Antibacterial adjuvant containing biphenyl derivative compound as active ingredient and its use

Abstract

The present invention relates to an antibacterial adjuvant containing a biphenyl derivative compound as an active ingredient and a technique for using the same in various ways. The compound of the present invention improves the sensitivity of gram-negative bacteria to polymyxin antibiotics, thereby reducing the dosage of polymyxin antibiotics used to inhibit the growth of gram-negative bacteria, and when administered in combination with polymyxin antibiotics, exhibits growth inhibition and killing effects on gram-negative bacteria, significantly reduces side effects such as nephrotoxicity, and can prevent or treat sepsis and septic shock caused by overuse of antibiotics.

Description

[Technical field]

[0001] The present invention relates to an antibacterial adjuvant containing a biphenyl derivative compound as an active ingredient and techniques for various uses thereof. [Background technology]

[0002] The emergence and increase of antibiotic-resistant bacteria, which have acquired drug resistance and can survive even when exposed to antibiotics, is causing a major problem worldwide. As of 2018, the number of deaths due to infection with antibiotic-resistant bacteria worldwide reached 700,000, and in Korea, the five major antibiotic-resistant bacteria (Methicillin-resistant Staphylococcus aureus (MRSA), Multidrug-resistant Acinetobacter baumannii (MDRA), Multidrug-resistant Pseudomonas aeruginosa (MRPA), Vancomycin-resistant Streptococcus aeruginosa (VRE), and Carbapenem-resistant Enterobacteriaceae (CRE)) caused 9,000 infections and 3,600 deaths per year, resulting in a mortality rate of about 40%. In addition, the total social cost of Korea due to medical expenses, nursing expenses, and productivity loss due to early deaths for patients infected with antibiotic-resistant bacteria is estimated to be 550 billion won per year, and the spread of antibiotic resistance can cause economic losses as well as human health. In particular, with the emergence of multi-drug resistant bacteria (super-bacteria) that simultaneously exhibit resistance to all existing antibiotics, the damage caused by antibiotic-resistant bacteria is expected to increase exponentially.

[0003] Antibiotic-resistant bacteria are known to acquire resistance to antibiotics by (1) secreting antibiotic-degrading enzymes to eliminate antibiotic activity, or by changing the structure of antibiotics with antibiotic-converting enzymes, (2) reducing the concentration of antibiotics in cells by inhibiting antibiotic inflow / activating antibiotic outflow through efflux pumps, or (3) changing the target protein to which antibiotics bind through mutation. Antibiotic-resistant bacteria are known to effectively counter antibiotics by mobilizing two or more resistance mechanisms, and the more mechanisms are mobilized, the greater the degree of resistance. Therefore, antibiotics to combat resistant strains must be able to (1) inhibit new bacterial targets that have not been known until now, or (2) avoid the development of resistance by inhibiting a diverse group of targets.

[0004] To solve the problem of antibiotic-resistant bacteria infection, it is necessary to develop new antibiotics, but it is difficult to find targets for new drug development, and new drug development requires an average cost of about 800 million dollars and a minimum of 10 years, which has caused many difficulties. An even more serious problem is that even if new antibiotics are developed by finding new targets that can avoid the resistance mechanisms known so far, resistant bacteria will appear quickly. In fact, linezolid, which has a different mechanism of action from existing antibiotics, was approved as the only new target inhibitor in the 2000s, but bacteria resistant to it have already appeared. Therefore, from the perspective of cost and time, it can be said that an effective strategy to deal with antibiotic-resistant bacteria infection is to develop a substance that can inhibit the resistance mechanism acquired by antibiotic-resistant bacteria so as to increase the effectiveness of existing antibiotics rather than developing a new antibiotic.

[0005] Therefore, there is a need to develop a technology that can kill bacteria by increasing their susceptibility to antibiotics by simultaneously treating them with antibiotics that have become unusable due to resistance. Summary of the Invention [Problem to be solved by the invention]

[0006] It is an object of the present invention to provide an antibacterial adjuvant that increases the susceptibility of bacteria to antibiotics.

[0007] Another object of the present invention is to provide an antibacterial composition containing the above-mentioned antibacterial adjuvant and a polymyxin antibiotic as active ingredients.

[0008] It is still another object of the present invention to provide a pharmaceutical composition for preventing or treating organ damage caused by sepsis or septic shock, which comprises the above-mentioned antibacterial adjuvant and a polymyxin antibiotic as active ingredients. [Means for solving the problem]

[0009] To achieve the above object, one aspect of the present invention provides an antibacterial adjuvant comprising a compound represented by the following Chemical Formula 1 or a pharma- ceutically acceptable salt thereof as an active ingredient: [ka] (wherein X is a halogen atom, and R1 and R2 are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms).

[0010] Another aspect of the present invention provides an antibacterial composition comprising the above-mentioned antibacterial adjuvant and a polymyxin antibiotic as active ingredients.

[0011] Another aspect of the present invention provides a pharmaceutical composition for preventing or treating organ damage caused by sepsis or septic shock, comprising the above-mentioned antibacterial adjuvant and a polymyxin antibiotic as active ingredients. Effect of the Invention

[0012] The antibacterial adjuvant of the present invention can reduce the dosage of polymyxin antibiotics used to inhibit the growth of gram-negative bacteria by up to 128 times by increasing the sensitivity of gram-negative bacteria to polymyxin antibiotics.

[0013] Furthermore, the antibacterial adjuvant of the present invention, when administered in combination with a polymyxin antibiotic, exhibits a synergistic effect of inhibiting the growth of and killing gram-negative bacteria.

[0014] In addition, according to the present invention, side effects such as nephrotoxicity caused by the overdose of polymyxin can be significantly reduced, and sepsis and septic shock caused by the overdose of antibiotics can be prevented or treated.

