The designed group of compounds bound to CAIX, an anti-cancer target protein, via a triple binding model: (1) the sulfonamide group formed a coordination bond with the Zn(II) in the active site, (2) the hydrophobic ring selectively recognized CAIX over other CA isozymes, and (3) covalent bond formed between the compound and histidine residue of the protein. Here, CA9 is linked to cancer.