UHPLC-MS/MS method for simultaneous determination of Radix Polygalae glycolipids and organic acids in rat plasma and application in a pharmacokinetic study.

Radix Polygala (Yuanzhi in Chinese) is well-known in traditional Chinese medicine (TCM) and has been used for treatment of depression, brain protection, and memory improvement for thousands of years. This plant medicine is rich in saponins, glycolipids, and organic acids. The purpose of the current study was to develop a rapid, accurate, and sensitive ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) method for the simultaneous determination of the following seven active components of Radix Polygala extracts in rat plasma: sibiricose A5 (A5); sibiricose A6 (A6); 3,6'-disinapoyl sucrose (DSS); tenuifoliside A (TFSA); tenuifoliside B (TFSB); tenuifoliside C (TFSC); and 3,4,5-trimethoxycinnamic acid (TMCA). Then, the pharmacokinetics were studied following oral administration. Plasma samples were precipitated with methanol. Chromatographic separation was successfully performed on a thermo C18 column (100 × 3.0 mm, 3 µm) with a mobile phase consisting of acetonitrile and 10 mmol/L of an ammonium acetate aqueous solution. Seven analytes were detected by multiple reaction monitoring (MRM) with an electrospray ionization source in the positive mode. The transitions of m/z were 517.1/174.9, 547.0/204.9, 753.2/205.2, 681.3/443.3, 667.2/205.1, 767.4/529.2, 236.8/103.2, and 136.9/92.9 for A5, A6, DSS, TFSA, TFSB, TFSC, TMCA, and salicylic acid (IS), respectively. The method validation showed good linearity in the range of 1-2000 ng/mL and LLOQs of 1 ng/mL for the 7 components in plasma. The accuracy, precision, and stability of QC samples were all within allowable ranges. In addition, no significant matrix effect was observed using this method. For the first time, the validated method has been successfully applied to the pharmacokinetic study of the seven components of Radix Polygala extracts in rat plasma. Moreover, this method may be applied for detecting prescriptions that contain Radix Polygala or other plant medicines that include one or more components above. The results of the pharmacokinetic study of the seven ingredients will provide important guidance to clinical medicine regarding Radix Polygala and prescriptions include Radix Polygala.