Heteroatoms, 1. Georg Thieme Verlag KG, 2004. http://dx.doi.org/10.1055/sos-sd-016-01777.

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Galembeck, Fernando, Gabriela Alves Macedo e Yara Csordas. "Chemicals from Sugarcane". In Materials for a Sustainable Future, 246–78. The Royal Society of Chemistry, 2012. http://dx.doi.org/10.1039/bk9781849734073-00246.

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Sugarcane has been a source of many chemicals in Brazil since the early 1940s. The increase in sugarcane production associated with the growing global demand for food (sucrose) and fuel (ethanol) has, since the early 1970s, led to a steady decrease in production costs and transformed sugarcane into an environmentally benign and economically competitive alternative to oil. Sugarcane is already a competitive feedstock for the production of a host of chemicals, including thermoplastics, solvents, surfactants, esters, ethers, carboxylic acids, amino acids, polyelectrolytes, gums and cellulose. Recent work, especially in Brazil, has produced a large number of new possibilities and many companies are implementing these. This chapter describes many examples of current products derived from sugarcane and also discusses possible future developments in this area.
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Trabalhos de conferências sobre o assunto "Amino-carboxylic"

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De Kimpe, Norbert, Antonio Salgado, Annelies Eeckhaut e Johan Van der Eycken. "Enzyme-mediated synthesis of (1S)-1-amino-2,2-dimethylcyclopropane-1-carboxylic acid". In The 4th International Electronic Conference on Synthetic Organic Chemistry. Basel, Switzerland: MDPI, 2000. http://dx.doi.org/10.3390/ecsoc-4-01804.

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Uphoff, Andreas. "Formation and reactions of cluster ions from aromatic carboxylic acids together with amino acids and small peptides". In RESONANCE IONIZATION SPECTROSCOPY 2000: Laser Ionization and Applications Incorporating RIS; 10th International Symposium. AIP, 2001. http://dx.doi.org/10.1063/1.1405617.

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Maya, K., Lalita Rane, Tousief Irshad Ahmed, Mohammad Javed Ansari, Chandra Kumar Dixit e Rahul Kanaoujiya. "L-Cysteine Passivated Carbon Quantum Dots as Biosensor for early Stage Detection of Prostate Cancer". In International Conference on Recent Advancements in Biomedical Engineering. Switzerland: Trans Tech Publications Ltd, 2022. http://dx.doi.org/10.4028/p-x65kwp.

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Green synthesized surface passivated carbon dots for detection of Citrate as biomarker for prostate cancer. The carbon sources of CQDs are passivated with L-cysteine via a one-pot hydrothermal route. The quenching in emission intensity of the synthesized carbon dots (CQDs) is observed for Citrate samples. The hydroxyl and carboxylic functional groups of Citrate showed a binding affinity with amino and free carboxyl cysteine passivated over the surface of carbon dots. The CQDs showed a high sensitivity for detection of Citrate in a continuous range of 1.0 μM–500 μM. The CQDs showed good level of selectivity, repeatability, and stability for the detection of Citrate. We successfully detected the Citrate content for prostate cancer cells using an L-cysteine passivated carbon quantum dots various incubation durations. As a result, quenching in fluorescence intensity CQDs are noted to analyze extent of cancer cells in biological samples.
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Lara Orozco, Ricardo A., Ryosuke Okuno e Larry W. Lake. "Analytical Solutions for the Injection of Wettability Modifiers in Carbonate Reservoirs Based on a Reduced Surface Complexation Model". In SPE Annual Technical Conference and Exhibition. SPE, 2021. http://dx.doi.org/10.2118/206088-ms.

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Abstract The potential of tuned-composition waterflooding to enhance oil recovery from carbonate reservoirs has been widely investigated in the literature. The consensus is that wettability alteration occurs because of the electrostatic interactions between the carbonate rock surface and the potential determining ions, Ca2+, Mg2+, CO32−, and SO42−. Recently, glycine, the simplest amino acid, has also been investigated as a wettability modifier for carbonates that acts similarly as the sulfate ions in brine. The impact of wettability modifiers like glycine and calcite's potential determining ions has been described by surface complexation models (SCM) and the wetting-state of the rock has been related to change of the surface potential. However, determining the relevance of the geochemical reactions is obstructed by the complexity of the SCM. Moreover, the surface potential as a surrogate of the wetting-state of the rock does not correlate with the experimental results with glycine reported in the literature. The present research analyzed the results of single-phase displacement using a SCM for calcite to determine the important surface complexation reactions. Then, wettability alteration is modeled as a set of anion exchange reactions between wettability modifiers, like SO42− and Gly−, and adsorbed carboxylic acids. Finally, analytical solutions are presented for the coupled two-phase and multicomponent reactive-transport model with anion exchange reactions.
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Relatórios de organizações sobre o assunto "Amino-carboxylic"

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Pesis, Edna, e Mikal Saltveit. Postharvest Delay of Fruit Ripening by Metabolites of Anaerobic Respiration: Acetaldehyde and Ethanol. United States Department of Agriculture, outubro de 1995. http://dx.doi.org/10.32747/1995.7604923.bard.

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The use of pretreatments for 24 h prior to storage, under anaerobic condtions, or in the presence of the natural metabolic products, acetaldehyde (AA) and ethanol, to delay fruit ripening, was found to be effective with several climacteric fruits, among them avocado, mango, peach and tomato. The delay in ripening of avocado, peach and tomato was accompanied by inhibition of ethylene production and of fruit softening. The maintenance of fruit firmness was associated with a decrease in the activities of cell-wall-degrading enzymes, including endoglucanases (Cx), polygalacturonases (PG) and b-galactosidases. In peaches the AA- and N2-treated fruits were firmer after 3 weeks storage and contained higher amount of insoluble pectin than untreated controls. We showed that AA vapors are able to inhibit ripening, ethylene production and ethylene induction in the presence of 1-amino-cyclopropane-1-carboxylic acid (ADD) in avocado and mango tissue. Ethylene induced by ACC is taken as an indicator of ACC oxidase activity. ACC oxidase activity in AA-treated avocado fruit was much lower than in the untreated fruit. In carnation flowers very little ethylene was produced by ethanol-treated flowers, and the normal increases in ACC content and ACC oxidase activity were also suppressed. Using kinetic studies and inhibitors of alcohol dehydrogenase (ADH), we showed that AA, not ethanol, was the active molecule in inhibiting ripening of tomato fruit. Application of anaerobiosis or anaerobic metabolites was effective in reduction of chilling injury (CI) in various plant tissues. Pretreatment with a low-O2 atmosphere reduced CI symptoms in avocado; this effect was associated with higher content of the free sylfhydryl (SH) group, and induction of the detoxification enzymes, catalase and peroxidase. Application of AA maintained firmer and brighter pulp tissue (non-oxidative), which was associated with higher free SH content, lower ethylene and ACC oxidase activities, and higher activities of catalase and peroxidase. Ethanol was found to reduce CI in other plant tissue. In roots of 24-h-old germinated cucumber seeds, exposure to 0.4-M ethanol shock for 4 h reduced chilling-induced ion leakage. In cucumber cotyledons it appears that alcohols may reduce CI by inducing stomata closure. In cotyledon discs held in N2 at 10C for 1 day, there accumulated sufficient endogenously synthesized ethanol to confer tolerance to chilling at 2.5C for 5 days.
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