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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

A Synthetic Approach to the Biflavonoids Chamaejasmine and Isochamaejasmine

Baron, Verna B 13 December 2014 (has links)
Biflavonoids form a ubiquitous class of compounds in nature, which are well known for their numerous medicinal benefits. Biflavonoids such as chamaejasmine and isochamaejasmine have been shown to exhibit pharmacological activity such as anitidiabetic, anti-malaria, anti- HIV, anticancer etc. Biflavanones, chamaejasmine and isochamaejasmine are dimers of the flavanone narigenin at the C-3 position, which gives them a rare 3/3" C - C linkage. They are structurally similar in that they both have four stereocenters. The difference between these two compounds is the stereochemistry at the C-2" and C-3". In this study, installation of each of these stereocenters will be targeted at different stages of the synthesis. Installation of the stereocenters at C-2 and C-3 was achieved through the cyclopropanation of a 2-aryl-2H-chromene, followed by the tin (II) triflate catalyzed rearrangement of the cyclopropane into a gamma-lactone. This gamma-lactone provided the core structure for one of the flavanone units in the targeted biflavonoids, as well as providing the building block for the second flavanone unit. For the construction of the second flavanone unit the gamma-lactone was transformed into a chalcone precursor, which served as the platform for the installation of the other two stereocenters in the biflavonoids. The construction of the chalcone precursor was achieved first through the synthesis of an alpha-benzylidene lactone. Several attempts were made to open this alpha-benzylidene lactone via the addition of an aryllithium, which proved to be a challenge. This problem was resolved through the opening of the alpha-benzylidene lactone via reduction with Red-Al, subsequent formation of an aldehyde, and then addition of the aryllithium to the aldehyde. Successful synthesis of the chalcone precursor was achieved through the oxidation of the product of the aryllithium addition, albeit in a modest yield (43 %). Herein, studies related towards the synthesis of chamaejasmine and isochamaejasmine are presented.
2

Antioxidative and vascular relaxing effects of black tea theaflavins. / CUHK electronic theses & dissertations collection

January 2003 (has links)
by Su Ya Lun. / "August 2003." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (p. 163-181). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.
3

Potencial inibitório in vitro de biflavonoides de Garcinia gardneriana : um estudo sobre monoamina oxidades e CYP19 (aromatase)

Recalde Gil, Maria Angélica January 2015 (has links)
The plant Garcinia gardneriana (Planch. & Triana) Zappi, popularly known in Brazil as "bacupari" has traditionally been used for various types of inflammatory diseases and the evaluation of their chemical composition, mainly of leaves, has resulted in biflavonoids as major compounds. These phenolic compounds have shown anti-inflammatory activity validating the popular use of the plant. In this work was isolated from dried branches of Garcinia gardneriana the biflavonoids: morelloflavone, that is an naringenin covalently linked to luteolin, Gb-2a which is an naringenin linked to eriodictyol and Gb-2a- 7-O-glucose. These compounds have been previously evaluated in various activities such as anti-inflammatory and anti-antioxidants but there is no report of its activity as enzymatic inhibitors. However, the monomers that form it, have been evaluated in the inhibition of aromatase and antidepressant activity with positive outcome, which commonly are used MAO-A inhibitors. In the isolation process were also founded terpenoid compounds as lupeol and friedelin The isolated and purified biflavonoids were used to evaluate enzyme inhibition "in vitro" in monoamine oxidases (MAO-A MAO-B) and aromatase. The compounds showed a positive response even of IC50 5,47 μM and 1,35 μM for MAO-A inhibition of and aromatase enzyme respectively; discovering a way for a new proposal to link both enzymes for treatment of hormone-dependent cancers and anxiety and depression disorders. / La planta Garcinia gardneriana (Planch. & Triana) Zappi, popularmente conocida en Brasil como "bacupari" ha sido tradicionalmente usada para varios tipos de enfermedades inflamatorias y la evaluación de su composición química, principalmente de las hojas, ha resultado en biflavonoides como compuestos mayoritarios. Estos compuestos fenólicos han demostrado actividad anti-inflamatória validando el uso popular de la planta. En este trabajo se asilaron a partir de tallos secos de la Garcinia gardneriana los biflavonoides: moreloflavona, que consiste en una naringenina unida covalentemente a luteolina, Gb-2a que es un compuesto que consiste en una naringenina unida a un eriodictyol y Gb-2a-7-O-glucose. Estos compuestos ya han sido previamente evaluados en diversas actividades como anti inflamatorios y anti antioxidantes pero no se tiene reporte de su actividad como inhibidores enzimáticos. Sin embargo, los monomeros que los conforman han sido evaluados en la inhibición de la aromatasa y con resultados positivos como en la actividad antidepresiva, para la cual comúnmente son usados los inibidores de MAO-A. En el proceso de aislamiento también fueron encontrados compuestos terpenoides como lupeol y friedelina. Los biflavonoides aislados y purificados se usaron para evaluar la inhibición enzimática “in vitro” en monoaminooxidasas (MAO-A, MAO-B) y aromatasa. Los compuestos presentaron una respuesta positiva calculada con IC50 de hasta 5,47 μM y 1,35 μM para la inhibición de las enzimas MAO-A y aromatasa respectivamente, abriendo el camino a una nueva propuesta de relacionar estas dos enzimas para tratamiento de cánceres hormonodependientes y transtornos de ansiedad y depresión.
4

