Stave plate return
1、 The bar and plate belong to the pharmacopoeia standard         This product is the dry aboveground part of Polygonum perfoliatuml. In summer, flowers are harvested and dried in the sun.
        [character] the stem of this product is slightly square columnar, angular, multi branched, with a diameter of 0.2cm; the surface is purplish red or purplish brown, there are inverted barbs on the edges and corners, the nodes are slightly expanded, the internode is 2-6cm long, the cross section is fibrous, yellowish white, myelinated or hollow. Leaves alternate, long stalked, peltate; The leaves are mostly wrinkled, flattened and nearly equilateral triangular, grayish green to reddish brown, with inverted barbs on the lower surface veins and petioles; The stipule sheath is wrapped on the stem node or falls off. . The air is weak, the stem tastes light, and the leaves taste sour.
        [identification] (1) cross section of the stem of this product: the epidermis is a row of cells. . The fiber bundles of the columella are continuously looped, and the cell wall is thick and lignified. The older stems of phloem have phloem fibers, with thick walls and lignification. The cambium is obvious. Xylem vessels are large, single or in groups of 3-5. Myeloid cells are large and sometimes form cavities. Most calcium oxalate clusters can be seen in the cortex, phloem, ray and pith of old stems, but rare or absent in young stems. The epidermal and cortical cells of the old stem contain reddish brown substances.
        Leaf surface view: the upper epidermal cells are irregular polygonal, and the vertical circumferential wall is nearly straight or slightly curved. The wall of the lower epidermis was wavy; . . Mesophyll cells contain calcium oxalate clusters with a diameter of 17-62 μ M.
        (2) Take 2G of this product powder, add 50ml of petroleum ether (60 ～ 90 ℃), sonicate for 30 minutes, filter, discard the petroleum ether solution, volatilize the solvent from the drug residue, heat 25ml of water, put it in a 80 ℃ water bath for 30 minutes, shake from time to time, take it out, filter while hot, add 1 drop of dilute hydrochloric acid to the filtrate, shake and extract twice with ethyl acetate, 30ml each time, combine the ethyl acetate solution, evaporate to dryness, add 1ml of methanol to dissolve the residue, and use it as the test solution. Take caffeic acid reference substance and add methanol to make a solution containing 0.5mg per 1ml as the reference substance solution. Test according to thin-layer chromatography (general rule 0502), suck 5-10 μ l of the test solution and 5 μ l of the control solution, respectively dot them on the same silica gel G thin-layer plate, use toluene ethyl acetate formic acid (5:3:1) as the developing agent, develop, take out, dry, and view 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.
        [check] moisture   Not more than 13.0% (the second method of general rule 0832).
        Total ash   Not more than 10.0% (general rule 2302).
        .
        [content determination] determine according to HPLC (general rule 0512).
        Chromatographic conditions and system suitability test octadecylsilane bonded silica gel was used as filler; The mobile phase was methanol-0.4% phosphoric acid solution (50:50); The detection wavelength is 360nm. The number of theoretical plates should not be less than 3000 according to the quercetin peak.
        Preparation of reference solution take an appropriate amount of quercetin reference, weigh accurately, and add methanol to make a solution containing 30 μ g per 1ml.
        Preparation of the test solution take about 0.7G of the powder (passing through No. 3 screen), accurately weigh it, place it in a corked conical flask, precisely add 50ml of methanol hydrochloric acid (4:1) mixed solution, weigh it, put it in a 90 ℃ water bath, heat and reflux for 1 hour, cool it, weigh it again, use methanol to make up the lost weight, shake it well, filter it, 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 quercetin (C15H10O7) shall not be less than 0.15%.
        Decoction pieces
        [processing] remove impurities, wash slightly, cut into sections, and dry.
        [nature, taste and meridian tropism] sour, slightly cold. Return to lung and bladder meridian.
        . It is used for sore throat, lung heat cough, children's sudden cough, edema and less urine, damp heat diarrhea, eczema, furuncle, snake and insect bite.
        [usage and dosage] 15 ～ 30g. For external use, use an appropriate amount, decoct the soup, smoke and wash.
        [storage] put it in a dry place.

2、 Chemical constituents of Periploca
It contains indoside, persicarinP-hydroxyphenylacrylic acid（p-coumaric acid）Ferulic acid、Vanillic acid、Protocatechuic acid（protocatechuic acid）、caffeic acid（caffeic acid）。

3、 Pharmacological effects of Periploca
It can promote diuresis, reduce swelling, clear away heat, detoxify and relieve cough. For nephritis edema, pertussis, diarrhea, eczema, furuncle, snake bite.