Biphenyl compounds in dracocephalum oldhami, preparation method and application as anti-inflammatory drugs

Abstract

The present application relates to the technical field of separation and purification of Schizonepeta tenuifolia Briq, and relates to a biphenyl compound in Schizonepeta tenuifolia Briq, a preparation method thereof and application of the biphenyl compound as an anti-inflammatory drug. The biphenyl compound in Schizonepeta tenuifolia Briq is obtained by the following steps: soaking Schizonepeta tenuifolia Briq, heating and reflux extraction, recovering and concentrating under reduced pressure, obtaining total extract of Schizonepeta tenuifolia Briq, extracting and concentrating with petroleum ether, dichloromethane and ethyl acetate, obtaining a dichloromethane part extract, gradient elution separation of the dichloromethane part extract, gradient elution separation of the fourth fraction of the obtained eight fractions, gradient elution separation of the third fraction of the obtained six fractions, gradient elution separation of the fifth fraction of the obtained eight fractions, purification and separation of the eluate, and collection of the eluate, and the biphenyl compound in Schizonepeta tenuifolia Briq is obtained at 16.4 minutes. The present application discloses the biphenyl compound in Schizonepeta tenuifolia Briq for the first time, and in vitro anti-inflammatory pharmacodynamic experiments are carried out, which prove that the biphenyl compound has a certain inhibitory effect on RAW264.7 cells and can be applied to preparation of anti-inflammatory drugs.

Description

Technical Field

[0001] This invention relates to the field of separation and purification technology of Nepeta macrocarpa, specifically to biphenyl compounds from Nepeta macrocarpa, their preparation methods, and their application as anti-inflammatory drugs. Background Technology

[0002] Nepetabracteata Benth is a plant belonging to the genus Nepetta in the family Lamiaceae. It grows on hillsides, valleys, forest edges, and roadsides. The genus Nepetta contains approximately 250 species, mainly distributed in the Mediterranean, Central Asia, and Africa, extending from North Africa to tropical mountainous regions. my country has 38 species, primarily distributed in the mountainous areas of Yunnan, Sichuan, Tibet Autonomous Region, and Xinjiang Uygur Autonomous Region.

[0003] *Nepeta macrocarpa* has high medicinal value. Modern pharmacological studies have shown that its components possess anti-inflammatory, analgesic, antitussive, antiasthmatic, heat-clearing, and dampness-removing effects, and are used to treat bronchitis, cough, asthma, colds, and fever. Inflammation is a basic pathophysiological process, primarily a defensive response, that occurs in living tissues with a vascular system in response to various damaging factors. It is a dynamic process of damage, anti-damage, and repair. Inflammation is an important defense response of the body; moderate inflammation is beneficial to health, but under certain circumstances, it poses a potential threat. For example, viral myocarditis can affect cardiac function, purulent exudate from bacterial meningitis can cause increased intracranial pressure, and tuberculous pericarditis can lead to pericardial thickening. Studies have shown that phenylpropanoids, flavonoids, and alkaloids in *Nepeta macrocarpa* have excellent anti-inflammatory activity.

[0004] Patent document CN114890870A discloses a rosinane diterpenoid in Nepeta cataria extract, its preparation method, and its application. It is the first to disclose NepetabrateH, which exhibits a significant protective effect against acetaminophen (APAP)-induced damage to human liver cancer cells (HepG-2), thus enabling NepetabrateH to be used in the preparation of drugs for preventing and treating liver damage.

[0005] Patent document CN113831245B discloses a diterpenoid in an extract of *Nepeta macrocarpa*, its preparation method, and its application. This invention discloses for the first time compound 1,2,3,4,4a,9,10,10a-octahydro-4a-(hydroxymethyl)-7-isopropyl-1,1-dimethylphenanthren-4-ylacetate (nepetabrate A), and conducted in vitro anti-inflammatory and antibacterial pharmacodynamic experiments on this compound. The experiments clearly showed that this compound has a strong inhibitory effect on RAW264.7 cells, *Staphylococcus aureus*, and *Escherichia coli*, thus enabling its application in the preparation of anti-inflammatory and antibacterial drugs or / and anti-inflammatory and antibacterial health products.

