Selective urokinase-type plasminogen activator inhibitors. 4. 1-(7-sulfonamidoisoquinolinyl)guanidines.

1-Isoquinolinylguanidines were previously disclosed as potent and selective inhibitors of urokinase-type plasminogen activator (uPA). Further investigation of this template has revealed that incorporation of a 7-sulfonamide group furnishes a new series of potent and highly selective uPA inhibitors. Potency and selectivity can be achieved with sulfonamides derived from a variety of amines and is further enhanced by the incorporation of sulfonamides derived from amino acids. The binding mode of these 1-isoquinolinylguanidines has been investigated by X-ray cocrystallization studies. uPA inhibitor 26 was selected for further evaluation based on its excellent enzyme potency (Ki 10 nM) and selectivity profile (4000-fold versus tPA and 2700-fold versus plasmin). In vitro, compound 26 is able to inhibit exogenous uPA in human chronic wound fluid (IC50 = 0.89 μM). In vivo, in a porcine acute excisional wound model, following topical delivery, compound 26 is able to penetrate into pig wounds and inhibit exogenous ...