KR20010038149A - Medicine for treating dementia or cognitive disorder, which comprises asiatic acid derivatives - Google Patents

Abstract

PURPOSE: Medicines for treating dementia and cognitive disorder and comprising asiatic acid derivatives are provided, which have an improved effect on treating dementia and cognitive disorder by exhibiting an excellent effect on protecting a brain cell. CONSTITUTION: The medicines for treating dementia and cognitive disorder comprises asiatic acid derivatives represented by the formula 1 and pharmaceutically acceptable salts and esters thereof as an effective component, wherein the effective component is ethoxymethyl-2-oxo-3-deoxyasiatate or ethoxymethyl-3-deoxyasiatate.

Description

Medicine for treating dementia or cognitive disorders, which comprises asiatic acid derivatives}

The present invention relates to pharmaceutical compositions comprising asiatic acid derivatives, and more particularly to therapeutic agents for dementia and cognitive impairment comprising asiatic acid derivatives, pharmaceutically acceptable salts or esters thereof.

Asian acid, its trisaccharides, asiaticoside and madecassic acid, is a substance extracted from Centella asiatica, first isolated in 1941 by Bontems et al. [J.E. Bontems, Bull, Sci. Pharmacol., 49, 186-91, (1941)], the structure was determined by Polonsky et al. J. Polonsky, Compt, Rend., 232, 1878-80 (1951): J. Polonsky, Bull. Soc. Chim., 173-80 (1953)].

Extracts of Centella asiatica, including asiatic acid and asiaticosides, have long been used in the treatment of skin wounds and chronic ulcers, and in the treatment of skin deformation caused by tuberculosis or leprosy [P. Boiteau, A. Buzas, E. Lederer and J. Polonsky, Bull. Soc. Chim., 31, 46-51 (1949)], recently reported by Cochst to have an effect on dementia and cognitive impairment (EP 0 383 171 A2). However, the experimental results introduced in this document suggest that the research for better dementia treatments is required because of the weak efficacy for the treatment of dementia.

Depositional neuronal spots recently found in patients with dementia are known as the cause of dementia disease [B. Hyman, R. E. Tanzi, Curr Op Neurol. Neurosurg, 5, 88, 1992]. The spot consists of a protein called Aβ-amyloid, which is considered to be one of the causes of dementia. I. Lieburg, EH Koo, D. Shenk, DB Teplow, DJ Selkoe, Nature, 359, 322, 1992].

The present inventors found a derivative of asiatic acid that has a therapeutic effect on dementia and cognitive impairment using existing passive avoidance test and a novel Aβ-amyloid toxicity inhibition experiment.

It is an object of the present invention to provide useful therapeutic agents for dementia and cognitive impairment.

The present invention relates to an agent for treating dementia and cognitive impairment comprising an asiatic acid derivative represented by the following Chemical Formula 1, a pharmaceutically acceptable salt or ester thereof.

R <_1> represents hydrogen and a hydroxy group; R ₂ represents hydrogen, a hydroxy group; R ₁ and R ₂ together may form an oxo group; R ₃ represents hydrogen, a hydroxy group; R ₄ represents hydrogen or a hydroxy group; R ₂ and R ₄ together may form an epoxy group; R ₅ represents a hydroxymethyl group, tert-butyldimethylsilyloxymethyl group, carboxyl group, carboxyl ester residue, carboxyl amide residue or aldehyde group in which a methyl group, a hydroxy group may be protected by an acetyl or benzoyl group; R ₄ may form —OCR ₆ R ₇ OCH ₂ — with R ₅ , wherein R ₆ is hydrogen, lower alkyl of 1 to 4 carbon atoms or phenyl, and R ₇ is hydrogen, lower of 1 to 4 carbon atoms Alkyl or phenyl, and R ₆ and R ₇ may together form — (CH ₂ ) ₅ —; R ₈ represents hydrogen or a methyl group; R ₉ is —CH ₂ COOR or —COOR [where R is hydrogen, lower alkyl of 1 to 4 carbon atoms, 2-tetrahydropyranyl, 2-tetrahydrofuranyl, CH (OR ₁₁ ) R ₁₀ (R ₁₀ Is a lower alkyl group having 1 to 4 carbon atoms, R ₁₁ is a lower alkyl group having 1 to 4 carbon atoms, octyl, benzyl, methoxymethyl or methoxyethyl group), or a glucosyl or rhamnosyl group whose hydroxy group may be protected by acetyl or benzoyl. Hydroxy group, methanesulfonyloxymethyl or cyanomethyl group which may be protected by acetyl or benzoyl.

Treatment of the present invention includes the rapid alleviation and prevention of symptoms.

