Truncated pleuromutilin derivatives with furan side chains, methods for their preparation and use

Abstract

The present application belongs to the technical field of antibacterial drugs, and provides a pleuromutilin derivative with furan side chain, a preparation method and application thereof. Specifically, it relates to a pleuromutilin derivative with furan side chain shown in general formula (I), a pharmaceutical composition containing the derivative, and application of the derivative in preparation of drugs for preventing and treating human and / or animal bacterial infectious diseases, especially for preventing and treating infections of gram-positive bacteria such as staphylococcus aureus, drug-resistant staphylococcus aureus and intermediate staphylococcus. The pleuromutilin derivative with furan side chain has a structure general formula (I).

Description

Technical Field

[0001] This invention belongs to the field of antibacterial drug technology, specifically relating to truncated pleurotin derivatives with furan side chains, their preparation methods, and applications. Background Technology

[0002] Gram-positive bacteria, capable of producing exotoxins that cause disease in humans, mainly include Staphylococcus aureus, Staphylococcus intermedius, and Streptococcus. Staphylococcus aureus is a representative Gram-positive bacterium and a typical zoonotic pathogen, widely distributed in nature. With the long-term and extensive use of antibiotics in both humans and animals, the problem of drug resistance in Staphylococcus aureus has become increasingly serious, especially the issue of drug resistance transmission from animals to humans, which requires high attention. Pleurotin is a naturally occurring tricyclic diterpenoid compound derived from fungi, possessing a highly rigid 5-6-8 tricyclic carbon skeleton with eight stereocenters. This skeleton differs from commonly used antibacterial nuclei in clinical practice, making it less prone to cross-resistance with other structural antibacterial drugs and thus an excellent nucleus for antibacterial drugs.

[0003] Currently, four truncated pleurotin antibiotics have been approved, and several others are in clinical trials, such as tiamulin and voremurine for poultry, as well as retamorin for local human infections and lefamorin for systemic human treatment. To address the problem of local Staphylococcus aureus or Staphylococcus intermedius infections of animal skin and to more effectively prevent and treat Gram-positive bacterial infections in humans and / or animals, there is an urgent need to develop novel truncated pleurotin antibiotics for veterinary use. Summary of the Invention

[0004] The present invention aims to solve the technical problems existing in the prior art and provide a truncated pleurotin derivative with furan side chain, its preparation method and application.

[0005] The technical solution of this invention is as follows:

[0006] In a first aspect, the present invention provides a truncated pleurotin derivative having a furan side chain, the general structural formula of which is shown in formula (I):

[0007]

[0008] Where R is selected from Preferably, the truncated pleurotin derivative having a furan side chain is selected from structures 1-7 in the table below:

[0009]

[0010] The derivatives of pleuromutilins having furan side chains according to the present application of general formula (I) can also exist in the form of their salts, which are converted in vivo into the derivatives of general formula (I). For example, within the scope of the present application, the derivatives of the present application can be converted into the form of pharmaceutically acceptable salts according to the processes known in the art and used in the form of salts.

[0011] All tautomeric forms of the derivatives of general formula (I) according to the present application are included within the scope of the present application. The compounds of the present application can exist in specific geometric or stereoisomeric forms. The structure contains 8 chiral centers and all these isomers as well as their mixtures are included within the scope of the present application.

[0012] The pharmaceutically acceptable salts include, but are not limited to, the salts of the derivatives of general formula (I) with hydrochloric acid, sulfuric acid, phosphoric acid, hydrobromic acid, acetic acid, trifluoroacetic acid, pyruvic acid, citric acid, tartaric acid, lactic acid, maleic acid, benzenesulfonic acid, succinic acid, methanesulfonic acid, p-toluenesulfonic acid, fumaric acid, salicylic acid or phenylacetic acid.

[0013] The second aspect of the present application also provides a synthetic route of the derivatives of pleuromutilins having furan side chains of general formula (I):

[0014]

[0015] The derivatives of general formula (I) according to the present application can be obtained by the above-mentioned or similar preparation methods according to the different substituents and the different positions of the substituents by using the corresponding starting materials. Step 1 of the synthetic route is the reaction of the starting materials in a certain molar ratio to obtain the product by substitution reaction, and the pure product is obtained without purification or column chromatography; Step 2 is to obtain the target compound by condensation reaction, and the pure product is obtained by column chromatography purification.

[0016] The skilled person will appreciate that the above routes are useful to understand the present application but are not limited to the content of the present application, and unless otherwise specified, the variables are defined as mentioned in general formula (I).