Detecção in silico, isolamento e caracterização estrutural dos constitutintes micromoleculares antimaláricos e antioxidantes em galhosmdemGarcina gardneriana (Clusiaceae) /

Burgos, Rosilene Cristina Rossetto. January 2010 (has links)
Resumo: Este trabalho teve como principais objetivos a detecção, isolamento e elucidação estrutural dos constituintes micromoleculares presentes em folhas e galhos de Garcinia gardneriana, uma espécie da família Clusiaceae com poucos relatos na literatura sobre a sua composição fitoquímica. A detecção das moléculas foi realizada através de abordagens in silico com o estabelecimento de perfis cromatográficos e espectrométricos dos constituintes majoritários dos extratos brutos e frações. A comparação desses dados foi realizada através de dados existentes na literatura. A partir dessa metodologia foi possível detectar 11 triterpenos por GC-FID nos extratos e frações apolares: campesterol (1), estigmasterol (2), β-sitosterol (3), β- amirenona (4), α- amirina (5), β-amirina (6), lupenona (7), lupeol (8), acetato de β-amirina (9), acetato de α-amirina (10), friedelina (11) e mais 9 biflavonóides nos extratos e frações mais polares: xantochimusídeo (12), GB2 (13), fukugisídeo (14), GB 1a glicosilado (15), GB2a (16), morelloflavona (17), volkensiflavona (18), amentoflavona (19), podocarpusflavona (20) e uma benzofenona: 7-epiclusianona (21) através da técnica HPLC-DAD-ESI-MSHRMS. Quanto aos bioensaios in vitro realizados (inibição da polimerização do heme, redução do radical DPPH (antioxidante), inibidor da enzima acetilcolinesterase, tripanocida, citotóxico, antifúngico contra fitopatógenos e patógenos humanos) em todos os extratos e frações preparados, alguns resultados merecem destaque tais como a redução do radical DPPH com IC50 de 9,5, 7,4 e 7,5 μg/mL respectivamente para o extrato etanólico dos galhos, a fração acetato de etila dos galhos e folhas, a inibição da polimerização do heme com valores de 95,7, 98,6 e 68,0 %, de inibição para o extrato etanólico das folhas, e frações acetato de etila das folhas e galhos respectivamente / Abstract: This work had as main objective the detection, isolation and structural elucidation of the micromolecular constituents from leaves and twigs of Garcinia gardneriana, a Clusiaceae species with few literature reports regarding its phytochemical composition. The detection of molecules was performed by in silico detection with the establishment of chromatographic and spectroscopic profiles of the major constituents present in the crude extracts and fractions as well as comparison of data from database and literature reports. Based on this methodology we were able to detect 11 triterpenes by GC-FID in the extracts and nonpolar fractions: campesterol (1), stigmasterol (2), β-sitosterol (3), β-amirenone (4), α- amyrin (5), β-amyrin (6), lupenone (7), lupeol (8), β-amyrin acetate (9), α-amyrin acetate (10), friedelin (11) and more 9 biflavonoids from extracts and fractions polar: xanthochymuside (12) and GB2 (13), fukugiside (14), GB1 glycosylated (15), GB2a (16), morelloflavone (17), volkensiflavone (18), amentoflavone (19) , podocarpusflavone (20), 7-epiclusianone (21) by HPLC-DAD-ESI-MS-HRMS. As for the performed in vitro bioassays (inhibition of heme polymerization, reduction of the DPPH radical (antioxidant), inhibition of the enzyme acetylcholinesterase, trypanocidal, cytotoxic antifungal activity against plant pathogens and human pathogens) in all extracts and fractions prepared in this work, some results are worthy of mentioning such as the reduction of the DPPH radical with IC50 values of 9.5, 7.4 and 7.5 μg/mL respectively for the ethanol extract from twigs, the ethyl acetate fraction from the branches and leaves, as well as the inhibition of heme polymerization with values of 95.7, 98.6 and 68.0% from the ethanol extract from the leaves, and the ethyl acetate fractions leaves and branches / Orientador: Ian Castro Gamboa / Coorientador: Márcia Nasser Lopes / Banca: Mario Sergio Palma / Banca: Carlos Alexandre Carollo / Mestre
5

