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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.
51

Sistemática, evolução e biologia reprodutiva de Utricularia com ênfase para Utricularia amethystina Salzm. Ex A.St.-Hil. & Girard (Lentibulariaceae) /

Menezes, Cristine Gobbo. January 2015 (has links)
Orientador: Vítor Fernandes Oliveira de Miranda / Banca: Eduardo Custódio Gasparino / Banca: Davi Rodrigo Rossato / Banca: Welington Luiz Araújo / Banca: Maurício Bacci Júnior / Resumo: Utricularia L. é um gênero cosmopolita, ausente apenas nos desertos e regiões polares, rico em espécies e altamente polimórfico em hábitos, morfologia polínica, seminal e das armadilhas. Muitas espécies do gênero possuem genomas miniaturizados, resultado de uma drástica redução de regiões não-codificadoras, dentre outras características moleculares peculiares. Utricularia amethystina é descrita como uma das mais polimórficas espécies do gênero, possui um histórico taxonômico complexo (mais de 30 sinonímias) e distribuição ampla entre as Américas. Seu polimorfismo se reflete no tamanho da planta, tamanho e forma da corola, e também na pigmentação floral - U. amethystina pode apresentar flores púrpuras (em diferentes tonalidades), amarelas e brancas - dentre outras características. O polimorfismo da pigmentação floral pode afetar a interação com o polinizador e o fluxo gênico entre os morfotipos, sendo por este motivo alvo de nosso interesse. Exploramos se o polimorfismo em caracteres seminais estaria relacionado aos morfotipos florais e buscamos características úteis para a taxonomia U. amethystina e espécies próximas. Também descrevemos as estratégias reprodutivas de Utricularia, com ênfase nos polinizadores e estratégia de polinização de U. amethystina. Além disso, investigamos o fluxo gênico entre os morfotipos florais utilizando diferentes regiões do DNA cloroplastidial previamente reportados como ―barcodes‖. E exploramos a evolução das transições de cor de flores na família Lentibulariaceae e dos genes relacionados à via de síntese das antocianinas, a principal classe de pigmentos presentes em flores e frutos. Identificamos caracteres seminais úteis para a taxonomia de Utricularia e observamos alto polimorfismo intraespecífico em U. amethystina. Utricularia amethystina, é na verdade um complexo de espécies, dentre as quais é possível encontrar fluxo gênico entre morfotipos ... / Abstract: Utricularia L. is a cosmopolitan genus from Lentibulariaceae and the richest genus in species among the carnivorous plants. Its species are highly polymorphic in many traits such as habit, pollen, seed and trap morphology. Many species has a compact genome resulted from the deletion of non-coding regions, and other peculiar molecular features. Utricularia amethystina is described as one of the most polymorphic species in the genus, it has a complex taxonomic history and is found across the American continents. Its polymorphism is reflected on plant height, corolla's size and shape, and floral pigmentation - U. amethystina might show many shades of purple, yellow and white flowers. However, the most remarkable trait is the polymorphism on pigmentation of flowers, because it might undermine the pollinator attraction, and by this way interrupt the gene flow among its morphotypes. With this in mind, we have surveyed the seed traits, looking for characters useful for taxonomic purposes for U. amethystina and related species. The reproductive strategies found on the genus are also described, focusing on U. amethystina and describing its pollinator. We also have investigated the gene flow among the U. amethystina morphotypes based on barcodes regions from cpDNA. Besides this, were evaluated the evolution of genes related with the transitions on pigmentation of flowers of the Lentibulariaceae. We identified useful seed characters for the genus' taxonomy. U. amethystina is a complex with distinct lineages related one each other with high support from molecular survey with cpDNA, from which only two populations from different floral phenotypes (purple and white) were clustered in all analyses. Some lineages also showed evidences for positive selection on matK gene. The pigmentation evolution showed the expected pattern with purple flowers as the ancestral state from which the transitions occurred. We also observed that the transitions are ... / Doutor
52

Qualidade pós-colheita de camu-camu (Myrciaria dubia (H.B.K.) McVaugh) em diferentes estádios de maturação, submetidos à radiação gama e refrigeração / Postharvest quality of camu-camu (Myrciaria dubia (HBK) McVaugh) at different stages of maturation, submitted to gamma radiation and cooling

