Synthesis and characterization of metal complexes of heterocyclic sulfonamide as carbonic anhydrase inhibitors.

Three novel metal complexes of N-[5-(aminosulfonyl)-1,3,4-thiadiazol-2-yl]-4-benzoyl-1-(3-nitrophenyl)-5-phenyl-1H-pyrazole-3-carboxamide which possess strong carbonic anhydrase (CA) inhibitory properties have been synthesised. The structure of these compounds has been investigated by elemental analysis, FT-IR, LC/MS, UV-vis spectrophotometric method and magnetic susceptibility. Human carbonic anhydrase isoenzymes hCA-I and hCA-II were purified from erythrocyte cells by the affinity chromatography. The inhibitory effects of newly synthesized complexes and acetazolamide (AAZ) as a control compound on hydratase and esterase activities of these isoenzymes have been studied in vitro by comparing IC(50) and K(i) values and it has been found that the newly synthesised complexes behave as very powerful inhibitors against hCA-I and hCA-II than parent ligand (1) and than AAZ.