JP2018030801A - Sialic acid derivatives, production method thereof, and sialidase inhibitors, antimicrobials and antivirals using the same - Google Patents

Abstract

An object of the present invention is to provide a sialic acid derivative that is resistant to resistance and has strong inhibitory activity, and a sialidase inhibitor, antibacterial agent, and antiviral agent containing the sialic acid derivative as an active ingredient. A novel sialic acid derivative represented by the following general formula (I): [Chemical 1] [Selected figure] None

Description

  The present invention relates to a novel sialic acid derivative. Specifically, the present invention relates to a sialic acid derivative having an excellent sialidase inhibitory action and a sialidase inhibitor, antibacterial agent and antiviral agent using the same.

  As anti-influenza drugs, Tamiflu, Relenza, Inavir, Lapiacta, Symmetril, etc. are marketed in Japan. Influenza virus, after infecting host cells, grows in the cell and is released to the outside of the cell, and this release process requires an enzyme sialidase that cleaves sialic acid glycosides. Four species, except symmetril, are drugs that inhibit this sialidase.

  Sialidase (or neuraminidase, NA, EC 3.2.1.18) is a steric retention type glycosidase that hydrolyzes α-ketoside type bonds to release sialic acid. Commonly recognized substrates for sialidase include sialic acid (Neu5Ac and NANA) and N-glycolylneuraminic acid (Neu5Gc and NGNA) with an α2-3 or α2-6 ketoside linkage to galactose.

  The sialidase is present in various pathogenic bacteria Trypanosoma cruzi, Clostridium perfringens, Streptococcus neumoniae, Vibrio cholera, parainfluenza virus and influenza virus. There are many sialic acid-containing sugar chains in the biological environment such as animal tissues and mucus, which always adsorb the above pathogenic bacteria and viruses. As described above, sialidase present in pathogenic bacteria and viruses decomposes and cleaves these sialic acid-containing glycosides, so that the pathogenic bacteria can move in the living body. Therefore, sialidase inhibitors may be powerful antibacterial substances (for example, Patent Document 1) and are marketed as the above-mentioned various anti-influenza drugs (for example, Non-Patent Document 1).

  First generation sialidase inhibitors were designed based on sialic acid and its 2,3-dehydrogenated derivative 2-deoxy-2,3-didehydrosialic acid (Neu5Ac2en and DANA). All sialidase inhibitors currently on the market contain a carboxy group at the anomeric position and have a strong electrostatic interaction with three arginine residues at the active center of sialidase (for example, non-patent literature). 1). Among species of low relevance, the homology of the base sequence encoding sialidase is small, but a cluster containing three arginine residues in all known sialidases is highly conserved. For example, influenza A sialidase belongs to glycoside hydrolase family 34, and the three arginine residues are Arg118, Arg292, and Arg371. On the other hand, Clostridium perfringens NanI sialidase also belongs to family 33, but the arginine residues are Arg266, Arg555 and Arg615.

  The inhibition mechanism of sialidase is competitive inhibition in which a drug having a structure similar to that of the original substrate (sialic acid) is non-covalently fitted into the active center of sialidase. For this reason, it is easy for viruses to acquire resistance, such as weakening the affinity with drugs by changing the structure of the enzyme, and the emergence of Tamiflu-resistant viruses is a problem. Side effects such as abnormal behavior are also social problems.

  Since the sialic acid derivative having a structure similar to that of the natural substrate sialic acid is difficult to express a resistant enzyme, the carboxy group in the sialic acid derivative similar to the sialic acid of the natural substrate or a salt thereof has an affinity for the enzyme active center. For the purpose of enhancing the properties, a derivative substituted with a phosphono group and a salt thereof has been developed. It has been reported that a derivative substituted with a phosphono group has improved sialidase inhibitory activity by exhibiting a stronger electrostatic interaction with the above three arginine residues common to sialidase (for example, Non-Patent Document 2). . However, although the sialidase inhibitory activity of the derivative substituted with a phosphono group was improved, it was not strong enough.

  In contrast, the sialic acid derivative substituted with a sulfo group, which is expected to have a stronger electrostatic interaction with the arginine residue as compared to the phosphono group and to thereby increase the sialidase inhibitory activity. Synthesis has been attempted. For example, Colman et al. Refers to an anomeric sulfo group (Patent Document 2). Moreover, it is predicted by a computational chemistry method that a sialidase inhibitor having a sulfo group has the strongest binding ability as compared with a compound having a corresponding carboxy group or phosphono group (for example, Non-Patent Document 3). The current situation has not yet been realized. It is clear that the synthesis of a sialic acid derivative having a sulfo group substituted at the anomeric position is extremely difficult, and in fact, a sulfo group via a thiazole from a sugar derivative having an amino group or an acetamide group at the 2-position (adjacent position of the anomeric position). However, there is no report of a compound in which a sulfo group is substituted at the anomeric position with a deoxy sugar derivative at the 2-position. What has been difficult to synthesize so far is that there is no difference in chromatographic mobility in the separation operation of the precursor acetoxy compound and acetylthio compound, and the intermediate is also a mixture that is also difficult to separate. In addition, strict conditions are required for the oxidation of the acetylthio group, and the derivative in which the sulfo group is substituted at the anomeric position of the product is extremely water-soluble.

Japanese Patent No. 5327839 International Publication No. 1992/006691 Pamphlet

von Itzstein M (Editor). Influenzavirus sialidase-a drug discovery target. Springer Basel AG (2012). Journal of the American Chemical Society (2011) 133, 17959-17965. Current Pharmaceutical Design (2016) 22, 3478-3487. The Journal of Organic Chemistry (2006) 71, 1380-1389.

  An object of the present invention is to provide a sialic acid derivative that is resistant to resistance and has a strong inhibitory activity, and a sialidase inhibitor, antibacterial agent, and antiviral agent containing the sialic acid derivative as an active ingredient.

  As a result of intensive studies in view of the above circumstances, the present inventors produce a derivative in which the carboxy group of sialic acid is substituted with a sulfo group or the like for the purpose of enhancing the covalent bondability and affinity with the sialidase enzyme. As a result, the present inventors have found that the above problems can be solved and have completed the present invention. That is, the inventors have found a method for obtaining the first synthesis of a sialic acid derivative having a sulfo group substituted at the anomeric position by oxidation reaction of a mixture of four intermediates having an acetylthio group at the anomeric position.

