Anisaldehyde hippuric acid molecular top and its preparation method and application

Abstract

The application provides an anisaldehyde hippuric acid molecular top and a preparation method and application thereof, and belongs to the technical field of detection of gibberellic acid liquid preparation. The anisaldehyde hippuric acid molecular top has a unique configuration of a rigid aromatic ring rotor and an amide bond flexible support shaft, can convert micro-viscosity changes into visual light signal output, and releases light signal intensity that regularly increases with the increase of micro-viscosity, so that the dilution degree of the gibberellic acid liquid preparation can be observed in real time and accurately controlled. The sensitive coefficient of the MBABG to viscosity is high (x=0.65), the conjugated system formed by the amide bond and the aromatic ring in the molecular structure of the MBABG gives the MBABG excellent chemical stability, the MBABG can resist the complex environment of multiple components such as thickening agents, surfactants and pH regulators in the gibberellic acid liquid preparation, and can exist stably for a long time.

Description

Technical Field

[0001] This invention relates to the field of gibberellic acid liquid preparation detection technology, and in particular to a molecular gyroscope for anisaldehyde-modified hippuric acid, its preparation method and application. Background Technology

[0002] Gibberellic acid liquid formulations are a class of agricultural plant growth regulators with gibberellic acid (GA3) as the core active ingredient and specific viscosity characteristics. They are widely used to regulate crop growth and development. Their viscosity characteristics directly determine the dispersion stability of the gibberellic acid active ingredient, the uniformity of spray application, and the persistence of target adhesion, which have a key impact on the final regulatory effect.

[0003] As a high-value-added agricultural functional fluid, gibberellic acid liquid formulations are mostly colorless to pale yellow and transparent. Their viscosity gradient directly relates to the core application performance of the formulation: higher viscosity gibberellic acid liquid formulations (such as high-viscosity suspensions and gels) have better storage stability, slower sedimentation rates of active ingredient particles, and stronger adhesion persistence and better lag on the target surface, which helps prolong the action time; however, they also have the drawback of poor flowability, leading to uneven atomization during spraying, and insufficient penetration and mixing uniformity of the gibberellic acid active ingredient within the formulation system, limiting wettability and spreading ability. Conversely, lower viscosity gibberellic acid liquid formulations (such as soluble concentrates and low-viscosity suspensions) have excellent flowability, good spray atomization effect, higher penetration of active ingredient and system mixing efficiency, and better brushability and spreading efficiency on crop surfaces; however, they suffer from weak adhesion persistence and poor setting ability, are easily washed away by rainwater, and the active ingredient particles tend to settle during storage, with insufficient lag leading to a shortened action period. It is evident that, to adapt to the needs of different crop cultivation scenarios and application methods, it is necessary to precisely control the viscosity characteristics of gibberellic acid liquid formulations and develop formulations with differentiated viscosity gradients to meet diversified market demands. Traditional measurement methods mainly rely on instruments such as rotational viscometers and capillary viscometers. However, these methods have significant limitations in the viscosity detection of gibberellic acid liquid formulations: firstly, the required sample volume is large, resulting in material waste for the high-value gibberellic acid active ingredient; secondly, the testing cycle is long, making it difficult to meet the real-time quality control requirements of large-scale production processes; thirdly, and most importantly, it cannot be adapted to gibberellic acid liquid formulations containing a large amount of pseudoplastic components (such as xanthan gum-stabilized suspensions)—these formulations exhibit a typical shear-thinning effect during flow, shearing, and adsorption. The mechanical shearing action of traditional viscometers disrupts the steady-state equilibrium of the formulation's microenvironment, leading to a significant deviation between the measured results and the actual micro-region viscosity, a sharp decrease in accuracy, and consequently, an inability to provide reliable data support for formulation optimization. Therefore, developing an in-situ, visualized, real-time, and efficient method for measuring the viscosity of gibberellic acid liquid formulations has become an urgent need in the industry.

[0004] Compared to traditional fluid viscosity detection techniques, molecular-level photochemical detection technology can convert the viscosity changes of gibberellic acid liquid formulations into light signal intensity gradients in real time through the light signal response of functional molecules. It boasts core advantages such as excellent visualization, in-situ static measurement, and preservation of the formulation's microenvironmental stability. Currently, such molecular-level tools are scarce and urgently need development. Summary of the Invention

[0005] The purpose of this invention is to provide a molecular gyroscope for anisaldehyde-modified hippuric acid, its preparation method, and its application, in order to solve the problems of long viscosity detection cycle and large deviation between measurement results and actual micro-area viscosity in existing technologies for gibberellic acid liquid preparations.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides a molecular gyroscope for anisaldehyde-modified hippuric acid, the structure of which is shown in (Ⅰ):

[0007] (I).

[0008] The present invention provides a method for preparing the above-mentioned p-anisaldehyde hippuric acid molecular gyroscope, comprising the following steps: mixing an inorganic salt solution and a p-anisaldehyde solution, and then adding a hippuric acid derivative solution to react and obtain a p-anisaldehyde hippuric acid molecular gyroscope. The structural formula of the hippuric acid derivative is as follows: .

[0009] Preferably, the concentration of the inorganic salt solution is 1-6 mol / L; the inorganic salt in the inorganic salt solution includes one or more of sodium carbonate, sodium bicarbonate, potassium carbonate, calcium hydroxide, and magnesium carbonate; the solvent of the inorganic salt solution is prepared by mixing an organic solvent and purified water, wherein the volume ratio of the organic solvent to purified water is 4-10:1; the organic solvent includes one or more of ethanol, methanol, acetone, ethyl acetate, ethylene glycol, propylene glycol, N,N-dimethylformamide, and dimethyl sulfoxide.

