Method for extracting plant raw materials by using eutectic solvent and application of method

Abstract

The invention discloses a method for extracting a plant raw material by using a deep-eutectic solvent and application of the method, and provides a method for efficiently extracting flavone, caffeine and saponin from the plant raw material by using the deep-eutectic solvent, so that the yield of an active product is increased. The deep-eutectic solvent is utilized, the flavone, the caffeine, the saponin and the cocamidopropyl betaine are based on the flavone, the caffeine, the saponin and the cocamidopropyl betaine, the betaine and the polyhydric alcohol jointly form a hydrogen bond network to improve the extraction rate, and scalp absorption of the flavone, the caffeine and the saponin is promoted. The method has important significance on application of flavone, caffeine and saponin extracting solutions.

Description

Technical Field

[0001] The invention belongs to the technical field of daily chemical industry, and particularly relates to a method for extracting plant raw materials with a low eutectic solvent and application thereof. Background Art

[0002] Tea bran, also known as tea dregs, is purple-brown particles and is the residue left after the oil is squeezed from camellia oil fruit. Tea bran is rich in flavonoids. As a secondary metabolite of plants, flavonoids have anti-allergic, antibacterial and anti-hair loss activities. Caffeine is the main alkaloid in coffee seeds, with the scientific name 1,3,7-trimethyl-2,6-dioxopurine, which has the effects of stimulating the central nervous system and aiding digestion. There are two main technologies for flavonoids extraction: water extraction and alcohol extraction. There are problems of low extraction efficiency and low transdermal absorption rate. Alcohol extraction requires solvent concentration and freeze drying, which consumes a lot of energy, has a long production cycle and may destroy the active structure of flavonoids. The main technologies for extracting caffeine include solvent method, sublimation method, supercritical CO2 method, etc. The solvent method involves chlorohalogenated hydrocarbons, which have certain toxicity. The sublimation method and supercritical CO2 method have the problems of high equipment requirements and high energy consumption, and cannot be industrialized.

[0003] Gleditsia sinensis and Soapberry are the main species resources of natural plant surfactants. Gleditsia sinensis and Soapberry are found in southern and northern my country and have a long history of application. There are two technical methods for extracting saponins: water extraction and alcohol extraction. Alcohol extraction can obtain relatively pure and stable saponins, but the production cost is high, and the large-scale use of ethanol poses certain safety hazards, and the safety standards for production sites and equipment are high. Water extraction is low-cost, safe and simple, but it has problems such as low extraction efficiency, low purity of total saponins, and low transdermal efficiency. Summary of the invention

[0004] The purpose of this section is to summarize some aspects of embodiments of the present invention and to briefly introduce some preferred embodiments.

[0005] As one aspect of the present invention, the present invention provides a method for extracting plant raw materials with a low eutectic solvent, wherein: the plant raw material is added to the low eutectic solvent, heated for extraction, and filtered to obtain an extract; the low eutectic solvent consists of cocamidopropyl betaine, betaine, dipropylene glycol and water, and the molar ratio of cocamidopropyl betaine, betaine and dipropylene glycol in the low eutectic solvent is 1:1~2:1~2.

[0006] As a preferred embodiment of the method for extracting plant raw materials with a low eutectic solvent according to the present invention: in the low eutectic solvent, the concentration of cocamidopropyl betaine is 0.1-0.5 mol / L.

[0007] As a preferred embodiment of the method for extracting plant raw materials with a low eutectic solvent according to the present invention, the solid-liquid ratio of the plant raw material to the low eutectic solvent is 1:5-25.

[0008] As a preferred embodiment of the method for extracting plant raw materials with a low eutectic solvent according to the present invention, the heating extraction comprises stirring extraction at 30 to 70° C. for 1 to 5 hours.

[0009] As a preferred embodiment of the method for extracting plant raw materials with a low eutectic solvent according to the present invention: the filtration comprises filtering with a 220-45 nm filter membrane.

