Composition for improving stability of oleuropein in solution as well as preparation method and application of composition

Abstract

The invention discloses a composition for improving the stability of oleuropein in a solution as well as a preparation method and application of the composition. The composition comprises oleuropein and at least one stabilizer, and the stabilizer is selected from the group consisting of anisic acid, lactobionic acid, glycyrrhizic acid, 3, 3-thiodipropionic acid, N-acetyl-L-glutamine, propyl-cysteine and lauramidopropyl betaine; and the pH value of the aqueous solution of the composition is 4.0-8.0. The preparation method comprises the following steps: dissolving oleuropein in water, adding the stabilizer, and uniformly mixing. Through simple physical mixing, by utilizing the synergistic effect of the specific stabilizer and the oleuropein, the degradation and discoloration of the oleuropein in the storage process are remarkably inhibited. Experiments show that after the preferable composition is preserved for 30 days in an open manner, the retention rate of the oleuropein still reaches up to 80% or above, and is far superior to that of blank control and a traditional liposome wrapping method. The composition is simple and convenient in preparation process and low in cost, and provides reliable technical support for wide application of oleuropein in liquid products such as food, medicine and cosmetics.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of natural product stabilization, and particularly relates to a composition capable of significantly improving the stability of oleuropein in solution and a preparation method thereof. In particular, the present application effectively inhibits the degradation of oleuropein during storage by combining it with a specific stabilizer, thereby broadening its application in the fields of food, medicine, cosmetics, and the like. BACKGROUND

[0002] Oleuropein is a seco-iridoid glycoside compound abundant in olive trees, has various pharmacological activities such as antioxidant, anti-inflammatory, antibacterial, and cardiovascular protection, and has a broad application prospect. However, the chemical structure of oleuropein contains ester bonds and phenolic hydroxyl groups that are highly sensitive to environmental factors, and is easily affected by light, heat, pH, oxygen, and metal ions during production, storage, and use, thereby undergoing hydrolysis, oxidation, and isomerization degradation reactions, resulting in a significant decrease in its biological activity and a change in color, which seriously restricts the development and industrialization process of high-value-added products with it as a core component.

[0003] At present, in order to improve the stability of oleuropein, the industry mainly adopts two categories of technologies, physical methods and chemical methods. Physical methods (such as liposome embedding) aim to build a micro "protective shell" for oleuropein, physically isolating it from the external environment; chemical methods (such as β-cyclodextrin inclusion) change the microenvironment of oleuropein at the molecular level through specific interactions between host and guest molecules, shielding its sensitive sites. However, these existing technologies generally have the defects of limited loading capacity, high cost, and complex process, which limit their large-scale application.

[0004] In addition, there are also reports that adding specific antioxidants (such as oxothiazolidine carboxylic acid) can improve the discoloration problem of oleuropein, which provides a new idea for stabilization technology, but the types of available, efficient, and economical stabilizers are still very limited.

[0005] Therefore, there is an urgent need in the field to develop more novel, efficient, and easy-to-implement compositions and methods to solve the stability problem of oleuropein, in order to promote the commercial development of its related products. SUMMARY

[0006] The purpose of the present application is to overcome the shortcomings of existing oleuropein stabilization technologies and provide a series of new oleuropein stabilization compositions and preparation methods thereof.

[0007] To solve the above technical problems, the technical scheme adopted by the present application is as follows: A method for improving the stability of oleuropein in solution, combining oleuropein with one or more stabilizers in an aqueous solution to form a stable composition; the stabilizer is selected from at least one of the following group: anisic acid, lactobionic acid, glycyrrhizic acid, 3,3-thiodipropionic acid, N-acetyl-L-glutamine, propyl-cysteine, lauryl amide propyl betaine.

[0008] Preferably, the pH value of the aqueous solution of the composition ranges from 4.0 to 8.0.

[0009] Preferably, the stabilizer is 3,3-thiodipropionic acid.

[0010] A method for preparing the oleuropein composition, comprising the following steps: Dissolve oleuropein in water to prepare an oleuropein solution (solution A).

[0011] Add the stabilizer to solution A and mix uniformly by vortexing to obtain the oleuropein composition solution.

[0012] The initial concentration of oleuropein is 1-5 mg / mL, the molar ratio of the amount of stabilizer added to oleuropein is 1:1-8:1, and the vortex mixing time is 1-5 minutes.

[0013] Compared with the prior art, the oleuropein composition and the preparation method thereof provided by the present application have the following remarkable beneficial effects: 1. The stability is significantly improved: the various stabilizers provided by the present application can inhibit the degradation of oleuropein to varying degrees. In particular, the composition formed with 3,3-thiodipropionic acid has the most outstanding effect, and after 30 days of open storage, the retention rate of oleuropein can still be as high as 80.19%, which is much higher than the 41.99% of the blank control group and the 62.41% of the liposome-encapsulated group.

[0014] 2. Simple operation and low cost: the method only requires simple physical mixing, without the need for complex equipment or tedious processes, significantly reducing the production threshold and cost.

[0015] 3. Broaden the application prospect: by effectively solving the stability problem of oleuropein in solution, the present application provides a solid technical foundation for the development and industrialization of terminal products such as liquid food, beverage, oral liquid, and cosmetic serum for the active ingredient.

