Aim: To study the active constituents of Swertia davidi Franch.
Methods: Column chromatographies on silica gel, Sephadex LH-20 and Diaion-201 et al. were used to isolate and purify the chemical components. Their structures were identified by UV, IR, MS, NMR and 2D-NMR.
Results: These compounds were elucidated as 8-O-beta-D-glucopyranosyl-1, 3, 5-trihydroxyxanthone (I), 5-O-beta-D-glucopyranosyl-1, 8-dihydroxy-3-methoxyxanthone (II), 5-O-beta-D-glucopyranosyl-1, 3, 8-trihydroxyxanthone (III) and swertamarin (IV).
Conclusion: Compound III is a new xanthone glucoside. The other compounds were isolated from this plant for the first time.