Application of 2-Trp-AA-tetrahydrocarboline-3-carboxylic acid compounds and PAF inhibitors thereof

Abstract

The present invention discloses four 2-Boc-Trp-AA-3S-tetrahydro-β-carboline-3-carboxylic acid compounds with the following structures that selectively inhibit PAF, wherein the amino acid represented by AA is selected from L-Glu residue, L-Lys residue, L-Leu residue and L-Ala residue, discloses the function of the compound as a selective inhibitor of platelet activating factor (PAF), and further discloses the preparation method of the compound and the use of the compound in the preparation of an anti-arterial thrombotic drug. Experiments have shown that the PAF selective inhibitor of the present invention has a good anti-arterial thrombotic effect. Therefore, it is proposed that the present invention provides an effective technical means for anti-arterial thrombosis. #imgabs0#

Description

Technical Field

[0001] The present invention relates to four types of 2-Boc-Trp-AA-3S-tetrahydro-β-carboline-3-carboxylic acid compounds that selectively inhibit PAF, and to their preparation methods and applications in treating arterial thrombotic diseases. The present invention belongs to the field of biomedicine. Background Art

[0002] Arterial embolism is one of the diseases with high morbidity and mortality. Arterial thrombosis is responsible for transient ischemic attack, acute coronary syndrome, myocardial infarction and atrial fibrillation. 18%-47% of patients with atrial fibrillation have coronary artery disease, and about 20% of patients with atrial fibrillation with coronary artery disease receive percutaneous coronary intervention. Arterial thrombosis is also responsible for arterial thrombosis and unstable angina after artificial heart valves, arteriovenous fistulas and other surgeries. For example, after liver transplantation, patients are at risk of hepatic artery thrombosis. In addition, patients with antiphospholipid syndrome are also at risk of arterial thrombosis. Arterial thrombosis is directly related to platelet aggregation. The inducers that usually induce platelet aggregation include platelet activating factor (PAF), adenosine diphosphate (ADP), thrombin (TH) and arachidonic acid (AA). Therefore, for researchers in this field, discovering selective inhibitors of platelet activating factor, adenosine diphosphate, thrombin and arachidonic acid is an important direction for the research of anti-arterial thrombotic drugs. The inventor screened out in long-term research

[0003] In the rat silk thread arterial thrombosis model, four 2-Boc-Trp-AA-3S-tetrahydro-β-carboline-3-carboxylic acids showed excellent anti-arterial thrombotic activity. Based on these research findings, the inventors proposed the present invention. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a novel platelet activating factor (PAF) selective inhibitor and a preparation method and application thereof.

[0005] In order to achieve the above-mentioned purpose, the present invention adopts the following technical means.

[0006] The first technical means is to propose a 2-Boc-Trp-AA-3S-tetrahydro-β-carboline-3-carboxylic acid compound having the following structure:

[0007]

[0008] The amino acid represented by AA in the formula is selected from: L-Glu residue, L-Lys residue, L-Leu residue or L-Ala residue.

[0009] The second technical means is to propose a method for preparing the 2-Boc-Trp-AA-3S-tetrahydro-β-carboline-3-carboxylic acid, which comprises the following steps:

[0010] 1) preparing 3S-tetrahydro-β-carboline-3-carboxylic acid;

[0011] 2) preparing Boc-Trp-AA, wherein AA is L-Glu residue, L-Lys residue, L-Leu residue and L-Ala residue;

[0012] 3) preparing 2-Boc-Trp-AA-3S-tetrahydro-β-carboline-3-carboxylic acid, wherein AA is an L-Glu residue, an L-Lys residue, an L-Leu residue and an L-Ala residue;

[0013] 4) preparing 2-Trp-AA-3S-tetrahydro-β-carboline-3-carboxylic acid, wherein AA is an L-Glu residue, an L-Lys residue, an L-Leu residue and an L-Ala residue.

[0014] The third object of the present invention is to provide the effect of the 2-Trp-AA-3S-tetrahydro-β-carboline-3-carboxylic acid as a selective inhibitor of platelet activating factor (PAF).

[0015] The fourth object of the present invention is to provide the selective inhibitory effect of 2-Trp-AA-3S-tetrahydro-β-carboline-3-carboxylic acid on PAF-induced platelet aggregation.

