Table 1.

Phytochemicals reported to have potential inhibitory properties against SARS-CoV-2 Mpro.

Class of Compound	Compound	Distributed in	Including Food Plants and Spices *	Inhibition (%), with IC50 Value, μM	Binding Energy ** (kcal/mol)	Ref.
Isoflavone	Daidzein	Streptomyces, and predominantly in Fabaceae plant family	Vigna radiata, Glycine max	56	−6.5	[93]
Isoflavone	Puerarin	Predominantly in Fabaceae plant family	Cicer arietinum, Glycine max, Glycyrrhiza glabra, Phaseolus vulgaris, Pisum sativum, Vigna radiata	42 ± 2	−6.63	[94]
Flavonol	Myricetin	Widely distributed in various plant families	Buchanania lanzan, Mangifera indica, Asparagus officinalis, Davidsonia pruriens, Hippophae rhamnoides, Vicia faba, Salvia hispanica, Thymus capitatus, Punica granatum, Hibiscus sabdariffa L., Moringa oleifera, Eugenia jambolana, Pimenta dioica, Plinia pinnata, Syzygium aromaticum, Syzygium cumini, Syzygium samarangense, Diploknema butyracea, Ampelopsis grossedentata, Morella rubra	43 ± 1	−22.13	[41,91]
Flavonol	Quercetin	Mucor hiemalis, and widely distributed in various plant families	Allium cepa, Allium Sativum, Allium ascalonicum, Mangifera indica, Annona muricata, Asparagus officinalis, Capparis spinosa, Carica papaya, Garcinia cowa, Garcinia dulcis, Brassica oleracea var. gongylodes, Raphanus sativus, Momordica charantia, Ceratonia siliqua, Vicia faba, Crocus sativus, Punica granatum, Toona sinensis, Moringa stenopetala, Musa acuminata, Psidium guajava, Phyllanthus emblica, Zea mays, Nigella sativa, Eriobotrya japonica, Prunus avium, Kadsura heteroclita, Capsicum annuum, Zingiber officinale	93 ± 5	−7.6	[23,91]
Flavonol	Quercetagetin (Quercetagenin)	Asteraceae, Eriocaulaceae, Fabaceae plant families	Acacia catechu, Leucaena glauca	145 ± 6	−15.2	[91]
Flavanonol	Ampelopsin (dihydromyricetin)	Widely distributed in various plant families	Asparagus officinalis, Punica granatum L., Pimenta dioica, Zea mays, Syzygium cumini, Capsicum annuum, Vitis rotundifolia, Manilkara zapota,	128 ± 5	−7.5	[91,95]
Flavanonol	Ampelopsin-4′-O-α-d-glucopyranoside	Widely distributed in various plant families	-	195 ± 5	7.4	[91]
Flavanone	Naringenin	Widely distributed in various plant families	Camellia sinensis, Prunus cerasus, Prunus persica, Citrus grandi, etc.	150 ± 10	−7.7	[91,96]
Flavan-3-ol	Epigallocatechin gallate (EGCG)	Widely distributed in various plant families	Vitis vinifera	171 ± 5	−7.6 −8.2	[88,91,93]
Flavone	Vitexin	Widely distributed in various plant families	Pisum sativum	180 ± 6	−7.6	[97]
Hydrocinnamic acid	Chlorogenic acid	Widely distributed in various plant families	Lactuca sativa	39.48 ± 5.51	−12.98	[91,98]
Dihydroxycinnamic acid	Caffeic acid	Widely distributed in various plant families	Actinidia deliciosa, Allium Sativum, Mangifera indica, Ilex paraguariensis, Carica papaya, Beta vulgaris, Terminalia catappa, Terminalia chebula, Brassica oleracea var. gongylodes, Raphanus sativus, Momordica charantia, Arachis hypogaea, Cicer arietinum, Glycine max, Phaseolus vulgaris, Pisum sativum, Tetrapleura tetraptera, Ocimum basilicum, Rosmarinus officinalis, Thymus capitatus, Punica granatum, Triticum aestivum, Zea mays, Crataegus pinnatifida, Prunus avium, Coffea arabica, Citrus limon, Citrus sinensis, Solanum lycopersicum, Solanum phureja, Solanum pimpinellifollium, Solanum tuberosum, Curcuma longa, Bergera koenigii	197 ± 1	−12.4985	[91,99]
