A method for the synthesis of rosmarinic acid and analogs thereof

Abstract

The application relates to a synthesis method of rosmarinic acid and analogues thereof. The disclosed synthesis method of rosmarinic acid and analogues thereof comprises: a Knoevenagel condensation reaction of Danshensu or a hydroxyl-substituted aryl lactic acid and a hydroxyl-substituted benzaldehyde through Meldrum acid mediation to obtain (+)-rosmarinic acid and analogues thereof, and the total yield is between 54% and 87%. The application has the characteristics of simple and easily-obtained raw materials, no protective group participation, short synthesis route, high atom economy and step economy, and large-scale industrial production advantages.

Description

Technical Field

[0001] This invention belongs to the field of medicinal chemistry technology and relates to a method for synthesizing rosmarinic acid and its analogues. Background Technology

[0002] (+)-Rosemary acid is a condensed phenolic acid formed by the esterification of caffeic acid with (+)-3,4-dihydroxyphenyllactic acid (d-tanshinone). It was first isolated from rosemary by Scarpati and Oriente in 1958 (RIC Sci 1958, 28, 2329-2333.).

[0003] Existing technology reports that (+)-rosmarinic acid and its naturally occurring esters, such as methyl rosmarinic acid (Chin. Chem. Lett. 2000, 11, 997-1000.), ethyl rosmarinic acid (Chin. Chem. Lett. 2000, 11, 997-1000.), isopropyl rosmarinic acid (Chin. Chem. Lett. 2000, 11, 997-1000.), and butyl rosmarinic acid (Chin. Chem. Lett. 2000, 11, 997-1000.), have been found in various medicinal plants (Phytochemistry 2003, 62, 121-125.), and possess various biological and pharmacological activities, such as antioxidant activity (Archives of Pharmacal Research 2004, 27, 173-176.; Journal of Agricultural and Food Chemistry). 2010, 58, 2869-2876.; Pharmaceutical Research 2013, 30, 1979-1989.; Journal of Agricultural and Food Chemistry 2010, 58, 5679-5684.), antibacterial activity (Journal of Food Protection 2013, 76, 1539-1548.; Chemistry of Natural Compounds 2014, 49, 1023-1027.; Journal of Food Protection 2018, 81, 598-605.), anti-HBV activity (Chinese Pharmaceutical Journal 2009, 44, 170-175.), anti-allergic activity (Biosci Biotech Bioch 2015, 79, 1178-1182.), and aortic dilation (European Journal of Pharmacology 2015, 766, 9-15.).In addition, it can inhibit various proteins (such as lipoxygenase (Chem Biodivers 2005, 2, 104-111.), angiotensin-converting enzyme (ACE) (Phytomedicine 2008, 15, 386-388.), tyrosinase / α-glucosidase (Food Chem 2011, 129, 884-889.), IL-2 (Chemical Biology & Drug Design 2012, 79, 290-299.), metalloproteinases (European Journal of Medicinal Chemistry 2013, 62, 148-157.), and carbonic anhydrase II (ChemBiodivers 2017, 14, e1700024.)) and various diseases, including hyperuricemia (Molecules 2015, 20, 17848-17859.), macrophage-mediated inflammatory lung diseases (European Journal). (of Pharmacology 2018, 824, 17-23.) and diabetes (Chem Biodivers 2016, 13, 596-601.).

[0004] Despite the widespread interest in the biological and pharmaceutical activities of these compounds, their synthesis methods have so far been limited by Ellis's original biosynthetic route (Biochem J 1970, 118, 291-297; Planta 1977, 137, 287-291). Summary of the Invention

[0005] To address the deficiencies or shortcomings of existing technologies, this invention discloses a method for synthesizing rosmarinic acid. The structural formula of the rosmarinic acid is shown in (I):

[0006]

[0007] In formula (I), R is selected from hydrogen. Selected from phenyl, m = n = 2;

[0008] The method for synthesizing rosmarinic acid includes:

[0009] Step 1: Tanshinone reacts with McMurray acid in an organic solvent to generate an intermediate;

[0010] Step 2: The obtained intermediate is reacted with protocatechuic aldehyde under the catalysis of an organic base to obtain rosmarinic acid.

[0011] The present invention also provides a method for synthesizing the above-mentioned rosmarinic acid analog, wherein the structural formula of the analog is shown in (I), and R in formula (I) is selected from alkyl, cycloalkyl, heteroalkyl, heterocycloyl, aryl, aralkyl, heteroaryl or heteroarylalkyl; The derivatives are selected from phenyl, aryl, aralkyl, or heteroaryl groups; m and n are selected from 0 to 5; the method for synthesizing the rosmarinic acid analogue includes:

[0012] Step 1: Hydroxyl-substituted phenyllactic acid compounds react with McMurray acid in an organic solvent to generate an intermediate;

[0013] Step 2: The obtained intermediate is reacted with a hydroxyl-substituted aromatic aldehyde under the catalysis of an organic base to obtain a rosmarinic acid analog.

[0014] An alternative approach is to allow the intermediate in the above method to react directly with protocatechuic aldehyde without separation.

[0015] Alternatively, the organic solvent is selected from one or a mixture of two or more of 1,4-dioxane, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, toluene, tetrahydrofuran, acetonitrile, and dimethyl sulfoxide.

[0016] An alternative approach is to set the reaction temperature in step 1 to 45℃~110℃.

[0017] An alternative is to have a reaction time of 1 to 5 hours in step 1.

[0018] An alternative is that the molar ratio of tanshinone or hydroxylated phenyl lactic acid compound to McMurray acid is 1:(1-5).

[0019] An alternative is that the organic base includes a first type of organic base and a second type of organic base; the first type of organic base is selected from pyridine or 4-dimethylaminopyridine; the second type of organic base is selected from piperidine, morpholine, N-methylpiperazine, tetrahydropyrrole or dimethylpyridineamine.

[0020] An alternative is that the molar ratio of the first type of organic base, tanshinone or hydroxylated phenyl lactic acid compound, and the second type of organic base is 1:(1-2):(0.05-0.5).

[0021] An alternative is to set the reaction temperature in step 2 to 50℃~100℃.

[0022] An alternative is to have a reaction time of 12 to 24 hours in step 2.

[0023] Existing chemical synthesis methods for rosmarinic acid (European Journal of Medicinal Chemistry 2013, 62, 148-157; Angewandte Chemie International Edition in English 1991, 30, 130-147; Synthesis 1996, 6, 755-762; Can J Chem 1997, 75, 1783-1794) all use caffeic acid and tanshinone, both protected by phenolic hydroxyl groups, as raw materials. This is because: (i) the catechol group is easily decomposed under pH changes and oxidative conditions and is relatively unstable; (ii) the phenolic hydroxyl and carboxyl groups of tanshinone interfere with the esterification process. This protecting group strategy leads to an increase in the number of synthetic routes for this type of compound, resulting in low overall yields and high costs. The method for synthesizing rosmarinic acid and its analogues disclosed in this invention includes: tanshinone or hydroxylated aryl lactic acid and hydroxylated benzaldehyde undergoing a Meldrum acid-mediated Knoevenagel condensation reaction to obtain (+)-rosmarinic acid and its analogues, with a total yield between 54% and 87%.

