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Uporedno FTIR spektroskposko ispitivanje N-H···O i N-H···π vodonične veze odabranih N-supstituisanih amida / Comparative FTIR spectroscopic investigation of N-H···O and N-H···π hydrogen bonding of selected N-substituted amides···Jović Branislav 14 January 2011 (has links)
<p>U ovom radu korišcen je spektroskopski, teorijski i hemometrijski pristup<br />proucavanju N-HO i N-H··· vodonicne veze koja se uspostavlja izmedu<br />amidnog protona i etarskog kiseonika tj aromaticnog sistema. U ovom radu<br />odredeni su parametri N-HO i N-H vodonicne veze za šesnaest Nsupstituisanih<br />amida sa tetrahidrofuranom i toluenom. Vecina ispitivanih amida do<br />sada nije bila izucavana sa stanovišta vodonicne veze. Uspostavljene su korelacije<br />izmedu spektorsopskih i teorijskih parametara. Izvršeno je poredenje medu<br />osobinama vodonicno vezanih kompleksa za razlicite amide kao proton donore.<br />Svih 32 ispitivanih vodonicno vezanih kompleksa okarakterisano je<br />hemometrijskim metodama: Klaster analizom i analizom glavne komponente, na<br />osnovu spektroskopskih, teorijskih i Taftovih parametara</p> / <p> In this PhD thesis, N-H×××O and N-H··· hydrogen bond beetwen the amide<br /> proton with ether oxygen and aromatic system has been investigated using the<br /> spectroscopic and theoretical approach. The study included sixteen N-substituted<br /> amides (formamides, acetamides, caproamides and benzamides) as well as<br /> tetrahydrofuran and toluene. The possibility of using chemometric methods was<br /> investigated in order to characterise N-H...O and N-H··· hydrgen bonded<br /> complexes. Hierarchial clustering and Principal Component Analysis (PCA) have<br /> been applied on infrared spectroscopic, PM3 theoretical and Taft parameters of 32 Nsubstituted<br /> amide complexes with tetrahydrofuran and toluene</p>
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Total synthesis of β-aminomethyl C-glycosides and their quinoyl amidesGremyachinskiy, Dmitriy Y. 01 January 2002 (has links) (PDF)
Aminomethyl C-glycosides are of pharmaceutical interest as potential therapeutic agents against HIV, viral and bacterial infections, cancer, and metabolic disorders, e.g. diabetes. Their synthesis is an important chemical problem. In this work, Prince-type cyclizations were performed with different Lewis acids to select optimal conditions, for high yield syntheses of a series of 4-chloro-2-phtalimidomethyl-6methyltetrahydropyrans 3,4 ( a–f ) and 4-chloro-2,6-bis(phtalimido-methyl)-tetrahydropyrans 3,4 ( g–i ), and similar bicyclic compounds 9,10 ( a,b ), potential precursors of C-oligosaccharides. An influence of reagent size and nucleophilicity on the reaction outcome was observed and was interpreted in terms of intermediate complex formations in the cationic mechanism. Optimized eliminations of hydrogen halide from 3,4 by 1,8-diaazobicyclo[5.4.0]undec-7-ene (DBU) in presence of LiCl gave a mixture of 2,6-anhydro-1,3,4,5,7-pentadeoxy-1-phtalimido-D,L-erythrohept-3-enitol and 2,6-anhydro1,3,4,5,7-pentadeoxy-1-phtalimido-D,L-erythrohept-4-enitol 5b, 6b in 79% combined yield. Epoxidation of 5b, 6b with urea-hydrogen peroxide complex and trifluoroacetic anhydride followed by treatment with aqueous trifluoroacetic acid gave a mixture of two dihydroxy-2-methyl-6-phtalimidomethyl tetrahydropyrans 15 and 16 with an overall yield of 74%. Cis-dihydroxylation of 5b, 6b with OsO 4 /NMO afforded two other dihydroxy-2-methylphthalimido tetrahydropyrans, 17 and 18 . The regioisomeric protected aminomethyl C-glycosides were separated, and were characterized to produce four racemates of aminomethyl C-glycopyranosides in high yields. These primary amines were amidated with chiral quinic acid lactone in the minimal amount of dimethylacetamide to produce four separable diastereomeric mixtures of C-pseudodisaccharides, for a total of eight diastereomers. Diastereomer 37a (or b ) was purified by crystallization and its conformation and structure was established by NMR methods. Diastereomers of compound 35 were derivatized and separated as O-acetyl derivatives and their structure was established by NMR. It was also found that allyl transfer occurred between acetal and homoallylic alcohol during the cyclization step. A new method for the synthesis of homoallylic alcohols from acetals was developed on the basis of this observation. Homoallylic alcohols, 1-phthalimido-4-penten-2-ol 1 β, 1-phenyl-4-pentene-2-ol 7 and 1-benzyloxy-4-penten-2-ol 8 were synthesized by this new method with yields of 71%, 61% and 40% respectively. This method allows the synthesis of homoallylic alcohols from unstable aldehydes. It could be optimized further, on the basis of a proposed reaction mechanism.
