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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Constituintes químicos e atividades antioxidante e antiproliferativa de extratos de Astraea Klotzsch e Croton L. (Euphorbiaceae) / Chemical constituents and antioxidant and antiproliferative activities of Astraea Klotzsch e Croton L. (Euphorbiaceae) extracts

Ogasawara, Daniela Carvalho 23 April 2012 (has links)
Plantas da família Euphorbiaceae, são produtoras de um grande e diversificado número de compostos secundários. Os gêneros Croton e Astraea são destaque nessa família, pois, possuem grande importância econômica devido ao seu elevado número de metabólitos secundários. O presente trabalho teve por objetivo ampliar o conhecimento sobre a composição química dos extratos de folhas e caules de seis espécies nativas (gêneros Croton e Astraea) e avaliar as atividades antioxidante e antiproliferativa. Entre os principais compostos encontrados estão α-cubebeno, β-cariofileno, aromadendreno, óxido de cariofileno, espatulenol, β-eudesmol, elixeno e o 8-isoproprenil-1,5-dimetilciclodeca-1,5-dieno e ledol, nos óleos voláteis; e os tilirosídeo, rutina e vitexina em flavonóides. Os extratos das folhas apresentaram maior eficiência antioxidante do que os extratos dos caules. C. triqueter foi a espécie que demonstrou maior atividade antioxidante tanto para os extratos das folhas quanto para os extratos dos caules. Todas as espécies demonstraram potencial biológico antioxidativo, incentivando assim novas pesquisas com essas espécies. Dos extratos analisados, os mais promissores para atividade antiproliferativa são os de C. campestris (folhas) e A. comosa (folhas e caules), pois apresentaram maior potencial antiproliferativo para as linhagens MCF-7 - mama, NCI-H460 - pulmão e K562 - leucemia. Este trabalho ajudou a ampliar o conhecimento químico e das atividades antioxidante e antiproliferativa sobre o gênero Croton e o gênero Astraea, que possuem enorme potencial biológico e mais de mil espécies distribuídas pelo mundo / Plants of the family Euphorbiaceae are producers of a great and varied number of secondary compounds. The genus Croton and Astraea are highlights in this family because they have great economic importance due to their high number of secondary metabolites. This present work aimed to expand the knowledge about the chemical composition of extracts of leaves and barks of six native species (genus Croton and Astraea) and evaluate the antioxidant and antiproliferative activities. Amongst the main compounds that were found are α-cubebene, β-cariophyllene, aromadendrene, cariophyllene oxide, spathulenol, β-eudesmol, ledol, elixene and 8-isoproprenyl-1,5-dimethyl-ciclodeca-1,5-diene, in the volatile oils; and the X,Y and Z in flavonoids. The extracts of the leaves presented more antioxidant efficiency than the extracts of the barks. C. triqueter was the species that demonstrated more antioxidant activity for the extracts of both the leaves and the barks. All the species demonstrated antioxidative biological potential, thereby encouraging new researches with these species. ). From the analyzed extracts, the most promising ones for antiproliferative activity are C. campestris (leaves) and A. comosa (leaves and barks), because they presented the highest antiproliferative potential for the cell lines MCF-7 - mammary, NCI-H460 - lung and K562 - leukemia. This work helped to expand the chemical knowledge and the antioxidant and antiproliferative activities of the genus Croton and the genus Astraea, that have great biological potential and more than one thousand species distributed around the world
22

Bioprospec??o de polissacar?deos sulfatados de macroalgas marinhas do litoral do Rio Grande do Norte: caracteriza??o de uma heterofucana extra?da da alga marron Sargassum filipendula que induz apoptose em c?lulas HeLa

