Inhibitor of cat urine odor receptor, deodorizer for cat urine odor, method for deodorizing cat urine odor, and method for searching for cat urine odor inhibitor

Abstract

To provide an inhibitor of a cat urine odor receptor suitable for deodorizing the cat urine odor by response inhibition of the cat urine odor receptor exhibiting specific responsiveness to the cat urine odor.SOLUTION: In a preferred example, the inhibitor of the cat urine odor receptor contains at least one selected from the group consisting of trans-2-hexenal, trans-cinnamaldehyde, α - methyl-1, 3-benzodioxole-5-propanal, citral, α - damascone, ethyl dehydrocyclogeranate, and 3 - (4-tert-butylphenyl) propanal. The cat urine odor receptor is at least one selected from the group consisting of TAAR5 and polypeptides having functions equivalent to those of TAAR5.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an inhibitor of cat urine odor receptors, a deodorizer for cat urine odor, a method for deodorizing cat urine odor, and a method for searching for an inhibitor for cat urine odor. [Background technology]

[0002] The odor of animal excrement, particularly cat urine, is said to be stronger than the odor of human or dog urine, and various deodorizing products have been proposed (for example, Patent Document 1 and Patent Document 2). However, conventional methods such as those in Patent Document 1 and Patent Document 2 are difficult to achieve deodorizing effects in open or large spaces.

[0003] In recent years, the use of olfactory receptor response control has been proposed in order to obtain a more excellent deodorizing effect (for example, Patent Documents 3 and 4).

[0004] Patent Document 3 discloses a cat urine odor suppressant for cats. The cat urine odor suppressant of Patent Document 3 contains at least one active ingredient selected from the group consisting of acetylcedrene and florhydral.

[0005] Patent Document 4 discloses a method for searching for cat urine odor suppressants. The searching method in Patent Document 4 includes adding a test substance and a substance that causes cat urine odor to at least one olfactory receptor polypeptide selected from the group consisting of OR2M3 and polypeptides with equivalent functions, measuring the response of the olfactory receptor polypeptide to the substance that causes cat urine odor, and identifying a test substance that suppresses the response of the olfactory receptor polypeptide based on the measured response. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-229151 [Patent Document 2] Japanese Patent Application Laid-Open No. 2005-65750 [Patent Document 3] Japanese Patent Publication No. 2022-18279 [Patent Document 4] Japanese Patent Publication No. 2020-112520 Summary of the Invention [Problem to be solved by the invention]

[0007] In Patent Documents 3 and 4, 3-mercapto-3-methylbutyl formate and 3-mercapto-3-methyl-1-butanol, compounds specifically contained in cat urine, are used as the substances that cause cat urine odor. However, because the actual cat urine odor is a complex odor caused by multiple types of compounds, a search method using specific compounds as in Patent Documents 3 and 4 will miss compounds that originally function as cat urine odor suppressants.

[0008] In addition, the number of cat urine odor receptor candidates that specifically respond to cat urine odor is vast, and most of them are unknown. The number of cat urine odor receptor ligand candidates is also vast.

[0009] One aspect of the present invention provides an inhibitor of cat urine odor receptors, which is suitable for deodorizing cat urine odor by suppressing the response of cat urine odor receptors that exhibit specific responsiveness to cat urine odor. Another aspect of the present invention provides a method for searching for cat urine odor inhibitors, which allows comprehensive analysis of inhibitors of cat urine odor receptors. [Means for solving the problem]

[0010] The present invention has the following aspects. [1] An inhibitor that suppresses the response of at least one cat urine odor receptor selected from the group consisting of TAAR5 and polypeptides having a function equivalent to TAAR5, trans-2-Hexenal, trans-Cinnamaldehyde, α-Methyl-1,3-benzodioxole-5-propanal, Citral, α-Damascone, Ethyl Dehydrocyclogeranate, 3-(4-tert-butylphenyl)propanal, Litopentasiloxane Fruit Oil, 3-(3-Isopropylphenyl)butanal, 3,3-Dimethyl-5-(2,2,3-trimethylcyclopent-3-en-1-yl)pent-4-en-2-ol, 4,8-Dimethyl-4,9-decadienal, 4-[(Octahydro-4,7-methano-5H-inden)-5-ylidene]butanal a cat urine odor receptor inhibitor comprising at least one selected from the group consisting of 2-ethyl-3-hydroxy-γ-pyrone, 2,2,6-trimethyl-α-propylcyclohexane-1-propanol, 2-ethyl-4-(2,2,3-trimethyl-3-cyclopentenyl)-2-buten-1-ol, 3-methyl-5-(2,2,3-trimethyl-3-cyclopenten-1-yl)-4-penten-2-ol, and 3-methyl-5-phenylpentan-1-ol; [2] trans-2-Hexenal, trans-cinnamaldehyde, α-methyl-1,3-benzodioxole-5-propanal, citral, α-damascone, ethyl dehydrocyclogeranate, 3-(4-tert-butylphenyl)propanal, Litopentas crenata fruit oil, 3-(3-isopropylphenyl)butanal, 3,3-dimethyl-5-(2,2,3-trimethylcyclopent-3-en-1-yl)pentanol The cat urine odor receptor inhibitor according to [1], which contains at least one selected from the group consisting of 4-en-2-ol, 4,8-dimethyl-4,9-decadienal, 4-[(octahydro-4,7-methano-5H-inden)-5-ylidene]butanal, citronellyl butyrate, 1,1-dimethyl-2-phenylethyl acetate, p-cymene, γ-dodecanolactone, and 2-ethyl-3-hydroxy-γ-pyrone. [3] The cat urine odor receptor inhibitor according to [1] or [2], which contains at least one selected from the group consisting of trans-2-hexenal, trans-cinnamaldehyde, α-methyl-1,3-benzodioxole-5-propanal, citral, α-damascone, ethyl dehydrocyclogeranate, and 3-(4-tert-butylphenyl)propanal. [4] The cat urine odor receptor inhibitor according to [1], which contains at least one selected from the group consisting of trans-2-hexenal, 2-ethyl-3-hydroxy-γ-pyrone, 4-[(octahydro-4,7-methano-5H-inden)-5-ylidene]butanal, citral, 3,3-dimethyl-5-(2,2,3-trimethylcyclopent-3-en-1-yl)pent-4-en-2-ol, trans-cinnamaldehyde, 2,2,6-trimethyl-α-propylcyclohexane-1-propanol, 3-(4-tert-butylphenyl)propanal, 3-(3-isopropylphenyl)butanal, α-damascone, ethyl dehydrocyclogeranate, Litopenaeus littoralis fruit oil, and α-methyl-1,3-benzodioxole-5-propanal. [5] A cat urine odor deodorizer comprising the cat urine odor receptor inhibitor according to any one of [1] to [4]. [6] A method for deodorizing cat urine odor, using the inhibitor of cat urine odor receptors according to any one of [1] to [5].

