Magnolol / honokiol nitrone derivative and application thereof

Abstract

The invention belongs to the technical field of medicines, and discloses a magnolol / honokiol nitrone derivative as well as a preparation method, a pharmaceutical composition and application thereof. Specifically, the invention discloses magnolol / honokiol nitrone derivatives as shown in a general formula I and a general formula II. The derivatives are prepared in an artificial synthesis mode, pharmaceutical compositions containing the derivatives and application of the derivatives in the anti-inflammatory aspect.

Description

Technical Field

[0001] This invention relates to the fields of natural medicines and medicinal chemistry, specifically to a class of magnolol and / or its nitroketone derivatives. The invention also discloses methods for preparing these derivatives, pharmaceutical compositions, and their uses in treating inflammation. Background Technology

[0002] Inflammation is the body's self-protective response to harmful internal and external stimuli. It is generally classified into acute and chronic inflammation based on its course. Acute inflammation has a rapid onset and short duration, while chronic inflammation lasts longer, sometimes months or years. Inflammation can be beneficial to the body to some extent, but excessive or prolonged inflammatory responses often exacerbate many diseases, such as respiratory inflammation, joint inflammation, skin inflammation, lung inflammation, eye inflammation, and autoimmune diseases. Currently, anti-inflammatory drugs used clinically are mainly divided into two categories: steroidal anti-inflammatory drugs (SIADs) and non-steroidal anti-inflammatory drugs (NSAIDs). However, these drugs have problems such as uncertain efficacy, significant side effects, and high cost. Therefore, actively searching for safe, effective, and long-term usable anti-inflammatory drugs has always been a hot topic for medical professionals.

[0003] Magnolia officinalis, a plant belonging to the genus Magnolia in the family Magnoliaceae, is widely distributed in western Hubei and Sichuan provinces of my country. As a traditional Chinese medicine, Magnolia officinalis has the effects of drying dampness and resolving phlegm, regulating qi and relieving fullness, and is mainly used for patients with spleen and stomach disharmony, abdominal distension, and phlegm-dampness obstruction. Magnolol and honokiol are the two most abundant components in Magnolia officinalis and are also the main active ingredients. Currently, they have been found to have various pharmacological effects such as anti-inflammatory, anti-diarrheal, and hepatoprotective properties, showing good development prospects and potential for use in the development of anti-inflammatory drugs.

[0004] Nitroketones are a class of compounds with strong free radical scavenging capabilities, exhibiting potent scavenging effects against various reactive free radicals. Studies have found that nitroketones have certain therapeutic effects on various free radical-induced diseases (such as cancer, stroke, and Parkinson's disease). Nitric oxide (NO) is a gaseous free radical that, as an inflammatory mediator, plays a complex regulatory role in many aspects of the inflammatory response. Based on research on magnolol and honokiol in the treatment of inflammation, and the powerful free radical scavenging effects of nitroketone compounds, we creatively synthesized a series of magnolol and honokiol nitroketone derivatives, and verified them through pharmacological experiments, thus completing this invention.

[0005] Summary of the Invention

[0006] The technical problem solved by this invention is to provide a class of magnolol and magnolol nitroketone derivatives and their uses.

[0007] This invention discloses compounds of general formulas I and II. Pharmacological experiments have shown that these compounds significantly improve the inflammatory response induced by lipopolysaccharide (LPS) stimulation of Raw264.7 macrophages. Therefore, these compounds can be used to prevent and / or treat various inflammatory diseases, including but not limited to dermatitis, encephalitis, keratitis, conjunctivitis, rhinitis, otitis media, gingivitis, pharyngitis, tonsillitis, pneumonia, hepatitis, enteritis, dysentery, prostatitis, endometritis, cervicitis, pelvic inflammatory disease, paronychia, rheumatoid arthritis, asthma, and psoriasis.

[0008] To solve the technical problem of this invention, the present invention provides the following technical solution:

[0009] The first aspect of the present invention is to provide magnolol nitroketone derivatives of general formula I or pharmaceutically acceptable salts thereof:

[0010]

[0011] R1 is selected from H, CH3, CH2CH3, CH2CH2CH3, CH(CH3)2, CH2CH2CH2CH3;

[0012] R2 is selected from CH3, CH2CH3, CH2CH2CH3, CH(CH3)2, CH2CH2CH2CH3, CH2CH(CH3)2, t-Bu, Ph, Bn;

[0013] This invention relates to the magnolol nitroketone derivatives of formula II or pharmaceutically acceptable salts thereof:

[0014]

[0015] R3 and R4 are independent of each other and can be selected from H or H respectively. Furthermore, R3 and R4 are not both H; R5 is selected from CH3, CH2CH3, CH2CH2CH3, CH(CH3)2, CH2CH2CH2CH3, CH2CH(CH3)2, t-Bu, Ph, and Bn;

[0016] The structures and numbers of some compounds in this invention are as follows:

[0017]

[0018]

[0019] The second aspect of the present invention provides that compounds represented by general formula I can be prepared by the following methods:

[0020]

[0021] The compounds represented by general formula II of this invention can be prepared by the following methods:

[0022]

[0023] The reaction conditions were as follows: (a) Paraformaldehyde, magnesium chloride, triethylamine, anhydrous tetrahydrofuran solvent, heated to 60°C; (b) R₂NHOH, triethylamine, sodium sulfate, ethanol solvent, heated to 90°C; (c) RI, potassium carbonate, tetrahydrofuran solvent, room temperature; (d) i: reactant hexamethylenetetramine, glacial acetic acid solvent, heated to 130°C; II: 33% sulfuric acid, heated to 100°C; (e) 35% sodium hydroxide, chloroform solvent, heated to 60°C.

[0024] In the above compounds, the definitions of R1 and R2 are the same as those for R1 and R2 in general formula I.

[0025] I(a) includes compounds such as HK-1, HK-2, HK-3, HK-4, and HK-5.

[0026] I(b) includes compounds such as HK-6, HK-7, HK-8, HK-9, and HK-10.

[0027] II(a) includes compounds such as HL-1, HL-2, HL-3, HL-4, and HL-5.

[0028] II(b) includes compounds such as HL-6, HL-7, HL-8, HL-9, and HL-10.

[0029] II(c) includes compounds such as HL-11 and HL-12.

[0030] A third aspect of the present invention is to provide a pharmaceutical composition in which the compound described in the first aspect of the present invention is used as an active ingredient. This pharmaceutical composition is prepared according to methods known in the art. It can be formulated into any dosage form suitable for human or animal use by combining the compound of the present invention with one or more pharmaceutically acceptable solid or liquid excipients and / or adjuvants. The content of the compound of the present invention in its pharmaceutical composition is typically 0.1-95% by weight.

