Monoterpenoid indole alkaloid derivative for improving memory cognition function as well as preparation method and application of monoterpenoid indole alkaloid derivative

Abstract

The invention discloses a monoterpenoid indole alkaloid derivative for improving a memory cognition function and a preparation method and application thereof, and relates to the field of pharmacy. The monoterpenoid indole alkaloid derivative comprises a monoterpenoid indole alkaloid compound with a structure as shown in a general formula I, or pharmaceutically acceptable salt or stereoisomer or prodrug molecule of the monoterpenoid indole alkaloid compound. According to the present invention, it is found for the first time that the prepared monoterpene indole alkaloid derivative can regulate and control the growth and differentiation of nerve cells, and can increase the synthesis of new proteins by inhibiting eukaryotic elongation factor 2 kinase (eEF2K) so as to enhance the growth of neurite and promote the maturation of neurons. Experimental results prove that the prepared monoterpenoid indole alkaloid derivative has application prospects in improving neurodegenerative diseases (such as Alzheimer's disease, Parkinson's disease and the like), Down's syndrome and senescence-related memory cognitive impairment. # imgabs0 #

Description

Technical Field

[0001] The present invention relates to the technical field of pharmacy, and in particular to a monoterpene indole alkaloid derivative for improving memory and cognitive function, its preparation method and application. Background Art

[0002] Neurodegenerative diseases such as Alzheimer's disease (AD), Parkinson's disease (PD), as well as Down syndrome (DS) and aging-related memory and cognitive impairment have become major challenges in the field of global public health. The common pathological features of these diseases include abnormal protein aggregation (such as β-amyloid protein, tau protein, α-synuclein), synaptic function damage, neuron death and mitochondrial dysfunction, ultimately leading to cognitive decline and loss of motor function. At present, the clinical treatment methods are mostly limited to symptom relief, lacking intervention strategies targeting the core pathological mechanisms of the diseases, and there is an urgent need to develop new therapeutic targets and drugs.

[0003] Ervatamia divaricata is a plant of the genus Ervatamia in the family Apocynaceae. This plant grows in the sparse forests in the mountains and is widely distributed in southern and southeastern China. Its leaves can clear heat and reduce blood pressure, and detoxify and reduce swelling. Its roots are used by the folk to treat traumatic injuries and headaches. Among them, alkaloid compounds are one of its main active ingredients. Some ibogaine-type alkaloids and dimer alkaloids have good biological activities such as anti-addiction and inhibition of acetylcholinesterase. Research has confirmed that the alkaloids in Ervatamia divaricata have anti-tumor activity, and also have a protective effect on the nervous system, as well as anti-inflammatory, anti-microbial, lipid-lowering, blood pressure-lowering and anti-atherosclerotic effects. However, there is currently no report on the application of monoterpene indole alkaloid derivatives as nerve differentiation inducers in the treatment of nervous system diseases. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a monoterpene indole alkaloid derivative for improving memory and cognitive function, which has the potential to treat neurodegenerative diseases including Alzheimer's disease and Parkinson's disease, provides a new treatment idea for Down syndrome and aging-related memory and cognitive impairment, and has broad application and development prospects.

[0005] In order to solve the above technical problem, in the first aspect, the monoterpene indole alkaloid derivative for improving memory and cognitive function provided by the present invention adopts the following technical solution:

[0006] A monoterpene indole alkaloid derivative for improving memory and cognitive function, comprising a monoterpene indole alkaloid compound having the structure shown in general formula I, or a pharmaceutically acceptable salt thereof, or a stereoisomer thereof, or a prodrug molecule thereof:

[0007]

[0008] In a second aspect, a pharmaceutical composition provided by the present invention adopts the following technical solution:

[0009] A pharmaceutical composition, comprising a carrier and the monoterpene indole alkaloid compound as claimed in claim 1, or a pharmaceutically acceptable salt thereof, or a stereoisomer thereof, or a prodrug molecule thereof.

[0010] Optionally, the carrier comprises one or more of excipients, emulsifiers and surfactants.

