A 3-hydroxyquinoline-2-one compound, its synthesis method and application

Abstract

This invention discloses a 3-hydroxyquinoline-2-one compound of formula (IV), its synthesis method, and its applications. It provides a novel therapeutic antibacterial strategy. The synthesized siderophore molecule can be used to conjugate antibiotics, utilizing the bacteria's unique siderophore transport system to target the conjugated antibiotic to its target site. This also provides a potential option for antibacterial drug development. Compared to currently developed siderophores, this provides a green, clean, concise, and efficient synthetic route.

Description

(I) Technical Field

[0001] This invention relates to a 3-hydroxyquinoline-2-one compound, its synthesis method and application, belonging to the fields of fine organic chemistry and biomedicine. (II) Background Technology

[0002] Iron, an essential element in organic organisms, participates in vital biochemical reactions such as DNA synthesis. To absorb free iron ions from the environment, bacteria synthesize and secrete a compound called heptaphilin, which has a strong affinity for ferric ions (Fe3+). Taking advantage of heptaphilin's properties, antibiotics can be coupled to heptaphilin molecules. Utilizing the bacteria's unique heptaphilin transport system, the conjugated antibiotic is targeted and transported to its target site, thereby killing the bacteria.

[0003] To date, more than 500 siderophores derived from bacteria, fungi, and plants have been isolated and identified [SAHA M, SARKAR S, SARKAR B, et al. Microbial siderophores and their potential applications: a review [J]. Environ. Sci. Pollut. R., 2016, 23(5): 3984-3999.]. However, most naturally derived siderophores have complex structures, are difficult to synthesize, and are not conducive to their conjugation with antibiotics.

[0004] Ferrophiles can be classified into natural ferophiles and synthetic ferophiles based on their source. Natural ferophiles have complex and diverse structures and are mainly isolated and identified from bacteria, fungi, and plants, such as enterotoxin secreted by Escherichia coli and chelatin secreted by Pseudomonas aeruginosa.

[0005] To overcome the problem of bacterial resistance caused by the overuse of antibiotics, there is an urgent need for new antibacterial strategies, namely the artificial synthesis of new epidermal ferritins [LING LL, SCHNEIDER T, PEOPLES AJ, et al. Erratum: A new antibiotic kills pathogens without detectable resistance. [J]. Nature, 2015, 520(7547): 388-388.]. (III) Summary of the Invention

[0006] The purpose of this invention is to provide a 3-hydroxyquinoline-2-one compound, its synthesis method and application. The 3-hydroxyquinoline-2-one compound has excellent heparin activity (the compound forms a coordination bond with ferric ions, which makes the compound easier for bacteria to absorb in an iron-deficient environment, and can be used to conjugate with antibiotics, thereby exhibiting better antibacterial effects), and can be used as a novel heparin.

[0007] The technical solution adopted in this invention is as follows:

[0008] In a first aspect, the present invention provides a 3-hydroxyquinoline-2-one compound of formula (Ⅳ):

[0009]

[0010] In equation (Ⅳ), R 1 It can be monosubstituted or polysubstituted, including C1-C3 alkyl, C1-C3 alkoxy, H, halogen, 2-thienyl, 2-nitro, etc.; R 2 It can be benzyl, methyl acetate, ethyl acetate, phenyl acetate, allyl, hydrogen, C1-C3 alkyl, vinyl, 2-thienyl, 2-furanyl, 1-naphthyl, 2-naphthyl, phenyl, 2-nitrophenyl, etc.

[0011] Furthermore, R is preferred. 1 Including ortho-methyl, para-methoxy, H, para-fluorine, para-chloro, and para-bromo; R 2 It can be benzyl (Bn), methyl, ethyl acetate, or allyl.

[0012] Furthermore, the 3-hydroxyquinoline-2-one compound shown in formula (Ⅳ) is preferably one of the following:

[0013]

[0014] Secondly, the present invention provides a method for preparing the 3-hydroxyquinoline-2-one compound shown in formula (Ⅳ), wherein the reaction equation is as follows:

[0015]

[0016] The preparation method of the 3-hydroxyquinoline-2-one compound shown in formula (Ⅳ) includes the following steps:

[0017] (1) Compound (II) and compound (VIII) were reacted in sodium hydride and N,N-dimethylformamide (DMF) from 0°C to room temperature to prepare compound (III);

[0018] (2) Compound (III) was reacted with trimethylsilyl diazomethane and triethylamine (TEA) in ethanol (EtOH) at room temperature to prepare compound (IV);

