1、 Pharmacopoeia standard of Platycladus orientalis leaves
 
This product is the dried branches and leaves of Platycladus orientalis (L.) Franco, a Platycladus orientalis. It is usually harvested in summer and autumn and dried in the shade.
[character] this product has many branches and flat twigs. The leaves are thin and scaly, alternating opposite, clinging to the branches, dark green or yellowish green. . It has a light fragrance, bitter and pungent taste.
[identification] (1) the powder of this product is yellow green. The epidermal cells on the leaves are rectangular with slightly thicker walls. The lower epidermal cells were square like; There are many stomata, concave type, larger guard cells, and dumbbell shaped in lateral view. Parenchyma cells contain oil droplets. .
(2) Take 3G of this product powder, put it into Soxhlet extractor, add appropriate amount of ether, heat and reflux until the extraction solution is colorless, discard the ether solution, volatilize the ether from the drug residue, add 50ml of 70% ethanol, heat and reflux for 1 hour, filter while hot, evaporate the filtrate, add 25ml of water to dissolve the residue, add 3ml of hydrochloric acid, heat and hydrolyze for 30 minutes, immediately cool, shake and extract with ethyl acetate twice, 20ml each time, combine the ethyl acetate solution, wash with water three times, 10ml each time, evaporate in a water bath, and dissolve the residue with 5ml of methanol as the test solution. In addition, take quercetin reference substance and add ethanol to make a solution containing 0.1mg per 1ml as the reference substance solution. Test according to thin-layer chromatography (general rule 0502), suck 3 µ l each of the above test solution and reference solution, dot them on the same high-efficiency silica gel G thin-layer plate, use the upper solution of toluene ethyl acetate formic acid (5:2:1) as the developing agent, develop, take out, dry, spray 1% aluminum trichloride ethanol solution, and inspect 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.
[inspection] impurities shall not exceed 6% (general rule 2301).
The moisture content shall not exceed 11.0% (the fourth method of general rule 0832).
The total ash content shall not exceed 10.0% (general rule 2302).
Acid insoluble ash content shall not exceed 3.0% (general rule 2302).
[extract] according to the hot leaching method under the determination method of alcohol soluble extract (general rule 2201), the use of ethanol as solvent shall not be less than 15.0%.
[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; The mobile phase was methanol-0.01mol/l potassium dihydrogen phosphate solution glacial acetic acid (40:60:1.5); The detection wavelength was 254nm. The number of theoretical plates should not be less than 1500 according to quercitrin peak.
Preparation of reference solution take an appropriate amount of quercitrin reference, weigh accurately, add methanol to make a solution containing 50 µ g per 1ml.
Preparation of test solution take about 0.5g of powder, weigh accurately, place in a corked conical flask, add 20ml of methanol precisely, close the stopper, weigh, sonicate for 30 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 µ l of the test solution, inject them into the liquid chromatograph, and determine.
According to the calculation of dry product, the content of quercitrin (c21h20o11) shall not be less than 0.10%.
Decoction pieces
[processing] Platycladus orientalis leaves remove hard stems and impurities.
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Remove the Platycladus orientalis leaves with charcoal and stir fry them according to the charcoal roasting method (general rule 0213) until the surface is dark brown and the interior is burnt yellow.
This product is shaped like a Platycladus orientalis leaf, with a dark brown surface. It is brittle, easy to break, and the section is burnt yellow. .
. In addition, take quercetin reference substance and add methanol to make a solution containing 0.3mg per 1ml as the reference substance solution. According to the test of thin-layer chromatography (general rule 0502), suck 10 µ l of each of the above two solutions, dot them on the same silica gel G thin-layer plate, use toluene ethyl acetate formic acid (5:2:1) as the developing agent, develop, take out, dry, spray 1% aluminum trichloride ethanol solution, and inspect 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.
civil
[extract] the same as medicinal materials.
[nature, taste and meridian tropism] bitter, astringent and cold. .
. It is used for hematemesis, bleeding, hemoptysis, blood in stool, blood from metrorrhagia and metrorrhagia, lung heat cough, blood heat alopecia, early white hair.
[usage and dosage] 6-12g. Suitable for external use.
[storage] put it in a dry place.