Igor Galvão Silva 31 July 2013 (has links)
Objetivou-se realizar a caracterização física, química e funcional do fruto de camu-camu classificados nos estádios 2 (verde-avermelhado) e 4 (roxo), utilizando-se distintas doses de radiação gama (0; 0,5; 1 kGy) e acompanhar a atividade respiratória dos frutos, monitorados por um período de 25 dias em dois níveis de temperatura (5 e 25 oC). Os frutos foram avaliados quanto à cor instrumental da casca, firmeza, sólidos solúveis, acidez, ratio, pH, antocianinas, compostos fenólicos, atividade antioxidante, atividade respiratória e teor de ácido ascórbico. A irradiação com dose de 0,5 kGy teve influência positiva nos frutos no estádio 2 armazenados em temperatura ambiente, prolongando seu tempo de vida útil em dois dias, totalizando 9 dias. Os frutos tratados com 1 kGy tiveram seu tempo de vida útil reduzido em 6 dias. Em relação à firmeza, o ponto de maturação teve grande influência nas respostas; comportamento semelhante aconteceu com as antocianinas, onde os frutos no estádio 4 tiveram valores até 10 vezes superiores aos frutos verde-avermelhado (estádio 2), mas, de forma geral, as antocianinas se mantiveram estáveis em relação às doses testadas e ao tempo de armazenamento. A dose de 1 kGy influenciou nos compostos antioxidantes dos frutos refrigerados, diminuindo 83,4 e 67,46% do teor para os frutos nos estádios 2 e 4, respectivamente. O ácido ascórbico no camu-camu se mostrou altamente estável, mesmo quando o fruto já estava impróprio para o consumo, apresentando valores acima de 1000 mg de ácido ascórbico 100 g-1 de fruto. Exceção foi para os frutos refrigerados tratados com 1 kGy, que apresentaram valores de 263,67 mg 100 g-1 para os frutos no estádio 2 e 626,1 mg 100 g-1 para os frutos no estádio 4. De forma geral, a refrigeração teve maior influência na conservação do camu-camu, aumentando em média 18 dias o seu armazenamento, a radiação gama nas doses estudadas não se mostrou um tratamento vantajoso para aumentar a vida útil do camu-camu refrigerado. O fruto do camu-camu apresentou baixos valores de ratio (índice de palatabilidade), o que faz do fruto não palatável para o consumo in natura, elevados teores de antocianinas, compostos fenólicos, atividade antioxidante e ácido ascórbico / The objective of this work was to characterize physical, chemical and functional of the camu-camu fruit in its 2 stage (green- reddish) and 4 (purple), using different doses of gamma radiation (0, 0.5, 1 kGy) and to keep up with the respiratory activity over a period of 25 days in two temperature levels (5 and 25 ºC). The fruits were evaluated when the instrumental color of skin, firmness, soluble solids, acidity, ratio, pH, anthocyanins, phenolic compounds, antioxidant, respiratory activity and ascorbic acid content. Irradiation with 0,5 kGy had a positive influence on the 2 stage fruits stored at room temperature, extending its lifetime two days, totaling nine days. The fruit treated with 1 kGy had its lifetime reduced by 6 days. About the firmness, the maturation point had great influence on the answers; responses similar happened with anthocyanins, where the purple fruits had values up to 10 times higher than the green-reddish fruits, but, in general, anthocyanins were stable in relation to the doses tested and the storage time. There was a decrease of antioxidants in 83,4 and 67,46% for 2 and 4stages fruits, respectively. Ascorbic acid in camu-camu was highly stable even when the fruit was already unfit for consumption, with values above 1000 mg ascorbic acid 100 g-1 fruit. There was an exception with the refrigerated fruits treated with 1 kGy, which showed values of 263,67 mg 100 g-1 for the 4 stage fruits and 626.1 mg 100 g-1 for the 2 stage fruits. In general, the cooling had a greater influence on the conservation of camu-camu, increasing on average 18 days your storage, the gamma radiation doses studied did not prove advantageous treatment to extend the lifetime of the camu-camu in refrigeration. The camu-camu fruit showed low values of ratio (index of palatability), which makes the fruit unsuitable for fresh consumption, high levels of anthocyanins, phenolic compounds, antioxidant activity and ascorbic acid
53

Filme biodegradável à base de fécula de mandioca como potencial indicador de mudança de pH. / Biodegradable film based on cassava starch as patential indicator of pH change.

