CN108042661B

CN108042661B - White tea extract rich in dihydromyricetin and application thereof in preparing medical health products

Info

Publication number: CN108042661B
Application number: CN201711353161.9A
Authority: CN
Inventors: 傅金荣
Original assignee: Jiangxi Tianyuan Medicine Co ltd
Current assignee: Jiangxi Tianyuan Medicine Co ltd
Priority date: 2017-12-16
Filing date: 2017-12-16
Publication date: 2021-01-19
Anticipated expiration: 2037-12-16
Also published as: CN108042661A

Abstract

The invention relates to a white tea extract rich in dihydromyricetin and application thereof in preparing medical health products. In particular, one aspect relates to a method of preparing an extract comprising the steps of: pulverizing leaves of Ampelopsis plant, and decocting with water; concentrating under reduced pressure, adding ethanol, standing, filtering to remove solid; concentrating under reduced pressure until no alcohol smell is present, and drying. Also relates to white tea extract, its composition and application. The white tea extract rich in dihydromyricetin can be used for scavenging free radicals, resisting oxidation, resisting thrombus, resisting tumor, resisting bacteria and diminishing inflammation, relieving alcoholism and relieving alcoholism, preventing alcoholic liver and fatty liver, inhibiting hepatocyte deterioration, reducing incidence of liver cancer, resisting hypertension, inhibiting in vitro platelet aggregation and in vivo thrombus formation, reducing blood fat and blood sugar levels, improving SOD activity, protecting liver, activating AMPK, inhibiting hyperglycemia-induced vascular endothelial cell apoptosis, inhibiting liver lipopexia, inhibiting hepatic stellate cell activation, inhibiting lung adenocarcinoma cell proliferation, hypnotizing and resisting fatigue.

Description

White tea extract rich in dihydromyricetin and application thereof in preparing medical health products

Technical Field

The invention belongs to the field of medical health products, and relates to a plant extract rich in dihydromyricetin, in particular to an extract rich in dihydromyricetin (the extract rich in dihydromyricetin extracted from the leaves of two ampelopsis plants is commonly called white tea in the field) extracted from the leaves of ampelopsis grossedentata or ampelopsis grossedentata (the leaves of the two ampelopsis plants are commonly called white tea in the field), the extract has excellent biological functions, in particular to the functions of treatment, prevention and health care, and has various peculiar efficacies of free radical scavenging, antioxidation, antithrombotic, antitumor, antiphlogosis and the like; wherein, the dihydromyricetin is a special flavonoid compound, and has special effects on relieving alcoholism, preventing alcoholic liver and fatty liver, inhibiting hepatocyte deterioration, reducing incidence rate of liver cancer, resisting hypertension, inhibiting in vitro platelet aggregation and in vivo thrombosis, reducing blood lipid and blood sugar levels, improving SOD activity, protecting liver, etc. The invention also relates to said extracts and compositions containing them, to processes for preparing these extracts and compositions, and to the medical use of these extracts and compositions.

Background

Ampelopsis grossedentata (Ampelopsis grossedentata, also commonly called tea) is a Vitaceae Ampelopsis plant, and is used as a medicine-food homologous plant by using the leaf thereof, for example, according to the related regulations of the food safety law of the people's republic of China and the safety examination and management method of new food raw materials, the leaf of Ampelopsis grossedentata has been approved as a new food raw material in 24 and 12 months in 2013 by the Ministry of health Commission (No. 16 in 2013), and the Ampelopsis grossedentata total flavone buccal tablet (1 g in weight and 0.3g in total flavone in Ampelopsis grossedentata) prepared from Ampelopsis grossedentata is as an OTC medicament, has the effects of relieving swelling and pain, detoxifying and restraining sores, and is clinically used for relieving the pain of the heart-spleen heat syndrome of recurrent aphtha ulcer (light and stomatitis type), the symptoms include aphtha of the mouth and tongue, local pain, red swelling, burning sensation, red face, dry mouth and nose, thirst with desire for drinking, dry stool, dark yellow urine, reddish and dry tongue tip, yellow or greasy coating, and wiry and rapid pulse. Similar plants of the genus Ampelopsis also the plant Ampelopsis megalophylla (Ampelopsis megalophylla Diels et Gilg, also commonly known as Ampelopsis grossedentata), which, like Ampelopsis grossedentata, contain large amounts of flavonoids, particularly dihydromyricetin.

The leaves of Ampelopsis grossedentata and Ampelopsis megalophylla are simply processed, for example, the common and conventional dried (for example, dried) products are also called as white monkey, white tea, white tippy, white hairy tea and the like, the main components of the extracted products are flavonoids, and the main components are different from various materials which are rich in flavonoids and also contain a large amount of tannic acid and have negative effects on the body, namely, the Ampelopsis grossedentata and the Ampelopsis megalophylla (namely, the white tea) do not contain tannic acid, can not influence the digestion and absorption of protein, can not capture iron which is used as a hematopoietic raw material in the body, and in addition, the Ampelopsis grossedentata also does not contain caffeine and other compounds with exciting effect, so the white tea is perhaps an ideal substitute for people with low quality of anemia, low sleep and the like and people who like drink tea but do. In addition, dihydromyricetin is a main chemical substance in flavonoids of ampelopsis grossedentata and ampelopsis grossedentata, and beneficial biological activities of dihydromyricetin have been widely studied by people.

Extracts from Ampelopsis grossedentata and Ampelopsis megalophylla that contain a large amount of flavonoids, particularly extracts rich in dihydromyricetin, which are also commonly referred to as white tea extracts, have been studied in a number of ways.

The influence of the tea water ratio, the extraction temperature, the extraction time and the sample leaf granularity on the total flavonoids of the Ampelopsis grossedentata and the water extraction rate is determined by respectively adopting a single-factor and orthogonal experiment L9(34) by taking the total flavonoids of water-soluble active ingredients and the water extraction rate as evaluation indexes for measuring the extraction effect, and the primary and secondary sequence of the influence is obtained by the Lizhonghai and the like (the Lizhonghai and the like, the influence of different extraction conditions on the total flavonoids of the Ampelopsis grossedentata and the water extraction rate, and the food industry science and technology, 2006 12). And the optimal extraction conditions for extracting the tea soup are provided by combining production practice as follows: the tea-water ratio is 1: 20. the extraction time is 20min, and the extraction temperature is 90 ℃. The leaching times experiment under the optimal leaching condition shows that the tea is easy to brew, and the first leaching rate of total flavone and water leaching rate reaches 75.87% and 80.56%.

Wu Shi (Wu Shi Yi, the shallow theory uses the flash extraction process to extract the effect of flavone in ampelopsis grossedentata, the current medical research, 2016 (05) period) uses an L9(34) orthogonal experimental method, uses rutin as a research index to measure the content of the flavone in the ampelopsis grossedentata, then uses an ultraviolet spectrophotometry flash extraction process to extract the flavone in the ampelopsis grossedentata leaves, 16 times of water is added during extraction, the extraction time is 3 min/time, and the extraction is continuously carried out for 2 times. Results and conclusions: the method for extracting the flavone from the ampelopsis grossedentata by using the flash extraction process has the advantages of simple operation, high extraction rate and the like. The method can be used as the preferred method for extracting flavone from Ampelopsis grossedentata.

Zhengcheng et al (Zhengcheng et al, investigation of mechanism of microwave-assisted enhanced extraction of dihydromyricetin from Ampelopsis grossedentata, reported in chemical industry, 2006, 05) uses the leaves of Ampelopsis grossedentata as raw material, adopts microwave to break cells for pretreatment, then adopts a hot water stirring method to extract dihydromyricetin from Ampelopsis grossedentata, observes the microcosmic conformation of the cells of the Ampelopsis grossedentata leaves by a transmission electron microscope, analyzes the microwave-assisted extraction mechanism by investigating the influence of different microwave irradiation conditions on the microstructure of plant leaves, and shows the results: when the microwave pretreatment time is 300W and 5min or the microwave power reaches 600W and the treatment time is 2min, the cell wall is folded and partially cracked, and then the cracking condition of the cell wall is more and more obvious along with the increase of the irradiation power and the extension of the microwave pretreatment time, which shows that the temperature of polar substances in the cell is rapidly increased after absorbing the microwave energy, so that the vapor pressure in the cell is rapidly increased, the expansion capability of the cell wall is exceeded, and finally the cell wall is cracked, so that the extraction and separation of effective components in the cell are easy.

Extracting total flavone from Ampelopsis grossedentata leaf with ultrasonic-assisted ethanol extraction method by Yangyin (Yangyin, et al, proceedings of Huai chemical institute, 11 years 2015) using dihydromyricetin as standard and AlCl as solvent₃The method is characterized in that the method comprises the following steps of (1) carrying out an L9(34) orthogonal test on the basis of a single-factor test, and respectively investigating the influence of ethanol concentration, material-liquid ratio, extraction time and ultrasonic treatment time on the extraction rate of the total flavonoids of the Ampelopsis grossedentata by taking the content of the total flavonoids as an index, wherein the results show that the optimal conditions for extracting the total flavonoids by the method are as follows: the ethanol concentration is 65%, and the feed-liquid ratio is 1: 40, leaching time of 30min, and ultrasonic treatment time of 20The main and secondary sequence influencing the extraction factors of the total flavone is ethanol concentration, ultrasonic treatment time, material-liquid ratio and extraction time, and the content of the total flavone is measured to be 41.25 percent under the optimal process.

Suzhouyu et al (Suzhouyu et al, star point design-effect surface method optimized ampelopsis grossedentata extraction process, practical and clinical combination of traditional Chinese and western medicine, in 07 th year 2014) adopt single-factor and star point design to perform experiments, take ethanol volume fraction, solvent ratio and extraction time as independent variables, take total flavone, dihydromyricetin, myricitrin and myricetin yield as dependent variables, perform multivariate linear regression and binomial fitting on all levels, optimize process parameters through an effect surface method, and perform comparative analysis on predicted values and actual values. As a result: the optimal extraction process is determined to be 30 times of 65% ethanol extraction for 1 time, each time for 30 min. And (4) conclusion: the star point design effect surface method can be used for optimizing the extraction process of the ampelopsis grossedentata, the model prediction is good, the extraction conditions are stable, and the experimental design method has higher reliability.