Potencial inibitório in vitro de biflavonoides de Garcinia gardneriana : um estudo sobre monoamina oxidades e CYP19 (aromatase)

Recalde Gil, Maria Angélica January 2015 (has links)
The plant Garcinia gardneriana (Planch. & Triana) Zappi, popularly known in Brazil as "bacupari" has traditionally been used for various types of inflammatory diseases and the evaluation of their chemical composition, mainly of leaves, has resulted in biflavonoids as major compounds. These phenolic compounds have shown anti-inflammatory activity validating the popular use of the plant. In this work was isolated from dried branches of Garcinia gardneriana the biflavonoids: morelloflavone, that is an naringenin covalently linked to luteolin, Gb-2a which is an naringenin linked to eriodictyol and Gb-2a- 7-O-glucose. These compounds have been previously evaluated in various activities such as anti-inflammatory and anti-antioxidants but there is no report of its activity as enzymatic inhibitors. However, the monomers that form it, have been evaluated in the inhibition of aromatase and antidepressant activity with positive outcome, which commonly are used MAO-A inhibitors. In the isolation process were also founded terpenoid compounds as lupeol and friedelin The isolated and purified biflavonoids were used to evaluate enzyme inhibition "in vitro" in monoamine oxidases (MAO-A MAO-B) and aromatase. The compounds showed a positive response even of IC50 5,47 μM and 1,35 μM for MAO-A inhibition of and aromatase enzyme respectively; discovering a way for a new proposal to link both enzymes for treatment of hormone-dependent cancers and anxiety and depression disorders. / La planta Garcinia gardneriana (Planch. & Triana) Zappi, popularmente conocida en Brasil como "bacupari" ha sido tradicionalmente usada para varios tipos de enfermedades inflamatorias y la evaluación de su composición química, principalmente de las hojas, ha resultado en biflavonoides como compuestos mayoritarios. Estos compuestos fenólicos han demostrado actividad anti-inflamatória validando el uso popular de la planta. En este trabajo se asilaron a partir de tallos secos de la Garcinia gardneriana los biflavonoides: moreloflavona, que consiste en una naringenina unida covalentemente a luteolina, Gb-2a que es un compuesto que consiste en una naringenina unida a un eriodictyol y Gb-2a-7-O-glucose. Estos compuestos ya han sido previamente evaluados en diversas actividades como anti inflamatorios y anti antioxidantes pero no se tiene reporte de su actividad como inhibidores enzimáticos. Sin embargo, los monomeros que los conforman han sido evaluados en la inhibición de la aromatasa y con resultados positivos como en la actividad antidepresiva, para la cual comúnmente son usados los inibidores de MAO-A. En el proceso de aislamiento también fueron encontrados compuestos terpenoides como lupeol y friedelina. Los biflavonoides aislados y purificados se usaron para evaluar la inhibición enzimática “in vitro” en monoaminooxidasas (MAO-A, MAO-B) y aromatasa. Los compuestos presentaron una respuesta positiva calculada con IC50 de hasta 5,47 μM y 1,35 μM para la inhibición de las enzimas MAO-A y aromatasa respectivamente, abriendo el camino a una nueva propuesta de relacionar estas dos enzimas para tratamiento de cánceres hormonodependientes y transtornos de ansiedad y depresión.
6

