Fig. 3. Chemical structure of gallic acid and the four major catechins in green tea. GA, gallic acid; EGCG, ()-epigallocatechin-3-gallate; EGC, ()-epigallocatechin; ECG, ()-epicatechin-3-gallate; EC, ()-epicatechin.
Fig. 4. Mean content of gallic acid and catechins in different types of tea (n = 45). Data refereed to dry weight of commercial samples (Source: Cabrera et al. [22]).