Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2016-10-13T18:50:52Z No. of bitstreams: 1 2015 - Vitor Sueth Santiago.pdf: 10611307 bytes, checksum: 28bcb538332e756e608d3f04694b22b6 (MD5) / Made available in DSpace on 2016-10-13T18:50:52Z (GMT). No. of bitstreams: 1 2015 - Vitor Sueth Santiago.pdf: 10611307 bytes, checksum: 28bcb538332e756e608d3f04694b22b6 (MD5) Previous issue date: 2015-10-16 / CAPES / FAPERJ / CAPES-PROCAD / This work aimed to characterize the trypanocidal activity of curcumin, as well as synthesise a set of structurally-related compounds to investigate the relationships between chemical structure and biological activity (SAR). The isolation of natural curcumin was carried along with two other natural curcuminoides, which together with a third (cyclocurcumin) formed the very first set of derivatives subjected to a screening against epimastigotes forms of T. cruzi (Dm28c strain). This screening pointed out the 1,3-diketone moiety as well as the methoxyl- group in the position 3 of the aromatic ring as potencial pharmacophores. Then, a set of synthetic analogues were prepared based on rational changes on the three structural subunits present in curcumin. These synthetic derivatives were subjected to the same screening, and three of them showed superior trypanocidal activity compared to the natural product. Then, taking the informations obtained from this first screening, the synthesis of constrained analogues were performed which showed an interesting result based on the ring-size of the derivatives. In parallel, a series of 1,3-pyrimidine derivatives were prepared, based on potential bioisosteric relationships between the 1,3-diketone moiety and the 1,3-pyrimidine heterocycle. All the derivatives obtained were tested against T. cruzi, and those shown trypanocidal activity were submited to a cell viability assay, where three of the synthetic derivatives demonstrated selective toxicity against the parasite: (E) ? 2 - (4 ? hydroxy - 3-methoxybenzylidene) ? 6 - ((E) ? 3 - (4 ? hydroxy ? 3 - methoxyphenyl) acryloyl) cyclohexanone; (2E,6E) - 2,6 ? bis (4 ? hydroxy ? 3 -methoxybenzylidene) cyclohexanone and 4,4 '- ((1E,1'E) - (2 ? chloropyrimidine - 4,6 - diyl) bis (ethene - 2,1 - diyl)) bis (2 -methoxyphenol). These derivatives were tested in an assay of infected macrophages, and they prove to be toxic for both parasite forms (trypomastigote and amastigote). The investigation of the probable mechanism of action started with a scanning/transmission electronic microscopy of the curcumin-treated parasites in a sublethal dose. The analysis of ultraestructural changes in parasite treated cells suggested the enzyme CYP51 as well as tubulin as possible targets for curcumin. The HPLC analysis of the membrane lipids of treated parasites showed no difference when compared to non treated control. The flow cytometry analysis showed a characteristic profile similar to those compounds who binds to tubulin and disrupts microtubules. To improve this hypothesis, the T. cruzi tubulin was modelled by homology and the curcuminoids were docked at the literature known curcumin site. The results obtained showed a good correlation between the best-scored poses obtained from the docking study and the experimental IC50 values obtained from the assays of the natural derivatives against parasite cells. / Este trabalho teve como principal objetivo a caracteriza??o da atividade tripanocida da curcumina, bem como a s?ntese diversos derivados estruturalmente an?logos a fim de investigar rela??es entre a estrutura qu?mica e a atividade biol?gica. O isolamento da curcumina da matriz natural foi realizado juntamente com outros dois curcuminoides, que em conjunto com um terceiro (ciclocurcumina) formou o primeiro conjunto de compostos submetido a uma triagem biol?gica sobre formas epimastigotas de T. cruzi (cepa Dm28c). Nesta triagem foi detectado como farmac?foro a subunidade 1,3-dicetona e o grupamento metoxila na posi??o 3 do anel arom?tico. Em seguida, foi sintetizada uma cole??o de derivados com modifica??es em tr?s subunidades estruturais da curcumina, os quais foram submetidos a uma triagem frente ao parasito. Tr?s dos an?logos sint?ticos apresentaram atividade t?xica frente ao parasito de maneira superior ao produto natural. Em seguida, usando informa??es da primeira triagem, procedeu-se para a s?ntese de an?logos estruturalmente restritos, os quais apresentaram um importante resultado acerca dos aspectos conformacionais associados ao tamanho do anel utilizado para a restri??o. Em paralelo foi sintetizada uma s?rie de derivados estruturalmente originais explorando a potencial rela??o bioisost?rica entre a subunidade 1,3-dicetona e o anel pirimid?nico. Ap?s triagem de todos os derivados frente a formas epimastigotas de T. cruzi, foi realizado um ensaio de viabilidade celular onde tr?s derivados sint?ticos demonstraram toxicidade seletiva frente ao parasito nas concentra??es testadas: (E) -2- (4-hidr?xi-3-metoxibenzilideno) ? 6 - ((E) ? 3 - (4 - hidr?xi- 3- -metoxifenil) acriloil) cicloexanona, (2E,6E) -2,6-bis (4 ? hidr?xi ? 3 - metoxibenzilideno) cicloexanona e 2-cloro-4,4'- ((1E,1'E) ? pirimidina - 4,6 - diilbis (eteno - 2,1-diil)) bis (2-metoxifenol). Estes derivados foram utilizados em um modelo de macr?fagos infectados, onde provaram ser t?xicos tanto para formas tripomastigotas quanto para formas amastigotas do parasito. Na investiga??o do prov?vel mecanimo de a??o desta classe de compostos, os parasitos tratados com curcumina foram submetidos ? microscopia eletr?nica, onde foram observadas altera??es ultraestruturais no parasito que sugerem como alvos a CYP51 e a tubulina. O ensaio de quantifica??o dos lip?dios n?o-saponific?veis da membrana celular de T. cruzi sugere que n?o houve inibi??o de CYP51, ao passo que a citometria de fluxo das culturas tratadas mostrou um perfil caracter?stico de subst?ncias que atuam sobre os microt?bulos das c?lulas, se ligando ? tubulina. Foi ent?o constru?da por modelagem molecular um modelo de tubulina de T. cruzi onde os curcuminoides naturais ativos foram ancorados, e as pontua??es do ancoramento foram coerentes com os valores de CI50 encontrados.