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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.
91

Antioxidační aktivita vybraných druhů drobného ovoce / The antioxidant activity of selected species of small fruit

Křenová, Alena January 2015 (has links)
This diploma´s thesis deals with the determination of total antioxidant activity of red and white gooseberries and red, white and black currants. There are available information about small fruits, an overview of natural and synthetic antioxidants and a summary of the methods to determine the total antioxidant activity in the theoretical part. Frozen fruit samples were provided by Research and Breeding Institute of Pomology Holovousy Ltd. in the project QI111A141 – Research of new technologies in the cultivation of gooseberries and currants with a focus on quality and use of fetuses (Ministry of Agriculture). The total antioxidant activity of red and white gooseberries and currants was measured by spectrophotometric methods using free radicals ABTS•+ and DPPH and was expressed as a Trolox equivalent. The total antioxidant activity of black currants was measured by electron paramagnetic resonance using free radicals ABTS•+ and DPPH and expressed as a TEACABTS and a TEACDPPH. There were measured 8 species of red gooseberries, 6 species of white gooseberries, 12 species of red currants, 6 species of white currants and 8 species of black currants in this thesis. The highest values of total antioxidant activity showed species of red and white gooseberries Alan, Karmen, Pax and Invicta and species of red and white currants Rovada, Orion and Olin. Among black currants, species Ometa and Ruben had the highest values of total antioxidant activity.
92

Stanovení vybraných chemických parametrů v plodech nových odrůd rybízů / Determination of selected chemical parameters of fruit of new currant varieties

Pelikánová, Blanka January 2014 (has links)
Presented diploma thesis is dedicated to the determination of selected chemical parameters of fruits of new currant varieties. The theoretical part is focused on the characteristics of currant, the biologically active substances of its fruits and also the utilization of current in the food industry. Further part of the theory deals with the main chemical parameters which were examined: polyphenols, anthocyanins, ascorbic acid and antioxidant activity. In the practical part there were determined selected chemical parameters in six white, twelve red and thirteen black varieties of currant. Anthocyanins and polyphenols have been determined spectrophotometrically. The content of ascorbic acid in selected varieties of currant was determined by HPLC. As a technique for the determinationof the antioxidant activity was selected the method of free radical DPPH.
93

Исследование антирадикальной активности природных и синтетических антиоксидантов методом ЭПР-спектроскопии : магистерская диссертация / Research of antiradical activity of natural and synthetic antioxidants by EPR spectroscopy

Вежливцев, Е. А., Vezhlivtsev, E. A. January 2016 (has links)
Вещества, обладающие антирадикальной активностью (АРА) играют ведущую роль в системе защиты организма от свободных радикалов. Общие недостатки известных способов оценки АРА выражаются в том, что измерения проводятся непрямыми методами, что затрудняет количественно оценивать содержание веществ с антирадикальными свойствами. Результаты измерений представляются в относительных единицах, в качестве эталонных веществ чаще всего используются: тролокс, галловая и аскорбиновая кислоты, проявляющие разную АРА, что не позволяет сравнивать результаты между собой. Таким образом, существует необходимость в разработке прямого, безэталонного метода оценки антирадикальной активности. Одним из потенциально возможных решений данной проблемы является метод ЭПР-спектроскопии на модели 2,2-дифенил-1-пикрилгидразил. Цель и задачи исследования. Исследование безэталонным методом оценки антирадикальной активности природных и синтетических антиоксидантов на модели 2,2-дифенил-1-пикрилгидразил с использованием ЭПР-спектроскопии. Отработка методики определения антирадикальной активности на модели ДФПГ методом ЭПР-спектроскопии. Получение и анализ значений антирадикальной активности для ряда веществ с антирадикальными свойствами. Сравнение с результатами полученными методом потенциометрического определения антиоксидантной активности с использованием медиаторной системы. Полученные результаты. Установлены оптимальные условия для проведения анализа. Проведено исследование - новым, безэталонным методом оценки антирадикальной активности, ряда природных и синтетических антиоксидантов. Установлены значения антирадикальной активности ряда природных и синтетических антиоксидантов. Рассмотрены различные варианты механизмов ингибирования свободных радикалов и их зависимость от структуры антиоксиданта. / Substances with anti-radical activity (ARA) play a leading role in the body's defense system against free radicals. General disadvantages of the known methods of evaluating the APA expressed in the fact that measurements are carried out by indirect methods, making it difficult to quantify the content of substances with antiradical properties. The measurement results are presented in relative units, as reference substances are most often used: Trolox, ascorbic and gallic acid, exhibit different ARA, which does not allow to compare the results with each other. Thus, there is a need to develop direct, reference-free method of evaluating anti-radical activity. One possible solution to this potential problem is the method of EPR model 2,2-diphenyl-1-picrylhydrazyl. The purpose and objectives of the study. Study standardless method for assessing the antiradical activity of natural and synthetic antioxidants model 2,2-diphenyl-1-picrylhydrazyl using EPR spectroscopy. Testing methods for determining the anti-radical activity in the DPPH model EPR spectroscopy. Obtaining and analyzing anti-radical activity values for a number of substances with antiradical properties. Comparison with the results obtained by potentiometric determination of antioxidant activity using a mediator system Results. The optimum conditions for analysis. The research - the new reference-free method of evaluating anti-radical activity, a number of natural and synthetic antioxidants. Established values antiradical activity of natural and synthetic antioxidants. Various embodiments of the mechanisms of inhibition of free radicals and their antioxidant dependency structure.
94

