Antibacterial agents

Abstract

To provide a new antimicrobial agent.SOLUTION: An antimicrobial agent contains at least one selected from the group consisting of a compound represented by formula (1), prodrugs thereof, salts of them, and solvates of them.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to antibacterial agents and the like. [Background technology]

[0002] Bacterial infections are usually treated with antibacterial agents to bacteriostatically or sterilize causative bacteria. However, the use of antibacterial agents leads to the emergence of drug-resistant bacteria. For example, methicillin-resistant Staphylococcus aureus (MRSA) has emerged in hospitals where antibacterial agents are frequently used, and is known to be a causative agent of mass infections. In addition, although measures against bacterial infections are required in livestock farming, the use of the same antibacterial agent for both humans and livestock promotes the development of multidrug resistance in pathogenic bacteria. For this reason, there is a demand for the development of new antibacterial agents to combat multidrug-resistant bacteria and to prevent the development of multidrug resistance.

[0003] Griseolutein A has been reported to have antibacterial activity against Staphylococcus aureus (Non-Patent Document 1). However, there have been no reports that Griseolutein A can exert an antibacterial effect against drug-resistant bacteria, nor that Griseolutein A can exert an antibacterial effect against gram-negative bacteria. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] Mar. Drugs 2020, 18, 243 Hifnawy et., al. [Non-Patent Document 2] Journal of the Chemical Society D: Chemical Communications, 1970, Issue 21, Page 1423 to 1425. Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a new antibacterial agent. [Means for solving the problem]

[0006] In view of the above problems, the present inventors have conducted extensive research and have found that the above problems can be solved by an antibacterial agent containing at least one selected from the group consisting of a compound represented by the general formula (1) described below, a prodrug thereof, a salt thereof, and a solvate thereof. Based on this finding, the present inventors have conducted further research and have completed the present invention. That is, the present invention includes the following aspects.

[0007] Section 1. General formula (1):

[0008] [ka] An antibacterial agent comprising at least one member selected from the group consisting of a compound represented by the formula:

[0009] Item 2. The antibacterial agent according to Item 1, which is an antibacterial agent against at least one species selected from the group consisting of gram-positive bacteria and gram-negative bacteria.

[0010] Item 3. The antibacterial agent according to Item 1 or 2, which is an antibacterial agent against at least one species selected from the group consisting of drug-resistant bacteria and drug-susceptible bacteria.

[0011] Item 4. The antibacterial agent according to any one of Items 1 to 3, which is an antibacterial agent against Staphylococcus aureus.

[0012] Item 5. The antibacterial agent according to any one of Items 1 to 4, which is an antibacterial agent against Staphylococcus aureus.

[0013] Item 6. The antibacterial agent according to any one of Items 1 to 5, which is a medicine or a reagent.

[0014] Section 7. General formula (1):

[0015] [ka] A bacterium belonging to the genus Streptomyces having an ability to produce a compound represented by the formula:

[0016] Item 8. The Streptomyces bacterium according to Item 7, which is a Streptomyces HEK131 strain (Patent Microorganisms Depositary Center Accession Number: NITE P-03335).

[0017] Item 9. A method for producing a bacteria culture according to the general formula (1):

[0018] [ka] A method for producing a compound represented by the formula:

[0019] Item 10. The method according to Item 9, wherein the culture is a co-culture of the bacterium according to Item 7 or 8 with another bacterium.

[0020] Item 11. The method according to Item 10, wherein the other bacteria is at least one species selected from the group consisting of Tsukamurella bacteria, Corynebacterium bacteria, Rhodococcus bacteria, Gordonia bacteria, Dietzia bacteria, Nocardia bacteria, Skermannia bacteria, Viramzia bacteria, and Mycobacterium bacteria.

[0021] Section 12. General formula (1):

[0022] [ka] A compound represented by the following formula (1): Effect of the Invention

[0023] According to the present invention, a new antibacterial agent can be provided. [Brief description of the drawings]

[0024] [Figure 1] 1 shows the test results of Example 2. The vertical axis shows the relative cell number, and the horizontal axis shows the Griseolutein T concentration. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] In this specification, the expressions "contain" and "comprise" include the concepts of "contain", "include", "consist essentially of" and "consist only of".

