Antiviral activity and cytotoxicity assay of novel non-covalent SARS-CoV-2 M^pro inhibitors by propagation in Vero E6 cells.

Comp. ID	Cytotoxicity IC50 (µM ± SEa)	Antiviral assay (qPCR)				SIb
		Inhibition %		EC50 and EC90 (µM ± SEa)
		1 µM	10 µM	EC50	EC90
17	>200	22.25	42.51	22.1 ± 1.012	36.13 ± 2.31	9
21	48.8 ± 3.72	83.49	95.92	0.0138 ± 0.00198	3.60 ± 0.42	3544
22	193.0 ± 14.7	88.16	94.10	0.1093 ± 0.01105	1.738 ± 0.54	1766
23	47.6 ± 3.62	78.96	92.92	0.0216 ± 0.00656	3.11 ± 1.61	2201
24	21.6 ± 1.64	94.01	96.22	0.0762 ± 0.00973	3.437 ± 0.55	283.3
25	121.0 ± 9.21	92.48	97.08	0.1066 ± 0.00115	2.50 ± 0.841	1135
26	87.3 ± 6.65	87.61	94.05	0.0376 ± 0.00423	3.801 ± 0.041	2323
27	64.4 ± 4.91	94.36	96.52	0.1035 ± 0.00344	2.601 ± 1.02	622.2
28	139.0 ± 10.6	92.71	95.60	0.108 ± 0.00304	1.41 ± 0.91	1278
29	151.0 ± 11.5	94.10	96.39	0.0519 ± 0.00512	8.953 ± 2.01	2909
Remdesivir	43.1 ± 3.28	94.23	97.58	0.0099 ± 0.00175	0.0835 ± 1.88	7195

^aSE represents standard error from triplicate readings.

^bSelectivity index (SI) was calculated by dividing of IC₅₀ value for Vero cell cytotoxicity by the EC₅₀ of the antiviral assay.