• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 9
  • 3
  • Tagged with
  • 15
  • 4
  • 4
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 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.
11

Estudo da atividade moluscicida das plantas oriundas da Restinga de Jurubatiba

Souza, Eloísa Portugal Barros Silva Soares de 13 March 2017 (has links)
Submitted by Biblioteca da Faculdade de Farmácia (bff@ndc.uff.br) on 2017-03-13T19:47:55Z No. of bitstreams: 1 Souza, Eloísa Portugal Barros Silva Soares de [Dissertação, 2016].pdf: 2352165 bytes, checksum: 60f359e59fc6b6d7aae22ce45641b075 (MD5) / Made available in DSpace on 2017-03-13T19:47:55Z (GMT). No. of bitstreams: 1 Souza, Eloísa Portugal Barros Silva Soares de [Dissertação, 2016].pdf: 2352165 bytes, checksum: 60f359e59fc6b6d7aae22ce45641b075 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O estudo das plantas medicinais tem-se tornado uma importante fonte de pesquisa e interesse científico devido ao seu valor em nível de estrutura química e propriedades farmacológicas. A esquistossomose é um problema de saúde pública que atinge milhares de pessoas que vivem em áreas endêmicas. Por seu aspecto socioeconômico, devido à falta de saneamento básico eficiente em muitas áreas, está incluída entre as doenças negligenciadas. Seu tratamento é considerado eficaz, porém existe a necessidade de medidas profiláticas que reduzam o número de pessoas infectadas atendidas pelas redes de saúde coletiva. Dentre essas medidas, existe o combate ao hospedeiro intermediário do agente etiológico da doença, o caramujo de água doce do gênero Biomphalaria. Este molusco é crucial para a transmissão da doença, e seu controle iria interromper o ciclo da esquistossomose. O método de controle atualmente utilizado para este fim possui grande impacto ambiental, não sendo, portanto, uma alternativa viável. Nesse contexto, as plantas da Restinga de Jurubatiba possuem diversas atividades terapêuticas conhecidas popularmente ou cientificamente estudas. O uso de seus extratos pode ser uma importante estratégia para o controle do molusco e a consequente redução do número de pessoas que contraem a esquistossomose. O objetivo desse trabalho, portanto, é avaliar a atividade moluscicida dos extratos das plantas Eugenia sulcata, Manilkara subsericea, Neomitranthes obscura e Myrciaria floribunda, suas frações e substâncias isoladas, sobre a espécie Biomphalaria glabrata. Foi realizado o ensaio de atividade moluscicida para avaliar a letalidade dos extratos de plantas sobre a espécie Biomphalaria glabrata, em tempos de até 96 horas. E, para avaliar a toxidade dos extratos em células de linhagem, foram realizados ensaios de liberação da enzima lactato desidrogenase e redução da resazurina. Os resultados mostraram maior atividade moluscicida nas frações em hexano e diclorometano de Myrciaria floribunda, com valores de DL50 de 3,3 e 6,2 ppm respectivamente e, em menor escala, nos extratos brutos do caule de