[0016] The fifth object of the present invention is to provide the role of the 2-Trp-AA-3S-tetrahydro-β-carboline-3-carboxylic acid in the preparation of drugs for inhibiting arterial thrombosis.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The present invention modifies carboline on the basis of its structure to prepare a class of 2-Trp-AA-3S-tetrahydro-β-carboline-3-carboxylic acids with the above structure. Experiments show that the compounds show good inhibitory effects on platelet activating factor (PAF) activity and arterial thrombosis.

[0019] The invention provides a new therapeutic drug for the treatment of arterial thrombosis, and enriches people's drug selection for the treatment of arterial thrombosis. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1The synthetic route of 2-Trp-AA-3S-tetrahydro-β-carboline-3-carboxylic acid: i) CH2O, H2SO4; ii) DCC, HOBt, N-methylmorpholine, Boc-Trp-AA; iii) 4N hydrogen chloride in ethyl acetate solution. DETAILED DESCRIPTION

[0021] In order to further illustrate the present invention, a series of embodiments are given below. These embodiments are purely illustrative and are only used to specifically describe the present invention and should not be construed as limiting the present invention.

[0022] Example 1 Preparation of 3S-tetrahydro-β-carboline-3-carboxylic acid (1)

[0023] Slowly add 0.2 mL of concentrated sulfuric acid to 400 mL of water. Add 5.0 g (24.5 mmol) of L-Trp to the obtained dilute sulfuric acid aqueous solution, and ultrasonically oscillate until L-Trp is completely dissolved. Add 10 mL of 35% formaldehyde aqueous solution to the obtained solution. The reaction mixture is stirred at room temperature for 6 hours, and the reaction is terminated when L-Trp disappears as monitored by thin layer chromatography (ethyl acetate / ether, 20 / 1). Slowly add concentrated ammonia water to the reaction solution, adjust to pH 6, and let stand for 30 minutes. Filter out the generated precipitate and wash with water. Spread the filtered colorless solid on a petri dish and dry in air to obtain 5.05 g (95%) of the title compound as a colorless solid. ESI-MS (m / e): 217 [M+H] + .

[0024] Example 2 Preparation of Boc-Trp-AA

[0025] Boc-Trp-Glu-O-CH3, Boc-Trp-Lys-O-CH3, Boc-Trp-Leu-O-CH3 and Boc-Trp-Ala-O-CH3 were prepared from Boc-Trp and Glu-O-CH3, Lys-O-CH3, Leu-O-CH3 and Ala-O-CH3 by conventional DCC method. Boc-Trp-Glu-O-CH3, Boc-Trp-Lys-O-CH3, Boc-Trp-Leu-O-CH3 and Boc-Trp-Ala-O-CH3 were saponified in 2N aqueous sodium hydroxide solution at 0℃ to obtain Boc-Trp-Glu, ESI-MS: 434[M+H] + ;Boc-Trp-Lys,ESI-MS:433[M+H] + ;Boc-Trp-Leu,ESI-MS:418[M+H] + and Boc-Trp-Ala, ESI-MS: 376[M+H] +Their yields all reached 91%, their purities all exceeded 98%, and they were all known compounds, so they were directly used in the subsequent synthetic reactions without being tested.

[0026] Example 3 Preparation of 3S-[2-(Boc-Trp-Clu)]-tetrahydro-β-carboline-3-carboxylic acid (2a)

