This study aimed to calculate physicochemical descriptors for a class of 22 naphtoimidazolic derived compounds that possess microbicidal, bactericidal, fungicidal, trypanocidal activity and so on. The descriptors were also calculated for benznidazole, a drug used in the treatment of Chagas disease and the ravuconazole, which shows itself effective in all strains of the parasite. After calculation of the descriptors found at which of these would be responsible for the separation of compounds into active and inactive. To do so, the structures were pre-optimized through chemical calculations of molecular mechanics and optimized by semi empirical calculations, based on Austin Model 1. After the molecular optimization, multivariate chemometric calculations to make the separation of active and inactive compounds were performed and verify which of descriptors were calculated for separating the relevant class of compounds. Were made 4 chemometric analysis of principal component analysis and hierarchical cluster analysis, where information was available and the similarities of groups formed for the compounds and the descriptors. In the last chemometric analysis it was found that the most active compounds were FSE-1, FSE-2, FSE-13 and FSE-14 and the descriptor responsible for the observed activity would be ELUMO while that would be responsible for the inactivity was AE. Through calculations of the LUMO frontier orbitals, we found that the benzene ring and the imidazole ring are regions in structures that favor the formation of molecular interaction. For benzene of naphthalene, it was observed that the para and ortho positions are also regions of probable formation of molecular interaction. The electrostatic potential maps calculated showed that clusters with concentration of negative charges do not encourage biological activity of naphttimidazolic derivatives. To calculate the molecular anchoring it was used the cruzain enzyme from T. cruzi due its importance in all stages of the parasite life cycle. Realized molecular anchoring it was found that the most relevant interactions are stacking interactions and interactions with the imidazole ring in the ortho and para positions of the naphthalene ring of FSE derivatives. / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Este trabalho teve por objetivo calcular descritores físico-químicos para uma classe de 22 compostos de derivados naftoimidazólicos que possuem atividade microbicida, bactericida, fungicida, tripanocida dentre outras. Os descritores também foram calculados para o benzonidazol, fármaco usado no tratamento da doença de Chagas e para o ravuconazol, fármaco que se mostra efetivo em todas as cepas do parasito. Após o cálculo dos descritores verificou-se quais destes seriam responsáveis pela separação destes compostos em ativos e inativos. Para tanto, as estruturas foram pré-otimizadas através de cálculos químicos da mecânica molecular e otimizadas em cálculos semi-empíricos, na base Austin Model 1. Após a otimização molecular, foram realizados cálculos quimiométricos multivariados para fazer a separação dos compostos em ativos e inativos e, verificar quais dos descritores calculados foram relevantes para a separação da classe de compostos. Foram efetuadas 4 análises quimiométricas de análise de componentes principais e análise hierárquica de agrupamentos, onde foi possível obter informações dos grupamentos e das similaridades formadas para os compostos e para os descritores. Na última análise quimiométrica foi verificado que os compostos mais ativos foram FSE-1, FSE-2, FSE-13 e FSE-14 e que o descritor responsável pela atividade observada seria o ELUMO enquanto que aquele responsável pela inatividade seria o AE. Através dos cálculos dos orbitais de fronteira LUMO, foi possível verificar que o anel benzênico e o anel imidazol são regiões nas estruturas que favorecem a formação de interação molecular. Para o benzeno do naftaleno, observou-se que as posições para e orto, também são regiões de provável formação de interação molecular. Os mapas de potencial eletrostático calculados mostraram que grupamentos com concentração de cargas negativas, não favorecem a atividade biológica dos derivados naftoimidazólicos. Para o cálculo do ancoramento molecular foi utilizada a enzima cruzaína de T. cruzi, devido sua importância em todos os estágios do ciclo de vida do parasito. Realizado o ancoramento molecular verificou-se que as interações mais relevantes são as de empilhamento, as interações com anel imidazol e interações nas posições orto e para do anel naftaleno para os derivados FSE.

