Belladonna
1、 Belladonna herbal classic standard       This product is the dried whole grass of belladonna L., a nightshade plant. Excavate during the period from flowering to fruiting, remove thick stems and sediment, and cut sections to dry.
      ; The old root is woody, the fine root is easy to break, the cross section is flat, the skin is narrow, gray white, the xylem is broad, brown yellow, and the cambium ring is obvious; Pulp white. The stem is oblate cylindrical, with a diameter of 3-6mm. The surface is yellowish green, with fine longitudinal wrinkles and sparse fine punctate skin like holes. It is hollow, and the young stem is hairy. The leaves are mostly shrunken and broken, and the complete leaves are oval, yellowish green to dark brown. Calyx 5-lobed, corolla bell shaped. The fruit is spherical, 5-8mm in diameter, with long stems and most seeds. It is slightly bitter and pungent.
      [identification] (1) the powder of this product is light green or light brownish green. There are many calcium oxalate sand crystals with a diameter of 3 ～ lo μ m, and some clusters with a diameter of 15 ～ 28 μ M can be seen in the sand crystal containing cells. Leaf epidermal cells have wavy circumferential walls with cuticular stripes; . Glandular hairs have single cells in the head, 2-4 cells in the stalk, or 5-6 cells in the head and single cells in the stalk. The starch grains are rare, with a diameter of 8-26 μ M. The vessels with marginal pits and reticulated ducts are 24-40 μ m in diameter. Wood fibers, wavy and curved seed coat stone cells and pollen grains can also be seen.
      (2) Take 4G of this product powder, add 15ml of ethanol, and shake for 15 minutes. Filter, evaporate the filtrate to dryness, add 2ml of sulfuric acid solution (L → 100), mix and filter, add ammonia test solution to the filtrate to make it alkaline, and then use 2ml of trichloromethane to shake and extract, separate the trichloromethane solution, evaporate to dryness, and the residue shows the identification reaction of alkaloids (general rule 0301).
      (3) Take 2G of this product powder, add 2ml of concentrated ammonia test solution, mix well, add 25ml of trichloromethane, shake well, place overnight, filter, evaporate the filtrate, add 0.5ml of trichloromethane to dissolve the residue as the test 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] not more than 4% of belladonna leaves with abnormal color (yellow, brown or near black) and not more than 3% of belladonna stems with a diameter of more than 1cm (general rule 2301).
      The moisture content shall not exceed 13.0% (the second method of general rule 0832).
    [content determination] take about 10g of powder in this product, weigh it accurately, put it in Soxhlet extractor, add 10ml of ethanol, 8ml of concentrated ammonia test solution and 20ml of ether, stand for 12 hours, add 70ml of ether, heat and reflux for 3 hours, until the alkaloids are extracted, evaporate most of the ether on the extraction solution in a water bath, transfer it to a separatory funnel, shake and extract with 0.5mol/l sulfuric acid solution in several times, 10ml each time, until the alkaloids are extracted, combine the acid solution, shake and extract with trichloromethane in several times, 10ml each time, until the trichloromethane layer is colorless, combine the trichloromethane solution, and use 0.5mol/l sulfuric acid.Shake 10ml of the solution for extraction, discard the trichloromethane solution, combine the acid solution before and after two times, filter, and use 0.5mol/l of the filtrate Wash the sulfuric acid solution, combine the washing solution and filtrate, add excess concentrated ammonia test solution to make it alkaline, and quickly use chloroform to shake and extract in several times until the alkaloids are extracted. In case of emulsification, add a few drops of ethanol, wash the trichloromethane solution obtained each time with 10ml of the same water, discard the washing solution, combine the trichloromethane solution, evaporate to dryness, add 3ml of ethanol, evaporate to dryness, and dry at 80 ℃ for 2 hours. Add 2ml of trichloromethane to the residue, if necessary, dissolve it with slight heat, add 20ml of sulfuric acid titrant (0.01mol/l), heat it in a water bath, remove the trichloromethane, cool it, add 1-2 drops of methyl red indicator solution, and titrate it with sodium hydroxide titrant (0.02mol/l). Every 1ml of sulfuric acid titrant (0.01mol/l) is equivalent to 5.788mg of hyoscyamine (c17h23no3).
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      [purpose] anticholinergic drug.
      [storage] put it in a dry place.