[0017] The third aspect of the present application provides a pharmaceutical composition comprising the derivatives of pleuromutilins having furan side chains of general formula (I) and one or more pharmaceutically acceptable carriers and / or excipients.

[0018] The pharmaceutical composition of the present application can be administered in various known ways, for example, orally, parenterally, by spray administration. The pharmaceutical composition of the present application can be administered alone or in combination with other drugs. The oral composition can be in any orally acceptable dosage form, including but not limited to tablets, capsules, emulsions, and suspensions, dispersions and solutions. Commonly used pharmaceutically acceptable carriers or excipients include stabilizers, diluents, surfactants, lubricants, antioxidants, binders, colorants, fillers, emulsifiers, etc.

[0019] Sterile injection compositions can be formulated according to techniques known in the art using suitable dispersing agents or wetting agents and suspending agents. Pharmaceutically acceptable carriers and solvents can be used, including water, mannitol, sodium chloride solution, etc.

[0020] In a fourth aspect of the present application, there are provided the pleuromutilin derivatives with furan side chain represented by general formula (I) and crystal forms, hydrates, solvates, prodrugs, racemates, metabolites thereof.

[0021] In a fifth aspect of the present application, there is provided the use of the pleuromutilin derivatives with furan side chain represented by general formula (I) or the pharmaceutical composition in the preparation of a medicament for preventing and treating infectious diseases.

[0022] Preferably, the infectious diseases are for preventing and treating Gram-positive bacteria such as Staphylococcus aureus and drug-resistant Staphylococcus aureus, Staphylococcus intermedius, etc. in target animals such as ruminants, livestock, dogs, cats, etc.

[0023] Advantages:

[0024] The pleuromutilin derivatives with furan side chain reported in the present application are a class of novel compounds with strong activities against Staphylococcus aureus, drug-resistant Staphylococcus aureus, Staphylococcus intermedius, etc. and are expected to be developed into novel antibacterial drugs for preventing and treating bacterial infectious diseases in humans and / or animals, with a broad clinical application prospect. DETAILED DESCRIPTION

[0025] The preparation methods of the derivatives of general formula (I) of the present application will be described below in combination with specific examples, but these specific methods do not constitute any limitation on the present application. The compounds of the present application can also be conveniently prepared by optionally combining various synthetic methods described in the present specification or known in the art, which can be easily performed by those skilled in the art to which the present application belongs.

[0026] The starting materials, reaction reagents, etc. used in the specific examples of the present application are all conventional reagents in the technical field, which are commercially available. The salted forms of the present application can be prepared by using the commonly used salt formation methods in the art.

[0027] The experimental methods not specified in the embodiments of the present application are generally carried out according to the conventional conditions, or according to the conditions suggested by the manufacturers of raw materials or commodities.

[0028] The structures of all compounds in the embodiments are characterized by waters QDa mass spectrometry and nuclear magnetic resonance hydrogen spectrum (H-NMR). 1 H-NMR) characterization.

[0029] Example 1

[0030] Preparation of compound 1

[0031]

[0032] Step 1:

[0033] 2.8 g of starting material 2 was dissolved in 20 mL of water, 2.6 g of starting material 1 was added dropwise at room temperature, and the reaction was continued to stir for 1 h after the dropwise addition was completed. The ice bath was cooled, the pH was adjusted to 1 with 1M dilute hydrochloric acid, 10 mL of ethyl acetate was extracted for 3 times, the combined organic phase was washed with saturated brine once, and anhydrous sodium sulfate was dried to obtain an intermediate 3 solution, which was directly used for the next step without rotary evaporation. + : 143.1.

[0034] Step 2:

[0035] 2.8 g of p-toluenesulfonyl chloride and 3.8 g of pleuromutilin were dissolved in 20 mL of methyl tert-butyl ether, 10 mL of 10M sodium hydroxide was added under ice bath, and the temperature was increased to 60°C for 1 h. The temperature was decreased to room temperature, the intermediate 3 solution was added, and the reaction was continued to reflux for 1 h. The temperature was decreased to room temperature, and the filter cake was washed with water. After drying, the filter cake was column chromatographed to obtain the pure product, i.e. compound 1. [M+H] + : 503.2, 1 H-NMR (DMSO-d6, 300 MHz) δ: 7.45 (d, 1H), 6.78 (d, 1H), 6.17 (t, 1H), 5.55 (d, 1H), 5.08 (dd, 2H), 4.55 (d, 1H), 3.87 (s, 2H), 3.43 (t, 1H), 2.42 (s, 1H), 2.37 (s, 3H), 2.21 (dd, 1H), 2.05 (m, 3H), 1.68 (t, 2H), 1.48 (t, 1H), 1.37 (m, 4H), 1.32 (d, 1H), 1.24 (m, 2H), 1.06 (s, 3H), 0.98 (d, 1H), 0.83 (d, 3H), 0.65 (d, 3H).

