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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.
1

Monomeric Ellagitannins in Oaks and Sweetgum

Lei, Zhentian 15 May 2002 (has links)
Ellagitannins are plant phenolics characterized by biaryl-coupled gallic acid moieties esterified to a D-glucose core. They are widely distributed through higher plants. In the case of oaks, ellagitannin concentrations in heartwood can reach up to 10% (dry wt. basis). These secondary metabolites are not only important physiologically but also influence the economic value and quality of wood products that contain them. Efforts were made to develop and validate the methods used to quantify both soluble and insoluble ellagitannins. First, the efficiencies of the two commonly used extraction solvents, aqueous acetone and aqueous methanol were evaluated. The results showed that aqueous acetone is superior to aqueous methanol in obtaining higher vescalagin and castalagin yields. In a separate study, the method used for determining insoluble ellagitannins was found to under-estimate the contents of insoluble ellagitannins in wood products. Anhydrous methanolic HCl was found to be an excellent reagent for releasing insoluble ellagic acid and gallic acid (as methyl gallate) from biomass substrates. Optimization of both the reaction conditions and the gradient HPLC analysis has led to the development of a robust and reliable protocol. The chemical stability of the two predominant ellagitannins in oaks (vescalagin and castalagin) were evaluated in aqueous methanol and water. It was found that oxygen, pH and higher temperature (60 °C) affect their stability with higher temperature being the most prominent factor. Both vescalagin and castalagin were found unstable in methanolic solutions. Vestalagin, however, is less stable than castalagin. In the course of finding alternative models for ellagitannin biosynthesis study, both callus tissues and suspension cell cultures of white oak (Quercus alba) and sweetgum (Liquidambar styraciflua) were investigated for their possible use as models for ellagitannin biosynthesis. It was found that oak callus tissue cultures (Quercus alba) are capable of producing ellagitannins, and the production and profile of ellagitannins can be modified by adjusting the media composition. Comparison of extracts from the heartwood of Quercus alba with those from callus tissue reveals that they have similar ellagitannin profiles. Through manipulation of the media nitrogen and copper concentrations the callus tissue produced almost 3 times as much castalagin and vescalagin. Suspension cells of Quercus alba and Liquidambar styraciflua were found to be unsuitable for the study of biosynthesis of ellagitannins. These cells either did not produce any detectable level of ellagitannins or the production was unstable. Although the suspension cells could be elicited to produce ellagic acid with glycanases (Driselase), the levels of ellagic acid were too low for quantitative metabolic studies. A method using high performance liquid chromatography – mass spectrometry was developed and optimized with purified ellagitannins. Ellagitannins analyzed under the optimal conditions all provide base peaks of (M-H)- from which the molecular weights of the ellagitannins can be determined. Mild fragmentation was also achieved to give fragments characteristic of ellagitannins (loss of ellagic acid and gallic acid if present). These characteristic peaks allow for rapid identification of ellagitannins from other secondary metabolites present in the samples. Application of the HPLC/ESI-MS in the identification of monomeric ellagitannins in white oak heartwood extracts revealed that it can unambiguously identify the two monomeric ellagitannins, castalagin and vescalagin, and their degradation product, ellagic acid. The key fragmentation pathways of the ellagitannins are also described. Finally, preliminary work using proteomics to study the heartwood formation was conducted. Proteins from transition zone and sapwood were determined and resolved with two-dimensional electrophoresis. It was found that both sapwood and transition woods contain active enzyme(s) capable of catalyzing formation of ellagic acid from pentagalloylglucose. Preliminary results from the 2-D gel separation of sapwood and transition wood proteins showed more protein spots in sapwood than in transition wood, suggesting that sapwood not only had higher protein levels but also a great total number of proteins. The lower complexity of the transition wood proteome suggests that this material may be a good substrate for studying the biaryl-coupling process. / Ph. D.
2

Réactivité de polyphénols du vin sous conditions oxydantes : hémisynthèse des mongolicaïnes, et d’adduits entre polyphénols et thiols odorants / Reactivity  of  wine  polyphenols  under  oxidative  conditions : hemisynthesis of mongolicains and adducts between polyphenols and odorous thiols

