Synthesis and evaluation of indolinyl- and indolylphenylacetylenes as PET imaging agents for β-amyloid plaques
作者:Wenchao Qu、Seok-Rye Choi、Catherine Hou、Zhiping Zhuang、Shunichi Oya、Wei Zhang、Mei-Ping Kung、Rajesh Manchandra、Daniel M. Skovronsky、Hank F. Kung
DOI:10.1016/j.bmcl.2008.07.077
日期:2008.9
Two new phenylacetylene derivatives, 5-((4-(2-(2-(2-fluoroethoxy)ethoxy)ethoxy)phenyl)ethynyl)indoline 8 and 5-((4-(2-(2-(2-fluoroethoxy)ethoxy)ethoxy)phenyl)ethynyl)-1H-indole 14, targeting beta-amyloid ( Ab) plaques have been prepared. In vitro binding carried out in tissue homogenates prepared from postmortem AD brains with [(125)[] IMPY (6-iodo-2-(40-dimethylamino-phenyl-imidazo[1,2-a]pyridine) as the radioligand indicated good binding affinities (K-i = 4.0 and 1.5 nM for 8 and 14, respectively). Brain penetration of the corresponding radiofluorinated ligands, evaluated in the normal mice, showed good initial brain penetration (4.50 and 2.43% ID/g (injected dose/gram) for [F-18]8 and [F-18]14 at 2 min after injection) with moderate to low washout rates from the brain (1.71% ID/g at 2h and 2.10% ID/g at 3 h, respectively). Autoradiography and homogenate binding studies demonstrated the high specific binding of [F-18]14 to the Ab plaques; however, [F-18]8 showed low specific binding. These preliminary results identified that indolylphenylacetylene, 14, may be a good lead for further structural modi. cation to develop a useful Ab plaque imaging agent. (C) 2008 Elsevier Ltd. All rights reserved.