Ana Maria Zetty Arenas 26 June 2012 (has links)
A cada dia é mais crescente a necessidade e interesse no desenvolvimento de embalagens competitivas e com maior valor agregado. Visando atender a necessidade de consumidores cada vez mais exigentes e preocupados com o meio ambiente, este trabalho propôs o uso do pigmento natural antocianina no desenvolvimento de filmes biodegradáveis para potencial uso como embalagem inteligente, indicadora de mudança de pH. Os filmes foram elaborados pela técnica de casting tendo como formulação base fécula de mandioca (Manihot esculenta Crantz), argila esmectita sódica, glicerol, etanol e água, e incorporados com duas concentrações de antocianina (0,05 e 0,10) g/100 g de solução filmogênica, e em uma segunda fase, ácido cítrico foi incorporado à matriz polimérica a fim de estudar a influência do pH da solução filmogênica (2,8 e 4,3) sobre o desempenho do filme empregado como embalagem. Os filmes foram avaliados quanto as suas propriedades mecânicas (resistência máxima à tração e porcentagem de elongação na ruptura), físico-químicas (atividade de água, umidade, espessura), de barreira (permeabilidade ao vapor dágua e ao oxigênio) e análise de mudança de cor. Em seguida à caracterização, a atividade indicadora de pH foi testada com peixe cru embalado em recipientes de vidro tampados com o filme. Os recipientes foram acondicionados em temperatura ambiente e sob três temperaturas distintas de refrigeração, sendo que recipientes vazios também fechados com o filme foram usados como controle. A avaliação da atividade indicadora de pH foi realizada por meio da análise de mudança de cor do filme correlacionada com o pH do peixe. Os resultados obtidos foram promissores, uma vez que os filmes avaliados se mostraram bons indicadores de pH, ao mudarem de cor à olho nu em resposta à variação do pH, sendo essa mudança mais acentuada em filmes com maior conteúdo de antocianina. / The interest and need for the development of more competitive, higher value-added packages grow faster each day. For attending the needs of a more demanding, environmentally-concerned group of consumers, the present work proposes the use of natural anthocyanin pigment for the development of biodegradable films to be used as intelligent packaging material capable of indicating pH change. These films, made by employing a technique known as casting, consist of a basic formulation of cassava starch (Manihot esculenta Crantz), sodium smectite clay, glycerol, ethanol, and water, combined with two concentrations of anthocyanin (0.05 and 0.10) g/100 g of a filmogenic solution. In a second phase, citric acid was added to the polymer matrix in order to study the influence of the filmogenic solution pH (2.8 and 4.3) on the packaging performance of the films. These materials were assessed according to their mechanical properties (tensile strength at break and elongation at break percentage), physical and chemical properties (water activity, moisture content and thickness), barrier properties (water vapor and oxygen permeability), and color change. After this characterization, the pH-indicating activity was tested with raw fish stored in glass containers sealed with the film. Such containers were firstly exposed to room temperature and subsequently to three different refrigeration temperatures. Similarly, some empty containers also sealed with the same film were used as control. The assessment of the pH-indicating activity was undertaken by analyzing the color change of the film correlated with the pH of the fish. Promising outcomes seemed to have been achieved, since the films that were assessed proved to be efficient pH indicators. The color change was visible to the naked eye in response to pH variation, and such a change was particularly strong in the films with higher anthocyanin content.
54

Aplicações analiticas e didaticas de antocianinas extraidas de frutas / Analytical and didactic applications of anthocyanins extracted from fruits

Terci, Daniela Brotto Lopes 29 November 2004 (has links)
Orientador: Adriana Vitorino Rossi / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-04T19:15:03Z (GMT). No. of bitstreams: 1 Terci_DanielaBrottoLopes_D.pdf: 9748228 bytes, checksum: 095885c9317fc4d1076392518f606434 (MD5) Previous issue date: 2004 / Doutorado / Quimica Analitica / Doutor em Quimica
55

Caracterização molecular da pigmentação dos filamentos da corona no gênero Passiflora (Passifloraceae) / Molecular characterization of the pigmentation of the corona filaments in Passiflora genus (Passifloraceae)

