ИСТИНА

This report is dedicated to the discussion of the details of formation and regulation of triterpene glycosides (TG) biosynthesis in Panax spp. cell in vitro based on literature survey and the author’s own research. The legendary ginseng is a representative of the relic genus Panax from Araliaceae family of higher plants. Due to its unique therapeutic properties ginseng became one of the most studied medicinal plants in the world. Investigation of ginseng from the phytochemical standpoint lasted for more than 150 years. Different classes of secondary metabolites were isolated from Panax spp., albeit the most typical of ginseng are the TGs of dammarane series — ginsenosides. Formation of ginsenosides in Panax spp. cell cultures systematically studied for over 40 years and has now accumulated a significant amount of data that allow making some generalizations about the patterns of biosynthesis of these compounds in cells in vitro: 1. High ginsenoside content is not necessarily found in every ginseng cell strain. A decline in ginsenoside content occurred sometimes during prolonged cultivation or as a result of change in cultivation medium. However, it is possible to obtain strains with robustly high TG content. Optimization of hormonal concentration in culture medium, treatment with stress hormones (e.g. jasmonates) and elicitors often resulted in a considerable improvement of TG production. 2. In many cases alteration in ginsenoside groups in comparison to the intact plants was recorded: in cell culture the protopanaxatriol-type ginsenosides were often prevailing over the protopanaxadiol-type ginsenosides. The diversity of the glycosides declined in certain strains. 3. In some cell cultures of Panax spp. protopanaxadiol-type glycosides were mainly represented by their malonylated derivatives. This could be explained by i) necessity of their compartmentalization (vacuole targeting), ii) lower stability (due to glycosylation at the C-3-position of dammarane), and iii) higher toxicity in comparison with protopanaxatriol-type glycosides.