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-02-15T17:02:45Z No. of bitstreams: 1 2009 - William Pereira.pdf: 3794972 bytes, checksum: 64fbf9758bbf44329031caf3b369b79a (MD5) / Made available in DSpace on 2017-02-15T17:02:45Z (GMT). No. of bitstreams: 1 2009 - William Pereira.pdf: 3794972 bytes, checksum: 64fbf9758bbf44329031caf3b369b79a (MD5) Previous issue date: 2009-10-22 / CAPES / The present study has two specific phases: Early, was studied the isathine irradiation with the presence of diisopropil-phosphoril-dimethylidrazone (diisopfh), in chloroform, at room temperature and 300nm. The structure of photo-product was elucidated by GC/MS, IR, NMR 1H, 13C and 31P, as well as hety-cosy, homo-cosy and other techniques. The proposal mechanism involve a bi-radical from triplet excited state of isathine that react with C=N of the diisopfh and has a ring expansion. The successive pass would be thermal and with propanone elimination, as thermal rearrangement on phosphoric derivates described in the literature. In a second phase was studied, by Laser Flash Photolysis, the kinetic effect of the six aromatic derived of phosphoril-hidrazone (H, p-Cl, p-NO2, p-CN, p-NMe2 e p-CO2H) on the triplet excited state of four aromatic ketones: Xanthone, Tioxanthone, Benzophenone and Benzyl. The observed process to quencher, in all cases, was energy transference, because the rate constants are in the order of 1010M-1s-1. In this form was possible to estimate the energy of triplet excited state of these six phosphoril-hidrazone derivates. / O presente estudo divide-se em duas etapas bem distintas: Inicialmente, estudou-se a irradia??o de isatina na presen?a de diisopropil-dimetilfosforilidrazona (diisopfh) em clorof?rmio, a temperatura ambiente e comprimento de onda de 300nm. H? forma??o de um produto majorit?rio cujo peso molecular corresponde ? soma dos reagentes, diminu?do de 58g/mol. A estrutura deste produto foi elucidada por CG/EM, IV e RMN de 1H, 13C e 31P, al?m de t?cnicas como homocosy, hetycosy e outros. Prop?e-se um mecanismo via bi-radical formado a partir do estado excitado triplete da isatina com a liga??o C=N do composto diisopfh e conseq?ente expans?o do anel isat?nico; levando ? forma??o de um prov?vel produto fotoqu?mico prim?rio resultante de cicloadi??o. Numa segunda etapa, por processo t?rmico de elimina??o de propanona, similar a processo descrito na literatura por Olah, levaria a forma??o do fotoproduto detectado (derivado fosforil-benzodiazep?nico). Numa segunda etapa, estudou-se, por Fot?lise por Pulso de laser, o efeito cin?tico da presen?a de seis derivados arom?ticos de fosforilidrazona (H, p-Cl, p-NO2, p-CN, p-N (CH3)2 e p-CO2H) sobre o estado excitado triplete de quatro cetonas arom?ticas: tioxantona, xantona, benzofenona e benzil, todos em solu??o de acetonitrila. As constantes de velocidades obtidas (da ordem de difus?o da acetonitrila 1,9x1010 M-1s-1) indicam que o processo de supress?o de estado excitado se faz por transfer?ncia de energia. Desta forma foi poss?vel estimar a energia de estado excitado triplete destes derivados arom?ticos de fosforilidrazona.

Submitted by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-02-19T13:03:28Z No. of bitstreams: 5 crisley.pdf: 2081607 bytes, checksum: 90ca0fb9cd507118e713cc82f093637a (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-02-20T09:27:10Z (GMT) No. of bitstreams: 5 crisley.pdf: 2081607 bytes, checksum: 90ca0fb9cd507118e713cc82f093637a (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5) / Made available in DSpace on 2015-02-20T09:27:10Z (GMT). No. of bitstreams: 5 crisley.pdf: 2081607 bytes, checksum: 90ca0fb9cd507118e713cc82f093637a (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5) Previous issue date: 2013-12-17 / A busca por energias alternativas, sustent?veis e economicamente vi?veis, colocou em destaque o uso dos biocombust?veis. Os estudos recentes apontam o uso de biomassas residuais como candidatas potenciais para produ??o de bioenergia. Nesse contexto, a presente disserta??o teve por objetivo ava-liar a torta de dend? como insumo para produ??o de etanol de segunda gera??o por meio de estudos que envolveram etapas de pr?-tratamento ?cido e alcalino, sacarifica??o e fermenta??o. Inicialmente foi determinada a composi??o centesimal da torta de dend?, indicando a presen?a de 53,2% de car-boidratos totais, dos quais 32% referente a fra??o de celulose. Para otimiza??o do pr?-tratamento ?cido foi aplicado um Planejamento Fatorial atrav?s de delineamento composto central rotacional. O programa STATISTICA Vers?o 8.0 (Statsoft Inc., Tulsa,) foi utilizado para an?lise dos dados. O pr?-tratamento com ?cido sulf?rico dilu?do resultou na remo??o de pelo menos 82% da hemicelulose presente na torta de dend?. O pr?-tratamento alcalino subsequente foi capaz de remover pelo menos 72% da lignina da biomassa, um interferente do processo fermentativo. Na sequ?ncia o processo de sacarifica??o foi otimizado com o uso de delineamento composto central rotacional com 3 fatores, 4 pontos centrais e 6 pontos axiais, onde foram avaliadas a concentra??o de celulases, a raz?o s?lido-l?quido e o tempo. O hidrolisado enzim?tico obtido em condi??o otimizada, com 80% de convers?o da celulose a a??cares redutores, foi submetido ? fermenta??o com Saccharomyces cerevisiae apre-sentando um YP/S de 0,49 com 5,4%(v/v) de ?lcool no mosto fermentado. Os dados obtidos indicaram que a torta de dend? avaliada apresenta elevado potencial para produ??o de bioetanol de segunda gera??o. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Qu?mica, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2013. / ABSTRACT The search for alternative energies, sustainable and economically viable, highlighted the use of biofuels. Recent studies indicate the use of residual biomass as potential candidates for bioenergy production. In this context, the present dissertation aimed at evaluating the palm cake as a feedstock for the production of second generation ethanol through studies involving acid and alkaline pretreatment steps, saccharification and fermentation. Initially it was determined the chemical composition of palm cake, indicating the presence of 53.2% of total carbohydrates, of which 32% related to cellulose. To optimize the pretreatment was applied a Factorial Design by central composite rotational design. The program STATISTICA version 8.0 (Statsoft Inc., Tulsa,) was used for data analysis. Pretreatment with dilute sulfuric acid resulted in the removal of at least 82% of the hemicellulose present in palm cake. The subsequent alkaline pretreatment was able to remove at least 72% of the lignin from the biomass, an interfering of fermentation. Further the saccharification process was optimized by the use of central composite design with three factors, fourth central points and six axial points, evaluating the concentration of cellulase, the solid-liquid ratio and the time. The enzymatic hydrolyzate obtained under optimized conditions with 80% conversion of cellulose to sugars was subjected to fermentation with Saccharomyces cerevisiae showing an YP/S of 0.49 based on 5.4% (v/v) of alcohol in the fermented must. The data indicated that the palm kernel cake evaluated presents high potential for production of second generation bioethanol.

