@article{AckermannTackeWannagatetal.1979, author = {Ackermann, J. and Tacke, Reinhold and Wannagat, U. and Koke, U. and Meyer, F.}, title = {Derivate des 1-(4-Chlorphenyl)silacyclohexans mit 3-(Diethylamino)propyl- und 2-(Diethylamino)ethyl-Gruppierungen}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63621}, year = {1979}, abstract = {Die Darstellung der Verbindungen 3a (sowie 3b) und 10, die sich vom 1-(4-Chlorphenyl)-1-(2~ diethylaminoethoxy)silacyclohexan (Sila-Chlorphencyclan, II a) ableiten, wird beschrieben. Die Verbindung 3 b wurde pharmakologisch und toxikologisch untersucht. Die biologischen Eigen· schaften von 3b wurden mit denen von Ila (sowie Chlorphencyclan) und seinem Hydrochiarid Ilb verglichen.}, subject = {Anorganische Chemie}, language = {de} } @article{AckermannTackeWannagatetal.1980, author = {Ackermann, J. and Tacke, Reinhold and Wannagat, U. and Koke, U. and Meyer, F.}, title = {Sila-Analoga des Chlorphencyclans}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63633}, year = {1980}, abstract = {Sila-Chlorphencyclan (8b), ein Sila-Analogon des Chlorphencyclans (8a), die Derivate 7 und 9, deren Ammoniumsalze 11, 12, 13 und 14b, das Hydrolyseprodukt 10 sowie die Vorstufen 3-6 wurden erstmalig dargestellt. Die neuen Verbindungen wurden in ihren chemischen und physikalischen Eigenschaften charakterisiert, ihre Struktur wurde sichergestellt. Chlorphencyclan, Sila-Chlorphencyclan und einige seiner Derivate wurden vergleichend pharmakologisch und toxikologisch untersucht.}, subject = {Anorganische Chemie}, language = {de} } @article{BungardtVockertFeifeletal.1992, author = {Bungardt, E. and Vockert, E. and Feifel, R. and Moser, U. and Tacke, Reinhold and Mutschler, E. and Lambrecht, G. and Suprenant, A.}, title = {Characterization of muscarinic receptors mediating vasodilation in guinea-pig ileum submucosal arterioles by the use of computer-assisted videomicroscopy}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64206}, year = {1992}, abstract = {Muscarinic receptors of rcsistance vessels (submucosal artcrioles, outside diametcr 50-75 J,Lm) from the guinea-pig small intestinc were invcstigatcd in vitro using a computcr-assisted vidcomicroscopy system (Diamtrak <~t ). The muscarinic receptor which mediates vasodilation of prccontractcd [U-46619 (300 nM) or (- )-noradrcnaline (1 0 J.L M)] artcriolcs was characterized with scveral muscarinic agonists and subtypc-sclectivc antagonists. Thc following agonists all produccd cquivalent maximum vasodilation (given in rank ordcr of potency): acctylcholinc = arccaidinc propargyl cstcr (APE) > oxotremorine = ( ± )-muscarinc = ( ± )-mcthacholinc > carbachol > 4-[[N-{4-chlorophenyl)carbamoyl]oxy]-2-hutynyltrimcthylammonium iodide (4-CI-McN-A- 343). 4-([N-(3-ChlorophcnyD-carbamoyl)oxy]-2-butynyltrimcthylammonium chloride (McN-A-343) and N-ethyl-guvacinc propargyl ester (NEN-APE) produccd minimal or no artcriolar vasodilation. Thc muscarinic antagonists pircnzcpinc, ( ± )-5,11-dihydro-11- [[[2-[2-((dipropylamino)methyl}-1-pipcridinyl]ethyl]amino ]-carbonyi]-6H-pyrido(2,3-h)( 1 ,4)-benzodiazcpin-6-onc (AF-DX 384 ), 11- [[ 4-[4-(dicthylamino)butyl]-1-piperidinyl]acetyl]-5, ll-dihydro-6H-pyrido(2.3-h)( 1,4 )-bcnzodiazepin-6-onc (AQ-RA 741 ), p-fluorohexahydro- sila-difcnidol (p-F-HHSiD), 4-diphcnylacetoxy-N-methylpipcridine mcthiodidc (4-DAMP) and (R)- and (S)hexahydro- difcnidol [(R)-HHD, (S)-HHD] shifted thc muscarinc, mcthacholinc or carbachol dosc-rcsponsc curve to the right in a compctitive manner. Schildanalysis of the data yicldcd pA\(_2\) valucs for pircnzcpinc (6.74/6.9), AF-DX 384 (6.72), AQ-RA 741 (6.58), p-F-HHSiD (7.53/7.57), 4-DAMP (9.06), (R)-HHD (7.88/8.32) and (S)-HHD (5.52/5.88). Thus, it can he concluded that submucosal arteriolcs posscss only the M\(_3\) functional muscarinic reccptor, the activation of which causcs hlood vcsscl dilation. The preparation dcscribcd is considcrcd to be a valuable now bioassay for pharmacological investigations of drug actions at muscarinic receptors in the peripheral vascular system.}, subject = {Anorganische Chemie}, language = {en} } @article{DoerjeFriebeTackeetal.1990, author = {D{\"o}rje, F. and Friebe, T. and Tacke, Reinhold and Mutschler, E. and Lambrecht, G.}, title = {Novel pharmacological profile of muscarinic receptors mediating contraction of the guinea-pig uterus}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64071}, year = {1990}, abstract = {The present study was designed to further characterize the muscarinic receptors mediating contraction of the guinea-pig uterus. The affinities of various selective muscarinic antagonists were determined and compared with those obtained at M\(_1\) (rabbit vas deferens), M\(_2\) (guinea-pig atria) and M\(_3\) receptors (guinea-pig ileum). The contractile responses of uterine smooth muscle from immature guinea-pigs to carbachol (pD\(_2\) = 5.73) were competitively antagonized by pirenzepine (pA\(_2\) = 7.04), AF-DX 116 (11-[[2-[(diethylamino)methyl]-1-piperidinyl] acetyl]- 5,11-dihydro-6H -pyrido[2,3-b][1 ,4]benzo. diazepin-6-one) (pA\(_2\) = 6.96), himbacine (pA\(_2\) = 7.92), methoctramine (pA\(_2\) = 7.52), 4-DAMP (4-diphenylacetoxy- N-methylpiperidine methiodide) (pA\(_2\) = 8.87) and sila-hexocyclium (pA\(_2\) = 8.81). A comparison of affinity values indicates that the muscarinic receptors present in guinea-pig uterus display a novel pharmacological profile which is not consistent with the presence of either an M\(_1\), M\(_2\) or M\(_3\) receptor. The affinities determined for the different antagonists rather showed a close similarity to those obtained at muscarinic receptors present in rat striatum and NG108-15 cells which are considered pharmacological equivalents (M\(_4\) receptors) of the m4 gene product. We thus hypothesize that the guinea-pig isolated uterus preparation may serve as a simple functional assay system to study the pharmacology of M\(_4\) receptors.}, subject = {Anorganische Chemie}, language = {en} } @article{DoerjeWessLambrechtetal.1991, author = {D{\"o}rje, F. and Wess, J. and Lambrecht, G. and Tacke, Reinhold and Mutschler, E. and Brann, M. R.