[0015] The effects of the present invention are not limited to those mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the following description. [Brief description of the drawings]

[0016] [Figure 1] This is a graph showing the bacterial growth inhibitory effects of PA108 and its derivatives (PA108-1 to 14), and polymyxin B (PMB) on the Sinetobacter baumannii strain, as measured by the relative respiration rate of the bacteria. [Diagram 2] 1 is a graph showing the bacterial growth inhibitory effect of treatment of Acinetobacter baumannii strain with polymyxin B (PMB) alone, PA108 alone, or a combination of polymyxin B (PMB) and PA108, via the relative respiration rate of the bacteria. [Diagram 3] 1 is a graph showing the cell killing effect of treatment with polymyxin B (PMB) alone, PA108 alone, or a combination of polymyxin B (PMB) and PA108 against Acinetobacter baumannii strain. [Figure 4] The results of a checkerboard analysis were used to confirm whether or not a synergistic effect was observed when polymyxin B (PMB) and PA108 were combined for treatment of Acinetobacter baumannii strains. [Diagram 5] Morphological changes in Acinetobacter baumannii strains were observed using a fluorescent microscope (top) and a scanning electron microscope (bottom) when the strain was treated with polymyxin B (PMB) alone, PA108 alone, or a combination of polymyxin B (PMB) and PA108. [Figure 6] Nephrotoxicity of polymyxin B (left) and PA108 (right) in human renal cells is shown via renal cell viability. [Figure 7] In a mouse sepsis model caused by infection with Acinetobacter baumannii, the survival rate of mice was shown when polymyxin B (PMB) alone, PA108 alone, or a combination of polymyxin B (PMB) and PA108 was administered. [Figure 8] The results are shown in a checkerboard analysis to confirm whether a synergistic effect is observed when polymyxin B (PMB) and PA108 are combined for three Klebsiella pneumoniae strains and three Pseudomonas aeruginosa strains resistant to polymyxin antibiotics. [Figure 9] The figure shows the number of genes whose expression was increased (left) and the number of genes whose expression was decreased (right) when Acinetobacter baumannii strain was treated with polymyxin B (PMB) alone, PA108 alone, or a combination of polymyxin B (PMB) and PA108, compared to the control group. [Figure 10] This shows the functional information of genes with high statistical significance among those whose expression was increased or decreased when treated with polymyxin B (PMB) and PA108 in combination compared to the control group (purple: PMB and PA108 combined treatment group, yellow: PMB treatment group, blue: PA108 treatment group). [Figure 11] The changes in bacterial cell membrane permeability (left) and cytoplasmic membrane potential (right) are shown when Acinetobacter baumannii strain is treated with polymyxin B (PMB) alone, PA108 alone, or a combination of polymyxin B (PMB) and PA108. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] The present invention will be described in detail below.

[0018] One aspect of the invention provides an antibacterial adjuvant that increases the susceptibility of bacteria to antibiotics.

[0019] The antibacterial adjuvant of the present invention contains a compound represented by the following chemical formula 1 or a pharma- ceutically acceptable salt thereof as an active ingredient. [ka]

[0020] In the above Chemical Formula 1, X may be any one halogen atom selected from the group consisting of F, Cl, Br, and I, and X may be any one selected from the group consisting of F, Cl, and Br, and X may be Cl.

[0021] In the above formula 1, R1 and R2 may each independently be a hydrogen atom or an alkyl group.

[0022] The alkyl group refers to a linear or branched saturated aliphatic hydrocarbon group, and may be an alkyl group having 1 to 12 carbon atoms, 1 to 10 carbon atoms, 1 to 8 carbon atoms, or 1 to 6 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, sec-butyl, n-pentyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, 2,2-dimethylpropyl, 1-ethylpropyl, 2-methylbutyl, 3-methylbutyl, n-hexyl, 1-ethyl-2-methylpropyl, 1,1,2-trimethylpropyl, 1,1-dimethylbutyl, 1,2-dimethylbutyl, 2,2-dimethylbutyl, 1,3-dimethylbutyl, 2-ethylbutyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 2,3-dimethylbutyl, and the like.

[0023] The alkyl may be substituted or unsubstituted. When substituted, the substituent may be substituted at any available attachment point. The substituent is preferably any one or more independently selected from the group consisting of alkyl, alkenyl, alkynyl, alkoxy, alkylthio, alkylamino, halogen, thiol, hydroxy, nitro, cyano, cycloalkyl, heterocyclyl, aryl, heteroaryl, cycloalkoxy, heterocyclic alkoxy, cycloalkylthio, heterocyclic alkylthio, oxo, carboxy, and alkoxycarbonyl, but is not limited thereto.

[0024] The term "pharmaceutically acceptable salt" refers to a salt prepared by a conventional method, and the salt may be any one selected from the group consisting of inorganic acids and organic acids, including hydrochloric acid, hydrobromic acid, sulfuric acid, phosphoric acid, methanesulforic acid, ethanesulforic acid, malic acid, acetic acid, oxalic acid, tartaric acid, citric acid, lactic acid, fumaric acid, succinic acid, maleic acid, salicylic acid, benzoic acid, phenylacetic acid and mandelic acid, but is not limited thereto.

[0025] "Pharmaceutically acceptable salts" also include those formed from cations such as sodium, potassium, aluminum, calcium, lithium, magnesium, zinc, and from bases such as ammonia, ethylenediamine, N-methyl-glutamine, lysine, arginine, ornithine, choline, N,N'-dibenzylethylenediamine, chloroprocaine, diethanolamine, procaine, N-benzylphenethylamine, diethylamine, piperazien, tri(hydroxymethyl)aminomethane, and tetramethylammonium hydroxide. These salts may be prepared by standard procedures, for example by reaction of the free acid with a suitable organic or inorganic base. "Pharmaceutically acceptable salts" also include free acids, free bases and zwitterionic forms.

[0026] The compound represented by Chemical Formula 1 may have the effect of improving the antibiotic sensitivity of bacteria resistant to antibiotics, and therefore may be used as an active ingredient of an antibacterial adjuvant that can be used in combination with antibiotics to treat bacteria resistant to antibiotics.

[0027] The "antibacterial adjuvant" is also called an "antibiotic adjuvant" and means a substance that increases the antibiotic sensitivity of bacteria, even if it does not directly kill the bacteria, by suppressing the antibiotic resistance of the bacteria or inducing intracellular accumulation of the antibiotic.

[0028] The term "antibiotic" generally refers to a substance having antibacterial activity, and examples of such antibiotics include penicillins, cephalosporins, monobactams, and carbapenems, which are beta-lactam antibiotics having a beta-lactam ring as a basic structure; polymyxins, which exhibit antibacterial effects by changing the permeability of bacterial cell membranes; aminoglycosides, which migrate into the periplasmic space via porin in the outer membrane of gram-negative bacteria and then migrate into cells to exhibit antibacterial effects; macrolides, which bind to the 50S of bacterial ribosomes to inhibit protein synthesis and exhibit antibacterial effects; tetracyclines, which are known as broad-spectrum antibiotics having antibacterial effects against many types of bacteria; glycopeptides, which exhibit antibacterial effects by inhibiting bacterial cell wall biosynthesis; The antibiotic may be any one or more selected from the group consisting of lincomycins, which are isolated from L. lincolnensis and have good antibacterial activity against anaerobic bacteria, quinolones, which exhibit antibacterial effects by interfering with bacterial DNA replication, combinations thereof, and derivatives thereof, and in particular may be a polymyxin antibiotic.