Neomitranthes obscura e Manilkara subsericea, e na fração acetato de etila desta última, da qual foram isoladas três substâncias: miricetina, quercetina e ácido ursólico, apresentando atividade moluscicida em menores concentrações, com valores de DL50 de 0,04 ppm, 0,08 ppm e 1,57 ppm respectivamente. Tais resultados não demonstraram toxidade em células de mamíferos. Este trabalho aponta para um foco de estudo para uma alternativa profilática para o controle do hospedeiro intermediário da esquistossomose mansônica. / The study of the medicinal plants has become a major source of research and scientific interest because of their value at the level of chemical structure and pharmacological properties. Schistosomiasis is a public health problem that affects thousands of people living in endemic areas. By their socioeconomic aspect, due to the lack of effective sanitation in many areas, it is included among the neglected diseases. The treatment is considered effective, but there is the need for effective preventive measures to reduce the numbers of infected people served by the public health networks. Among these measures, there is the fight against intermediate hosts of the disease, the freshwater snail Biomphalaria. This mollusk is crucial to the development of the disease and its control would stop the schistosomiasis cycle. The control method currently used for this purpose has a large environmental impact, and therefore not a viable alternative. In this context, plants from Jurubatiba sandbank have several therapeutic activities known popularly or scientifically studied. The use of its extracts may be an important strategy for the mollusk control and the consequent reduction in the number of people contracting schistosomiasis. The aim of this study, therefore, is to evaluate the molluscicidal activity of the extracts from plants Eugenia sulcata, Manilkara subsericea, Neomitranthes obscura and Myrciaria floribunda, its fractions and isolated compounds on the specie Biomphalaria glabrata. It carried out the molluscicidal activity assay to assess the lethality of plant extracts on Biomphalaria glabrata species at times up to 96 hours. In order to evaluate the toxicity of extracts of cell line were performed assays lactate dehydrogenase release and reduction of resazurin. The results showed higher molluscicidal activity in the fractions in hexane and dichloromethane of Myrciaria floribunda, with LD50 values of 3.3 and 6.2 ppm, respectively, and to a lesser extent, in stem crude extracts of Neomitranthes obscure and Manilkara subsericea, and the ethyl acetate fraction of the latter, from which three substances were isolated: myricetin, quercetin and ursolic acid, with molluscicidal activity at lower concentrations, with LD50 values of 0.04 ppm, 0.08 ppm and 1.57 ppm respectively. There is no toxicity in mammalian cells. This work points to a focus of study for a prophylactic alternative to control the intermediate host of schistosomiasis.
12

