A photodynamic bactericide, a preparation method thereof and application thereof in fruit and vegetable preservation

Abstract

The present application belongs to the technical field of fruit and vegetable preservation. More specifically, it relates to a kind of photodynamic bactericide and its preparation method and application in fruit and vegetable preservation. The present application provides a kind of compound, which can produce active oxygen under visible light irradiation, showing excellent photodynamic bactericidal performance, and can be used as a kind of photodynamic bactericide. The compound of the present application has a clear structure, a simple synthesis route, good repeatability and potential for large-scale production. The compound of the present application is applied to the field of fruit and vegetable preservation, and can effectively inhibit the growth of pathogenic bacteria on the surface of fruit under light conditions, prolong the storage period of fruit and vegetable. In addition, the compound shows good stability when used in combination with food contact materials, and is not easy to migrate from the coating or packaging material to the inside of the fruit, with high safety. The present application provides a kind of green, efficient and safe compound, which can be used as a kind of photodynamic bactericide and applied to fruit and vegetable preservation, and has good application prospect and value.

Description

Technical Field

[0001] This invention belongs to the field of fruit and vegetable preservation technology. More specifically, it relates to a photodynamic bactericide, its preparation method, and its application in fruit and vegetable preservation. Background Technology

[0002] In agricultural production and distribution, fruits and vegetables are highly susceptible to infection by various pathogenic microorganisms. This can cause symptoms such as rot, discoloration, softening, and black spots, significantly reducing their commercial value and edible quality, and may also pose food safety risks. For example, mangoes are susceptible to Xanthomonas spp. (…) during their growth period. Xanthomonas Infection with Xanthomonas spp. can cause bacterial black spot disease in mangoes, affecting leaves, branches, inflorescences, and fruits. This not only significantly reduces mango yield but also severely impacts fruit appearance, quality, and market value. More concerningly, the disease can continue to develop during harvesting, storage, transportation, and sales, further exacerbating economic losses. Furthermore, Xanthomonas spp. not only infect mangoes but also cause various other bacterial diseases in fruits and vegetables, such as black rot in cruciferous vegetables, black spot disease in walnuts, bacterial spot disease in tomatoes and peppers, and bacterial wilt disease in bananas. These diseases are characterized by rapid spread, high damage, and difficulty in control, seriously threatening the safe production and stability of the fruit and vegetable industry.

[0003] For the long-term storage and transportation of fruits and vegetables, effective sterilization or bacteriostatic treatment is crucial to ensuring their quality and extending shelf life. Currently used preservation technologies include radiation storage, coating preservation, and chemical sterilization. While radiation treatment can effectively kill pathogens, it may have some negative impact on the quality of fruits and vegetables. Coating preservation inhibits pathogen growth by forming an isolation layer on the surface of fruits and vegetables, but its bacteriostatic effect is limited. Although chemical sterilization is highly efficient, the commonly used systemic fungicides pose a risk of penetrating the fruit pulp; despite their low toxicity, this still raises certain food safety concerns.

[0004] In conclusion, developing a novel, safe, environmentally friendly, and highly efficient fungicide for post-harvest preservation of fruits and vegetables is of significant practical importance and has broad application prospects. Summary of the Invention

[0005] The present invention aims to overcome the shortcomings of the prior art and provide a compound that can efficiently generate reactive oxygen species (ROS) under visible light irradiation, exhibiting excellent photodynamic bactericidal performance, and can be used as a photodynamic bactericide.

[0006] The first objective of this invention is to provide a compound.

[0007] A second objective of this invention is to provide a method for preparing the above-mentioned compound.

[0008] A third object of the present application is to provide the use of the above-mentioned compound in antibiosis.

[0009] A fourth object of the present application is to provide the use of the above-mentioned compound in food preservation.

[0010] A fifth object of the present application is to provide the use of the above-mentioned compound in the prevention and treatment of bacterial leaf spot.

[0011] A sixth object of the present application is to provide an antibacterial product.

[0012] The above-mentioned objects of the present application are achieved by the following technical solutions.