Aizza, Lilian Cristina Baldon, 1977- 24 August 2018 (has links)
Orientador: Marcelo Carnier Dornelas / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-24T15:53:22Z (GMT). No. of bitstreams: 1 Aizza_LilianCristinaBaldon_D.pdf: 13718851 bytes, checksum: 77a2cf61de6ab6044b8890c05167a53c (MD5) Previous issue date: 2014 / Resumo: Antocianinas são frequentemente responsáveis pela grande diversidade de cores encontrada em flores, frutos, sementes e folhas de angiospermas. Estes pigmentos têm uma função ecológica fundamental como discriminação visual na atração de animais para polinização e dispersão de sementes. Dada a importância da pigmentação floral na atração de polinizadores e visto que as flores de Passiflora são exuberantes devido à diversidade de coloração, foi de particular interesse neste estudo caracterizar a pigmentação na corona e identificar os genes envolvidos na biossíntese destes pigmentos. O perfil das antocianinas foi caracterizado por cromatografia líquida de ultra-eficiência acoplada à espectrometria de massas com ionização por electrospray (UPLC-ESI-MS/MS) nos filamentos da corona de P. edulis, P. alata, P. coccinea, P. incarnata, P. suberosa e do híbrido artificial P. `Lady Margaret¿. A diversidade de pigmentação observada nas espécies de Passiflora pode ser explicada pela combinação de moléculas de antocianinas específicas acumuladas nas células epidérmicas dos filamentos da corona. A morfologia celular da epiderme dos filamentos da corona em flores de Passiflora pode funcionar como guia visual e tátil para os polinizadores. Análises de bioinformática no banco de etiquetas de sequências expressas (ESTs) de Passiflora edulis e Passiflora suberosa (PASSIOMA) identificaram quinze genes de seis diferentes famílias gênicas envolvidas potencialmente na biossíntese de antocianina em Passiflora. As sequências putativas de aminoácidos codificadas pelos genes estudados juntamente com os seus possíveis homólogos em espécies conhecidas foram alinhadas e analisadas. A determinação da expressão temporal e espacial dos genes PeDFR, PeGT, PeWD40 e PsMYB-R2R3 pode contribuir para a compreensão dos mecanismos da biossíntese de antocianinas em Passiflora / Abstract: Anthocyanins are frequently responsible for most of the color diversity found in flowers, fruits, seeds and leaves of angiosperms. These pigments have a key ecological function as visual discrimination in animal attraction for pollination and seed dispersal. Given the importance of floral pigmentation in the attraction of pollinators and since the passionflowers are exuberant due to the great diversity in color it was of particular interest in this study to characterize the pigments present in the corona and identification of genes involved in the biosynthesis of these pigments in Passiflora. The anthocyanin profile was characterized by ultra performance liquid chromatography with electrospray ionization and tandem mass spectrometry (UPLC-ESI-MS/MS) in coronal filaments of P. edulis, P. alata, P. coccinea, P. incarnata, P. suberosa and of the artificial hybrid P. `Lady Margaret¿. The diversity of pigmentation observed in Passiflora species can be explained by the combination of different anthocyanin molecules accumulated in the epidermal and subepidermal cells of the corona filaments. The cell morphology of the epidermis of the corona filaments in flowers of Passiflora can function as a tactile and visual guide for pollinators. Bioinformatics analysis from the PASSIOMA database obtained from reproductive expressed sequence tags (ESTs) of Passiflora edulis and Passiflora suberosa identified fifteen genes from six different gene families potentially involved in the anthocyanin biosynthesis in Passiflora. The putative protein sequences encoded by studied genes together with possible homologs in known species were analyzed by sequence alignment. The determination of the temporal and spatial expression of PeDFR, PeGT, PeWD40 and PsMYB-R2R3 genes may contribute to understanding the mechanisms of anthocyanin biosynthesis in Passiflora / Doutorado / Biologia Vegetal / Doutora em Biologia Vegetal
56

Avaliação do efeito do pó liofilizado da casca de jabuticaba (Myrciaria jaboticaba (Vell.) Berg) sobre o estresse oxidativo, tratamento da obesidade e parâmetros de saúde in vivo / Effect of freeze-dried jaboticaba (Myrciaria jaboticaba (Vell.) Berg) peel on oxidative stress, treatment of obesity and health parameters in vivo

Lenquiste, Sabrina Alves, 1987- 19 August 2018 (has links)
