Synthesis, structure-activity relationships, and mechanistic studies of 5-arylazo-tropolone derivatives as novel xanthine oxidase (XO) inhibitors.

Xanthine oxidase (XO) is an enzyme that contains molybdenum at the active site and catalyzes the oxidation of purine bases to uric acid. Even though XO inhibitors are widely used for the treatment of hyperuricemia and gout, only very few such compounds are clinically used as drugs for the treatment of these diseases. Given the unique physicochemical properties of tropolone, i.