26/7/2012
Saiu o JBCS número 7 - Volume 23
Education: a Duty of All
With 107 years, the Memórias do Instituto Oswaldo Cruz is the oldest Brazilian scientific journal. The two major funding agencies for scientific research: the National Council for Technological and Scientific Development (CNPq) and the Brazilian Federal Agency for Support and Evaluation of Graduate Education (CAPES) were only created in 1951, after the Second World War, and a major one, the São Paulo Research Foundation (FAPESP) has just turned 50.
(Read more at Editorial)
Table of Contents with Graphical Abstracts
Preparation, Characterisation and Evaluation of Brazilian Clay-Based Catalysts for use in Esterification Reactions |
Michelle J. C. Rezende, Mírian S. C. Pereira, Gabriel F. N. Santos, Gabriel O. P. Aroeira,
Tiago C. Albuquerque Jr., Paulo A. Z. Suarez and Angelo C. Pinto |
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Natural Brazilian clays were used as received, without any previous treatment to eliminate organic materials, quartz, other materials or minerals. The clays were from Paraíba and, after an acid treatment, showed good catalytic performance in the esterification of several carboxylic acids with different alcohols. Good yields were achieved in a reaction medium composed only of carboxylic acid, alcohol and catalyst. Co-solvent was not used and the reactions were carried out at atmospheric pressure. |
Details are discussed in the Article Preparation, Characterisation and Evaluation of Brazilian Clay-Based Catalysts for use in Esterification Reactions by Michelle J. C. Rezende, Mírian S. C. Pereira, Gabriel F. N. Santos, Gabriel O. P. Aroeira, Tiago C. Albuquerque Jr., Paulo A. Z. Suarez and Angelo C. Pinto on page 1209. |
>> Editorial(308 KB)
Education: a Duty of All
Angelo C. Pinto |
| J. Braz. Chem. Soc. 2012, 23, 1199. |
Development of a Lewis-Based Catalytic System for Biodiesel Production: from a Batch Laboratory Scale to a Continuous Pilot Plant |
| Paulo A. Z. Suarez and Fabio M. da Silva |
| J. Braz. Chem. Soc. 2012, 23, 1201. |
 Using the development of a biodiesel process, this paper discusses the hard way to transform science in technology. It is described the initial development in a laboratory scale and the long way to achieve a laboratory pilot plant scale |
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Published online: July 11, 2012 |
Preparation, Characterisation and Evaluation of Brazilian Clay-Based Catalysts for use in Esterification Reactions |
Michelle J. C. Rezende, Mírian S. C. Pereira, Gabriel F. N. Santos, Gabriel O. P. Aroeira,
Tiago C. Albuquerque Jr., Paulo A. Z. Suarez and Angelo C. Pinto |
| J. Braz. Chem. Soc. 2012, 23, 1209. cover article |
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| Natural Brazilian clay-based catalysts were prepared, characterized, and their catalytic activity was assessed in esterification reactions. The reactions were performed without a Dean-Stark apparatus or co-solvent, at atmospheric pressure in a short reaction time. The acid-activated clays provided good yields for various carboxylic acids and alcohols |
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Published online: May 8, 2012 |
The Effect of Neutral Oximes on the Reactivation of Human Acetylcholinesterase Inhibited with Paraoxon |
| Tatiana S. Ribeiro, Arthur Prates, Sérgio R. Alves, Jefferson J. Oliveira-Silva, Carlos A. S. Riehl and J. Daniel Figueroa-Villar |
| J. Braz. Chem. Soc. 2012, 23, 1216. |
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| Neutral oximes, with better hematoencephalic barrier permeation than cationic oximes commercially used as chemical warfare defense agents, display capacity to reactivate human acetylcholinesterase inhibited by neurotoxic organophosphorus compounds |
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Published online: June 12, 2012 |
Synthesis and Characterization of Polyesters from Glycerol by-Product of
Biodiesel Production |
Carla V. Rodarte de Moura, Antonia S. L. Nunes, Jose M. Moita Neto, Haroldo L. S. Neres,
Lee M. G. de Carvalho and Edmilson M. de Moura |
| J. Braz. Chem. Soc. 2012, 23, 1226. |
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| Six types of resins derived from glycerol were produced and resulting in oligomers with average molecular weights ranging from 1800-2800 Da and polydispersity indexes (PDI) from 1.3 to 1.8. Resins derived from carboxylic acids are thermally more stable than resins derived from formaldehyde |
