1-methylcyclopropene oil suspension and method of making same

Abstract

The application belongs to the technical field of pesticide preparation, and particularly relates to 1-methylcyclopropene oil suspending agent and a preparation method thereof. The cyclodextrin inclusion compound of 1-methylcyclopropene is dispersed in a non-water medium, so that the rapid release of the cyclodextrin inclusion compound of 1-methylcyclopropene caused by water is avoided, the stability of the 1-methylcyclopropene oil suspending agent is improved, and meanwhile, the phosphatidylcholine is used in combination with an emulsifier, a thickening agent and other auxiliaries, so that the problem of high viscosity caused by the dispersion of cyclodextrin in an oil medium is solved, the appropriate viscosity of the 1-methylcyclopropene oil suspending agent is ensured, the use and storage are facilitated, the environment is friendly, and the 1-methylcyclopropene oil suspending agent can be used in open space and closed space at the same time.

Description

Technical Field

[0001] This invention belongs to the field of pesticide formulation technology, specifically relating to 1-methylcyclopropene oil suspension and its preparation method. Background Technology

[0002] Ethylene is a common compound, primarily derived from ripe fruits. Whether exogenous or endogenous, ethylene induces a series of physiological and biochemical reactions during plant growth and development, such as promoting germination, root spread, flowering and withering, and fruit ripening; it is an important plant growth regulator. However, for fruits and vegetables, transportation and storage require time, and maintaining their freshness during these processes is a significant challenge. Statistics show that approximately 30% of the world's annual losses of flowers, fruits, and vegetables are due to improper storage, and 15-25% of these losses are caused by aging due to ethylene. Effectively controlling ethylene production and its effects will help delay the aging of fruits and vegetables and extend their post-harvest life. One important aspect is the use of ethylene receptor inhibitors to regulate the physiological effects of ethylene. Ethylene receptor inhibitors compete for ethylene receptors in plants, binding reversibly or irreversibly to these receptors, hindering normal ethylene binding, and thus inhibiting the series of physiological and biochemical processes induced by ethylene. Cyclopropene compounds, such as cyclopropene (CP), 1-methylcyclopropene (1-MCP), 3-methylcyclopropene (3-MCP), and 3,3-dimethylcyclopropene (3,3-DMCP), can competitively antagonize the ethylene effect, blocking ethylene signal transduction and inhibiting ethylene sensing and physiological effects. The discovery of these compounds provides new tools for controlling postharvest senescence in fruits and vegetables. Among these cyclopropene compounds, 1-methylcyclopropene exhibits the most prominent effect. This compound is gaseous at 10°C, relatively stable, highly reactive, odorless, requires extremely low concentrations for treatment, and is non-toxic to humans and animals within a concentration range sufficient to inhibit ethylene response while ensuring adequate absorption in fruit and vegetable tissues. Therefore, it has significant theoretical importance and potential commercial application value in extending the postharvest life of fruits and vegetables and in studying ethylene metabolism.

[0003] Currently, 1-methylcyclopropene is typically used by encapsulating it with cyclodextrin to prepare effervescent tablets. However, effervescent tablets require use in a confined space, which significantly limits their application. Preparing 1-methylcyclopropene as an oil suspension allows for spraying, expanding its application range to both confined and open spaces. Furthermore, it can be sprayed in orchards and vegetable fields to prevent fruit drop and delay the senescence of vegetables, fruits, and horticultural products, which is of great significance for the promotion and application of 1-methylcyclopropene. Chinese patent CN108703139 discloses a 1-methylcyclopropene oil suspension, comprising an oil suspension diluted with oil and a dispersible oil suspension diluted with water, wherein the 1-methylcyclopropene is encapsulated in microcapsules using suitable materials, and then prepared as a formulation. However, microencapsulation of 1-methylcyclopropene is difficult and costly, and the microcapsule materials are not completely degradable, posing a potential problem of incomplete release and environmental risks. Chinese patent CN101356917A discloses a method for obtaining oil formulations by grinding cyclopropene compounds in an oil medium. These oil formulations can be applied to plants to prevent premature maturation. However, cyclodextrins are polysaccharides, and after grinding in an oil medium, they often have very high viscosity. High-viscosity products are not conducive to room temperature storage and are inconvenient to use. Therefore, compared with 1-methylcyclopropene effervescent tablets, existing 1-methylcyclopropene oil suspensions, although usable in open spaces, still suffer from poor stability, inconvenient storage, and a significant environmental impact. Summary of the Invention

[0004] The purpose of this invention is to provide a 1-methylcyclopropene oil suspension and its preparation method. The 1-methylcyclopropene oil suspension has good stability, is easy to store, and is environmentally friendly.

