In situ generation of n-butanethiol and its reaction with electron-deficient olefines

n-Butanethiol is generated in situ by sequential addition of n-butyllithium and water to elemental sulfur. The n-butanethiol formed was reacted with electron-deficient olefines to give Michael-type addition products in good yields. The method avoids the manipulation of the bad-smelling n-butanethiol.

In vitro activity of compounds isolated from Piper crassinervium against Trypanosoma cruzi

This study describes the antichagasic potential of five compounds isolated from leaves of Piper crassinervium (Piperaceae). Two prenylated benzoic acid derivatives, one prenylated hydroquinone and two flavanones, were evaluated. The in vitro trypanocidal activity was determined against epimastigote forms of Trypanosoma cruzi (Y strain), the etiologic agent of Chagas disease. The most active compound was the prenylated hydroquinone [1,4-dihydroxy-2-(3(0),7(0)-dimethyl-1(0)-oxo-2(0)-E,6(0)-octadienyl)benzene] with an IC(50) value of 6.10 g mL(-1), which was in the same order of activity if compared with the positive control benznidazole (IC(50) = 1.60 mu g mL(-1)). This is the first report of trypanocidal activity for prenylated hydroquinone and benzoic acid derivatives.

Absolute Configuration and Selective Trypanocidal Activity of Gaudichaudianic Acid Enantiomers

Gaudichaudianic acid, a prenylated chromene isolated from Piper gaudichaudianum, has been described as a potent trypanocidal compound against the Y-strain of Trypanosoma cruzi. We herein describe its isolation as a racemic mixture followed by enantiomeric resolution using chiral HPLC and determination of the absolute configuration of the enantiomers as (+)-S and (-)-R by means of a combination of electronic and vibrational circular dichroism using density functional theory calculations. Investigation of the EtOAc extract of the roots, stems, and leaves from both adult specimens and seedlings of P. gaudichaudianum revealed that gaudichaudianic acid is biosynthesized as a racemic mixture from the seedling stage onward. Moreover, gaudichaudianic acid was found exclusively in the roots of seedlings, while it is present in all organs of the adult plant. Trypanocidal assays indicated that the (+)-enantiomer was more active than its antipode. Interestingly, mixtures of enantiomers stowed a synergistic effect, with the racemic mixture being the most active.

Synthesis of substituted alpha,beta-unsaturated delta-lactones from vinyl tellurides

A new approach for the synthesis of alpha,beta-unsaturated delta-lactones, a unit present in many natural products with interesting biological activities is described. The approach was based on the use of a vinyl telluride, and it is complementary to the methods using ring-closing metathesis. The sequence was performed in good overall yield with retention of the Z-double bond geometry. (C) 2011 Elsevier Ltd. All rights reserved.

The effect of calcium salts on the viscosity and adsorption behavior of xanthan

The effect of CaCl(2), Ca(NO(3))(2), CaSO(4), CaCO(3) and Ca(3)(PO(4))(2) on the flow behavior of xanthan gum solutions was investigated. Regardless the concentration and type of calcium salt used, xanthan solutions presented pseudoplastic behavior. The soluble salts (CaCl(2) and Ca(NO(3))(2)) induced the disordered state in the xanthan chains at concentration of 1.0 g/L or 10 g/L, decreasing the flow consistency index (K) values. At 100 g/L soluble salts K values were similar to those found for pure xanthan solutions, whereas at the same concentration of insoluble particles the K values increased 20%. The adsorption of xanthan gum onto Si/SiO(2) surfaces in the presence of calcium salts was investigated by ellipsometry and atomic force microscopy (AFM). The adsorbed layer of xanthan onto Si/SiO(2) consisted of two regions: (i) a thin acid resistant sublayer, where xanthan chains were like highly entangled fibers and (ii) a thick upperlayer, whose morphology was calcium salt dependent. (C) 2010 Elsevier Ltd. All rights reserved.

