Determination of YZG-331 in mouse plasma using liquid chromatography–tandem mass spectrometry

• YZG-331 is a promising candidate with new mechanism for the treatment of insomnia.
• A rapid and sensitive LC–MS/MS method for analysis of YZG-331 in mouse plasma is developed for the first time.
• The method was fully validated and successfully applied to a pharmacokinetic study of YZG-331 in mice.
• The pharmacokinetic parameters of YZG-331 in this paper are reported for the first time.

A rapid and sensitive liquid chromatography–tandem mass spectrometry (LC–MS/MS) method for the determination of YZG-331 in mouse plasma was developed. Plasma samples containing YZG-331 and YZG-441 (internal standard, IS) were prepared using a simple protein precipitation by the addition of acetonitrile. Thermo Scientific TSQ Quantum triple quadrupole system with multiple reaction monitoring (MRM) positive scanning mode was applied. The separation was performed on a ZorbaxSB-C18 column (3.5 μm, 2.1 mm × 100 mm) at a flow rate of 0.2 mL/min, using acetonitrile/water containing 0.1% formic acid (v/v) as mobile phase. The MS/MS ion transit ions monitored were 386→254 for YZG-331 and 400→268 for IS. Linear detection responses were obtained for YZG-331 ranging from 25 to 5000 ng/mL and the lower limits of quantitation (LLOQ) for the compound was 25 ng/mL. The intra- and inter-day precisions (R.S.D.%) were within 12.6% for all analytes, while the deviation of assay accuracies was within ±6.9%. The average recoveries of analytes were greater than 94.3%. The analytes were proved to be stable during all sample storage, preparation and analytic procedures. The method was successfully applied to the pharmacokinetic studies of YZG-331 in mice.