Malodor suppressant

Abstract

To provide a malodor suppressant and a malodor suppression method that utilize an olfactory mechanism involving olfactory receptors in which metals play a role in odor perception.SOLUTION: Provided is an odor suppressant targeting malodors derived from substances that activate olfactory receptors involved in odor perception in which copper plays a role, where the odor suppressant comprises at least one selected from the group consisting of N-(3,7-dimethyl-7-hydroxyoctylidene) methyl anthranilate, 2-[(2-methylundecan-1-ylidene)amino] methyl benzoate, and 2-methyl-2-pentenoic acid as an active ingredient.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to malodor control agents. [Background technology]

[0002] In our living environment, there are many malodorous molecules with different polarities and molecular weights. To eliminate the various malodorous molecules, various deodorizing methods have been developed. In general, deodorizing methods are broadly divided into biological methods, chemical methods, physical methods, and sensory methods. Among malodorous molecules, short-chain fatty acids and amines with high polarity can be deodorized by chemical methods, i.e., neutralization reactions. In addition, sulfur compounds such as thiols can be deodorized by physical methods, i.e., adsorption treatments.

[0003] These conventional methods either adsorb and decompose the target malodorous molecules to reduce their presence, or use air fresheners to eliminate the odor. However, the method of adsorbing and decomposing malodorous molecules lacks immediate effect because it takes time to reduce the malodorous molecules. On the other hand, when air fresheners are used, there are problems such as the unpleasant smell of the air freshener itself and the fact that it also removes smells other than the target malodorous molecules.

[0004] In mammals such as humans, odors are recognized when odor molecules that enter the nasal cavity dissolve in the olfactory mucus that covers the olfactory epithelium and bind to olfactory receptors on olfactory nerve cells in the olfactory epithelium, and the receptor response is transmitted to the central nervous system. In general, olfactory receptors and odor molecules correspond in a multiple-to-multiple combination. That is, each olfactory receptor receives multiple odor molecules with similar structures with different affinities, while each odor molecule is received by multiple types of olfactory receptors. Furthermore, it has been reported that an odor molecule that activates a certain olfactory receptor acts as an antagonist that inhibits the activation of another olfactory receptor. The combination of responses of these multiple types of olfactory receptors results in the recognition of each odor.

[0005] Therefore, even if the same odor molecule is present, if other odor molecules are present at the same time, the receptor response may be inhibited by the other odor molecules, and the odor finally recognized may be completely different. This mechanism is called olfactory receptor antagonism. Unlike deodorizing methods that add other odors such as perfumes and fragrances, this odor modulation by receptor antagonism can specifically eliminate the recognition of bad odors and does not cause discomfort due to the odor of the fragrance. However, since odor suppression based on olfactory receptor antagonism inhibits the response of a specific olfactory receptor, there is a demand for a more versatile odor suppression technology that is highly selective for the odor molecules to be suppressed.

[0006] On the other hand, it has been suggested that biological trace metals such as copper are present in olfactory mucus and affect odor perception. For example, Non-Patent Document 1 describes a mechanism in which thiol and copper bind to form a complex, and the complex binds to an olfactory receptor, resulting in the perception of a thiol odor. Non-Patent Document 2 describes that copper amplifies the olfactory receptor response of thiol by about 1000 times. In addition, OR2T11, OR4S2, OR2M3, OR2W1, OR2T1, OR4E2, etc. are known as olfactory receptors in which copper is involved in the mechanism of odor perception (Patent Documents 1 to 3, Non-Patent Document 2). Furthermore, based on the finding that specific modifications to olfactory receptors can improve responsiveness while maintaining the ligand selectivity of the original olfactory receptor, it has been found that, using modified olfactory receptor polypeptides OR2T29, OR4K17, OR2T27, OR2T5, OR2T4, OR11H2, OR6B3, OR12D3, OR6B1, OR4C15, and OR2L13, these modified olfactory receptor polypeptides are olfactory receptors in which copper is involved in the mechanism of odor perception, and further that the original OR2T29, OR4K17, OR2T27, OR2T5, OR2T4, OR11H2, OR6B3, OR12D3, OR6B1, OR4C15, and OR2L13 are olfactory receptors in which copper is involved in the mechanism of odor perception (Patent Document 4).

[0007] Therefore, it is considered that the intensity of odor perception can be reduced by capturing metals in olfactory mucus, and Non-Patent Document 1 reports that administration of a copper chelating agent to the nasal cavity of mice reduces sensitivity to thiols. However, there are various problems with administering a chelating agent to the nasal cavity of mammals such as humans. In general, chelating agents are non-volatile, and in order to administer them into the nasal cavity, they must be inhaled using a sprayer or the like. Places where bad odors occur include a wide variety of places, such as living spaces such as toilets and kitchen drains, public spaces such as garbage collection areas and smoking areas, and business establishments such as livestock facilities and waste incineration facilities, and the bad odors may spread over a wide area. In such a variety of spaces and situations, administering a chelating agent into the nasal cavity to suppress bad odors is not a simple method. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] JP 2020-10629 A [Patent Document 2] Special Publication No. 2020-513564 [Patent Document 3] JP 2020-112520 A [Patent Document 4] JP 2023-84477 A [Non-patent literature]

