Coniferyl aldehyde salicylate molecular device and preparation method and application thereof

Abstract

The application belongs to the technical field of liquid nutrient analysis and detection, and provides a coniferyl aldehyde salicylate molecular device, a preparation method and application thereof. The method comprises the following steps: mixing a coniferyl aldehyde solution, a dehydrating agent dispersion liquid and a salicylate derivative solution, and performing a dehydration condensation reaction on the mixed liquid to obtain the coniferyl aldehyde salicylate molecular device. The coniferyl aldehyde salicylate molecular device has a high viscosity sensitivity coefficient, a relatively stable chemical structure, a strong visual effect, a relatively stable light signal in a relatively wide pH range, is not sensitive to the polarity of a solvent, has good solvent tolerance, can be used as a molecular tool to measure the viscosity of a microenvironment of a nutrient in situ, the detection can be realized without relying on shearing and relative movement, a large amount of samples can be avoided, the whole process is rapid, efficient and convenient, and the viscosity change of a liquid nutrient containing a large amount of pseudoplastic fluid can be effectively measured.

Description

Technical Field

[0001] This invention relates to the field of liquid nutrient analysis and detection technology, and in particular to a pine aldehyde salicylate molecular device, its preparation method, and its application. Background Technology

[0002] Liquid nutrients are plant nutrient supplements prepared using water-soluble or emulsification technologies. Their main components are complex, containing inorganic salts, trace elements, organic additives, and functional auxiliaries, demonstrating unparalleled advantages in agricultural planting, horticulture, and plant cultivation. As a liquid functional fluid, its physical micro-viscosity directly affects the final application effect. Viscosity, as a core parameter of rheological properties, relates to the fluidity, leaf adhesion, pipeline delivery efficiency, and nutrient release rate of liquid nutrients. For example, high-viscosity liquid nutrients may clog drip irrigation systems, but they can prolong leaf residence time, offering advantages such as better long-lasting residence time, delayed nutrient release, and less dissipation; low-viscosity liquid nutrients are more prone to runoff, but are suitable for mechanized spraying, are easier to diffuse, have stronger penetration, and better short-term release efficiency. The viscosity of liquid nutrient solutions in micro-regions is mainly determined by the concentration of the ingredients and functional nutrient additives, including high nitrate concentration, high colloid concentration, and nonlinear viscosity increase caused by emulsification. Therefore, accurate measurement of micro-region viscosity is crucial for the formulation optimization and quality control of liquid nutrient solution products.

[0003] Different users have varying needs for liquid nutrients, which manifests in their specific requirements regarding the relative viscosity of the nutrient solution. Currently, liquid nutrients with various functions have been developed. With the continuous rise in crop economics, controlling the appropriate spraying dosage and achieving rapid spraying effects can significantly improve crop growth and appearance, making them key adjuvants for enhancing crop growth efficiency. In fact, the added value in this field is enormous. Traditional methods for analyzing the viscosity of liquid nutrients mostly rely on various viscometers, requiring large sample volumes and long measurement times, and imposing stringent requirements on transparency and single-phase components. More importantly, it is difficult to accurately measure the micro-area viscosity of liquid nutrients containing a large amount of pseudoplastic fluids, because pseudoplastic fluids exhibit shear thinning during shear measurement. Furthermore, it is difficult to achieve in-situ viscosity measurements at the molecular level.

[0004] In the field of liquid nutrient analysis and detection, photochemical technology can measure the micro-region viscosity of liquid nutrients using molecular tools, ultimately manifesting as a visible light signal. This static response method effectively avoids errors caused by traditional shear-thinning techniques and significantly improves the optimization and control of liquid nutrient viscosity. Therefore, there is an urgent need to develop a molecular-level tool suitable for testing the viscosity of liquid nutrients to effectively address current detection technology bottlenecks and promote the refined monitoring and modulation of nutrient additives. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art by providing a pine aldehyde salicylate molecular device, its preparation method, and its application, thereby solving the problem of the difficulty in accurately measuring the micro-region viscosity of liquid nutrients in the prior art.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0007] This invention provides a pine aldehyde salicylate molecular device, the structural formula of which is:

[0008]

[0009] This invention also provides a method for preparing the aforementioned coniferyl aldehyde salicylate molecular device, comprising the following steps:

[0010] A coniferaldehyde solution, a dehydrating agent dispersion, and a salicylate derivative solution were mixed, and the mixture underwent a dehydration condensation reaction to obtain a coniferaldehyde-modified salicylate molecular device.

[0011] Preferably, the concentration of the coniferaldehyde solution is 1-5 mol / L, the concentration of the dehydrating agent dispersion is 1-6 mol / L, and the concentration of the salicylate derivative solution is 1-3 mol / L.

[0012] Preferably, the molar ratio of salicylate derivative, coniferaldehyde, and dehydrating agent in the mixture is 1:1 to 5:1 to 6.

[0013] Preferably, in the coniferaldehyde solution, the solvent is one or more of methanol, tetrahydrofuran, ethanol, N,N-dimethylformamide, ethyl acetate, and dimethyl sulfoxide; in the salicylate derivative solution, the solvent is an alcohol solvent, and the salicylate derivative is methyl 5-aminosalicylate.

