| Name: | Description: | Size: | Format: | |
|---|---|---|---|---|
| 4.09 MB | Adobe PDF |
Advisor(s)
Abstract(s)
As plantas medicinais africanas são o medicamento tradicional mais comum em prática em todo o
continente africano. Em muitas partes de África, as plantas medicinais são o recurso de saúde mais
acessível e disponível para a comunidade. Um exemplo típico é a utilidade das folhas de Maytenus
Senegalensis em Angola para a cura de doenças gastrointestinais, como diarreia e cólera, de dores
de dentes e de casos de malária associados a dores gastrointestinais. Estes pressupostos
proporcionaram o estudo fitoquímico e a análise biológica dos extratos de hexano das folhas de M.
senegalensis. Para tal, as folhas colhidas no município da Humpata foram submetidas a processos
de extração em n-hexano, acetona e etanol, e os extratos obtidos foram purificados por processos
cromatográficos, obtendo diversas frações de acordo com o poder de eluição. Estas frações foram
analisadas por técnicas espetroscópicas como a espectroscopia de infravermelho, de RMN de 1H e
de 13C, cuja análise dos resultados permitiu identificar alguns compostos. Os extratos de acetona
e etanol foram submetidos a avaliação biológica por determinação da atividade antioxidante pelo
método do DPPH (2,2-difenil-1-picrilhidrazilo). Depois das análises dos resultados espetroscópicos
foi possível identificar cinco compostos do extrato de n-hexano, nomeadamente, a Friedelin, a ß-
Amirina, o ß-Sitosterol, o ácido a-eleostearíco e o 3-Epi-gloquidiol. Estes resultados foram
confirmados com o auxílio de diversas fontes de literatura, uma vez que os dados obtidos neste
trabalho foram comparados com os referenciados na bibliografia, confirmando que os compostos
em causa já tinha sido identificados na mesma espécie ou em espécies diferentes. Os resultados
da avaliação da atividade biológica indicaram uma capacidade antioxidante forte para os extratos
de acetona e etanol em comparação com os padrões Trolox e Rutina, e um caráter fraco em relação
ao padrão do ácido gálico. Dos extratos analisados o de etanol apresentou maior atividade
antioxidante. Tendo em conta os resultados obtidos podemos sugerir a utilização destes extratos
como agentes que proporcionam um aumento da capacidade antioxidante frente a certas doenças
como o cancro, doenças cardíacas e acidentes vasculares cerebrais no Homem.
African’s medicinal plants are the most common traditional medicine in practice across the African continent. In many parts of Africa, medicinal plants are the most accessible health resource available to the community. A typical example is the use of Maytenus Senegalensis leaves in Angola for treating gastrointestinal diseases, such as diarrhea and cholera, toothache and malaria associated with gastrointestinal pain. These assumptions are the base for the phytochemical study and biological analysis of the n-hexane extracts of the leaves of M. senegalensis. For this, the leaves harvested in Humpata were subjected to extraction processes in n-hexane, acetone and ethanol, and the extracts obtained were purified by chromatographic processes, in which were obtained several fractions according to the elution power. These fractions were analyzed by spectroscopic techniques such as infrared, 1H and 13C NMR spectroscopy, whose analysis of the results allowed to identify some compounds. The acetone and ethanol extracts were submitted to biological evaluation by determination of the antioxidant activity by the DPPH (2,2-diphenyl-1- picrylhydrazyl) method. After the spectroscopic analysis, it was possible to identify five compounds of the n-hexane extract, which are, Friedelin, ß-Amyrin, ß-Sitosterol, a-eleostearic acid and 3-Epiglochidiol. These results were confirmed by several sources of literature, once the data obtained in this research were compared with those referenced in the literature, confirming that the compounds in question had already been identified in the same species or in different species. The results of the evaluation of the biological activity indicated a strong antioxidant capacity for the extracts of acetone and ethanol in comparison with the standards Trolox and Rutine, and a weak character against the standard gallic acid. Of the extracts analyzed, the ethanol showed higher antioxidant activity. Taking into account the results obtained we can suggest the use of these extracts as agents that provide an increase in antioxidant capacity against certain diseases such as cancer, heart disease and stroke in the human species.
African’s medicinal plants are the most common traditional medicine in practice across the African continent. In many parts of Africa, medicinal plants are the most accessible health resource available to the community. A typical example is the use of Maytenus Senegalensis leaves in Angola for treating gastrointestinal diseases, such as diarrhea and cholera, toothache and malaria associated with gastrointestinal pain. These assumptions are the base for the phytochemical study and biological analysis of the n-hexane extracts of the leaves of M. senegalensis. For this, the leaves harvested in Humpata were subjected to extraction processes in n-hexane, acetone and ethanol, and the extracts obtained were purified by chromatographic processes, in which were obtained several fractions according to the elution power. These fractions were analyzed by spectroscopic techniques such as infrared, 1H and 13C NMR spectroscopy, whose analysis of the results allowed to identify some compounds. The acetone and ethanol extracts were submitted to biological evaluation by determination of the antioxidant activity by the DPPH (2,2-diphenyl-1- picrylhydrazyl) method. After the spectroscopic analysis, it was possible to identify five compounds of the n-hexane extract, which are, Friedelin, ß-Amyrin, ß-Sitosterol, a-eleostearic acid and 3-Epiglochidiol. These results were confirmed by several sources of literature, once the data obtained in this research were compared with those referenced in the literature, confirming that the compounds in question had already been identified in the same species or in different species. The results of the evaluation of the biological activity indicated a strong antioxidant capacity for the extracts of acetone and ethanol in comparison with the standards Trolox and Rutine, and a weak character against the standard gallic acid. Of the extracts analyzed, the ethanol showed higher antioxidant activity. Taking into account the results obtained we can suggest the use of these extracts as agents that provide an increase in antioxidant capacity against certain diseases such as cancer, heart disease and stroke in the human species.
Description
Keywords
Atividade Antioxidante e Dpph. Fitoquímica Maytenus Senegalensis Medicina Tradicional Africana Plantas Medicinais