Conjugated molecular tools of piperidine-coupled vitamins and methods of making and using the same

Abstract

The application provides a piperidine-coupled vitamin conjugate molecular tool and a preparation method and application thereof, and belongs to the technical field of gel detection. The application comprises the following steps: mixing a quinone vitamin solution and a nitrile compound solution to perform a nitrilation reaction to obtain a quinone vitamin nitrile compound; mixing a 4-piperidine-1-yl-benzaldehyde solution and the quinone vitamin nitrile compound solution to perform a condensation reaction to obtain the piperidine-coupled vitamin conjugate molecular tool. The piperidine-coupled vitamin conjugate molecular tool provided by the application has excellent chemical and light stability, can guarantee the release intensity of a light signal in different viscosity solution atmospheres, and can maintain good stability in different polarity and different pH solution atmospheres, is not easily disturbed, has a viscosity sensitivity coefficient of 0.80, and is very suitable for being used for the detection and sensing of a solution micro-zone viscosity. The application can realize efficient, rapid and quick 'turn-on' characteristics, so that the application range of a cold compress gel and the suitable group are wider.

Description

Technical Field

[0001] This invention relates to the field of gel detection technology, and more particularly to a conjugated molecular tool for piperidine-coupled vitamins, its preparation method, and its application. Background Technology

[0002] With the rapid development of modern medical technology and the continuous pursuit of health, many affordable and effective topical medications have entered countless households. Medical cooling gels, as a functional topical medication, play a significant role in many situations, especially in relieving pain, reducing swelling and pain, and lowering fever. Some gels can even promote wound healing, reduce inflammation and edema, and reduce local blood circulation. In fact, the main components of many gels are hydrophilic polymers (hyaluronic acid, carbomer, etc.), purified water, glycerin, etc., with the remainder being plant extracts and various pharmaceuticals required for some functions. It can be seen that gels, as a key component of functional carriers, extensively load or encapsulate various plant extracts or pharmaceuticals to exert their efficacy. The degree of spread and wetting on the skin directly affects the actual therapeutic effect, and these properties are closely related to the physical parameter of gel viscosity. In fact, different patients have different needs for gels. Patients with more severe skin lesions may require thicker gels, allowing plant extracts or medications to remain on the skin surface better and longer, resulting in better efficacy. Conversely, patients with milder skin lesions may require looser gels, which spread more easily on the skin surface and are more volatile, allowing for easier penetration into the skin. Therefore, manufacturers can improve the user experience and expand the application scenarios of gels by adjusting their viscosity, providing a better treatment experience for various consumers. The control of viscosity is related to the micro-viscosity of the gel, and its magnitude is closely related to the gel's wetting, spreading, and internal drug release properties. In traditional methods, viscosity is a macroscopic physical parameter that can only be measured using various devices, requiring large sample volumes and not suitable for visualization and rapid, efficient detection. Therefore, there is an urgent need to develop suitable molecular tools to measure micro-viscosity at the microscopic level.

[0003] Photochemical technology is a sensitive, real-time imaging, and visual detection method. This type of method can achieve signal conversion between light and viscosity using molecular tools, enabling rapid detection and efficient assessment of gel viscosity, even for very small samples (mL / mg level). Therefore, developing a molecular tool for the application of in cooling gels is of great significance, as it is crucial for refining gel formulation processes and developing products suitable for patients with different skin conditions. Summary of the Invention

[0004] The purpose of this invention is to provide a conjugated molecular tool for piperidine-coupled vitamins, so as to solve the technical problem that viscosity is difficult to accurately measure during gel preparation in the prior art.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0006] This invention provides a conjugated molecular tool for piperidine-coupled vitamins, wherein the conjugated molecular tool for piperidine-coupled vitamins is:

[0007]

[0008] This invention also provides a method for preparing the conjugated molecular tool of piperidine-coupled vitamins, comprising the following steps:

[0009] (1) A quinone vitamin solution is mixed with a nitrile solution to carry out a nitrification reaction to obtain quinone vitamin nitrile;

[0010] (2) The conjugated molecular tool of the piperidine-coupled vitamin is obtained by mixing 4-piperidine-1-ylbenzaldehyde solution with quinone vitamin nitrile solution and carrying out a condensation reaction.

[0011] Preferably, the concentration of the quinone vitamin solution in step (1) is 1-20M, and the solvent of the quinone vitamin solution is one or more of methanol, tetrahydrofuran, ethanol, N,N-dimethylformamide, ethyl acetate and dimethyl sulfoxide.

[0012] The chemical structural formula of the quinone vitamin is as follows:

[0013]

[0014] Preferably, the concentration of the nitrile solution in step (1) is 1 to 100 M, and the solvent of the nitrile solution is one or more of methanol, tetrahydrofuran, ethanol, N,N-dimethylformamide, ethyl acetate and dimethyl sulfoxide.

[0015] The nitrile is malononitrile;

[0016] The molar ratio of quinone vitamins to nitrile compounds is 1:1 to 50.

[0017] Preferably, the temperature of the nitrification reaction in step (1) is 30 to 120°C, and the time of the nitrification reaction is 0.5 to 32 h.

[0018] Preferably, the concentration of the 4-piperidine-1-ylbenzaldehyde solution in step (2) is 1 to 200 mol / L, and the solvent of the 4-piperidine-1-ylbenzaldehyde solution is one or more of methanol, ethanol, n-butanol, propanol, isopropanol, n-pentanol, ethylene glycol, diethylene glycol, 1,2-propanediol, 1,3-propanediol and 1,3-butanediol.

