Table 1.

IC₅₀ values of analogues against MERS and SARS 3CL^pro

Sl. No.	R1	R2	R3	R4	SARS IC50 (μM)	MERS IC50 (μM)
3a	COOH	Cl	CH3	3-COOH	>50	>50
3b	COOH	Cl	CF3	3-COOH	>50	>50
3c	COOH	H	CF3	3-COOH	>50	>50
3d	COOH	Cl	Ph	3-COOH	44.7 ± 5.1	>50
3e	COOH	Cl	CH3	H	>50	>50
3f	COOH	Cl	Ph	H	16.4 ± 0.7	12.2 ± 2.2
3g	COOH	Cl	Ph	4-F	20.2 ± 0.3	10.1 ± 1.8
3h	COOH	Cl	Ph	4-CH(CH3)2	6.0 ± 1.2	7.3 ± 2.1
3i	COOH	Cl	Ph	4-CH(CH3)3	5.8 ± 1.5	7.4 ± 2.2
3j	H	H	Ph	H	>50	>50
3k	H	H	Ph	COOH	6.4 ± 1.2	5.8 ± 1.6
3l	H	H	CH3	COOH	>50	>50
3m	COOH	H	Ph	H	41.2 ± 9.5	30.3 ± 4.5
3n	COOH	H	Ph	4-F	37.5 ± 0.7	>50
3o	COOH	H	Ph	4-CH(CH3)2	11.7 ± 2.5	8.9 ± 1.8
3p	COOH	H	Ph	4-CH(CH3)3	8.6 ± 2.1	7.7 ± 2.2
3q	COOH	H	Ph	4-CN	18.7 ± 4.5	9.6 ± 1.6
3r	COOH	H	Ph	4-OCH3	30.7 ± 5.8	8.9 ± 1.8
3s	No ring A		Ph	COOH	>50	>50