Rhubarb
1、       This product is the dried roots and rhizomes of Rheum palmatum L., Rheum tanguticum maxim.ex balf., or Rheum officinale baill., a Polygonaceae plant. Before the stem and leaf wither at the end of autumn or sprout in the next spring, dig, remove the fine roots, scrape the skin, cut the petals or segments, and thread the rope into a string to dry or directly dry.
      [properties] this product is quasi cylindrical, conical, oval or irregular block, 3-17cm long and 3-10cm in diameter. The surface of those with no outer skin is yellowish brown to reddish brown, and some can see quasi white reticular texture and scattered dots (heterotypic vascular bundles), the residual outer skin is brownish brown, with many rope holes and coarse wrinkles. The texture is solid, some centers are slightly soft, and the cross-section is reddish brown or yellowish brown, showing graininess; ; The root wood is well-developed, with radial texture, obvious cambium ring, and no asterisk. It is fragrant, bitter and slightly astringent. It sticks to the teeth and feels like sand.
      [identification] (1) cross section of this product: most of the root cork layer and the inner layer of the cork have been removed. The phloem sieve tube group was obvious; The parenchyma is well developed. The cambium forms a ring. ; The ducts are non lignified, often 1 to several converging and sparsely arranged. Parenchyma cells contained calcium oxalate cluster crystals and most starch granules.
      ; The heterotypic vascular bundles are scattered, the cambium forms a ring, the xylem is located outside the cambium, the phloem is located inside the cambium, and the rays are stellate.
      Powder yellowish brown. The diameter of calcium oxalate cluster crystals is 20 ～ 160 μ m, some to 190 μ M. . There are many starch grains, single grain spherical or polygonal, with a diameter of 3-45 μ m and umbilical star shaped; The compound granule is composed of 2-8 fractions.
      (2) Take a small amount of this product powder and conduct micro sublimation. Rhombic needle crystals or feather crystals can be seen.
      (3) Take 0.1g of this product powder, add 20ml of methanol, soak for 1 hour, filter, take 5ml of filtrate, evaporate to dryness, add 10ml of water to dissolve the residue, add 1ml of hydrochloric acid, heat and reflux for 30 minutes, cool immediately, extract with diethyl ether by shaking twice, 20ml each time, combine the diethyl ether solution, evaporate to dryness, add 1ml of trichloromethane to dissolve the residue, as the test solution. . Then take Rhein reference substance and add methanol to make a solution containing 1mg per 1ml as the reference solution. According to the test of thin-layer chromatography (general rule 0502), absorb 4 μ 1 of each of the above three solutions, dot them on the same silica gel h thin-layer plate with sodium carboxymethyl cellulose as the adhesive, use the upper solution of petroleum ether (30 ～ 60 ℃) - ethyl formate formic acid (15:5:1) as the developing agent, develop, take out, dry, and view under the ultraviolet light (365nm). In the chromatogram of the test sample, there are five orange yellow fluorescent main spots at the corresponding positions of the chromatogram of the control medicinal material; .
      [inspection] Rhaponticin take 0.1g of this product powder, add 10ml of methanol, sonicate for 20 minutes, filter, take 1ml of filtrate, add methanol to 10ml, as the test solution. In addition, take Rhaponticin reference substance and add methanol to make a solution containing 10 μ g per 1ml as the reference substance solution (newly prepared for clinical use). According to the test of thin-layer chromatography (general rule 0502), suck 5 μ l of each of the above two solutions, dot them on the same polyamide film, use toluene ethyl formate acetone methanol formic acid (30:5:5:20:0.1) as the developing agent, develop, take out, dry, and view under the ultraviolet light (365nm). In the chromatogram of the test sample, the same bright blue fluorescent spots shall not appear at the positions corresponding to the chromatogram of the control sample.
      Loss on drying take this product and dry it at 105 ℃ for 6 hours. The weight loss shall not exceed 15.0% (general rule 0831).