[0013] The present application provides a compound, the structural formula of which is shown in formula (I):

[0014]

[0015] Formula (I).

[0016] The present application provides a preparation method of the above-mentioned compound, which uses 2,3-bis(4-bromophenyl)-2-butadienenitrile and (4-(1,2,2-triphenylvinyl)phenyl)boronic acid as raw materials, and performs coupling reaction under the conditions of alkalinity and inert gas protection in the presence of a palladium catalyst to obtain an intermediate compound; the intermediate compound is subjected to coupling reaction again with bis(4-methoxyphenyl)amine in the presence of a palladium catalyst to obtain the compound shown in formula (I).

[0017] More specifically, the preparation method of the above-mentioned compound comprises the following steps:

[0018] Step A: 2,3-bis(4-bromophenyl)-2-butadienenitrile, (4-(1,2,2-triphenylvinyl)phenyl)boronic acid, potassium carbonate and a palladium catalyst are placed in an aprotic solvent, and are reacted under inert gas protection at 60-70°C; after the reaction is completed, the solid reaction product is recovered to obtain an intermediate compound;

[0019] Step B: the intermediate compound obtained in step A, bis(4-methoxyphenyl)amine, potassium carbonate and a palladium catalyst are placed in toluene solvent, and are reacted under inert gas protection at 85-95°C; after the reaction is completed, the solid reaction product is recovered to obtain the compound shown in formula (I).

[0020] As an alternative embodiment, the inert gas is nitrogen.

[0021] As an alternative embodiment, the aprotic solvent comprises acetonitrile and tetrahydrofuran (preferably tetrahydrofuran).

[0022] As an alternative embodiment, the palladium catalyst is any one of tris(dibenzylideneacetone)dipalladium, bis(dibenzylideneacetone)palladium, tetrakis(triphenylphosphine)palladium.

[0023] As an alternative embodiment, the palladium catalyst is tetrakis(triphenylphosphine)palladium.

[0024] As an alternative embodiment, the reaction temperature in step A is 65 °C.

[0025] As an alternative embodiment, the reaction temperature in step B is 90 °C.

[0026] As an alternative embodiment, in step A of the above preparation method, the mass ratio of 2,3-bis(4-bromophenyl)-2-butadienenitrile, (4-(1,2,2-triphenylvinyl)phenyl)boronic acid, potassium carbonate, and palladium catalyst is 1: (1-2): (8-12): (0.01-0.03).

[0027] As an alternative embodiment, in step A of the above preparation method, the mass ratio of 2,3-bis(4-bromophenyl)-2-butadienenitrile, (4-(1,2,2-triphenylvinyl)phenyl)boronic acid, potassium carbonate, and palladium catalyst is 1:1:10:0.02.

[0028] As an alternative embodiment, in step A of the above preparation method, the final concentration of 2,3-bis(4-bromophenyl)-2-butadienenitrile is 30-50 μmol / mL (preferably 40 μmol / mL), the final concentration of (4-(1,2,2-triphenylvinyl)phenyl)boronic acid is 30-50 μmol / mL (preferably 40 μmol / mL), the final concentration of potassium carbonate is 300-500 μmol / mL (preferably 400 μmol / mL), and the final concentration of palladium catalyst is 0.5-1 μmol / mL (preferably 0.8 μmol / mL).

[0029] As an alternative embodiment, in step B of the above preparation method, the mass ratio of intermediate compound, bis(4-methoxyphenyl)amine, potassium carbonate, and palladium catalyst is 1: (1-2): (8-12): (0.05-0.15).

[0030] As an alternative embodiment, in step B of the above preparation method, the mass ratio of intermediate compound, bis(4-methoxyphenyl)amine, potassium carbonate, and palladium catalyst is 1:1:10:0.1.

[0031] As an alternative embodiment, in the above preparation method, the final concentration of the intermediate compound in step B is 30-50 μmol / mL (preferably 40 μmol / mL), the final concentration of bis(4-methoxyphenyl)amine is 30-50 μmol / mL (preferably 40 μmol / mL), the final concentration of potassium carbonate is 300-500 μmol / mL (preferably 400 μmol / mL), and the final concentration of the palladium catalyst is 3-5 μmol / mL (preferably 4 μmol / mL).

