Asarone-based conjugated chromogenic molecules, and preparation method and application thereof

Abstract

The application belongs to the technical field of cosmetic analysis and detection, and discloses a conjugated color-producing molecule based on asarin and a preparation method and application thereof. The preparation method of the conjugated color-producing molecule based on asarin comprises the following steps: mixing a quinone derivative solution, a dehydrating agent dispersion liquid and an asarin solution, performing a dehydration condensation reaction, and obtaining the conjugated color-producing molecule based on asarin; wherein the quinone derivative in the quinone derivative solution is lanshanqinone. The conjugated color-producing molecule based on asarin can respond to the change of the viscosity of a gel microzone, is helpful to judge the subtle change of the viscosity, has high sensitivity to the viscosity, has a relatively stable chemical structure, can exist in a complex gel for a long time, and has a very strong visual effect.

Description

Technical Field

[0001] This invention relates to the field of cosmetic analysis and detection technology, and in particular to an asaraldehyde-based conjugated chromogenic molecule, its preparation method, and its application. Background Technology

[0002] Hair gel is a type of hairspray, often used as a spray for styling hair. It boasts unparalleled advantages in quick styling, high-efficiency shine, and voluminous hair. As a gel, it is commonly found as a transparent, fluid liquid, with main components including film-forming agents, conditioning agents, diluents, and other additives. Its viscosity can be controlled, particularly by adjusting the diluent in the main ingredient. Different users have varying requirements for the styling power of hair gels, which is reflected in the relative viscosity of hair gel. High-viscosity hair gel allows for quick styling, but it tends to clump hair together, attracts dust more easily, and can damage hair. Low-viscosity hair gel has better fluidity, allowing it to adhere naturally to the hair when sprayed with an air pump. While its styling power is slightly lower, it provides a more voluminous and natural look, better moisturizing effects, less attraction to dust, and less damage to the hair. Therefore, in order to effectively and specifically improve the formulation design of hair gels and to accurately customize hair gels with different viscosities according to customer needs, it is essential to develop a method that can rapidly, in-situ, and visualize viscosity measurement. Traditional methods for analyzing the viscosity of hair gels mostly rely on various viscometers, which require large sample volumes and long measurement times. More importantly, it is difficult to accurately measure the micro-region viscosity of hair gels containing a large amount of pseudoplastic fluids, because pseudoplastic fluids exhibit shear thinning during shear measurement. Furthermore, it is difficult to achieve molecular-level viscosity measurement.

[0003] In the field of cosmetic analysis and testing, photochemical technology can measure the micro-viscosity of hair gels using molecular tools, ultimately manifesting as a visible light signal. This static response method effectively avoids errors caused by traditional shear-thinning techniques and significantly improves the control of hair gel viscosity. Therefore, there is an urgent need to develop a molecular-level tool suitable for testing the viscosity of hair gels. Summary of the Invention

[0004] The purpose of this invention is to provide an asaraldehyde-based conjugated chromophore, its preparation method, and its application, thereby solving the problem of the difficulty in accurately measuring the viscosity of gel micro-regions in the prior art.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides an asaraldehyde-based conjugated chromophore having the structure shown in Formula 1: Formula 1.

[0006] This invention also provides a method for preparing an asaraldehyde-based conjugated chromophore, comprising the following steps: A quinone derivative solution, a dehydrating agent dispersion, and an asaraldehyde solution were mixed and subjected to a dehydration condensation reaction to obtain an asaraldehyde-based conjugated chromophore (HTTND).

[0007] The quinone derivative in the quinone derivative solution is Plumbagin.

[0008] Preferably, in the above-mentioned method for preparing an asaraldehyde-based conjugated chromophore, the solvent of the quinone derivative solution is one or more of methanol, tetrahydrofuran, ethanol, N,N-dimethylformamide, ethyl acetate, and dimethyl sulfoxide. The concentration of the quinone derivative solution is 1~25M.

[0009] Preferably, in the above-mentioned method for preparing an asaraldehyde-based conjugated chromophore, the solvent of the dehydrating agent dispersion is one or more of methanol, tetrahydrofuran, ethanol, N,N-dimethylformamide, ethyl acetate, and dimethyl sulfoxide. The dehydrating agent in the dehydrating agent dispersion is one or more of sodium carbonate, cesium carbonate, aluminum hydroxide, sodium bicarbonate, potassium carbonate, potassium bicarbonate, magnesium hydroxide, calcium carbonate, and calcium acetate. The concentration of the dehydrating agent dispersion is 1~600M.