Fructus syringae etc. (fructus syringae etc., extraction and purification of dihydromyricetin in ampelopsis grossedentata, 32 nd 2011) extraction method of dihydromyricetin from ampelopsis grossedentata by water extraction method, and purification and detection of dihydromyricetin are carried out. The extraction conditions of the process are optimized through a single-factor test and an orthogonal test. The results show that the optimal process conditions are as follows: the extraction temperature is 90 ℃, and the material-liquid ratio is 1: 10 (g: ml), the extraction time is 60min, and the yield of the dihydromyricetin is the maximum under the process condition; after 5 times of recrystallization, the purity of the total flavone is improved to 91.0 percent from the original 68.51 percent. The extraction and purification process of the dihydromyricetin is simple, the cost is low, the raw material source is easy, and the dihydromyricetin has good production process prospect as an antioxidant.

The content of flavone is measured by spectrophotometry by Kongqingtong and the like (Kongqingtong and the like, the process research of purifying the Ampelopsis grossedentata flavone by macroporous resin, China national medicine journal, 2013, stage 09), and the optimal condition for purifying the Ampelopsis grossedentata flavone by macroporous resin is screened. The experimental results show that: the adsorption effect of the HPD100 resin is best, when the concentration of flavone is 137.8ug/mL, the volume of an upper column is 5mL, the adsorption is 30min, and the adsorption is carried out by using 95% ethanol at the flow rate of 1.5mL/min, the adsorption rate is 85.44%, the elution rate is 94.92%, the recovery rate is 95.66%, and the mass fraction of the flavone in a sample is purified from 2.76% to 81.1%. Experiments prove that the process is reasonable and feasible and is suitable for industrial production.

Huangrenjie (Huangrenjie et al, research on the process for separating and purifying ampelopsin from Ampelopsis grossedentata by macroporous adsorption resin, traditional Chinese medicine, 2016 (05) period) compares the static adsorption and desorption capacities of 6 different types of macroporous adsorption resin, inspects the dynamic adsorption and elution parameters, and screens the process conditions for separating and purifying ampelopsin by the optimum macroporous adsorption resin. The result shows that the SP700 type macroporous adsorption resin is preferably the optimal type resin, and the diameter-height ratio is determined to be 1: 10, the sample loading concentration is 5mg/mL, the sample loading volume is 4BV, and the sample loading speed is 1 BV/h. Dynamic elution is carried out by water (7BV), 10 percent ethanol (8BV) and 20 percent ethanol (11BV) respectively at the flow rate of 2BV/h, and finally ampelopsin with the mass fraction of 95.5 percent is obtained. The macroporous adsorption resin method is simple and feasible to operate, and the ampelopsin raw material with high quality fraction can be obtained.

Hu Li Zhi and the like (Hu Li Zhi and the like, response surface method optimizes the extraction process of total flavonoids in Ampelopsis grossedentata leaves, grain and oil processing, 2010 year 08) takes Ampelopsis grossedentata leaves as raw materials, ethanol-water as solvent, total flavonoids in the leaves are extracted by heating and refluxing, and optimal extraction process conditions are obtained by response surface test optimization: extracting at 70 deg.C for 60min with ethanol concentration of 58% and liquid-solid ratio of 40 for 1 time. Under the condition, the extraction rate of the total flavonoids can reach 73.93 percent.

The method comprises the steps of respectively processing and treating the vine tea by drying in ovens at different temperatures and naturally airing in different drying methods, and determining the content of a main functional component dihydromyricetin in the vine tea by adopting a reversed-phase high performance liquid chromatography. Octadecylsilane chemically bonded silica is used as a stationary phase, acetonitrile-0.1% phosphoric acid aqueous solution is used as a mobile phase, gradient elution is carried out, and the detection wavelength is 291 nm. The results show that the content of the dihydromyricetin in the vine tea obtained by adopting the oven drying mode is obviously higher than that of the naturally dried vine tea, and the dihydromyricetin content in the vine tea obtained by drying at different temperatures of 60 ℃, 80 and 100 ℃ is slightly different, but the difference is not large; the vine tea collected in different periods has the highest content of dihydromyricetin in the vine tea collected in 5 months. Therefore, the content of dihydromyricetin in the vine tea can be effectively improved by adopting an oven drying mode, but the influence of different temperatures on main active ingredients in the vine tea is small; the optimum harvest time of the vine tea is 5 months per year.

Beam 29709, and the like (beam 29709, the response surface method optimizes the process for extracting ampelosis grossedentata dihydromyricetin from the ampelosis grossedentata through ultrasonic waves, Hubei agricultural science, 2015 02 period), and the process conditions for extracting ampelosis grossedentata dihydromyricetin from the Sanskrit mountain through the response surface analysis method are optimized. The volume fraction of ethanol, the material-liquid ratio and the extraction time are used as influencing factors, on the basis of a single-factor test, a 3-factor 3 horizontal response surface analysis method is adopted, the extraction rate of dihydromyricetin is used as a response value according to a Box-Benhnken central combined test design principle, and the response surface analysis is carried out to optimize the condition of ultrasonic extraction of dihydromyricetin in the wild vine tea of Sanskajan mountain. The result shows that the optimal process conditions for extracting the dihydromyricetin in the vine tea by ultrasonic waves are that the volume fraction of ethanol is 51.00 percent, and the material-liquid ratio is 1: 26.00(g/mL) and 40.00min of ultrasonic time, under the condition, the extraction rate of the dihydromyricetin is 28.41%, the extraction rate of the dihydromyricetin predicted by a regression model is 28.61%, the RSD is 1.16% through verification, the fitting degree is good, and the condition that the response surface method optimizes the process condition for ultrasonically extracting the ampelopsis grossedentata dihydromyricetin is stable and feasible.

Wangwei and the like (Wangwei and the like, the process for extracting ampelopsin from vine tea by Tween-80 ultrasonic waves is optimized by a response surface method, Guangzhou chemical industry, 2016, 16 th) optimize the process for extracting dihydromyricetin from vine tea by the response surface method. On the basis of a single-factor test, selecting Tween-80 concentration, ultrasonic time and ultrasonic temperature as independent variables, and dihydromyricetin yield as a response value, carrying out Box-benzhnken center combined experimental design, and optimizing extraction conditions by using a response surface design method. The optimal extraction conditions were obtained as follows: the feed-liquid ratio is 30mL/g, the concentration of Tween-80 is 6.8%, the ultrasonic temperature is 54 ℃, the ultrasonic time is 29min, the extraction yield of the dihydromyricetin in the ampelopsis grossedentata is 355.8mg/g, the theoretical value is 353.7mg/g, and the RSD is 0.59%. The method for extracting dihydromyricetin Tween-80 from vine tea by using the cooperation of the response surface design method is feasible and has reliable results.

The method is characterized in that the Xiyufeng and the like (Xiyufeng and the like, a response surface analysis method optimizes the extraction process of the dihydromyricetin in the vine tea, China journal of Experimental prescriptions, 2012, stage 17) take the extraction rate of the dihydromyricetin as an investigation index, on the basis of a single-factor test, the volume fraction of ethanol, the feed-liquid ratio and the extraction time are selected as independent variables, the extraction rate of the dihydromyricetin is a response value, and the extraction process conditions of the dihydromyricetin are optimized by adopting a three-factor three-level response surface analysis method. The result shows that the optimal extraction process condition is 17 times of 81 percent ethanol reflux extraction for 95 min. Under the condition, the extraction rate of the dihydromyricetin can reach 9.58 percent, and the difference between the extraction rate and the theoretical value of 9.72 percent is only 0.14 percent. The preferable extraction process of the dihydromyricetin by adopting the response surface method is feasible.

The research on the extraction and purification process of dihydromyricetin in vine tea is carried out by Tunxi Xiu and the like (Tunxi Xiu and the like, the research on the extraction and purification process of dihydromyricetin in vine tea, Jiangxi food industry, 2011 02), and the optimal process parameters are determined through single factor and orthogonal experiments: the extraction temperature is 95 ℃, the extraction time is 120min, and the material-liquid ratio is 1: 25, the granularity of the raw material is 80 meshes, and under the condition, the yield of the dihydromyricetin is 22.8 percent. The crude extract is treated with acetone reflux extraction, concentration and water precipitation to obtain crystals, and the crystals are recrystallized for 4 times to obtain dihydromyricetin product with purity up to 91.3% and yield up to 4.2%.

The method comprises the steps of obtaining dihydromyricetin in the Ampelopsis grossedentata by a hot water extraction method of the unculus nuda and the like (the unculus nuda and the like, the extraction process research of dihydromyricetin in Ampelopsis grossedentata, modern food technology, 2009 08), measuring the content of the dihydromyricetin by liquid chromatography, comparing and researching primary extraction and secondary extraction, and optimizing secondary extraction process conditions by an orthogonal test. The result shows that the optimal conditions for the secondary extraction are as follows: the extraction temperature is 95 ℃, the extraction time is 60min, and the material-liquid ratio is 1: 25, pH 8. Under the condition, the extraction rate of the dihydromyricetin is 30.81%.

Guo Wei et al (Guo Wei et al, the optimization of ampelopsis grossedentata dihydromyricetin extraction process, academic of Hubei university of industry, 2016 (02)) used a response surface analysis method to optimize and research the extraction process of dihydromyricetin in ampelopsis grossedentata. On the basis of a single-factor experiment, the optimal extraction conditions are determined by a Response Surface Method (RSM) as follows: the extraction temperature is 78 deg.C, the extraction time is 64min, and the pH is 8. Under the optimal extraction process condition, the predicted value of the extraction rate of the dihydromyricetin can reach 15.926 percent, the measured value is 15.860 percent, and the relative error is 0.42 percent; the experiments of recrystallization and purification are carried out on the dihydromyricetin, and the purity of the dihydromyricetin reaches 97.8 percent after 5 times of recrystallization.

The Cao Yi et al (Cao Yi et al, research on green extraction and purification method of dihydromyricetin in Ampelopsis grossedentata, food technology, 2011, at 06 days) have studied a novel green extraction and purification method of dihydromyricetin. The results show that: the extraction process conditions are optimized by adopting a hot water extraction method and through single factor analysis and orthogonal experiments. Adopts a purification method of activated carbon decoloration and repeated recrystallization to obtain the dihydromyricetin with the purity of more than 98 percent.

