HPLC determination of flavonoid glycosides in Mongolian Dianthus versicolor Fisch. (Caryophyllaceae) compared with quantification by UV spectrophotometry

INTRODUCTION

Dianthus versicolor is used in traditional Mongolian medicine against liver impairment. Fractions enriched in flavone-di- and triglycosides were shown to enhance bile secretion. Therefore, reliable and accurate analytical methods are needed for the determination of these flavonoids in the crude drug and extracts thereof.

OBJECTIVE

To provide a validated HPLC-DAD (diode array detector) method especially developed for the separation of polar flavonoids and to compare the data obtained with those evaluated by UV spectrophotometry.

METHODOLOGY

Separations were carried out on an Aquasil® C₁₈-column (4.6 mm × 250.0 mm, 5 µm) with a linear gradient of acetonitrile and water (adjusted to pH 2.8 with trifluoroacetic acid) as mobile phase. Rutoside was employed as internal standard with linear behavior in a concentration range of 0.007-3.5 mg/mL. Accuracy was determined by spiking the crude drug with saponarin resulting in recoveries between 92% and 102%.

RESULTS

The method allows the quantification of highly polar flavonoid glycosides and the determination of their total content. For saponarin a linear response was evaluated within the range 0.007-3.5 mg/mL (R²  > 0.9999). It was proven that threefold sonication represents a time-saving, effective and cheap method for the extraction of the polar flavonoid glycosides. The contents determined by HPLC were shown to be in agreement with those obtained employing UV spectrophotometry.

CONCLUSION

The study has indicated that the newly developed HPLC method represents a powerful technique for the quality control of D. versicolor. Ultraviolet spectrophotometry may be used alternatively provided that the less polar flavonoids are removed by purification.

Extracts from the Mongolian traditional medicinal plants Dianthus versicolorFisch. and Lilium pumilum Delile stimulate bile flow in an isolated perfused rat liver model

AIM OF THE STUDY

Dianthus versicolor (Caryophyllaceae) and Lilium pumilum (Liliaceae) are two medicinal plants used in traditional Mongolian medicine to treat hepatic and gastrointestinal disorders. In this study aqueous (AE) and methanolic (ME) extracts of Dianthus versicolor and Lilium pumilum were investigated for their influence on the bile flow. The aqueous extracts of both plants were tested in absence and presence of 10 μM taurocholic acid at three different concentrations (100, 250, and 500 mg/L). The aqueous extract of Dianthus versicolor was further purified in order to locate the active principles. Two resulting fractions, one enriched in flavonoids and the other in sugars, were investigated for their influence on the bile flow in absence of taurocholic acid at 10, 20, and 40 mg/L. The aqueous extracts of both plants were analysed qualitatively by LC-MS(n) and quantitatively by UV-spectrophotometry.

MATERIALS AND METHODS

The bile flow experiments were performed in the isolated perfused rat liver. The compounds were identified by LC-DAD-MS(n) and TLC using references. The UV-spectrophotometric analysis was based on the monograph "Passiflorae herba" of the European Pharmacopoeia, and the total flavonoid contents were calculated and expressed as vitexin.

RESULTS

AE and ME of both plants increased the bile flow dose-dependently (between 9% and 30%), and no hepatotoxic effect was seen even during longer perfusions. Stimulation of bile secretion was comparable in the presence and in the absence of taurocholic acid. The flavonoid fraction of Dianthus versicolor increased the bile flow by 18% (p<0.05) at 40 mg/L, which was comparable to the positive control cynarin. The phytochemical investigations of the Dianthus versicolor AE (total flavonoid content 1.78%) revealed the presence of the isovitexin derivative saponarin. In the AE of Lilium pumilum (total flavonoid content 1.04%) the flavonoids rutoside, kaempferol-3-O-rutinoside, and isorhamnetin-3-O-rutinoside were detected.

CONCLUSIONS

The results show that choleresis under extract application is due to a stimulation of the bile-salt-independent bile flow which might be caused by the osmotic power of the extracts (hydrocholeresis). The flavonoids seem to contribute to the bile-flow-stimulating effect of Dianthus versicolor. Both plants exhibit a considerable choleretic effect that contributes to their use in traditional Mongolian medicine against gastrointestinal disorders.

Austrian pharmacy in the 18 and 19th century

This overview reflects the extensive changes in the health care system which had significant effects on the apothecaryâs profession and education. In the 18(th) century Maria Theresia assigned Gerard van Swieten to modernize the medical curriculum and to work out reforms for health care. The resulting sanitary bill released in 1770 and amended in 1773 became effective for the whole empire and influenced greatly the apothecaryâs profession. The Viennese Medical Faculty continued to be the supervisory body for the apothecaries, a situation which prolonged the conflicts between the faculty and the apothecaries. The financial and social distress prevalent in the 19(th) century also affected the apothecary business and led to a crisis of the profession. Furthermore, the apothecariesâ missing influence over the sanitary authorities delayed the release of a badly needed new apothecary bill until 1906. The introduction of a specific pharmaceutical curriculum at the university in 1853 was a great step forward to improve the pharmaceutical education. Nevertheless, the secondary school exam was not compulsory for the studies until 1920 and, therefore, the graduates were not on a par with other university graduates before that date. Women, except nuns, were not allowed to work as pharmacists until 1900.