A general method for preparing a compound of Formula 1 of the present invention is disclosed in Korean Patent Application No. 95-46131, but when the definition of Formula 1 is the same as in Formula 2 below, the preparation is preferably synthesized as in the following methods 1-8. .

Wherein R _a represents hydrogen or a hydroxy group; R _b represents hydrogen or a hydroxy group; R _a and R _b together may form an oxo group; R _c represents hydroxy or hydrogen; R _b and R _c together may form an epoxy group; R _d represents hydroxymethyl; R _c may form —OC (R _f ) (R _g ) OCH ₂ — with R _d , where R _f is hydrogen, lower alkyl or phenyl having 1 to 4 carbon atoms, and R _g is hydrogen, carbon number Lower alkyl or phenyl of 1 to 4 and R _f and R _g together may form — (CH ₂ ) ₅ —; R _e represents hydrogen, lower alkyl having 1 to 4 carbon atoms, 2-tetrahydropyranyl, 2-tetrahydrofuranyl, ethoxy-α-ethyl.

Hereinafter, a method for preparing the asiatic acid derivative of Chemical Formula 2 according to the present invention will be described.

<Method 1>

Referring to Scheme 1, first, carboxylic acid No. 28 of asiatic acid (3) is methyl esterified with diazomethane to form compound (4). Thereafter, the hydroxyl groups 3 and 23 of compound (4) are protected with acetonide to form compound (5). The hydroxyl group 2 of compound (5) was protected with methanesulfonyl chloride and then deprotected with dilute hydrochloric acid to give compound (7). Potassium carbonate is then added to the methanol solution of compound (7) to obtain an epoxy compound (8) in which the hydroxy group is epoxidized twice and three times. Subsequently, compound (8) is reduced using lithium borohydride to obtain compound (9), followed by hydrolysis of methyl ester to obtain compound (10).

<Method 2>

Referring to Scheme 2, compound (10) obtained in Method 1 was esterified with ethoxymethyl chloride to make compound (11). Thereafter, only hydroxy group 2 of compound (11) was oxidized to obtain ketone (12), followed by hydrolysis with dilute hydrochloric acid to obtain compound (13).

<Method 3>

Referring to Reaction Scheme 3, acetylated No. 2, 3 and 23 hydroxy groups of Asian acid (3) were obtained to obtain Compound (14), followed by action of dihydropyran, dihydrofuran, and ethyl vinyl ether to remove carboxyl group 28. After protection, hydrolysis with potassium carbonate gives compound (15).

<Method 4>

The hydroxyl groups 3 and 23 of asiatic acid (3) were protected with acetonide to form compound (16), and then ethoxymethyl chloride was added to obtain ester (17). Thereafter, xanthate 18 is obtained using carbon disulfide and methyl iodide. Thereafter, xanthate 18 is reduced with tributyltin hydride to form compound 19, followed by deprotection with dilute hydrochloric acid to obtain compound 20.

Acute toxicity values (LD ₅₀ ) of mice by intraperitoneal administration of the compounds of the invention were relatively safe, 100-250 mg / kg.

The dosage of the compound of Formula 1 is 0.05-50 mg per adult, and the dosage may be varied depending on the age and weight of the patient as well as the severity of symptoms.

The agent for treating dementia and cognitive impairment according to the present invention may be prepared in a form suitable for oral administration or parenteral administration according to a conventional preparation method. That is, in the case of oral administration, it may be prepared in the form of tablets, capsules, solutions, syrups, suspensions, etc., and in the case of parenteral administration, it may be prepared in the form of injections for intraperitoneal, subcutaneous, muscle, and transdermal. .

Hereinafter, the present invention will be described in more detail with reference to Examples, Preparation Examples and Experimental Examples, but the present invention is not limited thereto.

Example 1 Preparation of Methyl Asiatate (4)

5 g of asian acid (3) was dissolved in ether, and a diazomethane ether solution was slowly added dropwise at 0 ° C, and stirred at room temperature for 1 hour. The ether was concentrated under reduced pressure to remove the residue. The residue was purified by column chromatography (hexane: ethyl acetate = 3: 1) to obtain 4.9 g (95%) of methyl asiaate (4).

IR (neat): 344, 1743, 1380 cm ^-1

Mass (EI): m / e 486 (M ⁺ )

¹ H-NMR (CD ₃ OD): δ 2.19, 1.04, 0.99, 0.91 (each s, 3H), 3.43 (m, 2H), 5.25 (m, 1H)

Example 2 Preparation of Methyl 3,23-O-Isopropylidene Asiatate (5)

Methylasiatate (4) (12 g) and p-toluenesulfonic acid (200 mg) were dissolved in anhydrous DMF (100 ml), 2,2-dimethoxypropane (5 ml) was added and stirred at room temperature for 14 hours. The reaction mixture was neutralized and concentrated under reduced pressure to remove the solvent. Extraction, washing and drying were followed by column chromatography (dichloromethane: methanol = 30: 1) to obtain 8.04 g of methyl 3,23-O-isopropylidene asiatate (5).

