JBCS

3:46, Thu Mar 30

Open Access/APCs

vol. 22, No. 11, 2011, p. 2023-2238

 

Algae Biodiesel: a Promise or the Future?

The increasing demand for "green" fuels to replace the fossil fuels has led to the launching of biofuel programs all over the world. By launching first the ethanol program and then the biodiesel one, the Brazilian government came out first in this rush. Nowadays, in Brazil, it is mandatory the addition of ethanol to the gasoline (a 20-to-25% content, depending on the supply of anhydrous ethanol in the market) and the addition of biodiesel to the diesel (a fixed 5% content).

(Read more at Editorial)



Editorial J. Braz. Chem. Soc. 2011, 22(11), 2023-2026

Algae Biodiesel: a Promise or the Future?

Paulo A. Z. Suarez; Angelo C. Pinto

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http://dx.doi.org/10.1590/S0103-50532011001100001


Articles J. Braz. Chem. Soc. 2011, 22(11), 2027-2035

Active Carbon Preparation from Treads of Tire Waste for Dye Removal in Waste Water

Michael R. Nunes; Giordana M. Perez; Lara F. Loguercio; Eliete W. Alves; Neftali L. V. Carreño; Jorge L. Martins; Irene T. S. Garcia

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Graphical abstract shows the part of the tire which is used for recycling (treads), the scanning electron microscopy of the obtained carbons and, in first plane, the efficiency of these carbons in removing dye as function of time

http://dx.doi.org/10.1590/S0103-50532011001100002

Published online: August 23, 2011

J. Braz. Chem. Soc. 2011, 22(11), 2036-2039

Microwave-Assisted Synthesis of Indole-2-Carboxylic Acid Esters in Ionic Liquid

Lijun Gu; Xiangguang Li

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An improved procedure for the synthesis of indole-2-carboxylic acid esters in excellent yields has been achieved using ionic liquid under controlled microwave irradiation (100 W) at 50 °C

http://dx.doi.org/10.1590/S0103-50532011001100003

Published online: August 25, 2011


J. Braz. Chem. Soc. 2011, 22(11), 2040-2047

Dispersing Carbon Nanotubes in Phenolic Resin using an Aqueous Solution

Edson C. Botelho; Elilton R. Edwards; Birgit Bittmann; Thomas Burkhart

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The dispersion of carbon nanotubes in water with different surfactants, as well as its incorporation into phenolic resin, was investigated. Ultrasonication of liquid suspensions was used to prepare stable dispersions and to evaluate the best surfactant to be used. Light scattering and UV-Visible spectroscopy was performed. The image shows a SEM micrograph for fractured surface of 0.5 wt.% CNT/phenolic composite containing 0.5 wt% of PSS surfactant

http://dx.doi.org/10.1590/S0103-50532011001100004

Published online: August 25, 2011

J. Braz. Chem. Soc. 2011, 22(11), 2048-2055

Multiresidue Methods for Determination of Pesticides using SPME and SPE Followed by GC-NPD System: a Comparative Study

Maria A. L. Milhome; Paula L. R. Sousa; Denis De Keukeleire; Ronaldo F. Nascimento

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Extracted amount for the pesticides obtained with two different thicknesses of the polydimethylsiloxane fiber

http://dx.doi.org/10.1590/S0103-50532011001100005

Published online: August 30, 2011

J. Braz. Chem. Soc. 2011, 22(11), 2056-2064

Square-Wave Cathodic Adsorptive Stripping Voltammetric Determination of 3-Hydroxyflavone, Morin and Hesperidin in Bulk Form and Biological Fluids in Absence and Presence of Cu(II)

Yassien M. Temerk; Mohamed S. Ibrahim; Mohammed Kotb

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Validated, simple, fast and sensitive square-wave cathodic adsorptive stripping voltammetric procedure was described for the determination of 3-hydroxyflavone, morin and hesperidin in biological fluids. The LOD and LOQ calculated for the investigated flavonoids confirmed the sensitivity of the proposed procedure

http://dx.doi.org/10.1590/S0103-50532011001100006

Published online: September 1, 2011

J. Braz. Chem. Soc. 2011, 22(11), 2065-2069

Microwave-Assisted Clean Synthesis of Amides via Aza-Wittig Reaction under Solvent-Free Condition