[0024] The method for synthesizing rosmarinic acid and its analogues in this invention uses readily available raw materials, requires no protecting groups, has a short synthetic route, and exhibits high atom and step economy.

[0025] The synthesis method of this invention allows the two-step reaction to be carried out in the same reaction equipment, eliminating the need for purification of intermediates, simplifying the operation and control of the process, and reducing production costs.

[0026] The synthesis method of this invention has high product yield and purity, and can be used for large-scale industrial production.

[0027] Based on existing reports on the activity of rosmarinic acid, those skilled in the art can infer that the compounds of the present invention possess a variety of biological and pharmacological activities and have application value in drug development, such as, but not limited to, antioxidant activity, antibacterial activity, anti-HBV activity, anti-allergic activity, and aortic dilation, inhibition of various proteins, angiotensin-converting enzyme, tyrosinase / α-glucosidase, IL-2, metalloproteinases and carbonic anhydrase II, and treatment of various diseases, including hyperuricemia, macrophage-mediated inflammatory lung diseases and diabetes.

[0028] For example, the inventors used a potent VEGF receptor inhibitor (PTK787) to induce a zebrafish model of insufficient intersegmental angiogenesis, simulating the pathological state of insufficient angiogenesis in disease, and studied the efficacy of rosmarinic acid and its analogues in promoting angiogenesis. Comparatively, the rosmarinic acid analogues of this invention showed better efficacy than rosmarinic acid and the positive control drug Danshen injection; some compounds significantly promoted the growth of PTK787-inhibited intersegmental vessels in zebrafish without significant toxic side effects.

[0029] It can be confirmed that the rosmarinic acid, related analogues and pharmaceutically acceptable salts involved in this invention are used in the preparation of remedies for treating acute or chronic diseases accompanied by insufficient angiogenesis.

[0030] The acute or chronic diseases associated with insufficient angiogenesis include cardiovascular diseases, cerebrovascular diseases, chronic ischemic diseases of the limbs caused by peripheral vascular occlusion, trauma, slow fracture healing, psoriasis, ischemic bowel diseases, and aging.

[0031] The cardiovascular diseases mentioned include acute or chronic coronary atherosclerotic heart disease, rheumatic heart disease, hypertensive heart disease, pulmonary heart disease, infectious heart disease, endocrine heart disease, hematologic heart disease, valvular heart disease, myocardial ischemia, or insufficient collateral circulation compensation.

[0032] The cerebrovascular diseases mentioned are transient ischemic attacks, cerebral infarction, cerebral steal syndrome, vertebrobasilar insufficiency, or vascular dementia.

[0033] The chronic ischemic limb disease caused by peripheral vascular occlusion includes arteriosclerosis obliterans, thromboangiitis obliterans, diabetic foot, Raynaud's disease or Raynaud's syndrome, or ulcers caused by stasis dermatitis. Attached Figure Description

[0034] Figure 1 The toxic effects of rosmarinic acid and its analogues on zebrafish are described in this invention.

[0035] Figure 2 The image shows the effects of rosmarinic acid and its analogues on the blood vessels of a PTK787-induced zebrafish model of insufficient intersegmental angiogenesis. A: Statistical graphs of data for compounds 1a, 1c, 1d, 1e, and 1g; B: Statistical graphs of data for compounds 5a and 5b; C: Statistical graphs of data for compounds 6a, 6b, 6d, 6e, and 6f; D and E: Representative images of zebrafish experiments for compounds 1a, 1c, 1d, 1e, 1g, 5a, and 5b. Detailed Implementation

[0036] Unless otherwise stated, the terminology used herein is understood in accordance with the conventional understanding of those skilled in the art.

[0037] The synthetic route for rosmarinic acid and its analogues of the present invention is as follows:

[0038]

[0039] To further improve the yield, based on the technical concept of this invention, those skilled in the art can optimize the relevant reaction conditions, including but not limited to: the reaction temperature of each step, the organic solvent and amount used in the reaction, the ratio between reactants, and the type and amount of organic base.

[0040] Based on this approach, the present invention provides relevant condition examples:

[0041] In the preparation reaction of rosmarinic acid and its analogues: the organic solvent is selected from one or more combinations of 1,4-dioxane, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, toluene, tetrahydrofuran, acetonitrile and dimethyl sulfoxide, with 1,4-dioxane being preferred as the solvent.

[0042] The reaction temperature of the hydroxylated phenyl lactic acid compound with McMurray acid is between 45°C and 110°C, preferably between 90°C and 100°C.

[0043] The reaction time between the hydroxylated phenyllactic acid compound and McMurray acid is between 1 and 5 hours, preferably 3 to 4 hours.

[0044] The ratio of the hydroxylated phenyl lactic acid compound to McMurray acid is 1:(1-5), with 1:1.5 being preferred.

[0045] The organic base in the reaction includes both a first type of organic base and a second type of organic base. The first type of organic base is selected from pyridine and 4-dimethylaminopyridine; the second type of organic base is selected from piperidine, morpholine, N-methylpiperazine, tetrahydropyrrole, and dimethylpyridineamine. Pyridine is preferred as the first type of organic base, and morpholine is preferred as the second type of organic base.

[0046] The material ratio of the first type of organic base to the hydroxyl-substituted phenyllactic acid compound and the second type of organic base is between 1:(1~2):(0.05~0.5), and the preferred material ratio of the first type of organic base to the hydroxyl-substituted phenyllactic acid compound and the second type of organic base is 1.5~1.7:1:0.1~0.2.

[0047] The hydroxylated benzaldehyde compound is added to the organic base at a temperature between 50°C and 100°C, preferably between 70°C and 80°C.

[0048] The reaction time of the hydroxyl-substituted benzaldehyde compound with the organic base is between 12 and 24 hours, with a preferred reaction time of 20 hours.

[0049] The following are specific embodiments provided by the inventors to further explain the technical solution of the present invention. The raw materials, reagents, and catalysts used in the embodiments are all commercially available products.

[0050] Examples 1-13 below relate to the synthesis of compounds 1a-g, and the specific synthetic routes are as follows:

[0051]

[0052] Reaction conditions: a. Tanshinone, alcohols, and TsOH are added to 1,4-dioxane and stirred at reflux for 3 hours (3b-f) or 6 hours (3g); b. Tanshinone (or 3b-g) and McMurray acid are added to 1,4-dioxane and reacted at 100°C for 3 hours. The mixture is then cooled to 70°C, protocatechuic aldehyde, pyridine, and morpholine are added, and the mixture is stirred at 70°C for 20 hours.

