On the Xanthone Glycosides and Flavonoid Glucoside from Swertia franchetiana H. Smith Glycoside constituents from Swertia franchetia na Studies on chemical constituents of root of Polygala tenuifolia (Yuanzhi) Ⅰ Xanthone glycosides from Tibetan herb Halenia elliptica Determination of active constituents in fifteen species Swertia of genus by high performance liquid chromatography Glycosides from Swertia erythrosticta