9Th Brazilian Symposium on Medicinal Chemistry

Helicobacter pylori is a bacteria found in the digestive tract associated with diseases as chronic gastritis, gastric cancer and ulcer. Enzyme urease is essential for the survival of this bacteria, which hydrolyzes urea generating ammonia and carbon dioxide. Ammonia acts as receptor for H+ ions, making pH neutral and allowing H. pylori development. Chalcones are precursors of flavonoids, which have revealed a wide variety of biological properties. In this work, synthetic chalcones were investigated on urease and in H. pylori by spectrophotometric measurements. Four chalcones showed to be potential enzyme inhibitors but no significant results were found on bacteria. The chalcones that presented the best inhibitory potency were R8 and MS4Cl (IC50 25 and 29 μM). The study of docking consisted in investigating interactions between the inhibitor and active site of the enzyme. Our results evidenced conformations that chalcones can adopt to adequately stabilize within the active site of urease.