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      [content determination] the Total Anthraquinone was determined by HPLC (general rule 0512).
      Chromatographic conditions and system suitability test octadecylsilane bonded silica gel was used as filler; The mobile phase was methanol-0.1% phosphoric acid solution (85:15); The detection wavelength is 254nm. The number of theoretical plates should not be less than 3000 according to the emodin peak.
      Preparation of reference solution accurately weigh an appropriate amount of aloe emodin reference, Rhein reference, emodin reference, chrysophanol reference, and emodin methyl ether reference, and add methanol to make a solution containing 80 μ g each of aloe emodin, rhein, emodin, and chrysophanol, and 40 μ g of emodin methyl ether per 1ml; Accurately measure 2ml of each of the above reference solutions and mix them to obtain (each 1ml contains 16 μ g of aloe emodin, rhein, emodin, chrysophanol, and 8 μ g of emodin methyl ether).
      Preparation of test solution take about 0.15g of the powder (passing through No. 4 screen), accurately weigh it, place it in a corked conical flask, precisely add 25ml of methanol, weigh it, heat and reflux for 1 hour, cool it, weigh it again, make up the lost weight with methanol, shake it well, and filter it. Accurately measure 5ml of the secondary filtrate, put it into a flask, volatilize the solvent, add 10ml of 8% hydrochloric acid solution, sonicate for 2 minutes, add 10ml of trichloromethane, heat and reflux for 1 hour, cool it, put it into a separatory funnel, wash the container with a small amount of trichloromethane, incorporate it into a separatory funnel, separate the trichloromethane layer, extract the acid with trichloromethane three times, 10ml each time, combine the trichloromethane solution, recover the solvent to dryness under reduced pressure, add methanol to dissolve the residue, transfer it to a 10ml volumetric flask, add methanol to the scale, shake well, filter, and take the secondary filtrate.
      The determination method is to precisely suck 10 μ l of the reference solution and 10 μ l of the test solution, inject them into the liquid chromatograph, and determine.
      The total anthraquinones contained in this product shall not be less than 1.5% based on the total amount of aloe emodin (c15h10o5), Rhein (c15h8o6), emodin (c15h10o5), chrysophanol (c15h10o4) and emodin methyl ether (c16h12o5) according to the dry product.
      Free anthraquinone was determined by HPLC (general rule 0512).
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      Preparation of reference solution take the reference solution under the Total Anthraquinone item of [content determination].
      Preparation of test solution take about 0.5g of powder (passing through No. 4 screen), weigh it accurately, place it in a corked conical flask, add 25ml of methanol precisely, weigh it, heat and reflux for 1 hour, cool it, weigh it again, make up the lost weight with methanol, shake it well, filter it, and take the continuous filter solution.
      The determination method is to precisely suck 10 μ l of the reference solution and 10 μ l of the test solution, inject them into the liquid chromatograph, and determine.
      The free anthraquinones in this product shall not be less than 0.2% based on the total amount of aloe emodin (c15h10o5), Rhein (c15h8o6), emodin (c15h10o5), chrysophanol (c15h10o4) and emodin methyl ether (c16h12o5), calculated as a dry product.
      Decoction pieces
      [processing] remove impurities from rhubarb, wash, moisten, cut into thick pieces or pieces, and air dry.
      This product is irregular round thick piece or block with different sizes. . The cut surface is yellowish brown to reddish brown, relatively flat, with scattered or ring shaped stars and gaps.
      [content determination] free anthraquinone is the same as that of medicinal materials, and shall not be less than 0.35%.
      [identification], [inspection], [extract], [content determination] (Total Anthraquinone) is the same as that of medicinal materials.
      Remove the rhubarb tablets with wine and fry them dry according to the wine roasting method (general rule 0213).
      This product is shaped like a large yellow tablet, with a dark brown yellow surface and some visible focal spots. It has a slight wine aroma.
      [content determination] the content of free anthraquinone shall not be less than 0.50% of that of medicinal materials.
