Design, Synthesis, and Structure−Affinity Relationships of Regioisomeric <i>N</i>-Benzyl Alkyl Ether Piperazine Derivatives as σ-1 Receptor Ligands
作者:Iman A. Moussa、Samuel D. Banister、Corinne Beinat、Nicolas Giboureau、Aaron J. Reynolds、Michael Kassiou
DOI:10.1021/jm100639f
日期:2010.8.26
A series of N-(benzofuran-2-ylmethyl)-N'-benzylpiperazines bearing alkyl or fluoroalkyl aryl ethers were synthesized and evaluated at various central nervous system receptors. Examination of in vitro sigma(1) [H-3](+)-pentazocinel and sigma(2) ([H-3]DTG) receptor binding profiles of piperazines 11-13 and 25-36 revealed several highly potent and sigma(1) selective ligands, notably, N-(benzofuran-2-ylmethyl)-N'-(4'-methoxybenzyl)piperazine (13, K-i = 2.7 nM, sigma(2)/sigma(1) = 38) and N-(benzofuran-2-ylmethyl)-N'-(4'-(2 ''-fluoroethoxy)benzyl)piperazine (30, K-i = 2.6 nM, sigma(2)/sigma(1) = 187). Structural features for optimal sigma(1) receptor affinity and selectivity over the 07 receptor were identified. On the basis of its favorable log D value, 13 was selected as a candidate for the development of a sigma(1) receptor positron emission tomography radiotracer. [C-11]13 showed high uptake in the brain and other a receptor-rich organs of a Papio hamadryas baboon. The in vivo evaluation of [C-11]13 indicates that this radiotracer is a suitable candidate for imaging the sigma(1) receptor in neurodegenerative processes.