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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

The phytochemistry and biological activities of Athrixia Phylicoides

Padayachee, Kumeshnie 27 October 2011 (has links)
Herbal medicines are an important part of the African culture and tradition and about 80% of Africa’s population relies on traditional remedies for their primary health care needs (WHO, 2008). Athrixia phylicoides is widely used as a traditional remedy, but despite its substantial use, literature on its chemical composition and biological activities is limited. In this study, the chemical composition of the essential oil was determined using gas chromatography combined with mass spectroscopy (GC/MS) and analysis resulted in the identification of 182 compounds. The major compounds identified in selected samples were α-pinene, β-pinene, caryophyllene oxide, β-caryophyllene, myrcene and spathulenol. Based on the traditional uses of A. phylicoides, various in vitro biological activities were investigated. The extensive use of A. phylicoides for the treatment of boils, sores, bad acne, infected wounds and cuts, prompted the antimicrobial (bacterial and fungal) study using the minimum inhibitory concentration (MIC) assay. The methanol extract and essential oil were more selective for the Grampositive bacteria than the Gram-negative bacteria. The extract exhibited stronger activity against all micro-organisms tested compared to the essential oil, with the highest activity against S. aureus, B. cereus and B. subtilis (MIC = 1 mg/ml). The bioactive compound, (4-hydroxyphenyl) propyl coumaroate was isolated from the extract and proved to be most active against S. aureus (MIC = 19.5 μg/ml). Using the DPPH• assay, a comparative antioxidant study was performed. The anti-oxidant activity of the aqueous extract of A. phylicoides (IC50 = 14.01 ± 2.68 μg/ml) was greater than rooibos and Ceylon (black) tea (IC50 > 25.00 μg/ml); comparable to green rooibos and honeybush tea (IC50 = 18.01 ± 4.06 μg/ml; 18.02 ± 4.27 μg/ml, respectively), but less active than green tea (IC50 = 9.64 ± 0.96 μg/ml). The antimalarial activity was determined using the [3H] hypoxanthine incorporation method. The essential oil exhibited greater antimalarial activity against the chloroquine-resistant Plasmodium falciparum (FCR-3) strain (IC50 = 1.006 ± 0.06 μg/ml) than the methanol extract. The 5-lipoxygenase assay was used to assess the anti-inflammatory activity of the methanol extract and essential oil. Only the essential oil displayed anti-inflammatory activity (IC50 = 25.68 μg/ml). Low safety indices were reported for both the methanol extract (SI = 2.28) and essential oil (SI = 1.77). The in vitro biological activities may validate the use of A. phylicoides in traditional medicine.
2

AVALIAÇÃO DAS ATIVIDADES ANGIOGÊNICA E ANTIMICROBIANA DO ÓLEO ESSENCIAL DA CURCUMA LONGA.

Araújo, Rafael Gonçalves Machado de 22 March 2013 (has links)
Made available in DSpace on 2016-08-10T10:54:05Z (GMT). No. of bitstreams: 1 RAFAEL GONCALVES MACHADO DE ARAUJO.pdf: 2062014 bytes, checksum: 3fb7a205a18988c46ae096101247fb2e (MD5) Previous issue date: 2013-03-22 / Neste trabalho foram avaliadas as atividades angiogênica e antimicrobiana do óleo essencial da Curcuma longa (açafrão). O óleo essencial foi extraído pelo método da hidrodestilação por arraste a vapor, a partir do pó dos rizomas do açafrão. A atividade angiogênica foi avaliada pelo método experimental da membrana corioalantóide, e o tratamento estatístico realizou-se por meio da análise de variância (Kruskal-Wallis) e por comparação múltipla (método de Dunn) do grupo teste com os grupos dos controles, considerando o nível de significância de p<0,05. A atividade antimicrobiana do óleo essencial foi avaliada para bactérias gram negativa Escherichia coli e gram positiva Staphylococcus simulans. No teste realizado com a membrana corioalantóide, o óleo essencial do açafrão produziu aumento da rede vascular superior ao controle negativo e inibidor (p<0,05), não apresentou diferença estatística quanto comparada ao controle indutor (p>0,05). A avaliação da atividade antimicrobiana demonstrou que não houve formação do halo de inibição para o óleo essencial do açafrão.
3

