Benzo [g] chromone compound with antibacterial activity as well as preparation method and application of benzo [g] chromone compound

Abstract

The invention belongs to the technical field of food chemistry, and particularly relates to a benzo [g] chromone compound with antibacterial activity as well as a preparation method and application of the benzo [g] chromone compound. The structural formula of the benzo [g] chromone compound with the antibacterial activity is as follows: # imgabs0 #. According to the present invention, the antibacterial activity benzo [g] chromone compound is separated from the medicinal plant Chamaecrista rotundifola (Pers.) Greene, such that the antibacterial activity benzo [g] chromone compound has characteristics of significant antibacterial activity and significant tyrosinase inhibition effect; and the composition also has strong ultraviolet ray absorption capability and can be used as a cosmetic additive.

Description

Technical Field

[0001] The invention belongs to the technical field of plant chemistry, and specifically relates to a benzo[g]chromone compound with antibacterial activity and a preparation method and application thereof. Background Art

[0002] Cassia tomentosa (scientific name: Chamaecrista rotundifolia (Pers.) Greene) is a semi-erect perennial herbaceous plant of the Leguminosae family. Round-leaved Cassia is native to Paraguay, Mexico, Brazil, Argentina and other countries in the United States. Round-leaved Cassia has the advantages of acid resistance, drought resistance, barrenness resistance, high yield, strong nitrogen fixation ability, high nutrient content, and no diseases and insect pests.

[0003] Years of planting have shown that as a perennial herb, Cassia tora is suitable for planting in mountains and slopes, helps prevent soil erosion and water and soil loss, and also plays a significant role in maintaining ecological balance. The crude protein content of Cassia tora is about 20%, and the crude fat, nitrogen, phosphorus, calcium and other contents are also high, while the crude fiber content is low. The yield per mu reaches 1500kg, which is equivalent to the crude protein content of 3000kg corn. It is a good feed crop with high economic value. In addition, Cassia tora also has a wide range of medicinal value, with the effects of clearing away heat and detoxification, diuresis and stranguria, lowering blood lipids, antibacterial, and anti-radiation. At present, there are relatively few studies on the secondary metabolites of Cassia tora. Summary of the invention

[0004] The first purpose of the present invention is to provide a benzo[g]chromone compound with antibacterial activity; the second purpose is to provide a method for preparing the benzo[g]chromone compound with antibacterial activity; and the third purpose is to provide an application of the benzo[g]chromone compound with antibacterial activity.

[0005] The first object of the present invention is achieved by: the benzo[g]chromone compound having antibacterial activity is prepared from the medicinal plant Cassia obtusifolia ( Chamaecrista rotundifolia ) was used as the raw material, and was prepared by pretreatment, extract extraction, MCI decolorization, silica gel column chromatography and high performance liquid chromatography separation. It was named: 6-methoxy-2,9-dimethylbenzo [2,3-g]-4H-chromone, and its English name is: 6-methoxy-2,9-dimethylbenzo [2,3-g]-4H-chromone, with the following structure: .

[0006] The second object of the present invention is achieved by using the medicinal plant Cassia obtusifolia ( Chamaecrista rotundifolia) Prepared from the whole plant through pretreatment, extract preparation, MCI decolorization, silica gel column chromatography, and high-performance liquid chromatography separation, specifically including the following steps: A. Pretreatment: The whole plant of the medicinal plant Chamaecrista rotundifolia is crushed or cut into sections to obtain material a; B. Extract preparation: Add an organic extraction solvent 2 - 6 times the mass of material a to material a, soak and extract at room temperature for 2 - 5 times, with each extraction time being 12 - 20 h, combine the extraction solutions and filter to obtain sample extraction solution b; C. MCI decolorization: Load sample extraction solution b onto an MCI column for decolorization, collect the effluent and concentrate it under reduced pressure to obtain extract c; D. Silica gel column chromatography: 1) Add silica gel with a mesh size of 200 - 250 and a quantity 3 - 10 times the weight of extract c to column for extract c, perform gradient elution with a chloroform - methanol solution with a volume ratio of 20:1 - 1:1, monitor by TLC, and combine the same parts; 2) Concentrate the chloroform - methanol eluate part with a ratio of 9:1 under reduced pressure to obtain component d, add silica gel with a mesh size of 200 - 250 and a quantity 3 - 10 times the weight of the obtained component d to column, perform gradient elution with a chloroform - acetone solution with a volume ratio of 1:0 - 1:2, monitor by TLC, and combine the same parts; E. High-performance liquid chromatography separation: The eluate obtained by eluting with a chloroform - acetone solution with a ratio of 8:2 is separated and purified by high-pressure liquid chromatography to obtain the target antibacterial active benz[g]chromone compound.

