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

Abstract

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 IC₅₀ 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.

Keywords::

• Pyrazole
• sulfonamide
• carbonic anhydrase
• metal complexes
• acetazolamide