Use of a forskolin oxabicyclic derivative for the preparation of an anti-inflammatory medicament

Abstract

The application belongs to the technical field of pharmaceutical chemistry and pharmacology, and relates to application of a forskolin oxygen bridge ring derivative in preparation of anti-inflammatory drugs. The forskolin oxygen bridge ring derivative has a chemical structural formula shown in formula (I), is obtained by reacting forskolin and potassium hydroxide in methanol to obtain forskolin rearrangement product 1, and then reacting the forskolin rearrangement product 1 with aryl iodide in anhydrous dichloroethane under the catalysis of anhydrous silver acetate, anhydrous copper acetate and palladium acetate to obtain the forskolin oxygen bridge ring derivative (I). The forskolin oxygen bridge ring derivative obtained by the application has relatively strong anti-inflammatory activity, and the activity is equivalent to that of dexamethasone, and can be used for preparing anti-inflammatory drugs.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pharmaceutical chemistry and pharmacology, and particularly relates to application of a forskolin oxygen bridge ring derivative in preparation of anti-inflammatory drugs. BACKGROUND

[0002] Inflammation is a series of biological defense reactions produced in order to eliminate harmful stimuli, remove necrotic cells, and repair damaged tissues, such as redness, fever, pain, and dysfunction, which are basic behaviors of the immune system in the process of infection and tissue damage to maintain normal tissue homeostasis. However, long-term chronic inflammation can induce excessive abnormal reactions of the body, and even can induce many diseases such as diabetes, atherosclerosis, Alzheimer's disease, cancer, etc. Inflammation is a complex process at the molecular level, and pro-inflammatory factors are produced by macrophages during inflammation, including tumor necrosis factor (TNF-α), various interleukins, prostaglandins (PG), nitric oxide (NO) and reactive oxygen species (ROS), etc. Studies have shown that asthma, cancer, arthritis and other related chronic degenerative diseases are related to the excessive production of these pro-inflammatory factors. Therefore, it is necessary to find new anti-inflammatory active substances to provide leads for the research and development of new anti-inflammatory drugs. And inhibiting the production of inflammatory factors is an important way to treat inflammatory diseases.

[0003] Forskolin is a diterpenoid compound, which has important medicinal value in anticancer, anti-asthma, antihypertensive and positive inotropic aspects. In addition, forskolin can also interact with other certain proteins, such as acting on glucose transporters and ion channels, etc. The results of pharmacodynamic studies show that forskolin can effectively promote the differentiation of neurons in the central and peripheral nervous system and the growth of neurites, thereby having important effects on the cardiovascular system, respiratory system and tumors, etc., and has pharmacological effects such as cardiotonic, anti-asthma, antitumor, antithrombus and intraocular pressure reduction. Forskolin is now used in the treatment of cardiovascular diseases, tumors and senile diseases, etc. in clinic, has obvious pharmacological effects, and has broad clinical application prospects. However, the anti-inflammatory activity still needs to be further developed. SUMMARY

[0004] Therefore, the purpose of the present application is to provide application of a forskolin oxygen bridge ring derivative with a novel structure in preparation of anti-inflammatory drugs.

[0005] The present application provides a forskolin oxygen bridge ring derivative, which has a structure shown in general formula (I):

[0006]

[0007] wherein R represents one of phenyl, p-chlorophenyl, p-methoxyphenyl, p-trifluoromethoxyphenyl, p-tert-butylphenyl, p-methylphenyl, p-nitrophenyl and p-cyanophenyl.

[0008] Further, the forskolin oxo-bridged derivative has a structure as shown in any one of formulae 2a-2d:

[0009]

[0010] wherein,

[0011] When R is phenyl, the forskolin oxo-bridged derivative is a compound having a structure as shown in formula 2a;

[0012] When R is p-chlorophenyl, the forskolin oxo-bridged derivative is a compound having a structure as shown in formula 2b;

[0013] When R is p-methoxyphenyl, the forskolin oxo-bridged derivative is a compound having a structure as shown in formula 2c;

[0014] When R is p-trifluoromethoxyphenyl, the forskolin oxo-bridged derivative is a compound having a structure as shown in formula 2d.

[0015] The present application also provides a preparation method of the forskolin oxo-bridged derivative, comprising the following steps:

[0016] Forskolin is reacted with potassium hydroxide in methanol to obtain forskolin rearrangement product 1, and then the forskolin rearrangement product 1 is reacted with aryl iodide in anhydrous dichloroethane under catalysis of anhydrous silver acetate, anhydrous copper acetate and palladium acetate to obtain the forskolin oxo-bridged derivative (I).