[0011] [7] A method for searching for a cat urine odor suppressant, comprising: A screening method comprising mixing a test substance with at least one olfactory receptor selected from the group consisting of TAAR5 and polypeptides having functions equivalent to TAAR5. [8] The screening method described in [7], further comprising contacting the olfactory receptor with cat urine after mixing the olfactory receptor with the test substance. [9] The screening method described in [7], further comprising contacting the olfactory receptor with cat urine before mixing the olfactory receptor with the test substance. [Effects of the Invention]

[0012] According to one aspect of the present invention, there is provided an inhibitor of cat urine odor receptors that is suitable for deodorizing cat urine odor by suppressing the response of cat urine odor receptors that exhibit specific responsiveness to cat urine odor. Another aspect of the present invention provides a method for searching for cat urine odor inhibitors, which allows comprehensive analysis of inhibitors of cat urine odor receptors. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 shows the results of an experiment measuring the receptor response strength (normalized luminescence) to cat urine. [Figure 2] FIG. 2 shows the results of an experiment measuring the concentration dependency of the receptor response strength to cat urine. DETAILED DESCRIPTION OF THE INVENTION

[0014] [Terminology] A "polypeptide having a function equivalent to TAAR5" refers to a polypeptide that can be expressed on a cell membrane and that, upon binding to one or more compounds contained in cat urine, induces the production of cAMP within the cell, or promotes the influx of calcium ions from outside the cell into the cell. An "agonist" is a compound that binds to a receptor and thereby activates a response of that receptor. An "antagonist" is a compound that binds to a receptor and thereby blocks agonist activation of that receptor. The symbol "to" indicating a range of values ​​means that the values ​​before and after it are included as the lower and upper limits.

[0015] The sequence identity (homology) of an amino acid sequence can be determined as the sequence identity of a subject amino acid sequence to a reference amino acid sequence as follows. First, a reference amino acid sequence and a subject amino acid sequence are aligned, with gaps optionally included between each amino acid sequence to maximize sequence identity. Next, the number of amino acid residues that match between the reference amino acid sequence and the subject amino acid sequence is calculated, and the sequence identity can be determined according to the following formula (1).

[0016] Sequence identity (%) = (number of matching amino acid residues / total number of amino acid residues in the target amino acid sequence) × 100 Equation (1)

[0017] Hereinafter, the embodiments of the present invention will be described in detail. However, the following description relates to some examples of embodiments of the present invention and is not limited to these examples.

[0018] [Inhibitor of cat urine odor receptors] In one embodiment, the cat urine odor receptor inhibitor inhibits the response of at least one or more cat urine odor receptors selected from the group consisting of TAAR5 and polypeptides having functions equivalent to TAAR5.

[0019] Hereinafter, in this specification, an olfactory receptor for cat urine odor will be abbreviated as "cat urine odor receptor." Additionally, an olfactory receptor for at least one cat urine odor selected from the group consisting of TAAR5 and polypeptides having equivalent functions to TAAR5 will be referred to as "specific cat urine odor receptor."

[0020] The present inventors investigated various olfactory receptors and found that specific cat urine odor receptors, such as TAAR5, exhibit specific response strength to cat urine. TAAR5 has been confirmed to be expressed in human olfactory receptor neurons. Human TAAR5 is registered with GenBank (NCBI) under Gene ID: 9038. Human TAAR5 is a polypeptide consisting of the amino acid sequence of SEQ ID NO: 1.

[0021] The cat urine odor receptor may be mouse TAAR5. Mouse TAAR5 is registered with GenBank (NCBI) under Gene ID: 215854. Mouse TAAR5 is a polypeptide consisting of the amino acid sequence of SEQ ID NO: 2.

[0022] Specific cat urine odor receptors, such as TAAR5, respond specifically to the odor of cat urine. TAAR5 can be replaced with a polypeptide having a function equivalent to that of TAAR5. The amino acid sequence of a polypeptide having a function equivalent to that of TAAR5 preferably exhibits 80% or more homology with the amino acid sequence of TAAR5, more preferably 85% or more homology, even more preferably 90% or more homology, even more preferably 95% or more homology, particularly preferably 98% or more homology, and most preferably 99% or more homology.

[0023] In addition to TAAR5, any polypeptide with equivalent function can be used as a cat urine odor receptor. For example, homologous cat urine odor receptors from animals other than humans and mice can be used. Examples of animals other than humans and mice include rats and other experimental model organisms.

[0024] The present inventors have tested and investigated various substances, and as a result, they have found that trans-2-hexenal, trans-cinnamaldehyde, α-methyl-1,3-benzodioxole-5-propanal, citral, α-damascone, ethyl dehydrocyclogeranate, 3-(4-tert-butylphenyl)propanal, Litopentas crescens fruit oil, 3-(3-isopropylphenyl)butanal, 3,3-dimethyl-5-(2,2,3-trimethylcyclopent-3-en-1-yl)pent-4-en-2-ol, 4,8-dimethyl-4,9-decadienal, 4-[(octahydro-4,7-methano-5H-inden)-5-ylidene]propan ... We found that butanal, citronellyl butyrate, 1,1-dimethyl-2-phenylethyl acetate, p-cymene, γ-dodecanolactone, 2-ethyl-3-hydroxy-γ-pyrone, 2,2,6-trimethyl-α-propylcyclohexane-1-propanol, 2-ethyl-4-(2,2,3-trimethyl-3-cyclopentenyl)-2-buten-1-ol, 3-methyl-5-(2,2,3-trimethyl-3-cyclopenten-1-yl)-4-penten-2-ol, and 3-methyl-5-phenylpentan-1-ol suppressed the responses of specific cat urine odor receptors, such as TAAR5, to the odor of cat urine.

[0025] Among these, trans-2-hexenal, trans-cinnamaldehyde, α-methyl-1,3-benzodioxole-5-propanal, citral, α-damascone, ethyl dehydrocyclogeranate, 3-(4-tert-butylphenyl)propanal, Litopenaeus littoralis fruit oil, 3-(3-isopropylphenyl)butanal, 3,3-dimethyl-5-(2,2,3-trimethylcyclopentasiloxane), and 3,3-dimethyl-5-(2,2,3-trimethylcyclopentasiloxane) are particularly effective in further improving the suppression of cat urine odor receptors. At least one selected from the group consisting of (octahydro-3-en-1-yl)pent-4-en-2-ol, 4,8-dimethyl-4,9-decadienal, 4-[(octahydro-4,7-methano-5H-inden)-5-ylidene]butanal, citronellyl butyrate, 1,1-dimethyl-2-phenylethyl acetate, p-cymene, γ-dodecanolactone, and 2-ethyl-3-hydroxy-γ-pyrone is preferred as an inhibitor of cat urine odor receptors.