Obtenção de derivados químicos de produtos naturais empregando catálise convencional e enzimática

Silva, Maria de Lourdes e January 2012 (has links)
202 f. / Submitted by Ana Hilda Fonseca (anahilda@ufba.br) on 2013-03-27T15:07:41Z No. of bitstreams: 1 Tese Maria de Lourdes Completa.pdf: 1276547 bytes, checksum: ab45e41c0f73a5e85be2b1a246cbdb9e (MD5) / Approved for entry into archive by Ana Hilda Fonseca(anahilda@ufba.br) on 2013-06-05T16:01:37Z (GMT) No. of bitstreams: 1 Tese Maria de Lourdes Completa.pdf: 1276547 bytes, checksum: ab45e41c0f73a5e85be2b1a246cbdb9e (MD5) / Made available in DSpace on 2013-06-05T16:01:37Z (GMT). No. of bitstreams: 1 Tese Maria de Lourdes Completa.pdf: 1276547 bytes, checksum: ab45e41c0f73a5e85be2b1a246cbdb9e (MD5) Previous issue date: 2012 / Os triterpenos são extensamente distribuídos na natureza, principalmente no reino vegetal, pois se acredita que uma de suas funções fisiológicas nos vegetais seja de defesa química contra patógenos e herbívora. Podem ser encontrados na forma livre, como glicosídeos ou ainda derivados esterificados. Os ácidos oleanólico, betulínico e ursólico são os triterpenos ácidos mais comuns de ocorrência em vegetais e, possuem atividades antitumorais conhecidas. Este trabalho descreve um levantamento da ocorrência dessas substâncias e obtenção de derivados a partir deles e de ácidos graxos comuns. Os ácidos betulínico, ursólico e oleanólico, isolados das partes aéreas de Eriope blanchetii (Lamiaceae), foram submetidos a diferentes reações de esterificação obtendo-se assim 12 derivados esterificados na posição C-3. Tanto as substâncias isoladas quanto os derivados triterpênicos foram caracterizados por técnicas espectroscópicas no IV, RMN de 1H e 13C. Os derivados foram submetidos a testes de atividade antioxidante, letalidade frente Artemia salina e atividade antimicrobiana. Além disso, o ácido o-metoxicinâmico e ácido oleico foram submetidos a esterificação com etanol e metanol empregando-se Novoenzyme, comparando-se o rendimento do produto da reação a temperatura ambiente e sob irradiação de microondas / Salvador
4

Métabolites secondaires de champignons de sédiments marins profonds : criblages génétique et fonctionnel et caractérisation structurale de molécules antimicrobiennes / Secondary metabolites from deep subseafloor fungi : genetic and functional screenings, and antimicrobial molecules characterization

