JP7840657B2 - Virus inactivator - Google Patents

Description

This invention relates to a virus inactivator that inactivates viruses.

Viral infections, ranging from common cold symptoms to serious conditions such as pneumonia, hepatitis, and encephalitis, remain a perpetual threat to humanity. In recent years, influenza viruses have ravaged the world, sometimes leading to pandemics due to the emergence of novel influenza strains with altered antigenicity. Furthermore, in 2019, SARS-CoV-2 emerged, causing a pandemic that impacted not only life and health but also economic activity and social functions.

To address situations like this, vaccines and antiviral drugs are being developed, but the development of vaccines and treatments takes time and is not always successful.
Viruses spread when they are brought into living spaces by infected individuals, either directly from the patient or through the environment, including clothing, various utensils and materials, walls, air conditioners, and other equipment. Therefore, it is considered effective in preventing the spread of infection by washing and disinfecting hands, clothing, and various utensils and materials that may come into contact with the virus, thereby eliminating or inactivating the virus, as well as inactivating viruses that have been airborne in droplets and viruses that float in the air as aerosols.

Traditionally, ethanol, sodium hypochlorite, chlorine dioxide, and glutaraldehyde have been used to inactivate viruses. However, these common disinfectants are highly irritating to mucous membranes and skin, limiting their use due to safety concerns. Furthermore, while spraying chlorine dioxide has been considered as a method to chemically inactivate viruses in the air, its effectiveness is not yet confirmed.

Essential oils and the aromatic components they contain are used as fragrances in a variety of products, including cosmetics, but it is also well known that some essential oils and fragrance compounds exhibit specific physiological effects. For example, there are many essential oils and fragrance compounds that have antiviral activity against viruses (see, for example, Patent Document 1, Non-Patent Document 1, Non-Patent Document 2).
Furthermore, it has been reported that combining citral with a specific aldehyde as a composition to suppress the growth of microorganisms can suppress the growth of fungi under gas-phase reaction conditions (Patent Document 2). However, it is not clear whether such a composition suppresses the growth of viruses that infect and proliferate in cells, or inactivates the viruses themselves, and it is completely unknown whether each compound alone has a virus-inactivating effect.

Japanese Patent Application Publication No. 5-306217 Japanese Patent Publication No. 2017-206466

Swamy et al., Evid Based Complement Alternat Med. 2016:3012462. Hayashi K, et al., Planta Medica, 01 Jun 1995, 61(3):237-241

This invention relates to providing a virus inactivator that enables the inactivation of viruses present in the environment.

The inventors of this invention have discovered that certain fragrance compounds have the effect of inactivating influenza viruses, and that these compounds are useful as virus inactivators.

In other words, the present invention relates to the following 1) to 2).
1) A virus inactivator comprising one or more compounds selected from benzaldehyde, hydroxycitronellal, nonanal, and decanal as an active ingredient.
2) A method for inactivating viruses, comprising applying one or more compounds selected from benzaldehyde, hydroxycitronellal, nonanal, and decanal, or a composition containing the same, to an object suspected of being contaminated with a virus.

The virus inactivating agent of the present invention can inactivate viruses attached to hard and soft surfaces in the living environment, viruses dispersed in living spaces as droplets, and viruses floating in the air as aerosols, thereby preventing or reducing the spread of infection caused by these viruses.

Influenza virus inactivation effect (gas phase). Influenza virus inactivation effect (liquid phase).

The benzaldehyde, hydroxycitronellal, nonanal, and decanal (hereinafter also referred to as "the compounds of the present invention") of the present invention are all compounds used as fragrances and are commercially available as follows.
- Benzaldehyde: Tokyo Chemical Industries, Ltd., Fujifilm Wako Pure Chemical Industries, Ltd. - Hydroxycitronellal (also known as 7-hydroxy-3,7-dimethyloctanal): Fujifilm Wako Pure Chemical Industries, Ltd. - Nonanal (also known as pelargonaldehyde): Tokyo Chemical Industries, Ltd., Fujifilm Wako Pure Chemical Industries, Ltd. - Decanal (also known as caprinaldehyde): Tokyo Chemical Industries, Ltd.

Such compounds may be used individually or in mixtures of two or more.