Fructus Myricae Rubrae etc. (fructus Myricae Rubrae etc., microwave extraction process research of extracting dihydromyricetin from Ampelopsis Grossdentata, natural product research and development, 2005 05) use the orthogonal design method, regard water as the solvent, have studied 3 factors of extraction temperature, microwave radiation time and feed-liquid ratio, each factor is 3 levels, choose L9(33) orthogonal design table, measure dihydromyricetin with HPLC, and regard its content as the evaluation index. The results show that: extracting at 95 deg.C for 15min, and mixing the extractive solution with the extractive solution at a ratio of 1: the extraction rate of dihydromyricetin is the highest at 20 days.

A novel process route for extracting polysaccharide and dihydromyricetin from vine tea at low temperature is developed by the research of Wang Hui Bin (Wang Hui Bin, etc., the process research of extracting polysaccharide and dihydromyricetin from vine tea at low temperature, food industry, 2015 08). The extraction process is optimized through single-factor and orthogonal tests, and 4-factor and 3-level orthogonal tests are designed for four main influence factors, namely extraction time, temperature, ultrasonic power and water-material ratio. The optimum extraction process parameters are water-material ratio of 30: 1(mL/g), extraction time of 15min, ultrasonic power of 1000W, and extraction temperature of 50 deg.C by comprehensively considering the analysis results of orthogonal test and product properties. Under the best extraction conditions, the extraction rate of the crude polysaccharide is 6.74 percent, and the yield of the dihydromyricetin is 24.37 percent. The Ampelopsis grossedentata polysaccharide obtained by ultrasonic extraction is an uronic acid polysaccharide, the content of neutral sugar in the crude product is 40.11%, and the content of uronic acid in the crude product is 41.37%. The purity and the extraction rate of the crude product obtained by the ultrasonic-assisted low-temperature extraction technology are high, the properties are good, and the subsequent purification steps of the product can be greatly reduced.

Westan boat and the like (Westan boat and the like, new process research on extraction of ampelopsis grossedentata dihydromyricetin, food science and technology, 2007, 09) take a MARS5 microwave device and a pressure steam sterilizer as extraction devices, dilute alkali water as a solvent and an absorbance method as a determination method. Single-factor experiments and orthogonal experiments are carried out on 6 factors of the material-liquid ratio, the microwave temperature, the microwave time, the microwave power, the rotor speed and the high-temperature high-pressure time, the influence on the extraction rate of the dihydromyricetin is investigated, and through the orthogonal experiments, the optimal extraction condition is determined to be the high-temperature high-pressure time of 45min, the material-liquid ratio is 1: 25, the microwave temperature is 95 ℃, the microwave time is 5min, the microwave power is 600W, and the rotor is high-speed.

In addition, there are some valuable reports on the quality control method of dihydromyricetin. For example, in linshi yao and the like (linshi yao and the like, the content of dihydromyricetin in ampelopsis grossedentata is determined by an HPLC method, the university of Fujian traditional Chinese medicine is reported in 2014, 03), the high performance liquid chromatography is adopted, and the chromatographic column is as follows: dima C18 column (250 mm. times.4.6 mm, 5 μm); mobile phase: methanol-0.05% phosphoric acid solution (35: 65); flow rate: 0.8 mL/min; column temperature: 30 ℃; detection wavelength: 290 nm; sample introduction amount: 5 μ L. As a result, the dihydromyricetin presents a good linear relationship in 1.31-6.55 mug, the sample solution is stable in 24h, and the average sample recovery rate is 96.93%. Conclusion the HPLC method has high precision and good repeatability.

The method for measuring the content of the dihydromyricetin in the wild vine tea by the high performance liquid chromatography is established by Chenshengsheng and the like (Chenshenshensheng and the like, dihydromyricetin in the wild vine tea is extracted by different methods through HPLC measurement, university of Guizhou university (Nature science edition), 05 years of 2013), and the content difference of the dihydromyricetin in the wild vine tea extracted by different methods is compared. The method comprises the following steps: pulverizing wild Ampelopsis Grossdentata, dissolving in methanol solution, ultrasonic treating, and purifying with C18 chromatographic column (4.6mm × 250mm, 5um) with methanol: water: phosphoric acid (25: 75: 0.1) as a mobile phase, a flow rate of 0.7mL/min, a column temperature: measuring the content of dihydromyricetin in Ampelopsis Grossdentata at 25 deg.C under 292nm wavelength with ultraviolet detector. The result shows that the dihydromyricetin has a good linear relation (r is 0.9997) in the mass concentration range of 0.2-1.0 mg/mL, the lowest detection limit is 5ng/mL, the normalized recovery rate is 98.47-99.14% under low, medium and high 3 levels, and the relative standard deviation (RSD%) is 0.28-0.49%. The wild vine tea extracted by the methanol ultrasonic extraction method has higher content of dihydromyricetin and less impurities. The method has the advantages of simple pretreatment operation, high sensitivity and wide application range.

The method is characterized in that the optimum detection conditions are that a chromatographic column is a Nova PakC18 stainless steel column, the detection wavelength is 294nm, and methanol-water (volume ratio 24: 76) is used as a mobile phase, the coefficient of variation of the method is 1.125%, the average recovery rate is 95.03%, and the minimum detection amount is 10ng., and the content of the dihydromyricetin at different parts in the ampelopsis grossedentata in Hunan is 11.87% -40.66%.

Wangchun et al (Wangchun et al, research on determination of dihydromyricetin in health food by HPLC method, China journal of health inspection, 2006, 06) established a detection method of dihydromyricetin in health food. The method comprises measuring content of dihydromyricetin in fructus Ampelopsis Grossdentata health food by reversed phase High Performance Liquid Chromatography (HPLC) with dihydromyricetin as reference substance and dihydromyricetin as the highest content of flavonoids in fructus Ampelopsis Grossdentata. The results showed an average recovery of 100.6% and an RSD of 3.11%. The method is simple, reliable and accurate, and can be used as a method for measuring the flavonoid functional component monomer in the vine tea health food.

In addition, there are many reports in the literature that dihydromyricetin has a wide range of biological activities. For example, Qinli et al reported that AMPK is activated by dihydromyricetin to inhibit vascular endothelial cell apoptosis induced by hyperglycemia (third military report of medical science); maxin et al reported the relationship between dihydromyricetin inhibition of liver lipopexia and mitochondrial fusion gene changes in high-fat-fed mice (third-force report of medical science); zhangyu et al reported the effect of dihydromyricetin in inhibiting hepatic stellate cell activation through TGF-beta 1/Smad signaling pathway (third military report of medical science); lusquare et al reported the effects of dihydromyricetin on proliferation and apoptosis of human lung adenocarcinoma cells and its mechanism (tumor, stage 10 in 2015); experimental study on dihydromyricetin-induced apoptosis of human lung adenocarcinoma cell line AGZY-83-a (chinese pharmacological report, 2008, 05); first, Chinese zodiac phoenix et al reported the research of blood sugar reducing effect of dihydromyricetin on diabetic mice (traditional Chinese medicine pharmacology and clinic, 2016 year 03); the study on the antibacterial activity and DPPH free radical scavenging ability of Ampelopsis grossedentata extract with the same content of dihydromyricetin (science and technology in food industry, stage 05 2015) is reported by Kong Qi et al; baxifene et al reported the effect of dihydromyricetin on hypnosis in pentobarbital sodium mice (Shizhen national medicine, 2008); the study on the anti-fatigue effect of dihydromyricetin (J.Pharmacopeia, 2016, 23) was reported by the Zenglu et al; the Wangkangqi et al reported the anti-inflammatory activity comparison study of dihydroquercetin and dihydromyricetin (Chinese veterinary medicine J, 2016: stage 07); qi et al Panthenar reported the anti-hangover effect of dihydromyricetin (Ministry of agriculture and biology in mountain area, 03, 2012).

The preparation of plant extracts rich in dihydromyricetin with excellent performance is of great significance in the field and is expected by those skilled in the art.

Disclosure of Invention

The present invention is directed to a method for preparing a dihydromyricetin-rich plant extract (which is generally referred to as white tea extract in the art) which is expected to have excellent properties, such as high dihydromyricetin recovery, high dihydromyricetin content, and/or high stability. It has been surprisingly found that the method of the present invention for preparing a dihydromyricetin-rich white tea extract can advantageously achieve the technical expectations of one or more of the above aspects. The present invention has been completed based on this finding.

To this end, the present invention provides in a first aspect a process for preparing a dihydromyricetin-rich white tea extract, comprising the steps of:

(1) providing ampelopsis plant leaves which are dried until the moisture content is lower than 10%, and crushing the ampelopsis plant leaves into coarse powder to obtain ampelopsis plant leaf dry powder;

(2) adding 5-8 times of water into the ampelopsis plant leaf dry powder, soaking for 1-3 hours, then decocting for 30-120 minutes, and filtering to obtain filtrate; adding 3-6 times of water into filter residues, decocting for 30-120 minutes, and filtering to obtain filtrate; mixing the two filtrates;

(3) adding kaolin and propylene glycol into the filtrate, uniformly stirring, standing for 2-4 hours, and concentrating under reduced pressure at 50-70 ℃ to 1/5-1/3 volume; adding ethanol until the ethanol content reaches 60-70%, uniformly stirring, standing for 6-10 hours, and filtering to remove solid matters;

(4) concentrating under reduced pressure at 50-70 deg.C until no alcohol smell exists, and spray drying until water content is less than 5% to obtain white tea extract.

The method according to the first aspect of the present invention, wherein in step (1), the ampelopsis plant is selected from Ampelopsis grossedentata or Ampelopsis megalophylla.

The method according to the first aspect of the present invention, wherein in the step (1), the drying is a drying manner selected from the group consisting of: air drying, sun drying, or heat drying.

The process according to the first aspect of the present invention, wherein in step (1), the drying is to a moisture content of less than 8%.

The method according to the first aspect of the present invention, wherein in the step (2), 5 to 6 times of water is added for the first time to soak.

The method according to the first aspect of the present invention, wherein in the step (2), 5 to 6 times of water is added for soaking for 1 to 2 hours for the first time.

The method according to the first aspect of the present invention, wherein in the step (2), 5 to 6 times of water is added for the first time to soak for 1 to 2 hours, and then the decoction is carried out for 30 to 60 minutes.

The process according to the first aspect of the present invention, wherein in step (2), 0.5 to 2% (v/v) ethyl acetate by volume of water is further added with the first addition of water, for example, 0.5 to 1% (v/v) ethyl acetate by volume of water is further added with the first addition of water.

