Preparation and application of amino acid isocyanate derivatives

Abstract

The application discloses preparation and application of amino acid isocyanate derivative. The amino acid isocyanate derivative containing isocyanogen, carboxylate group and different side chains is prepared through esterification, neutralization, formylation, isocyanation and saponification by taking amino acid as raw material. The preparation route is simple in operation, low in raw material cost, mild in reaction condition, novel in synthesis route, high in product yield, various in product types and good in industrial conversion prospect. The prepared amino acid isocyanate derivative can be used in preparation of polyamino acid derivative or copolymer antibacterial material, so that the single type, high price and difficulty in obtaining of commercially available isocyanate is made up, the product added value is improved, the type selection of polyamino acid derivative or copolymer is expanded, and a new direction for further improving antibacterial activity is provided.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of new material synthesis. More particularly, it relates to the preparation and application of amino acid isocyanate derivatives. BACKGROUND

[0002] So far, isocyanate compounds are a kind of chemical species which are less studied. This is not only because of their own offensive odor, but also because of the lack of a systematic and mature preparation method. As a result, there are few types of isocyanate compounds on the market, and the price is expensive, which makes it difficult to obtain, and limits the application and development of isocyanate compounds. The classical method for synthesizing isocyanate compounds is the Hofmann isocyan synthesis method. The reaction is carried out by a primary amine and chloroform in the presence of a strong base (potassium ethoxide or potassium tert-butoxide). In this reaction, dichloro carbene attacks the amino group first, followed by alpha elimination and beta elimination in turn, and finally the target product is obtained. Similarly, aromatic amines can react with sodium trichloroacetate to produce the corresponding aromatic isocyanate compounds. However, this synthesis method has poor universality and low yield.

[0003] Amino acids are organic compounds containing basic amino groups and acidic carboxyl groups, which are widely available and inexpensive. Researchers often use amino acids as starting materials to modify and obtain different types of high-value-added compounds by substituting groups. If amino acids can be used as raw materials to prepare various high-value-added isocyanate compounds, it will have great industrial value. It not only broadens the application field of amino acid synthesis, but also solves the problem of limited source of isocyanate compounds.

[0004] Therefore, it is very important to study a method for preparing isocyanate compounds from amino acids as starting materials. SUMMARY

[0005] Based on the above defects, the first object of the present application is to provide a preparation method of amino acid isocyanate derivatives. The preparation method is simple to operate, the raw material cost is low, the reaction conditions are mild, the synthesis route is novel, the product yield is high, the product variety is various, and the industrial conversion prospect is good.

[0006] The second object of the present application is to provide an amino acid isocyanate derivative prepared by the above method.

[0007] The third object of the present application is to provide an application of the above amino acid isocyanate derivative in preparing antibacterial materials. The antibacterial material is a kind of polyamino acid derivative or copolymer with alternating structure, which has a clear adjustable structure, broadens the types and structures of this kind of polymer, and has good antibacterial effect, biocompatibility and degradability.

[0008] To achieve the first object, the present application adopts the following technical scheme:

[0009] The present application discloses a preparation method of amino acid isocyanate derivative, which uses amino acid as initial raw material, and prepares amino acid isocyanate derivative through esterification, neutralization, formylation, isocyanation and saponification reactions The specific preparation process is as follows:

[0010] (1) Esterification reaction

[0011] The amino acid is added into esterification solvent X1, chlorinating agent X2 is added, and the reaction is carried out at 0-100 ℃ for 0.1-24 h, and then rotary evaporation is carried out to obtain the esterification product

[0012] (2) Neutralization reaction

[0013] The esterification product is dissolved in organic solvent X3, neutralizing agent amine A is added, and the reaction is carried out at 0-100 ℃ for 0.1-24 h, and then rotary evaporation is carried out until a large amount of solid is precipitated, low-polarity solvent is added for stirring, filtration is carried out, and the filtrate is collected and rotary evaporated to obtain the neutralization product

[0014] (3) Formylation reaction

[0015] The neutralization product is dissolved in formylation reagent B, and the reaction is carried out at 0-100 ℃ for 0.1-48 h, and then rotary evaporation is carried out to obtain the formylation product