IR (neat): 3466, 1724, 1201 cm ^-1

Mass (EI): m / e 526 (M ⁺ )

¹ H-NMR (CDCl ₃ ): δ 0.66, 0.97, 1.00, 1.02, 1.40, 1.39 (each s, 3H), 0.79 (d, 3H, J = 6.4 Hz), 0.87 (d, 3H, J = 6.0 Hz ), 2.15 (d, 1H), 3.25 (d, 1H, J = 9.6 Hz), 3.41 3.43 (ABq, 2H), 3.53 (s, 3H), 3.72 (m, 1H), 5.18 (brt, 1H)

Example 3 Preparation of Methyl 2-methanesulfonyl-3,23-O-isopropylidene asiatate (6)

Methyl 3,23-O-isopropylidene asiatate (5) (0.24 g) was dissolved in dichloromethane (13.5 ml), triethylamine (0.35 ml) and methanesulfonylchloride (0.08 ml) were added, and then 0 ° C. Stirred for 1 h. After completion of the reaction, the solvent was removed, extracted with ethyl acetate, washed, dried and separated and purified by column chromatography (hexane: ethyl acetate = 3: 1) to 0.3 g (67%) of methyl 2-methanesulfonyl-3,23 -O-isopropylidene asiatate (6) was obtained.

IR (neat): 3850, 1724, 1173 cm ^-1

Mass (EI): m / e 696 (M +)

¹ H-NMR (CD ₃ OD): 5.28 (m, 1H), 4.65 (m, 1H, J = 4.65 Hz), 3.60 (s, 3H), 2.96 (s, 3H), 1.03, 0.98, 0.88, 0.73 (each s, 3H)

Example 4 Preparation of Methyl 2-methanesulfonyl-O-Asitate (7)

Methyl 2-methanesulfonyl-3,23-O-isopropylidene asiatate (6) (0.3 g) was dissolved in methanol (10 ml), diluted with hydrochloric acid, and stirred for 10 minutes at room temperature. After completion of the reaction, the solvent was removed, extracted with ethyl acetate, washed and dried to obtain 0.2 g (52%) of methyl 2-methanesulfonyl-O-asiatate (7).

IR (neat): 3478, 1721, 1228 cm ^-1

Mass (EI): m / e 657 (M +)

¹ H-NMR (CD ₃ OD): 5.25 (m, 1H), 4.81-4.72 (m, 1H), 4.18-4.06 (m, 2H), 3,72, 3.43 (q, 2H), 3.09 (s, 3H), 2.05 (s, 3H)

Example 5 Preparation of Methyl 2,3-Epoxy-O-Asiatate (8)

Methyl 2-methanesulfonyl-O-asiatate (7) (250 mg) and potassium carbonate (120 mg) were dissolved in methanol (10 ml) and stirred at room temperature for 3 days. After completion of the reaction, the solvent was removed, extracted with dichloromethane, washed, dried and separated and purified by column chromatography (hexane: ethyl acetate = 2: 1) to 214 mg (86%) of methyl 2,3-epoxy-O-Asia. Tate (8) was obtained.

IR (neat): 3850, 1724, 1230 cm ^-1

Mass (EI): m / e 484 (M +)

Example 6 Preparation of Methyl 2-Epihydroxy-3-deoxyasiatate (9)

Methyl 2,3-epoxy-O-asiatate (8) (95 mg), lithium borohydride (17 mg) was dissolved in anhydrous tetrahydrofuran (5 ml) and refluxed for 10 hours. After completion of the reaction, the reaction mixture was evaporated under reduced pressure to remove the solvent, followed by extraction with ethyl acetate, washing and drying to obtain 67 mg (71%) of methyl 2-epihydroxy-3-deoxyasiatate (9).

IR (neat): 3850, 1714, 1033 cm ^-1

Mass (EI): m / e 486 (M +)

¹ H-NMR (CD ₃ OD): 5.27 (m, 1H), 3.38, 3.18 (q, 2H), 2.29-2.21 (m, 3H), 1.11-1.13 (m, 3H), 0.97-0.93 (m, 3H)

Example 7 Preparation of 2-Epihydroxy-3-deoxyasiatic Acid (10)

Methyl 2-epihydroxy-3-deoxyasiatate (9) (67 mg, 0.14 mmol) and lithium iodide (77 mg) were dissolved in anhydrous pyridine (5 ml) and refluxed for 8 hours. After completion of the reaction, the solvent was removed by evaporation under reduced pressure, extracted with ethyl acetate, neutralized with 1N aqueous hydrochloric acid solution, washed, dried and separated and purified by column chromatography (hexane: ethyl acetate = 2: 1) to give 38.9 mg ( 58%) of 2-epihydroxy-3-deoxyamic acid (10) was obtained.

