Use of a side chain nitrogen-containing heterocycle or alkylamine-containing pleuromutilin derivative in the preparation of a medicament for preventing and treating mycoplasma gallisepticum

Abstract

The application belongs to the field of pharmaceutical chemistry, and discloses a use of a side chain nitrogen-containing heterocycle or alkylamine pleuromutilin derivative in preparation of a drug for preventing and treating mycoplasma gallisepticum. The side chain nitrogen-containing heterocycle or alkylamine pleuromutilin derivative is a compound shown in a structure of formula 2 or a pharmaceutically acceptable salt thereof. The side chain nitrogen-containing heterocycle or alkylamine pleuromutilin derivative has good anti-mycoplasma activity, is suitable for being used as a new type of anti-mycoplasma drug for mycoplasma infection of chickens, and has good water solubility.

Description

Technical Field

[0001] This invention belongs to the field of medicinal chemistry, and in particular relates to the use of a truncated pleurotin derivative with a nitrogen-containing heterocyclic or alkylamine side chain in the preparation of drugs for the prevention and treatment of Mycoplasma gallisepticum. Background Technology

[0002] Mycoplasma, discovered by Nocard et al. in 1898, is a prokaryotic organism lacking a cell wall; the only visible organelle in its cells is the ribosome. Mycoplasma can pass through bacterial filters and exhibits heat resistance similar to bacteria. Among human pathogenic mycoplasma, *Mycoplasma pneumoniae* causes pneumonia, while *Mycoplasma hominis*, *Ureaplasma urealyticum*, and *Mycoplasma genitalium* primarily cause urogenital tract infections. In veterinary clinics, pathogenic mycoplasma commonly causes respiratory infections in livestock and poultry.

[0003] Mycoplasma infection in chickens, also known as mycoplasma contact disease, is caused by Mycoplasma gallisepticum (MG) and Mycoplasma synoviae (MS). MG infection can cause chronic respiratory disease in chickens, with clinical symptoms including cough, runny nose, and tracheal rales. MS infection can cause synoviae inflammation, characterized by swollen hock joints, lameness in the thigh, poor growth in chicks, and decreased egg production in laying hens. Currently, almost all poultry farms have mycoplasma infections, making this disease an invisible profit killer. The occurrence of mycoplasma infection in chicken farms seriously harms the profitability of the poultry industry and causes numerous problems; for example, it significantly reduces the utilization rate of breeding chickens, the egg production rate of laying hens, and the profits of commercial chickens, severely damaging the immune system and exacerbating secondary infections. Therefore, the development of new drugs for the prevention and treatment of Mycoplasma gallisepticum is particularly urgent.

[0004] Paraplegic pleurotin ( Pleuromutilin Formula 1) is a natural tricyclic diterpenoid compound derived from Pleurotus ostreatus. Pleurotus mutilatus and Pleurotus Passeckerianus It is produced by cultivation and has a structure with a rigid 5-6-8 tricyclic carbon skeleton with eight stereocenters and a C(14) glycolic acid chain.

[0005] Mode Studies have shown that truncated pleurotins and their derivatives exhibit effective antibacterial activity against Gram-positive bacteria. Unlike other widely used clinical antibacterial drugs, truncated pleurotins and their derivatives inhibit bacterial protein synthesis by binding to the V region of the peptidyl transferase center (PTC) of the 23S RNA of the bacterial 50S ribosomal subunit. Due to their unique mechanism of action, truncated pleurotins and their derivatives exhibit a low incidence of cross-resistance with other antibacterial agents and a low tendency for bacterial resistance to develop. Furthermore, they do not interact significantly with mammalian cell ribosomes or interfere with protein synthesis in eukaryotic cells. Notably, the C14 side chain in the truncated pleurotin molecule can penetrate deep into the hydrophobic group of the ribosomal subunit, enhancing its antibacterial activity. Therefore, chemically modifying the C14 side chain has been an important method for improving the drug-likeness of truncated pleurotin derivatives.

[0006] To date, by modifying its C14 side chain, the veterinary antibiotic tiamulin has been successfully marketed. Tiamulin ), Woni Miaolin ( Valnemulin ), human skin topical medicine Retamiflu ( Retapamulin ) and Lefulumorin, a human drug approved by the US FDA in 2019 for the treatment of community-acquired bacterial pneumonia (CABP). Lefamulin There are four drugs in total. Compared with drugs developed based on the same parent nucleus, such as penicillin, cephalosporins, and quinolone antibiotics, which often number in the dozens, only four antibiotics based on truncated pleurotin have been successfully developed, and resistant bacteria to truncated pleurotin antibiotics are still relatively rare.

[0007] Antibacterial drugs are one of the main means of preventing and treating mycoplasma infections. However, there is a lack of truncated pleurotin derivatives for the treatment of mycoplasma diseases. Therefore, it is necessary and promising to develop truncated pleurotin derivatives with nitrogen-containing heterocyclic or alkylamine side chains as anti-mycoplasma drugs.

[0008] No reports have been found regarding the anti-mycoplasma effects of truncated pleurotin derivatives with nitrogen-containing heterocyclic or alkylamine side chains, nor have any related patents been published. Summary of the Invention

[0009] In order to overcome the shortcomings and disadvantages of the existing technology, the purpose of this invention is to provide the use of a truncated pleurotin derivative with a nitrogen-containing heterocyclic or alkylamine side chain in the preparation of a drug for the prevention and treatment of Mycoplasma gallisepticum.