[0031] The compounds of this invention or pharmaceutical compositions containing them can be administered in unit dose form via enteral or non-enteric routes, such as oral, intravenous, intramuscular, subcutaneous, nasal, oral mucosa, eye, lung and respiratory tract, skin, vagina, rectum, etc.

[0032] Dosage forms can be liquid, solid, or semi-solid. Liquid dosage forms can include solutions (including true solutions and colloidal solutions), emulsions (including o / w, w / o, and double emulsions), suspensions, injections (including aqueous injections, powder injections, and infusions), eye drops, nasal drops, lotions, and liniments, etc.; solid dosage forms can include tablets (including regular tablets, enteric-coated tablets, lozenges, dispersible tablets, chewable tablets, effervescent tablets, and orally disintegrating tablets), capsules (including hard capsules, soft capsules, and enteric-coated capsules), granules, powders, microcapsules, pellets, suppositories, films, patches, aerosols, and sprays, etc.; semi-solid dosage forms can include ointments, gels, and pastes, etc.

[0033] The compounds of this invention can be formulated into conventional formulations, sustained-release formulations, controlled-release formulations, targeted formulations, and various microparticle delivery systems.

[0034] To formulate the compounds of the present invention into tablets, a wide variety of excipients known in the art can be used, including diluents, binders, wetting agents, disintegrants, lubricants, and flow aids. Diluents can be starch, dextrin, sucrose, glucose, lactose, mannose, sorbitol, xylitol, microcrystalline cellulose, calcium sulfate, dicalcium phosphate, calcium carbonate, etc.; wetting agents can be water, ethanol, isopropanol, etc.; binders can be starch paste, dextrin, syrup, honey, glucose solution, microcrystalline cellulose, gum arabic paste, gelatin paste, sodium carboxymethyl cellulose, methyl cellulose, hydroxypropyl methyl cellulose, ethyl cellulose, acrylic resin, carbomer, polyvinylpyrrolidone, polyethylene glycol, etc.; disintegrants can be dry starch, microcrystalline cellulose, low-substituted hydroxypropyl cellulose, cross-linked polyvinylpyrrolidone, cross-linked sodium carboxymethyl cellulose, sodium carboxymethyl starch, sodium bicarbonate and citric acid, polyoxyethylene sorbitol fatty acid ester, sodium dodecyl sulfonate, etc.; lubricants and flow aids can be talc, silica, stearate, tartaric acid, liquid paraffin, polyethylene glycol, etc.

[0035] Tablets can also be further processed into coated tablets, such as sugar-coated tablets, film-coated tablets, enteric-coated tablets, or bilayer and multilayer tablets.

[0036] To formulate the drug delivery unit into capsules, the active ingredient, the compound of the present invention, can be mixed with a diluent and a disintegrant, and the mixture can be placed directly into hard or soft capsules. Alternatively, the active ingredient, the compound of the present invention, can be first formed into granules or microspheres with a diluent, binder, and disintegrant, and then placed into hard or soft capsules. Various diluents, binders, wetting agents, disintegrants, and disintegrants used to prepare tablets of the compound of the present invention can also be used to prepare capsules of the compound of the present invention.

[0037] To prepare the compounds of this invention into injectable formulations, water, ethanol, isopropanol, propylene glycol, or mixtures thereof can be used as solvents, and appropriate amounts of commonly used solubilizers, co-solvents, pH adjusters, and osmotic pressure adjusters can be added. Solubilizers or co-solvents can be poloxamer, lecithin, hydroxypropyl-β-cyclodextrin, etc. pH adjusters can be phosphates, acetates, hydrochloric acid, sodium hydroxide, etc.; osmotic pressure adjusters can be sodium chloride, mannitol, glucose, phosphates, acetates, etc. If preparing lyophilized powder injections, mannitol, glucose, etc., can also be added as supporting agents.

[0038] In addition, colorants, preservatives, flavorings, tasters or other additives may be added to pharmaceutical preparations if necessary.

[0039] To achieve the purpose of medication and enhance the therapeutic effect, the drug or drug composition of the present invention can be administered using any known method of administration.

[0040] The dosage of the pharmaceutical compositions of the present invention can vary widely depending on the nature and severity of the disease to be prevented or treated, the individual condition of the patient or animal, the route of administration, and the dosage form. Generally, the suitable daily dose range of the compounds of the present invention is 0.001-150 mg / kg body weight, preferably 0.1-100 mg / kg body weight, more preferably 1-60 mg / kg body weight, and most preferably 2-30 mg / kg body weight. The above doses can be administered as a single dose unit or divided into several dose units, depending on the physician's clinical experience and the administration regimen, including the use of other treatment methods.

[0041] The compounds or compositions of the present invention can be taken alone or in combination with other therapeutic or symptomatic drugs. When the compounds of the present invention have a synergistic effect with other therapeutic drugs, their dosage should be adjusted according to the actual situation.

[0042] The compounds represented by general formulas I and II in this invention underwent anti-inflammatory pharmacological experiments. Inflammation is a complex biological process that plays a crucial role in various human diseases. The latest theories of inflammatory responses suggest that pathogens or non-infectious factors can activate endothelial cells in the body, releasing large amounts of inflammatory mediators and pain-inducing substances, including histamine, prostaglandin PGE2, leukotrienes, and nitric oxide (NO); and by activating specific receptors on the surface of immune cells, releasing inflammatory cytokines, including tumor necrosis factor-α (TNF-α), interleukins, and interferons. Therefore, the release of various inflammatory mediators and inflammatory factors is a significant cause of inflammatory responses.

[0043] Lipopolysaccharide (LPS)-induced macrophages are one of the most commonly used in vitro models in inflammation research, characterized by low requirements for model establishment, ease of technique mastery, high reliability, and good reproducibility. LPS activates the immune system, especially macrophages, by releasing various pro-inflammatory mediators. Macrophages, in turn, recognize LPS, activating downstream intracellular signaling cascades, leading to the production of several inflammatory mediators and cytokines (including NO), thereby mediating inflammation. Therefore, in this study, an LPS-stimulated Raw 264.7 macrophage model was used to detect the anti-inflammatory activity of compounds.

[0044] The inventors have discovered that the compounds of general formulas I and II provided by this invention exhibit excellent anti-inflammatory activity in the inflammatory response induced by lipopolysaccharide (LPS) stimulation of macrophages.

[0045] Pharmacological experiments have shown that the compounds represented by general formulas I and II have a good protective effect against lipopolysaccharide (LPS)-induced inflammatory responses and can be used to prepare drugs for the prevention and / or treatment of inflammatory responses.

[0046] The preferred inflammatory diseases are selected from a variety of common inflammatory reactions, such as respiratory system inflammation, musculoskeletal system inflammation, skin inflammation, and autoimmune diseases.

[0047] The fourth aspect of the present invention provides the use of the compound described in the first aspect or a pharmaceutically acceptable salt thereof in the preparation of an anti-inflammatory drug.

