CN113121439B

CN113121439B - Compound, pharmaceutical composition, medicine and application of compound, pharmaceutical composition and medicine in preparation of antibacterial product

Info

Publication number: CN113121439B
Application number: CN202110426248.4A
Authority: CN
Inventors: 马淑涛; 宋迪; 张楠
Original assignee: Shandong University
Current assignee: Shandong University
Priority date: 2021-04-20
Filing date: 2021-04-20
Publication date: 2022-05-03
Anticipated expiration: 2041-04-20
Also published as: CN113121439A

Abstract

The invention particularly relates to a compound, a pharmaceutical composition, a medicament and application thereof in preparing antibacterial products. The search for a novel antibacterial target and the development of a novel chemical entity have important significance for solving the problem of increasingly severe bacterial drug resistance at present, and the compound entity designed to act on the FtsZ target is expected to be developed into an antibacterial drug which has no influence on a host. The invention provides a 9-aralkyl-10-methylacridine quaternary ammonium salt derivative and a preparation method thereof, wherein the compound has obvious bactericidal and/or bacteriostatic activity on gram-positive bacteria, has good effect of inhibiting bacterial division protein FtsZ, and can be used for preparing antibacterial products.

Description

Compound, pharmaceutical composition, medicine and application of compound, pharmaceutical composition and medicine in preparation of antibacterial product

Technical Field

The invention belongs to the technical field of antibacterial active compounds, and particularly relates to a 9-aralkyl-10-methylacridine quaternary ammonium salt derivative, a pharmaceutical composition containing the 9-aralkyl-10-methylacridine quaternary ammonium salt derivative, a medicament and application of the medicament in preparation of an antibacterial product.

Background

The information in this background section is not necessarily to be construed as an admission or any form of suggestion that this information forms part of the prior art.

The discovery of antibacterial drugs is a milestone in the discovery history of drugs, and clinically used antibiotics have the characteristics of high efficiency and broad spectrum and can effectively treat various diseases caused by infection of various common gram-positive bacteria and gram-negative bacteria. However, drug-resistant bacterial infections caused by the general use and abuse of antibiotics also seriously threaten global public health, in particular methicillin-resistant staphylococcus aureus, multidrug-resistant and extensively drug-resistant escherichia coli strains, klebsiella, pseudomonas aeruginosa, and the like. This greatly shortens the time for the bacteria to develop drug resistance, and the traditional approach of discovering new antibiotics can not keep up with the speed of the generation of the drug resistance of the bacteria, the resistance of the bacteria to the existing drugs and the lack of new drugs even lead to the generation of super bacteria. In addition to structural modifications to existing traditional antibiotics, the search for new antibacterial targets to develop new chemical entities to address the growing problem of bacterial resistance has also raised increasing researchers' interest.

Filament temperature sensitive protein Z (FtsZ), an important cell division protein with gtpase activity, is a FtsZ monomer that forms FtsZ protofilaments head-to-tail when GTP binds to the FtsZ monomer during cell division, many of which form protofilaments by lateral interactions and finally form a highly dynamic Z ring in the center of the cell. The Z-loop structure serves as a scaffold necessary for cell survival for assembly of the multi-protein complex, a series of accessory proteins are recruited and coordinated to form a mitogen after the formation of the Z-loop, and after recruitment is completed, the Z-loop contracts, the septum closes, and cell division is completed. Intervention in the normal biological functions of FtsZ will result in abnormal division of bacterial cells, with continued growth making them increasingly larger and more sensitive to changes in their environmental physical properties, with the cells eventually lysing and dying. Due to the wide distribution and high conservation of FtsZ and the characteristic that the FtsZ is not fully developed as an antibacterial drug target, and the sequence difference of the FtsZ and human cell tubulin is obvious, a novel antibacterial drug which acts on the FtsZ target and does not interfere with a host cell can be designed.

A plurality of FtsZ inhibitors reported at present show excellent antibacterial activity, and alkaloid compound sanguinarine has moderate inhibition effect on gram-negative bacteria and gram-positive bacteria, has broad spectrum of antibacterial activity, but also has slight inhibition effect on tubulin in eukaryotic cells. Since tubulin plays an essential role in maintaining cell shape, movement, transport of intracellular substances, etc., the above compounds may exert a bacteriostatic action and may have serious adverse effects on the body. Therefore, the method has important significance in further screening and developing compounds with high antibacterial activity and small side effect.