[0026] In addition, at least one selected from the group consisting of trans-2-hexenal, trans-cinnamaldehyde, α-methyl-1,3-benzodioxole-5-propanal, citral, α-damascone, ethyl dehydrocyclogeranate, and 3-(4-tert-butylphenyl)propanal is more preferred as an inhibitor of the cat urine odor receptor, as it more significantly improves the inhibitory performance of the cat urine odor receptor.

[0027] As inhibitors of cat urine odor receptors, trans-2-hexenal, trans-cinnamaldehyde, α-methyl-1,3-benzodioxole-5-propanal, and citral are more preferred, trans-2-hexenal and trans-cinnamaldehyde are particularly preferred, and trans-2-hexenal is most preferred.

[0028] The inhibitor of cat urine odor receptors may be used alone or in combination of two or more.

[0029] The cat urine odor receptor inhibitor according to one embodiment satisfies the following two points and is therefore thought to function as an antagonist of a specific cat urine odor receptor. - After mixing with a deterrent, the cat urine odor receptors become less responsive to the cat urine odor when they come into contact with the odor of cat urine compared to when no deterrent is mixed. - After mixing with a deterrent, cat urine odor receptors do not respond to the deterrent.

[0030] Cat urine odor receptors can be used experimentally to verify the inhibitory effects of inhibitors. Cat urine odor receptors can be used in any manner as long as they do not lose their responsiveness to cat urine. For example, cat urine odor receptors can be used in the following manners: cells or tissues naturally expressing cat urine odor receptors and their cultures; membranes of olfactory receptor cells carrying cat urine odor receptors; genetically modified cells expressing cat urine odor receptors and their cultures; membranes of genetically modified cells expressing cat urine odor receptors; lipid bilayer membranes expressing cat urine odor receptors, etc. Furthermore, tissues containing olfactory mucus (such as olfactory epithelium and olfactory mucosa) can also be used as cat urine odor receptors.

[0031] In one embodiment, the cat urine odor receptor is preferably a cell that naturally expresses the cat urine odor receptor, a genetically modified cell that expresses the cat urine odor receptor, or a culture thereof. In particular, it is preferable to use human-derived genetically modified cells that express the cat urine odor receptor. Human-derived genetically modified cells can be prepared, for example, by transforming cultured human cells with a vector incorporating a gene encoding the cat urine odor receptor.

[0032] When cat urine odor receptors are used experimentally, metal ions may also be used. The manner in which the metal ions are used and present is not particularly limited. Examples include a method of mixing a cat urine odor receptor with a test substance in a metal ion-containing solution; a method of mixing a membrane carrying a cat urine odor receptor or cells or tissues expressing the cat urine odor receptor with a test substance while immersed in a metal ion-containing solution; a method of adding a metal ion to a culture medium for culturing cells or tissues expressing the cat urine odor receptor, and then adding the test substance; and a method of mixing a metal ion-containing solution together with a test substance into a culture medium for culturing cells or tissues expressing the cat urine odor receptor. Examples of metal ions include copper ions and silver ions.

[0033] To observe the response of the cat urine odor receptor, the volume of buffer solution can be reduced. For example, when using a 96-well plate, the cat urine odor receptor and cat urine odor can be contacted with 25 μL or less of buffer solution. If the volume of buffer solution is relatively small, the cat urine odor is less likely to be converted by the buffer solution, making it easier to observe the response.

[0034] When considering application to cat urine odor deodorizers and deodorizing methods, it is more preferable to use inhibitors whose deodorizing effects have been confirmed in sensory tests.

[0035] (Action and effect) The cat urine odor receptor inhibitor functions as an antagonist of specific cat urine odor receptors that specifically respond to the odor of cat urine, and therefore, the cat urine odor receptor inhibitor of one embodiment can inhibit the response of these specific cat urine odor receptors.

[0036] Cat urine odor receptor inhibitors can suppress the response of specific cat urine odor receptors to cat urine. Therefore, the concentration required to achieve the same level of deodorizing effect in the target space can likely be set lower than in the case of conventional physical or chemical deodorization. Therefore, there is no need to present the cat urine odor receptor inhibitor in the target space at a higher concentration than cat urine. For these reasons, cat urine odor receptor inhibitors are useful as active ingredients in cat urine odor deodorizers.

[0037] [Application example of cat urine odor receptor inhibitor] According to one embodiment, a cat urine odor deodorizer is provided, which contains the cat urine odor receptor inhibitor described above. According to one embodiment, the cat urine odor receptor inhibitor binds to the cat urine odor receptor, thereby suppressing the response of the cat urine odor receptor to cat urine. As a result of inhibiting the perception of cat urine odor, a deodorizing effect is exerted.

[0038] Since cat urine odor receptor inhibitors are antagonists, they compete with cat urine to inhibit the response of cat urine odor receptors and the perception of cat urine odor. Therefore, there is less need to maintain a diffused state beforehand, as is the case with conventional physical and chemical deodorizers. Therefore, cat urine odor receptor inhibitors are also suitable for instantaneous deodorizing applications such as sprays.

[0039] The deodorizer may be in the form of a composition or may be comprised of an inhibitor of cat urine odor receptors. In the case of a composition, the inhibitor of cat urine odor receptors is contained in the composition as an active ingredient for suppressing cat urine odor.

[0040] The composition may further contain other ingredients besides the cat urine odor receptor inhibitor, such as fragrances and additives, as long as the cat urine odor suppressing effect of the cat urine odor receptor inhibitor is not impaired.

[0041] The fragrance may be a natural fragrance, a single fragrance isolated from a natural fragrance, a synthetic single fragrance, or a blend of these. Conventionally known oil-based fragrances can be used without any restrictions as the fragrance.

[0042] The flavoring agent is not particularly limited, but examples thereof include animal-derived flavoring agents, plant-derived flavoring agents, synthetic flavoring agents, and extracted flavoring agents. One type of flavoring agent may be used alone, or two or more types may be used in combination.

[0043] The animal-derived fragrances are not particularly limited, but examples thereof include musk, spirit cat fragrance, and dragon jasmine fragrance. Examples of plant-based flavorings include, but are not limited to, abies oil, accion oil, almond oil, angelica root oil, peper oil, bergamot oil, perch oil, bois basil oil, kajabuchi oil, gananga oil, capsicum oil, caraway oil, cardamom oil, cassia oil, celery oil, cinnamon oil, citronella oil, cognac oil, coriander oil, cumin oil, camphor oil, dill oil, estgolan oil, eucalyptus oil, fennel oil, garlic oil, ginger oil, grapefruit oil, hop oil, lemon oil, lemongrass oil, nutmeg oil, mandarin oil, peppermint oil, orange oil, sage oil, star anise oil, and turpentine. The animal-derived flavorings and plant-derived flavorings may be used alone or in combination of two or more.

