Localization of ginsenosides in Panax quinquefolium root tissues

Abstract

We carried out histochemical studies to find the localization of ginsenosides in roots of <i>Panax quinquefolium</i> cultivated in Poland. We performed an anatomical study on the structure and localization of secretory canals on the cross section of 4-year-old American ginseng roots. We observed the occurrence of large secretory canals, mainly in the middle part of the secondary cortex and less in the phloem layer. In our studies, moreover, we demonstrated the production of secretory canals within the periderm layer. After the anatomical study, the 4-year-old ginseng root was divided into periderm, cortex and xylem, and the ginsenosides were extracted from each part of the root. The TLC separation of ginsenosides was performed on silica gel Si60 glass plates with chloroform-methanol-ethyl acetate-water-hexane, 20+22+60+8+4 (<i>v</i>/<i>v</i>) as mobile phase. Quantitative analysis of ginsenosides was performed by using the TLC-densitometric method. Concerning the distribution of ginsenosides in the different anatomical parts of the root of <i>Panax quinquefolium</i>, they were contained in the periderm layer at the highest level.