Navarri, Marion 16 December 2016 (has links)
La propagation des micro-organismes résistants aux antibiotiques menace le système mondial de santé publique. Pour lutter contre ce phénomène, le renouvellement des molécules utilisées en antibiothérapie est devenu une priorité mondiale. Les antibiotiques étant principalement d’origine microbienne, l’étude des micro-organismes et de leurs métabolites s’est donc renforcée et s’oriente vers des écosystèmes peu explorés comme les biotopes marins.Nous avons exploré les activités antimicrobiennes d’une collection de 183 champignons isoles de sédiments marins profonds et collectés entre 4 et 1884 mètres sous le plancher océanique. Le potentiel de production de métabolites de cette collection a été révélé par un criblage génétique ciblant les PolyKetide synthase (PKS), les Non-Ribosomal Peptide Synthetase (NPRS), les TerPene Synthase (TPS) et les hybrides PKS-NRPS. Après avoir regroupé les isolats en fonction de leur profil MSP PCR, 110 ont été sélectionnés pour un criblage fonctionnel, montrant une forte proportion de champignons filamenteux antimicrobiens (32%).Après extraction et fractionnement, les composés bioactifs de 3 souches ont été caractérisés aux niveaux structural et fonctionnel. Ainsi, O. griseum UBOCC-A-114129 produit la fuscine, la dihydrofuscine, la secofuscine et la dihydrosecofuscine, P. bialowiezense UBOCC-A-114097 produit l’acide mycophénolique et Penicillium sp. produit UBOCC-A-114109 la rugulosine.Parallèlement, des analyses en LC-HRMS, réalisées sur des extraits fongiques, ont révélé un grand nombre de métabolites non décrits dans les bases de données. Les champignons des sédiments marins constituent donc un réservoir de structures originales à explorer. / The spreading of antimicrobial resistant microorganisms jeopardizes global health caresystem. To counteract this threat the renewal of antibiotic molecules is a global priority. Antibioticcompounds are mainly originated from microorganisms, so microorganisms and their secondarymetabolites received an increasing interest. The search for new natural antimicrobial compoundsfrom microorganisms gained untapped ecosystems as marine biosphere.We investigated the antimicrobial properties of a fungal collection. The 183 fungal isolateswere collected from deep subseafloor sediment and isolated between 4 and 1,884 meters belowthe seafloor. Secondary metabolites production potential was studied for all isolates in thecollection by screening genes coding PolyKetide Synthase (PKS), Non-Ribosomal Peptide Synthetase(NRPS), TerPene Synthase (TPS) and hybrid PKS-NRPS. After isolates dereplication according to theirMSP-PCR fingerprinting, an antimicrobial screening was performed for 110 isolates, highlighting ahigh proportion of filamentous fungi with antimicrobial properties (32%).After extraction and bio-guided fractionation bioactive metabolites isolated from 3 strains,were characterized in a structural and functional manner: O. griseum UBOCC-A-114129 producedfuscin, dihydrofuscin, secofuscin and dihydrosecofuscine, P. bialowiezense UBOCC-A-114097synthetized mycophenolic acid and Penicillium sp. UBOCC-A-114109 produced rugulosin.In the meantime, LC-HRMS analysis, performed on fungal extracts, showed a great proportionof metabolites not detected in interrogated databases. So, deep subseafloor fungi, represent anuntapped reservoir of original structures to explore.
5

Molecular characterization of Aeromonas hydrophila and antimicrobial activities of selected medicinal plants against pathogenic isolates from water and stool samples in the era of HIV/AIDS in Limpopo Province, South Africa

Ramalivhana, Naledzani Jeoffry 05 1900 (has links)
Aeromonas hydrophila is distributed widely in nature and is responsible for an array of human infections. Several studies on the isolation and characterisation of the organism abound. Although there are reports on the antibiotic resistance profiles of the organism, these reports have not been updated in Limpopo province, South Africa despite the established fact that antibiograms vary with time and geographical area. Antibiotic resistance and pathogenesis of an organism are dependent on a host of factors such as the production of extended spectrum beta-lactamases and the genetic profiles such as the genes coding for resistance and possession of integrons and how these characteristics overach with the phylogenetic inter-relatedness of isolates from different sources. In spite of the aforementioned concerns on the efficacy of antibiotics due to the acquisition or endowment of microorganisms with intrinsic and extrinsic factors , which enhances resistance to antibiotics , medicinal plants are reportedly offering promise as alternative sources of efficacious management of infections. Medicinal plants are employed by traditional healers in the management of infections in developing countries especially in Africa. However, the antimicrobial activities of medicinal plants against Aeromonas hydrophila have received only a cursory attention. In an endeavour to undertake a comprehensive study on the isolation, characterisation, antibiograms, activities of medicinal plants as well as the genetic profiles, including phylogenetics relatedness of Aeromonas isolates from different sources, stool and water samples were collected over a two year period from designated places in Limpopo Province and analysed using standard techniques applicable to the constituent research activity. The research findings are presented in six chapters as presented hereunder. The first chapter focussed on the literature review of the organism and reflects areas such as the morphology, laboratory diagnosis, clinical manifestations, pathogenesis, antimicrobial susceptibility profiles, antibacterial activities of medicinal plants as well as the genetic aspects of Aeromonas hydrophila. / Environmental Science / D.Phil. (Environmental Science)
6