[0010] The objective of this invention is achieved through the following technical solution: Use of a truncated pleurotin derivative with a nitrogen-containing heterocyclic or alkylamine side chain in the preparation of a drug for the prevention and treatment of Mycoplasma gallisepticum, wherein the truncated pleurotin derivative with a nitrogen-containing heterocyclic or alkylamine side chain is a compound with the structure shown in Formula 2 or a pharmaceutically acceptable salt thereof: Formula 2 Where R is , , , , , , , ; R1 is methyl and R2 is methyl; or R1 is methyl and R2 is propyl; or R1 is methyl and R2 is isopropyl; or R1 is methyl and R2 is hydroxyethyl; or R1 is methyl and R2 is propenyl. R3 is a hydrogen atom, R4 is a formaldehyde group, R5 is a hydrogen atom, and R6 is a hydrogen atom; or R3 is a hydrogen atom, R4 is an acetonitrile group, R5 is a hydrogen atom, and R6 is a hydrogen atom; or R3 is a methyl group, R4 is a methyl group, R5 is a hydrogen atom, and R6 is a hydrogen atom; or R3 is a formaldehyde group, R4 is a methyl group, R5 is a methyl group, and R6 is a hydrogen atom. R7 is a methyl group, R8 is a hydrogen atom, and R9 is a hydrogen atom; or R7 is a hydrogen atom, R8 is a hydrogen atom, and R9 is a nitrile group; or R7 is a hydrogen atom, R8 is a methyl group, and R9 is a hydrogen atom; or R7 is a hydrogen atom, R8 is a hydrogen atom, and R9 is a hydrogen atom; or R7 is a hydrogen atom, R8 is a formaldehyde group, and R9 is a hydrogen atom. The R 10 It is methyl, pyridine, or hydroxyethyl; The R 11 For carbon atoms, R 12 It is a nitrogen atom; The specific functional groups of the compounds with the above preferred structures are summarized in Tables 1, 2, 3, and 4: Table 1. Compounds 2, 13, 14, 17, 18 and their specific functional groups Table 2. Compounds 12, 15, 16, and 20 and their specific functional groups. Table 3. Compounds 4, 6, 7, 9, and 21 and their specific functional groups. Table 4. Compounds 3, 8, 10, and 11 and their specific functional groups. The pharmaceutically acceptable salt is a salt formed by a compound with the structure shown in Formula 2 and hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid, acetic acid, fumaric acid, maleic acid, oxalic acid, malonic acid, succinic acid, citric acid, malic acid, methanesulfonic acid, ethanesulfonic acid, benzenesulfonic acid, toluenesulfonic acid, glutamic acid, or aspartic acid.

[0011] The pharmaceutically acceptable salt has the following structural formula: .

[0012] The truncated pleurotin derivative with nitrogen-containing heterocyclic or alkylamine side chains was prepared according to the following method: (1) The truncated pleurotin was reacted with p-toluenesulfonyl chloride to obtain intermediate I with the structure shown in Formula 3; (2) Using 2-aminophenylthiol as a raw material, react with intermediate I to obtain intermediate II with the structure shown in Formula 4; (3) The intermediate II obtained in step (2) is reacted with chloroacetyl chloride to obtain intermediate III with the structure shown in Formula 5; (4) The intermediate III obtained in step (3) is reacted with various secondary amines to obtain truncated pleurotin derivatives with nitrogen-containing heterocyclic or alkylamine side chains. .

[0013] The preferred molar ratio of p-toluenesulfonyl chloride to pleurotin in step (1) is 1.1:1; The reaction described in step (2) specifically involves dissolving sodium hydroxide in pure water to obtain a sodium hydroxide solution, with the preferred molar ratio of sodium hydroxide to intermediate I being 5:1; dissolving intermediate I and 2-aminobenzylthiol in ethyl acetate to obtain a reaction solution; the preferred molar ratio of intermediate I to 2-aminobenzylthiol being 1:1.1; and adding the sodium hydroxide solution dropwise to the reaction solution under ice bath conditions, with the preferred reaction conditions being 70°C for 2 hours.

[0014] The reaction described in step (3) specifically uses toluene as a solvent, the molar ratio of intermediate II to chloroacetyl chloride is preferably 1:1.1, and the reaction conditions are preferably room temperature reaction for 2-3 hours.

[0015] The reaction described in step (4) involves first dissolving intermediate III in acetonitrile as a solvent, then adding alkali, and heating at 70°C under reflux for 1-3 hours to obtain a reaction solution. The amount of acetonitrile used is 30-40 times the mass of intermediate III, and the molar ratio of alkali to intermediate III is preferably 3:1. The resulting reaction solution is then heated under reflux with a secondary amine at 70-78°C for 1-3 hours.

[0016] The preferred alkali is sodium hydroxide, potassium hydroxide, cesium hydroxide, sodium carbonate, potassium carbonate, or cesium carbonate. The synthetic route for the truncated pleurotin derivatives with nitrogen-containing heterocyclic or alkylamine side chains is shown in the following formula: Compared with the prior art, the present invention has the following advantages and beneficial effects: (1) The application of the truncated pleurotin derivative provided by the present invention in the treatment of mycoplasma is unprecedented.