Detecção in silico, isolamento e caracterização estrutural dos constitutintes micromoleculares antimaláricos e antioxidantes em galhosmdemGarcina gardneriana (Clusiaceae)

Burgos, Rosilene Cristina Rossetto [UNESP] 06 August 2010 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:28:32Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-08-06Bitstream added on 2014-06-13T18:34:46Z : No. of bitstreams: 1 burgos_rcr_me_araiq.pdf: 5329390 bytes, checksum: 925b0dcf4d0c43239e31000b7272f966 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Este trabalho teve como principais objetivos a detecção, isolamento e elucidação estrutural dos constituintes micromoleculares presentes em folhas e galhos de Garcinia gardneriana, uma espécie da família Clusiaceae com poucos relatos na literatura sobre a sua composição fitoquímica. A detecção das moléculas foi realizada através de abordagens in silico com o estabelecimento de perfis cromatográficos e espectrométricos dos constituintes majoritários dos extratos brutos e frações. A comparação desses dados foi realizada através de dados existentes na literatura. A partir dessa metodologia foi possível detectar 11 triterpenos por GC-FID nos extratos e frações apolares: campesterol (1), estigmasterol (2), β-sitosterol (3), β- amirenona (4), α- amirina (5), β-amirina (6), lupenona (7), lupeol (8), acetato de β-amirina (9), acetato de α-amirina (10), friedelina (11) e mais 9 biflavonóides nos extratos e frações mais polares: xantochimusídeo (12), GB2 (13), fukugisídeo (14), GB 1a glicosilado (15), GB2a (16), morelloflavona (17), volkensiflavona (18), amentoflavona (19), podocarpusflavona (20) e uma benzofenona: 7-epiclusianona (21) através da técnica HPLC-DAD-ESI-MSHRMS. Quanto aos bioensaios in vitro realizados (inibição da polimerização do heme, redução do radical DPPH (antioxidante), inibidor da enzima acetilcolinesterase, tripanocida, citotóxico, antifúngico contra fitopatógenos e patógenos humanos) em todos os extratos e frações preparados, alguns resultados merecem destaque tais como a redução do radical DPPH com IC50 de 9,5, 7,4 e 7,5 μg/mL respectivamente para o extrato etanólico dos galhos, a fração acetato de etila dos galhos e folhas, a inibição da polimerização do heme com valores de 95,7, 98,6 e 68,0 %, de inibição para o extrato etanólico das folhas, e frações acetato de etila das folhas e galhos respectivamente / This work had as main objective the detection, isolation and structural elucidation of the micromolecular constituents from leaves and twigs of Garcinia gardneriana, a Clusiaceae species with few literature reports regarding its phytochemical composition. The detection of molecules was performed by in silico detection with the establishment of chromatographic and spectroscopic profiles of the major constituents present in the crude extracts and fractions as well as comparison of data from database and literature reports. Based on this methodology we were able to detect 11 triterpenes by GC-FID in the extracts and nonpolar fractions: campesterol (1), stigmasterol (2), β-sitosterol (3), β-amirenone (4), α- amyrin (5), β-amyrin (6), lupenone (7), lupeol (8), β-amyrin acetate (9), α-amyrin acetate (10), friedelin (11) and more 9 biflavonoids from extracts and fractions polar: xanthochymuside (12) and GB2 (13), fukugiside (14), GB1 glycosylated (15), GB2a (16), morelloflavone (17), volkensiflavone (18), amentoflavone (19) , podocarpusflavone (20), 7-epiclusianone (21) by HPLC-DAD-ESI-MS-HRMS. As for the performed in vitro bioassays (inhibition of heme polymerization, reduction of the DPPH radical (antioxidant), inhibition of the enzyme acetylcholinesterase, trypanocidal, cytotoxic antifungal activity against plant pathogens and human pathogens) in all extracts and fractions prepared in this work, some results are worthy of mentioning such as the reduction of the DPPH radical with IC50 values of 9.5, 7.4 and 7.5 μg/mL respectively for the ethanol extract from twigs, the ethyl acetate fraction from the branches and leaves, as well as the inhibition of heme polymerization with values of 95.7, 98.6 and 68.0% from the ethanol extract from the leaves, and the ethyl acetate fractions leaves and branches
7

Potencial inibitório in vitro de biflavonoides de Garcinia gardneriana : um estudo sobre monoamina oxidades e CYP19 (aromatase)

