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The main subject of the antibacterial activity of mulberry leaf extract, including inhibition spectrum and the determination of the minimum inhibitory concentration (MIC) to optimize the extraction process of the antibacterial substances, to investigate the stability of the antibacterial substances and further suppression the bacteria active substances were isolated and purified and ingredients rough measurement. Finally, the mulberry leaf extract made some applied research. Mulberry washed with water and 70% ethanol were extracted using a filter paper method and plate count method antibacterial experiments obtained antibacterial spectrum. The linear regression method to quickly and accurately draw the minimum inhibitory concentration (MIC) of E. coli and Staphylococcus aureus. Ethanol extract of Staphylococcus aureus MIC: 0.43% of E. coli MIC: 0.055%; mulberry leaf water extract of Staphylococcus aureus MIC: 0.86%; E. coli MIC: 1.54%. Visible mulberry leaf ethanol extract of the inhibitory effect of two representative bacteria than water extract. The single factor experiment to determine antibacterial substances in mulberry leaf extract optimal conditions: ethanol concentration of 70% (V / V), 70 ° C extraction temperature, extraction time 4h liquid ratio (W / V) 1:30. Orthogonal experiments, optimum conditions for ethanol concentration 70%, extraction temperature 70 ° C, extraction time 6h liquid ratio 1:40. Under this condition, the mulberry leaf extract on Staphylococcus aureus inhibition zone diameter of 8.81mm. The antibacterial activity of mulberry leaf extract stability test results showed that the antimicrobial activity of mulberry leaf extract has good thermal stability, the stability of the UV irradiation. On the inhibition of bacterial cell capacity decreased with pH values ??higher under acidic conditions, including strong antimicrobial activity between pH6-7, the buffer has no effect on the antibacterial activity of the extract and extract antibacterial effect. Further analysis of the active substance, first, the mulberry extract is divided into different polar solvent extracts of petroleum ether portion, dichloromethane, ethyl acetate, n-butanol portion and Mizube by antibacterial activity determined The antimicrobial activity of the ethyl acetate Ministry strongest second n-butanol Ministry. By TLC, the ethyl acetate portion, expand, there is a plurality of spot color with a 1% AlCl3, a plurality of points to display yellow, the ultraviolet light was yellow green and brown. Inferred antibacterial components belong to the flavonoids. Portions of ethyl acetate, polyamide and silica gel column to obtain the best components of the antibacterial effect, TLC, and found that three distinct spots, Rf value, respectively 0.20,0.27,0.72. Sang flavin Rf value of 0.27, and verified by HPLC Sang flavin mulberry bacteriostatic active ingredient. Mulberry leaf extract added to cosmetics for testing, the results show that the mulberry leaf extract has good anti-corrosion, whitening, moisturizing effect, can be widely used in cosmetics.
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