Amphiphilic tremella polysaccharide as well as preparation method and application thereof

Abstract

The invention discloses amphiphilic tremella polysaccharide as well as a preparation method and application thereof. The preparation method of the amphipathic tremella polysaccharide comprises the following steps: mixing a tremella polysaccharide solution and an activation reaction solution, and reacting to obtain the amphipathic tremella polysaccharide, wherein the tremella polysaccharide solution comprises tremella polysaccharide and a solvent; the activation reaction liquid comprises a water repellent agent, a catalyst and a solvent. The preparation method disclosed by the invention is high in yield, safe and convenient to operate, and the tremella polysaccharide is subjected to hydrophobic modification by the preparation method, so that the tremella polysaccharide has a proper hydrophobic group substitution degree, has the characteristic of amphipathicity, has high water absorption and lipophilicity, can be used as a good surfactant, and can be used as an amphiphilic surfactant. Meanwhile, the solubility of fat-soluble functional raw materials and the encapsulation efficiency of some active substances can be improved, and the method has a relatively high application value in the field of macromolecular encapsulation.

Description

Technical Field

[0001] The present invention relates to an amphiphilic tremella polysaccharide, a preparation method thereof and an application thereof. Background Art

[0002] The macromolecular encapsulation technology involves capturing various guests by macromolecular hosts, which has attracted much attention due to its wide applicability, easy operation and low cost. So far, various topological amphiphilic polymers, such as dendrimers, star polymers and hyperbranched polymers (HPs), have been applied to encapsulate different guests. Among them, compared with other amphiphilic polymers, amphiphilic HPs have a globular macromolecular structure, numerous internal cavities and surface functional groups, and their synthesis process is simple, making them more suitable for guest encapsulation. Although remarkable progress has been made in the development of amphiphilic HP hosts, all the reports have focused on non-biodegradable synthetic HPs, which have relatively high toxicity and cost. In contrast, natural HPs with good biocompatibility and low cost are more suitable as hosts. Among them, amphiphilic polysaccharides have attracted much attention from researchers due to their excellent properties and wide application fields.

[0003] The preparation of amphiphilic polysaccharides refers to amphiphilic products obtained by moderately hydrophobic modification of hydrophilic polysaccharides. The main ways of polysaccharide hydrophobization are as follows: (1) directly linking hydrophobic groups to the polysaccharide chain through functional groups on polysaccharide residues (such as -OH, -COOH, -NH2, etc.) (such as deoxycholic acid starch ester); (2) linking the polysaccharide chain and hydrophobic groups through reagent reaction with a specific linker arm to introduce hydrophobic groups into the polysaccharide molecule (such as hyaluronic acid-hydroxysuccinimide-quercetin); (3) for some polysaccharides with poor water solubility, first solubilize and modify the polysaccharides (such as aminating cellulose, carboxymethylating polysaccharides, etc.), and then hydrophobize them. However, there are still some deficiencies and limitations in the hydrophobic modification of hydrophilic polysaccharides in the prior art, and their application scope and scenarios are not comprehensive enough. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an amphiphilic tremella polysaccharide, a preparation method thereof and an application thereof in order to overcome the above problems. The preparation method of the present invention has a high yield, is safe and easy to operate. The preparation method hydrophobically modifies tremella polysaccharide to make it have a suitable degree of substitution of hydrophobic groups, so as to have the characteristics of amphiphilicity. It has both high water absorption and lipophilicity, can be used as a good surfactant, and can improve the solubility of fat-soluble functional raw materials and the encapsulation rate of some active substances, and has high application value in the field of macromolecular encapsulation.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] The present invention provides an amphiphilic tremella polysaccharide, which comprises a tremella polysaccharide modified with a hydrophobic group.

[0007] In the present invention, the chemical structural formula of the amphiphilic tremella polysaccharide can be expressed as (WSK)n-R, as shown in Formula 1, wherein WSK represents the structural unit of the tremella polysaccharide, n is the number of structural units, n>500, and R is H or the hydrophobic group.

[0008]

[0009] In the present invention, the hydrophobic group is preferably a cholesteryl succinate group.

[0010] In the present invention, the degree of substitution of the hydrophobic group is preferably 1-10%, such as 3.32%, 6.75%, 8.16%, 8.74% or 8.58%; the degree of substitution refers to the molar ratio of the number of hydrophobic groups to the number of structural units of the tremella polysaccharide in the amphiphilic tremella polysaccharide.

