Antibacterial agent

Abstract

The objective is to provide a means that can exert antibacterial effects more efficiently against bacteria. [Solution] An antimicrobial agent containing at least two compounds selected from the group consisting of trans-2-methyl-2-pentenal, 2-methylbutanal, trans-2-hexenal, propylaldehyde, 3-methylpentanol, and 2,5-dimethylfuran.

Description

Technical Field

[0001] Relates to antibacterial agents.

Background Art

[0002] Conventionally, various antibacterial preparations have been known. For example, Patent Document 1 reports an antibacterial freshness-retaining agent containing diacetyl, thymol, trans-2-hexenal, trans-2-hexenyl acetate, linalool, 1,8-cineole, acetoin or derivatives thereof. Patent Document 2 reports a volatile material having antibacterial properties and freshness retention containing capillin. Patent Document 3 reports an antibacterial agent containing 2,2-dimethyl-1-(2-hydroxy-1-methylethyl)propyl 2-methylpropanoate or a derivative thereof. Patent Document 4 reports an antibacterial or antiviral agent containing 2-cyclohexen-1-one, α-angelica lactone, 2-cyclopenten-1-one, trans,trans-2,4-hexadienal, propionaldehyde, butyraldehyde, a branched-chain aldehyde or a cyclic aldehyde having a molecular weight of 150 or less.

[0003] Thus, although conventional antibacterial preparations are known, it is important to further develop more useful antibacterial agents.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0005] The objective is to provide a means that can exert antibacterial effects more efficiently against bacteria. [Means for solving the problem]

[0006] As a result of diligent research, the inventors have found that when two compounds selected from trans-2-methyl-2-pentenal, 2-methylbutanal, trans-2-hexenal, propylaldehyde, 3-methylpentanol, and 2,5-dimethylfuran are combined, the antibacterial effect is synergistically enhanced. Furthermore, the inventors have found that these compounds are volatile and can impart antibacterial activity to target objects even in a volatile state. The present invention was completed through further research based on these findings, and this disclosure includes, for example, the inventions described below.

[0007] Item 1. An antimicrobial agent containing at least two compounds selected from the group consisting of trans-2-methyl-2-pentenal, 2-methylbutanal, trans-2-hexenal, propylaldehyde, 3-methylpentanol, and 2,5-dimethylfuran. Item 2. An antimicrobial agent as described in Item 1, which is an antimicrobial agent for spaces, an antimicrobial agent for articles, an antimicrobial agent for external use, or an antimicrobial agent for food. Item 3. Use of at least two compounds selected from the group consisting of trans-2-methyl-2-pentenal, 2-methylbutanal, trans-2-hexenal, propylaldehyde, 3-methylpentanol, and 2,5-dimethylfuran for antimicrobial purposes in spaces, articles, skin, or food. Item 4. An antimicrobial method comprising the step of treating an object to be antimicrobially treated with at least two compounds selected from the group consisting of trans-2-methyl-2-pentenal, 2-methylbutanal, trans-2-hexenal, propylaldehyde, 3-methylpentanol, and 2,5-dimethylfuran. Item 5. Use of at least two compounds selected from the group consisting of trans-2-methyl-2-pentenal, 2-methylbutanal, trans-2-hexenal, propylaldehyde, 3-methylpentanol, and 2,5-dimethylfuran for the manufacture of an antimicrobial agent. [Effects of the Invention]

[0008] This disclosure provides novel antimicrobial agents. This disclosure provides antimicrobial agents in which antimicrobial activity is synergistically enhanced. [Modes for carrying out the invention]

[0009] The embodiments included in this disclosure are described in further detail below. In this disclosure, “contains” also means “substantially consists of” or “consists of.”

[0010] This disclosure includes antimicrobial agents containing at least two compounds selected from the group consisting of trans-2-methyl-2-pentenal, 2-methylbutanal, trans-2-hexenal, propylaldehyde, 3-methylpentanol, and 2,5-dimethylfuran. Hereinafter, these antimicrobial agents may be referred to as the antimicrobial agents of this disclosure.

[0011] Trans-2-methyl-2-pentenal is a compound registered under CAS number 14250-96-5, with the molecular formula C6H 10 It is a volatile compound represented by O.

[0012] 2-Methylbutanal is a compound registered under CAS number CAS 96-17-3, with the molecular formula C5H 10 It is a volatile compound represented by O.

[0013] Trans-2-hexenal is a compound registered under CAS number 6728-26-3, with the molecular formula C6H 10 It is a volatile compound represented by O.

[0014] Propyl aldehyde is a compound registered under CAS number 123-38-6 and is a volatile compound represented by the molecular formula C3H6O.

[0015] 3-Methylpentanol is a compound registered under CAS number 77-74-7 and is a volatile compound represented by the molecular formula C6H 14 O.

[0016] 2,5-Dimethylfuran is a compound registered under CAS number 625-86-5 and is a volatile compound represented by the molecular formula C6H8O.

[0017] The antibacterial agent of the present disclosure contains, as an active ingredient, at least two compounds selected from the group consisting of trans-2-methyl-2-pentenal, 2-methylbutanal, trans-2-hexenal, propyl aldehyde, 3-methylpentanol, and 2,5-dimethylfuran. The antibacterial agent of the present disclosure is not limited as long as it contains two or more of these compounds, and contains two to six of these compounds. The antibacterial agent of the present disclosure is exemplified as preferably containing two to five, more preferably two to four, still more preferably two or three, and particularly preferably two of these compounds.

