RESUMO

ABSTRACT In this work, we developed and validated a HPLC-PDA method for the quantification of hibalactone in Hydrocotyle umbellata L., Araliaceae, subterraneous parts extracts and optimized its ultrasound-assisted extraction. Chromatographic separations were carried out with an isocratic mobile phase of acetonitrile/methanol/water (10:65:25), a flow of 0.8 ml min−1, detection at 290 nm and C18 column (250 × 4.6 mm, 5 µm). The method validation parameters were determined according to Brazilian legislation. The optimization of the hibalactone ultrasound-assisted extraction was performed using Box-Behnken design and response surface methodology. The HPLC method for hibalactone quantification proved to be selective, linear, precise, accurate and robust, being useful for the analysis of hibalactone in H. umbellata subterraneous parts extracts. The optimal ultrasound-assisted extraction conditions were obtained with solid-to-liquid ratio of 1:5 g ml−1, ethanolic strength of 70% (v/v) and temperature of 65 °C. The results can provide support of the quality control and standardization of raw materials from H. umbellata.

RESUMO

Abstract Hortia oreadica Groppo, Kallunki & Pirani, Rutaceae, known as “para-tudo”, “quina”, and “quina-do-campo”, is used in traditional medicine locally to treat stomach pain and fevers. The aims of this study were: analyze the chemical composition of essential oils from leaves, flowers and fruits of H. oreadica and verify the seasonal variation of the chemical components of essential oils from leaves. The essential oils were obtained by hydrodistillation using a Clevenger type apparatus and analyzed by GC/MS. The major components found in the samples of the essential oils were the amorpha-4,7(11)-diene (29.27% – flowers, 20.26% – fruits, 27.66–37.89% – leaves), bicyclogermacrene (23.28% – flowers, 20.64% – fruits, 14.71% to 31.37% – leaves). This work represents the first study of the chemical composition of essential oils from leaves, flowers and fruits and seasonal variation in the essential oils from leaves of H. oreadica.

RESUMO

GC analysis of the dichloromethane extracts obtained from cultivated specimens of Mikania glomerata Sprengel possibilited to verify that cuttings technique led to production of kaurenoic acid and coumarin while the same results have not been observed by propagation process using in vitro techniques.

A análise realizada por CG dos extratos diclorometânicos das folhas de Mikania glomerata Sprengel mostrou que a planta propagada por estaca produziu cumarina e ácido caurenóico, enquanto que o material micropropagado acumulou apenas cumarina.

RESUMO

O objetivo deste trabalho foi avaliar a sazonalidade sobre o teor de saponinas e o isolamento e elucidação estrutural de constituinte químico (flavona) de Baccharis trimera (Less.) DC (Carqueja). O cultivo de indivíduos estaminados de B. trimera foi realizado no Campo Experimental da Universidade de Ribeirão Preto - Unaerp, em Ribeirão Preto, no período de janeiro a dezembro de 1998 e foi conduzido em três blocos, sendo que cada um deles era constituído de 48 mudas. As amostras foram colhidas após seis meses do plantio (durante o inverno), três meses após a primeira colheita (durante a primavera) e três meses após a segunda colheita (durante o verão). Após processo de secagem e moagem, as drogas foram submetidas ao ensaio para obtenção do índice de espuma. Os resultados mostraram que não há variabilidade neste índice em função da época de colheita. Parte da droga colhida no verão sofreu análise química para isolamento e elucidação estrutural de componente químico. O isolamento a partir do extrato metanólico de partes aéreas de B. trimera foi realizado através de métodos cromatográficos (CC e CLAE) e a identificação estrutural da substância isolada, através de métodos espectrométricos (UV, RMN ¹H e 13C). Foi identificada a flavona denominada 5,6-diidroxi-7,3,4-trimetoxiflavona.

The aim of this study was to evaluate the seasonal effect on the foam index and the isolation and structural identification of a chemical constituent (flavone) of Baccharis trimera. The culture staminate samples of B. trimera were realized in the experimental cultivation area of the Universidade de Ribeirão Preto - Unaerp, in Ribeirão Preto, state of São Paulo, Brazil from January to December/1998 and were conduced in three blocks, which received 48 seedlings. The samples were harvested six months after installation (during the winter), three months after the first harvest (during the spring) and three months after the second harvest (during the summer). After the drying process and comminution, an assay to obtain the foam index was performed with the plant material. The results didn't show any alteration, independently of harvest times. Part of the dried plant that had been harvested during the summer was extracted to isolate and identify structurally the chemical compound. The isolation from the methanol extracts of the aerial parts of B. trimera has been performed through chromatographic methods (CC and HPLC) and the identification through spectrometric methods (UV, ¹H and 13C NMR). A flavone was identified as 5,6-dihidroxy-7,3,4-trimetoxiflavone.

RESUMO

Synthetic metalloporphyrins, in the presence of monooxygen donors, are known to mimic the various reactions of cytochrome P450 enzymes systems in the oxidation and oxygenation of various drugs and biologically active compounds. This paper reports an HPLC-MS-MS investigation of chlorogenic acid (CGA) oxidation by iodosylbenzene using iron(III) tetraphenylporphyrin chloride as catalyst. The oxidation products have been detected by sequential MS analyses. In addition, CGA was submitted to an in vitro metabolism assay employing isolated rat liver mitochondria. The single oxidized product obtained from mitochondrial metabolism corresponds to the major product formed by the metalloporphyrin-catalyzed reaction. These results indicate that biomimetic oxidation reactions, in addition to in vitro metabolism assays employing isolated organs/organelles, could replace some in vivo metabolism studies, thus minimizing the problems related to the use of a large number of living animals in experimental research.

Assuntos

RESUMO

O estudo fitoquímico do extrato diclorometânico dos calos obtidos a partir de segmentos foliares de Mikania glomerata Sprengel resultou no isolamento dos esteróides campesterol, estigmasterol e ß-sitosterol e da cumarina, não tendo sido detectado nenhum diterpeno do tipo caurano

Assuntos