UHPLC–HRMS based saponins profiling of three morphological regions in American ginseng (Panax quinquefolium L.) and their correlation with the antioxidant activity

American ginseng (Panax quinquefolium L.) is used as tonic plant and high-grade nourishment. Ultra-high-performance liquid chromatography–high resolution mass spectrometry (UHPLC–HRMS) method was established for identifying the chemical constituent in three morphological regions of American ginseng, including main root (MR), rhizome (RH) and lateral root (LR). The 63 saponins was identified in different morphological regions of 10 American ginseng samples. The chemical maker compounds in corresponding morphological region, while the major compounds of MR (malonyl-ginsenoside Rb1, ginsenoside Rd, Rs2 and pseudo-RC1), LR (stipuleanoside R2, ginsenoside Re and malonyl-ginsenoside Rc), and RH (malonyl-ginsenoside Rd, Rb3, and chikusetsu saponin II) were discovered. Correlation analysis showed that 11 compounds were positively correlated with the antioxidant activity of American ginseng.