A dual amino acid-genipin derivative, its preparation method and application

Abstract

The present invention discloses a bis - amino acid - genipin derivative, its preparation method and application; aiming to provide a bis - amino acid - genipin derivative with neuroprotective activity; the hemiacetal at the C - 1 position of genipin is oxidized and aminated to introduce the first amino acid fragment, and the second amino acid is introduced by esterification at the C - 10 position to obtain a series of brand - new genipin derivatives, which show good neuroprotective activity in the OGD / R - induced HT22 nerve cell injury model and can be used for preparing neuroprotective drugs; the general structural formula of the bis - amino acid - genipin derivative is as follows; it relates to the fields of pharmaceutical technology and medicinal chemistry.

Description

Technical Field

[0001] The present invention relates to the fields of pharmaceutical technology and medicinal chemistry, and particularly relates to a bis - amino acid - genipin derivative. The present invention also relates to a preparation method and an application of the bis - amino acid - genipin derivative. Background Art

[0002] Stroke, commonly known as "apoplexy", is a neurological disease, which is divided into ischemic stroke and hemorrhagic stroke. Most of them are ischemic stroke, with a very high disability rate, fatality rate and recurrence rate. With the acceleration of population aging, the incidence of stroke in China has been increasing year by year. The nerve injury mechanism after stroke is complex, mainly including ischemia - reperfusion injury, oxidative stress and immune - inflammatory injury. Tissue plasminogen activator (Rt - PA), as a thrombolytic agent, was approved by the FDA for the treatment of stroke more than 20 years ago and is currently widely used worldwide. However, its clinical use has side effects such as a narrow treatment time window, possible intracranial hemorrhage and neurotoxicity. Edaravone was approved in Japan in 2001 for the treatment of acute ischemic stroke and is a free - radical scavenger. Free radicals are reactive oxygen molecules produced during cell metabolism, which can damage cells. Edaravone can neutralize these free radicals, reduce oxidative stress, thereby protecting nerve cells from further damage, but it will damage renal function.

[0003] Ischemia - reperfusion injury (IR) is an important cause of death in ischemic stroke. In the hypoxic brain, the cessation of oxygen and glucose supply will lead to rapid depolarization of nerve cells, a large release of neurotransmitters, resulting in nerve cell damage and death. At present, the occluded artery can be recanalized by thrombolysis or thrombectomy. However, rapid restoration of blood flow in the ischemic area may further aggravate nerve cell and brain tissue damage. Finding effective neuroprotective drugs has important value and broad application prospects for the treatment of ischemia - reperfusion injury and stroke.

[0004] HT22 is a mouse hippocampal neuronal cell line, which is commonly used in neuroscience research. It is derived from neuronal cells in the mouse hippocampal region, has relatively stable characteristics, and is easy to culture and maintain under laboratory conditions. The HT22 cell line is widely used because of its research value in oxidative stress, neuroprotection and neurodegenerative diseases. In addition, neurons in the hippocampal region of the brain are vulnerable sites in cerebral ischemia - reperfusion, and are commonly used research objects in the study of cerebral ischemia - reperfusion injury. Therefore, the HT22 cell line is often used to explore how different compounds protect neurons from oxygen - glucose deprivation injury of cells and its mechanism of action.

[0005] Oxygen-Glucose Deprivation / Reperfusion (OGD / R) injury of cells is an important in vitro model that can simulate the process of ischemic reperfusion injury in HT22 neuronal cells. In this model, neuronal cells first experience a period of anaerobic and sugar-free environment, leading to energy metabolism disorders and impaired mitochondrial function, thereby generating a large amount of reactive oxygen species (ROS). Subsequently, when oxygen and glucose are re-supplied, ROS further accumulates, exacerbating oxidative stress and ultimately resulting in neuronal cell death. By measuring the change of lactate dehydrogenase (LDH), the integrity of the cell membrane and the degree of cell damage can be evaluated. This model is widely used to study the pathological mechanism of ischemic brain injury and to evaluate the efficacy of neuroprotective drugs.

[0006] In recent years, more and more studies have proven that amino acids have a variety of physiological activities and functions. For example, glycine has anti-inflammatory, immunomodulatory, and cell activity-protecting effects. It can prevent ischemia / reperfusion injury in various tissues and organs such as the liver, kidney, heart, intestine, and skeletal muscle, and reduce liver and kidney injuries caused by liver and kidney toxins and drugs. Clinical experiments have shown that the treatment with glycine has a significant improvement effect on ischemic stroke and can reduce the 30-day mortality rate of ischemic stroke patients. The aromatic amino acid L-phenylalanine (L-Phe) has a selective and significant inhibitory effect on the ionotropic glutamate receptors of excitatory synapses in rat or mouse hippocampal and cerebral cortical neuron cultures, and can safely and effectively protect the brain in the case of overactivation of glutamate receptors. At the same time, the brain contains amino acid transporters (large neutral amino acid transporter 1, LAT1), and drugs outside the blood-brain barrier (BBB) can enter the brain through transporter-mediated means to play a role. The combination of endogenous transporter substrates such as amino acids and active drug molecules can greatly increase the probability of compounds penetrating the blood-brain barrier.

[0007] Genipin is the aglycone of Geniposide and can be obtained by hydrolyzing Geniposide with β-glucosidase. It belongs to iridoid compounds. Genipin has a wide range of biological activities, such as neuroprotective effects, anti-cancer, hypoglycemic, antiviral, and anti-anxiety effects. Genipin can also be used as a new type of natural cross-linking agent and can cross-link with proteins, gelatin, chitosan, etc. to prepare biomaterials. However, the hemiacetal structure at the 1-position of Genipin is unstable, which affects its drug development and application. Currently, the research on developing new neuroprotective drugs by effectively combining amino acids with Genipin is still very limited. Summary of the Invention

[0008] One of the purposes of the present invention is to provide a dual amino acid-Genipin derivative with neuroprotective activity.

[0009] The second object of the present invention is to provide a preparation method of a bis - amino acid - genipin derivative.

[0010] The third object of the present invention is to provide the application of the bis - amino acid - genipin derivative in the preparation of neuroprotective drugs.

[0011] To this end, the first technical solution provided by the present invention is a bis - amino acid - genipin derivative, having the general structural formula of Formula 1:

[0012]

[0013] Formula 1

[0014] Wherein: R 1 is one of hydrogen, methyl, and benzyl; R 2 is one of hydrogen, methyl, benzyl, isopropyl, 2 - methylpropyl, 2 - (methylthio)ethyl, 2 - methoxybenzyl, (benzyloxy) group, (benzylthio) group, 1 - (benzyloxy)ethyl, indole - 3 - methyl; R 3 is one of hydrogen, tert - butyloxycarbonyl.

[0015] The second technical solution provided by the present invention is the preparation method of the above - mentioned bis - amino acid - genipin derivative, which successively includes the following steps:

[0016] Using genipin as the starting material, through tert - butyldimethylchlorosilane etherification reaction to obtain Intermediate 1, Intermediate 1 is oxidized to obtain Intermediate 2 through an oxidation reaction, Intermediate 2 and amino acid tert - butyl ester hydrochloride are subjected to an amination reaction to obtain Intermediate 3, and Intermediate 3 and an amino acid compound, 1 - ethyl - (3 - dimethylaminopropyl)carbodiimide hydrochloride are subjected to an esterification reaction to generate bis - amino acid - genipin derivative 1;

[0017] The synthetic route and its products are as follows:

[0018] .

[0019] Furthermore, in the above - mentioned preparation method of the bis - amino acid - genipin derivative, the oxidation reaction is Dess - Martin periodinane oxidation reaction.

[0020] Furthermore, in the above - mentioned preparation method of the bis - amino acid - genipin derivative, the amino acid tert - butyl ester hydrochloride is one or any combination of glycine tert - butyl ester hydrochloride, alanine tert - butyl ester hydrochloride, and phenylalanine tert - butyl ester hydrochloride.

[0021] Further, in the above preparation method of the bis - amino acid - genipin derivative, the amino acid compound is one or any combination of N - (tert - butoxycarbonyl) - L - tryptophan, N - (tert - butoxycarbonyl) - L - methionine, N - (tert - butoxycarbonyl) - O - benzyl - L - threonine, N - (tert - butoxycarbonyl) - L - isoleucine, N - (tert - butoxycarbonyl) - D - alanine, N - (tert - butoxycarbonyl) - O - benzyl - L - serine, N - (tert - butoxycarbonyl) - S - benzyl - L - cysteine, N - (tert - butoxycarbonyl) - L - valine, N - (tert - butoxycarbonyl) - L - phenylalanine, N - (tert - butoxycarbonyl) glycine, N - tert - butoxycarbonyl - 4 - methoxy - L - phenylalanine.

[0022] Further, the above preparation method of the bis - amino acid - genipin derivative further includes deprotecting the amino group of the bis - amino acid - genipin derivative 1 with trifluoroacetic acid to obtain the bis - amino acid - genipin derivative 2;

[0023] The synthetic route and its products are as follows:

[0024] 。

[0025] The last technical solution of the present invention is the application of the above - mentioned bis - amino acid - genipin derivative in the preparation of neuroprotective drugs.

[0026] Compared with the prior art, the present invention has carried out multi - site modification on genipin, introducing different amino acid combinations into the natural product skeleton, including oxidizing the hemi - acetal at the C - 1 position of genipin, aminating to introduce the first amino acid fragment, and esterifying at the C - 10 position to introduce the second amino acid to obtain a series of novel genipin derivatives, which show good neuroprotective activity in the OGD / R - induced HT22 nerve cell injury model, such as Figure 1, OGD / R induced damage to HT22 neurons, reducing their survival rate to 58%. The cell survival rates of the positive control drug Eda at 1 and 10 μM were 72% and 76% respectively, and those of the parent compound genipin (1) at 1 and 10 μM were 68% and 71% respectively. For the compounds 7a - 7k and 10a - 10k derived from compound 4, at a concentration of 1 μM, the neuroprotective activities of 9 compounds were significantly improved. At a concentration of 10 μM, the neuroprotective activities of 7 compounds were significantly improved. Among them, the neuroprotective activity of compound 10i at 1 and 10 μM was better than that of the positive control drug edaravone (Eda). For the compounds 8a - 8k and 11a - 11k derived from compound 5, at a concentration of 1 μM, the neuroprotective activities of 10 compounds were significantly improved. At a concentration of 10 μM, the neuroprotective activities of 7 compounds were significantly improved. For the compounds 9a - 9k and 12a - 12k derived from compound 6, at a concentration of 1 μM, the neuroprotective activities of 10 compounds were significantly improved. At a concentration of 10 μM, the neuroprotective activities of 7 compounds were significantly improved. Among them, the survival rate of compound 9a at a concentration of 10 μM reached 85%, which was significantly better than that of the positive control drug Eda (72%). Further studies on compound 9a confirmed that this type of derivative could effectively restore the morphology of damaged neurons induced by OGD / R and reduce the levels of reactive oxygen species and lactate dehydrogenase. Description of the Drawings

[0027] Figure 1 Figure showing the comparison of the protective activities of the bis - amino acid - genipin derivatives 7a - 7k and 10a - 10k against OGD / R - induced damage to HT - 22 cells.

[0028] Figure 2 Figure showing the comparison of the protective activities of the bis - amino acid - genipin derivatives 8a - 8k and 11a - 11k against OGD / R - induced damage to HT - 22 cells.

[0029] Figure 3 Figure showing the comparison of the protective activities of the bis - amino acid - genipin derivatives 9a - 9k and 12a - 12k against OGD / R - induced damage to HT - 22 cells.

[0030] Figure 4 Figure showing the screening of the optimal concentration of the bis - amino acid - genipin derivatives for the protective activity against OGD / R - induced damage to HT - 22 cells.

[0031] Figure 5 Figure showing the changes in lactate dehydrogenase content and morphological changes of the bis - amino acid - genipin derivatives against OGD / R - induced damage to HT - 22 cells.

[0032] Figure 6Figure showing the change in the content of reactive oxygen species in HT-22 cells damaged by OGD / R induced by a double amino acid-genipin derivative. Detailed implementation mode

[0033] The present invention will be further explained below in conjunction with examples and drawings, but the examples do not limit the present invention in any form. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the technical field. Unless otherwise specified, the reagents and materials used in the present invention are all commercially available.

[0034] Example 1 Synthesis of Compounds 7a-7k

[0035] As shown in Synthesis Route 1, starting from genipin, reacting with tert-butyldimethylchlorosilane in N,N-dimethylformamide solution to obtain Compound 2, dissolving Compound 2 in dichloromethane and reacting with Dess-Martin periodinane to obtain Compound 3, dissolving Compound 3 in N,N-dimethylformamide and reacting with amino acid tert-butyl ester hydrochloride compounds to obtain Compound 4 or 5 or 6, and then reacting the C-10 position of Compound 4 or 5 or 6 with the corresponding amino acid compound under the conditions of 4-dimethoxypyridine, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and dichloromethane solution to obtain one of Compounds 7a-7k, 8a-8k, 9a-9k.

[0036] The synthesis route is as follows:

[0037]

[0038] Synthesis Route 1

[0039] Reaction conditions and reagents in Synthesis Route 1: (a) tert-butyldimethylchlorosilane, N,N-dimethylformamide, room temperature; (b) Dess-Martin periodinane, in dichloromethane, room temperature. (c) Amino acid tert-butyl ester hydrochloride compounds, in N,N-dimethylformamide, heated at 110 °C. (d) Amino acid compounds, 4-dimethoxypyridine, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, dichloromethane, room temperature.

[0040] The specific steps of each compound are as follows: Reaction conditions and reagents in Synthesis Route 1: (a) tert-butyldimethylchlorosilane, N,N-dimethylformamide, room temperature; (b) Dess-Martin periodinane, in dichloromethane, room temperature. (c) Amino acid tert-butyl ester hydrochloride compounds, in N,N-dimethylformamide, heated at 110 °C. (d) Amino acid compounds, 4-dimethoxypyridine, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, dichloromethane, room temperature.

[0041] The specific steps of each compound are as follows:

[0042] (1) Synthesis of Compound 2

[0043] Dissolve 0.88 mmol of genipin (Compound 1), 1.056 mmol of tert-butyldimethylchlorosilane in 25.8 mmol of N , N N,N-dimethylformamide, stir at room temperature for 1 h; add ethyl acetate and saturated brine to the reaction solution for extraction, collect the organic layer, dry at room temperature and then concentrate, and use column chromatography to separate and purify the concentrate to obtain Compound 2;

[0044] (2) Synthesis of Compound 3

[0045] Dissolve 0.34 mmol of Compound 2 and 0.408 mmol of Dess-Martin periodinane in dichloromethane, react at room temperature for 3 h, then add ethyl acetate and saturated brine for extraction, collect the organic layer, dry at room temperature and then concentrate, and use column chromatography to separate and purify the concentrate to obtain Compound 3;

[0046] (3) Synthesis of Compound 4

[0047] Dissolve 0.34 mmol of Compound 3 and 1.02 mmol of tert-butyl glycinate hydrochloride in 25.8 mmol of N,N-dimethylformamide, heat and stir at 110 °C, react for 2 h, then add ethyl acetate and saturated brine (volume ratio 1:1) for extraction, collect the organic layer, dry at room temperature and then concentrate, and use column chromatography to separate and purify the concentrate to obtain Compound 4;

[0048] (4) Synthesis of Compounds 7a - 7k

[0049] Dissolve Compound 4 (100 mg, 0.34 mmol), 4-dimethoxypyridine (49 mg, 0.40 mmol), 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (193 mg, 1.01 mmol) and carboxylic acid compound (0.50 mmol) in dichloromethane, react at room temperature for 2 h, then add ethyl acetate and saturated brine (volume ratio 1:1) for extraction to obtain the organic layer, dry with anhydrous sodium sulfate at room temperature for 12 h and then concentrate, and use column chromatography to separate and purify the concentrate to obtain one of the pure products 7a - 7k respectively;

[0050] Among them: the carboxylic acid compounds used for the synthesis of 7a - 7k are as follows:

[0051] Synthesis 7a uses N-(tert-butoxycarbonyl)glycine; synthesis 7b uses N-(tert-butoxycarbonyl)-D-alanine; synthesis 7c uses N-(tert-butoxycarbonyl)-L-valine; synthesis 7d uses N-(tert-butoxycarbonyl)-L-isoleucine; synthesis 7e uses N-(tert-butoxycarbonyl)-L-methionine; synthesis 7f uses N-(tert-butoxycarbonyl)-L-phenylalanine; synthesis 7g uses N-tert-butoxycarbonyl-4-methoxy-L-phenylalanine; synthesis 7h uses N-(tert-butoxycarbonyl)-O-benzyl-L-serine; synthesis 7i uses N-(tert-butoxycarbonyl)-S-benzyl-L-cysteine; synthesis 7j uses N-(tert-butoxycarbonyl)-O-benzyl-L-threonine; synthesis 7k uses N-(tert-butoxycarbonyl)-L-tryptophan.

