A cyclic cationic polyamino acid, preparation method and application thereof

Abstract

The present invention relates to the field of biomedicine technology, and in particular to a cyclic cationic polyamino acid, a preparation method and application thereof, wherein the cyclic cationic polyamino acid has a structure shown in Formula I. The cyclic cationic polyamino acid provided by the present invention exhibits good in vitro bactericidal effects on Gram-positive bacteria, Gram-negative bacteria and methicillin-resistant Staphylococcus aureus, as well as high selectivity, can kill bacteria quickly, and is not easy to induce bacterial resistance. The synthesized cyclic antibacterial polyamino acid can destroy the integrity of bacterial cell membranes through physical action, has rapid bactericidal kinetics, can kill more than 99% of bacteria within 30 minutes, and is not easy to induce bacterial resistance.

Description

Technical Field

[0001] The present invention relates to the field of biomedicine technology, and in particular to a cyclic cationic polyamino acid, a preparation method and application thereof. Background Art

[0002] Since the discovery of penicillin, antibiotics have played an important role in the field of antimicrobial therapy. However, due to the abuse of antibiotics, microbial resistance to antibiotics is steadily increasing, resulting in the failure of traditional antibiotics, while the research and development of new antibiotics is almost at a standstill. Therefore, there is an urgent need to develop new antimicrobial drugs with broad-spectrum antimicrobial properties and less likely to induce microbial resistance.

[0003] Antimicrobial peptides have broad-spectrum antimicrobial activity and have a strong killing effect on bacteria, especially their killing effect on certain drug-resistant pathogens has attracted people's attention. The content of antimicrobial peptides in animals is extremely low. The extraction of antimicrobial peptides from animals is low in yield, time-consuming, complex in process, and expensive, and large-scale production cannot be achieved, which has become the biggest obstacle to the practical application of antimicrobial peptides. In recent years, cationic polymers that mimic the structural characteristics of antimicrobial peptides (such as positive charge and hydrophobic structure) have shown great potential in the treatment of multidrug-resistant microbial infections. Summary of the invention

[0004] In view of this, the technical problem to be solved by the present invention is to provide a cyclic cationic polyamino acid, a preparation method and application thereof, wherein the cyclic cationic polyamino acid has high antibacterial activity.

[0005] To achieve the above object, the present invention provides a cyclic cationic polyamino acid having a structure shown in Formula I:

[0006]

[0007] Formula I;

[0008] Where n is any integer from 5 to 100;

[0009] m is any integer from 0 to 8;

[0010] R1 is -N + R2R3R4;

[0011] R2, R3, and R4 are independently selected from C1-C10 alkyl, aryl, or heteroaryl groups;

[0012] The C1-C10 alkyl, aryl or heteroaryl group may be optionally substituted by one or more substituents selected from halogen, aryl or heteroaryl groups.

[0013] The n is any integer between 5 and 100. In some specific embodiments of the present invention, the n is 5, 10, 25, 40, 70 or 100, or a range value with any of the above values ​​as the upper limit or lower limit.

[0014] The m is any integer from 0 to 8. Preferably, the m is any integer from 1 to 6. Further preferably, the m is any integer from 1 to 4. In some specific embodiments of the present invention, the m is 1, 2, 3 or 4.

[0015] The R2, R3, and R4 are independently selected from C1-C10 alkyl, aryl, or heteroaryl groups; preferably, the R2, R3, and R4 are independently selected from C1-C10 alkyl, phenyl, fused aryl formed by 2-3 phenyl groups, or 5-membered to 6-membered monocyclic heteroaryl groups; more preferably, the R2, R3, and R4 are independently selected from C1-C10 alkyl, phenyl, or naphthyl groups. In some specific embodiments of the present invention, any one or two of the R2, R3, and R4 are selected from C1-C3 alkyl groups, and further, any one or two of the R2, R3, and R4 are selected from methyl groups.

[0016] Preferably, the R2, R3, and R4 may be optionally substituted with one or more substituents selected from halogen, aryl or heteroaryl; more preferably, the R2, R3, and R4 may be optionally substituted with one or more substituents selected from halogen, phenyl, a fused ring aryl formed by 2 to 3 phenyl groups, or a five-membered to six-membered monocyclic heteroaryl; further preferably, the R2, R3, and R4 may be optionally substituted with one or more substituents selected from halogen, phenyl or naphthyl.

[0017] In some specific embodiments of the present invention, the R1 is selected from the structure shown in Formula II, Formula III, Formula IV, Formula V or Formula VI:

[0018]

[0019] In Formula II, x is any integer from 1 to 9. In some specific embodiments of the present invention, x is 1, 3, 5, 7, 9, or a range value with the above values ​​as the upper or lower limit.

[0020] Curved lines indicate connection locations.

[0021] The cyclic polyamino acid material provided by the present invention can simulate the structural characteristics of antimicrobial peptide drugs. Compared with linear antimicrobial peptides, the cyclic antimicrobial polyamino acid material has stronger antimicrobial effect, higher stability, lower toxicity and better biocompatibility. In addition, the cyclic polyamino acid material provided by the present invention has the advantages of being easy to synthesize and modify.

[0022] The present invention provides a method for preparing the above-mentioned cyclic cationic polyamino acid, comprising the following steps:

[0023] A cyclic poly (chloroalkyl L-glutamic acid ester) having a structure of Formula VII and a tertiary amine NR2R3R4 are subjected to a substitution reaction to obtain a cyclic polyamino acid antibacterial material having a structure of Formula I;

[0024]

[0025] Where n is any integer from 5 to 100;

[0026] m is any integer from 0 to 8;

[0027] R1 is -N + R2R3R4;

[0028] R2, R3, and R4 are independently selected from C1-C10 alkyl, aryl, or heteroaryl groups;

[0029] The C1-C10 alkyl, aryl or heteroaryl group may be optionally substituted by one or more substituents selected from halogen, aryl or heteroaryl groups.

