Lignan compound as well as preparation method and application thereof

Abstract

The invention discloses a lignan compound as well as a preparation method and application thereof, and relates to the technical field of medicines. The invention particularly relates to four lignan small molecule compounds which are separated from amber and have the same plane structure, wherein the four lignan small molecule compounds comprise two pairs of enantiomers (+)-6 / (-)-6 and (+)-7 / (-)-7. The structure of the compound is as follows: # imgabs0 #. In a renal fibrosis model experiment, the lignan compound provided by the invention can inhibit expression of proteins such as alpha SMA protein, I-type collagen and fibronectin related to renal fibrosis in NRK-52E cells induced by transforming growth factor-beta1; therefore, the lignan compound provided by the invention has the application of preparing the medicine for preventing and treating renal fibrosis.

Description

Technical Field

[0001] The present invention relates to the field of pharmaceutical technology, and in particular to a lignan compound, a preparation method thereof and an application thereof. Background Art

[0002] Amber is a transparent fossilized organism, a fossilized resin of plants such as Pinaceae, Caesalpiniaceae, and Araucariaceae. The resin drips and is buried underground for tens of millions of years. Under the action of pressure and heat, it petrifies and forms. Some contain small insects such as bees inside, which is extremely beautiful. Most amber is petrified from the resin of pine family plants, so it is also called "fossilized rosin". The production of amber is mainly concentrated in Russia, Myanmar, and provinces such as Henan, Liaoning, and Yunnan in China. The main chemical components of amber are resin and volatile oil. Volatile oils include monoterpenes, sesquiterpenes, diterpenes, and aromatic compounds. The earliest record of the medicinal use of amber dates back to ancient times. The earliest medicine only used ingredients that could be obtained from nature: plants, animals, and minerals. As a traditional Chinese medicine, amber has been widely used to treat various diseases since ancient times. In ancient books, amber was described as calming the mind, promoting water metabolism and removing blood stasis, and other benefits. Several studies have shown that amber has antibacterial, anti-inflammatory, anti-allergic and other effects.

[0003] Renal fibrosis is a common pathological manifestation of the progression of various chronic kidney diseases (CKD) to end-stage renal disease (ESRD). So far, no specific drug that can reverse renal fibrosis has been found. Clinically, the intervention measures to delay renal fibrosis are the key to protecting renal function. Effective intervention measures can delay the progression rate of renal fibrosis and delay renal replacement therapy to the greatest extent. Currently, the drugs used to treat renal fibrosis mainly include hormones, immunosuppressants, angiotensin-converting enzyme inhibitors, angiotensin II receptor antagonist antihypertensive drugs, and various traditional Chinese medicines with kidney-protecting effects.

[0004] Further exploring the effects of the components in amber on renal fibrosis helps to develop new uses of amber small molecule compounds. Summary of the Invention

[0005] In view of the above deficiencies of the prior art, the object of the present invention is to provide two meso-lignan small molecule compounds, a preparation method thereof and an application thereof, aiming to provide a novel small molecule compound, which can prevent and treat renal fibrosis by inhibiting the expression of proteins related to renal fibrosis such as αSMA protein, type I collagen and fibronectin in NRK-52E cells induced by transforming growth factor-β1 (TGF-β1). The introduction is as follows:

[0006] On the one hand, the present invention provides a lignan compound or a salt thereof, having the structure shown below:

[0007]

[0008] Specifically, the lignan compound includes two compounds 6 and 7, named Succignans A (compound 6) and Succignans B (compound 7), which are light yellow oils and both contain enantiomers. After further separation, 4 stereoisomers are obtained, specifically including 2 pairs of enantiomers (+)-6 / (-)-6 and (+)-7 / (-)-7.

[0009] The structural identification results of the compounds obtained in the present invention are as follows:

[0010] The high-resolution electrospray ionization mass spectrometry HRESIMS of compound 6 shows: 621.2076 [M+Na] + (the calculated value is 621.2095), and the high-resolution electrospray ionization mass spectrometry HRESIMS of compound 7 shows: 621.2074 [M+Na] + (the calculated value is 621.2095). Compounds 6 and 7 have the same molecular formula as C 35 H 34 O 9 and are both light yellow oils.

