Determination and validation of psammaplin A and its derivatives in rat plasma by liquid chromatography-tandem mass spectrometry and its application in pharmacokinetic study

A liquid chromatography-tandem mass (LC-MS/MS) method was developed for the determination of psammaplin A (PsA) and its newly synthesized derivatives (PsA 107, PsA 109, and PsA 123) in rat plasma using bupropion as an internal standard (IS). The plasma samples were deproteinized with acetonitrile. Chromatographic separation was performed on hydro-RP column (75 × 2.0 mm, 80 Å, 4 μm) with isocratic elution using 5 mM ammonium formate buffer/acetonitrile (30:70, v/v) at a flow rate of 0.4 mL/min and the total run time was 5 min. Mass spectrometric detection was performed with positive electrospray ionization (ESI) in multiple reaction monitoring (MRM) mode. The ion transitions monitored were m/z 663.2 → 331.0, 687.2 → 343.1, 587.3 → 293.1, 563.3 → 281.0, and 240.0 → 184.0 for PsA, PsA 107, PsA 109, PsA 123, and IS, respectively. All analytes showed good linearity over the concentration range of 5.00-5000 ng/mL (r2 ≥ 0.994). The lower limit of quantification was 5 ng/mL for PsA and its three PsA derivatives. Within- and between-run precisions (relative standard deviation, RSD) were less than 9.66% and accuracy (relative error, RE) ranged from −9.34% to 7.25%. Established method was successfully applied to the investigation of pharmacokinetic properties of PsA and its derivatives in rats after intravenous administration at a dose of 2 mg/kg.