[0017] The reaction formula of the reaction is as follows:

[0018]

[0019] wherein R represents one of phenyl, p-chlorophenyl, p-methoxyphenyl, p-trifluoromethoxyphenyl, p-tert-butylphenyl, p-methylphenyl, p-nitrophenyl and p-cyanophenyl.

[0020] Specifically, the preparation method comprises the following steps:

[0021] (1) Dissolve potassium hydroxide in methanol, add forskolin, and react at 65℃ for 4h to obtain a first reaction liquid, cool the first reaction liquid, concentrate under reduced pressure, dilute with an organic solvent, sequentially wash with water and saturated brine, dry with anhydrous MgSO4, dry under reduced pressure, and then pass through a flash column to obtain white solid forskolin rearrangement product 1, wherein the molar ratio of forskolin to potassium hydroxide is 1:13;

[0022] (2) The forscoline rearrangement product 1 was dissolved in anhydrous dichloroethane, and anhydrous silver acetate, anhydrous copper acetate, palladium acetate and aryl iodide were added sequentially. The mixture was reacted at 72°C for 18 h to obtain a second reaction solution. The second reaction solution was cooled, diluted with an organic solvent, filtered, and the filtrate was concentrated under reduced pressure. Then, the white solid forscoline oxygen-bridged ring derivative 2 was obtained by flash column chromatography. The molar ratio of forscoline rearrangement product 1, anhydrous silver acetate, anhydrous copper acetate, palladium acetate and aryl iodide was 1:1.2:2:0.05:2.

[0023] The aryl iodide is one of iodobenzene, p-chloroiodobenzene, p-methoxyiodobenzene, p-trifluoromethoxyiodobenzene, p-tert-butyliodobenzene, p-methyliodobenzene, p-nitroiodobenzene, and p-cyanoiodobenzene.

[0024] Furthermore, in the above preparation method, the organic solvent is at least one selected from ethyl acetate, dichloromethane, and dichloroethane.

[0025] Furthermore, the anti-inflammatory drug is a drug that inhibits pro-inflammatory factors.

[0026] Furthermore, the pro-inflammatory factors include one or more of tumor necrosis factor, interleukin, prostaglandin, nitric oxide, and reactive oxygen species.

[0027] Furthermore, the pro-inflammatory factor is nitric oxide.

[0028] Furthermore, the dosage form of the drug is an oral formulation.

[0029] Furthermore, the dosage form of the drug is one of tablets, capsules, pills, granules, decoctions, ointments, elixirs, oral liquids, drop pills, and syrups.

[0030] Furthermore, the drug also includes pharmaceutically acceptable excipients.

[0031] Furthermore, the pharmaceutically acceptable excipients include one or more of the following: fruit powder, flavoring, sweetener, acidulant, filler, lubricant, preservative, suspending agent, food coloring, diluent, emulsifier, disintegrant, and plasticizer.

[0032] Compared with the prior art, this application provides the application of a new type of compound, foscorine oxygen-bridged ring derivatives, in the preparation of anti-inflammatory drugs. This compound contains a unique oxygen-bridged ring structure, and this new structure endows these derivatives with excellent anti-inflammatory activity, which can be applied to the preparation of anti-inflammatory drugs. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0034] Figure 1 Nuclear magnetic resonance of the fuscaline oxygen-bridged ring derivative (1) provided in Example 1 of this invention 1 H spectrum;

[0035] Figure 2 Nuclear magnetic resonance of the fuscaline oxygen-bridged ring derivative (1) provided in Example 1 of this invention 13 C spectrum;

[0036] Figure 3 Nuclear magnetic resonance of the fuscaline oxygen-bridged ring derivative (2a) provided in Example 2 of this invention 1 H spectrum;

[0037] Figure 4 Nuclear magnetic resonance of the fuscaline oxygen-bridged ring derivative (2a) provided in Example 2 of this invention 13 C-spectrum. Detailed Implementation

[0038] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] Example 1

[0040] 730 mg (13.0 mmol) of potassium hydroxide was dissolved in methanol (10 mL), and then 410 mg (1.0 mmol) of forsocolin was added. The reaction mixture was reacted at 65 °C for 4 hours. The reaction solution was concentrated under reduced pressure, diluted with ethyl acetate (10 mL), and then washed successively with water and saturated brine. The solution was dried over anhydrous MgSO4, concentrated under reduced pressure, and obtained by flash column chromatography (petroleum ether:ethyl acetate = 2:1) to give 336 mg of white solid, which was forsocolin rearrangement product 1 (yield 91%).

