Oligomeric surfactant, degradable broad-spectrum high-efficiency bactericide and preparation method and application thereof

Abstract

This invention discloses an oligomeric surfactant, a biodegradable broad-spectrum and highly efficient bactericide, and their preparation and application. The preparation method includes: mixing 18-nitro-2,3,5,6,8,9,11,12,14,15-decahydrobenzo[b][1,4,7,10,13,16]hexaoxane with a first catalyst and reacting under a hydrogen atmosphere to obtain an intermediate product; mixing the intermediate product with a second catalyst to obtain a crown ether head compound; and reacting the crown ether head compound with dodecylamine and / or heptadecanenonamine to obtain an oligomeric surfactant based on supramolecular assembly. This invention constructs two oligomeric surfactants C 12 N@BDHD and C 17‑9 N@BDHD was used to achieve highly efficient sterilization of bacteria such as Escherichia coli and Staphylococcus aureus by utilizing two oligomeric surfactants.

Description

Technical Field

[0001] This invention belongs to the field of bactericide technology, specifically relating to an oligomeric surfactant, a biodegradable broad-spectrum and highly efficient bactericide, and its preparation method and application. Background Technology

[0002] Surfactant molecules are a class of amphiphilic molecules containing both hydrophilic head groups and hydrophobic tail chains. They can significantly reduce the surface tension of solutions and have the ability to form assembled structures in solutions, and have been widely used in bactericides. Compared with traditional single-chain surfactant molecules, oligomeric surfactant molecules have lower minimum micelle concentrations, stronger assembly capabilities, and richer assembly behaviors. However, the covalent bonding in oligomeric surfactants makes their synthesis process complex and difficult to degrade, which can lead to their long-term persistence in the post-sterilization environment and ultimately cause bacterial resistance. Currently, oligomeric surfactants have the following problems: (1) Oligomeric surfactant synthesis is difficult and the process is complex; (2) Surfactant sterilization efficiency is low and the concentration used is high; (3) Long-term persistence of surfactants after sterilization leads to bacterial resistance; (4) The sterilization mechanism of surfactants is poorly understood. For example, patent CN109730067A discloses the application of a gemini quaternary ammonium salt bactericide system containing a naphthalene ring rigid linker in livestock and poultry sterilization. This system requires a small dosage and has good bactericidal effect; however, the surfactant structure in this patent is complex and difficult to degrade later. Patent CN115843795A discloses a method for constructing a surfactant bactericidal system using supramolecular chemistry; however, the composition of this patent is complex and the bactericidal efficiency is not high. Furthermore, the specific bactericidal mechanism of surfactants in the sterilization process is still relatively rudimentary. A thorough understanding of this mechanism is of guiding significance for surfactant molecular structure design and system construction. Summary of the Invention

[0003] The main objective of this invention is to provide an oligomeric surfactant, a biodegradable broad-spectrum and highly efficient bactericide, and its preparation method and application, so as to overcome the shortcomings of the prior art.

[0004] To achieve the aforementioned objectives, the technical solution adopted by this invention includes: This invention provides a method for preparing oligomeric surfactants based on supramolecular assembly, comprising: 18-nitro-2,3,5,6,8,9,11,12,14,15-decahydrobenzo[b][1,4,7,10,13,16]hexaoxane was mixed with a first catalyst and reacted under a hydrogen atmosphere to obtain an intermediate product. The intermediate product was mixed with a second catalyst to prepare a crown ether head group compound (denoted as: BDHD). And, the crown ether head group compound is reacted with dodecylamine (denoted as: C 12 N) and / or heptadecanine (denoted as: C) 17- The oligomeric surfactant based on supramolecular assembly was prepared by a 9N) mixed reaction.

[0005] The present invention also provides oligomeric surfactants based on supramolecular assembly prepared by the aforementioned preparation method.

[0006] This invention also provides a biodegradable broad-spectrum and highly efficient bactericide, comprising: an oligomeric surfactant based on supramolecular assembly prepared by the aforementioned preparation method.

[0007] The embodiments of the present invention also provide the application of the aforementioned oligomeric surfactants or biodegradable broad-spectrum and highly efficient bactericides based on supramolecular assembly in bacterial sterilization.