[0009] [Non-Patent Document 1] Xufang Duan et al. Proc Natl Acad Sci US A. 2012 Feb 28;109(9):3492-7 [Non-Patent Document 2] Shengju Li et.al. Journal of the American Chemical Society. 2016, 138, 40, 13281-13288 Summary of the Invention [Problem to be solved by the invention]

[0010] The present invention relates to providing a malodor suppressant and a malodor suppression method that utilize the olfactory mechanism via olfactory receptors in which metals are involved in odor perception. [Means for solving the problem]

[0011] The inventors searched for fragrances that bind to metals from among fragrances that have a history of use by humans and have a pleasant odor, and found that methyl N-(3,7-dimethyl-7-hydroxyoctylidene)anthranilate, methyl 2-[(2-methylundecane-1-ylidene)amino]benzoate, and 2-methyl-2-pentenoic acid have the ability to bind to copper, and that these fragrances have an odor-suppressing effect.

[0012] That is, the present invention relates to the following 1) and 2). 1) An agent for suppressing malodor caused by substances that activate olfactory receptors in which copper is involved in odor perception, comprising at least one active ingredient selected from the group consisting of methyl N-(3,7-dimethyl-7-hydroxyoctylidene)anthranilate, methyl 2-[(2-methylundecane-1-ylidene)amino]benzoate, and 2-methyl-2-pentenoic acid. 2) A method for suppressing malodor caused by a substance that activates an olfactory receptor in which copper is involved in odor perception, the method comprising applying to a subject in need thereof at least one selected from the group consisting of methyl N-(3,7-dimethyl-7-hydroxyoctylidene)anthranilate, methyl 2-[(2-methylundecane-1-ylidene)amino]benzoate, and 2-methyl-2-pentenoic acid. Effect of the Invention

[0013] The malodor suppressant provided by the present invention can safely suppress malodors caused by various substances that activate the olfactory receptors by suppressing the response of the olfactory receptors in which metals are involved in odor perception. The malodor suppressant of the present invention uses a volatile fragrance as an active ingredient, and can be easily applied to various spaces and a wide range of areas, allowing for simple malodor suppression. [Brief description of the drawings]

[0014] [Figure 1] OR4S2 activity towards dimethyl disulfide with or without added copper. [Diagram 2] OR2M3 activity towards 3-mercapto-2-methyl-1-pentanol with or without added copper. [Diagram 3] Changes in the 1H-NMR chemical shift values ​​of methyl N-(3,7-dimethyl-7-hydroxyoctylidene)anthranilate. [Figure 4] Change in 1H-NMR chemical shift value of methyl 2-[(2-methylundecane-1-ylidene)amino]benzoate. [Diagram 5] Change in the chemical shift value of 1H-NMR of 2-methyl-2-pentenoic acid. [Figure 6] Furfuryl methyl sulfide odor suppression effect of test substances (Mean ± SE, n = 2-5). [Figure 7] Dimethyl disulfide odor suppression effect of test substances (Mean ± SE, n = 2-4). [Figure 8] Dimethyl trisulfide odor suppression effect of test substances (Mean ± SE, n = 2-4). [Figure 9] 3-Mercapto-2-methyl-1-pentanol odor-inhibiting effect of test substances (Mean±SE, n=2-5). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] In this specification, the term "olfactory receptor polypeptide" refers to an olfactory receptor or a polypeptide having a function equivalent thereto. A polypeptide having a function equivalent to an olfactory receptor refers to a polypeptide that can be expressed on a cell membrane like an olfactory receptor, is activated by binding with an odorant molecule, and when activated, has the function of increasing the amount of intracellular cAMP by coupling with Gαs in the cell to activate adenylate cyclase (Nat.Neurosci., 2004, 5:263-278). An example of an olfactory receptor polypeptide having a function equivalent to a certain olfactory receptor is an olfactory receptor polypeptide that has an amino acid sequence that is at least 80% identical to the amino acid sequence of the certain olfactory receptor and is responsive to an odorant molecule to which the certain olfactory receptor is responsive. Another example of an olfactory receptor polypeptide having a function equivalent to a certain olfactory receptor is a receptor derived from an animal species that is homologous to the certain olfactory receptor and different from the animal from which the certain olfactory receptor is derived.

[0016] In the present specification, the identity of a nucleotide sequence or an amino acid sequence is calculated by the Lipman-Pearson method (Science, 1985, 227:1435-41). Specifically, the identity is calculated by performing an analysis using the search homology program of the genetic information processing software Genetyx-Win (Ver. 5.1.1; software development) with the unit size to compare (ktup) set to 2.

[0017] As used herein, "at least 80% identity" with respect to a nucleotide sequence or amino acid sequence means identity of 80% or more, preferably 85% or more, more preferably 90% or more, even more preferably 95% or more, even more preferably 98% or more, and still more preferably 99% or more.

[0018] In this specification, "odor suppression utilizing the olfactory mechanism via olfactory receptors in which a metal is involved in odor perception" refers to a means of applying a target odor molecule that activates an olfactory receptor in which a metal is involved in odor perception together with another odor molecule that binds to the metal, so that the other odor molecule captures the metal in the olfactory mucus and inhibits the response of the olfactory receptor in which a metal is involved in odor perception to the target odor molecule, thereby suppressing odors (including bad odors) recognized by an individual.