[0019] In formula (II) R 1 It can be monosubstituted or polysubstituted, including C1-C3 alkyl, C1-C3 alkoxy, H, halogen, 2-thienyl, 2-nitro, etc.;

[0020] In formula (VIII) R 2 Including benzyl, methyl acetate, ethyl acetate, phenyl acetate, allyl, hydrogen, C1-C3 alkyl, vinyl, 2-thienyl, 2-furanyl, 1-naphthyl, 2-naphthyl, phenyl, 2-nitrophenyl, etc.;

[0021] In equation (III), R 1 In the same formula (II), R 1 In equation (III), R 2 In the same formula (VIII), R 2 ;

[0022] In equation (IV), R 1 In the same formula (III), R 1 In equation (IV), R 2 In the same formula (III), R 2 .

[0023] Further, step (1) was carried out as follows: at 0°C, compound (II) was dissolved in N,N-dimethylformamide and stirred until completely dissolved. Then, sodium hydride was slowly added in batches and stirred for 10 min. After that, compound (VIII) was slowly added, the mixture was brought to room temperature, and stirred for 12 h. The reaction was monitored by TLC to indicate completion (the developing solvent was petroleum ether: ethyl acetate = 3:1, v / v). Three times the volume of saturated ammonium chloride aqueous solution of N,N-dimethylformamide was added to an Erlenmeyer flask, and the reaction solution was added dropwise while stirring. After the addition was complete, seven times the volume of distilled water of N,N-dimethylformamide was added and stirred for 1 h. The mixture was then placed in a refrigerator at 5–8°C and left to stand overnight. After a large amount of solid product precipitated, it was filtered. The solid was completely dissolved in ethyl acetate, dried with anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure until completely dry to obtain the solid product, which is compound (III), and used directly in the next reaction. The molar ratio of compound (II) to sodium hydride was 1:1–1.5, preferably 1:1.17; the molar ratio of compound (II) to compound (VIII) was 1:1–1.5, preferably 1:1.15; the volume of N,N-dimethylformamide used was 1 mL / mmol based on the molar amount of compound (II).

[0024] Further, step (2) is carried out as follows: at room temperature, the reaction system is protected by nitrogen throughout the process. Compound (III) and anhydrous ethanol are mixed and stirred until homogeneous. Then triethylamine is added and stirred for 30 min. Next, trimethylsilanized diazomethane is added dropwise using a constant pressure dropping funnel (time controlled at 10 min). After stirring for 15 h, a large amount of solid is precipitated. The solid is monitored by TLC (the developing solvent is petroleum ether: ethyl acetate = 3:1, v / v). After the reaction is completed, the solid is filtered, washed with anhydrous ethanol and dried to obtain compound (IV). The molar ratio of compound (III) to triethylamine is 1:1.5 to 2.2, preferably 1:2. The molar ratio of compound (III) to trimethylsilanized diazomethane is 1:1 to 1.5, preferably 1:1. The volume of anhydrous ethanol used is 3-5 mL / mmol based on the molar amount of compound (III), preferably 4 mL / mmol.

[0025] Thirdly, the present invention also provides the application of the 3-hydroxyquinoline-2-one compound in the preparation of ferrophile.

[0026] Compared with existing technologies, the beneficial effects of this invention are mainly reflected in the following aspects: This invention synthesizes a series of novel 3-hydroxyquinoline-2-one compounds (Ⅳ-1~Ⅳ-9) with heparinetic activity. Compared with currently developed heparins, the 3-hydroxyquinoline-2-one compounds of this invention exhibit stronger heparinetic activity, and the synthetic route is green, clean, simple, and efficient. These 3-hydroxyquinoline-2-one compounds, as siderophore molecules, can be used to conjugate antibiotics to form antibiotic conjugates. Utilizing the unique siderophore transport system of bacteria, the antibiotics conjugated with antibiotic conjugates can be targeted and transported to their target sites, providing a novel antibacterial strategy and offering potential options for antibacterial drug development. (iv) Description of the attached drawings

[0027] Figure 1 The proton spectrum of compound IV-1.

[0028] Figure 2 Carbon spectrum of compound IV-1.

[0029] Figure 3 The proton spectrum of compound IV-7.

[0030] Figure 4 Carbon spectrum of compound IV-7.

[0031] Figure 5 The proton spectrum of compound IV-8.

[0032] Figure 6 Carbon spectrum of compound IV-8.

[0033] Figure 7 Photographs of the ferrophilic activity of compounds IV-1 to IV-9. (V) Detailed Implementation

[0034] The present invention will be further explained and described below with reference to specific embodiments, but the specific embodiments do not limit the present invention in any way. Unless otherwise specified, the reagents and methods involved in the embodiments are all commonly used reagents and methods in the art.