Molecular characterization of Aeromonas hydrophila and antimicrobial activities of selected medicinal plants against pathogenic isolates from water and stool samples in the era of HIV/AIDS in Limpopo Province, South Africa

Ramalivhana, Naledzani Jeoffry 05 1900 (has links)
Aeromonas hydrophila is distributed widely in nature and is responsible for an array of human infections. Several studies on the isolation and characterisation of the organism abound. Although there are reports on the antibiotic resistance profiles of the organism, these reports have not been updated in Limpopo province, South Africa despite the established fact that antibiograms vary with time and geographical area. Antibiotic resistance and pathogenesis of an organism are dependent on a host of factors such as the production of extended spectrum beta-lactamases and the genetic profiles such as the genes coding for resistance and possession of integrons and how these characteristics overach with the phylogenetic inter-relatedness of isolates from different sources. In spite of the aforementioned concerns on the efficacy of antibiotics due to the acquisition or endowment of microorganisms with intrinsic and extrinsic factors , which enhances resistance to antibiotics , medicinal plants are reportedly offering promise as alternative sources of efficacious management of infections. Medicinal plants are employed by traditional healers in the management of infections in developing countries especially in Africa. However, the antimicrobial activities of medicinal plants against Aeromonas hydrophila have received only a cursory attention. In an endeavour to undertake a comprehensive study on the isolation, characterisation, antibiograms, activities of medicinal plants as well as the genetic profiles, including phylogenetics relatedness of Aeromonas isolates from different sources, stool and water samples were collected over a two year period from designated places in Limpopo Province and analysed using standard techniques applicable to the constituent research activity. The research findings are presented in six chapters as presented hereunder. The first chapter focussed on the literature review of the organism and reflects areas such as the morphology, laboratory diagnosis, clinical manifestations, pathogenesis, antimicrobial susceptibility profiles, antibacterial activities of medicinal plants as well as the genetic aspects of Aeromonas hydrophila. / Environmental Science / D.Phil. (Environmental Science)
7

Estudo fitoquímico e biológico de espécies amazônicas: Pradosia huberi (Ducke) Ducke (Sapotaceae) e Licania macrophylla Bent. (Chrysobalanaceae)

