Glucose-1-O-fatty acid ester as well as preparation method and application thereof

Abstract

The invention discloses glucose-1-O-fatty acid ester and a preparation method and application thereof, and relates to the technical field of surfactants, the preparation method comprises the following steps: placing gluconic acid delta-lactone in tetrahydrofuran, adding N-methylmorpholine and trimethylchlorosilane, reacting at room temperature, washing an organic phase, drying, and concentrating to obtain 2, 3, 4, 5-trimethyl-1-O-fatty acid ester. 2, 6-tetra-O-trimethylsilyl gluconic acid delta-lactone is used as a raw material; dissolving the prepared lactone in methanol, adding calcium chloride and sodium borohydride, reacting at room temperature, evaporating to remove a solvent, and washing, drying and concentrating an organic phase to obtain 2, 3, 4, 6-tetra-O-trimethylsilyl glucose; placing the prepared glucose in dichloromethane, adding triethylamine and fatty acyl chloride, reacting at room temperature, and washing, drying and concentrating an organic phase to obtain 2, 3, 4, 6-tetra-O-trimethylsilyl glucose-1-O-fatty acid ester; and putting the prepared fatty acid ester into a methanol solution containing hydrochloric acid, reacting at room temperature, and concentrating the reaction solution to obtain the glucose-1-O-fatty acid ester. The yield is high, and all esters are monoesters.

Description

Technical Field

[0001] This invention relates to the field of surfactant technology, specifically to a glucose-1-O-fatty acid ester, its preparation method, and its application. Background Technology

[0002] One of the processes in reconstituted tobacco production involves concentrating the separated tobacco extract and then recoating it onto the paper-made substrate. The concentrate's main component is sugars, with a concentration exceeding 40%. Its high viscosity makes it difficult for the extract to penetrate the substrate effectively during coating, affecting the coating rate and uniformity. Although commercially available penetrants can improve the penetrability of the coating solution, these are non-tobacco additives and do not comply with regulations. Sugar esters, on the other hand, are permitted additives in tobacco products and comply with regulations.

[0003] Glucose fatty acid esters are novel nonionic surfactants that are nontoxic, low-irritant, and easily degradable. Currently, the literature reports two main synthetic methods for glucose fatty acid esters. The first method involves the direct reaction of glucose with fatty acids or fatty acid methyl esters. This method utilizes bases or enzymes as catalysts, offering the advantage of fewer reaction steps. However, its limitations include low product yields or the presence of significant amounts of diesters or polyesters in the product, making separation difficult. The second method uses tetrabenzyl glucose as a raw material, synthesizing glucose fatty acid esters through esterification and debenzylation reactions. This method yields a single compound, but its limitations include the high cost of tetrabenzyl glucose and the expensive palladium-carbon catalyst, leading to high production costs. These limitations result in the difficulty of industrial-scale production of glucose fatty acid esters, despite their numerous advantages as nonionic surfactants, and the lack of commercially available reagents.

[0004] Therefore, current glucose fatty acid esters suffer from problems such as low product yield, the presence of impurities that are difficult to separate, or high production costs. Summary of the Invention

[0005] Given the problem that current glucose fatty acid esters contain impurities that are difficult to separate, the present invention aims to provide a glucose-1-O-fatty acid ester, its preparation method, and its application. The glucose-1-O-fatty acid esters prepared by this method have a high yield and are all monoesters without polyester byproducts. Moreover, the raw materials are inexpensive, the reaction process is simple, and when applied to coating solutions, it improves the permeability of the coating solution in the substrate, thereby improving the coating rate and coating uniformity.

[0006] This invention is achieved through the following technical solution:

[0007] In a first aspect, this application provides a method for preparing glucose-1-O-fatty acid esters, comprising the following steps:

[0008] δ-gluconolactone was placed in tetrahydrofuran, and then N-methylmorpholine and trimethylchlorosilane were added. The reaction was completed at room temperature. The organic phase was washed, dried and concentrated to obtain 2,3,4,6-tetra-O-trimethylsilylgluconolactone.

[0009] 2,3,4,6-tetra-O-trimethylsilylglucanol δ-lactone was dissolved in methanol, and then calcium chloride and sodium borohydride were added. After the reaction was completed at room temperature, the solvent was evaporated. The organic phase was washed, dried and concentrated to obtain 2,3,4,6-tetra-O-trimethylsilylglucose.

[0010] 2,3,4,6-tetra-O-trimethylsilylglucose was placed in dichloromethane, and then triethylamine and fatty acyl chloride were added. The reaction was completed at room temperature. The organic phase was washed, dried and concentrated to obtain 2,3,4,6-tetra-O-trimethylsilylglucose-1-O-fatty acid ester.

