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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

Comparação citogenética entre populações de Prochilodus argenteus Spix & Agassiz, 1829 (Characiformes, Prochilodontidae) a montante e a jusante da UHE de Três Marias, Bacia do São Francisco, Minas Gerais, Brasil / Cytogenetic comparison between populations of Prochilodus argenteus Spix & Agassiz, 1829 (Characiformes, Prochilodontidae) upstream and downstream of the UHE Três Marias, the São Francisco Basin, Minas Gerais, Brazil

Ferreira, Frederico Fernandes 24 July 2015 (has links)
Submitted by Amauri Alves (amauri.alves@ufv.br) on 2015-11-17T09:30:03Z No. of bitstreams: 1 texto completo.pdf: 971904 bytes, checksum: 6fba372a708197c45ace38066444f048 (MD5) / Made available in DSpace on 2015-11-17T09:30:03Z (GMT). No. of bitstreams: 1 texto completo.pdf: 971904 bytes, checksum: 6fba372a708197c45ace38066444f048 (MD5) Previous issue date: 2015-07-24 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Prochilodus argenteus, a curimatá-pacu, juntamente com a sua espécie irmã, Prochilodus costatus, representam cerca de 50% da biomassa total da pesca, sendo as espécies migratórias mais abundantes na região de Três Marias e ambas endêmicas da bacia do rio São Francisco. A construção de hidrelétricas altera o ambiente e o fluxo gênico entre populações que podiam não estar isoladas no passado. Desta forma, o objetivo deste estudo foi verifica se existem diferenças citogenéticas entre populações de Prochilodus argenteus que podem ter ficado isoladas pela barragem de Três Marias, bacia do rio São Francisco, Minas Gerais, Brasil, desde final da década de 1950. Foram coletados 44 espécimes: 14 a montante da represa, perto da cidade de Iguatama, e 30 a jusante (24 no Refugio Estadual da Vida Silvestre do rio Pandeiros e seis no município de Três Marias). O número diploide de 2n=54 e a fórmula cariotípica 40m + 14sm foram encontrados em todos os indivíduos. Em ambas as populações foram encontrados os seguintes padrões: a banda C apresentou blocos heterocromáticos centroméricos em todos os cromossomos, além de um bloco adicional pericentromérico no segundo par metacêntrico; a Ag-NOR evidenciou marcações simples no segundo par metacêntrico, coincidindo com a constrição secundária. Em aproximadamente 5% das metáfases ocorreu uma terceira marcação na região terminal de apenas um cromossomo. A técnica de Fluorescent in situ Hybridization (FISH) utilizando as sondas 18S e 5S rDNA evidenciou sintenia destas regiões no segundo par metacêntrico, coincidentes com a NOR e a constrição secundária. As sondas repetitivas (GA) 15 e (CA) 15 apresentaram marcações na região telomérica de todos os cromossomos e a sonda (CA) 15 evidenciou blocos na região pericentromérica no quarto par metacêntrico, sugerindo a ocorrência de inversão cromossômica. As sondas (CAA) 10 e (CAT) 10 apresentaram marcação na região telomérica na maioria dos braços cromossômicos e, de forma mais difusa, ao longo de alguns cromossomos. Com base nestes padrões, conclui-se que as populações, hoje isoladas pela UHE de Três Marias desde a década de 50, não sofreram diferenciação citogenética e podem ser consideradas como uma população única. / Prochilodus argenteus, the curimatá-pacu, along with its sister species, Prochilodus costatus represent about 50% of the total biomass of fish, and migratory species more abundant in the area of Three Marias, both endemic to the São Francisco River basin. The construction of hydroelectric dams changes the environment and precludes gene flow between populations that were not isolated in the past. Thus, the aim of this study was to determine if there cytogenetic differences between populations of Prochilodus argenteus that became isolated by the Três Marias Dam, São Francisco Basin, Minas Gerais, Brazil, since late 1950s. Forty-four specimens were collected: 14 upstream of the dam, near the city of Iguatama, and 30 downstream (24 in the Refugio Estadual da Vida Silvestre do rio Pandeiros and six in the Três Marias Dam channel). We found a stable karyotype formula of 40m + 14sm, 2n=54. The following patterns were observed in both populations: The C banding showed centromeric heterochromatin blocks in all chromosomes, plus an additional pericentromeric block in the second chromosome metacentric pair. The nucleolus organizer regions (Ag-NOR) occurred on the second metacentric pair, coinciding with the secondary constriction. About 5% of the metaphases showed a third mark in the telomeric region of only one chromosome complements. The Fluorescent in situ Hybridization (FISH) with the 18S and 5S rDNA probes revealed synteny of these regions on the second metacentric pair, coinciding with the NOR and the secondary constriction. The (GA) 15 and (CA) 15 repetitive DNA probes showed markings on the terminal region of most chromosomes, and the (CA) 15 repetitive DNA probe hybridized in the pericentromeric region of the fourth chromosome pair, suggesting a chromosomal inversion. The (CAA) 10 and (CAT) 10 repetitive DNA probes hybridized on the terminal region of most chromosome arms and along some chromosomes. Based on these cytogenetic patterns, we concluded that the populations now isolated by UHE Três Marias since the 50’s did not suffer cytogenetic differentiation and should be considered as a single population.
2

