Spirooxindole alkaloids in polygonum cuspidatum and methods of making and using the same

Abstract

The present application belongs to the technical field of medicine, and relates to four spirooxindole alkaloids extracted and separated from a plant of the genus Persicaria in the Polygonaceae family, a Persicaria tinctoria, and a preparation method and use thereof. The compound 1a / 1b is a pair of enantiomers, has a 6 / 5 / 5 / 6 four-ring system and a 3-phenyl-4,5-dihydro-3H-spiro[furan-2,3'-indoline] skeleton. The compound 2 and the compound 3 have a 6 / 5 / 6 / 5 / 6 five-ring system skeleton and a 3'-methyl-2',3',4',9'-tetrahydrospiro[indole-3,1'-pyrido[3,4-b]indole] skeleton. The present application also relates to a separation and biomimetic synthesis preparation method of the compounds, and use of the compounds in preparation of medicines for treating neurodegenerative diseases. The preparation method of the present application requires low-cost and easily-obtained reagents, the obtained compounds have good neuroprotective effects, have the characteristics of simple operation and good reproducibility, are conducive to industrial production, and have high potential value and wide application prospect in the fields of medicine, medicinal chemistry and natural product synthesis.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of medicine, and particularly relates to a new spirooxindole alkaloid in a plant of Persicaria tinctoria (Aiton) Spach, a separation and biomimetic synthesis preparation method of the spirooxindole alkaloid, and application of the compound in nerve cell protection. BACKGROUND

[0002] Persicaria tinctoria (Aiton) Spach belongs to the plant of the family Polygonaceae and the genus Polygonum, is an annual herb, and is cultivated or in a semi-wild state in various regions of China. The leaf of Persicaria tinctoria has a long history of use in China, and the dried leaf is used as a medicinal material of Loniaoqingye. Persicaria tinctoria is cold in nature and bitter in taste, and has the effects of clearing heat and resolving toxins, cooling blood and removing spots.

[0003] According to the latest statistical data of the World Health Organization, the global high-risk population of neurodegenerative diseases has climbed to a huge number of 200 million, and the number of newly diagnosed cases per year is also showing an increasing trend, between 1 million and 2 million. Therefore, it is necessary to develop therapeutic drugs for neurodegenerative diseases. Oxidative stress is closely related to many neurodegenerative diseases, and oxidative stress caused by glutamate (Glu) is an important inducement of neurodegenerative diseases. SUMMARY

[0004] The purpose of the present application is to provide a new spirooxindole alkaloid in a plant of Persicaria tinctoria (Aiton) Spach, a separation and biomimetic synthesis preparation method of the spirooxindole alkaloid, and application of the compound in nerve cell protection.

[0005] The present application relates to a new spirooxindole alkaloid isolated from the plant of Persicaria tinctoria (Aiton) Spach, and the structure is as shown in the figure:

[0006]

[0007] The separation and preparation technical scheme of the new spirooxindole alkaloid in Persicaria tinctoria (Aiton) Spach of the present application comprises the following steps:

[0008] The dried leaves of Persicaria tinctoria are extracted with ethanol, the extract is concentrated to obtain an extract, the extract is extracted with dichloromethane, and the obtained components are subjected to silica gel column chromatography, and isocratic gradient elution is performed with a dichloromethane-methanol system 100:1-1:1, and 4 flow portions A-D are collected.

[0009] Gradient elution is performed on the flow portions A and B with an ethanol-water system 30:70-90:10 using HP20 column chromatography, and two components A1 and A2 are obtained; B1 and B2 are obtained.

[0010] The fractions A1 and B2 were separated by ODS column chromatography using a gradient elution with ethanol-water system 30:70-90:10, to give three fractions A1-1-A1-3 and B2-1-B2-3, respectively.

