868 resultados para Anti Retroviral Agents
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Poster presented at the From Basic Sciences to Clinical Research - First International Congress of CiiEM. Egas Moniz, Caparica, Portugal, 27- 28 November 2015
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Purpose: To investigate the phytochemistry and cytotoxic activity of stem bark extracts from Genus dolichocarpa and Duguetia chrysocarpa - two species of the Annonaceae family. Methods: The crude ethanol bark extracts (EtOH) of the plants were obtained by maceration. The crude extracts were suspended in a mixture of methanol (MeOH) and water (H2O) (proportion 3:7 v/v) and partitioned with hexane, chloroform (CHCl3) and ethyl acetate (AcOEt) in ascending order of polarity to obtain the respective fractions. The extracts were evaluated on thin layer chromatography (TLC) plates of silica gel to highlight the main groups of secondary metabolites. Cytotoxicity was tested against human tumor cell lines - OVCAR-8 (ovarian), SF-295 (brain) and HCT-116 (colon) - using 3- (4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. Results: The screening results demonstrated that all the extracts were positive for the presence of flavonoids and tannins. The presence of alkaloids also was detected in some extracts. The hexane extract of A. dolichocarpa showed the strongest cytotoxicity against HCT-116 with cell growth inhibition of 89.02 %. Conclusion: The findings demonstrate for the first time the cytotoxic activity of the extracts of A. dolichocarpa and D. chrysocarpa, thus providing some evidence that plants of the Annonaceae family are a source of active secondary metabolites with cytotoxic activity.
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O cancro é a segunda causa de mortalidade a nível mundial. Um dos problemas nos tratamentos atuais de quimioterapia relaciona-se com os efeitos secundários causados pela falta de seletividade dos fármacos utilizados. Assim, um dos desafios atuais é o desenvolvimento de sistemas terapêuticos que permitam potenciar o efeito dos fármacos e diminuir os seus efeitos nocivos. Neste contexto, neste trabalho, foram sintetizados complexos de Fe, Co e Zn com fórmula geral [M(bipy-R)3]x+, a partir dos quais foi possível obter sistemas micelares formados in situ pela adição de um copolímero de PLA-b-PEG ou por introdução de macroligandos poliméricos anfifílicos. Os resultados mostram que as nanopartículas formadas apresentam tamanho e características adequadas para aplicações na terapia dirigida contra o cancro. Os resultados preliminares de citotoxicidade na linha tumoral humana da mama MDAMB231 indicam que todos os compostos estudados apresentam atividade citotóxica relevante, sendo os compostos micelares os mais promissores; Abstract: New micellar transition metals complexes for targeted therapy of cancer Cancer is the second leading cause of mortality worldwide. One problem in the current chemotherapy treatments is related to the severe side effects caused by the lack of selectivity of the drugs in clinical use. Thus, one of the current challenges is the development of new therapeutic systems that allow maximizing the effect of the drugs and reducing their harmful effects. In this context, several Fe, Co and Zn compounds of the general formula [M (bipy-R)3]x+ were synthesized in order to obtain micellar systems, either by in situ addition of a PLA-b-PEG copolymer or by introducing amphiphilic macroligands. The results show that the formed nanoparticles have size and characteristics suitable for applications in targeted therapy against cancer. Preliminary results of cytotoxicity in human breast cancer line MDAMB231 indicate that all the studied compounds show significant cytotoxic activity, being the micellar compounds the most promising agents.
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Strategies that confine antibacterial and/or antifouling property to the surface of the implant, by modifying the surface chemistry and morphology or by encapsulating the material in an antibiotic-loaded coating, are most promising as they do not alter bulk integrity of the material. Among them, plasma-assisted modification and catechol chemistry stand out for their ability to modify a wide range of substrates. By controlling processing parameters, plasma environment can be used for surface nano structuring, chemical activation, and deposition of biologically active and passive coatings. Catechol chemistry can be used for material-independent, highly-controlled surface immobilisation of active molecules and fabrication of biodegradable drug-loaded hydrogel coatings. In this article, we comprehensively review the role plasma-assisted processing and catechol chemistry can play in combating bacterial colonisation on medically relevant coatings, and how these strategies can be coupled with the use of natural antimicrobial agents to produce synthetic antibiotic-free antibacterial surfaces.
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This thesis reports on a method to improve in vitro diagnostic assays that detect immune response, with specific application to HIV-1. The inherent polyclonal diversity of the humoral immune response was addressed by using sequential in situ click chemistry to develop a cocktail of peptide-based capture agents, the components of which were raised against different, representative anti-HIV antibodies that bind to a conserved epitope of the HIV-1 envelope protein gp41. The cocktail was used to detect anti-HIV-1 antibodies from a panel of sera collected from HIV-positive patients, with improved signal-to-noise ratio relative to the gold standard commercial recombinant protein antigen. The capture agents were stable when stored as a powder for two months at temperatures close to 60°C.
