IQ - Artigos publicados em periódicos

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The crystal structure of 1 (3,4-dimethoxyphenyl) – 2 -(thiophenoxy) - 1-propanone, a platelet activating factor (paf-acether) antagonist
(1995) Lariucci, Carlito; Homar, Leon Ítalo Brasil; Ferri, Pedro Henrique; Santos, Lourivaldo Silva
Isolamento de produtos naturais por cromatografia de gotas em contracorrente
(1996) Vieira, Ivo Jose Curcino; Lião, Luciano Morais; Velozo, Eudes da Silva; David, Valmir; Vieira, Paulo Cezar; Silva, Maria Fatima das Gracas Fernandes da; Fernandes, Joao Batista; Rodrigues Filho, Edson
Droplet countercurrent chromatography has shown to be a useful technique in the isolation of natural products mostly the polar ones. ln this paper however, we discuss the use of this technique in the isolation of non polar compounds from crude extract of plants belonging to the families Sapotaceae, Rutaceae, Simaroubaceae and Hippocrateaceae.
The diels-alder reaction witH O-2,3-Dimethylene-1,4-Naphtoquinone: a useful intermediate for the synthesis of b ring of anthracyclinones
(1996) Ferreira, Vítor F.; Pinti, Antonio V.; Pintob, Maria do Carmo F. R.; Santos, Suzana da Costa
This work describes the attempt to use the diene ortho-2,3-dimetbylene-l ,4-naphthoquinone (3) in a Diels-Alder reaction with typical dienophiles. The intennediate 3 is useful for the synthesis ofthe anthracyclinone skeleton by a convergent route to the B ring. The reactions failed to gíve the desired Diels-Alder adduct in a good yield, but instead led to a spiro-dimer 9 which was recently described as a trypanocide agent. Among the by-products generated in these reactions it was possible to isolate and cbaracterize a new heterocyclic compound 13.
Estudo comparativo entre alguns benzalpiruvatos-fenil substituído de lantanídeos e ítrio no estado sólido
(1999) Fernandes, Nedja Suely; Carvalho Filho, Marco Aurélio da Silva; Leles, Maria Inês Gonçalves; Ionashiro, Massao
In the present work the thermal decomposition step of some lanthanides and yttrium compounds involving different ligand phenyl-substituted derivatives of benzylidenepyruvate was appraised by thermogravimetry (TG). A correlation about the metal ions content was made by comparision of the results obtained by TG and EDTA complexometry.
Preparation and thermal behavior of mixture of basic carbonate and 4-dimethylaminocinnamylidenepyruvate with lanthanides (III) and yttrium (III) in the solid state
(1999) Leles, Maria Ines Gonçalves; Melios, Cristo Bladimiros; D’Assunção, Lázaro Moscardini; Ionashiro, Massao
Solid Ln-OHCO3-DMCP compounds, where Ln represents lanthanides (III) and yttrium (III) ions and DMCP is the anion 4-dimethylaminocinnamylidenepyruvate, have been prepared. Thermogravimetry, derivative thermogravimetry (TG, DTG), differential scanning calorimetry (DSC), x-ray diffraction powder patterns and elemental analysis have been used to characterize the compounds. The thermal stability as well as the thermal decomposition of these compounds were studied using an alumina crucible in an air atmosphere.
Thermal behavior studies of solid state lanthanide and yttrium (III) compounds of cinnamylidenepyruvic acid in the atmosphere of air
(1999) Oliveira, José Dilson Silva de; Leles, Maria Inês Gonçalves; D’Assunção, Lazaro Moscardini; Melios, Cristo Bladimiros; Ionashiro, Massao
Solid state Ln-CP compounds, where Ln represents trivalent lanthanides (except for promethium) and yttrium, and CP is cinnamylidenepyruvate, were prepared. Thermogravimetry (TG), differential scanning calorimetry (DSC), X-ray diffraction powder patterns and complexometry were used to characterize and to study the thermal behaviour of these compounds. The results provide information about dehydration, thermal stability and thermal decomposition.