Medeiros, Fernando Antônio de 18 December 2008 (has links)
Made available in DSpace on 2015-05-14T12:59:51Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 2644310 bytes, checksum: 2bb61cfd68e68c24b1d4a31bbf372a45 (MD5) Previous issue date: 2008-12-18 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The use of plants as a treatment method has gained prominence and became fashionable in the world. In Brazil is not different. In recent years some brazilian states has been implementing phytotherapy as an alternative therapy for the public health. However there are some drawbacks as the lack of scientific information that supporting traditional knowledge of some species. The Licania macrophylla Benth species belongs to the Chrysobalanaceae family and is known popularly as "anauera" or "anuera." The stem bark of this species is used in the state of Amapá like amebicide as antidiarrheal. The Pradosia huberi Ducke species belongs to the Sapotaceae family, and is popularly called "fresh bark" or "stick candy ' and its stem bark is used by Amazonian peoples to assist in the treatment of stomach problems and indigestion. However the use of the stem bark of these species in the preparation of herbal formulation or even home preparation is a predatory practice, because recovery of the damage caused by removal of the bark takes years to rebuild, if not eliminates the specimen. The aim of this work was the phytochemical and biological study of the Licania macrophylla Benth and Pradosia huberi (Ducke) Ducke species and compare the chemical composition of leaves and stem bark of both species, so as to suggest that you can replace the use of shells stem by the leaves, and thus contribute to the conservation of the species under discussion. The species studied were collected at Porto Grande - Amapá - Brazil and specimens are deposited in the Herbarium Amapaense HAMAB IEPA. The phytochemical study of the stem bark of the L. macrophyla Benth (Chrysobalanaceae) species led to the isolation of (-)-4'-O-methyl-epigallocatechin-3'-O-α- L-raminosídeo (LM-1), (-)-4'-methyl-epigallocatechin (Lm -2), while the leaves were isolated pheophytin A (Lm-3), 132-hydroxy-(132-S) pheophytin A (Lm-4), pheophytin B (Lm-5), β-sitosterol (Lm-6a ), stigmasterol (Lm-6b), β-sitosterol-O-glycoside (Lm-7), alcohol betulínco (Lm-8) and oleanolic acid (Lm-9), the first not reported in the literature. From species was isolated Pradosia huberi 2,3-dihidromiricetina-3-α-LO-raminosídeo (Ph-1) and leaves the fatty ester erythrodiol (Ph-2), ester of fatty oleanolic acid (Ph-3) fatty ester betulínco acid (Ph-4) and espinasterol (Ph-5), all identified by techniques 1H NMR and 13C single and two-dimensional and comparisons with published literature. Evaluation of antidiarrhoeal activity of the methanol extract of the stem bark (EMC) of L. macrophylla showed that this does not interfere with intestinal parameters: modulation of normal defecation, cathartic agent-induced diarrhea and intestinal transit stimulated. But EMC had to be active against Staphylococcus aureus ATCC 25928, Pseudomonas aeruginosa ATCC 25853 and Escherichia coli ATCC 10536, a result similar to that seen with Lm-1. The methanol extract of leaves (EMF) of L. macrophylla was active against the twelve bacterial strains tested, a result similar to that observed with Lm-4 and Lm-9. Regarding the chemical constituents isolated from the stem bark and leaves in two species can state that are not similar. Regarding the antimicrobial activity of EMC and EMF were similar, suggesting that the activity is antidiarrhoeal proven that