Análise química e avaliação das atividades biológicas e comportamentais de extratos de frutas ricas em compostos fenólicos (mirtilo e amora-preta) / Chemical analysis and evaluation of the biological and behavioral activities of extracts of fruits rich in phenolic compounds (Blueberry and blackberry)

Ramirez, Maria Rosana January 2008 (has links)
O presente estudo teve como objetivos: determinar o teor dos polifenóis: flavonóides e antocianos totais presentes nos extratos de mirtilo (Vaccinium ashei) e amora preta (Rubus sp) por espectrofotometria; desenvolver e validar uma metodologia analítica para a caracterização dos extratos por cromatografia líquida de alta eficiência (CLAE), identificar, isolar e quantificar os principais compostos; avaliar a atividade anticolinesterásica, antioxidante frente à difenilpicrilhidrazol (DPPH) e anti-quimiotática in vitro; realizar a dosagem de aminas biogênicas no cérebro, investigar as possíveis atividades antinociceptiva, antiinflamatória, antiepiléptica, cognitiva e neuroprotetora do extrato de Vaccinium ashei, e o efeito neuroprotetor de um composto isolado a partir de Rubus: a cianidina, em vários modelos experimentais in vivo, em ratos e camundongos. Os perfis cromatográficos apresentaram compostos comuns às duas amostras; onde foram identificados 4 flavonóides, sendo hiperosídeo, quercitrina e isoquercitrina comuns a ambos extratos, e a rutina confirmada apenas em Rubus. Cinco antocianidinas foram identificadas em Vaccinium: delfinidina, cianidina, petunidina, peonidina e malvidina, e a cianidina em Rubus. Os resultados demonstraram, diferenças nas quantidades totais de polifenóis, flavonóides e antocianos. Todos os extratos, apresentaram atividade seqüestradora do radical DPPH in vitro. A atividade antiquimiotática in vitro foi comprovada para a fração flavonoídica. Os ensaios biológicos realizados in vivo demonstraram que o extrato preparado a partir de uma mistura de diferentes cultivares de Vaccinium ashei apresentou efeitos antinociceptivos nos testes da formalina sub-plantar, contorções abdominais, placa quente e tail flick. Produziu também efeito neuroprotetor, avaliado pelo ensaio cometa e pelo método de TOSC. Também causou aumento da atividade locomotora, assim como exerceu um efeito ansiolítico em roedores adultos. Facilitou a memória de curta duração e a Memória de longa duração e produziu um aumento de 5-HT no estriado e hipocampo de ratos adultos. Foi observado também que a cianidina isolada exerceu atividade neuroprotetora conforme avaliado pelo método de TOSC em ratos adultos. Não foram observadas diferenças significativas no modelo de epilepsia, entre o grupo tratado e o grupo controle, assim como não foram detectadas alterações no sistema dopaminérgico. Em síntese, os dados analisados em conjunto, permitem sugerir que o extrato de Vaccinium ashei e compostos isolados a partir de Rubus sp., como a cianidina, apresentam importante efeito neuroprotetivo, antinociceptivo e cognitivo, e nesta ação está envolvida a participação direta ou indireta dos receptores serotonérgico, acetilcolinérgicos, opióides e de citocinas pró-inflamatórias. Neste sentido, foram obtidos avanços significativos acerca dos mecanismos de ação de ambos gêneros o que torna o seu