Estudo das atividades antinociceptiva, anti-inflamatória e antioxidante da Sideroxylon obtusifolium (Sapotaceae) / STUDY OF THE ANTINOCICEPTIVE, ANTI-INFLAMMATORY AND ANTIOXIDANT ACTIVITIES OF SIDEROXYLON OBTUSIFOLIUM (SAPOTACEAE)

Araújo Neto, Vitor 16 December 2009 (has links)
Sideroxylon obtusifolium belongs to the family Sapotaceae. This study aimed to contribute to the scientific knowledge of the antinociceptive, anti-inflammatory and antioxidant properties of the steam bark of Sideroxylon obtusifolium (Roem. & Schult.) T.D. Penn, popularly known as quixabeira and used to treat pain and inflammation. The ethanol crude extract of the dried and triturated stem bark (EE, 459,60 g) was submitted to liquidliquid extraction (400 g) with hexane, chloroform and ethyl acetate to give fractions hexane (11,90 g), chloroform (6,08 g), ethyl acetate (43,72 g) and hydromethanol (181,35 g). The EE and its fractions were submitted to phytochemical analysis, which detected groups of secondary metabolites such as phenols, flavanoids, xanthones, steroids, triterpens, saponins, tannins and cathechins. The effects of the extract and its fractions in nociception (using the models of abdominal writhing induced by acetic acid, hot plate and formalin in mice), inflammation (using the models of paw edema and peritonitis induced by carrageenan in mice) and antioxidant (using the scavenging of DPPH method) were evaluated. In the model of abdominal writhing induced by acetic acid, the oral treatment with of EE at 400 mg/kg had similar inhibition to that of AAS. The model of hot plate showed that the EE did not cause an increase in the latency time by the thermal stimulus at 55 ± 0.5°C, suggesting does not have central antinociceptive action. The EE only inhibited the second phase in the formalin test, which suggested that had inflammatory antinociception, which showed possibly acts by inhibiting the enzyme ciclo-oxygenase (COX). When evaluating the anti-inflammatory action by the carrageenan-induced paw edema model, the oral feeding of the EE was effective in reducing the edema-forming response between second and fourth hour after injecting carrageenan. Peritonitis model showed that the oral administration of EE was effective in reducing the leukocyte migration after 4 h of the i.p. injection of carrageenan, which was similar to dexamethasone. The DPPH assay showed the EE and its fractions ethyl acetate and hydromethanol present a antioxidant activity in vitro, which can be related to the presence of polyphenols. Therefore, the extract of S. obtusifolium has relevant phytochemical, which can be influencing the anti-inflammatory, analgesic, and antioxidant activities, suggesting it can be submitted to new pharmacological studies and clinical trial. / A planta escolhida pertence à família Sapotaceae. Este estudo teve como objetivo contribuir para o conhecimento científico das ações antinociceptiva, anti-inflamatória e antioxidante da entrecasca da Sideroxylon obtusifolium (Roem. & Schult.) T.D. Penn, popularmente conhecida como quixabeira e usada no tratamento da dor e inflamação. Para tanto, o extrato etanólico bruto (EE, 459,60 g) da entrecasca da planta seca e triturada foi submetido à extração líquido-líquido (400 g) com hexano, clorofórmio e acetato de etila, obtendo assim as frações hexânica (11,90 g), clorofórmica (6,08 g), acetato de etila (43,72 g) e hidrometanólica (181,35 g). Este extrato e suas frações foram submetidos à prospecção fitoquímica detectando assim grupos de metabólitos secundários relevantes, como fenóis, flavonóides, xantonas, esteróides, triterpenóides, saponinas, taninos e catequinas. Em seguida, foram avaliados os efeitos desse extrato na nocicepção (nos modelos de contorções abdominais induzida por ácido acético, placa quente e formalina em camundongos), inflamação (nos modelos de edema de pata e de peritonite induzidos por carragenina em ratos) e oxidação (método do seqüestro do DPPH). No modelo de contorções abdominais induzida por ácido acético, o EE quando administrado por via oral na concentração de 400 mg/kg apresentou inibição similar ao AAS. Já no modelo da placa quente o EE não influenciou no aumento do tempo de latência pelo estímulo térmico de 55 ± 0,5°C, sugerindo não tem ação antinociceptiva central. Observando o modelo da formalina o efeito do EE apresentou inibição apenas na segunda fase mostrando antinocicepção do tipo inflamatória, sugerindo ação através da inibição da ciclo-oxigenase (COX). Na avaliação da ação anti-inflamatória pelo modelo de edema de pata induzido por carragenina em ratos, demonstrou que a administração oral do EE foi efetivo em reduzir a resposta edematogênica entre a segunda e quarta hora após a injeção de carragenina. No modelo de peritonite demonstrou que o EE por via oral foi efetivo em reduzir a migração leucocitária após 4 h a injeção i.p. de carragenina de forma similar à dexametasona. O método do seqüestro do DPPH permitiu estabelecer a ação antioxidante in vitro do EE e das frações acetato de etila e hidrometanólica, que pode estar relacionada aos compostos polifenólicos presentes. Assim, identificamos que o extrato da S. obtusifolium possui compostos fitoquímicos que influenciaram nas atividades anti-inflamatória, analgésica e antioxidante.
13

Diversité et structuration génétique des sapotacées endémiques de l'archipel des Mascareignes à différentes échelles spatiales et temporelles / Diversity and genetic struture of endemic Sapotaceae from Mascarene archipelago at different spatial and temporal scales

