As awareness and consumption of the mangosteen has increased worldwide, so has the need to better understand the fruit’s most prominent phytonutrient, xanthones. After all, the mangosteen fruit has nature’s most concentrated source of xanthones.
To establish a rapid, dependable approach for identifying xanthones in their naturally occurring state, researchers were asked to develop a credible, easily duplicable analytical method for testing and measuring xanthones in the rind of the mangosteen fruit, Garcinia mangostana. The whole mangosteen fruit rind was chosen as the standard because its response factor is similar to many of the naturally occurring xanthones.
The peer-reviewed, single lab validated High Performance Liquid Chromatography (or HPLC) analysis of selected xanthones in mangosteen fruit study was published in the June 2007 issue of the Journal of Separation Science. The study utilized AOAC protocols. AOAC International is a not-for-profit scientific association that sets standard methods, allowing consumers to have confidence in analytical results obtained from scientific analysis.
An 80:20 acetone/water mixture was used to extract the xanthones from dried, ground whole mangosteen fruit rind. A total of six xanthones were purified by preparative HPLC, utilizing the same solvent system and UV detection as for the analytical method. Each compound has unique UV absorption spectra that allows for easy identification of the xanthone found naturally in the mangosteen fruit.
The study establishes a credible scientific method for testing and measuring xanthones. Six specific xanthones have been identified, and their relative response factors determined. Although additional xanthones are in the process of being identified and measured, this research ensures a more consistent and reliable marketing of mangosteen products to consumers relative to xanthone content claims.