[0019] In the present specification, the term "olfactory receptor in which a metal is involved in odor perception" refers to an olfactory receptor polypeptide in which a metal is involved in the process of receiving an odor molecule, and includes an olfactory receptor polypeptide to which an odor molecule and a metal complex are bound, and an olfactory receptor polypeptide to which an odor molecule is further bound after binding to a metal to form a complex. Here, examples of metals include transition metals such as copper, zinc, and nickel, and preferably copper. Examples of olfactory receptors in which a metal is involved in odor perception are not particularly limited, but olfactory receptors in which copper is involved in odor perception are preferred. Examples of olfactory receptors in which copper is involved in odor perception include OR2T11, OR4S2, OR2M3, OR2W1, OR2T1, and OR4E2 (Patent Documents 1 to 3, Non-Patent Document 2). In addition, based on the finding that specific modifications to olfactory receptors can improve responsiveness while maintaining the ligand selectivity of the original olfactory receptor, it has been found that modified olfactory receptor polypeptides (consensus olfactory receptors) of OR2T29, OR4K17, OR2T27, OR2T5, OR2T4, OR11H2, OR6B3, OR12D3, OR6B1, OR4C15, and OR2L13 are olfactory receptors in which copper is involved in odor perception, and further that the original OR2T29, OR4K17, OR2T27, OR2T5, OR2T4, OR11H2, OR6B3, OR12D3, OR6B1, OR4C15, and OR2L13 are olfactory receptors in which copper is involved in odor perception (Patent Document 4). Specific examples of olfactory receptors in which copper is involved in odor perception include the above-mentioned olfactory receptors and olfactory receptor polypeptides having equivalent functions thereto.

[0020] The olfactory receptor OR2T11 is an olfactory receptor expressed in human olfactory cells, and is registered in GenBank under Accession No. NP_001001964.1. OR2T11 is a polypeptide consisting of the amino acid sequence of SEQ ID NO: 1. As disclosed in Patent Document 1 and Non-Patent Document 2, OR2T11 is an olfactory receptor in which copper has been reported to be involved in odor perception. OR2T11 is known to be a receptor for sulfur compounds such as methyl mercaptan, ethanethiol, 1-propanethiol, 2-propanethiol, allyl mercaptan, 1-butanethiol, 2-butanethiol, 2-methyl-1-propanethiol, 2-methyl-2-propanethiol, 2-pentanethiol, 3-methyl-2-butanethiol, cyclopentanethiol, methanedithiol, (methylthio)methanethiol, 1-(methylthio)ethanethiol, 2,3,5-trithiahexane, bis(methylthiomethyl)disulfide, thiolane-2-thiol, (ethylthio)methanethiol, thietane, dimethyl disulfide, and dimethyl trisulfide (Patent Documents 1 and 4, Non-Patent Document 2).

[0021] The olfactory receptor OR4S2 is an olfactory receptor expressed in human olfactory cells and is registered in GenBank under Accession No. NP_001004059.2. OR4S2 is a polypeptide consisting of the amino acid sequence of SEQ ID NO: 2. As disclosed in Patent Document 1, OR4S2 is an olfactory receptor in which copper has been reported to be involved in odor perception. OR4S2 is known to be a receptor for sulfur compounds such as methyl mercaptan, dimethyl sulfide, furfuryl methyl sulfide, dimethyl disulfide, and dimethyl trisulfide (Patent Document 1, JP 2020-510436 A, Chiori Ijichi et al. Chemical Senses. 2019, 44: 465-481).

[0022] The olfactory receptor OR2M3 is an olfactory receptor expressed in human olfactory cells, and is registered in GenBank under Accession No. NP_001004689.1. OR2M3 is a polypeptide consisting of the amino acid sequence of SEQ ID NO: 3. As disclosed in Patent Document 3, OR2M3 is an olfactory receptor in which copper is suggested to be involved in odor perception. OR2M3 is known to be a receptor for sulfur compounds such as 3-mercapto-2-methyl-1-pentanol, 3-mercapto-3-methylbutylformate, and 3-mercapto-3-methyl-1-butanol (Patent Document 3, Franziska Noe et al. Chemical Senses. 2017, 42: 195-210).

[0023] The olfactory receptors OR2W1, OR2T1 and OR4E2 are also olfactory receptors expressed in human olfactory cells, and their GenBank Accession Nos. and amino acid sequence numbers, as well as examples of activating odor molecules, are summarized in Table 1 below (Patent Documents 1 to 3 and JP 2022-187352 A).

[0024] [Table 1]

[0025] The olfactory receptors OR2T29, OR4K17, OR2T27, OR2T5, OR2T4, OR11H2, OR6B3, OR12D3, OR6B1, OR4C15 and OR2L13 are also olfactory receptors expressed in human olfactory cells, and their GenBank Accession Nos. and amino acid sequence ID numbers, the amino acid sequence ID numbers of their modified olfactory receptor polypeptides (consensus olfactory receptors) in Patent Document 4, and examples of activating odor molecules are summarized in Table 2 below (Patent Document 4).