[0017] (2) Through extensive and in-depth research, this invention has summarized a large number of truncated pleurotin derivatives with nitrogen-containing heterocyclic or alkylamine side chains and conducted extensive screening for anti-mycoplasma activity. For the first time, it was discovered that this type of compound has good in vitro anti-Mycoplasma gallisepticum activity, and is therefore particularly suitable as a new anti-mycoplasma drug for the prevention and treatment of mycoplasma infections in animals, especially infections caused by Mycoplasma gallisepticum.

[0018] (3) The truncated pleurotin derivatives with nitrogen-containing heterocyclic or alkylamine side chains proposed in this invention have good bio-water solubility and are more advantageous in the preparation of drugs for the prevention and treatment of Mycoplasma gallisepticum. Detailed Implementation

[0019] The present invention will be further described in detail below with reference to embodiments, but the implementation of the present invention is not limited thereto.

[0020] The specific functional groups in the examples are shown in Table 1, all of which are commercially available. Other reagents are also commercially available.

[0021] Example 1 Preparation of intermediate I: 10.0 g (26.5 mmol) of truncated pleurotin was dissolved in 20 ml of pyridine to obtain a truncated pleurotin pyridine solution, which was then placed in an ice bath. 5.6 g (29.2 mmol) of p-toluenesulfonyl chloride was dissolved in 10 ml of pyridine, and then the above truncated pleurotin pyridine solution was slowly added. The mixture was stirred in an ice bath for 3 h, and then 50 ml each of ice water and chloroform were added sequentially. The mixture was then transferred to a separatory funnel and shaken, and allowed to stand until it separated into layers. The organic phase was taken and washed sequentially with 100 ml of 4 mol / L sulfuric acid, 100 ml of saturated sodium bicarbonate solution, and 100 ml of deionized water. After washing, the organic solution was evaporated under reduced pressure. 20 ml of isopropanol was added to the remaining solid, heated to dissolve, and then cooled. A large amount of white powder precipitated. The powder was filtered, and the residue was washed with isopropanol and dried to obtain intermediate I with the structure shown in Formula 3, with a yield of 81.5%.

[0022] Example 2 Preparation of intermediate II: Intermediate I 1 g (1.88 mmol) was dissolved in 35 mL of ethyl acetate, and 0.31 g (2.07 mmol) of anhydrous sodium iodide was added. The mixture was heated and stirred at approximately 70 °C for 1 h. 0.25 g (2.04 mmol) of 2-aminobenzenethiol was placed in 10 mL of water, and 0.08 g (2.04 mmol) of sodium hydroxide was added to the aqueous solution. This aqueous solution was then added to the reaction mixture, and the mixture was heated and stirred at 70 °C for 2 h. The reaction mixture was poured into a separatory funnel, extracted with 30 mL of chloroform, and the organic phase was collected. The obtained organic phase was evaporated by rotary evaporation to obtain a mixture which was then redissolved in dichloromethane. 1 g of 100-200 mesh silica gel was added and mixed thoroughly. After the solvent evaporated, the above crude product-silica gel powder mixture was purified by column chromatography (200-300 mesh silica gel powder as the stationary phase, petroleum ether:ethyl acetate = 1:2 as the mobile phase) to obtain a pure product intermediate II with the structure shown in Formula 4, with a yield of 78.9%.

[0023] Example 3 Preparation of Intermediate III: Chloroacetyl chloride (0.522 g, 4.66 mmol) was dissolved in toluene (15.0 ml, 127.2 mmol). After reacting for 10 min, intermediate II (2 g, 4.24 mmol) was added at room temperature. The mixture was heated in a water bath at 110 °C for 2.5 h. The reaction solution was poured into a separatory funnel and extracted with 30 ml of chloroform. The organic phase was collected. The obtained organic phase was evaporated by rotary evaporation to obtain a mixture, which was then redissolved in dichloromethane. 1 g of 100-200 mesh silica gel was added and mixed thoroughly. After the solvent had evaporated, the above crude product-silica gel powder mixture was purified by column chromatography (200-300 mesh silica gel powder as the stationary phase, petroleum ether:ethyl acetate = 2:1 as the mobile phase) to obtain the product intermediate with the structure shown in Formula 5. The pure product has a yield of 85.7%.

[0024] Example 4 Preparation of 22-O-[(2-(2-(1-(2-pyrimidinyl)piperazinyl)acetamido)phenyl)]thioacetylmuel (compound 1) Intermediate III 2 g (3.56 mmol) was dissolved in 30 mL of acetonitrile, and 0.644 g (3.91 mmol) of 1-(2-pyrimidinyl)piperazinyl and 1.48 g (10.68 mmol) of anhydrous potassium carbonate were added. The mixture was heated and stirred at about 8 °C for 2 h to obtain the target product. The resulting mixed solution was evaporated to dryness by rotary evaporation, and the mixture was redissolved in dichloromethane. 2.5 g of 100-200 mesh silica gel was added and mixed thoroughly. After the solvent evaporated completely, the above crude product-silica gel powder mixture was purified by column chromatography (200-300 mesh silica gel powder as the stationary phase, dichloromethane:methanol = 60:1 as the mobile phase) to obtain product 22-O-[(2-(2-(1-(2-pyrimidinyl)piperazinyl)acetamido)phenyl)]thioacetylmuel] with a yield of 40.70%.

