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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.
41

Příprava purinových a pyrimidinových derivátů s potenciální biologickou aktivitou. / Synthesis of purine and pyrimidine derivatives with potential biological activities.

Jansa, Petr January 2011 (has links)
An extensive overview of the current state of the research in the field of the development of acyclic nucleoside phosphonates (ANPs) was elaborated, which quotes from 196 publications in abstracted journals. A new microwave-assisted methodology for the preparation of dialkyl haloalkylphosphonates was developed. Through strict control of the reaction temperatures in microwave reactor, it was possible to lower the amount of the reactants all the way to the ideal ratio of 1:1. With the use of a continuous-flow microwave reactor, it was possible to prepare the key building blocks for the subsequent syntheses of ANPs in large quantities (100 g), which significantly accelerates research in this area. The new method was patented and published. While studying various ANP prodrugs, a new highly effective methodology for the preparation of the diamides of ANPs was developed. The method starts directly from ANP diesters, which react with trimethylsilylbromide to form the corresponding bis(trimethylsilyl)esters of ANPs, which are well soluble in organic solvents and react smoothly during the subsequent introduction of aminoacid esters. Moreover, the reaction with trimethylsilylbromide protects the reactive groups present in the rest of the molecule and thus prevents undesired side reactions. Furthermore, using...
42

Deriváty Amaryllidaceae alkaloidů jako látky potenciálně využitelné v terapii nádorových onemocnění / Derivatives of Amaryllidaceae alkaloids as potential drugs in the treatment of tumor diseases

Valachová, Iva January 2020 (has links)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacognosy Candidate: Iva Valachová Supervisor: Pharm.Dr. Daniela Hulcová, Ph.D. Title of diploma thesis: Derivatives of Amaryllidaceae alkaloids as potential drugs in the treatment of tumor diseases Twelve aromatic derivatives were prepared. The substitutions were performed on the hydroxyl group at C-3. This was acylated with differently substituted benzoyl chlorides affording the corresponding esters. Structural identification was performed by 1D- and 2D- NMR, ESI-HRMS spectroscopic techniques and optical rotation measurement. The yield of all reactions was more than 60 %. After converting these derivatives to hydrochlorides, their biological activity was tested. The Amaryllidaceae alkaloid vittaine itself exhibits cytotoxic activity and therefore its derivatives have been investigated in this respect. It has been tested against 9 cancerous and 1 non-cancerous cell lines. 3-O-(4-Chloro-3-nitrobenzoyl)vittatine showed the highest cytotoxic activity, unfortunatelly, it does not selectively affect only cancerous cells. Conversely, 3-O-(2-naphthoyl)vittatine has a selective effect on the HT-29 cancerous cell line (colorectal carcinoma) with a viability value of 32 ± 3 %, potentially being the subject of further studies of cytotoxicity...
43

Prospecção das interações mastoparano-membrana em proteolipossomos como modelo para o desenvolvimento racional de novos agentes antimicrobianos /

Silva, Alessandra Vaso Rodrigues da. January 2009 (has links)
Resumo: Neste trabalho estudou-se a estrutura, função e mecanismo de ação do peptídeo antibacteriano Protonectarina-MP (isolado de veneno da vespa social Protonectarina sylveirae) tendo seu resíduo C-terminal nas formas ácida (-OH) e amidada (-NH2). Os peptídeos foram sintetizados, utilizando-se a estratégia Fmoc, purificados por cromatografia líquida de alta performance. O monitoramento do material sintético foi feito por espectrometria de massas ESI-MS e por seqüenciamento através de Química Degradativa de Edman. A estrutura secundária foi investigada pelo uso de espectroscopia de dicroísmo circular e modelagem molecular. Atividade lítica (extravasamento) e interação do resíduo de triptofano em vesículas foram investigadas pelo uso de espectrômetro de fluorescência. Foram realizados ensaios sobre as interações desses peptídeos em meio de vesículas zwitteriônicas e aniônica, formando complexos proteolipossomos que foram submetidos à troca isotópica H/D monitorada por espectrometria de massas ESI-MS e MS/MS. Além disso, foram realizados ensaios biológicos de atividade hemolítica, de desgranulação de mastócito, de liberação da enzima citoplasmática Lactato Desidrogenase e de atividade antimicrobianas. Os dados de CD revelam uma tendência dos peptídeos se estruturarem em hélice-α em ambiente hidrofóbico e em ambiente de membranas. Porém, o mesmo não pode ser observado em meio aquoso. Os modelos obtidos para ambos os peptídeos por modelagem molecular mostram uma estruturação em hélice-α anfipática. Nos ensaios de atividade lítica em vesículas, os peptídeos apresentaram um processo com cooperatividade positiva, com curvas de dose-resposta que mostram uma dependência sigmoidal com a concentração do peptídeo. Os resultados da fluorescência do triptofanos mostram um deslocamento da emissão para a região de onda do azul para o peptídeo... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: In the present work was studied the structure, function and mechanism of action of the antibacterial peptide Protonectarina-MP (isolated from venom of social wasp Protonectarina sylveirae) with its carboxyamidation (-NH2) and carboxyl-free (-OH) Cterminal forms. The peptides were manually synthesized on-solid phase by using Fmoc strategy and purified under HPLC. The homogeneity of the synthetic material was analyzed by ESI mass spectrometry and Edman Degradation Chemistry. The secondary structure was investigated through circular dichroism (CD) spectroscopy and molecular modeling. Lytic activity and peptides interaction with the membranes was also investigated through tryptophan emission, by fluorescence spectrometry. The interaction of peptides with zwitterionic and anionic vesicles was investigated through the combination of H/D exchange and ESI-mass spectrometry. Some biological activities, like: mast cell degranulation, release of cytoplasmic enzyme lactate dehydrogenase, hemolysis and antibiosis were investigated for both peptides. The CD spectra revealed that the peptides in hydrophobic environments or in presence of biological membranes have the tendency to form helix conformations; however, organized structures were not observed in aqueous or buffer solutions. The models obtained by molecular modeling show that both peptides form an amphipathic α-helix. The peptides presented a positive cooperative process in the lytic activity of vesicles, with dose-response curves presenting a sigmoidal dependence with the peptide concentration. The results of the fluorescence of tryptophans showed a shift of the emission wavelength to the blue region of the peptide Protonectarina-MP (-NH2), which was not observed for its analogue presenting the C-terminal residue in free acid form. This is indicating a greater interaction of the amidated peptide in membranes, when compared to the peptide... (Complete abstract click electronic access below) / Orientador: Mario Sergio Palma / Coorientador: João Ruggiero Neto / Banca: Ivo Lebrun / Banca: Pietro Ciancaglini / Mestre
44

