Prenylated Xanthone and Rubraxanthone with Antiplatelet Aggregation Activity in Human Whole Blood Isolated from Garcinia griffithii

Phytochemical studies on the methanolic extract of the leaves of Garcinia griffithii (Guttiferae) afforded two known xanthones derivatives, 1,3,5,6-Tetrahydroxy-7-(3-methylbut-2-enyl)xanthone (1) and Rubraxanthone (2). The structures of these xanthones derivatives were determined on the basis of extensive spectroscopic data interpretation and comparison with data reported in the literature. In an in vitro test, compound 1 and 2 showed the ability to inhibit platelet aggregation in human whole blood which induced by arachidonic acid (AA), adenosine diphosphate (ADP) and collagen.