Tetrahydrofuran lignan compound as well as preparation method and application thereof

Abstract

The invention discloses a tetrahydrofuran lignan compound as well as a preparation method and application thereof, the tetrahydrofuran lignan compound is a compound shown as a formula (I) or pharmaceutically acceptable salt thereof, the compound is a natural compound extracted from rubus corchorifolius stems, has anti-inflammatory activity and anti-tumor activity, and can be used for preparing a medicine for treating tumors. The compound has the potential of being developed into anti-inflammatory or anti-tumor drugs and can be used as a lead compound.

Description

Technical Field

[0001] This invention belongs to the field of natural product chemistry, specifically relating to a tetrahydrofuran lignan compound, its preparation method, and its uses. Background Technology

[0002] In Tibetan medicine, the suspensa wood ( R. sachalinensis Leveille is a member of the Rosaceae family ( Rosaceae Rubus genus ( Rubus The plant (L.) with the Tibetan name Ganzagari has a sweet, bitter, astringent, and slightly pungent taste. After digestion, it tastes sweet and sour. It is warm in nature and has mild effects. It has the effects of clearing heat and detoxifying, and promoting the formation of epidemic fever, especially effective for various lung diseases. It is the principal medicine in Tibetan medicine for treating Lung fever, Pegen-type Mubu disease, and promoting the formation of epidemic fever in the early stages of epidemic diseases. Plants in this genus have rich chemical structures. Previous studies have found that this plant contains a large number of lignans, as well as triterpenoids, flavonoids, and other compounds. Research has shown that lignans have various biological activities, including anti-tumor, antioxidant, hepatoprotective, anti-inflammatory, immunomodulatory, and neuroprotective effects.

[0003] Therefore, the extraction, isolation, and discovery of new compounds with medicinal value from Rubus kusnezoffii, a plant used in Tibetan medicine, is of great significance for the comprehensive development and utilization of Rubus kusnezoffii medicinal materials. At the same time, it also provides candidate drugs for drug development and offers new hope for treatment to patients. Summary of the Invention

[0004] The present invention aims to provide a tetrahydrofuran lignan compound, its preparation method, and its uses. This compound exhibits antitumor activity and strong anti-inflammatory activity.

[0005] In some embodiments, the present invention provides a tetrahydrofuran lignan compound, said compound being a compound of formula (I) or a pharmaceutically acceptable salt thereof.

[0006] (I).

[0007] In some embodiments, the present invention provides a method for preparing the compound of formula (I) of claim 1, comprising the following steps: S1. Weigh the peeled and pith-free Rugosa stems, coarsely crush them, and extract them by reflux with 70% ethanol. Concentrate the extract under reduced pressure to obtain an ethanol extract. S2. Dissolve the ethanol extract in methanol, add petroleum ether for extraction, and concentrate the lower methanol layer under reduced pressure to obtain the methanol extract. S3. Dissolve the methanol extract in a mixed solvent of water and methanol, add dichloromethane for extraction, and concentrate the dichloromethane portion under reduced pressure to obtain the dichloromethane extract. S4. The dichloromethane extract was subjected to normal-phase silica gel column chromatography with gradient elution to obtain five components: A, B, C, D, and E. S5. Pass component C through normal-phase silica gel column chromatography with gradient elution to obtain 7 components: Ca, Cb, Cc, Cd, Ce, Cf, and Cg. S6. The Cf fraction was subjected to medium-pressure ODS reverse-phase column chromatography with gradient elution to obtain 14 fractions, labeled as Cf-01 to Cf-14; S7. After separating the Cf-05 component by semi-preparative high performance liquid chromatography, compound (I) is obtained.