[0026] 1.Compound In one aspect, the present invention provides a compound represented by general formula (1):

[0027] [ka] The present invention relates to a compound represented by the formula (hereinafter, sometimes referred to as the "compound of the present invention" or "Griseolutein T"), a prodrug thereof, a salt thereof, or a solvate thereof (hereinafter, sometimes collectively referred to as the "active ingredient of the present invention"). These will be described below.

[0028] A prodrug of the compound of the present invention refers to a compound that is converted into the compound of the present invention by a reaction catalyzed by an enzyme, gastric acid or the like in a living body. Examples of the prodrug of the compound of the present invention include compounds in which the -NH- moiety is acylated, alkylated, or phosphorylated (e.g., compounds in which the -NH- moiety of the compound of the present invention is eicosanoylated, alanylated, alkyl (e.g., pentyl)aminocarbonylated, (5-alkyl (e.g., methyl)-2-oxo-1,3-dioxolen-4-yl)alkoxy (e.g., methoxy)carbonylated, tetrahydrofuranylated, pyrrolidylalkylated (e.g., methyl), pivaloyloxyalkylated (e.g., methyl), acetoxyalkylated (e.g., methyl), or tert-butylated); and compounds in which the hydroxyl group is acylated, alkylated, phosphorylated, or borated (e.g., compounds in which the hydroxyl group of the compound of the present invention is acetylated, palmitoylated, propanoylated, pivaloylated, succinylated, fumarylated, alanylated, or dialkyl (e.g., methyl)aminoalkyl (e.g., methyl)carbonylated); Examples of the compounds include compounds in which the carboxy group is esterified or amidated (for example, compounds in which the carboxy group of the compound of the present invention is alkyl (e.g., ethyl) esterified, aryl (e.g., phenyl) esterified, carboxyalkyl (e.g., methyl) esterified, dialkyl (e.g., methyl) aminoalkyl (e.g., methyl) esterified, pivaloyloxyalkyl (e.g., methyl) esterified, 1-{(alkoxy (e.g., ethoxy) carbonyl) oxy} alkyl (e.g., ethyl) esterified, phthalidyl esterified, (5-alkyl (e.g., methyl)-2-oxo-1,3-dioxolen-4-yl) alkyl (e.g., methyl) esterified, 1-{[(cycloalkyl (e.g., cyclohexyl) oxy) carbonyl] oxy} alkyl (e.g., ethyl) esterified, alkyl (e.g., methyl) amidated, etc.). These compounds can be produced by methods known per se. In addition, the prodrug of the compound of the present invention may be one that is converted to the compound of the present invention under physiological conditions as described in "Drug Development" Vol. 7, "Molecular Design" pp. 163-198, Hirokawa Shoten, 1990.

[0029] The salt of the compound of the present invention and its prodrug is not particularly limited as long as it is a pharmaceutically acceptable salt.The salt may be either an acid salt or a basic salt.Examples of acid salts include inorganic acid salts such as hydrochloride, hydrobromide, sulfate, nitrate, and phosphate; organic acid salts such as acetate, propionate, tartrate, fumarate, maleate, malate, citrate, methanesulfonate, and paratoluenesulfonate; examples of basic salts include alkali metal salts such as sodium salt and potassium salt; and alkaline earth metal salts such as calcium salt and magnesium salt; salts with ammonia; salts with organic amines such as morpholine, piperidine, pyrrolidine, monoalkylamine, dialkylamine, trialkylamine, mono(hydroxyalkyl)amine, di(hydroxyalkyl)amine, and tri(hydroxyalkyl)amine.

[0030] The compound of the present invention and its prodrug, as well as salts thereof, may be in the form of a hydrate or solvate. Examples of the solvent include pharma- ceutically acceptable organic solvents (e.g., ethanol, glycerol, acetic acid, etc.).