[0010] Preferably, the concentration of the p-anisaldehyde solution is 1-5 mol / L; the solvent of the p-anisaldehyde solution includes one or more of tetrahydrofuran, ethyl acetate, dimethyl sulfoxide, acetonitrile, acetone, N,N-dimethylformamide and ethylene glycol.

[0011] Preferably, the concentration of the hippuric acid derivative solution is 1-3 mol / L; the solvent of the hippuric acid derivative solution is prepared by mixing an alcohol solvent and N,N-dimethylformamide, wherein the alcohol solvent includes one or more of methanol, ethanol, propanol, ethylene glycol, 1,2-propanediol and 1,3-propanediol.

[0012] Preferably, the volume ratio of the alcohol solvent to N,N-dimethylformamide is 2 to 6:1.

[0013] Preferably, the molar ratio of the hippuric acid derivative, p-anisaldehyde, and inorganic salt is 1:1 to 5:1 to 6.

[0014] Preferably, the hippuric acid derivative solution is added by uniform spraying at a rate of 1-5 mL / min, and the temperature is increased to 80-100°C at a rate of 1-5°C / min during the spraying process.

[0015] Preferably, the reaction continues for 2-8 hours after the uniform spraying is completed.

[0016] The present invention also provides an application of the above-described molecular gyroscope for anisaldehyde-modified hippuric acid in monitoring or detecting the micro-region viscosity of gibberellic acid liquid preparations.

[0017] The beneficial effects of this invention are: (1) The molecular tool of the present invention, anisaldehyde-modified hippuric acid molecular gyroscope (MBABG), is constructed by coupling anisaldehyde with a natural amino acid derivative hippuric acid through natural aromatic aldehyde compounds, forming a functional molecule with a typical molecular gyroscope topology. This achieves precise integration of the aromatic conjugated skeleton of anisaldehyde and the amide bond structure of hippuric acid. The required raw materials, anisaldehyde and hippuric acid, are both natural / semi-natural products widely found in nature, with abundant sources and environmentally friendly properties, giving MBABG typical environmentally degradable characteristics. At the same time, its natural derivative structure can enhance the environmental compatibility of the formulation, which is highly compatible with the green and environmentally friendly requirements of gibberellic acid liquid formulation, achieving synergistic effect of functional response and formulation performance enhancement, and improving the comprehensive application value of the compound formulation.

[0018] (2) The MBABG of the present invention can specifically respond to the micro-region viscosity of gibberellic acid liquid formulations, providing core technical support for the efficient control of formulation processes of gibberellic acid liquid formulations (such as suspensions, solubles, etc.). The anisaldehyde-modified hippuric acid molecular gyroscope (MBABG), with its unique configuration of a rigid aromatic ring rotor and a flexible support shaft of amide bonds, can convert micro-region viscosity changes into visual light signal output. The intensity of the released light signal increases regularly with the increase of micro-region viscosity, which is convenient for real-time observation and precise control of the viscosity of gibberellic acid liquid formulations. MBABG exhibits a high viscosity sensitivity (x=0.65). The conjugated system formed by the amide bond and aromatic ring in its molecular structure endows it with excellent chemical stability, enabling it to withstand the complex environment of multiple components such as thickeners, surfactants, and pH adjusters in gibberellic acid liquid formulations, achieving long-term stability. Furthermore, its chromogenic wavelength peak is at 425 nm, exhibiting typical bright blue light with high visualization and excellent photostability. It also possesses good solvent polarity tolerance, with a detection limit as low as 1.021 cP and a Stokes shift of 113.2 nm, effectively avoiding excitation light interference. It is suitable for precise monitoring of micro-region viscosity and formulation adjustment reference in gibberellic acid liquid formulations.

[0019] (3) The MBABG of the present invention can realize in-situ visual monitoring of the preparation process of gibberellic acid liquid formulations, filling the gap in the traditional detection method that is difficult to perform in-situ, real-time and efficient viscosity detection of gibberellic acid liquid formulations. At the same time, in view of the problem that gibberellic acid liquid formulations (especially suspensions) are prone to detection deviation due to the shear thinning effect caused by the presence of a large amount of pseudoplastic fluid (such as xanthan gum stabilized system), MBABG does not need to rely on shear action to sense viscosity changes, and can effectively avoid such defects.

[0020] (4) The MBABG of the present invention is prepared by one-step condensation coupling method. The process is simple, fast and efficient with excellent yield and has the potential for large-scale industrial production. Its chemical process is simple and easy to implement, with high raw material conversion rate and low process loss. The post-processing mainly uses alcohol solvents and purified water for purification and separation, without the generation of harmful pollutants. The post-processing product is green and environmentally friendly and will not have a negative impact on the environment. It realizes the high-value reconstruction of natural products and provides a new path for the green synthesis of functional molecules for gibberellic acid liquid preparations. It has significant industrial application prospects and environmental benefits. Attached Figure Description

[0021] Figure 1 This is a diagram illustrating the mechanism of action of the fumonisin-based hippuric acid molecular gyroscope tool of this invention. Figure 2 The image shows the carbon NMR spectrum of the anisaldehyde-modified hippuric acid molecular gyroscope (MBABG) of Example 1. Figure 3This is a high-resolution mass spectrum of the molecular gyroscope (MBABG) of anisaldehyde hippuric acid in Example 1; Figure 4 The fluorescence spectra of the anisaldehyde-modified hippuric acid molecular gyroscope (MBABG) in different ratios of glycerol / purified water mixed solutions of Example 1 are shown. Figure 5 The image shows the logarithmic function fitting plot of the optical signal intensity of the anisaldehyde-modified hippuric acid molecular gyroscope (MBABG) in Example 1 in glycerol / purified water mixed solutions of different ratios as a function of solution viscosity. Figure 6 pH tolerance of anisaldehyde-modified hippuric acid molecular gyroscope (MBABG) in Example 1; Figure 7 The absorption spectra of anisaldehyde-modified hippuric acid molecular gyroscope (MBABG) in different polarity solutions are shown in Example 1. Figure 8 The detection limit diagram for anisaldehyde hippuric acid molecular gyroscope (MBABG) in Example 1 is shown. Figure 9 The Stokes displacement diagram of the anisaldehyde-modified hippuric acid molecular gyroscope (MBABG) of Example 1 is shown. Figure 10 The fluorescence spectra of the anisaldehyde-modified hippuric acid molecular gyroscope (MBABG) of Example 1 in different commercially available gibberellic acid liquid formulation samples are shown. Detailed Implementation

[0022] This invention provides a molecular gyroscope for anisaldehyde-modified hippuric acid, the structure of which is shown in (Ⅰ):

[0023] (I).