one should only antimicrobial can be no substitution of the stem bark of the leaves. / O uso das plantas como recurso terapêutico tem ganhado destaque e tornado modismo no mundo. No Brasil não é diferente, e nos últimos anos alguns estados da federação vem implantando a fitoterapia como alternativa terapêutica para o sistema único de saúde. Porém algumas dificuldades são encontradas, entre elas a falta de informações científicas que subsidie o conhecimento tradicional de determinadas espécies. A espécie Licania macrophylla Benth pertence a família Chrysobalanaceae e é conhecida popularmente por anauera ou anuera . As cascas do caule dessa espécie é usada no estado do Amapá como antidiarréica e amebicida. A espécie Pradosiahuberi Ducke, pertence à família Sapotaceae, e é designada popularmente de casca doce ou pau doce , suas cascas do caule são usadas pelos povos amazônicos como auxiliar no tratamento de problemas gástricos e má digestão. No entanto o uso das cascas do caule dessas espécies na preparação de fitoterápico ou mesmo em preparações caseiras é uma prática predatória, pois a recuperação do dano causado pela retirada das cascas leva anos para sua reconstituição, quando não elimina o espécime. O objetivo deste trabalho foi realizar o estudo fitoquímico e biológico das espécies Licania macrophylla Benth e Pradosia huberi (Ducke) Ducke e comparar a composição química entre folhas e cascas do caule das duas espécies, de forma a sugerir se é possível substituir o uso das cascas do caule pelas folhas, e assim contribuir com a conservação das espécies em discussão. As espécies estudadas foram coletadas no município de Porto Grande Amapá Brasil e exsicatas estão depositadas no Herbário Amapaense HAMAB do IEPA. O estudo fitoquímico das cascas do caule da espécie L. macrophyla Benth (Chrysobalanaceae) levou ao isolamento de (-)- 4 -O-metil-epigalocatequina-3 -O-α-L-raminosídeo (Lm-1), (-)-4 -metil-epigalocatequina (Lm-2), enquanto das folhas foram isoladas feofitina A (Lm-3), 132-hidroxi-(132-S)- feofitinaA (Lm-4), feofitina B (Lm-5), β-sitosterol (Lm-6a), estigmasterol (Lm-6b), β-Oglicosídeo- sitosterol (Lm-7), álcool betulínco (Lm-8) e ácido oleanólico (Lm-9), sendo o primeiro não relatado na literatura. Da espécie Pradosiahuberi foi isolado 2,3- dihidromiricetina-3-α-L-O-raminosídeo (Ph-1) e das folhas éster graxo do eritrodiol (Ph- 2), éster graxo do ácido oleanólico (Ph-3), éster graxo do ácido betulínco (Ph-4) e espinasterol (Ph-5), todas identificadas através de técnicas de RMN de 1H e 13C uni e bidimensionais e comparações com a literatura. A avaliação da atividade antidiarréica do extrato metanólico das cascas do caule (EMC) de L. macrophylla mostrou que esse não interfere nos parâmetros intestinais: modulação da defecação normal; diarréia induzida por agente catártico e trânsito intestinal estimulado. Porém EMC apresentou-se ativo frente à Staphylococcus aureus ATCC 25928, Pseudomonas aeruginosa ATCC 25853 e Escherichia coli ATCC 10536, resultado semelhante ao obtido com Lm-1. O extrato metanólico das folhas (EMF) de L. macrophylla mostrou-se ativo frente as doze cepas bactérianas testadas, resultado semelhante ao observado com Lm-4 e Lm-9. No que se refere aos constituintes químicos isolados das cascas do caule e folhas nas duas espécies pode-se afirmar que não são semelhantes. Já em relação a atividade antimicrobiana do EMC e EMF esses apresentaram-se semelhantes, sugerindo que se a atividade antidiarréica fica comprovada que se deve apenas a ação antimicrobiana pode-se haver substituição do uso das cascas do caule pela folhas.
8

