Certain proanthocyanidins found in various wines, grape juice, and other plant extracts exhibit endothelium-dependent vasorelaxing activity that involves increased nitric oxide production by endothelial cells. The smallest procyanidins (PCs) possessing substantial EDR activity were isolated from grape seeds. A dimer di-gallate (epicatechin-galloyl-epicatechin-gallate) was purified from concord grape seed extracts by Toyopearl TSK-40 gel chromatography, HPLC and electrospray FTMS. Further characterization was achieved using tannase treatment and acid thiolysis. This compound had an EC50 for vasorelaxation of 0.67.+-.0.04 .mu.g/ml when tested for endothelium-dependent relaxing activity in phenylephrine pre-contracted rat aortic rings.
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. application Ser. No. 10/065,770 filed Nov. 18, 2002 now U.S. Pat. No. 6,706,756, which claimed priority to U.S. Provisional Application No. 60/332,428 filed Nov. 16, 2001. The disclosures of which are hereby incorporated by reference in their entireties.
