JP6836229B2 - Virus growth inhibitor - Google Patents

Description

The present invention relates to a viral growth inhibitor containing proanthocyanidins and teasinensins as active ingredients.

For the prevention and treatment of viral infections, the development of vaccines using antigen-antibody reactions is the mainstream, but due to the high mutation rate of viruses, emerging viruses and re-emerging viruses have appeared, and vaccine development has not been supported. Is the current situation. Examples of means other than the vaccine include enzyme inhibitors such as thymidine kinase inhibitors against herpes virus, reverse transcriptase inhibitors and protease inhibitors against human immunodeficiency virus, and neuraminidase inhibitors against influenza virus. However, the viruses to which these enzyme inhibitors can be applied are extremely limited.

On the other hand, polyphenol, which is a plant-derived component, has various physiological activities, and for viruses, it has an inactivating effect that deprives the infectivity by preventing adsorption to cells by directly contacting the virus, and virus infection. It is known to have the effect of inhibiting the growth of the virus after infection. For example, (-)-epigallocatechin-3-O-gallate, which is a kind of catechins, inhibits the growth of influenza virus (Patent Document 1), and proanthocyanidins derived from apples and grapes (polymers of catechins). ) Inhibits the growth of SARS coronavirus (Patent Document 2). In addition, peanut seed coat extract containing proanthocyanidins inhibits the growth of human immunodeficiency virus and SARS coronavirus (Patent Document 3), and epicatechin tetramer causes the growth of SARS coronavirus, cat calicivirus, and influenza virus. (Patent Document 4) and the like have been reported. However, it has not been reported that the binding of gallic acid to proanthocyanidins significantly improves the growth inhibitory activity against various viruses.

In addition, it has been reported that teasinencins (dimers of catechins different from proanthocyanidins) contained in oolong tea and black tea inactivate herpes simplex virus (Non-Patent Document 1), but the virus propagates. No inhibitory effect has been reported.

Japanese Unexamined Patent Publication No. 2011-126834 Japanese Patent Application Laid-Open No. 2005-314316 JP-A-2007-217410 JP-A-2015-214501

Antimicrob. Agents Chemother., 55, 5646-5653 (2011)

An object of the present invention is to provide a new virus growth inhibitor that is effective against various viruses and is highly effective against emerging viruses and re-emerging virus infections.

As a result of intensive studies to solve the above problems, the present inventors have surprisingly found that proanthocyanidins and teasinencins in which gallic acid is bound to proanthocyanidins have high viral growth inhibitory activity. We have found and completed the present invention.

That is, the present invention provides a virus growth inhibitor containing one or more selected from the proanthocyanidins represented by the formula (I) and the teasinencins represented by the formula (II) as active ingredients. It is a thing. It also provides foods and drinks, pharmaceuticals and quasi-drugs for inhibiting or reducing virus growth, including the virus growth inhibitor.

(R ₁ and R ₃ independently represent a hydrogen atom or a hydroxyl group. R ₂ and R ₄ represent a hydrogen atom or a galloyl group, _{and at least one of R 2} and R ₄ is a galloyl group.)

(R ₅ and R ₆ independently represent a hydrogen atom or a galloyl group)

The virus growth inhibitor of the present invention has high growth inhibitory activity against various viruses and is highly safe because it is a component contained in tea-derived polyphenols. In addition, since the virus growth inhibitor is a catechin dimer and a small molecule, it is easier to synthesize than other proanthocyanidins. In addition, the virus growth inhibitor of the present invention can be contained in pharmaceuticals, supplements, foods and drinks, etc., and by administering or ingesting these, virus growth can be suppressed and virus infection can be prevented or alleviated. You can expect it.

The present invention will be described in detail below.
The proanthocyanidin gallates represented by the formula (I), which are the active ingredients of the virus growth inhibitor of the present invention, are a kind of proanthocyanidins.
(R ₁ and R ₃ independently represent a hydrogen atom or a hydroxyl group. R ₂ and R ₄ represent a hydrogen atom or a galloyl group, _{and at least one of R 2} and R ₄ is a galloyl group.)