[0008] In some embodiments, the gradient elution conditions for the normal-phase silica gel column chromatography in step S4 of the preparation method of the present invention are as follows: using dichloromethane:methanol as the eluent, and performing gradient elution at volume ratios of 80:1, 60:1, 30:1, 10:1, 8:2, 7:3, 6:4, 1:1, 3:7, and 0:1. In some embodiments, the normal-phase silica gel column chromatography in step S5 of the preparation method of the present invention is carried out under the following gradient elution conditions: using petroleum ether:methanol as the eluent, and performing gradient elution at a volume ratio of 10:1, 7:1, 8:2, 7:3, 6:4, 1:1, 4:6, 2:8, and 0:1. In some embodiments, the medium-pressure ODS reversed-phase column chromatography in step S6 of the preparation method of the present invention is performed under the following gradient elution conditions: using methanol:water as the eluent, and performing gradient elution at a volume ratio of 10:90, 30:70, 40:60, 50:50, 70:30, 80:20, 90:10, and 100:0. In some embodiments, the high-performance liquid chromatography (HPLC) separation in step S7 of the preparation method of the present invention is performed under the following chromatographic conditions: detection wavelength of 210-302 nm, using a mixed solvent of methanol and water as the eluent, isocratic elution at a methanol:water volume ratio of 37:63, and a flow rate of 3 mL / min; then, gradient elution is performed at a detection wavelength of 210-302 nm, using a mixed solvent of acetonitrile and water as the eluent, with an acetonitrile volume ratio ranging from 15% to 35%, for 80 min, and a flow rate of 3 mL / min.

[0009] To more effectively separate the compounds, the components eluted by column chromatography in steps S4-S6 of the preparation method can be further detected and combined by TLC to form several components, wherein the developing solvent is a mixture of dichloromethane and methanol with a volume ratio of 10:1. In other embodiments, the present invention also provides the use of tetrahydrofuran lignan compounds of formula (I) in the preparation of anti-inflammatory drugs.

[0010] In other embodiments, the present invention also provides the use of tetrahydrofuran lignan compounds of formula (I) in the preparation of antitumor drugs.

[0011]

[0012] Equation (Ⅰ).

[0013] Technical effects: The compound of formula (I) of this invention is a natural compound extracted and isolated from Rubus cusia, a plant used in Tibetan medicine, which is quite rare. Furthermore, this compound was found to be chiral, possessing strong anti-inflammatory activity and effects. In addition, this compound also exhibits certain anti-tumor activity, making it a potential candidate drug or lead compound for innovative drugs, with the potential to be developed into anti-inflammatory or anti-tumor drugs, providing patients with more treatment options.

[0014] The advantages and beneficial effects of the technical solution provided by this invention are as follows: This invention obtains a new compound (I) of the 7-O-9′ type tetrahydrofuran lignan by separating and purifying the ethanol extract of Rubus cuspidata stem. Using a combination of spectroscopic analysis methods, it is confirmed to be a tetrahydrofuran lignan compound. In vitro anti-inflammatory activity experiments on the obtained compound revealed a significant inhibitory effect on the inflammatory factor NO. This invention provides a lead compound for the development of new anti-inflammatory drugs and is of great significance for the comprehensive development and utilization of Rubus cuspidata medicinal materials. Attached Figure Description

