Determination of eurycomanone in rat plasma using hydrophilic interaction liquid chromatography-tandem mass...

In this study, a rapid, sensitive, and reliable hydrophilic interaction liquid chromatography-tandem mass spectrometry (HILIC-MS/MS) method for the determination of eurycomanone in rat plasma was developed and validated. Plasma samples were pretreated with a protein precipitation method and quercitrin was used as an internal standard (IS). A HILIC silica column (2.1 × 100 mm, 3 μm) was used for hydrophilic-based chromatographic separation, using the mobile phase of 0.1% formic acid with acetonitrile in gradient elution at a flow rate of 0.25 mL/min. Precursor-product ion pairs for multiple-reaction monitoring were m/z 409.1 → 391.0 for eurycomanone and m/z 449.1 → 303.0 for IS. The linear range was 2-120 ng/mL. The intra- and inter-day accuracies were between 95.5 and 103.4% with a precision of <4.2%. The developed method was successfully applied to the pharmacokinetic analysis of eurycomanone in rat plasma after oral dosing with pure compound and E. longifolia extract. The C_max and AUC_0-t , respectively, were 40.43 ± 16.08 ng/mL and 161.09 ± 37.63 ng h/mL for 10 mg/kg eurycomanone, and 9.90 ± 3.97 ng/mL and 37.15 ± 6.80 ng h/mL for E. longifolia extract (2 mg/kg as eurycomanone). The pharmacokinetic results were comparable with each other, based on the dose as eurycomanone.