Design and discovery of urease and Helicobacter pylori inhibitors based on benzofuran/benzothiophene-sulfonate and sulfamate scaffolds for the treatment of ureolytic bacterial infections

Abstract

A series of sulfonate and sulfamate derivatives bearing benzofuran or benzothiophene scaffold exhibited potent inhibitory effect on urease enzyme. Most of the derivatives exhibited significantly higher potency than thiourea, the standard inhibitor. Compound 1s was identified as the most potent urease inhibitor with an IC50 value of 0.42 ± 0.08 μM, which is 53-fold more potent than thiourea, positive control (IC50 = 22.3 ± 0.031 μM). The docking results further revealed the binding interactions towards the urease active site. Phenotypic screening revealed that compounds 1c, 1d, 1e, 1f, 1j, 1n, and 1t exhibit high potency against H. pylori with MIC values ranging from 0.00625 to 0.05 mM and IC50 values ranging from 0.0031 to 0.0095 mM, much more potent than the positive control, acetohydroxamic acid (MIC and IC50 values were 12.5 and 7.38 mM, respectively). Additional studies were performed to investigate the toxicity of these compounds against the gastric epithelial cell line (AGS) and their selectivity profile against E. coli, and five Lactobacillus species representative of the gut microflora. Permeability characteristics of the most promising derivatives were investigated in Caco-2 cell line. The results indicate that the compounds could be targeted in the GIT only without systemic side effects.