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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Chemotypic variation and biopharmaceutics of Sceletium tortuosum alkaloids.

Shikanga, Emmanuel Amukohe. January 2012 (has links)
D. Tech. Chemistry. / Aims to isolate and characterise mesembrine-type alkaloids from S. tortuosum for use as reference standards ; develop and validate analytical methods for the accurate determination of mesembrine-type alkaloids in S. tortuosum samples and commercial products for quality control purposes ; investigate inter-species variation of alkaloids in endemic Sceletium species ; establish the variation of mesembrine-type alkaloids within and between different populations of S. tortuosum specimens and hence identify various chemotypes ; determine the variations of the target alkaloids in S. tortuosum commercial products purchased from various suppliers ; determine the mesembrine-type alkaloid content of the combustion products from S. tortuosum; and to evaluate the in vitro permeation of the alkaloids across oral and intestinal mucosa.
42

Studies in Marine Natural Products.

Reddy, Priyanka, saipriyanka@gmail.com January 2009 (has links)
The focus of this thesis was to study the chemotaxonomic relationship of selected southern Australian marine brown algae of the genera Cystophora and Sargassum. Consequently, this resulted in the isolation and structure elucidation of six new terpenoids from two southern Australian marine brown algae Cystophora moniliformis and Sargassum fallax together with 10 previously reported natural products. As a result of the re-isolation of these known secondary metabolites, updated and complete structural characterisation data could be provided for the first time for 7 of these compounds. Chemotaxonomic studies of Cystophora moniliformis resulted in the isolation of two new cyclic epimeric terpene diols moniliforminol A (3.25) and moniliforminol B (3.26), a new linear farnesyl acetone derivative (3.27) and the previously described terpenoids (3.19)-(3.24). This study also resulted in the first complete 2D NMR characterisation for compounds (3.21) to (3.24) as well as the first report of (3.24) occurring as a natural product. All structures were elucidated by detailed spectroscopic analysis with the relative configurations of (3.25) and (3.26) being established by selective 1D nOe NMR experiments. The proposed biosynthetic pathway for the above compounds has also been described. Chemical investigation of the Southern Australian marine brown alga Sargassum fallax resulted in the isolation of three new meroditerpenoids fallahydroquinone (4.8), fallaquinone (4.9) and fallachromenoic acid (4.10), together with the previously reported compounds sargaquinone (4.1) (isolated and identified in a mixture with sargaquinoic acid), sargahydroquinoic acid (4.2), sargaquinoic acid (4.3) and sargachromenol (4.11). As a result of this study the complete 2D NMR characterisation for sargahydroquinoic acid (4.2) and sargaquinoic acid (4.3) could also be reported for the first time. All structures were elucidated by detailed spectroscopic analysis. Sargahydroquinoic acid (4.2) and sargaquinoic acid (4.3) displayed moderate antitumour activity.
43

Anatomia, análise do óleo essencial e germinação de sementes de três espécies de Viguiera Kunth (Asteraceae - Heliantheae) / Anatomy, analysis of the essential oil and seed germination of three species of Virguiera Kunth (Asteraceae - Heliantheae)

