WO2021052272A1 - Magnolol derivative, preparation method therefor, and use thereof - Google Patents

Abstract

The present invention relates to the field of magnolol derivatives, and specifically relates to magnolol, a preparation method therefor, and the use thereof. Disclosed is a magnolol derivative having a structure as shown in formula (I). The provided magnolol derivative has a good water solubility, is colorless and transparent after dissolution, has a significant inhibitory effect on common Escherichia coli, Staphylococcus aureus etc., and can be used in the fields of food, medicine, cosmetics etc. as a green and natural preservative.

Description

Magnolol derivative and its preparation method and application

Cross-references to related applications

This application claims the rights and interests of the Chinese patent application 201910894284.6 filed on September 20, 2019, the content of which is incorporated herein by reference.

Technical field

The present invention relates to the field of magnolol derivatives, in particular to magnolol derivatives and preparation methods and applications thereof.

Background technique

Foods, medicines and cosmetics are rich in water and various nutrients, which provide a good growth environment for microorganisms. In addition, the intrusion of microorganisms is inevitable during the production and use of cosmetics, which makes them extremely prone to spoilage and deterioration, leading to product quality. Decline, posing a threat to the health of users. Adding preservatives to cosmetics is an important means to protect products from microbial contamination, extend product shelf life, and ensure product safety.

At present, there are many kinds of preservatives used in food, medicine and cosmetics, most of which are chemical preservatives. There are dozens of commonly used preservatives, including acidic preservatives (benzoic acid) and ester preservatives (parabens) Wait. However, with the development of science and the continuous improvement of consumer safety awareness, people have gradually discovered that although the antiseptic effect of chemical preservatives is very good, some chemical preservatives have adverse effects on the human body, causing skin allergies and lowering body functions. And cause pollution to the environment. Therefore, natural preservatives are urgently needed by various industries. A natural preservative with low toxicity, low irritation and high performance is of great significance in the fields of food, medicine and cosmetics.

Magnolia officinalis cortex (Magnolia officinalis cortex) is the dry bark, root bark and branches of Magnolia officinalis Rehd.et Wils. It is an important Chinese medicinal material and is listed as a medium product in "Shen Nong's Herbal Classic". Magnolia officinalis tastes bitter and pungent, has a warm nature, and has the effects of promoting qi, dissipating dampness, relieving pain, reducing adverse effects and reducing asthma. The main chemical active ingredients of Magnolia officinalis are lignans, magnolol, honokiol and so on. The phenols in Magnolia officinalis have antibacterial, anti-tumor, analgesic and anti-inflammatory effects. However, due to its poor water solubility, it is easy to oxidize and deteriorate, which greatly hinders the application of magnolol in foods, health products, medicines and cosmetics. Generally, conventional surfactants and emulsifiers can be used to solubilize magnolol. In this case, not only the amount of surfactants and emulsifiers required is very large, but also even if it is used in liquid formulations, magnolol will also It separates out from the water system formula, causing the entire system to become turbid, which seriously affects the use. In addition, a small amount of alkali can be added to the formulation system to turn magnolol into a salt and increase its water solubility. However, the magnolol salt formed by this method is extremely unstable and easily turns golden yellow, resulting in electrical conductivity of the system. Increased rate and decreased bacteriostatic capacity. The above methods have very high requirements on the accuracy of the pH, thickener and emulsifier dosage of the product formulation system, which makes it difficult to industrially apply.

The traditional method of increasing the solubility of magnolol will introduce impurity compounds into the original system, and make magnolol unstable after being dissolved in the aqueous system, resulting in the system being prone to deterioration and reducing the antibacterial ability. Therefore, modifying the structure of magnolol to improve the solubility and antibacterial ability of magnolol in water is an urgent problem in the application of magnolol as a natural preservative in food, medicine and cosmetics.

Summary of the invention

The purpose of the present invention is to overcome the problems of poor water solubility of magnolol and decreased antibacterial ability after being dissolved in an aqueous system, and to provide a magnolol derivative and a preparation method and application thereof. The water-soluble magnolol derivative provided by the invention has excellent stability and antibacterial ability when used in preservatives.

In order to achieve the above objective, in the first aspect, the present invention provides a magnolol derivative, which has a structure represented by formula (1):

Wherein, in formula (1), R ₁ , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are each independently selected from hydrogen, halogen, substituted or unsubstituted C ₁ -C ₁₀ alkyl, substituted Or an unsubstituted C ₁ -C ₁₂ alkoxy group, a substituted or unsubstituted C ₆ -C ₁₀ aryl group.

