Complete isolation and characterization of silybins and isosilybins from milk thistle (Silybum marianum)

Org Biomol Chem. 2003 May 21;1(10):1684-9. doi: 10.1039/b300099k.


Complete separation, isolation, and structural characterization of four diastereoisomeric flavonolignans, silybins A (1) and B (2), and isosilybins A (3) and B (4) from the seeds of milk thistle (Silybum marianum) were achieved for the first time using a preparative reversed-phase HPLC method. In addition, three other flavonolignans, silychristin (5) isosilychristin (6) and silydianin (7), and a flavonoid, taxifolin (8) were isolated. Structures, including absolute stereochemistries of 1-4, were confirmed using 2D NMR and CD spectroscopy.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Chromatography, High Pressure Liquid / methods
  • Circular Dichroism
  • Flavonoids / chemistry*
  • Flavonoids / isolation & purification*
  • Lignans / chemistry*
  • Lignans / isolation & purification*
  • Milk Thistle / chemistry*
  • Nuclear Magnetic Resonance, Biomolecular
  • Stereoisomerism


  • Flavonoids
  • Lignans