JPH0459731A - Antiviral agent - Google Patents

Abstract

PURPOSE:To obtain an antiviral agent having a wide range of spectrum against various kinds of viruses, inhibitory activity and excellent stability, comprising an imidazole nucleoside derivative or a salt thereof as an active ingredient. CONSTITUTION:A compound shown by the formula (R<1> is H or hydroxy lower alkyl; R<2> to R<4> are H, OH-protecting group or phosphate residue) such as 5- ethynyl-1-beta-D-ribofuranosylimidazole-4-carboxamide as an active ingredient. The compound strongly suppresses cell degeneration effects by various kinds of viruses, has low cell toxicity and high safety and a dose thereof is usually 0.02-2g per adult daily.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an antiviral agent containing a specific imidazole nucleoside derivative as an active ingredient.

[Prior Art] Many nucleoside derivatives are known as antiviral chemotherapeutic agents. For example, idoxuridine (ICU
), Vidarabine (AraA), Acyclovir (ACV),
Acidothymidine (AIT) and the like are used to treat certain viral diseases, but there are problems such as the target diseases are limited and the efficacy is not sufficient. Ribavirin is known as a compound that exhibits a broad range of potent antiviral effects against DNA and RNA viruses [Ann, New Work Acad, Sci.
,, 284.

272-292 (1977)], but there are not enough anti-antiviral agents and there are concerns about safety.

[111i1 to be solved by the invention] As mentioned above, various antiviral nucleoside derivatives have already been developed and put to use, but ribavirin is the only compound that has strong antiviral effects against a wide range of viruses. However, there was a need for a compound that was known to act more strongly against a wider range of viruses and was highly safe.

[Means for Solving Problem 11] Under the above-mentioned circumstances, the inventors of the present invention have conducted various studies in order to obtain a useful antiviral agent. We have discovered that a specific imidazole nucleoside derivative that has the above-mentioned properties satisfies the above requirements, has a broad spectrum and strong inhibitory activity against various viruses, and is also excellent in safety, and after further research, we completed the present invention. did.

That is, the present invention represents the following - killing [1] alkyl group, R, R and R4 each represent a hydrogen atom, a hydroxyl group protecting group or a phosphoric acid residue, and R, R3
and [4 may be the same or different. ] An antiviral agent containing an imidazole nucleoside derivative or a salt thereof as an active ingredient is provided.

In the general formula [I], when R1 is a hydroxy lower alkyl group, R1 is a linear or branched alkyl group having any number of carbon atoms of 10 or less, preferably 4 or less. It is a hydroxy lower alkyl group having several water groups.

Specifically, hydroxymethyl, α-hydroxyethyl, β-hydroxyethyl, α, β-dihydroxyethyl, α-hydroxypropyl, β-hydroxypropyl, γ
-Hydroxypropyl, α,β-dihydroxypropyl, α,γ-dihydroxypropyl, β,T-dihydroxypropyl, α-hydroxymethylethyl, β-hydroxymethylethyl, α,β-dihydroxymethylethyl,
α-hydroxybutyl, β-hydroxybutyl, γ-hydroxybutyl, δ~hydroxybutyl, α, β-dihydroxybutyl, α, γ-dihydroxybutyl, α, δ
-dihydroxybutyl, α.

1 to 411 carbon atoms such as β, γ-trihydroxybutyl, β, γ, δ-trihydroxybutyl! ! An example is a hydroxy lower alkyl group in which a human Oxyl group is substituted at any position of the alkyl group.

