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Previous issue date: 2015-06-15 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico - CNPq / A utiliza??o de plantas com finalidades medicinais ? milenar, sendo bastante
difundida sua aplica??o em medicamentos. Apesar das plantas serem fontes promissoras para
a descoberta de novas mol?culas de interesse farmacol?gico, estimativas revelam que apenas
17% delas foram estudadas quanto a sua possibilidade de uso na medicina. Assim, a
biodiversidade da flora brasileira representa um imenso potencial de utiliza??o econ?mica
pela ind?stria farmac?utica. A planta Arrabidaea chica, popularmente conhecida como
?pariri?, ? comum na regi?o Amaz?nica, e a ela s?o atribu?das v?rias propriedades medicinais.
As folhas desta planta s?o ricas em antocianinas, que s?o compostos fen?licos com alto poder
antioxidante. Os compostos antioxidantes desempenham um papel vital na preven??o de
doen?as neurol?gicas e cardiovasculares, c?ncer e diabetes, entre outras. Dentre as
antocianinas encontradas na Arrabidaea chica, destaca-se a Carajurina (6,7-dihidroxi-5,4?-
dimetoxi-flavilium), que ? o principal pigmento encontrado nesta planta. O presente trabalho
teve como objetivo geral o estudo sobre a extra??o supercr?tica e a extra??o convencional
(s?lido-l?quido) de folhas da Arrabidaea chica, avaliando-se o rendimento dos processos
extrativos, a atividade antioxidante e a quantifica??o de Carajurina contida nos extratos. As
extra??es supercr?ticas utilizaram CO2 como solvente, adicionado de co-solvente (mistura
etanol/?gua), e foram conduzidas pelo m?todo din?mico em um extrator de leito fixo. Os
ensaios obedeceram a um planejamento fatorial fracion?rio 24-1, tendo como vari?veis
resposta o rendimento do processo, o poder antioxidante e a concentra??o de Carajurina, e
como vari?veis independentes a press?o, a temperatura, a concentra??o de co-solvente (v/v) e
a concentra??o de ?gua no co-solvente (v/v). Os rendimentos (massa de extrato seco/massa de
mat?ria-prima utilizada) obtidos da extra??o supercr?tica variaram de 15,1% a 32%, sendo que
o melhor resultado foi obtido a 250 bar e 40?C, com uso do co-solvente a 30% (v/v) e
concentra??o de ?gua no co-solvente igual a 50% (v/v). Atrav?s de an?lise estat?stica,
verificou-se que a concentra??o de co-solvente apresentou efeito significativo sobre o
rendimento. Os resultados de rendimento em massa para as extra??es convencionais foram de
8,1% (?gua) e 5,5% (etanol). Atrav?s de an?lises cromatogr?ficas em CLAE (Cromatografia L?quida de Alta Efici?ncia), a Carajurina foi quantificada em todos os extratos obtidos e os
valores de concentra??o (massa de Carajurina/massa de extrato seco) variaram entre 1% e
2,21% para os extratos supercr?ticos. Quanto ?s extra??es convencionais, n?o foi detectada
Carajurina no extrato aquoso, enquanto o extrato etan?lico apresentou teor de Carajurina igual
a 7,04%, sendo, portanto, mais seletivo em Carajurina do que as extra??es supercr?ticas. A
avalia??o do poder antioxidante (m?todo do sequestro do radical 2,2-difenil-1-picril-hidrazilDPPH)
dos extratos supercr?ticos resultou em valores de EC50 (concentra??o efetiva que
neutraliza 50% dos radicais livres) compreendidos entre 38,34 e 86,13 ?g/mL, enquanto que
as extra??es convencionais resultaram em valores de EC50 de 167,34 (?gua) e 42,58 (etanol)
?g/mL. J? a quantifica??o dos compostos fen?licos (m?todo espectrofotom?trico de FolinCiocalteau)
dos extratos supercr?ticos resultou em valores compreendidos entre 48,93 e 88,62
mg EAG/g extrato (EAG = Equivalentes de ?cido G?lico), enquanto que as extra??es s?lidol?quido
resultaram em valores de 37,63 (?gua) e 80,54 (etanol) mg EAG/g extrato. A boa
atividade antioxidante pode ser atribu?da n?o somente ? presen?a de Carajurina, mas tamb?m
? exist?ncia de outros compostos fen?licos e antioxidantes na Arrabidaea chica. Atrav?s da
otimiza??o do planejamento experimental, foi poss?vel identificar o experimento que
apresentou o melhor resultado considerando as quatro vari?veis resposta em conjunto. Este
experimento foi realizado nas seguintes condi??es: press?o de 200 bar, temperatura de 40?C,
concentra??o de co-solvente igual a 30% (v/v) e concentra??o de ?gua no co-solvente igual a
30% (v/v). Conclui-se que, dentro da faixa estudada, ? poss?vel obter o resultado ?timo
utilizando condi??es operacionais mais amenas, o que implica em menores custos e maior
facilidade de opera??o. / The use of plants for medicinal purposes is ancient, with widespread application in medicinal
drugs. Although plants are promising sources for the discovery of new molecules of
pharmacological interest, estimates show that only 17% of them have been studied for their
possible use in medicine. Thus, biodiversity of Brazilian flora represents an immense
potential for economic use by the pharmaceutical industry. The plant Arrabidaea chica,
popularly known as ?pariri?, is common in the Amazon region, and it is assigned several
medicinal properties. The leaves of this plant are rich in anthocyanins, which are phenolic
compounds with high antioxidant power. Antioxidant compounds play a vital role in the
prevention of neurological and cardiovascular diseases, cancer and diabetes, among others.
