阅读说明：本技术 芳香杂环取代的吖啶季铵盐类衍生物及制备方法和应用 (Aromatic heterocyclic substituted acridine quaternary ammonium salt derivative, preparation method and application thereof ) 是由 马淑涛 宋迪 张楠 于 2021-08-04 设计创作，主要内容包括：本发明属于药物化合物技术领域,涉及芳香杂环取代的吖啶季铵盐类衍生物及制备方法和应用,具有如式(I)所示的结构：其中,R～(1)选自芳杂基、取代芳杂基；X为卤素或苯磺酸阴离子。本发明提供芳香杂环取代的吖啶季铵盐类衍生物及其制备方法和应用,本发明通过结构简化,截取血根碱和小檗碱中的有效片段,和芳香杂环类药效团进行拼合,设计合成了芳香杂环取代的吖啶季铵盐类衍生物,以期望通过抑制细菌FtsZ和细菌生物膜的双重抗菌机制来发挥其独特的抗菌作用。(The invention belongs to the technical field of pharmaceutical compounds, and relates to an aromatic heterocycle substituted acridine quaternary ammonium salt derivative, a preparation method and application thereof, wherein the derivative has a structure shown as a formula (I): wherein R is 1 Selected from heteroaryl, substituted heteroaryl; x is halogen or benzene sulfonic acid anion. The invention provides an aromatic heterocyclic substituted acridine quaternary ammonium salt derivative, a preparation method and application thereofAcridine quaternary ammonium salt derivatives, which are expected to exert unique antibacterial effects by inhibiting the dual antibacterial mechanisms of bacteria FtsZ and bacterial biofilms.)

1. The aromatic heterocyclic ring substituted acridine quaternary ammonium salt derivative is characterized by having a structure shown as a formula (I):

wherein R is¹Selected from heteroaryl, substituted heteroaryl; x is halogen or benzene sulfonic acid anion.

2. The heteroaromatic substituted acridine quaternary ammonium salt derivative of claim 1, wherein the heteroaromatic group is selected from the group consisting of a five-membered heteroaromatic group, a six-membered heteroaromatic group, a benzoheterocyclic group; further, the heteroaryl is selected from thiazolyl, furyl, pyrrolyl, imidazolyl, oxazolyl, pyridyl, pyrimidinyl, pyrazinyl, morpholinyl, benzothiazolyl, indolyl, benzimidazolyl, quinolinyl, tetrahydroquinolinyl;

or the substituted aromatic hetero group is an aromatic hetero group containing one or more substituent groups;

further, the substituent of the substituted aromatic group is selected from alkyl, heteroalkyl, halogen, substituted alkyl, phenyl and substituted phenyl;

further, the alkyl is a straight chain or branched chain alkyl or heteroalkyl with 1-8C atoms, or a cycloalkyl with 3-8C atoms;

further, the substituted alkyl is that one or more hydrogens in the alkyl are substituted by halogen;

further, the substituted phenyl is that one or more hydrogens in the phenyl group are substituted.

3. The heteroaromatic substituted acridine quaternary derivative of claim 1, wherein R¹Is selected fromR²Selected from straight chain or branched chain alkyl or heteroalkyl with 1-8 carbon atoms, naphthenic base with 3-6 carbon atoms, and,R³And R⁴Each independently selected from H, F, Br, Cl, -OCH₃、-CF₃、-OCF₃、-OH、-NH₂、-OC₂H₅、-SCH₃、-N(CH₃)₂、-N(C₂H₅)₂Alkyl or heteroalkyl having 1 to 8 carbon atoms; r³And R⁴Respectively ortho-position, meta-position or para-position of the benzene ring.

4. The heteroaromatic substituted acridine quaternary salt derivative of claim 1, comprising the following compounds:

5. the preparation method of the aromatic heterocyclic substituted acridine quaternary ammonium salt derivative is characterized by comprising the following reaction route:

wherein R is¹X is as defined in any one of claims 1 to 4.

6. The process for preparing the aromatic heterocycle-substituted acridine quaternary ammonium salt derivative as claimed in claim 5, characterized in that the derivative is obtained by carrying out Ullmann reactionThen carrying out intramolecular cyclization reaction to obtainThen nucleophilic substitution reaction is carried out to obtainFollowed by nucleophilic substitution to obtainFinally, nucleophilic substitution and rearrangement are carried out to prepare the compound shown in the formula (I).

