Table 2.

Comparative assessment of Withanolides A and B with Beta, Delta, Gamma and Omicron variants of SARS-CoV-2 spike glycoprotein

S.No.	SARS-CoV-2 variant	PDB ID	Ligand	Binding energy (B.E.) using AutoDock Vina (kcal/mol)	Binding energy (B.E.) using AutoDock v4.2.6 (kcal/mol)	Kd (dissociation constant)
1.	Betaa	6M0J	Withanolide A	−9.3	−9.1	214.02 nM
2.	Betaa	6M0J	Withanolide B	−9.2	−8.88	308.96 nM
3.	Gamma	7EKC	Withanolide A	−8.6	−4.94	240.74 µM
4.	Gamma	7EKC	Withanolide B	−7.5	−5.44	102.53 µM
5.	Delta	7V7N	Withanolide A	−10.0	−8.63	475.1 nM
6.	Delta	7V7N	Withanolide B	−9.6	−9.27	159.47 nM
7.	Omicron (BA.1)	Modeled Structure	Withanolide A	−9.4	−7.67	2.4 µM
8.	Omicron (BA.1)	Modeled Structure	Withanolide B	−9.7	−8.09	1.17 µM