[0030] The ranges of n and m in the cyclic poly(chloroalkyl L-glutamic acid ester) structure of the above formula VII are the same as those described above and will not be repeated here.

[0031] In some specific embodiments of the present invention, the cyclic poly(chloroalkyl L-glutamate) of the formula VII is cyclic poly(chlorohexyl L-glutamate) or cyclic poly(chloropropyl L-glutamate).

[0032] In the above-mentioned tertiary amine NR2R3R4, the ranges of R2, R3 and R4 are the same as those described above and will not be repeated here.

[0033] In some specific embodiments of the present invention, the tertiary amine NR2R3R4 has any of the following structures:

[0034] .

[0035] x is any integer from 1 to 9.

[0036] The range of x is the same as described above and will not be repeated here.

[0037] The present invention has no particular limitation on the source of the tertiary amine, which can be any commercially available one.

[0038] The molar ratio of the total number of chlorine atoms contained in the cyclic poly (chloroalkyl L-glutamate) side group to the tertiary amine is preferably 1:1-5. In some specific embodiments of the present invention, the molar ratio is 1:1, 1:2, 1:3, 1:4 or 1:5.

[0039] The solvent for the substitution reaction preferably includes one or more of tetrahydrofuran, acetonitrile, dimethyl sulfoxide, N,N-dimethylformamide and N-methylpyrrolidone.

[0040] The present invention has no particular limitation on the amount of the solvent used, and any amount of the solvent used can dissolve the reaction raw materials.

[0041] The temperature of the substitution reaction is preferably 40-100° C., more preferably 70° C.; the time of the substitution reaction is preferably 12-72 h, more preferably 24 h.

[0042] In some specific embodiments of the present invention, after the above substitution reaction is completed, the following steps are further included:

[0043] The product solution after the reaction is dialyzed and freeze-dried to obtain a cyclic cationic polyamino acid having the structure of formula (I).

[0044] The present invention has no particular limitation on the dialysis and lyophilization methods, and any dialysis and lyophilization methods well known to those skilled in the art may be used.

[0045] The present invention has no particular limitation on the preparation method of the cyclic poly (chloroalkyl L-glutamic acid ester) represented by the above formula VII, and the cyclic poly (chloroalkyl L-glutamic acid ester) can be prepared according to methods well known to those skilled in the art. Preferably, the cyclic poly (chloroalkyl L-glutamic acid ester) can be prepared according to the following method:

[0046] L-glutamic acid chloroalkyl ester-N-carboxyl cyclic anhydride represented by formula VIII undergoes a ring-opening polymerization reaction under the action of an initiator represented by formula IX to obtain a cyclic poly(L-glutamic acid chloroalkyl ester) represented by formula VII;

[0047]

[0048] Wherein, m is any integer from 0 to 8.

[0049] The range of m is the same as described above and will not be repeated here.

[0050] The solvent for the ring-opening polymerization reaction preferably includes one or more of anhydrous tetrahydrofuran, anhydrous N,N-dimethylformamide and N-methylpyrrolidone.

[0051] The present invention has no particular limitation on the source of the initiator 1,3-diisopropylimidazolium bicarbonate represented by the formula IX, and it can be a commercially available one.

[0052] The molar ratio of the L-glutamic acid chloroalkyl ester-N-carboxyl cyclic anhydride represented by the formula VIII to the initiator represented by the formula IX is preferably 5 to 200:1, more preferably 5 to 100:1.

[0053] The ratio of the total mass of the L-glutamic acid chloroalkyl ester-N-carboxyl cyclic anhydride represented by the above formula VIII and the initiator represented by the above formula IX to the volume of the solvent is preferably 1.0~20.0 g:100~300 mL. In some specific embodiments of the present invention, the above ratio is specifically 1.1 g:250 mL, 2.06 g:250 mL, 4.96 g:250 mL, 7.82 g:250 mL, 13.58 g:250 mL, and 19.36 g:250 mL.

[0054] The present invention has no particular limitation on the source of the L-glutamic acid chloroalkyl ester-N-carboxyl ring anhydride represented by the above formula VIII. Optionally, the L-glutamic acid chloroalkyl ester-N-carboxyl ring anhydride represented by the formula VIII is synthesized according to the method described in the document Song Z, Zheng N, Ba X, Yin L, Zhang R, Ma L, Cheng J. Polypeptides with quaternary phosphonium side chains: synthesis, characterization, and cell-penetrating properties. Biomacromolecules 2014, 15:1491. published by Cheng Jianjun et al.

[0055] The temperature of the ring-opening polymerization reaction is preferably 10-60° C., more preferably 20-25° C., and further preferably 25° C.; the time of the ring-opening polymerization reaction is preferably 1-7 days, more preferably 3-5 days, and further preferably 3 days.

[0056] In some specific embodiments of the present invention, after the ring-opening polymerization reaction is completed, the following steps are further included:

[0057] The product after the reaction is dialyzed and freeze-dried to obtain a cyclic poly(chloroalkyl L-glutamate) having a structure of formula (VII).

[0058] The present invention has no particular limitation on the dialysis and lyophilization methods, and any dialysis and lyophilization methods well known to those skilled in the art may be used.

