Christa Kletter
University of Vienna
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Carbohydrate Research | 2011
Astrid Obmann; Ingrid Werner; Armin Presser; Martin Zehl; Zita Swoboda; Sodnomtseren Purevsuren; Samdan Narantuya; Christa Kletter; Sabine Glasl
Eighteen flavonoids were identified from an aqueous extract of the aerial parts of Dianthus versicolor, a plant used in traditional Mongolian medicine against liver diseases. The flavonoid C- and O-glycosides isoorientin-7-O-rutinoside, isoorientin-7-O-rhamnosyl-galactoside, isovitexin-7-O-rutinoside, isovitexin-7-O-rhamnosyl-galactoside, isoscoparin-7-O-rutinoside, isoscoparin-7-O-rhamnosyl-galactoside, isoscoparin-7-O-galactoside, and isoorientin-7-O-galactoside were isolated and structurally elucidated. Their structures were established on the basis of extensive spectroscopic techniques including LC-UV-DAD, LC-MS(n), LC-HRMS, 1D and 2D NMR spectroscopy, and by GC-MS analysis after hydrolysis. Flavonoids with such a high glycosylation pattern are rare within the genus Dianthus. Furthermore, isovitexin-7-O-glucoside (saponarin), isovitexin-2″-O-rhamnoside, apigenin-6-glucoside (isovitexin), luteolin-7-O-glucoside, apigenin-7-O-glucoside, as well as the aglycons luteolin, apigenin, chrysoeriol, diosmetin, and acacetin were identified by TLC and LC-DAD-MS(n) in comparison to reference substances or literature data. The NMR data of seven structures have not been reported in the literature to date.
Phytochemical Analysis | 2012
Astrid Obmann; Sodnomtseren Purevsuren; Martin Zehl; Christa Kletter; Gottfried Reznicek; Samdan Narantuya; Sabine Glasl
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.
Journal of Separation Science | 2011
Astrid Obmann; Martin Zehl; Sodnomtseren Purevsuren; Samdan Narantuya; Gottfried Reznicek; Christa Kletter; Sabine Glasl
An HPLC-diode array detection (DAD) method was established in order to investigate dried aerial parts of Dianthus versicolor FISCH. (Caryophyllaceae), a plant used in traditional Mongolian medicine against liver impairment. Aqueous extracts were separated on an Aquasil(®) C(18) column with a linear gradient of acetonitrile (ACN) and water (adjusted to pH 2.8 with formic acid) as the mobile phase. LC-IT-MS facilitated the assignment of 26 flavonoids, among them a series of rare C-glycosylated as well as O-glycosylated derivatives, which are assumed to be the active principles. Quantification was performed and validated using isovitexin-7-O-glucoside (saponarin) as the external standard. The method showed good linear behaviour (r(2) ≥0.9999) over the investigated concentration range (0.007-3.5 mg/mL). The good precision of the method allowed the successful qualitative and quantitative analysis of flavonoid-glycosides in the aqueous extracts prepared from five different D. versicolor samples. Depending on the origin of the samples, the total flavonoid content was found to vary considerably from 0.41 to 3.30% in the aqueous extracts and from 0.07 to 0.57% in the crude drug. In addition, the relative composition of the various flavonoids was found to differ strongly. These results highlight the need for proper quality control for this herbal drug.
Scientia Pharmaceutica | 2010
Christa Kletter
This overview reflects the extensive changes in the health care system which had significant effects on the apothecary’s profession and education. In the 18th 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 apothecary’s 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 19th century also affected the apothecary business and led to a crisis of the profession. Furthermore, the apothecaries’ 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.
Phytochemistry | 2005
Angelika Lendl; Ingrid Werner; Sabine Glasl; Christa Kletter; Pavel Mučaji; Armin Presser; Gottfried Reznicek; Johann Jurenitsch; David W. Taylor
Planta Medica | 2004
Christa Kletter; Sabine Glasl; Armin Presser; Ingrid Werner; Gottfried Reznicek; Samdan Narantuya; Selim Cellek; Ernst Haslinger; Johann Jurenitsch
Scientia Pharmaceutica | 2008
Christa Kletter; Sabine Glasl; Theresia Thalhammer; Samdan Narantuya
Journal of Ethnopharmacology | 2010
Astrid Obmann; Damba Tsendayush; Theresia Thalhammer; Martin Zehl; Thanh Phuong Nha Vo; Sodnomtseren Purevsuren; Damdinsuren Natsagdorj; Samdan Narantuya; Christa Kletter; Sabine Glasl
Planta Medica | 2006
Sabine Glasl; Damba Tsendayush; Usukhbayar Batchimeg; Nina Holec; Esther Wurm; Christa Kletter; Disan Gunbilig; Khurelbat Daariimaa; Samdan Narantuya; Theresia Thalhammer
Planta Medica | 2007
A. Obmann; T. Radovic; Christa Kletter; Sabine Glasl