That is, the present invention has the following configuration.
(1) General formula (I):
[In Formula (I), (A) and (B) each independently represent R ¹ , SO ₃ R ² or SO ₂ R ² . Here, R ¹ is a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom or OAc, and R ² is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group having 1 to 20 carbon atoms, or When (A) is SO ₃ R ² or SO ₂ R ² , (B) is R ¹ , and (B) is SO ₃ R ² or SO ₂ R ² , A) is R ¹ . (C) and (D) represent R ¹ , (E) represents a hydroxy group, an amino group or NHC (═NH) NH ₂ , and (F) represents a hydrogen atom, C (═O) CH ₃ or C (═O) CF ₃ is represented, and R ⁶ , R ⁷ and R ⁸ each independently represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms or C (═O) CH ₃ . ] The sialic acid derivative characterized by the above-mentioned.
(2) General formula (II):
[In Formula (II), (A) and (B) each independently represents R ¹ , SO ₃ R ² or SO ₂ R ² . Here, R ¹ is a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom or OAc, and R ² is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group having 1 to 20 carbon atoms, or When (A) is SO ₃ R ² or SO ₂ R ² , (B) is R ¹ , and (B) is SO ₃ R ² or SO ₂ R ² , A) is R ¹ . (F) represents a hydrogen atom, C (═O) CH ₃ or C (═O) CF ₃ , and R ⁶ , R ⁷ and R ⁸ are each independently a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. Alternatively, C (═O) CH ₃ is represented. ] The sialic acid derivative characterized by the above-mentioned.
(3) The sialic acid derivative as described in (1) or (2) above, wherein (A) is a sulfo group.
(4) The sialic acid derivative as described in (1) or (2) above, wherein (B) is a sulfo group.
(5) A sialidase inhibitor comprising the sialic acid derivative according to any one of (1) to (4) as an active ingredient.
(6) An antibacterial agent comprising the sialic acid derivative according to any one of (1) to (4) as an active ingredient.
(7) An antiviral agent comprising the sialic acid derivative according to any one of (1) to (5) as an active ingredient.
(8) In the method for producing a sialic acid derivative according to (1) or (2), the following formulas (3a) 1R, (3b) 1S:
And / or the following formula (4a) 1R, (4b) 1S:
Are each oxidized using an oxidizing agent,
The following formula (5a) 1R, (5b) 1S:
And / or the following formula (6a) 1R, (6b) 1S:
A process for obtaining a compound represented by the formula:

  According to the present invention, it has a sulfo group that has stronger acidity and electroattractive properties than conventional carboxy groups and phosphono groups, and has a stronger bond with the enzyme active center, so that sialidase inhibitory activity is stronger. . Moreover, since it has a structure very similar to that of the natural substrate sialic acid, there is an effect that the resistant enzyme is hardly expressed.

An example of the manufacturing method of the sialic acid derivative which concerns on this invention is shown. An example of the inhibitory activity of the sialic acid derivative according to the present invention is shown. An example of the inhibitory activity of the sialic acid derivative according to the present invention is shown. An example of the inhibitory activity of the sialic acid derivative according to the present invention is shown.

  Hereinafter, embodiments of the present invention will be described in detail. As described above, the sialic acid derivative according to the present invention is represented by the general formula (I) and / or the general formula (II).

In the general formulas (I) and (II), (A) and (B) are each independently selected and represent R ¹ , SO ₃ R ² or SO ₂ R ² . R ¹ represents a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom or OAc, and R ² represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group having 1 to 20 carbon atoms, or a positive electrode Ions are shown. Examples of the alkyl group having 1 to 20 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, s-butyl group, t-butyl group, pentyl group, and isopentyl group. , A neopentyl group, a hexyl group, an octyl group and the like, and a linear or branched alkyl group. Examples of the aryl group having 1 to 20 carbon atoms include phenyl group, naphthyl group, tolyl group, xylyl group, anthryl group, and phenanthryl group. The “counter cation” means a cation of the following substances, and examples of the cation include an alkali metal such as lithium, an alkaline earth metal such as beryllium, a base metal such as zinc, and a noble metal such as copper. , Transition metals such as iron, lanthanoids such as cerium, primary amines such as ammonia and methylamine, secondary amines such as dimethylamine, tertiary amines such as trimethylamine, aromatic amines such as pyridine, tetramethylammonium Quaternary ammonium salts such as amidine acetate, guanidines such as guanidine, amino acids such as lysine, alcohol amines such as ethanolamine, amino sugars such as glucosamine, biological alkaloids such as choline and caffeine, etc. Of cations. SO ₃ R ² is preferably SO ₃ H. SO ₂ R ² is preferably SOOH.

In the above general formulas (I) and (II), when (A) is SO ₃ R ² or SO ₂ R ² , (B) is R ¹ and (B) is SO ₃ R ² or SO _2. When R ² , (A) is R ¹ .

Further, in the general formula (I), (C) and (D) represents R ^1, (E) represents a hydroxy group, an amino group, or _{NHC (= NH) NH 2,} (F) is a hydrogen atom, C (═O) CH ₃ or C (═O) CF ₃ is represented, and R ⁶ , R ⁷ and R ⁸ are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms or C (═O) CH _3. Represents.

  As described above, the sialic acid derivative of the present invention represented by the general formulas (I) and (II) has a structure in which a sulfo group is present at the anomeric position. By having such a structure, the acid dissociation constant pKa is small compared with the structure in which a carboxyl group or a phosphono group exists, so that it dissociates well, so that it strongly interacts with three arginine residues at the enzyme active center. Inhibitory activity increases.

  In addition, the above structure has a very high structural similarity with the natural substrate sialic acid, and it can be expected that resistant enzymes are unlikely to appear.

  Examples of the compounds represented by the general formulas (I) and (II) according to the present invention include the following compounds (9) to (12). However, the sialic acid derivative according to the present invention is not limited to these.

(Synthesis method)
The compounds contained in the formulas (I) and (II) in the present invention can be synthesized by the production method shown below. FIG. 1 shows an example of a method for producing a sialic acid derivative according to the present invention.

[Synthesis of Compounds (2a) and (2b)]
Compound (2a) (acetyl-4-acetamido-3,6,7,8-tetra-O-acetyl-2,4-dideoxy-β-D-glycero-D-galacto-octopyranoside) and compound (2b) (compound The α-form of 2a can be synthesized from sialic acid according to a known method (for example, Non-Patent Document 2).

[Synthesis of Compounds (3a) and (3b)]
In the present invention, the known compounds (2a) and (2b) in which the hydroxy group is protected as an acetate ester are preferably used as starting materials. In addition to the acetate ester, formic acid, chloroacetic acid, propionic acid, benzoic acid, etc. These esters can also be used as protecting groups. In addition, trialkylsilyl ether protecting groups such as triethylsilyl group, alkyl ether protecting groups such as benzyl group and methoxymethyl group, and carbamate protecting groups such as tert-butoxycarbonyl group can also be used. It is not limited to.

  The thioacetic acid ester compounds (3a) and (3b) and the corresponding 2,3-position deacetic acid compound (4a) are obtained using thioacetic acid by substitution reaction of the anomeric acetoxy group of the compounds (2a) and (2b). (4b) can be synthesized. The synthesis of sialic acid derivatives in which the C-1 position is decarboxylated and the sulfur functional group is substituted in the anomeric position is novel. The acid catalyst used in this reaction is preferably trialkylsilyl trifluoromethanesulfonate, particularly trimethylsilyl trifluoromethanesulfonate, but aprotic Lewis acids such as boron trifluoride, trichloroaluminum, dichlorozinc, and toluenesulfonic acid. , Sulfuric acid, hydrogen chloride and the like may be used. Although there is no restriction | limiting in particular in these usage-amounts, the range of 0.1-20 mol times is preferable with respect to compound (2a) and (2b) normally, and the range of 0.5-10 mol times is more preferable.