Murugan Sathishkumar; Sangaraiah Nagarajan; Poovan Shanmuga Velan; Murugan Dinesh; Alagusundaram Ponnuswamy

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Solvent-free microwave-assisted amide synthesis via coupling of nascent phosphazenes with acyl chlorides or carboxylic anhydrides has been accomplished. It is an eco-friendly, rapid and simple approach eradicating the limitations associated with the prevailing time-consuming solution phase methodologies

http://dx.doi.org/10.1590/S0103-50532011001100007

Published online: September 1, 2011


J. Braz. Chem. Soc. 2011, 22(11), 2070-2077

Comparative Study of the Catalytic Activity of the Complexes Cp*RuCl(PAr3)2 [Ar = -C6H5 and 4-CF3-C6H4] in the ATRP of Styrene

Alejandro M. Villa-Hernández; Claudia P. Rosales-Velázquez; Enrique Saldívar-Guerra; José R. Torres-Lubián

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The SEC curves obtained during styrene polymerization mediated by ATRP catalysts 1 and 2 shows that the control of MW is better with catalyst 1 than 2. This is a consequence of the phosphine ligand properties

http://dx.doi.org/10.1590/S0103-50532011001100008

Published online: September 1, 2011


J. Braz. Chem. Soc. 2011, 22(11), 2078-2086

Theoretical Substituent Electrophilicities

Marcos Caroli Rezende; Daniela Millán

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Theoretical substituent electrophilicities σw were derived from the global electrophilicity of substituted benzoic acids, with applications to a variety of chemical processes. The good correlation between the theoretical σw and the empirical Hammett's σ  for uncharged substituents is discussed and explained

http://dx.doi.org/10.1590/S0103-50532011001100009

Published online: September 1, 2011

J. Braz. Chem. Soc. 2011, 22(11), 2087-2093

Phenylpropanoid Substituted Flavan-3-ols from Trichilia catigua and their In Vitro Antioxidative Activity

Flávia O. Resende; Edson Rodrigues-Filho; Heinrich Luftmann; Frank Petereit; João C. Palazzo de Mello

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The phenylpropanoid substituted flavan-3-ol apocynin E was isolated along with eight known compounds from the stem bark of Trichilia catigua. All of them exhibited higher radical scavenging activity and reducing power than ascorbic acid and Trolox

http://dx.doi.org/10.1590/S0103-50532011001100010

Published online: September 6, 2011


J. Braz. Chem. Soc. 2011, 22(11), 2094-2100

Metal Speciation in Surface Sediments of the Uberabinha River in Uberlândia, MG State, Brazil

Luciano A. da Silva; Luciana M. Coelho; Vania Rosolen; Nívia M. Melo Coelho

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The figure shows distribution of Cu in fractions obtained through sequential extraction. The sequential extractions allowed the portion of metals associated with the 13 non-residual (FR1: acid extractable, FR2: reducible, FR3: oxidizable) and residual 14 fractions (R) of the sediment to be determined

http://dx.doi.org/10.1590/S0103-50532011001100011

Published online: September 6, 2011


J. Braz. Chem. Soc. 2011, 22(11), 2101-2107

Synthesis and Mechanism of Formation of Oxadeazaflavines by Microwave Thermal Cyclization of ortho-Halobenzylidene Barbiturates

J. Daniel Figueroa-Villar; Sandra C. G. de Oliveira

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Oxadeazaflavines are prepared in 5 min by solid state microwave cyclization of ortho-halobenzylidene barbiturates with yields above 90%. Molecular modeling simulations indicate as mechanism an intramolecular hetero Diels-Alder cyclization followed by loss of HX leading to rearomatization

http://dx.doi.org/10.1590/S0103-50532011001100012

Published online: September 6, 2011


J. Braz. Chem. Soc. 2011, 22(11), 2108-2114

Local Electrochemical Investigation of Single Grains of Polycrystalline Cu-16%Zn-8%Al Alloy