Costa, Leandro Silva 08 March 2012 (has links)
Made available in DSpace on 2014-12-17T14:03:34Z (GMT). No. of bitstreams: 1 LeandroSC_DISSERT_1-68.pdf: 3005513 bytes, checksum: 4d385177273793fb97add8fa79a198b9 (MD5) Previous issue date: 2012-03-08 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The coast of Rio Grande do Norte has more than 100 species of seaweed, mostly unexplored regarding their pharmacological potential. The sulfated polysaccharides (PS) are by far the more seaweed compounds studied, these present a range of biological properties, such as anticoagulant activity, anti-inflammatory, antitumor and antioxidant properties. In this study, we extract sulfated polysaccharide rich-extracts of eleven algae from the coast of Rio Grande do Norte (Dictyota cervicornis; Dictiopterys delicatula; Dictyota menstruallis; Dictyota mertensis; Sargassum filipendula; Spatoglossum schr?ederi; Gracilaria caudata; Caulerpa cupresoides; Caulerpa prolifera; Caulerpa sertularioides e Codim isthmocladum), and these were evaluated for the potential anticoagulant, antioxidant and antiproliferative. All polysaccharide extracts showed activity for anticoagulant, antioxidant and/or antiproliferative activity, especially D. delicatula and S. filipendula, which showed the most prominent pharmacological potential, thereby being chosen to have their sulfated polysaccharides extracted. By fractionating method were obtained six fractions rich in sulfated polysaccharides to the algae D. delicatula (DD-0,5V, DD-0, 7V, DD-1,0v, DD-1,3v, DD-1,5v and DD-2,0) and five fractions to the alga S. filipendula (SF-0,5V, SF-0,7V, SF-1,0v, SF-1,5v and SF-2,0v). For the anticoagulant assay only the fractions of D. delicatula showed activity, with emphasis on DD-1, 5v that presented the most prominent activity, with APTT ratio similar to clexane? at 0.1 mg/mL. When evaluated the antioxidant potential, all fractions showed potential in all tests (total antioxidant capacity, hydroxyl and superoxide radicals scavenging, ferrous chelation and reducing power), however, the ability to chelate iron ions appears as the main mechanism antioxidant of sulfated polysaccharides from seaweed. In antiproliferative assay, all heterofucanas showed dose-dependent activity for the inhibition of cell proliferation of HeLa, however, with the exception of SF-0,7V, SF- 1,0v and SF-1,5v, all fractions showed antiproliferative activity against MC3T3, a normal cell line. The heterofucana SF-1,5V had its antiproliferative mechanism of action evaluated. This heterofucan induces apoptosis in HeLa cells by a pathway caspase independent, promoting the release of apoptosis Inducing Factor (AIF) in the cytosol, which in turn induces chromatin condensation and DNA fragmentation into 50Kb fragments. These results are significant in that they provide a mechanistic framework for further exploring the use of SF-1.5v as a novel chemotherapeutics against human cervical cancer. / O litoral do Rio Grande do Norte apresenta mais de 100 esp?cies de macroalgas marinhas, a maioria delas ainda n?o explorada quanto ao seu potencial farmacol?gico. Os polissacar?deos sulfatados (PS) s?o de longe os compostos de macroalgas marinhas mais estudados, sendo atribu?da a estes uma gama de propriedades biol?gicas, como: atividade anticoagulante, antiinflamat?ria, antitumoral e antioxidante. Neste trabalho, obteve-se extratos ricos em polissacar?deos de onze algas do litoral do Rio Grande do Norte (Dictyota cervicornis; Dictiopterys delicatula; Dictyota menstruallis; Dictyota mertensis; Sargassum filipendula; Spatoglossum schr?ederi; Gracilaria caudata; Caulerpa cupresoides; Caulerpa prolifera; Caulerpa sertularioides e Codium isthmocladum), e estas foram avaliadas quanto ao seu potencial anticoagulante, antioxidante e antiproliferativo frente ? linhagem celular tumoral HeLa. Todos os extratos polissacar?dicos apresentaram atividades anticoagulante, antioxidante e/ou antiproliferativa, com destaque para os das algas D. delicatula e S. filipendula, que apresentaram os maiores ?ndices de potencial farmacol?gico, sendo, portanto, escolhidas para serem submetidos a passos posteriores de purifica??o de seus polissacar?deos sulfatados. Atrav?s do fracionamento com volumes crescentes de acetona foram obtidas seis fra??es ricas em polissacar?deos sulfatados da alga D. delicatula (DD-0,5v, DD-0,7v, DD-1,0v, DD-1,3v, DD-1,5v e DD-2,0v) e cinco fra??es da alga S. filipendula (SF-0,5v, SF- 0,7v, SF-1,0v, SF-1,5v e SF-2,0v). An?lises f?sico-qu?micas mostraram que estas s?o ricas em heterofucanas sulfatadas. Apenas as fra??es da alga D. delicatula apresentaram atividade anticoagulante, com destaque para DD-1,5v que apresentou a atividade mais proeminente com raz?o de APTT semelhante ? clexane?, f?rmaco anticoagulante comercial. Quando avaliadas com rela??o ao potencial antioxidante todas as fra??es apresentaram atividade em todos os testes realizados (Capacidade antioxidante total, sequestro de radicais super?xido e hidroxila, quela??o f?rrica e atividade redutora), entretanto, a capacidade de quela??o de ?ons ferro aparece como o principal mecanismo antioxidante dos polissacar?deos sulfatados dessas macroalgas marinhas. No ensaio antiproliferativo, todas as heterofucanas apresentaram atividades dose-dependente para a inibi??o da prolifera??o celular de HeLa, entretanto, as fra??es SF-0,7v, SF-1,0v e SF-1,5v apresentaram atividade espec?fica para esta linhagem celular, n?o inibindo a prolifera??o da linhagem celular normal MC3T3, sendo a heterofucana SF-1,5v escolhida para ter seu mecanismo de a??o antiproliferativo determinado. SF-1,5v induz a apoptose em c?lulas HeLa principalmente atrav?s de uma via independente da ativa??o das caspases, promovendo a libera??o do Fator Indutor da Apoptose (AIF) no citosol, que por sua vez induz a condensa??o da cromatina e fragmenta??o do DNA em fragmentos de 50Kb. Este trabalho ? o primeiro relato mostrando uma heterofucana cujo principal mecanismo antiproliferativo ? a libera??o de AIF mitocondrial para o citosol, o que torna SF-1,5v um promissor f?rmaco na terapia antitumoral, possibilitando uma alternativa aos quimioter?picos tradicionais.
23

Extraction, identification, caractérisation des activités biologiques de flavonoïdes de Nitraria retusa et synthèse de dérivés acylés de ces molécules par voie enzymatique / Extraction, identification, characterization of biological activities of Nitraria retusa flavonoids and enzymatic synthesis of acylated derivatives of these molecules