  The solvent is preferably a chlorinated solvent such as dichloromethane or 1,2-dichloroethane, or a hydrocarbon solvent such as toluene, cyclohexane or hexane, but an ether solvent such as diethyl ether or tetrahydrofuran, a nitrile such as acetonitrile, acetone or the like. Aprotic polar solvents such as ketones, dimethyl sulfoxide and N, N-dimethylformamide may also be used. Although there is no restriction | limiting in particular in the usage-amount, the range of 1-200 weight times is preferable with respect to a compound (2a) and (2b) normally, and the range of 5-20 weight times is more preferable. The reaction temperature is preferably in the range of −40 to 40 ° C., more preferably in the range of −20 to 30 ° C. The reaction time varies depending on the reaction conditions, but is usually preferably within 72 hours.

  Compounds (3a) and (3b) and mixtures containing compounds (4a) and (4b) were prepared by converting the thioacetyl group into a sulfo group by oxidation reaction using an oxidizing agent (5a) and (5b), respectively. And a separable mixture of compounds (6a) and (6b) can be synthesized. A reaction in which the hydroxy group at the C-6 position of a glucose derivative is substituted with a thioacetyl group and oxidized to a sulfo group using an oxidizing agent is known (for example, Tetrahedron Letters (2004) 45: 839-842). This reaction to do this is novel.

Oxone (registered trademark) is most preferable as the oxidizing agent for this oxidation reaction, but various other oxidizing agents can be used. For example, dimethyl dioxirane (DMDO), 3-methyl-3-trifluoromethyl dioxirane, 3-chloro acid (MCPBA), hydrogen peroxide (H ₂ O _2), N- bromoacetamide, N- bromosuccinimide Imido (NBS), N-chlorosuccinimide (NCS), N-iodosuccinimide (NIS), Dess-Martin reagent, IBX reagent, perhalogen acid and its salt, halogen acid and its salt, halogen acid and its salt Further, an oxidizing agent having a halogen such as hypohalite and dimethyl sulfoxide (DMSO) are preferable. Besides these, transition metal oxidants such as chromium trioxide and potassium permanganate and oxygen molecules may be used. Although there is no restriction | limiting in particular in the usage-amount of the said oxidizing substance, The range of 5-50 mol times is preferable with respect to compound (3a) and (3b) and compound (4a) and (4b) normally, 5-20 mol times The range of is more preferable.

  The oxidation reaction is preferably performed in a buffer containing carboxylic acid. As the buffer solution, acetic acid-ammonium acetate is preferable, and a buffer solution, phosphate buffer solution, universal buffer solution or the like containing ammonium formate, potassium acetate, sodium acetate, or the like may be used. Also, protic polar solvents such as water and methanol, chlorine solvents, hydrocarbon solvents, ether solvents, ester solvents, nitriles such as acetonitrile, ketones such as acetone, dimethyl sulfoxide and N, N-dimethylformamide A mixed system with an aprotic polar solvent can also be used, but is not limited thereto. Although there is no restriction | limiting in particular in the usage-amount, Usually the range of 1 to 200 weight times is preferable with respect to compound (3a) and (3b) and compound (4a) and (4b), and the range of 5 to 20 weight times is more preferable. The reaction temperature is preferably in the range of -20 to 50 ° C, more preferably in the range of 10 to 30 ° C. The reaction time varies depending on the reaction conditions, but is usually preferably within 96 hours.

  In the post-treatment of the oxidation reaction, excess salts are removed by filtration, and the filtrate is concentrated under reduced pressure. A mixture of compounds (5a) and (5b) and compounds (6a) and (6b) can be separated by silica gel column chromatography using a mixed solvent of ethyl acetate and ethanol as an eluent.

In a series of reactions from the compounds (2a) and (2b) to the compounds (5a) and (5b) and the compounds (6a) and (6b), an alternative synthetic method can be used for introduction of the sulfo group. H ₂ S, alkyl mercaptan, and alkylthioacetic acid can be used for addition and substitution reactions at the anomeric position as thionucleophilic substitutes for thioacetic acid, but are not limited thereto. The alkyl mercaptan preferably has C ₁ -C ₂₀ carbon atoms, and most preferably C ₁ -C ₃ and C ₁₂ . Alkylthio acetate is preferably _{C 1 -C 20, C 1 -C} 3 and C ₁₂ being most preferred. A synthetic route for anomeric sulfo group-bound derivatives from sialic acid glycoside derivatives can also be used. Anomer thioesters and thioethers are probably hydrolyzed to the corresponding thiols before being oxidized.

  It is most preferable to use a mixed solvent of aqueous sodium hydroxide and methanol for the deprotection of the acetates which are the protecting groups of the compounds (5a) and (5b) and the compounds (6a) and (6b). It can also be carried out by hydrolysis or alcoholysis near neutral and acidic conditions. Bases under basic conditions include alkali metals such as lithium, alkaline earth metals such as beryllium, base metals such as zinc, noble metals such as copper, transition metals such as iron, lanthanoids such as cerium, and fourth metals such as tetramethylammonium. Hydroxides with quaternary ammonium salts as counter ions, alkoxides, carbonates, etc., primary amines such as ammonia and methylamine, secondary amines such as dimethylamine, tertiary amines such as trimethylamine, and fragrances such as pyridine Sodium cyanide such as aromatic amines, amidines such as amidine acetate, guanidines such as guanidine, amino acids such as lysine, alcohol amines such as ethanolamine, amino sugars such as glucosamine, and biological alkaloids such as choline and caffeine Alkaline metal or alkaline earth And the like can be used cyanide, but is not limited thereto. Although there is no restriction | limiting in particular in the usage-amount of these basic substances, Usually, the range of 5-50 mol times is preferable with respect to compound (5a) and (5b) and compound (6a) and (6b), and 5-20 mol A range of double is more preferable.

  Under slightly acidic to neutral to slightly basic conditions, an enzyme catalyst having hydrolytic ability derived from microorganisms or animals and plants can be used. Examples of the enzyme include enzymes produced by microorganisms belonging to the genus Pseudomonas, enzymes produced by microorganisms belonging to the genus Burkholderia cepacia, enzymes produced by microorganisms belonging to the genus Mucormiehei, and enzymes derived from porcine pancreas. Examples include lipase P (manufactured by Nagase Sangyo), lipase P (manufactured by Amano Pharmaceutical), lipase PS (manufactured by Amano Pharmaceutical), and pancreatin which is an enzyme derived from porcine pancreas. The amount of enzyme used is usually preferably in the range of 0.01 to 200% by weight, more preferably in the range of 0.1 to 100% by weight with respect to the compounds (5a) and (5b) and the compounds (6a) and (6b). preferable.

  Acids under acidic conditions include, but are not limited to, aprotic Lewis acids such as trialkylsilyl trifluoromethanesulfonate, boron trifluoride, trichloroaluminum, dichlorozinc, toluenesulfonic acid, sulfuric acid, hydrochloric acid, etc. Is not to be done. Although there is no restriction | limiting in particular in the usage-amount of these acidic substances, The range of 0.2-20 mol times with respect to compound (5a) and (5b) and compound (6a) and (6b) is preferable normally, 0.5 The range of 10 mol times is more preferable.

