Abstract (eng)
The aim of this thesis was the phytochemical investigation of the Mongolian medicinal plant Dianthus versicolor accompanied by the testing for its activity on the bile flow. It is used in traditional medicine for various indications, among them for the treatment of liver and gastrointestinal disorders.
An aqueous extract, prepared according to the traditional way of intake, was tested in the model of the isolated perfused rat liver in order to examine its influence on the bile flow. Different concentrations led to an increase of the bile flow showing a slight dose dependency. The extract was subsequently fractionated by solid phase extraction and one of the fractions, enriched in flavonoids showed an influence on the bile flow. This effect was comparable to the positive control cynarin, which is known for its cholerectic activity. Furthermore, the extract was examined on isolated organ preparations from the uterus, aorta, heart, arteria pulmonalis and terminal ileum and showed a uterus-constringing activity.
Further fractionation of the enriched flavonoid fraction by centrifugal partition chromatography or column chromatography and purification by semipreparative HPLC led to the isolation of nine flavonoid-C- and O-glycosides. Their structures were established on the basis of extensive spectroscopic and spectrometric investigations including LC-DAD, LC-MSn, LC-HR-ESI-MS, 1D and 2D NMR, and by GC-MS analysis after hydrolysis. Seven of the isolated structures are new, and have not been described for D. versicolor so far.
For the quantification of the flavonoids different HPLC-DAD methods were established and validated using external or internal standards. As alternative a quite simple UV-spectrophotometric method was developed. It based on a monograph from the European Pharmacopoeia and was slightly modified, showing comparable data to those obtained from HPLC-DAD analysis.
The qualitative and quantitative analyses allowed a detailed phytochemical characterization of the flavonoids contained in the aqueous extract of this plant and led to the isolation and structural elucidation of new compounds.