[0006] The above studies indicate that diterpenoids in *Nepeta macrocarpa* possess excellent anti-inflammatory activity, while direct research on biphenyl compounds is limited, with no clear reports available, and their content and activity remain unclear, requiring further verification. Therefore, researching and exploring the chemical composition and activity of biphenyl compounds in *Nepeta macrocarpa* is of great significance. Summary of the Invention

[0007] This invention provides a biphenyl compound from Nepeta macrocephala, its preparation method, and its application as an anti-inflammatory drug, overcoming the shortcomings of the prior art. It discloses for the first time the biphenyl compound contained in Nepeta macrocephala and conducts in vitro anti-inflammatory pharmacodynamic experiments, proving that it can be used in the preparation of anti-inflammatory drugs.

[0008] One of the technical solutions of this invention is achieved through the following measures: a biphenyl compound from Nepeta macrocarpa, with the following chemical structural formula: .

[0009] The following are further optimizations and / or improvements to one of the above-mentioned inventive technical solutions: The biphenyl compounds in the above-mentioned Nepeta macrocarpa were obtained by the following method: The first step is to pulverize the large-bracted catnip, soak it in ethanol solution, heat and reflux to extract it, combine the reflux extracts, and recover and concentrate them under reduced pressure to obtain the total extract of large-bracted catnip. The second step involves dispersing the total extract of Nepeta macrocarpa in water into a suspension, and then extracting it sequentially with petroleum ether, dichloromethane, and ethyl acetate. After concentrating the extract, petroleum ether fraction extract, dichloromethane fraction extract, and ethyl acetate fraction extract are obtained. The third step involved separating the dichloromethane fraction using silica gel column chromatography with gradient elution to obtain eight fractions. The fourth step involves separating the fourth of the eight fractions by gradient elution using silica gel column chromatography to obtain six fractions. Fifth step: Separate the third fraction of the obtained 6 fractions by gradient elution using silica gel column chromatography to obtain 8 fractions; Step 6: The fifth fraction of the eight fractions obtained was purified and separated by semi-preparative liquid chromatography gradient elution, and the eluent was collected. At 16.4 minutes, biphenyl compounds from Nepeta macrocarpa were obtained.

[0010] In the first step above, each 50 kg of Nepeta macrocarpa is extracted with a 90% to 95% ethanol solution by heating to a temperature of 60°C to 80°C and refluxed two to three times, with each reflux extraction lasting 1.5 to 2.5 hours.

[0011] In the second step above, the volume ratio of the total extract of Nepeta macrocephala to petroleum ether, dichloromethane, and ethyl acetate is 1:1.

[0012] In the third step above, during gradient elution in silica gel column chromatography, the eluent consists of dichloromethane and methanol in volume ratios of 100:1, 80:1, 50:1, 20:1, 10:1, 5:1, 2:1, and 1:1, respectively.

[0013] In the fourth step above, during gradient elution in silica gel column chromatography, the eluent consists of dichloromethane and methanol in volume ratios of 50:1, 40:1, 30:1, 20:1, 10:1, and 5:1, respectively.

[0014] In the fifth step above, during gradient elution in silica gel column chromatography, the eluent consists of petroleum ether and ethyl acetate in volume ratios of 2:1 and 1:1, and dichloromethane and methanol in volume ratios of 50:1, 40:1, 30:1, 20:1, 10:1, and 5:1, respectively.

[0015] In step six above, during the semi-preparative liquid chromatography gradient elution, the eluent consists of methanol and water in a volume ratio of 55:45.