  Protic polar solvents such as water and methanol are used as the solvent. Chlorine solvents, hydrocarbon solvents, ether solvents, ester solvents, nitriles such as acetonitrile, ketones such as acetone, dimethyl sulfoxide, N, N A mixed system with an aprotic polar solvent such as dimethylformamide may be used, but is not limited thereto. In the enzyme-catalyzed reaction, the above solvent can be used, but a mixed solvent with a buffer solution can also be used. Although there is no restriction | limiting in particular in the usage-amount, Usually, the range of 1 to 200 weight times is preferable with respect to compound (5a) and (5b) and compound (6a) and (6b). The reaction temperature is preferably in the range of -20 to 100 ° C, more preferably in the range of 0 to 30 ° C. The reaction time varies depending on the reaction conditions, but is usually preferably within 96 hours.

  The sialic acid derivative having a sulfo group bonded to the anomeric position in the present invention can also be synthesized as a sulfonate. For example, if the thioacetate precursor compounds (3a) and (3b) and the compounds (4a) and (4b) are oxidized with an oxidizing agent in an acetic acid-potassium acetate buffer, the compounds (5a) and (5b) And the compounds (6a) and (6b) can be obtained as the corresponding potassium salts of sulfonic acids. If ammonium acetate is used instead of potassium acetate, an ammonium salt of sulfonic acid can be synthesized. By using ammonium acetate instead of potassium acetate, it is possible to avoid the difficulty of purification by precipitation of salts in the step of oxidizing the acetylthio group to a sulfo group using an oxidizing agent such as potassium persulfate. In the oxidation reaction of compounds (3a) and (3b) and compounds (4a) and (4b) or sulfonic acid precursors not limited thereto, a preferred sulfonate is synthesized using the various counter cations described above. Can do. When chromatography is performed in the presence of a preferred cation, preferred sulfonic acids can be obtained as preferred metal and non-metal salts.

  The sialic acid derivative having a sulfo group bonded to the anomeric position in the present invention can also be used as a prodrug for improving bioavailability. This includes functionalization of anomeric sulfo groups and / or existing hydroxy groups. For example, sulfonic acid methyl esterification of the compounds (7a) and (7b) proceeds well when trimethylsilyldiazomethane is used. Orthoformate alkyl esters and alkyl halides can also be used in the synthesis of sulfonate esters. The sialic acid derivative having a sulfo group bonded to the anomeric position of the present invention can also be synthesized as phenols, pentafluorophenol (PVP), or 2,2,2-trifluoroethyl ester.

The sialic acid derivative according to the present invention is a compound shown below, and includes a compound (13), (14) or (15) which is a 1,2-dehydrogenated derivative. These derivatives include compounds (3a) and (3b), compounds (5a) and (5b), and anomeric bromides and their basic elimination reactions by radical bromination of the anomeric positions of compounds (7a) and (7b), respectively. Can be synthesized. Compound (13), (14) or (15) is obtained by dehydration of compounds (3a) and (3b), compounds (5a) and (5b) or compounds (7a) and (7b) with an oxidizing agent such as DDQ or IBX. It can also be synthesized by an elementary reaction.

Of the sialic acid derivatives in which a sulfo group is bonded to the anomeric position according to the present invention, a compound in which one or more of (A), (B), (C) or (D) are halogenated, for example, the following compounds ( 16), (17) or (18) can be synthesized using electrophilic halogenation, radical halogenation, nucleophilic halogenation, or the like. The following reagents can be used for this, but are not limited to the following. Xenon difluoride, bromine, fluorine, chlorine, iodine, hydrogen bromide, hydrogen fluoride, hydrogen chloride, hydrogen iodide, iron bromide, titanium bromide, titanium chloride, N-bromosuccinimide, N-bromo Acetamide, N-chlorosuccinimide (NCS), N-iodosuccinimide (NIS), 1-chloromethyl-4-fluoro-1,4-diazoniabicyclo [2.2.2] octane = bistetrafluoroborate (Selectfluor ®) N- fluorobenzenesulfonimide (NFSI), N-fluoro-2,6-dichloro pyridinium tetrafluoroborate, (diethylamino) difluorosulfoacetate tetrafluoroborate (XtalFluor-E ^®), diethylaminosulfur = Trifluoride (DAST).

“SO ₃ ” used above represents a sulfo group, sulfonate or ester as a substituent, and “SO ₃ H” represents sulfonic acid. “SO ₂ ” represents a sulfino group, sulfinate or ester as a substituent, and “SO ₂ H” represents sulfinic acid. Also, possible stereoisomers of all the compounds described are included in the present invention.

  The sialic acid derivative according to the present invention can be used for treating prokaryotic microorganisms, eukaryotic parasites, sialidases, and viruses having hemagglutinin-sialidase. Although the following are included as said treatment object, it is not limited to them. That is, Clostridium perfringens, Streptococcus pneumoniae and Vibrio cholera are mentioned as prokaryotic microorganisms, and Trypanosoma cruzi is mentioned as the eukaryotes. In addition, viruses that cause diseases such as Newcastle disease, mumps, parainfluenza, influenza, and the like, and organisms including any of the sialidase family G33, G34, GH83, and GH58 are included.

  Moreover, the sialic acid derivative according to the present invention can be used regardless of whether the infecting microorganism is a wild strain or a drug resistant strain. This includes, but is not limited to: That is, the influenza sialidase mutant Glu105Lys, Glu116Ala, Glu116Asp, Glu116Gly, Glu116Val, Glu119Val, Glu119Gly, Gln136Lys, Arg150Lys, Asp151Ala, Arg152Lys, Asp197Asn, Asp199Gly, Ile223Arg, Ile223Val, Ser247Asn, His273Tyr, His275Tyr, Arg292Lys, Asn294Ser and Arg371Lys (influenza N1 The amino acid number of the strain was used).

  The sialic acid derivative according to the present invention can be used for infection of any organism including all animals and plants.

  Moreover, the sialic acid derivative according to the present invention can be used with various auxiliaries that assist the selective transportation to the infected site. For example, polyethylene glycol, liposome, micelle, spherical fullerene, DNA fine structure and the like are not limited thereto.

  In addition, when the sialic acid derivative according to the present invention is incorporated into humans or animals, any method relating to drug delivery, such as oral, intranasal spray, and intravenous injection, can be used. It can also be inhaled from the lungs using an appliance such as an electric cigarette.

  In addition, the sialic acid derivative according to the present invention can be derivatized to prevent toxicity and side effects. It can also be derivatized to prevent interference with human-derived molecules.

  Any combination of the compounds according to the present invention described above can be used for the treatment of infectious diseases.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and the sialic acid derivative of this invention is demonstrated in detail, this invention is not limited only to a following example.

As shown in FIG. 1, the method for producing a sialic acid derivative of the present invention includes the following steps.
That is, the following formulas (3a) 1R, (3b) 1S:
And / or the following formula (4a) 1R, (4b) 1S:
Are each oxidized using an oxidizing agent,
The following formula (5a) 1R, (5b) 1S:
And / or the following formula (6a) 1R, (6b) 1S:
A process for obtaining a compound represented by formula (I) and / or a method for producing a sialic acid derivative represented by formula (II).