[0027] 2.0 g (14.8 mmol) of N-hydroxybenzotriazole (HOBt) and 3.1 g (14.8 mmol) of dicyclohexylcarbodiimide (DCC) were added to a solution of 3.03 g (14 mmol) of 3S-tetrahydro-β-carboline-3-carboxylic acid, 6.06 g (14 mmol) of Boc-Trp-Glu and 150 mL of anhydrous tetrahydrofuran at 0°C. The reaction mixture was stirred at 0°C for 30 minutes. Then, the pH was adjusted to 8 with N-methylmorpholine (NMM). The reaction mixture was stirred at 0°C for 6 hours. The reaction was terminated when 3S-tetrahydro-β-carboline-3-carboxylic acid disappeared as monitored by thin layer chromatography (ethyl acetate / methanol, 20 / 1). The reaction mixture was filtered, and the filtrate was concentrated to dryness under reduced pressure. The residue was dissolved in 200 mL of ethyl acetate. The obtained solution was washed with 5% sodium bicarbonate aqueous solution (30 mL × 3), saturated sodium chloride aqueous solution (30 mL × 3), 5% hydrochloric acid aqueous solution (30 mL × 3), and saturated sodium chloride aqueous solution (30 mL × 3). The ethyl acetate layer was separated, dried over anhydrous sodium sulfate for 12 hours, filtered, and the filtrate was concentrated to dryness under reduced pressure to obtain 8.2 g (93%) of the title compound as a colorless powder. ESI-MS: 632 [M + H] + ; 1 HNMR (300MHz, DMSO-d6): δ / ppm=12.887(s,1H),12.015(s,1H),11.665(s,1H),10.783(s,1H),8.321(s,1H),7.583(d,J=7.6 Hz,1H),7.449(d,J=7.7Hz,1H),7.388(s,1H),7.373(d,J=7.9Hz,1H),7.212(d,J=7.9Hz,1H),7.201(s,1H),7.084(t,J=7.2 Hz,1H),6.985(t,J=7.2Hz,1H),6.933(t,J=7.2Hz,1H),6.914(t,J=7.2Hz,1H),5.074(t,J=5.6Hz,1H),4.922(t,J=5.6Hz,1 H),4.651(t,J1=6.1Hz,1H),4.467(s,2H),4.441(t,J=7.2Hz,2H),3.010(s,2H),2.332(m,2H),2.064(m,2H),1.423(s,9H);13 C NMR (75MHz, DMSO-d6): δ / ppm=178.50,172.82,171.82,160.68,136.45,135.80,130.22,126.36,125.32,123.02,121.90,121.70,119.85,119.81 ,118.84,118.66,121.73,111.56,111.53,109.72,104.89,79.48,67.93 ,59.55,55.82,38.76,30.63,28.87,28.57,28.67,27.75,27.21,22.54.

[0028] Example 4 Preparation of 3S-[2-(Trp-Clu)]-tetrahydro-β-carboline-3-carboxylic acid (3a)

[0029] Dissolve 5.6 g (8.9 mmol) of 3S-[2-(Boc-Trp-Clu)]-tetrahydro-β-carboline-3-carboxylic acid in 50 mL of ethyl acetate solution (4N) of hydrogen chloride, and stir the reaction mixture at room temperature for 60 minutes. The reaction was terminated when 3S-[2-(Boc-Trp-Clu)]-tetrahydro-β-carboline-3-carboxylic acid disappeared as monitored by thin layer chromatography (ethyl acetate / methanol, 20 / 1). The reaction mixture was concentrated under reduced pressure, and the residue was dissolved in 50 mL of ethyl acetate and concentrated again under reduced pressure. This operation was repeated 5 times to obtain 4.6 g (98%) of the title compound as a colorless powder. FT-ICR-MS: 532.2194 [M+H] + ; 1H NMR (300MHz, DMSO-d6): δ / ppm=12.887(s,1H),12.075(s,1H),11.665(s,1H),10.761(s,1H),8.862(s,2H),8.321(s,1H),7.58 3(d,J=7.6Hz,1H),7.349(d,J=7.7Hz,1H),7.332(d,J=7.7Hz,1H),7.212(d,J=7.7Hz,1H),7.209(s,1H),7.059(t,J=7.7Hz,1H) ,6.978(t,J=7.9Hz,1H),6.932(t,J=7.9Hz,1H),6.912(t,J=7.9Hz,1H),4.855(t,J=7.2Hz,1H),4.552(s,2H),4.444(t,J=7.2 Hz,1H),3.949(t,J=7.2Hz,1H),3.044(d,J=7.2Hz,2H),3.002(d,J=5.6Hz,2H),2.361(t,J=6.1Hz,2H),2.063(t,J=6.1Hz,2H); 13 C NMR (75MHz, DMSO-d6): δ / ppm=178.53,172.85,171.75,169.76,136.49,136.22,130.47,127.64,127.32,124.12,121.97,121. 76,119.89,119.84,118.87,118.69,111.59,111.55,107.12,104.98,67.95,56.55,55.02,38.06,30.03,27.57,27.27,22.64.