Preferably, the _{optional substituents on R 1} , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are each independently selected from halogen, C ₁ -C ₆ alkoxy and C ₆ -C ₁₀ Aryl.

Preferably, R ¹ , R ² , R ³ and R ⁴ are each independently selected from hydrogen, halogen, SO ₃ ^- and C ₁ -C ₃ alkyl.

In the second aspect, the present invention provides a method for preparing magnolol derivatives, the method comprising the following steps: in the presence of a phase transfer catalyst, the compound having the structure of formula (2) and bisulfite and/or sulfite Sulfate undergoes a contact reaction,

Wherein, in formula (2), R ₁ , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are each independently selected from hydrogen, halogen, substituted or unsubstituted C ₁ -C ₁₀ alkyl, substituted Or an unsubstituted C ₁ -C ₁₂ alkoxy group, a substituted or unsubstituted C ₆ -C ₁₀ aryl group.

Preferably, the _{optional substituents on R 1} , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are each independently selected from halogen, C ₁ -C ₆ alkoxy and C ₆ -C ₁₀ Aryl.

In the third aspect, the present invention also provides the use of the magnolol derivative described in the aforementioned first aspect or the magnolol derivative prepared by the method described in the aforementioned second aspect in bacteriostasis.

By modifying the structure of magnolol, the present invention prepares a modified magnolol derivative that can be used for bacteriostasis, which has good water solubility, is colorless and transparent after dissolution, and is resistant to common gram-negative bacteria and leather. Langerhans-positive bacteria, fungi, etc. have significant inhibitory effects, and can be used as green and natural preservatives in the fields of food, medicine and cosmetics.

Other features and advantages of the present invention will be described in detail in the following specific embodiments.

detailed description

The following is a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described here are only used to illustrate and explain the present invention, and not to limit the present invention.

The endpoints and any values of the ranges disclosed herein are not limited to the precise range or value, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, between the end values of each range, between the end values of each range and individual point values, and between individual point values can be combined with each other to obtain one or more new numerical ranges. These values The scope should be considered as specifically disclosed herein.

The following explains some terms involved in the present invention:

"C ₁ -C ₁₀ alkyl group" means an alkyl group with a total number of carbon atoms of 1-10, including straight-chain alkyl, branched-chain alkyl or cycloalkyl, for example, the total number of carbon atoms is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 linear alkyl, branched alkyl or cycloalkyl, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, iso Butyl, tert-butyl, n-pentyl, isopentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, cyclopropyl, methylcyclopropyl, ethylcyclopropyl, Cyclopentyl, methylcyclopentyl, cyclohexyl, etc.

"C ₁ -C ₁₂ alkoxy group" means an alkoxy group with a total number of carbon atoms of 1-12, including straight-chain alkoxy groups, branched-chain alkoxy groups, and cycloalkoxy groups. Specifically, the total number of carbon atoms is 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 linear alkoxy, branched alkoxy or cycloalkoxy, for example, methoxy, ethoxy , N-propoxy, isopropoxy, n-butoxy, isobutoxy, tert-butoxy, n-pentoxy, isopentoxy, n-hexoxy, n-heptoxy, n-octyloxy, N-nonyloxy, n-decyloxy, cyclopropoxy, methylcyclopropoxy, ethylcyclopropoxy, cyclopentyloxy, methylcyclopentyloxy, cyclohexyloxy, etc.

"C ₆ -C ₁₀ aryl group" means an aryl group with a total number of carbon atoms of 6-10, and at least one H on the benzene ring of the aryl group is substituted with a C ₁ -C ₄ alkyl group, such as tolyl and ethylphenyl , N-propyl phenyl, cumyl phenyl, n-butyl phenyl, o-xylyl, m-xylyl, p-xylyl, etc.

The definitions of other similar groups herein refer to the aforementioned definitions herein, and only differ in the number of carbon atoms or the way of isomerization.

In the first aspect, the present invention provides a magnolol derivative, which has a structure represented by formula (1):

Wherein, in formula (1), R ₁ , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are each independently selected from hydrogen, halogen, substituted or unsubstituted C ₁ -C ₁₀ alkyl, substituted Or an unsubstituted C ₁ -C ₁₂ alkoxy group, a substituted or unsubstituted C ₆ -C ₁₀ aryl group.