When R2R3 and/or R4 are hydroxyl-protecting groups, these are substituents commonly used as hydroxyl-protecting groups of nucleosides, and the two groups are the same or different. Specifically, acetyl, chloroacetyl, dichloroacetyl, trinoroacetyl, methoxy 7-cetyl, propionyl, n-butyryl, (E)-
2-methyl-2-butenoyl, isobutyryl, pentanoyl, benzoyl, 0-(dibromomethyl)benzoyl,
0-(methoxycarbonyl, p-phenylbenzoyl, 2.4.6-drimethylbenzoyl, p-t-luoyl, p-anisoyl, p-
Acyl groups such as chlorobenzoyl, p-nitrobenzoyl, α-naphthoyl; alkyloxymethyl groups such as methoxymethyl, ethoxymethyl, n-propoxymethyl; substituted ethyl groups such as 1-ethoxyethyl and 1-methyl-1-methoxyethyl Groups: benzyl, phenethyl, 3-phenylpropyl, p-methoxybenzyl, p-nitrobenzyl, p-herobenzyl, p-cyanobenzyl, diphenylmethyl, triphenylmethyl, α- or β-naphthylmethyl, α-naphthyldiphenylmethyl Aralkyl groups such as tetrahydrobilan-2-yl, 4-methoxytetrahydrobilan-4-yl; pyranyl groups such as trimethylsilyl, triethylsilyl, dimethylimpropylsilyl, isopropyldimethylsilyl, methyldi-t-butylsilyl, t-butyl dimethylsilyl, t
-7 tyldiphenylsilyl, triisopropylsilyl,
Tetraisopro and Rudicioxanil (TI PDS)
Silyl groups such as ethylidene, 10-pylidene, impropylidene, benzylidene, cyclohexylidene, cyclopentylidene, methoxymethylidene, ethoxymethylidene, dimethoxymethylidene, etc. Acetal or ketal type protecting groups: methoxycarbonyl, ethoxycarbonyl, When t-7 toxycarbonylcarbonyl R, R and/or R4 are phosphoric acid residues, they are represented by formula [11] or [1111]. M in formulas [II] and [I[[] represents one or more cations having a positive charge corresponding to the negative charge of the phosphate residue, specifically hydrogen ions, sodium ions, potassium ions, Examples include lesium ions, magnesium ions, and ammonium ions. The phosphoric acid residue of formula [■] forms a phosphate ester with one hydroxyl group of the ribose skeleton in the imidazole nucleoside derivative of formula [I], and the phosphoric acid residue of formula [II] forms a phosphate ester with two hydroxyl groups of the ribose skeleton in the imidazole nucleoside derivative of formula [I]. Forms a cyclic phosphate ester with a hydroxyl group.

The imidazole nucleoside derivative of formula [I] may be in the form of a salt, for example, hydrochloric acid, hydrobromic acid, sulfuric acid,
Inorganic acids such as phosphoric acid or citric acid, acetic acid, succinic acid,
Examples include acid addition salts with organic acids such as maleic acid, methanesulfonic acid, and pt-toluenesulfonic acid.

- The imidazole nucleoside derivative represented by [1] is a known compound and can be prepared by a known method [Pharmaceutical Society of Japan 1st-08th Annual Meeting, Collection of Lecture Abstracts, Vol.
1 page, 5EO6 2-1 (1988): Chei
．． Phart Bull. , 36 (7), 2
730, <1988): Japanese Unexamined Patent Publication No. 1-221388].

Specific examples of the imidazole nucleoside derivative represented by the general formula [I] are as follows.

5-ethynyl-1-β-D-ribofuranosylimidazole-4-carboxamide: 5-(3-hydroxy-1-propyn-1-yl)-1
-β-D-ribofuranosylimidazole = 4-carboxamide; 5-(3-hydroxy-1-butyn-1-yl)-1-
β-D-ribofuranosylimidazole-4-carboxamide; 5-(4-hydroxy-1-butyn-1-yl)1-β
-D-ribofuranosylimidazole-4-carboxamide: 5-(3,4-dihydroxy-1-butyn-1-yl)-1-β-D-ribofuranosylimidazole-4-carboxamide; 5-(3-hydroxy -1-pentyn-1-yl)-1
-β-D-ribofuranosylimidazole-4-carboxamide; 5-(4-hydroxy-1-pentyn-1-yl)-1
-β-D-ribofuranosylimidazole-4-carboxamide; 5-(5-hydroxy-1-pentyn-1-yl)-1
-β-D-ribofuranosylimidazole-4-carboxamide: 5- (3,4-dihydroxy-1-pentyn-1-yl)-1-β-D-ribofuranosylimidazole-4-
Carboxamide: 5-(4.5-dihydroxy-1-pentyn-1-yl)-1-β-D-ribofuranosylimidazole-4-carboxamide; 5-(4-hydroxy-3-methyl-1-butyne- 1-
)-1-β-D-ribofuranosylimidazole-4
-carboxamide; 5-(6-hydroxy-1-hexyn-1-yl>-1
-β-D-ribofuranosylimidazole-4-carboxamide; 5-(4-hydroxy-1-hexyn-1-yl)-1
-β-D-ribofuranosylimidazole 4-carboxamide; 5-(3-methyl-5-hydroxy-1-pentyne-1
-yl)-1-β-D-ribofura/cylimidazole-
4-Carboxamide.