The method according to the first aspect of the present invention, wherein in the step (2), the residue is decocted with 3 to 4 times of water.

According to the method of the first aspect of the invention, in the step (2), the filter residue is added with 3-4 times of water and decocted for 30-60 minutes.

The process according to the first aspect of the present invention, wherein in the step (2), ethyl acetate is further added in an amount of 0.25 to 1% (v/v) by volume of water with the second addition of water to the residue, for example, ethyl acetate is further added in an amount of 0.25 to 0.5% (v/v) by volume of water with the second addition of water to the residue. It has been surprisingly found that the stability of dihydromyricetin of the target substance in the final extract can be significantly improved when a small amount of acetic acid is added to the extraction solvent, and the technical effect of the present invention to improve the stability of the target substance cannot be explained by conventional theories since such ethyl acetate is actually removed through subsequent processes.

The method according to the first aspect of the present invention, wherein in the step (3), the amount of the kaolin is 1 to 2% (g/100ml) based on the amount of the filtrate.

The method according to the first aspect of the present invention, wherein in the step (3), the amount of the kaolin is 1 to 1.5% (g/100ml) based on the amount of the filtrate.

The process according to the first aspect of the present invention, wherein in the step (3), the propylene glycol is 1, 2-propylene glycol.

The process according to the first aspect of the present invention, wherein in the step (3), the amount of propylene glycol is 0.2 to 0.6% (g/100ml) based on the amount of the filtrate.

The process according to the first aspect of the present invention, wherein in the step (3), the amount of propylene glycol is 0.2 to 0.4% (g/100ml) based on the amount of the filtrate.

According to the method of the first aspect of the present invention, in the step (3), kaolin and propylene glycol are added to the filtrate, the mixture is uniformly stirred, and the mixture is allowed to stand for 2 to 3 hours.

According to the method of the first aspect of the invention, in the step (3), kaolin and propylene glycol are added into the filtrate, the mixture is uniformly stirred, kept stand for 2-3 hours, and concentrated under reduced pressure at 50-60 ℃.

According to the method of the first aspect of the invention, in the step (3), kaolin and propylene glycol are added into the filtrate, the mixture is uniformly stirred, the mixture is kept stand for 2-3 hours, and the mixture is concentrated under reduced pressure at 50-60 ℃ to 1/5-1/4 volume. It has been surprisingly found that the addition of kaolin and propylene glycol in step (3) of the present invention advantageously increases the recovery of the target chemical and its concentration in the final extract, i.e., achieves a very high level of enrichment.

The method according to the first aspect of the present invention, wherein in the step (3), ethanol is added until the alcohol content reaches 60 to 65%.

The method according to the first aspect of the present invention, wherein in the step (3), ethanol is added until the ethanol content reaches 60 to 65%, and the mixture is stirred uniformly, left for 7 to 9 hours, and filtered to remove solids.

The method according to the first aspect of the present invention, wherein in the step (4), the concentration is carried out at 55 to 65 ℃ under reduced pressure until no alcohol smell is produced.

According to the first aspect of the invention, in the step (4), the white tea extract is obtained by concentrating under reduced pressure at 55-65 ℃ until no alcohol smell is produced, and then performing spray drying until the moisture content is less than 4%.

According to the method of the first aspect of the present invention, the white tea extract obtained by the method comprises dihydromyricetin.

According to the method of the first aspect of the invention, the total recovery rate of dihydromyricetin in the white tea extract is more than 70%. The term "recovery rate" refers to the percentage of dihydromyricetin in the white tea extract prepared by the method of the present invention to the amount of dihydromyricetin in the dried powder of the leaves of the ampelopsis plant used for preparing the extract, which reflects the recovery rate of dihydromyricetin from the dried powder to the extract of the present invention through the method of the present invention, and the higher the recovery rate indicates the higher the efficiency of the method of the present invention for extracting the dihydromyricetin.

According to the method of the first aspect of the invention, the yield of dihydromyricetin in the white tea extract is more than 80%; for example, the recovery rate can reach 80-90%.

According to the method of the first aspect of the invention, the dihydromyricetin in the white tea extract accounts for 60-90% of the total weight of the extract.

According to the method of the first aspect of the invention, the dihydromyricetin in the white tea extract accounts for 65-85% of the total weight of the extract.

Further, the second aspect of the present invention provides a white tea extract, which comprises dihydromyricetin in an amount of 60-90% of the total weight of the extract.

The white tea extract according to the second aspect of the present invention is present in an amount of 65 to 85% by weight based on the total weight of the extract.

A white tea extract according to a second aspect of the present invention is prepared by a process comprising the steps of:

The white tea extract according to the second aspect of the present invention, wherein in the step (1), the ampelopsis plant is selected from Ampelopsis grossedentata or Ampelopsis megalophylla.

The white tea extract according to the second aspect of the present invention, wherein in the step (1), the drying is a drying manner selected from the group consisting of: air drying, sun drying, or heat drying.

The white tea extract according to the second aspect of the present invention, wherein in the step (1), the drying is drying to a moisture content of less than 8%.

The white tea extract according to the second aspect of the present invention, wherein in the step (2), 5 to 6 times of water is added for the first time to soak.

The white tea extract according to the second aspect of the present invention, wherein in the step (2), 5 to 6 times of water is added for the first time to soak for 1 to 2 hours.

The white tea extract according to the second aspect of the present invention, wherein in the step (2), 5 to 6 times of water is added for the first time to soak for 1 to 2 hours, followed by decoction for 30 to 60 minutes.

The white tea extract according to the second aspect of the present invention, wherein in the step (2), 0.5 to 2% (v/v) ethyl acetate by volume of water is further added with the first water addition, for example, 0.5 to 1% (v/v) ethyl acetate by volume of water is further added with the first water addition.

The white tea extract according to the second aspect of the present invention, wherein in the step (2), the residue is decocted with 3 to 4 times of water.

The white tea extract according to the second aspect of the present invention, wherein in the step (2), the residue is added with 3-4 times of water and decocted for 30-60 minutes.

The white tea extract according to the second aspect of the present invention, wherein in the step (2), ethyl acetate is further added in an amount of 0.25 to 1% (v/v) by volume of water with the second addition of water to the residue, for example, ethyl acetate is further added in an amount of 0.25 to 0.5% (v/v) by volume of water with the second addition of water to the residue.

The white tea extract according to the second aspect of the present invention, wherein in the step (3), the amount of the kaolin is 1 to 2% (g/100ml) of the amount of the filtrate.

The white tea extract according to the second aspect of the present invention, wherein in the step (3), the amount of the kaolin is 1 to 1.5% (g/100ml) of the amount of the filtrate.

The white tea extract according to the second aspect of the present invention, wherein in the step (3), the propylene glycol is 1, 2-propylene glycol.

The white tea extract according to the second aspect of the present invention, wherein in the step (3), the amount of propylene glycol is 0.2 to 0.6% (g/100ml) of the amount of filtrate.

The white tea extract according to the second aspect of the present invention, wherein in the step (3), the amount of propylene glycol is 0.2 to 0.4% (g/100ml) of the amount of filtrate.

According to the white tea extract of the second aspect of the present invention, in the step (3), kaolin and propylene glycol are added to the filtrate, and the mixture is stirred uniformly and allowed to stand for 2 to 3 hours.

According to the white tea extract of the second aspect of the present invention, in the step (3), kaolin and propylene glycol are added to the filtrate, and the mixture is uniformly stirred, allowed to stand for 2 to 3 hours, and concentrated under reduced pressure at 50 to 60 ℃.

According to the white tea extract of the second aspect of the present invention, in the step (3), kaolin and propylene glycol are added to the filtrate, the mixture is uniformly stirred, the mixture is allowed to stand for 2 to 3 hours, and the mixture is concentrated under reduced pressure at 50 to 60 ℃ until the volume is 1/5 to 1/4. It has been surprisingly found that the addition of kaolin and propylene glycol in step (3) of the present invention advantageously increases the recovery of the target chemical and its concentration in the final extract, i.e., achieves a very high level of enrichment.

The white tea extract according to the second aspect of the present invention, wherein in the step (3), ethanol is added until the alcohol content reaches 60 to 65%.

According to the second aspect of the invention, in the step (3), ethanol is added until the ethanol content reaches 60-65%, the mixture is uniformly stirred, kept stand for 7-9 hours, and filtered to remove solids.

The white tea extract according to the second aspect of the present invention, wherein in the step (4), the concentration is performed at 55 to 65 ℃ under reduced pressure until no alcoholic smell is produced.

The white tea extract according to the second aspect of the present invention, wherein in the step (4), the white tea extract is obtained by concentrating under reduced pressure at 55 to 65 ℃ until no alcohol smell is produced, and then spray-drying until the moisture content is less than 4%.

The white tea extract according to the second aspect of the present invention comprises dihydromyricetin.

The white tea extract according to the second aspect of the present invention, wherein the total recovery rate of dihydromyricetin is more than 70%.

The white tea extract according to the second aspect of the present invention, wherein the yield of dihydromyricetin is more than 80%; for example, the recovery rate can reach 80-90%.

Further, the third aspect of the present invention provides a composition comprising an extract of white tea, together with physiologically acceptable excipients.

The composition according to the third aspect of the present invention, wherein the adjuvant is selected from the group consisting of: diluents such as water, sucrose, starch, dextrin, lactose, etc., flavoring agents such as aspartame, saccharin sodium, acesulfame potassium.

The composition according to the third aspect of the present invention is in the form of a formulation of a tablet, a granule, an oral solution. These forms of preparation can be prepared from the white tea extract obtained in the present invention by methods well known to those skilled in the art. In preparing these preparation forms, the physiologically acceptable auxiliary materials may be added thereto according to a method well known in the art.

The composition according to the third aspect of the present invention, wherein the white tea extract is prepared by a method comprising the steps of:

The composition according to the third aspect of the present invention, wherein in step (1), the ampelopsis plant is selected from Ampelopsis grossedentata or Ampelopsis megalophylla.

The composition according to the third aspect of the present invention, wherein in the step (1), the drying is a drying manner selected from the group consisting of: air drying, sun drying, or heat drying.

The composition according to the third aspect of the present invention, wherein in the step (1), the drying is drying to a moisture content of less than 8%.

The composition according to the third aspect of the present invention, wherein in the step (2), 5 to 6 times of water is added for the first time to soak.