Thermal behavior studies of solid state compounds of 4-dimethylaminocinnamylidenepyruvate with alkali e hearth metahls, except beryllium and radium
(2000) Schnitzler, Egon; Costa, Wilson; Melios, Cristo Bladimiros; Leles, Maria Ines Gonçalves; Ionashiro, Massao
Solid state compounds of general formula M(DMCP)2.nH2O, where M represents Mg, Ca, Sr, Ba, and DMCP is 4-dimethylaminocinnamylidenepyruvate, and n = 1, except for Ca, where n = 2.5, have been prepared. Thermogravimetry, derivative thermogravimetry (TG, DTG), differential scanning calorimetry (DSC), X-ray diffraction powder patterns and complexometry were used to characterize and to study the thermal decomposition of these compounds.
Controlling factors determining the selective HSCN addition to double bonds and their application to the Synthesis of 7-Isothiocyano-7,8-α-Dihydro-Bisabolene
(2001-08) Oliveira, Cecília Maria Alves de; Silva, Cleuza Conceição da; Collins, Carol Hollingworth; Marsaioli, Anita Jocelyne
The reactivity of terminal and trisubstituted double bonds of monoterpenes with HSCN has been examined by GC giving evidence that kinetics is responsible for the chemoselective addition to terminal double bonds in terpenes. The results show that the addition to the terminal double bond is about 17 times faster than for trisubstituted double bonds and that the presence of the first SCN group in the molecule prevents a second addition. The presence of a hydroxyl or methoxy group in the molecule, decreases the reaction kinetics. Based on these kinetic experiments a two steps synthesis of the natural product 7-isothiocyano-7,8-dihydro- -bisabolene using bisabolol as starting material, was planned and successfully accomplished.
Estudo da estabilidade térmica de óleos e gorduras vegetais por TG/DTG e DTA
(2002) Faria, Elaine Alves de; Leles, Maria Inês Gonçalves; Ionashiro, Massao; Zuppa, Tatiana de Oliveira; Antoniosi Filho, Nelson Roberto
Vegetal oils and fats are very useful in the food and chemist industry, they have demanded from researchers and technicians analytical methods able to estimate the conditions for their processing and storage. The thermal stability of vegetal oils is a main determinant in recognizing their value. The goal of this study is to evaluate the thermal stability of vegetable oils and fats extracted from the seeds of plants from Brazilian cerrado (araticum, babassu, Brazilian wine-palm, guariroba, murici). The thermal stability was evaluated by TG/DTG and DTA techniques, in a temperature range from 30º to 650º, under nitrogen atmosphere, and at a heating rate 10º C min-1. The TG/DTG and DTA used were efficient and fast in the determination of oils and fasts studied.
Identificação de pigmentos naturais utilizando-se cromatografia em papel
(2002) Okumura, Fabiano; Soares, Márlon Herbert Flora Barbosa; Cavalheiro, Éder Tadeu Gomes
The use of natural dyes to demonstrate principles of paper chromatography is proposed. Extraction of the coloring compounds were performed in order to obtain the aglycone form of the anthocyanins present in the crude extracts. Separations were carried out on chromatographic paper with BAW (butanol/acetic acid/water) as mobile phase and the results compared with literature data. The crude extracts were obtained from Tibouchina granulosa, Rododhendron simsii, Impatiens walleriana flowers which are wildely found in Brazil and Phaseolus vulgaris L. grains skin which is the principal ingredient of the world famous “feijoada”. Such species were chosen in order to attract the students attention since they are present in their quotidian, in agreement with the new proposals for Brazilian education.