Bombo, Aline Bertolosi, 1985- 20 August 2018 (has links)
Orientador: Beatriz Appezzato da Glória, Vera Lúcia Garcia Rehder / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-20T10:55:10Z (GMT). No. of bitstreams: 1 Bombo_AlineBertolosi_M.pdf: 4141417 bytes, checksum: 23d44ff8ee2ca0a59a65cebea23db4a2 (MD5) Previous issue date: 2012 / Resumo: A família Asteraceae é uma das maiores famílias de angiospermas, com ampla distribuição e hábitos muito variados. O gênero Viguiera pertence à subtribo Heliantheae e conta com aproximadamente 180 espécies. No Brasil ocorrem 35 espécies e 27 dessas são endêmicas. Por se tratar de um gênero com muitos representantes, as relações filogenéticas não estão bem estabelecidas e estudos morfológicos e moleculares têm sido realizados com o objetivo de auxiliar a circunscrição do gênero. As espécies de Viguiera possuem potencial resinífero e as contempladas neste estudo são aromáticas em seu ambiente natural. Diversos estudos fitoquímicos têm destacado o potencial farmacológico de espécies do gênero, atribuído principalmente, à atividade das lactonas sesquiterpênicas e dos diterpenos. No entanto, estudos sobre a composição química dos óleos essenciais são escassos. A ocorrência das espécies do gênero Viguiera no Brasil se dá, principalmente, em regiões com inverno seco, devido à presença de um sistema subterrâneo espessado. O sistema subterrâneo das espécies incluídas neste estudo, Viguiera filifolia, V. linearifolia e V. trichophylla, consiste em um xilopódio, que apesar da capacidade gemífera, não possui capacidade de propagação vegetativa. As três espécies são muito semelhantes morfologicamente em estado vegetativo sendo diferenciadas principalmente por caracteres reprodutivos. Há registros na literatura de confusões na delimitação das mesmas. Além disso, V. filifolia e V. trichophylla constam na lista vermelha das espécies brasileiras como criticamente em perigo. Assim, os estudos anatômicos visaram contribuir com o levantamento de caracteres diagnósticos entre as três espécies. Os dados referentes à composição dos óleos essenciais também podem ser úteis do ponto de vista taxonômico, auxiliando na delimitação das espécies e ainda, no levantamento de possíveis compostos bioativos. Por fim, o estudo da germinação das sementes visou fornecer dados para futuros estudos de cultivo dessas espécies / Abstract: Asteraceae is one of the largest families of angiosperms with wide distribution and habits varied. Viguiera genus is included in the Heliantheae subtribe and has approximately 180 species. In Brazil, there are 35 species and 27 are endemic. Given that this genus has many representatives, phylogenetic relationships are not well established and morphological and molecular studies have been conducted to help limit the genus. Viguiera species have resin potential and the species used in this study are aromatic in their natural environment. Several phytochemical studies have shown the pharmacological potential to Viguiera species, attributed mainly to the activity of sesquiterpene lactones and diterpenes. However, studies on the chemical composition of essential oils are rare. In Brazil, the Viguiera species occurs mainly in regions of dry winter, due the presence of a thickened underground system. The underground system of the species used in this study, Viguiera filifolia, V. linearifolia and V. trichophylla is represented by a xylopodium, incapable of vegetative propagation despite forming buds. The three species are morphologically very similar in vegetative state and could be differentiated only by reproductive features. In the literature, there is confusion in individuating them. In addition, V. filifolia and V. trichophylla are classified in the Brazilian Species lias critically endangered. Thus, anatomical studies aimed at contributing to obtain diagnostic features among the three species. The essential oil composition data could help in chemosystematics and in the identification of possible chemotherapeutic compounds. Finally, the study of seed germination aimed to provide information for future studies for the cultivation of these species / Mestrado / Biologia Vegetal / Mestre em Biologia Vegetal
44

Advances in Solid Phase Microextraction for the Analysis of Volatile Compounds in Explosives, Tire Treatments, and Entomological Specimens

Kranz, William D. 05 1900 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Solid phase micro-extraction is a powerful and versatile technique, well-suited to the analysis of numerous samples of forensic interest. The exceptional sensitivity of the SPME platform, combined with its adaptability to traditional GC-MS systems and its ability to extract samples with minimal work-up, make it appropriate to applications in forensic laboratories. In a series of research projects, solid phase micro-extraction was employed for the analysis of explosives, commercial tire treatments, and entomological specimens. In the first project, the volatile organic compounds emanating from two brands of pseudo-explosive training aids for use in detector dog imprinting were determined by SPME-GC-MS, and the efficacy of these training materials was tested in live canine trials. In the second project, the headspace above various plasticizers was analyzed comparative to that of Composition C-4 in order to draw conclusions about the odor compound, 2- ethyl-1-hexnaol, with an eye toward the design of future training aids. In the third, automobile tires which had participated in professional race events were analyzed for the presence of illicit tire treatments, and in the fourth, a novel SPME-GC-MS method was developed for the analysis of blowfly (Diptera) liquid extracts. In the fifth and final project, the new method was put to the task of performing a chemotaxonomic analysis on pupa specimens, seeking to chemically characterize them according to their age, generation, and species.
45

Emprego de redes neurais e de descritores moleculares em quimiotaxonomia da família Asteraceae / Use of Neural Networks and Molecular Descriptors in Chemotaxonomy of the Asteraceae Family

