Qualitative and Quantitative Analysis of Linoleic Acid in Polygonati Rhizoma

ObjectiveTo explore the major compound in Polygonati Rhizoma (Huang Jing, 黄精) for quality control.

MethodsThe major compound was isolated and analyzed by liquid chromatography-mass spectrometry (LC-MS), and subsequently further identified by nuclear magnetic resonance (NMR). Thin layer chromatography (TLC) was optimized based on the previous methods reported in the Chinese Pharmacopeia (2015 edition).

ResultsThe major compound was isolated from the natural material and identified as linoleic acid. A high performance liquid chromatography (HPLC) method with robust linearity (R² = 0.9997), specificity, precision, stability, repeatability and recovery was developed for linoleic acid determination. TLC chromatogram was improved significantly after optimization for qualitative analysis.

ConclusionsThe optimized TLC method is practical and can be adopted for quality control of Polygonati Rhizoma (Huang Jing, 黄精). The levels of linoleic acid vary between species of Polygonati Rhizoma (Huang Jing, 黄精), with Polygonatum cyrtonema Hua (Jiang Xing Huang Jing, 姜型黄精) showing the highest contents. This study provides valuable information for quality control of Polygonati Rhizoma (Huang Jing, 黄精).