[0052] The structural formulas of compounds 7a - 7k are shown in Table 1; the appearance and NMR spectral data are as follows:

[0053] Compound 7a: colorless oil (50%) 1 H NMR (400 MHz, CDCl 3 ) δ 7.14 (s, 1H, H-3), 5.90 (s, 1H, H-7), 5.30 (s, 1H, -NH), 5.02 (s, 2H, H-10), 4.15 (d, J = 3.5Hz, 2H, -N-CH 2 ), 3.94 (d, J = 5.2 Hz, 2H, -CH 2 -NHBoc), 3.76 (s, 3H, -COOCH 3 ), 3.68 – 3.66 (m, 1H, H-9), 3.59 (m, 1H, H-5), 2.95 – 2.89 (m, 1H, H-6), 2.32 – 2.25 (m, 1H, H-6), 1.46 (s, 9H, -COOC(CH 3 ) 3 ), 1.45 (s, 9H, Boc). 13 C NMR (100MHz, CDCl 3) δ 170.04, 168.99, 166.95, 166.79, 155.69, 137.84, 136.66, 130.57,110.57, 82.84, 79.99, 63.47, 51.66, 49.25, 48.41, 42.48, 40.00, 37.12, 28.32,28.32, 28.32, 28.04, 28.04, 28.04. HRMS (ESI, m / z) calcd for C 24 H 34 N 2 O 9 Na,517.2162, [M+Na] + ; found, 517.2158。

[0054] Compound 7b: colorless oil (50%), 1 H NMR (400 MHz, CDCl 3 ) δ 7.14 (s, 1H, H-3),5.88 (s, 1H, H-7), 5.05 (s, 1H, -NH), 5.00 (s, 2H, H-10), 4.33 (d, J = 7.0Hz, 1H, -CH-COOCH 2 ), 4.15 (d, J = 3.1 Hz, 2H, -N-CH 2 ), 3.76 (s, 3H, -COOCH 3 ),3.68 – 3.65 (m, 1H, H-9), 3.63 – 3.52 (m, 1H, H-5), 2.95 – 2.89 (m, 1H, H-6),2.33 – 2.23 (m, 1H, H-6), 1.46 (s, 9H, -COOC(CH 3 ) 3 ), 1.44 (s, 9H, Boc), 1.40(d, J = 7.2 Hz, 3H, -CH-CH 3 ). 13 C NMR (100 MHz, CDCl 3) δ 173.00, 168.93,166.95, 166.80, 155.08, 137.83, 136.80, 130.08, 110.58, 82.81, 79.80, 63.48,55.74, 51.65, 49.25, 48.45, 40.06, 37.08, 28.34, 28.34, 28.34, 28.03, 28.03,28.03, 18.82. HRMS (ESI, m / z) calcd for C 25 H 36 N 2 O 9 Na, 531.2319, [M+Na] + ; found,531.2315。

[0055] Compound 7c: colorless oil (50%), 1 H NMR (400 MHz, CDCl 3 ) δ 7.15 (s, 1H, H-3),5.90 (s, 1H, H-7), 5.05 (d, J = 8.0 Hz, 1H, -NH), 5.01 - 4.94 (m, 2H, H-10),4.29 – 4.19 (m, 1H, -CH-COOCH 2 ), 4.18 – 4.08 (m, 2H, -N-CH 2 ), 3.76 (s, 3H, -COOCH 3 ), 3.68 – 3.65 (m, 1H, H-9), 3.61 – 3.54 (m, 1H, H-5), 2.96 – 2.90 (m,1H, H-6), 2.35 – 2.23 (m, 1H, H-6), 2.15 (dd, J = 11.9, 6.5 Hz, 1H, -CH-(CH 3 ) 2 ), 1.45 (s, 9H, -COOC(CH 3 ) 3 ), 1.44 (s, 9H, Boc), 0.97 (d, J = 6.9 Hz,3H, -CH-CH 3 ), 0.89 (d, J = 6.9 Hz, 3H, -CH-CH 3 ). 13 C NMR (100 MHz, CDCl3 ) δ172.09, 168.94, 166.95, 166.81, 155.70, 137.85, 136.82, 130.45, 110.56, 82.79, 79.72, 63.34, 58.59, 51.65, 49.28, 48.35, 40.06, 37.05, 31.39, 28.32, 28.32, 28.32, 28.02, 28.02, 28.02, 19.04, 17.55。

[0056] Compound 7d: colorless oil (43%), 1 H NMR (400 MHz, CDCl 3 ) δ 7.15 (s, 1H, H-3), 5.89 (s, 1H, H-7), 4.99 (s, 2H, H-10), 4.92 (d, J = 8.7 Hz, 1H, -NH), 4.33 (d, J = 5.6 Hz, 1H, -CH-COOCH 2 ), 4.22 – 4.06 (m, 2H, -N-CH 2 ), 3.76 (s, 3H, -COOCH 3 ), 3.69 – 3.67 (m, 1H, H-9), 3.61 – 3.55 (m, 1H, H-5), 2.95 – 2.89 (m, 1H, H-6), 2.38 – 2.21 (m, 1H, H-6), 1.72 – 1.57 (m, 2H, -CH 2 -CH-(CH 3 ) 2 ), 1.55 – 1.47 (m, 1H, -CH-(CH 3 ) 2 ), 1.46 (s, 9H, -COOC(CH 3 ) 3 ), 1.43 (s, 9H, Boc), 0.95 (s, 3H, -CH-CH 3 ), 0.93 (d, J = 1.3 Hz, 3H, -CH-CH 3 ). 13 C NMR (100 MHz, CDCl 3) δ173.12, 168.95, 166.95, 166.80, 155.42, 137.84, 136.82, 130.06, 110.56,82.76, 79.77, 63.41, 52.17, 51.63, 49.24, 48.37, 41.86, 40.03, 37.08, 28.31,28.31, 28.31, 28.02, 28.02, 28.02, 24.79, 22.83, 21.96。

[0057] Compound 7e: colorless oil (88%), 1 H NMR (400 MHz, CDCl 3 ) δ 7.15 (s, 1H, H-3),5.90 (s, 1H, H-7), 5.16 (d, J = 7.7 Hz, 1H, -NH), 5.01 (s, 2H, H-10), 4.44(d, J = 5.0 Hz, 1H, -CH-COOCH 2 ), 4.15 (s, 2H, -N-CH 2 ), 3.76 (s, 3H, -COOCH 3 ),3.69 – 3.66 (m, 1H, H-9), 3.62 - 3.55 (m, 1H, H-5), 2.96 – 2.90 (m, 1H, H-6),2.55 (t, J = 7.6 Hz, 2H, -S-CH 2 ), 2.34 – 2.23 (m, 1H, H-6), 2.17 – 2.12 (m,1H, -CH-CH 2a ), 2.09 (s, 3H, -S-CH 3 ), 2.01 – 1.88 (m, 1H, -CH-CH 2b ), 1.46 (s,9H, -COOC(CH 3 ) 3 ), 1.44 (s, 9H, Boc). 13 C NMR (100 MHz, CDCl 3) δ 171.96, 168.88, 166.94, 166.79, 155.35, 137.83, 136.62, 130.53, 110.57, 82.81, 80.00, 63.66, 52.86, 51.66, 49.25, 48.44, 40.09, 37.04, 32.32, 29.94, 28.31, 28.31, 28.31, 28.03, 28.03, 28.03, 15.49. HRMS (ESI, m / z) calcd for C 27 H 40 N 2 O 9 SNa, 591.2353, [M+Na] + ; found, 591.2357。

[0058] Compound 7f: colorless oil (45%), 1 H NMR (400 MHz, CDCl 3 ) δ 7.30 – 7.27 (m, 1H, H-3), 7.25 – 7.08 (m, 5H, -Ph), 5.81 (s, 1H, H-7), 5.01 – 4.93 (m, 3H, overlap, H-10, -NHBoc), 4.60 (d, J = 7.4 Hz, 1H, -CH-NHBoc), 4.22 – 4.08 (m, 2H, -N-CH 2 ), 3.76 (s, 3H, -COOCH 3 ), 3.62 – 3.43 (m, 2H, overlap, H-9, H-5), 3.10 (d, J = 5.5 Hz, 2H, -CH 2 -Ph), 2.92 – 2.86 (m, 1H, H-6), 2.34 – 2.18 (m, 1H, H-6), 1.45 (s, 9H, -COOC(CH 3 ) 3 ), 1.41 (s, 9H, Boc). 13 C NMR (100 MHz, CDCl 3) δ 171.59, 169.00, 166.96, 166.82, 155.08, 137.86, 136.60, 136.06,130.71, 129.40, 129.40, 128.54, 128.54, 126.95, 110.51, 82.80, 79.88, 63.58,54.49, 51.66, 49.23, 48.15, 39.98, 38.49, 37.08, 28.31, 28.31, 28.31, 28.03,28.03, 28.03。

[0059] Compound 7g: colorless oil (88%), 1 H NMR (400 MHz, CDCl 3 ) δ 7.15 (s, 1H, H-3), 7.06 (d, J J = 8.6 Hz, 2H, Ar-H), 6.81 (d, J J = 8.6 Hz, 2H, Ar-H), 5.83 (s, 1H, H-7), 5.00 (d, J J = 6.8 Hz, 2H, H-10), 4.94 (d, J J = 13.4 Hz, 1H, -CH-COOCH 2 ), 4.56 (d, J J = 7.7 Hz, 1H, -NH), 4.15 (s, 2H, -N-CH 2 ), 3.77 (s, 3H, -COOCH 3 ), 3.76 (s, 3H, -OCH 3 ), 3.55 – 3.51 (m, 2H, overlap, H-9, H-5), 3.04 (d, J J = 5.8Hz, 2H, -CH 2 -Ph), 2.96 – 2.85 (m, 1H, H-6), 2.33 – 2.21 (m, 1H, H-6), 1.45(s, 9H, -COOC(CH 3 ) 3 ), 1.41 (s, 9H, Boc). 13 C NMR (100 MHz, CDCl 3) δ 171.66,169.00, 166.96, 166.81, 158.63, 155.11, 137.87, 136.66, 130.64, 130.40,130.40, 127.97, 113.95, 113.95, 110.49, 82.78, 79.84, 63.54, 55.21, 54.60,51.65, 49.26, 48.14, 39.96, 37.58, 37.11, 28.32, 28.32, 28.32, 28.03, 28.03,28.03。

[0060] Compound 7h: colorless oil (12%), 1 H NMR (400 MHz, CDCl 3 ) δ 7.35 – 7.27 (m, 4H,Ar-H), 7.26 – 7.23 (m, 1H, Ar-H), 7.12 (s, 1H, H-3), 5.84 (s, 1H, H-7), 5.41(d, J = 8.8 Hz, 1H, -O-CH 2 -CH), 5.13 – 4.97 (m, 2H, H-10), 4.51 (d, J = 5.4Hz, 2H, -CH 2 -Ph), 4.49 – 4.44 (m, 1H, -NH), 4.14 (s, 2H, -N-CH 2 ), 3.92 (dd, J = 9.4, 3.0 Hz, 1H, -O-CH 2a -CH), 3.75 (s, 3H, -COOCH 3 ), 3.70 (dd, J = 9.4, 3.0Hz, 1H, -O-CH 2b -CH), 3.60 – 3.58 (m, 1H, H-9), 3.55 – 3.46 (m, 1H, H-5), 2.88– 2.82 (m, 1H, H-6), 2.30 – 2.16 (m, 1H, H-6), 1.45 (s, 9H, -COOC(CH 3 ) 3 ), 1.44(s, 9H, Boc). 13 C NMR (100 MHz, CDCl3 ) δ 170.31, 168.96, 166.97, 166.81, 155.50, 139.82, 137.81, 136.72, 129.90, 128.41, 128.41, 127.79, 127.64, 127.64, 110.56, 82.79, 79.96, 73.36, 70.26, 63.71, 54.10, 51.63, 49.21, 48.40, 39.99, 37.13, 28.33, 28.33, 28.33, 28.03, 28.03, 28.03. HRMS (ESI, m / z) calcd for C 32 H 42 N 2 O 10 Na, 637.2737, [M+Na] + ; found, 637.2794。

[0061] Compound 7i: colorless oil (51%), 1 H NMR (400 MHz, CDCl 3 ) δ 7.33 (m, 1H, Ar-H), 7.24 (m, 1H, Ar-H), 7.15 (s, 1H, H-3), 5.88 (s, 1H, H-7), 5.30 (d, J = 7.9 Hz, 1H, -NH), 5.12 – 4.92 (m, 2H, H-10), 4.54 (d, J = 7.3 Hz, 1H, -CH-COOCH 2 ), 4.15 (s, 2H, -N-CH 2 ), 3.76 (s, 3H, -COOCH 3 ), 3.73 (s, 2H, -CH 2 -Ph), 3.61 (t, J = 8.5 Hz, 1H, H-9), 3.58 – 3.49 (m, 1H, H-5), 3.00 – 2.85 (m, 2H, -CH-CH 2 ), 2.94 – 2.86 (m, 1H, H-6), 2.41 – 2.16 (m, 1H, H-6), 1.45 (s, 18H, overlap, -COOC(CH 3 ) 3,Boc). 13 C NMR (100 MHz, CDCl 3 ) δ 171.74, 168.93, 166.95, 166.81, 155.19, 139.11, 137.85, 136.53, 130.52, 128.98, 128.98, 128.58, 128.58, 127.19, 110.54, 82.80, 80.15, 63.81, 53.21, 51.66, 49.23, 48.37, 40.04, 37.08, 36.63, 33.73, 28.33, 28.33, 28.33, 28.04, 28.04, 28.04. HRMS(ESI, m / z) calcd for C 32 H 42 N 2 O 9 SNa, 653.2509, [M+Na] + ; found, 653.2519。

[0062] Compound 7j: colorless oil (53%), 1 H NMR (400 MHz, CDCl 3 ) δ 7.34 – 7.28 (m, 1H, Ar-H), 7.27 (s, 1H, Ar-H), 7.25 (d, J J = 7.9 Hz, 1H, Ar-H), 7.12 (s, 1H, H-3), 5.84 (s, 1H, H-7), 5.31 (d, J J = 9.6 Hz, 1H, -NH), 5.05 – 4.93 (m, 2H, H-10), 4.54 (d, J J = 11.6 Hz, 1H, -O-CH), 4.47 – 4.31 (m, 2H, -O-CH 2 ), 4.21 – 4.15 (m, 1H, -CH-COOCH 2 ), 4.13 (s, 2H, -N-CH 2 ), 3.75 (s, 3H, -COOCH 3), 3.61 – 3.58(m, 1H, H-9), 3.53 – 3.46 (m, 1H, H-5), 2.90 – 2.77 (m, 1H, H-6), 2.31 – 2.17(m, 1H, H-6), 1.45 (s, 9H, -COOC(CH 3 ) 3 ), 1.44 (s, 9H, Boc), 1.26 (d, J = 6.3Hz, 3H, -O-CH-CH 3 ). 13 C NMR (100 MHz, CDCl 3 ) δ 170.78, 168.93, 166.96, 166.79,156.14, 137.97, 137.81, 136.74, 130.08, 128.33, 128.33, 127.66, 127.60,127.60, 110.53, 82.75, 79.81, 74.84, 70.98, 63.58, 58.27, 51.62, 49.22,48.39, 39.99, 37.07, 28.33, 28.33, 28.33, 28.02, 28.02, 28.02, 16.35。