Preferably, the _{optional substituents on R 1} , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are each independently selected from halogen, C ₁ -C ₆ alkoxy and C ₆ -C ₁₀ Aryl.

Preferably, R ¹ , R ² , R ³ and R ⁴ are each independently selected from hydrogen, halogen, SO ₃ ^- and C ₁ -C ₃ alkyl.

According to a preferred embodiment of the present invention, in formula (1), R ₁ , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are each independently selected from hydrogen, fluorine, chlorine, bromine, substituted or unsubstituted A substituted C ₁ -C ₅ alkyl group, a substituted or unsubstituted C ₁ -C ₆ alkoxy group, a substituted or unsubstituted C ₆ -C ₈ aryl group. Among them, the C ₆ -C ₈ aryl group may be, for example, one of phenyl, methyl phenyl, o-dimethyl phenyl, m-dimethyl phenyl, p-dimethyl phenyl, and ethyl phenyl. .

Preferably, the _{optional substituents on R 1} , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are each independently selected from fluorine, chlorine, bromine, C ₁ -C ₃ alkoxy, C ₆ -C ₈ aryl group.

^{Preferably, R 1, R 2, R} 3 and R ⁴ are each independently selected from hydrogen, fluoro, chloro, bromo, SO ₃ ^-, methyl, ethyl and n-propyl.

Preferably, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are all hydrogen.

^{Preferably, R 1, R 2, R} 3 and R ⁴ are each independently selected from hydrogen and SO ₃ ^-.

According to a preferred implementation method of the present invention, the compound of the structure represented by formula (1) is selected from at least one of the following compounds:

The inventors of the present invention found that the magnolol derivative involved in this embodiment has more excellent water solubility and antibacterial ability.

In a second aspect, the present invention provides a method for preparing magnolol derivatives, which includes the following steps: in the presence of a phase transfer catalyst, a compound having a structure of formula (2) is combined with bisulfite and/or Sulfite undergoes a contact reaction,

Wherein, in formula (2), R ₁ , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are each independently selected from hydrogen, halogen, substituted or unsubstituted C ₁ -C ₁₀ alkyl, substituted Or an unsubstituted C ₁ -C ₁₂ alkoxy group, a substituted or unsubstituted C ₆ -C ₁₀ aryl group.

Preferably, the _{optional substituents on R 1} , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are each independently selected from halogen, C ₁ -C ₆ alkoxy and C ₆ -C ₁₀ Aryl.

In the present invention, the substituents optionally present on _{R 1} , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ and R ₁ , R ₂ , R ₃ , R ₄ , R ₅ and R _{6 are preferred} The range is the same as the preferred range of the corresponding group in the aforementioned first aspect, and will not be repeated here.

According to the present invention, the type of the bisulfite and/or sulfite is not particularly limited, and can be conventionally selected in the field, preferably NaHSO ₃ , KHSO ₃ , Na ₂ SO ₃ , K ₂ SO ₃ , NH ₄ HSO ₃ , (NH ₄ ) ₂ SO ₃ ﹒ At least one of H _{2 O.}

The molar ratio of the bisulfite and/or sulfite to the compound having the structure of formula (2) is (0.5-4):1, preferably (1-2.5):1.

The present invention does not particularly limit the phase transfer catalyst, which can be conventionally selected in the field, for example, quaternary ammonium salt compounds, quaternary phosphonium salt compounds, crown ether compounds, and preferably quaternary ammonium salt compounds. The present invention does not specifically limit the quaternary ammonium salt compound, which can be a conventional choice in the field. Preferably, the quaternary ammonium salt compound is selected from the group consisting of tetramethylammonium chloride, tetramethylammonium bromide, and tetraethyl Ammonium bromide, tetraethyl ammonium chloride, tetrapropyl ammonium bromide, tetrapropyl ammonium chloride, tetrabutyl ammonium bromide, tetrabutyl ammonium chloride, tetrabutyl ammonium hydrogen sulfate, tetra n-butyl Ammonium sulfate, trioctyl methyl ammonium chloride, trioctyl methyl ammonium bromide, benzyl trimethyl ammonium chloride, benzyl trimethyl ammonium bromide, benzyl triethyl ammonium chloride, benzyl Triethylammonium bromide, dodecyltrimethylammonium chloride, dodecyltrimethylammonium bromide, dodecyltrimethylammonium hydrogen sulfate, tetradecyltrimethylammonium chloride , At least one of tetradecyl trimethyl ammonium bromide and tetradecyl trimethyl ammonium hydrogen sulfate.

