CN102250342B - PEG/mPEG (Polyethylene Glycol) multi-carboxyl chemical modifying agent connected with citric acid, preparation method and application thereof in modification of toluylene compound - Google Patents

Abstract

The invention discloses a chemical modification agent of PEG/mPEG multi-carboxyl group connected with citric acid, a preparation method and an application for modifying stilbene compounds. In the present invention, PEG/mPEG-succinyl/acetyl-citric acid is used as a modifying agent to connect with stilbene compounds to prepare stilbene compound prodrugs, and the stilbene compounds involved include styrene modder , oxidized resveratrol, pterostylbene, picatanol, resveratrol, the prepared prodrugs are branched polyethylene glycol derivatives containing multiple carboxyl groups, which can be linked with multiple compounds, and can be used in many The drug loading capacity was greatly increased. In addition, the preparation method of the prodrug is simple, and can improve the water solubility and stability of the stilbene compound, increase its biological activity, and make its application range wider than that of the simple stilbene compound.

Description

Chemical modifier of PEG/mPEG polycarboxylate linked with citric acid, preparation method, and application of modified stilbene compound

technical field

The invention belongs to the field of compound preparation, and in particular relates to a chemical modifier of PEG/mPEG polycarboxylate connected with citric acid, a preparation method thereof, and the use of modifying stilbene compounds to prepare corresponding prodrugs.

Background technique

Stilbene compounds such as 3,5-dihydroxy-4-isopropyl stilbene (drug name: styrene moder), resveratrol, pterostilbene, oxidized resveratrol, piceatanol, etc. Belonging to active polyphenols, they are commonly found in the metabolites of plants or microorganisms. They have anti-inflammatory, anti-oxidation, anti-bacterial, anti-tumor, anti-free radical, anti-platelet aggregation, anti-thrombosis, anti-hyperlipidemia effects, and can be used for The prevention and treatment of fungi, eczema, arteriosclerosis, coronary heart disease, viral hepatitis, AIDS, cancer and other diseases are currently mostly used as health products. Due to the poor water solubility and stability of the above-mentioned several compounds, the bioavailability is not high, which affects their curative effect.

Chinese invention patent application 2009100710372 discloses a "hydrophilic polymer-resveratrol conjugate and preparation method", which uses monomethoxypolyethylene glycol (ie mPEG) and monomethoxypolypropylene glycol in sequence After carboxylation reaction, acyl chloride reaction, and then react with resveratrol to prepare hydrophilic resveratrol conjugates, this product has only increased water solubility, stability and biological activity compared with the original resveratrol .

The applicant's application number is 201010199655.8 Chinese invention patent application, which discloses a "PEG, mPEG chemical modifier and method for preparing resveratrol prodrug", which is based on PEG, mPEG carboxylic acid derivatives and Amino acid links to prepare PEG and mPEG chemical modifiers, and then link with resveratrol to obtain prodrugs. Compared with the aforementioned patent applications, this patent application adds amino acid molecules to the modifiers of PEG and mPEG, realizing the effect of supplementing the human body. The stilbenes also serve the purpose of supplementing amino acids. However, for the PEG modifier thus prepared, only two carboxyl groups at both ends participate in the subsequent reaction to prepare the prodrug (while only one carboxyl group at one end participates in mPEG), so the drug loading is limited, so its application will be partially limited.

Chinese invention patent CN101569748A discloses a "water-soluble paclitaxel prodrug and its preparation method and chemical modifier", which uses polyethylene glycol as a carrier, acetyl (made from tert-butyl bromoacetate), lemon The acid is used as a connecting arm, and the method for preparing the prodrug is connected with paclitaxel. In this invention, only the acetyl group is used as the connecting arm to prepare the PEG or mPEG chemical modifier, and other connecting arms, such as succinic anhydride, are not involved. In addition, this modifier is only used to modify the compound paclitaxel, and there is no research on whether it can be used to modify other small organic molecular compounds.