[0029] The polymyxin antibiotics are peptide antibiotics consisting of a large ring carrying a positive charge, and are composed of a heptapebutide ring and three amino acid rings linked with fatty acids. The polymyxin antibiotics are produced by the non-ribosomal peptide synthesis enzyme system in gram-positive bacteria such as Paenibacillus polymyxa, and have the activity of binding to phospholipids present in the outer cell membrane of many gram-negative bacteria, activating phospholipase agents and destroying the cell membrane.

[0030] The polymyxin antibiotic may be polymyxin A, polymyxin B, polymyxin C, polymyxin D and polymyxin E (corstin), in particular B1 ( 56 H98 N 16 O 13 , molecular weight 1203.49) and B2 (C 55 H 96 N 16 O 13 The polymyxin B and polymyxin E have the same structure except that the amino acid linked to the 6th position is phenylalanine (Phe) and leucine (Leu), respectively.

[0031] The bacteria may include, without limitation, any gram-negative bacteria having an outer membrane, and specifically may be pathogenic gram-negative bacteria, such as Escherichia sp., Acinetobacter sp., Pseudomonas sp., or Klebsiella sp. Specifically, the Escherichia bacterium includes, but is not limited to, Escherichia coli, Escherichia albertii, Escherichia blattae, Escherichia fergusonii, Escherichia hermannii, and Escherichia vulneris. The Acinetobacter bacteria include, but are not limited to, Acinetobacter baumannii, Acinetobacter junii, Acinetobacter boissieri, Acinetobacter calcoaceticus, Acinetobacter haemolyticus, Acinetobacter nosocomialis, Acinetobacter schindleri, Acinetobacter ursingii, and the like.The Pseudomonas bacteria include, but are not limited to, Pseudomonas aeruginosa, Pseudomonas fluorescens, Pseudomonas Putida, Pseudomonas chlororaphis, Pseudomonas Pertucinogena, Pseudomonas stutzeri, and Pseudomonas syringae. The Klebsiella genus bacteria includes, but is not limited to, Klebsiella pneumoniae, Klebsiella granulomatis, Klebsiella oxytoca, Klebsiella terrigena, and the like.

[0032] In particular, the bacteria may be resistant to antibiotics, in particular at least one of the antibiotics mentioned above. Such "antibiotic-resistant bacteria" refers to bacteria that are no longer affected or are hardly affected by at least one antibiotic that was previously effective, and that have developed the ability to resist an antibiotic that previously showed effective antibacterial activity. Antibiotic-resistant bacteria can transmit the ability to resist to their progeny. The antibiotic resistance mechanisms are diverse. For example, resistance can be exhibited through an impermeability mechanism that physically prevents the antibiotic from reaching the site of action inside or on the bacteria, an efflux mechanism that quickly removes the antibiotic from the bacteria, thereby preventing an effective amount of the antibiotic from reaching the site of action inside or on the bacteria, a metabolic mechanism that destroys the antibiotic or converts the antibiotic into a harmless (or non-harmful) compound or makes the compound more easily excreted, a bypass mechanism in which the bacteria uses a pathway different from the pathway inhibited by the antibiotic, or a form of the antibiotic target (e.g., an enzyme) that is not sensitive to the antibiotic or a bacteria that does not have the target.

[0033] The antibiotic-resistant bacteria may be resistant to two or more antibiotics, and are also called "multidrug-resistant microorganisms." Examples of the multidrug-resistant bacteria include methicillin-susceptible Staphylococcus aureus (MSSA), methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Staphylococcus aureus (VRSA), vancomycin-intermediate Staphylococcus aureus (VISA), vancomycin-resistant enterococci (VRE), vancomycin-susceptible enterococci (VSE), multidrug-resistant Pseudomonas aeruginosa (MRPA), carbapenem-resistant Pseudomonas aeruginosa (CAMP), and the like. aeruginosa (CRPA), Carbapenem-Resistant Acinetobacter baumannii (CRAB), and Carbapenem-Resistant Enterobacteriaceae (CRE).

[0034] In a specific embodiment of the present invention, it was confirmed that when bacteria resistant to polymyxin antibiotics were treated with a compound represented by Formula 1 in a concentration that does not have antibacterial activity by itself, the death of the bacteria resistant to the polymyxin antibiotics was further promoted. From the above results, it is clear that the compound represented by Formula 1 of the present invention can be used as an active ingredient of an antibacterial adjuvant that further improves the sensitivity of antibiotic-resistant bacteria to antibiotics, thereby restoring the antibacterial activity of the antibiotics.

[0035] Another aspect of the present invention provides an antibacterial adjuvant containing the compound represented by Formula 1 as an active ingredient, and an antibacterial composition containing an antibiotic as an active ingredient.

[0036] As described above, the compound represented by Chemical Formula 1 of the present invention has the effect of improving the susceptibility of antibiotic-resistant bacteria to antibiotics, and the antibacterial activity of the conventional antibiotic can be restored by using the above-mentioned antibacterial adjuvant in combination with the antibiotic.

[0037] When the antibacterial composition of the present invention is administered to antibiotic-resistant bacteria, the expression of genes involved in zinc ion binding, identical protein binding, and ferric ion binding, as well as the expression of genes involved in peroxidase activity, can be significantly decreased, and the expression of genes involved in transport of substances through the cell membrane, in particular, ATPase-coupled sulfate transmembrane transporter activity, can be significantly increased.

[0038] The antibacterial composition of the present invention changes the internal and external environments of bacterial cell membranes, thereby destroying the integrity of the lipid bilayer region of the cell membrane and inducing high depolarization of the cell membrane, disrupting cytoplasmic homeostasis, and ultimately reducing cell permeability and inducing cell death.

[0039] The antibiotic-resistant bacteria may be the same as those described above, in particular a gram-negative bacterium.

[0040] The antibiotic may also be the same as that described above, and may in particular be a polymyxin antibiotic.