[0019] Preferably, the concentration of the quinone vitamin nitrile solution in step (2) is 1 to 80 mol / L, and the solvent of the quinone vitamin nitrile solution is one or more of methanol, ethanol, n-butanol, propanol, isopropanol, n-pentanol, ethylene glycol, diethylene glycol, 1,2-propanediol, 1,3-propanediol and 1,3-butanediol.

[0020] Preferably, the molar ratio of 4-piperidin-1-ylbenzaldehyde to quinone vitamins is 1 to 30:1.

[0021] Preferably, the temperature of the condensation reaction in step (2) is 20 to 90°C, and the time of the condensation reaction is 1 to 78 hours.

[0022] This invention provides the application of the conjugated molecular tool of piperidine-coupled vitamins in the detection of gel viscosity.

[0023] The present invention has the following beneficial effects:

[0024] This invention provides a conjugated molecular tool for piperidine-coupled vitamins. The molecular structure contains freely rotating conjugated structures under different external conditions. In low-viscosity gels, it undergoes mechanical rotation, dissipating excited-state energy and exhibiting a weak surface signal, indicating good spreadability, wetting, and penetration on the skin surface. In high-viscosity gels, mechanical rotation is inhibited, and excited-state energy returns to the ground state primarily through radiative transitions, releasing a stronger surface signal. This indicates that the gel has a longer residence time on the skin, enabling prolonged release of the loaded plant extracts or drugs, providing patients with a more lasting treatment experience and better therapeutic effects. Specifically, as follows... Figure 1 As shown, this "molecular switch" can release light signal intensities of varying degrees as the gel viscosity changes, thereby allowing for precise control of the relative viscosity of the gel, which is of great significance for the process formulation and coating research of gels.

[0025] The conjugated molecular tool for piperidine-coupled vitamins provided by this invention is named 2,2'-(2-(3-methylbut-2-en-1-yl)-3-(4-(piperidin-1-yl)styryl)naphthalene-1,4-diethylenediamide)dimalononitrile (MPND), with the molecular formula C. 34 H 29N5, with a relative molecular mass of 507.64, is a molecular probe obtained by further coupling a natural aromatic piperidine derivative (4-piperidin-1-ylbenzaldehyde) and a quinone vitamin derivative (vitamin K2(5)). The resulting molecular tool is a pale yellow powder, easily soluble in various common solvents such as ethyl acetate, ethanol, N,N-dimethylformamide, methanol, and dimethyl sulfoxide. The molecular tool, after being linked to the quinone vitamin derivative, exhibits good conjugation, effectively extending the signal emission wavelength and enhancing the mechanical rotatability of the tool. This significantly increases the tool's sensitivity to viscosity, enabling effective monitoring of the viscosity of micro-regions in cold compress gels. Furthermore, this type of molecular tool is a fluffy powder with low hygroscopicity, allowing for long-term storage and preventing deterioration. It also exhibits good photostability under various polarities, pH conditions, and prolonged irradiation, and its sensitivity to viscosity changes is far greater than that caused by other factors, making it particularly suitable for measuring the viscosity of micro-regions in medical cold compress gels.

[0026] The emission wavelength range of the piperidine-coupled vitamin conjugated molecular tool of the present invention is mainly concentrated in the range of 550-850 nm, with a peak wavelength around 707 nm. When this molecular tool is added to cold compress gels of different viscosities, it can release light signals of different intensities, thereby determining its relative viscosity and providing effective support for the precise adjustment of the viscosity of the cold compress gel.

[0027] The piperidine-coupled vitamin conjugated molecular tool provided by this invention has excellent chemical and photostability. It can ensure the release intensity of light signals in solution atmospheres of different viscosities and maintain good stability in solution atmospheres of different polarities and pH. It is not easily affected by interference and has a viscosity sensitivity coefficient of 0.80, making it very suitable for the detection and sensing of viscosity in micro-regions of solutions.

[0028] The piperidine-coupled vitamin conjugated molecular tool provided by this invention can be used for viscosity sensing during the preparation of medical cold compress gel, achieving efficient, rapid, and quick "turn-on" characteristics. It can observe the consistency adjustment effect of the cold compress gel based on the relative intensity of light signal release, effectively control its preparation process, and make the application scope and suitable groups of the cold compress gel wider.

[0029] This invention also provides a method for preparing the conjugated molecular tool of piperidine-coupled vitamins, comprising the following steps: (1) mixing a quinone vitamin solution with a nitrile solution to perform a nitrification reaction to obtain a quinone vitamin nitrile; (2) mixing a 4-piperidin-1-ylbenzaldehyde solution with a quinone vitamin nitrile solution to perform a condensation reaction to obtain the conjugated molecular tool of piperidine-coupled vitamins. This invention uses the natural product aromatic piperidine derivative 4-piperidin-1-ylbenzaldehyde and a quinone vitamin nitrile to couple. Quinone vitamin derivatives are widely found in bioactive natural products and possess broad pharmacological activity. They are a highly advantageous molecular framework in functional molecule synthesis, not only being abundant and environmentally friendly, but also using inexpensive vitamin derivatives. The two-step preparation method is simple and easy to implement, using conventional solvents, resulting in high yields and suitability for large-scale preparation. Attached Figure Description

[0030] Figure 1 This is a schematic diagram illustrating the mechanism of the piperidine-coupled vitamin conjugated molecular tool provided by the present invention for detecting the viscosity of cold compress gel;