Scotti, Marcus Tullius 18 July 2008 (has links)
Esse trabalho descreve o desenvolvimento de uma nova ferramenta quimioinformática designada de SISTEMATX que possibilitou a análise quimiotaxonômica da família Asteraceae, empregando novos parâmetros moleculares, bem como o estudo da relação quantitativa estrutura química atividade biológica de substâncias provenientes desse grupo vegetal. A família Asteraceae, uma das maiores entre as angiospermas, caracteriza-se quimicamente pela produção de sesquiterpenos lactonizados (SLs). Um total de 1111 (SLs), extraídos de 658 espécies, 161 gêneros, 63 subtribos e 15 tribos da família Asteraceae foram representados e cadastrados em duas dimensões no SISTEMATX e associados à respectiva origem botânica. A partir dessa codificação, o grau de oxidação e as estruturas em três dimensões de cada SL foram obtidos pelo sistema. Essas informações, associadas aos dados botânicos, foram exportadas para um arquivo texto, o qual permitiu a obtenção de vários tipos de descritores moleculares. Esses parâmetros moleculares foram correlacionados com o grau de oxidação médio por tribo e tiveram sua seleção realizada por regressão linear múltipla utilizando algoritmo genético. Equações com coeficientes estatísticos variando entre 0,725 ≤ r2 ≤ 0,981 e 0,647 ≤ Qcv2 ≤ 0,725 foram obtidas com apenas um descritor, possibilitando a identificação de algumas características estruturais relacionadas ao grau de oxidação. Não foi obtida nenhuma relação entre o grau de oxidação dos SL e a evolução das tribos da família Asteraceae. Os descritores moleculares também foram usados como dados de entrada para separar as ocorrências botânicas através de mapas auto-organizáveis (rede não supervisionada Kohonen). Os mapas gerados, com cada bloco de descritor, separaram as tribos da família Asteraceae com valores de índices de acerto total entre 66,7% e 83,6%. A análise desses resultados evidencia semelhanças entre as tribos Heliantheae, Helenieae, e Eupatorieae e, também, entre as tribos Anthemideae e Inuleae. Tais observações são coincidentes com as classificações sistemáticas propostas por Bremer, que utilizam principalmente dados morfológicos e, também, moleculares. A mesma abordagem foi utilizada para separar os ramos da tribo Heliantheae, segundo a classificação proposta por Stuessy, cuja separação é baseada no número de cromossomos das subtribos. Os mapas auto-organizáveis obtidos separam em duas regiões distintas os ramos A e C, com elevados índices de acerto total que variam entre 81,79% a 92,48%. Ambos os estudos demonstram que os descritores moleculares podem ser utilizados como uma ferramenta para classificação de táxons em níveis hierárquicos baixos, tais como tribos e subtribos. Adicionalmente, foi demonstrado que os marcadores químicos corroboram parcialmente com as classificações que empregam dados morfológicos e moleculares. Os descritores obtidos por fragmentos ou pela representação da estrutura dos SLs em duas dimensões foram suficientes para obtenção de resultados significativos, não sendo obtida melhora nos resultados com os descritores que utilizam a representação em três dimensões das estruturas. Paralelamente, um estudo adicional foi realizado relacionando a estrutura química, representada pelos mesmos descritores moleculares anteriormente mencionados, com a atividade citotóxica de 37 SLs frente às células tumorais da nasofaringe KB. Uma equação com índices estatísticos significativos (r2=0,826 e Qcv2=0,743) foi obtida. Os cinco descritores, selecionados a partir de uma equação estatisticamente mais significativa, representam uma descrição global de propriedades estéricas e características eletrônicas de cada molécula que auxiliaram na determinação de fragmentos estruturais importantes para a atividade citotóxica. Tal modelo permitiu verificar que os esqueletos carbônicos dos tipos guaianolídeo e pseudoguaianolídeo são encontrados nos SLs que apresentam maior atividade citotóxica. / This work describes the development of a new chemoinformatic tool named SISTEMATX that allowed the chemotaxonomic analysis of the Asteraceae family employing new molecular parameters, as well as the quantitative structure activity relationship study of compounds produced by this botanical group. The Asteraceae, one of the largest families among of angiosperms, is chemically characterized by the production of sesquiterpene lactones (SLs). A total of 1111 (SLs), extracted from 658 species, 161 genera, 63 subtribes and 15 tribes of the Asteraceae, were represented and registered in two dimensions in the SISTEMATX and associated with their botanical source. From this codification, the degree of oxidation and the structures in three dimensions of each SL were obtained by the system. These data linked with botanical origin were exported for a text file which allow the generation of several types of molecular descriptors. These molecular parameters were correlated with the average oxidation degree by tribe and were selected by multiple linear regressions using genetic algorithms. Equations with statistical coefficients varying between 0,725 ≤ r2 0,981 and 0,647 ≤ Qcv2 ≤ 0,725 were obtained with only one descriptor, making possible the identification of some structural characteristics related to the oxidation level. Any relationship between the degree of oxidation of SL and the tribes evolution of the family Asteraceae was not obtained. The molecular descriptors were also used as input data to separate the botanical occurrences through the self organizing-maps (unsupervised net Kohonen). The generated maps with each block descriptor, divide the Asteraceae tribes with total indexes values between 66,7% and 83,6%. The analysis of these results shows evident similarities among the Heliantheae, Helenieae and Eupatorieae tribes and, also, between the Anthemideae and Inuleae tribes. Those observations are in agreement with the systematic classifications proposed by Bremer, that use mainly morphologic and, also, molecular data. The same approach was utilized to separate the branches of the Heliantheae tribe, according to the Stuessys classification, whose division is based on the chromosome numbers of the subtribes. From the obtained self-organizing maps, two different areas (branches A and C) were separated with high hit indexes varying among 81,79% to 92,48%. Both studies demonstrate that the molecular descriptors can be used as a tool for taxon classification in low hierarchical levels such as tribes and subtribes. Additionally, was demonstrated that the chemical markers partially corroborate with the classifications that use morphologic and molecular data. Descriptors obtained by fragments or by the representation of the SL structures in two dimensions were sufficient to obtain significant results, and were not obtained better results with descriptors that utilize the structure representation in three dimensions. An additional study was accomplished relating the chemical structure, represented by the same molecular descriptors previously mentioned, with the cytotoxic activity of 37 SLs against tumoral cells derived from human carcinoma of the nasopharynx (KB). An equation with significant statistical indexes was obtained. The five descriptors, selected from the more statistical significant equation, shows a global description of sterical properties and electronic characteristics of each molecule that aid in the determination of important structural fragments for the cytotoxic activity. From the model can be verified that the carbon skeletons of the guaianolide and pseudoguaianolide types are encountered in the SLs that show the higher cytotoxic activity.
46