[0059] The cyclic cationic polyamino acid provided by the present invention has excellent antibacterial activity and high selectivity against Gram-positive bacteria Staphylococcus aureus (S. aureus) and Gram-negative bacteria Escherichia coli (E. coli), and can destroy the integrity of bacterial cell membranes through physical interaction, showing the characteristics of rapid bacterial killing. The cyclic cationic polyamino acid provided by the present invention can suppress the survival rate of multiple bacteria to less than 1% within 30 minutes.

[0060] Based on this, the present invention provides the use of the above-mentioned cyclic cationic polyamino acid or the cyclic cationic polyamino acid prepared by the above-mentioned preparation method as an antibacterial material.

[0061] Compared with the prior art, the present invention provides a cyclic cationic polyamino acid having a structure shown in formula I.

[0062] The cyclic cationic polyamino acid provided by the present invention exhibits good in vitro bactericidal effects on Gram-positive bacteria, Gram-negative bacteria and methicillin-resistant Staphylococcus aureus, as well as high selectivity, can kill bacteria quickly, and is not easy to induce bacterial resistance. The synthesized cyclic antibacterial polyamino acid can destroy the integrity of bacterial cell membranes through physical action, has rapid bactericidal kinetics, can kill more than 99% of bacteria within 30 minutes, and is not easy to induce bacterial resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Figure 1 This is the hydrogen nuclear magnetic resonance spectrum of the cyclic cationic polyamino acid prepared in Example 15 of the present invention;

[0064] Figure 2 This is a bacterial morphology diagram after Staphylococcus aureus and Escherichia coli are treated with the cyclic cationic polyamino acid prepared in Example 15 of the present invention;

[0065] Figure 3 This is a diagram showing the bactericidal kinetics of the cyclic cationic polyamino acid prepared in Example 15 of the present invention against Staphylococcus aureus and Escherichia coli;

[0066] Figure 4 This is a bar graph of the survival rate of L929 cells after being treated with different concentrations of the cyclic cationic polyamino acid prepared in Example 15 of the present invention;

[0067] Figure 5 It is a bar chart drawn according to Table 1, that is, the minimum inhibitory concentration of the cyclic cationic polyamino acids prepared in Examples 7 to 60 of the present invention against Staphylococcus aureus and Escherichia coli. DETAILED DESCRIPTION

[0068] In order to further illustrate the present invention, the following is a detailed description in conjunction with the embodiments. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the invention.

[0069] All raw materials of the present invention have no particular limitation on their sources, and can be purchased from the market or prepared according to conventional methods known to those skilled in the art.

[0070] The standard strains of Staphylococcus aureus (ATCC 25923) and Escherichia coli (ATCC 25922) were purchased from Shandong Lu Microbiological Technology Co., Ltd. Methicillin-resistant Staphylococcus aureus (MRSA ATCC 43300) was provided by the First Clinical Hospital of Jilin University.

[0071] Example 1

[0072] Synthesis of cyclic poly(chlorohexyl L-glutamate) or cyclic poly(chloropropyl L-glutamate) having the structure of formula (VII), wherein n=5:

[0073] 0.14 g (0.66 mmol) of 1,3-diisopropylimidazolium bicarbonate was weighed and dissolved in 100 mL of anhydrous DMF, and then 0.96 g (3.27 mmol) of compound (XIII) L-glutamic acid chlorohexyl ester-N-carboxyl cyclic anhydride or L-glutamic acid chloropropyl ester-N-carboxyl cyclic anhydride dissolved in 150 mL of anhydrous DMF was quickly added thereto. After stirring at 25°C for 72 h, the mixture was dialyzed and freeze-dried to obtain a white powder product, cyclic poly (L-glutamic acid chlorohexyl ester) or cyclic poly (L-glutamic acid chloropropyl ester).

[0074] Example 2

[0075] Synthesis of cyclic poly(chlorohexyl L-glutamate) or cyclic poly(chloropropyl L-glutamate) having the structure of formula (VII), wherein n=10:

[0076] 0.14 g (0.66 mmol) of 1,3-diisopropylimidazolium bicarbonate was weighed and dissolved in 100 mL of anhydrous DMF, and then 1.92 g (6.54 mmol) of compound (XIII) L-glutamic acid chlorohexyl ester-N-carboxyl cyclic anhydride or L-glutamic acid chloropropyl ester-N-carboxyl cyclic anhydride dissolved in 150 mL of anhydrous DMF was quickly added thereto. After stirring at 25°C for 72 h, the mixture was dialyzed and freeze-dried to obtain a white powder product, cyclic poly (L-glutamic acid chlorohexyl ester) or cyclic poly (L-glutamic acid chloropropyl ester).

[0077] Example 3

[0078] Synthesis of cyclic poly(chlorohexyl L-glutamate) or cyclic poly(chloropropyl L-glutamate) having the structure of formula (VII), wherein n=25:

[0079] 0.14 g (0.66 mmol) of 1,3-diisopropylimidazolium bicarbonate was weighed and dissolved in 100 mL of anhydrous DMF, and then 4.80 g (16.35 mmol) of compound (XIII) L-glutamic acid chlorohexyl ester-N-carboxyl cyclic anhydride or L-glutamic acid chloropropyl ester-N-carboxyl cyclic anhydride dissolved in 150 mL of anhydrous DMF was quickly added thereto. After stirring at 25°C for 72 h, the mixture was dialyzed and freeze-dried to obtain a white powder product, cyclic poly (L-glutamic acid chlorohexyl ester) or cyclic poly (L-glutamic acid chloropropyl ester).

