Liquid chromatography-tandem mass spectrometry method for identification and quantification of two biologically active polyisoprenylated benzophenones, isoxanthochymol and camboginol, in Garcinia species

A sensitive liquid chromatography/electrospray ionization tandem mass spectrometrical (LC/ESI-MS/MS) method was developed for simultaneous identification and quantification of two polyisoprenylated benzophenones, isoxanthochymol and camboginol, in the extracts of the fruit rinds, stem bark, seed and leaves of Garcinia indica and in the fruit rinds of Garcinia cambogia. The separation of isoxanthochymol and camboginol was achieved on an RP-8 column using the solvent system consisting of a mixture of acetonitrile-water (80:20) and methanol-acetic acid (99.0:1.0) as a mobile phase in a gradient elution mode. A multiple reaction monitoring (MRM) method was developed for quantification of isoxanthochymol and camboginol in the above extracts of Garcinia species. Based on a signal-to-noise ratio of 3, the limits of detection in MRM mode for isoxanthochymol and camboginol were 2.0 and 5.0 ng/mL respectively. The method was validated in terms of linearity, accuracy and precision for 6 days. The method developed was found to be useful for identification and quantification of isoxanthochymol and camboginol in the extracts of the fruit rinds, stem bark, seed and leaves of Garcinia indica and in the fruit rinds of Garcinia cambogia.