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Synthèse efficace d'hétérocycles azotés par activation d'amides engendrée par l'anhydride trifluorométhanesulfoniqueRégnier, Sophie 08 1900 (has links)
Les hétérocycles azotés sont d’une importance considérable dans le domaine pharmaceutique. En effet, ces composés se retrouvent dans de nombreuses structures bioactives brevetées dans les dernières années. Malgré l’utilité de ces motifs, leur synthèse nécessite souvent plusieurs étapes ou encore l’utilisation de matériaux de départ fonctionnalisés. Le présent mémoire décrit de nouvelles méthodologies pour accéder à ces structures de façon douce, chimiosélective et efficace par l’activation d’amides avec l’anhydride trifluorométhanesulfonique.
Dans un premier temps, une méthode en deux étapes pour accéder aux 3-aminoindazoles à partir des amides aromatiques correspondants a été développée. La séquence comprend l’activation de l’amide, suivie de l’addition d’une hydrazine protégée pour former un intermédiaire de type amino hydrazone. Cet intermédiaire peut ensuite être cyclisé dans une réaction de type amination de liens C-H en présence d’un catalyseur de palladium pour former le 3-aminoindazole désiré. Plusieurs 3-aminoindazoles ont été ainsi obtenus dans des rendements modérés à bons.
Ensuite, une nouvelle méthodologie pour la synthèse des 3-amino imidazo[1,2-a]pyridines a été étudiée. Des amides contenant un motif 2-aminopyridine ont été traités avec l’anhydride trifluorométhanesulfonique afin d’obtenir l’hétérocycle désiré dans d’excellents rendements. Les produits ainsi obtenus ont pu être davantage fonctionnalisés en utilisant des réactions d’arylation de liens C-H catalysées par des composés de ruthénium et de palladium. / Nitrogen-containing heterocycles are of considerable importance in the pharmaceutical area. These types of compounds are indeed found in numerous bioactive structures patented in the last few years. Although these motives are useful, their synthesis often necessitates multiple steps or the use of highly functionalized starting materials. The present thesis describes new methodologies to access these synthetically challenging structures in a mild, chemoselective and step-economic fashion by amide activation using trifluoromethanesulfonic anhydride.
First, a two-step method to access 3-aminoindazoles from the corresponding aromatic amide has been developed. The sequence includes a one-pot trifluoromethanesulfonic anhydride-mediated amide activation to form the corresponding iminium trifluoromethanesulfonate, followed by the addition of a protected hydrazide to access the amino hydrazone intermediate. This intermediate can then undergo cyclization through a palladium-catalyzed C-H amination reaction to afford the desired 3-aminoindazole. Various 3-aminoindazoles could be obtained in moderate to good yields.
