• 30ª Reunião Anual: ano 30 da Sociedade Brasileira de Química Editorial

    Mangrich, Antonio Sálvio
  • Síntese e avaliação da propriedade reguladora de crescimento vegetal de compostos indólicos derivados do safrol Artigo

    Marchi, Irineu; Rebelo, Ricardo Andrade; Rosa, Flávia A. Fernandes da; Maiochi, Riceli A.

    Abstract in English:

    The present work describes the use of piperonal, a derivative of the secondary metabolite safrole, for the synthesis of new 5,6-methylenedioxysubstituted indole carboxylic acids structurally related to the indol-3-yl-acetic acid (AIA, I). The route comprises six steps beginning with piperonal with an overall yield of 19%. Compound IX was tested towards its plant growth regulator properties in bioassays specific for auxine activity. The in vitro assays were performed in a germination chamber and were of two types: root growth in germinated seeds of Lactuca sativa, Cucumbis sativus and Raphanus sativus and peciole biotest using Phaseolus vulgaris.
  • Mercury in soils and sediments from gold mining liabilities in Southern Amazonia

    Wasserman, Julio Cesar; Campos, Reinaldo Calixto; Hacon, Sandra de Souza; Farias, Renato A.; Caires, Sandro M.

    Abstract in English:

    The 1980-1990 Amazonian gold rush left an enormous liability that increasingly has been substituted by developing fish aquaculture. This work aimed at the identification of the mercury levels in the environment, associated with fish farms located in the North of Mato Grosso State, Southern Amazon. Sediment and soil samples were analyzed for total organic carbon and total mercury. Results indicate that the chemical characteristics of the sediment largely depend on the management procedures of the fish pond (liming, fish food used and fish population). The soils presented relatively low concentrations when compared with other data from the literature.
  • Desenvolvimento e validação de metodologia analítica para determinação de itraconazol em produtos farmacêuticos por CLAE Artigo

    Cazedey, Edith Cristina Laignier; Azevedo, Roberta de Cássia Pimentel; Silva, Érika de Fátima; Araújo, Magali Benjamim de

    Abstract in English:

    Itraconazole is a synthetic antifungal drug administered orally with a broad spectrum of activity against mycotic infections. The present work consists of the development and validation of analytical methodology for evaluation of itraconazole in pharmaceutical products by high performance liquid chromatography. The separation was made using the reversed-phase column LC-18, acetonitrile/diethylamine 0.05% v/v, 60:40 v/v, pH 8.0 as mobile phase, methanol as solvent and detection and quantification at 254 nm. The results here obtained show that the analytical methodology is accurate, reproducible, robust and linear over the concentration range 8.0-12.0 µg/mL of itraconazole. The method was applied to pharmaceutical capsules containg itraconazole pellets and showed to be efficient, yielding good results.
  • Preparação e caracterização físico-química de complexos de inclusão entre anestésicos locais e hidroxipropil-beta-ciclodextrina Artigo

    Moraes, Carolina Morales; Abrami, Priscila; Gonçalves, Marcos Moisés; Andréo Filho, Newton; Fernandes, Sérgio Antonio; de Paula, Eneida; Fraceto, Leonardo Fernandes

    Abstract in English:

    S(-) Bupivacaine (S(-)BVC) and Lidocaine (LDC) are widely used local anesthetics (LA). Hydroxypropyl beta-cyclodextrin (HP-beta-CD) is used as a drug-carrier system. The aim of this work was to characterize inclusion complexes between LA and HP-beta-CD. The affinity constants determined at different pHs show favourable complexation. The release kinetics experiments showed that S(-)BVC and LDC changed the released profiles in the presence of HP-beta-CD. Nuclear magnetic resonance experiments gave information about the interaction between LA and the cyclodextrin cavity. This study focused on the physicochemical characterization of drug-delivery formulations that come out as potentially new therapeutic options for pain treatment.
  • Análise arqueométrica de cerâmica Tupiguarani da região central do Estado do Rio Grande do Sul, Brasil, usando fluorescência de raios X por dispersão de energia (EDXRF) Artigo

    Bona, Irene Akemy Tomiyoshi; Sarkis, Jorge Eduardo S.; Salvador, Vera Lucia Ribeiro; Soares, André Luis Ramos; Klamt, Sergio Célio

    Abstract in English:

    Energy dispersive X-ray fluorescence methodology (EDXRF) was used to determine Al, Ba, Ca, Cr, Fe, K, Mn, Pb, Rb, S, Si, Sr, Ti, V, Zn in pottery sherds from seven archaeological sites in the central region of Rio Grande do Sul State, Brazil. The potteries' chemical fingerprints from Ijuí River, Ibicuí Mirim River, Vacacaí Mirim River and Jacuí River were identified. Interactions between sites from the Jacuí River, Vacacaí Mirim River and Ibicui Mirim River could have occurred because some samples from these sites are overlapping in a principal component analysis (PCA) graphic. The pottery provenance could be the same.
  • Relação entre transferência de carga e as interações intermoleculares em complexos de hidrogênio heterocíclicos Artigo

    Oliveira, Boaz G.; Araújo, Regiane C. M. U. de

    Abstract in English:

    Hydrogen-bonded complexes formed by the interaction of the heterocyclic molecules C2H4O and C2H5N with HF, HCN, HNC and C2H2 have been studied using density functional theory. The hydrogen bond strength has been analyzed through electron density charge transfer from the proton acceptor to the proton donor. The density charge transfer has been estimated using different methods such as Mulliken population analysis, CHELPG, GAPT and AIM. It has been shown that AIM-estimated charge transfer correlates very well with the hydrogen bond energy and the infrared bathochromic effect of the proton donor stretching frequencies.
  • Tratamento estatístico dos parâmetros da qualidade das águas da bacia do alto curso do Rio das Velhas Artigo

    Nonato, Eliana A.; Viola, Zenilde G. G.; Almeida, Katiane C. B.; Schor, Heloiza H. R.