[0026] [Table 2]

[0027] As shown in the Examples below, the present inventors have found that methyl N-(3,7-dimethyl-7-hydroxyoctylidene)anthranilate (CAS Registry Number: 89-43-0); methyl 2-[(2-methylundecane-1-ylidene)amino]benzoate (CAS Registry Number: 67800-80-0); and 2-methyl-2-pentenoic acid (CAS Registry Number: 3142-72-1) have the ability to bind to copper and actually have a malodor suppressing effect. The above compounds bind to copper and suppress the response of olfactory receptors in which copper is involved in odor perception, in other words, suppress the activation of the olfactory receptors by malodorous molecules, thereby causing a change in an individual's recognition of malodors and, as a result, suppressing the malodor.

[0028] Therefore, in one aspect, the present invention provides an agent for suppressing malodor caused by a substance that activates an olfactory receptor in which copper is involved in odor perception, the agent comprising at least one active ingredient selected from the group consisting of methyl N-(3,7-dimethyl-7-hydroxyoctylidene)anthranilate, methyl 2-[(2-methylundecane-1-ylidene)amino]benzoate, and 2-methyl-2-pentenoic acid.

[0029] Methyl N-(3,7-dimethyl-7-hydroxyoctylidene)anthranilate, methyl 2-[(2-methylundecane-1-ylidene)amino]benzoate and 2-methyl-2-pentenoic acid (hereinafter also referred to as the compounds of the present invention) have been known as fragrance materials, but they were not known to have the ability to bind to copper or to have the function of suppressing malodors. These compounds of the present invention have the function of suppressing malodors, but can also exhibit their own scent as fragrance materials, so they can be used as malodor suppressors and as fragrances at the same time.

[0030] Among the compounds of the present invention, methyl N-(3,7-dimethyl-7-hydroxyoctylidene)anthranilate can be purchased commercially and can be obtained from Sigma-Aldrich, etc. 2-Methyl-2-pentenoic acid can be purchased commercially and can be obtained from Tokyo Chemical Industry Co., Ltd., etc. Alternatively, these can be produced by chemical synthesis to produce the same substance as the commercially available product or a composition containing the same. In addition, methyl 2-[(2-methylundecane-1-ylidene)amino]benzoate can be chemically synthesized by a known method, for example, in the method of producing a Schiff base from methyl anthranilate and an aldehyde described in Gloria Nicastro et al. International Journal of Molecular Sciences, 2022, 23(6):3105, it can be obtained by using 2-methylundecanal as the aldehyde.

[0031] The "bad odor" suppressed by the present invention is a bad odor caused by a substance that activates an olfactory receptor in which copper is involved in odor perception. Whether or not a certain substance activates an olfactory receptor in which copper is involved in odor perception can be determined by adding the substance to the olfactory receptor and then measuring the response of the olfactory receptor. The measurement may be performed by any method known in the art as a method for measuring the response of an olfactory receptor, such as measuring the amount of intracellular cAMP. For example, it is known that when an olfactory receptor is activated by an odor molecule, it couples with a G protein α subunit classified as the Gαs family in the cell to activate adenylate cyclase, thereby increasing the amount of intracellular cAMP (Nat.Neurosci., 2004, 5:263-278). On the other hand, when an olfactory receptor is activated by an odor molecule, it also couples with a protein belonging to the Gq family, such as Gα15, in the cell, and can increase the amount of calcium ions in the cell. Therefore, the response of the olfactory receptor can be measured by using the amount of intracellular cAMP or calcium ion after the addition of an odor molecule, or the behavior of downstream molecules activated through them as an index. Methods for measuring the amount of cAMP include ELISA, reporter gene assays, and methods using cAMP-responsive reporter proteins. In a method using a cAMP-responsive reporter protein, for example, a firefly luciferase genetically modified to contain a portion of a cAMP-binding protein is used, and the amount of cAMP is measured by monitoring the luminescence value of the luciferase corresponding to the amount of cAMP (GloSensor (trademark) cAMP Assay (Promega)). Other methods for measuring the response of the olfactory receptor include calcium imaging and TGFα shedding assays, which are methods for measuring calcium ion concentration. In addition, as an example of a method using the behavior of downstream molecules activated through the amount of cAMP as an index, a two-electrode voltage clamp method is also effective in measuring the potential change inside and outside the cell membrane via the cystic fibrosis transmembrane conductance regulator CFTR, which is activated by a cAMP signal, in Xenopus oocytes.

[0032] The substance that activates the olfactory receptor in which copper is involved in odor perception is preferably a sulfur compound, more preferably at least one selected from the group consisting of a thiol compound and a sulfide compound, and even more preferably at least one selected from the group consisting of furfuryl methyl sulfide, dimethyl disulfide, dimethyl trisulfide, and 3-mercapto-2-methyl-1-pentanol.

[0033] In the present invention, the "odor of furfuryl methyl sulfide (furfuryl methyl sulfide odor)", "odor of dimethyl disulfide (dimethyl disulfide odor)", "odor of dimethyl trisulfide (dimethyl trisulfide odor)", and "odor of 3-mercapto-2-methyl-1-pentanol (3-mercapto-2-methyl-1-pentanol odor)" may be odors caused by furfuryl methyl sulfide, dimethyl disulfide, dimethyl trisulfide, and 3-mercapto-2-methyl-1-pentanol, respectively. The "furfuryl methyl sulfide odor", "dimethyl disulfide odor", "dimethyl trisulfide odor", and "3-mercapto-2-methyl-1-pentanol odor" in the present invention can be typically expressed as a garlic or onion-like odor.