[0025] Example 5 Preparation of 22-O-[(2-(2-(dimethylamino)acetamido)phenyl)]thioacetylmuel (compound 2) Intermediate III 2g (3.56mmol) was dissolved in 30ml acetonitrile, and 0.176g (3.92mmol) of dimethylamine and 1.48g (10.68mmol) of anhydrous potassium carbonate were added. The mixture was heated and stirred at approximately 78℃ for 5h to obtain the target product. The resulting mixed solution was evaporated to dryness by rotary evaporation, and the mixture was reconstituted in dichloromethane. 2g of 100-200 mesh silica gel was added and mixed thoroughly. After the solvent evaporated completely, the above crude product-silica gel powder mixture was purified by column chromatography (200-300 mesh silica gel powder as the stationary phase, petroleum ether:ethyl acetate = 1:1 as the mobile phase) to obtain product 22-O-[(2-(2-(dimethylamino)acetamido)phenyl)]thioacetylmuel, with a yield of 55.25%.

[0026] Example 6 Preparation of 22-O-[2-(2-benzimidazolyl-acetamido)phenyl]thioacetylmuel (compound 3) Intermediate III 2 g (3.56 mmol) was dissolved in 30 mL of acetonitrile, and 0.462 g (3.91 mmol) of benzimidazole and 1.48 g (10.68 mmol) of anhydrous potassium carbonate were added. The mixture was heated and stirred at approximately 78 °C for 5 h to obtain the target product. The resulting mixed solution was evaporated to dryness by rotary evaporation, and the mixture was reconstituted in dichloromethane. 2.5 g of 100-200 mesh silica gel was added and mixed thoroughly. After the solvent had evaporated completely, the above crude product-silica gel powder mixture was purified by column chromatography (200-300 mesh silica gel powder as the stationary phase, dichloromethane:methanol = 20:1 as the mobile phase) to obtain product 22-O-[2-(2-benzimidazolyl-acetamido)phenyl]thioacetylmuel, with a yield of 36.72%.

[0027] Example 7 Preparation of 22-O-[2-(2-(2-methylimidazolium)acetamido)phenyl]thioacetylmuel (compound 4) Intermediate III 2g (3.56mmol) was dissolved in 30ml acetonitrile, and 0.32g (3.91mmol) of 2-methylimidazole and 1.48g (10.68mmol) of anhydrous potassium carbonate were added. The mixture was heated and stirred at about 78℃ for 3h to obtain the target product. The resulting mixed solution was evaporated to dryness by rotary evaporation, and the mixture was redissolved in dichloromethane. 2g of 100-200 mesh silica gel was added and mixed thoroughly. After the solvent evaporated completely, the above crude product-silica gel powder mixture was purified by column chromatography (200-300 mesh silica gel powder as the stationary phase, dichloromethane:methanol = 80:1 as the mobile phase) to obtain product 22-O-[2-(2-(2-methylimidazole)acetamido)phenyl]thioacetylmuel, yield 19.25%.

[0028] Example 8 Preparation of 22-O-[2-(2-azacyclobutane-acetamido)phenyl]thioacetylmuel (compound 5) Intermediate III 2 g (3.56 mmol) was dissolved in 30 mL of acetonitrile, and 0.223 g (3.91 mmol) of aziridine and 1.48 g (10.68 mmol) of anhydrous potassium carbonate were added. The mixture was heated and stirred at approximately 78 °C for 3 h to obtain the target product. The resulting mixed solution was evaporated to dryness by rotary evaporation, and the mixture was reconstituted in dichloromethane. 2 g of 100-200 mesh silica gel was added and mixed thoroughly. After the solvent had evaporated completely, the above crude product-silica gel powder mixture was purified by column chromatography (200-300 mesh silica gel powder as the stationary phase, dichloromethane:methanol = 200:1 as the mobile phase) to obtain the product 2-O-[2-(2-aziridine-acetamido)phenyl]thioacetylmuel, with a yield of 57.58%.

[0029] Example 9 Preparation of 22-O-[2-(2-(4-methylimidazolium)acetamido)phenyl]thioacetylmuel (compound 6) Intermediate III 2g (3.56mmol) was dissolved in 30ml acetonitrile, and 0.32g (3.91mmol) of 4-methylimidazole and 1.48g (10.68mmol) of anhydrous potassium carbonate were added. The mixture was heated and stirred at about 78℃ for 3h to obtain the target product. The resulting mixed solution was evaporated to dryness by rotary evaporation, and the mixture was redissolved in dichloromethane. 2g of 100-200 mesh silica gel was added and mixed thoroughly. After the solvent evaporated completely, the above crude product-silica gel powder mixture was purified by column chromatography (200-300 mesh silica gel powder as the stationary phase, dichloromethane:methanol = 80:1 as the mobile phase) to obtain product 22-O-[2-(2-(4-methylimidazole)acetamido)phenyl]thioacetylmuel, with a yield of 35.41%.

[0030] Example 10 Preparation of 22-O-[2-(2-imidazolylacetamido)phenyl]thioacetylmuel (compound 7) Intermediate III 2g (3.56mmol) was dissolved in 30ml acetonitrile, and imidazole 0.267g (3.91mmol) and anhydrous potassium carbonate 1.48g (10.68mmol) were added. The mixture was heated and stirred at about 78℃ for 3h to obtain the target product. The resulting mixed solution was evaporated to dryness by rotary evaporation, and the mixture was redissolved in dichloromethane. 2g of 100-200 mesh silica gel was added and mixed thoroughly. After the solvent evaporated completely, the above crude product-silica gel powder mixture was purified by column chromatography (200-300 mesh silica gel powder as the stationary phase, dichloromethane:methanol = 200:1 as the mobile phase) to obtain product 22-O-[2-(2-imidazolylacetamido)phenyl]thioacetylmuel, with a yield of 27.60%.

