CZE Determination of Flavonoids in Halenia elliptica

Chromone derivatives from Halenia elliptica and their anti-HBV activities

Nine water-soluble chromone derivatives, including chromone-2-carboxylic acids, 2-methylchromones and their structural hybrids, were isolated from aerial tissues of Halenia elliptica (Gentianaceae), six of which were previously unknown. Their structures were elucidated by comprehensive mass, 1D and 2D NMR spectroscopic analyses and chemical derivatization. Two unstable structural hybrids of chromone-2-carboxylic acids and 2-methylchromones, viz. 3-acetyl-8-hydroxy-4H-1-benzopyran-4-one-2-carboxylic acid (halenic acid C) and 2-(8-hydroxy-2-methyl-4H-1-benzopyran-4-one-3-yl)-2-oxoacetic acid (halenichromone A), were isomers and were interconvertible. The proposed mechanism of their acid-catalyzed isomerization in aqueous solvent is described. In addition, 2-methylchromones, 8-hydroxy-2-methyl-4H-1-benzopyran-4-one, and 8-methoxy-2-methyl-4H-1-benzopyran-4-one, were found to exhibit a strong inhibitory effect towards hepatitis B virus (HBV) in vitro without showing significant cytotoxicity.

A new xanthone from Halenia elliptica D. Don

A new xanthone, 1,5-dihydroxy-2,3,4-trimethoxyxanthone (1), together with 15 known compounds (2-16), was isolated from an ethanolic extract of Halenia elliptica D. Don. Their structures were elucidated by spectroscopic methods. Among the known compounds, the (13)C NMR spectroscopic data of 2,3,4,5-tetramethoxyxanthone-1-O-gentiobioside (2) were reported for the first time.

Extracts of Halenia elliptica exhibit antioxidant properties in vitro and in vivo

The antioxidant properties of different extracts of Halenia elliptica was investigated by employing various established in vitro systems. The results showed that various extracts possessed strong antioxidant activity in vitro, and the 70% methanol extract (ME) had the strongest antioxidant activity. Based on our in vitro results, ME was used for investigating the antioxidant properties of H. ellipticain vivo. The liver and kidney of CCl(4)-intoxicated animals exhibited a significant decrease in superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH) levels. Additionally, these organs exhibited a significant increase in the level of malondialdehyde (MDA). These changes were significantly reversed, in a dose-dependent manner, after treatment with ME and the standard treatment Vitamin E. Thus, it may be concluded that the ME possesses potent antioxidant properties, and might be valuable natural source of antioxidants that could be applicable to both the medical and food industries.

Hepatoprotective and antioxidant effects of the methanolic extract from Halenia elliptica

AIMS OF STUDY

Halenia elliptica, a medicinal herb of Tibetan origin, was commonly used in folk medicine to treat hepatitis. The aim of the present study is to evaluate the hepatoprotective and antioxidant activity of Halenia elliptica against experimentally induced liver injury.

MATERIALS AND METHODS

The antioxidant property of methanolic extract (ME) of Halenia elliptica was investigated by employing various established in vitro systems. The ME of Halenia elliptica was studied here for its hepatoprotective effects against CCl(4)-induced liver toxicity in rats. Activity was measured by monitoring the levels of alanine aminotransferase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP), and total bilirubin.

RESULTS

The ME possessed strong antioxidant activity in vitro. The results of CCl(4)-induced liver toxicity experiment showed that rats treated with the ME of Halenia elliptica (100 mg/kg and 200 mg/kg), and also the standard treatment, silymarin (50 mg/kg), showed a significant decrease in ALT, AST, ALP, and total bilirubin levels, which were all elevated in the CCl(4) group (p<0.01). The results observed after administration of 100 mg/kg ME were comparable to those of silymarin at 50 mg/kg (p>0.05). The ME did not show any mortality at doses up to 2000 g/kg body weight.

CONCLUSION

These results seem to support the traditional use of Halenia elliptica in pathologies involving hepatotoxicity, and the possible mechanism of this activity may be due to strong free radical-scavenging and antioxidant activities of ME.

Simultaneous determination of flavonoids in Ixeridium gracile by micellar electrokinetic chromatography

A micellar electrokinetic chromatography (MEKC) method has been developed for the quantitative analysis of five flavonoids: luteolin 7-O-glucoside (LG), 2',4'-dihydroxy-dihydrochalcone (DD), 2',4'-dihydroxy-chalcone (DC), 7-hydroxy-flavanone (HF) and quercetin 3-O-galactoside (QG) in Ixeridium gracile with UV detection at 275 nm. The applied voltage was 25 kV and the capillary temperature was kept constant at 25 degrees C. The effects of buffer pH, the concentration of electrolyte and organic modifier on migration behavior were studied. Optimum separation condition was achieved with 15 mM borate, 30 mM sodium dodecyl sulfate (SDS) and 10% (v/v) ethanol at pH 10.5. Regression equations showed good linear relationships (correlation coefficients: 0.9984, 0.9991, 0.9994, 0.9995 and 0.9997) between the peak area of each compound and their concentrations. The relative standard deviations (R.S.D.) of the migration time and peak area were less 1.67 and 3.53% (intra-day), and 1.82 and 3.73% (inter-day), respectively, under the optimum separation conditions. The contents of the five active compounds in I. gracile were determined with satisfactory repeatability and recovery.

Analysis of selected constituents in methanolic extracts ofHypericum perforatum collected in different localities by capillary ITP-CZE

The on-line combination of CZE with capillary ITP (ITP-CZE) was used for the separation and quantification of selected flavonoids and phenolic acids in Hypericum perforatum leaves and flowers collected in six different localities in Slovakia. The leading electrolyte in the ITP preseparation step was 10 mM HCl with Tris as counterion (pH* 7.2). The terminating electrolyte was 50 mM boric acid of pH* 8.2 (adjusted with barium hydroxide). The BGE in the electrophoretic step contained 25 mM beta-hydroxy-4-morpholinopropanesulfonic acid (MOPSO), 50 mM Tris, 65 mM boric acid, pH* 8.3. The content of methanol in all electrolytes was 20% v/v. The total time of the analysis (including the preseparation step) was approximately 35 min. The rectilinear calibration ranges were between 0.125 and 5.0 microg/mL with kaempferol as internal standard. The correlation coefficients ranged between 0.9912 (for quercitrin and chlorogenic acid) and 0.9988 (for isoquercitrin). The RSD values are between 0.86 and 7.78% (n = 6) when determining rutin and quercetin (4 microg/mL). The optimized method was employed for the assay of flavonoids in medicinal plant extract of different collections of Hypericum perforatum haulm. The variability of the content of the active components depending on the place of collection was confirmed.