Fused tricyclic pyrrolizinones that exhibit pseudo-irreversible blockade of the NK1 receptor
作者:Gregori J. Morriello、Gary Chicchi、Tricia Johnson、Sander G. Mills、Julie DeMartino、Marc Kurtz、K.L.C. Tsao、Song Zheng、Xinchun Tong、Emma Carlson、Karen Townson、Alan Wheeldon、Susan Boyce、Neil Collinson、Nadia Rupniak、Robert J. DeVita
DOI:10.1016/j.bmcl.2010.07.058
日期:2010.10
Previously, we had disclosed a novel class of hNK(1) antagonists based on the 5,5-fused pyrrolidine core. These compounds displayed subnanomolar hNK(1) affinity along with good efficacy in a gerbil foot-tapping (GFT) model, but unfortunately they had low to moderate functional antagonist (IP-1) activity. To elaborate on the SAR of this class of hNK(1) compounds and to improve functional activity, we have designed and synthesized a new class of hNK(1) antagonist with a third fused ring. Compared to the 5,5-fused pyrrolidine class, these 5,5,5-fused tricyclic hNK(1) antagonists maintain subnanomolar hNK(1) binding affinity with highly improved functional IP-1 activity (< 10% SP remaining). A fused tricyclic methyl, hydroxyl geminally substituted pyrrolizinone (compound 20) had excellent functional IP (< 2% SP remaining), hNK(1) binding affinity, off-target selectivity, pharmacokinetic profile and in vivo activity. Complete inhibition of agonist activity was observed at both 0 and 24 h in the gerbil foot-tapping model with an ID50 of 0.02 mpk at both 0 and 24 h, respectively. (C) 2010 Elsevier Ltd. All rights reserved.