阅读说明：本技术 一种益母草碱冰片衍生物、制备方法及其应用 (Leonurine borneol derivative, preparation method and application thereof ) 是由 李峰 宋艳 宋晓峰 李文保 刘晓坤 张姗姗 于 2021-09-28 设计创作，主要内容包括：本发明提供一种益母草碱冰片衍生物,所述益母草碱冰片衍生物为B1或B2所示的化合物或其立体异构体或其药学上可接受的盐形式,本发明还提供上述衍生物的制备方法及其在防治神经系统疾病或心脑血管疾病的药物中的应用。本发明提供的益母草碱冰片衍生物具有显著的神经保护作用,能够修复神经细胞损伤,还能够起到明显降脂的功能,因此具有显著治疗和预防神经系统、心脑血管疾病的药理学活性,对于开发新型的预防或治疗神经系统、心脑血管疾病药物具有重要的意义。(The invention provides an leonurine borneol derivative, which is a compound shown as B1 or B2 or a stereoisomer thereof or a pharmaceutically acceptable salt form thereof, and also provides a preparation method of the derivative and application of the derivative in medicines for preventing and treating nervous system diseases or cardiovascular and cerebrovascular diseases. The leonurine borneol derivative provided by the invention has a remarkable neuroprotective effect, can repair nerve cell injury, and also has a remarkable lipid-lowering function, so that the leonurine borneol derivative has a remarkable pharmacological activity for treating and preventing nervous system and cardiovascular and cerebrovascular diseases, and has an important significance for developing novel medicaments for preventing or treating the nervous system and the cardiovascular and cerebrovascular diseases.)

1. An leonurine borneol derivative is characterized in that: the leonurine borneol derivative is a compound shown as B1 or B2 or a stereoisomer or a pharmaceutically acceptable salt form thereof:

。

2. the method of preparing the leonurine borneol derivative according to claim 1, characterized in that:

the preparation method of the B1 comprises the following steps:

(1) preparation of M-1

Adding camphene, 2-bromoethanol and montmorillonite K-10 into dichloromethane, and stirring at room temperature for 24 hours to obtain M-1;

the molar ratio of camphene to 2-bromoethanol is 1: 1.1; the mass ratio of the camphene to the montmorillonite K-10 is 1: 2; the mass-volume ratio of camphene to dichloromethane is 1g:13.3 mL;

(2) preparation of M-2

Dissolving syringic acid in dichloromethane to obtain dichloromethane solution of syringic acid, sequentially adding potassium hydroxide, potassium carbonate, tetrabutylammonium bromide and water, slowly dropwise adding the dichloromethane solution containing M-1 under stirring, completing dropwise addition for 30 minutes, and reacting at room temperature for 24 hours to obtain M-2;

the molar ratio of the syringic acid to the potassium hydroxide to the potassium carbonate to the tetrabutylammonium bromide to the M-1 is 10:18:10:1: 10;

the mass volume ratio of the tetrabutylammonium bromide to the water is 1g:30 mL;

in the dichloromethane solution of the syringic acid, the mass-volume ratio of the syringic acid to the dichloromethane is 1g:5 mL;

the mass-volume ratio of M-1 to dichloromethane of the dichloromethane solution containing M-1 is 1g:1.28 mL;

(3) preparation of M-4

Dissolving M-2 in DCM at room temperature, sequentially adding M-3, 4-dimethylaminopyridine p-toluenesulfonate and N, N' -diisopropylcarbodiimide, and reacting for 5 hours to obtain M-4;

the molar ratio of the M-2, the M-3, the 4-dimethylaminopyridine p-toluenesulfonate to the N, N' -diisopropylcarbodiimide is 1:1.5:2: 2;

the mass-to-volume ratio of M-2 to DCM is 1g: 15.9 mL;

(4) to obtain B1

Dissolving M-4 in dichloromethane, dripping trifluoroacetic acid at 0 ℃, stirring for 5 min, heating to room temperature, and reacting for 8 h to obtain B1;

the mass-volume ratio of the M-4 to the dichloromethane is 1 mg: 0.05 mL; the volume ratio of the dichloromethane to the trifluoroacetic acid is 20: 1;

the preparation method of the B2 comprises the following steps:

(1) preparation of M-5

Dissolving syringic acid in dichloromethane to obtain a dichloromethane solution of syringic acid, sequentially adding potassium hydroxide, potassium carbonate, tetrabutylammonium bromide and water, slowly dropwise adding a dichloromethane solution of bromoborneol under stirring, completing dropwise addition within 30 minutes, and reacting at room temperature for 24 hours to obtain M-5;

the molar ratio of the syringic acid to the potassium hydroxide to the potassium carbonate to the tetrabutylammonium bromide to the bromoborneol is 10:18:10:1: 10;

the mass volume ratio of the tetrabutylammonium bromide to the water is 1g:30 mL;

in the dichloromethane solution of the syringic acid, the mass-volume ratio of the syringic acid to the dichloromethane is 1g:5 mL;

in the dichloromethane solution of the bromoborneol, the mass volume ratio of the bromoborneol to the dichloromethane is 1g: 1.54 mL;

(2) preparation of M-6

Dissolving M-5 in DCM at room temperature, sequentially adding M-3, 4-dimethylaminopyridine p-toluenesulfonate and N, N' -diisopropylcarbodiimide, and reacting at room temperature for 5 h to obtain M-6;

the molar ratio of the M-5, the M-3, the 4-dimethylaminopyridine p-toluenesulfonate to the N, N' -diisopropylcarbodiimide is 1:1.5:2: 2;

the mass-to-volume ratio of the M-5 to the DCM is 1g:18.2 mL;

(3) preparation B2

Dissolving M-6 in dichloromethane, dripping trifluoroacetic acid at 0 ℃, stirring for 5 min, heating to room temperature, and reacting for 8 h to obtain B2;

the mass-volume ratio of the M-6 to the dichloromethane is 1 mg: 0.05 mL; the volume ratio of the dichloromethane to the trifluoroacetic acid is 20: 1;

the structural formulas of M-1, M-2, M-3, M-4, M-5 and M-6 are as follows:

。

3. the use of the leonurine borneol derivative according to claim 1 in the preparation of medicaments for preventing and treating nervous system diseases or cardiovascular and cerebrovascular diseases.

Technical Field

The invention belongs to the technical field of medicines, and particularly relates to an leonurine borneol derivative, a preparation method thereof and application thereof in medicines for preventing and treating nervous system diseases or cardiovascular and cerebrovascular diseases.

Background

Stroke is a major disease seriously harming human health and life safety in the world at present, and has the characteristics of high morbidity, high disability rate and high mortality; stroke is a group of diseases in which brain tissue is damaged due to sudden rupture of cerebral blood vessels or the inability of blood to flow into the brain due to vascular occlusion, and includes ischemic and hemorrhagic strokes. The incidence rate of ischemic stroke is higher than hemorrhagic stroke, and accounts for 60-70% of the total stroke. In the world, more than one thousand new strokes occur every year, and investigation shows that urban and rural combined stroke becomes the first cause of death in China and is also the leading cause of disability of adults in China, so that serious burden is brought to the society and families, and effective stroke prevention and treatment measures are urgently needed. There are different treatment modes for stroke according to the occurrence part, wherein the drug therapy is one of the main treatment modes adopted at present, including thrombolysis, antiplatelet therapy, early anticoagulation, neuroprotection and the like. Although great progress has been made in the research of drugs for treating stroke, many problems remain unsolved: such as strict time window requirements of thrombolytic therapy, drug selection and combined use of anti-coagulation and defibrination therapy, clinical effectiveness and safety of neuroprotective drugs, and the like. Therefore, a safe and effective medicament with a wider treatment window is urgently needed for treating the cerebral apoplexy clinically.

Leonurine is firstly separated from motherwort in 1930, has the functions of promoting blood circulation to disperse blood clots, inducing diuresis to alleviate edema, exciting uterus, enhancing myocardial contractility, exciting respiration, protecting cardiac blood vessels, protecting central nervous system, etc., and may have the functions of resisting oxidation, resisting apoptosis, regulating mitochondrial function, resisting inflammation, etc.

The borneol is crystal extracted from resin and volatile oil processed product of borneol spice plant borneol tree, and the borneol is pungent and bitter in taste and slightly cold in nature; heart meridian entered; the product has effects of inducing resuscitation, refreshing mind, clearing heat, removing toxic substance, improving eyesight, and removing nebula, and can be used for treating fever, hyperpyrexia, coma, apoplexy, phlegm syncope, convulsion, summer-heat dampness covering resuscitation, pharyngitis, deafness, aphtha, swelling of teeth, skin ulcer, carbuncle, malnutritional hemorrhoid, conjunctival congestion, swelling and pain, nebula, and eye covering.