Hadj Salem, Jamila 09 October 2009 (has links)
Ce travail a consisté, dans un premier temps, à extraire et à identifier les flavonoïdes majeurs contenus dans les feuilles de Nitraria retusa et à évaluer leurs activités biologiques. Quatre flavonoïdes ont été identifiés dans les extraits et les fractions obtenus : l’isorhamnétine, l’isorhamnétine-3-O-glucoside et les deux isomères isorhamnétine-3-O-rutinoside et isorhamnétine-3-O-robinobioside. L’étude des activités biologiques des extraits et des fractions de N. retusa a permis d’établir une relation linéaire entre leur teneur en flavonoïdes et leurs activités antioxydantes et antiprolifératives, les milieux les plus riches présentant les activités les plus importantes. Ces activités dépendent également de la nature des flavonoïdes présents ; ainsi, la très forte activité d’inhibition de la xanthine oxydase relevée pour la fraction au chloroforme et sa grande capacité à piéger le radical DPPH ont été attribuées à sa teneur élevée en isorhamnétine, flavonoïde aglycone présentant une grande analogie structurale avec la quercétine, molécule bien connue pour ses activités antioxydantes. Dans un deuxième temps, l’acylation enzymatique de l’isoquercitrine, flavonoïde modèle, et de l’isorhamnétine-3-O-glucoside a été étudiée pour tenter d’améliorer leurs propriétés. L’acylation enzymatique de l’isoquercitrine par des esters éthyliques d’acides gras de différentes longueurs de chaîne, catalysée par la lipase B de Candida antarctica, a montré que les performances de la réaction sont inversement proportionnelles à la longueur de la chaîne du donneur d’acyle. Des résultats similaires ont été obtenus lors de l’acylation de l’isorhamnétine-3-O-glucoside. Les activités des esters d’isoquercitrine et d’isorhamnétine-3-O-glucoside ont été évaluées et comparées à celles des flavonoïdes non acylés. Les esters ont montré des activités antiprolifératives vis-à-vis de cellules Caco2 et d’inhibition de la xanthine oxydase plus importantes que celles des molécules d’origine. Finalement, ce travail a permis d’apporter des éléments de compréhension de la relation structure-activité de flavonoïdes et de leurs dérivés acylés / The present work firstly consisted in studying the extraction and the identification of major flavonoids contained in Nitraria retusa leaves and evaluating their biological activities. Four flavonoids were identified in extracts and fractions: isorhamnetin, isorhamnetin-3-O-glucoside and the two isomers isorhamnetin-3-O-rutinoside and isorhamnetin-3-O-robinobioside. The evaluation of the biological activities of extracts and fractions of N. retusa allowed to establish a linear relationship between their antioxidant and antiproliferative activities and their total flavonoids content, the most enriched exhibiting the highest activities. The nature of the flavonoids present in the extracts and fractions was shown to be important too. Thus, the strong xanthine oxidase inhibition activity and the high DPPH radical scavenging capacity observed for the chloroform fraction can be attributed to its high content in the aglycone flavonoid isorhamnetin, a structural analogue of quercetin which is well known for its antioxidant activities. In a second part, the enzymatic acylation of isoquercitrin as a model compound and isorhamnetin-3-O-glucoside was studied in order to improve their properties. The enzymatic acylation of isoquercitrin by fatty acid ethyl esters of different chain lengths, catalyzed by the lipase B of Candida antarctica, showed that the performance of the reaction is inversely proportional to the acyl donor chain length. Similar results were obtained when acylating the isorhamnetin-3-O-glucoside. The activities of isoquercitrin and isorhamnetin-3-O-glucoside esters were determined and compared to that of initial flavonoids. Esters exhibited higher antiproliferative towards Caco2 cells and xanthine oxidase inhibition activities than original compounds. Finally, this work led to a better understanding of the structure-activity relationship of flavonoids and their acylated derivatives
24

Funkcionalne karakteristike fermentisanog čajnog napitka obogaćenog CoffeBerry®-jem / Functional characteristics of the fermented tea beverage enriched with CoffeBerry®