[0044] Artificial fragrances such as synthetic fragrances and extracted fragrances are not particularly limited, but examples thereof include hydrocarbon fragrances such as pinene and limonene; alcohol fragrances such as linalool, tetrahydrolinalool, geraniol, citronellol, 2-isobutyl-4-methyltetrahydro-2H-pyran-4-ol, menthol, borneol, benzyl alcohol, anise alcohol, and β-phenethyl alcohol; phenol fragrances such as anethole and eugenol; and alcohols such as 3-(4-tert-butylphenyl)propanal, n-butyraldehyde, isobutyraldehyde, hexylaldehyde, citral, citronellal, benzaldehyde, cinnamic aldehyde, and cumin aldehyde. Aldehyde-based fragrances; ketone-based fragrances such as 1-(2,3,8,8-tetramethyl-1,2,3,4,5,6,7,8-octahydronaphthalen-2-yl)ethan-1-one, carvone, menthone, camphor, acetophenone, and ionone; lactone-based fragrances such as γ-butyl lactone, coumarin, and cineole; ester-based fragrances such as methyl dihydrojasmonate, 1,1-dimethyl-2-phenylethyl acetate, 2,2,2-trichloro-1-phenylethyl acetate, hexyl acetate, octyl acetate, benzyl acetate, styrallyl acetate, cinnamyl acetate, linalyl acetate, butyl propionate, and methyl benzoate; and benzopyran-based fragrances such as galaxolide. The artificial flavoring may be used alone or in combination of two or more kinds. The additives may be used alone or in combination of two or more.

[0045] The content of the cat urine odor receptor inhibitor in the blended fragrance is preferably at least 1% by mass, more preferably 5% by mass or more, and even more preferably 10% by mass or more. If the content of the cat urine odor receptor inhibitor is equal to or greater than the lower limit, it is considered that when used as a deodorant, it is sufficient to deodorize the cat urine odor by suppressing the response of the cat urine odor receptor.

[0046] The deodorizer may be carried to the object to be suppressed from cat urine odor, may be placed in a space where cat urine odor may occur, or may be mixed with a substance that may cause cat urine odor.

[0047] According to one embodiment, a method for deodorizing cat urine odor is provided using the above-mentioned cat urine odor receptor inhibitor. According to the deodorizing method of one embodiment, the cat urine odor receptor inhibitor binds to the cat urine odor receptor, thereby suppressing the response of the cat urine odor receptor to the cat urine odor. As a result of inhibiting the perception of the cat urine odor, a deodorizing effect is exerted.

[0048] Another embodiment provides a method for suppressing cat urine odor using a cat urine odor receptor inhibitor. In the method for suppressing cat urine odor, the cat urine odor receptor inhibitor is applied to a subject (individual) whose perception of cat urine odor is to be suppressed. The cat urine odor receptor inhibitor may be applied before the subject is exposed to cat urine, after the subject is exposed to cat urine, or simultaneously with the subject being exposed to cat urine.

[0049] In one embodiment, a cat urine odor receptor inhibitor is applied to a subject whose cat urine odor is to be inhibited before the subject is exposed to cat urine. The applied cat urine odor receptor inhibitor inhibits the response of the cat urine odor receptor of the subject. As a result, even if the subject is exposed to cat urine, the response of the cat urine odor receptor to cat urine is inhibited, and the perception of the cat urine odor is inhibited.

[0050] Examples of applications include animal toilets or excrement treatment; excrement treatment in veterinary medical facilities and commercial facilities; waste treatment; odor treatment in veterinary medical facilities and commercial facilities; odor treatment in trash cans; fabric products; and topical products such as cosmetics, cleaning agents, and deodorants. However, the application of the cat urine odor receptor inhibitor is not limited to these examples.

[0051] [Method for searching for cat urine odor suppressants] The method for searching for cat urine odor inhibitors involves mixing a cat urine odor receptor with a test substance. If the test substance inhibits the response of the cat urine odor receptor when added to the cat urine odor receptor, the test substance is likely to exhibit a sufficient deodorizing effect against cat urine odor. A test substance that inhibits the response of the cat urine odor receptor to cat urine is considered to be useful as a cat urine odor inhibitor. Unlike Patent Documents 3 and 4, this embodiment uses actual cat urine, allowing for comprehensive analysis of inhibitors of the cat urine odor receptor. As a result, compounds that function as cat urine odor inhibitors are less likely to be overlooked.

[0052] (Mixture of cat urine odor receptor and test substance) When the cat urine odor receptor is mixed with the test substance, the cat urine odor receptor may be the cat urine odor receptor after contact with cat urine, or the cat urine odor receptor may be the cat urine odor receptor before contact with cat urine.

[0053] By mixing the cat urine odor receptor with a test substance, data can be obtained to determine whether the test substance functions as an antagonist of the cat urine odor receptor. If the test substance functions as an antagonist, it can be expected to be useful as a cat urine odor suppressant.

[0054] If the following two conditions are satisfied at the cat urine odor receptor after mixing with the test substance, the test substance can be considered to function as an antagonist. After mixing with the test substance, the cat urine odor receptor becomes less responsive to cat urine than when the test substance is not mixed. After mixing with the test substance, the cat urine odor receptors do not respond to the test substance.

[0055] The cat urine odor receptor can be used in any manner as long as it does not lose its responsiveness to cat urine. For example, the cat urine odor receptor can be used in the following manner: cells or tissues naturally expressing the cat urine odor receptor and their cultures; membranes of olfactory receptor cells carrying the cat urine odor receptor; genetically modified cells expressing the cat urine odor receptor and their cultures; membranes of genetically modified cells expressing the cat urine odor receptor; lipid bilayer membranes expressing the cat urine odor receptor, etc. Furthermore, tissues containing olfactory mucus (such as the olfactory epithelium and olfactory mucosa) can also be used as the cat urine odor receptor.

[0056] In one embodiment, the cat urine odor receptor is preferably a cell that naturally expresses the cat urine odor receptor, a genetically modified cell that expresses the cat urine odor receptor, or a culture thereof. In particular, it is preferable to use human-derived genetically modified cells that express the cat urine odor receptor. Human-derived genetically modified cells can be prepared, for example, by transforming cultured human cells with a vector incorporating a gene encoding the cat urine odor receptor.

[0057] The specific method for measuring the response of the cat urine odor receptor is not particularly limited. For example, the amount of intracellular cAMP can be measured. The response of the cat urine odor receptor can be evaluated by using the amount of intracellular cAMP as an indicator of the response of the cat urine odor receptor. Examples of methods for measuring the amount of intracellular cAMP include ELISA and reporter gene assay.

[0058] Other examples include calcium imaging and electrophysiological measurements. In electrophysiological measurements, for example, test cells (e.g., Xenopus oocytes) co-expressing the cat urine odor receptor with other ion channels may be prepared, and the action potential of the ion channel on the test cell may be measured by patch clamping, two-electrode voltage clamping, or the like.