      [identification], [inspection], [extract], [content determination] (Total Anthraquinone) is the same as that of medicinal materials.
      Remove the cooked rhubarb, stew or steam it according to the wine stewing or wine steaming method (general rule 0213) until it is black inside and outside.
      The product is irregular pieces, with black surface, and radial texture in the middle of the section. It is hard and slightly fragrant.
      [content determination] the content of free anthraquinone shall not be less than 0.50% of that of medicinal materials.
      [identification], [inspection], [extract], [content determination] (Total Anthraquinone) is the same as that of medicinal materials.
      Remove the rhubarb tablets with rhubarb charcoal, and fry them according to the charcoal roasting method (general rule 0213) until the surface is burnt black and the interior is burnt brown.
      This product is shaped like rhubarb tablets, with a burnt black surface and a dark brown or burnt Brown interior, with a burnt aroma.
      [content determination] the Total Anthraquinone shall not be less than 0.90% of that of medicinal materials.
      Free anthraquinone shall not be less than 0.50% of that of medicinal materials.
      [identification], [inspection], [extract] are the same as that of medicinal materials.
      [nature, taste and meridian tropism] bitter, cold. Guipi, stomach, large intestine, liver and pericardium meridians.
      [functions and indications] it can clear away heat and fire, cool blood and detoxify, expel blood stasis, clear meridians, promote dampness and eliminate jaundice. It is used for constipation due to excessive heat accumulation and stagnation, blood heat vomiting, red eyes and swollen pharynx, carbuncle swelling and sores, intestinal carbuncle and abdominal pain, blood stasis and amenorrhea, postpartum stasis, traumatic injury, damp heat dysentery, jaundice and hematuria, gonorrhea, edema; External treatment of burns and scalds. Wine rhubarb is good at clearing the heat toxin in the upper energizer blood, which is used for red eyes, swollen pharynx and swollen gingiva. . Rhubarb charcoal can cool blood, remove blood stasis and stop bleeding. It is used for blood heat with blood stasis.
      . For external use, apply appropriate amount to the affected area after grinding.
      [note] use with caution during pregnancy, menstruation and lactation.
      [storage] store in a ventilated and dry place to prevent moths.


2、 Chemical constituents of rhubarb
. More than 80 compounds of different kinds, such as anthraquinone, dianthraquinone, stilbene, phenylbutanone, tannin, naphthochrone, have been isolated from rhubarb, which can be generally divided into anthraquinones, polysaccharides and tannins. Anthraquinones and their derivatives account for 3% - 5%, which can be divided into free type and bound type. The free type includesRhein、Emodin, emodinAloe Emodin、Emodin methyl ether、Chrysophanol, isoemodin, etc., and the binding type mainly includes anthraquinone glycosides and bisanthraquinone glycosides. There aresennoside a 、SennosideB、SennosideC、SennosideD、SennosideE、SennosideF. Among them, a and B, C and D, e and F are mesosomes, 10-10 'positions of a, C and E are trans, and B, D and F are CIS. Anthraquinone derivatives in rhubarb are generally in the bound state. .

3、 Pharmacological effects of rhubarb
It can relieve heat and unblock intestines, cool blood and detoxify, expel blood stasis and dredge meridians. It is used for constipation due to excess heat, abdominal pain due to stagnation, diarrhea and malaise, jaundice due to damp heat, vomiting due to blood heat, red eyes, pharyngeal swelling, abdominal pain due to intestinal carbuncle, carbuncle swelling and sores, blood stasis and amenorrhea, traumatic injury, external treatment of water and fire scald; Upper gastrointestinal bleeding. Wine rhubarb is good at clearing the upper energizer and separating the heat poison from the blood. For red eyes, swollen pharynx and swollen gingiva. Cooked rhubarb has slow purgation and detoxification. . Rhubarb charcoal cools blood, removes blood stasis and stops bleeding. It is used for blood heat with blood stasis.