Lignan compound and application thereof

Abstract

The invention belongs to the technical field of compounds, and discloses lignan compounds and application thereof. The lignan compound is obtained by being separated from piper mongolicum. The lignan compound is a compound A with a structure as shown in a formula 1 or a compound B with a structure as shown in a formula 2; according to the method, the alcohol extract of the pepper mongolica is guided and separated through a GNPS molecular network strategy, a new monomeric compound is quickly found, repeated separation of a traditional method is avoided, a lignan enrichment part is accurately found, the time and reagent cost is reduced, and resource consumption is reduced; the compound has a good inhibition effect on BPH cells.

Description

Technical Field

[0001] The present invention belongs to the technical field of compounds, and relates to lignan compounds and their applications. Specifically, it relates to two new lignan compounds isolated from the medicinal plant Peperomia heyneana Miq. and their applications in the preparation of drugs for treating benign prostatic hyperplasia. Background Art

[0002] Benign prostatic hyperplasia (BPH) is a common disease in elderly men, and its incidence gradually increases with age, characterized by hyperplasia symptoms of the prostate and urinary tract. The enlarged prostate can cause disorders of the urinary system, such as frequent urination and urgency, bringing physical and mental pain to patients and seriously affecting the quality of life of patients. Although there are many drugs such as 5α-reductase inhibitors and α-blockers available for the treatment of BPH, these synthetic inhibitors are not only expensive but also have certain side effects, such as decreased libido and gynecomastia in men. Therefore, it is crucial to find highly effective and low-toxic drugs from natural plants.

[0003] The genus Peperomia Ruiz & Pav. contains approximately 1,600 species and is one of the largest genera of angiosperms, usually consisting of perennial herbs. Its species are pantropically distributed, with the greatest biodiversity in the Neotropics. Studies have shown that this genus has estrogenic activity, antibacterial and anti-trypanosomal activity, anti-inflammatory and anti-cancer activity, and anti-tumor activity. Plants of the genus Peperomia are rich in a variety of structurally similar secondary metabolites (such as terpenoids, flavonoids, alkaloids, phenylpropanoids), and their polarity, solubility, and molecular weight are close, resulting in severe peak overlap during chromatographic separation and difficulty in effectively separating target components. Moreover, the content of natural substances in plants is very low, and it is extremely difficult to detect and separate them by conventional methods, with a high time cost.

[0004] The two new lignan compounds and their activities involved in the present invention have not been reported in patents or literature so far. Summary of the Invention

[0005] In order to overcome the deficiencies of the prior art, the present invention provides lignan compounds and their applications, and provides brand-new lignan compounds; the compounds have good inhibitory effects on BPH cells, and at the same time overcome the disadvantages of complex traditional extraction and separation methods, long time consumption, and large solvent loss.

[0006] The above object of the present invention is achieved by the following technical solutions:

[0007] The first object of the present invention is to claim lignan compounds, and the lignan compounds are compound A having the structure shown in Formula 1 or compound B having the structure shown in Formula 2;

[0008]

[0009] The above lignan compounds were isolated from *Peperomia heyneana* Miq. *Peperomia heyneana* Miq. was collected in Mengzi City, Yunnan Province in November 2022.

[0010] The present invention also claims the preparation method of the above lignan compounds. Using the dried whole herb of *Peperomia heyneana* Miq. as raw material, after pulverization, it is refluxed and extracted 3 - 4 times with 95% (v / v) ethanol for 3 - 4 h each time. The extraction part is separated and purified by silica gel column chromatography, medium pressure column chromatography, preparative and semi - preparative high - performance liquid chromatography; the ethanol extracts of plants in the genus *Peperomia* are directionally separated by the GNPS molecular network strategy, and lignan compounds are quickly discovered and obtained from them and their weight is enriched.

[0011] The conditions for separating and purifying compound A by preparative and semi - preparative high - performance liquid chromatography are as follows: using octadecylsilane - bonded silica gel as the stationary phase, the mobile phase is a methanol - water mixed solvent with a ratio of 35:65, the flow rate is 3 mL / min, and the detection wavelength of the ultraviolet detector is 210 nm.

[0012] The conditions for separating and purifying compound B by preparative and semi - preparative high - performance liquid chromatography are as follows: using octadecylsilane - bonded silica gel as the stationary phase, the mobile phase is an acetonitrile - water mixed solvent with a ratio of 48:52, the flow rate is 3 mL / min, and the detection wavelength of the ultraviolet detector is 210 nm.

