Method for preparing glycosylglycerol by chemical method

Abstract

The invention belongs to the technical field of preparation and application of surfactants, and particularly relates to a method for preparing glycosylglycerol by a chemical method. Glycerol and glucose are used as raw materials, and aldolization is performed under the condition of an acid catalyst to prepare the glycosylglycerol. According to the method for preparing the glycosylglycerol product, the reaction is homogeneous reaction, the reaction is low in time consumption and energy consumption, the content of residual sugar is low, the sugar conversion rate is high, the cost is low, and the method is suitable for large-scale production.

Description

Technical Field

[0001] The invention relates to the technical field of surfactant preparation and application, and in particular to a method for preparing glycerol glucoside by a chemical method. Background Art

[0002] Glucosylglycerol (GG) is a glycoside compound formed by the glycosidic bond between glucose and glycerol. As a polyhydroxy compound, glycerol glucoside has attracted extensive attention due to its wide application potential in industry and its easy conversion. In nature, many moderately salt-tolerant cyanobacteria produce glycerol glucoside as a compatible solute in a salt-dependent manner. In addition, some higher plants and fermentation processes can also synthesize this substance. However, the current synthesis methods have problems such as low yield, high cost, production of by-products, and environmental unfriendliness.

[0003] At present, GG can be synthesized by enzyme-catalyzed synthesis and synthetic biology. Synthetic biology can produce structurally specific GG products, but biosynthesis is difficult to industrialize for the time being due to high production costs and low product yields, and is mostly in its infancy. The advantages of enzyme-catalyzed reactions are high specificity and high catalytic rate. However, enzyme catalysis has limitations. Enzymes are very fragile and easily inactivated. Enzymes have high specificity, and one enzyme only catalyzes one or one type of substrate, which has low applicability and has the disadvantages of by-product generation.

[0004] Therefore, it is necessary to study a method for synthesizing glycerol glucoside that is simple to operate, high in yield, low in cost, and environmentally friendly to address the deficiencies of the prior art and to solve or alleviate one or more of the above problems. Summary of the invention

[0005] The purpose of the present invention is to provide a method for preparing glycerol glucoside by a chemical method to solve the problems existing in the above-mentioned prior art, and the synthesized glycerol glucoside has a lower residual sugar content, a higher sugar conversion rate and better moisturizing performance.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] One of the technical solutions of the present invention is to provide a method for preparing glycerol glucoside by chemical method, the steps comprising:

[0008] Glycerol and glucose are used as raw materials after dehydration, and the glycerol glucoside is prepared by acetalization reaction under the condition of an acidic catalyst;

[0009] The acidic catalyst includes p-toluenesulfonic acid, methanesulfonic acid or concentrated sulfuric acid.

[0010] Furthermore, the amount of the acidic catalyst used is 0.5% to 3% of the mass of the raw material.

[0011] Furthermore, the molar ratio of glycerol to glucose is (1-3):1.

[0012] Furthermore, the parameters of the acetalization reaction are as follows: temperature 70-120° C., vacuum pressure 0-5 mm Hg, reaction time 1.5-10 h, and stirring rate 200-600 rpm.

[0013] Further, the step of removing water comprises:

[0014] After the glycerol and glucose are mixed, they are stirred at a speed of 200 to 600 rpm for 30 to 100 minutes under the conditions of a temperature of 50 to 100° C. and a pressure of 0 to 5 mm Hg.

[0015] The second technical solution of the present invention is to provide a glycerol glucoside prepared by the above method.

[0016] The third technical solution of the present invention is to provide the use of the above-mentioned glycerol glucoside or the glycerol glucoside prepared by the above-mentioned method as a moisturizing ingredient in daily chemical products.

[0017] Technical solution 4 of the present invention: Provided is a method for improving the sugar conversion rate when preparing glycerol glucoside from glycerol and glucose, the steps comprising:

[0018] Using glycerol and glucose as raw materials, the glycerol glucoside is prepared by acetalization reaction under the catalytic condition of an acidic catalyst;

[0019] The acidic catalyst includes p-toluenesulfonic acid, methanesulfonic acid or concentrated sulfuric acid.