}, title = {Antagonist binding profiles of five cloned human muscarinic receptor subtypes}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64113}, year = {1991}, abstract = {A variety of muscarinic antagonists are currently used as tools to pharmacologically subclassify muscarinic receptors into M\(_1\), M\(_2\) and M\(_3\) subtypes. ln the present study I we have determined the affinity proflies of several of these antagonists at five cloned human muscarinic receptors (m1-m5) stably expressed in Chinesehamster ovary cells (CHO-K1). At all five receptorsl the (R)-enantiomers of trihexyphenidyl and hexbutinol displayed considerably higher affinities (up to 525-fold) than their corresponding (S)-isomers. The stereoselectivity ratios [inhibition constant( S)/inhibition constant(R)] for both pairs of enantiomers were lowest at m2 receptors, suggesting that less stringent configurational demands are made by this receptor subtype. The "M\(_1\)-selective" antagonist (R)-trihexyphenidyl displayed high affinities for m1 and m4 receptors. The "M\(_2\)-selective" antagonists himbacinel (±}-5, 11-dihydro-11-1[(2-[(dipropylamino)methyl]-1- piperidinyllethyl)amino]carbonyii-6H-pyrido(213-b)(1 ~4)benzodiazepine- 6-one (AF-DX 384)1 11-(14-[4-(diethylamino)butyl)-1-piperidinyll acetyl)-5~ 11-dihydro-6H-pyrido(2~3-b) (1~4)benzodiazepine-6-one (AQ-RA 741) and (+K11-(12-[(diethylamino)methyl]-1-piperidinyll acetyl)-5~ 11-di-hydro-6H-pyrido(2~3-b)(1,4)benzodiazepine-6-one (AF-OX 250; the (+)-enantiomer of AF-DX 116] exhibited high affinities for m2 and m41 intermediate affinities for m1 and m3 and low affinities for m5 receptors. This selectivity profile was most prominent for AQ-RA 7 41 I which displayed 195- and 129-fold higher affinities for m2 and m4 receptors than for mS receptors. The "M\(_3\)-selective" antagonist (±)-p-fluoro-hexahydro-sila-difenidol hydrochloride (pFHHsiD) exhibited high affinity for m1 I m3 and m4 receptors. 4-diphenylacetoxy-N-methylpiperidine methiodide (4-DAMP) bound with up to 7 -fold higher affinities to m1 I m31 m4 and m5 receptors than to m2 receptors. Although none of the tested antagonists showed more than 2-fold selectivity for one subtype over all other subtypes, each receptor displayed a unique antagonist binding profile.}, subject = {Anorganische Chemie}, language = {en} } @article{EltzeGmelinWessetal.1988, author = {Eltze, M. and Gmelin, G. and Wess, J. and Strohmann, C. and Tacke, Reinhold and Mutschler, E. and Lambrecht, G.}, title = {Presynaptic muscarinic receptors mediating inhibition of neurogenic contractions in rabbit vas deferens are of the ganglionic M\(_1\)-type}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63912}, year = {1988}, abstract = {The present study was designed to further charaeterize the presynaptie musearlnie M\(_1\)-reeeptor responsible for the inhibition of neuragenie eontraetions in the isolated rabbit vas deferens. Eleetrically induced twiteh eontraetions of this preparation were inhibited by the M\(_1\)-agonist, MeN-A-343, and by some of its analogs: 4-ehloro-phenyl derivative> MeN-A-343 > trans-olefinie analog> cis-olefinie analog. The same rank order of potency was observed for these agonists to raise the blood pressure of pithed rats by stimulation of M\(_1\)-receptors in sympathetie ganglia. A highly signifieant eorrelation was found between the antimusearinie potencies of atropine, pirenzepine and a series of 9 antagonists strueturally related to the ganglionie M\(_{1\beta}\)-receptor selective compounds, hexocyclium and hexahydro-difenidol, to antagonize the MeN-A-343-indueed inhibition of twitch eontraetions in rabbit vas deferens or the musearine-indueed depolarization in rat isolated superior eerVieal ganglia. It is suggested that the presynaptie musearlnie receptor that mediates inhibition of neuragenie contraetions in rabbit vas deferens is of the ganglionic M\(_{1\beta}\)-type.}, 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{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{FeifelWagnerRoederStrohmannetal.1990, author = {Feifel, R. and Wagner-R{\"o}der, M. and Strohmann, C. and Tacke, Reinhold and Waelbroeck, M. and Christophe, J. and Mutschler, E. and Lambrecht, G.}, title = {Stereoselective inhibition of muscarinic receptor subtypes by the enantiomers of hexahydro-difenidol and acetylenic analogues}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64002}, year = {1990}, abstract = {1 Tbc affinities of the (R)- and (S)-enantiomers of hexahydro-difenidol (1) and its acetylenie analogues hexbutinol (2), hexbutinol methiodide (3) and p-fluoro-hexbutinol (4) (stereochemieal purity > 99.8\%) for musearlnie receptors in rabbit vas deferens (M1), guinea-pig atria (M2) and guinea-pig ileum (M3) were measured by dose-ratio experiments. 2 The (R)-enantiomers consistently showed higher aßinities than the (S)-isomers. The stereosclectivity ratios [(R)/(S)] wcrc greatest with thc enantiomers of 1 (vas deferens: 550; ilcum: 191; atria: 17) and least with thosc ofthc p-Fluoro-analogue 4 (vas defercns: 34; ileum: 8.5; atria: 1.7). 3 The enantiomerie potency ratios for compounds 1-4 were highest in rabbit vas deferens, intermediate in guinea-pig ileum and much less in guinea-pig atria. Thus, these ratios may serve as a predietor of muscarinic receptor subtype identity. 4 (S)-p-Fluoro-hexbutinol [(S)-4] showed a novel receptor selectivity profile with preference for M\(_3\) receptors: M\(_3\) > M\(_2\) \(\geq\) M\(_1\)• 5 These results do not conform to Pfeiffer's rule that aetivity differences between enantiomers are greater with more potent compounds.}, subject = {Anorganische Chemie}, language = {en} } @article{FritscheSyldatkWagneretal.1989, author = {Fritsche, K. and Syldatk, C. and Wagner, F. and Hengelsberg, H. and Tacke, Reinhold}, title = {Enzymatic resolution of rac-1,1-dimethyl-1-sila-cyclohexan-2-ol by ester hydrolysis or transesterification using a crude lipase preparation of Candida cylindracea}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63967}, year = {1989}, abstract = {No abstract available}, subject = {Anorganische Chemie}, language = {en} } @article{HengelsbergTackeFritscheetal.1991, author = {Hengelsberg, H. and Tacke, Reinhold and Fritsche, K. and Syldatk, C. and Wagner, F.}, title = {Synthesis and enantioselective enzymatic hydrolysis of rac-dimethylphenyl[1-(phenylacetamido)- ethyl]silane}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64153}, year = {1991}, abstract = {Racemic dimethylphenyl(l-(phenylacetamido)ethyl)silane [rac-5) has been made by a four-step synthesis starting from (chloromethyl)dimethylphenylsilane [PhMe\(_2\)SiCH2Cl (1) ~ PhMe\(_2\)SiCH(Cl)Me (rac-2) - PhMe\(_2\)SiCH(l)Me (rac-3) - PhMe2SiCH(NH2)Me (rac-4) ~ PhMe\(_2\)SiCH[N(H)C(O)CH\(_2\)Ph]Me ( rac-5); total yield 41\% ). Enantioselective enzymatic hydrolysis of rac-5, catalyzed by immobilized penicillin G acylase (E.C. 3.5.1.11) from Escherichia coli 5K (pHM 12), gave (R)-(1- aminoethyl)dimethylphenylsilane [( R )-4] in 40\% yield with an enantiomeric purity of 92\% ee.}, subject = {Anorganische Chemie}, language = {en} } @article{JaiswalLambrechtMutschleretal.1991, author = {Jaiswal, Neelam and Lambrecht, G{\"u}nter and Mutschler, Ernst and Tacke, Reinhold and Malik, Kafait U.