    Abstract in English:

    Water quality was monitored at the upper course of the Rio das Velhas, a major tributary of the São Francisco basin located in the state of Minas Gerais, over an extension of 108 km from its source up to the limits with the Sabara district. Monitoring was done at 37 different sites over a period of 2 years (2003-2004) for 39 parameters. Multivariate statistical techniques were applied to interpret the large water-quality data set and to establish an optimal long-term monitoring network. Cluster analysis separated the sampling sites into groups of similarity, and also indicated the stations investigated for correlation and recommended to be removed from the monitoring network. Principal component analysis identified four components, which are responsible for the data structure explaining 80% of the total variance of the data. The principal parameters are characterized as due to mining activities and domestic sewage. Significant data reduction was achieved.
  • Urinary 2,5-hexanedione in workers exposed to n-hexane: influence of the sample treatment

    Nolasco, Daniela Magalhães; Gusmão, Andréia; Siqueira, Maria Elisa Pereira Bastos de

    Abstract in English:

    The aim of the present study was to determine 2,5-hexanedione (2,5-HD), a metabolite of n-hexane, by gas chromatography/flame ionization detection in 31 workers exposed to n-hexane after two types of sample pretreatment, i.e., with (total 2,5-HD) and without (free 2,5-HD) acid hydrolysis. The mean urinary 2,5-HD was 0.52 mg/L (free) and 2.88 mg/L (total), this difference being significant (Student t-test, p < 0.05). The differences in the results according to the sample treatment support the need to modify the current Brazilian legislation, which proposes the analysis of 2,5-HD without indicating whether it is the free or total metabolite.
  • Adsorção de íons cobre(II) pela quitosana usando coluna em sistema sob fluxo hidrodinâmico Artigo

    Guinesi, Luciana Simionatto; Esteves, Amanda Alves; Cavalheiro, Éder Tadeu Gomes

    Abstract in English:

    The adsorption of Cu(II) ions from aqueous solution by chitosan using a column in a closed hydrodynamic flow system is described. The adsorption capacities as a function of contact time of copper(II) ions and chitosan were determined by varying the ionic strength, temperature and the flow of the metal solution. The Langmuir model reproduced the adsorption isothermal data better than the Freundlich model. The experimental kinetic data correlate properly with the second-order kinetic reaction for the whole set of experimental adsorption conditions. The rate constants exercise great influence on the time taken for equilibrium to be established by complexation or electrostatic interaction between the amino groups of chitosan and the metal.
  • Avaliação das variáveis analíticas do método de Folin-Ciocalteu para determinação do teor de taninos totais utilizando como modelo o extrato aquoso de folhas de psidium guajava L. Artigo

    Verza, Simone Gasparin; Kreinecker, Maria T.; Reis, Valquíria; Henriques, Amélia T.; Ortega, George González

    Abstract in English:

    The main analytical variables of a modified Folin-Ciocalteu method were studied by UV-Vis and gradient HPLC-PDA methods, using purified (PC) and technical grade (TGC) casein. Rutin and an aqueous extract of Psidium guajava L. leaves were used as models. The best results were ascribed to TGC. Certainly PC bonds the polyphenols of the P. guajava extract better than TGC, but TGC afforded better precision. A lack of specificity occurred when rutin was analyzed together with the P guajava extract. Additional analyses performed with the flavonoid fraction of P. guajava extract by HPLC-PDA had confirmed that casein was able to bind catechin, gallic acid and P. guajava flavonoids in a non-specific way.
  • Determinação da composição isotópica de estrôncio em águas naturais: exemplos de sua aplicação em águas subsuperficiais da zona costeira na região Bragantina-PA Artigo

    Bordalo, Adriana Oliveira; Moura, Candido Augusto Veloso; Scheller, Thomas

    Abstract in English:

    Analytical procedures used for determining the concentrations and isotope composition of strontium in subsurface waters, by mass spectrometry, are described. Sampling was performed in coastal plateaus, salt marsh and mangrove environments in the coastal region of Pará. Coastal plateau waters have delta87Sr between 1.51 and 6.26‰ and Sr concentration bellow 58 ppb. Salt marsh waters show delta87Sr between 0.55 and 0.90‰ and Sr concentration between 93 and 114 ppm, while mangrove waters have delta87Sr‰ around zero and Sr concentration above 15 ppm. Differences in the 87Sr/86Sr ratio in these subsurface waters are detected, as well as seasonal variations in the coastal pleteau waters.
  • Ácido canárico (3,4-seco derivado do lupano) em própolis do Ceará Artigo

    Albuquerque, Irineu L. de; Alves, Leonardo A.; Lemos, Telma L. G.; Monte, Francisco J. Q.; Braz-Filho, Raimundo

    Abstract in English:

    Phytochemical investigation of a propolis sample from Alto Santo - Ceará, Brazil, allowed identification of triterpenes (lupeol, lupenone, germanicone, canaric acid) and flavonoids (quercetin, kaempferol and acacetin), which were identified by spectroscopic data (IR, MS, and NMR, including 2D techniques). This is the first report of canaric acid in propolis. Propolis extract and flavonoids showed antioxidant activity using a DPPH radical scavenging assay.
  • Influência da adição de plastificante do processo de reticulação na morfologia, absorção de aguá e propriedades mecânicas de filmes de alginato de sódio Artigo

    Lima, Aline Margarete Furuyama; Andreani, Larissa; Soldi, Valdir; Borsali, Redouane

    Abstract in English:

    The effects of sorbitol and formaldehyde on the morphology, water absorption and mechanical properties of sodium alginate films were analyzed. The morphology of the films indicated the presence of small aggregates in the surface of uncrosslinked films, which disappeared with the crosslinking process. The water uptake and percentage of elongation increased with the addition of sorbitol in uncrosslinked films. At the same time, a decrease in tensile strength and Young's modulus occurred. The swelling ratio and water uptake of crosslinked alginate/sorbitol films decreased with an increase in sorbitol content suggesting an enhanced crosslinking density due to the presence of plasticizer.
  • Atividade acaricida dos óleos essencias de folhas e frutos de Xylopia sericea sobre o ácaro rajado (Tetranychus urticae Koch) Artigo

    Pontes, Wendel José Teles; Oliveira, José Cândido Selva de; Câmara, Cláudio Augusto Gomes da; Gondim Júnior, Manoel Guedes Correia; Oliveira, José Vargas de; Schwartz, Manfred Oswald Erwin

    Abstract in English:

    The essential oils of the leaves and fruits obtained by hydrodistillation of Xylopia sericea, collected in the restinga area of Pernambuco, were analyzed by GC (HP 5890 SERIES II) and GC/MS (HP 5890B SERIES II/ MSD 5971). A major part of the volatile components identified in the oils of fruits and leaves were monoterpenes and sesquiterpenes. Cubenol (57.43%) and alpha-epi-muurolol (26.09%) were the main compounds found in the leaves, whereas beta-pinene (45.59%) and alpha-pinene (17.18%) were the fruits major components. The acaricidal activity of the essential oils was evaluated for Tetranychus urticae. The oil of the leaves was more active than that of the fruits showing an LC50 value of 4.08 µL/L of air for a 72 h period.
  • Estudo fitoquímico do decocto das folhas de Maytenus truncata Reissek e avaliação das atividades antinociceptiva, antiedematogênica e antiulcerogênica de extratos do decocto Artigo

    Fonseca, Ana Paula Nascentes de Deus; Silva, Grácia Divina de Fátima; Carvalho, Juliana de Jesus; Salazar, Gloria Del Carmen Meléndez; Duarte, Lucienir Pains; Silva, Renata Pamplona; Jorge, Rodrigo Martinez; Tagliati, Carlos Alberto; Zani, Carlos Leomar; Alves, Tânia Maria de Almeida; Peres, Valdir; Vieira Filho, Sidney Augusto

    Abstract in English:

    The present paper describes the phytochemical investigation and biological activities of the chloroform, ethyl acetate and methanol extracts of leaf decocts of M. truncata Reiss (Celastraceae). Our studies afforded two flavonoid glycosides, quercetin-3-O-rhamnopyranosyl-O-glucopyranosyl- O-rhamnopyranosyl-O-galactopyranoside (1) and kampferol-3-O-rhamnopyranosyl-O-glucopyranosyl- O-rhamnopyranosyl-O-galactopyranoside (2) from the methanolic extract and dulcitol (3) from the ethyl acetate extract. Ethyl acetate and methanol extracts exhibited considerable antiulcerogenic and analgesic activities. The results of the phytochemical studies suggest that the healing activity of methanol extracts can be related to the presence of glycosyl flavonoids.
  • Contenido de flavonoides y compuestos fenólicos de mieles chilenas e índice antioxidante

    Muñoz, Orlando; Copaja, Silvia; Speisky, Hernan; Peña, Raúl C.; Montenegro, Gloria

    Abstract in English:

    A comparison of the phenolic content of several Chilean honeys showed great variations in flavonoid concentration among the samples analysed. Higher amounts of phenolics are found in honey from dry climates. The antioxidant effect of extracts, using ORAC analysis, did not correlate with the flavonoid content or with the total phenolic concentration.
  • LS-SVM: uma nova ferramenta quimiométrica para regressão multivariada. Comparação de modelos de regressão LS-SVM e PLS na quantificação de adulterantes em leite em pó empregando NIR Artigo

    Ferrão, Marco F.; Mello, Cesar; Borin, Alessandra; Maretto, Danilo A.; Poppi, Ronei J.