[0010] As a preferred embodiment of the method for extracting plant raw materials with a low eutectic solvent according to the present invention, the solid-liquid ratio of the plant raw material to the low eutectic solvent is 1:10-20.

[0011] As a preferred embodiment of the method for extracting plant raw materials with a deep eutectic solvent of the present invention: the plant raw materials include one or more of tea bran, small-fruit coffee, Chinese honey locust, and soapberry. For example, the plant raw materials include tea bran and small-fruit coffee, the plant raw materials include tea bran, small-fruit coffee, and Chinese honey locust, the plant raw materials include tea bran, small-fruit coffee, and soapberry, etc.

[0012] As a preferred embodiment of the method for extracting plant raw materials with a low eutectic solvent according to the present invention: the source of the tea bran includes tea seeds.

[0013] As a preferred embodiment of the method for extracting plant raw materials with a low eutectic solvent according to the present invention: the source of the tea bran includes camellia seeds and / or camellia seeds.

[0014] As a preferred embodiment of the method for extracting plant raw materials with a low eutectic solvent according to the present invention: the plant raw materials include tea bran, small-fruit coffee, saponin, and soapberry mixed in a ratio of 1:0.5-5:0.5-5:0.5-5.

[0015] Beneficial effects of the present invention: The present invention provides a method for efficiently extracting flavonoids, caffeine and saponin from plant raw materials using a low eutectic solvent, thereby increasing the yield of active products. The present invention utilizes a low eutectic solvent, based on flavonoids, caffeine, saponin and cocamidopropyl betaine, betaine and polyols to form a hydrogen bond network to increase the extraction rate, and promotes the scalp absorption of flavonoids, caffeine and saponin. It is of great significance for the application of flavonoids, caffeine and saponin extracts. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solution of the embodiment of the present invention, the following briefly introduces the drawings required for describing the embodiment, wherein:

[0017] Figure 1The plant extracts prepared in Examples 1 to 3. DETAILED DESCRIPTION

[0018] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with specific embodiments.

[0019] Embodiment 1:

[0020] (1) Preparing plant raw materials: Camellia oleifera Abel tea bran, Coffea arabica, Gleditsia sinensis Lam and Sapindus saponaria Linnaeus are ground and mixed in a mass ratio of 1:1:1:1, passed through an 80-mesh sieve and dried to obtain the plant raw materials.

[0021] (2) Preparation of a low eutectic solvent: cocamidopropyl betaine (CAB), betaine, dipropylene glycol (DPG), and water were mixed and stirred at 60° C. for 1 h to obtain a low eutectic solvent, wherein the concentration of cocamidopropyl betaine (CAB) in the low eutectic solvent was 0.25 mol / L, the concentration of betaine in the low eutectic solvent was 0.5 mol / L, and the concentration of dipropylene glycol (DPG) in the low eutectic solvent was 0.25 mol / L, i.e., n CAB :n 甜菜碱 :n DPG =1:2:1.

[0022] (3) Plant material extraction: The plant material obtained in step (1) is added to the low eutectic solvent obtained in step (2) at a solid-liquid ratio of 1:10 (g:mL). The mixture is stirred and extracted at 60°C for 2 h at a stirring rate of 50 r / m. After the extraction, the mixture is filtered with a 220 nm filter membrane to obtain an extract.

[0023] The yields of flavonoids, caffeine and saponin in the extract were determined to be 14.89 mg / g, 13.65 mg / g and 69.50 mg / g, respectively.

[0024] Embodiment 2:

[0025] (1) Preparing plant raw materials: Camellia oleifera Abel tea bran, Coffea arabica, Gleditsia sinensis Lam and Sapindus saponaria Linnaeus are ground and mixed in a mass ratio of 1:1:1:1, passed through an 80-mesh sieve and dried to obtain the plant raw materials.

[0026] (2) Preparation of a low eutectic solvent: Cocamidopropyl betaine (CAB), betaine, dipropylene glycol (DPG), and water were mixed and stirred at 60° C. for 1 h to obtain a low eutectic solvent, wherein the concentration of cocamidopropyl betaine (CAB) was 0.25 mol / L, the concentration of betaine was 0.25 mol / L, and the concentration of dipropylene glycol (DPG) was 0.5 mol / L, i.e., n CAB :n 甜菜碱 :n DPG =1∶1∶2.

