A new xanthone as a chemical marker of four Polygala species (Polygalaceae).

A new xanthone, 1,5-dihydroxy-2,3-methylenedioxyxanthone ( 1 ), was isolated from four species of Polygala ( Polygala campestris, Polygala densiracemosa, Polygala linoides and Polygala pulchella ). In addition, three other xanthones and one sterol were isolated from extracts of these species: 1,5-dihydroxy-2,3-dimethoxyxanthone ( 2 ), 1,5-dihydroxy-3-methoxyxanthone ( 3 ), 1,5-dihydroxy-6′,6′dimethylpyrano[2′,3':3,2]xanthone ( 4 ) and α-spinasterol ( 5 ). The xanthone 1 is new in the literature and although the others are known compounds this is the first time they have been isolated from these species. The chemotaxonomic significance of these data for the Polygala genus is reported. [ABSTRACT FROM AUTHOR]