[0007] The structure of the prepared antibacterial active benz[g]chromone compound is identified by the following method: Appearance observation shows that the compound is a yellow gum. HRESI-MS shows that its quasi-molecular ion peak is 277.0831 [M+Na] + (calculated value 277.0835), combined with 1 H NMR, 13 C and DEPT spectra to determine its molecular formula as C 16 H 14 NaO3, and the degree of unsaturation is 10.

[0008] The infrared spectrum shows resonance absorption peaks of carbonyl (1665) and aromatic rings (1616, 1570, and 1448 cm -1 )). The maximum absorption of the ultraviolet spectrum at 215, 272, and 364 nm also indicates the possible existence of an aromatic ring structure in the compound.

[0009] The 1 H and 13 C NMR spectra (as shown in Table 1, Figure 1 and Figure 2) It shows that it contains 16 carbons and 14 hydrogens, including a tetrasubstituted naphthalene ring (C-5~C-13, H-5, H-7, H-8 and H-10), and a α,β -unsaturated carbonyl (-O-C=CH-CO-, C-2~C-4, H-3), two methyl groups (C-15, C-16, H3-15 and H3-16), and a methoxy group ( δ C 56.2 and δ H 3.80 s). Further analyzing its NMR data, α,β the -unsaturated carbonyl should be connected to the naphthalene ring to form a pyran ring, forming a b-benzo[g]chromone skeleton to support the presence of 10 unsaturations in the compound, as well as the presence of two oxidized aromatic carbons (C-11 and C-2) in the compound. This speculation can be further confirmed by the HMBC correlations of H-3 and C-2 / C-4 / C-12, H-5 to C-4 / C-6, H-7 to C-13, H-8 and C-14, and H-10 and C-9.

[0010] Table 1. 1 1H NMR and 13 13C NMR data (CDCl3)

[0011] After the parent of the compound is determined, the remaining substituents (methoxy group and two methyl groups) can be regarded as substituents on benzo[g]chromone. The methoxy group is substituted at the C-6 position, which can be confirmed by the HMBC correlation of the methoxy hydrogen ( δ H 3.80 s) and C-6. By the HMBC correlations of H3-15 and C-2 / C-3, H3-16 and C-8 / C-9 / C-14, H-3 and C-15, and H-8 and C-16, it can be determined that the two methyl groups are substituted at the C-2 and C-9 positions. Thus, the structure of the compound of the present invention is determined and named 6-methoxy-2,9-dimethylbenzo[2,3-g]-4H-chromone, and its English name is: 6-methoxy-2,9-dimethylbenzo [2,3-g]-4H-chromone.

[0012] Infrared, ultraviolet and mass spectrometry data of the compound: Ultraviolet spectrum (methanol), λ max (log ε ) 215 (4.42), 272 (4.18), 364 (3.96) nm; Infrared spectrum (KBr tablet): ν max2942, 1665, 1616, 1570, 1448, 1279, 1163, 1038, 960 cm -1 ; 1 H and 13 C NMR data (500 and 125 MHz, (C5D5N), see Table - 1; positive ion mode ESIMS m / z 277 [M+Na] + ; positive ion mode HRESIMS m / z 277.0831 [M+Na] + (calculated value 277.0835, C 16 H 14 NaO3).