[0016] The second technical solution of the present invention is achieved through the following measures: a method for preparing biphenyl compounds from Nepeta macrocarpa, which is carried out according to the following method: The first step is to pulverize the large-bracted catnip, soak it in ethanol solution, heat and reflux to extract it, combine the reflux extracts, and recover and concentrate them under reduced pressure to obtain the total extract of large-bracted catnip. The second step involves dispersing the total extract of Nepeta macrocarpa in water into a suspension, and then extracting it sequentially with petroleum ether, dichloromethane, and ethyl acetate. After concentrating the extract, petroleum ether fraction extract, dichloromethane fraction extract, and ethyl acetate fraction extract are obtained. The third step involved separating the dichloromethane fraction using silica gel column chromatography with gradient elution to obtain eight fractions. The fourth step involves separating the fourth of the eight fractions by gradient elution using silica gel column chromatography to obtain six fractions. Fifth step: Separate the third fraction of the obtained 6 fractions by gradient elution using silica gel column chromatography to obtain 8 fractions; Step 6: The fifth fraction of the eight fractions obtained was purified and separated by semi-preparative liquid chromatography gradient elution, and the eluent was collected. At 16.4 minutes, biphenyl compounds from Nepeta macrocarpa were obtained.

[0017] The third technical solution of the present invention is achieved through the following measures: the application of biphenyl compounds from Nepeta macrocephala in the preparation of anti-inflammatory drugs.

[0018] This invention discloses for the first time biphenyl compounds from Nepeta macrocarpa and conducts in vitro anti-inflammatory pharmacodynamic experiments, demonstrating that they have a certain inhibitory effect on RAW264.7 cells and can be applied to the preparation of anti-inflammatory drugs. Attached Figure Description

[0019] Appendix Figure 1 The biphenyl compounds in *Nepeta macrocarpa* in Example 11 of this invention 1 H-NMR spectrum.

[0020] Appendix Figure 2 The biphenyl compounds in *Nepeta macrocarpa* in Example 11 of this invention 13 C-APT spectrum.

[0021] Appendix Figure 3 This is the HH COSY spectrum of biphenyl compounds in Nepeta macrocarpa from Example 11 of this invention.

[0022] Appendix Figure 4 This is the HSQC spectrum of biphenyl compounds in Nepeta macrocarpa from Example 11 of the present invention.

[0023] Appendix Figure 5 This is the HMBC spectrum of biphenyl compounds in Nepeta macrocarpa from Example 11 of the present invention.

[0024] Appendix Figure 6 This is the NOESY spectrum of biphenyl compounds in Nepeta macrocarpa from Example 11 of the present invention. Detailed Implementation

[0025] This invention is not limited to the following embodiments, and specific implementation methods can be determined according to the technical solutions and actual conditions of this invention. Unless otherwise specified, all chemical reagents and chemicals mentioned in this invention are well-known and commonly used chemical reagents and chemicals in the prior art; unless otherwise specified, all percentages in this invention are mass percentages; unless otherwise specified, all solutions in this invention are aqueous solutions with water as the solvent, for example, hydrochloric acid solution is an aqueous solution of hydrochloric acid; room temperature in this invention generally refers to a temperature between 15°C and 25°C, generally defined as 25°C.

[0026] The present invention will be further described below with reference to embodiments: Example 1: The biphenyl compound in this *Nepeta macrocarpa* species, with the Chinese name 4-{4-[(1S)-2-hydroxyethyl]-3-methoxyphenyl}-2,6-dimethoxyphenol, has the following chemical structural formula: .

[0027] Example 2: As an optimization of the above examples, biphenyl compounds from Nepeta macrocarpa were obtained according to the following method: The first step is to pulverize the large-bracted catnip, soak it in ethanol solution, heat and reflux to extract it, combine the reflux extracts, and recover and concentrate them under reduced pressure to obtain the total extract of large-bracted catnip. The second step involves dispersing the total extract of Nepeta macrocarpa in water into a suspension, and then extracting it sequentially with petroleum ether, dichloromethane, and ethyl acetate. After concentrating the extract, petroleum ether fraction extract, dichloromethane fraction extract, and ethyl acetate fraction extract are obtained. The third step involved separating the dichloromethane fraction using silica gel column chromatography with gradient elution to obtain eight fractions. The fourth step involves separating the fourth of the eight fractions by gradient elution using silica gel column chromatography to obtain six fractions. Fifth step: Separate the third fraction of the obtained 6 fractions by gradient elution using silica gel column chromatography to obtain 8 fractions; Step 6: The fifth fraction of the eight fractions obtained was purified and separated by semi-preparative liquid chromatography gradient elution, and the eluent was collected. At 16.4 minutes, biphenyl compounds from Nepeta macrocarpa were obtained.