Moreover, a new methodology for the synthesis of 3-amino imidazo[1,2-a]pyridines was developed. 2-Aminopyridine-containing amides were treated with trifluoromethanesulfonic anhydride to afford the desired heterocycles in good to excellent yields. The products thus obtained could then be further functionalized using ruthenium and palladium catalyzed C-H arylation reactions.
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Síntese, atividades biológicas e estudo de relação estrutura-atividade de piperamidas / Synthesis, biological activities and structure-activity relationship study of piperamidesFokoue, Harold Hilarion 15 January 2015 (has links)
As estruturas e propriedades biológicas das amidas piplartina e a piperina, isoladas respectivamente de Piper tuberculatum e P. nigrum, inspiraram a síntese de 89 derivados e 7 esters estruturalmente relacionadas. As preparações envolveram metodologias tradicionais e os compostos purificados tiveram suas estruturas caracterizadas por análises espectroscópicas e espectrométricas. Os estudos de fragmentação por IE e IES indicaram a clivagem preferencial da ligação N-CO no caso das cinamamidas, dienamidas e cinamimidas. Estudos computacionais envolvendo afinidade protônica e energias de ligação confirmaram a fragmentação preferencial da ligação amídica para as amidas. A citotoxicidade de 89 substâncias foi avaliada contra três células leucêmicas (K562, Nalm6 e Raji) e a partir dos valores de IC50 foram realizados estudos de relação estrutura-atividade (SAR). As linhagens K562 e a Nalm6 foram a mais resistente e vulnerável, respectivamente, e as amidas piplartina (1a), N-Ciclohexil-N-(ciclohexilcarbamoil)-3-(3,4,5-trimetoxifenil)propanamida (1n), e (E)-N,N-dibutil-3-(3,4-dimetoxifenil)acrilamida (13h) foram as mais ativas com IC50 de 0,34 µM; 0,84 µM e 1,88 µM contra K562 e (E)-N-ciclohexil-N-(ciclohexilcarbamoil)-3-(3,4-dimetoxifenil)acrylamida (13i) com IC50 de 0,98 µM contra Nalm6. A avaliação de atividade leishmanicida de 18 substâncias não se mostrou promissora. As abordagens qualitativas e quantitativas foram feitas baseadas nos descritores moleculares gerados pelo programa VolSurf+. A partir de métodos quimiométricos tais com PLS, algoritmo genético, árvores de decisão foi possível gerar modelos para correlacionar às propriedades moleculares com a atividade biológica. As propriedades de absorção, distribuição, metabolismo e excreção e os equilíbrios entres as regiões hidrofílicas e hidrofóbicas foram importantes para atividade citotóxica. O estudo de ancoragem molecular mostrou que as amidas (E)-N,N-dibutil-3-(3,4,5-trimetoxifenil)acrilamida (1l), 1n, (E)-3-(4-clorofenil)-N-ciclohexil-N-(ciclohexilcarbamoil)acrilamida (5a), 13h e 13i podem atuar como inibidores das histonas desacetilases particularmente HDAC4 e HDAC8. / The structures and biological properties of the amides piplartine and piperine isolated from Piper tuberculatum and P. nigrum respectively, inspired the synthesis of derivatives 89 and 7 esters structurally related. Their preparations were achieved using classical procedures and the purified amides were submitted to spectroscopic and spectrometric characterization. The study of fragmentation process by EI and ESI suggested the preferential cleavage of the N-CO bond of cinnamamides, dienamides and cinnamimides. The cytotoxicity of 89 compounds was evaluated against three leukemic cells (K562, Nalm6 and Raji) and based on IC50 values the structure-activity relationship (SAR) was performed. While the K562 and Nalm6 cells were the more resistant and more sensitive, respectively, the amides piplartine (1a), N-cyclohexyl-N-(ciclohexylcarbamoyl)-3-(3,4,5-trimethoxyphenyl)propanamide (1n) and (E)-N,N-dibutyl-3-(3,4-dimethoxyphenyl)acrylamide (13h) were in general the most active with IC50 of 0.34 µM, 0.84 µM and 1.88 µM against K562 and (E)-N-cyclohexyl-N-(ciclohexylcarbamoyl)-3-(3,4-dimethoxyphenyl)acrylamide (13i) with IC50 of 0.98 µM against Nalm6. The evaluation of leishmanicidal activity of 18 substances was also performed but was not promising. Qualitative and quantitative approaches were made based on molecular descriptors generated by VolSurf+ program. The chemometric methods such as PLS, genetic algorithm, decision trees generated models to correlate molecular properties with the biological activity. The absorption, distribution, metabolism and excretion properties and a balance between hydrophilic and hydrophobic moieties of the amides were important for an optimized activity. The molecular docking revealed that amides such as (E)-N,N-dibutyl-3-(3,4,5-trimethoxyphenyl)acrylamide (1l), 1n, (E)-3-(4-chlorophenyl)-N-cyclohexil-N-(cyclohexylcarbamoyl)acrylamide (5a), 13h and 13i have potential to act as possible inhibitors of histone deacetylase proteins particularly HDAC4 and HDAC8.
