Preparation method and application of carvacrol sulfonated derivatives and salts thereof

Abstract

The invention discloses a method for preparing a sulfonated carvacrol derivative and a salt thereof, comprising the following steps: S1: adding carvacrol to a mixed acid for reaction; wherein the mixed acid is a mixture of concentrated sulfuric acid and oleum; S2: adjusting the pH value to 3-6 by taking the reaction solution obtained in step S1, and then filtering; S3: taking the filtrate obtained by filtering step S2, adjusting the pH value to 0.5-1.5, and then cooling and crystallizing to obtain the sulfonated carvacrol derivative crystal. The carvacrol sulfonic acid and its sulfonate obtained by the method can be directly processed into a water-soluble mite-repelling disinfection product in a water system product, avoiding the potential adverse reactions and inconvenience of use caused to the human body by the large-scale use of a solvent, and at the same time, through structural modification, increasing its bactericidal effect.

Description

Technical Field

[0001] The invention relates to a preparation process of a natural product derivative, in particular to a preparation method and application of a sulfonated carvacrol derivative and a salt thereof. Background Art

[0002] Carvacrol, also known as 2-methyl-5-isopropylphenol, is a colorless to light yellow oily liquid with the smell of thymol. It is commonly found in many aromatic plants in nature, such as volatile oils of aromatic Chinese medicines such as oregano, thyme, and agave. It has strong pharmacological activity and health-promoting effects. Carvacrol can be used in food additives, spices, antioxidants, insect repellents, sanitary disinfectants, preservatives, pharmaceutical intermediates, feed additives and other fields. Globally, the carvacrol market is mainly concentrated in North America, Europe, India, Japan, China and other countries and regions. The application market is huge and has a good market demand prospect.

[0003] Carvacrol is an oil-soluble substance and is basically insoluble in water, which affects its use and scope of application. Carvacrol has good antibacterial effects and has antibacterial effects on most Gram-negative bacteria. Its antibacterial mechanism is mainly that carvacrol can bind to phospholipids on the plasma membrane and cause lipid accumulation, thereby destroying the stability and integrity of the membrane and increasing the permeability of the cell membrane to achieve the antibacterial effect. The antibacterial effect of carvacrol on Gram-positive bacteria is better than that on Gram-negative bacteria. The main reason is that the cell wall structure of the two bacteria that wraps the cell outer membrane is different. Gram-negative bacteria are less sensitive to carvacrol than Gram-positive bacteria because their hydrophilic cell wall structure hinders the penetration of hydrophobic compounds through the cell membrane. By improving the structure of carvacrol and introducing sulfonic acid groups, we have greatly increased its water solubility and expanded its scope of application. At the same time, the introduction of sulfonic acid groups has improved the permeability to bacterial cell membranes, and the accumulated H + By combining with the sulfonic acid group, it enters the cell and makes the cell membrane more likely to swell and rupture, thereby enhancing the bactericidal effect on Gram-negative bacteria. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a sulfonated carvacrol derivative and a salt thereof, which greatly improves the water solubility of carvacrol and also enhances its bactericidal ability.

[0005] The objective of the present invention is achieved through the following technical solutions:

[0006] A method for preparing a sulfonated carvacrol derivative and a salt thereof comprises the following steps:

[0007] S1: adding carvacrol to a mixed acid for reaction; wherein the mixed acid is a mixture of concentrated sulfuric acid and fuming sulfuric acid; S2: taking the reaction solution obtained in step S1, adjusting the pH value to 3-6, and then filtering;

[0008] S3: taking the filtrate obtained by filtering in step S2, adjusting the pH value to 0.5-1.5, and then cooling and crystallizing to obtain carvacrol sulfonated derivative crystals.

[0009] Further, in step S1, the oleum contains 15-25% sulfur trioxide;

[0010] And / or, the volume ratio of the concentrated sulfuric acid to oleum is 0.5-2.0:1;

[0011] And / or, the weight ratio of the carvacrol to the mixed acid is 1:3-8.

[0012] Furthermore, in step S1, the reaction temperature is 70-150°C, and the reaction time is 90-150 min. Preferably, the reaction temperature is 90-110°C.

