Carbonic anhydrase inhibitors: DNA cloning and inhibition studies of the alpha-carbonic anhydrase from Helicobacter pylori, a new target for developing sulfonamide and sulfamate gastric drugs

J Med Chem. 2006 Mar 23;49(6):2117-26. doi: 10.1021/jm0512600.


We have cloned and sequenced Helicobacter pylori alpha-class carbonic anhydrase (hpCA) from patients with different gastric mucosal lesions, including gastritis (n=15), ulcer (n=6), and cancer (n=16). Although several polymorphisms were newly identified such as 12Ala, 13Thr, 16Ile, and 168Phe, there was no significant relevance of any polymorphism with gastric mucosal lesion types. A library of sulfonamides/sulfamates has been investigated for the inhibition of hpCA, whereas new derivatives have been obtained by attaching 4-tert-butyl-phenylcarboxamido/sulfonamido tails to benzenesulfonamide/1,3,4-thiadiazole-2-sulfonamide scaffolds. All types of activity for inhibition of hpCA have been detected. Dorzolamide and simple 4-substituted benzenesulfonamides were weak inhibitors (KI 873-4360 nM). Sulfanilamide, orthanilamide, some of their derivatives, and indisulam showed better activity (KI 413-640 nM), whereas most of the clinically used inhibitors, such as methazolamide, ethoxzolamide, dichlorophenamide, brinzolamide, topiramate, zonisamide, etc., acted as medium-potency inhibitors (KI 105-378 nM). Some potent hpCA inhibitors were detected too (KI 12-84 nM) among acetazolamide, 4-amino-6-chloro-1,3-benzenedisulfonamide and some newly designed compounds incorporating lipophilic tails. Some of the newly prepared derivatives had selectivity ratios for inhibiting hpCA over hCA II in the range of 1.25-3.48, showing thus some selectivity for inhibiting the bacterial enzyme. Since hpCA is essential for the survival of the pathogen in acid, it might be used as a new pharmacologic tool in the management of drug-resistant H. pylori.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Carbonic Anhydrase Inhibitors / chemical synthesis*
  • Carbonic Anhydrase Inhibitors / chemistry
  • Carbonic Anhydrase Inhibitors / pharmacology
  • Carbonic Anhydrases / genetics*
  • Cloning, Molecular
  • DNA, Bacterial / genetics*
  • Gastric Mucosa / microbiology*
  • Gastritis / microbiology
  • Helicobacter pylori / enzymology*
  • Humans
  • Molecular Sequence Data
  • Polymorphism, Genetic
  • Stomach Neoplasms / microbiology
  • Stomach Ulcer / microbiology
  • Sulfonamides / chemical synthesis*
  • Sulfonamides / chemistry
  • Sulfonamides / pharmacology
  • Sulfonic Acids / chemical synthesis*
  • Sulfonic Acids / chemistry
  • Sulfonic Acids / pharmacology


  • Carbonic Anhydrase Inhibitors
  • DNA, Bacterial
  • Sulfonamides
  • Sulfonic Acids
  • sulfamic acid
  • Carbonic Anhydrases

Associated data

  • GENBANK/AB242859