Estudo FitoquÃmico e BiolÃgico de Hymenaea courbaril L. / Phytochemical and Biological Study of Hymenaea courbaril L.

Josà ClÃudio Dias Aguiar 30 April 2009 (has links)
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / O estudo fitoquÃmico de Hymenaea courbaril L., conhecida popularmente como âjatobÃâ, foi realizado com as cascas dos frutos desta espÃcie, a qual tem aplicaÃÃes em processos inflamatÃrios e em distÃrbios intestinais. Das cascas dos frutos maduros, foi extraÃdo o Ãleo essencial, do qual 76,17% dos constituintes foram identificados, sendo -copaeno, o majoritÃrio. A composiÃÃo deste Ãleo foi comparada com a do Ãleo essencial obtido a partir dos frutos verdes, do qual 93,34% dos constituintes foram identificados, sendo germacreno-D, o majoritÃrio. Em ambos os Ãleos, foi verificada a presenÃa somente de sesquiterpenos. O estudo dos constituites fixos possibilitou o isolamento dos diterpenos ent-labdÃnicos, Ãcido zanzibÃrico e Ãcido isoÃzico, e do sesquiterpeno caryolano-1,9-diol, sendo, a Ãltima substÃncia, inÃdita no gÃnero Hymenaea. O estudo biolÃgico revelou bons agentes larvicidas sobre Aedes aegypti, para os Ãleos essenciais de frutos maduros e verdes, com valores de CL50 iguais a 14,85 Â 0,44 ppm e 28,44 Â 0,27 ppm, respectivamente. TambÃm, foi verificada uma satisfatÃria atividade antioxidante sobre o radical livre DPPH, com o extrato em metanol, com valor de CI50 igual a 0,04 mg/mL. O extrato em acetato de etila apresentou uma considerÃvel atividade alelopÃtica sobre Lactuca sativa L., com inibiÃÃo do crescimento de hipocÃtilos em 44,68%, na concentraÃÃo 0,4 mg/mL, e com inibiÃÃo do crescimento de radÃculas em 31,47%, na concentraÃÃo 0,8 mg/mL. / The phytochemical study of Hymenaea courbaril L., named âjatobÃâ, was executed by fruit`s bark of this vegetal, that is applied in inflammatory and intestinal diseases. Essential oil was extracted from mature fruit and 76,17% of the constituents were identified. The major constituent was -copaene. The composition of this oil was compared with the composition of the oil obtained on immature fruit, whose 93,34% of the constituents were identified. The major constituent of immature fruit was germacrene-D. Sesquiterpenes were present into both oils. The study of the fixe constituents permitted to isolate two ent-labdanic diterpenes, zanzibaric acid and isoozic acid, and the sesquiterpene caryolane-1,9-diol, that was a inedited substance in Hymenaea species. The biological study revealed that essential oils of mature fruit and immature fruit were satisfactory larvicidal agentes about Aedes aegypti and their LC50 14,85 Â 0,44 ppm and 28,44 Â 0,27 ppm, respective. A satisfactory antioxidant activity about DPPH free radicals was verified for extract in methanol whose IC50 0,04 mg/mL. The extract in ethyl acetate showed notable allelopathic effect on Lactuca sativa L., and hypocotyls growth was reduced in 44,68% (in concentration 0,4 mg/mL) and radicules growth was reduced in 31,47% (in concentration 0,8 mg/mL).
45

Bioprospecção de espécies amazônicas da família Lauraceae com potencial aromático e medicinal

