Biomass and content of ginsenosides and polyacetylenes in American ginseng roots can be increased without affecting the profile of bioactive compounds

Abstract

Fifty selected roots from a 7-year-old American ginseng (Panax quinquefolium L.) plant population grown in Denmark, with root weights varying from 191 to 490 g fresh weight (FW), were investigated for bioactive ginsenosides and polyacetylenes (PAs) in order to determine the correlation between the content of ginsenosides and PAs and root FW. PAs (falcarinol, panaxydol) and ginsenosides (Rb(1), Rb(2), Rb(3), Rc, Rd, Re, Rg(1)) were extracted from roots by sequential extraction with ethyl acetate and 80% methanol, respectively, and quantified in extracts by reverse-phase high-performance liquid chromatography (HPLC) using photodiode array detection. Total concentrations of PAs and ginsenosides varied between 150 and 780 mg/kg FW and 5,920 and 15,660 mg/kg FW, respectively. No correlation existed between the content of ginsenosides and PAs and root FW or between the total concentration of ginsenosides and PAs. Strong significant correlation was found between total content of ginsenosides and ginsenoside Rb(1) (r = 0.8190, P < 0.0001) and between total content of PAs and falcarinol (r = 0.9904, P < 0.0001). Based on the results of this study, it was concluded that it is possible to select large American ginseng roots for increased biomass production and concentration of bioactive ginsenosides and PAs without affecting the profile of bioactive compounds. Ginsenoside Rb(1) and falcarinol were found to be important selection parameters for identifying superior genotypes with the highest content of bioactive compounds.