WO2021213086A1

WO2021213086A1 - Dextran-docosahexaenoic acid coupling polymer, synthesis method therefor and application thereof

Info

Publication number: WO2021213086A1
Application number: PCT/CN2021/081131
Authority: WO
Inventors: 师以康; 吴佳桉; 张乃宁
Original assignee: 山东大学
Priority date: 2020-04-22
Filing date: 2021-03-16
Publication date: 2021-10-28
Also published as: CN111529715B; CN111529715A

Abstract

A dextran-docosahexaenoic acid (DHA) coupling polymer, a synthesis method therefor and an application thereof, which relate to the technical field of biomedicine. The structural formula of the dextran-docosahexaenoic acid (DHA) coupling polymer is as follows: multiple DHA molecule conjugates are covalently loaded on the basis of dextran, thereby helping to improve the water solubility of DHA and thus overcoming the problem of drug administration difficulty due to the poor water solubility of DHA. At the same time, as an amphipathic drug carrier tool, same can be further coupled with other drugs to change the features of the original drugs; in addition, when encapsulating anti-tumor chemotherapy drugs, the anti-tumor effect of the drug is enhanced due to the release of DHA in the body. Meanwhile, the synthesis method is simple and easy to implement and has strong operability, and therefore has good practical application values.

Description

A kind of dextran-docosahexaenoic acid coupling polymer and its synthesis method and application

Technical field

The invention belongs to the technical field of biomedicine, and specifically relates to a dextran-docosahexaenoic acid coupling polymer and a synthesis method and application thereof.

Background technique

Disclosure of the background information is only intended to increase the understanding of the overall background of the present invention, and is not necessarily regarded as an acknowledgement or any form of suggestion that the information constitutes the prior art known to those of ordinary skill in the art.

Docosahexaenoic acid (DHA) (Figure 1) is an omega-3 polyunsaturated fatty acid (PUFAs), which has important biological functions in the human body, which can promote the development of the nervous system, participate in the regulation of insulin secretion, and relieve Inflammation, anti-tumor, alleviating side effects of drugs, enhancing the efficacy of chemotherapy drugs, etc.

The drug-polysaccharide macromolecule coupling polymer usually consists of a polymer macromolecular carrier, a small molecule drug and a connecting part. Dextran (Figure 2) is a common type of dextran, which has the advantages of cheap and easy to obtain, good water solubility, safe application, and narrow molecular weight distribution. It is commonly used as a carrier for other drug-conjugated polymers.

In clinic, many injection drugs have poor water solubility, which makes the delivery of these drugs difficult. Various delivery vehicles are needed to change their solubility.

Because many drugs have short half-lives, good therapeutic effects cannot be obtained, and large-dose injections can cause serious side effects, so it is of great significance to solve these problems of drugs.

DHA itself has the activity of inhibiting the proliferation of tumor cells and can also promote the anti-tumor effects of other chemotherapeutic drugs. The inventor found that DHA has poor water solubility and can only be taken orally in clinical practice.

Summary of the invention

The purpose of the present invention is to synthesize a dextran-docosahexaenoic acid coupling polymer and its synthesis method and application, which are based on dextran covalently loaded with multiple DHA molecule conjugates, thereby helping to improve the DHA Water solubility overcomes the difficulty of administration caused by poor water solubility of DHA. At the same time, as an amphipathic drug carrier tool, it can be further coupled with other drugs to change the characteristics of the original drug, so it has good practical application value.

In order to achieve the above objectives, the present invention adopts the following technical solutions:

In the first aspect of the present invention, there is provided a dextran-docosahexaenoic acid coupling polymer, the structural formula of the dextran-docosahexaenoic acid coupling polymer is as follows:

Wherein, n is a natural number greater than 0, and the molecular weight (Mw[weight average molecular weight]) of the dextran forming the dextran-docosahexaenoic acid coupling polymer in the present invention may be at least 100,000 Daltons.

The dextran-DHA coupling polymer of the present invention uses amino acids as the linking part to connect DHA and the macromolecular polymer backbone dextran together.