[0053] Example 1: Synthesis of Tanshinone Methyl Ester (3b)

[0054] A solution of tanshinone (DSS, 10.0 g, 50.5 mmol), methanol (8.1 g, 252 mmol), and 4-toluenesulfonic acid monohydrate (1.92 g, 10 mmol) in 1,4-dioxane (50 mL) was stirred under reflux for 3 hours. The reaction was monitored by TLC until the remaining DSS was below 5% (w / w). The solvent was evaporated, and the residue was transferred to an aqueous solution (200 mL). The residue was extracted with ethyl acetate (3 × 150 mL), washed sequentially with saturated saline (NaHCO3) and brine, dried over anhydrous Na2SO4, concentrated, and purified by column chromatography (petroleum ether / ethyl acetate gradient: 100% petroleum ether to 50 / 50 petroleum ether / ethyl acetate) to obtain 9.9 g of the target product, a light yellow oily substance with a yield of 93%. The NMR data of the obtained product are as follows: 1 H NMR(400MHz,Chloroform-d)δ6.70(d,J=7.6Hz,2H),6.55(d,J=8.0Hz,1H),6.17(s,2H),4.49-4. 36(m,1H),3.76(s,3H),3.28(s,1H),2.99(dd,J=14.0,4.0Hz,1H),2.81(dd,J=14.1,6.9Hz,1H). 13 C NMR(101MHz,Chloroform-d)δ174.87,143.75,142.98,128.72,121.87,116.82,115.61,77.48,71.60,52.76,39.86.ESI(M+Na) + m / z: 235.10 (calcd for C 10 H 12 NaO5235.06).

[0055] The structural formula of the obtained compound is:

[0056]

[0057] Example 2: Synthesis of Tanshinone Ethyl Ester (3c)

[0058] The synthesis was performed according to the method of Example 1, except that ethanol was used instead of methanol, yielding 10.2 g of tanshinone ethyl ester, with a yield of 90%, as a light yellow oil. The NMR data of the obtained product are as follows: 1 H NMR (300MHz, DMSO-d6) δ8.69(s,1H),8.60(s,1H),6.61(d,J=5.7Hz,1H),6.59(s,1H),6.43(dd,J=8.0,1.9Hz,1H),5.40 (d,J=6.1Hz,1H),4.15-4.08(m,1H),4.04(q,J=7.1Hz,2H),2.69(ddd,J=21.1,13.7,6.5Hz,2H),1.14(t,J=7.1Hz,3H). 13 CNMR(75MHz,DMSO-d6)δ173.56,144.76,143.69,128.22,120.03,116.82,115.22,71.70,59.91,39.70,14.08.ESI(M+Na) + m / z:249.10 (calcd for C 11 H 14 NaO5249.08).

[0059] The structural formula of the obtained compound is:

[0060]

[0061] Example 3: Synthesis of Tanshinone n-propyl ester (3d)

[0062] The synthesis was carried out according to the method of Example 1, except that n-propanol was used instead of methanol, yielding 10.9 g of tanshinone n-propyl ester, with a yield of 91%, as a light yellow oil. The NMR data of the obtained product are as follows: 1H NMR (300MHz, DMSO-d6) δ8.69(s,1H),8.60(s,1H),6.61(d,J=5.4Hz,1H),6.59(s,1H),6.43(dd,J=8.0,1.9Hz,1H),5.41(s,1H ),4.12(t,J=6.3Hz,1H),3.95(t,J=6.6Hz,2H),2.70(ddd,J=21.1,13.7,6.5Hz,2H),1.61-1.46(m,2H),0.84(t,J=7.4Hz,3H). 13 C NMR(75MHz,DMSO-d6)δ173.67,144.80,143.71,128.23,120.00,116.79,115.23,71.75,65.40,39.80,21.53,10.22.ESI(M+Na) + m / z:263.10 (calcd for C 12 H 16 NaO5 263.09).

[0063] The structural formula of the obtained compound is:

[0064]

[0065] Example 4: Synthesis of Tanshinone Isopropyl Ester (3e)

[0066] The synthesis was carried out according to the method of Example 1, except that isopropanol was used instead of methanol, yielding 10.6 g of tanshinone isopropyl ester, with a yield of 88%, as a light yellow oil. The NMR data of the obtained product are as follows: 1 H NMR (300MHz, DMSO-d6) δ8.65(s,2H),6.60(d,J=4.5Hz,1H),6.59(d,J=1.2Hz,1H),6.43(dd,J=8.0,2.0Hz,1H),4.85(hept,J =6.3Hz,1H),4.06(t,J=6.9Hz,1H),3.43(s,1H),2.68(qd,J=13.6,6.6Hz,2H),1.16(d,J=6.4Hz,3H),1.10(d,J=6.3Hz,3H). 13 C NMR(75MHz,DMSO-d6)δ173.13,144.78,143.70,128.17,120.08,116.87,115.20,71.77,67.32,21.61,21.49.ESI(M+Na) + m / z:263.10 (calcd for C12 H 16 NaO5 263.09).

[0067] The structural formula of the obtained compound is:

[0068]

[0069] Example 5: Synthesis of Tanshinone n-butyl ester (3f)

[0070] The synthesis was carried out according to the method of Example 1, except that n-butanol was used instead of methanol, yielding 11.8 g of tanshinone n-butyl ester, with a yield of 93%, as a light yellow oil. The NMR data of the obtained product are as follows: 1 H NMR (400MHz, DMSO-d6) δ8.67(s),6.61(d,J=5.3Hz),6.60(s),6.43(dd,J=8.0,1.9Hz),5.43(d,J=5.1Hz),4.13(d,J= 3.9Hz), 4.02-3.97(m), 2.71(ddd,J=21.1,13.7,6.5Hz), 1.54-1.45(m), 1.26(dd,J=15.0,7.4Hz), 0.86(t,J=7.4Hz). 13 CNMR(101MHz,DMSO-d6)δ173.78,144.90,143.84,128.30,120.10,116.88,115.30,71.86,63.73,39.88,30.30,18.70,13.64.ESI(M+Na) + m / z:277.10 (calcd for C 13 H 18 NaO5 277.11).

[0071] The structural formula of the obtained compound is:

[0072]

[0073] Example 6: Synthesis of Tanshinone Dextroborneol Ester (3g)

[0074] The synthesis was carried out according to the method of Example 1, except that dextrorotatory borneol was used instead of methanol. The reaction was carried out for 6 hours to obtain 13.9 g of tanshinone dextrorotatory borneol ester, with a yield of 83%, as a light yellow oil. The NMR data of the obtained product are as follows: 1H NMR (300MHz, DMSO-d6) δ8.67(s,1H),8.60(s,1H),6.60(d,J=7.9Hz,2H),6.44(dd,J=8.0,2.0Hz,1H ),5.40(d,J=5.9Hz,1H),4.70(d,J=8.7Hz,1H),4.17(q,J=6.4Hz,1H),2.72(d,J=6.6Hz,2H),2.28-2 .08(m,1H),1.78(td,J=9.5,5.0Hz,1H),1.63(ddt,J=17.0,8.1,3.7Hz,2H),1.32-1.15(m,1H),1.07 (ddd,J=13.7,9.7,4.3Hz,1H),0.84(s,3H),0.82(s,3H),0.76(s,3H),0.71(dd,J=13.7,3.4Hz,1H). 13 C NMR(75MHz,DMSO-d6)δ173.81,144.81,143.71,128.00,119.98,116.77,115.16,79.07, 71.54,48.29,47.33,44.16,39.86,35.88,27.38,26.63,19.47,18.56,13.33.ESI(M+Na) + m / z:357.20 (calcd for C 19 H 26 NaO5 357.17).

