Design, synthesis and antitumor activity evaluation of novel indole acrylamide derivatives as IMPDH inhibitors

Inosine 5'-monophosphate dehydrogenase (IMPDH; EC1.1.1.205) is the rate-limiting enzyme of GMP biosynthesis. The inhibition of IMPDH limits the growth and survival of tumors. Based on the systematic summary of clinical IMPDH inhibitors, 38 acrylamide derivatives with differently substituted indoles at the 3-position as the core scaffold were designed and synthesized. In addition, the actions of these compounds at the enzyme and cellular levels were evaluated. An MTT assay with different kinds of cells was used to assess the cytotoxic activities of compounds 14e and 14n, which displayed potent hIMPDH2 inhibitory activities (IC₅₀ = 4.207 and 2.948 μM, respectively). Biological evaluation indicated that target compounds 14e and 14n displayed the most significant effects on SW480 human colon cancer cells (IC₅₀ = 15.34 ± 0.06 and 15.31 ± 0.09 μM, respectively), and it was determined that these compounds are effective and valuable IMPDH inhibitors for cancer intervention.