@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{TackeWiesenberger1991, author = {Tacke, Reinhold and Wiesenberger, Frank}, title = {(Acetoxymethyl)methylphenylgerman: Synthese, thermisches Verhalten und olfaktorische Eigenschaften}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86927}, year = {1991}, abstract = {No abstract available.}, subject = {Chemische Synthese}, language = {de} } @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{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{TackeLangeBentlageetal.1983, author = {Tacke, Reinhold and Lange, Hartwig and Bentlage, Anke and Sheldrick, William S. and Ernst, Ludger}, title = {2.2.5.5-Tetraorganyl-1.4-dioxa-2.5-disilacyclohexane/2,2,5,5-Tetraorganyl-1,4-dioxa-2,5-disilacyclohexanes}, series = {Zeitschrift f{\"u}r Naturforschung B}, volume = {38}, journal = {Zeitschrift f{\"u}r Naturforschung B}, number = {2}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-128423}, pages = {190-193}, year = {1983}, abstract = {The 2,2,5,5-tetraorganyl-1,4-dioxa-2,5-disilacyclohexanes 2a-2c were prepared by condensation of the corresponding (hydroxymethyl)diorganylsilanes 1 a-1 c. The constitution of the heterocycles was confirmed by elemental analyses, cryoscopic measurements, mass spectrometry, and NMR-spectroscopic \((^1H, ^{13}C)\) investigations. The molecular structure of 2 b was determined by X-ray diffraction analysis.}, language = {de} } @article{WieseTackeWannagat1981, author = {Wiese, D. and Tacke, Reinhold and Wannagat, U.}, title = {9,9-Dimethyl-10-(3-dimethylaminopropyl)-9-silaacridan, ein Sila-Analogon des Dimetacrins, und strukturverwandte Verbindungen}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63691}, year = {1981}, abstract = {Das Sila-Dimetacrin (3a), ein Sila-Analogon des Psychopharmakons Dimetacrin (2), und sein N,N-Diethylderivat 3 b sowie sein 3-Chlorderivat 3 c wurden, von den o-Halogenanilinen 4 a- c ausgehend, {\"u}ber die teilweise unbekannten Stufen 5 a- c bis 10a- d synthetisiert, in ihren Eigenschaften beschrieben und in ihrer Struktur {\"u}ber Elementaranalysen, \(^1\)H-NMR- und Massenspektren sichergestellt. Die Synthese des Zwischenproduktes Bis(2-bromphenyl)amin (9a) konnte optimiert werden.}, subject = {Anorganische Chemie}, language = {de} } @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{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{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{WaelbroeckCamusTastenoyetal.1991, author = {Waelbroeck, M. and Camus, J. and Tastenoy, M. and Mutschler, E. and Strohmann, C. and Tacke, Reinhold and Lambrecht, G. and Christophe, J.}, title = {Binding affinities of hexahydro-difenidol and hexahydro-sila-difenidol analogues at four muscarinic receptor subtypes: constitutional and stereochemical aspects}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64128}, year = {1991}, abstract = {Hexahydro-sila-difenidoJ and eight analogues behaved as simple cumpetitive inhibitors of eHJN·methyl·scopoJamine binding to homogenates frorn human neuroblastoma NB-OK 1 cells (M\(_1\) sites), rat heart (M\(_2\) sites), rat pancreas (M\(_3\) sites), and rat striatum 'B' sites (M\(_4\) sites). Pyrrolidino- and hexamethyleneimino analogues showed the same sekctivity profile as the parent compound. Hexahydro-sila-difenidol methiodide and the methiodide of p-fluoro-hexahydro·sila-difenidol had a f{\"u}gher affinity but a lower selectivity than the tertiary amines. Compounds containing a p·methoxy, p-chJoro or p-fluoro substituent in the phenyl ring of hexahydro-sila-difenidol showed a qualitative)y similar selectivity profile as the parent compound (i.e., M\(_1\)= M\(_3\) = M\(_4\) >M\(_2\) ), but up to 16-fold lower affinities. o-Methoxy-hexahydro-sila-difenidol has a lower affinity than hexahydro-sila-difeni.:!o! at the four binding sites. lts selectivity profile (M\(_4\) > M\(_1\), M\(_3\) > M\(_2\) ) was different from hexahydro-sila-difenidol. Replacement of the centrat silicon atom of hexahydro-sila-difenidol, p-fluoro-hexahydro-sila-difenidol and thdr quatemary (N-methylated) analogues by a carbon atom did not change their binding affinities significantly. The iour muscarinic receptors showed a higher affinity for the (R)- than for the (S)-enantiomers of hexahydro-difenidol, p-fluorohexahydro-difenidol and their methiodides. The stereoselectivity varied depending on the receptor subtype and drug considered.