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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.
31

Avaliação de interações do ácido gálico frente a adjuvantes empregados em formas farmacêuticas sólidas / Evaluation of the interacion of gallic acid and pharmaceutical excipients employed in solid dosage forms

Longhini, Renata January 2006 (has links)
Neste trabalho foram avaliados o comportamento do ácido gálico e de adjuvantes tecnológicos frequentemente empregados em formas farmacêuticas sólida, e das suas misturas físicas, através de métodos termoanalíticos e por espectroscopia de infravermelho. Foi investigada também a influência da compactação sobre as misturas físicas equiponderais. Os adjuvantes avaliados foram amidoglicolato de sódio, celulose microcristalina, croscarmelose sódica, crospovidona, dióxido de silício coloidal, estearato de magnésio e polimetacrilato. O ácido gálico apresentou um comportamento térmico diferenciado nas misturas, assumindo, provavelmente, uma forma instável com menor ponto de fusão. Os resultados obtidos por DSC demonstraram interação de natureza física com mudança de entalpia para misturas do ácido gálico com celulose microcristalina, crospovidona, estearato de magnésio e polimetacrilato. A interação não pode ser confirmada por espectroscopia de infravermelho para a crospovidona e polimetacrilato, devido à sobreposição das bandas com o ácido gálico. Os demais adjuvantes também apresentaram interação física, porém, sem alteração da entalpia, confirmada por espectroscopia de infravermelho, relacionada ao estabelecimento de ligações de hidrogênio entre os componentes da mistura. A compactação demonstrou particular influência sobre a interação com celulose microcristalina, croscarmelose sódica e crospovidona. / In this work were evaluated the behavior of the gallic acid and technological excipients used in sold dosage forms and their physical powder mixtures, by Differential Scanning Calorimetry (DSC) and Thermogravimety (TGA) and infrared spectroscopy (IR). The influence of the compression force on the 1:1 (w/w) physical mixtures was also investigated. The excipients evaluated were sodium starch glycolate, microcrystalline cellulose, croscarmellose sodium, crospovidone, colloidal silicon dioxide, magnesium stearate and polymethacrylate. Gallic acid presented a different thermal behavior in the mixtures, assuming, probably, an unstable form with a lower melting point. The results obtained by (DSC) demonstrated the occurrence of physical interactions with enthalpy changes for the mixtures of gallic acid with microcrystalline cellulose, crospovidone, magnesium stearate and polymethacrylate. The interaction could not be confirmed by infrared spectroscopy for crospovidone and polymethacrylate, due to overlapping of the gallic acid IR bands. The other excipients also presented physical interaction, however, without alteration of the enthalpy, confirmed by IR, which could be correlated to the establishment of hydrogen bonds between the components of the mixture. The compression of the powder mixtures demonstrated a particular influence of the interaction of gallic acid with microcrystalline cellulose, croscarmellose sodium and crospovidone.
32

Avaliação de interações do ácido gálico frente a adjuvantes empregados em formas farmacêuticas sólidas / Evaluation of the interacion of gallic acid and pharmaceutical excipients employed in solid dosage forms