[0034] In the present invention, the combination of the active ingredient and the substance causing the malodor to be suppressed is not limited to these, but a combination of at least one selected from the group consisting of methyl N-(3,7-dimethyl-7-hydroxyoctylidene)anthranilate, methyl 2-[(2-methylundecane-1-ylidene)amino]benzoate, and 2-methyl-2-pentenoic acid and a sulfur compound is preferred, a combination of at least one selected from the group consisting of methyl N-(3,7-dimethyl-7-hydroxyoctylidene)anthranilate, methyl 2-[(2-methylundecane-1-ylidene)amino]benzoate, and 2-methyl-2-pentenoic acid and at least one selected from the group consisting of thiol compounds and sulfide compounds is more preferred, and a combination of at least one selected from the group consisting of methyl N-(3,7-dimethyl-7-hydroxyoctylidene)anthranilate, methyl 2-[(2-methylundecane-1-ylidene)amino]benzoate, and 2-methyl-2-pentenoic acid and at least one selected from the group consisting of methyl N-(3,7-dimethyl-7-hydroxyoctylidene)anthranilate, methyl 2-[(2-methylundecane-1-ylidene)amino]benzoate, and 2-methyl-2-pentenoic acid is more preferred. More preferred are combinations of methyl N-(3,7-dimethyl-7-hydroxyoctylidene)anthranilate and at least one selected from the group consisting of furfuryl methyl sulfide, dimethyl disulfide, dimethyl trisulfide, and 3-mercapto-2-methyl-1-pentanol, combinations of methyl 2-[(2-methylundecane-1-ylidene)amino]benzoate and at least one selected from the group consisting of furfuryl methyl sulfide, dimethyl disulfide, dimethyl trisulfide, and 3-mercapto-2-methyl-1-pentanol, and combinations of 2-methyl-2-pentenoic acid and at least one selected from the group consisting of dimethyl disulfide, dimethyl trisulfide, and 3-mercapto-2-methyl-1-pentanol.

[0035] In the present invention, combinations of malodor-causing substances and olfactory receptors in which copper is involved in odor perception that are activated by the substances (responding to the malodor-causing substances) include, but are not limited to, combinations of furfuryl methyl sulfide and OR4S2, combinations of dimethyl disulfide and OR4S2 or OR2T11, combinations of dimethyl trisulfide and OR4S2 or OR2T11, and combinations of 3-mercapto-2-methyl-1-pentanol and OR2M3.

[0036] The malodor suppressant of the present invention contains at least one compound selected from the group consisting of the compounds of the present invention as an active ingredient. For example, the active ingredient of the malodor suppressant of the present invention can be at least one selected from the group consisting of the compounds of the present invention, for example, any one alone or any combination of two or more. In one embodiment, the malodor suppressant of the present invention can essentially consist of at least one selected from the group consisting of the compounds of the present invention. In another embodiment, the malodor suppressant of the present invention is a composition for suppressing malodor, containing at least one selected from the group consisting of the compounds of the present invention as an active ingredient and further containing other ingredients.

[0037] In another aspect of the present invention, at least one selected from the group consisting of the compounds of the present invention can be used as an active ingredient for suppressing malodor.In one embodiment, at least one selected from the group consisting of the compounds of the present invention can be contained in a compound or composition for suppressing malodor as an active ingredient for suppressing malodor.Alternatively, at least one selected from the group consisting of the compounds of the present invention can be used for the manufacture of a malodor inhibitor or for the manufacture of a compound or composition for suppressing malodor.

[0038] The malodor suppressant of the present invention and the composition for suppressing malodor described above may contain at least one selected from the group consisting of the compounds of the present invention, as well as other components having deodorizing effect, or any components used in deodorants or deodorants, depending on the purpose. Any known deodorants can be used as the other components having deodorizing effect, and examples thereof include deodorizing active ingredients extracted from each part of a plant, such as leaves, petioles, fruits, stems, roots, and bark (e.g., green tea extract); organic acids such as lactic acid, gluconic acid, succinic acid, glutaric acid, adipic acid, malic acid, tartaric acid, maleic acid, fumaric acid, itaconic acid, citric acid, benzoic acid, and salicylic acid, various amino acids and their salts, glyoxal, oxidizing agents, flavonoids, catechins, and polyphenols; porous substances such as activated carbon and zeolite; inclusion agents such as cyclodextrins; photocatalysts; and various masking agents.

[0039] Examples of optional components used in the deodorants and deodorants include fragrances, powdered components, liquid oils and fats, solid oils and fats, waxes, hydrocarbons, plant extracts, herbal ingredients, higher alcohols, lower alcohols, esters, long-chain fatty acids, surfactants (nonionic surfactants, anionic surfactants, cationic surfactants, amphoteric surfactants, etc.), sterols, polyhydric alcohols, moisturizers, water-soluble polymer compounds, thickeners, film-forming agents, bactericides, preservatives, UV absorbers, retention agents, cooling agents, warming agents, stimulants, sequestering agents, sugars, amino acids, organic amines, synthetic resin emulsions, pH adjusters, antioxidants, antioxidant assistants, oils, powders, capsules, chelating agents, inorganic salts, organic salt pigments, thickeners, bactericides, preservatives, antifungal agents, colorants, antifoaming agents, extenders, modulators, organic acids, polymers, polymer dispersants, enzymes, enzyme stabilizers, and the like.

