Purinergic receptor antagonist that potently inhibits P2Y11 receptor activity (IC50 = 463 nM). Displays selectivity for P2Y11 and P2X1 receptors over P2Y1, P2Y2 , P2X2, P2X3, P2X4 and P2X7 receptors. Inhibits NAD+-induced activation of human granulocytes.