Recalde Gil, Maria Angélica January 2015 (has links)
The plant Garcinia gardneriana (Planch. & Triana) Zappi, popularly known in Brazil as "bacupari" has traditionally been used for various types of inflammatory diseases and the evaluation of their chemical composition, mainly of leaves, has resulted in biflavonoids as major compounds. These phenolic compounds have shown anti-inflammatory activity validating the popular use of the plant. In this work was isolated from dried branches of Garcinia gardneriana the biflavonoids: morelloflavone, that is an naringenin covalently linked to luteolin, Gb-2a which is an naringenin linked to eriodictyol and Gb-2a- 7-O-glucose. These compounds have been previously evaluated in various activities such as anti-inflammatory and anti-antioxidants but there is no report of its activity as enzymatic inhibitors. However, the monomers that form it, have been evaluated in the inhibition of aromatase and antidepressant activity with positive outcome, which commonly are used MAO-A inhibitors. In the isolation process were also founded terpenoid compounds as lupeol and friedelin The isolated and purified biflavonoids were used to evaluate enzyme inhibition "in vitro" in monoamine oxidases (MAO-A MAO-B) and aromatase. The compounds showed a positive response even of IC50 5,47 μM and 1,35 μM for MAO-A inhibition of and aromatase enzyme respectively; discovering a way for a new proposal to link both enzymes for treatment of hormone-dependent cancers and anxiety and depression disorders. / La planta Garcinia gardneriana (Planch. & Triana) Zappi, popularmente conocida en Brasil como "bacupari" ha sido tradicionalmente usada para varios tipos de enfermedades inflamatorias y la evaluación de su composición química, principalmente de las hojas, ha resultado en biflavonoides como compuestos mayoritarios. Estos compuestos fenólicos han demostrado actividad anti-inflamatória validando el uso popular de la planta. En este trabajo se asilaron a partir de tallos secos de la Garcinia gardneriana los biflavonoides: moreloflavona, que consiste en una naringenina unida covalentemente a luteolina, Gb-2a que es un compuesto que consiste en una naringenina unida a un eriodictyol y Gb-2a-7-O-glucose. Estos compuestos ya han sido previamente evaluados en diversas actividades como anti inflamatorios y anti antioxidantes pero no se tiene reporte de su actividad como inhibidores enzimáticos. Sin embargo, los monomeros que los conforman han sido evaluados en la inhibición de la aromatasa y con resultados positivos como en la actividad antidepresiva, para la cual comúnmente son usados los inibidores de MAO-A. En el proceso de aislamiento también fueron encontrados compuestos terpenoides como lupeol y friedelina. Los biflavonoides aislados y purificados se usaron para evaluar la inhibición enzimática “in vitro” en monoaminooxidasas (MAO-A, MAO-B) y aromatasa. Los compuestos presentaron una respuesta positiva calculada con IC50 de hasta 5,47 μM y 1,35 μM para la inhibición de las enzimas MAO-A y aromatasa respectivamente, abriendo el camino a una nueva propuesta de relacionar estas dos enzimas para tratamiento de cánceres hormonodependientes y transtornos de ansiedad y depresión.
8

Identifica??o de inibidores oriundos de fontes naturais para o modelo do receptor atpase-ca+2 do Plasmodium falciparum (PfATP6)