[0030] Example 5 Preparation of 3S-[2-(Boc-Trp-Lys)]-tetrahydro-β-carboline-3-carboxylic acid (2b)

[0031] Using the procedure of Example 3, 7.9 g (90%) of the title compound was obtained from 3.03 g (14 mmol) of 3S-tetrahydro-β-carboline-3-carboxylic acid and 6.05 g (14 mmol) of Boc-Trp-Lys as a colorless powder. ESI-MS: 631 [M+H] + ; 1H NMR (300MHz, DMSO-d6): δ / ppm=12.891(s,1H),12.001(s,2H),11.669(s,1H),10.781(s,1H),8.324(s,1H),7.582(d,J=7.6Hz,1H),7.392(s,1H) ),7.353(d,J=7.9Hz,1H),7.333(d,J=7.9Hz,1H),7.212(s,1H),7.210(d,J=7.9Hz,1H),7.064(t,J=7.2Hz,1H),6.982(t,J=7.2Hz,1H),6.931( t,J=7.2Hz,1H),6.912(t,J=7.2Hz,1H),4.920(t,J=5.6Hz,1H),4.851(t,J1=6.1Hz,1H),4.447(s,2H),4.440(t,J=7.2Hz,2H),3.330(d,J1=5. 6Hz, 2H), 3.040 (d, J1 = 6.1Hz, 1H), 2.691 (t, J = 5.6Hz, 2H), 1.764 (m, J = 7.2Hz, 2H), 1.533 (m, J = 7.2Hz, 2H), 1.253 (m, J = 7.2Hz, 2H), 1.433 (s, 9H); 13 CNMR (75MHz, DMSO-d6): δ / ppm=171.90,171.72,169.32,155.88,136.55,1 36.22,130.42,127.52,127.42,121.72,121.69,119.98,119.78,118.74, 118.56,111.16,111.13,109.75,104.99,79.49,67.90,59.52,55.62,42. 11,38.03,31.83,28.67,28.41,28.39,28.38,28.37,27.85,22.63,22.34.

[0032] Example 6 Preparation of 3S-[2-(Trp-Lys)]-tetrahydro-β-carboline-3-carboxylic acid (3b)

[0033] 4.4 g (93%) of the title compound was obtained from 5.6 g (8.9 mmol) of 3S-[2-(Boc-Trp-Lys)]-tetrahydro-β-carboline-3-carboxylic acid as a colorless powder using the procedure of Example 4. FT-ICR-MS: 531.2720 [M+H] + ; 1H NMR (300MHz, DMSO-d6): δ / ppm=12.892(s,1H),12.011(s,2H),11.679(s,1H),10.791(s,1H),8.862(s,2H),8.322(s,1H),7.580(d,J= 7.6Hz,1H),7.355(d,J=7.9Hz,1H),7.330(d,J=7.9Hz,1H),7.215(s,1H),7.212(d,J=7.9Hz,1H),7.062(t,J=7.2Hz,1H),6.985(t,J= 7.2Hz,1H),6.933(t,J=7.2Hz,1H),6.910(t,J=7.2Hz,1H),4.852(t,J1=6.1Hz,1H),4.457(s,2H),4.443(t,J=7.2Hz,2H),3.310(d,J 1=5.6Hz,2H),3.042(d,J1=6.1Hz,2H),2.693(t,J=5.6Hz,2H),1.774(m,J=7.2Hz,2H),1.535(m,J=7.2Hz,2H),1.255(m,J=7.2Hz,2H); 13 CNMR (75MHz, DMSO-d6): δ / ppm=171.92,171.75,169.33,136.57,136.24,130.43,127.44,127.32,123.05,121.75,121.72,119.88 ,119.83,118.84,118.76,111.15,111.12,107.55,104.93,67.80,56.52,55.60,42.15,38.13,31.85,28.66,27.43,22.62,22.35.