In the present invention, the weight ratio of the quaternary ammonium salt compound to the compound having the structure of formula (2) is (0.05-0.5):100, preferably (0.1-0.3):100.

In the present invention, the conditions of the contact reaction include: the temperature is 40-100°C, preferably 60-80°C; the contact time is 4-12h, preferably 5-8h.

According to the present invention, the contact reaction is carried out in the presence of water and an organic solvent. The organic solvent is not particularly limited in the present invention. The organic solvent may be alkanes, alcohols, esters or ethers. At least one of methyl chloride, chloroform, N,N-dimethylformamide, and diethyl ether, more preferably methanol.

Preferably, in the entire reaction system, the volume ratio of water to the organic solvent is 1:(1-6), preferably 1:(3-5).

According to the present invention, preferably, the method further includes optionally evaporating the product obtained by the contact reaction, and then successively performing crystallization, filtration, and freeze-drying to obtain the magnolol derivative to be prepared. The present invention does not specifically limit the evaporation operation, which can be conventionally selected in the field, and it is preferable to use a rotary evaporator to remove most of the organic solvents. The present invention does not specifically limit the crystallization operation, which can be a conventional operation in the field. The crystallization solvent is selected from at least one of acetone, ethanol, isopropanol, and ethyl acetate, preferably ethanol and/or isopropanol. The present invention does not specifically limit the filtration and freeze-drying operations, which can be conventionally selected in the field.

In the present invention, the compound represented by formula (2) is derived from plant extracts. The plant in the present invention is Magnolia officinalis. In the extract, the content of the compound having the structure of formula (2) is ≥ 80% by weight.

In a third aspect, the present invention provides the use of the magnolol derivative described in the foregoing first aspect or the magnolol derivative prepared by the method described in the foregoing second aspect in bacteriostasis.

The magnolol derivatives provided by the present invention can be used in foods, medicines and cosmetics, as preservatives or preservative components, for common Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, white Candida, Aspergillus niger, etc. have inhibitory effects. The amount of the magnolol derivative is 0.001-0.01 g per gram of the food, medicine or cosmetic.

Hereinafter, the present invention will be described in detail through examples.

In the following examples, the molecular structure of the prepared magnolol derivative was measured by a time-of-flight mass spectrometer and a nuclear magnetic resonance spectrometer. The model of the flight mass spectrometer is HREI-TOFMS, purchased from Kore, UK; nuclear magnetic resonance spectrometer The model is Thermo Fisher’s picoSpin80, purchased from Thermo Fisher; the LC/MS model is TSQ Altis triple quadrupole mass spectrometer, purchased from Thermo Fisher; the plant-derived thick The naphthol content is 90%, purchased from Hunan Jiamu Biological Technology Co., Ltd.; the dodecyltrimethylammonium chloride and benzyltriethylammonium chloride used are purchased from Shanghai Macleans Bioreagent Co., Ltd.; nutrient broth Purchased from Beijing Mindray Technology Co., Ltd., the main ingredients are peptone, beef extract, sodium chloride and water; TTC is the abbreviation of 2,3,5-triphenyltetrazolium chloride, and the TTC reagents used are purchased from Shanghai Yuanye Biology Technology Co., Ltd.; methyl paraben is analytical grade, purchased from Shanghai Macleans Biochemical Technology Co., Ltd.; phenoxyethanol is analytical grade, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd. Among them, Escherichia coli: ATCC 8739 4th generation, purchased from Guangdong Institute of Microbiology; Staphylococcus aureus: ATCC 6538, 4th generation, purchased from Guangdong Institute of Microbiology; Verdigris Pseudomonas aeruginosa: ATCC 9027, 6th generation, purchased from Guangdong Institute of Microbiology; Candida albicans: ATCC8327, 4th generation, purchased from Guangdong Institute of Microbiology; Aspergillus niger: The 4th generation of ATCC5478 was purchased from Guangdong Institute of Microbiology; Sabouraud culture medium was purchased from Shandong West Asia Chemical Industry Co., Ltd.