Etude phytochimique de deux Dipterocarpaceae de la forêt thaïlandaise : Hopea odorata Roxb. et Dipterocarpus costatus Gaertn.f. / Phytochemical screening of two Thai tropical rainforest Dipterocarps : Hopea odorata Roxb. and Dipterocarpus costatus Gaertn.f.

Satiraphan, Malaï 27 September 2012 (has links)
Les extraits n-hexaniques respectivement des feuilles d’Hopea odorata Roxb. et du bois de Dipterocarpus costatus Gaertn.f. ont été sélectionnés sur la base d’un criblage biologique préliminaire. Ces extraits présentent des activités cytotoxiques significatives sur les lignées MCF-7 (cancer du sein) et NCI-H187 (cancer du poumon non à petite cellule). De plus, l’extrait du bois de D. costatus inhibe la croissance de la souche K1 de Plasmodium falciparum. L’étude phytochimique de l’extrait n-hexanique des feuilles d’Hopea odorata a permis d’isoler 19 composés terpéniques dont 16 triterpènes des séries lupane (n=8), (3,4-seco)cycloartane (n=4), friedélane (n=2) et oléanane (n=2). Parmi les lupanes, l’acide 3,30-dioxolup-20(29)-èn-28-oïque a été isolé pour la première fois d’une source naturelle. L’évaluation de l’effet de ces lupanes sur la croissance de quatre lignées cancéreuses humaines (PC3, MDA-MB-231, HT-29 and HCT116) a permis d’identifier des composés actifs et d’apporter des éléments de relations structure-activité tels que l’influence du degré d’oxydation des positions C-3, C-28 et C-30 sur la cytotoxicité. Parmi les cycloartanes, deux nouveaux 3,4-secocycloartanes ont été identifiés. Il s’agit de deux esters d’acide gras saturés et de l’acide (24S, 25S, 26)-trihydroxy-3,4-secocycloart-4(29)-èn-3-oïque. Par ailleurs, l’étude phytochimique de l’extrait n-hexanique du bois de Dipterocarpus costatus a permis d’isoler 31 terpènes dont 12 nouveaux triterpènes, parmi lesquels 5 norlupanes, 3 dammaranes, 2 nordammaranes et 2 secodammaranes. Les activités biologiques de l’ensemble des composés isolés, ont été évaluées sur la croissance des lignées cancéreuses humaines précédemment citées et de muscle squelettique de rat L-6, ainsi que sur la croissance de la souche K1 du Plasmodium falciparum. En particulier, le norlupane 36 possédant une fonction endoperoxyde, montre une forte activité antiplasmodiale associée à une faible cytotoxicité. / Preliminary study of the extracts from Hopea odorata leaves and Dipterocarpus costatus wood showed that the hexane extracts of both plants exhibited cytotoxicity against breast cancer (MCF-7) and small cell lung cancer (NCI-H187), in conjunction with potent antimalarial (against Plasmodium falciparum K1 strain) activity of D.costatus wood hexane extract. Phytochemical studies of H. odorata leaves hexane extract led to the isolation of 16 terpenoids in the series lupane (n = 8), (3,4-seco) cycloartane (n = 4), friedelane (n = 2) and oleanane (n = 2). Among lupanes, 3,30-dioxolup-20(29)-en-28-oic acid was isolated for the first time from a natural source. Cytotoxicity of lupanes triterpenes against four human cancer cell lines (PC3, MDA-MB-231, HT-29 and HCT116) was evaluated and showed the structure activity relationship related to the oxidation degree at position 3, 28 and 30. Among cycloartanes two new 3,4-seco-cycloartanes were identified. They are saturated fatty acid esters of (24S,25S,26)-trihydroxy-3,4-seco-cycloart-4(29)-en-3-oic acid. Isolation of D. costatus wood hexane extract discovered 31 terpenoids of which 12 triterpenes are new, including 5 norlupanes, 3 dammaranes, 2 nordammaranes and 2 secodammaranes. The biological activities of all isolated compounds were evaluated through cytotoxicity against human cancer cell lines mentioned above and rat myoblast-derived cells L-6, as well as antimalarial activity against Plasmodium falciparum K1 strain. Interestingly, the norlupane 36, possessing an endoperoxide group, showed a strong antiplasmodial activity associated with low cytotoxicity.

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