[0015] Figure 1 The flowchart shows the extraction and separation process of tetrahydrofuran lignans prepared in Example 1. Figure 2 The compound obtained in Example 1 1 H-NMR (500MHz, CD3OD) spectrum; Figure 3 The compound obtained in Example 1 13 C-NMR (125MHz, CD3OD) spectrum; Figure 4 DEPT (Distortionless Enhancement) of the compound prepared in Example 1 Spectrum obtained by PolarizationTransfer (distortion-free polarization transfer technique) (θ = 90°); Figure 5 The DEPT (θ = 135°) spectrum of the compound obtained in Example 1; Figure 6 The HSQC of the compound prepared in Example 1 1H-detected Heteronuclear Single Quantum Coherence (H-detected Heteronuclear Single Quantum Coherence Spectrum); Figure 7 HMBC (the compound prepared in Example 1) 1 H-detected Heteronuclear Multiple Bond Correlation (H-detected Heteronuclear Multiple Bond Correlation Spectrum); Figure 8 The compound obtained in Example 1 1 H- 1 HCOSY (Correlation Spectroscopy) spectrum; Figure 9 The ROESY (Rotated NOE) spectrum of the compound obtained in Example 1; Figure 10 The UV spectrum of the compound obtained in Example 1; Figure 11 The HR-ESI-MS spectrum of the compound obtained in Example 1; Figure 12 The CD spectrum of the compound obtained in Example 1; Figure 13 ECD and CD spectra of the compound prepared in Example 1 were calculated; Figure 14 The effect of the compound in Example 1 on the viability (toxicity) of RAW264.7 cells; Figure 15 The effect of the compound in Example 1 on NO release is shown in the figure. CON: control group; LPS: model group. Statistical data are expressed as mean ± SEM. ###p<0.001, where # indicates control group vs. model group; ***p<0.001, **p<0.01, *p<0.05, where * indicates model group vs. drug-treated group. Figure 16 The effect of compound A in Example 1 and known compound B on NO release. Detailed Implementation

[0016] The following embodiments are provided to describe the present invention in more detail. However, these embodiments are provided only to help further understand the present invention and are not intended to limit the present invention. Those skilled in the art should understand that equivalent substitutions or corresponding improvements made to the content of the present invention still fall within the protection scope of the present invention.

[0017] Unless otherwise specified, the experimental methods used in the following examples are conventional methods. Unless otherwise specified, all materials and reagents used in the following examples are commercially available. Example 1 Extraction and separation of compound (I) This embodiment provides a preparation process for extracting and isolating a 7-O-9′ type tetrahydrofuran lignan compound from the stem of *Rubus saxifragana*. The *Rubus saxifragana* stem was collected in July 2022 in Huangzhong District, Xining City, Qinghai Province, and identified by the Northwest Plateau Institute of Biology, Chinese Academy of Sciences as *Rubus saxifragana*, a plant belonging to the genus *Rubus* of the family Rosaceae. Rubus Sachalinensis The specimen (Leveile) is deposited at the School of Pharmacy, South-Central University for Nationalities, with specimen number 20220701.

[0018] The specific extraction and separation steps are as follows: Step S1: Weigh 20 kg of dried, peeled and pith-free Rubus cusia stems, coarsely crush them, and extract them three times by reflux with 70% (v / v) ethanol for 2 hours each time. After each extraction, filter the extracts and collect them. Combine the extracts from the three filtrations, concentrate them under reduced pressure, and obtain the total extract (1.94 kg). Step S2: Dissolve the total extract obtained in the previous step with methanol, then add petroleum ether for extraction. Concentrate the upper petroleum ether portion under reduced pressure to obtain the petroleum ether extract (58.9g). Concentrate the lower methanol portion under reduced pressure to obtain the methanol extract. Step S3: Dissolve the methanol extract obtained in the previous step again with a 9:1 (v / v) mixture of water and methanol, then add dichloromethane for extraction, concentrate the dichloromethane portion under reduced pressure to obtain a dichloromethane extract (72.2g).

[0019] Step S4: Normal-phase silica gel column chromatography was performed on the dichloromethane extract using dichloromethane and methanol as mobile phases for gradient elution (gradient program: dichloromethane:methanol = 80:1, 60:1, 30:1, 10:1, 8:2, 7:3, 6:4, 1:1, 3:7, 0:1, v / v). Similar components were identified and combined using TLC (developing solvent: dichloromethane:methanol = 20:1, v / v; the amount of methanol increased with increasing compound polarity). Five components were obtained and labeled A, B, C, D, and E in ascending order of polarity. The eluents with dichloromethane:methanol volume ratios of 30:1 and 10:1 were collected and labeled C. The eluents were concentrated to dryness under reduced pressure and set aside for later use.

