Water-soluble compounds for detecting beta-amyloid

Abstract

The present invention relates to a water-soluble compound for detecting beta-amyloid and a preparation method thereof. The compound of the present invention has excellent water solubility, and thus can provide a water-soluble preparation for detecting beta-amyloid. Therefore, the compound can be used as a composition for detecting beta-amyloid by retinal imaging.

Description

Technical Field

[0001] This invention relates to a compound for detecting β-amyloid protein (Aβ) and a method for preparing the same.

[0002] Specifically, the present invention relates to water-soluble imaging agents and methods for preparing the same. Background Technology

[0003] With the development of modern medicine, the global elderly population is increasing, and consequently, the number of patients suffering from dementia is also rapidly rising. Alzheimer's disease is the most common form of dementia and is a progressive neurodegenerative disease characterized by memory loss, cognitive and behavioral instability. The cause of the disease is still unclear, but as a result of analysis of post-mortem brain tissue from patients, the accumulation of amyloid plaques composed of beta-amyloid (Aβ) peptides between nerve cells and neurofibrillary tangles formed by hyperphosphorylated tau protein filaments in nerve cells have been reported.

[0004] The 39 to 43 amino acids, including β-amyloid peptide (Aβpeptide), are derived from the larger amyloid precursor protein (APP). In the pro-amyloid pathway, β-amyloid peptide is cleaved from APP due to successive proteolytic reactions by β- and γ-secretases. β-amyloid peptide is released as a soluble protein and can be detected at low levels in the cerebrospinal fluid (CSF) of a normally aging brain. It is known that β-amyloid peptide aggregates to form amyloid deposits in the brain or blood vessels during the progression of Alzheimer's disease. Furthermore, amyloid protein deposits are known to play a role in amyloidosis, a disease caused by the abnormal deposition of amyloid proteins in various organs and / or tissues.

[0005] Therefore, in order to diagnose diseases that can be diagnosed by quantitative detection of amyloid aggregates, including Alzheimer's disease, many fluorescent compounds have been studied that bind well to β-amyloid aggregates and readily indicate their presence.

[0006] Among the Alzheimer's disease diagnostic agents developed in related fields, positron emission tomography (PET) imaging agents and optical imaging agents used to detect β-amyloid protein account for the majority.

[0007] As a technique for detecting β-amyloid protein, a protein that causes Alzheimer's disease, recent attempts to detect β-amyloid in the retina of the eye have continued in related fields using brain imaging-based techniques. For example, in the United States, clinical trials for diagnosing Alzheimer's disease through retinal imaging are underway.

[0008] For retinal imaging, the most effective approach is to develop an injectable form of β-amyloid diagnostic agent, which is then injected into the bloodstream. However, existing diagnostic agents for detecting β-amyloid are designed to cross the blood-brain barrier (BBB) ​​and are therefore designed to retain their lipid-soluble properties. Due to these properties, it is difficult to prepare a water-soluble injectable formulation for the detection and diagnosis of β-amyloid via retinal imaging when using existing diagnostic agents.

[0009] Therefore, it is necessary to develop new diagnostic agents for β-amyloid protein, which can be used to prepare water-soluble injectable formulations for the detection and diagnosis of β-amyloid protein via retinal imaging. Summary of the Invention

[0010] Technical issues

[0011] The purpose of this invention is to provide a compound for detecting β-amyloid protein and a method for preparing the same.

[0012] Specifically, the present invention aims to provide a compound for detecting β-amyloid protein and a method for preparing the same, the compound being applicable to water-soluble injectable formulations.

[0013] Furthermore, another object of the present invention is to provide a method for detecting β-amyloid protein using a water-soluble compound for detecting β-amyloid protein.

[0014] Technical solution

[0015] To achieve the above objectives, the present invention provides a compound represented by chemical formula 1 or a pharmaceutically acceptable salt thereof.

[0016] [Chemical Formula 1]

[0017]

[0018] In chemical formula 1,

[0019] Y is either S or O.

[0020] A is a functional group derived from aminoaryl compounds.