Contents of the invention

The technical problem to be solved by the present invention is to provide a chemical modifier of PEG/mPEG polycarboxylates connected with citric acid, a preparation method and its application for modifying stilbene compounds. The chemical modifier is not only connected by acetyl group, but also by succinyl group, so that the connection between PEG or mPEG and the linker arm is an ester bond, which is easier to remove and release after entering the body. In addition, the use of multiple carboxyl groups contained in citric acid endows the modifier with more active carboxyl groups, making it effective in modifying stilbene compounds such as stilbene modd, oxidized resveratrol, pterostylbene, piceatanol, Resveratrol can significantly increase the drug loading.

The present invention will solve above-mentioned technical problem, and the adopted technical solution is:

A kind of chemical modification agent that is connected with PEG/mPEG polycarboxylate of citric acid, its molecular structural formula is as follows:

或

，

or

,

，PEG或mPEG的分子量为2000～75000。 in

, The molecular weight of PEG or mPEG is 2000-75000.

The preparation method of the chemical modification agent is prepared by using water-soluble PEG or mPEG as a carrier, and using succinyl/acetyl and citric acid as connecting arms. Specifically, PEG/mPEG is first combined with succinic anhydride or bromine One of ethyl acetate, isobutyl bromoacetate, and tert-butyl bromoacetate reacts to obtain carboxylic acid derivatives of PEG/mPEG, then reacts with _SOCl2 to obtain PEG-acyl chloride/mPEG-acyl chloride, and finally connects with citric acid to prepare made.

The preparation methods of the above-mentioned PEG carboxylic acid derivatives or mPEG carboxylic acid derivatives are divided into two categories, wherein:

1. The carboxylic acid derivatives of PEG/mPEG are prepared by reacting water-soluble PEG/mPEG as a carrier with succinic anhydride, and the preparation method is carried out in accordance with the following steps:

① PEG/mPEG, succinic anhydride, chloroform and pyridine are heated to reflux;

② Evaporate chloroform under reduced pressure, adjust pH to 7 with saturated _NaHCO3 solution, extract with ethyl acetate, adjust pH to 2-3 with dilute hydrochloric acid;

③ extract with dichloromethane, combine the organic phases, dry, filter, concentrate the filtrate under reduced pressure, and recrystallize the concentrate with anhydrous ether to obtain carboxylic acid derivatives of PEG/mPEG;

2. The carboxylic acid derivatives of PEG/mPEG are prepared by reacting water-soluble PEG/mPEG with one of ethyl bromoacetate, isobutyl bromoacetate or tert-butyl bromoacetate. The preparation method is as follows: Follow the steps in sequence:

①Dissolve PEG or mPEG in anhydrous toluene at room temperature, and add potassium tert-butoxide in tert-butanol;

② Add one of ethyl bromoacetate, isobutyl bromoacetate or tert-butyl bromoacetate, and reflux;

③ After the reaction is finished, filter, and the filtrate is evaporated under reduced pressure to remove tert-butanol, toluene and unreacted raw materials, the residue is dissolved in dichloromethane, and recrystallized from anhydrous ether to obtain PEG carboxylate or mPEG carboxylate;

④ Dissolve the above carboxylic acid ester in distilled water, adjust the pH of the NaOH solution to 10, and stir for 30 minutes;

⑤Under cooling with ice water, use oxalic acid solution to adjust the pH of the system to 2~3, stir at room temperature for 20 min, extract with dichloromethane, combine the organic phases, wash with saturated brine until neutral, dry over anhydrous sodium sulfate, and evaporate dichloromethane under reduced pressure methane, and the residue was recrystallized with anhydrous ether to obtain carboxylic acid derivatives of PEG or mPEG.

In the preparation method of the chemical modification agent, the connection between the carboxylic acid derivative of PEG or mPEG and citric acid is carried out according to the following steps:

① Prepare the corresponding PEG or mPEG-acyl chloride

Dissolve the carboxylic acid derivative of PEG/mPEG in dichloromethane, add Py and dry SOCl ₂ at 0-5°C, react at low temperature, naturally rise to room temperature, and then heat to reflux. After the reaction is complete, concentrate to obtain PEG- acid chloride or mPEG-acyl chloride;

② Preparation of chemical modifiers

Dissolve citric acid in N,N-dimethylformamide (DMF) at room temperature, add the DMF solution of Py and PEG-acyl chloride/mPEG-acyl chloride dropwise at 0-5 °C, react at low temperature for a period of time and then naturally rise to room temperature Reaction, and finally reflux reaction, after the reaction is completed, the solvent is removed under reduced pressure, and anhydrous ether is recrystallized to obtain a chemical modifier of PEG/mPEG polycarboxylates linked with citric acid.