[0016] (4) Isocyanation reaction

[0017] The formylation product is dissolved in organic solvent X4, amine X5 is added for activation, and then dehydrating agent C is added for isocyanation reaction, and the reaction is carried out at 0-100 ℃ for 0.1-12 h, and then saturated sodium bicarbonate solution and methyl tert-butyl ether are added for extraction, the organic phase is collected, and then saturated sodium bicarbonate solution and water are sequentially added for washing, and then the organic phase is dried and rotary evaporated to obtain the isocyanation product

[0018] (5) Saponification reaction

[0019] The isocyanation product is dissolved in organic solvent X6, and then lye D is added, and the reaction is carried out at 0-100 ℃ for 0.1-24 h, and then dichloromethane is added for extraction, the water layer is collected, rotary evaporation is carried out, and then freeze-drying is carried out to obtain the saponification product

[0020]

[0021] R is selected from ​​​​​​​

[0022] M is selected from Na or K.

[0023] This invention, for the first time, uses amino acids as raw materials and, through a five-step reaction process of esterification, neutralization, formylation, isocyanation, and saponification, ultimately prepares amino acid isocyanate derivatives containing isocyanate groups, carboxylate groups, and different side chains. This preparation route is simple to operate, uses inexpensive raw materials, operates under mild reaction conditions, features a novel synthetic route, achieves high product yields, produces a wide variety of products, and has promising prospects for industrial transformation. The prepared amino acid isocyanate derivatives can also be used to prepare antibacterial materials such as polyamino acid derivatives or copolymers. This not only overcomes the shortcomings of commercially available isocyanates / salts being limited in variety, expensive, and difficult to obtain, thus increasing the added value of products, but also expands the selection of polyamino acid derivatives or copolymers, providing a new direction for further improving antibacterial activity.

[0024] In step 1, since different amino acids have different side chain R1 groups, if the R1 group contains an active group, the active group is protected by a protecting group when it is sold. For example, amino groups are protected by benzyloxycarbonyl, tert-butyloxycarbonyl, or methoxycarbonyl, and hydroxyl groups are protected by benzyl or triphenylmethyl. In this isocyanate derivative preparation process, the protecting group does not participate in the reaction.

[0025] The esterification solvent X1 is an anhydrous alcohol reagent;

[0026] Furthermore, the esterification solvent X1 is selected from one or more of anhydrous methanol, anhydrous ethanol, or anhydrous isopropanol;

[0027] Furthermore, the chlorinating agent X2 is selected from thionyl chloride or phosphorus pentachloride;

[0028] Furthermore, the amino acids The molar ratio of the chlorinating agent X2 to the chlorinating agent X2 is 1:1-5;

[0029] Furthermore, the amino acids The molar ratio of amino acids to chlorinating agent X2 is 1:1.5-3; exemplarily, the amino acids... The molar ratio of the chlorinating agent X2 can also be 1:1.75, 1:2, 1:2.25, 1:2.5, 1:2.75, and any range thereof.

[0030] Furthermore, the esterification reaction is carried out at a temperature of 0-25°C for a reaction time of 4-8 hours.

[0031] In step 2, the organic solvent X3 is selected from one or more of chloroform, tetrahydrofuran, ethyl acetate, or methyl tert-butyl ether;

[0032] Furthermore, the neutralizing agent amine A is selected from one or more of triethylamine, diisopropylamine, diethylamine, or trimethylamine;

[0033] Further, the molar ratio of the esterification product to the neutralizing agent amine A is 1:1-10;

[0034] Further, the molar ratio of the esterification product to the neutralizing agent amine A is 1:1.5-3; illustratively, the molar ratio of the esterification product to the neutralizing agent amine A can also be 1:1.75, 1:2, 1:2.25, 1:2.5, 1:2.75, etc. and any interval formed thereby.

[0035] Further, the temperature of the neutralization reaction is 20-40°C and the reaction time is 2-5h.

[0036] In step 3, the formylating agent B is selected from one or more of ethyl formate, formic acid, formyl chloride or formic anhydride;

[0037] Further, the volume ratio of the neutralization product to the formylating agent B is 1:1-100;

[0038] Further, the volume ratio of the neutralization product to the formylating agent B is 1:5-20; illustratively, the volume ratio of the neutralization product to the formylating agent B can also be 1:6, 1:7, 1:8, 1:9, 1:10, 1:11, 1:12, 1:13, 1:14, 1:15, 1:16, 1:17, 1:18, 1:19, etc. and any interval formed thereby.