2、 Chemical constituents of belladonna
Leaf containsScopolamine（scopolamine)， Tianxianziamine (old nameHyoscyamine）(hyoscyamine) [1], atropine [2], jupscua, omen oxide [3], hyoschin N-oxide [4]. It also contains flavonoids: 7-methylquercetin, 3-Methylquercetin [5], quercetin-3-rhamnoglucoside, kaempferol-3-rhamnogalacto side,Quercetin-7-0-glucoside（prercitin-7-glucoside)，Kaempferol-7-o-glucoside（Kaempferol-7-O-beta-D-glucopyranoside)， Quercetin-7-glucosyl-3-rhamnogalactoside, quercetin-7-glucosyl-3-rhamnogalactoside, quercetin-7-glucosyl-3-rhamnogalactoside, kamepferol-7-glucosyl-3-rhamnogalactoside, Kaempferol-7-glucosyl-3-rhamnoglucoside [6].
The root contains atropine [7], cucohygrine [8], and N-oxide of asparagine [3].

3、 Pharmacological effects of belladonna
1. action of atropine: similar to scopolamine, in addition to the central action, their peripheral action is widely used, that is, a series of effects produced by blocking the action of acetylcholine on m-choline receptor. Here, atropine is taken as a representative to briefly describe its role.
1.1 gland secretion: it can inhibit the secretion of sweat and salivary glands, cause dry skin and dry mouth, and also reduce the secretion of respiratory tract, so it is often used for pre anesthesia administration, and a larger dose can reduce gastric secretion.
1.2 smooth muscle: it has little effect on normal movement of gastrointestinal tract, but it has obvious spasmolytic effect on smooth muscle in excessive movement and spasm, and has spasmolytic effect on gastrointestinal tract, biliary tract, ureter and bronchospasm.
1.3 eye: paralyze iris sphincter and ciliary muscle, produce pupil dilation and adjust paralysis (hyperopia).
1.4 cardiovascular system: small doses cause transient heart rate slowing due to excitation of the vagus nerve center; ; Large doses have direct effects on small blood vessels and capillary smooth muscle, dilate blood vessels, increase blood flow of important organs, improve blood circulation, and are used to treat shock.
1.5 central nervous system: excite the medulla oblongata and brain. The clinical dose of 0.5-1.0mg slightly excites the respiratory center. At the toxic dose, there is obvious central excitation, restlessness, agitation, juvenile sensation and delirium, etc. at the larger dose, it is first excited and then inhibited, and finally dies of bulbar paralysis. It has an antagonistic effect on the tremor caused by the injury of the thalamus base and midbrain reticular formation in monkeys. Inhibiting the spontaneous and speed changing discharges of vestibular neurons in cats, that is, inhibiting the excitability of vestibular neurons, has antiemetic effect.
2. action characteristics of scopolamine (compared with atropine): 2.1 the effect of scopolamine on iris, ciliary muscle and some exocrine glands (salivary gland, bronchial gland and sweat gland) is much stronger than that of atropine, while the effect of atropine on heart, intestinal tube and bronchial smooth muscle is more significant and lasting.
2.2 it has strong respiratory excitatory effect on normal people. Increasing the respiratory rate and ventilation can resist the respiratory depression caused by morphine, but when the respiration is severely inhibited, the effect is unreliable. The effect on the high-level brain center is opposite to that of atropine, which is mainly inhibition rather than excitation. When the therapeutic dose is used, it will cause drowsiness, euphoria, forgetfulness, fatigue and even sleep. Increasing the dose can produce anesthetic effect.
2.3 effect on gland secretion: atropine can inhibit the secretion of sweat and salivary glands, cause dry skin and dry mouth, and also reduce the secretion of respiratory tract, so it is often used for pre anesthesia administration, and a larger dose can reduce the secretion of stomach. Scopolamine has a much stronger inhibitory effect on some exocrine glands than atropine.
2.4 effect on smooth muscle: Atropine has little effect on the normal movement of gastrointestinal tract, but it has obvious spasmolytic effect on smooth muscle in excessive movement and spasm, and has spasmolytic effect on the spasm of gastrointestinal tract, biliary tract, ureter and bronchus. In addition, atropine can paralyze the iris sphincter and ciliary muscles of the eye, produce pupil dilation and regulate paralysis (hyperopia). The effect of scopolamine on the smooth muscle of heart, intestine and bronchus is not as strong and lasting as that of atropine. The effect on iris and ciliary muscle is much stronger than atropine.
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