No beneficial matrine borneol derivative is reported in the prior art.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides an leonurine borneol derivative, a preparation method and application thereof in medicines for preventing and treating nervous system diseases or cardiovascular and cerebrovascular diseases, and the following aims are achieved:

the leonurine borneol derivative has a nerve protection effect and can repair nerve cell damage; has effects of reducing cerebral infarction area and decreasing neurobehavioral score.

In order to solve the technical problems, the invention adopts the following technical scheme:

an leonurine borneol derivative, which is a compound shown as B1 or B2 or a stereoisomer thereof or a pharmaceutically acceptable salt form thereof:

the following is a further improvement of the above technical solution:

the preparation method of the B1 comprises the following steps:

(1) preparation of M-1

Adding camphene, 2-bromoethanol and montmorillonite K-10 into dichloromethane, and stirring at room temperature for 24 hours to obtain M-1;

the molar ratio of camphene to 2-bromoethanol is 1: 1.1; the mass ratio of the camphene to the montmorillonite K-10 is 1: 2; the mass-volume ratio of camphene to dichloromethane is 1g:13.3 mL;

(2) preparation of M-2

Dissolving syringic acid in dichloromethane to obtain dichloromethane solution of syringic acid, sequentially adding potassium hydroxide, potassium carbonate, tetrabutylammonium bromide and water, slowly dropwise adding the dichloromethane solution containing M-1 under stirring, completing dropwise addition for 30 minutes, and reacting at room temperature for 24 hours to obtain M-2;

the molar ratio of the syringic acid to the potassium hydroxide to the potassium carbonate to the tetrabutylammonium bromide to the M-1 is 10:18:10:1: 10;

the mass volume ratio of the tetrabutylammonium bromide to the water is 1g:30 mL;

in the dichloromethane solution of the syringic acid, the mass-volume ratio of the syringic acid to the dichloromethane is 1g:5 mL;

the mass-volume ratio of M-1 to dichloromethane of the dichloromethane solution containing M-1 is 1g:1.28 mL;

(3) preparation of M-4

Dissolving M-2 in DCM at room temperature, sequentially adding M-3, 4-dimethylaminopyridine p-toluenesulfonate and N, N' -diisopropylcarbodiimide, and reacting for 5 hours to obtain M-4;

the molar ratio of the M-2, the M-3, the 4-dimethylaminopyridine p-toluenesulfonate to the N, N' -diisopropylcarbodiimide is 1:1.5:2: 2;

the mass-to-volume ratio of M-2 to DCM is 1g: 15.9 mL;

(4) to obtain B1

Dissolving M-4 in dichloromethane, dripping trifluoroacetic acid at 0 ℃, stirring for 5 min, heating to room temperature, and reacting for 8 h to obtain B1;

the mass-volume ratio of the M-4 to the dichloromethane is 1 mg: 0.05 mL; the volume ratio of the dichloromethane to the trifluoroacetic acid is 20: 1;

the preparation method of the B2 comprises the following steps:

(1) preparation of M-5

Dissolving syringic acid in dichloromethane to obtain a dichloromethane solution of syringic acid, sequentially adding potassium hydroxide, potassium carbonate, tetrabutylammonium bromide and water, slowly dropwise adding a dichloromethane solution of bromoborneol under stirring, completing dropwise addition within 30 minutes, and reacting at room temperature for 24 hours to obtain M-5;

the molar ratio of the syringic acid to the potassium hydroxide to the potassium carbonate to the tetrabutylammonium bromide to the bromoborneol is 10:18:10:1: 10;

the mass volume ratio of the tetrabutylammonium bromide to the water is 1g:30 mL;

in the dichloromethane solution of the syringic acid, the mass-volume ratio of the syringic acid to the dichloromethane is 1g:5 mL;

in the dichloromethane solution of the bromoborneol, the mass volume ratio of the bromoborneol to the dichloromethane is 1g: 1.54 mL;

(2) preparation of M-6

Dissolving M-5 in DCM at room temperature, sequentially adding M-3, 4-dimethylaminopyridine p-toluenesulfonate and N, N' -diisopropylcarbodiimide, and reacting at room temperature for 5 h to obtain M-6;

the molar ratio of the M-5, the M-3, the 4-dimethylaminopyridine p-toluenesulfonate to the N, N' -diisopropylcarbodiimide is 1:1.5:2: 2;

the mass-to-volume ratio of the M-5 to the DCM is 1g:18.2 mL;

(3) preparation B2

Dissolving M-6 in dichloromethane, dripping trifluoroacetic acid at 0 ℃, stirring for 5 min, heating to room temperature, and reacting for 8 h to obtain B2;

the mass-volume ratio of the M-6 to the dichloromethane is 1 mg: 0.05 mL; the volume ratio of the dichloromethane to the trifluoroacetic acid is 20: 1.