[0024] The present invention provides a method for preparing the above-mentioned p-anisaldehyde hippuric acid molecular gyroscope, comprising the following steps: mixing an inorganic salt solution and a p-anisaldehyde solution, and then adding a hippuric acid derivative solution to react and obtain a p-anisaldehyde hippuric acid molecular gyroscope. The structural formula of the hippuric acid derivative is as follows: .

[0025] In this invention, the concentration of the inorganic salt solution is 1~6 mol / L, specifically 1 mol / L, 2 mol / L, 3 mol / L, 5 mol / L, or 6 mol / L; the inorganic salt in the inorganic salt solution includes one or more of sodium carbonate, sodium bicarbonate, potassium carbonate, calcium hydroxide, and magnesium carbonate; the solvent of the inorganic salt solution is prepared by mixing an organic solvent and purified water, wherein the volume ratio of the organic solvent to purified water is 4~10:1, specifically 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, or 10:1; the organic solvent includes one or more of ethanol, methanol, acetone, ethyl acetate, ethylene glycol, propylene glycol, N,N-dimethylformamide, and dimethyl sulfoxide.

[0026] In this invention, the concentration of the anisaldehyde solution is 1~5 mol / L, specifically 1 mol / L, 2 mol / L, 3 mol / L, 4 mol / L, or 5 mol / L; the solvent of the anisaldehyde solution includes one or more of tetrahydrofuran, ethyl acetate, dimethyl sulfoxide, acetonitrile, acetone, N,N-dimethylformamide, and ethylene glycol.

[0027] In this invention, the preparation of the anisaldehyde solution is carried out by ultrasonic-assisted mechanical stirring, wherein the ultrasonic power is 80~500W, specifically 80W, 100W, 150W, 200W, 300W, 400W, or 500W; the stirring speed is 800~2000rpm, specifically 800rpm, 1200rpm, 1400rpm, 1600rpm, 1800rpm, or 2000rpm; and the stirring time is 20~60min, specifically 20min, 30min, 40min, 50min, or 60min.

[0028] In this invention, the inorganic salt solution and the p-anisaldehyde solution are directly mixed at a temperature of 30-50°C, specifically 30°C, 35°C, 40°C, 45°C, or 50°C; the stirring rate is 500-1200 rpm, specifically 500 rpm, 600 rpm, 800 rpm, 1000 rpm, or 1200 rpm; and the mixing time is 20-60 min, specifically 20 min, 30 min, 40 min, 50 min, or 60 min.

[0029] In this invention, the concentration of the hippuric acid derivative solution is 1~3 mol / L, specifically 1 mol / L, 2 mol / L, or 3 mol / L; the solvent of the hippuric acid derivative solution is prepared by mixing an alcohol solvent and N,N-dimethylformamide, wherein the alcohol solvent includes one or more of methanol, ethanol, propanol, ethylene glycol, 1,2-propanediol, and 1,3-propanediol.

[0030] In this invention, the volume ratio of the alcohol solvent to N,N-dimethylformamide is 2 to 6:1, specifically 2:1, 3:1, 4:1, 5:1, or 6:1.

[0031] In this invention, the hippuric acid derivative solution is prepared by ultrasonic-assisted mechanical stirring, wherein the ultrasonic power is 50~300W, specifically 50W, 100W, 150W, 200W, 250W, or 300W; the stirring speed is 600~1600rpm, specifically 600rpm, 800rpm, 1000rpm, 1100rpm, 1200rpm, 1400rpm, or 1600rpm; the stirring time is 10~50min, specifically 12min, 20min, 30min, 40min, or 48min; and the mixing temperature is 30~50℃, specifically 30℃, 35℃, 40℃, 45℃, or 50℃.

[0032] In this invention, the molar ratio of the hippuric acid derivative, p-anisaldehyde, and inorganic salt is 1:1 to 5:1 to 6, specifically 1:2:3, 1:1:1, or 1:5:6.

[0033] In this invention, the hippuric acid derivative solution is added by uniform spraying at a rate of 1-5 mL / min, specifically 1 mL / min, 2 mL / min, 3 mL / min, 4 mL / min, or 5 mL / min. During the spraying process, the temperature is increased to 80-100°C at a rate of 1-5°C / min, specifically 80°C, 85°C, 90°C, 95°C, or 100°C.

[0034] In this invention, the reaction continues for 2 to 8 hours after the uniform spraying ends, specifically for 2 hours, 4 hours, 6 hours, or 8 hours.

[0035] In this invention, after the reaction is completed, the reaction is preferably subjected to vacuum distillation, filtration and washing, dispersion and nitrogen blowing, and freeze drying.

[0036] In this invention, the pressure of the vacuum distillation is -0.07 to -0.09 MPa, specifically -0.07 MPa, -0.08 MPa, or -0.09 MPa, and the rotation speed is 50 to 300 rpm, specifically 50 rpm, 100 rpm, 150 rpm, 200 rpm, 250 rpm, or 300 rpm.