Ácidos orgânicos: dos primórdios da química experimental à sua presença em nosso cotidiano
(2002-05) Fiorucci, Antonio Rogério; Soares, Márlon Herbert Flora Barbosa; Cavalheiro, Éder Tadeu Gomes
Due to the very little socio-cultural contextualization available in high-school textbooks concerning organic substances and that these are commonly addressed only on the aspect related to the nomenclature of organic functions, the present paper aims at showing the importance of organic acids as substances present in daily life, as well as the relationship between the discovery of these acids and chemistry development itself. Thus, this paper has the goal of contributing subsidies that help teachers attract the attention of students in high-school classes.
Antifungal properties of brazilian cerrado plants
(2002-09) Souza, Lúcia Kioko Hasimoto e; Oliveira, Cecília Maria Alves de; Ferri, Pedro Henrique; Santos, Suzana Costa; Oliveira Júnior, Juldásio Galdino de; Miranda, André Thiago Borges; Lião, Luciano Morais; Silva, Maria do Rosário Rodrigues
Ethanolic extracts from leaves of Hyptis ovalifolia, H. suaveolens, H. saxatilis, Hyptidendrum canum, Eugenia uniflora, E. dysenterica, Caryocar brasiliensis and Lafoensia pacari were investigated for their antifungal activity against dermatophytes. The most effective plants were H. ovalifolia and E. uniflora, while Trichophyton rubrum was the most sensitive among the four dermatophytes species evaluated. This study has demonstrated antifungal properties of Brazilian Cerrado plant extracts in “in vitro” assays.
Análise morfométrica do epitélio de revestimento do filamento branquial do guaru (Poecilia vivipara) exposto a frações do extrato da folha e da casca do caule de pequi (Caryocar braziliensis)
(2002-12) Silva, Luciana Damacena; Rosa, Eliane Vieira; Santos, Suzana Costa; Sabóia-Morais, Simone Maria Teixeira de
Análise morfométrica das células de cloro de Poecilia vivipara expostas a frações da folha e da casca do caule de Caryocar brasiliensis
(2003) Silva, Luciana Damacena; Nascimento, Valdirene do; Santos, Suzana Costa; Morais, José Oscar Rodrigues de; Sabóia-Morais, Simone Maria Teixeira de
Fractions of Caryocar brasiliensis leaf and bark, tested as molluscicidal, fought the intermediary host of schistosomiasis. The ecological niche of this mollusk is related to water sources. Besides this, a fungitoxic action of the ethyl-acetate fraction (leaf) was verified, exhibiting high activity towards Paracoccidioides brasiliensis. The gill epithelium of Poecilia vivipara (Cyprinodontiformes, Poeciliidae) was used to test the toxicity of these fractions to animal cells. Quantitative analyses demonstrated a decrease in the density of chloride cells exposed to the leaf fractions and an increase in those exposed to bark fractions. The leaf and bark fractions induced a decrease in the area of the chloride cells (CC) in the gill filament. The perimeter of the CC did not suffer significant changes in face of these fractions. The aqueous fraction of the leaf is more toxic to the guaru. Bark fractions are less debilitating, and can be employed in the control of cell populations, showing high efficacy at it.
A importância da vitamina C através dos tempos
(2003-05) Fiorucci, Antonio Rogério; Soares, Márlon Herbert Flora Barbosa; Cavalheiro, Éder Tadeu Gomes
The first synthesis in the laboratory of a vitamin was carried out 70 years ago. This vitamin, ascorbic acid, had an undisputable importance in society before and after the elucidation of its chemical structure and its preparation in the laboratory. This paper presents scientific, historic and everyday aspects of vitamin C, attempting to explore chemical and biological concepts in a contextualized way, according to the National Curricular Parameters. Information is provided with the goal of being a basis for the chemistry teacher to propose an interdisciplinary project related to vitamin C, together with teachers of other subjects.
Síntese do isobutileno e seu emprego em reações de esterificação: propostas de aulas práticas de química orgânica para a graduação
(2003-06) Cunha, Silvio do Desterro; Lião, Luciano Morais; Bonfim, Ricardo Rodrigues; Bastos, Rodrigo da Mota; Monteiro, Ana Paula de Melo; Alencar, Kelly S.