[0027] (3) Plant material extraction: The plant material obtained in step (1) is added to the low eutectic solvent obtained in step (2) at a solid-liquid ratio of 1:10 (g:mL). The mixture is stirred and extracted at 60°C for 2 h at a stirring rate of 50 r / m. After the extraction, the mixture is filtered with a 220 nm filter membrane to obtain an extract.

[0028] The yields of flavonoids, caffeine and saponin in the extract were determined to be 12.56 mg / g, 12.07 mg / g and 63.32 mg / g, respectively.

[0029] Embodiment 3:

[0030] (1) Preparing plant raw materials: Coffea arabica, Gleditsia sinensis Lam, and Sapindus saponaria Linnaeus are ground and mixed in a mass ratio of 1:1:1:1, and then passed through an 80-mesh sieve and dried to obtain the plant raw materials.

[0031] (2) Preparation of a low eutectic solvent: Mix cocamidopropyl betaine (CAB), betaine, dipropylene glycol (DPG), and water, and stir at 60° C. for 1 h to obtain a low eutectic solvent, wherein the concentration of cocamidopropyl betaine (CAB) is 0.25 mol / L, the concentration of betaine is 0.5 mol / L, and the concentration of dipropylene glycol (DPG) is 0.25 mol / L, i.e., n CAB :n 甜菜碱 :n DPG =1:2:1.

[0032] (3) Plant material extraction: The plant material obtained in step (1) was added to the low eutectic solvent obtained in step (2) at a solid-liquid ratio of 1:20 (g:mL). The mixture was stirred and extracted at 60°C for 2 h at a stirring rate of 50 r / m. After the extraction, the mixture was filtered with a 220 nm filter membrane to obtain an extract.

[0033] The yields of flavonoids, caffeine and saponin in the extract were determined to be 13.92 mg / g, 12.46 mg / g and 65.59 mg / g, respectively. Figure 1The plant extracts prepared in Examples 1 to 3 are Example 1, Example 2, and Example 3 from left to right.

[0034] Embodiment 4:

[0035] (1) Preparing plant raw materials: Camellia oleifera Abel tea bran and Coffea arabica are ground into powder in a mass ratio of 1:1, mixed, passed through an 80-mesh sieve, and dried to obtain the plant raw materials.

[0036] (2) Preparation of a low eutectic solvent: cocamidopropyl betaine (CAB), betaine, dipropylene glycol (DPG), and water were mixed and stirred at 60° C. for 1 h to obtain a low eutectic solvent, wherein the concentration of cocamidopropyl betaine (CAB) in the low eutectic solvent was 0.25 mol / L, the concentration of betaine in the low eutectic solvent was 0.5 mol / L, and the concentration of dipropylene glycol (DPG) in the low eutectic solvent was 0.25 mol / L, i.e., n CAB :n 甜菜碱 :n DPG =1:2:1.

[0037] (3) Plant material extraction: The plant material obtained in step (1) is added to the low eutectic solvent obtained in step (2) at a solid-liquid ratio of 1:10 (g:mL). The mixture is stirred and extracted at 60°C for 2 h at a stirring rate of 50 r / m. After the extraction, the mixture is filtered with a 220 nm filter membrane to obtain an extract.

[0038] The yields of flavonoids and caffeine in the extract were determined to be 16.31 mg / g and 14.28 mg / g respectively.

[0039] Embodiment 5:

[0040] (1) Preparing plant raw materials: Camellia oleifera Abel tea bran, Coffea arabica and Gleditsia sinensis Lam were ground and mixed in a mass ratio of 1:1:1, passed through an 80-mesh sieve and dried to obtain the plant raw materials.