[0039] Further, the temperature of the formylation reaction is 45-65°C and the reaction time is 20-30h.

[0040] In step 4, the organic solvent X4 is selected from one or more of tetrahydrofuran, dichloromethane, trichloromethane or ethyl acetate;

[0041] Further, the amine X5 is selected from one or more of triethylamine, diisopropylamine, diethylamine or trimethylamine;

[0042] Further, the dehydrating agent C is selected from one or more of phosphorus oxychloride, phosgene, diphosgene, triphosgene, triphenylphosphine, methylsulfonyl chloride or oxalyl chloride;

[0043] Further, the molar ratio of the formylation product to the amine X5, the dehydrating agent C is 1:2-12: (1 / 3-2);

[0044] Further, the molar ratio of the formylation product The molar ratio of the amine X5 to the dehydrating agent C is 1:6-9:1-1.5;

[0045] Further, the temperature of the isocyanation reaction is 0-30℃, and the reaction time is 4-8h.

[0046] In step 5, the organic solvent X6 is selected from water-miscible or water-soluble solvents;

[0047] Further, the organic solvent X6 is selected from one or more of tetrahydrofuran, acetone, N,N-dimethylformamide, dimethyl sulfoxide;

[0048] Further, the alkali solution D is selected from a strong alkali solution; the strong alkali solution is selected from a sodium hydroxide solution or a potassium hydroxide solution;

[0049] Further, the isocyanation product The molar ratio of the isocyanation product to the alkali solution D is 1:1-5;

[0050] Further, the volume ratio of the organic solvent X6 to the alkali solution is 1-10:1;

[0051] Further, the temperature of the saponification reaction is 20-40℃, and the reaction time is 3-8h.

[0052] To achieve the above-mentioned second object, the application adopts the following technical scheme:

[0053] The application provides an amino acid isocyanate derivative prepared by the above method, and the amino acid isocyanate derivative is shown in formula I:

[0054]

[0055] wherein R1 is selected from

[0056] M is selected from Na or K.

[0057] To achieve the above-mentioned third object, the application adopts the following technical scheme:

[0058] The application provides an application of the amino acid isocyanate derivative in the preparation of an antibacterial material.

[0059] Further, the antibacterial material is a polyamino acid derivative or a copolymer with an alternating structure, and the structure is shown in formula II:

[0060]

[0061] wherein R1 is selected from

[0062] R2 is selected from

[0063] R3 is selected from

[0064] n is a positive integer, n = 5-100.

[0065] Those skilled in the art can understand that when the R2 group is , the corresponding is a polyamino acid copolymer, and when the R2 group is not , the corresponding is a polyamino acid derivative; the role of the R1 group is to adjust the hydrophilicity, degradability, strength, etc. of the polyamino acid derivative or copolymer material; the side chain R3 of the repeating unit carries a free amino group or carries a positive charge, which can adjust the antibacterial performance of the polyamino acid derivative or copolymer material.

[0066] In the preparation of the polyamino acid derivative or copolymer, the preparation route is prepared by one-pot method of CN110804175A, that is: the amino acid isocyanate derivative as described above is reacted with aldehyde amine under the action of acid E to occur polymerization, and then the polymerization product is deprotected to obtain;

[0067] Further, the acid E is selected from one or more of trifluoromethanesulfonic acid, methanesulfonic acid, hydrofluoric acid or trifluoroacetic acid;

[0068] Further, the molar ratio of the amino acid isocyanate derivative formula I to aldehyde amine and acid E is 1:1-2:1-2:1-2;

[0069] Further, the solvent system of the polymerization reaction is one or more of isopropyl alcohol, methanol, deionized water, dimethyl sulfoxide, N,N-dimethylformamide, tetrahydrofuran;

[0070] Further, the temperature of the polymerization reaction is 0-100℃, and the reaction time is 0.1-240h;

[0071] Further, the temperature of the polymerization reaction is 20-50℃, and the reaction time is 24-120h.

[0072] Further, the deprotection agent is selected from one or more of trifluoroacetic acid, trichloroacetic acid, benzenesulfonic acid, methanesulfonic acid, benzylthiomethane, dichlorodicyanoquinone, acetic acid;

[0073] Further, the reaction temperature of the deprotection is 0-120℃, and the reaction time is 0.1-150h;

[0074] Further, the reaction temperature of the deprotection is 40-80℃, and the reaction time is 5-20h.