[0063] Compound 7k: colorless oil (41%), 1 H NMR (400 MHz, CDCl 3 ) δ 8.69 (s, 1H, -NH inindole), 7.66 (d, J = 6.7 Hz, 1H, Ar-H), 7.32 (d, J = 7.4 Hz, 1H, Ar-H), 7.14(s, 1H, H-3), 7.11 – 7.08(m, 2H, Ar-H), 6.92 (d, J = 2.2 Hz, 1H, -CH inpyrrole ring), 5.70 (s, 1H, H-7), 5.19 – 5.09 (m, 2H, H-10), 4.69 (s, 1H, -NHBoc), 4.63 (d, J = 12.7 Hz, 1H, -CH-COOCH 2 ), 4.47 (d, J= 17.2 Hz, 1H, -N-CH 2a ), 3.86 (d, J = 17.3 Hz, 1H, -N-CH 2b ), 3.77 (s, 3H, -COOCH 3 ), 3.33 (d, J =10.5 Hz, 1H, -CH-CH 2a ), 3.19 – 2.97 (m, 2H, overlap, H-9, H-5), 2.75 – 2.69(m, 1H, H-6), 2.58 (d, J = 10.1 Hz, 1H, -CH-CH 2b ), 2.15 – 2.07 (m, 1H, H-6),1.51 (s, 9H, -COOC(CH 3 ) 3 ), 1.45 (s, 9H, Boc). HRMS (ESI, m / z) calcd forC 33 H 41 N 3 O 9 Na, 646.2741, [M+Na] + ; found, 646.2746。

[0064] Table 1 Structural formulas of 7a - 7k

[0065]

[0066] Example 2 Synthesis of compounds 8a - 8k

[0067] (1) Synthesis of compound 5

[0068] Dissolve 0.34 mmol of compound 3 prepared in Example 1 and 1.02 mmol of tert-butyl alaninate hydrochloride in 25.8 mmol of N,N-dimethylformamide, heat and stir at 110 °C. After reacting for 2 h, add ethyl acetate and saturated brine (volume ratio 1:1) for extraction, collect the organic layer, dry at room temperature and concentrate. Use column chromatography to separate and purify the concentrate to obtain compound 5;

[0069] (2) Synthesis of compounds 8a - 8k

[0070] Compound 5 (100 mg, 0.34 mmol), 4-dimethoxypyridine (49 mg, 0.41 mmol), 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (193 mg, 1.01 mmol), and the carboxylic acid compound (0.50 mmol) were dissolved in dichloromethane. After reacting at room temperature for 2 h, ethyl acetate and saturated brine (volume ratio 1:1) were added for extraction to obtain the organic layer, which was dried with anhydrous sodium sulfate at room temperature for 12 h and then concentrated. The concentrate was separated and purified by column chromatography to obtain one of the pure products 8a - 8k respectively;

[0071] Among them: the carboxylic acid compounds used for the synthesis of 8a - 8k are as follows:

[0072] N-(tert-butoxycarbonyl)glycine was used for the synthesis of 8a; N-(tert-butoxycarbonyl)-D-alanine was used for the synthesis of 8b; N-(tert-butoxycarbonyl)-L-valine was used for the synthesis of 8c; N-(tert-butoxycarbonyl)-L-isoleucine was used for the synthesis of 8d; N-(tert-butoxycarbonyl)-L-phenylalanine was used for the synthesis of 8f; N-(tert-butoxycarbonyl)-L-methionine was used for the synthesis of 8e; N-tert-butoxycarbonyl-4-methoxy-L-phenylalanine was used for the synthesis of 8g; N-(tert-butoxycarbonyl)-O-benzyl-L-serine was used for the synthesis of 8h; N-(tert-butoxycarbonyl)-S-benzyl-L-cysteine was used for the synthesis of 8i; N-(tert-butoxycarbonyl)-O-benzyl-L-threonine was used for the synthesis of 8j; N-(tert-butoxycarbonyl)-L-tryptophan was used for the synthesis of 8k.

[0073] The structural formulas of compounds 8a - 8k are shown in Table 2; the appearance and NMR spectral data are as follows:

[0074] Compound 8a: colorless oil (65%) 1 H NMR (400 MHz, CDCl 3 ) δ 7.27 (s, 1H, H-3), 5.89 (s, 1H, H-7), 5.01 (m, 3H, overlap, H-10, -NH), 4.99 – 4.93 (m, 1H, -N-CH), 3.95 (d, J = 5.4 Hz, 2H, -CH 2 -NHBoc), 3.76 (s, 3H, -COOCH 3), 3.68 – 3.65(m, 1H, H-9), 3.61 – 3.50 (m, 1H, H-5), 2.95 – 2.89 (m, 1H, H-6), 2.28 – 2.14(m, 1H, H-6), 1.47 (d, J J = 7.4 Hz, 3H, -N-CH-CH 3 ), 1.45 (s, 9H, -COOC(CH 3 ) 3 ),1.44 (s, 9H, Boc). 13 13C NMR (100 MHz, CDCl 3 ) δ 170.04, 169.80, 168.70, 166.87,155.68, 136.85, 134.96, 130.45, 110.65, 82.44, 79.99, 63.45, 53.00, 51.64,48.81, 42.46, 8.09, 36.47, 28.32, 28.32, 28.32, 27.93, 27.93, 27.93, 15.94.HRMS (ESI, m / z) calcd for C 25 H 36 N 2 O 9 Na, 531.2319, [M+Na] + ; found, 531.2292。

[0075] Compound 8b: colorless oil (50%), 1 1H NMR (400 MHz, CDCl 3 ) δ 7.27 (s, 1H, H-3),5.87 (s, 1H, H-7), 5.07 (d, J J = 5.5 Hz, 1H, -NH), 5.00 (s, 2H, H-10), 4.99 –4.93 (m, 1H, -N-CH), 4.41 – 4.28 (m, 1H, -CH-COOCH 2 ), 3.76 (s, 3H, -COOCH 3), 3.68 – 3.65 (m, 1H, H-9), 3.60 - 3.53 (m, 1H, H-5), 2.95 – 2.90 (m, 1H, H-6), 2.30 – 2.15 (m, 1H, H-6), 1.47 (d, J J = 7.4 Hz, 3H, -N-CH-CH 3 ), 1.44 (s, 18H, overlap, -COOC(CH 3 ) 3, Boc), 1.40 (d, J J = 7.2 Hz, 3H, -CH-CH 3 ). 13 C NMR (100 MHz, CDCl 3 ) δ 172.97, 169.83, 168.66, 166.89, 155.11, 136.98, 134.94, 129.96, 110.68, 82.43, 79.81, 63.45, 52.99, 51.64, 49.26, 48.87, 40.15, 36.44, 28.33, 28.33, 28.33, 27.93, 27.93, 27.93, 18.79, 15.94. HRMS (ESI, m / z) calcd for C 26 H 38 N 2 O 9 K, 561.2214, [M+K] + ; found, 561.2180。

[0076] Compound 8c: colorless oil (51%), 1 H NMR (400 MHz, CDCl 3 ) δ 7.27 (s, 1H, H-3), 5.89 (s, 1H, H-7), 5.05 (d, J J = 8.4 Hz, 1H, -NH), 5.00 (s, 2H, H-10), 4.98 – 4.91 (m, 1H, -N-CH), 4.24 (dd, J J = 8.9, 4.6 Hz, 1H, -CH-COOCH 2 ), 3.76 (s, 3H, -COOCH 3), 3.68 – 3.65 (m, 1H, H-9), 3.61 – 3.48 (m, 1H, H-5), 2.96 – 2.89 (m,1H, H-6), 2.24 – 2.08 (m, 2H, overlap, H-6, -CH-(CH 3 ) 2 ), 1.47 (d, J J = 7.4 Hz,3H, -N-CH-CH 3 ), 1.44 (s, 18H, overlap, -COOC(CH 3 ) 3, Boc), 0.97 (d, J J = 6.8 Hz,3H, -CH-CH 3 ), 0.89 (d, J J = 6.9 Hz, 3H, -CH-CH 3 ). 13 13C NMR (100 MHz, CDCl 3 ) δ172.09, 169.84, 168.66, 166.89, 155.69, 137.00, 134.93, 130.31, 110.65,82.40, 79.72, 63.30, 62.71, 58.59, 53.01, 51.63, 48.76, 40.14, 36.41, 28.32,28.32, 28.32, 27.92, 27.92, 27.92, 19.04, 17.54, 15.90. HRMS (ESI, m / z) calcdfor C 28 H 42 N 2 O 9 Na, 573.2788, [M+Na] + ; found, 573.2769。

[0077] Compound 8d: colorless oil (50%), 1 1H NMR (400 MHz, CDCl 3 ) δ 7.27 (s, 1H, H-3),5.88 (s, 1H, H-7), 5.06 – 4.94 (m, 3H, overlap, H-10, -NH), 4.91 (d, J J = 8.6Hz, 1H, -N-CH), 4.33 (dd,J = 14.0, 8.6 Hz, 1H, -CH-COOCH 2 ), 3.76 (s, 3H, -COOCH 3 ), 3.67 – 3.64 (m, 1H, H-9), 3.59 – 3.52 (m, 1H, H-5), 2.96 – 2.89 (m,1H, H-6), 2.25 – 2.16 (m, 1H, H-6), 1.77 – 1.70 (m, 1H, -CH-CH 2 ), 1.66 – 1.50(m, 2H, -CH-CH 2 ), 1.47 (d, J = 7.4 Hz, 3H, -N-CH-CH 3 ), 1.44 (s, 9H, -COOC(CH 3 ) 3 ), 1.44 (s, 9H, Boc), 0.94 (dd, J = 6.5, 1.5 Hz, 6H, -CH-(CH 3 ) 2 ). 13 C NMR(100 MHz, CDCl 3 ) δ 173.15, 169.84, 168.68, 166.90, 155.42, 137.00, 134.95,129.95, 110.68, 82.41, 79.79, 63.41, 52.99, 52.17, 51.63, 48.79, 41.88,40.14, 36.45, 28.32, 28.32, 28.32, 27.93, 27.93, 27.93, 24.80, 22.84, 21.97,15.94. HRMS (ESI, m / z) calcd for C 29 H 44 N 2 O 9 Na, 587.2945, [M+Na] + ; found,587.2938。

[0078] Compound 8e: colorless oil (88%), 1 H NMR (400 MHz, CDCl 3) δ 7.27 (s, 1H, H-3), 5.89 (s, 1H, H-7), 5.15 (d, J J = 7.6 Hz, 1H, -NH), 5.00 (d, J J = 6.5 Hz, 2H, H-10), 4.98 – 4.92 (m, 1H, -N-CH), 4.44 (d, J J = 5.0 Hz, 1H, -CH-COOCH 2 ), 3.76(s, 3H, -COOCH 3 ), 3.69 – 3.66 (m, 1H, H-9), 3.60 – 3.53 (m, 1H, H-5), 3.16 – 2.89 (m, 1H, H-6), 2.55 (t, J J = 7.6 Hz, 2H, -S-CH 2 ), 2.33 – 2.11 (m, 2H, -CH-CH 2 ), 2.09 (s, 3H, -S-CH 3 ), 2.03 – 1.86 (m, 1H, H-6), 1.47 (d, J J = 7.4 Hz, 3H, -N-CH-CH 3 ), 1.44 (s, 18H, overlap, -COOC(CH 3 ) 3 , Boc). 13 C NMR (100 MHz, CDCl 3 ) δ 171.98, 169.79, 168.60, 166.87, 155.33, 136.81, 134.97, 130.38, 110.67, 82.43, 80.00, 63.64, 53.06, 52.86, 51.65, 48.85, 40.19, 36.40, 32.32, 29.94, 28.31, 28.31, 28.31, 27.93, 27.93, 27.93, 15.95, 15.49。

[0079] Compound 8f: colorless oil (45%), 1 1H NMR (400 MHz, CDCl 3 ) δ 7.29 – 7.27 (m, 2H, overlap, Ar-H, H-3), 7.23 (dd,J = 14.4, 7.4 Hz, 2H, Ar-H), 7.15 (d, J = 6.8Hz, 2H, Ar-H), 5.80 (s, 1H, H-7), 5.01 (d, J = 8.0 Hz, 1H, -NH), 4.97 (d, J =7.2 Hz, 2H, H-10), 4.94 (d, J = 4.3 Hz, 1H, -N-CH), 4.60 (dd, J = 13.5, 6.1Hz, 1H, -CH-COOCH 2 ), 3.77 (s, 3H, -COOCH 3 ), 3.57 – 3.41 (m, 2H, overlap, H-9,H-5), 3.09 (d, J = 5.3 Hz, 2H, -CH 2 -Ph), 2.98 – 2.81 (m, 1H, H-6), 2.26 –2.09 (m, 1H, H-6), 1.47 (d, J = 7.4 Hz, 3H, -N-CH-CH 3 ), 1.44 (s, 9H, -COOC(CH 3 ) 3 ), 1.41 (s, 9H, Boc). 13 C NMR (100 MHz, CDCl 3 ) δ 171.62, 169.84, 168.72,166.90, 155.09, 136.79, 136.04, 135.00, 130.60, 129.40, 129.40, 128.55,128.55, 126.96, 110.61, 82.42, 79.89, 63.56, 54.51, 53.02, 51.65, 48.54,40.08, 38.52, 36.43, 28.31, 28.31, 28.31, 27.93, 27.93, 27.93, 15.97. HRMS(ESI, m / z) calcd for C 32 H 42 N 2 O 9 Na, 621.2788, [M+Na]+ ; found, 621.2827。

[0080] Compound 8g: colorless oil (88%), 1 H NMR (400 MHz, CDCl 3 ) δ 7.27 (s, 1H, H-3), 7.06 (d, J J = 8.6 Hz, 2H, Ar-H), 6.82 (d, J J = 8.6 Hz, 2H, Ar-H), 5.81 (s, 1H, H-7), 4.97 (s, 3H, overlap, H-10, -NH), 4.94 (d, J J = 7.3 Hz, 1H, -N-CH), 4.56 (d, J J = 7.5 Hz, 1H, -CH-COOCH 2 ), 3.77 (s, 3H, -COOCH 3 ), 3.77 (s, 3H, -OCH 3 ), 3.59 – 3.46 (m, 2H, overlap, H-9, H-5), 3.04 (d, J J = 5.3 Hz, 2H, -CH 2 -Ph), 2.93 – 2.87 (m, 1H, H-6), 2.27 – 2.13 (m, 1H, H-6), 1.47 (d, J J = 7.4 Hz, 3H, -N-CH-CH 3 ), 1.44 (s, 9H, -COOC(CH 3 ) 3 ), 1.41 (s, 9H, Boc). 13 C NMR (100 MHz, CDCl 3) δ 171.66, 169.82, 168.72, 166.90, 158.66, 155.11, 136.82, 135.00, 130.50, 130.50, 130.40, 127.94, 113.96, 113.96, 110.64, 82.41, 79.88, 63.49, 55.21, 54.59, 53.09, 51.65, 48.65, 40.11, 37.55, 36.44, 28.32, 28.32, 28.32, 27.93, 27.93, 27.93, 15.94. HRMS (ESI, m / z) calcd for C 33 H 44 N 2 O 10 Na, 651.2894, [M+Na] + ; found, 651.2860. 651.2860。

[0081] Compound 8h: colorless oil (12%), 1 H NMR (400 MHz, CDCl 3 ) δ 7.37 – 7.27 (m, 4H, Ar-H), 7.27 – 7.22 (m, 2H, overlap, Ar-H, H-3), 5.83 (s, 1H, H-7), 5.42 (d, J = 8.7 Hz, 1H, -N-CH), 5.03 (s, 2H, H-10), 5.01 – 4.91 (m, 1H, -NH), 4.52 (t, J = 9.1 Hz, 2H, -CH 2 -Ph), 4.49 – 4.42 (m, 1H, -CH-COOCH 2 ), 3.92 (dd, J = 9.3, 2.9 Hz, 1H, -O-CH 2a -CH), 3.76 (s, 3H, -COOCH 3 ), 3.70 (dd, J = 9.3, 3.1 Hz, 1H, -O-CH 2b-CH), 3.61 – 3.58 (m, 1H, H-9), 3.54 – 3.49 (m, 1H, H-5), 2.89 – 2.83(m, 1H, H-6), 2.30 – 2.02 (m, 1H, H-6), 1.47 (d, J J = 7.4 Hz, 3H, -N-CH-CH 3 ),1.44 (s, 9H, -COOC(CH 3 ) 3 ), 1.43 (s, 9H, Boc). 13 C NMR (100 MHz, CDCl 3 ) δ170.30, 169.82, 168.67, 166.88, 155.49, 137.48, 136.85, 134.95, 129.75,128.42, 128.42, 127.81, 127.67, 127.67, 110.69, 82.40, 79.95, 73.37, 70.20,63.67, 54.09, 52.98, 51.62, 48.88, 40.12, 36.46, 28.33, 28.33, 28.33, 27.92,27.92, 27.92, 15.97. HRMS (ESI, m / z) calcd for C 33 H 44 N 2 O 10 Na, 651.2894, [M+Na] + ;found, 647.2922。

