1、 Pharmacopoeia standard of bitter almond
This product is the dried and mature seeds of Prunus armeniaca l.var.ansu maxim., Prunus sibirica L., Prunus mandshurica (maxim.) Koehne or Prunus armeniaca L., a Rosaceae plant. Harvest the mature fruits in summer, remove the pulp and core shell, take out the seeds, and dry them in the sun.
[properties] this product is flat heart-shaped, 1-1.9cm long, 0.8-1.5cm wide, and 0.5-0.8cm thick. Its surface is yellowish brown to dark brown, one end is pointed, the other end is blunt, plump, asymmetric left and right, there is a short linear seed umbilical on one side of the tip, and there are many dark brown veins upward at the round end commissure. The seed coat is thin, cotyledons 2, milky white, oily. The breath is slight and the taste is bitter.
[identification] (1) seed coat surface view: seed coat stone cells are scattered or connected in a single number, yellowish brown to brown, and the surface view is polygonal, oblong or shell like, with a diameter of 25-150 µ M. the seed coat outer epidermal cells are light orange yellow to brownish yellow, often connected with seed coat stone cells, quasi round, and the wall is often shrunk.
(2) Take 2G of this product powder, put it in Soxhlet extractor, add appropriate amount of dichloromethane, heat and reflux for 2 hours, discard the dichloromethane liquid, volatilize the drug residue, add 30ml of methanol, heat and reflux for 30 minutes, cool it, filter it, and the filtrate is used as the test solution. In addition, take amygdalin reference substance and add methanol to make a solution containing 2mg per 1ml as the reference solution. . 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 peroxide value shall not exceed 0.11 (general rule 2303).
[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 acetonitrile-0.1% phosphoric acid solution (8:92); The detection wavelength was 207nm. The number of theoretical plates should not be less than 7000 based on the peak of amygdalin.
Preparation of reference solution take an appropriate amount of amygdalin reference, weigh accurately, and add methanol to make a solution containing 40 µ g per 1ml.
Preparation of test solution take about 0.25g of powder (passing through No. 2 screen), weigh accurately, place in a corked conical flask, add 25ml of methanol precisely, close the stopper, weigh, sonicate (power 250W, frequency 50KHz) for 30 minutes, cool, weigh again, make up the lost weight with methanol, shake well, filter, accurately measure 5ml of continuous filtrate, place in a 50ml measuring flask, add 50% methanol to dilute to the scale, shake well, filter, and take the continuous filtrate.
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The content of amygdalin (c20h27no11) in this product shall not be less than 3.0%.
Decoction pieces
[processing] bitter almonds are mashed.
[character], [identification], [inspection], [content determination] are the same as those of medicinal materials.
Take the bitter almond and peel it according to the method (general rule 0213). Mash when needed.
This product has a flat heart shape. The surface is milky white or yellowish white, one end is pointed, the other end is blunt and round, hypertrophic, left-right asymmetry, oil rich. It has special aroma and bitter taste.
[content determination] the content of amygdalin (c20h27no11) in the same medicinal material shall not be less than 2.4%.
[identification] [inspection] is the same as that of medicinal materials.
. Mash when needed.
This product is shaped like bitter almond, with a yellow to brownish yellow surface and slight focal spots. It has aroma and bitter taste.
[content determination] the content of amygdalin (c20h27no11) in the same medicinal material shall not be less than 2.1%.
[identification] [inspection] is the same as that of medicinal materials.
; . Return to lung and large intestine channels.
[functions and indications] it can reduce Qi, relieve cough and asthma, moisten the intestine and relieve constipation. For cough and asthma, chest full of phlegm, intestinal dryness and constipation.
[usage and dosage] 5 ～ 10g, put the raw product into the decoction and then put it down.
[note] do not take too much orally to avoid poisoning.
[storage] store in a cool and dry place to prevent moths.

2、 Chemical constituents of bitter almond

containAmygdalin（amygdalin）、 Fatty oil, emulsin, amygdalase, prunase, estrone, α - estradiol, streptosterol, etc.

