Synthesis and investigation of inhibition effects of new carbonic anhydrase inhibitors.

Three new derivatives of 2-substituted 1,3,4-thiadiazole-5-sulfonamide have been synthesized. These compounds are 2-(3-chloropropionylamino)-1,3,4-thiadiazole-5-sulfonamide (1); 2-(2,2-dichloroacetylamino)-1,3,4-thiadiazole-5-sulfonamide (2); and 2-(3-phenylpropionylamino)-1,3,4-thiadiazole-5-sulfonamide (3). Inhibition effects of these compounds on carbonic anhydrase I and II have been investigated. By comparing I50 and Ki values of the compounds, it has been found that compound 1 is a more potent inhibitor than acetazolamide (b) on carbonic anhydrase II.