[0011] The fraction A1-3 was separated by silica gel column chromatography using dichloromethane-methanol system 100:1-30:1 to give four sub-fractions a1-a4 based on TLC analysis. The fraction B2-3 was separated by silica gel column chromatography using dichloromethane-methanol system 50:1-20:1 to give four sub-fractions b1-b4 based on TLC analysis.

[0012] Compound 1 was obtained by preparative reverse-phase high performance liquid chromatography using methanol-water mobile phase to separate a4. Compounds 2 and 3 were obtained by preparative reverse-phase high performance liquid chromatography using methanol-water mobile phase to separate b4.

[0013] Compound 1 was separated by Chiralpak AD-H chiral column using n-hexane-isopropanol mobile phase to give (+)-1 and (-)-1.

[0014] In the step, the polygonum is the dried leaf of Polygonum hydropiperper.

[0015] In the step, the dried leaf of Polygonum hydropiperper is refluxed with 70-80% industrial ethanol for 3-4 times, each time for 2-3 hours.

[0016] In the step, a4 is separated by preparative reverse-phase high performance liquid chromatography using 50:50 methanol-water mobile phase; b4 is separated by preparative reverse-phase high performance liquid chromatography using 60:40 methanol-water mobile phase.

[0017] In the step, Compound 1 is separated by Chiralpak AD-H chiral column using 5:1 n-hexane-isopropanol mobile phase.

[0018] The obtained compounds are subjected to systematic structural identification, and the results are as follows:

[0019] The structures of Compounds 1-3 are identified by high resolution mass spectrometry, one-dimensional NMR, two-dimensional NMR, calculated ECD and X single crystal diffraction method, and the corresponding spectra are shown in Figures 1-5

[0020] Compound 1: light yellow needle-like crystal. (+)-(1): (-)-(1): HRESIMS m / z 296.0914 [M+Na] + (calcd for C 17 H 14 ​NO4, calcd for 296.0917), the molecular formula was determined as C 17 H 13 NO4, by analyzing its 1 H NMR, 13 C NMR, HMQC spectrum, HMBC spectrum, X-ray single crystal diffraction, the structure of compound 1 was determined to be a new compound. After chiral separation, the absolute configuration was determined to be (+)-(3S, 7'R)-1 and (-)-(3R, 7'S)-1 by calculating ECD.

[0021] Compound 2: yellow solid. HRESIMS m / z 348.1345 [M+H] + (calcd for C 20 H 18 N3O3, 348.1343). The molecular formula was determined as C 20 H 17 N3O3, by analyzing its 1 HNMR, 13 C NMR, HMQC spectrum, HMBC spectrum, calculating ECD, the structure of compound 2 was determined to be a new compound, and the absolute configuration was determined to be 3S, 9'R.

[0022] Compound 3: yellow solid. HRESIMS m / z 348.1351 [M+H] + (calcd for C 20 H 18 N3O3, 348.1343). The molecular formula was determined as C 20 H 17 N3O3, by analyzing its 1 HNMR, 13 C NMR, HMQC spectrum, HMBC spectrum, calculating ECD, the structure of compound 2 was determined to be a new compound, and the absolute configuration was determined to be 3R, 9'R.

[0023] Table 1: the physicochemical properties of compounds 1-3 1 H (600MHz) and 13 C (150MHz) data (DMSO-d6)

[0024]

[0025]

[0026] The biomimetic synthesis preparation method of the new spirooxindole alkaloid compound 1 in Polygonum tinctorium Lour. of the application comprises the following steps:

[0027]

[0028] In a sealed tube with a magnet, 3-hydroxyindolinone and trans-p-coumaric acid methyl ester, solvent and catalyst were added respectively, after sealing, inert gas was filled, and the reaction was stirred at reflux temperature for 16-24 h, and then the solvent was removed under reduced pressure to obtain the crude product; the crude product was purified by column chromatography to obtain spirooxindole alkaloids (±)-1 and 7'-epi-(±)-1; and then chiral resolution was performed to obtain enantiomers (+)-1 and (-)-1, 7'-epi-(+)-1 and 7'-epi-(-)-1, respectively.