Submitted by Erika Demachki (erikademachki@gmail.com) on 2014-11-18T17:34:04Z No. of bitstreams: 2 Tese - Benedito R Neto da Silva Neto - 2013.pdf: 6956298 bytes, checksum: 49e69215087afc3b1ae2471385d29585 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Erika Demachki (erikademachki@gmail.com) on 2014-11-18T17:34:16Z (GMT) No. of bitstreams: 2 Tese - Benedito R Neto da Silva Neto - 2013.pdf: 6956298 bytes, checksum: 49e69215087afc3b1ae2471385d29585 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2014-11-18T17:34:18Z (GMT). No. of bitstreams: 2 Tese - Benedito R Neto da Silva Neto - 2013.pdf: 6956298 bytes, checksum: 49e69215087afc3b1ae2471385d29585 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2013-05-02 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / The thermally dimorphic fungal pathogen Paracoccidioides is the agent of paracoccidioidomycosis. This disease is characterized by a granulomatous inflammation with clinical forms ranging from a benign localized infection to a disseminated one. The triazole drugs are broad-spectrum antifungal agents and are currently used to treat infections caused by various pathogenic yeast and molds. The mechanism of action of azoles has been elucidated in some fungi, although little is known in Paracoccidioides. Here we aim to investigate the mechanism of action of itraconazole on Paracoccidioides by using Representational Difference Analysis from Paracoccidioides yeast cells grown in the absence and presence of itraconazole for 1 and 2 h. Among the Paracoccidioides genes up-regulated by itraconazole were those mainly involved in cellular transport, metabolism/energy, transcription, cell rescue, defense and virulence. ERG11, ERG6, ERG3, ERG5 and ERG25 were up-regulated when evaluated in a timely manner. In vivo infection experiment in mice corroborated in vitro results. The glyoxylate cycle and its key enzymes isocitrate lyase and malate synthase (MLS) play a crucial role in the pathogenicity and virulence of various fungi such as the human pathogens. Here, we describe a study conducted to develop rational ligands as candidates to inhibit receptor PbMLS. The important step in the search for ligands for this receptor based on structural homology, molecular docking and molecular dynamics involving scanning virtual (virtual screening) through the program AutoDock Vina. Identified from the database of natural compounds (ZINC data bank) potential candidate ligands to inhibit the activity of PbMLS when compared to the original binder. This process led us to monoterpene indole alkaloids of the genus Palicourea (Rubiaceae) comprises about 230 species from shrubs and small trees distributed mainly in tropical regions. From the molecular docking fifteen compounds were tested as to its effectiveness in inhibiting the activity of PbMLS. The specific activity of PbMLS was affected by the compounds. Four indol alkaloids showed ability to reduce the enzyme activity. Since PbMLS is a linked surface protein that behaves as an anchorless adhesin, and PbICL is here described as adhesin, we also investigated if those compounds inhibit the adhesion of the protein to extracellular. Twodimensional gel electrophoresis we used to investigate the proteins expressed differentially during treatment with itraconazole and amphotericin B. Gels of three independent biological replicates were digitalized and the images were analyzed using the ImageMaster 2D Platinum 6.0 software (GE Healthcare). Spot intensities were normalized and the statistics analyses were estimated by one-way ANOVA. The spots of interest were excised, in-gel digested with trypsin, and the peptides were then analyzed by MS and/or MS/MS and and sequenced. The results obtained here should assist in understanding the mode of action of drugs in Paracoccidioides, and outline studies identifying compounds with antifungal activity. / O fungo patógeno termodimórfico Paracoccidioides é o agente da paracoccidioidomicose. Esta doença é caracterizada por uma inflamação granulomatosa onde as formas clínicas vão da infecção localizada benigna a uma uma disseminada. As drogas triazólicas são antifúngicos de amplo espectro e são usadas atualmente para tratar infecções causadas por vários fungos patogênicos e fungos. O mecanismo de ação dos azólicos foi elucidado em alguns fungos, embora pouco se sabe em Paracoccidioides. Aqui, em primeiro lugar pretendemos investigar o mecanismo de ação do itraconazol em Paracoccidioides usando análise de diferença representacional de Paracoccidioides células de levedura crescidas na ausência e na presença de itraconazol por 1 e 2 horas. Entre os genes Paracoccidioides up-regulados pelo itraconazol foram os envolvidos, principalmente no transporte