Navegando por Autor "Meireles, Maria Angela de Almeida"
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Artigo Anticancer activity of Tabernaemontana catharinensis extract obtained by supercritical fluid extraction(Sociedade Brasileira de Plantas Medicinais, 2006-10-31) Courtial, Camila Gambini Pereira; Carvalho, J. E.; Meireles, Maria Angela de AlmeidaIn the present work the anticancer of crude supercritical fluid extract from T. catharinensis was evaluated. The crude extract was obtained using supercritical CO² at pressure of 300 bar and temperature of 55º C; ethanol was used as cosolvent (4.6% mass). The anticancer activity was tested against seven human cancer cell lines: lung, breast, breast expressing rhe multidrug resistance phenotype, melanoma, colon, prostate, and, kidney. The crude extract was fractionated and the alkaloidal fraction was analyzed by thin-layer chromatografy (TLC), and gas-chromatography/flame ionization detector (GC-FID). The GC-FID of the alkaloidal fraction indicated the presence of the indole alkaloids voacangine and coronaridine. The crude extract of T. catharinensis has anticancer activity that begins at 0.25 ug/mL and exhibits cytostatic and cytolytic effects concentration dependent and noy selective for the cell lines usedArtigo 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 SovováArtigo Leishmanicidal activity of a supercritical fluid fraction obtained from Tabernaemontana catharinensis(Elsevier, 2007-06) Soares, Deivid Costa; Courtial, Camila Gambini Pereira; Meireles, Maria Angela de Almeida; Saraiva, Elvira MariaThe branches and leaves of Tabernaemontana catharinensis were extracted with supercritical fluid using a mixture of CO2 plus ethanol (SFE), and the indole alkaloid enriched fraction (AF3) was selected for anti-Leishmania activity studies. We found that AF3 exhibits a potent effect against intracellular amastigotes of Leishmania amazonensis, a causative agent of New World cutaneous leishmaniasis. AF3 inhibits Leishmania survival in a dose-dependent manner, and reached 88% inhibition of amastigote growth at 100 μg/mL. The anti-parasite effect was independent of nitric oxide (NO), since AF3 was able to inhibit NO production induced by IFN-γ plus LPS. In addition, AF3 inhibited TGF-β production, which could have facilitated AF3-mediated parasite killing. The AF3 fraction obtained from SFE was nontoxic for host macrophages, as assessed by plasma membrane integrity and mitochondrial activity. We conclude that SFE is an efficient method for obtaining bioactive indole alkaloids from plant extracts. Importantly, this method preserved the alkaloid properties associated with inhibition of Leishmania growth in macrophages without toxicity to host cellsArtigo Supercritical fluid extraction from guava (Psidium guajava) leaves: global yield, composition and kinetic data(Elsevier, 2012-02) Moura, P. M.; Prado, Glaucia Helena Carvalho do; Meireles, Maria Angela de Almeida; Courtial, Camila Gambini PereiraThe aim of this work was to obtain guava leaf extracts using supercritical fluid extraction. The use of ethanol and isopropyl alcohol as co-solvents was evaluated. In addition, mass transfer kinetics experiments were carried out and overall extraction curves were modeled. The global yield and extract composition from supercritical fluid extraction were compared with those from conventional extractions. The extracts were analyzed by thin layer chromatography (TLC) and gas chromatography–mass spectrometry (GC–MS). The results indicated the presence of essential oils, flavonoids and anti-oxidant compounds in all extracts. The highest global yield was observed with the Soxhlet extraction process. However, the extracts from supercritical fluid extraction had higher levels of functional compounds. Overall, the Sovová model best described the overall extraction curves