JBCS

21:29, Mon Mar 27

Open Access/APCs

vol. 23, No. 7, 2012, p. 1199-1408

 

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)


Cover Article
J. Braz. Chem. Soc. 2012, 23(7), 1209-1215

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; Angelo C. Pinto

How to cite this article

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.

http://dx.doi.org/10.1590/S0103-50532012000700003

Published online: May 8, 2012

Editorial J. Braz. Chem. Soc. 2012, 23(7), 1199

Education: a duty of all

Angelo C. Pinto

How to cite this article

 

http://dx.doi.org/10.1590/S0103-50532012000700001


Account J. Braz. Chem. Soc. 2012, 23(7), 1201-1208

Development of a lewis-based catalytic system for biodiesel production: from a batch laboratory scale to a continuous pilot plant

Paulo A. Z. Suarez; Fabio M. da Silva

How to cite this article

 

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

http://dx.doi.org/10.1590/S0103-50532012000700002


Articles J. Braz. Chem. Soc. 2012, 23(7), 1209-1215

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; Angelo C. Pinto

How to cite this article

 

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

http://dx.doi.org/10.1590/S0103-50532012000700003

Published online: May 8, 2012


J. Braz. Chem. Soc. 2012, 23(7), 1216-1225

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; J. Daniel Figueroa-Villar

How to cite this article

 

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

http://dx.doi.org/10.1590/S0103-50532012000700004



J. Braz. Chem. Soc. 2012, 23(7), 1226-1231

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; Edmilson M. de Moura

How to cite this article

 

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

http://dx.doi.org/10.1590/S0103-50532012000700005

Published online: June 12, 2012

J. Braz. Chem. Soc. 2012, 23(7), 1232-1238

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; Amanda M. Teixeira

How to cite this article

 

The plant species Mabea fistulifera Mart.

http://dx.doi.org/10.1590/S0103-50532012000700006

Published online: June 12, 2012


J. Braz. Chem. Soc. 2012, 23(7), 1239-1243

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; Mary Anne S. Lima

How to cite this article

 

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

http://dx.doi.org/10.1590/S0103-50532012000700007



J. Braz. Chem. Soc. 2012, 23(7), 1244-1253

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; Mary A. Foglio

How to cite this article

 

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

http://dx.doi.org/10.1590/S0103-50532012000700008

Published online: June 14, 2012

J. Braz. Chem. Soc. 2012, 23(7), 1254-1264

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; Ho-Sung Yoon

How to cite this article

 

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

http://dx.doi.org/10.1590/S0103-50532012000700009

Published online: June 14, 2012

J. Braz. Chem. Soc. 2012, 23(7), 1265-1273

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; Alberto G. de Figueiredo Junior

How to cite this article

 

Sampling points with available 210Pb based sedimentation rates data in the literature and additional data obtained in the present work (BG sampling points)

http://dx.doi.org/10.1590/S0103-50532012000700010

Published online: June 19, 2012

J. Braz. Chem. Soc. 2012, 23(7), 1274-1279

8-O-4'-Neolignans from flower buds of Magnolia fargesii and their biological activities

Xuemei Gao; Yanqiong Shen; Liying Yang; Lidang Shu; Ganpeng Li; Qiu-Fen Hu

How to cite this article

 

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

http://dx.doi.org/10.1590/S0103-50532012000700011

Published online: June 19, 2012


J. Braz. Chem. Soc. 2012, 23(7), 1280-1288

Bioaccumulation of mercury and selenium in Trichiurus lepturus

Tércia G. Seixas; Isabel Moreira; Olaf Malm; Helena A. Kehrig

How to cite this article

 

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

http://dx.doi.org/10.1590/S0103-50532012000700012

Published online: June 19, 2012


J. Braz. Chem. Soc. 2012, 23(7), 1289-1297

Complexation behavior in aqueous edta sol-gel systems for the synthesis of YBa2Cu3O7-x high-temperature superconductors

Tran Thi Thuy; Gerrit Herman; Petra Lommens; Isabel Van Driessche

How to cite this article

 