[0036] Example 2

[0037] Preparation of compound 2

[0038]

[0039] Step 1:

[0040] Dissolve 4.1 g of starting material 2 in 20 mL of water, add 2.6 g of starting material 1 dropwise at room temperature, continue stirring for 1 h after the addition is completed, cool in an ice bath, adjust pH to 1 with 1 M dilute hydrochloric acid, extract with 10 mL x 3 of ethyl acetate, wash the combined organic phase with saturated brine once, dry over anhydrous sodium sulfate, and obtain a solution of intermediate 3, which is directly used in the next step without rotary evaporation. + : 205.1.

[0041] Step 2:

[0042] Dissolve 2.8 g of p-toluenesulfonyl chloride and 3.8 g of pleuromutilin in 20 mL of methyl tert-butyl ether, add 10 mL of 10 M sodium hydroxide under ice bath, warm to 60 °C and react for 1 h, cool to room temperature, add the solution of intermediate 3, continue to warm to reflux and react for 1 h, cool to room temperature, filter, and wash the filter cake with water. After drying, column chromatography of the filter cake gives pure compound 2. [M+H] + : 565.2, 1 H-NMR (DMSO-d6, 300 MHz) δ: 8.06 (d, 2H), 7.61 (t, 1H), 7.56 (m, 2H), 7.45 (d, 1H), 6.78 (d, 1H), 6.17 (d, 1H), 5.55 (d, 1H), 5.08 (dd, 2H), 4.55 (d, 1H), 3.87 (s, 2H), 3.43 (t, 1H), 2.42 (s, 1H), 2.21 (dd, 1H), 2.05 (m, 3H), 1.68 (t, 2H), 1.48 (t, 1H), 1.37 (m, 4H), 1.32 (d, 1H), 1.24 (m, 2H), 1.06 (s, 3H), 0.98 (d, 1H), 0.83 (d, 3H), 0.65 (d, 3H).

[0043] Example 3

[0044] Preparation of compound 3

[0045]

[0046] Step 1:

[0047] Dissolve 4.1 g of starting material 2 in 20 mL of water, add 2.6 g of starting material 1 dropwise at room temperature, continue stirring for 1 h after the addition is completed, cool in an ice bath, adjust pH to 1 with 1 M dilute hydrochloric acid, extract with 10 mL x 3 of ethyl acetate, wash the combined organic phase with saturated brine once, dry over anhydrous sodium sulfate, and obtain a solution of intermediate 3, which is directly used in the next step without rotary evaporation. [M+H]+ :172.2.

[0048] Step 2:

[0049] Dissolve p-toluenesulfonyl chloride 2.8 g and pleuromutilin 3.8 g in methyl tert-butyl ether 20 mL, add 10 M sodium hydroxide 10 mL under ice bath, warm up to 60 °C for 1 h, cool down to room temperature, add the solution of intermediate 3, continue to warm up to reflux for 1 h, cool down to room temperature, filter, wash the filter cake with water. Dry the filter cake, then column chromatography to get the pure product, which is compound 3. [M+H] + :532.2, 1 H-NMR (DMSO-d6, 300 MHz) δ: 7.45 (d, 1H), 7.29 (d, 1H), 6.17 (t, 1H), 5.55 (d, 1H), 5.08 (dd, 2H), 4.55 (d, 1H), 3.87 (s, 2H), 3.43 (t, 1H), 3.03 (s, 6H), 2.42 (s, 1H), 2.21 (dd, 1H), 2.05 (m, 3H), 1.68 (t, 2H), 1.48 (t, 1H), 1.37 (m, 4H), 1.32 (d, 1H), 1.24 (m, 2H), 1.06 (s, 3H), 0.98 (d, 1H), 0.83 (d, 3H), 0.65 (d, 3H).

[0050] Example 4

[0051] Preparation of compound 4

[0052]

[0053] Step 1:

[0054] Dissolve 4.3 g of starting material 2 in water 20 mL, add 2.6 g of starting material 1 dropwise at room temperature, continue to stir for 1 h after the addition is completed, cool down in ice bath, adjust pH = 1 with 1 M dilute hydrochloric acid, extract with ethyl acetate 10 mL x 3, wash the combined organic phase with saturated brine once, dry over anhydrous sodium sulfate to get intermediate 3, which is directly used in the next step without rotary evaporation. [M+H] + :213.2.

