Development and validation of LC-MS/MS method for quantitative determination of (−)-securinine in mouse plasma

(−)-Securinine (SE) is a major alkaloid found in plant Securinega suffruticosa, which has a wide range of pharmacological activities including anticancer, anti-parasitic and central nervous system stimulating effects, etc. To aid the pharmacological study of SE, we developed an LC-MS/MS method for quantitative determination of SE in mouse plasma. In this method, plasma samples were first prepared with salting-out assisted liquid-liquid extraction using cold acetonitrile (−20 °C) and 2.00 M ammonium acetate. Separation of SE and the internal standard (IS) from sample matrix was achieved on a Gemini Nx C18 column using 40% acetonitrile and 60% 10.0 mM ammonium acetate at a flow rate of 0.200 mL min−1. Quantification of SE was accomplished with positive electrospray ionization tandem mass spectrometry using mass transitions m/z 218.1 → 84.1 for SE, and m/z 204.1 → 70.2 for the IS. This method has a lower limit of quantitation (LLOQ) of 0.600 ng mL−1 and a linear calibration range up to 600 ng mL−1 in mouse plasma. The intra- and inter-run accuracy (%RE) and precision (%CV) were ≤±6% and 6%, respectively. The IS normalized matrix factors from six lots of plasma matrices ranged 0.92-1.07, and the recoveries of plasma SE were 99-109%. The validated method has been applied to the measurement of SE in plasma samples of a mouse study.