Table 3.

Antiviral effect of FA derivatives.

Derivative	General structure	Virus	Antiviral activity/Cytotoxicity of the compound	Structure	References
Chemically synthesized
FA polymers		HIV-1	IC50 = 1.0 μg/ml IC50 = 0.9 μg/ml IC50 = 2.7 μg/ml IC50 = 3.2 μg/ml	>30 kDa 30–10 kDa 10–1 kDa 1 kDa−500 Da	(104)
	Example: diferulate, triferulate
FA amide of 3-aminomethyl glaucine		HRV-14	IC50 = 12.00 μM CC50= 113 μM	-	(105)
FA amides		TMV	40.7% protective effect 46.4% curative effect	R1: n-Pr; R2: H R3: propynyl	(106)
Hydrogenated FA amides		TMV	27.3% protective effect 30.4% curative effect	R1: Me R2: p-Cl R3: propynyl	(106)
		TMV	15.2% protective effect 28.9% curative effect	R1: p-benzyloxy R2: propynyl	(107)
α,β-unsaturated amide derivatives of FA with an α-aminophosphonate moiety		TMV	EC50 = 180.37 μg/ml (protective effect)	R1: 4-Cl	(108)
			EC50 = 285.42 μg/ml (curative effect)	R2: 4-CF3-Ph
		CMV	EC50 = 216.30 μg/ml (protective effect)
			EC50 = 284.67 μg/ml (curative effect)
Trans-FA derivatives containing acylhydrazone moiety		TMV	18.8% curative effect	R1: PhCH2	(109)
			23.0% protective effect	R2: 2-Th
			94.2% inactivating effect
			EC50 = 36.59 μg/ml
FA sulfonamides		TMV	39.8% curative effect	R1: -C2H5	(110)
			59.7% protective effect 87.3% inactivating effect	R2: 4-NO2-Ph
			EC50 = 84.80 μg/ml
Myricetin derivatives with an FA amide scaffold		TMV	55.5% curative effect 53.3% protective effect EC50 = 472.4 μg/ml	R: 4-Br, n = 3	(111)
FA 3-amino derivatives/esters		H1N1	IC50 =90.0 μg/ml	R1: CH2(CH3)	(78)
				R2: CH(CH3)2
				R3: NO2
FA derivatives with a quinazoline moiety		TMV	60.8% curative effect	R1: 2-OCH3-Ph	(112)
			78.2% protective effect	R2: 4-oxoquinazolin-3(4H)-yl-methyl
			90.8% inactivating effect
		CMV	58.1% curative effect	R1: 2-OCH3-4-allyl-Ph
			69.8% protective effect
				R2:4-oxoquinazolin-3(4H)-yl-methyl
			78.2% inactivating effect
Trans-FA esters with a chalcone group		TMV	63.9% curative effect	R: Me	(113)
			64.6% protective effect	Ar: 2-F-Ph
			92.3% inactivating effect
			EC50 = 214.20 μg/ml
FA derivatives containing dithioacetal moiety		TMV	62.7% curative effect	R1: 3-OCH3-4-OCOCH3	(114)
			52.3% protective effect
			73.8% inactivating effect	R2: 2-OCH3
			EC50=73.7 μg/ml	R3: -(CH2)2OH
		TMV	62.5% curative effect	R1: 3-OCH3-4-OCOCH3
			61.8% protective effect	R2: H
				R3: -(CH2)2OH
			83.5% inactivating effect
			EC50= 50.7 μg/ml
		TMV	48.% curative effect	R1: H
			48.% protective effect	R2:H
			53.% inactivating effect
			EC50=355.6 μg/ml
Enzymatically synthesized
FA rutinoside		FCV	40% increase of cell viability	–	(117)
FA β-sitosterol ester		SARS-CoV-2	Binding energy = −7.8 kcal/mol (molecular docking simulation with SARS-CoV-2 3CLpro)	–	(127)
					(128)

HIV, human immunodeficiency virus; HRV, human rhinovirus; TMV, tobacco mosaic virus; CMV, cucumber mosaic virus; H1N1, influenza A virus subtype; FCV, feline calicivirus; SARS-CoV-2, severe acute respiratory syndrome coronavirus; EC₅₀, half-maximal effective concentration; the concentration required to obtain a 50% inhibitory effect; IC₅₀, half-maximal inhibitory concentration; the concentration at which the number of viral plaques is reduced by 50%; CC₅₀, half-maximal cytotoxicity concentration, the concentration that reduced cell viability to 50% of the control.