Orientador: Mario Roberto Marostica Júnior / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-19T17:44:21Z (GMT). No. of bitstreams: 1 Lenquiste_SabrinaAlves_M.pdf: 1146475 bytes, checksum: 3b7f25b2155d7b54ff4652b672de9aff (MD5) Previous issue date: 2012 / Resumo: O objetivo do presente estudo foi avaliar o efeito da casca de jabuticaba liofilizada (CJL) adicionada à dieta hiperlipídica no desenvolvimento da obesidade, perfil lipídico e hormonal e resistência à insulina, bem como sobre a peroxidação lipídica e modulação das enzimas com atividade antioxidante. Para tanto, ratos Sprague-Dawley foram alimentados com dieta Controle, dieta hiperlipídica (HF) e dietas HF adicionadas de 1, 2 e 4% de CJL. Ingestão energética, ganho de peso e composição corporal, além de glicose sérica e perfil lipídico e hormonal foram determinados. A resistência à insulina (RI) foi determinada pelo Teste de Tolerância à Glicose (GTT), Teste de Tolerância à Insulina (ITT) e cálculo do indicador de HOMA-IR. Para avaliar o status antioxidante, os níveis de TBARS e isoprostanos, bem como as concentrações de glutationa total, glutationa redutase, glutationa peroxidase, catalase e superóxido dismutase foram mensuradas no plasma dos animais. No tecido hepático, foram mensurados os níveis de TBARS e hidroperóxidos. Todos os resultados foram submetidos ao teste estatístico de ANOVA e teste de Tukey (p<0,05). A CJL adicionada à dieta HF não reverteu o ganho de peso e não alterou o colesterol total, perfil hormonal e glicose sérica. Contudo, o consumo de 1, 2 e 4% de CJL reduziu significativamente a insulina sérica e o indicador de HOMA-IR nos animais experimentais. Além disso, os animais alimentados com 2% de CJL mostraram níveis de HDL-colesterol similares ao grupo Controle (aumento de 41,65% comparado com o grupo HF). No status antioxidante, a CJL adicionada à dieta HF não reverteu a peroxidação lipídica no plasma e fígado dos animais. Porém, os níveis das enzimas glutationa redutase, catalase e superóxido dismutase foram aumentadas no plasma dos animais. Assim, o consumo de CJL pode promover aumento do HDL-colesterol, melhorar a RI e modular positivamente a atividade dessas enzimas, promovendo aumento no potencial antioxidante e prevenindo o desenvolvimento de doenças cardiovasculares, diabetes melitos tipo 2 e outras doenças relacionadas com o estresse oxidativo / Abstract: The objective of this study was to evaluate the effect of freeze-dried jaboticaba peel (FJP) added to high-fat diet on the development of obesity, lipid and hormonal profile and insulin resistance, as on lipid peroxidation and modulation of enzymes with antioxidant activity. For this purpose, Sprague-Dawley rats were fed a control diet, high-fat control diet and high-fat diets added to 1, 2 and 4% of FJP. Energy intake, weight gain and body composition, as serum glucose, lipid and hormonal profile were determined. The Insulin Resistance (IR) was determined by glucose tolerance test (GTT), insulin tolerance test (ITT) and calculation of HOMA-IR index. To evaluate the antioxidant status, the levels of TBARS and isoprostane, well as the concentrations of total glutathione, glutathione reductase, glutathione peroxidase, catalase and superoxide dismutase were measured in plasma of animals. Levels of TBARS and hydroperoxides were measured in liver tissue. All results were submitted to statistical analysis ANOVA and Tukey's test (p<0.05). The FJP added to the diet did not reverse the weight gain and did not alter the total cholesterol, hormonal profile and serum glucose. However, consumption of 1, 2 and 4% FJP reduced serum insulin and HOMA-IR index of the experimental animals. In addition, animals fed with 2% FJP showed HDL-cholesterol levels similar to control group (increase 41.65% compared to HF group). In antioxidant status, the FJP added to HF diet did not reverse the lipid peroxidation in plasma and liver of animals. However, the levels of enzymes glutathione reductase, catalase and superoxide dismutase were increased in plasma of animals. Thus, the consumption of FJP can increases HDL-cholesterol, improvement insulin resistance and modulate positively the activity these enzymes, promoting an increase in antioxidant potential and preventing the development of cardiovascular diseases, type 2 diabetes mellitus and other diseases related with oxidative stress / Mestrado / Nutrição Básica Experimental e Aplicada à Tecnologia de Alimentos / Mestre em Alimentos e Nutrição
57

