Three new aromatic sulfonamide inhibitors of carbonic anhydrases I, II, IV and XII

4-Sulfamoyl-N-(3-morpholinopropyl)benzamide (I-1), N-(3-morpholinopropyl)benzene-1,4-disulfonamide (I-2) and N-(4-diethylaminoethoxybenzyl)benzene-1,4-bis(sulfonamide (I-3), were prepared and assayed as inhibitors of four carbonic anhydrase (CA) isoenzymes hCA I, hCA II, hCA IV and hCA XII. These compounds exhibited nanomolar half maximal inhibitory concentration (IC50) ranging from 58 to 740 nmol/L. All three aromatic sulfonamides show different activities for the isoenzymes studied with lowest affinity against isoenzyme hCA XII.