Evandro Luiz Dall'Oglio

Variação anual do rendimento e composição química dos componentes voláteis da Siparuna guianensis Aublet

This work describes the volatile composition obtained by hidrodistillation of fresh leaves of Siparuna guianensis Aublet collected from Cuiaba (MT), Brazil. The composition of DCM extract of hydrolate was determined by GC-MS analysis and the results showed that the specie present a range of components according to their phenology and period of the leaves were collects. The highest volatile components yield was obtained during the reproductive period and the principal compound was the siparunone.

Use of heterogeneous catalysts in methylic biodiesel production induced by microwave irradiation

The effect of different heterogeneous catalysts on the microwave-assisted transesterification of sunflower oil for the production of methylic biodiesel in a monomode microwave reactor is described. The experiments were carried out at 70 oC with a 16:1 methanolsunflower oil molar ratio and different heterogeneous basic and acidic catalysts. The results showed that the microwave-heated reactions occur up to four times faster than those carried out with conventional heating. The reactions were performed with 24 catalysts; pure calcium oxide (CaO) and potassium carbonate, either pure or supported by alumina (K2CO3/Al2O3), were the most efficient catalysts.

Measurement of Dielectric Properties and Microwave-Assisted Homogeneous Acid-Catalyzed Transesterification in a Monomode Reactor

Microwave heating technology is dependent on the dielectric properties of the materials being processed. The dielectric properties of H2SO4, H3PO4, ClSO3H, and H3CSO3H were investigated in this study using a vector network analyzer in an open-ended coaxial probe method at various temperatures. Phosphoric and sulfuric acids presented higher loss tangents in the frequency range 0.3-13 GHz, reflecting greater mobility of the ions and counterions. The acids were employed as catalysts in microwave-assisted homogeneous transesterification reactions for the production of methylic and ethylic biodiesel. The effects of catalyst concentration, alcohol to oil molar ratio, and irradiation time on biodiesel conversions were investigated. The results showed a significant reduction in the reaction time for microwave-assisted transesterification reactions as compared to times for conventional heating. Also, despite its higher loss tangent, it was observed that H3PO4 leads to lower conversion to biodiesel, which can be explained by its lower carbonyl protonation capacity.

Acosmium genus: chemical composition and pharmacological potential

The genus Acosmium is composed by c.a. 17 species, with geographic distribution from southeastern Mexico to Northwestern Argentina. Most of the species, however, are located in Brazil. A. dasycarpum, A. panamense, A. subelegans are used in folk medicine to treat several ailments. A search in the literature regarding the chemical and pharmacological aspects of these plants indicates cytotoxic activity, antithermal and hypoglycemic effects, as well as their use to treat Alzheimers disease and CNS disorders. Phytochemical investigations resulted mainly in the isolation of terpenes, caffeic acid, diaza-adamantane and quinolizidines alkaloids as well as pyrones.

TRATAMENTO ELETROQUÍMICO DE EFLUENTE DA PRODUÇÃO DE BIODIESEL USANDO UM ELETRODO DO TIPO ADE: Ti/IrO2-Nb2O5

Carlos H. M. Fernandesa, Marcelo M. Yamasakia, Fernando L. Silvab, Vanessa M. Vasconcelosb, Robson S. Rochab, Marcos R. V. Lanzab,*, Marilza Castilhoa, Evandro L. Dall’Óglioa e Ailton J. Terezoa,* Departamento de Química, Universidade Federal do Mato Grosso, Av. Fernando Corrêa da Costa, 2367, Boa Esperança, 78090600 Cuiabá – MT, Brasil Instituto de Química de São Carlos, Universidade de São Paulo, 13560-970, São Carlos – SP, Brasil

Acute and subchronic antihyperglycemic activities of Bowdichia virgilioides roots in non-diabetic and diabetic rats.

Aim: The present study was undertaken to evaluate the acute and subchronic antihyperglycemic effects of methanolic extract of Bowdichia virgilioides root bark of B. virgilioides in streptozotocin (STZ)-induced diabetic rats. Materials and Methods: The extract (100, 250 or 500 mg/kg) was orally administered to male Wistar diabetic (STZ, 42 mg/kg i.v.) and non-diabetic rats into two main protocols: (i) subchronic experiments, where animals were treated for 21 days with B. virgilioides extract and the following parameters were evaluated: Body weight, fluid and food intake (determined daily), urinary glucose and urea (every 3 days) and glycemia (every 5 days). At the end of the experimental period, skeletal muscles (extensor digitorum longus [EDL] and soleus), retroperitoneal and epididymal white adipose tissues were collected and weighed; liver samples were used for the determination of the lipid and glycogen contents; (ii) acute experiments, which evaluated the alterations on fasting and post-prandial glycemia and on glucose tolerance using the oral glucose tolerance test (OGTT). Results: In subchronic experiments, the treatment with B. virgilioides extract did not change any parameter evaluated in diabetic and non-diabetic animals. On fasting and post-prandial glycemia, the extract treatment did not promote changes in the glycemia values in diabetic or non-diabetic animals. In OGTT, the treatment with 500 mg/kg B. virgilioides extract reduced the hyperglycemia peak after a glucose overload, when compared with non-treated diabetic animals, resulting in a lower area under curve. Conclusion: The results of our work indicate that B. virgilioides root extract promotes an acute antihyperglycemic effect in STZ-diabetic rats; this effect probably occurs through an inhibition of the intestinal glucose absorption. The continuity of the research is necessary to elucidate these possibilities.

Estudo Químico das Folhas de Acosmium Dasycarpum (Vogel) Yakovlev

Acosmium dasycarpum e uma planta exclusiva do cerrado. Conhecida como perobinha do campo. Apesar de amplamente utilizada pela populacao para o tratamento de uma serie de enfermidades, pouco se conhece sob o ponto de vista quimico. Neste trabalho apresentamos o isolamento da catequina, lupeol, isomeros (E)-4-hidroxicinamato de metila (A) e (Z)-4-hidroxicinamato de metila (B), bornesitol e 3-O-B-D-glicopiranosilsitosterol, sendo que a excecao do lupeol, os demais compostos isolados sao ineditos nesta especie.

Diaqua­bis[2,5-dichloro-N-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)benzene­sulfonamidato-κN]zinc(II)

In the title compound, [Zn(C17H14Cl2N3O3S)2(H2O)2], the ZnII ion has a tetrahedral coordination formed by the two N atoms of the sulfonamide groups and the two water molecules. Two inter- and two intramolecular O—H⋯O hydrogen bonds are observed in the crystal structure.

N-(1,5-Dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)-4-methyl­benzene­sulfonamide

In the title compound, C18H19N3O3S, the phenyl ring and the pyrazole ring are twisted with respect to each other by an angle of 49.11 (7)°. The C—N—S—C torsion angle is −122.5 (2)°. The methyl group bonded to the N atom of the pyrazole ring has a large deviation from the mean ring plane of 0.603 (3) Å. One intermolecular N—H⋯O and two non-classical intermolecular C—H⋯O hydrogen bonds are observed in the crystal structure.