7. A pharmaceutical composition comprising the heteroaromatic-substituted acridine quaternary ammonium salt derivative and/or a solvate thereof according to any one of claims 1 to 4.

8. A pharmaceutical preparation, comprising the aromatic heterocyclic substituted acridine quaternary ammonium salt derivative or the pharmaceutical composition according to any one of claims 1 to 4 and at least one pharmaceutically acceptable carrier or excipient.

9. Use of the heteroaromatic substituted acridine quaternary ammonium salt derivative according to any one of claims 1-4, the pharmaceutical composition according to claim 7 or the pharmaceutical preparation according to claim 8 in the preparation of a medicament for preventing and treating bacterial infection;

further, the bacteria are gram-positive and gram-negative bacteria;

further, the bacteria are selected from one or more of bacillus subtilis, bacillus pumilus, staphylococcus aureus and drug-resistant staphylococcus aureus;

further, the preparation method is used for preparing bacteriostatic agents or bactericides.

10. Use of the heteroaromatic substituted acridine quaternary ammonium salt derivative according to any one of claims 1-4, the pharmaceutical composition according to claim 7 or the pharmaceutical preparation according to claim 8 for preventing and treating bacterial infection.

Technical Field

The invention belongs to the technical field of pharmaceutical compounds, and relates to an aromatic heterocycle substituted acridine quaternary ammonium salt derivative, a preparation method and application thereof.

Background

The information in this background section is only for enhancement of understanding of the general background of the invention and is not necessarily to be construed as an admission or any form of suggestion that this information forms the prior art that is already known to a person of ordinary skill in the art.

The discovery of antibiotics is known as one of the greatest achievements in the medical history of human beings, and the wide application of the antibiotics not only obviously improves the life quality of the human beings, but also effectively prolongs the whole life of the human beings. At present, more than 200 antibiotics are applied to clinic, diseases caused by various bacterial infections are effectively treated, and the antibiotics become powerful weapons for resisting the bacterial infections in human beings. However, with the widespread use of antibiotics, the problem of abuse of antibiotics is increasingly prominent, and the generation of multidrug-resistant bacteria due to abuse seriously threatens the life health and safety of human beings. Even more alarming is the rate of production of drug-resistant bacteria far faster than the rate of development of new antibiotics. At present, in order to solve the increasingly severe problem of bacterial drug resistance, in addition to strictly regulating the use of antibacterial drugs and preventing the bacterial drug resistance from generating too fast, the development of antibacterial drugs with novel action mechanisms and novel action targets should be accelerated.

Filamentous temperature sensitive protein Z (FtsZ), a highly conserved cell division protein with GTPase activity, plays a crucial role in bacterial cell division. When GTP is bound to FtsZ monomers, the FtsZ monomers are joined end to form FtsZ strands, many of which form bundles of strands through lateral interactions and ultimately highly dynamic Z rings. The Z ring is positioned in the middle of the bacterial cell and is tightly attached to the inner membrane of the cell, other proteins participating in the division process of the bacterial cell are recruited, then the Z ring shrinks, the diaphragm is formed, and the cell division is completed. FtsZ is widely found and highly conserved in both bacteria containing cell walls (e.coli, bacillus subtilis, and mycobacterium tuberculosis) and bacteria without cell walls (mycoplasma pneumoniae). Intervention in the normal biological function of FtsZ will result in abnormal division of the bacterial cells and make them more sensitive to changes in environmental physical properties, and the cells will eventually lyse and die. Due to the wide distribution and high conservation of FtsZ, a great deal of interest has been brought to researchers in recent years, and it is hoped that novel antibacterial drugs are developed through research on FtsZ target inhibitors.

Quorum Sensing (QS) is a bacterial communication mechanism that regulates gene expression and coordinates flora behavior through secretion and recognition of signal molecules by bacteria, and endows bacteria with a series of social capabilities. For example, chemical signaling molecules can directly or indirectly affect bacterial virulence factor secretion, protease synthesis, biofilm formation, bacterial drug resistance, and the like during quorum sensing processes. Blocking the mutual connection among the bacterial thalli can effectively reduce the pathogenicity and drug resistance of the bacteria. Therefore, QS inhibitors are expected to be new therapies for anti-infective treatment. However, the current compounds all have high side effects, and the antibacterial activity is to be further improved. Therefore, how to further develop a compound with good antibacterial activity and less side effects is of great significance.