[0059] The test substance is a substance to be tested to determine its suitability as an inhibitor of cat urine odor receptors, and therefore, the test substance is not particularly limited. The test substance is typically a substance desired for use as a cat urine odor suppressant. The test substance may be a naturally occurring substance or a synthetic substance.

[0060] Considering that the cat urine odor suppressant will be commercialized as a deodorizer, the test substance is preferably a substance that gives off an odor different from the cat urine odor, and more preferably a volatile substance. It is also preferable to use an odorless test substance or a test substance with a low odor intensity. The test substance may be a single substance or a mixture containing two or more substances. For example, a single fragrance substance or a blend of fragrance substances may be used.

[0061] The method for adding the test substance is not particularly limited. The test substance may be mixed into the culture medium for cells expressing the cat urine odor receptor, or the test substance may be dripped, sprinkled, or sprayed onto cells, tissues, etc. expressing the cat urine odor receptor.

[0062] When adding a test substance to a cat urine odor receptor, it may be mixed in the presence of a metal ion. The manner in which the metal ion is used and the manner in which it is present are not particularly limited. For example, the following methods can be used.

[0063] A method in which cat urine odor receptors are mixed with test substances in a metal ion-containing solution. A method in which a membrane carrying cat urine odor receptors or cells or tissues expressing cat urine odor receptors is immersed in a metal ion-containing solution and mixed with a test substance. A method in which metal ions are added to a culture medium in which cells or tissues expressing cat urine odor receptors are cultured, and then a test substance is added. A method in which a test substance and a liquid containing metal ions are mixed into a culture medium for culturing cells or tissues expressing cat urine odor receptors.

[0064] To observe the responsiveness of the cat urine odor receptor, the volume of buffer solution may be reduced. For example, when using a 96-well plate, the cat urine odor receptor and cat urine odor can be contacted under conditions where the buffer solution is 25 μL or less. A relatively small volume of buffer solution may reduce the conversion of the cat urine odor due to the action of the buffer solution, making it easier to observe the responsiveness. For example, when culturing the cat urine odor receptor in a well plate, the well plate is turned upside down with the lid removed. At this time, some of the liquid in the well remains on the bottom of each well, and the volume of liquid in the well can be reduced by turning the well plate upside down. After reducing the volume of liquid in the well, mixing the cat urine odor receptor with the test substance may make it easier to observe the responsiveness of the cat urine odor receptor to the test substance.

[0065] (contact between cat urine odor receptors and cat urine) The method for searching for cat urine odor suppressants may further include mixing the cat urine odor receptor with the test substance, and then contacting the cat urine odor receptor with cat urine. In this case, the following Reference Data 1 and Test Data 1 can be obtained.

[0066] Reference data 1: Data measuring the response of cat urine odor receptors in the presence of test substances before contact with cat urine. Test Data 1: Data measuring the response of cat urine odor receptors after contact with cat urine in the presence of test substances.

[0067] The response of the cat urine odor receptor in the presence of the test substance can be evaluated before and after contact with cat urine by comparing the reference data 1 and the test data 1. For example, if the response of the cat urine odor receptor is suppressed before and after contact with cat urine, the test substance may be useful as a cat urine odor suppressant.

[0068] The method for searching for cat urine odor suppressants may further include contacting the olfactory receptor with cat urine before mixing the cat urine odor receptor with the test substance. In this case, the following Reference Data 2 and Comparative Data 2 can be obtained.

[0069] Reference data 2: Data measuring the response of cat urine odor receptors after contact with cat urine but before addition of test substance. Test data 2: Data measuring the response of cat urine odor receptors when a test substance was added after contact with cat urine.

[0070] The response of cat urine odor receptors already activated by cat urine can be evaluated before and after the addition of the test substance by comparing Reference Data 2 and Test Data 2. For example, if the response index of the cat urine odor receptor in Test Data 2 is statistically significantly reduced compared to Reference Data 2, the test substance may be useful as a cat urine odor suppressant.

[0071] The type of buffer solution is not particularly limited, but examples include PBS (phosphate buffered saline), DPBS (Dulbecco's phosphate buffered saline), HBSS (Hank's balanced salt solution), and EBSS (Earle's balanced salt solution). HBSS is preferably used.

[0072] The buffer solution may contain various aminoethanesulfonic acids or aminopropanesulfonic acid derivatives having a Zwitterion structure, such as EPPS (4-(2-hydroxyethyl)-1-piperazinepropanesulfonic acid), HEPES (4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid), MES (2-morpholinoethanesulfonic acid), MOPS (3-morpholinopropanesulfonic acid), and PIPES (piperazine-1,4-bis(2-ethanesulfonic acid)). The concentration of the aminoethanesulfonic acid or aminopropanesulfonic acid derivative is not particularly limited, and may be, for example, 0.1 to 100 mmol / L, 1 to 125 mol / L, or 5 to 10 mmol / L.

[0073] The manner in which the cat urine odor receptor is brought into contact with cat urine is not particularly limited. For example, the following methods can be mentioned.

[0074] A method in which a membrane carrying cat urine odor receptors or cells or tissues expressing cat urine odor receptors is placed in a sealed container containing cat urine. A method in which a membrane carrying a cat urine odor receptor or a cell or tissue in which the cat urine odor receptor is expressed is placed in a sealed container, and then cat urine is supplied into the sealed container.

[0075] When cat urine is brought into contact with the cat urine odor receptor, the cat urine may be in a gaseous, liquid, or solid state. Cat urine consisting of a single component may be used, but a complex odor in combination with a malodorous substance other than cat urine, or an odor collected from any space containing cat urine may also be used.

[0076] In terms of reproducing actual olfactory behavior, it is preferable to use gaseous cat urine odor. By using cat urine odor, the ligand search conditions can be made closer to the reaction conditions of the cat urine odor receptor in the actual nose. Then, it is possible to search for inhibitors or antagonists of the cat urine odor receptor that respond to cat urine odor. It is believed that cat urine odor inhibitors selected in this way are likely to exhibit deodorizing effects when actually used in products such as deodorants.

[0077] However, in other embodiments, liquid cat urine may be vaporized in a sealed container, etc. A culture plate, a petri dish, or a circulator may be used to bring the cat urine into contact with the cat urine odor receptor in the sealed container.

[0078] In one embodiment, a cell culture plate having multiple wells may be used. While the number of wells is not particularly limited, a 96-well plate is preferred. The well bottom may be flat, round, V-bottom, U-bottom, easy-wash bottom, or half-area solid, with flat bottoms being preferred. The opening diameter is also not particularly limited, but is 3-8 mm, preferably 5-7 mm, the bottom diameter is 2-7 mm, preferably 3-6.5 mm, and the maximum volume is 30-450 μL, preferably 200-400 μL. For example, cells or tissues expressing cat urine odor receptors and a test substance are dispensed and mixed into each of the multiple wells of a cell culture plate, and cat urine is supplied around the periphery of the cell culture plate or into the gaps in the well plate to bring the cat urine into contact with the cat urine odor receptor.