[0011] 2,3,4,6-tetra-O-trimethylsilylglucose-1-O-fatty acid ester was placed in a methanol solution containing hydrochloric acid and reacted completely at room temperature. The reaction solution was then concentrated to obtain glucose-1-O-fatty acid ester.

[0012] This invention uses gluconate δ-lactone as a raw material, and obtains the target product through a four-step reaction involving TMS protection, reduction, esterification, and deprotection. The raw materials are inexpensive and all are conventional reagents. The reaction process is simple, requiring no pressure heating or column chromatography. The product yield is high, and all products are monoesters with no polyester byproducts. Furthermore, adding this glucose-1-O-fatty acid ester to the reconstituted tobacco coating solution can improve the permeability of the coating solution, increase the coating rate, and improve the coating uniformity.

[0013] In one specific embodiment, the structural formula of the 2,3,4,6-tetra-O-trimethylsilylgluconate δ-lactone is:

[0014] ;

[0015] TMS stands for trimethylsilane.

[0016] In one specific embodiment, the structural formula of the 2,3,4,6-tetra-O-trimethylsilylglucose is:

[0017] ;

[0018] TMS stands for trimethylsilane.

[0019] In one specific embodiment, the structural formula of the 2,3,4,6-tetra-O-trimethylsilylglucose-1-O-fatty acid ester is:

[0020] ;

[0021] Wherein, TMS is trimethylsilane; R is a straight-chain alkyl group with carbon chain numbers of 9, 11, 13, 15 and 17.

[0022] In one specific embodiment, the structural formula of the glucose-1-O-fatty acid ester is:

[0023] ;

[0024] Wherein, R is a straight-chain alkyl group with carbon chain numbers of 9, 11, 13, 15 and 17.

[0025] In one specific embodiment, the reaction process of the preparation method is as follows:

[0026] .

[0027] In one specific embodiment, the molar ratio of 2,3,4,6-tetra-O-trimethylsilylgluconic acid δ-lactone, sodium borohydride, and calcium chloride is 1:(1~1.4):(0.2~0.4), preferably, the molar ratio of 2,3,4,6-tetra-O-trimethylsilylgluconic acid δ-lactone, sodium borohydride, and calcium chloride is 1:1.1:0.3.

[0028] In one specific embodiment, the molar ratio of 2,3,4,6-tetra-O-trimethylsilylglucose, triethylamine, and fatty acyl chloride is 1:(1~1.3):(1~1.05). Preferably, the molar ratio of 2,3,4,6-tetra-O-trimethylsilylglucose, triethylamine, and fatty acyl chloride is 1:1.2:1.05.

[0029] Secondly, this application provides a glucose-1-O-fatty acid ester, which is prepared by the above-described preparation method.

[0030] Thirdly, this application provides a reconstituted tobacco coating liquid comprising the aforementioned glucose-1-O-fatty acid ester.

[0031] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0032] (1) The glucose-1-O-fatty acid ester prepared by the present invention is obtained by using gluconate δ-lactone as raw material and undergoing four steps of TMS protection, reduction, esterification and deprotection to obtain the target product. The raw materials are inexpensive and are all conventional reagents. The reaction process is simple and does not require pressure heating and column chromatography. The product yield is high and all are monoesters with no polyester byproducts.

[0033] (2) The glucose-1-O-fatty acid ester prepared in this invention can be added to the reconstituted tobacco coating solution to improve the permeability of the coating solution and increase the coating rate and coating uniformity. Attached Figure Description

[0034] To more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort. In the drawings:

[0035] Figure 1 The results of the permeability test of glucose laurate on reconstituted tobacco leaf substrate in Example 1 of this invention;

[0036] Figure 2 The results of the permeability test of glucose laurate on reconstituted tobacco leaf substrate in Example 2 of this invention;

[0037] Figure 3 The results of the permeability test of glucose laurate on reconstituted tobacco leaf substrate in Example 3 of this invention;

[0038] Figure 4 The results of the permeability test of glucose laurate on reconstituted tobacco leaf substrate in Example 4 of this invention;

[0039] Figure 5 The results of the permeability test of glucose laurate on reconstituted tobacco leaf substrate in Example 5 of the present invention are shown. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the embodiments. The illustrative embodiments and descriptions of this invention are only used to explain this invention and are not intended to limit this invention.

[0041] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that these specific details are not necessary to practice the invention. In other embodiments, well-known materials or methods have not been specifically described in order to avoid obscuring the invention.