Dafreville, Stéphanie 08 November 2013 (has links)
L'archipel des Mascareignes (Réunion, Maurice et Rodrigues) est, avec les Seychelles, les Comores et Madagascar, l'un des 34 « hotspots » de biodiversité reconnus à l'échelle mondiale. Dans un contexte de disparition des habitats par les activités humaines, l'objectif de la thèse a été de comprendre la dynamique évolutive à différentes échelles spatiales et temporelles d'une famille d'espèces indigènes des écosystèmes forestiers, les Sapotacées. Ces espèces arborées présentent une gamme diversifiée de niveaux d’endémisme, d'abondance, de modes de régénération et de caractéristiques biologiques. La famille des Sapotacées comprend 3 genres et 14 espèces indigènes des Mascareignes (Mimusops, Labourdonnaisia et Sideroxylon) dont certaines espèces, rares et protégées, sont endémiques d'une des trois îles de l'archipel des Mascareignes. À l'échelle de la famille, l'analyse des séquences chloroplastiques de la famille des Sapotacées a confirmé la forte différenciation entre genres avec deux clades. Le premier clade est constitué par toutes les espèces de Sideroxylon structurées en trois sous-clades distincts dont deux correspondent aux sections Eusideroxylon et Calvaria, montrant une diversité haplotypique importante. Le deuxième clade est constitué par deux sous-clades formés respectivement par les espèces de Labourdonnaisia et celles de Mimusops. Alors qu'il n'est pas possible de résoudre les relations de parenté des Mimusops, Labourdonnaisia présentent deux lignées évolutives soulevant une incongruence entre les données taxonomiques et phylogénétiques. À l'échelle des deux lignées du genre Sideroxylon (Sections Eusideroxylon et Calvaria), l'analyse des marqueurs microsatellites chloroplastiques a montré une forte diversité haplotypique à la fois chez des espèces communes comme S. borbonicum ou rares comme S. majus associé à différenciation marquée entre l'île Maurice et la Réunion au sein des deux lignées. De plus, il a été mis en évidence des patrons de structure de la diversité génétique différents selon l'île et l'espèce considérée : une structure spécifique dans le genre Sideroxylon de la section Calvaria à Maurice et une structure géographique chez S. cinereum de Maurice et les espèces réunionnaises. À l'échelle de la lignée des Sideroxylon de la section Calvaria, les marqueurs microsatellites nucléaires ont permis d'identifier clairement toutes les espèces avec une forte différenciation entre S. majus de la Réunion et l'ensemble des espèces mauriciennes. À Maurice, la différenciation est plus marquée entre S. grandiflorum et les deux autres espèces S. sessiliflorum et S. boutonianum avec des évènements d'hybridation entre ces deux dernières espèces possibles. À l'échelle de S. majus de la Réunion, une très forte diversité génétique structurée en trois groupes génétiques a été mise en évidence à l'aide de marqueurs microsatellites nucléaires. La comparaison de la diversité génétique des cohortes des adultes et des juvéniles ne présente pas d’érosion génétique. Des méthodes de conservation sont proposées en fonction de ces caractéristiques génétiques pour S. majus, espèce rare en danger. L'ensemble des résultats obtenus chez les Sapotacées endémiques des Mascareignes montre que la diversité génétique est structurée à différentes échelles spatiales, selon les espèces et les lignées évolutives considérées, soulignant la nécessité d'études complémentaires afin de déterminer les processus qui sont à l'origine des patrons détectés. / Madagascar is among the top five priorities "hotspots" for global biodiversity conservation. In Madagascar, melliferous flora is diverse and abundant; the endemic honey bee Apis melliferaunicolor inhabits all areas regardless of the climatic conditions and topography. As other islands, Madagascar is fragile and susceptible to invasions of alien species. In 2010, Varroa destructor has been reported parasitizing A. m. unicolor. The ectoparasite is not only a serious threat to beekeeping in Madagascar but it may also alter ecosystems balance.The objectives of this thesis were i) to study the genetic diversity and population structure of both A. m. unicolor and V. destructor in Madagascar, ii) to estimate the impact of V. destructor on honey bee colonies, and iii) to investigate the hygienic behaviour of honey beeOur results confirm that all honey bees collected in Madagascar belonged to the African evolutionary lineage and more than 99% were identified as A. m. unicolor. Despite its lownuclear genetic diversity, two genetic clusters have been detected, corresponding to geographic regions.In Madagascar, only one genetic strain of V. destructor was detected, the Korean haplotype (K1-1) which is the most widespread lineage in the world and the one present in Africa. Genetic studies showed a higher proportion of homozygous genotype (69.5%) and also a high number of MLG (Multi- Locus Genotypes) in the High Lands compared to the East coast. The presence of particular MLG on the High Land reinforces the assumption of its introduction into the capital. The spread of V. destructor in Madagascar is relatively slow in comparison with those observed in African countries. Its presence remains confined to the High Land and the East coast. The impact of the parasite on A. m. unicolor was severe; with about 60% of colony losses in a year reported in 2012. Nevertheless, this is less than observed in Europe, where many more colonies died at the early stage of infestation.Based on the percentage of cleaned cells observed 6 hour after pin killing the brood, the efficiency of A. m. unicolor colonies to detect and uncap cells was comparable to those of Africanised hygienic honey bees and was much higher than those of European honey bees. In Madagascar, the detection of highly hygienic colonies of A. m. unicolor is a great opportunity to develop a programme of selection of tolerant honey bee strains.
14