[0011] Optionally, the dosage form of the pharmaceutical composition comprises tablets, capsules, granules, injections or sprays.

[0012] In a third aspect, a preparation method of a monoterpene indole alkaloid derivative for improving memory and cognitive function provided by the present invention adopts the following technical solution:

[0013] A preparation method of a monoterpene indole alkaloid derivative for improving memory and cognitive function, which uses an organic solvent or water to extract the roots of Ervatamia divaricata to obtain a crude extract of Ervatamia divaricata; after acid extraction and alkali precipitation of the crude extract of Ervatamia divaricata, a total alkaloid part of Ervatamia divaricata is obtained; the total alkaloid part of Ervatamia divaricata is separated by column chromatography and purified by high performance liquid chromatography to obtain the monoterpene indole alkaloid dimer.

[0014] Optionally, the acid extraction and alkali precipitation comprises the following steps: the crude extract of Ervatamia divaricata is suspended in water, 8-12% hydrochloric acid aqueous solution is slowly added, the pH value is adjusted to 2-3, left standing, and neutral components are removed by chloroform extraction; the acid aqueous layer is alkalized with ammonia water to a pH value of 8-10, left standing, and extracted with chloroform, and the extraction solution is recovered under reduced pressure to obtain the total alkaloid part of Ervatamia divaricata.

[0015] Optionally, the column chromatography comprises the following steps:

[0016] The total alkaloid part of Ervatamia divaricata is subjected to silica gel column chromatography, and chloroform-methanol gradient elution is carried out at 0:100 → 100:0, V / V, and then the same fractions are analyzed and combined to obtain 14 main fractions, Fr.A to Fr.N; among them, Fr.I is separated and purified by repeated silica gel column chromatography, Sephadex LH-20 and preparative HPLC chromatographic techniques to obtain a pure product of monoterpene indole alkaloid dimer.

[0017] In a fourth aspect, the application of the monoterpene indole alkaloid derivative provided by the present invention adopts the following technical solution:

[0018] Use of a monoterpene indole alkaloid derivative, including the above-mentioned monoterpene indole alkaloid compound or a pharmaceutically acceptable salt thereof or a stereoisomer thereof, in the preparation of a drug for promoting de novo protein synthesis in cells.

[0019] Use of a monoterpene indole alkaloid derivative, including the above-mentioned monoterpene indole alkaloid compound or a pharmaceutically acceptable salt thereof or a stereoisomer thereof, in the preparation of a drug for promoting the differentiation of nerve cells.

[0020] Use of a monoterpene indole alkaloid derivative, including the above-mentioned monoterpene indole alkaloid compound or a pharmaceutically acceptable salt thereof or a stereoisomer thereof, in the preparation of a drug for preventing and treating neurodegenerative diseases (such as Alzheimer's disease, Parkinson's disease, etc.), Down syndrome, and aging-related memory and cognitive impairment.

[0021] In summary, the present invention includes at least one of the following beneficial technical effects:

[0022] 1. The monoterpene indole alkaloid derivative or composition can increase de novo protein synthesis in cells, promote the differentiation of nerve cells and the growth of neurites by inhibiting eukaryotic elongation factor 2 kinase, and is used for the prevention and treatment of neurodegenerative diseases (such as Alzheimer's disease, Parkinson's disease, etc.), Down syndrome, and aging-related memory and cognitive impairment;

[0023] 2. The monoterpene indole alkaloid derivative or composition can be used for the prevention and treatment of neurodegenerative diseases (such as Alzheimer's disease, Parkinson's disease, etc.), Down syndrome, and aging-related memory and cognitive impairment by enhancing the growth of neurites;

[0024] 3. It is first discovered in the present invention that the prepared monoterpene indole alkaloid derivative can effectively inhibit eEF2K kinase, promote de novo protein synthesis, and promote the differentiation of nerve cells; the experimental results of the present invention confirm that the prepared monoterpene indole alkaloid derivative has the potential for improving neurodegenerative diseases (such as Alzheimer's disease, Parkinson's disease, etc.), provides a new treatment idea for Down syndrome and aging-related memory and cognitive impairment, and has broad application and development prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0026] Figure 1 For compound I1 1H NMR spectrum;

