Abstract The aim of this study was to investigate the effects of yerba mate (Ilex paraguariensis St. Hil.) extract (YME) on oxidative stress parameters and pathological changes in the lungs of mice chronically exposed to hand-rolled cornhusk cigarette (HRC) smoke. Twenty-four male Swiss mice were divided into four groups exposed to the following treatments: control (ambient air), HRC, YME, and HRC plus YME. The animals were exposed to four HRCs per session, with 3 sessions/day, every day for 30 days. Twenty-four hours after the last inhalation, the mice were killed, and the left lungs were removed. The results showed that HRC contains elevated levels of tin and carbon oxide, but less arsenic, cobalt, manganese, and selenium than commercial cigarettes. YME administration reversed fibrosis, alveolar enlargement, and hemorrhage induced by HRC smoke. In addition, the YME and HRC significantly reduced the production of oxidants, oxidative damage and promoted a significant increase in total thiol. In conclusion, exposure to HRC smoke compromised pulmonary histoarchitecture by promoting structural changes and increasing oxidative stress in tissues. However, concomitant treatment with YME regulated the redox state and reduced the harmful effects of HRC smoke exposure in the lungs.

This study reports the optimization of geranyl butanoate production by esterification of geraniol and butanoic acid in a solvent-free system using two immobilized lipases as catalyst. The operating conditions that optimized geranyl butanoate production were determined to be 40 °C, a geraniol to butanoic acid molar ratio of 3:1, 150 rpm, 5 wt% of enzyme, and 1 h of reaction, which resulted in a reaction conversion of about 97% for Novozyme 435. When homemade Novozyme NZL-102-LYO-HQ (Cal-B) immobilized in polyurethane foam was used as catalyst, the experimental conditions of an alcohol to acid molar ratio of 5:1, 70 °C, 150 rpm, 5 wt% of enzyme, and 1 h of reaction gave a conversion of 95%. New experimental data on enzymatic esterification of geraniol and butanoic acid for geranyl butanoate production are reported in this work, showing that the technique is promising for overcoming the well-known drawbacks of the chemical-catalyzed route.

Candida antarctica lipase B (CALB) is an enzyme able to catalyze chemical reaction, however when it is used as a free enzyme, it cannot be recovered from reaction medium. One of the alternatives is to immobilize the enzymes on a support which allows the maintenance of their catalytic activities. The purpose of this paper was to immobilize the CALB on MCM-48 using the ionic solid [C16MI]Cl as structure director. 22 CCRD (Central Composite Rotational Design) was proposed to analyze the influence of the variables like enzyme mass (0.059 to 0.341 g) and ionic solid concentration (0.59 to 3.41%) in the enzyme immobilization process to obtain the maximum esterification activity in order to optimize the process. After immobilization, the study results showed that the enzymes exhibited improvement of thermal (40, 60 and 80 ºC) and storage stability (90 days), besides the possibility to reuse of the enzyme up to 10 times, showing residual activity of 50%.

ABSTRACT The present study evaluated the purification of inulinase by changing the ionic strength of the medium by addition of NaCl and CaCl2 followed by precipitation with n-propyl alcohol or iso-propyl alcohol. The effects of the concentration of alcohols and the rate of addition of alcohols in the crude extract on the purification yield and purification factor were evaluated. Precipitation caused an activation of enzyme and allowed purification factors up to 2.4-fold for both alcohols. The purification factor was affected positively by the modification of the ionic strength of the medium to 0.5 mol.L-1 NaCl before precipitation with the alcohol (n-propyl or iso-propyl). A purification factor of 4.8-fold and an enzyme yield of 78.1 % could be achieved by the addition of 0.5 mol.L-1 of NaCl to the crude extract, followed by the precipitation with 50 % (v/v) of n-propyl alcohol, added at a flow rate of 19.9 mL/min.

Catalisadores Pd/γ-Al2O3 com dois tamanhos de partículas metálicas foram preparados a partir de [Pd(acac)2]. Subsequentemente, a reação fotoquímica de [M(CO)6] (M = Mo ou W) na presença de Pd/γ-Al2O3 foi usada para preparar catalisadores bimetálicos Pd-M/γ-Al2O3. Os espectros DRIFTS-IVTF das superfícies destes catalisadores antes da decomposição térmica mostraram espécies subcarbonilas [M(CO)n] instáveis. Resultados de quimissorção e adsorção de CO/NO indicaram um bloqueio dos sítios ativos do paládio quando o segundo metal foi incorporado. A atividade catalítica e a seletividade para N2 e O2 na reação NO/CO foram maiores para Pd com maior tamanho de partícula, mas foram inibidas quando Mo ou W foram incorporados. Por outro lado, quando esses catalisadores foram testados para a decomposição de NO, a presença de Mo ou W levou a um aumento da atividade catalítica e da seletividade, com os melhores resultados observados na presença de Mo.

Pd/γ-Al2O3 catalysts with two different metal particle sizes were prepared from [Pd(acac)2]. Subsequently, the photochemical reaction of [M(CO)6] (M = Mo or W) in the presence of Pd/γ-Al2O3 was used to prepare bimetallic Pd-M/γ-Al2O3 catalysts. DRIFTS FTIR spectra of the catalyst surfaces prior to thermal decomposition showed unstable subcarbonyl [M(CO)n] species. Chemisorption and CO/NO adsorption results indicated a blockage of the Pd active sites when the second metal was incorporated. The catalytic activity and the selectivity for the NO/CO reaction were higher for Pd with higher particle size, but they were both inhibited when Mo or W were incorporated. On the other hand, when the catalysts were tested for NO decomposition, the presence of Mo or W led to an increase in the catalytic activity, with optimal results observed in the presence of Mo.