[0013] The third object of the present invention is achieved as follows: the application of the antibacterial active benz[g]chromone compounds in the preparation of cosmetic additives.

[0014] Through the research on the chemical constituents of Chamaecrista rotundifolia, an antibacterial active benz[g]chromone compound is isolated. This compound is from natural products, has strong absorption of ultraviolet rays in both UVA and UVB regions, can effectively prevent the skin from turning red and tanned by the sun, has a significant sunscreen effect, and is an ideal sunscreen cosmetic additive.

[0015] The advantages of the present invention are as follows: (1) The compound of the present invention, the benz[g]chromone of the present invention, is isolated from the medicinal plant Chamaecrista rotundifolia Chamaecrista rotundifolia (Pers.) Greene). In order to control soil erosion, Chamaecrista rotundifolia is widely planted artificially in barren wasteland and slopes. It has a large biological yield, the raw material source is very wide, the cost is low, and the separation and preparation are easy to achieve.

[0016] (2) The compound of the present invention has a good effect of inhibiting tyrosinase and also has significant antibacterial activity. When used in cosmetic additives, no additional preservatives need to be added. Moreover, the compound has a significant inhibitory effect on both Gram - positive representative strains and Gram - negative representative strains, and has good antibacterial broad - spectrum property. When added to cosmetics, it can inhibit the growth of bacteria while exerting its efficacy.

[0017] (3) The compound of the present invention is from natural products, safe and non - toxic, has strong absorption of ultraviolet rays in both UVA and UVB regions, can effectively prevent the skin from turning red and tanned by the sun, has a significant sunscreen effect, and is an ideal sunscreen cosmetic additive. Description of the Drawings

[0018] Figure 1The carbon nuclear magnetic resonance spectrum ( 13 C NMR) of the antibacterial active benzogchromone compounds of the present invention; Figure 2 The proton nuclear magnetic resonance spectrum ( 1 H NMR) of the antibacterial active benzogchromone compounds of the present invention; Figure 3 The key HMBC correlation diagram of the antibacterial active benzogchromone compounds of the present invention. Detailed implementation mode

[0019] The present invention will be further described below in conjunction with embodiments and drawings, but the present invention is not limited in any way. Any transformation or replacement based on the teachings of the present invention falls within the protection scope of the present invention.

[0020] The antibacterial active benzogchromone compounds described in the present invention are prepared from the whole plant of the medicinal plant Chamaecrista rotundifolia ( Chamaecrista rotundifolia ), and are prepared by pretreatment, extract extraction, MCI decolorization, silica gel column chromatography and high performance liquid chromatography separation, named: 6-methoxy-2,9-dimethylbenzo[2,3-g]-4H-chromone, and the English name is: 6-methoxy-2,9-dimethylbenzo [2,3-g]-4H-chromone, having the following structure: .

[0021] The preparation method of the antibacterial active benzogchromone compounds described in the present invention is prepared from the whole plant of the medicinal plant Chamaecrista rotundifolia ( Chamaecrista rotundifolia ), and is prepared by pretreatment, extract extraction, MCI decolorization, silica gel column chromatography and high performance liquid chromatography separation. The specific steps are as follows: A. Pretreatment: The whole plant of the raw material medicinal plant Chamaecrista rotundifolia is crushed or cut into sections to obtain material a; B. Extract extraction: Add an organic extraction solvent 2 to 6 times the mass of material a to material a, soak and extract at room temperature for 2 to 5 times, and the extraction time for each time is 12 to 20 hours. Combine the extraction solutions and filter to obtain sample extraction solution b; C. MCI decolorization: Decolorize the sample extraction solution on the MCI column, collect the effluent and concentrate it under reduced pressure to obtain extract c; D. Silica gel column chromatography: 1) Add silica gel with a mesh size of 200 to 250 and 3 to 10 times the weight of extract c to the column, and perform gradient elution with a chloroform-methanol solution with a volume ratio of 20:1 to 1:1. Monitor by TLC and combine the same parts; 2) The chloroform-methanol eluent with a 9:1 ratio was partially concentrated under reduced pressure to obtain fraction d. A column was packed with silica gel of 200-250 mesh at 3-10 times the weight of the obtained fraction d, and gradient elution was performed with a chloroform-acetone solution with a volume ratio of 1:0 to 1:2. After monitoring by TLC, the same parts were combined; E. High-performance liquid chromatography separation: The eluate obtained by eluting with a chloroform-acetone solution with an 8:2 ratio was separated and purified by high-pressure liquid chromatography to obtain the target benzog]chromone compound with antibacterial activity.

