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No. of bitstreams: 1 clarissacamposbarbosadecastro.pdf: 2254862 bytes, checksum: 1e36ad3e2b75fb1647eeebd43a2ae62c (MD5) Previous issue date: 2013-07-31 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico / FAPEMIG - Fundação de Amparo à Pesquisa do Estado de Minas Gerais / A esquistossomose é uma doença que afeta cerca de 240 milhões de pessoas no mundo e mais de 700 milhões estão expostas ao risco de contraí-la, sendo que no Brasil, o Estado de Minas Gerais é um dos mais afetados com esta parasitose. Atualmente, o único fármaco disponível para o tratamento desta doença é o praziquantel (PZQ). No entanto, este medicamento já está no mercado há décadas e tem demonstrado relatos de ineficácia. Neste contexto, extratos e metabólitos secundários obtidos de espécie do gênero Piper (Piperaceae) têm demonstrado expressiva atividade esquistossomicida. Assim, o presente trabalho descreve o estudo fitoquímico do extrato diclorometânico das inflorescências de Piper aduncum L. (PaI), bem como a avaliação da atividade esquistossomicida in vitro do extrato, frações e dos metabólitos obtidos. No estudo fitoquímico, a fração clorofórmica, obtida do PaI, foi submetida ao fracionamento cromatográfico por meio de colunas de sílica gel, o que culminou no isolamento e identificação de quatro metabólitos: uma diidrochalcona, uma chalcona e duas flavanonas, sendo relatada pela primeira vez a presença da diidrochalcona uvangoletina e da chalcona cardamonina nesta espécie de Piper. No estudo esquistossomicida in vitro foi utilizado vermes adultos de S. mansoni da linhagem BH e os parâmetros avaliados foram mortalidade, motilidade e alterações tegumentares. Os resultados deste estudo demonstraram que o extrato diclorometânico bruto (PaI), na concentração de 200 μg/mL, possui expressiva atividade esquistossomicida in vitro ao ser capaz de causar a morte de 100% dos parasitos após 24 h de incubação. Em relação à atividade esquistossomicida das frações obtidas deste extrato, a clorofórmica (200 μg/mL) foi a mais ativa ao provocar a morte de todos os vermes após 48 h, enquanto a fração hexânica, na mesma concentração, só foi capaz de provocar tal efeito após 72 h de incubação. Em contrapartida, a fração em acetato de etila demonstrou-se inativa frente aos parasitos. Dentre as substâncias isoladas da fração clorofórmica, a cardamonia foi a mais ativa ao provocar, na concentração de 25 μM, a morte e lesões tegumentares em 100% dos vermes adultos de S. mansoni em apenas 24 h de incubação. Já uvangoletina demonstrou pouco ativa e a flavanona pinocembrina inativa, ambas testadas na concentração de 100 μM. Os resultados obtidos neste estudo, aliados aos já alcançados pelo nosso grupo de pesquisa, demonstram o grande potencial de chalconas como protótipos para o desenvolvimento de novos fármacos esquistossomicidas. / Schistosomiasis is a disease that affects more than 240 million individuals in the world and 700 million people in the world remain under risk of infection. In Brazil, the Minas Gerais state is one of the most affected by this disease. Nowadays, the only drug available for treatment of disease is praziquantel (PZQ). However, this drug is already on market for decades and has shown ineffectiveness. In this context, extract and secondary metabolites of the genus Piper (Piperaceae) have shown an expressive schistosomicidal activity. Thus, the present work describes the phytochemical study of the dichloromethane extract of Piper aduncum L. (PaI) inflorescences, as well as its in vitro schistosomicidal evaluation and its fractions and metabolites. The phytochemical study, the chloroform fraction, obtained by PaI, was subjected to fractionation using chromatographic on silica gel columns that allowed the isolation and identification of four metabolites: one diidrochalcone, one chalcone and two flavanones, from which the diidrochalcone uvangoletin and the chalcone cardamonin were reported for the first time in this species of Piper. In the in vitro schistosomicidal study, was used adult worms of the S. mansoni BH strain and the parameters evaluated were mortality, motility and alterations tegumental surface. The results this study showed that the crude dichloromethane extract (PaI), at 200 μg/mL, show has expressive schistosomicidal activity being able to cause 100% of death in parasites after 24 h of incubation. Relative schistosomicidal activity of the fractions, chloroform fractions (200 μg/mL) was the most active being able to death of all worms after 48 h , while hexane fractions, at the same concentration, also being able to cause this effect after 72h of incubation. On the other hand, ethyl acetate fractions show inactive. Among pure compounds obtained from chloroform fraction, cardamonin was the most active, being able, at 25 μM, to both kill and cause tegumental alterations in 100% of adult worms of S. mansoni in the first 24 h of incubation. On the other hand, uvangoletin showed weak activity, while flavanone pinocembrin was inactive, both at concentration of 100 μM. The results obtained in this study, combined with those already achieved by our research group, demonstrate the great potential of chalcones as prototypes for the development of new antischistosomal drugs.

