Two xanthones from roots of Cratoxylum formosanum

From the roots of Cratoxylum formosanum, two new xanthones, 2,7-dihydroxy-1,8-dimethoxyxanthone and 1,4,7-trihydroxy-8-methoxyxanthone, were isolated, in addition to seven known xanthones and two flavonoids. Among the xanthones, 1,4,7-trihydroxyxanthone was the first isolation from the natural sources. Structures were determined by spectral analyses.