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Este trabalho compara pela primeira vez a composição química do óleo essencial das folhas de Licaria canella coletadas em duas estações climáticas. Os resultados foram comparados com os obtidos para o óleo essencial das folhas de outra espécie da família Lauraceae, Aniba canelilla, coletada no mesmo período. Ambos os óleos essenciais foram analisados por CG-DIC e CG-EM, e os resultados indicaram uma grande quantidade de benzenóides, sendo o principal constituinte em L. canella o benzoato de benzila e para A. canelilla, o 1-nitro-2-feniletano. A comparação das atividades biológicas mostrou que o óleo de L. canella (IC 50 19 µg mL-1) foi mais ativo contra as cepas de Leishmania amazonensis e menos citotóxico em cultura de macrófagos do que o de A. canelilla (IC 50 40 µg mL-1). Por outro lado, o óleo de L. canella exibiu uma maior citotoxicidade contra Artemia salina com uma concentração letal (CL 50) igual a 5,25 µg mL-1. This work compares the chemical composition of the essential oils from the leaves of Licaria canella collected in two different seasons. The results of this investigation were compared with the leaf essential oils of other species of the Lauraceae family, Aniba canelilla, collected at the same time. Both essential oils were analyzed by GC-FID and GC-MS. The results demonstrated a larger predominance of benzenoids, being the main constituent benzyl benzoate for L. canella and 1-nitro-2-phenylethane for A. canelilla. The comparison of the biological activities showed that L. canella (IC 50 19 µg mL-1) was more active against Leishmania amazonensis strains and less cytotoxic in macrophage cultures than A. canelilla (IC 50 40 µg mL-1). On the other hand, the L. canella oil displayed a higher cytotoxicity against Artemia salina with a lethal concentration (LC 50), equal to 5.25 µg mL-1 .

A simple and rapid dual-wavelength spectroscopic method is used for simultaneous determination of pentoses and hexoses in the prehydrolyzate from lignocellulosic biomass. The method is based on the following reaction mechanism: in the solution of hydrochloric acid, phloroglucinol gives color reaction with sugars or their degradation products, showing maximum absorbance at 553 nm and 410 nm. Based on dual-wavelength spectrophotometric measurement, the pentoses and hexoses can separately be quantified. It was found that the derivatives from these two different sugars have an isosbestic point at 425 nm. According to the validation results, high accuracy and reasonable recovery rate is shown with the present method (pentoses recovery 97.1 to 100.0%, hexoses recovery 97.2 to 102.0%). Additionally, the interferences from substances including lignin, furfural, 5-hydroxymethyl furfural (HMF), glucuronic acid, and galacturonic acid are insignificant. All of the above results illustrate the suitability of this method for analyzing sugars in the lignocelluloses prehydrolyzate, especially hardwoods or herbaceous plants, based on forest-related biorefinery research. INTRODUCTION Resource and energy shortages have become widespread issues for global development. As one of the most abundant renewable resources, lignocelluloses show great potential for future development, such as the production of transportation fuels and other value-added chemicals, while yielding lower greenhouse gas emissions. In the paper industry, lignocellulosic biomass is usually used for the production of chemical pulps, typically by alkaline pulping process. During the pulping process, a large amount of carbohydrates, mainly hemicelluloses, are released into the pulping liquor, which increases the loading in the spent liquor (black liquor) and provides few benefits (due to the lower heating value) to liquor combustion in the chemical recovery process. One of the key processes in the proposed "Integrated Forest Biorefinery" (van Heiningen 2006) is the pre-extraction of hemicelluloses for the production of fuel-based ethanol or biodiesel. In the prehydrolysis research, it is important to seek efficient methods and conditions for achieving a controlled sugar extraction yield (mainly from hemicelluloses) with minimum cellulose degradation. Data from the sugar content in the prehydrolyzate provides important information for better understanding the effects of the process PEER-REVIEWED ARTICLE bioresources.com Chi et al. (2013). "Sugar analysis of hydrolysates," BioResources 8(1), 172-181. 173 parameters, such as reaction temperature, time, acidity, alkalinity, etc., as they relate closely to the degree of hemicellulose hydrolysis and cellulose degradation. Many traditional methods are available for sugar analysis. Colorimetric methods, including the dinitrosalicylic acid (DNS) assay (Miller 1959), the orcinol-sulfuric acid method (Scott and Melvin 1953), and the phenol-sulfuric acid method (Dubois et al. 1956), can just be used for quantifying total reducin...

RESUMO-A transesterificação de óleos vegetais com alcoóis é o método mais utilizado na síntese de biodiesel, geralmente ocorrendo em batelada. Porém, atualmente essa produção vem sendo explorada em microreatores, devido aos seus curtos tempos de residência com elevadas conversões. Em virtude disso, esse trabalho estudou a síntese de biodiesel em microreatores a partir do óleo vegetal de girassol e etanol utilizando como catalisador hidróxido de sódio. Na síntese do biodiesel foi estudada a influência das variáveis: temperatura, razão etanol/óleo e concentração do catalisador. Foi feita uma comparação entre os métodos de reação em batelada e em microreatores. A máxima porcentagem de biodiesel encontrada para a reação em batelada e em microreatores foi de 88% e 95,8%, respectivamente. Os resultados comprovaram a eficiência dos microreatores na síntese de biodiesel.

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