[0082] Compound 8i: colorless oil (51%), 1 H NMR (400 MHz, CDCl 3 ) δ 7.30 (d, J J = 4.4Hz, 4H, Ar-H), 7.27 (s, 1H, H-3), 7.25 -7.22 (m, 1H, Ar-H), 5.87 (s, 1H, H-7), 5.30 (d, J J = 7.9 Hz, 1H, -NH), 5.01 (s, 2H, H-10), 4.96 (t, J J = 7.4 Hz,1H, -N-CH), 4.54 (dd, J= 12.5, 5.4 Hz, 1H, -CH-COOCH 2 ), 3.77 (s, 3H, -COOCH 3 ), 3.73 (s, 2H, -CH 2 -Ph), 3.63 – 3.60 (m, 1H, H-9), 3.59 – 3.50 (m, 1H,H-5), 2.96 – 2.86 (m, 2H, -S-CH 2 -CH), 2.94 – 2.79 (m, 1H, H-6), 2.31 – 2.12(m, 1H, H-6), 1.47 (d, J = 7.6 Hz, 3H, -N-CH-CH 3 ), 1.45 (s, 9H, -COOC(CH 3 ) 3 ),1.44 (s, 9H, Boc). 13 C NMR (100 MHz, CDCl 3 ) δ 170.78, 169.80, 168.65, 166.88,155.19, 137.71, 136.72, 134.99, 130.38, 128.98, 128.98, 128.58, 128.58,127.20, 110.65, 82.41, 80.10, 63.78, 53.19, 53.01, 51.65, 48.79, 40.15,36.62, 36.43, 33.70, 28.33, 28.33, 28.33, 27.94, 27.94, 27.94,15.97. HRMS(ESI, m / z) calcd for C 33 H 44 N 2 O 9 SNa, 667.2665, [M+Na] + ; found, 667.2660。

[0083] Compound 8j: colorless oil (53%), 1 H NMR (400 MHz, CDCl 3 ) δ 7.33 – 7.29 (m, 4H,Ar-H), 7.24 (s, 2H, Ar-H, H-3), 5.83 (s, 1H, H-7), 5.31 (d, J= 9.6 Hz, 1H, -NH), 5.03 (d, J = 13.8 Hz, 1H, -N-CH), 4.94 (dd, J = 13.0, 5.4 Hz, 2H, H-10),4.54 (d, J = 11.7 Hz, 1H, -O-CH-CH 3 ), 4.43 – 4.29 (m, 2H, -O-CH 2 ), 4.20 – 4.08(m, 1H, -CH-NHBoc), 3.76 (s, 3H, -COOCH 3 ), 3.62 – 3.59 (m, 1H, H-9), 3.50 –3.45 (m, 1H, H-5), 2.87 – 2.81 (m, 1H, H-6), 2.20 – 2.08 (m, 1H, H-6), 1.46(d, J = 7.7 Hz, 3H, -N-CH-CH 3 ), 1.45 (s, 9H, -COOC(CH 3 ) 3 ), 1.43 (s, 9H, Boc),1.27 (s, 3H, -O-CH-CH 3 ). 13 C NMR (100 MHz, CDCl 3 ) δ 170.78, 169.82, 168.64,166.89, 156.14, 137.94, 136.88, 134.95, 129.95, 128.34, 128.34, 127.69,127.65, 127.65, 110.66, 82.38, 79.82, 74.78, 70.98, 63.55, 58.27, 53.02,51.61, 48.87, 40.11, 36.41, 28.33, 28.33, 28.33, 27.92, 27.92, 27.92, 16.35,15.94。

[0084] Compound 8k: colorless oil (8%), 1 H NMR (400 MHz, CDCl 3 ) δ 8.64 (s, 1H, -NH in indole), 7.65 (d, J= 7.3 Hz, 1H, Ar-H), 7.31 (d, J = 7.3 Hz, 1H, Ar-H), 7.27(s, 1H, H-3), 7.14 - 7.07 (m, 2H, Ar-H), 6.91 (d, J = 2.0 Hz, 1H, -CH in pyrrole ring), 5.70 (s, 1H, H-7), 5.24 - 5.04 (m, 3H, overlap, -N-CH, H-10),4.71 (d, J = 4.6 Hz, 1H, -NH), 4.63 (d, J = 12.7 Hz, 1H, -CH-COOCH 2 ), 3.78(s, 3H, -COOCH 3 ), 3.34 – 3.29 (m, 1H, H-9), 3.16 – 3.10 (m, 1H, H-5), 3.05 –2.98 (m, 1H, -CH 2a -CH-NHBoc), 2.75 – 2.68 (m, 1H, H-6), 2.56 (d, J = 10.6 Hz,1H, -CH 2b -CH-NHBoc), 2.12 - 1.96 (m, 1H, H-6), 1.50 (s, 9H, -COOC(CH 3 ) 3 ), 1.49– 1.46 (m, 3H, -N-CH-CH 3 ), 1.45 (s, 9H, Boc). 13 C NMR (100 MHz, CDCl 3) δ172.41, 170.91, 169.34, 166.94, 155.08, 137.20, 136.23, 134.30, 130.77,127.39, 123.07, 121.91, 119.49, 118.98, 111.33, 110.11, 99.99, 83.05, 79.83,63.56, 54.28, 52.43, 51.67, 46.86, 39.51, 36.27, 29.40, 28.37, 28.37, 28.37,28.00, 28.00, 28.00, 15.97. HRMS (ESI, m / z) calcd for C 34 H 43 N 3 O 9 Na, 660.2897,[M+Na] + ; found, 660.2876。

[0085] Table 2 Compounds 8a - 8k

[0086]

[0087] Example 3 Synthesis of Compounds 9a - 9k

[0088] (1) Synthesis of Compound 6

[0089] Dissolve 0.34 mmol of Compound 3 prepared in Example 1 and 1.02 mmol of tert - butyl phenylalaninate hydrochloride in 25.8 mmol of N,N - dimethylformamide, heat and stir at 110 °C. After reacting for 2 h, add ethyl acetate and saturated brine (volume ratio 1:1) for extraction. Collect the organic layer, dry at room temperature and then concentrate. Use column chromatography to separate and purify the concentrate to obtain Compound 6;

[0090] (2) Synthesis of Compounds 9a - 9k

[0091] Dissolve Compound 6 (100 mg, 0.34 mmol), 4 - dimethoxypyridine (49 mg, 0.42 mmol), 1 - ethyl - (3 - dimethylaminopropyl)carbodiimide hydrochloride (193 mg, 1.01 mmol) and carboxylic acid compound (0.50 mmol) in dichloromethane. After reacting at room temperature for 2 h, add ethyl acetate and saturated brine (volume ratio 1:1) for extraction to obtain the organic layer. Dry with anhydrous sodium sulfate at room temperature for 12 h and then concentrate. Use column chromatography to separate and purify the concentrate to obtain one of the pure products 9a - 9k respectively;

[0092] Among them: the carboxylic acid compounds used for compounds 9a - 9k are as follows respectively:

[0093] N-(tert-Butoxycarbonyl)glycine is used for synthesizing 9a; N-(tert-butoxycarbonyl)-D-alanine is used for synthesizing 9b; N-(tert-butoxycarbonyl)-L-valine is used for synthesizing 9c; N-(tert-butoxycarbonyl)-L-isoleucine is used for synthesizing 9d; N-(tert-butoxycarbonyl)-L-phenylalanine is used for synthesizing 9f; N-(tert-butoxycarbonyl)-L-methionine is used for synthesizing 9e; N-tert-butoxycarbonyl-4-methoxy-L-phenylalanine is used for synthesizing 9g; N-(tert-butoxycarbonyl)-O-benzyl-L-serine is used for synthesizing 9h; N-(tert-butoxycarbonyl)-S-benzyl-L-cysteine is used for synthesizing 9i; N-(tert-butoxycarbonyl)-O-benzyl-L-threonine is used for synthesizing 9j; N-(tert-butoxycarbonyl)-L-tryptophan is used for synthesizing 9k.

[0094] The structural formulas of compounds 9a - 9k are shown in Table 3; the appearance and NMR spectral data are as follows:

[0095] Compound 9a: colorless oil (65%), 1 H NMR (400 MHz, CDCl 3 ) δ 7.24 – 7.16 (m, 4H,Ar-H), 7.11 (s, 1H, Ar-H), 7.09 (s, 1H, H-3), 5.72 (s, 1H, H-7), 5.26 (dd, J = 11.1, 5.3 Hz, 1H, -N-CH-CH 2 -Ph), 5.00 (s, 1H, -NH), 4.78 (dd, J = 13.7 Hz,2H, H-10), 3.92 (d, J = 4.2 Hz, 2H, -CH 2 -NH), 3.75 (s, 3H, -COOCH 3 ), 3.54 (d, J = 10.7 Hz, 1H, H-9), 3.46 -3.36 (m, 2H, -N-CH-CH 2 -Ph), 3.91 – 2.95 (m, 1H,H-5), 2.78 – 2.72 (m, 1H, H-6), 1.88 – 1.82 (m, 1H, H-6), 1.45 (s, 9H, -COOC(CH 3 ) 3), 1.45 (s, 9H, Boc). 13 C NMR (100 MHz, CDCl 3 ) δ 169.96, 168.83, 168.51, 166.80, 155.69, 136.52, 136.06, 135.32, 130.18, 128.98, 128.98, 128.54, 128.54, 126.96, 110.54, 82.83, 79.98, 63.27, 57.78, 51.64, 48.57, 42.45, 39.63, 36.34, 36.23, 28.32, 28.32, 28.32, 27.95, 27.95, 27.95。

[0096] Compound 9b: Colorless oil (50%), 1 H NMR (400 MHz, CDCl 3 ) δ 7.24 – 7.15 (m, 1H, Ar-H), 7.11 (d, J J = 1.5 Hz, 1H, Ar-H), 7.09 (s, 1H, H-3), 5.71 (s, 1H, H-7), 5.27 (dd, J J = 11.2, 5.4 Hz, 1H, -N-CH-CH 2 -Ph), 5.07 (d, J J = 5.5 Hz, 1H, -NH), 4.79 (d, J J = 13.5 Hz, 1H, H-10), 4.71 (d, J J = 13.5 Hz, 1H, H-10), 4.40 – 4.26 (m, 1H, -CH-COOCH 2 ), 3.75 (s, 3H, -COOCH 3 ), 3.55 (m, 1H, H-9), 3.47 – 3.33 (m, 2H, -N-CH-CH 2 -Ph), 2.98 (m, 1H, H-5), 2.75 (m, 1H, H-6), 1.92 – 1.81 (m, 1H, H-6), 1.45 (s, 9H, -COOC(CH 3 ) 3 ), 1.44 (s, 9H, Boc), 1.39 (d, J= 7.2 Hz, 3H, -CH-CH 3 ). 13 C NMR (100 MHz, CDCl 3 ) δ 172.89, 168.85, 168.45, 166.81, 155.11, 136.65, 136.06, 135.31, 129.73, 128.98, 128.98, 128.54, 128.54, 126.97, 110.55, 82.82, 79.79, 63.26, 57.75, 51.63, 49.22, 48.67, 39.68, 36.36, 36.21, 28.33, 28.33, 28.33, 27.96, 27.96, 27.96, 18.80。

[0097] Compound 9c: colorless oil (50%), 1 H NMR (400 MHz, CDCl 3 ) δ 7.24 – 7.17 (m, 4H, Ar-H), 7.11 (d, J = 1.7 Hz, 1H, Ar-H), 7.09 (s, 1H, H-3), 5.73 (s, 1H, H-7), 5.26 (dd, J = 11.2, 5.4 Hz, 1H, -N-CH-CH 2 -Ph), 5.04 (d, J = 9.1 Hz, 1H, -NH), 4.80 (d, J = 13.1 Hz, 1H, H-10), 4.71 (d, J = 13.1 Hz, 1H, H-10), 4.22 (dd, J = 9.0, 4.6 Hz, 1H, -CH-COOCH 2 ), 3.75 (s, 3H, -COOCH 3 ), 3.55 – 3.54 (m, 1H, H-9), 3.46 – 3.36 (m, 2H, -N-CH-CH 2 -Ph), 3.03 – 2.95 (m, 1H, H-5), 2.78 – 2.72 (m, 1H, H-6), 2.17 – 2.08 (m, 1H, -CH-(CH 3 ) 2), 1.91 – 1.82 (m, 1H, H-6), 1.45(s, 9H, -COOC(CH 3 ) 3 ), 1.44 (s, 9H, Boc), 0.96 (d, J = 6.8 Hz, 3H, -CH-CH 3 ),0.88 (d, J = 6.9 Hz, 3H, -CH-CH 3 ). 13 C NMR (100 MHz, CDCl 3 ) δ 172.03, 168.87,168.47, 166.83, 155.71, 136.67, 136.07, 135.36, 130.10, 128.98, 128.98,128.54, 128.54, 126.98, 110.54, 82.81, 79.73, 63.16, 58.57, 57.83, 51.63,48.57, 39.68, 36.33, 36.21, 31.40, 28.33, 28.33, 28.33, 27.96, 27.96, 27.96,19.03, 17.55。

[0098] Compound 9d: colorless oil (50%), 1 H NMR (400 MHz, CDCl 3 ) δ 7.25 – 7.16 (m, 4H,Ar-H), 7.11 (d, J = 1.5 Hz, 1H, Ar-H), 7.09 (s, 1H, H-3), 5.71 (s, 1H, H-7),5.26 (dd, J = 11.1, 5.4 Hz, 1H, -N-CH), 4.90 (d, J = 8.6 Hz, 1H, -NH), 4.75(q, J = 13.6 Hz, 2H, H-10), 4.31 (d, J = 5.5 Hz, 1H, -CH-COOCH 2 ), 3.75 (s,3H, -COOCH 3 ), 3.54 (d, J= 10.6 Hz, 1H, H-9), 3.48 – 3.33 (m, 2H, -N-CH-CH 2 -Ph), 3.02 – 2.95 (m, 1H, H-5), 2.78 – 2.72 (m, 1H, H-6), 1.92 – 1.81 (m, 1H,H-6), 1.74 – 1.66 (m, 2H, -CH 2 -CH-(CH 3 ) 2 ), 1.64 – 1.57 (m, 1H, -CH-(CH 3 ) 2 ),1.45 (s, 9H, -COOC(CH 3 ) 3 ), 1.44 (s, 9H, Boc), 0.94 (dd, J = 6.5, 2.2 Hz, 6H, -CH-(CH 3 ) 2 ). 13 C NMR (100 MHz, CDCl 3 ) δ 173.08, 168.87, 168.49, 166.83, 155.43,136.68, 136.07, 135.35, 129.74, 128.98, 128.98, 128.54, 128.54, 126.98,110.56, 82.80, 79.77, 63.24, 57.80, 52.13, 51.62, 48.59, 41.91, 39.66, 36.35,36.24, 28.33, 28.33, 28.33, 27.95, 27.95, 27.95, 24.79, 22.85, 21.97。