Proanthocyanidins are (+)-catechin [(+)-C], (+)-gallocatechin [(+)-GC], (-)-epicatechin [(-)-EC], (-)-epi Galocatechin [(-)-EGC], (-)-Epigallocatechin-3-O-gallate [(-)-ECg], (-)-Epigallocatechin-3-O-gallate [(-)-EGCg] It is known as a polymerized polyphenol in which a plurality of catechins such as catechins are bound as a constituent unit. Due to the difference in the binding mode, proanthocyanidins are type A (having 4 → 8 and 2 → O → 7 or 4 → 6 and 2 → O → 7 binding between the constituent units) and type B (composition). (Has a 4 → 8 or 4 → 6 bond between units). B-type proanthocyanidins are known to be contained in many plants such as tea, grape seeds, apples, pine bark, and cacao. From tea leaves, green tea, oolong tea, and black tea, the following formulas (III) to (V) ) B-type proanthocyanidins ( _{specific examples of R 1 to} R ₄ are listed below the formula) have been isolated.

The viral growth inhibitor of the present invention contains proanthocyanidin gallates represented by the formula (I) in which gallic acid is bound to dimers of type B proanthocyanidins as an active ingredient. The proanthocyanidin gallate represented by the formula (I) is preferably the proanthocyanidin gallate represented by the following formula (VI) from the viewpoint of high virus growth inhibitory activity. Specific examples of proanthocyanidin gallates represented by the formula (VI) include (-)-EC- (4β → 8)-(-)-ECg (procyanidin B2-3'-O-gallate), (-)-. ECg-(4β → 8)-(-)-ECg (procyanidin B2-3,3'-di-O-gallate), (-)-EGC-(4β → 8)-(-)-ECg, (-) -EGCg- (4β → 8)-(-)-ECg, (-)-EGC-(4β → 8)-(-)-EGCg (proanthocyanidin B2-3'-O-gallate), (-)-EGCg -(4β → 8)-(-)-EGCg (proanthocyanidin B2-3,3'-di-O-gallate), (-)-EC-(4β → 8)-(-)-EGCg, (+) -GC- (4α → 8)-(-)-EGCg (proanthocyanidin B4-3'-O-gallate), (+)-C-(4α → 8)-(-)-EGCg, (+)-GC -(4α → 8)-(-)-ECg and so on. Proanthocyanidins gallates can be produced by a known chemical synthesis method (for example, the method described in Molecules, 20, 18870-18885 (2015)). To give a specific example, (-)-EGC- (4β → 8)-(-)-EGCg introduced a leaving group into (-)-EGC protected with a benzyl group and protected with a benzyl group (-). )-Can be produced by condensing with EGCg and deprotecting.

(R ₁ and R ₃ independently represent a hydrogen atom or a hydroxyl group. R ₂ and R ₄ represent a hydrogen atom or a galloyl group, _{and at least one of R 2} and R ₄ is a galloyl group.)

In addition to tea (Camellia sinensis), proanthocyanidin gallates, which are the active ingredients of the virus growth inhibitor of the present invention, include tea (Camellia sinensis), mallotus japonicus (Rheum sp.), Bayberry (Morella rubra), European grape (Vitis vinifera), and tuber fleeceflower (Turdokudami). Polygonum multiflorum), Mallotus japonicus, etc. can also be extracted and purified. A crude product of proanthocyanidin gallates may be used as long as it conforms to pharmaceutically or food-acceptable standards and exhibits the effects of the present invention, and the purity is adjusted by appropriately combining known separation and purification methods. You may use the raised one. Examples of the purification means include a solvent extraction method using a polar solvent such as water, hot water, alcohol, or a non-polar solvent, a centrifugation method, a high-speed liquid chromatograph method, a column chromatograph method, and the like.

The virus growth inhibitor of the present invention can also contain teasinensins represented by the formula (II) as an active ingredient.

(R ₅ and R ₆ independently represent a hydrogen atom or a galloyl group.)

In the above formula, a letter B is added to a predetermined benzene ring for explanation, and it is shown that the benzene ring is a B ring.
Teacinencins are dimers in which catechins are bound to each other in the B ring, and are contained in oolong tea and black tea. Well-known teasinencins include teasinencin A, teasinencin B, teasinencin C, teasinencin D, and teasinencin E represented by the following formulas (VII) and (VIII).

"S" and "R" indicating the binding mode in the above formula represent S-form and R-form, respectively.