[0014] Preferably, in the dehydrating agent dispersion, the solvent is one or more of methanol, ethanol, propanol, n-butanol, ethylene glycol, 1,2-propanediol, 1,3-propanediol and 1,3-butanediol, and the dehydrating agent is one or more of sodium carbonate, cesium carbonate, aluminum hydroxide, sodium bicarbonate, potassium carbonate, potassium bicarbonate and magnesium hydroxide.

[0015] Preferably, the specific mixing process is as follows: after mixing the coniferaldehyde solution and the dehydrating agent dispersion, the salicylate derivative solution is added dropwise, and the mixture is stirred continuously after the addition is completed to obtain a mixed solution; the rate of addition of the salicylate derivative solution is 2-8 mL / min.

[0016] As a preferred method, the process for mixing the coniferaldehyde solution and the dehydrating agent dispersion is as follows: first, stirring at low speed at room temperature, then heating under high speed stirring. The low speed stirring rate is 100-900 rpm for 0.1-2 h; the high speed stirring rate is 900-1800 rpm, and the temperature is raised to 70-110℃ at a rate of 1-5℃ / min.

[0017] The stirring rate is 900–1800 rpm, and the stirring time is 2–24 h.

[0018] Preferably, the product obtained from the dehydration condensation reaction is sequentially extracted, crystallized, centrifuged, and dried to obtain a pine aldehyde salicylate molecular device.

[0019] The present invention also provides the application of the aforementioned conifer aldehyde salicylate molecular device in the micro-area viscosity measurement of liquid nutrient, wherein the molar volume ratio of the conifer aldehyde salicylate molecular device to the liquid nutrient is 5-80 μmol: 0.005 L.

[0020] The beneficial effects of this invention include the following:

[0021] 1) The conifer aldehyde salicylate molecular device of the present invention is a coupling of natural conifer extract (conifer aldehyde) and natural salicylate derivative (methyl 5-aminosalicylate) to achieve the effective construction of functional molecules of natural organic matter. The required raw materials are abundant and belong to natural plant extracts and their derivatives. It realizes the development of high-value-added molecular tools by organically reconstructing natural products. The overall preparation process adopts a one-step method, which is simple and easy to implement. The amount used is very small (milligram level), and the application cost is very low. Moreover, this method of targeted modification of plant extracts is very much in line with the concept of low-carbon and sustainable development, avoiding the low yield and large consumption of organic reagents caused by complicated preparation processes.

[0022] 2) The pine aldehyde salicylate molecular device (MHMAAB) of the present invention can respond to changes in the viscosity of micro-regions of liquid nutrients, which helps to detect changes in the viscosity of physical micro-regions in situ. It has a high viscosity sensitivity coefficient (x = 0.65) and can form a flexible and rotatable state by introducing a Schiff base conjugated single and double bond alternating structure. Moreover, its chemical structure is relatively stable and can exist for a long time in complex liquid nutrients. Its emission wavelength peak is 508nm, which is typical green light, bright in color, and has a very strong visualization effect. In addition, the molecular device of the present invention can also emit a relatively stable light signal in a relatively wide pH range (3.0 to 10.0) and maintain good photostability during long-term irradiation. At the same time, it is not sensitive to the polarity of the solvent and has good solvent tolerance.

[0023] 3) The pine aldehyde salicylate molecular device (MHMAAB) of the present invention can be added to liquid nutrients and used as a molecular tool to measure the viscosity of the nutrient microenvironment in situ. The measurement process can be carried out without relying on shear and relative motion, and can avoid the consumption of a large number of samples. The whole process is fast, efficient and convenient, and can effectively measure the viscosity change of liquid nutrients containing a large amount of pseudoplastic fluid. Attached Figure Description

[0024] Figure 1 This is a schematic diagram illustrating the mechanism of the pine aldehyde salicylate molecular device of the present invention for detecting the viscosity of liquid nutrients in micro-regions;

[0025] Figure 2 This is a high-resolution mass spectrum of the pine aldehyde salicylate molecular device prepared in Example 1;

[0026] Figure 3 The nuclear magnetic resonance spectrum of the pine aldehyde salicylate molecular device prepared in Example 1 is shown.

[0027] Figure 4 The spectra of the pine aldehyde salicylate molecular device prepared in Example 1 in solutions of different viscosities are shown.

[0028] Figure 5 The linear fitting diagram of the optical signal intensity and solution viscosity of the coniferyl aldehyde salicylate molecular device prepared in Example 1 is shown.

[0029] Figure 6 The spectra of the pine aldehyde salicylate molecular device prepared in Example 1 in solutions with different pH values ​​are shown.

[0030] Figure 7 The results of photostability tests on the conifer aldehyde salicylate molecular device prepared in Example 1 in glycerol solution and purified water are shown.

[0031] Figure 8 The absorption spectra of the pine aldehyde salicylate molecular device prepared in Example 1 in different solvents;

[0032] Figure 9 The emission spectra of the pine aldehyde salicylate molecular device prepared in Example 1 in different liquid nutrients are shown. Detailed Implementation

[0033] This invention provides a pine aldehyde salicylate molecular device, the structural formula of which is:

[0034]

[0035] In this invention, the methyl 2-hydroxy-5-((3-(4-hydroxy-3-methoxyphenyl)allyl)amino)benzoate molecular device is methyl 2-hydroxy-5-((3-(4-hydroxy-3-methoxyphenyl)allyl)amino)benzoate, abbreviated as MHMAAB, with the molecular formula C. 18 H 17 NO5 has a theoretical relative molecular mass of 327.33600.