Alcântara, Joelma Moreira 28 October 2009 (has links)
Made available in DSpace on 2015-04-22T22:02:16Z (GMT). No. of bitstreams: 1 Joelma Moreira.pdf: 4509931 bytes, checksum: bba95bccb3eff996782f9bce07ed8f0a (MD5) Previous issue date: 2009-10-28 / Fundação de Amparo à Pesquisa do Estado do Amazonas / The Amazon is one of the largest possessors of plant biodiversity on the planet. The constituents of the flora have enormous potential in the pharmaceutical, cosmetics, perfumes and essences, among others. This study aimed to search for Amazonian species of the Lauraceae potentially useful both therapeutically and commercially, holding alkaloidal composition or aromatic potential. The selected species were collected in Adolpho Ducke Forest Reserve, for this study were: Aniba panurensis, Aniba rosaeodora, Dicypellium manausense, Endlicheria chalisea, Licaria cannella angustata, Licaria martiniana, Mezilaurus duckei, Mezilaurus itauba, Ocotea nigrescens, Ocotea splendens, Rhodostemonodaphne negrensis, Rhodostemonodaphne parvifolia, Pleurothyrium vasquezii e Sextonia rubra. Of the species selected the ones with some chemical study are A. rosaeodora, A. panurensis and M. itauba. The essential oils were obtained by hydrodistillation and analyzed for their chemical composition (GC-FID, GC-MS and 1H NMR), where the -caryophyllene was the major constituent of most oils: leaves of A. panurensis (33.5%), D. manausense (39.5%), M. itauba (51.8%), O. nigrescens (37.9%) and O. splendens (51.0%); leaves and branches of L. martiniana (41.7% and 21.4%, respectively) and R. parvifolia (41.3% and 16.2%, respectively). For the other major oils constituents were caryophyllene epoxide, santalenone, -eudesmol, -pinene, germacrene D, p-cymene, -elemene, -copaene and linalool (89.4%) which is the main substance found in species A. rosaeodora. When testing inhibitory activity of free radicals, all essential oils showed inhibition of free radical DPPH qualitatively. However, quantitative analyses of active concentrations were very high, exceeding 700 g/mL. Only the essential oils of branches of L. martiniana and leaves of M. duckei and R. parvifolia showed inhibitory activity of acetylcholinesterase. Tests of platelet inhibition resulted in little potential antiplatelet agent with inhibition below 20%. Extracts of the genus Aniba, Licaria, Mezilaurus, Ocotea and Rhodostemonodaphne obtained by extraction with ethanol 100%, were subjected to phytochemical screening in which the presence of phenols, tannins, flavanones, saponins, steroids and alkaloids were shown to be frequent. The ethanol extracts of the species of A. panurensis, S. rubra and L. martiniana showed the highest antioxidant activity against DPPH free radical. The acetylcholinesterase inhibitory activity was higher in extracts of the Aniba and Licaria genus. Extracts of the Licaria genus were showed better activities against tumor cells SF-295 (human glioblastoma), HCT-8 (human colon) and MDAMB-435 (human breast). And for the bioassays against Leishmania amazonensis and Trypanosoma cruzi extract of leaves of A. panurensis showed the best activity (67 g/mL e 79 g/mL, respectively). The extracts that showed better biological activities should be fractionated for the isolation of active principles and retested / A Amazônia é uma das maiores detentora da biodiversidade vegetal do planeta. Os constituintes de sua flora apresentam enorme potencial nas indústrias farmacêuticas, de cosméticos, perfumes e essências, dentre outras. O presente trabalho teve por objetivo a pesquisa de espécies amazônicas da família Lauraceae potencialmente úteis tanto terapeuticamente quanto comercialmente, que possuam composição alcaloídica ou potencial aromático. As espécies selecionadas, coletadas na Reserva Florestal Adolpho Ducke, para este estudo foram: Aniba panurensis, Aniba rosaeodora, Dicypellium manausense, Endlicheria chalisea, Licaria cannella angustata, Licaria martiniana, Mezilaurus duckei, Mezilaurus itauba, Ocotea nigrescens, Ocotea splendens, Rhodostemonodaphne negrensis, Rhodostemonodaphne parvifolia, Pleurothyrium vasquezii e Sextonia rubra. Das espécies selecionadas as únicas que possuem algum estudo químico são A. rosaeodora, A. panurensis e M. itauba. Os óleos essenciais foram obtidos através de hidrodestilação e analisados quanto suas composições químicas (CG-DIC, CG-EM e RMN de 1H), em que o -cariofileno foi o constituinte majoritário da maioria dos óleos: folhas de A. panurensis (33,5%), D. manausense (39,5%), M. itauba (51,8%), O. nigrescens (37,9%) e O. splendens (51,0%); folhas e galhos de L. martiniana (41,7% e 21,4%, respectivamente) e R. parvifolia (41,3% e 16,2%, respectivamente). Para os demais óleos os principais constituintes foram epóxido de cariofileno, santalenona, -eudesmol, -pineno, germacreno D, p-cimeno, -elemeno, -copaeno, e o linalol (89,4%) que é a principal substância encontrada na espécie A. rosaeodora. Nos ensaios de atividade inibidora de radicais livres, todos os óleos essenciais apresentaram inibição do radical livre DPPH qualitativamente. Entretanto, na análise quantitativa as concentrações ativas foram muito altas, superiores a 700 g/mL. Apenas os óleos essenciais dos galhos de L. martiniana e das folhas de M. duckei e R. parvifolia apresentaram atividade inibidora de acetilcolinesterase. Os ensaios de inibição plaquetária resultaram em pouco potencial antiagregante plaquetário, com inibição inferior a 20%. Os extratos brutos, dos gêneros Aniba, Licaria, Mezilaurus, Ocotea e Rhodostemonodaphne, obtidos por extração com etanol 100%, foram submetidos a uma triagem fitoquímica na qual a presença de fenóis, taninos condensados, flavanonas, saponinas, esteróides e alcalóides mostraram-se frequente. Os extratos etanólicos das espécies de A. panurensis, S. rubra e L. martiniana foram os que mostraram maior atividade antioxidante frente ao radical livre DPPH. A atividade inibidora de acetilcolinesterase foi maior nos extratos dos gêneros Aniba e Licaria. Os extratos do gênero Licaria foram os que apresentaram melhores atividades contras as células tumorais SF-295 (glioblastoma humano), HCT-8 (cólon humano) e MDAMB-435 (mama humana). E para os bioensaios contra Leishmania amazonensis e Trypanosoma cruzi o extrato das folhas de A. panurensis foi o que apresentou melhor atividade (67 g/mL e 79 g/mL, respectivamente). Os extratos que apresentaram melhores atividades biológicas deverão ser fracionados para o isolamento dos princípios ativos e novamente testados
46

