UHPLC-ESI-MS/MS determination and pharmacokinetic study of two alkaloid components in rat plasma after oral administration of the extract of Corydalis bungeana Turcz

Corynoline and acetycorynoline are active compounds of Corydalis bungeana Turcz. with various pharmacological effects such as sedation, anti-leptospira and liver injury protection effects. A specific, simple and sensitive UHPLC-ESI-MS/MS method was developed and validated for the pharmacokinetic study of corynoline and acetycorynoline in rat plasma. Corynoline and acetycorynoline were extracted from plasma samples by liquid-liquid extraction. The analysis was carried out on an Agilent SB-C18 column (1.8 μm, 50 mm × 2.1 mm) with the mobile phase of acetonitrile-0.1% formic acid (80:20, v/v). The detection was performed on a triple quadrupole tandem mass spectrometer by multiple reaction monitoring (MRM) mode via electrospray ionization (ESI) source in positive mode. The current UHPLC-ESI-MS/MS assay was validated for linearity, intra-day and inter-day precisions, accuracy, extraction recovery and stability. The lower limits of quantification were 0.10 ng/mL for corynoline and 0.353 ng/mL for acetycorynoline. Intra-day and inter-day precision were less than 12.3% and accuracy ranged from 0.18% to 14.9%. The mean extraction recoveries of analytes and internal standard (IS) from rat plasma were all more than 76.2%. This validated method was successfully applied to pharmacokinetic study in rats after oral administration of corynoline, acetycorynoline and the extract of Corydalis bungeana Turcz.