[0021] R1 and R2 are each independently hydrogen or C1 to C2. 10 alkyl,

[0022] x is an integer from 1 to 10, and

[0023] n and m are each an independent integer of 0 or greater, and n+m≥1.

[0024] Furthermore, the present invention provides a composition for detecting β-amyloid protein, the composition containing the above-described compound or a pharmaceutically acceptable salt thereof.

[0025] Furthermore, the present invention provides a method for detecting β-amyloid protein, the method comprising: mixing the above-mentioned compound or a pharmaceutically acceptable salt thereof with a sample containing β-amyloid protein; and measuring the fluorescence signal of β-amyloid protein.

[0026] Beneficial effects

[0027] The compounds of this invention exhibit excellent selective binding to β-amyloid protein, and are therefore effective in detecting β-amyloid protein using PET imaging, optical imaging, and / or PET-MRI fusion imaging methods. Consequently, these compounds can be used as compositions for detecting β-amyloid protein and diagnosing diseases caused by excessive β-amyloid protein production.

[0028] In particular, the compound according to the invention has excellent water solubility, and therefore can provide a water-soluble formulation for the detection of β-amyloid protein. Thus, this compound can be used as a composition for the detection of β-amyloid protein via retinal imaging. Attached Figure Description

[0029] The following figures accompanying this specification illustrate preferred embodiments of the invention and are used to further understand the technical concept of the invention and the above-described content of the invention. Therefore, the invention should not be construed as being limited to the contents shown in these figures.

[0030] Figure 1 The chemical structure of Formula 1 of the present invention is shown to be characteristic;

[0031] Figure 2 The results of measuring the absorbance of compounds 1, 2, 4 and 5 according to one embodiment are shown;

[0032] Figure 3 The fluorescence spectra of compounds 1, 2, 4, and 5 before and after binding to β-amyloid protein are shown according to one embodiment; and

[0033] Figure 4 A retinal imaging experiment using compound 1 according to Example 1 is shown. Detailed Implementation

[0034] like Figure 1 As shown, the compounds of the present invention have structural features including a fluorescent signal portion, a β-amyloid binding portion bound to the fluorescent signal portion, and a water-soluble imparting portion. In particular, when the compounds of the present invention are formulated into water-soluble compositions, the inclusion of the water-soluble imparting portion ensures the stability of the composition. Furthermore, water-soluble compositions using these compounds can be characterized as retinal imaging agents.

[0035] The present invention will now be described in detail.

[0036] The present invention provides a compound represented by chemical formula 1 or a pharmaceutically acceptable salt thereof.

[0037] [Chemical Formula 1]

[0038]

[0039] In chemical formula 1,

[0040] Y is either S or O.

[0041] A is a functional group derived from aminoaryl compounds.

[0042] R1 and R2 are each independently hydrogen or C1 to C2. 10 alkyl,

[0043] x is an integer from 1 to 10, and

[0044] n and m are each an independent integer of 0 or greater, and n+m≥1.

[0045] In one implementation, Y is S.

[0046] In another implementation, Y is O.

[0047] In one embodiment, the aminoaryl compound may be at least one selected from the group consisting of aniline, phenylpiperazine and their derivatives.

[0048] Specifically, the aminoaryl compound may be an N-substituted aniline or an N,N-substituted aniline. Here, the substituent at the N-position of the aniline may be independently selected from C1 to C6 straight-chain, branched, and cyclic saturated aliphatic hydrocarbon groups and C1 to C6 unsaturated aliphatic hydrocarbon groups, and may be, for example, independently selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, isobutyl, n-pentyl, isopentyl, tert-pentyl, n-hexyl, vinyl, allyl, propynyl, butenyl, pentenyl, hexenyl, hexadienyl, isopropenyl, isohexenyl, cyclohexenyl, cyclopentadienyl, ethynyl, propynyl, penynyl, hexynyl, isohexynyl, cyclohexynyl, cyclopentyl, and cyclohexyl.

[0049] More specifically, the aminoaryl compound may be N-methylaniline or N,N-dimethylaniline.