Submitted by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-02-19T13:34:45Z No. of bitstreams: 5 fab.pdf: 3600092 bytes, checksum: 62e73afe3033394e17b7ea0fbf24fbf8 (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-02-20T10:44:39Z (GMT) No. of bitstreams: 5 fab.pdf: 3600092 bytes, checksum: 62e73afe3033394e17b7ea0fbf24fbf8 (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5) / Made available in DSpace on 2015-02-20T10:44:39Z (GMT). No. of bitstreams: 5 fab.pdf: 3600092 bytes, checksum: 62e73afe3033394e17b7ea0fbf24fbf8 (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5) Previous issue date: 2013-02-20 / Eletrodos perme?veis a fluidos (EPF) foram confeccionados mediante a eletrodeposi??o do di?xido de chumbo (PbO2) sobre substratos constitu?dos de tecido de carbono (TC) do tipo sarja empregando-se diferentes condi??es experimentais. Foi investigada a influ?ncia dos diferentes tipos de pr?-tratamento do TC na eletross?ntese dos filmes de PbO2. Os substratos pr?-tratados foram caracterizados empregando-se a t?cnica de voltametria c?clica (VC), enquanto que os filmes de PbO2 suportados sobre o TC pr?-tratado foram caracterizados pelas t?cnicas de difratometria de raios-X (DRX), microscopia ?tica (MO), microscopia eletr?nica de varredura (MEV), e a voltametria. Foi verificado que o pr?-tratamento do TC empegando-se o isopropanol ? o mais apropriado para a eletross?ntese dos filmes de PbO2 visando a obten??o de um EPF. O estudo de caracteriza??o ?ex-situ? (DRX, MO e MEV) revelou que as condi??es experimentais mais satisfat?rias para a forma??o da fase ?-PbO2 sobre o TC pr?-tratado, de modo a se obter um EPF, s?o: pH ? 2; 40 oC ? T < 70 oC, e 40 mA cm-2. O comportamento eletroqu?mico do EPF (TC/?-PbO2) foi investigado na condi??o de ?zero-gap? empregando-se a membrana Nafion? 117 (DuPont) como eletr?lito s?lido e a ?gua destilada como fase l?quida. A an?lise das curvas de polariza??o registradas em condi??es quase-estacion?rias para o processo eletr?dico misto da rea??o de desprendimento de oxig?nio (RDO) acompanhada pela rea??o de forma??o de oz?nio (RFO) revelou a presen?a de duas inclina??es de Tafel distribu?das nos dom?nios dos baixos e dos altos sobrepotenciais. Foi obtido um valor de 16 kJ mol-1 para a entalpia de ativa??o aparente determinada no dom?nio dos elevados sobrepotenciais. O estudo envolvendo a quantifica??o do oz?nio produzido com o anodo do tipo TC/?-PbO2 empregando-se um prot?tipo de reator do tipo filtro-prensa revelou que este tipo de EPF n?o ? adequado para o processo da produ??o eletroqu?mica de oz?nio. Entretanto, a grande estabilidade qu?mica e mec?nica apresentada pelo TC/?-PbO2 aliada ao seu grande sobrepotencial para o processo da RDO permite inferir que reatores do tipo filtro-prensa empregando-se este tipo de anodo s?o bastante promissores para processos de interesse ambiental envolvendo a combust?o de poluentes org?nicos presentes em ?guas. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Qu?mica, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2011. / ABSTRACT Electrodes permeable to fluids (EPF) were fabricated by electrodeposition of lead dioxide (PbO2) on substrates made of twill type woven carbon (TC) using different experimental conditions. There has been investigated the influence of the different types of pre-treatment on TC in the electrosynthesis of PbO2 films. The pretreated substrates were characterized using the technique of cyclic voltammetry (VC), while the PbO2 films supported on pre-treated TC were characterized by the techniques of X-ray diffraction (DRX), optical microscopy (MO), scanning electron microscopy (MEV) and voltammetry. It was observed that the pre-treatment of TC using isopropanol is the most suitable electrosynthesis of PbO2 films for obtaining an EPF. The characterization study "ex-situ" (DRX, MO e MEV)) revealed that the experimental conditions more suitable for the formation of phase ?-PbO2 on the TC pre-treated in order to obtain an EPF, are pH ? 2; 40 oC ? T < 70 oC, e 40 mA cm-2. The electrochemical behavior of EPF (TC/?-PbO2) was investigated in the condition of "zero-gap" employing the Nafion? 117 membrane (DuPont) as solid electrolyte and distilled water as the liquid phase. The analysis of polarization curves recorded in quasi-stationary conditions for the mix electrode process of from the mixture of oxygen detachment reaction (RDO) accompanied by the reaction of ozone formation (RFO) has revealed the presence of two Tafel slopes distributed in the areas of low and high overpotentials. There was obtained a value of 16 kJ mol-1 for the apparent activation enthalpy determined in the field of high overpotentials. The study involving the measurement of ozone produced in the anode-type TC/?