M.Tech. / There are over 250 cinnamon species existing worldwide, and amongst them, 2 species Cinnamomum cassia and Cinnamomum zeylanicum, are commonly used all over the world as spices, fragrances in perfumes and as medicines. These two species are distinguished from each other by the presence and absence of certain compounds depending on the origin and distribution of the plant. Nevertheless, all cinnamon species contain essential oils and water soluble components and the composition of these components found in each species depends on the type of species involved. These components are made up of phenyl propanoids, terpenes, flavonoids and saponins. In general, the essential oil component contains the following compounds: cinnamaldehyde as a major constituent with its derivatives cinnamic acid, cinnamyl alcohol, ethyl cinnamate, cinnamyl acetate and 2-methoxy cinnamaldehyde; eugenol; linalool; coumarin; carvone; carvacrol and β-caryophyllene. Most of these compounds are abundantly found in the bark except in the case of eugenol which is found in either leaves or bark depending on the species involved. The other water soluble component is composed of a group of compounds such as tannin, chalcone, catechins and anthocyanidins. These compounds polymerize to form methyl hydroxy chalcone polymers (MHCP) which has been shown to play an important role in lowering blood sugar levels in Type ll diabetic individuals. It is said that MHCP has an ability to promote the phosphorylation process which in turn activates the beta-cells and thereby creating insulin activity that will then convert glucose into glycogen. Besides all health benefits of cinnamon, the plant contains a toxic compound, coumarin which impacts badly on animals resulting in death, and little information on its toxicity to human beings has been documented. Concerns arose about the possible presence of coumarin in these formulations, since these formulations are made from the cinnamon and the plant contains coumarin. This work has investigated the potential toxicity of coumarin from cinnamon powder and cinnamon formulation. The components from both cinnamon samples were extracted using various solvents according to their polarities and these compounds were screened on thin layer chromatography (TLC). The essential oil components were separated by column chromatography, and quantified by using high performance liquid chromatography (HPLC), all components (essential oil and water soluble) were identified by HPLC, and finally the characterization of the essential oil components was done with infrared (IR) and nuclear magnetic resonance (NMR) whereas those of the water soluble were characterized by using liquid chromatography coupled to a mass spectrometer (LC-MS).

In view of the increasing global challenge of bacterial resistance, there exists an urgent need for the rationale development of antibacterial compounds with either novel or multiple mechanisms of action. Two chalcone-derivatives, F1 and F23, demonstrated MICs within the range of 16 to >512 μg/ml against two plant pathogens (P. caratovoram and C. michiganensis subsp. michiganensis) as well as important clinical bacterial species. Both compounds displayed an MIC of 32 μg/ml against quinolone-resistant S. aureus. Whilst possessing weak activities individually, each semi-synthetic agent displayed notable synergistic action with polymyxin B against S. aureus, C. violaceum, E. coli and Ps. aeruginosa, thereby recording FICs within the range of <0.093 to 2 that indicated the existence of synergism in some instance. These chalcone compounds applied with polymyxin B displayed a notable FICindex of <0.093 against the Neisseriaceae C. violaceum, and a potential noteworthy capacity to extend the spectrum of activity of the latter antibiotic to include Gram-positive S. aureus species. F1 inhibited staphylococcal replication in broth and the combination of either of both chalcone-derivatives with polymyxin B instituted a metabolic blockage in S. aureus and other bacterial species as determined through a modified MTT reduction assay. The combined agents inflicted major disruptions to the S. aureus cytoplasmic membrane bilayer as evidenced by the release of intracellular potassium as well as the influx of Sytox Green fluorescent stain. Notable levels of cell membrane potential dissipation, leakage of intracellular potassium ions and blockage of reducing enzymes activities occurred within the first 30 minutes, well in advance of significant loss in cell viability that was recorded usually after 4 – 8 hours, suggesting these activities were prerequisites to cell death. In erythrocyte lysis assay, the synergistic combinations of 128 μg/ml of either of both chalcone derivatives with 128 μg/ml polymyxin B displayed the lowest degree of haemolysis, followed by that occurring with 32 μg/ml of the chalcone-derivatives combined with 256 μg/ml of the polypeptide antibiotic. In conclusion, further structure activity modifications aimed at improving the aqueous solubility of these chalcone-derivatives as well as the antibacterial activity recorded for certain combination concentrations of polymyxin B with either of these semi-synthetic agents may be required before considerations are made for the possibility for potential external formulations. Such preparations may include antiseptic creams, lotions, ointments, as well as aerosols that can be applied with nebulizers in targeted delivery for such cases like cystic fibrosis.