[0011] The present invention provides a preparation method of the amphiphilic tremella polysaccharide as described above, which comprises the following steps: mixing a tremella polysaccharide solution and an activation reaction solution and then reacting to obtain; wherein,

[0012] The tremella polysaccharide solution comprises a tremella polysaccharide and a solvent;

[0013] The activation reaction solution comprises a hydrophobe, a catalyst and a solvent.

[0014] In the present invention, the tremella polysaccharide (WSK) is a typical natural HP with a highly branched macromolecular chain. WSK is not only easily prepared from the abundant tremella resources in the world, but also has multiple internal cavities and oxygen-containing groups, which makes it have the excellent property of being a macromolecular host for convenient customized guest encapsulation.

[0015] In the present invention, the purity of the tremella polysaccharide is preferably above 95%.

[0016] In some preferred embodiments, the preparation method of the tremella polysaccharide comprises: carrying out an extraction reaction on tremella powder and water under heating and stirring, concentrating, alcohol precipitation, filtering, re-dissolving, and drying to obtain.

[0017] Among them, the mass ratio of the tremella powder to water is preferably 1:(30-50), such as 1:40.

[0018] Among them, the temperature of the extraction reaction is preferably 70-100°C, such as 90°C;

[0019] Among them, the time of the extraction reaction is preferably 1-4 h, such as 2 h.

[0020] In the present invention, the hydrophobic agent is preferably cholesteryl succinate.

[0021] In some preferred embodiments, the preparation method of cholesteryl succinate includes: reacting cholesteryl, succinic anhydride and pyridine at room temperature, precipitating with ice hydrochloric acid, filtering, washing, recrystallizing, and drying to obtain.

[0022] As one of the endogenous substances in the body, cholesteryl has the advantages of low toxicity, rich vitamins and antioxidants. Preparing it into cholesteryl succinate can effectively hydrophobically modify tremella polysaccharide.

[0023] In the present invention, the catalyst is preferably 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC·HCl) and / or triethylamine, more preferably 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and triethylamine.

[0024] In the present invention, the solvent is preferably an aprotic polar solvent, such as N,N-dimethylformamide (DMF) or dimethyl sulfoxide (DMSO).

[0025] In some preferred embodiments of the present invention, the hydrophobic agent is cholesteryl succinate, the catalyst is 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and triethylamine, and the molar ratio of cholesteryl succinate, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, and triethylamine is (3-12):57:25, such as 12:57:25.

[0026] In the present invention, the volume ratio of the tremella polysaccharide solution to the activation reaction solution is preferably (4-10):3, such as 2:1 or 1:1.

[0027] In the present invention, the temperature of the reaction is preferably 20-40°C, such as 25°C.

[0028] In the present invention, the reaction time is preferably 36-60 h, such as 40 h.

[0029] In the present invention, the mass concentration of the tremella polysaccharide solution is preferably 0.005-0.05 g / mL, such as 0.01 g / mL or 0.02 g / mL. Wherein, the mass concentration of the tremella polysaccharide solution refers to the mass of tremella polysaccharide in 1 mL of the tremella polysaccharide solution.

[0030] In the present invention, the mass concentration of the activation reaction solution is 0.01-0.08 g / mL, such as 0.0313 g / mL. Wherein, the mass concentration of the activation reaction solution refers to the sum of the masses of the hydrophobic agent and the catalyst in 1 mL of the activation reaction solution.

[0031] In the present invention, the preparation method of the activation reaction solution may include mixing and stirring the hydrophobic agent, the catalyst and the solvent, and the mixing and stirring time is preferably 1 to 4 h, such as 2 h.

[0032] When the hydrophobic agent is cholesteryl succinate, during the mixing and stirring process, the catalyst takes away the hydrogen on the carboxyl group of cholesteryl succinate, exposing the lone pair of electrons on the oxygen, so as to achieve the purpose of activation.

[0033] In the present invention, preferably, after the reaction, adding alcohol, standing, filtering and washing are further included.

[0034] In some preferred embodiments, adding alcohol means mixing the mixed reaction solution obtained from the reaction with an ethanol aqueous solution; wherein, the volume ratio of the mixed reaction solution to the ethanol aqueous solution is preferably 1:(2 - 8), such as 7:50, 3:5 or 13:50; the volume fraction of the ethanol aqueous solution is preferably 95%.