3、 Pharmacological effects of bitter almond

1. Antitussive and antiasthmatic effects
Amygdalin is contained in bitter almond. Amygdalin can be hydrolyzed by intestinal microbial enzymes or bitter almond enzymes contained in bitter almond itself in vivo to produce trace amounts of hydrocyanic acid and benzaldehyde, which can inhibit the respiratory center and achieve antitussive and antiasthmatic effects. "Seeking truth from Materia Medica" records that "almonds have the ability to disperse wind and cold, and then have the ability to breathe and remove asthma". It is good at relieving cough, resolving phlegm and relieving asthma, and has strong pertinence to the main diseases of the lung system, such as cough, phlegm and wheeze. Therefore, ancient and modern physicians used it as a medicine for the lung system, regardless of internal injury, external infection, new and chronic diseases, which involve the lung. In vitro organ test of guinea pigs, almond water extract can reduce the sensitivity of organs to ammonia stimulation, resist the excitatory effect of histamine, acetylcholine and barium chloride on tracheal smooth muscle, and has obvious antitussive effect. According to the method of SO2 induced cough, the inhibition rates of amygdalin 1mg/kg, 10mg/kg and 100mg/kg on cough frequency were 26%, 22.8% and 25.3% respectively after intragastric administration of amygdalin 1mg/kg, 10mg/kg and 100mg/kg for 30min. The effect of 48.3mg/kg bitter almond extract by gavage was 39.7% stronger than that of the same amount of amygdalin. Bitter almond is beneficial to lung respiratory function because it can promote the synthesis of pulmonary surfactant (PS). Bitter almond can not only promote the synthesis of PS, but also improve various physiological and biochemical indicators related to the lung (such as lung homogenate, lung water volume, total phospholipids in bronchial lavage and pathological slices, etc.).

2. Effect on digestive system
Almond taste bitter breath, and rich in fatty oil. . Amygdalin is enzymatically decomposed to form hydrocyanic acid, while it also produces benzaldehyde, which can inhibit the activity of pepsin, thus affecting the digestive function. The pepsin hydrolysate from the water-soluble part of almond was administered at a dose of 500mg/kg to carbon tetrachloride treated rats, and it was found that it could inhibit the increase of AST, ALT levels and hydroxyproline content, and inhibit the prolongation of euglobulin dissolution time. The pepsin hydrolysate from the water-soluble part of almond could inhibit the proliferation of connective tissue in rat liver, but could not inhibit the increase of AST and ALT levels caused by D-galactosamine.

3. Anti inflammatory and analgesic effects
The water extract of defatted bitter almond has inhibitory effects on acetic acid-induced writhing reaction in mice and cotton ball induced granuloma inflammation in rats. Using rat foot joint edema method, intravenous injection of 40mg/kg almond water-soluble protein components kr-a, kr-b5mg/kg can inhibit inflammation. The pain model test with naphthoquinone in mice showed that when kr-a or kr-b were administered intravenously at 5mg/kg, the pain inhibition rates were 40.7% and 58.2%, respectively. Their oral ED50 for carrageenan induced foot swelling in rats were 13.9mg/kg and 6.4mg/kg, respectively. The hot plate method and acetic acid writhing method in mice confirmed that amygdalin had analgesic effect, but it was different from morphine analgesic. . Benzoin has analgesic effect, so some people in China use bitter almond to treat advanced liver cancer can relieve the pain of patients, some even do not need to take pain medication.

4. Antitumor effect
Amygdalin was first isolated from almond in the early 20th century, and it was first used in the United States in 1920 to treat tumors. Dr. Ernest Krebs was the first person to use amygdalin in medicine in the United States and called it vitamin B17. Since the 1950s, amygdalin has been widely used in the United States, Mexico and other countries to treat tumors. Its trade name is vitamin B17 or Laetrile, but the anti-tumor effect of amygdalin has not been recognized by FDA. There has been controversy in the academic community, and there are two completely opposite views. The party in favor believes that amygdalin is a vitamin B17, which has the effect of preventing and treating tumors, and puts forward some theoretical and experimental data. If it is believed that the anaerobic degradation of tumor cells is dominant, and the final product is lactic acid, the acidic environment is conducive to improving the activity of β - glucosidase, prompting amygdalin to decompose more benzaldehyde and hydrocyanic acid in tumor cells, resulting in selective killing effect on tumor cells. Contrary to this view, amygdalin is not a vitamin at all, has no anticancer effect, and is even a toxic substance. .