Santos, Elis?ngela 10 September 2014 (has links)
Submitted by Verena Bastos (verena@uefs.br) on 2015-07-27T21:52:27Z No. of bitstreams: 1 60-elisangela-dissertacao-completa-10-09-2014.pdf: 1880962 bytes, checksum: b1c3f3312f451d624f7c2186af20b453 (MD5) / Made available in DSpace on 2015-07-27T21:52:27Z (GMT). No. of bitstreams: 1 60-elisangela-dissertacao-completa-10-09-2014.pdf: 1880962 bytes, checksum: b1c3f3312f451d624f7c2186af20b453 (MD5) Previous issue date: 2014-09-10 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Malaria is considered a non-contagious chronic evolution with episodic manifestations of acute character infectious disease, which afflicts millions of people in tropical and subtropical areas of the world. Vegetables represent a source of active molecules for various diseases, including malaria. Through phytochemical procedures, one can study the secondary metabolism of these plants where they hope to find new sources of treatment for malaria. The present study had as main objective to identify molecules derived from natural sources can inhibit the ATPase-Ca 2 + protein of Plasmodium falciparum (PfATP6). The molecular target was the model PfATP6 receiver, obtained by comparative modeling. Was performed using the program AutoDock Vina 1.1.2. screening in databases with the aim of selecting the 10 most promising ligands, with determination of the energies of affinity. Subsequently, tests with hydromethanolic and chloroform extracts of the species of Tul Cenostigma macrophyllum were performed. The patterns of agatisflavona and amentoflavone biflavonoids were analyzed by High Performance Liquid Chromatography for Detection Arrangement Diodes (HPLC-DAD) to identify the presence of these metabolites in the species. Validation of the chromatographic method took into account the parameters selectivity, linearity, precision, accuracy, limit of detection and limit of quantification. The results showed molecular next coupling energy variation among the 10 selected compounds (1 kcal / mol). With the results of the molecular coupling of the intermolecular interactions were studied and agatisflavona amentoflavone with PfATP6 receiver comparing them with the values obtained for thapsigargin. Since the energy values affinity the compounds amentoflavone -10.0 kcal / mol and agatisflavona -9.7 kcal / mol ortost?rico showed affinity for the receptor site of PfATP6, these interactions being supported by the nature of intermolecular interactions identified. By comparing the retention times and ultraviolet spectra (UV) of the standards and samples could be identified agatisflavona amentoflavone and biflavonoids the leaves and stem bark of C. macrophyllum. Quantification of agatisflavona biflavonoide ranged from 22.25 to 0.012 mg of agatisflavona / g dry plant and amentoflavone ranged from 20.63 to 0.02 mg of amentoflavone / g dry plant. The analysis of the parameters evaluated showed that the method was suitable for the analysis of agatisflavona and amentoflavone, performing in line with the specifications of the current legislation. It is noticed that the amentoflavone agatisflavona compounds and can act in PfATP6 receiver, directing further studies of interactions in biological target in perspective for malaria control. Thus, it is possible to suggest that there are natural compounds present in semiarid with possible antimalarial activity, wherein the molecular modeling tool associated with the phytochemical analysis can guide the identification of bioactive compounds, and therefore the development of new drugs. / A mal?ria ? considerada como uma doen?a infecciosa, n?o contagiosa de evolu??o cr?nica com manifesta??es epis?dicas de car?ter agudo, a qual aflige milh?es de pessoas nas zonas tropicais e subtropicais do globo. Os vegetais representam fonte de mol?culas ativas para diversas enfermidades, incluindo a mal?ria. Atrav?s de procedimentos fitoqu?micos, pode-se estudar o metabolismo secund?rio desses vegetais onde se esperam encontrar novas fontes de tratamento para a mal?ria. O presente estudo teve como objetivo geral identificar mol?culas oriundas de fontes naturais capazes de inibir a prote?na ATPase-Ca+2 do Plasmodium falciparum (PfATP6). O alvo molecular foi o modelo do receptor PfATP6, obtido por modelagem comparativa. Foi realizado atrav?s do programa AutoDock Vina 1.1.2. uma triagem em bancos de dados com o objetivo de selecionar os 10 ligantes mais promissores, com determina??o das energias de afinidade. Posteriormente, foram realizados testes com os extratos hidrometan?lico e clorof?rmico da esp?cie de Cenostigma macrophyllum Tul. Os padr?es dos biflavonoides agatisflavona e amentoflavona foram analisados por Cromatografia L?quida de Alta Efici?ncia por Detec??o de Arranjo de Diodos (CLAE-DAD) para identifica??o da presen?a destes metab?litos na esp?cie. A valida??o do m?todo cromatogr?fico levou em considera??o os par?metros seletividade, linearidade, precis?o, exatid?o, limite de detec??o e limite de quantifica??o. Os resultados de acoplamento molecular apresentaram varia??o energ?tica pr?xima entre os 10 compostos selecionados (1 kcal/mol). De posse dos resultados do acoplamento molecular foram estudadas as intera??es intermoleculares da agatisflavona e amentoflavona com o receptor PfATP6 comparando-os com os valores obtidos para a tapsigargina. Dado os valores de energia de afinidade, os compostos amentoflavona -10,0 Kcal/mol e agatisflavona -9,7 Kcal/mol apresentaram afinidade com o s?tio ortost?rico do receptor PfATP6, sendo essas intera??es sustentadas pela natureza das intera??es intermoleculares identificadas. Atrav?s da compara??o dos tempos de reten??o e espectros de Ultra Violeta (UV) dos padr?es e amostras foi poss?vel identificar os biflavonoides agatisflavona e amentoflavona nas folhas e casca do caule de C. macrophyllum. A quantifica??o do biflavonoide agatisflavona variou de 22,25 a 0,012 ?g de agatisflavona/g de planta seca e da amentoflavona variou de 20,63 a 0,02 ?g de amentoflavona/g de planta seca. A an?lise dos par?metros avaliados demonstrou que o m?todo foi adequado para a an?lise da agatisflavona e amentoflavona, apresentando-se em conson?ncia com as especifica??es da legisla??o vigente. Percebe-se que os compostos amentoflavona e agatisflavona podem atuar no receptor PfATP6, direcionando novos estudos de intera??es nesse alvo biol?gico na perspectiva de controle da mal?ria. Desta forma ? poss?vel sugerir que existem compostos naturais presente no semi?rido com poss?vel atividade antimal?rica, no qual a ferramenta da modelagem molecular associada ?s analises fitoqu?micas pode guiar na identifica??o de compostos bioativos e, por conseguinte no desenvolvimento de novos f?rmacos.
9