[0055] Step 2:

[0056] Dissolve p-toluenesulfonyl chloride 2.8 g and pleuromutilin 3.8 g in methyl tert-butyl ether 20 mL, add 10 M sodium hydroxide 10 mL under ice bath, warm up to 60 °C for 1 h, cool down to room temperature, add the solution of intermediate 3, continue to warm up to reflux for 1 h, cool down to room temperature, filter, wash the filter cake with water. Dry the filter cake, then column chromatography to get the pure product, which is compound 4. [M+H] + :573.2,1 H-NMR (DMSO-d6, 300 MHz) δ: 7.41 (d, 1H), 6.72 (d, 1H), 6.17 (t, 1H), 5.55 (d, 1H), 5.11 (t, 1H), 5.08 (dd, 2H), 4.55 (d, 1H), 3.87 (s, 2H), 3.67 (t, 2H), 3.43 (t, 1H), 2.42 (s, 1H), 2.21 (dd, 1H), 2.05 (m, 3H), 1.98 (t, 1H), 1.76 (m, 3H), 1.68 (t, 2H), 1.55 (m, 2H), 1.48 (t, 1H), 1.37 (m, 4H), 1.32 (d, 1H), 1.24 (m, 2H), 1.06 (s, 3H), 0.98 (d, 1H), 0.83 (d, 3H), 0.65 (d, 3H).

[0057] Example 5

[0058] Preparation of compound 5

[0059]

[0060] Step 1:

[0061] Dissolve 4.2 g of starting material 2 in 20 mL of water, add 2.6 g of starting material 1 dropwise at room temperature, continue stirring for 1 h after the addition is complete, cool in an ice bath, adjust pH to 1 with 1 M dilute hydrochloric acid, extract with 10 mL x 3 of ethyl acetate, wash the combined organic phase with saturated brine once, dry over anhydrous sodium sulfate, and obtain a solution of intermediate 3 without rotary evaporation, which is directly used for the next step. + : 212.2.

[0062] Step 2:

[0063] Dissolve 2.8 g of p-toluenesulfonyl chloride and 3.8 g of pleuromutilin in 20 mL of methyl tert-butyl ether, add 10 mL of 10 M sodium hydroxide under ice bath, warm to 60 °C for 1 h, cool to room temperature, add the solution of intermediate 3, continue to warm to reflux for 1 h, cool to room temperature, filter, and wash the filter cake with water. Dry the filter cake and column chromatograph to obtain the pure product, i.e. compound 5. [M+H] + : 572.2, 1H-NMR (DMSO-d6, 300 MHz) δ: 7.45 (d, 1H), 7.28 (d, 1H), 6.17 (t, 1H), 5.55 (d, 1H), 5.08 (dd, 2H), 4.55 (d, 1H), 3.87 (s, 2H), 3.43 (t, 1H), 3.36 (t, 4H), 2.42 (s, 1H), 2.21 (dd, 1H), 2.05 (m, 3H), 1.68 (t, 2H), 1.61 (m, 1H), 1.56 (m, 4H), 1.48 (t, 1H), 1.37 (m, 4H), 1.32 (d, 1H), 1.24 (m, 2H), 1.06 (s, 3H), 0.98 (d, 1H), 0.83 (d, 3H), 0.65 (d, 3H).

[0064] Example 6

[0065] Preparation of compound 6

[0066]

[0067] Step 1:

[0068] Dissolve 4.0 g of starting material 2 in 20 mL of water, add 2.6 g of starting material 1 dropwise at room temperature, continue stirring for 1 h after the addition is completed, cool in an ice bath, adjust pH to 1 with 1 M dilute hydrochloric acid, extract with 10 mL x 3 of ethyl acetate, wash the combined organic phase with saturated brine once, dry over anhydrous sodium sulfate, and obtain a solution of intermediate 3 without rotary evaporation, which is directly used in the next step. + : 198.2.