[0041] Therefore, the antibacterial composition of the present invention can further improve the antibacterial activity of a polymyxin antibiotic against bacteria resistant to polymyxin antibiotics, compared to when the polymyxin antibiotic is administered alone.

[0042] In a specific embodiment of the present invention, it was confirmed that when an antibacterial adjuvant and a polymyxin antibiotic are used in combination to treat bacteria resistant to polymyxin antibiotics, a synergistic effect is observed, inhibiting bacterial growth, damaging the cell membrane, and inducing bacterial death.

[0043] In addition, the antibacterial composition of the present invention can achieve sufficient antibacterial activity without administering an excessive amount of polymyxin antibiotics because of the use of the antibacterial adjuvant, and therefore has the effect of significantly reducing side effects such as nephrotoxicity caused by the excessive administration of polymyxin antibiotics.

[0044] In a specific embodiment of the present invention, it was confirmed that the combined use of a polymyxin antibiotic, which induces nephrotoxicity, with the antibacterial adjuvant of the present invention not only prevented nephrotoxicity from being induced in a sepsis animal model, but also improved survival rate.

[0045] Another aspect of the present invention provides an antibacterial adjuvant comprising the compound represented by Formula 1 or a pharma- ceutical salt thereof as an active ingredient, and a pharmaceutical composition for preventing or treating organ damage due to sepsis or septic shock comprising an antibiotic as an active ingredient.

[0046] The antibiotic is the same as described above, and may be, in particular, a polymyxin antibiotic. The sepsis or septic shock may be induced by a gram-negative bacterium, and the gram-negative bacterium is not limited as long as it is resistant to an antibiotic, and may be, for example, an Escherichia sp. bacterium and / or an Acinetobacter sp. bacterium.

[0047] The term "sepsis" refers to a condition in which a severe inflammatory response occurs throughout the body due to infection with a microorganism. When two or more of the following symptoms are present: fever, hypothermia, increased respiratory rate (tachypnea), increased heart rate (tachycardia), and increased white blood cell count in a blood test, this is called systemic inflammatory response syndrome (SIRS). When this systemic inflammatory response syndrome is caused by a microbial infection, it is said to be sepsis. In the body's infection focus, pathogenic bacteria continuously or intermittently enter the bloodstream, settle in various organ tissues, create lesions, and show severe systemic symptoms, and the young, elderly, and weak are prone to sepsis. Sepsis can potentially induce septic shock. When sepsis worsens, the function of many organs of the body (heart, kidneys, liver, brain, lungs, etc.) deteriorates, and the condition worsens, leading to shock.

[0048] In a specific embodiment of the present invention, it was confirmed that the survival rate of a sepsis animal model was improved and the number of infected bacteria (CFU) in organs including the liver, lungs, kidneys, and lungs was significantly reduced, demonstrating that the composition comprising the antibacterial adjuvant of the present invention and a polymyxin antibiotic is useful for preventing or treating sepsis.

[0049] The term "prevention" refers to any action for suppressing or delaying the onset of sepsis or septic shock by administering the composition according to the present invention.

[0050] The term "treatment" refers to any action in which the clinical symptoms associated with sepsis and conditions associated with multiple organ dysfunction syndrome (e.g., various degrees of fever, hypoxemia, death, tachycardia, endotheliitis, myocardial infarction, severe confusion, altered mental status, vascular collapse and tracheal damage, acute respiratory distress syndrome, coagulation disorders, cardiac failure, renal failure, shock and / or coma, etc.) are improved or significantly altered by administration of the composition according to the present invention.

[0051] Furthermore, the present invention can suppress organ damage caused by sepsis. The pharmaceutical composition of the present invention can prevent or treat sepsis by suppressing organ damage caused by sepsis. The organ is an organ damaged by sepsis, and there is no limitation on the organ whose organ damage can be suppressed by the composition of the present invention, and may be, for example, at least one selected from the group consisting of the liver, kidney, and lung.

[0052] The pharmaceutical composition according to the present invention may be formulated by adding non-toxic but pharma- ceutically acceptable carriers, reinforcers, excipients, and the like in a conventional manner, and may be manufactured into oral or parenteral preparations such as tablets, capsules, lozenges, liquids, and suspensions.

[0053] In addition, examples of excipients that can be used in the pharmaceutical composition according to the present invention include sweeteners, binders, solubilizers, solubilizing agents, wetting agents, emulsifiers, isotonicity agents, adsorbents, disintegrants, antioxidants, preservatives, lubricants, fillers, and fragrances. Examples of such excipients include lactose, dextrose, sucrose, mannitol, sorbitol, cellulose, glycine, silica, talc, stearic acid, steril, magnesium aluminum silicate, magnesium aluminum silicate, starch, gelatin, tragacanth gum, alginic acid, sodium alginate, methylcellulose, sodium carboxymethylcellulose, agar, water, ethanol, polyethylene glycol, polyvinylpyrrolidone, sodium chloride, calcium chloride, orange essence, strawberry essence, vanilla flavor, and the like.

[0054] The compounds of the present invention may be included at concentration levels ranging from 0.1% to 95% by weight based on the total weight of the pharmaceutical composition, ie, in an amount sufficient to obtain the desired effect.

[0055] The pharmaceutical composition of the present invention may be administered to mammals such as rats, mice, livestock, and humans through various routes. All of the administration methods may be administered, for example, by cutaneous, oral, rectal, intravenous, peritoneal, intramuscular, subcutaneous, intrauterine or intracerebroventricular injection, and preferably, may be administered through any one of oral or intravenous routes, but is not limited thereto.

[0056] The administration may contain one or more active ingredients exhibiting the same or similar functions. For administration, one or more pharma- ceutically acceptable carriers may be added. The pharma-ceutically acceptable carriers may be saline, sterilized water, Ringer's solution, buffered saline, dextrose solution, maltodextrin solution, glycerol, ethanol, or a mixture of one or more of these components, and other common additives such as antioxidants, buffers, bacteriostatic agents, etc. may be added as necessary. In addition, the compound according to the present invention can be easily formulated into various formulations, and for example, it may be formulated into injection forms such as aqueous solutions, suspensions, emulsions, powders, tablets, capsules, pills, granules, or injection solutions by adding diluents, dispersants, surfactants, binders, and lubricants.

