Ureidobenzenesulfonamides as Selective Carbonic Anhydrase I, IX, and XII Inhibitors.

Sulfonamides remain an important class of drugs, especially because of their inhibitory effects on carbonic anhydrases. Herein, we have synthesized several sulfonamides and tested them for their inhibitory activity against carbonic anhydrases hCA I, hCA II, hCA IX, and hCA XII, respectively. Thereby, biphenyl- and benzylphenyl-substituted sulfonamides showed high selectivity against hCA IX and hCA XII; these enzymes are common targets in the treatment of hypoxic cancers, and noteworthy inhibitory activity was observed for several compounds toward hCA I that might be of interest for future applications to treat cerebral edema. Compound 3 (4-[3-(2-benzylphenyl)ureido]benzenesulfonamide) held an exceptionally low Ki value of 1.0 nM for hCA XII.