    Abstract in English:

    Least-squares support vector machines (LS-SVM) were used as an alternative multivariate calibration method for the simultaneous quantification of some common adulterants found in powdered milk samples, using near-infrared spectroscopy. Excellent models were built using LS-SVM for determining R², RMSECV and RMSEP values. LS-SVMs show superior performance for quantifying starch, whey and sucrose in powdered milk samples in relation to PLSR. This study shows that it is possible to determine precisely the amount of one and two common adulterants simultaneously in powdered milk samples using LS-SVM and NIR spectra.
  • Correlation of anti-inflammatory activity with phenolic content in the leaves of syzygium cumini (l.) skeels (myrtaceae)

    Lima, Lucilene Azevedo; Siani, Antonio Carlos; Brito, Fabíola Almeida; Sampaio, André Luís Franco; Henriques, Maria das Graças Müller Oliveira; Riehl, Carlos Alberto da Silva

    Abstract in English:

    Phenolic contents of extracts of Syzygium cumini leaves, collected monthly over a one-year period, were quantitatively determined by the modified Folin-Ciocalteau method. Extracts and tannin-free fractions were assayed by their potential to inhibit mouse paw edema induced by C48/80. HPLC showed high molecular weight phenolic species and flavonoids in the active extracts and fractions. The highest total phenolic content corresponded to the most potent degree of inhibition and the flavonoids were supposed to be the main species responsible for the activity, given that the flavonoid-enriched ethyl-acetate fraction maintained its effect down to a dose of 0.01 mg/kg in a dose-response manner.
  • Identificação da influência do descarte de lodo de estações de tratamento de água Artigo

    Reis, Edson Luís Tocaia dos; Cotrim, Marycel Elena Barbosa; Rodrigues, Cláudio; Pires, Maria Aparecida Faustino; Beltrame Filho, Osvaldo; Rocha, Solange Martone; Cutolo, Silvana Audrá

    Abstract in English:

    The growing concern of environmental surveillance of the quality of hydric resources guides the development of research on management of residues generated in water treatment plants (WTP). Approximately 8.000 WTPs in Brazil operate without a treatment program of the residues, disposing these effluents in the environment. This work evaluated WTP discharges into watercourses by collecting superficial waters, sediments and benthic samples at the town of Registro, São Paulo State, Brazil. Even though superficial waters and benthic samples showed no further contamination, sediment analysis pointed out that aluminum deposits detected near sludge discharges may represent a potential risk to the environment.
  • Caracterização dos produtos líquidos e do carvão da pirólise de serragem de eucalipto Artigo

    Martins, Ayrton F.; Diniz, Juraci; Stahl, João A.; Cardoso, André de L.

    Abstract in English:

    This study proposes the low temperature pyrolysis as an alternative conversion process for residual biomass and for obtaining gaseous, liquid and solid chemical feedstocks. Using a bench electrical pyrolysis oven, four product fractions from eucalyptus sawdust were obtained: a gaseous one, two liquid (aqueous and oily), and a solid residue (char). These products were characterized by different analytical methods. The liquid fractions showed themselves as potential sources for input chemicals. The residual char revealed appreciable adsorption capability. The process demonstrated good efficiency, generating at least two fractions of great industrial interest: bio oil and char.
  • Desenvolvimento de um método empregando quitosana para remoção de íons metálicos de águas residuárias Artigo

    Janegitz, Bruno Campos; Lourenção, Bruna Cláudia; Lupetti, Karina Omuro; Fatibello-Filho, Orlando

    Abstract in English:

    In this work a method was developed for removing metallic ions from wastewaters by co-precipitation of Cu2+, Pb2+, Cd2+, Cr3+ and Hg2+ with chitosan and sodium hydroxide solution. Solutions of these metallic ions in the range from 0.55 to 2160 mg L-1 were added to chitosan dissolved in 0.05 mol L-1 HCl. For the co-precipitation of metal-chitosan-hydroxide a 0.17 mol L-1 NaOH solution was added until pH 8.5-9.5. A parallel study was carried out applying a 0.17 mol L-1 NaOH solution to precipitate those metallic ions. Also, a chitosan solid phase column was used for removing those metallic ions from wastewaters.
  • Metales pesados y toxicidad de aguas del Río Aconcagua en Chile

    Gaete, Hernán; Aránguiz, Fernanda; Cienfuegos, Gabriela; Tejos, Marisol

    Abstract in English:

    The toxicity of surface waters in a zone with mining activity in the Aconcagua River was determined through growth inhibition bioassays of Pseudokirchneriella subcapitata, and correlated with heavy metal concentrations. Results show that the waters near the discharge of the mining effluent displayed toxicity during all periods of study; the molybdenum and copper concentration exceeded the norms of water quality. The correlations between the concentrations of metals and the growth rate of P. subcapitata varied in the different periods of the study; inverse and significant correlations with copper stand out in some periods.
  • Estudo da influência dos íons K+, Mg2+, SO4(2-) e CO3(2-) na cristalização biomimética de fosfato de cálcio amorfo (ACP) e conversão a fosfato octacálcico (OCP) Artigo

    Aparecida, Anahí Herrera; Fook, Marcus Vinícius Lia; Santos, Márcio Luis dos; Guastaldi, Antonio Carlos

    Abstract in English:

    The crystallization of hydroxyapatite (HA) in aqueous solution can be described by the mechanism ACP -> OCP -> HA. In this work, it was studied the influence of K+, Mg2+, SO4(2-) and CO3(2-) ions in the formation of ACP and in its conversion to OCP, using biomimetic coatings on metallic substrates of commercially pure titanium (Ti c.p.). The results showed that Mg2+ and CO3(2-) ions favored both the formation of ACP and its conversion to OCP. Differently, K+ and SO4(2-) ions did not influence the formation of ACP and, consequently, interfered in the conversion to OCP.
  • A reatividade do estado excitado triplete de 1,3-indanodiona em benzeno Artigo

    Santos, Frances R. dos; Silva, Mônica T. da; Netto-Ferreira, José Carlos; Lucas, Nanci C. de

    Abstract in English:

