If by hearing the name of the fruit Mangosteen, you take it to be a relative of those juicy mangoes; you are probably in the wrong direction. Mangosteen though is a highly beneficial fruit and is nowhere about the mangoes.
Mangosteen is a purplish-tinted fruit that acknowledges the natives of Sunda Island and the Indonesians for its discovery. With its utter sweet taste and remedial abilities, this fruit slowly reached many other countries such as China, Cambodia and other South-Asian countries. It is now a popular fruit in North America too.
As you move in, Mangosteen Fruit displays as succulent, white-coloured flesh that has few seeds inside. This flesh of the fruit is one of the rare parts, which contain the antioxidants ‘Xanthones’.

What Are Xanthones? 
Xanthones are the plant-based nutrients, also known as phytonutrients. The discovery of Xanthones was made as late as 1855 by a German Scientist who was performing research on dysentery. These yellow-coloured pigments occur in some other fruits too, but their concentration is the greatest on epicarp of the Mangosteen Fruits.

Role of Xanthones in the human body:
Xanthones are the highly beneficial kind of antioxidants that play some major supportive roles. These antioxidants perform their activities at the cellular levels and strengthen the cell walls. Also, they inhibit the attack of free radicals that are bent to damage the cells.Xanthones could also prove helpful in keeping the joints flexible, maintain the healthy lungs and preventing many kinds of inflammations and allergies. 

Other Benefits of Xanthones in the human body:
While the perishable nature of mangosteen fruit does not allow it to get transported to the whole of the world, you could derive the benefits of the fruits from the Mangosteen Juice. Mangosteen Juice is the liquid extract of the fruit that gets derived out of fresh and ripe mangosteen fruits.This fruit juice contains the same amount of Xanthones as the original fruit and could be used as a liquid supplement with benefits such as:

Prevention of Cancer:
The Xanthones that are an integral part of the mangosteen juice could be highly helpful in inhibiting the effects of free radicals and thereby, they could play supportive roles in the prevention of development of cancers in the human body.

According to some studies at ‘Gifu International Institute of Biotechnology’ in Japan, Xanthones in the Mangosteen Juice could prevent the development of leukaemia cells in the body. (Source: http://www.livestrong.com/article/323087-what-are-the-benefits-of-xanthones/

Protection From Inflammations: 
Xanthones are also the potent antioxidants that help in preventing inflammation in the human body, and it has been revealed in many kinds of researches. These inflammations could be due to internal and external causes in the body and are effectively checked and suppressed by these antioxidants.

Heart Protection:
The Xanthones present in the Mangosteen Juice has the potential to strengthen the heart muscles and thereby disable possibilities of strokes, heart failures and cardiac arrests.Therefore, we can effectively conclude that Xanthones are highly beneficial antioxidants that serve many kinds of function for the human body. If you too wish to receive the benefits, include mangosteen juice in your diet and protect your body from various disease attacks.