[0050] In another implementation, R1 and R2 can each be independently C1 to C 10 alkyl.

[0051] Specifically, R1 and R2 can each be independently C1 to C6 alkyl or C1 to C3 alkyl.

[0052] More specifically, R1 and R2 can each be methyl.

[0053] In another implementation, x can be an integer from 1 to 9, an integer from 1 to 8, an integer from 1 to 7, an integer from 1 to 6, an integer from 1 to 5, an integer from 2 to 6, or an integer from 3 to 5.

[0054] Specifically, x can be 4.

[0055] In another implementation, n and m can each be an integer from 0 to 10 independently.

[0056] Specifically, n and m can each be an integer from 0 to 9, an integer from 0 to 8, an integer from 0 to 7, an integer from 0 to 6, an integer from 0 to 5, an integer from 0 to 4, an integer from 0 to 3, or an integer from 0 to 2.

[0057] More specifically, within the range that n+m≥1, n can be an integer of 0 or 1, and m can be an integer of 0, 1 or 2.

[0058] According to one embodiment, the chemical structural formulas of compounds mentioned in the examples as compounds represented by chemical formula 1 are summarized in Table 1 below.

[0059] [Table 1]

[0060]

[0061]

[0062]

[0063] Compounds represented by Formula 1 may be used in the form of pharmaceutically acceptable salts, and said salts may be acid addition salts formed using pharmaceutically acceptable free acids. Acid addition salts are obtained from inorganic acids such as hydrochloric acid, nitric acid, phosphoric acid, sulfuric acid, hydrobromic acid, hydroiodic acid, nitrous acid, and phosphorous acid; non-toxic organic acids such as aliphatic monocarboxylic acid esters and dicarboxylic acid esters, phenyl-substituted alkanes, hydroxyalkanes and alkanedic acid esters, aromatic acids and aliphatic and aromatic sulfonic acids; and organic acids such as acetic acid, benzoic acid, citric acid, lactic acid, maleic acid, gluconic acid, methanesulfonic acid, 4-toluenesulfonic acid, tartaric acid, and fumaric acid. Examples of pharmaceutically non-toxic salts include sulfates, pyrosulfates, bisulfates, sulfites, bisulfites, nitrates, phosphates, monohydrogen phosphates, dihydrogen phosphates, metaphosphates, pyrophosphate chlorides, bromides, iodides, fluorides, acetates, propionates, decanoates, octanoates, acrylates, formates, isobutyrates, decanoates, heptanoates, propynylates, oxalates, malonates, succinates, octanoates, sebacic acid, fumarates, maleates, and butyn-1,4-dicarboxylic acid. Salts, hexane-1,6-diacidates, benzoates, chlorobenzoates, methyl benzoate, dinitrobenzoate, hydroxybenzoate, methoxybenzoate, phthalates, terephthalates, benzenesulfonates, toluenesulfonates, chlorobenzenesulfonates, xylenesulfonates, phenyl acetate, phenyl propionate, phenyl butyrate, citrate, lactate, β-hydroxybutyrate, glycolate, malate, tartrate, methanesulfonate, propanesulfonate, naphthalene-1-sulfonate, naphthalene-2-sulfonate, and mandelate.

[0064] The acid addition salt of the present invention can be prepared by conventional methods, and can be prepared by, for example, dissolving the compound represented by Formula 1 in an organic solvent such as methanol, ethanol, acetone, dichloromethane or acetonitrile, adding an organic or inorganic acid to form a precipitate, and filtering and drying the precipitate, or by vacuum distilling the solvent and excess acid and drying the product, and crystallizing the product in an organic solvent.

[0065] Furthermore, alkalis can be used to prepare pharmaceutically acceptable metal salts. Alkali metal or alkaline earth metal salts are obtained, for example, by dissolving the compound in an excess of an alkali metal hydroxide or alkaline earth metal hydroxide solution, filtering the undissolved salt, and evaporating and drying the filtrate. Here, preparing sodium, potassium, or calcium salts as metal salts is pharmaceutically suitable. Additionally, the corresponding salts are obtained by reacting the alkali metal or alkaline earth metal salt with a suitable negative salt (e.g., silver nitrate).

