Rag leaf
1、 Pharmacopoeia standard of rag leaf       This product is Microcos paniculata L, a rag leaf of Tiliaceae. . Harvest in summer and autumn, remove branches and impurities, and dry in the shade or in the sun.
      [character] this product is often wrinkled or broken. After flattening, the intact leaves are oval oblong or oval rectangular round, 8-18cm long and 4-8cm wide. The surface is yellowish green, greenish brown or yellowish brown. Apex acuminate, base obtuse, slightly oblique, margin denticulate. Basal veins 3, lateral veins pinnate, venules reticulate. Petiole short, veins and petioles pilose. Paper, fragile. .
      [identification] (1) the powder of this product is yellowish green. Epidermal cells are polygonal or round. Air hole infinitive. Secretory cells are round like and contain yellowish brown secretions. There are two kinds of non glandular hairs: one kind of stellate hair, with many branches and several partitions in each branch; Another non glandular hair single cell. . The fibers are slender, in bundles, with slightly thick walls and clear pits. Calcium oxalate crystals are common; The diameter of calcium oxalate cluster crystals is 5 ～ 20 μ M.
      (2) Take 1g of the product powder, add 50ml of water, heat and reflux for 2 hours, filter, concentrate the filtrate to 30ml, extract twice with ethyl acetate (30ml, 25ml), combine the ethyl acetate solution, evaporate to dryness, add 1ml of absolute ethanol to dissolve the residue, and use it as the test solution. Another 1g of the reference medicinal material of rag residue leaves was taken and made into the reference medicinal material solution by the same method. Test according to thin-layer chromatography (general rule 0502), suck 2 μ l of each of the above two solutions, dot them on the same silica gel G thin-layer plate respectively, use dichloromethane butanone formic acid water (10:1:0.1:0.1) as the developing agent, develop, take out, dry, and view under ultraviolet light (365nm). .
      ; Not more than 2% (general rule 2301).
      Moisture   Not more than 12.0% (the second method of general rule 0832).
      Total ash   Not more than 8.0% (general rule 2302).
      [extract] according to the hot leaching method under the alcohol soluble extract determination method (general rule 2201), using dilute ethanol as solvent, it shall not be less than 17.0%.
      [content determination] determine according to HPLC (general rule 0512).
      ; Octadecylsilane bonded silica gel was used as filler; The mobile phase was methanol-0.4% phosphoric acid solution (30:70); The detection wavelength was 339nm. The number of theoretical plates should not be less than 3000 according to the peak of Vitexin.
      Preparation of reference solution   .
      Preparation of test solution   Take about 2.5G of this product powder (passing through No. 3 screen), weigh it precisely, place it in a corked conical flask, add 50ml of 70% methanol precisely, close the stopper, weigh it, sonicate (power 250W, frequency 33khz) for 1 hour, cool it, weigh it again, make up the lost weight with 70% methanol, shake it well, filter it, and take the filtrate.
      Assay   Precisely suck 10 μ l of the reference solution and 10 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 Vitexin (c21h20o10) shall not be less than 0.040%.
      [nature, taste and meridian tropism] slightly sour, cool. Return to spleen and stomach meridian.
      . For food stagnation, cold fever, damp heat jaundice.
      [usage and dosage] 15 ～ 30g.
      [storage] put it in a dry place.


2、 Chemical constituents of rag leaves
Twelve compounds were isolated and identified asIsorhamnetin①、Kaempferol②、Isovanillic acid③ , p-coumaric acid ④Ferulic acid⑤ , abscisic acid ⑥Vitexin ⑦、Isovitexin⑧、Narcissus glycoside⑨、Isorhamnetin-3-o-glucoside⑩ , isofraxin (11)Epicatechin（12）

