1、
This product is the dried rhizome of Dioscorea nipponica Makino, a Dioscorea nipponica plant of Dioscorea nipponica. They were dug in spring and autumn, washed, removed fibrous roots and skin, and dried in the sun.
[character] the rhizome is quasi cylindrical, slightly curved, 15-20cm long and 1.0-1.5cm in diameter. The surface is yellowish white or brownish yellow, with irregular longitudinal grooves, thorn shaped residual roots and protruding stem marks on one side. It is hard, with flat section, white or yellowish white, scattered with light brown vascular bundle dots. It tastes bitter and astringent.
[identification] (1) the powder of this product is light yellow. The starch granules are oval, triangular, conical or irregular in shape, with a diameter of 3-17 μ m and a length of 33 μ M. the umbilicus is long and sutured. Calcium oxalate crystals are scattered or present in bundles in mucus cells, about 110 μ m in length. The lignified parenchyma cells are pale yellow or yellow, long oval, rectangular or prismatic, and the pits are small and sparse. The vessel with marginal pits has a diameter of 17 ～ 56p μ m, and the pits are fine, dense and oval.
(2) Take 0.5g of this product powder, add 25ml of methanol, sonicate for 30 minutes, filter, evaporate the filtrate, add 20ml of 3mol/l hydrochloric acid solution to dissolve the residue, heat and hydrolyze in a water bath for 30 minutes, cool it, add 30ml of chloroform, heat and reflux for 15 minutes, filter, evaporate the chloroform solution, add 2ml of mixed solution of chloroform methanol (1:1) to dissolve the residue as the test solution, 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), suck 3 μ l of each of the above two solutions, dot them on the same silica gel G thin-layer plate, use chloroform methanol (20:0.2) as the developing agent, develop, take out, and dry. Spray with 10% phosphomolybdic acid ethanol solution and heat at 105 ℃ for 10 minutes. In the chromatogram of the test sample, spots with the same color appear at the corresponding position of the chromatogram of the control sample.
[inspection] the moisture content shall not exceed 12.0% (the second method of general rule 0832).
The total ash content shall not exceed 5.0% (general rule 2302).
[extract] according to the hot leaching method under the alcohol soluble extract determination method (general rule 2201), 65% ethanol shall be used as solvent, which shall not be less than 20.0%.
[content determination] determine according to high performance liquid chromatography (general rule 0512).
Chromatographic conditions and system suitability test octadecylsilane bonded silica gel was used as filler; Acetonitrile water (55:45) was used as mobile phase; The detection wavelength was 203nm. The number of theoretical plates should not be less than 3000 according to the dioscin peak.
Preparation of reference solution take an appropriate amount of dioscin reference, weigh accurately, and add methanol to make a solution containing 0.3mg per 1ml.
Preparation of the test solution take about 0.25g of the powder (passing the fourth sieve), weigh it accurately, place it in a corked conical flask, add 25ml of 65% ethanol precisely, weigh it, sonicate (Power 120W, frequency 40KHz) for 30 minutes, cool it, weigh it again, make up the lost weight with 65% ethanol, shake it well, filter it, and take the 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 content of dioscin (c45h72o16) in this product shall not be less than 1.3% according to the dry product.
Decoction pieces
[processing] remove impurities, wash, moisten, cut into thick pieces, and dry.
This product is a round or oval thick piece. . The cut surface is white or yellowish white, with light brown punctate vascular bundles. Qiwei. It tastes bitter and astringent.
[identification], [inspection], [extract], [content determination] are the same as those of medicinal materials.
[nature, taste and meridian tropism] sweet, bitter and warm. It belongs to the liver, kidney and lung meridians.
[functions and indications] dispel wind and dampness, relax tendons and collaterals, activate blood circulation and relieve pain, relieve cough and asthma. It is used for rheumatism, joint swelling, pain and numbness, falling and flapping injury, flash waist and branch breath, cough and asthma.
[usage and dosage] 9 ~ 15g; it can also be made into wine.
[note] when crushing, pay attention to protection to avoid allergic reactions.
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2、 Chemical constituents of Dioscorea nipponica

ChuanshanlonghanDioscin（dioscin），Slender dioscin（gracillin）， Asperin, 25-d-spirosta-3,5-diene and p-hydroxybenzyl tartaric acid.

3、 Pharmacological action of Dioscorea nipponica

1. antitussive effect: oral administration of total saponins, water-soluble or water-insoluble saponins, molecular sieve L (ethanol reflux concentrate plus diethyl ether will precipitate, and the aqueous solution of the precipitate will pass through the molecular sieve after concentration to obtain molecular sieve L and 2 successively) or intraperitoneal injection of decoction have obvious antitussive effect (ammonia spray cough induction method). Diosgenin is ineffective. The antitussive effective part is mainly in the part with the strongest polarity. In addition, steroidal saponins are also effective in larger doses.

2. expectorant effect: oral administration of total saponins, water-insoluble saponins, molecular sieve L or intraperitoneal injection of Decoction in mice have significant expectorant effect (phenol red method), but the effect of water-soluble saponins is not significant. .

. The decoction can prevent bronchospasm caused by histamine or acetylcholine spray. The antiasthmatic active ingredients are in the most polar part and steroidal saponins, but both need larger doses to be effective.

4. cardiovascular effects: Total Saponins 10mg/kg can significantly reduce blood cholesterol and blood pressure in rabbits, delay heart rate, enhance cardiac contraction amplitude, increase urine output, reduce β / α lipoprotein ratio, and improve coronary circulation. It is considered to be effective for patients with mild atherosclerosis. It was also reported that total saponins 3mg/kg did not significantly reduce blood cholesterol levels in experimental atherosclerotic rabbits, but alleviated aortic plaque and liver fat deposition. . Intraperitoneal injection of 1g/kg of the decoction has antitussive and expectorant effects on mice, and 0.5-1.0g/kg has anti asthmatic effects on guinea pigs caused by histamine, etc. the main effective component of expectorant effect is steroidal saponin DT, and the effective part of antitussive effect is the most polar part - Ⅵ.