Submitted by Marcos Anselmo (marcos.anselmo@unipampa.edu.br) on 2018-09-24T15:01:09Z No. of bitstreams: 1 CAMILA COELHO RODRIGUES.pdf: 1765480 bytes, checksum: b3f50f8973734acade5a9396b1aafebf (MD5) / Approved for entry into archive by Marcos Anselmo (marcos.anselmo@unipampa.edu.br) on 2018-09-24T15:03:24Z (GMT) No. of bitstreams: 1 CAMILA COELHO RODRIGUES.pdf: 1765480 bytes, checksum: b3f50f8973734acade5a9396b1aafebf (MD5) / Made available in DSpace on 2018-09-24T15:03:24Z (GMT). No. of bitstreams: 1 CAMILA COELHO RODRIGUES.pdf: 1765480 bytes, checksum: b3f50f8973734acade5a9396b1aafebf (MD5) Previous issue date: 2018-07-13 / A apocinina apresenta estrutura pequena e possui diversas atividades biológicas, sua estrutura pode ser oxidada em certas condições e resultar na formação do seu dímero, a diapocinina. Como um potencial agente terapêutico, análogos estruturais da diapocinina, contendo grupos substituintes ligados a esta molécula, podem apresentar atividade neuroprotetora e aceptora de radicais. As chalconas apresentam estrutura química 1,3-diaril-2-propen-1-ona simples que permite variadas modificações estruturais com a finalidade de otimizar o perfil farmacológico ou direcioná-las para diferentes atividades biológicas. A resposta de maior destaque é a capacidade aceptora de radicais e atividade neuroprotetora. Neste trabalho foram realizadas a síntese e caracterização da diapocinina e seus derivados, a avaliação das propriedades físico-químicas e da atividade aceptora de radicais, estudos de modelagem e docking molecular, toxicidade in silico e in vivo, com a finalidade de se obter compostos que possam ser empregados como candidatos a novos fármacos aceptores de radicais e antiparkinsonianos. A diapocinina foi sintetizada a partir da apocinina e caracterizada por CLAE, espectroscopia IV, e RMN 1H e 13C. As chalconas derivadas da diapocinina com substituintes 4-Cl, 4-N(CH3)2, 4-OCH3 e 4-NO2, foram sintetizadas através da condensação de Claisen-Schmidt. A análise de capacidade aceptora de radicais foi realizada através do ensaio de DPPH utilizando como padrão BHT. A análise de toxidade in silico, especificamente o risco de causar genotoxidade, mutagenicidade, efeitos irritante e sobre sistema reprodutor, foi realizado através dos programas computacionais Osiris Property Explorer e admetSAR. Os estudos de docking molecular foram realizados utilizando o software iGemdock 2.1 e envolveu a avaliação de ligação individual da apocinina e diapocinina. Os protocolos experimentais pré-clínicos in vivo de avaliação de atividade frente a sintomas de doença de Parkinson foi realizado com Drosophila melanogaster. A apocinina demonstrou capacidade de captura de DPPH maior que seu dímero, sugerindo-se que este composto se apresenta como melhor candidato para o desenvolvimento de compostos com atividade antioxidante potencial. A partir da análise da toxicidade in silico observou-se que somente os compostos 4-N(CH3)2 e 4-NO2 apresentaram riscos de causar os efeitos mutagênicos e genotóxicos, sendo que os demais compostos apresentaram risco teórico baixo. Os resultados obtidos no estudo de docking molecular permitiram a obtenção de modelos teóricos onde a apocinina e a diapocinina não possuem ligação no mesmo sitio de interação. Assim sugere-se que estruturas químicas possam, de maneira simultânea, atuar no mesmo alvo, mas em sítios adjacentes de interação. A