Determination and pharmacokinetics of gastrodin and p-hydroxybenzylalcohol after oral administration of Gastrodia elata Bl. extract in rats by high-performance liquid chromatography-electrospray ionization mass spectrometric method

In this report, a high-performance liquid chromatography-electrospray ionization mass spectrometric (HPLC-MS) method was used to determine gastrodin (GAS) and p-hydroxybenzylalcohol (HBA) in rat plasma after oral administration of Gastrodia elata Bl. (Chinese name: Tianma) extract. Up to 200 mu l of plasma containing GAS, HBA and pyromucic acid (as internal standard, IS) were deproteinized with six volumes of methanol. Calibration curves showed linearity within the concentration range tested 2.00-200.00 mu g/ml for GAS and 0.832-104.00 mu g/ml for HBA in plasma with a correlation coefficient (r) greater than 0.9997. The limit of quantification of 2.00 and 0.83 mu g/ml for GAS and HBA had been achieved, respectively. The intra-day and inter-day precisions of the method were determined to be less than 17.82% for GAS and 10.21% for HBA. The recoveries were in the range of 91.12-108.64% with RSD less than 7.80% for GAS and 92.91-106.14% with RSD less than 4.30% for HBA. Evidence showed that a rapid, simple and reproducible LC-MS assay was established to determine GAS and HBA in rat plasma. (C) 2008 Elsevier GmbH. All rights reserved.