The composition according to the third aspect of the present invention, wherein in the step (2), 5 to 6 times of water is added for soaking for 1 to 2 hours for the first time.

The composition according to the third aspect of the present invention, wherein in the step (2), 5 to 6 times of water is added for the first time to soak for 1 to 2 hours, and then the decoction is carried out for 30 to 60 minutes.

The composition according to the third aspect of the present invention, wherein in the step (2), 0.5 to 2% (v/v) by volume of water of ethyl acetate is further added with the first water addition, for example, 0.5 to 1% (v/v) by volume of water of ethyl acetate is further added with the first water addition.

The composition of the third aspect of the present invention, wherein in the step (2), the residue is decocted with 3 to 4 times of water.

The composition of the third aspect of the present invention, wherein in the step (2), the residue is added with 3-4 times of water and decocted for 30-60 minutes.

The composition according to the third aspect of the present invention, wherein in the step (2), ethyl acetate is further added in an amount of 0.25 to 1% (v/v) by volume of water with the second addition of water to the residue, for example, ethyl acetate is further added in an amount of 0.25 to 0.5% (v/v) by volume of water with the second addition of water to the residue.

The composition according to the third aspect of the present invention, wherein in the step (3), the amount of the kaolin is 1 to 2% (g/100ml) based on the amount of the filtrate.

The composition according to the third aspect of the present invention, wherein in the step (3), the amount of the kaolin is 1 to 1.5% (g/100ml) based on the amount of the filtrate.

The composition according to the third aspect of the present invention, wherein in the step (3), the propylene glycol is 1, 2-propylene glycol.

The composition according to the third aspect of the present invention, wherein in the step (3), the amount of propylene glycol is 0.2 to 0.6% (g/100ml) based on the amount of the filtrate.

The composition according to the third aspect of the present invention, wherein in the step (3), the amount of propylene glycol is 0.2 to 0.4% (g/100ml) based on the amount of the filtrate.

According to the composition of the third aspect of the present invention, in the step (3), kaolin and propylene glycol are added to the filtrate, the mixture is uniformly stirred, and the mixture is allowed to stand for 2 to 3 hours.

According to the third aspect of the invention, in the step (3), kaolin and propylene glycol are added into the filtrate, the mixture is uniformly stirred, the mixture is kept stand for 2 to 3 hours, and the mixture is concentrated under reduced pressure at 50 to 60 ℃.

According to the third aspect of the invention, in the step (3), kaolin and propylene glycol are added into the filtrate, the mixture is uniformly stirred, the mixture is kept stand for 2-3 hours, and the mixture is concentrated under reduced pressure at 50-60 ℃ to 1/5-1/4 volume. It has been surprisingly found that the addition of kaolin and propylene glycol in step (3) of the present invention advantageously increases the recovery of the target chemical and its concentration in the final extract, i.e., achieves a very high level of enrichment.

The composition according to the third aspect of the present invention, wherein in the step (3), ethanol is added to an alcohol content of 60 to 65%.

The composition according to the third aspect of the present invention, wherein in the step (3), ethanol is added until the ethanol content reaches 60 to 65%, and the mixture is stirred uniformly, kept stand for 7 to 9 hours, and filtered to remove solids.

The composition of the third aspect of the present invention, wherein in the step (4), the mixture is concentrated under reduced pressure at 55 to 65 ℃ until no alcohol smell is produced.

The composition of the third aspect of the present invention, wherein in the step (4), the white tea extract is obtained by concentrating at 55-65 ℃ under reduced pressure until no alcohol smell is produced, and then spray-drying until the moisture content is less than 4%.

According to the composition of the third aspect of the present invention, the white tea extract contains dihydromyricetin.

According to the composition of the third aspect of the present invention, the total recovery rate of dihydromyricetin in the white tea extract is more than 70%.

Further, in a fourth aspect, the present invention provides a use of the white tea extract according to any one of the embodiments of the first aspect of the present invention or the white tea extract according to any one of the embodiments of the second aspect of the present invention in preparing a product for scavenging free radicals, resisting oxidation, resisting thrombus, resisting tumor, resisting bacteria, diminishing inflammation, relieving alcoholism and alleviating hangover, preventing alcoholic liver and fatty liver, inhibiting liver cell degeneration, reducing incidence of liver cancer, resisting hypertension, inhibiting in vitro platelet aggregation and in vivo thrombus formation, reducing blood lipid and blood glucose levels, increasing SOD activity, protecting liver, activating AMPK, inhibiting hyperglycemia-induced vascular endothelial cell apoptosis, inhibiting liver fat accumulation, inhibiting liver stellate cell activation, inhibiting lung adenocarcinoma cell proliferation, hypnotizing, and/or resisting fatigue.

In the above-described steps of the preparation method of the present invention, although the specific steps described therein are distinguished in some detail or in language description from the steps described in the preparation examples of the detailed embodiments below, those skilled in the art can fully summarize the above-described method steps in light of the detailed disclosure throughout the present disclosure.

Any embodiment of any aspect of the invention may be combined with other embodiments, as long as they do not contradict. Furthermore, in any embodiment of any aspect of the invention, any feature may be applicable to that feature in other embodiments, so long as they do not contradict. The invention is further described below.

All documents cited herein are incorporated by reference in their entirety and to the extent such documents do not conform to the meaning of the present invention, the present invention shall control. Further, the various terms and phrases used herein have the ordinary meaning as is known to those skilled in the art, and even though such terms and phrases are intended to be described or explained in greater detail herein, reference is made to the term and phrase as being inconsistent with the known meaning and meaning as is accorded to such meaning throughout this disclosure.

It has been found that the extracts of the present invention have excellent biological activities including, but not limited to: scavenging free radicals, resisting oxidation, resisting thrombosis, resisting tumor, resisting bacteria, diminishing inflammation, relieving alcoholism and relieving alcoholism, preventing alcoholic liver and fatty liver, inhibiting hepatocyte deterioration, reducing incidence of liver cancer, resisting hypertension, inhibiting in vitro platelet aggregation and in vivo thrombosis, reducing blood lipid and blood sugar levels, increasing SOD activity, protecting liver, activating AMPK, inhibiting hyperglycemia-induced vascular endothelial cell apoptosis, inhibiting liver lipopexia, inhibiting hepatic stellate cell activation, inhibiting lung adenocarcinoma cell proliferation, hypnotizing, and/or resisting fatigue, etc. In addition, the white tea extract obtained by the specific preparation process has excellent chemical characteristics, such as extremely high content of some typical active chemical substance components in the extract or the composition; also for example, some typical active chemical components have extremely high stability in the extract or composition of the present invention. In particular, it has been unexpectedly found that the addition of small amounts of kaolin in combination with propylene glycol during the concentration process to produce the extract of the present invention significantly enriches the typical active chemicals described above in the composition of the present invention, since kaolin is itself a conventional pharmaceutical excipient and is insoluble in water and ethanol, it can be removed by simple filtration means during the process of the present invention; propylene glycol, however, is an extremely safe and commonly used pharmaceutical drug-resistant material because of its small addition amount, even if it remains in the extract of the present invention, and such a small amount of residue does not cause any adverse effect at all on the body. For example, in a first supplemental experiment, referring to the methods of examples 1-5, respectively, except that no kaolin was added in step (3), the five extracts obtained had a yield of dihydromyricetin of 43-57% and an amount of dihydromyricetin of 32-41% of the total weight of the extract (e.g., the extract obtained in accordance with example 1, which may be referred to herein as B11, having two percentages of 48.1% and 36.4%, respectively); in a second supplementary experiment, with reference to the process of examples 1-5, respectively, except that no propylene glycol was added in step (3), the five extracts obtained had a yield of 37-52% dihydromyricetin and an amount of dihydromyricetin of 30-39% of the total weight of the extract (for example, the extract obtained in reference to example 1, which can be identified as B21 in the present invention, having two percentages of 42.2% and 35.8%, respectively); in a third supplemental experiment, referring to the methods of examples 1-5, respectively, except that neither kaolin nor propylene glycol was added in step (3), five batches of the extract were obtained with 41-49% recovery of dihydromyricetin, and 35-43% dihydromyricetin by total weight of the extract (e.g., the extract obtained from example 1, which may be labeled as B31 in the present invention, had two percentages of 46.1% and 38.8%, respectively). In addition, it has been found that, particularly unexpectedly, the addition of a trace amount of ethyl acetate to the extraction solvent during the extraction process of the present invention helps to improve the stability of dihydromyricetin in the extract; for example, in a further supplementary test, reference is made to the process of examples 1 to 5, respectively, except that in step (2), ethyl acetate is not added in both extractions, and that in the five extracts obtained, the recovery of dihydromyricetin is 84 to 87%, the amount of dihydromyricetin is 72 to 76% of the total weight of the extract, and the residual content of dihydromyricetin is 83 to 87% in the stability test for 40 to 5 months (for example, the extract obtained in reference to example 1, which can be identified as B41 in the present invention, has the above three percentages of 85.3%, 74.2% and 85.2%, respectively).