Petit, Emilie 29 November 2013 (has links)
Le vin est un milieu complexe qui évolue tout au long des étapes devinification. Pour mieux appréhender ses qualités et ses défauts, de nombreuses équipesde recherche s’intéressent à la compréhension de la chimie du vin. Dans ce contexte, lesujet de ce mémoire concerne l’étude de l’évolution chimique de certaines moléculespolyphénoliques du vin sous conditions oxydantes et/ou acides, afin d’isoler et decaractériser de nouveaux composés susceptibles de se former dans le vin. Deux aspectssont examinés. Le premier concerne l’oxydation de deux flavano‐ellagitannins, lesacutissimines A et B, formées à partir d’un monomère de tannins condensés, lacatéchine, et d’un ellagitannin C‐glucosidique, la vescalagine, extraite du bois de chênepar le vin lors de l’élevage en barrique. Cette étude a permis d’isoler les mongolicaïnes Aet B et deux analogues du camelliatannin G et de mettre en évidence leur formation parun mécanisme d’autoxydation. Le deuxième aspect concerne l’évaluation desconséquences de la présence de certains polyphénols dans le vin sur les composésthiolés odorants. Leur comportement et leur réactivité chimiques sont décrits dans desmilieux différents, avec l’hémisynthèse de thio‐ellagitannins sous conditions acides, et laformation d’adduits thio‐catéchols et thio‐pyrogallols sous conditions oxydantes,transformations chimiques pouvant occasionner la perte des odeurs et arômes du vindus aux composés thiolés odorants. / The wine is a complex medium that evolves throughout the different stages ofthe wine making process. To understand both the qualities and defects of wine,numerous research team worldwide investigate the chemistry of wine. In this context,the subject of this thesis concerns the study of the chemical evolution of some winepolyphenolic molecules under oxidizing and/or acidic conditions in the aim of isolatingand characterizing new compounds likely formed in wine. Two aspects are examined.The first one is the study of the oxidation of two flavano‐ellagitannins, acutissimins Aand B, formed from a monomer of condensed tannins, catechin, and a C‐glucosidicellagitannin, vescalagin, extracted from oak wood by the wine solution during its agingin barrels. This study led to the isolation of mongolicains A and B and two analogues ofcamelliatannin G, and revealed their formation according to an autoxydationmechanism. The second aspect of this work concerns the consequences of the presencein wine of some polyphenols on wine odorous thiols. Their chemical behavior andreactivity are described in different media, with the hemisynthesis of thio‐ellagitanninsunder acidic conditions, and the formation of thio‐catechol and thio‐pyrogallol adductsunder oxidizing conditions, chemical transformations that could explain the loss ofodors and aromas due to wine odorous thiols.
3

Synthèse de dérivés de polyphénols bioactifs pour l’étude de leurs interactions avec des protéines / Polyphenol derivatization and polyphenol-protein interactions by surface plasmon resonance

Delannoy, Daniela Mélanie 02 July 2012 (has links)
Ce travaille de thèse concerne la synthèse de dérivés de polyphénols de type flavanol, ellagitannins C-glucosidique et procyanidine, modifiés avec un espaceur comportant une biotine terminale. Cette biotine terminale a permis d’immobiliser ces polyphénols modifiés sur des surfaces SPR, permettant ainsi l’étude d’interactions polyphénol-protéine en temps réel. Ainsi, la topoisomerase II alpha et l'actine fibrilaire ont montré une plus grande affinité pour les polyphenols de type ellagitannins que pour ceux de type flavanol. Nous avons également pu montrer que d’autres protéines (BSA, myoglobine, actine globulaire, streptavidine, collagen type I) n’avaient pas d’interaction avec les flavanols et les ellagitannins. / This work concerns the synthesis of derivatives of polyphenols of the type flavanol, C-glucosidic ellagitannin and procyanidin, which are modified to bear a spacer ending with a biotin unit. This biotin ending unit allowed to immobilize these modified polyphenols on to SPR surfaces, which allowed the study of polyphenol-protein interactions in real time. The proteins topoisomerase II alpha and fibrilar actin showed a higher affinity for the polyphenols of the type ellagitannins than for those of the type flavanol. It was also showed that other proteins (BSA, myoglobin, globular actin, streptavidin, collagen type I) did not interact with either the flavanols or the ellagitannins
4

Bioconversion des ellagitannins de la mûre tropicale de montagne (Rubus Adenotrichos) et relation avec l'écologie du microbiome intestinal / Metabolic fate of ellagitannins from tropical highland blackberry (R. adenotrichos) and relation with gut microbiota ecology

