Epsilon-polylysine / sulfobutyl-beta-cyclodextrin / carvacrol inclusion compound and preparation method thereof

Abstract

The invention discloses an epsilon-polylysine / sulfobutyl-beta-cyclodextrin / carvacrol inclusion compound and a preparation method of the epsilon-polylysine / sulfobutyl-beta-cyclodextrin / carvacrol inclusion compound. The method comprises the following steps: dissolving epsilon-polylysine in ultrapure water, and adjusting the pH value to 5 to obtain an epsilon-polylysine solution; the preparation method comprises the following steps: dissolving sulfobutyl-beta-cyclodextrin and carvacrol in ultrapure water, and adjusting the pH value to 4 to obtain a sulfobutyl-beta-cyclodextrin / carvacrol mixed solution; and mixing the epsilon-polylysine solution and the sulfobutyl-beta-cyclodextrin / carvacrol mixed solution, carrying out stirring reaction for 2-6 hours under the conditions of 20-60 DEG C and 700rpm, and carrying out freeze drying to obtain the epsilon-polylysine / sulfobutyl-beta-cyclodextrin / carvacrol inclusion compound. The preparation operation is simple, and the prepared epsilon-polylysine / sulfobutyl-beta-cyclodextrin / carvacrol inclusion compound is high in encapsulation efficiency and drug loading rate and has excellent antibacterial performance.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of inclusion compounds, and particularly relates to an epsilon-polylysine / sulfobutyl-beta-cyclodextrin / carvacol inclusion compound and a preparation method thereof. BACKGROUND

[0002] Sulfobutyl-beta-cyclodextrin (SBE-beta-CD) is a derivative of beta-cyclodextrin, which has a hydrophilic outer surface and a hydrophobic cavity. The hydrophobic cavity of SBE-beta-CD can include hydrophobic small molecule compounds to form stable non-covalent complexes, which can effectively improve the bioavailability, and has the advantages of high stability, biocompatibility, and easy preparation and modification. Epsilon-polylysine (epsilon-PL) is initially isolated from Streptomyces subgenus, which is a polypeptide with 25-35 L-lysine and has broad-spectrum antibacterial activity. It can be used as a safe natural food preservative. Carvacol (5-isopropyl-2-methylphenol, CAR) is the main component of oregano and thyme essential oil, which has broad-spectrum antibacterial effect and biological activities such as anti-inflammatory, anticancer and antioxidant. However, due to its limited water solubility, low stability, easy volatility, and the rich aromatic smell of essential oil which can destroy the original flavor of food, its application in various fields is further limited. SUMMARY

[0003] The present application aims to provide an epsilon-polylysine / sulfobutyl-beta-cyclodextrin / carvacol inclusion compound and a preparation method thereof.

[0004] To achieve the above-mentioned purpose, the present application adopts the following technical solutions: A preparation method of an epsilon-polylysine / sulfobutyl-beta-cyclodextrin / carvacol inclusion compound, comprising the following steps: S1: dissolving epsilon-polylysine in ultrapure water, adjusting the pH to 5 to obtain an epsilon-polylysine solution; S2: dissolving sulfobutyl-beta-cyclodextrin and carvacol in ultrapure water, adjusting the pH to 4 to obtain a sulfobutyl-beta-cyclodextrin / carvacol mixed solution; S3: mixing the epsilon-polylysine solution and the sulfobutyl-beta-cyclodextrin / carvacol mixed solution, stirring at 20-60℃ and 700rpm for 2-6h, and freeze-drying to obtain the epsilon-polylysine / sulfobutyl-beta-cyclodextrin / carvacol inclusion compound.

[0005] Preferably, in the above preparation method, the concentration of epsilon-polylysine in the epsilon-polylysine solution is 0.5x10 -4 M.

[0006] Preferably, in the above preparation method, the molar ratio of epsilon-polylysine to sulfobutyl-beta-cyclodextrin is 1:40.

[0007] Preferably, in the above preparation method, the mass ratio of sulfobutyl-β-cyclodextrin:carvacrol is 2:1.

[0008] Preferably, in the above preparation method, the stirring reaction temperature is 50° C. and the time is 5 h.

[0009] An ε-polylysine / sulfobutyl-β-cyclodextrin / carvacrol inclusion compound is prepared by the above preparation method.

[0010] Use of the aforementioned ε-polylysine / sulfobutyl-β-cyclodextrin / carvacrol inclusion complex in the preparation of antibacterial materials; Preferably, the antibacterial material is a material that is resistant to Gram-positive bacteria and / or Gram-negative bacteria; Preferably, the Gram-positive bacteria is Escherichia coli, and the Gram-negative bacteria is Staphylococcus aureus.