[0035] In some preferred embodiments, the standing time is 1 - 5 h, such as 4 h.

[0036] In some preferred embodiments, the filtering is suction filtration.

[0037] In some preferred embodiments, the washing includes washing with ethanol, tetrahydrofuran and ether respectively.

[0038] The present invention also provides the application of the above amphiphilic tremella polysaccharide in the field of macromolecular encapsulation.

[0039] In the present invention, the field of macromolecular encapsulation involves using macromolecular encapsulation technology in the preparation processes of cosmetics, drugs, etc. to improve the performance of cosmetics or drugs.

[0040] On the basis of conforming to the common knowledge in the art, the above preferred conditions can be combined arbitrarily to obtain various preferred examples of the present invention.

[0041] The reagents and raw materials used in the present invention are all commercially available.

[0042] The positive and progressive effects of the present invention are as follows:

[0043] (1) The preparation method of the amphiphilic tremella polysaccharide provided by the present invention is safe and easy to operate, and the yield of the obtained amphiphilic tremella polysaccharide is controllable. By changing the reaction conditions, the achievable yield is 30% - 80%.

[0044] (2) The amphiphilic tremella polysaccharide prepared by the present invention has a suitable degree of substitution of hydrophobic groups (the degree of substitution can be 1% - 10%), thus having the characteristics of amphiphilicity, both high water absorption and lipophilicity, and can be used as a good surfactant. At the same time, it can improve the solubility of fat-soluble functional raw materials and the encapsulation rate of some active substances. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a process diagram for the preparation of the amphiphilic tremella polysaccharide of the present invention.

[0046] Figure 2 It is an infrared analysis diagram of the tremella polysaccharide in Example 3 of the present invention.

[0047] Figure 3 It is an infrared analysis diagram of the amphiphilic tremella polysaccharide in Example 3 of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0048] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0049] The preparation processes of the amphiphilic tremella polysaccharides in the following Examples 1 - 5 are as Figure 1 shown, wherein the synthesis route of the amphiphilic tremella polysaccharide is as shown in Formula 2:

[0050]

[0051] Example 1

[0052] Mix tremella powder and water in a ratio of 1:40, stir in a water bath at 90 °C, stop stirring after 2 h, filter to obtain a filtrate, extract with water again, combine the two aqueous solutions, rotary evaporate and concentrate to one-third of the volume, cool to room temperature, add three times the volume of absolute ethanol for alcohol precipitation, let stand overnight, collect the precipitate, redissolve, and dry to obtain a powder.

[0053] Put 5 g of cholesterol and 5 g of succinic anhydride into a reaction flask, dissolve with dehydrated pyridine, and react at room temperature for 48 h. After the reaction at room temperature, terminate the reaction, drop the reaction solution into an ice hydrochloric acid solution with pH = 1 - 2, and a white flocculent precipitate will precipitate. Refrigerate overnight, filter by suction, and collect the precipitate. Wash the precipitate with distilled water until pH > 5, recrystallize in ethyl acetate / ethanol, and dry at 80 °C to obtain a pure white needle-like cholesterol succinate product.

[0054] Take 0.20 g of tremella polysaccharide sample and dissolve it in 40 mL of N,N-dimethylformamide for standby. Separately, take 0.03 g of cholesteryl succinate, 0.57 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, and 0.25 g of triethylamine, dissolve them in 30 mL of DMF, stir at room temperature, and react and activate for 2 h; add the activated reaction solution to the tremella polysaccharide solution, react for 40 h, stop the reaction, add the reaction solution to 500 mL of 95% ethanol, let it stand for 4 h, filter by suction, and wash the precipitate with ethanol, tetrahydrofuran, and ether respectively. Dry the precipitate to obtain amphiphilic tremella polysaccharide.

[0055] Example 2

[0056] Mix tremella powder and water in a ratio of 1:30, stir in a water bath at 90 °C, stop stirring after 2 h, filter to obtain the filtrate, extract with water again once, combine the two aqueous solutions, rotary evaporate and concentrate to one-third of the volume, cool to room temperature, add three times the volume of absolute ethanol for alcohol precipitation, let it stand overnight, collect the precipitate, redissolve, and dry to obtain the powder.

