儿茶素
Catechins are secondary metabolites from plants belonging to the group of flavan-3-ols (or simply flavanols), part of the chemical family of flavonoids. (+)-Catechin and (-)-epicatechin as well as their gallic acid conjugates are ubiquitous constituents of vascular plants, and are mostly found as cacao and tea constituents, as well as in Vitis vinifera grapes. Catechins and their derivatives are a type of natural phenol and antioxidant and are thought to contribute to the beneficial effects ascribed to catechin-containing remedies, such as green tea.