}, title = {Pharmacological characterization of the vascular muscarinic receptors mediating relaxation and contraction in rabbit aorta}, series = {Journal of Pharmacology and Experimental Therapeutics}, volume = {258}, journal = {Journal of Pharmacology and Experimental Therapeutics}, number = {3}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-128358}, pages = {842-850}, year = {1991}, abstract = {Studies were performed in the rabbit aortic rings, precontracted with norepinephrine, to determine the subtype(s) of muscarinic receptors involved in endothelium-dependent relaxation and contraction in the absence of endothelium elicited by cholinergic stimuli. Acetylcholine (ACh) and arecaidine propargyl ester (APE), a M2 and M3 agonist, produced a dose-dependent relaxation and contraction in endothelium-intact and endothelium-denuded rabbit aortic rings, respectively. Both of these responses were blocked by the muscarinic receptor antagonist atropine. M1 selective agonist McN-A-343 [4-[N-(3-chlorophenyl)carbamoyloxy]-2-butinyltrimethylammonium+ ++ chloride] did not produce any effect on the tone of precontracted aortic rings. ACh- and APE-induced relaxation in aortic rings with intact endothelium was selectively blocked by M3 receptor antagonists hexahydrosila-difenidol and p-fluoro-hexahydro-sila-difenidol (pA2 of 7.84 and 7.18) but not by M1 antagonist pirenzepine or M2 receptor antagonists AF-DX 116 [11-(2-[(diethylamino)methyl]- 1-piperidinyl]acetyl)-5, 11-dihydro-6H-pyrido-[2,3-b][1,4]-benzo-diazepin-6-one] and methoctramine. ACh- and APE-induced contraction was inhibited by M2 receptor antagonists AF-DX 116 and methoctramine (pA2 of 7.11 and 6.71) but not by pirenzepine, hexahydro-sila-difenidol or p-fluoro-hexahydro-sila-difenidol. ACh- and APE-induced relaxation or contraction were not altered by nicotinic receptor antagonist hexamethonium or cyclooxygenase inhibitor indomethacin. These data suggest that relaxation elicited by cholinergic stimulin in endothelium-intact aortic rings is mediated via release of endothelium-derived relaxing factor consequent to activation of M3 receptors located on endothelial cells, whereas the contraction in aortic rings denuded of their endothelium is mediated via stimulation of M2 receptors located on smooth muscle cells.}, language = {en} } @article{KoppLambrechtMutschleretal.1989, author = {Kopp, R. and Lambrecht, G. and Mutschler, E. and Moser, U. and Tacke, Reinhold and Pfeiffer, A.}, title = {Human HT-29 colon carcinoma cells contain mucarinic M\(_3\) receptors coupled to phosphoinositide metabolism}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63989}, year = {1989}, abstract = {Five different musearlnie receptor subtypes ean be distinguished by the differenees in their amino aeid sequence, the eoupled signal transduetion system, pharmaeologieal binding properties and aetivation of ionie fluxes. The present study served to eharaeterize the binding profile of musearlnie receptors in human eolon eareinoma eells (HT-29) using seleetive musearlnie antagonists. The affinities of the compounds were eompared with their poteney to inhibit cholinergieally-aetivated phosphoinositide metabolism. Pirenzepine displaced [\(^3\)H]N-methyl-scopolamine binding and inhibited inositolphosphate (IP) release with potencies typieal of those of non-M\(_1\) receptors. The M\(_3\) subtype-selective antagonists sila-hexocyelium and hexahydro-sila-difenidol bad high affinity to the musearlnie reeeptors in HT-29 cells (K0 = 3.1 nM and 27 nM, respectively) and inhibited IP release at nanomolar concentrations. The M\(_2\) receptor antagonists, AF-DX 116 and methoctramine, had low antimusearinic poteneies. Our results demonstrate that HT-29 human colon earcinoma cells contain an apparently pure population of M\(_3\) receptors. These cells could serve as a model system for further investigations coneerning regulatory and signal transduction mechanisms associated with glandular muscarinic M\(_3\) receptors.}, subject = {Anorganische Chemie}, language = {en} } @article{LambrechtFeifelForthetal.1988, author = {Lambrecht, G. and Feifel, R. and Forth, B. and Strohmann, C. and Tacke, Reinhold and Mutschler, E.}, title = {p-Fluoro-hexahydro-sila-difenidol: the first M\(_{2\beta}\)-selective muscarinic antagonist}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63872}, year = {1988}, abstract = {No abstract available}, subject = {Anorganische Chemie}, language = {en} } @article{LambrechtFeifelWagnerRoederetal.1989, author = {Lambrecht, G. and Feifel, R. and Wagner-R{\"o}der, M. and Strohmann, C. and Zilch, H. and Tacke, Reinhold and Waelbroeck, M. and Christophe, J. and Boddeke, H. and Mutschler, E.}, title = {Affinity profiles of hexahydro-sila-difenidol analogues at muscarinic receptor subtypes}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63979}, year = {1989}, abstract = {In an attempt to assess the structural requirements of hexahydro-sila-difenidol for potency and selectivity, a series of analogues modified in the amino group and the phenyl ring were investigated for their affinity to muscarinic M1- (rabbit vas deferens), Mr (guinea-pig atria) and Mr (guinea-pig ileum) receptors. All compounds were competitive antagonists in the three tissues. Their affinities to the three muscarinic receptor subtypes differed by more than two orders of magnitude and the observed receptor selectivities were not associated with high affinity. The pyrrolidino and hexamethyleneimino analogues, compounds substituted in the phenylring with a methoxy group or a chlorine atom as weil as p-fluoro-hexahydro-difenidol displayed the same affinity profile as the parent compound, hexahydro-sila-difenidol: M1 = M3 > M2 • A different selectivity patternwas observed for p-fluoro-hexahydro-sila-difenidol: M3 > M1 > M2 • This compound exhibited its highest affinity for M3-receptors in guinea-pig ileum (pA 2 = 7.84), intermediate affinity for M1-receptors in rabbit vas deferens (pA 2 = 6.68) and lowest affinity for the Mrreceptors in guinea-pig atria (pA 2 = 6.01). This receptor selectivity profile of p-fluoro-hexahydro-sila-difenidol was confirmed in ganglia (M1), atria (M2 ) and ileum (M 3 ) of the rat. Furthermore, dose ratios obtained with either pirenzepine (Mt) or hexahydrosila- difenidol (M2 and M3) and the p-fluoro analogue used in combination suggested that the antagonism was additive, implying mutual competition with a single population of muscarinic receptor subtypes. These results indicate that p-fluoro-hexahydro-sila-difenidol represents a valuable tool for characterization of muscarinic receptor subtypes.}, subject = {Anorganische Chemie}, language = {en} } @article{LambrechtGmelinRafeineretal.1988, author = {Lambrecht, G. and Gmelin, G. and Rafeiner, K. and Strohmann, C. and Tacke, Reinhold and Mutschler, E.