[0013] The preparation method of the above lignan compounds is specifically as follows:

[0014] S1. Weigh 1 kg of the dried whole herb of *Peperomia heyneana* Miq., after pulverization, reflux and extract it 3 - 4 times with 3 L of 95% (v / v) ethanol (the solid - liquid ratio is 1:3) for 3 - 4 h each time. After filtering off the residue, it is concentrated under reduced pressure to obtain an ethanol extract paste.

[0015] S2. The ethanol extract paste is fully suspended with hot deionized water, and successively extracted 3 - 5 times with petroleum ether, ethyl acetate, and n - butanol saturated with water in equal volume ratios as extractants. After the extraction liquid is colorless, the extraction liquids are combined and concentrated under reduced pressure to obtain an ethyl acetate extract.

[0016] S3. The ethyl acetate layer extract was subjected to gradient elution with a dichloromethane-methanol mixed solvent with a volume ratio of 100:0 - 0:100. The elution fractions were detected and tracked according to the results of thin-layer chromatography. The same fractions were combined. The secondary mass spectrometry data of the samples were collected for the fractions by LC-MS / MS method. The original data files were converted into data files in mzXML, mzML, and mgf formats and imported into the GNPS database to establish a molecular network. The molecular network diagram was analyzed using the GNPS data platform to obtain known compounds. Then, based on the correlation between nodes in the molecular network diagram, the similarities and differences in the mass spectrometry data between related nodes were compared to find the fractions enriched in new compounds, and fractions 4 and 5 were discovered.

[0017] S4. Fraction 4 was subjected to gradient elution with a petroleum ether-ethyl acetate mixed solvent with a volume ratio of 50:1 - 1:5. Octadecylsilyl-bonded silica gel was used as the stationary phase, the mobile phase was a methanol-water mixed solvent with a volume ratio of 35:65, the flow rate was 3 mL / min, and the detection wavelength of the ultraviolet detector was 210 nm for further separation and purification, and finally compound A shown in Formula 1 was obtained;

[0018] S5. Fraction 5 was subjected to gradient elution with a petroleum ether-ethyl acetate mixed solvent with a volume ratio of 20:1 - 1:2, and was separated again using Sephadex LH20, eluted with a dichloromethane-methanol mixed solvent with a volume ratio of 1:1. Octadecylsilyl-bonded silica gel was used as the stationary phase, the mobile phase was an acetonitrile-water mixed solvent with a volume ratio of 48:52, the flow rate was 3 mL / min, and the detection wavelength of the ultraviolet detector was 210 nm for further separation and purification, and finally compound B shown in Formula 2 was obtained.

[0019] The present invention also claims the application of the lignan compounds prepared by the above-mentioned preparation method of lignan compounds in the preparation of drugs for treating benign prostatic hyperplasia.

[0020] The beneficial effects of the present invention compared with the prior art are as follows: By using the GNPS molecular network strategy for guiding the separation of the ethanol extract of Piper szemaoense, new monomer compounds can be quickly found. This method avoids repeated separation by traditional methods, accurately finds the parts enriched in lignans, reduces time and reagent costs, and reduces resource consumption; Compounds A and B obtained in the present invention and their activities have not been reported in other patents and literatures. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a process schematic diagram for the preparation of the lignan compounds of the present invention.

[0022] Figure 2 It is the measured and calculated ECD diagrams of compound A prepared in Example 1 of the present invention.

[0023] Figure 3HRESIMS spectrum of compound A prepared in Example 1 of the present invention.

[0024] Figure 4 1H NMR spectrum of compound A prepared in Example 1 of the present invention.

[0025] Figure 5 13C NMR spectrum of compound A prepared in Example 1 of the present invention.

[0026] Figure 6 HSQC spectrum of compound A prepared in Example 1 of the present invention.

[0027] Figure 7 HMBC spectrum of compound A prepared in Example 1 of the present invention.

[0028] Figure 8 UV spectrum of compound A prepared in Example 1 of the present invention.

[0029] Figure 9 CD spectrum of compound A prepared in Example 1 of the present invention.

[0030] Figure 10 HRESIMS spectrum of compound B prepared in Example 1 of the present invention.

[0031] Figure 11 1H NMR spectrum of compound B prepared in Example 1 of the present invention.