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Vers des peptoïdes fonctionnalisables à forme contrôléeCaumes, Cécile 28 October 2011 (has links)
Les peptoïdes sont une classe de peptidomimétiques pour lesquels les chaînes latérales de chaque résidu sont déplacées du carbone α sur l'azote d'amide adjacent. Le travail présenté dans ce document s'intéresse à l'étude et à l'utilisation de plateformes moléculaires de géométrie contrôlée de type β- et α,β-peptoïdes alternés. Une nouvelle méthode de synthèse "submonomer" en solution des différentes familles de peptoïdes a tout d'abord été mise au point. Elle permet de s'affranchir des purifications intermédiaires par chromatographie, grâce à l'utilisation d'amines primaires volatiles et de solvants permettant des précipitations sélectives, et ainsi d'accéder rapidement à des tétrapeptoïdes simples. Sur ce type de composés, la possibilité d'introduire de la diversité chimique par des post-modifications sur les chaînes latérales a été étudiée. Une plateforme β-peptoïde modèle pouvant présenter trois pharmacophores différents a été obtenue grâce à des ligations orthogonales sur les chaînes latérales par Cycloaddition 1,3-dipolaire catalysée au cuivre entre un alcyne et un azoture (CuAAC), couplage thiol-ène photochimique (TEC) et alkylation d'amine tertiaire. Une méthode efficace d'accès à des glycoclusters a également été développée : elle fait intervenir la ligation multivalente de 1-thiosucres non protégés sur des plateformes peptoïdes portant des chaînes latérales allyles grâce à la réaction de TEC photochimique. Dans un deuxième temps, une étude sur le contrôle l'isomérie cis / trans, corollaire du lien amide tertiaire présent dans les peptoïdes, est présentée. Elle a permis d'observer qu'un groupement triazolium sur la chaîne latérale permet de sélectionner de façon très efficace la géométrie cis grâce à des interactions électroniques. Le groupement tert-butyle a une influence similaire grâce à des effets stériques. La dernière partie décrit la synthèse d'analogues de la Somatostatine (hormone humaine impliquée dans la régulation de nombreuses fonctions physiologiques) possédant un squelette β-peptoïde en vue d'étude pharmacologique. / Peptoids are a class of peptidomimetics in which the side chains of each residue are moved from the α-carbon to the adjacent amide nitrogen. The work presented in this document focuses on the study and use of β-peptoid and α,β-alternating peptoid molecular scaffolds with controlled geometry. Firstly, a new method for solution-phase synthesis of peptoids was optimised. This method derives from the submonomer synthesis of peptoids and allows suppression of intermediate chromatography purifications thanks to the use of volatile primary amines and solvents allowing selective precipitations. It gives rapid access to simple tetrapetoids on which the potential of side chains post-modifications was investigated. A functionalised β-peptoid scaffold was decorated through orthogonal ligations on side chains using the Copper-catalysed Alkyne-Azide Cycloaddition (CuAAC), thiol-ene coupling (TEC) and tertiary amine alkylation reactions. An efficient method allowing access to glycoclusters was also developed : it consists in multivalent ligation on allyl fonctionalised peptoid scaffolds with unprotected 1-thiosugars using the photochemical TEC reaction. Secondly, a study was conduced on the control of the subsequent cis / trans isomerisation of tertiary amide linkage present in peptoids. It allowed us to observe that a triazolium side chain induces efficient selection of the cis geometry due to electronic interactions. The tert-butyl group has a similar effect due to steric effects. The last part of the document describes the synthesis of somatostatin (human hormone involved in the regulation of numerous physiological functions) analogs possessing α,β-peptoid scaffold with the aim of pharmacological studies.