[0075] The beneficial effects of the present application are as follows:

[0076] The present application first uses amino acids as raw materials, and finally prepares amino acid isocyanate derivatives containing isocyanide groups, carboxylate groups and different side chains through esterification, neutralization, formylation, isocyanation and saponification, the preparation route is simple to operate, the raw material cost is low, the reaction condition is mild, the synthetic route is novel, the product yield is high, the product variety is various, the industrial conversion prospect is good, and the prepared amino acid isocyanate derivatives can also be used to prepare polyamino acid derivatives or copolymer antibacterial materials, which not only makes up for the single type, high price and difficulty in obtaining of commercially available isocyanate, improves the added value of the product, but also expands the selection of polyamino acid derivatives or copolymer, and provides a new direction for further improving the antibacterial activity. BRIEF DESCRIPTION OF DRAWINGS

[0077] The specific embodiments of the present application will be further described in detail below with reference to the accompanying drawings.

[0078] Figure 1 The nuclear magnetic hydrogen spectrum of the esterification product, the formylation product, the isocyanation product and the saponification product of ornithine in Example 1 is shown;

[0079] Among them, a is the esterification product, b is the formylation product, c is the isocyanation product, and d is the saponification product.

[0080] Figure 2 The nuclear magnetic hydrogen spectrum of the lysine raw material and the isocyanate product in Example 2 is shown;

[0081] Among them, a is the lysine raw material, and b is the saponification product isocyanate.

[0082] Figure 3 The nuclear magnetic hydrogen spectrum of the O-benzyl-L-serine raw material and the isocyanate product in Example 3 is shown;

[0083] Among them, a is the O-benzyl-L-serine raw material, and b is the saponification product isocyanate.

[0084] Figure 4 The nuclear magnetic hydrogen spectrum of the ornithine valine alternating copolymer and its polymerization product in Example 4 is shown;

[0085] Among them, a is the polymerization product, and b is the ornithine valine alternating copolymer.

[0086] Figure 5 The cell toxicity test of the ornithine valine alternating copolymer in Example 5 is shown.

[0087] Figure 6 The performance test of the ornithine valine alternating copolymer in Example 5 against Pseudomonas aeruginosa is shown.

[0088] Figure 7 Performance testing of the ornithine valine alternating copolymer of Example 5 against Haemophilus influenzae is shown. DETAILED DESCRIPTION

[0089] In order to more clearly illustrate the application, the following further describes the application in conjunction with preferred embodiments and the accompanying drawings in which like reference numerals refer to like elements throughout. It will be understood by those skilled in the art that the following specifically described content is illustrative rather than limiting and should not be used to limit the scope of protection of the application.

[0090] Example 1

[0091] Synthesis of N'-Cbz-L-ornithine potassium isocyanate from N'-Cbz-L-ornithine (CAS: 3304-51-6)

[0092] (1) Esterification of N'-Cbz-L-ornithine: Take 5 g of N'-Cbz-L-ornithine and add 100 ml of methanol. Under ice bath conditions, add 4 ml of thionyl chloride dropwise and continue the ice bath reaction for 1 h, then warm to 65 °C and reflux for 3 h. Remove the unreacted methanol and byproducts from the reaction liquid by rotary evaporation to obtain N'-Cbz-L-ornithine methyl ester hydrochloride;

[0093] (2) Neutralization: Take 5 g of N'-Cbz-L-ornithine methyl ester hydrochloride and dissolve in 50 ml of chloroform. At room temperature, add 11 ml of triethylamine dropwise and continue the reaction for 1.5 h. Directly rotary evaporate the reaction liquid until a large amount of precipitate appears. Wash the precipitate with 50 ml of methyl tert-butyl ether three times, collect the methyl tert-butyl ether phase and rotary evaporate to obtain the product, N'-Cbz-L-ornithine methyl ester, as a light yellow oily liquid;

[0094] (3) Formylation: Take 5 g of N'-Cbz-L-ornithine methyl ester and add 30 ml of ethyl formate. Reflux at 65 °C for 24 h in an oil bath. Rotary evaporate the reaction liquid to constant weight to obtain the formylation product as a light brown oily liquid;