}, title = {o-Methoxy-sila-hexocyclium: a new quaternary M\(_1\)-selective muscarinic antagonist}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63862}, year = {1988}, abstract = {No abstract available}, subject = {Anorganische Chemie}, language = {en} } @article{MuehleisenTacke1994, author = {M{\"u}hleisen, M. and Tacke, Reinhold}, title = {Twofold deprotonated citric acid as a bidentate ligand of pentacoordinate silicon: synthesis and structural characterization of the zwitterionic \(\lambda_5\)Si-spirosilicate bis[citrato(2-)-O\(^3\),O\(^4\)][(dimethylammonio)methyl]silicate hydrate}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64388}, year = {1994}, abstract = {The zwitterionic \(\lambda_5\) Si-spirosilicate bis[ citrato(2-)-0\(^3\) ,0\(^4\) )[ ( dimethylammonio) methyl]silicate (4) was synthesized by reaction of (MeO)\(_3\)SiCH\(_2\)NMe\(_2\) (3) with citric acid (molar ratio 1 :2) in acetonitrile at room temperature and isolated, after crystallization from water, as the hydrate 4 · H\(_2\)O (yield 81 \%). The crystal structure of 4 · H\(_2\)O was studied by single-crystal X-ray diffraction. The alcoxide oxygen atoms and central carboxylate oxygen atoms of two citrato(2-) ligands and one carbon atom coordinate to the silicon atom of 4 · H\(_2\)O. The coordination polyhedron around the pentacoordinate silicon atom (SiO\(_4\)C framework) can be described as a distorted trigonal bipyramid, the two carboxylate oxygen atoms occupying the axial sites. The \(\lambda_5\) Si~silicon(IV) complex 4 also exists in solution (DMSO, H\(_2\)O).}, subject = {Anorganische Chemie}, language = {de} } @article{MuehleisenTacke1994, author = {M{\"u}hleisen, M. and Tacke, Reinhold}, title = {meso-[1,4-Piperaziniumdiylbis(methylene)]bis{bis[2-methyllactato(2-)-O1,O2]silicate} octahydrate: synthesis and crystal structure analysis of a zwitterionic dispirocyclic \(\lambda^5\)Si,\(\lambda^5\)Si'-disilicate}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64396}, year = {1994}, abstract = {The zwitterionic dispirocyclic \(\lambda^5\)Si,\(\lambda^5\)Si'-disilicate meso-[1 ,4-piperaziniumdiylbis( methylene)]bis{ bis[ 2-methyllactato(2-)-O\(^1\),O\(^2\)]silicate} octahydrate (6-8H\(_2\)O) was synthesized by reaction of 1,4-bis[(trimethoxysilyl}methyl] piperazine (8) with 2-methyllactic acid (molar ratio 1:4) in water/acetone (yield 82\%). The molecular dinuclear silicon(IV) complex 6 contains two pentacoordinate (formally negatively charged) silicon atoms and two tetracoordinate (formally positively charged) nitrogen atoms. The crystal structure of 6•8H20 was studied by X-ray diffraction.}, subject = {Anorganische Chemie}, language = {en} } @article{PolidoriMassiLambrechtetal.1990, author = {Polidori, C. and Massi, M. and Lambrecht, G. and Mutschler, E. and Tacke, Reinhold and Melchiorre, C.}, title = {Selective antagonists provide evidence that M\(_1\) muscarinic receptors may mediate carbachol-induced drinking in the rat}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64044}, year = {1990}, abstract = {The present study served to investigate the ability of seven selective muscarinic antagonists to inhibit carbachol-induced drinking in the rat. The muscarinic antagonists were given by intracerebroventricular (i.c.v.) injection 1 min before the i.c.v. injection of carbachol (1 \(\mu\)g/rat). The M\(_2\) antagonist, methoctramine, was inactive up to 80.3 nmol/rat. The M\(_3\) antagonist, p-fluoro-hexahydro-sila-difenidol, elicited a modest (42\%) but statistically significant inhibition of drinking only at 80 nmol/rat. On the other band, the selective M\(_1\) antagonists, (R)-trihexyphenidyl, o-methoxy-sila-hexocyclium and pirenzepine, produced a marked and dose-dependent inhibition of carbachol-induced drinking, their 1050 values being 0.51. 7.36 and 9.31 nmoljrat. Also the M\(_1\)/M\(_3\) antagonists, 4-diphenylacetoxy-Nmethylpiperidine methiodide and hexahydro-sila-difen.idol, were potent inhibitors of carbachol-induced drinking, their ID\(_50\) values (0.28 and 11.09 nmoljrat) being related to their pA\(_2\) values for M1 receptors in rabbi t vas deferens. These data suggest that carbachol-induced drinking may be mediated by activation of muscarinic M\(_1\) receptors.}, subject = {Anorganische Chemie}, language = {en} } @article{RettenmayrRodriguesdeMirandaRijntjesetal.1990, author = {Rettenmayr, N. M. and Rodrigues de Miranda, J. F. and Rijntjes, N. V. M. and Russel, F. G. M. and van Ginneken, C. A. M. and Strohmann, C. and Tacke, Reinhold and Lambrecht, G. and Mutschler, E.}, title = {Pharmacokinetic properties of the antimuscarinic drug [\(^3\)H]-hexahydro-sila-difenidol in the rat}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64022}, year = {1990}, abstract = {The pharmacokinetics of tritiated hexahydrosila- difenidol ([\(^3\)H]-HHSiD) were examined in rats. Furthermore, the distribution of radioactivity was studied by means of whole body autoradiography. After i. v. administration of 2.9 mg/kg HHSiD plus [\(^3\)H]-HHSiD to anaesthetized rats bearing a catheter implanted in the ductus choledochus and receiving a mannitol infusion, HHSiD was rapidly distributed and metabolized. Only 5\% ofthe radioactivity was recovered in blood after 23 s and 0.4\% after 2.5 h. 64\% of the plasma radioactivity could be extracted with hexane from the samples taken 23 s after administration. 52\% of the radioactivity was eliminated within 2.5 h, 13\% by urinary and 39\% by biliary excretion. Following oral administration of 8.6 mg/kg HHSiD plus [\(^3\)H]-HHSiD there was an absorption of approximately one fourth of the administered radioactivity within 4 h. By means of whole body autoradiography (i. v. injection) as well as by tissue distribution measurement the highest Ievels of radioactivity were found in bile, urine, lung, kidney, adrenals, liver and .pancreas. Thus, after i. v. administration to rats HHSiD is rather quickly distributed, metabolized and excreted. This explains its low antimuscarinic potency in vivo.}, subject = {Anorganische Chemie}, language = {en} } @article{SaadTacke1977, author = {Saad, S. M. and Tacke, Reinhold}, title = {Zur Darstellung von 1,1,3,3-Tetramethyl-1,3-disila-2,4,7-trioxa-cycloheptan (1) und 1,1,3,3-Tetramethyl-1,3-disila-2,4,8-trioxa-cyclooctan (2)}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86958}, year = {1977}, abstract = {No abstract available.