[0080] Example 4

[0081] Synthesis of cyclic poly(chlorohexyl L-glutamate) or cyclic poly(chloropropyl L-glutamate) having the structure of formula (VII), wherein n=40:

[0082] 0.14 g (0.66 mmol) of 1,3-diisopropylimidazolium bicarbonate was weighed and dissolved in 100 mL of anhydrous DMF, and then 7.68 g (26.16 mmol) of compound (XIII) L-glutamic acid chlorohexyl ester-N-carboxyl cyclic anhydride or L-glutamic acid chloropropyl ester-N-carboxyl cyclic anhydride dissolved in 150 mL of anhydrous DMF was quickly added thereto. After stirring at 25°C for 72 h, the mixture was dialyzed and freeze-dried to obtain a white powder product, cyclic poly (L-glutamic acid chlorohexyl ester) or cyclic poly (L-glutamic acid chloropropyl ester).

[0083] Example 5

[0084] Synthesis of cyclic poly(chlorohexyl L-glutamate) or cyclic poly(chloropropyl L-glutamate) having the structure of formula (VII), wherein n=70:

[0085] 0.14 g (0.66 mmol) of 1,3-diisopropylimidazolium bicarbonate was weighed and dissolved in 100 mL of anhydrous DMF, and then 13.44 g (45.78 mmol) of compound (XIII) L-glutamic acid chlorohexyl ester-N-carboxyl cyclic anhydride or L-glutamic acid chloropropyl ester-N-carboxyl cyclic anhydride dissolved in 150 mL of anhydrous DMF was quickly added thereto. After stirring and reacting at 25°C for 72 h, the mixture was dialyzed and freeze-dried to obtain a white powder product, cyclic poly (L-glutamic acid chlorohexyl ester) or cyclic poly (L-glutamic acid chloropropyl ester).

[0086] Example 6

[0087] Synthesis of cyclic poly(chlorohexyl L-glutamate) or cyclic poly(chloropropyl L-glutamate) having the structure of formula (VII), wherein n=100:

[0088] 0.14 g (0.66 mmol) of 1,3-diisopropylimidazolium bicarbonate was weighed and dissolved in 100 mL of anhydrous DMF, and then 19.20 g (65.40 mmol) of compound (XIII) L-glutamic acid chlorohexyl ester-N-carboxyl cyclic anhydride or L-glutamic acid chloropropyl ester-N-carboxyl cyclic anhydride dissolved in 150 mL of anhydrous DMF was quickly added thereto. After stirring and reacting at 25°C for 72 hours, the mixture was dialyzed and freeze-dried to obtain a white powder product, cyclic poly (L-glutamic acid chlorohexyl ester) or cyclic poly (L-glutamic acid chloropropyl ester).

[0089] Example 7

[0090] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=5:

[0091] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 1, then add 0.355 g (4.86 mmol) of N, N-dimethylethylamine and 0.728 g (4.86 mmol) of sodium iodide, then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0092] Example 8

[0093] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=5:

[0094] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 1, then add 0.492 g (4.86 mmol) of N, N-dimethylbutylamine and 0.728 g (4.86 mmol) of sodium iodide, then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0095] Example 9

[0096] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=5:

[0097] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 1, then add 0.628 g (4.86 mmol) of N, N-dimethylhexylamine and 0.728 g (4.86 mmol) of sodium iodide, and then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0098] Example 10

[0099] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=5:

[0100] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 1, then add 0.764 g (4.86 mmol) of N, N-dimethyl-n-octylamine and 0.728 g (4.86 mmol) of sodium iodide, and then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0101] Embodiment 11

[0102] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=5:

[0103] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 1, then add 0.900 g (4.86 mmol) of N, N-dimethyldecylamine and 0.728 g (4.86 mmol) of sodium iodide, then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0104] Example 12

[0105] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=10:

[0106] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 2, then add 0.355 g (4.86 mmol) of N, N-dimethylethylamine and 0.728 g (4.86 mmol) of sodium iodide, then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0107] Embodiment 13

[0108] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=10:

[0109] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 2, then add 0.492 g (4.86 mmol) of N, N-dimethylbutylamine and 0.728 g (4.86 mmol) of sodium iodide, then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0110] Embodiment 14

[0111] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=10:

[0112] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 2, then add 0.628 g (4.86 mmol) of N, N-dimethylhexylamine and 0.728 g (4.86 mmol) of sodium iodide, then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0113] Embodiment 15

[0114] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=10:

[0115] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 2, then add 0.764 g (4.86 mmol) of N, N-dimethyl-n-octylamine and 0.728 g (4.86 mmol) of sodium iodide, and then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0116] Example 16

[0117] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=10:

[0118] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 2, then add 0.900 g (4.86 mmol) of N, N-dimethyldecylamine and 0.728 g (4.86 mmol) of sodium iodide, then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0119] Embodiment 17

[0120] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=25:

[0121] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 3, then add 0.355 g (4.86 mmol) of N, N-dimethylethylamine and 0.728 g (4.86 mmol) of sodium iodide, then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0122] Embodiment 18

[0123] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=25:

[0124] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 3, then add 0.492 g (4.86 mmol) of N, N-dimethylbutylamine and 0.728 g (4.86 mmol) of sodium iodide, then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0125] Embodiment 19

[0126] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=25:

[0127] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 3, then add 0.628 g (4.86 mmol) of N, N-dimethylhexylamine and 0.728 g (4.86 mmol) of sodium iodide, then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0128] Embodiment 20

[0129] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=25:

[0130] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 3, then add 0.764 g (4.86 mmol) of N, N-dimethyl-n-octylamine and 0.728 g (4.86 mmol) of sodium iodide, and then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0131] Embodiment 21

[0132] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=25:

[0133] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 3, then add 0.900 g (4.86 mmol) of N, N-dimethyldecylamine and 0.728 g (4.86 mmol) of sodium iodide, then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0134] Embodiment 22