[0048] The inflammation mentioned is selected from respiratory system inflammation, musculoskeletal system inflammation, skin inflammation, and autoimmune diseases. Attached Figure Description

[0049] Figure 1 Effects of certain compounds on NO production in LPS-stimulated Raw264.7 macrophages (means±SEM, n=3)

[0050] Figure 2 : Some compounds (with Figure 1 The effect of different (different) on NO production in LPS-stimulated Raw264.7 macrophages (means±SEM, n=3). Detailed Implementation

[0051] Example 1: Preparation of 3-aldehyde-substituted magnolol

[0052]

[0053] Magnoliorol (200 mg, 1 eq) was dissolved in tetrahydrofuran, and paraformaldehyde (90 mg, 4 eq), magnesium chloride (214 mg, 3 eq), and triethylamine (104 μL, 1 eq) were added. The mixture was heated and stirred at 60°C for 10 h, and the reaction was monitored by TLC until completion. The reaction was quenched with 10 mL of water, and the mixture was extracted three times with ethyl acetate (5 mL × 3). The ethyl acetate layers were combined, dried over anhydrous magnesium sulfate, filtered, and the ethyl acetate was evaporated to dryness to obtain the crude product. The crude product was subjected to silica gel column chromatography (petroleum ether: ethyl acetate = 20:3) to give 138 mg of a yellow oil, with a yield of 62%.

[0054] ESI-MS (m / z): 295.1 [M+H] + .

[0055] Example 2: Preparation of 3-methylnitroketone-substituted magnolol (HK-1)

[0056]

[0057] Intermediate 1 (100 mg, 1 eq) was dissolved in 2 mL of ethanol, and then N-methylhydroxylamine hydrochloride (56.6 mg, 2 eq), triethylamine (94 μL, 2 eq), and anhydrous sodium sulfate (144.4 mg, 3 eq) were added. The mixture was heated and stirred at 90°C for 2 h, and the reaction was stopped. The reaction was quenched with 10 mL of water, and the mixture was extracted three times with ethyl acetate (5 mL × 3). The ethyl acetate layers were combined, dried over anhydrous magnesium sulfate, filtered, and the crude product was obtained by rotary evaporation of ethyl acetate. The crude product was subjected to silica gel column chromatography (dichloromethanol = 20:1) to give 98 mg of yellow powder, with a yield of 89%.

[0058] 1 H NMR (400MHz, CDCl3) δ14.39(s,1H),7.59(s,1H),7.35(d,J=2.2Hz,1H),7.13(dd,J=8.2,2.2Hz,1H),7.07(d,J=1.9Hz,1H ),7.00(d,J=8.2Hz,1H),6.92(d,J=2.1Hz,1H),6.03-5.90(m,2H),5.14-5.03(m,4H),3.89(s,3H),3.37(t,J=7.5Hz,4H).

[0059] 13C NMR (100MHz, CDCl3) δ154.19,153.14,142.95,138.07,137.82,137.07,132.58,131.75,131 .61,131.25,130.68,129.64,126.96,118.94,116.97,116.50,115.61,51.96,39.62,39.05.

[0060] ESI-MS (m / z): 324.2 [M+H] + .

[0061] Example 3: Preparation of 3-Isopropylnitroketone-substituted magnolol (HK-2)

[0062] Intermediate 1 (100 mg, 1 eq), N-isopropylhydroxylamine hydrochloride (75.6 mg, 2 eq), triethylamine (94 μL, 2 eq), and anhydrous sodium sulfate (144.4 mg, 3 eq) were synthesized according to the method in Example 2 to obtain 104 mg of a yellow oily substance in 87% yield.

[0063] 1 H NMR (400MHz, CDCl3) δ14.58(s,1H),7.76-7.69(m,1H),7.66(s,1H),7.34(d ,J=2.2Hz,1H),7.12(dd,J=8.2,2.2Hz,1H),7.07(d,J=2.2Hz,1H),7.00(d, J=8.2Hz,1H),6.94(d,J=2.2Hz,1H),6.06-5.89(m,2H),5.09(ddt,J=16.2, 3.6, 1.7Hz, 4H), 4.29 (m, 1H), 3.37 (t, J = 7.3Hz, 4H), 1.53 (d, J = 6.4Hz, 6H).

[0064] 13 C NMR (100MHz, CDCl3) δ154.36,153.24,139.60,138.11,137.43,137.19,132.42,131.77,131.39 ,131.25,130.61,129.51,127.10,118.88,117.13,116.37,115.54,66.54,39.61,39.08,21.06.

[0065] ESI-MS (m / z): 352.2 [M+H] + .

[0066] Example 4: Preparation of 3-tert-butylnitroketone-substituted magnolol (HK-3)

[0067] Intermediate 1 (100 mg, 1 eq), N-tert-butylhydroxylamine (60.4 mg, 2 eq), triethylamine (94 μL, 2 eq), and anhydrous sodium sulfate (144.4 mg, 3 eq) were synthesized according to the method in Example 2 to obtain 107 mg of a yellow oily substance in 86% yield.

[0068] 1 H NMR (400MHz, CDCl3) δ14.56(s,1H),7.79(s,1H),7.35(d,J=2.1Hz,1H),7.12(dd,J=8.2,2.3Hz,1H),7.09- 7.06(m,1H),7.02-6.96(m,2H),6.04-5.89(m,2H),5.13-5.03(m,4H),3.38(t,J=5.5Hz,4H),1.64(s,9H).

[0069] 13 C NMR (100MHz, CDCl3) δ154.63,153.29,138.55,138.15,137.28,137.26,132.32,131.94,131.27 ,131.22,130.75,129.45,127.16,118.84,117.38,116.31,115.50,70.41,39.61,39.12,28.38.

[0070] ESI-MS (m / z): 366.2 [M+H] + .

[0071] Example 5: Preparation of 3-phenylnitroketone-substituted magnolol (HK-4)

[0072] Intermediate 1 (100 mg, 1 eq), phenylhydroxylamine (74.0 mg, 2 eq), triethylamine (94 μL, 2 eq), and anhydrous sodium sulfate (144.4 mg, 3 eq) were synthesized according to the method in Example 2 to obtain 86 mg of orange powder, with a yield of 66%.

[0073] 1H NMR (400MHz, CDCl3) δ14.57(s,1H),8.15(s,1H),7.79(dd,J=6.9,3.0Hz,2H),7.56-7.50(m,3H),7.41(d,J=2.1Hz,1H),7.14(dd,J=8.2,2. 2Hz,1H),7.11-7.06(m,2H),7.02(d,J=8.2Hz,1H),5.98(tdt,J=16.7,9.9,6.7Hz,2H),5.10(dt,J=17.8,7.7Hz,4H),3.40(d,J=6.8Hz,4H).

