Safflower (Carthamus tinctorius LINNE) has been traditionally used for the treatment of Oketsu, namely blood stasis in Chinese medicine. Aqueous extract from safflower inhibited the rabbit platelet aggregation induced by adenosine diphosphate. The sole inhibitor was isolated by high performance liquid chromatography (HPLC), and identified as adenosine by 13C- and 1H-nuclear magnetic resonance. As the result of quantitative analysis by HPLC using the capsule type C18 column, 16-550 ppm of adenosine were detected in safflowers collected from different districts.