[0016] 4. Provide a new technical route: the present application discards the traditional embedding and complexation ideas, and by screening specific small molecule compounds that can produce synergistic stabilization with oleuropein, it provides a new direction and technical reserve for the stabilization of natural products. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 Appearance comparison of pure oleuropein solution and seven composition solutions after 20 days of storage under open condition; Figure 2 Appearance comparison of the above solutions after 30 days of storage under open condition; Figure 3 Comparison of the solutions of the composition showing particularly significant stability performance after 30 days of storage and the pure oleuropein solution; Figure 4 HPLC chromatogram of the pure oleuropein solution on day 0; Figure 5 HPLC chromatogram of the pure oleuropein solution on day 20; Figure 6 HPLC chromatogram of the pure oleuropein solution on day 30; Figure 7 HPLC chromatogram of the solution of composition E (containing 3,3-thiodipropionic acid) on day 20; Figure 8 HPLC chromatogram of the solution of composition E on day 30; Figure 9 HPLC chromatogram of the solution of composition G (containing propanesulfidylcysteine) on day 20; Figure 10 HPLC chromatogram of the solution of composition G on day 30; Figure 11 HPLC chromatogram of the solution of liposome-encapsulated oleuropein on day 20; Figure 12 HPLC chromatogram of the solution of liposome-encapsulated oleuropein on day 30. DETAILED DESCRIPTION

[0018] The application will be further described in detail below in conjunction with the accompanying drawings and examples. It should be noted that the following examples are only used to explain the application, and do not limit the scope of the application.

[0019] Example 1: Preparation of oleuropein composition solutions This example provides a general preparation method of seven different oleuropein composition solutions.

[0020] A certain amount of oleuropein standard was accurately weighed, dissolved in purified water, and vortexed to fully dissolve, to prepare an oleuropein stock solution with a concentration of 2 mg / mL (denoted as solution A).

[0021] Accurately weigh seven kinds of stabilizers respectively: anisic acid, lactobionic acid, glycyrrhizic acid, 3,3-thiodipropionic acid, N-acetyl-L-glutamine, propanesulfidylcysteine, lauryl amidopropyl betaine. The molar ratio of each stabilizer to oleuropein is 1:1.

[0022] Add the above seven kinds of stabilizers to a series of test tubes containing equal amounts of solution A, with each stabilizer corresponding to a test tube. Then use a vortex oscillator to shake each test tube vigorously for 1 minute to ensure that the stabilizers are completely dissolved and uniformly mixed, respectively obtaining composition solutions B, C, D, E, F, G, and H.

[0023] Use a pH meter to measure the pH of each composition solution, and if necessary, use dilute hydrochloric acid or sodium hydroxide solution to fine-tune the pH of all composition solutions to be stable within the range of 4.0-8.0.

[0024] Example 2: Composition stability verification (appearance observation) Store the seven composition solutions (B-H) prepared in Example 1 together with the pure oleuropein solution (A) of the same concentration in an open container at room temperature under natural light conditions.

[0025] As shown in Table 1 and Figures 1 to 3 After five days of storage, the pure oleuropein solution (A) showed obvious color deepening (e.g., turning yellow-brown), indicating oxidative degradation. Compared with the pure oleuropein solution, the color change of each composition solution was less severe, showing varying degrees of discoloration inhibition, directly proving the effectiveness of the composition of the present application in delaying the appearance degradation of oleuropein.

[0026] Example 3: Composition stability verification (HPLC quantitative analysis) This example uses 3,3-thiodipropionic acid (composition E), propanesulfidylcysteine (composition G), and liposome encapsulation as a comparison to evaluate long-term stability through HPLC quantitative analysis.

[0027] According to the method of Example 1, prepare pure oleuropein solution (blank), 3,3-thiodipropionic acid composition (E), propanesulfidylcysteine composition (G), and liposome-encapsulated oleuropein solution as a control.

[0028] Store all sample solutions at a temperature of 25°C under open conditions.

[0029] Take samples on days 0, 20, and 30, respectively, and detect the content of oleuropein in each sample by high-performance liquid chromatography (HPLC) to calculate the retention rate. As shown in Table 1 and Figures 4-12 Table 1 Oleuropein degradation rate ​ The results show that the retention rate of oleuropein in composition E (containing 3,3-thiodipropionic acid) is still as high as 80.19% after 33 days, which is significantly higher than that of the blank group (41.99%) and the liposome group (62.41%), indicating that it has excellent long-term stability.

Claims

1. A composition for improving the stability of oleuropein in solution, characterized in that, The composition comprises oleuropein and at least one stabilizer selected from one of the following group: aniseic acid, lactobionic acid, glycyrrhizic acid, 3,3-thiodipropionic acid, N-acetyl-L-glutamine, propanesulfidylcysteine, lauryl amidopropyl betaine; The pH value of the aqueous solution of the composition is 4.0-8.

0.

2. The composition of claim 1, wherein The stabilizer is 3,3-thiodipropionic acid.

3. The composition of claim 1, wherein The molar ratio of the stabilizer to oleuropein is 1:1-8:

1.

4. The composition of claim 1, wherein The retention rate of oleuropein in the composition after 30 days of open storage is not less than 80%.

5. A process for preparing the composition of claim 1, characterized in that, The method comprises the following steps: a. Dissolve oleuropein in water to obtain solution A; b. Add the stabilizer to solution A and mix uniformly to obtain the composition solution.

6. The method of claim 5, wherein, The mixing in step b. comprises vortex treatment, and the vortex time is 1-5 minutes.

7. The method of claim 5, wherein, The amount of the stabilizer added in step b. is 1-8 times the molar amount of oleuropein.

8. The method of claim 5, wherein, The pH value of the aqueous solution of the composition is adjusted to 4.0-8.

0.

9. Use of the composition according to any one of claims 1-4 in the preparation of food, medicine or cosmetics.

10. Use of the composition according to any one of claims 1-4 in improving the antioxidant, anti-inflammatory or antibacterial stability of oleuropein.

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