The second aspect of the present invention provides a method for synthesizing the above-mentioned dextran-docosahexaenoic acid coupling polymer. The synthesis method at least includes: using amino acids as hydrophilic linking arms; Modification; carboxymethylation of dextran with chloroacetic acid is used to obtain a polysaccharide macromolecule, and the modified DHA is connected to the polysaccharide macromolecule to obtain the dextran-DHA coupling polymer.

The third aspect of the present invention provides the application of the above-mentioned dextran-DHA coupling polymer in any of the following 1)-3):

1) DHA biological function research;

2) Development of DHA-related drugs;

3) Drug carrier or preparation of drug carrier.

Beneficial technical effects of one or more of the above technical solutions:

The above scheme uses polydextran as the drug-carrying skeleton and covalently couples multiple DHA molecules, which can effectively improve the water solubility of DHA, overcome the limitation of oral intake due to poor water solubility of DHA, and act as a kind of amphipathic The drug carrier tool can be further coupled with other drugs to change the characteristics of the original drug, such as: improving the water solubility, changing the drug’s plasma retention time, etc., and prolonging the drug’s half-life. When encapsulating anti-tumor chemotherapeutic drugs, it will be caused by DHA in the body. Release to enhance the anti-tumor effect of the drug. At the same time, the synthetic method is simple and easy to implement, and has strong operability, so it has good practical application value.

Description of the drawings

The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments and descriptions of the present invention are used to explain the present invention, and do not constitute an improper limitation of the present invention.

Figure 1 shows the structure of DHA;

Figure 2 shows the structure of dextran;

Figure 3 is the synthesis equation of compound I in Example 1 of the present invention;

Figure 4 is the synthetic route of DHA structure modification compound IV in Example 1 of the present invention;

Figure 5 is a reaction equation for synthesizing dextran structure modification compound V in Example 1 of the present invention;

Figure 6 is a reaction equation for synthesizing dextran-DHA coupling compound VI in Example 1 of the present invention.

Figure 7 is a mass spectrum of compound II in Example 1 of the present invention.

Figure 8 is a mass spectrum of compound III in Example 1 of the present invention.

Figure 9 is a mass spectrum of compound IV in Example 1 of the present invention.

Figure 10 is a hydrogen spectrum of compound V in Example 1 of the present invention.

Figure 11 is a hydrogen spectrum of compound VI in Example 1 of the present invention.

Detailed ways

It should be noted that the following detailed descriptions are all illustrative and are intended to provide further descriptions of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs.

It should be noted that the terms used here are only for describing specific embodiments, and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should also be understood that when the terms "comprising" and/or "including" are used in this specification, they indicate There are features, steps, operations, devices, components, and/or combinations thereof. It should be understood that the protection scope of the present invention is not limited to the following specific specific embodiments; it should also be understood that the terms used in the embodiments of the present invention are used to describe specific specific embodiments, not to limit the protection scope of the present invention. If the experimental methods of specific conditions are not indicated in the following specific embodiments, they usually follow the conventional methods and conditions in the art.

As mentioned earlier, DHA itself has the activity of inhibiting the proliferation of tumor cells and can also promote the anti-tumor effects of other chemotherapeutic drugs. However, DHA has poor water solubility and can only be taken orally in clinical practice.

In view of this, in a typical embodiment of the present invention, a dextran-docosahexaenoic acid coupling polymer is provided, and the structural formula of the dextran-docosahexaenoic acid coupling polymer is as follows:

The coupled polymer can not only be used as a carrier to improve the solubility of water-insoluble drugs, but also has a slow-release effect and prolongs the half-life of the drug. In addition, since the drug releases DHA in the body, when encapsulating anti-tumor chemotherapeutic drugs, the efficacy of the encapsulated drug can be improved.

Wherein, n is a natural number greater than 0, and the molecular weight (Mw[weight average molecular weight]) of the dextran forming the dextran-docosahexaenoic acid coupling polymer in the present invention may be at least 100,000 Daltons. In certain embodiments, dextran may have or at least have an Mw of 100,000, 125,000, 150,000, 200,000, 250,000, or 500,000 Daltons, or between 100,000 and 200,000, 125,000 and 175,000, 135,000 and 165,000, or 145,000 and 155,000 Daltons. Mw.