[0010] Preferably, in the above-mentioned method for preparing an asaraldehyde-based conjugated chromophore, the solvent of the asaraldehyde solution is an alcohol solvent; The concentration of the asaraldehyde solution is 1~200M.

[0011] Preferably, in the above-mentioned method for preparing an asaraldehyde-based conjugated chromophore, the molar ratio of asaraldehyde in the asaraldehyde solution to the quinone derivative in the quinone derivative solution is 1~50:1; The molar ratio of the dehydrating agent in the dehydrating agent dispersion to the quinone derivative in the quinone derivative solution is 1~350:1.

[0012] Preferably, in the above-mentioned method for preparing an asaraldehyde-based conjugated chromophore, the temperature of the dehydration condensation reaction is 60~100℃, and the time of the dehydration condensation reaction is 1~30h.

[0013] The present invention also provides an application of asaraldehyde-based conjugated chromophores in the measurement of viscosity in gel microregions.

[0014] The asaraldehyde-based conjugated chromophore of this invention is obtained by conjugating a natural acorus calamus extract—asaraldehyde—with a quinone derivative, lanshoquinone, to form a chromophore structure. This preparation process is achieved through a simple one-step dehydration condensation method, ultimately exhibiting a conjugated chromophore chemical structure with alternating single and double bonds. The resulting chromophore structure exhibits certain rotatable properties, allowing free rotation in low-viscosity gels. The dissipation of excited-state energy is mainly through mechanical rotation, resulting in a weak or even unobservable surface signal. In contrast, rotation is restricted in high-viscosity gels, and the excited-state energy is mainly dissipated through radiative transitions, resulting in a stronger surface signal that is observable to the naked eye. This enables effective measurement of the viscosity of micro-regions in gels. As an example of a molecular tool, the asaraldehyde-based conjugated chromophore, when added to a gel, allows for the determination of the gel's viscosity based on the intensity of the emitted light signal. A stronger light signal indicates a thicker gel, greater hindrance during flow, and relatively stronger covering power, adhesion, and coatability. Conversely, a weaker light signal indicates stronger flowability, spreadability, and brushability. For details on the mechanism of using the asaraldehyde-based conjugated chromophore for gel viscosity measurement, please refer to [link to relevant documentation]. Figure 1 .

[0015] The asaraldehyde-based conjugated chromophore provided by this invention can act as a signal switch to effectively measure the relative viscosity of micro-regions, which helps improve the gel formulation process and refine its consistency control, thus meeting customers' needs for gels of different consistencyes in a customized and efficient manner. The asaraldehyde-based conjugated chromophore based on Acorus tatarinowii extract of this invention can release a strong light signal in the wavelength range of 470~800nm ​​under external excitation at 450nm, with a peak wavelength around 560nm. This allows for effective measurement of the micro-region viscosity of gels, providing better data support and solutions for the problems of consistency adjustment and the difficulty in measuring microscopic viscosity changes.

[0016] As can be seen from the above technical solution, compared with the prior art, the present invention has the following beneficial effects: (1) The asaraldehyde conjugated chromophore provided by the present invention is to couple the natural acorus calamus extract—asaraldehyde—with lanshoquinone to achieve the effective construction of multiple chromophores. The required raw materials are abundant and belong to natural plant extracts, which enables traditional plant extracts to be used in the development of high-value-added molecular tools across disciplines. The overall application preparation cost is low, which is suitable for large-scale preparation. The amount used is very small (milligram level), and the application cost is very low. Moreover, this method of targeted modification of plant extracts is very consistent with the concept of low-carbon and sustainable development. At the same time, the preparation process adopts a one-step method, and the final yield is also high.

[0017] (2) The asaraldehyde conjugated chromophore (HTTND) provided by this invention can respond to changes in the viscosity of micro-regions of gel, which helps to judge subtle changes in viscosity. It has high sensitivity to viscosity, with a very high viscosity sensitivity coefficient (x=0.94). It forms a large conjugated aromatic structure through quinone ring and benzyl ether, which makes the chemical structure relatively stable (no weak bonds exist). It can exist in complex gels for a long time. Its chromophore wavelength peak is 560nm, which is a typical yellow-orange light with bright color and strong visualization effect. In addition, this molecular tool can release a relatively stable light signal in a relatively wide pH range and maintain good photostability during long-term irradiation. At the same time, this molecular tool is not sensitive to the polarity of the solvent and its sensitivity to viscosity is much greater than the influence of other factors.