Ahmed Essawet Najmi 30 September 2016 (has links)
<p>Cilj ispitivanja čiji su rezultati prikazani u ovoj doktorskoj disertaciji bio<br />je da se ispita mogućnost dobijanja kombuha napitka od/sa CoffeeBerry&reg;<br />ekstraktom i da se ispitaju njegove funkcionalne karakteristike.<br />CoffeeBerry&reg; ekstrakt kao bogat izvor biolo&scaron;ki aktivnih jedinjenja bi<br />obezbedio dodatne funkcionalne karakteristike kombuha napitku u<br />poređenju sa onim pripremljenim na tradicionalan način od zaslađenog<br />crnog čaja. U disertaciji je nakon optimizacije sastava podloge za<br />kultivaciju čajne gljive ispitana (in vitro) antioksidativna, antimikrobna i<br />citotoksična aktivnost kombuhe/fermentacione tečnosti obogaćene<br />CoffeeBerry&reg; ekstraktom. Antioksidativna aktivnost je ispitana ESR<br />(elektron-spin rezonantnom) spektroskopijom na reaktivne hidroksil i<br />stabilne DPPH (1,1-difenil-2-pikrilhidrazil) radikale, kao i kvalitativni i<br />kvantitativni sastav fenolnih jedinjenja, potencijalnih nosilaca biolo&scaron;ke<br />aktivnosti (HPLC metodom). Antimikrobna aktivnost je ispitana agardifuzionom<br />metodom na odabrane referentne i izolovane (&bdquo;divlje&ldquo;)<br />sojeve bakterija (Gram-pozitivnih i Gram-negativnih) i kvasaca.<br />Citotoksična aktivnost uzoraka na rast odabranih ćelijskih linija: Hep2c<br />(Human larynx carcinom), RD (Rhabdomyosarcoma) i L2OB (mi&scaron;ija<br />tumorska fibrolastna linija u koju su transfektovani neki humani geni)<br />ispitana je MTT testom. U navedenim ispitivanjima je tradicionalna<br />kombuha dobijena od zaslađenog crnog čaja kori&scaron;ćena kao kontrolni<br />uzorak. Rezultati su pokazali da CoffeeBerry&reg; ekstrakt značajno<br />doprinosi antioksidativnoj i citotoksičnoj aktivnosti napitka &scaron;to govori o<br />punoj opravdanosti upotrebe ovog ekstrakta kao funkcionalnog dodatka<br />podlozi za kultivaciju čajne gljive. Kombuha napici od crnog čaja i sa<br />dodatkom CoffeeBerry&reg; ekstrakta pokazali su približno isto delovanje na<br />bakterijske sojeve, dok je delovanje na kvasce izostalo u potpunosti.<br />Primarni nosilac antibakterijske aktivnosti napitaka je sirćetna kiselina.</p> / <p>The aim of this study was to investigate fermentation of sweetened<br />medium prepared with CoffeeBerry&reg; еxtract and functional<br />characteristics of a kombucha beverage enriched with CoffeeBerry&reg;<br />еxtract. Total phenol concentration in unfermented samples,<br />fermentation broths and kombucha beverages made of CoffeeBerry&reg;<br />еxtract and black tea was determined spectrophotometrically whereas<br />qualitative and quantitative concentration of polyphenolic compounds<br />was determined by HPLC method. Antioxidant activity on DPPH and<br />hydroxyl radicals in the same samples was determined on an ESR<br />spectrometer. Fermentation broth and kombucha beverage enriched with<br />CoffeeBerry&reg; еxtract had higher antioxidant activity against both<br />radicals than control samples. Antimicrobial activity of kombucha<br />beverages optimal acidity was tested against selected strains of bacteria<br />(Gram-positive and Gram-negative) and yeast. The main active<br />component of antibacterial activity was acetic acid, but samples did not<br />show any activity against yeast Candida albicans and Saccharomyces<br />cerevisiae. Antiproliferative activity of fermentation broth with and<br />without CoffeeBerry&reg; еxtract was measured by MTT test on following<br />cell lines: Hep2c (Human larynx carcinom), RD (Rhabdomyosarcoma) i<br />L2OB (murine tumor fibrolast lines trаnsfеcted by some human genes).<br />The highest antiproliferative activity shown fermentation broth enriched<br />with CoffeeBerry&reg; еxtract, wherein Hep2c cells was the most<br />susceptible.</p>
25

Síntese total da (+)-trans-triquentrina A / Total synthesis of (+)-trans-trikentrin A

Tébéka, Iris Raquel Maia 28 September 2012 (has links)
Apresenta-se, nesta tese, a síntese total do alcaloide marinho (+)-trans-triquentrina A. Três abordagens foram investigadas como estratégias sintéticas: uma adição conjugada assimétrica, um acoplamento arílico com um complexo de ferro e uma resolução cinética enzimática. Esta última permitiu finalizar a síntese do produto natural em 20 etapas e com 0,6% de rendimento global. A síntese tem como etapas-chave a resolução cinética de um éster racêmico, mediada pela lipase da Pseudomonas cepacia - que forneceu o (S)-ácido correspondente em excelente excesso enantiomérico - e a contração de anel de um ciclo-hexeno substituído promovida por um sal de tálio(III), fornecendo seletivamente o composto trans-1,3-dimetilciclopentano correspondente. Efetuaram-se testes visando à síntese total da (+)-cis-triquentrina A a partir de um intermediário obtido da etapa de resolução cinética enzimática, que seria comum à síntese das duas moléculas-alvo. Investigou-se a atividade antiproliferativa da (+)-trans-triquentrina A, bem como a de intermediários da síntese e de produtos relacionados. Estes estudos permitiram descobrir compostos com atividade potente frente a linhagens de células tumorais humanas de ovário (GI50=0,31-0,42 &#181;g.mL-1) e de cólon (GI50=0,25 &#181;g.mL-1). / The total synthesis of marine alkaloid (+)-trans-trikentrin A is presented in this thesis. Three approaches were investigated as synthetic strategies: an asymmetric conjugate addition, an aryl coupling with an iron complex and an enzymatic kinetic resolution. The latter allowed the synthesis of the natural product to be achieved in 20 steps and 0.6% overall yield. The synthesis features as key steps a kinetic resolution of a racemic ester, which was mediated by the lipase from Pseudomonas cepacia, leading to the corresponding (S)-acid in excellent enantiomeric excess, as well as a thallium(III)-mediated ring contraction of a cyclohexene derivative that selectively afforded the corresponding trans-1,3- dimethylcyclopentanic compound. Studies toward the total synthesis of (+)-cis-trikentrin A were performed aiming to achieve both natural products from a common intermediate, obtained from the enzymatic kinetic resolution. The antiproliferative activity of (+)-trans-trikentrin A as well as that of intermediates and related products was investigated. Compounds with potent activity against ovarian (GI50=0.31- 0.42 &#181;g.mL-1) and colon (GI50=0.25 &#181;g.mL-1) tumor cell lines were discovered during these studies.
26