[0066] Furthermore, the present invention includes not only compounds represented by chemical formula 1 and their pharmaceutically acceptable salts, but also solvates, hydrates, etc., that can be prepared therefrom.

[0067] The β-amyloid protein detection composition of the present invention contains the above-mentioned compound or a pharmaceutically acceptable salt thereof.

[0068] In this specification, "β-amyloid" refers to the main component of amyloid plaques found in the brains of Alzheimer's disease patients, and is a peptide of 36 to 43 amino acids closely related to Alzheimer's disease.

[0069] In this specification, “β-amyloid plaque” refers to the aggregated state of various insoluble fibrous proteins deposited in patient tissues, and β-amyloid plaque includes aggregates formed by aggregated amyloid proteins and / or amyloid deposits formed by other combinations of amyloid proteins.

[0070] In this specification, “detection of β-amyloid plaques” or “diagnosis of diseases caused by excessive production of β-amyloid plaques” is performed using the binding between β-amyloid protein and / or β-amyloid plaques and a compound represented by chemical formula 1 according to the present invention or a pharmaceutically acceptable salt thereof, and “binding” means chemical interaction, such as covalent bond, ionic bond, hydrophilic-hydrophilic interaction, hydrophobic-hydrophobic interaction and complex compound bond.

[0071] In this specification, "diseases caused by excessive production of β-amyloid plaques" may include dementia, Alzheimer's disease, Down syndrome, amyloid angiopathy, cerebral amyloid angiopathy, systemic amyloidosis, Dutch amyloidosis, inclusion body myositis, Mediterranean fever, Muckle-Wells syndrome, idiopathic myeloma, amyloid polyneuropathy, amyloid cardiomyopathy, systemic senile amyloidosis, hereditary cerebral hemorrhage with amyloidosis, pruritus, Creutzfeldt-Jakob disease, kuru, Gerstmann-Straussler-Scheinker syndrome, medullary thyroid carcinoma, myasthenia gravis, and type II diabetes mellitus.

[0072] In one embodiment, the "detection composition" can be formulated as an imaging agent, such as a PET imaging agent, an optical imaging agent that uses light in the visible or near-infrared range generated in vivo as an image signal, or a PET-MRI fusion imaging agent, and then used in a PET imaging method, an optical imaging method, or a PET-MRI fusion imaging method. When formulating the composition, it may further include a pharmaceutically acceptable carrier, if desired.

[0073] The detection compositions of the present invention can be administered orally or parenterally in clinical administration and can be used in conventional formulations. The compositions may further contain pharmaceutically acceptable carriers or additives, and formulations can be prepared using commonly used fillers, extenders, binders, wetting agents, disintegrants, diluents such as surfactants, or excipients when formulating the compositions.

[0074] In one embodiment, the compound exhibits water solubility, therefore the composition may contain water as a solvent. Thus, the composition can be formulated as a water-soluble injection, but the invention is not limited thereto.

[0075] The method for detecting β-amyloid protein of the present invention includes the steps of mixing the compound of the present invention or a pharmaceutically acceptable salt thereof with a sample containing β-amyloid protein, and measuring the fluorescence signal of β-amyloid protein.

[0076] In one embodiment, the present invention provides a method for detecting β-amyloid protein by PET imaging, the method comprising the steps of mixing a compound of the present invention or a pharmaceutically acceptable salt thereof with a sample containing β-amyloid protein, and measuring the fluorescence signal of β-amyloid protein.

[0077] In another embodiment, the present invention provides a method for detecting β-amyloid protein by optical imaging, the method comprising the steps of mixing a compound according to the invention or a pharmaceutically acceptable salt thereof with a sample containing β-amyloid protein, and measuring the fluorescence signal of β-amyloid protein.

[0078] In another embodiment, the present invention provides a method for detecting β-amyloid protein by PET-MRI fusion imaging, the method comprising the steps of mixing a compound of the present invention or a pharmaceutically acceptable salt thereof with a sample containing β-amyloid protein, and measuring the fluorescence signal of β-amyloid protein.