[0031] 2. Manufacturing method The compound of the present invention can be synthesized and produced by various methods. The compound of the present invention can be synthesized, for example, by a method appropriately modified by referring to the method described in Non-Patent Document 2. The compound of the present invention can also be preferably produced by a method including a step of recovering a culture of Streptomyces bacteria capable of producing the compound of the present invention. This production method is described below.

[0032] Bombay Recreation Area (Stre ptomyces) were isolated from S. ptomyces. abietis、S. abikoensis、S. aburaviensis、S. baarnensis、S. bacillaris、S. badius、S. cacaoi、S. caelestis、S. caeruleatus、S. candidus、S. decoyicus、S. demainii、S. deserti、S. diastaticus、S. erythraeus、S. erythrogriseus、S. eurocidicus, S. eurocidicus. felleus、S. fenghuangensis、S. ferralitis、S. fervens、S. filamentosus、S. fieldsensis、S. glaucosporus、S. glaucus、S. globisporus、S. glomeratus、S. glomeroaurantiacus、S. hirsutus、S. hokutonensis、S. hoynatensis、S. humidus、S. javensis、S. jietaisiensis、S. jiujiangensis、S. kaempferi、S. kanamyceticus、S. carpasiensis、S. laceyi、S. lacticiproducens、S. laculatispora、S. ladakanum、S. malachitospinus、S. malaysiensis、S. marinus、S. narbonensis、S. nashvillensis、S. netropsis、S. olivaceiscleroticus、S. olivaceoviridis、S. olivaceus、S. olivochromogenes、S. paradoxus、S. parvisporogenes、S. parvulus、S. qinglanensis、S. racemochromogenes、S. radiopugnans、S. rameus、S. sanglieri、S. sannanensis、S. sanyensis、S. tauricus、S. shop、S.Examples of the bacteria of the genus Streptomyces include S. termitum, S. umbrinus, S. variabilis, S. variegatus, S. varsoviensis, S. wedmorensis, S. wellingtoniae, S. werraensis, S. willmorei, S. xanthocidicus, S. xantholiticus, S. xanthophaeus, S. yaanensis, S. yanglinensis, S. yanii, S. zhaozhouensis, S. zinciresistens, and S. ziwulingensis. Particularly preferred examples of the bacteria of the genus Streptomyces include the Streptomyces HEK131 strain (accession number of the Patent Microorganisms Deposit Center: NITE P-03335). The bacteria of the genus Streptomyces can be used alone or in combination of two or more kinds.

[0033] The culture is a culture medium (culture liquid when the medium is liquid) itself (containing bacteria) obtained by a step of culturing a bacterium of the genus Streptomyces, a medium component (culture supernatant when the medium is liquid) obtained from the culture medium through a step of removing bacteria, or a bacterial cell component. In the production of the compound of the present invention, the culture medium itself containing bacteria can be preferably used as the "culture".

[0034] The culture may be a co-culture of Streptomyces bacteria and other bacteria. The other bacteria is preferably a bacterium capable of inducing secondary metabolite production from Streptomyces bacteria. Examples of such bacteria include bacteria having mycolic acid in the cell wall, coryneform bacteria, etc. More specifically, examples of the bacteria include bacteria of the genus Tsukamullera, Corynebacterium, Rhodococcus, Gordonia, Dietzia, Nocardia, Skermania, Williamsia, and Mycobacterium. More specifically, examples of the bacteria include T. pulmonis, C. efficiens, C. glutamicum, G. rubripertincta, R. coprophilus, and R. erythropolis. , R. wratislaviensis, R. zopfii, etc., and among these, more specific examples include T. pulmonis strain TP-B0596, C. efficiens strain NBRC100395, C. glutamicum strain ATCC13869, G. rubripertincta strain JCM3204, R. coprophilus strain JCM3200, R. erythropolis strain NBRC100887, R. wratislaviensis strain JCM9689, R. zopfii strain JCM9919, etc. Among these, bacteria of the genus Tsukamurella are preferred, Tsukamurella pulmonis is more preferred, and Tsukamurella pulmonis TP-B0596 strain is even more preferred.The other bacteria may be used alone or in combination of two or more kinds.

