Ginsenoside variation and phytochemistry of Ontario-grown North American ginseng (Panax quinquefolius): Assessing land race diversity and biological activities

Abstract

North American ginseng (Panax quinquefolius L.) is a valuable and widely used medicinal plant and Ontario has become the largest grower of ginseng in North America. Ginseng has been grown in Ontario for over 50 years and has reached the land race stage. The phytochemistry of Ontario ginseng land races was characterized using high performance liquid chromatography (HPLC) coupled with a diode array detector (DAD), evaporative light scattering detector (ELSD), or mass spectrometry (MS) to assess ginsenoside and monosaccharide content. Nuclear magnetic resonance (NMR) was used successfully as a metabolomic tool to distinguish Ontario ginseng land races and ginseng species. Ginsenoside variation was high within and among Ontario ginseng land races and variation in ginsenoside content was correlated positively to the level of inhibition of the drug metabolizing cytochrome P450 enzyme, CYP3A4. Along with the assessment of ginsenosides, LC/MS/MS and LC/ELSD methods were developed to characterize malonyl ginsenosides and monosaccharide components respectively in Ontario ginseng. Malonyl ginsenosides accounted for a significant percentage of total ginsenoside content and glucose was found to be the major monosaccharide component. Although chromatographic ginsenoside analysis did not differentiate land races, 1H NMR was successfully applied to distinguish ginseng species and two of five land races. The results from this study contribute to the validation and characterization of Ontario ginseng and add to the value of this important medicinal crop.