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Equisetum giganteum L., commonly called "giant horsetail", is an endemic species of Latin America. Its aerial parts have been widely used in ethnomedicine as a diuretic and in herbal medicine and food supplements as a raw material. The phenolic composition of E. giganteum stems was studied by liquid chromatography coupled to diode array detection (LC-DAD) and liquid chromatography coupled to electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS), which identified caffeic acid derivatives, flavonoids and styrylpyrones. The most abundant glycosilated flavonoids in this sample were kaempferol derivatives. Other rare phenolic components, namely, quercetin-3-O-(caffeoyl)-glucoside and 3-hydroxyhispidin-3,4'-di-O-glucoside, were reported for first time in the Equisetum genus. An LC-UV method for the simultaneous quantification of flavonoid aglycones in E. giganteum obtained after hydrolysis was developed and validated. The method exhibited excellent linearity for all analytes, with regression coefficients above 0.998, LOD ≥ 0.043µg mL(-1), LOQ ≥ 0.158 µg mL(-1) and recovery rates of 96.89-103.33% and 98.22-102.49% for quercetin and kaempferol, respectively. The relative standard deviation for the intra- and inter-day precision was ≤ 3.75%. The hydrolysis process was optimized by central composite rotational design and response surface analysis. The second-order response models for the aglycones contents were as follows: quercetin (µg g(-1))=24.8102+55.2823 × HCl+0.776997 × Time-7.23852 × HCl(2)-7.46528E-04 × Time(2)-0.229167 × HCl × Time; kaempferol (µg g(-1))=-9.66755+974.822 × HCl+11.8059 × Time-130.612 × HCl(2)-0.0125694×Time(2) -3.22917 × HCl × Time, with estimated optimal conditions of 1.18 M HCl and 205 min of hydrolysis. The results obtained with these new methods were compared to those from a spectrophotometric assay used to determine the total flavonoids in the Equisetum arvense monograph (Horsetail, British Pharmacopoeia 2011). For all four species analyzed (E. giganteum, E. arvense, E. hyemale and E. bogotense), the calculated aglycone content was higher using the optimized hydrolysis conditions. Additionally, the LC method was more appropriate and specific for quantitative analysis.

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Baccharis trimera commonly named 'carqueja', is wide-spread in South America and are used as raw material for herbal medicines. A reversed-phase liquid chromatography (RP-LC) method coupled to diode array detector was developed for the analysis of caffeoylquinic acids (CQAs), the main compounds responsible for its digestive activity. The identity of the quinic acids was established by mass spectrometry and were them: 5-O-[E]-caffeoylquinic acid, 3,4-O-[E]-dicaffeoylquinic acid, 3,5-O-[E]-dicaffeoylquinic acid, 4,5-O-[E]-dicaffeoylquinic acid and a tricaffeoylquinic acid. The RP-LC method for the quantitation of the caffeoylquinic acids was validated according to ICH guidelines, based on the following parameters: linearity, selectivity, robustness, limits of detection and quantification, precision and recovery. Hydroalcoholic extracts were prepared by the maceration of the plant material with ethanol:water 1:1 (v/v) in a 0.1:25 g mL(-1) plant:solvent ratio in a water bath at 40°C. Validation data indicated that the HPLC method proposed is suitable for the analysis of caffeoylquinic acids in B. trimera raw material. The results of the LOD and LOQ analyses for the 5-CQA were 4.1 µg mL(-1) and 12.5 µg mL(-1), respectively, 1.3 µg mL(-1), 3.9 µg mL(-1) for 4,5-diCQA and 1.7 µg mL(-1), 5.1 µg mL(-1) for triCQA. The levels of total CQAs ranged from 2.1 to 4.0 g% (w/w). The influence of season harvest and site collection was also evaluated and variations were observed in the results and can be related to phonologic phase, different locations, seasons and soil. Long term and photostability of plant material were carried out and was observed a stable behavior during the time of the experiments.

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The anti-inflammatory activity of the petroleum ether, dichloromethane and methanol extracts from Heterotheca subaxillaris var. latifolia were assayed using 12-O-tetradecanoyl phorbol acetate (TPA) induced ear edema test in mice and carrageenan-induced paw edema test in rats. The dichloromethane extract showed a significant anti-inflammatory activity (91 percent of inhibition) in TPA-induced ear edema test (topical administration at 1 mg/ear). No effects were seen on carragenan-induced edema. Bio-guided fractionation deal to the isolation of the major flavonoids santin, pectolinaringenin, 3,6-dimethoxy-5,7,4'-trihydroxyflavone and hispidulin present in the active fractions.

A atividade antiinflamatória de extratos éter petróleo, diclorometânico e metanólico de Heterotheca subaxillaris var. latifolia, foi testada pelo método de edema induzido pelo 12-O-tetradecanoil phorbol acetato (TPA) na orelha do camundongos e pelo método do edema de pata induzido por carragenina em ratos. O extrato diclorometânico mostrou atividade antiinflamatória significativa (91 por cento inibição) no edema de orelha induzido por TPA (administração tópica de 1 mg/orelha). Não houve efeitos significativos no teste do edema induzido pela carragenina. O fracionamento bioguiado das frações ativas levou ao isolamento dos flavonoides majoritários santina, pectolinaringenina, 3,6-dimetoxi-5, 7,4 '-trihidroxiflavona e hispidulina.

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The presumption that some coumarins might be lead compounds in the search for new differentiation agents against leukemia is based on the fact that natural coumarins, 5-(3-methyl-2-butenyloxy)-6,7-methylenedioxycoumarin (C-2) and 5-methoxy-6,7-methylenedioxycoumarin (C-1) inhibit proliferation and induce differentiation in U-937 cells [Riveiro, M. E.; Shayo, C.; Monczor, F.; Fernandez, N.; Baldi, A.; De Kimpe, N.; Rossi, J.; Debenedetti, S.; Davio, C. Cancer Lett.2004, 210, 179-188]. These promising findings prompted us to investigate the anti-leukemia activity of a broader range of related polyoxygenated coumarins. Twenty related natural or synthetically prepared coumarins, including a range of 5-substituted ayapin derivatives which have become easy accessible via newly developed synthesis methods, were evaluated, where treatments with 5-(2,3-dihydroxy-3-methylbutoxy)-6,7-methylenedioxycoumarin (D-3) and 5-(2-hydroxy-3-methoxy-3-methylbutoxy)-6,7-methylenedioxycoumarin (D-2) were able to inhibit the cell growth and induce the differentiation of U-937 cells after 48 h treatment. These results provide insight into the correlation between some structural properties of polyoxygenated coumarins and their in vitro leukemic differentiation activity.

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The present study focused on the effect of a series of extracts and two 5,6,7-trioxygenated coumarins isolated from Pterocaulon polystachyum on the proliferation and differentiation of human promonocytic U-937 cells. The petroleum ether extract was the only extract that significantly reduced cell proliferation and induced cell differentiation. Treatment with pure 5-methoxy-6,7-methylenedioxycoumarin (C1) and 5-(3-methyl-2-butenyloxy)-6,7-methylenedioxycoumarin (C2), present in the petroleum ether extract, showed a time and concentration-dependent inhibition on cell proliferation. In addition, the coumarin derivatives were also able to induce CD88 functionality and NBT reduction, markers of monocytic cell differentiation. These results suggest that C1 and C2 might have a potential therapeutic role in the management of leukemia.

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Dichloromethane, methanol and aqueous extracts of the aerial parts of Terminalia australis were evaluated for their antifungal activity. The methanol and aqueous extracts were found to be effective against the tested Aspergillus and Candida strains.

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