[0034] Example 7 Preparation of 3S-[2-(Boc-Trp-Leu)]-tetrahydro-β-carboline-3-carboxylic acid (2c)

[0035] Using the procedure of Example 3, 7.7 g (90%) of the title compound was obtained from 3.03 g (14 mmol) of 3S-tetrahydro-β-carboline-3-carboxylic acid and 5.84 g (14 mmol) of Boc-Trp-Leu as a colorless powder. ESI-MS: 616 [M+H] + ; 1H NMR (300MHz, DMSO-d6): δ / ppm=12.882(s,1H),11.660(s,1H),10.785(s,1H),8.320(s,1H),7.585(d,J=7.6Hz,1H),7.390(s,1H),7.350(d ,J=7.9Hz,1H),7.331(d,J=7.9Hz,1H),7.210(s,1H),7.211(d,J=7.9Hz,1H),7.062(t,J=7.2Hz,1H),6.981(t,J=7.2Hz,1H),6.932(t,J=7 .2Hz,1H),6.911(t,J=7.2Hz,1H),4.922(t,J=5.6Hz,1H),4.850(t,J1=6.1Hz,1H),4.445(m,1H),4.442(s,2H),3.332(d,J1=5.6Hz,2H),3 .042(d,J1=6.1Hz,2H),1.766(m,J1=6.1Hz,2H),1.483(m,J1=6.1Hz,1H),1.436(s,9H),0.913(d,J1=6.1Hz,3H),0.910(d,J1=6.1Hz,3H); 13 CNMR (75MHz, DMSO-d6): δ / ppm=171.93,171.75,169.34,155.89,136.52,1 36.24,130.45,127.42,127.32,123.32,121.71,121.66,119.95,119.76,1 18.84,118.76,111.15,111.12,109.73,104.95,79.45,67.88,59.50,52. 62,41.51,38.01,28.38,28.37,28.35,27.85,24.47,22.66,22.53,22.52.

[0036] Example 8 Preparation of 3S-[2-(Trp-Leu)]-tetrahydro-β-carboline-3-carboxylic acid (3c)

[0037] 4.2 g (90%) of the title compound was obtained as a colorless powder from 5.6 g (9.1 mmol) of 3S-[2-(Boc-Trp-Leu)]-tetrahydro-β-carboline-3-carboxylic acid using the procedure of Example 4. FT-ICR-MS: 516.2611 [M+H] + ; 1H NMR (300MHz, DMSO-d6): δ / ppm=12.981(s,1H),11.675(s,1H),10.793(s,1H),8.863(s,2H),8.323(s,1H),7.581(d,J=7.6Hz,1H),7. 352(d,J=7.9Hz,1H),7.333(d,J=7.9Hz,1H),7.216(s,1H),7.211(d,J=7.9Hz,1H),7.064(t,J=7.2Hz,1H),6.983(t,J=7.2Hz,1H),6 .935(t,J=7.2Hz,1H),6.912(t,J=7.2Hz,1H),4.851(t,J1=6.1Hz,1H),4.441(t,J=7.2Hz,2H),3.951(t,J1=5.6Hz,1H),3.093(t,J= 5.6Hz, 2H), 3.043 (d, J1 = 6.1Hz, 2H), 1.773 (m, J = 7.2Hz, 2H), 1.496 (m, J = 7.2Hz, 2H), 0.903 (d, J = 7.2Hz, 3H), 0.902 (d, J = 7.2Hz, 3H); 13 CNMR (75MHz, DMSO-d6): δ / ppm=171.93,171.72,169.30,136.55,136.22,130.41,127.42,127.33,123.03,121.73,121.71,119.85 ,119.81,118.83,118.79,111.14,111.11,107.51,104.95,67.82,56.72,52.60,41.15,38.11,24.45,27.41,22.63,22.56,22.55.

[0038] Example 9 Preparation of 3S-[2-(Boc-Trp-Ala)]-tetrahydro-β-carboline-3-carboxylic acid (2d)

[0039] Using the procedure of Example 3, 7.2 g (90%) of the title compound was obtained from 3.03 g (14 mmol) of 3S-tetrahydro-β-carboline-3-carboxylic acid and 5.25 g (14 mmol) of Boc-Trp-Ala as a colorless powder. ESI-MS: 574 [M+H] + ; 1H NMR (300MHz, DMSO-d6): δ / ppm=12.892(s,1H),11.670(s,1H),10.789(s,1H),8.322(s,1H),7.583(d,J=7.6Hz,1H),7.392 (s,1H),7.351(d,J=7.9Hz,1H),7.333(d,J=7.9Hz,1H),7.215(s,1H),7.213(d,J=7.9Hz,1H),7.063(t,J=7.2Hz,1H),6.98 2(t,J=7.2Hz,1H),6.931(t,J=7.2Hz,1H),6.910(t,J=7.2Hz,1H),4.920(t,J=5.6Hz,1H),4.852(t,J1=6.1Hz,1H),4.645 (m,J1=6.1Hz,1H),4.445(s,2H),3.334(d,J1=5.6Hz,2H),3.043(d,J1=6.1Hz,2H),1.466(m,J1=6.1Hz,3H),1.436(s,9H); 13 CNMR (75MHz, DMSO-d6): δ / ppm=171.95,171.72,169.94,155.86,136.50,136.25,130.41,127.43,127.31,123.02,121.73,121.69,119.85 ,119.78,118.82,118.73,111.16,111.11,109.70,104.93,79.55,67 .88,59.52,49.32,38.01,28.39,28.38,28.37,27.83,22.63,18.22.