Ampelopsis grossedentata (Hand-Mazz) W.T.wang), is a Ampelopsis genus of Vitaceae family, is a woody vine, and is widely distributed in places such as Guangdong, Guangxi, Hunan, Hubei, Yunnan, Guizhou, Jiangxi, Fujian, etc. Ampelopsis grossedentata medicinal materials are collected in the Chinese medicinal material standard (2009 edition) of Hunan province. The small branches of the ampelopsis grossedentata are cylindrical, have obvious longitudinal ribs and are hairless. Tendrils branch 2, separated by 2 internodes and leaf pairs. The leaves are 1-2 pinnate compound leaves, one pair of the base parts of the 2 pinnate compound leaves is 3 small leaves, the small leaves are oval, oval or oblong, 2-5 cm long and 1-2.5 cm wide, the top ends are sharp or tapered, the base parts are wide wedge-shaped or nearly circular, 2-5 sawteeth are arranged on each side of the edge, the upper parts are green, the lower parts are light green, and both sides are unhaired; 3-5 pairs of lateral veins, the net veins are slightly prominent, and the net veins at the last stage are not obvious; no hair is left; leaf-supporting falls early. The inflorescence is an umbrella-house-shaped multi-branch cymbidium inflorescence, and is opposite to leaves; the inflorescence peduncle is 1.5-3.5 cm long and has no hair; the flower stalk is 1.5-2 mm long and has no hair; the flower buds are oval, the height is 1.5-2 mm, the top ends are round, and no hair exists; the calyx is disc-shaped, the edge is wavy and has shallow cleft, and no hair exists; petal 5, oval, height 1.2-1.7 mm, hairless, stamen 5, anther oval, length slightly more than wide, flower disc developed, wave-shaped shallow cleft; the lower part of the ovary is combined with the floral disc, the style of the floral pillar is drill, and the column cap is not obviously enlarged. The fruits are nearly spherical, the diameter is 0.6-1 cm, and 2-4 seeds are arranged; the seed is inverted oval, the top end is round, the base is provided with a short beak, the hilum is elliptical in the middle of the back of the seed, the ridge at the upper part is protruded, the surface is provided with a blunt rib protrusion, the ridge in the abdomen is protruded, the concave holes at the two sides are inverted oval, and the seed is nearly in the middle from the base. The ampelopsis grossedentata has sweet and light taste and cool property, and has the effects of clearing away heat and toxic materials, dispelling wind-damp, strengthening muscles and bones, diminishing inflammation, relieving pain and the like. The young stem and leaf of the tea are made into health-care tea in folk, and the health-care tea is used for treating symptoms such as cold, fever, swollen sore throat, icteric hepatitis, herpes and furuncle and the like for hundreds of years and is a typical plant used as both medicine and food. The ampelopsis grossedentata contains flavonoid as main active ingredient and has the highest content of dihydromyricetin. Research shows that the total flavone content in the ampelopsis grossedentata is 7.5-8.3% (mass fraction), the dihydromyricetin content is as high as 37.4-40%, and the contents of crude protein, water-soluble protein, amino acid components, total ash, inorganic nutrient elements, polyphenol and water extract are rich. In addition, the product contains 17 amino acids (which cannot be naturally synthesized by human body) such as leucine, iso-amino acid, methionine and the like which are necessary for human body, and 14 trace elements such as potassium, calcium, iron, zinc, magnesium and the like, and the content of the trace elements is related to factors such as local geography, climate and environment and the like. The Chinese medicinal tea is definitely recorded in pharmacopoeias such as Suoyao Bencao and national Chinese herbal medicine compilation, the ampelopsis grossedentata is green and turns into white frost, the drinking effect has obvious health care and treatment effects, and the Chinese medicinal tea is historically named as white tea and Shencha. The overall efficacy of Ampelopsis grossedentata is incomparable with any tea. Ordinary tea can not be drunk at night and is easy to rancid, and the active flavone of ampelopsis grossedentata can kill bacteria and can be drunk after soaking for one week. The Chinese and western medicines can not be taken together with common tea, the tea can release the drug property, and the ampelopsis grossedentata can not release the drug property when taken together with the ampelopsis grossedentata, and can assist the Chinese and western medicines to exert better effect. The Ampelopsis grossedentata contains 18 amino acids necessary for human body, 22 trace elements and higher content of functional component flavonoid compound more than or equal to 6%, has the function of improving the immunity of human body, and is especially suitable for people with weak constitution and low immunity. The identification is carried out by a plurality of national authorities: the vine tea has unique effect, wide application, no toxic or side effect, is suitable for both the old and the young, and can comprehensively enhance the human body resistance, eliminate diseases, build the body and prolong the life after being drunk for a long time.

Ampelopsis grossedentata (Ampelopsis megalophylla Diels et Gilg, also commonly known as Ampelopsis grossedentata) is a genus of Ampelopsis in Vitaceae, and is mainly distributed in Gansu, Shanxi, Hubei, Sichuan, Guizhou, Yunnan, Jiangxi and Chongqing. The Ampelopsis grossedentata is a woody vine. The small branches are cylindrical and have no hair. Tendrils were 3 branches, separated by 2 nodes of discontinuity and leaf pairs. The leaves are two-time feathery compound leaves, a pair of small leaves at the base part are usually 3 small leaves or are diluted into feathery compound leaves, the small leaves are oblong or oval, the length is 4-12 cm, the width is 2-6 cm, the top end is tapered, the base part is heart-shaped, round or nearly truncated, each side of the edge is provided with 3-15 coarse sawteeth, the upper part is green, the lower part is pink green, and both sides are unhaired; 4-7 pairs of lateral veins with slightly prominent reticular veins; the petiole is 3-8 cm long and hairless, the apical leaflet petiole is 1-3 cm long, the lateral leaflet petiole is 0-1 cm long and hairless. The inflorescence is an umbrella-shaped multi-manifold cymbidium inflorescence or a compound two-manifold cymbidium inflorescence, and is grown at the top or opposite to leaves; the inflorescence peduncle is 3.5-6 cm long and has no hair; the flower stalk is 2-3 mm long, the top end is thicker and has no hair; the flower bud is approximately spherical, the height is 1-1.5 mm, and the top end is round; the edge of the disk-shaped calyx is wavy and shallow or the lobe is triangular and has no hair; petal 5, oval, height 0.7-1.2 mm, hairless; stamen 5, the anther is oval, slightly longer than wide; the flower disc is developed and the wavy shape is shallow; the lower part of the ovary is combined with the floral disc, the style of the floral pillar is drill, and the column cap is not obviously enlarged. The fruit is slightly inverted oval, the diameter is 0.6-1 cm, and 1-4 seeds are contained; the seeds are inverted oval, the top end is round, the beak at the base is sharp, the hilum is elliptical in the middle of the back of the seed, the ridge at the upper part is protruded, the ridge at the middle part of the abdomen is protruded, the concave holes at the two sides are ditch-shaped, and the seed reaches the upper part 1/3 of the seed from the base of the seed. The flowering period is 6-8 months, and the fruit period is 7-10 months.

Dihydromyricetin (Dihydromyricetin, molecular formula C15H12O8, CAS number 27200-12-0, molecular weight 320.25, chemical name: (2R, 3R) -3,5, 7-trihydroxy-2- (3,4, 5-trihydroxyphenyl) chroman-4-one), a woody vine plant extracted from Ampelopsis of Vitaceae (such as Ampelopsis grossedentata and Ampelopsis grossedentata), and Hovenia dulcis, wherein the main active ingredient is flavonoid compound, and the flavonoid compound has multiple peculiar effects of scavenging free radicals, resisting oxidation, resisting thrombosis, resisting tumor, diminishing inflammation, etc.; the dihydromyricetin is a special flavonoid compound, and has the general characteristics of the flavonoid compound, and also has the effects of relieving alcoholism, preventing alcoholic liver and fatty liver, inhibiting hepatocyte deterioration, reducing incidence of liver cancer and the like. Is a good product for protecting liver, dispelling the effects of alcohol and sobering up.

The leaves of plants of genus Ampelopsis such as Ampelopsis grossedentata and Ampelopsis megalophylla (which may also be commonly referred to as white tea in the art) and their extracts, especially the typical flavonoid dihydromyricetin in the extracts, have excellent physiological functions. For example, they have the following physiological functions beneficial to the human body:

1. reducing blood lipid. The ampelopsis plant leaves and the effective component dihydromyricetin thereof have the effects of resisting oxygen free radicals, inhibiting the formation of thrombus in vivo and having unique effect of reducing blood fat. The total flavonoids have effects of reducing blood lipid, resisting atherosclerosis and inhibiting fatty liver formation. Has obvious effect on the clinical treatment of hypertension and coronary heart disease.

2. Regulating blood sugar. The ampelopsis plant leaves have high Zn content, the lack of Zn can cause growth retardation, anemia, diabetes, chronic gastritis and the like of a human body, and the Zn also has the function of inhibiting the lipid peroxidation process, so the ampelopsis plant leaves have the anti-aging effect, and a plurality of important enzymes contain the Zn.

3. Protecting liver. The ampelopsis plant leaves contain abundant flavonoid dihydromyricetin, and have obvious liver protection effect and can inhibit the formation of fatty liver. Has liver protecting effect. Researches show that myricetin in the ampelopsis brevipedunculata can obviously reduce ALT, AST activity and T-BIL content in serum of mice acute liver injury model caused by carbon tetrachloride, D-galactosamine and naphthyl isothiocyanate, and relieve degeneration and necrosis of liver tissues, thereby achieving the effects of protecting liver, reducing enzyme and eliminating jaundice. The method adopts canavalin A (ConA) induction to establish a mouse liver injury model, discusses the influence of the ampelopsis grossedentata root on the Fas antigen expression of liver tissues of the ConA-induced mouse liver injury model, finds that the ampelopsis grossedentata root extract can relieve liver pathological changes and reduce the Fas antigen expression of liver cells, has no significant difference compared with a dexamethasone group, and prompts that the ampelopsis grossedentata root can block the Fas antigen expression of the liver cells, so that the killing of CTL to the liver cells and the apoptosis of the ConA-induced liver cells are blocked, and the ampelopsis grossedentata root is one of mechanisms which can play a role in treating liver injury.

4. Can be used for promoting digestion and absorption. The ampelopsis plant leaves have high nutritional value, can supplement unbalanced nutritional ingredients of a human body after being drunk for a long time, maintain normal physiological metabolism, and have positive significance for human health care. The total flavonoids of Ampelopsis plant leaves, especially dihydromyricetin therein, can improve pepsin activity and promote small intestine movement.

5. Improving immunity. This is one of the most prominent effects of leaves of plants of the genus ampelopsis. Through moistening lung, removing liver-toxin, clearing heart fire, invigorating spleen and reinforcing kidney, the medicine can eliminate blood toxin, improve blood quality, restore normal physiological function of five viscera and enhance immunity

6. And (4) resisting aging. VE has a wide range of physiological effects in improving human body vitality and has an anti-aging effect. The VE content in the leaves of Ampelopsis plant is higher than 0.5mg/100g, and VE has effects of protecting in vivo cells from free radical damage, preventing aging, resisting cancer, inhibiting atherosclerosis, and balancing lipid metabolism.