[0074] 13 C NMR (100MHz, CDCl3) δ154.60,153.10,145.56,141.92,138.36,137.98,136.91,132.51,132.48,131.74, 131.16,130.87,130.83,129.58,129.54,126.84,121.89,118.87,117.26,116.49,115.52,39.53,38.97.

[0075] ESI-MS (m / z): 386.2 [M+H] + .

[0076] Example 6: Preparation of 3-benzylnitroketone-substituted magnolol (HK-5)

[0077] Intermediate 1 (100 mg, 1 eq), N-benzylhydroxylamine (83.5 mg, 2 eq), triethylamine (94 μL, 2 eq), and anhydrous sodium sulfate (144.4 mg, 3 eq) were synthesized according to the method in Example 2 to obtain 102 mg of yellow powder, with a yield of 75%.

[0078] 1 H NMR (400MHz, CDCl3) δ14.38(s,1H),7.56(s,1H),7.46(s,5H),7.33(d,J=2.1Hz,1H),7.12(dd,J=8.2,2.2Hz,1H),7.06(d,J= 2.2Hz,1H),6.99(d,J=8.2Hz,1H),6.86(d,J=2.2Hz,1H),6.06-5.86(m,2H),5.11-5.03(m,6H),3.35(dd,J=16.8,6.7Hz,4H).

[0079] 13C NMR (100MHz, CDCl3) δ154.25,153.15,142.06,138.07,137.80,137.09,132.50,132.08,131.95,131.54,131 .24,130.64,129.76,129.59,129.46,129.38,126.96,118.90,116.91,116.42,115.58,68.63,39.60,39.02.

[0080] ESI-MS (m / z): 400.2 [M+H] + .

[0081] Example 7 Preparation of 4′-methoxymagnolin

[0082]

[0083] Magnolol (200 mg, 1 eq) was dissolved in tetrahydrofuran, and methyl iodide (117 μl, 2.5 eq) and potassium carbonate (260 mg, 2.5 eq) were added. The mixture was stirred overnight at room temperature. After the reaction was complete, 10 mL of water was added to quench the reaction. The mixture was extracted three times with ethyl acetate (5 mL × 3). The ethyl acetate layers were combined, dried over anhydrous magnesium sulfate, filtered, and the ethyl acetate was evaporated to dryness to obtain the crude product. The crude product was subjected to silica gel column chromatography (petroleum ether: ethyl acetate = 20:3) to give 196 mg of a yellow oil, with a yield of 93%.

[0084] ESI-MS (m / z): 281.2 [M+H] + .

[0085] Example 8 Preparation of 3-aldehyde-4′-methoxysubstituted magnolol

[0086]

[0087] Weigh 150 mg (1.5 eq) of hexamethylenetetramine (urotropine) and add it to 2 ml of glacial acetic acid. After stirring and mixing thoroughly, add the mixture to a round-bottom flask containing intermediate 2 (200 mg, 1 eq). Slowly heat to 130°C and stir at this temperature for 3 hours. Cool to 100°C, add 33% (w / w) dilute sulfuric acid solution, and continue stirring for 1 hour to stop the reaction. Quench the reaction with 10 ml of water, extract three times with ethyl acetate (5 ml × 3), combine the ethyl acetate layers, dry to anhydrous magnesium sulfate, filter, and evaporate ethyl acetate to dryness to obtain the crude product. Analyze the crude product by silica gel column chromatography (petroleum ether:ethyl acetate = 20:3) to obtain 193 mg of a yellow oil, yield 88%.

[0088] ESI-MS (m / z): 309.1 [M+H] + .

[0089] Example 9: Preparation of 3-methylnitroketone-4′-methoxysubstituted magnolol (HK-6)

[0090]

[0091] Intermediate 3 (100 mg, 1 eq) was dissolved in 2 mL of ethanol, and then N-methylhydroxylamine hydrochloride (54 mg, 2 eq), triethylamine (90 μL, 2 eq), and anhydrous sodium sulfate (138 mg, 3 eq) were added. The mixture was heated and stirred at 90°C for 2 h, and the reaction was stopped. The reaction was quenched with 10 mL of water, and the mixture was extracted three times with ethyl acetate (5 mL × 3). The ethyl acetate layers were combined, dried over anhydrous magnesium sulfate, filtered, and the crude product was obtained by rotary evaporation of ethyl acetate. The crude product was subjected to silica gel column chromatography (dichloromethanol = 20:1) to give 99 mg of yellow powder, with a yield of 91%.

[0092] 1 H NMR (400MHz, CDCl3) δ7.55(s,1H),7.21(t,J=1.5Hz,1H),7.14(dd,J=8.4,2.3Hz,1H),7.08(d,J=2.2Hz,1H),6.92(d,J=8. 3Hz,1H),6.90-6.88(m,1H),6.02-5.91(m,2H),5.13-5.02(m,4H),3.86(s,3H),3.78(s,3H),3.35(dd,J=16.1,6.7Hz,4H).

[0093] 13 C NMR (100MHz, CDCl3) δ155.70,155.67,142.07,137.99,137.43,136.33,132.04,131.64,130.82 ,130.20,130.11,128.87,127.69,116.88,116.15,115.65,111.55,56.23,52.24,39.56,39.11.

[0094] ESI-MS (m / z): 338.2 [M+H] + .

[0095] Example 10: Preparation of 3-isopropylnitroketone-4′-methoxysubstituted magnolol (HK-7)

[0096] Intermediate 3 (100 mg, 1 eq), N-isopropylhydroxylamine hydrochloride (72.2 mg, 2 eq), triethylamine (90 μL, 2 eq), and anhydrous sodium sulfate (138 mg, 3 eq) were synthesized according to the method described in Example 9 to yield 102 mg of a yellow oily substance in 86% yield.

[0097] 1 H NMR (400MHz, CDCl3) δ12.03(s,1H),7.64(s,1H),7.21(d,J=2.2Hz,1H),7.14(dd,J=8.3,2.3Hz,1H),7.08(d,J=2.3Hz,1H),6.94-6.89(m,2H), 5.97(dtt,J=16.5,9.6,6.6Hz,2H),5.12-5.01(m,4H),4.27(p,J=6.5Hz,1H),3.77(s,3H),3.35(dd,J=12.2,6.7Hz,4H),1.51(d,J=6.5Hz,6H).

[0098] 13 C NMR (100MHz, CDCl3) δ155.74,155.67,138.67,138.02,137.55,135.89,131.90,131.70,130.73,13 0.13,129.92,128.70,127.81,117.11,116.00,115.56,111.50,66.38,56.20,39.55,39.14,21.08.

[0099] ESI-MS (m / z): 366.2 [M+H] + .