Among the compounds of the present invention, preferred candidates include benzaldehyde and nonanal from the viewpoint of virus inactivation effect, hydroxycitronellal from the viewpoint of aroma intensity, quality, and volatility, and benzaldehyde, hydroxycitronellal, and nonanal from the viewpoint of overall suitability.

The compound of the present invention can be used in both liquid and gas phases, but from the viewpoint of virus inactivation effect, it is preferable to use it in the gas phase.

The viruses targeted by the virus inactivator of the present invention include all types of viruses, regardless of the type of nucleic acid (RNA, DNA) and whether or not they have an envelope.
Enveloped viruses include those with RNA as their nucleic acid, such as influenza virus, coronavirus, SARS coronavirus, SARS coronavirus-2, RSV, mumps virus, lassa virus, dengue virus, rubella virus, and human immunodeficiency virus, and those with DNA as their nucleic acid, such as human herpesvirus, vaccinia virus, and hepatitis B virus.
Furthermore, examples of viruses that do not have an envelope include those with RNA as their nucleic acid, such as norovirus, poliovirus, echovirus, hepatitis A virus, hepatitis E virus, rhinovirus, astrovirus, rotavirus, coxsackievirus, enterovirus, and sapovirus, and those with DNA as their nucleic acid, such as adenovirus, B19 virus, papovavirus, and human papillomavirus.

Of these, viruses having an envelope are preferred, viruses having an envelope and RNA as their nucleic acid are more preferred, and influenza virus, human coronavirus, SARS coronavirus, and SARS coronavirus-2 are even more preferred.
SARS-CoV-2 (Severe acute respiratory syndrome coronavirus 2) is a SARS-related coronavirus that causes acute respiratory illness (COVID-19).

In the present invention, virus inactivation means reducing or eliminating the activity of the virus and thereby eliminating its ability to infect host cells.
The virus inactivation effect can be confirmed, for example, by bringing the test product into contact with the virus, infecting host cells with the virus, and measuring the viral infectivity titer. Here, the host cell can be any cell in which the target virus can proliferate. For influenza virus, for example, canine kidney cells (MDCK), African green monkey kidney epithelial cells (Vero), or duck embryonic stem cell-derived cell lines (EB66) can be used. For human coronavirus, for example, human ileocecal adenocarcinoma cells (HCT-8), African green monkey kidney epithelial cells (VeroE6), or human liver cancer-derived cell lines (Huh7) can be used.

As shown in the examples described later, when the compound of the present invention, soaked into a cotton ball, is placed in a glass bottle and filled to capacity, and then dried influenza virus is added, and the compound and virus are brought into contact in the gas phase at room temperature, the viral infectivity titer decreases by 84% or more.
Therefore, the compounds of the present invention can serve as virus inactivators, preferably virus inactivators that inactivate viruses in the gas phase. Alternatively, the compounds of the present invention can be used to produce virus inactivators, preferably virus inactivators that inactivate viruses in the gas phase.
Furthermore, the compounds of the present invention can be used to inactivate viruses, preferably in the gas phase.

The virus inactivating agent of the present invention may be used in the form of the compound of the present invention used alone, or it may be in the form of a composition containing it (for example, an antiviral composition, a sanitary product composition, etc.). That is, the virus inactivating agent of the present invention can be an antiviral composition that exhibits a virus inactivating effect, a sanitary product composition that exhibits an antiviral effect, or a material or formulation for incorporating them.

The above antiviral compositions include those used in liquid or gas phase. Antiviral compositions used in liquid phase may contain, in addition to the compounds of the present invention, antimicrobial substances such as hypochlorous acid, hydrogen peroxide, silver ion compounds, cationic antimicrobial agents (such as benzethonium chloride), bactericides (such as triclosan and isopropylmethylphenol), ethanol, surfactants, etc., and are prepared by appropriately blending additives such as chelating agents, humectants, lubricants, builders, buffers, abrasives, electrolytes, bleaches, fragrances, dyes, foaming control agents, corrosion inhibitors, essential oils, thickeners, pigments, gloss enhancers, enzymes, detergents, solvents, dispersants, polymers, silicones, and hydrophobic substances. The form of such compositions may be, but is not limited to, liquid, emulsion, cream, lotion, paste, gel, sheet (supported on a substrate), or oil.
This antiviral composition can be appropriately incorporated into various cleaning agents (laundry detergents, household cleaning agents, dishwashing detergents, hair washes, hand washes, body washes, etc.), disinfectants, etc.

