As plantas alimentícias são definidas como plantas que têm uma ou mais partes ou produtos que podem ser empregados na alimentação das pessoas. As espécies comestíveis que não são frequentemente utilizadas, são denominadas plantas alimentícias não convencionais (PANC). A espécie Talinum paniculatum (Jacq.) Gaertn. (Major-Gomes) é considerada uma excelente hortaliça, além de todas as partes da planta serem utilizadas na medicina caseira. Foram realizados testes para avaliar a intensidade de Atividade de Inibição Bacteriana/Bacteriostasia (IINIB) e Intensidade de Atividade de Inativação Bacteriana/Bactericidia (IINAB) do extrato alcoólico de folhas e ramos de Talinum paniculatum utilizados juntos, acessada na cidade de Porto Alegre/RS, sobre os microrganismos padrões ATCC: Enterococcus faecalis (ATCC 19433), Escherichia coli (ATCC 11229), Salmonella Enteritidis (ATCC 13076) e Staphylococcus aureus (ATCC 25923). Também foram realizados testes com as folhas e os ramos de Talinum paniculatum utilizados juntos, para determinar e quantificar: a composição centesimal (umidade, cinzas, carboidratos, proteínas, lipídeos e fibra bruta), em base seca e úmida; minerais em base seca, e polifenóis totais e vitamina C da planta logo após a colheita. Quanto à IINAB, a bactéria mais resistente, foi a Gram-positiva Enterococcus faecalis e a mais sensível foi a Gram-negativa Salmonella Enteritidis. Com relação à IINIB, a bactéria mais resistente, foi a Gram-positiva Staphylococcus aureus e a mais sensível foi a Gram-positiva Enterococcus faecalis. Tanto para IINAB quanto para IINIBI houve diferença significativa entre as bactérias testadas e as concentrações do extrato. Os resultados da composição química de Talinum paniculatum, indicam que esta espécie pode representar um complemento para a alimentação dos seres humanos e fornecer teores consideráveis de macronutrientes e micronutrientes, além de contribuir com o consumo de substâncias bioativas, como a vitamina C, que em 100g de amostra representou mais da metade da ingestão diária recomendada. / The food plants are defined as plants that have one or more parts or products that can be used to feed people. Edible species that are not often used are called unconventional food plants. The species Talinum paniculatum (Jacq.) Gaertn. (Major-Gomes) is an excellent vegetable, and all parts of the plant are used in homemade medicine. Tests were performed to evaluate the intensity of bacterial inhibition activity (IINIB) and the intensity of bacterial inactivation activity (IINAB) of alcoholic extract of stalks and leaves of Talinum paniculatum used together, from Porto Alegre/ RS, confronted with standard inoculum: Enterococcus faecalis (ATCC 19433), Escherichia coli (ATCC 11229), Salmonella Enteritidis (ATCC 13076 ) e Staphylococcus aureus (ATCC 25923). Tests were also conducted with stalks and leaves of Talinum paniculatum used together to determine and quantify: proximal composition (moisture content, ashes content, proteins, lipids and crude fiber, in dry and wet basis; minerals in dry basis and total polyphenols and vitamin C of stalks and leaves of plant soon after harvest. As for IINAB, the Gram-positive bacteria Enterococcus faecalis was the most resistant and the Gram-negative bacteria Salmonella Enteritidis was the most sensitive. With relation to IINIB, the Gram-positive bacteria Staphylococcus aureus was the most resistant and the Gram-positive bacteria Enterococcus faecalis was the most sensitive. For IINAB and IINIB there was a significant difference between the tested bacteria and concentrations of the extract. The results of the chemical composition of Talinum paniculatum indicate that the species can be a food supplement for human beings and can provide considerable levels of macronutrients and micronutrients, furthermore contribute to the consumption of bioactive substances, such as vitamin C that in 100g sample represented more than half of the recommended daily intake.