[0032] As an alternative embodiment, in the above preparation method, the reaction time in step A and step B is 20-28 hours.

[0033] As an alternative embodiment, in the above preparation method, the reaction time in step A and step B is 24 hours.

[0034] As an alternative embodiment, the method for recovering the solid reactant in step A is: after the reaction solution is cooled, pour it into an equal volume of water to obtain a mixed solution; extract, dry, filter the mixed solution, take the filtrate to perform rotary evaporation under reduced pressure, and then perform silica gel column chromatography.

[0035] As an alternative embodiment, the extractant used for extraction is dichloromethane.

[0036] As an alternative embodiment, the drying is to wash the extracted organic phase with saturated sodium chloride water and then dry it with anhydrous magnesium sulfate.

[0037] As an alternative embodiment, the mobile phase of the silica gel column chromatography is a mixed solution of n-hexane and dichloromethane.

[0038] As an alternative embodiment, the silica gel column chromatography is gradient elution, and the elution time is 20-40 minutes (preferably 30 minutes).

[0039] As an alternative embodiment, the silica gel column chromatography is gradient elution with n-hexane:dichloromethane in a volume ratio of 5:1 to 2:1.

[0040] As an alternative embodiment, the method for recovering the solid reactant in step B is: after the reaction solution is cooled, perform rotary evaporation under reduced pressure, then perform extraction, drying, filtration, take the filtrate to perform rotary evaporation under reduced pressure, and then perform silica gel column chromatography.

[0041] As an alternative embodiment, the extractant used for extraction is dichloromethane and water, and the volume ratio of dichloromethane to water is 3:1.

[0042] As an alternative embodiment, the drying is carried out by washing the extracted organic phase with saturated sodium chloride water and drying with anhydrous magnesium sulfate.

[0043] The present application provides the above-mentioned compound which can generate reactive oxygen species (ROS) under visible light irradiation, exhibits excellent photodynamic bactericidal performance, and can effectively inhibit the growth of pathogenic bacteria on the surface of fruits under light conditions by constructing a functional coating or an antibacterial preservative bag, thereby preventing the occurrence of bacterial black spot, and can be applied in fruit and vegetable preservation to prolong the storage period of fruits and vegetables.

[0044] The above-mentioned compound is applied in antibacterial.

[0045] The above-mentioned compound is applied in the preparation of antibacterial products.

[0046] Specifically, the antibacterial is against Xanthomonas (Xanthomonas) bacteria. Xanthomonas ) bacteria.

[0047] The above-mentioned compound is applied in food preservation.

[0048] The above-mentioned compound is applied in the preparation of food preservation products.

[0049] As an alternative embodiment, the food is fruits and vegetables.

[0050] As an alternative embodiment, the fruits and vegetables are mangoes.

[0051] The above-mentioned compound is applied in the prevention and treatment of bacterial black spot.

[0052] The above-mentioned compound is applied in the preparation of products for preventing and treating bacterial black spot.

[0053] Specifically, the bacterial black spot is black spot caused by Xanthomonas (Xanthomonas) bacteria. Xanthomonas ) bacteria.

[0054] Specifically, the Xanthomonas bacteria is Xanthomonas campestris (Xanthomonas campestris) or Xanthomonas citri (Xanthomonas citri). Xanthomonas campestris Xanthomonas citri

[0055] The present application also provides an antibacterial product containing the above-mentioned compound.

[0056] Specifically, the antibacterial product includes bactericides, antibacterial preservative coatings or antibacterial preservative bags.

[0057] ​​Specifically, the bactericide is a kind of photodynamic bactericide. The photodynamic bactericide is a kind of compound that can produce active oxygen under light. The active oxygen produced by the photodynamic bactericide has extremely strong oxidation ability, which can destroy the cell structure and biological macromolecules (such as proteins, lipids, DNA) of microorganisms such as bacteria, fungi and viruses, thereby realizing high-efficiency bactericidal effect. In recent years, the photodynamic bactericide has been widely studied for treating infectious diseases, and has become a promising alternative solution especially in the context of the increasingly serious problem of antibiotic resistance.

