sentences:  Piceatannol is a metabolite of resveratrol found in red wine, grapes, passion fruit, white tea, and Japanese knotweed .Astringin, a piceatannol glucoside, is also found in red wine.A 1989 "in vitro" study found that piceatannol blocked LMP2A, a viral protein-tyrosine kinase implicated in leukemia, non-Hodgkin's lymphoma and other diseases associated with Epstein-Barr virus.