[0041] (2) Preparation of a low eutectic solvent: cocamidopropyl betaine (CAB), betaine, dipropylene glycol (DPG), and water were mixed and stirred at 60° C. for 1 h to obtain a low eutectic solvent, wherein the concentration of cocamidopropyl betaine (CAB) in the low eutectic solvent was 0.25 mol / L, the concentration of betaine in the low eutectic solvent was 0.5 mol / L, and the concentration of dipropylene glycol (DPG) in the low eutectic solvent was 0.25 mol / L, i.e., n CAB :n 甜菜碱 :n DPG=1:2:1.

[0042] (3) Plant material extraction: The plant material obtained in step (1) is added to the low eutectic solvent obtained in step (2) at a solid-liquid ratio of 1:10 (g:mL). The mixture is stirred and extracted at 60°C for 2 h at a stirring rate of 50 r / m. After the extraction, the mixture is filtered with a 220 nm filter membrane to obtain an extract.

[0043] Embodiment 6:

[0044] (1) Preparing plant raw materials: Camellia oleifera Abel tea bran, Coffea arabica and Sapindus saponaria Linnaeus are ground and mixed in a mass ratio of 1:1:1, passed through an 80-mesh sieve and dried to obtain the plant raw materials.

[0045] (2) Preparation of a low eutectic solvent: cocamidopropyl betaine (CAB), betaine, dipropylene glycol (DPG), and water were mixed and stirred at 60° C. for 1 h to obtain a low eutectic solvent, wherein the concentration of cocamidopropyl betaine (CAB) in the low eutectic solvent was 0.25 mol / L, the concentration of betaine in the low eutectic solvent was 0.5 mol / L, and the concentration of dipropylene glycol (DPG) in the low eutectic solvent was 0.25 mol / L, i.e., n CAB :n 甜菜碱 :n DPG =1:2:1.

[0046] (3) Plant material extraction: The plant material obtained in step (1) is added to the low eutectic solvent obtained in step (2) at a solid-liquid ratio of 1:10 (g:mL). The mixture is stirred and extracted at 60°C for 2 h at a stirring rate of 50 r / m. After the extraction, the mixture is filtered with a 220 nm filter membrane to obtain an extract.

[0047] Comparative Example 1:

[0048] (1) Preparing plant raw materials: Camellia oleifera Abel tea bran, Coffea arabica, Gleditsia sinensis Lam, and Sapindus saponaria Linnaeus are ground and mixed in a mass ratio of 1:1:1:1, passed through an 80-mesh sieve, and dried to obtain the plant raw materials.

[0049] (2) Plant material extraction: The plant material obtained in step (1) was added into water with a solid-liquid ratio of 1:10 (g:mL). The mixture was stirred and extracted at 60°C for 2 h with a stirring rate of 50 r / m. After the extraction, the mixture was filtered with a 220 nm filter membrane to obtain an extract.

[0050] The yields of flavonoids, caffeine and saponin in the extract were determined to be 8.12 mg / g, 9.23 mg / g and 43.17 mg / g, respectively.

[0051] Comparative Example 2:

[0052] (1) Preparing plant raw materials: Camellia oleifera Abel tea bran, Coffea arabica, Gleditsia sinensis Lam and Sapindus saponaria Linnaeus are ground and mixed in a mass ratio of 1:1:1:1, passed through an 80-mesh sieve and dried to obtain the plant raw materials.

[0053] (2) Preparation of a low eutectic solvent: betaine, dipropylene glycol (DPG) and water were mixed and stirred at 60°C for 1 h to obtain a low eutectic solvent, wherein the concentration of betaine in the low eutectic solvent was 0.25 mol / L, and the concentration of dipropylene glycol (DPG) in the low eutectic solvent was 0.5 mol / L, i.e., n 甜菜碱 :n DPG =1:2.

[0054] (3) Plant material extraction: The plant material obtained in step (1) is added to the low eutectic solvent obtained in step (2) at a solid-liquid ratio of 1:10 (g:mL). The mixture is stirred and extracted at 60°C for 2 h at a stirring rate of 50 r / m. After the extraction, the mixture is filtered with a 220 nm filter membrane to obtain an extract.

