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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.
11

Study Chemical and Biological Margaritopsis carrascoana Wright (Rubiaceae) / Estudo QuÃmico e BiolÃgico de Margaritopsis carrascoana Wright (Rubiaceae).

Raimundo Regivaldo Gomes do Nascimento 16 December 2014 (has links)
FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / Margaritopsis carrascoana is a small shrub belonging to the Rubiaceae family and endemic from northeastern of Brazil flora growing in the sandy soils of the region of Ibiapaba and Araripe plateaus â Cearà state. The absence of reports of phytochemical studies related to this species, combined with occurrence of bioactive alkaloids in the genus, motivated us to perform chemical study. The plant specimen was collected in Araripe plateu, in MoreilÃndia-PE county. The phytochemical investigation of the ethanolic extract from the stems yielded the alkaloids calycosidine, hodgkinsine, N-8â-formyl-calycosidine and N-8â-methyl-N-1â-desmethylisocalycosidine, besides neolignan dihydrodehydrodiconiferyl alcohol 4-O-β-D-glucopyranoside, the flavonol luteolin 7-O-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranosyl, the triterpenes lupeol and ursolic acid, and the mixture of β-sitosterol and stigmasterol steroids, as aglycones and glycosylated. From the ethanolic extract of the leaves were isolated the flavonoid luteolin 7-O-[β-D-apiofuranosyl-(1→6)]-β-D-glucopyranoside, chrysoeriol 7-O-[β-D-apiofuranosyl-(1→6)]-β-D-glucopyranoside, luteolin 7-O-{β-D-apiofuranosyl-(1→6)-[β-L-rhamnopyranosyl-(1→2)]-β-D-glucopyranosyl} and luteolin 7-O-{α-L-rhamnopyranosyl-(1→6)-[β-L-rhamnopyranosyl-(1→2)]-β-D-glucopyranosyl}. The alkaloids N-8"-formyl-calycosidine, N-8â-methyl-N-1â-desmethylisocalycosidine, luteolin 7-O-{β-D-apiofuranosyl-(1→6)-[β-L-rhamnopyranosyl-(1→2)]-β-D-glucopyranosyl} and luteolin 7-O-{α-L-rhamnopyranosyl-(1→6)-[β-L-rhamnopyranosyl-(1→2)]-β-D-glucopyra-nosyl}, are being reported for the first time in the literature, and the other secondary metabolites are unprecedented in the genus Margaritopsis. The secondary metabolites were isolated using classical chromatography techniques; including adsorption chromatography on silica gel, exclusion chromatography on Sephadex LH-20, reverse phase chromatography (C-18), and high performance liquid chromatography (HPLC). For structural characterization were used infrared spectroscopy, mass spectrometry and nuclear magnetic resonance techniques including uni (1H NMR and 13C NMR and DEPT 135) and two-dimensional experiments (HMBC, HSQC, COSY and NOESY), and comparison with the literature data. In addition, the flavonoids flavonol luteolin 7-O-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranosyl, luteolin 7-O-[β-D-apiofuranosyl-(1→6)]-β-D-glucopyranoside, luteolin 7-O-{β-D-apiofuranosyl-(1→6)-[β-L-rhamnopyranosyl-(1→2)]-β-D-glucopyranosyl} and luteolin 7-O-{α-L-rhamnopyranosyl-(1→6)-[β-L-rhamnopyranosyl-(1→2)]-β-D-glucopyranosyl, sho-wed antioxidant activity greater than the BHT and quercetin standards, while ethanol extracts of stems and leaves showed inhibitory activity on the acetylcholinesterase enzyme. On the other hand, hodgkinsine showed potent cytotoxic activity against ovary, glioblastoma and colon cancer cells lines. The ethanol extract of the leaves and its alkaloidal fraction were submitted to nociception test and yielded good results. The ethanolic extract of the