[0100] Example 11 Preparation of 3-tert-butylnitroketone-4′-methoxysubstituted magnolol (HK-8)

[0101] Intermediate 3 (100 mg, 1 eq), N-tert-butylhydroxylamine (57.7 mg, 2 eq), triethylamine (90 μL, 2 eq), and anhydrous sodium sulfate (138 mg, 3 eq) were synthesized according to the method described in Example 9 to yield 104 mg of a yellow oily substance, with a yield of 84.5%.

[0102] 1 H NMR (400MHz, CDCl3) δ7.77(s,1H),7.21(d,J=1.9Hz,1H),7.13(dd,J=8.4,2.3Hz,1H),7.08(d,J=2.2Hz,1H),6.94-6. 89(m,2H),6.02-5.90(m,2H),5.11-5.01(m,4H),3.76(d,J=1.2Hz,3H),3.35(t,J=6.5Hz,4H),1.61(d,J=1.2Hz,9H). 13C NMR (100MHz, CDCl3) δ155.71,138.09,137.68,137.46,135.74,131.89,131.76,130.91,130.29 ,129.87,128.67,127.91,117.42,115.96,115.55,111.51,70.06,56.23,39.58,39.21,28.49.

[0103] ESI-MS (m / z): 380.2 [M+H] + .

[0104] Example 12 Preparation of 3-phenylnitrone-4′-methoxysubstituted magnolol (HK-9)

[0105] Intermediate 3 (100 mg, 1 eq), phenylhydroxylamine (70.6 mg, 2 eq), triethylamine (90 μL, 2 eq), and anhydrous sodium sulfate (138 mg, 3 eq) were synthesized according to the method described in Example 9 to obtain 82 mg of orange powder, with a yield of 63%.

[0106] 1 H NMR (400MHz, CDCl3) δ8.10(s,1H),7.77(dd,J=6.1,2.8Hz,2H),7.49(dd,J=4.6,2.5Hz,3H),7.28(d,J=1.7Hz,1H),7.16(dd,J=8.3,2.3Hz,1H),7 .11(d,J=2.1Hz,1H),7.05(d,J=2.1Hz,1H),6.94(d,J=8.3Hz,1H),5.98 (m,2H),5.13-5.05(m,4H),3.80(d,J=1.3Hz,3H),3.37(t,J=7.7Hz,4H).

[0107] 13 C NMR (100MHz, CDCl3) δ155.61,146.47,141.20,137.89,137.27,136.84,131.94,131.57,130.36, 130.27,129.36,128.80,127.56,121.97,117.15,116.12,115.55,111.46,56.16,39.46,39.02.

[0108] ESI-MS (m / z): 400.2 [M+H] + .

[0109] Example 13 Preparation of 3-benzylnitroketone-4′-methoxysubstituted magnolol (HK-10)

[0110] Intermediate 3 (100 mg, 1 eq), N-benzylhydroxylamine (79.7 mg, 2 eq), triethylamine (90 μL, 2 eq), and anhydrous sodium sulfate (138 mg, 3 eq) were synthesized according to the method described in Example 9 to obtain 99 mg of yellow powder, with a yield of 74%.

[0111] 1 H NMR (400MHz, CDCl3) δ7.54(s,1H),7.47-7.40(m,5H),7.20(d,J=2.2Hz,1H),7.13(dd,J=8.2,2.3Hz,1H),7.07(d,J=2.2Hz,1H),6.91(d, J=8.3Hz,1H),6.85(t,J=1.5Hz,1H),5.95(dtd,J=16.7,10.1,6.7Hz,2H),5.11-5.01(m,6H),3.76(s,3H),3.33(dd,J=20.4,6.7Hz,4H).

[0112] 13 C NMR (100MHz, CDCl3) δ155.73,155.63,141.25,137.99,137.46,136.33,132.64,131.99,131.67,130.93,130 .16,130.11,129.44,129.30,128.81,127.65,116.87,116.07,115.62,111.51,68.92,56.20,39.55,39.10.

[0113] ESI-MS (m / z): 414.2 [M+H] + .

[0114] Example 14 Preparation of o-aldehyde substituted magnolol and dialdehyde substituted magnolol

[0115]

[0116] The raw material and magnolol (200 mg, 1 eq) were dissolved in 5 ml of chloroform solution. 1 ml of 35% sodium hydroxide solution and 20 μL of tetrabutylammonium fluoride (0.1 eq) phase transfer catalyst were added. The mixture was heated and stirred at 60°C for 3 h, and the reaction was stopped. 20 ml of water was added to quench the reaction. The mixture was extracted three times with dichloromethane (10 ml × 3). The dichloromethane layers were combined, dried over anhydrous magnesium sulfate, filtered, and the dichloromethane was evaporated to obtain the crude product. The crude product was subjected to silica gel column chromatography (petroleum ether: ethyl acetate = 20:1) to obtain a mixture of intermediates 4 and 5 and 6. The mixture was separated by medium-pressure preparative chromatography. The final yields were: intermediate 4 73 mg (33% yield), intermediate 5 55 mg (25% yield), and intermediate 6 27 mg (11% yield). All three were brown oily substances.

[0117] ESI-MS (m / z): Intermediates 4 and 5: 293.1 [MH] + Intermediate 6: 323.1 [M+H] + .

[0118] Example 15 Preparation of 3′-methylnitroketone-substituted magnolol (HL-1)

[0119]

[0120] Intermediate 4 (100 mg, 1 eq) was dissolved in 2 mL of ethanol. Then, N-methylhydroxylamine hydrochloride (56.6 mg, 2 eq), triethylamine (94 μL, 2 eq), and anhydrous sodium sulfate (144.4 mg, 3 eq) were added. The mixture was heated and stirred at 90°C for 2 h, and the reaction was stopped. The reaction was quenched with 10 mL of water, and the mixture was extracted three times with ethyl acetate (5 mL × 3). The ethyl acetate layers were combined, dried over anhydrous magnesium sulfate, filtered, and the crude product was obtained by rotary evaporation of ethyl acetate. The crude product was subjected to silica gel column chromatography (dichloromethanol = 20:1) to give 98 mg of a yellow powder, with a yield of 89%.

[0121] 1 H NMR (400MHz, CDCl3) δ7.56(s,1H),7.38-7.33(m,2H),6.86(d,J=8.2Hz,1H),6.82(d,J=2.2Hz,1H),5.19(dd,J=20.9,1 3.6Hz, 2H), 5.09 (d, J = 5.7Hz, 1H), 5.06 (s, 1H), 4.99 (s, 1H), 3.89 (s, 3H), 3.46 (d, J = 6.4Hz, 2H), 3.33 (d, J = 6.6Hz, 2H).

[0122] 13C NMR (100MHz, CDCl3) δ155.29,153.51,142.22,137.29,136.55,135.39,132.43,131.63,131 .04,130.44,130.31,129.13,124.72,117.18,116.65,116.08,115.57,52.10,39.02,35.48.