-PbO2 employing a prototype reactor of the filter-press revealed that this type of EPF is not suitable for the process of electrochemical production of ozone. However, the high chemical and mechanical stability provided by the TC/?-PbO2 combined with its large overpotential for the process of RDO allows to infer that reactors of filter-press employing this type of anode are very promising for processes of environmental interest involving the combustion of organic pollutants in waste water.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-07-12T19:09:00Z No. of bitstreams: 1 2015 - Daiana de Fatima Portella Franco.pdf: 10785257 bytes, checksum: 88b5e7659327980d96446ec26df23a79 (MD5) / Made available in DSpace on 2017-07-12T19:09:00Z (GMT). No. of bitstreams: 1 2015 - Daiana de Fatima Portella Franco.pdf: 10785257 bytes, checksum: 88b5e7659327980d96446ec26df23a79 (MD5) Previous issue date: 2015-08-27 / CAPES / CNPq / FAPERJ / Cancer is a generic term related to more than 100 types of diseases which resemble each other by their disorganized cellular growth. HSP90 are ATP-dependent chaperones responsible for the activation and stabilization of more than 200 proteins. Most of these proteins are connected to cancer and need HSP90 to execute their activities. Thus, HSP90 inhibitors may indirect inhibit plenty oncogenic proteins. According to the literature, there are N-terminal and C-terminal domains, nevertheless, C-terminal inhibitors present more advantages. Then, the advancement of C-terminal inhibitors represents an applicable alternative and an intense field of study. Novobiocin is the first compound identified as C-terminal domain inhibitor. Nowadays, Novobiocin analogues have been synthesized, besides its structure-activity relationship elucidated in order to develop more potents analogues. For that reason, the goal of this project is to obtain 2 analogue series of Novobiocin. The scheme of these series was based on maintaining the coumaniric part presented on Novobiocin: isosteric replacement of the amide group that binds coumarin to the 4-hydroxy-3-(3-methylbut-2-yl)-benzamide, by the [1,2,3]-triazole; and exploration of methyl groups (AN1) and hydroxyl (AN2) in substitution of subunit noviose. AN1 series (76a-g) and AN2 (77a-g) were synthesized from the followed reactions: 7-hydroxy-coumarine o-methylation (83); 7-methoxy-coumarine 3-bromation (82); Sonogashira cross-coupling from 3-bromo-7-R-coumarine (81a-b); 7-R-3-((trimethylsilyl)ethynyl-coumarine trimethylsilyl deprotection (88a-b); and lastly, synthesis of the triazole ring, through cicloaddition reaction, 1,3-dipolar catalysed by copper (CuAAc), using 3-ethynyl-7-R-coumarine (80a-b) and aromatic azides. It is worth taking into consideration that 3-bromo-7-R-coumarine (81b) was obtained from the key compound, 3-bromo-7-R-methoxy-coumarine (81a) by o-demethylation reaction. 12 compounds were obtained (76a-g) and 8 of them (76a-b, 77d) were nicely purified and then, characterized by spectroscopic techniques (IR, 1H and 13C NMR). The ?one-pot? synthesis of 7-methoxy-3-(1H-1,2,3-triazole-4-phenyl)-coumarine 76b from 88a compound (Yield=86%) was more efficient than the one realized in two steps (global yield=47,2%). Results are potential and satisfactory, moreover there is no citation in any literature about biological activities of the synthesized compounds. Continuing this work, the pure compounds (76a-b, 77d) will be tested on breast cancer cell lines SkBr3 and MCF-7. / O c?ncer ? um termo gen?rico que se refere a um conjunto de mais de 100 tipos de doen?as, as quais se assemelham pelo crescimento celular desordenado. As HSP90 s?o chaperonas ATP-dependente respons?veis pela ativa??o e estabiliza??o de mais de 200 prote?nas. Muitas destas prote?nas s?o relacionadas ao c?ncer e necessitam da HSP90 para exercerem suas atividades. Assim, inibidores da HSP90 s?o promissores, pois possibilitam inibir de maneira indireta v?rias prote?nas oncog?nicas simultaneamente. S?o descritos inibidores dos dom?nios N-terminal e C-terminal, sendo estes mais vantajoso que aqueles. O Novobiocin foi o primeiro composto identificado como inibidor do dom?nio C-terminal da HSP90. Atualmente, diversos an?logos ao Novobiocin tem sido sintetizados, afim de se estabelecer a rela??o estrutura-atividade, objetivando desenvolver an?logos mais potentes. Assim, o objetivo deste trabalho foi obter duas s?ries an?logas ao Novobiocin. O planejamento das s?ries foi baseado na manuten??o do n?cleo cumar?nico presente no Novobiocin; troca isost?rica do grupo amida, que liga a cumarina ao anel 4-hidroxi-3-(3-metillbut-2-il)-benzamida, pelo anel [1,2,3]-triazol; e explora??o de grupos metoxila (AN1) e hidroxila (AN2) em substitui??o ? subunidade noviose. As s?ries AN1 (76a-g) e AN2 (77a-g) foram sintetizadas a partir