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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

Estudo quÃmico e biolÃgico de Croton regelianus var. matosii (Euphobiaceae) / Chemical and biological study of Croton regelianus var. Matosii (Euphobiaceae)

Maria da ConceiÃÃo de Menezes TÃrres 14 February 2008 (has links)
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / Este trabalho descreve a investigaÃÃo fitoquÃmica de Croton regelianus (Euphorbiaceae), visando o isolamento e caracterizaÃÃo estrutural de novos constituintes quÃmicos com potencial farmacolÃgico, bem como a investigaÃÃo da composiÃÃo quÃmica dos Ãleos essenciais e avaliaÃÃo de seu potencial biolÃgico. O estudo dos Ãleos essenciais das folhas de C. regelianus resultou na identificaÃÃo de 20 constituintes, correspondendo a mais de 98% da composiÃÃo de cada Ãleo, ambos constituÃdos exclusivamente por monoterpenos. O Ãleo essencial e o ascaridol, componente majoritÃrio, mostraram significante atividade frente Ãs larvas do Aedes aegypti e Artemia sp, e moderada atividade nematostÃtica contra ao fitonematÃide Meloidogyne incognita. Ambos, Ãleo essencial e ascaridol, tambÃm exibiram potente atividade anticancer. A investigaÃÃo quÃmica realizada com os extratos hexÃnico e etanÃlico das folhas e talos da referida espÃcie resultou no isolamento e caracterizaÃÃo de dez substÃncias. Do extrato hexÃnico das folhas foram isolados o triacontanol, fitol, -sitosterol, (3R, 4R, 6S)-3,6-dihidroxi-1-menteno, enquanto do extrato etanÃlico foi isolado o glicosÃdeo do -sitosterol. Do extrato hexÃnico dos talos isolou-se uma mistura dos esterÃides 6b-hidroxi-campest-4-en-3-ona e 6b-hidroxiestigmast-4-en-3-ona, alÃm de (4aS,8aS,)-4,4a,8a,9,10,10a-hexahidro-8a-hydroxi-1,1,4a,7-tetrametilfenantreno-2,6(1H,3H,)-diona. Do extrato etanÃlico obteve-se o sesquiterpeno 1a-hidroximetil-6b-hidroxi-4a-metil-7b-(1-metiletil)-4b,11b-epoxi-decahidroazuleno e a cumarina cleomiscosina A. A determinaÃÃo estrutural das substÃncias foi realizada atravÃs do uso de tÃcnicas espectromÃtricas como: infravermelho (IV), espectrometria de massa (EM e EM-IES) e ressonÃncia magnÃtica nuclear de hidrogÃnio (RMN 1H) e carbono-13 (RMN 13C), incluindo tÃcnicas bidimensionais (COSY, HSQC, HMBC, NOESY) e comparaÃÃo com dados descritos na literatura, enquanto a composiÃÃo quÃmica dos Ãleos essenciais estudados foi determinada por CG-EM e CG-DIC. O potencial citotÃxico das substancias isoladas foi avaliado frente Ãs linhagens de cÃlulas tumorais humanas: cÃlon (HCT8), mana (MDA-MB-435), leucemia (HL60) e cÃrebro (SF295), porÃm nÃo apresentaram atividade citotÃxica. / This work describes the phytochemical investigation of Croton regelianus (Euphorbiaceae), with the purpose to isolate and characterize new bioactive secondary metabolites, as well as, to investigate the chemical composition of the leaf essential oils and to evaluate its biological potential. The study of the leaf essential oils from samples collected at two different geographical sites resulted in the identification of 20 components. More than 98% of the chemical composition, exclusively monoterpenes, of each oil was determined. The essential oil and its major component, ascaridole, showed potent activity against the Aedes aegypti and Artemia sp larvae and moderate activity against the nematode Meloidogyne incognita. Both, the essential oil and ascaridole also exhibited potent anticancer activity. The phytochemical investigation of hexane and ethanol extracts from leaves and branch of C. regelianus conducted to the isolation and characterization of ten substances. From the hexane extract of the leaves were isolated triacontanol, phytol, b-sitosterol and (3R, 4R, 6S)-3,6-dihydroxy-1-menthene, while from ethanol extract were isolated the b-sitosterol glycoside. From the hexane extract of branch were isolated the steroidal mixture 6b-hydroxy-campest-4-en-3-one and 6b-hydroxyestigmast-4-en-3-one, and the (4aS,8aS,)-4,4a,8a,9,10,10a-hexahydro-8a-hydroxy-1,1,4a,7-tetramethylphenanthrene-2,6(1H,3H,)-dione. From the ethanol extract was obtained the sesquiterpene 1a-hydroxymethyl-6b-hydroxy-4a-methyl-7b-(1-methylethyl)-4b,11b-epoxy-decahydroazulene and the coumarin cleomiscosine A. The structure of all compounds were elucidated by spectroscopic methods, such as IR, LREIMS, HRESIMS, 1H and 13C NMR, and by comparison with published data for closely related compounds. Even though the cytotoxic properties of all compounds have been tested no one showed any activity.
2

