[en] The pharmacokinetics of ³H-ZIMET 98/69 after i.v. and oral administration to rats was studied. After i.v. administration of 2.5 and 10 mg/kg a biphasic exponential decay of total serum radioactivity was found, so that a two-compartment open model could be assumed. Oral administration of 10 mg/kg results in only a moderate bioavailability (25%), which further decreased after administration of higher doses. The distribution steady state between serum and tissue is reached rapidly. Elimination proceeds slowly, the serum half-life being 64-84 h. (author)

No abstract available

No abstract available

[en] The incorporation was investigated of ¹⁴C-labelled potential donors of methyl groups as e.g. methanol, formaldehyde and methionine into the macrolide antibiotic turimycin as well as in the platenolide glycosides as the shunt products of turimycin biosynthesis by Streptomyces hygroscopicus IMET 6599- R 27-158v. By contrast to ¹⁴C-methyl-D,L-methionine giving rise to equal specific labelling of both groups of secondary metabolites, the ¹⁴C-labelled methanol and formaldehyde, respectively, led to more than 30-fold higher specific labelling of the platenolide glycosides. The results suggest that, on the one hand, there is a common intermediate, the demethylplatenolide-I (DM-Pl-I), in the biosynthesis of secondary metabolites by this strain and, secondly, that there are exist alternative pathways of biological methylation of DM-Pl-I. (author)

No abstract available

[en] The substance P (SP) analogs [Lys(MSOC)³]-SP, [Tyr⁸]-SP, [Tyr⁸,Nle¹¹]-SP and [p-HPA¹]-SP have been synthesized by classical methods of peptide synthesis as well as by the liquid phase peptide synthesis (LPPS) to allow conjugation with protein in the Nα-position and radioiodination. [Tyr⁸]-SP and [p-HPA-Arg¹]-SP have been radioiodinated by the chloramine T- and the lactoperoxidase method. A complete S-oxidation of SP was observed, when the chloramine T procedure was used, but this modification does not disturb the assay. The introduction of the [¹²⁵I-pHPA-Arg¹]-SP-tracer led to considerable improvements of our SP-radioimmunoassay. (author)

No abstract available

[en] Adsorption of traces of gold, iron, zinc and mercury, labelled with ¹⁹⁵Au, ⁵⁹Fe, ⁶⁵Zn, ²⁰³Hg, was studied in dependence on time as well as on the container-material and composition of the solution. With exception of the zinc solutions in all other solutions a considerable decrease was ascertained. Acid- or silicone-treatment of the surfaces shortly cause altered adsorption properties, but cannot prevent a sorption. From the different adsorption behaviour of the investigated elements it is concluded that the different affinity and adhesive power of the ions must be refered to their different chemical and physical properties. (author)

[en] The structure of the main components of the chemical radiosensitizer MTDQ, a mixture obtained by reacting 2,2,4-trimethyl-2,3-dihydroquinoline with formaldehyde was elucidated with the aid of the NMR and mass spectroscopy. (author)

No abstract available