A guaiane sesquiterpene lactone compound, and a preparation method and use thereof

Abstract

The present application relates to a kind of guaiane type sesquiterpene lactone compounds and preparation method and purposes, the guaiane type sesquiterpene lactone compound is from the whole grass of thousand leaf achillea ( Yarrow ​ L.) Is extracted using organic solvent, extraction, then by normal phase silica gel column chromatography, low pressure fast preparation chromatography and two to three methods in semi-preparative high performance liquid chromatography Separation, obtain two new guaiane type sesquiterpene lactone monomer compounds, by high resolution mass spectrometry and nuclear magnetic resonance spectroscopy etc. Method determines two compounds as new guaiane type sesquiterpene lactone compound, and its structure identification is carried out.In addition, the two guaiane type sesquiterpene lactone compounds are determined by microglial cell BV2 to the related activity determination of treating neuroinflammation, and the results show that: the guaiane type sesquiterpene lactone compound can treat neuroinflammation, can be used for anti-neuroinflammatory drug.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medicine, in particular to a quassimarin compound, a preparation method and an application thereof. BACKGROUND

[0002] Neuroinflammation is a complex phenomenon, which has both protective and damaging effects on various nervous system diseases. Inflammation is a natural defense mechanism for the initial infection, trauma and other injuries, but in chronic diseases, persistent neuroinflammation leads to a cycle of neuronal damage and degeneration. Over-activation of glial cells, including microglia and astrocytes, is a characteristic of chronic neuroinflammation, and these cells release pro-inflammatory cytokines, chemokines and reactive oxygen species, which exacerbate neuronal damage and lead to progressive neurodegeneration in neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, Huntington's disease, multiple sclerosis and the like.

[0003] Quassimarin compounds are important active compounds that exist naturally, and their structural characteristics are a typical [5,7] fused ring structure. So far, a few natural quassimarin compounds have been found to have the effect of inhibiting neuroinflammation, such as 2,3- open ring quassimarin compounds found by the previous group from Achillea millefolium L. and quassimarin compounds found in chicory. These findings provide new understanding of quassimarin compounds in the treatment of neuroinflammation-related diseases. SUMMARY

[0004] The present application aims to provide a quassimarin compound, a preparation method and an application thereof. The quassimarin compound is obtained by extracting the whole grass of Achillea millefolium L. with an organic solvent, then using two or three of normal phase silica gel column chromatography, medium and low pressure rapid preparation chromatography and semi-preparative high performance liquid chromatography for separation, obtaining two new quassimarin monomer compounds, determining them as new quassimarin compounds by high resolution mass spectrometry, nuclear magnetic resonance spectroscopy and the like, and identifying their structures. The quassimarin compound of the present application is used in the preparation of a drug for treating neuroinflammation.

[0005] The quassimarin compound of the present application has the following structural formula:

[0006]

[0007] (1R,5R,6S,7R,8S,10S,11S)-2-keto-8-hydroxy-1,10-epoxy-guai-3-ene-12,6-olide;

[0008] (1S,2R,3S,4R,5R,6S,7R,8S,10S,11S)-1,10-epoxy-2,3-dihydroxy-4-chloro-8-[(Z)-2-methyl-2-butenoyloxy]-guaia-1-ene-12,6-olide.

[0009] The preparation method of the one guaiane type sesquiterpene lactone compound is carried out according to the following steps:

[0010] a. Taking the whole grass of achillea as raw material, crushing and then performing room temperature percolation or cold soaking extraction with 4-8 times amount of 50-95% volume concentration ethanol aqueous solution or 50-95% volume concentration methanol aqueous solution, and then evaporating the solvent under reduced pressure at 45 DEG C to obtain the crude extract of achillea;

[0011] b. Dispersing the crude extract obtained in step a with water, and then adding petroleum ether or n-hexane, ethyl acetate, dichloromethane or chloroform for 3-5 times of extraction, and then concentrating the ethyl acetate, dichloromethane or chloroform extractive solution to obtain the ethyl acetate, dichloromethane or chloroform extractive extract;

