Plasma pharmacokinetics, tissue distribution and excretion study of 6-gingerol in rat by liquid chromatography–electrospray ionization time-of-flight mass spectrometry

A rapid resolution liquid chromatography coupled with electrospray ionization (ESI) time-of-flight mass spectrometry method was developed and validated for quantitative analysis of 6-gingerol in plasma and various tissues. Liquid–liquid extraction was employed as sample preparation technique. Biological samples were separated on an Agilent Zorbax StableBond-C18 column (4.6 mm × 50 mm, 1.8 μm) and detected by TOF/MS with electrospray ionization (ESI) interface in positive ion mode. Calibration curves (1/x2 weighted) offered satisfactory linearity (r2 > 0.995) within the test range. The lower limit of quantification in different matrices was in a range of 10–100 ng/mL. Inter- and intra-day precision were in the range of 0.91–11.90% and 0.75–10.23%, respectively. Recoveries in plasma, urine and tissues ranged from 72.5% to 90.4%. Glucuronide of 6-gingerol, the major metabolite of 6-gingerol, was further determined after β-glucuronidase hydrolyzation. This developed method was successfully applied to pharmacokinetics, tissue distribution and excretion studies of 6-gingerol after oral or intraperitoneal administration in rats.