Longhini, Renata January 2006 (has links)
Neste trabalho foram avaliados o comportamento do ácido gálico e de adjuvantes tecnológicos frequentemente empregados em formas farmacêuticas sólida, e das suas misturas físicas, através de métodos termoanalíticos e por espectroscopia de infravermelho. Foi investigada também a influência da compactação sobre as misturas físicas equiponderais. Os adjuvantes avaliados foram amidoglicolato de sódio, celulose microcristalina, croscarmelose sódica, crospovidona, dióxido de silício coloidal, estearato de magnésio e polimetacrilato. O ácido gálico apresentou um comportamento térmico diferenciado nas misturas, assumindo, provavelmente, uma forma instável com menor ponto de fusão. Os resultados obtidos por DSC demonstraram interação de natureza física com mudança de entalpia para misturas do ácido gálico com celulose microcristalina, crospovidona, estearato de magnésio e polimetacrilato. A interação não pode ser confirmada por espectroscopia de infravermelho para a crospovidona e polimetacrilato, devido à sobreposição das bandas com o ácido gálico. Os demais adjuvantes também apresentaram interação física, porém, sem alteração da entalpia, confirmada por espectroscopia de infravermelho, relacionada ao estabelecimento de ligações de hidrogênio entre os componentes da mistura. A compactação demonstrou particular influência sobre a interação com celulose microcristalina, croscarmelose sódica e crospovidona. / In this work were evaluated the behavior of the gallic acid and technological excipients used in sold dosage forms and their physical powder mixtures, by Differential Scanning Calorimetry (DSC) and Thermogravimety (TGA) and infrared spectroscopy (IR). The influence of the compression force on the 1:1 (w/w) physical mixtures was also investigated. The excipients evaluated were sodium starch glycolate, microcrystalline cellulose, croscarmellose sodium, crospovidone, colloidal silicon dioxide, magnesium stearate and polymethacrylate. Gallic acid presented a different thermal behavior in the mixtures, assuming, probably, an unstable form with a lower melting point. The results obtained by (DSC) demonstrated the occurrence of physical interactions with enthalpy changes for the mixtures of gallic acid with microcrystalline cellulose, crospovidone, magnesium stearate and polymethacrylate. The interaction could not be confirmed by infrared spectroscopy for crospovidone and polymethacrylate, due to overlapping of the gallic acid IR bands. The other excipients also presented physical interaction, however, without alteration of the enthalpy, confirmed by IR, which could be correlated to the establishment of hydrogen bonds between the components of the mixture. The compression of the powder mixtures demonstrated a particular influence of the interaction of gallic acid with microcrystalline cellulose, croscarmellose sodium and crospovidone.
33

Biotransformação dos ácidos gálico e elágico por microorganismos do cerrado brasileiro / Biotransformation acid gallic and ellagic by microorganisms of the brasilian cerrado