[0011] The present invention is based on the design concept of synergistic antibacterial effect, and uses sulfobutyl-β-cyclodextrin as an intermediate medium to co-load carvacrol and ε-polylysine to prepare an inclusion complex. Sulfobutyl-β-cyclodextrin has a sulfobutyl anion group, and ε-polylysine is a cationic polypeptide with an amino group. The two may self-assemble with the help of electrostatic interactions to form an ε-polylysine / sulfobutyl-β-cyclodextrin polyelectrolyte complex; sulfobutyl-β-cyclodextrin is a derivative of β-cyclodextrin, with a hydrophilic outer profile and a hydrophobic cavity, and carvacrol is a hydrophobic essential oil. The hydrophobic cavity of sulfobutyl-β-cyclodextrin can include carvacrol to form a stable non-covalent complex to improve its defects of low water solubility and low bioavailability. The ε-polylysine / sulfobutyl-β-cyclodextrin / carvacrol inclusion complex prepared by the present invention has the following advantages: (1) The solubility of carvacrol in water increases and its dispersibility is better.

[0012] (2) Sulfonbutyl-β-cyclodextrin loaded with two antibacterial active ingredients can exert the synergistic antibacterial effect of carvacrol and ε-polylysine.

[0013] (3) Sulfobutyl-β-cyclodextrin is used as a wall material to embed carvacrol, which can avoid the strong aromatic odor of carvacrol itself affecting the flavor of food.

[0014] (4) The encapsulation efficiency of CAR reached 71.07±1.83%, and the drug loading rate reached 24.65±1.37%.

[0015] (5) The preparation process of the inclusion compound is simple and can be easily applied to industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 : Encapsulation efficiency and drug loading rate of inclusion complex.

[0017] Figure 2 : SEM image of inclusion complex.

[0018] Figure 3 : Antibacterial activity of inclusion complex.

[0019] Note: SBE-β-CD / CAR: sulfobutyl-β-cyclodextrin / carvacrol inclusion complex; ε-PL / SBE-β-CD / CAR or SBE-β-CD / ε-PL / CAR: ε-polylysine / sulfobutyl-β-cyclodextrin / carvacrol inclusion complex; SBE-β-CD / ε-PL: ε-polylysine / sulfobutyl-β-cyclodextrin inclusion complex. DETAILED DESCRIPTION

[0020] In order to make the contents of the present invention easier to understand, the technical solutions of the present invention are further described below in conjunction with specific implementation methods, but the present invention is not limited thereto.

[0021] In the present invention, the CAS number of ε-polylysine (ε-PL) is 25104-18-1, the CAS number of sulfobutyl-β-cyclodextrin (SBE-β-CD) is 182410-00-0, and the CAS number of carvacrol (CAR) is 499-75-2.

[0022] Example 1: A method for preparing an ε-polylysine / sulfobutyl-β-cyclodextrin / carvacrol inclusion complex is carried out according to the following steps: S1: Dissolve ε-polylysine in 7 mL of ultrapure water and adjust the pH to 5 with a 1 M HCl aqueous solution to obtain an ε-polylysine solution; S2: Dissolve sulfobutyl-β-cyclodextrin and carvacrol in 7 mL of ultrapure water, and adjust the pH to 4 with 1 M HCl aqueous solution to obtain a sulfobutyl-β-cyclodextrin / carvacrol mixed solution; S3: The ε-polylysine solution of step S1 and the sulfobutyl-β-cyclodextrin / carvacrol mixed solution of step S2 were mixed and placed in a constant temperature magnetic stirring water bath, stirred at 50°C and 700 rpm for 5 hours, and freeze-dried to obtain an ε-polylysine / sulfobutyl-β-cyclodextrin / carvacrol inclusion complex; The concentration of ε-polylysine in the ε-polylysine solution is 0.5×10 -4 M; the molar ratio of ε-polylysine:sulfobutyl-β-cyclodextrin is 1:40; the mass ratio of sulfobutyl-β-cyclodextrin:carvacrol is 2:1.

