Conformationally-flexible benzamide analogues as dopamine D3 and σ2 receptor ligands
作者:Robert H Mach、Yunsheng Huang、Rebekah A Freeman、Li Wu、Suwanna Vangveravong、Robert R Luedtke
DOI:10.1016/j.bmcl.2003.09.083
日期:2004.1
A series of conformationally-flexible analogues was prepared and their affinities for D2-like dopamine(D-2, D-3 and D-4) were determined using in vitro radioligand binding assays. The results of this structure-activity relationship study identified one compound, 15, that bound with high affinity (K-i value = 2 nM) and moderate selectivity (30-fold) for D-3 compared to D-2 receptors. In addition, this series of compounds were also tested for affinity at sigma(1) and sigma(2) receptors. We evaluated the affinity of these dopaminergic compounds at sigma receptors because (a) several antipsychotic drugs, which are high affinity antagonists at dopamine D2-like receptors, also bind to sigma receptors and (b) sigma receptors are expressed ubiquitously and at high levels (picomoles per mg proteins). It was observed that a number of analogues displayed high affinity and excellent selectivity for sigma(2) versus sigma(1) receptors. Consequently, these novel compounds may be useful for characterizing the functional role of sigma(2) receptors and for imaging the sigma(2) receptor status of tumors in vivo with PET. (C) 2003 Elsevier Ltd. All rights reserved.