[0022] The organic extraction solvent described in step B is an aqueous methanol solution with a mass concentration of 70% - 100%, an aqueous ethanol solution with a mass concentration of 70% - 100%, or an aqueous acetone solution with a mass concentration of 70% - 100%.

[0023] Before loading the column in step D, it also includes a sample mixing step of dissolving with an organic solvent 1.5 - 3 times the weight of material c and adding silica gel of 80 - 100 mesh 0.8 - 2.0 times the weight of material c.

[0024] The organic solvent described is pure methanol or pure acetone.

[0025] The volume ratio of the chloroform-methanol solution described in step D 1) is 20:1, 9:1, 8:2, 7:3, 6:4, and 1:1.

[0026] In step E, the high-performance liquid chromatography separation and purification uses an aqueous methanol solution with a volume concentration of 55 - 62% as the mobile phase, a flow rate of 12 mL / min, a 2.12×250 mm, 5 μm Zorbax PrepHT GF reversed-phase preparative column as the stationary phase, the detection wavelength of the ultraviolet detector is 364 nm, each injection volume is 0.5 - 1.0 mL, the chromatographic peaks at 28 - 35 min are collected, and after multiple accumulations, they are evaporated to dryness to obtain the target antibacterial benzog]chromone compound.

[0027] The application described in the present invention is the application of the antibacterial benzog]chromone compound in the preparation of cosmetic additives.

[0028] The following is a further description of the present invention with specific examples of raw materials of Chamaecrista rotundifolia from different origins in Yunnan: Example 1

[0029] This example provides a preparation method of the antibacterial benzog]chromone compound described in the present invention. The preparation method includes: extract extraction, silica gel column chromatography, and high-performance liquid chromatography separation steps. Using the medicinal plant Chamaecrista rotundifolia as the raw material, the specific operations are as follows: The medicinal plant Chamaecrista rotundifolia used is from Yuanjiang, Yuxi, Yunnan. The raw material is the sample of the whole plant of Chamaecrista rotundifolia after being crushed or cut into sections. It is soaked and extracted 4 times with a 70% methanol aqueous solution by mass concentration for 15 h each time. The combined extraction solution is decolorized on an MCI column, and the eluate is concentrated under reduced pressure to obtain an extract; the extract is dissolved in methanol 2 with a mass twice that of the extract, then silica gel of 90 mesh is added for sample mixing, and a column is packed with silica gel of 220 mesh, and the sample is loaded onto the column after mixing; gradient elution is carried out with chloroform-methanol eluents with volume ratios of 20:1, 9:1, 8:2, 7:3, 6:4, and 1:1 respectively. The gradient elution solution is collected, concentrated, monitored by TLC, and the same parts are combined to obtain 6 parts A-F. Among them, for the collected sample B (9:1) part of 208 g, a column is packed with silica gel of 220 mesh with 8 times the amount of the extract, and gradient elution is carried out with chloroform-acetone eluents with volume ratios of 1:0, 4:1, 1:1, and 1:2 respectively. The gradient elution solution is collected, concentrated, monitored by TLC, and the same parts are combined to obtain 3 parts. Among them, the 4:1 part is 204 g. Then, with 58% methanol as the mobile phase, the flow rate is 12 ml / min, a Zorbax PrepHT GF reversed-phase preparative column of 2.12×250 mm, 5 µm is used as the stationary phase, the detection wavelength of the ultraviolet detector is 364 nm, 0.8 mL is injected each time, the chromatographic peak at 30.4 min is collected, and after multiple accumulations, it is evaporated to dryness to obtain the antibacterial active benz[g]chromone compound of the present invention. The compound structure is identified by the following method.

