Navegando por Autor "Rosa, Paulo de Tarso Vieira e"
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Artigo Extraction and isolation of indole alkaloids from Tabernaemontana catharinensis A.DC: technical and economical analysis(Elsevier, 2007-03) Courtial, Camila Gambini Pereira; Rosa, Paulo de Tarso Vieira e; Meireles, Maria Angela de AlmeidaIn the present work, the technical and economical analysis of extraction and isolation of indole alkaloids from Tabernaemontana catharinensis is presented. The extraction was carried out using supercritical CO2 as solvent and ethanol as cosolvent (5%, v/v). The global yield isotherms were determined at 35 and 45 ◦C for pressures of 150–350 bar. The mass transfer rate for the constant extraction rate period (CER), the duration of the CER period, and the mass ratio of solute in the fluid phase at the bed outlet were calculated. The extraction curves were adjusted by Crank, Goto et al. and Esqu´ıvel et al. models. The economical analysis was carried out considering that the cost of manufacturing can be obtained in terms of the costs of investment, operational labor, raw material, waste treatment and utilities. The higher global yields were obtained at 350 bar (1.30×10−2 and 1.54×10−2 kg/kg, at temperatures of 35 and 45 ◦C, respectively). The Goto’s model was able to quantitatively describe the experimental data. The cost of manufacturing the extracts obtained at 350 bar, 45 ◦C, using 5% (v/v) of ethanol was US$ 79.35 kg−1 of extract. Using previous experimental data obtained at 300 bar, 55 ◦C, using 10% of ethanol (v/v), the cost of manufacturing for the fractionation process to obtain a rich alkaloidal fraction (AF) was US$ 440.31 kg−1 of alkaloidsArtigo Extraction of volatile oil from Croton zehntneri Pax et Hoff with pressurized CO2: solubility, composition and kinetics(Elsevier, 2005-08) Chiavone Filho, Osvaldo; Sousa, Elisa Maria Bittencourt Dutra de; Martınez, Julian; Rosa, Paulo de Tarso Vieira e; Domingos, Tyrone; Meireles, Maria Angela de AlmeidaCroton zehntneri Pax et Hoff is indigenous to the Northeastern of Brazil; is rich in (E)-anethole and is largely used in cooking to impart flavor to a variety of foods; is used in folk medicine to treat indigestion, insomnia, etc. In this work the volatile oil from C. zehntneri was extracted using pressurized CO2. Both kinetic and solubility experiments were performed at pressures of 66.7 and 78.5 bar and temperatures from 10 to 28 °C. The composition of the volatile oil was determined using gas chromatography. The maximum solubility (2.83 × 10−2 kg/kg) was observed at 15 ° and 66.7 bar while the maximum global yield (3.4%, mass) was detected at 20 °C at the same pressure. The volatile oil was formed predominantly by (E)-anethole (73.6%, area), alpha muurolene (7.51%), methyl chavicol or estragole (2.52%), germacrene D (2.11%) and small amounts of other terpenoidic compounds. The overall extraction curves were fitted by several models from the literature. The models that best described the overall extraction curves were the Goto et al., Martínez et al., and Sovová