Re-exploring the N-phenylpicolinamide derivatives to develop mGlu4 ligands with improved affinity and in vitro microsomal stability
作者:Zhaoda Zhang、Kun-Eek Kil、Pekka Poutiainen、Ji-Kyung Choi、Hye-Jin Kang、Xi-Ping Huang、Bryan L. Roth、Anna-Liisa Brownell
DOI:10.1016/j.bmcl.2015.07.031
日期:2015.9
In recent years, mGlu(4) has received great attention and research effort because of the potential benefits of mGlu(4) activation in treating numerous brain disorders, such as Parkinson's disease (PD). Many positive allosteric modulators of mGlu(4) have been developed. To better understand the role of mGlu(4) in healthy and disease conditions, we are interested in developing an mGlu(4) selective radioligand for in vivo studies. Thus, we had synthesized and studied [C-11]2 as a PET tracer for mGlu(4), which demonstrated some promising features as a PET radioligand as well as the limitation need to be improved. In order to develop an mGlu(4) ligand with enhanced affinity and improved metabolic stability, we have modified, synthesized and evaluated a series of new N-phenylpicolinamide derivatives. The SAR study has discovered a number of compounds with low nM affinity to mGlu(4). The dideuteriumfluoromethoxy modified compound 24 is identified as a very promising mGlu(4) ligand, which has demonstrated enhanced affinity, improved in vitro microsomal stability, good selectivity and good permeability. (C) 2015 Elsevier Ltd. All rights reserved.