    Rate constants for the quenching of 1,3-indandione (1) triplet by olefins and by hydrogen and electron donors were obtained employing the laser flash photolysis technique in benzene solution. These rate constants ranged from 2.5x10(5) Lmol-1s-1 (for 2-propanol) to 5.9x10(9) Lmol-1s-1 (for DABCO). From the quenching rate constants by 1,3-cyclohexadiene, trans- and cis-stilbene a value between 49.3 and 52.4 kcal/mol was estimated for the energy of the triplet state of 1,3-indandione. The npi* character of this triplet state was evidenced by the quenching rate constants obtained when typical hydrogen donors were employed as quenchers. For 2-phenyl-1,3-indandione (2, R=phenyl) a fast Norrish type I reaction is operating which prevents the determination of kinetic and spectroscopic data of its triplet state.
  • Chemical constituents from Bakeridesia pickelii Monteiro (Malvaceae) and the relaxant activity of kaempferol-3-O-beta-D-(6"-E-p -coumaroyl) glucopyranoside on guinea-pig ileum

    Costa, Danielly Albuquerque da; Silva, Davi Antas e; Cavalcanti, Aline Coutinho; Medeiros, Marcos Antônio Alves de; Lima, Julianeli Tolentino de; Cavalcante, José Marcílio Sobral; Silva, Bagnólia Araújo da; Agra, Maria de Fátima; Souza, Maria de Fátima Vanderlei de

    Abstract in English:

    The phytochemical investigation of Bakeridesia pickelii Monteiro led to the isolation of seven compounds: beta-sitosterol, a mixture of sitosteryl-3-O-beta-D-glucopyranoside and stigmasteryl-3-O-beta-D-glucopyranoside, vanillic acid, p-coumaric acid, quercetin 3-O-beta-D-glucopyranoside (isoquercitrin) and kaempferol-3-O-beta-D-(6"-E-p -coumaroyl) glucopyranoside (tiliroside), which was isolated as the major component. Their structures were elucidated on the basis of spectroscopic data such as IR, ¹H and 13C NMR, including two-dimensional techniques. Tiliroside relaxed the guinea-pig ileum pre-contracted with KCl 40 mM (EC50 = 9.5 ± 1.0 x 10-5 M), acetylcholine 10-6 M (EC50 = 2.3 ± 0.9 x 10-5 M) or histamine 10-6 M (EC50 = 4.1 ± 1.0 x 10-5 M) in a concentration-dependent manner.
  • Electrical and magnetic properties of new compounds of the conductor anion [Ni(dmit)2]- and nitronyl nitroxide magnetic radicals

    Dias, Mauro Cesar; Stumpf, Humberto Osório; Sansiviero, Maria Terezinha Caruso; Pernaut, Jean Michel; Matencio, Tulio; Knobel, Marcelo; Cangussu, Danielle

    Abstract in English:

    Three compounds have been synthesized with formulae [3-MeRad][Ni(dmit)2] (1), [4-MeRad][Ni(dmit)2] (2) and [4-PrRad][Ni(dmit)2] (3) where [Ni(dmit)2]- is an anionic pi-radical (dmit = 1,3-dithiol-2-thione-4,5-dithiolate) and [3-MeRad]+ is 3-N-methylpyridinium alpha-nitronyl nitroxide, [4-MeRad]+ is 4-N-methylpyridinium alpha-nitronyl nitroxide and [4-PrRad]+ is 4-N-propylpyridinium alpha-nitronyl nitroxide. The temperature-dependent magnetic susceptibility of 1 revealed that an antiferromagnetic interaction operates between the 3-MeRad+ radical cations with exchange coupling constants of J1 = - 1.72 cm-1 and antiferromagnetism assigned to the spin ladder chains of the Ni(dmit)2 radical anions. Compound 1 exhibits semiconducting behavior and 3 presents capacitor behavior in the temperature range studied (4 - 300 K).
  • Estudo sobre a adsorção do fluido de perfuração salgado contendo polímeros sobre SiO2 Artigo

    Queiroz Neto, João C.; Biscaia Jr, Evaristo Chalbaud; Petri, Denise F. S.

    Abstract in English:

    Polysaccharide-based drilling fluids have been often applied in horizontal wells of petroleum reservoirs in Campos, Rio de Janeiro. The present study aimed to understand the mechanism of adsorption and desorption of the drill-in fluid, xanthan, modified starch and lubricant on SiO2 by means of ellipsometry. The effect of pH and brine on the mean thickness (D) of adsorbed layer was systematically investigated. The adsorption was mainly favored under alkaline conditions. A model has been proposed to explain this effect. The adsorption isotherms determined separately for xanthan and starch on SiO2 surfaces could be fitted with the Langmuir model, which yielded similar adsorption constant values.
  • Identification of acetates in elasmopalpulus lignosellus pheromone glands using a newly created mass spectral database and kóvats retention indices

    Jham, Gulab N.; Silva, Alexsandro A. da; Lima, Eraldo R.; Viana, Paulo A.