[0012] c. Separating the ethyl acetate, dichloromethane or chloroform extractive extract obtained in step b by two to three methods of normal phase silica gel column chromatography, medium and low pressure rapid preparation chromatography and semi-preparation high performance liquid chromatography, to obtain (1R,5R,6S,7R,8S,10S,11S)-2-keto-8-hydroxy-1,10-epoxy-guai-3-ene-12,6-olide and (1S,2R,3S,4R,5R,6S,7R,8S,10S,11S)-1,10-epoxy-2,3-dihydroxy-4-chloro-8-[(Z)-2-methyl-2-butenoyloxy]-guaia-1-ene-12,6-olide.

[0013] The normal phase silica gel column chromatography used in step c is atmospheric pressure or pressurized column chromatography, and the filler used is normal phase silica gel; the medium and low pressure preparation chromatography used is pressurized column chromatography, and the column chromatography filler used is reverse phase ODS silica gel; and the semi-preparation high performance liquid chromatography used is pressurized column.

[0014] The two separation modes in step c are:

[0015] c, the ethyl acetate, dichloromethane or chloroform extract obtained in step b is subjected to normal phase silica gel column chromatography, gradient elution is performed with chloroform-methanol or dichloromethane-methanol in a volume ratio of 100:1-0:1, fraction F of 20:1-50:1 is collected, and semi-preparative high performance liquid chromatography is performed on F with methanol-water solution in a concentration gradient of 20%-99% or acetonitrile-water solution in a concentration gradient of 10%-99% to obtain the compound (1R, 5R, 6S, 7R, 8S, 10S, 11S)-2-keto-8-hydroxy-1, 10-epoxy-guaiene-3-ene-12, 6-lactone of formula (I) and the compound (1S, 2R, 3S, 4R, 5R, 6S, 7R, 8S, 10S, 11S)-1, 10-epoxy-2, 3-dihydroxy-4-chloro-8-[(Z)-2-methyl-2-butenoyloxy]-guaiene-1-ene-12, 6-lactone of formula (II).

[0016] The three separation methods in step c are as follows:

[0017] c, the ethyl acetate, dichloromethane or chloroform extract obtained in step b is subjected to normal phase silica gel column chromatography, gradient elution is performed with chloroform-methanol or dichloromethane-methanol in a volume ratio of 100:1-0:1, fraction F of 20:1-50:1 is collected, and semi-preparative high performance liquid chromatography is performed on F with methanol-water solution in a concentration gradient of 20%-99% or acetonitrile-water solution in a concentration gradient of 10%-99% to obtain the compound (1R, 5R, 6S, 7R, 8S, 10S, 11S)-2-keto-8-hydroxy-1, 10-epoxy-guaiene-3-ene-12, 6-lactone of formula (I) and the compound (1S, 2R, 3S, 4R, 5R, 6S, 7R, 8S, 10S, 11S)-1, 10-epoxy-2, 3-dihydroxy-4-chloro-8-[(Z)-2-methyl-2-butenoyloxy]-guaiene-1-ene-12, 6-lactone of formula (II).

[0018] The use of the guaiane type sesquiterpene lactone compound in the preparation of a drug for treating neuroinflammation.

[0019] The guaiane type sesquiterpene lactone compound according to the present application can be obtained by isolation and purification from plants or synthesized by chemical modification methods well known to those skilled in the art.

[0020] The compound is (1R, 5R, 6S, 7R, 8S, 10S, 11S)-2-keto-8-hydroxy-1, 10-epoxy-guaiarene-3-ene-12, 6-lactone, colorless needle crystal, [alpha]

[0021] The compound of formula (I) is (1R, 5R, 6S, 7R, 8S, 10S, 11S)-2-keto-8-hydroxy-1, 10-epoxy-guaiarene-3-ene-12, 6-lactone, colorless needle crystal, [alpha] 20 D -8 (concentration 0.1, methanol); ultraviolet (methanol) 218.1 nm; circular dichroism absorption (methanol) 230 (Delta epsilon-4.19); and the molecular formula of the compound is C + m / z 437.1330 (calculated value is 437.1338) determines that the molecular formula of the compound is C 15 H 18 O5; according to 1 H, 13 C NMR and two-dimensional nuclear magnetic resonance data determine that the structure skeleton type of the compound is guaiarene sesquiterpene lactone, which is named as (1R, 5R, 6S, 7R, 8S, 10S, 11S)-2-keto-8-hydroxy-1, 10-epoxy-guaiarene-3-ene-12, 6-lactone; the compound has the following properties: 1 H and 13 C NMR assignment is shown in Table 1 [600MHz( 1 H), 150MHz( 13 C), deuterated chloroform].

