• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 10
  • 4
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 1
  • 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

Chemical Constituents and Biological Activities of the Formosan Soft Coral Cladiella hirsuta

Chang, Shu-ming 08 September 2009 (has links)
Chemical investigation of the soft coral Cladiella hirsuta, collected off the coast of Penghu Islands, has led to the isolation of natural products including ten new compounds hirsutalins A-D (1, 2, 3, 5) and hirsutosterols A-F (6, 7, 8, 9, 10, 11), and one known compound 3-butanoyloxycladiell-11(17)-en-6,7-diol (4). All of the chemical structures were established by detailed spectral data analysis (NMR, IR, MS) and by comparison of the spectral data with those of the related known compounds. The absolute structure of compound 1 was determined applying a modified Mosher¡¦s method. On the part of the cytotoxicity assay with six human cancer cell lines, HepG2 (liver cancer cell), Hep3B (liver cancer cell), Ca9-22 (mouth cavity cancer cell), A549 (lung cancer cell), MCF7 (breast cancer cell) and MDA-MB-231 (breast cancer cell), compound 5 showed the significant cytotoxicity against the cancer cell line HepG2; compound 7 showed the moderate cytotoxicity against all of the above cancer cell lines; compounds 6, 8 and 10 also showed the moderate cytotoxicity against two of them, Hep3B and Ca9-22. The products 6a and 7a , obtained by hydorlysis of 6 and 7, respectively, did not show obvious difference in cytotoxity by comparison of the IC50 values of compounds 6 and 7. On the part of anti-inflammation assay, compound 2 showed the effectively inhibiting activity against the induced iNOS and COX-2 proteins. Compound 3 showed nearly the same activity against the induced iNOS protein as that of 2.
2

Reproductive biology of the endangered plant, Phlox hirsuta (E.E. Nelson)

Filipski, Jules. January 2005 (has links) (PDF)
Thesis (M.S.) --Southern Oregon University, 2005. / "A thesis submitted to the Department of Biology and the Graduate School of Southern Oregon University in partial fulfillment of the requirements for the degree of Master of Science in Science." Includes bibliographical references (p. 69-75) Also available via Internet as PDF file through Southern Oregon Digital Archives: http://soda.sou.edu. Search Bioregion Collection.
3

Isolierung, Strukturaufklärung und stereochemische Untersuchungen von sesquiterpenoiden Inhaltsstoffen aus ätherischen Ölen von Bryophyta und höheren Pflanzen

Saritas, Yücel. January 2000 (has links) (PDF)
Hamburg, Universiẗat, Diss., 2000.
4

Rôles fonctionnels des gènes CUC et MIR164A au cours du développement foliaire chez Arabidopsis thaliana et sa proche relative Cardamine hirsuta / Functional role of the CUC and MIR164A genes during leaf development of Arabidopsis thaliana and its relative Cardamine hirsuta