avaliação da atividade frente a sintomas da doença de Parkinson realizada através de ensaio de sobrevivência, toxicidade e comportamento com Drosophila melanogaster constata que tanto a apocinina e diapocinina são compostos promissores para o estudo e o desenvolvimento de agentes para se utilizar na terapêutica, com atividade neuroprotetora. / Apocynin is phenolic compound with a small structure which exhibit diverse pharmacological activities. Aromatic ring structure can be oxidized under enzymatic or in oxidizing medium generating its dimer, diapocinin. Structural analogues of diapocinin are considering a potential therapeutic agent, and depending on substituent moieties attached to this molecule. Chalcones have a simple chemical 1,3-diaryl-2-propen-1-one structure which allows structural modifications aiming the optimization of the broad recognized pharmacological profile or to reach some different biological activities. Oxygen radical acceptor (antioxidant) and neuroprotective are highlighted biological activities observed to these class of compounds and they were studied in this research. In this work, the synthesis and characterization of diapocinin and its chalcone derivatives, the evaluation of physicochemical properties and radical acceptor activity, molecular modeling and docking studies, in silico and in vivo toxicity, and evaluation of Parkinson’s disease in Drosophila melanogaster protocols were performed in order to support the new antioxidant and antiparkinsonian drugs. Diapocinin was synthesized from apocynin and characterized by HPLC, IR spectroscopy, and 1H and 13C NMR. Chalcones derived from diapocinin, with 4-Cl, 4-N(CH3)2, 4-OCH3 and 4-NO2, were synthesized by the condensation of Claisen-Schmidt. Radical acceptor evaluation was performed usign DPPH assay using BHT as standard. In silico toxicity analysis, specifically the risk of causing genotoxicity, mutagenicity, irritant effects and activity on the reproductive system, were performed using Osiris Property Explorer and admetSAR. Molecular docking studies were performed using iGemdock 2.1 software, and this study involved the evaluation of individual binding of apocynin and diapocinin and alfa-synuclein and NADPH oxidase. In vivo preclinical experimental protocols of activity against Parkinson's disease symptoms were performed with Drosophila melanogaster. Apocynin demonstrated higher DPPH radical capture than diapocynin, suggesting that this compound is the best candidate for the development of compounds with potential antioxidant activity. From the analysis of in silico toxicity, it was observed the 4-N(CH3)2 and 4-NO2 compounds presented risks of causing the mutagenic and genotoxic effects, and the other compounds presented low theoretical risk. The results obtained in the molecular docking study allowed the generation of theoretical models which the apocynin and diapocinin not show binding or interactions in the same molecular protein site. Thus, it is suggested that chemical structures may, simultaneously, act on the same target, but in adjacent sites of interaction. The evaluation of activity against Parkinson's disease symptoms performed by survival, toxicity and behavior assays with Drosophila melanogaster suggest the both apocynin and diapocinin are promising compounds for the study and development of agents to be used in therapy, with neuroprotective activity.