[0030] Appearance observation shows that the compound is a yellow gum. HRESI-MS shows that its quasi-molecular ion peak is 277.0831 [M+Na] + (calculated value 277.0835), combined with 1 H NMR, 13 C and DEPT spectra to determine its molecular formula as C 16 H 14 NaO3, and the degree of unsaturation is 10.

[0031] The infrared spectrum shows resonance absorption peaks of carbonyl (1665) and aromatic rings (1616, 1570, and 1448 cm -1 ). The maximum absorption of the ultraviolet spectrum at 215, 272, and 364 nm also indicates that there may be an aromatic ring structure in the compound.

[0032] The 1 H and 13 C NMR spectra (as shown in Table 1, Figure 1 and Figure 2 ) show that it contains 16 carbons and 14 hydrogens, including a tetrasubstituted naphthalene ring (C-5~C-13, H-5, H-7, H-8, and H-10), and a α,β-unsaturated carbonyl (-O-C=CH-CO-, C-2~C-4, H-3), two methyl groups (C-15, C-16, H3-15 and H3-16), and a methoxy group ( δ C 56.2 and δ H 3.80 s). Further analyzing its NMR data, α,β the -unsaturated carbonyl should be connected to the naphthalene ring to form a pyran ring, forming a b-benzo[g]chromone skeleton to support the presence of 10 degrees of unsaturation in the compound and the presence of two oxidized aromatic carbons (C-11 and C-2) in the compound. This speculation can be further confirmed by the HMBC correlations of H-3 and C-2 / C-4 / C-12, H-5 and C-4 / C-6, H-7 and C-13, H-8 and C-14, and H-10 and C-9.

[0033] After the parent body of the compound is determined, the remaining substituents (methoxy group and two methyl groups) can be regarded as the substituents on benzo[g]chromone. The methoxy group is substituted at the C-6 position, which can be confirmed by the HMBC correlation of methoxy hydrogen ( δ H 3.80 s) and C-6. The substitution positions of the two methyl groups at C-2 and C-9 can be determined by the HMBC correlations of H3-15 and C-2 / C-3, H3-16 and C-8 / C-9 / C-14, H-3 and C-15, and H-8 and C-16. So far, the structure of the compound of the present invention is determined and named 6-methoxy-2,9-dimethylbenzo[2,3-g]-4H-chromone, and its English name is: 6-methoxy-2,9-dimethylbenzo[2,3-g]-4H-chromone.

[0034] Example 2

[0035] This example provides a preparation method of the antibacterial active benzo[g]chromone compounds of the present invention. The preparation method includes: extract extraction, silica gel column chromatography and high performance liquid chromatography separation steps. Using the medicinal plant Cassia rotundifolia as the raw material, the specific operations are as follows: The medicinal plant Chamaecrista rotundifolia used is produced in Hekou, Honghe, Yunnan. The raw material is a sample obtained by crushing or cutting the whole plant of Chamaecrista rotundifolia. It is soaked and extracted 5 times with an ethanol aqueous solution with a mass concentration of 80% for 12 hours each time. The combined extraction solution is decolorized on an MCI column, and the eluate is concentrated under reduced pressure to obtain an extract; the extract is dissolved in acetone with a volume 3 times that of the extract, then 100-mesh silica gel is added for sample mixing, and a column is packed with 250-mesh silica gel. After sample mixing, it is loaded onto the column; gradient elution is carried out with chloroform-methanol eluents with volume ratios of 20:1, 9:1, 8:2, 7:3, 6:4, and 1:1 respectively. The gradient eluate is collected, concentrated, monitored by TLC, and the same parts are combined to obtain 6 parts A - F. Among them, for the collected sample B (9:1) part of 244 g, a column is packed with 250-mesh silica gel with a volume 10 times that of the extract, and gradient elution is carried out with chloroform-acetone eluents with volume ratios of 1:0 to 1:2 respectively. The gradient eluate is collected, concentrated, monitored by TLC, and the same parts are combined to obtain 3 parts. Among them, the 8:2 part is 201 g. Then, using 60% methanol as the mobile phase, with a flow rate of 12 ml / min, a Zorbax PrepHT GF reversed-phase preparative column with dimensions of 2.12×250 mm and 5 µm as the stationary phase, and a detection wavelength of 364 nm for the ultraviolet detector, 0.5 - 1.0 mL is injected each time, and the chromatographic peak at 33.6 min is collected. After multiple accumulations, it is evaporated to dryness to obtain the antibacterial active benz[g]chromone compound of the present invention. After identification, the identification method is the same as that in Example 1, and the result shows that the molecular formula is C 16 H 14 O3.