Contribuição ao estudo químico e avaliação da atividade antioxidante dos frutos verdes de Clusia paralicola (Clusiaceae)

FERREIRA, Rafaela Oliveira 13 July 2011 (has links)
Submitted by (lucia.rodrigues@ufrpe.br) on 2017-02-15T14:32:16Z No. of bitstreams: 1 Rafaela Oliveira Ferreira.pdf: 3340061 bytes, checksum: d21a202a067991aeff9b03f826465dbd (MD5) / Made available in DSpace on 2017-02-15T14:32:16Z (GMT). No. of bitstreams: 1 Rafaela Oliveira Ferreira.pdf: 3340061 bytes, checksum: d21a202a067991aeff9b03f826465dbd (MD5) Previous issue date: 2011-07-13 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Clusia paralicola (Clusiaceae) occurrs in forests from northeastern Brazil, especially in the semi-arid and wet forests, is popularly known as pororoca. This work describes the chemical and antioxidant activity of the green fruits from Clusia paralicola G. Mariz Cunha and resulted in the isolation and identification of two biflavonoids (GB1-7"-Oglucoside and 3,8 '-binaringenin-7"-O-β-glucoside), a catechin (epicatechin), two steroids (β-sitosterol and stigmasterol), a phenylpropanoid (1,3,5-trimethoxy-2- propenilbenzen) and a triterpene (β-amyrin). The structures of isolated compounds were elucidated by analysis of NMR spectra of ¹H and ¹³C, including 2D and LC-ESI-MS The absolute stereochemistry of biflavonoids was determined by circular dichroism analysis and complete structural elucidation was performed to GB1-7-O-glucoside. To determine the total phenolic content was used Folin-Ciocalteu test and to evaluate the antioxidant potential were used DPPH, ABTS and the system β-carotene/ linoleic acid with the EtOH extract and hexane, EtOAc and MeOH/H2O fractions. Evaluation of antioxidant activity was also performed with mixtures of two biflavonoids. For the total phenolic content, antiradicalar activity (DPPH and ABTS) and antioxidant activity with the system β carotene/linoleic acid were more active the EtOH extract and EtOAc fraction. The EtOH extract and fractions tested showed correlation with the total phenolic content and activity antioxidant. With the exception of β-amyrin, previously identified in the latex of C. paralicola, all substances are being reported for the first time in this species. The absolute stereochemistry was determined as (2R, 3S, 2”R, 3”R)-GB1-7-O-glucoside and (2R, 3S, 2”R)-3.8'-binaringenina-7-O-glycoside. These biflavonoids are inedited in the Clusia genus. / Clusia paralicola (Clusiaceae) têm ocorrência nas florestas nordestinas, especialmente do semi-árido e dos brejos de altitude, é conhecida popularmente como pororoca. Este trabalho descreve o estudo químico e a avaliação da atividade antioxidante dos frutos verdes de Clusia paralicola. O estudo químico resultou no isolamento e identificação de dois biflavonóides (GB-1-7”-O-glicosídeo e 3,8”-binaringenina-7”-O-β-glicosídeo), uma catequina (epicatequina), dois esteróides (β-sitosterol e estigmasterol), um fenilpropanóide (1,3,5-trimetoxi-2-propenilbenzeno) e um triterpeno (β-amirina). As estruturas das substâncias isoladas foram elucidadas pelas análises dos espectros de RMN de ¹H e ¹³C, incluindo 2D e LC-ESI-MS. A estereoquímica absoluta dos biflavonoides foi determinada através da análise de dicroismo circular e a elucidação estrutural completa foi realizada com GB1-7-O-glicosídeo. Para a determinação do teor de fenólicos totais foi utilizado o reagente de Folin-Ciocalteu e para avaliar o potencial antioxidante foram realizados os ensaios com DPPH, ABTS e o sistema β- caroteno/ácido linoléico com o extrato EtOHe frações hexânica, AcOEt e MeOH/H2O. A avaliação da atividade antioxidante foi realizada também com a mistura dos biflavonoides. Para o teor de fenólicos totais, atividade antiradicalar (ABTS e DPPH) e atividade antioxidante com o sistema β-caroteno/ácido linoléico foram mais ativos o extrato EtOH e a fração AcOEt. O extrato EtOH e frações testadas apresentaram correlação com o teor de fenólicos totais e atividade antioxidante. Com exceção da β- amirina, previamente identificada no látex de C. paralicola, todas as substâncias estão sendo relatadas pela primeira vez nesta espécie. A esteroquímica absoluta foi determinada como sendo (2R, 3S, 2”R, 3”R)- GB1-7-O-glicosídeo e (2R, 3S, 2”R)-3,8”- binaringenina-7-O-glicosídeo. Estes biflavonóides são inéditos no gênero Clusia.
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Estudo químico e avaliação biológica do extrato das cascas das raízes de Caesalpinia pyramidalis Tul (Leguminosae)

