Density | 1.48[at 20℃] |
Boling Point | 160℃[at 101 325 Pa] |
Water Solubility | 50mg/L at 20℃ |
Vapor Presure | 0.002Pa at 71℃ |
Physical and Chemical Properties | 10-30% specifications for the brown fine powder, 50-80% for light yellow or off-white powder, 95-99% specifications to off-white to white crystalline powder. odor and taste: special odor, very bitter taste. solubility: soluble in water, slightly soluble in methanol, ethanol, ethyl acetate, insoluble in benzene, petroleum ether. optical rotation:-62.5 °. Melting Point: 197-200 °c. detection method: High performance liquid chromatography (HPLC). |
plant extract | at the beginning of the 19th century, a French chemist extracted an active substance salicyloside Salicin from white willow bark, which is a natural antipyretic and analgesic drug. white willow bark extract is made of white willow Salix alba l. as raw material, commercial extract is usually standardized to contain salicylic glycoside 40% or 80%. White willow peel extract and garlic extract, Coptis chinensis extract, pomegranate peel extract, and cordata extract are all plant extracts of anti-pathogenic microorganisms. [raw drug resources] white willow skin is mainly produced in Europe, most of them are in southwest Europe, and both Britain and Yugoslavia are produced. Weeping willow Salix babylonica L. branches and willow white skin all contain salicylic glycosides, which are born in waterside wetlands and are distributed in the Yangtze River Basin and all parts of South China; the white skin of water poplar is the endothelium of red willow Salix purpurea L. The bark of Levet Vut gymmolepis salicylic glycosides. [harvesting and processing] the harvesting method of white willow bark is usually peeling bark, air drying or fast drying. Figure 1 shows white willow bark extract. |
crude drug ingredients | the main active ingredients of white willow bark extract are phenolic glycosides and flavonoid glycosides, phenolic glycosides include salicylin Salicin, salicylin Salicortin, aspen glycosides Tremulacin, Fragilin, salicoysalicin glycosides and salireposide glycosides. fig. 2 is the chemical structural formula of salicylate. |
quality of medicinal materials | white willow skin is the dry bark of white willow Salix alba L. Properties: The length is variable, the width is 1 ~ 2cm, the thickness is 1 ~ 2cm, the outer surface of the tender willow skin is brownish green, smooth, and slightly longitudinal wrinkles; the old skin is brownish yellow to brownish black, with rough surface and irregular wrinkles; the inner surface is light yellowish brown to dark cinnamon brown, to grayish brown, with neat longitudinal stripes. The fibers in the inner part are broken, short and inconspicuous, and easy to crack into longitudinal strips. Microscopic identification: thick skin and 2~3 rows of hypoplastic cork cells, thick horn tissue and soft tissue cell skin containing calcium oxalate crystal clusters, diameter 20~25 μm, tannic acid; phloem is characterized by lignified fibers and crystal sheaths containing prismatic calcium oxalate crystals. There are single and round starch grains in phloem and soft tissue cells in myelin rays with a diameter of 6~8 μm. Thin layer identification: take 1g of medicinal powder, extract it with 10ml methanol in water bath for 10-15 minutes, cool it, and filter it to obtain the test solution; Prepare 0.05mg/100ml salicyloside reference substance solution. The two solutions are respectively laid on the same silica gel G thin-layer plate, unfolded with a developing agent (1% iodine and 1% potassium iodide 96% ethanol solution, respectively added to an equal volume of 96% ethanol and 8M hydrochloric acid mixture), taken out, dried, heated at 105 ℃ for 5-10 minutes, examined under sunlight, relative to the main spots Rf of salicylic glycoside: red 2.0, red 1.1, brown-green 0.7. Foreign substances: not more than 3%. Total ash: no 10%. Acid insoluble ash: not more than 3%. Water extract: not less than 10%. Determination of content: this product is based on dry products and contains salicylic glycosides not less than 2.5%. |
extraction method | take the original medicinal materials, cut them into 1~2cm, mix with appropriate amount of calcium carbonate powder, add water at 60 ℃ for continuous countercurrent extraction, keep the running time of the materials in the extraction chamber for 1 hour, concentrate the extracted liquid under reduced pressure below 60 ℃ to 3 times the volume of the medicinal materials, add lead acetate saturated aqueous solution, stir well, and filter, add an appropriate amount of calcium carbonate powder to the filtrate, pass in hydrogen sulfide to remove lead and filter, add calcium carbonate powder to the filtrate, and concentrate into syrup under reduced pressure below 60 ℃, and the degreasing residue is soaked with ethyl acetate. The ethyl acetate leachate is recovered under reduced pressure. |