Within the anthocyanins found in Arrabidaea chica, stands out Carajurin (6,7-dihydroxy-5,4?-
dimethoxy-flavilium), which is the major pigment encountered in this plant. The present work
aimed to study on supercritical extraction and conventional extraction (solid-liquid extraction)
in leaves of Arrabidaea chica, evaluating the efficiency of the extractive processes,
antioxidant activity and quantification of Carajurin contained in the extracts. Supercritical
extraction used CO2 as solvent with addition of co-solvent (ethanol/water mixture) and were
conducted by the dynamic method in a fixed bed extractor. The trials followed a 24-1
fractional factorial design, the dependent variables were: process yield, concentration of
Carajurin and antioxidant activity; and independent variables were: pressure, temperature,
concentration of co-solvent (v/v) and concentration of water in the co-solvent mixture (v/v).
Yields (mass of dry extract/mass of raw material used) obtained from supercritical extraction
ranged from 15.1% to 32%, and the best result was obtained at 250 bar and 40 ?C, co-solvent
concentration equal to 30% and concentration of water in the co-solvent mixture equal to
50%. Through statistical analysis, it was found that the concentration of co-solvent revealed
significant effect on the yield. Yields obtained from conventional extractions were of 8.1%
(water) and 5.5% (ethanol). Through HPLC (High-performance liquid chromatography)
analysis, Carajurin was quantified in all the extracts and concentration values (Carajurin
mass/mass of dry extract) ranged between 1% and 2.21% for supercritical extraction. For
conventional extraction, Carajurin was not detected in the aqueous extract, while the ethanol
extract showed Carajurin content of 7.04%, and therefore, more selective in Carajurin than the
supercritical extraction. Evaluation of antioxidant power (radical 2,2-diphenyl-1-picrylhydrazyl
? DPPH ? sequestration method) of the supercritical extracts resulted in EC50 values
(effective concentration which neutralizes 50% of free radicals) ranged from 38.34 to 86.13 ?g/mL, while conventional extraction resulted in EC50 values of 167.34 (water) and 42.58
(ethanol) ?g/mL. As for the quantification of total phenolic content (Folin-Ciocalteau
analysis) of the supercritical extracts resulted in values ranged from 48.93 and 88.62 mg
GAE/g extract (GAE = Gallic Acid Equivalents), while solid-liquid extraction resulted in
values of 37.63 (water) and 80.54 (ethanol) mg GAE/g extract. The good antioxidant activity
cannot be attributed solely to the presence of Carajurin, but also the existence of other
compounds and antioxidants in Arrabidaea chica. By optimizing the experimental design, it
was possible to identify the experiment that presented the best result considering the four
dependent variables together. This experiment was performed under the following conditions:
pressure of 200 bar, temperature of 40 ?C, co-solvent concentration equal to 30% and
concentration of water in the co-solvent mixture equal to 30%. It is concluded that, within the
studied range, it is possible to purchase the optimum result using milder operating conditions,
which implies lower costs and greater ease of operation.
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/20164 |
| Date | 15 June 2015 |
| Creators | Santos, Rog?rio Pitanga |
| Contributors | 29171156453, http://lattes.cnpq.br/0263455300382979, Galv?o, Elis?ngela Lopes, 03247032444, http://lattes.cnpq.br/4522095618671600, Oliveira, Humberto Neves Maia de, 22179763468, http://lattes.cnpq.br/7302633941782540, Sousa, Elisa Maria Bittencourt Dutra de |
| Publisher | Universidade Federal do Rio Grande do Norte, PROGRAMA DE P?S-GRADUA??O EM ENGENHARIA QU?MICA, UFRN, Brasil |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Source | reponame:Repositório Institucional da UFRN, instname:Universidade Federal do Rio Grande do Norte, instacron:UFRN |
| Rights | info:eu-repo/semantics/openAccess |
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