Table 20.

An anti-tyrosinase activity of chalcones.

Substances	Substrate	Positive control (inhibitor)	Type of inhibition	Inhibition constant $K_i$	Source of tyrosinase	The half-maximal inhibitory concentration ${\mathrm{IC}}_{50}\mathrm{ }$(µM)	References
3,4,2′,4′-Hydroxychalcone	L-tyrosine L-DOPA	Kojic acid	NR	NR	Mushroom	${29.3}^{\mathrm{a}}/{>100}^{\mathrm{b}}$	Khatib et al.133
2,4,3′,4′-Hydroxychalcone		Kojic acid	NR	NR	Mushroom	${0.2}^{\mathrm{a}}/{>7.5}^{\mathrm{b}}$	Khatib et al.133
3,4,2′,4′-Hydroxychalcone		Kojic acid	NR	NR	Mushroom	${31.68}^{\mathrm{a}}/{>1000}^{\mathrm{b}}$	Khatib et al.133
2,4,2′,4′-Hydroxychalcone		Kojic acid	NR	NR	Mushroom	${0.02}^{\mathrm{a}}/{90}^{\mathrm{b}}$	Khatib et al.133
2′,4′,6′-Trihydroxychalcone	L-tyrosine	Kojic acid	NR	NR	Mushroom	120	Jun et al.134
2′,4′-Dihydroxychalcone		Kojic acid	NR	NR	Mushroom	NA	Jun et al.134
2′,6′-Dihydroxychalcone		Kojic acid	NR	NR	Mushroom	NA	Jun et al.134
2′,3,4,4′,6′-Pentahydroxychalcone		Kojic acid	NR	NR	Mushroom	193	Jun et al.134
2′,3,4,4′,5,6′-Hexahydroxychalcone		Kojic acid	NR	NR	Mushroom	200	Jun et al.134
2′,3,4,4′,6′-Pentahydroxychalcone		Kojic acid	NR	NR	Mushroom	NA	Jun et al.134
3,3′,4,4′-Tetrahydroxychalcone		Kojic acid	NR	NR	Mushroom	NA	Jun et al.134
2′,3,4-Trihydroxychalcone		Kojic acid	NR	NR	Mushroom	NA	Jun et al.134
2′,4′,6′-Trihydroxy-3,4-dimethoxychalcone		Kojic acid	NR	NR	Mushroom	150	Jun et al.134
2,2′,3-Trihydroxy-4′,6′-dimethoxychalcone		Kojic acid	NR	NR	Mushroom	NA	Jun et al.134
2′,3,4,5,-Tetrahydroxy-4′,6′-dimethoxychalcone		Kojic acid	NR	NR	Mushroom	NA	Jun et al.134
2′,3,4-Trihydroxy-4′,6′-dimethoxychalcone		Kojic acid	NR	NR	Mushroom	NA	Jun et al.134
2,2′,4,4′-Tetrahydroxychalcone		Kojic acid	NR	NR	Mushroom	5	Jun et al.134
2,2′,4,4′-Tetrahydroxy-6′-methoxychalcone		Kojic acid	NR	NR	Mushroom	3.1	Jun et al.134
2,2′,4,4′,6′-Pentahydroxychalcone		Kojic acid	Competitive	3.1	Mushroom	1	Jun et al.134
Licochalcone A	L-DOPA	Kojic acid	Competitive	NR	Mushroom	25.8	Fu et al.136
Licuraside		Kojic acid	Competitive	NR	Mushroom	72	Fu et al.136
Isoliquiritin		Kojic acid	Competitive	NR	Mushroom	38	Fu et al.136

^aL-tyrosine; ^bL-DOPA; NR: non reported; NA: non active