Silva, Liliane de Sousa 30 September 2015 (has links)
Submitted by Marlene Santos (marlene.bc.ufg@gmail.com) on 2016-06-01T20:07:51Z No. of bitstreams: 2 Dissertação - Liliane de Sousa Silva - 2015.pdf: 4894695 bytes, checksum: ef4469d862b59150ebb61ed28e1293ff (MD5) license_rdf: 19874 bytes, checksum: 38cb62ef53e6f513db2fb7e337df6485 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-06-02T15:32:33Z (GMT) No. of bitstreams: 2 Dissertação - Liliane de Sousa Silva - 2015.pdf: 4894695 bytes, checksum: ef4469d862b59150ebb61ed28e1293ff (MD5) license_rdf: 19874 bytes, checksum: 38cb62ef53e6f513db2fb7e337df6485 (MD5) / Made available in DSpace on 2016-06-02T15:32:33Z (GMT). No. of bitstreams: 2 Dissertação - Liliane de Sousa Silva - 2015.pdf: 4894695 bytes, checksum: ef4469d862b59150ebb61ed28e1293ff (MD5) license_rdf: 19874 bytes, checksum: 38cb62ef53e6f513db2fb7e337df6485 (MD5) Previous issue date: 2015-09-30 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / The gallic acid (GA) and its derived ellagic acid (EA) are widely distributed in nature tannins, present in tea, red wine, fruit, drinks and various medicinal plants. AG and AE are known to have anti inflammatory properties, antimutagenic, anticancerígenica and antioxidant activity. To produce functionalized derivatives of such compounds by biotransformation with filamentous fungi is an efficient and sustainable alternative, due to their ability to catalyze further reactions regio and stereo-selective. The aim of this study was to apply strains of Cerrado in the biotransformation of AG and AE. For this Thin Layer Chromatography (TLC) and High Performance Liquid Chromatography (HPLC) to monitor the production of derivatives developed analytical methodologies. Five strains of the Brazilian Cerrado were selected, these are Beauveria sp. IP06, IP08, IP94, IP98 and IP153. Incubation was performed in two different culture media: Glucose and "corn steep" for 96 hours at 27 C and 200 rpm. At the end of incubation the extraction and purification of the derivatives was performed. All strains were effective for biotranformação compounds. The culture medium influenced quali-quantitatively the production of derivatives, "corn steep" provided greater variety of substrates for both derivatives. The obtained derivatives were characterized by MS, ¹H NMR, HSQC, HMBC, UV and CCD. Derivatives of fatty acids are: benzoic acid, 3-O-methyl-β-glucopyranosyl galatoester (Labiocon 465); benzoic acid, 4 - [[6-O- (3,4-dihydroxy-5-methoxybenzoic acid)-α-D-glucopyranoside]oxy]-3-hydroxy-5metoxi (Labiocon 484); gallic acid 3-O-β-glucopiranoside (510 Labiocon) and 3,4-dihydroxy-5-methoxy-benzoic acid 2-hydroxy-5-methoxycarbonyl-phenyl ester (Labiocon 530). The AE is derived from 3,8-Dimethoxy-dibenzo [b, d] pyran-6-one ellagic acid (511 Labiocon) and 4-O, 3'-O-methyl -β-D-glucose (Labiocon 534) . / O ácido gálico (AG) e o seu derivado o ácido elágico (AE), são taninos amplamente distribuído na natureza, presente no chá, vinho tinto, frutas, bebidas e várias plantas medicinais. AG e AE são conhecidos por apresentarem propriedades antiinflamatórias, antimutagênica, anticancerígenica e atividade antioxidante. Produzir derivados funcionalizados desses compostos por meio da biotransformação com fungos filamentosos é uma alternativa eficiente e sustentável, devido à sua capacidade para catalisar novas reações regio e estereo-seletivas. O objetivo deste trabalho foi aplicar cepas do Cerrado na biotransformação do AG e AE. Para isso foram desenvolvidas metodologias analíticas por Cromatografia em Camada Delgada (CCD) e Cromatografia Líquida de Alta Eficiência (CLAE), a fim de monitorar a produção dos derivados. Foram selecionadas cinco cepas isoladas do Cerrado brasileiro, sendo estas Beauveria sp. IP06, IP08, IP94, IP98 e IP153. A incubação foi realizada em dois meios de cultura diferentes: glicose e “Corn Steep” durante 96 horas a 27º C e 200 rpm. Ao término da incubação foi realizada a extração e purificação dos derivados. Todas as cepas mostraram-se eficazes para a biotranformação dos compostos. O meio de cultura influenciou quali-quantitativamente na produção dos derivados, o “Corn Steep” proporcionou maior variedade de derivados para ambos substratos. Os derivados obtidos foram caracterizados por EM, RMN ¹H, HSQC, HMBC, UV e CCD. Os derivados do AG são: ácido benzoico, 3-O-metil β-glucopiranosil-galatoester (Labiocon 465); ácido benzóico,4-[[6-O-(3,4-diidroxi-5-metoxibenzoico)-α-D-glucopiranosideo]oxi]-3-hidroxi-5metoxi (Labiocon 484); ácido gálico 3-O-β-glucopiranoside (Labiocon 510) e ácido 3,4-Diidroxi-5-metoxi-benzoico 2-hidroxi-5-metoxicarbonil-fenil ester (Labiocon 530). O derivado do AE é 3,8-Dimetoxi-dibenzo[b,d]piran-6-one (Labiocon 511) e o ácido elágico 4-O,3’-O-metil -β-D-glicose (Labiocon 534).
34