A leishmaniose é uma doença tropical negligenciada causada pelo protozoário Leishmania, que afeta 98 países. Aproximadamente 1,2 milhões de casos de leishmaniose cutânea acontecem todo ano. Os fármacos convencionais utilizados para seu tratamento são tóxicos, caros e requerem longos períodos de terapia, por isso neste trabalho propôs-se o uso da terapia fotodinâmica (TFD) com ftalocianina de cloro alumínio (AlClPc) associada a fármacos leishmanicidas (resveratrol, anfotericina B e chalcona CH8) encapsulados em nanocápsulas poliméricas. A TFD vem sendo apresentada como uma alternativa promissora para o tratamento da leishmaniose cutânea e outras doenças de pele. Sendo assim, avaliou-se sua ação fototóxica em linhagem celular de macrófago RAW 264.7. As nanocápsulas carregadas foram preparadas pelo método de nanoprecipitação e caracterizadas pelo tamanho de partícula, índice de polidispersão, potencial zeta, eficiência de encapsulação, estudos espectroscópicos e estabilidade física. As nanocápsulas apresentaram um diâmetro médio de 230 nm, baixa polidispersividade (0,3 de índice de polidispersão) e potencial zeta negativo (cerca de -30 mV). A análise morfológica foi realizada através de microscopia de força atômica, pela qual se comprovou o formato esférico das nanopartículas. A formulação apresentou uma boa eficiência de encapsulação, da ordem de 75%, como esperado para fármacos hidrofóbicos. As nanocápsulas exibiram boa estabilidade física ao longo de um período de 3 meses o que foi comprovado pelos estudos de estabilidade acelerada com um tempo de vida de prateleira de 3-6 meses. O comportamento reológico das formulações foi determinado a partir de medidas de variação de velocidade de rotação. Os estudos de toxicidade na ausência de luz demonstraram o caráter biocompatível das nanocápsulas desenvolvidas. Sob irradiação de luz visível em uma dose máxima de 1,0 J.cm-2, o efeito fototóxico provocado pelas nanocápsulas contendo AlClPc (5 ?M) e AlClPc (5 ?M) associada ao Resveratrol (50 ?M), reduziu a viabilidade celular a 30%, já as nanocápsulas contendo AlClPc (5 ?M) associada a AmB (4 ?M) e AlClPc (5 ?M) associada a chalcona (10 ?M) reduziram a ii sobrevivência celular a uma taxa de 50 % e 10%, respectivamente. AlClPc permaneceu na região citoplasmática das células 24 h após a administração comprovada através de estudos de microscopia de fluorescência. Os resultados obtidos neste trabalho indicam que as nanocápsulas poliméricas se apresentam com potenciais sistemas de administração deste fármaco fotossensibilizador hidrofóbico (AlClPc) associado aos demais fármacos leishmanicidas para tratamento de leishmaniose caracterizado uso de baixas concentrações dos ativos e de baixa dose de luz visível, que levam a respostas biológicas muito boas, incentivando-se assim estudos in vivo posteriores. / Leishmaniasis is a neglected tropical disease caused by the protozoan Leishmania, which affects 98 countries. Approximately 1.2 million cases of cutaneous leishmaniasis occur every year. Conventional drugs used for its treatment are toxic, expensive, and require long periods of therapy, so this work suggested the use of photodynamic therapy (PDT) with aluminum phthalocyanine chloride (AlClPc) associated with leishmanicidal drugs (resveratrol, amphotericin B and chalcone CH8) encapsulated in polymeric nanocapsules. PDT has been shown as a promising alternative for the treatment of cutaneous leishmaniasis and other skin diseases. Therefore, it evaluated its phototoxic effects in cell line RAW 264.7 macrophages. The loaded nanocapsules were prepared by nanoprecipitation method and characterized by particle size, polydispersity index, zeta potential, encapsulation efficiency, spectroscopic data and physical stability. The nanocapsules had an average diameter of 230 nm, low polydispersity (0,3 polydispersity index) and a negative zeta potential (approximately -30 mV). Morphological analysis was performed using atomic force microscopy, in which proved the spherical shape of the nanoparticles. The formulation exhibited good encapsulation efficiency of approximately 75%, as expected for hydrophobic drugs. Nanocapsules exhibited good physical stability over a 3 month period which was confirmed by the accelerated stability studies with a shelf life of 3-6 months. The rheological behavior of the formulations was determined by rotational speed variation.Toxicity studies in the absence of light showed the biocompatible character of the developed nanocapsules. Under visible light irradiation at a maximum dose of 1.0 J.cm-2, the phototoxic effect caused by nanocapsules containing AlClPc (5 ?M) and AlClPc (5 ?M) associated with resveratrol (50 ?M), reduced cell viability to 30%, as nanocapsules containing AlClPc (5 ?M) associated AmB (4 ?M) and AlClPc (5 ?M) associated with chalcone (10 ?M) reduced a cell survival rate of 50% and 10%, respectively. AlClPc remained in the cytoplasmic region of cells 24 h after administration observed by fluorescence iv microscopy studies. The results of this study indicate that polymeric nanocapsules are potential delivery systems of this hydrophobic photosensitizer (AlClPc) drug associated with other leishmanicidal drugs for leishmaniasis treatment with the use of low concentration of assets and low-dose of visible light, encouraging further studies in vivo.

