Pleuromutilin derivative as well as preparation method and application thereof

Abstract

The invention discloses a pleuromutilin derivative as well as a preparation method and application thereof, and belongs to the field of medical chemistry. The compound is synthesized in two steps by taking furfuryl furfural as a starting material through a sulfo reaction and then carrying out a substitution reaction with pleuromutilin, and finally recrystallizing through a mixed solvent to obtain a refined product. The synthesis method is low in production cost, safe to operate and suitable for industrial production. Preliminary biological activity tests show that the compound has good activity on staphylococcus aureus, drug-resistant staphylococcus aureus and staphylococcus intermedius, and has development value when being used as a novel antibacterial drug for preventing and treating infectious diseases caused by staphylococcus aureus and staphylococcus intermedius of human and / or animals. Structural formula (I) of pleuromutilin derivative: # imgabs0 #

Description

Technical Field

[0001] The invention belongs to the field of pharmaceutical chemistry, and specifically relates to a pleuromutilin derivative and a preparation method and application thereof. Background Art

[0002] Staphylococcus aureus is a Gram-positive bacterium and one of the main pathogenic bacteria with high incidence. With the long-term and large-scale use of antibiotics, drug resistance has developed, such as methicillin-resistant Staphylococcus aureus and vancomycin-resistant Staphylococcus aureus. Pleuromutilin and its derivatives have good inhibitory activity against Staphylococcus aureus. Compared with other parent-core antibiotics, there are only 4 pleuromutilin drugs on the market, with low drug resistance and huge market development prospects.

[0003] Pleuromutilin is a tricyclic amphipathic compound with antibacterial activity isolated from higher fungi Pleurotus multilus (Fr.) Sacc. and Pleurotus Passecke-rianus Pilat. Pleuromutilin selectively inhibits bacterial protein synthesis by interacting with the 23S rRNA of the 50s ribosomal subunit, and has a significant inhibitory effect on most Gram-positive bacteria, some Gram-negative bacteria and mycoplasmas. Due to its unique mechanism of action and its different nucleus structure from common clinical antibacterial drugs, it is not easy to produce cross-resistance with other antibacterial drugs, so the research on pleuromutilin derivatives is of great significance. Summary of the invention

[0004] The present invention aims to solve the technical problems in the prior art and provides a pleuromutilin derivative and a preparation method and application thereof.

[0005] To achieve the above purpose, the specific technical solution of the present invention is as follows:

[0006] The present invention provides a pleuromutilin derivative as shown in formula (I):

[0007]

[0008] In a second aspect, the present invention provides a method for preparing a pleuromutilin derivative as shown in formula (I), comprising the following steps:

[0009] (1) Dissolve sodium bisulfite in solvent A, add 2-furoyl chloride dropwise at room temperature, stir to react, cool, adjust pH, extract with ethyl acetate, combine the organic phases, wash and dry to obtain an intermediate;

[0010]

[0011] (2) The catalyst and pleuromutilin are dissolved in solvent B, sodium hydroxide is added under ice bath, the temperature is raised to react, the temperature is cooled to room temperature, the mixture is added to the ethyl acetate solvent containing the intermediate obtained in step (1), the temperature is raised to reflux to react, the temperature is cooled to room temperature, the mixture is filtered, and the filter cake is washed with water to obtain:

[0012]

[0013] (3) Add the filter cake obtained in step (2) into a mixed solvent of acetonitrile and methanol, heat and reflux for 30 minutes, cool to room temperature, precipitate the fine product, filter, wash the filter cake with water, and dry the filter cake to obtain the pure product.

[0014] Furthermore, in step (1), the solvent A is water; the volume mass ratio of the solvent A to sodium bisulfite is 8-12:1 (ml:g); and the molar ratio of the 2-furoyl chloride to sodium bisulfite is 1:1-1.3.

[0015] Furthermore, the catalyst in step (2) is one or more of methanesulfonyl chloride, trifluoromethanesulfonyl chloride, and hydrobromic acid; preferably, the catalyst is methanesulfonyl chloride.

