Rhodiola crenulata Root and Rhizome Powder

Rhodiola crenulata Root and Rhizome Powder

Final Authorized Version 1.0

Rhodiola crenulata Root and Rhizome Powder




The article consists of the dried roots and rhizomes of Rhodiola crenulata (Hook.f. & Thomson) H. Ohba, currently accepted name Sedum crenulatum Hook.f. & Thomson (Family Crassulaceae), collected after the scape wither in autumn, reduced to a fine or very fine powder. It contains NLT 1.0% of total phenylethanoids, calculated as the sum of salidroside (C14H20O7) and tyrosol (C8H10O2) on the dried basis; and NLT 0.6% of salidroside on the dried basis.



Rhodiola calliantha (H. Ohba) H. Ohba

Rhodiola cretinii (Hamet) H. Ohba

Rhodiola dumulosa (Franch.) S. H. Fu

Rhodiola heterodonta (HK. f. et Thoms.) A. Bor.

Rhodiola kirilowii (Regel) Maxim.

Rhodiola linearifolia A. Bor.

Rhodiola quadrifida (Pall.) Fisch. et Mey.

Rhodiola robusta (Praeg.) S. H. Fu

Rhodiola rosea L.

Rhodiola sachalinensis A. Bor.

Rhodiola serrata H. Ohba



Phenylethanoids: Salidroside and tyrosol

Benzoic acid: Gallic acid



• A. Botanical Characteristics

Macroscopic: Pinkish-brown or light reddish brown powder

Microscopic: Cork cell fragments sub-rectangular or polygonal, containing yellowish-brown pigments, 10–150 μm in diameter. Spiral vessels are 6–58 μm in diameter. Fibers mostly in bundles, long fusiform with oblique or blunt-round ends and striations, 10–60 μm in diameter. Parenchymatous cells are square or irregular, 2–20 μm in diameter, containing the calcium oxalate prism crystals. Abundant simple starch grains rounded with indistinct hilum and stration, 2–10 μm in diameter.

• B. HPTLC for Articles of Botanical Origin <203>

Standard solution: 2.0 mg/mL of USP Salidroside RS and 1.0 mg/mL of USP Rosavin RS in methanol

Sample solution: Sonicate 0.5 g of Rhodiola crenulata Root and Rhizome Powder in 5 mL of methanol for 10 min, centrifuge, and use the supernatant.

Chromatographic system

Adsorbent: Chromatographic silica gel with an average particle size of about 5 µm

Application volume: 5 µL, as 8-mm bands

Relative humidity: Condition the plate to a relative humidity of about 33% using a suitable device.

Developing solvent system: Ethyl acetate, methanol, water, and formic acid (77:13:10:2)

Developing distance: 6 cm

Derivatization reagent: Dissolve 1 g of diphenylamine in 40 mL of acetone, add 1 mL of aniline, and mix. Carefully add 7.5 mL of phosphoric acid, and mix.


Samples: Standard solution and Sample solution

Apply the Samples as bands and dry in air. Develop in a saturated chamber, remove the plate from the chamber, and dry in air. Treat with Derivatization reagent, heat at 120º for 5 min, and examine under visible light.

System suitability: The Standard solution shows two gray bands in the lower half of the chromatogram. The band with a higher RF is due to salidroside, and the band with a lower RF is due to rosavin.

Acceptance criteria: The Sample solution exhibits a gray band corresponding in RF and color to salidroside in the Standard solution. In the Sample solution, no band corresponding in RF and color to rosavin in the Standard solution is observed (a distinction from Rhodiola rosea Root and Rhizome). The Sample solution exhibits additional bands, including two gray bands between salidroside and rosavin bands, two yellow bands in the upper half, and a couple of gray bands close to the starting position.


Analysis: Proceed as directed in the Assay for Content of Phenylethanoids.

Acceptance criteria: The Sample solution exhibits a peak with a retention time corresponding to salidroside in the Standard solution, a peak due to tyrosol with lower intensity than salidroside, and a peak due to gallic acid. The content ratio of salidroside to tyrosol is not lower than 2.