Submitted by Liliane Ferreira (ljuvencia30@gmail.com) on 2018-09-19T14:46:51Z No. of bitstreams: 2 Tese - Rangel Magalhães Luzin - 2018.pdf: 3753425 bytes, checksum: 3ac739156d95f6ef2de370e5c5ce093c (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2018-09-20T11:32:29Z (GMT) No. of bitstreams: 2 Tese - Rangel Magalhães Luzin - 2018.pdf: 3753425 bytes, checksum: 3ac739156d95f6ef2de370e5c5ce093c (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-09-20T11:32:29Z (GMT). No. of bitstreams: 2 Tese - Rangel Magalhães Luzin - 2018.pdf: 3753425 bytes, checksum: 3ac739156d95f6ef2de370e5c5ce093c (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-08-29 / It is known that sun exposure is one of the factors that contribute greatly to the appearance of skin cancer. Cancer cases have arisen annually on the planet and many of these cases have direct correlation with sun exposure. Knowing that both UVA and UVB radiation are harmful to health when the person is overexposed, the need arises for the use of devices to protect the skin and one of these ways and already recognized by the scientific community is through the prophylactic use of protectors solar power. Thus, this work proposes the synthesis, structural characterization, thermal stability verification, molar absorptivity calculation and in vitro UVB protection factor (PFUVB) calculated by the spectrophotometric method described by Mansur of new compounds derived from structures analogous to natural products. The structural planning was based on triazine derivatives (they are already commercially used with relative efficiency) and the use of chalcones, which are structures that besides having double bonds and conjugated aromatic structures that favor the absorption of the ultraviolet radiation, are studied compounds for various purposes and present in various plants, thus constituting a natural structure. In the planning, the choice of such structures was also due to the synthesis of compounds of high molar mass (above 900 daltons), contributing to safe structures, with low toxicity probability, low skin permeation and in compliance with the demands of the current legislation. The data obtained in the work reinforce the success of the same, where we had for the prototypes synthesized, molar absorptions superior to commercial filters. Establishing a​​research with the use of chalcones in safe and efficient sunscreens. / É sabido que a exposição solar é um dos fatores de grande contribuição para o surgimento do câncer. Casos de câncer tem surgido anualmente no planeta e muitos desses casos tem direta correlação com a exposição solar. Sabendo que tanto a radiação UVA quanto a UVB são nocivas à saúde quando o indivíduo é exposto em demasia, surge a necessidade do uso de artifícios para a proteção da pele e uma dessas maneiras e já reconhecida pelo meio científico é através do uso profilático de protetores solares. Assim este trabalho se propôs a síntese, caracterização estrutural, verificação de estabilidade térmica, cálculo de absortividade molar e fator de proteção solar UVB (FPUVB) in vitro calculado pelo método espectrofotométrico descrito por Mansur de novos compostos derivados de estruturas análogas a produtos naturais. O planejamento estrutural foi baseado nos derivados triazínicos (pois já são de uso comercial com relativa eficiência) e o uso de chalconas, que são estruturas que além de possuir duplas ligações e estruturas aromáticas conjugadas que favorecem a absorção da radiação ultravioleta, são compostos bastante estudados para diversos fins e presente em vários vegetais, constituindo assim uma estrutura natural. No planejamento, a escolha de tais estruturas se deu também pela síntese de compostos de alta massa molar (acima de 900 Daltons), contribuindo para estruturas seguras, com probabilidade de baixa toxicidade, baixa permeação cutânea e atendendo aos reclames das legislações vigentes. Os dados obtidos no trabalho reforçam o sucesso do mesmo, onde tivemos para os protótipos sintetizados, absorções molares superiores a filtros comerciais. Estabelecendo assim uma nova linha de pesquisas com a utilização de chalconas em filtros solares seguros e eficientes.

No description available.