[0057] The amount of the compound at the time of administration varies depending on the patient's weight, age, sex, health condition, diet, administration time, administration method, excretion rate and severity of the disease. The daily dose of the compound of the present invention is 0.0001-100 mg / kg, and preferably 0.001-30 mg / kg, which can be administered once or several times a day. At the same time, the administration period may be 1 to 2 months, but may be administered without restrictions until the preventive or therapeutic effect of the disease is shown.

[0058] The antibacterial adjuvant of the present invention improves the sensitivity of gram-negative bacteria to polymyxin antibiotics and can reduce the dosage of polymyxin antibiotics used to inhibit the growth of gram-negative bacteria by up to 128 times, thereby significantly reducing side effects such as nephrotoxicity caused by the overdose of polymyxin. It also shows excellent growth inhibition and killing effects on gram-negative bacteria when administered in combination with polymyxin antibiotics, and allows the polymyxin antibiotics to restore antibacterial activity against gram-negative bacteria that have become resistant to the polymyxin antibiotics. This has the advantage that existing antibiotics can be used as they are without the need to develop a new antibiotic separately.

[0059] Another aspect of the present invention provides a method for preventing, ameliorating, or treating organ damage caused by sepsis or septic shock, comprising administering to an individual an antibacterial adjuvant containing a compound represented by Chemical Formula 1 or a pharma- ceutical acceptable salt thereof as an active ingredient; and a polymyxin antibiotic.

[0060] Yet another aspect of the present invention provides an antibacterial adjuvant comprising, as an active ingredient, a compound represented by Chemical Formula 1 or a pharma- ceutical acceptable salt thereof, and a use of a polymyxin antibiotic for use in the manufacture of a medicament for preventing, ameliorating or treating organ damage due to sepsis or septic shock. EXAMPLES

[0061] The present invention will be described in detail below with reference to examples and experimental examples, but the following examples and experimental examples are provided only to illustrate the present invention and are not intended to limit the scope of the present invention.

[0062] [Example 1] Screening of compounds that increase bacterial susceptibility to polymyxin antibiotics 1-1. Selection of PA108 compounds In the present invention, a substance capable of killing polymyxin-resistant bacteria by acting together with polymyxin was screened using a cellular respiration measurement method among various compounds held in the compound bank of the Korea Research Institute of Chemical Technology. The bacteria used in the experiment were provided by bacteria isolated from a patient with septicemia at Yonsei University Hospital and identified as a polymyxin-resistant and multidrug-resistant strain, Acinetobacter baumannii colistin resistance357 (hereinafter referred to as R357 strain).

[0063] Specifically, a single colony from the LB agar plate on which the bacteria had been grown was inoculated into 3 ml of LB broth and cultured overnight at 37°C at 220 rpm for 16 hours. Then, 50 ml of the culture medium was diluted 1 / 1000 in a 250 ml flask, and 0.5% triphenyltetrazolium chloride (TTC) and 16 μg / mL polymyxin B (PMB) were added and mixed. Next, 198 ul was distributed into a 96-well plate, and each different candidate compound was distributed in 2 ul per well to a final concentration of 5 μM, and mixed, and then observed for 24 hours at 37°C using a phenotype microarray, and the OD value was measured again using a multifunctional microplate reader, and the results were compared.

[0064] As a result, a compound (compound of the following chemical formula 2) was selected that had the activity of increasing the susceptibility of bacteria to polymyxin antibiotics, and this compound was named PA108 and used in subsequent experiments. [ka]

[0065] 1-2. Confirmation of activity of PA108 derivatives as antibacterial adjuvants In order to find the structural relationship of the activity of PA108 compound, a total of 14 PA108 derivatives listed in [Table 1] were prepared, and the synergistic effect of these with PMB was verified by bacterial respiration measurement. PA108 derivatives were either provided by the compound bank of the Korea Research Institute of Chemical Technology or were directly synthesized.

[0066] Specifically, a single colony from the LB agar plate on which the bacteria had been grown was inoculated into 3 ml of LB broth and cultured overnight at 37°C at 220 rpm for 16 hours. Then, 50 ml of the culture medium was diluted 1 / 1000 in a 250 ml flask, and 0.5% triphenyltetrazolium chloride (TTC) and 16 μg / mL polymyxin B (PMB) were added and mixed. Next, 198 ul was distributed into a 96-well plate, and each of the different candidate compounds was distributed in 2 ul per well to a final concentration of 5 μM, and mixed, and then observed for 24 hours at 37°C using a phenotype microarray, and the OD value was measured again using a multifunctional microplate reader, and the results were compared.

[0067] As a result, derivatives other than the original PA108 did not show significant killing effect on the R357 strain (Figure 1).

[0068] [Table 1] JPEG0007621502000005.jpg131149

[0069] [Example 2] Confirmation of bacterial growth inhibition effect of PA108 To confirm the antibacterial activity of PA108, the bacterial growth inhibitory effect was confirmed by measuring the cellular respiration rate using the method used in Example 1.

[0070] First, a single colony from the LB agar plate where the bacteria had been grown was inoculated into 3 ml of LB broth and cultured overnight at 37°C at 220 rpm for 16 hours. Then, 50 ml of the culture was diluted 1 / 1000 in a 250 ml flask, and 0.5% triphenyltetrazolium chloride (TTC) was added and mixed. Then, 198 ul was distributed into a 96-well plate. For each treatment group, 3 wells were divided into 2 ul of PMB 16 μg / mL, PA108 5 μM, PMB (16 μg / mL), and PA108 (5 μM) for 3 replicates, and 2 ul was distributed into each well and mixed, and observed for 24 hours at 37°C using a phenotype microarray. The OD value was measured again using a multifunctional microplate reader, and the results were compared.

[0071] As a result, the R357 strain had a minimal inhibitory concentration (MIC) of 64μg / mL for PMB, confirming that there was no inhibitory effect on cell growth at a low concentration of 16μg / mL (Figure 2, black). It was also confirmed that the developed polymyxin antibacterial adjuvant PA108 also had no inhibitory effect on cell growth at a concentration of 5μM (Figure 2, blue). However, it was confirmed that cellular respiration was effectively inhibited when PMB and PA108 were treated simultaneously (Figure 2, red).

[0072] [Example 3] Confirmation of cell death effect enhanced by PA108 There are two main types of antibiotic efficacy: bacteriostatic, which inhibits the growth of bacteria without killing them, and bactericidal, which kills bacteria. A bacterial viability test was conducted to confirm whether PA108 actually increases the bactericidal effect when treated with polymyxin.