[0005] This invention provides a 1-methylcyclopropene oil suspension, prepared from raw materials comprising the following mass percentages: 0.1%-2% 1-methylcyclopropene, 5%-15% emulsifier, 0.1%-5% phosphatidylcholine, 0.5%-2% thickener, and the balance being a non-aqueous medium;

[0006] The 1-methylcyclopropene is used in the form of a cyclodextrin inclusion complex of 1-methylcyclopropene.

[0007] Preferably, the cyclodextrin inclusion complex of 1-methylcyclopropene comprises cyclodextrin and 1-methylcyclopropene encapsulated within the lumen of the cyclodextrin, and the mass ratio of 1-methylcyclopropene to the cyclodextrin inclusion complex of 1-methylcyclopropene is 1-3:100.

[0008] Preferably, the cyclodextrin includes α-cyclodextrin, β-cyclodextrin, or γ-cyclodextrin.

[0009] Preferably, the viscosity of the 1-methylcyclopropene oil suspension is 300-1000 mPa·s.

[0010] Preferably, the emulsifier includes several of the following: fatty alcohol polyoxyethylene ether, alkylphenol polyoxyethylene ether, castor oil polyoxyethylene ether, sodium dioctyl sulfonate, and dodecylbenzene sulfonate.

[0011] Preferably, the non-aqueous medium includes one or more of soybean oil, corn oil, and methyl oleate.

[0012] Preferably, the thickener comprises fumed silica and / or organobentonite.

[0013] The present invention also provides a method for preparing the 1-methylcyclopropene oil suspension described in the above technical solution, comprising the following steps:

[0014] The cyclodextrin inclusion complex of 1-methylcyclopropene, emulsifier, phosphatidylcholine, thickener and non-aqueous medium are mixed, and the resulting mixture is ground to 2-3 μm to obtain a grinding mixture.

[0015] The grinding mixture was subjected to solid-liquid separation to obtain the 1-methylcyclopropene oil suspension.

[0016] Preferably, the grinding temperature is below 40°C.

[0017] The present invention also provides a method for delaying the senescence of fruits and vegetables and / or preventing premature ripening of fruits and vegetables, comprising: applying a 1-methylcyclopropene oil suspension to the plants by spraying, smearing or impregnation; wherein the 1-methylcyclopropene oil suspension is the 1-methylcyclopropene oil suspension described in the above technical solution or the 1-methylcyclopropene oil suspension obtained by the preparation method described in the above technical solution.

[0018] Beneficial effects:

[0019] This invention provides a 1-methylcyclopropene oil suspension, prepared from raw materials comprising the following mass percentages: 0.1%-2% 1-methylcyclopropene, 5%-15% emulsifier, 0.1%-5% phosphatidylcholine, 0.5%-2% thickener, and the remainder being a non-aqueous medium; wherein the 1-methylcyclopropene is used in the form of a cyclodextrin inclusion complex of 1-methylcyclopropene. This invention improves the stability of the 1-methylcyclopropene oil suspension by dispersing the cyclodextrin inclusion complex of 1-methylcyclopropene in a non-aqueous medium, thus avoiding rapid release of the cyclodextrin inclusion complex of 1-methylcyclopropene upon contact with water. Simultaneously, the use of phosphatidylcholine in combination with emulsifiers and thickeners solves the problem of high viscosity caused by the dispersion of cyclodextrin in oily media, ensuring a suitable viscosity for the 1-methylcyclopropene oil suspension, which is beneficial for use and storage, environmentally friendly, and suitable for use in both open and enclosed spaces. Detailed Implementation

[0020] This invention provides a 1-methylcyclopropene oil suspension, prepared from raw materials comprising the following mass percentages: 0.1%-2% 1-methylcyclopropene, 5%-15% emulsifier, 0.1%-5% phosphatidylcholine, 0.5%-2% thickener, and the balance being a non-aqueous medium;

[0021] The 1-methylcyclopropene is used in the form of a cyclodextrin inclusion complex of 1-methylcyclopropene.