Hasson, Alice 04 May 2012 (has links)
Une grande diversité de formes foliaires caractérise le monde végétal. Cette diversité s'étend des feuilles simples avec des marges lisses aux feuilles composées, avec des marges disséquées. Cependant, les dentelures des marges de ces feuilles simples ou composées se développent en suivant un mécanisme similaire. Ce mécanisme repose sur l'action des gènes NO APICAUX MERISTEM/ CUP-SHAPED COTYLEDONS (NAM/CUC) ainsi que sur la voie auxinique. Chez Arabidopsis, qui possède des feuilles simples, un équilibre entre les expressions de CUC2 et de son répresseur, miR164, est nécessaire au bon développement des dents. Nous avons montré qu'un autre membre de la famille CUC, CUC3, contribue également au développement de ces dents chez Arabidopsis. Bien que son action soit principalement dépendante de CUC2, il agit également plus tard au cours du développement foliaire. En outre, nous avons démontré qu'une boucle de rétro-contrôle entre CUC2 et la voie auxinique permet le développement de dents avec plus ou moins marquées. Nous avons également montré qu'un modèle d'expression temporelle existe entre l'auxine et le module CUC2-miR164. En outre, la production de plantes transgéniques de Cardamine hirsuta, un proche parent d' Arabidopsis, qui possède des feuilles composées, a mis en évidence l'importance des éléments cis-régulateurs dans le promoteur de CUC1 de Cardamine hirsuta. En effet, la divergence de ces éléments cis-régulateurs entre les promoteurs de CUC1 de Cardamine hirsuta et d' Arabidopsis pourrait expliquer que CUC1 soit fortement exprimé dans les feuilles de Cardamine hirsuta alors qu'il est faiblement exprimé dans celles d' Arabidopsis. / A wide diversity of leaf shapes characterises the plant world. This diversity ranges from simple leaves with smooth margins to compound leaves with dissected margins. However, all serrations of simple or compound leaf margins are developed using a similar mechanism. This mechanism includes the action of the NO APICAL MERISTEM/CUP-SHAPED COTYLEDON (NAM/CUC) genes as well as the auxin pathway. In Arabidopsis simple leaves, a balanced expression of CUC2 and its repressor miR164 is controlling the serrations development. We have shown that another member of the CUC family, CUC3, also contributes to the serration development in Arabidopsis simple leaves. While its action is mainly dependent of the one of CUC2, it also acts later during leaf development. Additionally, we have demonstrated that a feed-back loop was regulating the CUC2 and auxin pathways, in order to form leaves with more or less incisions. We also shown that a temporal expression pattern was established between the auxin and the CUC2-miR164 module. Moreover, generation of transgenic Cardamine hirsuta plants, a close relative of Arabidopsis, that possesses compound leaves, has enlighten the importance of cis-regulatory elements in the promoter of CUC1 from Cardamine hirsuta. Indeed, the divergence of cis-regulatory elements between promoters of CUC1 from Cardamine hirsuta and Arabidopsis could explain that CUC1 is expressed strongly in Cardamine hirsuta leaves whereas it is weakly expressed in Arabidopsis leaves.
5

Estudo do comportamento eletroquímico de nitrofenil-1,4-diidropiridinas e do diazoderivado da β-lapachona, compostos de interesse biológico / Perfil Metabolômico e Farmacológico da Mansoa hirsuta D.C. (BIGNONIACEAE)

Ferreira, Danielle Cristhina Melo 12 May 2004 (has links)
Two compounds of the class nitrophenyl-1,4-dihydropyridines (1 and 2), one from the quinone class - the β-lapachone (3) and one diazoquinone (4), the β- lapachone-derivative were analyzed by electrochemical methods. For the 1,4- dihydropyridines, the techniques used were cyclic voltammetry and square wave voltammetry, in aprotic (DMF + TBAP) and protic media (phosphate buffer, pH 6.9), on Hg and vitreous carbon electrodes. β-lapachone and its diazoderivative were studied in aprotic and protic media, using vitreous carbon as the working electrode. The reduction of the substituted nitrophenyl-1,4-dihydropyridines in protic medium, on both Hg and vitreous carbon electrodes showed electrochemical behavior typical of nitroaromatics, represented by one intense irreversible wave indicative of a 4e-/4H+ reduction process, with formation of the correspondent hydroxylamines, that showed different degrees of stability. In aprotic medium, the cyclic voltammograms showed, for 1, a first one-electron reversible wave corresponding to the generation of the nitro anion-radical, and a second irreversible wave that presented a complex mechanism, with the formation of reactive reduced intermediates. The acid (-COOH) derived nitrophenyldihydropyridine showed a more complex electrochemical feature, representative of an EC mechanism, with evidence of self-protonation. The electrochemical behavior of β-lapachone, in aprotic medium, was similar to the one of typical o-quinones and was represented by two one-electron waves, with reversible and quasi-reversible nature. However, the diazo derivative showed a different behavior, with only one reduction wave, without the anodic counterpart. The reduction mechanism corresponds to an EC process, with the irreversible electron transfer occurring at the diazo group, followed by a chemical reaction that involves the unimolecular loss of N2, generating the carbene anion radical. After successive protonations, the phenolic derivative (5) was obtained, as the main reduction product. The cyclic voltammogram reduction of the diazo derivative in protic medium (phosphate buffer, pH 6.9) showed only one wave without the anodic counterpart in potential of 0.419 V, differently from what is observed for o-quinones. Compound 4 didn t show antibacterial activity. / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Dois compostos da classe nitrofenil-1,4-diidropiridina (1 e 2), um da classe das quinonas - a β-lapachona (3) e uma diazoquinona derivada da β-lapachona, (4), foram analisados eletroquimicamente. Para as nitrofenil-1,4-diidropiridinas foram utilizadas as técnicas de voltametria cíclica e voltametria de onda quadrada, em meio aprótico (DMF + TBAP 0,1 mol/L) e prótico (tampão fosfato, pH 6,9), em Hg e carbono vítreo. Já a β-lapachona e seu diazoderivado foram estudados em meio prótico e aprótico, com o uso, como eletrodo de trabalho, de carbono vítreo. A redução das nitrofenil-1,4-diidropiridinas substituídas, em meio prótico tanto em eletrodo de Hg como em carbono vítreo, seguiu padrão de comportamento eletroquímico típico de nitrocomposto aromático, representado por uma onda intensa de natureza irreversível, indicativa de um processo de redução de 4e-/4H+, com formação de derivados hidroxilamínicos de diferentes estabilidades. Já em meio aprótico, os voltamogramas cíclicos evidenciaram, para a primeira delas (1), uma onda monoeletrônica, de caráter quase reversível correspondendo à geração do ânion-radical nitro e uma segunda onda irreversível apresentando mecanismo complexo, com formação de intermediários reduzidos reativos. A substância com grupamento ácido na molécula (-COOH) apresentou reação química acoplada após a primeira transferência eletrônica, em mecanismo típico de auto-protonação. O comportamento eletroquímico da β-lapachona, em meio aprótico, mostrouse similar ao de o-quinonas padrão, representado por duas ondas monoeletrônicas, uma de natureza reversível e outra quase-reversível. O diazo derivado da β- lapachona (4) apresentou comportamento diferente, com uma única onda de redução, sem correspondente anódica. O mecanismo de redução corresponde a um processo EC, onde a captura monoeletrônica irreversível ocorre no grupo diazo e a reação química acoplada envolve a perda unimolecular do N2, com geração do ânion radical carbeno intermediário, que após protonações sucessivas produz o derivado fenólico (5), majoritariamente. O voltamograma cíclico em meio prótico (tampão fosfato pH 6,9) de 4 apresentou uma única onda de redução sem contrapartida anódica em potencial de -0,419 V. O composto 4 não apresentou atividade antibacteriana.
6