[0055] The yields of flavonoids, caffeine and saponin in the extract were determined to be 9.23 mg / g, 10.52 mg / g and 52.79 mg / g, respectively.

[0056] Comparative Example 3:

[0057] (1) Preparing plant raw materials: Camellia oleifera Abel tea bran, Coffea arabica, Gleditsia sinensis Lam and Sapindus saponaria Linnaeus are ground and mixed in a mass ratio of 1:1:1:1, passed through an 80-mesh sieve and dried to obtain the plant raw materials.

[0058] (2) Preparation of a low eutectic solvent: betaine, dipropylene glycol (DPG) and water were mixed and stirred at 60°C for 1 h to obtain a low eutectic solvent, wherein the concentration of betaine in the low eutectic solvent was 0.5 mol / L, and the concentration of dipropylene glycol (DPG) in the low eutectic solvent was 0.25 mol / L, i.e., n 甜菜碱 :nDPG =2:1.

[0059] (3) Plant material extraction: The plant material obtained in step (1) is added to the low eutectic solvent obtained in step (2) at a solid-liquid ratio of 1:10 (g:mL). The mixture is stirred and extracted at 60°C for 2 h at a stirring rate of 50 r / m. After the extraction, the mixture is filtered with a 220 nm filter membrane to obtain an extract.

[0060] The yields of flavonoids, caffeine and saponin in the extract were determined to be 9.76 mg / g, 10.23 mg / g and 56.71 mg / g, respectively.

[0061] Comparative Example 4:

[0062] (1) Preparing plant raw materials: Camellia oleifera Abel tea bran, Coffea arabica, Gleditsia sinensis Lam and Sapindus saponaria Linnaeus are ground and mixed in a mass ratio of 1:1:1:1, passed through an 80-mesh sieve and dried to obtain the plant raw materials.

[0063] (2) Preparation of a low eutectic solvent: Mix cocamidopropyl betaine (CAB), alanine, dipropylene glycol (DPG), and water, and stir at 60° C. for 1 h to obtain a low eutectic solvent, wherein the concentration of cocamidopropyl betaine (CAB) in the low eutectic solvent is 0.25 mol / L, the concentration of alanine in the low eutectic solvent is 0.5 mol / L, and the concentration of dipropylene glycol (DPG) in the low eutectic solvent is 0.25 mol / L, that is, n CAB :n 丙氨酸 :n DPG =1:2:1.

[0064] (3) Plant material extraction: The plant material obtained in step (1) is added to the low eutectic solvent obtained in step (2) at a solid-liquid ratio of 1:10 (g:mL). The mixture is stirred and extracted at 60°C for 2 h at a stirring rate of 50 r / m. After the extraction, the mixture is filtered with a 220 nm filter membrane to obtain an extract.

[0065] Comparative Example 5:

[0066] (1) Preparing plant raw materials: Camellia oleifera Abel tea bran, Coffea arabica, Gleditsia sinensis Lam and Sapindus saponaria Linnaeus are ground and mixed in a mass ratio of 1:1:1:1, passed through an 80-mesh sieve and dried to obtain the plant raw materials.

[0067] (2) Preparation of a low eutectic solvent: cocamidopropyl betaine (CAB), arginine, dipropylene glycol (DPG), and water were mixed and stirred at 60° C. for 1 h to obtain a low eutectic solvent, wherein the concentration of cocamidopropyl betaine (CAB) in the low eutectic solvent was 0.25 mol / L, the concentration of arginine in the low eutectic solvent was 0.5 mol / L, and the concentration of dipropylene glycol (DPG) in the low eutectic solvent was 0.25 mol / L, i.e., n CAB :n 精氨酸 :n DPG =1:2:1.

[0068] (3) Plant material extraction: The plant material obtained in step (1) is added to the low eutectic solvent obtained in step (2) at a solid-liquid ratio of 1:10 (g:mL). The mixture is stirred and extracted at 60°C for 2 h at a stirring rate of 50 r / m. After the extraction, the mixture is filtered with a 220 nm filter membrane to obtain an extract.