Tellurium in organic synthesis: a new approach to trisubstituted gamma-butyrolactones with trans-trans relative stereochemistry. Total enantioselective synthesis of (-)-Blastmycinolactol, (+)-Blastmycinone, (-)-NFX-2, and (+)-Antimycinone

The total synthesis of (-)-Blastmycinolactol, (+)-Blastmycinone, (-)-NFX-2, and (+)-Antimycinone was accomplished in few steps in high yields and ee, starting from enantiomerically enriched (S)-Z-vinylic hydroxytellurides. (C) 2010 Published by Elsevier Ltd.

Effects of a high fat diet on liver mitochondria: increased ATP-sensitive K(+) channel activity and reactive oxygen species generation

High fat diets are extensively associated with health complications within the spectrum of the metabolic syndrome. Some of the most prevalent of these pathologies, often observed early in the development of high-fat dietary complications, are non-alcoholic fatty liver diseases. Mitochondrial bioenergetics and redox state changes are also widely associated with alterations within the metabolic syndrome. We investigated the mitochondrial effects of a high fat diet leading to non-alcoholic fatty liver disease in mice. We found that the diet does not substantially alter respiratory rates, ADP/O ratios or membrane potentials of isolated liver mitochondria. However, H(2)O(2) release using different substrates and ATP-sensitive K(+) transport activities are increased in mitochondria from animals on high fat diets. The increase in H(2)O(2) release rates was observed with different respiratory substrates and was not altered by modulators of mitochondrial ATP-sensitive K(+) channels, indicating it was not related to an observed increase in K(+) transport. Altogether, we demonstrate that mitochondria from animals with diet-induced steatosis do not present significant bioenergetic changes, but display altered ion transport and increased oxidant generation. This is the first evidence, to our knowledge, that ATP-sensitive K(+) transport in mitochondria can be modulated by diet.

Minor sesquiterpenes from the volatile oil from leaves of Guarea guidonia Sleumer (Meliaceae)

The essential oil from leaves of Guarea guidonia was subjected to chromatographic separation procedures to afford nine sesquiterpenes; two of them are new eudesmane derivatives. The chemical structures of the obtained compounds were characterised by spectrometric analysis, mainly mass spectrometry and NMR.

Complexation of the anti-Trypanosoma cruzi drug benznidazole improves solubility and efficacy

The ruthenium complex,trans-[Ru(Bz)(NH3)(4)SO2](CF3SO3)(2) 1, Bz = benznidazole (N-benzyl-2-(2-nitro-1H-imidazol-1-yl)acetamide), is more hydrosoluble and more active (IC50try/1 h = 79 +/- 3 mu M) than free benznidazole 2 (IC50try/1 h > 1 mM). 1 also exhibits low acute toxicity in vitro (IC50macrophages > 1 mM) and in vivo (400 mu mol/kg < LD50 < 600 mu mol/kg) and the formation of hydroxylamine is more favorable in 1 than in 2 by 9.6 kcal/mol. In murine acute models of Chagas` disease, 1 was more active than 2 even when only one dose was administrated. Moreover, 1 at a thousand-fold smaller concentration than the considered optimal dose for 2 (385 mu mol/kg/day = 100 mg/kg/day), proved to be sufficient to protect all infected mice, eliminating the amastigotes in their hearts and skeletal muscles as observed in H&E micrographics.

Experimental Chemotherapy against Trypanosoma cruzi Infection Using Ruthenium Nitric Oxide Donors

The ruthenium NO donors of the group trans-[Ru(NO)(NH(3))(4)L](n+), where the ligand (L) is N-heterocyclic H(2)O, SO(3)(2 -), or triethyl phosphite, are able to lyse Trypanosoma cruzi in vitro and in vivo. Using half-maximal (50%) inhibitory concentrations against bloodstream trypomastigotes (IC(50)(try)) and cytotoxicity data on mammalian V-79 cells (IC(50)(V79)), the in vitro therapeutic indices (TIs) (IC(50)(V79)/IC(50)(try)) for these compounds were calculated. Compounds that exhibited an in vitro TI of >= 10 and trypanocidal activity against both epimastigotes and trypomastigotes with an IC(50)(try/epi) of <= 100 mu M were assayed in a mouse model for acute Chagas` disease, using two different routes (intraperitoneal and oral) for drug administration. A dose-effect relationship was observed, and from that, the ideal dose of 400 nmol/kg of body weight for both trans-[Ru(NO)(NH(3))(4)isn](BF(4))(3) (isn, isonicotinamide) and trans-[Ru(NO)(NH3) 4imN](BF4) 3 (imN, imidazole) and median (50%) effective doses (ED50) of 86 and 190 nmol/kg, respectively, were then calculated. Since the 50% lethal doses (LD(50)) for both compounds are higher than 125 mu mol/kg, the in vivo TIs (LD(50)/ED(50)) of the compounds are 1,453 for trans-[Ru(NO)(NH(3))(4)isn](BF(4))(3) and 658 for trans-[Ru(NO)(NH(3))(4)imN](BF(4))(3). Although these compounds exhibit a marked trypanocidal activity and are able to react with cysteine, they exhibit very low activity in T. cruzi -glycosomal glyceraldehyde-3-phosphate dehydrogenase tests, suggesting that this enzyme is not their target. The trans-[Ru(NO)(NH(3))(4)isn](BF(4))(3) and trans-[Ru(NO)(NH(3))(4)imN](BF(4))(3) compounds are able to eliminate amastigote nests in myocardium tissue at 400-nmol/kg doses and ensure the survival of all infected mice, thus opening a novel set of therapies to try against trypanosomatids.

Análise do ambiente informacional dos tomadores de decisão do mercado de capitais

Dissertação apresentada ao Programa de Mestrado em Administração da Universidade Municipal de São Caetano do Sul - USCS

Panorama comunicacional da avaliação institucional nas IES do ABC Paulista

Dissertação apresentada ao Programa de Mestrado em Comunicação da Universidade Municipal de São Caetano do Sul - USCS

Tempo e estratégias de busca na Web

O tempo e a temporalidade tornaram-se questões fundamentais na contemporaneidade com o advento e desenvolvimento das redes digitais de comunicação em toda sua abrangência e complexidade. A análise do conceito de tempo cronológico, contraposto ao tempo vivido, esclarece os pressupostos temporais acerca de nossa pesquisa sobre estratégias de busca na Web. A Web tem sido utilizada amplamente por seus usuários para a busca e seleção de informações, resultando em um de seus principais empregos como suporte para atividades acadêmicas e profi ssionais. Este trabalho apresenta, um estudo sobre as estratégias de busca de informações na Web, visando analisar e comparar os resultados de uma pesquisa exploratória com estudo similar realizado na Universidade de Telaviv. Apresentam- se nove formas possíveis de buscas e como elas foram utilizadas nos estudos comparados. Elias Estevão Goulart,Regina Rossetti e Annibal Hetem Junior* Tempo e estratégias de busca na Web Palavras-chave: Tempo e comunicação Estratégias de busca Web e comunicação Como resultado, são apresentadas as mais efetivas e sugere-se melhor treinamento dos usuários para o conhecimento das técnicas apresentadas.

Caminhos cruzados no mundo digital: a hipermídia e a memória

Esse artigo aborda as propostas de convergência da hipermídia com a memória, a narratividade oral, as histórias de vida e o patrimônio cultural local a partir da elaboração, das funcionalidades e das aplicações do sistema HiperMemo: acervo hipermídia de memórias da Universidade Municipal de São Caetano do Sul – USCS. Tem-se por objetivo apresentar o sistema HiperMemo, desenvolvido no Núcleo de Pesquisadores de Memórias do ABC da USCS, como elemento de convergência entre as novas tecnologias digitais (a linguagem hipermídia), a memória e o patrimônio cultural.

WEB & arte: desafios comunicacionais na educação

Dissertação apresentada ao Programa de Mestrado em Comunicação da Universidade Municipal de São Caetano do Sul - USCS