[0008] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The present invention prepares crown ether head group BDHD for non-covalent construction of oligomeric surfactant molecules; (2) This invention constructs two oligomeric surfactant molecules C 12 N@BDHD and C 17-9 N@BDHD; (3) This invention utilizes C 12 N@BDHD and C 17-9 N@BDHD achieves highly efficient sterilization of bacteria such as Escherichia coli and Staphylococcus aureus; (4) In this invention, the oligomeric surfactant utilizes the potassium ion responsiveness of non-covalent interactions to realize the molecular transformation of the surfactant before and after sterilization, fundamentally solving the problem of bacterial resistance. (5) This invention interprets the effect of surfactants on bacterial activity from multiple aspects such as bacterial structure, and clarifies the deep bactericidal mechanism of surfactant molecules. Attached Figure Description

[0009] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0010] Figure 1 This is a synthetic route diagram of the crown ether head compound BDHD in a typical embodiment of the present invention; Figure 2 This is C in a typical embodiment of the present invention. 12N@BDHD, C 17-9 A schematic diagram illustrating the combination of N@BDHD; Figures 3a-3b These are different concentrations of C in Example 1 of the present invention. 12 N@BDHD solution, C 17-9 Surface tension diagram of N@BDHD solution; Figures 4a-4b It is C in Embodiment 1 of the present invention 12 N@BDHD solution, C 17-9 Cryo-transmission electron microscopy image of N@BDHD solution; Figure 5 It is C in Embodiment 1 of the present invention 12 N@BDHD and C 17-9 Cell morphology of bacteria and fungi before and after N@BDHD treatment; Figure 6 It is C in Embodiment 1 of the present invention 12 N@BDHD and C 17-9 Image showing the bacterial resistance results after N@BDHD treatment; Figure 7 It is C in Embodiment 1 of the present invention 12 N@BDHD and C 17-9 N@BDHD responsive behavior outcome graph; Figures 8a-8b This is a diagram showing the results of the wheat seed germination test in the biocompatibility experiment of Example 1 of this invention; Figures 9a-9b This is a graph showing the results of the acute toxicity evaluation of zebrafish in the biocompatibility experiment of Example 1 of this invention; Figures 10a-10b This is a graph showing the results of the pesticide solubilization experiment in Example 1 of this invention. Detailed Implementation

[0011] In view of the deficiencies of the prior art, the inventors of this case, through long-term research and extensive practice, have proposed the technical solution of this invention. The technical solution of this invention will be clearly and completely described below. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0012] Specifically, as one aspect of the technical solution of this invention, a method for preparing an oligomeric surfactant based on supramolecular assembly includes: 18-nitro-2,3,5,6,8,9,11,12,14,15-decahydrobenzo[b][1,4,7,10,13,16]hexaoxane was mixed with a first catalyst and reacted under a hydrogen atmosphere to obtain an intermediate product. The intermediate product was mixed with a second catalyst to prepare a crown ether head group compound (denoted as: BDHD). And, the crown ether head group compound is reacted with dodecylamine (denoted as: C 12 N) and / or heptadecanine (denoted as: C) 17- The oligomeric surfactant based on supramolecular assembly was prepared by a 9N) mixed reaction.

[0013] In some preferred embodiments, the preparation method specifically includes: mixing 18-nitro-2,3,5,6,8,9,11,12,14,15-decahydrobenzo[b][1,4,7,10,13,16]hexaoxane and a first catalyst in a first solvent, then reacting the mixture with shaking at room temperature under a hydrogen pressure of 45 psi for 5 to 5.5 h, followed by filtration and purification to obtain the intermediate product.

[0014] Further, the mass ratio of 18-nitro-2,3,5,6,8,9,11,12,14,15-decahydrobenzo[b][1,4,7,10,13,16]hexaoxane to the first catalyst is 5:1.

[0015] Furthermore, the first catalyst comprises, but is not limited to, 5 wt% palladium / carbon catalyst.

[0016] Furthermore, the first solvent includes, but is not limited to, methanol.

