Discovery of novel thioquinazoline-N-aryl-acetamide/N-arylacetohydrazide hybrids as anti-SARS-CoV-2 agents: Synthesis, in vitro biological evaluation, and molecular docking studies

•Two series of thioquinazolines were investigated for their activity on SARS-CoV-2.•The thioquinazolines 17g, 18c and 18f showed potent antiviral activity.•Compounds 18c and 18f demonstrated potential selectivity toward the SARS-CoV-2.•Compounds 17g, 18c, and 18f demonstrated satisfactory physicochemical properties.•The docking simulation predicted the binding pattern of the target compounds. In the current investigation, two novel series of (tetrahydro)thioquinazoline-N-arylacetamides and (tetrahydro)thioquinazoline-N-arylacetohydrazides were designed, synthesized and investigated for their antiviral activity against SARS-CoV-2. The thioquinazoline-N-arylacetamide 17g as well as the tetrahydrothioquinazoline-N-arylacetohydrazides 18c and 18f showed potent antiviral activity with IC50 of 21.4, 38.45 and 26.4 µM, respectively. In addition, 18c and 18f demonstrated potential selectivity toward the SARS-CoV-2 over the host cells with SI of 10.67 and 16.04, respectively. Further evaluation of the mechanism of action of the three derivatives 17g, 18c, and 18f displayed that they can inhibit the virus at the adsorption as well as at the replication stages, in addition to their virucidal properties. In addition, 17g, 18c, and 18f demonstrated satisfactory physicochemical properties as well as drug-likeness properties to be further optimized for the discovery of novel antiviral agents. The docking simulation on Mpro binding site predicted the binding pattern of the target compounds rationalizing their differential activity based on their hydrophobic interaction and fitting in the hydrophobic S2 subsite of the binding site [Display omitted]