Estudo químico em resíduos madeireiros e florestais de espécies secretoras: Protium tenuifolium (Burseraceae) e Manilkara huberi (Sapotaceae)

Silva, Samirimi Januário, 92-99305-0988 19 July 2015 (has links)
Submitted by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2017-08-28T18:23:38Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação - Samirimi J. Silva.pdf: 1676841 bytes, checksum: 2e9d111400f09448ad0241d62b265c17 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2017-08-28T18:23:55Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação - Samirimi J. Silva.pdf: 1676841 bytes, checksum: 2e9d111400f09448ad0241d62b265c17 (MD5) / Made available in DSpace on 2017-08-28T18:23:55Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação - Samirimi J. Silva.pdf: 1676841 bytes, checksum: 2e9d111400f09448ad0241d62b265c17 (MD5) Previous issue date: 2015-07-19 / CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico / Protium (Burseraceae) and Manilkara (Sapotaceae) occur in the Amazon and show economic importance in the timber industry beyond the biological potential of its secondary metabolites. Considering the scarcity of studies on wood and forest residues of these genus, this study was evaluated from the chemical point of view, forest and wood residues of Protium tenuifolium and Manilkara huberi. Thus, the phytochemical study of the methanol extract of wood residues from Manilkara huberi led to the isolation of p-hydroxybenzaldehyde) and a new saponin triterpen identified as 2β, 3β, 6β, 28-tetrahydroxy-olean-12-en-23-oic ester 23-O-α-L-ramnosepyranosyl. In the hexane, extract of forest residues (branches) from Protium tenuifolium were identified the mixture α and β-amyrin (triterpenes) β-sitosterol and stigmasterol (steroids). The study of the methanol extract of this species resulted in the isolation of the unpublished polyketides in the Burseraceae family; known as integracin A and B. Identification of compound were based in NMR spectra uni and two-dimensional. The volatile constituents of the bark of P. tenuifolium were evaluated, the essential oil obtained by hydrodistillation and the chemical constituents analyzed by GC/FID and GC/MS. In the composition predominated the monoterpenes limonene (56.17%), α- phellandrene (16.22%) and ρ-cymene (10.52%). This study contributed significant to the chemical knowledge of Amazonian species studied, aggregating commercial, scientific and biological value to compounds identified in wood and forest residues. / Protium (Burseraceae) e Manilkara (Sapotaceae) ocorrem na Amazônia e apresentam importância econômica no setor madeireiro, além do potencial biológico dos seus metabólitos secundários. Considerando a escassez de estudos em resíduos madeireiros e florestais desses gêneros, neste trabalho foi avaliado do ponto de vista químico, resíduos florestais e madeireiros de Protium tenuifolium e Manilkara huberi. Assim, o estudo fitoquímico do extrato metanólico dos resíduos madeireiros de Manilkara huberi conduziu ao isolamento do p-hidroxibenzaldeído e de uma nova saponina triterpênica identificada como 2β,3β,6β,28-tetra-hidroxi-olean- 12-en-23-oico éster 23-O-α-L-ramnosepiranosil. No extrato hexânico de resíduos florestais (galhos) de Protium tenuifolium foram identificadas misturas de triterpenos (α e β- amirina) e de esteroides (β-sitosterol e estigmasterol). O estudo do extrato metanólico desta espécie resultou no isolamento de policetídeos inéditos na família Burseraceae, conhecidos como integracina A e Integracina B. A identificação das substâncias foram baseadas nos espectros de RMN uni e bidimensional. Os constituintes voláteis das cascas de P. tenuifolium foram obtidos por hidrodestilação e avaliados por CG/DIC e CG/EM. Na composição predominou os monoterpenos limoneno (56,17%), α-felandreno (16,22%) e ρ-cimeno (10,52%). O presente estudo contribuiu de maneira significante para o conhecimento químico das espécies amazônicas, agregando valor comercial, científico e biológico aos resíduos madeireiros e florestais.
15

