A concise enantioselective synthesis of (+)-endo-brevicomin accomplished by a tellurium/metal exchange reaction

A homoenolate generated by tellurium/lithium exchange reaction was employed in a straightforward enantioselective synthesis of (+)-endo-brevicomin in 70% yield and 84.4% e.e.Um homoenolato gerado pela reação de troca telúrio/lítio foi aplicado na síntese enantioseletiva do (+)-endo-brevicomin com 70% de rendimento isolado e 84,4% de e.e.FAPESPCNPqCoordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES

Synthetic organotelluride compounds induce the reversal of Pdr5p mediated fluconazole resistance in Saccharomyces cerevisiae

Background: Resistance to fluconazole, a commonly used azole antifungal, is a challenge for the treatment of fungal infections. Resistance can be mediated by overexpression of ABC transporters, which promote drug efflux that requires ATP hydrolysis. the Pdr5p ABC transporter of Saccharomyces cerevisiae is a well-known model used to study this mechanism of antifungal resistance. the present study investigated the effects of 13 synthetic compounds on Pdr5p.Results: Among the tested compounds, four contained a tellurium-butane group and shared structural similarities that were absent in the other tested compounds: a lateral hydrocarbon chain and an amide group. These four compounds were capable of inhibiting Pdr5p ATPase activity by more than 90%, they demonstrated IC50 values less than 2 M and had an uncompetitive pattern of Pdr5p ATPase activity inhibition. These organotellurides did not demonstrate cytotoxicity against human erythrocytes or S. cerevisiae mutant strains (a strain that overexpress Pdr5p and a null mutant strain) even in concentrations above 100 mu M. When tested at 100 mu M, they could reverse the fluconazole resistance expressed by both the S. cerevisiae mutant strain that overexpress Pdr5p and a clinical isolate of Candida albicans.Conclusions: We have identified four organotellurides that are promising candidates for the reversal of drug resistance mediated by drug efflux pumps. These molecules will act as scaffolds for the development of more efficient and effective efflux pump inhibitors that can be used in combination therapy with available antifungals.Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)University of São Paulo through the NAP-CatSinQ (Research Core in Catalysis and Chemical Synthesis)Univ Fed Rio de Janeiro, CCS, Inst Microbiol Paulo Goes, Dept Microbiol Geral,Lab Bioquim Microbiana, Rio de Janeiro, RJ, BrazilUniv São Paulo, Inst Quim, Dept Quim Fundamental, São Paulo, BrazilInst Fed Educ Ciencia & Tecnol Rio de Janeiro IFR, Rio de Janeiro, RJ, BrazilUniversidade Federal de São Paulo UNIFESP, Inst Ciencias Ambientais Quim & Farmaceut, São Paulo, BrazilUniversidade Federal de São Paulo UNIFESP, Inst Ciencias Ambientais Quim & Farmaceut, São Paulo, BrazilFAPERJ: E-26/111.338/2013FAPESP: 2005/59572-7FAPESP: 2008/55401-1FAPESP: 2010/17228-6FAPESP: 2011/03244-2FAPESP: 2011/11613-8FAPESP: 2012/17093-9CNPq: 470360/2012-7Web of Scienc

Selenium and tellurium chemistry: historical background

In this paper we present a general survey on the history of the selenium and tellurium chemistry in Brazil and worldwide

Influence of different protecting groups on the regioselectivity of the hydrotelluration reaction of hydroxy alkynes

The influence of protecting groups on the synthesis of regio- and stereodefined vinyl tellurides derived from the reaction of BuTeNa and propargylic- or homo-propargylic alcohols showed that TIPS silyl ether is useful as a regiodirecting group. The application of the methodology to the synthesis of a fragment of (±)-Seselidiol, a natural product, demonstrated the applicability of the new methodology

(Z)-2-[(4-Methyl­phen­yl)sulfon­yl]-1,2-diphenyl­ethene­selenol

In the title compound, C21H18O2SSe, the dihedral angle between the cis phenyl rings is 64.3 (1)° and those between the toluene and the phenyl rings are 21.1 (2) and 72.0 (1)°, respectively. An intra­molecular Se—H⋯O hydrogen bond occurs. In the crystal, mol­ecules are connected by C—H⋯O hydrogen bonds and weak C—H⋯π inter­actions help to consolidate the crystal packing

ANÁLISE DO MERCHANDISIG E MENSAGEM SUBLIMINAR NO DESENHO BOB ESPONJA

O meio de comunicação no veículo da televisão popularizou-se de tal forma a atingir as mais diversas classes sociais em todo mundo. O conteúdo apresentado consegue intervir no cotidiano social, não apenas como instrumento de lazer e cultura, mas como influência ideológica. Para perceber a influência da televisão no público infantil, foi escolhido para análise o desenho animado Bob Esponja. Carregado de uma ideologia massiva, com personagens divertidos e inseridos em histórias do cotidiano da sociedade atual, o desenho exibido em rede aberta diariamente, conquistou um público telespectador significativo. Também é verificado no desenho uma ambigüidade acerca da produção cultural midiática, porque ao mesmo tempo em que conscientiza, pode servir para a alienação, ou seja, pode confundir e servir para a escamoteação da realidade. Os episódios podem transmitir uma visão deformada do trabalho e da forma de vida dos personagens, levando a passividade crítica. Os artíficios usados para construir a influência ideológica do desenho se constroem na forma de merchandising. Nos episódios, o merchandising apresenta modelos de conduta a ser seguido. As mensagens subliminares também são encontradas no conteúdo e funcionam como simples mensagens que se instalam no subconsciente para serem ativadas no tempo certo