Disclosure of Invention

Berberine is an alkaloid with a structure similar to that of sanguinarine, and can inhibit the activity of GTPase and reduce FtsZ polymerization, but has weak antibacterial activity. The invention intercepts effective segments in berberine through structure simplification, designs FtsZ antibacterial inhibitor, and expects to obtain active compound with small molecular weight, high activity and good antibacterial specificity. Based on the technical purpose, the invention provides the following technical scheme:

in a first aspect of the present invention, there is provided a compound selected from a compound represented by formula (Ia) or a pharmaceutically acceptable salt or ester or solvate, tautomer, meso-isomer, racemate, stereoisomer, metabolite or prodrug thereof; the formula (Ia) is as follows:

wherein R is a substituent on a benzene ring, the number of the substituent can be one or more, and each substituent is independently selected from hydrogen and C₁-C₈Linear or branched alkyl, alkoxy, halogen, nitro, fluoroalkyl, fluoroalkoxy, formyl and phenyl, including substituted and unsubstituted phenyl; x is halogen; l is selected from alkenyl, alkynyl, or the site has no group.

Preferably, in the compound shown in formula Ia, when the linking bond L has no group, the compound shows that C at the para-position of N in the acridine structure is connected with a benzene ring through a C-C bond, namely, the compound has the structure shown in the following formula I:

wherein R is¹Selected from the group consisting of hydrogen, C1-C8 straight or branched chain alkyl, alkoxy, halogen, nitro, trifluoromethyl, trifluoromethoxy, formyl and phenyl. Further, said R¹The substitution site is C-2, C-3 or C-4. Further, X is I. Further, said R¹Selected from hydrogen, 2-methyl, 3-methoxy, 3-fluoro, 3-nitro, 4-methyl, 4-ethyl, 4-propyl, 4-butyl, 4-methoxy, 4-phenyl, 4-trifluoromethyl, 4-trifluoromethoxy or 4-formyl.

In a specific embodiment, the specific structure of the compound of formula I is as follows:

in addition, the invention also provides a synthetic route of the compound shown in the formula I, which is specifically shown as the following formula:

preferably, in the above synthetic route, the operation manner of step a is as follows: adding the compound 1 into an alkaline alcohol solution, and reacting under the catalysis of copper ions to obtain the intermediate 2. Further, 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.

Preferably, the step b is operated as follows: and dissolving the intermediate 2 in concentrated sulfuric acid, and heating to react under the condition of isolating oxygen to obtain an intermediate 3. Further, the heating temperature is 80-100 ℃, and the reaction time is 4-8 hours.

Preferably, the step c is operated as follows: and heating the intermediate 3 and phosphorus tribromide to react to generate an intermediate 4, wherein the heating temperature is 110-125 ℃, and the reaction time is 18-24 hours.

Preferably, the operation mode of the step d is as follows: and dissolving the intermediate 4 in dioxane-water or a toluene-water mixed solvent, and carrying out heating reaction in a zero-valent palladium catalyst and an alkaline environment to obtain an intermediate 5a-5 o. Further, the heating temperature is 85-120 ℃, and the reaction time is 4-8 hours.

Preferably, the step e is operated as follows: and dissolving the intermediate 5a-5o in a polar aprotic solvent, adding an excessive iodine-containing reagent, and reacting for a period of time to obtain the compound shown in the formula I. Furthermore, the reaction temperature is preferably 42-80 ℃, and the reaction time is 15-24 hours. Specifically, the iodine-containing reagent is methyl iodide.

Preferably, in the compound of formula Ia, when the linking bond L is a "C ═ C" bond, the structure of the compound is as shown in formula II below:

wherein R is²Selected from hydrogen, C₁-C₈Straight or branched chain alkyl, alkoxy, halogen, and phenyl. Further, said R²The substitution site is one or two of C-2, C-3 or C-4. Further, X is I. Further, said R²Is hydrogen, 2-methoxy, 4-methyl, 4-ethyl, 4-butyl, 4-tert-butyl, 4-ethoxy, 3, 4-dimethoxy, 4-phenyl, 4-fluoro, 4-chloro, 4-bromo or 2, 4-dichloro.

In a specific embodiment, the specific structure of the compound of formula II is as follows:

the invention also provides a synthetic mode of the compound shown in the formula II, and the synthetic mode has the following route:

preferably, in the synthetic route of the compound represented by the formula II, the operation mode of the step a is as follows: dissolving the compound 7 in glacial acetic acid, and heating to react under the catalysis of zinc chloride to generate an intermediate 8. Further, the heating temperature is 180-220 ℃, and the reaction time is 4-8 hours.

Preferably, in the synthetic route of the compound represented by formula II, the operation of step b is as follows: the intermediate 8 is dissolved in carbon tetrachloride or chloroform, and N-bromosuccinimide is added to react to generate an intermediate 9 under the condition initiated by azodiisobutyronitrile. Further, the reaction temperature is 60-80 ℃, and the reaction time is 4-8 hours.