[0041] 1H NMR(400MHz, Methanol-d4)δ6.06(dd,J=17.5,10.9Hz,1H,H-14),5.16(dd,J=17.5,1.2Hz,1H,H-15),5.04(dd,J=10 .9,1.2Hz,1H,H-15),4.16(dd,J=11.0,5.2Hz,1H,H-1),4.01(dd,J=4.1,1.7Hz,1H,H-6),3.64(d,J=1.6Hz,1H,H-7), 3.19(d,J=14.4Hz,1H,H-12),1.90(d,J=14.3Hz,1H,H-12),1.79–1.68(m,1H),1.65(d,J=4.1Hz,1H,H-5),1.64–1.60 (m,1H),1.52(s,3H,CH3),1.48(s,3H,CH3),1.47(s,3H,CH3),1.34–1.28(m,2H),1.26(s,3H,CH3),0.98(s,3H,CH3). 13 C NMR(100MHz,MeOD)δ143.89,111.35,106.48,91.76,90.54,88.51,88.44,71.18,64 .92,47.66,45.98,44.38,40.55,33.31,30.00,28.38,26.45,24.95,23.14,13.44.

[0042] Example 2

[0043] 368 mg (1.0 mmol) of forsocrine rearrangement product 1 was dissolved in anhydrous dichloroethane (10 mL), followed by the addition of 200 mg (1.2 mmol) of anhydrous silver acetate, 363 mg (2.0 mmol) of anhydrous copper acetate, 12 mg (0.05 mmol) of palladium acetate, and 408 mg (2.0 mmol) of iodobenzene. The reaction mixture was reacted at 72 °C for 18 hours. The reaction solution was diluted with ethyl acetate (10 mL), filtered, and the filtrate was washed successively with water and saturated brine, dried over anhydrous MgSO4, concentrated under reduced pressure, and obtained by flash column chromatography (petroleum ether:ethyl acetate = 8:1) to give 321 mg of a white solid, namely forsocrine oxygen-bridged ring derivative 2a (yield 73%).

[0044] 1H NMR(400MHz,Chloroform-d)δ7.38–7.27(m,4H,ArH),7.26–7.21(m,1H,ArH),6.46(d,J=16.3Hz,1H,H-15),6.38(d,J=16 .3Hz,1H,H-14),5.89(s,1H,OH),4.22(dd,J=10.4,5.7Hz,1H,H-1),4.13(m,2H,H-6,H-7),3.80(d,J=1.6Hz,1H,OH),3.5 8(s,1H,OH),3.27(d,J=14.2Hz,1H,H-12),2.03(d,J=14.1Hz,2H,H-12,OH),1.72(d,J=3.8Hz,1H,H-5),1.71–1.64(m,2H ),1.61(s,3H,CH3),1.59(s,3H,CH3),1.57(s,3H,CH3),1.25(s,3H,CH3),1.11(td,J=13.4,4.9Hz,1H),0.90(s,3H,CH3). 13 C NMR (100MHz, CDCl3) δ136.22,134.87,128.69,127.80,127.71,126.41,106.66,91.67,91.59,88.66,88.46, 71.69,66.46,48.00,47.24,44.73,40.71,33.62,30.89,29.76,27.18,25.60,24.19,14.38.HRMS(ESI):m / z calcd for C 26 H 36 O6Na:467.2410; found:467.2404[M+Na] + .

[0045] Examples 3-5

[0046] According to the method in Example 2 above, iodobenzene was successively replaced with p-chloroiodobenzene, p-methoxyiodobenzene and p-trifluoromethoxyiodobenzene to prepare compounds 2b-2d.

