)OCTYL]OXY]-2-PYRIDINYL]METHYL]THIO]METHYL]BENZOIC ACID AND RELATED-COMPOUNDS - HIGH-AFFINITY LEUKOTRIENE B-4 RECEPTOR ANTAGONISTS

)octyl]oxy]-2-pyridinyl]methyl]thio]methyl]benzoic acid (11, SB 201993 ) is a novel, potent LTB(4) receptor antagonist. Compound 11 arose fro m a structure-activity study of a series of trisubstituted pyridines t hat demonstrated LTB(4) receptor antagonist activity. The placement of an additional methylene unit in the sulfur containing chain linking t he pyridine and benzoic acid moieties of lead compound 8(K-i=80 nM) re sulted in a greater than 10-fold increase in receptor affinity. Additi onally, in this new series of compounds, the oxidation state of the su lfur was found to be critical to the activity, i.e., the sulfoxide and sulfone showed substantially lower affinity for the LTB(4) receptor. Compound 11 competitively inhibits the binding of [H-3]LTB(4) to LTB(4 ) receptors on human polymorphonuclear leukocutes with a K-i of 7.1 nM and blocks both the LTB(4)-induced calcium mobilization and the LTB(4 )-induced degranulation responses in these cells with IC50 values of 1 31 and 271 nM, respectively. Compound 11 demonstrated oral LTB(4) anta gonist activity as well as topical antiinflammatory activity in the mo use.