Sanbaicao
1、 Pharmacopoeia standard of sanbaicao       .
      [character] the stem of this product is cylindrical, with 4 longitudinal grooves, one of which is wide; The section is yellowish brown to tan, fibrous, hollow. Single leaves alternate, leaves ovate or ovate lanceolate, 4-15cm long and 2-10cm wide; apex acuminate, base cordate, entire, 5 basal veins; The petiole is long with longitudinal wrinkles. Racemose inflorescences are opposite to leaves at the top of branches, with small brown flowers. . The air is weak and the taste is light.
      [identification] (1) the leaf surface of this product: the upper and lower epidermal cells are slightly polygonal, the cuticle texture is obvious, there are oil cells scattered in the epidermis, round, 32-44pm in diameter, containing yellow oil droplets. The upper epidermis is free of pores. The lower epidermis has many stomata, adventitious, glandular hairs, 2-3 cells, 40-70 μ m long, and 12-16 μ m in diameter at the base.
      Transverse section of stem: the epidermal cells are square, and the thick horn cells of the lower cortex are more at the edge line. Aerenchyma can be seen in the cortex, which is composed of round like parenchyma cells, arranged into a network with large lacunae; There are oil cells and secretory tubes scattered. The oil cells contain yellow oil droplets, and the secretory tubes contain light brown substances. The sheath fibers of the middle column are intermittently arranged in 3-4 rows in a ring. . The coxa is broad, and ventilatory tissue can also be seen; There are oil cells scattered. Most parenchymal cells contained calcium oxalate clusters with a diameter of 12-25 μ M.
      (2) Take 2G of the product powder, add 30ml of methanol, sonicate for 20 minutes, filter, concentrate the filtrate to 2ml, add it to an activated carbon alumina column (0.2g of activated carbon, 100-200 mesh of neutral alumina, 4G, 10mm inner diameter, dry packed column), elute with 60ml of methanol, collect the eluent, evaporate to dryness, add 1ml of ethyl acetate to the residue to dissolve it, and use it as the test solution. Another 2G of sanbaicao reference medicinal material was taken, and the reference medicinal material solution was prepared by the same method. Then take the reference substance of triacetin and add ethyl acetate to make a solution containing 1mg per 1ml as the reference solution. According to the test of thin-layer chromatography (general rule 0502), suck 10 μ l of the above test solution, 10 μ l of the control medicinal material solution, and 5 μ l of the control solution, respectively, onto the same silica gel G thin-layer plate, develop with petroleum ether (60 ～ 90 ℃) - acetone (5:2), take out, dry, spray with 10% sulfuric acid ethanol 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 positions of the chromatogram of the control medicinal material and the chromatogram of the control sample.
      [inspection] impurities shall not exceed 3% (general rule 2301).
      The moisture content shall not exceed 13.0% (the second method of general rule 0832).
      The total ash content shall not exceed 12.0% (general rule 2302).
      Acid insoluble ash content shall not exceed 3.0% (general rule 2302).
      [extract] according to the hot leaching method under the alcohol soluble extract determination method (general rule 2201), using dilute ethanol as solvent, it shall not be less than 10.0%.
      [content determination] determine according to HPLC (general rule 0512).
      Chromatographic conditions and system suitability test octadecylsilane bonded silica gel was used as filler; Methanol water (63:37) was used as mobile phase; The detection wavelength is 230nm. The number of theoretical plates should not be less than 4000 according to the peak of triacetin.
      Preparation of reference solution take an appropriate amount of Triadimefon reference, weigh accurately, add methanol to make a solution containing 40 μ g per 1ml.
      Preparation of test solution take about 0.5g of powder (passing through No. 4 screen), weigh accurately, place in a corked conical flask, add 25ml of methanol precisely, close the stopper, weigh, place for 30 minutes, sonicate (power 500W, frequency 25kHz) for 40 minutes, cool, weigh again, make up the lost weight with methanol, shake well, filter, and take the filtrate.
      The determination method is to precisely suck 10 μ l of the reference solution and 10 ～ 20 μ l of the test solution, inject them into the liquid chromatograph, and determine.
      According to the calculation of dry product, the content of Triacetin (c20h20o6) shall not be less than 0.10%.
      Decoction pieces
      [processing] remove impurities, wash, segment and dry.
      This product has irregular sections. The stem is cylindrical and has 4 longitudinal grooves, one of which is broad. The cut surface is yellowish brown to tan, hollow. The leaves are mostly broken, the complete leaves are oval or oval lanceolate after flattening, the apex is acuminate, the base is heart-shaped, entire, and the base has 5 veins. Racemes, small brown flowers. . The air is weak and the taste is light.
      .
      . Return to lung and bladder meridian.
      [functions and indications] diuretic detumescence, heat clearing and detoxification. It is used for edema, urination, drenching, astringency and pain, and taking it down; .
      [usage and dosage] 15 ～ 30g.
      [storage] store in a cool and dry place.


2、 Chemical constituents of sanbaicao
Trifolium repens leaves containquercetin （quercetin），Quercitrin（quercitrin），Isoquercitrin（isoquercitrin），Hyperin(hyperin) andrutin（rutin）。 Both stems and leaves contain hydrolysable tannins. The main component of the volatile oil is methyl-n-nonylketone.

3、 Pharmacological action of sanbaicao
1.50% decoction has inhibitory effect on Staphylococcus aureus and Salmonella typhi.
2. Physalis contained in this product: v0.5mg/kg, which can make use of urine in anesthetized dogs, and the effect is more significant when the dose is increased. In rats, 34mg/kg produced significant diuretic effect regardless of Ig or SC, and the intensity was not as strong as aminophylline, but its toxicity was only 1/4 of aminophylline.
3. Hyperoside contained in the leaves of this product has obvious anti-inflammatory effect. After implantation of wool balls in rats, 20mg/kgip per day for 7 days can significantly inhibit the inflammatory process. It also has strong antitussive effect and inhibition of ocular aldose reductase, which may be beneficial to the prevention of diabetic cataract.