[0029] In the step, the solvent is p-xylene, and the catalyst is ruthenium dodecacarbonyl, DPPP and potassium tert-butoxide.

[0030] In the step, the column chromatography of the crude product is performed with 3:1-2:1 petroleum ether-ethyl acetate.

[0031] The biomimetic synthesis preparation method of the new spirooxindole alkaloid compounds 2 and 3 in Polygonum tinctorium Lour. of the present application comprises the following steps:

[0032]

[0033] In a sealed tube with a magnet, D-tryptophan methyl ester hydrochloride and indigo were added respectively, dissolved in anhydrous methanol, TFA was added, stirred for 10 min, and then moved to 90℃ for reaction, and then the solvent was removed under reduced pressure to obtain the crude product; the crude product was purified by column chromatography to obtain spirooxindole alkaloids 2 and 3.

[0034] In the step, the reflux time is 0.5-1 h.

[0035] In the step, the column chromatography of the crude product is performed with 100:0-80:1 dichloromethane-methanol.

[0036] The present application also provides a pharmaceutical composition comprising the new spirooxindole alkaloid or a pharmaceutically acceptable salt thereof and a pharmaceutically acceptable carrier or excipient.

[0037] The pharmaceutical composition is a clinically acceptable dosage form.

[0038] Preferably, the dosage form is an injection, a tablet or a capsule.

[0039] The present application also provides a Polygonum tinctorium Lour. extract comprising the new spirooxindole alkaloid.

[0040] The present application also provides the use of the new spirooxindole alkaloid or the pharmaceutical composition comprising the compound in the preparation of a nerve cell protective drug.

[0041] The present invention also provides use of the novel spirooxindole alkaloid or a pharmaceutical composition comprising the compound in the preparation of drugs for preventing and / or treating neurodegenerative diseases.

[0042] The neuroprotective activity of the novel spiro-oxindole alkaloids described in this invention was investigated. The Glu injury model is a commonly used model for studying neuronal cell death caused by oxidative stress. In a glutamate-Glu-induced neurotoxicity model in the mouse hippocampal neuronal cell line HT22, compounds 1-3 demonstrated significant in vitro neuroprotective effects. Therefore, the novel spiro-oxindole alkaloids described in this invention have the potential for further development as drugs for the prevention and treatment of neurodegenerative diseases.

[0043] The advantages of the present invention are that the compounds are all new compounds with novel structures and strong nerve cell protective activity, and are worthy of further development. Description of the drawings:

[0044] Figure 1 HRESIMS of compound 1, 1 H. 13 C-NMR, DEPT, and HMBC spectra;

[0045] Figure 2 HRESIMS of compound 2, 1 H. 13 C-NMR, DEPT, and HMBC spectra;

[0046] Figure 3 HRESIMS of compound 3, 1 H. 13 C-NMR, DEPT, and HMBC spectra;

[0047] Figure 4 ECD patterns of compounds 1-3;

[0048] Figure 5 X-ray single crystal data of compounds 1 and 3. Specific implementation method:

[0049] The following examples are provided to facilitate a better understanding of the present invention for those skilled in the art, but are not intended to limit the present invention in any way. Anhydrous toluene was prepared by adding sodium strips and distilling under reflux in the presence of nitrogen. Anhydrous methanol was purchased using a diaphragm bottle filled with molecular sieves. All chemical reactions involved were analyzed by TLC using GF-254 thin-layer silica gel plates. Extraction and separation of the reaction solutions were performed by column chromatography using 200-300 mesh silica gel as the filler. 1 H NMR and 13CNMR was tested by using deuterated dimethyl sulfoxide as solvent by Bruker Avance-III 600.

