PIT (2,2'-Pyridylisatogen tosylate) is a selective and non-competitive antagonist of P2Y1 receptor with an IC50 value of 0.14 μM for human P2Y1 receptor. PIT antagonizes P2Y1 receptor signaling without affecting nucleotide binding. PIT is an irreversible antagonist of responses to ATP at metabotropic purinoceptors (of the P2Y family) in some smooth muscles. PIT can be used for the research of chronic bronchitis and asthma.

MRS2279 diammonium is a selective and high affinity P2Y1 receptor antagonist, with a Ki value of 2.5 nM and an IC50 value of 51.6 nM. MRS2279 diammonium competitively inhibits ADP-promoted platelet aggregation with an pKb value of 8.05.

MRS4833 is a potent, selective antagonist of Gi protein-coupled P2Y14 receptor (P2Y14R, GPR105) with IC50 of 5.9 nM, Ki of 3.44 nM (human P2Y14R).

MRS4853 is a selective P2Y6 receptor (P2Y6R) antagonist with IC50 of 0.46 uM (hP2Y6R), displays weak affinity for mP2Y6R (IC50=6.15 uM).