[0040] Example 10 Preparation of 3S-[2-(Trp-Ala)]-tetrahydro-β-carboline-3-carboxylic acid (3d)

[0041] Using the procedure of Example 4, 4.22 g (91%) of the title compound was obtained from 5.6 g (9.8 mmol) of 3S-[2-(Boc-Trp-Ala)]-tetrahydro-β-carboline-3-carboxylic acid as a colorless solid. FT-ICR-MS: 474.2141 [M+H] + ; 1H NMR (300MHz, DMSO-d6): δ / ppm=12.881(s,1H),11.665(s,1H),10.790(s,1H),8.860(s,2H),8.321(s,1H),7.583(d,J= 7.6Hz,1H),7.354(d,J=7.9Hz,1H),7.330(d,J=7.9Hz,1H),7.210(s,1H),7.212(d,J=7.9Hz,1H),7.061(t,J=7.2Hz,1 H),6.980(t,J=7.2Hz,1H),6.932(t,J=7.2Hz,1H),6.910(t,J=7.2Hz,1H),4.853(t,J1=6.1Hz,1H),4.643(m,J1=5.1H z,1H),4.513(s,2H),3.955(t,J1=5.6Hz,1H),3.303(t,J=5.6Hz,2H),3.046(d,J1=6.1Hz,2H),1.476(d,J=5.1Hz,3H); 13 CNMR (75MHz, DMSO-d6): δ / ppm=171.83,171.62,169.90,136.52,136.23,130.43,127.44,127.34,123.06,121.75,121. 73,119.86,119.83,118.85,118.77,111.16,111.13,107.11,104.92,67.81,56.70,49.35,38.13,27.44,22.65,18.23.

[0042] Example 11 Evaluation of antiplatelet aggregation activity

[0043] Fresh porcine carotid artery blood was anticoagulated with 3.8% sodium citrate (1 / 9 by volume). Platelet-rich plasma (PRP) was obtained by centrifugation at 1000g for 10 minutes, and platelet-poor plasma (PPP) was obtained by centrifugation at 3000g for 10 minutes. Platelet-rich plasma was adjusted with platelet-poor plasma so that the number of platelets in platelet-rich plasma was suitable for the determination of antiplatelet aggregation activity. 3a-d was dissolved with normal saline. 0.24mL of adjusted platelet-rich plasma was added to the turbidity tube, and then 5μL of normal saline solution or normal saline solution of 3a-d (5μL, concentration of 0.1μM, 10μM, 15μM, 20μM) was added. The absorbance baseline was adjusted, and 5μL of normal saline solution of four induction factors was added to observe the maximum aggregation rate (Am) of platelets within 5 minutes. The four inducers are platelet activating factor (PAF, final concentration of 50μM), adenosine diphosphate (ADP, final concentration of 500μM), thrombin (TH, final concentration of 50IU / L) and arachidonic acid (AA, final concentration of 7.5mg / mL). The maximum aggregation rate is the value corresponding to the peak of the aggregation curve. Each concentration was measured 6 times in parallel to form a platelet aggregation curve. According to the platelet aggregation curve, the IC values ​​of 3a-d for inhibiting platelet aggregation induced by platelet activating factor, adenosine diphosphate, thrombin and arachidonic acid were determined. 50 (See Table 1). The data in Table 1 show that 3a-d inhibit PAF-induced platelet aggregation with an IC 50 The value is the smallest, which shows that 3a-d has excellent inhibitory effect on platelet activating factor (PAF) and is a selective inhibitor of PAF.