Submitted by Emanuel Varela Cardoso (emanuel.varela@ufcg.edu.br) on 2018-10-16T16:03:48Z No. of bitstreams: 1 FAUSTO VAZ DE OLIVEIRA – DISSERTAÇÃO (PPGFísica) 2014.pdf: 2950759 bytes, checksum: f75675457b33950244dae94b86657cac (MD5) / Made available in DSpace on 2018-10-16T16:03:48Z (GMT). No. of bitstreams: 1 FAUSTO VAZ DE OLIVEIRA – DISSERTAÇÃO (PPGFísica) 2014.pdf: 2950759 bytes, checksum: f75675457b33950244dae94b86657cac (MD5) Previous issue date: 2014-03-13 / CNPq / Neste trabalho usamos a técnica de Espectroscopia Fotoacústica na identificação de Biomoléculas Funcionais, presentes em várias frutas e vegetais. Essas biomoléculas, em geral compostos polifenólicos, formam grupos de substâncias amplamente distribuídos em plantas, frutas e legumes, componentes comuns da alimentação humana, especialmente flavonóides e taninos que possuem diversas propriedades terapêuticas e farmacológicas. Dentre as espécies de frutas e cereais investigadas, cientificamente estabelecidas como depositárias de moléculas bioativas, algumas se destacam por suas excelentes propriedades funcionais, tendo, por este motivo, recebido o nome pomposo de “superfrutas”. São elas caracterizadas por apresentarem altas concentrações de polifenóis tais como as antocianinas, os flavonóis (quercetinas, kaempferol, catequinas, resveratrol e taninos), os ácidos fenólicos como o gálico, o ascórbico, o elágico, o clorogênico, o benzóico, o felúrico, etc e os carotenóides, onde se destacam o β–caroteno, licopeno, violaxantina, zeaxantina, luteína, neoaxantina, dentre outras. As superfrutas são assim classificadas por exibirem extraordinário valor funcional. Os resultados experimentais obtidos por espectroscopia fotoacústica para os comprimentos de onda λmax que representa os picos de absorção em cada amostra de frutas e vegetais investigados evidenciam a existência de Biomoléculas Funcionais, que fazem bem a saúde humana. Nossos resultados, obtidos pela técnica de Espectroscopia Fotoacústica, confirmam esta como uma ferramenta experimental de grande potencial e eficiência na identificação de biomoléculas em sistemas biológicos “in natura”, sem necessidade de utilização de processos exaustivos de extração molecular. / In this work we have used the technique of Photoacoustic Spectroscopy to identify Functional Biomolecules, present in various fruits and vegetables. These polyphenolic compounds constitute groups of substances widely distributed in plants, fruits and vegetables, common components of the human diet, especially anthocyanins, flavonols, tannins and carotenoids that have been found to exhibit several therapeutic and pharmacological properties. Among the fruits and vegetables species investigated and scientifically established as host for bioactive or functional biomolecules, some of them are detached by their excellent functional properties, then, have been nominates as “superfruits”. They are characterized by exhibit high concentrations of polyphenols compounds such as anthocyanins, flavonols (quercitins, kaempferol, catechins, tannins), the phenolic acids such as the gallic, ascorbic, ellagic, chlorogenic, benzoic, ferulic, etc, and the carotenoids β–carotene, lycopene, violaxanthin, zeaxanthin, lutein, neoaxanthin among others. The “superfruits” are classified in this way for exhibit functional extraordinary value. The experimental results obtained by photoacoustic spectroscopy λmax for the wave lengths representing the absorption peaks of each sample of fruits and vegetables investigated showed the existence of Functional Biomolecules, which are human health as well. Our results obtained by the technique Photoacoustic Spectroscopy confirm this as an experimental tool with great potential and efficiency in the detection of biomolecules in biological systems “in nature”, without the need of using exhaustive molecular extraction processes.