Caracterização química e atividades biológicas de algumas espécies nativas de Gracilaria de importância econômica / Chemical characterization and biological activities of some native species of Gracilaria with economic importance

Torres, Priscila Bezerra 23 March 2017 (has links)
Muitas espécies de Gracilaria são de importância econômica devido à exploração do ágar e, em menor escala, por serem consumidas diretamente na alimentação. Recentemente pesquisas têm mostrado um bom potencial biológico dessas espécies, porém com pouca investigação relacionada a identificação das substâncias bioativas. Sob esta perspectiva, o objetivo geral deste estudo foi investigar os componentes químicos majoritários e avaliar o potencial biológico e nutricional de três espécies nativas obtidas no litoral do nordeste brasileiro: Gracilaria birdiae E. M. Plastino & E. C. Oliveira Gracilaria caudata J. Agardh e Gracilaria domingensis (Kützing) Sonder ex Dickie. A análise da composição química levou a identificação de cerca de 50 substâncias distribuídas em alcanos, ácidos graxos livres, monossacarídeos, ácidos sulfônicos, aminoácidos livres, esteróis, heterosídeos, lipídios polares, monoacilgliceróis, polissacarídeos sulfatados, aminoácidos do tipo micosporinas e sais halogenados. Ésteres de ácidos graxos, ácidos carboxílicos aromáticos, fitol e o derivado fitona, diidroactinidiolideo também foram detectados em pequenas quantidades. Gracilaria caudata e G. domingensis foram muito semelhantes quimicamente. Já G. birdiae foi menos diversa, compartilhando, porém, muitas das substâncias majoritárias. Os resultados desse trabalho sugerem grande diversidade química para espécies de Gracilaria, ampliando o conhecimento disponível para Rhodophyta. Atividades biológicas promissoras foram detectadas para diversos ensaios. O extrato hexânico de G. caudata foi ativo frente as artêmias, com o isolamento biomonitorado de duas possíveis substâncias bioativas. O isolamento biomonitorado guiado pela atividade bioestimulante in vitro de plântulas de Lactuca sativa L. (alface) resultou no ácido palmítico como sendo responsável pelo aumento em 83% do crescimento de raiz. Os polissacarídeos sulfatados presentes nos extratos aquosos de G. caudata e G. domingensis foram bioestimulantes de raiz e folha de alface. Além disso, esses polissacarídeos de G. domingensis inibiu a atividade da enzima transcriptase reversa do HIV-1. Para G. birdiae vários extratos se mostraram com potenciais citotóxico e fitotóxico. Os aminoácidos tipo micosporinas (asterina 330, chinorina, palitina, palitinol e porphyra 334), por serem substâncias comuns em algas vermelhas, foram isolados e avaliados quanto ao potencial biológico. A palitina inibiu a atividade da enzima transcriptase reversa do HIV-1, enquanto porphyra 334, chinorina e também palitina apresentaram boa atividade antioxidante com o ensaio do reagente Folin-Ciocalteu. Quanto ao aspecto nutricional, os resultados indicaram que as três algas avaliadas, principalmente G. birdiae, foram ricas em fibras dietéticas e sais minerais, formando um grupo alimentar único bem diferente dos alimentos tradicionais na mesa dos brasileiros. Em resumo, os resultados obtidos para as espécies de Gracilaria avaliadas reforçaram a ideia de ampla diversidade química para as rodófitas, mostraram resultados promissores em diferentes ensaios, além de apontarem um potencial uso como fonte suplementar nas dietas dos brasileiros / Many Gracilaria species are economically important due to the exploitation of agar and, to a lesser extent, because they are consumed directly in the food. Recent studies have shown a good biological potential of these species, but with few studies aimed at the identification of bioactive substances. From this perspective, the general objective of this study was to investigate the major chemical components and to evaluate the biological and nutritional potential of three native species obtained in the northeast Brazilian coast: Gracilaria birdiae E. M. Plastino & E. C. Oliveira Gracilaria caudate J. Agardh and Gracilaria domingensis (Kützing) Sonder ex Dickie. The chemical composition analysis resulted in the identification of about 50 metabolites distributed as alkanes, free fatty acids, monosaccharides, sulfonic acids, free amino acids, sterols, heterosides, polar lipids, monoacylglycerols, sulfated polysaccharides, mycosporine-like amino acids and halogenated salts. Esters of fatty acids, aromatic carboxylic acids, phytol and the phytone derivative, dihydroactinidiolide were also detected in small amounts. G. caudate and G. domingensis were chemically similar. On the other hand G. birdiae was less diverse, sharing, however, many of the major metabolites. The results of this work suggest a great chemical diversity for Gracilaria species, increasing the knowledge available for Rhodophyta. Promising biological activities were detected for several assays. The hexane extract of G. caudate was active in brine shrimp lethality assay, with the biomonitoring isolation of two possible bioactive substances. The biomonitoring isolation guided by in vitro biostimulant activity of young Lactuca sativa L. (lettuce) seedlings resulted in palmitic acid as responsible for 83% increase in root growth. The sulfated polysaccharides present in the aqueous extracts of G. caudate and G. domingensis were biostimulant of root and lettuce leaf. In addition, these polysaccharides from G. domingensis inhibited the activity of the HIV-1 reverse transcriptase enzyme. For G. birdiae several extracts showed cytotoxic and phytotoxic potentials. Mycosporine-like amino acids (asterina 330, shinorine, palythine, palythinol and porphyra 334), known as common red algae substances, were isolated and evaluated for biological potential. Palythine inhibited the activity of the HIV-1 reverse transcriptase enzyme, while porphyra 334, shinorine and palythine showed good antioxidant activity using the Folin-Ciocalteu reagent assay. Regarding the nutritional aspect, the results indicated that from the three algae evaluated, highlighting G. birdiae, all were rich in dietary fibers and minerals, forming a unique food that is very different from the traditional Brazilian food. In summary, the results obtained for the Gracilaria species studied reinforced the idea of a wide chemical diversity for red algae, showing promising results in different bioassays, besides indicating a potential use as a supplementary food source in Brazilian diets
47

