Determination of three triterpene alcohols in rat plasma after oral administration of pollen of Brassica campestris based on the utilization of fetal bovine serum as surrogate matrix

Abstract

24-Dehydropollinstanol (DEH), 24-methylene cholesterol (MET) and 31-norcycloartenol (NOR) are the functional triterpene alcohols of pollen of Brassica campestris. To study the pharmacokinetics of the above components of pollen of B. campestris in rats, a liquid chromatography tandem mass spectrometry (LC-MS/MS) method was developed. To avoid the interference of endogenous MET in rat plasma, fetal bovine serum (FBS) was selected as surrogate matrix and validated. Rat plasma was liquid-liquid extracted, then the chromatographic separation was conducted on a poroshell 120 SB C18 column (2.7μm, 2.1mm×50mm) at 38°C within 5.6min utilizing a gradient elution with a mobile phase consisting of (A) 0.1% formic acid in water and (B) 0.1% formic acid in methanol. The detection was performed on a triple quadrupole tandem mass spectrometer in multiple reaction monitoring (MRM) mode using positive atmospheric pressure chemical ionization (APCI). The method was validated over the concentration of 9.8-1560ng/ml; the inter-and-intra-day precisions (RSD %) were ≤7.8%, and the accuracies (RE %) were -5.3% to 12.2%, the extraction recovery ranged from 73.5% to 106.9% for all of these analytes, and no obvious matrix effect was observed. The developed method was applied successfully to study the pharmacokinetics of DEH, MET and NOR in rats after oral administration of pollen of B. campestris.

Keywords: 24-Dehydropollinstanol; 24-Methylene cholesterol; 31-Norcycloartenol; LC–MS/MS; Pharmacokinetics; Pollen of Brassica campestris.