[0011] It should be noted that any process that traces and obtains the lignan compounds described in the present invention using the molecular weight as a clue is within the protection scope of the present invention.

[0012] Specifically, the lignan compounds are extracted and separated from amber or obtained by artificial synthesis.

[0013] On the other hand, the present invention also provides a preparation method of the lignan compound or a salt thereof, including the following steps:

[0014] ① Reflux and extract amber with dichloromethane at room temperature, combine the extracts and concentrate to obtain a crude extract;

[0015] ② Subject the crude extract to gradient elution on an MCI CHP 20P chromatographic column with water and a mixed solvent of 85-100 v% methanol / isopropanol to obtain 9 fractions Fr.1-Fr.9;

[0016] Subject Fr.6 to gradient elution on an MCI CHP 20P chromatographic column with water and a mixed solvent of 88-100 v% methanol / isopropanol to obtain 7 fractions Fr.6.1-Fr.6.7;

[0017] Fr.6.6 was subjected to gradient elution chromatography on a silica gel column using a dichloromethane / methanol system to obtain 14 fractions, namely Fr.6.6.1 - Fr.6.6.9 and Fr.6.6.A - Fr.6.6.E;

[0018] Fr.6.6.5 was subjected to reverse-phase chromatography separation on an RP-18 column using an 86 - 100 v% methanol / water solution to obtain 7 components, namely Fr.6.6.5.1 - Fr.6.6.5.7;

[0019] ③ Using acetonitrile - water as the mobile phase, Fr6.6.5.7 was further purified by semi-preparative HPLC to obtain Compound 6 and Compound 7; chiral resolution of Compound 6 and 7 gave Compound (+)-6 / (-)-6 and Compound (+)-7 / (-)-7.

[0020] A further technical solution thereof is that in step ①, the dosage ratio of succinic acid to dichloromethane is 1 kg: 3 - 8 L; reflux extraction is carried out 2 - 3 times, and the extraction time for each time is 8 - 36 hours.

[0021] A further technical solution thereof is that in step ②, in the methanol / isopropanol mixed solvent, the volume ratio of methanol to isopropanol is 8:1 - 20:1; in the dichloromethane / methanol system, the volume ratio of dichloromethane to methanol is 100:1 - 5:1.

[0022] A further technical solution thereof is that in step ③, the mobile phase is a 60 - 85 v% acetonitrile aqueous solution.

[0023] On the other hand, the present invention provides the use of the lignan compound or its salt thereof in the preparation of a drug for inhibiting the expression of αSMA protein, type I collagen, and fibronectin related to renal fibrosis in NRK-52E cells induced by transforming growth factor-β1.

[0024] On another hand, the present invention provides the use of the lignan compound or its salt thereof in the preparation of a drug for treating and preventing renal fibrosis.

[0025] On yet another hand, the present invention provides a pharmaceutical composition for treating and preventing renal fibrosis, and the pharmaceutical composition comprises the lignan compound or its salt thereof as described above.

[0026] Specifically, the pharmaceutical composition further comprises a pharmaceutically acceptable carrier and / or adjuvant. That is to say, a pharmaceutical composition containing the lignan compound or its salt thereof of the present invention as an active ingredient and a conventional pharmaceutical excipient or adjuvant or carrier is also included in the present invention.

[0027] The pharmaceutical composition of the present invention uses the lignan compounds 6 and 7 as active ingredients, without excluding changes in the formulation system and administration method, derivatives obtained by simple chemical modification and adjustment of the above compounds, medicinal salts, combination of multiple compounds, and combination with multiple degradants, etc.

[0028] Specifically, the pharmaceutically acceptable salts provided by the present invention can be: sodium salt, potassium salt, ammonium salt, amino acid salt, lactate, hydrochloride, phosphate, acetate, malate, citrate or aspartate, etc. The present invention does not make specific limitations on pharmaceutical salts.

