| Name: | Description: | Size: | Format: | |
|---|---|---|---|---|
| 8.14 MB | Adobe PDF |
Authors
Advisor(s)
Abstract(s)
Em Cabo Verde há uma forte prática da medicina tradicional, mas verifica-se pouca
informação sobre a composição química de algumas espécies endémicas usadas nesse tipo
de terapia. Esse facto motivou o desenvolvimento deste tema dissertativo. Os objetivos
principais são (i) analisar a composição química de duas plantas de uso tradicional da
medicina popular selecionadas da flora Cabo-verdiana, nomeadamente o Campylanthus
glaber Benth ssp glaber e a Globularia amygdalifolia Webb; (ii) realizar extratos em
solventes de diferentes polaridades; (iii) proceder ao fracionamento, purificação e isolação
dos seus princípios bioativos. Para a identificação e caracterização dos compostos presentes
nas plantas procedeu-se à extração sólido – líquido, usando-se três solventes a frio, por
ordem crescente de polaridade: n-hexano, acetona e etanol. Na caracterização dos
componentes isolados, as suas estruturas foram completamente elucidadas por técnicas
comummente utilizadas no campo da fitoquímica, tais como: a Espectrometria de Massa
(MS), a Ressonância Magnética Nuclear (RMN), o Infravermelho (IV), o fracionamento em
cromatográfico em coluna (CC), a cromatografia em camada fina (CCF) e a cromatografia
gasosa com espectrómetro de massa (GC-MS).
No estudo efetuado sobre as folhas de Campylanthus glaber Benth ssp glaber verificouse
que para além dos compostos principais e maioritários como o Esqualeno (55,17 %),
Hentriacontano (37,82%; 31,20%) e o octadecanal (27,51%), misturas de triacilglicerois,
cetona artemisa (79,79 %) e de a-tecoferol (Vitamina E) (75,41 %), estas apresentam uma
serie de compostos como esteres metílicos, hidrocarbonetos, triterpenoides, fitoesteróis ,
ácidos fenólicos, ácidos gordos e álcoois gordos de cadeia linear de interesse químico e
biológico. Relativamente ao estudo fitoquímico da espécie Globularia amygdalifolia Webb,
foram identificados nos extratos de hexano os compostos maioritários ß-sitosterol (87,46%),
handianol (cicloartenol), dihidrocalisterol, ß-dihidrofucosterol e ácido z,z-9,12-
octadecadienóico , 9, 12, 15 octadecatrienoato de metilo e 9, 12 octadecadienoato de
metilo. No estudo efetuado ao extrato de acetona solúvel em clorofórmio e da análise
efetuada nas frações obtidas por RMN de 13C e de 1H, verifica-se a existência de um único
composto em toda a fração, a globularina, um derivado do catalpol, formado por um iridoide
e uma unidade de glucose.
Portanto, este é o primeiro estudo sobre a caracterização dos compostos dos extratos
de hexano e de acetona para estes géneros. Deste modo, espera-se que os resultados desta
pesquisa representem um passo para a realização de mais estudos sobre a atividade biológica
dos constituintes químicos presentes nas espécies em apreço.