leaves was subjected to gastric antiulcer activity test, leading to a significant reduction in gastric lesions induced by ethanol in mice. / Margaritopsis carrascoana à um pequeno arbusto pertencente à famÃlia Rubiaceae e endÃmico da flora do Nordeste brasileiro, que cresce em solos arenosos do planalto da Ibiapaba e serra do Araripe - CearÃ. A ausÃncia de relatos acerca de estudos fitoquÃmicos relacionados à espÃcie, aliada a ocorrÃncia de alcalÃides bioativos no gÃnero, nos motivou ao seu estudo quÃmico. Desta forma, o espÃcimen vegetal foi coletado na chapada do Araripe, municÃpio de MoreilÃndia-PE. A investigaÃÃo fitoquÃmica do extrato etanÃlico dos talos resultou no isolamento dos alcalÃides calicosidina, hodgkinsina, N-8â-formilcalicosidina e N-8â-metil-N-1â-desmetilisocalicosidina, da neolignana Ãlcool 4-O-β-D-glicopiranosil-di-hidro-desidrodiconiferÃlico, do flavonÃide 7-O-[α-L-ramnopiranosil-(1→2)-β-D-glicopiranosil luteolina, dos triterpenos lupeol e o Ãcido ursÃlico, e da mistura de esterÃides β-sitosterol e estigmasterol, como agliconas e nas formas glicosiladas. A partir do estudo do extrato etanÃlico das folhas foram isolados os flavonÃides 7-O-[β-D-glicopiranosil-(1→6)-β-D-apiofuranosil] luteolina, 7-O-[β-D-glicopiranosil-(1→6)-β-D-apiofuranosil] crisoeriol, 7-O-{β-D-apiofuranosil-(1→6)-[α-L-ramnopiranosil-(1→2)-β-D-glicopiranosil} luteolina e 7-O-{α-L-ramnopiranosil - (1→6) - [α-L-ramnopiranosil-(1→2)-β-D-glicopiranosil} luteolina. Os alcalÃides N-8â-formilcalicosidina e N-8â-metil-N-1â-desmetilisocalicosidina, e os flavonÃides 7-O-{β-D-apiofuranosil-(1→6)-[α-L-ramnopiranosil-(1→2)-β-D-glicopiranosil} luteolina e 7-O-{α-L-ramnopiranosil-(1→6)-[α-L-ramnopiranosil-(1→2)-β-D-glicopiranosil} luteolina, estÃo sendo relatados pela primeira vez na literatura, enquanto todas as demais substÃncias possuem carÃter inÃdito no gÃnero Margaritopsis. O isolamento dos metabÃlitos secundÃrios foi conduzido atravÃs de tÃcnicas cromatogrÃficas clÃssicas, incluindo cromatografia de adsorÃÃo em gel de sÃlica, cromatografia por exclusÃo molecular em Sephadex LH-20, cromatografia de fase reversa (C-18) e cromatografia lÃquida de alta eficiÃncia (CLAE). Para a caracterizaÃÃo estrutural foram utilizadas tÃcnicas espectroscÃpicas utilizando infravermelho, espectrometria de massas e ressonÃncia magnÃtica nuclear, incluindo tÃcnicas uni (RMN 1H e RMN 13C e DEPT 135) e bidimensionais (HMBC, HSQC, COSY e NOESY), alÃm de comparaÃÃo com dados descritos na literatura. Em adiÃÃo, os flavonÃides 7-O-[α-L-ramnopiranosil-(1→2)-β-D-glicopiranosil luteolina, 7-O-[β-D-glicopiranosil-(1→6)-β-D-apiofuranosil] luteolina, 7-O-{β-D-apiofuranosil-(1→6)-[α-L-ramnopiranosil-(1→2)-β-D-glicopiranosil} luteolina e 7-O-{α-L-ramnopiranosil-(1→6) - [α-L-ramnopiranosil-(1→2)-β-D-glicopiranosil} luteolina apresentaram atividade antioxidante maior que os padrÃes BHT e quercetina, enquanto os extratos etanÃlicos dos talos e folhas apresentaram atividade inibidora da enzima acetilcolinesterase. Por outro lado, o alcaloide hodgkinsina apresentou potencial citotÃxico frente Ãs cÃlulas de ovÃrio, glioblastoma e colon. No teste de nocicepÃÃo, realizado com o extrato etanÃlico das folhas e a fraÃÃo alcalÃidica, foram observados resultados positivos para ambas as fraÃÃes. O extrato etanÃlico das folhas foi submetido a teste de atividade antiÃlcera gÃstrica, levando a uma reduÃÃo significativa da Ãrea de lesÃo gÃstrica induzida pelo etanol em camundongos.
