Evaluation of N-phenyl homopiperazine analogs as potential dopamine D3 receptor selective ligands
作者:Aixiao Li、Yogesh Mishra、Maninder Malik、Qi Wang、Shihong Li、Michelle Taylor、David E. Reichert、Robert R. Luedtke、Robert H. Mach
DOI:10.1016/j.bmc.2013.03.074
日期:2013.6
A series of N-(2-methoxyphenyl) homopiperazine analogs was prepared and their affinities for dopamine D-2, D-3, and D-4 receptors were measured using competitive radioligand binding assays. Several ligands exhibited high binding affinity and selectivity for the D-3 dopamine receptor compared to the D-2 receptor subtype. Compounds 11a, 11b, 11c, 11f, 11j and 11k had Ki values ranging from 0.7 to 3.9 nM for the D-3 receptor with 30- to 170-fold selectivity for the D-3 versus D-2 receptor. Calculated log P values (logP = 2.6-3.6) are within the desired range for passive transport across the blood-brain barrier. When the binding and the intrinsic efficacy of these phenylhomopiperazines was compared to those of previously published phenylpiperazine analogues, it was found that (a) affinity at D-2 and D-3 dopamine receptors generally decreased, (b) the D-3 receptor binding selectivity (D-2:D-3 K-i value ratio) decreased and, (c) the intrinsic efficacy, measured using a forskolin-dependent adenylyl cyclase inhibition assay, generally increased. (C) 2013 Elsevier Ltd. All rights reserved.