[0020] When glycerol glucoside is prepared from glycerol and glucose by the method of the present invention, the sugar conversion rate can reach 99.1%.

[0021] A fifth technical solution of the present invention is to provide a method for reducing the residual sugar content when preparing glycerol glucoside from glycerol and glucose, the steps comprising:

[0022] Using glycerol and glucose as raw materials, the glycerol glucoside is prepared by acetalization reaction under the catalytic condition of an acidic catalyst;

[0023] The acidic catalyst includes p-toluenesulfonic acid, methanesulfonic acid or concentrated sulfuric acid.

[0024] When glycerol glucoside is prepared from glycerol and glucose by the method of the present invention, the residual sugar content can be as low as 0.43%.

[0025] The present invention discloses the following technical effects:

[0026] The method of the present invention prepares glycerol glucoside products, the reaction is a homogeneous reaction, the reaction time and energy consumption are low, the residual sugar content is low, the sugar conversion rate is high, the cost is low, and it is suitable for large-scale production.

[0027] In the reaction process of the present invention, no solvent is added, the post-processing steps of the product are reduced, and the preparation method is more environmentally friendly.

[0028] The present invention uses glycerol and glucose as raw materials, and under the condition of an acidic catalyst, the glycerol glucoside prepared by acetalization reaction has better moisturizing performance than glycerol and glycerol glucoside prepared by biological methods, because the residual sugar content in the glycerol glucoside prepared by the chemical method is lower. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 The residual sugar content and sugar conversion rate of the products obtained at different acetal reaction times in Examples 1 to 5;

[0031] Figure 2 The residual sugar content and sugar conversion rate of the products obtained by using different material ratios of glycerol and glucose in Examples 1 and Examples 6 to 8;

[0032] Figure 3 The residual sugar content and sugar conversion rate of the products obtained by adding different amounts of acidic catalysts in Examples 9 to 11;

[0033] Figure 4 The moisturizing properties at different times after treatment with Example 1, Comparative Example 1, glycerol and water;

[0034] Figure 5 It is a liquid chromatogram of a mixed standard sample of glycerol, glucose and glycerol glucoside;

[0035] Figure 6 It is the liquid chromatogram of the chemically synthesized product glycerol glucoside;

[0036] Figure 7 This is a physical picture of the products prepared in Example 1 and Comparative Example 2. DETAILED DESCRIPTION

[0037] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0038] It should be understood that the terms described in the present invention are only for describing a particular embodiment and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0039] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0040] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to those skilled in the art. The present invention description and examples are exemplary only.

[0041] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0042] The raw materials and reagents used in the specific embodiments of the present invention are all commercially available products.

[0043] Example 1

[0044] The steps of preparing glycerol glucoside by chemical method include:

[0045] S1. At room temperature, glycerol and glucose in a molar ratio of 2.3:1 were fully mixed, and stirred at a speed of 350 rpm for 30 min at a temperature of 60° C. and a pressure of 1.5 mm Hg to obtain a pre-treated reactant after effluent;

[0046] S2, adding an acidic catalyst (p-toluenesulfonic acid) to the pretreated reactant, and then reacting at 90° C. and 1.5 mm Hg pressure for 10 h, maintaining a stirring rate of 350 rpm during the reaction, to obtain glycerol glucoside;

[0047] The amount of the acid catalyst added is 1% of the mass of the pre-treated reactants.

[0048] Example 2

[0049] Compared with Example 1, the only difference is that the reaction time of step S2 is 9 hours.

[0050] Example 3

[0051] Compared with Example 1, the only difference is that the reaction time of step S2 is 5 hours.

[0052] Example 4

[0053] Compared with Example 1, the only difference is that the reaction time of step S2 is 2.5 h.

[0054] Example 5

[0055] Compared with Example 1, the only difference is that the reaction time of step S2 is 1.5 h.

[0056] Example 6

[0057] Compared with Example 1, the only difference is that the material ratio of glycerol to glucose in step S1 is 2:1.

[0058] Example 7

[0059] Compared with Example 1, the only difference is that the material ratio of glycerol to glucose in step S1 is 1.7:1.

