High-performance liquid chromatography and LC-ESI-MS method for identification and quantification of two isomeric polyisoprenylated benzophenones isoxanthochymol and camboginol in different extracts of Garcinia species.

A rapid, sensitive and simple reverse-phase high-performance liquid chromatography-electrospray ionization mass spectrometric method has been developed for the identification and quantification of two isomeric polyisoprenylated benzophenones, isoxanthochymol and camboginol, in the extracts of the stem bark, seeds and seed pericarps of Garcinia indica and in the fruit rinds of Garcinia cambogia. The separation of isoxanthochymol and camboginol was achieved on a Perkin Elmer RP(8) column (10 x 2.1 mm with 5.0 microm particle size) using a solvent system consisting of a mixture of acetonitrile-water (80:20, v/v) and methanol-acetic acid (99.0:1.0, v/v) as a mobile phase in a gradient elution mode. The limits of detection and quantification were 5 and 10 microg/mL for isoxanthochymol and 50 and 100 microg/mL for camboginol, respectively. The intra- and inter-day precisions were 2.34 and 3.41% for isoxanthochymol and 3.35 and 3.66% for camboginol. The identity of the two isomeric compounds in the samples was determined on a triple quadrupole mass spectrometer with ESI interface operating in the negative ion mode. The method was used to identify and quantify isoxanthochymol and camboginol in the different extracts of two Garcinia species, Garcinia indica and Garcinia cambogia.