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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.
1

Isolation and characterization of frullanolide from Frullania franciscana (Howe)

Sass, Marshall Stuart 01 January 1981 (has links)
Investigation of the ether extract of the liverwort Frullania franciscana (Howe) resulted in the isolation of the sesquiterpene lactone frullanolide. The separation techniques of thin-layer chromatography, dry column chromatography, and liquid column chromatography were evaluated. Only liquid column chromatography was found useful. Fractions from alumina liquid column separations had infrared spectra which resembled the published spectrum of frullanolide. The identity of the compound obtained from F. franciscana (Howe) was established after extensive purification by comparison of its infrared and nuclear magnetic resonance spectra with published spectra of frullanolide.
2

Palinologia de Frullaniaceae Lorch ( Marchantiophyta) do Brasil

Silva, Juliana da Costa 13 February 2015 (has links)
Submitted by isabela.moljf@hotmail.com (isabela.moljf@hotmail.com) on 2017-08-29T15:01:55Z No. of bitstreams: 0 / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-08-30T14:38:04Z (GMT) No. of bitstreams: 0 / Made available in DSpace on 2017-08-30T14:38:04Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-02-13 / As hepáticas são plantas avasculares, criptogâmicas, com alternância de gerações heteromórficas em seu ciclo de vida e constituem uma linhagem monofilética, a divisão Marchantiophyta. Nessas plantas, o estabelecimento no ambiente ocorre através de reprodução assexuada ou sexuada, mas a produção e a germinação dos esporos permitem a colonização de novos ambientes e substratos. Possuem gametófitos folhosos ou talosos, achatados dorsiventralmente, rizóides unicelulares e esporófitos aclorofilados. As Frullaniaceae Lorch compreendem hepáticas folhosas, medianas a robustas, com características que podem ser interpretadas como adaptação ao epifitismo, como lóbulos sacados, seta curta e germinação endospórica. Estão representadas pelo gênero Frullania Raddi, com 38 espécies no Brasil. O presente trabalho teve por objetivos realizar o estudo palinológico das espécies de Frullaniaceae, através de estudos morfológicos e ultraestruturais dos esporos; analisar as estratégias ecológicas das espécies estudadas, relacionando-as à morfologia dos esporos e acompanhar os estágios germinativos e o desenvolvimento dos esporos de Frullania ericoides (Nees) Mont, sob diferentes concentrações do meio de cultura. Os resultados obtidos permitem observar que os esporos das espécies da família Frullaniaceae possuem tamanho do diâmetro maior variando de médio a grande (33,3 a 63,3 micrômetros). Foram observados dois tipos morfológicos distintos baseados na elaboração da ornamentação da superfície dos esporos. A espessura dos estratos do esporoderma permitiu separação das espécies em subgrupos, que não refletiram a classificação taxonômica atual. A germinação de F. ericoides foi endospórica, com divisão e proliferação celular, formando um protonema globoso, com ocorrência tardia da quebra da parede do esporo. Ao longo do período do estudo, os esporos submetidos aos tratamentos de concentração mais fraca apresentaram melhores resultados quanto ao desenvolvimento do protonema. Os filídios primordiais são fortemente côncavos, com margem inteira e parede celular fina. Os resultados deste estudo demonstraram a importância taxonômica e o potencial das técnicas de culturas de tecidos para os estudos de germinação de esporos de briófitas. / Liverworts are nonvascular and cryptogamic plants, with heteromorphic alternation of generations in their life cycle, consisting on a monophyletic lineage, the division Marchantiophyta. In these plants, establishment occurs by asexual or sexual reproduction, but the production and germination of spores enables colonization of new habitats and substrates. Marchantiophyta differ from the others divisions by leafy or thallose gametophyte, dorsi-ventral orientation, unicellular rhizoids and non chlorophyllous sporophytes. Frullaniaceae Lorch include leafy liverworts, median to robust, highly branched, with features that can be interpreted as adaptation to epiphytism, such as saccate lobes, short seta and intracapsular germination. The family includes cosmopolitan species, but it’s more diverse in the tropics. There is one genus, Frullania Raddi, with 38 species in Brazil. This study aimed to perform palynological study of Frullaniaceae species through morphological and ultrastructural studies; and to evaluate the relationship of the features of the spores to ecological strategies of species, and to follow germination and sporeling development in Frullania ericoides (Nees) Mont., under different concentrations of culture media. The spores of Frullaniaceae species have larger diameter with size ranging from medium to large (33.3 to 63.3 micrometers). Two distinct morphological types, based on the spore surface ornamentation, were observed and are not related to the taxonomic organization of the family. The thickness of sporoderm strata allowed the separation of the species into two large groups, which also did not confirm the taxonomic classification. The germination was endosporic, showing cell division and proliferation, forming a globose protonema, without spore wall break. Throughout the period of study, the spores undergo the lowest concentration treatments showed better results of development. Primordial leaves are highly concave, with entire margins and a thick cell wall. The results of this study demonstrate the taxonomic importance and the potential of tissue culture techniques for bryophyte spore studies.

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