[0018] In the antibacterial agent of the present disclosure, the content of the above compound is not limited, and as the total amount of the above compound, 0.001% by mass or more and 100% by mass or less are exemplified. In the antibacterial agent, the content of the above compound is preferably 0.001% by mass or more and 50% by mass or less, more preferably 0.001% by mass or more and 30% by mass or less, still more preferably 0.001% by mass or more and 10% by mass or less as the total amount of the above compound.

[0019] When the antibacterial agent of the present disclosure contains trans-2-methyl-2-pentenal, the content of trans-2-methyl-2-pentenal is not limited, but 0.001% by mass or more and 50% by mass or less are exemplified. In the antibacterial agent, as the content, more preferably 0.005% by mass or more and 50% by mass or less, still more preferably 0.01% by mass or more and 10% by mass or less are exemplified.

[0020] When the antibacterial agent of the present disclosure contains 2-methylbutanal, the content of 2-methylbutanal is not limited, but preferably, examples thereof include 0.001% by mass or more and 50% by mass or less. In the antibacterial agent, as the content, more preferably, examples thereof include 0.005% by mass or more and 50% by mass or less, and still more preferably, 0.01% by mass or more and 10% by mass or less.

[0021] When the antibacterial agent of the present disclosure contains trans-2-hexenal, the content of trans-2-hexenal is not limited, but preferably, examples thereof include 0.0005% by mass or more and 50% by mass or less. In the antibacterial agent, as the content, more preferably, examples thereof include 0.001% by mass or more and 30% by mass or less, and still more preferably, 0.001% by mass or more and 10% by mass or less.

[0022] When the antibacterial agent of the present disclosure contains propionaldehyde, the content of propionaldehyde is not limited, but preferably, examples thereof include 0.0005% by mass or more and 50% by mass or less. In the antibacterial agent, as the content, more preferably, examples thereof include 0.001% by mass or more and 10% by mass or less, and still more preferably, 0.005% by mass or more and 5% by mass or less.

[0023] When the antibacterial agent of the present disclosure contains 3-methylpentanol, the content of 3-methylpentanol is not limited, but preferably, examples thereof include 0.001% by mass or more and 50% by mass or less. In the antibacterial agent, as the content, more preferably, examples thereof include 0.005% by mass or more and 50% by mass or less, still more preferably, 0.01% by mass or more and 20% by mass or less, and particularly preferably, 0.1% by mass or more and 10% by mass or less.

[0024] When the antibacterial agent of the present disclosure contains 2,5-dimethylfuran, the content of 2,5-dimethylfuran is not limited, but preferably, examples thereof include 0.001% by mass or more and 50% by mass or less. In the antibacterial agent, as the content, more preferably, examples thereof include 0.005% by mass or more and 20% by mass or less, and still more preferably, 0.01% by mass or more and 1% by mass or less.

[0025] Without limiting the scope of this disclosure, an example of an embodiment of the antimicrobial agent of this disclosure is an antimicrobial agent containing trans-2-methyl-2-pentenal and 2-methylbutanal. The content of the compounds in the antimicrobial agent is not limited, but for example, a preferred amount is 0.1 parts by mass or more and 10 parts by mass of 2-methylbutanal per 1 part by mass of trans-2-methyl-2-pentenal. More preferably, a preferred amount is 0.5 parts by mass or more and 8 parts by mass of 2-methylbutanal per 1 part by mass of trans-2-methyl-2-pentenal, even more preferably 0.8 parts by mass or more and 5 parts by mass, and particularly preferably 1 part by mass or more and 3 parts by mass of 2-methylbutanal.

[0026] As an example of an embodiment of the antimicrobial agent of this disclosure, an antimicrobial agent containing trans-2-methyl-2-pentenal and 3-methylpentanol is preferably mentioned. The content of the compounds in the antimicrobial agent is not limited, but for example, a preferred amount is 0.1 parts by mass or more and 15 parts by mass of 3-methylpentanol per 1 part by mass of trans-2-methyl-2-pentenal. In the antimicrobial agent, a preferred amount is 0.5 parts by mass or more and 10 parts by mass of 3-methylpentanol per 1 part by mass of trans-2-methyl-2-pentenal, and even more preferably 1 part by mass or more and 10 parts by mass.

[0027] As an example of an embodiment of the antimicrobial agent of this disclosure, an antimicrobial agent containing trans-2-methyl-2-pentenal and 2,5-dimethylfuran is preferably mentioned. The content of the compounds in the antimicrobial agent is not limited, but for example, a preferred amount is 0.01 parts by mass or more and 10 parts by mass of 2,5-dimethylfuran per 1 part by mass of trans-2-methyl-2-pentenal. In the antimicrobial agent, a preferred amount is 0.1 parts by mass or more and 5 parts by mass of 2,5-dimethylfuran per 1 part by mass of trans-2-methyl-2-pentenal, and even more preferably 0.1 parts by mass or more and 1 part by mass of 2,5-dimethylfuran.