Preferably, in the synthetic route of the compound of formula II, step c is performed as follows: dissolving the intermediate 9 in triethyl phosphite, and heating to react to generate an intermediate 10. Further, the heating reaction time is 120-150 ℃, and the reaction time is 2-6 hours.

Preferably, in the synthetic route of the compound shown in the formula II, the operation mode of step d is as follows: dissolving the intermediate 9 in tetrahydrofuran, and adding aldehydes to react in the presence of inorganic base to generate the intermediate 11a-11 m. Further, the reaction heating temperature is 25-40 ℃, and the reaction time is 8-12 hours.

Preferably, in the synthetic route of the compound shown in the formula II, the operation mode of the step e is as follows: dissolving 11a-11m in a polar aprotic solvent, adding excess methyl iodide, and reacting at 42-80 ℃ for 15-24 hours to generate the compound of the general formula II.

Preferably, in the compound of formula Ia, when the linking bond L is an alkynyl group, the structure of the compound is shown in formula I below:

wherein R is³Selected from hydrogen, C₁-C₈Straight or branched alkyl, alkoxy or phenyl. Further, said R³The substitution site is one of C-2, C-3 and C-4. Further, X is I. Further, said R³Is hydrogen, 2-methyl, 2-methoxy, 3-methyl, 4-ethyl, 4-butyl, 4-methoxy, 4-ethoxy, 4-propoxy or 4-phenyl. In a specific embodiment, the compound of formula III has the following specific structure:

in addition, the invention also provides a synthetic route of the compound shown in the formula III, which is shown as the following formula:

preferably, in the synthetic route of the compound shown in the formula III, the operation mode of step a is as follows: the intermediate 4 is dissolved in organic base and heated to react in the presence of palladium catalyst and copper catalyst to produce intermediates 13a-13 j. Further, the reaction temperature is 80-90 ℃, and the reaction time is 8-12 hours.

Preferably, in the synthetic route of the compound shown in the formula III, the operation mode of step b is as follows: and dissolving the intermediate 13a-13j in a polar aprotic solvent, adding excessive methyl iodide, and reacting at 42-80 ℃ for 15-24 hours to generate the compound of the general formula III.

In the scheme of the preparation method, the intermediate and the reaction product can be subjected to conventional separation means such as column chromatography, recrystallization and the like to obtain pure products of the reactions in each step.

In addition, in the embodiment of the first aspect, the pharmaceutically acceptable salt of the compound means a salt of the compound with an inorganic salt such as hydrochloric acid, sulfuric acid, nitric acid, or hydrobromic acid, and a salt with an organic acid such as methanesulfonic acid, toluenesulfonic acid, or trifluoroacetic acid, as generally understood in the art.

In a second aspect of the present invention, there is provided a pharmaceutical composition comprising a compound of the first aspect and a pharmaceutically acceptable carrier.

The "pharmaceutical composition" or "composition" according to the invention can be used for the treatment or prevention of the diseases according to the invention in a subject, in particular a mammal. The pharmaceutical composition, in which the compound of the first aspect is the active ingredient, should be in a synergistically effective dose, within the skill of the art to be determined by routine technical means.

In addition, the active ingredients of the pharmaceutical composition may include other ingredients having antibacterial or auxiliary antibacterial effects in addition to the compound of the first aspect.

As used herein, the term "pharmaceutically acceptable" or "pharmaceutically acceptable" used interchangeably therewith, such as in the description of "pharmaceutically acceptable salts", means that the salts are not only physiologically acceptable to the subject, but also synthetic substances of value in pharmaceutical use, such as salts formed as intermediates in the performance of chiral separations, which salts, although not directly administered to the subject, may play a role in obtaining the final product of the invention.

Pharmaceutical compositions of the compounds of the invention may be administered by any of the following means: oral, aerosol inhalation, rectal, nasal, vaginal, topical, parenteral such as subcutaneous, intravenous, intramuscular, intraperitoneal, intrathecal, intraventricular, intrasternal or intracranial injection or infusion, or by means of an explanted reservoir, with oral, intramuscular, intraperitoneal or intravenous administration being preferred. In particular, the dosage form of the pharmaceutical composition can be a liquid dosage form and a solid dosage form. The liquid dosage forms can be true solutions, colloids, microparticles, emulsions, and suspensions. Other dosage forms such as tablet, capsule, dripping pill, aerosol, pill, powder, solution, suspension, emulsion, granule, suppository, lyophilized powder for injection, clathrate, landfill, patch, liniment, etc.