[0050] Example 1:

[0051] The new spirooxindole alkaloids were isolated as follows:

[0052] The dried leaves of Polygonum tinctorium were extracted with ethanol, and the extract was concentrated to give a dry extract. The dry extract was extracted with dichloromethane, and the obtained components were separated by silica gel column chromatography, and eluted with dichloromethane-methanol system 100:1-1:1 by isocratic gradient elution. Four fractions A-D were collected.

[0053] Fractions A and B were eluted by gradient elution with ethanol-water system 30:70-90:10 by HP20 column chromatography, and two components A1 and A2; B1 and B2 were obtained.

[0054] Components A1 and B2 were eluted by gradient elution with ethanol-water system 30:70-90:10 by ODS column chromatography, and three components A1-1-A1-3 and B2-1-B2-3 were obtained.

[0055] Component A1-3 was eluted by silica gel column chromatography with dichloromethane-methanol system 100:1-30:1 based on TLC analysis, and four sub-components a1-a4 were obtained. Component B2-3 was eluted by silica gel column chromatography with dichloromethane-methanol system 50:1-20:1 based on TLC analysis, and four sub-components b1-b4 were obtained.

[0056] Compound 1 was obtained by separating a4 on preparative reverse-phase high performance liquid chromatography using methanol-water mobile phase (50:50, v / v). Compounds 2 and 3 were obtained by separating b4 on preparative reverse-phase high performance liquid chromatography using methanol-water mobile phase (60:40, v / v).

[0057] Compound 1 was separated by Chiralpak AD-H chiral chromatographic column using n-hexane-isopropanol mobile phase (5:1, v / v) to obtain 1a and 1b.

[0058] Example 2:

[0059] The synthesis of new spirooxindole alkaloid compound 1 was prepared as follows:

[0060] Into a dry sealed pressure tube with magnetic stirring, 3-hydroxyindolin-2-one (45 mg, 0.3 mmol), trans-p-methylcoumaric acid (107 mg, 0.6 mmol), triruthenium dodecacarbonyl Ru3(CO) 12(3.8 mg, 0.006 mmol), 1,3-bis(diphenylphosphino)propane DPPP (4.2 mg, 0.018 mmol), potassium tert-butoxide t-BuOK (3.3 mg, 0.03 mmol) and toluene (15 mL). The flask was sealed with a rubber septum and protected with nitrogen. The rubber septum was then replaced with a screw cap under a nitrogen purge. The mixture was heated at 140 °C (oil bath temperature) for 20 h. After monitoring the reaction completion by TLC, the reaction was concentrated and purified by column chromatography (Si02; petroleum ether: ethyl acetate = 3: 1-2: 1) to give the crude product as a yellowish solid (38.4 mg, 0.13 mmol, 42%). The crude product was separated on a preparative HPLC (acetonitrile: water = 30:70, v / v, 2.5 mL / min, 210 nm) to give compound 1 (yield 10%) and its epimer 7'-epi-(±)-1 (yield 30%). Compound 1 was resolved on a Chiralpak AD-H chiral column using n-hexane-isopropanol mobile phase (5:1, v / v) with an enantiomeric ratio of 1:1. 1 H NMR spectroscopy (d.r = 3:1). The crude product was separated on a preparative HPLC (acetonitrile: water = 30:70, v / v, 2.5 mL / min, 210 nm) to give compound 1 (yield 10%) and its epimer 7'-epi-(±)-1 (yield 30%). Compound 1 was resolved on a Chiralpak AD-H chiral column using n-hexane-isopropanol mobile phase (5:1, v / v) with an enantiomeric ratio of 1:1.

[0061]

[0062] Compound (±)-1: TLC (Si02): Rf = 0.42 (petroleum ether: ethyl acetate = 1:1). f = 0.42 (petroleum ether: ethyl acetate = 1:1).