[0095] (4) Isocyanation: Take 5 g of the formylation product and dissolve in tetrahydrofuran. Under ice bath conditions, add 7 ml of triethylamine and 7 ml of a tetrahydrofuran solution containing 2.4 g of triphosgene dropwise. Continue the ice bath reaction for 1 h and the room temperature reaction for 2 h. Stop the reaction, add 35 ml of saturated sodium bicarbonate solution and stir. Extract with 70 ml of methyl tert-butyl ether, continue to extract the remaining aqueous layer with 50 ml of methyl tert-butyl ether, collect the organic layer, wash with 120 ml of saturated sodium bicarbonate solution, wash with 100 ml of deionized water, dry the obtained organic layer with anhydrous magnesium sulfate, and rotary evaporate to obtain the isocyanation product as a black red liquid;

[0096] (5) Saponification: Take the isocyanide product 5 g, dissolved in 50 ml of tetrahydrofuran, take 2.3 g of KOH dissolved in 25 ml of deionized water, after mixing uniformly, stirring at room temperature for 3 h. After the reaction is completed, 25 ml of deionized water is added and stirred uniformly, then 50 ml of dichloromethane is added to separate the layers, the water layer is collected, and the organic layer is washed with deionized water, then the water layers are combined, the residual organic solvent is removed by rotary evaporation, and the product is freeze-dried. The nuclear magnetic resonance chart of each stage product is shown in Figure 1 .

[0097] The specific reaction equation is shown in the following:

[0098]

[0099] In the formula, PG represents an amino protecting group: benzyloxy carbonyl.

[0100] Example 2

[0101] Nε-Cbz-L-lysine isocyanate is prepared using Nε-Cbz-L-lysine (CAS: 1155-64-2) as the raw material.

[0102] (1) Esterification of Nε-Cbz-L-lysine: Take Nε-Cbz-L-lysine 5 g, add 100 ml of methanol, and drop 4 ml of thionyl chloride under ice bath conditions. Continue the ice bath reaction for 1 h, and then heat to 65°C for reflux reaction for 3 h. Remove the unreacted methanol and by-products by rotary evaporation to obtain Nε-Cbz-L-lysine methyl ester hydrochloride;

[0103] (2) Neutralization: Take Nε-Cbz-L-lysine methyl ester hydrochloride 5 g, dissolve in chloroform, and drop 10.5 ml of triethylamine at room temperature. Continue to react for 1.5 h. The reaction liquid is directly rotary evaporated until a large amount of precipitate appears. The precipitate is washed with 50 ml of methyl tert-butyl ether three times, the methyl tert-butyl ether phase is collected, and the light yellow oily liquid product, Nε-Cbz-L-lysine methyl ester, is obtained by rotary evaporation.

[0104] (3) Formylation: Take Nε-Cbz-L-lysine methyl ester 5 g, add 30 ml of ethyl formate, and reflux at 65°C for 24 h. Rotary evaporation is performed until the weight is constant to obtain the formylation product as a light brown oily liquid.

[0105] (4) Isocyanation: Take the formylation product 5 g, dissolve in tetrahydrofuran, and drop 7 ml of triethylamine and 7 ml of a tetrahydrofuran solution containing 2.30 g of triphosgene under ice bath conditions. Continue the ice bath reaction for 1 h, and then react at room temperature for 2 h. After the reaction is stopped, 35 ml of saturated sodium bicarbonate solution is added and stirred, 70 ml of methyl tert-butyl ether is added for extraction, the remaining water layer is further extracted with 50 ml of methyl tert-butyl ether, the combined organic layer is washed with 120 ml of saturated sodium bicarbonate solution, 100 ml of deionized water, and then dried with anhydrous magnesium sulfate. The obtained organic layer is rotary evaporated to obtain the black red isocyanation product.

[0106] (5) Saponification: Take the isocyanide product 5g, dissolve in 50ml tetrahydrofuran, take 1.1g KOH dissolved in 25ml deionized water, mix uniformly, then stir at room temperature for 3h. After the reaction is completed, 25ml deionized water is added to stir uniformly, then 50ml dichloromethane is added to separate layers, the water layer is collected, and the organic layer is washed with deionized water, then the water layers are combined, the residual organic solvent is removed by rotary evaporation, and the product is freeze-dried. The nuclear magnetic resonance chart of the obtained product is shown in Figure 2 .