IR (neat): 3850, 3363, 1693, 1033 cm ^-1

Mass (EI): m / e 472 (M +)

¹ H-NMR (CD ₃ OD): 5.28 (m, 1H), 3.48, 3.28 (q, 2H), 2.29-2.21 (m, 3H), 1.11-1.14 (m, 3H), 0.97-0.93 (m, 3H)

Example 8 Preparation of Ethoxymethyl-2-Epihydroxy-3-deoxyasiatate (11)

2-Epihydroxy-3-deoxyamic acid (10) (0.28g) was dissolved in anhydrous tetrahydrofuran (10ml), and N, N-diisopropylethylamine (0.32ml) was added at 0 ° C and 10 After stirring for 10 minutes, chloromethylethyl ether (0.17 ml) was added thereto, followed by stirring for 10 minutes. After completion of the reaction, methanol was added, the solvent was removed, and the residue was separated and purified by column chromatography (hexane: ethyl acetate = 3: 1) to give 0.25 g (92%) of ethoxymethyl-2-epihydroxy-3-deoxyasia. Tate (11) was obtained.

IR (neat): 3390, 1692, 1031 cm ^-1

Mass (EI): m / e 530 (M ⁺ )

¹ H-NMR (CD ₃ OD): 5.27 (m, 1H), 4.67 (d, 2H), 3.49 (d, 2H), 3.66-3.56 (m, 6H), 1.12-0.99 (m, 3H)

Example 9 Preparation of Ethoxymethyl-2-oxo-3-deoxyasiatate (12)

Ethoxymethyl-2-epihydroxy-3-deoxyasiatate (11) (260 mg, 0.48 mmol) and chromic acid (140 mg, 0.14 mmol) are dissolved in 40 ml of anhydrous pyridine and stirred at room temperature for 12 hours under a stream of nitrogen. It was. After completion of the reaction, a small amount of saturated sodium bicarbonate was added and the solvent was removed. The residue was extracted with ethyl acetate, washed, dried and separated and purified by column chromatography (hexane: ethyl acetate = 4: 1) to give 118 mg (45.9%) of ethoxymethyl-2-oxo-3-deoxyasiatate (12). )

IR (neat): 2925, 1694, 1285 cm ^-1

Mass (EI): m / e 528 (M ⁺ )

¹ H-NMR (CD ₃ OD): 5.47-5.27 (m, 1 H), 3.06, 2.67 (q, 2 H), 2.18 (d, 1 H), 2.03 (d, 1 H), 1.06, 1.13, 0.90. 0.79 (each s 3H)

Example 10 Preparation of 2-oxo-3-deoxyamic acid (13)

Tetrahydrofuran (10 ml) and 1N hydrochloric acid solution (1 ml) were added to Compound 12 (460 mg, 0.87 mmol), and the mixture was stirred at room temperature for 5 hours. The solvent was distilled off under reduced pressure to completely remove the residue, and the obtained residue was purified by column chromatography (hexane: ethyl acetate = 3: 2) to give 402 mg (yield: 95%) of 2-oxo-3-deoxyamic acid (13). Was obtained as a white solid.

IR (neat): 2925, 1694, 1285 cm ^-1

Mass (EI): m / e 470 (M ⁺ )

¹ H-NMR (CD ₃ OD): 5.47-5.27 (m, 1 H), 3.06, 2.67 (q, 2 H), 2.18 (d, 1 H), 2.03 (d, 1 H), 1.06, 1.13, 0.90. 0.79 (each s 3H)

Example 11 Preparation of 2,3,13-O-triacetylasiatic Acid (14)

2.11 g of Asian acid (3) and 53 mg of dimethylaminopyridine were dissolved in 15 ml of pyridine, and 7.5 ml of acetic anhydride was added to reflux. After the reaction solvent was removed under reduced pressure, the residue was diluted with 50 ml of ethyl acetate and washed with dilute hydrochloric acid solution. After drying the solvent, filtration and evaporation under reduced pressure, the residue was separated by column chromatography (dichloromethane: methanol = 30: 1), and 1.0 g (45%) of 2,3,13-O-triacetylasiatic acid (14 )

