Separation of Five Flavonoids from Aerial Parts of Bunge Using HSCCC and Their Antioxidant Activities.

The aerial parts of Bunge, as the non-medicinal parts, are always discarded during harvesting, resulting in a huge waste of resources and environmental pressure. Due to the high flavonoid content and their antioxidant activities characteristics, the aerial parts of can be developed into natural antioxidants and used in foods. A high-speed counter-current chromatography (HSCCC) method, using a two-phase solvent system composed of -butyl methyl ether/-butanol/acetonitrile/water (3:1:1:20, /), was the first to successfully isolate five flavonoids from the aerial parts of in one attempt, and separately categorized as rutin (), isoquercitrin (), kaempferol-3--α-l-rhamnopyranosyl-(1→6)-β-d-glucopyranoside (), kaempferol-3--β-d-glucopyranoside () and apigenin-7--β-d-glucopyranoside () after identification. The purities of these plant isolates were 97.3%, 99.5%, 92.8%, 98.1% and 98.7%, respectively. All the flavonoids were identified by HR-ESI-MS, 1D and 2D NMR. Compounds and were firstly isolated from the plant of Results from antioxidant assays showed that rutin () and isoquercitrin () had higher antioxidant capacities compared to L-ascorbic acid as the positive control.