[0073] First, a single colony from the LB agar plate was inoculated into 3 ml of LB broth and cultured overnight at 37°C and 220 rpm for 16 hours. Then, 1% of the culture was diluted into a 250 ml Erlenmeyer flask and cultured until OD = 0.5. The grown culture was divided into three 15 ml round culture tubes, each containing 3 ml, and divided into three treatment groups, namely, PMB 16 μg / mL, PA108 5 μM, PMB (16 μg / mL) and PA108 (5 μM). After culturing at 37°C and 220 rpm, 100 ul of each was smeared on three LB agar plates per treatment group every 1, 4, 7, and 12 hours to confirm the colony forming unit (CFU).

[0074] As a result, similar to the results of cellular respiration, the groups treated with PMB or PA108 alone did not show any killing effect on the R357 strain (Figure 3, black and blue). However, it was confirmed that cell death was induced in the group treated simultaneously with PMB and PA108 (Figure 3, red). Furthermore, it was confirmed that the simultaneous treatment group showed a 107-fold killing effect compared to the control group and the single treatment group at 14 hours, ultimately showing a bacterial killing effect of 99.99999%.

[0075] [Example 4] Confirmation of synergistic antibacterial effect of polymyxin antibiotics and PA108 In order to confirm that synergy was observed when PA108 was co-treated with polymyxin antibiotics, a checkerboard assay was performed, and the fractional inhibitory concentration index (FICI) was calculated from the results.

[0076] First, 3-4 colonies from the LB agar plate were inoculated into 4-5 ml of LB broth and cultured overnight at 37°C at 220 rpm for 16 hours. Then, 5 ml of the culture was diluted 1 / 10000 and cultured in a 15 ml round culture tube at 37°C at 220 rpm until OD = 0.08-0.1. Next, the culture was diluted 1 / 20 and distributed in 196 ul portions into a 96-well plate. PA108 was distributed in 2 ul portions at concentrations of 0-160 μM and PMB was distributed in 2 ul portions at concentrations of 0-64 μg / Ml per well, mixed, and cultured at 37°C for 18 hours, after which the OD was measured using a multifunctional microplate reader.

[0077] Next, to confirm the synergistic effect, the fractional inhibitory concentration index (FIC) index was calculated using the standard equation: Compound A single combination / MIC of compound A + Compound B single combination / MIC of compound B = FIC A + FIC B = FIC Index, which evaluates the effect of the combination of a compound and an antibiotic on the efficacy of the compound and the antibiotic by comparing the MIC value with that of the single compound. The MIC and FIC index are shown in Table 2.

[0078] An FICI value of 0.5 or less is judged to indicate synergy, 0.5 to 4.0 to indicate indifference, and 4 or more to indicate antagonism.

[0079] [Table 2]

[0080] As a result, the FICI value of PA108 and PMB was 0.093, confirming that the effect of killing resistant bacteria was synergistic (Figure 4).

[0081] [Example 5] Morphological cell killing effects of polymyxin antibiotics and PA108 In order to confirm the morphological changes of bacteria when PA108 was treated in combination with polymyxin antibiotics, the morphological changes of bacteria were observed using a fluorescent microscope and a scanning electron microscope.

[0082] First, a single colony from the LB agar plate was inoculated into 3 ml of LB broth and cultured overnight at 37°C at 220 rpm for 16 hours. Then, 1% of the culture was diluted into a 250 ml Erlenmeyer flask and cultured until OD=0.5, after which it was treated with PMB at 16 ug / ml and PA108 at 5 μM and cultured for 9 hours. The cells were centrifuged at 8,000 × g for 10 minutes at 4°C, washed three times, and resuspended in PBS. 3 ml of the cell suspension was fixed and observed under a scanning electron microscope. Using a LIVE / DEAD BacLight bacterial viability kit (Cat #. L7007, Invitrogen, Waltham, Massachusetts, USA), SYTO9 (67 mM, 3 μL), which binds to the DNA and RNA of live cells and emits green fluorescence, and PI (propidium iodide) (1.67 mM, 3 μL), which binds to the DNA and RNA of dead cells and emits red fluorescence, were added to each sample in a final volume of 3 ml, and the samples were incubated in the dark at room temperature for 15 min and observed under a fluorescent microscope.

[0083] As a result, under a fluorescent microscope, green fluorescence was observed in the PMB or PA08 single-treatment group, confirming that cells did not die, similar to the control group, whereas red fluorescence was observed in the PMB and PA108 co-treatment group, confirming that cell death was induced (Figure 5, top).

[0084] In addition, observations using a scanning electron microscope confirmed that the cells treated with PMB or PA08 alone showed intact morphology with no damage to the cell surface, similar to the control group, whereas the cells treated with PMB and PA108 simultaneously showed shortening and leakage of intracellular substances, damaging the morphology and structure of the cells (Figure 5, bottom).

[0085] [Example 6] Confirmation of nephrotoxicity of PA108 Polymyxin antibiotics are known to be nephrotoxic, so we investigated the nephrotoxicity of PMB and PA108 using human renal cell line ACHN (ATCC® CRL-1611). TM ) was used for the measurements.

[0086] First, 2 × 10 ACHN kidney cells were 4 After culturing the cells / well for 24 hours, the medium in all wells was replaced with one containing PMB or PA108. After 0, 24, 48, 72, and 96 hours of PMB or PA108 treatment, cell viability was measured using cell titer glo as the ratio of ATP levels at each time point to 0 hour, and cytotoxicity was evaluated.

[0087] As a result, it was confirmed that the viability of kidney cells decreased at a concentration of 50 μg / mL in the case of PMB (Fig. 6, left). In the case of the polymyxin antibiotic-resistant strain R357, the minimum inhibitory concentration of polymyxin is 64 μg / mL, so it can be predicted that nephrotoxicity should be observed at 64 μg / mL, which is the concentration that shows a therapeutic effect in R357 infection. However, in the case of PA108, it was confirmed that no nephrotoxicity was observed at the working concentration of 5 μM, and that kidney cells showed 80% or more viability even at concentrations higher than this, unlike PMB (Fig. 6, right). Therefore, when PMB and PA108 are treated simultaneously, even when 16 μg / mL PMB is treated, a bactericidal effect is observed against the polymyxin antibiotic-resistant strain R357, so it can be predicted that nephrotoxicity will not be observed when PMB and PA108 are treated together.