The pharmaceutical compositions of the present invention may also contain conventional carriers, including but not limited to: ion exchangers, aluminum oxide, aluminum stearate, lecithin, serum proteins such as human serum albumin, buffer substances such as phosphates, glycerol, sorbates, potassium sorbate, partial glyceride mixtures of saturated vegetable fatty acids, water, salts or electrolytes, such as protamine sulfate, disodium hydrogen phosphate, potassium hydrogen phosphate, sodium chloride, zinc salts, colloidal silica, magnesium trisilicate, polyvinyl pyrrolidone, cellulosic substances, polyethylene glycol, sodium carboxymethylcellulose, polyacrylates, beeswax, lanolin and the like. The carrier may be present in the pharmaceutical composition in an amount of 1% to 98% by weight, typically about 80% by weight. For convenience, the local anesthetic, preservative, buffer, etc. may be dissolved directly in the vehicle.

In a third aspect of the invention, there is provided a medicament comprising a compound according to the first aspect and/or a pharmaceutical composition according to the second aspect.

In a fourth aspect of the present invention there is provided the use of a compound according to the first aspect, a pharmaceutical composition according to the second aspect and/or a medicament according to the third aspect in the manufacture of an antibacterial product.

Preferably, the antimicrobial product is one or more of the group consisting of, but not limited to, pharmaceuticals, toiletries, medical devices, kitchen ware, food preservatives, and eating utensils. Examples of the washing and caring product include vegetable detergent, shampoo, soap, bath lotion, laundry detergent, hand sanitizer, toilet cleaner or facial cleanser.

The antibacterial product is used for preventing, relieving and treating diseases caused by bacteria, preferably gram-positive bacteria; more specifically, the compound, the pharmaceutical composition and the medicament provided by the invention have better inhibition effects on bacillus subtilis, bacillus pumilus, staphylococcus aureus and drug-resistant staphylococcus aureus, and belong to broad-spectrum antibacterial active ingredients. The staphylococcus aureus is a common food-borne pathogenic bacterium, widely exists in natural environment, and can generate enterotoxin under proper conditions to cause food poisoning. The compound disclosed by the invention is proved to have an inhibiting effect on staphylococcus aureus and drug-resistant staphylococcus aureus in vitro, and can be applied to the development of antibacterial products for inhibiting staphylococcus aureus or drug-resistant staphylococcus aureus, such as antibacterial drugs, fruit and vegetable cleaning agents, hand sanitizer, tableware and kitchenware cleaning agents and the like. In the specific products, the compounds I1, I2, I3, I4, I5, I6, I7, I8, I9, I10, I11, I12, I13 and I14 have better inhibitory effect on staphylococcus aureus, and are more suitable for inhibiting the development of staphylococcus aureus products; the compounds II1, II2, II3, II4, II5, II6, II7, II8, II9, II10, II11, II12, II13, III1, III2, III3, III4, III5, III6, III7, III8, III9 and III10 are proved to have good inhibitory action on staphylococcus aureus and drug-resistant staphylococcus aureus, in particular to the compounds II4, II5, II6, II7, II11, II12, II13, III1, III4 and III5, the compounds have obvious in-vitro inhibitory effect, and the minimum inhibitory concentration can be as low as 0.25-2 mu g/mL and exceeds the effect of the existing antibacterial drugs. Specifically, the drug-resistant staphylococcus aureus comprises methicillin-resistant staphylococcus aureus and penicillin-resistant staphylococcus aureus.

In a fifth aspect of the present invention, there is provided a method of inhibiting gram-positive bacteria by administering to a subject in need thereof a compound according to the first aspect, a pharmaceutical composition according to the second aspect and/or a medicament according to the third aspect.

In a sixth aspect of the present invention, there is provided a method for the prophylaxis and/or treatment of a disease which is preventable and/or treatable by inhibition of FtsZ protein in a pathogenic bacterium, comprising administering a compound of the first aspect, a pharmaceutical composition of the second aspect and/or a medicament of the third aspect to a subject in need thereof.

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.

FIG. 1 is a scheme for the synthesis of compounds of formula I according to the present invention;

FIG. 2 is a scheme of synthesis of compounds of formula II in the present invention;

FIG. 3 is a scheme showing the synthesis of compounds of formula III according to the present invention;

FIG. 4 shows the results of the time sterilization curve examination of Compound II6 (formula II) in example 10 of the present invention;

FIG. 5 shows the results of examining FtsZ protein polymerization activity by Compound II6 (formula II) in example 11 of the present invention.

Detailed Description

It is to be understood that the following detailed description is exemplary and is intended to provide further explanation of the invention as claimed. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

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.

