Sulfonamide derivatives with benzothiazole scaffold: Synthesis and carbonic anhydrase I–II inhibition properties

The secondary sulfonamide derivatives containing benzothiazole scaffold (1–10) were synthesized to determine their inhibition properties on two physiologically essential human carbonic anhydrases isoforms (hCAs, EC, 4.2.1.1), hCA I, and hCA II. The inhibitory effects of the compounds on hCA I and hCA II isoenzymes were investigated by comparing their IC50 and Ki values. The Ki values of compounds (1–10) against hCA I and hCA II are in the range of 0.052 ± 0.022–0.971 ± 0.280 and 0.025 ± 0.010–0.682 ± 0.335, respectively. Some of these inhibited the enzyme more effectively than the standard drug, acetazolamide. In particular, compounds 5 and 4 were found to be most effective on hCA I and hCA II.