[0075] The structural formula of the obtained compound is:

[0076]

[0077] Example 7: Synthesis of (+)-Rosmarinic Acid (1a)

[0078] Add McMurray acid (2.71 g, 18.8 mmol) to a solution of 1,4-dioxane (30 mL) containing tanshinone (2.48 g, 12.5 mmol). Heat the reaction solution to reflux and react for 4 hours. Cool the reaction solution to 70 °C and add protocatechuic aldehyde (1.81 g, 13.15 mmol), pyridine (1.68 g, 21.3 mmol), and morpholine (0.16 g, 1.88 mmol). Stir at 70 °C for 20 hours. Stop the reaction, add water (100 mL), stir for 5 min, extract with ethyl acetate (3 × 150 mL), wash with saturated brine, dry the combined organic phases with anhydrous Na2SO4, concentrate under reduced pressure to obtain crude product, and purify by column chromatography (CH2Cl2 / methanol gradient: 100% CH2Cl2 to 95 / 5 CH2Cl2 / methanol) to obtain (+)-rosmarinic acid 2.45 g, yield 54%, as a pale yellow solid. The NMR data of the obtained product are as follows: 1 H NMR(300MHz,DMSO-d6)δ7.38(d,J=15.8Hz,1H),7.06(d,J=1.8Hz,1H),6.93( dd,J=8.2,1.8Hz,1H),6.75(d,J=8.1Hz,1H),6.67(d,J=1.8Hz,1H),6.60(d,J =8.0Hz,1H),6.49(dd,J=8.0,1.8Hz,1H),6.19(d,J=15.9Hz,1H),4.86(dd,J =9.9,3.0Hz,1H),3.00(dd,J=14.0,2.5Hz,1H),2.77(dd,J=14.2,9.9Hz,1H). 13 C NMR(75MHz,DMSO-d6)δ173.29,166.41,148.77,146.00,145.07,144.70,143.76,1 29.73,121.13,119.85,116.78,116.11,115.58,115.14,75.92,37.30.ESI(M+Na) + m / z:383.1 (calcd for C 18 H 16 NaO8 383.2).

[0079] The structural formula of the obtained compound is:

[0080]

[0081] Example 8: Synthesis of (+)-Rosmarinate Methyl Ester (1b)

[0082] The synthesis was carried out according to the method of Example 7, except that tanshinone methyl ester was used instead of tanshinone, yielding 3.24 g of (+)-rosmarinic acid methyl ester, with a yield of 69%, as a light yellow solid. The NMR data of the obtained product are as follows: 1 H NMR (400MHz, DMSO-d6) δ7.49(d,J=15.9Hz,1H),7.06(s,1H),7.03(d,J=8.2Hz,1H),6.77(d,J=8.1Hz,1H),6.64(d,J=8.1Hz,2 H), 6.50 (dd, J = 8.0, 1.8Hz, 1H), 6.27 (d, J = 15.9Hz, 1H), 5.11 (dd, J = 7.3, 5.4Hz, 1H), 3.63 (s, 3H), 2.95 (h, J = 8.3, 7.5Hz, 2H). 13 C NMR(101MHz,DMSO-d6)δ170.04,165.99,148.83,146.47,145.68,145.06,144.20,126.68,125 .32,121.80,120.14,116.73,115.81,115.49,115.04,72.88,52.09,39.94,36.24.ESI(M+Na) + m / z: 397.3 (calcd for C 19 H 18 NaO8 397.3).

[0083] The structural formula of the obtained compound is:

[0084]

[0085] Example 9: Synthesis of (+)-Ethyl rosmarinic acid (1c)

[0086] The synthesis was carried out according to the method of Example 7, except that tanshinone ethyl ester was used instead of tanshinone, yielding 3.55 g of (+)-rosmarinic acid ethyl ester, a white solid with a yield of 73%. MPa: 80.3-82.6℃. The NMR data of the obtained product are as follows: 1H NMR (300MHz, DMSO-d6) δ8.80(s,1H),7.50(d,J=15.9Hz,1H),7.07(s,1H),7.03(d,J=8.3Hz,1H),6.78(d,J=8.1Hz,1H),6.65(d,J=8.0Hz,2H), 6.51(d,J=8.0Hz,1H), 6.27(d,J=15.9Hz,1H), 5.09(t,J=6.4Hz,1H), 4.09(q,J=6.4,5.7Hz,2H), 2.96(d,J=6.4Hz,2H), 1.13(d,J=7.1Hz,3H). 13 C NMR(75MHz,DMSO-d6)δ169.43,165.92,148.75,146.30,145.64,145.00,144.15,126.63,125.33 ,121.69,120.14,116.77,115.79,115.43,115.00,112.93,72.88,60.76,36.22,13.97.ESI(M+H) + m / z:389.1 (calcd for C 20 H 21 O8 389.1),(M+Na) + m / z:411.1 (calcd for C 20 H 20 NaO8 411.1).

[0087] The structural formula of the obtained compound is:

[0088]

[0089] Example 10: Synthesis of (+)-propyl rosmarinic acid (1d)

[0090] The synthesis was carried out according to the method of Example 7, except that tanshinone n-propyl ester was used instead of tanshinone, yielding 4.38 g of (+)-rosmarinic acid n-propyl ester, with a yield of 87%, as a white solid. MPa: 41.2-43.5℃. The NMR data of the obtained product are as follows: 1H NMR (300MHz, DMSO-d6) δ9.65 (s, 1H), 9.15 (s, 1H), 8.78 (s, 2H), 7.50 (d, J = 15.9Hz ,1H),7.07(s,1H),7.03(d,J=8.2Hz,1H),6.78(d,J=8.1Hz,1H),6.64(d,J=8.2Hz, 2H),6.51(d,J=8.0Hz,1H),6.27(d,J=15.9Hz,1H),5.10(t,J=6.4Hz,1H),4.00(t, J=5.4Hz,2H),2.96(d,J=6.3Hz,2H),1.53(h,J=6.9Hz,2H),0.83(t,J=7.4Hz,3H). 13 C NMR(75MHz,DMSO-d6)δ169.51,165.93,148.73,146.28,145.63,145.01,144.15,126.63,125.32,121 .67,120.08,116.71,115.78,115.42,114.99,112.91,72.93,66.14,36.24,21.42,10.11.ESI(M+Na) + m / z: 425.3 (calcd for C 21 H 22 NaO8 425.1).