Example 1

Weigh 10g of plant-derived magnolol (90% by weight) and dissolve it in 40ml of methanol by ultrasonic, which is the methanol phase; weigh 3.9g of sodium bisulfite and dissolve it into 14ml of deionized water, and add 0.01g Alkyl trimethyl ammonium chloride is the water phase. Slowly put the water phase and methanol phase into a 250ml three-necked flask and mix, control the adding speed to 4ml/min, magnetically stir, and rotate at 450rmp/min. The reaction temperature is about 60°C, and the reaction time is 8h. The excess methanol was removed by a rotary evaporator, recrystallized in isopropanol at low temperature, filtered and then lyophilized to obtain magnolol derivatives. The yield was 40% based on magnolol in the reaction raw materials. It was characterized by a flight mass spectrometer and a nuclear magnetic resonance instrument, and it was confirmed to be a magnolol derivative with the structure represented by formula (1) of the present invention. The reaction mechanism is as follows:

Example 2

Weigh 10g of plant-derived magnolol (90% content) and dissolve it in 40ml methanol by ultrasonic, which is the methanol phase; weigh 5.1g of ammonium sulfite monohydrate and dissolve it into 8ml of deionized water, and add 0.02g of benzyl Triethylammonium chloride is the water phase. Slowly put the water phase and methanol phase into a 250ml three-necked flask and mix, control the adding speed to 4ml/min, magnetically stir, and rotate at 450rmp/min. The reaction temperature is about 80°C, and the reaction time is 5h. The excess methanol was removed by a rotary evaporator, recrystallized in isopropanol at low temperature, filtered and lyophilized to obtain magnolol derivatives. The yield was 28% based on magnolol in the reaction raw materials. It was characterized by a flight mass spectrometer and a nuclear magnetic resonance instrument, and it was confirmed to be a magnolol derivative of the structure represented by formula (1) of the present invention. The reaction mechanism is as follows:

Example 3

It was carried out according to the method of Example 1, except that the reaction time of 1.5h was used instead of the reaction time of 8h, and the others were the same as in Example 1.

Based on magnolol in the reaction raw material, the yield was 54%. It was characterized by a flight mass spectrometer and a nuclear magnetic resonance instrument, and it was confirmed that the product of this example was a magnolol derivative with the structure shown in formula (1), and the structural formula was:

Example 4

It was carried out according to the method of Example 1, except that the reaction time of 6h was used instead of the reaction time of 8h, and the others were the same as in Example 1.

Based on magnolol in the reaction raw materials, the yield was 32%. It was characterized by a flight mass spectrometer and a nuclear magnetic resonance instrument, and it was confirmed that the product of this example was a magnolol derivative with the structure shown in formula (1), and the structural formula was:

Example 5

It was carried out according to the method of Example 1, except that the reaction time of 12h was used instead of the reaction time of 8h, and the others were the same as in Example 1.

Based on magnolol in the reaction raw material, the yield was 73%. It was characterized by a flight mass spectrometer and a nuclear magnetic resonance instrument, and it was confirmed that the product of this example was a magnolol derivative with the structure shown in formula (1), and the structural formula was:

Example 6

It was carried out according to the method of Example 1, except that instead of adding magnolol, the magnolol compound represented by formula (2) was used, and in formula (2), R ₁ , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are methyl, hydrogen, chlorine, hydrogen, hydrogen, and methoxy in this order, and the others are the same as in Example 1.

Based on the magnolol compound represented by formula (2) in the reaction raw material, the yield of the magnolol derivative was 36%. It was characterized by flight mass spectrometry and nuclear magnetic resonance, and the characterization results confirmed that the product prepared in this example is a magnolol derivative of the structure represented by formula (1) of the present invention (wherein, R ¹ and R ³ are both hydrogen; R ² and R ⁴ are both NaO ₃ S-, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are methyl, hydrogen, chlorine, hydrogen, hydrogen and methoxy in order).

Example 7

It was carried out according to the method of Example 1, except that instead of adding magnolol, the magnolol compound represented by formula (2) was used, and in formula (2), R ₁ , R ₂ , R ₃ , R ₄ and R ₅ are all hydrogen, R ₆ is n-heptyl, and the others are the same as in Example 1.

Based on the magnolol compound represented by formula (2) in the reaction raw material, the yield of the magnolol derivative was 21%. It was characterized by flight mass spectrometry and nuclear magnetic resonance, and the characterization results confirmed that the product prepared in this example is a magnolol derivative of the structure represented by formula (1) of the present invention (wherein, R ¹ and R ³ are both hydrogen; R ² and R ⁴ are both NaO ₃ S-, R ₁ , R ₂ , R ₃ , R ₄ , and R ₅ are all hydrogen, and R ₆ is n-heptyl).

Example 8

It was carried out according to the method of Example 1, except that the molar ratio of the sodium bisulfite to the magnolol was 4:1, and the others were the same as in Example 1.