[0029] In the present invention, the lignan compounds 6 and 7 of the present invention can be formulated as active ingredients in a non-toxic, inert and pharmaceutically acceptable carrier medium; the prepared drug can be administered through conventional routes, including but not limited to oral, intramuscular, intraperitoneal, intravenous, subcutaneous, intradermal, or topical administration.

[0030] When the dosage form of the pharmaceutical composition of the present invention is a drug for oral administration, it contains a safe and effective amount of the lignan compounds 6 and 7 of the present invention and a pharmaceutically acceptable carrier and / or adjuvant. The drug for oral administration can be made into common dosage forms such as tablets, pills, powders, granules, capsules, emulsions, syrups, ointments, suppositories, etc. In the present invention, no specific limitations are made on the carrier and / or adjuvant.

[0031] The pharmaceutical composition of the present invention can also be made into an injection, which can be made into an injection with water for injection, physiological saline, or glucose solution under aseptic conditions. The above injection can be prepared by conventional methods.

[0032] Compared with the prior art, the technical effects that the present invention can achieve include:

[0033] The present invention provides two lignan meso compounds, their preparation methods and applications. In the present invention, two lignan meso compounds are extracted and separated from amber with dichloromethane, named Succignans A (compound 6) and Succignans B (compound 7). These are novel compounds first isolated and identified from amber, and the present invention also discloses for the first time the method for extracting and separating the new compounds Succignans A and Succignans B from amber. Through structural identification, the small molecule compounds are novel meso lignan compounds, which have a certain effect in anti-renal fibrosis.

[0034] Specifically, in the renal fibrosis model experiment, compounds Succignans A and Succignans B can inhibit the expression of proteins related to renal fibrosis, such as αSMA protein, type I collagen, and fibronectin, in NRK-52E cells induced by transforming growth factor-β1 (TGF-β1). This indicates that the compounds Succignans A and Succignans B provided by the present invention have the use for preparing drugs for preventing and treating renal fibrosis. Therefore, the novel compounds Succignans A and Succignans B isolated from amber for the first time by the present invention have a new use for preparing drugs for preventing and treating renal fibrosis. Description of the Drawings

[0035] Figure 1 1H NMR spectrum of compound Succignans A prepared in Example 1 of the present invention.

[0036] Figure 2 13C NMR spectrum of compound Succignans A prepared in Example 1 of the present invention.

[0037] Figure 3 1H NMR spectrum of compound Succignans B prepared in Example 1 of the present invention.

[0038] Figure 4 13C NMR spectrum of compound Succignans B prepared in Example 1 of the present invention.

[0039] Figure 5 Experimental results showing that compounds Succignans A and Succignans B have no obvious cytotoxicity at 20 μM in Example 2 of the present invention.

[0040] Figure 6 Experimental results showing that compounds Succignans A and Succignans B inhibit the expression of proteins related to renal fibrosis, such as αSMA protein, type I collagen, and fibronectin, in NRK-52E cells induced by transforming growth factor-β1 (TGF-β1) in Example 2 of the present invention. Detailed Embodiments

[0041] Next, the technical solutions in the embodiments will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments to be described below are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts shall fall within the protection scope of the present invention.

[0042] It should be understood that the terms used in the specification of the embodiments of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the embodiments of the present invention. As used in the specification of the embodiments of the present invention and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include the plural forms.

[0043] Example 1

[0044] The embodiments of the present invention provide a lignan compound or a salt thereof, having the following structure:

[0045]

[0046] The lignan compounds specifically include two compounds, namely Compound 6 and Compound 7, named Succignans A (Compound 6) and Succignans B (Compound 7).