[0022] The compound of formula (II) is (1S, 2R, 3S, 4R, 5R, 6S, 7R, 8S, 10S, 11S)-1, 10-epoxy-2, 3-dihydroxy-4-chloro-8-[(Z)-2-methyl-2-butenoyloxy]-guaiarene-1-ene-12, 6-lactone, white amorphous powder, [alpha] 20 D -8 (concentration 0.1, methanol); ultraviolet (methanol) 218.1 nm; circular dichroism absorption (methanol) 230 (Delta epsilon-4.19); and the molecular formula of the compound is C + m / z 437.1330 (calculated value is 437.1338) determines that the molecular formula of the compound is C 20 H 27 O7Cl; according to 1 H, 13C NMR and two-dimensional nuclear magnetic resonance data determined its structural skeleton type as guaiane type sesquiterpene lactone compound, named 1S,2R,3S,4R,5R,6S,7R,8S,10S,11S)-1,10-epoxy-2,3-dihydroxy-4-chloro-8-[(Z)-2-methyl-2-butenoxy]-guaia-1-ene-12,6-lactone; its 1 H and 13 C NMR assignment see Table 1 [600MHz ( 1 H), 150MHz ( 13 C), deuterated chloroform].

[0023] Table 1. Formula (I) and formula (II) compounds of 1 H and 13 C NMR data [δ (ppm), J (Hz)]

[0024]

[0025] BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 Formula (I) compound of the present application 1 H NMR (600MHz, CDCl3) spectrum;

[0027] Figure 2 Formula (I) compound of the present application 13 C NMR (150MHz, CDCl3) spectrum;

[0028] Figure 3 Formula (II) compound of the present application 1 H NMR (600MHz, CDCl3) spectrum;

[0029] Figure 4 Formula (II) compound of the present application 13 C NMR (150MHz, CDCl3) spectrum. DETAILED DESCRIPTION

[0030] All reagents used are of analytical purity, and acetonitrile used in HPLC is of HPLC grade (Merck, Germany). Column chromatography normal phase silica gel (100-200 mesh, 200-300 mesh) is produced by Qingdao Marine Chemical Factory; reverse phase silica gel ODS is produced by Merck, Germany; medium-low pressure preparative chromatography Sepacore (Switzerland) is configured as follows: C-620 control system, C-660 flow fraction collector, C-640 UV detector, C-605 pump; high performance liquid chromatography (Dionex, USA) is configured as follows: P680 HPLC pump, ASI-100 automatic sampler, TCC-100 column oven, UVD170U UV detector (four wavelengths), four-component solvent system, online degassing machine, chameleon chromatography workstation. Preparative high performance liquid chromatography (Dionex, USA) is configured as follows: P680 HPLC pump, UVD170U UV detector (four wavelengths), four-component solvent system, online degassing machine, chameleon chromatography workstation; mass spectrometry is determined by quadrupole-time-of-flight hybrid mass spectrometer (Applied Biosystems, USA); nuclear magnetic resonance is determined by VARIAN VNMRS 600MHz nuclear magnetic resonance spectrometer; ECD spectral data is obtained by Chirascan circular dichroism spectrometer (UK).

[0031] The whole plant of Achillea millefolium L. is collected from Changji region of Xinjiang Uygur Autonomous Region, and is identified by Lu Chunfang, Associate Researcher of Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, as Achillea millefolium L.