As described in the background, prior studies have shown that FtsZ inhibitors have excellent antibacterial activity, and that prior alkaloid compounds exhibit bacterial inhibitory effects, but are associated with certain side effects. The invention provides a series of 9-aralkyl-10-methylacridine quaternary ammonium salt derivatives and application thereof in preparing antibacterial products, wherein antibacterial effective fragments are screened from natural compounds based on active ingredients of the existing alkaloids.

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.

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 9-bromoacridine (4)

Intermediate 9(10H) -acridone prepared as described above in example 2 (4.0g, 20.5mmol) was weighed into a 250mL round bottom flask. Phosphorus tribromide (19.5mL, 205mmol) was injected dropwise at 0 deg.C in an ice bath under nitrogen blanket. After the addition, the reaction mixture was transferred to 110 ℃ and stirred at this temperature for 24 hours. After completion of the reaction was monitored by TLC, the reaction solution was cooled to room temperature and then slowly added to water to quench the reaction. The filtrate was then adjusted to pH 14 with sodium hydroxide solution, transferred to a separatory funnel, extracted three times with dichloromethane, the combined organic phases washed twice with brine, dried over anhydrous sodium sulfate, filtered with suction, and concentrated under reduced pressure to give 3.81g of a yellow solid product, intermediate 4, in 72% yield.

Example 4: preparation of 9-phenylacridine (5a)

Intermediate 9-bromoacridine (150mg, 0.58mmol) prepared in example 3 above, phenylboronic acid (0.11g, 0.87mmol), potassium carbonate (0.24g, 17.4mmol) were weighed out into a solution in dioxane and water (5: 1). A catalytic amount of tetrakistriphenylphosphine palladium (0.005mmol) was added under nitrogen and the reaction was heated to 100 ℃. After the reaction was monitored by TLC, extraction was carried out three times with dichloromethane, the combined organic phases were washed twice with brine, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to give crude product. Further separation by silica gel column chromatography (petroleum ether/ethyl acetate 8:1) gave 0.13g of a white solid, intermediate 5a, in 89% yield.

Example 5: preparation of 10-methyl-9-phenylacridine iodide salt (I1)

The intermediate 9-phenylacridine (100mg, 0.39mmol) prepared in example 4 above was dissolved in a sealed tube, and excess iodomethane (0.25mL, 3.9mmol) was added. The mixture was heated at 85 ℃ for 24h, and after completion of the reaction was monitored by TLC, isopropyl ether (50mL) was added to isolate a dark red solid. The crude product was purified by silica gel column chromatography (dichloromethane/methanol ═ 10:1) to give 80mg of the corresponding target product of formula I1 in 76% yield.

Compounds I2-I15 were prepared according to the methods described above.

The relevant characterization information for the target products of formula I, i.e., I1-I15, is shown in Table 1.

TABLE 1

Example 6: preparation of 9-methylacridine (8)

The starting N, N-diphenylamine (3.0g, 17.7mmol) and zinc chloride (12.0g, 88.6mmol) were weighed out and glacial acetic acid (3.2g, 53.2mmol) was added to it. When the temperature was raised to 180 ℃, excess glacial acetic acid was removed from the reaction mixture by distillation, then the temperature was raised further and heating was continued at 220 ℃ for 5 hours. After the completion of the reaction was monitored by TLC, the reaction solution was cooled to room temperature, and then an aqueous ammonia solution was added to obtain a yellow precipitate by filtration. The solid was then dissolved in dichloromethane, washed with aqueous sodium bicarbonate and brine, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to give the crude product. Further separation by silica gel column chromatography (petroleum ether/ethyl acetate ═ 5:1) afforded 2.77g of a pale yellow solid, intermediate 8, in 81% yield.

Example 7: preparation of 9- (bromomethyl) acridine (9)

Intermediate 9-methylacridine (2.0g, 10.4mmol) prepared in the above example 6 was weighed, 100mL of carbon tetrachloride was added as a solvent, and the temperature was raised to 60 ℃. Azobisisobutyronitrile (0.17g, 1.0mmol) was added to the solution as an initiator, and stirred at this temperature for 30 min. N-bromosuccinimide (0.17g, 11.4mmol) was then added and the temperature was raised to reflux and heating continued for 4 h. After completion of the reaction was monitored by TLC, dichloromethane was added for dilution. Separating organic phase, drying with anhydrous sodium sulfate, filtering, and concentrating under reduced pressure to obtain crude product. Further, the residue was subjected to silica gel column chromatography (petroleum ether/ethyl acetate 5:1) to obtain 92.45 g of an intermediate, which was obtained in 87% yield.