[0028] As an example of an embodiment of the antimicrobial agent of this disclosure, an antimicrobial agent containing 2-methylbutanal and 2,5-dimethylfuran is preferably cited. The content of the compounds in the antimicrobial agent is not limited, but for example, 0.01 parts by mass to 10 parts by mass of 2,5-dimethylfuran per 1 part by mass of 2-methylbutanal is preferably exemplified. In the antimicrobial agent, 0.1 parts by mass to 5 parts by mass, and even more preferably 0.1 parts by mass to 1 part by mass of 2,5-dimethylfuran per 1 part by mass of 2-methylbutanal is exemplified.

[0029] Furthermore, as an example of an embodiment of the antimicrobial agent of this disclosure, an antimicrobial agent containing trans-2-hexenal and propylaldehyde is preferably cited. The content of the compounds in the antimicrobial agent is not limited, but for example, a preferred amount is 0.1 parts by mass or more and 10 parts by mass of propylaldehyde per 1 part by mass of trans-2-hexenal. In the antimicrobial agent, a preferred amount is 0.5 parts by mass or more and 10 parts by mass of propylaldehyde per 1 part by mass of trans-2-hexenal, and even more preferably 0.5 parts by mass or more and 5 parts by mass of propylaldehyde.

[0030] All of the aforementioned compounds are known to be volatile, and in this disclosure, the content refers to the amount at the time of manufacture (formulation) of the antimicrobial agent. The same applies hereinafter.

[0031] In this disclosure, volatility means volatilizing at room temperature and atmospheric pressure (20°C, 1 atm).

[0032] The types of bacteria targeted by the antimicrobial agents of this disclosure are not particularly limited and may include either Gram-negative or Gram-positive bacteria. Examples of Gram-negative bacteria include Escherichia bacteria such as Escherichia coli, Klebsiella bacteria such as Klebsiella pneumoniae, Pseudomonas bacteria such as Pseudomonas aeruginosa, Salmonella bacteria, Vibrio bacteria, and Acinetobacter bacteria. Preferably, examples of Gram-negative bacteria include Escherichia bacteria and Klebsiella bacteria. Examples of Gram-positive bacteria include Staphylococcus bacteria such as Staphylococcus aureus, Bacillus bacteria, Listeria bacteria, and Alicyclobacillus bacteria. Preferably, examples of Gram-positive bacteria include Staphylococcus bacteria. Examples of bacteria that are preferably Gram-negative include those described.

[0033] In this disclosure, "antimicrobial" means reducing the activity of bacteria, thereby inhibiting bacterial growth or causing bactericidal effects.

[0034] The antimicrobial agents of this disclosure may be in liquid, semi-solid, or solid form, but are preferably liquid or semi-solid. The antimicrobial agents of this disclosure may further contain any other components as needed, to the extent that they do not interfere with the effects of this disclosure. Examples of such other components include solvents (water, methanol, ethanol, propanol, propylene glycol, 1,3-butylene glycol, glycerin, 3-methoxy-3-methyl-1-butanol, paraffinic hydrocarbons (liquid isoparaffin, liquid normal paraffin), propylene glycol monomethyl ether, etc.), gelling agents, oils, surfactants, antioxidants, pH adjusters, fragrances, colorants, deodorants, antimicrobial agents other than the compounds mentioned above, cooling agents, UV absorbers, humectants, insecticidal components, insect repellent components, repellent components, etc. These other components may be used individually or in combination of two or more, and the content of these other components may be determined as appropriate.

[0035] The antimicrobial agents of this disclosure can be manufactured by mixing two or more of the aforementioned compounds according to a manufacturing procedure conventionally known in the art, depending on the form of the antimicrobial agent, the target of application, etc., and by mixing in other components as necessary.

[0036] The antimicrobial agents of this disclosure are used to impart antimicrobial activity to objects where antimicrobial activity is required by treatment. The antimicrobial agents of this disclosure may also be used to improve the preservation properties of objects where antimicrobial activity is required by treatment. The objects may be those on which bacteria are present or attached, or those on which bacteria are not present or attached, and the scope of application also includes objects on which the attachment or growth of bacteria is to be suppressed. The antimicrobial agents of this disclosure can be used by spraying, volatilizing, coating, etc., onto the object. The antimicrobial agents of this disclosure may also be used by impregnating nonwoven fabrics, woven fabrics, paper, wood, etc.

[0037] Preferred examples of applications include spaces, articles, the human body, and food. Accordingly, preferred examples of antimicrobial agents in this disclosure include antimicrobial agents for spaces (antimicrobial agents for spaces), antimicrobial agents for articles (antimicrobial agents for articles), antimicrobial agents for the human body (antimicrobial agents for external use), and antimicrobial agents for food (antimicrobial agents for food).

[0038] Without limiting this disclosure, to illustrate with an example of the antimicrobial agent used in this disclosure when targeting a space, antimicrobial activity can be imparted to the space by treating it with the antimicrobial agent. Furthermore, by treating the space with the antimicrobial agent, antimicrobial activity can be imparted not only to the space but also to articles present within the space.

[0039] Preferably, the spaces to which this invention can be applied are enclosed spaces separated from the outdoors, such as trash cans and shoe racks; indoor spaces such as living rooms, toilets, bathrooms, washrooms, entrances, and closets; interior spaces of automobiles, buses, and trucks; and facility spaces such as restaurants, factories, offices, and conference rooms. Examples of items to which this invention can be applied include trash cans, electrical appliances, sinks, curtains, carpets, wallpaper, sofas, chairs, desks, storage furniture, toilets, bathtubs, washbasins, bedding, clothing, shoes, leather goods, doors, floors, windows, ceilings, handrails, toys such as stuffed animals, and pet supplies. A preferred example of an area to which this invention can be applied is a space where trash cans, toilets, etc., are installed, or a space or item where the presence or proliferation of bacteria in trash cans, etc., is likely to cause problems such as unsanitary conditions or unpleasant odors. Treating a space with the antimicrobial agent of this disclosure can help prevent, mitigate, or eliminate these problems.

