Dracaena leaf
1、       This product is the dried leaves of Sauropus spatulifolius beille, a Euphorbiaceae plant. Harvested in summer and autumn and dried in the sun.
      [properties] the product is in a mass or long strip shape, and after flattening, it is in a long ovate, ovate lancet or inverted ovate lancet shape. The surface is yellowish brown, yellowish green or greenish brown, with a length of 5-9cm and a width of 2.5-3.5cm. The apex is blunt and slightly concave with small sharp spines, and the base is wedge-shaped or slightly round, full or slightly wrinkled into waves. The ventral dorsum of the midvein on the lower surface is prominent, the base is occasionally pilose, the lateral veins are pinnate, 5-6 pairs, and the side veins are synthesized near the outer edge; Petiole short. It is light and sweet.
      [identification] (1) the leaf surface of this product: the vertical walls of the upper and lower epidermal cells are wavy and curved; Stomatal horizontal axis type, some accessory guard cells vary greatly in size. There are papillary processes near the main vein.
      The powder of this product is yellowish brown. The fiber is slender and the wall is slightly thick. Calcium oxalate cluster crystals are scattered or arranged in rows in palisade tissue cells or sponge tissue cells, with a diameter of 15-30 μ M. . Stomatal horizontal axis type, some accessory guard cells vary greatly in size. The diameter of threaded conduit, reticulated conduit and conduit with marginal pits is 40 ～ 140 μ M.
      (2) Take 1g of this product powder, add 30ml of water saturated n-butanol, sonicate for 30 minutes, filter, evaporate the filtrate, and add 1ml of ethanol to dissolve the residue as the test solution. In addition, 1g of the control medicinal material of Dracaena leaf was prepared into the control medicinal material solution by the same method. According to the test of thin-layer chromatography (general rule 0502), suck 2 μ l of each of the above two solutions, dot them on the same silica gel G thin-layer plate, use cyclohexane ethyl acetate (8:1.5) as the developing agent, develop, take out, air dry, spray 2% vanillin sulfuric acid solution, and heat at 105 ℃ until the spots are clear. In the chromatogram of the test sample, spots of the same color appear on the corresponding position of the chromatogram of the control medicinal material.
      ; Not more than 2% (general rule 2301).
      Moisture   Not more than 15.0% (the second method of general rule 0832).
      Total ash   Not more than 11.0% (general rule 2302).
      .
      [content determination] determine according to HPLC (general rule 0512).
      Chromatographic conditions and system suitability test   Octadecylsilane bonded silica gel was used as filler; The mobile phase was methanol-0.4% phosphoric acid solution (48:52); The detection wavelength was 349nm. The number of theoretical plates should not be less than 3000 according to the peak of kaempferol-3-o-gentiobioside.
      Preparation of reference solution   Take an appropriate amount of kaempferol-3-o-gentiobioside reference substance, accurately weigh it, add 50% methanol to make a solution containing 55 μ g per 1ml.
      Preparation of test solution   Take about 1g of this product powder (through No. 2 screen), weigh it accurately, place it in a corked conical flask, add 25ml of 50% methanol precisely, close the stopper, weigh it, sonicate (power 250W, frequency 33khz) for 40 minutes, cool it, weigh it again, make up the lost weight with 50% 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 kaempferol-3-o-gentiobioside (c27h30o16) shall not be less than 0.035%.
      [nature, taste and meridian tropism] sweet, light and flat. Return to lung and stomach channels.
      [functions and indications] moisten the lungs, relieve cough, and relieve constipation. For lung dry cough, pharyngeal pain, aphonia, constipation.
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2、
It contains steroids, amino acids, peptides and proteins.

3、 Pharmacological effects of Dracaena leaf
The extract of Dracaena leaf has obvious antagonistic effect on acute and chronic inflammation, and has peripheral analgesic effect, but has no central analgesic effect; It has strong antibacterial effect on Staphylococcus aureus, Staphylococcus aureus resistant strains, Escherichia coli, Pseudomonas aeruginosa, Hemolytic Streptococcus A and hemolytic streptococcus B.