- New systematically modified vesamicol analogs and their affinity and selectivity for the vesicular acetylcholine transporter - A critical examination of the lead structure
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To verify vesamicol as lead structure in the development of radioligands for imaging of VAChT in the brain by PET, we systematically modified this molecule and investigated four different groups of derivatives. Structural changes were conducted in all three ring systems A, B, and C resulting in a library of different vesamicol analogs. Based on their in vitro binding affinity toward VAChT as well as σ1 and σ2 receptors, we performed a structure-affinity relationship (SAR) study regarding both affinity and selectivity. The compounds possessed VAChT affinities in the range of 1.32 nM (benzovesamicol) to >10 mM and selectivity factors from 0.1 to 73 regarding σ1 and σ2 receptors, respectively. We could confirm the exceptional position of benzovesamicols as most affine VAChT ligands. However, we also observed that most of the compounds with high VAChT affinity demonstrated considerable affinity in particular to the σ1 receptor. Finally, none of the various vesamicol analogs in all four groups showed an in vitro binding profile suitable for specific VAChT imaging in the brain.
- Barthel, Claudia,Sorger, Dietlind,Deuther-Conrad, Winnie,Scheunemann, Matthias,Schweiger, Stephanie,J?ckel, Petra,Roghani, Ali,Steinbach, J?rg,Schüürmann, Gerrit,Sabri, Osama,Brust, Peter,Wenzel, Barbara
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- Hydrogen-bond-assisted epoxidation of homoallylic and allylic alcohols with hydrogen peroxide catalyzed by selenium-containing dinuclear peroxotungstate
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The reaction of peroxotungstates (H2WO4 + H 2O2) with H2SeO4 gave the novel seleniumcontaining dlnuclear tungsten species, (TBA)2[SeO 4{WO(O2)2}2] (I, TBA = [(n-C 4H9)4N]+), which was characterized by elemental analysis, IR, Raman, UV-vls, 77Se NMR, 183W NMR, and CSI-MS. Various kinds of homoallyllc and allyllc alcohols were efficiently epoxldlzed to the corresponding epoxy alcohols In high yields with 1 equlv. H2O2 with respect to thesubstrates. Compound I showed the highest catalytic activity for H 2O2-based epoxldatlon of homoallyllc and allyllc alcohols among selenium and tungsten complexes. The turnover frequency reachedup to 150 h-1 In a 10 mmol-scale epoxldatlon of c/s-3-hexen1 -ol and this value was the highest among those reported for the translt lon-metal catalyzed epoxldatlon of homoallyllc alcohols with H2O2. The kinetic, mechanistic, computational studies showed that the stabilization of the transition-state by the hydrogen bonding between I and the substrates results In the high reactivity for the l-catalyzed epoxldatlon of homoallyllc and allyllc alcohols. The nature of the hetero atoms In the dland tetranuclear peroxotungstates with XO 4n- ligands (X = As(V), P(V), S(VI), SI(IV), etc.) was crucial In controlling the Lewis acidity of the peroxotungstates, which significantly affects their electrophlllc oxygen transfer reactivity. Allthe data of the structural, kinetic, spectroscopic, and computational c omparison show that the dlmerlc peroxotungstate unit, {WO(O2)2} 2, In I Is activated by the SeO42- ligand.
- Kamata, Keigo,Hirano, Tomohisa,Kuzuya, Shinjiro,Mizuno, Noritaka
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scheme or table
p. 6997 - 7004
(2009/09/30)
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- Identification of (1S)-Phosphoryloxy-(2R,4S)-dihydroxycyclohexane as a Potent Inhibitor of Inositol Monophosphatase
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The 3,5,6-trisdeoxy derivative of myo-inositol 1-monophosphate, (1S)-phosphoryloxy-(2R,4S)-dihydroxycyclohexane , derived from the parent substrate by a strategy of hydroxy deletion, has been synthesised and shown to be the most potent inhibitor of inositol monophosphatase yet identified.
- Baker, Raymond,Leeson, Paul D.,Liverton, Nigel J.,Kulagowski, Janusz J.
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p. 462 - 464
(2007/10/02)
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- STEREOSELECTIVE EPOXIDATION OF ALLYLIC AND HOMOALLYLIC ALCOHOLS WITH 30percent HYDROGEN PEROXIDE CATALYZED BY TUNGSTIC ACID IN BUFFERED MEDIA
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The aqueous tungstic acid-catalyzed hydrogen peroxide epoxidation of allylic alcohols affords the same major diastereoisomer as the VO(acac)2/tBuOOH system with quite comparable stereoselectivities.In contrast, epoxidation of homoallylic alcohols appears to be much less stereoselective.
- Prat, Denis,Delpech, Bernard,Lett, Robert
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p. 711 - 714
(2007/10/02)
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- A PHOTOCHEMICAL SYNTHESIS OF βγ-EPOXYCYCLOHEXANONES
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The βγ-epoxycyclohexanones (1), (9) and (10) have been prepared by photolysis of the pyruvate esters derived from the corresponding epoxyalcohols.
- Carless, Howard A. J.,Fekarurhobo, G. K.
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p. 107 - 110
(2007/10/02)
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- OXIDATION OF ALCOHOLS WITH OXOPEROXOBIS-(N-PHENYLBENZOHYDROXAMATO)MOLYBDENUM(VI)
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The title complex oxidizes primary and secondary alcohols to the corresponding carbonyl compounds.Stereoselective epoxidation of allylic alcohols is also described.
- Tomioka, Hiroki,Takai, Kazuhiko,Oshima, Koichiro,Nozaki, Hitosi,Toriumi, Koshiro
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p. 4843 - 4846
(2007/10/02)
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