[0020] Step S5: Dry loading of fraction C (6.6 g) was performed using normal-phase silica gel column chromatography with gradient elution using petroleum ether and methanol as the mobile phase (program: petroleum ether:methanol = 10:1, 7:1, 8:2, 7:3, 6:4, 1:1, 4:6, 2:8, 0:1, v / v). The eluent was analyzed by TLC (developing solvent: dichloromethane:methanol = 10:1, v / v; the amount of methanol increased with increasing compound polarity) to combine similar components, resulting in 7 fractions, which were labeled as Ca, Cb, Cc, Cd, Ce, Cf, and Cg in ascending order of polarity. The eluents with petroleum ether:methanol volume ratios of 8:2, 7:3, and 6:4 were collected and labeled as Cf. The eluents were concentrated to dryness under reduced pressure for later use.

[0021] Step S6: Dry loading of component Cf (2.9 g) was performed using medium-pressure ODS reversed-phase column chromatography with gradient elution of methanol and water (methanol:water = 1:9, 3:7, 4:6, 1:1, 7:3, 8:2, 9:1, 1:0, v / v). The eluent was analyzed by TLC (developing solvent was dichloromethane:methanol = 10:1, v / v; the amount increased with increasing compound polarity). Similar components were combined to obtain 14 components, which were labeled Cf-01 to Cf-14 in descending order of polarity. The eluent with a methanol:water volume ratio of 4:6 was collected and labeled Cf-05. The eluent was concentrated to dryness under reduced pressure for later use.

[0022] Step S7: The fraction Cf-05 (130 mg) obtained in the previous step was separated and purified by high performance liquid chromatography (HPLC) using a semi-preparative YMC-Pack ODS-A column (250 × 10 mm, 5 μm). The detection wavelength was 210 nm or 302 nm. A mixture of methanol and water was used as the eluent, and isocratic elution was performed at a methanol:water volume ratio of 37:63 at a flow rate of 3 mL / min. Then, gradient elution was performed at detection wavelengths of 210 nm and 302 nm using acetonitrile:water, with a volume ratio of acetonitrile ranging from 15% to 35%, for 80 min at a flow rate of 3 mL / min. The retention time t was recorded. R The substance with a weight of 52.6 min is the 7-O-9′ type tetrahydrofuran lignan compound shown in formula (I) of this invention, with a weight of 18.38 mg. The flowchart of the above steps can be found here. Figure 1 . The product obtained in Example 1 was analyzed by high-resolution mass spectrometry, ultraviolet spectroscopy, optical rotation, nuclear magnetic resonance, and ECD calculations to confirm the structure of the compound. The physicochemical and spectroscopic data are as follows: Yellow oily substance, HR-ESI-MS m / z: 441.15198 [M+Na] + (calcd for C 22 H 26O8Na,619.39986); (c 0.05, MeOH), UV (MeOH) λmax (logε): 235 (3.32)nm, 270 (3.04)nm; ECD (1.14×10 -4 M, MeOH) λ(θ) 255 (+3.83), 234 (+3.99), 2.04 (+4.11), 194 (+4.66) nm; The NMR data of the compound are shown in Table (2). 1 The H NMR (500MHz, CD3OD) spectrum is shown below. Figure 2 , 13 The C-NMR (125MHz, CD3OD) spectrum is shown below. Figure 3 The DEPT (θ=90°) spectrum is shown below. Figure 4 The DEPT (θ = 135°) spectrum is shown below. Figure 5 HSQC spectrum can be found Figure 6 HMBC spectrum can be found Figure 7 , 1 H- 1 See the H COSY spectrum. Figure 8 See ROESY spectrum Figure 9 See UV spectrum Figure 10 HR-ESI-MS spectra can be found Figure 11 See CD spectrum Figure 12 Based on the high-resolution mass spectrometry and various NMR data, the planar structure of the compound can be identified as 5,4′,8′-trihydroxy-3,3′-dimethoxy-9-acetoxyl-7,9′-epoxylignane. To further determine the final structure of this compound, NMR calculations were performed at the mPW1PW91 / 6-311G (2d, p) level for both ortho and meta substitutions. The methanol solvent model used was IEFCM. The final NMR calculation results and DP4+ analysis favored ortho substitution. Furthermore, to determine the absolute configuration of the compound, time-dependent density functional theory (TD-DFT) was employed at the B3LYP / 6-311G (d, p) theoretical level to analyze the possible enantiomers (7... R 8 S ,8' S ) and (7 S 8 R ,8' R For ECD calculation, see [link / reference]. Figure 13 The results showed that 7 R 8 S ,8' SThe configuration curve matches the experimental ECD curve, therefore the absolute configuration of the compound is determined to be 7. R 8 S ,8' S。