Polyphenol	Ellagic acid	Widely distributed in various plant families	Mangifera indica, Terminalia chebula, Punica granatum, Moringa oleifera, Moringa peregrine, Moringa stenopetala, Eugenia jambolana, Myrciaria cauliflora, Syzygium aromaticum, Syzygium cumini, Emblica officinalis, Rubus idaeus L.,	11.8 ± 5.7	−15.955	[100,101]
Phenylpropanoid	Chicoric acid	Alliaceae, Asteraceae, and Labiatae plant families	Lactuca sativa, Ocimum basilicum, Cichorium intybus	-	−8.2	[93]
Polyphenol	Gallocatechin gallate (GCG)	Cistaceae, Elaeagnaceae, Ericaceae, Polygonaceae, Theaceae, and Vitaceae plant families	Hippophae rhamnoides, Camellia sinensis, Vitis vinifera	5.774 ± 0.805	−9	[93]
Flavan-3-ol	Epicatechin gallate (ECG)	Cistaceae, Elaeagnaceae, Ericaceae, Polygonaceae, Theaceae, and Vitaceae plant families	Hippophae rhamnoides, Camellia sinensis, Vitis vinifera, Rheum sp.	12.5	−8.2	[93,102]
Flavonoids	Kaempferol glycosides	Widely distributed in various plant families	Prunus avium, Allium cepa	125.00	−7.4, −8.1	[103,104]
Flavonoids	Isorhamnetin glycosides	Widely distributed in various plant families	Brassica oleracea, Allium ascalonicum	13.13	−6.6, −8.2	[104,105]
Flavonoids	Pectolinarin	Labiatae, Plantaginaceae, and Verbenaceae plant families		37.7	−8.2	[40,106,107]
Flavonoid	Herbacetin	Asteraceae, Chenopodiaceae, Crassulaceae, Ephedraceae, Equisetaceae, Linaceae, Malvaceae, Papaveraceae, Phrymaceae, Primulaceae, Rosaceae, Rutaceae, and Taxaceae plant families	Linum usitatissimum, Citrus limon	33.1	−7.2	[40,106]
Flavonoid	Rhoifolin (apigenin-7-O-rhamnoglucoside)	Acanthaceae, Anacardiaceae, Apocynaceae, Fabaceae, Lythraceae, Oleaceae, Rutaceae, and Caprifoliaceae plant families	Vicia faba, Hordeum vulgare L	27.4	−8.2	[40,106]
Flavonoid metabolite	Vicenin	Rare compound	Trigonella foenum-graecum	38.856	−8.97	[87,108]
Flavone	Isorientin 4′-O-glucoside 2″-O-p-hydroxybenzoate	Gentianaceae and Lamiaceae	Ocimum sanctum	-	−8.55	[87]
Biflavonoid	Amentoflavone	Various plant species: yew, juniper, oak, and willow	Garcinia brasiliensis, Garcinia dulcis, Garcinia hombroniana, Garcinia indica, Garcinia intermedia, Garcinia livingstonei, Garcinia madruno, Garcinia mangostana, Garcinia morella, Garcinia wightii, Garcinia xanthochymus,	-	−10.0	[23]
Flavonoid	Silymarin (silibinin)	Asteraceae	Silybum marianum	46.88	−7.6	[23]
Isoflavone	Torvanol A	Solanaceae		-	−7.5	[23]
Flavone	Scutellarein	Asphodelaceae, Asteraceae, Fabaceae, Bignoniaceae, Labiatae, Plantaginaceae, Polygonaceae, and Verbenaceae plant families	Oroxylum indicum, Garcinia andamanica Origanum majorana	-	−7.4	[23]
Flavone	Apigenin	Widely distributed in various plant families, mainly in Labiatae	Artemisia diffusa., Ocimum americanum var. pilosum Ocimum basilicum, Ocimum x citriodorum, Rosmarinus officinalis, Salvia officinalis, Thymus piperella, Passiflora foetida, Piper peepuloides, Kaempferia parviflora	925	−7.1	[23,109]
Isoflavone	5,7,3′,4′-Tetrahydroxy-2′-(3,3-dimethylallyl) isoflavone	Fabaceae		-	−29.57	[41]
Polyphenol	Methyl rosmarinate	Labiatae	Rosmarinus officinalis	21.32	−20.62	[41,110]
Flavonoid	Baicalin	Mainly in Labiatae	Oroxylum indicum	6.41 ± 0.95 μM in vitro 27.87 ± 0.04 μM in cells	−8.85	[99,111]
Flavonoid	Baicalein	Mainly in Labiatae	Oroxylum indicum	0.94 ± 0.20 μM in vitro 2.94 ± 1.19 μM in cells		[98]
