Tyrosinase Inhibitory Properties of Compounds Isolated from Artocarpus integer Roots

A comprehensive phytochemical investigation of Artocarpus integer root extract led to the isolation of two new geranylated xanthones (1 and 2), one new geranylated flavone (3), one new flavanone (4), and one unique benzopyran (5), along with 16 known compounds. Structures of the new compounds were elucidated by a combination of spectroscopic and computational methods. Two different types of compounds, flavone 12 and arylbenzofuran 19, displayed the most potent antityrosinase activity with IC₅₀ values of 1.7 ± 0.2 and 1.2 ± 0.1 μM, respectively. In addition, kinetic measurements and molecular docking simulations of compounds 12 and 19 were performed and revealed that compound 12 is a competitive inhibitor binding with the tyrosinase active site, while compound 19 is a noncompetitive tyrosinase inhibitor binding the enzyme at the allosteric site.