In another specific embodiment of the present invention, a method for synthesizing the above-mentioned dextran-docosahexaenoic acid coupling polymer is provided. The synthesis method at least includes: modifying the structure of DHA with an amino acid linking arm; The glycoside undergoes polysaccharide functional modification to obtain a polysaccharide macromolecule, and the modified DHA is connected to the polysaccharide macromolecule to obtain the dextran-DHA coupling polymer.

Wherein, the amino acid linking arm is preferably a lysine linking arm;

The functional modification of the polysaccharide is specifically carboxymethyl modification;

In another specific embodiment of the present invention, the method for structural modification of DHA includes:

1) DHA is activated with N-hydroxysuccinimide to synthesize the compound of formula (I).

2) The compound of formula (I) and N-α-tert-butoxycarbonyl-L-lysine undergo an amide reaction to synthesize the compound of formula (II);

3) Using ethanol and the compound represented by formula (II) to undergo an esterification reaction to synthesize the compound represented by formula (III);

4) Using HCl to remove the tert-butoxycarbonyl protecting group of the compound represented by formula (III), to synthesize the compound represented by formula (IV).

In another specific embodiment of the present invention, the use of chloroacetic acid to carboxymethylate dextran to obtain polysaccharide macromolecules specifically includes: using chloroacetic acid (ClCH ₂ COOH) to react with dextran to form an ether, and the production formula (V) The compound shown.

In another specific embodiment of the present invention, linking the modified DHA to the polysaccharide macromolecule specifically includes:

Based on the reaction between the compound represented by the formula (IV) and the compound represented by the formula (V), the compound represented by the formula (VI), that is, the dextran-DHA coupling polymer, is synthesized after coupling.

In another specific embodiment of the present invention, the application of the above-mentioned dextran-DHA coupling polymer in any of the following 1)-3) is provided:

1) DHA biological function research;

2) Development of DHA-related drugs;

3) Drug carrier or preparation of drug carrier.

In the application 2), the DHA-related drugs include anti-cancer drugs or anti-tumor drugs;

In the application 3), the drug carrier may be Nanoscale Drug Carriers.

In order to enable those skilled in the art to understand the technical solutions of the present invention more clearly, the technical solutions of the present invention will be described in detail below in conjunction with specific embodiments.

Example 1. Synthesis of Dextran-DHA

(1) Synthesis of compound (IV):

Combine 3.42g docosahexaenoic acid, 2.394g N-hydroxysuccinimide and 3.987g 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) Dissolved in 20 ml of dichloromethane (DCM), stirred for 3 hours, after the reaction was completed, extracted with saturated sodium chloride solution, collected the organic phase, and concentrated to obtain 6.4796 g of oily liquid, compound (I). Dissolve 5 g of N-α-tert-butoxycarbonyl-L-lysine in 30 ml of anhydrous N,N-dimethylformamide (DMF), add 3.082 g of triethylamine, and stir and react for 1 hour. 4.23 g of compound (I) was dissolved in 7 ml of anhydrous DMF and added to the above reaction system, and the reaction was stirred for 3 hours. With 1mol/l hydrochloric acid (adjusting pH=3.0), ethyl acetate and saturated sodium chloride were extracted, the organic phase was collected, dried with anhydrous sodium sulfate, filtered and concentrated with a rotary evaporator, and purified on a silica gel column (DCM: methanol = 1%-3%), after drying (6.6928g) a pale yellow oily liquid, compound (II). 5.36g of compound (II), 2.3522g of 4-dimethylaminopyridine (DMAP) and 3.6907g of EDC were completely dissolved in 15ml of anhydrous DMF, 50ml of ethanol was added, and the reaction was stirred for 8 hours. Evaporate the solvent to dryness, extract with ethyl acetate and saturated sodium chloride solution, collect the organic phase, and purify by silica gel column chromatography (ethyl acetate: petroleum ether = 20%-40%). After drying, 4.82 g of yellow oily liquid is obtained. (III). 6ml of absolute ethanol was added to 3ml of concentrated hydrochloric acid and mixed well, 400mg of compound (III) was added, stirred and reacted for 1 hour, and the solvent was evaporated to dryness to obtain 0.536g of brown oily liquid (IV).