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In order to find compounds with superior anti human immunodeficiency virus type 1 (HIV-1) activity, twelve simple N-arylsulfonylindoles (3a-1) were synthesized and preliminarily evaluated as HIV-1 inhibitors in vitro for the first time. Several compounds
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Ten dibenzofurans were synthesized and evaluated as human immunodeficiency virus (HIV)-1 inhibitors in vitro for the first time. Among these compounds, compounds 1, 6, 7 and 8 demonstrated significant anti-HIV-1 activity. Especially compound 1 showed the
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Ten single benzyl phenyl ethers were synthesized and evaluated as human immunodeficiency virus-1 (HIV-1) inhibitors in vitro for the first time. Among these compounds, especially 4-nitrobenzyl phenyl ether (3h) exhibited the highest anti-HIV-1 activity wi
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To search for compounds with superior anti-human immunodeficiency virus type 1 (HIV-1) activity, ten 5,5'-(p-phenylenebisazo)-8-hydroxyquinoline sulfonates (4a-j) were synthesized and preliminarily evaluated as HIV-1 inhibitors in vitro for the first time. Some compounds demonstrated anti-HIV-1 activity, especially 5,5'-(p-phenylenebisazo)-8-hydroxyquinoline p-ethylbenzenesulfonate (4g) and 5,5'-(p-phenylenebisazo)-8-hydroxyquinoline p-chlorobenzenesulfonate (41) showed the more potent anti-HIV-1 activity with 50% effective concentration (EC50) values of 2.59 and 4.01 mu g/ml, and therapeutic index (TI) values of 31.77 and 24.51, respectively.
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In continuation of our program aimed at the discovery and development of compounds with superior anti-human immunodeficiency virus type 1 (HIV-1) activity, 21N-arylsulfonyl-3-acetylindole analogs (2a-u) were synthesized and preliminarily evaluated as HIV-1 inhibitors in vitro. Among of all the analogs, several compounds exhibited significant anti-HIV-1 activity, especially N-phenylsulfonyl-3-acetyl-6-methylindole (2j) and N-(p-ethyl)phenylsulfonyl-3-acetyl-6-methylindole (2n) showed the most potent anti-HIV-1 activity with EC50 values of 0.36 and 0.13 mu g/mL, and TI values of >555.55 and 791.85, respectively. It demonstrated that introduction of the acetyl group at the 3-position of N-arylsulfonyl-6-methylindoles could generally lead to the more potent analogs. (C) 2010 Elsevier Ltd. All rights reserved.
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Les agents anti-infectieux sont utilisés pour traiter ou prévenir les infections chez les humains, les animaux, les insectes et les plantes. L’apparition de traces de ces substances dans les eaux usées, les eaux naturelles et même l’eau potable dans plusieurs pays du monde soulève l’inquiétude de la communauté scientifique surtout à cause de leur activité biologique. Le but de ces travaux de recherche a été d’étudier la présence d’anti-infectieux dans les eaux environnementales contaminées (c.-à-d. eaux usées, eaux naturelles et eau potable) ainsi que de développer de nouvelles méthodes analytiques capables de quantifier et confirmer leur présence dans ces matrices. Une méta-analyse sur l’occurrence des anti-infectieux dans les eaux environnementales contaminées a démontré qu’au moins 68 composés et 10 de leurs produits de transformation ont été quantifiés à ce jour. Les concentrations environnementales varient entre 0.1 ng/L et 1 mg/L, selon le composé, la matrice et la source de contamination. D’après cette étude, les effets nuisibles des anti-infectieux sur le biote aquatique sont possibles et ces substances peuvent aussi avoir un effet indirect sur la santé humaine à cause de sa possible contribution à la dissémination de la résistance aux anti-infecteiux chez les bactéries. Les premiers tests préliminaires de développement d’une méthode de détermination des anti-infectieux dans les eaux usées ont montré les difficultés à surmonter lors de l’extraction sur phase solide (SPE) ainsi que l’importance de la sélectivité du détecteur. On a décrit une nouvelle méthode de quantification des anti-infectieux utilisant la SPE en tandem dans le mode manuel et la chromatographie liquide couplée à la spectrométrie de masse en tandem (LC-MS/MS). Les six anti-infectieux ciblés (sulfaméthoxazole, triméthoprime, ciprofloxacin, levofloxacin, clarithromycin et azithromycin) ont été quantifiés à des concentrations entre 39 et 276 ng/L dans les échantillons d’affluent et d’effluent provenant d’une station d’épuration appliquant un traitement primaire et physico- chimique. Les concentrations retrouvées dans les effluents indiquent que la masse moyenne totale de ces substances, déversées hebdomadairement dans le fleuve St. Laurent, était de ~ 2 kg. En vue de réduire le temps total d’analyse et simplifier les manipulations, on a travaillé sur une nouvelle méthode de SPE couplée-LC-MS/MS. Cette méthode a utilisé une technique de permutation de colonnes pour préconcentrer 1.00 mL d’échantillon dans une colonne de SPE couplée. La performance analytique de la méthode a permis la quantification des six anti-infectieux dans les eaux usées municipales et les limites de détection étaient du même ordre de grandeur (13-60 ng/L) que les méthodes basées sur la SPE manuelle. Ensuite, l’application des colonnes de SPE couplée de chromatographie à débit turbulent pour la préconcentration de six anti-infectieux dans les eaux usées a été explorée pour diminuer les effets de matrice. Les résultats obtenus ont indiqué que ces colonnes sont une solution de réchange intéressante aux colonnes de SPE couplée traditionnelles. Finalement, en vue de permettre l’analyse des anti-infectieux dans les eaux de surface et l’eau potable, une méthode SPE couplée-LC-MS/MS utilisant des injections de grand volume (10 mL) a été développée. Le volume de fuite de plusieurs colonnes de SPE couplée a été estimé et la colonne ayant la meilleure rétention a été choisie. Les limites de détection et de confirmation de la méthode ont été entre 1 à 6 ng/L. L’analyse des échantillons réels a démontré que la concentration des trois anti-infectieux ciblés (sulfaméthoxazole, triméthoprime et clarithromycine) était au dessous de la limite de détection de la méthode. La mesure des masses exactes par spectrométrie de masse à temps d’envol et les spectres des ions produits utilisant une pente d’énergie de collision inverse dans un spectromètre de masse à triple quadripôle ont été explorés comme des méthodes de confirmation possibles.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)