Radical Scavenging Evaluation of Green Tea Extracts

The free radical scavenging activity of Thea sinensis leaf extract was evaluated with a chemical test involving diphenylpicrylhydrazyl radical (DPPH). The hot aqueous green tea extract demonstrated antiradical activity comparable with rutin and vitamin E used as a standard. Liquid–liquid fractionation monitored by scavenging radical bioassay followed by preparative high pressure liquid chromatography led to catechin derivatives. The antiradical activity of the main component of tea leaves was identified as epigallocatechin gallate the major component demonstrating activity.