[0079] By premixing the test substance with the cat urine odor receptor in this way, the cat urine odor receptors in each well can be brought into contact with the cat urine so that the response time to the malodor of the cat urine odor receptors in each well is synchronized. Therefore, there is less of a time lag between the response time of each well, which occurs when cat urine is added to the cat urine odor receptors in each well one by one in advance and then the response of the cat urine odor receptor is measured.

[0080] In this case, it is possible to obtain cat urine odor receptor response data (reference data 1 and test data 1 described above) with less measurement error. When using a cell culture plate with multiple wells, the cat urine odor receptors in each well may be identical or different.

[0081] To observe the responsiveness of the cat urine odor receptor, the volume of buffer solution can be reduced. For example, when using a 96-well plate, the cat urine odor receptor and cat urine odor can be contacted under conditions where the buffer solution is 25 μL or less. If the buffer solution volume is relatively small, the cat urine odor is less likely to be converted by the buffer solution, making it easier to observe the responsiveness. For example, when culturing the cat urine odor receptor in a well plate, the well plate can be turned upside down with the lid removed. At this time, some of the liquid in the well will remain on the bottom of each well, and by turning the well plate upside down, the volume of liquid in the well can be reduced. After reducing the volume of liquid in the well, mixing the cat urine odor receptor and cat urine may make it easier to observe the responsiveness of the cat urine odor receptor.

[0082] (sensory test) In one embodiment, a sensory test may be further performed. For example, a test substance that is expected to be useful as a cat urine odor suppressant may be used as a candidate substance for a cat urine odor deodorizer, and the cat urine odor suppression effect of the candidate substance may be evaluated by a sensory test. A candidate substance that is confirmed to have a cat urine odor suppression effect in the sensory test may be selected as a cat urine odor deodorizer.

[0083] The sensory test can be performed according to a normal evaluation procedure for deodorants. For example, the evaluator may smell the cat urine odor simultaneously with the odor of the candidate substance and evaluate the intensity of the cat urine odor, or may smell the cat urine odor separately from the odor of the candidate substance and evaluate the intensity of the cat urine odor. The evaluation results obtained are compared with the intensity of the cat urine odor alone. Candidate substances that are evaluated as reducing the intensity of the cat urine odor as a result of the sensory test are expected to be useful as cat urine odor suppressants.

[0084] Although several embodiments have been described above, each embodiment is presented as an example and does not limit the scope of the present invention. Each embodiment described in this specification can be modified in various ways within the scope of the effects of the invention, and can be combined with features described in other embodiments within the scope of feasibility.

[0085] The present invention will be described in more detail below by showing the results of experiments conducted by the inventors, although the present invention is not limited to the results of the experiments.

[0086] [Preparation of human olfactory receptor expressing cells] Based on sequence information registered in GenBank, genes encoding 415 types of olfactory receptors, as shown in Tables 1 and 2, were cloned. Each gene was cloned by PCR using human genomic DNA Human mixed (G3041: Promega) as a template. Each gene amplified by PCR was inserted into a pCI vector (Invitrogen) according to the manufacturer's protocol. Specifically, a Rho tag sequence was inserted using the NheI and BamHI restriction enzyme sites present in the pCI vector. The olfactory receptor gene was inserted downstream of the Rho tag sequence using the MluI and NotI restriction enzyme sites downstream of the Rho tag sequence. Next, the gene encoding human RTP1S was inserted into the MluI and NotI restriction enzyme sites of the pCI vector.

[0087] [Table 1]

[0088] [Table 2]

[0089] Hana3A cells were cultured in a 96-well plate (Corning, BioCoat) until they reached 50% confluence. A reaction solution with the composition shown in Table 3 was prepared and left to stand in a clean bench for 15 minutes. 50 μL of the solution was then added to each well of the 96-well plate (Corning, BioCoat). After culturing for 24 hours in an incubator maintained at 37°C and a 5% CO2 atmosphere, Hana3A cells expressing each of the 415 olfactory receptors listed in Tables 1 and 2 were prepared.

[0090] [Table 3]

[0091] [Glo Sensor Assay] A Glo Sensor assay was performed to measure the response of olfactory receptors. Cat urine was used as the odorant. Because the odor of cat urine varies in intensity from day to day, it was collected in separate vials from a 6-year-old neutered male cat for seven days. Urine collected on five different days was used. Because the odor differed on each collection day, urine was separated into those with a strong pungent odor and those with a mild pungent odor. Samples with the same level of irritation were then mixed. The mixed strong and mild urine samples were then mixed at the desired concentrations to prepare the odorant.

[0092] The olfactory receptors expressed in Hana3A cells couple with endogenous Gαs and Gαlf, activating adenylate cyclase and increasing the intracellular cAMP level. The increase in intracellular cAMP was measured as luminescence from the firefly luciferase gene, and the response strength of the olfactory receptors was measured.

[0093] Luciferase activity was measured using Glo Sensor cAMP Reagent (Promega) according to the product protocol. For each stimulation condition, the luciferase-derived luminescence value after odor stimulation was divided by the luciferase-derived luminescence value before odor stimulation. In other words, (luminescence value after stimulation) / (luminescence value before stimulation) was calculated. The response intensity induced by odorant stimulation was measured as (luminescence value after stimulation) / (luminescence value before stimulation).

[0094] [Search for cat urine odor receptors that respond to cat urine odor] (Identification of TAAR5) The medium was removed from the culture of olfactory receptor-expressing cells. Then, 25 μL of Glo Sensor cAMP Reagent diluted with HBSS buffer containing 10 mM HEPES was added to each well of a 96-well plate. The cells were cultured in a dark environment for 2-3 hours to allow the cAMP Reagent to be introduced into the cells.

[0095] Next, 25 μL of a 30 vol% aqueous solution of cat urine with a mild odor containing 5 vol% cat urine with a strong odor was added between the wells of a 96-well plate. The odor molecules were allowed to come into contact with human and mouse cat urine odor receptors, including mouse TAAR5, in the gas phase for 15 minutes. The response strength (fold increase) of the cat urine odor receptor to cat urine was measured over time, and the total response strength over the 15 minutes was calculated. The results are shown in Figure 1.

[0096] The vertical axis of Figure 1 shows the relative response strength of each receptor-expressing cell to the cat urine odor (Figure 1). The relative response strength was calculated by setting the response strength in the absence of cat urine odor receptors at 0. The response to cat urine odor was measured for each of the 415 olfactory receptor-expressing cells. As a result, mouse TAAR5, which showed the highest response to cat urine odor, was identified as the cat urine odor receptor (Figure 1).