[0135] Synthesis of a cyclic cationic polyamino acid having a structure of formula (I), wherein n=40:

[0136] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 4, then add 0.355 g (4.86 mmol) of N, N-dimethylethylamine and 0.728 g (4.86 mmol) of sodium iodide, then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0137] Embodiment 23

[0138] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=40:

[0139] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 4, then add 0.492 g (4.86 mmol) of N, N-dimethylbutylamine and 0.728 g (4.86 mmol) of sodium iodide, then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0140] Embodiment 24

[0141] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=40:

[0142] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 4, then add 0.628 g (4.86 mmol) of N, N-dimethylhexylamine and 0.728 g (4.86 mmol) of sodium iodide, then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0143] Embodiment 25

[0144] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=40:

[0145] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 4, then add 0.764 g (4.86 mmol) of N, N-dimethyl-n-octylamine and 0.728 g (4.86 mmol) of sodium iodide, then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0146] Embodiment 26

[0147] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=40:

[0148] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 4, then add 0.900 g (4.86 mmol) of N, N-dimethyldecylamine and 0.728 g (4.86 mmol) of sodium iodide, then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0149] Embodiment 27

[0150] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=70:

[0151] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 5, then add 0.355 g (4.86 mmol) of N, N-dimethylethylamine and 0.728 g (4.86 mmol) of sodium iodide, then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0152] Embodiment 28

[0153] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=70:

[0154] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 5, then add 0.492 g (4.86 mmol) of N, N-dimethylbutylamine and 0.728 g (4.86 mmol) of sodium iodide, then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0155] Embodiment 29

[0156] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=70:

[0157] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 5, then add 0.628 g (4.86 mmol) of N, N-dimethylhexylamine and 0.728 g (4.86 mmol) of sodium iodide, then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0158] Embodiment 30

[0159] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=70:

[0160] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 5, then add 0.764 g (4.86 mmol) of N, N-dimethyl-n-octylamine and 0.728 g (4.86 mmol) of sodium iodide, then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0161] Embodiment 31

[0162] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=70:

[0163] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 5, then add 0.900 g (4.86 mmol) of N, N-dimethyldecylamine and 0.728 g (4.86 mmol) of sodium iodide, then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0164] Embodiment 32

[0165] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=100:

[0166] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 6, then add 0.355 g (4.86 mmol) of N, N-dimethylethylamine and 0.728 g (4.86 mmol) of sodium iodide, then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0167] Embodiment 33

[0168] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=100:

[0169] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 6, then add 0.492 g (4.86 mmol) of N, N-dimethylbutylamine and 0.728 g (4.86 mmol) of sodium iodide, then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0170] Embodiment 34

[0171] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=100:

[0172] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 6, then add 0.628 g (4.86 mmol) of N, N-dimethylhexylamine and 0.728 g (4.86 mmol) of sodium iodide, then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0173] Embodiment 35

[0174] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=100:

[0175] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 6, then add 0.764 g (4.86 mmol) of N, N-dimethyloctylamine and 0.728 g (4.86 mmol) of sodium iodide, then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0176] Embodiment 36

[0177] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=100:

[0178] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 6, then add 0.900 g (4.86 mmol) of N, N-dimethyldecylamine and 0.728 g (4.86 mmol) of sodium iodide, then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0179] Embodiment 37

[0180] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=5:

[0181] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 1, then add 0.832 g (4.86 mmol) of N,N-dimethyl-2-naphthylamine and 0.728 g (4.86 mmol) of sodium iodide, then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0182] Embodiment 38

[0183] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=5:

[0184] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 1, then add 0.900 g (4.86 mmol) of N,N-dimethyl-1 (naphthalene-1-yl) methylamine and 0.728 g (4.86 mmol) of sodium iodide, then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0185] Embodiment 39

[0186] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=5:

[0187] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 1, then add 0.657 g (4.86 mmol) of N, N-dimethylbenzylamine and 0.728 g (4.86 mmol) of sodium iodide, then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0188] Embodiment 40

[0189] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=5:

[0190] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 1, then add 0.725 g (4.86 mmol) of N,N-dimethyl-2-phenylethylamine and 0.728 g (4.86 mmol) of sodium iodide, and then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0191] Embodiment 41

[0192] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=10:

[0193] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 2, then add 0.832 g (4.86 mmol) of N,N-dimethyl-2-naphthylamine and 0.728 g (4.86 mmol) of sodium iodide, then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0194] Embodiment 42

[0195] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=10:

[0196] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 2, then add 0.900 g (4.86 mmol) of N,N-dimethyl-1 (naphthalene-1-yl) methylamine and 0.728 g (4.86 mmol) of sodium iodide, then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0197] Embodiment 43

[0198] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=10:

[0199] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 2, then add 0.657 g (4.86 mmol) of N, N-dimethylbenzylamine and 0.728 g (4.86 mmol) of sodium iodide, then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0200] Embodiment 44

[0201] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=10:

[0202] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 2, then add 0.725 g (4.86 mmol) of N,N-dimethyl-2-phenylethylamine and 0.728 g (4.86 mmol) of sodium iodide, then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0203] Embodiment 45

[0204] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=25:

[0205] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 3, then add 0.832 g (4.86 mmol) of N,N-dimethyl-2-naphthylamine and 0.728 g (4.86 mmol) of sodium iodide, then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0206] Embodiment 46

[0207] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=25:

[0208] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 3, then add 0.900 g (4.86 mmol) of N,N-dimethyl-1 (naphthalene-1-yl) methylamine and 0.728 g (4.86 mmol) of sodium iodide, then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0209] Embodiment 47