[0091] The structural formula of the obtained compound is:

[0092]

[0093] Example 11: Synthesis of (+)-Rosmarinate Isopropyl Ester (1e)

[0094] The synthesis was carried out according to the method of Example 7, except that tanshinone isopropyl ester was used instead of tanshinone, yielding 4.28 g of (+)-rosmarinic acid isopropyl ester, a white solid with a yield of 85%. MPa: 40.2-41.8℃. The NMR data of the obtained product are as follows: 1H NMR(300MHz,DMSO-d6)δ9.64(s,1H),9.15(s,1H),8.77(s,2H),7.50(d,J=15 .9Hz,1H),7.07(s,1H),7.03(d,J=8.3Hz,1H),6.77(d,J=8.1Hz,1H),6.64(d ,J=8.4Hz,2H),6.51(d,J=8.0Hz,1H),6.27(d,J=15.9Hz,1H),5.03(t,J=6.4 Hz, 1H), 4.87 (p, J = 6.2Hz, 1H), 2.94 (d, J = 6.3Hz, 2H), 1.10 (d, J = 6.2Hz, 3H). 13 C NMR(75MHz,DMSO-d6)δ168.92,165.92,148.70,146.21,145.62,144.97,144.12,126.54,125.33,121 .65,120.16,116.79,115.77,115.38,114.98,112.95,73.00,68.36,36.17,21.45,21.33.ESI(M+Na) + m / z:425.1(calcdfor C 21 H 22 NaO8 425.1).

[0095] The structural formula of the obtained compound is:

[0096]

[0097] Example 12: Synthesis of (+)-Rosmarinic acid n-butyl ester (1f)

[0098] The synthesis was carried out according to the method of Example 7, except that tanshinone n-butyl ester was used instead of tanshinone, yielding 4.32 g of (+)-rosmarinic acid n-butyl ester, with a yield of 83%, as a white solid. MPa: 38.9-40.3℃. The NMR data of the obtained product are as follows: 1H NMR(300MHz,DMSO-d6)δ9.62(s,1H),9.16(s,1H),8.77(s,2H),7.49(d,J=15.8Hz,1H),7 .07(s,1H),7.03(d,J=8.2Hz,1H),6.78(d,J=8.1Hz,1H),6.64(d,J=8.1Hz,2H),6.50(d, J=7.9Hz,1H),6.27(d,J=15.9Hz,1H),5.09(t,J=6.3Hz,1H),4.04(t,J=6.4Hz,2H),2.96 (d,J=6.1Hz,2H),1.49(dt,J=13.7,6.5Hz,2H),1.27-1.22(m,2H),0.85(t,J=7.3Hz,3H). 13 C NMR(75MHz,DMSO-d6)δ169.50,165.92,148.73,146.27,145.62,145.01,144.16,126.59,125.32, 121.66,120.07,116.70,115.78,115.40,114.98,112.91,64.36,30.02,18.46,13.48.ESI(M+Na) + m / z: 439.2 (calcd for C 22 H 24 NaO8439.1).

[0099] The structural formula of the obtained compound is:

[0100]

[0101] Example 13: Synthesis of (+)-rosmarinic acid dextroborneol ester (1g)

[0102] The synthesis was carried out according to the method of Example 7, except that tanshinone-derived dextrorotatory borneol ester was used instead of tanshinone, yielding 3.93 g of (+)-rosmarinic acid dextrorotatory borneol ester, with a yield of 67%, as a light yellow solid. MPa: 91-92.7℃. The NMR data of the obtained product are as follows: 1HNMR (400MHz, DMSO-d6) δ9.66(s,1H),9.16(s,1H),8.77(d,J=21.1Hz,2H),7.52(d,J=15.8Hz,1H),7.07(d,J=2.0Hz,1H),7.03(dd,J=8.3,2 .0Hz,1H),6.77(d,J=8.1Hz,1H),6.67(d,J=2.0Hz,1H),6.64(d,J=8.0Hz,1H),6.52(dd,J=8.0,2.0Hz,1H),6.30(d,J=15.9Hz,1H),5.10(t, J=6.6Hz,1H),4.71(dt,J=9.8,3.0Hz,1H),2.97(qd,J=14.2,6.6Hz,2H),2.14(ddd,J=13.5,9.4,3.7Hz,1H),1.70(ddd,J=12.8,9.3,3.9Hz, 1H),1.60(dd,J=12.7,6.1Hz,2H),1.21-1.14(m,1H),1.06-0.98(m,1H),0.87(q,J=4.5,3.9Hz,1H),0.82(s,3H),0.80(s,3H),0.73(s,3H). 13 C NMR(101MHz,DMSO-d6)δ169.68,166.04,148.72,146.23,145.62,145.02,144.17,126.36,125.35,121.67,120.14,116.75 ,115.78,115.36,114.98,112.91,79.84,73.14,48.40,47.37,44.09,35.59,27.28,26.57,19.45,18.56,13.17.ESI(M+Na) + m / z: 519.2 (calcd for C) 28 H 32 NaO8 519.2).

[0103] The structural formula of the obtained compound is:

[0104]

[0105] Examples 14-15 below relate to the synthesis of compounds 5a-b, and the specific synthetic routes are as follows:

[0106]

[0107] Example 14: Synthesis of (R)-3-(4-hydroxyphenyl)-1-methoxy-1-oxopropyl-2-yl(E)-3-(3,4-dihydroxyphenyl)acrylate (5a)

[0108] Step 1: Synthesize according to the method of Example 1, except that d-p-hydroxyphenyllactic acid was used instead of tanshinone to obtain 9.3 g of methyl d-p-hydroxyphenyllactic acid, with a yield of 95%, as a light yellow oil. The NMR data of the obtained product are as follows: 1 H NMR (400MHz, DMSO-d6) δ9.17 (s, 1H), 6.98 (d, J = 8.4Hz, 2H), 6.67-6.62 (m, 2H), 5. 47(d,J=6.2Hz,1H),4.14(dt,J=7.7,5.6Hz,1H),3.59(s,3H),2.85-2.66(m,2H). 13 C NMR(101MHz,DMSO-d6)δ174.12,155.86,130.39,127.67,114.93,71.65,51.40,39.41.ESI(M+Na) + m / z:219.00 (calcd for C 10 H 12 NaO4 219.06).

[0109] Step two: The synthesis was carried out according to the method of Example 7, except that methyl p-hydroxyphenyl lactate was used instead of tanshinone to obtain 3.14 g of (R)-3-(4-hydroxyphenyl)-1-methoxy-1-oxopropyl-2-yl(E)-3-(3,4-dihydroxyphenyl)acrylate, with a yield of 70%, as a light yellow solid. Mp 46.8-48.8℃. The NMR data of the obtained product are as follows: 1 H NMR(400MHz, DMSO-d6)δ9.27(s,1H),7.48(d,J=15.9Hz,1H),7.09-7.05(m,3H),7.02(dd,J=8.1,2.0Hz,1H),6.77(d,J= 8.1Hz,1H),6.68(d,J=6.6Hz,2H),6.27(d,J=15.9Hz,1H),5.14(dd,J=7.6,5.2Hz,1H),3.63(s,3H),3.08-2.97(m,2H). 13C NMR (101MHz, DMSO-d6) δ169.95,165.91,156.22,148.76,145.63,130.45,130. 23,126.02,125.30,121.78,121.56,115.78,115.12,72.91,52.04.ESI(M+Na) + m / z:381.10 (calcd for C 19 H 18 NaO7381.10).