[0069] Comparative Example 6:

[0070] (1) Preparing plant raw materials: Camellia oleifera Abel tea bran, Coffea arabica, Gleditsia sinensis Lam and Sapindus saponaria Linnaeus are ground and mixed in a mass ratio of 1:1:1:1, passed through an 80-mesh sieve and dried to obtain the plant raw materials.

[0071] (2) Preparation of a low eutectic solvent: lauramidopropyl betaine, betaine, dipropylene glycol (DPG), and water were mixed and stirred at 60° C. for 1 h to obtain a low eutectic solvent, wherein the concentration of lauramidopropyl betaine in the low eutectic solvent was 0.25 mol / L, the concentration of betaine in the low eutectic solvent was 0.5 mol / L, and the concentration of dipropylene glycol (DPG) in the low eutectic solvent was 0.25 mol / L, i.e., n 月桂酰胺丙基甜菜碱 :n 甜菜碱 :n DPG =1:2:1.

[0072] (3) Plant material extraction: The plant material obtained in step (1) is added to the low eutectic solvent obtained in step (2) at a solid-liquid ratio of 1:10 (g:mL). The mixture is stirred and extracted at 60°C for 2 h at a stirring rate of 50 r / m. After the extraction, the mixture is filtered with a 220 nm filter membrane to obtain an extract.

[0073] Comparative Example 7:

[0074] (1) Preparing plant raw materials: Camellia oleifera Abel tea bran, Coffea arabica, Gleditsia sinensis Lam and Sapindus saponaria Linnaeus are ground and mixed in a mass ratio of 1:1:1:1, passed through an 80-mesh sieve and dried to obtain the plant raw materials.

[0075] (2) Preparation of a low eutectic solvent: cocamidopropyl betaine (CAB), betaine, hexylene glycol, and water were mixed and stirred at 60° C. for 1 h to obtain a low eutectic solvent, wherein the concentration of cocamidopropyl betaine (CAB) in the low eutectic solvent was 0.25 mol / L, the concentration of betaine in the low eutectic solvent was 0.5 mol / L, and the concentration of hexylene glycol in the low eutectic solvent was 0.25 mol / L, i.e., n CAB :n 甜菜碱 :n 己二醇 =1∶2:1.

[0076] (3) Plant material extraction: The plant material obtained in step (1) is added to the low eutectic solvent obtained in step (2) at a solid-liquid ratio of 1:10 (g:mL). The mixture is stirred and extracted at 60°C for 2 h at a stirring rate of 50 r / m. After the extraction, the mixture is filtered with a 220 nm filter membrane to obtain an extract.

[0077] The yields of flavonoids, caffeine and saponin in the extract were determined to be 10.52 mg / g, 10.68 mg / g and 58.75 mg / g, respectively.

[0078] Research example:

[0079] Experimental Materials and Methods

[0080] Buy fresh pig ears and scrape off the hair on the skin, peel the skin from the cartilage, clean the fat behind the skin with a brush, wash the processed pig skin with PBS, and then select the part with good skin condition, undamaged and uniform thickness, cut it off, dry the surface moisture with absorbent paper, and store it at -20℃ under pollution-free conditions for future use. When the prepared skin model needs to be used, take out the applicable part in advance, soak it in PBS for 1 hour, and use it after drying the surface moisture with absorbent paper.

[0081] Before the transdermal experiment, the initial active substance concentration in the supply pool of each transdermal group should be kept the same, and the extracts obtained were diluted with the solvents of each experimental group. The flavonoid concentration in each experimental group was diluted to 500 μg / mL, the caffeine concentration was 1000 μg / mL, and the saponin concentration was 800 μg / mL. For example, the composition of the deep eutectic solvent in Example 1 is: CAB, betaine, DPG and water, and the deep eutectic solvent is also used as the diluent.