The structural formulas of M-1, M-2, M-3, M-4, M-5 and M-6 are as follows:

。

the pharmaceutically acceptable salts of the leonurine borneol derivatives comprise inorganic acid and organic acid derived salts; inorganic and organic acids include hydrochloric, hydrobromic, sulfuric, phosphoric, methanesulfonic, trifluoromethanesulfonic, benzenesulfonic, p-toluenesulfonic, 1-naphthalenesulfonic, 2-naphthalenesulfonic, acetic, trifluoroacetic, malic, tartaric, citric, lactic, oxalic, succinic, fumaric, maleic, benzoic, salicylic, phenylacetic and mandelic acids.

The invention also provides the application of the leonurine borneol derivative in medicaments for preventing and treating nervous system diseases or cardiovascular and cerebrovascular diseases.

The nervous system diseases include apoplexy, Alzheimer disease, Parkinson disease, cerebral palsy, brain atrophy, hypomnesis, insomnia, amnesia, neurasthenia, epilepsy, schizophrenia, confusion, and attention deficit disorder; the cardiovascular and cerebrovascular diseases comprise hyperlipidemia, hypertension, hyperglycemia, atherosclerosis, cerebral arteriosclerosis, transient ischemic attack, and multiple sclerosis.

Compared with the prior art, the invention has the beneficial effects that:

pharmacological experiments prove that the derivative based on the leonurine borneol structure has the nerve protection effect, can repair nerve cell injury, and also has the function of obviously reducing blood fat, so that the derivative has the pharmacological activity of remarkably treating and preventing nervous system and cardiovascular and cerebrovascular diseases.

In a PC12 nerve cell injury model caused by oxygen sugar deprivation, compared with a leonurine group, the compounds B1 and B2 can obviously improve the survival rate of nerve cells, and have the same effect as a positive medicine Baicalein;

the compounds B1 and B2 can effectively reduce the cerebral infarction area and improve the neurobehavioral effect, and the effect of the compounds B1 and B2 at the concentration of 20 mg/kg is better than that of the positive drug group edaravone.

Drawings

FIG. 1 is a bar graph of the cerebral infarction area of the derivatives B1 and B2 caused by transient cerebral ischemia of rats;

FIG. 2 is a neuro-behavioral score of derivatives B1, B2 after transient cerebral ischemia in rats;

FIG. 3 is a graph showing the improvement of transient cerebral ischemia in rats by derivatives B1 and B2.

Detailed Description

The following embodiments better illustrate the present invention, but the present invention is not limited to the following examples.

Example 1: the synthetic route of M-1 is as follows:

adding camphene (15.0g, 0.1mol), 2-bromoethanol (13.6g, 0.11mol) and montmorillonite K-10 (30.0 g) into dichloromethane (200 mL), stirring at room temperature for 24 hours, filtering after the reaction is completed, washing a filter cake with saturated saline (100 mL), drying with anhydrous sodium sulfate, concentrating under reduced pressure, and performing column chromatography to obtain colorless oil M1 with the yield of 72%; ESI-MS: (M/z,%) = 260 [ M + H]⁺。

Example 2: the synthetic route of M-2 is as follows:

dissolving syringic acid (5.94 g, 30 mmol) in dichloromethane (30 mL) to obtain a dichloromethane solution of syringic acid, sequentially adding potassium hydroxide (3.0 g, 54 mmol), potassium carbonate (4.1 g, 30 mmol), tetrabutylammonium bromide (1.0 g,3 mmol) and water (30 mL), slowly dropwise adding a dichloromethane (10 mL) solution containing M-1 (7.8 g, 30 mmol) under stirring, dropping for 30 minutes, reacting at room temperature for 24 hours, adjusting pH after the reaction is completed = 5, separating an organic layer, and separating an organic phaseWashing with 30mL of water, concentrating to dryness after washing with water, and performing column chromatography to obtain M-2 with the yield of 51%.¹H NMR (500 MHz, DMSO-d ₆) δ = 7.28 (s, 2H), 4.13 (t, 2H), 3.81 (s, 6H), 3.76 (t, 2H), 3.04 (m, 1H), 1.86-1.55 (m, 7H), 1.01 (s, 3H), 0.97 (s, 6H). ESI-MS：（m/z，%）= 379 [M+H]⁺。

Example 3: the synthetic route of M-4 is as follows:

dissolving M-2 (6.3 g, 16.66 mmol) in 100mL DCM at room temperature, sequentially adding M-3 (6 g, 24.98 mmol), 4-dimethylaminopyridine p-toluenesulfonate (9.8 g, 33.32 mmol) and N, N' -diisopropylcarbodiimide (4.2 g, 33.32 mmol), reacting for 5 h, washing with water, extracting with DCM, collecting the lower solution, evaporating to dryness, and performing column chromatography to obtain white foamy solid M-4 with yield of 67%.