[0123] ESI-MS (m / z): 324.2 [M+H] + .

[0124] Example 16 Preparation of 3′-isopropylnitroketone-substituted magnolol (HL-2)

[0125] Intermediate 4 (100 mg, 1 eq), N-isopropylhydroxylamine hydrochloride (75.6 mg, 2 eq), triethylamine (94 μL, 2 eq), and anhydrous sodium sulfate (144.4 mg, 3 eq) were synthesized according to the method in Example 15 to give 111 mg of a yellow oil, with a yield of 92.5%.

[0126] 1 H NMR (400MHz, CDCl3) δ7.67(s,1H),7.33(d,J=7.4Hz,2H),7.26(d,J=2.5Hz,1H),6.87-6.81(m,2H),5.99(dtt,J=33.6,13.1,5.1H z,2H),5.55(s,1H),5.21-5.04(m,4H),4.29(p,J=6.5Hz,1H),3.44(d,J=6.5Hz,2H),3.33(d,J=6.6Hz,2H),1.53(d,J=6.5Hz,6H).

[0127] . 13 C NMR (100MHz, CDCl3) δ155.32,153.58,139.24,137.50,136.82,135.16,132.63,131.53,130.94 ,130.52,130.35,129.11,125.06,117.46,116.38,116.07,115.57,66.44,39.15,35.34,21.09.

[0128] ESI-MS (m / z): 352.2 [M+H] + .

[0129] Example 17 Preparation of 3′-tert-butylnitroketone-substituted magnolol (HL-3)

[0130] Intermediate 4 (100 mg, 1 eq), N-tert-butylhydroxylamine (60.4 mg, 2 eq), triethylamine (94 μL, 2 eq), and anhydrous sodium sulfate (144.4 mg, 3 eq) were synthesized according to the method in Example 15 to give 110 mg of a yellow oily substance in 89% yield.

[0131] 1 H NMR (400MHz, CDCl3) δ12.17(s,1H),7.80(s,1H),7.34(d,J=6.5Hz,2H),7.26(d,J=2.2Hz,1H),6.88(d,J=2.3Hz,1H),6.83(d,J=8.9Hz,1H) ,6.09-5.90(m,2H),5.36-5.33(m,1H),5.21-5.08(m,3H),5.06(d,J=1.6Hz,1H),3.44(d,J=6.4Hz,2H),3.34(d,J=6.6Hz,2H),1.63(s,9H).

[0132] 13 C NMR (100MHz, CDCl3) δ155.44,153.54,137.90,137.60,136.81,134.94,132.74,131.62,131.15 ,130.53,130.41,129.17,124.92,117.80,116.46,116.03,115.59,70.19,39.21,35.45,28.45.

[0133] ESI-MS (m / z): 366.2 [M+H] + .

[0134] Example 18 Preparation of 3′-phenylnitrone-substituted magnolol (HL-4)

[0135] Intermediate 4 (100 mg, 1 eq), phenylhydroxylamine (74.0 mg, 2 eq), triethylamine (94 μL, 2 eq), and anhydrous sodium sulfate (144.4 mg, 3 eq) were synthesized according to the method described in Example 15 to yield 89 mg of orange powder, with a yield of 68%.

[0136] 1H NMR (400MHz, CDCl3) δ12.44(s,1H),8.12(s,1H),7.78(dd,J=6.7,2.9Hz,2H),7.54-7.47(m,3H),7.39(d,J=7.7Hz,2H),7.32(d,J=2.1H z,1H),6.97(d,J=2.2Hz,1H),6.87(d,J=8.0Hz,1H),6.12-5.91(m,2H),5.26-5.07(m,5H),3.47(d,J=6.4Hz,2H),3.36(d,J=6.6Hz,2H).

[0137] 13 C NMR (100MHz, CDCl3) δ155.90,153.67,146.33,141.66,137.34,136.69,136.14,132.84,131.72,131.28, 131.02,130.82,130.58,129.52,129.23,124.96,122.04,117.65,116.68,116.28,115.70,39.15,35.53.

[0138] ESI-MS (m / z): 386.2 [M+H] + .

[0139] Example 19 Preparation of 3′-benzylnitroketone-substituted magnolol (HL-5)

[0140] Intermediate 4 (100 mg, 1 eq), N-benzylhydroxylamine (83.5 mg, 2 eq), triethylamine (94 μL, 2 eq), and anhydrous sodium sulfate (144.4 mg, 3 eq) were synthesized according to the method described in Example 15 to yield 101 mg of a yellow powder, with a yield of 74%.

[0141] 1 H NMR (400MHz, CDCl3) δ7.56(s,1H),7.48-7.41(m,5H),7.33(d,J=8.0Hz,2H),7.25(s,1H),6.83(d,J=8.0Hz,1H),6.77(d,J=2.1Hz,1H),6 .08-5.87(m,2H),5.31-5.27(m,1H),5.22-5.11(m,2H),5.08(d,J=3.9Hz,3H),5.04(s,1H),3.44(d,J=6.5Hz,2H),3.30(d,J=6.6Hz,2H).

[0142] 13C NMR (100MHz, CDCl3) δ155.43,153.61,141.70,137.42,136.73,135.52,132.60,132.53,131.63,130.96, 130.57,129.50,129.35,129.29,129.16,124.97,117.24,116.56,116.13,115.62,68.86,39.11,35.45.

[0143] ESI-MS (m / z): 400.2 [M+H] + .

[0144] Example 20: Preparation of 3-methylnitroketone-substituted magnolol (HL-6)

[0145]

[0146] Intermediate 5 (100 mg, 1 eq) was dissolved in 2 mL of ethanol, and then N-methylhydroxylamine hydrochloride (56.6 mg, 2 eq), triethylamine (94 μL, 2 eq), and anhydrous sodium sulfate (144.4 mg, 3 eq) were added. The mixture was heated and stirred at 90°C for 2 h, and the reaction was stopped. The reaction was quenched with 10 mL of water, and the mixture was extracted three times with ethyl acetate (5 mL × 3). The ethyl acetate layers were combined, dried over anhydrous magnesium sulfate, filtered, and the crude product was obtained by rotary evaporation of ethyl acetate. The crude product was subjected to silica gel column chromatography (dichloromethanol = 20:1) to give 96 mg of yellow powder, with a yield of 88%.

[0147] 1 H NMR (400MHz, CDCl3) δ12.49(s,1H),7.55(s,1H),7.38(d,J=2.1Hz,1H),7.05(dd,J=8.5,2.2Hz,2H),7.00(d,J=2.2Hz,1H),6.89(d,J=8.2H z,1H),6.07-5.93(m,2H),5.15-5.07(m,3H),5.07(s,1H),5.04(t,J=1.5Hz,1H),3.88(s,3H),3.49(d,J=6.7Hz,2H),3.34(d,J=6.7Hz,2H).