[0210] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=25:

[0211] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 3, then add 0.657 g (4.86 mmol) of N, N-dimethylbenzylamine and 0.728 g (4.86 mmol) of sodium iodide, then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0212] Embodiment 48

[0213] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=25:

[0214] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 3, then add 0.725 g (4.86 mmol) of N,N-dimethyl-2-phenylethylamine and 0.728 g (4.86 mmol) of sodium iodide, then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0215] Embodiment 49

[0216] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=40:

[0217] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 4, then add 0.832 g (4.86 mmol) of N,N-dimethyl-2-naphthylamine and 0.728 g (4.86 mmol) of sodium iodide, then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0218] Embodiment 50

[0219] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=40:

[0220] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 4, then add 0.900 g (4.86 mmol) of N,N-dimethyl-1 (naphthalene-1-yl) methylamine and 0.728 g (4.86 mmol) of sodium iodide, then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0221] Embodiment 51

[0222] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=40:

[0223] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 4, then add 0.657 g (4.86 mmol) of N, N-dimethylbenzylamine and 0.728 g (4.86 mmol) of sodium iodide, then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0224] Embodiment 52

[0225] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=40:

[0226] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 4, then add 0.725 g (4.86 mmol) of N,N-dimethyl-2-phenylethylamine and 0.728 g (4.86 mmol) of sodium iodide, then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0227] Embodiment 53

[0228] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=70:

[0229] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 5, then add 0.832 g (4.86 mmol) of N,N-dimethyl-2-naphthylamine and 0.728 g (4.86 mmol) of sodium iodide, then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0230] Embodiment 54

[0231] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=70:

[0232] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 5, then add 0.900 g (4.86 mmol) of N,N-dimethyl-1 (naphthalene-1-yl) methylamine and 0.728 g (4.86 mmol) of sodium iodide, then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0233] Embodiment 55

[0234] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=70:

[0235] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 5, then add 0.657 g (4.86 mmol) of N, N-dimethylbenzylamine and 0.728 g (4.86 mmol) of sodium iodide, then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0236] Embodiment 56

[0237] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=70:

[0238] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 5, then add 0.725 g (4.86 mmol) of N,N-dimethyl-2-phenylethylamine and 0.728 g (4.86 mmol) of sodium iodide, then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0239] Embodiment 57

[0240] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=100:

[0241] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 6, then add 0.832 g (4.86 mmol) of N,N-dimethyl-2-naphthylamine and 0.728 g (4.86 mmol) of sodium iodide, then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0242] Embodiment 58

[0243] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=100:

[0244] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 6, then add 0.900 g (4.86 mmol) of N,N-dimethyl-1 (naphthalene-1-yl) methylamine and 0.728 g (4.86 mmol) of sodium iodide, then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0245] Embodiment 59

[0246] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=100:

[0247] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 6, then add 0.657 g (4.86 mmol) of N, N-dimethylbenzylamine and 0.728 g (4.86 mmol) of sodium iodide, then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0248] Embodiment 60

[0249] Synthesis of a cyclic cationic polyamino acid having the structure of formula (I), wherein n=100:

[0250] Weigh 0.40 g (the side groups contain 1.62 mmol of chlorine atoms in total) of the cyclic poly (chlorohexyl L-glutamate) or cyclic poly (chloropropyl L-glutamate) obtained in Example 6, then add 0.725 g (4.86 mmol) of N,N-dimethyl-2-phenylethylamine and 0.728 g (4.86 mmol) of sodium iodide, then add 5 mL of anhydrous DMF and 5 mL of anhydrous acetonitrile and stir until dissolved, seal and react at 70 ° C for 48 h. After the reaction stops, dialyze and freeze-dry to obtain a white powdery antibacterial polyamino acid material.

[0251] Detection Example

[0252] The polyamino acid materials having the structures of formula (I) and formula (VII) obtained in the above examples of the present invention were tested.

[0253] See also Figure 1 , Figure 1 This is the hydrogen nuclear magnetic resonance spectrum of the cationic polyamino acid prepared in Example 15 of the present invention. Figure 1 It can be seen that the side groups of poly (chlorohexyl L-glutamate) are successfully substituted into quaternary ammonium salt form to obtain a cationic polyamino acid having the structure of formula (I).

[0254] The in vitro antibacterial activity of cationic polyamino acids was tested by plate assay:

[0255] The cationic antibacterial polyamino acid having the structure of formula (I) prepared in Examples 7 to 60 of the present invention was co-cultured with Staphylococcus aureus (S. aureus, ATCC 25923), Escherichia coli (E. coli, ATCC 25922) or methicillin-resistant Staphylococcus aureus (MRSA, ATCC 43300), and the minimum inhibitory concentration (MIC) thereof was detected:

[0256] First, Staphylococcus aureus, Escherichia coli, and methicillin-resistant Staphylococcus aureus (MRSA) were inoculated in fresh MH medium and cultured at 37°C for 12 h. Bacteria in the logarithmic phase were diluted with fresh medium and the bacteria (100.0 μL, 1×10 6 CFU / mL) were added to a 96-well plate. The cationic polyamino acid material was diluted using a gradient dilution method. Then, PBS (pH = 7.4) as a control group and the diluted cationic polyamino acid material were added to the 96-well plate, shaken for 60 s using a microplate reader to mix them evenly, and the optical density at 600 nm was measured. The culture plate was incubated at 37°C for 24 h, and then the optical density of the microbial solution was measured at 600 nm. MIC is the lowest concentration at which no bacterial growth can be detected.