Caracterização estrutural e biológica das lectinas de sementes de Parkia biglobosa (Jacq.) Benth e Vatairea guianensis Aublet. / Characterization of structural and biological lectins seed Parkia biglobosa (Jacq.) Benth and Vatairea guianensis Aublet.

Silva, Helton Colares da January 2013 (has links)
SILVA, Helton Colares da. Caracterização estrutural e biológica das lectinas de sementes de Parkia biglobosa (Jacq.) Benth e Vatairea guianensis Aublet.. 2013. 137 f. Tese (Doutorado em Bioquímica)-Universidade Federal do Ceará, Fortaleza-CE, 2013. / Submitted by Eric Santiago (erichhcl@gmail.com) on 2016-07-20T12:51:25Z No. of bitstreams: 1 2013_tese_hcsilva.pdf: 3818572 bytes, checksum: ee5b011bca0f502caaafc45ea1effe6d (MD5) / Approved for entry into archive by José Jairo Viana de Sousa (jairo@ufc.br) on 2016-08-02T20:34:45Z (GMT) No. of bitstreams: 1 2013_tese_hcsilva.pdf: 3818572 bytes, checksum: ee5b011bca0f502caaafc45ea1effe6d (MD5) / Made available in DSpace on 2016-08-02T20:34:45Z (GMT). No. of bitstreams: 1 2013_tese_hcsilva.pdf: 3818572 bytes, checksum: ee5b011bca0f502caaafc45ea1effe6d (MD5) Previous issue date: 2013 / Lectins are defined as structurally heterogeneous proteins of non-immune origin, possessing at least one non-catalytic domain by which they reversibly bind to specific mono- or oligosaccharides. By deciphering the codes present in the glycan structure, lectins are attracting increasing interest in biotechnology. The most studied group of carbohydrate-binding proteins consists of lectins purified from species of the Leguminosae family. Among the studies of the lectins from Leguminosae. many are focused on members of the Papilionoideae subfamily, while investigations of lectins of the other two subfamilies, Caesalpinioideae and Mimosoideae, are scarce. Even within the subfamily Papilionoideae, the vast majority of studies focus on lectins from Phaseoleae and Vicieae tribes, while the other tribes of this subfamily are still poorly explored. In this context, this work describes the structural and biological characterization of two new lectins purified from seeds of Parkia biglobosa (Mimosoideae subfamily, tribe Parkiae) and Vatairea guianensis Aublet (subfamily Papilionoideae, tribe Dalbergieae). P. biglobosa seeds (subfamily Mimosoidae) possess mannose/glucose-specific lectin (PBL) that was purified by affinity chromatography on a Sephadex G-100 column. PBL is composed by a single nonglycosylated polypeptide chain of three tandemly arranged jacalin-related domains and showed important antinociceptive activity associated to the inhibition of inflammatory process. PBL was crystallized and the data produced in the X-ray diffraction experiments will enable the future resolution three-dimensional structure of this protein. With respect to the N-acetyl-D-galactosamine/D-galactose specific lectin present in the V. guianensis seeds (VGL) was demonstrated that this protein presents high similarity in primary structure to other lectins from evolutionarily related plants, such as VML and lectins belonging to the Sophoreae tribe. VGL exhibits vasorelaxant activity in contracted rat aortas, an effect that is strictly dependent on the endothelium and involves NO and the lectin domain. / Lectinas são proteínas que contém pelo menos um domínio não catalítico que se liga reversivelmente a mono ou oligossacarídeos específicos. Por serem capazes de “decifrar os glicocódigos” codificados na estrutura dos glicoconjugados, as lectinas são moléculas que possuem um grande potencial biotecnológico e despertam um grande interesse científico. As Lectinas de Leguminosas representam o grupo mais bem estudado, contudo a maioria dos estudos de lectinas de leguminosas tem envolvido membros da subfamília Papilionoideae, enquanto que investigações de lectinas de outras duas subfamílias, Caesalpinoideae e Mimosoideae, são escassas. Mesmo dentro da subfamília Papilionoideae, a grande maioria dos estudos com lectinas se concentram em membros da tribo Phaseoleae, prinicpalmente das subtribos Diocleinae e Vicieae, enquanto que as outras tribos desta subfamília ainda são pouco exploradas. Neste contexto, o presente trabalho descreve a caracterização estrutural e biológica das de duas novas lectinas purificadas de sementes de Parkia biglobosa (Subfamília Mimosoideae, tribo Parkiae) e Vatairea guianensis Aublet (Subfamília Papilionoideae, tribo Dalbergieae). Sementes de P. biglobosa possuem uma lectina (PBL) específica para manose/glicose que foi eficientemente purificada por cromatografia de afinidade em gel de Sephadex G-100. PBL é composta por uma cadeia polipeptídica única, não glicosilada e composta por três domínios relacionados a jacalina organizados em sequência. A lectina exibe atividade antiinflamatória que está associada à inibição da migração de leucócitos e uma atividade antiniciceptiva que pode estar associada à inibição da dor inflamatória. PBL foi cristalizada e os dados produzidos nos experimentos de difração do cristal por raios X possibilitarão a futura resolução da estrutura tridimensional desta proteína. Com relação a lectina específica para N-acetil-D-galactosamina/D-galactose presente nas sementes de V. guianensis (VGL) foi evidenciado que esta exibe similaridade de estrutura primária com outras lectinas isoladas de espécies de plantas taxonomicamente relacionadas, tais como lectinas isoladas da tribo Sophoreae e a lectina VML, com a qual VGL compartilha o mesmo processamento pós- traducional. Além disso, ficou evidente que VGL exibe um efeito vasorrelaxante in vitro em aortas de ratos, sendo que este efeito é dependente da presença de endotélio, envolve a participação do óxido nítrico e é mediado pelo sítio de ligação a carboidratos da lectina.
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Prospecção fitoquímica e atividade biológica de plantas medicinais da família asteraceae do bioma pampa / Phytochemical screening and biological activity of the medicinal plant family Asteraceae Pampa Biome

