α,β-Methylene ATP dilithium, a phosphonic analog of ATP, serves as a ligand for P2X3 and P2X7 receptors. It is a potent agonist specifically targeting P2X1 and P2X3 receptors while exerting negligible activity on P2X2, P2X4, P2X5, P2X6, and P2X7 receptors.

α,β-Methylene ATP trisodium, a phosphonate analog of ATP, is a selective P2X agonist that induces enhanced contraction of UBSM. α,β-Methylene ATP trisodium inhibits P2X1 and P2X3, but is inactive against P2X2, 4 and 7.