[0040] In one embodiment, at least one selected from the group consisting of the compounds of the present invention can be used as an active ingredient for suppressing malodor for any compound or composition for which suppression of malodor is desired, or for any environment for which suppression of malodor is desired, or for any item contained in the environment. Alternatively, at least one selected from the group consisting of the compounds of the present invention can be used as an active ingredient for suppressing malodor for the manufacture of a compound or composition for which suppression of malodor is desired.

[0041] In a further aspect, the present invention provides a method for suppressing malodor caused by a substance that activates an olfactory receptor in which copper is involved in odor perception, comprising a step of coexisting malodor with at least one compound selected from the group consisting of the compounds of the present invention. In the method of the present invention, the olfactory receptor in which copper is involved in odor perception and the malodor to be suppressed are the same as those of the malodor suppressant described above.

[0042] In one embodiment of the method of the present invention, in the presence of malodor, at least one compound selected from the group consisting of the compounds of the present invention is applied to a subject, so that the malodor and the compound coexist.Therefore, the copper in the olfactory mucus of the subject is bound to the compound, and the activation of the olfactory receptors of the subject, which are related to copper in the odor perception, by the causative substance of the malodor is suppressed, so that the malodor is suppressed based on the odor suppression utilizing the olfactory mechanism by the olfactory receptors, which are related to metal in the odor perception.

[0043] In the method of the present invention, examples of the subject include a subject in need of suppression of malodor, preferably a subject in need of suppression of malodor based on odor suppression utilizing the olfactory mechanism by olfactory receptors in which metals are involved in odor perception. The subject is not particularly limited as long as it is a mammal, but is preferably a human.

[0044] In another embodiment of the method of the present invention, at least one selected from the group consisting of the compounds of the present invention is applied in advance to an environment where a malodor may occur.Therefore, when a malodor occurs in the environment, the compound of the present invention is applied to the subject in the presence of the malodor, so that the malodor is suppressed based on the odor suppression utilizing the olfactory mechanism by the olfactory receptor in which metals are involved in odor perception.

[0045] In another embodiment of the method of the present invention, at least one selected from the group consisting of the compounds of the present invention is applied to a compound or composition that contains or may contain a malodor-causing substance that activates an olfactory receptor in which copper is involved in odor perception.Therefore, at least one selected from the group consisting of the compounds of the present invention suppresses the activation of the olfactory receptor in which copper is involved in odor perception by the malodor-causing substance contained in the compound or composition, suppresses the recognition of malodor in the subject, and as a result, suppresses malodor.Examples of the application of the compound of the present invention in this embodiment include spraying the compound of the present invention on the compound or composition, and providing the compound or composition that already contains the compound of the present invention.

[0046] The odor suppression of the present invention using the olfactory mechanism of an olfactory receptor in which metals are involved in odor perception is different from a means (odor suppression by olfactory receptor antagonism) in which an antagonist that binds to a specific olfactory receptor but does not activate the receptor is used to inhibit the receptor response to a target odor molecule, thereby suppressing the odor recognized by an individual, even if the means also use other odor molecules. In odor suppression by olfactory receptor antagonism, the odor molecules to be suppressed are limited because the response of a specific olfactory receptor is inhibited, but in odor suppression using the olfactory mechanism of an olfactory receptor in which metals are involved in odor perception, the odor molecules to be suppressed are not particularly limited as long as they are molecules that activate an olfactory receptor in which metals are involved in odor perception, making it a more versatile odor suppression means. EXAMPLES

[0047] The present invention will be described in more detail below based on examples, but the present invention is not limited to these examples.

[0048] Reference Example 1: Preparation and analysis of cells expressing human olfactory receptors The olfactory receptor activity of human olfactory receptors OR4S2 and OR2M3 was measured under copper-added and copper-free conditions.

[0049] 1) Creation of olfactory receptor genes Based on the sequence information registered in GenBank, the genes encoding the human olfactory receptors OR4S2 and OR2M3 were cloned. Each gene was cloned by PCR using human genomic DNA female (G1521: Promega) as a template. Each gene amplified by PCR was inserted into the pENTR vector (Invitrogen) according to the manual, and recombined into the NotI and AscI sites created downstream of the Flag-Rho tag sequence on the pME18S vector using the NotI and AscI sites present on the pENTR vector.

[0050] 2) Construction of pME18S-human RTP1S vector The gene encoding human RTP1S was inserted into the EcoRI and XhoI sites of the pME18S vector.

[0051] 3) Creation of olfactory receptor expressing cells For the luciferase assay, a reaction solution with the composition shown in Table 3 was prepared and left to stand in a clean bench for 20 minutes, and then added to each well of a 96-well plate (BD). Next, 3 × 10 HEK293 cells suspended in DMEM (Nacalai) were added to each well of a 96-well plate (BD). 5 The solution was adjusted to a concentration of 100 cells / mL, 100 μL of which was added to each well and cultured for 24 hours in an incubator maintained at 37°C and 5% CO2. As a control, cells that do not express olfactory receptors (mock) were prepared.