Avaliação da atividade antioxidante e antimicrobiana de extratos de araçá (Psidium grandifolium Mart. ex DC.) obtidos por líquido pressurizado (PLE) e por fluido supercrítico (SFE) / Evaluation of the antioxidante and atimicrobial activity of araçá extracts (Psidium grandifolium Mart. ex DC.) obtained by pressurized liquid extraction (PLE) and supercritical fluid extraction (SFE)

Bittencourt, Gabriela Marques 26 July 2018 (has links)
O araçá é um fruto, pertencente à espécie Psidium grandifolium Mart. ex DC, nativo da mata atlântica brasileira pouco caracterizado pela literatura ciêntífica. Esta pesquisa visou estudar o rendimento de extração e avaliar as atividades antioxidante e antimicrobiana do óleo essencial de araçá obtido por extração com dióxido de carbono supercrítico (SFE) e dos diferentes extratos obtidos por extração com etanol pressurizado (PLE) seguindo um delineamento composto central rotacional com temperatura e tempo estático como variáveis independentes estudadas. Avaliou-se também o perfil de voláteis do óleo essencial, o teor de compostos fenólicos totais dos extratos etanólicos e as alterações causadas na matriz vegetal por diferentes processos de extração. Com a SFE conseguiu-se extrair toda a fração lipídica do fruto (2,33% &plusmn; 0,04.10-2%), a análise dos compostos voláteis do óleo essencial obtido permitiu inferir que este possui diversos compostos com potencial bioativo tais como E-cariofileno (17.56%), &alpha;-humuleno (16,26%) e &beta;-sesquifelandreno (14.27%); porém este óleo essencial não apresentou atividade antioxidante relevante. O extrato etanólico com maior rendimento (17, 49%) foi obtido a 74 °C por 6 min, mesma condição em que obteve-se a maior atividade antioxidante (EC50 = 6,37 mg/mL), porém o maior teor de compostos fenólicos totais (136,95 mg EGA/100 g de massa seca) foi obtido quando aplicou-se 60°C por 9 min. Em relação à atividade antimicrobiana, tanto os extratos obtidos por PLE quanto por SFE apresentaram atividade contra cepas de P. aeruginosa, S. aureus e B. cereus, somente extratos etanólicos apresentaram atividade contra cepas de L. monocytogenes e nenhum dos extratos apresentaram atividade contra cepas de B. subtilis, E. coli e Salmonella. Em ambos os extratos foi possível identificar compostos com potencial aplicação farmacológica. O estudo de processos de extração que envolvam inovação tecnológica na obtenção extratos com atividade biológica visa contribuir com o extrativismo consciente ou estimular o plantio em maior escala de mais um fruto tropical empregado na medicina popular brasileira. / The araçá is a fruit, belonging to the species Psidium grandifolium Mart. ex DC, native of the Brazilian Atlantic Forest, is not largely characterized by the scientific literature. This research work aimed to study the extraction yield and to evaluate the antioxidant and antimicrobial activities of the araçá essential oil obtained by supercritical carbon dioxide extraction (SFE) and the different extracts obtained by pressurized ethanol extraction (PLE) following a central composite design with temperature and static time as independent variables studied. It was also evaluated the volatile profile of the essential oil, the content of total phenolic compounds of the ethanolic extracts and the changes caused in the vegetal matrix by different extraction processes. SFE was able to extract the whole lipid fraction of the fruit (2.33% &plusmn; 0.04.10-2%), the analysis of the volatile compounds of the essential oil obtained allowed to infer that it has several compounds with bioactive potential such as E-caryophyllene (17.56%), &alpha;-humulene (16.26%) and &beta;-sesquipelandene (14.27%); but this essential oil had no relevant antioxidant activity. The highest ethanolic extract (17, 49%) was obtained at 74 °C for 6 min, the same condition in which the highest antioxidant activity was obtained (EC50 = 6.37 mg/mL), but the higher content of total phenolics contente (136.95 mg EGA / 100 g dry mass) was obtained when 60 °C was applied for 9 min. In relation to the antimicrobial activity, both extracts obtained by PLE and SFE showed activity against P. aeruginosa, S. aureus and B. cereus strains, only ethanolic extracts showed activity against L. monocytogenes strains and none of the extracts presented activity against B. subtilis, E. coli and Salmonella strains. In both extracts it was possible to identify compounds with potential pharmacological application. The study of extraction processes that involve technological innovation in obtaining extracts with biological activity aims to contribute to the conscious extraction or stimulate the larger scale cultivation of another tropical fruit used in Brazilian popular medicine.
9

Avaliação da atividade antioxidante e antimicrobiana de extratos de araçá (Psidium grandifolium Mart. ex DC.) obtidos por líquido pressurizado (PLE) e por fluido supercrítico (SFE) / Evaluation of the antioxidante and atimicrobial activity of araçá extracts (Psidium grandifolium Mart. ex DC.) obtained by pressurized liquid extraction (PLE) and supercritical fluid extraction (SFE)

