Synthesis of [[(naphthalenylmethoxy)- and -(quinolinylmethoxy)phenyl]amino]oxoalkanoic acid esters. A novel series of leukotriene D4 antagonists and 5-lipoxygenase inhibitors
A series of novel [[(naphthalenylmethoxy)- and (quinolinylmethoxy)phenyl]amino]oxoalkanoic acid esters have been prepared. These compounds were tested as inhibitors of rat polymorphonuclear leukocyte (PMN) 5-lipoxygenase (LO) in vitro and as inhibitors of ovalbumin (OA) and leukotriene D4 (LTD4) induced bronhcospasm in the guinea pig (GP) in vivo. Many naphthalenyl compounds were potent inhibitors of 5-LO, and several qunolinyl compounds were potent inhibitors of LTD4-mediated bronochospasms in the GP. The most potent naphthalenyl compound, 4-[[3-(2-naphthalenylmethoxy)phenyl]hydroxyamino]-4-oxobutanoic acid, methyl ester (6v), had an IC50 of 0.6 .mu.M in the 5-LO assay. The most potent compound in vivo, 4-[[3-(2-quinolinylmethoxy)phenyl]hydroxyamino]-4-oxobutanoic acid, methyl ester (6e), had ED50''s of 3.3 mg/kg and 27.4 mg/kg (intraduodenally) against LTD4- and OA-induced bronchospasm, respectively. When tested as an antagonist of LTD4-induced contraction of isolated GP tracheal spiral strips, 6e was shown to be a competitive inhibitor with a pKB value of 5.33.