[0052] [Table 3]

[0053] 4) Luciferase assay The medium was removed from the culture prepared in 3) above, and 75 μL of the odor solution of the specified concentration prepared in new medium was added. The cells were cultured in a CO2 incubator for 4 hours to allow the luciferase gene to be fully expressed in the cells. Luciferase activity was measured using Dual-Glo TM The measurement was performed using a luciferase assay system (Promega) according to the product's operating manual. In each well of the 96-well plate, the luminescence value derived from firefly luciferase induced by stimulation with the test substance was divided by the luminescence value derived from Renilla luciferase to calculate fluc / hRluc. The value of the fluc / hRluc induced by odorant stimulation divided by the fluc / hRluc in cells not stimulated with the odorant was calculated as a fold increase, which was used as an index of response strength.

[0054] 5) Odor substances The following odorants were used: Dimethyl disulfide (Tokyo Chemical Industry Co., Ltd.) 3-Mercapto-2-methyl-1-pentanol (Tokyo Chemical Industry Co., Ltd.) Dimethyl disulfide is known to activate OR4S2, and 3-mercapto-2-methyl-1-pentanol is known to activate OR2M3. OR4S2-expressing cells were stimulated with the dimethyl disulfide solution prepared as described above, and OR2M3-expressing cells were stimulated with the 3-mercapto-2-methyl-1-pentanol solution in the same manner.

[0055] 6) Results The olfactory receptor activity of OR4S2 under copper-added or -free conditions is shown in Figure 1, and the olfactory receptor activity of OR2M3 under copper-added or -free conditions is shown in Figure 2. OR4S2 and OR2M3 activities were enhanced under copper-added conditions.

[0056] Example 1 Screening of fragrances that interact with copper When the sample and metal bond 1The interaction between fragrance and copper was evaluated by utilizing the phenomenon of change in the chemical shift (δ) value of H-NMR. When a fragrance binds to copper, the Larmor frequency changes with the change in the chemical bond state of the fragrance, and a change in the chemical shift value is observed. Therefore, the change in the chemical shift value of a sample in which a copper solution was added to the fragrance was confirmed.

[0057] 1) Sample preparation method and 1 H-NMR measurement conditions A copper solution was prepared by dissolving copper(II) chloride (FUJIFILM Wako Pure Chemicals) in DO (Kanto Chemical Co., Ltd.) to a final concentration of 1 mM. A 100 mM DMSO-d6 (Sigma-Aldrich) solution was prepared for each fragrance, and then diluted with DO or 1 mM copper solution to a final concentration of 1 mM. The sample was poured into a 5 mm diameter glass sample tube to a depth of approximately 4 cm from the bottom. 1 H-NMR measurement was performed. 1 The H-NMR measurement conditions are shown in Table 4. The spectra obtained from the DO sample and the copper solution sample were compared.

[0058] [Table 4]

[0059] 2) Results 1 The results of H-NMR measurements are shown in Figures 3 to 5. Three types of fragrances were found that showed changes in the NMR spectrum (Figure 3: methyl N-(3,7-dimethyl-7-hydroxyoctylidene)anthranilate, Figure 4: methyl 2-[(2-methylundecane-1-ylidene)amino]benzoate, Figure 5: 2-methyl-2-pentenoic acid).

[0060] Example 2: Odor suppression effect of fragrances interacting with copper 1) Odor molecules Fragrance (test substance) Methyl N-(3,7-dimethyl-7-hydroxyoctylidene)anthranilate (Sigma-Aldrich) ·Methyl 2-[(2-methylundecane-1-ylidene)amino]benzoate (contract manufacturing) 2-Methyl-2-pentenoic acid (Tokyo Chemical Industry Co., Ltd.) Odor-causing substances Furfuryl methyl sulfide (ACROS ORGANICS) Dimethyl disulfide (Tokyo Chemical Industry Co., Ltd.) Dimethyl trisulfide (Tokyo Chemical Industry Co., Ltd.) 3-Mercapto-2-methyl-1-pentanol (Tokyo Chemical Industry Co., Ltd.) It is known that furfuryl methyl sulfide activates OR4S2, dimethyl disulfide and dimethyl trisulfide activate OR2T11 and OR4S2, and 3-mercapto-2-methyl-1-pentanol activates OR2M3, which are olfactory receptors in which copper is involved in odor perception.

[0061] 2) Evaluation of odor suppression effect by test substances The inhibitory effect of the test substances against malodor was evaluated. Each test substance and malodor-causing substance was diluted to the concentration shown in Table 5 using mineral oil (Sigma-Aldrich). 30 μL of one of the diluted solutions was soaked into a cotton ball (Silky cotton ball No. 10, White Cross) and placed in a 50 mL vial (No. 7, Maruemu). A vial containing a cotton ball containing the test substance solution and a cotton ball containing a malodor solution (test sample), a vial containing a cotton ball containing only the test substance solution (fragrance sample), and a vial containing a cotton ball containing only the malodor solution (control sample) were prepared. The vials containing the cotton balls were left to stand in a thermostatic bath at 37°C for 1 hour before being used for evaluation. In the evaluation, the nose was brought close to the mouth of the bottle to smell the odor that had evaporated in the vial, and the odor intensity was evaluated in increments of 0.5 based on a five-level evaluation scale of 0: no odor, 1: faint odor, 2: weak odor, 3: clear odor, and 4: strong odor. Since olfactory sensitivity varies greatly from person to person, the evaluation was performed using solutions adjusted to an appropriate concentration for each individual. First, multiple concentrations of diluted solutions were prepared for each odorant, and the odor intensity of each was evaluated. The following evaluation was performed using solutions with concentrations rated as 1.0 to 2.0 for the test substance (fragrance) and 2.5 to 3.5 for the malodor. A panel of 2-6 experts smelled the control sample and rated its odor intensity based on the 5-point scale mentioned above. They then smelled the test sample and rated how much of the odor they perceived in the control sample was detectable in the test sample. All evaluations were done blind, and the order of odors evaluated was random. Test substances that were rated as having a weaker odor than the control sample were considered to have an odor-suppressing effect. Malodors rated with an odor intensity outside the range of 2.5-3.5 were excluded from the analysis.

