Noun
One of the tannic acids, extracted from catechu as a white, crystalline substance; -- called also catechuic acid, and catechuin.
Source: Webster's dictionaryAs already hinted above, green tea supplements are often made with concentrated polyphenol or catechin extracts. Source: Internet
EGCg, which is a type of catechin, comprises of almost 60% of the entire volume of catechins in Matcha green tea. Source: Internet