Potential inhibitors of platelet aggregation from plant sources, V. Anthraquinones from seeds of Cassia obtusifolia and related compounds.

Three anthraquinone glycosides, gluco-obtusifolin [11], gluco-chryso-obtusin [15], and gluco-aurantioobtusin [13], were found to be platelet anti-aggregatory constituents of seeds of Cassia obtusifolia. Various other anthraquinone analogues were also tested, and their structure-activity relationships are discussed.