[0031] Example 11 Preparation of 22-O-[2-(2-(4-methylpiperidine)acetamido)phenyl]thioacetylmuel (compound 8) Intermediate III 2 g (3.56 mmol) was dissolved in 30 mL of acetonitrile, and 0.35 g (3.91 mmol) of 4-methylpiperidine and 1.48 g (10.68 mmol) of anhydrous potassium carbonate were added. The mixture was heated and stirred at approximately 75 °C for 3 h to obtain the target product. The resulting mixed solution was evaporated to dryness by rotary evaporation, and the mixture was reconstituted in dichloromethane. 2 g of 100-200 mesh silica gel was added and mixed thoroughly. After the solvent had evaporated completely, the above crude product-silica gel powder mixture was purified by column chromatography (200-300 mesh silica gel powder as the stationary phase, dichloromethane:methanol = 60:1 as the mobile phase) to obtain product 22-O-[2-(2-(4-methylpiperidine)acetamido)phenyl]thioacetylmuel, with a yield of 44.53%.

[0032] Example 12 Preparation of 22-O-[2-(2-(imidazol-2-carboxaldehyde)acetamido)phenyl]thioacetylmuel (compound 9) Intermediate III 2g (3.56mmol) was dissolved in 30ml acetonitrile, and 0.377g (3.91mmol) of imidazole-2-carboxaldehyde and 1.48g (10.68mmol) of anhydrous potassium carbonate were added. The mixture was heated and stirred at about 78℃ for 3h to obtain the target product. The resulting mixed solution was evaporated to dryness by rotary evaporation, and the mixture was redissolved in dichloromethane. 2g of 100-200 mesh silica gel was added and mixed thoroughly. After the solvent evaporated completely, the above crude product-silica gel powder mixture was purified by column chromatography (200-300 mesh silica gel powder as the stationary phase, dichloromethane:methanol = 100:1 as the mobile phase) to obtain product 22-O-[2-(2-(imidazole-2-carboxaldehyde)acetamido)phenyl]thioacetylmuel, yield 13.60%.

[0033] Example 13 Preparation of 22-O-[2-(2-(2-piperidinol)acetamido)phenyl]thioacetylmuel (compound 10) Intermediate III 2 g (3.56 mmol) was dissolved in 30 mL of acetonitrile, and 0.460 g (3.91 mmol) of 2-piperidine ethanol and 1.48 g (10.68 mmol) of anhydrous potassium carbonate were added. The mixture was heated and stirred at approximately 78 °C for 3 h to obtain the target product. The resulting mixed solution was evaporated to dryness by rotary evaporation, and the mixture was reconstituted in dichloromethane. 2 g of 100-200 mesh silica gel was added and mixed thoroughly. After the solvent evaporated completely, the above crude product-silica gel powder mixture was purified by column chromatography (200-300 mesh silica gel powder as the stationary phase, dichloromethane:methanol = 80:1 as the mobile phase) to obtain product 22-O-[2-(2-(2-piperidine ethanol)acetamido)phenyl]thioacetylmuel, with a yield of 60.20%.

[0034] Example 14 Preparation of 22-O-[2-(2-(4-piperidinylpiperidin)acetamino)phenyl]thioacetylmuel (compound 11) Intermediate III 2 g (3.56 mmol) was dissolved in 30 mL of acetonitrile, and 0.60 g (3.91 mmol) of 4-piperidinylpiperidine and 1.48 g (10.68 mmol) of anhydrous potassium carbonate were added. The mixture was heated and stirred at approximately 78 °C for 3 h to obtain the target product. The resulting mixed solution was evaporated to dryness by rotary evaporation, and the mixture was reconstituted in dichloromethane. 2 g of 100-200 mesh silica gel was added and mixed thoroughly. After the solvent evaporated completely, the above crude product-silica gel powder mixture was purified by column chromatography (200-300 mesh silica gel powder as the stationary phase, petroleum ether:ethyl acetate = 1:1 as the mobile phase) to obtain product 22-O-[2-(2-(1,3-oxazolidine-2-keto)acetamido)phenyl]thioacetylmuel] with a yield of 62.60%.

[0035] Example 15 Preparation of 22-O-[2-(2-(2-pyrrolecarboxaldehyde)acetamido)phenyl]thioacetylmuel (compound 12) Intermediate III 2g (3.56mmol) was dissolved in 30ml acetonitrile, and 0.37g (3.91mmol) of 2-pyrrolecarboxaldehyde and 1.48g (10.68mmol) of anhydrous potassium carbonate were added. The mixture was heated and stirred at about 78℃ for 3h to obtain the target product. The resulting mixed solution was evaporated to dryness by rotary evaporation, and the mixture was redissolved in dichloromethane. 2g of 100-200 mesh silica gel was added and mixed thoroughly. After the solvent evaporated completely, the above crude product-silica gel powder mixture was purified by column chromatography (200-300 mesh silica gel powder as the stationary phase, petroleum ether:ethyl acetate = 2:1 as the mobile phase) to obtain product 22-O-[2-(2-(2-pyrrolecarboxaldehyde acetamido)phenyl]thioacetylmuel, with a yield of 68.80%.

