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Avalia??o da capacidade antioxidante dos extratos etan?licos de plantas do cerrado: Ageratum fastigiatum (GARDN.) R. M. KING et H. ROB., Croton antisyphiliticus MART., Kielmeyera rubriflora CAMB., Miconia ferruginata DC. e Norantea adamantium CAMB.Lima, Philipe Dias de ?vila 20 July 2016 (has links)
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Previous issue date: 2016 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Funda??o de Amparo ? Pesquisa do Estado de Minas Gerais (FAPEMIG ) / Nos ?ltimos anos, um n?mero crescente de pesquisas tem demonstrado o papel chave das esp?cies reativas (ERs) na acelera??o do processo de envelhecimento e agravamento de doen?as inflamat?rias e cr?nico-degenerativas. Tais esp?cies, altamente reativas, podem oxidar v?rias biomol?culas e provocar graves les?es no organismo. O efeito das ERs ? equilibrado no organismo por a??o de antioxidantes enzim?ticos e n?o enzim?ticos, sendo estes ?ltimos, representados em sua maioria pelos compostos fen?licos, sendo os flavon?ides os principais representantes. Os flavon?ides podem ser consumidos na dieta di?ria atrav?s de v?rios alimentos como frutas, legumes, vinhos etc., por?m, o principal alvo para busca de tais compostos s?o as plantas medicinais que s?o constantemente utilizadas pela popula??o. Tendo em vista a import?ncia de desenvolvimento e busca de novos compostos antioxidantes naturais, o presente estudo teve como principal objetivo avaliar a atividade antioxidante dos extratos etan?licos de algumas esp?cies vegetais que v?m sendo utilizadas na medicina popular, dentre outras finalidades, como antiinflamat?rias, cicatrizantes e outros usos relacionados a atividade antioxidante. As esp?cies vegetais utilizadas foram: Ageratum fastigiatum (GARDN.) R. M. KING et H. ROB., Croton antisyphiliticus MART., Kielmeyera rubriflora CAMB., Miconia ferruginata DC., e Norantea adamantium CAMB., coletadas no munic?pio de Diamantina ? MG e regi?es subjacentes, ?reas de predomin?ncia do bioma Cerrado. Avaliando a atividade antioxidante e teor de fen?licos totais (FT) nos extratos, pode-se observar que todos os extratos, exceto da A. fastigiatum (partes a?reas) apresentaram altos teores de compostos fen?licos, determinado pelo m?todo colorim?trico de Folin-Ciocalteau (FC) e eficiente poder redutor (PR), com destaque para a N. adamantium (partes a?reas), que apresentou o maior teor de FT (684,59 mg EAG/g extrato) e o menor valor para o PR (EC50 = 66,77 ?g/mL). Quanto ? captura das esp?cies radicalares DPPH? e ABTS?+, os extratos seguiram uma correla??o positiva, determinada pelo coeficiente de Pearson, ou seja, os extratos com maiores teores de FT tamb?m apresentaram as melhores atividades de captura das esp?cies radicalares com destaque para a N. adamantium (partes a?reas) e C. antisyphiliticus (caule) que apresentaram resultados de EC50 estatisticamente semelhantes ao padr?o ?cido g?lico (AG) para a captura de ambas as esp?cies radicalares utilizadas. Para a captura dos reagentes HOCl e H2O2 todos os extratos foram eficientes, por?m apresentaram melhores resultados apenas em altas concentra??es (>100?g/mL), sendo necess?rio um estudo de citotoxicidade para avaliar se tais concentra??es n?o s?o t?xicas ?s c?lulas humanas. Por fim, foi realizada uma avalia??o de interfer?ncia dos extratos no burst oxidativo produzidos por neutr?filos humanos isolados ativados com PMA e todos os extratos apresentaram atividade protetora frente ?s esp?cies produzidas pelo burst oxidativo com destaque para C. antisyphiliticus (caule) e A. fastigiatum (partes a?reas) que apresentaram menores valores de EC50, igual a 8,51 e 5,74 ?g/mL respectivamente. / Disserta??o (Mestrado) ? Programa de P?s-gradua??o em Ci?ncias Farmac?uticas, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2016. / An increasing number of studies have been lately demonstrating the key role of the reactive species (RS) in accelerating aging and worsening inflammatory and chronic-degenerative diseases. This species, highly reactive, are able to oxidize several biomolecules and cause severe injuries