[0031] Figure 2 High-resolution mass spectrum of the conjugated molecular tool for piperidine-coupled vitamins prepared in Example 1;

[0032] Figure 3 The nuclear magnetic resonance spectrum of the conjugated molecular tool for piperidine-coupled vitamins prepared in Example 1;

[0033] Figure 4 Emission spectra of the conjugated molecular tool of piperidine-coupled vitamins prepared in Example 1 in different commercially available cold compress gels;

[0034] Figure 5 Fluorescence spectra of the conjugated molecular tool of piperidine-coupled vitamins prepared in Example 1 in different alcohol / water mixed solutions;

[0035] Figure 6 The logarithmic function of fluorescence intensity versus viscosity value for the piperidine-coupled vitamin conjugated molecular tool prepared in Example 1;

[0036] Figure 7 Photostability test results of the conjugated molecular tool of piperidine-coupled vitamins prepared in Example 1 in solution atmospheres of different viscosities;

[0037] Figure 8 Absorption spectra of the conjugated molecular tool of piperidine-coupled vitamins prepared in Example 1 in solutions of different polarities;

[0038] Figure 9 The emission spectra of the conjugated molecular tool of piperidine-coupled vitamins prepared in Example 1 in solutions of different pH values. Detailed Implementation

[0039] This invention provides a conjugated molecular tool for piperidine-coupled vitamins, wherein the conjugated molecular tool for piperidine-coupled vitamins is:

[0040]

[0041] This invention also provides a method for preparing the conjugated molecular tool of piperidine-coupled vitamins, comprising the following steps:

[0042] (1) A quinone vitamin solution is mixed with a nitrile solution to carry out a nitrification reaction to obtain quinone vitamin nitrile;

[0043] (2) The conjugated molecular tool of the piperidine-coupled vitamin is obtained by mixing 4-piperidine-1-ylbenzaldehyde solution with quinone vitamin nitrile solution and carrying out a condensation reaction.

[0044] In this invention, the concentration of the quinone vitamin solution in step (1) is preferably 1-20M, more preferably 5-15M, and even more preferably 8-12M. The solvent of the quinone vitamin solution is preferably one or more of methanol, tetrahydrofuran, ethanol, N,N-dimethylformamide, ethyl acetate, and dimethyl sulfoxide.

[0045] The chemical structural formula of the quinone vitamin is as follows:

[0046]

[0047] The quinone vitamin is K2(5) vitamin.

[0048] In this invention, the concentration of the nitrile solution in step (1) is preferably 1 to 100 M, more preferably 25 to 75 M, and even more preferably 40 to 60 M. The solvent of the nitrile solution is preferably one or more of methanol, tetrahydrofuran, ethanol, N,N-dimethylformamide, ethyl acetate, and dimethyl sulfoxide.

[0049] The nitrile is preferably malononitrile;

[0050] The molar ratio of quinone vitamins to nitrile compounds is preferably 1:1 to 50, more preferably 1:10 to 40, and even more preferably 1:20 to 30.

[0051] In this invention, the specific steps of mixing in step (1) are as follows:

[0052] Under magnetic stirring, the nitrile solution is added dropwise to the quinone vitamin solution. The magnetic stirring speed is preferably 300–1200 rpm, more preferably 500–1100 rpm, and even more preferably 600–1000 rpm. The temperature during addition is preferably 25°C, and the addition rate is preferably 1 mL / min–60 mL / min, more preferably 20 mL / min–40 mL / min, and even more preferably 25 mL / min–35 mL / min.

[0053] After the addition is complete, the magnetic stirring rate and temperature in the mixture are increased to the stirring rate and temperature in the nitrification reaction.

[0054] In this invention, the magnetic stirring rate of the nitrification reaction in step (1) is preferably 1200-2200 rpm, more preferably 1500-1900 rpm, and even more preferably 1600-1800 rpm.

[0055] In this invention, the temperature of the nitrification reaction in step (1) is preferably 30-120°C, more preferably 50-100°C, and even more preferably 70-90°C. The time of the nitrification reaction is preferably 0.5-32.0 h, more preferably 10-22 h, and even more preferably 15-17 h.

[0056] In this invention, after the nitrification reaction is completed, the product is sequentially subjected to vacuum distillation, precipitation, purification, and drying. The vacuum distillation pressure is preferably -0.09 MPa to -0.08 MPa, more preferably -0.085 MPa. The precipitation is achieved by placing the vacuum distillation product in a mixed solution of ethanol and purified water, and then allowing the mixed solution to stand at a low temperature. The mass-to-volume ratio of the precipitation system is preferably 1 mg to 30 mg: 10 mL, which allows a large amount of crystals to precipitate. The volume ratio of ethanol to purified water is preferably 1:1 to 20, more preferably 1:5 to 15, and even more preferably 1:8 to 12. The low temperature is preferably 1 to 10 °C, more preferably 2 to 9 °C, and even more preferably 3 to 8 °C. The standing time is preferably 1 to 36 h, more preferably 10 to 25 h, and even more preferably 15 to 20 h. The purification process involves removing the solvent through filtration, preferably using slow-speed filter paper with 1-4 layers. During filtration, the product is washed repeatedly 1-3 times with ethanol and purified water, maintaining the same volume ratio as in the precipitation step. The product is then purified using a silica gel column, preferably with a mixture of dichloromethane and methanol in a volume ratio of 1-30:1. The silica gel powder used is preferably 100-600 mesh. The drying process involves dispersing the purified product in ethanol and purified water in a volume ratio of 1:1-80, controlling the solid content to 1 mg / mL-10 mg / mL, and then placing it in a freeze dryer at a temperature of -20 to 0°C for 1-32 hours.