Garcia Munoz, Maria-Cristina 12 December 2013 (has links)
La consommation d'aliments riches en ellagitannins (ETs) pourrait être associée principalement à la prévention des maladies cardiovasculaires et la régulation des cancers hormono-dépendants. Néanmoins, les ETs ne sont pas biodisponibles en tant que tel et, après avoir été partiellement transformés en acide ellagique (EA) dans le tractus gastro-intestinal (GI) supérieur, ils sont métabolisés dans le côlon par la flore intestinale en urolithines, un groupe de molécules plus biodisponibles et bioactives qui peuvent persister jusqu'à 4 jours à des concentrations relativement élevées dans le plasma et l'urine. La variabilité de l'excrétion des urolithines dans l'urine est importante et à partir d'un échantillon de population de 26 volontaires sains, trois groupes principaux d'individus ont pu être distingués : "faible ou non-excréteur d'urolithin », « Excréteur prédominant d'UA et dérivés» et « Excréteur prédominant d'UB et dérivés»". Ces groupes ont également été observés en considérant la cinétique totale d'excrétion sur une période de 4 jours après ingestion du jus et à des périodes différentes tout au long d'une année. Bien que les variabilités inter-et intra-individuelles soient relativement élevées, les individus conservent leur statut au cours des différentes périodes d'intervention même en modifiant les quantités d'ETs ingérées. L'analyse par UPLC-PDA/ESI-Q-TOF/MS2 a permis d'attribuer hypothétiquement une identité à 15 autres métabolites d'ETs dans l'urine, mais le profilage métabolomique n'a pas permis de discriminer d'autres composés exceptés les dérivés d'UA ou d'UB. La fermentation in-vitro des ETs et EA, par les matières fécales a montré une voie métabolique spécifique qui débouche sur la production d'UA. Néanmoins, les métabolites excrétés in vivo sont beaucoup plus complexes ce qui met en évidence de fortes interactions entre le système excréteur de l'hôte et la composition du microbiote intestinal. La recirculation hépatique suivie par une re-conversion des métabolites de phase II dans le côlon permettrait d'expliquer l'excrétion d'UB chez certains volontaires. L'écologie spécifique de la flore intestinale évaluée par la méthode des empreintes PCR-DGGE a permis d'identifier quelques microorganismes associés à une plus grande capacité de bioconversion des ETs en urolithins / Consumption of dietary ellagitannins (ETs) could be associated mainly with prevention of cardiovascular diseases and regulation of hormone-dependent cancers. Nonetheless, ETs are not bioavailable as such; therefore, after being partially converted into ellagic acid (EA) in the upper gastrointestinal (GI) tract, they undergo sequential bioconversion in the colon by gut microbiota into urolithins, a more bioavailable and bioactive group of molecules that persist up to 4 days at relatively high concentrations in urine. Variability of urolithin excretion in urine is high and three main groups, “no or low urolithin excreters,” “predominantly UA derivatives excreters” and “predominantly UB derivatives excreters,” were observed on a cohort of 26 healthy volunteers. These categories were also unambiguously observed following the total excretion of main ETs' metabolites over a 4 day period after ingesting one shot of juice, and at different periods of time along one year. Although relatively high inter- and intra-individual variabilities were observed, individuals preserved their status during various intervention periods with different amounts of ETs ingested. UPLC-PDA and ESI-Q-TOF/MS1 and MS2 allowed the tentative assignment of an identity to 15 other ETs metabolites in urine, but this profiling did not allow the discrimination of any other compounds aside from UA or UB derivatives. In-vitro fermentation of ETs and EA with fecal stools showed a specific metabolic pathway ending in the production of UA. Nonetheless, metabolites excreted in-vivo are much more complex, highlighting strong interactions between host excretory system and composition of gut microbiota. Hepatic recirculation and additional bioconversion of Phase II metabolites in the colon may explain predominant excretion of UB in some volunteers. Microbiota ecology assessed by PCR-Denaturing Gradient Gel Electrophoresis (DGGE) fingerprint method allowed the association of some microorganism species to higher capacity of bioconversion of dietary ETs into urolithins.Key words: Ellagitannins, blackberry, urolithin, colonic metabolites, ETs degradation patterns, gut microbiota, gastrointestinal tract,
5

Efeito de extratos ricos em antocianinas ou elagitaninos de amora silvestre (Morus nigra L.), amora preta (Rubus spp), e grumixama (Eugenia brasiliensis Lam) no crescimento e na expressão de genes e miRNAs de diferentes linhagens de céluas humanas de câncer de mama. / Effects of extracts rich in anthocyanins or ellagitans from mulberry (Morus nigra L.), blackberry (Rubus spp) and grumixama (Eugenia brasiliensis Lam) on cellular growth and gene and miRNAs expression from distinctive human breast cancer cell lines.