[0036] This invention also provides a method for preparing the aforementioned coniferyl aldehyde salicylate molecular device, comprising the following steps:

[0037] A coniferaldehyde solution, a dehydrating agent dispersion, and a salicylate derivative solution were mixed, and the mixture underwent a dehydration condensation reaction to obtain a coniferaldehyde-modified salicylate molecular device.

[0038] In this invention, the concentration of the coniferaldehyde solution is preferably 1-5 mol / L, more preferably 2-4 mol / L, and even more preferably 3 mol / L; the concentration of the dehydrating agent dispersion is preferably 1-6 mol / L, more preferably 2-5 mol / L, and even more preferably 3-4 mol / L; and the concentration of the salicylate derivative solution is preferably 1-3 mol / L, more preferably 1.5-2.5 mol / L, and even more preferably 2 mol / L.

[0039] In the mixture of the present invention, the molar ratio of salicylate derivative, coniferaldehyde and dehydrating agent is preferably 1:1 to 5:1 to 6, more preferably 1:2 to 4:2 to 5, and even more preferably 1:3:3 to 4.

[0040] In the coniferaldehyde solution of the present invention, the solvent is preferably one or more of methanol, tetrahydrofuran, ethanol, N,N-dimethylformamide, ethyl acetate and dimethyl sulfoxide; in the salicylate derivative solution, the solvent is preferably an alcohol solvent, and the salicylate derivative is preferably methyl 5-aminosalicylate.

[0041] In this invention, coniferaldehyde is dissolved in a solvent and stirred to obtain a coniferaldehyde solution; the stirring temperature is preferably 25-50°C, more preferably 30-45°C, and even more preferably 35-40°C; the stirring speed is preferably 300-1000 rpm, more preferably 400-800 rpm, and even more preferably 500-600 rpm; coniferaldehyde is a natural organic product extracted from coniferous wood; a salicylate derivative is dissolved in a solvent and stirred to obtain a salicylate derivative solution; the stirring speed is preferably 300-1000 rpm, more preferably 400-800 rpm, and even more preferably 500-600 rpm; the stirring temperature is preferably 25-50°C, more preferably 30-45°C, and even more preferably 35-40°C.

[0042] In the dehydrating agent dispersion of the present invention, the solvent is preferably one or more of methanol, ethanol, propanol, n-butanol, ethylene glycol, 1,2-propanediol, 1,3-propanediol and 1,3-butanediol, and the dehydrating agent is preferably one or more of sodium carbonate, cesium carbonate, aluminum hydroxide, sodium bicarbonate, potassium carbonate, potassium bicarbonate and magnesium hydroxide.

[0043] In this invention, the dehydrating agent is dispersed in a solvent and stirred to obtain a dehydrating agent dispersion; the stirring rate is preferably 600-1600 rpm, more preferably 800-1500 rpm, and even more preferably 1000-1100 rpm; the stirring temperature is preferably 25-60°C, more preferably 30-55°C, and even more preferably 40-45°C.

[0044] In this invention, the specific mixing process is as follows: after mixing the coniferaldehyde solution and the dehydrating agent dispersion, the salicylate derivative solution is added dropwise, and the mixture is stirred continuously after the addition is completed to obtain a mixed solution; the dropwise addition rate of the salicylate derivative solution is preferably 2-8 mL / min, more preferably 3-7 mL / min, and even more preferably 5-6 mL / min.

[0045] In this invention, the process of mixing the coniferaldehyde solution and the dehydrating agent dispersion is as follows: first, stirring at low speed at room temperature, and then heating under high speed stirring. The preferred stirring speed is 100-900 rpm, more preferably 200-800 rpm, and more preferably 400-500 rpm. The preferred time is 0.1-2 h, more preferably 0.5-1.5 h, and more preferably 1 h. The preferred stirring speed is 900-1800 rpm, more preferably 1000-1600 rpm, and more preferably 1200-1400 rpm. The preferred temperature is 70-110°C, more preferably 80-100°C, and more preferably 90°C. The preferred heating rate is 1-5°C / min, more preferably 2-4°C / min, and more preferably 3°C / min.

[0046] The stirring rate is preferably 900-1800 rpm, more preferably 1000-1600 rpm, and even more preferably 1200-1400 rpm. The stirring time is preferably 2-24 h, more preferably 5-20 h, and even more preferably 13-14 h.

[0047] In this invention, the product obtained from the dehydration condensation reaction is preferably subjected to extraction, crystallization, centrifugation and drying in sequence to obtain a pine aldehyde salicylate molecular device.

[0048] In this invention, the specific extraction process is as follows: the obtained product is subjected to solvent removal at -0.09 MPa to -0.07 MPa, preferably -0.08 MPa, and then extracted with a mixed solution of ethyl acetate and water. After collecting the organic phase, the solvent is removed under reduced pressure. The volume ratio of ethyl acetate to water is preferably 1 to 5:1, more preferably 2 to 4:1, and even more preferably 3:1. The pressure for removing the solvent under reduced pressure is preferably -0.09 MPa to -0.07 MPa, more preferably -0.08 MPa.