celular, metabolismo/energia, transcrição, defesa e virulência. ERG11, ERG6, ERG3, ERG5 e ERG25 foram regulados quando avaliados de forma temporal. Experimentos de infecção em camundongos corroborou resultados in vitro. O ciclo do glioxilato e suas enzimas chave isocitrato liase (ICL) e malato sintetase (MLS) desempenham um papel fundamental na patogenicidade e virulência de vários fungos, assim como patogênese em humanos. Neste trabalho, descrevemos um estudo realizado para desenvolver ligantes racionais como candidatos pra inibir o receptor PbMLS. Apresentamos um passo importante na busca de ligantes para este receptor baseando-se em homologia de estruturas, dinâmica molecular e acoplamento molecular envolvendo varredura virtual (virtual screening) por meio do programa AutoDock Vina. Identificamos a partir de banco de compostos naturais (data bank ZINC) potenciais ligantes candidatos a inibir a atividade de PbMLS quando comparados ao ligante original. Este processo nos conduziu aos alcalóides indólicos monoterpênicos do gênero Palicourea (Rubiaceae) que compreende cerca de 230 espécies entre arbustos e pequenas árvores distribuídas, principalmente, nas regiões tropicais.A partir da ancoragem molecular quinze compostos foram testados quanto à sua eficácia na inibição da atividade de PbMLS. A atividade específica de PbMLS foi afetado pelos compostos. Quatro alcalóides indólico mostraram capacidade de reduzir a atividade da enzima. Desde que PbMLS é uma proteína associada à superfície que se comporta como uma adesina ancorada também foi investigado se os compostos inibem a adesão da proteína às matrizes extracelulares. O processo de eletroforese em gel bidimensional foi utilizado para investigar as proteínas diferencialmente expressas durante o tratamento com itraconazol e anfotericina B. Gel de três réplicas biológicas independentes foram digitalizadas e as imagens foram analisadas usando o software 6.0 Platinum 2D ImageMaster (GE Healthcare). Intensidades dos spots foram normalizados e foram estimadas as análises estatísticas por ANOVA one-way. Os spots de interesse foram excisadas do gel digerida com tripsina e os péptidos foram analisados por MS e / ou MS / MS e sequenciados. Os resultados obtidos aqui devem ajudar na compreensão do mecanismo de ação de drogas em Paracoccidioides, e delinear estudos de identificação de compostos com atividade antifúngica.

Submitted by JÚLIO HEBER SILVA (julioheber@yahoo.com.br) on 2016-11-10T10:37:56Z No. of bitstreams: 2 Dissertação - Uessiley Ribeiro Barbosa - 2016.pdf: 3901383 bytes, checksum: f52c92a81d289db26f933d75a30e8788 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Jaqueline Silva (jtas29@gmail.com) on 2016-11-10T17:48:40Z (GMT) No. of bitstreams: 2 Dissertação - Uessiley Ribeiro Barbosa - 2016.pdf: 3901383 bytes, checksum: f52c92a81d289db26f933d75a30e8788 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2016-11-10T17:48:40Z (GMT). No. of bitstreams: 2 Dissertação - Uessiley Ribeiro Barbosa - 2016.pdf: 3901383 bytes, checksum: f52c92a81d289db26f933d75a30e8788 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-10-04 / The Paracoccidioides brasiliensis (Pb) is a thermo-dimorphic fungus described as the etiological agent of paracoccidioidomycosis (PCM), an important systemic mycosis in Latin America. The isocitrate lyase (ICL) is an enzyme involved in glyoxylate cycle, an alternative pathway to Krebs cycle, which has been described in fungi, bacteria and plants. The absence of this enzyme in mammals makes it an interesting target for design of specific antifungal compounds for PCM. In this work, we use in silico methods like homology modeling, molecular dynamics and virtual screening, aiming the development of inhibitors compounds for PbICL enzyme in the absence and presence of cofactor and positive control. From a molecular docking protocol, it was possible to select promising compounds by criteria of affinity and efficiency based on screening of natural products. Two regions were selected for molecular docking, one involving a region already known by the binding of argentilactona inhibitor and another region involving the cofactor Mg 2+, a possible catalytic site of ICL. All compounds selected by affinity criteria had more than 80% of success rate in achieving lower energy and allowed to describe common residues within the protein interaction for the target sites. The structural quality parameters are significantly improved after 100 ns of simulation. The structure of PbICL and PbICL with magnesium show all quality parameters as acceptable to define them as highresolution structures. All selected compounds show aromatic chains with the possibility of being a pharmacophore, which is essential for biological activity. Another