Estudo da interação do sistema purinérgico, colinérgico e funções cognitivas na demência esporádica do tipo alzheimer: os efeitos das antocianinas / Study of purinergic and cholinergic system and cognitive functions interaction in sporadic dementia of alzheimer type: effects of anthocyanins

Gutierres, Jessié Martins 27 March 2013 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Dementia is a brain disorder characterized by decline in several mental functions and results in deficits in memory functioning in a variety of cognitive tasks. Evidence has emerged showing that anthocyanins (ANT) possess antioxidant, vasodilator and neuroprotective properties, and more recently are able to improve memory. The aim of our study was to investigate the role of ANT on memory and relate these changes to the cholinergic and purinergic in a model of amnesia induced by scopolamine (SCO), in a model of sporadic dementia of the Alzheimer type (SDAT), induced by intracerebroventricular injection of streptozotocin (ICV-STZ). We used male adult rats, which were previously treated with an extract rich in ANT (200mg/kg) for seven days. For each study protocol, we used the same dose of ANT only varying the time of drug administration SCO ip (1mg/kg) and ICV-STZ (3mg/kg) specific to the models of amnesia and dementia, respectively. The results showed that pretreatment with ANT reversed the memory deficits in an amnesia model and also in the model of SDAT. Regarding the activity of AChE enzyme was observed a significant increase in SCO group accompanied by a decrease in the activity of Na+, K+-ATPase and Ca2+-ATPase, and these effects were prevented by ANT treatment. It was also observed an increase in NTPDase activity, decreased in ADA and 5'-NT activity from brain of animals injected with SCO, accompanied by a reduction in the ATP and adenosine levels, which can compromise the purinergic signaling. ANT treatment was able to prevent changes in NTPDase, ADA and 5 -NT. The ICV-STZ treated animals showed a high anxiogenic-like behavior and ANT treatment prevented this effect, indicating that it can be seen with anxiolytic properties molecules, as in vitro experiments demonstrated their affinity for the benzodiazepine site of GABAA receptors. The animals ICV-STZ treated showed marked increase in AChE activity and Ca2+-ATPase, and decreased activity of Na+, K+-ATPase, causing disturbances in electrolyte concentrations of Na+ and Ca2+ and this could lead to neuronal excitotoxic and increased activity AChE in SDAT, and these effects were prevented by administration of ANT. Moreover, both the density and immunoreactivity for 5'-NT was markedly reduced in animals ICV-STZ as compared with the group of -normal rats. In addition, ICV-STZ treatment showed a significant decrease in 5'-NT and NTPDase activity in a model of SDAT. In the hippocampus of ICV-STZ animals was found considerable increase in levels of ROS total, MDA and NOx, indicating marked oxidative stress, which could lead to a decrease in neuronal viability and NTPDase and 5'-NT activity, since they are linked to the cell membrane. In this context, we suggest that both cholinergic and purinergic systems can be regulated by ANT treatment, thus defining use of this compound as a new strategy to control the deterioration of memory in aging associated with these systems. / A demência é uma desordem cerebral caracterizada por um declínio em várias funções mentais e resulta em déficits no funcionamento da memória e em uma variedade de tarefas cognitivas. Evidências têm surgerido que as antocianinas (ANT) possuem propreidades antioxidantes, vasodilatadoras e neuroprotetoras, sendo capazes de melhorar a memória. O objetivo do nosso trabalho foi investigar o papel das ANT sobre a memória e, relacionar estas mudanças com o sistema colínergico e purinérgico em um modelo de amnésia induzido por escopolamina (SCO), em um modelo de demência esporádica do tipo Alzheimer (DAS), induzido por administração intracerebroventricular de streptozotocina (ICV-STZ). Foram utilizados ratos machos adultos, os quais foram tratados previamente com um extrado rico em ANT (200mg/kg) durante sete dias. Para cada protocolo de estudo, foi utilizada a mesma dose de ANT variando apenas o tempo de administração das drogas SCO ip (1mg/kg) e ICV-STZ (3mg/kg) especificas para aos modelos de amnésia e de demência, respectivamente. Os resultados obtidos demonstraram que o tratamento prévio de ANT reverteu déficits de memória no modelo de amnésia e no modelo de DAS. Em relação à atividade da enzima AChE foi observado um aumento significativo nos grupos SCO acompanhado por uma diminuição da atividade das enzimas Na+,K+-ATPase e Ca2+-ATPase, e estes efeitos foram prevenidos pelo tratamento com ANT. Foi também observado aumento na atividade da NTPDase, diminuição na atividade da ADA e 5 -NT no cérebro de animais injetados com SCO, acompanhado por uma redução nos niveis de ATP e adenosina, ao qual pode comprometer a sinalização purinérgica. E o tratamento com ANT impediu alterações na atividade destas enzimas. Os animais ICV-STZ tratados apresentaram elevado comportamento ansiogênico e o tratamento com ANT previniu este efeito, indicando que as ANT podem ser consideradas moléculas com propriedades ansiolíticas, uma vez que experimentos in vitro, mostraram sua afinidade pelo sítio benzodiazepínico de receptores GABAA. Os animais tratados com ICV-STZ apresentaram marcante elevação na atividade da AChE e Ca2+-ATPase, e redução na atividade da Na+,K+-ATPase, causando perturbações nas concentrações eletrolíticas de Na+ e de Ca2+ e isto poderia levar a excitotoxicidade neuronal e aumento na atividade da AChE na DAS, e estes efeitos foram prevenidos pela administração de ANT. Além disso, tanto a densidade como a immunorreatividade para a 5 -NT foi marcadamente reduzida em animais ICV-STZ em comparação com o grupo de ratos normais. Além disso, o tratamento com STZ mostrou uma diminuição significativa para a atividade da NTPDase e 5 -NT no modelo em animais ICV-STZ tratados. No hipocampo de animais ICV-STZ tratados foi encontrado uma elevação considerável nos níveis de ROS total, MDA e NOx, indicando marcante estresse oxidativo, que poderia levar a diminuição na viabilidade de neurônios e na atividade das enzimas NTPDase e 5 -NT, uma vez que elas estão ligadas a membrana celular. Neste contexto, podemos sugerir que tanto o sistema colinérgico como purinérgico podem ser regulados pelo tratamento com antocianinas, definindo assim, o uso deste composto como uma nova estratégia para controlar a deteriorização mnemônica no envelhecimento associado a esses dos sistemas.
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Etude des mécanismes réactionnels et des cinétiques de dégradation des anthocyanes dans un extrait d’Hibiscus sabdariffa L. / Study of reaction mechanisms and kinetics of degradation of anthocyanins in an extract of Hibiscus sabdariffa L.