From the viewpoint of high virus growth inhibitory activity, teasinen singalates represented by the following formula (IX) are preferable. Examples of the teasinencin gallates represented by the formula (IX) include teasinencin A, teasinencin B, and teasinencin D. For tetrahedrons, a known chemical synthesis method (for example, the method described in JP-A-2010-138103, Chem. Pharm. Bull. 59, 1183-1185 (2011), etc.) or a method using pear fruit homogenate (Tetrahedron) , 59, 7939-7947 (2003)) and the like. For example, teacinencin A can be produced by oxidatively polymerizing (-)-EGCg together with a catalyst or an oxidase and then reducing it.

(R ₅ and R ₆ independently represent a hydrogen atom or a galloyl group)

Further, the teasinencins, which are the active ingredients of the viral growth inhibitor of the present invention, can also be obtained by extracting and purifying semi-fermented tea such as oolong tea and fermented tea such as black tea. A crudely purified product of teasinencins may be used as long as it conforms to pharmaceutically or food-acceptable standards and exhibits the effects of the present invention, and the purity has been increased by appropriately combining known separation and purification methods. You may use the thing. Examples of the purification means include a solvent extraction method using a polar solvent such as water, hot water, alcohol, or a non-polar solvent, a centrifugation method, a high-speed liquid chromatograph method, a column chromatograph method, and the like.

Examples of viruses for which the virus growth inhibitor of the present invention is effective include coronavirus (SARS coronavirus, MERS coronavirus, human coronavirus, etc.), calicivirus (cat calicivirus, nowalk virus, etc.), and influenza virus (influenza A). Examples include RNA viruses and DNA viruses such as viruses, influenza B virus, influenza C virus, etc.), human immunodeficiency virus, herpes virus, adenovirus, papillomavirus, rhinovirus, enterovirus, etc.

The mechanism by which the virus growth inhibitor of the present invention is effective is unknown, but since it is effective against various viruses, it is considered that it acts on the growth function common to viruses. Treatment of cells with proanthocyanidins induces manganese superoxide dismutase, which is thought to inhibit viral growth by suppressing the production of superoxide, which is required for viral growth (Biochem. Biophys. Res). . Commun., 261, 139-143 (1999), see Patent Document 3). It is considered that the virus growth inhibitor of the present invention also inhibits virus growth by the same mechanism.

Since proanthocyanidin gallates and teasinencins, which are the active ingredients of the virus growth inhibitor of the present invention, have an action of inhibiting virus growth in cells, a virus growth inhibitor containing these active ingredients is orally used. Alternatively, it can be administered parenterally to mammals including humans to prevent / treat viral infections and suppress viral production. Dosage forms for oral administration of viral growth inhibitors include tablets, granules, fine granules, pills, powders, capsules, troches, chewables, liquids (drinks) and the like. Further, a pharmaceutically acceptable carrier may be added to the active ingredient to prepare a preparation for external use. Examples of the form of the preparation include liquids, lotions, ointments, creams, gels, tapes, patches, aerosols, sprays, emulsions, etc., which act on the skin surface or mucous membranes. Any form may be used.

In addition, the virus growth inhibitor of the present invention can be contained in foods and drinks and ingested. The foods and drinks are not particularly limited, but the specific target foods and drinks are tea-based drinks, coffee drinks, carbonated drinks, fruit drinks, fruit liquors, vegetable drinks, soft drinks, dairy drinks, lactic acid bacteria drinks, and drinks. Beverages such as medicines, sports drinks and soy milk; desserts such as ice cream, ice milk, lacto ice, ice cream, yogurt, pudding and jelly; Confectionery such as pie, chocolate, chewing gum; Japanese-style soup, Western-style soup, Chinese soup, miso soup and other soups; Breads; Jams; Mayonnaise, dressing and other seasonings; Can be done. Furthermore, by including at least one or more of the virus growth inhibitor of the present invention in foods and drinks, the food can be made into a functional food for the purpose of inhibiting virus growth.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to this.

