UNC9994 hydrochloride is a functionally selective, β-arrestin-biased dopamine D2 receptor (D2R) agonist that selectively activates β-arrestin recruitment and signaling. UNC9994 hydrochloride shows a binding affinity with a Ki of 79 nM for D2R. UNC9994 hydrochloride is also an antagonist of Gi-regulated cAMP production and partial agonist for D2R/β-arrestin-2 interactions. UNC9994 hydrochloride shows antipsychotic-like activity[1].
UNC9994 hydrochloride induces D2-mediated β-arrestin-2 translocation with an EC50s of 6.1 nM and 448 nM in Tango assay and DiscoveRx assay, respectively[1].UNC9994 hydrochloride is an antagonist at 5HT2A and 5HT2B and an agonist at 5HT2C and 5HT1A[1].
UNC9994 (2.0 mg/kg; i.p.; once) hydrochloride shows antipsychotic activity that is attenuated in β-arrestin-2 knockout mice[1].
[1]. Allen JA, et al. Discovery of β-arrestin-biased dopamine D2 ligands for probing signal transduction pathways essential for antipsychotic efficacy. Proc Natl Acad Sci U S A. 2011 Nov 8;108(45):18488-93.