Kinase inhibitors from Polygonum cuspidatum.
J Nat Prod. 1993 Oct;56(10):1805-10. PMID: 8277318
Department of Medicinal Chemistry and Pharmacognosy, School of Pharmacy and Pharmacal Sciences, Purdue University, West Lafayette, Indiana 47907.
Bioassay-directed fractionation of a medicinal plant, Polygonum cuspidatum (Polygonaceae), has led to the discovery of a hydroxystilbene, resveratrol , as an inhibitor of a protein-tyrosine kinase (p56lck) partially purified from bovine thymus. Both trans and cis isomers of resveratrol possess comparable protein-tyrosine kinase inhibitory activity. Comparison of the IC50 values of resveratrol for protein-tyrosine kinase inhibitory activity with those of piceid (resveratrol-O3-beta-glucoside)  and resveratrol-O4'-beta-glucoside  shows the requirement of free hydroxyl groups on both phenyl rings for the protein-tyrosine kinase inhibition. Protein kinase C inhibitory analysis suggests the requirements of two free hydroxyl groups on one phenyl ring only.