[Production Example 1] Preparation of proanthocyanidins Galates 100 g of polyphenone G (green tea extract powder, manufactured by Mitsui Norin Co., Ltd.) dissolved in 1.2 L of ultrapure water is placed on a DIAION HP20 column (70 mm x 310 mm, manufactured by Mitsubishi Chemical Corporation). Ultrapure water 1.8L, 20%, 40%, 60%, 80% methanol (water / methanol = 8/2, 6/4, 4/6, 2/8 (volume ratio)) aqueous solution 3L each, acetone It was eluted sequentially with 3 L. Each eluate was concentrated under reduced pressure and lyophilized to produce a water fraction of 46.02 g, a 20% methanol fraction of 16.97 g, a 40% methanol fraction of 20.28 g, a 60% methanol fraction of 14.25 g, and an 80% methanol fraction of 1.87 g. An acetone fraction of 0.50 g was obtained.

19.70 g of a 40% methanol fraction dissolved in 75 mL of methanol was fractionated with a TOYO PEARL HW-40C column (40 mm × 440 mm, manufactured by Tosoh Corporation) (mobile phase: methanol, flow rate 14.7 mL / min). Concentrate the eluate, freeze-dry it, and add 8.04 g of fraction 1 (holding time 0 to 60 minutes), 10.72 g of fraction 2 (60 to 150 minutes), and 0.53 g of fraction 3 (150 to 270 minutes). Obtained.

Fraction 3 of 0.52 g was fractionated by preparative HPLC using Mightysil RP-18 GP II (20 × 250 mm, particle size 5 μm, manufactured by Kanto Chemical Co., Inc.) (column temperature: 26 ° C., flow velocity: 16 mL / min, mobile phase A: water / formic acid = 1000/2 (volume ratio), mobile phase B: methanol, gradient program: 0 to 50 minutes mobile phase B increased to 10 to 30% by volume → 50 to 51 minutes Mobile phase B increased to 30-95% by volume → Mobile phase B was maintained at 95% by volume from 51 to 60 minutes). Concentrate and lyophilize the eluate, fraction 3-1 (holding time 0-12 minutes) 3 mg, fraction 3-2 (12-15 minutes) 64 mg, fraction 3-3 (15-19 minutes) ) 48 mg, fraction 3-4 (19-22 minutes) 21 mg, fraction 3-5 (22-27 minutes) 31 mg, fraction 3-6 (27-31 minutes) 35 mg, fraction 3-7 (31-54 minutes) 142 mg and fraction 3-8 (54-58 minutes) 14 mg were obtained.

63 mg fraction 3-2 was purified by preparative HPLC using Mightysil RP-18 GP II (20 x 250 mm, particle size 5 μm) (mobile phase: water / ethyl acetate / formic acid = 970/30/1 (volume ratio) ), Column temperature: 26 ° C, flow velocity: 16 mL / min), (-)-EGC- (4β → 8)-(-)-EGCg was added to 2 mg, and (+)-GC- (4α → 8)- 37 mg of (-)-EGCg was obtained.

Purification of 46 mg fraction 3-3 by preparative HPLC using Mightysil RP-18 GP II (20 × 250 mm, particle size 5 μm) (1st mobile phase: water / ethyl acetate / formic acid = 920/80) / 1 (volume ratio), column temperature: 26 ° C, flow rate: 16 mL / min. Second mobile phase: water / acetonitrile / formic acid = 920/80/1 (volume ratio), column temperature: 26 ° C, flow rate: 16 mL / min min) was performed to obtain 16 mg of (+)-GC- (4α → 8)-(-)-ECg.

Purification of 19 mg fraction 3-4 by preparative HPLC using Mightysil RP-18 GP II (20 x 250 mm, particle size 5 μm) (mobile phase: water / acetonitrile / formic acid = 910/90/2 (volume ratio)) , Column temperature: 26 ° C., flow velocity: 16 mL / min) to obtain 11 mg of (-)-EGCg- (4β → 8)-(-)-EGCg.

[Production Example 2] Preparation of (-)-EGC- (4β → 8)-(-)-EGC
Dissolve 8 mg of (-)-EGCg- (4β → 8)-(-)-EGCg in 1.5 mL of ultrapure water, add 2 mg of Sumiteam TAN (Tannase, manufactured by Shin Nihon Kagaku Kogyo Co., Ltd.), and add 2 mg at 37 ° C for 30 minutes. It was reacted. Then, the reaction solution was purified by preparative HPLC using Mightysil RP-18 GP II (20 x 250 mm, particle size 5 μm) (mobile phase: water / methanol / formic acid = 950/50/1 (volume ratio), column temperature. : 26 ° C., flow velocity: 16 mL / min) to obtain 5 mg of (-)-EGC- (4β → 8)-(-)-EGC.