In this thesis, "The Evaluation of the Quality of Hops from Traditional and Non-traditional Growing Areas", the quality of three varieties of hop seed cones (Saaz, Sladek and Kazbek) from a non-traditional hop-growing region was analyzed and the data used for comparison. The primary aim of the study was to determine if there is a possibility of growing quality hops in a region that is not considered a hop-growing region. The hops that were tested were harvested in 2015 from a private hopfield located in Obora near Tábor. This hopfield is owned and managed by Ing. Martin Novák. Mechanical and chemical analysis was carried out on samples from Obora. The main goal of the analysis was to determine the alpha and beta acid content of the hop seed cones harvested there. Samples were analyzed with EBC 7.7 (HPLC). Alpha acid content of the tested samples in Saaz hops was 4.06 % w/w, in Sladek 7.14 % w/w and in Kazbek 4.67 % w/w. The content of beta acids in Saaz hops was 3.16 % w/w, in Sladek 3.93 % w/w and in Kazbek 4.51 % w/w. The collected data was then compared to published data for hops grown in traditional hop-growing regions. Alpha acid content was found to be higher in the hops grown in Obora, while beta acid content was lower.

No período compreendido entre os meses de Maio de 2010 e Dezembro de 2011 realizou-se, nos laboratórios de Higiene e Qualidade de Alimentos, de Microbiologia e Bromatologia e de Bioquímica e Microbiologia Aplicada do Instituto de Ciências e Tecnologia de Alimento (ICTA) da Universidade Federal do Rio Grande do Sul (UFRGS), experimentos com vista à quantificação de compostos fenólicos e à avaliação da atividade antibacteriana de dois acessos de batata-doce (Ipomoea batatas L. (Lam)) com objetivo de (i) avaliar a atividade antibacteriana nestes acessos perante padrões bacterianos de interesse em alimentos, (ii) determinar a quantidade de compostos fenólicos e (iii) estabelecer a relação entre a composição e quantidade de compostos fenólicos e a atividade antibacteriana nestes diferentes acessos. Com o material colhido em Porto Alegre, Santo Antônio de Patrulha, Palmares do Sul e Cerro grande do Sul, utilizou-se o método de diluição em sistema de tubos múltiplos para avaliar a intensidade de atividade antibacteriana dos diferentes extratos expressa como intensidade de atividade de inibição bacteriana (IINIB) e intensidade de atividade de inativação bacteriana (IINAB); o teor de polifenóis totais foi determinado pelo método de Folin & Ciocalteu, enquanto que a determinação do conteúdo de antocianinas foi efetuada usando o método de pH diferencial. O coeficiente de correlação de Pearson foi usado para estabelecer a relação entre os teores de polifenóis e a atividades antibacteriana. Os extratos alcoólicos inibiram e/ ou inativaram inóculos de Salmonella Enteritidis (ATCC 11076), Enterococcus faecalis (ATCC 19433), Escherichia coli (ATCC 11229) e Staphylococcus aureus (ATCC 25923), não obstante esta úlima ser significativamente mais resistente. A intensidade de atividade de inibição e/ ou inativação está positivamente relacionada à concentração de compostos fenólicos, ou seja, os compostos fenólicos e/ ou antocianinas seriam responsáveis pelo menos por parte da atividade antibacteriana dos extratos testados nas condições deste experimento. Extratos tidos por decocção e infusão, além de apresentarem concentrações muito baixas de antocianinas, não apresentaram atividade antibacteriana e mostraram menores teores de polifenóis do que os seus correspondentes extratos alcoólicos, sugerindo que o calor da infusão e/ ou decocção provavelmente teria degradado as substâncias essenciais que tomam parte no processo de atividade antimicrobiana. / In the period between the months of May 2010 and December 2011 was held in the laboratories of Higiene and Food Quality, Microbiology and Bromatology and Biochemistry and Applied Microbiology of the Institute for Food Science and Technology (ICTA) of the Federal University of Rio Grande do Sul (UFRGS), experiments for the evaluation of antibacterial activity and the quantification of phenolic compounds in two accessions of sweet potato (Ipomoea batatas L. (Lam) in order to (i) evaluate the antibacterial activity in these