[0035] The method for obtaining the co-culture product is not particularly limited as long as it is a method for culturing the Streptomyces bacteria and other bacteria under conditions that allow them to come into contact with each other. Typically, the Streptomyces bacteria and other bacteria can be added to a liquid medium and cultured.

[0036] The culture can be carried out according to or in accordance with a known culture method for Streptomyces bacteria.

[0037] The medium is not particularly limited, and a known medium for the culture of Streptomyces bacteria can be used as is or after appropriate modification. Examples of liquid media include liquid media (particularly preferably A3M medium) containing 0.2 to 1.0% (preferably 0.4 to 0.6%) glucose, 1.0 to 3.0% (preferably 1.5 to 2.5%) soluble starch, 1.0 to 3.0% (preferably 1.5 to 2.5%) glycerol, 0.1 to 0.3% yeast extract, and 1.0 to 2.0% crushed seeds (e.g. cotton seeds). In addition to these, examples of A11M medium, A16 medium, etc. can also be mentioned. The pH of the medium is, for example, 7.0 to 8.0, preferably 7.0 to 7.5. The medium is usually sterilized by heat (e.g. autoclave).

[0038] The culture temperature is not particularly limited as long as it is a temperature at which Streptomyces bacteria can be cultured, and is, for example, 15 to 45°C, preferably 25 to 35°C.

[0039] The culture time is not particularly limited as long as the compound of the present invention can be produced, and is, for example, 8 hours to 2 weeks, preferably 16 hours to 1 week.

[0040] The culture medium itself, medium components, and bacterial components obtained by culture contain the compound of the present invention, and therefore the compound of the present invention can be obtained by recovering these. It is desirable to purify these, if necessary.

[0041] Purification can be carried out according to or in accordance with a known method. Examples of purification methods include extraction with an organic solvent (e.g., butanol, etc.) and chromatography (e.g., silica gel chromatography, reverse phase chromatography, etc.). Elution is preferably carried out in multiple stages. In the first stage, elution can be preferably carried out with a solvent obtained by adding acetonitrile to an aqueous solution containing trifluoroacetic acid. The concentration of trifluoroacetic acid is relatively low, for example, about 0.05 to 0.2%. It is known that the compound of the present invention is eluted when the acetonitrile concentration is at a certain level or higher (see Example 1-3), and it is preferable to carry out gradient elution or stepwise elution by utilizing this. In the second and subsequent stages, elution can be preferably carried out with a solvent obtained by adding methanol to an aqueous solution containing ammonium acetate. The concentration of ammonium acetate is, for example, about 15 to 25 mM. It is known that the compound of the present invention is eluted when the methanol concentration is at a certain level or higher (see Example 1-3), and it is preferable to carry out gradient elution or stepwise elution by utilizing this. Specifically, purification can be carried out using antibacterial activity (preferably against both gram-positive and gram-negative bacteria) as an indicator (for example, according to or similar to the method in Example 1-3 described below).

[0042] The compound of the present invention can also be obtained by subjecting the compound obtained above as a starting material to a known synthesis reaction or a synthesis reaction analogous thereto.

[0043] 3.Applications The active ingredient of the present invention has antibacterial activity. Therefore, the active ingredient of the present invention can be used as an active ingredient of an antibacterial agent in various fields such as medicine and reagents. Therefore, in one aspect, the present invention relates to an antibacterial agent (sometimes referred to as "antibacterial agent of the present invention" in this specification) containing at least one active ingredient of the present invention.

[0044] The antibacterial agent of the present invention is not particularly limited as long as it contains the active ingredient of the present invention, and may further contain other ingredients as necessary. The other ingredients are not particularly limited as long as they are pharma- ceutically acceptable. The other ingredients include ingredients having pharmacological action as well as additives. Examples of additives include bases, carriers, solvents, dispersants, emulsifiers, buffers, osmotic pressure regulators, absorption enhancers, stabilizers, excipients, binders, disintegrants, lubricants, thickeners, moisturizers, colorants, fragrances, chelating agents, etc.