das rea??es de: O-metila??o da 7-hidroxi-cumarina (83); broma??o da posi??o 3 da 7-met?xi-cumarina (82); rea??o de acoplamento cruzado de Sonogashira, a partir da 3-bromo-7-R-cumarina (81a-b); desprote??o do grupamento trimetilsilila da 7-R-3-((trimetilsilil)etenil)-cumarina (88a-b); e por fim, s?ntese do anel triaz?lico, atrav?s da rea??o de cicloadi??o 1,3-dipolar catalisada por cobre (CuAAc), utilizando 3-etenil-7-R-cumarina (80a-b) e azidas arom?ticas. Vale ressaltar que, a 3-bromo-7-hidr?xi-cumarina (81b) foi obtida a partir do composto chave, 3-bromo-7-met?xi-cumarina (81a) via rea??o de O-demetila??o. Obteve-se 12 compostos (76a-g e 77a-g) sendo que 8 (76a-b, 77d) foram, satisfatoriamente, purificados e, ent?o, caracterizados por t?cnicas espectrosc?picas (IV, RMN H e C). Tamb?m foi constatado que a s?ntese ?one-pot? de 7-metoxi-3-(1H-1,2,3-triazol-4-fenil)-cumarina 76b partir do composto 88a (R=86%) foi mais eficiente que a realizada em duas etapas, desilina??o/CuAAc (Rglobal= 47,2%). Os resultados s?o satisfat?rios e promissores, al?m disso n?o h? na literatura descri??o das atividades biol?gica dos compostos sintetizados. Em continua??o a este trabalho, os compostos puros (76a-b, 77d) ser?o devidamente ensaiados frente a c?lulas das linhagens de c?ncer de mama SkBr3 e MCF-7.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-07-12T19:19:51Z No. of bitstreams: 1 2015 - Matheus Gomes Ferreira.pdf: 3047516 bytes, checksum: 3232f27bdf2c2fd0b3942a410158e76e (MD5) / Made available in DSpace on 2017-07-12T19:19:51Z (GMT). No. of bitstreams: 1 2015 - Matheus Gomes Ferreira.pdf: 3047516 bytes, checksum: 3232f27bdf2c2fd0b3942a410158e76e (MD5) Previous issue date: 2015-07-10 / CAPES / In this work were prepared by coprecipitation and characterized by powder XRD and FTIR compounds of the hydrotalcite type, known as Layered Double Hydroxides (LDH), intercalated with the glyphosate anion (GLYP), and the conditions of preparation and the stoichiometric ratio Mg:Al:GLYP were studied. The best condition observed was under reflux for 30 hours and stoichiometric ratio 2: 1: 1 for Mg+2, Al+3 and GLYP, as indicated by the characteristic bands of LDH intercalated with glyphosate and no other bands present, which could be assigned to other intercalated ions or to free glyphosate. Under those preparation conditions the LDH interlamellar spacing was 0.62 nm, compatible with the intercalation of glyphosate. The controlled release of glyphosate was studied using ion exchange reactions of Layered Double Hydroxides containing glyphosate with an aqueous medium containing carbonate, chloride or nitrate anions. In those cases the glyphosate was quantified spectrophotometrically by Ruhemann's purple method (?max = 570 nm), and the initial releasing rates of 0.65 mg/ml/h (carbonate), 0.14 mg/ml/h (nitrate) and 0.08 mg/ml/h (chloride) were measured. Regarding the XRD patterns of the ion-exchanged products, it was observed that the structure of HDL was maintained, but with the reduction of the interlayer spacing in all cases, having a sufficient size for the anion of the involved ion exchange, but not enough for the presence of GLYP, demonstrating so that the exchange was successful. / Neste trabalho foram preparados por coprecipita??o e caracterizados por DRX de p? e FTIR compostos do tipo hidrotalcita, conhecidos como Hidr?xidos Duplos Lamelares (HDL), intercalados com o ?nion glifosato (GLYP), e foram estudadas as melhores condi??es de prepara??o e a raz?o estequiom?trica Mg:Al:GLYP. A melhor condi??o foi sob refluxo por 30 horas e raz?o estequiom?trica 2:1:1 para Mg+2, Al+3, e GLYP, a partir da observa??o das bandas caracter?sticas no espectro de FTIR de um HDL intercalado com glifosato, sem outras bandas presentes que pudessem ser atribu?das a outros ?ons intercalados ou ao glifosato livre. Nessas condi??es de preparo o espa?amento interlamelar do HDL foi de 0,62 nm, compat?vel com a intercala??o do glifosato. A libera??o controlada do glifosato foi estudada atrav?s de rea??es de troca i?nica dos Hidr?xidos Duplos Lamelares contendo glifosato com um meio aquoso contendo os ?nions carbonato, cloreto ou nitrato. Nestes casos o glifosato foi quantificado espectrofotometricamente pelo m?todo do p?rpura de Ruhemann (?max = 570 nm), e foram obtidas as taxas de libera??o iniciais de 0,65 mg/ml/h para carbonato, 0,08 mg/ml/h para cloreto e 0,14 mg/ml/h para nitrato. Nos difratogramas de raios-X dos produtos das trocas i?nicas, em todos os casos foram observadas a manuten??o da estrutura do HDL e a diminui??o do espa?o interlamelar, de 0,62 nm para valores entre 0,33 e 0,35 nm, tamanho suficiente para o ?nion da troca i?nica envolvido, mas n?o suficiente ainda para a presen?a de GLYP, demonstrando assim que a troca foi bem sucedida.