[0058] As an alternative embodiment, the bactericide is a Xanthomonas campestris bactericide or a Xanthomonas citri bactericide.

[0059] As a specific solution, when the antibacterial product is an antibacterial fresh-keeping coating, the preparation method of the antibacterial fresh-keeping coating is: adding glycerol into a polyvinyl alcohol solution, then adding the above-mentioned compound, and uniformly mixing to obtain a film solution, and then preparing a coating from the film solution to obtain the antibacterial fresh-keeping coating.

[0060] As an alternative embodiment, in the preparation method of the above-mentioned antibacterial fresh-keeping coating, the final concentration of polyvinyl alcohol is 10-30 mg / mL, the final concentration of glycerol is 1-3 mg / mL, and the final concentration of the above-mentioned compound is 8-12 μmol / L.

[0061] As an alternative embodiment, in the preparation method of the above-mentioned antibacterial fresh-keeping coating, the solvent of the polyvinyl alcohol solution is water.

[0062] As a specific solution, when the antibacterial product is an antibacterial fresh-keeping bag, the preparation method of the antibacterial fresh-keeping bag is: adding polyethylene glycol into polylactic acid, uniformly mixing, then adding the above-mentioned compound after cooling to obtain a mixed solution; using a solution casting method to prepare a film from the mixed solution, and then taking two films to be superimposed and heat-sealing three edges to obtain the antibacterial fresh-keeping bag.

[0063] As an alternative embodiment, in the preparation method of the antibacterial fresh-keeping bag, the final concentration of polylactic acid is 20-40 mg / mL, the final concentration of polyethylene glycol is 1-2 mg / mL, and the final concentration of the above-mentioned compound is 8-12 μmol / L.

[0064] As an alternative embodiment, in the preparation method of the antibacterial fresh-keeping bag, the solvent of the polylactic acid solution is dichloromethane.

[0065] The present application has the following beneficial effects:

[0066] The present application provides a novel compound, which can efficiently produce active oxygen (ROS) under visible light irradiation and exhibit excellent photodynamic bactericidal performance. Experimental results show that it has high bactericidal activity against Xanthomonas (Xanthomonas campestris and Xanthomonas citri) and can effectively inhibit the growth of Xanthomonas. XanthomonasThe pathogenic bacteria have rapid and efficient killing effect, and are suitable for preventing and controlling related diseases caused by Xanthomonas pathogenic bacteria.

[0067] The compound has good reproducibility and industrial application prospect as a photodynamic bactericide. When the compound is used in the field of fruit and vegetable preservation, the antibacterial function can be realized by constructing a functional antibacterial coating or preparing a photodynamic antibacterial preservation bag and the like. Under the condition of light, the compound can continuously generate active oxygen, effectively inhibit the growth and reproduction of pathogenic bacteria on the surface of fruits, significantly prolong the storage period of fruits and vegetables, and improve the shelf life and commodity value of products.

[0068] In addition, the compound has good environmental friendliness and food safety, and exhibits excellent stability in food contact materials, and is not easy to migrate from the packaging material or coating to the inside of the fruit, thereby avoiding the influence on the texture, flavor and food safety of the fruit, and greatly improving the application safety and feasibility in the field of food preservation. The present application provides a green, efficient and safe photodynamic bactericide and its application in fruit and vegetable preservation, which has broad market prospect and practical promotion value. BRIEF DESCRIPTION OF DRAWINGS

[0069] Figure 1 The rate of generating active oxygen to degrade ABDA under white light irradiation of the target compound (I).

[0070] Figure 2 The bacterial survival rate of the target compound (I) mixed with Xanthomonas campestris and Xanthomonas citri under sunlight lamp irradiation for different time.

[0071] Figure 3 The appearance photograph of the mango coated with the target compound (I) after being placed in the room for one week; (a) is the appearance photograph of the blank control group of mango; (b) is the appearance photograph of the mango treated by the coating of the target compound (I). DETAILED DESCRIPTION

[0072] The present application will be further described below in combination with the drawings and specific examples, but the examples do not limit the present application in any form. Unless otherwise specified, the reagents, methods and devices used in the present application are conventional reagents, methods and devices in the technical field.