[0044] Table 1 IC of 3a-d for inhibiting platelet aggregation induced by four inducers 50 (mean ± SD, μM)

[0045] Compound ADP PAF TH AA 3a 25.24±0.32 2.30±0.08 16.50±0.22 26.58±0.30 3b 26.96±0.32 2.41±0.09 18.36±0.25 20.38±0.28 3c 24.13±0.31 2.22±0.07 14.42±0.20 24.32±0.29 3d 21.31±0.24 2.34±0.08 15.40±0.21 24.48±0.31

[0046] n=6

[0047] Example 12 Evaluation of Anti-arterial Thrombotic Activity

[0048] 1) Pull the polyethylene tube into a thin tube with an oblique end, with a fixed length of 10.0 cm, for cannulation of the right jugular vein (with a thicker diameter) and the left carotid artery (with a thinner diameter); the middle section of the polyethylene tube is fixed to a length of 8.0 cm, with the thrombus line pressed in the direction of carotid artery cannulation. The tube must be filled with heparin before cannulation.

[0049] 2) Male SD rats weighing 200±20g were acclimatized and fasted for one day before surgery. They were randomly divided into a saline group (blank control, oral dose of 0.3mL / 100g, 10 rats), an aspirin group (positive control, oral dose of 167μmol / kg, 10 rats), and a 3a-d saline solution group (oral dose of 0.1μmol / kg, 10 rats). 30 minutes after oral administration, the rats were anesthetized by intraperitoneal injection of 20% urethane solution (7mL / kg), and surgery began 2 minutes later. During the operation, the rats were placed supine on a fixed board, the neck skin was cut open, the right common carotid artery and the left jugular vein were separated, a precisely weighed silk thread was pressed down the blood vessels, the distal end was ligated, a small cut was made at the distal end of the vein, the cannula was inserted into the venous end, heparin was injected, and then the syringe for injecting heparin was removed, the thread was tied to fix it, and then the proximal end of the artery was clamped with an artery clamp, a small cut was made at the distal end of the artery, the artery end was ligated, and the artery clamp was released after the thread was fixed to establish an extracorporeal circulation bypass. After 15 minutes of circulation, the vein was cut first to observe whether the blood circulation was normal. If the blood circulation was normal, the silk thread with thrombus attached was removed from the arterial end, and the uncoagulated blood was absorbed with filter paper, and the silk thread with thrombus attached was accurately weighed. The weight of the thrombus was obtained by subtracting the weight of the silk thread from the weight of the silk thread, and the data were listed in Table 2. The thrombus weights in the table show that 3a-d effectively inhibited arterial thrombosis in rats at an oral dose of 0.1 μmol / kg (p<0.01 compared with saline and an oral dose of 16.7 μmol / kg aspirin). This was an unexpected technical effect.

[0050] Table 2 Effects of 3a-d on arterial thrombosis in rats

[0051]

[0052] a) p<0.01 compared with normal saline and oral dose of aspirin 16.7 μmol / kg; b) p>0.05 compared with normal saline; n=10.

Claims

1. A 2-Trp-AA-3S-tetrahydro-β-carboline-3-carboxylic acid compound of the following structure, wherein the amino acid represented by AA is selected from L-Glu residue, L-Lys residue, L-Leu residue or L-Ala residue, 2. A method for preparing the 2-Trp-AA-3S-tetrahydro-β-carboline-3-carboxylic acid compound of the structure described in claim 1, characterized in that: The method comprises the following steps: 1) preparing 3S-tetrahydro-β-carboline-3-carboxylic acid; 2) Preparation of Boc-AA-Trp; 3) preparing 2-Boc-Trp-AA-3S-tetrahydro-β-carboline-3-carboxylic acid; 4) preparing 2-Trp-AA-3S-tetrahydro-β-carboline-3-carboxylic acid, wherein AA is an L-Glu residue, an L-Lys residue, an L-Leu residue or an L-Ala residue.

3. Use of the 2-Trp-AA-3S-tetrahydro-β-carboline-3-carboxylic acid compound according to claim 1 in the preparation of a selective inhibitor of PAF-induced platelet aggregation.

4. Use of the 2-Trp-AA-3S-tetrahydro-β-carboline-3-carboxylic acid compound according to claim 1 in the preparation of an anti-arterial thrombotic agent.

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