interesting aspect is that, through the selected compounds, it was possible to describe structural patterns related to the ligand specificity, that might be promising for a basic chemical sketch for rational drug design. / O Paracoccidioides brasiliensis (Pb) é um fungo termo-dimórfico descrito como agente etiológico da paracoccidioidomicose (PCM), uma micose sistêmica importante na América Latina. A Isocitrato liase (ICL) é uma enzima envolvida no ciclo do glioxilato, uma via do ciclo Krebs já descritos em fungos, bactérias e plantas. Sua ausência em mamíferos faz dessa enzima, um alvo interessante para o desenho de compostos antifúngicos específicos para a PCM. Neste trabalho, utilizamos métodos in silico como modelagem por homologia, dinâmica molecular e triagem virtual na busca de compostos inibidores para enzima isocitrato liase de P brasilienses (PbICL) na ausência e presença do cofator e com a seleção de controle positivo. A partir de um protocolo de ancoragem molecular, foi possível selecionar compostos promissores por critérios de afinidade e eficiência a partir de triagens virtuais com produtos naturais. Duas regiões foram selecionadas para a ancoragem molecular, uma envolvendo uma região já conhecida pela ligação do inibidor argentilactona e outra envolvendo a região de ligação do cofator Mg2+ , posicionada no possível sítio catalítico da enzima. Todos os compostos selecionados pelo critério de afinidade tiveram mais do que 80% de sucesso em alcançar a mais baixa energia e permitiram descrever resíduos frequentes na interação proteína-inibidor para sítios alvo da enzima. Os parâmetros de qualidade da estrutura são sensivelmente melhorados após 100 ns de simulação. As estruturas de PbICL e PbICL com Mg2+ apresentam todos os parâmetros dentro do aceitável para defini-la como estrutura de alta resolução. Todos os compostos selecionados apresentaram cadeias aromáticas com possibilidade de ser um grupo farmacofórico, o qual é essencial para a atividade biológica. Outro aspecto interessante é que através dos compostos selecionados foi possível descrever padrões estruturais relacionados à especificidade do composto, os quais podem vir a ser promissores para um esqueleto básico no desenho racional de fármacos.

Ce travail de thèse consiste au développement méthodologique et logiciel d'une méthode de docking moléculaire dite inverse. Cette méthode propose à travers le programme AMIDE — Automatic Inverse Docking Engine — de distribuer un grand nombres de simulations d'amarrage moléculaire sur des architectures HPC (clusters de calcul) avec les applications AutoDock 4.2 et AutoDock Vina. Le principe de cette méthode consiste à tester de petites molécules sur un ensemble de protéines cibles potentielles. Les paramètres optimaux ont été définis à partir d'une étude pilote et le protocole a été validé sur des ligands et peptides liants les protéines MMPs et EBP de la matrice extracellulaire. Cette méthode montre qu'elle permet d‘améliorer la recherche conformationnelle lors du calcul de docking sur des structures expérimentales par rapport à des protocoles existants (blind docking). Il est montré que le programme AMIDE permet de discriminer des sites de fixation privilégiés lors d'expériences de criblage inverse de protéines de manière plus performante que par blind docking. Ces résultats sont obtenus par la mise en place de méthodes de partitionnement de l'espace de recherche qui permettent également à travers un système de distribution hybride de déployer un ensemble de tâches indépendantes pour un traitement autorisant le passage d'échelle. / This work is a methodological and software development of so-called inverse molecular docking method. This method offers through an in house program AMIDE — Automatic Reverse Docking Engine — to distribute large numbers of molecular docking simulations on HPC architectures (com- puting clusters) with AutoDock 4.2 and AutoDock Vina applications. The principle of this method is to test small molecules on a set of potential target proteins. The program optimum parameters were defined from a pilot study and the protocol was validated on ligands and peptides binding MMPs and EBP extracellular matrix proteins. This method improves the conformational search in docking computation on experimental structures compared to existing protocols (blind docking). It is shown that the AMIDE program is more efficient to discriminate preferred binding sites in inverse proteins screening experiments than blind docking. These results are obtained by the implemen- tation of methods for partitioning the search space that also allow through a hybrid distribution system to deploy a set of independent embarassingly parallel tasks perfectly scalable.

