Chemical structures of natural flavonols and IC₅₀ values obtained against mushroom tyrosinase.

Compound no.	Compound name	Chemical structures	IC50 values (μM)	Reference
139	Quercitin		10.73	58
140	Kaempferol		5.5	71
141	Galangin		3.55	38
142	Rutin		130	101
143	2-(3,4-Dihydroxyphenyl)-3,5,7-trihydroxy-4H-chromen-4-one		53.4	31
144	2-(3,4-Dihydroxyphenyl)-3,5-dihydroxy-7-methoxy-4H-chromen-4-one1		72.5	31
145	6-Hydroxykaempferol		124	31
146	6-Hydroxygalangin		182	31
Standard	Kojic acid		318	31, 38, 58 and 71