[0035] The room temperature described in this invention is 25–30°C.

[0036] Example 1: Preparation of 3-hydroxyquinoline-2-one IV-1

[0037]

[0038] (1) At 0 °C, 1.8 g (12.18 mmol) of indigo II-1 was added to a 50 mL round-bottom flask and dissolved in 12 mL of N,N-dimethylformamide. The mixture was stirred until completely dissolved. Then, 0.57 g (14.28 mmol) of sodium hydride was added slowly in portions and stirred for 10 min. After that, 1.6 mL (14.04 mmol) of benzyl bromide VIII-1 was added slowly. The mixture was brought to room temperature and stirred for 12 h. The reaction was monitored by TLC (the developing solvent was petroleum ether: ethyl acetate = 3:1, v / v). After the reaction was completed, 36 mL of saturated ammonium chloride aqueous solution (3 times the amount of N,N-dimethylformamide) was added to the conical flask. The reaction solution was added dropwise while stirring. After the addition was completed, 84 mL of distilled water (7 times the amount of N,N-dimethylformamide) was added. After stirring for 1 hour, the mixture was placed in a refrigerator at 5-8°C and left to stand overnight. A large amount of orange solid product precipitated and filtered. The solid was completely dissolved in ethyl acetate, dried with anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure until completely dry to obtain 2.6 g of red solid product, namely N-benzylindigo III-1, with a yield of 90%.

[0039] (2) Under nitrogen protection throughout the reaction at room temperature, 1.185 g (5 mmol) of N-benzylindoin III-1 and 20 mL of anhydrous ethanol were mixed and stirred until homogeneous. Then, 1.4 mL (10 mmol) of triethylamine was added and stirred for 30 min. Next, 2.5 mL (5 mmol) of trimethylsilyldiazomethane was added dropwise using a constant pressure dropping funnel (time controlled at 10 min). The mixture was stirred for 15 h, and a large amount of yellow solid precipitated. The reaction process was monitored by TLC (developing solvent: petroleum ether: ethyl acetate = 3:1, v / v). After the reaction was completed, the solid was filtered, washed with anhydrous ethanol, and dried at 55 °C until completely dry to obtain 0.64 g of 3-hydroxyquinoline-2-one IV-1, with a yield of 51%.

[0040] 1H NMR (500MHz, CDCl3) δ7.32(m,2H),7.28(s,1H),7.20(m,5H),7.12(s,1H),7.05–6.99(m,1H),5.61(s,2H). 13 C NMR (126MHz, CDCl3) δ159.3,157.6,145.1,135.3,130.4,129.0,127.7,126.5,123.0,116.6,115.0,112.6,110.9,47.2.HRMS(ESI)m / z Calcd.forC 16 H 13 NNaO2 + ([M+Na)) + )274.0838,Found 274.0847.

[0041] Under the same conditions, compounds II-1 and VIII-1 were substituted, and all other operations were the same, to prepare compounds IV-1 to IV-9. The NMR data are shown in Table 1, and the corresponding spectra are shown in [Table 1]. Figures 1-6 .

[0042] The NMR data for the remaining compounds are shown in Table 1.

[0043] Table 1. NMR data of compounds IV-1 to IV-9

[0044]

[0045]

[0046]

[0047] Example 2: Study on the ferrophilic activity of compound IV

[0048] (1) Cleaning of utensils:

[0049] Wash and wrap the test tubes, petri dishes, conical flasks, pipette tips and other experimental equipment, sterilize them at 121℃ for 20 minutes by autoclaving, and then dry them in an oven for later use.

[0050] (2) Preparation of CAS culture medium:

[0051] ① Colorimetric solution A: Dissolve 0.013g of chromium azurite-S (CAS) in 10mL of distilled water, and mix it with 2mL of 1mmol / L FeCl3 solution (0.045g of FeCl3·6H2O, 0.1mL of concentrated hydrochloric acid, dissolved in 168mL of distilled water). Stir slowly, add HDTMA (hexadecyltrimethylammonium bromide) solution (0.016g of HDTMA dissolved in 8mL of distilled water) along the wall, mix well, sterilize, and cool to about 45℃ for later use.

[0052] ② 10×MM9 salt solution: Na2HPO4 6.0g, KH2PO4 0.3g, NaCl 0.5g, NH4Cl 1.0g, distilled water 100mL;

[0053] ③ Culture medium B: Take 20 mL of 10×MM9 salt solution, 6.04 g of PIPES (piperazine diethanol sulfonic acid), add 150 mL of distilled water, mix well, adjust the pH to about 7 with 5 mol / L NaOH, and finally add 3.6 g of agar powder. After sterilization, cool to about 45℃ for later use.

