Quantitative determination of xanthorrhizol in rat plasma by HPLC-MS/MS and its application to a pharmacokinetic study.

Although xanthorrhizol, a sesquiterpenoid oil isolated from the rhizoma of Curcuma xanthorrhiza Roxb. known as Java turmeric, represents a variety of pharmacological activities, to date, there have been no validated determination methods of xanthorrhizol in biological samples. Thus, we developed a liquid chromatographic method using a tandem mass spectrometry for the determination of xanthorrhizol in rat plasma. After simple protein precipitation with acetonitrile including diclofenac (internal standard, IS), the analytes were chromatographed on a reversed-phased column with a mobile phase of 20mM ammonium acetate aqueous solution and acetonitrile (20:80, v/v). The ion transitions of the precursor to the product ion were principally deprotonated ions [M-H]- at m/z 216.9→132.8 for xanthorrhizol and 296.1→251.7 for the IS. The accuracy and precision of the assay were in accordance with FDA regulations for the validation of bioanalytical methods. This analytical method was successfully applied to monitor plasma concentrations of xanthorrhizol over time following intravenous administration in rats.