[0028] Example 3: As an optimization of the above example, in the first step, each 50 kg of Nepeta macrocarpa is extracted with a 90% to 95% ethanol solution by volume, heated to a temperature of 60°C to 80°C and refluxed two to three times, with each reflux extraction lasting 1.5 to 2.5 hours.

[0029] Example 4: As an optimization of the above example, in the second step, the volume ratio of the total extract of Nepeta macrocephala to petroleum ether, dichloromethane and ethyl acetate is 1:1.

[0030] Example 5: As an optimization of the above example, in the third step, during gradient elution of silica gel column chromatography, the eluent is composed of dichloromethane and methanol in volume ratios of 100:1, 80:1, 50:1, 20:1, 10:1, 5:1, 2:1, and 1:1, respectively.

[0031] Example 6: As an optimization of the above example, in the fourth step, during gradient elution of silica gel column chromatography, the eluent is composed of dichloromethane and methanol in volume ratios of 50:1, 40:1, 30:1, 20:1, 10:1, and 5:1, respectively.

[0032] Example 7: As an optimization of the above example, in the fifth step, during gradient elution of silica gel column chromatography, the eluent consists of petroleum ether and ethyl acetate in volume ratios of 2:1 and 1:1, and dichloromethane and methanol in volume ratios of 50:1, 40:1, 30:1, 20:1, 10:1, and 5:1, respectively.

[0033] Example 8: As an optimization of the above example, in step 6, during the semi-preparative liquid chromatography gradient elution, the eluent is composed of methanol and water in a volume ratio of 55:45.

[0034] Example 9: The preparation method of biphenyl compounds from this Nepeta macrocarpa is carried out according to the following method: The first step is to pulverize the large-bracted catnip, soak it in ethanol solution, heat and reflux to extract it, combine the reflux extracts, and recover and concentrate them under reduced pressure to obtain the total extract of large-bracted catnip. The second step involves dispersing the total extract of Nepeta macrocarpa in water into a suspension, and then extracting it sequentially with petroleum ether, dichloromethane, and ethyl acetate. After concentrating the extract, petroleum ether fraction extract, dichloromethane fraction extract, and ethyl acetate fraction extract are obtained. The third step involved separating the dichloromethane fraction using silica gel column chromatography with gradient elution to obtain eight fractions. The fourth step involves separating the fourth of the eight fractions by gradient elution using silica gel column chromatography to obtain six fractions. Fifth step: Separate the third fraction of the obtained 6 fractions by gradient elution using silica gel column chromatography to obtain 8 fractions; Step 6: The fifth fraction of the eight fractions obtained was purified and separated by semi-preparative liquid chromatography gradient elution, and the eluent was collected. At 16.4 minutes, biphenyl compounds from Nepeta macrocarpa were obtained.

[0035] Example 10: Application of biphenyl compounds in the preparation of anti-inflammatory drugs from *Nepeta macrocarpa*.

[0036] Example 11: The biphenyl compounds in this Nepeta macrocarpa were obtained by the following method: The first step is to crush 50 kg of Nepeta macrocarpa, soak it in a 95% ethanol solution, heat it to 70°C and reflux it three times, each time for 2.0 h. Combine the reflux extracts and recover and concentrate them under reduced pressure to obtain the total extract of Nepeta macrocarpa. The second step involves dispersing the total extract of Nepeta macrocarpa in water into a suspension, and then extracting it sequentially with petroleum ether, dichloromethane, and ethyl acetate in a volume ratio of 1:1 to the total extract of Nepeta macrocarpa. After concentrating the extract, petroleum ether extract, dichloromethane extract, and ethyl acetate extract are obtained. The third step involves separating the dichloromethane fraction using silica gel column chromatography with gradient elution (the eluent consists of dichloromethane and methanol in volume ratios of 100:1, 80:1, 50:1, 20:1, 10:1, 5:1, 2:1, and 1:1, respectively), yielding eight fractions. In the fourth step, the fourth fraction of the obtained eight fractions was separated by gradient elution using silica gel column chromatography (the eluent consisted of dichloromethane and methanol in volume ratios of 50:1, 40:1, 30:1, 20:1, 10:1, and 5:1, respectively), resulting in six fractions. In the fifth step, the third fraction of the obtained 6 fractions was separated by silica gel column chromatography gradient elution (the eluent consisted of petroleum ether and ethyl acetate in volume ratios of 2:1 and 1:1, and dichloromethane and methanol in volume ratios of 50:1, 40:1, 30:1, 20:1, 10:1, and 5:1, respectively), to obtain 8 fractions; Step 6: The fifth fraction of the eight fractions was purified and separated by semi-preparative liquid chromatography gradient elution (the eluent consisted of methanol and water in a volume ratio of 55:45), and the eluent was collected. Biphenyl compounds from Nepeta macrocarpa were obtained at 16.4 minutes.