[0018] (3) The asaraldehyde conjugated chromophore (HTTND) provided by the present invention can be used as a molecular tool to measure the viscosity of the solution environment in situ. The measurement process does not depend on shear and relative motion. The whole process is presented by the release of light signals. Therefore, it can effectively measure the viscosity change of gel containing a large amount of pseudoplastic fluid. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0020] Figure 1 This is a schematic diagram illustrating the mechanism of the asaraldehyde-based conjugated chromophore in detecting the viscosity of gel micro-regions in this invention. Figure 2 This is the high-resolution mass spectrum of the asaraldehyde conjugated chromophore in Example 1; Figure 3 The nuclear magnetic resonance spectrum of the asaraldehyde conjugated chromophore in Example 1; Figure 4 The spectra of the asaraldehyde conjugated chromophore in Example 1 in solutions of different viscosities are shown. Figure 5 This is a linear fit graph between the light signal intensity and solution viscosity of the asaraldehyde conjugated chromophore molecule in Example 1; Figure 6 The spectra of the asaraldehyde conjugated chromophore molecule in Example 1 in solutions with different pH values ​​are shown. Figure 7 The results of photostability tests of the asaraldehyde conjugated chromophore in glycerol and purified water in Example 1 are shown. Figure 8 The absorption spectra of the asaraldehyde conjugated chromophore molecule in Example 1 in different solvents are shown. Figure 9The image shows the emission spectrum of the asaraldehyde conjugated chromophore in the gel water in Example 1. Detailed Implementation

[0021] This invention provides an asaraldehyde-based conjugated chromophore having the structure shown in Formula 1: Formula 1.

[0022] In this invention, the asaraldehyde-based conjugated chromophore is named 5-hydroxy-2-(2,4,5-trimethoxystyryl)naphthalene-1,4-dione, abbreviated as HTTND, with the molecular formula C. 21 H 18 O6 has a theoretical relative molecular mass of 366.36.

[0023] This invention also provides a method for preparing an asaraldehyde-based conjugated chromophore, comprising the following steps: A quinone derivative solution, a dehydrating agent dispersion, and an asaraldehyde solution were mixed and subjected to a dehydration condensation reaction to obtain an asaraldehyde-based conjugated chromophore, abbreviated as HTTND.

[0024] The quinone derivative in the quinone derivative solution is lanshoquinone.

[0025] In this invention, the reaction equations involved in the preparation process of the asaraldehyde-based conjugated chromophore molecule are as follows: .

[0026] In this invention, the solvent of the quinone derivative solution is preferably one or more of methanol, tetrahydrofuran, ethanol, N,N-dimethylformamide, ethyl acetate and dimethyl sulfoxide, more preferably one or more of methanol, tetrahydrofuran, ethanol and N,N-dimethylformamide, and even more preferably one or more of methanol, tetrahydrofuran and ethanol.

[0027] In this invention, the concentration of the quinone derivative solution is preferably 1-25 M, more preferably 5-20 M, and even more preferably 7-15 M.

[0028] In this invention, the solvent of the dehydrating agent dispersion is preferably one or more of methanol, tetrahydrofuran, ethanol, N,N-dimethylformamide, ethyl acetate and dimethyl sulfoxide, more preferably one or more of methanol, tetrahydrofuran, ethanol and N,N-dimethylformamide, and even more preferably one or more of methanol, tetrahydrofuran and ethanol.

[0029] In this invention, the dehydrating agent in the dehydrating agent dispersion is preferably one or more of sodium carbonate, cesium carbonate, aluminum hydroxide, sodium bicarbonate, potassium carbonate, potassium bicarbonate, magnesium hydroxide, calcium carbonate, calcium acetate, and tin acetate, more preferably one or more of sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, and magnesium hydroxide, and even more preferably one or more of sodium carbonate, sodium bicarbonate, and potassium carbonate.

[0030] In this invention, the concentration of the dehydrating agent dispersion is preferably 1~600M, more preferably 50~500M, and even more preferably 130~420M.

[0031] In this invention, the solvent for the asaraldehyde solution is preferably an alcohol solvent; The alcohol solvent is preferably one or more of methanol, ethanol, propanol, n-butanol, ethylene glycol, 1,2-propanediol, 1,3-propanediol and 1,3-butanediol, more preferably one or more of methanol, ethanol, propanol, n-butanol, 1,2-propanediol and 1,3-propanediol, and even more preferably one or more of methanol, ethanol, propanol and n-butanol.

[0032] In this invention, the concentration of the asaraldehyde solution is preferably 1~200M, more preferably 8~175M, and even more preferably 58~120M.