Phytochemical study of Macroptilium lathyroides (L.) Urb. (FABACEAE) / Estudo fitoquÃmico de Macroptilium lathyroides (L.) Urb (FABACEAE)

LeÃncio Mesquita de Sousa 22 July 2011 (has links)
FundaÃÃo de Amparo à Pesquisa do Estado do Cearà / Uma das prÃticas mais antigas no tratamento e na cura das enfermidades à sem dÃvida nenhuma, o uso dos produtos naturais, especialmente, os de origem vegetal. Atà o sÃculo XIX, os recursos terapÃuticos eram predominantemente constituÃdos pela utilizaÃÃo de partes das plantas e extratos vegetais. Com o avanÃo dos instrumentos cientÃficos e tecnolÃgicos se estabeleceu a tendÃncia de utilizaÃÃo das substÃncias ativas presentes nas plantas. Realizou-se a inve stigaÃÃo fitoquÃmica dos galhos e talos e das raÃzes de Macroptilium lathyroides. Esta espÃcie està inserida na subfamÃlia Papilionoideae da famÃlia Fabaceae. Do extrato em hexano dos talos e galhos foi isolada a mistura dos esterÃides sitosterol e estigmasterol (ML-1). Do extrato em hexano das raÃzes foram isolados a lasiodiplodina (ML-2) e a mistura dos esterÃides 6β-hidroxi-estigmast-4-en-3-ona e 6 β - hidroxi-estigmast-4,22-dien-3-ona (ML-3) e do extrato em acetato de etila das raÃzes foram isolados de-O-metil-lasiodiplodina (ML-4) e 4',5,7-triidroxiisoflavona (ML-5). Os compostos isolados foram identificados atravÃs dos mÃtodos espectroscÃpicos (IV, EM, RMN 1 H e RMN 13C), incluindo tÃcnicas bidimensionais (H MBC, HSQC e COSY) e comparaÃÃo com dados da literatura. Os extratos obtidos foram avaliados quanto à atividade larvicida sobre Aedes aegypti, mostrando-se, portanto, inativos. Este à o primeiro relato do estudo fitoquÃmico de Macroptilium lathyroides, bem como da investigaÃÃo da atividade larvicida dos extratos obtidos. / One of the oldest practices in the treatment a nd cure of diseases is undoubtedly the use of natural products, especially those of vegetable origin. Until the nineteenth century, the therapeutic resources were predominantly constituted by the use of plant parts and plant extracts. With the advancement of scientific and technological instruments that set the trend for the use of active substances in plants. In this work we present the phytochemical investigation of the branches and stems, and roots of Macroptilium lathyroides. This species is placed in the subfamily Papilionoideae of the Fabaceae family. The mixture of steroids sitosterol and stigmasterol (ML-1) was isolated from hexane extract of stems and branches. Lasiodiplodina (ML-2) and the mixture of steroid 6 β -hydroxy-4-stigmasta en-3-one and 6 β - hydroxy-4-stigmasta 4,22-dien-3-one (ML -3) were isolated from hexane extract of the roots and from the ethyl acetate extract of the roots were isolated de-O-methyl-lasiodiplodina (ML-4) and 4 ',5,7-triidroxiisoflavona (ML-5). The isolated compounds were identified by spectroscopic methods (IR, MS, 1H and 13C NMR), including two-dimensional techniques (HMBC, HSQC, COSY), and comparison with spectral data in the literature. The extracts were evaluated for larvicidal activity against Aedes aegypti, showing, therefore, inactive. This is the first report on the phytochemical study of Macroptilium lathyroides, as well as research larvicidal activity of the extracts.
3

Constituintes QuÃmicos dos ZoantÃdeos Palythoa caribaeorum (Duchassaing & Michelotti, 1860) e Protopalythoa Variabilis (Duerden, 1898) / Chemical Constituents of the zoanthids Palythoa caribaeorum (Duchassaing & Michelotti, 1860) and Protopalythoa variabilis (Duerden, 1898)