Exploration du potentiel biotechnologique des levures endémiques et indigènes de la Réunion et de Madagascar à produire des molécules d'arômes / No English title available

Grondin, Éric 07 November 2014 (has links)
Depuis quelques décennies, la communauté scientifique s'intéresse de plus en plus à la recherche de nouvelles levures pour de nouvelles applications dans le domaine des biotechnologies blanches. De l'étude de la biodiversité à l'étude des propriétés métaboliques, les recherches visant à sélectionner de nouvelles levures avec des propriétés intéressantes pour l'industrie se sont intensifiées. Localisées dans le Sud-Ouest de l'océan Indien, les îles de La Réunion et de Madagascar sont aujourd'hui considérées comme des Hot Spot de la biodiversité. La grande diversité de plantes et de fruits tropicaux fournis des habitats naturels pour la propagation de nombreux microorganismes tels que les levures. A l'instar de ce qui se passe chez les plantes endémiques, nous avons formulé l'hypothèse que certains microorganismes ne peuvent être trouvés nulle part ailleurs que dans ces îles tropicales. 101 souches de levures réparties en 26 espèces différentes ont ainsi été isolées dans cette étude à partir de 13 fruits tropicaux récoltés aléatoirement dans les régions d'Antsirabe à Madagascar et de St-Paul à La Réunion. L'identification des espèces a été réalisée par analyse des séquences des domaines D1/D2 de la grande sous-unité des gènes de l'ARN ribosomique (ARNr). Les souches caractéristiques ont ensuite fait l'objet d’une analyse systématique par micro-extraction en phase solide couplée à une analyse chromatographique en phase gazeuse et couplé à un spectromètre de masse (ET-MEPS-CPG/SM) pour déterminer leurs capacités à produire des arômes. Parmi elles, deux souches isolées sur le fruit du poc-poc (Physalis peruviana) et sur le cacao (Theobroma cacao var. Criollo) semblent appartenir à de nouvelles espèces, probablement endémiques de la zone géographique étudiée. En effet, ces souches, EGPOC17 et EB23, présentent un faible pourcentage d'identité avec les séquences de l'ARNr des levures Rhodotorula mucilaginosa (97,1% d'identité) et Candida pararugosa (97,4% d'identité). 52 composés organiques volatiles (COVs) différents, classés en cinq grandes classes de molécules, les acides, les alcools, les aldéhydes, les cétones et les esters ont ainsi été identifiés. Une analyse statistique a ensuite été réalisée pour tenter de classer ces souches par catégories en fonction de leurs caractéristiques métaboliques. Avec une production de 32 molécules différentes sur les 52 identifiées, la levure Saprochaete suaveolens (anciennement connue sous le nom de Geotrichum fragrans) est de loin la souche produisant le plus grand nombre de composés d'arômes, en particulier d'esters et de composés insaturés. D'autres souches comme Candida quercitrusa, Debaryomyces nepalensis, Pichia kluyveri et Sporidiobolus pararoseus semblent également être intéressantes pour la production d'acides, d'alcools et de cétones. Parmi les COVs identifiés, des composés comme le 2 méthylbut-2-énoate d'éthyle (tiglate d'éthyle), le 2-méthylbut-2-énoate de 3 méthylbutyle (tiglate d'isoamyle), le 2-méthylbut-2-énoate de butyle (tiglate de butyle), 3-méthylbut-2-énoate d'éthyle, 2-méthylbut-2-énoate de 2-méthylpropyle et le but-2-énoate d'éthyle ont été retrouvés spécifiquement chez la levure Saprochaete suaveolens. La présence de ces molécules, très peu décrites chez les levures dans la littérature, suggère des relations taxonomiques de type «arôme-espèce» ou «arôme-genre » chez les levures. / In recent years, there has been an increasing interest in identifying and characterizing the yeast ecosystems associated with diverse types of habitat because of the many potential desirable technological properties of these microorganisms, especially in food applications. In this study, a total of 101 yeast strains were isolated directly from the skins of tropical fruits collected in several locations in the South West Indian Ocean (in the regions of Anstirabe in Madagascar and Saint Paul in Reunion Island). Species identification was determined by sequence analysis of the D1/D2 domains of the large subunit (LSU) ribosomal RNA gene. The strains were classified into 26 different species and tested for their potential to produce aromatic flavouring compounds. Among the isolated strains, two species isolated from the skins of Cape gooseberry and Cocoa beans appeared to represent putative new yeast species. Strains EGPOC17 and EB23 showed LSU D1/D2 sequence homologies of only 97.1% and 97.4% with the yeasts Rhodotorula mucilaginosa and Candida pararugosa, respectively. In total, 52 Volatile Organic Compounds (VOCs) were detected by Head Space Solid Phase Micro Extraction coupled to Gas Chromatography and Mass Spectroscopy (HS-SPME-GC/MS) analysis and these were classified into five main groups, namely, acids, alcohols, aldehydes, ketones and esters. In order to classify and discriminate the yeast biodiversity, statistical analysis was performed which allowed the yeasts to be categorized according to their flavour production. With a production of 32 compounds among 52 VOCs, Saprochaete suaveolens (Geotrichum fragrans) seemed to be the best producer of flavour compounds, especially esters and unsaturated compounds. Other yeast species including Candida quercitrusa, Debaryomyces nepalensis, Pichia kluyveri and Sporidiobolus pararoseus also appeared of potential interest based on their abilities to produce acid, alcohol and carbonyl compounds. Among the VOCs detected, 6 uncommon compounds namely ethyl but-2-enoate, ethyl 2-methylbut-2-enoate (ethyl tiglate), ethyl 3-methylbut-2-enoate, 2-methylpropyl 2-methylbut-2-enoate, butyl 2-methylbut-2-enoate and 3 methylbutyl 2-methylbut-2-enoate were identified as possible yeast species specific flavour markers.
47