[0033] In this invention, the molar ratio of asaraldehyde in the asaraldehyde solution to quinone derivatives in the quinone derivative solution is preferably 1~50:1, more preferably 5~30:1, and even more preferably 8~20:1.

[0034] In this invention, the molar ratio of the dehydrating agent in the dehydrating agent dispersion to the quinone derivative in the quinone derivative solution is preferably 1~350:1, more preferably 12~220:1, and even more preferably 50~200:1.

[0035] In this invention, the specific process of mixing the quinone derivative solution, the dehydrating agent dispersion, and the asaraldehyde solution is as follows: First, mix the quinone derivative solution and the dehydrating agent dispersion at room temperature and stir at a rate of 100-1200 rpm for 1-18 hours. Then, while keeping the stirring rate constant, add the ascorbaldehyde solution dropwise at a rate of 1 drop / 10s-2 drops / s and continue stirring for 1-8 hours. Then, while stirring at a rate of 800-2000 rpm and heating at a rate of 5℃ / h-1℃ / min, heat to the dehydration condensation reaction temperature.

[0036] In this invention, the temperature of the dehydration condensation reaction is preferably 60~100℃, more preferably 65~90℃, and even more preferably 70~82℃; the time of the dehydration condensation reaction is preferably 1~30h, more preferably 5~26h, and even more preferably 12~22h.

[0037] In this invention, after the dehydration condensation reaction is completed, the process further includes: extracting, crystallizing, centrifuging and drying the obtained product; The specific extraction process is as follows: the obtained product is subjected to solvent removal at -0.09 MPa, and then extracted with a mixed solution of ethyl acetate and water. The organic phase is collected and then the solvent is removed by depressurization to -0.09 MPa. The volume ratio of ethyl acetate to water is preferably 1~10:1, more preferably 2~8:1, and even more preferably 4~6:1; The specific crystallization process is as follows: the extracted product is mixed with a mixed solution of water and ethanol, and after standing, crystalline powder is precipitated. The volume ratio of water to ethanol is preferably 1:1 to 10, more preferably 1:2 to 8, and even more preferably 1:4 to 6. The solid content of the mixed solution is preferably 1~30 mg / mL, more preferably 5~25 mg / mL, and even more preferably 12~20 mg / mL; The preferred temperature for the settling period is 1~10℃, more preferably 2~8℃, and even more preferably 5~6℃; The settling time is preferably 1 to 32 hours, more preferably 5 to 25 hours, and even more preferably 10 to 20 hours; The specific process of centrifugation is as follows: the crystalline powder obtained by crystallization is mixed with a mixed solution of water and ethanol, and then centrifuged. The volume ratio of water to ethanol is preferably 1 to 10:1, more preferably 2 to 8:1, and even more preferably 4 to 6:1; The solid content of the mixed solution is preferably 1~50 mg / mL, more preferably 5~40 mg / mL, and even more preferably 20~38 mg / mL; The centrifugation speed is preferably 1000~10000 r / min, more preferably 2000~8000 r / min, and even more preferably 3500~6000 r / min; the centrifugation time is preferably 1~18 h, more preferably 3~15 h, and even more preferably 5~12 h; the number of centrifugations is preferably 1~5 times. The specific method for drying is as follows: the product after centrifugation is placed in a vacuum oven for drying; The drying temperature is preferably 30~80℃, more preferably 40~75℃, and even more preferably 55~60℃; the drying time is preferably 1~36h, more preferably 5~32h, and even more preferably 12~24h.

[0038] The present invention also provides an application of asaraldehyde-based conjugated chromophores in the measurement of viscosity in gel microregions.

[0039] In this invention, the specific method of the application is as follows: mixing asaraldehyde conjugated chromophore molecules, solvent and gel to obtain a test solution, detecting the intensity of the light signal emitted by the test solution, and determining the viscosity of the gel based on the correspondence between the intensity of the light signal emitted by the test solution and the viscosity. The solvent is preferably an alcohol solvent, more preferably ethanol; The preferred ratio of the asaraldehyde conjugated chromophore to the gel is 5~160µmol:1L, more preferably 23~145µmol:1L, and even more preferably 50~100µmol:1L.

