Table 2.

Potential natural components targeting SARS-nCoV 3CL^pro.

Components	Categories	IC50 (μg/ml)	CC50 (μg/ml)	SI	References
Iguesterin	Triterpenes	1.05 ± 0.12	NM	NM	Ryu et al., 2010b
Hesperetin	Flavonoids	2.5 ± 0.8	820 ± 15	328	Lin et al., 2005
Pristimerin	Triterpenes	2.56 ± 0.31	0.41*	0.16	Ryu et al., 2010b *da Costa et al., 2008
Tingenone	Triterpenes	4.16 ± 0.04	16.83 ± 1.65	4.05	Ryu et al., 2010b Chhetri et al., 2015
Amentoflavone	Flavonoids	4.47 ± 0.65	53 ± 0.9*	11.9	Ryu et al., 2010a *Yin et al., 2014
Celastrol	Triterpenes	4.64 ± 0.09	0.90 ± 0.04*	0.19	Ryu et al., 2010b *Zhang et al., 2018
Luteolin	Flavonoids	5.72 ± 0.63	48.1*	8.41	Ryu et al., 2010a *Dai et al., 2019
Curcumin	Polyphenol	8.66 ± 1.36	11*	1.27	Ryu et al., 2010b *Chen et al., 2013
Herbacetin	Flavonoids	10.03	NM	NM	Jo et al., 2020
Quercetin	Flavonoids	10.67 ± 0.85	199.2*	18.7	Ryu et al., 2010a *Dai et al., 2019
Rhoifolin	Flavonoids	12.31	NM	NM	Jo et al., 2020
Pectolinarin	Flavonoids	23.52	449.0 ± 13.0*	19.1	Jo et al., 2020 *Simões et al., 2011
Dieckol	Phlorotannin	50.6 ± 1.6	>148.5	>2.9	Park et al., 2013
Sinigrin	Glucosinolates	90.1 ± 4.2	>5000	>55.5	Lin et al., 2005
Apigenin	Flavonoids	75.88 ± 5.78	69.2*	0.91	Ryu et al., 2010a *Dai et al., 2019
Aloe emodin	Flavonoids	99.1 ± 2.1	3135 ± 9	31.63	Lin et al., 2005
Indigo	Food colorings	190 ± 2.6	917 ± 18	4.83	Lin et al., 2005
Beta-sitosterol	Sterols	502.1 ± 2.9	613 ± 9	1.22	Lin et al., 2005