[0057] In this invention, the concentration of the 4-piperidine-1-ylbenzaldehyde solution in step (2) is preferably 1 to 200 mol / L, more preferably 50 to 150 mol / L, and even more preferably 80 to 120 mol / L. The solvent of the 4-piperidine-1-ylbenzaldehyde solution is preferably one or more of methanol, ethanol, n-butanol, propanol, isopropanol, n-pentanol, ethylene glycol, diethylene glycol, 1,2-propanediol, 1,3-propanediol, and 1,3-butanediol.

[0058] In this invention, the use of alcohol solvents can effectively promote the reaction to proceed to the right.

[0059] In this invention, the concentration of the quinone vitamin nitrile solution in step (2) is preferably 1-80 mol / L, 20-60 mol / L, and more preferably 30-40 mol / L. The solvent of the quinone vitamin nitrile solution is preferably one or more of methanol, ethanol, n-butanol, propanol, isopropanol, n-pentanol, ethylene glycol, diethylene glycol, 1,2-propanediol, 1,3-propanediol, and 1,3-butanediol.

[0060] In this invention, the molar ratio of 4-piperidin-1-ylbenzaldehyde to quinone vitamins is preferably 1 to 30:1, more preferably 5 to 25:1, and even more preferably 10 to 20:1.

[0061] In this invention, the mixing method in step (2) is preferably to add a quinone vitamin nitrile solution dropwise to a 4-piperidin-1-yl-benzaldehyde solution under magnetic stirring. The stirring speed is preferably 100-2500 rpm, more preferably 200-2000 rpm, and even more preferably 300-1800 rpm. The stirring time is preferably 1-24 h, more preferably 2-20 h, and even more preferably 3-18 h. The dropping rate is preferably 1 drop / 10 s to 1 drop / s, more preferably 1 drop / 2 s to 1 drop / 8 s, and even more preferably 1 drop / 3 s to 1 drop / 6 s.

[0062] In this invention, after mixing is completed, the magnetic stirring rate and temperature of the mixing system are adjusted to the magnetic stirring rate and temperature of the condensation reaction.

[0063] In this invention, the stirring rate of the condensation reaction is preferably 100-1000 r / min, more preferably 400-700 r / min, and even more preferably 500-600 r / min.

[0064] In this invention, the temperature of the condensation reaction in step (2) is preferably 20-90°C, more preferably 40-70°C, and even more preferably 50-60°C. The time of the condensation reaction is preferably 1-78h, more preferably 20-58h, and even more preferably 30-48h.

[0065] The present invention also provides the application of the conjugated molecular tool of piperidine-coupled vitamins in the detection of gel viscosity.

[0066] In this invention, after the condensation reaction is completed, the product is sequentially subjected to vacuum distillation, extraction, precipitation, and drying. The vacuum distillation pressure is preferably -0.09 MPa to -0.08 MPa, more preferably -0.085 MPa. The extraction reagent is preferably a mixture of purified water and ethyl acetate, and the volume ratio of purified water to ethyl acetate is preferably 1:1 to 12, more preferably 1:2 to 10, and more preferably 1:4 to 6. The precipitation process is preferably as follows: the solvent is removed from the crude organic phase mixture after extraction, and it is redissolved with ethanol (the solid content of the solution after redissolved is controlled to be 1 mg / mL to 40 mg / mL), and a large amount of purified water is added to the ethanol. After standing, a large amount of crystals precipitate out, and the crystalline precipitate is obtained by filtration. The preferred settling temperature is 1–10°C, more preferably 2–8°C, and even more preferably 3–6°C; the preferred settling time is 1–32 h, more preferably 10–22 h, and even more preferably 15–17 h; the preferred filtration pressure is -0.09 MPa to -0.08 MPa, and even more preferably -0.085 MPa; the preferred filtration paper is medium-speed or high-speed filter paper; the preferred drying method is vacuum drying; the preferred drying temperature is 30–80°C, more preferably 35–75°C, and even more preferably 40–65°C; and the preferred drying time is 1–48 h, more preferably 3–40 h, and even more preferably 5–35 h.

[0067] The reaction equation described in this invention is as follows:

[0068]

[0069] The present invention also provides the application of the conjugated molecular tool of piperidine-coupled vitamins in the detection of gel viscosity.

[0070] The mechanism of the piperidine-conjugated vitamin conjugated molecular tool provided by this invention for detecting the viscosity of cold compress gels is as follows: Figure 1 As shown.

[0071] The present invention also provides a method for using the aforementioned piperidine-coupled vitamin conjugated molecular tool in the detection of gel viscosity, comprising the following steps:

[0072] The conjugated molecular tool for piperidine-coupled vitamins provided in this invention is mixed with a solvent to obtain a mother liquor, which is then mixed with a cold compress gel. The solvent is preferably ethyl acetate, ethanol, N,N-dimethylformamide, methanol, or dimethyl sulfoxide.

[0073] In this invention, unless otherwise specified, all raw materials required for preparation are commercially available products well known to those skilled in the art.

[0074] 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.

[0075] Example 1

[0076] Dissolve 2.40g of quinone vitamins in ethyl acetate and stir evenly to obtain a 10M quinone vitamin solution;

[0077] 16.52 g of malononitrile was dissolved in ethyl acetate and stirred evenly to obtain a 50 M nitrile solution.