Dans le but de rechercher des inhibiteurs naturels des protéines anti-Apoptotiques Bcl-XL et Mcl-1, deux essais biologiques ont été mis au point sur Bcl-XL/Bak-CF et Mcl-1/Bid-CF. Ces deux tests utilisent la polarisation de fluorescence et sont basés sur la liaison d’un peptide pro-Apoptotique marqué à la fluorescéine (Bak-CF ou Bid-CF) avec une protéine anti-Apoptotique (Bcl-XL ou Mcl-1). Au total, près de 600 extraits de pantes, provenant de diverses régions du monde, ont été criblés sur les deux protéines Bcl-XL et Mcl-1 permettant de sélectionner les extraits acétate d’éthyle des écorces de Knema hookeriana (Myristicaceae) et de Fissistigma latifolium (Annonaceae). L’analyse chimique des constituants des écorces de K. hookeriana a conduit à l’isolement de 12 lipides phénoliques dont 6 n’avaient jamais été isolés d’un organisme vivant. Seuls les acides anacardiques ont révélé de très fortes inhibitions de l’interaction Bcl-XL/Bak-CF et Mcl-1/Bid-CF dans les essais par polarisation de fluorescence. Une étude plus approfondie des interactions entre le plus actif des produits et les protéines (Bcl-XL, Mcl-1, Bak et Bid) par RMN, a montré que la modulation des interactions Bcl-XL/Bak et Mcl-1/Bid n’est pas liée à l’affinité de l’acide anacardique pour les protéines Bcl-XL et Mcl-1 mais a une forte affinité pour les peptides Bid et Bak. Le fractionnement bioguidé de l’extrait AcOEt des écorces de F. latifolium a conduit à l’isolement d’une nouvelle chalcone prénylée, la (±)-Écarlottone possédant une dual activité sur les protéines, Bcl-XL et Mcl-1. Par la suite, le fractionnement "RMN-Guidé" a mené à l’isolement de 6 analogues. / In order to search for natural inhibitors of anti-Apoptotic protein Bcl-XL and Mcl-1, two bioassays were developed on Bcl-XL/Bak-CF and Mcl-1/Bid-CF. Both assays use fluorescent polarisation, and are based on binding of a fluorescein labeled pro-Apoptotic peptide (Bak-CF or-CF Bid) with an anti-Apoptotic protein (Bcl-XL or Mcl-1). Nearly 600 extracts from various parts of the world were screened on both Bcl-XL and Mcl-1 proteins to select the ethyl acetate bark extracts of Knema hookeriana (Myristicaceae) and Fissistigma latifolium (Annonaceae). The chemical analysis of the constituents of K. hookeriana has led to the isolation of 12 phenolic lipids. 6 of them were never isolated from a living organism. Only anacardic acids showed very strong inhibition of the interaction Bcl-XL/Bak-CF and Mcl-1/Bid-CF in fluorescent polarisation assays. Further study of the interactions between the most active anacardic acid and proteins (Bcl-XL, Mcl-1, Bak and Bid) by NMR showed that the modulation of Bcl-XL/Bak and Mcl-1/Bid is not related to the affinity of the compoun to the anti-Apoptotic proteins, Bcl-XL and Mcl-1 but to its affinity for peptides, Bid and Bak. The bioguided fractionation of the AcOEt bark extract of F. latifolium led to the isolation of a novel prenylated chalcone, (±)-Écarlottone having a dual activity on protein, Bcl-XL and Mcl-1. Subsequently, fractionation "NMR-Guided" led to the isolation of 6 new analogs.

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / The present work evaluated the cytoprotective effect of chalcone-enriched fraction (CEF) and 2-methyl-inositol (MIT) in primary rat mesencephalic cell culture exposed to the neurotoxin 6-hydroxydopamine (6-OHDA). The CEF was obtained from Myracrodruon urundeuva, a Brazilian medicinal plant used as an antiinflamatory and wound healing agent.in female genital tract. In this fraction there are the dimerics chalcones urundeuvinas A, B e C The other compound was the MIT isolated from Magonia glabrata, a plant popularly known as âTingui de Bolaâ, which bark from its root is used as poison to catch the fishes from lakes and rivers. The immunohistochemical assay for tyrosine hydroxylase revealed that the percentage of dopaminergic cells in our cultures is approximately 2%. After exposition to 6-OHDA (40 and 200 microM) the cellular viability was reduced to 88,81% and 35,45% respectively. The mitochondrial activity was reduced to 88,8 and 35,4%, the nitrite levels was increased to 551,9% and 721,3% respectively and the lipid peroxidation was increased to 166,84% in the concentration of 200 microM, as observed in the MTT, nitrite