Mass (EI): m / e 614 (M ⁺ )

¹ H-NMR (CDCl ₃ ): δ 1.92, 1.96, 2.02 (each s, 3H), 2.12 (d, 1H, J = 10.7 Hz), 3.65 (d, 1H, J = 11.7 Hz), 5.01 (d, 1H, J = 10.2Hz), 5.05-5.12 (m, 1H), 5.17 (t, 1H), 10.72 (br, 1H)

Example 12 Preparation of Tetrahydropyranylasiatic Acid (15-1)

2,3,13-O-triacetylasiatic acid (14) (1 g), dihydropyran (0.6 ml) and pyridinium parasulfonate (200 mg) were dissolved in dichloromethane and stirred at room temperature for 2 hours. Thereafter, the mixture was diluted with 100 ml of dichloromethane, washed with saturated sodium bicarbonate water, dried, and the solvent was evaporated under reduced pressure. The resulting residue was dissolved in methanol (15 ml) and tetrahydrofuran (5 ml), and potassium carbonate (400 mg) was added thereto, followed by stirring at room temperature for 6 hours. The solvent was then evaporated under reduced pressure to remove the residue, which was then dissolved in ethyl acetate (100 ml), washed with water, dried and separated by column chromatography (dichloromethane: methanol = 30: 1) to give 0.5 g (85%) of tetrahydropyranylasia. Triacid (15-1) was obtained.

IR (KBr): 3440, 1740 cm ^-1

Mass (EI): m / e 572 (M ⁺ )

¹ H-NMR (CDCl ₃ ): 2.27 (d, 1H, J = 11.5 Hz), 3.46-3.64 (m, 1H), 4.83-4.92 (m, 3H), 5.26 (br, 1H)

Example 13 Preparation of Tetrahydrofuranyl Asian Acid (15-2)

The same method was used in Example 12 except that dihydrofuran was used instead of dihydropyran.

IR (KBr): 3445, 1738 cm ^-1

Mass (EI): m / e 558 (M ⁺ )

¹ H-NMR (CDCl ₃ ): 2.25 (d, 1H, J = 11.5 Hz), 3.44-3.64 (m, 1H), 4.80-4.92 (m, 3H), 5.26 (br, 1H)

Example 14 Preparation of α-Ethoxy-Ethyl Asian Acid (15-3)

In Example 12, the same method was used except that ethyl vinyl ether was used instead of dihydropyran.

IR (KBr): 3435, 1740 cm ^-1

Mass (EI): m / e 560 (M ⁺ )

¹ H-NMR (CDCl ₃ ): 2.30 (d, 1H, J = 11.5 Hz), 3.56-3.64 (m, 1H), 4.83-4.90 (m, 3H), 5.25 (br, 1H)

Example 15 Preparation of 3,23-O-Isopropylidene Asiatic Acid (16)

Asian acid (10 g) and p-toluenesulfonic acid (200 mg) were dissolved in anhydrous DMF (100 ml), 2, 2-dimethoxypropane (5 ml) was added and stirred at room temperature for 14 hours. The reaction mixture was neutralized and concentrated under reduced pressure to remove the solvent. Extraction, washing and drying were followed by column chromatography (dichloromethane: methanol = 30: 1) to obtain 8.04 g (75%) of 3,23-O-isopropylidene asiatic acid (16).

IR (neat): 3440, 1698, 1200 cm ^-1

Mass (EI): m / e 528 (M ⁺ )

¹ H-NMR (CDCl ₃ ): δ 0.75, 1.04, 1.06, 1.09, 1.45, 1.46 (each s, 3H), 0.85 (d, 3H, J = 6.4 Hz), 0.95 (d, 3H, J = 6.4 Hz ), 2.18 (d, 1H, J = 11.2 Hz), 3.32 (d, 1H, J = 9.6 Hz), 3.46, 3.51 (ABq, 2H, J = 10.8 Hz), 3.78 (m, 1H), 5.24 (brt , 1H)

Example 16 Preparation of Ethoxymethyl-3,23-O-isopropylidene asiatate (17)

3,23-O-isopropylidene asiatic acid (16) (100.0 mg, 0.19 mmol) was dissolved in anhydrous dichloromethane, and N, N-diisopropylethylamine (49.6 μl, 0.28 mmol) was added dropwise and 10 at room temperature After stirring for minutes, ethoxymethyl fluoride (21.1 μl, 0.23 mmol) was added dropwise at 0 ° C. and stirred for 20 minutes. The reaction mixture was diluted with dichloromethane, washed with saturated aqueous sodium bicarbonate and brine and dried. The filtrate was concentrated under reduced pressure, and the obtained residue was separated and purified through column chromatography (hexane: ethyl acetate = 3: 1), to obtain 91.3 mg (82.3%) of ethoxymethyl-3,23-O-isopropylidene asiatate (17). Obtained.