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Chemistry Of Thio And Seleno Metallates In Organic SynthesisSaravanan, V 06 1900 (has links)
Thio metallates are known for many years for their utility in many processes. They have been established as versatile reagents in organic synthesis. However the heavier metal chalcogenides, though known for many years, have been ignored for a long time. In this thesis the results of the development of tetraethylammonium tetraselenotungstate [EttN]2Wse4 1 as a new class of selenium transfer reagent have been described. The thesis also deals with the chemistry of benzyltriethylammonium tetrathiomolybdate, [BnEt3N]2MoS4,2 in the synthesis of diselenides and thio esters.
The thesis entitled "Chemistry of Thio and Seleno Metallates in Organic Synthesis" is divided into four Chapters.
Chapter 1
In this chapter a detailed studies of alkylation of tetraethylammonium tetraselenotungstate (EuN)2WSe4,1 with a variety of alkyl halides, benzylic halides and acyl halides to yield the corresponding diselenides in excellent yields are described.
(structural Formula)
Scheme 1
Various carbohydrate-derived diselenides were also prepared by treating the sugar bromides with tetraethylammonium tetraselenotungstate 1 (Scheme 2). An attempt was made to synthesize seleno lactones from co- bromo acyl halides. This reaction mainly furnished the corresponding diacyl diselenides (Scheme 3).
The reaction of 1 with aryldiazonium tetrafluoroborates led to the formation of corresponding diselenides or mono selenides depending on the substitution on the aromatic ring (Scheme 4).
(structural formula)
Scheme 2
(structural formula)
Scheme 3
(structural formula)
Scheme 4
Chapter 2
In this chapter a general methodology for the formation of the diselenide bond has been extended to the synthesis of a number of redox- switched crown ethers of various ring size using the reagents tetraethylammonium tetraselenotungstate (Et4N)2WSe4 t 1 and benzyltriethylammonium tetrathiomolybdate, [BnEt3NJ2MoS4,2 (Scheme 5).
(structural formula)
Scheme 5
The association constants for the binding of silver and potassium ions with the diselena crown ethers were determined. This methodology is very useful for obtaining selenacrown ethers under very mild conditions and also without using high dilution conditions.
Chapter 3
In this chapter a general methodology for the facile conversion of amides and lactams to the corresponding seleno amides and selenolactams is described. A number of amides and lactams were converted into their selenocarbonyl derivatives in excellent yield via the formation of Vilsmeier intermediates followed by treatment with tetraethylammonium tetraselenotungstate (EuN^WSe4,1 (Scheme .6).