[0032] Figure 12 13C NMR spectrum of compound B prepared in Example 1 of the present invention.

[0033] Figure 13 HSQC spectrum of compound B prepared in Example 1 of the present invention.

[0034] Figure 14 HMBC spectrum of compound B prepared in Example 1 of the present invention.

[0035] Figure 15 NOESY spectrum of compound B prepared in Example 1 of the present invention.

[0036] Figure 16 UV spectrum of compound B prepared in Example 1 of the present invention.

[0037] Figure 17 HMBC correlation spectrum of compound A prepared in Example 1 of the present invention.

[0038] Figure 18 HMBC correlation spectrum of compound B prepared in Example 1 of the present invention.

[0039] Figure 19 NOESY correlation spectrum of compound B prepared in Example 1 of the present invention.

[0040] Figure 20 This is the graph showing the inhibitory effects of compounds A and B on benign prostatic hyperplasia cells (BPH-1) detected by the MTT method in Example 2 of the present invention. The positive drug is finasteride. The test concentrations are 12.5, 25, 50, 100, 200, and 400 μM in sequence (Note: compared with the blank group, *P<0.05, ****P<0.0001).

[0041] Figure 21 The enrichment fractionation graph of two lignan compounds obtained by GNPS molecular network analysis in Example 1 of the present invention. Detailed implementation manners

[0042] The present invention will be described in detail below through specific examples, but the protection scope of the present invention is not limited. Unless otherwise specified, the experimental methods adopted in the present invention are all conventional methods, and the experimental equipment, materials, reagents, etc. used can all be obtained from commercial channels.

[0043] Example 1

[0044] Preparation of lignan compounds;

[0045] Weigh 1 kg of dry whole herb of Piper szemaoense, crush it, and then reflux extract it with 95% (v / v) ethanol for 3 - 4 times, each extraction for 3 - 4 h. After filtering off the residue, concentrate it under reduced pressure (water temperature 50°C, vacuum degree 20 mmHg, rotation speed 120 rpm) to obtain 96 g of ethanol extract paste. The ethanol extract paste is fully suspended with hot deionized water, and successively extracted 3 - 5 times repeatedly with petroleum ether, ethyl acetate, and n-butanol saturated with water in equal volume ratios as extraction agents. After the extraction liquid becomes colorless, combine the extraction liquids and concentrate them under reduced pressure (water temperature 50°C, vacuum degree 20 mmHg, rotation speed 120 rpm) to obtain 15.4 g of petroleum ether extract, 11.4 g of ethyl acetate extract, and 34.4 g of n-butanol extract respectively. Take 11.4 g of the ethyl acetate layer extract of Piper szemaoense, use normal-phase column silica gel chromatography (dichloromethane - methanol, 100:0 - 0:100) for gradient elution, detect and track the eluted fractions according to the thin-layer chromatography results, combine the same fractions, and elute them with a gradient of petroleum ether:ethyl acetate (50:1 - 1:5) system (retention volume 5 L). Separate and purify with semi-preparative high-performance liquid chromatography (methanol - water, 35:65, v / v, 3 ml / min, 210 nm) to finally obtain compound A (1.2 mg). Use a gradient elution with a petroleum ether:ethyl acetate (20:1 - 1:2) system, use Sephadex LH20 (dichloromethane - methanol, 1:1, v / v), and semi-preparative high-performance liquid chromatography (acetonitrile - water, 48:52, v / v, 3 ml / min, 210 nm) for separation and purification to finally obtain compound B (1.4 mg).

[0046] Compound A was prepared as a yellowish brown solid (methanol), and its specific rotation was measured to be -10 (c 0.1, MeOH). HRESI-MS gave a quasi-molecular ion peak of 371.1466 [M+Na] + (calcd for C 19 H 24 O 6 Na 371.1471), and combined with 1 H, 13 C NMR data to determine its molecular formula as C 19 H 24 O 6 , and its degree of unsaturation was calculated to be 8, and its general formula is as follows:

[0047]

