文摘
Negative modulators of metabotropic glutamate 2 & 3 receptors demonstrate antidepressant-like activity in animal models and hold promise as novel therapeutic agents for the treatment of major depressive disorder. Herein we describe our efforts to prepare and optimize a series of conformationally constrained 3,4-disubstituted bicyclo[3.1.0]hexane glutamic acid analogs as orthosteric (glutamate site) mGlu2/3 receptor antagonists. This work led to the discovery of a highly potent and efficacious tool compound 18 (hmGlu2 IC50 46 ± 14.2 nM, hmGlu3 IC50 = 46.1 ± 36.2 nM). Compound 18 showed activity in the mouse forced swim test with a minimal effective dose (MED) of 1 mg/kg ip. While in rat EEG studies it exhibited wake promoting effects at 3 and 10 mg/kg ip without any significant effects on locomotor activity. Compound 18 thus represents a novel tool molecule for studying the impact of blocking mGlu2/3 receptors both in vitro and in vivo.