Mangostin (M), a naturally occurring xanthone in the rinds of the fruits of Garcinia mangostana Linn. (Guttiferae) and its derivatives such as 3-0-methyl mangostin (MM), 3,6-di-O-methyl mangostin (DM), 1-isomangostin (IM), mangostin triacetate (MT), mangostin 3,6-di-O-(tetra acetyl) glucoside (MTG)