[0013] Furthermore, in step S2, a metal hydroxide solution is used to adjust the pH of the reaction solution, and the metal hydroxide solution includes a barium hydroxide solution or a calcium hydroxide solution;

[0014] Preferably, the pH value is 4-5.

[0015] Furthermore, in step S3, concentrated sulfuric acid is used to adjust the pH value;

[0016] Preferably, the pH value is 0.8-1.2.

[0017] The present invention also provides a method for preparing a salt of a sulfonated derivative of carvacrol, which further comprises:

[0018] S4: taking the reaction solution obtained in step S1, adjusting the pH value to 5-6, then dropping a saturated salt solution for salting out, and filtering to obtain the salt crystals of the sulfonated derivative of carvacrol.

[0019] Furthermore, in step S4, the pH value is adjusted using a sodium carbonate solution.

[0020] Furthermore, in step S4, the saturated salt solution includes a saturated sodium chloride solution or a saturated potassium chloride solution.

[0021] Another object of the present invention is to provide a sulfonated carvacrol derivative or a salt thereof prepared by the above preparation method.

[0022] The invention also discloses the application of the carvacrol sulfonated derivative or its salt in preparing a purifier, a disinfectant, a detoxifying agent, an insecticide or a bactericide.

[0023] The beneficial effects of the present invention are:

[0024] 1. The process of the present invention is simple and the cost is low. Carvacrol is subjected to sulfonation and salt-forming reaction and recrystallization technology to prepare pure carvacrol sulfonic acid and carvacrol sulfonic acid sodium salt, and the purity thereof reaches more than 85%.

[0025] 2. Carvacrol sulfonic acid and its sodium salt improve the water solubility of carvacrol and expand its application range. In water-based products, it can be directly processed into water-soluble anti-mite disinfection products, avoiding the potential adverse reactions and inconveniences caused by the large-scale use of co-solvents to the human body. This has great practical significance for broadening the application of carvacrol in water-based products.

[0026] 3. The carvacrol sulfonic acid and sodium carvacrol sulfonate obtained by the present invention have better bactericidal effects and can effectively kill Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, viruses and other harmful microorganisms. The bactericidal ability thereof is approximately doubled compared with that of carvacrol. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is the H NMR spectrum of carvacrol sulfonic acid;

[0028] Figure 2 is the C NMR spectrum of carvacrol sulfonic acid;

[0029] Figure 3 These are photos of the comparative bactericidal test of carvacrol and carvacrol sulfonic acid in Example 3. DETAILED DESCRIPTION

[0030] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings, but the protection scope of the present invention is not limited to the following.

[0031] Example 1

[0032] A carvacrol sulfonic acid crystal is prepared, and the specific method is as follows:

[0033] (1) Sulfonation reaction of carvacrol: Accurately weigh 300 ml of concentrated sulfuric acid and 300 ml of fuming sulfuric acid, slowly pour them into the reactor, and mix and stir them evenly. Accurately weigh 10 g of carvacrol, add it into the reactor, stir at 90°C until the carvacrol is completely dissolved and the reaction begins, and continue stirring for 120 min before stopping the reaction.

[0034] (2) After the reaction solution is cooled, a saturated barium hydroxide solution is slowly added to adjust the pH to 5.5, and then the mixture is allowed to stand for 2 hours. A clear filtrate is obtained by filtration. The filtrate is added with a 10% sulfuric acid solution to adjust the pH to 1.0, and the mixture is refrigerated overnight. The precipitated crystals are vacuum filtered and dried to obtain a white crude product. The yield of carvacrol sulfonic acid is 79.3%, and the purity reaches 86.2%.

[0035] The obtained carvacrol sulfonic acid was subjected to nuclear magnetic resonance detection, and the H-NMR was obtained as shown in the attached manual. Figure 1 As shown, C-NMR is obtained as shown in the attached manual Figure 2 shown.

[0036] Example 2

[0037] A sodium carvacrol sulfonate crystal is prepared, and the specific method is as follows:

[0038] (1) Sulfonation reaction of carvacrol: Accurately weigh 200 ml of concentrated sulfuric acid and 260 ml of fuming sulfuric acid, slowly pour them into the reactor, and mix and stir them evenly. Accurately weigh 10 g of carvacrol, add it into the reactor, stir at a temperature of 150°C until the carvacrol is completely dissolved and the reaction begins. Continue stirring for 120 minutes and then stop the reaction.