[0027] Figure 2 for Compound I 13 13C NMR spectrum;

[0028] Figure 3 for Compound I 1 1H- 1 1H COSY spectrum;

[0029] Figure 4 for HSQC spectrum of Compound I;

[0030] Figure 5 for HMBC spectrum of Compound I;

[0031] Figure 6 for NOESY spectrum of Compound I;

[0032] Figure 7 for the effect of Compound I on cell viability; A: HT22 cells; B: Neuro-2a;

[0033] Figure 8 for the effect of Compound I on promoting de novo protein synthesis in HT22 cells;

[0034] Figure 9 for the effect of Compound I on promoting neural differentiation in Neuro-2a cells, A: fluorescence images; B: statistically analyzed neurite length; C: statistically analyzed cell differentiation rate;

[0035] Figure 10 for the inhibitory activity of Compound I against eEF2K kinase;

[0036] Figure 11 for the therapeutic effects of Compound I on APP / PS1 mice and D-galactose model mice.

[0037] Figure 12 for the schematic planar structure of Compound I. Detailed implementation manners

[0038] Now, various exemplary implementation manners of the present invention will be described in detail. This detailed description should not be regarded as a limitation of the present invention, but rather as a more detailed description of certain aspects, characteristics, and implementation schemes of the present invention.

[0039] It should be understood that the terms used in this invention are only for describing specific embodiments and are not intended to limit the invention. Additionally, for the numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Each intermediate value within any stated value or stated range, as well as each smaller range between any other stated value or intermediate value within the stated range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0040] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Although this invention only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of this invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the documents. In case of conflict with any incorporated document, the content of this specification shall prevail.

[0041] The term "prodrug molecule" represents a compound that is converted in vivo into the compound represented by the aforementioned general formula or specific compound. Such conversion is affected by the hydrolysis of the prodrug in the blood or enzymatic conversion in the blood or tissues into the parent structure. The prodrugs of this invention can be esters. In this invention, esters that can be used as prodrugs include phenyl esters, aliphatic (C1-24) esters, acyloxymethyl esters, carbonates, carbamates, and amino acid esters. For example, if a compound in this invention contains a hydroxyl / carboxyl group, it can be acylated to obtain a compound in the prodrug form. Other prodrug forms include phosphate esters, such as those obtained by phosphorylating the hydroxyl groups on the parent compound.

[0042] Without departing from the scope or spirit of this invention, various improvements and changes can be made to the specific embodiments of the specification of this invention, which are obvious to those skilled in the art. Other embodiments obtained from the specification of this invention are obvious to those skilled in the art. The specification and examples of this invention are merely exemplary.

[0043] Regarding the use of "comprising", "including", "having", "containing", etc. in this article, they are all open-ended terms, meaning including but not limited to.

[0044] I. Examples

[0045] Example 1:

[0046] 51.6 kg of dried Ervatamia divaricata roots (collected from Panyu District, Guangzhou City, identified by Associate Professor Zhang Ying of the School of Pharmacy, Jinan University), after being crushed, were percolated and extracted with 95% ethanol solution. The extraction solutions were combined and concentrated under reduced pressure to obtain about 3.7 kg of total extract. The total extract was suspended in water, and 10% hydrochloric acid aqueous solution was slowly added to adjust the pH value to 2 - 3. After standing, chloroform was used for extraction to remove neutral components. The acid aqueous layer was alkalized with ammonia water to pH 9, and after standing, chloroform was used for extraction. The extraction solution was concentrated under reduced pressure to recover the solvent, obtaining the chloroform fraction, that is, 103.8 g of the total alkaloid fraction. The total alkaloid fraction (103.8 g) was subjected to silica gel column chromatography (chloroform - methanol gradient elution 0:100 → 100:0, V / V). After TLC analysis, the same fractions were combined to obtain 14 main fractions (Fr.A - Fr.N). Among them, Fr.I (23.2 g) was subjected to column chromatography on Sephadex LH - 20 (chloroform - methanol), purified by ODS, and subjected to reverse - phase preparative HPLC ( Prep C18 (19×250 mm, 5 μm)), using acetonitrile: water: diethylamine (65:35:0.01%) as the mobile phase, and eluting at a flow rate of 5 mL / min to obtain the pure product I of the monoterpene indole alkaloid dimer (Compound I, purity > 98%).