[0036] Example 3

[0037] This example provides a preparation method for the antibacterial active benz[g]chromone compound of the present invention. The preparation method includes steps of extract extraction, silica gel column chromatography, and high performance liquid chromatography separation. Using the medicinal plant Chamaecrista rotundifolia as the raw material, the specific operations are as follows: The medicinal plant Chamaecrista rotundifolia used is produced in Menghai, Xishuangbanna, Yunnan. The raw material is the sample of the whole plant of Chamaecrista rotundifolia after being crushed or cut into sections, and it is soaked and extracted twice with an acetone aqueous solution with a mass concentration of 80%, 12 hours each time. The combined extraction solution is decolorized on an MCI column, and the eluate is concentrated under reduced pressure to obtain an extract; the extract is dissolved in methanol at 1.5 times the mass of the extract, then silica gel of 80 mesh is added for sample mixing, and a column is packed with silica gel of 200 mesh, and the sample is loaded onto the column after mixing; gradient elution is carried out with chloroform-methanol eluents with volume ratios of 20:1, 9:1, 8:2, 7:3, 6:4 and 1:1 respectively. The gradient eluate is collected, concentrated, monitored by TLC, and the same parts are combined to obtain 6 parts A - F. Among them, for the collected sample B (9:1) part of 206 g, a column is packed with silica gel of 200 mesh at 3 times the amount of the extract, and gradient elution is carried out with chloroform-acetone eluents with volume ratios of 1:0, 8:2, 1:1, 1:2 respectively. The gradient eluate is collected, concentrated, monitored by TLC, and the same parts are combined to obtain 3 parts. Among them, the 8:2 part is 183 g. Then, with 62% methanol as the mobile phase, a flow rate of 12 ml / min, a Zorbax PrepHT GF reversed-phase preparative column of 2.12×250 mm, 5 µm as the stationary phase, and a detection wavelength of 364 nm for the ultraviolet detector, 0.5 - 1.0 mL is injected each time, and the chromatographic peak at 34.9 min is collected. After multiple accumulations and evaporation to dryness, the antibacterial active benz[g]chromone compound of the present invention is obtained. After identification, the identification method is the same as that in Example 1, and the result shows that the molecular formula is C 16 H 14 O3.

[0038] Example 4

[0039] The antibacterial active benz[g]chromone compound prepared in Example 1 was used for tests: A. Antibacterial activity test of the compound: The antibacterial activity of the compound was determined by the microdilution method according to the recommendations of the Clinical and Laboratory Standards Institute (CLSI). Representative Gram-positive strains (Staphylococcus aureus (Staphylococcus), Streptococcus pyogenes (Streptococcus), Streptococcus pneumoniae (Streptococcus)) and representative Gram-negative strains (Escherichia coli (Escherichia), Enterobacter enteritidis (Salmonella), Pseudomonas aeruginosa (Pseudomonas)) were selected for testing. The results showed that the IC 50 values (μg / mL) of the compound of the present invention for the representative strains were: Staphylococcus aureus 3.88, Streptococcus pyogenes 8.06, Streptococcus pneumoniae 4.95, Escherichia coli (Escherichia) 3.22, Enterobacter enteritidis 4.90, Pseudomonas aeruginosa 6.18. The compound has significant antibacterial activity and broad antibacterial spectrum.