Flavonóides, cumarinas e benzofuranos como marcadores quimiotaxonômicos em Asteraceae / Flavonoids, coumarins and benzofuranes as chemotaxonomic markers in the Asteraceae

Brant, Antonio Jedson Caldeira 18 February 2003 (has links)
Este trabalho descreve as ocorrências naturais de flavonóides, cumarinas e benzofuranos na família de plantas, Asteraceae / Compositae. Tem como objetivo principal classificar os referidos metabólitos secundários como possíveis marcadores quimiotaxonômicos da família bem como fazer previsões de suas ocorrências naquela. Para sua realização, foi montado um banco de dados de ocorrências desses produtos naturais a partir da literatura especializada. Os números de ocorrências das três classes químicas (flavonóides, 4369;cumarinas, 961; benzofuranos, 628) foram avaliados através de programas computacionais. Com estes foram feitas matrizes de correlações, regressões lineares múltiplas, e gráficos variados. Foram também correlacionados os números de oxidação (NOXs) médios de cada classe química (exceto os dos benzofuranos, devido a algumas dúvidas suscitadas de sua rota biogenética) com a finalidade de estudos de passos evolutivos de táxons. Os resultados do estudo apontam alguns esqueletos carbônicos de cumarinas e benzofuranos que podem provavelmente servir como marcadores químicos em nível de tribos e subtribos da família. Quanto aos flavonóides, já são considerados, em nível infrafamiliar, como marcadores químicos alguns tipos de esqueletos carbônicos com padrões de substituição mais específicos. Foram montadas algumas equações empíricas capazes de prever ocorrências e NOXs das classes químicas envolvidas neste trabalho para as tribos e subtribos da família, com um grau de confiabilidade de 95%. Para este estudo usou-se como base taxonômica a classificação de Asteraceae mais recente de Bremer (1994). / This work describes the natural occurrences of flavonoids, coumarins and benzofurans in the family of plants, Asteraceae / Compositae. It has as main purpose to classify the referred secondary metabolites as possible chemotaxonomic markers of the family as well as to do predictions of occurrences of the latter. For its accomplishment, a database of occurrences of those natural products was set up from the specialized literature. The numbers of occurrences of the three chemical classes (flavonoids, 4369; coumarins, 961; benzofurans, 628) were appraised with use of statistical computacional programs. With aid of these were made correlation matrices of the occurrences, multiple linear regressions, numerous diverse diagrams. The average oxidation numbers (OXNs) of each chemical class (except the ones of the benzofurans, due to some doubts raised on their biogenetical route) were also correlated with the purpose of studies on evolutionary steps of the taxa. The results of the study point some carbon skeletons of coumarins and benzofurans that can probably serve as chemical markers at tribe and subtribe levels of the family. In relation to the flavonoids, these are already considered, at infrafamilial level, as chemical markers, especially some types of carbon skeletons bearing more specific substitution patterns. Were also mounted some empirical equations capable of predicting occurrences and average OXNs of the chemical classes involved in this work for the tribes and subtribes of the family, with a 95% reliability degree. For this work was also ulilized as taxonomic base the most recent classification of the Asteraceae of Bremer (1994a).
48

Análise Químico-Morfológica de Hyptis Jacq. e Hypenia (Mart. ex Benth.) R. Harley (Lamiaceae) / Chemomorphological analysis of Hyptis Jacq. and Hypenia (Mart. ex Benth.) R. Harley (Lamiaceae)