[0049] The specific crystallization process is as follows: the extracted product is mixed with ethanol, and the mixture is allowed to stand; the volume ratio of water to anhydrous ethanol in the ethanol is preferably 1:1 to 10, more preferably 1:3 to 7, and more preferably 1:5 to 6; the solid content of the mixture is preferably 10 to 80 mg / mL, more preferably 20 to 60 mg / mL, and more preferably 40 to 50 mg / mL; the standing temperature is preferably 1 to 8°C, more preferably 3 to 6°C, and more preferably 4 to 5°C; the standing time is preferably 10 to 30 h, more preferably 15 to 25 h, and more preferably 20 h.

[0050] The specific centrifugation process is as follows: the crystalline solid obtained from crystallization is mixed with ethanol, and the mixture is centrifuged; the volume ratio of water to anhydrous ethanol in the ethanol is preferably 1-20:1, more preferably 5-15:1, and even more preferably 10:1; the solid content of the mixture is preferably 10-80 mg / mL, more preferably 20-70 mg / mL, and even more preferably 40-50 mg / mL; the centrifugation speed is preferably 5000-10000 r / min, more preferably 6000-9000 r / min, and even more preferably 7000-8000 r / min; the number of centrifugations is preferably 1-3 times, and even more preferably 2 times; the time for each centrifugation is preferably 0.1-1.0 h, more preferably 0.3-0.8 h, and even more preferably 0.5 h;

[0051] The drying temperature is preferably 50–90°C, more preferably 60–80°C, and even more preferably 70°C. The drying time is preferably 10–24 h, more preferably 13–20 h, and even more preferably 14–16 h.

[0052] The present invention also provides the application of the aforementioned conifer aldehyde salicylate molecular device in the micro-area viscosity measurement of liquid nutrient, wherein the molar volume ratio of the conifer aldehyde salicylate molecular device to the liquid nutrient is 5-80 μmol: 0.005 L.

[0053] In this invention, the molar volume ratio of the pine aldehyde salicylate molecular device to the liquid nutrient is preferably 10-70 μmol: 0.005 L, more preferably 20-60 μmol: 0.005 L, and even more preferably 40-45 μmol: 0.005 L.

[0054] This invention involves the dehydration condensation of a natural salicylate derivative (methyl 5-aminosalicylate) and coniferaldehyde to obtain a conjugated coupling structure—coniferaldehyde-modified salicylate molecular device. This preparation process is achieved in one step, ultimately exhibiting a conjugated chromophore chemical structure with rotatable single and double bonds. In low-viscosity liquid nutrients, it can rotate freely, and the dissipation of excited-state energy is mainly through mechanical rotation, resulting in a weak or even unobservable apparent signal. In contrast, in high-viscosity liquid nutrients, rotation is suppressed, and the excited-state energy is mainly dissipated through radiative transitions, resulting in a stronger apparent signal that is observable to the naked eye. This enables in-situ measurement of the viscosity of micro-regions in liquid nutrients. The pine aldehyde salicylate molecular device, as a molecular tool, when added to liquid nutrient solutions, can determine the viscosity of the liquid nutrient solution based on the intensity of the emitted light signal. A stronger light signal indicates a thicker liquid nutrient solution, resulting in greater lag during flow, stronger coverage, adhesion, and coating properties, and allowing it to remain on the sprayed plant for a longer period after application. Conversely, a weaker light signal indicates better fluidity, spreadability, and penetration, allowing it to diffuse more effectively to the vicinity of the sprayed area and provide broader coverage. A schematic diagram illustrating the mechanism of the pine aldehyde salicylate molecular device for detecting the micro-area viscosity of liquid nutrient solutions is shown below. Figure 1 As shown.

[0055] The conifer aldehyde salicylate molecular device of this invention can be used as a signal switch to effectively measure the relative viscosity of micro-regions, which helps to improve the formulation process of liquid nutrients and enhance their viscosity control, thus better meeting customers' needs for liquid nutrients of different viscosities. The conifer aldehyde salicylate molecular device of this invention, based on conifer extract, can emit a strong light signal in the wavelength range of 340–680 nm under excitation by an external light source of 420 nm, with a peak wavelength of 508 nm. This allows for effective measurement of the micro-viscosity of liquid nutrients, providing a better solution to the problems of viscosity adjustment and the difficulty in measuring microscopic viscosity changes in liquid nutrients.

[0056] 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.

[0057] In this embodiment, the vacuum oven is model VO-53.

[0058] Example 1

[0059] 356.4 g of coniferaldehyde was dissolved in tetrahydrofuran and stirred at 500 rpm at 35 °C until homogeneous, yielding a coniferaldehyde solution with a concentration of 2 mol / L; 167.2 g of methyl 5-aminosalicylate was dissolved in methanol and stirred at 500 rpm at 35 °C until homogeneous, yielding a methyl 5-aminosalicylate solution with a concentration of 1 mol / L; 252 g of sodium bicarbonate was dispersed in anhydrous ethanol and stirred at 1200 rpm at 40 °C until homogeneous, yielding a dehydrating agent dispersion with a concentration of 3 mol / L.

[0060] First, the coniferaldehyde solution and the dehydrating agent dispersion were stirred at 400 rpm for 1 h at room temperature. Then, the stirring speed was increased to 1300 rpm, and the temperature was raised to 80 °C at a rate of 3 °C / min. After the temperature reached 80 °C, the methyl 5-aminosalicylate solution was added dropwise to the above mixture at a rate of 5 mL / min (the mixture was stirred at 1300 rpm during the dropwise addition). After the addition was completed, the mixture was stirred continuously at 1300 rpm for 12 h to carry out the dehydration condensation reaction and obtain the crude product.