[0060] Example 8

[0061] Compared with Example 1, the only difference is that the material ratio of glycerol to glucose in step S1 is 1.3:1.

[0062] Example 9

[0063] Compared with Example 1, the only difference is that the amount of the acid catalyst added is 2.0% of the amount of the pre-treated reactants.

[0064] Example 10

[0065] Compared with Example 1, the only difference is that the amount of the acid catalyst added is 1.5% of the amount of the pre-treated reactants.

[0066] Embodiment 11

[0067] Compared with Example 1, the only difference is that the amount of the acid catalyst added is 0.5% of the amount of the pre-treated reactants.

[0068] The products prepared in Examples 1 to 11 were tested for residual sugar content and sugar conversion rate as follows:

[0069] Take 3g of the product after the reaction, add water to make the volume to 100mL; take Fehling's reagent in a 250mL conical flask, place the conical flask on a heating mantle and heat it to boiling, add the reactant solution dropwise until the solution fades from blue to form a brick-red precipitate, then stop adding, calculate the residual sugar content in the product according to the amount of reactant solution added (Formula 1), calculate the sugar conversion rate in the reaction according to the measured residual sugar content (Formula 2), and the results are as follows: Figures 1 to 3 shown.

[0070]

[0071] Where:

[0072] V1 is the volume of glucose standard solution consumed to calibrate 10 ml of alkaline copper tartrate solution, in milliliters (mL);

[0073] v2 is the average volume of the sample solution consumed during the measurement, in milliliters (mL);

[0074] msample is the weight of the sample, in g;

[0075] X is the residual sugar content.

[0076]

[0077] Where:

[0078] X is the residual sugar content;

[0079] M is the total mass of the reactants, in (g);

[0080] W is the amount of glucose fed, in g.

[0081] Figure 1 The residual sugar content and sugar conversion rate of the products obtained at different acetal reaction times in Examples 1 to 5; Figure 2 The residual sugar content and sugar conversion rate of the products obtained by using different material ratios of glycerol and glucose in Examples 1 and Examples 6 to 8; Figure 3 The residual sugar content and sugar conversion rate of the products obtained by adding different amounts of acidic catalysts in Example 1 and Examples 9 to 11. Figures 1 to 3 It can be seen that the reaction time, material ratio and the amount of acidic catalyst added have an impact on the residual sugar content and sugar conversion rate of the product. Among them, the longer the reaction time, the lower the residual sugar content and the higher the sugar conversion rate; the larger the material ratio, the lower the residual sugar content and the higher the sugar conversion rate; the excessively high catalyst concentration in the reaction system accelerates the speed of the positive reaction, making the speed of water generation greater than the speed of water removal. Unreacted glucose will absorb water, making it easy for glucose to polymerize into viscous polysaccharides, resulting in a decrease in glucose conversion rate.

[0082] Comparative Example 1

[0083] Take the glycerol glucoside product prepared by biological method as a comparative example:

[0084] Using glycerol and sucrose as substrates, sucrose phosphorylase is used to catalyze the reaction of the substrates to obtain a product containing glycerol glucoside;

[0085] The mass ratio of glycerol to sucrose was 1:1, the amount of sucrose phosphorylase used was 4 U / mL of the substrate mass, the reaction temperature was 80° C., the reaction time was 8 h, and the pH was 6.5.

[0086] Comparative Example 2

[0087] Compared with Example 1, the only difference is that glycerol and glucose are not pretreated to remove water, and the preparation steps are as follows:

[0088] Glycerol and glucose were fully mixed, and then an acid catalyst was added, and then the mixture was reacted at 90° C. and 1.5 mm Hg pressure for 10 h, and the stirring rate was maintained at 350 rpm during the reaction to obtain a reaction product;

[0089] The amount of the acid catalyst added is 1% of the sum of the mass of glycerol and glucose; the material ratio of glycerol to glucose is 2.3:1.