Costa, Gabriela Rezende 28 September 2017 (has links)
O câncer de mama caracteriza-se globalmente como a neoplasia de maior incidência e mortalidade na população feminina. Antocianinas e elagitaninos presentes em frutas como as berries destacam-se por seu promissor efeito protetor em diferentes estágios do desenvolvimento do câncer de mama. Grumixama (G; Eugenia brasiliensis Lam) é uma espécie de cereja nativa do Brasil que assim como as amora-preta (AP; Rubus spp) e silvestre (AS; Morus nigra L.) contém alto teor de antocianinas e elagitaninos. Poucos estudos focaram na ação anticâncer destas berries no câncer de mama. Portanto, o objetivo do presente estudo foi avaliar os efeitos de extratos ricos em antocianinas ou elagitaninos de G, AP e AS no crescimento e na expressão de genes e miRNAs das linhagens de células humanas de câncer de mama MCF-7 (receptor de hormônio positiva) e MDA-MB 231 (receptor de hormônio negativa). Não se observou citotoxicidade após 72 e 96 horas de tratamento com os extratos (25-200&#181g/mL) ricos em antocianinas (ASANT, APANT e GANT) ou elagitaninos (APELA e GELA), em ambas as linhagens celulares. Após 72 horas de tratamento, GANT e APANT induziram parada de ciclo celular em G0/G1 (12,5 e 50&#181g/mL, p<0,05) em células MCF-7. Após 96h, ASANT, APANT e GANT induziram parada de ciclo celular em G0/G1 (12,5 e 50&#181g/mL; p<0,05) nessas mesmas células. Entretanto, na concentração de 200&#181g/mL apenas GANT induziu parada em G0/G1 (72 e 96h; p<0,05). Em células MDA-MB 231, após 96h APANT e GANT induziram parada de ciclo celular em G0/G1 nas concentrações testadas (12,5, 50 e 200&#181g/mL, p<0,05), assim como ASANT nas concentrações de 12,5 e 50&#181g/mL (p<0,05). Em células MCF-7, após 72h APELA e GELA induziram aumento da proporção de células em subG0 (200&#181g/mL, p<0,05). Em MDA-MB 231, após 72 e 96h, APELA e GELA (200&#181g/mL) induziram aumento da proporção de células em subG0 (p<0,05) e parada em G0/G1 (p<0,05). Em células MCF-7, GANT induziu morte celular por apoptose (p<0,05) após 72 e 96h de tratamento. Entretanto, em MDA-MB 231 os extratos ricos em antocianinas não induziram morte celular. Em células MCF-7, após 96h GELA e APELA induziram principalmente necrose (p<0,05). Em MDA-MB 231, APELA e GELA induziram apoptose (p<0,05) após 72 e 96h. Em células MDA-MB 231, após 72h de tratamento foi observada inibição da proliferação celular por GELA, GANT e APELA (200&#181g/mL; p<0,05). Em células MDA-MB 231, 48h de tratamento com GELA; GANT e APELA (200&#181g/mL) aumentaram a expressão 5 genes (ESR2, FOXA1, JUN, PTGS2,VEGFA) e inibiram a expressão de 10 genes (ADAM23, ATM, BCL2, CDH1, EGF, GLI1, ID1, MKI67, SNAI2 e THBS1) correlacionados ao câncer de mama. Adicionalmente, GELA; GANT e APELA (200&#181g/mL) induziram aumento da expressão de miR- 210(p<0,05) e APELA (200&#181g/mL) reduziu a expressão de miRNA 19a/b (p<0,05) em células MDAMB 231. Coletivamente estes resultados sugerem que antocianinas de grumixama e elagitaninos de amora preta e grumixama apresentam potencial efeito protetor contra o câncer de mama. Adicionalmente, essa ação anticarcinogênica pode ser mediada por indução de morte celular, mais especificamente apoptose, redução de proliferação celular e modulação da expressão de genes e miRNAs relacionados ao câncer de mama. / Breast cancer is characterized as the neoplasia with the highest incidence and mortality rates in women worldwide. Anthocyanins and ellagitannins present in certain fruits, such as berries, stand out for their promising protective effect at different stages of breast cancer development. Grumixama (G; Eugenia brasiliensis Lam), a cherry species from Brazil, as well as blackberry (AP; Rubus spp) and mulberry (AS; Morus nigra L.) contain elevated concentrations of anthocyanins and ellagitannins. Few studies focused on the anticarcinogenic action of these berries in breast cancer development. Therefore, the aim of the present study was to evaluate the effects of extracts rich in anthocyanins or ellagitannins from G, AP and AS on cellular growth and genes and miRNAs expression in human MCF-7 (hormone receptor positive) and MDA-MB 231 (hormone receptor negative) cell lines. No cytotoxicity was observed after 72 and 96 hours of treatment with extracts rich in anthocyanin (25-200 &#181g/mL) (ASANT, APANT and GANT) or ellagitannins (APELA and GELA) in both cell lines. After 72 hours of treatment, GANT and APANT induced cell cycle arrest at G0/G1 (12.5&#181g/mL and 50&#181g/mL, p<0.05) in MCF-7 cells. After 96h, ASANT, APANT and GANT induced cycle arrest at G0/G1 (12.5 and 50&#181g/mL; p<0.05) in MCF-7 cells. However, at 200&#181g/mL, only GANT induced G0/G1 (72 and 96h; p<0.05). In MDA-MB 231 cells, after 96h APANT and GANT induced cell cycle arrest at G0/G1 with the three tested concentrations (12.5, 50 and 200&#181g/mL, p<0.05), as well as ASANT at concentrations 12,5 and 50&#181g/mL (p <0.05). In MCF-7 cells, after 72h APELA and GELA induced an increase in the proportion of cells in subG0 (200&#181g/mL, p<0.05). In MDA-MB 231, after 72 and 96h, APELA and GELA (200&#181g/mL) induced an increase in the proportion of cells in subG0 (p<0.05) and cell cycle arrest in G0/G1 (p<0.05). In MCF-7 cells, GANT induced apoptosis (p<0.05) after 72 and 96h of treatment. However, in MDA-MB 231, extracts rich in anthocyanins did not induce cell death. In MCF-7 cells, after 96h GELA and APELA induced mainly necrosis (p<0.05). In MDA-MB 231, APELA and GELA induced apoptosis (p<0.05) after 72 and 96h. In MDA-MB 231 cells, inhibition of cell proliferation by GELA, GANT and APELA (200?g/mL; p<0.05) was observed after 72h of treatment. In MDA-MB 231 cells, treatment for 48h with GELA, GANT and APELA (200&#181g) increased expression of 5 genes (ESR2, FOXA1, JUN, PTGS2, VEGFA) and inhibited expression of 10 genes (ADAM23, ATM, BCL2, CDH1, EGF, GLI1, ID1, MKI67, SNAI2 and THBS1) correlated with breast cancer. In addition, GELA; GANT and APELA (200&#181g/mL) induced increased expression of miR-210 (p<0.05) and APELA (200&#181g/mL) reduced the expression of miRNA 19a/b (p<0.05) in MDA-MB cells 231. Collectively these results suggest that anthocyanins of grumixama and ellagitannins of blackberry and grumixama have potential protective effect against breast cancer. Additionally, this anticarcinogenic action can be mediated by induction of cell death, more specifically apoptosis, reduction of cell proliferation and modulation of the expression of genes and miRNAs related to breast cancer.
6

Efeito de extratos ricos em antocianinas ou elagitaninos de amora silvestre (Morus nigra L.), amora preta (Rubus spp), e grumixama (Eugenia brasiliensis Lam) no crescimento e na expressão de genes e miRNAs de diferentes linhagens de céluas humanas de câncer de mama. / Effects of extracts rich in anthocyanins or ellagitans from mulberry (Morus nigra L.), blackberry (Rubus spp) and grumixama (Eugenia brasiliensis Lam) on cellular growth and gene and miRNAs expression from distinctive human breast cancer cell lines.