[0042] Throughout this specification, references to "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in connection with that embodiment or example is included in at least one embodiment of the invention. Therefore, the phrases "an embodiment," "an example," "an example," or "an example" appearing in various places throughout the specification do not necessarily refer to the same embodiment or example. Furthermore, specific features, structures, or characteristics can be combined in one or more embodiments or examples in any suitable combination and / or sub-combination. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described herein, as well as the features of those different embodiments or examples.

[0043] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60–120 and 80–110 are listed for a specific parameter, it is understood that ranges of 60–110 and 80–120 are also expected. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1–3, 1–4, 1–5, 2–3, 2–4, and 2–5. In this application, unless otherwise stated, the numerical range "a–b" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0~5" indicates that all real numbers between "0~5" have been listed in this article; "0~5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0044] Unless otherwise specified, all steps in this application may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the method may also include step (c), indicating that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0045] Example 1

[0046] This embodiment provides a method for preparing glucose-1-O-decanoate, the specific preparation steps of which are as follows:

[0047] Synthesis of S1- and TMS-protected glucono-δ-lactone

[0048] 100 g of gluconate δ-lactone was placed in tetrahydrofuran, and 300 g of N-methylmorpholine and 200 g of trimethylchlorosilane were added sequentially. The reaction was carried out at room temperature until complete. The reactants were washed sequentially with saturated brine and saturated potassium dihydrogen phosphate. The organic phase was dried with anhydrous sodium sulfate and concentrated to give 255 g of 2,3,4,6-tetra-O-trimethylsilylgluconate δ-lactone (TMS-protected gluconate δ-lactone), with a yield of 97%.

[0049] S2 and TMS-protected glucose synthesis

[0050] 100 g of TMS-protected gluconate δ-lactone was placed in methanol, and 7 g of calcium chloride and 9 g of sodium borohydride were added sequentially. The reaction was carried out at room temperature until complete, and the solvent was evaporated. The reactants were concentrated and ethyl acetate was added. The mixture was washed with water, and the organic phase was dried with anhydrous sodium sulfate and concentrated to give 96.5 g of 2,3,4,6-tetra-O-trimethylsilylglucose (TMS-protected glucose), with a yield of 96%.

[0051] Synthesis of S3 and TMS-protected glucose fatty acid esters

[0052] 50 g of TMS-protected glucose was placed in dichloromethane, and 13 g of triethylamine and 24.4 g of decanoyl chloride were added sequentially. The reaction was carried out at room temperature until complete. The organic phase was washed with saturated brine, dried and concentrated to give 65 g of 2,3,4,6-tetra-O-trimethylsilylglucose-1-O-decanoate (TMS-protected glucose fatty acid ester), with a yield of 98%.

[0053] S4, Synthesis of Glucose Fatty Acid Esters

[0054] 50 g of TMS-protected glucose fatty acid ester was placed in a methanol solution of 0.1% hydrochloric acid and reacted to completion at room temperature. The reaction solution was concentrated to give 26 g of glucose-1-O-decanoate. The yield was 96%.

[0055] The structure of glucose-1-O-decanoate was identified using nuclear magnetic resonance spectroscopy, and the spectral data are as follows: 1H NMR(600 MHz, DMSO-d6) δ 5.95 (d, J = 3.7 Hz, 1H), 5.07 (d, J = 6.0 Hz, 1H), 5.02(d, J = 5.6 Hz, 1H), 4.94 (d, J = 5.0 Hz, 1H), 4.50 (t, J = 5.9 Hz, 1H),3.58-3.55 (m, 1H), 3.48-3.41 (m, 3H), 3.35-3.32 (m, 1H), 3.20-3.15 (m, 1H),2.35-2.31 (m, 2H), 1.55-1.51 (m, 2H), 1.27-1.24 (m, 12H), 0.86 (t, J = 6.9Hz, 3H). 13 C NMR (150MHz, DMSO-d6) δ 172.46, 92.32, 75.61, 73.49, 71.01, 69.78, 60.92, 34.21, 31.76, 29.36, 29.21, 29.14, 28.85, 24.87, 22.57, 14.44. From the proton NMR spectrum, it can be seen that the seven hydrogens at δ 5.95 to 3.55 (including one hydrogen at 3.48-3.41) correspond to the hydrogen signals of the glucose unit, and the rest are decyl hydrogen signals. From the carbon NMR spectrum, it can be seen that δ 172.46 is the C=O carbon signal of the ester group, the six carbons at δ 92.32 to 60.92 are the carbon signals of the glucose unit, and the rest are decyl carbon signals.