[0022] The 1-methylcyclopropene oil suspension of the present invention comprises 0.1%-2% 1-methylcyclopropene, more preferably 0.5%-1.5%, and more preferably 1%-1.5% by mass percentage. The 1-methylcyclopropene of the present invention is used in the form of a cyclodextrin inclusion complex of 1-methylcyclopropene; the cyclodextrin inclusion complex of 1-methylcyclopropene preferably comprises cyclodextrin and 1-methylcyclopropene encapsulated within the lumen of the cyclodextrin, and the mass ratio of 1-methylcyclopropene to the cyclodextrin inclusion complex of 1-methylcyclopropene is preferably 1-3:100, more preferably 3:100. The cyclodextrin inclusion complex of 1-methylcyclopropene of the present invention is preferably obtained by purchase, and the source of purchase is not particularly limited, as long as the mass ratio of 1-methylcyclopropene to cyclodextrin in the cyclodextrin inclusion complex of 1-methylcyclopropene is satisfied. The cyclodextrin of the present invention preferably includes α-cyclodextrin, β-cyclodextrin, or γ-cyclodextrin, and more preferably α-cyclodextrin. The present invention uses cyclodextrin to encapsulate 1-methylcyclopropene, which can enhance the stability of 1-methylcyclopropene and reduce the release rate of 1-methylcyclopropene.

[0023] The 1-methylcyclopropene oil suspension of the present invention comprises 5%-15% emulsifier, preferably 7%-11%, and more preferably 8%-10%, by weight percentage. The emulsifier of the present invention preferably includes several selected from fatty alcohol polyoxyethylene ether, alkylphenol polyoxyethylene ether, castor oil polyoxyethylene ether, sodium dioctyl sulfonate, and dodecylbenzene sulfonate; the use of several emulsifiers in combination is beneficial to enhancing the stability of the system.

[0024] The 1-methylcyclopropene oil suspension of the present invention comprises 0.1%-5% phosphatidylcholine, preferably 0.5%-3.0%, and more preferably 1%-2%, by weight percentage. The phosphatidylcholine of the present invention is used as a viscosity modifier, which can help reduce the viscosity of the formulation after cyclodextrin dispersion, making the 1-methylcyclopropene oil suspension more stable and easier to transport and store.

[0025] The 1-methylcyclopropene oil suspension of the present invention comprises 0.5%-2% thickener, preferably 0.5%-1%, by weight percentage. The thickener of the present invention preferably comprises fumed silica and / or organobentonite, more preferably fumed silica or organobentonite.

[0026] In addition to the cyclodextrin inclusion complex, emulsifier, phosphatidylcholine, and thickener of 1-methylcyclopropene described above, the 1-methylcyclopropene oil suspension of the present invention preferably also includes a balance of a non-aqueous medium, by weight percentage. The non-aqueous medium of the present invention preferably includes one or more of soybean oil, corn oil, and methyl oleate, more preferably soybean oil, corn oil, or methyl oleate. The non-aqueous medium of the present invention is preferably used as a diluent. The present invention uses a non-aqueous medium instead of water to dilute other components in the 1-methylcyclopropene oil suspension, reducing the release rate of 1-methylcyclopropene and avoiding rapid release of 1-methylcyclopropene upon contact with water.

[0027] The viscosity of the 1-methylcyclopropene oil suspension of the present invention is preferably 300-1000 mPa·s, more preferably 450-588 mPa·s. The viscosity range of the 1-methylcyclopropene oil suspension is conducive to the stability of the 1-methylcyclopropene oil suspension and facilitates its use and storage.