[0040] Examples of treating a space with the antimicrobial agent of this disclosure include spraying, volatilizing, and coating the antimicrobial agent within the space, with spraying and volatilizing being preferred examples due to their ease of use. The form of the antimicrobial agent is not particularly limited; for example, when used by spraying, a liquid form is preferred. When used by letting it stand and volatilizing, a liquid or gel form is exemplified, and the liquid or gel form of the antimicrobial agent may be impregnated into a carrier such as a nonwoven fabric, woven fabric, paper, or wood and then volatilized. When spraying the antimicrobial agent into a space, it may be sprayed as a spray product or aerosol product containing the antimicrobial agent in a spray container, aerosol container, etc. When letting the antimicrobial agent stand and volatilize, it may be left in the space in a volatilizable state in the same manner as conventional known stationary air fresheners, etc.

[0041] When the antimicrobial agent of this disclosure is used for antimicrobial purposes in a space, the content of the compound used as an active ingredient in the antimicrobial agent is described in the same manner as above and may be set appropriately depending on the shape of the antimicrobial agent, the type and size of the space to which it is applied, etc. Examples of the total content (amount) of the compound in the antimicrobial agent include preferably 0.1% by weight or more and 99.9% by weight or less, more preferably 0.5% by weight or more and 90% by weight or less, and even more preferably 1% by weight or more and 80% by weight or less.

[0042] When the antimicrobial agent of this disclosure is used for antimicrobial purposes in a space, it is preferable that the antimicrobial agent contains a solvent that is volatile at room temperature (20°C), and the solvent is exemplified in the same manner as described above. Examples of the solvent include water, 3-methoxy-3-methyl-1-butanol, paraffinic hydrocarbons (liquid isoparaffin, liquid normal paraffin), propylene glycol monomethyl ether, etc. The antimicrobial agent may contain other components besides the solvent. Examples of other components include gelling agents, surfactants, etc., as described above. As described above, the other components may be used individually or in combination of two or more.

[0043] To illustrate the antimicrobial agent of this disclosure with an example of an antimicrobial agent targeting articles, by treating an article with the antimicrobial agent, an antimicrobial effect can be imparted to the article.

[0044] Examples of articles to which this invention applies include, but are not limited to, hard surfaces such as toilets, bathtubs, washbasins, sinks, tiles, and glass; textile products such as cloth sofas, bedding, clothing, curtains, masks, diapers, hand towels, and carpets; building structures such as wallpaper, doors, handrails, floors, windows, and ceilings; trash cans, chairs, desks, electrical appliances, storage furniture, shoe racks, shoes, leather products, and pet supplies, with hard surfaces and textile products being preferred examples. In this disclosure, a hard surface means the surface of a hard material such as resin (plastic, etc.), ceramics, or glass. Furthermore, examples of articles to which this invention applies include trash cans and used diapers, which are prone to problems such as unsanitary conditions or unpleasant odors due to the presence or growth of bacteria. Treating articles with the antimicrobial agent of this disclosure can lead to the prevention, reduction, or elimination of such problems.

[0045] Examples of treatment of articles with the antimicrobial agent of this disclosure include spraying, coating, and volatilization of the antimicrobial agent onto the article, with spraying and coating being preferred. The form of the antimicrobial agent is not particularly limited; for example, when used by spraying, a liquid form is preferred; when used by coating, a liquid or gel form is preferred; and when allowed to stand and volatilize, a liquid or gel form is preferred. When spraying the antimicrobial agent, as described above, the antimicrobial agent may be contained in a spray container, aerosol container, etc., and sprayed. When allowing the antimicrobial agent to stand and volatilize, as described above, the antimicrobial agent may be left in a space in a state where it can volatilize in the same manner as conventional methods. The antimicrobial agent may also be impregnated into a carrier such as a sheet of nonwoven fabric, woven fabric, or filter paper and used in the form of a wiping sheet for coating, etc.

[0046] When the antimicrobial agent of this disclosure is used for antimicrobial purposes in articles, the content of the compound used as an active ingredient in the antimicrobial agent is described in the same manner as above and may be set appropriately depending on the shape of the antimicrobial agent, the type of article to which it is applied, etc. Examples of the total content (amount) of the compound in the antimicrobial agent include preferably 0.1% by weight or more and 99.9% by weight or less, more preferably 0.5% by weight or more and 99% by weight or less, and even more preferably 1% by weight or more and 80% by weight or less.

[0047] When the antimicrobial agent of this disclosure is used for antimicrobial purposes in articles, it is preferable that the antimicrobial agent contains a solvent that is volatile at room temperature, and the solvent is exemplified in the same manner as described above. Examples of the solvent include water, ethanol, propanol, etc. The antimicrobial agent may also contain other components besides the solvent. Examples of these components include gelling agents, surfactants, etc., as described above. As described above, the other components may be used individually or in combination of two or more.