Based on magnolol in the reaction raw materials, the yield was 28%. It was characterized by a flight mass spectrometer and a nuclear magnetic resonance instrument, and it was confirmed that the product of this example was a magnolol derivative with the structure represented by formula (1), and its structural formula was the same as that of example 1.

Example 9

It was carried out according to the method of Example 1, except that the weight ratio of the dodecyltrimethylammonium chloride to the magnolol was 0.5:100, and the others were the same as in Example 1.

Based on magnolol in the reaction raw material, the yield was 21%. It was characterized by a flight mass spectrometer and a nuclear magnetic resonance instrument, and it was confirmed that the product of this example was a magnolol derivative with the structure represented by formula (1), and its structural formula was the same as that of example 1.

Example 10

It was carried out according to the method of Example 1, except that the reaction temperature was 85° C., and the others were the same as in Example 1.

Based on magnolol in the reaction raw materials, the yield was 45%. It was characterized by a flight mass spectrometer and a nuclear magnetic resonance instrument, and it was confirmed that the product of this example was a magnolol derivative with the structure represented by formula (1), and its structural formula was the same as that of example 1.

Test case 1

Solubility test method: Measure 25±1℃ with a graduated cylinder, and place 100g deionized water into a 250ml beaker. Put it into a magnetic stirrer and adjust the speed to 200 rpm/min. Weigh magnolol and the samples in Examples 1-10 with an analytical balance, and dissolve 0.1 g each time in deionized water until they cannot be completely dissolved after stirring for 10 minutes, and record the maximum dissolved mass. The results are shown in Table 1.

Test case 2

The samples of magnolol derivatives prepared in Examples 1-10 were used as test samples to quantitatively test the MIC value of the minimum inhibitory concentration. A 10% by weight magnolol ethanol solution, traditional chemical preservatives methyl paraben and phenoxyethanol were used as comparative examples.

The minimum inhibitory concentration MIC value test method is: use sterilized nutrient broth (used to cultivate Escherichia coli and Staphylococcus aureus as the diluent, and use the two-fold dilution method to dilute the test samples respectively, and then The bacteria were inoculated at the concentrations shown in Table 2. The bacteria were cultured at 35°C for 36 hours. 3 hours before the end of the culture, TTC reagent was added and the culture continued. If the culture solution turns red, it is deemed that this concentration cannot inhibit the growth of microorganisms; if the culture solution If it does not turn red, it is considered that the minimum concentration of the drug in the culture solution that does not turn red is the minimum inhibitory concentration of the bacteriostatic agent against the microorganism. The specific results are shown in Table 3.

Test case 3

The magnolol derivative samples prepared in Examples 1-10 were added to the spray formulation in Table 4 below or a similar spray formulation. Inoculate a certain number of bacteria at intervals of 0 days, 7 days, 14 days, 21 days, and 28 days to detect changes in the number of microorganisms in accordance with the detection method of the USP32<51> Microbial Antiseptic Efficacy Test. The specific test results of the samples of Examples 2 and 5-7 are shown in Table 5. The test results of the magnolol derivatives prepared in the other Examples 1, 3-4 and 8-10 (all use the spray formula of Table 4 below) are similar , Are all qualified.

Table 1

sample	Solvent water (100g)
Magnolol	-
Example 1	＞1.25g
Example 2	＞1.2g
Example 3	＞0.5
Example 4	＞0.5

Example 5	＞1
Example 6	＞0.8
Example 7	＞0.5
Example 8	＞1.25
Example 9	＞1.25
Example 10	＞1.25

Note: --- means that 0.1g can not be completely dissolved;> means that the sample is completely dissolved

Table 2

Bacteria	Escherichia coli	Staphylococcus aureus
Concentration of bacterial solution (cfu/mL)	1×10 7	1×10 8

table 3

MIC(%)	Escherichia coli	Staphylococcus aureus
10% by weight magnolol ethanol solution	1.33	0.0053
Methyl paraben	0.156	0.078
Phenoxyethanol	0.25	0.125
Example 1	1.25	1.25
Example 2	0.063	0.016
Example 3	＞0.5	＞0.5
Example 4	＞0.5	＞0.5
Example 5	0.16	0.08
Example 6	0.64	0.64
Example 7	1.25	0.64
Example 8	1.25	1.25
Example 9	1.25	1.25
Example 10	1.25	1.25

Note:> indicates that it has a certain antibacterial ability when adding the corresponding concentration of antibacterial agent, and can be used in combination with other antibacterial agents

Table 4

raw material	Content, weight
Butanediol	2.4%
Betaine	0.04%
Dipotassium Glycyrrhizinate	0.05%
Soluble proteoglycan	0.05%
Royal jelly extract (purchased from Katakura Industry Co., Ltd.)	0.05%
Magnolol derivative (prepared in Example 2)	2.5%
water	margin
Citric acid	Adjust pH=6-7

table 5

Note: The logarithmic decrease value refers to the change of the total amount of microorganisms (ie: the difference between the initial logarithmic value and the logarithmic value after a certain period of time). The larger the number, the stronger the antibacterial ability.