An experiment for the synthesis of isobutylene from tert-butanol dehydratation using oxalic acid as catalyst, followed by preparations of tert-butyl benzoate and tert-butyl cinnamate is described. The synthesis are simple, requiring two periods of 4 hours and are suitable for undergraduate organic chemistry experimental courses.
Chemical composition and antifungal activity of the essential Oil of hyptis ovalifolia benth
(2004) Oliveira, Cecília Maria Alves de; Silva, Maria do Rosário Rodrigues; Kato, Lucília; Silva, Cleuza Conceição da; Ferreira, Heleno Dias; Souza, Lucia Kioto de
The leaves of Hyptis ovalifolia Benth. (Lamiaceae) were subjected to hydrodistillation and the resulting volatiles were investigated by GC/MS. The main constituent representing 60% of the essential oil was isolated by column chromatography and identified by spectroscopic methods as (R)-6-[(Z)-1-heptenyl]-5,6-dihydro-2H-pyran-2-one (1). This compound showed strong in vitro activity against four dermatophyte fungi Microsporum canis, Microsporum gypseum, Tricophyton mentagrophytes, and Tricophyton rubrum (a total of 60 strains) with a minimal inhibitory concentration observed in the range of 125-7.8 μg mL-1.
Júri químico: uma atividade lúdica para discutir conceitos químicos
(2005-05) Oliveira, Alessandro Silva de; Soares, Márlon Herbert Flora Barbosa
Chemical Jury: A Ludic Activity for Discussing Chemical Concepts – This paper presents a ludic activity to be carried out in the classroom and consists in the setting of a simulated jury. The class is divided into three distinct groups. The first group defends a water bottler, the second group, a battery plant and the third acts as the jury. The students personify the functions of the defense lawyer, prosecuting attorney and several witnesses. The teacher personifies the judge of the activity and decides who, in the end, contaminated the fictional city of Nucleopolis. The work also discusses the ludic function as a tool for cognitive development
Determination of fluconazole in serum and amniotic fluid of rats by gaschromatography/ mass spectometry (GC/MS)
(2005-06) Lima, Dione Marçal; Nunes Júnior, Guilhermino Pereira; Ferri, Pedro Henrique; Santos, Suzana Costa
Rats treated with oral dose of 100 mg/kg of fluconazole during pregnancy had their serum and amniotic fluid quantified for this drug using a GC/MS method. Fluconazole was extracted with ethyl acetate from samples and analysed by a GC-MS Shimadzu QP5050A system using a CBP-5 fused silica capillary column. Tioconazole was used as internal standard. Calibration curve was linear within the range 10.0 – 300.0 μg/mL. The limit of quantification was 0.1 μg/mL and no interference was observed in the blank serum and amniotic liquid. The mean concentrations of the drug in the serum and amniotic fluid were 206.01 ± 105.25 μg/mL and 125.34 ± 65.24 μg/mL, respectively. This procedure showed to be sensitive and efficient enough for the use in teratogenic studies of fluconazole and other azole drugs.
Secagem e fragmentação da matéria seca no rendimento e composição do óleo essencial de capim-limão
(2005-12) Costa, Larissa Corrê do Bonfim; Correa, Ricardo Monteiro; Cardoso, Júlio César Wallwitz; Pinto, Jose Eduardo Brasil Pereira; Bertolucci, Suzan Kelly Vilela; Ferri, José Henrique
In this study the drying and fragmentation conditions of lemongrass leaves were determined, to increase the essential oil yield. Four replications of six treatments were studied with 2 drying methodologies (oven-drying at 40ºC and room temperature using moisture dryer) and 3 fragmentation sizes (powder obtained in mill, 1 cm and 20 cm fragments). The essential oil was extracted in Clevenger’s modified apparatus during 2 hours. The higher essential oil yield and citral content was obtained with the leaves dried under room temperature using moisture dryer, with no significant differences in the fragmentation sizes.

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