[0045] The antibacterial agent of the present invention can be used for a wide range of bacteria, including gram-negative and gram-positive bacteria, and drug-resistant and drug-susceptible bacteria. Examples of gram-negative bacteria include Enterobacteriaceae bacteria (e.g., Escherichia, Klebsiella, Salmonella, Shigella, etc.), Acinetobacter, Pseudomonas (e.g., Pseudomonas aeruginosa), Moraxella, Helicobacter, Campylobacter, Aeromonas, Vibrio (e.g., Vibrio cholerae, Vibrio parahaemolyticus), Haemophilus (e.g., Haemophilus influenzae), Neisseria (e.g., Neisseria gonorrhoeae, Neisseria meningitidis), and Bacteroides. Examples of gram-positive bacteria include Staphylococcus genus (e.g., Staphylococcus aureus, Staphylococcus epidermidis, etc.), Enterococcus genus (e.g., Enterococcus genus), Streptococcus genus (e.g., Group A Streptococcus, Group B Streptococcus, Streptococcus pneumoniae, Streptococcus viridans), Bacillus genus (e.g., Bacillus cereus, Bacillus anthracis), Clostridium genus (e.g., Clostridium tetani, Clostridium botulinum, Clostridium difficile), Corynebacterium genus (e.g., Corynebacterium diphtheriae), Listeria genus, Lactobacillus genus, Bifidobacterium genus, Propionibacterium genus (e.g., Propionibacterium acnes, which causes acne), Actinomycetes, etc. Among these, gram-positive bacteria are preferred, Staphylococcus genus is more preferred, and Staphylococcus aureus is even more preferred. The antibacterial agent of the present invention can exert a high antibacterial effect even against drug-resistant bacteria.

[0046] The mode of use of the antibacterial agent of the present invention is not particularly limited, and an appropriate mode of use can be adopted depending on the type of the agent. The antibacterial agent of the present invention can be used, for example, in vitro (e.g., added to a culture medium for cultured cells) or in vivo (e.g., administered to an animal) depending on the application.

[0047] When the antibacterial agent of the present invention is applied to an animal or a cell, the subject of application is not particularly limited, and examples of mammals include humans, monkeys, mice, rats, dogs, cats, rabbits, pigs, horses, cows, sheep, goats, and deer. Examples of cells include animal cells, etc. The types of cells are also not particularly limited, and examples of the cells include blood cells, hematopoietic stem cells and progenitor cells, gametes (sperm, eggs), fibroblasts, epithelial cells, vascular endothelial cells, nerve cells, hepatic cells, keratinocytes, muscle cells, epidermal cells, endocrine cells, ES cells, iPS cells, tissue stem cells, and cancer cells.

[0048] The antibacterial agent of the present invention can take any dosage form suitable for medicines, reagents, etc., for example, oral preparation forms such as tablets (including orally disintegrating tablets, chewable tablets, effervescent tablets, lozenges, jelly drops, etc.), pills, granules, fine granules, powders, hard capsules, soft capsules, dry syrups, liquids (including drinks, suspensions, syrups), and jellies, and parenteral preparation forms such as injection preparations (for example, drip injections (for example, intravenous drip preparations, etc.), intravenous injections, intramuscular injections, subcutaneous injections, and intradermal injections), external preparations (for example, ointments, creams, poultices, and lotions), suppositories, inhalants, eye preparations, eye ointments, nasal drops, ear drops, and liposomes.

[0049] The route of administration of the antibacterial agent of the present invention is not particularly limited as long as the desired effect can be obtained, and examples of such route include enteral administration such as oral administration, tube feeding, and enema administration; and parenteral administration such as intravenous administration, intraarterial administration, intramuscular administration, intracardiac administration, subcutaneous administration, intradermal administration, and intraperitoneal administration.

[0050] The content of the active ingredient in the antibacterial agent of the present invention depends on the mode of use, the subject to which it is applied, the condition of the subject to which it is applied, etc., and is not limited, but can be, for example, 0.0001 to 100% by weight, preferably 0.001 to 50% by weight.