Síntese total da (+)-trans-triquentrina A / Total synthesis of (+)-trans-trikentrin A

Iris Raquel Maia Tébéka 28 September 2012 (has links)
Apresenta-se, nesta tese, a síntese total do alcaloide marinho (+)-trans-triquentrina A. Três abordagens foram investigadas como estratégias sintéticas: uma adição conjugada assimétrica, um acoplamento arílico com um complexo de ferro e uma resolução cinética enzimática. Esta última permitiu finalizar a síntese do produto natural em 20 etapas e com 0,6% de rendimento global. A síntese tem como etapas-chave a resolução cinética de um éster racêmico, mediada pela lipase da Pseudomonas cepacia - que forneceu o (S)-ácido correspondente em excelente excesso enantiomérico - e a contração de anel de um ciclo-hexeno substituído promovida por um sal de tálio(III), fornecendo seletivamente o composto trans-1,3-dimetilciclopentano correspondente. Efetuaram-se testes visando à síntese total da (+)-cis-triquentrina A a partir de um intermediário obtido da etapa de resolução cinética enzimática, que seria comum à síntese das duas moléculas-alvo. Investigou-se a atividade antiproliferativa da (+)-trans-triquentrina A, bem como a de intermediários da síntese e de produtos relacionados. Estes estudos permitiram descobrir compostos com atividade potente frente a linhagens de células tumorais humanas de ovário (GI50=0,31-0,42 &#181;g.mL-1) e de cólon (GI50=0,25 &#181;g.mL-1). / The total synthesis of marine alkaloid (+)-trans-trikentrin A is presented in this thesis. Three approaches were investigated as synthetic strategies: an asymmetric conjugate addition, an aryl coupling with an iron complex and an enzymatic kinetic resolution. The latter allowed the synthesis of the natural product to be achieved in 20 steps and 0.6% overall yield. The synthesis features as key steps a kinetic resolution of a racemic ester, which was mediated by the lipase from Pseudomonas cepacia, leading to the corresponding (S)-acid in excellent enantiomeric excess, as well as a thallium(III)-mediated ring contraction of a cyclohexene derivative that selectively afforded the corresponding trans-1,3- dimethylcyclopentanic compound. Studies toward the total synthesis of (+)-cis-trikentrin A were performed aiming to achieve both natural products from a common intermediate, obtained from the enzymatic kinetic resolution. The antiproliferative activity of (+)-trans-trikentrin A as well as that of intermediates and related products was investigated. Compounds with potent activity against ovarian (GI50=0.31- 0.42 &#181;g.mL-1) and colon (GI50=0.25 &#181;g.mL-1) tumor cell lines were discovered during these studies.
27

Antiproliferační aktivita nových analogů dexrazoxanu a jejich vliv na protinádorový účinek antracyklinů / Antiproliferative activity of novel dexrazoxane analogues and their effect on antitumor effectiveness of anthracyclines

Martinková, Pavla January 2014 (has links)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Biochemical Sciences Candidate: Bc. Pavla Martinková Supervisor: PharmDr. Anna Jirkovská, PhD. Title of diploma thesis: Antiproliferative activity of novel dexrazoxane analogues and their effect on antitumor effectiveness of anthracyclines Athracycline antibiotics (such as daunorubicin, doxorubicin or epirubicin) belong to the most common terapeutics of both solid tumors and hematological malignities. Unfortunately the serious and life-threatening adverse effect cardiotoxicity compromises their clinical usefulness. The only approved protection against anthracycline cardiotoxicity so far is dexrazoxane. Despite the outstanding cardioprotective ability, dexrazoxane use is very limited mainly due to its possible side effects. So we were directed towards synthesis of dexrazoxane analogues with better pharmacological properties. The aim of this diploma thesis was to assess the antiproliferative activity of novel analogues of both dexrazoxane (MK-15 and ES-5) and ADR-925 (JR-159 and KH- TA4) and their influence on the antiproliferative effectiveness of anthracyclines. Moreover, we aimed to study their chelating properties and their inhibition of the topoisomerase II in solution. We tested the antiproliferative activity of...
28

Synthèse et évaluation antiparasitaire de nouveaux dérivés du thiazole et apparentés / Synthesis and antiparasitic evaluation of new thiazole derivatives and related structures

