Bernd Hoffmann

Flavonolglykoside des Beifuß (Artemisia vulgaris L.), Estragon (Artemisia dracunculus L.) und Wermut (Artemisia absinthium L.)

SummaryThe following flavonol 3-O-glycosides of the leaves of mugwort (A), tarragon (B) and absinth (C) have been isolated by preparative paper and thin-layer chromatography: kaempferol 3-rhamnoglucoside in B, quercetin 3-glucoside in A and C, quercetin 3-rhamnoglucoside (rutin) in A, B and C, isorhamnetin 3-glucoside and 3-rhamnoglucoside in C and probably in A, patuletin 3-glucoside and 3-rhamnoglucoside in B and C, and spinacetin 3-glucoside and 3-rhamnoglucoside in C.ZusammenfassungAus den Blättern von Beifuß (A), Estragon (B) und Wermut (C) wurden durch präparative Papier- und Dünnschichtchromatographie folgende Flavonol-3-O-glykoside isoliert: Kämpferol-3-rhamnoglucosid in B, Quercetin-3-glucosid in A, C, Quercetin-3-rhamnoglucosid (Rotin) in A, B, C, Isorhamnetin-3-glucosid und -3-rhamnoglucosid in C und wahrscheinlich auch in A, Patuletin-3-glucosid und -3-rhamnoglucosid in B, C und Spinacetin-3-glucosid und-3-rhamnoglucosid in C.

Natürliche Vorkommen von Progesteron in handelsüblichen Milchprodukten

ZusammenfassungDie Konzentration von Progesteron in handelsüblichen Milchprodukten wurde mit einem radioimmunologischen Verfahren bestimmt. Die gemessenen Werte reichen von 1,4 ng/ml (Magermilch) bis zu ca. 300 ng/g (Butter), wobei eine enge Korrelation zwischen dem Progesterongehalt und der Fettkonzentration in den Produkten besteht. Es wird diskutiert, daß Hormone als natürliche Inhaltsstoffe in Lebensmitteln aufgrund methodisch-analytischer Fort schritte in Mikroquantitäten erfaßbar geworden sind, denen bisher keine biologische Bedeutung zuerkannt werden kann; diese Tatsache sollte aber zu einer Revision von Begriffen wie „hormon frei” im Sinne von „Nulltoleranzen” Veranlassung geben.SummaryBy means of radioimmunoassay the concentrations of progesterone in commercial milk products were determined. The values range from 1.4 ng/ml (skim milk) to 300 ng/g (butter). The results show a close correlation between progesterone and fat contents in milk products. It is discussed that - due to recent progress in analytical methods - hormones in their natural occurence in food are now measureable in micro-quantities which were not yet considered to be of biological importance; these findings should provoke a revision of terms like „free of hormones” in the sense of „zero tolerances”.

Residues and Clearance of Anabolic Agents in Veal Calves

The obvious benefit from the use of anabolic agents for fattening veal calves has forced us to provide residue data for risk evaluation and to establish analytical methods to control illegal treatments. The requirement of extraction and purification procedures being applied in connection with radioimmunological and/or thin-layer-chromatographic determinations are presented. In model experiments, with the disqualified compound diethylstilbestrol (DES), it could be demonstrated that residues and clearance rate depend mainly on the route of administration, the formulation of the preparation, the type of vehicle and the time after application. After intramuscular injection of DES dissolved in oil a quick clearance within one to four weeks has been observed, whereas the application of a crystalline DES-suspension still gave measurable values after three to four months. Due to easy sampling and the relatively high DES concentration, faeces should be used preferentially for monitoring purposes. Properly used and dosed trenbolone acetate pellets (as licensed in some countries already) gave TBOH concentrations -so far extractable- below 1 nanogram/g in edible tissues and in the nanogram range in excreta during a normal fattening period. Exogenously administered physiological steroidal oestrogens showed different clearance rates depending on the site of implantation. The oestrogen levels in the muscle of untreated as well as treated calves were in the low picogram range while those in liver and kidney were in the higher picogram range. Levels of these steroids of untreated and treated male and female calves overlapped in some cases. The concentrations of physiological steroids found in commonly consumed edible tissues from adult cattle were very often higher than those of properly treated veal calves.