[0148] 13C NMR (100MHz, CDCl3) δ157.45,150.96,142.14,137.83,136.48,134.85,132.53,132.24,130 .58,130.27,129.14,127.82,127.15,116.93,116.21,115.97,115.79,52.24,39.51,34.64.

[0149] ESI-MS (m / z): 324.2 [M+H] + .

[0150] Example 21 Preparation of 3-isopropylnitroketone-substituted magnolol (HL-7)

[0151] Intermediate 5 (100 mg, 1 eq), N-isopropylhydroxylamine hydrochloride (75.6 mg, 2 eq), triethylamine (94 μL, 2 eq), and anhydrous sodium sulfate (144.4 mg, 3 eq) were synthesized according to the method of Example 20 to give 101 mg of a yellow oily substance in 85% yield.

[0152] 1 H NMR (400MHz, CDCl3) δ12.53(s,1H),7.65(s,1H),7.37(d,J=2.1Hz,1H),7.07-7.03(m,2H),7.00(d,J=1.9Hz,1H),6.89(d,J=8.1H z,1H),6.00(m,2H),5.14-5.04(m,5H),4.31(p,J=6.5Hz,1H),3.49(d,J=6.7Hz,2H),3.34(d,J=6.7Hz,2H),1.54(d,J=6.5Hz,6H).

[0153] 13 C NMR (100MHz, CDCl3) δ157.51,150.96,138.74,137.86,136.59,134.51,132.46,132.27,130.51 ,130.25,129.10,127.64,127.26,117.19,116.11,115.88,115.76,66.62,39.51,34.70,21.11.

[0154] ESI-MS (m / z): 352.2 [M+H] + .

[0155] Example 22 Preparation of 3-tert-butylnitroketone-substituted magnolol (HL-8)

[0156] Intermediate 5 (100 mg, 1 eq), N-tert-butylhydroxylamine (60.4 mg, 2 eq), triethylamine (94 μL, 2 eq), and anhydrous sodium sulfate (144.4 mg, 3 eq) were synthesized according to the method of Example 20 to give 104 mg of a yellow oily substance in 84% yield.

[0157] 1 H NMR (400MHz, CDCl3) δ12.46(s,1H),7.78(s,1H),7.37(d,J=2.2Hz,1H),7.09(d,J=2.2Hz,1H),7.07-7.02(m,1H),7.00(d,J=2.1 Hz,1H),6.89(d,J=8.2Hz,1H),6.08-5.92(m,2H),5.14-5.03(m,5H),3.50(d,J=6.6Hz,2H),3.34(d,J=6.6Hz,2H),1.64(s,9H).

[0158] 13 C NMR (100MHz, CDCl3) δ157.63,150.96,137.90,137.47,136.65,134.32,132.43,132.42,130.70 ,130.25,129.10,127.51,127.33,117.54,116.06,115.83,115.73,70.44,39.52,34.72,28.46.

[0159] ESI-MS (m / z): 366.2 [M+H] + .

[0160] Example 23 Preparation of 3-phenylnitrone-substituted magnolol (HL-9)

[0161] Intermediate 5 (100 mg, 1 eq), phenylhydroxylamine (74.0 mg, 2 eq), triethylamine (94 μL, 2 eq), and anhydrous sodium sulfate (144.4 mg, 3 eq) were synthesized according to the method described in Example 20 to give 88 mg of orange powder, with a yield of 67%.

[0162] 1H NMR (400MHz, CDCl3) δ8.11(s,1H),7.78(dd,J=6.6,3.1Hz,2H),7.54-7.48(m,3H),7.45(d,J=2.2Hz,1H),7.19(d,J=2.2Hz,1H) ,7.08-7.01(m,2H),6.89(d,J=8.1Hz,1H),6.11-5.91(m,2H),5.18-5.02(m,5H),3.53(d,J=6.6Hz,2H),3.35(d,J=6.7Hz,2H).

[0163] 13 C NMR (100MHz, CDCl3) δ157.88,150.98,146.20,141.31,137.83,136.47,135.43,132.55,132.50,131.43,130.74, 130.28,129.58,129.39,129.18,128.54,128.10,127.09,121.99,117.29,116.27,116.00,115.80,39.51,34.70.

[0164] ESI-MS (m / z): 386.2 [M+H] + .

[0165] Example 24 Preparation of 3-benzylnitroketone-substituted magnolol (HL-10)

[0166] Intermediate 5 (100 mg, 1 eq), N-benzylhydroxylamine (83.5 mg, 2 eq), triethylamine (94 μL, 2 eq), and anhydrous sodium sulfate (144.4 mg, 3 eq) were synthesized according to the method described in Example 20 to yield 103 mg of yellow powder, with a yield of 76%.

[0167] 1 H NMR (400MHz, CDCl3) δ7.52(s,1H),7.45(m,5H),7.36(d,J=2.1Hz,1H),7.06-7.02(m,1H),6.97(d,J=2.5Hz ,2H),6.87(d,J=8.2Hz,1H),5.99(m,2H),5.14-5.01(m,7H),3.47(d,J=6.7Hz,2H),3.33(d,J=6.7Hz,2H).

[0168] 13C NMR (100MHz, CDCl3) δ157.40,150.82,141.10,137.74,136.38,134.76,132.37,132.19,130.62,130.13, 129.56,129.34,129.32,129.05,127.63,127.04,116.81,116.09,115.79,115.66,68.87,39.39,34.54.

[0169] ESI-MS (m / z): 400.2 [M+H] + .

[0170] Example 25 Preparation of 3,3′-dimethylnitroketone-substituted magnolol (HL-11)

[0171]

[0172] Intermediate 6 (100 mg, 1 eq) was dissolved in 2 mL of ethanol, and then N-methylhydroxylamine hydrochloride (103 mg, 4 eq), triethylamine (172 μL, 4 eq), and anhydrous sodium sulfate (264 mg, 6 eq) were added. The mixture was heated and stirred at 90°C for 2 h, and the reaction was stopped. The reaction was quenched with 10 mL of water, and the mixture was extracted three times with ethyl acetate (5 mL × 3). The ethyl acetate layers were combined, dried over anhydrous magnesium sulfate, filtered, and the crude product was obtained by rotary evaporation of ethyl acetate. The crude product was subjected to silica gel column chromatography (dichloromethanol = 20:1) to give 103 mg of yellow powder, with a yield of 88%.

[0173] 1 H NMR (400MHz, CDCl3) δ12.59(s,1H),12.31(s,1H),7.56(d,J=3.3Hz,2H),7.48(d,J=2.2Hz,1H),7.27-7.22(m,3H),6.82(d,J=2.2Hz,1H) ,6.06(tt,J=13.2,5.0Hz,1H),5.98-5.89(m,1H),5.14-5.04(m,5H),3.87(d,J=8.4Hz,6H),3.49(d,J=6.6Hz,2H),3.32(d,J=6.7Hz,2H).