[0063] 1 H NMR (600 MHz, DMSO-d6) δ 10.29 (s, 1H), 9.41 (s, 1H), 7.69 (dd, J = 7.6, 1.2 Hz, 1H), 7.33 (td, J = 7.6, 1.2 Hz, 1H), 7.13 (td, J = 7.6, 1.0 Hz, 1H), 6.73 (d, J = 8.6 Hz, 2H), 6.72 (overlap, 1H), 6.55 (d, J = 8.6 Hz, 2H), 4.24 (dd, J = 13.4, 8.2 Hz, 1H), 3.49 (dd, J = 16.9, 13.4 Hz, 1H), 2.86 (dd, J = 16.9, 8.2 Hz, 1H).

[0064] 13 C NMR (150 MHz, DMSO-d6) δ 32.1, 48.4, 86.3, 110.2, 115.1, 122.6, 122.9, 125.1, 125.2, 128.7, 131.2, 142.7, 157.0, 174.4, 175.3

[0065] HRMS(ESI)Calculated for C 17 H 13 NO4[M+H] + =296.0919,Found 296.0917.

[0066] HPLC(CHIRALPAK IG,n-hexane / IPA(4:1),0.8mL / min,210nm):(+)-1,t R =22.3min,(-)-1,

[0067] t R =26.4min.(+)-1:(-)-1=1:1.

[0068]

[0069] Compound 7′-epi-(±)-1:TLC(SiO2):R f =0.42 (petroleum ether:ethyl acetate=1:1).

[0070] 1 H NMR (600MHz, DMSO-d6) δ10.70(s,1H),9.39(s,1H),7.15(td,J=7.7,1.2Hz,1H),7.01(dd,J=7.7,1.2Hz,1H),6.86(d,J=8.6Hz,2H),6.80(td,J= 7.7,1.0Hz,1H),6.74(d,J=7.7Hz,1H),6.56(d,J=8.6Hz,2H),4.05(t,J=9.1Hz,1H),3.47(dd,J=17.6,9.8Hz,1H),3.21(dd,J=17.6,8.5Hz,1H).

[0071] 13 C NMR (150MHz, DMSO-d6) δ32.7,46.7,86.1,110.3,115.1,121.8,124.4,125.6,125.9,128.7,130.6,142.0,156.7,174.7,175.6

[0072] HRMS(ESI)Calculated for C 17 H 13 NO4[M+H] + =296.0925,Found 296.0917

[0073] HPLC (CHIRALPAK IG, n-hexane / IPA (5:1), 0.8 mL / min, 210 nm): 7'-epi-(-)-1, t R = 11.3 min,

[0074] 7'-epi-(+)-1, t R = 15.5 min. 7'-epi-(-)-1 : 7'-epi-(+)-1 = 1 : 1.

[0075] Example 3:

[0076] The preparation of novel spirooxindole alkaloid compounds 2 and 3 was carried out as follows:

[0077] To a dry sealed pressure tube fitted with magnetic stirring was added tryptamine methyl ester hydrochloride (218 mg, 1 mmol), isatin (123 mg, 0.83 mmol) and trifluoroacetic acid TFA (22.8 mg, 0.2 mmol) in dry methanol ((15 mL) and the sealed tube was sealed with a screw cap and moved to 90 °C for 1 h. The reaction was monitored by TLC and upon completion of the reaction, the solvent was evaporated under reduced pressure. The mixture was dissolved in ethyl acetate (15.0 mL) and the reaction was quenched by the addition of saturated sodium bicarbonate solution (5.0 mL). The mixture was extracted with ethyl acetate (3 x 15.0 mL) and the combined organic phase was washed with saturated aqueous NaCl (2 x 15.0 mL) and then dried over anhydrous MgS04. The solvent was removed to give the crude product. Column chromatography (Si02, dichloromethane:methanol = 100:1) gave compound 2 (yield 11%) and compound 3 (yield 81%) as a light yellow solid.

