Recent Advances in the Design and Synthesis of Small Molecule Carbonic Anhydrase IX Inhibitors

Human carbonic anhydrase (CA) IX is a tumor-associated protein since it is scarcely present in normal tissues but highly overexpressed in a large number of solid tumors, where it actively contributes to survival and metastatic spread of tumor cells. A variety of approaches and design strategies were reported that afford CA IX/XII specific inhibitors and avoid the compromising effects of isoforms-promiscuous compounds. CA IX inhibitors hybrids/conjugates have become an important scaffold to design therapeutic agents with both CA inhibition and anti-cancer effects. In this review, we firstly present an overview of the role of CA IX in hypoxic tumors physiopathology, then provide a comprehensive update on the rational design and synthesis of small molecule CA IX inhibitors discovered since 2019. Also, their structure-activity relationship analysis studies are covered. A brief description of applications for CA IX inhibition in other therapeutic areas is also provided.