银杏叶黄酮对大肠杆菌生物膜的抑制作用

以乙醇为提取溶剂从银杏叶中提取总黄酮，使用DA201大孔树脂对其进行纯化；测定了银杏叶黄酮对大肠杆菌的最小抑菌浓度（MIC），并考察了对大肠杆菌生物膜形成和黏附性的影响，使用3，5-二硝基水杨酸法（DNS法）测定了银杏叶黄酮对胞外多糖含量的影响。结果表明，银杏叶黄酮对大肠杆菌的MIC为4 mg/mL；银杏叶黄酮对大肠杆菌生物膜的形成和黏附有抑制作用，其质量浓度为1倍MIC时，生物膜形成抑制率为59.09%，黏附性抑制率为28.99%；其质量浓度在1倍MIC以上时，对大肠杆菌生物膜多糖的形成有明显的抑制作用。

Inhibitory effect of flavonoids from Ginkgo biloba leaves on Escherichia coli biofilms

The total flavonoids were extracted from Ginkgo biloba leaves with ethanol as extraction solvent and purified using DA201 macroporous resin. The minimum inhibitory concentration (MIC) of the flavonoids against Escherichia coli was determined. The effect of the flavonoids on the formation and adhesion of E. coli biofilms was also investigated. The effect of the flavonoids on the content of extracellular polysaccharides was determined by the 3,5-dinitrosalicylic acid (DNS) method. The results showed that the MIC of the flavonoids against E. coli was 4 mg/mL. The flavonoids can inhibit the formation and adhesion of E. coli biofilms. When the mass concentration of the flavonoids was the MIC, the biofilm formation inhibition rate was 59.09%, and the adhesion inhibition rate was 28.99%. When the mass concentration of the flavonoids was greater than the MIC, the formation of E. coli biofilm polysaccharides was significantly inhibited.