(structural formula(
Scheme 6
Chapter 4
In this chapter, a general method for the synthesis of thioesters is described. The reaction of p- nitrophenyl esters and disulfides with benzyltriethylammonium tetrathiomolybdate (PhCH2NEt3)2MoS4,2 furnished the corresponding thio esters in good yield (Scheme (7). The intramolecular version of this reaction furnished dimeric thiolactones as the major product (Scheme 8)
(structural formula)
Scheme 7
(structural formula)
Scheme 8
(for structural formula pl see the original document)
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Discovery of Small Peptides and Peptidomimetics Targeting the Substance P 1-7 Binding Site : Focus on Design, Synthesis, Structure-Activity Relationships and Drug-Like PropertiesFransson, Rebecca January 2011 (has links)
Biologically active peptides are important for many physiological functions in the human body and therefore serve as interesting starting points in drug discovery processes. In this work the neuropeptide substance P 1–7 (SP1–7, H-Arg-Pro-Lys-Pro-Gln-Gln-Phe-OH), which has been demonstrated to reduce neuropathic pain and attenuate opioid withdrawal symptoms in animal models, has been addressed in a medicinal chemistry program with the overall aim of transforming this bioactive peptide into more drug-like compounds. Specific binding sites for this neuropeptide have been detected in the brain and the spinal cord. Interestingly, the smaller neuropeptide endomorphin-2 (EM-2, H-Tyr-Pro-Phe-Phe-NH2) also interacts with these binding sites, although 10-fold less efficient. In this work the structure–activity relationship of SP1–7 and EM-2, regarding their affinity to the SP1–7 binding site was elucidated using alanine scans, truncation, and terminal modifications. The C-terminal part of both peptides, and especially the C-terminal phenylalanine, was crucial for binding affinity. Moreover, the C-terminal functional group should preferably be a primary amide. The truncation studies finally resulted in the remarkable discovery of H-Phe-Phe-NH2 as an equally good binder as the heptapeptide SP1–7. This dipeptide amide served as a lead compound for further studies. In order to improve the drug-like properties and to find a plausible bioactive conformation, a set of rigidified and methylated dipeptides of different stereochemistry, and analogs with reduced peptide character, were synthesized and evaluated regarding binding, metabolic stability and absorption. Small SP1–7 analogs with retained affinity and substantially improved permeability and metabolic stability were identified. Beside peptide chemistry the synthetic work included the development of a fast and convenient microwave-assisted protocol for direct arylation of imidazoles. Furthermore, microwave-assisted aminocarbonylation using Mo(CO)6 as a solid carbon monoxide source was investigated in the synthesis of MAP amides and for coupling of imidazoles with amino acids. In a future perspective the present findings, together with the fact that some of the SP1–7 analogs discovered herein have been shown to reproduce the biological effects of SP1-7 in animal studies related to neuropathic pain and opioid dependence, can ultimately have an impact on drug discovery in these two areas.
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New Methodologies in Organic Chemistry: Applications to the Synthesis of α-Amino Acids and Natural ProductsHirner, Sebastian January 2009 (has links)
This thesis deals with the development and application of new synthetic methodology in organic chemistry. The first part describes the development of a new protocol for the synthesis of 3-pyrrolines by means of a microwave-assisted ring-expansion reaction of 2-vinylaziridines. In addition, this methodology is implemented as a key-step in a formal total synthesis of the antibiotic (-)-anisomycin. In the second part, a new methodology for the synthesis of arylglycines from Weinreb amides is described. In this procedure, a Grignard reagent is added to the iminium ion formed from the Weinreb amide upon treatment with a base. When a chiral amide is used, the nucleophilic addition proceeds with high diastereoselectivity. Finally, an easy and straightforward synthesis of α-amino amides via a base-mediated rearrangement of modified Weinreb amides into N,O-acetals is presented. Subsequent arylation, alkylation, alkenylation or alkynylation of this intermediate affords the corresponding α-amino amides in excellent yields. Furthermore, a more generalized protocol for the α-arylation of Weinreb amides lacking an α-amino moiety is also discussed. / QC 20100719