The present invention also provides the application of the above-mentioned PEG/mPEG multi-carboxyl chemical modifier connected with citric acid, that is, using it as a modifier to prepare a stilbene compound prodrug, and the prodrug is a multi-carboxyl branched polyethylene glycol Alcohol or monomethoxypolyethylene glycol derivatives.

The stilbene compound is one of resveratrol, phenylene modad, oxidized resveratrol, pterostylbene, and piceatanol, and their structural formulas are as follows: formula (I) ~ formula (V ):

、

、

、

、

 

,

,

,

,

The preparation method of the prodrug is carried out according to the following steps:

① The chemical modifier of PEG/mPEG polycarboxylate connected with citric acid is dissolved in dichloromethane;

②Add the DMF solution of DMAP, EDC.HCl and stilbene compounds at room temperature;

③ The solvent was concentrated under reduced pressure, and the residue was recrystallized from isopropanol to obtain a stilbene compound prodrug.

In the present invention, the molecular weight of PEG or mPEG is limited to 2000-75000, which means that both low molecular weight polymerized and high molecular weight polymerized PEG/mPEG polycarboxylates linked with citric acid are suitable for the preparation of stilbene compound prodrugs.

Owing to having adopted above-mentioned technical scheme, compared with prior art, the technological progress that the present invention obtains is:

Link polyethylene glycol or monomethoxy polyethylene glycol with citric acid to obtain branched polyethylene glycol derivatives containing multiple carboxyl groups, so that the drug loading capacity of polyethylene glycol on small molecule drugs is obvious Improvement, significantly improves the water solubility of the drug, is conducive to improving and improving the performance of the drug, significantly improves the stability of the drug, prolongs its half-life, thereby increasing its action time in the body. The preparation method of the chemical modifier provided by the invention is simple, and due to the existence of citric acid, citric acid contains multiple carboxyl groups, so that it can be applied to modify stilbene compounds such as phenylene modd, oxidized resveratrol, pterostilbene When stilbene, picatanol and resveratrol were added, the drug loading capacity of the obtained prodrug increased significantly.

Detailed ways

The following examples are only used to illustrate the present invention, not to limit the present invention.

Example 1 Preparation of PEG2000-succinoyl-citric acid-pterostilbene

 This embodiment includes the following steps:

①Preparation of PEG2000 carboxylic acid derivatives

The reaction formula is as follows:

Take 40 g (20 mmol) of dry PEG, dissolve it in 160 mL of chloroform, add 5.0 g (50 mmol) of succinic anhydride, stir well, add 3 mL of pyridine (Py), heat to reflux, react for 36 h, evaporate the solvent, The residue was dissolved in 80 mL saturated NaHCO ₃ solution, extracted with ethyl acetate (20 mL×3), cooled the water phase to 0-5 °C, adjusted the pH to 2-3 with 1 mol/L hydrochloric acid, stirred for 20 min, and extracted with dichloromethane (25 mL×4), the organic phases were combined, washed with saturated brine, dried over anhydrous sodium sulfate, concentrated under reduced pressure, and recrystallized from anhydrous ether to obtain 37.4 g of PEG2000-succinic acid as a white solid, with a yield of 85.0%;

②Synthesis of PEG2000-acyl chloride

The reaction formula is as follows:

Dissolve 5 g (2.27 mmol) of PEG2000-succinic acid in 10 mL of dichloromethane, cool down to 0-5 °C, protect with _N2 , add 5.38 g (6.81 mmol) of Py and 2.97 g (24.97 mmol) of dry SOCl ₂ , stirred at low temperature for 1 h, naturally raised to room temperature, stirred for 3 h, and then refluxed for 6 h. After the reaction was completed, the reaction was concentrated to obtain 5.08 g of PEG2000-acyl chloride, with a yield of 100%.