extrato e seus princípios ativos interessantes para o aproveitamento e desenvolvimento de novos alimentos funcionais e/ou nutracêuticos. / The objectives of this study were: comparing total phenolics, total anthocyanins and antioxidant capacity in appropriate berry samples from selected cultivars of the Vaccinium ashei and Rubus. A reliable HPLC procedure for determining the profile, quantifying and isolating of major compounds present in the extracts have been developed. The potential effects of the extracts were observed by chemotaxis assay, by acetilcholinesterasic inhibition, and their antioxidant properties evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) in vitro. Otherwise, we examined the antinociceptive, antiinflammatory, cognitive, anti-epileptic and neuroprotective effects of the extract of Vaccinium ashei in several experimental models in vivo, as well as biogenic amine concentration, in specific brain regions in rats and mice. In addition, it was tested the efficacy of oral administration of cyanidin-3-glucoside extracted from Rubus sp. in lipid peroxidation in brain rats (TOSC). An HPLC method for the analysis of anthocyanidins and flavonoids in berries extracts have been developed. The data obtained show that various compounds are common in the fruits analyzed, and four flavonoids were identified: hyperoside, quercetrin and isoquercitrin occurring in both fruits, and rutin occurring only in Rubus. Five anthocyanidins were identified in Vaccinium: delphinidin, cyanidin, peonidin, petunidin, and malvidin, and in Rubus cyanidin 3-glucoside was the major anthocyanin. We found that the flavonoids fractions significantly have inhibited migration celullar and acetilcholynestarase, and both total extract and fractions exhibited strong antioxidant activity. The extract (a mixture from the different cultivars) significantly enhanced short and long-term memory in the inhibitory avoidance task, induced an increase in the number of crossings during open field habituation, and had an anxiolytic effect in the elevated plus-maze task. These processes are accompanied by alterations in serotonin (5-HT) in the striatum, and the hippocampus. Cyanidin 3-glucoside isolated significantly reduced lipid peroxidation in hippocampal tissue in rats. In conclusion, the data from the current study show that the Vaccinum extract produce an important neuroprotective, cognitive and antinociceptive effect, which could be related with a direct or indirect interaction with the serotonergic, cholinergic, opioids receptors and pro-inflammatory cytokines. On the other hand, the extract don’t have protected the pentilenotetrazole-induced convulsions in mice, or influenced the memory retention in old rats when accessed in the step-down inhibitory avoidance, and showed no anxiolytic action in an elevated plus maze. The Vaccinium ashei extract did not alter locomotor activity, and the dopamine concentration in adult or old rats.
95

Determinação de atividade antioxidante, compostos fenólicos totais e teor de resveratrol em cinco cultivares brasileiras de Arachis hypogaea L. com a utilização de duas metodologias extrativas / Determination of antioxidant activity total phenolic cultivars of Arachis hypogaea using two extraction methods