[Synthesis of Compounds (2a) and (2b)]
Compound (2a) (acetyl = 4-acetamido-3,6,7,8-tetra-O-acetyl-2,4-dideoxy-α-D-glycero-D-galacto-octopyranoside) and compound (2b) (compound The β-form of (2a) can be synthesized from sialic acid according to a known method (for example, Non-Patent Document 2).

  Specifically, sialic acid is first dissolved in a mixture of pyridine and acetic anhydride (1: 1 in molar ratio). Next, after mixing at room temperature for 6 to 24 hours, heat quickly and reflux for 1 to 4 hours. The resulting solution is evaporated under reduced pressure and the residue is resuspended in chloroform.

The resuspended organic layer is then washed with an aqueous solution of NaHCO ₃ , 1M HCl, and brine, and the resulting organic layer is dried over MgSO ₃ , filtered through Celite under reduced pressure, and concentrated. A mixture comprising compounds (2a) and (2b) in a molar ratio of about 1: 5 by separating the concentrated crude product using silica flash chromatography with an EtOAc: hexane gradient. Can be obtained.

[Synthesis of Compounds (3a) and (3b) and Compounds (4a) and (4b)]
A mixture (254 mg, 0.534 mmol) containing compounds (2a) and (2b) in a molar ratio of about 1: 5 was dissolved in distilled 1,2-dichloroethane (6 mL) under a nitrogen atmosphere and about -10 ° C. And ice-cooled. Next, thioacetic acid (0.227 mL, 3.22 mmol) and trifluoromethanesulfonic acid trimethylsilyl ester (0.581 mL, 3.21 mmol) were added to the ice-cooled mixed solution, and the reaction was continued while gradually heating to 20 ° C. The mixture was stirred for 20 hours until the end of the process.

  Next, ice and saturated aqueous sodium hydrogen carbonate solution were added to the resulting reaction solution, and the mixture was extracted with chloroform. Therefore, the organic layer was separated, washed with water and a saturated aqueous sodium chloride solution, dried over anhydrous magnesium sulfate, the resulting solid was filtered through celite, and the filtrate was concentrated under reduced pressure. The residue was purified by column chromatography using silica gel (15 g) (eluent was ethyl acetate), and the compounds (3a), (3b) and compounds (4a), (4b) (144 mg, about 58) were obtained as oily substances. % Yield) as a mixture in a molar ratio of about 16: 30: 1: 34.

Analytical values of a mixture of the synthesized compounds (3a) and (3b) are shown below.
(3b) (1S-anomer: axial position SAc group anomer, CJV055401 (= the number assigned to the substance obtained in the experiment, the same applies hereinafter)). ¹ H-NMR (600 MHz, CDCl ₃ ): 1.91 (1s, 3H, NHAc), 1.98-2.12 (4s, 12H, 4OAc), 2.15 2.19 (ddd, 1H, J _{2ax, 1} = 1.6, J _{2ax, 2eq} = 13.6, J _{2ax , 3} = 5.1, H-2ax), 2.30-2.36 (m, 1H, H-2eq), 2.34 (1s, 3H, SAc), 3.90-3.92 (dd, 1H, J 5,4 = 10.4, J 5,6 = 1.9, H- 5), 4.01-4.05 (m, 2H, H-4 and H-8) 4.26-4.29 (dd, 1H, J _{8 ', 7} = 2.9, J _{8', 8} = 12.6, H-8 ′), 4.98-5.03 (ddd, 1H, J _3,2eq = 4.7, J = 10.3, J = 11.7, H-3), 5 .11-5.14 (ddd, 1H, J _7,6 = 7.2, J _{7, 8} = 6.3, J _{7,8 ′} = 2.9, H-7), 5.30-5.32 (dd, 1H, J _6,5 = 1.9, J _6,7 = 7.2 , H-6), 5.40-5.42 (d, 1H, J = 10, NH), 6.13-6.14 (d, 1H, _J1,2ax = 4.7, H-1). ; + ESIHRMS calcd _{C 20 H 29 NNaO 11 S:} 514.1359, ^{Found: m / z514.1393 [M + Na} ] + (150710-CJV031302).

Analytical values of the mixture of synthesized compounds (4a) and (4b) are shown below.
(4b) (1S-anomer: axial position SAc group anomer, CJV055401, CJV030702). ¹ H-NMR (600 MHz, CDCl ₃ ): 1.99, 2.02, 2.10, 2.13 (4s, 12H, (4a) c), 2.36 (Rf = 0.4 (EtOAc); 1s, 3H, SAc) 3.84-3.86 (dd, 1H, J _5,4 = 10, J _5,6 = 1.8, H-5), 4.10-4.13 (m, 1H , H-8), 4.29-4.32 (dd, 1H, J _{8 ′, 8} = 12.6, J _{8 ′, 7} = 2.6, H-8 ′), 4.48-4. 51 (t, 1H, J _4,3 and J _4,5 = 9.7, H-4), 5.19-5.22 (ddd, 1H, J _7,6 = 7.8, J _7,8 = 5.6, J _{7,8 '} = 2.6H-7), 5.31-5.33 (dd, 1H, J _6,5 = 1.8, J _6,7 = 7.8, H- 6), 5.52-5.54 (d, 1H, J _{NH, 4} = 9.4 Hz, NH) 5.80 (s, 2H, H-2, H- 3) 6.27 (s, 1H, H-1); + ESIHRMS calcd _{C 18 H 25 NNaO 9 S:} 454.1148, ^{Found: m / z454.1177 [M + Na} ] + (150710-CJV031302).

Analytical values of the synthesized compounds (3a) and (3b) and a mixture of the compounds (4a) and (4b) are shown below.
Mixtures of (3a) and (3b) and (4a) and (4b). Main component ¹³ C-NMR peak (150 MHz, CDCl ₃ , CJV055401): 20.67, 20.70, 20.91, 21.06, 23.16 and 23.34 (CH ₃ COO, CH ₃ CONH and CH ₃ COS), 31.19, 36.13, 43.55, 50.10, 62.05, 62.07, 67.3467.37, 69.26, 69.60, 69.86, 72.45, 78.66 and 79.01 (C-1 to C-8), 125.62 and 131.15 (C-2 and C-3 of (4a) and (4b)), 169.41, 169.56, 169.79,170.00,170.48,170.50 and 170.97 (CH ₃ COO and CH ₃ CONH), 191.40 and 192.82 (CH ₃ COS);

Analytical values of the synthesized compounds (3a) and (3b) and a mixture of the compounds (4a) and (4b) are shown below.
Mixtures of (3a) and (3b) and (4a) and (4b). ¹³ C-NMR peak of minor component (150 MHz, CDCl _3, CJV055401): 20.45 _, 20.71 _, 20.73 _, 20.76 _, 20.85 _, 23.11, 23.18 and 23.29 (CH ₃ COO, CH ₃ CONH and CH ₃ COS), 30.55, 30.58, 30.75, 33.01, 35.47, 43.17, 48.24, 49.13, 61.37, 67. 28, 67.73, 68.26, 70.06, 70.14, 70.24, 71.89 and 76.17 (C-1 to C-8), 91.18, 126.89 and 130.62. (C-2 and C-3 of (4a) and (4b)), 167.82, 168.97, 169.35, 169.41, 169.56, 169.72, 169.86, 170.12 170.15, 170.24, 170.5 4 and 170.86 (CH ₃ COO and CH3CONH), 192.14 and 192.75 (CH ₃ COS).
CJV055401 is about 15% of 1,7-lactone cyclized (5-acetamido-2,4,8,9-tetra-O-acetyl-β-D-glycero-D-galacto-2-nonuropyranosone-7-olide ): ¹³ C-NMR (150 MHz, CDCl ₃ , CJV04301): 20.47, 20.74, 20.76, 20.79, 20.95 and 23.19 (CH ₃ COO, CH ₃ CONH and CH ₃ COS), 30.91, 33.05, 48.23, 61.39, 67.67, 70.31, 71.94 and 76.18 (C-2 to C-8), 91.18, 91. .35,164.42,167.86,169.01,169.33,169.78,170.59 (CH ₃ COO and CH ₃ CONH).

