It can be found in Melaleuca quinquenervia leaves[1] and in oaks species like the North American white oak (Quercus alba) and European red oak (Quercus robur).
[2] It shows antioxydant activity.
[3] It is also found in wine, red[4] or white,[5] aged in oak barrels.
It is a castalagin glycoside[6] by binding of the pentose lyxose.
It suppresses the phosphorylation of the epidermal growth factor receptor in human colon carcinoma cells.