José T. C. Barragan; Matildes Blanco; Nilso Barelli; Rodrigo Della Noce; Cecílio S. Fugivara; Javier Fernández; Assis V. Benedetti

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Micrograph of single grains of polycrystalline Cu-16%Zn-8%Al alloy obtained by petrographic microscopy

http://dx.doi.org/10.1590/S0103-50532011001100013

Published online: September 8, 2011

J. Braz. Chem. Soc. 2011, 22(11), 2115-2120

Action of Successive Heat Treatments in Bovine Milk Fatty Acids

Edvaldo N. Costa; Ellen C. Q. Lacerda; Suian M. S. Santos; Carilan M. S. Santos; Marcelo Franco; Robério R. Silva; Julliana I. Simionato

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In octadienoic acid profiles to raw, pasteurized and sterilized milk samples occurs significant difference between raw and UHT milks for CLAc9t12 and 18:2c9c12 and no difference between raw and UHT milks for CLAt10c12. This fact evidences the successive action of heat treatments on milk lipid profile

http://dx.doi.org/10.1590/S0103-50532011001100014

Published online: September 13, 2011


J. Braz. Chem. Soc. 2011, 22(11), 2121-2126

Comprehensive Two-Dimensional Gas Chromatography with Time of Flight Mass Spectrometry Applied to Analysis of Fischer-Tropsch Synthesis Products Obtained with and without Carbon Dioxide Addition to Feed Gas

Raphael S. F. Silva; Juliana B. Tamanqueira; Julio César M. Dias; Fábio M. Passarelli; Antonio Marcos F. Bidart; Francisco R. Aquino Neto; Débora A. Azevedo

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Selected region of a chromatogram obtained by comprehensive two-dimensional gas chromatography of synthetic fuels produced by Fischer-Tropsch synthesis. High level of resolution for n-alkanes, branched alkenes, alkenes and n-alcohols analysis was promoted by this technique

http://dx.doi.org/10.1590/S0103-50532011001100015

Published online: September 13, 2011

J. Braz. Chem. Soc. 2011, 22(11), 2127-2138

Distribution of Indoor Air Pollutants in Downtown Rio de Janeiro, Brazil

Celeste Y. S. Siqueira; Adriana Gioda; Fabiana P. Carneiro; Maria da Conceição K. V. Ramos; Francisco R. Aquino Neto

How to cite this article

 

Total volatile organic compound (TVOC) concentrations ranged from 101 to 12823 μg m-3, with an average of 1594 μg m-3 that exceeds the suggested limit (300 μg m-3). Indoor/outdoor ratios for most of the parameters were higher than unit, indicating indoor sources of pollution. Overall, the environments did not present good air quality for the occupants due to chemical pollutants

http://dx.doi.org/10.1590/S0103-50532011001100016

Published online: September 20, 2011

J. Braz. Chem. Soc. 2011, 22(11), 2139-2147

Characterization of Dissolved Organic Matter in the Piauí River Estuary, Northeast Brazil

Adnivia Santos Costa; Elisangela de Andrade Passos; Carlos A. B. Garcia; José do Patrocinio H. Alves

How to cite this article

 

Fluorescence spectroscopy was used to accompany the evolution of DOM during the mixing of fluvial and marine waters in the Piauí River estuary, which is a tropical estuary situated in the State of Sergipe, Northeast Brazil

http://dx.doi.org/10.1590/S0103-50532011001100017

Published online: September 20, 2011


J. Braz. Chem. Soc. 2011, 22(11), 2148-2156

Enzymatic Synthesis Optimization of Isoamyl Butyrate

Andréia Anschau; Vitor C. Aragão; Barbara D. A. Porciuncula; Susana J. Kalil; Carlos A. V. Burkert; Janaína F. M. Burkert