Oliveira, José Cândido Selva de January 2010 (has links)
74 f. / Submitted by Ana Hilda Fonseca (anahilda@ufba.br) on 2013-04-08T15:15:32Z No. of bitstreams: 1 Dissertação_JC Selva.pdf: 822691 bytes, checksum: e44864a244534144b43291b347e46945 (MD5) / Approved for entry into archive by Ana Hilda Fonseca(anahilda@ufba.br) on 2013-05-09T17:19:25Z (GMT) No. of bitstreams: 1 Dissertação_JC Selva.pdf: 822691 bytes, checksum: e44864a244534144b43291b347e46945 (MD5) / Made available in DSpace on 2013-05-09T17:19:25Z (GMT). No. of bitstreams: 1 Dissertação_JC Selva.pdf: 822691 bytes, checksum: e44864a244534144b43291b347e46945 (MD5) Previous issue date: 2010 / CAPES / O presente trabalho relata o estudo químico das cascas das raízes de Caesalpinia pyramidalis Tul., uma árvore pertencente a família Leguminosae endêmica da região da caatinga baiana cujas folhas são utilizadas na medicina popular como diurético e digestivo. O extrato metanólico bruto foi submetido à extração liquido-liquido e sua atividade citotóxica e antioxidante foram avaliadas. O extrato hexânico apresentou-se atóxico para o teste de letalidade de Artemia salina e os demais extratos foram moderadamente tóxicos. Em relação à atividade antioxidante, o extrato AcOEt foi o mais ativo, seguido do BuOH e MeOH. O fracionamento cromatográfico da fase hexânica permitiu o isolamento do lupeol, acacetina, um novo fenilpropanóide, ácido (E)-8-hidroxi-3,5-dimetoxicumarico, além de uma mistura de sitosterol e estigmasterol. Da fase metanólica foram isolados o mesmo fenilpropanóide encontrado na hexânica além de um novo biflavonóide, 7-hidroxi-4’-metoxiflavona-5α-2,4- dihidroxi-4’-metoxidihidrochalcona. A estrutura deste novo biflavonóide bem como das outras substâncias isoladas foram elucidadas a partir da análise dos dados de RMN 1H e 13C (BB e APT) juntamente com a RMN de correlação (HMQC e HMBC). / Salvador

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