    Abstract in English:

    Based on a specially created mass spectral database utilizing 23 tetradecenyl and 22 hexadecenyl acetate standards along with Kóvats retention indices obtained on a very polar stationary phase [poly (biscyanopropyl siloxane)] (SP 2340), (Z)-9-hexadecenyl acetate, (Z)-11-hexadecenyl acetate and (E)-8-hexadecenyl acetate were identified in active pheromone extracts of Elasmopalpus lignosellus. This identification was more efficient than our previous study using gas chromatography/mass spectrometry with a dimethyl disulfide derivative where we could only identify the first two acetates. The acetate composition of the pheromone gland differed from region to region in Brazil and from that from the Tifton (GA, USA) population, suggesting polymorphism or a different sub-species.
  • Determination of chemical elements in africanized Apis mellifera (Hymenoptera: Apidae) honey samples from the State of Piauí, Brazil

    Sodré, Geni da Silva; Marchini, Luís Carlos; Zucchi, Orgeda Luiza Araújo Domingues; Nascimento Filho, Virgilio Franco; Otsuk, Ivani Pozar; Moreti, Augusta Carolina de Camargo Carmello

    Abstract in English:

    Honey is a food used since the most remote times, appreciated for its characteristic flavor, considerable nutritional value and medicinal properties; however, little information exists about the presence of chemical elements in it. The objectives of this work were to determine the chemical elements present in 38 honey samples, collected directly from beekeepers from the State of Piauí, Brazil and to verify whether they presented any contamination. The chemical elements were determined by means of Total Reflection X-ray Fluorescence. The means of three replicates were: K (109.671 ± 17.487), Ca (14.471 ± 3.8797), Ti (0.112 ± 0.07), Cr (0.196 ± 0.11), Mn (0.493 ± 0.103), Fe (1.722 ± 0.446), Co (0.038), Ni (0.728 ± 0.706), Cu (0.179 ± 0.0471), Zn (0.967 ± 0.653), Se (not detected), Br (not detected), Rb (0.371 ± 0.097), Sr (0.145 ± 0.45), Ba (11.681), Hg (not detected), and Pb (0.863) µg g-1.
  • Síntese e propriedades catalíticas em reações de oxidação de goethitas contendo nióbio Artigo

    Oliveira, Luiz C. A.; Gonçalves, Maraísa; Oliveira, Diana Q. L.; Guarieiro, Aline L. N.; Pereira, Márcio C.

    Abstract in English:

    Nb-substituted goethites have been prepared and characterized by Mössbauer spectroscopy, XRD, SEM and BET surface area measurements. Mössbauer and XRD analyses suggested that Nb replaces Fe3+ in the structure with duplet formation. The insertion of Nb into the goethite structure caused a significant increase in the BET surface area of the material. The prepared alpha-Fe1-xNb xOOH was investigated for the H2O2 decomposition to O2 and for the Fenton reaction to oxidize the dye methylene blue. It was observed that the introduction of Nb in to goethite produced a strong increase in the activity of oxidation of the dye contaminant by H2O2.
  • Adsorção de oligonucleotídeos em nanoemulsões obtidas por emulsificação espontânea Artigo

    Martini, Érico; Carvalho, Edison; Teixeira, Helder; Leão, Fabiana; Oliveira, Mônica Cristina de

    Abstract in English:

    This paper describes the adsorption of an oligothymidylate (pdT16) on nanoemulsions obtained by spontaneous emulsification procedures. Formulations were composed by medium chain triglycerides, egg lecithin, glycerol, water (NE) and stearylamine (NE SA). After optimization of operating conditions, the mean droplet size was smaller than 255 nm. Adsorption isotherms showed a higher amount of pdT16 adsorbed on cationic NE SA (60 mg/g) compared to NE (20 mg/g). pdT16 adsorption was also evidenced by the inversion of the zeta-potential of NE SA (from +50 to -30 mV) and the morphology of oil droplets examined through transmission electron microscopy. The overall results showed the role of electrostatic interactions on the adsorption of pdT16 on the oil/water interface of nanoemulsions.
  • Ocorrência e atividade biológica de quassinóides da última década Revisão

    Almeida, Maria Mozarina Beserra; Arriaga, Ângela Martha Campos; Santos, Allana Kellen Lima dos; Lemos, Telma L. G.; Braz-Filho, Raimundo; Vieira, Ivo J. Curcino

    Abstract in English:

    Quassinoids, the bitter principles of the Simaroubaceae family, are a group of structurally complex and highly oxygenated degraded triterpenes. They are divided into five groups according to their basic skeleton, C-18, C-19, C-20, C-22 and C-25. In recent years, attention has been focused on quassinoids because several of them have shown promising biological activities. This paper features a review of some characteristics of these compounds, updating known information with discoveries from the last decade and covering chemical structures, basic skeletons, occurrence in genus and species, besides detailed studies of biological activities such as antitumor, antimalarial, phytotoxic, antifeedant, insecticidal, anti-inflammatory and antiulcer.
  • Análise térmica aplicada ao estudo de materiais energéticos Revisão

    Andrade, Jony; Iha, Koshun; Rocco, Jose Atílio Fritz Fidel; Bezerra, Eduardo Marcelo; Suárez-Iha, Maria Encarnación Vázquez; Pinheiro, Glaci Ferreira Martins

    Abstract in English:

    This paper shows different aspects related to the application of different thermal analysis techniques in the study of energetic materials. The criteria used to choose the best technique and an exact approach to adjust the experimental data with a proper model are here discussed. The paper shows how to use the different thermal analysis results to help develop new compounds, to study the stability of some energetic materials and their compatibility, and the conditions necessary for a secure storing environment.
  • Preparações e aplicações sintéticas recentes de enaminonas Revisão

    Ferraz, Helena M. C.; Gonçalo, Erika R. S.