[0257] The minimum inhibitory concentrations of the cationic polyamino acids having the structure of formula (I) prepared in Examples 7 to 60 against different bacteria are shown in Table 1.

[0258] Table 1 Minimum inhibitory concentration (MIC, µg / mL) of cationic polyamino acids prepared in Examples 7 to 60 against different bacteria

[0259]

[0260] As can be seen from Table 1, the cationic polyamino acid materials prepared in Examples 7 to 60 have antibacterial activity against Staphylococcus aureus (ATCC 25923) and Escherichia coli (ATCC 25922), and their MICs are between 3.9 and 1000 µg / mL. The bar chart drawn based on the experimental results in Table 1 is as follows: Figure 5 For some of the materials with excellent antibacterial effects, the minimum inhibitory concentration for MRSA was further characterized, and the results are shown in Table 2:

[0261] Table 2 Minimum inhibitory concentration (MIC, µg / mL) of cationic polyamino acids prepared in some examples against MRSA

[0262]

[0263] It can be seen from Table 2 that the cationic polyamino acid materials prepared in some examples, especially in Example 15, have good antibacterial activity against methicillin-resistant Staphylococcus aureus (ATCC 43300).

[0264] The bacterial cell membrane-destroying ability of cationic polyamino acids was verified by using scanning electron microscopy to photograph the morphology of bacterial cell membranes after treatment with the materials:

[0265] First, Staphylococcus aureus and Escherichia coli were inoculated into fresh MH medium or LB medium and cultured at 37°C for 12 h. The culture was then washed three times with PBS (pH = 7.4) and resuspended. The final concentration of the bacterial solution was 2 × 10 6 CFU / mL. 500.0 μL of bacterial suspension and 500.0 μL of cationic polyamino acid solution with a concentration of 20 μg / mL were mixed evenly, incubated at 37°C for 120 min, and the treated bacterial samples were collected by centrifugation and then washed twice with PBS. Next, they were fixed with 4% paraformaldehyde solution at 25°C for 12 h. Subsequently, the samples were washed once with PBS and dehydrated with gradient ethanol solutions (25%, 50%, 75% and 100%). Finally, the bacterial samples were dropped on a silicon wafer and the treated bacterial samples were observed by scanning electron microscopy (SEM).

[0266] See also Figure 2 , Figure 2This is the bacterial morphology after treatment with the cationic polyamino acid in Example 15 of the present invention.

[0267] from Figure 2 It can be seen that cationic polyamino acids have good ability to destroy bacterial cell membranes.

[0268] The bactericidal kinetics of cationic polyamino acids were verified by using the bacterial plate count method:

[0269] Staphylococcus aureus and Escherichia coli were inoculated in fresh MH medium or LB medium and cultured at 37°C for 12 h, washed three times with PBS (pH = 7.4) and resuspended to obtain a concentration of 1×10 6 CFU / mL of bacterial solution. Cationic polyamino acids were diluted to 1× and 2× MIC concentrations, respectively, and vancomycin and norfloxacin were used as control groups. Cationic polyamino acids, vancomycin or norfloxacin were added to the centrifuge tube with bacterial solution and treated for 2, 5, 10, 20, 30 and 60 min, respectively. At each time point, 100.0 μL of the mixture was dropped onto the agar plate and spread evenly, incubated at 37°C for 24 h, and the bactericidal rate of cationic polyamino acids was calculated by colony counting.

[0270] See also Figure 3 , Figure 3 The colony counts at different time points after treatment with the cationic polyamino acid in Example 15 of the present invention are shown in Table 3 for the raw data corresponding to each point in the figure.

[0271] Table 3 Statistical table of bactericidal kinetics of cyclic cationic polyamino acids prepared in Example 15 against Staphylococcus aureus and Escherichia coli

[0272]

[0273] from Figure 3 It can be seen that cationic polyamino acids have rapid bactericidal kinetics.

[0274] The biological safety of cationic polyamino acids was verified by in vitro cytotoxicity experiments:

[0275] The MTT method was used to detect the in vitro cytotoxicity of the cationic polyamino acid in Example 15 of the present invention. L929 cells were cultured at 3×10 4The cells were uniformly dispersed in RPMI-1640 medium at a density of 100 μL / mL and inoculated in each well of a 96-well plate at 180 μL per well and cultured at 37 °C for 24 hours. Then, the gradient diluted cationic polyamino acid or PBS solution was added to the above 96-well plate at 20 μL per well. After 24 hours of culture, 20 μL of MTT solution at a concentration of 0.2 mg / mL was added to each well and cultured again for 4 hours. The supernatant was then discarded and 150 μL of dimethyl sulfoxide was added to each well. Finally, the absorbance of the solution at 570 nm was measured using an enzyme reader, and the cell viability (%) was calculated as:

[0276] Cell viability %=OD 样本 / OD 对照 ×100%

[0277] OD 样本 and OD 对照 These are the absorbance of the sample wells with cationic polyamino acid added and the control wells with PBS solution added.

[0278] See Table 4 and Figure 4 , Table 4 and Figure 4 The survival rate of L929 cells treated with different concentrations of the cyclic cationic polyamino acid in Example 15 of the present invention is shown below. The structural formula of the linear cationic polyamino acid material used as a comparison is as follows, and its degree of polymerization and side groups are the same as those of the cyclic cationic polyamino acid in Example 15 of the present invention.

[0279]

[0280] From Table 4 and Figure 4 It can be seen that cyclic cationic polyamino acids have good biosafety, and their biosafety is better than that of linear materials with the same degree of polymerization and side groups.

