Rehmannia glutinosa
1、 Pharmacopoeia standard of Rehmannia glutinosa       . Excavate in autumn, remove the reed head, fibrous root and sediment, and use them fresh; Or bake Rehmannia glutinosa slowly until it is about 80% dry. The former is known as "fresh rehmannia glutinosa", while the latter is known as "raw Rehmannia glutinosa"
      [character] fresh rehmannia glutinosa   It is spindle shaped or strip-shaped, 8-24cm long and 2-9cm in diameter. The outer skin is thin, and the surface is light red and yellow, with curved longitudinal wrinkles, bud marks, transverse lenticel like protrusions and irregular scars. It is fleshy and easy to break. The skin of the section is yellowish white, orange oil spots can be seen, the wood is yellowish white, and the ducts are arranged radially. It tastes slightly sweet and bitter.
      Rehmannia glutinosa   Most of them are irregular agglomerates or oblong, bulging in the middle, slightly thin at both ends, and some are small, strip-shaped, slightly flat and twisted, 6-12cm long and 2-6cm in diameter. The surface is brownish black or brownish gray, extremely wrinkled, with irregular transverse curved lines. Weight, soft and tough, not easy to break, brown black or dark black section, shiny, sticky. It tastes slightly sweet.
      [identification] (1) cross section of this product: cork cell sequence. Parenchymal cells in the inner layer of the thrombus were loosely arranged; There are many secretory cells scattered, containing orange yellow oil droplets; Occasional stone cells. . The cambium is broken. The xylem ray is broad; The ducts were sparse and arranged radially.
      Raw Rehmannia powder dark brown. Cork cells are light brown. . The shape of secretory cells is similar to that of ordinary parenchyma cells, containing orange yellow or orange red oil droplets. The diameter of the marginal pit conduit and reticulate conduit is about 92 µ M.
      (2) Take 2G of this product powder, add 20ml of methanol, heat and reflux for 1 hour, cool, filter, and concentrate the filtrate to 5ml as the test solution. In addition, take Catalpol reference substance and add methanol to make a solution containing 0.5mg per 1ml as the reference solution. According to the test of thin-layer chromatography (general rule 0502), suck 5 µ l each of the above two solutions, dot them on the same silica gel G thin-layer plate, use chloroform methanol water (14:6:1) as the developing agent, develop, take out, dry, spray anisaldehyde test solution, and heat at 105 ℃ until the spots are clear. In the chromatogram of the test sample, spots with the same color appear at the corresponding position of the chromatogram of the control sample.
      (3) . In addition, take the calycosin reference substance and add methanol to make a solution containing 1mg per 1ml as the reference substance solution. According to the test of thin-layer chromatography (general rule 0502), suck 5 µ l of the above test solution and 2 µ l of the control solution, respectively dot them on the same silica gel G thin-layer plate, use ethyl acetate methanol formic acid (16:0.5:2) as the developing agent, develop, take out, air dry, dip the plate with 0.1% 2,2-diphenyl-1-picrylhydrazyl absolute ethanol solution, and air dry. 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] moisture   Rehmannia glutinosa   .
      Total ash   Not more than 8.0% (general rule 2302).
      Acid insoluble ash   Not more than 3.0% (general rule 2302).
      [extract] determined according to the cold leaching method under the determination method of water-soluble extract (general rule 2201), it shall not be less than 65.0%.
      [content determination] Catalpol   Determine according to high-performance liquid chromatography (general rule 0512).
      Chromatographic conditions and system suitability test   Octadecylsilane bonded silica gel was used as filler; The mobile phase was acetonitrile-0.1% phosphoric acid solution (1:99); .
      Preparation of reference solution   Take an appropriate amount of Catalpol reference substance, weigh it accurately, add mobile phase to make a solution containing 10 µ g per 1ml.
      Preparation of test solution   Take this product (raw Rehmannia glutinosa) and cut it into small pieces of about 5mm. After drying at 80 ℃ under reduced pressure for 24 hours, grind it into coarse powder, take about 0.8g, accurately weigh it, place it in a corked conical flask, precisely add 50ml of methanol, weigh it, heat it to reflux and extract it for 1.5 hours, cool it, then weigh it, use methanol to make up the lost weight, shake it well, filter it, accurately measure 10ml of the continued filtrate, concentrate it to near dryness, dissolve the residue with mobile phase, transfer it to a 10ml volumetric flask, dilute it to the scale with mobile phase, shake it well, filter it, and take the continued filtrate.
      Assay   Precisely suck 10 µ 1 each of the reference solution and the test solution, inject them into the liquid chromatograph, and determine.