Antiviral compositions used in the gas phase (for example, compositions for deviralizing spaces) may be in liquid or gel form, but are preferably liquid. Such compositions can be prepared by blending the compound of the present invention with a base material and various additives (polyols (dipropylene glycol, propylene glycol, etc.), surfactants, ultraviolet absorbers, antioxidants, preservatives, deodorants, natural extracts, silicones, thickeners, dyes, pigments, colorants, oils, fragrances, etc.). Here, examples of conventionally known base materials, whether oily or aqueous, include water, methanol, ethanol, propanol, isopropanol, butanol, isobutanol, dimethyl ether, liquid propane, petrolatum, lanolin, castor oil, and paraffinic hydrocarbons (for example, liquid paraffin, etc.), which can be used alone or in combination of two or more.
Furthermore, when preparing a gel-like formulation, it can be prepared by appropriately adding a natural or synthetic gelling agent, such as a water-soluble gelling agent like carrageenan or gellan gum, or an oil-soluble gelling agent like metal soap or aluminum octylate, according to conventionally known methods.

Examples of the above-mentioned sanitary product compositions include lotions, creams, shampoos, hair conditioners, hand soaps, body washes, facial cleansers, bath additives, foams, antiperspirants, deodorants, underarm odor preventatives, and oral hygiene products (mouthwash, toothpaste, mouth fresheners, gargles, etc.).
The composition can be prepared by conventional methods by appropriately combining carriers that are acceptable as cosmetics, etc. (for example, diluents, dispersants, buffers, pH adjusters, emulsifiers, surfactants, preservatives, stabilizers, antioxidants, colorants, humectants, thickeners, disinfectants, fragrances, etc.).

The content of the active ingredient in the embodiment in which the virus inactivating agent of the present invention is used as a composition can be appropriately determined depending on the form of the composition. For example, the content of the compound of the present invention relative to the total amount of the composition is preferably 0.001% by mass or more, more preferably 0.01% by mass or more, and even more preferably 0.1% by mass or more. Furthermore, it is preferably 99.999% by mass or less, more preferably 50% by mass or less, and even more preferably 10% by mass or less. Also, it is preferably 0.001 to 99.999% by mass, more preferably 0.01 to 50% by mass, and even more preferably 0.1 to 10% by mass.

The virus inactivating agent of the present invention makes it possible to inactivate viruses attached to the skin or mucous membranes of animals contaminated with viruses, or to hard or soft surfaces of inanimate objects, as well as to inactivate viruses that have been airborne in living spaces. Examples of inanimate object surfaces include hard surfaces such as counters, sinks, restrooms, toilets, bathtubs, showers, floors, windows, doorknobs, walls, drains, and pipes in homes and business facilities; hard surfaces of various appliances, tools, and miscellaneous goods such as kitchenware, furniture, telephones, and toys; and soft surfaces of textile products (carpets, area rugs, curtains, fabric furniture, clothing, etc.). Living spaces include general households (dining rooms, kitchens, bedrooms, children's rooms, bathrooms, toilets, etc.), retail stores, restaurants, inns, hospitals, workshops, factories, etc., vehicles such as automobiles, trains, and aircraft, and semi-enclosed spaces (lockers, storage rooms, closets, etc.).

In the virus inactivating agent of the present invention, the compound of the present invention or a composition containing the same is applied to an object where viral contamination is a concern, but the embodiment is not particularly limited, and the compound of the present invention may be brought into contact with or reacted with the virus in the gas phase or liquid phase. Methods for bringing the compound of the present invention into contact with the virus in the liquid phase include directly applying the compound of the present invention or a composition containing the same to the object to be treated, diffusing the compound of the present invention or a composition containing the same and sprinkling it on the object to be treated, or wiping the surface of the object with a sheet, gauze, towel, wet wipe, tissue, wet wipe, etc., impregnated with the compound of the present invention or a composition containing the same.
Furthermore, by filling the compound of the present invention or a composition containing the same into a container or device for atomization or diffusion, such as a pressurized liquid spray, pressurized air atomizer, diffuser, or nebulizer, and spraying it in a mist-like manner into a space where viruses are present, the volatilization rate can be accelerated, and the virus inactivation effect can be rapidly exerted. Similar effects can also be obtained by using the compound of the present invention or a composition containing the same in the form of an aerosol or mist spray.