[0017] In some preferred embodiments, the preparation method specifically includes: dissolving the intermediate product in a second solvent, adding a second catalyst and stirring the reaction at room temperature for 7 hours, and then filtering, rotary evaporating and purifying to obtain the crown ether head compound.

[0018] Furthermore, the molar ratio of the intermediate product to the second catalyst is 1:2.

[0019] Furthermore, the second catalyst comprises a mixture of n-butylmagnesium bromide and copper chloride, wherein the molar ratio of n-butylmagnesium bromide to copper chloride is 1~1.5:1.

[0020] Furthermore, the second solvent includes, but is not limited to, dichloromethane.

[0021] In some preferred embodiments, the synthetic route of the crown ether head group compound (denoted as: BDHD) is as follows: Figure 1 As shown.

[0022] In some preferred embodiments, the preparation method specifically includes: mixing the crown ether head group compound with an aqueous solution of dodecylamine and / or an aqueous solution of heptadecanine-nonamine and heating and sonicating to completely dissolve it, to obtain a crown ether head group compound / dodecylamine solution (denoted as: C). 12 N@BDHD), crown ether head group compound / heptadecanenonamine solution (denoted as: C 17-9 N@BDHD) or crown ether head group compound / dodecylamine / heptadecanenonamine solution (denoted as: C 12 N / C 17-9 N@BDHD) Crown ether head group compound / C 12 N / C 17-9 N solution, i.e., oligomeric surfactant solution.

[0023] Furthermore, the molar ratio of the ether-headed compound to dodecylamine and / or heptadecanoamine is 1:2 to 8.

[0024] Furthermore, the concentration of the oligomeric surfactant solution is 0.001 mM to 50 mM.

[0025] In some preferred embodiments, the crown ether head group compound / C 12 N solution (denoted as: C) 12 N@BDHD), crown ether head group compound / C 17-9 N solution (denoted as: C) 17-9 A schematic diagram of the combination of N@BDHD is shown below. Figure 2 As shown, amine molecules can be interconnected with crown ether heads, while potassium ions have a stronger bond with crown ether heads, which can replace the amine in the combined structure.

[0026] Another aspect of the present invention provides an oligomeric surfactant based on supramolecular assembly prepared by the aforementioned preparation method.

[0027] Another aspect of the present invention provides a biodegradable broad-spectrum and highly efficient bactericide, comprising: an oligomeric surfactant based on supramolecular assembly prepared by the aforementioned preparation method.

[0028] Another aspect of the present invention provides the application of the aforementioned supramolecular assembly-based oligomeric surfactants or degradable broad-spectrum and highly efficient bactericides in bacterial sterilization.

[0029] Furthermore, the bacteria include Escherichia coli and / or Staphylococcus aureus.

[0030] The technical solution of the present invention will be further described in detail below with reference to several preferred embodiments and accompanying drawings. This embodiment is implemented on the premise of the technical solution of the invention, and provides detailed implementation methods and specific operation processes. However, the protection scope of the present invention is not limited to the following embodiments.

[0031] Unless otherwise specified, the experimental materials used in the examples below can be purchased from conventional biochemical reagent companies.

[0032] Example 1 The preparation method of crown-head BDHD is as follows: 18-nitro-2,3,5,6,8,9,11,12,14,15-decahydrobenzo[b][1,4,7,10,13,16]hexaoxane (5 g) and 5% palladium / carbon (1 g) were mixed in 15 mL of methanol and shaken at 45 psi hydrogen pressure for 5 hours at room temperature. The catalyst was removed by filtration, and the filtrate was rotary evaporated to obtain a crude product. The crude product was purified by ethanol and ethyl acetate. The purified product was dissolved in 20 mL of dichloromethane, and 2 equivalents of n-butylmagnesium bromide / copper chloride mixture were added as a catalyst. The mixture was stirred at room temperature for 7 hours, and the catalyst was removed by filtration. The filtrate was rotary evaporated to obtain a crude product. The crude product was purified by recrystallization from ethanol and ethyl acetate to obtain the final yellow product, pure BDHD (2 g).

