Structure-Activity Relationship of Omeprazole and Analogs as Helicobacter pylori Urease Inhibitors
摘要:
Helicobacter pylori urease belongs to a family of highly conserved urea-hydrolyzing enzymes. A common feature of these enzymes is the presence of two Lewis acid nickel ions and a reactive cysteine residue in the active site. The H+/K(+)-ATPase inhibitor omeprazole is a prodrug of a sulfenamide which covalently modifies cysteine residues on the luminal side of the H+/K(+)-ATPase of gastric parietal cells. Omeprazole and eight analogues were selected based on their chemical, electronic, and kinetic properties, and each was incubated with viable H. pylori in phosphate-buffered saline at pH 7.4 for 30 min, after which 100 mM urea was added and the amount of ammonia formed analyzed after a further 10 min. Inhibition between 0% and 100% at a 0.1 mM concentration was observed for the different analogues and could be expressed as a function of the pKa-value of the pyridine, the pKa-value of the benzimidazole, the overall lipophilicity, and, most importantly, the rate of sulfenamide formation, in a quantitative structure-activity relationship. The inhibition was potentiated by a lower pH (favoring the formation of the sulfenamide) but abolished in the presence of beta-mercaptoethanol (a scavenger of the sulfenamide). Structural analogues incapable of yielding the sulfenamide did not inhibit ammonia production. Treatment of Helicobacter felis-infected mice with 230 mumol/kg flurofamide b.i.d. for 4 weeks, known to potently inhibit urease activity in vivo, as a means of eradicating the infection, was tested and compared with the effect of 125 mumol/kg omeprazole b.i.d. for 4 weeks. Neither treatment proved efficacious.
[EN] ARYL HYDROCARBON RECEPTOR LIGANDS AND THEIR ANALOGUES FOR THE PREVENTION AND TREATMENT OF INFLAMMATORY DISORDERS [FR] LIGANDS DU RÉCEPTEUR D'ARYL-HYDROCARBONÉ ET LEURS ANALOGUES POUR LA PRÉVENTION ET LE TRAITEMENT DE TROUBLES INFLAMMATOIRES
Helicobacter pylori eradicating agent having inhibitory activity on gastric acid secretion
申请人:Ito Masaharu
公开号:US08778975B2
公开(公告)日:2014-07-15
Disclosed are: a compound which is stable in an acid, has an antibacterial effect against a bacterium Helicobacter pylori, can exert a satisfactory level of an antibacterial effect when used singly, does not affect an enteric bacterium, has an antibacterial effect against a bacterium resistant to an antibacterial agent, and has an inhibitory effect on gastric acid secretion; and a pharmaceutical composition comprising the compound. Specifically disclosed are: a compound represented by the general formula (I) or a salt thereof; and a pharmaceutical composition comprising the compound or the salt thereof:
wherein R represents a linear alkyl group having 4 to 8 carbon atoms, preferably 5 to 7 carbon atoms.