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Produção de frutose a partir de hidrolisado enzimático de amido de mandioca /Cerqueira, Vanessa Cassoni, 1980- January 2012 (has links)
Orientador: Cláudio Cabello / Banca: Fernando Broetto / Banca: Magali Leonel / Banca: Ana Paula Cerino Coutinho / Banca: Mariana Schimidt Rechsteiner / Resumo: Os produtos das hidrólises de amido são glicose, maltose e uma série de oligossacarídeos e polissacarídeos que encontram utilização principalmente na indústria de alimentos. Neste grupo enquadram-se os adoçantes que aditam sabores a produtos que são demandados por consumidores específicos. Atualmente o açúcar mais utilizado no Brasil é a sacarose, produto extraído da cana-de-açúcar, e o mais utilizado mundialmente é a frutose obtida a partir da hidrólise do milho e posterior isomerização da glicose para frutose. A frutose apresenta capacidade edulcorante 30% maior que a sacarose, 2,5 vezes maior que a glicose e 2 vezes mais solúvel que a glicose, com isso, pode ser utilizada em menor quantidade, diminuindo o poder calórico do alimento e viabilizando sua utilização no tratamento da obesidade. Levando em consideração a importância dos adoçantes para o mercado de alimentos, o presente trabalho teve como objetivo realizar estudos sobre o processo de obtenção da frutose a partir de amido de mandioca. Para a execução dos ensaios utilizou-se fontes comerciais de α- amilase e amiloglucosidase, Liquozyme Supra 2.2X e Saczyme 750 AGUg-1, respectivamente, aplicadas em substrato de amido de mandioca em reator agitado com temperatura controlada. Após o processo de hidrólise enzimática, o hidrolisado passou por um processo de purificação utilizando terra diatomácea e carvão ativado em quatro temperaturas (30, 40, 50 e 60°C), com a finalidade de remoção de contaminantes originários da matéria prima, que levam a odor, cor e sabores indesejáveis. Após o tratamento com carvão ativo e terra diatomácea foram realizados ensaios para estabelecer os melhores parâmetros para a realização do processo de isomerização, buscando a conversão de parte da glicose à frutose, utilizando a enzima... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The products of starch hydrolyses are glucose, maltose and a series of oligosaccharides and polysaccharides which have their main utilization in food industry. This group comprises sweeteners that add flavor to products demanded by specific consumers. Currently the most used sugar in Brazil is sucrose, a product extracted from sugarcane, while the most used sugar worldwide is fructose obtained from maize hydrolysis and subsequent glucose isomerization to fructose. The sweetening capacity of fructose is 30% higher than that of sucrose and 2.5-fold higher than that of glucose; in addition, fructose is 2-fold more soluble than glucose and thus can be used in smaller quantities, decreasing the food's caloric potential and making its use viable in obesity treatment. Considering the importance of sweeteners for the food market, the present study aimed to investigate the process of fructose production from cassava starch. The assays were performed by using commercial sources of α-amylase and amyloglucosidase, Liquozyme Supra 2.2X and Saczyme 750 AGUg-1, respectively, applied to cassava starch substrate in an agitated reactor at controlled temperature. Following the process of enzymatic hydrolysis, the hydrolysate underwent a purification process using diatomaceous earth and activated charcoal at four temperatures (30, 40, 50 and 60°C), in order to remove contaminants originated from the raw material, which lead to undesirable smell, color and flavor. After the treatment with activated charcoal and diatomaceous earth, assays were carried out to establish the best parameters for the isomerization process, aiming at the conversion of part of glucose into fructose, using the enzyme isomerase. The process selected for the studies was in a continuous system where the glucose syrup, previously purified, was continuously pumped... (Complete abstract click electronic access below) / Doutor