[0037] In this invention, the filtration and washing involves washing the product of vacuum distillation in a mixed solution of ethanol and purified water, followed by vacuum filtration. The volume ratio of ethanol to purified water is 4-8:1, specifically 4:1, 5:1, 6:1, 7:1, or 8:1. The flow rate during vacuum filtration is 1-4 mL / s, specifically 1 mL / s, 2 mL / s, 3 mL / s, or 4 mL / s. The vacuum pressure range during vacuum filtration is -0.07 to -0.09 MPa, specifically -0.07 MPa, -0.08 MPa, or -0.09 MPa.

[0038] In this invention, the dispersive nitrogen blowing involves placing the filtered washing product in a mixed solution of ethanol and purified water, followed by nitrogen blowing. The volume ratio of ethanol to purified water is 1:1 to 4, specifically 1:1, 1:2, 1:3, or 1:4. The nitrogen blowing temperature is 30 to 50°C, specifically 30°C, 40°C, or 50°C. The nitrogen flow rate is 3 to 10 L / min, specifically 3 L / min, 6 L / min, 8 L / min, or 10 L / min. The nitrogen blowing process is performed using a multi-tube vortex mixer until the solution is removed.

[0039] In this invention, the freeze-drying temperature is -30 to -10°C, specifically -30°C, -20°C, or -10°C; the time is 14 to 28 hours, specifically 14 hours, 16 hours, 20 hours, 24 hours, 26 hours, or 28 hours.

[0040] The present invention also provides an application of the above-described molecular gyroscope for anisaldehyde-modified hippuric acid in monitoring or detecting the micro-region viscosity of gibberellic acid liquid preparations.

[0041] In this invention, the physical viscosity of the gibberellic acid liquid preparation is monitored using a molecular gyroscope solution of anisaldehyde-modified hippuric acid, wherein the solvent of the molecular gyroscope solution of anisaldehyde-modified hippuric acid is ethylene glycol. The molecular gyroscope solution of anisaldehyde-modified hippuric acid is added to the gibberellic acid liquid preparation, and the concentration of the molecular gyroscope solution of anisaldehyde-modified hippuric acid is controlled at 10 μM.

[0042] In this invention, the excitation wavelength for measuring the optical signal intensity is 280~350nm.

[0043] 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.

[0044] Example 1

[0045] At 40°C, 194.19 g of p-aminohippuric acid (1 mol) was added to a mixed solvent of methanol and N,N-dimethylformamide (volume ratio of methanol to N,N-dimethylformamide 5:1). The ultrasonic power was controlled at 150 W and the stirring speed at 1100 rpm. The mixture was stirred at a constant temperature for 30 min to dissolve the mixture and obtain a p-aminohippuric acid solution with a concentration of 2 mol / L (solution 1).

[0046] At 25°C, 272.30 g of p-anisaldehyde (2 mol) was added to tetrahydrofuran and dissolved using ultrasonic-assisted mechanical stirring. The ultrasonic power was controlled at 200 W and the stirring speed at 1200 rpm. The mixture was stirred and dispersed at a constant temperature for 40 min to obtain a p-anisaldehyde solution with a concentration of 2 mol / L (solution 2). Subsequently, 318.00 g of sodium carbonate (3 mol) was added to a mixed solvent of ethanol and purified water (volume ratio of ethanol to purified water 5:1). After stirring and dissolving, an inorganic salt solution with a concentration of 3 mol / L was obtained. The inorganic salt solution and solution 2 were mixed at a constant temperature of 40°C and the stirring speed was controlled at 800 rpm. The mixture was stirred for 40 min to obtain an alkaline mixed solution of p-anisaldehyde.

[0047] Solution 1 was added dropwise to the alkaline mixed solution of anisaldehyde using a uniform spray method, with the spray rate controlled at 3 mL / min. During the spraying process, the system temperature was raised to 90℃ at a heating rate of 3℃ / min, and the system was continuously stirred and heated simultaneously, with the stirring rate maintained at 1500 rpm. After the addition of solution 1 was completed, the system was stirred at a constant temperature of 90℃ for 4.0 h.

[0048] After the reaction, the product was subjected to vacuum distillation, filtration and washing, dispersion and nitrogen blowing, and freeze drying in sequence. During vacuum distillation, the reaction product was placed in a rotary evaporator and the solvent was removed under reduced pressure at -0.08 MPa, with the rotation speed controlled at 150 rpm. The solid obtained from vacuum distillation was placed in a mixed solution of ethanol and purified water (volume ratio of ethanol to purified water 5:1) and filtered using two layers of neutral fast filter paper at a flow rate of 2 mL / s and a vacuum pressure of -0.08 MPa. The washing was repeated three times. The filtered and washed solid was then redispersed in a mixed solution of ethanol and purified water (volume ratio of ethanol to purified water 1:2) and placed in a multi-tube vortex mixer. The temperature was controlled at 40℃ and the nitrogen flow rate at 6 L / min, with continuous nitrogen blowing until the solvent was completely removed. Finally, the nitrogen-blown solid was placed in a freeze dryer and dried at -20℃ for 24 h to obtain a molecular tool of p-anethaldehyde-modified p-aminohippuric acid (MBABG), with a yield of 289.84 g and a yield of 92.8%.

[0049] The product was characterized by carbon nuclear magnetic resonance spectroscopy. 13C NMR (600 MHz, DMSO-d6) δ 172.2, 168.3, 162.5, 159.8, 152.3, 131.8, 130.6, 130.2, 128.7, 122.3, 114.5, 57.0, 36.8, confirming the shifts in the carbon skeleton in its molecular structure. Furthermore, its molecular weight was determined by high-resolution liquid chromatography-mass spectrometry, with results as follows: Figure 3 As shown, the test data is as follows: HR-MS (ESI): calcd for C 17 H 16 N2O4 ([M]) + 312.32500, found: 312.32509. Analysis by NMR and mass spectrometry confirmed that the prepared product was the target compound (4-((4-methoxybenzyl)amino)benzoyl)glycine (MBABG).

