Anti-ulcer xanthones from the roots of Hypericum oblongifolium Wall.

Three new xanthones, hypericorin C (1), hypericorin D (2) and 3,4-dihydroxy-5-methoxyxanthone (3), along with eight known compounds; 2,3-dimethoxyxanthone (4), 3,4-dihydroxy-2-methoxyxanthone (5), 3,5-dihydroxy-1-methoxyxanthone (6), 3-acetylbetulinic acid (7), 10H-1,3-dioxolo[4,5-b]xanthen-10-one (8), 3-hydroxy-2-methoxyxanthone (9), 3,4,5-trihydroxyxanthone (10) and betulinic acid (11) were isolated from the roots of Hypericum oblongifolium. The structures of the new compounds 1, 2 and 3 were deduced by spectroscopic techniques [ESI MS, (1)H NMR, (13)C NMR, and 2D NMR (HMQC, HMBC, COSY and NOESY)]. The entire series of compounds were evaluated for anti-ulcer activity.