• Content of Phenylethanoids

Solution A: 0.02% Phosphoric acid in water

Solution B: Methanol and acetonitrile (9:1)

Mobile phase: See Table 1.


Table 1


Solution A

Solution B


























Solvent: Methanol and water (6:4)

Standard solution: 0.30 mg/mL of USP Salidroside RS in methanol

Sample solution: Accurately transfer about 500 mg of Rhodiola crenulata Root and Rhizome Powder to a suitable stoppered conical flask and accurately add 15.0 mL of Solvent. Weigh the filled flask with a precision of ±0.1 mg, stopper, and sonicate for 30 min. Cool to room temperature and adjust to the initial weight by adding Solvent if needed. Before injection, pass through a membrane filter of 0.45-μm or finer pore size, and discard the first portion of the filtrate.

Chromatographic system

(See Chromatography <621>, System Suitability.)

Mode: LC

Detector: UV 275 nm

Column: 4.6-mm × 25-cm; 5-μm packing L1 (similar to Merck Purospher STAR RP-18 endcapped)

Column temperature: 25°

Flow rate: 1.0 mL/min

Injection volume: 10 µL

System suitability

Samples: Standard solution and Sample solution

Suitability requirements

Resolution: NLT 1.5 between the salidroside and tyrosol peaks, Sample solution

Tailing factor: NMT 1.5 for the salidroside peak, Standard solution

Relative standard deviation: NMT 2.0% for the salidroside peak, Standard solution


Samples: Standard solution and Sample solution

Using the chromatogram of the Standard solution and the relative retention times, identify the retention times of the peaks corresponding to gallic acid, salidroside, and tyrosol in the Sample solution. [Note—The approximate relative retention times for the peaks of gallic acid, salidroside, and tyrosol are 0.48, 1.00, and 1.05, respectively.]

Separately calculate the percentages of salidroside and tyrosol in the portion of Rhodiola crenulata Root and Rhizome Powder taken:


Result = (rU/rS) × CS × (V/W) × F × 100


rU   = peak area of the relevant analyte from the Sample solution

rS   = peak area of salidroside from the Standard solution

C = concentration of USP Salidroside RS in the Standard solution (mg/mL)

V    = volume of the Sample solution (mL)

W   = weight of Rhodiola crenulata Root and Rhizome Powder taken to prepare the Sample solution (mg)

F    = conversion factors for the analytes; 1.00 for salidroside, 0.43 for tyrosol


Calculate the content of total phenylethanoids as the sum of the percentages of salidroside and tyrosol.

Acceptance criteria

Salidroside: NLT 0.6% on the dried basis

Total phenylethanoids: NLT 1.0% on the dried basis



Articles of Botanical Origin <561>, Limits of Elemental Impurities: Meets the requirements

Articles of Botanical Origin <561>, Pesticide Residue Analysis: Meets the requirements

Microbial Enumeration Tests <61>: The total aerobic bacterial count does not exceed 105 cfu/g, the total combined molds and yeasts count does not exceed 103 cfu/g, and the bile-tolerant Gram-negative bacteria count does not exceed 103 cfu/g.

Tests for Specified Microorganisms <62>: Meets the requirements of the tests for the absence of Salmonella species and Escherichia coli

Articles of Botanical Origin <561>, Test for Aflatoxins: Meets the requirements



Articles of Botanical Origin <561>, Methods of Analysis, Alcohol-Soluble Extractives, Method 1: NLT 25.0%

Loss on Drying <731>: NMT 12.0%

Articles of Botanical Origin <561>, Methods of Analysis,Total Ash: NMT 6.0%

Articles of Botanical Origin <561>, Methods of Analysis, Acid-Insoluble Ash: NMT 1.0%



• Packaging and Storage: Preserve in well-closed containers, protected from light and moisture, and store at controlled room temperature.

• Labeling: The label states the Latin binomial following the official name of the plant contained in the article.

USP Reference Standards <11>

USP Rosavin RS

USP Salidroside RS



Other Versions

Proposed For Comment Version 0.2
Proposed For Development Version 0.1