[0050] Example 2

[0051] At 30°C, 194.19 g of p-aminohippuric acid (1 mol) was added to a mixed solvent of methanol and N,N-dimethylformamide (volume ratio of methanol to N,N-dimethylformamide 2:1). The ultrasonic power was controlled at 50 W and the stirring speed at 600 rpm. The mixture was stirred at a constant temperature for 12 min to dissolve the mixture and obtain a 1 mol / L p-aminohippuric acid solution (solution 1).

[0052] At 30°C, 136.15 g of anisaldehyde (1 mol) was added to tetrahydrofuran and dissolved using ultrasonic-assisted mechanical stirring at a power of 80 W and a stirring speed of 800 rpm. The mixture was stirred and dispersed at a constant temperature for 20 min to obtain a 1 mol / L anisaldehyde solution (solution 2). Subsequently, 105.99 g of sodium carbonate (1 mol) was added to a mixed solvent of ethanol and purified water (volume ratio of ethanol to purified water 4:1) and stirred to dissolve, resulting in a 1 mol / L inorganic salt solution. The inorganic salt solution and solution 2 were mixed at a constant temperature of 30°C with a stirring speed of 500 rpm for 60 min to obtain an alkaline mixed solution of anisaldehyde.

[0053] Solution 1 was added dropwise to the alkaline mixed solution of anisaldehyde using a uniform spray method, with the spray rate controlled at 1 mL / min. During the spraying process, the system temperature was raised to 80℃ at a heating rate of 1℃ / min, and the system was continuously stirred and heated simultaneously, with the stirring rate maintained at 1000 rpm. After the addition of solution 1 was completed, the system was stirred at a constant temperature of 80℃ for 8.0 h.

[0054] After the reaction, the product was subjected to vacuum distillation, filtration and washing, dispersion and nitrogen blowing, and freeze drying in sequence. During vacuum distillation, the reaction product was placed in a rotary evaporator and the solvent was removed under reduced pressure at -0.09 MPa, with the rotation speed controlled at 50 rpm. The solid obtained from vacuum distillation was placed in a mixed solution of ethanol and purified water (volume ratio of ethanol to purified water 4:1) and filtered using a single layer of neutral fast filter paper at a flow rate of 1 mL / s and a vacuum pressure of -0.09 MPa. The washing was repeated three times. The filtered and washed solid was then redispersed in a mixed solution of ethanol and purified water (volume ratio of ethanol to purified water 1:1) and placed in a multi-tube vortex mixer. The temperature was controlled at 30℃ and the nitrogen flow rate at 3 L / min, with continuous nitrogen blowing until the solvent was completely removed. Finally, the nitrogen-blown solid was placed in a freeze dryer and dried at -30℃ for 14 h to obtain a molecular tool of p-anisaldehyde-modified p-aminohippuric acid (MBABG), with a yield of 281.31 g and a yield of 90.5%.

[0055] The nuclear magnetic resonance spectrum and high-resolution mass spectrometry results of the anisaldehyde-modified hippuric acid molecular tool MBABG obtained in Example 2 are consistent with the results obtained in Example 1.

[0056] Example 3

[0057] At 50°C, 194.19 g of p-aminohippuric acid (1 mol) was added to a mixed solvent of methanol and N,N-dimethylformamide (volume ratio of methanol to N,N-dimethylformamide 6:1). The ultrasonic power was controlled at 300 W and the stirring speed at 1600 rpm. The mixture was stirred at a constant temperature for 48 min to dissolve the mixture and obtain a 3 mol / L p-aminohippuric acid solution (solution 1).

[0058] At 50°C, 680.75 g of p-anisaldehyde (5 mol) was added to tetrahydrofuran and dissolved using ultrasonic-assisted mechanical stirring at a power of 500 W and a stirring speed of 2000 rpm. The mixture was stirred and dispersed at a constant temperature for 60 min to obtain a 5 mol / L p-anisaldehyde solution (solution 2). Subsequently, 636.00 g of sodium carbonate (6 mol) was added to a mixed solvent of ethanol and purified water (volume ratio of ethanol to purified water 10:1) and stirred to dissolve, resulting in a 6 mol / L inorganic salt solution. The inorganic salt solution and solution 2 were mixed at a constant temperature of 50°C with a stirring speed of 1200 rpm for 60 min to obtain an alkaline mixed solution of p-anisaldehyde.

[0059] Solution 1 was added dropwise to the alkaline mixed solution of anisaldehyde using a uniform spray method, with the spray rate controlled at 5 mL / min. During the spraying process, the system temperature was raised to 100℃ at a heating rate of 5℃ / min, and the system was continuously stirred and heated simultaneously, with the stirring rate maintained at 2000 rpm. After the addition of solution 1 was completed, the system was stirred at a constant temperature of 100℃ for 2.0 h.

[0060] After the reaction, the product was subjected to vacuum distillation, filtration and washing, dispersion under nitrogen blowing, and freeze-drying in sequence. During vacuum distillation, the reaction product was placed in a rotary evaporator and the solvent was removed under reduced pressure at -0.07 MPa, with the rotation speed controlled at 300 rpm. The solid obtained from vacuum distillation was placed in a mixed solution of ethanol and purified water (ethanol to purified water volume ratio 8:1) and filtered using three layers of neutral fast filter paper, with the filtration flow rate controlled at 4 mL / s and the vacuum pressure at -0.07 MPa. The washing was repeated three times. The filtered and washed solid was then redispersed in a mixed solution of ethanol and purified water (ethanol to purified water volume ratio 1:4) and placed in a multi-tube vortex mixer. The temperature was controlled at 50℃ and the nitrogen flow rate at 10 L / min, with continuous nitrogen blowing until the solvent was completely removed. Finally, the nitrogen-blown solid was placed in a freeze dryer and dried at -10℃ for 28 h to obtain the p-anethaldehyde-modified p-aminohippuric acid molecular tool (MBABG), with a yield of 285.15. g, yield was 91.3%.