SILVA, Julierme Gonçalves da 13 April 2012 (has links)
Made available in DSpace on 2014-07-29T16:48:33Z (GMT). No. of bitstreams: 1 Tese Julierme_IQ_UFG_2012.pdf: 1572042 bytes, checksum: c5e12770e49c6a65ee23600c84379152 (MD5) Previous issue date: 2012-04-13 / Cerrado is the second largest Brazilian biome, occupying about 24% of the country. However, there are only 61% of preserved Cerrado areas. Therefore, studies are needed in order to preserve these natural resources. For this purpose the reassessment of systematic relationships between 88 taxa of Hyptis Jacq. were based on the vegetative and reproductive morphological characters (chapter 1). In order to perform a phenetic study, multivariate statistical analysis were used for determination of taxa distribution patterns. The relationships between the examined taxa have been expressed as Ward hierarchical clustering using multiple correspondence analysis of 50 characters distributed into 168 character states. The perceptual map shows a subdivision of Hyptis into two major clusters. Cluster I contained 41 taxa belonging to sections Cyanocephalus, Cyrta, Gymneia, Mesosphaeria, Polydesmia and Tricosphaeria which mainly showed elongated, elliptic, linear bracts, curvature of the calyx's tube upper limb, oblique calyx tube orifice, as well as smooth nutlets. Cluster II contained 47 taxa from sections Apodotes, Eriosphaeria, Hyptis, Induratae, Pachyphyllae, Pusilae and Xylodontes. Their main morphological characteristics included hemispheric or subglobose cymes, the presence of a stylopodium, slightly rough nutlets and nutlets truncate at apex. Cluster analysis focused on 6 of the morphological characters which were distinguished by discriminant correspondence analysis, revealed similar traits. Multivariate analyses were also applied in the essential oil chemovariations of 13 Hypenia species (chapter 2). The results revealed the presence of two taxonomic clusters. Cluster I included 3 species belonging to section Densiflorae in addition to H. subrosea Harley and H. aristulata (Epl.) R. Harley, and showed the highest percentages of α-muurolol (5.85 ± 3.08%). In Cluster II, which contained 8 species belonging to section Laxiflorae, the major discriminant constituents were (E)-caryophyllene (7.09 ± 4.88%), germacrene D (18.1 ± 11.4%) and bicyclogermacrene (6.65 ± 1.19%). All essential oils showed a predominance of sesquiterpenes, such as spathulenol (4.5-31.6%), caryophyllene oxide (2.2-14.4%) and selin-11-en-4α-ol (0-34.8%). Furthermore, identical clusters were revealed by multivariate analysis of chemical constituents based on carbon skeletons, as well as on 18 morphological leaf characters of the species studied. / O Cerrado é a segunda maior formação vegetal brasileira, ocupando 24% do território nacional. No entanto, restam apenas 61% de áreas preservadas de Cerrado. Desta forma, estudos para caracterização e preservação desta riqueza natural são necessários. Com este intuito, reavaliou-se a relação sistemática entre 88 espécies de Hyptis Jacq. com base em caracteres morfológicos e reprodutivos (capítulo 1). A análise estatística multivariada foi aplicada para determinar o padrão de distribuição dos taxa com o objetivo de se realizar uma análise fenética. As relações entre os taxa estudados foram expressas pelo agrupamento hierárquico de Ward utilizando a análise de correspondência múltipla com base em 50 caracteres distribuídos em 168 estados dos caracters. O mapa perceptual mostrou a subdivisão de Hyptis em duas grandes classes. A classe I foi formada por 41 taxa pertencentes às seções Cyanocephalus, Cyrta, Gymneia, Mesosphaeria, Polydesmia e Tricosphaeria, as quais demostraram brácteas linares alongadas e elípticas, curvatura do tubo do cálice acima do limbo, orifício do tubo do cálice oblíquo, bem como núculas suaves. A classe II contou com 47 taxa das seções Apodotes, Eriosphaeria, Hyptis, Induratae, Pachyphyllae, Pusilae e Xylodontes. Suas principais características morfológicas incluíram cimas hemisféricas ou subglobosas, presença de um estilopódio, núculas levemente rugosas e núculas truncadas no ápice. A análise de agrupamento focada em 6 dos caracteres morfológicos, previamente distinguidos pela análise de correspondência discriminante, revelou a mesma similaridade entre os taxa, sugerindo a divisão de Hyptis em 2 subgêneros. Procedeu-se também à análise multivariada da composição química dos óleos essenciais de 13 espécies de Hypenia (capítulo 2). Os resultados indicaram a presença de 2 grupos de óleos em relação às seções botânicas das amostras. O primeiro grupo (classe I) incluiu as 3 espécies da seção Densiflorae em adição a H. subrosea Harley e H. aristulata (Epl.) R. Harley, o qual foi caracterizado pelo maior percentual de α-muurolol (5,85 ± 3,08%). Na classe II, com 8 espécies da seção Laxiflorae, os principais constituintes discriminantes foram o (E)-cariofileno (7,09 ± 4,88%), germacreno D (18,1 ± 11,4%) e o biciclogermacreno (6,65 ± 1,19%). Todos os óleos essenciais apresentaram predominantemente sesquiterpenos, tais como espatulenol (4,5-31,6%), óxido de cariofileno (2,2-14,4%) e selin-11-en-4α-ol (0-34,8%). Os agrupamentos foram idênticos quando utilizada a análise multivariada baseada nos esqueletos carbônicos dos constituintes químicos ou utilizando 18 caracteres morfológicos das folhas das espécies.
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Estudos químico e biológico de espécies de hypericum das seções Brathys e Trigynobrathys / Phytochemical and biological study of the Hypericum species of the Brathys and Trigynobrathys sections