Disclosure of Invention

In order to solve the defects of the prior art, the invention provides the acridine quaternary ammonium salt derivative substituted by the aromatic heterocycle, and a preparation method and application thereof.

Specifically, the invention is realized by the following technical scheme:

in a first aspect of the present invention, the heteroaromatic substituted acridine quaternary ammonium salt derivative has a structure represented by formula (I):

wherein R is¹Selected from heteroaryl, substituted heteroaryl; x is halogen or benzene sulfonic acid anion.

In the second aspect of the present invention, the preparation method of the aromatic heterocyclic substituted acridine quaternary ammonium salt derivative comprises the following reaction scheme:

wherein R is¹And X is as defined in any one of the above.

In the third aspect of the invention, a pharmaceutical composition contains the aromatic heterocyclic substituted acridine quaternary ammonium salt derivative and/or solvate thereof.

In the fourth aspect of the invention, a pharmaceutical preparation comprises the aromatic heterocyclic substituted acridine quaternary ammonium salt derivative or a pharmaceutical composition and at least one pharmaceutically acceptable carrier or excipient.

In the fifth aspect of the invention, the application of the aromatic heterocyclic substituted acridine quaternary ammonium salt derivative, the pharmaceutical composition or the pharmaceutical preparation in preparing a medicament for preventing and treating bacterial infection is provided.

In the sixth aspect of the invention, the application of the aromatic heterocyclic substituted acridine quaternary ammonium salt derivative, the pharmaceutical composition or the pharmaceutical preparation in preventing and treating bacterial infection is provided.

One or more embodiments of the present invention have the following advantageous effects:

(1) the aromatic heterocyclic ring substituted acridine quaternary ammonium salt derivative has a remarkable inhibiting effect on various sensitive bacteria and drug-resistant bacteria, and is not easy to induce staphylococcus aureus to generate drug resistance.

(2) The aromatic heterocyclic ring substituted acridine quaternary ammonium salt derivative has obvious interference effect on bacterial FtsZ polymerization and bacterial biomembrane, and the effect is increased along with the increase of concentration.

(3) The aromatic heterocyclic ring substituted acridine quaternary ammonium salt derivative has good bactericidal effect, and the bactericidal effect has concentration dependence.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate exemplary embodiments of the invention and together with the description serve to explain the invention and not to limit the invention. Embodiments of the invention are described in detail below with reference to the attached drawing figures, wherein:

FIG. 1: a graph showing the reference results of the time sterilization curves of I-14 in the examples;

FIG. 2: is a graph of the reference results of I-14 in the examples on the effect of FtsZ protein polymerization;

FIG. 3: reference results plot for resistance induced by susceptible s.aureus ATCC25923 for I-14 in the examples.

Detailed Description

The invention will be further illustrated with reference to the following specific examples. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. The experimental procedures, in which specific conditions are not noted in the following examples, are generally carried out according to conventional conditions or according to conditions recommended by the manufacturers.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

In order to make the technical solutions of the present invention more clearly understood by those skilled in the art, the technical solutions of the present invention will be described in detail below with reference to specific embodiments. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. The experimental procedures, in which specific conditions are not noted in the following examples, are generally carried out according to conventional conditions or according to conditions recommended by the manufacturers.

Unless otherwise indicated, the starting materials and reagents for use in the invention are commercially available or may be prepared according to methods known in the art or by routine experimentation by those skilled in the art. In addition, any methods and materials similar or equivalent to those described herein can be used in the methods of the present invention. The preferred embodiments and materials described herein are intended to be exemplary only.

In one or more embodiments of the present invention, the heteroaromatic substituted acridine quaternary ammonium salt derivative has a structure represented by formula (I):

wherein R is¹Selected from heteroaryl, substituted heteroaryl; x is halogen or benzene sulfonic acid anion.

The aromatic hetero group is selected from five-membered aromatic hetero group, six-membered aromatic hetero group and benzo heterocyclic group; further, the heteroaryl group is selected from thiazolyl, furyl, pyrrolyl, imidazolyl, oxazolyl, pyridyl, pyrimidinyl, pyrazinyl, morpholinyl, benzothiazolyl, indolyl, benzimidazolyl, quinolinyl, tetrahydroquinolinyl.