[0057] Put 10 g of cholesterol and 10 g of succinic anhydride into a reaction flask, add dehydrated pyridine to dissolve, and react at room temperature for 48 h. After the reaction at room temperature, terminate the reaction, drop the reaction solution into an ice hydrochloric acid solution with pH = 1 - 2, and a white flocculent precipitate will precipitate. Refrigerate overnight, filter by suction, and collect the precipitate. Wash the precipitate with distilled water until pH > 5, recrystallize in ethyl acetate / ethanol, and dry at 80 °C to obtain pure white needle-shaped cholesteryl succinate.

[0058] Take 0.50 g of tremella polysaccharide sample and dissolve it in 100 mL of N,N-dimethylformamide for standby. Separately, take 0.075 g of cholesteryl succinate, 1.425 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, and 0.625 g of triethylamine, dissolve them in 30 mL of DMF, stir at room temperature, and react and activate for 2 h; add the activated reaction solution to the tremella polysaccharide solution, react for 40 h, stop the reaction, add the reaction solution to 500 mL of 95% ethanol, let it stand for 4 h, filter by suction, and wash the precipitate with ethanol, tetrahydrofuran, and ether respectively. Dry the precipitate to obtain amphiphilic tremella polysaccharide.

[0059] Example 3

[0060] Mix tremella powder and water in a ratio of 1:40, stir in a water bath at 90 °C, stop stirring after 2 h, filter to obtain the filtrate, extract with water again once, combine the two aqueous solutions, rotary evaporate and concentrate to one-third of the volume, cool to room temperature, add three times the volume of absolute ethanol for alcohol precipitation, let it stand overnight, collect the precipitate, redissolve, and dry to obtain the powder.

[0061] Place 5 g of cholesterol and 5 g of succinic anhydride in a reaction flask, add anhydrous pyridine to dissolve, and react at room temperature for 48 h. After the reaction at room temperature, terminate the reaction. Drop the reaction solution into an ice hydrochloric acid solution with pH = 1 - 2 to precipitate a white flocculent precipitate. Refrigerate overnight, filter by suction, and collect the precipitate. Wash the precipitate with distilled water until pH > 5, recrystallize in ethyl acetate / ethanol, and dry at 80 °C to obtain pure white needle-shaped cholesteryl succinate.

[0062] Take 1.0 g of tremella polysaccharide sample and dissolve it in 100 mL of N, N-dimethylformamide for standby. Separately, take 0.12 g of cholesteryl succinate, 0.57 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, and 0.25 g of triethylamine, dissolve them in 50 mL of DMF, stir at room temperature, and react and activate for 2 h; add the activated reaction solution to the tremella polysaccharide solution, react for 40 h, stop the reaction, add the reaction solution to 500 mL of 95% ethanol, let it stand for 4 h, filter by suction, and wash the precipitate with ethanol, tetrahydrofuran, and ether respectively. Dry the precipitate to obtain amphiphilic tremella polysaccharide.

[0063] Example 4

[0064] Mix tremella powder and water in a ratio of 1:50, stir in a water bath at 90 °C, stop stirring after 2 h, filter to obtain the filtrate, extract with water again once, combine the two aqueous solutions, rotary evaporate and concentrate to one-third of the volume, cool to room temperature, add three times the volume of anhydrous ethanol for alcohol precipitation, let it stand overnight, collect the precipitate, redissolve, and dry to obtain a powder.

[0065] Place 5 g of cholesterol and 5 g of succinic anhydride in a reaction flask, add anhydrous pyridine to dissolve, and react at room temperature for 48 h. After the reaction at room temperature, terminate the reaction. Drop the reaction solution into an ice hydrochloric acid solution with pH = 1 - 2 to precipitate a white flocculent precipitate. Refrigerate overnight, filter by suction, and collect the precipitate. Wash the precipitate with distilled water until pH > 5, recrystallize in ethyl acetate / ethanol, and dry at 80 °C to obtain pure white needle-shaped cholesteryl succinate.

[0066] Take 2.0 g of tremella polysaccharide sample and dissolve it in 100 mL of N, N-dimethylformamide for standby. Separately, take 0.12 g of cholesteryl succinate, 0.57 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, and 0.25 g of triethylamine, dissolve them in 30 mL of DMF, stir at room temperature, and react and activate for 2 h; add the activated reaction solution to the tremella polysaccharide solution, react for 40 h, stop the reaction, add the reaction solution to 500 mL of 95% ethanol, let it stand for 4 h, filter by suction, and wash the precipitate with ethanol, tetrahydrofuran, and ether respectively. Dry the precipitate to obtain amphiphilic tremella polysaccharide.