[0047] This embodiment also provides a preparation method of the above compound, including the following steps:

[0048] S100. Provide amber raw material (29 kg);

[0049] S200. Crush the amber raw material and extract it twice with dichloromethane (150 L, 24 hours), combine the extraction solutions and concentrate to obtain a crude extract (5.1 kg);

[0050] S300. Perform the first column chromatography separation on the crude extract, through an MCI CHP 20P chromatographic column, and perform gradient elution with water and a mixed solvent of 85 - 100 v% methanol / isopropanol = 10:1 to obtain 9 fraction components (Fr.1 - Fr.9);

[0051] S400. Perform the second column chromatography separation on the Fr.6 (299.8 g), through an MCI CHP 20P chromatographic column, and perform gradient elution with water and a mixed solvent of 88 - 100 v% methanol / isopropanol = 15:1 to obtain 7 components, namely (Fr.6.1 - Fr.6.7);

[0052] S500. Perform the third column chromatography separation on the Fr.6.6 (67.4 g), and perform gradient elution on a silica gel column with a dichloromethane / methanol system (100:1 - 5:1) to obtain 14 fraction components, namely (Fr.6.6.1 - Fr.6.6.9 and Fr.6.6.A - Fr.6.6.E);

[0053] S600. The Fr.6.6.5 (8.0 g) was subjected to a fourth column chromatography separation and purified by reverse-phase passing through an RP-18 column with 86 - 100 v% methanol / water. After elution, 7 fractions were obtained, namely (Fr.6.6.5.1 - Fr.6.6.5.7).

[0054] S700. The Fr6.6.5.7 (541.0 mg) was purified by semi-preparative HPLC (mobile phase: 80 v% acetonitrile / water, flow rate 3.0 mL / min), obtaining Compound 6 (15.5 mg, tR = 18.2 min) and Compound 7 (27.1 mg, tR = 16.5 min).

[0055] S800. The racemic compounds 6 and 7 were separated into their respective enantiomers by chiral high-performance liquid chromatography, (-)-6 (4.8 mg, tR = 23.0 min) and (+)-6 (4.6 mg, tR = 25.0 min) (mobile phase: 60 v% acetonitrile / water, flow rate 1.0 mL / min); (-)-7 (3.9 mg, tR = 21.3 min) and (+)-7 (3.7 mg, tR = 23.4 min) (mobile phase: 60 v% acetonitrile / water, flow rate 1.0 mL / min).

[0056] The structures of the prepared Compounds 6 and 7 were identified, and the results are as follows:

[0057]

[0058] Compound 6, a pale yellow oil, was named Compound Succignans A. HRESIMS m / z 621.2076 [M+Na] + (calcd for C 35 H 34 O 9 Na, 621.2095); 1 H NMR (600 MHz, CD 3OD) δ 8.08 (dd, J = 8.3, 1.4, H-2″′, 6″′, 2H), 7.84 (dd, J = 8.3, 1.4, H-2′, 6′, 2H), 7.56 (t, H-4″′, 1H), 7.49 (t, J = 7.4, H-4′, 1H), 7.45 (t, H-3″′, 5″′, 2H), 7.36 (t, H-3′, 5′, 2H), 6.97 (d, J = 1.6, H-2″, 1H), 6.91 (dd, J = 8.1, 1.6, H-6″, 1H), 6.89 (d, J = 8.1, H-5″, 1H), 6.85 (d, J = 1.1, H-2, 1H), 6.84 (dd, J = 8.1, 1.1, H-6, 1H), 6.75 (d, J = 8.1, H-5, 1H), 6.63 (dd, J = 15.8, 1.3, H-7, 1H), 6.25 (dt, J = 15.8, 6.5, H-8, 1H), 4.96 (dd, J = 6.5, 1.3, H-9, 2H), 4.65 (overlap, H-9″, 8″, 3H), 4.48 (m, H-7″, H), 3.85 (s, OCH 3 , 3H), 3.70 (s, OCH 3 , 3H), 3.31 (s, OCH 3 , 3H); 13 C NMR (150 MHz, CD 3 OD) δ 131.3 (s, C-1), 110.1 (s, C-2), 146.7 (s, C-3), 148.2 (s, C-4), 118.7 (s, C-5), 119.9 (s, C-6), 134.3 (s, C-7), 122.0 (s, C-8), 65.7 (s, C-9), 130.0 (s, C-1′), 129.7 (s, C-2′, 6′), 128.3 (s, C-3′, 5′), 133.0 (s, C-4′), 166.5 (s, C-7′), 130.0 (s, C-1″), 109.9 (s, C-2″), 151.0 (s, C-3″), 145.6 (s, C-4″), 114.1 (s, C-5″), 121.0 (s, C-6″), 82.9 (s, C-7″), 82.4 (s, C-8″), 64.5 (s, C-9″), 130.3 (s, C-1″′), 129.7 (s, C-2″′, 6″′), 128.5 (s, C-3″′, 5″′), 133.1 (s, C-4″′), 166.6 (s, C-7″′), 56.0 (3-OCH 3 ), 55.8 (3″-OCH 3 ), 57.3 (7″-OCH3 )。