[0039] (2) Slowly add saturated sodium carbonate solution to the reaction solution to adjust the pH to 5.0, then slowly drop 500 ml of saturated sodium chloride solution, and then stand at refrigerated temperature for 24 hours to precipitate a self-colored precipitate. Filter by suction, and wash the precipitate with saturated sodium carbonate aqueous solution until it is neutral. Dry to obtain sodium carvacrol sulfonate crystals. The yield of sodium carvacrol sulfonate is 75.8%, and the purity reaches 91.6%.

[0040] Example 3

[0041] The bactericidal comparison test of carvacrol and carvacrol sulfonic acid is as follows:

[0042] ①MIC test of carvacrol and its derivatives:

[0043] Take 48 sterile test tubes and divide them into three groups of 16 in each group and arrange them with numbers. Add 2.5 mL of the prepared sterile nutrient broth to each test tube. Add 7.5 mL of 5 mg / mL carvacrol solution prepared with sterile nutrient broth to the first tube of the first group. Mix well and then pipette 7.5 mL into the second tube. Mix well and then pipette 7.5 mL into the third tube. Repeat this step until the 14th tube. Then add 0.1 mL of the prepared bacterial suspension to each tube. 5.0×10 5CFU / mL bacterial suspension, at this time, the concentration of the test drug in each tube is 4.050mg / ml, 3.037mg / ml, 2.196mg / ml, 1.641mg / ml, 1.230mg / ml, 0.923mg / ml, 0.692mg / ml, 0.519mg / ml, 0.389mg / ml, 0.292mg / ml, 0.219mg / ml, 0.164mg / ml, 0.123mg / ml, 0.092mg / ml, the 15th and 16th tubes are positive control tubes containing only an equal amount of bacterial solution without samples and negative control tubes containing neither samples nor bacterial solution. The test tubes were placed in a 37℃ constant temperature shaking incubator for 16-18h. The lowest acidifier concentration in the test tube that confirmed sterile growth by naked eye observation is the minimum inhibitory concentration. Using an ultraviolet spectrophotometer, with the blank group as a calibration reference, the growth of the four bacteria in samples with different concentration gradients was detected at a wavelength of 580-600nm. The lowest dilution concentration without bacterial growth was the minimum inhibitory concentration (MIC). The second group used carvacrol sulfonic acid, and the third group used sodium carvacrol sulfonate. The test steps were the same as above, and the test results are shown in the following table:

[0044] Table of antibacterial test of carvacrol and its sulfonic acid derivatives

[0045]

[0046] ②Comparative experiment of carvacrol and its carvacrol sulfonic acid MBC

[0047] From each test tube with MIC of various concentrations of carvacrol and carvacrol sulfonic acid and concentrations higher than MIC, 100 μL of culture was taken out and inoculated into agar medium. The culture was placed in a constant temperature incubator at 37°C for 48 hours. The lowest acidifier concentration at which no colonies were grown by naked eye observation was the minimum bactericidal concentration.

[0048]

[0049] Example 4

[0050] The carvacrol sulfonic acid prepared in Example 1 and the sodium carvacrol sulfonate prepared in Example 2 were prepared into a 0.1% solution, and the contact killing activity of mites was tested by the glass slide immersion method (with 0.1% carvacrol as the control group). The specific method is as follows:

[0051] Each raw material was set to 5 to 7 concentrations, and each concentration was repeated 3 times, with no less than 45 test mites in each repetition. The female adult mites to be tested were picked up on the double-sided tape on the glass slide, with their backs facing down, and placed in an environment with a temperature of (26±1)℃ and 70% to 85% RH for 2 hours. Dead or injured individuals were removed under a binocular dissecting microscope, and the number of live mites was recorded. The glass slide with live mites was soaked in the prepared solution for 5 seconds and then taken out. The excess solution around the test mites was quickly absorbed with filter paper. Cultivated under the same feeding conditions, the mortality was checked 12 hours after treatment, and the mortality rate and corrected mortality rate were calculated. The mite body was lightly touched with a brush, and those with motionless appendages were considered dead. The corrected mortality rate was converted into probability values, and the concentration was converted into logarithms for linear regression. The LC50 and regression equation were calculated using the probability value analysis method, and the results are as follows:

[0052] Comparison table of contact test of carvacrol and its derivatives against mites

[0053]

[0054]

[0055] Example 5

[0056] Several downstream products of Sodium Carvacrol Sulfonate are available.

