Changes in ginsenosides in Australian-grown American ginseng plants (Panax quinquefolium L.)

Abstract

American ginseng (Panax quinquefolium) plants grown at 2 sites in Victoria were analysed for neutral ginsenosides in 7 plant sections at 7 growth stages over a full growing season. Individual ginsenoside concentrations and composition over the growth period were significantly different between plant sections but were similar to those reported for American ginseng grown in other countries. There was thus no detrimental effect of growing American ginseng in a eucalypt environment. The ginsenosides content of both aerial and root sections was at a maximum when fruit were established on the plant. At this maturity, the ginsenosides concentration was highest in the root hair followed by the leaf, lateral root, main root and stem in that order. The leaf contained about 30% of total plant ginsenosides and should be considered as a potential commercial product. This would require plants to be harvested before the current dormant stage when the leaf was still in a viable condition on the plant. A study of the ginsenosides in roots cultivated over a 13-year period revealed that the concentration of ginsenosides was directly correlated with root weight, more than with root age. This suggests that a faster-growing crop will not only have a higher saleable weight but also a higher concentration of ginsenosides.