Orientadores: João Ernesto de Carvalho, Mary Ann Foglio / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-18T11:34:15Z (GMT). No. of bitstreams: 1 Rizzo_LarissaYokota_M.pdf: 2545881 bytes, checksum: 63ab51d7b009706ec8505aa2b3ded262 (MD5) Previous issue date: 2011 / Resumo: A pesquisa de drogas anticâncer através da triagem de extratos e princípios ativos obtidos de fontes naturais possibilitou a descoberta e o desenvolvimento de diversos quimioterápicos hoje utilizados no tratamento do câncer. Este projeto teve como objetivo avaliar a atividade anticâncer de Psidium guajava L. (nome popular: goiabeira), espécie eleita através de levantamento etnofarmacológico para atividade antiparasitária. Após a colheita, o material vegetal foi submetido a um processo de extração a quente por Soxhlet, com diclorometano e etanol 95%, originando o extrato bruto diclorometânico (EBD) e etanólico (EBE), respectivamente. O extrato bruto ativo, EBD, foi submetido a diversos fractionamentos biomonitorados, até a obtenção de uma fração enriquecida nos meroterpenos guajadial, psidial A e seus isômeros, princípios ativos da espécie vegetal. Todas as amostras (extratos brutos e frações enriquecidas) tiveram sua potencial atividade anticâncer avaliadas in vitro frente a um painel de dez linhagens tumorais humanas, cedidas pelo National Cancer Institute (NCI, Estados Unidos), a saber: K562 (leucemia), MCF-7 (mama), NCI/ADR-RES (ovário resistente a múltiplas drogas), NCI-H460 (pulmão), UACC62 (melanoma), PC-3 (próstata), HT-29 (cólon), OVCAR-03 (ovário), U251 (glioma) and 786-0 (rim). A fração ativa enriquecida nos meroterpenos foi avaliada in vivo no tumor sólido de Ehrlich, em camundongos Balb/C, reduzindo significativamente o crescimento tumoral. Além da atividade antitumoral observada in vivo, a análise macroscópica do útero indicou aumento em tamanho e peso em relação aos grupos controle negativo (salina) e positivo (doxorrubicina). As moléculas de guajadial e psidial A apresentam propriedades físico-químicas semelhantes ao estradiol e ao tamoxifeno e estudos de docking molecular sugerem que ambos os compostos se liguem no sítio de ligação no receptor de estrógeno (ER), analogamente ao tamoxifeno. A capacidade de reduzir o crescimento tumoral e, ao mesmo tempo, estimular o útero indicam que guajadial e psidial A possivelmente agem como fitoestrógenos, possuindo um mecanismo de ação semelhante ao tamoxifeno, atuando como SERMs (Selective Estrogen Receptor Modulators) e agindo como agonistas e antagonistas de forma tecido específica / Abstract: Anticancer drug research based on screening of natural sources enabled the discovery of several drugs that are used in cancer treatment. This project aimed to evaluate the in vitro and in vivo anticancer activity of Psidium guajava L. (popular name: guava), elected for its ethnopharmacological use for antiparasitic activity. After harvesting, the vegetal material was extracted in Soxhlet with dicloromethane and then ethanol 95%, leading to the dicloromethane crude extract (DCE) and the ethanolic crude extract (ECE), respectively.The active extract, DCE, was submitted to several biomonitored fractionating processes and an active mixture of meroterpenes identified guajadial, psidial A and its isomers as active principles. All samples (crude extract and enriched fractions) were evaluated in vitro for cytotoxic activity against ten human cancer lines (donated by National Cancer Institute, USA): K562 (leukemia), MCF-7 (breast), NCI/ADR-RES (resistant ovarian cancer), NCI-H460 (lung), UACC62 (melanoma), PC-3 (prostate), HT-29 (colon), OVCAR-03 (ovary), U251 (glioma) and 786-0 (kidney). Meroterpenes enriched fraction was evaluated in vivo in the Solid Ehrlich Tumor, in Balb/C mice, and significantly reduced tumor growth. Besides antitumoral activity, macroscopic analysis of uterus showed increased size and weight in comparison to both negative (vehicle) and positive (doxorubicin) control groups. The molecules of guajadial and psidial A display similar physicochemical properties to estradiol and tamoxifen and in silico molecular docking studies suggest that both molecules bind to the estrogen-binding site of ERs analogously to tamoxifen. The ability to reduce breast cancer tumor growth and stimulate the uterus suggests that guajadial and psidial A may act as phytoestrogens, giving insights for a mechanism of action similar to tamoxifen, acting as SERMs (Selective Estrogen Receptor Modulators), having both agonist and antagonist tissue-specific activities / Mestrado / Histologia / Mestre em Biologia Celular e Estrutural

No description available.