[0110] The structural formula of the obtained compound is:

[0111]

[0112] Example 15: Synthesis of (R)-3-(5-hydroxy-1H-indol-2-yl)-1-methoxy-1-oxopropyl-2-yl(E)-3-(3,4-dihydroxyphenyl)acrylate (5b)

[0113] Step 1: Synthesize according to the method in Example 1, except that (R)-2-hydroxy-3-(5-hydroxy-1H-2-indole)propionic acid is used instead of tanshinone to obtain 8.8 g of methyl (R)-2-hydroxy-3-(5-hydroxy-1H-2-indole)propionic acid, with a yield of 75%, as a light yellow oil. The NMR data of the obtained product are as follows: 1 H NMR (400MHz, DMSO-d6) δ10.49(s,1H),8.59(s,1H),7.12(d,J=8.6Hz,1H),7.01(d,J=2.0Hz,1H),6.81(d,J=1.9H z,1H),6.58(dd,J=8.6,2.1Hz,1H),5.49(d,J=6.0Hz,1H),4.25(q,J=6.0Hz,1H),3.58(s,3H),3.01-2.84(m,2H). 13 C NMR(101MHz,DMSO-d6)δ174.38,150.28,130.67,128.16,124.38,111.84,111.25,108.84,102.30,51.43,30.44.ESI(M+H) + m / z: 236.00, (M+Na) + m / z:258.00 (calcd for C 12 H 14 NO4 236.08,C 12 H 13 NNaO4 258.07).

[0114] Step 2: Synthesize according to the method in Example 7, except that methyl (R)-2-hydroxy-3-(5-hydroxy-1H-2-indolyl)propionate was used instead of tanshinone, yielding 2.24 g of (R)-3-(5-hydroxy-1H-indolyl-2-yl)-1-methoxy-1-oxopropyl-2-yl(E)-3-(3,4-dihydroxyphenyl)acrylate, yield 45%, as a pale yellow solid. MP 89.2-93.4℃. The NMR data of the obtained product are as follows: 1 H NMR (400MHz, DMSO-d6) δ10.60(s,1H),8.67(s,1H),7.47(d,J=15.9Hz,1H),7. 13(d,J=8.6Hz,2H),7.06(d,J=2.0Hz,1H),7.01(dd,J=8.2,2.0Hz,1H),6.89( d,J=2.2Hz,1H),6.76(d,J=8.1Hz,1H),6.60(dd,J=8.6,2.3Hz,1H),6.27(d,J =15.9Hz,1H),5.18(dd,J=6.9,5.4Hz,1H),3.64(s,3H),3.18(d,J=6.8Hz,2H). 13 C NMR(101MHz,DMSO-d6)δ170.20,166.11,150.50,148.75,146.38,145.63,130.61,128.05,125.36, 124.53,121.84,115.74,114.95,112.99,111.38,107.54,102.18,72.70,52.06,27.07.ESI(M+Na) + m / z:420.20 (calcd for C 21 H 19 NNaO7 420.11).

[0115] The structural formula of the obtained compound is:

[0116]

[0117] Examples 16-21 below relate to the synthesis of compounds 6a-f, and the specific synthetic routes are as follows:

[0118]

[0119] Example 16: Synthesis of (R)-3-(3,4-dihydroxyphenyl)-1-isopropoxy-1-oxopropane-2-yl(E)-3-(4-hydroxyphenyl)acrylate (6a)

[0120] The synthesis was carried out according to the method of Example 7, except that tanshinone isopropyl ester was used instead of tanshinone, and p-hydroxybenzaldehyde was used instead of protocatechuic aldehyde, yielding 3.14 g of (R)-3-(3,4-dihydroxyphenyl)-1-isopropoxy-1-oxopropane-2-yl(E)-3-(4-hydroxyphenyl)acrylate, with a yield of 65%, as a light green solid. MPa: 41.6-43.8℃. The NMR data of the obtained product are as follows: 1 HNMR (400MHz, DMSO-d6) δ10.08(s,1H),8.80(s,2H),7.58(dd,J=11.9,3.5Hz,3H),6.80(d,J=8.2Hz,2H),6.69-6.61(m,2H),6.51(d,J=7.1Hz,1H) ,6.41(d,J=16.0Hz,1H),5.03(t,J=6.4Hz,1H),4.86(dq,J=11.8,6.1Hz, 1H), 2.94 (d, J = 6.3Hz, 2H), 1.16 (d, J = 6.2Hz, 3H), 1.09 (d, J = 6.2Hz, 3H). 13 C NMR(101MHz,DMSO-d6)δ168.98,166.05,160.16,145.88,145.01,144.16,130.62,126.55,12 4.94,116.81,116.39,115.96,115.40,113.14,72.78,68.51,36.20,21.47,21.36.ESI(M+Na) + m / z:409.10 (calcd for C 21 H 22 NaO7 409.13).

[0121] The structural formula of the obtained compound is:

[0122]

[0123] Example 17: Synthesis of (R)-3-(3,4-dihydroxyphenyl)-1-isopropoxy-1-oxopropyl-2-yl(E)-3-(3-hydroxyphenyl)acrylate (6b)

[0124] The synthesis was carried out according to the method of Example 7, except that tanshinone isopropyl ester was used instead of tanshinone, and 3-hydroxybenzaldehyde was used instead of protocatechuic aldehyde, yielding 3.59 g of (R)-3-(3,4-dihydroxyphenyl)-1-isopropoxy-1-oxopropyl-2-yl(E)-3-(3-hydroxyphenyl)acrylate, with a yield of 74%, as a white solid. MPa: 73.9-75.8℃. The NMR data of the obtained product are as follows: 1H NMR (400MHz, DMSO-d6) δ8.49 (s, 1H), 7.56 (d, J = 16.0Hz, 1H), 7.25-7.09 (m, 3H), 6.88-6.82 (m, 1H), 6.71-6.60 (m, 2H), 6.57-6 .47(m,2H),5.04(t,J=6.4Hz,1H),4.87(p,J=6.2Hz,1H),2.95(d,J=6.5Hz,2H),1.17(d,J=6.2Hz,3H),1.10(d,J=6.2Hz,3H). 13 C NMR(101MHz,DMSO-d6)δ168.87,165.68,158.16,146.06,145.29,144.48,135.02,130.14,126.36 ,120.14,119.45,118.21,117.07,116.88,115.59,115.09,68.65,40.14,36.22,21.41.ESI(M+Na) + m / z: 409.20 (calcd for C 21 H 22 NaO7 409.13).