[0040] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] Example 1

[0042] 1 mol of asaraldehyde was dissolved in methanol and stirred evenly at room temperature to obtain a 100 M asaraldehyde solution. 0.04 mol of lansinoquinone was dissolved in methanol and stirred evenly at room temperature to obtain a 10 M lansinoquinone solution. 3 mol of sodium carbonate dehydrating agent was dispersed in methanol and stirred evenly at room temperature to obtain a sodium carbonate dehydrating agent dispersion with a concentration of 300 M. The lansinoquinone solution and sodium carbonate dehydrating agent dispersion were mixed at room temperature and mechanically stirred at 800 rpm for 9 h. Then, ascorbaldehyde solution was added dropwise at a rate of 1 drop / 3 s, and stirring was continued at 800 rpm for 4 h. Then, the mixture was stirred at 1500 rpm and heated to 68 °C at a rate of 15 °C / h for 16 h to carry out a dehydration condensation reaction to obtain the crude product. The crude product was solvent-removed at -0.09 MPa and then extracted with a mixture of ethyl acetate and purified water at a volume ratio of 4:1. The organic phase was collected and the solvent was removed by reducing the pressure to -0.09 MPa. The collected organic phase was dispersed in a mixture of purified water and ethanol at a volume ratio of 1:5 to obtain a mixed solution with a solid content of 10 mg / mL. The solution was then allowed to stand at 5 °C for 12 h to precipitate crystalline powder. The crystalline powder was dispersed in a mixture of purified water and ethanol at a volume ratio of 4:1, and the solid content of the mixed solution was 30 mg / mL. The solution was centrifuged at 4000 r / min for 12 h, and the centrifugation was repeated twice. The product obtained by centrifugation was dried in a vacuum oven at 50 °C for 20 h to obtain the asaraldehyde conjugated chromophore, denoted as HTTND, with a yield of 13.26 g and a yield of 90.5%.

[0043] Mass spectrometry analysis was performed on the relative molecular mass of the asaraldehyde-based conjugated chromophore HTTND obtained above, and its high-resolution mass spectrum is shown below. Figure 2 As shown. By Figure 2 It is known that the relative molecular mass of the asaraldehyde-conjugated chromophore HTTND is 366.36907 [M]. + The molecular formula of formula 1 is C 21 H 18 O6, with a theoretical relative mass estimate of 366.36890, shows that the asaraldehyde-based conjugated chromophore HTTND prepared in Example 1 is consistent with the target product in terms of relative molecular mass.

[0044] Meanwhile, the chemical structure of the asaraldehyde-based conjugated chromophore HTTND obtained above was confirmed by nuclear magnetic resonance (NMR), and its NMR spectrum is shown below. Figure 3 As shown. From Figure 3 It can be seen from this that 13 C NMR (101 MHz, DMSO-d6) δ 188.43, 178.82, 161.91, 155.01, 150.02, 140.10, 137.00, 136.01, 134.45, 133.91, 132.25, 124.28, 123.50, 119.50, 118.23, 114.70, 114.01, 99.12, 57.10, 56.51. The carbon skeleton shift in its molecular structure was confirmed, and it can be identified as the target product, asaraldehyde conjugated chromophore (HTTND).

[0045] Example 2

[0046] 0.01 mol of asaraldehyde was dissolved in propanol and stirred evenly at room temperature to obtain a 1 M asaraldehyde solution. 0.01 mol of lansinoquinone was dissolved in ethyl acetate and stirred until homogeneous at room temperature to obtain a 1 M lansinoquinone solution. 0.01 mol of sodium bicarbonate dehydrating agent was dispersed in ethyl acetate and stirred evenly at room temperature to obtain a 1 M sodium bicarbonate dehydrating agent dispersion. The lansinoquinone solution and sodium bicarbonate dehydrating agent dispersion were mixed at room temperature and mechanically stirred at 100 rpm for 1 h. Then, ascorbaldehyde solution was added dropwise at a rate of 1 drop / 10 s, and stirring was continued at 100 rpm for 1 h. Then, the mixture was stirred at 800 rpm and heated to 60 °C at a rate of 5 °C / h to carry out a dehydration condensation reaction for 30 h to obtain the crude product. The crude product was solvent-removed at -0.09 MPa and then extracted with a 1:1 mixture of ethyl acetate and purified water. The organic phase was collected and the solvent was removed by reducing the pressure to -0.09 MPa. The collected organic phase was dispersed in a 1:1 mixture of purified water and ethanol to obtain a mixed solution with a solid content of 1 mg / mL. The solution was then allowed to stand at 10 °C for 32 h to precipitate crystalline powder. The crystalline powder was dispersed in a 1:1 mixture of purified water and ethanol, and the solid content of the resulting solution was 1 mg / mL. The solution was centrifuged at 1000 r / min for 18 h, and centrifuged once. The product obtained by centrifugation was dried in a vacuum oven at 30 °C for 36 h to obtain the asaraldehyde conjugated chromophore, denoted as HTTND, with a yield of 3.06 g and a yield of 83.6%.

