Perfil térmico de rutina proveniente da fava d’anta (Dimorphandra gardneriana Tulasne) / Thermal profile of rutina from fava d'anta (Dimorphandra gardneriana Tulasne)

Dimorphandra gardneriana Tulasne é conhecida como fava d’anta, é uma árvore brasileira, naturalmente do Cerrado e Caatinga, têm uma importância ecológica e funcional, seus frutos são ricos em flavonoides (rutina, quercetina, isoquercitrina). O objetivo deste trabalho foi estudar a estabilidade térmica da fava d’anta e da rutina purifica através da termogravimetria. As amostras foram analisadas no Termogravimétrico Shimadzu, TGA-51, no Laboratório de Materiais do IFPI, onde foram acondicionadas em porta-amostras de platina, com atmosfera de nitrogênio e com fluxo de 50 mL/min. A temperatura foi elevada a 600°C, com taxa de aquecimento de 2 °C/min. Obteve-se sucesso com a purificação da fava d’anta, pois a rutina obtida teve maior uniformidade nos eventos térmicos e maior estabilidade térmica em relação a fava.

Development and validation of a HPLC method for the quantification of three flavonoids in a crude extract of Dimorphandra gardneriana

A method for separation and quantification of three flavonoids by reverse-phase high performance liquid chromatography (HPLC) was developed and validated. Flavonoids present in a crude methanolic extract of the inner bark of Dimorphandra gardneriana Tul., Fabaceae, were analyzed. Rutin, isoquercitrin and quercetin were used as calibration standards. The analysis was performed using a Thermo Scientific Hypersil C18 column (250 x 4.0 mm i.d., 5 μm particle size), as stationary phase, with a flow rate of 0.8 mL/min and detection at a wavelength of 356 nm. The proposed method was validated by resolution RE No. 899/2003 of the National Health Surveillance Agency. In this study, an excellent linearity was obtained with r higher than 0.99. Besides, the chromatographic peaks showed good resolution. With other validation data, including precision, specificity, accuracy and robustness, this method demonstrated good reliability and sensitivity, and can be conveniently used for the quantification of rutin, isoquercitrin and quercetin in crude methanolic extract of D. gardneriana pods. Furthermore, there are the advantages of easy sample preparation and short time between each injection.

Leishmanicidal and cholinesterase inhibiting activities of phenolic compounds of Dimorphandra gardneriana and Platymiscium floribundum, native plants from Caatinga biome / Atividade inibitória Leishmanicida e Colinesterásica de Compostos Fenólicos de Dimorphandra gardneriana e Platymiscium fliribunbum, plantas nativas do bioma Caatinga

In recent years, the Brazilian Health Ministry and the World Health Organization have supported research into new technologies that may contribute to the surveillance, new treatments, and control of visceral leishmaniasis within the country. In light of this, the aim of this study was to isolate compounds from plants of the Caatinga biome, and to investigate their toxicity against promastigote and amastigote forms of Leishmania infantum chagasi, the main responsible parasite for South American visceral leishmaniasis, and evaluate their ability to inhibit acetylcholinesterase enzyme (AChE). A screen assay using luciferase-expressing promastigote form and an in situ ELISA assay were used to measure the viability of promastigote and amastigote forms, respectively, after exposure to these substances. The MTT colorimetric assay was performed to determine the toxicity of these compounds in murine monocytic RAW 264.7 cell line. All compounds were tested in vitro for their anti-cholinesterase properties. A coumarin, scoparone, was isolated from Platymiscium floribundum stems, and the flavonoids rutin and quercetin were isolated from Dimorphandra gardneriana beans. These compounds were purified using silica gel column chromatography, eluted with organic solvents in mixtures of increasing polarity, and identified by spectral analysis. In the leishmanicidal assays, the compounds showed dose-dependent efficacy against the extracellular promastigote forms, with an EC50 for scoporone of 21.4µg/mL, quercetin and rutin 26 and 30.3µg/mL, respectively. The flavonoids presented comparable results to the positive control drug, amphotericin B, against the amastigote forms with EC50 for quercetin and rutin of 10.6 and 43.3µg/mL, respectively. All compounds inhibited AChE with inhibition zones varying from 0.8 to 0.6, indicating a possible mechanism of action for leishmacicidal activity.

Nos últimos anos, o Ministério da Saúde do Brasil e a Organização Mundial da Saúde tem apoiado a investigação de novas tecnologias que possam contribuir para a vigilância, novos tratamentos e controle da leishmaniose visceral no país. Assim, o objetivo deste trabalho foi isolar compostos de plantas do bioma Caatinga, e investigar a toxicidade destes compostos contra as formas promastigotas e amastigotas de Leishmania infantum chagasi, principal parasita responsável pela leishmaniose visceral na América do Sul, e avaliar a sua capacidade para inibir a enzima acetil-colinesterase (AChE). Após a exposição aos compostos em estudo, foram realizados testes utilizando a forma promastigota que expressa luciferase e ELISA in situ para medir a viabilidade das formas promastigotas e amastigota, respectivamente. O ensaio colorimétrico MTT foi realizado para determinar a toxicidade destas substâncias utilizando células monocíticas murina RAW 264.7. Todos os compostos foram testados in vitro para as sua propriedade anti-colinesterásica. Um cumarina, escoparona, foi isolada a partir de hastes de Platymiscium floribundum, e os flavonóides, rutina e quercetina, foram isolados a partir de grãos de Dimorphandra gardneriana. Estes compostos foram purificados, utilizando cromatografia em coluna gel eluída com solventes orgânicos em misturas de polaridade crescente, e identificados por análise espectral. Nos ensaios leishmanicidas, os compostos fenólicos mostraram eficácia contra as formas extracelulares promastigotas, com EC50 para escoporona de 21.4µg/mL e para quercetina e rutina 26 e 30.3µg/mL, respectivamente. Os flavonóides apresentaram resultados comparáveis à droga controle, a anfotericina B, contra as formas amastigotas com EC50 para quercetina e rutina de 10.6 e 43.3µg/mL, respectivamente. Os compostos inibiram a enzima AChE com halos de inibição variando de 0,8 a 0,6cm, indicando um possível mecanismo de ação para a atividade leishmanicida.