[0032] Example 1

[0033] Two separation methods:

[0034] a. Take 5 kg of the whole plant of Achillea millefolium L. as raw material, crush it, and then perform cold soaking extraction at room temperature using 4 times the volume of 95% ethanol aqueous solution, evaporate the solvent at 45°C under reduced pressure to obtain the crude extract of Achillea millefolium L.

[0035] b. Disperse the crude extract obtained in step a. with water, and sequentially add petroleum ether and ethyl acetate for extraction 3 times, combine the ethyl acetate layers, and evaporate the solvent under reduced pressure to obtain the ethyl acetate extract extractive;

[0036] c, the ethyl acetate extract obtained in step b is successively subjected to normal phase silica gel column chromatography, gradient elution is performed with chloroform-methanol (100:1-0:1) as the eluent, fraction F of 20:1-50:1 is collected; fraction F is subjected to semi-preparative high performance liquid chromatography, gradient elution is performed with methanol-water solution (20%-99%) as the eluent, to obtain (1R, 5R, 6S, 7R, 8S, 10S, 11S)-2-keto-8-hydroxy-1, 10-epoxy-guaiene-3-ene-12, 6-olide of formula (I) and (1S, 2R, 3S, 4R, 5R, 6S, 7R, 8S, 10S, 11S)-1, 10-epoxy-2, 3-dihydroxy-4-chloro-8-[(Z)-2-methyl-2-butenoyloxy]-guaiene-1-ene-12, 6-olide of formula (II).

[0037] Example 2

[0038] Two separation methods:

[0039] a, take the whole herb of achillea as 5 kg, crush it and then perform percolation extraction at room temperature with 8 times the amount of 50% ethanol aqueous solution, evaporate the solvent at 45℃ under reduced pressure to obtain the crude extract of achillea;

[0040] b, disperse the crude extract obtained in step a with water, successively add n-hexane and dichloromethane for extraction 4 times, combine the dichloromethane layers and evaporate under reduced pressure to obtain the dichloromethane extract extract;

[0041] c, the dichloromethane extract extract obtained in step b is subjected to normal phase silica gel column chromatography, gradient elution is performed with dichloromethane-methanol (100:1-0:1) as the eluent, fraction F of 20:1-50:1 is collected; fraction F is subjected to semi-preparative high performance liquid chromatography, gradient elution is performed with acetonitrile-water solution (10%-99%) as the eluent, to obtain (1R, 5R, 6S, 7R, 8S, 10S, 11S)-2-keto-8-hydroxy-1, 10-epoxy-guaiene-3-ene-12, 6-olide of formula (I) and (1S, 2R, 3S, 4R, 5R, 6S, 7R, 8S, 10S, 11S)-1, 10-epoxy-2, 3-dihydroxy-4-chloro-8-[(Z)-2-methyl-2-butenoyloxy]-guaiene-1-ene-12, 6-olide of formula (II).

[0042] Example 3

[0043] Three separation methods:

[0044] a, take the whole herb of achillea as 5 kg, crush it and then perform percolation extraction at room temperature with 4 times the amount of 95% methanol aqueous solution, evaporate the solvent at 45℃ under reduced pressure to obtain the crude extract of achillea;

[0045] b. The crude extract obtained in step a is dispersed in water, and then petroleum ether and chloroform are added successively to extract 5 times. The chloroform layers are combined and evaporated under reduced pressure to obtain the chloroform extract;

[0046] c. The chloroform extract obtained in step b is subjected to normal phase silica gel column chromatography, and eluted with chloroform-methanol solution (100:1-0:1 by volume) by gradient elution. Fraction F of 20:1-50:1 is collected, and then subjected to semi-preparative chromatography under medium-low pressure, and eluted with methanol-water solution (20%-99%) by gradient elution. Fraction F30-70 of 30-70% methanol-water solution is collected, and then subjected to semi-preparative high performance liquid chromatography, and eluted with methanol-water solution (30%-80%) by gradient elution to obtain (1R,5R,6S,7R,8S,10S,11S)-2-oxo-8-hydroxy-1,10-epoxy-guaiaretic-3-ene-12,6-lactone of formula (I) and (1S,2R,3S,4R,5R,6S,7R,8S,10S,11S)-1,10-epoxy-2,3-dihydroxy-4-chloro-8-[(Z)-2-methyl-but-2-enoxy]-guaiaretic-1-ene-12,6-lactone of formula (II).