[Production Example 3] Synthesis of teasinencin A
1.8 g of (-)-EGCg (manufactured by Mitsui Norin Co., Ltd.) was dissolved in 60 mL of ultrapure water and 60 mL of McIlvaine buffer (pH 5). To each of the four 50 mL conical beakers, 30 mL of this solution and 170 mg of 10% palladium / carbon (50% wet product, manufactured by SIGMA-ALDRICH) were added, and the mixture was stirred at room temperature for 180 minutes in an air atmosphere. After the catalyst was filtered off, 463 mg of dithiothreitol was added to the filtrate, and the mixture was stirred at room temperature for 45 minutes. A 1 M aqueous sodium hydroxide solution was added to the reaction solution to adjust the pH to 6. The reaction mixture was extracted 5 times with 50 mL of ethyl acetate, and the ethyl acetate layer was dehydrated with sodium sulfate. After the sodium sulfate was filtered off, the filtrate was concentrated to dryness with a rotary evaporator. After dissolving 1.5 g of the ethyl acetate fraction in 5 mL of methanol, it was subjected to TOYOPEARL HW-40S column chromatography (40 mm × 450 mm, mobile phase: methanol, flow rate: 15 mL / min) to obtain 374 mg of crude teasinencin A. The obtained crude teacinencin A was dissolved in 15 mL of 5% acetonitrile (water / acetonitrile = 9.5 / 5, volume ratio), and then MCIGEL-CHP55Y column chromatography (20 mm × 300 mm, manufactured by Mitsubishi Chemical Corporation, mobile phase: water / acetonitrile). Purification by / formic acid = 870/130/1 (volume ratio), flow velocity: 7.5 mL / min) gave 286 mg of acetonitrile.

[Production Example 4] Synthesis of teasinencin B
0.6 g of (-)-EGC (manufactured by Mitsui Norin Co., Ltd.) and 0.9 g of (-)-EGCg were dissolved with 60 mL of ultrapure water and 60 mL of McIlvaine buffer (pH 5). To each of the four 50 mL conical beakers, 30 mL of this solution and 250 mg of 10% palladium / carbon (50% water-wet product) were added, and the mixture was stirred at room temperature for 210 minutes in an air atmosphere. After the catalyst was filtered off, 860 mg of tris (2-carboxyethyl) phosphine hydrochloride was added to the filtrate, and the mixture was stirred at room temperature for 10 minutes. The reaction solution was directly subjected to DIAION HP-20 column chromatography (30 mm × 140 mm), washed with 350 mL of ultrapure water, and eluted with 500 mL of 40% methanol (water / methanol = 6/4, volume ratio). After dissolving 1.1 g of the concentrated and dried 40% methanol fraction in 5 mL of methanol, it was subjected to TOYOPEARL HW-40S column chromatography (40 mm × 450 mm, mobile phase: methanol, flow rate: 15 mL / min) to obtain 294 mg of crude teasinencin B. It was. After dissolving the obtained crude teacinencin B in 7.5 mL of 5% acetonitrile (water / acetonitrile = 9.5 / 5, volume ratio), MCIGEL-CHP55Y column chromatography (20 mm × 300 mm, mobile phase: water / acetonitrile / formic acid = 900 / Purification was carried out at 100/1 (volume ratio), flow velocity: 7.5 mL / min) to obtain 188 mg of acetonitrile.

[Production Example 5] Synthesis of teasinencin C
1.2 g of (-)-EGC was dissolved in 60 mL of ultrapure water and 60 mL of McIlvaine buffer (pH 5). 30 mL of this solution and 170 mg of 10% palladium / carbon (50% wet product) were added to each of four 50 mL conical beakers, and the mixture was stirred at room temperature for 240 minutes in an air atmosphere. After the catalyst was filtered off, 860 mg of tris (2-carboxyethyl) phosphine hydrochloride was added to the filtrate, and the mixture was stirred at room temperature for 10 minutes. The reaction mixture was purified by MCIGEL-CHP55Y column chromatography (20 mm × 300 mm, mobile phase: water / methanol / formic acid = 950/50/1 (volume ratio), flow velocity: 7.5 mL / min) to obtain 369 mg of teacinencin C. It was.