[0073] Unless otherwise specified, the reagents and materials used in the following examples are commercially available.

[0074] 2,3-bis(4-bromophenyl)-2-butadienenitrile, CAS No.: 82193-93-9, structural formula: .

[0075] (4-(1,2,2-triphenylvinyl)phenyl)boronic acid, CAS number: 1227040-87-0, structural formula:

[0076] .

[0077] Tetra(triphenylphosphine)palladium, CAS No.: 14221-01-3, structural formula:

[0078] .

[0079] bis(4-methoxyphenyl)amine, CAS number: 101-70-2, structural formula:

[0080] .

[0081] Xanthomonas aeruginosa ( Xanthomonas campestris Accession number ACCC 10048 originates from the China Agricultural Microbial Culture Collection Center (www.accc.org.cn).

[0082] Xanthomonas citrus ( Xanthomonas citri The strain (CCTCC FB 2023476) is from the China Center for Type Culture Collection, with the accession number CCTCC FB 2023476.

[0083] The singlet oxygen probe 9,10-anthrayl-bis(methylene)dimalonic acid (ABDA) was purchased from Beijing Bailingwei Technology Co., Ltd., product number 618607.

[0084] The silica gel used in the silica gel column chromatography was purchased from the Qingdao Ocean Chemical Plant branch, with product number 0180126.

[0085] Example 1 Preparation of target compound (I)

[0086] The structural formula of the target compound 2-(4-(bis(4-methoxyphenyl)amino)phenyl)-3-(4'-(1,2,2-triphenylvinyl)-[1,1'-biphenyl]-4-yl)nicotinonitrile is shown in formula (I), and is denoted as target compound (I).

[0087] .

[0088] Its preparation method includes the following two steps:

[0089] Step A: 4.0 mmol of 2,3-bis(4-bromophenyl)-2-butylenitrile, 4.0 mmol of (4-(1,2,2-triphenylvinyl)phenyl)boronic acid, 40 mmol of potassium carbonate, 0.08 mmol of tetrakis(triphenylphosphine)palladium were added to 100 mL of tetrahydrofuran solvent, heated to reflux at 60°C under nitrogen atmosphere for 24 hours, after the reaction was completed, the reaction solution was cooled to room temperature, poured into 100 mL of water, extracted with dichloromethane, the organic phase after extraction was washed with saturated sodium chloride water and dried over anhydrous magnesium sulfate, filtered, and the filtrate was rotary evaporated under reduced pressure, and the obtained product was purified by silica gel column chromatography (n-hexane: dichloromethane, 5:1 to 2:1 gradient elution, programmed automatic uniform gradient elution, elution time 30 minutes) to obtain an intermediate compound;

[0090] Step B: 2.0 mmol of the intermediate compound obtained in step A, 2.0 mmol of bis(4-methoxyphenyl)amine, 20 mmol of potassium carbonate, 0.2 mmol of tetrakis(triphenylphosphine)palladium were placed in 50 mL of toluene solvent, heated to reflux at 90°C under nitrogen atmosphere for 24 hours, after the reaction was completed, the reaction solution was cooled to room temperature and rotary evaporated under reduced pressure, then extracted with dichloromethane and water system (the volume ratio of dichloromethane to water was 3:1), the organic phase was washed with saturated sodium chloride water and dried over anhydrous magnesium sulfate, filtered, and the filtrate was rotary evaporated under reduced pressure, and the obtained product was purified by silica gel column chromatography (n-hexane: dichloromethane, 5:1 to 2:1 gradient elution, programmed automatic uniform gradient elution, elution time 30 minutes) to obtain the target compound (I) with a yield of 60%.