[0048] For compound A, 1 H NMR (500 MHz, DMSO-d 6 ) spectrum, δ 6.63 (1H, s, H-3), 6.94 (1H, s, H-6), 6.09 (1H, br d, J = 2.5 Hz, H-3'), 6.04 (1H, br d, J = 2.5 Hz, H-5') showed the presence of a 1,2,4,5-tetrasubstituted and a 1,2,4,6-tetrasubstituted benzene ring. δ 10.25 (1H, s, 2'-OH), 8.90 (1H, br s, 4'-OH), 5.86 (1H, br s, 8-OH) showed the presence of 3 active hydrogen signals, δ 3.54 (3H, s, 5-OCH 3 ), 3.75 (3H, s, 4-OCH 3 ), 3.78 (3H, s, 2-OCH 3 ) showed the presence of 3 methoxy signals, δ 1.03 (3H, d, J = 6.0 Hz, H-9), 2.06 (3H, s, H-7') showed the presence of two methyl signals. In addition, two methine hydrogen signals of δ 4.39 (1H, d, J = 5.0 Hz, H-7), 4.43 (1H, m, H-8) were also shown.

[0049] 13 C NMR (125 MHz, DMSO-d 6)The spectrum and HSQC spectrum show the presence of 12 aromatic carbon signals: δ122.2 (C-1), 150.8 (C-2), 98.1 (C-3), 147.8 (C-4), 142.1 (C-5), 115.8 (C-6), 116.5 (C-1'), 156.8 (C-2'), 101.9 (C-3'), 155.9 (C-4'), 109.0 (C-5'), 139.2 (C-6'); 2 sp 3 hybridized tertiary carbons: δ44.4 (C-7), 67.5 (C-8); 2 methyl carbons: δ21.0 (C-7'), 22.0 (C-9), 3 methoxy carbons: δ55.8 (2-OCH 3 ), 56.3 (4-OCH 3 ), 56.5 (5-OCH 3 ).

[0050] In the HMBC spectrum, correlations exist between δ4.39 (1H, d, J = 5.0 Hz, H-7) and δ122.2 (C-1), 150.8 (C-2), 67.5 (C-8), 116.5 (C-1'), 156.8 (C-2'), 139.2 (C-6'), and between δ1.03 (3H, d, J = 6.0 Hz, H-9) and δ44.4 (C-7), 67.5 (C-8), indicating that two fragments of 1,2,4,5-tetrasubstituted benzene ring and 1,2,4,6-tetrasubstituted benzene ring are connected together through C-7. The correlation between δ1.03 (3H, d, J = 6.0 Hz, H-9) and δ44.4 (C-7), 67.5 (C-8) indicates the presence of a propan-2-ol fragment. The correlation between δ2.06 (3H, s, H-7') and δ116.5 (C-1'), 109.0 (C-5'), 139.2 (C-6') indicates that the methyl is connected to C-6'. According to the correlation between δ3.78 (3H, s, 2-OCH 3 ) and δ150.8 (C-2), the correlation between δ3.75 (3H, s, 4-OCH 3 ) and 147.8 (C-4), and the correlation between δ3.54 (3H, s, 5-OCH 3 ), the connection positions of each methoxy group are determined. According to the correlation between δ10.25 (1H, s, 2'-OH) and δ101.9 (C-3'), and the correlation between δ8.90 (1H, br s, 4'-OH) and δ101.9 (C-3'), 155.9 (C-4'), 109.0 (C-5'), the connection positions of each hydroxyl group are determined. According to the coupling constant (J = 5.0 Hz) between the ortho protons of H-7 and H-8 in the hydrogen spectrum, the relative configuration is determined to be 7R * , 8S* In summary, the planar structure of compound A is shown below.

[0051]

[0052] Its absolute configuration was determined by comparing the calculated and measured ECD. The experimental CD curve of compound A was in good agreement with the calculated ECD curve preset for the 7S, 8R configuration ( Figure 2 ). Therefore, the absolute configuration of compound A was determined to be 7S, 8R.

[0053] In summary, the structure of compound A was determined and all its carbon and hydrogen signals were assigned, as shown in Table 1.