[0023] Table 1: Chinese and English nomenclature of compounds

[0024] Table 2: Compounds 1 H-NMR and 13 C-NMR data

[0025] (Record in CD3OD) Example 2: In vitro anti-inflammatory activity test In vitro anti-inflammatory activity experiments were conducted on compound (I) obtained in Example 1: The compound (I) (7R,8S,8′S)-4,4′,8′-trihydroxy-3,3′-dimethoxy-9-acetoxy-7,9′-epoxylignan obtained in Example 1 is referred to as "Compound A" in this experiment. An in vitro anti-inflammatory activity comparison experiment was conducted on a known compound (-)-olivil, referred to as Compound B: (-)-olivil in this experiment.

[0026] Materials and reagents: DMEM high glucose medium was purchased from Hyclone Pharmaceuticals, USA; penicillin-streptomycin solution was purchased from Hyclone Pharmaceuticals, USA; fetal bovine serum was purchased from Hangzhou Sijiqing Bioengineering Materials Co., Ltd.; CCK-8 kit was purchased from Shanghai Beyotime Biotechnology Co., Ltd.; dimethyl sulfoxide (DMSO, BIOSHARP, USA); nitric oxide assay kit was purchased from Shanghai Beyotime Biotechnology Co., Ltd.; lipopolysaccharide (LPS) and dexamethasone were purchased from Sigma-Aldrich, USA.

[0027]

[0028] (-)-olivil The tested tumor cell line was RAW264.7 macrophages, purchased from Wuhan Pronosei Biotechnology Co., Ltd. (CatNO: CL-0190).

[0029] (I) CCK-8 assay for cell viability Experimental methods: RAW264.7 cells were cultured in DMEM high-glucose medium (containing penicillin and streptomycin antibiotics) with 10% fetal bovine serum until approximately 80% confluence, then passaged. RAW264.7 cells (1×10⁻⁶) were then...4 Cells were seeded per well into 96-well plates to a final volume of 100 μL and cultured at 37°C for 12 h. Compound A from Example 1 and known compound B were prepared with DMSO at a stock solution concentration of 10 mM, then diluted with DMEM medium to different concentrations (50, 100 μM) and added to the 96-well plates to a final volume of 200 μL. A blank group (no cells, only DMEM medium) and a control group (DMEM medium, containing cells) were also included in the experiment. After incubation for 24 h, 10 μL of CCK-8 solution was added, and the cells were incubated in the dark for another 1 h. The OD value of each well was then measured at 450 nm. Cell viability was calculated (see [link to cell culture]). Figure 14 The cell survival rate is calculated using the formula: (OD experimental group - OD blank group) / (OD control group - OD blank group) × 100%.

[0030] Experimental conclusion: from Figure 14 The cytotoxicity screening results showed that compounds A and B had no significant cytotoxic effects on cells at concentrations of 50 μM and 100 μM, and that compound B was more cytotoxic than compound A at the same concentration.

