XANTHONES FROM CELL CULTURES OF HYPERICUM GNIDIOIDES SEEM.

Oxygenated and prenylated xanthones were isolated from the cell cultures of Hypericum gnidioides Seem. when grown in modified B5 medium in the dark. Based on the spectral methods, the structure of the isolated compounds were elucidated as 1,7-dihydroxyxanthone (euxanthone), 1,3,7-trihydroxyxanthone, 1,3,5,6-tetrahydroxyxanthone, 1,3,6,7-tetrahydroxy-8(3-methylbut-2-enyl) xanthone and 1,3,6,7-tetrahydroxy-2,8-di(3-methylbut-2-enyl) xanthone (  -mangostin). The occurrence of both 1,7-dihydroxyxanthone and 1,3,7- trihydroxyxanthone which is recorded for the first time in cell cultures of Hypericum species indicate the presence of a reductase activity responsible for eliminating the 3-hydroxy group and confirm the biosynthetic pathway of xanthones in Hypericum species respectively.