Novel aromatic/heterocyclic sulfonamides and their metal complexes as inhibitors of carbonic anhydrase isozymes I, II and IV.

Reaction of five aromatic/heterocyclic sulfonamides containing free amino, groups with 5-nitro-alpha-2-toluenesultone and diethyl pyrocarbonate, respectively, afforded novel inhibitors of the zinc enzyme carbonic anhydrase (CA). Zn(II) complexes of the new sulfonamides were prepared. Excellent inhibition of three CA isozymes (CA I, II and IV respectively) were observed with some of the new sulfonamides, but especially with their Zn(II) complexes. Structure-activity correlations in this series of inhibitors are discussed.