to the organism. The effect of the RS is balanced by the enzymatic and non-enzymatic antioxidants, the latter being represented mostly by phenolic compounds and flavonoids key players which can be daily consumed in fruits, vegetables, wine etc. However, the main samples to search for these compounds are the medicinal plants extensively used by the population. Considering the importance of the development and screening of new natural antioxidant compounds, the present study aimed to evaluate the antioxidant activity of the ethanolic extracts of some species of plants that have been used in the popular medicine for its anti-inflammatory, healing and other uses related to antioxidant activity, among other features. The plants were: Ageratum fastigiatum (GARDN.); R. M. KING and H. ROB., Croton antisyphiliticus MART., Kielmeyera rubriflora CAMB., Miconia ferruginata DC., and Norantea adamantium CAMB., colleted at the municipality of Diamantina - MG and surroundings, where the biome Cerrado is predominant. The analysis of the antioxidant activity and the total phenolic content (TP) of the extracts showed that, except for the A. fastigiatum (aerial parts), all of the others presented high contents of phenolic compounds through the colorimetric assay of Folin-Ciocalteau (FC) and the effectiveness of the reductive power (RP). Highlights here to N. adamantium (aerial parts) extract which demonstrated the highest content of TP (684,59 mg EAG/g extract) and the lowest value of RP (EC50 = 66,77 ?g/mL). Regarding the capture of the following free radicals, DPPH? and ABTS?+, the extracts demonstrated a positive correlation, determined by the Pearson factor, which means that the extracts with the highest contents of TP also displayed better capture activities of those free radicals. It is important to emphasize N. adamantium (aerial parts) and C. antisyphiliticus (stem), once they presented statistically similar EC50 to the garlic acid (GA) for the capture of both of the free radicals used. For the capture of HOCl and H2O2, all the extracts showed to be efficient, nevertheless they presented better results only in high concentrations (>100?g/mL). Therefore it is relevant to perform a citotoxicity assay on human cells. At last, the interference of the extracts was evaluated on the oxidative burst produced by human neutrophils isolated and activated with PMA and all of them showed to be protective against the free radicals produced in the assay, in which C. antisyphiliticus (stem) and A. fastigiatum (aerial parts) standout for the lowest EC50, 8,51 and 5,74 ?g/mL respectively.
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Desenvolvimento de processos extrativos a partir da Rumex acetosa e caracteriza??o qu?mica de seus extratosSantos, ?nio Rafael de Medeiros 18 September 2017 (has links)
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Previous issue date: 2017-09-18 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / Pesquisas apresentam o excesso de radicais livres como um dos respons?veis por diversas doen?as degenerativas e pelo envelhecimento. Nesse contexto, desponta a utiliza??o de compostos fen?licos naturais por apresentarem ?tima atividade antioxidante e por inibirem a forma??o desses radicais. Em meio aos estudos acerca desses compostos, os antioxidantes: cis e trans-resveratrol, cis e trans-piceid e emodina ganham destaque no meio cient?fico. Trabalhos cient?ficos comprovam a presen?a desses compostos fen?licos na herb?cea ?Azedinha? (Rumex acetosa), logo, os extratos de suas ra?zes v?m sendo cada vez mais utilizadas em aplica??es farmacol?gicas. A partir disso, este trabalho teve por objetivo central a obten??o de extratos dessas ra?zes utilizando t?cnicas de extra??o com fluido supercr?tico (SFE), extra??o com l?quidos pressurizados (PLEs), extra??o com utiliza??o de micro-ondas (MAE), extra??o com solvente a baixa press?o (LPSE) e a extra??o Soxhlet. Na SFE, foi avaliado o efeito das vari?veis de processo (temperatura, vaz?o, press?o e concentra??o de cossolvente) sobre a cin?tica da extra??o, rendimento e solubilidade do extrato. Nas PLEs, tanto foram