[0061] The NMR spectrum and high-resolution mass spectrometry results of the anisaldehyde-modified hippuric acid molecular tool MBABG obtained in Example 3 were consistent with those obtained in Example 1.

[0062] Performance testing: (1) Viscosity response test: Test solution preparation: Weigh 1.25 mg of the p-anisaldehyde hippuric acid molecular gyroscope prepared in Example 1, dissolve it in 4 mL of ethanol, and disperse it by ultrasonication until completely dissolved to prepare a molecular gyroscope solution with a concentration of 1 mmol / L. During the testing phase, the final concentration of the molecular gyroscope in the system was controlled to be 10 μM by gradient dilution, and the total volume of all test systems was kept constant at 3 mL.

[0063] A series of test systems were constructed by adjusting the volume ratio of glycerol to purified water, with the volume fraction of glycerol set to 0%, 10%, 30%, 50%, 70%, and 99%, ensuring that the total volume of each system was 3 mL. The tests were conducted at room temperature, using 320 nm as the excitation wavelength, and the fluorescence intensity was measured as a function of the system viscosity. Figure 4 ), and perform linear fitting analysis on viscosity sensitivity ( Figure 5It is known that the viscosity of purified water at room temperature is only 1.0 cP, while the viscosity of glycerol is as high as 956.0 cP. The viscosity of the mixture of the two can be continuously controlled by volume ratio. The test results are as follows. Figure 4 As shown, the fluorescence intensity emitted by the gyroscope of anisaldehyde-modified p-aminohippuric acid molecules showed a significant increasing trend with the gradual increase of the test system viscosity; when the system viscosity was close to that of pure glycerol, its fluorescence intensity at the characteristic emission wavelength of 425 nm was 78.7 times higher than that of the pure purified water system. Figure 5 The linear fitting results show that this molecular gyroscope has excellent viscosity response sensitivity. The logarithm of its fluorescence intensity exhibits a good linear correlation with the logarithm of the system viscosity, indicating that the fluorescence intensity increases regularly with increasing viscosity. Based on the Forster-Hoffmann equation, the viscosity sensitivity of this molecular gyroscope is 0.65, and the coefficient of determination (R²) for linear fitting is 0.98. In summary, the molecular gyroscope for anisaldehyde-modified p-aminohippuric acid prepared in this invention possesses excellent viscosity response performance and high sensitivity, making it suitable for responsive detection of micro-region viscosity in gibberellic acid liquid formulation systems. It can provide accurate data support for formulation optimization design by real-time monitoring of changes in the viscosity of gibberellic acid liquid formulations, significantly improving formulation development efficiency.

[0064] (2) pH tolerance test: 1.56 mg of the p-anisaldehyde hippuric acid molecular gyroscope prepared in Example 1 was weighed and dissolved in an appropriate amount of ethanol to prepare a molecular gyroscope stock solution with a concentration of 5 mmol / L. Subsequently, this stock solution was added to a series of buffer solutions simulating the actual pH environment of the gibberellic acid liquid formulation. The specific buffer system design was as follows: potassium dihydrogen phosphate / dipotassium hydrogen phosphate mixed buffer at pH 3.0–5.0, Tris buffer at pH 7.0–9.0, and sodium bicarbonate / sodium carbonate mixed buffer at pH 9.0–12.0. The final concentration of the molecular gyroscope in all test systems was adjusted to 10 μM. The change in light signal intensity was measured at room temperature, and the test results are as follows: Figure 6 As shown.

[0065] Depend on Figure 6Test results show that the molecular gyroscope for anisaldehyde-modified hippuric acid exhibits weak and stable fluorescence signal release characteristics within a wide pH range of 3.0 to 12.0, with minimal fluctuations in light signal intensity, demonstrating excellent pH tolerance. This characteristic is highly compatible with the application requirements of gibberellic acid liquid formulations: the conventional pH control range for gibberellic acid liquid formulations (such as soluble and suspending agents) is generally 3.0 to 9.0, and slight pH fluctuations may occur during production, storage, and application. The molecular gyroscope of this invention can maintain the stability of the light signal within this pH fluctuation range, and its response detection accuracy to the viscosity of the formulation micro-region will not be affected by changes in environmental pH. This provides crucial support for its reliable application as a molecular-level viscosity detection tool in the formulation optimization and quality control of gibberellic acid formulations.

[0066] (3) Solvent polarity atmosphere tolerance assessment: Using the p-anisaldehyde-modified p-aminohippuric acid molecular gyroscope liquid used in the aforementioned viscosity response test, a series of test systems with different polar solvents were constructed to verify the influence of solvent polarity on the photophysical properties of the molecular gyroscope. The solvents selected for the tests covered common multi-polar components and related solvents found in gibberellic acid liquid formulations, specifically including: tetrahydrofuran, dichloromethane, ethyl acetate, acetonitrile, ethanol, N,N-dimethylformamide, methanol, and dimethyl sulfoxide. The total volume of all test systems was strictly controlled to 3 mL, and the final concentration of the molecular gyroscope was kept constant at 10 μM. Its absorption spectra in different polar solvents were measured, and the results are as follows: Figure 7 As shown. By Figure 7 The test results show that the absorbance of the anisaldehyde-modified p-aminohippuric acid molecular gyroscope remains stable around 0.75 in various solvent systems with different polarities, exhibiting minimal fluctuations. Furthermore, the characteristic peaks of its absorption spectrum are concentrated around 320 nm, without significant peak shift. These results indicate that the molecular gyroscope possesses good inertness to polar atmospheres in the solution.

