Two new xanthones from Hypericum japonicum and their lipid-lowering activities.

Phytochemical investigation of the aerial part of Hypericum japonicum afforded two new xanthones (1 - 2), together with twelve known compounds (3 - 14). Their structures with absolute configurations were elucidated by analysis of MS NMR and their experimental and calculated electronic circular dichroism spectra. All of the isolated compounds were tested for their lipid-lowering activities. Compounds 10 , 11 , 13 exhibited potent lipid-lowering activities (with LDL-Uptake rates 3.02, 2.68 and 1.99, respectively, compared with vehicle control, which was designated as 1.00) and compounds 2 - 5 showed moderate activities (with LDL-Uptake rates 1.46, 1.41, 1.31 and 1.51, respectively). [Display omitted] • Two new xanthones were isolated from Hypericum japonicum. • Japoxanthone A-B possessed a novel carbon skeleton. • Compounds 10 , 11 , 13 exhibited potent lipid-lowering activities. [ABSTRACT FROM AUTHOR]