IR (KBr): 3440, 2921, 755 cm ^-1

Mass (EI): m / e 586 (M +)

¹ H-NMR (CDCl ₃ ): δ 5.246 (t, 1H, J = 3.2 Hz), 5.210 (s, 2H), 3.807-3.724 (m, 1H), 3.641 (q, 2H, J = 7.1 Hz), 3.491, 3.441 (ABq, 2H, J = 10.5 Hz), 3.296 (d, 1H, J = 9.8 Hz), 1.434, 1.424, 1.082, 1.051, 1.015, 0.744 (each s, 3H) , 1.198 (t, 3H, J = 7.1 Hz), 0.928 (d, 3H, J = 5.3 Hz), 0.840 (d, 3H, J = 6.3 Hz)

Example 17 Preparation of Ethoxymethyl-2-Xantyl-3,23-O-isopropylidene asiatate (18)

Ethoxymethyl-3,23-O-isopropylidene asiatate (17) (146.0 mg, 0.25 mmol), sodium hydride (60% mineral oil suspension, 29.9 mg, 0.75 mmol), imidazole (8.5 mg, 0.12 mmol) was dissolved in anhydrous tetrahydrofuran, stirred at room temperature for 30 minutes, and carbon disulfide (0.6 ml) was added dropwise and heated to reflux for 2 hours. Methyl iodide (0.3 ml, excess) was added dropwise and heated to reflux for 2 hours. The reaction mixture was quenched with a small amount of water, the solvent was concentrated under reduced pressure, the residue was extracted, washed, and dried with ethyl acetate. The residue was separated and purified by column chromatography (hexane: ethyl acetate = 10: 1) to obtain 135.6 mg ( 80.5%) of ethoxymethyl-2-xanthyl-3,23-O-isopropylidene asiatate (18) was obtained.

IR (KBr): 1724, 1232, 1056 cm ^-1

Mass (EI): m / e 676 (M ⁺ )

¹ H-NMR (CDCl ₃ ) δ 5.745 (m, 1H), 5.231 (t, 1H), 5.209 (s, 2H), 3.779 (d, 1H, J = 10.0 Hz), 3.638 (q, 2 H, J = 6.8 Hz), 3.543, 3.489 (ABq, 2 H, J = 7.2 Hz), 2.491 (s, 3 H), 1.428, 1.389, 1.125, 1.087, 1.079, 0.750 (each s, 3 H) , 1.199 (t, 3H, J = 6.9 Hz), 0.923 (d, 3H, J = 5.6 Hz), 0.822 (d, 3H, J = 6.4 Hz)

Example 18 Preparation of Ethoxymethyl-2-deoxy-3,23-O-isopropylidene asiatate (19)

Ethoxymethyl-2-xanthyl-3,23-O-isopropylidene asiatate (18) (110.0 mg, 0.16 mmol) and AIBN (5.3 mg, 0.032 mmol) were dissolved in anhydrous benzene and then tributyltin hydride ( 131.3 μl, 0.49 mmol) was added dropwise and heated to reflux for 1.5 hours. The solvent was removed by concentration under reduced pressure, and the obtained residue was separated and purified through column chromatography (hexane: ethyl acetate = 10: 1), to obtain 71.2 mg (76.7%) of a white solid.

IR (KBr): 2914, 1723, 1201 cm ^-1

Mass (EI): m / e 570 (M ⁺ )

¹ H-NMR (CDCl ₃ ) δ 5.242 (t, 1 H), 5.212 (s, 2 H), 3.642 (q, 2 H, J = 7.1 Hz), 3.517, 3.421 (q, 2 H, J = 10.5 Hz), 3.474 (t, 1H), 1.430, 1.398, 1.083, 1.033, 0.947, 0.748 (each s, 3H), 1.198 (t, 3H, J = 7.1 Hz), 0.927 (d, 3H, J = 6.1 Hz), 0.846 (d, 3 H, J = 6.6 Hz)

Example 19 Preparation of 2-Deoxy-Asiatic Acid (20)

Ethoxymethyl-2-deoxy-3,23-O-isopropylidene asiatate (19) (65.0 mg, 0.11 mmol) was dissolved in methanol: dichloromethane (2: 1), and a catalytic amount of 6N hydrochloric acid was added dropwise. And stirred at room temperature for 4 hours. The solvent was removed by concentration under reduced pressure. The obtained residue was extracted, washed with ethyl acetate and dried, and the residue was purified by column chromatography (hexane: ethyl acetate = 1: 2) to give 54.3 mg (100%) of 2-deoxy-. Asiatic acid (20) was obtained.

