Product Name:Butterbur Extract CAS No:26577-85-5 Color:Brown yellow powder Purity:99%  Active ingredient :Petasin. The Butterbur (Petasites japonicus) has been a staple of the Japanese diet for many years and is one of the few vegetables native to Japan. Besides being recognized for its value as a staple food item it has also demonstrated anti-allergenic properties in recent studies and clinical trials. …