[0056] Permeability test of glucose decanoate on reconstituted tobacco leaf substrate:

[0057] Dissolve glucose decanoate in the coating solution to prepare a 0.1% test solution. Apply 5 μL of the test solution to the substrate of the reconstituted tobacco leaf. Measure the diffusion diameter after 5 minutes. The results are as follows: Figure 1 As shown, the average diffusion diameter of the control coating solution was 3 mm, while the average diffusion diameter of the test solution was 5 mm. Furthermore, the penetration mark of the test solution on the back of the substrate was more obvious than that of the coating solution, indicating that the permeability of the coating solution was significantly improved after the addition of glucose decanoate.

[0058] Example 2

[0059] This embodiment provides a method for preparing glucose-1-O-laurate, the specific preparation steps of which are as follows:

[0060] Synthesis of S1- and TMS-protected glucono-δ-lactone

[0061] 100 g of gluconate δ-lactone was placed in tetrahydrofuran, and 300 g of N-methylmorpholine and 200 g of trimethylchlorosilane were added sequentially. The reaction was carried out at room temperature until complete. The reactants were washed sequentially with saturated brine and saturated potassium dihydrogen phosphate. The organic phase was dried with anhydrous sodium sulfate and concentrated to give 255 g of 2,3,4,6-tetra-O-trimethylsilylgluconate δ-lactone (TMS-protected gluconate δ-lactone), with a yield of 97%.

[0062] S2 and TMS-protected glucose synthesis

[0063] 100 g of TMS-protected gluconate δ-lactone was placed in methanol, and 7 g of calcium chloride and 9 g of sodium borohydride were added sequentially. The reaction was carried out at room temperature until complete, and the solvent was evaporated. The reactants were concentrated and ethyl acetate was added. The mixture was washed with water, and the organic phase was dried with anhydrous sodium sulfate and concentrated to give 96.5 g of 2,3,4,6-tetra-O-trimethylsilylglucose (TMS-protected glucose), with a yield of 96%.

[0064] Synthesis of S3 and TMS-protected glucose fatty acid esters

[0065] 50 g of TMS-protected glucose was placed in dichloromethane, and 13 g of triethylamine and 24.5 g of lauroyl chloride were added sequentially. The reaction was carried out at room temperature until complete. The organic phase was washed with saturated brine, dried and concentrated to give 68 g of 2,3,4,6-tetra-O-trimethylsilylglucose-1-O-laurate (TMS-protected glucose fatty acid ester), with a yield of 98%.

[0066] S4, Synthesis of Glucose Fatty Acid Esters

[0067] 50 g of TMS-protected glucose fatty acid ester was placed in a methanol solution of 0.1% hydrochloric acid and reacted at room temperature until complete. The reaction solution was concentrated to give 27 g of glucose-1-O-laurate. The yield was 97%.

[0068] The structure of glucose-1-O-laurate was identified using nuclear magnetic resonance spectroscopy, and the spectral data are as follows: 1H NMR(600 MHz, DMSO-d6) δ 5.95 (d, J = 3.7 Hz, 1H), 5.07 (d, J = 6.0 Hz, 1H), 5.02(d, J = 5.5 Hz, 1H), 4.94 (d, J = 4.9 Hz, 1H), 4.50 (t, J = 5.9 Hz, 1H),3.58-3.55 (m, 1H), 3.48-3.41 (m, 3H), 3.35-3.32 (m, 1H), 3.19-3.15 (m, 1H),2.35-2.31 (m, 2H), 1.55-1.51 (m, 2H), 1.27-1.24 (m, 16H), 0.86 (t, J = 6.9Hz, 3H). 13 C NMR (150 MHz, DMSO-d6) δ 172.45, 92.32, 75.61, 73.49, 71.01,69.78, 60.91, 34.21, 31.78, 29.50, 29.49, 29.41, 29.22, 29.19, 28.86, 24.86,22.58, 14.43. The proton spectrum shows that the seven hydrogens at δ 5.95 to 3.55 (including one hydrogen at 3.48-3.41) correspond to the hydrogen signals of the glucose unit, while the rest are lauryl hydrogen signals. The carbon spectrum shows that δ 172.45 is the C=O carbon signal of the ester group, the six carbons at δ 92.32 to 60.91 are the carbon signals of the glucose unit, and the rest are lauryl carbon signals.

[0069] Permeability test of glucose laurate on reconstituted tobacco leaf substrate:

[0070] Dissolve glucose laurate in the coating solution to prepare a 0.2 g / L test solution. Apply 5 μL of the test solution to the substrate of the reconstituted tobacco leaf. Measure the diffusion diameter after 5 minutes. The results are as follows: Figure 2 As shown, the average diffusion diameter of the control coating solution was 3 mm, while the average diffusion diameter of the test solution was 5 mm. Furthermore, the penetration mark of the test solution on the back of the substrate was more obvious than that of the coating solution, indicating that the permeability of the coating solution was significantly improved after the addition of glucose laurate.

