Extraction, Separation And Analysis Of Antibacterial Component From Mulberry Leaves

In this paper, Mulberry leaves was used as raw material to study the extraction and separation of its effective antibacterial ingredint and to identify the elements of the separation production. There are three sections in this paper, one is the research of the extraction process, second section is the enrichment of the effective antibacterial ingredient and to evaluate the effection of the antibacterial activity, the last parts is the separation and analysis of the effective component.In the extraction part, extraction rate, antibacterial effect to S.aureus and E.coli, the content of total flavonoids were used to determine the extraction methods. Finally, the best method is ethanol extraction. On this basis, the single-factor experiment and the orthogonal experiment were researched, determined the best extraction temperature is 70℃, concentration of ethanol is 70 %, extraction time is 4 h, extraction solid/liquid is1: 30.To use four kinds of solvents to extract the ethanol extraction and got the petroleum ether part, the dichloromethane part, the ethyl acetate part and the 1-butanol part, used the paper disc method , the MIC method and the content of total flavonoids to compare the inhibition effect of the four extraction parts, the best effective part is ethyl acetate part, the second is the dichloromethane part, the third is the petroleum ether part, the last one is the 1-butanol part. And the MIC to S.aureus of the best extraction is 0.625 mg/mL,the MIC to E.coli is 1.25 mg/mL, the total flavonoids is 72.44 mg/g.To discuss the antibacterial spectrum of the ethyl acetate part, the best antibacterial active effect is Salmonella, the second is Sa., the third is Ec., the fourth is Yeast, and it has hardly effect to Aspergillus niger and Bacillus subilis. The ethyl acetate part has good thermal stability, pH stability, UV stability. To research the antibacterial effect of the ethyl acetate part in washing fluid and nutrition cream, when the quality is 1.0 % in washing fluid and 1.2 % in nutrition cream, the colony of bacteria is 0 in 30 weeks. After hydrolyzed of ethanol extraction, HPLC was used to determine the content of Quercetin and Keampferol is 0.5162 mg/g and 0.2463 mg/g. Analyzed component of the ethyl acetate part with reagents reaction and TLC method, determined the antibacterial activity ingredient is flavonoids. To separate the ethyl acetate part with polyamide column chromatography, five kinds of concentration of ethanol was used to elute, determined the best antibacterial effect elution part is 95 % ethanol elution section, repeated it and collected the 95 % ethanol elution part, determined the total flavonoids is 3.6 times of the ethyl acetate part's. Used Silica gel column chromatography to separate it, analyzed with TLC and collected the same parts. Finally got seven parts, determined the best antibacterial elution part is IV section.Analyzed the IV section with HPLC, UV and LC-MS, foud the best antibacterial part contain Morin, little Rutin and Kaempferol...