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Síntese, atividades biológicas e estudo de relação estrutura-atividade de piperamidas / Synthesis, biological activities and structure-activity relationship study of piperamidesHarold Hilarion Fokoue 15 January 2015 (has links)
As estruturas e propriedades biológicas das amidas piplartina e a piperina, isoladas respectivamente de Piper tuberculatum e P. nigrum, inspiraram a síntese de 89 derivados e 7 esters estruturalmente relacionadas. As preparações envolveram metodologias tradicionais e os compostos purificados tiveram suas estruturas caracterizadas por análises espectroscópicas e espectrométricas. Os estudos de fragmentação por IE e IES indicaram a clivagem preferencial da ligação N-CO no caso das cinamamidas, dienamidas e cinamimidas. Estudos computacionais envolvendo afinidade protônica e energias de ligação confirmaram a fragmentação preferencial da ligação amídica para as amidas. A citotoxicidade de 89 substâncias foi avaliada contra três células leucêmicas (K562, Nalm6 e Raji) e a partir dos valores de IC50 foram realizados estudos de relação estrutura-atividade (SAR). As linhagens K562 e a Nalm6 foram a mais resistente e vulnerável, respectivamente, e as amidas piplartina (1a), N-Ciclohexil-N-(ciclohexilcarbamoil)-3-(3,4,5-trimetoxifenil)propanamida (1n), e (E)-N,N-dibutil-3-(3,4-dimetoxifenil)acrilamida (13h) foram as mais ativas com IC50 de 0,34 µM; 0,84 µM e 1,88 µM contra K562 e (E)-N-ciclohexil-N-(ciclohexilcarbamoil)-3-(3,4-dimetoxifenil)acrylamida (13i) com IC50 de 0,98 µM contra Nalm6. A avaliação de atividade leishmanicida de 18 substâncias não se mostrou promissora. As abordagens qualitativas e quantitativas foram feitas baseadas nos descritores moleculares gerados pelo programa VolSurf+. A partir de métodos quimiométricos tais com PLS, algoritmo genético, árvores de decisão foi possível gerar modelos para correlacionar às propriedades moleculares com a atividade biológica. As propriedades de absorção, distribuição, metabolismo e excreção e os equilíbrios entres as regiões hidrofílicas e hidrofóbicas foram importantes para atividade citotóxica. O estudo de ancoragem molecular mostrou que as amidas (E)-N,N-dibutil-3-(3,4,5-trimetoxifenil)acrilamida (1l), 1n, (E)-3-(4-clorofenil)-N-ciclohexil-N-(ciclohexilcarbamoil)acrilamida (5a), 13h e 13i podem atuar como inibidores das histonas desacetilases particularmente HDAC4 e HDAC8. / The structures and biological properties of the amides piplartine and piperine isolated from Piper tuberculatum and P. nigrum respectively, inspired the synthesis of derivatives 89 and 7 esters structurally related. Their preparations were achieved using classical procedures and the purified amides were submitted to spectroscopic and spectrometric characterization. The study of fragmentation process by EI and ESI suggested the preferential cleavage of the N-CO bond of cinnamamides, dienamides and cinnamimides. The cytotoxicity of 89 compounds was evaluated against three leukemic cells (K562, Nalm6 and Raji) and based on IC50 values the structure-activity relationship (SAR) was performed. While the K562 and Nalm6 cells were the more resistant and more sensitive, respectively, the amides piplartine (1a), N-cyclohexyl-N-(ciclohexylcarbamoyl)-3-(3,4,5-trimethoxyphenyl)propanamide (1n) and (E)-N,N-dibutyl-3-(3,4-dimethoxyphenyl)acrylamide (13h) were in general the most active with IC50 of 0.34 µM, 0.84 µM and 1.88 µM against K562 and (E)-N-cyclohexyl-N-(ciclohexylcarbamoyl)-3-(3,4-dimethoxyphenyl)acrylamide (13i) with IC50 of 0.98 µM against Nalm6. The evaluation of leishmanicidal activity of 18 substances was also performed but was not promising. Qualitative and quantitative approaches were made based on molecular descriptors generated by VolSurf+ program. The chemometric methods such as PLS, genetic algorithm, decision trees generated models to correlate molecular properties with the biological activity. The absorption, distribution, metabolism and excretion properties and a balance between hydrophilic and hydrophobic moieties of the amides were important for an optimized activity. The molecular docking revealed that amides such as (E)-N,N-dibutyl-3-(3,4,5-trimethoxyphenyl)acrylamide (1l), 1n, (E)-3-(4-chlorophenyl)-N-cyclohexil-N-(cyclohexylcarbamoyl)acrylamide (5a), 13h and 13i have potential to act as possible inhibitors of histone deacetylase proteins particularly HDAC4 and HDAC8.
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