Perfil metabolômico e farmacológico da Mansoa hirsuta D.C. (Bignoniaceae) / Metabolomic and pharmacological profile of Mansoa hirsuta D.C. (Bignoniaceae)

Silva, Daniel de Melo 06 August 2010 (has links)
Mansoa hirsute (Bignoniaceae), popularly known as Cipo d'álho, is chemically little known, although it is popularly used in the treatment of many disesases. The present studiy aimed to study the biological potential of the extracts and fractions obtained from leaves of M. hirsuta, to isolate and purify the active principles and to study the metabolomics of the plant. Plant materials were collected in five different regions from Semi-Arid in northeastern Brazil and were submitted to classic phytochemistry and analysis of the metabolomics. For that, the brute extract of the plants of Gentio do Ouro was obtained by extraction with ethanol 96% and was submitted to partitioning with different solvents, while the volatile were extracted by Clavenger apparatus. The isolated compounds were identified by GC-MS and NMR. Extract and subfractions were submitted to biological tests to clarify their possible biological activities. The brute extracts of the plants provenientes of the five regions was submitted to NMR analysis RMN to adquire 1D 1H and 2D COSY and J-resolved spectra. NMR data were submitted to chemiometry (HCA, PC and PSL-of the) to classify the species according to their metabolome. Pentacyclic triterpenes ursólico and oleanolic acids, and the steroids stigmasterol, ß-stitosterol and lupeol were isolated, together with dialyl sulfide and trialyl sulfide. The ethyl acetate fraction was able to inhibit the production of NO (57.92%) and proliferation of linfocites (99.92%), while the acid ursólico and oleanolic presented inhibition values greater than 99%. Metabolic analysis allowed to establish that plants of Gentio do Ouro are rich in pentacyclic triterpens, while plants from Boninal contains mostly flavonoids in its chemical composition. The results also suggest that protoantocianidinas are the main constituents of the plants from Caetité, while saponinas are found in the plants from Campo Alegre de Lourdes. Plants of Morro do Chapéu were distinguished form the other regions for being rich in oligosaccharides and aminoacids. / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A espécie Mansoa hirsuta (Bignoniaceae), popularmente conhecida como Cipó d'alho, é quimicamente pouco conhecida, embora seja popularmente utilizada no tratamento de muitas infecções. O presente trabalho objetivou estudar o potencial biológico dos extratos e frações obtidos das folhas de M. hirsuta, isolar e purificar os possíveis princípios ativos e estudar o perfil metabolômico da planta. O material vegetal foi coletado em cinco regiões diferentes do Semi-Árido nordestino e foi submetido à fitoquímica clássica e análise metabolômica. Para tanto, o extrato bruto das plantas de Gentio de Ouro foi obtido pela extração com etanol 96% e submetido a fracionamento com diferentes solventes, enquanto os voláteis foram extraídos por Clavenger. Os compostos isolados foram identificados por GC-MS e dados de RMN. O extrato e as subfrações foram submetidos a testes biológicos para esclarecer suas possíveis atividades biológicas. Os extratos brutos das plantas provenientes das cinco regiões foi submetido a análise por RMN para obtenção de espectros 1D 1H e 2D COSY e J-resolvido. Os dados provenientes do RMN foram então submetidos à métodos quimiométricos (HCA, PCA e PSL-DA) com vistas a classificar as espécies de acordo com seu metaboloma. Os triterpenos pentacíclicos ácidos ursólico e oleanólico e os esteróides estigmasterol, β-stitosterol e lupeol foram isolados, juntamente com o dissulfeto de dialila e trissulfeto de dialila. A fração acetato de etila inbiu a produção de NO (57,92%) e a linfoproliferação (99.92%), enquanto os ácidos ursólico e oleanólico apresentaram valores de inibição maiores que 99%. A análise metabólica permitiu estabelecer que as plantas oriundas de Gentio de Ouro são ricas em triterpernos pentacíclicos, enquanto as plantas de Boninal contêm principalmente flavonóides em sua composição química. Os resultados também sugerem que as protoantocianidinas são os principais constituintes das plantas oriundas de Caetité, enquanto saponinas são encontradas na plantas de Campo Alegre de Lourdes. As plantas de Morro do Chapéu diferem daquelas das demais regiões por serem ricas em oligossacarídeos e aminoácidos.
7