[0091] To confirm the structure of the target compound (I), nuclear magnetic resonance hydrogen spectrum (H NMR) and electrospray high resolution mass spectrum (ESI-HRMS) were used to determine the results, and the determination results were as follows: 1 H NMR) and electrospray high resolution mass spectrum (ESI-HRMS) were used to determine the results, and the determination results were as follows:

[0092] Nuclear magnetic resonance characterization data (Bruker, AVANCE III TM HD) of the target compound (I): 1 H NMR (600 MHz, DMSO) δ 7.65 (m, 8H), 7.46 (m, 14H), 7.30 (m, 3H), 7.22 (m, 6H), 6.89 (m, 4H), 3.81 (s, 6H).

[0093] Electrospray high resolution mass spectrum (Bruker, maXis impact): ESI-HRMS m / z: [M + H]+ calcd for C56H42N3O2+, 788.3271; found 788.3268.

[0094] Example 2: Study on the optical and reactive oxygen species (ROS) generation properties of target compound (I)

[0095] The target compound (I) exhibits good photoresponse performance in the UV-Vis absorption spectrum, with a maximum absorption wavelength at 580 nm and strong absorption in the wavelength range of 400–650 nm, indicating that the compound is suitable for white light-excited ROS reaction research.

[0096] To further evaluate the ability of target compound (I) to generate reactive oxygen species (ROS) under white light irradiation, the commercially available singlet oxygen probe 9,10-anthrayl-bis(methylene)dimalonic acid (ABDA) was used for ROS detection. 10 μmol / L of target compound (I) was added to a 100 μmol / L ABDA aqueous system and exposed to white light (60 mW / cm²) for different durations (10 s, 20 s, 30 s, 40 s, 60 s, 80 s, 120 s). 2 After irradiation, the absorption peak intensity of ABDA at 378 nm was monitored by UV-Vis spectroscopy. The decrease in intensity indicates that oxidative degradation has occurred, thus indirectly reflecting the level of ROS formation.

[0097] Set up 2 processing groups:

[0098] ABDA group (control group): only 100 μmol / L ABDA;

[0099] Target product (I) + ABDA (experimental group): 100 μmol / L ABDA and 10 μmol / L target compound (I).

[0100] Test results as follows Figure 1 As shown, the results indicate that under the same illumination conditions, with varying white light irradiation times, the target product (I) generates ROS in aqueous solution, leading to the oxidative decomposition of ABDA. In contrast, the ABDA in the control group remains stable. The results in the figure show that within one minute, the ABDA in the experimental group is almost completely oxidized and decomposed. This means that the target compound (I) has the ability to rapidly generate large amounts of ROS, a characteristic that gives it a significant advantage in photodynamic sterilization and holds promise for developing highly efficient photocontrolled bactericidal materials or antibacterial agents.

[0101] Example 3: Photodynamic bactericidal test of target compound (I)

[0102] This embodiment uses viable cell counting to evaluate the effect of the target compound (I) prepared in Example 1 on Xanthomonas javanica (… Xanthomonas campestris ACCC 10048) fungicide or Xanthomonas citrus ( Xanthomonascitri CCTCC FB 2023476) under visible light.

[0103] I. Microbial culture and treatment method

[0104] After the bacteria to be tested (Xanthomonas campestris, Xanthomonas citri) were activated and cultured in beef extract protein peptone broth medium, 1 mL of bacterial solution with a concentration of 1 × 10 8 cfu / mL was centrifuged at a speed of 8000 rpm for 1 minute to collect the bacterial cells, which were then resuspended in physiological saline to a final concentration of 1 × 10 3 cfu / mL to obtain a physiological saline resuspended bacterial solution. A solution of the target compound (I) with a concentration of 1 mmol / L was prepared using DMSO as the solvent.

[0105] Treatment group 1: 10 μL of the target compound (I) solution with a concentration of 1 mmol / L was added to 990 μL of the Xanthomonas campestris physiological saline resuspended bacterial solution to achieve a final concentration of 10 μmol / L.

[0106] Treatment group 2: 10 μL of the target compound (I) solution with a concentration of 1 mmol / L was added to 990 μL of the Xanthomonas citri physiological saline resuspended bacterial solution to achieve a final concentration of 10 μmol / L.