[0125] The structural formula of the obtained compound is:

[0126]

[0127] Example 18: Synthesis of (R)-3-(3,4-dihydroxyphenyl)-1-isopropoxy-1-oxopropane-2-yl(E)-3-(2,3-dihydroxyphenyl)acrylate (6c)

[0128] The synthesis was carried out according to the method of Example 7, except that tanshinone isopropyl ester was used instead of tanshinone, and 2,3-dihydroxybenzaldehyde was used instead of protocatechuic aldehyde, yielding 2.65 g of (R)-3-(3,4-dihydroxyphenyl)-1-isopropoxy-1-oxopropane-2-yl(E)-3-(2,3-dihydroxyphenyl)acrylate, with a yield of 52%, as a light green solid. MPa: 89.9-93.4℃. The NMR data of the obtained product are as follows: 1H NMR(400MHz,)δ8.39(s,2H),7.91(d,J=16.1Hz,1H),7.04(dd,J=7.9,1.3Hz,1H),6.85(dd,J=7.8,1.3Hz,1H),6.66-6.62(m,3H),6.57(d,J=16.1Hz ,1H),6.50(dd,J=8.0,2.0Hz,1H),5.04(t,J=6.6Hz,1H),4.87(p,J=6.3Hz ,1H),2.95(d,J=6.7Hz,2H),1.17(d,J=6.2Hz,3H),1.10(d,J=6.2Hz,3H). 13 C NMR(101MHz,DMSO-d6)δ169.00,166.33,146.32,145.20,144.35,142.03,120 .10,119.06,116.87,115.69,115.59,73.27,68.49,36.24,21.50.ESI(M+Na) + m / z: 425.10 (calcd for C 21 H 22 NaO8 425.12).

[0129] The structural formula of the obtained compound is:

[0130]

[0131] Example 19: Synthesis of (R)-3-(3,4-dihydroxyphenyl)-1-isopropoxy-1-oxopropane-2-yl(E)-3-(2,4-dihydroxyphenyl)acrylate (6d)

[0132] The synthesis was carried out according to the method of Example 7, except that tanshinone isopropyl ester was used instead of tanshinone, and 2,4-dihydroxybenzaldehyde was used instead of protocatechuic aldehyde, yielding 2.28 g of (R)-3-(3,4-dihydroxyphenyl)-1-isopropoxy-1-oxopropane-2-yl(E)-3-(2,4-dihydroxyphenyl)acrylate, with a yield of 45%, as a dark green solid. MPa: 65.2-67.4℃. The NMR data of the obtained product are as follows: 1H NMR(400MHz,DMSO-d6)δ7.78(d,J=16.0Hz,1H),7.42(d,J=8.6Hz,1H),6.66- 6.62(m,2H),6.50(dd,J=8.0,2.0Hz,1H),6.40(d,J=16.0Hz,1H),6.37(d,J= 2.2Hz, 1H), 6.28 (dd, J = 8.5, 2.1Hz, 1H), 5.02 (t, J = 6.6Hz, 1H), 4.87 (p, J = 6. 2Hz, 1H), 2.93 (d, J = 6.6Hz, 2H), 1.16 (d, J = 6.2Hz, 3H), 1.09 (d, J = 6.2Hz, 3H). 13 C NMR(101MHz,DMSO-d6)δ169.10,166.66,161.29,158.83,144.99,144.11,141.75,130.82,126.62,12 0.15,116.72,115.41,112.48,111.89,107.92,102.52,72.99,68.38,36.24,21.48,21.35.ESI(M+Na) + m / z: 425.30 (calcd for C 21 H 22 NaO8 425.12).

[0133] The structural formula of the obtained compound is:

[0134]

[0135] Example 20: Synthesis of (R)-3-(3,4-dihydroxyphenyl)-1-isopropoxy-1-oxopropyl-2-yl(E)-3-(2,3,4-trihydroxyphenyl)acrylate (6e)

[0136] The synthesis was carried out according to the method of Example 7, except that tanshinone isopropyl ester was used instead of tanshinone, and 2,3,4-trihydroxybenzaldehyde was used instead of protocatechuic aldehyde, yielding 3.71 g of (R)-3-(3,4-dihydroxyphenyl)-1-isopropoxy-1-oxopropyl-2-yl(E)-3-(2,3,4-trihydroxyphenyl)acrylate, with a yield of 71%, as a pale yellow solid. MPa: 72.8-74.2℃. The NMR data of the obtained product are as follows: 1H NMR (400MHz, DMSO-d6) δ9.17(s,1H),8.77(s,1H),8.72(s,1H),7.78(d,J=16.0Hz ,1H),6.96(d,J=8.7Hz,1H),6.63(dd,J=5.0,3.0Hz,2H),6.50(dd,J=8.1,2.0Hz,1 H),6.42(d,J=16.0Hz,1H),6.36(d,J=8.6Hz,1H),5.02(t,J=6.6Hz,1H),4.87(p, J=6.3Hz,1H),2.93(d,J=6.7Hz,2H),1.16(d,J=6.2Hz,3H),1.09(d,J=6.3Hz,3H). 13 CNMR(101MHz,DMSO-d6)δ166.62,148.98,147.32,144.97,144.09,142.42,132.80,126.60,120.2 5,120.11,116.67,115.41,113.44,112.35,107.68,72.90,68.28,36.22,21.46,21.32.ESI(M+Na) + m / z:441.20 (calcd for C 21 H 22 NaO9441.12).

[0137] The structural formula of the obtained compound is:

[0138]

[0139] Example 21: Synthesis of (R)-3-(3,4-dihydroxyphenyl)-1-isopropoxy-1-oxopropane-2-yl(E)-3-(3,4,5-trihydroxyphenyl)acrylate (6f)

[0140] The synthesis was carried out according to the method of Example 7, except that tanshinone isopropyl ester was used instead of tanshinone, and 3,4,5-trihydroxybenzaldehyde was used instead of protocatechuic aldehyde, yielding 4.25 g of (R)-3-(3,4-dihydroxyphenyl)-1-isopropoxy-1-oxopropyl-2-yl(E)-3-(3,4,5-trihydroxyphenyl)acrylate, with a yield of 81%, as a pale yellow solid. MPa: 76.9-79.8℃. The NMR data of the obtained product are as follows: 1H NMR (400MHz, DMSO-d6) δ8.79(s,2H),7.40(d,J=15.8Hz,1H),6.68-6.58(m,4H),6.51(dd,J=8.0,2.0Hz,1H),6.17(d,J=15. 9Hz, 1H), 5.01 (t, J = 6.5Hz, 1H), 4.87 (p, J = 6.2Hz, 1H), 2.94 (d, J = 6.4Hz, 2H), 1.16 (d, J = 6.2Hz, 3H), 1.10 (d, J = 6.2Hz, 3H). 13 C NMR(101MHz,DMSO-d6)δ169.02,165.96,146.66,146.23,145.04,144.20,136.88, 126.64,124.23,120.25,116.87,107.92,107.86,68.58,36.24,21.54.ESI(M+Na) + m / z:441.20 (calcd for C 21 H 22 NaO9 441.12).

