Table 4.

The dock score of screened phytochemicals binding at the active sites of the RdRp and their important interactions with various amino acid residues.

Phytochemicals	B.E. (kcal/mole)	Important interactions at the active site (residues 611 to 626), divalent cationic residue (ASP618), catalytic site (753–767) and NTP entry channel (LYS545, ARG553, ARG555)
Glycyrrhizic acid	−9.9	Hydrogen bond: ARG624, ALA762, TRP800, ALA558, SER682, THR556, ARG555; Carbon hydrogen bond: GLY616; Pi-Alkyl: TRP800; VDW: TRP617, GLY616, ASP618, LYS798, VAL763, PHE812, ASP452, GLU811, LYS551, ASP623, VAL557, SER814, SER549, ALA547, ILE548, LYS545.
Limonin	−8.2	Hydrogen bond: TRP800, TRP617; Pi-Alkyl: CYS622, LYS798; Pi-Pi T-shaped: HIS810; VDW: PRO620, TYR619, ASP760, SER814, ASP761, ASP618, GLY616, GLU811, ALA797, LYS551
7-Deacetyl-7-benzoylgedunin	−8.2	Hydrogen bond: ALA762; Alkyl/Pi-Alkyl: LYS798; Carbon hydrogen bond: TRP617, GLU811; Pi-Anion: LYS798, Pi-Cation: ASP761, LYS551, ASP618; VDW: ALA797, TRP800, PHE812, ASP760, TYR619, PRO620.
Limonin glucoside	−8.2	Hydrogen bond: ARG624, ALA554, ARG836; Carbon hydrogen bond: SER549; Alkyl/Pi-Alkyl: HIS439, ALA550, LYS551, ARG555; VDW: ARG553, ASP452, ASP623, TYR456, SER682, VAL557, MET542, LYS545, SER814.
7-Deacetylgedunin	−8.1	Hydrogen bond: ALA762; Carbon hydrogen bond: TRP617, GLU811; Pi-Alkyl: LYS798; Pi-Sigma: TRP800; Pi-Anion: ASP761; VDW: TYR619, ASP760, ASP618, PHE812, ALA797.
Obacunone	−7.8	Hydrogen bond: LYS551, ARG624; Alkyl: ARG555; Pi-Anion: ASP452; VDW: SER549, ARG836, ALA550, ARG553, ALA554, ILE548, THR556, TYR456.