PROS1 and severe acute respiratory syndrome: The most active bioactive compound is glycyrrhizin which acts by inhibiting the interaction between S-protein and ACE2 thereby preventing viral invasion.35,36 Pilcher and Cinatl et al suggested that glycyrrhizin should be assessed for the treatment of SARS as an alternative option.37,38 Further investigation was done by Hoever et al and Fiore et al who confirmed the activity of glycyrrhizin against SARS coronavirus.39,40