Bile acid-norfloxacin compound, preparation method and application of bile acid-norfloxacin compound as antibacterial agent

Abstract

The invention discloses a preparation method of a bile acid-norfloxacin compound, which comprises the following steps: enabling bile acid and norfloxacin to react in a THF (tetrahydrofuran) solvent at 10-30 DEG C for 12-30 hours in the presence of 2-(7-azobenzotriazole)-N, N, N ', N'-tetramethylurea hexafluorophosphate and diisopropylethylamine, and then performing post-treatment to obtain the bile acid-norfloxacin compound. A compound structure combining bile acid and norfloxacin is obtained through condensation reaction of carboxyl of bile acid and piperazinyl of norfloxacin, the antibacterial activity of norfloxacin is remarkably improved through the structure, and the compound not only has a better inhibiting effect on escherichia coli, helicobacter pylori and the like, but also has a better antibacterial effect on norfloxacin. The compound also has a better inhibition effect on pseudomonas aeruginosa, staphylococcus aureus, pneumococcus and the like, and meanwhile, the preparation operation process is simple.

Description

Technical Field

[0001] The invention belongs to the field of medical technology, and specifically relates to a bile acid-norfloxacin complex, a preparation method thereof, and application thereof as an antibacterial agent. Background Art

[0002] Norfloxacin, also known as norfloxacin, has a chemical name of 1-ethyl-6-fluoro-1,4-dihydro-4-oxo-7-(1-piperazinyl)-3-quinolinecarboxylic acid. It is a third-generation quinolone antibacterial drug that inhibits the action of DNA gyrase of pathogenic bacteria in the digestive tract, hinders bacterial DNA replication, and has an inhibitory effect on bacteria. It is widely used in clinical practice because of its broad antibacterial spectrum, few allergic reactions, and mild toxic side effects. Norfloxacin has a good inhibitory effect on Gram-negative bacteria infections such as Escherichia coli, Proteus, Helicobacter pylori, and Clostridium perfringens, but has a poor inhibitory effect on Gram-negative bacteria-Pseudomonas aeruginosa and some Gram-positive bacteria such as Staphylococcus aureus and Pneumococcus. By modifying the structure of quinolones, new antibacterial drugs with better antibacterial activity can be obtained, such as ciprofloxacin with strong anti-Gram-negative bacteria, norfloxacin, ofloxacin, moxifloxacin with strong anti-Gram-positive bacteria, levofloxacin with good broad-spectrum antibacterial activity, etc., and the research on the structural modification of quinolones is still in progress, but the chemical synthesis process of related derivatives generally has more reaction steps and is becoming increasingly complex. Summary of the invention

[0003] The object of the present invention is to provide a bile acid-norfloxacin complex and a preparation method thereof, wherein the complex has an antibacterial activity superior to that of norfloxacin, and the preparation process of the complex of the present invention is simple and convenient, and the complex can be prepared by a one-step reaction and simple post-treatment. Specifically, the present invention adopts the following technical scheme:

[0004] On the one hand, the present invention provides a method for preparing a bile acid / norfloxacin complex, which comprises reacting bile acid and norfloxacin in the presence of 2-(7-azobenzotriazole)-N,N,N',N'-tetramethyluronium hexafluorophosphate (HATU) and diisopropylethylamine (DIPEA) in a THF solvent at 10-30° C. for 12-30 hours, and then post-treating the complex to obtain the complex.

[0005] In the above-mentioned preparation method, preferably, the molar ratio of bile acid, norfloxacin, 2-(7-azobenzotriazole)-N,N,N',N'-tetramethyluronium hexafluorophosphate, and diisopropylethylamine is 1:1.1-1.3:1.1-1.3:1.5-3; more preferably, the molar ratio of bile acid, norfloxacin, 2-(7-azobenzotriazole)-N,N,N',N'-tetramethyluronium hexafluorophosphate, and diisopropylethylamine is 1:1.2:1.2:2.

[0006] In the preparation method described above, preferably, the bile acid is selected from cholic acid, chenodeoxycholic acid or ursodeoxycholic acid; when the bile acid is selected from cholic acid, the reaction is carried out at 25°C overnight; when the bile acid is selected from ursodeoxycholic acid, the reaction is carried out in THF solvent at 15°C for 24 hours.