[0174] 13C NMR (100MHz, CDCl3) δ157.02,155.39,142.61,142.40,137.31,136.96,135.44,135.21,131.55 ,131.41,130.68,130.65,128.90,117.41,116.28,116.14,115.76,52.20,52.13,39.09,34.70.

[0175] ESI-MS (m / z): 381.2 [M+H] + .

[0176] Example 26 Preparation of 3,3′-diisopropylnitroketone-substituted magnolol (HL-12)

[0177] Intermediate 6 (100 mg, 1 eq), N-isopropylhydroxylamine hydrochloride (137 mg, 4 eq), triethylamine (172 μL, 4 eq), and anhydrous sodium sulfate (264 mg, 6 eq) were synthesized according to the method described in Example 25 to yield 119 mg of yellow powder, with a yield of 87.6%.

[0178] 1 H NMR (400MHz, CDCl3) δ12.66(s,1H),12.31(s,1H),7.64(d,J=12.9Hz,2H),7.46(s,1 H),7.28(d,J=2.1Hz,1H),7.22(s,1H),6.85(d,J=2.2Hz,1H),6.06(ddt,J=16.8,10. 2,6.5Hz,1H),5.94(ddt,J=16.5,9.6,6.7Hz,1H),5.14-5.01(m,4H),4.27(dt,J=13. 6,6.07Hz,2H),3.48(d,J=6.5Hz,2H),3.32(d,J=6.6Hz,2H),1.51(d,J=6.6Hz,12H).

[0179] 13 C NMR (100MHz, CDCl3) δ156.94,155.40,139.15,139.02,137.45,137.11,135.06,134.77,131.59,131.42 ,130.54,130.51,130.46,128.93,117.60,116.29,116.11,115.55,66.44,66.33,39.12,34.76,21.08.

[0180] ESI-MS (m / z): 437.2 [M+H]+ .

[0181] Pharmacological experiments:

[0182] Experimental Example 1: Protective effect of compounds HK 1-10 and HL 1-12 on the inflammatory response of LPS-stimulated macrophages Raw264.7

[0183] Methods: Frozen cells were quickly removed from liquid nitrogen and placed in a 37°C water bath, gently shaken to thaw, and 3 mL of preheated to room temperature complete culture medium (DMEM + 10% fetal bovine serum + 1% penicillin-streptomycin mixture) was added. After centrifugation at 800g for 3 min, the supernatant was discarded, and the cells were resuspended and transferred to a culture dish containing fresh complete culture medium. The cells were incubated at 37°C in a CO2 incubator. In this experiment, revived cells were considered stable after two passages before being used in experiments. Raw264.7 cells are semi-adherent cells, appearing round at rest, with several cells clustered in a "grape-like" shape. Cells were passaged when they reached approximately 90% confluence. The culture medium was discarded, fresh complete culture medium was added, and the cells were detached by pipetting. The cell suspension was collected in a centrifuge tube and centrifuged at 800g for 3 min. Discard the supernatant and collect the cell pellet. Add 1 mL of culture medium to resuspend the cell pellet. Gently pipette to disperse the cell pellet into single cells. Inoculate the cells into culture dishes at a ratio of 1:3 and incubate in a CO2 incubator at 37°C.

[0184] Cells were divided at ρ = 5 × 10 5 Cells / mL were evenly seeded into 96-well plates and incubated at 37°C in a CO2 incubator for 17-24 hours before proceeding with the next operation. The cell culture medium was then replaced with starvation medium containing 1% fetal bovine serum (FBS) for 4 hours. After 4 hours, the cell culture medium was replaced with maintenance medium containing 8% FBS, and 10 μL / well of the drug was added for 2 hours of treatment. Then, 1 μg / mL of lipopolysaccharide (LPS) was added for 12 hours of stimulation. The cell culture medium was collected for subsequent experiments.

[0185] NO content was determined using the Griess reagent method: 1% sulfanilamide solution and 0.1% NED solution were prepared and brought to room temperature. 0.1M sodium nitrite was diluted to 100 μM with complete culture medium, and then serially diluted 1:2 to obtain eight standard concentrations. 50 μL / well of sample and standard solutions were added to each well of a 96-well plate. 50 μL / well of 1% sulfanilamide solution was added to each well, and the plate was incubated at room temperature in the dark for 5 min. 50 μL / well of 0.1% NED solution was added to each well; the color reaction should appear immediately, and the plate was incubated at room temperature in the dark for 5 min. The absorbance at 525 nm was recorded from each well. A linear fit was performed on the absorbance of the standard solutions to obtain the linear equation C = a*A525 + b between the concentration C and the absorbance A525. The NO concentration in each sample was then calculated by substituting the sample absorbance into the equation.

[0186] The results are detailed in Table 1. LPS stimulation significantly increased NO secretion by cells, while 10 μmol / L HK 1-10 and HL 1-12 compounds significantly reduced NO secretion and had significant anti-inflammatory effects.

[0187] Table 1. Effects of compounds HK 1-10 and HL 1-12 on NO release from Raw264.7 macrophages after LPS stimulation (means±SEM, n=3)

[0188]

[0189]

Claims

1. A class of magnolol nitrone derivatives represented by the general formula I: ###0001### or a pharmaceutically acceptable salt thereof: R1 is selected from H, CH3, CH2CH3, CH2CH2CH3, CH(CH3)2, CH2CH2CH2CH3; R2 is selected from CH3, CH2CH3, CH2CH2CH3, CH(CH3)2, CH2CH2CH2CH3, CH2CH(CH3)2, t-Bu, Ph, Bn.

2. A class of honokiol nitrone derivatives represented by the general formula II: ###0002### or a pharmaceutically acceptable salt thereof: the compound is selected from the following group: ###0003### 4. A pharmaceutical composition comprising the compound or a pharmaceutically acceptable salt thereof according to any one of claims 1 to 3 as an effective ingredient, and a pharmaceutically acceptable carrier or excipient.

5. Use of the compound or a pharmaceutically acceptable salt thereof according to any one of claims 1 to 3 in the preparation of an anti-inflammatory drug. R3, R4, independently of each other, can be selected from H or and R3, R4are not simultaneously H; R5is selected from CH3, CH2CH3, CH2CH2CH3, CH(CH3)2, CH2CH2CH2CH3, CH2CH(CH3)2, t-Bu, Ph, Bn.

3. The compound according to any one of claims 1 and 2, or a pharmaceutically acceptable salt thereof, characterized in that, the inflammation is selected from respiratory system inflammation, bone and joint system inflammation, skin inflammation, and autoimmune diseases. ​ ​ 6. Use according to claim 5, characterised in that, ​

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