Assessing the biological activities of xanthone derivatives from Swertia macrosperma C.B. Clark

The anti-microbial and anti-oxidant effects of xanthones extract from Swertia macrosperma C.B. Clark were investigated using extracts from whole plant and partitioned by petroleum ether, ethyl acetate and n-butanol, respectively. Anti-microbial and anti-oxidant activities were detected among different fractions. High-performance liquid chromatography was performed to separate and purify the elutions. The compounds were elucidated by 1H, 13C NMR and LCMS. The ethyl acetate extract showed maximum inhibitory activity in fungal organisms and Gram-positive bacteria, and had the highest anti-oxidant capacity. Eight xanthones were isolated in ethyl acetate fraction from S. macrosperma. Moreover, compounds IV-VI and VIII were isolated from the plant for the first time, and compound VII had the strongest anti-oxidant effect.