[0061] The crude product was solvent-removed at -0.08 MPa, and then extracted with a mixture of ethyl acetate and purified water (volume ratio of ethyl acetate to purified water 3:1). The organic phase was collected and the solvent ethyl acetate was removed under reduced pressure to -0.08 MPa. The extracted product was mixed with ethanol (volume ratio of purified water to anhydrous ethanol 1:5), and the solid content of the mixture was 50 mg / mL. The mixture was allowed to stand at 4 °C for 20 h to crystallize. The resulting crystalline solid was mixed with ethanol (volume ratio of purified water to anhydrous ethanol 10:1), and the solid content of the mixture was 50 mg / mL. The mixture was centrifuged at 7000 r / min twice, with each centrifugation lasting 0.5 h. The centrifuged product was placed in a vacuum oven and dried at 70 °C for 16 h to obtain the coniferyl salicylate molecular device, denoted as MHMAAB.

[0062] The amount of coniferyl aldehyde salicylate molecular device obtained in this embodiment was 302.1 g, with a yield of 92.3%.

[0063] Mass spectrometry analysis was performed on the relative molecular mass of the pine aldehyde salicylate molecular device MHMAAB prepared in Example 1. The high-resolution mass spectrum of the pine aldehyde salicylate molecular device MHMAAB is shown below. Figure 2 As shown. By Figure 2 It is known that the relative molecular mass of the pine aldehyde salicylate molecular device MHMAAB is 327.32914 [M]. + The molecular formula of formula I is C 18 H 17NO5 has a theoretical relative molecular mass of 327.33600. In terms of relative molecular mass, it can be found that the pine aldehyde salicylate molecular device MHMAAB prepared in Example 1 is consistent with the target product formula I.

[0064] The chemical structure of the coniferyl aldehyde salicylate molecular device MHMAAB prepared in Example 1 was confirmed by nuclear magnetic resonance (NMR). The NMR spectrum of the coniferyl aldehyde salicylate molecular device MHMAAB is shown below. Figure 3 As shown. From Figure 3 It can be seen from this that 13 The CNMR (101MHz, DMSO-d6) values ​​were δ170.13, 164.68, 161.93, 149.11, 148.21, 144.82, 133.83, 127.83, 126.78, 124.10, 122.35, 120.18, 117.62, 116.71, 116.01, 113.89, 55.91, and 52.68. The carbon skeleton shift in its molecular structure was confirmed, and it can be identified as the coniferyl aldehyde salicylate molecular device described in Formula I of the target product.

[0065] Example 2

[0066] 178.2 g of coniferaldehyde was dissolved in tetrahydrofuran and stirred at 1000 rpm at 25 °C until homogeneous, yielding a 1 mol / L coniferaldehyde solution; 167.2 g of methyl 5-aminosalicylate was dissolved in methanol and stirred at 1000 rpm at 25 °C until homogeneous, yielding a 1 mol / L methyl 5-aminosalicylate solution; 84 g of sodium bicarbonate was dispersed in anhydrous ethanol and stirred at 1600 rpm at 25 °C until homogeneous, yielding a 1 mol / L dehydrating agent dispersion.

[0067] First, the coniferaldehyde solution and the dehydrating agent dispersion were stirred at 900 rpm for 0.1 h at room temperature. Then, the stirring speed was increased to 1800 rpm, and the temperature was raised to 70 °C at a rate of 1 °C / min. After the temperature reached 70 °C, the methyl 5-aminosalicylate solution was added dropwise to the above mixture at a rate of 2 mL / min (the mixture was stirred at 1800 rpm during the dropwise addition). After the addition was completed, the mixture was stirred continuously at 1800 rpm for 2 h to carry out the dehydration condensation reaction and obtain the crude product.

[0068] The crude product was solvent-removed at -0.07 MPa, and then extracted with a mixture of ethyl acetate and purified water (volume ratio of ethyl acetate to purified water 1:1). The organic phase was collected and the solvent ethyl acetate was removed by reducing the pressure to -0.07 MPa. The extracted product was mixed with ethanol (volume ratio of purified water to anhydrous ethanol 1:1), and the solid content of the mixture was 10 mg / mL. The mixture was allowed to stand at 1 °C for 10 h to crystallize. The resulting crystalline solid was mixed with ethanol (volume ratio of purified water to anhydrous ethanol 1:1), and the solid content of the mixture was 10 mg / mL. The mixture was centrifuged at 5000 r / min once for 1 h. The centrifuged product was placed in a vacuum oven and dried at 50 °C for 24 h to obtain the coniferyl salicylate molecular device, denoted as MHMAAB.

[0069] In this embodiment, 285.7 g of pine aldehyde salicylate molecular device was obtained, with a yield of 87.3%.

[0070] The high-resolution mass spectrometry and nuclear magnetic resonance results of the MHMAAB molecular device prepared in this embodiment are consistent with the results obtained in Example 1.

[0071] Example 3

[0072] 891.0 g of coniferaldehyde was dissolved in tetrahydrofuran and stirred at 300 rpm at 50 °C until homogeneous, yielding a 1 mol / L coniferaldehyde solution; 167.2 g of methyl 5-aminosalicylate was dissolved in methanol and stirred at 300 rpm at 50 °C until homogeneous, yielding a 3 mol / L methyl 5-aminosalicylate solution; 504 g of sodium bicarbonate was dispersed in anhydrous ethanol and stirred at 600 rpm at 60 °C until homogeneous, yielding a 6 mol / L dehydrating agent dispersion.