Cohen Potier de Courcy, Anita 25 September 2012 (has links)
L'objectif de ce travail consiste en la synthèse et l'évaluation antiparasitaire in vitro de nouveaux dérivés du thiazole et apparentés. Plusieurs stratégies de synthèse visant à une pharmacomodulation en séries mono- et polycycliques ont été étudiées : en série 2-méthyl-5-nitrothiazole, la pharmacomodulation anti-Trichomonas de la position 4 par stratégie SRN1 n'a pas permis d'améliorer l'activité déjà démontrée en série 2-méthyl-5-nitroimidazole, mais a conduit à des dérivés à activité antiproliférative in vitro, spécifique de la lignée HepG2. En série 4-arylsulfonylméthyl-2-méthylthiazole, la pharmacomodulation de la position 5, par couplage de Suzuki-Miyaura d'une part, et par arylation directe et réaction de Knoevenagel intramoléculaire d'autre part, a conduit à des dérivés mono- et polycycliques dont certains ont démontré une activité antiplasmodiale in vitro encourageante. En série 5H-thiazolo[3,2-a]pyrimidin-5-one, la réaction de double couplage de Suzuki-Miyaura a révélé l'importance du groupement phényle en position 6 pour l'activité antiplasmodiale de ces dérivés. Enfin, l'évaluation biologique in vitro de thiéno[3,2-d]pyrimidin-4(3H)-ones a permis de caractériser le pharmacophore responsable de l'activité antiplasmodiale significative de cette série. Les résultats préliminaires encourageants d'une étude mécanistique antiplasmodiale présentent l'inhibition spécifique des kinases plasmodiales comme un mécanisme d'action potentiel de ces composés. / The objective of this work consists of the synthesis and the antiparasitic in vitro evaluation of new thiazole derivatives and related structures. Several synthetic strategies aiming at the pharmacomodulation on mono- and polycyclic series have been studied: in 2-methyl-5-nitrothiazole series, the anti-Trichomonas pharmacomodulation on position 4 by SRN1 strategy did not improve the activity previously demonstrated in 2-methyl-5-nitroimidazole series, but led to derivatives displaying a selective in vitro antiproliferative activity toward the HepG2 cell line. In 4-arylsulfonylmethyl-2-methylthiazole series, the pharmacomodulation on position 5, by Suzuki-Miyaura cross-coupling reaction on the one hand, and by direct arylation and intramolecular Knoevenagel reaction on the other hand, led to mono- and polycyclic derivatives among which some displayed an encouraging in vitro antiplasmodial activity. In 5H-thiazolo[3,2-a]pyrimidin-5-one series, a double Suzuki-Miyaura cross-coupling reaction revealed that the phenyl group on position 6 contributes to the antiplasmodial effect of this series. Finally, the in vitro biological evaluation of the thieno[3,2-d]pyrimidin-4(3H)-one scaffold let to characterize the pharmacophore responsible for the significant antiplasmodial activity. Some preliminary encouraging results regarding a mechanistic antiplasmodial study show the specific inhibition of plasmodial kinases, as a potential mechanism of action of some of these compounds.
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Compostos fenólicos de resíduos agroindustriais: identificação, propriedades biológicas e aplicação em matriz alimentar de base lipídica / Phenolic compounds of agroindustrial residues: identification, biological properties and application in lipid-based food matrix

