Epigallocatechin gallate (EGCG), also known as epigallocatechin-3-gallate is a type of catechin (an organic compound produced by a plant, for example, which is not directly involved in the normal growth, development, or reproduction of the plant) which provides an antioxidant role in plants.
EGCG – the most abundant catechin in tea – is a polyphenol under basic research for its potential to affect human health and disease. (Wikipedia)