[0007] On the other hand, when the bile acid is selected from bile acid, the bile acid / norfloxacin complex obtained by the above-mentioned preparation method of the present invention is a bile acid / norfloxacin complex with a molecular formula of C 40 H 56 FN3O7, the structural formula is as follows (I):

[0008]

[0009] On the other hand, when the bile acid is selected from ursodeoxycholic acid, the bile acid / norfloxacin complex obtained by the preparation method of the present invention is ursodeoxycholic acid / norfloxacin complex with a molecular formula of C 40 H 56 FN3O6, the structural formula is as follows (II):

[0010]

[0011]

[0012] The present invention obtains a complex structure of bile acid and norfloxacin by condensing the carboxyl group of bile acid with the piperazine group of norfloxacin. The structure significantly improves the antibacterial activity of norfloxacin, and has better inhibitory effects not only on Escherichia coli, Helicobacter pylori, etc., but also on Pseudomonas aeruginosa, Staphylococcus aureus, Pneumococcus, etc. At the same time, the preparation operation process of the present invention is simple. DETAILED DESCRIPTION

[0013] The following embodiments are further descriptions of the content of the present invention as an explanation of the technical content of the present invention, but the essential content of the present invention is not limited to the following embodiments. Ordinary technicians in this field can and should know that any simple changes or replacements based on the essential spirit of the present invention should fall within the scope of protection required by the present invention.

[0014] Example 1

[0015] The preparation method of bile acid / norfloxacin complex has the following process route:

[0016]

[0017] The feeding conditions are shown in Table 1:

[0018] Table 1: Feeding conditions

[0019] name Relative molecular weight Feeding amount Molar Ratio source cholic acid 408.5 6g 1.0 Braun CA2171202 Norfloxacin 319.3 5.6g 1.2eq Peter CMU114 HATU 380.24 6.7g 1.2eq Maclean DIPEA 129.24 3.8g 2.0eq Maclean THF / 100mL / Cologne

[0020] The specific operation process is as follows:

[0021] 6 g of cholic acid was added to 100 ml of THF, followed by 6.7 g of HATU and 3.8 g of DIPEA, and finally 5.6 g of norfloxacin. The mixture was reacted overnight at room temperature at 25°C, and the reaction was monitored by TLC (developed by EA and developed by phosphomolybdic acid). After the reaction was complete, the mixture was purified by silica gel column (eluent EA), and then slurried with ethyl acetate after being spin-dried to obtain 4 g of white powder.

[0022] Structure confirmation:

[0023] 1 HNMR (400MHz, DMSO) δ: 15.33 (s, 1H), 8.94 (s, 1H), 7.88 (d, J = 12Hz, 1H), 7.17 (d, J = 6.4Hz, 1H), 4.58(d,J=6.8Hz,2H),4.04-3.79(m,6H),3.67-3.17(m,9H),2.40-0.79(m,33H),0.58(s,3H).

[0024] ESI-MS m / z:710.60[M+1].

[0025] Example 2

[0026] The preparation method of ursodeoxycholic acid / norfloxacin complex has the following process route:

[0027]

[0028] The feeding conditions are shown in Table 2:

[0029] Table 2: Feeding conditions

[0030] name Relative molecular weight Feeding amount Molar Ratio source Ursodeoxycholic acid 392.58 4g 1.0 Lark Norfloxacin 319.3 3.9g 1.2eq Peter HATU 380.24 4.7g 1.2eq Anaiji Diisopropylethylamine 129.24 2.6g 2eq Maclean THF / 80mL / Cologne

[0031] The specific operation process is as follows:

[0032] Ursodeoxycholic acid, norfloxacin, HATU, diisopropylethylamine and THF were added to the reaction bottle, stirred at 15°C for 24 hours, and monitored by TLC (dichloromethane / methanol = 10:1, phosphomolybdic acid color development) after the reaction was completed. Filter by suction, mix the mother liquor with silica gel column for purification (eluent dichloromethane / methanol = 10:1), and add ethyl acetate / methanol (20:1) 200ml to obtain the product, beat for 2 hours, filter by suction, and dry with air at 70°C to obtain 4.7g.

[0033] Structure confirmation:

[0034] 1 H NMR (400MHz, DMSO) δ15.32(s,1H),8.96(s,1H),7.93(d,J=13.2Hz,1H),7.19(d,J=7.2Hz,1H),4.59(q,J=6.8Hz,2H),4.43(d,J=4.4 Hz,1H),3.86(d,J=6.7Hz,1H),3.67(s,4H),2.33(ddd,J=36.3,9.8,5.3Hz,2H),2.02-1.01(m,31H),0.99-0.83(m,8H),0.62(s,3H).