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Published online: June 12, 2012 |
Synthesis of Polyols from Mabea fistulifera Mart. (Euphorbiaceae) Oil |
| Julieta J. da Silveira Neta, Carlos J. da Silva, Róbson R. Teixeira, César Reis, Efraim L. Reis and Amanda M. Teixeira |
| J. Braz. Chem. Soc. 2012, 23, 1232. |
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| The plant species Mabea fistulifera Mart. |
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Published online: June 12, 2012 |
New Flavonoids and Coumarins from Platymiscium floribundum Vogel |
Pérsio A. Veloso, Antonia T. A. Pimenta, Francisco M. de Sousa, Maria José C. Falcão,
Nilce V. Gramosa, José Nunes da Silva Junior, Edilberto R. Silveira and Mary Anne S. Lima |
| J. Braz. Chem. Soc. 2012, 23, 1239. |
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| Two new flavonoids, 3,4,10-trihydroxy-9-methoxypterocarpan (1) and 2´,4´-dihydroxy-4-methoxy-β-hydroxychalcanonol (2), were isolated from Platymiscium floribundum in addition to several flavonoids and coumarins |
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Published online: June 12, 2012 |
Pterodon pubescens Benth: Stability Study of Microencapsulated Extract and Isolated Compounds Monitored by Antinociceptive Assays |
| Leila Servat, Humberto M. Spindola, Rodney A. F. Rodrigues, Ilza M. O. Sousa, Ana L. T. G. Ruiz, João E. de Carvalho and Mary A. Foglio |
| J. Braz. Chem. Soc. 2012, 23, 1244. |
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| This study reports the advantages presented by the microencapsulation of products obtained from P. pubescens on the antinociceptive activity provided by the crude extract and isolated furanditerpenes |
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Published online: June 14, 2012 |
Solvent Extraction Studies on Uranium using Amine Based Extractants and Recovery from Low Grade Ore Leach Liquors |
| Chul-Joo Kim, Jyothi Rajesh Kumar, Joon-Soo Kim, Jin-Young Lee and Ho-Sung Yoon |
| J. Braz. Chem. Soc. 2012, 23, 1254. |
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This study is applied to the uranium extraction from Korean domestic low grade ore leach liquors using Alamine 336 as extractant. It has successfully achieved 99.83% uranium recovery with zero interfere |
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Published online: June 14, 2012 |
Guanabara Bay Sedimentation Rates based on 210Pb Dating: Reviewing the Existing Data and Adding New Data |
| Jose M. Godoy, Alessandra V. Oliveira, Ana C. Almeida, Maria Luiza D. P. Godoy, Isabel Moreira, Angela R. Wagener and Alberto G. de Figueiredo Junior |
| J. Braz. Chem. Soc. 2012, 23, 1265. |
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| Sampling points with available 210Pb based sedimentation rates data in the literature and additional data obtained in the present work (BG sampling points) |
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Published online: June 19, 2012 |
8-O-4’-Neolignans from Flower Buds of Magnolia fargesii and their Biological Activities |
| Xuemei Gao, Yanqiong Shen, Liying Yang, Lidang Shu, Ganpeng Li and Qiu-Fen Hu |
| J. Braz. Chem. Soc. 2012, 23, 1274. |
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| Three new 8-O-4'-neolignans, fargesiphenols A-C (1-3), together with six known neolignans, were isolated from the flower buds of Magnolia fargesii. The structures were elucidated by spectroscopic methods, including extensive 1D and 2D-NMR techniques. Compounds were also tested for their anti-HIV-1 activities and cytotoxicities |
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Published online: June 19, 2012 |
Bioaccumulation of Mercury and Selenium in Trichiurus lepturus |
| Tércia G. Seixas, Isabel Moreira, Olaf Malm and Helena A. Kehrig |
J. Braz. Chem. Soc. 2012, 23, 1280. |
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| Muscular mercury and selenium were assessed in cutlassfish from three coastal areas presenting different environmental conditions in Southeastern Brazil. Regional differences were observed in mercury concentrations and Se:Hg molar ratios. A large excess of selenium in relation to mercury was observed. Cutlassfish is suitable for human consumption |
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Published online: June 19, 2012 |
Complexation Behavior in Aqueous Edta Sol-Gel Systems for the
Synthesis of YBa2Cu3O7–x High-Temperature Superconductors |
| Tran Thi Thuy, Gerrit Herman, Petra Lommens and Isabel Van Driessche |