[Synthesis of Compounds (5) and (5b) and Compound (6b)]
A solution of compounds (3a) and (3b) obtained above and a mixture (854 mg, about 1.8 mmol) of acetic acid (12 mL) in a molar ratio of compounds (4a) and (4b) of about 16: 30: 1: 34 Were added ammonium acetate (about 1 g, about 13 mmol, about 7.8 equivalents) and Oxone (registered trademark) (3.67 g, 11.9 mmol, 7.17 equivalents) and stirred at 20 ° C. for about 19 hours. Next, methanol (about 10 mL) was added to the obtained reaction liquid, insoluble matter was filtered using celite, and the filtrate was concentrated under reduced pressure. The residue was purified by column chromatography using silica gel (12.6 g) (the eluent was obtained by sequentially changing the ratio of ethyl acetate and ethanol), and the compounds (5a) and (5b) and the compound ( 6b) (525 mg) was obtained as a mixture in a molar ratio of about 2: 5.6: 1.

Analytical values of the synthesized compound (5a) are shown below.
(5a) (1R-anomer: equatorial sulfonate). Rf = 0.39 (EtOAc: EtOH = 2: 1); ¹ H-NMR (400 MHz, CD ₃ OD, CJV043403): 1.8-2.0 (m, 1H, H-2ax) 1.85 (s , 1H, NAc), 1.97-2.08 (4s, 12H, 4OAc), 2.46-2.51 (ddd, 1H, _{J2eq, 1} = 2.1, _{J2eq, 2ax} = 12.6). , J _{2eq, 3} = 5.1, H-2 eq), 3.79-3.83 (dd, 1H, J _5,4 = 10.4, J _5,6 = 2.3, H-5), 3.93-4.00 (q, 1H, J _4,3 = 10.4, J _4,5 = 10.4, H-4), 4.19-4.25 (dd, 1H, J _{8, 7} = 12.3, J _{8,8 ′} = 6.3, H-8) 4.24-4.28 (dd, 1H, J _1,2ax = 11.8, J _1,2eq = 2.1, H-1), 4.51-4.55 (dd , 1H, J 8 ', 7 = _{.8, J 8 ', 8 =} 12.4, H-8'), 4.96-5.03 (ddd, 1H, J 3,2ax = 11.3, J 3,2eq = 5.1, J _3,4 = 10.2, H-3), 5.28-5.32 (td, 1H, J _7,6 = 6.2, J _7,8 = 6.2, J _{7,8 '} = 2 .7, H-7), 5.38-5.41 (m, 1H, H-6); - ESIHRMS calculated ^{_{C 18 H 26 NO 13 S -}} : 496.1130, Found: m / z496.1142 [M-H] ^- (160212-CJV051301).

Analytical values of the synthesized compound (5b) are shown below.
(5b) (1S-anomer: axial sulfonate). Rf = 0.4 (EtOAc: EtOH = 2: 1); 1H-NMR (600 MHz, CD ₃ OD, CJV060501): 1.84 (s, 3H, NAc) 1.9-2.1 (m, 1H, H2ax), 1.97, 2.00, 2.07 and 2.08 (4s, 12H, 4OAc), 2.66-2.70 (ddd, 1H, _{J2eq, 1} = 1, _{J2eq, 2ax} = _{13.9, J 2eq, 3 = 5.4H} -2eq), 3.94-3.97 (t, 1H, J 4,3 = 10.3, J 4,5 = 10.3, H-4) 4.11-4.14 (dd, 1H, J _8,7 = 5.3, J _{8,8 '} = 12.6, H-8), 4.41-4.43 (dd, 1H, J _{8 ′, 7} = 2.9, J _{8 ′, 8} = 12.3, H-8 ′), 4.65-4.67 (dd, 1H, J _1,2ax = 6.7, H−1) , 4.76-4.78 (dd, 1H, J 5,4 = 10. _{, J 5,6 = 2.2, H-} 5), 5.20-5.22 (ddd, 1H, J 7,6 = 7.8, J 7,8 = 5.1, J 7,8 ' = 2.6, H-7), 5.39-5.40 (dd, 1H, J _6,5 = 2.2, J _6,7 = 7.8, H-6), 5.55-5. _.60 (td, 1H, J _3,2ax = 10.5, J _3,2eq = 5.4, J _3,4 = 10.5, H-3); ¹³ C-NMR (150 MHz, CDCl ₃ ): 20.69,20.83,20.87,21.29 and 22.63 (CH ₃ COO and _{CH 3 CONH), 31.45 (C} -2), 50.70 (C-4), 63.06 69.07, 70.97, 71.01 and 72.95 (C-3 and C-5 to C-8), 85.83 (C-1), 171.64, 171.98, 172.18. When 172.58 (CH ₃ COO and CH ₃ CONH); - E IHRMS Calculated ^{_{C 18 H 26 NO 13 S -}} : 496.1130, ^{Found: m / z496.1142 [M-H} ] - (160212-CJV051301).

The analysis value of the synthesized compound (6b) is shown below.
(6b) (1S_anomer: axial sulfonate). Rf = 0.39 (EtOAc: EtOH = 2: 1); ¹ H-NMR (600 MHz, CD ₃ OD, CJV060503): 4.90-4.93 (m, 1H, H-1), 5.81- 5.84 (dt, 1H, J _3,1 = 1.9, J _3,2 = 10.1, J _3,4 = 1.9, H-3), 6.09-6.12 (dt, _{1H, J 2,1 = 2.9, J} 2,3 = 10.1, J 2,4 = 2.9, H-2); - ESIHRMS calculated ^{_{C 16 H 22 NO 11 S -}} : 436.0919 , Measured value: m / z 436.00928 [M−H] ⁻ (160212-CJV051301).

[Synthesis of Compounds (7a) and (7b) and Compounds (8a) and (8b)]
The compounds (5a) and (5b) and the compound (6b) obtained above were mixed in a molar ratio of about 4: 5: 1 (10 mg) and suspended in 0.1M sodium hydroxide in methanol at 20 ° C., Stir for 12 hours. Next, the pH of the reaction solution was neutralized with acetic acid, the resulting solution was filtered through a cation exchange resin (Amberlite IR120H), and the solvent was concentrated under reduced pressure. The residue is purified by high performance liquid chromatography (column: Inertsil ODS-3 semi-preparative column 10 × 250 mm, manufactured by GL Sciences; detection wavelength 210 nm, mobile phase: 15% methanol aqueous solution + about 40 mM ammonium acetate, 1 mL / min). Compound (7a) and (7b) and compound (8b) were obtained.