Or the substituted aromatic hetero group is an aromatic hetero group containing one or more substituents.

Further, the substituent of the substituted heteroaryl is selected from alkyl, heteroalkyl, halogen, substituted alkyl, phenyl, substituted phenyl.

Further, the alkyl is a straight chain or branched chain alkyl or heteroalkyl with 1-8C atoms and a cycloalkyl with 3-8C atoms.

Further, the substituted alkyl is that one or more hydrogens in the alkyl are substituted by halogens.

Further, the substituted phenyl is that one or more hydrogens in the phenyl group are substituted.

Further, R¹Is selected from R²Selected from straight chain or branched chain alkyl or heteroalkyl with 1-8 carbon atoms, naphthenic base with 3-6 carbon atoms, and,R³And R⁴Each independently selected from H, F, Br, Cl, -OCH₃、-CF₃、-OCF₃、-OH、-NH₂、-OC₂H₅、-SCH₃、-N(CH₃)₂、-N(C₂H₅)₂Alkyl or heteroalkyl having 1 to 8 carbon atoms; r³And R⁴Respectively ortho-position, meta-position or para-position of the benzene ring.

Specifically, the aromatic heterocyclic substituted acridine quaternary ammonium salt derivative comprises the following compounds:

the preparation method of the aromatic heterocyclic substituted acridine quaternary ammonium salt derivative comprises the following reaction route:

wherein R is¹And X are as described above.

Specifically, the preparation method comprises the following steps: firstly carrying out Ullmann reaction to obtainThen carrying out intramolecular cyclization reaction to obtainThen nucleophilic substitution reaction is carried out to obtainFollowed by nucleophilic substitution to obtainFinally, nucleophilic substitution and rearrangement are carried out to prepare the compound shown in the formula (I).

With R¹Is composed ofFor example, the preparation route is as follows:

the method comprises the following operation steps: o-bromobenzoic acid and aniline undergo Ullmann condensation and intramolecular cyclization, undergo nucleophilic substitution reaction with methyl iodide, and are chlorinated to obtain an intermediate 5. The aromatic heterocyclic substituent is prepared by nucleophilic substitution, and the post intermediate 5 and the aromatic heterocyclic substituent are subjected to nucleophilic substitution and rearrangement to obtain a final product.

More specifically, the preparation method comprises the following steps:

(1) adding o-bromobenzoic acid into an alkaline alcohol solution, and reacting under the catalysis of copper ions to obtain the intermediate 2. More specifically, the alkaline alcohol solution is preferably ethanol, and is prepared by adding inorganic base; the catalysis is realized by adding a catalyst, and the catalyst can be one or the combination of copper powder, cuprous chloride, copper acetate or copper sulfate; the temperature of the catalytic reaction is 70-80 ℃, and the reaction time is 12-24 hours.

(2) And dissolving the intermediate 2 in concentrated sulfuric acid, and heating to react under the condition of isolating oxygen to obtain an intermediate 3. More specifically, the heating temperature is 80-100 ℃, and the reaction time is 4-8 hours.

(3) Dissolving the intermediate 3 in N, N-dimethylformamide, adding sodium hydride at 0 ℃ to remove hydrogen, and carrying out nucleophilic substitution reaction with methyl iodide to obtain an intermediate 4. More specifically, the heating temperature is 60 ℃, and the reaction time is 12-24 hours.

(4) And dissolving the intermediate 4 in thionyl chloride for refluxing, and carrying out chlorination reaction to obtain an intermediate 5. More specifically, the heating temperature is 80 ℃, and the reaction time is 1-2 hours.

(5) The aromatic heterocycle 6 is dissolved in alkyl halides with different substituents to carry out nucleophilic substitution reaction, and the aromatic heterocycle substituent 7 is obtained.

(6) Dissolving the intermediate 5 and the aromatic heterocyclic substituent 7 in methanol, adding a saturated potassium carbonate aqueous solution to bind acid, adding a saturated potassium iodide solution to adjust salt, and performing column chromatography purification to obtain the corresponding compound shown in the formula (I).

A pharmaceutical composition contains the aromatic heterocyclic substituted acridine quaternary ammonium salt derivative and/or a solvate thereof, wherein the solvate comprises an organic solvate and a hydrate.

A pharmaceutical preparation comprises the aromatic heterocyclic substituted acridine quaternary ammonium salt derivative or a pharmaceutical composition and at least one pharmaceutically acceptable carrier or excipient.

