Qualitative evaluation and quantitative determination of 10 major active components in Carthamus tinctorius L. by high-performance liquid chromatography coupled with diode array detector

Flavonoids in the water extract of Carthamus tinctorius L. exhibit potent biological activities such as anti-coagulant, vasodilation, anti-oxidant, neuroprotection and immunosuppressant. A high-performance liquid chromatographic method was established to evaluate the quality of Carthamus tinctorius through a simultaneous quantitation of eight flavonoids, hydroxysafflor yellow A (2), 6-hydroxykaempferol 3,6-di-O-β-glucoside-7-O-β-glucuronide (3), 6-hydroxykaempferol 3,6,7-tri-O-β-glucoside (4), 6-hydroxykaempferol 3-O-β-rutinoside-6-O-β-glucoside (6), 6-hydroxykaempferol 3,6-di-O-β-glucoside (7), 6-hydroxyapigenin 6-O-glucoside-7-O-glucuronide (8), anhydrosafflor yellow B (9), and kaempferol 3-O-β-rutinoside (10), together with two other compounds named guanosine (1) and syringin (5). Among them, compound 8 was identified as a new compound. The compounds were separated on an Alltech Alltima-C18 column with gradient elution of acetonitrile and 0.01% trifluoroacetic acid. The detection wavelength was 280 nm. All the compounds showed good linearity (r2 ≥ 0.9989). The recoveries, measured at three concentration levels, varied from 94.9% to 105.2%. This method was also validated with respect to precision, repeatability and accuracy, and was successfully applied to quantify the 10 components in 46 batches of C. tinctorius samples from different areas. Significant variations were found in the contents of these compounds in these samples. Compared with the reported analytical methods of C. tinctorius, this simple and reliable method provided a new basis for overall assessment on quality of C. tinctorius and should be considered as a suitable quality control method.