Gabriel Casimiro Lopes Silva Santos 25 February 2013 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O amendoim A. hypogaea L. é a quarta oleaginosa mais consumida no mundo e suas sementes são altamente energéticas, com grandes quantidades de lipídios, proteínas, vitaminas e carboidratos. Diversas atividades farmacológicas já foram observadas em extratos de raízes, folhas e sementes, sendo a principal delas a atividade antioxidante. Neste trabalho, foi realizada a comparação entre duas metodologias (por maceração e assistida por micro-ondas) para a extração de compostos antioxidantes, incluindo o resveratrol. Também foi realizada a comparação entre extratos de diferentes órgãos de cultivares brasileiras (IAC 886, IAC Caiapó, IAC Tatu ST, IAC 8112 e IAC 99-1) quanto à atividade antioxidante, por DPPH, ao teor de compostos fenólicos, por Folin-Ciocalteu, e ao teor de resveratrol, por HPLC. Por fim, foram estabelecidos protocolos de cultura de tecidos para explantes de sementes, visando à produção de calos e plantas in vitro para posterior dosagem de compostos de interesse, tendo em vista a possibilidade de modulação das condições in vitro. As melhores condições determinadas para a extração por maceração de antioxidantes de A. hypogaea foram 80% de etanol em água como solvente, trituração com almofariz e pistilo, 50 mL solvente por grama de material vegetal seco, 120 minutos de incubação e dois estágios de extração. As melhores condições para a extração de resveratrol assistida por micro-ondas foram o uso de 37 mL de solvente/g material vegetal seco, com agitação de 1200 rpm por 15 minutos, a 37C. De uma maneira geral, os extratos de raízes e oriundos de micro-ondas apresentaram maior atividade antioxidante (até 92,36 2,71%), teor de compostos fenólicos (até 54,15 1,39 mg EAG/g extrato) e teor de resveratrol (até 1,614 0,356 mg/g extrato). Dentre as cultivares estudadas, IAC Tatu e IAC 99-1 foram as que apresentaram os teores mais elevados. Brotos e calos friáveis foram obtidos a partir de cotilédones, eixos embrionários e folíolos embrionários cultivados em meios suplementados com BAP e picloram, respectivamente. / Peanut A. hypogaea L. is the fourth most consumed oleaginous in the world and its seeds are high energetic, with high amounts of lipides, proteins, vitamins and carbohidrates. Several pharmacological activities have been observed in extracts of roots, leaves and seeds, especially an antioxidant activity. In this work, the comparison between two extraction methodologies (by maceration and microwave assisted extraction) for the extraction of antioxidant compounds, including resveratrol, was studied. We also carried out a comparison between extracts from different organs of Brazilian cultivars (IAC 886, IAC Caiapó, Tatu ST IAC, IAC 8112 and IAC 99-1) for antioxidant activity by DPPH, the content of phenolic compounds by Folin-Ciocalteu and the resveratrol content by HPLC. Finally, we established tissue culture protocols for seed explants, aiming at the production of in vitro plant material for future measurement of compounds of interest in the view of possible modulation of in vitro conditions. The best conditions for the extraction of antioxidant from A. hypogaea compounds by maceration were 80% of ethanol in water as a solvent, trituration by mortar and pestle, 50 mL solvent/g dry plant, 120 minutes of incubation and two stages of extraction. The best conditions for the extraction of resveratrol assisted by micro-wave were the use of 37 mL of solvent for each gram of dry plant, with 1200 rpm of agitation for 15 minutes, with 37oC. In general, root extracts and assisted by microwave showed higher antioxidant activity (until 92,36 2,71%), phenolic (untill 54,15 1,39 mg AGE/g extract) and resveratrol content (untill 1,614 0,356 mg/g extract). Among the studied cultivars, IAC Tatu and IAC 99-1 showed the best results. In tissue culture, shoots and friable calli were obtained from cotiledons, embryonic axis and embryonic leaflet cultured in media supplemented with BAP and picloram, respectively.
96

Análise química e avaliação das atividades biológicas e comportamentais de extratos de frutas ricas em compostos fenólicos (mirtilo e amora-preta) / Chemical analysis and evaluation of the biological and behavioral activities of extracts of fruits rich in phenolic compounds (Blueberry and blackberry)