Example 8: preparation of diethyl (acridine-9-methyl) phosphonate (10)

Intermediate 9- (bromomethyl) acridine (1.0g, 3.7mmol) prepared in the above example 7 was weighed out and dissolved in 4mL triethyl phosphite, and the reaction solution was heated to reflux state and reacted for 4 h. After completion of the reaction was monitored by TLC, the reaction solution was cooled to room temperature and concentrated under reduced pressure to remove excess triethyl phosphite to give 1.1g of oil, intermediate 10, in 92% yield.

Example 9: (E) preparation of (E) -9-styrylacridine (11a)

Diethyl intermediate (acridine-9-methyl) phosphonate (0.15g, 0.45mmol) prepared in example 8 above and benzaldehyde (0.05g, 0.45mmol) were dissolved in dry tetrahydrofuran (25mL) and sodium hydrogen (65%, 33.5mg, 0.9mmol) was added carefully under ice bath conditions of 0 ℃ and stirred for 15min, after which the reaction was allowed to warm to room temperature and stirred overnight. After the reaction was monitored by TLC, after quenching with water, the resulting mixture was extracted 3 times with ethyl acetate, the combined organic phases were washed with saturated brine, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to give a crude product. Further silica gel column chromatography (dichloromethane/methanol ═ 60:1) afforded 85m g as a solid, intermediate 11a, in 67% yield.

Example 10: (E) preparation of (E) -10-methyl-9-styrylacridine iodide (II1)

Intermediate (E) -9-styrylacridine (85mg,0.3mmol) prepared in example 9 above was dissolved in a sealed tube, and excess iodomethane (0.43g,3.0mmol) was added. The mixture was heated at 85 ℃ for 24 hours and after monitoring the reaction by TLC, isopropyl ether (50mL) was added to isolate a brown solid. The crude product was purified by silica gel column chromatography (dichloromethane/methanol ═ 10:1) to give 66mg of the corresponding target product of formula II, i.e. II1, in 74% yield.

Compounds II2-II13 were prepared according to the methods described above.

The relevant characterization information for the target products of formula II, i.e., II1-II13, is shown in Table 2.

TABLE 2

Example 11: preparation of 9- (phenylethynyl) acridine (13a)

Intermediate 9-bromoacridine (0.15g, 0.58mmol) prepared in example 3 above was added to a 100mL round bottom flask, followed by the addition of catalytic amounts of bis-triphenylphosphine palladium dichloride (8.1mg, 0.01mmol) and cuprous bromide (3.3mg, 0.02 mmol). 10mL of triethylamine was added as a solvent, and the mixture was stirred at room temperature for 10min under nitrogen protection. Phenylacetylene (65mg, 0.64mmol) was then added and the reaction was refluxed for 24h at 85 ℃. After the reaction was monitored by TLC, the solution was cooled to room temperature, filtered through celite, and the filtrate was concentrated under reduced pressure to give the crude product. Further separation by silica gel column chromatography (petroleum ether/ethyl acetate 3:1) gave 0.12g of a yellow solid, intermediate 13a, in 76% yield.

Example 12: preparation of 10-methyl-9- (phenylethynyl) acridinium iodide (III1)

Intermediate 9- (phenylethynyl) acridine (0.1g,0.36mmol) prepared in example 11 above was dissolved in a sealed tube and excess iodomethane (0.51g,3.6mmol) was added. The mixture was heated at 85 ℃ for 24 hours and after monitoring the reaction by TLC, isopropyl ether (50mL) was added to isolate a brown solid. The crude product was purified by silica gel column chromatography (dichloromethane/methanol ═ 10:1) to give the corresponding target product of formula III 71.6mg, i.e. III1, in 68% yield.

Compounds III2-III10 were prepared according to the methods described above.

The relevant characterization information for the target products of formula III, i.e., III1-III10, is shown in Table 3.

TABLE 3

Example 13: determination of antibacterial Activity of 9-aralkyl-10-methylacridine Quaternary ammonium salt derivative

In this example, compounds I1-I15, II1-II13, and III1-III10 were selected for their activity in inhibiting gram-positive bacteria. The gram-positive bacteria include bacillus subtilis ATCC9372, bacillus pumilus CMCC63202, staphylococcus aureus (s.aureus ATCC25923), methicillin-resistant staphylococcus aureus (s.aureus ATCC43300), penicillin-resistant staphylococcus aureus (s.aureus PR and s.aureus CI). Au reus CI was provided by zilu hospital and other strains were purchased from tokyo shikou biotechnology limited. In this example, the antibacterial action intensity of the compound of the present invention was characterized by the Minimum Inhibitory Concentration (MIC).