[0037] The biphenyl compound 4-{4-[(1S)-2-hydroxyethyl]-3-methoxyphenyl}-2,6-dimethoxyphenol obtained from Nepeta macrocarpa in Example 11 was subjected to 1H NMR spectroscopy. 1 H-NMR and carbon nuclear magnetic resonance (NMR) 13 C-APT analysis. 1 H-NMR spectrum as shown Figure 1 As shown, 13 C-APT spectrum as shown Figure 2 As shown, the HH COSY spectrum is as follows: Figure 3 As shown, the HSQC spectrum is as follows: Figure 4 As shown, the HMBC spectrum is as follows Figure 5 As shown, the NOESY spectrum is as follows: Figure 6 As shown.

[0038] right Figure 1 and Figure 2Perform spectrum analysis, and analyze spectrum 1 and... Figure 2 Each peak is assigned a location. Figure 1 and Figure 2 The peak assignments are shown in Table 1. The data in Table 1 show that the chemical structure of the biphenyl compound 4-{4-[(1S)-2-hydroxyethyl]-3-methoxyphenyl}-2,6-dimethoxyphenol in the *Nepeta macrocarpa* is shown below, and it is readily soluble in chloroform and methanol. It is readily soluble in chloroform and methanol.

[0039] The structure of the biphenyl compounds in Nepeta macrocarpa of this invention was identified, and the specific process is as follows: 1 The 1H-NMR spectrum shows four aromatic protons with δH: 6.73 (1H,d,J=8.04,H-2), δH: 6.88 (1H,d,J=1.5Hz,H-3), δH: 6.74 (1H,dd,J=8.1,1.62Hz,H-6), and δH: 6.593 (2H,s,H-8 / 12); one methylene proton with δH: 4.13 (1H,dd,J=5.04,8.7Hz,H-14a) and 3.74 (1H,dd,J=9.36,3.3Hz,H-14b); and two -OCH3 signals with δH: 3.75 (3H,s,15-OCH3) and δH: 3.74 (3H,s,9 / 11-OCH3).

[0040] exist 13 In the C-APT spectrum, the resonance signals at δC:147.8,147.5,145.9,134.8,132.5,131.3,118.6,115.1,109.4 and 103.5 are aromatic carbons, and the signals at δC:71.7 and 85.1 are oxygenated carbons.

[0041] In the HSQC spectrum, the correlation between δH:4.13 (1H,dd,J=5.04,8.7Hz,H-14a) and 3.74 (1H,dd,J=9.36,3.3Hz,H-14b) and the oxygen-bound carbon at δC:71.7 indicates that δC:71.7 is a methylene carbon, and that a hydroxyl group is attached to the methylene group; the correlation between δH:4.60 (1H,s,H-13) and the oxygen-bound carbon at δC:85.1 indicates that δ At C:71.7, there is a methine carbon, and a hydroxyl group is attached to the methine. In the HMBC spectrum, the correlation between δH:4.13 (1H,dd,J=5.04,8.7Hz,H-14a) and δH:3.74 (1H,dd,J=9.36,3.3Hz,H-14b) and δC:85.1 and δH:4.60 (1H,s,H-13) and δC:71.7 indicates the presence of an ethylene glycol group in the structure.