Stüke, Caroline Ziegler 09 April 2012 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / The species selected for this study were: Pluchea sagittalis, Baccharis pentodonta and Baccharidastrum triplinervium, all belonging to the Asteraceae family. The extracts and fractions from leaves and roots of three species of medicinal plants in Rio Grande do Sul were obtained by different extraction processes (cold, the hot water extraction and soxhlet) and subjected to HPLC analysis. These extracts and fractions were subjected to different fractionations were isolated where some secondary metabolites (chlorogenic acid derivatives and flavonoids). In the leaves of Pluchea sagittalis were isolated the secundary metabolites 3,4- dicaffeoylquinic acid, 3,5-dicaffeoylquinic acid and 4,5-dicaffeoylquinic acid. The crude extract of the root of the same species were isolated the same three metabolites 3,4-dicaffeoylquinic acid, 3,5-dicaffeoylquinic acid and 4,5-dicaffeoylquinic acid and the 1,3, 5-tricaffeoylquinic acid. Baccharis pentodonta were isolated metabolites 5,7,4'- trihydroxy-6-methoxy-luteolin and 5,7,3,4 - tretrahydroxy-6-methoxy-flavon for leaves and their metabolites 3,4-dicaffeoylquinic acid, 3,5-dicaffeoylquinic acid, 4,5- dicaffeoylquinic acid and 3-feruloyl-5-caffeoylquinic acid. The root Baccharidastrum triplinervium were isolated metabolites 3,4-dicaffeoylquinic acid, 3,5-dicaffeoylquinic acid and 4,5-dicaffeoylquinic acid already isolated from other species previously worked. The structures of these metabolites isolated was characterized by NMR analysis and high resolution mass. Additionally extracts and fractions obtained were tested in vitro and to determine their antimicrobial, antioxidant and enzyme inhibition against the enzyme DPP IV and POP. Most of the extracts and fractions tested showed antimicrobial activity by the method of microdilution around 0,5 mg ml-1 and moderate antioxidant activity by the method of free radical (DPPH) and the ethyl acetate fraction showed the highest potential. Among the activities of enzyme inhibition, the activity was more pronounced compared to POP, with only the crude extracts of the roots of B. pentodonta and B. triplinervium presented themselves as potential inhibitors of the enzyme DPP IV. / As espécies selecionadas para este estudo foram: Pluchea sagittalis, Baccharis pentodonta e Baccharidastrum triplinervium, todas pertencentes a família Asteraceae. Os extratos e frações das folhas e raízes destas três espécies de plantas medicinais do Rio Grande do Sul foram obtidos por diferentes processos de extração (a frio, a quente em soxhlet e extração aquosa) e submetidos à análise por CLAE. Estes extratos e frações obtidos foram submetidos a diferentes fracionamentos de onde foram isolados alguns metabólitos secundários (derivados do ácido clorogênico e flavonóides). Das folhas de Pluchea sagittalis foram isolados os metabólitos ácido 3,4-dicafeoilquínico, ácido 3,5-dicafeoilquínico e ácido 4,5-dicafeoilquínico. Do extrato bruto da raiz desta mesma espécie foram isolados os mesmos três metabólitos ácido 3,4-dicafeoilquínico, ácido 3,5-dicafeoilquínico e ácido 4,5-dicafeoilquínico além do ácido 1,3,5- tricafeoilquínico. De Baccharis pentodonta foram isolados os metabólitos 5,7,4 - triidroxi-6-metoxi-luteonina e 5,7,3,4 - tretrahidroxi-6-metoxi-flavona de suas folhas e os metabólitos ácido 3,4-dicafeoilquínico, ácido 3,5-dicafeoilquínico, ácido 4,5- dicafeoilquínico e ácido 3-feruloil-5-cafeoilquínico. Da raiz de Baccharidastrum triplinervium foram isolados os metabólitos ácido 3,4-dicafeoilquínico, ácido 3,5- dicafeoilquínico, ácido 4,5-dicafeoilquínico já isolados anteriormente das outras espécies trabalhadas. A elucidação estrutural desses metabólitos isolados se deu por RMN e por análises de massa de alta resolução. Adicionalmente os extratos e frações obtidos foram submetidos a testes in vitro e para determinação de suas atividades antimicrobiana, antioxidante e de inibição enzimática frente às enzimas POP e DPP IV. A maioria dos extratos e frações testados apresentou atividade antimicrobiana pelo método de microdiluição em caldo por volta de 0,5 mg mL-1 e atividade antioxidante moderada pelo método do radical livre (DPPH) sendo a fração acetato de etila a que apresentou maior potencial. Dentre as atividades de inibição enzimática, as atividade mais pronunciadas foram frente a POP, sendo que apenas os extratos brutos das raízes de B. pentodonta e B. triplinervium apresentaram-se como potenciais inibidores da enzima DPP IV.
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Valorisation de l'huile de Galba (Calophyllum calaba L.) : isolement, caractérisation et propriétés biologiques de ses actifs / Valorization of Galba oil (Calophyllum calaba L.) : isolation, characterization and biological properties of its active part