}, subject = {Anorganische Analyse}, language = {de} } @article{SargeCammengaBeckeretal.1988, author = {Sarge, S. and Cammenga, H. K. and Becker, B. and Rohr-Aehle, R. and Tacke, Reinhold}, title = {Energetic and kinetic investigation of thermally induced molecular rearrangements of esters of (hydroxymethyl)hydridosilanes by DSC}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63850}, year = {1988}, abstract = {No abstract available}, subject = {Anorganische Chemie}, language = {en} } @article{SchomburgLinkLinohetal.1988, author = {Schomburg, D. and Link, M. and Linoh, H. and Tacke, Reinhold}, title = {Molek{\"u}lstruktur der Akarizide Chlortrineophylstannan, Chlortris[(dimethylphenylsilyl)methyl]stannan und Trineophyl(1,2,4-triazol-1-yl)stannan-hemihydrat sowie des 2,5-Dimethyl-2,5-diphenylhexans (Bineophyl)}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63840}, year = {1988}, abstract = {Die Kristall- und Molek{\"u}lstrukturen der Akarizide Chlortrineophylstannan (Ia), Chlortris[ ( dimethylphenylsilyl)methyl]stannan (tb) und Trineophyl(1,2,4-triazol-1- yl)stannan-hemihydrat (2a · 0.5H\(_2\)0) wurden durch Einkristall-R{\"o}ntgenstrukturanalysen bestimmt. Zu V ergleichszwecken wurde ausserdem die Struktur des 2,5-Dimethyl-2,5-diphenylhexans (Bineophyl, 4) untersucht. Die Kn{\"u}pfung von drei sehr raumerf{\"u}llenden N eophyl-Resten an ein Zinnatom f{\"u}hrt zu einer deutlichen Verzerrung der tetraedrischen Geometrie [ta: C-Sn-C 117.2°, C-Sn-Cl99.7°; 2a·0.5H20: C-Sn-C 116.9° (Mittelwert), C-Sn-N 100.2° (Mittelwert)]. Austausch der zentralen Kohlenstoffatome in den Neophyt-Substituenten von la durch Siliciumatome f{\"u}hrt zu einer Verringerung des Raumbedarfs und dadurch zu einer erkennbaren Angleichung an die tetraedrische Geometrie [lb: C-Sn-C 113.3° (Mittelwert), C-Sn-Cl 105.3° (Mittelwert)].}, 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{SperlichBechtMuehleisenetal.1993, author = {Sperlich, J{\"o}rg and Becht, Joachim and M{\"u}hleisen, Mathias and Wagner, Stephan A. and Mattern, G{\"u}nter and Tacke, Reinhold}, title = {Zwitterionische Bis[vic-arendiolato(2-)][(morpholinio)alkyl]silicate: Synthese sowie strukturelle Charakterisierung in L{\"o}sung und im Kristall}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-73153}, year = {1993}, abstract = {No abstract available.}, subject = {Silicate}, language = {de} } @article{SteilingTackeWannagat1979, author = {Steiling, L. and Tacke, Reinhold and Wannagat, U.}, title = {Diphenyl(3-piperidinopropyl)silanol, ein Sila-Analogon des Difenidols}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63618}, year = {1979}, abstract = {Diphenyl(3-piperidinopropyl)silanol (6b), ein Sila-Analogon des Arzneimittels Difenidol (6a), und dessen Methoiodid 7 wurden erstmals gem{\"a}ß Schema 1 synthetisiert. - Die pharmakologischen und toxikologischen Eigenschaften der Analoga 6a und 6b wurden vergleichend untersucht.}, subject = {Anorganische Chemie}, language = {de} } @article{StrohmannBauereckerCammengaetal.1991, author = {Strohmann, C. and Bauerecker, S. and Cammenga, H. K. and Jones, P. G. and Mutschler, E. and Lambrecht, G. and Tacke, Reinhold}, title = {Enantiomers of the muscarinic antagonist 1-cyclohexyl-1-(4-fluorophenyl)-4-piperidino-1-butanol (p-fluoro-hexahydro-difenidol): synthesis, absolute configuration, and enantiomeric purity}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64144}, year = {1991}, abstract = {The enantiomers of the antimuscarinic agent 1-cyclohexyl-1- (4-fluorophenyl)-4-piperidino-1-butanol [(R)- and (S)-p-fluorohexahydro- difenidol] ((R)- and (S)-2a] and their methiodides (R)- 3 and (S)-3 were prepared with high enantiomeric purity. (R)- 2a and (S)-2a (isolated as hydrochlorides) were obtained by catalytic hydrogenation (Pd/C contact) of the corresponding enantiomers of 1-cyclohexyl-1-( 4-fl uorophen yl)-4-piperidino- 2-butyn-1-ol [(R)- and (S)-4]. Reaction of (R)-2a and (S)-2a with rnethyl iodide led to (R)-3 and (S)-3, respectively. The unsaturated precursors (R)- and (S}-4 (enantiorneric purity ~ 99.80 and ~99.94\% e.e.; calorimetric analysis) were prepared by res-sepaolution of rac-4 [available from 4-FC\(_6\)H\(_4\)C(O)C\(_6\)H\(_{11}\) by reaction with LiC ~ CCH\(_2\)NC\(_5\)H\(_{10}\)] using (R)- and (S)-mandelic acid as resolving agents. The absolute configurations of the (R) and (S) enantiomers of 2a, 3, and 4 were determined by an X-ray crystal-structure analysis of (S)-5, the methiodide of (S)-4. (R)- 2a and (R)-3 exhibit a higher affinity for muscarinic M1, M2, M3, and M4 receptors (by up to two orders of magnitude) than their corresponding antipodes (S)-2a and (S)-3, the degree of stereoselectivity depending on the receptor subtype involved. (R)-2a represents a useful tool for rnuscarinic receptor research (affinity profile: M1 ~ M3 ~ M4 > M2).}, subject = {Anorganische Chemie}, language = {en} } @article{StrohmannTackeMatternetal.1991, author = {Strohmann, C. and Tacke, Reinhold and Mattern, G. and Kuhs, W. F.}, title = {Bis(2,3-naphthalindiolato)[2-(pyrrolidinio)ethyl]silicat: Synthese und strukturelle Charakterisierung eines zwitterionischen \(\lambda_5\)-Spirosilicates}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64095}, year = {1991}, abstract = {The zwi tterionic spirocyclic bis(2,3-naphthalenediolato )[2-(pyrrolidinio )ethyl]silicate [ ( C\(_{10}\)H\(_6\)O\(_2\)-SiCH\(_2\)CH\(_2\)(H)NC\(_4\)H\(_8\), 3 was synthesized and its structure characterized (single crystal X-ray structural analysis; \(^1\)H, \(^{13}\)C and \(^{29}\)Si NMR studies of solutions in DMSO). 3 was obtained by reaction of cyclohexylmethoxyphenyl(2-pyrrolidinoethyl)silane [C\(_6\)H\(_{11}\)(CH\(_3\)O)Si(C\(_6\)H\(_5\))CH\(_2\)CH\(_2\) NC\(_4\)H\(_8\), 4] with 2,3-dihydroxynaphthalene [C\(_{10}\)H\(_6\)(OH)\(_2\)] in acetonitrile at room temperature (isolated as 3·CH\(_3\)CN, yield 81 \%). The formation of 3 involves two unusual Si-C cleavage reactions (cleavage of Si-C\(_6\)H\(_5\) and Si-C\(_6\)H\(_{11}\) under mild reaction conditions). In addition, 3 was prepared by reaction of 2,3-dihydroxynaphthalene with dimethoxyphenyl(2-pyrrolidinoethyl)silane [C\(_6\)H\(_5\) (CH\(_3\)O)\(_2\)SiCH\(_2\)CH\(_2\)NC\(_4\)H\(_8\) , 5] and trimethoxy( 2-pyrrolidinoethyl)silane [(CH\(_3\)O)\(_3\)SiCH\(_2\)CH\(_2\)NC\(_4\)H\(_8\), 6], respectively (isolated as 3·CH\(_3\)CN; yields 83 and 86\%, respectively). 3·CH\(_3\)CN crystallizes in the space group Pbca with a = 8.877(2) A. b-= 22.823(4) {\"A}, c""" 24.597(4) A, and Z = 8 (R- 0.0592, Rw = 0.0529). The pentacoordinated Si atom of 3·CH\(_3\)CN is surrounded by its ligands in a nearly ideal square-pyramidal fashion (four basal 0 atoms and one apical C atom). The CH3CN molecule does not coordinate to the Si atom.