[0099] Compound 9e: colorless oil (88%), 1 H NMR (400 MHz, CDCl 3 ) δ 7.25 – 7.17 (m, 4H,Ar-H), 7.11 (d, J = 1.4 Hz, 1H, Ar-H), 7.09 (s, 1H, H-3), 5.72 (s, 1H, H-7),5.26 (dd, J = 11.2, 5.3 Hz, 1H, -N-CH), 5.14 (d, J= 7.6 Hz, 1H, -NH), 4.75(dd, J = 13.1 Hz, 2H, H-10), 4.42 (d, J = 5.0 Hz, 1H, -CH-COOCH 2 ), 3.75 (s,3H, -COOCH 3 ), 3.56 (m, 1H, H-9), 3.47 – 3.36 (m, 2H, -N-CH-CH 2 -Ph), 3.01 –2.95 (m, 1H, H-5), 2.79 – 2.73 (m, 1H, H-6), 2.54 (dd, J = 12.6, 5.1 Hz, 2H,-S-CH 2 ), 2.19 – 2.10 (m, 1H, H-6), 2.08 (s, 3H,-S-CH 3 ), 195 – 1.84 (m, 2H, -S-CH 2 -CH 2 ), 1.46 (s, 9H, -COOC(CH 3 ) 3 ), 1.44 (s, 9H, Boc). 13 C NMR (100 MHz,CDCl 3 ) δ 171.90, 168.83, 168.39, 166.80, 155.34, 136.47, 136.06, 135.31,130.16, 128.99, 128.99, 128.54, 128.54, 126.98, 110.55, 82.83, 79.99, 63.46,57.79, 52.82, 51.64, 48.65, 39.74, 36.36, 36.16, 32.33, 29.93, 28.31, 28.31,28.31, 27.96, 27.96, 27.96, 15.48. HRMS (ESI, m / z) calcd for C 34 H 46 N 2 O 9 SK,697.2561, [M+K] + ; found, 697.2598。

[0100] Compound 9f: colorless oil (45%),1 H NMR (400 MHz, CDCl 3 ) δ 7.28 (s, 1H, Ar-H), 7.26 – 7.16 (m, 6H, Ar-H), 7.16 – 7.10 (m, 3H, Ar-H), 7.09 (s, 1H, H-3), 5.64 (s, 1H, H-7), 5.28 (dd, J J = 11.0, 5.4 Hz, 1H, -N-CH-CH 2 -Ph), 4.99 (d, J J = 8.6 Hz, 1H, -NH), 4.78 (d, J J = 13.2 Hz, 1H, H-10), 4.69 (d, J J = 13.2 Hz, 1H, H-10), 4.58 (d, J J = 7.5 Hz, 1H, -CH-COOCH 2 ), 3.76 (s, 3H, -COOCH 3 ), 3.43 – 3.39 (m, 1H, H-9), 3.37 (d, J J = 5.3 Hz, 2H, -N-CH-CH 2 -Ph), 3.07 (s, 2H, -CH 2 -CH-NHBoc), 3.02 – 2.95 (m, 1H, H-5), 2.76 – 2.67 (m, 1H, H-6), 1.84 – 1.80 (m, 1H, H-6), 1.46 (s, 9H, -COOC(CH 3 ) 3 ), 1.41 (s, 9H, Boc). 13 C NMR (100 MHz, CDCl 3) δ 171.53, 168.89, 168.54, 166.82, 155.00, 136.48, 136.05, 135.34,130.32, 129.40, 128.98, 128.98, 128.98, 128.98, 128.54, 128.54, 128.54,128.54, 126.98, 126.98, 110.49, 82.82, 79.86, 63.39, 57.69, 54.46, 51.64,48.34, 39.56, 38.51, 36.41, 36.23, 28.31, 28.31, 28.31, 27.97, 27.97,27.97.HRMS (ESI, m / z) calcd for C 38 H 46 N 2 O 9 Na, 697.3101, [M+Na] + ; found, 697.3135。

[0101] Compound 9g: colorless oil (88%), 1 H NMR (400 MHz, CDCl 3 ) δ 7.24 – 7.15 (m, 4H, Ar-H), 7.11 (s, 1H, Ar-H), 7.09 (s, 1H, H-3), 7.05 (d, J J = 8.5 Hz, 2H, Ar-H), 6.81 (d, J J = 8.6 Hz, 2H, Ar-H), 5.66 (s, 1H, H-7), 5.27 (dd, J J = 11.1, 5.4 Hz, 1H, -N-CH-CH 2 -Ph), 4.97 (d, J J = 8.2 Hz, 1H, -NH), 4.79 (d, J J = 13.3 Hz, 1H, H-10), 4.70 (d, J J = 13.3 Hz, 1H, H-10), 4.54 (d, J J = 7.7 Hz, 1H, -CH-COOCH 2 ), 3.76 (s, 3H, -COOCH 3 ), 3.75 (s, 3H, -OCH3 ), 3.44 – 3.40 (m, 1H, H-9), 3.38 – 3.32 (m, 2H, -N-CH-CH 2 -Ph), 3.02 (s, 1H, -CH 2 -CH-NHBoc), 2.99 – 2.92 (m, 1H, H-5), 2.75 – 2.69 (m, 1H, H-6), 1.86 – 1.80 (m, 1H, H-6), 1.45 (s, 9H, -COOC(CH 3 ) 3 ), 1.41 (s, 9H, Boc). 13 C NMR (100 MHz, CDCl 3 ) δ 171.58, 168.86, 168.53, 166.82, 158.65, 155.14, 136.51, 136.07, 135.36, 130.39, 130.39, 130.26, 128.98, 128.98, 128.54, 128.54, 127.95, 126.98, 113.94, 113.94, 110.52, 82.81, 79.84, 63.32, 57.78, 55.21, 54.54, 51.63, 48.44, 39.60, 37.54, 36.38, 36.24, 28.32, 28.32, 28.32, 27.96, 27.96, 27.96。

[0102] Compound 9h: colorless oil (12%), 1 H NMR (400 MHz, CDCl 3 ) δ 7.35 – 7.27 (m, 4H, Ar-H), 7.25 (s, 1H, Ar-H), 7.22 – 7.15 (m, 4H, Ar-H), 7.10 (d, J J = 1.6 Hz, 1H, Ar-H), 7.09 (s, 1H, H-3), 5.67 (s, 1H, H-7), 5.40 (d, J J = 9.2 Hz, 1H, -NH), 5.31 – 5.24 (m, 1H, -CH-CH 2 -Ph), 4.84 (d, J J = 14.0 Hz, 1H, H-10), 4.73 (d,J = 14.0 Hz, 1H, H-10), 4.51 (d, J = 6.9 Hz, 2H, -O-CH 2 -Ph), 4.45 (d, J =9.2 Hz, 1H, -O-CH 2 -CH), 3.89 (dd, J = 9.2, 2.9 Hz, 1H, -O-CH 2a -CH), 3.75 (s,3H, -COOCH 3 ), 3.69 (dd, J = 9.4, 3.2 Hz, 1H, -O-CH 2b -CH), 3.48 (m, 1H, H-9),3.41 – 3.33 (m, 2H, -CH-CH 2 -Ph), 3.01 – 2.94 (m, 1H, H-5), 2.72 - 2.65 (m,1H, H-6), 1.84 – 1.78 (m, 1H, H-6), 1.45 (s, 9H, -COOC(CH 3 ) 3 ), 1.44 (s, 9H,Boc). 13 C NMR (100 MHz, CDCl 3 ) δ 170.22, 168.86, 168.48, 166.81, 155.49,137.49, 136.54, 136.06, 135.31, 129.51, 128.98, 128.98, 128.53, 128.53,128.41, 128.41, 127.81, 127.81, 127.65, 126.96, 110.55, 82.79, 79.93, 73.36,70.19, 63.48, 57.70, 54.05, 51.60, 48.67, 39.63, 36.40, 36.23, 28.33, 28.33,28.33, 27.95, 27.95, 27.95. HRMS (ESI, m / z): calcd for C 39 H 48 N 2 O 10 Na, 727.3207,[M+Na] + ; found, 727.3214。

[0103] Compound 9i: Colorless oil (51%), 1 H NMR (400 MHz, CDCl 3 ) δ 7.29 (d, J J = 4.3Hz, 4H, Ar-H), 7.24 – 7.13 (m, 5H, Ar-H), 7.10 (d, J J = 1.5 Hz, 1H, Ar-H),7.08 (s, 1H, H-3), 5.70 (s, 1H, H-7), 5.29 – 5.25 (m, 2H, overlap, -NH, -N-CH), 4.81 (d, J J = 13.4 Hz, 1H, H-10), 4.72 (d, J J = 13.4 Hz, 1H, H-10), 4.52(d, J J = 7.2 Hz, 1H, -CH-COOCH 2 ), 3.75 (s, 3H, -COOCH 3 ), 3.72 (s, 2H, -S-CH 2 -Ph), 3.51 – 3.48 (m, 1H, H-9), 3.44 – 3.36 (m, 2H, -N-CH-CH 2 -Ph), 3.01 – 2.94(m, 1H, H-5), 2.91 – 2.77 (m, 2H, -S-CH 2 -CH), 2.77 – 2.71 (m, 1H, H-6), 1.87– 1.81 (m, 1H, H-6), 1.45 (s, 18H, overlap, -COOC(CH 3 ) 3, Boc). 13 C NMR (100MHz, CDCl 3) δ 170.70, 168.84, 168.43, 166.80, 155.19, 137.71, 136.39, 136.06, 135.33, 130.14, 128.98, 128.98, 128.98, 128.98, 128.57, 128.57, 128.53, 128.53, 127.18, 126.96, 110.52, 82.81, 80.08, 63.59, 57.71, 53.15, 51.63, 48.59, 39.67, 36.61, 36.39, 36.21, 33.72, 28.33, 28.33, 28.33, 27.96, 27.96, 27.96. HRMS (ESI, m / z) calcd for C 39 H 48 N 2 O 9 SNa, 743.2978, [M+Na] + ; found, 743.2939。

[0104] Compound 9j: colorless oil (53%), 1 H NMR (400 MHz, CDCl 3 ) δ 7.33 – 7.28 (m, 2H, Ar-H), 7.26 – 7.04 (m, 9H, Ar-H, H-3), 5.67 (s, 1H, H-7), 5.30 (d, J = 9.6 Hz, 1H, -N-CH), 5.25 (dd, J = 11.1, 5.4 Hz, 1H, -NH), 4.74 (s, 2H, H-10), 4.53 (d, J = 11.6 Hz, 1H, -O-CH 2a ), 4.38 (d, J = 11.6 Hz, 1H, -O-CH 2b ), 4.32 (dd, J = 9.6, 2.1 Hz, 1H, -CH-CH 3 ), 4.16 – 4.12 (m, 1H, -CH-NHBoc), 3.74 (s, 3H, -COOCH 3), 3.50 – 3.48 (m, 1H, H-9), 3.41 – 3.27 (m, 2H, -O-CH 2 ), 3.00 –2.94 (m, 1H, H-5), 2.70 – 2.64 (m, 1H, H-6), 1.91 – 1.75 (m, 1H, H-6), 1.45(s, 18H, -COOC(CH 3 ) 3, Boc), 1.26 (s, 3H, -CH-CH 3 ). 13 C NMR (100 MHz, CDCl 3 ) δ170.72, 168.87, 168.47, 166.83, 156.16, 137.95, 136.57, 136.06, 135.33,129.70, 128.97, 128.97, 128.54, 128.54, 128.34, 128.34, 127.69, 127.62,126.97, 110.54, 82.79, 79.82, 74.79, 70.99, 63.38, 58.23, 57.77, 51.61,51.61, 48.68, 39.63, 36.36, 36.21, 28.33, 28.33, 28.33, 27.95, 27.95, 27.95,16.38。

[0105] Compound 9k: Colorless oil (9%), 1 H NMR (400 MHz, CDCl 3 ) δ 8.49 (s, 1H, -NH in indole), 7.62 (d, J = 7.5 Hz, 1H, Ar-H), 7.29 (d, J = 7.6 Hz, 1H, Ar-H), 7.24(s, 1H, Ar-H), 7.21 - 7.15 (m, 3H, Ar-H), 7.15 – 7.11 (m, 2H, Ar-H), 7.10 (s,1H, H-3), 7.07 (d, J = 5.6 Hz, 2H, Ar-H), 6.91 (d, J= 2.0 Hz, 1H, -CH in pyrrole ring), 5.53 (s, 1H, H-7), 5.42 (dd, J = 11.2, 5.5 Hz, 1H, -CH-CH 2 -Ph), 5.15 (d, J = 8.0 Hz, 1H, -NH), 4.96 (d, J = 12.4 Hz, 1H, H-10), 4.70 (d, J = 5.3 Hz, 1H, -CH-COOCH 2 ), 4.47 (d, J = 12.4 Hz, 1H, H-10), 3.77 (s, 3H, -COOCH 3 ), 3.45 – 3.40 (m, 1H, H-9), 3.35 – 3.24 (m, 1H, -N-CH-CH 2a -Ph), 3.15(dd, J = 14.2, 8.1 Hz, 1H, -N-CH-CH 2b -Ph), 3.00 – 2.89 (m, 2H, -CH 2 -CH-COO),2.57 - 2.48 (m, 2H, overlap, H-5, H-6), 2.05 – 1.99(m, 1H, H-6), 1.51 (s, 9H,-COOC(CH 3 ) 3 ), 1.44 (s, 9H, Boc). HRMS (ESI, m / z) calcd for C 40 H 47 N 3 O 9 Na,736.3210, [M+Na] + ; found, 736.3210.

[0106] Table 3 Structural formulas of compounds 9a - 9k

[0107]

[0108] Example 4 Synthesis of compounds 10a - 10k

[0109] As shown in Synthetic Route 2, using 7a - 7k prepared in Example 1 as starting materials, reacting with trifluoroacetic acid in dichloromethane solution to obtain compounds 10a - 10k.

[0110]

[0111] Synthetic Route 2

[0112] Reaction conditions and reagents in Synthetic Route 2: (e) Trifluoroacetic acid, dichloromethane.

[0113] The specific steps are as follows:

[0114] (1) Synthesis of compounds 10a - 10k

[0115] Dissolve one of the compounds 7a - 7k (0.34 mmol) and trifluoroacetic acid (6.4 mmol) in dichloromethane, react at room temperature for 0.5 h, then add ethyl acetate and saturated brine (volume ratio 1:1) for extraction to obtain the organic layer. Dry it with anhydrous sodium sulfate at room temperature for 12 h and then concentrate. Use column chromatography to separate and purify the concentrate to obtain one of the pure products 10a - 10k respectively;

[0116] Among them: Use 7a for synthesizing 10a, 7b for synthesizing 10b, 7c for synthesizing 10c, 7d for synthesizing 10d, 7f for synthesizing 10f, 7e for synthesizing 10e, 7g for synthesizing 10g, 7h for synthesizing 10h, 7i for synthesizing 10i, 7j for synthesizing 10j, 7k for synthesizing 10k.