[0047] II. Performance Detection Tests:

[0048] 1. Structure Identification of Monoterpene Indole Alkaloid Dimer (Compound I)

[0049] The obtained pure product I of the monoterpene indole alkaloid dimer was colorless square crystals, specific rotation: (c 1.20, CH3OH). The structure of this compound was deduced by ultraviolet spectroscopy (UV), infrared spectroscopy (IR), nuclear magnetic resonance hydrogen spectrum ( 1 1H NMR), carbon spectrum ( 13 13C NMR), two - dimensional nuclear magnetic resonance spectra ( 1 1H - 1 1H COSY, HSQC, HMBC, NOESY) and high - resolution mass spectrometry (HRMS).

[0050] The UV spectrum had maximum absorptions at 205, 223 and 301 nm, indicating the presence of a conjugated system in the structure of this compound.

[0051] The IR spectrum had characteristic absorptions at 3400, 3302, 1721, 1640, 1531 and 1454 cm -1 , indicating the presence of functional groups such as amino, carbonyl, benzene ring, etc. in the structure of this compound.

[0052] The HR - ESI - MS spectrum showed a quasi - molecular ion peak m / z 639.3300 [M + Na] +(calcd for C 39 H 44 N4O3Na: 639.3306), it can be inferred that the molecular formula of the compound is C 39 H 44 N4O3.

[0053] 1H Nuclear Magnetic Resonance ( 1 1H NMR) and Carbon-13 Nuclear Magnetic Resonance ( 13 13C NMR) data were assigned according to the signals of HSQC, and the results are shown in Table 1.

[0054] Table 1:

[0055]

[0056]

[0057] From the 1 1H NMR (600 MHz, CD3OD) spectrum of Compound I, two sets of ortho-disubstituted aromatic proton signals were found, which were [δ H 7.32 (1H, d, J = 8.3 Hz), 7.23 (1H, t, J = 8.3 Hz), 6.91 (1H, d, J = 8.3 Hz), 6.87 (1H, t, J = 8.3 Hz)] and [δ H 7.75 (1H, d, J = 7.2 Hz), 7.43 (1H, d, J = 7.2 Hz), 7.20 (1H, t, J = 7.2 Hz), 7.15 (1H, t, J = 7.2 Hz)], four alkene hydrogen signals [δ H 5.65 (1H, q, J = 6.5 Hz), 5.41 (1H, s), 5.29 (1H, q, J = 6.5 Hz), 5.12 (1H, s)], and four methyl proton signals [δ H 2.56 (3H, s), 2.21 (3H, s), 1.64 (3H, d, J = 6.5 Hz), 1.64 (3H, d, J = 6.5 Hz)].

[0058] The 13 13C NMR (150 MHz, CD3OD) of Compound I showed 39 carbon signals, including one α,β-unsaturated ketone carbon signal (δ C 192.2), one ester carbonyl carbon signal (δ C 172.9), and twenty-two alkene carbon signals (δ C(142.8, 138.7, 138.4, 138.4, 136.9, 135.6, 135.0, 130.5, 129.7, 127.4, 125.0, 123.2, 122.5, 122.0, 120.8, 120.7, 120.3, 119.6, 118.1, 113.0, 112.2, 108.8), 4 methine carbon signals (δ C 55.0, 48.6, 45.9, 37.9, 32.4), 7 methylene carbon signals (δ C 61.9, 52.9, 51.9, 49.6, 44.3, 29.4, 20.7), 4 methyl carbon signals (δ C 50.9, 45.9, 13.4, 12.3).