[0028] The present invention also provides a method for preparing the 1-methylcyclopropene oil suspension described in the above technical solution, comprising the following steps:

[0029] The cyclodextrin inclusion complex of 1-methylcyclopropene, emulsifier, phosphatidylcholine, thickener and non-aqueous medium are mixed, and the resulting mixture is ground to 2-3 μm to obtain a grinding mixture.

[0030] The grinding mixture was subjected to solid-liquid separation to obtain the 1-methylcyclopropene oil suspension.

[0031] This invention involves mixing a cyclodextrin inclusion complex of 1-methylcyclopropene, an emulsifier, phosphatidylcholine, a thickener, and a non-aqueous medium. The resulting mixture is then ground to a particle size of 2-3 μm to obtain a ground mixture. After mixing, this invention preferably stirs the resulting mixture to ensure uniform mixing of all components. This invention preferably uses a grinding mill to grind the mixture. The type and parameters of the grinding mill are not particularly limited; conventional grinding mills and grinding parameters in the art can be used. The grinding temperature of this invention is preferably below 40°C to ensure that the material does not undergo a change in state due to excessive temperature during the grinding process. The 2-3 μm ground mixture of this invention allows the components to be dispersed in the non-aqueous medium in the form of tiny particles.

[0032] After obtaining the milled mixture, the present invention performs solid-liquid separation on the milled mixture to obtain the 1-methylcyclopropene oil suspension. The preferred method of solid-liquid separation in the present invention is filtration. The present invention does not specifically limit the parameters of the filtration; conventional parameters in the art can be used.

[0033] This invention improves the stability of 1-methylcyclopropene oil suspension by dispersing 1-methylcyclopropene cyclodextrin inclusion complexes in a non-aqueous medium, thus avoiding the rapid release of 1-methylcyclopropene cyclodextrin inclusion complexes upon contact with water. Simultaneously, the use of phosphatidylcholine in combination with emulsifiers and thickeners solves the problem of high viscosity caused by cyclodextrin dispersion in oily media, ensuring a suitable viscosity for the 1-methylcyclopropene oil suspension. This facilitates use and storage, is environmentally friendly, and allows for use in both open and enclosed spaces.

[0034] The 1-methylcyclopropene oil suspension of this invention can exert its effect by contacting plants through spraying, smearing, or impregnation, offering diverse application methods. Therefore, methods of applying the 1-methylcyclopropene oil suspension to plants through spraying, smearing, or impregnation to delay fruit and vegetable senescence and / or prevent premature ripening also fall within the scope of protection of this invention, particularly extending the post-harvest lifespan of fruits and vegetables. This invention does not impose specific limitations on the dosage of the 1-methylcyclopropene oil suspension; adjustments can be made according to conventional needs. The plants used in this invention preferably include fruits and / or vegetables.

[0035] To further illustrate the present invention, the technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0036] Example 1

[0037] The composition and preparation method of 0.1% 1-methylcyclopropene oil suspension, by mass percentage, are as follows:

[0038]

[0039] Weigh the materials according to the above formula, wherein 1-methylcyclopropene is used as 1-methylcyclopropene encapsulated with cyclodextrin (the mass ratio of 1-methylcyclopropene encapsulated with α-cyclodextrin to 1-methylcyclopropene is 100:3). After mixing evenly, grind the mixture to a median particle size D using a vertical sand mill at 35°C. 50 =2.52μm, after filtration, 0.1% 1-methylcyclopropene oil suspension is obtained.

[0040] Example 2

[0041] The composition and preparation method of 0.5% 1-methylcyclopropene oil suspension, by mass percentage, are as follows:

[0042]

[0043] Weigh the materials according to the above formula, wherein 1-methylcyclopropene is used in the form of 1-methylcyclopropene encapsulated with cyclodextrin (the mass ratio of 1-methylcyclopropene encapsulated with α-cyclodextrin to 1-methylcyclopropene is 100:3). After mixing evenly, grind the mixture to a median particle size D using a vertical sand mill at 30°C. 50 =2.30μm, after filtration, a 0.5% 1-methylcyclopropene oil suspension is obtained.