How to cite this article

 

Lipozyme TL IM was used to catalyse the esterification of isoamyl alcohol and butyric acid using hexane as solvent. The reaction was carried out in shaking incubator and the percent of isoamyl butyrate and its concentration was determined by titration

http://dx.doi.org/10.1590/S0103-50532011001100018

Published online: September 23, 2011

J. Braz. Chem. Soc. 2011, 22(11), 2157-2164

Automation of an Analysis System with Microvolume Porous Membrane Sampling, Capillary Electrophoresis Separation and Contactless Conductivity Detection for Near-Real-Time Monitoring of Traces of Low-Molecular-Weight Carboxylic Acids in Air

Lúcia H. G. Coelho; Ivano G. R. Gutz

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Automated CMDS-CE-C4D system for the near-real-time monitoring of low-molecular-weight carboxylic acids in air

http://dx.doi.org/10.1590/S0103-50532011001100019

Published online: September 23, 2011

J. Braz. Chem. Soc. 2011, 22(11), 2165-2170

Dual Bifunctional Catalysis and the α-Effect in the Reaction of Hydroxylamine with Phenylacetate

Deise J. Mazera; Josefredo R. Pliego Jr.; Gizelle I. Almerindo; José C. Gesser

How to cite this article

 

Dual bifunctional catalysis plays an important role in the α-effect for the reaction of hydroxylamine with phenylacetate

http://dx.doi.org/10.1590/S0103-50532011001100020

Published online: September 27, 2011

J. Braz. Chem. Soc. 2011, 22(11), 2171-2177

Determination of Sulfamethoxazole in Pharmaceutical Formulations by Flow Injection System/HPLC with Potentiometric Detection using Polypyrrole Electrode

Sabriye P. Ozkorucuklu; Yucel Sahin; Guleren Alsancak

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The use of polypyrrole (PPy) as a potentiometric detector in high performance liquid chromatography (HPLC) for determination of sulfamethoxazole is reported in this work. The PPy electrode was successfully applied as a potentiometric detector for fast and accurate determination of sulfamethoxazole in standards and pharmaceutical samples

http://dx.doi.org/10.1590/S0103-50532011001100021

Published online: September 29, 2011

J. Braz. Chem. Soc. 2011, 22(11), 2178-2185

A Monte Carlo Revisiting of N-Methylformamide and Acetone

Glauco G. Almeida; João M. M. Cordeiro

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Is there anything else to be learned about the structure of liquids N-methylformamide and acetone? Yes, there is!

http://dx.doi.org/10.1590/S0103-50532011001100022

Published online: October 4, 2011

J. Braz. Chem. Soc. 2011, 22(11), 2186-2190

DBU as a Catalyst for the Synthesis of Amides via Aminolysis of Methyl Esters

Evanoel Crizanto de Lima; Carolina C. de Souza; Renato de O. Soares; Boniek Gontijo Vaz; Marcos N. Eberlin; Ayres G. Dias; Paulo R. R. Costa

How to cite this article

 

Use of DBU as an efficient catalyst for the chemoselective aminolysis of methyl esters leading to amides, as tested by the reactions employing esters and amines

http://dx.doi.org/10.1590/S0103-50532011001100023

Published online: October 4, 2011


J. Braz. Chem. Soc. 2011, 22(11), 2191-2201

The Effect of Different Chemical Treatments on the Structure and Stability of Aqueous Dispersion of Iron- and Iron Oxide-Filled Multi-Walled Carbon Nanotubes

Rodrigo A. Moraes; Carolina F. Matos; Eryza G. Castro; Wido H. Schreiner; Marcela M. Oliveira; Aldo J. G. Zarbin

How to cite this article

 

