Effect of Depigmentation for 3,4-di-O -Caffeoylquinic Acid Guided by Tyrosinase Inhibitory Activity from Conyza filaginoides

Abstract

Examination of a water extract of Conyza filaginoides guided by tyrosinase inhibitory activity afforded twelve compounds including five phenylpropanoids, three flavonoids, two nucleic acids and two icarisides. Among them, four compounds, 3,4-di-O -caffeoylquinic acid 3, 4-O -caffeoylquinic acid 4, chlorogenic acid 5 and rutin 8 showed strong inhibitory activities with IC₅₀s of 57.7, 393.7, 273.2 and 113.7 μM, respectively, and their inhibition modes were noncompetitive. The whitening effect of the most effective compound 3 was also examined, and it showed distinct depigmentation against UVB-irradiated skin of browm guinea pig (the depigmentation percentage was 30.8%).