[0047] Example 4

[0048] Three separation methods:

[0049] a. 5 kg of whole plant of Achillea aspera is taken, crushed, and then subjected to percolation extraction at room temperature with 8 times the amount of 50% methanol aqueous solution. The solvent is evaporated under reduced pressure to obtain the crude extract of Achillea aspera;

[0050] b. The crude extract obtained in step a is dispersed in water, and then petroleum ether and chloroform are added successively to extract 5 times. The chloroform layers are combined and evaporated under reduced pressure to obtain the chloroform extract;

[0051] c, the dichloromethane extract obtained in step b is subjected to column chromatography on normal silica gel, gradient elution is performed with dichloromethane-methanol (100:1-0:1 by volume ratio) as the eluent, fractions F of 20:1-50:1 are collected, fraction F is subjected to semi-preparative chromatography under medium-low pressure, gradient elution is performed with methanol-water solution of concentration 10%-99%, fractions F30-70 of 30-70% methanol-water solution elution are collected, F30-70 is subjected to semi-preparative high performance liquid chromatography, gradient elution is performed with methanol-water solution of concentration 30-80%, to obtain (1R, 5R, 6S, 7R, 8S, 10S, 11S)-2-keto-8-hydroxy-1, 10-epoxy-guaiene-3-ene-12, 6-olide of formula (I) and (1S, 2R, 3S, 4R, 5R, 6S, 7R, 8S, 10S, 11S)-1, 10-epoxy-2, 3-dihydroxy-4-chloro-8-[(Z)-2-methyl-2-butenoyloxy]-guaiene-1-ene-12, 6-olide of formula (II).

[0052] Example 5

[0053] Three separation methods:

[0054] a, take the whole herb of achillea as 5 kg, crush and soak in 6 times the volume of 70% ethanol aqueous solution, evaporate the solvent under reduced pressure to obtain the crude extract of achillea;

[0055] b, disperse the crude extract obtained in step a with water, add petroleum ether and ethyl acetate successively, extract 3 times with ethyl acetate, combine the ethyl acetate layers and evaporate the solvent under reduced pressure to obtain the ethyl acetate extract;

[0056] c, the ethyl acetate extract obtained in step b is subjected to column chromatography on normal silica gel, gradient elution is performed with dichloromethane-methanol (100:1-0:1 by volume ratio) as the eluent, fractions F of 20:1-50:1 are collected, fraction F is subjected to semi-preparative chromatography under medium-low pressure, gradient elution is performed with methanol-water solution of concentration 10%-99%, fractions F30-70 of 30-70% methanol-water solution elution are collected, F30-70 is subjected to semi-preparative high performance liquid chromatography, gradient elution is performed with methanol-water solution of concentration 30-80%, to obtain (1R, 5R, 6S, 7R, 8S, 10S, 11S)-2-keto-8-hydroxy-1, 10-epoxy-guaiene-3-ene-12, 6-olide of formula (I) and (1S, 2R, 3S, 4R, 5R, 6S, 7R, 8S, 10S, 11S)-1, 10-epoxy-2, 3-dihydroxy-4-chloro-8-[(Z)-2-methyl-2-butenoyloxy]-guaiene-1-ene-12, 6-olide of formula (II).

[0057] Example 6

[0058] The application of the guaiane sesquiterpene lactone compound isolated from the whole grass of achillea paniculata in the preparation of a medicine for treating neuroinflammation is disclosed, taking microglia cells (BV2) as an example.

[0059] Cell culture:

[0060] Microglia cells (BV2) (purchased from BeNa Culture Collection, BNCC) were cultured in a high-sugar dulbecco's modified eagle medium (DMEM) medium containing 10% fetal bovine serum (FBS) (purchased from Giboco Company, USA) and 1% penicillin and streptomycin at a temperature of 37°C and in a 5% carbon dioxide incubator.