Síntese de candidatos a novos inibidores da enzima Hiv-integrase

Rezende Júnior, Celso de Oliveira 30 July 2010 (has links)
Submitted by isabela.moljf@hotmail.com (isabela.moljf@hotmail.com) on 2017-05-05T14:14:07Z No. of bitstreams: 1 celsodeoliveirarezendejunior.pdf: 1703037 bytes, checksum: 06b6ddaff72097b07ba5ec7185f315b5 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-05-17T13:40:18Z (GMT) No. of bitstreams: 1 celsodeoliveirarezendejunior.pdf: 1703037 bytes, checksum: 06b6ddaff72097b07ba5ec7185f315b5 (MD5) / Made available in DSpace on 2017-05-17T13:40:18Z (GMT). No. of bitstreams: 1 celsodeoliveirarezendejunior.pdf: 1703037 bytes, checksum: 06b6ddaff72097b07ba5ec7185f315b5 (MD5) Previous issue date: 2010-07-30 / CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico / Este trabalho trata da síntese de cicloexanopoliois derivados do ácido quínico, esterificados com os ácidos cafeico e gálico. Esses compostos são candidatos novos agentes antivirais, principalmente como inibidores da enzima HIV-integrase, devido à semelhança estrutural com os derivados dicafeoíl-cicloexanodiois e ácidos dicafeoíl-quínicos, potentes inibidores dessa enzima. A partir de reações de esterificação, proteção e desproteção de compostos fenólicos e cicloexanopoliois foram sintetizados 41 compostos, sendo 26 inéditos, com rendimentos que variaram de 20 a 100%. As reações de proteção e desproteção seletivas das hidroxilas foram realizadas com sucesso. Na benzilação dos compostos (1R,2S,3R,5S)-1,2-Ocicloexilideno-1,2,3,5-tetraidroxicicloexano e (1R,2S,3R,5R)-1,2-O-cicloexilideno- 1,2,3,5-tetraidroxicicloexano a metodologia por transferência de fase se mostrou mais eficiente do que a metodologia convencional. Na tentativa de clivagem seletiva dos grupos benzila dos compostos (1R,2S,3R,5S)-1,2-di-O-(3’,4’-di-O-acetil)-cafeoíl-3,5-di-O-benzil-1,2,3,5-tetraidroxicicloexano e (1R,2S,3R,5R)-1,2-di-O-(3’,4’-di-Oacetil)-cafeoíl-3,5-di-O-benzil-1,2,3,5-tetraidroxicicloexano foram utilizadas quatro metodologias diferentes obtendo-se, para cada uma, a clivagem de grupos protetores diferentes. As estruturas dos compostos obtidos foram elucidadas por espectroscopia na região do infravermelho, RMN de 1H e de 13C, além da caracterização por ponto de fusão e poder rotatório específico. Alguns compostos finais foram encaminhados para testes anti-herpes (HSV-1 e HSV-2) e para avaliação das propriedades antioxidantes e antiparasitárias e serão encaminhados para testes anti- HIV-integrase. / This work describes the synthesis of cyclohexanepoliols derived from quinic acid, esterified with caffeic and gallic acids. These compounds are candidates as new antiviral agents, particularly as inhibitors of HIV integrase, due to their structural similarity to dicaffeoyl cyclohexanediols and dicaffeoyl quinic acid derivatives, potent inhibitors of this enzyme. We synthesized 41 compounds using reactions of esterification, protection and deprotection of phenolic and cyclohexanepoliol derivatives. The reactions of protection and selective deprotection of the hydroxyl groups were performed successfully. In the benzylation of compounds (1R, 2S, 3R, 5S)-1,2-O-cyclohexylidene-1,2,3,5-tetrahydroxycyclohexane and (1R, 2S, 3R, 5R)-1,2-O-cyclohexylidene-1,2,3,5-tetrahydroxycyclohexane the methodology employing phase transfer was more efficient than the conventional method. In an attempt to cleave selectively the benzyl groups of compounds (1R, 2S, 3R, 5S)-1,2-di-O-(3',4'-di-O-acetyl)-caffeoyl-3,5-di-O-benzyl-1,2,3,5-tetrahydroxycyclohexane and (1R,2S,3R,5R)-1,2-di-O-(3',4'-di-O-acetyl)-caffeoyl-3,5-di-O-benzyl-1,2,3,5- tetrahydroxycyclo-hexane four different methodologies were used. Each procedure led to cleavage of different protecting groups. The structures of the compounds were characterized by infrared spectroscopy, 1H and 13C NMR, melting point and specific optical rotation. Final compounds were sent for testing against herpes (HSV-1 and HSV-2) and biological evaluation of their antiparasitic and antioxidant properties and will be referred for testing against HIV integrase.
35

Ionisation par faisceau d'électrons de solutions aqueuses de benzènesulfonate et naphthalènesulfonate et sous-produits / Ionization by electron beam of aqueous solutions of naphthalenesulfonate, benzenesulfonate and by-products