[0035] ESI-MS m / z: 694.6[M+1] 。

[0036] Example 3

[0037] In vitro antibacterial activity experiment:

[0038] Experimental method: Helicobacter pylori (ATCC43504) was inoculated in MH medium (microaerobic environment) and incubated at 37°C for 20h; Pseudomonas aeruginosa (ATCC27853) and Escherichia coli (ATCC25922) were inoculated in MH medium and incubated at 37°C for 17-20h; Pneumococcus (ATCC49619) was inoculated in MH medium (containing 5% sheep blood) and incubated at 35-37°C and 5% carbon dioxide for 24h; Staphylococcus aureus (ATCC6538) was inoculated in MH medium (2% NaCl) and incubated at 37°C for 24h; the test bacteria were diluted to 10 5 The bile acid / norfloxacin complex of the present invention was tested for minimum inhibitory concentration (MIC) by using agar double concentration dilution method, and norfloxacin, bile acid and ursodeoxycholic acid were used as controls. The results are shown in Table 3:

[0039] Table 3: In vitro antibacterial activity test

[0040]

[0041]

[0042] From the in vitro antibacterial results in Table 3 above, it can be seen that the antibacterial activity of the bile acid-norfloxacin complex obtained in Example 1 of the present invention and the ursodeoxycholic acid-norfloxacin complex obtained in Example 2 against Escherichia coli ATCC25922, Helicobacter pylori ATCC43504, Pseudomonas aeruginosa ATCC27853, Pneumococcus ATCC49619, and Staphylococcus aureus ATCC6538 is significantly better than that of norfloxacin, and is also significantly higher than the inhibitory activity of bile acid or ursodeoxycholic acid against the corresponding bacteria. The bile acid-norfloxacin complex and the ursodeoxycholic acid-norfloxacin complex of the present invention exhibit excellent antibacterial properties.

[0043] It should be noted that the above-mentioned technical contents of the present invention are only for explanation and clarification to enable those skilled in the art to understand the technical essence of the present invention, so the technical contents are not used to limit the substantial protection scope of the present invention. The substantial protection scope of the present invention shall be subject to the claims. Those skilled in the art should know that any modification, equivalent substitution and improvement based on the substantial spirit of the present invention shall be within the substantial protection scope of the present invention.

Claims

1. A method for preparing a bile acid / norfloxacin complex, characterized in that: The bile acid and norfloxacin are reacted in the presence of 2-(7-azobenzotriazole)-N,N,N',N'-tetramethyluronium hexafluorophosphate and diisopropylethylamine in a THF solvent at 10-30° C. for 12-30 hours, followed by post-treatment to obtain the product.

2. The preparation method according to claim 1, characterized in that The molar ratio of bile acid, norfloxacin, 2-(7-azobenzotriazole)-N,N,N',N'-tetramethyluronium hexafluorophosphate and diisopropylethylamine is 1:1.1-1.3:1.1-1.3:1.5-3.

3. The preparation method according to claim 2, characterized in that: The molar ratio of bile acid, norfloxacin, 2-(7-azobenzotriazole)-N,N,N',N'-tetramethyluronium hexafluorophosphate and diisopropylethylamine is 1:1.2:1.2:

2.

4. The preparation method according to any one of claims 1 to 3, characterized in that: The bile acid is selected from cholic acid, chenodeoxycholic acid or ursodeoxycholic acid.

5. The preparation method according to claim 4, characterized in that: The bile acid is selected from cholic acid and reacted in THF solvent at 25° C. overnight.

6. The preparation method according to claim 4, characterized in that: The bile acid is selected from ursodeoxycholic acid and reacted in THF solvent at 15° C. for 24 hours.

7. The bile acid / norfloxacin complex obtained by the preparation method of claim 5 has the following structural formula (I):

8. The bile acid / norfloxacin complex obtained by the preparation method of claim 6 has the following structural formula (II):

9. Use of the bile acid / norfloxacin complex obtained by the preparation method according to any one of claims 1 to 6 as an antibacterial agent.

10. Use of the bile acid / norfloxacin complex according to claim 7 or 8 as an antibacterial agent.

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