③ Synthesis of PEG2000 multi-carboxyl chemical modifiers linked with citric acid

The reaction formula is as follows:

At room temperature, dissolve 0.5 g (2.86 mmol) of citric acid in 3 mL of DMF, pass through _N2 protection, add 0.28 g (3.54 mmol) of Py at 0-5 °C, and simultaneously add a DMF solution of PEG-acyl chloride (3.04 g PEG-acyl chloride dissolved in prepared in 5 mL DMF), reacted for 1 h, naturally raised to room temperature for 3 h, and reacted for 6 h at 50 °C, evaporated the solvent under reduced pressure, recrystallized from anhydrous ether, and obtained the chemical modification of PEG2000 polycarboxylate linked with citric acid Agent 2.64 g, yield 76%.

④ Preparation of PEG2000-succinyl-citric acid-pterostilbene prodrug

The reaction formula is as follows:

Take 0.5 g (0.20 mmol) of PEG2000 multi-carboxyl chemical modifier linked with citric acid, dissolve it in 5 mL of dichloromethane, add the DMF solution of pterostilbene (0.36 g of pterostilbene dissolved in 6 mL of DMF), stir 30 min, add EDC.HCl 0.27 g (1.42 mmol), DMAP 1.73 g (1.42 mmol), react at room temperature for 24 h, after the reaction is completed, concentrate under reduced pressure, and recrystallize from isopropanol to obtain PEG2000-succinyl-citric acid- Pterostilbene prodrug 0.32 g, yield 40.0%.

Since the most commonly used molecular weight of PEG/mPEG as a drug carrier is 2000-75000, the present embodiment also substitutes the aforementioned PEG2000 with a molecular weight of 2000-75000 to prepare the prodrug of pterostilbene. The preparation method and process have no influence, but the feeding amount needs to be changed when the molecular weight of the carrier changes (if it is the same molar amount, the weight of the larger molecular weight will be larger), and the purpose of the invention is also achieved.

Example 2 Preparation of PEG2000-succinyl-citric acid-oxidized resveratrol

This embodiment is carried out according to the following sequence of steps:

①The preparation of PEG2000 carboxylic acid derivatives, PEG2000-acyl chlorides, and PEG2000 chemical modifiers connected with citric acid are the same as steps ①～③ in Example 1 ;

②Preparation of PEG2000-succinyl-citric acid-oxidized resveratrol prodrug

The reaction formula is as follows:

Take 0.5 g (0.20 mmol) of PEG2000 multi-carboxyl chemical modifier linked with citric acid, dissolve it in 5 mL of dichloromethane, add a DMF solution of oxidized resveratrol (0.35 g of oxidized resveratrol dissolved in 6 mL of DMF prepared in ), stirred for 30 min, added EDC.HCl 0.27 g (1.42 mmol), DMAP 1.73 g (1.42 mmol), reacted at room temperature for 24 h, after the reaction was completed, concentrated under reduced pressure, recrystallized from isopropanol to obtain PEG2000-butanediol Acyl-citric acid-oxidized resveratrol prodrug 0.30 g, yield 38.0%.

Since the most commonly used molecular weight of PEG/mPEG as a drug carrier is 2000-75000, this embodiment also replaces the aforementioned PEG2000 with PEG/mPEG with a molecular weight of 2000-75000 to prepare the prodrug of oxidized resveratrol. This change has no influence on the preparation method and process, but the charging amount needs to be changed when the molecular weight of the carrier changes, and the purpose of the invention is also achieved.

Example 3 Preparation of PEG2000-succinyl-citric acid-picetanol

This embodiment is carried out according to the following sequence of steps:

①The preparation of PEG2000 carboxylic acid derivatives, the preparation of PEG2000-acyl chloride, the preparation of the chemical modifier of PEG2000 multi-carboxyl group connected with citric acid, the method is the same as the steps ①～③ in Example 1 respectively;

② Preparation of PEG2000-succinyl-citric acid-picetanol

The reaction formula is as follows:

Take 0.5 g (0.20 mmol) PEG2000 multi-carboxyl chemical modifier linked with citric acid, dissolve it in 5 mL of dichloromethane, add the DMF solution of piceatanol (0.35 g piceatanol dissolved in 6 mL DMF) ), stirred for 30 min, added EDC.HCl 0.27 g (1.42 mmol), DMAP 1.73 g (1.42 mmol), and reacted at room temperature for 24 h. After the reaction was completed, concentrated under reduced pressure, and recrystallized from isopropanol to obtain PEG2000-succinyl -Citrate-picetanol prodrug 0.27 g, yield 34.0%.