[0082] The modified Franz diffusion cell method was used to fix the pig skin between the supply cell and the receiving cell, with the stratum corneum facing the supply cell. The receiving liquid was PBS, and the receiving cell was kept in a constant temperature water bath at (37±0.2)℃, with magnetic stirring at a speed of 300r / min. After 12h, the liquid in the receiving cell was sampled to determine the concentration of active substances in the receiving cell. The absorbance was determined in a MultiskanFC microplate reader.

[0083] Flavonoid content determination method: accurately weigh 10.0 mg of rutin standard, dissolve it in 60% ethanol, transfer it to a 100 mL volumetric flask, dilute to volume and shake well to obtain a 0.1 mg / mL rutin standard solution. Accurately pipette 0, 0.2, 0.4, 0.8, 1.0, and 2.0 mL of 0.1 mg / mL rutin mother solution into 10 mL stoppered test tubes, and add 0.3 mL of 5% NaNO2 to each stoppered test tube. Shake well and let stand for 6 minutes, then add 0.3 mL of 10% Al(NO3)3, shake well and let stand for 6 minutes. Add 4 mL of freshly prepared 1 mol / L NaOH solution, dilute to the scale line of the stoppered test tube with 60% ethanol, shake well and let stand for 15 minutes, measure the absorbance of the solution at a wavelength of 510 nm, and draw a rutin standard curve by plotting absorbance-rutin concentration.

[0084] Repeat the preparation steps of the standard curve for the flavonoid content in the transdermal sample. Simply, add 100 μL of transdermal sample to each well of the 12-well plate, and then add 15 μL of 5% NaNO2, 15 μL of 10% Al(N03)3, and 200 μL of freshly prepared 1 mol / L NaOH solution according to the standard curve preparation process. Use 60% ethanol to make the volume 2 mL, shake well and let stand for 15 minutes, measure the absorbance of the solution at a wavelength of 510 nm, and bring the obtained absorbance into the standard curve to calculate the concentration. The formula for calculating the transdermal absorption rate is as follows:

[0085] Transdermal absorption rate (%) = (C2V2) / (C1V1) * 100%

[0086] Where: C2 is the concentration of flavonoids in the receiving pool, V2 is the volume of the receiving pool (7mL)

[0087] C1 is the flavonoid concentration in the supply pool, V1 is the volume of the supply pool (1 mL)

[0088] Caffeine content determination method: Weigh 100 mg of caffeine (purity> 99%) and dissolve it in 100 mL of water as the mother solution. Accurately draw 5 mL and add water to 100 mL as the working solution (0.05 mg / mL). Draw 0.0 mL, 1.0 mL, 2.0 mL, 3.0 mL, 4.0 mL, 5.0 mL, and 6.0 mL of caffeine working solution into a group of 25 mL volumetric flasks, add 1.0 mL of hydrochloric acid (0.01 mol / L) to each, dilute with water to the scale and mix well, use a 10 mm quartz colorimetric cup, at a wavelength of 274 nm, with the reagent blank solution as a reference, to determine the absorbance value. Draw a standard curve with the measured absorbance and the corresponding caffeine concentration.

[0089] Determination of caffeine content in transdermal samples: After adding 200 μL of transdermal sample to each well of the 12-well plate, add 400 μL of hydrochloric acid (0.01 mol / L), 100 μL of basic lead acetate solution (50 g of basic lead acetate, add 100 mL of water, and let stand overnight), and finally dilute to 2 mL with water, mix, let stand, and clarify and filter. Add 1 mL of clarified filtrate and 40 μL of sulfuric acid solution (4.5 mol / L) to the 12-well plate, dilute to 2 mL with water, mix, let stand, clarify and filter. Add 1 mL of clarified filtrate to each 12-well plate, use the reagent blank solution as a reference at a wavelength of 274 nm, measure the absorbance value, bring the obtained absorbance value into the standard curve, and calculate the concentration. The formula for calculating transdermal absorption rate is as follows:

[0090] Transdermal absorption rate (%) = (C2V2) / (C1V1) * 100%

[0091] Where: C2 is the caffeine concentration in the receiving cell, V2 is the volume of the receiving cell (7mL)