Orientador: Ana Carolina Gomes Jardim / Resumo: Nas últimas décadas, diversos vírus que tinham sua ocorrência limitada a pequenas regiões se espalharam pelo globo, causando epidemias e preocupação entre as autoridades de saúde. Apesar dos inúmeros avanços no tratamento das infecções virais, vários destes vírus ainda não possuem tratamento especifico e eficaz. Adicionalmente, a alta taxa de resistência e o surgimento de novas mutações, torna a busca por novos antivirais desafiadora e de extrema importância. Desta forma, o presente trabalho teve como objetivo investigar a atividade antiviral de compostos de origem natural ou sintética contra os vírus da Chikungunya (CHIKV) e Enterovirus A71 (EV-A71). Contra o CHIKV, 48.750 compostos sintéticos foram inicialmente avaliados in silico por docking molecular, dos quais 12 compostos demonstraram apresentar interação com a região de ligação a ADP-ribose do dominío macro da proteína viral não estrutural 3 (nsP3), e foram selecionados para ensaios in vitro. Ensaios de viabilidade celular foram realizados para determinar a máxima concentração não tóxica de cada composto, que foi utilizada nos ensaios anti-CHIKV em células de hepatocarcimona humano Huh-7, transfectadas com os replicons subgenômicos do CHIKV. Os resultados demonstraram que os compostos C5 e C13 na concentração de 20 µM inibiram 53 e 76% da replicação do CHIKV em células Huh-7, respectivamente. Contra o EV-A71, 6 proteínas isoladas da peçonha de serpentes foram testadas em concentrações não tóxicas em células Vero infect... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: In the last decades, several viruses that had their occurrence limited to small regions spread through the globe, causing epidemics and concern among health authorities. Despite the numerous advances in the treatment of viral infections, several of these viruses have no specific and effective treatment yet. In addition, the high rate of resistance and the emergence of new mutations, makes the search for new antivirals challenging and extremely important. The present work aimed to investigate the antiviral activity of compounds from natural or synthetic origin against Chikungunya virus (CHIKV) and Enterovirus A71 (EV-A71). Against CHIKV, 48,750 synthetic compounds were initially evaluated in silico by molecular docking, of which 12 compounds demonstrated to be interacting with the ADP-ribose binding region of viral non- structural protein 3 (nsP3) macro domain and were selected for in vitro assays. Cell viability assays were performed to determine the maximum non-toxic concentration of each compound and used in anti-CHIKV assays in human hepatocarcinoma cells (Huh-7) transiently transfected with the CHIKV subgenomics replicons. The results demonstrated that the C5 and C13 compounds at 20 µM inhibited 53 and 76% of CHIKV replication in Huh-7 cells, respectively. Against EV-A71, 6 proteins isolated from snake venom were tested at non-toxic concentrations in infected Vero cells, and the virucidal, protective and anti-EV-A71 replication activity was evaluated. From the tested toxi... (Complete abstract click electronic access below) / Doutor

La nécroptose est une mort cellulaire régulée impliquée dans les pathologies inflammatoires, ischémiques et dégénératives. RIPK1 serait une cible thérapeutique intéressante car son activité kinase serait à l’origine de leur initiation ou aggravation. Nous avons caractérisé les effets biologiques de deux nouveaux inhibiteurs de RIPK1. La sibiriline protège les souris d’une hépatite autoimmune et 6E11 protège les cellules endothéliales de l’aorte de la mort par ischémie froide/réoxygénation, suggérant des propriétés intéressantes pour ces inhibiteurs. Ces composés diffèrent par leur mode d’action, d’interaction et de sélectivité, et restent à optimiser en vue d’une utilisation thérapeutique. / Necroptosis is a regulated cell death pathway involved in inflammatory, ischemic or degenerative diseases. RIPK1 would be an interesting therapeutic target since its kinase activity is probably responsible of their initiation or aggravation. We have characterized the biological effects of two new RIPK1 inhibitors. Sibirilin protects mice from autoimmune hepatitis and 6E11 protects endothelial aortic cells from death due to cold ischemia/reoxygenation, suggesting interesting properties for these inhibitors. These compounds differ in their mode of action, interaction and selectivity, and still need to be optimized for therapeutic use.