[0117] The structural formulas of compounds 10a - 10k are shown in Table 4; the appearance and NMR spectral data are as follows:

[0118] Compound 10a: Colorless oil (65%), 1 H NMR (400 MHz, MeOD) δ 7.33 (s, 1H, H - 3), 5.84 (s, 1H, H - 7), 4.10 – 4.30 (m, 2H, H - 10), 4.29 – 4.16 (m, 2H, -N - CH 2 ), 3.75 (s, 3H, -COOCH 3 ), 3.66 (d, J = 10.6 Hz, 2H, -CH 2 -NH 2), 3.57 – 3.50 (m, 2H, overlap, H-9, H-5), 2.97 – 2.72 (m, 1H, H-6), 2.34 – 2.11 (m, 1H, H-6), 1.45 (s, 9H, -COOC(CH 3 ) 3 )。

[0119] Compound 10b: colorless oil (50%), 1 H NMR (400 MHz, CDCl 3 ) δ 7.15 (s, 1H, H-3), 5.88 (s, 1H, H-7), 5.05 – 4.89 (m, 2H, H-10), 4.27 – 4.09 (m, 2H, -N-CH 2 ), 3.76 (s, 3H, -COOCH 3 ), 3.67 (d, J J = 10.7 Hz, 1H, -CH-NH 2 ), 3.59 - 3.57 (m, 2H, overlap, H-9, H-5), 2.96 - 2.90 (m, 1H, H-6), 2.39 – 2.23 (m, 1H, H-6), 1.46 (s, 9H, -COOC(CH 3 ) 3 ), 1.36 (d, J J = 7.0 Hz, 3H, -CH-CH 3 ). 13 C NMR (100 MHz, CDCl 3 ) δ 176.17, 168.94, 166.96, 166.80, 137.85, 137.10, 129.97, 110.55, 82.82, 63.07, 51.65, 50.10, 49.59, 49.25, 48.48, 42.00, 37.12, 28.02, 28.02, 28.02, 20.65。

[0120] Compound 10c: colorless oil (50%), 1 H NMR (400 MHz, CDCl 3) δ 7.15 (s, 1H, H-3), 5.90 (s, 1H, H-7), 5.10 – 4.89 (m, 2H, H-10), 4.34 – 4.01 (m, 2H, -N-CH 2 ), 3.76 (s, 3H, -COOCH 3 ), 3.67 (d, J J = 10.7 Hz, 1H, H-9), 3.61 - 3.54 (m, 1H, H-5), 3.32 (d, J J = 4.9 Hz, 1H, -CH-NH 2 ), 2.96 – 2.90 (m, 1H, H-6), 2.38 – 2.15(m, 1H, H-6), 2.09 – 2.01 (m, 1H, -CH-CH 3 ), 1.46 (s, 9H, -COOC(CH 3 ) 3 ), 0.99(d, J J = 6.9 Hz, 3H, -CH-CH 3 ), 0.91 (d, J J = 6.8 Hz, 3H, -CH-CH 3 ). 13 C NMR (100 MHz, CDCl 3 ) δ 175.23, 168.94, 166.96, 166.81, 137.87, 137.17, 130.27, 110.52, 82.80, 62.92, 59.98, 51.65, 49.27, 48.39, 40.01, 37.11, 32.12, 28.02, 28.02, 28.02, 19.37, 17.14。

[0121] Compound 10d: Colorless oil (50%), 1 H NMR (400 MHz, CDCl 3 ) δ 7.15 (s, 1H, H-3), 5.89 (s, 1H, H-7), 4.98 (s, 2H, H-10), 4.16 (q, J J = 17.2 Hz, 2H, -N-CH 2 ), 3.76 (s, 3H, -COOCH 3), 3.67 - 3.66 (m, 1H, H-9), 3.62 - 3.55 (m, 1H, H-5), 3.55 – 3.47 (m, 1H, -CH-NH 2 ), 2.96 – 2.90 (m, 1H, H-6), 2.40 – 2.24 (m, 1H, H-6), 1.86 – 1.76 (m, 2H, -CH 2 -CH-CH 3 ), 1.61 - 1.57 (m, 1H, -CH-CH 3 ), 1.46 (s, 9H, -COOC(CH 3 ) 3 ), 0.93 (dd, J = 8.0, 6.7 Hz, 6H, -CH-(CH 3 ) 2 ). 13 C NMR (100 MHz, CDCl 3 ) δ 176.16, 168.96, 166.96, 166.80, 137.86, 137.11, 130.07, 110.55, 82.81, 63.05, 52.92, 51.65, 49.25, 48.43, 43.98, 39.99, 37.14, 28.03, 28.03, 28.03, 24.77, 22.98, 21.87。

[0122] Compound 10e: Colorless oil (88%), 1 H NMR (400 MHz, CDCl 3 ) δ 7.15 (s, 1H, H-3), 5.89 (s, 1H, H-7), 4.99 (s, 2H, H-10), 4.17 (dd, J = 8.6, 3.7 Hz, 2H, -N-CH 2 ), 3.76 (s, 3H, -COOCH 3 ), 3.69 – 3.55 (m, 3H, overlap, H-9, H-5, -CH-NH 2 ), 2.96 – 2.90 (m, 1H, H-6), 2.64 (t, J = 7.4 Hz, 2H, -S-CH 2), 2.38 – 2.26 (m,1H, H-6), 2.10 (s, 3H, -S-CH 3 ), 2.07 – 1.98 (m, 1H, -S-CH 2 -CH 2a ), 1.86 – 1.81(m, 1H, -S-CH 2 -CH 2b ), 1.46 (s, 9H). 13 C NMR (100 MHz, CDCl 3 ) δ 175.33, 168.91,166.95, 166.79, 137.85, 136.96, 130.34, 110.56, 82.84, 63.25, 53.39, 51.67,49.26, 48.49, 40.04, 37.11, 33.89, 30.48, 28.04, 28.04, 29.04, 15.41。

[0123] Compound 10f: Colorless oil (45%), 1 H NMR (400 MHz, CDCl 3 ) δ 7.31 - 7.27 (m, 2H,Ar-H), 7.24 – 7.17 (m, 3H, Ar-H), 7.15 (s, 1H, H-3), 5.81 (s, 1H, H-7), 5.03- 4.93 (m, 2H, H-10), 4.30 – 3.98 (m, 2H, -N-CH 2 ), 3.81 – 3.77 (m, 1H, -CH-NH 2 ), 3.76 (s, 3H, -COOCH 3 ), 3.56 – 3.48 (m, 2H, overlap, H-9, H-5), 3.12 –3.08 (m, 1H, -CH 2a -Ph), 2.94 – 2.88 (m, 2H, overlap, H-6, -CH 2b -Ph), 2.36 –2.16 (m, 1H, H-6), 1.46 (s, 9H, -COOC(CH 3 ) 3 ). 13 C NMR (100 MHz, CDCl 3) δ174.59, 169.01, 166.97, 166.81, 137.86, 137.13, 136.92, 130.48, 129.35,129.35, 128.58, 128.58, 126.82, 110.52, 82.83, 63.21, 55.85, 51.66, 49.23,48.25, 41.02, 39.96, 37.13, 28.04, 28.04, 28.04。

[0124] 10 g of the compound: colorless oil (88%), 1 H NMR (400 MHz, CDCl 3 ) δ 7.15 (s, 1H, H-3), 7.12 (d, J J = 8.6 Hz, 2H, Ar-H), 6.83 (d, J J = 8.6 Hz, 2H, Ar-H), 5.82 (s, 1H, H-7), 5.04 - 4.92 (m, 2H, H-10), 4.16 (s, 2H, -N-CH 2 ), 3.78 (s, 3H, -COOCH 3 ), 3.76 (s, 3H, -OCH 3 ), 3.74 – 3.69 (m, 1H, -CH-NH 2 ), 3.56 – 3.53 (m, 2H, overlap, H-9, H-5), 3.10 – 2.98 (m, 1H, -CH 2a -Ph), 2.92 – 2.83 (m, 1H, H-6), 2.88 – 2.81 (m, 1H, -CH 2b -Ph), 2.30 – 2.20 (m, 1H, H-6), 1.46 (s, 9H, -COOC(CH 3 ) 3 ). 13 C NMR (100 MHz, CDCl 3) δ 174.85, 169.01, 166.98, 166.82, 158.50, 137.88, 137.00, 130.39, 130.34, 130.34, 129.12, 113.97, 113.97, 110.50, 82.82, 63.15, 55.98, 55.23, 51.67, 49.25, 48.23, 40.19, 39.95, 37.16, 28.04, 28.04, 28.04。

[0125] Compound 10h: colorless oil (12%), 1 H NMR (400 MHz, CDCl 3 ) δ 7.36 – 7.32 (m, 5H, Ar-H), 7.15 (d, J J = 0.9 Hz, 1H, H-3), 5.86 (s, 1H, H-7), 5.03 (q, J J = 13.7 Hz, 2H, H-10), 4.61 – 4.46 (m, 2H, -CH 2 -Ph), 4.16 (s, 2H, -N-CH 2 ), 3.86 – 3.79 (m, 1H, -CH-NH 2 ), 3.77 (s, 3H, -COOCH 3 ), 3.75 – 3.49 (m, 4H, overlap, H-9, H-5, -O-CH 2 -CH), 2.92 – 2.85 (m, 1H, H-6), 2.29 – 2.23 (m, 1H, H-6), 1.47 (s, 9H, -COOC(CH 3 ) 3 )。

[0126] Compound 10i: colorless oil (51%), 1 H NMR (400 MHz, CDCl 3 ) δ 7.30 (dd, J J = 6.9, 4.4 Hz, 4H, Ar-H), 7.25 – 7.18 (m, 1H, Ar-H), 7.14 (d, J J = 3.4 Hz, 1H, H-3), 5.87 (s, 1H, H-7), 4.99 (q, J= 13.3 Hz, 2H, H-10), 4.35 – 4.05 (m, 2H, -N-CH 2 ), 3.76 (s, 3H, -COOCH 3 ), 3.74 (s, 2H, -CH 2 -Ph), 3.65 – 3.46 (m, 3H,overlap, H-9, H-5, -CH-NH 2 ), 2.95 – 2.82 (m, 2H, overlap, H-6, -S-CH 2a -CH),2.72 – 2.62 (m, 1H, -S-CH 2b -CH), 2.33 – 2.23 (m, 1H, H-6), 1.45 (s, 9H, -COOC(CH 3 ) 3 ). 13 C NMR (100 MHz, CDCl 3 ) δ 173.55, 168.93, 166.95, 166.80, 137.93,137.86, 136.81, 130.37, 128.96, 128.96, 128.58, 128.58, 127.17, 110.54,82.82, 63.40, 54.14, 51.67, 49.23, 48.41, 40.02, 37.12, 36.63, 36.40, 28.04,28.04, 28.04。

[0127] Compound 10j: colorless oil (53%), 1 H NMR (400 MHz, CDCl 3 ) δ 7.33 – 7.27 (m,4H, Ar-H), 7.25 (s, 1H, Ar-H), 7.12 (s, 1H, H-3), 5.85 (s, 1H, H-7), 5.08 –4.87 (m, 2H, H-10), 4.56 (t, J = 10.4 Hz, 1H, -O-CH 2a ), 4.46 – 4.36 (m, 1H, -O-CH 2b ), 4.15 (d, J = 13.4 Hz, 2H, -N-CH 2), 4.07 – 3.93 (m, 1H, -O-CH), 3.75(s, 3H, -COOCH 3 ), 3.61 (d, J = 10.7 Hz, 1H, -CH-COO), 3.55 – 3.40 (m, 2H,overlap, H-9, H-5), 2.88 – 2.82 (m, 1H, H-6), 2.26 – 2.20 (m, 1H, H-6), 1.45(s, 9H, -COOC(CH 3 ) 3 )。

[0128] Compound 10k: Colorless oil (42%), 1 H NMR (400 MHz, CDCl 3 ) δ 8.69 (s, 1H, -NHin indole), 7.62 (d, J = 7.5 Hz, 1H, Ar-H), 7.33 (d, J = 7.7 Hz, 1H, Ar-H),7.19 – 7.04 (m, 4H, Ar-H, H-3), 6.96(d, J = 1.9 Hz, 1H, -CH in pyrrole ring),5.72 (s, 1H, H-7), 5.15 (d, J = 12.9 Hz, 1H, H-10), 4.63 (d, J = 12.7 Hz, 1H,H-10), 4.45 (d, J = 17.3 Hz, 1H, -CH-NH 2 ), 3.96 – 3.84 (m, 2H, -N-CH 2 ), 3.78(s, 3H, -COOCH 3 ), 3.28 – 3.03 (m, 3H, overlap, H-9, H-5, -CH 2a -CH-NH 2 ), 2.82 –2.59 (m, 2H, overlap, -CH 2b -CH-NH 2 , H-6), 2.17 – 2.08 (m, 1H, H-6), 1.52 (s,9H, -COOC(CH 3 )3 )。

[0129] Table 4 Structural Formulas of Compounds 10a - 10k

[0130]

[0131] Example 5 Synthesis of Compounds 11a - 11k

[0132] Dissolve one of the compounds 8a - 8k in Example 2 (0.34 mmol) and trifluoroacetic acid (6.4 mmol) in dichloromethane. After reacting at room temperature for 0.5 h, add ethyl acetate and saturated brine (volume ratio 1:1) for extraction to obtain the organic layer. Dry it with anhydrous sodium sulfate at room temperature for 12 h and then concentrate it. Use column chromatography to separate and purify the concentrate to obtain one of the pure products 11a - 11k respectively;

[0133] Among them: 8a is used for synthesizing 11a, 8b is used for synthesizing 11b, 8c is used for synthesizing 11c, 8d is used for synthesizing 11d, 8f is used for synthesizing 11f, 8e is used for synthesizing 11e, 8g is used for synthesizing 11g, 8h is used for synthesizing 11h, 8i is used for synthesizing 11i, 8j is used for synthesizing 11j, and 8k is used for synthesizing 11k.

[0134] The structural formulas of compounds 11a - 11k are shown in Table 5; the appearance and NMR spectral data are as follows:

[0135] Compound 11a: Colorless oil (65%) 1 H NMR (400 MHz, CDCl 3 ) δ 7.19 (s, 1H, H - 3), 5.77 (s, 1H, H - 7), 5.01 – 4.82 (m, 2H, H - 10), 4.36 – 4.16 (m, 1H, -N-CH), 3.70 (s, 3H, -COOCH 3 ), 3.49 (ddd, J = 13.6, 9.8, 6.4 Hz, 2H, H - 9, H - 5), 2.93– 2.76 (m, 1H, H - 6), 2.26 – 2.07 (m, 1H, H - 6), 1.42 (d, J = 7.4 Hz, 3H, -N-CH-CH 3 ), 1.38 (s, 9H, -COOC(CH 3 ) 3 )。

[0136] Compound 11b: Colorless oil (50%),1 1H NMR (400 MHz, CDCl 3 ) δ 7.28 (s, 1H, H-3), 5.87 (s, 1H, H-7), 5.03 – 4.96 (m, 3H, overlap, H-10, -N-CH), 3.76 (s, 3H, -COOCH 3 ), 3.67 (d, J J = 10.8 Hz, 1H, -CH-NH 2 ), 3.62 – 3.52 (m, 2H, overlap, H-9, H-5), 2.99 – 2.87 (m, 1H, H-6), 2.29 – 2.16 (m, 1H, H-6), 1.48 (d, J J = 7.4 Hz, 3H, -N-CH-CH 3 ), 1.44 (s, 9H, -COOC(CH 3 ) 3 ), 1.37 (s, 3H, NH 2 -CH-CH 3 ). 13 13C NMR (100 MHz, CDCl 3 ) δ 176.20, 169.85, 168.69, 166.89, 137.32, 134.92, 129.89, 110.66, 82.46, 63.06, 52.92, 51.65, 50.13, 48.89, 40.09, 36.50, 27.94, 27.94, 27.94, 20.68, 15.96。

[0137] Compound 11c: colorless oil (55%), 1 1H NMR (400 MHz, CDCl 3 ) δ 7.28 (s, 1H, H-3), 5.89 (s, 1H, H-7), 4.98 (q, J J = 7.4 Hz, 3H, overlap, H-10, -N-CH), 3.76 (s, 3H, -COOCH 3 ), 3.68 – 3.65 (m, 1H, H-9), 3.60 – 3.49 (m, 1H, H-5), 3.32 (d, J J = 4.9 Hz, 1H, -CH-CH-CH3 ), 2.96 – 2.90 (m, 1H, H-6), 2.28 – 2.16 (m, 1H, H-6), 2.10 – 2.00 (m, 1H, -CH-CH-CH 3 ), 1.48 (d, J J = 7.4 Hz, 3H, -N-CH-CH 3 ), 1.44(s, 9H, -COOC(CH 3 ) 3 ), 0.99 (d, J J = 6.9 Hz, 3H, -CH-CH-CH 3 ), 0.91 (d, J J = 6.8Hz, 3H, -CH-CH-CH 3 ). 13 C NMR (100 MHz, CDCl 3 ) δ 175.18, 169.85, 168.67,166.89, 137.35, 134.93, 130.18, 110.61, 82.41, 62.89, 59.95, 52.95, 51.63,48.80, 40.08, 36.46, 32.10, 27.91, 27.91, 27.91, 19.35, 17.12, 15.90。