The method for contacting or reacting the compound of the present invention or a composition containing the same with a virus in the gas phase may be either by allowing the compound to volatilize naturally or by forcing its volatilization. While natural volatilization allows for the inactivation of viruses in a living space simply by leaving it there, thus easily removing viruses from the space, for the compound of the present invention, forced volatilization is preferable to increase the spatial concentration.
When the virus inactivator of the present invention is used for the purpose of natural volatilization, conventionally known methods such as impregnating a core rod, filter paper, etc. with the compound of the present invention or a composition containing it and volatilizing it, or volatilizing it using a permeable membrane can be applied. Alternatively, the compound of the present invention or a composition containing it can be kneaded into a resin and used. Examples of resins that can be kneaded include natural, petroleum, and synthetic waxes, rosin resins, ethylene-vinyl acetate copolymers, ethylene-vinyl alcohol copolymers, polyesters, polyolefins, and acrylic resins. The kneaded material can be used as is, or it can be supported on a porous carrier, made into a sheet, or used as a laminate of the sheet. Examples of porous carriers include natural polymers such as cellulose and chitosan, the synthetic resins mentioned above, and inorganic porous materials such as calcium silicate, which can be made into granules, sheets, or any other shape. The kneaded material or laminate can be used, for example, by installing it in air conditioning equipment, toilets, bathrooms, living rooms, hospital rooms, hospital waiting rooms, dustbins, etc., and allowing the compound of the present invention to volatilize gradually. Furthermore, the compound of the present invention or a composition containing the same can be used by supporting it on a product made of paper, nonwoven fabric, or the like (such as an air purifier filter).
When the compound of the present invention is used by forced volatilization, such means include, for example, a method of volatilization using a fan, a heating volatilization method using a heater, and a method of volatilization using ultrasound.

When performing airborne virus removal treatment, the amount of the compound of the present invention or a composition containing it used can be appropriately adjusted depending on the treatment method, the ambient environment such as temperature and humidity, the vapor pressure of each compound, etc. It is also possible to use an amount greater than or equal to the saturation concentration of each compound in the space. For example, the concentration of the compound of the present invention in the target space is 0.1% or more, preferably 1% or more, more preferably 5% or more, even more preferably 10% or more, and preferably 10% or less of the saturation concentration of the compound in the space, and is used so that it volatilizes at 100% or less, more preferably 50% or less, and more preferably 25% or less.
The concentration of the compound of the present invention in a target space can be detected by measuring the concentration of the compound in a gas sample taken from the space. This can be done using a volatile organic compound concentration meter (VOC meter, odor sensor, etc.), or by using gas chromatography or gas chromatography/mass spectrometry in combination with a gas collection tube.

With regard to the embodiments described above, the present invention further discloses the following embodiments.
<1> A virus inactivator comprising one or more compounds selected from benzaldehyde, hydroxycitronellal, nonanal, and decanal as an active ingredient.
<2> Use of one or more compounds selected from benzaldehyde, hydroxycitronellal, nonanal, and decanal to produce a virus inactivating agent.
<3> Use of one or more compounds selected from benzaldehyde, hydroxycitronellal, nonanal, and decanal, or a composition containing the same, for inactivating the virus.
<4> A method for inactivating viruses, comprising applying one or more compounds selected from benzaldehyde, hydroxycitronellal, nonanal, and decanal, or a composition containing the same, to an object suspected of being contaminated with a virus.
In <5>, <1> to <4>, the virus is preferably an enveloped RNA virus.
In <6>, <1> to <4>, the virus is preferably an influenza virus or a coronavirus.
In <7>, <1> to <6>, the inactivation of the virus is preferably performed in the gas phase.
In <8>, <1> to <7>, the content of the compound in the composition containing the compound relative to the total amount of the composition is preferably 0.001% by mass or more, more preferably 0.01% by mass or more, even more preferably 0.1% by mass or more, and preferably 99.999% by mass or less, more preferably 50% by mass or less, even more preferably 10% by mass or less, or preferably 0.001 to 99.999% by mass, more preferably 0.01 to 50% by mass, even more preferably 0.1 to 10% by mass.
<9> The method of <4>, wherein the compound or a composition containing the same is used such that the concentration of the compound in the target space is 0.05 ppmv or more, preferably 0.5 ppmv or more, more preferably 5 ppmv or more, and even more preferably 50 ppmv or more, and preferably below the saturation concentration of each compound in the space, more preferably 1000 ppmv or less, and more preferably 100 ppmv or less.