[0016] Furthermore, the molar ratio of the amount of the catalyst used in step (2) to sodium bisulfite is 1:1-1.2.

[0017] Furthermore, in step (2), the molar ratio of pleuromutilin to 2-furanthiocarboxylic acid is 1:0.7-5, preferably 1:0.9-2.

[0018] Furthermore, in step (2), the solvent B is methyl tert-butyl ether; the volume mass ratio of the solvent B to the catalyst is 2-10:1 (ml:g), preferably 4-8:1 (ml:g).

[0019] Furthermore, the temperature of the temperature-raising reaction is 20-80°C, preferably the temperature of the temperature-raising reaction is 30-50°C.

[0020] Furthermore, the volume ratio of acetonitrile to methanol in the mixed solvent in step (3) is 1:1-30, preferably 1:10.

[0021] The third aspect of the present invention also provides a pharmaceutical composition comprising a pleuromutilin derivative represented by formula (I), wherein the pharmaceutical composition further comprises one or more pharmaceutically acceptable carriers and / or excipients.

[0022] The fourth aspect of the present invention provides the use of a pleuromutilin derivative represented by formula (I) or a pharmaceutical composition thereof in the preparation of an antibacterial drug.

[0023] Furthermore, the antibacterial drug is a drug for preventing and treating Gram-positive bacterial infections in humans and / or non-human mammals.

[0024] Furthermore, the Gram-positive bacteria are Staphylococcus aureus, drug-resistant Staphylococcus aureus, and Staphylococcus intermedius.

[0025] Furthermore, the mammal is a ruminant, livestock, poultry, dog or cat.

[0026] The pleuromutilin derivatives of formula (I) of the present invention also have enantiomers and pharmaceutically acceptable salts, which are converted into compounds of formula (I) in vivo.

[0027] The pleuromutilin derivatives represented by formula (I) can also form salts with the following acids: hydrochloric acid, sulfuric acid, phosphoric acid, fumaric acid, maleic acid, citric acid, methanesulfonic acid, and toluenesulfonic acid.

[0028] The pharmaceutical composition of the present invention can be administered in various known ways, such as orally, parenterally, or by spraying. The pharmaceutical composition of the present invention can be administered alone or in combination with other drugs. The oral composition can be in any oral acceptable dosage form, including but not limited to tablets, capsules, emulsions, suspensions, dispersions, and solutions. Commonly used pharmaceutically acceptable carriers or excipients include stabilizers, diluents, surfactants, lubricants, antioxidants, adhesives, colorants, fillers, emulsifiers, etc.

[0029] Beneficial effects:

[0030] The pleuromutilin derivatives reported in the present invention are a new type of compound with strong activity against Staphylococcus aureus, anti-resistant Staphylococcus aureus, anti-intermediate Staphylococcus, etc., and are expected to be developed into new antibacterial drugs for the prevention and treatment of bacterial infectious diseases in humans or animals, and have broad prospects for clinical use. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is the mass spectrum of the compound of formula (I);

[0032] Figure 2 A compound of formula (I) 1 H-NMR spectrum. DETAILED DESCRIPTION

[0033] The preparation method of the compound of general formula I of the present invention is described below in conjunction with specific examples, but these specific methods do not constitute any limitation to the present invention. The compound of the present invention can also be conveniently prepared by optionally combining various synthetic methods described in this specification or known in the art, and such a combination can be easily carried out by a technician in the field to which the present invention belongs.

[0034] The starting materials, reaction reagents, etc. used in the specific embodiments of the present invention are all commercially available. The present invention can adopt the salt-forming method commonly used in the art to prepare the salt form.

[0035] The experimental methods in the examples of the present invention where specific conditions are not specified are generally carried out under conventional conditions or under conditions recommended by raw material or product manufacturers.

[0036] The structures of all compounds in the examples were determined by waters QDa mass spectrometry and H NMR spectra ( 1 H-NMR) characterization.

