Correlations between leaf and soil mineral concentrations and ginsenoside contents in American ginseng

Four-year-old American ginseng (Panax quinquefolium L.) plants and soil samples were collected from nine ginseng gardens. Soil and leaf mineral contents were determined and six major ginsenosides, Rb-1, Rb-2, Rc, Rd, Re, and Rg(1), were extracted from leaves and roots and quantified by high-performance liquid chromatography (HPLC). Correlation coefficients were more significant for soil nutrient levels vs. ginsenoside contents of leaves than of roots, suggesting that soil nutrient levels may play a major role in the synthesis of leaf ginsenosides. Minor elements in the leaf were also better correlated with ginsenoside contents of the root than that of the leaf. Iron content in the leaves exhibited highly significant correlations with the levels of Rb-1, Rb-2, Rc, and Rd, but calcium and copper contents were negatively correlated with Rg(1) in the roots.