[0141] The structural formula of the obtained compound is:

[0142]

[0143] Example 22: Toxicity Study of Rosmarinic Acid and its Analogs on Zebrafish

[0144] 1. Experimental Methods:

[0145] Well-developed 24hpf Tg(fli1-EGFP) zebrafish were selected and cultured in sterile 24-well plates. Tolerance to the test compounds 1a-g, 5a-5b, and 6a-f was evaluated at concentrations of 50, 100, 250, 500, 1000, 1500, 2000, 2500, 5000, and 8000 μmol / L (water as solvent). Tolerance to the test compounds was evaluated at 1h at concentrations of 0.01, 0.1, 1, 5, 10, 50, 100, and 500 μmol / L (water as solvent). The final volume of the solution system in each well was 2 mL. After the drugs were added, 15 juvenile fish were added to the corresponding wells, capped, and labeled.

[0146] After the medication was administered, the culture plate was placed in a light incubator. The plate was observed every 4 hours, the number of dead fish was recorded, and the dead juveniles were removed. The results were recorded 24 hours after the medication was administered. The experiment was repeated three times.

[0147] 2. Experimental Results:

[0148] Depend on Figure 1 It can be seen that compound 1a: LC 50 =763 μmol / L; Compound 1h: LC 50 = 9.57 μmol / L; Compound 5a: LC 50 = 611 μmol / L; Compound 6a: LC 50 =623 μmol / L.

[0149] Furthermore, the effects of compound 1h (concentration of 1-6 μmol / L) and compounds 1a-g, 5a-b, and 6a-f (concentration of 12.5-50 μmol / L) on the blood vessels of a PTK787-induced zebrafish model of insufficient intersegmental angiogenesis were tested at different concentrations.

[0150] Example 23: Effects of rosmarinic acid and its analogues on angiogenesis in a PTK787-induced zebrafish model of insufficient intersegmental angiogenesis.

[0151] 1. Principle:

[0152] Angiogenesis refers to the biological process of growing new blood vessels on the basis of existing vascular structures. It is a complex process involving multiple cells, matrix, and cytokines. Vascular endothelial cells serve as a mechanical barrier between circulating blood and vascular smooth muscle. In the treatment of ischemic diseases, promoting endothelial cell proliferation, reconstructing microcirculation in the ischemic area, and promoting angiogenesis are important therapeutic approaches. Zebrafish, in the early stages of development, do not depend on blood circulation for survival and do not die from circulatory loss as in mammals. Therefore, this invention uses vatalani (PTK787) to induce angiogenesis loss in zebrafish, and then screens for angiogenesis promoters.

[0153] 2. Experimental Methods:

[0154] 2.1 Evaluation of activity in promoting intersegmental angiogenesis:

[0155] Before the formal experiment, adult fish were mated and spawned. Six hours after the fertilized eggs were collected, PTU (1 mg / mL) was added at a ratio of 30 μL / mL to inhibit melanin growth, ensure the fish were transparent, and avoid statistical errors.

[0156] After the model was established stably, well-developed 24hpf Tg(fli1-EGFP) zebrafish embryos were selected under a microscope, transferred to 5mL centrifuge tubes, and demembranes were removed by adding 1mg / mL of demembranes remover (streptolysin E). The embryos were then washed three times with fresh fish water. Using sterile 24-well plates, the experiment included a normal control group, a model group, a positive control group (Danhong injection), and groups treated with different concentrations (12.5, 25, and 50 μmol / L) of the compound.

[0157] The above experiment used a combination of modeling and treatment drugs. Except for the control group, all other groups received 0.175 μg / mL PTK787, with a final solution volume of 2 mL in each well. Ten juvenile fish were transferred to their corresponding wells, capped, and labeled, then placed in a light incubator at a temperature controlled at 28.5℃ ± 0.5℃. During the treatment, observations were conducted every 4 hours, and any juvenile fish that died due to chance were removed to avoid water pollution affecting the statistical results. After 24 hours of development, each fish was observed and images were acquired using a fluorescence microscope. To ensure more accurate statistical results, images were taken with the juvenile fish's eyes closed, and they were anesthetized with tricaine. The total length of intersegmental vessels was measured using IPP 5.1 software, and the experiment was repeated three times.

[0158] 3. Experimental Results:

[0159] Depend on Figure 2 It can be seen that all the tested compounds have significant angiogenesis-promoting activity, and the effect is more significant than that of the positive control drug Danhong injection.

Claims

1. A method for synthesizing rosmarinic acid, characterized in that, The structural formula of the rosmarinic acid is shown in (1a); The synthesis method includes: Step 1: Tanshinone reacts with McMurray acid in an organic solvent to generate an intermediate; Step 2: The obtained intermediate is reacted with protocatechuic aldehyde under the catalysis of an organic base to obtain rosmarinic acid.

2. A method for synthesizing a rosmarinic acid analogue, characterized in that, The structural formula of the analogue is as follows: 、 、 、 、 、 、 , , , , , , or ; The method for synthesizing the analogue includes: Step 1: A hydroxylated phenyllactic acid compound reacts with McMurray acid in an organic solvent to generate an intermediate; the hydroxylated phenyllactic acid compound is tanshinone methyl ester, tanshinone ethyl ester, tanshinone n-propyl ester, tanshinone isopropyl ester, tanshinone n-butyl ester, tanshinone dextrorotatory borneol ester, p-dextral p-hydroxyphenyllactic acid, or (R)-2-hydroxy-3-(5-hydroxy-1H-2-indolyl)propionic acid; Step 2: The obtained intermediate is reacted with a hydroxyl-substituted aromatic aldehyde under the catalysis of an organic base to obtain a rosmarinic acid analog.

3. The synthesis method according to claim 1 or 2, characterized in that, The intermediate does not require separation and reacts directly with protocatechuic aldehyde.

4. The synthesis method according to claim 1 or 2, characterized in that, The organic solvent is selected from 1,4-dioxane, N,N -Dimethylformamide, N,N -Dimethylacetamide, N One or a mixture of two or more of methylpyrrolidone, toluene, tetrahydrofuran, acetonitrile, and dimethyl sulfoxide.

5. The synthesis method according to claim 1 or 2, characterized in that, The reaction temperature for step 1 is 45℃~110℃.

6. The synthesis method according to claim 1 or 2, characterized in that, The reaction time for step 1 is 1 to 5 hours.

7. The synthesis method according to claim 1 or 2, characterized in that, The molar ratio of tanshinone or hydroxylated phenyl lactic acid compound to McMurray acid is 1:(1~5).

8. The synthesis method according to claim 1 or 2, characterized in that, The organic base includes a first type of organic base and a second type of organic base; the first type of organic base is selected from pyridine or 4-dimethylaminopyridine; the second type of organic base is selected from piperidine, morpholine, etc. N -Methylpiperazine, tetrahydropyrrole, or dimethylpyridineamine.

9. The synthesis method according to claim 8, characterized in that, The molar ratio of the first type of organic base, tanshinone or hydroxylated phenyl lactic acid compound, and the second type of organic base is 1:(1~2):(0.05~0.5).

10. The synthesis method according to claim 1 or 2, characterized in that, The reaction temperature in step 2 is 50℃~100℃.

11. The synthesis method according to claim 1 or 2, characterized in that, The reaction time for step 2 is 12 to 24 hours.

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