[0071] Example 3

[0072] This embodiment provides a method for preparing glucose-1-O-myristate, the specific preparation steps of which are as follows:

[0073] Synthesis of S1- and TMS-protected glucono-δ-lactone

[0074] 100 g of gluconate δ-lactone was placed in tetrahydrofuran, and 300 g of N-methylmorpholine and 200 g of trimethylchlorosilane were added sequentially. The reaction was carried out at room temperature until complete. The reactants were washed sequentially with saturated brine and saturated potassium dihydrogen phosphate. The organic phase was dried with anhydrous sodium sulfate and concentrated to give 255 g of 2,3,4,6-tetra-O-trimethylsilylgluconate δ-lactone (TMS-protected gluconate δ-lactone), with a yield of 97%.

[0075] S2 and TMS-protected glucose synthesis

[0076] 100 g of TMS-protected gluconate δ-lactone was placed in methanol, and 7 g of calcium chloride and 9 g of sodium borohydride were added sequentially. The reaction was carried out at room temperature until complete, and the solvent was evaporated. The reactants were concentrated and ethyl acetate was added. The mixture was washed with water, and the organic phase was dried with anhydrous sodium sulfate and concentrated to give 96.5 g of 2,3,4,6-tetra-O-trimethylsilylglucose (TMS-protected glucose), with a yield of 96%.

[0077] Synthesis of S3 and TMS-protected glucose fatty acid esters

[0078] 50 g of TMS-protected glucose was placed in dichloromethane, and 13 g of triethylamine and 27.6 g of myristoyl chloride were added sequentially. The reaction was carried out at room temperature until complete. The organic phase was washed with saturated brine, dried and concentrated to give 71 g of 2,3,4,6-tetra-O-trimethylsilylglucose-1-O-myristate (TMS-protected glucose fatty acid ester), with a yield of 98%.

[0079] S4, Synthesis of Glucose Fatty Acid Esters

[0080] 50 g of TMS-protected glucose fatty acid ester was placed in a methanol solution of 0.1% hydrochloric acid and reacted at room temperature until complete. The reaction solution was concentrated to give 28 g of glucose-1-O-myristate. The yield was 96%.

[0081] The structure of glucose-1-O-myristate was identified using nuclear magnetic resonance spectroscopy, and its spectral data are as follows: 1HNMR (600 MHz, DMSO-d6) δ 5.95 (d, J = 3.7 Hz, 1H), 5.08 (d, J = 6.0 Hz, 1H), 5.03 (d, J = 5.6 Hz, 1H), 4.95 (d, J = 4.9 Hz, 1H), 4.51 (t, J = 5.9 Hz, 1H),3.58-3.55 (m, 1H), 3.49-3.41 (m, 3H), 3.35-3.32 (m, 1H), 3.19-3.15 (m, 1H),2.33 (td, J = 7.4, 4.6 Hz, 2H), 1.55-1.52 (m, 2H), 1.27-1.24 (m, 20H), 0.86(t, J = 6.9 Hz, 3H). 13 C NMR (150 MHz, DMSO-d6) δ 172.46, 92.32, 75.62, 73.48,71.01, 69.78, 60.91, 34.21, 31.77, 29.53, 29.49, 29.41, 29.22, 29.18, 28.86,24.87, 22.57, 14.43. The proton NMR spectrum shows that the seven hydrogens at δ 5.95 to 3.55 (including one hydrogen at 3.49-3.41) correspond to the hydrogen signals of the glucose unit, while the rest are myristyl hydrogen signals. The carbon NMR spectrum shows that δ 172.46 is the C=O carbon signal of the ester group, and the six carbons at δ 92.32 to 60.91 are the carbon signals of the glucose unit, while the rest are myristyl carbon signals.

[0082] Permeation test of gluconate myristate on reconstituted tobacco leaf substrate:

[0083] Dissolve gluconate myristate in the coating solution to prepare a 0.1% test solution. Apply 5 μL of the test solution to the substrate of the reconstituted tobacco leaf. Measure the diffusion diameter after 5 minutes. The results are as follows: Figure 3 As shown, the average diffusion diameter of the control coating solution was 3 mm, while the average diffusion diameter of the test solution was 4.5 mm. Furthermore, the penetration mark of the test solution on the back of the substrate was more obvious than that of the coating solution, indicating that the permeability of the coating solution was significantly improved after the addition of glucose myristate.