avaliadas a temperatura e a press?o, como a influ?ncia dos diferentes solventes (?gua, etanol, hexano, tolueno, acetonitrila e isopropanol) e seu uso sequenciado como PLE sequenciada. As curvas obtidas nas SFEs e PLEs foram ajustadas segundo os modelos: Mart?nez, Crank e Sovov? e seus desvios m?dios calculados. Na extra??o Soxhlet foi avaliado o uso de quatro solventes (etanol, acetonitrila, isopropanol e ?lcool terc-but?lico), enquanto que na extra??o LPSE e MAE foi utilizado o etanol como solvente. Tamb?m foi testada a utiliza??o da precipita??o por anti-solvente supercr?tico (SAS) como forma de secagem. O teor de fen?licos totais, a capacidade antioxidante dos extratos e os principais componentes do extrato foram determinados. Os rendimentos obtidos em todas as t?cnicas variaram de 0,2 a 8,7%, sendo o melhor resultado obtido na extra??o PLE com etanol. A SFE apresentou o extrato com maior concentra??o de emodina (42,8 mg/g). A concentra??o de trans-resveratrol em todos os extratos variou entre 1,0 e 5,7 mg/g, a depender da t?cnica utilizada. A atividade antioxidante e os compostos fen?licos totais resultaram em valores compreendidos entre 3,4 e 163,4 ?g/mL e 27,6 e 157,0 mg EAG/ge, respectivamente, a depender da t?cnica utilizada. A MAE obteve extratos com 130,6 mg EAG/ge, e 3,4 ?g/mL em 30 minutos de opera??o. As extra??es com fluidos pressurizados (PLEs e SFEs) demonstraram ?timos resultados, principalmente quanto ? extra??o sequencial, na qual foi poss?vel a separa??o de trans-resveratrol e emodina. / Research presents the excess of free radicals as one responsible for various degenerative diseases and aging. In this context, the use of natural phenolic compounds appears to have excellent antioxidant activity and to inhibit the formation of these radicals. In the middle of studies about these compounds, the antioxidants: cis and trans-resveratrol, cis and trans-piceid and emodin are prominent in the scientific world. Scientific works prove the presence of these phenolic compounds in the herbaceous "Azedinha" (Rumex acetosa), so extracts from their roots have been increasingly used in pharmacological applications. From this, the main objective of this work was to extract extracts of these roots using supercritical fluid extraction (SFE), pressurized fluid extraction (PLEs), microwave extraction (MAE), solvent extraction low pressure (LPSE) and Soxhlet extraction. In SFE, the effect of the process variables (temperature, flow, pressure and cosolvents concentration) on the kinetics of extraction, yield and solubility of the extract was evaluated. In the PLEs, both temperature and pressure and the influence of the different solvents (water, ethanol, hexane, toluene, acetonitrile and isopropanol) were evaluated and their use sequenced as PLE. The curves obtained in the SFEs and PLEs were adjusted according to the models: Mart?nez, Crank and Sovov? and their calculated mean deviations. In the Soxhlet extraction, the use of four solvents (ethanol, acetonitrile, isopropanol and tert-butyl alcohol) was evaluated, while in the LPSE and MAE extraction ethanol was used as the solvent. The use of supercritical anti-solvent (SAS) precipitation as a drying method was also tested. The total phenolic content, the antioxidant capacity of the extracts and the main components of the extract were determined. The yields obtained in all the techniques varied from 0.2 to 8.7%, being the best result obtained in the PLE extraction with ethanol. SFE presented the extract with the highest concentration of emodin (42.8 mg/g). The concentration of trans-resveratrol in all extracts ranged from 1.0 to 5.7 mg/g, depending on the technique used. The antioxidant activity and the total phenolic compounds resulted in values between 3.4 and 163.4 ?g/mL and 27.6 and 157.0 mg EAG/g, respectively, depending on the technique used. MAE obtained extracts with 130.6 mg EAG/g and 3.4 ?g/mL in 30 minutes of operation. Extractions with pressurized fluids (PLEs and SFEs) showed excellent results, mainly regarding sequential extraction, in which the separation of trans-resveratrol and emodin was possible.