Alkaloid	Capsaicin	Solanaceae	Capsicum annuum	-	−13.90	[112]
Alkaloid	Psychotrine	Mainly in Rubiaceae		-	−13.5	[112]
Alkaloid	Achyranthine	Amaranthaceae		-	4.1	[113]
Terpenoid	Withanoside V	Solanaceae		5.774 ± 0.805	−10.32	[114]
Triterpenoid	Ursolic acid	Apocynaceae, Asteraceae, Boraginaceae, Dryopteridaceae, Ericaceae, Gesneriaceae, Labiatae, Lamiaceae, Lythraceae, Moraceae, Myricaceae, Nothofagaceae, Oleaceae, Rosaceae, Rubiaceae, Solanaceae, Stilbaceae, and Ulmaceae plant families	Vaccinium macrocarpon, Punica granatum, Olea europaea, Prunus avium, Pyrus spp.	12.6	−8.2	[114]
Triterpenoid	Glycyrrhizic acid	Asteraceae and Fabaceae	Stevia rebaudiana, Glycyrrhiza glabra	-	−8.03	[115,116]
Pentacyclic triterpenoid	Torvoside H	Solanaceae	-	-	−8.4	[23]
Pentacyclic triterpenoid	Lupeol	In Coprinaceae, and widely distributed in various plant families	Cichorium intybus, Zanthoxylum armatum, Olea europaea, Myrica rubra, Morus alba, Ficus carica, Carica papaya	-	−7.6	[116]
Diterpene	Scopadulcic acid B	Plantaginaceae (Scoparia dulcis)	-	-	−8.5	[23]
Diterpene	Ovatodiolide	Lamiaceae	-	-	−6.9	[23]
Terpene	Curcumin	Mainly in Zingiberaceae	Curcuma longa, Curcuma mangga, Zingiber officinale	11.9	−6.5	[23,117]
Terpene	Parthenolide	Asteraceae, Magnoliaceae, and Celastraceae plant families	-	-	−6.0	[23]
Meroterpenoid	Illicinone A	Illiaceae	Illiciumverum	-	−5.0	[23]
Meroterpenoid	Piperitenone	Labiatae and Poaceae	Mentha spp.	-	−4.3	[23]
Cyclic monoterpene	Limonene	Widely distributed in various plant families	Citrus aurantium, Citrus aurantifolia, Citrus bergamia, Citrus grandis, Citrus junos, Citrus latifolia, Citrus limettioides, Citrus limon, Citrus medica, Citrus paradisi, Citrus reticulata, Citrus sinensis, Zanthoxylum armatum, Allium sativum, Anacardium occidentale, Mangifera indica, Monodora myristica, Xylopia aethiopica, Cuminum cyminum. Foeniculum vulgare, Petroselinum crispum, Porophyllum ruderale, Beta vulgaris, Ocimum basilicum, Thymus piperella, Acca sellowiana, Psidium guajava, Averrhoa carambola, Piper nigrum Prunus avium, Coffea arabica, Coffea canephora, Citrus aurantifolia, Curcuma amada, Curcuma longa	-	−5.2	[113]
Cyclic monoterpene	Sabinene	Labiatae, Cupressaceae, Myristicaceae, and Pinaceae plant families	-	-	−4.8	[113]
Bicyclic monoterpene	Pinene	Widely distributed in various plant families	Piper nigrum, Allium sativum, Anacardium occidentale, Mangifera indica, Pistacia vera, Monodora myristica, Cuminum cyminum, Foeniculum vulgare, Petroselinum crispum, Ocimum basilicum, Origanum vulgare, Rosmarinus officinalis, Myristica fragrans, Eriobotrya japonica, Fragaria vesca, Citrofortunella mitis, Citrus aurantifolia, Citrus spp., Curcuma mangga, Curcuma amada, Aframomum melegueta, Solanum lycopersicum, Zanthoxylum armatum,	-	−4.6	[113]
Labdane diterpenoid	Andrographolide	Acanthaceae	-	-	−6.6	[118]
Triterpene	1β-hydroxyaleuritolic acid 3-p-hydroxybenzoate	Euphorbiaceae	-	-	−8.5	[119]
Steroidal lactone	Withaferin A	Solanaceae	-	-	−9.83	[89]
Tannin	Tannic acid	Ephedraceae and Geraniaceae	-	13.4	−7.5	[120,121]

* KNApSAcK Core System (KNApSAcK DB group (skanayagtc.naist.jp). ** The binding energy of Mpro to Lopinavir (−9.1 Kcal/mol) or Nelfinavir (−8.4 Kcal/mol) is given for comparison of this value for herbal compounds [122].