Carbonic anhydrase inhibitors. inhibition of cytosolic isozyme XIII with aromatic and heterocyclic sulfonamides: a novel target for the drug design

• Published in: Bioorganic & medicinal chemistry letters Vol. 14; no. 14; pp. 3757 - 3762
• Main Authors: LEHTONEN, Jonna M, PARKKILA, Seppo, VULLO, Daniela, CASINI, Angela, SCOZZAFAVA, Andrea, SUPURAN, Claudiu T
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier 16.07.2004
• Subjects: Amino Acid Sequence; Animals; Biological and medical sciences; Carbonic Anhydrase Inhibitors - chemical synthesis; Carbonic Anhydrase Inhibitors - pharmacology; Cytosol - enzymology; Drug Design; Humans; Hydrogen-Ion Concentration; Isoenzymes - antagonists & inhibitors; Isoenzymes - metabolism; Kinetics; Medical sciences; Miscellaneous; Molecular Sequence Data; Neoplasms - enzymology; Pharmacology. Drug treatments; Rats; Structure-Activity Relationship; Sulfonamides - chemical synthesis; Sulfonamides - pharmacology; Methazolamide; Sulfonamide; Enzyme; Isozyme; Dorzolamide; Acetazolamide; Enzyme inhibitor; Lyases; Valdecoxib; In vitro; Sulfanilamide; Tissue; Structure activity relation; Carbonate dehydratase; Aromatic compound; Chemical synthesis; Carbon-oxygen lyases; Heterocyclic compound; Halogen Organic compounds; Hydro-lyases
• ISSN: 0960-894X; 1464-3405
• DOI: 10.1016/j.bmcl.2004.04.106

The inhibition of the newly discovered cytosolic carbonic anhydrase isozyme XIII (CA XIII) has been investigated with a series of aromatic and heterocyclic sulfonamides, including some of the clinically used derivatives, such as acetazolamide, methazolamide, dichlorophenamide, dorzolamide, and valdecoxib. Inhibition data for the physiologically relevant isozymes I and II (cytosolic forms) and the tumor associated isozyme IX (transmembrane) were also provided for comparison. A very interesting and unusual inhibition profile against CA XIII with these sulfonamides has been observed. The clinically used compounds (except valdecoxib, which was a weak CA XIII inhibitor) potently inhibit CA XIII, with Ki's in the range of 17-23 nM, whereas sulfanilamide, halogenated sulfanilamides, homosulfanilamide, 4-aminoethylbenzenesulfonamide, and orthanilamide were slightly less effective, with Ki's in the range of 32-56 nM. Several low nanomolar (Ki's in the range of 1.3-2.4 nM) CA XIII inhibitors have also been detected, all of them belonging to the sulfanilyl-sulfonamide type of inhibitors, of which aminobenzolamide is the best known representative. Because CA XIII is an active isozyme predominantly expressed in salivary glands, kidney, brain, lung, gut, uterus, and testis, where it probably plays an important role in pH regulation, its inhibition by sulfonamides may lead to novel therapeutic applications for this class of pharmacological agents.