Lesaffre, Leïla 21 July 2016 (has links)
Dans un contexte de valorisation de la biodiversité, certaines espèces oléagineuses représentent une source intéressante de métabolites actifs. C’est le cas par exemple des espèces du genre Calophyllum qui sont utilisées en médecine traditionnelle pour leurs diverses propriétés. Elles ont déjà fait l’objet de nombreuses études afin de préciser leurs caractéristiques chimiques en relation avec leurs usages traditionnels. En Guadeloupe l’espèce la plus représentée est Calophyllum calaba L. ; l’huile de ses graines est utilisée pour traiter certaines affections dermatologiques (plaies, brûlures…) et lutter contre le vieillissement cutané. Au cours de ce travail, une méthode d’extraction a été mise au point afin de concentrer les métabolites secondaires de l’huile dans une partie appelée « résine ». Une étude chimique approfondie de cette résine a été réalisée par différentes techniques séparatives, analytiques et spectroscopiques. Des fractionnements successifs par chromatographie liquide/solide sur colonne de silice ont conduit à l’isolement de 14 composés. Des études analytiques et spectroscopiques ont permis de déterminer les structures de ces molécules, essentiellement de type pyranochromanone. Parmi ces composés, 4 correspondent à de nouvelles structures identifiées et décrites pour la première fois .L’huile de Galba, ses fractions et produits purs ont ensuite été testés pour leurs activités biologiques relatives à la sphère dermatologique. Leurs propriétés anti-oxydantes ont été déterminées par différentes méthodes in vitro : ORAC, DPPH, BCBT. L’activité anti-inflammatoire a été évaluée par dosage des nitrites et du TNF-α dans une culture cellulaire de macrophages stimulés par le LPS. La mesure de la concentration minimale inhibitrice de ces extraits sur 5 souches bactériennes impliquées dans des pathologies cutanées a permis d’évaluer leur activité antimicrobienne. Leur potentiel cicatrisant a été mis en évidence sur des cultures cellulaires de fibroblastes humains et de kératinocytes HaCaT, de même que leur influence sur la mélanogénèse. Enfin, l’évaluation de la capacité de certaines fractions à inhiber l’élastase et la collagénase montre l’intérêt de l’utilisation de l’huile pour ses propriétés anti-âge. Notre étude a permis de montrer que les activités biologiques de l’huile de Galba sont principalement liées aux métabolites secondaires de la résine. De plus, des précisions ont pu être apportées sur la nature des constituants impliqués dans les différentes activités biologiques étudiées.Ces résultats constituent un appui scientifique à l’utilisation traditionnelle de l’huile de Galba et permettent d’élargir son champ d’application dans le domaine dermocosmétique. / In the context of biodiversity’s valorization, some oleaginous species are a good source of active metabolites. This is the case of Calophyllum species that are used in traditional medicine for their various properties. Many studies have been done on this botanical genus to clarify the chemical composition but also the biological activities of various parts of these plants. In Guadeloupe, Calophyllum calaba L. is the most widespread species, the oil from its seeds is used to treat certain skin problems (wounds, burns ...) and prevent skin aging.During this study, a method of extraction was developed to concentrate the secondary metabolites of the oil in a part called "resin".A thorough study of the chemical compounds of the resin was carried out by various analytical and spectroscopic techniques. Successive fractionations by liquid/solid chromatography on silica column led to the isolation of fourteen compounds. Extensive analytical and spectroscopic studies allowed to know the structures of these molecules which were essentially pyranochromanone type. Among these compounds, four of them correspond to new structures identified and described for the first time.Galba Oil, its fractions and pure products were then tested for different biological activities relative to the dermatological field. The antioxidant properties were determined by various in vitro methods: ORAC, DPPH, BCBT. The anti-inflammatory activity was assessed by determination of nitrite and TNF-α in cell culture of macrophages stimulated by LPS. The measurement of the minimal inhibitory concentration of these extracts on 5 bacterial strains involved in cutaneous pathologies allowed to know their antimicrobial activity. Their wound-healing potential has been demonstrated in cell cultures of human fibroblasts and keratinocytes HaCaT, as well as their action on melanogenesis. Finally, the ability of certain fractions to inhibit elastase and collagenase may be related to the use of this oil for its anti-aging properties.Our study has shown that most of biological activities were linked to the secondary metabolites of the resin. In addition, some clarifications were made on the nature of the constituents involved in the different biological activities which were studied.These results provide scientific support to the traditional use of Galba oil and broaden its use in the dermocosmetic area.
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Atividade anticoagulante, antioxidante e antitumoral de heterofucanas da alga Dictyopteris delicatula (Lamouroux, 1809)