[0023] Comparative Example 1: A method for preparing an ε-polylysine / sulfobutyl-β-cyclodextrin inclusion complex comprises the following steps: S1: Dissolve ε-polylysine in 7 mL of ultrapure water and adjust the pH to 5 with a 1 M HCl aqueous solution to obtain an ε-polylysine solution; S2: Dissolve sulfobutyl-β-cyclodextrin in 7 mL of ultrapure water and adjust the pH to 4 with a 1 M aqueous solution of HCl to obtain a sulfobutyl-β-cyclodextrin solution; S3: The ε-polylysine solution of step S1 and the sulfobutyl-β-cyclodextrin solution of step S2 were mixed and placed in a constant temperature magnetic stirring water bath, stirred at 50°C and 700 rpm for 5 hours, and freeze-dried to obtain an ε-polylysine / sulfobutyl-β-cyclodextrin inclusion complex; The concentration of ε-polylysine in the ε-polylysine solution is 0.5×10 -4 M; the molar ratio of ε-polylysine:sulfobutyl-β-cyclodextrin is 1:40.

[0024] Comparative Example 2: A method for preparing a sulfobutyl-β-cyclodextrin / carvacrol inclusion complex is carried out according to the following steps: S1: Dissolve sulfobutyl-β-cyclodextrin and carvacrol in 7 mL of ultrapure water, and adjust the pH to 4 with 1 M HCl aqueous solution to obtain a sulfobutyl-β-cyclodextrin / carvacrol mixed solution; S2: The sulfobutyl-β-cyclodextrin / carvacrol mixed solution of S1 was placed in a constant temperature magnetic stirring water bath, stirred at 50°C and 700 rpm for 5 h, and freeze-dried to obtain a sulfobutyl-β-cyclodextrin / carvacrol inclusion complex; The amounts of sulfobutyl-β-cyclodextrin and carvacrol are the same as those in Example 1.

[0025] Figure 1 The encapsulation efficiency and drug loading rate of the ε-polylysine / sulfobutyl-β-cyclodextrin / carvacrol inclusion complex are shown. As can be seen from the figure, the encapsulation efficiency reaches 71.07±1.83% and the drug loading rate reaches 24.65±1.37%. Figure 2 Shown is an SEM image of the ε-polylysine / sulfobutyl-β-cyclodextrin / carvacrol inclusion complex. Figure 3 The figure shows the growth and reproduction of Staphylococcus aureus and Escherichia coli in PBS containing different inclusion complexes. It can be seen from the figure that the antibacterial activity of the ε-polylysine / sulfobutyl-β-cyclodextrin / carvacrol inclusion complex is significantly better than that of the ε-polylysine / sulfobutyl-β-cyclodextrin inclusion complex and the sulfobutyl-β-cyclodextrin / carvacrol inclusion complex.

Claims

1. A method for preparing an ε-polylysine / sulfobutyl-β-cyclodextrin / carvacrol inclusion complex, characterized by: The following steps are involved: S1: dissolving ε-polylysine in ultrapure water and adjusting the pH to 5 to obtain an ε-polylysine solution; S2: dissolving sulfobutyl-β-cyclodextrin and carvacrol in ultrapure water and adjusting the pH to 4 to obtain a sulfobutyl-β-cyclodextrin / carvacrol mixed solution; S3: Mix the ε-polylysine solution and the sulfobutyl-β-cyclodextrin / carvacrol mixed solution, stir and react at 20-60° C. and 700 rpm for 2-6 hours, and freeze-dry to obtain an ε-polylysine / sulfobutyl-β-cyclodextrin / carvacrol inclusion complex.

2. The preparation method according to claim 1, wherein: The concentration of ε-polylysine in the ε-polylysine solution is 0.5×10 -4 M.

3. The preparation method according to claim 1, wherein: The molar ratio of ε-polylysine:sulfobutyl-β-cyclodextrin is 1:

40.

4. The preparation method according to claim 1, wherein: The mass ratio of sulfobutyl-β-cyclodextrin:carvacrol is 2:

1.

5. The preparation method according to claim 1, wherein: The stirring reaction temperature was 50°C and the time was 5 h.

6. An ε-polylysine / sulfobutyl-β-cyclodextrin / carvacrol inclusion complex, characterized by: Prepared by the preparation method according to any one of claims 1 to 5.

7. Use of the ε-polylysine / sulfobutyl-β-cyclodextrin / carvacrol inclusion complex according to claim 6 in the preparation of antibacterial materials.

8. The use according to claim 7, characterized in that: The antibacterial material is a material that is resistant to Gram-positive bacteria and / or Gram-negative bacteria.

9. The use according to claim 8, characterized in that: The Gram-positive bacteria is Escherichia coli, and the Gram-negative bacteria is Staphylococcus aureus.

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