[0078] The nitrile solution was added dropwise to the quinone vitamin solution. The magnetic stirring speed was 700 rpm and the temperature was controlled at 25°C during the addition. The dropping speed was 30 mL / min. After the addition was completed, the magnetic stirring speed was increased to 1800 rpm and the temperature was increased to 70°C for the nitrification reaction to last for 16.0 h.

[0079] After the nitrification reaction, the product is sequentially subjected to vacuum distillation, precipitation, purification, and drying. The vacuum distillation pressure is -0.085 MPa. Precipitation is achieved by placing the vacuum distillation product in a mixed solution of ethanol and purified water at a volume ratio of 1:10. The ethanol and purified water mixture is then placed at a low temperature (5°C) for 18 hours, maintaining a mass-to-volume ratio of 15 mg:10 mL to precipitate a large amount of crystals. Purification involves removing the solvent by vacuum filtration, preferably using slow-speed filter paper with a certain number of layers. The product was processed in two layers. During filtration, it was washed twice with ethanol and purified water at the same volume ratio as in the precipitation step. Then, it was purified using a silica gel column with a mixture of dichloromethane and methanol as the solvent (volume ratio 10:1) and 300-mesh silica gel powder. The drying process involved dispersing the purified product in ethanol and purified water at a volume ratio of 1:40, controlling the solid content at 5 mg / mL, and then placing it in a freeze dryer at -10°C for 16 hours.

[0080] 9.45 g of 4-piperidin-1-ylbenzaldehyde was dissolved in methanol and stirred until homogeneous to obtain a 4-piperidin-1-ylbenzaldehyde solution with a concentration of 50 mol / L. 1.68 g of quinone vitamin nitrile was dissolved in acetonitrile and stirred until homogeneous to obtain a quinone vitamin nitrile solution with a concentration of 40 mol / L.

[0081] At 20°C and 1200 rpm, a quinone vitamin nitrile solution was added dropwise to a 4-piperidin-1-yl-benzaldehyde solution at a rate of 1 drop / 5 s. The stirring time was 14 h. After stirring, the dehydration condensation reaction was carried out at 70°C for 32 h, with the stirring rate controlled at 600 r / min.

[0082] After the condensation reaction, the product of the dehydration condensation reaction was purified by sequentially performing vacuum distillation, extraction, precipitation, and drying. Vacuum distillation was carried out in a rotary evaporator at a pressure of -0.085 MPa. After removing the reaction solvent by vacuum distillation, extraction was performed using a mixture of purified water and ethyl acetate at a volume ratio of 1:5. The organic phase was collected. The solvent was removed from the crude organic phase mixture after extraction, and it was dissolved again with ethanol (controlling the solid content to 10 mg / mL). A large amount of purified water was added to the ethanol, and the mixture was allowed to stand at 5°C for 16 h, which precipitated a large amount of crystals. The crystal precipitate was obtained by filtration using rapid filter paper at -0.085 MPa. The obtained crystals were dried in a vacuum oven at 40°C for 20 h, yielding 2.38 g of solid powder, which is the conjugated molecular tool for piperidine-coupled vitamins, with a yield of 93.9%.

[0083] The relative molecular mass of the product obtained in Example 1 was determined, and the results are as follows: Figure 2 As shown, from Figure 2 It can be seen that the conjugated molecular tool for piperidine-coupled vitamins provided by this invention has a relative molecular mass of 507.63750 [M]. + Its theoretical relative mass estimate is 507.64100, which is similar to that of the natural product-modified molecular probe 2,2'-(2-(3-methylbut-2-en-1-yl)-3-(4-(piperidin-1-yl)styryl)naphthalene-1,4-diethylenediamide)dimalononitrile (MPND, C 34 H 29 The relative molecular mass of N5 is consistent; simultaneously, the chemical structure of the obtained piperidine-conjugated vitamin conjugated molecular tool was determined by nuclear magnetic resonance, and the results are as follows. Figure 3 As shown, from Figure 3 It can be seen from this that 13 C NMR (101MHz, DMSO-d6) δ 178.36, 148.30, 138.23, 134.21, 132.56, 131.68, 130.01, 129.10, 126.03, 125.18, 123.96, 123.33, 121.86, 116.20, 115.11, 112.50, 81.52, 62.01, 55.21, 27.60, 26.32, 25.51, 25.33, 18.20. The carbon skeleton shift in its molecular structure was confirmed, and it can be identified as the target product MPND.

[0084] Example 2

[0085] Dissolve 2.40g of quinone vitamins in tetrahydrofuran and stir evenly to obtain a quinone vitamin solution with a concentration of 1M.

[0086] Dissolve 0.66 g of malononitrile in tetrahydrofuran and stir evenly to obtain a 1 M nitrile solution;

[0087] The nitrile solution was added dropwise to the quinone vitamin solution. The magnetic stirring speed was 300 rpm and the temperature was controlled at 25°C during the addition. The dropping speed was 1 mL / min. After the addition was completed, the magnetic stirring speed was increased to 2200 rpm and the temperature was increased to 30°C for the nitrification reaction to last for 32.0 h.

