Formation of titanium(IV) transferrin by reaction of human serum apotransferrin with titanium complexes.

The reaction of human serum apotransferrin with titanium(IV) citrate under physiological conditions results in the formation of a specific bis-titanium(IV) transferrin adduct (Ti2Tf hereafter) with two titanium(IV) ions loaded at the iron binding sites. The same specific Ti2Tf complex is formed by reacting apotransferrin with titanium(III) chloride and exposing the sample to air. The derivative thus obtained was characterized by spectroscopic techniques, including absorption, UV difference, circular dichroism and 13C NMR spectroscopies, and shown to be stable within the pH range 5.5-9.0. Surprisingly, the reaction of apoTf with titanium(IV) nitrilotriacetate (NTA) does not lead to formation of appreciable amounts of Ti2Tf, even after long incubation times, although some weak interactions of Ti(IV)-NTA with apoTf are spectroscopically detected. Implications of the present results for a role of transferrin in the uptake, transport and delivery of soluble titanium(IV) compounds under physiological conditions are discussed.

[Synthesis of anticholinergically active N-alkylnorscopolamines and their quaternary salts with special consideration of the bronchospasmolytic (-)-N-ethylnorscopolamine methobromide (Ba 253 BR)]. / Synthese von anticholinerg wirksamen N-Alkylnorscopolaminen und deren Quartärsalzen unter besonderer Berücksichtigung des Bronchospasmolytikums (-)-N-Ethylnorscopolamin-methobromid (Ba 253 BR).

The synthesis of anticholinergic N-alkylnorscopolamines and their quaternary salts, especially the synthesis of (-)-N-ethylnorscopolamin methobromide (Ba 253 BR), is reported. (-)-N-Ethylnorscopolamine methobromide differs from the stereoisomeric (-)-N-ethylscopolammonium bromide not only by its physico-chemical, but also by its pharmacological properties. (-)-N-Ethylnorscopolamine methobromide represents an anticholinergic bronchodilator with long duration of action.