MIC of each 9-aralkyl-10-methylacridine quaternary ammonium salt derivative (namely the compounds I1-I15, II1-II13 and III1-III10 of the invention) and sanguinarine (San), berberine (Ber), linezolid (Lin) and ciprofloxacin (Cip) is determined by adopting a continuous micropore double dilution method, and a compound with strong antibacterial action is screened according to the result of the MIC. Control sanguinarine, berberine, linezolid, ciprofloxacin were purchased from annaiji chemistry.

TABLE 4 results of the investigation of the in vitro antibacterial Activity of the Compounds of the present application

^aS.aureus ATCC43300:Staphylococcus aureus ATCC43300,methicillin-resistant strain；^bS.aureus PR:Staphylococcus aureus PR,penicillin-resistant strain；^cS.aureus CI:Staphylococcus aureus,clinical isolated strain,not characterized；^dSan:Sanguinarine；^eBer:Berberine；^fCip:Ciprofloxacin；^gLin:Linezolid.

As is apparent from the above experimental results, the 9-aralkyl-10-methylacridine 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.pumimus 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, particularly, the antibacterial activity against the gram-positive bacteria of the present invention of compounds I9, I10, I12, II1, II2, II3, II4, II7, II9, II11, II12, II13, III4, III5, particularly the antibacterial activity against the gram-positive bacteria of the present invention of compounds I9, I12, II1, II2, II3, II4, II7, II9, II11, II12, II13, III4, III5, particularly, the antibacterial activity against the gram-positive bacteria of the present invention of compounds I10, I12, II, 3, including methicillin-resistant to gram-positive bacteria of the present invention of the gram-positive bacteria of the present invention of the present invention of, The bacteriostatic activity of the penicillin-resistant staphylococcus aureus S.aureus PR and S.aureus CI is obviously superior to that of sanguinarine, berberine, ciprofloxacin and linezolid.

Example 14: determination of time-kill Curve for 9-aralkyl-10-methylacridine Quaternary ammonium salt derivatives

In this example, the bactericidal kinetics of 9-aralkyl-10-methylacridine quaternary ammonium salt derivatives (compounds I1-I15, II1-II13 and III1-III10 according to the present invention) were evaluated. Among them, the bactericidal kinetics of s.aureus ATCC25923 is described in detail with the compound II6 having a better activity. The bactericidal profile shown in fig. 4 reflects the bactericidal effect of varying concentrations of II6 (i.e., compound 15f in fig. 4) over time, and it was found that II6 exhibited an inhibitory effect on bacterial growth from 3 hours later, and the amount of bacteria began to decrease significantly. The solvent control (DMSO) showed a constant increase in bacterial load from 0 to 12 hours, while II6 killed the bacterial population to below the detection limit after 6 and 24 hours at 2 and 1. mu.g/mL, respectively. The bactericidal activity of compound II6 was concentration dependent and significantly inhibited bacterial growth relative to the blank. The antibacterial drug Linezolid (Linezolid) can only keep the bacterial load not increased under the concentration of 32 mug/mL.

Example 15: and (3) measuring the activity of the 9-aralkyl-10-methylacridine quaternary ammonium salt derivative on FtsZ protein.

This example demonstrates the effect of the 9-aralkyl-10-methylacridine quaternary ammonium salt derivatives of the present invention (compounds I1-I15, II1-II13 and III1-III10 of the present invention) on FtsZ protein, and the direct effect on FtsZ protein is characterized by in vitro polymerization experiments, and a fluorescence spectrophotometer measures the light scattering intensity value of FtsZ polymerization solution, thereby reflecting the polymerization kinetics of protein. FtsZ protein is provided by Biochemical research laboratory of college of medicine of Shandong university.

The compound II6 is shown in FIG. 5. The change in light scattering intensity in fig. 5 shows that compound II6 (i.e., compound 15f in fig. 5) significantly promoted the polymerization of FtsZ in a concentration-dependent manner, as its light scattering intensity increased with increasing concentration (2.5ug/mL, 5ug/mL, 10ug/mL), indicating that compound II6 acts on bacterial FtsZ protein, as opposed to that there was little significant polymerization change in FtsZ in the DMS0 blank; linezolid, acting on bacterial ribosomes, also did not have a significant effect on FtsZ polymerization at 10 ug/mL.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. 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.

Claims

1. A compound having the structure of formula II:

wherein R is²Selected from hydrogen, C₁-C₈Straight or branched chain alkyl, 2-methoxy, 4-ethoxy, 3, 4-dimethoxy, halogen and phenyl; the R is²The substitution site is one or two of C-2, C-3 or C-4 positions; and X is I.

2. The compound of claim 1, wherein R is²Is hydrogen, 2-methoxy, 4-methyl, 4-ethyl, 4-butyl, 4-tert-butyl, 4-ethoxy, 3, 4-dimethoxy, 4-phenyl, 4-fluoro, 4-chloro, 4-bromo or 2, 4-dichloro.

