title: Chemical constituents of gentianaceae XXIII: tetraoxygenated and pentaoxygenated xanthones and xanthone O-glucosides of Swertia angustifolia Buch.-Ham.
abstract: The whole plant extract of Swertia angustifolia Buch.-Ham., collected at different stages of growth, contained 14 tetraoxygenated and five pentaoxygenated xanthones and xanthone 1-O-glucosides. Of the eight xanthone 1-O-glucosides isolated, five were previously unreported in nature. The xanthones are broadly based on 1,3,5,8- and 1,3,7,8-oxygenated systems, with an added oxygen function at C-4 in some compounds, and represent a number of methoxylated patterns. The content and relative abundance of the free xanthones and their 1-O-glucosides changed with plant growth. These results are the first demonstration of the variation in chemical characters in the different parts of a Swertia species during its ontogeny. The biolgocial significance of these results is appraised.
mesh_terms: D005960:Glucosides / Q000032:analysis / Q000302:isolation & purification; D008722:Methods; D010946:Plants, Medicinal / Q000032:analysis* / Q000254:growth & development; D014966:Xanthenes / Q000032:analysis* / Q000302:isolation & purification
chemical_list: D005960:Glucosides; D014966:Xanthenes