[0037] Example 1

[0038] Preparation of compounds of formula (I)

[0039]

[0040] (1) Dissolve 2.3 g of sodium bisulfite in 18.5 mL of water, add 2.9 g of compound 1 (2-furoyl chloride) dropwise at room temperature, continue stirring and reacting 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 ethyl acetate 10 mL × 3, combine the organic phases, wash once with saturated brine, and dry over anhydrous sodium sulfate to obtain the ethyl acetate solution of compound 2 (intermediate) that is directly used in the next step without desolventizing. [M+H] + :129.1.

[0041] (2) Dissolve 2.5 g of methanesulfonyl chloride and 4.2 g of pleuromutilin in 20 mL of methyl tert-butyl ether, add 10 mL of 10 M sodium hydroxide in an ice bath, raise the temperature to 20° C. to react for 1 h, cool to room temperature, add an ethyl acetate solution of compound 2, continue to heat and reflux to react for 1 h, cool to room temperature, filter, and wash the filter cake with water.

[0042] (3) The filter cake was added to 30 mL of a mixed solvent of acetonitrile and methanol in a volume ratio of 1:1, heated and refluxed for 30 min, cooled to room temperature for 4 h, and the fine product was precipitated. The filter cake was filtered, washed with water, and dried to obtain the pure product. The yield was 85% (based on the crude product). [M+H] + :489.2, 1 H-NMR(DMSO-d6,300MHz)δ:8.05(s,1H),7.45(d,1H),6.78(d,1H),6.17(t,1 H),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 2

[0044] Preparation of compounds of formula (I)

[0045]

[0046] (1) Dissolve 3.2 g of sodium bisulfite in 32 mL of water, add 3.1 g of compound 1 (2-furoyl chloride) dropwise at room temperature, continue stirring and reacting 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 ethyl acetate 10 mL × 3, combine the organic phases, wash once with saturated brine, and dry over anhydrous sodium sulfate to obtain the ethyl acetate solution of compound 2 (intermediate) that is directly used in the next step without desolventizing. [M+H] + :129.1.

[0047] (2) 4.3 g of trifluoromethanesulfonyl chloride and 9.0 g of pleuromutilin were dissolved in 30 mL of methyl tert-butyl ether, 10 mL of 10 M sodium hydroxide was added under ice bath, the temperature was raised to 80° C. for reaction for 1 h, the temperature was lowered to room temperature, an ethyl acetate solution of compound 2 was added, the temperature was further raised to reflux for reaction for 1 h, the temperature was lowered to room temperature, the mixture was filtered, and the filter cake was washed with water.

[0048] (3) The solid was added to 35 mL of a mixed solvent of acetonitrile and methanol in a volume ratio of 1:10, heated and refluxed for 30 min, cooled to room temperature for 4 h, and the fine product precipitated. The product was filtered, the filter cake was washed with water, and the filter cake was dried to obtain the pure product. The yield was 76% (based on the crude product). [M+H] + :489.2.

[0049] Example 3

[0050] Preparation of compounds of formula (I)

[0051]

[0052] (1) Dissolve 5.8 g of sodium bisulfite in 70 mL of water, add 2.6 g of compound 1 (2-furoyl chloride) dropwise at room temperature, continue stirring and reacting 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 ethyl acetate 10 mL × 3, combine the organic phases, wash once with saturated brine, dry over anhydrous sodium sulfate, and obtain the ethyl acetate solution of compound 2 (intermediate) that is directly used in the next step without spin drying. [M+H] + :129.14.

[0053] (2) 4.5 g of hydrobromic acid and 13.9 g of pleuromutilin were dissolved in 20 mL of methyl tert-butyl ether, 10 mL of 10 M sodium hydroxide was added under ice bath, the temperature was raised to 30° C. for reaction for 1 h, the temperature was lowered to room temperature, an ethyl acetate solution of compound 2 was added, the temperature was raised to reflux for reaction for 1 h, the temperature was lowered to room temperature, the mixture was filtered, and the filter cake was washed with water.

[0054] (3) The solid was added to 40 mL of a mixed solvent of acetonitrile and methanol in a volume ratio of 1:30, heated and refluxed for 30 min, cooled to room temperature for 4 h, and the fine product was precipitated. The filter cake was washed with water and dried to obtain the pure product. The yield was 82% (based on the crude product). [M+Na] + :511.08.

