Selective, competitive antagonist of BLT2 receptors (IC50 values are ~ 1 and > 10 μM at human recombinant BLT2 and BLT1 receptors respectively). Inhibits LTB4-induced contraction of lung parenchyma (pA2 = 7.2), and reduces LTB4-mediated airway obstruction in guinea pigs following i.v. and oral administration. Purity 98%. MW (observed): 360.46