Phytochemical and Microscopic Characterization of the Caribbean Aphrodisiac Bois Bandé: Two New Norneolignans

Acidic extraction of the stem bark and roots of Chione venosa (SW.) URBAN var. venosa, purchased in Grenada under the vernacular name Bois Bandé, led to the isolation of two new substances of the oxynorneolignan-type. Moreover, TLC- and HPLC-systems were developed in order to determine these substances in crude extracts. Analytical data are indicated for the new compounds, as well as for those substances which were published recently. In the different Caribbean islands different plant sources are used to furnish the aphrodisiac Bois Bandé. On the basis of the presented analytical systems, 14 different samples of Bois Bandé (stem bark and/or root) that were either purchased from local traders or collected at different sites in the Grenadian forest were examined. In addition, an entire macroscopic and microscopic description of the drug is given which, in combination with the phytochemical data, provides a powerful tool to assess the quality of the drug material with regard to its botanical homogeneity.

Choleretic effects of the Mongolian medicinal plant Saussurea amara in the isolated perfused rat liver

Saussurea amara is used in traditional Mongolian medicine for the treatment of hepato-biliary disorders. To determine the plant's effect on the bile-salt independent bile flow (hydrocholeresis) as a measure of liver exocrine functions, different extracts were investigated in the isolated rat liver perfusion system. The methanolic extract (3) exerted a dose-dependent increase in bile flow (16%, 37%, 53%, 61%) in concentrations of 50 mg/L, 100 mg/L, 250 mg/L and 500 mg/L. The aqueous crude extract (1) and the ethyl acetate extract (2) also showed a dose-dependent increase, whereas at the highest concentrations (1000 mg/L and 100 mg/L, respectively) a continuous decrease in bile flow could be observed. Cynaropicrin also provoked a dose-dependent increase in bile flow, but caused liver damage at the highest dose tested (20 mg/L). Apigenin 7- O-glucoside, present in extracts 2 and 3, induced a dose-dependent increase of 20%, 30% and 40% (5 mg/L, 10 mg/L, 20 mg/L) and showed a significantly higher effect than the reference substance cynarin. The total flavonoid content was determined by spectrophotometry. To quantify the absolute amount of cynaropicrin in the crude drug and in the tested extracts, an HLPC system was established with santonin as internal standard.

Phenolic and terpenoid compounds from Chione venosa (sw.) urban var. venosa (Bois Bandé)

The Caribbean island of Grenada furnishes the popular aphrodisiac drug Bois Bandé, which consists of the stem bark and the roots of Chione venosa (sw.) URBAN var. venosa (Rubiaceae), a native tree growing in the islands' rain forest. The phytochemical investigation of dichloromethane and methanolic-aqueous extracts of the bark and the roots yielded three acetophenone derivatives described for the first time in plants - ortho-hydroxy-acetophenone-azine (1), acetophenone-2-O-[beta-D-apiofuranosyl-(1''-->6')-O-beta-D-glucopyranoside] (2) and acetophenone-2-O-beta-D-glucopyranoside (3) - along with five known compounds, alpha-morroniside (4), sweroside (5), diderroside (6), daucosterol (7) and beta-sitosterol (8). Their structures were elucidated by 1D and 2D NMR analysis, UV-Vis and ESI-MS.

Morphological, chemical and functional analysis of catuaba preparations

Fourteen commercial samples of the popular Brazilian aphrodisiac Catuaba specified as bark drugs of Anemopaegma, Erythroxylum and Trichilia species were examined for identity and purity. Only a minority of the examined Catuaba samples contained the crude drugs claimed on the labels. More than half of the products were adulterated with different crude drugs. The majority of the samples contained a bark originating from Trichilia catigua. The TLC fingerprints confirmed the heterogeneity, in 50% of the samples tropane alkaloids of various concentrations were detected. TLC and HPLC methods for separation and identification of the tropane alkaloids were developed and their analytical data (RF values, retention times, ESI-MS) given. The structure elucidation of the two main alkaloids, catuabine D and its hydroxymethyl derivative, is presented. The 1H- and 13C-NMR assignments of these alkaloids are discussed with regard to literature data. Neither aqueous nor methanolic extracts of the Trichilia catigua reference material nor alkaloid-enriched fractions of commercial samples showed any effect on the rabbit corpus cavernosum in an in vitro test.