[0059] Compound 7, a pale yellow oil, was named Compound Succignans B. HRESIMS m / z 621.2076 [M+Na] + (calcd for C 35 H 34 O 9 Na, 621.2095); 1 1H NMR (600 MHz, CD 3 OD) δ 8.08 (dd, J = 8.3, 1.4, H-2″′, 6″′, 2H), 7.85 (dd, J = 8.3, 1.4, H-2′, 6′, 2H), 7.57 (t, H-4″′, 1H), 7.50 (t, J = 7.4, H-4′, 1H), 7.45 (t, J = 7.7, H-3″′, 5″′, 2H), 7.37 (t, J = 7.7, H-3′, 5′, 2H), 6.98 (d, J = 8.1, H-5, 1H), 6.96 (d, J = 1.1, H-2″, 1H), 6.90 (dd, J = 8.1, 1.1, H-6, 1H), 6.89 (d, J = 8.1, H-5″, 1H), 6.88 (dd, overlap, H-2, 6″, 2H), 6.66 (dd, J = 15.7, 1.3, H-7, 1H), 6.27 (dt, J = 15.7, 6.5, H-8, 1H), 4.96 (dd, J = 6.5, 1.3, H-9, 2H), 4.65 (td, J = 6.0, 3.9, H-8″, 1H), 4.51 (d, J = 6.0, H-7″, H), 4.43 (dd, J = 11.8, 3.9, Ha-9″, H), 4.32 (dd, J = 11.8, 6.0, Hb-9″, H), 3.82 (s, OCH 3 , 3H), 3.74 (s, OCH 3 , 3H), 3.32 (s, OCH 3 , 3H); 13 13C NMR (150 MHz, CD 3OD) δ 131.1 (s, C-1), 110.0 (s, C-2), 146.9 (s, C-3), 148.7 (s, C-4), 118.3 (s, C-5), 120.0 (s, C-6), 134.4 (s, C-7), 121.9 (s, C-8), 65.8 (s, C-9), 129.6 (s, C-1′), 129.7 (s, C-2′, 6′), 128.4 (s, C-3′, 5′), 133.1 (s, C-4′), 166.3 (s, C-7′), 130.3 (s, C-1″), 109.8 (s, C-2″), 150.9 (s, C-3″), 145.8 (s, C-4″), 114.3 (s, C-5″), 120.8 (s, C-6″), 83.6 (s, C-7″), 82.2 (s, C-8″), 64.5 (s, C-9″), 129.9 (s, C-1″′), 129.7 (s, C-2″′, 6″′), 128.5 (s, C-3″′, 5″′), 133.1 (s, C-4″′), 166.6 (s, C-7″′), 56.0 (3-OCH 3 ), 55.8 (3″-OCH 3 ), 57.3 (7″-OCH 3 ).

[0060] The nuclear magnetic resonance hydrogen spectrum of compound Succignans A (compound 6) is as shown in Figure 1 , and the carbon spectrum is as shown in Figure 2 . The nuclear magnetic resonance hydrogen spectrum of compound Succignans B (compound 7) is as shown in Figure 3 , and the carbon spectrum is as shown in Figure 4 .

[0061] Example 2

[0062] Compound Succignans A (compound 6) and compound Succignans B (compound 7) were tested for DNA damage repair efficiency.