[0047] The high-resolution mass spectrometry and nuclear magnetic resonance results of the asaraldehyde-based conjugated chromophore HTTND obtained above are consistent with the results obtained in Example 1.

[0048] Example 3

[0049] Dissolve 2 mol of asaraldehyde in ethanol and stir well at room temperature to obtain a 200 M asaraldehyde solution. 0.04 mol of lansinoquinone was dissolved in tetrahydrofuran and stirred evenly at room temperature to obtain a 25 M lansinoquinone solution. 14 mol of magnesium hydroxide dehydrating agent was dispersed in N,N-dimethylformamide and stirred evenly at room temperature to obtain a magnesium hydroxide dehydrating agent dispersion with a concentration of 600 M. The lansinoquinone solution and magnesium hydroxide dehydrating agent dispersion were mixed at room temperature and mechanically stirred at 1200 rpm for 18 h. Then, ascorbaldehyde solution was added dropwise at a rate of 2 drops / s, and stirring was continued at 1200 rpm during the dropwise addition. The stirring was continued for 8 h. Then, the temperature was increased to 100 °C while stirring at a stirring rate of 2000 rpm and 1 °C / min to carry out the first dehydration condensation reaction for 30 h to obtain the crude product. The crude product was solvent-removed at -0.09 MPa and then extracted with a mixture of ethyl acetate and purified water at a volume ratio of 10:1. The organic phase was collected and the solvent was removed by reducing the pressure to -0.09 MPa. The collected organic phase was dispersed in a mixture of purified water and ethanol at a volume ratio of 1:10 to obtain a mixed solution with a solid content of 30 mg / mL. The solution was then allowed to stand at 1 °C for 1 h to precipitate crystalline powder. The crystalline powder was dispersed in a mixture of purified water and ethanol at a volume ratio of 10:1, and the solid content of the mixed solution was 50 mg / mL. The solution was centrifuged at 10000 r / min for 36 h, 5 times. The product obtained by centrifugation was dried in a vacuum oven at 80 °C for 1 h to obtain the asaraldehyde conjugated chromophore, denoted as HTTND, with a yield of 12.50 g and a yield of 85.2%.

[0050] The high-resolution mass spectrometry and nuclear magnetic resonance results of the asaraldehyde-based conjugated chromophore HTTND obtained above are consistent with the results obtained in Example 1.

[0051] Performance testing

[0052] The asaraldehyde-based conjugated chromophore HTTND prepared in Example 1 was subjected to various spectroscopic tests, including viscosity sensitivity test, photostability test, pH stability test, and detection limit test.

[0053] 1. Viscosity sensitivity test of the asaraldehyde-based conjugated chromophore HTTND prepared in Example 1: Solutions of varying viscosities (1.00 cP to 956.00 cP) were obtained by adjusting the proportions of glycerol and purified water (the relationship between solution viscosity and glycerol content is shown in Table 1). Asaraldehyde-based conjugated chromophore HTTND was added to each solution to achieve a concentration of 10 µM. The external excitation wavelength was controlled at 440 nm, and tests were conducted at room temperature. The resulting spectra are shown below. Figure 4 As shown.

[0054] Table 1. Relationship between solution viscosity and glycerol content in the solution.

[0055] like Figure 4It can be seen that as the solution viscosity increases from 1.0 cP to 956.0 cP, the intensity of the observed light signal gradually increases. In particular, when the amount of glycerol added exceeds 50%, the intensity of the released light signal increases sharply until the volume fraction of purified water is 0%, at which point the light signal intensity reaches its maximum value, which is up to 479 times higher than the solution system without added glycerol.

[0056] Furthermore, the relationship between optical signal intensity and solution viscosity was established, with the solution viscosity ranging from 1.00 to 956.00 cP. After converting the optical signal intensity and solution viscosity into logarithmic functions, a straight line was fitted, conforming to the Förster-Hoffmann relation, as detailed below. Figure 5 As shown in Table 2, the specific logarithmic function values ​​are as follows.

[0057] Table 2. Logarithm of solution viscosity versus logarithm of fluorescence intensity

[0058] Depend on Figure 5 As shown in Table 2, HTTND exhibits a viscosity sensitivity coefficient of 0.94 and a coefficient of determination of 0.98, demonstrating high viscosity sensitivity. The results indicate that the asaraldehyde-based conjugated chromophore HTTND provided by this invention can be used as a molecular tool for measuring the micro-region viscosity of gel water. The strength of the apparent visual signal can be used to determine its viscosity, providing a rapid, efficient, and visually intuitive method for its preparation.