Since the most commonly used molecular weight of PEG/mPEG as a drug carrier is 2000-75000, the present embodiment also substitutes the previously used PEG2000 with a molecular weight of PEG/mPEG in the range of 2000-75000 to prepare the prodrug of piceatanol. The change has no influence on the preparation method and process, but the charging amount needs to be changed when the molecular weight of the carrier changes, and the purpose of the invention is also achieved.

Example 4 Preparation of PEG2000-succinyl-citric acid-resveratrol

This embodiment includes the following steps:

①The preparation of PEG2000 carboxylic acid derivatives, the preparation of PEG2000-acyl chloride, and the preparation of PEG2000 chemical modifiers connected with citric acid are the same as the steps ①～③ in Example 1 ;

② Preparation of PEG2000-succinyl-citric acid-resveratrol

The reaction formula is as follows:

Take 0.5 g (0.20 mmol) of PEG2000 multi-carboxyl chemical modifier linked with citric acid, dissolve it in 5 mL of dichloromethane, add resveratrol in DMF solution (0.32 g of resveratrol dissolved in 6 mL of DMF) ), stirred for 30 min, added EDC.HCl 0.27 g (1.42 mmol), DMAP 1.73 g (1.42 mmol), and reacted at room temperature for 24 h. After the reaction was completed, concentrated under reduced pressure, and recrystallized from isopropanol to obtain PEG2000-succinyl -Citrate-resveratrol prodrug 0.27 g, yield 36.0%.

In addition, since the most commonly used molecular weight of PEG/mPEG as a drug carrier is 2000-75000, this example also replaces the previously used PEG2000 with PEG/mPEG with a molecular weight of 2000-75000 to prepare the prodrug of resveratrol, This change has no influence on the preparation method and process, but the charging amount needs to be changed when the molecular weight of the carrier changes, and the purpose of the invention is also achieved.

Example 5 Preparation of PEG2000-succinoyl-citric acid-benzylmod

This embodiment is carried out according to the following sequence of steps:

①The preparation of PEG2000 carboxylic acid derivatives, the preparation of PEG2000-acyl chloride, the preparation of the chemical modifier of PEG2000 multi-carboxyl group connected with citric acid, the method is the same as the steps ①～③ in Example 1 respectively;

② Preparation of PEG2000-succinyl-citric acid-benzylmod

The reaction formula is as follows:

Take 0.5 g (0.20 mmol) of PEG2000 multi-carboxyl chemical modifier linked with citric acid, dissolve it in 5 mL of dichloromethane, add the DMF solution of phenylene modad (0.38 g of phenylene moder dissolved in 8 mL of DMF) ), stirred for 30 min, added EDC.HCl 0.27 g (1.42 mmol), DMAP 1.73 g (1.42 mmol), and reacted at room temperature for 24 h. After the reaction was completed, concentrated under reduced pressure, and recrystallized from isopropanol to obtain PEG2000-succinyl - Citric acid-benzylmod prodrug 0.33 g, yield 41.0%.

In addition, since the most commonly used molecular weight of PEG/mPEG as a drug carrier is 2000-75000, this example also replaces the previously used PEG2000 with PEG/mPEG with a molecular weight of 2000-75000 to prepare the prodrug of phenymod. This change has no influence on the preparation method and process, but the charging amount needs to be changed when the molecular weight of the carrier changes, and the purpose of the invention is also achieved.