[0079] Herein, the compound represented by chemical formula 1 according to the present invention or its pharmaceutically acceptable salt exhibits high binding affinity for β-amyloid and / or β-amyloid plaques and forms specific binding.

[0080] The step of administering the composition to a subject can be performed by introducing a detectable amount of the composition containing the compound according to the invention or a pharmaceutically acceptable salt thereof into a tissue or subject. This is done using methods known to those skilled in the art.

[0081] The term "tissue" refers to a part of the subject's body. Examples of tissues may include the retina, blood vessels, brain, heart, liver, and arteries. "Detectable amount" is the amount of composition that needs to be detected by the selected detection method. Those skilled in the art can readily determine the amount of composition introduced into a patient for detection. For example, the amount of composition may be increased and administered to the subject until the active ingredient in the composition is detected by the selected detection method. The term "subject" refers to a human or another animal. Those skilled in the art can readily determine the time required for the compound according to the invention to bind to amyloid aggregates by introducing the above-described composition into a subject in a detectable amount and then detecting the marker substance at different time points after administration.

[0082] The assay composition of the present invention can be administered to subjects via systemic or local routes of administration. For example, the composition can be administered orally, rectally, parenterally (intravenously, intramuscularly, or subcutaneously), intracerebrospinally, intravaginally, intraperitoneally, intrabladderly, or locally (as a powder, ointment, or drops), or via buccal or nasal spray. The composition can be given to the subject in a manner that allows it to migrate through the body. Furthermore, the composition can be applied to specific organs or tissues of interest.

[0083] In a method for detecting β-amyloid aggregates generated by administering a detection composition, a composition containing the compound of the present invention or a pharmaceutically acceptable salt thereof is introduced into a subject in a detectable amount. After sufficient time for the compound to bind to the amyloid aggregates, a fluorescently labeled substance in the subject can be detected non-invasively. Further, a tissue sample is separated from the subject, and the above composition is introduced into the tissue sample. After sufficient time for the compound in the composition or a pharmaceutically acceptable salt thereof to bind to the amyloid aggregates, a fluorescently labeled substance can be detected.

[0084] When the detection composition according to the invention is used, it can demonstrate the useful effect of detecting β-amyloid protein via recently developed retinal imaging. Therefore, retinal imaging may provide an important means for the diagnosis and treatment of diseases caused by excessive production of β-amyloid plaques, particularly for the early diagnosis and monitoring of Alzheimer's disease.

[0085] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0086] Example 1: Synthesis of Compound 1

[0087] Compound 1: (E)-3-(2,4-(dimethylamino)styryl)-1,1-dimethyl-1H-benzo[e]indole-3-cation-3-yl)butane-1-sulfonate ion

[0088]

[0089] To synthesize compound 1, compound 7 (43 mg, 0.289 mmol) and compound 8 (100 mg, 0.289 mmol) were dissolved in butanol, and the product was refluxed at 130 °C for 24 hours. The reactants were concentrated under reduced pressure and then separated by chromatography (CH2Cl2:MeOH = 5:1) to synthesize compound 1.

[0090] 1 H NMR (500MHz, MeOH-d4, δ, ppm): 1.80-1.83 (2H, m), 1.93-1.96 (8H, m), 2.51-2.52 ( 2H,m),3.13(6H,s),4.60-4.63(2H,m),6.85(2H,d,J=9.0Hz),7.37(1H,d,J=15.5H z),7.61(1H,t,J=7.0Hz),7.72(1H,t,J=7.0Hz),7.99(1H,d,J=8.0Hz),8.12(2H, d,J=8.0Hz), 8.17(1H,d,J=9.0Hz), 8.32(1H,d,J=8.5Hz), 8.38(1H,d,J=15.5Hz).