[0088] After the nitrification reaction, the product was sequentially subjected to vacuum distillation, precipitation, purification, and drying. The vacuum distillation pressure was -0.085 MPa. Precipitation was achieved by placing the vacuum distillation product in a mixed solution of ethanol and purified water at a volume ratio of 1:1, and then placing the ethanol and purified water mixture at a low temperature (5°C) for 1 hour, controlling the mass-to-volume ratio of the precipitation system to be 1 mg:10 mL, which resulted in the precipitation of a large number of crystals. Purification was achieved by removing the solvent through vacuum filtration, preferably using slow-speed filter paper with one layer. During filtration, the product was repeatedly washed three times with ethanol and purified water at the same volume ratio as in the precipitation step. Subsequently, the product was purified using a silica gel column with a mixed system of dichloromethane and methanol at a volume ratio of 1:1 and 100-mesh silica gel powder. Drying was achieved by dispersing the obtained purified product in ethanol and purified water at a volume ratio of 1:1, controlling the solid content to be 1 mg / mL, and then placing it in a freeze dryer at a temperature of -20°C for 1 hour.

[0089] 189.25 g of 4-piperidin-1-ylbenzaldehyde was dissolved in ethanol and stirred until homogeneous to obtain a 1 mol / L 4-piperidin-1-ylbenzaldehyde solution. 336.40 g of quinone vitamin nitrile was dissolved in ethanol and stirred until homogeneous to obtain a 1 mol / L quinone vitamin nitrile solution.

[0090] At 20°C and 100 rpm, a vitamin nitrile solution was added dropwise to a 4-piperidin-1-yl-benzaldehyde solution at a rate of 1 drop / 10 s. The stirring time was 24 h. After stirring, the dehydration condensation reaction was carried out at 25°C for 72 h, with the stirring rate controlled at 100 r / min during the dehydration condensation reaction.

[0091] After the reaction, the product of the dehydration condensation reaction was purified by sequentially performing vacuum distillation, extraction, precipitation, and drying. Vacuum distillation was carried out in a rotary evaporator at a pressure of -0.08 MPa. After removing the reaction solvent by vacuum distillation, extraction was performed using a mixture of purified water and ethyl acetate at a volume ratio of 1:1. The organic phase was collected. The solvent was removed from the crude organic phase mixture after extraction, and it was dissolved again in ethanol (controlling the solid content to 1 mg / mL). A large amount of purified water was added to the ethanol, and the mixture was allowed to stand at 1°C for 1 h, which precipitated a large amount of crystals. The crystal precipitate was obtained by filtration using rapid filter paper at -0.08 MPa. The obtained crystals were dried in a vacuum oven at 30°C for 48 h, yielding 385.81 g of solid powder, which is the conjugated molecular tool for piperidine-coupled vitamins, with a yield of 76.0%.

[0092] Example 3

[0093] 48.0g of quinone vitamins were dissolved in N,N-dimethylformamide and stirred evenly to obtain a quinone vitamin solution with a concentration of 20M.

[0094] 660.6 g of malononitrile was dissolved in N,N-dimethylformamide and stirred evenly to obtain a 100 M nitrile solution.

[0095] The nitrile solution was added dropwise to the quinone vitamin solution. The magnetic stirring speed was 1200 rpm and the temperature was controlled at 25°C during the addition. The dropping speed was 60 mL / min. After the addition was completed, the magnetic stirring speed was increased to 1200 rpm and the temperature was increased to 120°C for 0.5 h of nitrification reaction.

[0096] After the nitrification reaction, the product is sequentially subjected to vacuum distillation, precipitation, purification, and drying. The vacuum distillation pressure is -0.085 MPa. Precipitation is achieved by placing the vacuum distillation product in a mixed solution of ethanol and purified water at a volume ratio of 1:20, and incubating the mixture at 5°C for 36 hours. The mass-to-volume ratio of the precipitation system is controlled at 30 mg:10 mL, resulting in the precipitation of a large amount of crystals. Purification involves removing the solvent by vacuum filtration, preferably using slow-speed filter paper with four layers. During the filtration process, the sample was washed once repeatedly with ethanol and purified water at the same volume ratio as in the precipitation step. Then, it was purified using a silica gel column with a dichloromethane and methanol mixture as the solvent (volume ratio 30:1) and 600-mesh silica gel powder. The drying process involved dispersing the purified product in ethanol and purified water at a volume ratio of 1:80, controlling the solid content at 10 mg / mL, and then placing it in a freeze dryer at 0°C for 32 hours.

[0097] 567.8 g of 4-piperidin-1-ylbenzaldehyde was dissolved in propanol and stirred until homogeneous to obtain a 200 mol / L 4-piperidin-1-ylbenzaldehyde solution. 33.6 g of vitamin nitrile was dissolved in propanol and stirred until homogeneous to obtain a 80 mol / L vitamin nitrile solution.

[0098] At 20℃ and 2000rpm, a vitamin nitrile solution was added dropwise to a 4-piperidin-1-yl-benzaldehyde solution at a rate of 1 drop / s. The stirring time was 1h. After stirring, the dehydration condensation reaction was carried out at 90℃ for 1h. The stirring rate during the dehydration condensation reaction was controlled at 1000r / min.

[0099] After the reaction, the product of the dehydration condensation reaction was purified by sequentially performing vacuum distillation, extraction, precipitation, and drying. Vacuum distillation was carried out in a rotary evaporator at a pressure of -0.09 MPa. After removing the reaction solvent by vacuum distillation, extraction was performed using a mixture of purified water and ethyl acetate at a volume ratio of 1:12. The organic phase was collected. The solvent in the crude organic phase mixture was removed and dissolved again in ethanol (controlling the solid content to 40 mg / mL). A large amount of purified water was added to the ethanol, and the mixture was allowed to stand at 10°C for 32 h, which precipitated a large amount of crystals. The crystalline precipitate was obtained by filtration using rapid filter paper at -0.09 MPa. The obtained crystals were dried in a vacuum oven at 80°C for 1 h, yielding 41.8 g of solid powder, which is the conjugated molecular tool for piperidine-coupled vitamins, with a yield of 82.3%.