2、 Chemical constituents of Platycladus orientalis leaves

The leaves contain 0.26% volatile oil, and the main component in the oil is α - thujone, including thujene, fechone, pinene, caryphylene, etc. It also contains lipid components:palmitic acid（palmitic acid）， Stearic acid, lauric acid,Myristic acid（myristic acid）， Oleic acid, linoleic acid, capric acid. It also contains flavonoids: cupressuflavo ne,Apigenin（apigenin），Quercitrin（quercitrin）， Kaempferol-7-o-glucoside, quercetin-7-o-rhamnoside, myricetin-3-o - α - l-rhamnoside, myricetin,Hinoki biflavone（hinoki-flavone），Amentoflavone. It also contains 10 nonacosanol,β - sitosterol（β-sitosterol）， Condensed tannin,Deoxypodophyllotoxin（deoxypodophyllotoxin）， Isopimaric acid.

3、 Pharmacological effects of Platycladus orientalis leaves

1. antitussive effect the alcohol precipitated part of the decoction, 10g / kg of alcohol extract and 250mg / kg of flavone extract by intraperitoneal injection have antitussive effect on cough caused by SO2 in mice. Petroleum ether extract, ether precipitate and phenolic substance have antitussive effect on cough caused by ammonia fumigation in mice; All have significant antitussive effects. The experiment of electrical stimulation of the superior laryngeal nerve in cats shows that it has obvious antitussive effect, so its action site may be in the center.

2. expectorant effect the phenol red excretion method of mice proves that the alcohol extract, petroleum ether extract or alcohol precipitate of this product have obvious expectorant effect. In recent years, isopimaric acid, an effective expectorant ingredient, has been isolated. However, the alcohol precipitated part of the decoction did not significantly increase tracheal secretions in rats. . It is preliminarily believed that the expectorant mode of this product may mainly be the direct effect on bronchial mucosa.

3. antiasthmatic effect the alcohol precipitated part of this decoction can relax the isolated tracheal smooth muscle of mice and guinea pigs, and partially block the effect of acetylcholine. . In addition, this product has the effect of reducing tissue oxygen consumption on rat trachea lung tissue respiration.

4. hemostatic effect the bleeding time of mice was measured and the coagulation test was carried out by rabbit capillary method. Both proved that Platycladus orientalis leaf Decoction significantly shortened the bleeding time of mice and the coagulation time of rabbits, showing a certain hemostatic effect. However, the coagulation effect of Platycladus orientalis charcoal was slightly worse than that of raw products.

5. sedative effect this decoction can significantly reduce spontaneous activity and prolong the sleep time of pentobarbital sodium in mice, but it has no antagonistic effect on convulsions caused by caffeine. However, the long-term application of 10 mg / kg of platyclone did not affect the spontaneous activity of rats, nor did it change their conditioned behavior, but only made their activities better coordinated. Even when the large dose of platycladione was administered, it did not affect the tissue respiration of cerebral cortex.

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7. antibacterial effect the decoction of this product has inhibitory effect on Staphylococcus aureus, catarrhalis, dysentery bacillus, typhoid bacillus, Diphtheria Bacillus, Streptococcus B, anthrax bacillus, etc. in the test tube. When the water extract of this product is 1:100 or its alcohol extract is 1:180000, it has inhibitory effect on Mycobacterium tuberculosis, and has synergistic effect with isoniazid, but other reports consider it invalid. Platycladus orientalis leaf Decoction (1:40) has inhibitory effect on influenza virus Jingke 68-1. herpesvirus.

8. other effects: after alcohol precipitation, the decoction has no obvious effect on the content of vitamin C in rat adrenal gland when administered at 60g / KGL or 30g / kg once a day for 3 consecutive days, indicating that its effect is not related to pituitary adrenal cortex function. The alcohol precipitated part of the decoction showed obvious relaxation effect on isolated intestinal segments of guinea pigs.