[0054] Table 1. 1H NMR (500 MHz) and 13C NMR (125 MHz) data of compound A

[0055]

[0056]

[0057] Compound B was prepared as a yellowish-green solid (methanol), and its specific rotation was measured to be -2.0 (c 0.1, MeOH). HRESI-MS gave the quasi-molecular ion peak 439.1361 [M+Na] + (calcd for C 22 H 24 O 8 Na 439.1369), and combining with 1 H, 13 13C NMR data, its molecular formula was determined to be C 22 H 24 O 8 , and its degree of unsaturation was calculated to be 11. Its general formula is shown below:

[0058]

[0059] In the 1 1H NMR (500 MHz, DMSO-d 6 ) spectrum of compound B, δ 7.39 (1H, d, J = 7.7 Hz, H-4), 7.48 (1H, t, J = 7.7 Hz, H-5), 7.29 (1H, d, J = 7.7 Hz, H-6) indicated the presence of a 1,2,3-trisubstituted benzene ring. δ 6.70 (1H, s, H-3'), 6.73 (1H, s, H-6') indicated the presence of a 1,2,4,5-tetrasubstituted benzene ring. δ 5.36 (1H, s, H-2") suggested the presence of an olefinic proton signal. δ 3.71 (3H, s, 1"-OCH 3), 3.48 (3H, s, 3"-OCH 3 ), 3.51 (3H, s, 7-OCH 3 ), 3.83 (3H, s, 2'-OCH 3 ), 3.63 (3H, s, 4'-OCH 3 ), 3.71 (3H, s, 5'-OCH 3 ) shows the presence of six methoxy groups.

[0060] 13 C NMR (125 MHz, DMSO-d 6 ) spectrum and HSQC spectrum show the presence of 2 carbonyl carbons: δ 167.6 (C-7), 165.9 (C-3"); 12 aromatic carbon signals: δ 134.2 (C-1), 132.1 (C-2), 137.0 (C-3), 132.2 (C-4), 129.0 (C-5), 128.5 (C-6), 119.6 (C-1'), 149.2 (C-2'), 97.8 (C-3'), 150.0 (C-4'), 142.5 (C-5'), 114.7 (C-6'); two alkene carbon signals: δ 170.6 (C-1"), 92.5 (C-2"); 6 methoxy carbon signals: δ 56.9 (1"-OCH 3 ), 50.5 (3"-OCH 3 ), 51.5 (7-OCH 3 ), 55.8 (2'-OCH 3 ), 55.7 (4'-OCH 3 ), 56.2 (5'-OCH 3 ).

[0061] In the HMBC spectrum, δ 7.29 (1H, d, J = 7.7 Hz, H-6) correlates with δ 170.6 (C-1"), δ 5.36 (1H, s, H-2") correlates with δ 170.6 (C-1"), 134.2 (C-1), δ 3.71 (3H, s, 1"-OCH 3 ) correlates with δ 170.6 (C-1"), δ 3.48 (3H, s, 3"-OCH 3 ) correlates with δ 165.9 (C-3"), indicating that the 1,2,3-trisubstituted benzene ring is connected to the methyl 3-(methoxy)but-2-enoate group at the C-1" position. δ 7.39 (1H, d, J = 7.7 Hz, H-4) correlates with δ 119.6 (C-1'), δ 6.73 (1H, s, H-6') correlates with δ 137.0 (C-3), indicating that C-3 of the 1,2,3-trisubstituted benzene ring is connected to C-1' of the 1,2,4,5-tetrasubstituted benzene ring. δ 3.51 (3H, s, 7-OCH3 ) is related to δ167.6 (C-7), demonstrating that the methoxy group is attached to the C-7 position. δ3.71 (3H, s, 5'-OCH 3 ) is related to δ142.5 (C-5'), and δ3.63 (3H, s, 4'-OCH 3 ) is related to δ150.0 (C-4'), and δ3.83 (3H, s, 2'-OCH 3 ) is related to δ149.2 (C-2'), indicating the attachment positions of each methoxy group. In the NOESY spectrum, δ5.36 (1H, s, H-2") is related to δ3.71 (3H, s, 1"-OCH 3 ) is related to δ3.71 (3H, s, 1"-OCH Figure 19 ), thus determining that the configuration between C-1" and C-2" is E-form (

[0062]

[0063] In summary, the structure of compound B is determined and all its carbon and hydrogen signals are assigned, as shown in Table 2.

[0064] Table 2. 1H NMR (500 MHz) and 13C NMR (125 MHz) data of compound B

[0065]

[0066]

[0067] Example 2: Detection of the inhibitory effects of compounds A and B on benign prostatic hyperplasia cells (BPH-1) by MTT assay;

[0068] S1. Cell resuscitation

[0069] The cryopreserved BPH-1 cells (purchased from Zhenjiang Aibimeng Biotechnology Co., Ltd., China) were taken out from the -80 °C refrigerator, quickly placed in a 37 °C water bath to thaw, and then immediately added with twice the amount of RPMI-1640 complete medium (gibco C11875500BT) containing 10% fetal bovine serum. After centrifugation at 800 r / min for 4 min, the supernatant was discarded, 5 ml of 1640 culture medium was added, and the cells were pipetted repeatedly and transferred to a culture flask, and cultured in a constant temperature incubator (37 °C, 5% CO 2 ).