[0138] Compound 11d: colorless oil (50%), 1 1H NMR (400 MHz, CDCl 3 ) δ 7.28 (s, 1H, H-3),5.88 (s, 1H, H-7), 5.10 – 4.88 (m, 3H, overlap, H-10, -N-CH), 3.76 (d, J J =7.1 Hz, 3H, -COOCH 3 ), 3.66 (d, J J = 10.7 Hz, 1H, -CH-NH 2 ), 3.61 – 3.42 (m, 2H,overlap, H-9, H-5), 2.96 – 2.90 (m, 1H, H-6), 2.31 – 2.12 (m, 1H, H-6), 1.83– 1.75 (m, 2H, -CH 2 -CH-(CH 3 )2 ), 1.62 – 1.56 (m, 1H, -CH-(CH 3 ) 2 ), 1.48 (d, J J =7.4 Hz, 3H, -N-CH-CH 3 ), 1.44 (s, 9H, -COOC(CH 3 ) 3 ), 0.95 – 0.91 (m, 6H, -CH-(CH 3 ) 2 ). 13 C NMR (100 MHz, CDCl 3 ) δ 176.19, 169.81, 168.66, 166.86, 137.35,134.93, 129.91, 110.64, 82.40, 62.99, 52.93, 51.60, 48.84, 44.05, 40.07,36.51, 31.42, 27.91, 27.91, 27.91, 24.76, 22.96, 21.87, 15.92。

[0139] Compound 11e: colorless oil (88%), 1 H NMR (400 MHz, CDCl 3 ) δ 7.27 (s, 1H, H-3),5.88 (s, 1H, H-7), 5.07 – 4.89 (m, 3H, overlap, H-10, -N-CH), 3.76 (s, 3H, -COOCH 3 ), 3.70 – 3.59 (m, 2H, overlap, H-9, H-5), 3.60 – 3.49 (m, 1H, -CH-NH 2 ),2.96 – 2.90 (m, 1H, H-6), 2.64 (t, J J = 7.3 Hz, 2H, -S-CH 2 ), 2.30 – 2.18 (m,1H, H-6), 2.09 (d, J J = 5.6 Hz, 3H, -S-CH 3 ), 2.07 – 2.02 (m, 1H, -CH-CH 2a ),1.83 (m, 1H, -CH-CH 2b ), 1.48 (d,J = 7.4 Hz, 3H, -N-CH-CH 3 ), 1.44 (s, 9H, -COOC(CH 3 ) 3 )。

[0140] Compound 11f: Colorless oil (45%), 1 H NMR (400 MHz, CDCl 3 ) δ 7.29 – 7.27 (m, 4H,Ar-H), 7.24 – 7.19 (m, 2H, Ar-H, H-3), 5.79 (s, 1H, H-7), 5.04 – 4.90 (m, 3H,overlap, H-10, -N-CH), 3.77 (s, 3H, -COOCH 3 ), 3.75 – 3.69 (m, 1H, -CH-NH 2 ),3.54 – 3.51 (m, 2H, overlap, H-5, H-9), 3.11 – 3.07 (m, 1H, -CH 2a -Ph), 2.93 –2.88 (m, 2H, overlap, H-6, -CH 2b -Ph), 2.26 – 2.11 (m, 1H, H-6), 1.47 (d, J =7.4 Hz, 3H, -N-CH-CH 3 ), 1.44 (s, 9H, -COOC(CH 3 ) 3 )。

[0141] Compound 11g: Colorless oil (88%), 1 H NMR (400 MHz, CDCl 3 ) δ 7.28 (s, 1H, H-3),7.12 (d, J = 8.5 Hz, 2H, Ar-H), 6.83 (d, J = 8.5 Hz, 2H, Ar-H), 5.80 (s, 1H,H-7), 5.05 – 4.92 (m, 3H, overlap, H-10, -N-CH), 3.78 (s, 3H, -OCH 3 ), 3.77(s, 3H, -COOCH 3), 3.75 – 3.69 (m, 1H, -CH-NH 2 ), 3.60 – 3.46 (m, 2H, overlap, H-9, H-5), 3.12 – 2.98 (m, 1H, -CH 2a -Ph), 2.95 – 2.80 (m, 2H, overlap, H-6, -CH 2b -Ph), 2.29 – 2.12 (m, 1H, H-6), 1.48 (d, J = 7.4 Hz, 3H, -N-CH-CH 3 ), 1.44(s, 9H, -COOC(CH 3 ) 3 ).

[0142] Compound 11h: colorless oil (12%), 1 H NMR (400 MHz, CDCl 3 ) δ 7.38 – 7.27 (m, 5H, Ar-H), 7.27 (d, J = 1.7 Hz, 1H, H-3), 5.83 (s, 1H, H-7), 5.08 – 4.89 (m, 3H, overlap, H-10, -N-CH), 4.61 – 4.43 (m, 2H, -CH 2 -Ph), 3.80 – 3.78 (m, 1H, -CH-NH 2 ), 3.76 (s, 3H, -COOCH 3 ), 3.75 – 3.65 (m, 2H, overlap, H-9, H-5), 3.61 (d, J = 10.8 Hz, 1H, -CH-CH 2a -O), 3.55 – 3.46 (m, 1H, -CH-CH 2b -O), 2.90 – 2.84 (m, 1H, H-6), 2.26 – 2.12 (m, 1H, H-6), 1.47 (d, J = 7.4 Hz, 3H, -N-CH-CH 3 ), 1.44 (s, 9H, -COOC(CH 3 ) 3 ). 13 C NMR (100 MHz, CDCl3 ) δ 173.37, 169.82, 168.69, 166.87, 137.75, 137.09, 134.94, 129.84, 128.40, 128.40, 127.74, 127.69, 127.69, 110.67, 82.41, 73.36, 72.00, 63.31, 54.99, 52.97, 51.63, 48.86, 40.08, 36.48, 27.93, 27.93, 27.93, 15.97。

[0143] Compound 11i: Colorless oil (51%). 1 H NMR (400 MHz, CDCl 3 ) δ 7.31 (m, 4H, Ar-H), 7.28 (m, 1H, Ar-H), 7.28 (s, 1H, H-3), 5.86 (s, 1H, H-7), 5.08 – 4.91 (m, 3H, overlap, H-10, -N-CH-CH 3 ), 3.77 (s, 3H, -COOCH 3 ), 3.73 (d, J J = 11.3 Hz, 2H, -CH 2 -Ph), 3.70 – 3.62 (m, 1H, -CH-NH 2 ), 3.62 – 3.47 (m, 2H, overlap, H-9, H-5), 2.94 – 2.91 (m, 1H, H-6), 2.89 – 2.82 (m, 1H, -S-CH 2a -CH), 2.73 – 2.68 (m, 1H, -S-CH 2b -CH), 2.26–2.13 (m, 1H, H-6), 1.47 (d, J J = 7.4 Hz, 3H, -CH-CH 3 ), 1.44 (s, 9H, -COOC(CH 3 ) 3 )。

[0144] Compound 11j: Colorless oil (53%). 1 H NMR (400 MHz, CDCl 3) δ 7.37 – 7.26 (m, 5H, Ar-H), 7.25 (s, 1H, H-3), 5.84 (s, 1H, H-7), 5.06 – 4.86 (m, 3H, overlap, H-10, -N-CH), 4.57 (d, J J = 11.7 Hz, 1H, -CH 2a -Ph), 4.42 (d, J J = 11.7 Hz, 1H, -CH 2b -Ph), 4.01 – 3.99 (m, 1H, -O-CH-CH 3 ), 3.76 (s, 3H, -COOCH 3 ), 3.62 (d, J J = 10.8 Hz, 1H, -CH-NH 2 ), 3.55 – 3.47 (m, 1H, H-9), 3.45 – 3.44 (m, 1H, H-5), 2.88 – 2.82 (m, 1H, H-6), 2.25 – 2.08 (m, 1H, H-6), 1.46 (d, J J = 7.4 Hz, 3H, -N-CH-CH 3 ), 1.43 (s, 9H, -COOC(CH 3 ) 3 ), 1.32 – 1.30 (m, 3H, -O-CH-CH 3 ). 13 C NMR(100 MHz, CDCl 3 ) δ 173.85, 169.83, 168.68, 166.87, 138.28, 137.11, 134.93, 130.13, 128.31, 28.31, 127.58, 127.58, 110.65, 82.40, 75.81, 70.96, 63.24, 59.59, 52.97, 51.62, 48.83, 40.07, 36.45, 31.44, 27.92, 27.92, 27.92, 16.50, 15.95。

[0145] Compound 11k: Colorless oil (42%), 1 H NMR (400 MHz, CDCl 3) δ 8.62 (s, 1H, -NH in indole), 7.62 (d, J J = 7.2 Hz, 1H, Ar-H), 7.37 – 7.30 (m, 1H, Ar-H), 7.28(s, 1H, H-3), 7.17 – 7.06 (m, 2H, Ar-H), 6.94 (d, J J = 2.2 Hz, 1H, -CH in pyrrole ring), 5.72 (s, 1H, H-7), 5.19 (d, J J = 13.1 Hz, 1H, H-10), 5.09 (q, J J = 7.5 Hz, 1H, -N-CH), 4.62 (d, J J = 12.8 Hz, 1H, H-10), 3.89 (t, J J = 7.0 Hz,1H, -CH-NH 2 ), 3.78 (s, 3H, -COOCH 3 ), 3.23 – 3.08 (m, 2H, overlap, H-9, H-5),3.07 – 2.98 (m, 1H, -CH 2a -CH), 2.76 – 2.70 (m, 1H, H-6), 2.62 (d, J J = 10.8 Hz,1H, -CH 2b -CH), 2.07 (m, 1H, H-6), 1.50 (s, 9H, -COOC(CH 3 ) 3 ), 1.48 (s, 3H, -N-CH-CH 3 ). 13 C NMR (100 MHz, CDCl 3 ) δ 175.60, 170.87, 169.27, 166.93, 137.56,136.31, 134.34, 130.60, 127.33, 123.07, 121.86, 119.39, 118.76, 111.43,111.03, 110.97, 83.03, 63.09, 55.37, 52.41, 51.66, 46.98, 39.54, 36.34,31.82, 28.00, 28.00, 28.00, 16.00。

[0146] Table 5 Compounds 11a - 11k

[0147]

[0148] Example 6 Synthesis of Compounds 11a - 11k

[0149] Dissolve one of the compounds 9a - 9k in Example 3 (0.34 mmol) and trifluoroacetic acid (6.4 mmol) in dichloromethane. After reacting at room temperature for 0.5 h, add ethyl acetate and saturated brine (volume ratio 1:1) for extraction to obtain the organic layer. Dry it with anhydrous sodium sulfate at room temperature for 12 h and then concentrate. Use column chromatography to separate and purify the concentrate to obtain one of the pure products 12a - 12k respectively;

[0150] Among them: 42a is used for synthesizing 12a, 42b is used for synthesizing 12b, 42c is used for synthesizing 12c, 42d is used for synthesizing 12d, 42f is used for synthesizing 12f, 42e is used for synthesizing 12e, 42g is used for synthesizing 12g, 42h is used for synthesizing 12h, 42i is used for synthesizing 12i, 42j is used for synthesizing 12j, and 42k is used for synthesizing 12k.

[0151] The structures of compounds 12a - 12k are shown in Table 6; the appearance and NMR spectral data are as follows:

[0152] Compound 12a: Colorless oil (65%), 1 H NMR (400 MHz, CDCl 3 ) δ 7.26 – 7.18 (m, 4H, Ar - H), 7.13 – 7.06 (m, 2H, Ar - H, H - 3), 5.72 (s, 1H, H - 7), 5.27 (dd, J = 11.1, 5.4 Hz, 1H, -N - CH), 4.77 (q, J = 13.3 Hz, 2H, H - 10), 3.75 (s, 3H, -COOCH 3 ), 3.56 (d, J = 10.6 Hz, 1H, H - 9), 3.48 – 3.33 (m, 4H, overlap, -CH 2 -Ph, -CH 2 -NH 2 ), 2.98 (dd, J = 14.3, 11.3 Hz, 1H, H - 5), 2.75 (dd, J= 16.2, 8.4 Hz, 1H, H-6), 1.89 (d, J = 2.2 Hz, 1H, H-6), 1.45 (s, 9H, -COOC(CH 3 ) 3 ). 13 C NMR (100 MHz, CDCl 3 ) δ 173.82, 168.84, 168.54, 166.79, 136.89, 136.08, 135.32, 130.11, 128.99, 128.99, 128.53, 128.53, 126.94, 110.53, 82.83, 62.89, 57.74, 51.63, 48.54, 43.92, 39.61, 36.35, 36.25, 27.95, 27.95, 27.95.

[0153] Compound 12b: Colorless oil (50%), 1 H NMR (400 MHz, CDCl 3 ) δ 7.25 – 7.15 (m, 4H, Ar-H), 7.14 – 7.05 (m, 2H, overlap, Ar-H, H-3), 5.71 (s, 1H, H-7), 5.30 - 5.26 (m, 1H, -N-CH), 4.80 - 4.69 (m, 2H, H-10), 3.74 (s, 3H, -COOCH 3 ), 3.63 – 3.50 (m, 2H, H-9, -CH-NH 2 ), 3.50 – 3.32 (m, 2H, overlap, H-5, -CH 2a -Ph), 3.02 - 2.95 (m, 1H, -CH 2b -Ph), 2.78 – 2.72 (m, 1H, H-6), 2.06 – 1.92 (m, 1H, H-6), 1.46 (s, 9H, -COOC(CH 3 ) 3 ), 1.37 – 1.33 (m, 3H, -CH-CH 3 ).

[0154] Compound 12c: Colorless oil (50%), 1 H NMR (400 MHz, CDCl 3) δ 7.24 – 7.16 (m, 4H, Ar-H), 7.13 – 7.08 (m, 2H, Ar-H, H-3), 5.73 (s, 1H, H-7), 5.28 – 5.24 (m, 1H, -N-CH), 4.81 (d, J J = 13.4 Hz, 1H, H-10), 4.72 (d, J J = 13.4 Hz, 1H, H-10), 3.75 (s, 3H, -COOCH 3 ), 3.55 (d, J J = 10.7 Hz, 1H, -CH-NH 2 ), 3.46 – 3.36 (m, 2H, overlap, H-9, -CH 2a -Ph), 3.30 (d, J J = 4.9 Hz, 1H, -CH 2b -Ph), 3.02 - 2.96 (m, 1H, H-5), 2.78 – 2.72 (m, 1H, H-6), 2.11 – 1.99 (m, 1H, -CH-CH 3 ), 1.94 – 1.80 (m, 1H, H-6), 1.45 (s, 9H, -COOC(CH 3 ) 3 ), 0.98 (d, J J = 6.9 Hz, 3H, -CH-CH 3 ), 0.90 (d, J J = 6.8 Hz, 3H, -CH-CH 3 ).