[0059] For compound I, 1 H- 1 H COSY spectrum shows 6 sets of proton spin coupling systems ( Figure 3 ). In the HMBC spectrum, δ H 6.91 (H-9) has a long-range correlation with δ C 138.7 (C-13), δ H 3.33, 3.21 (H-6) has a long-range correlation with δ C 135.0 (C-2) / 123.2 (C-7) / 129.7 (C-8), δ H 3.22, 2.48 (H-14) has a long-range correlation with δ C 135.0 (C-2) / 192.2 (C-3), δ H 3.66 (H-15) / 1.64 (H-18) has a long-range correlation with δ C 138.4 (C-20), δ H 5.29 (H-19) has a long-range correlation with δ C 51.9 (C-21), δ H 2.61 (H-16) / 2.56 (H-23) has a long-range correlation with C-22 (δ C 172.9), thus determining the planar structure of part of unit A. In part of unit B, δ H 7.75 (H-9') has a long-range correlation with δ C 108.8 (C-7') / 122.5 (C-11') / 136.9 (C-13'), δ H 1.64 (H-18') has a long-range correlation with δ C 135.6 (C-20'), δ H 5.65 (H-19') has a long-range correlation with δC 37.9 (C-15') / 61.9 (C-21') has a long-range correlation, δ H 4.21 (H-15') correlates with δ C 142.8 (C-16') has a long-range correlation, δ H 5.41, 5.12 (H-17') correlate with δ C 138.4 (C-2') / 37.9 (C-15') has a long-range correlation, δ H 2.21 (H-22') correlates with δ C 52.9 (C-3') / 61.9 (C-21') has a long-range correlation, from which the planar structure of unit B can be determined. In addition, δ H 3.73 (H-5) / 3.76, 3.08 (H-21) also correlates with δ C 49.6 (C-6') has a long-range correlation, proving that unit A and unit B are connected by N-4-C-6' (refer to Figure 12 ), thus, the planar structure of compound I is determined.

[0060] In the NOESY spectrum, δ in unit A H 3.73 (H-5) correlates with δ H 3.21 (H-6α) has a NOE correlation, indicating that these two sets of protons are on the same side, δ H 2.48 (H-14α) correlates with δ H 3.66 (H-15) has a NOE correlation, indicating that these two sets of protons are also on the same side. δ H 3.66 (H-15) correlates with δ H 1.64 (H-18) has a NOE correlation, thereby determining that the double bond where C-19-C-20 is located is of the E configuration. According to the chemical shift of the methoxy group (H-23) (δ H 2.56) shifting upfield compared to a normal methoxy group, it is because H-23 is directly above the indole ring and is shielded by the indole ring, thus determining that the configuration at C-16 is S * . In the part of unit B, δ H 4.21 (H-15') correlates with δ H 1.64 (H-18') has a NOE correlation, which can determine that the double bond at C-19'-C-20' is of the E configuration, thus determining the relative configuration of compound I (as shown in the following formula).

[0061]

[0062] Subsequent X-ray diffraction experiments on single crystals of Compound I [CuKα; T = 100.00(10) K; Flack parameter = 0.01(9)] further verified the absolute configuration of Compound I. In summary, Compound I is a new dimer with unique connection sites. Its novelty lies in that the strychnos-type alkaloid undergoes ring-opening at the 5,6 positions, the C-5 position is methylated, and the C-6 position is connected to the N-4 position of the vobasine-type alkaloid, named ervadivasamine A (as shown in the following formula).

[0063]

[0064] 2. Determination of the cytotoxicity of Compound I by the CCK8 method

[0065] HT22 cells (iCell Bioscience Inc, iCell-m020) were cultured in high-sucrose DMEM medium (Thermo, C11995500BT), supplemented with 10% fetal bovine serum (FBS) and 1% penicillin-streptomycin (P / S), and cultured in a humidified incubator at 5% CO2 and 37 °C. When treating the cells, 0 μM (DMSO), 1.25 μM, 2.5 μM or 5 μM of Compound / A-484954 were given respectively. After treatment for 24 hours or 30 minutes, the cells were collected for CCK-8 assay or Western blotting analysis.