[0078]

[0079] 2: 1 HNMR (600 MHz, DMSO-d6) δ 10.82 (s, 1H), 10.69 (s, 1H), 7.49 (d, J = 7.8 Hz, 1H), 7.27 (td, J = 7.7, 1.2 Hz, 1H), 7.25 (d, J = 7.6 Hz, 1H), 7.17 (dt, J = 8.0, 0.9 Hz, 1H), 7.05 (ddd, J = 8.2, 7.0, 1.2 Hz, 1H), 6.99 (ddd, J = 7.8, 5.8, 1.1 Hz, 2H), 6.90 (td, J = 7.5, 1.1 Hz, 1H), 4.24 (td, J = 11.0, 4.4 Hz, 1H), 3.20 (dd, J = 15.2, 4.4 Hz, 1H), 2.85 (dd, J = 15.2, 10.9 Hz, 1H), 2.48 (d, J = 11.6 Hz, 2H).

[0080] 13 C NMR (150 MHz, DMSO-d6) δ 24.9, 52.1, 52.7, 62.0, 108.7, 110.5, 111.3, 118.0, 118.8, 121.8, 122.0, 124.8, 126.0, 129.4, 130.5, 132.6, 136.5, 141.8, 172.6, 176.4

[0081] HRMS (ESI) Calcd for C 20 H 17 N3O3[M+H] + = 348.1345, Found 348.1343

[0082]

[0083] 3: 1 H NMR (600 MHz, DMSO-d6) δ 10.49 (s, 1H), 10.48 (s, 1H), 7.49 (dd, J = 7.8, 1.2 Hz, 1H), 7.30 (td, J = 7.7, 1.3 Hz, 1H), 7.18 (dt, J = 8.0, 1.0 Hz, 1H), 7.13 (dd, J = 7.4, 1.3 Hz, 1H), 7.04 (ddd, J = 8.1, 7.0, 1.3 Hz, 1H), 6.99 (ddd, J = 7.8, 6.9, 1.1 Hz, 1H), 6.97 (td, J = 7.4, 1.0 Hz, 0H), 6.95 (d, J = 7.6 Hz, 1H), 4.75 (ddd, J = 11.2, 6.9, 4.2 Hz, 1H), 3.24 (d, J = 6.9 Hz, 1H), 3.11 (dd, J = 15.0, 4.2 Hz, 1H), 2.90 (dd, J = 15.0, 11.2 Hz, 1H).

[0084] 13 C NMR (150 MHz, DMSO-d6) δ 25.0, 51.6, 51.9, 61.1, 109.4, 110.0, 111.3, 117.9, 118.7, 121.5, 121.9, 124.9, 126.3, 129.6, 131.3, 131.3, 136.5, 142.8, 172.9, 178.3

[0085] HRMS (ESI) Calcd for C 20 H 17 N3O3[M+H] += 348.1351, Found 348.1343

[0086] Example 4: Detection of the effect of compounds 1-3 on the viability of HT22 cells

[0087] The CCK-8 method was used for detection. The HT22 cells in the logarithmic growth phase were inoculated in a 96-well plate at 1 x 10 4 cells per well, and cultured for 12 h, then glutamic acid Glu (final concentration 5 mM) and compounds (3.125, 6.25, 12.5, 25, 50 μM) were added, and a control group (Con) and a blank well (corresponding amount of cell culture medium and CCK-8 solution) were set up, with 5 replicate wells per well. After being placed in an incubator for 6 h, 10 μL of CCK-8 solution was added to each well (100 μL of culture medium per well), and the wells were placed in an incubator for 2 h, after which the absorbance value (A) of each well was determined at 450 nm on an enzyme marker instrument. The survival rate of each experimental well was calculated. Survival rate = (A 实验组 -A 空白组 ) / (A 对照组 -A 空白组 ) x 100%, and the experiment was repeated 3 times.

[0088] Table 2 Protective effect of compounds 1-3 on Glu-induced neurotoxicity of HT22 cells (survival rate %)

[0089]

Claims

1. Spirooxindole alkaloids (+)-1 and (−)-1 from Polygonum indigofera, characterized by: It has the structure shown in the following formula: 。 2. The spirooxindole alkaloids (+)-1 and (−)-1 from Polygonum indigofera according to claim 1, characterized in that The indigo plant is the indigo plant of the genus Polygonum in the family Polygonaceae. Persicaria tinctoria (Aiton) Spach].

