Tea flavonoids inhibiting multiple proteins related to SARS-CoV-2 judged from molecular docking

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has caused Coronavirus Disease 2019 (COVID-19) pandemic. Flavonoids-derived Chinese patent medicines have outstanding curative effects for the improvement and treatment of COVID-19. Numerous studies were suggesting that flavonoid-rich tea has antiviral effects. In vitro studies demonstrated that bioactive compounds of tea flavonoids could inhibit the activity of SARS-CoV-2 main protease (Mpro). However, bioactive compounds from tea flavonoids with antiviral effect, and the potential molecular mechanisms are unclear. In this study, we performed a molecular docking of 468 tea flavonoids and their derivatives with Mpro, RNA-dependent RNA polymerase (RdRp), angiotensin-converting enzyme 2 (ACE2), compared with the positive clinical drugs of each target. The results suggest that ACE2 and RdRp are the main targets inhibited by tea flavonoids according to the binding affinity. Quercetin 3-glycosides (Q3G), Isovitexin, and 4’,5,7-Trihydroxyflavanone 7-O-Fructoside (S)-form (TF) would be considered as the potential candidate compounds of RdRp and ACE2. Our study provides a theoretical basis for further drug design of anti-COVID-19 bioactive compounds.