[0097] (Concentration dependence of TAAR5 response to cat urine odor) 25 μL of a 7.5 vol% aqueous solution of cat urine with a milder odor containing 5% or 7.5% cat urine with a stronger odor was added between the wells of a 96-well plate, and the response of each receptor-expressing cell to the cat urine was measured. The results are shown in Figure 2. As a result, TAAR5 showed a concentration-dependent response to the cat urine odor. This confirmed that TAAR5 is an olfactory receptor that specifically responds to the cat urine odor.

[0098] [Test substance] The following compounds were used as test substances (Compounds) and diluted with HBSS buffer containing 10 mM HEPES to a final concentration of 100 μM. trans-2-Hexenal trans-Cinnamaldehyde α-Methyl-1,3-benzodioxole-5-propanal Citral α-damascone Ethyl dehydrocyclogeranate 3-(4-tert-butylphenyl)propanal Licorice fruit oil 3-(3-isopropylphenyl)butanal 3,3-Dimethyl-5-(2,2,3-trimethylcyclopent-3-en-1-yl)pent-4-en-2-ol 4,8-Dimethyl-4,9-decadienal 4-[(octahydro-4,7-methano-5H-inden)-5-ylidene]butanal Citronellyl Butyrate 1,1-Dimethyl-2-phenylethyl acetate p-Cymene γ-Dodecanolactone 2-Ethyl-3-hydroxy-γ-pyrone 2,2,6-trimethyl-α-propylcyclohexane-1-propanol 2-Ethyl-4-(2,2,3-trimethyl-3-cyclopentenyl)-2-buten-1-ol 3-Methyl-5-(2,2,3-trimethyl-3-cyclopenten-1-yl)-4-penten-2-ol 3-Methyl-5-phenylpentan-1-ol Undecanal Nopyracetate Ethylene glycol brassillate

[0099] [Screening for antagonists of mouse TAAR5] The medium was removed from cultures of mouse TAAR5-expressing cells. Then, 25 μL of GloSensor cAMP Reagent diluted in HBSS buffer containing 10 mM HEPES was added to each well of a 96-well plate. The cells were cultured in a dark environment for 2-3 hours to allow the cAMP Reagent to be introduced into the cells. The GloSensor assay was then performed to measure the response intensity of mouse TAAR5 before the addition of the test substance.

[0100] Next, the test substance was added to each well of the 96-well plate to give a final concentration shown in Table 4 or Table 5. Five minutes later, a GloSensor assay was performed to measure the response strength (fold increase) of mouse TAAR5 to the test substance.

[0101] Next, 25 μL of a 30 vol% aqueous solution of cat urine with a mild odor containing 10 vol% cat urine with a strong odor was added between the wells of a 96-well plate. A GloSensor assay was performed, and mouse TAAR5 was exposed to the odor molecules for 15 minutes. The response strength (fold increase) of mouse TAAR5 to the odor molecules was measured over time.

[0102] The response intensity to the test substance was calculated by dividing the luciferase-derived luminescence value 5 minutes after the addition of the test substance by the luciferase-derived luminescence value before the addition of the test substance, i.e., (luminescence value 5 minutes after the addition of the test substance) / (luminescence value before the addition of the test substance) was calculated to obtain reference data.

[0103] The response intensity when cat urine and the test substance were mixed was calculated by calculating the response value induced by cat urine stimulation every minute for 1 minute and summing the values ​​for 15 minutes. The 1-minute response value was calculated as (luminescence value after cat urine stimulation at each time) / (luminescence value 5 minutes after addition of the test substance). The obtained response value was then divided by the response value when only cat urine was added. In other words, (response value when cat urine and the test substance were mixed) / (response value from cat urine only) was calculated to obtain the test data. The measurement results are shown in Tables 4 and 5.

[0104] [Table 4]

[0105] [Table 5]

[0106] As shown in Tables 4 and 5, the test data measurements showed that the following compounds were detected: trans-2-hexenal, trans-cinnamaldehyde, α-methyl-1,3-benzodioxole-5-propanal, citral, α-damascone, ethyl dehydrocyclogeranate, 3-(4-tert-butylphenyl)propanal, Litopentas crenata fruit oil, 3-(3-isopropylphenyl)butanal, 3,3-dimethyl-5-(2,2,3-trimethylcyclopent-3-en-1-yl)pent-4-en-2-ol, 4,8-dimethyl-4,9-decadienal, 4-[(octahydro-4,7-methano-5H-inden)-5-ylidene]butanal The following compounds suppressed the response of mouse TAAR5 to cat urine odor: citronellyl butyrate, 1,1-dimethyl-2-phenylethyl acetate, p-cymene, γ-dodecanolactone, 2-ethyl-3-hydroxy-γ-pyrone, 2,2,6-trimethyl-α-propylcyclohexane-1-propanol, 2-ethyl-4-(2,2,3-trimethyl-3-cyclopentenyl)-2-buten-1-ol, 3-methyl-5-(2,2,3-trimethyl-3-cyclopenten-1-yl)-4-penten-2-ol, and 3-methyl-5-phenylpentan-1-ol. These compounds are believed to function as antagonists of mouse TAAR5, and are likely to be effective deodorizers against cat urine odor.

[0107] In contrast, as shown in Table 5, undecanal, nopyracetate, and ethylene glycol brassylate were not found to have an inhibitory effect on the response of TAAR5 to the odor of cat urine.

[0108] [Test substances used in sensory test 1] The following test substances were used to test their deodorizing effect on cat urine odor. trans-2-Hexenal 2-Ethyl-3-hydroxy-γ-pyrone 4-[(octahydro-4,7-methano-5H-inden)-5-ylidene]butanal Citral 3,3-Dimethyl-5-(2,2,3-trimethylcyclopent-3-en-1-yl)pent-4-en-2-ol trans-Cinnamaldehyde 2,2,6-trimethyl-α-propylcyclohexane-1-propanol 3-(4-tert-butylphenyl)propanal 3-(3-isopropylphenyl)butanal α-damascone Ethyl dehydrocyclogeranate Licorice fruit oil α-Methyl-1,3-benzodioxole-5-propanal

[0109] [Contents of Sensory Test 1] Sensory Test 1 was conducted by 10 evaluators. The 10 evaluators were men and women in their 20s or 30s who had passed a separately conducted olfactory test.

[0110] The fragrance masterbatch was prepared as follows. A piece of test paper cut to approximately 4 cm was prepared. One drop (approximately 0.02 g) of a solution of each test substance diluted to 1% with DMSO was impregnated onto the test paper. The test paper was then sealed in a 3 L bag and filled with odorless air. The bag was left to stand overnight at room temperature to obtain a fragrance masterbatch with a concentration of 1% of each test substance.

[0111] Each test sample was diluted to 10% with DMSO, and then further diluted to a concentration of 0.01% with triethyl citrate. Separately prepared test paper cut to approximately 4 cm was used. One drop (approximately 0.02 g) of the diluted solution was impregnated onto the test paper. The test paper was then sealed in a 3 L bag, and the bag was filled with odorless air. The test paper was left to stand overnight at room temperature, yielding a fragrance masterbatch with a concentration of 0.01% for each test substance.

