Abstract:To understand the chemical composition of Hedyotis diffusa, nine compounds were isolated from the 70% ethanol extract by column chromatography on silica gel and preparative high-performance liquid chromatography. Based on physicochemical properties and spectral data, their structures were identified as stigmasterol (1), β-sitosterol (2), rubiadin (3), 2,6-dihydroxy-1-methoxyanthraquinone (4), β-sitosterol-3-O-β-d-glucoside (5), p-coumaric acid (6), kaempferol (7), quercetin (8) and 2-hydroxy-3-methoxy-7-methylanthraquinone (9). Compound 4 was a new compound. The Fr.4, Fr.4-2 and Fr.4-4 fractions in chloroform extract had strong activity against human endometrial carcinoma Ishikawa cells in vitro, with IC50 of 52.8, 78.1 and 27.5 μg/mL, respectively.