Alkhuraiji, Turki 17 April 2013 (has links)
Ce sujet entre dans le cadre de l'étude d'un procédé d'oxydation avancé innovant dans le domaine de la dépollution des eaux, à savoir l'ionisation par faisceau d'électrons. Le radical hydroxyle (•OH) et l'électron hydraté (e−aq) sont les deux espèces majoritaires issues de l'ionisation de solutions aqueuses par un faisceau d'électrons d'intense énergie. Il a été démontré que la génération des radicaux supplémentaires tels que le radical sulfate (SO4•−) et le radical hydroxyle par les réactions radicalaires entre l'ion persulfate, le peroxyde d'hydrogène et l'électron hydraté respectivement, améliore l'efficacité de ce procédé pour la dégradation de polluants organiques en solution aqueuse. Dans le présent travail, la dégradation et la minéralisation de benzènesulfonate et naphthalènesulfonate de sodium, et d'acide gallique ont été obtenues par irradiation par faisceau d'électrons seul et couplé avec un oxydant (S2O8−−, H2O2). En absence d'oxydant une dose absorbée de 1,5 kGy a été suffisante pour l'élimination totale de ces composés. La présence d'oxydant permet généralement de réduire les doses d'irradiation nécessaires. Par ailleurs, l'augmentation de la concentration en oxydant ou de la dose appliquée a un effet bénéfique vis-à-vis de l'élimination du carbone organique. Cependant, le couplage S2O8−−/faisceau d'électrons est plus adapté que le couplage H2O2/faisceau d'électrons même en présence de constituants inorganiques. Les résultats obtenus soulignent l'importance du rôle du dioxygène dissous lors de l'étape de la minéralisation en vue de favoriser la formation des radicaux organiques (ROO•). Pour chaque une des molécules étudiées, des sous-produits d'oxydation... / This research belongs to the study of the ionization of aqueous solutions by electron beam (E.B.) as an advanced oxidation process for water treatment. The hydroxyl radical (•OH) and hydrated electron(eaq¯) are the two major active species produced from the ionization of aqueous solutions by high energy electron beam. It has been shown that the generation of additional radicals such as the sulphate radical (SO4•¯) and hydroxyl radical from the reaction of persulfate ion (S2O8¯) or hydrogen peroxide (H2O2) with the hydrated electron, improved the efficiency of this process towards the degradation and mineralization of organic pollutants in aquaeous solution. In the présent work, the degradation and mineralization of naphthalenesulfonate, benzenesulfonate and gallic acid were studied by electron beam irradiation alone and coupled with oxidants (S2O8¯, H2O2).In the absence of oxidant, an absorbed dose of 1,5 kGy leads to total elimnation of these pollutants. The presence of added oxidants usually reduces the radiation dose required. In addition, increasing oxidant concentration or applied dose had a beneficial effect towards the organic carbon removal. It was found that coupling E.B./S2O8¯ has more suitable than E.B./ H2O2 even in the presence of inorganic constituents. The results also highlighted the importance of dissolved oxygen in the system when mineralization is aimed. For each of the molecules studied, oxidation by-products resulting from hydroxylation and aromatic ring opening were identified.
36

Characterization of (+)-Catechin and Quercetin from Pawpaw Pulp

Ahn, Jinsoo 26 July 2011 (has links)
No description available.
37

Novel methodology for the synthesis of ¹³C-Labelled phenols and its application to the total synthesis of polyphenols

Marshall, Laura J. January 2010 (has links)
The base-catalysed reaction of 4H-pyran-4-one with a range of nucleophiles, namely diethyl malonate, ethyl acetoacetate, nitromethane, acetylacetone and ethyl cyanoacetate, was developed as a reliable, high yielding method for the preparation of para-substituted phenols. The methodology was extended to include the use of the substituted pyranones, maltol, 2,6-dimethyl-4H-pyran-4-one and diethyl chelidonate. Reactions were studied using conventional heating methods and microwave irradiation. Microwave irradiation had definite beneficial effects, with improved yields, reduced reaction times and cleaner reaction profiles. The potential of this methodology was examined for the regioselective placement of ¹³C-atoms into benzene rings using ¹³C-labelled nucleophiles or ¹³C-labelled 4H-pyran-4-ones. [3,5-13C₂]4H-Pyran-4-one and [2,6-13C₂]4H-pyran-4-one were prepared from various ¹³C-labelled versions of triethyl orthoformate and acetone. This methodology was applied to the synthesis of [1,3,5-¹³C₃]gallic acid, via the base-catalysed reaction of [3,5-¹³C₂]4H-pyran-4-one with diethyl [2-¹³C]malonate, followed by subsequent transformations to yield [1,3,5-¹³C₃]gallic acid. The preparation of [2-¹³C]phloroglucinol was carried out via [2-¹³C]resorcinol, with regioselective placement of a single ¹³C-atom into the aromatic ring. This was accomplished from non-aromatic precursors, with the source of the ¹³C-atom being [¹³C]methyl iodide. The key step in this synthesis was the introduction of the third hydroxyl group, which was achieved using a modified iridium-catalysed C-H activation/borylation/oxidation procedure. The scope of an existing C-H activation/borylation reaction was modified and expanded to include a range of protected resorcinol derivatives. A catalyst system was developed which allowed high conversion to the intermediate arylboronic acids, followed by oxidation using aqueous Oxone® to yield the corresponding phenols. Finally, to demonstrate the potential of these new methods for application in the synthesis of isotopically labelled natural products and polyphenols, the syntheses of ¹³C-labelled anthocyanins were studied. A route was developed that could be applied to the synthesis of either cyanidin-3-glucoside or delphinidin-3-glucoside. Only the final coupling/cyclisation step to yield the desired anthocyanin targets remains to be carried out.
38