[0051] The dosage of the antibacterial agent of the present invention when administered to humans or animals is not particularly limited as long as it is an effective amount that exerts a medicinal effect, and is usually, in terms of the weight of the active ingredient, generally 0.1 to 1000 mg / kg body weight per day in oral administration, preferably 0.5 to 500 mg / kg body weight per day, and 0.01 to 100 mg / kg body weight per day, preferably 0.05 to 50 mg / kg body weight per day in parenteral administration. The dosage can be appropriately increased or decreased depending on the age, pathological condition, symptoms, etc. of the patient. EXAMPLES

[0052] The present invention will be described in detail below based on examples, but the present invention is not limited to these examples.

[0053] Example 1. Preparation of Griseolutein T Example 1-1. Preparation of culture Streptomyces sp. HEK131 strain (accession number: NITE P-03335) stored at -80°C was streaked onto ISP2 agar medium (1% malt extract, 0.4% yeast extract, 0.4% glucose, 2% agar) and incubated for 3 days at 30°C. Streptomyces sp. HEK131 grown on ISP2 agar medium was inoculated into the agar medium in a K-1 flask containing 100 ml of ISP2 liquid medium (1% malt extract, 0.4% yeast extract, 0.4% glucose), and cultured with rotary shaking at 30°C and 200 rpm for 2 days to prepare a preculture solution in which growth had reached the stationary phase.

[0054] On the other hand, Tsukamurella pulmonis TP-B0596 stored at -80°C was inoculated from a glycerol stock onto ISP2 agar medium and incubated for 2 days at 30°C. T. pulmonis TP-B0596 grown on ISP2 agar medium was inoculated into a K-1 flask containing 100 ml of ISP2 liquid medium and cultured with rotary shaking at 30°C and 200 rpm for 2 days to prepare a preculture solution in which growth had reached the stationary phase.

[0055] A 3% (v / v) preculture of Streptomyces sp. HEK131 and 1% (v / v) preculture of T. pulmonis TP-B0596 were added to A3M liquid medium (0.5% glucose, 2% soluble starch, 2% glycerol, 0.3% yeast extract, 1.5% pharmamedia, 1% Diaion HP-20, pH 7.0), and the mixture was shake-cultured at 30°C and 200 rpm for 1 to 4 days to obtain a co-culture of Streptomyces sp. HEK131 and T. pulmonis TP-B0596 (100 mL x 4 tubes).

[0056] On the other hand, 3% (v / v) preculture solution of Streptomyces sp. HEK131 was added to the A3M liquid medium, and shake culture was carried out at 30°C and 200 rpm for 1 to 4 days to obtain a monoculture of Streptomyces sp. HEK131 (100 mL x 4 tubes).

[0057] <Example 1-2. Extraction> The co-culture and monoculture were each mixed with 1 / 2 volume of 1-butanol at 30°C and 150 rpm for 1 hour. The mixture was dispensed into centrifuge tubes and centrifuged at 4000 rpm for 8 minutes. The upper layers were combined, concentrated in an evaporator, and vacuum dried to obtain 974 mg and 812 mg of butanol extracts from the co-culture and monoculture, respectively.

[0058] <Example 1-3. Purification> The butanol extract of the co-culture (243 mg) was fractionated by preparative HPLC. The column was a Develosil ODS HG-5 (inner diameter 2 cm, length 25 cm) and the solvent was a gradient elution of 20-80-100% (0-60-65 min) MeCN-0.1% TFA, with fractionation every 2 min at a flow rate of 6 mL / min. The fraction eluted at 26-28 min was concentrated to obtain the antibacterial fraction YI-I-136-2 (2.5 mg). The butanol extract of the co-culture (731 mg) was fractionated by preparative HPLC in the same manner to obtain fraction YI-I-173-4 (4.9 mg), which corresponds to YI-I-136-2. The two antibacterial fractions were combined and fractionated by preparative HPLC. The column used was Develosil ODS HG-5 (inner diameter 2 cm, length 25 cm), and the solvent was 20-70-100% (0-50-60 min) MeOH-20 mM NH4OAc gradient elution, and fractionation was performed every 1.5 min at a flow rate of 5 mL / min. The fraction eluted at 49.5-52.5 min was concentrated to obtain the antibacterial fraction YI-I-179-1 (1.6 mg). This fraction was further fractionated by preparative HPLC. The column used was Develosil ODS HG-5 (inner diameter 2 cm, length 25 cm), and the solvent was 25% MeOH-20 mM NH4OAc, and elution was performed at a flow rate of 6 mL / min. The peak eluted at 40.2 min was collected, concentrated, and lyophilized to obtain griseolutein T (0.16 mg).

