XANTHONES OF GENTIANA KOCHIANA, SWERTIA DECUSSATA AND SWERTIA PERENNIS (GENTIANACEAE)

The following xanthones have been isolated from Gentiana Kochiana Perr. and Song.: 1-hydroxy-3,7,8-trimethoxy xanthone (II) (free form), 1,7-dihydroxy-3,8-dimethoxyxanthone (III) (free and as the primeveroside), 1,7,8-trihydroxy-3-methoxyxanthone (V) (free and as a glycoside), 3,8-dihydroxy-1,7-dimethoxyxanthone (IX) (as the primeveroside). V has also been found in Swertia decussata Nimmo. 1,8-dihydroxy-3,7-dimethoxyxanthone (VII) has been isolated from S. perennis L. All are new natural products except II for which a new structure has been proposed and this result leads to a revised structure for swertinin, namely 1,3-dihydroxy-7,8-dimethoxyxanthone (VIII). © 1970.