Rhodiola
1、       This product is the dried roots and rhizomes of Rhodiola crenulata (hook. F. et thoms.) H. Ohba, a Crassulaceae plant. After withering and withering in autumn, the flower stems are dug, the rough skin is removed, washed, and dried in the sun.
      [character]   The rhizome of this product is cylindrical, thick and short, slightly curved, with a few branches, 5-20cm long and 2.9-4.5cm in diameter. The surface is brown or brown, rough and wrinkled, and there is a layer of membranous yellow epidermis with pink patterns on the peeled surface; Some old flower stems are persistent, and the base of flower stems is covered with triangular or ovate membranous scales; The internode is irregular, and the section is pink to purple red, with a ring pattern, light and loose. The main root is cylindrical, thick and short, about 20cm long, the upper diameter is about 1.5cm, and the lateral root is 10 ~ 30cm long; the section is orange red or purple red, sometimes with cracks. It is fragrant, slightly bitter and sweet.
      [identification] (1) cross section of the root of this product: 5-8 rows of cells in the cork layer, oval and quasi round cells in the inner layer of the cork. The middle column accounts for the majority, and most vascular bundles are arranged in 2-4 rings, while the outer vascular bundle is larger and belongs to the outer tough type; The vascular bundles in the inner 2-3 rounds are gradually smaller, which are of peri wood type.
      Cross section of rhizome: the old rhizome has 2-3 cork layer bands, while the young rhizome has no cork layer band. . The cortex is narrow. The vascular bundle of the middle column is a large circumferential tough vascular bundle with radial circular arrangement; The vascular tissues at the inner and outer sides of the vascular bundle are developed in an antithetic manner, with parenchyma in the middle. The phloem and xylem are nearly equal in length, separated into slender strips by secondary rays, and the cambium is obvious. The medulla is broad, composed of parenchymal cells and scattered tough medullary vascular bundles. Parenchyma cells contain Brown secretions.
      (2) Test according to the thin-layer chromatography (general rule 0502), suck 10 μ l of the control solution and the test solution under the item of [content determination], respectively dot them on the same silica gel G thin-layer plate, use the lower layer solution of chloroform methanol acetone water (6:3:1:1) as the developing agent, develop, with an exhibition distance of 18cm, take out, air dry, and fumigate in iodine vapor. In the chromatogram of the test sample, spots with the same color appear at the corresponding position of the chromatogram of the control sample.
      [check]   The moisture content shall not exceed 12.0% (the second method of general rule 0832).
      The total ash content shall not exceed 8.0% (general rule 2302).
      Acid insoluble ash content shall not exceed 2.0% (general rule 2302).
      [extract]   According to the hot leaching method under the determination of alcohol soluble extract (general rule 2201), 70% ethanol is used as solvent, which shall not be less than 22.0%.
      [content determination]   Determine according to high-performance liquid chromatography (general rule 0512).
      ; Methanol water (15:85) was used as mobile phase; The detection wavelength was 275nm. The number of theoretical plates should not be less than 2000 according to the salidroside peak.
      Preparation of reference solution   .
      Preparation of test solution   Take about 0.5g of this product powder (passing through No. 3 screen), weigh it accurately, place it in a corked conical flask, add 10ml of methanol precisely, close the stopper, weigh it, sonicate it for 30 minutes, cool it, weigh it again, make up the lost weight with methanol, shake it well, filter it, and take the filtrate.
      Assay   Precisely suck 10 μ l of the reference solution and 10 μ l of the test solution respectively, inject them into the liquid chromatograph, and determine.
      According to the calculation of dry product, the content of salidroside (c14h20o7) shall not be less than 0.50%.
        Decoction pieces
      [processing]   Remove fibrous roots and impurities, slice and dry.
      [nature, taste and meridian tropism]   Sweet, bitter, flat. Return to lung and heart meridian.
      [function and indications]   Invigorate Qi and blood circulation, unblock pulse and relieve asthma. For Qi deficiency and blood stasis, chest pain, stroke hemiplegia, fatigue and asthma.
      [usage and dosage]   3～6g。
      [storage]   Place in a ventilated and dry place, damp proof and mothproof.


2、 Chemical constituents of Rhodiola
1. the roots and stems of Rhodiola sakhalinensis containTyrosol(tyrosol) and salidroside, also known asSalidroside（rhodioloside）。

2. thirteen components were isolated from the root of Rhodiola sachalinensis, and nine of them were identified as follows:caffeic acid（caffeicacid）， ,Tyrosol（tyrosol），gallic acid（gallicacid），Ethyl gallate（gallicacidethylester）， Kaemoferol,β - sitosterol（β-sitosterol），Carotene(daucosterol) andSalidroside（rhodioloside）。

3、 Pharmacological effects of Rhodiola
It has the effects of Invigorating Qi, clearing lung, nourishing intelligence and heart, astringent and hemostatic, and dispersing blood stasis and swelling. It is mainly used to treat Qi deficiency and weakness, cold phobia, shortness of breath and fatigue after illness, lung heat cough, hemoptysis, leucorrhea diarrhea, injury due to falls, etc.