[0033] Structural characterization of pure BDHD: 1 ¹H NMR (DMSO, 400 MHz, ppm): δ 7.50 (d, 2H, C-CH=CH), 7.43 (s, 2H, C-CH=C), 7.13 (d, 2H, C-CH=CH), 4.18 (s, 4H, O-CH₂-C), 3.80 (s, 4H, C-CH₂-O), 3.51 (t, 12H, C-CH₂-O); Elemental Analysis: N content 3.56%, C content 57.68%, H content 7.15%.

[0034] C 12 N@BDHD and C 17-9 N@BDHD system preparation method: Weigh a certain mass of BDHD powder into C 12 N or C 17-9 In an aqueous solution of N, the surfactant is heated and sonicated until completely dissolved, and the resulting clear yellow solution is used as the mother liquor. Subsequently, the mother liquor is diluted three times with water to obtain C solutions with different surfactant concentrations. 12 N@BDHD solution (BDHD:C 12 N=0:1, 1:2, 1:5) and C 17-9 N@BDHD solution (BDHD:C 17-9 N = 0:1, 1:2, 1:5).

[0035] The above-mentioned different concentrations of C 12 N@BDHD solution, C 17-9 The surface tension diagram of N@BDHD solution is as follows: Figure 3a , Figure 3b As shown, C 12 N@BDHD solution, C 17-9 N@BDHD solution compared to C alone 12 N and C 17-9 The surface tension and critical micelle concentration of the N solution decreased significantly, with the critical micelle concentration decreasing from 2 mM to 0.01 mM.

[0036] The above C 12 N@BDHD solution (BDHD:C 12 N=0:1, 1:2, 1:5) and C 17-9 N@BDHD solution (BDHD:C 17-9 Cryo-transmission electron microscopy images for N=0:1, 1:2, 1:5 are shown below. Figure 4a , Figure 4b As shown.

[0037] (1) The method for the bactericidal experiment of oligomeric surfactants is as follows: Escherichia coli and Staphylococcus aureus strains were cultured in liquid LB medium at 37°C. The well-grown bacterial stock solution was diluted to 1.0 × 10⁻⁶. 5 CFU / mL concentration, take 5 μL of bacterial culture and add it to 1 mL of 0-0.1 mM solution at a ratio of 1~8:0~1. 12 N@BDHD, C 17-9 After incubating the N@BDHD solution in a shaker at 37°C for 2 hours, 100 μL of the solution was evenly added to a 9 cm diameter petri dish containing solid LB medium. Five glass beads were added, and the dish was shaken evenly back and forth and side to side 20 times. The glass beads were then removed and the dish was sealed. The petri dish was then placed in a 37°C constant temperature and humidity incubator for 18 hours, and the data were recorded using an optical camera. Each measurement was performed at least three times.

[0038] C 12 N@BDHD and C 17-9 The bactericidal ability of the N@BDHD system is shown in Tables 1 and 2. It can be seen that the minimum inhibitory concentration of the oligomeric surfactant against Escherichia coli reached 0.37 mg / L.

[0039] Table 1. Sterilization efficiency against Escherichia coli

[0040] Table 2. Bactericidal efficiency against Staphylococcus aureus

[0041] (2) The experimental procedure for the sterilization mechanism is as follows: Scanning electron microscopy: *Escherichia coli* and *Staphylococcus aureus* strains were cultured in liquid LB medium at 37 °C for growth. The bacterial stock solution was then... 12 N@BDHD and C 17-9 N@BDHD solution was mixed, and the bacterial concentration was diluted to 1.0 × 10⁻⁶ after mixing. 8 CFU / mL, C 12 N@BDHD and C 17-9 The N@BDHD concentration was twice the MIC value, and the samples were incubated in a shaker at 37 °C for 1 h. Three water solutions were used as experimental controls. The samples were then placed on glass slides coated with 0.1% polylysine and allowed to adhere for at least 30 minutes, followed by fixation with 2.0% glutaraldehyde solution at 4 °C for at least 24 h. Subsequently, the samples were dehydrated with a series of ethanol solutions of different volume fractions (50%, 70%, 90%, 95%, 100%). After dehydration, a 50 nm gold-palladium alloy was coated using a Hummer VI sputtering system (Anatech USA), and imaging was performed at 30 kV on a FEI Quanta 200 SEM (S-4800, Hitachi, Japan) running in high vacuum mode.