[0059] 2. pH stability test of the asaraldehyde-based conjugated chromophore HTTND prepared in Example 1: 1.10 mg of the asaraldehyde-based conjugated chromophore HTTND prepared in Example 1 was dissolved in ethanol to a concentration of 3 mM. This solution was then added to a buffer solution (disodium hydrogen phosphate / potassium dihydrogen phosphate) with a pH range of 5–12 to achieve a HTTND concentration of 10 µM. The changes in light signal intensity were measured at room temperature. The test results are as follows: Figure 6 As shown.

[0060] like Figure 6 It can be seen that the fluorescence intensity of the asaraldehyde conjugated chromophore HTTND does not change much in the pH range of 5 to 12, and it can show good light signal release stability. It is not easily affected by pH fluctuations, and has high pH tolerance and universality.

[0061] 3. Photostability test of the asaraldehyde-based conjugated chromophore HTTND prepared in Example 1: 2.20 mg of the asaraldehyde-based conjugated chromophore HTTND prepared in Example 1 was dissolved in ethanol to a concentration of 6 mM. Then, it was added to low-viscosity purified water (1.0 cP) and high-viscosity 99% (v / v) glycerol solution (956.0 cP) to achieve a HTTND concentration of 10 µM. Under continuous irradiation with an external excitation light source at 440 nm, the change in its light signal intensity over 60 min was measured. The test results are as follows: Figure 7 As shown in Table 3, the obtained data are presented in the table below.

[0062] Table 3 Fluorescence test results

[0063] Depend on Figure 7 As shown in Table 3, the photostability of the asaraldehyde-based conjugated chromophore HTTND remains stable under continuous external light source irradiation, whether in high-viscosity glycerol or low-viscosity purified water. This photostability indicates that it is suitable for micro-area viscosity response in gel water and will not be significantly affected even under long-term irradiation.

[0064] 4. Polarity tolerance test of the asaraldehyde-based conjugated chromophore HTTND prepared in Example 1: 2.93 mg of the asaraldehyde-based conjugated chromophore HTTND prepared in Example 1 was dissolved in ethanol to a concentration of 8 mM. This solution was then added to various conventional solvents of different polarities to achieve a concentration of 10 μM for HTTND. The light signal absorption characteristics under different polarity solvent atmospheres were tested. The tests were conducted at room temperature, and the results are as follows: Figure 8 As shown.

[0065] Depend on Figure 8 The results show that in various solvents (including ethanol, toluene, dichloromethane, tetrahydrofuran, dimethyl sulfoxide, and glycerol), the absorbance of the asaraldehyde-based conjugated chromophore HTTND is around 0.6, and its absorption spectrum peak is around 440 nm. However, when added to glycerol, its absorbance decreases slightly, and its absorption spectrum peak redshifts to around 465 nm. This may be because the high viscosity of the solution atmosphere causes a certain degree of spatial conjugation in the molecular switch HTTND, resulting in a redshift effect. Overall, the results indicate that the molecular tool HTTND is not sensitive to the polarity of the solution and is suitable for regulating and monitoring the viscosity changes of gel water containing multiple polar components.

[0066] Application Example 1

[0067] 1.83 mg of the asaraldehyde-based conjugated chromophore HTTND prepared in Example 1 was dissolved in ethanol to obtain an HTTND solution with a concentration of 5 mmol / L. This solution was then added to gelling gel 1, gelling gel 2, and gelling gel 3, respectively, where the concentration of HTTND was 10 µmol / L. Emission spectra of gelling gel 1 (Haodi), gelling gel 2 (Meitao), and gelling gel 3 (Siyu) with added HTTND solution were then measured at room temperature with an external excitation light source of 440 nm. The resulting emission spectra are shown below. Figure 9 As shown in Table 4, the optical signal intensity and viscosity of different mixed solutions are as follows.

[0068] Table 4. Optical signal intensity and viscosity of different gels

[0069] Depend on Figure 9 As shown in Table 4, the viscosities of the three hair gels differ significantly, resulting in substantial differences in light signal intensity. Specifically, hair gel 1 exhibits the lowest light signal intensity, indicating a thinner consistency, with a viscosity of 1.0 cP. Hair gel 2 displays a medium light signal intensity, indicating a slightly increased consistency, with an overall medium viscosity of 9.8 cP. Hair gel 3 shows a further increase in light signal intensity, indicating a higher overall consistency, with a viscosity of 20.1 cP. These different viscosities indicate significant differences in their final styling ability. Higher viscosity suggests that the hair can maintain its style for a longer period, while lower viscosity indicates that it is more suitable for simpler and easier styling, with a relatively weaker hold. Therefore, users can have a variety of choices. Meanwhile, the test results show that the Acorus tatarinowii extract provided by this invention—the Asarum aldehyde conjugated chromogenic molecular switch (HTTND)—can exhibit light signals of different intensities to gel water with different micro-region viscosities. Its peak emission wavelength is 560nm, which is bright green light, and it has a visual monitoring effect.

