Identification of selective inhibitors of Helicobacter pylori IMPDH as a targeted therapy for the infection

Helicobacter pylori (H. pylori), the major cause of several gastric disorders has been recognied as a type I carcinogen. By virtue of resistance developed by H. pylori strains, currently used antibiotic based treatments rather demonstrate high failure rates. Hence, there is an emerging need for identification of new targets to treat H. pylori infection. Inosine-5′-monophosphate dehydrogenase (IMPDH) has been studied as a potential target to treat H. pylori infection. Here, a detailed enzyme kinetic study of recombinant expressed H. pylori inosine-5′-monophosphate dehydrogenase (HpIMPDH) is presented. A new in-house synthesized indole-based scaffold is identified as an inhibitor for HpIMPDH. These indole-based compounds showed non-competitive inhibition against IMP and NAD⁺ whereas the benzimidazole compounds were found be uncompetitive inhibitors. The new indole scaffold ensures specificity due to its high selectivity for bacterial IMPDH over human IMPDH II. Our work aims to overcome the drawback of existing inhibitors by introducing new indole scaffold for targeting bacterial IMPDH.