[0054] ④Nutritional components: Glucose 4.0g, KNO3 0.2g, MgSO4·7H2O 0.1g, NaCl 0.1g, KH2PO4 0.1g, FeSO4·7H2O 0.002g, sterilized for later use.

[0055] ⑤ Add nutrients to culture medium B, and finally add colorimetric solution A. After thorough mixing, this is the CAS culture medium.

[0056] (3) Detection of ferrophilic activity in samples:

[0057] Compounds IV1-IV9 were dissolved in DMSO to prepare a 20 mmol / L solution. 10 μL of this solution was added to 10 μL of CAS medium and incubated at room temperature. The presence of any color change was observed; if a color change was observed, the sample contained heptaphilic activity. Under the same conditions, DMSO was used as a control group, and three replicates were performed for each sample.

[0058] (4) Experimental conclusions:

[0059] Compared with the control group DMSO, the system of compounds IV-1 to IV-9 showed obvious color changes, see Figure 7 This demonstrates that compounds IV-1 to IV-9 possess ferrophilic activity.

Claims

1. A 3-hydroxyquinolin-2-one compound of formula (IV): ###0001### (IV) The 3-hydroxyquinolin-2-one compound of formula (IV) is one of the following: 。 2. A method for preparing the 3-hydroxyquinolin-2-one compound of formula (IV) according to claim 1, characterized in that, The preparation method comprises the following steps: (1) Compound (II) is reacted with compound (VIII) in sodium hydride and N,N-dimethylformamide to prepare compound (III) by increasing the temperature from 0 °C to room temperature; (2) Compound (III) is reacted with trimethylsilyldiazomethane and triethylamine in ethanol at room temperature to prepare compound (IV); R in formula (II) 1 , R in formula (VIII) 2 as shown in formula (IV) in claim 1; R in formula (III) 1 R in formula (II) 1 R in formula (III) 2 R in formula (VIII) 2 ; R in formula (IV) 1 R in formula (III) 1 R in formula (IV) 2 R in formula (III) 2 .

3. The production method according to claim 2, wherein Step (1) is performed as follows: compound (II) is dissolved in N,N-dimethylformamide at 0 °C, and stirred until completely dissolved, then sodium hydride is slowly added in batches, stirred for 10 min, then compound (VIII) is slowly added, increased to room temperature, stirred for 12 h, and the reaction is monitored to completion by TLC with a developing agent of petroleum ether: ethyl acetate at a volume ratio of 3:1; a conical flask is added with 3 times the amount of saturated ammonium chloride aqueous solution of N,N-dimethylformamide, and the reaction solution is added dropwise while stirring, then 7 times the amount of distilled water of N,N-dimethylformamide is added after the dropwise addition is completed, stirred for 1 h, then placed in a 5-8 °C refrigerator overnight, a large amount of solid product is precipitated, then filtered, the solid is completely dissolved with ethyl acetate, anhydrous sodium sulfate is added for drying, filtered, and the filtrate is concentrated under reduced pressure to complete dryness to obtain a solid product, which is compound (III).

4. The production method according to claim 2 or 3, characterized by, The molar ratio of compound (II) to sodium hydride is 1:1-1.5, the molar ratio of compound (II) to compound (VIII) is 1:1-1.5, and the volume of N,N-dimethylformamide is 1 mL / mmol based on the molar amount of compound (II).

5. The production method according to claim 2, wherein Step (2) is performed as follows: at room temperature, the reaction system is protected with nitrogen throughout, compound (III) and anhydrous ethanol are mixed and stirred uniformly, then triethylamine is added, stirred for 30 min, then trimethylsilyldiazomethane is added dropwise with a constant pressure dropping funnel, stirred for 15 h, a large amount of solid is precipitated, which is monitored by TLC with a developing agent of petroleum ether: ethyl acetate at a volume ratio of 3:1, after the reaction is completed, the solid is filtered, washed with anhydrous ethanol, and dried to obtain compound (IV).

6. The production method according to claim 5, wherein The molar ratio of compound (III) to triethylamine is 1:1.5-2.2, the molar ratio of compound (III) to trimethylsilyldiazomethane is 1:1-1.5, and the volume of anhydrous ethanol is 3-5 mL / mmol based on the molar amount of compound (III).

7. Use of the 3-hydroxyquinolin-2-one compound of claim 1 in the preparation of siderophores.

Images