[0069] Step 2:

[0070] Dissolve 2.8 g of p-toluenesulfonyl chloride and 3.8 g of pleuromutilin in 20 mL of methyl tert-butyl ether, add 10 mL of 10 M sodium hydroxide under ice bath, warm to 60 °C for 1 h, cool to room temperature, add the solution of intermediate 3, continue to warm to reflux for 1 h, cool to room temperature, filter, and wash the filter cake with water. Dry the filter cake and column chromatograph to obtain the pure product, compound 6. [M+H] + : 558.2, 1H-NMR (DMSO-d6, 300 MHz) δ: 7.45 (d, 1H), 7.29 (d, 1H), 6.17 (t, 1H), 5.55 (d, 1H), 5.08 (dd, 2H), 4.55 (d, 1H), 3.87 (s, 2H), 3.43 (t, 1H), 3.09 (t, 4H), 2.42 (s, 1H), 2.21 (dd, 1H), 2.05 (m, 3H), 1.93 (t, 4H), 1.68 (t, 2H), 1.48 (t, 1H), 1.37 (m, 4H), 1.32 (d, 1H), 1.24 (m, 2H), 1.06 (s, 3H), 0.98 (d, 1H), 0.83 (d, 3H), 0.65 (d, 3H).

[0071] Example 7

[0072] Preparation of compound 7

[0073]

[0074] Step 1:

[0075] Dissolve 3.1 g of starting material 2 in 20 mL of water, add 2.6 g of starting material 1 dropwise at room temperature, continue stirring for 1 h after the addition is complete, cool in an ice bath, adjust pH to 1 with 1 M dilute hydrochloric acid, extract with 10 mL x 3 of ethyl acetate, wash the combined organic phase with saturated brine once, dry over anhydrous sodium sulfate, and use directly without rotary evaporation for the next step. [M+H] + : 153.9.

[0076] Step 2:

[0077] Dissolve 2.8 g of p-toluenesulfonyl chloride and 3.8 g of pleuromutilin in 20 mL of methyl tert-butyl ether, add 10 mL of 10 M sodium hydroxide under ice bath, warm to 60 °C for 1 h, cool to room temperature, add a solution of intermediate 3, continue to warm to reflux for 1 h, cool to room temperature, filter, and wash the filter cake with water. Dry the filter cake and column chromatograph to obtain the pure product, compound 7. [M+H] + : 514.2, 1H-NMR (DMSO-d6, 300 MHz) δ: 7.65 (d, 1H), 7.34 (d, 1H), 6.17 (t, 1H), 5.55 (d, 1H), 5.08 (dd, 2H), 4.55 (d, 1H), 3.87 (s, 2H), 3.43 (t, 1H), 2.42 (s, 1H), 2.21 (dd, 1H), 2.05 (m, 3H), 1.68 (t, 2H), 1.48 (t, 1H), 1.37 (m, 4H), 1.32 (d, 1H), 1.24 (m, 2H), 1.06 (s, 3H), 0.98 (d, 1H), 0.83 (d, 3H), 0.65 (d, 3H).

[0078] Example 8 Study on in vitro antibacterial activity

[0079] The truncated pleuromutilin derivatives obtained in the above Examples 1-7 were determined for minimum inhibitory concentration on standard Staphylococcus aureus (ATCC 29213), clinically drug-resistant Staphylococcus aureus (ATCC 43300) and intermediate Staphylococcus (ATCC 29663) by broth dilution method, with tylosin as positive control drug. The concentration of each test hole broth was about 1 x 10 6 CFU·mL, and the drug concentration was 16, 8, 4, 2, 1, 0.5, 0.25, 0.125, 0.06, 0.03, respectively. After inoculation, the 96-well plate was placed in a 37℃ incubator for culture, and the broth growth was observed after 24h. The results are shown in Table 1:

[0080] Table 1 In vitro minimum inhibitory concentration (μg / mL) of truncated pleuromutilin derivatives

[0081]

[0082] Conclusion: The antibacterial activity of the truncated pleuromutilin derivatives prepared in the present application on standard Staphylococcus aureus (ATCC 29213), clinically drug-resistant Staphylococcus aureus (ATCC 43300) and intermediate Staphylococcus (ATCC 29663) in vitro is better than that of the control drug tylosin, which has broad clinical application prospects and great development value.

Claims

1. A truncated pleurotin derivative of general formula (I) having a furan side chain: (I); R is selected from , , , , , , .

2. A pharmaceutical composition, characterized in that, It includes the truncated pleurotin derivative with furan side chains as described in claim 1, and one or more pharmaceutically acceptable carriers and / or excipients.

3. The use of the truncated pleurotin derivative with furan side chains as described in claim 1 or the pharmaceutical composition as described in claim 2 in the preparation of a medicament for preventing and treating infectious diseases caused by Staphylococcus aureus and Staphylococcus intermedius.

4. The application according to claim 3, characterized in that, The Staphylococcus aureus mentioned is a drug-resistant Staphylococcus aureus.

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