Novel 1,3-Indanedione-Thiazole Hybrids as Small-Molecule SARS-COV-2 Main Protease Inhibitors With Potential anti-Coronaviral Activity

Abstract

Since arising in 2019, COVID 19 has been causing rapidly-increasing mortality and morbidity rates across the globe. Herein, novel 1,3-indanedione-thiazole hybrids were designed and synthesized as small-molecule SARS-COV-2 Main protease (Mpro) inhibitors with potential anti-covid activity. All target compounds were screened in vitro for their ability to inhibit SARS-COV-2 Mpro. Several compounds displayed potent SARS-COV-2 Mpro inhibition at one-digit IC50 values ranging from 4.3 to 9.9 µM, compared to ritonavir (IC50= 2.4 µM). Moreover, antiviral assay revealed the ability of compounds 12c, 12f, and 16a to significantly inhibit the replication of SARS-COV-2 in Vero cells at EC50 values of 7.79, 2.79 and 1.65 µM, respectively, relative to ritonavir (EC50 = 1.72 µM). Cytotoxicity assay was also conducted. None of the tested compounds exhibited significant cytotoxicity in Vero cells showing CC50 values from 171.77 to 299.96 µM and SI from 38.5 to 178.6 µM. In addition, a docking study revealed proper orientation and well-fitting of title compounds into the binding pocket of SARS-COV-2 Main protease.