[0091] Example 2: Synthesis of Compounds 2 and 3

[0092] Compound 2: (E)-4-(2-(2-(5-(4-(dimethylamino)phenyl)thiophene-2-yl)vinyl)-1,1-dimethyl-1H-benzo[e]indole-3-cation-3-yl)butane-1-sulfonate ion

[0093] Compound 3: (E)-4-(2-(2-(5′-(4-(dimethylamino)phenyl)-[2,2′-bithiophene]-5-yl)vinyl)-1,1-dimethyl-1H-benzo[e]indole-3-cation-3-yl)butane-1-sulfonate ion

[0094]

[0095] Compound 11 (167 mg, 0.7 mmol) and Pd(PPh3)4 (80 mg, 0.07 mmol) were dissolved in toluene (10 mL). Compound 9 or 10 (0.7 mmol) was dissolved in EtOH (8 mL), and the product was added to the mixture. Additionally, 2 M K2CO3 (2 mL) was added, and the product was refluxed at 120 °C for 5 hours, followed by concentration under reduced pressure. The resulting mixture was separated by chromatography (hexane:ethyl acetate = 4:1) to synthesize compound 12 or 13.

[0096] Compound 12 or 13 (0.289 mmol) and compound 8 (100 mg, 0.289 mmol) were dissolved in butanol, and the products were refluxed at 130 °C for 24 hours. The reactants were concentrated under reduced pressure and then separated by chromatography (CH2Cl2:MeOH = 5:1) to synthesize compound 2 or 3.

[0097] Compound 2: 1 H NMR(500MHz,MeOH-d4,δ,ppm):2.04-20.9(8H,m),2.18-2.19(2H,m),2.93-2.96(2H,m ),3.06(6H,s),4.64-4.67(2H,m),6.80(2H,d,J=8.5Hz),7.13(1H,d,J=15.5Hz),7.63 (1H,t,J=4.0Hz),7.70-7.76(3H,m),7.92(1H,d,J=8.5Hz),7.96(1H,d,J=4.0Hz),8.0 9(1H,d,J=8.5Hz),8.17(1H,d,J=9.5Hz),8.35(1H,d,J=8.0Hz),8.65(1H,d,J=15.5Hz)

[0098] Compound 3: 1 H NMR(500MHz,DMSO-d6,δ,ppm):1.81-1.84(2H,m),2.0-2.01(8H,m),2.54-2.57(2H,m),2.97(6 H,s),4.72-4.75(2H,m),6.78(2H,d,J=9.0Hz),7.35(1H,d,J=15.8Hz),7.42(1H,d,J=3.9Hz), 7.55(2H,d,J=8.9Hz),7.62-7.64(2H,m),7.67-7.71(1H,m),7.77-7.80(1H,m),8.12(1H,d,J= 9.0Hz),8.19(1H,d,J=8.1Hz),8.23-8.26(2H,m),8.40(1H,d,J=8.1Hz),8.72(1H,d,J=15.7Hz)

[0099] Example 3 Synthesis of Compound 4

[0100] Compound 4: (E)-4-(1,1-dimethyl-2-(4-(piperazin-1-yl)styryl)-1H-benzo[e]indol-3-cation-3-yl)butane-1-sulfonate ion

[0101]

[0102] Compound 14 (84 mg, 0.289 mmol) and compound 8 (100 mg, 0.289 mmol) were dissolved in butanol, and the products were refluxed at 130 °C for 24 hours. The reactants were concentrated under reduced pressure and then separated by chromatography (CH₂Cl₂:MeOH = 5:1) to synthesize compound 15. Compound 15 was dissolved in CH₂Cl₄, TFA was added, and the mixture was stirred at room temperature for 12 hours to give compound 4.

[0103] 1 H NMR(500MHz,MeOH-d4,δ,ppm):1.82-1.83(2H,m),1.97-1.99(8H,m),2.53-2.54( 2H,m),3.22-3.24(2H,m),3.69-3.71(2H,m),4.69-4.72(2H,m),7.12(2H,d,J=9. 0Hz),7.53(1H,d,J=15.5Hz),7.65(1H,t,J=7.0Hz),7.75(1H,t,J=7.0Hz),8.05( 1H, d, J = 8.0Hz), 8.15-8.22 (4H, m), 8.35 (1H, d, J = 8.5Hz), 8.43 (1H, d, J = 15.5Hz).