Josà Gustavo Lima de Almeida 24 November 2011 (has links)
nÃo hà / Este trabalho descreve a composiÃÃo quÃmica das espÃcies marinha Palythoa caribaeorum e Protopalythoa variabilis, coletadas no municÃpio de Paracuru-CE. O fracionamento cromatogrÃfico do extrato hexÃnico de P. caribaeorum, resultou no isolamento de quatro esterÃides tetracÃclico de esqueleto ergostano: 24(R)-ergost-5-en-3-ol (P-1); 5,8-epidioxi-24(R)-ergost-6-en-3-ol (P-2); 24(R)-ergost-5-en-3,7-diol (P-4) e 24(R)-7-hidroperoxi-ergost-5-en-3-ol (P-7), um derivado do glicerol, 1-O-hexadecilglicerol (P-3) e quatro ceramidas: N-(2S,3R,4E,8E,1,3-dihidroxi-4,8-octadecadieno)hexadecanamida (P-5); N-(2S,3R,4E,1,3-dihidroxi-4-octadeceno)-hexadecanamida (P-6), N-[2S,3R,4E,8E,1-(2â-metilamino-etanosulfonila)-3-hidroxi-4,8-octadecaÂdieno]hexadecanamida (P-8) e N-[2S,3R,4E,1-(2â-metilaminoetano-sulfonila)-3-hidroxi-4-octadeceno]hexadecanamida (P-9). Do fracionamento cromatogrÃfico do extrato etanÃlico, foi possÃvel isolar o esterÃide 24(R)-ergost-7-en-3,56-triol (P-10) e o nucleosÃdeo 2-metil-timidina (P-11). Do estudo quÃmico do extrato hexÃnico de P. variabilis obteve-se os mesmos constituintes quÃmicos isolados de P. caribaeorum (P-1, P-2, P-3 e P-4) e as quatro ceramidas (P-5, P-6, P-8 e P-9). AlÃm destes compostos foi isolado um Ãster de cadeia alifÃtica, hexadecanoato de nonila (P-12) e o esterÃide Ãcido 24(R)-B-norergostan-3-5-diol-6-carboxÃlico (P-13). O potencial citotÃxico e antifÃngico das ceramidas foi avaliado, entretanto, estas nÃo apresentaram atividade. Os compostos foram isolados atravÃs de cromatografia de adsorÃÃo em gel de sÃlica e cromatografia lÃquida de alta eficiÃncia. As estruturas dos compostos obtidos foram elucidadas utilizando tÃcnicas espectroscÃpicas e espectromÃtricas, tais como: espectrometria de massa acoplada a cromatografia gasosa (CG/EM); espectrometria de massa de alta resoluÃÃo (EMAR); espectroscopia na regiÃo do infravermelho (IV) e RessonÃncia MagnÃtica Nuclear (RMN 1H, 13C e 15N) atravÃs de sequÃncias de pulsos uni e bidimensionais e comparaÃÃo com dados de RMN na literatura. / This work describes the chemical composition of the marine species Palythoa caribaeorum and Protopalythoa variabilis, both collected at Paracuru beach, state of CearÃ. The cromatographic fractionation of the hexane extract from P. caribaeorum resulted in the isolation of four tetracyclic sterols possessing the ergostan skeleton: 24(R)-ergost-5-en-3b-ol (P-1); 5 a,8a-epidioxy-24(R)-ergost-6-en-3b-ol (P-2); 24(R)- ergost-5-en-3b,7a-diol (P-4) and 24(R)-7a-hydroperoxy-ergost-5-en-3b-ol (P-7), a glycerol derivative, 1-O-hexadecylglycerol (P-3) and four ceramides: N- (2S,3R,4E,8E,1,3-dihydroxy-4,8-octadecadienyl)hexadecanamide (P-5); N- (2S,3R,4E,1,3-dihydroxy-4-octadecenyl)hexadecanamide (P-6); N-[2S,3R,4E,8E,1-(2â- methylamino-ethanosulfonyl)-3-hydroxy-4,8-octadecaenyl]hexadecanamide (P-8) and N-[2S,3R,4E,1-(2â-methylaminoethano-sulfonyl)-3-hydroxy-4-octadecenyl]hexadecanamide (P-9). The cromatographic fractionation of the ethanol extract permited the isolation of a steroid, 24(R)-ergost-7-en-3b,5a,6b-triol (P-10) and a nucleoside 2- methyltimidine (P-11). Column chromatography of the hexane extract of P. variabilis led to the isolation of nonyl hexadecanoate (P-12), the sterol 24(R)-B-norergostan-3b- 5b-diol-6b-carboxylic acid (P-13) and the same chemical constituents previously isolated from P. caribaeorum (P-1, P-2, P-3 e P-4) including the four ceramides (P-5, P-6, P-8 e P-9). The citotoxic and antifungal properties of all ceramides were evaluated, nevertheless none of them showed any activity. All compounds were isolated through adsorption column cromatography over silica gel followed by high performance liquid chromatography. The structures of the isolated compounds were elucidated using spectrometric techniques, such as: GC/MS, HRESIMS, IR and NMR (1H, 13C and 15N) through 1D and 2D pulse sequences and, whenever the case, comparison with literature data

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