[0048] To illustrate the antimicrobial agents of this disclosure with an example of an antimicrobial agent for use on the body, treatment of the body with this antimicrobial agent can improve or prevent deterioration of the body's hygiene. The body is preferably exemplified by skin (including hair and nails), which may be human skin or the skin of non-human animals (non-human mammals, birds, reptiles, etc.). Human skin is preferably exemplified as the target of application.

[0049] Preferred methods for treating the body with the antimicrobial agent of this disclosure include spraying or applying the antimicrobial agent to the skin. The form of the antimicrobial agent is not particularly limited; for example, when used by spraying, a liquid form is preferred, and when used by applying, a liquid or gel form is preferred. When spraying the antimicrobial agent, it may be contained in a spray container, aerosol container, etc., as described above and sprayed. The antimicrobial agent may also be impregnated into a carrier such as a sheet of nonwoven fabric, woven fabric, or filter paper, and applied to the body in the form of a wipe sheet.

[0050] When the antimicrobial agent of this disclosure is used for antimicrobial purposes on the body, the antimicrobial agent may be in any formulation form, such as a topical drug, cosmetic, or skin cleanser, as long as it is applicable to the body. Examples of formulation forms include topical drugs such as liquids, emulsions, creams, lotions, gels, poultices, patches, liniments, sprays, aerosols, ointments, packs, and hand sanitizers; cosmetics such as lotions, emulsions, serums, aqueous ointments, creams, gels, and packs; and skin cleansers such as body shampoos, hair shampoos, conditioners, and cleansing wipes.

[0051] When the antimicrobial agent of this disclosure is used for antimicrobial purposes on the body, the content of the compound used as the active ingredient in the antimicrobial agent is described in the same manner as above and may be set appropriately depending on the formulation form, etc. Examples of the total content (amount) of the compound in the antimicrobial agent include preferably 0.05% by weight or more and 50% by weight or less, more preferably 0.1% by weight or more and 30% by weight or less, and even more preferably 0.2% by weight or more and 10% by weight or less.

[0052] When the antimicrobial agent of this disclosure is used for antimicrobial purposes on the body, the antimicrobial agent may contain a solvent that is volatile at room temperature, and the solvent is exemplified in the same manner as described above, more preferably water, ethanol, etc. The antimicrobial agent may also contain other components other than the solvent. Examples of such components include the gelling agent, surfactant, etc. As described above, the other components may be used individually or in combination of two or more.

[0053] To illustrate the antimicrobial agents of this disclosure with an example of an antimicrobial agent for food, treating food with this antimicrobial agent makes it possible to suppress the deterioration of food's freshness or prevent spoilage. While not limited to food products, preferred examples include fresh foods, prepared foods, bento boxes, and confectionery, which are prone to problems such as deterioration of freshness or spoilage due to the presence or growth of bacteria.

[0054] Examples of food treatment with the antimicrobial agent of this disclosure include volatilization, spraying, and coating of the antimicrobial agent onto the food, with volatilization and spraying being preferred. The form of the antimicrobial agent is not particularly limited; for example, when used by volatilization, a liquid or gel form is preferred. The liquid or gel form of the antimicrobial agent may be impregnated into or blended with a carrier such as a nonwoven fabric, woven fabric, paper, wood, or resin (such as polypropylene) used in conventional food antimicrobial sheets, and then volatilized in the form of a food antimicrobial sheet. When used by spraying, a liquid form is preferred, and as described above, the antimicrobial agent may be contained in a spray container, aerosol container, etc., and sprayed. When used by coating, a liquid or gel form is preferred, and the antimicrobial agent may be impregnated into a carrier such as a sheet of nonwoven fabric, woven fabric, or filter paper, and used for coating in the form of a wiping sheet, etc.

[0055] When the antimicrobial agent of this disclosure is used for antimicrobial purposes in food, the content of the compound used as an active ingredient in the antimicrobial agent is described in the same manner as above and may be set appropriately depending on the shape of the antimicrobial agent, etc. Examples of the total content (amount) of the compound in the antimicrobial agent include preferably 0.1% by weight or more and 99.9% by weight or less, more preferably 0.5% by weight or more and 90% by weight or less, and even more preferably 1% by weight or more and 80% by weight or less.

[0056] When the antimicrobial agent of this disclosure is used for antimicrobial purposes in food, it is preferable that the antimicrobial agent contains a solvent that is volatile at room temperature, and the solvent is exemplified in the same manner as described above. More preferably, the solvent is water, ethanol, propanol, etc. The antimicrobial agent may also contain other components besides the solvent. The surfactant is exemplified in the same manner as described above. As described above, the other components may be used individually or in combination of two or more.

[0057] Therefore, the antimicrobial agent of this disclosure may be used in products where antimicrobial properties are required, for the purpose of improving the shelf life of said products. In this case, the antimicrobial agent can also be said to play a role as a preservative of said products. The said products are not particularly limited, and examples include food, pharmaceuticals, cosmetics, resin products, textile products, paper products, wood products, etc. The form of the antimicrobial agent of this disclosure will be described in the same manner as above, and may be liquid, semi-solid, or solid, and can be determined as appropriate.