[0040] B. Tyrosinase Inhibitory Activity Test of Compounds: Since tyrosinase is a key enzyme involved in the synthesis of skin melanin, whitening effects can be achieved by regulating its activity. The tyrosinase inhibitory activity of the benz[g]chromone compounds was further tested. The specific test was carried out with reference to "Cosmetics - Test Method for Inhibiting Tyrosinase Activity (T / ZHCA 001-2018)". The results showed that when the concentration of the benz[g]chromone was 50 μg / mL, the inhibition rate of tyrosinase reached 58.6%, indicating significant tyrosinase inhibitory activity.

[0041] C. Determination of Sunscreen Performance of Compounds: Due to the large conjugated system of benz[g]chromone compounds, they have strong absorption of ultraviolet light. Therefore, the sunscreen performance of the compounds was determined. The test was carried out with reference to "Qualitative Determination of Ultraviolet Absorbents in Cosmetics - Ultraviolet Spectrophotometry (QB / T 2334-1997)". The test results showed that the benz[g]chromone had strong ultraviolet absorption in both the UVB region of 280 - 320 nm and the UVA region of 320 - 400 nm, and the molar absorption coefficient was greater than 3.2×10 3 . Since ultraviolet rays in the UVA and UVB regions can cause the skin to turn red, tan, and even cause skin damage in severe cases. The strong ultraviolet absorption of the benz g chromone in this wavelength range confirmed that the compound had significant sunscreen effects.

[0042] D. Application effects of the compound whitening skincare cream: Referring to the formulation design concept of the whitening skincare cream, the basic formulation of the skincare cream selects olive oil, medical petrolatum, paraffin oil, cetyl alcohol, stearyl alcohol, etc. as the oil phase; deionized water (distilled water), cyclodextrin, propylene glycol, tartaric acid, citric acid, etc. as the water phase, thickened with sodium carboxymethyl cellulose and polyvinyl alcohol; then use glyceryl monostearate, sodium stearate, lanolin and SE emulsifier to adjust the hydrophilic-lipophilic balance value and water content; add physical auxiliaries (titanium dioxide, pearl powder, calcium carbonate), moisturizers (allantoin, glycerin), antioxidants (fish liver oil, VC, VE), and natural essential oils (rose essential oil, lavender essential oil, jasmine essential oil, etc.) for fragrance. The benz[g]chromone extract described in the present invention is used as an antibacterial, whitening, and UV protection additive. The specific formulation ratio (mass percentage %) is: select 2.0% of olive oil, 12.0% of medical petrolatum, 4.0% of paraffin oil, 1.0% of cetyl alcohol (cetyl alcohol), 0.8% of stearyl alcohol; 2.0% of cyclodextrin, 5.0% of propylene glycol, 0.1% of tartaric acid, 0.1% of citric acid, 0.2% of polyvinyl alcohol; 2.0% of glyceryl monostearate, 0.8% of sodium stearate, 1.2% of lanolin, 1.2% of SE emulsifier, 0.2% of titanium dioxide, 2.0%, 0.05% of vitamin-E, natural essential oils (0.1 - 0.3%, flexibly adjusted according to the required fragrance type), 0.2% of the benz[g]chromone described in the present invention, and the balance is water. The prepared whitening skincare cream was entrusted to a professional testing institution for testing, using the brown guinea pig skin test method. The results show that the inhibition rates of melanocytes and melanocyte-containing cells are both above 46.5%. The same formulation skincare cream without the benz[g]chromone compound was used as a control, and the inhibition rates of the control on melanocytes and melanocyte-containing cells are both above 45.6%.

[0043] Example 5

[0044] The antibacterial active benz[g]chromone compounds prepared in Example 2 and Example 3 were respectively used for tests. The method was the same as that in Example 4. The results show that the antibacterial active benz[g]chromone compounds described in the present invention have significant antibacterial activity, antibacterial broad-spectrum property, tyrosinase inhibition activity, sunscreen effect and whitening effect.

