@article{TackePikiesWiesenbergeretal.1994, author = {Tacke, Reinhold and Pikies, J. and Wiesenberger, F. and Ernst, L. and Schomburg, D. and Waelbroeck, M. and Christophe, J. and Lambrecht, G. and Gross, J. and Mutschler, E.}, title = {Sila-biperiden und endo-Sila-biperiden: Synthesen, Kristallstrukturen und antimuscarinische Eigenschaften}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64303}, year = {1994}, abstract = {Starting from trichloro(vinyl)silane (Cl\(_3\)SiCH=CH\(_2\)), the musearinic antagonists sila-biperiden [rac-(SiRS,C2SR>-ao-2] and endosila- biperiden [rac-(SiRS,C2SR)-endo-2] were prepared by a seven-step synthesis. Both silanols are configurationally stableininert organic solvents but undergo slow epimerization in aqueous solution (pH 7.4, 32°C) by inversion of the configuration at the silicon atom. The relative configurations of sila-biperiden and endo-sila-biperiden were detennined by single-crystal X-ray diffraction. Both compounds form intennolecular 0-H · · · N hydrogen bonds in the crystal leading to the fonnation of centrosymmetric dimers (sila-biperiden) and infinite chains (endo-sila-biperiden), respectively. Sila-biperiden is a silicon analogue (C/Si exchange) of the antiparkinsonian drug biperiden [rac-(CRS/C2SR}-exo-1]. In functional phannacological experiments, as well as in radioligand competition studies, biperiden, sila-biperiden and endo-sila-biperiden behaved as simple competitive antagonists at muscarinic Ml-, M2-, M3- and M4-receptors. The three compounds displayed the highest affinity for Ml-receptors (pA\(_2\) values: 8.72-8.80; pK\(_i\) values: 8.8-9.1), intermediate affinity for M4- and M3-receptors, and lowest affinity for M2-receptors (pA\(_2\) values: 7.57-7.79; pK\(_i\) values: 7.7-7.8). The affinity profile (Ml >. M4 > M3 > M2) of biperiden, sila-biperiden and endo-sila-biperiden is qualitatively similar to that of the M1-selective muscarinic antagonist pirenzepine. The antimuscarinic properlies of the C/Si analogues biperiden and sila-biperiden are almost identical.}, subject = {Anorganische Chemie}, language = {en} } @article{TackePikiesLinohetal.1987, author = {Tacke, Reinhold and Pikies, J. and Linoh, H. and Rohr-Aehle, R. and G{\"o}nne, S.}, title = {Sila-Procyclidin: Eine neue Synthese sowie Untersuchungen zur peripheren und zentralen anticholinergen Wirkung}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63815}, year = {1987}, abstract = {Sila-Procyclidin (1 b) sowie dessen Derivate 2b (Sila-Tribexyphenidyl), 3b und 4b (Sila-Cycrimin) wurden - ausgehend von Cl\(_3\)SiCH\(_2\)Cl - durch eine neue, sechsstufige Synthese mit einer Gesamtausbeute von 16 (lb), t9 (2b), 8 (3b) bzw. 7\% (4b) dar· gestellt. - Vergleichende in-vivo-Untcrsuchungen (Maus, per-osApplikation) hinsichtlich der peripheren und zentralen auticholincrgen Wirkung haben gezeigt, daß die Silicium-Verbindung 1 b dem Kohlenstoff-Analogon Ia (Procyclidin) {\"u}berlegen ist.}, subject = {Anorganische Chemie}, language = {de} }