[0090] The moisturizing properties of the glycerol glucoside of Example 1 and commercially available glycerol glucoside were investigated. The moisturizing performance test method was as follows: 10 g of distilled water, 10% glycerol, 10 g of glycerol glucoside aqueous solution by the biological method (Comparative Example 1) and the chemical method (Example 1) were weighed respectively, and placed in a 70×35 mm weighing bottle, which was placed in a constant temperature and humidity chamber (temperature of 20°C, relative humidity of 34%), and the water loss rate of the test samples was weighed and calculated over time at 1, 2, 3, 4, 6, 8, 10, and 12 hours.

[0091] The test results are shown in Table 1 and Figure 4 shown.

[0092] Table 1 Moisture Retention / %

[0093] time <![CDATA[H 2 The]]> glycerin Biological method Chemical method 1h 92.89 94.00 94.89 95.78 2h 89.00 89.00 89.67 91.33 3h 84.90 86.33 85.00 88.00 4h 78.40 79.89 79.33 83.89 6h 66.90 69.33 70.11 75.78 8h 60.60 59.89 62.00 64.67 10h 51.70 51.78 50.56 52.00 12h 44.10 43.89 42.11 46.11

[0094] Figure 4 Moisturizing performance at different times.

[0095] From Table 1 and Figure 4 It can be seen that the glycerol glucoside synthesized by chemical method in the present invention has excellent moisturizing properties at different times compared with commercial products, glycerol and water.

[0096] Figure 5 It is a liquid chromatogram of a mixed standard sample of glycerol, glucose and glycerol glucoside; Figure 6This is the liquid chromatogram of the chemically synthesized product glycerol glucoside in Example 1, Figures 5-6 In the study, the successful preparation of glycerol glucoside was demonstrated.

[0097] Figure 7 The actual picture of the products prepared in Example 1 and Comparative Example 2 (in the picture, the product without water removal is Example 1, and the product without water removal is Comparative Example 2). It can be seen from the picture that in Comparative Example 2, due to the lack of the water removal process for the reactants, the presence of water affects the reaction progress, making it difficult for the acetal reaction of glycerol and anhydrous glucose to proceed forward, but promoting the self-polymerization of glucose, making the color of the product darker.

[0098] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for preparing glycerol glucoside by chemical method, characterized in that the steps include: Glycerol and glucose are used as raw materials after dehydration, and the glycerol glucoside is prepared by acetalization reaction under the catalytic condition of an acidic catalyst; The acidic catalyst includes p-toluenesulfonic acid, methanesulfonic acid or concentrated sulfuric acid.

2. The method according to claim 1, characterized in that The amount of the acid catalyst used is 0.5% to 3% of the mass of the raw material.

3. The method according to claim 1, characterized in that The molar ratio of glycerol to glucose is (1-3):

1.

4. The method according to claim 1, characterized in that The parameters of the acetalization reaction are as follows: temperature of 70-120° C., vacuum pressure of 0-5 mm Hg, reaction time of 1.5-10 h, and stirring rate of 200-600 rpm.

5. The method according to claim 1, characterized in that Before the reaction, water must be removed, and the steps include: After the glycerol and glucose are mixed, they are stirred at a speed of 200 to 600 rpm for 30 to 100 minutes at a temperature of 50 to 100° C. and a pressure of 0 to 5 mm Hg to remove water, and then reacted to obtain the glycerol glucoside.

6. Glycerol glucoside obtained by the method according to any one of claims 1 to 5.

7. Use of the glycerol glucoside according to claim 6 or the glycerol glucoside prepared by the method according to any one of claims 1 to 5 as a moisturizing ingredient in daily chemical products.

8. A method for improving the sugar conversion rate when preparing glycerol glucoside from glycerol and glucose, characterized in that the steps include: Using glycerol and glucose as raw materials, the glycerol glucoside is prepared by acetalization reaction under the catalytic condition of an acidic catalyst; The acidic catalyst includes p-toluenesulfonic acid, methanesulfonic acid or concentrated sulfuric acid.

9. A method for reducing the residual sugar content when preparing glycerol glucoside from glycerol and glucose, characterized in that the steps include: Using glycerol and glucose as raw materials, the glycerol glucoside is prepared by acetalization reaction under the catalytic condition of an acidic catalyst; The acidic catalyst includes p-toluenesulfonic acid, methanesulfonic acid or concentrated sulfuric acid.

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