[0073] First, the coniferaldehyde solution and the dehydrating agent dispersion were stirred at 100 rpm for 2 hours at room temperature. Then, the stirring speed was increased to 900 rpm, and the temperature was raised to 110°C at a rate of 5°C / min. After the temperature reached 110°C, the methyl 5-aminosalicylate solution was added dropwise to the above mixture at a rate of 8 mL / min (the mixture was stirred at 900 rpm during the dropwise addition). After the addition was completed, the mixture was stirred continuously at 900 rpm for 24 hours to carry out the dehydration condensation reaction and obtain the crude product.

[0074] The crude product was solvent-removed at -0.09 MPa, and then extracted with a mixture of ethyl acetate and purified water (volume ratio of ethyl acetate to purified water 5:1). The organic phase was collected and the solvent ethyl acetate was removed under reduced pressure to -0.09 MPa. The extracted product was mixed with ethanol (volume ratio of purified water to anhydrous ethanol 1:10), and the solid content of the mixture was 80 mg / mL. The mixture was allowed to stand at 8 °C for 30 h to crystallize. The resulting crystalline solid was mixed with ethanol (volume ratio of purified water to anhydrous ethanol 10:1), and the solid content of the mixture was 80 mg / mL. The mixture was centrifuged at 10000 r / min three times, with each centrifugation lasting 0.1 h. The centrifuged product was placed in a vacuum oven and dried at 90 °C for 10 h to obtain the coniferyl salicylate molecular device, denoted as MHMAAB.

[0075] In this embodiment, 294.9 g of pine aldehyde salicylate molecular device was obtained, with a yield of 90.1%.

[0076] The high-resolution mass spectrometry and nuclear magnetic resonance results of the MHMAAB molecular device prepared in this embodiment are consistent with the results obtained in Example 1.

[0077] Example 4

[0078] 534.6 g of coniferaldehyde was dissolved in N,N-dimethylformamide and stirred at 500 rpm at 35 °C until homogeneous, yielding a coniferaldehyde solution with a concentration of 3 mol / L; 167.2 g of methyl 5-aminosalicylate was dissolved in methanol and stirred at 500 rpm at 35 °C until homogeneous, yielding a methyl 5-aminosalicylate solution with a concentration of 1 mol / L; 212 g of sodium carbonate was dispersed in propanol and stirred at 1200 rpm at 40 °C until homogeneous, yielding a dehydrating agent dispersion with a concentration of 2 mol / L; other conditions were the same as in Example 1.

[0079] Example 5

[0080] 712.8 g of coniferaldehyde was dissolved in ethyl acetate and stirred at 1000 rpm at 25 °C until homogeneous, yielding a coniferaldehyde solution with a concentration of 4 mol / L. 167.2 g of methyl 5-aminosalicylate was dissolved in methanol and stirred at 1000 rpm at 25 °C until homogeneous, yielding a methyl 5-aminosalicylate solution with a concentration of 1 mol / L. 200.24 g of potassium bicarbonate was dispersed in ethylene glycol and stirred at 1600 rpm at 25 °C until homogeneous, yielding a dehydrating agent dispersion with a concentration of 2 mol / L. Other conditions were the same as in Example 2.

[0081] The MHMAAB acetylated salicylate molecular device prepared in Example 1 was subjected to various spectroscopic tests, including viscosity sensitivity test, photostability test, pH stability test, and detection limit test.

[0082] (1) Viscosity sensitivity test of the MHMAAB molecular device prepared in Example 1: Solutions with different viscosities (1.0–956.0 cP) were obtained by adjusting different proportions of glycerol and purified water (the relationship between the viscosity of the solution and the glycerol content in the solution is shown in Table 1, and the sum of the volume fractions of glycerol and purified water remains unchanged). A tetrahydrofuran solution of the MHMAAB molecular device was added to the solution to make the concentration of MHMAAB 10 μmol / L. The external excitation wavelength was controlled at 420 nm, and the test was carried out at room temperature. The obtained spectrum is shown in the figure below. Figure 4 As shown.

[0083] Table 1. Relationship between solution viscosity and glycerol content in the solution

[0084]

[0085]

[0086] Depend on Figure 4 It can be seen that as the solution viscosity increases from 1.00 cP to 956.00 cP, the intensity of the observed light signal gradually increases. In particular, when the volume percentage of glycerol exceeds 50%, the intensity of the emitted light signal increases sharply until the volume percentage of purified water is 0% (the volume percentage of glycerol is 99%, and the volume percentage of tetrahydrofuran is 1%), at which point the light signal intensity reaches its maximum value. Compared with the solution system without added glycerol, the light signal intensity increases by up to 90.6 times.

[0087] A relationship between optical signal intensity and solution viscosity was established, with the solution viscosity ranging from 1.00 to 956.00 cP. After converting the optical signal intensity and solution viscosity into logarithmic functions, a straight line was fitted, which conforms to... -Hoffmann relation, specifically as follows Figure 5 As shown, where x is the viscosity sensitivity coefficient, R 2 The values ​​of the logarithmic function are shown in Table 2, representing the fitting coefficients.