[0107] Example 3

[0108] O-benzyl-L-serine isocyanate is prepared from O-benzyl-L-serine (CAS. No: 4726-96-9) as raw material

[0109] (1) O-benzyl-L-serine esterification: Take O-benzyl-L-serine 5g, add 100ml methanol, and drop 5.6ml thionyl chloride under ice bath condition, continue ice bath reaction for 1h, then warm up to 65℃ and reflux for 3h. The unreacted methanol and by-products are removed by rotary evaporation to obtain O-benzyl-L-serine methyl ester hydrochloride.

[0110] (2) Neutralization: Take O-benzyl-L-serine methyl ester hydrochloride 5g, dissolve in chloroform, and drop 13ml triethylamine at room temperature, continue to react for 1.5h. The reaction liquid is directly rotary evaporated to appear a large amount of precipitate, the precipitate is washed with 50ml methyl tert-butyl ether for three times, the methyl tert-butyl ether phase is collected and rotary evaporated to obtain the yellowish oil liquid product, i.e. O-benzyl-L-serine methyl ester.

[0111] (3) Formylation: Take O-benzyl-L-serine methyl ester 5g, add 30ml ethyl formate, and reflux at 65℃ for 24h. The reaction liquid is rotary evaporated to constant weight (all unreacted ethyl formate, by-products such as ethanol are removed), and the light brown oil liquid formylation product is obtained.

[0112] (4) Isocyanation: Take the formylation product 5g, dissolve in tetrahydrofuran, drop 8ml triethylamine and 8ml tetrahydrofuran solution containing 2.92g triphosgene under ice bath condition, continue ice bath reaction for 1h, and react at room temperature for 2h. After the reaction is stopped, 40ml saturated sodium bicarbonate solution is added to stir for 5min, 80ml methyl tert-butyl ether is added to extract, the remaining water layer is continuously extracted with 50ml methyl tert-butyl ether, the combined organic layer is washed with 120ml saturated sodium bicarbonate solution, 100ml deionized water, the obtained organic layer is dried with anhydrous magnesium sulfate, and rotary evaporation is performed to obtain the black red isocyanation product.

[0113] (5) Saponification: Take the isocyanide product isocyanide 5g, dissolved in 50ml tetrahydrofuran, take 1.6g KOH dissolved in 25ml deionized water, mixed uniformly, room temperature stirring reaction 3h. After the reaction is completed, 25ml deionized water is added and stirred uniformly, and then 50ml dichloromethane is added to separate the layers. The water layer is collected, and the organic layer is washed with deionized water, and then the water layers are combined. The residual organic solvent is removed by rotary evaporation, and the product is freeze-dried. The nuclear magnetic resonance chart of the obtained product is shown in Figure 3 .

[0114] Example 4

[0115] Synthesis of ornithine valine alternating copolymer, the raw material is the saponification product potassium N'-Cbz-L-ornithine isocyanate prepared in Example 1.

[0116] Polymerization reaction: 5g of N'-Cbz-L-ornithine isocyanate potassium is added to 25ml of isopropyl alcohol at 0°C, and then 1.4ml of trifluoromethanesulfonic acid, 0.8ml of isobutyraldehyde, and 1.3ml of 1-(4-methoxyphenyl)ethylamine are added. The temperature is raised to room temperature and stirred for 4d. 25ml of water is added to the reaction solution, and 25ml of chloroform is separated into layers. The organic layer is collected by centrifugation and precipitated in 300ml of n-hexane. The water layer is purified by anion resin column chromatography and freeze-dried to obtain the polymerization product.

[0117] Deprotection reaction: 4g of the organic phase of the polymerization product is added to 40ml of trifluoroacetic acid, and the temperature is raised to 60°C and stirred for 6h. The reaction solution is precipitated in 300ml of methyl tert-butyl ether, and the precipitate is collected by centrifugation and washed with 40ml of methyl tert-butyl ether until the solvent is colorless. The precipitate is collected and dried to obtain the final product ornithine valine alternating copolymer. The nuclear magnetic resonance chart of the obtained product is shown in Figure 4 .