The phylogeography and systematics of Cardamine hirsuta

Cooke, Elizabeth Laura January 2013 (has links)
<b>Cardamine hirsuta</b> L. is an emerging model system in developmental genetics, where natural genetic variation within <b>C. hirsuta</b> provides the means to investigate the genetic basis of morphological traits. This thesis investigates the geographical structure and genealogical history of genetic variation within <b>C. hirsuta</b> and identifies its closest relatives. This will enable the accurate selection of species for comparison with <b>C. hirsuta</b> when making interpretations of evolutionary processes, and provide a better understanding of morphological character evolution in <b>C. hirsuta</b>. The phylogeographic history of <b>C. hirsuta</b> was reconstructed using multiple chloroplast and nuclear markers and widespread accession sampling from across its native range. A distinct group was identified within <b>C. hirsuta</b>, restricted to the high mountains of East Africa. Climate suitability modelling showed that Pleistocene glacial dynamics have had a strong effect on the distribution of genetic variation within <b>C. hirsuta</b>. The phylogeographical data generated here was used to investigate the origin of <b>C. hirsuta</b> in the Azores, an oceanic archipelago. The Azores are dominated by an endemic chloroplast haplotype which is associated with an endemic phenotype. Thus, <b>C. hirsuta</b> appears to have diversified <b>in situ</b> in the Azores. Phylogenetic analyses of Cardamine, restricted to diploid species to remove the confounding effects of polyploids, found that <b>C. hirsuta</b> is most closely related to <b>C. oligosperma</b>, a western North American species. Multiple loci and extensive intraspecific sampling were brought to bear to demonstrate that <b>C. hirsuta</b> and <b>C. oligosperma</b> are reciprocally monophyletic. <b>Cardamine pattersonii</b>, a restricted endemic from north-west Oregon is likely to be an allopolyploid, with <b>C. oligosperma</b> as the maternal parent and possibly <b>C. nuttallii</b> as the paternal parent.
8

Revize ontogeneze trilobita Sao hirsuta Barrande, 1846 z kambria ČR / Ontogeny of Sao hirsuta (Barrande, 1846) in the Cambrian of Czech Republic: revision