accessios against interest food bacteria, (ii) determine the quantity of phenolic (iii) establish the relationship between the composition and quantity of phenolic compounds and the antibacterial activity in these different accessions. With material collected in Porto Alegre, Santo Antônio de Patrulha, Palmares do Sul and Cerro Grande do Sul, the method of dilution in system of multiple-tube tests was used to evaluate the intensity of antibacterial activity of different extracts express as intensity of bacterial inhibition activity (IINIB) and intensity of bacterial inativation activity (IINAB); the total phenolic content was determined by the method of Folin & Ciocalteu, while the content of antocianinas was performed using the differential pH method. The Pearson correlation coefficient was used to establish the relationship between the levels of polyphenols and antibacterial activity. The alcoholic extracts inhibited and/or inactivated inocula of Salmonella Enteritidis (ATCC 11076), Enterococcus faecalis (ATCC 19433), Escherichia coli (ATCC 11229) and Staphylococcus aureus (ATCC 25923), although this this last was significantly tougher. The intensity of inhibition and/or inactivation activity is positively related to the concentration of phenolic compounds, ie, phenolic compounds and/or anthocyanins are responsible for at least, part of the antibacterial activity of the extracts tested in this experiment. Extracts got from decoction and infusion besides having very low concentrations of anthocyanins, showed no antibacterial activity and had lower levels of polyphenols than their corresponding alcoholic extracts, suggesting that the higher temperature used for infusion and/or decoction, would probably degraded essential substances taking part in the process of antimicrobial activity.

As plantas alimentícias são definidas como plantas que têm uma ou mais partes ou produtos que podem ser empregados na alimentação das pessoas. As espécies comestíveis que não são frequentemente utilizadas, são denominadas plantas alimentícias não convencionais (PANC). A espécie Talinum paniculatum (Jacq.) Gaertn. (Major-Gomes) é considerada uma excelente hortaliça, além de todas as partes da planta serem utilizadas na medicina caseira. Foram realizados testes para avaliar a intensidade de Atividade de Inibição Bacteriana/Bacteriostasia (IINIB) e Intensidade de Atividade de Inativação Bacteriana/Bactericidia (IINAB) do extrato alcoólico de folhas e ramos de Talinum paniculatum utilizados juntos, acessada na cidade de Porto Alegre/RS, sobre os microrganismos padrões ATCC: Enterococcus faecalis (ATCC 19433), Escherichia coli (ATCC 11229), Salmonella Enteritidis (ATCC 13076) e Staphylococcus aureus (ATCC 25923). Também foram realizados testes com as folhas e os ramos de Talinum paniculatum utilizados juntos, para determinar e quantificar: a composição centesimal (umidade, cinzas, carboidratos, proteínas, lipídeos e fibra bruta), em base seca e úmida; minerais em base seca, e polifenóis totais e vitamina C da planta logo após a colheita. Quanto à IINAB, a bactéria mais resistente, foi a Gram-positiva Enterococcus faecalis e a mais sensível foi a Gram-negativa Salmonella Enteritidis. Com relação à IINIB, a bactéria mais resistente, foi a Gram-positiva Staphylococcus aureus e a mais sensível foi a Gram-positiva Enterococcus faecalis. Tanto para IINAB quanto para IINIBI houve diferença significativa entre as bactérias testadas e as concentrações do extrato. Os resultados da composição química de Talinum paniculatum, indicam que esta espécie pode representar um complemento para a alimentação dos seres humanos e fornecer teores consideráveis de macronutrientes e micronutrientes, além de contribuir com o consumo de substâncias bioativas, como a vitamina C, que em 100g de amostra representou mais da metade da ingestão diária recomendada. / The food plants are defined as plants that have one or more parts or products that can be used to feed people. Edible species that are not often used are called unconventional food plants. The species Talinum paniculatum (Jacq.) Gaertn. (Major-Gomes) is an excellent vegetable, and all parts of the plant are used in homemade medicine. Tests were performed to evaluate