Sinela, André Mundombe 16 December 2016 (has links)
Les calices séchés d’Hibiscus sabdariffa L. sont traditionnellement utilisés en Afrique pour la production de boissons par macération dans l’eau. Cette matière première, riche en anthocyanes, est aussi connue dans l’industrie agro-alimentaire comme source de colorants naturels. Toutefois, la couleur des extraits obtenus évoluent rapidement au cours du temps ce qui nuit au développement de ces produits. Afin de mieux caractériser et de mieux comprendre l’instabilité de la couleur, ce travail propose une étude cinétique et mécanistique de la dégradation des anthocyanes durant la conservation d’un extrait d’H. sabdariffa. La caractérisation biochimique de l’extrait a notamment permis d’identifier les polyphénols majoritaires (delphinidine 3-O-sambubioside Del-3Sb, cyanidine 3-O-sambubioside Cya-3Sb, acides caféoylquiniques) et à mis en évidence la présence de métaux connus comme potentiels catalyseurs d’oxydation (Fe, Cu, Mn). Les cinétiques de dégradation des anthocyanes dans l’extrait ont été suivies par CLHP-DAD entre 4 et 37°C pendant 60 j. Elles peuvent être représentées par un modèle d’ordre 1. La Del-3Sb (Ea= 90 kJ.mol-1) est plus sensible à l’augmentation de la température que la Cya-3Sb (Ea= 80 kJ.mol-1). L’influence de différents facteurs sur la dégradation des anthocyanes a été étudiée dans des solutions modèles simplifiées. La constante de vitesse de dégradation de la Del-3Sb en solution modèle contenant du Fe (III), Cu (II) et Mn (II) à des concentrations similaires à celles de l’extrait, est proche de celle mesurée dans l’extrait. Celle de la Cya-3Sb est 40 % plus faible que dans l’extrait. L’augmentation de la concentration en Fe de 1 à 13 mg.L-1 multiplie environ 3 fois les vitesses de dégradation des anthocyanes. L’ajout d’acide chlorogénique à une solution modèle contenant du Fe augmente la vitesse de dégradation de la Cya-3Sb de 42 %. Un effet inverse est observé dans le cas de Del-3Sb (diminution de 47%). La teneur en oxygène dissous n’a pas d’influence sur les vitesses de dégradation. Deux mécanismes de dégradation des anthocyanes ont été mis en évidence : le mécanisme de scission, représentant une voie minoritaire (10% des anthocyanes dégradés) avec production de phloroglucinaldéhyde, d’acide gallique (issu de Del-3Sb) et protocatéchique (issu de Cya-3Sb) et un mécanisme de condensation avec formation de polymères bruns qui est favorisé par l’augmentation de la concentration en Fe et le mélange Fe, Cu et Mn. Les conclusions de l’ensemble du travail aboutissent à des perspectives sur l’étude de l’impact d’autres composés présents dans l’extrait (sucres, acides aminés) ainsi qui l’identification et la quantification des polymères bruns. / Dried calyx of Hibiscus sabdariffa L. are traditionally used in Africa for beverage production by maceration in water. This raw material, rich in anthocyanins, is also known in the food industry as a source of natural dyes. However, the color of extracts obtained quickly changes over time which affects the development of these products. To better characterize and understand the instability of color, this work provides a mechanistic and kinetic study of the degradation of anthocyanins during the conservation of an extract from H. sabdariffa. Biochemical characterization of the extract allowed to identify predominant polyphenols (delphinidin 3-O-sambubioside Del-3Sb, cyanidin 3-O-sambubioside Cya-3Sb and caffeoylquinic acids) and highlighted the presence of metals known as potential oxidation catalysts (Fe, Cu, Mn). Kinetics of degradation of anthocyanins in the extract were followed by HPLC-DAD between 4 and 37 ° C for 60 days. It can be represented by a first order model. Del-3Sb (Ea = 90 kJ mol-1) is more sensitive to temperature increase than Cya-3Sb (Ea = 80 kJ.mol-1). Influence of different factors on the degradation of anthocyanins was studied in simplified model media. Rate constant of degradation (k) of Del-3Sb on model media containing Fe (III), Cu (II) and Mn (II) at similar concentrations to those of the extract was similar to that measured in the extract. For Cya-3Sb it was 40% lower than in the extract. Increasing Fe concentration of 1 to 13 mg.L 1 increased by about 3-fold the k of anthocyanins. Adding chlorogenic acid in a model media containing Fe increased k of Cya-3Sb 42%. Opposite effect was observed for Del-3Sb (47% decrease). Dissolved oxygen content has no influence on k of anthocyanins. Two mechanisms of degradation of anthocyanins have been identified: the scission mechanism, representing a minority pathway (10% of degraded anthocyanins) with production of phloroglucinaldehyde, gallic acid (from Del-3Sb) and protocatechuic (from Cya -3Sb). The other mechanism is condensation with formation of brown polymers, it is promoted by increasing of concentration of Fe was and mixture of Fe, Cu and Mn. Conclusions led to perspectives on study of impact of other compound in the extract (sugar, amino-acids) as well as identification and quantification of brown polymers.
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Železo-chelatační vlastnosti extraktů plodů z různých variet bezu černého / Iron-chelating properties of fruit extracts of various elderberries

