Chemical constituents and biological studies of Origanum vulgare Linn

Bioassay-guided isolation of methanolic extract of the leaves of Origanum vulgare Linn., yielded two protocatechuic acid ester derivatives, origanol A (1) and origanol B (2) along with ursolic acid (3), oleanolic acid (4), beta-sitosterol (5), and triacontanol (6). Structures of the compound were established based on physical and spectral data (UV, IR, H-1 and C-13 NMR and mass). Origanol A (1) showed significant mushroom tyrosinase inhibition activity.