}, subject = {Anorganische Chemie}, language = {de} } @article{SyldatkAndreeStoffregenetal.1987, author = {Syldatk, C. and Andree, H. and Stoffregen, A. and Wagner, F. and Stumpf, B. and Ernst, L. and Zilch, H. and Tacke, Reinhold}, title = {Enantioselective reduction of acetyldimethylphenylsilane by Trigonopsis variabilis (DSM 70714)}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63836}, year = {1987}, abstract = {Growing and resting cells of the yeast Trigonapsis variabilis (DSM 70714) can be used for the enantioselective reduction of the organosilicon compound acetyldimethylphenylsilane (J) to give optically active (R)-(1-hydroxyethyl)dimethylphenylsilane [(R)-2] in good yields. The enantiomeric purity of the isolated product was determined tobe 62-86\% ee depending on the substrate concentration used. Both substrate and product caused an inhibition of the reaction at concentrations higher than 0.35 and 0.5 g/1, respectively. Besides, higher substrate and product concentrations led to increased formation of the by-product 1,1,3,3-tetramethyl-1,3-diphenyldisiloxane. Considering the limiting substrate and product concentrations, it was possible to use the same biomass at least 5 times without significant loss of enzyme activity. 3-Methyl-3-phenyl-2-butanone (5) and acetyldimethylphenylgermane (7), which represent carbon and germanium analogues of 1, were also found to be accepted as substrates by Trigonapsis variabilis (DSM 70714). The reduction rates of the silicon {1) and germanium compound {7) were much higher than the transformation rate of the corresponding carbon analogue 5.}, subject = {Anorganische Chemie}, language = {en} } @article{SyldatkStoffregenWuttkeetal.1988, author = {Syldatk, C. and Stoffregen, A. and Wuttke, F. and Tacke, Reinhold}, title = {Enantioselective reduction of acetyldimethylphenylsilane: a screening with thirty strains of microorganisms}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63906}, year = {1988}, abstract = {Thirty strains of microorganisms (bacteria, yeasts, fungi and green algae) were tested as resting free cells for their ability to transform acetyldimethylphenylsilane (1) enantioselectively into (R)-(1-hydroxyethyl) dimethylphenylsilane [(R)-2]. The biotransformations were monitared by GC (packed OV-17 column), and the enantiomeric purities of the products isolated were determined by HPLC (cellulose triacetate column, UV detection). All microorganisms tested were found to reduce 1 enantioselectively to give (R)-2. Under the test conditions used, the yeast Trigonapsis variabilis (DSM 70714) was found to 1 exhibif the highest specific activity (1.5 mg product x g cell wet mass\(^{-1}\) x min\(^{-1}\) ), whereas the highest enantioselectivities were observed for the bacteria Acinetobacter ca lcoaceticus (ATCC 31012) (>95\% ee), Brevfbacterium species (ATCC 21860) (90\% ee) and Corynebacterium dioxydans (ATCC 21766) (>95\% ee), the yeast Candida humico la (OSM 70067) (90\% ee), the fungus Cunninghame lla e legans (ATCC 26269) (94\% ee), as well as the cyanobacterium Synechococcus leopoliensis (94\% ee).· From the green algae tested, Chlamydomonas reinhardii showed the highest.enantioselectivity (85\% ee).}, subject = {Anorganische Chemie}, language = {en} } @article{Tacke1977, author = {Tacke, Reinhold}, title = {Sila-Analoga des Meflophenhydramins}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63594}, year = {1977}, abstract = {Die Sila-Analoga A, 8, C des Antihistaminikums Meflophenhydramin, sowie die Derivate D und E, das Hydrolyseprodukt 8 und die Vorstufen 3-7 wurden dargestellt. Die chemischen und physikalischen Eigenschaften aller Verbindungen und das pharmakologische Verhalten von A-D und 8 wurden untersucht.}, subject = {Anorganische Chemie}, language = {de} } @article{TackeBechtLopezMrasetal.1993, author = {Tacke, Reinhold and Becht, J. and Lopez-Mras, A. and Sheldrick, W. S. and Sebald, A.}, title = {Syntheses, X-ray crystal structure analyses, and solid-state NMR studies of some zwitterionic organofluorosilicates}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64272}, year = {1993}, abstract = {No abstract available}, subject = {Anorganische Chemie}, language = {en} } @article{TackeBechtMatternetal.1992, author = {Tacke, Reinhold and Becht, J. and Mattern, G. and Kuhs, W. F.}, title = {Zur Existenz zwitterionischer \(\lambda_5\)-(Ammonioorganyl)tetrafluorosilicate: Synthese sowie Kristall- und Molek{\"u}lstruktur von Tetrafluoro(pyrrolidiniomethyl)silicat}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64217}, year = {1992}, abstract = {The zwitterionic tetrafluoro(pyrrolidiniomethyl)silicate (6) was synthesized by the reaction of trimethoxy(pyrrolidinomethyl) silane (7) with hydrogen fluoride in ethanol/hydrofluoric acid (yield 83\%). 6 crystallizes in the space group P2\(_1\)fc with two crystallographically distinct molecules in the asymmetric unit. In both molecules the pentacoordinate silicon atom is surrounded by four fluorine atoms and one carbon atom, the latter being in an equatorial position. The coordination polyhedron of the silicon atoms can be described as a slightly distorted trigonal bipyramid. The zwitterionic structure was also proved for dissolved 6 (solution in CD\(_3\)CN, NMRspectroscopic studies).}, subject = {Anorganische Chemie}, language = {de} } @article{TackeBecker1988, author = {Tacke, Reinhold and Becker, B.}, title = {Synthese und Eigenschaften von (Hydroxymethyl)dimethylgerman und (Hydroxymethyl)diphenylgerman}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63895}, year = {1988}, abstract = {Die (Hydroxymethyl)diorganylgermane (CH\(_3\))\(_2\)Ge(H)CH\(_2\)OH und (C\(_6\)H\(_5\))\(_2\)Ge(H)CH\(_2\)OH wurden - ausgehend von GeCl\(_4\) - durch eine jeweils vierstufige Synthese mit einer Gesamtausbeute von 15 bzw. 32\% dargestellt (GeCl\(_4\) ---+ Cl\(_3\)GeCH\(_2\)Cl -> R \(_2\)Ge(Cl)CH \(_2\)Cl ->R \(_2\)Ge(OAc)CH\(_2\)OAc--) R \(_2\)Ge(H)CH\(_2\)OH; R = CH\(_3\) bzw. C\(_6\)H\(_5\) ). Die chemische Reaktivit{\"a}t der Germane (CH\(_3\))\(_2\)Ge(H)CH\(_2\)OH und (C\(_6\)H\(_5\))\(_2\)Ge(H)CH\(_2\)OH wird durch deren Ge-H- und 0-H-Bindung bestimmt.}, subject = {Anorganische Chemie}, language = {de} } @article{TackeBeckerBergetal.1992, author = {Tacke, Reinhold and Becker, B. and Berg, D. and Brandes, W. and Dutzmann, S. and Schaller, S.}, title = {Bis(4-fluorophenyl)methyl(1H-1,2,4-triazol-1-yl-methyl)germane, a germanium analogue of the agricultural fungicide flusilazole: synthesis and biological properties}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64224}, year = {1992}, abstract = {Bis( 4-fluorophenyl)methyl(l H-1,2,4-triazol-1-yl-methyl)germane (2), a germanium analogue of the agricultural fungicide flusilazole (1), has been synthesized from Cl\(_3\)GeCH\(_2\)CI (3) by both a three-step and a four-step synthesis (3-> (p-F-C\(_6\)H\(_4\))\(_2\)Ge(CH\(_2\)Cl)Br (4)-> (p-F-C\(_6\)H\(_4\))\(_2\)Ge(CH\(_2\)CI)CH\(_3\) (S)-> 2; S ~ (p-F-C\(_6\)H\(_4\))\(_2\)Ge(CH\(_2\)I)CH\(_3\) (6)-> l). The fungicidal properties of l have been compared with those of the parent silicon compound 1 (studies on Si/Ge bioisosterism). In various test systems, the SijGe analogues 1 and 2 showed comparable fungicidal properlies (in activity against plant pathogenic fungi: in agar plate diffusion tests and greenhause evaluations; in activity against human pathogenic fungi: in serial dilution tests). In addition, 1 and 2 displayed comparable potencies in respect of sterol biosynthesis inhibition in Sacclulromycopsis {\"u}polytica and Pyricularia oryzae, the mode of action being primarily an inhtbition of oxidative C14-demethylation.