[0107] The samples in each treatment group were irradiated under a daylight lamp (60 mW / cm 2 ) for different times (0, 1, 5, and 10 minutes), with 0 minutes of irradiation (i.e., no daylight lamp irradiation) as the control group. Three biological replicates were set for each treatment group.

[0108] After the irradiation was completed, 50 μL of the bacterial solution in each treatment group was evenly spread on a plate (beef extract protein peptone agar medium) and placed in a 30°C constant temperature incubator for 48 hours of culture. The colony forming units (CFU) were counted, the bacterial survival rate was calculated, and the photodynamic bactericidal ability of the target compound (I) was evaluated.

[0109] II. Experimental results and analysis

[0110] The results of the bacterial survival rate determination are shown in Figure 2 The results show that after 10 minutes of white light irradiation, the target compound (I) at a concentration of 10 μmol / L almost completely killed Xanthomonas campestris and Xanthomonas citri. Compared with the control group, it showed a significant bactericidal effect.

[0111] In summary, the target compound (I) exhibits excellent ROS production ability under visible light excitation and has a good photodynamic bactericidal effect on Xanthomonas bacteria, which has the potential to be used as an efficient photodynamic antibacterial agent.

[0112] Example 4 Preservation test of coating of target compound (I) on mango

[0113] This example is used to evaluate the application potential of target compound (I) in fruit and vegetable preservation, in particular, its effect of extending the storage period of mango by photodynamic sterilization.

[0114] I. Experimental method

[0115] Prepare a solution of target compound (I) with a concentration of 1 mmol / L using DMSO as the solvent.

[0116] Add 2 g of polyvinyl alcohol (PVA) to 99 mL of deionized water, fully dissolve under the condition of heating and stirring, then add 0.2 g of glycerol, stir uniformly, and after the solution cools to room temperature, add 1 mL of target compound (I) solution with a concentration of 1 mmol / L (final concentration of 10 μmol / L), and the same composition of coating solution without adding target compound is used as a blank control group.

[0117] Immerse fresh, mechanically undamaged mangoes in the above coating solutions, respectively, and after taking them out, dry naturally to form a uniform coating on the surface of the fruit. After coating treatment, the mango samples are irradiated under a daylight lamp (60 mW / cm 2 ) for 10 minutes, and then stored at room temperature, and the surface state changes of the fruit are observed and recorded daily.

[0118] II. Experimental results

[0119] The experimental results are shown in Figure 3 The results show that after one week of storage, the mangoes in the blank control group have obvious black spots on the surface, indicating that microbial infection and rotting have occurred; while the mangoes in the target compound (I) treatment group remain basically intact, with no obvious disease spots. This indicates that target compound (I) significantly delays the decay process of the fruit.

[0120] In summary, target compound (I) has good preservation effect on mangoes, and target compound (I) shows good application prospects in the field of fruit and vegetable preservation, and has the potential to be developed as a green, safe and efficient light-controlled antibacterial preservation material.

[0121] Example 5 Preparation of photodynamic antibacterial preservation bag and antibacterial effect test

[0122] I. Preparation of photodynamic antibacterial preservation bag

[0123] Prepare a solution of target compound (I) with a concentration of 1 mmol / L using DMSO as the solvent.

[0124] Dissolve 3 g of polylactic acid (PLA) in 99 mL of dichloromethane, after stirring to complete dissolution, add 0.15 g of polyethylene glycol (PEG 8000), mix evenly, then add 1 mL of 1 mmol / L target compound (I) solution (final concentration is 10 μmol / L) to obtain a mixed solution.

[0125] Solution casting method was used to prepare thin films: pour the mixed solution into a clean mold, and naturally volatilize the solvent into a film in a ventilated environment. The obtained thin film is cut into appropriate size after taking out, and two are overlapped, and the three edges are heat sealed and packaged, leaving one side open for loading fruit and vegetable samples, thereby preparing an antibacterial and fresh-keeping bag with a photodynamic sterilization function.

[0126] II. Test method for antibacterial effect of fresh-keeping bag

[0127] Select fresh mangoes with consistent maturity for preservation experiments, and set up 2 groups of treatments.

