Tangerine peel
1、 Pharmacopoeia standard of tangerine peel       This product is the dried and mature peel of the Rutaceae plant Citrus reticulata Blanco and its cultivated varieties. The medicinal materials are divided into "tangerine peel" and "Pericarpium Citri Reticulatae". Pick ripe fruits, peel and dry them in the sun or at low temperature.
      [character]   Tangerine peel   It is often peeled into several petals, connected at the base, and some are irregular flakes, 1-4mm thick. The outer surface is orange red or reddish brown, with fine wrinkles and concave punctate oil chambers; The inner surface is light yellowish white, rough, with yellowish white or yellowish brown fascicular vascular bundles. The quality is slightly hard and brittle. It smells fragrant and tastes pungent and bitter.
      Pericarpium Citri Reticulatae   The three valves are usually connected, with neat shape and uniform thickness of about 1mm. The dot shaped oil chamber is large, transparent and clear to light. .
      [identification]   (1) The powder of this product is yellowish white to yellowish brown. . The pericarp epidermal cells are polygonal, square or rectangular in appearance, with slightly thick vertical walls, round stomata, 18-26 μ m in diameter, and unclear accessory guard cells; From the side view, the outer cuticle is thickened by the radial wall on the outside. Calcium oxalate rhombohedral crystals exist in mesocarp parenchyma cells in sheets, which are polyhedral, rhombic or biconical, with a diameter of 3-34 μ m and a length of 5-53 μ M. some cells contain parallel bicrystals or 3-5 rhombohedral crystals composed of two polyhedra. Hesperidin crystals mostly exist in parenchyma cells, yellow or colorless, in round or amorphous masses, and some can see radial stripes. The threaded duct, the perforated duct, the reticulated duct and the tracheid are smaller.
      (2) . Take hesperidin reference substance and add methanol to make a saturated solution, which is used as the reference solution. 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 prepared with 0.5% sodium hydroxide solution, use ethyl acetate methanol water (100:17:13) as the developing agent, expand to about 3cm, take out, dry, and then use the upper layer solution of toluene ethyl acetate formic acid water (20:10:1:1) as the developing agent, expand to about 8cm, take out, dry, spray aluminum trichloride test solution, and view under the ultraviolet light (365nm). In the chromatogram of the test sample, fluorescent spots of the same color appear at the corresponding positions of the chromatogram of the control sample.
      [check]   Moisture   Not more than 13.0% (the fourth method of general rule 0832).
      Aflatoxin   Determine according to the aflatoxin determination method (general rule 2351).
      .
      The content of aflatoxin B1 should not exceed 5 μ g per 1000g, and the total amount of aflatoxin G2, aflatoxin G1, aflatoxin B2 and aflatoxin B1 should not exceed 10 μ G.
      [content determination]   Determine according to high-performance liquid chromatography (general rule 0512).
      ; Octadecylsilane bonded silica gel was used as filler; The mobile phase was methanol acetic acid water (35:4:61); The detection wavelength was 283nm. The number of theoretical plates should not be less than 2000 according to the hesperidin peak.
      Preparation of reference solution   Take an appropriate amount of hesperidin reference substance, weigh accurately, add methanol to make a solution containing 0.4mg per 1ml.
      Preparation of test solution   Take about 1g of crude powder of this product, weigh accurately, put it into Soxhlet extractor, add 80ml of petroleum ether (60 ～ 90 ℃), heat and reflux for 2 ～ 3 hours, discard the petroleum ether, volatilize the drug residue, add 80ml of methanol, heat and reflux until the extraction solution is colorless, cool it, filter it, put the filtrate into a 100ml volumetric flask, wash the container with a small amount of methanol for several times, filter the washing solution into the same volumetric flask, add methanol to the scale, and shake it evenly.
      Assay   Precisely suck 5 μ l of the reference solution and 5 μ l of the test solution respectively, inject them into the liquid chromatograph, and determine.
      The content of hesperidin (c28h34o15) shall not be less than 3.5% according to the calculation of dry product.
      Decoction pieces
      [processing]   Remove impurities, spray water, moisten thoroughly, shred and dry.
      The product is in irregular strip or filament shape. The outer surface is orange red or reddish brown, with fine wrinkles and concave punctate oil chambers. The inner surface is light yellowish white, rough, with yellowish white or yellowish brown fascicular vascular bundles. It smells fragrant and tastes pungent and bitter.
      ; The content of hesperidin (c28h34o15) in the same medicinal material shall not be less than 2.5%.
      [identification] [inspection]   Same as medicinal materials.
      [nature, taste and meridian tropism]   Bitter, pungent, warm. Return to the lung and spleen meridians.
      [function and indications]   Regulating qi and strengthening spleen, drying dampness and resolving phlegm. For abdominal distension, less food, vomiting and diarrhea, cough and phlegm.
      [usage and dosage]   3～10g。
      [storage]   Store in a cool and dry place to prevent mold and moth.  


2、 Chemical constituents of Pericarpium Citri Reticulatae
Orange peel contains 1.5% (pressing method) to 2% (distillation method) of volatile oil. The main component of the oil is d-limonene, β - myrcene, α - and β - pinene, and flavonoidsHesperidin、Neohesperidin, citrin, dihydronobiletin and 5-nordihydronobiletin; ,Nobiletin(nobiletin) about 0.15% In additionSynephrine (p-hydroxyforine) 0.28% - 2.54%

3、 Pharmacological effects of tangerine peel
1. the volatile oil contained in orange peel can promote the secretion of digestive juice. The decoction has antispasmodic effect on the intestine.
2. tangerine peel can excite frog hearts in vitro and in vivo. Methyl hesperidin, a derivative of hesperidin, has antihypertensive effect, while orange peel or its alcohol extract has pressor effect.
3. the volatile oil contained in tangerine peel has an irritating expectorant effect. The ethanol extract of Pericarpium Citri Reticulatae has antiasthmatic effect.
4. Tangerine Peel Decoction can constrict renal blood vessels and reduce urine output. Orange Peel Decoction and methyl hesperidin have inhibitory effect on uterus.