[0088] Table 2. Correspondence between the logarithm of solution viscosity and the logarithm of fluorescence intensity

[0089]

[0090] Depend on Figure 5As shown in Table 2, MHMAAB exhibits a viscosity sensitivity coefficient of 0.65 and a fitting coefficient of 0.99, demonstrating high viscosity sensitivity. The results indicate that the MHMAAB molecular device of coniferyl aldehyde can be used as a molecular tool for measuring the micro-region viscosity of liquid nutrients. The strength of the apparent visual signal can be used to determine the viscosity, providing a solution for rapid, efficient, and visualized formulation.

[0091] (2) pH stability test of the pine aldehyde salicylate molecular device MHMAAB prepared in Example 1: 0.63 mg of the pine aldehyde salicylate molecular device MHMAAB was dissolved in fulvic acid, with a concentration of MHMAAB of 2 mmol / L. This solution was then added to buffer solutions with pH values ​​ranging from 3 to 10 (pH 3-5: ammonium dihydrogen phosphate / diammonium hydrogen phosphate mixture; pH 5-7: potassium dihydrogen phosphate / diammonium hydrogen phosphate mixture; pH 7-9: Tris buffer; pH 9-10: sodium bicarbonate / sodium carbonate mixture), ensuring that the concentration of MHMAAB in each buffer solution was 10 μmol / L. The change in optical signal intensity was tested at room temperature. The test results are as follows: Figure 6 As shown.

[0092] like Figure 6 It can be seen that the fluorescence intensity of the pine aldehyde salicylate molecular device MHMAAB does not change much in the pH range of 3 to 10, and it can exhibit good light signal release stability. It is not easily affected by pH fluctuations, and has high pH tolerance and universality.

[0093] (3) Photostability test of the coniferyl aldehyde salicylate molecular device MHMAAB prepared in Example 1: 1.26 mg of coniferyl aldehyde salicylate molecular device MHMAAB was dissolved in fulvic acid, with a concentration of MHMAAB of 4 mmol / L. Then, it was added to low-viscosity purified water (1.0 cP) and high-viscosity glycerol solution (glycerol volume fraction 99%, viscosity 956.0 cP), respectively, so that the concentration of MHMAAB in both solutions was 10 μmol / L. Under continuous irradiation from an external excitation light source at 420 nm, the change in its optical signal intensity over 60 min was tested. The test results are as follows: Figure 7 As shown in Table 3, the fluorescence test results are as follows.

[0094] Table 3 Fluorescence test results

[0095]

[0096] Depend on Figure 7As shown in Table 3, the MHMAAB methyl ester salicylate molecular device prepared in Example 1 can still maintain stable light signal release under continuous external light source irradiation. It has light signal stability in both high viscosity glycerol solution and low viscosity purified water, and is suitable for micro-area viscosity response of liquid nutrients. It will not be greatly affected even under long-term irradiation.

[0097] (4) Polarity tolerance test of the coniferyl aldehyde salicylate molecular device MHMAAB prepared in Example 1: 1.88 mg of the coniferyl aldehyde salicylate molecular device MHMAAB was dissolved in anhydrous ethanol, with a concentration of 6 mmol / L. This was then added to various conventional solvents of different polarities to achieve a concentration of 10 μmol / L for each MHMAAB. The light signal absorption characteristics under different polarity solvent atmospheres were tested. The above tests were conducted at room temperature, and the results are as follows: Figure 8 As shown.

[0098] Depend on Figure 8 It can be seen that in various solvents (toluene, dichloromethane, dimethyl sulfoxide, methanol, acetonitrile, tetrahydrofuran, ethyl acetate), the absorbance of the MHMAAB molecular device with coniferyl aldehyde is around 0.3, and the peak value of its absorption spectrum is around 420 nm. The results indicate that the MHMAAB molecular device is not sensitive to the polarity of the solution and is suitable for regulating and monitoring the viscosity changes of liquid nutrients containing multiple polar components.

[0099] Application Example 1

[0100] 1.57 mg of the methyl methacrylate (MHMAAB) molecular device prepared in Example 1 was dissolved in anhydrous ethanol to obtain an MHMAAB solution with a concentration of 5 mmol / L. This solution was then added to liquid nutrient 1, liquid nutrient 2, and liquid nutrient 3, respectively, with each liquid nutrient containing 10 μmol / L of MHMAAB. The emission spectra of the above-mentioned liquid nutrient 1 (General Hydroponics Flora Series), liquid nutrient 2 (CANNATerraAqua), and liquid nutrient 3 (AdvancedNutrients Sensi Grow) with added MHMAAB were then measured at room temperature with an external excitation source of 420 nm. The resulting emission spectra are shown below. Figure 9 As shown in Table 4, the optical signal intensity and viscosity of different mixed solutions are as follows.

[0101] Table 4. Light signal intensity and viscosity of different liquid nutrients

[0102] Liquid nutrient solution 1 478.1 52.0 Liquid nutrient solution 2 831.7 120.2 Liquid nutrient solution 3 1555.9 314.8

[0103] Depend on Figure 9 As shown in Table 4, the viscosities of the three liquid nutrients differ significantly, leading to substantial differences in light signal intensity. Liquid nutrient 1 exhibits the lowest light signal intensity, indicating a thinner consistency; its viscosity is 52.0 cP. Liquid nutrient 2 shows a moderate light signal intensity, indicating a slightly improved consistency; its overall consistency is moderate, with a viscosity of 120.2 cP. Liquid nutrient 3 shows a further increase in light signal intensity, indicating a higher overall consistency; its viscosity is 314.8 cP. These different viscosities indicate significant differences in their final spraying and retention performance. Higher viscosity allows the liquid nutrient to remain on the leaves for a longer time, while lower viscosity liquid nutrient exhibits better spraying and coverage efficiency, enabling better wetting of more leaf surface.