[0070] As can be seen from the above embodiments, this invention provides an asaraldehyde-based conjugated chromophore molecule, its preparation method, and its application. The asaraldehyde described in this invention is extracted from natural Acorus tatarinowii, and further conjugated with quinone derivatives to obtain a functional molecule containing a chromophore. The preparation process is achieved in one step, yielding the asaraldehyde-based conjugated chromophore molecule (HTTND). The asaraldehyde-based conjugated chromophore molecule (HTTND) provided by this invention has an alternating single and double bond conjugated structure, exhibiting different rotational states in solutions of varying viscosities, which are then converted into light signals. This enables rapid, efficient, and visual detection of the viscosity (thinness) of micro-regions in gel water. Especially for gel water containing a large amount of pseudoplastic polymers, traditional detection methods mostly rely on shear processes for measurement, which are difficult to handle in measuring the viscosity of shear-thinned fluids. This molecular tool, however, can present the viscosity in situ through varying light signal intensity. Various test results show that the asaraldehyde-based conjugated chromophore molecule (HTTND) has a high sensitivity coefficient (x=0.94), good pH stability, and excellent photostability. Furthermore, this asaraldehyde-based conjugated chromophore (HTTND) exhibits strong solvent resistance, making it suitable for sensing subtle changes in the viscosity of micro-regions in gel water. Moreover, the preparation process of this asaraldehyde-based conjugated chromophore (HTTND) does not involve the addition of any toxic catalysts or heavy metal ions, making it environmentally friendly, easy to operate, and yielding a high final yield. The raw materials are derived from natural products, which are abundant and have high added value, making it suitable for large-scale industrial production applications.

[0071] 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. An asaraldehyde-based conjugated chromophore, characterized in that, It has the structure shown in Equation 1:

2. The method for preparing the asaraldehyde-based conjugated chromophore according to claim 1, characterized in that, Includes the following steps: A quinone derivative solution, a dehydrating agent dispersion, and an asaraldehyde solution were mixed and subjected to a dehydration condensation reaction to obtain an asaraldehyde-based conjugated chromogenic molecule. The quinone derivative in the quinone derivative solution is lanshoquinone.

3. The method for preparing the asaraldehyde-based conjugated chromophore according to claim 2, characterized in that, The solvent for the quinone derivative solution is one or more of methanol, tetrahydrofuran, ethanol, N,N-dimethylformamide, ethyl acetate, and dimethyl sulfoxide. The concentration of the quinone derivative solution is 1–25 M.

4. The method for preparing the asaraldehyde-based conjugated chromophore according to claim 3, characterized in that, The solvent for the dehydrating agent dispersion is one or more of methanol, tetrahydrofuran, ethanol, N,N-dimethylformamide, ethyl acetate, and dimethyl sulfoxide. The dehydrating agent in the dehydrating agent dispersion is one or more of sodium carbonate, cesium carbonate, aluminum hydroxide, sodium bicarbonate, potassium carbonate, potassium bicarbonate, magnesium hydroxide, calcium carbonate, calcium acetate, and tin acetate. The concentration of the dehydrating agent dispersion is 1–600 M.

5. The method for preparing the asaraldehyde-based conjugated chromophore according to claim 3 or 4, characterized in that, The solvent for the asaraldehyde solution is an alcohol solvent; The concentration of the asaraldehyde solution is 1–200 M.

6. The method for preparing the asaraldehyde-based conjugated chromophore according to claim 5, characterized in that, The molar ratio of asaraldehyde in the asaraldehyde solution to the quinone derivatives in the quinone derivative solution is 1 to 50:

1. The molar ratio of the dehydrating agent in the dehydrating agent dispersion to the quinone derivative in the quinone derivative solution is 1–350:

1.

7. The method for preparing the asaraldehyde-based conjugated chromophore according to claim 6, characterized in that, The temperature of the dehydration condensation reaction is 60–100°C, and the time of the dehydration condensation reaction is 1–30 h.

8. The application of the asaraldehyde conjugated chromophore of claim 1 in the measurement of viscosity in gel microareas.

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