|
|
|
|
Molecular Pharmacology, Vol 16, 556-568, Copyright © 1979 by the American Society for Pharmacology and Experimental Therapeutics
1 Department of Genetics and Department of Pharmacology, Stanford University School of Medicine,
Stanford, California 94305
A series of 45 flavonoids and related compounds were tested as inhibitors of liver fluke cyclic nucleotide phosphodiesterase. Many were found to be potent inhibitors; seven were as potent or more potent than any inhibitor previously tested. The kinetics of six compounds spanning a wide range of activities were investigated and found to be competitive. The most potent inhibitors, cyanidin chloride and quercetin, had Ki values of 10 ± 3 µM and 13 ± 6 µM, respectively, approaching the Km for CAMP (8 µM). Structure/ activity studies showed that adding exocyclic substituents to the basic flavonoid skeleton affected activity only slightly, while changing the planarity of the heterocyclic ring greatly decreased activity. This observation, taken with the competitive kinetics, suggests that flavonoids compete with cAMP for a nucleotide binding site at which stacking occurs, perhaps similar to the binding sites of bovine pancreatic ribonuclease A and lobster glyceraldehyde-3-phosphate dehydrogenase. Quantum chemical calculations further suggest that the competition arises from the mimicking of the pyrimidine ring in cAMP by the pyranone ring of the flavonoids. If the flavonoids are comparably potent inhibitors of other phosphodiesterases, several reported pharmacological effects of the flavonoids might be explained.
Note:
ACKNOWLEDGMENTS
The cooperation of Dr. Martin Apple of the University of California, San Francisco, in providing many
of the flavonoids and in helpful discussions is gratefully
acknowledged. Also acknowledged are helpful discussions with Dr. Fred Fuhrman, Hopkins Marine Laboratory, and Drs. John Thomas and Oleg Jardetzky of
Stanford University.
This article has been cited by other articles:
![]() |
M. R. Peluso Flavonoids Attenuate Cardiovascular Disease, Inhibit Phosphodiesterase, and Modulate Lipid Homeostasis in Adipose Tissue and Liver Experimental Biology and Medicine, September 1, 2006; 231(8): 1287 - 1299. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. Casani, E. Segales, G. Vilahur, A. B. de Luna, and L. Badimon Moderate Daily Intake of Red Wine Inhibits Mural Thrombosis and Monocyte Tissue Factor Expression in an Experimental Porcine Model Circulation, July 27, 2004; 110(4): 460 - 465. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. Middleton Jr., C. Kandaswami, and T. C. Theoharides The Effects of Plant Flavonoids on Mammalian Cells:Implications for Inflammation, Heart Disease, and Cancer Pharmacol. Rev., December 1, 2000; 52(4): 673 - 751. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. S. Demrow, P. R. Slane, and J. D. Folts Administration of Wine and Grape Juice Inhibits In Vivo Platelet Activity and Thrombosis in Stenosed Canine Coronary Arteries Circulation, February 15, 1995; 91(4): 1182 - 1188. [Abstract] [Full Text] |
||||