[0066] Neuro-2a cells (ATCC, Manassas, VA, United States) were cultured in high-sucrose DMEM medium (Thermo, C11995500BT), supplemented with 10% fetal bovine serum (FBS) and 1% penicillin-streptomycin (P / S), and cultured in a humidified incubator at 5% CO2 and 37 °C. When treating the cells, 0 μM (DMSO), 1.25 μM, 2.5 μM or 5 μM of Compound / RA were given respectively. After treatment for 48 hours, the cells were collected for CCK-8 assay or immunocytochemistry analysis.

[0067] HT22 / Neuro-2a cell suspension (100 μL) was seeded into 96-well plates and incubated overnight in a cell culture incubator (37 °C, 5% CO2). The next day, the test compound was added and incubation continued for 24 hours. Subsequently, the medium was replaced with DMEM containing 10% Cell Counting Kit-8 (Targetmol, C0005), and further cultured for 1 hour. Then, the absorbance at 450 nm was measured using a microplate reader (Thermo, Multiskan FC type) to calculate cell viability.

[0068] From Figure 7 As can be seen from A-B in Figure Figure 7 , the compounds of the present invention, compound I of the present invention, have no obvious effect on the survival rate of HT22 cells and Neuro-2a cells in the range of 1.25 - 5 μM, indicating that these compounds have no cytotoxicity at a concentration of 5 μM or below.

[0069] 3. Compound I can significantly promote de novo protein synthesis and reduce the phosphorylation level of eEF2

[0070] Puromycin is an aminoglycoside antibiotic produced after fermentation and metabolism by Streptomyces niger. Structurally, it is similar to the 3'-end of the aminoacyl-tRNA molecule and can bind to the A-site of ribosomes and be inserted into the C-terminus of the growing peptide chain during protein synthesis. After the peptide chain is labeled with puromycin, it will be released from the ribosome and translation will terminate prematurely.

[0071] The HT22 cell suspension was inoculated into 100 mm culture dishes and allowed to adhere overnight in a cell culture incubator (37 °C, 5% CO2). It was divided into a control group (DMSO), a positive control group (A-484954), and a 5 μM compound I treatment group. At the same time, 1 μM puromycin (540222; Sigma) was added and the cells were collected after co-treatment for 30 minutes.

[0072] Detection of de novo protein content: Western blot (WB) was used to detect the content of puromycin in the control group (DMSO), the positive control group (A-484954), and the 5 μM compound I treatment group.

[0073] Detection of eEF2 phosphorylation level: Western blot (WB) was performed for detection. The antibodies used included: eEF2 antibody (Proteintch, 67550-1-Ig, 1:2000); eEF2 (Thr56) antibody (CST, 2331S, 1:1000); puromycin antibody (CST, MABE343, 1:2000); β-actin (Abbkine, A01010, 1:1000).

[0074] From Figure 8 As can be seen from the statistical chart, compound I significantly promoted de novo protein synthesis in HT22 cells and at the same time reduced the phosphorylation level of eEF2.

[0075] 4. Compound I can significantly promote neural differentiation

[0076] The Neuro-2a cell suspension was inoculated into 96-well plates and allowed to adhere overnight in a cell culture incubator (37 °C, 5% CO2). It was divided into a control group, a 5 μM RA positive control group, and a 5 μM compound I treatment group, and incubated for 48 hours for immunofluorescence staining.

[0077] The antibodies used included β-tubulin III (Sigma, T8578, 1:2000).

[0078] Figure 9 Fluorescent picture A taken using fluorescence microscopy imaging technology was shown, and the images were quantitatively analyzed using ImageJ (1.54d) software to obtain statistical graph B (cell differentiation rate) and graph C (total neurite length), thereby quantitatively evaluating the experimental results.

[0079] From Figure 9 it can be seen that compound I significantly promoted the differentiation and growth of Neuro-2a neurites.