Gorová, Barbora January 2017 (has links)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Candidate: Barbora Gorová Supervisor: Assoc Prof. Přemysl Mladěnka, Pharm.D., Ph.D. Title of thesis: Iron-chelating properties of fruit extracts of various elderberries Inorganic iron is the major food source of iron in humans. It plays role in many biochemical reactions. Thus, iron metabolism disorders can lead to different diseases associated with lack of iron or iron overload. One of the possible treatment modalities of the latter represents the administration of iron chelators. Elderberry, Sambucus nigra L. (Adoxaceae), has been used in traditional medicine. The fruits of elderberry are a rich source of cyanidin-based anthocyanins as the main component. There are important differences, both in chemical and physical properties between several cultivars of elderberry. Anthocyanins might interact with metals in the gastrointestinal tract by formation of chelates. However, data on metal interactions with anthocyanins are sparse. The main aim of this study was to perform the analysis of interaction of iron with elderberry fruit extracts as a rich and cheap source of anthocyanins with cyanidin as the aglycon. In this in vitro study ten elderberry fruit exctracts were tested for iron chelating activities...
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Regulation of anthocyanin metabolism in grape : Effect of light on teinturier cultivars / Régulation du métabolisme des anthocyanes chez la vigne : Effet de la lumière sur des cépages teinturiers

Guan, Le 18 December 2014 (has links)
Les anthocyanes constituent une composante importante de la qualité des fruits rouges, particulièrement pour le raisin noir, et pour la couleur des vins qui en dérivent. La biosynthèse des anthocyanes est déterminée par des facteurs génétiques et affectée par des facteurs environnementaux, notamment la lumière. Pour la plupart des cépages, la pellicule des baies est le tissu principal ou exclusif accumulant les anthocyanes. Notre travail analyse les effets de la lumière et du génotype sur la biosynthèse des anthocyanes. Le matériel végétal que nous avons utilisé était constitué de cépages teinturiers, qui accumulent des anthocyanes dans la pellicule et dans la pulpe, et de populations hybrides. Dix-neuf anthocyanes mono-glycosylées ont été identifiés dans sept tissus colorés du cépage teinturier Yan-73 (V. vinifera). La composition et la concentration en anthocyanes varient selon les organes et le stade de développement. Les anthocyanes de la pellicule incluent principalement les dérivés de la malvidine, alors que les dérivés de la péonidine sont les plus abondants dans la pulpe. Les dérivés de malvidine et de péonidine prédominent dans le rachis, les pédicelles des baies, les limbes foliaires, les nervures et les pétioles, et dans l‘écorce à la base du cep. Les concentrations des anthocyanes dans les pellicules, la pulpe, le rachis et les pédicelles augmentent rapidement à partir de la véraison, ou une semaine après la véraison. Elles sont élevées dans les limbes foliaires jeunes et sénescents, et faibles dans les feuilles en expansion et les feuilles adultes. Elles ne varient pas beaucoup au cours de la saison dans les nervures et les pétioles, ou dans l‘écorce. Les cépages ont pu être distingués selon leur réponse à des traitements d‘exclusion de la lumière imposés de la nouaison à la maturité en entourant les grappes par des boîtes opaques. Le cépage non teinturier ―Gamay‖ à peau rouge accumule très peu d‘anthocyanes dans la pellicule en absence de lumière. Au contraire, les cultivars teinturiers, ‗Yan-73‘ et ‗Gamay Fréaux‘ (mutant teinturier de ‘Gamay’) accumulent des anthocyanes aussi bien dans la pellicule que dans la pulpe et présentent une coloration sombre même en absence de lumière... / Anthocyanins are an important component of red fruit quality, especially for grape berries, and for the color of the wines made from these berries. Anthocyanin biosynthesis is determined by genetic factors and affected by environmental factors, especially sunlight. For most grape cultivars, the berry skin is the main or only tissue accumulating anthocyanins. The present work investigates the effects of light and grape genotype on anthocyanin biosynthesis. We used teinturier grape cultivars (also called dyers, which synthesize anthocyanins in both skin and pulp) and its hybrid population as plant materials. Nineteen monoglucoside anthocyanins were identified in seven colored tissues of the teinturier cultivar Yan-73 (V. vinifera). Anthocyanin composition and concentration varied among grape organs and with developmental stage. Skin anthocyanins were mainly composed of malvidin derivatives, while peonidin derivatives were the most abundant anthocyanins in the pulp. Both malvidin and peonidin derivatives were predominant in rachis, berry pedicels, leaf lamina, vein and petioles, and living bark at the base of the shoot. The concentration of anthocyanins in berry skin, pulp, rachis and pedicels rapidly increased starting from veraison on, or one week after veraison. Anthocyanin concentrations were high in young and senescing leaf lamina and low in expanding and mature lamina. They did not vary much throughout the growing season in the leaf veins and petiole tissues, or in the bark. Grape cultivars could be distinguished by their response to sunlight exclusion treatments imposed from fruit set to maturity by surrounding the clusters with opaque boxes. The red-skinned non-teinturier cultivar Gamay could barely accumulate anthocyanins in berry skin under sunlight exclusion. In contrast, teinturier cultivars, Yan-73 and Gamay Fréaux (teinturier mutant of Gamay) accumulated anthocyanins in both skin and pulp and showed dark color even under sunlight exclusion...

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