12

Aspectos quÃmicos do estudo interdisciplinar (quÃmica-agronomia-farmacologia) de Amburana cearensis A.C. Smith / Chemical aspects of the investigations to interdisciplinar (chemistry-agronomy-pharmacology)de Amburana cearensis A. C. Smith

Kirley Marques Canuto 10 August 2007 (has links)
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / Amburana cearensis A.C. Smith (sin. Torresea cearensis Fr. All) à uma Ãrvore tÃpica da caatinga nordestina, popularmente conhecida como imburana-de-cheiro ou cumaru, caracterizada por sua casca vermelho-pardacenta e odor peculiar agradÃvel, atribuÃdo à cumarina. Apresenta relevante importÃncia econÃmica, sobretudo na carpintaria e perfumaria, e inestimÃvel valor medicinal (propriedades terapÃuticas contra afecÃÃes respiratÃrias cientificamente comprovadas), todavia esta espÃcie sofre ameaÃa de extinÃÃo devido ao extrativismo predatÃrio. Em virtude da necessidade de elaboraÃÃo de um modelo de exploraÃÃo auto-sustentÃvel de A. cearensis, foi proposto um estudo integrado QuÃmica-Agronomia-Farmacologia. Este trabalho relata a abordagem fitoquÃmica da pesquisa interdisciplinar, visando o isolamento, a purificaÃÃo e a caracterizaÃÃo estrutural de novos constituintes quÃmicos da planta adulta (silvestre), bem como a identificaÃÃo e a quantificaÃÃo de compostos quÃmicos jà conhecidos, considerados biomarcadores, em espÃcimens jovens de diferentes meses de desenvolvimento (cultivados). As investigaÃÃes quÃmicas da planta silvestre de A. cearensis foram realizadas com os extratos etanÃlicos da casca do caule, coletadas no municÃpio de Quixeramobim-CE, e das sementes, adquiridas no comÃrcio de Fortaleza-CE. Os extratos etanÃlicos foram submetidos a partiÃÃes lÃquido-lÃquido, cromatografias convencionais (adsorÃÃo-gel de sÃlica e exclusÃo- gel de dextrana) e modernas (HPLC-fase reversa), resultando no isolamento e identificaÃÃo de: A. Cumarinas- 6-hidroxi-cumarina e protocatecuato de 6-cumarila; B. Ãcidos fenÃlicos- Ãcido vanÃlico e Ãcido (E)-o-cumÃrico; C. FlavonÃides- quercetina, formononetina, e os biflavonÃides amburanina A e B; AmburosÃdios- amburosÃdio A, ferulato de 6â-amburosila, protocatecuato de 6â-amburosila, galato de 6â-amburosila, acetato de 6â-amburosila, sinapato de 6â-amburosila e vanilato de 6â-amburosila. Os espÃcimens cultivados de A. cearensis, divididos em parte aÃrea e xilopÃdio, foram extraÃdos com etanol e submetidos a uma metodologia quÃmica semelhante à adotada para a planta silvestre. Da parte aÃrea foram obtidos cumarina, aiapina, amburanina B, isocampferÃdio, Ãcido vanÃlico e Ãcido (E)-o-cumÃrico glicosilado, enquanto que do xilopÃdio foram isolados Ãcido p-hidroxi-benzÃico, Ãcido (Z)-o-cumÃrico glicosilado e amburosÃdio B. As substÃncias quÃmicas isoladas tiveram suas estruturas elucidadas por mÃtodos fÃsicos (ponto de fusÃo e rotaÃÃo Ãptica) e espectromÃtricos (Espectrometria na regiÃo do Infravermelho, Espectrometria de Massa e RessonÃncia MagnÃtica Nuclear de 1H e 13C, incluindo tÃcnicas uni e bidimensionais), alÃm de comparaÃÃo com dados da literatura. Os extratos etanÃlicos da planta silvestre (casca do caule) e de espÃcimens cultivados (parte aÃrea e xilopÃdio) foram quimicamente comparados atravÃs de anÃlises por HPLC, empregando-se mÃtodo cromatogrÃfico validado (linearidade, precisÃo, exatidÃo, fator de recuperaÃÃo aceitÃveis) e utilizando-se padrÃes de Ãcido protocatecuico, Ãcido