[0044] Example 3

[0045] The composition and preparation method of a 1% 1-methylcyclopropene oil suspension, by mass percentage, are as follows:

[0046]

[0047] Weigh the materials according to the above formula, wherein 1-methylcyclopropene is used in the form of 1-methylcyclopropene encapsulated with cyclodextrin (the mass ratio of 1-methylcyclopropene encapsulated with α-cyclodextrin to 1-methylcyclopropene is 100:3). After mixing evenly, grind the mixture to a median particle size D using a vertical sand mill at 30°C. 50 =2.30μm, after filtration, 1% 1-methylcyclopropene oil suspension is obtained.

[0048] Example 4

[0049] The composition and preparation method of 1.5% 1-methylcyclopropene oil suspension, by mass percentage, are as follows:

[0050]

[0051]

[0052] Weigh the materials according to the above formula, wherein 1-methylcyclopropene is used as 1-methylcyclopropene encapsulated with cyclodextrin (the mass ratio of 1-methylcyclopropene encapsulated with α-cyclodextrin to 1-methylcyclopropene is 100:3). After mixing evenly, grind the mixture to a median particle size D using a vertical sand mill at 35°C. 50 =2.09μm, after filtration, a 1.5% 1-methylcyclopropene oil suspension is obtained.

[0053] Example 5

[0054] The composition and preparation method of a 2% 1-methylcyclopropene oil suspension, by mass percentage, are as follows:

[0055]

[0056] Weigh the materials according to the above formula, wherein 1-methylcyclopropene is used in the form of 1-methylcyclopropene encapsulated with cyclodextrin (the mass ratio of 1-methylcyclopropene encapsulated with α-cyclodextrin to 1-methylcyclopropene is 100:3). After mixing evenly, grind the mixture to a median particle size D using a vertical sand mill at 30°C. 50 =2.31μm, after filtration, a 1.5% 1-methylcyclopropene oil suspension is obtained.

[0057] In the above examples, 1-methylcyclopropene was formed by inclusion complexation with α-cyclodextrin as an inclusion agent, purchased from Shandong Binzhou Zhiyuan Biotechnology Co., Ltd., and was a 3% 1-methylcyclopropene cyclodextrin inclusion complex. All emulsifiers and other components used were commercially available. For example, Nongru 1602 was purchased from Nanjing Taihua Co., Ltd.; sodium dioctyl sulfosuccinate was purchased from Hebei Yancheng Chemical Co., Ltd.; calcium dodecylbenzenesulfonate was purchased from Zhongshan Chemical Co., Ltd.; and Aerosil 974 and SK 04 were purchased from Suzhou Zhongcai Mineral Materials Co., Ltd. Methyl oleate, soybean oil, and corn oil were all purchased from the market.

[0058] Comparative Example 1

[0059] The composition and preparation method of a 1% 1-methylcyclopropene oil suspension, by mass percentage, are as follows:

[0060]

[0061] Weigh the materials according to the above formula, wherein 1-methylcyclopropene is used as 1-methylcyclopropene inclusion complex encapsulated with cyclodextrin (the mass ratio of 1-methylcyclopropene encapsulated with α-cyclodextrin to 1-methylcyclopropene is 100:3). After mixing evenly, grind the mixture to a median particle size D using a vertical sand mill at 30°C. 50=2.13μm, after filtration, 1% 1-methylcyclopropene oil suspension was obtained. The sample gelled under both room temperature and heat storage. The phosphatidylcholine in Examples 2-5 was removed, and the missing phosphatidylcholine was made up with the corresponding non-aqueous medium in each example. The sample was prepared according to the preparation method of Example 1. The sample gelled under both room temperature and heat storage. The heat storage test was conducted according to the method of low temperature stability of pesticides in GB / T 19136-2003.

[0062] Example 6

[0063] 1-Methylcyclopropene oil suspension quality technical indicators

[0064] Currently, there are no technical standards for 1-methylcyclopropene suspensions. Therefore, the general quality technical indicators for suspensions were used for testing. In the dilution step of the suspension standard, methyl oleate was used instead of water. The remaining test steps were the same as those in the suspension standard (GB 18171-2000). The 1-methylcyclopropene oil suspensions prepared in Examples 1-5 did not exhibit any paste-like or clumping phenomena after cold and hot storage tests.