Ramirez, Maria Rosana January 2008 (has links)
O presente estudo teve como objetivos: determinar o teor dos polifenóis: flavonóides e antocianos totais presentes nos extratos de mirtilo (Vaccinium ashei) e amora preta (Rubus sp) por espectrofotometria; desenvolver e validar uma metodologia analítica para a caracterização dos extratos por cromatografia líquida de alta eficiência (CLAE), identificar, isolar e quantificar os principais compostos; avaliar a atividade anticolinesterásica, antioxidante frente à difenilpicrilhidrazol (DPPH) e anti-quimiotática in vitro; realizar a dosagem de aminas biogênicas no cérebro, investigar as possíveis atividades antinociceptiva, antiinflamatória, antiepiléptica, cognitiva e neuroprotetora do extrato de Vaccinium ashei, e o efeito neuroprotetor de um composto isolado a partir de Rubus: a cianidina, em vários modelos experimentais in vivo, em ratos e camundongos. Os perfis cromatográficos apresentaram compostos comuns às duas amostras; onde foram identificados 4 flavonóides, sendo hiperosídeo, quercitrina e isoquercitrina comuns a ambos extratos, e a rutina confirmada apenas em Rubus. Cinco antocianidinas foram identificadas em Vaccinium: delfinidina, cianidina, petunidina, peonidina e malvidina, e a cianidina em Rubus. Os resultados demonstraram, diferenças nas quantidades totais de polifenóis, flavonóides e antocianos. Todos os extratos, apresentaram atividade seqüestradora do radical DPPH in vitro. A atividade antiquimiotática in vitro foi comprovada para a fração flavonoídica. Os ensaios biológicos realizados in vivo demonstraram que o extrato preparado a partir de uma mistura de diferentes cultivares de Vaccinium ashei apresentou efeitos antinociceptivos nos testes da formalina sub-plantar, contorções abdominais, placa quente e tail flick. Produziu também efeito neuroprotetor, avaliado pelo ensaio cometa e pelo método de TOSC. Também causou aumento da atividade locomotora, assim como exerceu um efeito ansiolítico em roedores adultos. Facilitou a memória de curta duração e a Memória de longa duração e produziu um aumento de 5-HT no estriado e hipocampo de ratos adultos. Foi observado também que a cianidina isolada exerceu atividade neuroprotetora conforme avaliado pelo método de TOSC em ratos adultos. Não foram observadas diferenças significativas no modelo de epilepsia, entre o grupo tratado e o grupo controle, assim como não foram detectadas alterações no sistema dopaminérgico. Em síntese, os dados analisados em conjunto, permitem sugerir que o extrato de Vaccinium ashei e compostos isolados a partir de Rubus sp., como a cianidina, apresentam importante efeito neuroprotetivo, antinociceptivo e cognitivo, e nesta ação está envolvida a participação direta ou indireta dos receptores serotonérgico, acetilcolinérgicos, opióides e de citocinas pró-inflamatórias. Neste sentido, foram obtidos avanços significativos acerca dos mecanismos de ação de ambos gêneros o que torna o seu extrato e seus princípios ativos interessantes para o aproveitamento e desenvolvimento de novos alimentos funcionais e/ou nutracêuticos. / The objectives of this study were: comparing total phenolics, total anthocyanins and antioxidant capacity in appropriate berry samples from selected cultivars of the Vaccinium ashei and Rubus. A reliable HPLC procedure for determining the profile, quantifying and isolating of major compounds present in the extracts have been developed. The potential effects of the extracts were observed by chemotaxis assay, by acetilcholinesterasic inhibition, and their antioxidant properties evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) in vitro. Otherwise, we examined the antinociceptive, antiinflammatory, cognitive, anti-epileptic and neuroprotective effects of the extract of Vaccinium ashei in several experimental models in vivo, as well as biogenic amine concentration, in specific brain regions in rats and mice. In addition, it was tested the efficacy of oral administration of cyanidin-3-glucoside extracted from Rubus sp. in lipid peroxidation in brain rats (TOSC). An HPLC method for the analysis of anthocyanidins and flavonoids in berries extracts have been developed. The data obtained show that various compounds are common in the fruits analyzed, and four flavonoids were identified: hyperoside, quercetrin and isoquercitrin occurring in both fruits, and rutin occurring only in Rubus. Five anthocyanidins were identified in Vaccinium: delphinidin, cyanidin, peonidin, petunidin, and malvidin, and in Rubus cyanidin 3-glucoside was the major anthocyanin. We found that the flavonoids fractions significantly have inhibited migration celullar and acetilcholynestarase, and both total extract and fractions exhibited strong antioxidant activity. The extract (a mixture from the different cultivars) significantly enhanced short and long-term memory in the inhibitory avoidance task, induced an increase in the number of crossings during open field habituation, and had an anxiolytic effect in the elevated plus-maze task. These processes are accompanied by alterations in serotonin (5-HT) in the striatum, and the hippocampus. Cyanidin 3-glucoside isolated significantly reduced lipid peroxidation in hippocampal tissue in rats. In conclusion, the data from the current study show that the Vaccinum extract produce an important neuroprotective, cognitive and antinociceptive effect, which could be related with a direct or indirect interaction with the serotonergic, cholinergic, opioids receptors and pro-inflammatory cytokines. On the other hand, the extract don’t have protected the pentilenotetrazole-induced convulsions in mice, or influenced the memory retention in old rats when accessed in the step-down inhibitory avoidance, and showed no anxiolytic action in an elevated plus maze. The Vaccinium ashei extract did not alter locomotor activity, and the dopamine concentration in adult or old rats.
97