[0084] Example 4

[0085] This embodiment provides a method for preparing glucose-1-O-palmitate, the specific preparation steps of which are as follows:

[0086] Synthesis of S1- and TMS-protected glucono-δ-lactone

[0087] 100 g of gluconate δ-lactone was placed in tetrahydrofuran, and 300 g of N-methylmorpholine and 200 g of trimethylchlorosilane were added sequentially. The reaction was carried out at room temperature until complete. The reactants were washed sequentially with saturated brine and saturated potassium dihydrogen phosphate. The organic phase was dried with anhydrous sodium sulfate and concentrated to give 255 g of 2,3,4,6-tetra-O-trimethylsilylgluconate δ-lactone (TMS-protected gluconate δ-lactone), with a yield of 97%.

[0088] S2 and TMS-protected glucose synthesis

[0089] 100 g of TMS-protected gluconate δ-lactone was placed in methanol, and 7 g of calcium chloride and 9 g of sodium borohydride were added sequentially. The reaction was carried out at room temperature until complete, and the solvent was evaporated. The reactants were concentrated and ethyl acetate was added. The mixture was washed with water, and the organic phase was dried with anhydrous sodium sulfate and concentrated to give 96.5 g of 2,3,4,6-tetra-O-trimethylsilylglucose (TMS-protected glucose), with a yield of 96%.

[0090] Synthesis of S3 and TMS-protected glucose fatty acid esters

[0091] 50 g of TMS-protected glucose was placed in dichloromethane, and 13 g of triethylamine and 30.8 g of palmitoyl chloride were added sequentially. The reaction was carried out at room temperature until complete. The organic phase was washed with saturated brine, dried and concentrated to give 74 g of 2,3,4,6-tetra-O-trimethylsilylglucose-1-O-palmitate (TMS-protected glucose fatty acid ester), with a yield of 98%.

[0092] S4, Synthesis of Glucose Fatty Acid Esters

[0093] 50 g of TMS-protected glucose fatty acid ester was placed in a methanol solution of 0.1% hydrochloric acid and reacted to completion at room temperature. The reaction solution was concentrated to give 28 g of glucose-1-O-palmitate. The yield was 96%.

[0094] The structure of glucose-1-O-palmitate was identified using nuclear magnetic resonance spectroscopy, and its spectral data are as follows: 1H NMR(600 MHz, DMSO-d6) δ 5.95 (d, J = 3.6 Hz, 1H), 5.08 (d, J = 5.9 Hz, 1H), 5.03(d, J = 5.5 Hz, 1H), 4.95 (d, J = 4.5 Hz, 1H), 4.51 (t, J = 5.9 Hz, 1H),3.58-3.55 (m, 1H), 3.49-3.42 (m, 3H), 3.35-3.32 (m, 1H), 3.19-3.15 (m, 1H),2.35-2.32 (m, 2H), 1.55-1.52 (m, 2H), 1.28-1.24 (m, 24H), 0.86 (t, J = 6.9Hz, 3H). 13 C NMR (150 MHz, DMSO-d6) 172.46, 92.32, 75.61, 73.48, 71.00, 69.77,60.91, 34.20, 31.77, 29.54, 29.53, 29.49, 29.41, 29.21, 29.19, 28.86, 24.86,22.57, 14.43. The proton NMR spectrum shows that the seven hydrogens at δ 5.95 to 3.55 (including one hydrogen at δ 3.49-3.42) correspond to the hydrogen signals of the glucose unit, while the rest are the hydrogen signals of the palmityl group. The carbon NMR spectrum shows that δ 172.46 is the C=O carbon signal of the ester group, and the six carbons at δ 92.32 to 60.91 are the carbon signals of the glucose unit, while the rest are the carbon signals of the palmityl group.

[0095] Permeability test of glucopalmitate on reconstituted tobacco leaf substrate:

[0096] Dissolve glucose palmitate in the coating solution to prepare a 0.1% test solution. Apply 5 μL of the test solution to the substrate of the reconstituted tobacco leaf. Measure the diffusion diameter after 5 minutes. The results are as follows: Figure 4 As shown, the average diffusion diameter of the control coating solution was 3 mm, while the average diffusion diameter of the test solution was 4 mm. Furthermore, the penetration mark of the test solution on the back of the substrate was more obvious than that of the coating solution, indicating that the permeability of the coating solution was significantly improved after the addition of glucose palmitate.