[0063] In this example, the cell culture method was as follows: Normal rat kidney proximal tubular epithelial cells (NRK-52E) (Cell Bank of Shanghai Institute of Chinese Academy of Sciences, China) were cultured in high-glucose DMEM (C11995500BT, Gibco, USA, 10% fetal bovine serum, Gibco, USA, 2094468CP) medium at 37 °C in a humid environment containing 5% carbon dioxide, and 100 U / mL penicillin and 100 μg / mL streptomycin were added.

[0064] The method for measuring cell viability was as follows: NRK-52E cells (5×10 4Cells (at a density of 5×10 cells / mL) were seeded into 96-well plates containing complete DMEM medium and incubated for 24 h. Then, the cells were treated with different concentrations of Compound 6, Compound 7, or DMSO (control) for 48 h. Subsequently, Cell Counting Kit-8 (CCK-8, Beyotime, Shanghai) was added to each well and incubated at 37 °C for 1 h. The absorbance of each well was measured at 450 nm using a microplate reader (BioTek, USA).

[0065] The method for Western blot analysis was as follows: NRK-52E cells were seeded into 6-well plates at a density of 2 mL / well (5×10 4 cells / mL) and incubated overnight. When starved for 6 h, the cells were treated with different concentrations of Compound 6, Compound 7, or DMSO in DMEM containing 4% FBS for 48 h. Additionally, recombinant TGF-β1 (5 ng / mL) was added to each plate to induce cell fibrosis. Total protein was extracted from the cell lines using radioimmunoprecipitation assay (RIPA) buffer (Beyotime, China) containing a protease mixture (Roche, Germany). Then, a BCA assay (Thermo Fisher Scientific, USA) was applied to quantify the protein samples. Western blot analysis was performed as described previously. In this study, the primary antibodies used were as follows: anti-fibronectin (dilution 1:1000; ab 268020; Abcam), anti-collagen type I (dilution 1:1000; ab 270993; Abcam), anti-αSMA (dilution 1:1000; A2547; Sigma), and anti-GAPDH (dilution 1:2000; sc 365062; Santa Cruz).

[0066] All data were analyzed using IBM SPSS Statistics 22 and presented as mean ± SEM. One-way ANOVA was used for between-group comparisons, followed by the Student-Newman-Kuels test. A P value < 0.05 was considered statistically significant. The detailed statistical tests were described in the legend of each experiment.

[0067] Excessive extracellular matrix (ECM) deposition is an invariant feature of chronic kidney disease (CKD). Additionally, extensive studies have described TGF-β1 as the most important pathogenic factor associated with glomerular and tubulointerstitial fibrosis. Therefore, in this study, we used TGF-β1-stimulated NRK-52E cells to induce fibrosis and subsequently detected ECM proteins such as fibronectin, collagen type I, and α-SMA to evaluate the severity of fibrosis.

[0068] The CCK-8 assay was performed to exclude the possibility that the biological effects of the compounds were caused by cytotoxicity. The results were asFigure 5 It was shown that these compounds at a concentration of 20 μM or less had no obvious cytotoxicity. Subsequently, dose-response studies showed that as the concentrations of compounds (-)-6 and (+)-6 increased, their anti-fibrotic activities seemed to be more prominent (results are shown in Figure 6 A - D). However, the effects of compounds (-)-7 and (+)-7 on fibronectin expression did not show a dose-response relationship, but they could inhibit the expression of α-SMA, type I collagen, and fibronectin at lower concentrations (results are shown in Figure 6 E - H).

[0069] In summary, compounds 6 and 7 isolated from amber in the present invention can limit the expression of α-SMA, type I collagen, and fibronectin in TGF-β1-induced NRK-52E cells, indicating that compounds 6 and 7 have the potential for treating renal fibrosis and can be used to prepare drugs for preventing and treating renal fibrosis.

[0070] Example 3

[0071] This example provides a pharmaceutical composition for preparing drugs for preventing and treating renal fibrosis. The compound prepared in Example 1 is added with an injection solvent by a conventional method, finely filtered, and then made into an injection after filling and sterilization.

[0072] Example 4

[0073] This example provides a pharmaceutical composition for preparing drugs for preventing and treating renal fibrosis. The compound prepared in Example 1 is dissolved in sterile water for injection, filtered through a sterile funnel, dispensed, and then freeze-dried at low temperature and aseptically sealed to obtain a powder injection.

