Emodin, a protein tyrosine kinase inhibitor from Polygonum cuspidatum

J Nat Prod. 1992 May;55(5):696-8. doi: 10.1021/np50083a026.


Bioassay-directed fractionation of a Chinese medicinal plant, Polygonum cuspidatum (Polygonaceae), has led to the discovery of an anthraquinone, emodin [1], as a strong inhibitor of a protein tyrosine kinase (p56lck) partially purified from bovine thymus. Comparison of the IC50 values of emodin for protein tyrosine kinase inhibitory activity with physcion [2] and emodin-O8-D-glucoside [3], also isolated from the same plant, reveal the importance of the hydroxyl groups at C-6 and C-8 for the observed activity.

Publication types

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

MeSH terms

  • Animals
  • Cattle
  • Emodin / isolation & purification
  • Emodin / pharmacology*
  • Lymphocyte Specific Protein Tyrosine Kinase p56(lck)
  • Plants, Medicinal / chemistry*
  • Protein-Tyrosine Kinases / antagonists & inhibitors*


  • Protein-Tyrosine Kinases
  • Lymphocyte Specific Protein Tyrosine Kinase p56(lck)
  • Emodin