      The content of Catalpol (c15h22o10) in Rehmannia glutinosa should not be less than 0.20% based on the dry product.
      Verbascoside   Determine according to high-performance liquid chromatography (general rule 0512).
      Chromatographic conditions and system suitability test   Octadecylsilane bonded silica gel was used as filler; The mobile phase was acetonitrile-0.1% acetic acid solution (16:84); The detection wavelength was 334nm. The theoretical number of turns should not be less than 5000 according to the calycosin peak.
      Preparation of reference solution   .
      Test solution preparation   Accurately measure 20ml of the secondary filtrate under Catalpol in [content determination], recover the solvent under reduced pressure and close to dry, dissolve the residue with mobile phase, transfer it to a 5ml measuring flask, add mobile phase to the scale, shake well, filter, and take the secondary filtrate.
      Assay   .
      The content of calycosin (c29h36o15) in Rehmannia glutinosa shall not be less than 0.020% according to the dry product.
      Decoction pieces
      [processing] remove impurities, wash, moisten, cut into thick pieces, and dry.
      This product is round or irregular thick film. The outer skin is brownish black or brownish gray, extremely wrinkled, with irregular transverse curved lines. The cut surface is brownish black or jet black, shiny and sticky. It tastes slightly sweet.
      [identification] (except for the transverse section) [inspection] [extract] [content determination] is the same as that of medicinal materials.
      [nature, taste and meridian tropism] fresh rehmannia glutinosa   Sweet, bitter, cold. Homing, liver and kidney meridians.
      Rehmannia glutinosa   Gan, Han. Homing, liver and kidney meridians.
      [function and indications] fresh rehmannia glutinosa   It can clear away heat, generate fluid, cool blood and stop bleeding. It is used for Yin injury caused by fever, tongue crimson and thirsty, warm and toxic spots, hematemesis, bleeding, sore throat.
      Rehmannia glutinosa   Clearing heat and cooling blood, nourishing yin and generating fluid. It is used to warm blood in the camp, warm toxic spots, spit blood and bleed, burn Yin due to fever, irritate thirst due to crimson tongue, constipation due to fluid injury, fever due to yin deficiency, bone steaming and fever, and quench thirst due to internal heat.
      ; 12～30g。
      Rehmannia glutinosa   10～15g。
      ; Rehmannia glutinosa should be placed in a ventilated and dry place to prevent mold and moth.


2、 Chemical constituents of Rehmannia glutinosa
. Iridoid glycosides obtained from fresh rehmannia glutinosa include:Leonurus glycoside（leonuride)，Aucubin（aucubin），Catalpol（catalpol），Rehmannioside a, digitalis BDigitalis glycosideC、Digitalis glycosideD，Millitoside（melittoside)[1，2]，Geniposide(geniposide)， 8-epiloganicacid, ajugoside, 6-o-e-feruloylajugol, 6-o-z-feruloy6lajugol, 6-o-z-vanilloylajugol, 6-o-p-coumaroylajugol, 6-o- (4 ″)- o - α - l-rhamnopyranosyl rhamnopyranosyl vanilloylajugol, jioglutoside a B[3] et al; withCatalpolThe content of is the highest. It also contains sugars: D-glucose, D-galactose, D-fructose, sucrose, raffinose, stachyose, Mann ninotcmlibiose, verbascose, and the content of stachyose is the highest, reaching 64.9% [4]. Also containsL-lysine（L-lysine)，l-his （L-histidine)，L-arginine（L-argi-nine)，L-aspartic acid L-saparticacid, l-glutamicid,L-threonine（L-threonine）， ,glycine（gluycine），L-alanine（L-alanine），L-valine （L-valine)，L-isoleucine（L-isoleucine)，l-leucine （L-leucine)，l-tyrosine （L-tyrosine)，L-phenylalanine（L-phenylalnine)，γ - aminobutyric acid(γ -aminobotyricacid) and glucosamine,D-Mannitol（D-manni-tol)， Phosphoricacid [4],β - sitosterol（β-siterol)，Carotene（daucosterol）， 1-ethyl - β - d-galacetoside) [5], adenoside [6] and inorganic elements [7].

3、 Pharmacological action of Rehmannia glutinosa
1. effects on adrenal cortex function and cortisol catabolism
2. anti radiation effect
3. hepatoprotective effect: Dihuang decoction has a protective effect on experimental carbon tetrachloride toxic hepatitis in mice and can prevent the reduction of liver glycogen.
4. effect on blood glucose
5. effect on cardiovascular system
6. hemostatic effect
7. diuretic effect
8. purgative effect
9. anti inflammatory effect
10. antifungal effect
11. interferon induced and synergistically enhanced NDV induction in human tonsil cells