the intensity of bacterial inhibition activity (IINIB) and the intensity of bacterial inactivation activity (IINAB) of alcoholic extract of stalks and leaves of Talinum paniculatum used together, from Porto Alegre/ RS, confronted with standard inoculum: Enterococcus faecalis (ATCC 19433), Escherichia coli (ATCC 11229), Salmonella Enteritidis (ATCC 13076 ) e Staphylococcus aureus (ATCC 25923). Tests were also conducted with stalks and leaves of Talinum paniculatum used together to determine and quantify: proximal composition (moisture content, ashes content, proteins, lipids and crude fiber, in dry and wet basis; minerals in dry basis and total polyphenols and vitamin C of stalks and leaves of plant soon after harvest. As for IINAB, the Gram-positive bacteria Enterococcus faecalis was the most resistant and the Gram-negative bacteria Salmonella Enteritidis was the most sensitive. With relation to IINIB, the Gram-positive bacteria Staphylococcus aureus was the most resistant and the Gram-positive bacteria Enterococcus faecalis was the most sensitive. For IINAB and IINIB there was a significant difference between the tested bacteria and concentrations of the extract. The results of the chemical composition of Talinum paniculatum indicate that the species can be a food supplement for human beings and can provide considerable levels of macronutrients and micronutrients, furthermore contribute to the consumption of bioactive substances, such as vitamin C that in 100g sample represented more than half of the recommended daily intake.

The thesis deals with antioxidants in food and their function in the process of defence against the effects of free radicals. At first, antioxidants are defined and their clasification is described in the theoretical part. Then this part deals with antioxidants in food, their effects on people´s health and antioxidants recommended daily doses. Possitive and negative effects of free radicals on people´s health and their relation to antioxidants are mentioned next. In the practical part, I concentrate on the survey focused on the investigation of the population awareness of antioxidants and their effects on health. One hundred and sixty respondents took part in the survey. They were devided into two groups; working people and pensioners. The questionnaire contained twelve questions which investigated the population awareness of the topic. The data collection took place in January 2013 and it was evaluated in February 2013. The collected data were evaluated according to basic statistical methods. The ascertained answers were put into unified tables and then they were compared. Especially, the general awareness was investigated and then the effect of education on the knoledge of the topic was considered.

Antioxidants and free radicals are widely discussed in the clinical and nutritional literature. Various reactive oxygen species (ROS) may be produced from normal biochemical, essential metabolic processes or from external sources as exposure to a variety of agents presented in the environment. Lipids, proteins, carbohydrates and DNA are all capable of reacting with ROS and can be implicated in etiology of various human disorders. The antioxidant system protects the organism from the effects of free radicals by scavenging them and thus preventing structural damage of cells. Measuring the individual components of the antioxidant system has provided important information about the defences against free radical effect. During the last decade, many analytical methods have been developed to determine the antioxidant activity of natural compounds and their mixtures in vitro. Some procedures involve the methods based on the generation of various radical species and their elimination by treatment with potential antioxidant compounds. The tests used for the evalution of total antioxidant activity are: Trolox equivalent antioxidant capacity-TEAC, diphenylpicrylhydrazil - DPPH, oxygen radical absorbance capacity-ORAC and the methods testing the ability to prevent lipid peroxidation. The other group includes the procedures that are based on measurement of redox properties of compouds (ferric reducing antioxidant potential assay-FRAP, cyclic voltammetry, HPLC).