vanÃlico, cumarina e amburosÃdio A, obtidos em estudos anteriores. AmburosÃdio A foi o constituinte majoritÃrio do extrato da planta silvestre. Nos espÃcimens jovens, Ãcido vanÃlico e cumarina revezaram-se como principais componentes, dependendo da parte e da idade da planta estudada. / Amburana cearensis A.C. Smith is a typical tree of the northeastern Brazil flora designated âcaatingaâ. It is popularly known either as âimburana-de-cheiroâ or âcumaruâ and characterized by its red-gray bark of peculiar and pleasant smell due to coumarin. Despite A. cearensis relevant economical (particularly for carpentry and perfumery) and medicinal importance (therapeutic properties against respiratory affections scientifically proved), it is one of the plant species treated of extinction due to predatory extractivism. Taking in account the necessity of elaborating a sustainable plan of exploitation it was suggested an integrated study covering the chemical, agronomical and pharmacological aspects of A. cearensis. This work reports the phytochemical component of the interdisciplinary study pursuing the isolation, purification and structure characterization of new secondary metabolites of the wild adult plant, as well as the identification and quantification of the already known chemicals, considered the plant biomarkers, from young cultivated specimens at different developmental stages. The chemical investigation of adult wild plants was performed with the ethanol extract from barks of A. cearensis collected at Quixeramobim County, Cearà state, and the hexane extract of seeds purchased from herbal stores at Fortaleza. The ethanol extracts were submitted to liquid-liquid partition, conventional (silica gel adsorption and gel exclusion with dextran) and modern (HPLC) chromatography leading to the isolation and characterization of: A. Coumarins 6-hydroxy-coumarin, 6-coumaryl protocatechuate, acid; B. Phenol Acids- vanillic acid, o-coumaric; C. Flavonoids- quercetin, formononetin, amburanin A and B; AmburosÃdes- amburoside A, 6â-amburosyl-ferulate, 6â-amburosyl-protocatechuate, 6â-amburosyl-galate, 6â-amburosyl-acetate, 6â-amburosyl-sinapate and 6â-amburosyl-vanillate. The cultivated specimens, separated in aerial part and xylopode, were extracted with ethanol and submitted to the same methodology employed for the wild plant. From the aerial part were isolated coumarin, ayapin, amburanin B, isokaempferide, vanillic acid, (E)-o-coumaric acid glucoside, while from the xylopode were isolated p-hydroxy-benzoic acid, (Z)-o-coumaric acid glucoside and amburoside B. All chemical substances had their structures elucidated through physical (mp and optical rotation) and spectroscopical methods (IR, MS and NMR, including uni and bidimensional techniques) and comparison to the literature wherever the case. The ethanol extracts from either wild or cultivated (aerial part and xylopode) plants were compared by HPLC through a validated chromatographic method (acceptable linearity, precision, accuracy and recovering factor) using as standard the protocatechuic acid, vanillic acid, coumarin and amburoside A, obtained from the previous studies. Amburoside A was the major component of wild plant, while coumarin and vanilic acid take turns as the principal metabolites of cultivated young plants depending on the plant part and plant age.

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