Gabriela Rezende Costa 28 September 2017 (has links)
O câncer de mama caracteriza-se globalmente como a neoplasia de maior incidência e mortalidade na população feminina. Antocianinas e elagitaninos presentes em frutas como as berries destacam-se por seu promissor efeito protetor em diferentes estágios do desenvolvimento do câncer de mama. Grumixama (G; Eugenia brasiliensis Lam) é uma espécie de cereja nativa do Brasil que assim como as amora-preta (AP; Rubus spp) e silvestre (AS; Morus nigra L.) contém alto teor de antocianinas e elagitaninos. Poucos estudos focaram na ação anticâncer destas berries no câncer de mama. Portanto, o objetivo do presente estudo foi avaliar os efeitos de extratos ricos em antocianinas ou elagitaninos de G, AP e AS no crescimento e na expressão de genes e miRNAs das linhagens de células humanas de câncer de mama MCF-7 (receptor de hormônio positiva) e MDA-MB 231 (receptor de hormônio negativa). Não se observou citotoxicidade após 72 e 96 horas de tratamento com os extratos (25-200&#181g/mL) ricos em antocianinas (ASANT, APANT e GANT) ou elagitaninos (APELA e GELA), em ambas as linhagens celulares. Após 72 horas de tratamento, GANT e APANT induziram parada de ciclo celular em G0/G1 (12,5 e 50&#181g/mL, p<0,05) em células MCF-7. Após 96h, ASANT, APANT e GANT induziram parada de ciclo celular em G0/G1 (12,5 e 50&#181g/mL; p<0,05) nessas mesmas células. Entretanto, na concentração de 200&#181g/mL apenas GANT induziu parada em G0/G1 (72 e 96h; p<0,05). Em células MDA-MB 231, após 96h APANT e GANT induziram parada de ciclo celular em G0/G1 nas concentrações testadas (12,5, 50 e 200&#181g/mL, p<0,05), assim como ASANT nas concentrações de 12,5 e 50&#181g/mL (p<0,05). Em células MCF-7, após 72h APELA e GELA induziram aumento da proporção de células em subG0 (200&#181g/mL, p<0,05). Em MDA-MB 231, após 72 e 96h, APELA e GELA (200&#181g/mL) induziram aumento da proporção de células em subG0 (p<0,05) e parada em G0/G1 (p<0,05). Em células MCF-7, GANT induziu morte celular por apoptose (p<0,05) após 72 e 96h de tratamento. Entretanto, em MDA-MB 231 os extratos ricos em antocianinas não induziram morte celular. Em células MCF-7, após 96h GELA e APELA induziram principalmente necrose (p<0,05). Em MDA-MB 231, APELA e GELA induziram apoptose (p<0,05) após 72 e 96h. Em células MDA-MB 231, após 72h de tratamento foi observada inibição da proliferação celular por GELA, GANT e APELA (200&#181g/mL; p<0,05). Em células MDA-MB 231, 48h de tratamento com GELA; GANT e APELA (200&#181g/mL) aumentaram a expressão 5 genes (ESR2, FOXA1, JUN, PTGS2,VEGFA) e inibiram a expressão de 10 genes (ADAM23, ATM, BCL2, CDH1, EGF, GLI1, ID1, MKI67, SNAI2 e THBS1) correlacionados ao câncer de mama. Adicionalmente, GELA; GANT e APELA (200&#181g/mL) induziram aumento da expressão de miR- 210(p<0,05) e APELA (200&#181g/mL) reduziu a expressão de miRNA 19a/b (p<0,05) em células MDAMB 231. Coletivamente estes resultados sugerem que antocianinas de grumixama e elagitaninos de amora preta e grumixama apresentam potencial efeito protetor contra o câncer de mama. Adicionalmente, essa ação anticarcinogênica pode ser mediada por indução de morte celular, mais especificamente apoptose, redução de proliferação celular e modulação da expressão de genes e miRNAs relacionados ao câncer de mama. / Breast cancer is characterized as the neoplasia with the highest incidence and mortality rates in women worldwide. Anthocyanins and ellagitannins present in certain fruits, such as berries, stand out for their promising protective effect at different stages of breast cancer development. Grumixama (G; Eugenia brasiliensis Lam), a cherry species from Brazil, as well as blackberry (AP; Rubus spp) and mulberry (AS; Morus nigra L.) contain elevated concentrations of anthocyanins and ellagitannins. Few studies focused on the anticarcinogenic action of these berries in breast cancer development. Therefore, the aim of the present study was to evaluate the effects of extracts rich in anthocyanins or ellagitannins from G, AP and AS on cellular growth and genes and miRNAs expression in human MCF-7 (hormone receptor positive) and MDA-MB 231 (hormone receptor negative) cell lines. No cytotoxicity was observed after 72 and 96 hours of treatment with extracts rich in anthocyanin (25-200 &#181g/mL) (ASANT, APANT and GANT) or ellagitannins (APELA and GELA) in both cell lines. After 72 hours of treatment, GANT and APANT induced cell cycle arrest at G0/G1 (12.5&#181g/mL and 50&#181g/mL, p<0.05) in MCF-7 cells. After 96h, ASANT, APANT and GANT induced cycle arrest at G0/G1 (12.5 and 50&#181g/mL; p<0.05) in MCF-7 cells. However, at 200&#181g/mL, only GANT induced G0/G1 (72 and 96h; p<0.05). In MDA-MB 231 cells, after 96h APANT and GANT induced cell cycle arrest at G0/G1 with the three tested concentrations (12.5, 50 and 200&#181g/mL, p<0.05), as well as ASANT at concentrations 12,5 and 50&#181g/mL (p <0.05). In MCF-7 cells, after 72h APELA and GELA induced an increase in the proportion of cells in subG0 (200&#181g/mL, p<0.05). In MDA-MB 231, after 72 and 96h, APELA and GELA (200&#181g/mL) induced an increase in the proportion of cells in subG0 (p<0.05) and cell cycle arrest in G0/G1 (p<0.05). In MCF-7 cells, GANT induced apoptosis (p<0.05) after 72 and 96h of treatment. However, in MDA-MB 231, extracts rich in anthocyanins did not induce cell death. In MCF-7 cells, after 96h GELA and APELA induced mainly necrosis (p<0.05). In MDA-MB 231, APELA and GELA induced apoptosis (p<0.05) after 72 and 96h. In MDA-MB 231 cells, inhibition of cell proliferation by GELA, GANT and APELA (200?g/mL; p<0.05) was observed after 72h of treatment. In MDA-MB 231 cells, treatment for 48h with GELA, GANT and APELA (200&#181g) increased expression of 5 genes (ESR2, FOXA1, JUN, PTGS2, VEGFA) and inhibited expression of 10 genes (ADAM23, ATM, BCL2, CDH1, EGF, GLI1, ID1, MKI67, SNAI2 and THBS1) correlated with breast cancer. In addition, GELA; GANT and APELA (200&#181g/mL) induced increased expression of miR-210 (p<0.05) and APELA (200&#181g/mL) reduced the expression of miRNA 19a/b (p<0.05) in MDA-MB cells 231. Collectively these results suggest that anthocyanins of grumixama and ellagitannins of blackberry and grumixama have potential protective effect against breast cancer. Additionally, this anticarcinogenic action can be mediated by induction of cell death, more specifically apoptosis, reduction of cell proliferation and modulation of the expression of genes and miRNAs related to breast cancer.
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Synthèse totale de la vescaline, substance naturelle bioactive de la famille des ellagitannins C-arylglucosidiques / Total synthesis of vescalin, natural bioactive substance of the C-arylglucosidic ellagitannin family