3. The compound of claim 1, wherein the compound of formula II has the following specific structure:

4. the method of synthesizing the compound of claim 1, wherein the compound of formula II is synthesized by the following scheme:

5. the method of synthesizing the compound of claim 4, wherein step a is performed in the following manner in the synthesis of the compound of formula II: dissolving the compound 7 in glacial acetic acid, and heating to react under the catalysis of zinc chloride to generate an intermediate 8.

6. The method for synthesizing the compound according to claim 5, wherein the heating temperature is 180 to 220 ℃ and the reaction time is 4 to 8 hours.

7. The method of claim 4, wherein step b is performed as follows in the synthetic route of the compound of formula II: and dissolving the intermediate 8 in carbon tetrachloride or chloroform, and adding N-bromosuccinimide to react under the initiation condition of azodiisobutyronitrile to generate an intermediate 9.

8. The method for synthesizing the compound according to claim 7, wherein the reaction temperature is 60 to 80 ℃, and the reaction time is 4 to 8 hours.

9. The method of synthesizing the compound of claim 4, wherein step c is performed in the following manner in the synthesis of the compound of formula II: dissolving the intermediate 9 in triethyl phosphite, and heating to react to generate an intermediate 10.

10. The method for synthesizing the compound according to claim 9, wherein the heating reaction time is 120 to 150 ℃ and the reaction time is 2 to 6 hours.

11. The method of synthesizing the compound of claim 4, wherein step d is performed as follows: dissolving the intermediate 9 in tetrahydrofuran, and adding aldehydes to react in the presence of inorganic base to generate the intermediate 11a-11 m.

12. The method for synthesizing the compound according to claim 11, wherein the reaction heating temperature is 25 to 40 ℃ and the reaction time is 8 to 12 hours.

13. The method of claim 4, wherein step e is performed as follows in the synthetic route of the compound of formula II: dissolving 11a-11m in a polar aprotic solvent, adding excess methyl iodide, and reacting at 42-80 ℃ for 15-24 hours to generate the compound of the general formula II.

14. A compound having the structure of formula III:

wherein R is³Selected from hydrogen, C₁-C₈Straight or branched chain alkyl, 2-methoxy, 4-ethoxy, 4-propoxy or phenyl; the R is³The substitution site is one of C-2, C-3 and C-4; and X is I.

15. The compound of claim 14, wherein R is³Is hydrogen, 2-methyl, 2-methoxy, 3-methyl, 4-ethyl, 4-butyl, 4-methoxy, 4-ethoxy, 4-propoxy or 4-phenyl.

16. The compound of claim 14, wherein the compound of formula III has the following specific structure:

17. a method of synthesizing a compound of claim 14, wherein the compound of formula III is synthesized according to the following formula:

18. the method of synthesizing a compound of claim 17, wherein step a is performed as follows in the synthesis of a compound of formula III: the intermediate 4 is dissolved in organic base and heated to react in the presence of palladium catalyst and copper catalyst to produce intermediates 13a-13 j.

19. The method for synthesizing the compound according to claim 18, wherein the reaction temperature is 80-90 ℃ and the reaction time is 8-12 hours.

20. A method of synthesizing a compound according to claim 17 wherein step b is performed as follows in the synthetic route for the compound of formula III: and dissolving the intermediate 13a-13j in a polar aprotic solvent, adding excessive methyl iodide, and reacting at 42-80 ℃ for 15-24 hours to generate the compound of the general formula III.

21. A medicament comprising a compound according to any one of claims 1 to 3 or a compound according to any one of claims 14 to 16.

22. Use of a compound according to any one of claims 1 to 3 or a compound according to any one of claims 14 to 16 for the manufacture of an antibacterial product.

23. The use of claim 22, wherein the antibacterial product is used for the prevention, alleviation and treatment of bacterially-induced diseases.

24. The use of claim 23, wherein the bacteria are gram positive bacteria.

25. The use of claim 23, wherein the bacteria are bacillus subtilis, bacillus pumilus, staphylococcus aureus, and drug-resistant staphylococcus aureus.

26. The use of claim 25, wherein the drug-resistant staphylococcus aureus is methicillin-resistant staphylococcus aureus (mrsa) or penicillin-resistant staphylococcus aureus (sps).

27. The use of claim 22, wherein the antimicrobial product is one of a pharmaceutical, a toiletry, a medical device, a kitchen utensil, or a food service item.

28. The use of claim 27, wherein the cleaning product is a fruit and vegetable cleaner, shampoo, soap, shower gel, laundry detergent, hand sanitizer, toilet cleaner, or facial cleanser.