[0062] [Table 5]

[0063] 3) Results The evaluation results of the odor suppression effect of the test substances are shown in Figures 6 to 9. Methyl N-(3,7-dimethyl-7-hydroxyoctylidene)anthranilate, methyl 2-[(2-methylundecane-1-ylidene)amino]benzoate, and 2-methyl-2-pentenoic acid all suppressed bad odor.

Claims

1. An agent for suppressing malodor caused by a substance that activates an olfactory receptor in which copper is involved in odor perception, comprising at least one active ingredient selected from the group consisting of methyl N-(3,7-dimethyl-7-hydroxyoctylidene)anthranilate, methyl 2-[(2-methylundecane-1-ylidene)amino]benzoate, and 2-methyl-2-pentenoic acid.

2. The malodor inhibitor according to claim 1, wherein the olfactory receptor is OR2T11, OR4S2, OR2M3, OR2W1, OR2T1, OR4E2, OR2T29, OR4K17, OR2T27, OR2T5, OR2T4, OR11H2, OR6B3, OR12D3, OR6B1, OR4C15, OR2L13, or an olfactory receptor polypeptide having an equivalent function thereto.

3. The malodor suppressant according to claim 1, wherein the olfactory receptor is OR2T11, OR4S2, OR2M3, or an olfactory receptor polypeptide having an equivalent function thereto.

4. The malodor control agent according to any one of claims 1 to 3, wherein the substance is a sulfur compound.

5. The sulfur compound is furfuryl methyl sulfide, dimethyl disulfide, dimethyl trisulfide, 3-mercapto-2-methyl-1-pentanol, methyl mercaptan, ethanethiol, 1-propanethiol, 2-propanethiol, allyl mercaptan, 1-butanethiol, 2-butanethiol, 2-methyl-1-propanethiol, 2-methyl-2-propanethiol, 2-pentanethiol, 3-methyl-2-butanethiol, cyclopentanethiol, methanedithiol, (methylthio)methanethiol, 1-(methylthio) The malodor suppressant according to claim 4, which is at least one selected from the group consisting of ethanethiol, 2,3,5-trithiahexane, bis(methylthiomethyl)disulfide, thiolane-2-thiol, (ethylthio)methanethiol, thietane, dimethylsulfide, 3-mercapto-3-methylbutylformate, 3-mercapto-3-methyl-1-butanol, 1-pentanethiol, 1-hexanethiol, 1-heptanethiol, 1-octanethiol, hydrogen sulfide, 3-mercapto-3-methylbutanol and diallyl trisulfide.

6. 5. The malodor suppressant according to claim 4, wherein the sulfur compound is at least one selected from the group consisting of furfuryl methyl sulfide, dimethyl disulfide, dimethyl trisulfide and 3-mercapto-2-methyl-1-pentanol.

7. A method for suppressing malodor caused by a substance that activates an olfactory receptor in which copper is involved in odor perception, the method comprising applying to a subject in need thereof at least one selected from the group consisting of methyl N-(3,7-dimethyl-7-hydroxyoctylidene)anthranilate, methyl 2-[(2-methylundecane-1-ylidene)amino]benzoate, and 2-methyl-2-pentenoic acid.

8. The method according to claim 7, wherein the olfactory receptor is OR2T11, OR4S2, OR2M3, OR2W1, OR2T1, OR4E2, OR2T29, OR4K17, OR2T27, OR2T5, OR2T4, OR11H2, OR6B3, OR12D3, OR6B1, OR4C15, OR2L13, or an olfactory receptor polypeptide having an equivalent function thereto.

9. 9. The method of claim 7 or 8, wherein the substance is a sulfur compound.

10. The sulfur compound is furfuryl methyl sulfide, dimethyl disulfide, dimethyl trisulfide, 3-mercapto-2-methyl-1-pentanol, methyl mercaptan, ethanethiol, 1-propanethiol, 2-propanethiol, allyl mercaptan, 1-butanethiol, 2-butanethiol, 2-methyl-1-propanethiol, 2-methyl-2-propanethiol, 2-pentanethiol, 3-methyl-2-butanethiol, cyclopentanethiol, methanedithiol, (methylthio)methanethiol, 1-(methylthio) 10.) At least one selected from the group consisting of ethanethiol, 2,3,5-trithiahexane, bis(methylthiomethyl)disulfide, thiolane-2-thiol, (ethylthio)methanethiol, thietane, dimethylsulfide, 3-mercapto-3-methylbutylformate, 3-mercapto-3-methyl-1-butanol, 1-pentanethiol, 1-hexanethiol, 1-heptanethiol, 1-octanethiol, hydrogen sulfide, 3-mercapto-3-methylbutanol, and diallyl trisulfide. The method of claim 9,

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