Production of the Phenols Salidroside and Rosavins in Rhodiola rosea Regenerants Ex Vitro Adapted to Natural Conditions

Rhodiola rosea L. is a high-altitude medicinal plant with various health-beneficial effects, associated mainly with the phenolic substances salidroside and rosavins (rosavin, rosin and rosarin). The intensive collection of R. rosea rhizomes and roots to be used in folk medicine and pharmacy has led to a decrease of the species natural resources. New opportunities for species conservation and accelerated synthesis of biologically active substances have been provided by various systems for in vitro and ex vitro cultivation. In this study, the salidroside and rosavins content was determined using HPLC analysis in in vitro cultures of R. rosea and further monitored in adapted regenerants grown ex vitro. The targeted secondary metabolites were not detected in the calli and in the roots of 1-month-old regenerants obtained on different nutrient media. The roots/rhizomes of adapted regenerants grown ex vitro in a greenhouse for 1 year and in the mountain for 1, 2 and 3 years produced increasing amounts of salidroside (from 0.4 to 1.2%) and rosavins (from 4.3 to 4.5%). The salidroside to rosavins ratio (1:3.75) in 3-year-old regenerants grown in the mountain was close to the pharmacopoeial standard ratio of 1:3. These results show that R. rosea plants, obtainted by in vitro micropropagation and grown ex vitro are promising for drug production.