Yes / Magnolia champaca Linn. has traditionally been used for medicinal activity in Asia for treating various chronic diseases as well as a source of food, medicines, and other commodities. Due to the long-used history of this plant, the present study was designed to explore the in vitro, in vivo and in silico anti-inflammatory and antineoplastic properties of the methanolic extract and fractions and the pure compound isolated from the most active chloroform fraction (CHF) of the stem bark of the plant. The isolated compound from the most active CHF was characterized and identified as a glycoside, trans-syringin, through chromatographic and spectroscopic (1H-NMR and 13C-NMR) analyses. In the in vitro anti-inflammatory assay, CHF was most effective in inhibiting inflammation and hemolysis of RBCs by 73.91 ± 1.70% and 75.92 ± 0.14%, respectively, induced by heat and hypotonicity compared to standard acetylsalicylic acid. In the egg albumin denaturation assay, CME and CHF showed the highest inhibition by 56.25 ± 0.82% and 65.82 ± 3.52%, respectively, contrasted with acetylsalicylic acid by 80.14 ± 2.44%. In an in vivo anti-inflammatory assay, statistically significant (p < 0.05) decreases in the parameters of inflammation, such as paw edema, leukocyte migration and vascular permeability, were recorded in a dose-dependent manner in the treated groups. In the antineoplastic assay, 45.26 ± 2.24% and 68.31 ± 3.26% inhibition of tumor cell growth for pure compound were observed compared to 73.26 ± 3.41% for standard vincristine. Apoptotic morphologic alterations, such as membrane and nuclear condensation and fragmentation, were also found in EAC cells after treatment with the isolated bioactive pure compound. Such treatment also reversed the increased WBC count and decreased RBC count to normal values compared to the untreated EAC cell-bearing mice and the standard vincristine-treated mice. Subsequently, in silico molecular docking studies substantiated the current findings, and the isolated pure compound and standard vincristine exhibited −6.4 kcal/mol and −7.3 kcal/mol binding affinities with topoisomerase-II. Additionally, isolated pure compound and standard diclofenac showed −8.2 kcal/mol and −7.6 kcal/mol binding affinities with the COX-2 enzyme, respectively. The analysis of this research suggests that the isolated bioactive pure compound possesses moderate to potent anti-inflammatory and antineoplastic activity and justifies the traditional uses of the stem bark of M. champaca. However, further investigations are necessary to analyze its bioactivity, proper mechanism of action and clinical trials for the revelation of new drug formulations.

