81864-39-3Relevant academic research and scientific papers
Structure-activity relationship of omeprazole and analogues as Helicobacter pylori urease inhibitors
Kuhler,Fryklund,Bergman,Weilitz,Lee,Larsson
, p. 4906 - 4916 (2007/10/03)
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 pK(a)-value of the pyridine, the pK(a)-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 β- 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 μmol/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 μmol/kg omeprazole b.i.d. for 4 weeks. Neither treatment proved efficacious.
Imidazole derivatives
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, (2008/06/13)
Tricyclic imidazole derivatives of the formula STR1 wherein R1 is 2-pyridyl optionally substituted by lower alkyl or lower alkoxy, n is the integer 0 or 1, R2 is hydrogen or lower alkyl, R3 and R4, independently, are hydrogen or lower alkyl, A is a group of the formula STR2 m is the integer 2 or 3, R5, R6, R7 and R8, independently, are hydrogen or lower alkyl, and R9 is hydrogen and R10 is hydrogen or lower alkyl or R9 and R10 taken together are oxo, provided that at least one of R3 and R4 is lower alkyl when A is a group of the formula and their pharmaceutically acceptable acid addition salts. The compounds of formula I inhibit gastric acid secretion and prevent the formation of gastric ulcers.