}, subject = {Anorganische Chemie}, language = {en} } @article{TackeBeckerLange1990, author = {Tacke, Reinhold and Becker, B. and Lange, H.}, title = {(Thioacetoxy-S-methyl)diorganylsilane und (Mercaptomethyl)diorganylsilane: Synthese und Eigenschaften}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64065}, year = {1990}, abstract = {Die erstmalige Synthese der (Thioacetoxy-S-methyl)diorganylsilane (CH\(_3\))\(_2\)Si(H)CH\(_2\)SC(O)CH\(_3\) (9) und (C\(_6\)H\(_5\))\(_2\)Si(H)CH\(_2\)SC(O)CH\(_3\) (10) und der (Mercaptomethyl) diorganylsilane (CH\(_3\))\(_2\)Si(H)CH\(_2\)SH (11) und (C\(_6\)H\(_5\))\(_2\)Si(H)CH\(_2\)SH (12) wird beschrieben. W{\"a}hrend sich die Silane 9 und 10 leicht handhaben lassen, neigen die strukturanalogen (Hydroxymethyl)diorganylsilane (CH\(_3\))\(_2\)Si(H)CH\(_2\)OH (1) und (C\(_6\)H\(_5\))\(_2\)Si(H)CH\(_2\)OH (2) zu einer basenkatalysierten Zersetzung (Bildung oligomerer (polymerer) Alkoxysilane und Wasserstoff). Im Gegensatz zu den thermisch labilen (Acetoxymethyl)diorganylsilanen (CH\(_3\))\(_2\)Si(H)CH\(_2\)OC(O)CH\(_3\) (3) und (C\(_6\)H\(_5\))\(_2\)Si(H)CH\(_2\)OC(O)CH\(_3\) (4) (--+ Umlagerung zu den entsprechenden Acetoxy(methyl) diorganylsilanen (CH\(_3\)) \(_3\)SiOC(O)CH\(_3\) (5) und CH\(_3\)(C\(_6\)H\(_5\))\(_2\)SiOC(O)CH\(_3\) {6)) sind die Thio-Analoga 9 und 10 thermisch stabil (I-molare L{\"o}sungen in C\(_6\)D\(_6\), 30 h bei 180 o C).}, subject = {Anorganische Chemie}, language = {de} } @article{TackeBentlageTowartetal.1983, author = {Tacke, Reinhold and Bentlage, Anke and Towart, Robertson and M{\"o}ller, Eike}, title = {Sila-pharmaca, XXV. Sila-analogues of nifedipine-like dialkyl 2,6-dimethyl-4-aryl-1,4 dihydropyridine-3,5-dicarboxylates, III}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-78357}, year = {1983}, abstract = {IS neue C/Si-Analogenpaare (C-Verbindungen und sila- bzw. disila-substituierte Derivate), die sich strukturell vom Nifedipin ableiten, wurden synthetisiert. Diese und einige weitere C/Si-Paare wurden hinsichtlich ihrer physikochemischen und pharmakologischen Eigenschaften vergleichend untersucht. Mittels reversed-phase-D{\"u}nnschichtchromatographie wurde gezeigt, daß die Sila- bzw. Disila-Analoga lipophiler sind als die entsprechenden C-Verbindungen. Bez{\"u}glich der spasmolytischen in vitra-Aktivit{\"a}ten zeigen die Si-Verbindungen in erster N{\"a}herung {\"a}hnliche Struktur-Wirkungs-Beziehungen wie ihre Carba-Analoga. Dagegen konnten hinsichtlich der ill vlva-Effekte (cardiovascul{\"a}re und antihypertensive Aktivit{\"a}t) in einigen F{\"a}llen große Unterschiede nachgewiesen werden.}, subject = {Anorganische Chemie}, language = {en} } @article{TackeBentlageFeltenLinohetal.1986, author = {Tacke, Reinhold and Bentlage-Felten, Anke and Linoh, Haryanto and Magda, Stephen}, title = {Sila-Analoga des Triparanols und Ethamoxytriphetols: Synthese sowie pharmakologische und toxikologische Eigenschaften}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86940}, year = {1986}, abstract = {No abstract available.}, language = {de} } @article{TackeBentlagemTowartetal.1980, author = {Tacke, Reinhold and Bentlagem, A. and Towart, R. and Meyer, H. and Bossert, F. and Vater, W. and Stoepe, K.}, title = {Sila-Analoga von Nifedipin-{\"a}hnlichen 4-Aryl-2.6-dimethyl-1.4-dihydropyridin-3.5-dicarbons{\"a}ure-dialkylestern, I}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-82430}, year = {1980}, abstract = {no abstract available}, subject = {Chemie}, language = {de} } @article{TackeBrakmannWuttkeetal.1991, author = {Tacke, Reinhold and Brakmann, S. and Wuttke, F. and Fooladi, J. and Syldatk, C. and Schomburg, D.}, title = {Stereoselective microbial reduction of racemic acetyl(t-butyl)methylphenylsilane by Trigonopsis variabilis (DSM 70714) and Corynebacterium dioxydans (ATCC 21766)}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64109}, year = {1991}, abstract = {(SiR,CR)- and (SiS,CR)-t-butyl(l-hydroxyethyl)methylphenylsilane [(SiR,CR)-2 and (SiS,CR)-3] have been prepared by (R)-selective microbial rcduction of racemic acetyl(t-butyl)methylphenylsilane (rac-1) using resting free cells of the yeast Trigonopsis variabilis (DSM 70714) or the bacterium Corynebacterium dioxydans (ATCC 21766). The biotransfonnations were carried out on a 10 g scale. Afterseparation by column chromatography on silica gel, the optically active diastereomers (SiR,CR)-2 and (SiS,CR)-3 produccd by T. variabilis were obtained in good yields [74\% ((SiR,CR)-2). 78\% ((SiS,CR)-3)]. The products obtained from the reduction with C. dioxydans were isolated in significantly lower yields [20\% ((SiR,CR)-2), 20\% ((SiS,CR)-3)]; reaction conditions not optimized). Both bioconversions gave products with high enantiomeric purities (T. variabilis: 91\% ee ((SiR,CR)-2), 96\% ee ((SiS,CR)-3); C. dioxydons: ~ 991 ee ((SiR,CR)-l), ~ 99\% ee ((SiS,CR)-3)). To throw light on the stereochemical aspects of these biotransfonnations, an X-ray diffraction study was carried out on the 3,5-dinitrobenzoate of rac-(SiR,CS/SiS,CR)-3. In addition, 1H NMR spectroscopic stereochemical correlation studies were performed with the (S)-MTPA esters derived from (SiR,CR)-l, (SiS,CR)-3, rac-(SiR,CRjSiS,CS)-2 and rac-(SiR,CSjSiS,CR)-3 [rac-(SiR,CR/ SiS,CS)-2 and rac-(SiR,CS/SiS,CR)-3 were obtained by reduction of rac-1 with LiAIH\(_4\) in diethylether, followed by chromatographic separation of the diastereomers on silica gel]. These stereochemical studies allowed assignment of the absolute configurations and enantiomeric purities of the biotransformation products.}, subject = {Anorganische Chemie}, language = {en} } @article{TackeFritscheTafeletal.1990, author = {Tacke, Reinhold and Fritsche, K. and Tafel, A. and Wuttke, F.}, title = {Synthese von racemischem Acetyl(t-butyl)methylphenylsilan und Acetylmethylphenyl[(trimethylsilyl)methyl]silan: Substrate f{\"u}r stereoselektive mikrobielle Reduktionen}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64055}, year = {1990}, subject = {Anorganische Chemie}, language = {de} } @article{TackeFrohneckeNiedner1982, author = {Tacke, Reinhold and Frohnecke, J. and Niedner, R.}, title = {Darstellung und Eigenschaften potentiell curarewirksamer Silicium-Verbindungen, IV}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63711}, year = {1982}, abstract = {Die Synthese der Organosilicium· Verbindungen 3 a- d wird erstmalig beschrieben. Sie wurden durch ihre physikalischen, chemischen und pharmakologischen Eigenschaften charakterisiert. Ja- d wirken als uKurzzeit-Muskelrelaxantien", deren Entgiftung durch Hydrolyse der Si- OeBindungen (Sollbruchstellen) erfolgt.