[0104] The above test results show that the methyl salicylate molecular device (MHMAAB) prepared by the present invention based on coniferaldehyde and salicylate derivatives can exhibit light signals of different intensities for liquid nutrients with different micro-region viscosities. Its peak emission wavelength is 508nm, which is bright green light, and it has a visual monitoring effect.

[0105] As shown in the above embodiments, this invention provides a coniferyl aldehyde salicylate molecular device, its preparation method, and its application. The coniferyl aldehyde and salicylate derivatives of this invention are conjugated in a one-step process to obtain a functional molecule containing a chromophore, namely the coniferyl aldehyde salicylate molecular device (MHMAAB). The coniferyl aldehyde salicylate molecular device of this invention has an alternating single and double bond conjugated structure, exhibiting different rotational states in solution atmospheres of different viscosities, which are then converted into light signals and released, enabling rapid, efficient, and visual detection of the viscosity of micro-regions in liquid nutrients. Especially for liquid nutrients containing a large amount of pseudoplastic polymers, traditional detection methods mostly complete the measurement through shearing processes, which are difficult to handle the viscosity measurement of shear-thinned fluids. The molecular device of this invention can present the viscosity in situ through varying light signal intensity, without consuming a large amount of test samples. Various test results show that the coniferyl aldehyde salicylate molecular device of this invention has a high sensitivity coefficient (x = 0.65), good pH stability, and excellent photostability. Furthermore, the coniferyl aldehyde salicylate molecular device has strong solvent tolerance, making it suitable for sensing subtle changes in the viscosity of micro-regions in liquid nutrients. Furthermore, the preparation process of pine aldehyde salicylate molecular device (MHMAAB) does not involve the addition of any toxic catalysts or heavy metal ions, making it green, environmentally friendly, and easy to operate. It also has a high final yield, and the raw materials are derived from natural products, which are abundant and have high added value, making it suitable for large-scale industrial production applications.

[0106] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A pine aldehyde-modified salicylate molecular device, characterized in that, The structural formula of the coniferyl aldehyde salicylate molecular device is: Formula I.

2. The method for preparing the pine aldehyde salicylate molecular device according to claim 1, characterized in that, It includes the following steps: A coniferaldehyde solution, a dehydrating agent dispersion, and a salicylate derivative solution were mixed, and the mixture underwent a dehydration condensation reaction to obtain a coniferaldehyde-modified salicylate molecular device. In the salicylate derivative solution, the salicylate derivative is methyl 5-aminosalicylate.

3. The preparation method according to claim 2, characterized in that, The concentration of the coniferaldehyde solution is 1~5 mol / L, the concentration of the dehydrating agent dispersion is 1~6 mol / L, and the concentration of the salicylate derivative solution is 1~3 mol / L.

4. The preparation method according to claim 3, characterized in that, In the mixture, the molar ratio of salicylate derivative, coniferaldehyde and dehydrating agent is 1:1~5:1~6.

5. The preparation method according to claim 2 or 4, characterized in that, In the coniferaldehyde solution, the solvent is one or more of methanol, tetrahydrofuran, ethanol, N,N-dimethylformamide, ethyl acetate, and dimethyl sulfoxide; in the salicylate derivative solution, the solvent is an alcohol solvent.

6. The preparation method according to claim 5, characterized in that, The solvent in the dehydrating agent dispersion is one or more of methanol, ethanol, propanol, n-butanol, ethylene glycol, 1,2-propanediol, 1,3-propanediol and 1,3-butanediol, and the dehydrating agent is one or more of sodium carbonate, cesium carbonate, aluminum hydroxide, sodium bicarbonate, potassium carbonate, potassium bicarbonate and magnesium hydroxide.

7. The preparation method according to claim 6, characterized in that, The specific mixing process is as follows: after mixing the coniferaldehyde solution and the dehydrating agent dispersion, the salicylate derivative solution is added dropwise. After the addition is completed, the mixture is stirred continuously to obtain a mixed solution. The rate of addition of the salicylate derivative solution is 2~8 mL / min.

8. The preparation method according to claim 7, characterized in that, The process for mixing coniferaldehyde solution and dehydrating agent dispersion is as follows: first, stir at low speed at room temperature, then heat up while stirring at high speed. The low speed stirring rate is 100~900 rpm and the time is 0.1~2h; the high speed stirring rate is 900~1800 rpm and the temperature is raised to 70~110℃ at a rate of 1~5℃ / min. The stirring speed is 900~1800 rpm, and the stirring time is 2~24h.

9. The preparation method according to claim 7, characterized in that, The product obtained from the dehydration condensation reaction was sequentially extracted, crystallized, centrifuged, and dried to obtain a pine aldehyde salicylate molecular device.

10. The application of the coniferyl aldehyde salicylate molecular device according to claim 1 in the micro-area viscosity measurement of liquid nutrients, characterized in that, The molar volume ratio of the pine aldehyde salicylate molecular device to the liquid nutrient is 5~80µmol:0.005L.

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