[0118] The reaction equation is as follows:

[0119]

[0120] Example 5

[0121] The ornithine valine alternating copolymer (Orn-Val) n of Example 4 is used as the test sample to test its cytotoxicity and antibacterial performance.

[0122] The cytotoxicity test of the ornithine valine alternating copolymer (Orn-Val) n is carried out at concentrations of 1ppm, 5ppm, 10ppm, and 50ppm, respectively, and co-cultured with mouse fibroblast cells (L929 cells) for 24h. The relative growth rate of the cells is tested, and the results are shown in Figure 5 . The cell growth rate of the sample at different concentrations is more than 90%, i.e. it has very low cytotoxicity.

[0123] Antibacterial performance test for ornithine valine alternating copolymer (Orn-Val) n After 24 hours of co-culturing with Pseudomonas aeruginosa or Klebsiella pneumoniae at 37℃ under shaking, the residual bacterial colony number and the antibacterial rate were calculated, and the results were shown in Table 1. Figure 6 and Figure 7 The sample still has an antibacterial rate of nearly 80% even at 1 ppm. Therefore, the alternating copolymer has excellent biocompatibility and antibacterial activity.

[0124] Obviously, the above embodiments of the present application are only examples for clearly illustrating the present application, and are not intended to limit the embodiments of the present application. Based on the above description, other different forms of changes or variations can be made by those skilled in the art, and it is impossible to enumerate all the embodiments here. Any obvious changes or variations derived from the technical solutions of the present application are still within the protection scope of the present application.

Claims

1. A method for producing an amino acid isocyanate derivative, characterized by, Synthesis of N'-Cbz-L-ornithine isocyanate with N'-Cbz-L-ornithine as raw material, the preparation process is as follows: (1) N'-Cbz-L-ornithine esterification: take N'-Cbz-L-ornithine 5g, and add 100ml methanol, ice bath condition, drop 4ml sulfoxide chloride, continue ice bath reaction 1h, then warm up 65℃ reflux reaction 3h, the reaction liquid is spin-evaporated to remove unreacted methanol and byproducts, obtain N'-Cbz-L-ornithine methyl ester hydrochloride; (2) neutralization: take N'-Cbz-L-ornithine methyl ester hydrochloride 5g, dissolve in 50ml chloroform, room temperature drop 11ml triethylamine, continue to react 1.5h, the reaction liquid is directly spin-evaporated to appear a large amount of precipitate, the precipitate is washed with 50ml methyl tert-butyl ether three times, collect methyl tert-butyl ether phase and spin-evaporated to obtain yellowish oil liquid product, namely N'-Cbz-L-ornithine methyl ester; (3) formylation: take N'-Cbz-L-ornithine methyl ester 5g, add 30ml ethyl formate, oil bath 65℃ reflux 24h, the reaction liquid is spin-evaporated to constant weight, obtain light brown oil liquid formylation product; (4) isocyanation: take formylation product 5g, dissolve in tetrahydrofuran, ice bath condition drop 7ml triethylamine and 2.4g triphosgene in 7ml tetrahydrofuran solution, continue ice bath reaction 1h, room temperature reaction 2h, reaction stop, add 35ml saturated sodium bicarbonate solution stirring, add 70ml methyl tert-butyl ether extraction, the remaining water layer continue to be extracted with 50ml methyl tert-butyl ether, collect organic layer, wash with 120ml saturated sodium bicarbonate solution, 100ml deionized water, the obtained organic layer is dried with anhydrous magnesium sulfate, spin-evaporated to obtain black red isocyanation product; (5) saponification: take isocyanation product 5g, dissolve in 50ml tetrahydrofuran, take 2.3g KOH dissolved in 25ml deionized water, mix uniformly, room temperature stirring reaction 3h, after reaction, add 25ml deionized water stirring uniform, then add 50ml dichloromethane, collect water layer, and wash organic layer with deionized water, then combine water layer, spin-evaporate residual organic solvent from water layer, freeze-drying, obtain.