A juçara, Euterpe oleracea Mart., fruta indígena da Amazônia Legal, é rica em fitoquímicos com atividades anti-oxidante, antiinflamatória e anti-câncer. Este estudo tem por objetivo analisar os efeitos do extrato hidroalcoólico da casca, caroço e fruto total da juçara em diferentes linhagens de células malignas humana. Os frutos foram coletados no Parque da Juçara, localizado no Maracanã, município de São Luís, seguida da confecção da excicata que se mantém registrada no Herbário Rosa Mochel do Núcleo de Estudos Biológicos da Universidade Estadual do Maranhão. Os extratos hidroalcoólicos da casca, caroço e fruto total foram extraidos no Laboratório de Farmacologia e Psicobiologia da UERJ. As linhagens celulares utilizadas nos ensaios foram MCF-7 (adenocarcinoma de mama), CACO-2 e HT-20 (adenocarcinoma colo retal) e adenocarcinoma na mama (MDA-MB-468). As linhagens foram tratadas com 10, 20 e 40g/mL dos extratos por 24 e 48 horas e feitas às análises. Células MCF-7 controle apresentaram núcleo proeminente com nucléolos evidentes. Após tratamento com o extrato hidroalcoólico da casca da juçara, as células mostraram morfologia arredondada com retração do citoplasma. O ensaio de viabilidade com MTT ((3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide)) demonstrou uma redução na viabilidade das células. Após 48 horas, o tratamento das células com 20g/mL do extrato da casca reduziu a viabilidade sendo que o efeito citotóxico do tratamento com 40g/mL do extrato da casca foi potencializado. Células tratadas com 10g/mL do extrato do caroço de juçara apresentavam-se arredondadas com consequente redução no volume celular. A concentração 20g/mL de extrato hidroalcoólico do caroço, causou severa redução no volume das células e ocasionou o surgimento de vacúolos intracelulares. O mesmo foi observado após tratamento com 40g/mL. O tratamento com 40g/mL do extrato hidroalcoólico do fruto total, modificou drasticamente a morfologia das células MCF-7 causando vacuolização e aparente lise com perda do conteúdo citoplasmático e o ensaio da viabilidade com MTT demonstrou redução na viabilidade das células MCF-7 tratadas com 20 e 40g/mL após 24 horas de tratamento. Análises por MET (Microscopia Eletrônica de Transmissão) demonstraram o surgimento de vesículas autofágicas, cuja comprovação deu-se com a identificação da expressão da proteína LC3BII na membrana do autofagossoma pela técnica de Western Blotting. Mediante o demonstrado pelos experimentos, com as linhagens MCF-7 e MDA-MB-468, confirma-se que as frações isoladas do extrato do caroço da juçara, promove modificações celulares indicativas de autofagia a partir de 10g/mL, em 24 horas. O núcleo permaneceu íntegro, não apresentando características de núcleo apoptótico. Os dados são conclusivos para ocorrência de morte celular por autofagia em linhagem celulares de carcinoma de mama MCF-7 quando tratadas com extrato hidroalcoólico da casca, caroço e fruto total da juçara do Maranhão, agente quimiopreventivo no câncer de mama estrogênio-dependente. / Juçara, Euterpe oleracea Mart., an indigenous fruit from Amazon, is rich in phytochemicals with antioxidant, anti-inflammatory and anti-cancer activity. This study aims to analyze the effects of the hydroalcoholic extract of the bark, seed and total fruit of juçara in different human malignant cell lines. Fruits were collected at the Maracana Ecological Park, in São Luís, followed by excicata manufacturing that remains registered in the Herbarium Rosa Mochel from the Nucleus of Biological Studies at the State University of Maranhão. The hydroalcoholic extracts of bark, seed and fruit were all obtained in the Laboratory of Pharmacology and Psychobiology UERJ. The cell lines used in the tests were MCF-7 and MDA-MB-468 (breast adenocarcinoma) and CACO-2 and HT-20 (colorectal adenocarcinoma). Strains were treated with 10, 20 and 40μg/mL of extracts for 24 and 48 hours. Control MCF-7 cells showed prominent nucleus with evident nucleoli. After treatment with the hydroalcoholic extract from the bark of juçara, the cells showed rounded morphology with retraction of the cytoplasm. The MTT viability assay showed a reduction in cell viability. After 48 hours, treatment of cells with 20μg/mL of bark extract reduced cell viability and the cytotoxic effect of treatment with 40μg/mL extract of the bark was potentiated. Cells treated with 10μg/mL of the bark extract were rounded with consequent reduction in cell volume. The concentration of 20μg/mL of bark extract caused severe reduction in volume of the cells and caused the appearance of intracellular vacuoles. The same was observed after treatment with 40μg/mL. Treatment with 40μg/mL of the hydroalcoholic extract of total fruit dramatically changed the morphology of the MCF-7 cells causing vacuolization and lysis with apparent loss of cytoplasmic contents. MTT assay showed a reduction in viability of MCF-7 cells treated with 20 and 40μg/mL after 24 hours of treatment. Analysis by electron microscopy showed the appearance of autophagic vacuoles. Autophagosome protein LC3BII was identified by Western Blotting technique. It is confirmed that the isolated fractions of the bark extract from juçara promotes cellular changes indicative of autophagy from 10μg/mL in 24 hours. The nuclei remained intact, showing no apoptotic features. The data are conclusive for the occurrence of autophagy in carcinoma cell line MCF-7 breast treated with hydroalcoholic bark, seed and fruit from juçara.

