Sucrose esters and xanthones from Polygalakarensium

Using various chromatographic methods, two new sucrose esters, karensucrose A (1) and karensucrose B (2), one new xanthone, karenxanthone (7) along with eight known compounds, 3-(E)-3,4,5-trimethoxycinnamoyl-6′-benzoylsucrose (3), tricornose B (4), glomeratose C (5), tenuifoliside C (6), 1,7-dihydroxyxanthone (8), 1-methoxy-7-hydroxyxanthone (9), 1,7-dimethoxy-6-hydroxyxanthone (10), and wubangziside B (11) were isolated from the roots of Polygala karensium Kurz (Polygalaceae). Their chemical structures were elucidated using spectroscopic and chemical methods and compared with the reported literature. All isolated compounds were evaluated for cytotoxic activity against two human cancer cell lines, human breast cancer (MCF7) and human prostate cancer (PC3) using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Mitoxantrone was used as a positive control with IC50 values of 9.7 ± 1.2 μM (MCF7) and 7.4 ± 1.3 μM (PC3). As the results, compound 8 showed cytotoxic activity on MCF7 and PC3 cancer cell lines with IC50 values of 26.2 ± 2.1 and 22.1 ± 1.7 μM, respectively.