(2) Synthesis of dextran-DHA

Dissolve 5 g of dextran in 30 ml of water, add 17 g of sodium hydroxide, stir for 1 hour in an ice bath, add 10.95 g of chloroacetic acid in an oil bath at 50 degrees Celsius, and stir and react for 5 hours. Continue to stir 500ml methanol, add the reaction solution dropwise to it, the system appears white flocculent precipitate, the filtered residue is dissolved in water, adjusted to pH=3.0 with hydrochloric acid, and continue to stir for 30 minutes. After concentration, the concentrated solution is dialyzed three times. After 3 hours, the molecular weight cut-off of the dialysis bag was 50,000 Daltons, and was freeze-dried to obtain 5.1 g of compound (V) as a white solid. 74 mg of compound (IV) was dissolved in 7 ml of DMF, and DIPEA was added and stirred and mixed well. 500 mg of compound (V) was dissolved in 3 ml of water, and then added to the above reaction, and the reaction was stirred for 10 hours. The reaction solution was extracted with DCM and water. The aqueous phase was collected and concentrated. The concentrated solution was dialyzed for 3 hours each time. The molecular weight cut-off of the dialysis bag was 50,000 Daltons. After freeze-drying, 450mg of compound (VI) (dextran-DHA) was obtained. .

It should be noted that the above examples are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the given examples, a person of ordinary skill in the art can modify or equivalently replace the technical solution of the present invention as needed without departing from the spirit and scope of the technical solution of the present invention.

Claims

A dextran-docosahexaenoic acid coupling polymer, characterized in that, the structural formula of the dextran-docosahexaenoic acid coupling polymer is as follows:

n is a natural number greater than zero.
The dextran-docosahexaenoic acid coupling polymer of claim 1, wherein the molecular weight of the dextran is at least 100,000 Daltons.
The dextran-docosahexaenoic acid coupling polymer of claim 1, wherein the dextran-DHA coupling polymer uses an amino acid as the linking part to connect DHA and the macromolecular polymer backbone dextran Together.
The method for synthesizing the dextran-docosahexaenoic acid coupling polymer according to any one of claims 1 to 3, wherein the method for synthesizing at least comprises: modifying the structure of DHA with an amino acid linking arm; The dextran is functionally modified to obtain a polysaccharide macromolecule, and the modified DHA is connected to the polysaccharide macromolecule to obtain the dextran-DHA coupling polymer.
The synthesis method according to claim 4, wherein the amino acid linking arm is a lysine linking arm; or, the functional modification of the polysaccharide is a carboxymethyl modification.
The method of synthesis according to claim 4, wherein the method of structural modification of DHA comprises:

1) DHA is activated with N-hydroxysuccinimide to synthesize the compound of formula (I);

2) The compound of formula (I) and N-α-tert-butoxycarbonyl-L-lysine undergo an amide reaction to synthesize the compound of formula (II);

3) Using ethanol and the compound represented by formula (II) to undergo an esterification reaction to synthesize the compound represented by formula (III);

4) Using HCl to remove the tert-butoxycarbonyl protecting group of the compound represented by formula (III) to synthesize the compound represented by formula (IV);
The synthesis method according to claim 4, characterized in that the carboxymethylation of dextran with chloroacetic acid to obtain polysaccharide macromolecules specifically comprises: using chloroacetic acid to react with dextran to form an ether, and the production formula ( V) The compound shown;
According to the claims, the modified DHA is connected to the polysaccharide macromolecule, which specifically includes:

Based on the reaction between the compound represented by the formula (IV) and the compound represented by the formula (V), the compound represented by the formula (VI), namely the dextran-DHA coupling polymer, is synthesized after coupling;
The use of the dextran-docosahexaenoic acid coupling polymer of any one of claims 1 to 3 in any of the following 1)-3):

1) DHA biological function research;

2) Development of DHA-related drugs;

3) Drug carrier or preparation of drug carrier.
The application according to claim 9, wherein, in the application 2), the DHA-related drugs include anti-cancer drugs or anti-tumor drugs;

In the application 3), the drug carrier is a nano drug carrier.