[0074] Example 5

[0075] This example provides a pharmaceutical composition for preparing drugs for preventing and treating renal fibrosis. The compound prepared in Example 1 can be made into tablets or capsules by a conventional method with various pharmaceutical excipients. Using the compound in Example 1 as the drug active ingredient and several conventional excipients as the excipient components for preparing combined drug tablets or capsules, samples containing 10 - 300 mg of the drug component per tablet or per capsule are prepared according to the conventional method.

[0076] In the above examples, the descriptions of each example have their own focuses. For parts not described in detail in a certain example, reference can be made to the relevant descriptions of other examples.

[0077] As described above, the specific implementation manners of the present invention are provided, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of various equivalent modifications or substitutions, and these modifications or substitutions should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A lignan compound or a salt thereof, characterized in that, it has the structure shown as follows:

2. The lignan compound or a salt thereof according to claim 1, characterized in that, the lignan compound is extracted and isolated from amber or obtained by artificial synthesis.

3. A method for preparing the lignan compound or a salt thereof according to claim 1, characterized in that, it comprises the following steps: ① Reflux and extract amber with dichloromethane at room temperature, combine the extracts and concentrate to obtain a crude extract; ② Subject the crude extract to gradient elution on an MCI CHP 20P chromatographic column with water and a mixed solvent of methanol / isopropanol at 85 - 100 v% to obtain 9 fractions Fr.1 - Fr.9; Subject Fr.6 to gradient elution on an MCI CHP 20P chromatographic column with water and a mixed solvent of methanol / isopropanol at 88 - 100 v% to obtain 7 fractions Fr.6.1 - Fr.6.7; Subject Fr.6.6 to gradient elution chromatography on a silica gel column with a dichloromethane / methanol system to obtain 14 fractions Fr.6.6.1 - Fr.6.6.9 and Fr.6.6.A - Fr.6.6.E; Subject Fr.6.6.5 to reverse phase chromatography separation on an RP - 18 column with a methanol / water solution at 86 - 100 v% to obtain 7 fractions Fr.6.6.5.1 - Fr.6.6.5.7; ③ Using acetonitrile - water as the mobile phase, further purify Fr6.6.5.7 by semi - preparative HPLC to obtain compound 6 and compound 7; perform chiral resolution on compound 6 and 7 to obtain compound (+)-6 / (-)-6 and (+)-7 / (-)-7.

4. The preparation method according to claim 3, characterized in that, in step ①, the dosage ratio of amber to dichloromethane is 1 kg: 3 - 8 L; reflux and extract 2 - 3 times, and the extraction time for each time is 8 - 36 hours.

5. The preparation method according to claim 3, characterized in that, in step ②, in the methanol / isopropanol mixed solvent, the volume ratio of methanol to isopropanol is 8:1 - 20:1; in the dichloromethane / methanol system, the volume ratio of dichloromethane to methanol is 100:1 - 5:

1.

6. The preparation method according to claim 3, characterized in that, in step ③, the mobile phase is an acetonitrile aqueous solution at 60 - 85 v%.

7. Use of the lignan compound or a salt thereof according to claim 1 or 2, or the lignan compound prepared by the preparation method according to any one of claims 3 - 5 in the preparation of a drug for inhibiting the expression of α - SMA protein, type I collagen and fibronectin related to renal fibrosis in NRK - 52E cells induced by transforming growth factor - β1.

8. Use of the lignan compound or a salt thereof according to claim 1 or 2, or the lignan compound prepared by the preparation method according to any one of claims 3 - 5 in the preparation of a drug for treating and preventing renal fibrosis.

9. A pharmaceutical composition for treating and preventing renal fibrosis, characterized in that, Comprising the lignan compound or its salt as described in claim 1 or 2, or the lignan compound prepared by the preparation method as described in any one of claims 3 - 5.

10. The pharmaceutical composition as described in claim 9, characterized in that the pharmaceutical composition further comprises a pharmaceutically acceptable carrier and / or adjuvant.

Images