[0057] 1) According to the formula, dandelion extract, chrysanthemum extract, wormwood extract, tea polyphenols, mangosteen peel extract, nanosilver, emulsifier and other substances are weighed and uniformly mixed to obtain a mixed solution. 1-2g of the pure sodium carvacrol sulfonate prepared in Example 2 is accurately weighed and added to the mixed solution to fully stir and dissolve. Then, deionized water is added to 1000ml to obtain a disinfection spray liquid for pet mite repellent and sterilization.

[0058] 2) According to the product formula, weigh fatty alcohol polyoxyethylene ether sodium sulfate, sodium lauryl sulfate, coconut oil fatty acid diethanolamide, cocamidopropyl betaine, guar hydroxypropyltrimethylammonium chloride, glycerol, D-panthenol, soapberry extract, white willow extract, Platycladus orientalis extract, mangosteen peel extract, disodium ethylenediaminetetraacetic acid, citric acid, sodium chloride and other substances respectively, mix and dissolve evenly according to the formula, accurately weigh 1-2g of the pure sodium carvacrol sulfonate prepared in Example 2, add the mixed liquid to fully dissolve, and then add deionized water to 1000mL to obtain a pet mite repellent and antibacterial shower gel product.

[0059] Example 6

[0060] Comparative Example 1: Pure carvacrol (purity 85% origin: Jishui County Shengyuan Spice Factory)

[0061] Samples of carvacrol sulfonic acid crystals (purity 86.2%) and carvacrol sodium sulfonate crystals (purity 91.6%) were dissolved in water to conduct a comparative test of water solubility and bactericidal effect. The experimental results are as follows:

[0062]

[0063]

[0064] In the above experiment, solubility refers to the mass of the sample dissolved in every 100 mL of pure water, and the antibacterial and bactericidal effect is carried out in accordance with the method of "Laboratory Bactericidal Effect Test Method of Disinfectants (GB / T38502-2020)".

[0065] The above is only a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art shall not deviate from the spirit and scope of the present invention, and shall be within the scope of protection of the claims attached to the present invention.

Claims

1. A method for preparing a sulfonated derivative of carvacrol, characterized in that: The following steps are involved: S1: adding carvacrol to a mixed acid for reaction; wherein the mixed acid is a mixture of concentrated sulfuric acid and oleum; S2: taking the reaction solution obtained in step S1, adjusting the pH value to 3-6, and then filtering; S3: taking the filtrate obtained by filtering in step S2, adjusting the pH value to 0.5-1.5, and then cooling and crystallizing to obtain carvacrol sulfonated derivative crystals; S4: adjusting the pH value of the reaction solution obtained in step S1 to 5-6, then dropping a saturated salt solution for salting out, and filtering to obtain the salt crystals of the sulfonated derivative of carvacrol; In step S1, the oleum contains 15-25% sulfur trioxide; The volume ratio of the concentrated sulfuric acid to oleum is 0.5-2.0:1; In step S1, the reaction temperature is 70-150°C, and the reaction time is 90-120min; In step S2, the pH value of the reaction solution is adjusted using a barium hydroxide solution.

2. A method for preparing a salt of a sulfonated derivative of carvacrol, characterized in that: The method comprises adopting step S1 described in claim 1; and further comprising: S4: taking the reaction solution obtained in step S1, adjusting the pH value to 5-6, then dropping a saturated salt solution for salting out, and filtering to obtain the salt crystals of the sulfonated derivative of carvacrol.

3. The preparation method according to claim 2, characterized in that: In step S4, sodium carbonate solution is used to adjust the pH value.

4. The preparation method according to claim 2, characterized in that: In step S4, the saturated salt solution includes a saturated sodium chloride solution or a saturated potassium chloride solution.

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