}, subject = {Anorganische Chemie}, language = {de} } @article{TackeHallerZeiler1979, author = {Tacke, Reinhold and Haller, Ingo and Zeiler, Hans-Joachim}, title = {Sila-Analoga der Antiseptica Octafoniumchlorid und p-tert-Butylphenol}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86893}, year = {1979}, abstract = {No abstract available.}, subject = {Silaanaloga}, language = {de} } @article{TackeHeegBerndt1980, author = {Tacke, Reinhold and Heeg, E. and Berndt, B}, title = {Sila-Analogon des Rythmols}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63642}, year = {1980}, abstract = {Sila-Rythmol (llb), ein Sila-Analogon des Antiarrhythmieums Rythmol (lla), wurde erstmalig dargestellt. llb sowie die Vorstufen und Nebenprodukte 4, 5, 6, 7, 9b und lOb wurden in ihren physikalischen und chemischen Eigenschaften charakterisiert und in ihrer Struktur sichergestellt. Die pharmakologischen und toxikologischen Eigenschaften der Analoga lla und llb wurden vergleichend untersucht.}, subject = {Anorganische Chemie}, language = {de} } @article{TackeHengelsbergKlingneretal.1992, author = {Tacke, Reinhold and Hengelsberg, H. and Klingner, E. and Henke, H.}, title = {Synthese der Si-funktionellen Acetylsilane tBu(Me\(_3\)SiCH\(_2\))[MeC(O)]SiF und tBu(Me\(_3\)SiCH\(_2\))[MeC(O)]SiH sowie Synthese und Kristallstruktur des Acetylsilanols tBu(Me\(_3\)SiCH\(_2\))[MeC(O)]SiOH: Substrate f{\"u}r mikrobielle Reduktionen}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64192}, year = {1992}, abstract = {The racemic Si-functional acetylsilanes tBu(Me\(_3\)SiCH\(_2\))[ MeC(O)]SiF (1) and tBu(Me\(_3\)SiCH\(_2\))[MeC(O)]SiH (2) and the racemic acetylsilanol tBu(Me\(_3\)SiCH\(_2\))[MeC(O)]SiOH (3) were synthesized from Si(OMe)\(_4\) (4) as substrates for microbial reductions [4 -> tBuSi(OMe)\(_3\) (5) -> tBu(Me\(_3\)SiCH\(_2\))Si(OMe)\(_2\) (6) -> tBu(Me\(_3\)SiCH\(_2\))SiF\(_2\) (7)-> tBu(Me\(_3\)SiCH\(_2\))(CH\(_2\) = C(OMe))SiF (8) -> 1; 8 -> tBu(Me\(_3\)SiCH\(_2\))[CH\(_2\) = C(OMe)]SiH (9) -> 2; 6 -> tBu(Me\(_3\)SiCH\(_2\))[CH\(_2\) = C(OMe)]SiOMe (10) -> 3]. Compounds 1-3 were found to be reduced by cells of Trigonapsis variabilis (DSM 70714) ( = SiC(O)Me -> = SiCH(OH)Me}. The crystal and molecular structure of 3 was studied by singlecrystal X-ray diffraction. In the crystal, racemic 3 forms infinite chains built up by intermolecular 0-H .. ·O bonds between the hydroxyl and acetyl groups of molecules of the same absolute configuration.}, subject = {Anorganische Chemie}, language = {de} } @article{TackeHengelsbergZilchetal.1989, author = {Tacke, Reinhold and Hengelsberg, H. and Zilch, H. and Stumpf, B.}, title = {Enantioselective microbial reduction of 1,1-dimethyl-1-sila-cyclohexan-2-one with growing cells of the yeast Kloeckera corticis (ATCC 20109)}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64010}, year = {1989}, abstract = {(R)-1,1-Dimethyl-1-sila-cyclohexan-2-ol [(R)-2] was prepared by enantioselective microbial reduction of 1,1-dimethyl-1-sila-cyclohexan-2-one (1) with growing cells of the yeast Kloeckera corticis (ATCC 20109). At a substrate concentration of 0.5 g/1 (temperature 27° C, incubation time 16 h), (R}-2 was obtained on a preparative scale in 60\% yield and with an enantiomeric purity of 92\% ee. Repeated recrystallization of the biotransformation product from n-hexane raised the enantiomeric purity to 99\% ee.}, subject = {Anorganische Chemie}, language = {en} } @article{TackeKropfgansTafeletal.1994, author = {Tacke, Reinhold and Kropfgans, Martin and Tafel, Andrea and Wiesenberger, Frank and Sheldrick, William S. and Mutschler, Ernst and Egerer, Hansj{\"o}rg and Rettenmayr, Nikola and Gross, Jan and Waelbroeck, Magali and Lambrecht, G{\"u}nter}, title = {(Hydroxymethyl)diphenyl(piperidinoalkyl)silane des Typs (HOCH2)(C6H5)2Si(CH2)nNC5H10 (n = 2,3) und deren Methoiodide: Synthese, Struktur und antimuscarinische Eigenschaften}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86904}, year = {1994}, abstract = {No abstract available.}, language = {de} } @article{TackeLange1983, author = {Tacke, Reinhold and Lange, H.}, title = {Thermisch induzierte Umlagerung von (Acyloxymethyl)- diorganylsilanen}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63752}, year = {1983}, abstract = {Die (Acyloxymethyl)diorganylsilane R\(^1\)R\(^2\)Si(H)CH\(_2\)OC(O)R\(^3\) (2a- d) unterliegen einer thermisch induzierten Umlagerung zu den entsprechenden Acyloxy(methyl)diorganylsilanen R\(^1\)R\(^2\)Si(CH\(_3\))OC(O)R\(^3\) (3a- d). Diese Reaktion beinhaltet formal einen Austausch des am Silicium gebundenen Wasserstoffs mit dem am Kohlenstoff gebundenen Acyloxy-Rest. Bez{\"u}glich der 1,2- Wasserstoff-Verschiebung konnte experimentell ein intramolekularer Prozeß bewiesen werden.}, subject = {Anorganische Chemie}, language = {de} } @article{TackeLangeAttarBashi1982, author = {Tacke, Reinhold and Lange, H. and Attar-Bashi, M. T.}, title = {Baseninduzierte 1,2-Hydridverschiebungen vom Silicium zum Kohlenstoff: "Anomale" Substitutionsreaktionen an (Halogen-methyl)diorganylsilanen}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63734}, year = {1982}, abstract = {(C\(_6\)H\(_5\))\(_2\)Si(H)CH\(_2\)X (1 a: X = Cl; 1 b: X = I) und C\(_6\)H\(_5\)(CH\(_3\))Si(H)CH\(_2\)CI (10) reagieren mit LiOCH\(_2\)CH\(_2\)N(CH\(_3\))\(_2\) (2b) zu den Alkoxysilanen (C\(_6\)H\(_5\))\(_2\)Si(CH\(_3\))OCH\(_2\)CH\(_2\)N(CH\(_3\))\(_2\) (5) bzw. C\(_6\)H\(_5\)(CH\(_3\))\(_2\)SiOCH\(_2\)CH\(_2\)N(CH\(_3\))\(_2\) (12). Die Bildung dieser unerwarteten Reaktionsprodukte wird durch einen nucleophilen Angriff des Alkoxids am Si-Atom gedeutet. dem sich eine intramolekulare 1 ,2-Hydridverschiebung vom Si zum C und Eliminierung von Cl e anschließt. Mit weichen Basen, wie z. B. I (-) und (-)SCH\(_2\)CH\(_2\)N(CH\(_3\))\(_2\), wurden dagegen "normale" Substitutionsreaktionen am C-Atom der SiCH\(_2\)Cl-Gruppe beobachtet}, subject = {Anorganische Chemie}, language = {de} } @article{TackeLangeBentlage1982, author = {Tacke, Reinhold and Lange, H. and Bentlage, A.}, title = {Synthese und Eigenschaften von (Hydroxy-methyl)diorganylsilanen}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63727}, year = {1982}, abstract = {The synthesis of the (hydroxymethyl)diorganylsilanes R\(^1\)R\(^2\)Si(H)CH\(_2\)OH (4a: R\(^1\) = R\(^2\) = CH\(_3\), 2-silaisobutanol; 4b: R\(^1\) = CH\(_3\), R\(^2\) == C\(_6\)H\(_5\); 4c: R\(^1\) == R\(^2\) = C\(_6\)H\(_5\))is achieved bythereactionof R\(^1\)R\(^2\)Si(Cl)CH\(_2\)Cl (2a-c) with AcOH/NEt\(_3\) to R\(^1\)R\(^2\)Si(OAc)CH\(_2\)OAc (Ja-c), followed by treating with LiAlH\(_4\) and hydrolysis.}, subject = {Anorganische Chemie}, language = {de} }