[0036] Example 16 Preparation of 22-O-[2-(2-(N-methyl-n-propylamine)acetamido)phenyl]thioacetylmuel (compound 13) Intermediate III 2 g (3.56 mmol) was added to 30 mL of acetonitrile, along with 0.287 g (3.91 mmol) of N-methyl-n-propylamine and 1.48 g (10.68 mmol) of anhydrous potassium carbonate. The mixture was heated and stirred at approximately 78 °C for 3 h to obtain the target product. The resulting mixed solution was evaporated to dryness by rotary evaporation, and the mixture was reconstituted in dichloromethane. 2 g of 100-200 mesh silica gel was added and mixed thoroughly. After the solvent had evaporated completely, the crude product-silica gel powder mixture was purified by column chromatography (200-300 mesh silica gel powder as the stationary phase, petroleum ether:ethyl acetate = 3:1 as the mobile phase) to obtain product 22-O-[2-(2-(N-methyl-n-propylamine acetamido)phenyl]thioacetylmuel], with a yield of 50.64%.

[0037] Example 17 Preparation of 22-O-[2-(2-(N-methylisopropylamine)acetamido)phenyl]thioacetylmuel (compound 14) Intermediate III 2 g (3.56 mmol) was added to 30 mL of acetonitrile, along with 0.287 g (3.91 mmol) of N-methylisopropylamine and 1.48 g (10.68 mmol) of anhydrous potassium carbonate. The mixture was heated and stirred at approximately 78 °C for 3 h to obtain the target product. The resulting mixed solution was evaporated to dryness by rotary evaporation, and the mixture was reconstituted in dichloromethane. 2 g of 100-200 mesh silica gel was added and mixed thoroughly. After the solvent had evaporated completely, the crude product-silica gel powder mixture was purified by column chromatography (200-300 mesh silica gel powder as the stationary phase, petroleum ether:ethyl acetate = 3:1 as the mobile phase) to obtain product 22-O-[2-(2-(N-methylisopropylamine acetamido)phenyl]thioacetylmuel, with a yield of 54.71%.

[0038] Example 18 Preparation of 22-O-[2-(2-(pyrrolo-2-acrylonitrile)acetamido)phenyl]thioacetylmuel (compound 15) Intermediate III 2 g (3.56 mmol) was dissolved in 30 mL of acetonitrile, and 0.361 g (3.91 mmol) of pyrrolo-2-acrylonitrile and 1.48 g (10.68 mmol) of anhydrous potassium carbonate were added. The mixture was heated and stirred at approximately 78 °C for 3 h to obtain the target product. The resulting mixed solution was evaporated to dryness by rotary evaporation, and the mixture was reconstituted in dichloromethane. 2 g of 100-200 mesh silica gel was added and mixed thoroughly. After the solvent evaporated completely, the above crude product-silica gel powder mixture was purified by column chromatography (200-300 mesh silica gel powder as the stationary phase, petroleum ether:ethyl acetate = 3:1 as the mobile phase) to obtain product 22-O-[2-(2-(pyrrolo-2-acrylonitrile acetamido)phenyl]thioacetylmuel, with a yield of 40.63%.

[0039] Example 19 Preparation of 22-O-[2-(2-(2,5-dimethylpyrrole)acetamido)phenyl]thioacetylmuel (compound 16) Intermediate III 2g (3.56mmol) was added to 30ml of acetonitrile along with 0.373g (3.91mmol) of 2,5-dimethylpyrrole and 1.48g (10.68mmol) of anhydrous potassium carbonate. The mixture was heated and stirred at approximately 78°C for 3 hours to obtain the target product. The resulting mixed solution was evaporated to dryness by rotary evaporation, and the mixture was reconstituted in dichloromethane. 2g of 100-200 mesh silica gel was added and mixed thoroughly. After the solvent had evaporated completely, the crude product-silica gel powder mixture was purified by column chromatography (200-300 mesh silica gel powder as the stationary phase, petroleum ether:ethyl acetate = 3:1 as the mobile phase) to obtain the product 22-O-[2-(2-(2,5-dimethylpyrrole)acetamido)phenyl]thioacetylmuel, with a yield of 17.73%.

[0040] Example 20 Preparation of 22-O-[2-(2-(N-methylallylamine)acetamido)phenyl]thioacetylmuel (compound 17) Intermediate III 2 g (3.56 mmol) was added to 30 mL of acetonitrile, along with 0.279 g (3.91 mmol) of N-methylallyl and 1.48 g (10.68 mmol) of anhydrous potassium carbonate. The mixture was heated and stirred at approximately 78 °C for 3 h to obtain the target product. The resulting mixed solution was evaporated to dryness by rotary evaporation, and the mixture was reconstituted in dichloromethane. 2 g of 100-200 mesh silica gel was added and mixed thoroughly. After the solvent had evaporated completely, the crude product-silica gel powder mixture was purified by column chromatography (200-300 mesh silica gel powder as the stationary phase, petroleum ether:ethyl acetate = 3:1 as the mobile phase) to obtain product 22-O-[2-(2-(N-methylallylamine)acetamido)phenyl]thioacetylmuel, with a yield of 31.44%.