Compounds in which the hydroxyl group of the ribose skeleton of the above-mentioned exemplified compound, especially the 5-position hydroxyl group, is protected with a phosphoric acid residue, and the hydrochloride, sulfate, and succinic acid of the above-mentioned exemplified compound are also exemplified as preferred compounds. can.

Imidazole nucleoside derivatives of formula [I] exhibit excellent antiviral activity. That is, for example, varicella stomatitis virus (νesicular 5tOllatiti
Svirus), Reovirus
), rose influenza virus (Parainflu
uenza virus), Koxara key virus (
Coxsackie virus), Polio virus, Herpes simplex virus
, Vaccinia virus
), influenza virus, Sindbis virus (
Cytopathic effects caused by viruses such as Sindbis virus and Semliki forest fever virus can be suppressed at extremely low concentrations. On the other hand, the imidazole nucleoside derivative of formula [1] has a low toxicity to cells and is highly safe. In formula [11, RR and/or R4
Of course, compounds in which is a protecting group or a phosphoric acid residue can also be used as active ingredients of the antiviral agent of the present invention.

The dosage of the compound of formula [I] or its salt, which is the active ingredient of the antiviral agent of the present invention, varies depending on the patient's severity, drug tolerance, etc., and is ultimately determined by the judgment of the doctor. However, it is usually 0.00% per day for adults.
02 to 2 g, which can be administered once or in divided doses. The administration method can be any method suitable for the administration route.

The antiviral agents of the present invention can be prepared for administration by any conventional formulation method.

For example, in the case of a preparation for oral administration, it is provided in a form suitable for absorption from the gastrointestinal tract, such as solid preparations such as tablets, capsules, powders, sugar-coated tablets, and granules; syrups, suspensions, and elixirs. It may be prepared as a liquid preparation such as a drug. For solids, binders such as syrup, gum arabic, gelatin, sorbitol, tragacanth, polyvinylpyrrolidone; lactose, sugar, cornstarch, calcium phosphate,
Excipients such as sorbitol and glycine; lubricants such as magnesium nistearate, talc, polyethylene glycol, and silica; disintegrants such as potato starch; and adjuvants such as wetting agents, stabilizers, and flavoring agents for pharmaceutical consideration. It can be selectively used and formulated according to the following. In the case of liquid preparations, sorbitol syrup, methylcellulose, glucose/sugar syrup, gelatin,
Suspending or emulsifying agents such as hydroxyethyl cellulose, carboxymethyl cellulose, aluminum stearate gel, and hydrogenated edible fat; preservatives such as methyl p-hydroxybenzoate, propyl p-hydroxybenzoate, and sorbic acid can be used.

When preparing a preparation for injection administration, the compound of formula [I] of the present invention or a salt thereof, which is the active ingredient of the present invention, may be added with a DH adjuster, a buffer, a stabilizer, a preservative, and a solubilizer, as necessary. etc., and prepare it as a subcutaneous, intramuscular, or intravenous injection using a conventional method.

EXAMPLES] The present invention will be explained in more detail below using test examples and formulation examples.

Test Example Measurement of Inhibition of Cytopathic Effect and Cytotoxicity (i) Test Compounds The following three compounds specifically described in JP-A-1-221388 were used as test compounds.

Compound A: 5-ethynyl-1-β-D-ribofuranosylimidazole-4-carboxamide Compound B: 5-(3-hydroxy-1-propyne-1-
yl)-1-β-D-ribofuranosylimidazole-4-carboxamide Compound C: 5-(4-hydroxy-1-butyn-1-yl)-1-β-D-ribofuranosylimidazole-4-carboxamide (ii) Test-1 Antimicrobial Agents and
CheIlotherapy.