3、 Pharmacological effects of leaves of rag residue
Rag leaf, also known as rag leaf, rag residue, hemp, Camellia leaf, etc., is a commonly used herbal medicine in the south of the five ridges. The dried leaves of the rag leaf microcospaniculata, a plant in the Tiliaceae family, are used as medicine. It has the effects of clearing heat and eliminating stagnation, promoting dampness and eliminating jaundice. It is mainly used for cold, abdominal pain caused by damp heat and food stagnation, diarrhea caused by less food, and damp heat jaundice. The medicinal history of rag leaf was first seen in the Lingnan herbal book "preparation of raw herbs" written by he Kejian in the Qing Dynasty. In this book, it contains the Lingnan Chinese herbal medicine "rag leaf" which is commonly used as a tea drink for the purpose of clearing heat and detoxification, and contains it: "it tastes sour, has a flat nature, is non-toxic, relieves all Gu bloating, clears yellow gas, eliminates heat and toxin. It is used as a tea drink to remove food accumulation. It is also known as rag leaf". Later, another Lingnan herbal monograph "materia medica for the original" published in the 28th year of Daoguang (1848 AD) was collected under the correct name of "ragged leaves", saying, "that is, ragged leaves, sour, sweet, and peaceful. It can relieve all the poison of Gu Zhang medicine, clear away heat, eliminate food accumulation, and jaundice. It is good for drinking tea. ”In addition, the "Guangdong Tongzhi" describes that "rag leaves come out of the Enping of Yangjiang Yangchun, shaped like palm and green, used by people on boats in the south of the five ridges, addicted to cigarette poison and water, and can be decocted in soup.". Later, it was recorded in the records of Lingnan herbal medicine, Luchuan materia medica and the manual of Chinese herbal medicine in Guangdong and Guangxi. . Although various literatures recorded the drug with different names, the source of the drug is the same plant, so it can be confirmed that the drug recorded in various literatures is the same medicinal material. Since ancient times, the leaves of cloth dregs have been widely used in the folk in Lingnan region of China. The folk often use the leaves of cloth dregs to fry tea as a summer drink, which has the effect of quenching thirst and appetizing.

The application of rag leaves in modern TCM clinic is relatively rare, and its application is mainly concentrated in Lingnan folk tea drinks and some enterprises making health herbal tea. Some modern Chinese medicine monographs have detailed records on cloth dregs, such as the Guangdong provincial standard of Chinese medicinal materials, Chinese Materia Medica, and so on. The functions of the two are basically the same. The main functions are to clear away heat, eliminate stagnation, and promote diuresis; . The nature and taste of the other two are quite different. The former contains: "rag leaves are sweet, light and slightly cold", while the latter contains: "rag leaves are sour, light and flat". It is worth further discussion.

Rag residue leaf is mainly used for the treatment of cold, jaundice, abdominal pain, centipede bite and other diseases in Lingnan area. ① For the treatment of cold, indigestion and abdominal distension: 15 ～ 30g of rag leaves, decocted in water; Or 18G of rag leaf, guava leaf and Polygonum hydropiper, decocted in water, 2 doses a day. ② Treatment of centipede bite: 15 ～ 30g of rag leaves, decocted in water. ③ Treatment of jaundice: 60g of rag leaves, 60g of pig blood, decocted in water, once a day, for 6 days; . ④ Treatment of melon and vine sores: cloth residue leaves, duck foot wood leaves, grass melon dill, beef dill, salt, appropriate amount of each flavor. Mash it and stir fry it with cow urine, apply it to the affected area while it is slightly cool, and then cook the duck with high grain millet stalks. ⑤ Treatment of abdominal pain due to heat stagnation: rag leaf, duck foot bark, cow leaf, Acanthus ilicifolius root, Prunus davidii root, and the same amount of each drug. Each use 120-320g, water decocted for tea.

Guangdong is located in the south of the five ridges. It has a hot climate and low terrain, especially in the Pearl River Delta. It is surrounded by mountains on three sides and faces the sea on one side. Due to the special geographical and climatic characteristics, it is prone to the so-called "hot air" phenomenon, such as sore throat, sore throat, acne on the face, swollen gums and other "hot air" manifestations. However, many Chinese herbal medicines in Guangdong have a good "antipyretic" effect. Among them, rag leaf is a good raw material for making health herbal tea, and it is widely used in folk.