1,8-Dihydroxy-3,6-dimethoxyxanthone

The xanthones in the ethyl acetate extract of Comastoma pedunlulatum were investigated. The chromatographic and spectroscopic techniques were used to isolate and identify the constituents. Nine xanthones were isolated from the active parts of the ethyl acetate portion of the 70% ethanolic extract of C. Pedunlulatum, which possess the protective activity against hepatocyte damage caused by DL-GalN, and identified as 1,8-dihydroxy-2,6-dimethoxyxanthone (1), 8-hydroxy-1,2,6-trimethoxyxanthone (2), 1,6,8-trihydroxy-2-methoxyxanthone (3), 1,8-dihydroxy-3,5-dimethoxyxanthone (4), 1-hydroxy-3,5,8-trimethoxyxanthone (5), 1 -hydroxy-3,7-dimethoxyxanthone (6), 1,2,6,8-tetrahydroxyxanthone (7), 1,3,7-trihydroxy4- methoxyxanthone (8), 6,8-dihydroxy-1, 2-dimethoxyxanthone (9). Among them, compounds 6-9 were isolated from the genus Comastoma for the fist time.

Objective: To study the chemical constituents of Swertia mussotii. Methods: The constituents were isolated by various column chromatography methods, and their structures were identified by physico-chemical properties and spectral analysis. Results: Eleven compounds were isolated and identified as 1,3, 8-trihydroxy-7-methoxyxanthone (I), 2,8-dihydroxy-1,6-dimethyoxyxanthone (II), 1,8-dihydroxy-2,6-dimethoxyxanthone (III), 1,2,8-trimethoxyxanthone (IV), 1,3,5,6-tetrohyroxyxanthone (V), 1,8-dihydroxy-3,7-dimethoxyxanthone (VI), beta-daucosterol (VII), clerosterol 3beta-O-[6'-o-hydro-benzene-beta-D-glucoside] (VIII), ursolicacid (IX), 3beta,28-dihydroxylup-20 (29) -ene (X), erythrocentaurin (XI). Conclusion: Compounds VIII, IX and X are isolated from Swertia mussotii for the first time.