| J. Braz. Chem. Soc. 2012, 23, 1289. |
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| The complexation behavior of aqueous precursor formulations with a minimal amount of organic compounds was studied for the preparation of YBa2Cu3O7-x superconducting perovskites. The products were obtained from inexpensive and easily available chemicals and displayed good long-term stability together with excellent application properties |
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Published online: June 19, 2012 |
Preparation and Electrochemical Properties of Homogeneous Carbon-Coated
LiFe0.9Mn0.1PO4 as Cathode Material for Lithium-Ion Batteries |
| Yang Xu, Jingang Yu, Sui Peng, Suqin Liu, Zhongqiang Wei, Xianhong Li and Yajuan Li |
| J. Braz. Chem. Soc. 2012, 23, 1298. |
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| LiFePO4 was synthesized with both carbon-coating and Mn-doping by a simple solid-state reaction. The as-prepared particles presented a size range of 100-200 nm and uniform carbon webs. The LiFe0,9Mn0,1PO4/C composite delivered initial discharge capacities of 154.1 and 94 mA h g-1 at current rates of 0.1 and 10.0 C (C = 170 mA g-1), respectively |
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Published online: June 21, 2012 |
Unsynchronized Resonance of Covalent Bonds in the Superconducting State |
| Marconi B. S. Costa, Cristiano C. Bastos and Antonio C. Pavão |
| J. Braz. Chem. Soc. 2012, 23, 1305. |
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| Cluster models employed in the atomic charge distribution and HOMO-LUMO energy gap analysis. This work presents evidence for the unsynchronized resonance of covalent bonds in the superconducting state, according to predictions of the RVB theory developed by L. Pauling |
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Published online: June 21, 2012 |
Simultaneous Spectrophotometric Determination of Cu(II), Co(II) and Ni(II)
using Ratio Spectra-Continuous Wavelet Transformation in some Food and
Environmental Samples |
| Maryam Abbasi Tarighat and Abbas Afkhami |
| J. Braz. Chem. Soc. 2012, 23, 1312. |
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| Ratio spectra-CWT for determination of ions, based on complexation with PAN, was introduced and advantage of CWT for simultaneous determination of ions was examined. The method was validated by determination of ions in tea, barley, spinach, chocolate and milk powder samples |
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Published online: June 21, 2012 |
On Site Stripping Voltammetric Determination of Zn(II), Cd(II) and Pb(II) in Water Samples of the Cananéia-Iguape Estuarine-Lagoon Complex in São Paulo State, Brazil |
| Ana P. R. de Souza, Elisabete S. Braga and Mauro Bertotti |
| J. Braz. Chem. Soc. 2012, 23, 1320. |
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| Monitoring of heavy metal concentrations by stripping voltammetry with bismuth film microelectrode in the Cananéia-Iguape Estuarine-Lagoon region (São Paulo State, Brazil) |
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Published online: June 21, 2012 |
Determination of Pyrethroid Pesticides in Environmental Samples using
Ionic Liquid Dispersive Liquid-Liquid Microextraction |
| Tong Wu, Yu Liu, Zhonghua Yang, Haixiang Gao and Zhiqiang Zhou |
| J. Braz. Chem. Soc. 2012, 23, 1327. |
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Target analytes were extracted into ionic liquid from aqueous phase. Extraction, concentration and purification were done in one-step. After centrifugation, ionic liquid phase was sedimented at the bottom of the tube |
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Published online: June 26, 2012 |
Simulation of the Interactions between Tröger Bases and DNA |
| Clarisse G. Ricci and Paulo A. Netz |
| J. Braz. Chem. Soc. 2012, 23, 1334. |
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| Molecular dynamics simulations of the complex involving short DNA fragments and proflavin and phenanthroline substituted Tröger bases point out to a mixed binding mode, with one substituent intercalated and minor groove binding for the other |
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Published online: June 26, 2012 |
Discrimination of Commercial Roasted and Ground Coffees According to
Chemical Composition |
| Romilaine M. N. de Souza and Marta T. Benassi |
| J. Braz. Chem. Soc. 2012, 23, 1347. |