}, 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} } @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{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{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{TackeSperlichBecker1994, author = {Tacke, Reinhold and Sperlich, J. and Becker, B.}, title = {Bis[2,3-naphthalenediolato(2-)](pyrrolidinio-methyl)germanate-tetartoacetonitrile, the first zwitterionic \(\lambda_5\)-germanate: synthesis and crystal structure analysis}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64329}, year = {1994}, abstract = {The zwitterionic spirocyclic \(\lambda_5\)-germanate bis(2,3-naphthalenediolato( 2-)](pyrrolidiniomethyl)germanate (8) was synthesized and the crystal structure of its tetartoacetonitrile solvate 8 · 1/4 CH\(_3\)CN studied by single-crystal X-ray diffraction. Compound 8 was prepared by reaction of (MeO)\(_3\)GeCH\(_2\)NC\(_4\)H\(_8\) (11; NC\(_4\)H\(_8\) = pyrrolidino) with two equivalents of 2,3-naphthalenediol (isolated as 8 · 1/4 CH\(_3\)CN; yield 92\%). The coordination polyhedron around the pentacoordi- naphthalenediolatonate germanium atom of 8 · 1/4 CH\(_3\)CN can be described as a strongly distorted trigonal bipyramid (the structure is displaced by 38.9\% from the ideal trigonal bipyrarnid towards the ideal square pyramid), the carbon atom occupying an equatorial position. In the crystal lattice of 8 · 1/4 CH\(_3\)CN, the zwitterions form intermolecular N-H ... o hydrogen bonds leading to the formation of dimers. 1H- and \(^{13}\C-NMR studies revealed that 8 also exists in solution ([D\(_6\)]DMSO).}, subject = {Anorganische Chemie}, language = {en} } @article{TackeSperlichStrohmannetal.1992, author = {Tacke, Reinhold and Sperlich, J{\"o}rg and Strohmann, Carsten and Frank, Brigitta and Mattern, G{\"u}nter}, title = {Bis[3,4,5,6-tetrabrom-1,2-benzoldiolato(2-)]-(pyrrolidiniomethyl)silicat-Acetonitril-Solvat [(C6Br4O2)2SiCH2(H)NC4H8 · CH3CN]: Synthese sowie Kristall- und Molek{\"u}lstruktur eines zwitterionischen [lambda]5-Spirosilicats}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86884}, year = {1992}, abstract = {Single crystal X-ray studies on bis[3,4,5,6-tetrabromo-1 ,2-benzenediolato(2- )](pyrrolidiniomethyl)silicate acetonitrile solvate [(C6Br40 2hSiCH2(H)NC4H8 · CH3CN; monoclinic, P2t/c, a = 808.5(4), b = 1533.0(8), c = 2212.6(1) pm, ß = 97.67(2)0 , Z = 4] revealed a zwitterionic structure with a pentacoordinate, formally negatively charged silicon atom and a positively charged ammonium moiety. The silicon atom is surrounded by four oxygen atoms and one carbon atom in a trigonalbipyramidal fashion, with the carbon atom in an equatorial position. The structure is displaced by 7.0\% from the trigonal bipyramid towards the square pyramid. The zwitterion and the CH3CN molecule form intermolecular N-H · · · N hydrogen bonds.}, subject = {Kristallstruktur}, language = {de} } @article{TackeMuehleisen1994, author = {Tacke, Reinhold and M{\"u}hleisen, M.}, title = {Bis[benzilato(2-)-O\(^1\),O\(^2\)][2-(dimethylammonio)ethoxy]silicate: synthesis and structural characterization of a zwitterionic \(\lambda^5\)Si-silicate with a SiO\(_5\) framework}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64400}, year = {1994}, abstract = {No abstract available}, subject = {Anorganische Chemie}, language = {en} } @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{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{TackeStreckerNiedner1981, author = {Tacke, Reinhold and Strecker, M. and Niedner, R.}, title = {Cholinesterase-hemmende Organophosphors{\"a}ureester und ihre Sila-Analoga}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63689}, year = {1981}, abstract = {Die Organophosphors{\"a}ureester la-4a und ihre Sila-Analoga lb-4b des Typs R\(^1\)R\(^2\)P(O)( p-OC\(_6\)H\(_4\)ElMe\(_3\)) (EI = C, Si) wurden synthetisiert. Die Kohlenstoff-Verbindungen 1 a- 4a zeigen hinsichtlich ihrer Anticholinesterase-Aktivit{\"a}t die gleichen Struktur-Wirkungs-Beziehungen wie die Silicium-Verbindungen 1 b- 4 b. Letztere sind jeweils wirksamer als die entsprechenden C-Analoga.}, subject = {Anorganische Chemie}, language = {de} }