The homogeneity, surface chemistry, structure and dispersibility in water of iron- and iron oxide-filled multi-walled carbon nanotubes are affected by different chemical treatments

http://dx.doi.org/10.1590/S0103-50532011001100024

Published online: October 6, 2011


J. Braz. Chem. Soc. 2011, 22(11), 2202-2205

Alum-Catalyzed One-Pot Synthesis of Dihydropyrano[3,2-b] chromenediones

Wei Lin Li; Li Qiang Wu; Fu Lin Yan

How to cite this article

 

A simple, green and efficient solventless procedure for the synthesis of eleven dihydropyrano[3,2-b]chromenediones from the threecomponent condensation reaction of kojic acid, aromatic aldehydes, and dimedone employing alum as reusable catalyst is described

http://dx.doi.org/10.1590/S0103-50532011001100025

Published online: October 6, 2011


J. Braz. Chem. Soc. 2011, 22(11), 2206-2215

A Second-Order Standard Addition Method based on the Data Treatment by Calculation of Variation Matrix of Kinetic Systems Analyzed by MCR-ALS

Abdolhossein Naseri; Morteza Bahram; Mehdi Mabhooti

How to cite this article

 

A new second-order standard addition method is proposed to resolve the kinetic-spectrophotometric data of multicomponent mixtures and determination of analyte(s) in the presence of unknown matrix. The method uses variation matrices data by shifting to another target, namely the reaction space

http://dx.doi.org/10.1590/S0103-50532011001100026

Published online: October 6, 2011

Short Reports J. Braz. Chem. Soc. 2011, 22(11), 2216-2219

Alkaloid and other Chemical Constituents from Psychotria stachyoides Benth

Antonia T. A. Pimenta; Daniel E. A. Uchôa; Raimundo Braz-Filho; Edilberto R. Silveira; Mary Anne S. Lima

How to cite this article

 

A complete structural characterization is presented for the new alkaloid N-demethylcorreantoside, isolated from the leaves of Psychotria stachyoides

http://dx.doi.org/10.1590/S0103-50532011001100027

Published online: August 25, 2011


J. Braz. Chem. Soc. 2011, 22(11), 2220-2224

Microwave Irradiation or Low Temperature Improved Synthesis of Antiparasitic Morita-Baylis-Hillman Adducts

Claudio G. L. Junior; Fábio P. L. Silva; Ramon G. de Oliveira; Fernanda L. Subrinho; Natália G. de Andrade; Mário L. A. A. Vasconcellos

How to cite this article

 

We report the synthesis of 24 Morita-Baylis-Hillman adducts using microwave irradiation at 80 °C or conventional protocol at 0 °C to promote the reactions in high yields (81-99%)

http://dx.doi.org/10.1590/S0103-50532011001100028

Published online: August 25, 2011


J. Braz. Chem. Soc. 2011, 22(11), 2225-2233

Effect of the Subsampling Ratio in the Application of Subagging for Multivariate Calibration with the Successive Projections Algorithm

Arlindo R. Galvão Filho; Roberto K. H. Galvão; Mário César U. Araújo

How to cite this article

 

Multi-criterion analysis of the effects of subsampling ratio q on the subagging approach for multiple linear regression with variable selection by the successive projections algorithm

http://dx.doi.org/10.1590/S0103-50532011001100029

Published online: September 15, 2011

J. Braz. Chem. Soc. 2011, 22(11), 2234-2238

A New Megastigmane Diglycoside from Litsea glutinosa (Lour.) C. B. Rob.

Yun-Song Wang; Zhen Liao; Yan Li; Rong Huang; Hong-Bing Zhang; Jing-Hua Yang

How to cite this article

 

Phytochemical study on the leaves and twigs of Litsea glutinosa (Lour.) C. B. Rob. afforded the new megastigmane diglycoside (6S, 7E, 9R)-6, 9-dihydroxy-4, 7-megastigmadien-3-one-9-O-[α-L-arabinofuranosyl-(1→6)]-β-d-glucopyranoside (1), along with four known glycosides (2-4)

http://dx.doi.org/10.1590/S0103-50532011001100030

Published online: September 29, 2011

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