@article{TackeStreckerLambrechtetal.1983,
  author    = {Tacke, Reinhold and Strecker, M. and Lambrecht, G. and Moser, U. and Mutschler, E.},
  title     = {(2-Aminoethyl)-cycloalkylphenylsilanole: Bioisosterer C/Si-Austausch bei Parasympatholytika vom Typ des Trihexyphenidyls, Cycrimins und Procyclidins},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63741},
  year      = {1983},
  abstract  = {Die Synthese der (2-Aminoethyl)cycloalkylphenylsilanole Sb (Sila-Trihexyphenidyl), 6b (SilaCycrimin), 7 b (Sila-Procyclidin) und Sb wird beschrieben. Sb- Sb wurden - ausgehend von Cl\(_2\)(C\(_6\)H\(_5\))SiCH = CH\(_2\) (9) - durch eine f{\"u}nfstufige Reaktionsfolge mit einer Gesamtausbeute von 32- 40\% erhalten. Am isolierten Ileum des Meerschweinchens wurden die C/Si-Paare Sa, b- 8a, b vergleichend auf ihre antimuskarinische Aktivit{\"a}t gepr{\"u}ft. Die durch die Sila-Substilution von Sa-8a erreichte Zunahme der Affinit{\"a}t zum Muskarinrezeptor ist deutlich weniger ausgepr{\"a}gt als bei den strukturverwandten C/Si-Paaren I a, b- 4a, b.},
  subject      = {Anorganische Chemie},
  language  = {de}
}
@article{TackeStreckerLambrechtetal.1984,
  author    = {Tacke, Reinhold and Strecker, M. and Lambrecht, G. and Moser, U. and Mutschler, E.},
  title     = {Bioisosterer C/Si-Austausch bei Parasympatholytika vom Typ des Pridinols},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63766},
  year      = {1984},
  abstract  = {Die Synthese der (2·Aminoethyl)diphenylsilanole 3b und 4b wird beschrieben. Die parasympatholytischen Eigenschaften der CISi-Paare la/lb-4a/4b wurden am isolierten Ileum des Meerschweinchens untersucht. In allen F{\"a}llen f{\"u}hrt der C/Si-Austausch zu einer Zunahme der Affinit{\"a}t zum Muskarin-Rezeptor.},
  subject      = {Anorganische Chemie},
  language  = {de}
}
@article{SheldrickLinohTackeetal.1985,
  author    = {Sheldrick, W. S. and Linoh, H. and Tacke, Reinhold and Lambrecht, G. and Moser, U. and Mutschler, E.},
  title     = {Crystal and molecular structures of the (R)-enantiomer and the racemate of the antimuscarinic agent (cyclohexyl)phenyl[2-(pyrrolidin-1-yl)ethyl]silanol (sila-procyclidine)},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63776},
  year      = {1985},
  abstract  = {The crystal structures of the (R)-enantiomer (2b) and the racemate (1 b) of (cyclohexyl)phenyl[2- (pyrrolidin-1-yl)ethyl]silanol (sila--procyclidine) have been determined by X -ray structural analysis. The absolute configuration of (2b) was established. (2b) crystallizes in the orthorhombic space group P2\(_1\)2\(_1\)2\(_1\), with a = 15.221 (1 ), b = 17.967(1 ), c = 6.463(1) A, and Z = 4. (1 b) crystallizes in the monoclinic space group P2\(_1\)/c, with a = 6.441 (1 ), b = 17.1 82(7), c = 16.707(4) A, ß = 1 03.86(2r, and Z = 4. The structures were refined to respective R factors of 0.044 and 0.058. The molecular conformation of sila-procyclidine is identical in the two different structures. lntermolecular 0-H • • • N hydrogen bonding is observed in both crystallattices.ln (1 b) (R)- and (S)-configurated molecules form centrosymmetric dimers, in (2b) the (R)-configurated molecules are linked into infinite chains parallel to the c axis. The (R)-configurated sila--procyclidine (2b) has higher affinity for ileal and atrial muscarinic receptors of the guinea pig than the (S)-configurated enantiomer (3b).},
  subject      = {Anorganische Chemie},
  language  = {en}
}
@article{FeifelRodriguesdeMirandaStrohmannetal.1991,
  author    = {Feifel, R. and Rodrigues de Miranda, J. F. and Strohmann, C. and Tacke, Reinhold and Aasen, A. J. and Mutschler, E. and Lambrecht, G.},
  title     = {Selective labelling of muscarinic M\(_1\) receptors in calf superior cervical ganglia by [\(^3\)H](\(\pm\))-telenzepine},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64082},
  year      = {1991},
  abstract  = {A method was developed to detennine the affinities of antimuscarinic drugs at M\(_1\) receptors. [\(^3\)H](±)-Telenzepine served as radioligand in crude preparations of calf superior cervical ganglia and showed high affinity for a single receptor population. consisting of M1 receptors (K\(_D\) = 1.12 nM). Kinetic experiments showed monophasic association (k\(_1\) =0.017 min\(^{-1}\) nM\(^{-1}\) ) and dissociation (k\(_1\) = 0.017 min\(^{-1}\) ) kinetics, the half-life of dissociation being 41 min at 37°C. The kinetie K\(_D\) value amounted to 1.00 nM. M\(_1\) affinities for pirenzepine, methoctramine. hexahydro-sila-difenidol and p-fluoro-hexahydro-sila-difenidol detennined in competition experiments were similar to those found in functional studies with MI receptors in rabbit isolated vas deferens. The binding assay was used to deterriline the affinities of the (R) and (S) enantiomers of tertiary (trihexyphenidyl, hexahydro-difenidol. hexbutinol, p-fluoro-hexbutinol) and quatemary musearlnie antagonists (trihexyphenidyl methiodide. hexbutinol methiodide). Comparison of results obtained with the rabbit vas deferens suggested that the ionic environment may influence the affinities.},