Example 6 Preparation of PEG2000-acetyl-citric acid-pterostilbene

①Preparation of PEG2000 carboxylic acid derivatives

The reaction formula is as follows:

Dissolve 30 g (0.15 mol) of dry PEG2000 in 300 mL of toluene, distill off 60 mL of toluene, cool down to room temperature naturally, add potassium tert-butoxide in tert-butanol solution (5.21 g potassium tert-butoxide dissolved in 30 mL tert-butoxide butanol), stirred for 1 h, added 27.05 g of ethyl bromoacetate, and refluxed for 24 h. After the reaction, filtered, the filtrate was evaporated under reduced pressure to remove tert-butanol, toluene and unreacted raw materials, and the residue was used Dichloromethane was dissolved and recrystallized from anhydrous ether to obtain 30.46 g of PEG2000-ethyl acetate with a yield of 93.5%;

Dissolve the above PEG2000-ethyl acetate in 50 mL of distilled water, adjust the pH to 10 with 0.1 mol/L NaOH solution, adjust the pH to 2-3 with 1% oxalic acid solution under ice water cooling, stir at room temperature for 20 min, extract with dichloromethane (20 mL×3), the organic phases were combined, washed with saturated brine until neutral, dried over anhydrous sodium sulfate, concentrated, and the residue was recrystallized with anhydrous ether to obtain 26.91 g of PEG2000-acetic acid, with a yield of 90.7%.

In this step of this example, ethyl bromoacetate was replaced by isobutyl bromoacetate and tert-butyl bromoacetate respectively, and PEG2000 carboxylic acid derivatives were prepared in the same way.

② Preparation of PEG2000-acyl chloride

Dissolve 5 g (2.36 mmol) of PEG2000 carboxylic acid in 20 mL of dichloromethane, cool down to 0-5 °C, pass through N ₂ for protection, add 0.56 g (7.08 mmol) of Py and 3.09 g (25.96 mmol) of dry SOCl ₂ , Reacted for 1 h, naturally rose to room temperature for 3 h, refluxed for 6 h, after the reaction was completed, concentrated to obtain 5.08 g of PEG2000-acyl chloride with a yield of 100%.

③Preparation of PEG2000-acetyl-citric acid

The reaction formula is as follows:

At room temperature, dissolve 0.5 g (2.86 mmol) of citric acid in 3 mL of DMF, pass through _N2 protection, add 0.28 g (3.54 mmol) of Py and PEG2000-acyl mLDMF), stirred for 1 h, naturally raised to room temperature and reacted for 3 h, reacted at 50 °C for 6 h, evaporated the solvent under reduced pressure, and recrystallized from anhydrous ether to obtain a chemical modifier of PEG2000 polycarboxylates linked with citric acid, 5.43 g , yield 77%.

④ Preparation of PEG2000-acetyl-citric acid-pterostilbene prodrug

Take 0.5 g (0.20 mmol) of PEG2000 multi-carboxyl chemical modifier linked with citric acid, dissolve in 5 mL of dichloromethane, add the DMF solution of pterostilbene (0.36 g of pterostilbene is dissolved in 6 mL of DMF), Stir for 30 min, add EDC.HCl 0.27 g (1.42 mmol), DMAP 1.73 g (1.42 mmol), react at room temperature for 24 h, after the reaction is completed, concentrate under reduced pressure, and recrystallize from isopropanol to obtain PEG2000-acetyl-citric acid- Pterostilbene prodrug 0.29 g, yield 37.0%.

In this example, the pterostylbene used was replaced by resveratrol, piceatanol prodrug, phenylene modad, and oxidized resveratrol in sequence, and PEG2000-acetyl-citric acid- Resveratrol prodrug, PEG2000-acetyl-citrate-picetanol prodrug, PEG2000-acetyl-citrate-benzylmod prodrug, PEG2000-acetyl-citrate-oxidized resveratrol prodrug.

In addition, since the most commonly used molecular weight of PEG/mPEG as a drug carrier is 2000-75000, this example also replaces the previously used PEG2000 with PEG/mPEG with a molecular weight of 2000-75000 to prepare the prodrug of the above compound. The change has no influence on the preparation method and process, but the charging amount needs to be changed when the molecular weight of the carrier changes, and the purpose of the invention is also achieved.