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Metab?litos especiais isolados de folhas e galhos de Ouratea ferruginea Engl. (Ochnaceae).Fidelis, Queli Cristina 25 February 2011 (has links)
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Previous issue date: 2011-02-25 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico, CNPq, Brasil. / This work describes the phytochemical study of the stems and leaves of Ouratea
ferruginea Engl., Ochnaceae. The material for study was collected in the campus of Embrapa
in Bel?m, Par? state, and identified by Dra Silvane Taveres Rodrigues. The compounds
described in this phytochemistry investigation were isolated by the solvents partition and
chromatographyc techniques of the extracts obtained by maceration at room temperature with
hexane, ethyl acetate and methanol. The structures were determined through analysis of data
provided by IR, 1H and 13C NMR (1D an 2D techniques), mass spectrometry including GCMS
and HPLC-MS of natural compounds and some derivatives. From the stem
dichloromethane extract friedelin, friedelinol, sitosterol, stigmasterol, campesterol, 3-b-O-Dglucopyranosyl-
stigmasterol, 2,6-dimethoxy?benzoquinine, 2,6-dimethoxy-hydroquinone, the
isoflavones: 5,4'-dihydroxy-7,3',5'-trimethoxy-isoflavone, 5-hydroxy-7,3',4',5'-tetramethoxyisoflavone,
5,4'-dihydroxy-7,3'-dimethoxy-isoflavone, 7,5-dihydroxy-3',4',5'-trimethoxyisoflavone,
7,5,4?-trihydroxy-3?,5?-dimethoxy-isoflavone, and ferulic and syringic aldehyde
were isolated. From the dichloromethane partition of the methanol extract of the stem vanillic
acid, 4 ((1E)-3-hydroxy-1-propenyl)-2-methoxyphenol and 3,5-dimethoxy-4-hydroxydihydrocinamaldehyde
were isolated. From hexane fraction of methanol extract from the
leaves lupeone was isolated, and from the dichloromethane methanol partition were identified
the biflavonoids amentoflavone and 7-methyl-amentoflavone, known as sequoiaflavone,
along with syringic acid. From the ethyl acetate of the methanol extracts partition the
epicatechin which absolute configuration was defined by circular dichroism spectral analysis
was isolated. The sequioflanove is been identified in Ochnaceae for the first time. From the
polar fraction the total phenol were determined by adapted Folin-Denis and precipitation with
casein methods and by NMR spectral analysis. / Este trabalho descreve o estudo fitoqu?mico de caule e folhas da esp?cie vegetal
Ouratea ferruginea Engl, Ochnaceae. O material para estudo foi coletado no campus da
Embrapa em Bel?m do Par? e identificado pela Dra Silvane Tavares Rodrigues. As
subst?ncias descritas nesta investiga??o fitoqu?mica foram isoladas atrav?s de parti??o com
solventes e t?cnicas cromatogr?ficos de extratos obtidos atrav?s de macera??o a frio com
hexano, acetato de etila e metanol. As estruturas foram determinadas atrav?s da an?lise de
dados fornecidos por espectrometria na regi?o do infravermelho, RMN 1H e 13C (t?cnicas 1D
e 2D), de massas incluindo CG-EM e CLAE-EM das subst?ncias naturais e de alguns
derivados. Do extrato em diclorometano do caule foram isolados friedelina, friedelinol,
sitosterol, estigmasterol, campesterol, 3-b-O-D-glicopiranosil-estigmasterol, 2,6-dimetoxi
benzoquinona, 2,6-dimetoxi hidroquinona, as isoflavonas 5,4?-diidroxi-7,3?,5?-trimetoxiisoflavona,
5,4?-diidroxi-7,3?-dimetoxi-isoflavona, 5-hidroxi-7,3?,4?,5?-tetrametoxiisoflavona,
7,5-diidroxi-3?,4?,5?-trimetoxi-isoflavona, 7,5,4?-triidroxi-3?,5?-dimetoxiisoflavona,
al?m dos alde?dos sir?ngico e fer?lico. Da parti??o em diclorometano do extrato
metan?lico do caule foram isolados ?cido van?lico, 4((1E)-3-hidroxi-1-propenil)-2-