Determinação de atividade antioxidante, compostos fenólicos totais e teor de resveratrol em cinco cultivares brasileiras de Arachis hypogaea L. com a utilização de duas metodologias extrativas / Determination of antioxidant activity total phenolic cultivars of Arachis hypogaea using two extraction methods

Gabriel Casimiro Lopes Silva Santos 25 February 2013 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O amendoim A. hypogaea L. é a quarta oleaginosa mais consumida no mundo e suas sementes são altamente energéticas, com grandes quantidades de lipídios, proteínas, vitaminas e carboidratos. Diversas atividades farmacológicas já foram observadas em extratos de raízes, folhas e sementes, sendo a principal delas a atividade antioxidante. Neste trabalho, foi realizada a comparação entre duas metodologias (por maceração e assistida por micro-ondas) para a extração de compostos antioxidantes, incluindo o resveratrol. Também foi realizada a comparação entre extratos de diferentes órgãos de cultivares brasileiras (IAC 886, IAC Caiapó, IAC Tatu ST, IAC 8112 e IAC 99-1) quanto à atividade antioxidante, por DPPH, ao teor de compostos fenólicos, por Folin-Ciocalteu, e ao teor de resveratrol, por HPLC. Por fim, foram estabelecidos protocolos de cultura de tecidos para explantes de sementes, visando à produção de calos e plantas in vitro para posterior dosagem de compostos de interesse, tendo em vista a possibilidade de modulação das condições in vitro. As melhores condições determinadas para a extração por maceração de antioxidantes de A. hypogaea foram 80% de etanol em água como solvente, trituração com almofariz e pistilo, 50 mL solvente por grama de material vegetal seco, 120 minutos de incubação e dois estágios de extração. As melhores condições para a extração de resveratrol assistida por micro-ondas foram o uso de 37 mL de solvente/g material vegetal seco, com agitação de 1200 rpm por 15 minutos, a 37C. De uma maneira geral, os extratos de raízes e oriundos de micro-ondas apresentaram maior atividade antioxidante (até 92,36 2,71%), teor de compostos fenólicos (até 54,15 1,39 mg EAG/g extrato) e teor de resveratrol (até 1,614 0,356 mg/g extrato). Dentre as cultivares estudadas, IAC Tatu e IAC 99-1 foram as que apresentaram os teores mais elevados. Brotos e calos friáveis foram obtidos a partir de cotilédones, eixos embrionários e folíolos embrionários cultivados em meios suplementados com BAP e picloram, respectivamente. / Peanut A. hypogaea L. is the fourth most consumed oleaginous in the world and its seeds are high energetic, with high amounts of lipides, proteins, vitamins and carbohidrates. Several pharmacological activities have been observed in extracts of roots, leaves and seeds, especially an antioxidant activity. In this work, the comparison between two extraction methodologies (by maceration and microwave assisted extraction) for the extraction of antioxidant compounds, including resveratrol, was studied. We also carried out a comparison between extracts from different organs of Brazilian cultivars (IAC 886, IAC Caiapó, Tatu ST IAC, IAC 8112 and IAC 99-1) for antioxidant activity by DPPH, the content of phenolic compounds by Folin-Ciocalteu and the resveratrol content by HPLC. Finally, we established tissue culture protocols for seed explants, aiming at the production of in vitro plant material for future measurement of compounds of interest in the view of possible modulation of in vitro conditions. The best conditions for the extraction of antioxidant from A. hypogaea compounds by maceration were 80% of ethanol in water as a solvent, trituration by mortar and pestle, 50 mL solvent/g dry plant, 120 minutes of incubation and two stages of extraction. The best conditions for the extraction of resveratrol assisted by micro-wave were the use of 37 mL of solvent for each gram of dry plant, with 1200 rpm of agitation for 15 minutes, with 37oC. In general, root extracts and assisted by microwave showed higher antioxidant activity (until 92,36 2,71%), phenolic (untill 54,15 1,39 mg AGE/g extract) and resveratrol content (untill 1,614 0,356 mg/g extract). Among the studied cultivars, IAC Tatu and IAC 99-1 showed the best results. In tissue culture, shoots and friable calli were obtained from cotiledons, embryonic axis and embryonic leaflet cultured in media supplemented with BAP and picloram, respectively.
98