    Abstract in English:

    Enaminones are beta-enamino carbonylic compounds bearing the conjugated system N-C=C-C=O, which makes them versatile ambident synthetic building blocks, particularly in synthesis of heterocycles. This review covers the last three years of the literature concerning the preparation and synthetic applications of enaminones.
  • Reator de membrana enzimático e fluidos supercríticos: associação de processos Revisão

    Moura, Juliana Maria Leite Nóbrega de; Ribeiro, Ana Paula Badan; Grimaldi, Renato; Gonçalves, Lireny Aparecida Guaraldo

    Abstract in English:

    The aim of this work is to present the new applications of membrane technology in fat and oil processing, with emphasis on development and applications of the enzymatic membrane reactor and its association with extraction and purification technology by supercritical fluids (SCF). Combining the extraction by SCFs and the separation by membranes allows the integration of extractions reactions with selective separation by membranes through filtration of the supercritical mixture (SCF + extracted solutes). This association provides important energy savings regarding the SCF recompression costs.
  • Alcalóides indólicos isolados de espécies do gênero Aspidosperma (Apocynaceae) Revisão

    Pereira, Maria de M.; Jácome, Rose Lisieux R. P.; Alcântara, Antônio Flávio de C.; Alves, Rosemeire B.; Raslan, Délio S.

    Abstract in English:

    Species from genus Aspidosperma (Apocynaceae) are popularly employed to treat various diseases. This genus is characterized by the occurrence of indole alkaloids. Taking into account the various biological activities attributed to these alkaloids, the description of the chemical diversity in genus Aspidosperma is important. A review of simple carbolinic alkaloids isolated from species of various genera was published in 1979. In 1987, it was published another one dealing with the relationships between the chemical structures of the indole alkaloids and the evolution of Aspidosperma species. This work updates the information about the indole alkaloids isolated from Aspidosperma species.
  • Flavonoidic biodiversiy and pharmacologic aspects in the species of the Ouratea and Luxemburgia genera (Ochnaceae) Revisão

    Suzart, Luciano R.; Daniel, Juliana F. de S.; Carvalho, Mário G. de; Kaplan, Maria Auxiliadora Coelho

    Abstract in English:

    This work describes the flavonoids and biflavonoids found in species of Ouratea and Luxemburgia as chemical markers that serve to detect the difference between these taxa according to the linkage between the flavonoidal units. A rational nomenclature is proposed and the pharmacological potencial is discussed.
  • Inativação fotodinâmica de microrganismos Divulgação

    Perussi, Janice Rodrigues

    Abstract in English:

    Photodynamic Therapy uses photosensitive dyes and visible light that, combined in the presence of oxygen, produce cytotoxic species that cause tumor death. Microorganisms such as bacteria, fungi, yeasts and viruses (including HIV) can also be inactivated by visible light after treatment with an appropriate photosensitizer as an alternative low cost treatment for localized infections, viral lesions such as acnes, and fungical skin lesions for example. Besides, Photodynamic Inactivation can be used for sterilization of blood and its subproducts for clinical use, in the treatment of drinking water as well as in antimicrobial detoxification of foods.
  • Recuperação de cobalto e de lítio de baterias íon-lítio usadas Nota técnica

    Busnardo, Natália Giovanini; Paulino, Jéssica Frontino; Afonso, Julio Carlos

    Abstract in English:

    The "active mass" (cathode + anode + electrolyte) of spent Li-ion batteries was submitted to one of the following procedures: (a) it was calcined (500 ºC) and submitted to extraction with water to recover lithium salts. The residual solid was treated with sulfuric acid containing hydrogen peroxide. Cobalt was recovered as sulfate; (b) the "active mass" was treated with potassium hydrogen sulfate (500 ºC) and dissolved in water. Cobalt was precipitated together with copper after addition of sodium hydroxide. Lithium was partially recovered as lithium fluoride. Co-processing of other battery components (aluminum and copper foils) affected negatively the behavior of the recovery procedures. Previous segregation of battery components is essential for an efficient and economical processing of the "active mass".
  • Validação de metodologia analítica por cromatografia líquida para doseamento e estudo da estabilidade de pantoprazol sódico Nota técnica

    Raffin, Renata Platcheck; Colomé, Letícia Marques; Guterres, Sílvia Stanisçuaski; Pohlmann, Adriana Raffin

    Abstract in English:

    Pantoprazole is a proton pump inhibitor used in the treatment of digestive ulcers, gastro-esophageal reflux disease and in the eradication of Helicobacter pylori. In this work, an analytical method was developed and validated for the quantification of sodium pantoprazole by HPLC. The method was specific, linear, precise and exact. In order to verify the stability of pantoprazole during dissolution assays, pantoprazole solution in phosphate buffer pH 7.4 was kept at room temperature and protected from light for 22 days. Pantoprazole presented less than 5% of degradation in 6 hours and the half live of the degradation was 124 h.
  • Determinação do teor de edta remanescente em soluções de limpeza de equipamentos industriais Nota técnica

    Rodella, Arnaldo Antonio

    Abstract in English:

    Cleaning solutions containing EDTA are widely employed to remove incrustation despite of the costs involved. The free content of EDTA in commercial solutions may be determined by mixing an aliquot to ammonium oxalate and using a standard calcium solution as titrant. The end-point is detected by the formation of insoluble calcium oxalate after all EDTA is complexed. A system for turbidimetric detection of the end-point was envisaged to substitute the visual detection, which impaired the analyses of dark samples. The proposed method was tested with real samples and good accuracy and precision was obtained.
  • Teores de carbamato de etila e outros componentes secundários em diferentes cachaças produzidas em três regiões do estado de Minas Gerais: Zona da mata, sul de minas e vale do jequitinhonha Nota técnica