[0041] Example 21 Preparation of 22-O-[2-(2-(N-methylethanolamine)acetamido)phenyl]thioacetylmuelin (compound 18) Intermediate III 2 g (3.56 mmol) was dissolved in 30 mL of acetonitrile, and 0.294 g (3.91 mmol) of N-methylethanol and 1.48 g (10.68 mmol) of anhydrous potassium carbonate were added. The mixture was heated and stirred at approximately 78 °C for 3 h to obtain the target product. The resulting mixed solution was evaporated to dryness by rotary evaporation, and the mixture was reconstituted in dichloromethane. 2 g of 100-200 mesh silica gel was added and mixed thoroughly. After the solvent had evaporated, the above crude product-silica gel powder mixture was purified by column chromatography (200-300 mesh silica gel powder as the stationary phase, petroleum ether:ethyl acetate = 3:1 as the mobile phase) to obtain product 22-O-[2-(2-(N-methylethanolamine)acetamido)phenyl]thioacetylmuel, with a yield of 54.93%.

[0042] Example 22 Preparation of 22-O-[2-(2-(homomethylpiperazinyl)acetamido)phenyl]thioacetylmuel (compound 19) Intermediate III 2g (3.56mmol) was dissolved in 30ml acetonitrile, and 0.41g (3.91mmol) of homomethylpiperazine and 1.48g (10.68mmol) of anhydrous potassium carbonate were added. The mixture was heated and stirred at about 78℃ for 3h to obtain the target product. The resulting mixed solution was evaporated to dryness by rotary evaporation, and the mixture was redissolved in dichloromethane. 2g of 100-200 mesh silica gel was added and mixed thoroughly. After the solvent evaporated completely, the above crude product-silica gel powder mixture was purified by column chromatography (200-300 mesh silica gel powder as the stationary phase, petroleum ether:ethyl acetate = 1:4 as the mobile phase) to obtain product 22-O-[2-(2-(homomethylpiperazinyl)acetamido)phenyl]thioacetylmuel, with a yield of 36.93%.

[0043] Example 23 Preparation of 22-O-[2-(2-(3,5-dimethyl-2-carboxaldehydepyrrole)acetamido)phenyl]thioacetylmuel (compound 20) Intermediate III 2 g (3.56 mmol) was dissolved in 30 mL of acetonitrile, and 0.483 g (3.91 mmol) of 3,5-dimethyl-2-carboxaldehyde pyrrole and 1.48 g (10.68 mmol) of anhydrous potassium carbonate were added. The mixture was heated and stirred at approximately 78 °C for 3 h to obtain the target product. The resulting mixed solution was evaporated to dryness by rotary evaporation, and the mixture was reconstituted in dichloromethane. 2 g of 100-200 mesh silica gel was added and mixed thoroughly. After the solvent had evaporated completely, the above crude product-silica gel powder mixture was purified by column chromatography (200-300 mesh silica gel powder as the stationary phase, petroleum ether:ethyl acetate = 3:1 as the mobile phase) to obtain product 22-O-[2-(2-(3,5-dimethyl-2-carboxaldehyde pyrrole)acetamido)phenyl]thioacetylmuel, with a yield of 16.44%.

[0044] Example 24 Preparation of 22-O-[2-(2-(4-carboxynitrileimidazolium)acetamido)phenyl]thioacetylmuel (compound 21) Intermediate III 2g (3.56mmol) was dissolved in 30ml acetonitrile, and 0.365g (3.91mmol) of 4-carboxynitrile imidazole and 1.48g (10.68mmol) of anhydrous potassium carbonate were added. The mixture was heated and stirred at about 78℃ for 3h to obtain the target product. The resulting mixed solution was evaporated to dryness by rotary evaporation, and the mixture was redissolved in dichloromethane. 2g of 100-200 mesh silica gel was added and mixed thoroughly. After the solvent evaporated completely, the above crude product-silica gel powder mixture was purified by column chromatography (200-300 mesh silica gel powder as the stationary phase, petroleum ether:ethyl acetate = 3:1 as the mobile phase) to obtain product 22-O-[2-(2-(4-carboxynitrile imidazole)acetamido)phenyl]thioacetylmuel, with a yield of 45.80%.

[0045] Example 26 The yields of the compounds obtained in the above examples are summarized in Table 6.

[0046] Table 6. Compound Numbers and Yields Example: In vitro mycoplasma inhibition experiment The experiment used the agar dilution method to determine the minimum inhibitory concentration (MIC) of this type of compound. Tiamulin was used as the control drug. Tiamulin is a truncated pleurotin antibiotic and one of the world's top ten veterinary antibiotics.

[0047] The strains used in the experiment were Mycoplasma gallisepticum 352, Mycoplasma tamiflu 352, and Mycoplasma gallisepticum M47.

[0048] Preparation of target compound stock solutions: Accurately weigh the target compounds (compounds 1-21 prepared in Examples 4-24) and place them in 1 mL of DMF. Then, dilute them to an initial concentration of 5120 μg / mL in a 250 mL volumetric flask to obtain the stock solutions. After obtaining the stock solutions, sterilize them by filtering through a 0.22 μm filter membrane, aliquot them, and store them at -20°C. The control drug tiamulin was prepared in the same manner as above. The above stock solutions were serially diluted in petri dishes, with each dish containing 2 mL of the drug solution. The solution was then diluted to 20 mL with melted MH medium to obtain final concentrations of the test compounds in the series of petri dishes of 64, 32, 16, 8, 4, 2, 1, 0.5, 0.25, 0.125, 0.0623135, 0.0313, 0.0152, 0.00075, and 0.0004 μg / mL, respectively.