[0104] Example 4: Synthesis of Compounds 5 and 6

[0105] Compound 5: (E)-4-(1,1-dimethyl-2-(2-(5-(4-(methylamino)phenyl)thiophene-2-yl)vinyl)-1H-benzo[e]indol-3-cation-3-yl)butane-1-sulfonate ion

[0106] Compound 6: (E)-4-(1,1-dimethyl-2-(2-(5′-(4-(methylamino)phenyl)-[2,2′-bithiophene]-5-yl)vinyl)-1H-benzo[e]indol-3-cation-3-yl)butane-1-sulfonate ion

[0107]

[0108] Compound 16 (1 g, 5.43 mmol) was dissolved in THF, and Boc anhydride (2.36 g, 10.86 mmol) was added. The mixture was refluxed at 80 °C for 12 hours, and then concentrated under reduced pressure. The mixture was separated by chromatography (hexane:ethyl acetate = 9:1) to synthesize compound 17.

[0109] Compound 17 (200 mg, 0.7 mmol) and Pd(PPh3)4 (80 mg, 0.07 mmol) were dissolved in toluene (10 mL). Compound 9 or 10 (0.7 mmol) was dissolved in EtOH (8 mL), and the product was added to the mixture. Additionally, 2 M K2CO3 (2 mL) was added, and the product was refluxed at 120 °C for 5 hours, followed by concentration under reduced pressure. The resulting mixture was separated by chromatography (hexane:ethyl acetate = 4:1) to synthesize compounds 18 or 19.

[0110] Compound 18 or 19 (0.289 mmol) and compound 8 (100 mg, 0.289 mmol) were dissolved in butanol, and the products were refluxed at 130 °C for 24 hours. The reactants were concentrated under reduced pressure and then separated by chromatography (CH₂Cl₂:MeOH = 5:1) to synthesize compound 20 or 21. Compound 20 or 21 was dissolved in CH₂Cl₂, TFA was added, and the mixture was stirred at room temperature for 12 hours to give compound 5 or 6.

[0111] Compound 5: 1 H NMR(500MHz,MeOH-d4,δ,ppm):2.01-2.05(8H,m),2.16-2.19(2H,m),2.93-2.96(2H,m),3.2 9(3H,s),4.64-4.67(2H,m),6.85(2H,d,J=8.5Hz),7.15(1H,d,J=15.5Hz),7.53(1H,d,J=4. 0Hz),7.63(1H,t,J=7.5Hz),7.71-7.76(3H,m),7.92(1H,d,J=8.5Hz),7.96(1H,d,J=4.0Hz) ,8.09(1H,d,J=8.5Hz),8.15(1H,d,J=9.5Hz),8.35(1H,d,J=8.0Hz),8.62(1H,d,J=15.5Hz)

[0112] Compound 6: 1H NMR(500MHz,DMSO-d6,δ,ppm):1.81-1.83(2H,m),2.0-2.01(8H,m),2.54-2.57(2H,m),2.96(3 H,s),4.71-4.73(2H,m),6.77(2H,d,J=9.0Hz),7.34(1H,d,J=15.8Hz),7.41(1H,d,J=3.9Hz), 7.52(2H,d,J=8.9Hz),7.61-7.63(2H,m),7.67-7.71(1H,m),7.78-7.80(1H,m),8.11(1H,d,J= 9.0Hz), 8.18 (1H, d, J = 8.1Hz), 8.24-8.27 (2H, m), 8.41 (1H, d, J = 8.1Hz), 8.72 (H, d, J = 15.7Hz)

[0113] Experimental Example 1: Determination of the absorbance of a compound

[0114] The maximum excitation and emission wavelengths λ of compounds 1, 2, 4 and 5 of this invention max Measurements were taken using a SpectraMax M2 (Molecular Devices). 10 μM of Aβ42 fibrils and 5 μM of each compound produced by the above method were used as the final concentrations for use in PBS buffer. Typically, the excitation λ is determined by scanning the immobilized first emission. max And by using a fixed λ max Scanning the excitation spectrum to determine the emission λ max .