[0059] The butanol extract (812 mg) of the monoculture was fractionated in two portions by preparative HPLC. A Develosil ODS HG-5 column (2 cm inner diameter, 25 cm long) was used, and the solvent was a gradient elution of 20-80-100% (0-60-65 min) MeCN-0.1% TFA, with fractionation every 2 min at a flow rate of 6 mL / min. The fractions eluting at 22-24 min were combined and concentrated to obtain the fraction YI-II-39-5 (3.5 mg) containing griseolutein T. Because the content of griseolutein T was low, no further purification was performed, and the content was measured using the method shown in 1-4.

[0060] <Example 1-4. Quantitative analysis> Purified griseolutein T was used as a standard sample and quantitative analysis of griseolutein T in fractions during purification was performed under the following conditions: Develosil ODS UG-5 (inner diameter 4.6 mm, length 25 cm), 20-40% (20 min) MeOH-20 mM NH4OAc, 1 mL / min, UV280 nm. The results are as follows. Co-culture derived fraction YI-I-173-4: 2.6 mg / L Fraction YI-II-39-5 from monoculture: 0.16 mg / L.

[0061] <Example 1-5. Structural analysis> The chemical structure of Griseolutein T was determined as follows, mainly by 2D NMR analysis (DQF-COSY, HSQC, HMBC). The thick lines in the figure on the right indicate bonds determined by DQF-COSY, and the arrows indicate C→H correlation in HMBC to determine connections via two or three bonds. The chemical shift values ​​are summarized in the table below.

[0062] [ka]

[0063] [Table 1]

[0064] High-resolution MS (ESI-TOF, positive) revealed m / z 327.0993 (C 17 H 15 N2O5[M-OH] + Calculated for: 327.0975) and m / z 367.0910 (C 17 H 16 N2O6Na [M+Na] + The ion peak of gliseolutein T (calculated value: 367.0901) was observed, and the molecular formula of gliseolutein T was C 17 H 16 Supported N2O6.

[0065] Example 2. Antibacterial activity evaluation in standard strains Glycerol stocks of the test strains (Table 2) stored at -80°C were streaked onto LB agar medium (1% Trypton, 0.5% Yeast Extract, 0.5% NaCl, 1.5% Agar) and incubated overnight at 37°C. The grown test strains were suspended in physiological saline (0.9% NaCl) and adjusted to a McFarland turbidity of 0.5. The adjusted bacterial solutions were diluted 200-fold for NDM6, MCR1, and E. coli, and 50-fold for MRSA with Mueller Hinton II (Cation-Adjusted) medium (0.3% Beef Extract, 1.75% Acid Hydrolysate of Casein, 0.15% Starch) to prepare four types of test bacterial solutions.

[0066] Purified Griseolutein T was dissolved in 10% DMSO aqueous solution to prepare a concentration 10 times the test concentration. As control samples, a mixed aqueous solution of colistin sulfate (test concentration 64 μg / mL) and ampicillin sodium (test concentration 128 μg / mL) and sterile water were also prepared in the same manner. 10 μL of the prepared Griseolutein T solution and 90 μL of the test bacteria solution were mixed in a 96-well flat-bottom multiplate and incubated at 37°C for 18 hours, after which the absorbance at 600 nm was measured. The absorbance of the control sample of sterile water was set to 100%, and the absorbance of the control sample of the mixed aqueous solution of colistin sulfate and ampicillin sodium was set to 0%, and the relative cell number (%) was calculated.

