Xanthine oxidase (XO) is an enzyme that catalyzes the oxidation of hypoxanthine to xanthine, and this one to uric acid. This process reduces molecular oxygen to O2⋅−. Hydroxyl free radicals and hydrogen peroxide, both of which are byproducts of XO activity, can caused oxidative stress in human cells. Overproduction of uric acid in the body leads to hyperuricemia, which is also linked with gout. Uric production in the body can be lowered by XO inhibitors. Inhibition of XO has also been proposed as a mechanism for improving cardiovascular health. Therefore, the search for new efficient XO inhibitors is an interesting topic in drug discovery.
3-Phenylcoumarins and 2-phenylbenzofurans are privileged scaffolds in Medicinal Chemistry. Their structural similarity makes them interesting molecules for a comparative work. Methoxy and nitro substituents were introduced in both scaffolds. A preliminary study gives some insights into the synthesis and biological activity of these molecules against this important target. In general, the studied 3-phenylcoumarins proved to be better XO inhibitors than the similarly substituted 2-phenylbenzofurans. Further studies are still needed to optimize the structure and increase the potential of these molecules as XO inhibitors for the treatment of gout.