鼠曲草提取液黄酮类化合物抗菌及抗氧化性能

Antibactrial and antioxidative activity of the fl avonoids extracted from Gnaphlium affi ne D.Don

采用乙醇回流法提取鼠曲草中的黄酮类化合物，通过采用琼脂扩散法测定提取液对4种细菌的抗茵性能和采用清除超氧根离子、羟自由基、DPPH自由基检测提取液的体外抗氧化活性。结果表明：鼠曲草提取液（总黄酮含量在4．5-18mg／mL）对大肠杆菌、金黄色葡萄球茵、枯草芽孢杆菌都有较好的抑制作用，并随着提取液中总黄酮含量的升高，抑制作用增强，但对普通变形杆菌无抑制作用；在抗氧化实验中，提取液对超氧根离子、羟自由基、DPPH自由基都有一定的清除能力，随着提取液中黄酮浓度的升高，其清除活性逐渐增强，对超氧根离子和羟自由基清除能力低于对照（抗坏血酸），而鼠曲草提取液对DPPH自由基清除活性很强，在总黄酮含量为2mg／mL时清除率达到98．78％，其活性高于阳性对照（芦丁）。总之，鼠曲草提取液具有一定的抑茵和抗氧化能力。

In this study, flavonoids were extracted from Gnaphlium affine D.Don by the ethanol refluxing method. The antimicrobial activities of the flavonoids against four bacteria were surveyed through agar diffusion method, and the antioxidative abilities of the flavonoids of Gnaphlium affine D.Don were also evaluated using superoxide anions, hydroxyl radicals and DPPH radicals scavenging activities. Results showed that the extraction （the concentration of flavonoids increased from 4.5 mg/mL to 18 mg/mL） from Gnaphlium affine D.Don had strong antibacterial activities against Escherichia coli, Bacillus subtilis and Staphylococcus aureus, while it had no antibactrial effect against Proteusbacillus vulgaris. The extraction from Gnaphlium affine D.Don had an effective superoxide anion radical scavenging, hydroxyl radicals scavenging and DPPH free radicals scavenging, furthermore, the scavenging activities were enhanced with the concentration of total flavonoids in extraction increasing, the superoxide anions, hydroxyl radicals scavenging activities of the extraction were inferior to those of the control （Vc）, however, DPPH radicals scavenging activities of the extraction were superior to those of the control （Rutin）, at the concentration of 2 mg/mL flavonoids in the extraction showed 98.78% DPPH radicals scavenging rates. In conclusion, the flavonoids in extraction from Gnaphlium affine D.Don had certain antibacterial and antioxidant activities.