7. Preventing cardiovascular and cerebrovascular diseases. The ampelopsis plant leaves and typical flavonoid compounds of dihydromyricetin have oxygen free radical resisting effect, can inhibit in vivo thrombosis, and has unique effect in lowering blood pressure. Dihydromyricetin can obviously antagonize contraction reaction of thoracic aortic strip of rabbit caused by norepinephrine, and has low toxicity. The ampelopsis plant leaf extract and the flavonoid compounds in the ampelopsis plant leaf extract are compounds with important biological activities of diminishing inflammation, inhibiting abnormal capillary vessels, eliminating free radicals, resisting tumors and the like. The protein, flavonoid and VE are rich in Ca, K and Zn, and the K/Na ratio is moderate, thus being beneficial to the treatment and health care of the cardiovascular system. Flavonoids contain a large amount of therapeutic ingredients, have the characteristic of vitamin P, and protect blood vessels from injury by reducing vascular permeability and fragility, which is associated with the anti-softening function of Ampelopsis grossedentata, because vascular injury is caused by oxidative damage to cells. Therefore, the health-care tea has good health-care effect on patients with hyperlipidemia, hypertension and the like.

8. Expelling toxin. Ampelopsis plant leaves are folk traditional medicines, are recorded as early as famous medical records, and are widely used for diminishing inflammation and detoxifying, and treating osteomyelitis, acute lymphadenitis, acute mastitis, impetigo, eczema, erysipelas furuncle, halophilic bacteria food poisoning and the like. And can be used for treating nausea, emesis, diarrhea, and diuresis; preventing the change of partial fibers in the lung into cirrhosis, and has the effective rate of over 90 percent when being used for treating purulent skin diseases.

9. Has antibacterial effect. The ampelopsis plant leaf extract has different degrees of inhibition effects on staphylococcus aureus, bacillus subtilis, aspergillus niger, aspergillus flavus, penicillium and streptomyces alternatus, the minimum inhibition concentrations of the aspergillus niger and the aspergillus flavus are respectively 0.7 percent and 1.1 percent, and the minimum inhibition concentrations of the staphylococcus aureus and the bacillus subtilis are respectively less than 0.07 percent. Further research shows that the flavonoids compounds in the leaves of the ampelopsis plant have obvious inhibiting effect on staphylococcus aureus, streptococcus A, pseudomonas aeruginosa and escherichia coli and are one of the main effective components. The bacteriostatic experiments of the ampelopsis plant leaves show that the ampelopsis plant leaves have better inhibitory action on staphylococcus aureus, staphylococcus albus, streptococcus B, neisseria, escherichia coli, shigella flexneri, typhoid bacillus and pseudomonas aeruginosa, and the ampelopsis plant leaves are clinically used for treating surgical pyocutaneous disease, osteomyelitis caused by staphylococcus infection and the like, and the curative effect is definite.

10. Anti-inflammatory and analgesic effects. The ampelopsis plant leaf and its typical flavonoid such as dihydromyricetin have inhibitory effect on exudation process of acute and subacute inflammation. It also has inhibitory effect on chronic proliferative inflammation, and has analgesic effect.

11. Has antitumor effect. According to the results of in vitro cytotoxicity inhibition experiments, the ampelopsis plant leaves and typical flavonoids compounds thereof such as dihydromyricetin have strong inhibition effects on human breast cancer MCF-7 cells, nasopharyngeal carcinoma HK-1 cells, human liver cancer Be1-7402 cells and leukemia HL-60 and K562 cells, and the ampelopsis plant leaves and typical flavonoids compounds thereof such as dihydromyricetin are suggested to Be broad-spectrum anticancer drugs.

12. And other functions. The ampelopsis plant leaves and typical flavonoid compounds thereof such as dihydromyricetin have the effects of eliminating phlegm and relieving cough and have obvious sweating effect besides the above effects. It can be used for treating respiratory tract infection and heatstroke. The ampelopsis plant leaves can also obviously relieve drunkenness reaction and shorten sobering-up time. It has also been shown that leaves of Ampelopsis plant and typical flavonoids such as dihydromyricetin have platelet aggregation inhibiting and thrombosis inhibiting effects. Meanwhile, the beverage has higher nutritional value, can supplement unbalanced nutritional ingredients of human bodies and maintain normal physiological metabolism after being drunk for a long time, and has positive significance for human health care.

The white tea extract obtained by extracting the leaves of the ampelopsis plant by the method of the invention is optionally further prepared into compositions such as compositions in the form of preparations, and the extracts or the compositions have excellent chemical properties or biological properties.

Detailed Description

The present invention will be further described by the following examples, however, the scope of the present invention is not limited to the following examples. It will be understood by those skilled in the art that various changes and modifications may be made to the invention without departing from the spirit and scope of the invention. The present invention has been described generally and/or specifically with respect to materials used in testing and testing methods. Although many materials and methods of operation are known in the art for the purpose of carrying out the invention, the invention is nevertheless described herein in as detail as possible.

Test example 1: method for determining dihydromyricetin in ampelopsis plant leaf dry powder or extract thereof

The extract or the ampelopsis plant leaf dry powder of the invention is judged by referring to literature methods of chenshengshen and the like (chenshenshensheng and the like, extracting dihydromyricetin in wild ampelopsis grossedentata by different methods through HPLC (high performance liquid chromatography), college university of Guizhou (Nature science edition), and 05 years of 2013). The chromatographic conditions are as follows: c18 column (4.6mm × 250mm, 5um), purified with methanol: water: phosphoric acid (25: 75: 0.1) as a mobile phase, a flow rate of 0.7mL/min, a column temperature: at 25 ℃ and with an ultraviolet detector at 292 nm.

Test example 2: stability test of white tea extract

The test method comprises the following steps: taking a white tea extract sample, subpackaging by using glass bottles, sealing, placing in an oven at 40 ℃ for 5 months, determining the content of dihydromyricetin in the sample before (0 month) and after (5 months) the treatment of 40-5 months, and taking the percentage obtained by dividing the content of 5 months by the content of 0 month and multiplying by 100% as the residual content of dihydromyricetin after the treatment of 40-5 months. The residual content of the five samples of examples 1-5 of the present invention was determined to be in the range of 97-99%, for example, the residual content of the extract of example 1 was 98.2%.

In addition, the present inventors prepared the white tea extract with reference to the prior art methods that have been searched for, and measured the residual content of dihydromyricetin thereof according to the stability method of the present invention, and as a result, showed that the stability of dihydromyricetin in the extracts obtained by these methods was significantly lower than that of the present invention. For example, the extracts were prepared according to the methods described in specifications [0019] to [0024] of CN 101805321A (Chinese patent application No. 2010101490141), and had a residual content of dihydromyricetin of 86.6%. For another example, the extract was prepared according to the method of CN1810798A (Chinese patent application No. 200510032918.5) specification example 1, and the residual content of dihydromyricetin was 84.3%.

Test example 3: biological activity of white tea extract

According to the method of the literature of Cholescent developed from Cholescent. The results of the study of the hypoglycemic activity of the white tea extract of the present invention using the extract of example 1 of the present invention as a sample with reference to the method of the publication of kohlu et al (kohlu et al, research on the anti-fatigue activity of dihydromyricetin, journal of china pharmacy, 2016, 23 th) show that the white tea extract rich in dihydromyricetin of the present invention has a similar effect to the results of the publication, and confirm that the white tea extract rich in dihydromyricetin of the present invention has a definite anti-fatigue activity. Referring to the method of the Wangcangqi et al (Wangcangqi et al, comparison research on the anti-inflammatory activity of dihydroquercetin and dihydromyricetin, J.Chinese veterinary medicine, 2016, stage 07), the anti-inflammatory activity of the white tea extract of the present invention was studied by using the extract of the present invention in example 1 as a sample, and the results showed that the white tea extract rich in dihydromyricetin of the present invention has an exact anti-inflammatory activity.

Example 1: preparation of white tea extract

(1) Providing Ampelopsis grossedentata leaves which are dried (dried in the sun) to have the water content of 6%, and crushing the Ampelopsis grossedentata leaves into coarse powder to obtain dry powder of the leaves of the Ampelopsis plant;

(2) soaking Ampelopsis plant leaf dry powder in 6 times of water (containing 0.75% (v/v) ethyl acetate) for 2 hr, decocting for 45min, and filtering to obtain filtrate; decocting the residue with 4 times of water (containing 0.4% (v/v) ethyl acetate), and filtering to obtain filtrate; mixing the two filtrates;

(3) adding kaolin (1.25% of the filtrate) and propylene glycol (0.3% of the filtrate), stirring, standing for 3 hr, and concentrating under reduced pressure at 55 deg.C to 1/4 volume; adding ethanol until the ethanol content reaches 65%, stirring, standing for 7.5 hr, and filtering to remove solid;

(4) concentrating under reduced pressure at 60 deg.C until no alcohol smell exists, and spray drying until water content is less than 4% to obtain white tea extract. Which in the present invention may be labeled Ex 1.

The recovery rate of dihydromyricetin in the extract is 88%.

The content of dihydromyricetin in the extract accounts for 81% of the total weight of the extract.

In addition, the present inventors prepared the white tea extract by referring to the prior art methods which have been searched, and as a result, it was revealed that the recovery rate and content of dihydromyricetin in the extracts obtained by these methods could not reach the range of 80-90% and 65-85% of the present invention at the same time. For example, the extracts were prepared according to the methods in [0019] to [0024] of the specifications of CN 101805321 a (chinese patent application No. 2010101490141), and the recovery rate and content of dihydromyricetin in the extracts were 44.6% and 80.3%, respectively. For another example, the extract was prepared according to the method of CN1810798A (chinese patent application No. 200510032918.5) specification example 1, and the recovery rate and content of dihydromyricetin in the extract were 27.8% and 42.6%, respectively.

Example 2: preparation of white tea extract

(1) Providing Ampelopsis grossedentata leaves which are dried (air-dried) to have the moisture content of 8%, and crushing the Ampelopsis grossedentata leaves into coarse powder to obtain dry powder of the leaves of the Ampelopsis plant;

(2) soaking Ampelopsis plant leaf dry powder in 8 times of water (containing 1% (v/v) ethyl acetate) for 1 hr, decocting for 60min, and filtering to obtain filtrate; decocting the residue with 3 times of water (containing 0.5% (v/v) ethyl acetate), and filtering to obtain filtrate; mixing the two filtrates;

(3) adding kaolin (1.5% of the filtrate) and propylene glycol (0.2% of the filtrate), stirring, standing for 2 hr, and concentrating under reduced pressure at 60 deg.C to 1/5 volume; adding ethanol until the ethanol content reaches 70%, stirring, standing for 6 hr, and filtering to remove solid;

(4) concentrating under reduced pressure at 55 deg.C until no alcohol smell exists, and spray drying until water content is less than 3% to obtain white tea extract. Which in the present invention may be labeled Ex 2.