The pharmaceutically acceptable carriers or excipients described herein are non-toxic and safe, and their combinations with the compounds of the present invention are also non-toxic and safe. The pharmaceutically acceptable carriers and excipients of the present invention are generally well known to those skilled in the art or can be determined by those skilled in the art in view of the actual circumstances. Examples of suitable carriers and excipients include glucose, water, glycerol, ethanol, propylene glycol, corn starch, gelatin, lactose, sucrose, alginic acid, microcrystalline cellulose, kaolin, mannitol, dicalcium phosphate, sodium chloride, croscarmellose sodium, sodium starch glycolate, and the like; hydrophilic carriers, hydrophobic carriers, or combinations thereof, and the like. Hydrophobic carriers include, for example, fat emulsions, lipids, pegylated phospholipids, biocompatible polymers, lipid spheres, liposomes, vesicles, polymer matrices, particles, and the like. Furthermore, one skilled in the art will appreciate that diluents are included within the term carrier and excipient. For convenience, the local anesthetic, preservative, buffer, etc. may be dissolved directly in the vehicle.

The pharmaceutical composition and the pharmaceutical preparation of the invention can be administered in unit dosage form, and the administration dosage forms comprise injections, tablets, pills, capsules, suspending agents, emulsions, aerosols, powders, freeze-dried powder injections, inclusion compounds, landfill agents, patches, liniments and the like. These dosage forms can be prepared according to conventional methods in the art by adding suitable excipients or excipients.

The application of the aromatic heterocyclic ring substituted acridine quaternary ammonium salt derivative, the pharmaceutical composition or the pharmaceutical preparation in preparing a medicament for preventing and treating bacterial infection;

further, the bacteria are gram-positive and gram-negative bacteria;

further, the bacteria are selected from one or more of bacillus subtilis, bacillus pumilus, staphylococcus aureus and drug-resistant staphylococcus aureus;

further, the preparation method is used for preparing bacteriostatic agents or bactericides.

The application of the aromatic heterocyclic ring substituted acridine quaternary ammonium salt derivative, the pharmaceutical composition or the pharmaceutical preparation in preventing and treating bacterial infection is provided.

The present invention is described in further detail below with reference to specific examples, which are intended to be illustrative of the invention and not limiting.

Example 1

Preparation of 2- (phenylamino) benzoic acid (2)

The starting materials, 2-bromobenzoic acid (2.0g, 10mmol), aniline (1.85g, 20mmol), potassium carbonate (1.37g, 10mmol) and catalytic amount of copper powder (0.2-0.3 μm, 4.97mmol) were weighed out and dissolved in 80mL of ethanol. Heating the reaction liquid for 12h under reflux, monitoring the reaction by TLC (thin layer chromatography), pouring the cooled reaction liquid into hot water, removing insoluble substances by diatomite hot filtration, then acidifying the filtrate by diluted hydrochloric acid solution to adjust the pH value to 5-6, separating out a large amount of precipitate, and recrystallizing and purifying the obtained precipitate by ethanol to obtain 1.65g of a pure grey solid product, namely the intermediate 2, with the yield of 78%.

Example 2

Preparation of 9(10H) -acridone (3)

The intermediate 2- (phenylamino) benzoic acid prepared in example 1 above (2.0g, 9.4mmol) was charged to a 100mL round bottom flask, to which was added 10mL concentrated sulfuric acid. Stirring the mixture for 6 hours at 100 ℃ under the protection of nitrogen, monitoring the complete reaction by TLC, cooling to room temperature, pouring the cooled reaction liquid into a large amount of ice water, stirring, precipitating a solid, performing suction filtration under reduced pressure, collecting the solid, washing the solid for a plurality of times by using a saturated sodium bicarbonate solution, and performing vacuum drying to obtain a yellow solid product 1.5g, namely an intermediate 3 with the yield of 82%.

Example 3

Preparation of 10-methylacridin-9 (10H) -one (4)

The 9(10H) -acridone prepared in example 2 above (1.5g, 7.7mmol) was taken up in DMF, N₂Protection, NaH (0.55g, 23mmol) was added at 0 deg.C, stirred for 30min, and iodomethane (1.64g, 11.5mmol) was added via syringe, then transferred to room temperature and stirred for 4h, TLC detected complete reaction. Intermediate 4 was obtained as a yellow solid 1.35g with a yield of 84%.