[0047] The following is a list of the physicochemical data for compounds 2b-2d:

[0048] 2b: Yield 70%. 11H NMR (400 MHz, Chloroform-d) δ 7.42–7.21 (m, 4H, ArH), 6.41 (d, J = 16.2 Hz, 1H, H-15), 6.34 (d, J = 16.2 Hz, 1H, H-14), 5.81 (s, 1H, OH), 4.19 (td, J = 6.8, 3.4 Hz, 1H, H-1), 4.12 (d, J = 3.8 Hz, 1H, H-6), 3.90 (s, 1H, OH), 3.79 (d, J = 1.7 Hz, 1H, H-7), 3.33 (s, 1H, OH) 3.23 (d, J = 14.2 Hz, 1H, H-12), 2.01 (d, J = 14.1 Hz, 1H, H-12), 1.91–1.84 (m, 1H), 1.76–1.68 (m, 1H), 1.67 (d, J = 3.8 Hz, 2H, H-5, CH2), 1.59 (s, 4H), 1.58 (s, 3H, CH3), 1.55 (s, 3H, CH3), 1.24 (s, 3H, CH3), 1.05 (td, J = 13.2, 4.8 Hz, 1H), 0.86 (s, 3H, CH3). 13 13C NMR (100 MHz, CDCl3) δ 135.50, 134.7, 133.43, 128.90, 127.58, 126.47, 106.56, 91.70, 91.58, 88.52, 88.44, 71.71, 66.47, 48.02, 47.23, 44.77, 40.77, 33.62, 30.89, 29.78, 27.29, 25.54, 24.16, 14.32. HRMS (ESI): m / z calcd for C 26 1 35 21H11O6NaCl: 501.2020; found: 501.2017 [M+Na] + .

[0049] 2c: Yield 65%. 11H NMR (400 MHz, Chloroform-d) δ 7.28 (d, J = 8.5 Hz, 2H, ArH), 6.86 (d, J = 8.6 Hz, 2H, ArH), 6.42 (d, J = 16.2 Hz, 1H, H-15), 6.26 (d, J = 16.2 Hz, 1H, H-14), 5.88 (s, 1H, OH), 4.24 (td, J = 6.8, 3.3 Hz, 1H, H-1), 4.15 (q, J = 4.0, 3.6 Hz, 1H, H-6), 4.06 (s, 1H, OH), 3.82 (s, 3H, OCH3), 3.82–3.80 (m, 1H, H-7), 3.56 (s, 1H, OH), 3.29 (d, J = 14.2 Hz, 1H, H-12), 2.02 (d, J = 14.2 Hz, 1H, H-12), 2.09–1.97 (m, 1H) 1.75 (d, J = 3.9 Hz, 1H, H-5), 1.73–1.67 (m, 2H), 1.62 (s, 3H, CH3), 1.60 (s, 3H, CH3), 1.58 (s, 3H, CH3), 1.27 (s, 3H, CH3), 1.14 (td, J = 13.2, 4.5 Hz, 1H), 0.92 (s, 3H, CH3). 13 13C NMR (100 MHz, CDCl3) δ 159.29, 132.74, 128.93, 127.59, 127.19, 114.08, 106.65, 91.67, 91.58, 88.74, 88.47, 71.68, 66.49, 55.29, 48.02, 47.29, 44.68, 40.69, 33.63, 30.88, 29.81, 27.20, 25.58, 24.21, 14.34. HRMS (ESI): m / z calcd for C 27 17 38 27O7Na: 497.2515; found: 497.2514 [M+Na] + .

[0050] 2d: Yield 75%. 1H NMR (400MHz, Chloroform-d) δ7.34(d,J=8.7Hz,2H,ArH),7.16(d,J=8.3Hz,2H,ArH),6.46(d,J=16.2Hz,1H,H-15),6.35(d,J=16.3Hz,1H,H -14),5.85(s,1H,OH),4.21(dd,J=10.4,5.8Hz,1H,H-1),4.14(d,J=4.7Hz,1H,H-6),3.99(s,1H,OH),3.81(d,J=1.6Hz,1H,H-7),3.40(s,1 H,OH),3.25(d,J=14.2Hz,1H,H-12),2.03(d,J=14.1Hz,1H,H-12),1.93(d,J=6.5Hz,1H,OH),1.76–1.66(m,2H),1.69(d,J=3.9Hz,1H,H-5) ,1.61(s,3H,CH3),1.59(s,3H,CH3),1.57(s,3H,CH3),1.31–1.28(m,1H),1.26(s,3H,CH3),1.08(td,J=13.4,4.8Hz,1H),0.88(s,3H,CH3). 13 C NMR (100MHz, CDCl3) δ148.73,135.97,135.07,127.71,126.34,121.27,106.69,91.85,91.65,88.59,88.54, 71.80,66.55,48.10,47.34,44.90,40.93,33.72,31.02,29.83,27.36,25.66,24.24,14.44.HRMS(ESI):m / z calcd for C 27 H 35 O7NaF3:551.2233; found:551.2228[M+Na] + .