[0042] C 12 N@BDHD and C 17-9 Bacterial and fungal cell morphology before and after N@BDHD treatment, as shown in the figure. Figure 5 As shown in the scanning electron microscope image, it can be clearly seen that after C 12 N@BDHD and C 17-9 The bacterial cell membranes of N@BDHD-treated bacteria showed obvious rupture, the cells were dented and shrunken, and the cell fluid leaked out.

[0043] (3) The experimental procedure for bacterial resistance is as follows: Escherichia coli is cultured in liquid LB medium at 37 °C. The bacterial stock solution is then mixed with C... 12 N@BDHD and C 17-9The N@BDHD solution was mixed, and the surfactant concentration was controlled at half of the corresponding minimum inhibitory concentration. After shaking in a shaker at 37°C for 2 hours, 100 μL of the solution was taken out and evenly added to a 9 cm diameter petri dish containing solid LB medium. Five glass beads were added, and the dish was shaken evenly back and forth and side to side 20 times. The glass beads were removed and sealed. The petri dish was then placed in a 37°C humidity incubator for 18 hours, and the results were recorded using an optical camera. Each measurement was performed at least three times. Subsequently, bacterial colonies with similar growth states were selected from the corresponding bacteria and placed in liquid LB medium for subculturing. The above operation was repeated after culturing until the bactericidal effect significantly deviated by 50%.

[0044] Figure 6 C 12 N@BDHD and C 17-9 The graph showing the bacterial resistance results after N@BDHD treatment clearly indicates that after several generations of passage, C... 12 N@BDHD and C 17-9 Even after N@BDHD treatment, approximately 50% of the bactericidal ability is still retained.

[0045] (4) responsiveness UV Absorption CnN@BDHD Solution UV absorption value C 12 N@BDHD and C 17-9 The N@BDHD was performed using a Shimadzu UV-2800 UV-Vis spectrophotometer. Under constant temperature conditions of 25.0 ± 0.01°C, different pH, T, and UV / Vis light mixtures were measured within the range of 300–500 nm. Milli-Q water absorption was used as the controller to calibrate all measurements.

[0046] Responsive behavior of oligomeric surfactants, such as Figure 7 As shown, the ultraviolet absorption changes significantly with changes in temperature, pH, and ultraviolet light, which is due to the cis-trans isomerism of the azo structure.

[0047] (5) Biocompatibility test Wheat seed germination test Wheat seeds were first soaked in water for 24 hours, and then, at room temperature, in groups of 10, were transferred to 10 mL of 10 mL Petri dishes (9 cm in diameter). 12 N, C 17-9 N, C 12 N@BDHD and C 17-9 The solution was prepared using N@BDHD (0.1 mM). Root and shoot lengths were recorded after 72 hours, with each indicator measured at least three times. Results are as follows: Figures 8a-8b As shown, after C 12 N@BDHD and C17-9 The root length and shoot length of wheat seeds treated with N@BDHD were higher than those of the blank control group.

[0048] Acute toxicity assessment of zebrafish Using 5-6 month old wild-type male adult zebrafish as test material, the study of C 12 N, C 17-9 N, C 12 N@BDHD and C 17-9 The acute toxicity of N@BDHD was observed at concentrations ranging from 0.001 to 0.01 mM. Healthy zebrafish (n=10 per group) were placed in a surfactant solution, with zebrafish in deionized water serving as a control group. The survival status of the zebrafish was recorded using a camera at 24, 48, 72, and 96 h. The zebrafish were not fed during the experiment. Results are as follows: Figures 9a-9b As shown, the addition of crown ether head groups significantly reduces zebrafish toxicity in the system, with a survival rate of 100%.

[0049] The oligomeric surfactant system in this invention has excellent biocompatibility.