[0100] Application Example 1

[0101] 1.01 mg of the piperidine-conjugated vitamin conjugated molecular tool prepared in Example 1 was dissolved in ethanol to obtain a 2 mmol / L solution of the piperidine-conjugated vitamin conjugated molecular tool. This solution was then added to three different common medical cooling gels: Cooling Gel 1 (Fushuntang), Cooling Gel 2 (Maishu), and Cooling Gel 3 (Zuyitang) to obtain mixtures. The mass concentration of the piperidine-conjugated vitamin conjugated molecular tool was controlled at 10 μmol / L. During the test, the excitation wavelength was controlled at 520 nm at room temperature. The test results are as follows: Figure 4 As shown.

[0102] Depend on Figure 4The obtained spectral results show that there are significant differences in the light signal emission intensity of the three cooling gels. Cooling gel 1 has the strongest light emission signal, while cooling gel 3 has the weakest. This may be related to the different concentrations of the thickening components contained in the cooling gels. It also indirectly indicates that the micro-viscosity of the three cooling gels is not the same; cooling gel 1 has the highest micro-viscosity, and cooling gel 3 has the lowest micro-viscosity, thus causing the apparent difference in light signal intensity. These test results show that the piperidine-coupled vitamin conjugated molecular tool (MPND) provided by this invention can respond to micro-viscosity, thereby determining the relative viscosity of the cooling gel. That is, it achieves the conversion of light signal intensity through spatial confinement, which is of great significance for the precise control of the viscosity of cooling gels.

[0103] Performance testing

[0104] The piperidine-coupled vitamin conjugated molecular tool (MPND) prepared in Example 1 was subjected to response tests, photostability tests, polarity tests, and pH stability tests in different solutions.

[0105] Response testing:

[0106] Different proportions of purified water and glycerol were thoroughly mixed, controlling their respective volume fractions (purified water 1%–100%). The excitation wavelength of the external light source was set to 520 nm, the test concentration was 10 μM, and the test was conducted at 25°C. The test results are as follows: Figure 5 As shown.

[0107] After preparation using the volume fractions described in Table 1, the relative viscosity can be well controlled, ranging from 1.0 cP to 956.0 cP. Figure 5 The spectral results show that the fluorescence intensity gradually increases as the viscosity of the mixed solution increases. In particular, when the volume fraction of glycerol exceeds 70%, the light signal intensity increases sharply, with the light signal release intensity increasing by up to 190 times compared to the purified water system.

[0108] In addition, an attempt was made to convert the light signal intensity and viscosity value into a logarithmic function and fit it, specifically as follows: Figure 6 As shown, from Figure 6 It can be seen that the logarithmic function of the light signal intensity emitted by the piperidine-coupled vitamin conjugated molecular tool (MPND) provided by this invention and the logarithmic function of different viscosity values ​​can be fitted to a straight line, which is consistent with... The relationship (log I = C + x logη) is consistent, and the viscosity sensitivity coefficient of MPND reaches 0.80, with a fitting coefficient of determination of 0.99, indicating that it has a high sensitivity to viscosity and is suitable as a molecular tool for sensing viscosity in micro-regions.

[0109] Table 1. Logarithm of viscosity and logarithm of light signal emission intensity

[0110] Logarithm of viscosity (logη) 0.01 0.24 0.57 1.03 1.77 2.99 Logarithm of fluorescence intensity (logI) 1.25 1.35 1.56 1.90 2.69 3.53

[0111] Light stability test:

[0112] 2.54 mg of the piperidine-coupled vitamin conjugated molecular tool (MPND) prepared in Example 1 was dissolved in ethanol to a concentration of 5 mM. For specific testing, it was further diluted to 10 μM and added to two typical solvents of different viscosities (purified water and glycerol). The solutions were then continuously irradiated under a 520 nm excitation source for 60 min. The test results are as follows: Figure 7 As shown, the obtained data is collected in Table 2.

[0113] Table 2 Fluorescence test results

[0114] Time / min 0 10 20 30 60 Fluorescence intensity in purified water / au 18.1 17.8 17.4 17.0 16.3 Fluorescence intensity in glycerol / au 3430.2 3428.1 3425.6 3420.3 3410.6

[0115] Depend on Figure 7 As shown in Table 2, the obtained piperidine-coupled vitamin conjugated molecular tool (MPND) can still release a stable light signal under continuous irradiation for a long time, and has good photostability in both high-viscosity and low-viscosity solution atmospheres.

[0116] Solvent resistance polarity test:

[0117] 2.03 mg of the piperidine-coupled vitamin conjugated molecular tool (MPND) from Example 1 was dissolved in ethanol to control its concentration at 4 mM. For testing, it was further diluted to 10 μM and added to various common solutions of different polarities to verify its solvent resistance. The six solutions of different polarities were glycerol, dimethyl sulfoxide, tetrahydrofuran, dichloromethane, toluene, and ethanol. The results are as follows: Figure 8 As shown.

[0118] from Figure 8 It can be seen that the absorbance and absorption wavelength of this molecular tool (MPND) are similar in a variety of common solvents, and it will not be adversely affected by the different polarities of the solvents. This indicates that the conjugated molecular tool (MPND) of piperidine-coupled vitamins will not change its absorption spectrum due to the change of solution polarity even in solution atmospheres with different polarities, and has good solvent polarity resistance and stability.

