... water, soluble in aether, chloroform, ethanol, acetic acid and acetone.Appearance: Fine crystal powderColor: White Specific Rotation : ... called stilbenes , found largely in the skins of red grapes and root of Polygonum cuspidatum Sieb. et Zucc ( Japanese ... most abundant natural sources are Vitis vinifera, labrusca, and muscadine grapes, Polygonum cuspidatum Sieb. Cardiovascular Effects Cancer-Related ...