[0112] The cat urine masterbatch was prepared as follows. 4 g of cat urine was impregnated into a 5.5 cm diameter pleated filter paper. The pleated filter paper was then sealed in a 10 L bag together with a fan, and the bag was filled with odorless air. The bag was left to stand overnight at room temperature to obtain a cat urine masterbatch.

[0113] The evaluation samples were prepared as follows: The scented air from each scent masterbatch was transferred to a 3L bag. Then, 200ml to 300ml of the cat urine masterbatch was poured into the 3L bag so that the odor intensity was 3 to 4, as defined by the Aromatic Deodorizer Council. The 3L bag was then filled with odorless air to obtain each test sample. Another 3L bag was filled with odorless air, and 200ml of the cat urine masterbatch was poured into it (cat urine only sample).

[0114] The evaluation test was carried out as follows. Each sample was presented to an evaluator, who scored the cat urine intensity according to the following criteria. The average scores of 9 or 10 evaluators for the difference in malodor intensity between the malodor-only sample and the evaluation sample in which scented air was injected into cat urine are shown in Table 6.

[0115] [Standards for odor intensity] The evaluation was conducted on a six-point scale from +5 points to 0 points in increments of 1 point using the following evaluation criteria. +5:Intense +4: Strong +3: Easily detectable +2: Weak +1: Finally able to sense it 0: Odorless

[0116] [Table 6]

[0117] This test adopted the sensory deodorizing test standards established by the Association of Deodorizers and Fragrances, which considers a product to have a deodorizing effect if it reduces the intensity of the malodor by one level or more. The results of sensory test 1 confirmed that trans-2-hexenal, 2-ethyl-3-hydroxy-γ-pyrone, 4-[(octahydro-4,7-methano-5H-inden)-5-ylidene]butanal, citral, 3,3-dimethyl-5-(2,2,3-trimethylcyclopent-3-en-1-yl)pent-4-en-2-ol, trans-cinnamaldehyde, 2,2,6-trimethyl-α-propylcyclohexane-1-propanol, 3-(4-tert-butylphenyl)propanal, 3-(3-isopropylphenyl)butanal, α-damascone, ethyl dehydrocyclogeranate, Litopenaeus littoralis fruit oil, and α-methyl-1,3-benzodioxole-5-propanal had sensory deodorizing effects against cat urine odor.

[0118] [Confirmation of the ability of compound fragrances to suppress mouse TAAR5] As shown in Table 7 below, floral-like blended fragrance 1, floral-like blended fragrance 2, fruity-like blended fragrance, and citrus-like blended fragrance were prepared by blending each of the test substances. Each blended fragrance contains the compound indicated in the column marked with "+" in the table. Floral-like blended fragrance 1, floral-like blended fragrance 2, fruity-like blended fragrance, and citrus-like blended fragrance were all prepared by Takasago International Corporation.

[0119] [Table 7]

[0120] The response intensity of mouse TAAR5 was measured for the blended fragrances shown in Table 7, and the results are shown in Table 8. For comparison, the response intensity of mouse TAAR5 was measured for each blended fragrance from which all test substances exhibiting antagonistic effects had been removed, and the results are shown in Table 8. The fruity blended fragrance and the fruity blended fragrance from which all test substances exhibiting antagonistic effects had been removed were measured at a concentration of 10%, while the other fragrances were measured at a concentration of 1%. The response intensity when cat urine and the test substance were mixed was calculated as (luminescence value after stimulation with cat urine 20 minutes later) / (luminescence value 5 minutes after addition of the test substance).

[0121] [Table 8]

[0122] As shown in Table 8, the response intensity measurements showed that the floral fragrance 1, floral fragrance 2, fruity-like compound fragrance, and citrus-like compound fragrance, each containing the test substance, suppressed the response of mouse TAAR5 to the cat urine odor, suggesting that they function as antagonists of mouse TAAR5. These are considered to be inhibitors that are likely to fully exert their deodorizing effect against cat urine odor.

[0123] [Sensory test 2] The compounded fragrances shown in Table 7 were used to test the deodorizing effect on cat urine odor. For comparison, a test was also conducted on each compounded fragrance from which all test substances showing antagonist effects had been removed. Sensory Test 2 was conducted by eight evaluators. The eight evaluators consisted of men and women in their 20s or 30s who had passed a separate olfactory test.

[0124] The fragrance masterbatch was prepared as follows. Each compounded fragrance was diluted to 8% using an isoparaffin-based solvent and a glycol ether-based solvent, and added to the bottle containing the volatiles. The mixture was then sealed in a 10L bag, and the inside was filled with odorless air. The mixture was left to stand at room temperature for 30 minutes to obtain a masterbatch.

[0125] The evaluation samples were prepared as follows: The scented air from each scent masterbatch was transferred to a 3L bag. Then, 50ml of the cat urine masterbatch, made using 2g of cat urine, was poured into the 3L bag to obtain each test sample. Another 3L bag was filled with odorless air, and 50ml of the cat urine masterbatch was poured into it (cat urine only sample).

[0126] The evaluation test was carried out as follows. Each sample was presented to an evaluator, who scored the cat urine intensity according to the following criteria. The average scores of the eight evaluators for the difference in malodor intensity between the malodor-only sample and the evaluation sample in which scented air was injected into cat urine are shown in Table 9.

[0127] [Standards for odor intensity] The evaluation was conducted on a six-point scale from +5 points to 0 points in increments of 1 point using the following evaluation criteria. +5:Intense +4: Strong +3: Easily detectable +2: Weak +1: Finally able to sense it 0: Odorless

[0128] [Table 9]

[0129] This test also adopted the sensory deodorizing test standards established by the Association of Deodorizers and Fragrances. As mentioned above, the Association considers a product to have a deodorizing effect if the odor intensity is reduced by one level or more. The results of sensory test 2 confirmed that the fruity-like compound fragrance and the citrus-like compound fragrance containing the test substances each have a sensory deodorizing effect on cat urine odor, and are considered to be highly useful as deodorizers for cat urine odor. [Industrial Applicability]

[0130] According to one aspect of the present invention, there is provided an inhibitor of cat urine odor receptors that is suitable for deodorizing cat urine odor by suppressing the response of cat urine odor receptors that exhibit specific responsiveness to cat urine odor. Another aspect of the present invention provides a method for searching for cat urine odor inhibitors, which allows comprehensive analysis of inhibitors of cat urine odor receptors.

Claims

1. A deodorizer for gaseous cat urine odor containing Limbe littoralis fruit oil.

2. an inhibitor that suppresses the response of at least one cat urine odor receptor selected from the group consisting of TAAR5 and polypeptides having a function equivalent to TAAR5; A cat urine odor receptor inhibitor containing Limbe littoralis fruit oil.

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