CAPES / Honey is generally known for its therapeutic value and the determination of its main floral source allows the certification to the consumer the properties related to its origin. Thus, the aim of this work was to evaluate the quality and characterize eleven honeys from Apis mellifera from the state of Rio de Janeiro according to physico-chemical parameters, to phenolics profile, to the antioxidant activity and also through the use of chemonetric analysis applied to 1H NMR data and HPLC-DAD. Two samples of assa peixe, six samples of cambara and three samples of morr?o-de-candeia honeys from diferente regions of Rio de Janeiro were analyzed. The physico-chemical parameters determined were: HMF content and color through a spectrophotometric method, free acidity and pH. The content of free amminoacids was also determined through the c?dmium-ninhydrine together with total proteins via the Bradford method. The antioxidant ability of honeys and their extracts was qualitatively determined through the total phenolics content using the Folin-Denis method. Total flavonoids were determined by the complexation method with aluminium chloride. The quantitative antioxidant activity of honeys was determined by the trapping of the 2,2-diphenyl-1-picryl-hydrazyl (DPPH) radical, by trapping of the ABTS.+ radical and also by the iron reduction method (FRAP). The identification and quantitation of polyphenols in the extracts were done by HPLC-PDA. The use of multivariate analysis for the 1H NMR data and HPLC enabled the distinction of the honeys analyzed in this work. Thus, the use of 1H NMR and HPLC data combined with multivariate analysis may be employed as a new strategy for the fast and non-destructive typification of Brazilian honeys. / No mercado, m?is s?o conhecidos pelo seu poder terap?utico e a designa??o de sua principal fonte floral permite atestar ao consumidor as propriedades de sua origem. Assim, o objetivo deste trabalho foi avaliar a qualidade e caracterizar onze m?is de Apis mellifera provenientes do Estado do Rio de Janeiro, por meio de par?metros f?sico-qu?micos, do perfil de subst?ncias fen?licas, de seus potenciais antioxidantes, al?m de usar m?todos quimiom?tricos aplicados aos dados de RMN de 1H e CLAE-DAD. Para tanto, utilizou-se duas amostras de mel de assa peixe, seis de cambar? e tr?s de morr?o de candeia de diferentes munic?pios do Rio de Janeiro. Os par?metros f?sico-qu?micos avaliados foram: teor de HMF e a cor utilizando m?todo espectrofotom?trico, acidez livre e pH. Al?m dessas determina??es, o conte?do de amino?cidos livre foi avaliado pelo m?todo de c?dmio-ninidrina, e prote?nas totais pelo m?todo de Bradford. A capacidade antioxidante dos m?is e de seus extratos foi avaliada qualitativamente atrav?s do conte?do de fen?licos total pelo m?todo de Folin-Denis, e de flavon?ides total pelo m?todo de complexa??o com cloreto de alum?nio. A quantifica??o do potencial antioxidante foi realizada pela captura do radical 2,2-difenil-1-picril-hidrazil (DPPH), captura do radical livre ABTS.+, al?m do m?todo de redu??o do ?on f?rrico (FRAP). A identifica??o e quantifica??o das subst?ncias polifen?licas dos extratos foi feita por cromatografia l?quida de alta efici?ncia com detector de arranjo de diodos (CLAE-DAD). A aplica??o da an?lise multivariada aos dados de RMN de H e de CLAE-DAD distinguiu os m?is de assa peixe, cambar? e morr?o de candeia produzidos no Estado do Rio de Janeiro. Assim, o uso de RMN de 1H e CLAE-DAD combinado com a quimiometria pode ser uma nova estrat?gia para tipifica??o de m?is brasileiros de forma r?pida e n?o destrutiva.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-05-10T19:35:53Z No. of bitstreams: 1 2016 - Julio Eduardo Paiva Sena Maia.pdf: 4252378 bytes, checksum: c4558d5e8e37e740e16bcf9b41d1c55b (MD5) / Made available in DSpace on 2017-05-10T19:35:53Z (GMT). No. of bitstreams: 1 2016 - Julio Eduardo Paiva Sena Maia.pdf: 4252378 bytes, checksum: c4558d5e8e37e740e16bcf9b41d1c55b (MD5) Previous issue date: 2016-06-10 / Laser flash photolysis (LFP) studies have been performed in order to investigate the triplet reactivity toward hydrogen and electron donors of the benzo-fused furan psoralens 3-ethoxycarbonyl-2H-benzofuro[2,3-e]-1-benzopyran-2-one (1) and 3-ethoxycarbonyl-2H-benzofuro[3,2-d]-1-benzopyran-2-one (2). Photolysis of the psoralens 1 and 2 results in the formation of the corresponding triplet excited state which is efficiently quenched by DABCO, triethylamine and phenols containing polar substituents. The reaction of the triplet state of 1 and 2 with electron donors (DABCO and triethylamine) leads to the formation of the corresponding anion radical whereas with phenols the corresponding aryloxyl radical was easily detected. Quenching rate constants for psoralen 2 are at least one order of magnitude greater than for 1. The Hammett plot for the reaction of 1 and 2 with phenols yielded a reaction constant ? of - 1.88?0.29 and -1.60?0.21, respectively, which reflects the high electrophilicity of the carbonyl group of both psoralens. / Estudos empregando a t?cnica de Fot?lise por Pulso de Laser foram realizados a fim de investigar a reatividade dos estados excitados triplete dos benzopsoralenos 3-etoxicarbonil-2-H-benzofuro[2,3-e]-1-benzopiran-2-ona (Pso 1) e 3-etoxicarbonil-2-H-benzofuro[3,2-d]-1-benzopiran-2-ona (Pso 2) frente a doadores de el?tron e hidrog?nio. A fot?lise dos psoralenos Pso 1 e Pso 2 resulta na forma??o do estado excitado triplete correspondente os quais reagem de forma eficiente com DABCO, trietilamina, fenol e seus derivados contendo substituintes polares. A rea??o dos estados excitados triplete de Pso 1 e Pso 2 com doadores de el?tron (DABCO e trietilamina) levou ? forma??o do ?nion radical correspondente, enquanto que na presen?a de doadores de hidrog?nio como o fenol e seus derivados houve forma??o dos radicais fenoxila correspondentes. As constantes de velocidade obtidos para Pso 2 s?o pelo menos uma ordem de grandeza maior do que as obtidas para Pso 1. Um gr?fico de Hammett para as rea??es do triplete de Pso 1 e Pso 2 frente a fen?is e seus derivados produziu constante de rea??o (?? de - 1,88?0,29 e de -1,60 ? 0,21, respectivamente, o que reflete a alta eletrofilicidade do grupo carbon?lico para ambos os benzopsoralenos.