[0055] Example 4 In vitro antibacterial activity study

[0056] The minimum inhibitory concentration of the pleuromutilin derivative obtained in Example 1 of the present invention against standard Staphylococcus aureus (ATCC 29213), clinical drug-resistant Staphylococcus aureus (ATCC43300), and Staphylococcus intermedius (ATCC 29663) was determined by broth dilution method, with tylosin as the positive control drug. The concentration of the bacterial solution in each test well was about 1×10 6 CFU·mL, the drug concentrations were 32, 16, 8, 4, 2, 1, 0.5, 0.25, 0.125, and 0.06, and the inoculated 96-well plate was placed in a 37°C incubator for culture, and the bacterial growth was observed for 24 hours. The results are shown in Table 1:

[0057] Table 1 Minimum inhibitory concentration in vitro of pleuromutilin derivatives (μg / mL)

[0058]

[0059] Conclusion: The antibacterial activity of the pleuromutilin derivatives of the present invention against standard Staphylococcus aureus (ATCC 29213), clinically resistant Staphylococcus aureus (ATCC43300), and Staphylococcus intermedius (ATCC 29663) in vitro is superior to that of the control drug tylosin, and has broad clinical application prospects and great development value.

Claims

1. A pleuromutilin derivative, characterized in that: The pleuromutilin derivative has a structural formula as described in formula (I):

2. The method for preparing a pleuromutilin derivative as claimed in claim 1, characterized in that: The steps include: (1) Dissolve sodium bisulfite in solvent A, add 2-furoyl chloride dropwise at room temperature, stir to react, cool, adjust pH, extract with ethyl acetate, combine the organic phases, wash and dry to obtain an intermediate; (2) dissolving the catalyst and pleuromutilin in solvent B, adding sodium hydroxide under ice bath, heating to react, cooling to room temperature, adding to the ethyl acetate solution containing the intermediate obtained in step (1), heating to reflux to react, cooling to room temperature, filtering, and washing the filter cake with water; (3) Add the filter cake obtained in step (2) into a mixed solvent of acetonitrile and methanol, heat and reflux for 30 minutes, cool to room temperature, precipitate the fine product, filter, wash the filter cake with water, and dry the filter cake to obtain the pure product.

3. The preparation method according to claim 2, characterized in that: In step (1), the solvent A is water; the volume mass ratio of the solvent A to sodium bisulfite is 8-12:1; and the molar ratio of the 2-furoyl chloride to sodium bisulfite is 1:1-1.

3.

4. The preparation method according to claim 2, characterized in that: In step (2), the catalyst is one or more of methanesulfonyl chloride, trifluoromethanesulfonyl chloride and hydrobromic acid; the molar ratio of the catalyst to sodium bisulfite is 1:1-1.2; the molar ratio of pleuromutilin to 2-furanthiocarboxylic acid is 1:0.7-5; the solvent B is methyl tert-butyl ether; and the temperature of the temperature-raising reaction is 20-80°C.

5. The preparation method according to claim 2, characterized in that: The catalyst in step (2) is methanesulfonyl chloride; The molar ratio of pleuromutilin to 2-furanthiocarboxylic acid is 1:0.9-2; and the temperature of the temperature-raising reaction is 30-50°C.

6. The preparation method according to claim 2, characterized in that: The volume ratio of acetonitrile to methanol in the mixed solvent in step (3) is 1:1-30.

7. A pharmaceutical composition, characterized in that It comprises the pleuromutilin derivative according to claim 1, and one or more pharmaceutically acceptable carriers and / or excipients.

8. Use of a pleuromutilin derivative as claimed in claim 1 or a pharmaceutical composition as claimed in claim 7 in the preparation of antibacterial drugs.

9. The use according to claim 8, characterized in that: The antibacterial drug is a drug for preventing and treating Gram-positive bacteria infection in humans and / or non-human mammals.

10. The use according to claim 9, characterized in that: The Gram-positive bacteria are Staphylococcus aureus, drug-resistant Staphylococcus aureus, and Staphylococcus intermedius.

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