Investigação da atividade antioxidante in vitro e da composição química de diferentes extratos de plantas medicinais / Investigation about in vitro antioxidant activity and chemical composition of different extracts from medicinal

Pereira, Romaiana Picada 18 March 2011 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / Oxidative stress (OS) is involved in the development of several disorders involving the central nervous system, such as Alzheimer s disease (AD). Considering the limitations of current therapeutics for AD, there is still a great demand for discovery of new medical alternatives. In the first part of the present study it was investigated the antioxidant capacity and the chemical composition of three plants popularly used to treat neurological disorders: Melissa officinalis, Matricaria recutita and Cymbopogon citratus. The antioxidant effect of some phenolic compounds was also examined for comparative purposes. All plant extracts were effective in to combat OS, but Melissa officinalis presented the highest antioxidant effect. Among the purified compounds, quercetin had the highest antioxidant activity followed by gallic acid, quercitrin and rutin. In this work, we have demonstrated that the plant extracts could protect against OS induced by various pro-oxidant agents that induce lipid peroxidation by different process. Based on this study, which indicates that Melissa officinalis could be an effective agent in the prevention of various neurological diseases associated with OS. In the second part of this study, it was investigated the chemical composition and antioxidant activity of different fractions from Melissa officinalis extract. Furthermore, it was verified the effect of the most antioxidant fraction on acethylcholinesterase (AChE) activity and the effect of gallic acid on the matrix metalloproteinase-2 (MMP-2) activity. Ethyl acetate fraction presented the highest flavonoids content as well as antioxidant activity when compared with other tested fractions and also it caused AChE inhibition. Moreover, gallic acid inhibited MMP-2 activity. In conclusion, M. officinalis ethyl acetate fraction is suggested to be further investigated for its possible use in the treatment of AD, due its antioxidant, anticholinesterase activities and the MMP-2 inhibitory capacity of their phenolic compound, gallic acid. / O estresse oxidativo (EO) está envolvido no desenvolvimento de várias doenças relacionadas ao sistema nervoso central, tal como a Doença de Alzheimer (DA). Considerando as limitações da terapia existente para a DA, existe ainda a necessidade de novas alternativas médicas. Na primeira parte deste estudo, foi investigada a capacidade antioxidante e a composição química de três plantas usadas popularmente para tratar desordens neurológicas: Melissa officinalis, Matricaria recutita e Cymbopogon citratus. O efeito antioxidante de alguns compostos fenólicos também foi examinado para fins comparativos. Todos os extratos de plantas foram efetivos no combate ao EO induzido por diferentes agentes, mas o extrato aquoso da Melissa officinalis apresentou o maior efeito antioxidante. Dentre os compostos purificados, a quercetina teve a maior atividade antioxidante seguida pelo ácido gálico, quercitrina e rutina. Neste trabalho, foi mostrado que os extratos de plantas protegeram contra o EO induzido por vários agentes pró-oxidantes que induzem peroxidação lipídica por diferentes processos. Baseado nestes resultados, que indicam que a Melissa officinalis poderia ser um agente efetivo na prevenção de várias doenças neurológicas associadas ao EO, na segunda parte deste estudo, foram investigadas a composição química e a atividade antioxidante de diferentes frações do extrato de Melissa officinalis. Além disso, investigou-se o efeito da fração com maior potencial antioxidante na atividade da acetilcolinesterase (AChE) e o efeito do ácido gálico na atividade da metaloproteinase-2 da matriz (MMP-2). A fração acetato de etila apresentou maior conteúdo de flavonóides associada a uma maior atividade antioxidante quando comparado com as outras frações testadas e causou inibição da AChE. Além disso, o ácido gálico inibiu a atividade da MMP-2. Desta forma, sugere-se que a fração acetato de etila da M. officinalis poderia ser melhor investigada para o seu possível uso no tratamento da DA, devido às suas atividades antioxidante e anticolinesterase e a capacidade do ácido gálico, composto fenólico presente em sua composição, inibir a MMP-2.
39