[0061] 1. Test of the effect of the compound on cell viability:

[0062] When the recovered BV2 cells grow to 80-90%, the cells in good condition are passaged according to the cell state, stained with trypan blue, 10 microliters of trypan blue are added to 10 microliters of cell suspension, mixed thoroughly, and then added to a cell counting plate for counting by a cell counter. The cells are uniformly spread in a 96-well plate at a density of 5×10 3 Each well is added with 0.5 mg / mL (3-(4,5-dimethylthiazole-2)-2,5-diphenyl tetrazolium bromide) (MTT) 100 microliters, and incubated at a temperature of 37°C and in a 5% carbon dioxide incubator for 3-4 hours, and then the culture is terminated. The liquid in the well is aspirated, 150 microliters of dimethyl sulfoxide (DMSO) is added to each well, and shaken for 10 minutes to dissolve the crystals in the cells. The absorbance value of each well is measured by a microplate reader at a wavelength of 490 nm. The cell survival rate is calculated according to the following formula:

[0063] Cell proliferation activity (%) = (A 样品 -A 零孔 ) / (A 对照 -A 零孔 )×100%;

[0064] 2. Nitric oxide (NO) content determination:

[0065] The nitric oxide release amount in the microglial cells is tested by using the Bicun Tian method, and after confirming that the drug concentration has no obvious influence on the cell viability, 100, 50, 25, 12.5 and 6.25 micromoles of the sample are added respectively for incubation for 2 hours, then 1 microgram / milliliter of lipopolysaccharide is added for co-incubation for 22 hours, after the incubation is completed, the cell supernatant is collected, and the content of nitric oxide in the cell supernatant is determined by using the Bicun Tian method; before determination, the Bicun Tian reagent I and II are taken out and restored to room temperature; the standard (1-100 micromoles) is diluted by using the complete culture medium; the concentration of the standard can be 0, 1, 2, 5, 10, 20, 40, 60, 100 micromoles, 50 microliters per hole, the standard and the collected culture supernatant are added in the 96-hole plate, 50 microliters of the Bicun Tian reagent I and 50 microliters of the Bicun Tian reagent II which are restored to room temperature are added in each hole in turn, and after oscillation and mixing for 5 minutes, the absorbance is determined at 540 nanometers, a standard curve is drawn, and the content of nitric oxide in the culture supernatant is calculated according to the standard curve;

[0066] 3. Experimental results:

[0067] The compound of formula (I) and formula (II) obtained in the application has no obvious cytotoxicity to microglial cells at a test concentration; the compound of formula (I) and formula (II) can significantly inhibit the content of nitric oxide in the microglial cells induced by lipopolysaccharide, and the half-inhibition rate IC 50 of the content of nitric oxide is 4.01±0.19 and 46.10±0.52 micromoles respectively;

[0068] The above results show that the compound of formula (I) and formula (II) can reduce the release of nitric oxide in the microglial cells induced by lipopolysaccharide, has the effect of treating neuroinflammation, and can be applied to the drug use for treating neuroinflammation related diseases.

Claims

1. An ent -kaurene diterpene lactone compound, characterized by The structural formula of the compound is: The compound of formula (I) is (1R, 5R, 6S, 7R, 8S, 10S, 11S)-2-keto-8-hydroxy-1, 10-epoxy-guaiaretic-3-ene-12, 6-lactone; The compound of formula (II) is (1S, 2R, 3S, 4R, 5R, 6S, 7R, 8S, 10S, 11S)-1, 10-epoxy-2, 3-dihydroxy-4-chloro-8-[(Z)-2-methyl-2-butenoyloxy]-guaiaretic-1-ene-12, 6-lactone.