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| Roasted and ground 38 commercial coffees were studied for assessing the addition of robusta coffee in commercial products which are blends of two coffee species (arabica and robusta). Thermostable parameters (caffeine, kahweol, cafestol) had high discriminative potential between the species. The use of the parameters kahweol/cafestol and caffeine/kahweol ratios was suggested |
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Published online: June 28, 2012 |
Mesophase Evolution in Heat-Treated Solid Petroleum Pitches |
| Antonio L. dos Santos Lima, Keila dos Santos C. Lima, Tanos C. C. França, Maria Inês B. Tavares, Rosane A. da Silva San-Gil, Marcos N. Eberlin and Angelo C. Pinto |
| J. Braz. Chem. Soc. 2012, 23, 1355. |
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| Micrographs of polarized light of the pitches submitted to the thermic treatment and other techniques for evaluation of the mesophase evolution |
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Published online: June 28, 2012 |
Mechanistic Implications of Zinc(II) Ions on the Degradation of Phenol by the Fenton Reaction |
| Leidi Cecilia Friedrich, Maria Anita Mendes, Volnir Oliveira Silva, Carmem Lúcia P. S. Zanta, Amilcar Machulek Jr. and Frank Herbert Quina |
| J. Braz. Chem. Soc. 2012, 23, 1372. |
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| The experimental results show that there is an increase in the removal rate of organic carbon depending on the concentration of Zn2+. Due to the increased persistence of the semiquinone radical of catechol in aqueous solution, Fe2+ is regenerated for a longer time and more HO. radicals are generated |
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Published online: June 28, 2012 |
Yield of Aromatics from Naphthenics upon Catalytic Cracking |
| Richard A. Pujro, Marisa G. Falco, Anne M. Garrido Pedrosa, Marcelo J. B. Souza, Edisson Morgado Jr. and Ulises Sedran |
| J. Braz. Chem. Soc. 2012, 23, 1378. |
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| Decalin was used as a test reactant to study the formation of aromatics in liquid products of the FCC process. Isomerization, ring opening and direct hydrogen transfer were the most important reactions at very short contact times. Diffusion restrictions did not prevail in FCC catalysts with different accessibilities. A mechanism was proposed for the formation of aromatic hydrocarbons |
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Published online: June 29, 2012 |
Chemometric Tools in Chemical Fractionation Data of Soil Samples from
Five Antarctic Research Stations |
| Marcelo B. B. Guerra, Paula F. Rosa, Carlos E. G. R. Schaefer, Roberto F. M. Michel, Ivan C. Almeida and Edenir R. Pereira-Filho |
| J. Braz. Chem. Soc. 2012, 23, 1388. |
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| Soil samples at the vicinity of Antarctic scientific stations are clearly impacted by Cu and Zn deposition, related to diesel-generator burning |
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Published online: June 29, 2012 |
Lipase-Catalyzed Kinetic Resolution of (±)-Mandelonitrile under Conventional Condition and Microwave Irradiation |
| Sandra S. Ribeiro, Julieta R. de Oliveira and André L. M. Porto |
| J. Braz. Chem. Soc. 2012, 23, 1395. |
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| Chemoenzymatic resolution of (±)-mandelonitrile produced the (S)-mandelonitrile acetate with 92% ee, enantiomeric excess) and 35% yield, and the unreacted (R)-mandelonitrile was partially converted into benzaldehyde by spontaneous chemical equilibrium under microwave irradiation. Conventional transesterification of (±)-mandelonitrile in an orbital shaker produced the unreacted (R)-mandelonitrile (51% ee) and the (S)-mandelonitrile acetate (98% ee) |
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Published online: June 26, 2012 |
Determination of Na, K, Mg and Ca in Biodiesel by LS F AAS and HR-CS F AAS:
Studies that Supported the Proposal of the ABNT NBR 15556 Norm |
| Ligia C. C. de Oliveira, Mariana A. Vieira, Anderson S. Ribeiro, Paula M. Baptista, Rodrigo A. Gonçalves and Reinaldo C. de Campos |
| J. Braz. Chem. Soc. 2012, 23, 1400. |
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| This work presents the experiments taken to the adoption of the ABNT NBR 15556 norm, a Brazilian norm for the determination of Na, K, Ca and Mg in biodiesel |
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Published online: June 26, 2012 |
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