- Structure-Activity Relationship, Pharmacological Characterization, and Molecular Modeling of Noncompetitive Inhibitors of the Betaine/γ-Aminobutyric Acid Transporter 1 (BGT1)
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N-(1-Benzyl-4-piperidinyl)-2,4-dichlorobenzamide 5 (BPDBA) is a noncompetitive inhibitor of the betaine/GABA transporter 1 (BGT1). We here report the synthesis and structure-activity relationship of 71 analogues. We identify 26m as a more soluble 2,4-Cl substituted 3-pyridine analogue with retained BGT1 activity and an improved off-target profile compared to 5. We performed radioligand-based uptake studies at chimeric constructs between BGT1 and GAT3, experiments with site-directed mutated transporters, and computational docking in a BGT1 homology model based on the newly determined X-ray crystal structure of the human serotonin transporter (hSERT). On the basis of these experiments, we propose a binding mode involving residues within TM10 in an allosteric site in BGT1 that corresponds to the allosteric binding pocket revealed by the hSERT crystal structure. Our study provides first insights into a proposed allosteric binding pocket in BGT1, which accommodates the binding site for a series of novel noncompetitive inhibitors.
- J?rgensen, Lars,Al-Khawaja, Anas,Kickinger, Stefanie,Vogensen, Stine B.,Skovgaard-Petersen, Jonas,Rosenthal, Emil,Borkar, Nrupa,L?ffler, Rebekka,Madsen, Karsten K.,Br?uner-Osborne, Hans,Schousboe, Arne,Ecker, Gerhard F.,Wellendorph, Petrine,Clausen, Rasmus P.
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supporting information
p. 8834 - 8846
(2017/11/14)
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- 18F-labeled benzamides for studying the dopamine D2 receptor with positron emission tomography
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Two series of (N-benzylpiperidin-4-yl)- and (9-azabicyclo[3.3.1]nonan- 3β-yl)benzamides were prepared, and in vitro binding assays were used to measure the affinity of these compounds for dopamine D2, dopamine D3, serotonin 5-HT2, and α2-adrenergic receptors. The results of these studies indicated compounds 23, 26b, and 34 have the selectivity needed for in vivo studies of the D2 (and possibly D3) receptors. 18F-Labeled analogues of 23, 26b and 34 were prepared by N-alkylation of the corresponding desbenzyl precursors with [18F]-4-fluorobenzyl iodide. Preliminary in vivo studies demonstrated that [18F]-23 and [18F]-26b are suitable candidates for further evaluation in positron emission tomography imaging studies. The slow rate of washout of [18F]-34 from nondopaminergic regions and its comparatively high lipophilicity indicates that this compound may not be suitable for imaging studies because of a high level of nonspecific binding.
- Mach,Leudtke,Unsworth,Boundy,Nowak,Scripko,Elder,Jackson,Hoffman,Evora,Rao,Molinoff,Childers,Ehrenkaufer
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p. 3707 - 3720
(2007/10/02)
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- Potential antipsychotic agents. 6. Synthesis and antidopaminergic properties of substituted N-(1-benzyl-4-piperidinyl)salicylamides and related compounds. QSAR based design of more active members
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A number of substituted 2-methoxybenzamides, with and without 6-hydroxy groups, with 4-piperidinyl side-chains have been synthesized and evaluated for their antidopaminergic properties. The salicylamides were found to require a lipophilic N-substituent, like a benzyl group, for high affinity for the dopamine D-2 binding site in contrast to salicylamides with 2-pyrrolodinylmethyl side-chains. Furthermore, the influence of the aromatic substituents on the activity in the 2 series, ie 4-piperidinyl and 2-pyrrolidinylmethyl side-chains, was different. This was supported by a Hansch analysis, which could accomodate both phenolic and non-phenolic benzamides with 1-benzyl-4-piperidinyl side-chains. The activity is primarily dictated by electronic features rather than by steric and lipophilic properties. The QSAR equations were validated by the design and synthesis of a new 10-fold more active derivative. The 2 classes of benzamides with different side-chains are suggested to act on different binding sites or on different subtypes of the dopamine D-2 receptor.
- De Paulis,Hall,Kumar,Ramsby,Ogren,Hogberg
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p. 507 - 517
(2007/10/02)
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