Analytical values of the synthesized compound (7a) are shown below.
(7a) (1R-anomer, equatorial sulfonic acid, CJV054801). Rf = 0.13 (acetone: 1-butanol: H ₂ O = 7: 2.7: 0.3); ¹ H-NMR (600 MHz, CD ₃ OD): 1.76-1.82 (q, 1H , J _{2ax, 1} = 12, J _{2ax, 2eq} = 12, J _{2ax , 3} = 12, H-2ax), 2.00 (s, 3H, NAc), 2.43-2.46 (ddd, 1H, J _{2eq, 1} = 2.2 Hz, J _{2eq, 2ax} = 12.7, J _{2eq, 3} = 4.8, H-2eq), 3.46-3.47 (d, 1H, J = 8.8, J = 0.9 Hz, H-6), 3.62-3.65 (m, 2H, H-5, H-8), 3.74-3.89 (m, 4H, H-3, H- 4, H-7, H-8 ′), 4.26-4.29 (dd, 1H, J _1,2ax = 11.7, J _1,2eq = 2.1 HZ, H-1); -ESIHRMS calculation The value ^{_{C 10 H 18 NO 9 S -}} : 328.0708, Found ^{: M / z318.0724 [M-H} ] - (160303-CJV052802).

Analytical values of the synthesized compound (7b) are shown below.
(7b) (1S-anomer, axial sulfonic acid, CJV052033, CJV060401). Rf = 0.16 (acetone: 1-butanol: H ₂ O = 7: 2.7: 0.3); [α] D24.8 = −0.33 (c = 1 cm, H ₂ O); ¹ H NMR (600 MHz, CD ₃ OD): 1.89-1.95 (ddd, 1H, J 2ax _{, 1} = 7, J _{2ax, 2eq} = 14, J _{2ax , 3} = 10.9, H-2ax), 2.01 (s, 3H, NAc), 2.61-2.64 (ddd, 1H, _{J2eq, 1} = 0.7, _{J2eq, 2ax} = 14, _{J2eq, 3} = 5.5, H- 2eq), 3.43-3.45 (dd, 1H, J _6,5 = 1.2, J _6,7 = 9.1, H-6), 3.57-3.60 (m, 1H, H-8), 3.74-3.77 (t , 1H, J 4,3 = 10.1, J 4,5 = 10.1, H-4), 3.79-3.84 (m, 2H, H-7, H- 8 '), 4.24-4.26 (dd, 1H, J 5,4 = 1 _{.6, J 5,6 = 1.5Hz, H} -5), 4.38-4.43 (td, 1H, J 3,2ax = 10.3, J 3,2eq = 5.4, J 3, ₄ = 10.3, H-3), 4.70-4.71 (d, 1H, _J1,2ax = 6.7, H-1); ¹³ C-NMR (600 MHz, CDCl ₃ ): 22. 58 (CH ₃ CONH), 34.31 (C-2), 54.29 (C-4), 64.62, 67.15, 70.21, 72.42 and 74.32 (C-3 and C -5~C-8), 86.66 (C -1), 175.35 (CH 3 CONH); - ESIHRMS calculated ^{_{C 10 H 18 NO 9 S -}} : 328.0708, Found: m / z 328. 0725 [M−H] ⁻ (160303-CJV052802).

Analytical values of the synthesized compound (8b) are shown below.
(8b) (1S-anomer, axial sulfonic acid, CJV060702). Rf = 0.34 (acetone: 1-butanol: H ₂ O = 7: 2.7: 0.3); ¹ H-NMR (600 MHz, CD ₃ OD): 1.9 (s, 3H, NAc), 3.49-3.50 (dd, 1H, J _6,5 = 1.5, J _6,7 = 9.1, H-6), 3.60-3.63 (dd, 1H, J _{8, 7} = 6.2, J _{8,8 '} = 11.4, H-8), 3.82-3.85 (dd, 1H, J _{8', 7} = 2.9, J _{8 ', 8} = 11 .4, H-8 ′), 3.90-3.93 (ddd, 1H, J _7,6 = 9.1, J _7,8 = 6.2, J _{7,8 ′} = 2.9, H -7), 4.34-4.36 (dd, 1H, J _5,4 = 9.5, J _5,6 = 1.6, H-5), 4.67-4.69 (dddd, 1H , J _4,1 = 2.3, J _4,2 = 2.3, J _4,3 = 2.3, J _4,5 = 9.5, H-4), 4.95-4.97 ( ddd, _{H, J 1,2 = 2.6, J} 1,3 = 2.6, J 1,3 = 2.6, H-1), 5.92-5.94 (dt, 1H, J 3,1 = 2.1, J _3,2 = 10.3, J _3,4 = 2.1, H-3), 6.12-6.14 (dt, 1H, J _2,1 = 2.8, J _2,3 = 10.3, _J2,4 = 2.8, H-2).

(Measurement equipment and reagents)
NMR data, Agilent Corp. nuclear magnetic resonance apparatus 400MR ⁽¹ H: 400MHz) with ^{NMRSystem600 (1H: 600MHz, 13 C} : 150MHz) was measured in. The chemical shift value (δ) is expressed in ppm, and the residual peaks of chloroform (7.26 ppm) and methanol (3.31 ppm) are the reference values of ¹ H-NMR, chloroform (77.0 ppm) and methanol (49.0 ppm). The residual peak was used as a reference value for ¹³ C-NMR. NMR spin coupling constant (J) is shown in hertz (Hz).

  High resolution mass spectrometry (HRMS) was measured with Agilent 6520 Accurate-MassQ-TOF. Specific rotation was measured with P-2200 manufactured by JASCO Corporation and not corrected. For high performance liquid chromatography, Hitachi L-7100 pump and L-7400 ultraviolet absorption detector were used.

As reagents, 1,2-dichloroethane, methanol, acetic acid, and ethanol manufactured by Wako Pure Chemical Industries, Ltd. were used. Trimethylsilyl trifluoromethanesulfonate and thioacetic acid were manufactured by Tokyo Chemical Industry Co., Ltd. Oxone (registered trademark) manufactured by Aldrich was used. Celite manufactured by Nakarai was used. Deuterated chloroform and deuterated methanol used Cambridge Isotope Laboratory. For the thin layer silica gel chromatography for analysis in which the R _f value was calculated, silica gel 60F254, 0.25 mm thickness, with fluorescent agent manufactured by Merck & Co., Inc. was used. Silica gel 60 (70-230 mesh) manufactured by Merck was used for silica gel chromatography. Sodium hydrogen carbonate, ammonium acetate, sodium chloride, and magnesium sulfate were manufactured by Wako Pure Chemical Industries. Amberlite IR120H manufactured by ChemCruz was used.

