Assignment of the absolute configuration at the sulfur atom of thioridazine metabolites by the analysis of their chiroptical properties: the case of thioridazine 2-sulfoxide.

Thioridazine (THD) is a commonly prescribed phenotiazine neuroleptic drug, which is extensively biotransformed in the organism producing as main metabolites sulfoxides and a sulfone by sulfur oxidation. Significant differences have been observed in the activity of the THD enantiomers as well as for its main metabolites, and enantioselectivity phenomena have been proved in the metabolic pathway. Here the assignment of the absolute configuration at the sulfur atom of enantiomeric THD-2-sulfoxide (THD-2-SO) has been carried out by circular dichroism (CD) spectroscopy. The stereoisomers were separated by HPLC on Chiralpak AS column, recording the CD spectra for the two collected enantiomeric fractions. The theoretical electronic CD spectrum has been obtained by the TDDFT/B3LYP/6-31G*, as Boltzmann averaging of the contributions calculated for the most stable conformations of the drug. The comparison of the simulated and experimental spectra allowed the absolute configuration at the sulfur atom of the four THD-2-SO stereoisomers to be assigned. The developed method should be useful for a reliable correlation between stereochemistry and activity and/or toxicity.

Análise qualitativa da presença de mercúrio em cápsulas de amálgama utilizadas / Qualitative analysis of mercury presence in utilized amalgam capsule

Analisou-se quantitativamente a presença ou ausência de resíduos de mercúrio em cápsulas pré-dosadas de amálgama de marcas Degussa, Permite SDI, SSWHITE (Velvalloy Plus) e Vigodent (Pratic NG2) já utilizadas. Utilizou-se para tanto, testes provenientes da química analítica denominado análise por via úmida. Concluiu-se que a cápsula da marca Degussa apresentou resultados negativos e as demais cápsulas testadas apresentaram resultados positivos para a presença de resíduos de mercúrio

The influence of different grades of rosins and hydrogenated resins on the powder-liquid ratio of grossman cements / A influência de diferentes graus de resinas e resinas hidrogenadas em líquido-pó razão de cimentos Grossman

In this study, the effect of different grades of rosin and hydrogenated resin on the setting time of Grossman cement was evaluated. The experiments were carried following the American Dental Association Specification number 57 for root canal sealers. For this analysis, different Grossman cement powders were preparedusing different grades of rosin (X, WW and WG) and hydrogenated resin (Staybelite and Staybelite ester 10). The pH and electrical conductance of the different grades of rosin and hydrogenated resin were evaluated. The phisicochemical properties of the Grossman cements obtained with the differnt grades of rosin and hydrogenated resins interfere in the powder-liquid ratio of the cements. The sealers obtained with the hydrogenated resin showed a higher powder-liquid ratio

Evaluation of chelating action of EDTA in association with dakin's solution / Avaliação da ação quelante do EDTA em associação com a solução de Dakin

Three methods were used to study the chelating effect of EDTA, associated or not with 0.5 percent sodium hypochlorite (Dakin's solution). The results showed that: 1) aqueous EDTA, associated or not with Dakin's solution, is capable of chelating metallic ions; 2) EDTA and EDTA + Dakin's solution are capable of chelating calcium ions; 3) aqueous EDTA, as well as EDTA + Dakin's solution, decalcify dentin, decreasing its Vicker's microhardness; 4) the chelating action of EDTA is not inactivated when associated with Dakin's solution

Tensäo superficial de algumas soluçöes irrigantes de canais radiculares / Surface tension of root canal irrigating solution

Estudou-se a tensäo superficial de várias soluçöes auxiliares de instrumentaçäo de canais radiculares por meio do método da ascensäo capilar. O Lauril sulfato de sódio a 0.1 por cento apresentou a mais baixa tensäo superficial das soluçöes estudadas. A associaçäo de tensoativos ao EDTA reduz sensivelmente sua tensäo superficial. O líquido de Dakin apresenta uma tensäo superficial de 31,34 din/cm, que o posiciona como uma boa soluçäo de contato

Verificaçäo do teor de cloro ativo de diferentes marcas de líquido de Dakin encontrados no mercado / Determination of active chloride content in different comercial brands of Dakin's fluid

Verificou-se por meio da titulometria, o teor de cloro ativo, de 16 marcas de líquido de Dakin encontrada no mercado. Das amostras testadas, 6 estavam com teor de cloro ativo aceitável, ou seja , entre 0.64 a 0.40 por cento. Dez amostras apresentavam-se com teor de cloro abaixo de 0.40 por cento. A embalagem em plástico foi a predominante e entre elas, as transparentes