[0050] (6) Pesticide solubilization experiment Add each 1.0% (10 mg / mL) sample of the pesticide sulfadiazine to C 12 N@BDHD and / or C 17-9 N@BDHD was stirred at different pH values ​​for 48 h, centrifuged at 10000 rpm for 10 min, the supernatant was removed, and the solution was diluted to a specific factor. The concentration of sulfadiazine in solution was analyzed by comparing the UV absorption spectrum with a standard curve. The solubilizing ability of oligomeric surfactants for sulfadiazine was as follows: Figures 10a-10b As shown, sulfadiazine at C 12 N@BDHD and / or C 17-9 The solubility of N@BDHD is 8-10 times that of its solubility in pure water.

[0051] In addition, the inventors of this case also conducted experiments with other raw materials, process operations, and process conditions described in this specification, referring to the aforementioned embodiments, and obtained relatively ideal results in all cases.

[0052] It should be understood that the technical solutions of the present invention are not limited to the specific embodiments described above. Any technical modifications made to the technical solutions of the present invention without departing from the spirit and scope of the claims are within the scope of protection of the present invention.

Claims

1. A method for preparing oligomeric surfactants based on supramolecular assembly, characterized in that, include: 18-nitro-2,3,5,6,8,9,11,12,14,15-decahydrobenzo[b][1,4,7,10,13,16]hexaoxane was mixed with a first catalyst and reacted under a hydrogen atmosphere to obtain an intermediate product. The intermediate product was mixed with a second catalyst and reacted to obtain a crown ether head group compound. Furthermore, the crown ether head group compound is mixed and reacted with dodecylamine and / or heptadecanine to prepare an oligomeric surfactant based on supramolecular assembly.

2. The preparation method according to claim 1, characterized in that, Specifically, it includes: 18-nitro-2,3,5,6,8,9,11,12,14,15-decahydrobenzo[b][1,4,7,10,13,16]hexaoxane and the first catalyst were mixed in the first solvent, and then the mixture was reacted at room temperature with shaking at 45 psi hydrogen pressure for 5 to 5.5 h. The mixture was then filtered and purified to obtain the intermediate product.

3. The preparation method according to claim 2, characterized in that: The mass ratio of 18-nitro-2,3,5,6,8,9,11,12,14,15-decahydrobenzo[b][1,4,7,10,13,16]hexaoxane to the first catalyst is 5:1; And / or, the first catalyst comprises 5 wt% palladium / carbon catalyst; And / or, the first solvent includes methanol.

4. The preparation method according to claim 1, characterized in that, Specifically, it includes: The intermediate product was dissolved in a second solvent, a second catalyst was added, and the mixture was stirred at room temperature for 7 hours. The mixture was then filtered, rotary evaporated, and purified to obtain the crown ether head compound.

5. The preparation method according to claim 4, characterized in that: The molar ratio of the intermediate product to the second catalyst is 1:2; And / or, the second catalyst comprises a mixture of n-butylmagnesium bromide and copper chloride, wherein the molar ratio of n-butylmagnesium bromide to copper chloride is 1 to 1.5:1; And / or, the second solvent includes dichloromethane.

6. The preparation method according to claim 1, characterized in that, Specifically, it includes: The crown ether head group compound is mixed with an aqueous solution of dodecylamine and / or an aqueous solution of heptadecanenonamine and heated and sonicated to completely dissolve it, thereby obtaining a crown ether head group compound / dodecylamine solution, a crown ether head group compound / heptadecanenonamine solution, or a crown ether head group compound / dodecylamine / heptadecanenonamine solution, i.e., an oligomeric surfactant solution.

7. The preparation method according to claim 6, characterized in that: The molar ratio of the ether head compound to dodecylamine and / or heptadecanoamine is 1:2~8; And / or, the concentration of the oligomeric surfactant solution is 0.001 mM to 50 mM.

8. An oligomeric surfactant based on supramolecular assembly prepared by any one of claims 1-7.

9. A biodegradable, broad-spectrum, highly effective bactericide, characterized in that, include: The oligomeric surfactant based on supramolecular assembly prepared by the preparation method of claim 8.

10. The application of the oligomeric surfactant based on supramolecular assembly as described in claim 8 or the biodegradable broad-spectrum and highly efficient bactericide as described in claim 9 in bacterial sterilization; preferably, the bacteria include Escherichia coli and / or Staphylococcus aureus.

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