Example 4

Preparation of 10-methyl-9-chloroacridine chloride salt (5)

10-Methylacridin-9 (10H) -one (0.2g, 0.96mmol), prepared as described in example 3 above, was taken up in thionyl chloride and N₂Protection, stirring for 2h under reflux, TLC detection to complete the reaction, and rotary evaporation to remove the solvent to obtain intermediate 5, which is 0.22g of yellow solid and has the yield of 87%.

Example 5

Preparation of 2, 3-dimethylthiazoliodonium salt (7)

Weighing raw material 2-methylthiazole (1.0g, 10.1mmol) and dissolving in iodomethane (7.17g,50.5mmol), reacting for 8h under reflux state, detecting by TLC that the reaction is complete, adding isopropyl ether to precipitate solid, and performing suction filtration to obtain white solid 2.07g, wherein the yield is 85%.

Example 6

Synthesis of Compound (I-1) represented by the formula (I)

10-methyl-9-chloroacridine chloride (0.22g, 0.83mmol) obtained in example 4 and 2, 3-dimethylthiazolium iodide (0.24g, 1mmol) obtained in example 5 were dissolved in methanol, and a saturated potassium carbonate solution was added dropwise thereto to react at room temperature for 2 hours, followed by addition of a small amount of saturated potassium iodide solution and continued reaction for 20 minutes, and TLC was performed to detect completion of the reaction, and silica gel column chromatography (eluent PE: EA: 1, DCM: MeOH: 50:1 → DCM: MeOH: 10:1) was performed to obtain I-1, 0.29g of a purple solid, and yield was 82%. The relevant structure confirmation information of the compounds is shown in table 1.

The preparation processes of the compounds I-2 to I-8, I-9 to I-16 and I-17 to I-24 are the processes for preparing I-1 as described above, and only the raw materials need to be replaced correspondingly.

TABLE 1 structural confirmation information Table for Compounds I-1 to I-24

Example 7

Determination of antibacterial activity of aromatic heterocyclic substituted acridine quaternary ammonium salt derivative

This example characterizes the antibacterial effect strength of the compounds of the invention by determining the Minimal Inhibitory Concentration (MIC) of the compounds of interest (i.e. compounds I-1 to I-24 of the invention) against various gram-positive bacteria, including bacillus subtilis tcc9372, bacillus pumilus (b.pumilus CMCC63202), staphylococcus aureus susceptible (s.aureus atcc25923), staphylococcus aureus resistant to methicillin (s.aureus ATCC43300), staphylococcus aureus resistant to penicillin (s.aureus PR) and (s.aureus CI, clinical isolation). The strain is derived from China general microbiological culture Collection center (CGMCC), China Industrial microbiological culture Collection center (CICC) and Qilu hospital.

MIC of each aromatic heterocyclic ring substituted acridine quaternary ammonium salt derivative (namely compounds I-1-I-24, Linezolid (Lin), ciprofloxacin (Cip), sanguinarine (San) and berberine (Ber)) is determined by a two-fold release method, and a compound with strong antibacterial effect is screened according to the result of the MIC. Control sanguinarine, berberine, linezolid, ciprofloxacin were purchased from annaiji chemistry.

TABLE 2 examination of the in vitro antibacterial Activity of the Compounds of the present application

^aS.aureusATCC43300:Staphylococcus aureusATCC43300,methicillin-resistant strain；

^bS.aureusPR:Staphylococcus aureusPR,penicillin-resistant strain；

^cS.aureus CI:Staphylococcus aureus,clinical isolated strain,not characterized；

^dSan:Sanguinarine；^eBer:Berberine；^fCip:Ciprofloxacin；^gLin:Linezolid.