[0080] 5. Compound I can inhibit the activity of eEF2K kinase

[0081] Activity-based eEF2K kinase detection was performed using the radioactive HotSpot TM platform for compound screening and characterization. This experiment involved preparing a mixture containing eEF2K kinase / substrate and cofactors in a buffer. The buffer components included 20 mM Hepes (pH 7.5), 10 mM MgCl2, 1 mM EGTA, 0.01% Brij35, 0.02 mg / ml BSA, 0.1 mM Na3VO4, 2 mM DTT, and 1% DMSO. Approximately 20 minutes after adding the test compound, 33 PATP (PerkinElmer, Waltham, MA) was introduced using Echo550 acoustic technology 50 to bring its final concentration to 10 μM. The reaction was carried out at room temperature for 120 minutes, and the kinase activity was evaluated using the P81 filter paper binding method. The IC

[0082] From Figure 10 it can be seen that compound I can inhibit the activity of eEF2K kinase.

[0083] 6. Compound I increases the exploration time ratio of APP / PS1 mice on novel objects

[0084] In this example, male APP / PS1 double transgenic mice (purchased from Beijing Huafukang Biotechnology Co., Ltd.) were used. These mice are a classical transgenic mouse model of Alzheimer's disease (AD) and start to show cognitive impairment at 4 - 5 months of age. Male 6 - month - old APP / PS1 transgenic AD mice and wild - type control mice (WT) were randomly grouped (6 mice in each group) and intraperitoneally injected with compound I (10 mg / kg) once a day for four weeks.

[0085] The Novel Object Recognition Test (NOR) is a classical behavioral paradigm widely used in neuroscience to evaluate the learning and memory abilities of animals (such as rodents). Its principle is based on the natural exploratory tendency of animals towards novel things (i.e., "novelty preference"). By quantifying the difference in exploration time of animals towards old and new objects, it reflects the strength of their recognition memory. Normal mice tend to explore new objects. The novel object experimental device is a 40 cm×40 cm white box, which is divided into three stages: the adaptation stage (the mouse adapts in an empty box for 10 minutes); the same - object stage (the mouse freely explores in a box with two identical objects for 10 minutes); the new - object stage (one of the two identical objects is replaced with a new object of the same material and similar volume, and the mouse freely explores in a box with two different objects for 10 minutes). Each group of mice was tested according to the above steps, and after the experiment, the exploration - time ratios of the mice on old and new objects were statistically analyzed.

[0086] As Figure 11 shown in A of, WT mice can recognize new objects, while APP / PS1 transgenic AD mice cannot, indicating that the memory and cognitive functions of APP / PS1 transgenic AD mice are impaired; after continuous intraperitoneal injection of compound I for four weeks, APP / PS1 mice can recognize new objects, suggesting that compound I has the activity to promote the object - recognition memory ability of AD mice and improve memory and cognitive impairment.

[0087] 7. Compound I increases the exploration - time ratio of D - galactose - model mice on new objects

[0088] D-galactose exists in the human body and some foods. However, after continuous high-dose intake, excessive accumulation of D-galactose in the body will enhance oxidative stress and generate reactive oxygen species (ROS), which will promote damage to nerve cells after oxidative stress. Further development will lead to nerve inflammation and neurodegenerative diseases, etc. This model simulates a physiological characteristic close to natural aging during the modeling process, including decreased memory and cognitive function, and a decrease in the number of hippocampal pyramidal neurons, etc.

[0089] In this example, male C57BL / 6 mice (purchased from Beijing Huafukang Biotechnology Co., Ltd.) were used. Male 5-month-old C57BL / 6 mice were randomly divided into three groups (6 mice in each group), namely the solvent group, the D-galactose (100 mg / kg) model group, and the D-galactose (100 mg / kg) + compound I (10 mg / kg) group, and were injected intraperitoneally once a day for eight consecutive weeks. D-galactose (Targetmol, T0591)

[0090] The mice in each group were subjected to the novel object test. As can be seen from Figure 11 B, the mice in the solvent group could recognize the novel object, while the mice in the D-galactose model group could not, indicating that the memory and cognitive function of the mice in the D-galactose model group was impaired; and the D-galactose model mice after continuous intraperitoneal injection of compound I for eight weeks could recognize the novel object, indicating that compound I has the activity of promoting the object recognition memory ability of aging model mice and improving memory and cognitive impairment.