[0088] [Example 7] Confirmation of survival rate by PA108 treatment in mouse sepsis model We investigated whether simultaneous treatment of PA108 and PMB in a mouse model infected with the polymyxin antibiotic resistant strain R357 would be effective in treating sepsis induced by R357 infection.

[0089] Specifically, 5x107 R357 strains were intraperitoneally injected into 6-week-old C57BL / 6 mice to create a mouse model of sepsis induced by R357 infection, and 100μg / kg PMB and 60μg / kg PA108 were injected intraperitoneally either alone or in combination to measure the survival rate of the mice.

[0090] As a result, it was confirmed that all mice in the control group, the PMB alone group, and the PA108 alone group died within 42 hours. On the other hand, in the PMB and PA108 co-treatment group, the mice were alive up to 168 hours without showing any pathological phenomena (Figure 7). Furthermore, an autopsy of the mice in the PMB and PA108 co-treatment group revealed that the R357 strain was not detected in the mouse organs, confirming that the R357 strain was completely eliminated by the co-treatment of PMB and PA108.

[0091] [Example 8] Confirmation of efficacy as an antibacterial adjuvant for other species of polymyxin-resistant bacteria In order to confirm whether synergy effects are observed when PA108 is simultaneously treated with polymyxin antibiotics in polymyxin-resistant bacteria of other species other than the R357 strain, a checkerboard assay was performed, and the fractional inhibitory concentration index (FICI) was calculated from the results.

[0092] First, 3 to 4 colonies from each LB agar plate on which bacteria (Klebsiella pneumonia SCH530, SCH740, SCH777, Pseudomonas aeruginosa SMC-U9, SMC-U10, SMC-U11) had been grown were inoculated into 4 to 5 ml of LB broth and cultured overnight at 37°C and 220 rpm for 16 hours. The next day, 5 ml of the culture solution diluted 1 / 10,000 was cultured in a 15 ml round culture tube at 37°C and 220 rpm until OD = 0.08-0.1, and then diluted 1 / 20 and distributed to a 96-well plate at 196 ul each. PA108 was stocked in each well at concentrations ranging from 0 to 80 μM and PMB was stocked at concentrations ranging from 0 to 128 μg / Ml in 2 ul portions, mixed, and then cultured at 37°C for 18 hours. The OD value was measured using a multifunctional microplate reader.

[0093] Next, the FICI was calculated in the same manner as described in Example 4, and the MIC and FICI values ​​are shown in Table 3 below.

[0094] [Table 3]

[0095] As a result, the FICI values ​​of PA108 and PMB for all bacterial strains were below 0.5, the standard value indicating a synergistic effect, confirming that the killing effect against other species of Gram-negative bacteria (Klebsiella pneumonia SCH530, SCH740, SCH777, Pseudomonas aeruginosa SMC-U9, SMC-U10, SMC-U11) was a synergistic effect between PA108 and PMB (Figure 8).

[0096] [Example 9] Confirmation of gene expression changes and mechanism of action by simultaneous treatment with polymyxin antibiotics and PA108 When PA108 was co-treated with the polymyxin antibiotic PMB, the changes in expression of key genes involved in the killing of resistant bacteria were confirmed via transcriptome analysis.

[0097] First, a single colony from the LB agar plate was inoculated into 3 ml of LB broth and cultured overnight at 37°C and 220 rpm for 16 hours. Then, 1% of the culture was diluted into a 250 ml Erlenmeyer flask and cultured until OD=0.5. The culture was divided into three 15 ml round culture tubes, each containing 5 ml of PMB at a concentration of 16 ug / ml, PA108 at a concentration of 5 μM, PMB at a concentration of 16 ug / ml, and PA108 at a concentration of 5 μM, and cultured at 37°C and 220 rpm for 1 hour. The bacteria were then washed three times with PBS, centrifuged at 8,000×g for 10 minutes at 4°C, and stored at -80°C.

[0098] Libraries for RNA sequencing were prepared by extracting total RNA using the TruSeq Stranded Total RNA Sample Preparation Kit with Ribo-Zero H / M / R and synthesizing cDNA of 150 bp in size. The quality of the synthesized cDNA library was assessed using an Agilent 2100 BioAnalyzer (Agilent, CA, USA), and paired-end sequencing was performed to sequence both ends of DNA fragments using an Illumina Novaseq 6000 (Illumina, CA, USA) after cluster amplification of denatured templates. For transcriptome data analysis, the reads were filtered, and the filtered reads were mapped to the reference genome using the STAR Aligner v.2.4.0b. Gene expression was then quantified using the KAPA Library Quantification Kit (Kapa Biosystems, MA, USA) according to the manufacturer's library quantification protocol to measure gene expression levels.

[0099] Gene expression levels were measured using Cufflinks v2.1.1 using gene annotation databases to identify differentially expressed genes (DEGs), and gene expression level count data was generated using HTSeq-count v0.6.1p1. The generated data was analyzed using the TCC R package to identify genes with a q-value less than 0.05 as differentially expressed genes.

[0100] Gene Ontology (GO) analysis was performed on genes identified as differentially expressed genes (DEGs), which classifies genes into three categories: biological process, molecular function, and cellular component, to provide information on gene function.

[0101] As a result, significant gene changes were observed in the PMB alone treatment group, the PA108 alone treatment group, and the PMB and PA108 simultaneous treatment group compared to the control group (Figure 9). In addition, GO (Gene Ontology) analysis confirmed that the expression of genes involved in zinc ion binding, identical protein binding, and ferric ion binding, as well as the expression of genes involved in peroxidase activity, were significantly decreased when PMB and PA108 were simultaneously treated, and the expression of genes involved in material transport through the cell membrane, especially ATPase-coupled sulfate transmembrane transporter activity, was significantly increased (Figure 10).

[0102] It is speculated that treatment with low doses of the antibiotic PMB creates a physicochemical environment that allows external substances to penetrate more easily, allowing PA108 to penetrate more easily into the surrounding cytoplasmic space and reducing the expression of genes involved in the function of the cell membrane, which is responsible for protein oxidation and the transport of various nutrients, resulting in a cell killing effect.

[0103] In addition, this leads to a high mutation rate, growth defects, and the induction of intracellular oxidative stress by the reactive oxygen species superoxide and hydrogen peroxide, which act as toxins. It is speculated that the expression of genes related to the activity of reactive oxygen regulatory enzymes, which regulate this, also decreases, disrupting cytoplasmic homeostasis and resulting in cell death.

