Design, synthesis, and evaluation of different scaffold derivatives against NS2B-NS3 protease of dengue virus

The number of deaths or critical health issues is a threat in the infection caused by Dengue virus, which complicates the situation, as only symptomatic treatment is the current solution. In this regard we have targeted the dengue protease NS2B-NS3 that is responsible for the replication. The series was designed with the help of molecular modeling approach using docking protocols. The series comprised of different scaffolds viz. cinnamic acid analogs (CA1–CA11), chalcone (C1–C10) and their molecular hybrids (Lik1–Lik10), analogs of benzimidazole (BZ1-BZ5), mercaptobenzimidazole (BS1-BS4), and phenylsulfanylmethylbenzimidazole (PS1-PS4). Virtual screening of various natural phytoconstituents was employed to determine the interactions of designed analogs with the residues of catalytic triad in the active site of NS2B-NS3. We have further synthesized the selected leads. The synthesized analogs were evaluated for the cytotoxicity and NS2B-NS3 protease inhibition activity and compared with known anti-dengue natural phytoconstituent quercetin as the standard. CA2, BZ1, and BS2 were found to be more potent and efficacious than the standard quercetin as evident from the protease inhibition assay.