Development and validation of high liquid performance chromatography-tandem mass spectrometry method for simultaneous determination of geniposidic acid and aucubin in rat plasma for pharmacokinetic study after oral administration of Du-zhong tea extract

• Geniposidic acid (GA) and aucubin (AB) of Du-zhong tea have a variety of bioactivities.
• A LC-MS method was developed to simultaneously determine GA and AB in rat plasma.
• The PK property of GA and AB after oral Du-zhong tea was studied for the fist time.

A specific and sensitive high performance liquid chromatography coupled with tandem mass spectrometric (HPLC-MS/MS) method was developed and validated for the simultaneous determination of geniposidic acid and aucubin in rat plasma after oral administration of Du-zhong tea extract. The plasma samples were pretreated by protein precipitation with methanol and the chromatographic separation was performed on a Hypersil C18 column (4.6 mm × 250 mm, 5 μm), using a gradient mobile phase system of water-methanol (0.05% formic acid). The detection was accomplished by multiple-reaction monitoring (MRM) scanning via electrospray ionization source operating in the negative ionization mode. The linear range was 1–1000 ng/mL for geniposidic acid and 0.2–200 ng/mL for aucubin, respectively. The accuracy (relative error, R.E.%) were between −5.40 and 5.00%, while the intra-day and inter-day precisions were less than 7.95 and 7.87% for the two analytes, respectively. The method was fully validated for the sensitivity, selectivity, recovery, matrix effect and stability. Then this method was successfully applied to the pharmacokinetic study of geniposidic acid and aucubin after oral administration of Du-zhong tea extract to rats and the results indicated that this HPLC-MS/MS assay is a valuable method for the pharmacokinetic study of geniposidic acid and aucubin in rat plasma.