[0281] Table 4 Statistical table of in vitro cytotoxicity test results of cationic polyamino acids prepared in Example 15

[0282]

[0283] The advantages of cyclic cationic polyamino acids over linear structures can be demonstrated by characterizing the selectivity index (SI) of the material:

[0284] According to the experimental structure in Table 1, the cyclic cationic polyamino acid prepared in Example 15 is the preferred material with the best antibacterial effect. By characterizing and calculating the selectivity index (SI) of the material, the gap between cyclic and linear materials can be further compared. The formula for calculating the selectivity index (SI) of the material is:

[0285] SI=IC 50 / MIC

[0286] Among them, IC 50 Table 4 and Figure 4 The highest material concentration (μg / mL) corresponding to a L929 cell survival rate greater than 50% in the cytotoxicity experiment, and MIC is the minimum inhibitory concentration (μg / mL) of the material measured by the well plate method. The selectivity index of the cyclic cationic polyamino acid prepared in Example 15 and the linear cationic polyamino acid used as a comparison is shown in Table 5.

[0287] Table 5 Selectivity index statistics of cyclic cationic polyamino acids and corresponding linear cationic polyamino acids prepared in Example 15

[0288]

[0289] The structural formula of the linear cationic polyamino acid material used as a comparison is as follows. Its degree of polymerization and side groups are the same as those of the cyclic cationic polyamino acid in Example 15 of the present invention.

[0290]

[0291] As can be seen from Table 5, the antibacterial effect of the cyclic cationic polyamino acid is comparable to that of the corresponding linear material, but it has lower cytotoxicity, so the selectivity index is 16 times that of the corresponding linear cationic polyamino acid material. Compared with the corresponding linear structure, the cyclic cationic polyamino acid antibacterial material has significantly improved the selectivity index and has a safer and more reliable application prospect.

[0292] The above is a detailed introduction to a cyclic cationic antibacterial polyamino acid, a preparation method and an application thereof provided by the present invention. The principle and implementation method of the present invention are described in detail using specific examples herein. The description of the above embodiments is only used to help understand the method and its core idea of ​​the present invention, including the best mode, and also enables any technician in the field to practice the present invention, including manufacturing and using any device or system, and implementing any combined method. It should be pointed out that for ordinary technicians in the technical field, without departing from the principle of the present invention, the present invention can also be improved and modified in several ways, and these improvements and modifications also fall within the scope of protection of the claims of the present invention. The scope of patent protection of the present invention is defined by the claims and may include other embodiments that can be thought of by those skilled in the art. If these other embodiments have structural elements that are not different from the textual expression of the claims, or if they include equivalent structural elements that are not substantially different from the textual expression of the claims, then these other embodiments should also be included in the scope of the claims.

Claims

1. A cyclic cationic polyamino acid having the structure shown in Formula I: in, n is any integer from 5 to 10; m is any integer from 4 to 8; The R1 is selected from the structure shown in Formula II, Formula III, Formula IV, Formula V or Formula VI: In formula II, x is any integer from 5 to 9.

2. The cyclic cationic polyamino acid according to claim 1, characterized in that The m is any integer from 4 to 6.

3. The cyclic cationic polyamino acid according to claim 2, characterized in that The m is 4.

4. The method for preparing the cyclic cationic polyamino acid according to any one of claims 1 to 3, comprising the following steps: A cyclic poly(chloroalkyl L-glutamic acid ester) having a structure of Formula VII is subjected to a substitution reaction with a tertiary amine NR2R3R4 to obtain a cyclic polyamino acid antibacterial material having a structure of Formula I; Wherein, n is any integer from 5 to 10; m is any integer from 4 to 8; The R1 is selected from the structure shown in Formula II, Formula III, Formula IV, Formula V or Formula VI: In formula II, x is any integer from 5 to 9; The tertiary amine NR2R3R4 has any of the following structures: x is any integer from 5 to 9.

5. The preparation method according to claim 4, characterized in that: The molar ratio of the total number of chlorine atoms contained in the cyclic poly (chloroalkyl L-glutamate) side group to the tertiary amine is 1:1 to 5; The solvent for the substitution reaction includes one or more of tetrahydrofuran, acetonitrile, dimethyl sulfoxide, N,N-dimethylformamide and N-methylpyrrolidone; The temperature of the substitution reaction is 40 to 100° C., and the time of the substitution reaction is 12 to 72 hours.

6. The preparation method according to claim 4, characterized in that: The cyclic poly(chloroalkyl L-glutamate) having the structure of formula VII is prepared according to the following method: The L-glutamic acid chloroalkyl ester-N-carboxyl cyclic anhydride represented by formula VIII undergoes a ring-opening polymerization reaction under the action of the initiator represented by formula IX to obtain a cyclic poly(L-glutamic acid chloroalkyl ester) represented by formula VII; Here, m is any integer from 4 to 8.

7. The preparation method according to claim 6, characterized in that: The solvent for the ring-opening polymerization reaction includes one or more of anhydrous tetrahydrofuran, anhydrous N,N-dimethylformamide and N-methylpyrrolidone.

8. The preparation method according to claim 6, characterized in that: The molar ratio of the L-glutamic acid chloroalkyl ester-N-carboxyl ring anhydride represented by the formula VIII to the initiator represented by the formula IX is 5 to 200:

1.

9. The preparation method according to claim 6, characterized in that: The temperature of the ring-opening polymerization reaction is 10 to 60° C., and the time of the ring-opening polymerization reaction is 1 to 7 days.

10. Use of the cyclic cationic polyamino acid according to any one of claims 1 to 3 or the cyclic cationic polyamino acid prepared by the preparation method according to any one of claims 4 to 9 in the preparation of antibacterial materials.

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