It can be seen from the data in Table 1 that in the qualitative solubility test, the magnolol derivative prepared by the present invention exhibits excellent water solubility. In 100 g of solvent water, the solubility of the sample in Example 1 is greater than 0.42 g. The solubility of the sample in Example 2 is greater than 1.2 g, that is, all the samples measured in Examples 1-10 have been dissolved, and the magnolol extracted from the plant is insoluble in water.

From the data in Table 3, it can be seen that the magnolol derivatives prepared in Examples 1-10 of the present invention all have good antibacterial activity. Among them, the magnolol derivatives prepared in Example 2 have an effect on Escherichia large intestine. The bacteriostasis and Staphylococcus aureus have excellent bacteriostatic effects. The bacteriostatic effect is equivalent to that of the traditional chemical preservatives methyl paraben and phenoxyethanol. The magnolol derivatives prepared in Examples 5-7 are Both of S. aureus and Staphylococcus aureus have excellent bacteriostasis.

The spray formula in Table 4 provides a very suitable environment for the survival of bacteria and fungi. Under such harsh conditions, the samples prepared in Examples 1-10 of the present invention show excellent bacteriostatic ability. From the data in Table 5, It can be seen that after 28 days of spray anti-corrosion challenge test of the aqueous formulation, the modified magnolol in Examples 2, 5, 6, and 7 passed the anti-corrosion challenge test as a preservative. The test results are similar.

Since magnolol itself does not dissolve in water, it is difficult to test the antibacterial effect. Although the antibacterial effect of the ethanol solution of 10% by weight of magnolol is very good, but the national standards have strict restrictions on the amount of ethanol in cosmetics, so it cannot be used industrially.

Using the method of the present invention to modify magnolol, the magnolol derivatives obtained in the examples have excellent water solubility, which effectively improves the solubility of magnolol in water; The Escherichia coli, Staphylococcus aureus, etc. have a significant inhibitory effect.

The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the scope of the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, including the combination of various technical features in any other suitable manner. These simple modifications and combinations should also be regarded as the disclosed content of the present invention. All belong to the protection scope of the present invention.

Claims (16)

1. A magnolol derivative having the structure shown in formula (1):

   

   Wherein, in formula (1), R ₁ , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are each independently selected from hydrogen, halogen, substituted or unsubstituted C ₁ -C ₁₀ alkyl, substituted Or an unsubstituted C ₁ -C ₁₂ alkoxy group, a substituted or unsubstituted C ₆ -C ₁₀ aryl group;

   The _{optional substituents on R 1} , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are each independently selected from halogen, C ₁ -C ₆ alkoxy and C ₆ -C ₁₀ aryl;

   R ¹ , R ² , R ³ and R ⁴ are each independently selected from hydrogen, halogen, SO ₃ ^- and C ₁ -C ₃ alkyl.
2. The magnolol derivative according to claim 1, wherein, in formula (1), R ₁ , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are each independently selected from hydrogen, fluorine, chlorine, Bromine, substituted or unsubstituted C ₁ -C ₅ alkyl, substituted or unsubstituted C ₁ -C ₆ alkoxy, substituted or unsubstituted C ₆ -C ₈ aryl;

   The _{optional substituents on R 1} , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are each independently selected from fluorine, chlorine, bromine, C ₁ -C ₃ alkoxy and C ₆ -C ₈的aryl;

   R ^1, R ^2, R ³ and R ⁴ are each independently selected from hydrogen, fluoro, chloro, bromo, SO ₃ ^-, methyl, ethyl and n-propyl;

   Preferably, in formula (1),

   R ₁ , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are all hydrogen;

   R ^1, R ^2, R ³ and R ⁴ are each independently selected from hydrogen and SO ₃ ^-.
3. The magnolol derivative according to claim 1 or 2, wherein the magnolol derivative having the structure of formula (1) is selected from at least one of the following compounds:

   

   
4. A method for preparing magnolol derivatives, wherein the method comprises: in the presence of a phase transfer catalyst, a compound having the structure of formula (2) is subjected to a contact reaction with bisulfite and/or sulfite,

   

   Wherein, in formula (2), R ₁ , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are each independently selected from hydrogen, halogen, substituted or unsubstituted C ₁ -C ₁₀ alkyl, substituted Or an unsubstituted C ₁ -C ₁₂ alkoxy group, a substituted or unsubstituted C ₆ -C ₁₀ aryl group;

   The _{optional substituents on R 1} , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are each independently selected from halogen, C ₁ -C ₆ alkoxy and C ₆ -C ₁₀ aryl.
5. The method according to claim 4, wherein, in formula (2), R ₁ , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are each independently selected from hydrogen, fluorine, chlorine, bromine, substituted or Unsubstituted C ₁ -C ₅ alkyl group, substituted or unsubstituted C ₁ -C ₆ alkoxy group, substituted or unsubstituted C ₆ -C ₈ aryl group;

   The _{optional substituents on R 1} , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are each independently selected from fluorine, chlorine, bromine, C ₁ -C ₃ alkoxy and C ₆ -C ₈的aryl.
6. The method according to claim 4, wherein the bisulfite and/or sulfite is NaHSO ₃ , KHSO ₃ , Na ₂ SO ₃ , K ₂ SO ₃ , NH ₄ HSO ₃ , (NH ₄ ) ₂ SO ₃ ﹒ At least one of H _{2 O.}
7. The method according to any one of claims 4-6, wherein the molar ratio of the bisulfite and/or sulfite to the compound having the structure of formula (2) is (0.5-4):1, Preferably it is (1-2.5):1.
8. The method according to any one of claims 4-7, wherein the phase transfer catalyst is a quaternary ammonium salt compound, a quaternary phosphonium salt compound or a crown ether compound, preferably a quaternary ammonium salt compound;

   Preferably, the quaternary ammonium salt compound is selected from tetramethyl ammonium chloride, tetramethyl ammonium bromide, tetraethyl ammonium bromide, tetraethyl ammonium chloride, tetrapropyl ammonium bromide, tetrapropyl chloride Ammonium chloride, tetrabutyl ammonium bromide, tetrabutyl ammonium chloride, tetrabutyl ammonium hydrogen sulfate, tetra-n-butyl ammonium sulfate, trioctyl methyl ammonium chloride, trioctyl methyl ammonium bromide, benzyl Benzyl trimethyl ammonium chloride, benzyl trimethyl ammonium bromide, benzyl triethyl ammonium chloride, benzyl triethyl ammonium bromide, dodecyl trimethyl ammonium chloride, dodecyl Trimethyl ammonium bromide, dodecyl trimethyl ammonium bisulfate, tetradecyl trimethyl ammonium chloride, tetradecyl trimethyl ammonium bromide, tetradecyl trimethyl ammonium bisulfate At least one of them.
9. The method according to any one of claims 4-8, wherein the weight ratio of the quaternary ammonium salt compound to the compound having the structure of formula (2) is 0.05-0.5:100, preferably 0.1-0.3:100.
10. The method according to any one of claims 4-9, wherein the conditions of the contact reaction include: a temperature of 40-100°C, preferably 60-80°C; a time of 4-12h, preferably 5-8h .
11. The method according to any one of claims 4-10, wherein the contact reaction is also carried out in the presence of water and an organic solvent, and the organic solvent is selected from the group consisting of methanol, dichloromethane, chloroform, N,N-di At least one of methylformamide and diethyl ether is preferably methanol.
12. The method according to claim 11, wherein the volume ratio of water to the organic solvent is 1: (1-6), preferably 1: (3-5).
13. The method according to any one of claims 4-12, wherein the method further comprises sequentially performing crystallization, filtration, and lyophilization on the product obtained by the contact reaction.
14. Use of the magnolol derivative according to any one of claims 1 to 3 or the magnolol derivative prepared by the method according to any one of claims 4-13 in bacteriostasis.
15. The application according to claim 14, wherein the bacteria are selected from at least one of Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans, and Aspergillus niger.
16. The application according to claim 14 or 15, wherein the bacteria are present in food, medicine or cosmetics, and the amount of the magnolol derivative is 0.001-0.01 per gram of food, medicine or cosmetics. Grams.