Magalhaes, Kaline Dantas 02 December 2011 (has links)
Made available in DSpace on 2014-12-17T14:13:58Z (GMT). No. of bitstreams: 1 KalineDM_DISSERT.pdf: 984274 bytes, checksum: 8150a2011f0eac140bc8113ffa4bc1ea (MD5) Previous issue date: 2011-12-02 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / In the present study, six families of sulfated polysaccharides were obtained from seaweed Dictyopteris delicatula (Lamouroux, 1809) and their anticoagulant, antioxidant and antitumor activities were evaluated. All fractions showed anticoagulant activity on aPTT assay, but not on PT assay. Fractions also exhibited total antioxidant activity, superoxide radical scavenging capacity and ferric chelating property. Thus, six fractions (F0.5v, F0.7v, F1.0v, F1.3v, F1.5v e F2.0v) we obtained by proteolytic digestion, followed by acetone fractionation and molecular sieving on Sephadex G-100. Chemical analyses demonstrated that all polysaccharides contain heterofucans composed mainly of fucose, xylose, glucose, galactose, uronic acid, and sulfate. Any fractions changed the PT. However, all fractions were able on double the aPPT on a dose-dependent manner. The heterofucans F0.7v and F1.0v showed low anticoagulant activity while F1.5v presented the most prominent anticoagulant activity .When compared to Clexane?, a low molecular weight heparin, at same concentration F1.5v presented similar anticoagulant activity. The fucans F0.5v and F0.7v at 1.0 mg/mL showed high ferric chelating activity (~45%), whereas fucans F1.3v (0.5 mg/mL) showed considerable reducing power, about 53.2% of the activity of vitamin C. The fucan F1.5v presented the most prominent anticoagulant activity. The best antiproliferative activity was found with fucans F1.3v and F0.7v. However, F1.3v activity was much higher than F0.7v inhibiting almost 100% of HeLa cell proliferation. These fucans have been selected for further studies on structural characterization as well as in vivo experiments, which are already in progress / No presente estudo, seis popula??es de polissacar?deos sulfatados foram obtidas a partir da alga Dictyopteris delicatula (Lamouroux, 1809) e suas atividades anticoagulante, antioxidante e antitumoral avaliadas. Deste modo, as seis fra??es (F0.5v, F0.7v, F1.0v, F1.3v, F1.5v e F2.0v) foram obtidas por prote?lise seguida por fracionamento de acetona e gel filtra??o molecular Sephadex G-100. Todas as fra??es apresentaram atividade anticoagulante frente ao ensaio de aPTT, mas n?o sobre o ensaio de PT. As heterofucanas exibiram atividade antioxidante total, capacidade em sequestrar radicais super?xido e propriedade de quelar ferro. As an?lises qu?micas demonstraram que todos os polissacar?deos cont?m heterofucanas composta principalmente por fucose, xilose, glicose, galactose, ?cido ur?nico, e sulfato. Nenhuma das fra??es alterou o PT. Entretanto, todas as fra??es foram capazes de dobrar o aPTT de uma maneira dose dependente. As heterofucanas F0.7v e F1.0v demonstraram baixa atividade anticoagulante, enquanto a F1.5v apresentou a maior atividade anticoagulante e quando comparada com Clexane?, uma heparina de baixo peso molecular, em mesma concentra??o, apresentou antividade anticoagulante semelhante. As fucanas F0.5v e F0.7v a 1,0 mg/mL mostraram alta atividade de quela??o ferica (~ 45%), enquanto a fucana F1.3v (0,5 mg/mL) mostrou consider?vel potencial redutor, cerca de 53,2% da atividade da vitamina C. A melhor atividade antitumoral foi encontrada nas fucanas F1.3v e F0.7v. No entanto, a atividade F1.3v foi muito superior a F0,7v, quase 100% de inibi??o da prolifera??o de c?lulas HeLa (c?lula de c?ncer de colo de ?tero). Estas fucanas foram selecionadas para novos estudos sobre caracteriza??o estrutural, bem como em experimentos in vivo, que j? est?o em andamento / 2020-01-01

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