Richieu, Antoine 22 December 2017 (has links)
Les ellagitannins C-arylglucosidiques sont des composés polyphénoliques issus du métabolisme spécialisé de nombreuses plantes, en particulier celles appartenant à la famille des Fagacées comme le chêne et le châtaignier. La vescaline qui appartient à cette famille de composés exhibe d’intéressantes propriétés biologiques, notamment antivirales et antitumorales. Plus précisément elle inhibe la topoisomérase 2α, une enzyme ciblée par les chimiothérapies utilisées contre le cancer, et possède également une activité contre les filaments d’actine du cytosquelette. La structure particulièrement unique de la vescaline comporte un motif NonaHydroxyTriPhénoyle (NHTP) lié par une liaison C-arylglucosidique à un coeur D-glucose en forme ouverte. La synthèse totale de différents membres de cette classe de polyphénols d’origine végétale, dont celle de la vescaline, constituait l’objectif principal de cette thèse. Les voies d’accès à ces cibles exploitent en partie des méthodes développées précédemment lors de la synthèse totale de l’épipunicacortéine A 5-O-dégalloylée et sont complétées par de nouvelles méthodologies de synthèse. Ainsi, la méthode et le rendement de l’étape de C-arylglucosidation ont été améliorés et des conditions efficaces de couplage terarylique intramoléculaire entre un motif HexaHydroxyDiPhénoyle (HHDP) et une unité galloyle ont été élaborées. En adaptant la stratégie mise au point pour la synthèse totale de la vescaline, trois ellagitannins C-arylglucosidiques supplémentaires ont été préparés : la punicacortéine A, l’épipunicacortéine A et la castaline. / C-arylglucosidic ellagitannins are polyphenolic compounds biosynthesized through the secondary metabolism of various plants, in particular from the Fagaceae family such as oak and chestnut. Vescalin, which belongs to this class of plant polyphenols, displays interesting biological activities, with antiviral and antitumoral properties. More specifically, it inhibits topoisomerase 2α, a targeted enzyme in chemotherapy used in cancer treatment, and have also an activity against the cytoskeletal filamentous actin. Unique structure of vescalin displays a NonaHydroxyTriPhenoyl moiety (NHTP) linked to an open chain D-glucose with a C-arylglucosidic bond. The total synthesis of vescalin constitutes the main goal of this doctoral work. Synthetic routes employ in part chemical methods previously used for the total synthesis of 5-O-desgalloylepipunicacortein A in addition to new methodologies. Therefore, the C-arylglucosidation method and chemical yield have been improved and an efficient intramolecular terarylic coupling between a HexaHydroxyDiPhenoyl moiety (HHDP) and a galloyl unit has been developed. Taking advantage of the synthetic strategy elaborated for vescalin total synthesis, three additional C-arylglucosidic ellagitannins were obtained: punicacortein A, epipunicacortein A and castalin.
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Identificação de biomarcadores de exposição de compostos fenólicos degrumixama (Eugenia brasiliensis Lam.): Abordagem metabolômica / Biomarker exposure of phenolic compounds from grumixama (Eugenia brasiliensis Lam.) in healthy human model: Metabolomic approach.