The biogeographic affinities of the Sri Lankan flora

Kumarage, Lakmini Darshika January 2017 (has links)
The island of Sri Lanka’s exceptional biodiversity and enigmatic biogeography begs investigation, as the island is key in understanding the evolution of the Asian tropical flora. Since the Jurassic, Sri Lanka has been subjected to remarkable tectonic changes, thus its flora could have been influenced by that of a number of nearby landmasses, as well giving Sri Lanka the potential to have played a wider role in the assemblage of floras elsewhere. Firstly, as Sri Lanka originated as a fragment of the supercontinent Gondwana, part of its flora may contain Gondwanan relict lineages. There is also the potential for immigration from Laurasia after the Deccan Plate collided with it 45-50 Mya. Further, Sri Lanka may harbour floristic elements from nearby land masses such as Africa and Southeast Asia as a result of long distance dispersals, and in situ speciation has the potential to have played an important role in enhancing the endemic Sri Lankan flora. I tested the relative contributions of the above hypotheses for the possible origins of the Sri Lankan flora using three representative families, Begoniaceae, Sapotaceae and Zingiberaceae. These families represent both herbaceous and woody elements, and have high diversity across the tropics. Dated molecular phylogenies were constructed for each family. I used recent analytical developments in geographic range evolution modelling and ancestral area reconstruction, incorporating a parameter J to test for founder event speciation. A fine scale area coding was used in order to obtain a better picture of the biogeography of continental Asia. Amongst all the models compared, a dispersal-extinction cladogenesis model incorporating founder event speciation proved to be the best fit for the data for all three families. The dates of origin for Sri Lankan lineages considerably post-date the Gondwanan break up, instead suggesting a geologically more recent entry followed by diversification of endemics within the island. The majority of Sri Lankan lineages have an origin in the Sunda Shelf (53%). Persistence of warm temperate and perhumid climate conditions in southwestern Sri Lanka resembling those of Peninsular Malaysia and Sumatra could have facilitated suitable habitats for these massive dispersals from the Sunda Shelf region. Some trans-oceanic long distance dispersals from Africa (11%) are also evidenced, again these are too young to accept a hypothesis of dispersal during the Deccan Plate’s migration close to the African coast during the late Cretaceous, but occurred later during the Miocene. Further, some lineages of Laurasian origin (20%) are evidenced in the Zingiberaceae with ancestral areas of China and Indochina, which is congruent with a post collision invasion. Among the families tested, dispersals have occurred stochastically, one during the Eocene, six during the Oligocene, seven during the Miocene, two during the Pliocene and one during the Pleistocene. The highest number of dispersals occurred during the Miocene when a warm climate was prevailing during the Miocene thermal maximum. My results confirm that in situ speciation is an important contributor to the Sri Lankan flora. More rapid radiation of endemics has occurred during Pliocene-Pleistocene; two endemics in Begoniaceae, ten endemics in Sapotaceae and ten endemics in Zingiberaceae have evolved in situ during this period. Sri Lanka will have been subjected to expansion and contraction of climatic and vegetation zones within the island during glacial and interglacial periods, potentially resulting in allopatric speciation. As a conclusion, long distance dispersals have played a prominent role in the evolution of the Sri Lankan flora. The young ages challenge the vicariant paradigm for the origin and current disjunct distributions of the world’s tropical lineages and provide strong evidence for a youthful tropics at the species level. The thesis contains six chapters; first two are introductory chapters, then there are three analytical chapters, one for each family, and finally a summary chapter is provided. Each analytical chapter is written as a stand-alone scientific publication, thus there is some repetition of relevant content in each.

Page generated in 0.0313 seconds