Table 10.  Binding energies of WS phytoconstituents with SARS-CoV-2 main protease/3CL-pro (PDB ID: 6LU7) in comparison to the FDA approved standard reference drugs (Oberadilol and Poziotinib).
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S. No.  Ligands  BE (kcal/mol)   K d  Interacting amino acids  BE(kcal/mol)  Kd  Interacting amino acids  TE(kcal/mol)  VDW  HB  EI  Interacting amino acids   
1.  Withaferin A  –2.85  8.21 mM  Tyr126, Gln127, Gly138, Va171, Gly170, Lys137, Lys5  –8.4  670.89 nM  Arg105, Ile106, Val104, Ser158, Phe294,Phe112, Phe8, Thr111, Asp295, Asn151,Gln110, Thr292, Gln107  –98.51  –78.64  –19.87  0  Gly143, Ser144, Cys145, His163, Met165, Glu166, Gln189, Thr190, Asn142, Leu141, Phe140   
2.  Withanolide A  –5.26  139.0 µM  Lys5, Gln127, Tyr126, Val125, Ser139, Lys137, Glu288, Glu290  –8.5  592.38 nM  Asp289, Thr199, Glu290, Arg131, Lys137, Tyr239, Leu272, Leu287, Leu286, Met276, Gly275  –91.61  –70.18  –21.43  0  Gly179, Asn180, Phe181, Asn84, Cys85, Arg40, Phe185, Tyr54, Asn53, Pro52, Arg188   
3.  Withanolide B  –5.67  69.79 µM  Ser139, Gly138, Lys137, Cys128, Glu290, Gln127, Tyr126, Val125  –8.3  845.65 nM  Leu287, Tyr239, Tyr237, Leu272, Leu286, Asn238, Thr199, Asp289, Glu288, Arg131, Glu290, Lys137  –89.17  –72.53  –16.64  0  His163, His164, Met165, Cys145, Ser144, Phe140, Leu141, Asp142, Gly143, Thr25, Met149, Thr45, Ser46, Thr24   
4.  Withanolide D  –5.55  85.19 µM  Tyr126, Gln127, Gly138, Ser139, His172, Gly170, Lys137, Lys5  –8.7  424.04 nM  Tyr239, Leu287, Val204, Leu272, Tyr237, Asn238, Arg131, Lys137, Thr199, Leu286, Asp289  –104.35  –85.29  –19.06  0  Thr26, Leu27, Cys145, Gly143, Ser144, His164, Asn142, Met165, Glu166, Pro168, Thr190, Gln189, Arg188, Met49,His41   
5.  Withanolide E  –5.2  154.68 µM  Tyr126, Gln127, Lys5, Glu290, Lys137, Gly138, Ser139  –8.1  1.16 µM  Asn238, Asp289, Arg131, Lys137, Thr199, Leu286, Leu287, Tyr239, Leu272, Tyr237  –97.42  –70.98  –26.44  0  Arg131,Asn133, Ala194, Gly195, Asp289, Asp197, Thr196, Thr199, Thr198, Asn238   
6.  Withanone  –6.14  31.77 µM  Val125, Tyr126, Gln127, Cys128, Ser139, Gly138, Lys137, Ala129, Glu290  –8.4  707.34 nM  Leu286, Tyr239, Lys137, Asp197, Arg131, Thr198, Thr199, Asn238, Tyr237, Met276, Gly275, Leu272, Leu271, Leu287  –100.18  –88.69  –11.49  0  Thr24, Thr25, Thr26, His41, Gly143, Cys145, Ser144, His164, His163, His172, Phe140, Glu166, Leu141, Asn142, Met49, Ser46   
7.  Viscosalactone B  –4.86  274.4 µM  Val104, Asn151, Phe8, Arg298, Gln127, Asp295, Phe294, Thr111, Thr292, Gln110, Gln107, Ile106, Arg105  –8.2  969.04 nM  Gly278, Lys137, Asp289, Arg131, Tyr239, Thr199, Leu287, Leu286, Leu272, Gly275,Met276, Asn274, Asn277  –97.17  –67.45  –29.72  0  Tyr239, Asn238, Tyr237, Thr199, Leu287, Leu286, Ala285, Gly278, Asn277, Met276,Gly275   
8.  Anaferine  –5.13  174.99 µM  Glu290, Cys128, Lys5, Gln127, Tyr126, Lys137  –5.7  66.02 µM  Cys145, Asn142, Leu141, Phe140,Glu166, Ser144,His172,Met165, His164, Gln189, Asp187, Arg188, Met49, His41  –76.27  –67.75  –8.52  0  Thr25, Thr26, Leu27, Cys145, His163, Met165, Glu166,His172, Phe140, Leu141,Ser144, Gly143   
9.  Withasomnine  –5.22  149.2 µM  Ser158, Ile152, Asp153, Asn151, Thr111, Asp295, Phe294, Thr292, Gln110  –6.2  28.68 µM  Ile152, Phe8, Val104, Ile106, Gln110, Thr111, Asn151, Asp153, Phe294  –71.96  –60.03  –11.94  0  His41, His163, His164, Met165, Cys145, Ser144, His172, Glu166, Phe140, Leu141   
10.  Oberadilol  –2.23  23.18 mM  Lys137, Glu290, Gln127, Tyr126, Lys5  –6.9  9.00 µM  Leu286, Tyr239, Lys137, Asp197, Arg131, Thr198, Thr199, Asn238, Tyr237, Met276, Gly275, Leu272, Leu271, Leu287  –100.96  –94.41  –6.55  0  His163, Cys145, His164, Met165, Asn142, Glu166, Leu141, Leu167, Pro168, Gln189, Met49, Asp187, His41   
11.  Poziotinib  –4.49  513.87 µM  Tyr126, Gln127, Cys128, Lys5, Ala129, Glu290, Lys137, Gly138, Ser139  7.7  2.20 µM  Gly278, Ala285, Gly275, Tyr237, Leu272, Asn238, Tyr239, Thr199, Asp289, Arg131, Leu286, Lys137, Leu287, Met276  –111.32  –96.66  –14.66  0  His41, Cys145, His164, Asp187, Arg188, Met165, Gln189, Glu166, Thr190, Ala191, Gln192, Pro168, Phe140, Leu141, Asn142