Example 7 Preparation of PEG6000-succinyl-citric acid-picetanol

This embodiment includes the following steps:

①Preparation of PEG6000 carboxylic acid derivatives

Take 30 g (0.005 mol) of dry PEG6000, dissolve it in 100 mL of chloroform, add 1.5 g (0.015 mol) of succinic anhydride, stir well, add 2 mL of pyridine (Py), heat to reflux, react for 36 h, evaporate the solvent , the residue was dissolved in 80 mL saturated NaHCO ₃ solution, extracted with ethyl acetate (20 mL×3), the water phase was cooled to 0-5 °C, and the pH was adjusted to 2-3 with 1 mol/L hydrochloric acid, and after stirring for 20 min, dichloromethane Extract (20 mL×4), combine the organic phases, wash with saturated brine until neutral, dry over anhydrous sodium sulfate, concentrate under reduced pressure, and recrystallize from anhydrous ether to obtain 26.04 g of white solid PEG6000-succinic acid, yield 84.0 %.

② Preparation of PEG6000-acyl chloride

Dissolve 5 g (0.81 mmol) of PEG6000 carboxylic acid in 50 mL of dichloromethane, cool down to 0-5 °C, add 0.19 g (2.43 mmol) of Py and 1.06 g (8.91 mmol) of dry SOCl ₂ , and react at low temperature for 1 h. Rising naturally to room temperature for 3 h, reflux for 6 h, the reaction was completed, concentrated to give PEG6000-acyl chloride, 5.05 g, yield 100%.

③ Preparation of PEG6000-succinyl-citric acid

The reaction equation is as follows:

Dissolve 0.5 g (2.86 mmol) citric acid in DMF at room temperature, add 0.28 g (3.54 mmol) Py and PEG6000-acyl chloride in DMF at 0-5 °C (prepared by dissolving 8.48 g PEG6000-acyl chloride in 10 mL of DMF solution) ), stirred for 1 h, naturally raised to room temperature and reacted for 3 h, reacted at 50 °C for 6 h, evaporated the solvent under reduced pressure, recrystallized from anhydrous ether, and obtained 7.25 g of PEG6000 chemical modifier linked with citric acid, with a yield of 81%. .

③Preparation of PEG6000-succinyl-citric acid-picetanol

The reaction equation is as follows:

Take 0.5 g (0.076 mmol) of PEG6000 chemical modifier linked with citric acid and dissolve it in 5 mL of dichloromethane, add the DMF solution of piceatanol (0.13 g of piceatanol dissolved in 5 mL of DMF solution), and stir for 30 min , add EDC.HCl 0.10 g (0.54 mmol), DMAP 0.06 g (0.54 mmol), and stir at room temperature for 24 h. After the reaction is completed, concentrate under reduced pressure, and recrystallize with isopropanol to obtain 0.21 g of piceatanol prodrug. The rate is 35%.

In this example, the Pyramid fir used was replaced by resveratrol, pterostylbene, phenylene modad, and oxidized resveratrol in turn, and PEG6000-succinyl-citric acid-resveratrol was obtained in the same way Prodrug, PEG6000-succinyl-citrate-pterostilbene prodrug, PEG6000-succinyl-citrate-benzylmod prodrug, PEG6000-succinyl-citrate-oxidized resveratrol prodrug.

In addition, since the most commonly used molecular weight of PEG/mPEG as a drug carrier is 2000-75000, this example also replaces the aforementioned PEG6000 with PEG/mPEG with a molecular weight of 2000-75000 to prepare the prodrug of the above compound. The change has no influence on the preparation method and process, but the charging amount needs to be changed when the molecular weight of the carrier changes, and the purpose of the invention is also achieved.

Example 8 Preparation method of mPEG2000-succinoyl - pterostilbene prodrug

① Preparation of mPEG2000 carboxylic acid derivatives

The reaction formula is as follows:

Take 20 g (10 mmol) of dry mPEG2000, dissolve it in 80 mL of chloroform, add 1.5 g (15 mmol) of succinic anhydride, stir well, add 1 mL of pyridine (Py), heat to reflux, react for 36 h, evaporate the solvent , the residue was dissolved in 60 mL saturated NaHCO ₃ solution, extracted with ethyl acetate (20 mL×3), the water phase was cooled to 0-5 °C, and the pH was adjusted to 2-3 with 1 mol/L hydrochloric acid, and after stirring for 20 min, dichloromethane Extract (20 mL×4), combine the organic phases, wash with saturated brine, dry over anhydrous sodium sulfate, concentrate under reduced pressure, and recrystallize from anhydrous ether to obtain 17.22 g of white solid mPEG2000-succinic acid, yield 82.0 %;