    Barcelos, Luciene Viana Ferreira; Cardoso, Maria das Graças; Vilela, Fernando José; Anjos, Jeancarlo Pereira dos

    Abstract in English:

    Minas Gerais is the highest producer of handmade spirits. Research has been carried out aiming to contribute to progress. Thus, the goal of this work is to evaluate the quality of spirits in three different regions of Minas Gerais state. We analyzed ethyl carbamate, alcoholic grade, volatile acidity, higher alcohols, aldehyde, esters, methanol, furfural and copper. The values obtained for ethyl carbamate varied from undetectable to 643.5 µg L-1, with only one region not following the legislation (150 µg L-1). Most of the compounds in the spirits were present within the limits estabilished by the legislation.
  • A technique for high recoveries from vacuum distillations

    Langler, Richard F.

    Abstract in English:

    The design and use of a novel apparatus for a variant of vacuum distillation is described. Relative to a conventional device, the apparatus/technique described permits superior recovery of multigram quantities of moderately volatile liquids from vacuum distillations.
  • Titulações espectrofotométricas de sistemas ácido-base utilizando extrato de flores contendo antocianinas Educação

    Cortes, Mônica Souza; Ramos, Luiz Antônio; Cavalheiro, Éder Tadeu Gomes

    Abstract in English:

    Considering the attraction of the students' attention by the changes in the colors of vegetable crude extracts caused by the variation of the pH of the medium, the use of these different colors in order to demonstrate principles of spectrophotometric acid-base titrations using the crude extracts as indicators is proposed. The experimental setup consisted of a simple spectrophotometer, a homemade flow cell and a pump to propel the fluids along the system. Students should be stimulated to choose the best wavelength to monitor the changes in color during the titration. Since the pH of the equivalence point depends on the system titrated, the wavelength must be properly chosen to follow these changes, demonstrating the importance of the correct choice of the indicator. When compared with the potentiometric results, errors as low as 2% could be found using Rhododendron simsii (azalea) or Tibouchina granulosa (Glory tree, quaresmeira) as sources of the crude extracts.
  • Pilhas alcalinas: um dispositivo útil para o ensino de Química Educação

    Matsubara, Elaine Y.; Neri, Cláudio R.; Rosolen, J. Maurício

    Abstract in English:

    This paper presents the alkaline battery (MnO2/Zn) as a useful device in the teaching of chemistry. The preparation of the battery, the materials used in the preparation of the MnO2 electrode, the mechanism of energy storage and the parameters often used in the understanding of general batteries are discussed in detail. In addition, a schedule and a questionnaire that can be applied in an experimental class have been developed, which allow the assembly of an alkaline battery, its discharge using a galvanostatic or a load-resistance procedure, and the elaboration of a report based on the main text. This experimental class has been offered in the chemistry course of FFCLRP.
  • Esquema geral para elucidação de substâncias orgânicas usando métodos espectroscópico e espectrométrico Educação

    Ribeiro, Carlos Magno R.; Souza, Nelson Ângelo de

    Abstract in English:

    This work describes a systematic method to be applied in undergraduate courses of organic chemistry, correlating infrared spectra, hydrogen and carbon-13 nuclear magnetic resonance, and mass spectra. To this end, a scheme and a table were developed to conduct the elucidation of the structure of organic compounds initially using infrared spectra. Interpretation of hydrogen and carbon-13 nuclear magnetic resonance spectra and of mass spectra is used to confirm the proposed structure.
  • A rota dos estudos sobre a cochonilha em Portugal e no Brasil no século XIX: caminhos desencontrados Assuntos gerais

    Ferraz, Márcia Helena Mendes

    Abstract in English:

    For imparting an intense and long-lasting red to fabrics, cochineal remained in high demand during the eighteenth and nineteenth centuries. This period witnessed, accordingly, several initiatives aimed at producing the precious dye: publication of specialized texts, cultivation of the cactus and the insect from which the dye is extracted, and, also, attempts to obtain the secrets of production through espionage. The present paper analyses certain aspects of the measures adopted by the Portuguese government towards Brazil in this field. The work shows how people sought to take part in the network of cochineal production (yet they were unsuccessful most of the time).
  • Passando da doutrina à prática: Ezequiel Corrêa dos Santos e a farmácia nacional Assuntos gerais

    Santos, Nadja Paraense dos

    Abstract in English:

    This article presents a sample of the activities of apothecary Ezequiel Corrêa dos Santos. He was notable not only for his professional career, but also for his political militancy, making an important contribution to the development of pharmaceutical sciences in Brazil, in the XIXth century.
  • Vladimir Prelog e a estereoquímica das moléculas orgânicas: um centenário de nascimento Assuntos gerais

    Rezende, Claudia M.

    Abstract in English:

    The Croatian chemist Vladimir Prelog shared in 1975 the Nobel Prize in chemistry with J. W. Cornforth for his research into the stereochemistry of organic molecules and reactions. His studies gave new horizons to the comprehension of steric effects on the reactivity of medium-sized rings, to conformational analysis and to the stereospecificity associated to asymmetric syntheses. Prelog made important contributions to enzyme chemistry and to the structure elucidation of alkaloids and of antibiotics from microorganisms, but probably his most famous work is the CIP system for assigning the stereochemistry of chiral centers.
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