[Test Example 1] Measurement of growth inhibitory activity against SARS coronavirus The growth inhibitory activity of the fractions, proanthocyanidins, and teacinencins obtained in Production Examples 1 to 5 against SARS coronavirus was measured. The activity of catechins ((-)-EC, (-)-EGC, (-)-ECg, (-)-EGCg, all manufactured by Mitsui Norin Co., Ltd.) was also measured. For SARS coronavirus, FFM-1 strain (distributed from Dr. HW Doerr, Frankfurt University of Medicine, Germany) was used. Vero cells (derived from African green monkey kidney) were used as the cultured cells, and 10 wt% fetal bovine serum, streptomycin (100 μg / mL), and penicillin (100 U / mL) were added to the medium, and Dalveco's modified Eagle's minimum essential medium (SIGMA-). The cells were cultured at 37 ° C. in the presence _{of CO 2 at a} concentration of 5% by volume using ALDRICH).

Vero cells forming a 90% monolayer on a 6-well plate were infected with 0.2 mL of SARS coronavirus stock solution at 25 ° C. for 60 minutes. Then, the test substance was added so as to be 0, 1, 3, 10, 30, 100 μg / mL (0, 10, 30, 100, 200, 400 μg / mL only in the case of polyphenone G) per 1 mL of the culture medium, and 1 weight was added. The cells were cultured in Dalveco's modified Eagle's minimum essential medium (containing 5% fetal bovine serum) containing% methylcellulose for 4 days. After culturing, methylcellulose was removed, Vero cells were stained with 2.5 wt% crystal violet, ^{and 3 times with 0.05M phosphate buffered saline (Mg 2+} and Ca ²⁺ free, 0.15M sodium chloride, pH 7.0). Washed. From the number of plaques formed, the amount of virus per 1 mL was calculated as PFU (Plaque Forming Unit) / mL, and the IC ₅₀ (concentration that inhibits virus growth by 50% (calculated from the number of inhibition)) of the test substance was calculated. It is shown in Table 1 and Table 2.

The growth-inhibiting component of SARS coronavirus contained in polyphenone G, which is a green tea extract powder, was identified (see Production Example 1 for the preparation method). Using DIAION HP20, polyphenone G (IC ₅₀ = 150 μg / mL) was fractionated into 6 fractions (water fraction, 20%, 40%, 60%, 80% methanol fraction, acetone fraction). _{Next, the 40% methanol fraction (IC 50} = 25 μg / mL), which had the highest growth inhibitory activity against SARS coronavirus, was fractionated into three fractions (fractions 1 to 3) with TOYOPEARL HW-40C. Next, fraction 3 (IC ₅₀ = 15 μg / mL) with the highest growth inhibitory activity was subjected to preparative HPLC using Mightysil RP-18 GP II, and 8 fractions (fractions 3-1 to 3-8). ). In addition, three fractions with high growth inhibitory activity, fraction 3-2 (IC ₅₀ = 20 μg / mL), fraction 3-3 (IC ₅₀ = 20 μg / mL), fraction 3-4 (IC ₅₀ = 15 μg) / mL) was purified by the same preparative HPLC. From fraction 3-2 (-)-EGC- (4β → 8)-(-)-EGCg and (+)-GC-(4α → 8)-(-)-EGCg from fraction 3-3 ( +)-GC-(4α → 8)-(-)-ECg was obtained from fractions 3-4, and (-)-EGCg-(4β → 8)-(-)-EGCg was obtained.

These isolated compounds were proanthocyanidin gallates in which gallic acid was bound to a dimer of proanthocyanidins. The growth-inhibitory activity of proanthocyanidins against SARS coronavirus was compared with the activity of monomeric catechins and dimers of oolong tea and black tea with different binding modes (Table 2). ..

As shown in Table 2, among the monomeric catechins, IC ₅₀ exceeded 100 μg / mL in (-)-EC and (-)-EGC, and no growth inhibitory activity against SARS coronavirus was observed. .. Among the monomeric catechins, (-)-ECg and (-)-EGCg, which have a galloyl group, have a virus growth inhibition rate lower than 50% at a test concentration of 1 to 30 μg / mL, and 100 μg / _{IC 50} could not be calculated because cell degeneration was observed in mL.