analytical method | 1, chromatographic conditions and system applicability test: ODS2 C18 5u 4.6mm × 200mm chromatographic column; Acetonitrile: 0.1% phosphoric acid (5:95) is the mobile phase; Detection wavelength: 280nm; Flow rate: 1 ml/min. The number of theoretical plates is not less than 2200 based on salicylic glycosides. 2. preparation of reference substance solution: precisely weigh salicylic glycoside about 15mg, dissolve it with methanol ultrasonically, and fix the volume in a 10ml volumetric flask, which is the standard reference substance solution. 3. preparation of the test solution: accurately weigh about 500mg of the extract, place it in a 50ml volumetric flask, add 35ml of methanol, ultrasonic extraction for 30 minutes, place it at room temperature with methanol for constant volume. 0.45 μm microporous filter membrane filtration, that is, the test solution. 4. determination method: inject 10 μl of sample test solution and 10 μl of reference solution into HPLC instrument respectively, and calculate by area external standard method. |
pharmacological effects | the main pharmacological effects of white willow bark extract are antipyretic, analgesic and anti-inflammatory. The active ingredients are phenolic glycosides and flavonoid glycosides, and the most prominent ingredient is salicylic glycosides. Salicylic acid is hydrolyzed into salicylic acid, which is a weak anti-inflammatory agent. It is converted into acetylsalicylic acid in the liver. The anti-inflammatory effect is enhanced, and it has antipyretic and analgesic effects, but it has no toxic effect on the intestines and stomach. 1. Treatment of fever, colds and infections Salicylic glycosides, the active ingredient of Bailiu bark extract, is called "natural aspirin" and can be used to treat mild fever, colds, infections (influenza), acute and chronic rheumatic discomfort, headache and pain caused by inflammation. Aspirin (acetylsalicylic acid), as a synthetic substitute for salicylic glycosides, has potential gastrointestinal dangerous side effects. As its natural configuration, salicylic glycosides can be converted into salicylic acid in blood and liver through the gastrointestinal system harmlessly. The transformation process takes several hours, so the results will not be immediately felt by the human body, but the general efficacy will last for several hours. 2. relieve arthritic pain and back pain salicylic glycosides are considered to be the source of anti-inflammatory and pain-relieving ability of white willow skin. The analgesic ability of white willow skin usually takes effect slowly but lasts longer than the effect of ordinary aspirin products. A trial found that a class of herbal compound products containing 100ng of salicylic glycosides can effectively improve the analgesic ability of arthritis patients after continuous administration for two months. Another trial found that a daily intake of 1360mg of white willow bark extract (containing 240mg salicyloside) for two weeks was more effective in treating joint pain and/or arthritis. The use of high-dose white willow bark extract may also help relieve back pain. A four-week trial found that the extract of white willow bark containing 240mg salicylin can effectively reduce the deterioration of low back pain. |
clinical efficacy | white willow bark extract is mainly used for antipyretic and analgesic. 210 patients with chronic low back pain (more than half) received a placebo comparative study and were randomly assigned to receive low-dose (120mg/day) or high-dose (240mg/day) or placebo treatment with white willow skin extract. If necessary, patients are allowed to supplement a pain relief drug with 400mg of tramamphenicol a day. 91% of patients completed the test, and the result of the test was that the white willow skin extract relieved the pain. When not treated with trans-aminophenyl alcohol, a certain proportion of patients whose pain was eliminated in the last week to at least 5 days, and a certain proportion of patients who needed to take trans-aminophenyl alcohol at the beginning of the study period. According to the test results, the pain was relieved in the high-dose group 39% the first week of treatment, 21% in the low-dose group and only 6% in the placebo group. The pain in the high-dose group was significantly relieved after one week of treatment, while patients in the placebo group needed to take trans-aminophenol for relief throughout the trial. All three experimental groups had very mild adverse reactions, some of which may be the reaction of trans-aminophenol, and one of the low-dose groups had allergic reactions (eye swelling, itching), which may be caused by drug treatment. |
application overview | for a long time, people have used white willow skin to relieve pain, antipyretic and anti-inflammatory. In addition, the glycosides in the white willow bark have a astringent effect and can be used as an astringent. In addition to the preparation of the above efficacy, white willow bark extract can also be used for skin care, dandruff removal and promotion. 1, in the field of cosmetics, it is mainly used to suppress acne, prevent acne, reduce swelling and relieve pain. 2, it is mainly used to treat fever, cold and infection in the field of medicine. 3, mainly used in the field of natural feed additives to reduce inflammation and help digestion. |