[0070] S2. Cell passage

[0071] The old culture medium in the culture flask was aspirated, 2 ml of PBS was added and the cells were washed twice, then 1.5 ml of trypsin was added, and the flask was placed in a constant temperature incubator (37 °C, 5% CO 2) After digestion for 2 min, quickly take it out, add 2 times (4 ml) of RPMI-1640 complete medium (10% fetal bovine serum, 1% double antibody) to stop cell digestion, then transfer it to a 15 ml centrifuge tube, centrifuge at 800 r / min for 4 min, discard the supernatant, add 5 ml of 1640 culture medium, pipette repeatedly, and then transfer it to a culture flask and continue to culture in a constant temperature incubator (37 °C, 5% CO 2 ) and continue the culture.

[0072] S3. MTT assay to determine the inhibitory effect of compounds on BPH-1

[0073] Take BPH-1 cells in good growth and in logarithmic growth phase from the cell incubator, inoculate the cells into a 96-well plate, control the cell number to be 7×10 3 cells / well, 100 μL of culture medium per well. After cell plating, place it in the incubator and culture for 24 h until the cells are fully adherent. Dissolve compound A, compound B and the positive drug (finasteride) with 0.5% DMSO, add them to the basal 1640 medium to prepare compound concentrations of 400 μM, 200 μM, 100 μM, 50 μM, 25 μM, 12.5 μM, a total of 6 gradients, 6 replicates. After adding the drugs in sequence and continuing to culture for 24 h, add 20 μL of MTT solution (5 mg / mL) to each well under light protection and continue to culture for 4 h. After the reaction ends, aspirate all the liquid, leaving the purple formazan precipitate. Randomly add 150 μL of DMSO, shake on a shaker. After the purple formazan is completely dissolved in DMSO and the color is evenly distributed, measure it at 490 nm with an enzyme-linked immunosorbent assay (Varioskan LUX, Thermo Fisher Scientific Inc.). Calculate the growth inhibition rate (IR) of the cells according to the obtained absorbance (OD), and calculate the half-inhibitory concentration (IC 50 ) using the modified Karber method.

[0074] Statistical analysis

[0075] All results and data were confirmed in at least three independent experiments. All data results obtained were expressed as mean ± standard deviation `c±SD. One-way analysis of variance was performed on the data of each group using GraphPad Prism 6 (California, USA) software. P<0.05 was considered statistically significant.

[0076] As shown in the experimental results, compound A and compound B have the activity of inhibiting benign prostatic hyperplasia cells (BPH), and the IC 50 values are 82.10 μM and 82.40 μM respectively, which are similar to the activity of the positive drug finasteride (IC 50 = 62.96 μM). From the results, the IC 50The values were comparable. The inhibitory effects of the positive drug and the compound on BPH cells both increased in a dose-dependent manner, that is, the higher the compound concentration, the more obvious the inhibitory effect and the better the activity. When the administration concentration reached above 200 μM, the inhibitory effect of the drug on BPH cells could reach above 70%. However, after continuously increasing the administration concentration, the inhibitory effect was not significantly affected. When the administration concentration was at the lowest (12.5 μM), the inhibitory effect of Compound A on the cells was significantly higher than that of the positive drug and Compound B, with an inhibition rate of 6.58 ± 0.018%, while the inhibition rates of the positive drug and Compound B were only 2.63 ± 0.022% and 2.72 ± 0.011% respectively.

[0077] In summary, Compound A and Compound B have good inhibitory effects on BPH cells, and the inhibitory effects on BPH cells increase in a dose-dependent manner. After the administration concentration reaches 200 μM, the inhibitory effect no longer changes significantly. It is worth noting that at a low concentration (12.5 μM), Compound A has a better inhibitory effect on BPH cells than the positive drug. Therefore, both Compound A and Compound B are expected to be developed into drugs for the treatment of benign prostatic hyperplasia. When considering the dosage problem, Compound A can be developed as a better selective drug for the treatment of BPH diseases.

