There is considerable interest in botanical supplements due to their purported health benefits. Mangosteen (Garcinia mangostana L) is a tropical fruit that is indigenous to Southeast Asia, where it has been historically used to treat abdominal pain, diarrhea, dysentery, inflammation, wound infection, suppuration, and chroniculcer.1 Recently mangosteen has been proposed as a homeopathic therapy in the treatment of Parkinson’s disease.2 Such therapeutic benefits have been mostly attributed to a unique family of compounds referred to as xanthones that are most abundant in the pericarp of the fruit.3 The structures of the five major xanthones, including α-mangostin, 3-isomangostin, gartanin, 9-hydroxycalabaxanthone, and 8-desoxygartanin, are presented in Figure 1.