Preparation of Three Flavonoids from the Bark of Salix alba by High‐Speed Countercurrent Chromatographic Separation

Abstract

The main flavonoids from the bark extract of Salix alba (Salicaceae) were separated on preparative scale using high‐speed countercurrent chromatography (HSCCC). In each separation, 1.0 g crude extract was applied to yield pure eriodictyol (120 mg), 5,7‐dihydroxychromen‐4‐one (29.5 mg), and naringenin (50 mg), respectively, while water–methanol–ethyl acetate–n‐hexane (3:2:2:2, v/v) was used for a two‐phase solvent system. The chemical structures of three flavonoids were elucidated by means of electrospray ionization ion trap multiple mass spectrometry (ESI‐MS–MS), as well as ¹H‐, ¹³C‐, and DEPT‐NMR spectroscopy.

Keywords:

• Salix alba
• Salicaceae
• Flavonoids
• Chromenone
• High‐speed countercurrent chromatography
• Preparative isolation
• ESI‐MS‐MS
• NMR

Acknowledgments

Qizhen Du is grateful for financial support by the “Alexander‐von‐Humboldt Foundation.”