[0091] The data of the experimental results in the above performance detection tests 2-7 were expressed as mean±S.E.M, and were statistically processed by ANOVA test and Student’s -t test. When P<0.05, it was statistically significant, *P<0.05, **P<0.01, ***P<0.001, ****P<0.0001.

[0092] The above-described embodiments are only descriptions of the preferred embodiments of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention should fall within the protection scope determined by the claims of the present invention.

Claims

1. A monoterpene indole alkaloid derivative for improving memory and cognitive function, characterized in that, Comprising a monoterpene indole alkaloid compound having the structure shown in general formula I, or a pharmaceutically acceptable salt thereof, or a stereoisomer thereof, or a prodrug molecule thereof:

2. A pharmaceutical composition, characterized in that: Comprising a carrier and the monoterpene indole alkaloid compound as claimed in claim 1, or a pharmaceutically acceptable salt thereof, or a stereoisomer thereof, or a prodrug molecule thereof.

3. The pharmaceutical composition according to claim 2, wherein: The carrier comprises one or more of excipients, emulsifiers and surfactants.

4. A pharmaceutical composition according to claim 2, wherein: The dosage form of the pharmaceutical composition is tablets, capsules, granules, injections or sprays.

5. A preparation method of a monoterpene indole alkaloid derivative for improving memory and cognitive function as described in claim 1, characterized in that: The roots of Ervatamia divaricata (L.) Burk. are extracted with an organic solvent or water to obtain a crude extract of Ervatamia divaricata (L.) Burk.; after acid extraction and alkali precipitation of the crude extract of Ervatamia divaricata (L.) Burk., the total alkaloid part of Ervatamia divaricata (L.) Burk. is obtained; the total alkaloid part of Ervatamia divaricata (L.) Burk. is separated by column chromatography and purified by high performance liquid chromatography to obtain the monoterpene indole alkaloid dimer.

6. The preparation method of a monoterpene indole alkaloid derivative for improving memory and cognitive function according to claim 5, characterized in that, The acid extraction and alkali precipitation comprises the following steps: The crude extract of Ervatamia divaricata (L.) Burk. is suspended in water, 8-12% hydrochloric acid aqueous solution is slowly added, the pH value is adjusted to 2-3, left standing, and neutral components are removed by chloroform extraction; the acid aqueous layer is alkalized with ammonia water to pH 8-10, left standing, and extracted with chloroform, and the extract is concentrated under reduced pressure to recover the solvent to obtain the total alkaloid part of Ervatamia divaricata (L.) Burk.

7. The preparation method of a monoterpene indole alkaloid derivative for improving memory and cognitive function according to claim 5, characterized in that, The column chromatography comprises the following steps: The total alkaloid part of Ervatamia divaricata (L.) Burk. is subjected to silica gel column chromatography, eluted with a chloroform-methanol gradient of 0:100 → 100:0, V / V, and then the same fractions are analyzed and combined to obtain 14 main fractions, Fr.A to Fr.N; among them, Fr.I is separated and purified by the chromatographic techniques of Sephadex LH-20 and preparative HPLC to obtain the pure product of the monoterpene indole alkaloid dimer.

8. Use of the monoterpene indole alkaloid compound as claimed in claim 1, or a pharmaceutically acceptable salt thereof, or a stereoisomer thereof, in the preparation of a drug for promoting the synthesis of new proteins in cells.

9. Use of the monoterpene indole alkaloid compound as claimed in claim 1, or a pharmaceutically acceptable salt thereof, or a stereoisomer thereof, in the preparation of a drug for promoting the differentiation of nerve cells.

10. Use of the monoterpene indole alkaloid compound as claimed in claim 1, or a pharmaceutically acceptable salt thereof, or a stereoisomer thereof, in the preparation of a drug for preventing and treating Alzheimer's disease, Parkinson's disease and Down syndrome and aging-related memory and cognitive impairment.

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