On the other hand, dimers of proanthocyanidins and teacinencins were found to have a growth inhibitory activity against SARS coronavirus, and proanthocyanidins having a galloyl group and teasinensingarates were particularly highly active in inhibiting growth. Proanthocyanidins ((-)-EGC-(4β → 8)-(-)-(-)-EGC- (4β → 8)-(-)-EGC, which are proanthocyanidins without galloyl group -EGCg, (+)-GC-(4α → 8)-(-)-EGCg, (+)-GC-(4α → 8)-(-)-ECg, (-)-EGCg-(4β → 8) -(-)-EGCg) was found to be 2.5 to 3.3 times more active. In addition, the activity of teasinencin gallates (teacinencin A and teasinencin B) was 3.3 to 5.0 times higher than that of teasinencin C, which is a teasinencin having no galloyl group.

[Test Example 2] Measurement of growth inhibitory activity against feline calicivirus Measurement of growth inhibitory activity of proanthocyanidins gallates (+)-GC- (4α → 8)-(-)-EGCg and teacinencins against feline calicivirus Was done. _{The IC 50} of the test substance against feline calicivirus was calculated by the same method as in Test Example 1 except that feline calicivirus F9 strain was used instead of SARS coronavirus and CRFK cells (derived from cat kidney) were used instead of Vero cells. ..

A proanthocyanidin gallate compound (+) - GC- (4α → 8) - (-) - IC 50 of EGCg is 30 [mu] g / mL, Teashinenshin A, Teashinenshin B and Teashinenshin C IC ₅₀ of each 20μg / mL, 10μg / It was mL, 70 μg / mL. Compared to teasinencin C, which does not have a galloyl group, (+)-GC- (4α → 8)-(-)-EGCg, teacinencin A and teacinencin B, which have a galloyl group, show 2.3 to 7.0 times stronger viral growth inhibitory activity. Was done.

[Test Example 3] Measurement of growth inhibitory activity against influenza virus The growth inhibitory activity of proanthocyanidin gallates (+)-GC- (4α → 8)-(-)-EGCg against influenza virus was measured. _{IC 50} of the test substance against influenza virus was calculated by the same method as in Test Example 1 except that influenza A virus PR8 strain was used instead of SARS coronavirus and MDCK cells (derived from canine kidney) were used instead of Vero cells. .. _{The IC 50} of (+)-GC-(4α → 8)-(-)-EGCg was 10 μg / mL.

[Formulation example] Chewable tablets
(+)-GC-(4α → 8)-(-)-EGCg 0.5 parts by weight, xylitol 33.8 parts by weight, mannitol 30.6 parts by weight, microcrystalline cellulose 6.1 parts by weight, flavoring 14.1 parts by weight, stearate 4.3 parts by weight A powder obtained by mixing parts, 0.6 parts by weight of talc and 10.0 parts by weight of sorbitol was compressed by a tablet press to obtain tablets containing a virus growth inhibitor.

The virus growth inhibitor of the present invention is useful for the prevention and treatment of viral infections.

Claims (4)

A virus growth inhibitor against coronavirus or calicivirus, which contains one or more selected from proanthocyanidins gallates represented by the formula (I) and teasinensins represented by the formula (II) as active ingredients.

(R ₁ and R ₃ independently represent a hydrogen atom or a hydroxyl group, _{and at least one of R 1} and R ₃ is a hydroxyl group. R ₂ and R ₄ represent a hydrogen atom or a galloyl group, and R ₂ and R _At least one of 4 is a galloyl group.)


(R ₅ and R ₆ independently represent a hydrogen atom or a galloyl group, respectively.) The virus growth inhibitor according to claim 1, wherein the active ingredient of the virus growth inhibitor is the teasinencins represented by the formula (II). A food or drink for inhibiting the growth of coronavirus or calicivirus , which comprises the virus growth inhibitor according to claim 1 or 2. A drug or quasi-drug for inhibiting the growth of coronavirus or feline calicivirus , which comprises the virus growth inhibitor according to claim 1 or 2.