[0067] Example 5

[0068] Mix tremella powder and water in a ratio of 1:40, stir in a water bath at 90 °C, stop stirring after 2 h, filter to obtain a filtrate, extract with water again, combine the two aqueous solutions, rotary evaporate and concentrate to one-third of the volume, cool to room temperature, add three times the volume of absolute ethanol for alcohol precipitation, let stand overnight, collect the precipitate, redissolve, and dry to obtain a powder.

[0069] Put 5 g of cholesterol and 5 g of succinic anhydride into a reaction flask, dissolve with dehydrated pyridine, and react at room temperature for 48 h. After the reaction at room temperature, terminate the reaction, drop the reaction solution into an ice hydrochloric acid solution with pH = 1-2, and a white flocculent precipitate will form. Refrigerate overnight, filter by suction, and collect the precipitate. Wash the precipitate with distilled water until pH > 5, recrystallize in ethyl acetate / ethanol, and dry at 80 °C to obtain pure white needle-shaped cholesterol succinate.

[0070] Take 5.0 g of tremella polysaccharide sample and dissolve it in 100 mL of N,N-dimethylformamide for standby. Take another 0.12 g of cholesterol succinate, 0.57 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, and 0.25 g of triethylamine, dissolve them in 30 mL of DMF, stir at room temperature, and react for 2 h for activation; add the activated reaction solution to the tremella polysaccharide solution, react for 40 h, stop the reaction, add the reaction solution to 500 mL of 95% ethanol, let stand for 4 h, filter by suction, and wash the precipitate with ethanol, tetrahydrofuran, and ether respectively. Dry the precipitate to obtain amphiphilic tremella polysaccharide.

[0071] Effect examples

[0072] (1) Degree of substitution test of cholesterol succinate

[0073] ① Test method

[0074] The present invention uses the ammonium ferric sulfate colorimetric method to determine the degree of substitution of cholesterol succinate.

[0075] ② Test results

[0076]

[0077] (2) Infrared test of amphiphilic tremella polysaccharide

[0078] ① Test method

[0079] The present invention uses a Fourier transform infrared spectrophotometer to perform an infrared test on the amphiphilic tremella polysaccharide prepared in the present invention, that is, cholesterol succinate tremella polysaccharide.

[0080] ② Test results

[0081] From Figure 2 and Figure 3 Analysis shows that the cholesterol succinate tremella polysaccharide sample is at about 3262 cm-1 There is a strong absorption peak of O-H stretching vibration at this position, indicating the presence of a large amount of O-H; a new absorption peak appears at 1651 cm -1 of the sample, indicating acyl modification; compared with the infrared spectrum of Tremella polysaccharide, the absorption peaks at 1651 cm -1 and 1020 cm -1 of the sample are significantly enhanced, and these two positions are the characteristic absorption peaks of C=O and C-O-C of succinyl groups. The above results indicate that cholesteryl succinyl groups are successfully linked to the Tremella polysaccharide backbone.

[0082] (3) Yield of amphiphilic Tremella polysaccharide

[0083] ① Testing method

[0084] Yield of amphiphilic Tremella polysaccharide (cholesteryl succinate Tremella polysaccharide) = mass of product (g) / mass of feedstock (g)

[0085] ② Testing results

[0086]

[0087] (4) Determination of oil-water partition coefficient (P)

[0088] ① Testing method

[0089] Take 10 mL each of a solution containing a certain amount of amphiphilic Tremella polysaccharide (concentration C0) and n-octanol solution saturated with water and put them into a conical flask. Vortex and oscillate at a certain intensity for 24 h. After standing for 15 min, the two phases are separated. Separate the aqueous phase, centrifuge the aqueous phase at a speed of 3000 r·min -1 for 10 min, and use high performance liquid chromatography (HPLC) method to determine the concentration of amphiphilic Tremella polysaccharide in the aqueous phase after phase separation and record it as C W , then the concentration of amphiphilic Tremella polysaccharide in the oil phase after phase separation is C0 - C W , and P = (C0 - C W ) / C W .

[0090] ② Testing results

[0091] Log P = 0.5, which indicates that the product prepared by the present invention has amphiphilicity.

