Development of Bicyclo[3.1.0]hexane-based A<sub>3</sub> Receptor Ligands – Closing the Gaps in the Structure-affinity Relationships

In this paper, a series of bicyclo[3.1.0]hexane-based nucleosides were synthesized and evaluated for their P1 receptor affinities in radioligand binding studies. The most potent derivative 30 displayed moderate A3AR affinity (Ki of 0.38 μM) and high A3R selectivity. A subset of compounds varied at 5’-position was further evaluated in functional P2Y1R assays displaying no off-target activity.