[0042] In the HMBC spectrum, long-range correlations were observed between δH: 4.60 (1H, s, H-13) and δC: 109.4 (C-3), 131.4 (C-4), and 147.8 (C-5), indicating that the ethylene glycol branching occurred at C-4; long-range correlations were observed between δH: 3.74 (3H, s) and δC: 147.5 (C-9 / 11) and 103.5 (C-8 / 12), respectively, indicating that two methoxy groups substituted at C-9 and C-11; and long-range correlations were observed between δH: 3.75 (3H, s) and δC: 147.8 (C-13). -5) Long-range correlation exists, indicating that one methoxy group is substituted at C-5; δH: 6.73 (1H,d,J=8.04Hz,H-2) and 6.74 (1H,dd,J=8.1,1.62Hz,H-6) are correlated with δC: 103.5 (C-8 / 12) and δC: 115.1 (C-2) and δC: 118.6 (C-6) respectively, indicating that the two benzene ring systems are connected through C1-C7.

[0043] Therefore, the biphenyl compound in Nepeta macrocarpa was named 4-{4-[(1S)-2-hydroxyethyl]-3-methoxyphenyl}-2,6-dimethoxyphenol.

[0044] The biphenyl compound 4-{4-[(1S)-2-hydroxyethyl]-3-methoxyphenyl}-2,6-dimethoxyphenol from Nepeta macrocarpa of this invention was subjected to in vitro anti-inflammatory pharmacodynamic experiments using the MTT assay.

[0045] The experimental group used 4-{4-[(1S)-2-hydroxyethyl]-3-methoxyphenyl}-2,6-dimethoxyphenol, a biphenyl compound from *Nepeta macrocarpa*, and the control group used indomethacin. A blank group was also set up. RAW264.7 cells (mouse macrophages) were used as experimental subjects in the experimental, control, and blank groups. After dilution of the culture medium, the cells were inoculated at 4 × 10⁻⁶. 5The culture medium was seeded at a density of 100 μL per well in 96-well plates. After normal incubation for 24 hours, the corresponding drugs were added to each group to achieve final drug concentrations of 6.25 μm / mL (Group 1), 12.5 μm / mL (Group 2), 25 μm / mL (Group 3), 50 μm / mL (Group 4), 100 μm / mL (Group 5), and 200 μm / mL (Group 6), for a total of 6 concentrations, with 3 replicates per concentration. After 48 hours of incubation, 10 μL of MTT was added to each well for staining. After another 4 hours of incubation, the original culture medium was discarded, and 150 μL of DMSO was added to each well. The plates were shaken at low speed for 10 min to fully dissolve the crystals. The optical density was measured at 570 nm using an ELISA reader, and the 50% inhibitory concentration (IC50) was calculated based on the optical density. 50 (μg / mL), where the optical density value is calculated using IC. 50 The calculation method is a well-known existing technology.

[0046] The experimental and control groups showed different IC50 values ​​for RAW264.7 cells. 50 As shown in Table 2, the data in Table 2 show that the biphenyl compound 4-{4-[(1S)-2-hydroxyethyl]-3-methoxyphenyl}-2,6-dimethoxyphenol in *Nepeta macrocarpa* of this invention has a certain inhibitory effect on RAW264.7 cells.

[0047] In summary, this invention discloses biphenyl compounds from Nepeta macrocephala for the first time and conducts in vitro anti-inflammatory pharmacodynamic experiments, demonstrating that they have a certain inhibitory effect on RAW264.7 cells and can be applied to the preparation of anti-inflammatory drugs.

[0048] The above technical features constitute the embodiments of the present invention, which have strong adaptability and implementation effect. Unnecessary technical features can be added or removed according to actual needs to meet the needs of different situations.