[0078] The above-described embodiments are only the preferred embodiments of the present invention, and not all the feasible embodiments of the present invention. For those of ordinary skill in the art, any obvious changes made without departing from the principle and spirit of the present invention should be considered to be included within the protection scope of the claims of the present invention.

Claims

1. A lignan compound, characterized in that The liposome compound is a compound A having a structure shown in Formula 1 or a compound B having a structure shown in Formula 2; 2. The lignan compound according to claim 1, characterized in that: Lignans were isolated from Piper melongena.

3. The method for preparing the lignan compounds according to claim 1, characterized in that: The dried whole herb of Piper melongena was used as raw material. After crushing, it was extracted with 95% ethanol reflux for 3 to 4 times, each time for 3 to 4 hours. The extracted part was separated and purified by silica gel column chromatography, medium pressure column chromatography, preparative and semi-preparative high performance liquid chromatography. The GNPS molecular network strategy was used to guide the separation of the ethanol extract of Piper melongena plants, and lignan compounds A and lignan compounds B were discovered and obtained.

4. The method for preparing the lignan compounds according to claim 3, characterized in that: The conditions for separation and purification of compound A by preparative and semi-preparative HPLC were as follows: octadecylsilane bonded silica gel was used as the stationary phase, the mobile phase was a 35:65 methanol-water mixed solvent, the flow rate was 3 mL / min, and the detection wavelength of the UV detector was 210 nm.

5. The method for preparing the lignan compounds according to claim 3, characterized in that: The conditions for separation and purification of compound B by preparative and semi-preparative HPLC were as follows: octadecylsilane bonded silica gel was used as the stationary phase, the mobile phase was a 48:52 acetonitrile-water mixed solvent, the flow rate was 3 mL / min, and the detection wavelength of the UV detector was 210 nm.

6. The method for preparing the lignan compounds according to claim 3, characterized in that: The specific steps are as follows: S1. Weigh the dried whole herb of Peppermint sinensis, crush it, and use 95% ethanol to extract it 3 to 4 times, each time for 3 to 4 hours, with a solid-liquid ratio of 1:3; filter out the residue and concentrate under reduced pressure to obtain an alcohol extract; S2. The alcohol extract is fully suspended with hot deionized water, and petroleum ether, ethyl acetate, and water-saturated n-butanol are used as extractants in equal volume ratios, and the extraction is repeated 3 to 5 times in sequence until the extract is colorless, and the extracts are combined and concentrated under reduced pressure to obtain an ethyl acetate extract; S3. The ethyl acetate layer extract was gradient eluted with a dichloromethane-methanol mixed solvent with a volume ratio of 100:0-0:100, and the eluted fractions were detected and tracked according to the thin layer chromatography results. The same fractions were merged, and the secondary mass spectrometry data of the samples were collected by LC-MS / MS method for the fractions. The original data files were converted into data files in mzXML, mzML and mgf formats and imported into the GNPS database to establish a molecular network. The molecular network diagram was analyzed with the help of the GNPS data platform to obtain known compounds. Then, according to the correlation between nodes in the molecular network diagram, the similarities and differences of mass spectrometry data between related nodes were compared to find the fractions enriched with new compounds, and fractions 4 and 5 were found; S4. Fraction 4 was gradient eluted with a petroleum ether-ethyl acetate mixed solvent in a volume ratio of 50:1-1:5, octadecylsilane bonded silica gel was used as the stationary phase, the mobile phase was a methanol-water mixed solvent of 35:65, the flow rate was 3 mL / min, and the detection wavelength of the ultraviolet detector was 210 nm for further separation and purification, and finally compound A shown in formula 1 was obtained; S5. Fraction 5 was gradient eluted with a petroleum ether-ethyl acetate mixed solvent in a volume ratio of 20:1-1:2, and separated again using Sephadex LH20, eluted with a dichloromethane-methanol mixed solvent in a volume ratio of 1:1, octadecylsilane bonded silica gel as the stationary phase, and a 48:52 acetonitrile-water mixed solvent as the mobile phase. The flow rate was 3 mL / min, and the detection wavelength of the ultraviolet detector was 210 nm for further separation and purification, and finally compound B shown in formula 2 was obtained.

7. Use of the lignan compounds prepared by the method for preparing lignan compounds according to any one of claims 2 to 6 in preparing drugs against benign prostatic hyperplasia.

Images