2. The method according to claim 1, wherein the compound is prepared by the following steps: (1) culturing the plant of the genus Isodon in a culture medium; (2) extracting the plant of the genus Isodon with a solvent; (3) separating the compound from the solvent; and (4) purifying the compound. The following steps are taken: a. Take the whole grass of achillea as raw material, crush it, and then perform room temperature percolation or cold extraction with 4-8 times the volume of 50-95% ethanol aqueous solution or 50-95% methanol aqueous solution; dry the solvent under reduced pressure at a temperature of 45℃ to obtain the crude extract of achillea; b. Disperse the crude extract obtained in step a with water, and sequentially add petroleum ether or n-hexane, ethyl acetate, dichloromethane or chloroform for 3-5 times of extraction; concentrate the ethyl acetate, dichloromethane or chloroform extract to obtain the ethyl acetate, dichloromethane or chloroform extract extractive; c. Separate the ethyl acetate, dichloromethane or chloroform extract extractive obtained in step b by two to three of normal phase silica gel column chromatography, medium and low pressure rapid preparation chromatography and semi-preparative high performance liquid chromatography, to obtain the compound of formula (I) (1R, 5R, 6S, 7R, 8S, 10S, 11S)-2-keto-8-hydroxy-1, 10-epoxy-guaiaretic-3-ene-12, 6-lactone and the compound of formula (II) (1S, 2R, 3S, 4R, 5R, 6S, 7R, 8S, 10S, 11S)-1, 10-epoxy-2, 3-dihydroxy-4-chloro-8-[(Z)-2-methyl-2-butenoyloxy]-guaiaretic-1-ene-12, 6-lactone.

3. The method for preparing guaiacane-type sesquiterpene lactone compounds according to claim 2, characterized in that... The normal phase silica gel column chromatography used in step c is atmospheric pressure or pressurized column chromatography, and the filler used is normal phase silica gel; the medium and low pressure preparation chromatography used is pressurized column chromatography, and the column chromatography filler used is reverse phase ODS silica gel; the semi-preparative high performance liquid chromatography used is pressurized column chromatography.

4. The method for preparing a guaiacane-type sesquiterpene lactone compound according to claim 2, characterized in that... The two separation methods in step c are: c. The ethyl acetate, dichloromethane or chloroform extract obtained in step b is subjected to column chromatography on normal silica gel, eluting with a gradient of chloroform-methanol or dichloromethane-methanol in a volume ratio of 100:1 to 0:1, and collecting fractions F in the range of 20:1 to 50:

1. Fractions F are subjected to semi-preparative high-performance liquid chromatography, eluting with a gradient of methanol-water in a concentration range of 20% to 99% or acetonitrile-water in a concentration range of 10% to 99%, to obtain (1R, 5R, 6S, 7R, 8S, 10S, 11S)-2-oxo-8-hydroxy-1, 10-epoxy-guai-3-ene-12, 6- lactone of formula (I) and (1S, 2R, 3S, 4R, 5R, 6S, 7R, 8S, 10S, 11S)-1, 10-epoxy-2, 3-dihydroxy-4-chloro-8-[(Z)-2-methyl-2-butenoyloxy]-guaia-1-ene-12, 6-lactone of formula (II).

5. The method for preparing a guaiacane-type sesquiterpene lactone compound according to claim 2, characterized in that... The three separation methods in step c are: c. The ethyl acetate, dichloromethane or chloroform extract obtained in step b is subjected to column chromatography on normal silica gel, eluting with a gradient of chloroform-methanol or dichloromethane-methanol in a volume ratio of 100:1 to 0:1, and collecting fractions F in the range of 20:1 to 50:

1. Fractions F are subjected to semi-preparative high-performance liquid chromatography, eluting with a gradient of methanol-water in a concentration range of 20% to 99% or acetonitrile-water in a concentration range of 10% to 99%, to obtain (1R, 5R, 6S, 7R, 8S, 10S, 11S)-2-oxo-8-hydroxy-1, 10-epoxy-guai-3-ene-12, 6- lactone of formula (I) and (1S, 2R, 3S, 4R, 5R, 6S, 7R, 8S, 10S, 11S)-1, 10-epoxy-2, 3-dihydroxy-4-chloro-8-[(Z)-2-methyl-2-butenoyloxy]-guaia-1-ene-12, 6-lactone of formula (II).

6. Use of a guaiane sesquiterpene lactone compound as claimed in claim 1 in the preparation of a medicament for treating neuroinflammation.

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