Gabriela Marques Bittencourt 26 July 2018 (has links)
O araçá é um fruto, pertencente à espécie Psidium grandifolium Mart. ex DC, nativo da mata atlântica brasileira pouco caracterizado pela literatura ciêntífica. Esta pesquisa visou estudar o rendimento de extração e avaliar as atividades antioxidante e antimicrobiana do óleo essencial de araçá obtido por extração com dióxido de carbono supercrítico (SFE) e dos diferentes extratos obtidos por extração com etanol pressurizado (PLE) seguindo um delineamento composto central rotacional com temperatura e tempo estático como variáveis independentes estudadas. Avaliou-se também o perfil de voláteis do óleo essencial, o teor de compostos fenólicos totais dos extratos etanólicos e as alterações causadas na matriz vegetal por diferentes processos de extração. Com a SFE conseguiu-se extrair toda a fração lipídica do fruto (2,33% &plusmn; 0,04.10-2%), a análise dos compostos voláteis do óleo essencial obtido permitiu inferir que este possui diversos compostos com potencial bioativo tais como E-cariofileno (17.56%), &alpha;-humuleno (16,26%) e &beta;-sesquifelandreno (14.27%); porém este óleo essencial não apresentou atividade antioxidante relevante. O extrato etanólico com maior rendimento (17, 49%) foi obtido a 74 °C por 6 min, mesma condição em que obteve-se a maior atividade antioxidante (EC50 = 6,37 mg/mL), porém o maior teor de compostos fenólicos totais (136,95 mg EGA/100 g de massa seca) foi obtido quando aplicou-se 60°C por 9 min. Em relação à atividade antimicrobiana, tanto os extratos obtidos por PLE quanto por SFE apresentaram atividade contra cepas de P. aeruginosa, S. aureus e B. cereus, somente extratos etanólicos apresentaram atividade contra cepas de L. monocytogenes e nenhum dos extratos apresentaram atividade contra cepas de B. subtilis, E. coli e Salmonella. Em ambos os extratos foi possível identificar compostos com potencial aplicação farmacológica. O estudo de processos de extração que envolvam inovação tecnológica na obtenção extratos com atividade biológica visa contribuir com o extrativismo consciente ou estimular o plantio em maior escala de mais um fruto tropical empregado na medicina popular brasileira. / The araçá is a fruit, belonging to the species Psidium grandifolium Mart. ex DC, native of the Brazilian Atlantic Forest, is not largely characterized by the scientific literature. This research work aimed to study the extraction yield and to evaluate the antioxidant and antimicrobial activities of the araçá essential oil obtained by supercritical carbon dioxide extraction (SFE) and the different extracts obtained by pressurized ethanol extraction (PLE) following a central composite design with temperature and static time as independent variables studied. It was also evaluated the volatile profile of the essential oil, the content of total phenolic compounds of the ethanolic extracts and the changes caused in the vegetal matrix by different extraction processes. SFE was able to extract the whole lipid fraction of the fruit (2.33% &plusmn; 0.04.10-2%), the analysis of the volatile compounds of the essential oil obtained allowed to infer that it has several compounds with bioactive potential such as E-caryophyllene (17.56%), &alpha;-humulene (16.26%) and &beta;-sesquipelandene (14.27%); but this essential oil had no relevant antioxidant activity. The highest ethanolic extract (17, 49%) was obtained at 74 °C for 6 min, the same condition in which the highest antioxidant activity was obtained (EC50 = 6.37 mg/mL), but the higher content of total phenolics contente (136.95 mg EGA / 100 g dry mass) was obtained when 60 °C was applied for 9 min. In relation to the antimicrobial activity, both extracts obtained by PLE and SFE showed activity against P. aeruginosa, S. aureus and B. cereus strains, only ethanolic extracts showed activity against L. monocytogenes strains and none of the extracts presented activity against B. subtilis, E. coli and Salmonella strains. In both extracts it was possible to identify compounds with potential pharmacological application. The study of extraction processes that involve technological innovation in obtaining extracts with biological activity aims to contribute to the conscious extraction or stimulate the larger scale cultivation of another tropical fruit used in Brazilian popular medicine.

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