[0092] The preparation method of the amphiphilic Tremella polysaccharide provided by the present invention is safe and easy to operate. The obtained amphiphilic Tremella polysaccharide has both high water absorbency and lipophilicity, and has extremely high application value in the field of macromolecular encapsulation.

Claims

1. An amphiphilic tremella polysaccharide, characterized in that, It includes tremella polysaccharide modified with a hydrophobic group.

2. The amphiphilic tremella polysaccharide according to claim 1, wherein The chemical structural formula of the amphiphilic tremella polysaccharide is (WSK)n-R, as shown in Formula 1, where WSK represents the structural unit of tremella polysaccharide, n is the number of structural units, n > 500, and R is H or the hydrophobic group; and / or, the hydrophobic group is a cholesteryl succinate group; and / or, the degree of substitution of the hydrophobic group is 1-10%, such as 3.32%, 6.75%, 8.16%, 8.74% or 8.58%.

3. A preparation method of the amphiphilic tremella polysaccharide as described in claim 1 or 2, characterized in that, It includes the following steps: Mix the tremella polysaccharide solution and the activation reaction solution and then carry out the reaction to obtain it; where, the tremella polysaccharide solution includes tremella polysaccharide and a solvent; the activation reaction solution includes a hydrophobizing agent, a catalyst and a solvent.

4. The preparation method of tremella polysaccharide according to claim 3, wherein, The hydrophobizing agent is cholesteryl succinate; and / or, the catalyst is 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and / or triethylamine, preferably 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and triethylamine; and / or, the solvent is an aprotic polar solvent, such as N,N-dimethylformamide or dimethyl sulfoxide.

5. The preparation method of tremella polysaccharide according to claim 4, wherein, The hydrophobizing agent is cholesteryl succinate, the catalyst is 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and triethylamine, and the molar ratio of the cholesteryl succinate, the 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, and the triethylamine is (3-12):57:25, such as 12:57:

25.

6. The preparation method of tremella polysaccharide according to claim 3, characterized in that The volume ratio of the tremella polysaccharide solution to the activation reaction solution is (4-10):3, such as 2:1 or 1:1; and / or, the temperature of the reaction is 20-40°C, such as 25°C; and / or, the time of the reaction is 36-60 h, such as 40 h; and / or, the mass concentration of the tremella polysaccharide solution is 0.005-0.05 g / mL, such as 0.01 g / mL or 0.02 g / mL; and / or, the mass concentration of the activation reaction solution is 0.01-0.08 g / mL, such as 0.0313 g / mL; and / or, the preparation method of the activation reaction solution includes mixing and stirring the hydrophobizing agent, the catalyst and the solvent, and the mixing and stirring time is preferably 1-4 h, such as 2 h.

7. The preparation method of tremella polysaccharide according to claim 3, characterized in that, After the reaction, it also includes adding alcohol, standing, filtering and washing; Preferably, adding alcohol means mixing the obtained mixed reaction solution with an ethanol aqueous solution; where, the volume ratio of the mixed reaction solution to the ethanol aqueous solution is preferably 1:(2-8), such as 7:50, 3:5 or 13:50; the volume fraction of the ethanol aqueous solution is preferably 95%; Preferably, the standing time is 1-5 h, such as 4 h; Preferably, the filtering is suction filtration; Preferably, the washing includes washing with ethanol, tetrahydrofuran and ether respectively.

8. The preparation method of tremella polysaccharide according to claim 3, characterized in that, The purity of the tremella polysaccharide is above 95%; and / or, the preparation method of the tremella polysaccharide includes: carrying out an extraction reaction on tremella powder and water under heating and stirring, concentrating, alcohol precipitation, filtering, redissolving, and drying to obtain it; Among them, the mass ratio of the tremella powder to water is preferably 1:(30-50), such as 1:40; Among them, the temperature of the extraction reaction is preferably 70-100 °C, such as 90 °C; Among them, the time of the extraction reaction is preferably 1-4 h, such as 2 h.

9. The preparation method of tremella polysaccharide according to claim 4, characterized in that, The preparation method of the cholesteryl succinate includes: reacting cholesteryl, succinic anhydride and pyridine at room temperature, precipitating with ice hydrochloric acid, filtering, washing, recrystallizing, and drying to obtain.

10. Use of an amphiphilic tremella polysaccharide as described in claim 1 or 2 in the field of macromolecular encapsulation.

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