[0097] Example 5

[0098] This embodiment provides a method for preparing glucose-1-O-stearate, the specific preparation steps of which are as follows:

[0099] Synthesis of S1- and TMS-protected glucono-δ-lactone

[0100] 100 g of gluconate δ-lactone was placed in tetrahydrofuran, and 300 g of N-methylmorpholine and 200 g of trimethylchlorosilane were added sequentially. The reaction was carried out at room temperature until complete. The reactants were washed sequentially with saturated brine and saturated potassium dihydrogen phosphate. The organic phase was dried with anhydrous sodium sulfate and concentrated to give 255 g of 2,3,4,6-tetra-O-trimethylsilylgluconate δ-lactone (TMS-protected gluconate δ-lactone), with a yield of 97%.

[0101] S2 and TMS-protected glucose synthesis

[0102] 100 g of TMS-protected gluconate δ-lactone was placed in methanol, and 7 g of calcium chloride and 9 g of sodium borohydride were added sequentially. The reaction was carried out at room temperature until complete, and the solvent was evaporated. The reactants were concentrated and ethyl acetate was added. The mixture was washed with water, and the organic phase was dried with anhydrous sodium sulfate and concentrated to give 96.5 g of 2,3,4,6-tetra-O-trimethylsilylglucose (TMS-protected glucose), with a yield of 96%.

[0103] Synthesis of S3 and TMS-protected glucose fatty acid esters

[0104] 50 g of TMS-protected glucose was placed in dichloromethane, and 13 g of triethylamine and 33.9 g of stearyl chloride were added sequentially. The reaction was carried out at room temperature until complete. The organic phase was washed with saturated brine, dried and concentrated to give 76.8 g of 2,3,4,6-tetra-O-trimethylsilylglucose-1-O-stearate (TMS-protected glucose fatty acid ester), with a yield of 98%.

[0105] S4, Synthesis of Glucose Fatty Acid Esters

[0106] 50 g of TMS-protected glucose fatty acid ester was placed in a methanol solution of 0.1% hydrochloric acid and reacted at room temperature until complete. The reaction solution was concentrated to give 29 g of glucose-1-O-stearate. The yield was 97%.

[0107] The structure of glucose-1-O-stearate was identified using nuclear magnetic resonance spectroscopy, and the spectral data are as follows: 1H NMR(600 MHz, DMSO-d6) δ 5.95 (d, J = 3.7 Hz, 1H), 5.10 (d, J = 5.8 Hz, 1H), 5.04(d, J = 5.4 Hz, 1H), 4.97 (d, J = 2.5 Hz, 1H), 4.53 (t, J = 5.9 Hz, 1H),3.58-3.55 (m, 1H), 3.48-3.41 (m, 3H), 3.35-3.32 (m, 1H), 3.19-3.15 (m, 1H),2.33 (td, J = 7.4, 4.7 Hz, 2H), 1.55-1.53 ​​(m, 2H), 1.29-1.24 (m, 28H), 0.86(t, J = 7.0 Hz, 3H). 13 C NMR (150 MHz, DMSO-d6) 172.47, 92.31, 75.61, 73.47,70.99, 69.75, 60.89, 34.20, 31.78, 29.54, 29.50, 29.42, 29.23, 29.20, 28.87,24.87, 22.58, 14.44. The proton NMR spectrum shows that the seven hydrogens at δ 5.95 to 3.55 (including one hydrogen at δ 3.48-3.41) correspond to the hydrogen signals of the glucose unit, while the rest are hydrogen signals of the stearyl group. The carbon NMR spectrum shows that δ 172.47 is the C=O carbon signal of the ester group, and the six carbons at δ 92.31 to 60.89 are the carbon signals of the glucose unit, while the rest are carbon signals of the stearyl group.

[0108] Permeability test of glucostearate on reconstituted tobacco leaf substrate:

[0109] Dissolve glucose stearate in the coating solution to prepare a 0.1% test solution. Apply 5 μL of the test solution to the substrate of the reconstituted tobacco leaf. Measure the diffusion diameter after 5 minutes. The results are as follows: Figure 4 As shown, the average diffusion diameter of the control coating solution was 3 mm, while the average diffusion diameter of the test solution was 3.5 mm. Furthermore, the penetration mark of the test solution on the back of the substrate was more obvious than that of the coating solution, indicating that the permeability of the coating solution was significantly improved after the addition of glucose stearate.