IR (KBr): 3436, 1693 cm ^-1

MS (EI): 472 (M ⁺ )

¹ H NMR (CDCl ₃ + pyridine-d ₅ ): δ5.21 (1H, bt, J = 2.8 Hz, 3.6 Hz),

3.60 (1H, t, J = 7.2 Hz, 8.2 Hz), 3.36, 3.70 (2H, dd, J = 10.0 Hz), 2.21 (1H, d, J = 1.2 Hz)

Formulation Preparation Example 1 Tablet

5.0 mg of active ingredient

Lactose BP 150.0 mg

Starch BP 30.0 mg

Pregelatinized Corn Starch BP 15.0 mg

1.0 mg magnesium stearate

The active ingredient is sieved and mixed with lactose, starch and pregelatinized corn starch, then a suitable volume of purified water is added and granulated into a powder. The granules were dried and then mixed with magnesium stearate and compressed to obtain tablets.

Formulation Preparation Example 2 Capsule

5.0 mg of active ingredient

Starch 1500 100.0 mg

1.0 mg magnesium stearate

The active ingredient was filled, mixed with excipients and filled into gelatin capsules to obtain capsules.

Formulation Preparation Example 3 Injection

Active ingredient 1000 ㎍ / ml

Dilute hydrochloric acid BP up to pH 3.5

Injectable sodium chloride BP up to 1 ml

The active ingredient was dissolved in an appropriate volume of sodium chloride BP for injection, and the pH of the resulting solution was adjusted to pH 3.5 with diluted hydrochloric acid BP, then the volume was adjusted with sodium chloride BP for injection and thoroughly mixed. The solution was filled into a 5 ml Type 1 ampoule of clear glass, dissolved in glass and enclosed under an upper grid of air, then sterilized by autoclaving at 120 ° C. for at least 15 minutes to obtain an injection.

Experimental Example 1. Anti-dementia effect test of derivatives on scopolamine-induced dementia.

The experimental animals were 25-30 g male ICR mice, and dementia was induced by subcutaneous injection of 1 mg / kg of scopolamine 30 minutes before the test.

1 hour after the intraperitoneal injection of the compound of the present invention and subcutaneous injection of 1 mg / kg of scopolamine 30 minutes after measuring the passive learning ability, anti-dementia to prevent the dementia caused by scopolamine of the compound of the present invention The effect was investigated. At this time, the scopolamine non-administered group and the scopolamine-administered group were used as a control group, and aspartic acid and velnacrine-administered group, a conventional treatment for dementia, were used as comparative examples.

The passive avoidance test used in the experiment is as follows.

The avoidance reaction box (40 x 20 x 20 cm) with 3 mm thick gratings at the bottom is divided into a bright room and a dark room. When the mouse in the bright room enters the dark room, the grid ( The grid was trained to give 0.3 전기 of electrical stimulation, and the same test was performed after 24 hours to measure the time (dwelling time) of the mouse staying in a bright room as an index to remember the previous day's training. The retention time at this time was positive for 180 seconds or more.

The result was 100% for 180 seconds of normal dementia-free mice staying in a bright room, and 34.5 seconds for dementia-induced mice staying in a bright room with 0% scopolamine. Anti-dementia effect.

The experimental results are shown in Table 1.

Anti-Dementia Effects of Asian Acid Derivatives on Scopolamine-induced Dementia compound Concentration (mg / kg) Stay time (s) Antidementia effect t (%) Control 180.0 ± 15.0 100.0 Reference 34.5 ± 7.1 0.0 Velnakrin 1.0 92.7 ± 19.2 40.0 Asiatic acid 0.1 23.1 ± 11.2 -7.8 1.0 55.5 ± 21.9 14.4 Madecassan 0.1 25.2 ± 5.3 -6.4 1.0 32.5 ± 8.7 -1.4 AS-1 0.1 78.4 ± 15.3 30.2 1.0 51.1 ± 13.2 11.4 AS-2-9 1.0 49.8 ± 15.2 10.0 79.3 ± 20.5 AS-2-9-006 1.0 64.3 ± 10.5 20.5 10.0 134.2 ± 18.5 68.5 AS-9 1.0 50.0 ± 15.5 10.0 78.9 ± 12.2 AS-9-006 1.0 80.5 ± 19.0 16.6 10.0 145.0 ± 33.4 76.2 However, AS-1: Methyl asiatate (4), AS-2-9: 2-oxo-3-deoxyamic acid (13), AS-2-9-006: ethoxymethyl-2-oxo-3 -Deoxy asiatate (12), AS-9: 2-epihydroxy-3-deoxy asiatic acid (10), AS-9-006: ethoxymethyl-3-deoxy asiatate (11).

