Orientador : Prof. Dr. Obdulio Gomes MiguelTese (doutorado) - Universidade Federal do Paraná, Setor de Ciências da Saúde, Programa de Pós-Graduação em Ciências Farmacêuticas. Defesa: Curitiba, 11/11/2010Inclui referênciasÁrea de concentração: Insumos, medicamentos e correlatosResumo: Acacia podalyriifolia A. Cunn. ex G. Don, Leguminosae-Mimosoideae, e uma especie exotica, vastamente difundida no Sul do Brasil. Avaliacoes fitoquimicas demonstraram flavonoides, taninos, compostos fenolicos e esteroides/triterpenoides nas flores; alcaloides, cumarinas, flavonoides, taninos, compostos fenolicos, quinonas e esteroides/triterpenoides nas folhas. Para o conteudo de compostos fenolicos, utilizando o reativo de Folin Ciocalteu, a fracao acetato de etila das flores e das folhas demonstrou os maiores teores. As fracoes hexanica, diclorometano e acetato de etila e o residuo dos extratos etanolicos das lores e das folhas foram submetidos a metodos cromatograficos para o isolamento de substancias. Como substancias fenolicas majoritarias foram obtidas as flavanonas 5- -glicosil-naringenina e naringenina, e a ƒÀ-dicetona 16, 18 tritriacontanodiona. As analises da atividade antibacteriana (bioautografia, difusao em disco e concentracao inibitoria minima) demonstraram ser mais ativa a fracao acetato de etila das flores e das folhas, inibindo cepas bacterianas gram positivas e gram negativas, em graus variaveis. Para as substancias isoladas, nas concentracoes testadas, apenas a naringenina foi ativa. Para a acao antioxidante, utilizando o radical livre 2,2-difenil, 1-picrilhidrazil (DPPH), formacao do complexo fosfomolibdenio e o teste TBARS, destaque especial tambem apresentou a fracao acetato de etila, demonstrandose ate mais ativa que os padroes utilizados, dependendo da tecnica que foi utilizada. As flavanonas isoladas tambem demonstraram atividade, ainda que em menor grau que suas fracoes originarias; para a 16, 18 ritriacontanodiona esta atividade foi muito discreta. Na avaliacao de toxicidade geral pela Artemia salina, a fracao diclorometano obtida das flores demonstrou ser a mais citotoxica nestes ensaios. Sobre o potencial alelopatico, observado nas sementes de Lactuca sativa, variedade Baba, para as amostras obtidas das flores e das folhas, embora nao tenham afetado a germinacao desta plantula, ocasionaram significativas influencias no seu crescimento, quando comparadas ao controle. As substancias isoladas tambem apre entaram efeitos significativos no crescimento, contribuindo na atividade alelopatica verificada com as suas fracoes de origem.Abstract: Acacia podalyriifolia A. Cunn. ex G. Don, Leguminosae-Mimosoideae, is an exotic species, widely distributed in southern Brazil. Phytochemical evaluations performed showed the presence of flavonoids, tanines, phenolic compounds and steroids/terpenoids in the flowers, while the material obtained from the leaves were ascertained alkaloids, coumarins, flavonoids, tanines, phenolic compounds, quinones, and steroids/terpenoids. In determining the content of phenolic compounds using the Folin Ciocalteu reagent, the ethyl acetate fractions from the flowers and the leaves had presented the greatest content of phenolic ompounds. The hexane, dichloromethane and ethyl acetate fractions and the residue which precipitated in the obtaining of ethanol extracts from the flowers and leaves were submitted to chromatographic methods for the isolation of substances. As isolated and identified phenolic major compounds from the flowers and the leaves were obtained the flavanones 5- -D-glicosil-naringenine and naringenine, and the ƒÀ-diketone denominated 16, 18 tritriacontanedione. The analysis of antibacterial activity, carried out by bioautography, disk diffusion and minimum inhibitory concentration proved that the ethyl acetate fraction obtained from both the leaves and flowers, is the most active, inhibiting gram positive and gram negative bacterial strains, in degrees variable depending on the strain used. For the isolated compounds, in the evaluated concentrations, only naringenin has demonstrated antibacterial action. For the antioxidant activity, pe formed by the methodologies which employ the free radical 2,2-diphenyl-1- picrylhydrazyl (DPPH), hosphomolybdenum complex formation and TBARS test, it should be specially noted that it also showed the ethyl acetate fraction, demonstrating to be even more active than the standards used, depending on which technique was used. The isolated flavanones demonstrated antioxidant activity, although lower than the played by the original fractions; for the 16, 18 tritriacontanedione, this activity was very slight. In the evaluation of general toxicity using the Artemia salina, the dichloromethane fraction obtained from the flowers proved to be the most cytotoxic in these assays. Regarding the allelopathic potential observed on the seeds of Lactuca sativa, variety gBaba h, against the samples obtained from flowers and leaves, although it has not affected the germination of seedlings, caused significant influences on the growth when ompared to control. The isolated compounds presented significant effects on seedling growth, contributing to the allelopathic activity observed with their origin fractions