Submitted by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-02-19T13:34:44Z No. of bitstreams: 5 ale.pdf: 2255523 bytes, checksum: 7080bc1f5ac0e98cef0030c1f04a51b3 (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-02-20T10:24:21Z (GMT) No. of bitstreams: 5 ale.pdf: 2255523 bytes, checksum: 7080bc1f5ac0e98cef0030c1f04a51b3 (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5) / Made available in DSpace on 2015-02-20T10:24:21Z (GMT). No. of bitstreams: 5 ale.pdf: 2255523 bytes, checksum: 7080bc1f5ac0e98cef0030c1f04a51b3 (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5) Previous issue date: 2013-02-21 / Na atualidade, n?o se pode desconsiderar a necessidade de desenvolvimento de tecnologias que suportem as demandas por energias renov?veis. Uma das vias para a produ??o de energia renov?vel ? a transforma??o de biomassas vegetais em combust?veis l?quidos. Os res?duos agroindustriais s?o candidatos potenciais como insumos para essa nova ind?stria de energia. Dessa forma a presente disserta??o teve por objetivo avaliar o potencial da torta de caro?o de algod?o e do baga?o de malte com farinha de pupunha como mat?rias-primas para a produ??o de etanol de segunda gera??o e otimizar etapa de pr?-tratamento ?cido do material lignocelul?sico necess?ria para a utiliza??o da celulose. Inicialmente foi determinada a composi??o centesimal da torta de caro?o de algod?o e do baga?o de malte em rela??o aos valores percentuais de umidade, cinzas, extrato et?reo, prote?na bruta, a??cares sol?veis totais, amido, hemicelulose, celulose, lignina, fibra em detergente neutro e fibra em detergente ?cido. Com os resultados da caracteriza??o qu?mica p?de-se estimar uma produ??o potencial superior a 300 L de etanol/tonelada de cada res?duo. Para a otimiza??o do pr?-tratamento ?cido para remo??o da fra??o hemicelul?sica foi aplicada metodologia de Planejamento Fatorial atrav?s de Delineamento Composto Central Rotacional. O programa STATISTICA Vers?o 8.0 (Statsoft Inc., Tulsa,) foi utilizado para an?lise dos dados. A qualidade do ajuste da equa??o do modelo foi expressa pelo coeficiente de determina??o (R?) e sua signific?ncia estat?stica condicionada pelo teste-F. O material insol?vel recuperado ap?s o pr?-tratamento otimizado teve as fra??es hemicelul?sicas e de amido completamente removidas. O hidrolisado obtido em condi??es otimizadas de pr?-tratamento apresentou 15,7% de a??cares redutores para o baga?o de malte e pupunha e 5,9% de a??cares redutores para a torta de caro?o de algod?o. O tratamento dos hidrolisados com carv?o ativado removeu n?o menos que 58% dos compostos fen?licos a? presentes. Os testes de fermentabilidade com Saccharomyces cerevisiae e Pichia stipitis foram promissores. A fermenta??o com S. cerevisiae apresentou um YP/S de 0,30 para a torta de caro?o de algod?o e 0,37 para o baga?o de malte. Os rendimentos fementativos com P. stipitis variaram de 9% a 25% para os res?duos agroindustriais. Os dados experimentais indicam que a torta de caro?o de algod?o (Gossypium hirsutum L.) e baga?o malte com farinha de pupunha tem elevado potencial para a produ??o de bioetanol. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Qu?mica, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2012. / ABSTRACT Nowadays, one cannot ignore the need for developing technologies that support the demands for renewable energy. One of the pathways for production of renewable energy is the transformation of vegetal biomass to liquid fuels. The agro-industrial residues as raw materials are potential candidates for this new energy industry. Thus the aim of the present dissertation was to evaluate the potential of cottonseed cake and crushed malt with peach palm flour as raw materials for the production of second generation ethanol and optimize step of acid pretreatment of lignocellulosic material. Initially was determined the chemical composition of cotton seed cake and crushed malt in relation to the percentages of moisture, ash, ether extract, crude protein, total soluble sugars, starch, hemicellulose, cellulose, lignin, neutral detergent fiber and acid detergent fiber. With the results of chemical characterization it was possible to estimate a potential yield of more than 300L of ethanol / ton of each residue. For the optimization of acid pretreatment for hemicelluloses removal was applied a Central Composite Design. The software STATISTICA Version 8.0 (Statsoft Inc., Tulsa,) was used for data analysis. The goodness of fit of the model equation was expressed by the coefficient of determination (R?) and its statistical significance conditioned by F-test. The insoluble material recovered after the optimized pretreatment had starch and hemicellulose fractions completely removed. The hydrolyzate obtained under optimized conditions of pretreatment showed 15.7% of reducing sugars to the crushed malt and 5.9% of reducing sugars for cottonseed cake. The treatment of the hydrolysates with activated charcoal removed no less than 58% of the phenolic compounds present there. Fermentability tests with Saccharomyces cerevisiae and Pichia stipitis have been promising. Fermentation with S. cerevisiae showed a YP/S of 0.30 for cottonseed cake and 0.37 for the crushed malt. Fermentative yields with P. stipitis ranged from 9% to 25% for agro-industrial residues. The experimental data indicate that the cottonseed cake (Gossypium hirsutum L.) and crushed malt has a high potential for the production of bioethanol.

