Research progress on separation and characterization of bioflavonoids from Coreopsis tinctoria Nutt.

Coreopsis tinctoria Nutt (C. tinctoria) or a common name ‘Snow chrysanthemum’ because of its growing condition at high altitude，is one of the popular medicinal-food plants, mainly grows in the northwest area of China. Because of its rich nutrients, particularly polyphenols (majorly flavonoids), and volatile oils among others, C. tinctoria has become a research hotspot in recent years. In addition, the flavonoids of C. tinctoria, especially the flavanomarein, marein, okanin and other bioactive phytochemicals, have effective biological activity. They possess good antioxidant and anti-inflammatory effects, also have significant effects on lowering blood pressure, hypoglycemia and reducing levels of triglycerides and cholesterol. However, at present, studies on the bioactivity of C. tinctoria are mainly focused on crude extracts or total flavonoids. The study of monomer components is largely limited to the isolation and purification process, which is difficult for a systematic study because of the chemical-physical nature of marein, flavanomarein and other compounds in C. tinctoria. Therefore, to have an updated isolation of C. tinctoria bioactive components, this paper reviewed the current research status of the separation and purification methods of flavonoids from C. tinctoria, by analyzing and comparing the technical characteristics of these methods, and providing prospects on the development and application of the separation and purification methods of C. tinctoria.