White Willow Bark Extract Details Product Name: White Willow Bark Extract Herb Source: Salix alba L.  Part Used: Bark Active Ingredient: Salicin  Appearance: Brown to White Powder Specification: 15%, 25%, 50%, 80%, 98%  Test Method: HPLC  CAS#: 138-52-3  Salicin Molecular Formula & Molecular Weight: C13H18O7; 286.28 Salicin Structural Formula: Pharmacology: Salicin is the active ingredient of White Willow Bark P.E.. It will be …