Melo, Priscilla Siqueira 06 April 2016 (has links)
A geração de resíduos sólidos pelas atividades agroindustriais tem criado a demanda por um reaproveitamento tecnológico desses materiais. Assim, o objetivo deste trabalho foi avaliar o potencial bioativo e tecnológico de resíduos agroindustriais, como fontes naturais de compostos fenólicos com atividade antioxidante. Foram analisados resíduos agroindustriais vinícolas, de indústrias produtoras de polpas congeladas de frutas (açaí, cajá, cupuaçu e graviola) e provenientes do beneficiamento de café e de laranja. Inicialmente, foi realizado um estudo para a determinação das condições ótimas de extração, empregando planejamento experimental multivariado com delineamento composto central rotacional, cujos resultados foram avaliados empregando a técnica de superfície de resposta. Na sequência, foram feitos a triagem dos resíduos, baseada na atividade antioxidante, e a caracterização fenólica dos extratos hidroalcoólicos obtidos dos resíduos agroindustriais. De acordo com os resultados de atividade antioxidante, engaço de uva da variedade Chenin Blanc (EC) e semente de açaí (SA) foram os resíduos selecionados, os quais seguiram para as etapas de concentração e fracionamento bioguiado de sua(s) molécula(s) bioativa(s), as quais foram posteriormente identificadas por UHPLC-ESI-LTQ-MS. Extratos brutos e concentrados foram avaliados in vitro quanto à capacidade de desativação de espécies reativas de oxigênio (radicais peroxila, ânion superóxido e ácido hipocloroso) e então, aplicados em óleo de soja, emulsão e suspensão de lipossomos, a fim de se avaliar a efetividade desses extratos como antioxidante natural em matrizes lipídicas. Concentrações intermediárias de etanol (40-60%) e alta temperatura (96°C), exceto para semente de açaí (25°C), foram as condições ótimas para a extração de antioxidantes dos resíduos agroindustriais. Epicatequina, ácido gálico, catequina e procianidina B1 foram os compostos de maior ocorrência, quando avaliados pela técnica de HPLC-DAD. O EC apresentou a maior atividade antioxidante global e SA a maior atividade entre os resíduos de polpas de frutas, laranja e café. A concentração dos extratos brutos de EC e SA, pela resina Amberlite XAD&reg;-2, produziu aumento significativo da atividade antioxidante. Além disso, extratos brutos e concentrados apresentaram atividade antiproliferativa e anti-inflamatória. Os extratos concentrados foram fracionados por meio de Sephadex LH-20, a partir da qual foi possível identificar quatro frações de maior bioatividade para o EC e três para o SA. Procianidina B1, catequina, epicatequina e resveratrol foram identificados no extrato concentrado e frações de EC. Dezoito procianidinas poliméricas, catequina, epicatequina foram os principais compostos identificados em SA, por meio de UHPLC-ESI-LTQ-MS. Resveratrol também foi encontrado em SA pela primeira vez. Quando avaliados em óleo de soja, EC e SA demonstraram atividade pro-oxidante. Contudo, elevada atividade antioxidante foi verificada quando essas amostras foram aplicadas em sistemas lipídicos coloidais, pois retardaram o consumo de oxigênio em uma emulsão óleo/água e o período de indução na produção de dienos conjugados em uma suspensão de lipossomos. Portanto, os resíduos agroindustriais EC e SA possuem potencial tecnológico de reaproveitamento industrial podendo ser considerados possíveis matérias-primas para a obtenção de extratos ricos em antioxidantes ou pela extração de antioxidantes naturais de uso pelas indústrias farmacêutica e/ou de alimentos. / The solid waste generation by agroindustrial activities have created the demand for a technology reuse of these materials. The objective of this study was to evaluate the bioactive and technological potential of agroindustrial residues as sources of phenolic compounds with antioxidant activity. Agroindustrial residues from wineries, from industries producing frozen fruit pulps (acai, caja, cupuaçu and soursop) and from the processing of coffee and orange, were analyzed. Initially, a study using a multivariate experimental planning with central composite rotatable design was performed, whose results were evaluated by response surface technique. After, it was made the screening based on the antioxidant activity and the phenolic characterization of hydroalcoholic extracts of optimized agroindustrial residues. According to the results obtained for the antioxidant activity the residues grape stem from the variety Chenin Blanc (EC) and açaí seed (SA) were selected and followed to the steps of concentration and bioguided fractionation of their(s) molecule(s) bioactive(s), which were subsequently identified by UHPLC-ESI-LTQ-MS. Crude and concentrated extracts were evaluated in vitro for the deactivation capability of reactive oxygen species (peroxyl radicals, superoxide and hypochlorous acid) and then applied to soybean oil, emulsion and liposome suspension in order to evaluate the effectiveness these extracts as natural antioxidant in lipid matrices. Intermediate concentrations of ethanol (40-60%) and high temperature (96 °C), except for acai seed (25 °C) were the optimal conditions for the extraction of antioxidants from agroindustrial residues. Epicatechin, gallic acid, catechin and procyanidin B1 compounds were the most frequent molecules, when assessed by HPLC-DAD. The EC had the highest overall antioxidant activity and SA the greatest activity between residues of fruit pulp, orange and coffee. Concentration of the crude extracts of EC and SA, by Amberlite XAD&reg;-2 resin, produced a significant increase in antioxidant activity. Furthermore, crude and concentrated extracts showed antiproliferative and anti-inflammatory activity. The concentrated extracts were fractionated by Sephadex LH-20, from which it was possible to identify four fractions of greater bioactivity for the EC and three for SA. Procyanidin B1, catechin, epicatechin and resveratrol were identified in the concentrated extract and EC fractions. Eighteen polymeric procyanidins, catechin, epicatechin were the major compounds identified in SA by UHPLC-ESI-LTQ-MS. Resveratrol has also been found for the first time in SA. When evaluated in soybean oil, EC and SA demonstrated pro-oxidant activity. However, high antioxidant activity was observed when these samples were evaluated on lipid colloidal systems, for delayed oxygen consumption in an emulsion oil/water and the induction period in the production of conjugated dienes in a liposome suspension. Therefore, the agroindustrial residues EC and SA have technological potential for industrial reuse and, thus, can be considered as raw material for obtaining antioxidant-rich extracts or by extraction of natural antioxidants useful for pharmaceutical and/or food industries.
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Compostos fenólicos de resíduos agroindustriais: identificação, propriedades biológicas e aplicação em matriz alimentar de base lipídica / Phenolic compounds of agroindustrial residues: identification, biological properties and application in lipid-based food matrix

