Núbia M. Ribeiro

Biodiesel: an overview

The importance of biodiesel production was analyzed based on scientific articles and patents. A critical analysis was presented on the most used oil sources, the catalysts and the methods to verify the transesterification yields. Also analyzed were the comparative studies on emissions from pure fossil diesel and mixtures with biodiesel in variable proportions. Finally some challenges and considerations focused on technological, agronomic and infrastructure aspects of biodiesel production were indicated.

Metodologia analítica para quantificar o teor de biodiesel na mistura biodiesel:diesel utilizando espectroscopia na região do infravermelho

Considered the best substitute for diesel, biodiesel can be blended with diesel in any ratio, bringing lots of environmental, economic and social advantages. Brazilian law No 11097/2005, proposes the introduction of biodiesel in to the Brazilian energy matrix, mixed with diesel at a minimum percentage of 2%. For consumers and sellers to be sure that the commercialized mixture of biodiesel:diesel contains the correct percentage, it is necessary to develop analytical methodologies to quantify the amount of biodiesel added. This work presents a fast, low-cost and simple methodology to determine the biodiesel proportion in mixtures of biodiesel:diesel, based on infrared spectroscopy.

Synthesis of ferrocenyl oxindole compounds with potential anticancer activity

Compostos oxindol-ferrocenos com potencial atividade anticâncer foram preparados a partir de reacoes de oxindois substituidos e carboxaldeido-ferroceno na presenca de KOH como catalisador. Os produtos foram caracterizados por dados espectroscopicos incluindo RMN de 1H e 13C, infravermelho e espectrometria de massas. As configuracoes E e Z foram estabelecidas por experimentos de nOe ou NOESY.

Synthesis, electrochemical studies and anticancer activity of ferrocenyl oxindoles

A series of (E) and (Z)-ferrocenyl oxindoles were prepared by coupling substituted oxindoles to ferrocenylcarboxyaldehyde in the presence of morpholine as a catalyst. The redox behavior of these isomers was determined by cyclic voltammetry. The effects of the oxindole derivatives on the migration of human breast cancer cells were evaluated using the wound-healing assay and the Boyden chamber cell-migration assay. The most potent Z isomers 11b (IC(50) = 0.89 microM), 12b (IC(50) = 0.49 microM) and 17b (IC(50) = 0.64 microM) could represent attractive new lead compounds for further development for cancer therapy.

INFORMAÇÃO DE PATENTES: FERRAMENTA INDISPENSÁVEL PARA A PESQUISA E O DESENVOLVIMENTO TECNOLÓGICO

As technological information is published mainly as a patent, it is fundamental for the country development to know the patent system. In this article it is presented basic information on intellectual property, in special on patent. It is showed the structure of the patent documents, and it is given notions on International Classification and patent data banks.

5-CHLORO- AND 5,7-DICHLOROISATIN BY CHLORINATION OF ISATIN WITH TRICHLOROISOCYANURIC ACID

Isatin derivatives have important biological and pharmacological properties. In particular, ketals of 5-haloisatin exhibit anticonvulsant’ and ansiolitic2 activities. The classical method to prepare isatins first reported by Sandme~er ,~ .~ requires several reagents and may produce hydrogen cyanide as a by-product? and the yields vary between 70 to 85%. 5-Chloroisatin and 5bromoisatin can also be prepared from isatin using chlorine or bromine respectively, but these reagents are toxic, corrosive, and can lead to other products. Alternativelly, halogenation of isatin can be performed by N-haloamides: N-haloimides’ or N-halosaccharins.8 As we needed large amounts of 5-chloroisatin to prepare derivatives for pharmacological tests, we evaluated the use of trichloroisocyanuric acid (TCCA), a safe, low-cost and efficient halogenating agent.9 We now report the reaction of isatin with TCCA to prepare 5-chloroand 5,7-dichloroisatins. The solvent-free method is rapid, efficient and requires very simple manipulations. Trichloroisocyanuric acid reacts with isatin in the presence of sulfuric acid to produce 5chloroisatin (1) or 5,7-dichloroisatin (2), depending mainly on the ratio of isatin:TCCA.

Todos os Santos Bay Research Program: Response to the Complexity of the Demands for Knowledge

This article proposes a reflection on new research designs – long-term transdisciplinary studies – to favor the investigation of complex phenomena, such as those concerning with ecosystems and human activities. Chemistry has an important role in these designs, by promoting the dialogue between different fields of knowledge. To enrich this reflection, this article presents the experience of the Todos os Santos Bay (BTS) Research Program that began in 2007, with longitudinal horizon of 30 years of study. Despite the challenges, such as the difficulty of establishing a common language or the demand for a transdisciplinary capacity building, this type of research design indicates a trend, that is expected to be irreversible in the science, technology and innovation (C, T & I) current scenario to act upon the increasing complexity of the socio-environmental phenomena and the societys demand for solutions that contribute to a better life.