Table 1.

Examples of some promising natural molecules with coronavirus inhibitory activity

Compound	Chemical group	IC50/EC50 values	Coronavirus type targeted	References
Glycyrrhizin	Saponin	EC50 = 364.5 μM	SARS-CoV	[26]
Saikosaponin B2	Saponin	EC50 = 1.7 ± 0.1 mmol/L	SARS-CoV	[29]
Saikosaponin A	Saponin	EC50 = 8.6 ± 0.3 mmol/L	SARS-CoV
Tetra-O-galloyl-β-D-glucose	Polyphenol	EC50 = 4.5 μM	SARS-CoV	[30]
Luteolin	Flavonoid	EC50 = 10.6 μM	SARS-CoV
Sinigrin	Polyphenol	IC50 = 217 μM	SARS-CoV	[31]
β-Sitosterol	Phytosterol	IC50 = 1210 μM	SARS-CoV
Hesperetin	Flavonoid	IC50 = 8.3 μM	SARS-CoV
Amentoflavone	Flavonoid	IC50 = 8.3 μM	SARS-CoV	[33]
Luteolin	Flavonoid	IC50 = 20.2 μM	SARS-CoV
Quercetin	Flavonoid	IC50 = 23.8 μM	SARS-CoV
Apigenin	Flavonoid	IC50 = 280.8 μM	SARS-CoV
Isobavachalcone	Flavonoid	IC50 = 7.3 ± 0.8 μM	SARS-CoV	[34]
Psoralidin	Flavonoid	IC50 = 4.2 ± 1.0 μM	SARS-CoV
Tomentin A	Flavonoid	IC50 = 6.2 ± 0.04 μM	SARS-CoV	[35]
Tomentin B	Flavonoid	IC50 = 6.1 ± 0.02 μM	SARS-CoV
Tomentin E	Flavonoid	IC50 = 5.0 ± 0.06 μM	SARS-CoV
3′-O-Methyldiplacol	Flavonoid	IC50 = 9.5 ± 0.10 μM	SARS-CoV
Isoliquiritigenin	Flavonoid	IC50 = 61.9 ± 11.0 μM	SARS-CoV	[37]
Quercetin	Flavonoid	IC50 = 52.7 ± 4.1 μM	SARS-CoV
Kaempferol	Flavonoid	IC50 = 116.3 ± 7.1 μM	SARS-CoV
Kazinol F	Flavonoid	IC50 = 43.3 ± 10.4 μM	SARS-CoV
Broussochalcone B	Flavonoid	IC50 = 57.8 ± 0.5 μM	SARS-CoV
Papyriflavonol A	Flavonoid	IC50 = 103.6 ± 17.4 μM	SARS-CoV
Terrestrimine	Cinnamic amide	IC50 = 15.8 ± 0.6 μM	SARS-CoV	[36]
Blancoxanthone	Xanthone	EC50 = 3 μg/ml	HCoV 229E	[38]
Pyranojacareubin	Xanthone	EC50 = 15 μg/ml	HCoV 229E
Lycorine	Alkaloid	EC50 = 15.7 IU/ml	SARS-CoV	[41]
Tylophorine	Alkaloid	EC50 = 58 ± 4 nM	TGEV	[42]
7-Methoxycryptopleurine	Alkaloid	EC50 = 20 ± 1 nM	TGEV
Jubanine G	Alkaloid	EC50 = 13.41 ± 1.13 μM	PEDV	[43]
Jubanine H	Alkaloid	EC50 = 4.49 ± 0.67 μM	PEDV
Nummularine B	Alkaloid	EC50 = 6.17 ± 0.50 μM	PEDV
Tingenone	Triterpene	IC50 = 9.9 ± 0.1 μM	SARS-CoV	[33]
Iguesterin	Triterpene	IC50 = 2.6 ± 0.3 μM	SARS-CoV
Pristimererin	Triterpene	IC50 = 5.5 ± 0.7 μM	SARS-CoV
Dihydrotanshinone I	Diterpene	IC50 = 4.9 ± 1.2 μM	SARS-CoV	[45]
Cryptotanshinone	Diterpene	IC50 = 0.8 ± 0.2 μM	SARS-CoV
Tanshinone IIA	Diterpene	IC50 = 1.6 ± 0.5 μM	SARS-CoV
Schimperinone	Triterpene	EC50 = 0.28 ± 0.09 μM	PEDV	[45]
Xanthoangelol	Chalcone	IC50 = 11.4 ± 1.4 μM	SARS-CoV	[52]
Hirsutenone	Diarylheptanoid	IC50 = 3.0 ± 1.1 μM	SARS-CoV	[53]
Rubranoside	Diarylheptanoid	IC50 = 7.2 ± 2.2 μM	SARS-CoV
Curcumin	Diarylheptanoid	IC50 = 5.7 μM	SARS-CoV
APA	Lectin	EC50 = 0.45 ± 0.08 μg/ml	SARS-CoV	[54]
UDA	Lectin	EC50 = 1.3 ± 0.1 μg/ml	SARS-CoV	[54]