Barros, Francisco Maikon Corrêa de January 2013 (has links)
O gênero Hypericum (Guttiferae = Clusiaceae) compreende 494 espécies acomodadas em 36 seções taxonômicas. Os representantes americanos pertencem, sobretudo, às seções Brathys e Trigynobrathys, as duas maiores com 87 e 52 espécies, respectivamente. Popularmente, estas plantas são utilizadas como antissépticos, diuréticos, digestivos e agentes de cicatrização. Quimicamente, apresentam tendência em acumular floroglucinóis diméricos, além de benzofenonas, benzopiranos, flavonoides e ácidos fenólicos, metabólitos cuja atividade antidepressiva, antinociceptiva, antimicrobiana, antiproliferativa e antioxidante são descritas. Considerando o potencial terapêutico, este trabalho objetivou a determinação dos principais compostos fenólicos presente nas flores de espécies Hypericum nativas do Sul do Brasil (H. campestre, H. caprifoliatum, H. carinatum, H. connatum, H. linoides, H. myrianthum, H. polyanthemum e H. salvadorense) e dos Páramos peruanos (H. andinum e H. laricifolium); a extração e análise dos compostos fenólicos de H. carinatum obtidos com CO2 supercrítico e a investigação da atividade antifúngica e antiquimiotática dos extratos lipofílicos de H. caprifoliatum, H. carinatum, H. linoides, H. myrianthum e H. polyanthemum. Para os experimentos, foram coletadas (2008 - 2010) as partes aéreas das plantas em floração. Todas as coletas foram autorizadas pelos órgãos de proteção ambiental. Os métodos extrativos incluem maceração estática, ultrassom e CO2 supercrítico (temperatura = 40, 50 ou 60ºC; pressão = 90, 120, 150 ou 200 bar). As análises por CLAE foram realizadas em coluna de fase reversa (C18), sistemas isocráticos compostos por acetonitrila, água e ácido trifluroacético e detecção ultravioleta (220, 270 ou 254 nm); Os picos foram identificados pela comparação dos tempos de retenção/co-injeção com padrões e quantificados pela curva de calibração dos compostos. Os ensaios antifúngico e antiquimiotático foram realizados pelo método de microdiluição em caldo e inibição da migração de neutrófilos, respectivamente. O floroglucinol dimérico uliginosina B (0,008 – 0,188%) e o flavonoide hiperosídeo (0,057 – 5,987%) foram os principais metabólitos detectados nas flores das espécies investigadas. Hypericum caprifoliatum e H. andinum apresentaram o maior rendimento destes compostos, respectivamente. Sete espécies apresentaram japonicina A em concentrações de 0,003 a 0,087% (H. myrianthum). O rendimento de hiperbrasilol B variou de 0,006% em H. laricifolium a 0,011% em H. caprifoliatum. Os benzopiranos (HP1 = 0,200%, HP2 = 0,225% e HP3 = 0,327%) e as benzofenonas (carifenona A = 0,309% e carifenona B = 0,062%) ocorreram exclusivamente em H. polyanthemum e H. carinatum. As máximas quantidades de ácido clorogênico, isoquercitrina, quercitrina e guaijaverina foram observadas, respectivamente, em H. campestre (1,458%), H. andinum (1,161%), H. carinatum (0,231%) e H. laricifolium (0,404%). Tais resultados fornecem suporte adicional para o significado quimiotaxonômico dos derivados diméricos de floroglucinol. Temperatura (40°C = 3,04%, 50°C = 2,21% e 60°C = 1,05%) e pressão (90 bar = 0,95%, 150 bar = 0,97% e 200 bar = 1,89%) afetaram de modo distinto o rendimento do extrato supercrítico de H. carinatum. Apesar do menor rendimento em comparação ao extrato n-hexano (6,09%), a extração com CO2 supercrítico provou ser mais seletiva que a maceração. Nas condições ideais (40°C, 90 bar e 180 minutos), a máxima recuperação de uliginosina B, carifenona A e carifenona B foi, respectivamente, 162,83, 376,33 e 48,79%. O modelo matemático empregado para simular o processo de extração foi apropriadamente correlacionado aos dados experimentais. Considerando as atividades biológicas, todas as espécies investigadas apresentaram um amplo espectro de ação antifúngica, assim como reduziram a migração dos neutrófilos. Os extratos de H. carinatum, H. linoides e H. myrianthum apresentaram os mais baixos valores de concentração inibitória mínima contra Cryptococcus neoformans (CIM £ 15,6 μg/mL), Rhodotorula mucilaginosa (CIM £ 62,5 μg/mL), Candida glabrata e C. tropicalis (CIM = 1,9-250 μg/mL). Para estas plantas, o efeito antiquimiotático variou entre 60 - 100% nas concentrações de 0,31 a 10 μg/mL. Os extratos mais ativos apresentaram elevada concentração de uliginosina B, japonicina A e hiperbrasilol B. Assim, as espécies de Hypericum nativas do sul do Brasil apresentam potencial como fonte de novos antifúngicos e anti-inflamatórios. / The genus Hypericum (Guttiferae = Clusiaceae) comprises 494 species placed in 36 taxonomic sections. The representatives of Central and South America belong primarily to sections Brathys and Trigynobrathys, the two largest sections with 87 and 52 species, respectively. In traditional medicine, these plants are used as antiseptic, diuretic, digestive and as healing agents. Such species have a strong tendency to accumulate dimeric phloroglucinol, besides benzophenones, benzopyrans, flavonoids and phenolic acids, metabolites whose antidepressant, antinociceptive, antimicrobial, antiproliferative and antioxidant activities are described. In view of the therapeutic potential, this work aimed to determine the main phenolic compounds present in flowers of Hypericum species native to southern Brazil (H. campestre, H. caprifoliatum, H. carinatum, H. connatum, H. linoides, H. myrianthum, H. polyanthemum and H. salvadorense) and to Peruvian Páramos (H. andinum and H. laricifolium); the supercritical CO2 extraction and analysis of the phenolic compounds of H. carinatum; the antifungal and antichemotactic activities of the lipophilic extracts from H. caprifoliatum, H. carinatum, H. linoides, H. myrianthum and H. polyanthemum. For the experiments, aerial parts in blossom were harvested (2008 - 2010). All collections were authorized by competent agencies of environmental protection. The extraction methods employed were static maceration, ultrasonic bath or supercritical CO2 (temperature = 40, 50 or 60ºC; pressure = 90, 120, 150 or 200 bar). HPLC analyses were carried out in reverse phase column (C18), isocratic system composed of acetonitrile, water and trifluoroacetic acid, and ultraviolet detection (220, 270 or 254 nm). Peaks were identified by comparison of retention times / co-injection with standards and quantified by calibration curve of the compounds. Antifungal and antichemotactic tests were performed using the broth microdilution assay and neutrophils migration inhibition method. The dimeric phloroglucinol uliginosin B (0.008 - 0.188%) and the flavonoid hyperoside (0.057 - 5.987%) were the main metabolite detected in flowers of the investigated species. Hypericum caprifoliatum and H. andinum displayed higher yields of these compounds, respectively. Japonicin A was found in seven species studied at concentrations that varied from 0.003 to 0.087% (H. myrianthum). The yield of hyperbrasilol B ranged from 0.006% in H. laricifolium to 0.011% in H. caprifoliatum. The benzopyrans (HP1 = 0.200%, HP2 = 0.225% and HP3 = 0.327%) and benzophenones (cariphenone A = 0.309% and cariphenone B = 0.062%) occurred exclusively in H. polyanthemum and H. carinatum. Maximum amounts of chlorogenic acid, isoquercitrin, quercitrin and guaijaverin were observed, respectively, in H. campestre (1.458%), H. andinum (1.161%), H. carinatum (0.231%) and H. laricifolium (0.404%). Such results provide a further support for the chemotaxonomic significance of the dimeric phloroglucinols. Temperature (40°C = 3.04%, 50°C = 2.21% and 60°C = 1.05%) and pressure (90 bar = 0.95%, 150 bar = 0.97% and 200 bar = 1.89%) critical did affect differently the yield of supercritical extract of H. carinatum. Despite lower yield in comparison to n-hexane extract (6.09%), supercritical CO2 extraction proved to be more selective than maceration. In optimal conditions (40°C, 90 bar and 180 minutes), the maximum amount of uliginosin B, cariphenone A and cariphenone B was, respectively, 162.83, 376.33 and 48.79%. Lastly, the mathematical model used in the process of supercritical extraction was properly correlated to the experimental data. Regarding the biological activities, all investigated species exhibited a broad spectrum of antifungal action as well as reduced neutrophils migration. Hypericum carinatum, H. linoides and H. myrianthum extracts presented the lowest value of minimum inhibitory concentration against Cryptococcus neoformans (MIC ≤ 15.6 μg/mL), Rhodotorula mucilaginosa (MIC ≤ 62.5 μg/mL), Candida glabrata and C. tropicalis (MIC range = 1.9 - 250 μg/mL). For these plants, the antichemotactic effect varied from 60-100% at concentrations of 0.31 to 10 μg/mL. The most active extracts were that presented high amounts of uliginosin B, japonicin A and hyperbrasilol B. Thus, the Hypericum species native to Southern Brazil show potential as source of new anti-infectives and anti-inflammatory drugs.
50

Chemodiversity and Functions of Monoterpene Hydrocarbons in Conifers

Persson, Monika January 2003 (has links)
No description available.

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