[0058] The antimicrobial agent of this disclosure can be used in coexistence with products requiring antimicrobial properties within a container. Within the container, the antimicrobial agent and the product may coexist in contact or in a non-contact manner. Since the compound contained as an active ingredient in the antimicrobial agent of this disclosure is volatile, even in the case of non-contact, the compound volatilizes within the container, thereby exerting antimicrobial and preservative effects on the product. The container is not limited, and examples include conventionally known containers made of resin (polyethylene, polypropylene, polyethylene terephthalate, acrylic resin, etc.), paper, metal such as aluminum and steel, wooden containers, conventionally known food packaging materials, lunch boxes, and various other containers.

[0059] Furthermore, without limiting the scope of this disclosure, for example, if the product is a food, pharmaceutical, or cosmetic, the antimicrobial agent of this disclosure may be incorporated into the product as an additive. For example, if the product is a textile product, resin product, paper product, or wood product, the antimicrobial agent of this disclosure may be mixed (kneaded in, etc.), applied, etc., into the materials used in the manufacture of the product. The content of the antimicrobial agent of this disclosure in the product may be set appropriately depending on the type of product, etc. Examples of the content (total amount) of the compound in the product include preferably 0.05% by weight or more and 50% by weight or less, more preferably 0.1% by weight or more and 30% by weight or less, and even more preferably 0.2% by weight or more and 10% by weight or less.

[0060] Therefore, this disclosure also provides an antimicrobial method comprising the step of treating an object to be treated for antimicrobial purposes using at least two compounds selected from the group consisting of trans-2-methyl-2-pentenal, 2-methylbutanal, trans-2-hexenal, propylaldehyde, 3-methylpentanol, and 2,5-dimethylfuran. The compounds, object, treatment, etc., will all be described in the same manner as described above for antimicrobial agents.

[0061] According to this disclosure, by using two or more of the aforementioned compounds, an antimicrobial agent with synergistically enhanced antimicrobial activity can be provided. By treating a target with the antimicrobial agent of this disclosure, an antimicrobial effect can be imparted to the target, and the antimicrobial agent of this disclosure can also be used for purposes such as preventing spoilage and preservation. Generally, to further enhance the antimicrobial effect against bacteria, it is necessary to increase the concentration of the antimicrobial component, but it is desirable to enhance the antimicrobial effect without increasing the concentration of the antimicrobial component. According to this disclosure, the antimicrobial effect can be synergistically enhanced, so an antimicrobial effect can be efficiently imparted to the target. Furthermore, while non-volatile antimicrobial agents need to be directly attached to or contained in the target before use, the aforementioned compounds contained as active ingredients in the antimicrobial agent of this disclosure are volatile substances. Therefore, the volatile antimicrobial agent is also excellent in terms of ease of use, as an antimicrobial effect can be imparted to the target simply by placing the antimicrobial agent in the space where the target is present and allowing it to volatilize. [Examples]

[0062] The embodiments of this disclosure will be described in more detail below with examples, but the embodiments of this disclosure are not limited to the examples below.

[0063] Test Example 1 1. Test materials and test procedures The antibacterial activity of various compounds (test samples) against bacteria was evaluated according to the following procedure.

[0064] Preparation of test strains and test bacterial solutions Escherichia coli NBRC3972 was used as the test strain. The test strain was streaked onto SCD agar and incubated at 35±1°C for 16-24 hours. Colonies were then picked and streaked onto fresh SCD agar and incubated at 35±1°C for 16-24 hours. The colonies were then suspended in sterile water, and the test bacterial suspension (2.5 × 10⁶) was prepared. 6 ~1.0×10 7 A CFU / mL solution was prepared. The number of bacteria in the test bacterial suspension was measured and calculated using SCD agar medium (32.5°C, cultured for 1-2 days).

[0065] • Preparation of test specimens The test samples were prepared by diluting the stock solution (100%) of the compounds (volatile substances) shown in Table 1 with 1 / 80 NB medium and DMSO (2% DMSO in the diluent) to the concentrations shown in Table 1. For example, the test sample for Example 1 was a test solution obtained by diluting trans-2-methyl-2-pentenal and 2-methylbutanal with 1 / 80 NB medium and DMSO to the concentrations shown in Table 1. For example, the test sample for Comparative Example 1 was a test solution obtained by diluting trans-2-methyl-2-pentenal with 1 / 80 NB medium and DMSO to the concentrations shown in Table 1. In this test example, 1 / 80 NB medium was used as a blank, and 1 / 80 NB medium containing 2% DMSO was used as a control sample.

[0066] • Antimicrobial testing The aforementioned sample or blank (9.9 mL) was mixed with the test bacterial solution (0.1 mL) and thoroughly stirred. The resulting mixture was sealed and left to stand at 35±1°C for 24 hours. The number of bacteria in the mixture after standing was measured. For bacterial count measurement, SCDLP agar medium was used, and the number of colonies after incubation at 32.5°C for 2 days was counted to calculate the bacterial count (CFU / mL).

[0067] • Calculation of antibacterial activity value The antibacterial activity value was calculated according to the following formula 1. A higher antibacterial activity value indicates a stronger antibacterial effect.

[0068]

number

[0069] • Evaluation of antibacterial activity when compound combinations are used. The antibacterial effect of the combined use of the aforementioned compounds was evaluated according to the following formula. If Formula 2 is satisfied, it means that a synergistic antibacterial effect is obtained by combining the aforementioned compounds.

[0070]

number

[0071] 2.Results The results are shown in Table 1.