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

http://dx.doi.org/10.1590/S0103-50532012000700013


J. Braz. Chem. Soc. 2012, 23(7), 1298-1304

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; Yajuan Li

How to cite this article

 

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

http://dx.doi.org/10.1590/S0103-50532012000700014


J. Braz. Chem. Soc. 2012, 23(7), 1305-1311

Unsynchronized resonance of covalent bonds in the superconducting state

Marconi B. S. Costa; Cristiano C. Bastos; Antonio C. Pavão

How to cite this article

 

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

http://dx.doi.org/10.1590/S0103-50532012000700015


J. Braz. Chem. Soc. 2012, 23(7), 1312-1319

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; Abbas Afkhami

How to cite this article

 

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

http://dx.doi.org/10.1590/S0103-50532012000700016

Published online: June 21, 2012

J. Braz. Chem. Soc. 2012, 23(7), 1320-1326

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; Mauro Bertotti

How to cite this article

 

Monitoring of heavy metal concentrations by stripping voltammetry with bismuth film microelectrode in the Cananéia-Iguape Estuarine-Lagoon region (São Paulo State, Brazil)

http://dx.doi.org/10.1590/S0103-50532012000700017

Published online: June 21, 2012

J. Braz. Chem. Soc. 2012, 23(7), 1327-1333

Determination of pyrethroid pesticides in environmental samples using ionic liquid dispersive liquid-liquid microextraction

Tong Wu; Yu Liu; Zhonghua Yang; Haixiang Gao; Zhiqiang Zhou

How to cite this article

 

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

http://dx.doi.org/10.1590/S0103-50532012000700018


J. Braz. Chem. Soc. 2012, 23(7), 1334-1346

Simulation of the interactions between Töger bases and DNA

Clarisse G. Ricci; Paulo A. Netz

How to cite this article

 

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

http://dx.doi.org/10.1590/S0103-50532012000700019

Published online: June 26, 2012


J. Braz. Chem. Soc. 2012, 23(7), 1347-1354

Discrimination of commercial roasted and ground coffees according to chemical composition

Romilaine M. N. de Souza; Marta T. Benassi

How to cite this article

 

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

http://dx.doi.org/10.1590/S0103-50532012000700020

Published online: June 28, 2012


J. Braz. Chem. Soc. 2012, 23(7), 1355-1371

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; Angelo C. Pinto

How to cite this article

 

Micrographs of polarized light of the pitches submitted to the thermic treatment and other techniques for evaluation of the mesophase evolution

http://dx.doi.org/10.1590/S0103-50532012000700021

Published online: June 28, 2012

J. Braz. Chem. Soc. 2012, 23(7), 1372-1377

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.; Frank Herbert Quina

How to cite this article

 

http://dx.doi.org/10.1590/S0103-50532012000700022


J. Braz. Chem. Soc. 2012, 23(7), 1378-1387

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.; Ulises Sedran

How to cite this article

 

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

http://dx.doi.org/10.1590/S0103-50532012000700023

Published online: June 29, 2012

J. Braz. Chem. Soc. 2012, 23(7), 1388-1394

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; Edenir R. Pereira-Filho

How to cite this article

 

http://dx.doi.org/10.1590/S0103-50532012000700024

Published online: June 29, 2012


J. Braz. Chem. Soc. 2012, 23(7), 1395-1399

Lipase-catalyzed kinetic resolution of (±)-mandelonitrile under conventional condition and microwave irradiation

Sandra S. Ribeiro; Julieta R. de Oliveira; André L. M. Porto

How to cite this article

 

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)

http://dx.doi.org/10.1590/S0103-50532012000700025

Published online: June 26, 2012


J. Braz. Chem. Soc. 2012, 23(7), 1400-1408

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. Gonþalves; Reinaldo C. de Campos

How to cite this article

 

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

http://dx.doi.org/10.1590/S0103-50532012000700026

Published online: June 26, 2012

Online version ISSN 1678-4790 Printed version ISSN 0103-5053
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