Análise química e avaliação das atividades biológicas e comportamentais de extratos de frutas ricas em compostos fenólicos (mirtilo e amora-preta) / Chemical analysis and evaluation of the biological and behavioral activities of extracts of fruits rich in phenolic compounds (Blueberry and blackberry)

Ramirez, Maria Rosana January 2008 (has links)
O presente estudo teve como objetivos: determinar o teor dos polifenóis: flavonóides e antocianos totais presentes nos extratos de mirtilo (Vaccinium ashei) e amora preta (Rubus sp) por espectrofotometria; desenvolver e validar uma metodologia analítica para a caracterização dos extratos por cromatografia líquida de alta eficiência (CLAE), identificar, isolar e quantificar os principais compostos; avaliar a atividade anticolinesterásica, antioxidante frente à difenilpicrilhidrazol (DPPH) e anti-quimiotática in vitro; realizar a dosagem de aminas biogênicas no cérebro, investigar as possíveis atividades antinociceptiva, antiinflamatória, antiepiléptica, cognitiva e neuroprotetora do extrato de Vaccinium ashei, e o efeito neuroprotetor de um composto isolado a partir de Rubus: a cianidina, em vários modelos experimentais in vivo, em ratos e camundongos. Os perfis cromatográficos apresentaram compostos comuns às duas amostras; onde foram identificados 4 flavonóides, sendo hiperosídeo, quercitrina e isoquercitrina comuns a ambos extratos, e a rutina confirmada apenas em Rubus. Cinco antocianidinas foram identificadas em Vaccinium: delfinidina, cianidina, petunidina, peonidina e malvidina, e a cianidina em Rubus. Os resultados demonstraram, diferenças nas quantidades totais de polifenóis, flavonóides e antocianos. Todos os extratos, apresentaram atividade seqüestradora do radical DPPH in vitro. A atividade antiquimiotática in vitro foi comprovada para a fração flavonoídica. Os ensaios biológicos realizados in vivo demonstraram que o extrato preparado a partir de uma mistura de diferentes cultivares de Vaccinium ashei apresentou efeitos antinociceptivos nos testes da formalina sub-plantar, contorções abdominais, placa quente e tail flick. Produziu também efeito neuroprotetor, avaliado pelo ensaio cometa e pelo método de TOSC. Também causou aumento da atividade locomotora, assim como exerceu um efeito ansiolítico em roedores adultos. Facilitou a memória de curta duração e a Memória de longa duração e produziu um aumento de 5-HT no estriado e hipocampo de ratos adultos. Foi observado também que a cianidina isolada exerceu atividade neuroprotetora conforme avaliado pelo método de TOSC em ratos adultos. Não foram observadas diferenças significativas no modelo de epilepsia, entre o grupo tratado e o grupo controle, assim como não foram detectadas alterações no sistema dopaminérgico. Em síntese, os dados analisados em conjunto, permitem sugerir que o extrato de Vaccinium ashei e compostos isolados a partir de Rubus sp., como a cianidina, apresentam importante efeito neuroprotetivo, antinociceptivo e cognitivo, e nesta ação está envolvida a participação direta ou indireta dos receptores serotonérgico, acetilcolinérgicos, opióides e de citocinas pró-inflamatórias. Neste sentido, foram obtidos avanços significativos acerca dos mecanismos de ação de ambos gêneros o que torna o seu extrato e seus princípios ativos interessantes para o aproveitamento e desenvolvimento de novos alimentos funcionais e/ou nutracêuticos. / The objectives of this study were: comparing total phenolics, total anthocyanins and antioxidant capacity in appropriate berry samples from selected cultivars of the Vaccinium ashei and Rubus. A reliable HPLC procedure for determining the profile, quantifying and isolating of major compounds present in the extracts have been developed. The potential effects of the extracts were observed by chemotaxis assay, by acetilcholinesterasic inhibition, and their antioxidant properties evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) in vitro. Otherwise, we examined the antinociceptive, antiinflammatory, cognitive, anti-epileptic and neuroprotective effects of the extract of Vaccinium ashei in several experimental models in vivo, as well as biogenic amine concentration, in specific brain regions in rats and mice. In addition, it was tested the efficacy of oral administration of cyanidin-3-glucoside extracted from Rubus sp. in lipid peroxidation in brain rats (TOSC). An HPLC method for the analysis of anthocyanidins and flavonoids in berries extracts have been developed. The data obtained show that various compounds are common in the fruits analyzed, and four flavonoids were identified: hyperoside, quercetrin and isoquercitrin occurring in both fruits, and rutin occurring only in Rubus. Five anthocyanidins were identified in Vaccinium: delphinidin, cyanidin, peonidin, petunidin, and malvidin, and in Rubus cyanidin 3-glucoside was the major anthocyanin. We found that the flavonoids fractions significantly have inhibited migration celullar and acetilcholynestarase, and both total extract and fractions exhibited strong antioxidant activity. The extract (a mixture from the different cultivars) significantly enhanced short and long-term memory in the inhibitory avoidance task, induced an increase in the number of crossings during open field habituation, and had an anxiolytic effect in the elevated plus-maze task. These processes are accompanied by alterations in serotonin (5-HT) in the striatum, and the hippocampus. Cyanidin 3-glucoside isolated significantly reduced lipid peroxidation in hippocampal tissue in rats. In conclusion, the data from the current study show that the Vaccinum extract produce an important neuroprotective, cognitive and antinociceptive effect, which could be related with a direct or indirect interaction with the serotonergic, cholinergic, opioids receptors and pro-inflammatory cytokines. On the other hand, the extract don’t have protected the pentilenotetrazole-induced convulsions in mice, or influenced the memory retention in old rats when accessed in the step-down inhibitory avoidance, and showed no anxiolytic action in an elevated plus maze. The Vaccinium ashei extract did not alter locomotor activity, and the dopamine concentration in adult or old rats.
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Evaluation of the antioxidant and anti-diabesity potential of cyclopia maculata using in vitro non-cell based screening models