Priscilla Siqueira Melo 06 April 2016 (has links)
A geração de resíduos sólidos pelas atividades agroindustriais tem criado a demanda por um reaproveitamento tecnológico desses materiais. Assim, o objetivo deste trabalho foi avaliar o potencial bioativo e tecnológico de resíduos agroindustriais, como fontes naturais de compostos fenólicos com atividade antioxidante. Foram analisados resíduos agroindustriais vinícolas, de indústrias produtoras de polpas congeladas de frutas (açaí, cajá, cupuaçu e graviola) e provenientes do beneficiamento de café e de laranja. Inicialmente, foi realizado um estudo para a determinação das condições ótimas de extração, empregando planejamento experimental multivariado com delineamento composto central rotacional, cujos resultados foram avaliados empregando a técnica de superfície de resposta. Na sequência, foram feitos a triagem dos resíduos, baseada na atividade antioxidante, e a caracterização fenólica dos extratos hidroalcoólicos obtidos dos resíduos agroindustriais. De acordo com os resultados de atividade antioxidante, engaço de uva da variedade Chenin Blanc (EC) e semente de açaí (SA) foram os resíduos selecionados, os quais seguiram para as etapas de concentração e fracionamento bioguiado de sua(s) molécula(s) bioativa(s), as quais foram posteriormente identificadas por UHPLC-ESI-LTQ-MS. Extratos brutos e concentrados foram avaliados in vitro quanto à capacidade de desativação de espécies reativas de oxigênio (radicais peroxila, ânion superóxido e ácido hipocloroso) e então, aplicados em óleo de soja, emulsão e suspensão de lipossomos, a fim de se avaliar a efetividade desses extratos como antioxidante natural em matrizes lipídicas. Concentrações intermediárias de etanol (40-60%) e alta temperatura (96°C), exceto para semente de açaí (25°C), foram as condições ótimas para a extração de antioxidantes dos resíduos agroindustriais. Epicatequina, ácido gálico, catequina e procianidina B1 foram os compostos de maior ocorrência, quando avaliados pela técnica de HPLC-DAD. O EC apresentou a maior atividade antioxidante global e SA a maior atividade entre os resíduos de polpas de frutas, laranja e café. A concentração dos extratos brutos de EC e SA, pela resina Amberlite XAD&reg;-2, produziu aumento significativo da atividade antioxidante. Além disso, extratos brutos e concentrados apresentaram atividade antiproliferativa e anti-inflamatória. Os extratos concentrados foram fracionados por meio de Sephadex LH-20, a partir da qual foi possível identificar quatro frações de maior bioatividade para o EC e três para o SA. Procianidina B1, catequina, epicatequina e resveratrol foram identificados no extrato concentrado e frações de EC. Dezoito procianidinas poliméricas, catequina, epicatequina foram os principais compostos identificados em SA, por meio de UHPLC-ESI-LTQ-MS. Resveratrol também foi encontrado em SA pela primeira vez. Quando avaliados em óleo de soja, EC e SA demonstraram atividade pro-oxidante. Contudo, elevada atividade antioxidante foi verificada quando essas amostras foram aplicadas em sistemas lipídicos coloidais, pois retardaram o consumo de oxigênio em uma emulsão óleo/água e o período de indução na produção de dienos conjugados em uma suspensão de lipossomos. Portanto, os resíduos agroindustriais EC e SA possuem potencial tecnológico de reaproveitamento industrial podendo ser considerados possíveis matérias-primas para a obtenção de extratos ricos em antioxidantes ou pela extração de antioxidantes naturais de uso pelas indústrias farmacêutica e/ou de alimentos. / The solid waste generation by agroindustrial activities have created the demand for a technology reuse of these materials. The objective of this study was to evaluate the bioactive and technological potential of agroindustrial residues as sources of phenolic compounds with antioxidant activity. Agroindustrial residues from wineries, from industries producing frozen fruit pulps (acai, caja, cupuaçu and soursop) and from the processing of coffee and orange, were analyzed. Initially, a study using a multivariate experimental planning with central composite rotatable design was performed, whose results were evaluated by response surface technique. After, it was made the screening based on the antioxidant activity and the phenolic characterization of hydroalcoholic extracts of optimized agroindustrial residues. According to the results obtained for the antioxidant activity the residues grape stem from the variety Chenin Blanc (EC) and açaí seed (SA) were selected and followed to the steps of concentration and bioguided fractionation of their(s) molecule(s) bioactive(s), which were subsequently identified by UHPLC-ESI-LTQ-MS. Crude and concentrated extracts were evaluated in vitro for the deactivation capability of reactive oxygen species (peroxyl radicals, superoxide and hypochlorous acid) and then applied to soybean oil, emulsion and liposome suspension in order to evaluate the effectiveness these extracts as natural antioxidant in lipid matrices. Intermediate concentrations of ethanol (40-60%) and high temperature (96 °C), except for acai seed (25 °C) were the optimal conditions for the extraction of antioxidants from agroindustrial residues. Epicatechin, gallic acid, catechin and procyanidin B1 compounds were the most frequent molecules, when assessed by HPLC-DAD. The EC had the highest overall antioxidant activity and SA the greatest activity between residues of fruit pulp, orange and coffee. Concentration of the crude extracts of EC and SA, by Amberlite XAD&reg;-2 resin, produced a significant increase in antioxidant activity. Furthermore, crude and concentrated extracts showed antiproliferative and anti-inflammatory activity. The concentrated extracts were fractionated by Sephadex LH-20, from which it was possible to identify four fractions of greater bioactivity for the EC and three for SA. Procyanidin B1, catechin, epicatechin and resveratrol were identified in the concentrated extract and EC fractions. Eighteen polymeric procyanidins, catechin, epicatechin were the major compounds identified in SA by UHPLC-ESI-LTQ-MS. Resveratrol has also been found for the first time in SA. When evaluated in soybean oil, EC and SA demonstrated pro-oxidant activity. However, high antioxidant activity was observed when these samples were evaluated on lipid colloidal systems, for delayed oxygen consumption in an emulsion oil/water and the induction period in the production of conjugated dienes in a liposome suspension. Therefore, the agroindustrial residues EC and SA have technological potential for industrial reuse and, thus, can be considered as raw material for obtaining antioxidant-rich extracts or by extraction of natural antioxidants useful for pharmaceutical and/or food industries.

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