The present invention will be described in more detail below with reference to examples.
Example 1 Inactivation of influenza virus in the gas phase by fragrance compounds 1. Method Influenza virus type A (A/Puerto Rico/8/1934, H1N1) strain was used as the test virus strain. 75 μL of the compounds or mineral oil shown in Table 1 below was soaked into a cotton ball and attached to the lid of a 15 mL glass bottle (Maruemu Co., Ltd.) with double-sided tape to seal it, and it was filled for 30 minutes. 1.5 μL of influenza virus (8.3 × ^10⁵ FFU) was dried on the lid of a cryovial (Thermo Fisher Scientific) for 30 minutes. The lid of the vial with the virus attached was placed in the glass bottle, and the compound and virus were reacted at room temperature (approximately 23°C) for 30 minutes. During this time, the compound was placed on the lid of the bottle, and the virus was placed at the bottom of the bottle, maintaining a state where the compound and virus did not come into direct contact. After the reaction, the virus was recovered in Hybridoma-SFM medium (Thermo Fisher Scientific) and inoculated into MDCK cells (derived from canine renal tubular epithelial cells) that had been pre-cultured in 12-well plates. After incubation at 37°C under 5% _CO2 conditions for approximately 18 hours, the number of foci formed was measured to determine the viral infectivity titer. The infectivity titer when reacted with the control mineral oil was set to 100%, and the viral inactivation activity of each compound was calculated. The test was performed three times.

2. Results As shown in Figure 1, compared to the control mineral oil, compounds 1 to 4 reduced the detectable viral load to 0.001%, 5.67%, 0.24%, and 15.73%, respectively.

Example 2 Inactivation of influenza virus in liquid phase with fragrance compounds 1. Method Influenza virus type A (A/Puerto Rico/8/1934, H1N1) strain was used as the test virus strain. The compounds shown in Table 1 were dissolved in Hybridoma-SFM medium (Thermo Fisher Scientific) containing 1% (v/v) dipropylene glycol as a solvent so that the final concentration when reacting with the virus was 0.1% (v/v). 60 μL each of the compound solution or the 1% (v/v) dipropylene glycol solution and the influenza virus solution (8.3 × ^10⁵ FFU) with the medium as the solvent were added to a 96-well plate and reacted at room temperature (approximately 23°C) for 30 minutes. After the reaction, the virus was diluted with culture medium and inoculated into MDCK cells (derived from canine renal tubular epithelial cells) that had been pre-cultured in 48-well plates. After culturing at 37°C under 5% _CO2 conditions for approximately 18 hours, the number of foci formed was measured to determine the viral infectivity titer. The infectivity titer when reacted with a control 1% (v/v) dipropylene glycol solution was set as 100%, and the viral infectivity titer of each compound was calculated. The test was performed three times.

2. Results As shown in Figure 2, compared to the control 1% dipropylene glycol solution, compounds 1 to 4 reduced the detectable viral load to 65.1%, 51.9%, 56.4%, and 30.4%, respectively.

Claims (3)

A virus inactivator comprising one or more compounds selected from benzaldehyde, hydroxycitronellal, nonanal, and decanal as active ingredients, wherein the virus is the influenza virus. A virus inactivator according to claim 1, which inactivates viruses in the gas phase. A method for inactivating a virus, wherein the virus is an influenza virus, and the method involves applying one or more compounds selected from benzaldehyde, hydroxycitronellal, nonanal, and decanal, or a composition containing the same, to an object (excluding humans) suspected of being contaminated with a virus.