Structure-Based Screening of Novel Lichen Compounds for SARS Coronavirus Main protease (Mpro) and Angiotensin-Converting Enzyme 2 (ACE2) inhibitory potentials as multi-target inhibitors of COVID-19

Abstract Outbreak of SARS-CoV-2 and massing death caused by it all over world has imposed great concern on scientific community to develop potential drugs to combat with Coronaviruas disease 19 ( COVID-19 ). In this regard, lichen metabolites may offer a vast reservoir for discovery of anti-viral drug candidates. Therefore to find novel compounds against COVID-19, we created a library of 412 lichen compounds and subjected to virtual screening against two molecular targets; SARS-CoV-2 target- Main protease (Mpro) and host cell target- Angiotensin-converting enzyme 2 (ACE2). All the ligands were virtually screened, and 80 compounds were found to have better docking score with both the targets. These compounds were assessed for druglikeness analysis where 27 compounds were found to fit well for redocking studies. The results of redocking by X-Score showed that 7 out of 27 compounds were found to have high affinities with Mpro as well ACE2 which reflect that these compounds can function as dual inhibitors. Molecular docking, druglikeness, X-Score and toxicity analysis resulting seven novel lichen compounds (Orcinyllecanorate, Siphulin, Fremontol, Gyrophoric acid, Rhizocarpic acid, Ovoic acid, and Umbilicaric acid) with Mpro and ACE2 multi-target activities and they can be used as hit compounds to develop potential antiviral agents against SARS-CoV-2. These lichen compounds may be a suitable candidate for further experimental analysis.