3. The method for separating and preparing the spirooxindole alkaloids (+)-1 and (−)-1 in Polygonum indigofera according to claim 1 or claim 2, characterized in that: The steps include: Take Polygonum indigo[ Persicaria tinctoria The dried leaves of Aiton Spach were extracted with ethanol at reflux, and the combined extracts were concentrated to obtain an extract. The extract was extracted with dichloromethane, and the resulting fractions were chromatographed on a silica gel column using an isocratic gradient elution system of dichloromethane-methanol (100:1-1:1). A total of four fractions, A-D, were collected. Fractions A and B were subjected to HP20 column chromatography with an ethanol-water system of 0:100-100:0 for gradient elution to obtain two components A1 and A2 respectively. For B1 and B2, components A1 and B2 were subjected to ODS column chromatography with an ethanol-water system of 30:70-90:10 for gradient elution to obtain three components A1-1‒A1-3 and B2-1‒B2-3 respectively. The obtained component A1-3 was subjected to silica gel column chromatography with a dichloromethane-methanol system of 100:1-30:

1. Based on TLC analysis, four subcomponents a1‒a4 were obtained. A4 was separated on preparative reverse-phase HPLC using a methanol-water mobile phase to obtain compound 1, and compound 1 was resolved on an IG chiral column using n-hexane-isopropanol mobile phase to obtain (+)-1 and (−)-1.

4. The method for separating and preparing spirooxindole alkaloids (+)-1 and (−)-1 in Polygonum indigofera according to claim 3, characterized in that: The dried leaves of Polygonum indigofera were extracted with 70-80% ethanol under reflux for 3-4 times, each time for 2-3 h. a4 was separated with a 50:50 methanol-water mobile phase, and compound 1 was resolved with a 5:1 n-hexane-isopropanol mobile phase to obtain (+)-1 and (−)-1.

5. The biomimetic synthesis method for preparing the spirooxindole alkaloids (+)-1 and (−)-1 in Polygonum indigo as claimed in claim 1 or claim 2, characterized in that: The steps include: ； 3-Hydroxyindolinone, methyl trans-p-coumarate, a solvent, and a catalyst were added to a sealed tube equipped with a magnetic rod. The tube was sealed and filled with inert gas. The reaction was stirred at reflux temperature for 16 to 24 hours. The solvent was removed under reduced pressure to obtain a crude product. The crude product was purified by column chromatography to obtain spirooxindole alkaloid compound 1. Chiral resolution was then performed to obtain the enantiomers (+)-1 and (−)-1, respectively.

6. The biomimetic synthesis method for preparing the spirooxindole alkaloids (+)-1 and (−)-1 from Polygonum indigofera according to claim 5, characterized in that: The solvent is p-xylene, the catalyst is ruthenium dodecacarbonyl, 1,3-bis(diphenylphosphino)propane (DPPP) and potassium tert-butoxide, and the crude product is separated by column chromatography using petroleum ether-ethyl acetate in a ratio of 3:1-2:

1.

7. A pharmaceutical composition, characterized in that The spirooxindole alkaloids (+)-1 and (−)-1 or pharmaceutically acceptable salts thereof according to claim 1 or claim 2 are used as active ingredients and mixed with pharmaceutically acceptable excipients to prepare a composition, wherein the composition is a clinically acceptable dosage form, which is an injection, tablet or capsule.

8. Use of the spirooxindole alkaloids (+)-1 and (−)-1 according to claim 1 or claim 2 or their pharmaceutically acceptable salts, or the pharmaceutical composition according to claim 7, in the preparation of a medicament for preventing and / or treating neurodegenerative diseases, characterized in that: The drug has a neuroprotective effect.

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