Claims

1. A benzog]chromone compound with antibacterial activity, characterized in that, The described benzogchromone compound with antibacterial activity is prepared from the whole plant of the medicinal plant Chamaecrista rotundifolia through pretreatment, extract preparation, MCI decolorization, silica gel column chromatography and high performance liquid chromatography separation, named as: 6-methoxy-2,9-dimethylbenzo[2,3-g]-4H-chromone, and its English name is: 6-methoxy-2,9-dimethylbenzo [2,3-g]-4H-chromone, with the following structure: 。 2. A method for preparing the benzog]chromone compound with antibacterial activity according to claim 1, characterized in that, It is prepared from the whole plant of the medicinal plant Chamaecrista rotundifolia through pretreatment, organic solvent extraction, MCI decolorization, silica gel column chromatography and high performance liquid chromatography separation, specifically including the following steps: A. Pretreatment: The whole plant of the raw medicinal plant Chamaecrista rotundifolia is crushed or cut into sections to obtain material a; B. Organic solvent extraction: Add an organic extraction solvent 2 to 6 times the mass of material a to material a, soak and extract at room temperature for 2 to 5 times, with each extraction time being 12 to 20 h, combine the extraction liquids and filter to obtain sample extraction liquid b; C. MCI decolorization: Decolorize the sample extraction liquid on an MCI column, collect the effluent and concentrate it under reduced pressure to obtain extract c; D. Silica gel column chromatography: 1) Add silica gel with a mesh size of 200 to 250 and a weight 3 to 10 times that of extract c to column the extract c, and perform gradient elution with a chloroform-methanol solution with a volume ratio of 20:1 to 1:

1. Monitor by TLC and combine the same parts; 2) Concentrate the chloroform-methanol eluent part with a ratio of 9:1 under reduced pressure to obtain component d. Add silica gel with a mesh size of 200 to 250 and a weight 3 to 10 times that of the obtained component d to column it, and perform gradient elution with a chloroform-acetone solution with a volume ratio of 1:0 to 1:

2. Monitor by TLC and combine the same parts; E. High performance liquid chromatography separation: The eluent obtained by eluting with a chloroform-acetone solution with a ratio of 8:2 is separated and purified by high pressure liquid chromatography to obtain the target benzogchromone compound with antibacterial activity.

3. The preparation method according to claim 2, wherein The organic extraction solvent described in step B is an aqueous methanol solution with a mass concentration of 70% to 100%, an aqueous ethanol solution with a mass concentration of 70% to 100%, or an aqueous acetone solution with a mass concentration of 70% to 100%.

4. The preparation method according to claim 2, characterized in that, Before column loading in step D, it also includes a sample mixing step of dissolving with an organic solvent 1.5 to 3 times the weight of material c and adding silica gel with a mesh size of 80 to 100 and a weight 0.8 to 2.0 times that of material c.

5. The preparation method according to claim 2, wherein, The organic extraction solvent is pure methanol or pure acetone.

6. The preparation method according to claim 2, wherein The volume ratio of the chloroform-methanol solution described in step D1) is 20:1, 9:1, 8:2, 7:3, 6:4 and 1:

1.

7. The preparation method according to claim 2, characterized in that, In step E, the high performance liquid chromatography separation and purification uses an aqueous methanol solution with a volume concentration of 55 - 62% as the mobile phase, with a flow rate of 12 mL / min, a 2.12×250 mm, 5 μm ZorbaxPrepHT GF reverse phase preparation column as the stationary phase, the detection wavelength of the ultraviolet detector is 364 nm, each injection volume is 0.5 to 1.0 mL, collect the chromatographic peaks at 28 to 35 min, and after multiple accumulations, evaporate to dryness to obtain the target antibacterial benzogchromone compound.

8. Use of the benzog]chromone compound with antibacterial activity according to claim 1, characterized in that, Use of the described antibacterial active benzog]chromone compounds in the preparation of cosmetic additives.

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