[0110] The permeability of glucose decanoate, glucose laurate, glucose myristate, glucose palmitate, and glucose stearate prepared using the methods in Examples 1-5 was tested, with distilled water as a blank control. Wetting power of glucose fatty acid esters was determined to evaluate the permeability of the test compounds. The wetting power test was performed according to GB / T11983-2008 "Determination of Wetting Power - Immersion Method," using a fishhook instead of an immersion clamp: a 0.5 g / L solution of glucose fatty acid esters was prepared and maintained at (20±2) °C. A equilibrated standard cotton fabric piece was taken, and a #1 fishhook was hooked into the edge of the fabric piece. The other end of the fishhook was tied with a thread, which was connected to a wire frame. The wire frame immersed the fabric piece in the solution (1-2 cm below the solution surface). A stopwatch was started, and the time was stopped when the fabric piece began to settle. This was repeated 10 times, and the average value was recorded as the settling time. The test results are shown in Table 1 below.

[0111] Table 1

[0112]

[0113] The test data in Table 1 show that the sedimentation time was significantly shortened after the addition of glucose fatty acid ester, indicating that glucose fatty acid ester has wetting and penetrating effects.

[0114] Finally, it should be noted that the specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention. It is obvious to those skilled in the art that this application is not limited to the details of the above exemplary embodiments, and that the present application can be implemented in other specific forms without departing from the spirit or basic characteristics of the present application. Therefore, the embodiments should be considered exemplary and non-limiting in all respects. The scope of this application is defined by the appended claims rather than the foregoing description, and therefore all changes falling within the meaning and scope of the equivalents of the claims are intended to be included within this application.

Claims

1. A method for preparing glucose-1-O-fatty acid esters, characterized in that, Includes the following steps: δ-gluconolactone was placed in tetrahydrofuran, and then N-methylmorpholine and trimethylchlorosilane were added. The reaction was completed at room temperature. The organic phase was washed, dried and concentrated to obtain 2,3,4,6-tetra-O-trimethylsilylgluconolactone. 2,3,4,6-tetra-O-trimethylsilylglucanol δ-lactone was dissolved in methanol, and then calcium chloride and sodium borohydride were added. After the reaction was completed at room temperature, the solvent was evaporated. The organic phase was washed, dried and concentrated to obtain 2,3,4,6-tetra-O-trimethylsilylglucose. 2,3,4,6-tetra-O-trimethylsilylglucose was placed in dichloromethane, and then triethylamine and fatty acyl chloride were added. The reaction was completed at room temperature. The organic phase was washed, dried and concentrated to obtain 2,3,4,6-tetra-O-trimethylsilylglucose-1-O-fatty acid ester. 2,3,4,6-tetra-O-trimethylsilylglucose-1-O-fatty acid ester was placed in a methanol solution containing hydrochloric acid and reacted completely at room temperature. The reaction solution was then concentrated to obtain glucose-1-O-fatty acid ester.

2. The method for preparing a glucose-1-O-fatty acid ester according to claim 1, characterized in that, The structural formula of the 2,3,4,6-tetra-O-trimethylsilylgluconate δ-lactone is: ； TMS stands for trimethylsilane.

3. The method for preparing a glucose-1-O-fatty acid ester according to claim 1, characterized in that, The structural formula of the 2,3,4,6-tetra-O-trimethylsilylglucose is: ； TMS stands for trimethylsilane.

4. The method for preparing a glucose-1-O-fatty acid ester according to claim 1, characterized in that, The structural formula of the 2,3,4,6-tetra-O-trimethylsilylglucose-1-O-fatty acid ester is: ； Wherein, TMS is trimethylsilane; R is a straight-chain alkyl group with carbon chain numbers of 9, 11, 13, 15 and 17.

5. The method for preparing a glucose-1-O-fatty acid ester according to claim 1, characterized in that, The structural formula of the glucose-1-O-fatty acid ester is: ； Wherein, R is a straight-chain alkyl group with carbon chain numbers of 9, 11, 13, 15 and 17.

6. The method for preparing a glucose-1-O-fatty acid ester according to claim 1, characterized in that, The reaction process of the preparation method is as follows: 。 7. The method for preparing a glucose-1-O-fatty acid ester according to claim 1, characterized in that, The molar ratio of 2,3,4,6-tetra-O-trimethylsilylgluconolactone, sodium borohydride, and calcium chloride is 1:(1~1.4):(0.2~0.4).

8. The method for preparing a glucose-1-O-fatty acid ester according to claim 1, characterized in that, The molar ratio of 2,3,4,6-tetra-O-trimethylsilylglucose, triethylamine, and fatty acyl chloride is 1:(1~1.3):(1~1.05).

9. A glucose-1-O-fatty acid ester, characterized in that, It is prepared by the preparation method described in any one of claims 1 to 8.

10. A reconstituted tobacco coating liquid, characterized in that, Including the glucose-1-O-fatty acid ester as described in claim 9.

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