(Electricity-induced effect)
Table 1 below shows comparison of ¹³ C-NMR chemical shifts of the compounds (5b) and (7b) according to the present invention, phosphonic acid and carboxylic acid derivatives. As shown in Table 1, from the NMR analysis of the sialic acid derivative in which a sulfo group is bonded to the anomeric position according to the present invention, the anomeric position of the sulfo group is much stronger than the carboxy group and the phosphono group. It turns out that an effect is shown. That is, the sialic acid derivative having a sulfo group bonded to the anomeric position according to the present invention allows sialidase to react simultaneously with noncovalent (electrostatic or hydrophobic interaction) interaction or covalently (reversible and irreversible). ) Inhibits through interaction.

In Table 1, the values of the multiacetylated axial phosphonic acid ethyl ester (axPO ₃ Et ₂ ) shown below were referred to literature values (JACS (2011) 133: 17959-17965). The value of deprotection axial type phosphonic acid shown below (axPO ₃ H) the literature value (Helvetica Chimica Acta (1990) 73 : 1359-1372) with reference to the. In addition, the values of polyacetylated axial carboxylic acid methyl ester (axCO ₂ Me) and deprotected axial carboxylic acid (axCO ₂ H) shown below refer to literature values (Tetrahedron Letters (1988) 29: 3643-3646). did.

(Evaluation of sialidase inhibition)
The inhibition of sialidase (NA) activity of the sialic acid derivative according to the present invention was evaluated using IC ₅₀ and Ki values. IC ₅₀ indicates a 50% inhibitory concentration, and the unit of concentration is μM. The IC _50, the method already reported (e.g., Nature Communications (2013) 4: 1491) was measured by a method of detecting the fluorescence based on.

First, a sialidase inhibitor and sialidase were pre-cultured at room temperature for about 20 minutes. Next, 4-methylumbelliferyl = α-D-sialoside as a substrate was added to the culture solution, and sialidase of influenza virus A / RI / 5 + / 1957 (H2N2) strain and sialidase of Streptococcus 6646K strain (Amsbio) ) Was added to a final concentration of 120 μM, and to sialidase of Clostridium perfringens NanJ (Sigma) to a final concentration of 60 μM. Then, using each of the added solutions, the fluorescence (Ex. 355 nm, Em. 460 nm) of the released 4-methylumbelliferone was measured at room temperature with a Thermo Scientific Varioskan (registered trademark) flash microplate reader, and the IC Asked ₅₀ .

The Ki value was evaluated using the Cheng = Prusoff equation (Ki = IC ₅₀ / (1+ [S] / Km)). Ki represents the binding affinity of the inhibitor, [S] is the concentration of the substrate, and Km is the concentration of the substrate at which the enzyme activity is half of the maximum value. The sialidase Km of the influenza virus A / RI / 5 + / 1957 (H2N2) strain was 46.5 μM from the literature value (Nature Communications (2013) 4: 1491).

Table 2 below shows the inhibition of sialidase (N2) of influenza virus A / RI / 5 + / 1957 (H2N2) strain, sialidase (CpNA) of Clostridium perfringens and sialidase (S6NA) of Streptococcus 6646K strain in the anomeric position. IC ₅₀ values and Ki values of sialic acid derivatives (7a), (7b) and (8b) to which is bonded are shown together with comparative examples (eqPO ₃ H) obtained by the same method as in this evaluation example (excluding S6NA). It was. In the table, parentheses indicate statistical confidence intervals.

As shown in Table 2, the sialic acid derivative having a sulfo group according to the present invention has a smaller IC ₅₀ and a stronger sialidase inhibitory activity than those having a phosphono group.

FIG. 2 shows the sialidase inhibitory activity of a sialic acid derivative having a sulfo group bonded to the anomeric position. These are sialic acid derivatives (7a) in which a sulfo group is bonded to the anomeric position for 4-methylumbelliferyl = α-D-sialosidic acid hydrolysis reaction of influenza virus A / RI / 5 + / 1957 (H2N2) strain, (7b), (8b) and eqPO ₃ H inhibitory activity.

FIG. 3 shows the sialidase inhibitory activity of a sialic acid derivative having a sulfo group bonded to the anomeric position. These are for 4-methylumbelliferyl = alpha-D-sialoside acid hydrolysis reaction of sialidase Clostridium perfringens, an inhibitory activity of the anomeric sialic acid derivative is a sulfo group bonded to (7a) and eqPO ₃ H.

  FIG. 4 shows the sialidase inhibitory activity of a sialic acid derivative having a sulfo group bonded to the anomeric position. These are the inhibitory activities of the sialic acid derivative (7a) having a sulfo group bonded to the anomeric position on the 4-methylumbelliferyl = α-D-sialosidic acid hydrolysis reaction of sialidase of Streptococcus 6646K strain.

Since the sialic acid derivative according to the present invention exhibits an inhibitory effect on the sialidase enzyme of influenza virus, it can be used as a pharmaceutical product for preventing and treating influenza. Moreover, since the sialic acid derivative according to the present invention exhibits an inhibitory effect on bacterial sialidase enzymes, it can also be used as an antibacterial agent.

Claims (8)

Formula (I):
[In Formula (I), (A) and (B) each independently represent R ¹ , SO ₃ R ² or SO ₂ R ² . Here, R ¹ is a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom or OAc, and R ² is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group having 1 to 20 carbon atoms, or When (A) is SO ₃ R ² or SO ₂ R ² , (B) is R ¹ , and (B) is SO ₃ R ² or SO ₂ R ² , A) is R ¹ . (C) and (D) represent R ¹ , (E) represents a hydroxy group, an amino group or NHC (═NH) NH ₂ , and (F) represents a hydrogen atom, C (═O) CH ₃ or C (═O) CF ₃ is represented, and R ⁶ , R ⁷ and R ⁸ each independently represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms or C (═O) CH ₃ . ] The sialic acid derivative characterized by the above-mentioned. General formula (II):
[In Formula (II), (A) and (B) each independently represents R ¹ , SO ₃ R ² or SO ₂ R ² . Here, R ¹ is a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom or OAc, and R ² is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group having 1 to 20 carbon atoms, or When (A) is SO ₃ R ² or SO ₂ R ² , (B) is R ¹ , and (B) is SO ₃ R ² or SO ₂ R ² , A) is R ¹ . (F) represents a hydrogen atom, C (═O) CH ₃ or C (═O) CF ₃ , and R ⁶ , R ⁷ and R ⁸ are each independently a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. Alternatively, C (═O) CH ₃ is represented. ] The sialic acid derivative characterized by the above-mentioned.   The sialic acid derivative according to claim 1 or 2, wherein (A) is a sulfo group.   The sialic acid derivative according to claim 1 or 2, wherein (B) is a sulfo group.   A sialidase inhibitor comprising the sialic acid derivative according to any one of claims 1 to 4 as an active ingredient.   An antibacterial agent comprising the sialic acid derivative according to any one of claims 1 to 4 as an active ingredient.   An antiviral agent comprising the sialic acid derivative according to any one of claims 1 to 5 as an active ingredient. In the manufacturing method of the sialic acid derivative of Claim 1 or Claim 2,
The following formulas (3a) 1R and (3b) 1S:
And / or the following formulas (4a) 1R and (4b) 1S:
Are each oxidized using an oxidizing agent,
The following formulas (5a) 1R and (5b) 1S:
And / or the following formulas (6a) 1R and (6b) 1S:
A process for obtaining a compound represented by the formula: