An approach of ionic liquids/lithium salts based microwave irradiation pretreatment followed by ultrasound-microwave synergistic extraction for two coumarins preparation from Cortex fraxini.

Ionic liquids/lithium salts solvent system was successfully introduced into the separation technique for the preparation of two coumarins (aesculin and aesculetin) from Cortex fraxini. Ionic liquids/lithium salts based microwave irradiation pretreatment followed by ultrasound-microwave synergy extraction (ILSMP-UMSE) procedure was developed and optimized for the sufficient extraction of these two analytes. Several variables which can potentially influence the extraction yields, including pretreatment time and temperature, [C4mim]Br concentration, LiAc content, ultrasound-microwave synergy extraction (UMSE) time, liquid-solid ratio, and UMSE power were optimized by Plackett-Burman design. Among seven variables, UMSE time, liquid-solid ratio, and UMSE power were the statistically significant variables and these three factors were further optimized by Box-Behnken design to predict optimal extraction conditions and find out operability ranges with maximum extraction yields. Under optimum operating conditions, ILSMP-UMSE showed higher extraction yields of two target compounds than those obtained by reference extraction solvents. Method validation studies also evidenced that ILSMP-UMSE is credible for the preparation of two coumarins from Cortex fraxini. This study is indicative of the proposed procedure that has huge application prospects for the preparation of natural products from plant materials.

Purification of coumarin compounds from Cortex fraxinus by adsorption chromatography.

In this paper, a chromatographic method for isolation and purification of coumarin compounds from Cortex fraxinus was established by using Superose 12 as the separation media for the first time. The conditions for separation were optimized. Four kinds of coumarin compounds including aesuletin, aesculin, fraxetin and fraxin were obtained. The purity of these compounds were 98.5, 99.1, 97.9 and 97.3%, respectively, which were determined by HPLC area normalization method. The chemical structures of the separated compounds were identified according to (1)H and (13)C nuclear magnetic resonance data. The retention behavior of the separated coumarin compounds on Superose 12 was also discussed. The retention is based on a mixture of hydrogen bonding and hydrophobic interactions between the coumarin compounds and the residues of the cross-linking reagents used in the manufacturing process of Superose 12. The results of this paper indicate that Superose 12 is not only suitable for size-exclusion chromatography of proteins and other biological macromolecules but also for low-molecular-weight natural products.

Regulation of cytochrome P450 mRNA expression in primary porcine hepatocytes by selected secondary plant metabolites from chicory (Cichorium intybus L.).

Chicory (Cichorium intybus) has been shown to induce enzymes of pharmacokinetic relevance (cytochrome P450; CYP). The aim of this study was to investigate the effects of selected secondary plant metabolites with a global extract of chicory root, on the expression of hepatic CYP mRNA (1A2, 2A19, 2C33, 2D25, 2E1 and 3A29), using primary porcine hepatocytes. Of the tested secondary plant metabolites, artemisinin, scoparone, lactucin and esculetin all induced increased expression of specific CYPs, while esculin showed no effect. In contrast, a global extract of chicory root decreased the expression of CYP1A2, 2C33, 2D25 and 3A29 at high concentrations. The results suggest that purified secondary metabolites from chicory affect CYP expression and thereby might affect detoxification in general, and that global extracts of plants can have effects different from individual components.

Spirostanol saponins and esculin from Rusci rhizoma reduce the thrombin-induced hyperpermeability of endothelial cells.

Rusci rhizoma extracts are traditionally used against chronic venous disorders (CVD). To determine the effect of its secondary plant metabolites on the endothelium, phenolic compounds and saponins from Butcher's broom were isolated from a methanolic extract, and their activity on the thrombin-induced hyperpermeability of human microvascular endothelial cells (HMEC-1) was investigated in vitro. In addition to the six known spirostanol saponins deglucoruscin (5), 22-O-methyl-deglucoruscoside (6), deglucoruscoside (7), ruscin (8), ruscogenin-1-O-(α-l-rhamnopyranosyl-(1→2)-ß-d-galactopyranoside (9) and 1-O-sulpho-ruscogenin (10), three new spirostanol derivatives were isolated and identified: 3'-O-acetyl-4'-O-sulphodeglucoruscin (1), 4'-O-(2-hydroxy-3-methylpentanoyl)-deglucoruscin (2) and 4'-O-acetyl-deglucoruscin (3). Furthermore, the coumarin esculin (4), which is also prominently present in other medicinal plants used in the treatment of CVD, was isolated for the first time from Rusci rhizoma. Five of the isolated steroid derivatives (2, 5, 8, 9 and 10) and esculin (4) were tested for their ability to reduce the thrombin-induced hyperpermeability of endothelial cells in vitro, and the results were compared to those of the aglycone neoruscogenin (11). The latter compound showed a slight but concentration-dependent reduction in hyperpermeability to 71.8% at 100µM. The highest activities were observed for the spirostanol saponins 5 and 8 and for esculin (4) at 10µM, and these compounds resulted in a reduction of the thrombin-induced hyperpermeability to 41.9%, 42.6% and 53.3%, respectively. For 2, 5 and 8, the highest concentration tested (100µM) resulted in a drastic increase of the thrombin effect. The effect of esculin observed at a concentration of 10µM was diminished at 100µM. These in vitro data provide insight into the pharmacological mechanism by which the genuine spirostanol saponins and esculin can contribute to the efficacy of Butcher's broom against chronic venous disorders.

In vitro propagation of Cichorium intybus L. and quantification of enhanced secondary metabolite (esculin).

In this report, rapid and effective shoot as well as root regeneration system through direct multiplication was successfully developed for Cichorium intybus L. Furthermore, the effect of exogenous growth regulators (TDZ and IAA) at different concentrations on the regulation process of the plant was also studied. Enhanced production of esculin in developed C. intybus L. was evaluated using leaf extract. Only on the expense of 20 days, regeneration was seen and very low dose of TDZ was seen to be more effective. When 0.02 mg/L of TDZ was combined with 1.5mg/L of IAA, nearly 100% of explants produced shoots with the highest number of regenerated shoots (85.37). With further increase in concentration (≥ 0.05 mg/L), the number of shoots per explants get decreased. A lower NAA to IBA ratio (1.0mg/L of IBA and 0.5mg/L of NAA) seemed to be more effective for root generation and considered to be the most effective combination among the tried groups. IBA was more effective in root development than NAA, but both were comparatively effective. On quantitative analysis by RP-HPLC, the 76.23% of Esculin were found in leaf extract of the in vitro developed C. intybus L. This amount was 26.77% higher than normal grown plants.

Constituents and secondary metabolite natural products in fresh and deteriorated cassava roots.

A phytochemical analysis of cassava (Manihot esculenta Crantz) fresh roots and roots suffering from post-harvest physiological deterioration (PPD) has been carried out. The first isolation and identification of galactosyl diacylglycerides from fresh cassava roots is reported, as well as beta-carotene, linamarin, and beta-sitosterol glucopyranoside. The hydroxycoumarin scopoletin and its glucoside scopolin were identified from cassava roots during PPD, as well as trace quantities of esculetin and its glucoside esculin. There is no isoscopoletin in cassava roots during PPD.

Non-aqueous capillary electrophoresis for separation and simultaneous determination of fraxin, esculin and esculetin in Cortex fraxini and its medicinal preparations.

A non-aqueous capillary electrophoresis method has been developed for the separation and simultaneous determination of fraxin, esculin and esculetin in Cortex fraxini and its preparation for the first time. Optimum separation of the analytes was obtained on a 47 cm x 75 microm i.d. fused-silica capillary using a non-aqueous buffer system of 60 mM sodium cholate, 20 mM ammonium acetate, 20% acetonitrile and 3% acetic acid at 20 kV and 292 K, respectively. The relative standard deviations (RSDs) of the migration times and the peak heights of the three analytes were in the range of 0.23-0.28 and 2.12-2.60%, respectively. Detection limits of fraxin, esculin and esculetin were 0.1557, 0.4073 and 0.5382 microg/mL, respectively. In the tested concentration range, good linear relationships (correlation coefficients 0.9995 for fraxin, 0.9999 for esculin and 0.9992 for esculetin) between peak heights and concentrations of the analytes were observed. This method has been successfully applied to simultaneous determination of the three bioactive components with the recoveries from 90.2 to 109.2% in the five samples.

[Chemical constituents from Alyxia sinensis (II)].

OBJECTIVE: To demonstrate the chemical constituents of Alyxia sinensis. METHOD: The constituents were isolated by column chromatography and identified by advanced physical and spectral analysis. RESULT: Eight compounds have been isolated and elucidated as bauereny acetate(18), scopletin(19), liriodendrin(20), pinoresinol-di-O-beta-D-glucopyranoside(21), daucosterol(22), flaxetin(23), esculin(24), aseculin(25). CONCLUSION: These compounds were found from the plant for the first time, and compound 20,21,23-25 were found from Alyxiae genis for the first time, and compound 18 is firstly been isolated from natural source.

Simultaneous isolation of Rutin and Esculin from plant material and drugs using solid-phase extraction.

Simultaneous isolation of Rutin and Esculin from pharmaceutical materials (plant--Flos hippocastani and drugs--Venescin, Venacorn) using solid-phase extraction (SPE) have been made. For this investigation the Bakerbond SPE columns with different unpolar and polar chemically bonded phases were used. On the basis of isolation investigation the influence of SPE packing materials on the selectivity change and recovery of both extracted substances were studied.

Utilización de la esculina en la identificación de bacterias / Use of esculin for identification of bacteria

La prueba bioquímica de hidrólisis de la esculina es usada en bacteriología principalmente en la identificación de Streptococcus grupo D. En este estudio con 554 cepas bacterianas el 98%de Klebsiella pneumoniae y 92,3%de Serratia sp. dieron resultados positivos. Presentaron bajos porcentajes Enterobacter sp. , Salmonella sp. y Aeromonas hydrophila y resultados negativos Escherichia coli Pseudomonas aeruginosa, Staphylococcus sp., Proteus sp. y Shigella sp. consideramos que en nuestro medio esta prueba tiene valor en la clasificación de Klebsiella pneumoniae, Streptococcus sp. gama hemolíticos y serratia sp.