¹H NMR (500 MHz, DMSO-d ₆) δ = 9.31 (s, 1H), 8.33 (s, 1H), 7.20 (s, 2H), 4.24-4.20 (m, 1H), 4.13 (t, 2H), 4.02 (q, 1H), 3.80 (s, 6H), 3.75 (t, 2H), 3.04 (m, 1H), 1.98-1.56 (m, 13H), 1.46 (s, 9H), 1.37 (s, 9H), 1.01 (s, 3H), 0.97 (s, 6H). ESI-MS：（m/z，%）= 692 [M+H]⁺。

Example 4: the synthetic route of B1 is as follows:

dissolving M-4 (200 mg, 0.29 mmol) in 10mL dichloromethane, dripping 0.5 mL trifluoroacetic acid at 0 ℃, stirring for 5 min, raising the temperature to room temperature for reacting for 8 h, evaporating the solvent to remove the trifluoroacetic acid after the reaction is finished, adding 20 mL water, extracting an aqueous phase with dichloromethane (10 mL x 3), and evaporating the aqueous phase to dryness to obtain a solid B1 with the yield of 92%.

¹H NMR (500 MHz, CD₃OD) δ = 7.36 (s, 2H), 5.36 (dd, 1H), 4.39 (t, 2H), 3.91 (s, 6H), 4.13 (t, 2H), 3.79 (t, 2H), 3.66-3.54 (m, 4H), 3.04 (m, 1H), 1.89-1.57 (m, 11H), 1.00 (s, 3H), 0.97 (s, 6H). ESI-MS：（m/z，%）= 492 [M+H]⁺。

Example 5: the synthetic route of M-5 is as follows:

dissolving syringic acid (5.94 g, 30 mmol) in dichloromethane (30 mL) to obtain a dichloromethane solution of syringic acid, sequentially adding potassium hydroxide (3.0 g, 54 mmol), potassium carbonate (4.1 g, 30 mmol), tetrabutylammonium bromide (1.0 g,3 mmol) and water (30 mL), slowly dropwise adding a dichloromethane (10 mL) solution of bromoborneol (6.5 g, 30 mmol) while stirring, completing the dropwise addition within 30 minutes, reacting at room temperature for 24 hours, adjusting the pH after the reaction is completed to = 5, separating an organic layer, washing an organic phase with water, wherein the amount of water is 30mL, concentrating to be dry after washing, and performing column chromatography to obtain M-5, wherein the yield is 46%.

¹H NMR (500 MHz, DMSO-d ₆) δ = 7.29 (s, 2H), 3.80 (s, 6H), 3.34 (m, 1H), 2.06-1.85 (m, 2H), 1.66-1.45 (m, 5H), 0.91 (s, 3H), 0.87 (s, 6H). ESI-MS：（m/z，%）= 335 [M+H]⁺。

Example 6: the synthetic route of M-6 is as follows:

dissolving M-5 (5.5 g, 16.66 mmol) in 100mL DCM at room temperature, adding M-3 (6 g, 24.98 mmol), 4-dimethylaminopyridine p-toluenesulfonate (9.8 g, 33.32 mmol) and N, N' -diisopropylcarbodiimide (4.2 g, 33.32 mmol) in sequence, reacting for 5 h at room temperature, washing with water, extracting with DCM, collecting the lower solution, evaporating to dryness, and performing column chromatography to obtain a white foamy solid M-6 with the yield of 61%.¹H NMR (500 MHz, DMSO-d ₆) δ = 9.30 (s, 1H), 8.36 (s, 1H), 7.15 (s, 2H), 4.26-4.21 (m, 1H), 4.02 (q, 1H), 3.80 (s, 6H), 3.34 (m, 1H), 2.06-1.85 (m, 2H), 1.68-1.51 (m, 9H), 1.46 (s, 9H), 1.43 (s, 9H), 0.92 (s, 3H), 0.87 (s, 6H). ESI-MS：（m/z，%）= 648 [M+H]⁺。