metoxifenol e 3,5-dimetoxi-4-hidroxi-diidrocinamalde?do. Das folhas foi isolada a lupeona na
parti??o em hexano do extrato metan?lico; e na parti??o em diclorometano foram
identificados os biflavon?ides amentoflavona e 7-metil-amentoflavona, conhecida como
sequoiaflavona, e o ?cido sir?ngico. Na parti??o em acetato de etila foi isolado a epicatequina
cuja configura??o absoluta foi definida com an?lise do espectro de dicro?smo circular. A
sequioflavona est? sendo registrada pela primeira vez em Ochnaceae. Das fra??es polares
foram determinados o teor de fen?is totais e taninos por m?todos de Folin-Denis e
precipita??o com case?na, adaptados, al?m de an?lise com espectros de RMN.
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Estrat?gias de obten??o do corante do jambo vermelho (Syzygium malaccense) e avalia??o de sua funcionalidadeAzev?do, Juliana Chris Silva de 17 December 2010 (has links)
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Previous issue date: 2010-12-17 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The food industry is interested in natural products. Anthocyanins are phenolic antioxidants of
great importance with health-relevant applications. Several studies have linked the intake of
fruits and vegetables with reduced risk of chronic degenerative diseases because of its
antioxidant properties. This study aimed to compare different strategies for obtaining natural
pigments from red jambo (Syzygium malaccence) and analyze its functional potential. Two
different strategies were studied: (1) solid-liquid extraction (SLE) in reactor with controlled
parameters, (2) powder obtention. The investigation of the functional potential was conducted
taking into account the total phenolic content (TPC), the antioxidant activity (AA), the total
anthocyanins concentration (TA) and α-amylase and α-glucosidase inhibition. The best
extracts obtained by SLE showed TPC of 174.15 mg GAE/100g, AA of 3.56 μmol Trolox
eq/g and TA of 133.59 mg cyd-3-glu/100 g. The best results for the second strategy were TPC
of 1024.22 mg GAE/100 g, AA of 29.03 μmol Trolox eq/g and TA of 1193.41 mg cyd-3-
glu/100 g. It was observed moderate amylase inhibition (26.30%) and high glucosidase
inhibitory activity (97.47%). Skin extracts showed, in general, superior results when
compared to whole red jambo, with superior values for dehydrated products. Based on our
result, red jambo can be considered as a rich source of phenolic antioxidants, as well on
amylase and glucosidase inhibitors / A ind?stria aliment?cia demonstra forte interesse em estudos de extra??o
envolvendo produtos naturais. A antocianina ? um fen?lico antioxidante de grande
import?ncia e atua??o no organismo dos seres vivos. V?rios estudos relacionam ? ingest?o de
frutas e vegetais com a diminui??o do risco e desenvolvimento de doen?as cr?nicodegenerativas
em fun??o de suas propriedades antioxidantes. Este trabalho teve como objetivo
comparar diferentes estrat?gias de obten??o do corante da casca e do jambo inteiro sem
caro?o e analisar seu potencial funcional. Duas diferentes estrat?gias foram estudadas: (1)
extra??o s?lido-l?quido em reator enjaquetado com controle de par?metros; (2) obten??o do
p?. A investiga??o do potencial funcional foi realizada por meio de an?lises quanto ao teor de
compostos fen?licos totais (CFT), a atividade antioxidante (AA), a concentra??o de
antocianinas totais (AT) e a inibi??o das enzimas α-amilase e α-glicosidase. Os extratos com
os melhores resultados para a estrat?gia 1 foram para CFT de 174,15 mg GAE/100 g, para a
AA de 3,56 μmol Trolox eq/g e para AT de 133,59 mg ci-3-gli/100 g. Os melhores valores
para a estrat?gia 2 foram para CFT de 1024,22 mg GAE/100 g, para AA de 29,03 μmol