BIOPROSPECÇÃO DA GEOPRÓPOLIS DE MELIPONA FASCICULATA SMITH COMO INSUMO NA GERAÇÃO DE PRODUTOS LEISHMANICIDAS / BIOPROSPECTING OF GEOPROPOLIS OF MELIPONA FASCICULATA SMITH AS INPUT IN GENERATION OF LEISHMANICIDAL PRODUCTS

Dutra, Richard Pereira 19 September 2012 (has links)
Made available in DSpace on 2016-08-16T18:18:41Z (GMT). No. of bitstreams: 1 Tese Richard Pereira Dutra.pdf: 10110933 bytes, checksum: 21ac06ca1d01c91986e9b53d029d42ea (MD5) Previous issue date: 2012-09-19 / FUNDAÇÃO DE AMPARO À PESQUISA E AO DESENVOLVIMENTO CIENTIFICO E TECNOLÓGICO DO MARANHÃO / Melipona fasciculataSmith, occurs in Brazil, especially in the state of Maranhão, where it is popularly known as tiúba . The tiúba produces honey, wax, pollen and geopropolis. The aim of this study was to evaluate the leishmanicidal activity of different samples of geopropolis Melipona fasciculata, aiming to produce a product with leishmanicidal activity. Geopropolis samples were collected in different localities of the municipality of Fernando Falcão-MA and subjected to extractive process withhydroalcoholic solution, obtaining the hydroalcoholic extracts of geopropolis (HEG1, and HEG2 HEG3). The extracts were used for in vitro evaluation of leishmanicidal action, using promastigotes of Leishmania amazonensis. The HEG1, with the highest leishmanicidal activity, was subjected to liquid-liquid partition, resulting in hexanefraction (FH), chloroform fraction (CF), ethyl acetate fraction (AF) and hydroalcoholic fraction (FHA). The fractions were assessed for leishmanicidal activity and antioxidant, and also analyzed for total polyphenol concentration and chemical composition. Extracts of geopropolis showed inhibitory concentration (IC50) between 47-229 μg/mL. The most active extract was EHG1 and its most active fraction was the FA with IC50 of 29.89 μg/mL, while the IC50 FC fractions and FHA showed IC50of 43.21 μg/mL and 49.48 μg/mL, respectively. The HEG1 and fractions leishmanicidalshowed antioxidant activity towards DPPH and high levels of total polyphenols. The hexane fraction showed no leishmanicidal action, and had the lowest antioxidant concentrations of polyphenols. The extracts showed phenolic acids, organic acids, fatty acids, anthraquinones, sugars and alcohols, the analysis by gas chromatography-mass spectrometry (GC-MS). The most active fraction (AF) showed mainly gallic acid, while the other fractions were identified fatty acids, organic acids, anthraquinones, diterpenes, triterpenes, steroids, sugars and alcohols. In the analysis by High performance liquidchromatographycoupled tomass spectrometry (HPLC-MS) extract the most active fraction were identified phenolic acids, ellagitannins and gallotannins, confirming the data obtained by GC-MS. Based on the results obtained was a byproduct that when tested under the same conditions also showed leishmanicidal action. In conclusion, the leishmanicidal activity of geopropolis Melipona fasciculata is likely to be related to the presence of gallic acid derivaties and ellagic. / Melipona fasciculataSmith, ocorre no Brasil, especialmente no estado do Maranhão, onde é popularmente conhecida como tiúba. A tiúba produz mel, cera, geoprópolis e acumula pólen. O objetivo deste trabalho foi avaliar a atividade leishmanicida de diferentes amostras da geoprópolis de Melipona fasciculata, visando à obtenção de um produto com atividade leishmanicida. As amostras de geoprópolis foram coletadas em diferentes localidades do município de Fernando Falcão-MA e submetidas a processo extrativo com solução hidroalcoólica, obtendo-se os extratos hidroalcoólicos da geoprópolis (EHG1, EHG2 e EHG3). Os extratos foram utilizados para avaliação in vitro da ação leishmanicida, utilizando formas promastigotas de Leishmania amazonensis. O EHG1, que apresentou maior atividade leishmanicida, foi submetido à partição líquido-líquido, resultando nas frações hexânica (FH), fração clorofórmica (FC), fração acetato de etila (FA) e fração hidroalcoólica (FHA). As frações foram avaliadas quanto à atividade leishmanicida e antioxidante, e ainda analisadas quanto à concentração de polifenóis totais e composição química. Os extratos da geoprópolis apresentaram concentração inibitória (CI50) entre 47 a 229 μg/mL. O extrato mais ativo foi EHG1 e a sua fração mais ativa foi a FA com CI50 de 29,89 μg/mL, enquanto as frações FC e FHA apresentaram CI50 de 43,21 μg/mL e 49,48 μg/mL, respectivamente. OEHG1 e as frações leishmanicidas apresentaram atividade antioxidante frente ao radical DPPH e elevados teores de polifenóis totais. A fração hexânica não apresentou ação leishmanicida, antioxidante e apresentou as menores concentrações de polifenóis. Os extratos apresentaram ácidos fenólicos, ácidos orgânicos, ácidos graxos, antraquinonas, açúcares e álcoois, nas analises por cromatografia gasosa acoplada a espectrometria de massas (CG-EM). A fração mais ativa (FA) apresentou principalmente o ácido gálico, enquanto nas demais frações foram identificados ácidos graxos, ácidos orgânicos, antraquinonas, diterpenos, triterpenos, esteróides, açúcares e álcoois. Nas análises por cromatografia líquida de alta eficiência acoplada a espectrometria de massas (CLAE-EM) do extrato fração mais ativos foram identificados ácidos fenólicos, galotaninos e elagitaninos, corroborando com os dados obtidos por CG-EM. Com base nos resultados foi obtido um bioproduto que quando testado nas mesmas condições também apresentou ação leishmanicida. Concluímos que a atividade leishmanicida e antioxidante da geoprópolis de Melipona fasciculataestãopossivelmente relacionadas à presença de derivados dos ácidos gálico e elágico.
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Physicochemical and biopharmaceutical characterization of novel derivatives of gallic acid