Matrose, Albertina Neliswa January 2014 (has links)
Masters of Science / The aim of this study was therefore to evaluate the antioxidant and anti-diabesity potential of a hot water extract of C. maculata in non-cell based assays and correlate the activities with phenolic composition. Total antioxidant capacity (TAC) was assessed in terms of free radical scavenging and iron reducing ability. The DPPH, ABTS, ORAC and FRAP assays were employed. Anti-diabesity potential was assessed in terms of the inhibition of the digestive enzymes, α-glucosidase and pancreatic lipase
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PSE extrakce rostlinného materiálu pro potravinářské účely / Pressurized solvent extraction of plant material for food industry use

Holasová, Petra January 2009 (has links)
Flavonoids were identified and quantified in samples of dry leaves of plant Stevia rebaudiana Bertoni. Content of flavonols (kaempherol, quercetin, myricetin, rutin) and flavons (apigenin, luteolin) were compared in three samples (standard leaves of Stevia rebaudiana Bertoni, Stevia rebaudiana Bertoni origin from Ukraine and from Czech republic), that were extracted by three extraction methods (PSE, ultrasonic extraction, Soxhlet extraction) with two polar solvents, methanol and ethanol, in combination with non-polar hexane. Extracts were analyzed by HPLC with detection UV-VIS. Antioxidant activity and total content of flavonoids in extracts were measured by spectrometry. Stable free radical DPPH. was used for determination of scavenging effect in extracts. PSE was the most effective extraction method with this conditions – 120 °C, dynamic mode and with methanol like solvent.

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