[0049] Table 7 shows the MIC results, which indicate that the target compound has good mycoplasma inhibitory activity against the selected strains.

[0050] Table 7. In vitro antibacterial data of the derivatives As shown in the table above, these derivatives have good inhibitory activity against Mycoplasma gallisepticum, comparable to tiamulin, and some derivatives show superior anti-mycoplasma activity against Mycoplasma gallisepticum 352 compared to tiamulin.

[0051] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. The use of a truncated pleurotin derivative with a nitrogen-containing heterocyclic or alkylamine side chain in the preparation of a drug for the prevention and treatment of Mycoplasma gallisepticum, characterized in that: The truncated pleurotin derivative with a nitrogen-containing heterocyclic or alkylamine side chain is a compound with the structure shown in Formula 2 or a pharmaceutically acceptable salt thereof: Formula 2 Where R is , , , , , , , ; R1 is methyl and R2 is methyl; or R1 is methyl and R2 is propyl; or R1 is methyl and R2 is isopropyl; or R1 is methyl and R2 is hydroxyethyl; or R1 is methyl and R2 is propenyl. R3 is a hydrogen atom, R4 is a formaldehyde group, R5 is a hydrogen atom, and R6 is a hydrogen atom; or R3 is a hydrogen atom, R4 is an acetonitrile group, R5 is a hydrogen atom, and R6 is a hydrogen atom; or R3 is a methyl group, R4 is a methyl group, R5 is a hydrogen atom, and R6 is a hydrogen atom; or R3 is a formaldehyde group, R4 is a methyl group, R5 is a methyl group, and R6 is a hydrogen atom. R7 is a methyl group, R8 is a hydrogen atom, and R9 is a hydrogen atom; or R7 is a hydrogen atom, R8 is a hydrogen atom, and R9 is a nitrile group; or R7 is a hydrogen atom, R8 is a methyl group, and R9 is a hydrogen atom; or R7 is a hydrogen atom, R8 is a hydrogen atom, and R9 is a hydrogen atom; or R7 is a hydrogen atom, R8 is a formaldehyde group, and R9 is a hydrogen atom. The R 10 It is methyl, pyridine, or hydroxyethyl; The R 11 For carbon atoms, R 12 It is a nitrogen atom.

2. The use according to claim 1, characterized in that: The pharmaceutically acceptable salt is a salt formed by a compound with the structure shown in Formula 2 and hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid, acetic acid, fumaric acid, maleic acid, oxalic acid, malonic acid, succinic acid, citric acid, malic acid, methanesulfonic acid, ethanesulfonic acid, benzenesulfonic acid, toluenesulfonic acid, glutamic acid, or aspartic acid.

3. The use according to claim 2, characterized in that: The pharmaceutically acceptable salt has the following structural formula: 。 4. The use according to claim 1, characterized in that: The truncated pleurotin derivative with nitrogen-containing heterocyclic or alkylamine side chains was prepared according to the following method: (1) The truncated pleurotin was reacted with p-toluenesulfonyl chloride to obtain intermediate I with the structure shown in Formula 3; (2) Using 2-aminophenylthiol as a raw material, react with intermediate I to obtain intermediate II with the structure shown in Formula 4; (3) The intermediate II obtained in step (2) is reacted with chloroacetyl chloride to obtain intermediate III with the structure shown in Formula 5; (4) The intermediate III obtained in step (3) is reacted with various secondary amines to obtain truncated pleurotin derivatives with nitrogen-containing heterocyclic or alkylamine side chains. 。 5. The use according to claim 4, characterized in that: The molar ratio of p-toluenesulfonyl chloride to truncated pleurotin in step (1) is 1.1:

1.

6. The use according to claim 4, characterized in that: The reaction described in step (2) specifically involves dissolving sodium hydroxide in pure water to obtain a sodium hydroxide solution, with a molar ratio of sodium hydroxide to intermediate I of 5:1; dissolving intermediate I and 2-aminobenzylthiol in ethyl acetate to obtain a reaction solution; with a molar ratio of intermediate I to 2-aminobenzylthiol of 1:1.1; adding the sodium hydroxide solution dropwise to the reaction solution under ice bath conditions, and reacting at 70°C for 2 hours.

7. The use according to claim 4, characterized in that: The reaction described in step (3) specifically uses toluene as a solvent, the molar ratio of intermediate II to chloroacetyl chloride is 1:1.1, and the reaction conditions are room temperature reaction for 2-3 hours.

8. The use according to claim 4, characterized in that: The reaction described in step (4) involves first dissolving intermediate III in acetonitrile as a solvent, then adding alkali, and heating at 70°C under reflux for 1-3 hours to obtain a reaction solution. The amount of acetonitrile used is 30-40 times the mass of intermediate III, and the molar ratio of alkali to intermediate III is 3:

1. The resulting reaction solution is then heated under reflux with a secondary amine at 70-78°C for 1-3 hours.

9. The use according to claim 8, characterized in that: The alkali mentioned is sodium hydroxide, potassium hydroxide, cesium hydroxide, sodium carbonate, potassium carbonate, or cesium carbonate.

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