[0119] pH stability test:

[0120] 5.08 mg of the piperidine-conjugated vitamin conjugated molecular tool (MPND) prepared in Example 1 was dissolved in ethanol to control its concentration at 10 mM. For testing, it was further diluted to 10 μM. Since cold compress gels typically contain many components, which may cause various pH differences, the selected pH range was 3–12 to verify the pH stability of the molecular tool (MPND). The test results are as follows: Figure 9 As shown.

[0121] Depend on Figure 9 The test results show that the light signal release intensity of the piperidine-coupled vitamin conjugated molecular tool (MPND) does not change significantly under various pH atmospheres, indicating stable light signal release and good universality and application potential.

[0122] As demonstrated by the above embodiments, this invention provides a piperidine-conjugated vitamin conjugated molecular tool with a favorable conjugated structure. Further modification extends the conjugation, effectively expanding the redshift of the emission spectrum and making the molecular structure more flexible. It can exhibit different rotational states under different spatial confinement conditions, which are then converted into optical signals, enabling effective detection of micro-region viscosity at the molecular level. Various test results show that the piperidine-conjugated vitamin conjugated molecular tool possesses good photostability, pH stability, solvent resistance, and good anti-interference properties, with a peak emission wavelength reaching 707 nm. It effectively avoids signal interference that may be caused by various additives contained in the cooling gel. Furthermore, the piperidine-coupled vitamin conjugated molecular tool provided by this invention is prepared by a two-step method, which involves further coupling with an aromatic piperidine derivative based on the nitrification reaction of a natural quinone derivative. The raw materials are abundant, the preparation process is environmentally friendly, the yield of the product is high, the raw materials used are inexpensive, the cost is low, and the post-processing is simple and easy to perform, without the need for large amounts of reagent purification. A large number of product crystals can be obtained through simple conjugation and low-temperature crystallization, making it suitable for large-scale industrial applications.

[0123] 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 conjugated molecular tool for piperidine-coupled vitamins, characterized in that, The conjugated molecular tool for the piperidine-coupled vitamin is: 。 2. The method for preparing the piperidine-coupled vitamin conjugated molecular tool according to claim 1, characterized in that, Includes the following steps: (1) A quinone vitamin solution is mixed with a nitrile solution to carry out a nitrification reaction to obtain quinone vitamin nitrile; (2) The conjugated molecular tool of the piperidine-coupled vitamin is obtained by mixing 4-piperidin-1-ylbenzaldehyde solution with quinone vitamin nitrile solution and carrying out a condensation reaction. The chemical structural formula of the quinone vitamins in the quinone vitamin solution is as follows: ； The nitrile in the nitrile solution is malononitrile; The structural formula of the quinone vitamin nitrile is: 。 3. The method for preparing the conjugated molecular tool of piperidine-coupled vitamins as described in claim 2, characterized in that, The concentration of the quinone vitamin solution in step (1) is 1~20M, and the solvent of the quinone vitamin solution is one or more of methanol, tetrahydrofuran, ethanol, N,N-dimethylformamide, ethyl acetate and dimethyl sulfoxide.

4. The method for preparing the conjugated molecular tool of piperidine-coupled vitamins as described in claim 2 or 3, characterized in that, The concentration of the nitrile solution in step (1) is 1-100M, and the solvent of the nitrile solution is one or more of methanol, tetrahydrofuran, ethanol, N,N-dimethylformamide, ethyl acetate and dimethyl sulfoxide. The molar ratio of quinone vitamins to nitrile compounds is 1:1 to 50.

5. The method for preparing the conjugated molecular tool of piperidine-coupled vitamins as described in claim 4, characterized in that, The temperature of the nitrification reaction in step (1) is 30 to 120°C, and the time of the nitrification reaction is 0.5 to 32.0 h.

6. The method for preparing the conjugated molecular tool of piperidine-coupled vitamins as described in claim 5, characterized in that, The concentration of the 4-piperidine-1-yl-benzaldehyde solution in step (2) is 1 to 200 mol / L, and the solvent of the 4-piperidine-1-yl-benzaldehyde solution is one or more of methanol, ethanol, n-butanol, propanol, isopropanol, n-pentanol, ethylene glycol, diethylene glycol, 1,2-propanediol, 1,3-propanediol and 1,3-butanediol.

7. The method for preparing the piperidine-coupled vitamin conjugated molecular tool as described in claim 6, characterized in that, The concentration of the quinone vitamin nitrile solution in step (2) is 1-80 mol / L, and the solvent of the quinone vitamin nitrile solution is one or more of methanol, ethanol, n-butanol, propanol, isopropanol, n-pentanol, ethylene glycol, diethylene glycol, 1,2-propanediol, 1,3-propanediol and 1,3-butanediol.

8. The method for preparing the conjugated molecular tool of piperidine-coupled vitamins as described in claim 7, characterized in that, The molar ratio of 4-piperidin-1-ylbenzaldehyde to quinone vitamins is 1 to 30:

1.

9. The method for preparing the conjugated molecular tool of piperidine-coupled vitamins as described in claim 7 or 8, characterized in that, The temperature of the condensation reaction in step (2) is 20 to 90°C, and the time of the condensation reaction is 1 to 78 hours.

10. The application of the piperidine-coupled vitamin conjugated molecular tool of claim 1 in the detection of gel viscosity.

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