This is the fourth part or our update and reformat of Rhodiola Rosea: A Phytomedicinal Overview. While this is a concise summary of Rhodiola rosea phytochemistry, you may wish to dig further with Dr. Zakir Ramazanov’s Rhodiola Rosea Pharmacology, Phytochemistry and Standardization, which goes into much greater detail on how exactly this potent adaptogen provides rhodiola rosea benefits despite such a low toxicity and so few side-effects.
I hope this concise summary of R. rosea’s phytochemistry helps you better understand and thus better utilize this natural supplement in your overall health regiment.
Rhodiola Rosea’s Phytochemistry
The investigation of the phytochemistry of R. rosea root has revealed the presence of six distinct groups of chemical compounds:
- Phenylpropanoids: rosavin, rosin, rosarin (specific and exclusive to R. rosea);
- Phenylethanol derivatives: salidroside (rhodioloside), tyrosol;
- Flavanoids: rodiolin, rodionin, rodiosin, acetylrodalgin, tricin;
- Monoterpernes: rosiridol, rosaridin;
- Triterpenes: daucosterol, beta-sitosterol;
- Phenolic acids: chlorogenic and hydroxycinnamic, gallic acids.
The standardization of R. rosea root extracts has gone through two distinct phases. Initially, in the 1970s, the compound responsible for its unique pharmacological properties was believed to be salidroside (rhodioloside).2,23,24,26,27 Therefore, the first generation of R. rosea tincture/extracts approved by the Russian Pharmacopoeia Committee was standardized to a minimum of 0.8 percent salidroside content.25
In the late 1980s, demand for R. rosea-based phytomedicines dramatically increased. The wild-crafted raw material was over-harvested, resulting in a steady decline in the quality and effectiveness of “Rhodiola” preparations. Scientific investigation revealed that other species of genus Rhodiola (which also contained salidroside) were being substituted for R. rosea. While some of these mixed batches were highly variable in quality, others had no pharmacological effect. Logically, the suspicion arose that the salidroside standard was inadequate. Based on comparative analysis, the obvious hypothesis was that the original high potency product contained other active compounds specific to R. rosea that had not yet been identified.
Specific Compounds Set Rhodiola Rosea Apart From Other Rhodiola Species
After more than a decade of research, Kurkin and colleagues presented evidence in 1986 that the chemical composition of R. rosea root is, in fact, different from the other species of genus Rhodiola.23 Using newly developed methods of analysis, Dubichev and colleagues demonstrated that R. rosea root contains three cinnamyl alcohol-vicianosides — rosavin, rosin, and rosarin — that are specific to this species.28,29 The term rosavins can be used to include rosavin, rosin, and rosarin (see chemical figures).
It became evident that salidroside is present in all chemically analyzed plants in the genus Rhodiola, and in a wide variety of species outside the genus.2,25-34 The term salidroside is derived from Salix, the genus name for the willows. Salidroside was first isolated in 1926 from Salix triandra L. (Salicaceae).33 Since then it has been detected in Vaccinium vitis-idaea L. (Ericaceae) and in Rhododendron35,36 (plants not belonging to the genus Rhodiola) in concentrations that can be higher than levels found in Rhodiola species, including R. rosea. Therefore, salidroside alone is not a useful marker compound for differentiating true R. rosea from other Rhodiola species; nor should it be used as the only marker compound for the standardization of R. rosea root extracts.
According to the revised 1989 Soviet Pharmacopeia,37 the extracts of R. rosea — primarily in the form of water/alcohol tinctures or dried root extract — are now standardized for both rosavins and salidroside. Although rosavins are now the accepted marker for genetically pure R. rosea (and its extracts), they are not necessarily the only pharmacologically active ingredients responsible for the efficacy observed in clinical studies. In fact, precise identification of the compounds responsible for the numerous health benefits of R. rosea remains to be confirmed.
Table 2: Comparison of Human and Animal Studies of Plants in the Genus Rhodiola *
| Species Name | Animal Studies | Human Studies |
|---|---|---|
| R. rosea | 32 | 17 |
| R. alterna | 0 | 0 |
| R. brevipetiolata | 0 | 0 |
| R. coccinea | 1 | 0 |
| R. crenulata | 4 | 1 |
| R. ellipticum | 0 | 0 |
| R. fastigita | 2 | 0 |
| R. gelida | 0 | 0 |
| R. henryi | 0 | 0 |
| R. heterodonta | 1 | 0 |
| R. kirilowii | 6 | 0 |
| R. pinnatifida | 1 | 0 |
| R. quadrifidia | 1 | 0 |
| R. sachalinensis | 6 | 0 |
| R. sacra | 5 | 0 |
| R. wolongensis | 1 | 0 |
| R. yunnanensis | 0 | 0 |
R. rosea extracts used in most human clinical studies were standardized to minimum 3 percent rosavins and 0.8-1 percent salidroside because the naturally occurring ratio of these compounds in R. rosea root is approximately 3:1.
Previous Section: Rhodiola Rosea Taxonomy and Geographical Distribution
Next Section: Rhodiola Rosea In Modern Medicine
Table of Contents: Rhodiola Rosea: A Phytomedicinal Overview
Credits and References
Supplemental Reading:
- Rhodiola for Herbal Stress Relief
- Rhodiola Supplements for Muscle Development and Athletic Performance
- Rhodiola Rosea Pharmacology, Phytochemistry and Standardization