[0067] This characteristic is highly compatible with the application scenarios of gibberellic acid liquid formulations: gibberellic acid liquid formulations (such as soluble and suspending agents) are usually multi-component mixtures containing polar solvents such as purified water, methanol, and ethylene glycol. Some formulations may also contain weakly polar additives such as toluene and ethyl acetate, resulting in a wide range of solvent polarities. The molecular gyroscope for anisaldehyde-modified p-aminohippuric acid can maintain stable photophysical properties in such complex polar environments, without changes in absorbance or characteristic peak positions due to solvent polarity differences, thus avoiding interference with the accurate detection of the viscosity of the formulation's micro-regions. This advantage ensures the reliable application of this molecular gyroscope throughout the entire process of gibberellic acid liquid formulation development and production process quality control, providing a stable signal basis for real-time monitoring of formulation viscosity.

[0068] (4) Determination of the detection limit of the molecular gyroscope for anisaldehyde-modified hippuric acid prepared in Example 1: 1.87 mg of the p-anisaldehyde-modified p-aminohippuric acid molecular gyroscope prepared in Example 1 was weighed and dissolved in an appropriate amount of ethanol to prepare a molecular gyroscope solution with a concentration of 6 mmol / L. During the testing phase, the mother liquor was serially diluted to a final concentration of 10 μmol / L, and then added to purified water-glycerol mixtures with different viscosity gradients (simulating the viscosity range of low-viscosity liquid formulations of gibberellic acid). The volume fractions of glycerol and their corresponding viscosities in the mixtures were set as follows: 0% (1.0 cP), 1% (1.2 cP), 5% (1.5 cP), 10% (1.7 cP), and 15% (2.5 cP), respectively. All tests were conducted at room temperature, and linear fitting curves of the detection limit of the p-anisaldehyde-modified p-aminohippuric acid molecular gyroscope were plotted. Figure 8 ).Depend on Figure 8 The test results show that, in the solution system within the aforementioned extremely low viscosity range, the viscosity value of the anisaldehyde-modified p-aminohippuric acid molecular gyroscope exhibits a good linear correlation with the logarithm of the fluorescence signal intensity, with a linear fitting coefficient of determination (R²) of 0.99. This indicates that the molecular gyroscope demonstrates excellent response stability and linearity in the low viscosity range. Based on this linear relationship, the viscosity detection limit of this molecular gyroscope is calculated to be 1.021 cP.

[0069] This low detection limit characteristic is highly compatible with the application requirements of gibberellic acid liquid formulations: the mainstream dosage forms of gibberellic acid liquid formulations, such as soluble and low-viscosity suspensions, typically have an initial viscosity in the low viscosity range of 1.0~5.0 cP, and may experience slight viscosity fluctuations during formulation preparation and storage (such as uneven dispersion of active ingredients, changes in the synergistic effect of adjuvants, etc.). The molecular gyroscope for anisaldehyde-modified p-aminohippuric acid can accurately sense minute viscosity changes within the low viscosity range, providing highly sensitive signal support for formulation optimization of gibberellic acid liquid formulations (such as fine-tuning the amount of thickener) and quality control during the production process (such as real-time monitoring of formulation homogeneity). This effectively avoids problems such as decreased formulation stability and deviations in application effect caused by ignoring minute fluctuations in the low viscosity range, significantly improving the R&D and production efficiency of gibberellic acid liquid formulations.

[0070] Application Example 1

[0071] 2.19 mg of the p-anisaldehyde hippuric acid molecular gyroscope prepared in Example 1 was weighed and dissolved in an appropriate amount of ethanol to prepare a molecular gyroscope liquid with a concentration of 7 mmol / L. Subsequently, this stock solution was added to three gibberellic acid liquid formulation systems simulating different formulations, as follows: gibberellic acid liquid formulation 1 (Sichuan Longmang Fusheng 4% gibberellic acid liquid formulation), gibberellic acid liquid formulation 2 (Guoguang Dingyue 3% gibberellic acid liquid formulation), and gibberellic acid liquid formulation 3 (Xinruifeng gibberellic acid emulsifiable concentrate); the final concentration of the molecular gyroscope in all test systems was precisely controlled to 10 μmol / L.

[0072] Three gibberellic acid liquid formulations exhibited significant viscosity differences due to variations in formulation (different gibberellic acid concentrations and thickener dosages), leading to a clear gradient in the fluorescence signal intensity emitted by the molecular gyroscope for anisaldehyde-modified p-aminohippuric acid. Specifically, gibberellic acid liquid formulation 1 showed the lowest fluorescence signal intensity, indicating a thinner system consistency, with a viscosity of 67.8 cP. Gibberellic acid liquid formulation 2 showed a moderate fluorescence signal intensity, corresponding to a moderate system consistency, with a viscosity of 136.2 cP. Gibberellic acid liquid formulation 3 showed a significantly higher fluorescence signal intensity, corresponding to a thicker system consistency, with a viscosity of 468.3 cP. The molecular gyroscope for anisaldehyde-modified hippuric acid provided by this invention can visually distinguish gibberellic acid liquid formulations of different consistencies through gradient changes in fluorescence signal intensity. Its characteristic emission wavelength peak is 425 nm, exhibiting a bright indigo blue color, resulting in high visual recognition and excellent monitoring performance. This characteristic makes it highly promising for application in the field of gibberellic acid liquid formulations: on the one hand, it can be used for rapid screening in the formulation development stage, visually judging the impact of different thickener dosages and active ingredient concentrations on system viscosity through visual signals, thereby improving the efficiency of formulation optimization; on the other hand, it can be applied to quality control in the production process, monitoring the viscosity uniformity of the formulation in real time, avoiding fluctuations in application effect (such as uneven spraying, differences in adhesion, etc.) caused by batch-to-batch viscosity differences, and providing reliable molecular-level monitoring tools to support the efficient development and stable production of gibberellic acid liquid formulations.