[0072] [Table 1]

[0073] In Table 1, the values ​​shown in the "Evaluation Results" column are the antibacterial activity values ​​calculated as described above. The evaluation result when using the sample from Comparative Example 1 (trans-2-methyl-2-pentenal alone) was 0.06, and the evaluation result when using the sample from Comparative Example 2 (2-methylbutanal alone) was 0.11. In contrast, the evaluation result when using the sample from Example 1 (trans-2-methyl-2-pentenal and 2-methylbutanal in combination) was 3.33. Applying the evaluation results to Equation 2, we get [3.33] - [0.17(0.06 + 0.11)] = 3.16 ≥ 1. From this, it was confirmed that a synergistic antibacterial effect against bacteria was obtained in Example 1, which used trans-2-methyl-2-pentenal and 2-methylbutanal in combination.

[0074] Furthermore, the evaluation result when using the sample from Example 2 (a combination of trans-2-methyl-2-pentenal and 3-methylpentanol) was 2.69. The evaluation result when using the sample from Comparative Example 1 (trans-2-methyl-2-pentenal alone) was 0.06, and the evaluation result when using the sample from Comparative Example 3 (3-methylpentanol alone) was 1.33. Applying each value to Equation 2, we get [2.69] - [1.39(0.06 + 1.33)] = 1.3 ≥ 1. From this, it was confirmed that a synergistic antibacterial effect against bacteria can be obtained by using the above compounds in combination, even with the sample from Example 2.

[0075] Furthermore, when the evaluation result 3.2 in Example 3, the evaluation result 0.06 in Comparative Example 1, and the evaluation result 0.12 in Comparative Example 4 were applied to Equation 2, the result was [3.2]-[0.18(0.06+0.12)]=3.02≧1. When the evaluation result 2.61 in Example 4, the evaluation result 0.11 in Comparative Example 2, and the evaluation result 0.12 in Comparative Example 4 were applied to Equation 2, the result was [2.61]-[0.23(0.11+0.12)]=2.38≧1. When the evaluation result 2.92 in Example 5, the evaluation result 0.24 in Comparative Example 5, and the evaluation result 0.21 in Comparative Example 6 were applied to Equation 2, the result was [2.92]-[0.45(0.24+0.21)]=2.47≧1. From these results, it was confirmed that a synergistic antibacterial effect against bacteria could be obtained by using the compounds in combination with the samples from Examples 3 to 5.

[0076] This confirms that the antibacterial effect against bacteria can be synergistically enhanced by using the above-mentioned compounds in combination. In particular, in Examples 1 to 5, the calculated value in Formula 2 was 1 or higher, indicating a good synergistic effect in terms of antibacterial activity against bacteria. Furthermore, in Examples 1 and 3 to 5, the calculated value was 2 or higher, indicating an even better synergistic effect in terms of antibacterial activity against bacteria, and in Examples 1 and 3, the calculated value was 3 or higher, indicating a remarkably excellent synergistic effect.

[0077] Test Example 2 1. Test materials and test procedures The antibacterial activity of various compounds (test samples) against bacteria was evaluated according to the following procedure. In this test, a urethane plate (urethane plate) was left to stand in an environment where the compounds (volatile substances) shown in Table 2 were volatilized, and then the antibacterial activity against test bacterial strains was evaluated using the urethane plate. Specifically, the test was conducted as follows.

[0078] Preparation of test strains and test bacterial solutions The same Escherichia coli strain as in Test Example 1 was used as the test strain. The test strain was streaked onto SCD agar and incubated at 35±1°C for 16-24 hours. Then, colonies were picked, streaked onto new SCD agar, and incubated at 35±1°C for 16-24 hours. The formed colonies were suspended in 1 / 80 NB medium, and the test bacterial suspension (2.5 × 10⁶) was prepared. 6 ~1.0×10 7 A solution (CFU / mL) was prepared.

[0079] • Preparation of test specimens The test samples were prepared by diluting the stock solutions of the compounds shown in Table 2 with isoparaffin to the concentrations shown in Table 2. For example, the test sample for Example 6 was a test solution obtained by diluting trans-2-methyl-2-pentenal and 2-methylbutanal with isoparaffin to the concentrations shown in Table 2.

[0080] • Preparation of treated urethane plates and untreated urethane plates for test specimens A cut urethane plate (4.8 cm x 4.8 cm square, 0.2 cm thick) and a glass petri dish (2.6 cm in diameter, 1.2 cm in height, hereinafter referred to as the small petri dish) were placed side by side on the inside bottom of a glass petri dish (8.5 cm in diameter, 3.0 cm in height, hereinafter referred to as the large petri dish). Next, 0.5 mL of the test sample was placed inside the small petri dish, and in this state, i.e., with the urethane plate and the small petri dish (containing the test sample) not in contact, the large petri dish was sealed by covering it with a lid and left to stand for 5 minutes. A urethane plate treated with the test sample was thus prepared. The urethane plate treated with the test sample (hereinafter referred to as the treated plate) was prepared immediately before the antibacterial test described later. An untreated urethane plate was used as the untreated urethane plate (control).

