Antioxidant Constituents from the Fruit Hulls of Mangosteen (Garcinia mangostana L.) Originating in Vietnam

In the course of our search for natural antioxidants, the methanol extract of the fruit hulls of mangosteen (Garcinia mangostana L.) originating in Vietnam was found to exhibit a potent radical scavenging effect. By monitoring the radical scavenging effect, two xanthones, α- and γ-mangostins, were isolated together with (-)-epicatechin, procyanidins A-2 and B-2 as active principles. The antioxidative activity of these two xanthones was measured by the ferric thiocyanate method and it was found that γ-mangostin showed more potent antioxidative activity than BHA and α-tocopherol.