As can be seen from the above experimental results, the heteroaromatic substituted acridine quaternary ammonium salt derivatives of the present invention have excellent antibacterial activity against gram-positive bacteria including bacillus subtilis such as b.subtilis ATCC9372, bacillus pumilus such as b.pumilus CMCC63202, staphylococcus aureus such as s.aureus ATCC25923, methicillin-resistant staphylococcus aureus such as s.aureus ATCC43300, penicillin-resistant staphylococcus aureus such as s.aureus PR and s.aureus CI. The synthesized compounds I-3 to I-24 have antibacterial activity superior to that of berberine on all gram-positive strains to be detected, and have the antibacterial activity particularly prominent with I-7, I-8, I-12, I-13, I-14, I-16, I-21, I-22, I-23 and I-24, and the activity is remarkably superior to sanguinarine, ciprofloxacin and linezolid. The minimum inhibitory concentration of I-8 and I-14 on methicillin-resistant staphylococcus aureus such as S.aureus ATCC43300 can reach 0.25 mu g/mL, and the antibacterial activity is 64 times better than that of ciprofloxacin and 8 times better than that of linezolid. The minimum inhibitory concentration of I-8, I-14, I-16 and I-24 to penicillin-resistant staphylococcus aureus such as S.aureus PR can reach 1 mu g/mL, the antibacterial activity is 4 times better than that of linezolid and 16 times of sanguinarine, and ciprofloxacin has no inhibitory effect on the strain.

Example 8

Determination of time sterilization curve of aromatic heterocycle substituted acridine quaternary ammonium salt derivative

This example evaluates the bactericidal kinetics of the aromatic heterocycle-substituted acridine quaternary ammonium salt derivatives (I-1 to I-24). Wherein, the bactericidal kinetics characteristics of the compound I-14 with better activity to sensitive staphylococcus aureus (S.aureus ATCC25923) are explained in detail. The sterilization curve shown in FIG. 1 reflects the sterilization effect of I-14 (compound I-14 is shown as 10f in FIG. 1) with different concentrations over time, and the compound I-14 has a remarkable sterilization effect on Staphylococcus aureus, and the sterilization effect has an obvious concentration dependence characteristic, and the sterilization effect is better when the concentration is higher. The negative control adopts DMSO, the bacterial quantity is continuously increased within 0 to 12 hours, and the antibacterial activity is not generated. The positive control is a linezolid solution with the concentration of 32 mu g/mL, and the bacterial load can only be kept unchanged within 24 hours. The target compound I-14 has a bacteriostatic effect similar to that of a linezolid solution with the concentration of 0.5 mu g/mL, the concentration of the compound is increased, and the number of detected viable bacteria is further reduced. I-14 killed the number of bacteria to below the detection limit after 6 hours at 4. mu.g/mL, and completely killed the bacteria after 9 hours and did not grow any more.

Example 9

Effect of aromatic heterocycle substituted acridine quaternary ammonium salt derivative on FtsZ protein polymerization

In the embodiment, the direct effect of the aromatic heterocycle substituted acridine quaternary ammonium salt derivatives (I-1-I-24) on FtsZ protein is characterized by an in vitro polymerization experiment through verification, and a fluorescence spectrophotometer is used for measuring the light scattering intensity value of FtsZ polymerization solution, so that the polymerization kinetic characteristics of the protein are reflected.

The compound I-14 is shown in FIG. 2. The change in light scattering intensity values in figure 2 shows that there is almost no significant change in FtsZ polymerization under DMSO blank; linezolid acting on bacterial ribosomes also did not exert an effect on FtsZ polymerization at l0 μ g/mL, consistent with the blank control DMSO; while I-14 (i.e., 10f in FIG. 2) significantly promoted the polymerization of FtsZ protein in a concentration-dependent manner, as evidenced by the increase in light scattering intensity with increasing compound concentration (2.5. mu.g/mL, 5. mu.g/mL, l 0. mu.g/mL). The experimental result shows that the compound I-14 acts on FtsZ protein of bacteria.

Example 10

Drug resistance induction experiment of aromatic heterocyclic substituted acridine quaternary ammonium salt derivative

In this embodiment, the drug resistance of staphylococcus aureus (s.aureus atcc25923) induced to a target compound is reflected in a manner of inducing the aromatic heterocycle substituted acridine quaternary ammonium salt derivative I-14 under a sub-concentration and determining the minimum inhibitory concentration after passage. The control compound ciprofloxacin developed 2-fold resistance in the first passage, and then continued to increase until the tenth passage increased 64-fold, after which higher bacteriostatic concentrations were maintained. While the minimal inhibitory concentration of the target compound I-14 (i.e., 10f in FIG. 3) did not fluctuate by more than a factor of 2. The experimental result shows that compared with the ciprofloxacin which is the medicament on the market, the target compound I-14 is not easy to induce to generate drug resistance.

Although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that changes may be made in the embodiments and/or equivalents thereof without departing from the spirit and scope of the invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.