[0115] The absorbance of the synthesized compounds 1, 2, 4, and 5 was measured, and the results are as follows: Figure 2 As shown.

[0116] Activity evaluation after binding with β-amyloid protein in Experiment Example 2

[0117] For compounds 1, 2, 4, and 5 synthesized above, their activities before and after binding with β-amyloid protein were evaluated, and the results are as follows: Figure 3 As shown. In Figure 3 In the upper right rectangles, one of compounds 1, 2, 4, and 5 (before binding) is shown as a dark gray area, and one of compounds 1, 2, 4, and 5 (bound to β-amyloid: "Aβ42 aggregate") is shown as a light gray area (these grays are equivalent to red in the actual fluorescence image).

[0118] Furthermore, the absorption wavelengths of compounds 1, 2, 4, and 5 before and after binding with β-amyloid protein are shown in Table 2 below. As shown in Table 2, it was confirmed that the fluorescence intensity significantly increased when the compounds of the present invention bound to β-amyloid protein. In particular, regarding the fluorescence reactivity to β-amyloid peptide, the Faβ / F0 values ​​of compounds 1, 2, 4, and 5 were 4.3, 11.6, 3.1, and 9.6, respectively, indicating high fluorescence properties (see Table 2 below).

[0119] In addition, from Figure 3 It was confirmed that there was a significant difference in emission wavelength before and after the compound according to the invention bound to amyloid plaques.

[0120] [Table 2]

[0121] Fluorescence properties Compound 1 Compound 2 Compound 4 Compound 5 <![CDATA[λ ex (nm)]]> 560nm 805nm 570nm 575nm <![CDATA[λ em (nm)]]> 620nm 765nm 620nm 760nm Changes in fluorescence intensity (by multiples) after binding to β-amyloid protein. 4.3 11.6 3.1 9.6

[0122] Example 3: Retinal Targeting Experiment in Experimental Mice

[0123] Water-soluble compound 1 (8 mg / kg) was injected into the tail vein of 3-month-old nude mice, and imaging was performed using an IVIS spectrum CT system. The results are as follows: Figure 4 As shown.

[0124] like Figure 4 As shown, a strong fluorescent signal of water-soluble compound 1 was detected in the eyes of nude mice 1 minute after intravenous injection.

[0125] No fluorescence signal was detected in the "control" (no compound was added for detecting β-amyloid), and a weak fluorescence signal of water-soluble compound 1 was detected in the eyes of mice 10 minutes after intravenous injection (sufficient excretion time).

[0126] These results suggest that water-soluble compound 1 can be used for diagnosing diseases caused by abnormal amyloid deposition, such as Alzheimer's disease, through retinal imaging.

Claims

1. Use of a compound represented by any one of the following chemical formulas 2, 3, 5, and 6, or a pharmaceutically acceptable salt thereof, in the preparation of a diagnostic agent for providing information on the detection of β-amyloid protein via retinal imaging: [Chemical Formula 2] [Chemical Formula 3] [Chemical Formula 5] [Chemical Formula 6] 2. Use of a composition comprising a compound represented by any one of the following chemical formulas 2, 3, 5, and 6, or a pharmaceutically acceptable salt thereof, in the preparation of a diagnostic agent for providing information on the detection of β-amyloid protein via retinal imaging: [Chemical Formula 2] [Chemical Formula 3] [Chemical Formula 5] [Chemical Formula 6] 3. The use as described in claim 2, wherein the composition comprises water as a solvent.

4. Use of a composition comprising a compound represented by any one of the following chemical formulas 2, 3, 5, and 6, or a pharmaceutically acceptable salt thereof, in the preparation of a diagnostic agent for providing information for diagnosing Alzheimer's disease via retinal imaging: [Chemical Formula 2] [Chemical Formula 3] [Chemical Formula 5] [Chemical Formula 6]

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