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.

La phytothérapie désigne la médecine fondée sur les extraits de plantes et les principes actifs naturels. Devant l’augmentation considérable du nombre de diabétiques, de nombreux chercheurs ont cherché à évaluer l’action pharmacologique de certaines plantes traditionnelle. Le jojoba (Simmondsia chinensis) est un arbuste de la famille des Simmondsiacées qui possède de nombreuses propriétés liées à une composition très riche et très diversifiée. Les objectifs poursuivis au cours de cette thèse étaient de valider l’utilisation du jojoba dans la prévention de diabète de type 2 et de ses complications en évaluant l’effet antioxydant in vitro d’un extrait aqueux de jojoba et en le comparant à un extrait purifié, la simmondsine, sur une lignée pancréatique, et démontrant l’efficacité de différents extraits de la graine de jojoba sur une lignée cellulaire hépatique suite à une hyperglycémie chronique et un hyperinsulinisme et enfin en validant in vivo l’efficacité du jojoba sur un modèle d’intolérance au glucose induit chez le rat à l’aide d’une alimentation riche en fructose et en graisse (HFHF). Les résultats in vitro ont montré que les différents extraits de la graine de jojoba testés ne possèdent aucune toxicité sur les lignées cellulaires mais permettent d’assurer une protection face à un stress oxydant induit par une hyperglycémie et un hyperinsulinisme. Cette protection semble être liée à l’inhibition en amont de l’expression de l’enzyme pro-oxydante p22phox. In vivo, l’étude sur le modèle de rat HFHF a permis de confirmer l’effet anorexigène du jojoba associé à un effet curatif sur les complications, notamment hépatiques et rénales, qui pourrait être lié à son pouvoir anti-oxydant. Cette étude a ainsi permis de démontrer l’efficacité des graines de jojoba dans le traitement du diabète et de ses complications. / Herbal medicine refers to medicine based on plant extracts and natural active ingredients. As the number of diabetic patient increase dramatically, many researchers have sought to evaluate the pharmacological action of several traditional plants. The jojoba (Simmondsia chinensis) is a shrub of the family Simmondsiaceae which has many properties linked to a very rich and diversified composition. The objectives pursued during this thesis were to validate the use of jojoba in the prevention of type 2 diabetes and its complications by evaluating in vitro the antioxidant effect of an aqueous extract of jojoba and compare this extract to a pure molecule, the simmondsin, on a pancreatic beta cell line, by demonstrating the efficacy of the various extracts of the jojoba seed on a hepatic cell line following chronic hyperglycemia and hyperinsulinemia and finally by validating in vivo the efficacy of jojoba on rat a model of glucose intolerance induced by high-fat high-fructose diet (HFHF). The results in vitro showed that the various extracts of the jojoba seed tested were not cytotoxic on the cell lines but provided protection against oxidative stress induced by hyperglycemia and hyperinsulinemia. This protection appears to be related to the inhibition of the expression of the p22phox pro-oxidant enzyme. In vivo, the study on the HFHF rat model confirmed the anorectic effect of jojoba combined with a curative effect on complications, in particular liver and kidney damage, which could be linked to its antioxidant properties. This study demonstrated the efficacy of jojoba seeds in the treatment of diabetes and its complications.