Teixeira, Luciane de Lira 21 November 2016 (has links)
O consumo de frutas e verduras na dieta está associado à redução da incidência de doenças crônicas não transmissíveis entre eles câncer, síndrome metabólica e doenças cardiovasculares. A atividade biológica atribuída à ingestão desses alimentos é relacionada principalmente à presença de compostos bioativos, entre eles os compostos fenólicos, tais como flavonoides e elagitaninos. Contudo, a biodisponibilidade e a influência destes compostos no metabolismo humano não estão estabelecidas. Assim, o objetivo geral do presente estudo foi investigar as alterações no metaboloma humano decorrente da ingestão de uma fonte rica em compostos fenólicos, o suco da grumixama roxa (Eugenia brasiliensis Lam.), buscando identificar possíveis pontos de regulação do metabolismo. Para isto, a grumixama, variedades amarela e roxa, foram caracterizadas quanto ao seu perfil de compostos fenólicos e administradas na forma de suco, em dose única, a voluntários saudáveis. A grumixama roxa se mostrou rica em antocianinas e elagitaninos, principalmente cianidina 3-O-glicosídeo e a strictinina, respectivamente. Para o ensaio clínico, 15 voluntários saudáveis consumiram, em dose única, suco de grumixama roxa (10 ml de suco/kg de peso corporal). Amostras de plasma e urina foram coletadas em diferentes tempos durante 24 h após ingestão e analisados por CG-MS e LC-ESI-MS/MS. Os metabólitos exógenos excretados na urina foram identificados como urolitinas e ácidos fenólicos, derivados da degradação, principalmente, pela microbiota dos elagitaninos e das antocianinas, respectivamente. Quatro urolitinas (A, B, C e D) foram encontradas na urina, principalmente como metabólitos de fase II, detectados a partir de 4 h após a ingestão do suco com aumento na concentração observado até 24h. Além disso, quatro ácidos fenólicos foram identificados, destes o ácido hipúrico como majoritário. 114 metabólitos, entre eles, 17 aminoácidos, 47 ácidos orgânicos, 7 outras classes de compostos e 43 compostos desconhecidos foram identificados por CG-MS, para os tempos de coleta de urina antes da ingestão de suco de grumixama (T0) e para os períodos de 1-2 h e 2-4 h após a ingestão. A OPLS-DA foi utilizada para descriminar os metabólitos alterados pela ingestão de suco de grumixama. A análise das vias metabólicas mostrou que a ingestão do suco de grumixama influenciou principalmente em três vias metabólicas: metabolismo do glioxilato e dicarboxilato (up-regulated), da beta-alanina (down-regulated) e da fenilalanina (up-regulated), sendo essas direcionadas ao metabolismo energético. Além disso, os extratos de grumixama roxa e amarela também foram testados em modelo animal (camundongo C57BL/6J) de obesidade e resistência à insulina induzido por uma dieta rica em lipídeos e açúcares. O tratamento com os extratos, concomitante à dieta e durante 8 semanas, promoveu modulação significativa do metabolismo lipídico. Como conclusões, a grumixama roxa mostrou ser uma boa fonte de antocianinas e elagitaninos, e a interação entre metabólitos oriundos da ingestão do fruto e dos metabólitos endógenos podem estar relacionados com alterações nos metabolismos de aminoácidos e energético. No entanto, mais estudos são necessários para elucidar e validar as hipóteses geradas. / The fruits and vegetables intake has been associated to the reduction of chronic non-communicable disease incidence, such as cancer, metabolic syndrome and cardiovascular diseases. The biological activities attribute to them has been related mainly to the phenolic compounds, such as flavonoids and ellagitannins, presents in their composition. However, the bioavailability and influence of these compounds under human metabolism still unclear. Thus, the objective of the present study was investigate changes in human metaboloma as a result of the acute intake of the polyphenol-rich source from purple grumixama juice (Eugenia brasiliensis Lam.), searching to identify possible sites of metabolic regulation. In this way, purple and yellow grumixama varieties were characterized to polyphenol profile, and a single dose of the purple grumixama juice was administered to healthy human. The purple grumixama showed be a good source of anthocyanins and ellagitannins, mainly cyanidin 3-O-glucoside and strictinin, respectively. In the clinical trial, 15 healthy subjects intake a single dose of purple grumixama juice (10 ml of juice/kg of body mass). Plasma and urine samples were collected, before and after intake (over 24 h), and analyzed by GC-MS and LC-MS. The exogenous metabolites excreted and identified in urine samples by LC-MS were identified as urolithins and phenolic acids, gut microbiota catabolites of ellagitannins and anthocyanins, respectively. Four urolithins were detected beginning excretion 4 h after juice intake, increasing over 24 h. Furthermore, four phenolic acids were identified, being the hippuric acid the majority of them. 114 metabolites were identified to urine collection points before and after intake (1-2 h and 2-4 h) by CG-MS, being 17 amino acids, 7 other classes, 47 organic acids and 43 unknown compounds. A OPLS-DA discriminated the metabolites changed by the grumixama juice intake. The pathway analysis showed that juice intake influenced mainly three metabolic pathways: glyoxylate and dicarboxylate metabolism (up-regulated), beta-alanine metabolism (down-regulated), and phenylalanine metabolism (up-regulated), being these pathways related to energetic metabolism. Furthermore, the purple and yellow grumixama fruits extracts were evaluated in animal model of obesity and insulin resistance (C57BL/6J mice) induced by high fatty and high sugar diet. The treatment, during 8 weeks, promoted lipid metabolism modulation. As conclusions, purple grumixama showed to be a good source of anthocyanins and ellagitannins, and the interaction among the metabolites from fruits and endogenous metabolites can be related to changes in energetic metabolism and amino acid metabolism. However, more studies are necessary to elucidate and validate these hypotheses.
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Ellagotaniny - výskyt, metabolismus a účinky na lidský organismus / Ellagitannins -occurence, metabolism and effects on human body