Example 7: the synthetic route of B2 is as follows:

dissolving M-6 (200 mg, 0.31 mmol) in 10mL dichloromethane, dropping 0.5 mL trifluoroacetic acid at 0 ℃, stirring for 5 min, raising the temperature to room temperature for reaction for 8 h, evaporating the solvent after the reaction to remove the trifluoroacetic acid, adding 20 mL water, extracting the aqueous phase with dichloromethane (10 mL x 3), evaporating the aqueous phase to dryness to obtain solid B2, wherein the yield is 95%.

¹H NMR (500 MHz, CD₃OD) δ = 7.46 (s, 2H), 5.38 (dd, 1H), 3.83 (s, 6H), 4.23 (t, 2H), 3.65-3.54 (m, 4H), 3.35 (m, 1H), 2.05-1.87 (m, 2H), 1.67-1.51 (m, 9H), 0.90 (s, 3H), 0.87 (s, 6H). ESI-MS：（m/z，%）= 448 [M+H]⁺。

Example 8: determination of the Effect of Boragine derivatives on the model of PC12 nerve cell injury caused by oxygen deprivation (OGD)

Ischemic stroke is a clinical syndrome of focal nervous system symptoms and signs caused by the disorder of oxygen supply and energy metabolism of brain tissues due to the stenosis or blockage of cerebral vessels. The PC12 cell is rat pheochromocytoma cell, has the characteristics of a plurality of nerve cells, is often used for research instead of the nerve cells, and is widely used for research of in vitro ischemic injury. The Oxygen-glucose depletion (OGD) model can better simulate the damage of cerebral ischemia to nerve cells, and provides a simple and easy in-vitro model for researching the neuroprotective effect of a medicament.

Grouping experiments: a blank control group, a model group, a positive drug group (Baicalein) 10 mu mol, 3 dosage groups (10, 20 and 40 mu mol) of leonurine and 3 dosage groups (10, 20 and 40 mu mol) of test compounds;

sample treatment: dissolving the sample by DMSO, and storing at low temperature;

when the drugs of the different dosage groups are added into a 96-well plate, the drugs need to be diluted 1000 times to obtain a diluent containing the drugs to be screened.

Materials: DMEM sugar free medium, high glucose DMEM medium containing 10% FBS was purchased from Gibco; PC12 nerve cells were purchased from biochemical cells in shanghai, a chinese academy of sciences.

The experimental method comprises the following steps: collecting recovered PC12 cells at 2 × 10⁴Adding each cell/well into 96-well plate, adding 50 μ L of high-sugar DEME culture medium containing 10% FBS into each well, incubating overnight, replacing with new high-sugar DEME culture medium containing 10% FBS, adding 20 μ L of diluent containing drug to be screened, reacting for 24 hr, replacing with 50 μ L of sugar-free DEME culture medium, placing in anoxic incubator (5% CO)₂，1%O₂) Medium 2h, then replaced with 50. mu.L of high sugar DEME medium containing 10% FBS, while adding 20. mu.L of diluent containing the drug to be screened, and placed in a common cell incubator (95% O)₂，5% CO₂) Cell viability was measured 24h later using MTT (final concentration should be 0.5mg/ml when added to 96-well plates). The results of the experiment are shown in table 1.

TABLE 1 detection results of the survival rate of nerve cells

As can be seen from table 1: in the model of oxygen sugar deprivation induced PC12 nerve cell injury, the compounds B1 and B2 have significant difference compared with the OGD injury group, which indicates that the compound has a certain neuroprotective effect.

Example 9: determination of drug effect evaluation of leonurine borneol derivative on rat middle artery occlusion model

Grouping experiments: model group, positive drug group (A) edaravone (20 mg/kg), B1 (20 mg/kg), B2 (20 mg/kg) 8 rats per group.

The experimental method comprises the following steps: SD male rats weighing 250-. 2, 3, 5-triphenyltetrazolium chloride (TTC) staining to determine cerebral infarction area; longa test tests neurobehavioral scores.

The experimental results are as follows: dead rats and failed molding rats were removed after 24h, and the number of rats for statistics was 8 per group.

TABLE 2 cerebral infarct size and neuroethological scores

The results show that: the compounds B1 and B2 have the effect of improving the cerebral infarction area and neurobehavioral at the concentration of 20 mg/kg.

The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions.