Repurposing of some natural product isolates as SARS-COV-2 main protease inhibitors via in vitro cell free and cell-based antiviral assessments and molecular modeling approaches - Abdallah, H M; El-Halawany, A M; Sirwi, A; El-Araby, A M; Mohamed, G A; Ibrahim, S RM; Koshak, A E; Asfour, H Z; Awan, Z A; Elfaky, MA (Pharmaceuticals (Basel), 2021)