Raabová, Karin January 2017 (has links)
CHARLES UNIVERSITY PHARMACEUTICAL FACULTY IN HRADEC KRÁLOVÉ DEPARTMENT OF PHARMACEUTICAL BOTANY AND ECOLOGY Title of the Diploma thesis: ELLAGITANNINS - OCCURENCE, METABOLISM AND EFFECTS ON HUMAN BODY Candidate: Bc. Karin Raabová Supervisor: PharmDr. Jana Karlíčková, Ph.D. Diploma thesis 2016/2017, pp. 77 Ellagitannins belongs to a class of hydrolysable tannins, which are susceptible to hydrolysis to give ellagic acid in the digestive tract. Ellagitannins occur in many plant families, for example plants in the family Rosaceae, Myrtaceae or Lythraceae. There are naturally found in some fruits (pomegranate, strawberries, blackberries, raspberries, grapes), but also in the seeds of walnuts and thus form a diverse group of bioactive polyphenols with anti-inflammatory, antitumor, antioxidant and antimicrobial activity. Special instrumental methods (HPLC, DAD, MS) are most often used for subsequent evidence of occurrence of these compounds in plants and their identification. This diploma thesis is a literature review, which aimed at processing the available knowledge about the ellagitannins. Attention was focused on the biological activity demonstrated in an animal or human organism. Keywords: ellagitannins, occurrence, metabolism, effects, human body
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Anti-Quorum Sensing Agents from South Florida Medicinal Plants and their Attenuation of Pseudomonas Aeruginosa Pathogenicity

Adonizio, Allison L. 25 March 2008 (has links)
With the difficulty in treating recalcitrant infections and the growing resistance to antibiotics, new therapeutic modalities are becoming increasingly necessary. The interruption of bacterial quorum sensing (QS), or cell-cell communication is known to attenuate virulence, while limiting selective pressure toward resistance. This study initiates an ethnobotanically-directed search for QS inhibiting agents in south Florida medicinal plants. Fifty plants were screened for anti-QS activity using two biomonitor strains, Chromobacterium violaceum and Agrobacterium tumefaciens. Of these plants, six showed QS inhibition: Conocarpus erectus L. (Combretaceae), Chamaecyce hypericifolia (L.) Millsp. (Euphorbiaceae), Callistemon viminalis (Sol.ex Gaertn.) G. Don (Myrtaceae), Bucida burceras L. (Combretaceae), Tetrazygia bicolor (Mill.) Cogn. (Melastomataceae), and Quercus virginiana Mill. (Fagaceae). These plants were further examined for their effects on the QS system and virulence of Pseudomonas aeruginosa, an intractable opportunistic pathogen responsible for morbidity and mortality in the immunocompromised patient. C. erectus, B. buceras, and C. viminalis were found to significantly inhibit multiple virulence factors and biofilm formation in this organism. Each plant presented a distinct profile of effect on QS genes and signaling molecules, suggesting varying modes of action. Virulence attenuation was observed with marginal reduction of bacterial growth, suggesting quorum quenching mechanisms unrelated to static or cidal effects. Extracts of these plants were also investigated for their effects on P. aeruginosa killing of the nematode Caenorhabditis elegans. Results were evaluated in both toxin-based and infection-based assays with P. aeruginosa strains PA01 and PA14. Overall nematode mortality was reduced 50-90%. There was no indication of host toxicity, suggesting the potential for further development as anti-infectives. Using low-pressure chromatography and HPLC, two stereoisomeric ellagitannins, vescalagin and castalagin were isolated from an aqueous extract of C. erectus. Structures were confirmed via mass spectrometry and NMR spectroscopy. Both ellagitannins were shown to decrease signal production, QS gene expression, and virulence factor production in P. aeruginosa. This study introduces a potentially new therapeutic direction for the treatment of bacterial infections. In addition, this is the first report of vescalagin and castalagin being isolated from C. erectus, and the first report of ellagitannin activity on the QS system.

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