Alhyari, Dania H. January 2022 (has links)
Gallic acid is a known antioxidant and has anti-inflammatory activity in addition to other biological activities, but GA efficiency is restricted due to low permeability and low oral bioavailability. This study was designed to investigate the solubility, permeability, oral bioavailability, enzymatic stability with cytochrome CYP2D6, antioxidant and anti-inflammatory activity of novel gallic acid sulfonamide derivatives; TMBS, and THBS. In addition, a novel in silico permeability model was designed to predict the permeability and bioavailability of eighty derivatives of GA. In sillico prediction of intestinal permeability of GA derivative indicated an increase in permeability with increased lipophilicity and decreased aqueous solubility, replacing the carboxylic group with sulfonamide group has increased intestinal permeability. A significant (P <0.01) increase was observed in the permeability of TMBS and THBS over GA, in both gastric fluids and HIEC cells. TMBS was O-demethylated by CYP2D6. TMBS had greater ROS scavenging activity than GA in HIEC-6 cells. There was a significant (P< 0.05) increase in anti-inflammatory activity of THBS, and TMBS compared to ibuprofen. TMBS, and THBS had better oral bioavailability than GA. This data suggests that the in silico permeability model can be used in the future to study new candidate of gallic acid, and further in vivo and clinical investigations are required to introduce TMBS and THBS as a new antioxidant and anti-inflammatory drugs.

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