and TBARS assays respectively. The results show that the exposition to CEF (100 microg/mL) before 6-OHDA (neuroprevention experiment) or after 6-OHDA (neurorescue experiment) reduced significantly the cell death caused by 6-OHDA (40 e 200 microM). The CEF prevented significantly the increase in nitrite levels induced by 6-OHDA (40 and 200 microM) (in both experiments), except in the neurorescue experiment in which the CEF failed to revert the increase in nitrite levels generated by 6-OHDA (200 microM). The CEF inhibited the lipid peroxidation induced by 6-OHDA (200 microM) in both experiments, and also showed antiapoptotic activity against 6-OHDA (40 and 200 microM) in both experiments. The MIT protected significantly TH- and TH+ cells from injury induced by 6-OHDA (40 and 200 microM) in both experiments. It showed a reduction in the nitrite levels generated by 6-OHDA in both experiments. The MIT also reverted the lipid peroxidation generated by 6-OHDA (200 microM) and showed antiapoptotic activity against 6-OHDA (40 and 200 microM) in both experiments. These results suggest that the neuroprotective action these compounds, CEF and MIT are due to antioxidant, besides a possible mitochondrial protection of these polyphenols. In related to MIT not must be discarded the idea of a second messenger action through the production of inositol triphosphate and protein kinase C activation. The findings may have a clinical importance in neurodegenerative conditions like Parkinsonâs disease / No presente trabalho, estudou-se o efeito citoprotetor da fraÃÃo enriquecida de chalconas (FEC) e do 2-O-metilinositol (MIT) em cultura primÃria de cÃlulas mesencefÃlicas de ratos expostas à neurotoxina 6-hidroxidopamina (6-OHDA). A FEC foi isolada de Myracrodruoun urundeuva, planta medicinal brasileira comumente utilizada como antiinflamatÃrio do trato genital feminino. Nesta fraÃÃo estÃo presentes as chalconas dimÃricas urundeuvinas A, B e C. Outro composto estudado foi o MIT, isolado de Magonia glabrata, uma planta popularmente conhecida como âTingui de Bolaâ, cujas cascas de suas raÃzes sÃo usadas como âvenenoâ para facilitar a pesca nos lagos e rios. O MIT à um monossacarideo com um Ãnico anel da estrutura poli-hidroxilada. Apesar de relatos da toxicidade desta planta, o composto estudado nÃo apresentou toxicidade. As cÃlulas foram cultivadas durante quatro dias e apÃs este tempo foram prÃ-incubadas com FEC ou MIT trÃs horas antes (Protocolo de neuroprevenÃÃo) ou trÃs horas apÃs (Protocolo de neuroresgate) a adiÃÃo da 6-OHDA. A imunohistoquÃmica para tirosina hidroxilase revelou um percentual de cÃlulas dopaminÃrgicas em torno de 2%. A 6-OHDA (40 e 200 microM), promoveu uma diminuiÃÃo na viabilidade celular em torno de 37,65% e 63,44% para cÃlulas nÃo dopaminÃrgicas (TH-) e (79,78% e 93,75%) para cÃlulas dopaminÃrgicas (TH+) e aumentou os nÃveis de nitrito para 551,9% e 721,3% respectivamente em relaÃÃo ao controle. AlÃm disso induziu uma grande peroxidaÃÃo lipÃdica (aumento de 166,84%) como observados pelos ensaios MTT, nitrito e TBARS, respectivamente. Na concentraÃÃo de 200microM a 6-OHDA induziu uma grande morte celular, com aumento de cÃlulas em apoptose tardia e necrose. Os resultados mostraram que a FEC (1; 10 e 100 microg/mL) reduziu significativamente e de maneira dose-dependente (p menor igual a0,05) a morte celular induzida pela 6-OHDA (40 e 200 microM). AlÃm disso preveniu o aumento de nitrito e a peroxidaÃÃo lipÃdica. A FEC demonstrou atividade antiapoptÃtica e preveniu a necrose causada pela 6-OHDA (200 microM) (nos dois Protocolos estudados). O MIT (1, 10 e 100 microg/mL) protegeu tanto as cÃlulas TH- quanto TH+ do dano induzido pela 6-OHDA (40 e 200microM) (em ambos os Protocolos), reduzindo os nÃveis de nitrito e a peroxidaÃÃo lÃpidica. TambÃm demonstrou uma potente atividade antiapoptÃtica. Estes resultados demonstram que a neuroproteÃÃo dos compostos estudados, FEC e MIT, se deva as aÃÃes antioxidante, alÃm de uma proteÃÃo a nÃvel mitocondrial destes polifenois, no caso do MIT tambÃm nÃo se podendo descartar uma aÃÃo a nÃvel de segundo mensageiro, via formaÃÃo de inositol trifosfato e ativaÃÃo de PKC. Os achados podem ter uma futura importÃncia clÃnica em doenÃas neurodegenerativas tais como na DoenÃa de Parkinson