[0155] Compound 12d: colorless oil (50%), 1 H NMR (400 MHz, CDCl 3 ) δ 7.29 – 7.24 (m, 1H, Ar-H), 7.21 – 7.07 (m, 5H, Ar-H, H-3), 5.71 (s, 1H, H-7), 5.27 (dd, J J = 11.1, 5.4 Hz, 1H, -N-CH), 4.86 – 4.55 (m, 2H, H-10), 3.75 (s, 3H, -COOCH 3 ), 3.57 – 3.32 (m, 4H, -N-CH-CH2 -Ph, H-9, -CH-NH 2 ), 3.06 – 2.94 (m, 1H, H-5), 2.83 – 2.66 (m, 1H, H-6), 1.91 – 1.82 (m, 1H, H-6), 1.74 (d, J J = 6.3 Hz, 2H, -CH 2 -CH-(CH 3 ) 2 ), 1.61 – 1.54 (m, 1H, -CH-(CH 3 ) 2 ), 1.46 (s, 9H, -COOC(CH 3 ) 3 ), 0.93(t, J J = 7.1 Hz, 6H, -CH-(CH 3 ) 2 ). 13 C NMR (100 MHz, CDCl 3 ) δ 176.10, 168.87, 168.52, 166.81, 137.04, 136.08, 135.37, 129.81, 129.81, 128.98, 128.98, 128.53, 126.95, 110.52, 82.82, 62.87, 57.78, 52.91, 51.62, 48.58, 44.01, 39.59, 36.35, 36.30, 27.95, 27.95, 27.95, 24.77, 22.99, 21.88。

[0156] Compound 12e: Colorless oil (88%), 1 1H NMR (400 MHz, CDCl 3 ) δ 7.25 – 7.17 (m, 4H, Ar-H), 7.13 – 7.05 (m, 2H, Ar-H, H-3), 5.72 (s, 1H, H-7), 5.27 (dd, J J =11.2, 5.4 Hz, 1H, -N-CH), 4.79 – 4.70 (m, 2H, H-10), 3.75 (s, 3H, -COOCH 3 ), 3.63 – 3.54 (m, 2H, -CH-NH 2, -CH 2a-Ph), 3.47 – 3.27 (m, 2H, H-9, -CH 2b -Ph),3.02 - 2.95 (m, 1H, H-5), 2.79 – 2.73 (m, 1H, H-6), 2.63 (t, J = 7.4 Hz, 2H,-S-CH 2 ), 2.09 (s, 3H, -S-CH 3 ), 2.07 – 1.98 (m, 1H, -S-CH 2 -CH 2a ), 1.93 – 1.85(m, 1H, H-6), 1.83 – 1.73 (m, 1H, -S-CH 2 -CH 2b ), 1.46 (s, 9H, -COOC(CH 3 ) 3 )

[0157] Compound 12f: colorless oil (12%), 1 H NMR (400 MHz, CDCl 3 ) δ 7.32 – 7.25 (m, 3H,Ar-H), 7.18 (m, 6H, Ar-H), 7.11 (d, J = 1.7 Hz, 1H, Ar-H), 7.09 (s, 1H, H-3),5.64 (s, 1H, H-7), 5.29 (dd, J = 11.1, 5.5 Hz, 1H, -N-CH), 4.80 (d, J = 13.4Hz, 1H, H-10), 4.70 (d, J = 13.4 Hz, 1H, H-10), 3.75 (s, 3H, -COOCH 3 ), 3.72(s, 1H, -CH-NH 2 ), 3.40 (d, J = 5.5 Hz, 2H, -N-CH-CH 2 -Ph), 3.38 – 3.33 (m, 1H,H-9), 3.08 (dd, J = 13.6, 5.7 Hz, 1H, -CH 2a -CH-NH 2 ), 2.98 (dd, J= 14.4, 11.1Hz, 1H, H-5), 2.88 (dd, J = 13.6, 7.6 Hz, 1H, -CH 2b -CH-NH 2 ), 2.79 – 2.64 (m,1H, H-6), 1.90 – 1.74 (m, 1H, H-6), 1.46 (s, 9H, -COOC(CH 3 ) 3 ). 13 C NMR (100MHz, CDCl 3 ) δ 174.61, 168.89, 168.57, 166.83, 137.19, 136.87, 136.07, 135.35,130.19, 129.34, 129.34, 128.99, 128.99, 128.57, 128.57, 128.54, 128.54,126.96, 126.80, 110.48, 82.84, 63.01, 57.67, 55.86, 51.64, 48.39, 41.11,39.54, 36.42, 36.29, 27.97, 27.97, 27.97。

[0158] Compound 12g: Colorless oil (88%) 1 H NMR (400 MHz, CDCl 3 ) δ 7.25 – 7.16 (m, 4H,Ar-H), 7.11- 7.09 (m, 4H, Ar-H, H-3), 6.88 – 6.77 (m, 2H, Ar-H), 5.65 (s, 1H,H-7), 5.27 (dd, J = 11.1, 5.5 Hz, 1H, -N-CH), 4.82 – 4.69 (m, 2H, H-10), 3.77(s, 3H, -OCH 3 ), 3.75 (s, 3H, -COOCH 3 ), 3.44 (t, J = 7.4 Hz, 1H, -CH-NH 2 ), 3.42– 3.32 (m, 2H, -N-CH-CH 2 -Ph), 3.04 – 2.98 (m, 2H, -CH 2a -CH-NH2 , H-5), 2.86 –2.81 (m, 1H, -CH 2b -CH-NH 2 ), 2.76 – 2.70 (m, 1H, H-6), 1.90 – 1.79 (m, 1H, H-6), 1.45 (s, 9H, -COOC(CH 3 ) 3 )。

[0159] Compound 12h: Colorless oil (12%), 1 H NMR (400 MHz, CDCl 3 ) δ 7.43 – 7.22 (m,7H, Ar-H), 7.20 – 7.13 (m, 2H, Ar-H), 7.11 (s, 1H, H-3), 7.09 (s, 1H, Ar-H),5.67 (s, 1H, H-7), 5.28 (dd, J = 11.1, 5.4 Hz, 1H, -N-CH), 4.91 – 4.68 (m,2H, H-10), 4.63 – 4.43 (m, 2H, -O-CH 2 -Ph), 3.75 (s, 3H, -COOCH 3 ), 3.73 – 3.69(m, 1H, -CH-COOCH 2 ), 3.67 – 3.66 (m, 1H, -O-CH 2a -CH), 3.50 – 3.47 (m, 1H, H-9), 3.42 – 3.31 (m, 2H, -N-CH-CH 2 -Ph), 3.01 – 2.98 (m, 1H, -O-CH 2b -CH), 2.73 –2.67 (m, 1H, H-6), 2.02 – 2.01 (m, 1H, H-6), 1.45 (s, 1H, -COOC(CH 3 ) 3 )。

[0160] Compound 12i: Colorless oil (51%), 1 H NMR (400 MHz, CDCl 3 ) δ 7.36 – 7.28 (m,4H, Ar-H), 7.25 – 7.16 (m, 5H, Ar-H), 7.10 (d,J = 6.5 Hz, 2H, Ar-H, H-3), 5.69 (s, 1H, H-7), 5.28 (dd, J = 11.1, 5.4 Hz, 1H, -N-CH), 4.74 (q, J = 13.4Hz, 2H, H-10), 3.76 (s, 3H, -COOCH 3 ), 3.73 (s, 2H, -S-CH 2 -Ph), 3.59 (dd, J =7.6, 4.6 Hz, 1H, -CH-NH 2 ), 3.51 – 3.48 (m, 1H, H-9, N-CH-CH 2a -Ph), 3.44 – 3.36(m, 2H, H-9, -N-CH-CH 2b -Ph), 3.01 – 2.95 (m, 1H, H-5), 2.85 – 2.81 (m, 1H, -S-CH 2a -CH), 2.77 – 2.71 (m, 1H, H-6), 2.68 – 2.63 (m, 1H, -S-CH 2b -CH), 1.89 –1.83 (m, 1H, H-6), 1.45 (s, 9H, -COOC(CH 3 ) 3 )。

[0161] Compound 12j: colorless oil (53%), 1 H NMR (400 MHz, CDCl 3 ) δ 7.39 – 7.27 (m,3H, Ar-H), 7.23 – 7.08 (m, 8H, Ar-H, H-3), 5.68 (s, 1H, H-7), 5.25 (dd, J =11.1, 5.4 Hz, 1H, -N-CH), 4.76 – 4.70 (m, 2H, H-10), 4.55 (t, J = 10.4 Hz,1H, -O-CH 2a ), 4.12 – 4.33 (m, 1H, -O-CH 2b ), 3.98 (dd, J = 6.3, 3.6 Hz, 1H, -CH-NH2 ), 3.74 (s, 3H, -COOCH 3 ), 3.50 (d, J = 10.5 Hz, 1H, -CH-NH 2 ), 3.46 – 3.21 (m, 3H, overlap, H-9, -N-CH-CH 2 -Ph), 3.01 – 2.94 (m, 1H, overlap, H-5), 2.71 – 2.65 (m, 1H, H-6), 1.88 – 1.78 (m, 1H, H-6), 1.12 (s, 9H, -COOC(CH 3 ) 3 ), 1.35 – 1.29 (m, 3H, -CH-CH 3 )。

[0162] Compound 12k: Colorless oil (42%), 1 H NMR (400 MHz, CDCl 3 ) δ 8.51 (s, 1H, -NHin indole), 7.60 (d, J = 7.5 Hz, 1H, Ar-H), 7.30 (d, J = 7.7 Hz, 2H, Ar-H), 7.23 – 7.09 (m, 7H, Ar-H), 7.06 (s, 1H, H-3), 6.95 (d, J = 2.1 Hz, 1H, -CH inpyrrole ring), 5.56 (s, 1H, H-7), 5.42 (dd, J = 11.2, 5.6 Hz, 1H, -N-CH), 5.00 (d, J = 12.9 Hz, 1H, H-10), 4.48 (d, J = 12.9 Hz, 1H, H-10), 3.87 (t, J = 6.9 Hz, 1H, -CH-NH 2 ), 3.77 (s, 3H, -COOCH 3 ), 3.45 – 3.40 (m, 1H, H-9), 3.14(d, J = 6.9 Hz, 2H, -CH 2-Ph), 3.01 – 2.93 (m, 2H, -CH 2 -CH-NH 2 ), 2.62 – 2.59(m, 1H, H-5), 2.57 – 2.51 (m, 1H, H-6), 1.68 – 1.59 (m, 1H, H-6), 1.50 (s,9H, -COOC(CH 3 ) 3 ). 13 C NMR (100 MHz, CDCl 3 ) δ 175.34, 169.65, 169.01, 166.84,137.24, 136.31, 135.91, 134.89, 130.12, 128.89, 128.89, 128.52, 128.52,127.34, 126.98, 123.08, 121.89, 119.41, 118.77, 111.42, 111.01, 110.84,83.37, 62.99, 57.13, 55.26, 51.66, 46.96, 38.94, 36.32, 36.23, 31.59, 28.02,28.02, 28.02。

[0163] Table 6 Compounds 12a - 12k

[0164]

[0165] To demonstrate the advantages of the technical solutions provided by this application, the following are examples of the technical solutions provided by this application.

[0166] Experimental Example 1 Cell activity exploration of Compound 9a.

[0167] (1) Cultivation of HT22 cells

[0168] HT22 cells were resuscitated in a 37°C water bath for 3 minutes, placed in a 15 mL centrifuge tube, and centrifuged at room temperature with 10 mL of high - glucose medium containing 10% fetal bovine serum and 1% double antibody (penicillin - streptomycin mixture 100×), i.e., complete medium. After removing the supernatant, the cells were cultured in the complete medium in a 37°C, 5% carbon dioxide incubator. When the cells grew to about 80%, they could be passaged.

[0169] (2) Oxygen - glucose deprivation / reperfusion (OGD / R) - induced HT22 injury model

[0170] 96-well plates were seeded with HT22 cells at a density of 5000 cells per well. After 12 hours, the complete medium was aspirated, and serum-free and sugar-free medium was added. The cells were cultured under hypoxia for 12 hours in a triple-gas incubator. After reoxygenation, the model group was added with complete medium, and the drug treatment group was added with drug complete medium solutions at different concentrations. The cells were cultured in an incubator at 37 °C and 5% CO 2 in an incubator for 24 hours, and MTT was added to detect cell viability.

[0171] (3) Exploration of the optimal protective activity concentration of compound 9a

[0172] In the preliminary screening of cell viability, it was found that compound 9a had good neuroprotective activity at a concentration of 10 μM and showed concentration dependence. To explore the relationship between the specific concentration of 9a and its activity, 9a at concentrations of 1, 5, 10, and 20 μM was set, and the cell survival rate was detected in the OGD / R model. The results are as Figure 4 shown. The cell survival rate of the model group was 58%. After treatment with 9a at concentrations of 1, 5, 10, and 20 μM, the cell survival rates were 71%, 93%, 85%, and 61% respectively. The activity results showed that 9a had the best cell protection effect at 5 μM, and the cell survival rate increased by 35%.

[0173] (4) Determination of the content of lactate dehydrogenase (LDH)

[0174] To determine the changes in the LDH content of cells in each group, the groups were divided and measured according to the instructions of the cell LDH detection kit (Bestbio, Shanghai, China). HT22 cells were seeded in 96-well plates at a density of 5000 cells per well. After 12 hours of culture, the complete medium was aspirated, and serum-free and sugar-free medium was added. The cells were cultured under hypoxia for 12 hours in a triple-gas incubator. After adding drug 9a and reoxygenating for 24 hours, the LDH content was measured using the kit. From the observation of cell morphology, as Figure 5 shown in A of it, it can be seen that different from the normal group cells, most of the HT22 cells in OGD / R became round, indicating that the cells were damaged to a certain extent due to the lack of oxygen and sugar. Under the treatment of the compound, the cells restored the extended morphology and presented a normal state. At the same time, the LDH content was detected, and the results are as Figure 5 shown in B of it. It can be seen that consistent with the morphological observation results, the LDH release amount of normal group cells was 111%, while the LDH level in the cell supernatant of the OGD / R group increased significantly (239%), about twice that of the normal cell group. Treatments with 9a at concentrations of 5 and 10 μM had significant reducing effects, making the LDH release amounts 172% and 136% respectively. It can be seen from the results that compound 9a can restore the damage of OGD / R-induced neuronal cells.

[0175] (5) Determination of the content of reactive oxygen species (ROS)

[0176] To determine the changes in the ROS content of cells in each group, the cells were grouped and measured according to the instructions of the ROS detection kit (Meilunbio, Dalian, China). HT22 cells were seeded in a 12-well plate at a density of 100,000 cells per well. After culturing for 12 hours, the complete medium was aspirated, and serum-free and sugar-free medium was added. The cells were cultured under hypoxia for 12 hours in a triple-gas incubator. After adding drug 9a and reoxygenating for 24 hours, an inverted fluorescence microscope was used to observe and capture the ROS fluorescence images, referring to Figure 6 A in Figure 6 B in showed that the fluorescence level of the normal group of HT22 cells was 0.86. It could be seen that different from the normal group of cells, the ROS level of HT22 cells under OGD / R was significantly increased after stimulation, and the fluorescence level was 3.97, which was about 4.6 times that of the normal group. After treatment with 5 and 10 μM of 9a, the ROS level induced by OGD / R was significantly decreased and was close to that of the normal cell group at 5 μM.

Claims

1. A diamino acid-genipin derivative, characterized in that: It has the general structural formula of formula 1 or formula 2: ； Wherein: Formula 1 is selected from the following specific structural formulas: ； Formula 2 is selected from the following specific structural formulas: 。 2. The method for preparing the diamino acid-genipin derivative according to claim 1, characterized in that: The steps are as follows: When the diamino acid-genipin derivative has the general structural formula of formula 1: using genipin as a starting material, an intermediate 1 is obtained by etherification reaction with tert-butyldimethylsilyl chloride, intermediate 1 is obtained by oxidation reaction to obtain intermediate 2, intermediate 2 and amino acid tert-butyl ester hydrochloride are subjected to amination reaction to obtain intermediate 3, intermediate 3 is subjected to esterification reaction with amino acid compound, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride to produce formula 1; The synthetic route of formula 1 and its products are as follows: ； When the diamino acid-genipin derivative has the general structural formula of Formula 2: Formula 1 is deaminated with trifluoroacetic acid to obtain Formula 2; The synthetic route and its products are shown below:

3. The method for preparing the bis-amino acid-genipin derivative according to claim 2, characterized in that: The oxidation reaction is a Dess-Martin periodinane oxidation reaction.

4. The method for preparing the bis-amino acid-genipin derivative according to claim 2, characterized in that: The amino acid tert-butyl ester hydrochloride is one of glycine tert-butyl ester hydrochloride, alanine tert-butyl ester hydrochloride, and phenylalanine tert-butyl ester hydrochloride or any combination thereof.

5. The method for preparing the bis-amino acid-genipin derivative according to claim 2, characterized in that: The amino acid compound is one of N-(tert-butoxycarbonyl)-L-tryptophan, N-(tert-butoxycarbonyl)-L-methionine, N-(tert-butoxycarbonyl)-O-benzyl-L-threonine, N-(tert-butoxycarbonyl)-L-isoleucine, N-(tert-butoxycarbonyl)-D-alanine, N-(tert-butoxycarbonyl)-O-benzyl-L-serine, N-(tert-butoxycarbonyl)-S-benzyl-L-cysteine, N-(tert-butoxycarbonyl)-L-valine, N-(tert-butoxycarbonyl)-L-phenylalanine, N-(tert-butoxycarbonyl)glycine, and N-tert-butoxycarbonyl-4-methoxy-L-phenylalanine, or any combination thereof.

6. Use of the diamino acid-genipin derivative according to claim 1 in the preparation of a neuroprotective drug for treating ischemia-reperfusion injury.

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