  subject      = {Anorganische Chemie},
  language  = {en}
}
@article{WaelbroeckCamusTastenoyetal.1992,
  author    = {Waelbroeck, M. and Camus, J. and Tastenoy, M. and Mutschler, E. and Strohmann, C. and Tacke, Reinhold and Schjelderup, L. and Aasen, A. and Lambrecht, G. and Christophe, J.},
  title     = {Stereoselective interaction of procyclidine, hexahydro-difenidol, hexbutinol and oxyphencyclimine, and of related antagonists, with four muscarinic receptors},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64237},
  year      = {1992},
  abstract  = {Wc invcstigatcd thc binding properlies of thc (R)- and (Sl-cnantiomcrs of thc muscarinic antagonists trihcxyphcnidyl, procyclidinc, hcxahydro-difcnidol. p-fluoro-hcxahydro-difcnidol. hcxbutinol, p-fluoro-hcxbutinnl. and thcir corrcsponding methiodidcs at muscarinic M\(_1\), M\(_2\)• M\(_3\) and M\(_4\) receptor subtypes. In addition. binding properlies of thc (R)- and (S)-cnantiomcrs of oxyphcncycliminc wcrc studicd. The {R)- cnantiomcrs (cutomcrs} of all the compounds had a grcatcr affinity than the (S)-isomcrs for thc four muscarinic rcccptor subtypcs. Thc binding pattcrns of thc (R)- and (S)-enantiomers wcrc gcncrally different. We did not obscrvc any gcncral corrclation hctwccn thc potcncy of thc high-affinity enantiomer and Lhc affinity ratio (cudismic ratio) of the two cnantiomcrs. Thc rcsuhs arc discusscd in tcrms of a 'four suhsitcs' binding modcl.},
  subject      = {Anorganische Chemie},
  language  = {en}
}
@article{EltzeUllrichMutschleretal.1993,
  author    = {Eltze, M. and Ullrich, B. and Mutschler, E. and Moser, U. and Bungardt, E. and Friebe, T. and Gubitz, C. and Tacke, Reinhold and Lambrecht, G.},
  title     = {Characterization of muscarinic receptors mediating vasodilation in rat perfused kidney},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64283},
  year      = {1993},
  abstract  = {The muscarinic receptor mediating vasodilation of resistance vessels in the rat isolated, constant-pressure perfused kidney (preconstriction by w- 7 M cirazoline) was characterized by subtype-preferring agonists and se]ective antagonists. The agonists produced vasodi1ation with the fol1owing rank order of potency: arecaidine propargy] ester (APE) > 5-methylfurtrethonium = methacholine = oxotremorine > (S)-aceclidine > arecaidine 2-butyne-1,4-diyl bisester > 4-Cl-McN-A-343 = (R)-nipecotic acid ethyl ester = N-ethyl-guvacine propargyl ester- (R)-aceclidine = (S)-nipecotic acid ethyl ester > McN-A-343. Agonist-induced vasodilation disappeared after destruction of the endothelium with detergent. Highly significant correlations of agonist potencies for vasodilation were found between rat kidney and guinea-pig ileum submucosal arterioles as weH as agonist potencies at smooth muscle muscarinic M\(_3\) receptors of the guinea-pig ileum. The rank order of antagonist potencies (4-diphenylacetoxy-Nmethylpiperidine methiodide (4-DAMP) > (R)-hexahydro-difenidol - hexahydro-sila-difenidol > pirenzepine - p-fluorohexahydro- sila-difenidol- himbacine- AF-DX 384- AQ-RA 741 > (S)-hexahydro-difenidol) to attenuate vasodilation to APE in rat kidney, correlated significantly with affinities at M\(_3\) receptors in submucosal arterioles and in smooth muscle of the guinea-pig ileum, but differed from those at M\(_1\) and M\(_2\) receptors in rabbit vas deferens. The agonist and antagonist potencies suggest that vasodilation elicited by muscarinic stimuli in endothelium-intact rat renal vasculature is mediated by functional muscarinic M\(_3\) receptors.},
  subject      = {Anorganische Chemie},
  language  = {en}
}
@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{TackeLinohRafeineretal.1989,
  author    = {Tacke, Reinhold and Linoh, H. and Rafeiner, K. and Lambrecht, G. and Mutschler, E.},
  title     = {Synthese und Eigenschaften des selektiven Antimuscarinikums Sila-Hexocyclium-methylsulfat},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63921},