Submitted by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-02-19T13:34:45Z No. of bitstreams: 5 wil.pdf: 5662404 bytes, checksum: fbb7ee80707ec5b04e9341e471b178d8 (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-02-20T10:42:14Z (GMT) No. of bitstreams: 5 wil.pdf: 5662404 bytes, checksum: fbb7ee80707ec5b04e9341e471b178d8 (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5) / Made available in DSpace on 2015-02-20T10:42:14Z (GMT). No. of bitstreams: 5 wil.pdf: 5662404 bytes, checksum: fbb7ee80707ec5b04e9341e471b178d8 (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5) Previous issue date: 2013-02-20 / O Cerrado apresenta grande diversidade de esp?cies vegetais nativas, muito utilizadas na medicina popular e com pouco ou nenhum estudo cient?fico. Entre essas esp?cies, destaca-se a Blepharocalyx salicifolius (Kunth) O. Berg (Myrtaceae), conhecida como ?Maria-preta?, ?Guamirim? ou ?Murta?. A medicina tradicional recomenda o uso das folhas na forma de infus?o, como antidiarreico, contra infec??es urin?rias e respirat?rias. Estudos evidenciam atividade antimicrobiana do ?leo essencial e leishmanicida do extrato etan?lico das folhas. Estudos fitoqu?micos revelaram a presen?a de compostos fen?licos no extrato e terpenos no ?leo essencial. Geralmente, a constitui??o qu?mica de ?leos essenciais oriundos de um mesmo esp?cimen vegetal e obtidos de plantas de uma mesma esp?cie pode apresentar varia??es qualitativas e quantitativas, em virtude de fatores gen?ticos, ambientais e ontog?nicos. ? importante estudar essas varia??es qu?micas, pois isso pode apresentar implica??es nas atividades biol?gicas de produtos da planta. Al?m disso, tais estudos podem servir para determina??o de marcadores qu?micos ou auxiliar no controle de qualidade do ?leo essencial. Assim, este trabalho teve como principal objetivo observar varia??es qualitativa e quantitativa na composi??o qu?mica do ?leo essencial extra?do de folhas de quatro esp?cimens (BS1, BS2, BS3 e BS4) de B. salicifolius, em tr?s per?odos do dia e nas quatro esta??es do ano. Realizou-se a coleta em habitat natural da esp?cie, na Reserva Guapuruvu da Arcelor Mittal, em Itamarandiba-MG. Procedeu-se a extra??o dos ?leos essenciais de folhas frescas atrav?s de hidrodestila??o em Aparato de Clevenger. Calculou-se o rendimento de cada amostra extra?da (v/m). Efetuou-se a an?lise qualitativa e quantitativa dos componentes dos ?leos essenciais por Cromatografia Gasosa acoplada ? Espectrometria de Massas (CG/EM) e ?ndice de Reten??o Relativa (IRR). O maior rendimento extrativo de ?leo essencial, para todos os esp?cimens, ocorreu no ver?o, e o BS4 foi o que apresentou o maior rendimento m?dio, 0,80% ? 0,12. Verificou-se a ocorr?ncia de varia??es qualitativa e quantitativa dos componentes majorit?rios das amostras analisadas. Assim, houve varia??es qu?micas entre diferentes indiv?duos da esp?cie estudada provenientes de um mesmo habitat, o que pode sugerir diferen?as gen?ticas e/ou ontog?nicas, embora a fase de desenvolvimento fosse semelhante entre os esp?cimens estudados, interferindo no metabolismo secund?rio. Constatou-se, tamb?m, a ocorr?ncia de varia??es qu?micas intraindividuais, sugerindo que as varia??es ambientais (sazonais e circadianas) interferem na composi??o qu?mica dos ?leos essenciais. No entanto, observou-se a presen?a constante, com varia??es quantitativas, de quatro terpenoides (?-pineno, trans-cariofileno, espatulenol e ?-humuleno) em todos os ?leos essenciais analisados. A quantidade de sesquiterpenos identificados sempre foi superior ? de monoterpenos, em todas as amostras. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Qu?mica, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2011. / ABSTRACT The Cerrado comprise great diversity of native vegetal species, widely used in folk medicine although with little or no scientific study. Among these species, stands out Blepharocalyx salicifolius (Kunth) O. Berg (Myrtaceae), known as ?Maria-preta?, ?Guamirim? or ?Murta?. Traditional medicine recommends the use of fresh leaves infusions as antidiarreic, against urinary and respiratory tracts infections. Some studies showed antibiotic activity of essential oil and leishmanicidal activity of ethanolic extract from leaves. Phytochemical studies revealed the presence of phenolic compounds in the extract and terpenes in the essential oil. Generally, the chemical composition of essential oils from the same vegetal specimen and the same species presents quantitative and qualitative variations, due to genetic, environmental and ontogenetic reasons. It is important to study these chemical changes, because this may have implications in the biological activities of plant products. Furthermore, such studies can serve for determination of chemical markers or assist in quality control of essential oil. Thus, this study aimed to observe quantitative and qualitative variations in the chemical composition of essential oil extracted from leaves of four specimens (BS1, BS2, BS3 e BS4) of B. salicifolius, in three period of the day in the four seasons. The leaves were collected on natural habitat of the specie, in Reserva Guapuruvu, Arcelor Mittal, in Itamarandiba-MG. It was proceeded the extraction of essential oils from fresh leaves by hydrodistillation in a Clevenger apparatus. It was calculated the yield of the extracted sample (v/w). The qualitative and quantitative analysis of essential oils compounds were performed by gas chromatography/mass spectrometry (GC/MS) and Relative Retention Index (RRI). The higher yield of essential oil extraction, for all specimens, occurred in the summer and BS4 was presented the highest yield, 0.80% ? 0.12. There was the occurrence of qualitative and quantitative variations of the major components of the samples. Thus, there were chemical variations between different individuals of the species studied from the same habitat, which may suggest genetic differences and/or ontogeny, although the stage of development was similar among the specimens studied by interfering with secondary metabolism. It was found, also, the occurrence of chemical intraindividual variations, suggesting that environmental variations (seasonal and circadian) interfere with the chemical composition of essential oils. However, there was a constant presence, with quantitative variations in all four terpen?ides (?-pinene, trans-caryophyllene, ?-humulene and spathulenol) in essential oils analyzed. The amount of sesquiterpenes identified was always higher than that of monoterpenes in all samples.