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http://rvq.sbq.org.br Melhoria no Ponto de Fluidez de Óleos Pesados pela Adição de Solventes OrgânicosResumo: Este artigo descreve o comportamento do ponto de fluidez de três óleos pesados com adição de querosene, aguarrás, tolueno e condensado de gás. O estudo mostrou um decaimento no ponto de fluidez de todos os óleos que se relaciona com a composição química dos óleos. O óleo com menor grau API (maior quantidade de asfaltenos e resinas) apresentou maior decaimento do ponto de fluidez para todos os solventes, destacando o condensado de gás e a aguarrás. O uso de condensado de gás para reduzir o ponto de fluidez de óleos pesados é particularmente vantajoso, quando disponível no campo petrolífero. Previne a paralisação na produção de óleo, devido a obstrução e problemas de fluxo nos dutos, e facilita a logística, reduzindo os custos operacionais do processo.Palavras-chave: Óleos pesados; ponto de fluidez; solventes orgânicos. AbstractThis paper describes the pour point behavior of three heavy oils with the addition of kerosene, turpentine, toluene and gas condensate. The study showed a decrease in the pour point of all oils related to their chemical composition. The oil with the lowest API gravity (high amount of asphaltenes and resins) showed the highest pour point decay for all solvents, highlighting gas condensate and turpentine. The use of gas condensate to reduce the pour point of heavy oils is particularly advantageous, when it is available in the oilfield. It also prevent halt in oil production, due to pipeline clogging and flow problems, and facilitate the logistics, reducing operational costs in the process.

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Beer is one of the oldest alcoholic beverages consumed by humanity, having been discovered about 7.000 years ago. When consumed in moderate quantities, beer can bring similar health benefits to wine. Despite the great economic, cultural and scientific importance of beer, there are few reports in Portuguese literature focused on the topic. In this sense, the main objective of this paper is to gather information in the scientific literature about the chemical aspects involved in brewing, as well as the analytical techniques used in their characterization, authentication and control of the productive processes, and the biological activities that compounds of beer ownes. Beer is produced basically by four essential ingredients: water, malt, hops and yeast. These ingredients are handled in seven steps: milling, mashing, boiling, fermenting, conditioning, filtering, and packaging. At the final stage of production, manufactures can evaluate physicochemical properties of the beer, of which it is highlighted alcohol content, bitterness, color, and pH. In the identification of beer compounds, as well as in the authentication and control of production processes, can be used analytical techniques such as infrared (IR) spectroscopy, hydrogen nuclear magnetic resonance (1 H NMR), mass spectrometry (MS) and gas Chromatography coupled to mass spectrometry (GC-MS). In addition, studies on the biological activities of compounds present in the beer reveal an antioxidant, anti-inflammatory, antimicrobial, antitumor potential, among others, noting that moderate consumption of the beverage can bring benefits to the health of consumers. A cerveja é uma das bebidas alcoólicas mais antigas consumidas pela humanidade, tendo sido descoberta há cerca de 7.000 anos. Quando consumida em quantidades moderadas, a cerveja pode trazer benefícios a saúde semelhantes aos do vinho. Apesar da grande importância econômica, cultural e científica que a cerveja possui, percebe-se a escassez de uma literatura em português voltada ao tema. Neste sentido, o presente trabalho tem como objetivo reunir informações presentes na literatura científica, apresentando os aspectos químicos envolvidos na produção cervejeira, as técnicas analíticas empregadas na sua caracterização, autenticação e controle dos processos produtivos, assim como as atividades biológicas que a cerveja possui. Durante a produção da bebida são utilizados quatro ingredientes essenciais: água, malte, lúpulo e levedura. Esses ingredientes são manipulados em sete etapas: moagem, mostura, fervura, fermentação, maturação, filtração e envase. Ao final de sua produção a bebida pode ser avaliada quanto as suas propriedades físico-químicas, das quais destacamos: pH, amargor, cor e teor alcoólico. Na identificação dos compostos presentes na cerveja, bem como na autenticação e controle dos processos produtivos, podem ser empregadas técnicas analíticas, tais como a espectroscopia na região do infravermelho (IV), a ressonância magnética nuclear de hidrogênio (RMN 1 H), a espectrometria de massas (EM) e a c...

Abstract:: There is great interest in developing chemical technologies to achieve regioselective and stereoselective reactions since only one enantiomer is required for producing the chiral leads for drug development. These selective reactions are dif-ficultly provided by traditional chemical synthetic methods, even under expensive catalysts and long reaction times. Fila-mentous fungi are efficient biocatalysts capable of catalyzing a wide variety of reactions with significant contributions to the development of clean and selective processes. Although some enzymes have already been employed in isolated forms or as crude protein extracts as catalysts for conducting selective reactions, the use of whole-cell provides advantages regarding cofactor regenerations. It is also possible to carry out conversions at chemically unreactive positions and to perform racemic resolution through microbial transformation. The current literature contains several reports on the biotransformation of dif-ferent compounds by fungi, which generated chemical analogs with high selectivity, using mild and eco-friendly conditions. Prompted by the enormous pharmacological interest in the development of stereoselective chemical technologies, this re-view covers the biotransformations catalyzed by fungi that yielded chiral products with enantiomeric excesses published over the period 2010-2020. This work highlights new approaches for the achievement of a variety of bioactive chiral build-ing blocks, which can be a good starting point for the synthesis of new compounds combining biotransformation and syn-thetic organic chemistry.