Peucedanum purpureum
1、 Pharmacopoeia standard of Peucedanum praeruptorum       This product is the dried root of Peucedanum decursivum. (miq.) maxim., an Umbelliferae plant. When the aboveground parts wither in autumn and winter, they are dug, fibrous roots are removed, and dried in the sun.
      [properties] this product is mostly in irregular cylindrical, conical or spindle shape. The main root is thin, and there are a few branch roots, 3-15cm long and 0.8-1.7cm in diameter. The surface is brown to black brown. There are occasional residual stem base and membranous leaf sheath residues on the root head, with light straight fine longitudinal wrinkles, gray white transverse lenticel like protrusions and dot like fibrous root marks can be seen. It is hard, white in cross section, narrow in skin, and scattered with a few yellow oil spots. It is fragrant, slightly bitter and pungent.
      [identification] (1) cross section of the root of this product: the cork layer consists of several to more than 10 rows of flat cells, with a cortex outside. The inner layer of the plug is very narrow, with scattered oil pipes. Phloem is broad; Most of the oil tubes are round, slightly arranged in multiple rings, with 5-10 secretory cells; . Cambium ring. The xylem is smaller, and the vessels are radially arranged; The wood ray is wide; Wood fibers are rare. Parenchyma cells contain starch granules.
      (2) Take 0.5g of this product powder, add 25ml of methanol, sonicate for 20 minutes, filter, and take the filtrate as the test solution. . According to the thin-layer chromatography (general rule 0502), suck 5 μ l of each of the above two solutions, dot them on the same silica gel G thin-layer plate, use ethyl acetate methanol water (8:1:1) as the developing agent, develop, take out, dry, and view under the UV 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   .
      Total ash   Not more than 8.0% (general rule 2302).
      Acid insoluble ash   Not more than 4.0% (general rule 2302).
      [extract] determined by the hot leaching method under the determination of alcohol soluble extract (general rule 2201), using dilute ethanol as solvent, it shall not be less than 30.0%.
      [content determination] determine according to HPLC (general rule 0512).
      ; Octadecylsilane bonded silica gel was used as filler; Methanol water (40:60) was used as mobile phase; The detection wavelength was 334nm. The number of theoretical plates should not be less than 1500 according to the peak of peucedanoside.
      Preparation of reference solution   Take an appropriate amount of peucedanoside reference substance, accurately weigh it, add methanol to make a solution containing 50 μ g per 1ml.
      Preparation of test solution   Take about 0.5g of this product powder (passing through No. 3 screen), weigh it accurately, place it in a corked conical flask, add 25ml of methanol precisely, weigh it, soak it for 1 hour, sonicate it (power 100W, frequency 40KHz) for 20 minutes, cool it, weigh it again, make up the lost weight with methanol, shake it well, filter it, accurately measure 1ml of continuous filtrate, place it in a 10ml measuring flask, add methanol to the scale, shake it well, and then get it.
      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.
      According to the calculation of dry product, the content of imperatorin (c20h24o9) in this product shall not be less than 0.90%.
      Decoction pieces
      [processing] remove impurities, wash, moisten, slice, and dry.
      . Return to lung meridian.
      [functions and indications] reduce Qi and dissipate phlegm, disperse wind and clear away heat. It is used for asthma due to phlegm heat, yellow and thick expectoration, and cough due to wind heat.
      [usage and dosage] 3-9g, or into pills or powder.
      [storage] store in a cool and dry place to prevent mold and moth.


2、 Chemical constituents of Peucedanum praeruptorum
The root contains coumarin compounds:Praeruptorin（decur-sidin)， Praeruptorin C-I (pd-c-i), namely 3 ′ (s) - (3methyl-2-butenoyloxy) -4 ′ (R) - hydroxy-3 ′, 4 ′ - dihydrozantholide [3 ′ (s) -senecioyloxy-4 ′ (R) -hydroxy-3 ′, 4 ′ -dihydroxanthhyletin], praeruptorin C Ⅱ (pd-c-ii), namely 3 ′ (s) - hydroxy-4 ′ (R -) - (3-methyl-2-butenoyloxy) - 3 ′, 4 ′ - dihydrozantholide [3 ′ (s) -hydroxy 3 ′....the main reason for the formation of praeruptorin C Ⅱ is to be discussed..the mechanism of praeruptorin C Ⅱ is to be further studied, Praeruptorin C-IV (pd-c-iv) is 3 ′ (s) - acetoxy-4 ′ (R) - (3-methyl-2-enoyloxy) - 3 ′, 4 ′ - dihydrozantholide [3 ′ (s) -acetoxy-4 ′ (R) -senecioyloxy-3 ′, 4 ′ -dihydroxanthyletin], praeruptorin C-V (pd-c-v) is 3 ′ (s) - acetoxy-4 ′ (R) - isovaleryloxy-3 ′, 4 ′ - dihydrozantholide (3 ′ (s) -etoxy-4 ′ (R) - isovaleryloxy-3 ′ - 4 ′ - Di hydroxyletin] and 3 ′ (s) - acetoxy-4 ′ (R) - angelioyloxy-3 ′, An equal mixture of 4 ′ - dihydrozantholide [3 ′ - (s) - acetoxy-4 ′ (R) - angeloyloxy-3 ′, 4 ′ - dihydrox antihyletin], purslane Ⅰ (ad- Ⅰ), namely 3 (s) - angelioyloxy-4 ′ (R) - isovaleryloxy-3 ′, 4 ′ - dihydrozantholide [3 ′ (s) - angeloy-loxy-4 ′ - (s) - isovaleryloxy-3 ′, 4 ′ - dihydroxanthyletin], nodakenetin, and citron lactone; Coumarin glycosides:Praeruptorin, peucedanoside Ⅰ, Ⅱ, Ⅲ, Ⅳ and Ⅴ; Saponins: PD saponin Ⅰ, Ⅱ, Ⅲ, Ⅳ, and Ⅴ.

3、 Pharmacological effects of Peucedanum praeruptorum
Calcium binding antagonist effect

The ethanol extract of Peucedanum praeruptorum had a stronger effect on the contraction of isolated guinea pig ileum caused by acetylcholine and histamine than water extract or butanol extract, which was noncompetitive. Peucedanum praeruptorum a can noncompetitively relieve the ileal contraction caused by acetylcholine, but also inhibit the contractile effect of K depolarization in guinea pig colonic band caused by the influx of extracellular Ca2 +, and inhibit the entry of 45 Ca2 + into smooth muscle. Peucedanum praeruptorum a, pd-c- Ⅱ and pd-c- Ⅲ can inhibit the release of allergic mediators from rat mast cells caused by ConA and phosphatidylserine, and their ic50  79100102 μ m, respectively.

Effect on platelet aggregation

Nodakenin and nodakenetin had a strong inhibitory effect on primary and secondary platelet aggregation caused by oil 2 μ mol/ladp. PD CV and PD IA (i.e. peucedane a) can promote primary hemagglutination.

Expectorant effect

With the method of collecting respiratory secretion from anesthetized cats, oral administration of Qianhu Decoction 1g/kg can increase respiratory secretion, indicating that it has expectorant effect, and the action time is long.

Coronary dilation

Praeruptorin can increase the coronary flow, but does not affect the heart rate and cardiac contractility. Peucedanum praeruptorum (E) has anti hypoxia effect on mice.