[0092] C1 is the caffeine concentration in the supply cell, V1 is the volume of the supply cell (1 mL)

[0093] Quantitative determination of saponin content by the vanillin-concentrated sulfuric acid method: Accurately weigh 10 mg of oleanolic acid standard, dissolve it in deionized water, and prepare it into a 1 mg / mL oleanolic acid aqueous solution in a 10 mL volumetric flask. Then use a pipette to accurately transfer 0, 0.1, 0.2, 0.3, 0.4, and 0.5 mL of the above standard solution into a 10 mL stoppered test tube, and add deionized water to make the volume to 0.5 mL, add 0.5 mL of 8% vanillin ethanol solution, add 4 mL 77% HSO4 to an ice water bath, shake well, and heat in a 60°C water bath for 25 minutes. After heating, put it in an ice water bath again to cool for use. Measure the absorbance value of this group of solutions at an absorption wavelength of 540 nm in a UV spectrophotometer. Draw a standard curve between the measured absorbance and the corresponding caffeine concentration.

[0094] The determination of saponin content in transdermal samples was carried out according to the standard curve steps, in which the volume of transdermal samples was 0.5 mL and was carried out in a 10 mL stoppered test tube. After the reaction was completed, 2 mL of the reaction solution was added to each group in a 12-well plate, and the absorbance value of each group of solutions was measured at an absorption wavelength of 540 nm and the concentration was calculated. The formula for calculating the transdermal absorption rate is as follows:

[0095] Transdermal absorption rate (%) = (C2V2) / (C1V1)*100%

[0096] Where: C2 is the saponin concentration in the receiving pool, V2 is the volume of the receiving pool (7mL)

[0097] C1 is the saponin concentration in the supply cell, and V1 is the volume of the supply cell (1 mL).

[0098] Table 1 is the test results of the transdermal absorption rate of each active component in the extract obtained in different embodiments

[0099]

[0100]

[0101] It can be seen from the experimental results in Table 1 that the low eutectic solvents of the examples can significantly improve the transdermal absorption rate of the active components.

[0102] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for extracting plant raw materials using a deep eutectic solvent, characterized in that: The plant raw material is added to a low eutectic solvent and heated for extraction, and an extract is obtained by filtering; wherein the low eutectic solvent is composed of cocamidopropyl betaine, betaine, dipropylene glycol and water, and the molar ratio of cocamidopropyl betaine, betaine and dipropylene glycol in the low eutectic solvent is 1:1-2:1-2.

2. The method for extracting plant raw materials with a deep eutectic solvent according to claim 1, characterized in that: In the low eutectic solvent, the concentration of cocamidopropyl betaine is 0.1-0.5 mol / L.

3. The method for extracting plant raw materials using a deep eutectic solvent according to claim 1 or 2, characterized in that: The material-liquid ratio of the plant raw material to the low eutectic solvent is 1:5-25.

4. The method for extracting plant raw materials using a deep eutectic solvent according to claim 1 or 2, characterized in that: The heating extraction comprises stirring and extracting at 30-70° C. for 1-5 hours.

5. The method for extracting plant raw materials using a deep eutectic solvent according to claim 1 or 2, characterized in that: The filtration includes filtering with a 220-450 nm filter membrane.

6. The method for extracting plant raw materials with a deep eutectic solvent according to claim 3, characterized in that: The material-liquid ratio of the plant raw material to the low eutectic solvent is 1:10-20.

7. The method for extracting plant raw materials using a deep eutectic solvent according to claim 1 or 2, characterized in that: The plant raw materials include one or more of tea bran, small-fruit coffee, saponin, and soapberry.

8. The method for extracting plant raw materials with a deep eutectic solvent according to claim 7, characterized in that: The source of the tea bran includes tea seeds.

9. The method for extracting plant raw materials with a deep eutectic solvent according to claim 7, characterized in that: The sources of the tea bran include camellia seeds and / or camellia seeds.

10. Use of the extract obtained by the method for extracting plant raw materials with a deep eutectic solvent according to claim 1 in cosmetics.

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