[0081] • Antimicrobial testing A treated urethane plate (n=2 each) or an untreated urethane plate (n=4 each) was placed on the inside bottom of a new petri dish, and 0.4 mL of the test bacterial solution was poured over the urethane plate so that it made uniform contact with the entire surface. Next, a 4 cm x 4 cm piece of film cut from a bacterial testing polybag (bacterial testing polybag for Exnizer 400, manufactured by Organo Co., Ltd.) was placed over the urethane plate. A Kimtowel impregnated with distilled water was placed inside the Tupperware, or a beaker containing distilled water was placed inside, and the petri dish and Tupperware were placed side by side. The treated urethane plates or untreated urethane plates (n=2 each) were left to stand for 24 ± 1 hours in an environment of 35 ± 1 °C and relative humidity of 90% or higher. After standing, the treated urethane plates, untreated urethane plates after standing, or untreated urethane plates that were not stood (0 hours standing) (n=2 each) were collected with tweezers, placed in a sterile stomacher bag, and 10 mL of SCDLP medium was added. The bag was shaken well for 1.5 minutes, holding the edge, to mix the urethane plate and culture medium. After standing for 10 minutes, the surface of the urethane plate was rubbed from the outside of the bag by hand for 1 minute to obtain a bacterial dispersion. The number of bacteria in the bacterial dispersion was then measured and calculated. SCDLP agar medium was used for bacterial counting, and the number of colonies after culturing was counted and calculated in the same manner as in Test Example 1. This test followed the procedure of "JIS Z 2801 Antimicrobial processed products - Antimicrobial test methods and antimicrobial effects" (2012).

[0082] • Calculation of antibacterial activity value The antibacterial activity value was calculated according to the following formula 3. A higher antibacterial activity value indicates a stronger antibacterial effect.

[0083]

number

[0084] • Evaluation of antibacterial activity when compound combinations are used. The antibacterial effect of the combined use of the compounds was evaluated according to Formula 2, similar to Test Example 1. If Formula 2 is satisfied, it means that a synergistic antibacterial effect is obtained by combining the compounds.

[0085] 2.Results The results are shown in Table 2.

[0086] [Table 2]

[0087] In Table 2, the values ​​shown in the "Evaluation Results" column are the antibacterial activity values ​​calculated as described above. The evaluation result when using the sample from Comparative Example 7 (trans-2-methyl-2-pentenal alone) was 0.28, and the evaluation result when using the sample from Comparative Example 8 (2-methylbutanal alone) was 0.12. In contrast, the evaluation result when using the sample from Example 6 (trans-2-methyl-2-pentenal and 2-methylbutanal in combination) was 3.41. Applying the evaluation results to Equation 2, we get [3.41] - [0.4(0.28 + 0.12)] = 3.01 ≥ 1. From this, it was confirmed that a synergistic antibacterial effect against bacteria was obtained in Example 6, which used trans-2-methyl-2-pentenal and 2-methylbutanal in combination.

[0088] Furthermore, the evaluation result when using the sample from Example 7 (trans-2-methyl-2-pentenal and 3-methylpentanol in combination) was 3.19. The evaluation result when using the sample from Comparative Example 7 (trans-2-methyl-2-pentenal alone) was 0.28, and the evaluation result when using the sample from Comparative Example 9 (3-methylpentanol alone) was 0.02. Applying each value to Equation 2, we get [3.19] - [0.3(0.28 + 0.02)] = 2.89 ≥ 1. In Example 7 as well, it was confirmed that a synergistic antibacterial effect against bacteria can be obtained by using the above compounds in combination.

[0089] Furthermore, the evaluation result in Example 8 was 3.45, the evaluation result in Comparative Example 7 was 0.28, and the evaluation result in Comparative Example 10 was 0.03. Applying each value to Equation 2, we got [3.45]-[0.31(0.28+0.03)]=3.14≧1. Applying the evaluation result in Example 9 (2.13), Comparative Example 8 (0.12), and Comparative Example 10 (0.03) to Equation 2, we got [2.13]-[0.15(0.12+0.03)]=1.98≧1. Applying the evaluation result in Example 10 (1.75), Comparative Example 11 (0.12), and Comparative Example 12 (0.03) to Equation 2, we got [1.75]-[0.15(0.12+0.03)]=1.6≧1. These findings confirm that a synergistic antibacterial effect against bacteria can be obtained by using the compounds in combination with the samples in Examples 8-10.

[0090] This confirms that the antibacterial effect against bacteria can be synergistically enhanced by using the aforementioned compounds in combination. In particular, in Examples 6 to 10, the calculated value in Formula 2 was 1 or higher, indicating a good synergistic effect in terms of antibacterial activity against bacteria. Furthermore, in Examples 6 to 8, the calculated value was 2 or higher, indicating an even better synergistic effect in terms of antibacterial activity against bacteria, and in Examples 6 and 8, the calculated value was 3 or higher, indicating a remarkably excellent synergistic effect.

[0091] Furthermore, in Test Example 2, the antibacterial effect was evaluated using the plate after the compound and the urethane plate were placed together in a non-contact manner, and a synergistically enhanced antibacterial effect was observed. Therefore, it was understood that even when an antibacterial agent containing two or more of the above compounds is volatilized and used on objects such as hard surfaces like urethane plates, spaces, or food, a synergistically enhanced antibacterial effect can be imparted to the target.

Claims

1. An antimicrobial agent containing at least two compounds selected from the group consisting of trans-2-methyl-2-pentenal, 2-methylbutanal, trans-2-hexenal, propylaldehyde, 3-methylpentanol, and 2,5-dimethylfuran.

2. The antibacterial agent according to claim 1, which is an antibacterial agent for spaces, an antibacterial agent for articles, an antibacterial agent for external use, or an antibacterial agent for food.

Images