Trolox eq/g e para AT de 1193,41 mg ci-3-gli/100 g. A a??o inibit?ria das enzimas α-amilase
(26,30%) e α-glicosidase (97,47%) mostraram-se potentes. Os extratos da casca apresentaram,
de maneira geral, resultados superiores quando comparados aos valores dos extratos do jambo
inteiro e as maiores quantifica??es foram obtidas dos produtos desidratados. As amostras
analisadas exibiram fontes satisfat?rias de fen?licos antoci?nicos, com potente capacidade
antioxidante e atividade inibit?ria das enzimas α-amilase e α-glicosidase
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Extra??o, caracteriza??o e avalia??o bioativa do extrato de Rumex acetosaSantos, ?nio Rafael de Medeiros 08 August 2013 (has links)
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Previous issue date: 2013-08-08 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Studies show the great influence of free radicals and other oxidants as responsible for aging
and degenerative diseases. On the other hand, the natural phenolic compounds has shown
great as antioxidants to inhibit lipid peroxidation and lipoxygenase in vitro. Among these, is
highlighted trans-resveratrol ( 3,5,4 `- trihydroxystilbene ) phenolic compound , characterized
as a polyphenol stilbene class. The vegetables popularly known as "Azedinha" (Rumex
Acetosa) has trans-resveratrol in its composition and from this, the present work aimed to
study on the supercritical extraction and conventional extraction (Soxhlet and sequential) in
roots of Rumex Acetosa, evaluating the efficiency of extractive processes, antioxidant activity,
total phenolic content and quantification of trans-resveratrol contained in the extracts.
Extractions using supercritical CO2 as solvent, addition of co-solvent (ethanol) and were
conducted by the dynamic method in a fixed bed extractor. The trial met a 23 factorial design
with three replications at the central point, with the variable reply process yield and
concentration of trans-resveratrol and pressure as independent variables, temperature and
concentration of co-solvent (% v/v). Yields ( mass of dry extract / mass of raw material used )
obtained from the supercritical extraction ranged from 0,8 to 7,63 % , and the best result was
obtained at 250 bar and 90 ?C using the co-solvent 15% ethanol (% v/v). The value was
calculated for YCER a flow rate of 1,0 ? 0,17 g/min resulting in 0,0469 CO2 ( g solute / g
solvent ). The results of the mass yield varied between conventional extractions 0,78 % (
hexane) and 9,97 % (ethanol). The statistical model generated from the data of the
concentration of trans-resveratrol performed as meaningful and predictive for a 95%
confidence. GC analysis on HPLC (High Performance Liquid Chromatography), transresveratrol
was quantified in all extracts and concentration values ranged between 0,0033 and
0,42 ( mg / g extract) for supercritical extracts and between 0,449 and 17,046 (mg / g extract)
to conventional extractions and therefore, the Soxhlet extraction with ethanol for more
selective trans-resveratrol than the supercritical fluid. Evaluation of antioxidant (radical
method to sequester 2,2- diphenyl-1- picryl - hydrazyl - DPPH) the supercritical extracts
resulted in EC50 values (concentration effective to neutralize 50% of free radicals) of between
7,89 and 18,43 mg/mL , while resulting in a Soxhlet extraction with EC50 values in the range
of 6,05 and 7,39 mg/mL. As for quantification of the phenolic compounds (Method
Spectrophotometer Folin-Ciocalteau) the supercritical extracts resulted in values between 85,3