Laibl, Lukáš January 2012 (has links)
The Solenopleurid trilobite Sao hirsuta Barrande, 1846 is known from "Middle" Cambrian sedimentary rocks of the Czech Republic, Germany and Spain. It is one of the first trilobites on which ontogenetic development was described in detail (Barrande, 1852). This diploma thesis is the first modern revision of the ontogeny of this species for more than fifty years. Thesis is primarily based on quantitative methods and a detailed study of morphology of the exoskeleton. Changes in the dorsal exoskeleton during ontogenetic development of S. hirsuta, including the discovery of intrainstar morphological and size variability and the transition from isometric growth to the alometric growth, were described in detail by using quantitative methods (biometric measurements and geometric morphometrics). In the protaspid period different instars of S. hirsuta were recognized. Detailed morphological studies revealed several different morphotypes of protaspid stages. Some of which may represent different taxa. The morphology and the condition of the hypostome was described, including changes of hypostome during ontogeny. The study of segmentation in the species S. hirsuta shows hypoprotomeric development with the initial accumulation phase, middle equilibrium phase and terminal depletion phases. Key words: Sao...
9

The developmental and genetic basis of explosive pod-shatter in Cardamine hirsuta

Sarchet, Penny January 2012 (has links)
Dispersal is a key trait across biology. Within plants, a variety of explosive seed dispersal mechanisms are seen. Whilst ecological and mechanical studies have described this important evolutionary adaptation in many species, a genetic and developmental understanding of explosive seed dispersal is lacking. In this thesis, the morphology and development of the explosive seed pods of Cardamine hirsuta – a member of the Brassicaceae – are characterised in detail, with reference to its close relative, the model organism A. thaliana. Comparison of fruit morphology between these two species and across other Brassicacean species generated hypotheses regarding the function and polarity of morphological features. In order to identify genes that are necessary for C. hirsuta fruit development, a genetic screen was conducted and a range of mutants identified and subsequently characterised. Analysis of the indehiscent valveless (val) mutant revealed a loss of valve tissue and an expansion of valve margin identity in the silique. Mapping and sequencing identified a mutation in the MADS-box gene FRUITFULL (FUL), which results in a truncated protein, as the likely cause of the val phenotype. Consideration of ful mutants in C. hirsuta and A. thaliana allowed comparison of the genetic patterning of the fruit dehiscence zone in these two species. The genetic interactions between fruit mutants characterised in this thesis and mutants in shoot patterning genes revealed common regulatory networks underlying leaf and fruit development in C. hirsuta. Together, comparison of wild-type and mutant C. hirsuta siliques with those of A. thaliana and other Brassicacean species suggests that specialised cell layers within the valve silique region are of key importance to C. hirsuta’s explosive dehiscence mechanism.
10

Uncovering the genetic basis of natural variation of leaf form in Cardamine hirsuta

Lamb, Jonathan January 2015 (has links)
A major goal in biology is to understand the genetic basis of morphological variation at different evolutionary scales, for example between and within species. Here I investigate this issue by using plant leaves as an example. Previously comparative studies between the simple leaf model plant Arabidopsis thaliana and its dissected leaf relative Cardamine hirsuta have shown that inter-specific differences in leaf shape mostly result from variation in local tissue growth and patterning (Vlad et al., 2014; Hay et al., 2006; Barkoulas et al., 2008). Here, I aim to elucidate the genetic basis of natural variation in leaf form within species, by using divergent strains of C. hirsuta. I present evidence that variation in six strains collected from geographically diverse locations results from different rates of progression of an age-dependent leaf development programme in a phenomenon known as heteroblasty. By using Quantitative trait loci (QTL) mapping with a recombinant inbred line (RIL) population derived from a cross between the Oxford and Azores strains, I detected six QTL that influence leaflet production on multiple leaves. A QTL located on the 4th linkage group was validated and selected for further analysis. Characterisation of QTL effect indicated that the QTL influences leaf form by altering the rate of heteroblastic development. Subsequently I fine mapped this QTL to a DNA segment of 48 kb containing the gene SQUAMOSA PROMOTER PROTEIN BINDING LIKE 9 (ChSPL9), a previously characterised regulator of age dependent development. The parental alleles of ChSPL9 show variation in their sequence and were transformed into A. thaliana to evaluate whether they contribute to the QTL effect. Resultant phenotypes mirrored the QTL effect suggesting that ChSPL9 does indeed contribute to this QTL effect. These results indicate that age-dependent leaf shape progression underlies variation in leaflet number within species and more broadly suggest that in the case of plant leaves different processes might underlie morphological variation between and within species.

Page generated in 0.0444 seconds