As shown in Table 1, 10 mg / kg ethoxymethyl-2-oxo-3-deoxyasiatate (68.5%), and 10 mg / kg ethoxymethyl-3-deoxyasiatate (76.2%) It has a better antidementia effect than Belnakrine (40%).

Experimental Example 2. Aβ-amyloid-induced neurotoxicity protective effect test.

The compound of the present invention (1 μM) was added to the brain neuron B103 cell, and then left at 37 ° C. for 1 hour, and then toxic inducer Aβ _23-35 was added and left for 24 hours. Thereafter, the number of surviving neurons was quantified by measuring the absorbance at OD 570-630 nm using the MTT assay. Cerebral nerve protection was compared with Aβ _23-35 when the absorbance was 0 and the control was 100.

The experimental results are shown in Table 2.

Aβ-amyloid-induced neurotoxic protective effect compound Protective effect (%) Control 100 Asiaticoside 24 Asiatic acid 97 Madecassan 54 AS-1 58 AS-2 50 AS-6 87 AS-19 65 SM-2 93 SM-8 73 SM-29 70 However, AS-1: Methyl asiatate (4), AS-2: 2-oxoasiatic acid, AS-6: 2-deoxyasianate (20), AS-19: 3,23-O-isopropylidene -Asiatic acid (16), SM-2: tetrahydropyranyl asiatic acid (15-1), SM-8; Tetrahydrofuranyl asian acid (15-2). SM-29: ethyloxy-1'-ethyl asian acid (15-3),

As shown in Table 2, 1 μM of asiatic acid (97%), 1 μM of 2-deoxyasiatic acid (87%), and 1 μM of tetrahydropyranylasiatic acid (93%) are conventional glycosides of Asiatico It showed better neuronal protection than Said (24%).

As can be seen in the experimental example, the asiatic acid derivatives according to the present invention exhibited an excellent effect on neuroprotective neurons, and was excellent in improving dementia and cognitive impairment.

Claims (6)

An agent for treating dementia and cognitive impairment comprising an asiatic acid derivative represented by Formula 1 as an active ingredient, a pharmaceutically acceptable salt or ester thereof; In the formula, R ₁ represents hydrogen or a hydroxy group; R ₂ represents hydrogen, a hydroxy group; R ₁ and R ₂ together may form an oxo group; R ₃ represents hydrogen, a hydroxy group; R ₄ represents hydrogen or a hydroxy group; R ₂ and R ₄ together may form an epoxy group; R ₅ represents a hydroxymethyl group, tert-butyldimethylsilyloxymethyl group, carboxyl group, carboxyl ester residue, carboxyl amide residue or aldehyde group in which a methyl group, a hydroxy group may be protected by an acetyl or benzoyl group; R ₄ may form —OCR ₆ R ₇ OCH ₂ — with R ₅ (where R ₆ is hydrogen, lower alkyl or phenyl having 1 to 4 carbon atoms, and R ₇ is hydrogen, lower of 1 to 4 carbon atoms); Alkyl or phenyl, and R ₆ and R ₇ together may form — (CH ₂ ) ₅ —; R ₈ represents hydrogen or a methyl group; R ₉ is —CH ₂ COOR or —COOR, wherein R is hydrogen, lower alkyl of 1 to 4 carbon atoms, 2-tetrahydropyranyl, 2-tetrahydrofuranyl, CH (OR ₁₁ ) R ₁₀ (R ₁₀ Is a lower alkyl group having 1 to 4 carbon atoms, R ₁₁ is a lower alkyl group having 1 to 4 carbon atoms, octyl, benzyl, methoxymethyl or methoxyethyl group), or a glucosyl or rhamnosyl group whose hydroxy group may be protected by acetyl or benzoyl. Hydroxymethyl, methanesulfonyloxymethyl or cyanomethyl group which may be protected by acetyl or benzoyl. The agent for treating dementia and cognitive impairment according to claim 1, wherein the active ingredient is ethoxymethyl-2-oxo-3-deoxyasiatate. The agent for treating dementia and cognitive impairment according to claim 1, wherein the active ingredient is ethoxymethyl-3-deoxyasiatate. The agent for treating dementia and cognitive impairment according to claim 1, wherein the active ingredient is asian acid. The agent for treating dementia and cognitive impairment according to claim 1, wherein the active ingredient is 2-deoxyasian acid. The agent for treating dementia and cognitive impairment according to claim 1, wherein the active ingredient is tetrahydropyranylasiatic acid.