and 194,79 mg GAE / g extract, whereas values derived from the Soxhlet extract resulted in values between 178,5 and 237,8 mg GAE / g extract. The high antioxidant activity can not be
attributed solely to the presence of phenolic compounds, but the presence of other
antioxidants in the existing Rumex acetosa / Estudos revelam a grande influ?ncia dos radicais livres e outros oxidantes como
respons?veis pelo envelhecimento e por doen?as degenerativas. Por outro lado, os compostos
fen?licos naturais tem-se apresentado como ?timos antioxidantes por inibirem a peroxida??o
lip?dica e a lipooxigenase in vitro. Dentre estes, encontra-se em destaque o trans-resveratrol
(3,5,4 trihidroxiestilbeno), composto fen?lico, caracterizado como um polifenol da classe
estilbeno. A hortali?a popularmente conhecida como Azedinha (Rumex acetosa) possui o
trans-resveratrol em sua composi??o e a partir disto, o presente trabalho teve como objetivo
geral o estudo sobre a extra??o supercr?tica e a extra??o convencional (Soxhlet e sequencial)
em ra?zes da Rumex acetosa, avaliando-se a efici?ncia dos processos extrativos, a atividade
antioxidante, o teor de fen?licos totais e a quantifica??o do trans-resveratrol contido nos
extratos. As extra??es supercr?ticas utilizaram CO2 como solvente, adicionado de co-solvente
(etanol) e foram conduzidas pelo m?todo din?mico em um extrator de leito fixo. Os ensaios
obedeceram a um planejamento fatorial 23 com triplicata no ponto central, tendo como
vari?vel resposta o rendimento do processo e a concentra??o de trans-resveratrol e como
vari?veis independentes a press?o, a temperatura e a concentra??o de co-solvente (% v/v). Os
rendimentos (massa de extrato seco/ massa de mat?ria-prima utilizada) obtidos da extra??o
supercr?tica variaram de 0,8 a 7,63%, sendo que o melhor resultado foi obtido a 250 bar e
90?C, com uso do co-solvente etanol a 15% (v/v). O valor de YCER foi calculado para uma
vaz?o de 1,0 ? 0,17 g/min de CO2 resultando em 0,0469 (g soluto/ g solvente). Os resultados
de rendimento em massa para as extra??es convencionais variaram entre 0,78% (hexano) e
9,97% (etanol). O modelo estat?stico gerado a partir dos dados de concentra??o de transresveratrol
se apresentou como significativo e preditivo para uma confian?a de 95%. Atrav?s
de an?lises cromatogr?ficas em CLAE (Cromatografia L?quida de Alta Efici?ncia), o transresveratrol
foi quantificado em todos os extratos obtidos e os valores de concentra??o
variaram entre 0,0033 e 0,42 (mg/g extrato) para os extratos supercr?ticos e entre 0,449 e
17,046 (mg/g extrato) para extra??es convencionais, sendo, portanto, a extra??o Soxhlet com
etanol mais seletiva em trans-resveratrol que a supercr?tica. A avalia??o do poder antioxidante
Extra??o, caracteriza??o e avalia??o bioativa do extrato de Rumex acetosa
iii
?nio Rafael de Medeiros Santos, Agosto de 2013
(m?todo do sequestro do radical 2,2-difenil-1-picril-hidrazil-DPPH) dos extratos supercr?ticos
resultaram em valores de EC50 (Concentra??o efetiva que neutraliza 50% dos radicais livres)
compreendidos entre 7,89 e 18,43 μg/mL, enquanto que as extra??es com Soxhlet resultaram
em valores de EC50 na faixa de 6,05 e 7,39 μg/mL. J? a quantifica??o dos compostos fen?licos
totais (M?todo espectrofot?metro de Folin-Ciocalteau) dos extratos supercr?ticos resultaram
em valores compreendidos entre 85,3 e 194,79 mg EAG/g extrato, enquanto que os valores
dos extratos oriundos do Soxhlet resultaram em valores compreendidos entre 178,5 e 237,8
mg EAG/g extrato. A alta atividade antioxidante pode ser atribu?da n?o somente ? presen?a de
compostos fen?licos, mas tamb?m ? presen?a de outros antioxidantes existentes na Rumex
acetosa
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