As estruturas e propriedades biológicas das amidas piplartina e a piperina, isoladas respectivamente de Piper tuberculatum e P. nigrum, inspiraram a síntese de 89 derivados e 7 esters estruturalmente relacionadas. As preparações envolveram metodologias tradicionais e os compostos purificados tiveram suas estruturas caracterizadas por análises espectroscópicas e espectrométricas. Os estudos de fragmentação por IE e IES indicaram a clivagem preferencial da ligação N-CO no caso das cinamamidas, dienamidas e cinamimidas. Estudos computacionais envolvendo afinidade protônica e energias de ligação confirmaram a fragmentação preferencial da ligação amídica para as amidas. A citotoxicidade de 89 substâncias foi avaliada contra três células leucêmicas (K562, Nalm6 e Raji) e a partir dos valores de IC50 foram realizados estudos de relação estrutura-atividade (SAR). As linhagens K562 e a Nalm6 foram a mais resistente e vulnerável, respectivamente, e as amidas piplartina (1a), N-Ciclohexil-N-(ciclohexilcarbamoil)-3-(3,4,5-trimetoxifenil)propanamida (1n), e (E)-N,N-dibutil-3-(3,4-dimetoxifenil)acrilamida (13h) foram as mais ativas com IC50 de 0,34 &#181;M; 0,84 &#181;M e 1,88 &#181;M contra K562 e (E)-N-ciclohexil-N-(ciclohexilcarbamoil)-3-(3,4-dimetoxifenil)acrylamida (13i) com IC50 de 0,98 &#181;M contra Nalm6. A avaliação de atividade leishmanicida de 18 substâncias não se mostrou promissora. As abordagens qualitativas e quantitativas foram feitas baseadas nos descritores moleculares gerados pelo programa VolSurf+. A partir de métodos quimiométricos tais com PLS, algoritmo genético, árvores de decisão foi possível gerar modelos para correlacionar às propriedades moleculares com a atividade biológica. As propriedades de absorção, distribuição, metabolismo e excreção e os equilíbrios entres as regiões hidrofílicas e hidrofóbicas foram importantes para atividade citotóxica. O estudo de ancoragem molecular mostrou que as amidas (E)-N,N-dibutil-3-(3,4,5-trimetoxifenil)acrilamida (1l), 1n, (E)-3-(4-clorofenil)-N-ciclohexil-N-(ciclohexilcarbamoil)acrilamida (5a), 13h e 13i podem atuar como inibidores das histonas desacetilases particularmente HDAC4 e HDAC8. / The structures and biological properties of the amides piplartine and piperine isolated from Piper tuberculatum and P. nigrum respectively, inspired the synthesis of derivatives 89 and 7 esters structurally related. Their preparations were achieved using classical procedures and the purified amides were submitted to spectroscopic and spectrometric characterization. The study of fragmentation process by EI and ESI suggested the preferential cleavage of the N-CO bond of cinnamamides, dienamides and cinnamimides. The cytotoxicity of 89 compounds was evaluated against three leukemic cells (K562, Nalm6 and Raji) and based on IC50 values the structure-activity relationship (SAR) was performed. While the K562 and Nalm6 cells were the more resistant and more sensitive, respectively, the amides piplartine (1a), N-cyclohexyl-N-(ciclohexylcarbamoyl)-3-(3,4,5-trimethoxyphenyl)propanamide (1n) and (E)-N,N-dibutyl-3-(3,4-dimethoxyphenyl)acrylamide (13h) were in general the most active with IC50 of 0.34 &#181;M, 0.84 &#181;M and 1.88 &#181;M against K562 and (E)-N-cyclohexyl-N-(ciclohexylcarbamoyl)-3-(3,4-dimethoxyphenyl)acrylamide (13i) with IC50 of 0.98 &#181;M against Nalm6. The evaluation of leishmanicidal activity of 18 substances was also performed but was not promising. Qualitative and quantitative approaches were made based on molecular descriptors generated by VolSurf+ program. The chemometric methods such as PLS, genetic algorithm, decision trees generated models to correlate molecular properties with the biological activity. The absorption, distribution, metabolism and excretion properties and a balance between hydrophilic and hydrophobic moieties of the amides were important for an optimized activity. The molecular docking revealed that amides such as (E)-N,N-dibutyl-3-(3,4,5-trimethoxyphenyl)acrylamide (1l), 1n, (E)-3-(4-chlorophenyl)-N-cyclohexil-N-(cyclohexylcarbamoyl)acrylamide (5a), 13h and 13i have potential to act as possible inhibitors of histone deacetylase proteins particularly HDAC4 and HDAC8.