Claims

1. A biphenyl compound from Nepeta macrocarpa, characterized in that... The chemical structural formula is: 。 2. The biphenyl compound in Nepeta macrocarpa according to claim 1, characterized in that... It is obtained using the following method: The first step is to pulverize the large-bracted catnip, soak it in ethanol solution, heat and reflux to extract it, combine the reflux extracts, and recover and concentrate them under reduced pressure to obtain the total extract of large-bracted catnip. The second step involves dispersing the total extract of Nepeta macrocarpa in water into a suspension, and then extracting it sequentially with petroleum ether, dichloromethane, and ethyl acetate. After concentrating the extract, petroleum ether fraction extract, dichloromethane fraction extract, and ethyl acetate fraction extract are obtained. The third step involved separating the dichloromethane fraction using silica gel column chromatography with gradient elution to obtain eight fractions. The fourth step involves separating the fourth of the eight fractions by gradient elution using silica gel column chromatography to obtain six fractions. Fifth step: Separate the third fraction of the obtained 6 fractions by gradient elution using silica gel column chromatography to obtain 8 fractions; Step 6: The fifth fraction of the eight fractions obtained was purified and separated by semi-preparative liquid chromatography gradient elution, and the eluent was collected. At 16.4 minutes, biphenyl compounds from Nepeta macrocarpa were obtained.

3. The biphenyl compound in Nepeta macrocarpa according to claim 2, characterized in that... In the first step, each 50 kg of Nepeta macrocarpa is extracted with a 90% to 95% ethanol solution by volume, heated to 60°C to 80°C and refluxed two to three times, with each reflux extraction lasting 1.5 to 2.5 hours.

4. The biphenyl compound in Nepeta macrocarpa according to claim 2 or 3, characterized in that... In the second step, the total extract of Nepeta macrocephala was mixed with petroleum ether, dichloromethane, and ethyl acetate in a volume ratio of 1:

1.

5. The biphenyl compound in Nepeta macrocarpa according to any one of claims 2 to 4, characterized in that... In the third step, during gradient elution in silica gel column chromatography, the eluent consists of dichloromethane and methanol in volume ratios of 100:1, 80:1, 50:1, 20:1, 10:1, 5:1, 2:1, and 1:1, respectively.

6. The biphenyl compound in Nepeta macrocarpa according to any one of claims 2 to 5, characterized in that... In the fourth step, during gradient elution in silica gel column chromatography, the eluent consists of dichloromethane and methanol in volume ratios of 50:1, 40:1, 30:1, 20:1, 10:1, and 5:1, respectively.

7. The biphenyl compound in Nepeta macrocarpa according to any one of claims 2 to 6, characterized in that... In the fifth step, during gradient elution in silica gel column chromatography, the eluent consists of petroleum ether and ethyl acetate in volume ratios of 2:1 and 1:1, and dichloromethane and methanol in volume ratios of 50:1, 40:1, 30:1, 20:1, 10:1, and 5:1, respectively.

8. The biphenyl compound in Nepeta macrocarpa according to any one of claims 2 to 7, characterized in that... In step six, during the semi-preparative liquid chromatography gradient elution, the eluent consists of methanol and water in a volume ratio of 55:

45.

9. A method for preparing biphenyl compounds from Nepeta macrocarpa according to any one of claims 3 to 8, characterized in that... Perform the following steps: The first step is to pulverize the large-bracted catnip, soak it in ethanol solution, heat and reflux to extract it, combine the reflux extracts, and recover and concentrate them under reduced pressure to obtain the total extract of large-bracted catnip. The second step involves dispersing the total extract of Nepeta macrocarpa in water into a suspension, and then extracting it sequentially with petroleum ether, dichloromethane, and ethyl acetate. After concentrating the extract, petroleum ether fraction extract, dichloromethane fraction extract, and ethyl acetate fraction extract are obtained. The third step involved separating the dichloromethane fraction using silica gel column chromatography with gradient elution to obtain eight fractions. The fourth step involves separating the fourth of the eight fractions using silica gel column chromatography gradient elution to obtain six fractions. Fifth step: Separate the third fraction of the obtained 6 fractions by gradient elution using silica gel column chromatography to obtain 8 fractions; Step 6: The fifth fraction of the eight fractions obtained was purified and separated by semi-preparative liquid chromatography gradient elution, and the eluent was collected. At 16.4 minutes, biphenyl compounds from Nepeta macrocarpa were obtained.

10. The use of a biphenyl compound from Nepeta macrocephala according to any one of claims 1 to 8 in the preparation of an anti-inflammatory drug.

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