In Silico Analysis of Calotropis procera-Derived Phytochemicals Targeting 3CL Proteoase of SARS-CoV-2

The coronavirus known as SARS-CoV-2 has enveloped virions with single-stranded positive-sense RNA genome. It infects mammals, including humans, via the respiratory tract. The non-structural protein of coronavirus, main protease (3CLp) is a key enzyme in the disease's progression. This study aimed to screen phytochemicals derived from Calotropis Procera as potential drugs against 3CLp. Through database search, 50 phytochemicals were identified in the Calotropis sp. To evaluate the possible drug-like properties of these phytochemicals, the studies like, ADMET (Absorption, Distribution, Metabolism, Excretion, Toxicity) analysis, molecular docking and density functional theory (DFT) were performed. Furthermore, GC-MS was performed using water and ethanolic extracts from the plant leaves. The ADMET analysis and docking results showed 11 phytochemicals as probable drug candidates against 3CLp of SARS-CoV-2. All these phytochemicals showed ≥ - 4.3 kcal/mol binding affinity, similar to previously reported inhibitors. Furthermore, based on band energy gap, EHOMO, ELUMO, and DFT analyses, it was shown that these phytochemicals had a significant level of reactivity necessary for the interaction. Among all, the phytochemicals uscharin, voruscharin, frugoside, coroglaucigenin, and benzoylisolineolone may be considered the top 5 drug-like candidates against 3CLp. Furthermore, the selected phytochemicals may be employed for in vitro and in vivo studies for the advancement of a probable drug alongside SARS-CoV-2.