[0051] To better understand the essence of this invention, the following pharmacological experimental results demonstrating the inhibitory effect of the foscorine oxygen-bridged ring derivative provided by this invention on LPS-induced NO release from RAW264.7 cells illustrate its novel application in the field of anti-inflammatory drug research. The pharmacological examples provide partial activity data for representative compounds. It must be noted that the pharmacological examples of this invention are for illustrative purposes only and not for limiting the invention. Simple modifications to this invention based on its essence are all within the scope of protection claimed by this invention.

[0052] Drug Example 1: Inhibitory activity of compounds 2a-2d, forscorin, and dexamethasone on LPS-induced NO release from RAW264.7 macrophages

[0053] RAW264.7 macrophages were used at a rate of 1×10⁻⁶. 5 RAW264.7 macrophages were seeded at a density of cells / mL in 96-well plates and incubated at 37°C in a 5% CO2 incubator for 24 h. The experiment included a control group, an LPS-induced group, a positive control group treated with dexamethasone (DEX), and experimental groups. The positive control and experimental groups were treated with 0.2, 1.0, 5.0, and 25.0 μM of the test compound 2a-2d or DEX, respectively. After 4 h of incubation, 10 μL of culture medium was added to the control group, while LPS (1.0 μg / mL) was added to the other groups to induce cell growth. After 24 h of incubation, the cells were centrifuged, and the supernatant was collected. The NO release was determined using a nitric oxide kit, and the IC50 was calculated using Graphpad 5 software. 50 The effect of the compound at 20 μM on the growth of RAW264.7 macrophages was detected using the MTT assay.

[0054] Table 1. Inhibitory activity of compounds 2a-2d, foscorine, and dexamethasone on LPS-induced NO release from RAW264.7 macrophages.

[0055]

[0056]

[0057] As shown in Table 1, the forsocrine oxygen-bridged ring derivative provided by this invention has important biological activities. The inhibitory activity test of LPS-induced NO release from RAW264.7 macrophages showed that the forsocrine oxygen-bridged ring derivative with the structure shown in formula (1) has good inhibitory activity on LPS-induced NO release from RAW264.7 macrophages. In the examples, the inhibitory effect of compounds 2a-2d is comparable to that of the positive control drug dexamethasone and is significantly better than that of the positive control drug forsocrine. Moreover, it has no obvious cytotoxicity and may be developed into a new anti-inflammatory drug.

[0058] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. The use of forscolin oxygen-bridged ring derivatives in the preparation of anti-inflammatory drugs, wherein the forscolin oxygen-bridged ring derivatives are compounds of the following formula or pharmaceutically acceptable salts thereof; in, R represents one of the following: phenyl, p-chlorophenyl, p-methoxyphenyl, p-trifluoromethoxyphenyl, p-tert-butylphenyl, p-methylphenyl, p-nitrophenyl, and p-cyanophenyl.

2. The application according to claim 1, characterized in that, The fuscaline oxygen-bridged ring derivative has a structure as shown in any one of formulas 2a to 2d:

3. The application according to claim 1, characterized in that, The anti-inflammatory drug is a drug that inhibits pro-inflammatory factors.

4. The application according to claim 3, characterized in that, The pro-inflammatory factors include one or more of tumor necrosis factor, interleukin, prostaglandin, nitric oxide, and reactive oxygen species.

5. The application according to claim 3, characterized in that, The pro-inflammatory factor is nitric oxide.

6. The application as described in any one of claims 1-5, characterized in that, The drug is an oral formulation.

7. The application as described in any one of claims 1-5, characterized in that, The dosage form of the drug is one of the following: tablets, capsules, pills, granules, decoctions, ointments, elixirs, oral liquids, drop pills, and syrups.

8. The application as described in any one of claims 1-5, characterized in that, The drug also includes pharmaceutically acceptable excipients.

9. The application as described in claim 8, characterized in that, The pharmaceutically acceptable excipients include one or more of the following: fruit powder, flavoring, sweetener, acidulant, filler, lubricant, preservative, suspending agent, food coloring, emulsifier, disintegrant, and plasticizer.

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