From Phytochemicals.info on Mangosteen:

Other names:	Mangosteen Garcinia mangostana Mangis, mangu, mangostan, mangostanier, mesetor, semetah
Description:	The mangosteen tree reaches on average an height of 15 meter but can grow as high as 30 meter. Mongosteen tree is rather slow growing and forms a pyramidal crown. The bark is very dark coloured and flaking. The thick dark green leathery mangosteen leaves are evergreen and opposite positioned. Flowers are about 5 cm large and contain four leaves. The dark purple coloured mangosteen fruits reach a size of about 7 cm. Inside the mangosteen fruit are 4 to 7 triangular segments containing juicy white flesh and seeds. The juice is sweet and slightly acid with a delicious flavour.
Parts used:	Mainly to mangosteen fruits are used, but also the leaves, bark and rind.
Phytochemicals:	Mangosteens contain following phytochemicals: Catechins, Rosin, Mangostin, Normangostin, Xanthones, Gartanin,
Medicinal properties:	The dried mangosteen rind is use to treat dysentery, diarrhoea and gonorrhoea. Made into an ointment, mangosteen rind powder is used to treat skin disorders such as eczema and other skin disorders. Mangosteen pulp and rind contains many antioxidant which may have anti-tumor activity. Mangosteen also appears to have anti-inflammatory properties. Studies have demonstrated that prenylated xanthones can help to treat tuberculosis. Of the xanthones tested, alpha- , beta-mangostins and garcinone B had the strongest inhibitory effect against mycobacterium, which causes tuberculosis.
Other facts:	The mangosteen originates from the Sunda Islands and the Moluccas. Most of the mangosteens are grown are harvested in the Far East, mainly in Thailand, Vietnam, China and Taiwan. It takes about 15 years before the mangosteen tree fruit bears fruits. Mangosteen fruit does not ripen well after harvesting, so it should be harvested when ripe or almost ripe. It is usually eaten fresh but it can be stored for a few weeks.
Research Reviews:	Inhibitions of histamine release and prostaglandin E2 synthesis by mangosteen, a Thai medicinal plant.
Abstracts:	Anticancer activity of Mangosteen Effect of Mangosteen on inflammation and allergy More at MyMangosteen.com