② Preparation of mPEG2000-acyl chloride

Dissolve 5 g (2.38 mmol) of PEG2000 carboxylic acid in 40 mL of dichloromethane, cool down to 0-5 °C, add 0.56 g (7.14 mmol) of Py and 3.12 g (26.18 mmol) of dry SOCl ₂ , react for 1 h, and naturally Rising to room temperature for 3 h, reflux for 6 h, the reaction was completed, and concentrated to obtain 5.04 g of PEG2000-acyl chloride, with a yield of 100%.

③ Preparation of mPEG2000-succinyl-citric acid

At room temperature, dissolve 0.5 g (2.86 mmol) of citric acid in 5 mL of DMF, add 0.28 g (3.54 mmol) of Py and mPEG2000-acyl chloride in DMF at 0-5 °C (2.88 g of mPEG2000-acyl chloride in 8 mL of DMF prepared in ), stirred for 1 h, naturally raised to room temperature, reacted for 3 h, reacted at 50 °C for 6 h, evaporated the solvent under reduced pressure, and recrystallized from anhydrous ether to obtain 2.44 g of mPEG2000 chemical modifier linked with citric acid, with a yield of 79.0 %.

④ Preparation of mPEG2000-succinyl-citric acid-pterostilbene

Dissolve 0.5 g (0.22 mmol) of mPEG2000 chemical modifier linked with citric acid in 5 mL of dichloromethane, add the DMF solution of pterostilbene (0.23 g of pterostilbene was dissolved in 5 mL of DMF), stir for 30 min, add EDC.HCl 0.17 g (0.902 mmol), DMAP 0.11 g (0.902 mmol), reacted at room temperature for 24 h, the reaction was completed, concentrated under reduced pressure, recrystallized from isopropanol to obtain mPEG2000-succinyl-citric acid-pterostilbene prodrug 0.20 g, yield 31.0%.

In this example, the pterostilbene used was replaced by resveratrol, white pine, phenylene modad, and oxidized resveratrol in turn, and mPEG2000-succinyl-citric acid-resveratrol was prepared in a similar manner Alcohol prodrug, mPEG2000-succinyl-citrate-picetanol prodrug, mPEG2000-succinyl-citrate-benzylmod prodrug, mPEG2000-succinyl-citrate-oxidized resveratrol prodrug.

In the present invention, since the most commonly used molecular weight of PEG/mPEG as a drug carrier is 2000-75000, this embodiment also replaces the aforementioned mPEG2000 with PEG/mPEG with a molecular weight of 2000-75000 to prepare the prodrug of the above compound, This change has no influence on the preparation method and process, but the charging amount needs to be changed when the molecular weight of the carrier changes, and the purpose of the invention is also achieved. the

Claims (1)

1. a kind of application of the chemical modification agent of the PEG/mPEG polycarboxyl that is connected with citric acid, the molecular structural formula of chemical modification agent is as follows:

or

, is characterized in that: it is used as modifier for modifying stilbene compound to prepare stilbene compound prodrug, and this prodrug is branched polyethylene glycol or monomethoxypolyethylene glycol derivation of polycarboxy thing; The stilbene compound is one of phenylene modad, oxidized resveratrol, pterostylbene, picatanol or resveratrol; in

, the molecular weight of PEG /mPEG is 2000～75000; It is used to prepare stilbene compound prodrugs, and the preparation method of the stilbene compound prodrugs is carried out in accordance with the following steps: ①The chemical modification agent of PEG/mPEG polycarboxylate connected with citric acid is dissolved in dichloromethane; ②Add the DMF solution of N,N-dimethylaniline, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and stilbene compounds at room temperature; ③ The solvent was concentrated under reduced pressure, and the residue was recrystallized from isopropanol to obtain a stilbene compound prodrug.