  year      = {1989},
  abstract  = {Sila-Hexocyclium-methylsulfat (7b), ein Silicium-Analogon des therapeutisch eingesetzten Antimuscarinileums Hexocyclium-methylsulfat (7a), wurde durch eine sechsstufige Synthese - ausgehend von (CH\(_3\)0)\(_3\)SiCH\(_2\)Cl - dargestellt (Gesamtausbeute 16\%). Außerdem wurden die hiervon abzuleitende freie Base 9b (f{\"u}nfstufige Synthese, ausgehend von (CH\(_3\)0)\(_3\)SiCH\(_2\)O; Gesamtausbeute 29\%) und das strukturverwandte (Aminomethyl)silanol 13 (dreistufige Synthese, ausgehend von cyclo-C\(_6\)H\(_{11}\)(C\(_6\)H\(_5\))Si(OCH\(_3\))CH\(_2\)Cl, Gesamtausbeute 46\$) synthetisiert. 7b ist ein hochwirksames und selektives Antimuscarinikum, das in der experimentellen Pharmakologie aufgrund seines bemerkenswerten Selektivit{\"a}tsprofils zur Klassifizierung von Subtypen muscarinischer Rezeptoren eingesetzt wird.},
  subject      = {Anorganische Chemie},
  language  = {de}
}
@article{TackeRafeinerStrohmannetal.1989,
  author    = {Tacke, Reinhold and Rafeiner, K. and Strohmann, C. and Mutschler, E. and Lambrecht, G.},
  title     = {Synthesis of the selective antimuscarinic agent 4-{[cyclohexylhydroxy(2-methoxyphenyl)silyl]methyl}-1,1-dimethylpiperazinium methyl sulfate (o-methoxy-sila-hexocyclium methyl sulfate)},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63930},
  year      = {1989},
  abstract  = {The synthesis of the potent and highly selective silicon-containing antimuscarinic agent o-methoxysila- hexocyclium methyl sulfate and its corresponding tertiary amine (isolated as the dihydrochloride) is described. The quarternary compound is an omethoxy derivative of sila-hexocyclium methyl sulfate, which represents one of the tools currently used in experimental pharmacology for the subclassification of muscarinic receptors. The omethoxy derivative, the pharmacological profile of which differs substantially from tbat of the nonmethoxy compound, is also recommended as a tool for the investigation of muscarinic receptor heterogeneity.},
  subject      = {Anorganische Chemie},
  language  = {en}
}
@article{WaelbroeckTastenoyCamusetal.1989,
  author    = {Waelbroeck, M. and Tastenoy, M. and Camus, J. and Christophe, J. and Strohmann, C. and Linoh, H. and Zilch, H. and Tacke, Reinhold and Mutschler, E. and Lambrecht, G.},
  title     = {Binding and functional properties of antimuscarinics of the hexocyclium/sila-hexocyclium and hexahydro-diphenidol/hexahydro-sila-diphenidol type to muscarinic receptor subtypes},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63944},
  year      = {1989},
  abstract  = {l In an attempt to assess the structural requirements for the musearlnie receptor selectivity of hexahydro-diphenidol (hexahydro-difenidol) and hexahydro-sila-diphenidol (hexahydro-sila-difenidol), a serles of structurally related C/Si pairs were investigated, along with atropine, pirenzepine and methoctramine, for their binding affinities in NB-OK 1 cells as well as in rat heart and pancreas. 2 The action of these antagonists at musearlnie receptors mediating negative inotropic responses in guinea-pig atrla and ileal contractions has also been assessed. 3 Antagonist binding data indicated that NB-OK 1 cells (M\(_1\) type) as weil as rat heart (cardiac type) and pancreas (glandularjsmooth muscle type) possess different muscarinic receptor subtypes. 4 A highly significant correlation was found between the binding affinities of the antagonists to muscarinic receptors in rat heart and pancreas, respectively, and the affinities to muscarinic receptors in guinea-pig atria and ileum. This implies that the musearlnie binding sites in rat heart and the receptors in guinea-pig atrla are essentially similar, but different from those in pancreas and ileum. 5 The antimuscarinic potency of hexahydro-diphenidol and hexahydro-sila-diphenidol at the three subtypes was inftuenced differently by structural modifications (e.g. quaternization). Different selectivity profiles for the antagonists were obtained, which makes these compounds useful tools to investigate further muscarinic receptor heterogeneity. lndeed, the tertiary analogues hexahydrodiphenidol (HHD) and hexahydro-sila-diphenidol (HHSiD) bad an M\(_1\) = glandularjsmooth muscle > cardiac selectivity profile, whereas the quaternary analogues HHD methiodide and HHSiD methiodide were M\(_1\) preferring (M\(_1\) > glandularjsmooth muscle, cardiac).},
  subject      = {Anorganische Chemie},
  language  = {en}
}