VOl, 28. NQl, l), 84-89 (1985
), the suppression of the cytopathic effect of the virus by the test compound and the cytotoxicity of the test compound were investigated.

i.e. yer in microtiter plates.

The cells were cultured to a confluent state, and various virus stock solutions were added to the cultured cells at 100 rCID sO (
Ti5sue c'! i/1ture tntecti
Je oO3e -50) was inoculated (1 CCID
5o corresponds to the amount of virus inoculum required to infect 50% of the cultured cells), 1 hour after the virus was adsorbed to the cells, residual virus was removed, and 3% fetal bovine serum and various concentrations of the test compound were added. Replaced with Eagle's minimal essential medium. 100% cytopathic effect (CPE) of virus in virus-infected cultured cells not treated with test compound
CPE was measured in virus-infected cultured cells treated with the test compound immediately after it became observed. The concentration of the test compound required to inhibit virus-induced CPE by 50% was determined. The results are shown in Table 1.

Cytotoxicity was measured as follows. That is, virus-uninfected VerO cells as well as virus-infected
Cells were treated and incubated with various concentrations of test compounds. Virus infection ver.

Microscopic morphological observations were performed on virus-free Vero cells treated with test compounds when virus-induced cytopathic effects (CPE) were observed on the cells. Cell detachment and morphological degeneration were used as indicators of cytotoxicity, and the minimum concentration of the test compound that exhibited cytotoxicity was determined. The results are shown in Table 1.

The viruses used here were rose influenza virus type 3 (ATCC VR-93), reovirus type 1 (ATCC VR-230), Sindbis virus, and Coxsala key virus B4 [Life Sci.
, F., l), 187-194 (1975)], and Semliki Forest Fever Virus (ATCC VR-67).

(iii) Test-2 The same test as Test-1 was conducted using different test compounds. The results are shown in Table 2.

(1v) Test-3 Using large-derived kidney cells MDCK as cultured cells, influenza virus 5157 and B/Yamaaata/1/
73 was used to measure the inhibition of the cytopathic effect of the test compound using the method of Test-1 with some modifications as follows.

That is, MDCK cells were cultured to a confluent state in a microtiter plate, and each virus stock solution was inoculated into this cell culture in an amount of 10 TCID5o. Thirty minutes after virus adsorption to the cells, residual virus was removed and replaced with Eagle's minimal essential medium enriched with glucose and vitamins containing 0.2% bovine serum albumin and various concentrations of the test compound. A/Nimamo
In the system using to/Y 5 157, an additional 10μ9
/d of trypsin was added. Hereinafter, similarly to Test-1, the concentration of the test compound required to inhibit virus-induced CPE by 50% was determined.

The results are shown in Table 3.

As is clear from Tables 1 to 4 of Table 3, the compounds of the present invention can suppress the cytopathic effects caused by various viruses, and have low cytotoxicity and high safety.

Formulation Example 1 Preparation of tablets 5-nibnyl-1-β-D-ribofuranosylimidazole-4-carboxamide 109 cornstarch
65 g Carboxymethylcellulose Polyvinylpyrrolidone 3 g Prepare 100 square tablets in a conventional manner. One tablet contains 10 μ of 5-ethynyl-1-β-D-ribofuranosylimidazole-4-carboxamide.

Formulation Example 2 Powder and Capsule of 5-(3-hydroxy-1-buOvin-1-yl)-1
-β-D-ribofuranosylimidazole-4-carboxamide 209 The imidazole nucleoside derivative used in the present invention strongly suppresses the cytopathic effects caused by various viruses, and has low cytotoxicity and high safety. Therefore, the antiviral agent of the present invention containing the imidazole nucleoside derivative as an active ingredient is extremely excellent as a pharmaceutical and has great significance.

Claims (1)

[Claims] (1) The following general formula [I] ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [I] [In the formula, R^1 represents a hydrogen atom or a hydroxy lower alkyl group, and R^2, R^3, and R^ 4 represents a hydrogen atom, a hydroxyl group protecting group, or a phosphoric acid residue, respectively, and R^
2, R^3 and R^4 may be the same or different. ] An antiviral agent comprising an imidazole nucleoside derivative or a salt thereof as an active ingredient.