[0067] [Table 2]

[0068] The results are shown in Figure 1. It was found that Griseolutein T exhibits antibacterial effects against both gram-positive and gram-negative bacteria, as well as against various drug-resistant bacteria.

[0069] Example 3. Antibacterial activity evaluation on clinically isolated strains Glycerol stocks of 87 test strains (Table 3) of different origins stored at -80°C were streaked onto LB agar medium (1% Trypton, 0.5% Yeast Extract, 0.5% NaCl, 1.5% Agar) and incubated overnight at 37°C. Each test strain that grew on the agar medium and formed a single colony was streaked onto another LB agar medium and incubated overnight at 37°C. Each grown test strain was suspended in Mueller Hinton II (Cation-Adjusted) medium and adjusted to a McFarland turbidity of 0.5. The adjusted bacterial solution was diluted 180-fold with Mueller Hinton II (Cation-Adjusted) medium to prepare 87 test bacterial solutions.

[0070] Purified Griseolutein T was dissolved in 10% DMSO aqueous solution to prepare a 10-fold concentration of the test concentration, and then purified Griseolutein T was dissolved in 10% DMSO aqueous solution to prepare a 10-fold concentration of the test concentration. As control samples, a mixed aqueous solution of colistin sulfate (test concentration 64 μg / mL) and ampicillin sodium (test concentration 128 μg / mL) and sterile water were also prepared in the same manner. 10 μL of the prepared Griseolutein T solution and 90 μL of the test bacteria solution were mixed in a 96-well round-bottom multi-plate and incubated at 37°C for 18 hours, and the growth amount was determined from the bacterial precipitation that occurred at the bottom of the 96-well round-bottom multi-plate. If the amount of bacterial precipitation was the same as that of the negative control (sterile water (no drug)), it was judged as "no effect", if the amount of bacterial precipitation was less than that of the negative control, it was judged as "growth inhibition", and if no bacterial precipitation was observed, it was judged as "growth inhibition".

[0071] [Table 3]

[0072] The results are shown in Table 4. It was found that Griseolutein T can exert an antibacterial effect against both drug-resistant and drug-susceptible bacteria, as well as against various types of drug-resistant bacteria. It was also found that Griseolutein T can exert a particularly strong antibacterial effect against Staphylococcus aureus. Considering the results of Example 1 (Figure 1), it is believed that the antibacterial effect can be confirmed by increasing the concentration even against strains for which the effect was not confirmed in this test.

[0073] [Table 4]

Claims

1. General formula (1): 【Chemistry 1】 An antibacterial agent comprising at least one member selected from the group consisting of a compound represented by the formula:

2. The antibacterial agent according to claim 1, which is an antibacterial agent against at least one species selected from the group consisting of gram-positive bacteria and gram-negative bacteria.

3. The antibacterial agent according to claim 1 or 2, which is an antibacterial agent against at least one species selected from the group consisting of drug-resistant bacteria and drug-susceptible bacteria.

4. The antibacterial agent according to any one of claims 1 to 3, which is an antibacterial agent against Staphylococcus aureus.

5. The antibacterial agent according to any one of claims 1 to 4, which is an antibacterial agent against Staphylococcus aureus.

6. The antibacterial agent according to any one of claims 1 to 5, which is a medicine or a reagent.

7. General formula (1): 【Chemistry 2】 The bacterium of the genus Streptomyces is a strain HEK131 (accession number of the Patent Microorganisms Deposit Center: NITE P-03335) capable of producing a compound represented by the formula:

8. The method of claim 7, further comprising the step of recovering a culture of the bacterium according to the general formula (1): 【Chemistry 3】 A method for producing a compound represented by the formula:

9. 9. The method of claim 8, wherein the culture is a co-culture of the bacterium of claim 7 with another bacterium.

10. The method according to claim 9, wherein the other bacteria is at least one selected from the group consisting of Tsukamurella bacteria, Corynebacterium bacteria, Rhodococcus bacteria, Gordonia bacteria, Dietzia bacteria, Nocardia bacteria, Skermannia bacteria, Viramzia bacteria, and Mycobacterium bacteria.

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