[0128] Blank control group: use PE fresh-keeping bags to pack mangoes, 4 mangoes per bag, without light treatment, a total of 20 mangoes are packed;

[0129] Antibacterial fresh-keeping group: use the photodynamic antibacterial fresh-keeping bag prepared in this embodiment to pack mangoes, 4 mangoes per bag, a total of 20 mangoes are packed, and irradiated under a daylight lamp (60 mW / cm 2 ) for 10 minutes.

[0130] Place the mango samples of the two groups of treatments in the fruit and vegetable storage box for preservation experiments, set the experimental conditions to be temperature 23±1℃, relative humidity 60%±2%. Observe and record the occurrence of fruit surface diseases every day, count the mangoes with black spot disease, and calculate the proportion of diseased fruits in each group to evaluate the antibacterial performance of the fresh-keeping bag.

[0131] III. Experimental results

[0132] The experimental results are shown in Table 1. After 10 days of storage, the proportion of mangoes with black spot disease in the blank control group was as high as 60%, while no black spot disease occurred in the mangoes packed with the photodynamic antibacterial fresh-keeping bag. The results show that the photodynamic antibacterial fresh-keeping bag prepared in this embodiment has good antibacterial effect and can effectively prevent black spot disease of mangoes.

[0133] Table 1. Proportion of mangoes with black spot disease under different storage time conditions

[0134]

[0135] The above embodiments are the preferred embodiments of the present application, but the embodiments of the present application are not limited to the above embodiments, and any changes, modifications, substitutions, combinations, simplifications, etc. made without departing from the spirit and principles of the present application should be equivalent replacement manners and should be included in the protection scope of the present application.

Claims

1. A compound, characterized in that, The structural formula is shown as formula (I): Formula (I).

2. Process for the preparation of a compound according to claim 1, characterized in that, The intermediate compound is obtained by coupling reaction of 2,3-bis(4-bromophenyl)-2-butadienenitrile and (4-(1,2,2-triphenylvinyl)phenyl)boronic acid under alkaline condition and inert gas protection in the presence of a palladium catalyst; the intermediate compound is subjected to coupling reaction again with bis(4-methoxyphenyl)amine in the presence of a palladium catalyst to obtain the compound shown as formula (I).

3. The preparation method according to claim 2, characterized in that, The method comprises the following steps: Step A: 2,3-bis(4-bromophenyl)-2-butadienenitrile, (4-(1,2,2-triphenylvinyl)phenyl)boronic acid, potassium carbonate and a palladium catalyst are placed in an aprotic solvent and reacted under inert gas protection at 60-70 DEG C; after the reaction is completed, the solid reaction product is recovered to obtain the intermediate compound; Step B: the intermediate compound obtained in step A, bis(4-methoxyphenyl)amine, potassium carbonate and a palladium catalyst are placed in toluene solvent and reacted under inert gas protection at 85-95 DEG C; after the reaction is completed, the solid reaction product is recovered to obtain the compound shown as formula (I).

4. The preparation method according to claim 2, characterized in that, In step A, the mass ratio of 2,3-bis(4-bromophenyl)-2-butadienenitrile, (4-(1,2,2-triphenylvinyl)phenyl)boronic acid, potassium carbonate and a palladium catalyst is 1:(1-2):(8-12):(0.01-0.03).

5. The preparation method according to claim 2, characterized in that, In step B, the mass ratio of the intermediate compound, bis(4-methoxyphenyl)amine, potassium carbonate and a palladium catalyst is 1:(1-2):(8-12):(0.05-0.15).

6. The preparation method according to claim 2, characterized in that, The reaction time in step A and step B is 20-28 hours.

7. Use of the compound of claim 1 in the preparation of a product for combating bacteria of the genus Xanthomonas.

8. Use of the compound of claim 1 in food preservation.

9. Use of the compound of claim 1 in the preparation of a product for food preservation.

10. Use of the compound of claim 1 in the preparation of a product for preventing and treating bacterial black rot.

11. A product against Xanthomonas bacteria, characterized in that, The compound of claim 1 is contained.

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