[0031] (II) NO Activity Assay Experimental methods: RAW264.7 cells were cultured in DMEM high-glucose medium (containing penicillin and streptomycin antibiotics) with 10% fetal bovine serum until approximately 80% confluence, then passaged. Then, 1×10⁻⁶ cells were cultured... 4 RAW264.7 cells per well were seeded into 96-well plates and cultured for 6 hours in a 5% CO2, 37°C cell culture incubator. Different concentrations (5, 10, 20, 40 μM) of compound A from Example 1 and 1 μg / mL lipopolysaccharide (LPS) were prepared in DMEM medium. The old medium in each well was discarded. For the blank group, only DMEM medium (cell-free) was added; for the control group, DMEM medium (with cells) was added; for the model group, 1 μg / mL LPS was added; and for the drug-treated groups, 1 μg / mL LPS and different concentrations of the compound from Example 1 were added. Each well was incubated for 12 hours. Then, 50 μL of the supernatant was collected, and the NO content in the supernatant was determined using the Griess method to calculate the IC50. 50 Values, experimental results are shown in Figure 15 Furthermore, following the above method, 10 μM of compound A from Example 1 and known compound B, along with 1 μg / mL of lipopolysaccharide (LPS), were prepared using DMEM medium. A NO activity comparison experiment was conducted between compound A and known compound B. The experimental results are shown below. Figure 16 .

[0032] Experimental conclusion: Using a CCK-8 assay, the concentrations of compound A with anti-inflammatory activity were set at 5, 10, 20, and 40 μM. Compared with the control group, the release of NO in the model group was significantly increased after stimulation of inflammatory cells with LPS. Simultaneously, compared with the model group, the release of NO decreased with increasing concentration of compound A, indicating that compound A of the present invention has an inhibitory effect on NO. The IC50 was calculated. 50 The value was 9.2 μM. Furthermore, at a concentration of 10 μM, compound A exhibited significantly stronger inhibitory effects on NO than the known compound B.

[0033] Example 3: In vitro antiproliferative activity test In vitro antiproliferative activity experiments were conducted on compound (I) prepared in Example 1. Materials and reagents: DMEM high glucose medium was purchased from Hyclone Pharmaceuticals, USA; penicillin-streptomycin solution was purchased from Hyclone Pharmaceuticals, USA; trypsin was purchased from Hyclone Pharmaceuticals, USA; fetal bovine serum was purchased from Hangzhou Sijiqing Bioengineering Materials Co., Ltd.; CCK-8 kit was purchased from Shanghai Beyotime Biotechnology Co., Ltd.; dimethyl sulfoxide (DMSO, BIOSHARP, USA); Multiskan GO multi-functional microplate reader (Thermo Fisher Scientific, USA).

[0034] The tested tumor cell line was human non-small cell lung cancer cell line A549, purchased from Nanjing Senbeijia Biotechnology Co., Ltd. (Cat NO: BC-C-HU-009).

[0035] (I) Detection of the antiproliferative activity of compound (I) against A549 cells by CCK-8 assay Experimental methods: Experimental grouping and dosage settings: Compound (I) (50 μM) was used as the experimental group, and a control group (equal volume of serum-free culture medium containing cells but not the compound) and a blank control group (equal volume of serum-free culture medium containing neither the compound nor cells) were set up.

[0036] A549 cells in the logarithmic growth phase were cultured in DMEM high-glucose medium (containing penicillin and streptomycin antibiotics) with 10% fetal bovine serum until approximately 80% confluence, then passaged. A549 cells (1×10⁻⁶) were then... 5Cells were seeded per well into 96-well plates to a final volume of 100 μL and cultured at 37°C for 6 h until cell adhesion. Compound (I) from Example 1 was prepared with DMSO at a stock concentration of 10 mM, and then diluted with DMEM to different concentrations. After cell adhesion, the culture medium in the 96-well plates was discarded. After washing with PBS (1×, pH 7.6, the same below), 100 μL of the test compound at a concentration of 50 μmol / L was added to each well, and the plates were incubated at 37°C and 5% CO2 for 48 h. Then, the supernatant from each well was aspirated, and 100 μL of a solution containing 10% (v / v) CCK was added to each well. The culture medium containing the working solution was incubated at 37℃ in 5% CO2 for 1 hour, and the absorbance (A) of each well at 450 nm was measured using a microplate reader. Six replicates were set up for each group. The inhibition rate was calculated based on the measured A values. Gradient concentrations (1, 3.125, 6.25, 12.5, 25, 50 μM) of compound (I) were measured, and the corresponding IC50 values ​​were calculated. 50 value.