In Cape Verde there is a strong practice of traditional medicine, but there is little information on the chemical composition of some endemic species used in this type of therapy. This fact motivated the development of this dissertation theme. The main objectives are to (i) analyze the chemical composition of two traditional folk medicine plants selected from Cape Verdean flora, namely Campylanthus glaber Benth ssp glaber and Globularia amygdalifolia Webb; (ii) perform extracts in solvents of different polarities; (iii) to fractionate, purify and isolate its bioactive principles. For the identification and characterization of the compounds present in the plants, solid-liquid extraction was carried out using three cold solvents, in increasing order of polarity: n-hexane, acetone and ethanol. In the characterization of the isolated components, their structures were completely elucidated by techniques commonly used in the field of phytochemistry, such as Mass Spectrometry (MS), Nuclear Magnetic Resonance (NMR), Infrared (IR), Column chromatography (CC), Thin Layer Chromatography (TLC), and Mass Spectrometry Gas Chromatography (MS-GC). In the study carried out on the leaves of Campylanthus glaber Benth ssp glaber, it was verified that in addition to the main and major compounds such as Squalene (55.17%), Hentriacontane (37.82%, 31.20%) and octadecanal (79.79%) and a-tecoferol (Vitamin E) (75.41%), these present a series of compounds such as methyl esters, hydrocarbons, triterpenoids, phytosterols, phenolic acids , fatty acids and linear chain fatty alcohols of chemical and biological interest. In the hexane extracts, the major compounds were identified as ß-sitosterol (87.46%), handianol (75.84%), dihydrochalisterol (49.73%), ß- sitosterol dihydrofucosterol (50.85%) and z, z-9,12-octadecadienoic acid (33.32%), methyl 9,12,15-octadecatrienoate (17.25%) and methyl 9,12-octadecadienoate (16.39% %). In the study carried out on acetone extract soluble in chloroform and the analysis performed on the fractions obtained by 13C and 1H NMR, there is a single compound in the whole fraction, globularin, a derivative of catalpol, formed by a iridoid and a glucose unit. Therefore, this is the first study on the characterization of hexane and acetone extract compounds for these genera. Thus, it is expected that the results of this research represent a step towards further studies on the biological activity of the chemical constituents present in the species under consideration.
In Cape Verde there is a strong practice of traditional medicine, but there is little information on the chemical composition of some endemic species used in this type of therapy. This fact motivated the development of this dissertation theme. The main objectives are to (i) analyze the chemical composition of two traditional folk medicine plants selected from Cape Verdean flora, namely Campylanthus glaber Benth ssp glaber and Globularia amygdalifolia Webb; (ii) perform extracts in solvents of different polarities; (iii) to fractionate, purify and isolate its bioactive principles. For the identification and characterization of the compounds present in the plants, solid-liquid extraction was carried out using three cold solvents, in increasing order of polarity: n-hexane, acetone and ethanol. In the characterization of the isolated components, their structures were completely elucidated by techniques commonly used in the field of phytochemistry, such as Mass Spectrometry (MS), Nuclear Magnetic Resonance (NMR), Infrared (IR), Column chromatography (CC), Thin Layer Chromatography (TLC), and Mass Spectrometry Gas Chromatography (MS-GC). In the study carried out on the leaves of Campylanthus glaber Benth ssp glaber, it was verified that in addition to the main and major compounds such as Squalene (55.17%), Hentriacontane (37.82%, 31.20%) and octadecanal (79.79%) and a-tecoferol (Vitamin E) (75.41%), these present a series of compounds such as methyl esters, hydrocarbons, triterpenoids, phytosterols, phenolic acids , fatty acids and linear chain fatty alcohols of chemical and biological interest. In the hexane extracts, the major compounds were identified as ß-sitosterol (87.46%), handianol (75.84%), dihydrochalisterol (49.73%), ß- sitosterol dihydrofucosterol (50.85%) and z, z-9,12-octadecadienoic acid (33.32%), methyl 9,12,15-octadecatrienoate (17.25%) and methyl 9,12-octadecadienoate (16.39% %). In the study carried out on acetone extract soluble in chloroform and the analysis performed on the fractions obtained by 13C and 1H NMR, there is a single compound in the whole fraction, globularin, a derivative of catalpol, formed by a iridoid and a glucose unit. Therefore, this is the first study on the characterization of hexane and acetone extract compounds for these genera. Thus, it is expected that the results of this research represent a step towards further studies on the biological activity of the chemical constituents present in the species under consideration.
Description
Keywords
Campylanthus Glaber Benth Ssp Glaber Compostos Bioativos Globularia Amygdalifolia Webb Medicina Tradicional Plantas Endémicas Produtos Naturais