1-Aryl-4-[(5-methoxy-1,2,3,4-tetrahydronaphthalen-1-yl)alkyl]piperazines and Their Analogues: Influence of the Stereochemistry of the Tetrahydronaphthalen-1-yl Nucleus on 5-HT<sub>1A</sub> Receptor Affinity and Selectivity versus α<sub>1</sub> and D<sub>2</sub> Receptors. 5
作者:Roberto Perrone、Francesco Berardi、Nicola A. Colabufo、Marcello Leopoldo、Vincenzo Tortorella
DOI:10.1021/jm980420n
日期:1999.2.1
Some 1-aryl-4-[(5-methoxy-1,2,3,4-tetrahydronaphthalen-1-yl)-n-propyl]piperazines and their alkylamino and alkylamido analogues, previously studied as 5-HT1A ligands, were prepared in enantiomerically pure form, and their absolute configuration was det;ermined by chemical correlation or by chiroptical properties. They were evaluated for in vitro 5-HT1A, D-2, and alpha(1) receptor affinity by radioligand binding assays, to study the influence of the chiral carbon atom of the tetrahydronaphthalene nucleus on the 5-HT1A affinity and selectivity. Results indicated that, as regarding the 5-HT1A receptor affinity, there was no difference in affinity between (-)- and (+)-enantiomers as well as the racemate of each compound. The stereochemistry, instead, influenced the selectivity: all (-)-enantiomers displayed affinity values higher than those of (+)-isomers at D-2 receptors, and conversely, all (+)-enantiomers displayed affinity values higher than those of (-)-isomers at alpha(1) receptors. As a result of this trend, it is not possible to predict the isomer with a better selectivity profile. However, compounds (S)-(+)-2, (S)-(+)-4, and (R)-(+)-6 displayed high affinity for the 5-HT1A receptor (IC50 values ranging between 7.0 and 2.3 nM) and good selectivity (greater than or equal to 250-fold) versus both D-2 and alpha(1) receptors. Furthermore, compounds (S)-(+)-4 and (R)-(-)-4 were submitted to the [S-35]GTP gamma S binding assay for a preliminary evaluation of their intrinsic activity on the 5-HT1A receptor.