Liquid Chromatography–Mass Spectrometric Analysis of Compound K, a Ginseng Saponin Metabolite, in Rat Plasma

Abstract

A rapid, sensitive, and selective liquid chromatography–mass spectrometric (LC/MS) method for the determination of compound K, a ginseng saponin metabolite, in rat plasma was developed. Compound K and internal standard, lithospermic acid B, dimethylester were extracted from rat plasma by liquid–liquid extraction and analyzed on Atlantis column with the mobile phase of acetonitrile–ammonium formate (10 mM, pH 3.0) (75:25, v/v). The analytes were detected using an electrospray negative ionization mass spectrometry in the selected ion monitoring (SIR) mode. The standard curve was linear (r ² = 0.998) over the concentration range of 2.0–500 ng/mL. The relative standard deviation (RSD) of intra‐ and inter‐assay ranged from 1.2–3.0% to 1.3–2.9%, respectively. The recoveries of compound K ranged from 97.7% to 98.9%, with that of lithospermic acid B, dimethylester (internal standard) being 96.6% ± 7.4%. The lower limit of quantification for compound K was 2.0 ng/mL using 100 µL of plasma sample. This method was successfully applied to the pharmacokinetic study of compound K in rats.

^#Authors contributed equally to this work.

Keywords:

• Compound K
• Plasma
• LC/MS
• Ginseng saponin metabolite

Acknowledgment

This research was supported by a grant (PF 0320401‐00) from Plant Diversity Research Center of 21st Century Frontier Research Program funded by Ministry of Science and Technology of Korea government and Spela Ltd.

Notes

^#Authors contributed equally to this work.