Discovery of novel benzimidazole derivatives as potent potassium-competitive acid blockers for the treatment of acid-related diseases.

ABSTRACT

H+, K+-ATPase, as the most critical enzyme in gastric acid secretion, has long been an attractive target for the treatment of acid-related diseases. In this study, a series of benzimidazole derivatives were designed and synthesized through conformational restriction and skeleton hopping strategies by using vonoprazan as the lead compound. Among them, compounds A12 (IC50 = 9.32 µM) and A18 (IC50 = 5.83 µM) showed better inhibition at the enzyme level. In addition, gastric acid secretion inhibition was assessed in vivo, and the results showed that A12 and A18 significantly inhibited basal gastric acid secretion, 2-deoxy-d-glucose (2DG) stimulated gastric acid secretion and histamine-stimulated gastric acid secretion. In further in vitro metabolic experiments, A12 and A18 demonstrated excellent stability and low toxicity. Pharmacokinetic studies showed that the p.o. and i.v. half-lives of A18 were 3.21 h and 8.67 ± 1.15 h, respectively. In summary, A18 might be a novel and effective potassium-competitive acid blocker, and this study provides strong support for it use in the treatment of acid-related diseases.