The recovery rate of dihydromyricetin in the extract is 82%.

The content of dihydromyricetin in the extract accounts for 83% of the total weight of the extract.

Example 3: preparation of white tea extract

(1) Providing Ampelopsis grossedentata leaves which are dried (thermally dried) to have the moisture content of 7%, and crushing the Ampelopsis grossedentata leaves into coarse powder to obtain dry powder of the leaves of the Ampelopsis plant;

(2) soaking Ampelopsis plant leaf dry powder in 5 times of water (containing 0.5% (v/v) ethyl acetate) for 3 hr, decocting for 30min, and filtering to obtain filtrate; decocting the residue with 6 times of water (containing 0.25(v/v) ethyl acetate), for 30min, and filtering to obtain filtrate; mixing the two filtrates;

(3) adding kaolin (1% of the filtrate) and propylene glycol (0.4% of the filtrate), stirring, standing for 4 hr, and concentrating under reduced pressure at 50 deg.C to 1/3 volume; adding ethanol until the ethanol content reaches 60%, stirring, standing for 10 hr, and filtering to remove solid;

(4) concentrating under reduced pressure at 65 deg.C until no alcohol smell exists, and spray drying until water content is less than 5% to obtain white tea extract. Which in the present invention may be labeled Ex 3.

The recovery rate of dihydromyricetin in the extract is 88%.

The content of dihydromyricetin in the extract accounts for 67% of the total weight of the extract.

Example 4: preparation of white tea extract

(1) Providing Ampelopsis grossedentata leaves which are dried (dried in the sun) until the water content is 6%, and crushing the Ampelopsis grossedentata leaves into coarse powder to obtain dry powder of the leaves of the Ampelopsis plant;

(2) soaking Ampelopsis plant leaf dry powder in 6 times of water (containing 0.5% (v/v) ethyl acetate) for 2 hr, decocting for 40 min, and filtering to obtain filtrate; decocting the residue with 5 times of water (containing 0.3% (v/v) ethyl acetate), and filtering to obtain filtrate; mixing the two filtrates;

(3) adding kaolin (1.4% of the filtrate) and propylene glycol (0.35% of the filtrate), stirring, standing for 2.5 hr, and concentrating under reduced pressure at 55 deg.C to 1/4 volume; adding ethanol until the ethanol content reaches 68%, stirring, standing for 7 hr, and filtering to remove solid;

(4) concentrating under reduced pressure at 58 deg.C until no alcohol smell exists, and spray drying until water content is less than 4% to obtain white tea extract. Which in the present invention may be labeled Ex 4.

The recovery rate of dihydromyricetin in the extract is 87%.

The content of dihydromyricetin in the extract accounts for 73% of the total weight of the extract.

Example 5: preparation of white tea extract

(1) Providing Ampelopsis grossedentata leaves which are dried (thermally dried) to have the moisture content of 8%, and crushing the Ampelopsis grossedentata leaves into coarse powder to obtain dry powder of the leaves of the Ampelopsis plant;

(2) soaking dried leaves of Ampelopsis plant in 7 times of water (containing 1% (v/v) ethyl acetate) for 2 hr, decocting for 45min, and filtering to obtain filtrate; decocting the residue with 4 times of water (containing 0.4% (v/v) ethyl acetate), for 50 min, and filtering to obtain filtrate; mixing the two filtrates;

(3) adding kaolin (1.1% of the filtrate) and propylene glycol (0.25% of the filtrate), stirring, standing for 3.5 hr, and concentrating under reduced pressure at 55 deg.C to 1/4 volume; adding ethanol until the ethanol content reaches 63%, stirring, standing for 8 hr, and filtering to remove solid;

(4) concentrating under reduced pressure at 63 deg.C until no alcohol smell exists, and spray drying until water content is less than 5% to obtain white tea extract. Which in the present invention may be labeled Ex 5.

The recovery rate of dihydromyricetin in the extract is 83%.

The content of dihydromyricetin in the extract is 78% of the total weight of the extract.

Composition example 1: preparation of white tea composition

The extracts obtained in examples 1 to 5 were taken, respectively, and formulated with water to give oral solutions in which the concentration of the extract was 10%, and 0.15% of aspartame was added as a sweetener to give compositions in the form of five oral liquids.

Composition example 2: preparation of white tea composition

The extracts obtained in examples 1 to 5 were respectively taken, added with 2 times of sucrose and 4 times of dextrin and 0.025% aspartame as sweeteners, mixed uniformly and granulated to obtain five compositions in the form of granules.

Composition example 3: preparation of white tea composition

Taking the extracts obtained in examples 1 to 5 respectively, adding 32 times of sucrose and 4 times of dextrin, mixing uniformly, preparing wet granules by using water as a wetting agent, drying, adding 0.5% of magnesium stearate into the dry granules, mixing uniformly, and tabletting, wherein each tablet is 0.45g to obtain five compositions in the form of tablets.

Claims

1. A method for preparing a white tea extract rich in dihydromyricetin, comprising the steps of:

(2) adding 5-8 times of water into the ampelopsis plant leaf dry powder, soaking for 1-3 hours, then decocting for 30-120 minutes, and filtering to obtain filtrate; adding 3-6 times of water into filter residues, decocting for 30-120 minutes, and filtering to obtain filtrate; mixing the two filtrates; wherein, ethyl acetate with the volume of water accounting for 0.5-2 v/v% is added along with the first water addition, and ethyl acetate with the volume of water accounting for 0.25-1 v/v% is added along with the second water addition to the filter residue;

(3) adding kaolin and propylene glycol into the filtrate, uniformly stirring, standing for 2-4 hours, and concentrating under reduced pressure at 50-70 ℃ to 1/5-1/3 volume; adding ethanol until the ethanol content reaches 60-70%, uniformly stirring, standing for 6-10 hours, and filtering to remove solid matters; the amount of the kaolin is 1-2% of the amount of the filter liquor, and the amount of the propylene glycol is 0.2-0.6% of the amount of the filter liquor;

2. The method according to claim 1, wherein in step (1) said Ampelopsis plant is selected from Ampelopsis grossedentata or Ampelopsis megalophylla.

3. The method according to claim 1, wherein in step (1), the drying is a drying mode selected from the group consisting of: air drying, sun drying, or heat drying.

4. The method according to claim 1, wherein in step (1), the drying is carried out to a moisture content of less than 8%.

5. The method according to claim 1, wherein in the step (2), 5 to 6 times of water is added for the first time to soak.

6. The method according to claim 1, wherein in the step (2), 5 to 6 times of water is added for soaking for 1 to 2 hours for the first time.

7. The method according to claim 1, wherein in the step (2), 5 to 6 times of water is added for the first time to soak for 1 to 2 hours, and then the decoction is carried out for 30 to 60 minutes.

8. The method according to claim 1, wherein 0.5 to 1 v/v% by volume of ethyl acetate is further added with the first addition of water in step (2).

9. The method according to claim 1, wherein in the step (2), the residue is decocted with 3-4 times of water.

10. The method according to claim 1, wherein in the step (2), the residue is added with 3-4 times of water and decocted for 30-60 minutes.

11. The method according to claim 1, wherein in the step (2), 0.25-0.5 v/v% by volume of ethyl acetate is further added with the second addition of water to the residue.

12. A method according to claim 1, wherein in the step (3), the amount of the kaolin is 1 to 1.5% based on the amount of the filtrate.

13. The method according to claim 1, wherein in the step (3), the amount of propylene glycol is 0.2 to 0.4% based on the amount of the filtrate.

14. The method according to claim 1, wherein in the step (3), kaolin and propylene glycol are added into the filtrate, the mixture is uniformly stirred and is kept stand for 2 to 3 hours.

15. The method according to claim 1, wherein in the step (3), kaolin and propylene glycol are added into the filtrate, the mixture is stirred uniformly, kept stand for 2 to 3 hours and concentrated under reduced pressure at 50 to 60 ℃.

16. The method according to claim 1, wherein in the step (3), kaolin and propylene glycol are added into the filtrate, the mixture is stirred uniformly, kept stand for 2-3 hours and concentrated under reduced pressure at 50-60 ℃ to 1/5-1/4 volume.

17. The method according to claim 1, wherein in the step (3), ethanol is added until the ethanol content reaches 60-65%.

18. The method according to claim 1, wherein in the step (3), ethanol is added until the ethanol content reaches 60-65%, the mixture is uniformly stirred, kept stand for 7-9 hours, and filtered to remove solids.

19. The method according to claim 1, wherein in the step (4), the mixture is concentrated under reduced pressure at 55 to 65 ℃ until no alcohol smell is generated.

20. The method according to claim 1, wherein in the step (4), the white tea extract is obtained by concentrating under reduced pressure at 55-65 ℃ until no alcohol smell is produced, and then spray-drying until the water content is less than 4%.

21. The method according to claim 1, wherein the extract of white tea contains dihydromyricetin 60-90 wt% of the total weight of the extract.

22. A white tea extract comprises dihydromyricetin, and the amount of dihydromyricetin accounts for 60-90% of the total weight of the extract; the white tea extract is prepared by the method of any one of claims 1 to 21.

23. A composition comprising the white tea extract of claim 22 or prepared by the method of any one of claims 1 to 21, and a physiologically acceptable excipient.

24. A composition according to claim 23, wherein the excipient is selected from diluents and flavoring agents, the diluents are selected from water, sucrose, starch, dextrin, lactose, and the flavoring agents are selected from aspartame, sodium saccharin, acesulfame potassium.

25. The composition according to claim 23, which is in the form of a formulation of tablets, granules or oral solutions.

26. Use of the white tea extract produced by the method of any one of claims 1 to 21 or the white tea extract of claim 22 for the preparation of a product for scavenging free radicals, anti-oxidation, anti-thrombosis, anti-tumor, anti-bacterial anti-inflammatory, relieving alcoholism and anti-hangover, preventing alcoholic and fatty liver, inhibiting hepatocyte deterioration, reducing incidence of liver cancer, anti-hypertension, inhibiting in vitro platelet aggregation and in vivo thrombosis formation, reducing blood lipid and blood glucose levels, increasing SOD activity, protecting liver and activating AMPK, inhibiting hyperglycemia-induced vascular endothelial cell apoptosis, inhibiting liver fat accumulation, inhibiting hepatic stellate cell activation, inhibiting lung adenocarcinoma cell proliferation, hypnosis, and/or anti-fatigue.