From the Manufacturer:
Better than blueberries, more powerful than pomegranate, mangosteen has emerged as nature's premier antioxidant defender. Throughout most of southeast Asia, mangosteen is known as "the Queen of Fruits" thanks to its excellent taste and health benefits. The secret to its powers lies in its remarkable profile of antioxidant phytonutrients, including polyphenols and xanthones like gamma-mangostin and alpha-mangostin. In fact, Mangosteen is one of the most antioxidant-rich fruits on earth, with an ORAC rating several times higher than blueberry, pomegranate and even wolfberry.