[0065] Viscosity testing was performed using a Brookfield viscometer with a #3 rotor at 60 rpm. Content analysis was conducted using gas chromatography on an Agilent Technologies 6890N gas chromatograph. Experimental conditions included: an HP-PLOTQ column (USA, A1203 support), 30 m length, 0.53 mm inner diameter, 40 μm film thickness, flame ionization detector (FID), detector temperature 250 °C, air flow rate 450 mL / min, hydrogen flow rate 40 mL / min, makeup gas flow rate 45 mL / min, nitrogen as carrier gas at 5.0 mL / min, column head 3.98 psi, injection port temperature 200 °C, initial temperature 50 °C, and a heating rate of 20 °C / min to reach a final temperature of 250 °C. The thermal storage stability of 1-methylcyclopropene oil suspension was tested according to section 2.3 of GB / T 19136-2003; the cold storage stability was tested according to the low-temperature stability method for pesticides in GB / T 19136-2003. The results are shown in Table 1.

[0066] Table 1. Quality Technical Indicators of 1-Methylcyclopropene Oil Suspension

[0067]

[0068]

[0069] From the above examples, it can be concluded that the 1-methylcyclopropene oil suspension of the present invention has higher stability and a wider range of applications.

[0070] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. People can obtain other embodiments based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A 1-methylcyclopropene oil suspension, characterized in that, It is prepared from raw materials comprising the following mass percentages: 0.1%-2% 1-methylcyclopropene, 5%-15% emulsifier, 0.1%-5% phosphatidylcholine, 0.5%-2% thickener, and the balance being non-aqueous medium; The 1-methylcyclopropene is used in the form of a cyclodextrin inclusion complex of 1-methylcyclopropene; The viscosity of the 1-methylcyclopropene oil suspension is 450-588 mPa·s.

2. The 1-methylcyclopropene oil suspension according to claim 1, characterized in that, The cyclodextrin inclusion complex of 1-methylcyclopropene comprises cyclodextrin and 1-methylcyclopropene encapsulated within the lumen of the cyclodextrin, wherein the mass ratio of 1-methylcyclopropene to the cyclodextrin inclusion complex of 1-methylcyclopropene is 1-3:

100.

3. The 1-methylcyclopropene oil suspension agent according to claim 2, characterized in that, The cyclodextrins include α-cyclodextrin, β-cyclodextrin, or γ-cyclodextrin.

4. The 1-methylcyclopropene oil suspension agent according to claim 1, characterized in that, The emulsifier includes several of the following: fatty alcohol polyoxyethylene ether, alkylphenol polyoxyethylene ether, castor oil polyoxyethylene ether, sodium dioctyl sulfonate, and dodecylbenzene sulfonate.

5. The 1-methylcyclopropene oil suspension agent according to claim 1, characterized in that, The non-aqueous medium includes one or more of soybean oil, corn oil, and methyl oleate.

6. The 1-methylcyclopropene oil suspension agent according to claim 1, characterized in that, The thickener includes fumed silica and / or organobentonite.

7. The method for preparing the 1-methylcyclopropene oil suspension according to any one of claims 1-6, characterized in that, Includes the following steps: The cyclodextrin inclusion complex of 1-methylcyclopropene, emulsifier, phosphatidylcholine, thickener and non-aqueous medium are mixed, and the resulting mixture is ground to 2-3 μm to obtain a ground mixture. The grinding mixture was subjected to solid-liquid separation to obtain the 1-methylcyclopropene oil suspension.

8. The preparation method according to claim 7, characterized in that, The grinding temperature is below 40°C.

9. A method for delaying fruit and vegetable senescence and / or preventing premature ripening of fruits and vegetables, characterized in that, include: The 1-methylcyclopropene oil suspension is applied to plants by spraying, smearing, or impregnation; the 1-methylcyclopropene oil suspension is the 1-methylcyclopropene oil suspension according to any one of claims 1-6 or the 1-methylcyclopropene oil suspension obtained by the preparation method according to claim 7 or 8.

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