[0037] Inhibition rate = [(Control A - Experiment A) / (Control A - Blank A)] × 100%.

[0038] Experimental conclusion: Screening results for antiproliferative activity showed that compound (I) at a concentration of 50 μM had significant antiproliferative effects on A549 cells. The cell inhibition rate of compound (I) in A549 cells was 71.91 ± 1.36%, and the IC50 was calculated. 50 Value 18.22±4.08 μM.

Claims

1. A tetrahydrofuran lignan compound, characterized in that, The compound is a compound of formula (I) or a pharmaceutically acceptable salt thereof. （I）。 2. A method for preparing the compound of formula (I) according to claim 1, characterized in that, Includes the following steps: S1. Weigh the peeled and pith-free rhizomes of Rubus saxaul, coarsely crush them, and extract them by reflux with 70% ethanol. Concentrate the extract under reduced pressure to obtain an ethanol extract. S2. Dissolve the ethanol extract in methanol, add petroleum ether for extraction, and concentrate the lower methanol layer under reduced pressure to obtain the methanol extract. S3. Dissolve the methanol extract in a mixed solvent of water and methanol, add dichloromethane for extraction, and concentrate the dichloromethane portion under reduced pressure to obtain the dichloromethane extract. S4. The dichloromethane extract was subjected to normal-phase silica gel column chromatography with gradient elution to obtain five components: A, B, C, D, and E. S5. Pass component C through normal-phase silica gel column chromatography with gradient elution to obtain seven components: Ca, Cb, Cc, Cd, Ce, Cf, and Cg. S6. The Cf fraction was subjected to medium-pressure ODS reversed-phase column chromatography with gradient elution to obtain 14 fractions, labeled as Cf-01 to Cf-14. S7. After separating the Cf-05 component by semi-preparative high performance liquid chromatography, compound (I) is obtained.

3. The preparation method according to claim 2, characterized in that, In step S4, the gradient elution is performed under the following conditions: using dichloromethane and methanol as eluents, and performing gradient elution at volume ratios of 80:1, 60:1, 30:1, 10:1, 8:2, 7:3, 6:4, 1:1, 3:7, and 0:

1.

4. The preparation method according to claim 2, characterized in that, In step S5, the gradient elution is performed under the following conditions: using petroleum ether:methanol as the eluent, and performing gradient elution at a volume ratio of 10:1, 7:1, 8:2, 7:3, 6:4, 1:1, 4:6, 2:8, and 0:

1.

5. The preparation method according to claim 2, characterized in that, In step S6, the gradient elution is performed using methanol:water as the eluent at volume ratios of 10:90, 30:70, 40:60, 50:50, 70:30, 80:20, 90:10, and 100:

0.

6. The preparation method according to claim 2, characterized in that, In step S7, the high-performance liquid chromatography (HPLC) separation is performed under the following chromatographic conditions: a detection wavelength of 210-302 nm, using a mixed solvent of methanol and water as the eluent, and isocratic elution at a methanol:water volume ratio of 37:63, with a flow rate of 3 mL / min; then, gradient elution is performed at a detection wavelength of 210-302 nm, using a mixed solvent of acetonitrile and water as the eluent, with an acetonitrile volume ratio ranging from 15% to 35%, for 80 min, at a flow rate of 3 mL / min.

7. The preparation method according to any one of claims 3-5, characterized in that, Further, it includes TLC detection of similar components of the eluted components, wherein the developing solvent is a mixture of dichloromethane and methanol in a volume ratio of 10:

1.

8. The use of the tetrahydrofuran lignan compound of claim 1 in the preparation of anti-inflammatory drugs.

9. The use of the tetrahydrofuran lignan compound of claim 1 in the preparation of antitumor drugs.

Images