[0073] As shown in the above embodiments, this invention provides a molecular gyroscope for anisaldehyde-modified hippuric acid, its preparation method, and its application. This molecular gyroscope is constructed from natural aromatic aldehyde derivative anisaldehyde and natural amino acid derivative hippuric acid through directional conjugated coupling. The raw materials are all derived from natural / semi-natural products, making them abundant and of high added value. The preparation process employs a one-step condensation coupling process, which is highly efficient, simple, environmentally friendly, and produces no harmful pollutants. The final product has excellent yield and low cost (effective detection can be achieved with milligram-level dosage), making it suitable for large-scale industrial production. The molecular gyroscope for anisaldehyde-modified hippuric acid provided by this invention can exhibit light signal output of different intensities in gibberellic acid liquid formulation systems of different consistencies, enabling rapid, efficient, and in-situ visual detection of the viscosity (diluteness / lightness) of micro-regions in gibberellic acid liquid formulations. It is particularly suitable for the viscosity detection of gibberellic acid liquid formulations (such as suspensions, solubles, etc.) containing pseudoplastic fluids (such as xanthan gum stabilized systems). The detection process does not rely on mechanical rotation and shearing action, providing core technical support for in-situ and real-time monitoring of formulation viscosity. The molecular gyroscope for anisaldehyde-modified hippuric acid exhibits excellent comprehensive performance: First, it has a high viscosity sensitivity coefficient (x=0.65), responding sensitively to micro-region viscosity changes in gibberellic acid liquid formulations; second, it possesses good pH stability and excellent photostability, tolerating pH fluctuations and light environments during the production, storage, and application of gibberellic acid liquid formulations, ensuring the stability of the detection signal; third, it has strong tolerance to solvents of different polarities, adapting to multi-polar solvent systems such as purified water, ethanol, and methanol in gibberellic acid liquid formulations, without interference to detection accuracy due to solvent polarity differences; fourth, it has a detection limit as low as 1.021 cP, accurately capturing minute viscosity fluctuations in low-viscosity liquid formulations of gibberellic acid (such as soluble concentrates). In summary, the molecular gyroscope for anisaldehyde-modified hippuric acid possesses significant application potential and core advantages in the field of gibberellic acid liquid formulations due to its unique structural advantages, excellent performance, and green and efficient preparation characteristics. It can be widely used in viscosity control and optimization during the formulation development stage, real-time monitoring of viscosity uniformity during the production process, and quality control of finished products. It can effectively improve the R&D efficiency and production stability of gibberellic acid liquid formulations, providing reliable molecular-level monitoring tools to support the precise and efficient development of gibberellic acid liquid formulations.

[0074] 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 molecular gyroscope for anisaldehyde-modified hippuric acid, characterized in that, The structure of the gyroscope containing anisaldehyde hippuric acid is shown in (Ⅰ): （Ⅰ）。 2. The method for preparing the molecular gyroscope of anisaldehyde-modified hippuric acid according to claim 1, characterized in that, The process includes the following steps: mixing an inorganic salt solution and a p-anisaldehyde solution, then adding a hippuric acid derivative solution to react and obtain a p-anisaldehyde-modified hippuric acid molecular gyroscope. The structural formula of the hippuric acid derivative is as follows: .

3. The method for preparing anisaldehyde-modified hippuric acid molecular gyroscope according to claim 2, characterized in that, The concentration of the inorganic salt solution is 1-6 mol / L; the inorganic salt in the inorganic salt solution includes one or more of sodium carbonate, sodium bicarbonate, potassium carbonate, calcium hydroxide, and magnesium carbonate; the solvent of the inorganic salt solution is prepared by mixing an organic solvent and purified water, wherein the volume ratio of the organic solvent to purified water is 4-10:1; the organic solvent includes one or more of ethanol, methanol, acetone, ethyl acetate, ethylene glycol, propylene glycol, N,N-dimethylformamide, and dimethyl sulfoxide.

4. The method for preparing anisaldehyde-modified hippuric acid molecular gyroscope according to claim 2 or 3, characterized in that, The concentration of the p-anisaldehyde solution is 1~5 mol / L; the solvent of the p-anisaldehyde solution includes one or more of tetrahydrofuran, ethyl acetate, dimethyl sulfoxide, acetonitrile, acetone, N,N-dimethylformamide and ethylene glycol.

5. The method for preparing anisaldehyde-modified hippuric acid molecular gyroscope according to claim 4, characterized in that, The concentration of the hippuric acid derivative solution is 1~3 mol / L; the solvent of the hippuric acid derivative solution is prepared by mixing an alcohol solvent and N,N-dimethylformamide, wherein the alcohol solvent includes one or more of methanol, ethanol, propanol, ethylene glycol, 1,2-propanediol and 1,3-propanediol.

6. The method for preparing anisaldehyde-modified hippuric acid molecular gyroscope according to claim 5, characterized in that, The volume ratio of the alcohol solvent to N,N-dimethylformamide is 2~6:

1.

7. The method for preparing anisaldehyde-modified hippuric acid molecular gyroscope according to claim 2, 3, or 5, characterized in that, The molar ratio of the hippuric acid derivative, p-anisaldehyde, and inorganic salt is 1:1~5:1~6.

8. The method for preparing anisaldehyde-modified hippuric acid molecular gyroscope according to claim 7, characterized in that, The hippuric acid derivative solution is added by uniform spraying at a rate of 1-5 mL / min, and the temperature is increased to 80-100℃ at a rate of 1-5℃ / min during the spraying process.

9. The method for preparing anisaldehyde-modified hippuric acid molecular gyroscope according to claim 8, characterized in that, After the uniform spraying is completed, the reaction continues for 2-8 hours.

10. The application of the molecular gyroscope for anisaldehyde-modified hippuric acid as described in claim 1 in monitoring or detecting the micro-region viscosity of gibberellic acid liquid preparations.

Images