2-Arylbenzofuran and tyrosinase inhibitory constituents of Morus notabilis.

Phytochemical investigation of the stem of Morus notabilis led to the isolation and characterization of 10 compounds of 2-arylbenzofurans (1-10), including two new compounds, (2'R)-2',3'-dihydro-2'-(1-hydroxy-1-methylethyl)-2,6'-bibenzofuran-6,4'-diol (1) and 5,6-dimethoxy-2-(3-hydroxy-5-methoxyphenyl)benzofuran (2). Moracins O (6) and P (10) showed inhibitory effects on mushroom tyrosinase with IC50 values being lower than that of kojic acid.