2. A method for producing an amino acid isocyanate derivative, characterized by, Synthesis of Nε-Cbz-L-lysine isocyanate with Nε-Cbz-L-lysine as raw material, the preparation process is as follows: (1) Nε-Cbz-L-lysine esterification: take Nε-Cbz-L-lysine 5g, and add 100ml methanol, ice bath condition, drop 4ml sulfoxide chloride, continue ice bath reaction 1h, then warm up 65℃ reflux reaction 3h, the reaction liquid is spin-evaporated to remove unreacted methanol and byproducts, obtain Nε-Cbz-L-lysine methyl ester hydrochloride; (2) neutralization: take Nε-Cbz-L-lysine methyl ester hydrochloride 5g, dissolve in chloroform, room temperature drop 10.5ml triethylamine, continue to react 1.5h, the reaction liquid is directly spin-evaporated to appear a large amount of precipitate, the precipitate is washed with 50ml methyl tert-butyl ether three times, collect methyl tert-butyl ether phase and spin-evaporated to obtain yellowish oil liquid product, namely Nε-Cbz-L-lysine methyl ester; (3) Formylation: Take Nε-Cbz-L-lysine methyl ester 5g, add 30ml ethyl formate, reflux at 65°C for 24h in oil bath, spin to constant weight, get light brown oil formylation product; (4) Isocyanation: Take formylation product 5g, dissolve in tetrahydrofuran, drop 7ml triethylamine and 7ml tetrahydrofuran solution containing 2.30g triphosgene under ice bath condition, continue to react for 1h in ice bath, react for 2h at room temperature, stop reaction, add 35ml saturated sodium bicarbonate solution, stir, add 70ml methyl tert-butyl ether, extract, continue to extract the remaining water layer with 50ml methyl tert-butyl ether, collect the organic layer, wash with 120ml saturated sodium bicarbonate solution, 100ml deionized water, dry the obtained organic layer with anhydrous magnesium sulfate, spin to get black red isocyanation product; (5) Saponification: Take isocyanation product 5g, dissolve in 50ml tetrahydrofuran, take 1.1g KOH dissolved in 25ml deionized water, mix uniformly, stir at room temperature for 3h, after reaction, add 25ml deionized water, stir uniformly, add 50ml dichloromethane, separate, collect the water layer, wash the organic layer with deionized water, combine the water layer, spin to remove residual organic solvent, freeze-dry, get the product.

3. A method for producing an amino acid isocyanate derivative, characterized by, O-benzyl-L-serine isocyanate is prepared from O-benzyl-L-serine as raw material, and the preparation process is as follows: (1) O-benzyl-L-serine esterification: Take O-benzyl-L-serine 5g, add 100ml methanol, drop 5.6ml chlorosulfuric acid under ice bath condition, continue to react for 1h in ice bath, then heat to 65°C and reflux for 3h, spin to remove unreacted methanol and by-product, get O-benzyl-L-serine methyl ester hydrochloride; (2) Neutralization: Take O-benzyl-L-serine methyl ester hydrochloride 5g, dissolve in chloroform, drop 13ml triethylamine at room temperature, continue to react for 1.5h, spin the reaction liquid directly to a large amount of precipitate, wash the precipitate with 50ml methyl tert-butyl ether for three times, collect the methyl tert-butyl ether phase and spin to get light yellow oil product, which is O-benzyl-L-serine methyl ester; (3) Formylation: Take O-benzyl-L-serine methyl ester 5g, add 30ml ethyl formate, reflux at 65°C for 24h in oil bath, spin to constant weight, get light brown oil formylation product; (4) Isocyanation: Take formylation product 5g, dissolve in tetrahydrofuran, drop 8ml triethylamine and 8ml tetrahydrofuran solution containing 2.92g triphosgene under ice bath condition, continue to react for 1h in ice bath, react for 2h at room temperature, stop reaction, add 40ml saturated sodium bicarbonate solution, stir for 5min, add 80ml methyl tert-butyl ether, extract, continue to extract the remaining water layer with 50ml methyl tert-butyl ether, collect the organic layer, wash with 120ml saturated sodium bicarbonate solution, 100ml deionized water, dry the obtained organic layer with anhydrous magnesium sulfate, spin to get black red isocyanation product; (5) Saponification: Take isocyanide product isocyanide 5g, dissolved in 50ml tetrahydrofuran, take 1.6g KOH dissolved in 25ml deionized water, mixed uniformly, room temperature stirring reaction 3h, after the reaction, add 25ml deionized water stirring uniform, again add 50ml dichloromethane layer, collect water layer, and the organic layer with deionized water washing after the water layer, water layer spin evaporation to remove residual organic solvent, freeze-drying, i.e. get.

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