ISOLATION FROM WEN-PI-TANG OF THE ACTIVE PRINCIPLES POSSESSING ANTIOXIDATION AND RADICAL-SCAVENGING ACTIVITIES

The active principles of Wen-Pi-Tang possessing antioxidation and free radical-scavenging activities were isolated, and its properties were determined using the thiobarbituric acid-reactive substance (TBARS) pr ocedure and a 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical generating system. Significant inhibitory activities against both the formation o f TEARS and generation of free radicals were shown by fractions 5, 6 a nd 7, which contained mainly polyphenolic compounds and phenolic glyco sides as well as anthraquinone glycosides. The most active compounds w ere procyanidin B-2 3,3'-di-O-gallate, (-)-epicatechin 3-O-gallate, pr ocyanidin B-2 and 1,2,6-tri-O-galloyl-beta-glucose, the former two hav ing been confirmed to be the most active principles of Wen-Pi-Tang in improving renal function. It is suggested that tannins make a prominen t contribution to both the biological activity and pharmacological eff ects of Wen-Pi-Tang.