Rutin is found in several plant sources and has therapeutic effects with excellent healing potential. Its use is restricted due to its low aqueous solubility, requiring a carrier matrix that allows an adequate delivery system. Biopolymer matrices can release the active ingredient in a controlled manner, keeping it within the therapeutic range and minimizing side effects. This study used babassu mesocarp starch films prepared by different routes as Arrabidaea brachypoda DC Bureau (AB) leaf extract carrier matrices to produce a controlled release system. The films were produced by the casting method, and the AB extract was incorporated in the proportion of 0.5% m/m of dry starch. The presence of the extract in the matrix was identified with Fourier transform infrared spectroscopy (FTIR) and X-ray diffractometry (XRD) data and functional analyses. The in vitro release of the AB extract was carried out in phosphate-buffered saline, pH 7.4, and adapted to the Korsmeyer-Peppas model, with coefficients of determination (R2) ≥ 0.9018. The release exponents (n) revealed that the release mechanism is diffusion controlled. Different kinetic constant values (k) indicated that the treatments employed allowed slower and more controlled release profiles, according to the route chosen for matrix preparation. Thus, the materials produced emerge as a new approach to releasing vegetable extracts.

Clays such as smectite have high technical and economic viability due to their large adsorption capacity. These properties can be improved by treatment with acids or other modifications. This paper describes experiments to prepare and characterize organoclays and to evaluate their ability to remove oil from contaminated water in comparison with clay in its natural state. We used natural smectite clay from the municipality of Presidente Dutra, Maranhão State, modified with the quaternary ammonium salt cetyltrimethylammonium bromide. Characterization was performed by X-ray diffraction, Fourier transform infrared spectroscopy, X-ray fluorescence, thermogravimetry and determination of surface area by the Brunauer-Emmett-Teller (BET) method. The results showed appropriate conditions of the organophilization process, indicating the intercalation of quaternary ammonium cations between the clay layers. The adsorption tests showed that the natural clay reduced the amount of oil contained in the aqueous medium by 76.16%, while the corresponding removal rates of all organoclays tested were above 92%, which makes them potentially applicable to remove oil from wastewaters.

Os componentes mesocarpo e epicarpo do coco babaçu foram utilizados como novos biossorventes alternativos para remoção do corante têxtil ftalocianina de cobre de soluções aquosas. Esses biopolímeros foram caracterizados por análise elementar, RMN de 13C no estado sólido, espectroscopia de absorção na região do infravermelho, análise termogravimétrica e difratometria de raios X. Os resultados mostraram que a composição do mesocarpo e do epicarpo é similar à de outros materiais lignocelulósicos e que ambos os componentes são efetivos na remoção do corante têxtil Turqueza Remazol. O modelo cinético de pseudo-segunda ordem resultou no melhor coeficiente de correlação tanto para o epicarpo quanto para o mesocarpo (R² = 0,999), com constantes de velocidade de sorção, k2, de 0,31 e 1,43 g mg-1 min-1, respectivamente. Os modelos de Langmuir e Freundlich foram empregados para analisar os dados experimentais em sua forma linearizada. O segundo modelo apresentou melhor adequação para a adsorção do corante Turqueza Remazol com sorção máxima de 1,44 e 2,38 mg g-1 a pH 6,0 para mesocarpo e epicarpo, respectivamente.

The mesocarp and epicarp components of the babassu palm tree were applied as novel alternative biosorbents for copper phtalocyanine textile dye removal from aqueous solutions. The natural biopolymers were characterized by elemental analyses, solid state 13C NMR, infrared spectroscopy, thermogravimetric analysis and X-ray diffractometry. Results demonstrated that the compositions of the mesocarp and epicarp are similar to those of other lignocellulosic materials, and that they were very effective for removal of the textile dye Turquoise Remazol. A pseudo second-order kinetic model resulted in the best fit with experimental data for both epicarp and mesocarp (R² = 0.999), providing rate constants of sorption, k2, of 0.31 and 1.43 g mg-1 min-1, respectively. The Langmuir and Freundlich isotherm models were employed for adsorption analysis of the experimental data in their linearized forms. The second model resulted in the better fit for Turquoise Remazol dye, which presented maximum adsorption of 1.44 and 2.38 mg g-1 at pH 6.0 for mesocarp and epicarp, respectively.

A polimerização via metátese por abertura de anel (ROMP) de norborneno (NBE) ocorre em presença do complexo fac-[RuCl2(S-DMSO)3(O-DMSO)] e etildiazoacetato (5 μL), onde DMSO é dimetilsulfóxido coordenado pelo átomo de enxofre ou de oxigênio. O rendimento é 62% (PDI = 1,64) à temperatura ambiente por 5 min e 88% (PDI = 1,93) a 50 ºC por 30 min, com [NBE]/[Ru] = 516 em CHCl3. Na presença de NBu4ClO4 o rendimento é 90% (PDI = 1,64) à temperatura ambiente por 5 min. O complexo é praticamente inativo quando uma ou duas moléculas de DMSO são substituídas por piridina, imidazol, 2-metil-imidazol ou benzoimidazol. A formação in situ da espécie catalítica e os comportamentos das moléculas de DMSO como ligantes ancilares nas reatividades dos complexos de RuII são discutidas nesse trabalho.

The ring-opening metathesis polymerization (ROMP) of norbornene (NBE) occurs in the presence of the fac-[RuCl2(S-DMSO)3(O-DMSO)] complex and ethyldiazoacetate (5 μL), where DMSO is S- or O-bonded dimethylsulfoxide. The yield is 62% (PDI = 1.64) at room temperature for 5 min and 88% (PDI = 1.93) at 50 ºC for 30 min, with [NBE]/[Ru] = 516 in CHCl3. The yield is 90% (PDI = 1.64) in the presence of NBu4ClO4 at room temperature for 5 min. The complex is practically inactive when one or two molecules of DMSO are replaced by pyridine, imidazole, 2-methyl-imidazole or benzimidazole. The in situ formation of the catalytic species and the behavior of the DMSO molecules as ancillary ligands in the reactivity of the RuII complexes are discussed.

Some aspects of the olefin metathesis reactions are summarized here (types of reactions, mechanism and catalysts). In particular, the research groups that have been working on this chemistry in Brazil are presented. The main goal of this paper is to make this type of reaction more widely known in the Brazilian chemical community.