[0104] In addition, the expression of genes involved in iron ion binding and protein degradation functions and genes involved in the catabolic process of phenylacetic acid is suppressed, siderophore synthesis is suppressed, and it is speculated that PMB and PA108 that have passed through the cell membrane bind to specific proteins and DNA, reducing metabolic functions and resulting in a cell killing effect.

[0105] The antibacterial composition of the present invention improves the fluidity of the cell membrane by treatment with a low concentration of antibiotic (PMB) that does not directly affect bacteria, and a substance (PA108) that enters the cytoplasm through this facilitates the production of reactive oxygen species in the bacteria, disrupting the homeostasis of the cytoplasm, ultimately reducing cell permeability and inducing cell death.

[0106] [Example 10] Confirmation of bacterial membrane changes by simultaneous treatment with polymyxin antibiotics and PA108 Polymyxin E (corstin) exhibits bactericidal activity by specifically binding to LPS (Lipopolysaccharide) and phospholipids in the cell outer membrane of Gram-negative bacteria, and corstin-resistant bacteria are resistant to corstin because the affinity between corstin and the bacterial outer membrane is reduced due to the deformed LPS in the outer membrane. Therefore, we confirmed whether the addition of PA108 causes changes in bacterial membrane potential and permeability.

[0107] Specifically, for sample preparation, colony cultures grown for 16 hours were washed and resuspended in 0.01M PBS at pH 7.4. The absorbance at 600 nm of the bacterial suspension was normalized to 0.5 in the same buffer, and the dye PI (cat.P1304MP, Thermo Fisher Scientific, Waltham, Massachusetts, USA) was added to a final concentration of 1.67 μM. After incubation at 37°C for 30 minutes, 198 μl of fluorescence-indicated bacterial cells were added to a 96-well plate, followed by addition of 16 μg / ml PMB and 2 μl of 5 μM PA108. After incubation for another 30 minutes, the membrane permeability was measured by measuring the fluorescence in a multifunctional microplate reader at a wavelength range of excitation 535 nm and emission 615 nm.

[0108] The cell membrane potential was measured by resuspending the cells in 5 mM HEPES (pH 7.0, +5 mM glucose) and incubating them for 30 min with the voltage-sensitive dye DiSC3(5) (3,3'-Dipropylthiadicarbocyanine Iodide) (50 μM, Cat. D306, Invitrogen, Carlsbad, California). The membrane potential was then measured by measuring the fluorescence using a multifunctional microplate reader.

[0109] The results confirmed that combined treatment with PMB and PA108 altered the bacterial cytoplasmic membrane potential (Fig. 11, right), but did not affect overall membrane permeability (Fig. 11, left).

[0110] These results suggest that low-dose PMB treatment does not cause changes in membrane permeability that would result in bacterial death, but rather destabilizes lipopolysaccharide (LPS) in the outer membrane of gram-negative bacteria, creating a physicochemical environment through which external substances can more easily enter, and that at the same time, treated PA108 flows into the cell membrane, forming ion channels or pores in the cell membrane, inducing high membrane depolarization.

[0111] As a result, it was found that PA108 acts as an antibacterial adjuvant to PMB and plays a role in inducing bacterial death by damaging the lipid bilayer region of the plasma membrane of bacterial cells.

Claims

1. An antibacterial adjuvant for improving the susceptibility of bacteria to polymyxin antibiotics, comprising a compound represented by the following chemical formula 1 or a pharma- ceutical acceptable salt thereof as an active ingredient: 【Chemistry 1】 Where: X is a halogen atom; R １ and R ２ are each independently a hydrogen atom or alkyl having 1 to 6 carbon atoms.

2. X is a chlorine atom, R １ is a hydrogen atom, R ２ The antimicrobial adjuvant of claim 1 , wherein is methyl.

3. 2. The antibacterial adjuvant according to claim 1, wherein the polymyxin antibiotic is polymyxin B or polymyxin E.

4. The antibacterial adjuvant of claim 1 , wherein the bacteria is a gram-negative bacteria.

5. 5. The antibacterial adjuvant of claim 4, wherein the Gram-negative bacterium is a bacterium of the genus Escherichia, Acinetobacter, Pseudomonas or Klebsiella.

6. The bacterium of the genus Escherichia is at least one selected from the group consisting of Escherichia coli, Escherichia albertii, Escherichia blattae, Escherichia fergusonii, Escherichia hermannii, and Escherichia vulneris; The Acinetobacter bacteria include Acinetobacter baumannii, Acinetobacter junii, Acinetobacter boissieri, Acinetobacter calcoaceticus, Acinetobacter haemolyticus, Acinetobacter nosocomialis, Acinetobacter schindreri ... At least one selected from the group consisting of Acinetobacter schindleri and Acinetobacter ursingii; The Pseudomonas sp. bacterium is at least one selected from the group consisting of Pseudomonas aeruginosa, Pseudomonas fluorescens, Pseudomonas putida, Pseudomonas chlororaphis, Pseudomonas pertusinogena, Pseudomonas stutzeri, and Pseudomonas syringae; The antibacterial adjuvant according to claim 5, wherein the Klebsiella bacterium is at least one selected from the group consisting of Klebsiella pneumoniae, Klebsiella granulomatis, Klebsiella oxytoca, and Klebsiella terrigena.

7. The antibacterial adjuvant according to claim 4, wherein the Gram-negative bacteria is a bacterium resistant to a polymyxin antibiotic or a multi-drug resistant bacterium.

8. An antibacterial composition comprising the antibacterial adjuvant according to claim 1 and a polymyxin antibiotic as active ingredients.

9. The antibacterial composition according to claim 8, wherein the composition induces cell death of gram-negative bacteria.

10. The antibacterial composition according to claim 8, wherein the composition induces membrane depolarization in Gram-negative bacterial cells, thereby damaging the cell membrane.

11. 10. A pharmaceutical composition for preventing or treating organ damage caused by sepsis or septic shock, comprising the antibacterial adjuvant according to claim 1 and a polymyxin antibiotic as active ingredients.

12. 12. The pharmaceutical composition of claim 11, wherein the sepsis or septic shock is induced by infection with Escherichia sp. or Acinetobacter sp. bacteria.

13. The pharmaceutical composition according to claim 11, wherein the organ is at least one selected from the group consisting of the liver, the kidney and the lung.

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