不同提取剂对春花胡枝子黄酮含量及抑菌活性影响的研究

Effect of different extracting reagents on content and inhibition activity against bacteria of Lespedeza dunnii flavonoid

目的:研究不同溶剂提取对春花胡枝子黄酮含量及其体外抑菌活性的影响。方法:分别用水、乙醇、甲醇做提取剂,可得粗黄酮粉,将粗黄酮经大孔树脂纯化得精制黄酮。采用盏碟法及平板计数法测定4种黄酮粉抑菌活性。结果:以甲醇、乙醇、水作溶剂可从春花胡枝子叶粉中提取到黄酮含量不同的粗黄酮粉,经大孔树脂纯化后可得到含黄酮74.8%的精制黄酮粉。4种黄酮粉对6种受试菌均有抑制作用,但存在很大差异。相同条件下,春花胡枝子黄酮粉对酵母菌、小麦赤霉菌、苹果炭疽菌的抑制作用大于对金黄色葡萄球菌、大肠杆菌及枯草芽孢杆菌的抑制作用。pH值对春花胡枝子黄酮粉的抑菌活性有较大的影响,超过或低于最佳pH值范围时,抑菌活性急剧下降。结论:不同溶剂提取的春花胡枝子黄酮粉黄酮含量及体外抑菌活性不同。

Objective：To study the effect of different extracting reagents on the content and iInhibition activity against bacteria of Lespedeza dunnii flavonoid. Methods： Crude flavonoid powder was gained using water, ethanol and methanol as extracting reagent respectively and to obtain the refined flavonoid powder from the crude flavonoid powder purified by AB - 8 macroporous resin. The inhihibition effect of the four kinds of flavonoid powder against bacteria was determined adopting plate count method. Results：The crude flavonoid powder in which the content of flavonoid was different could be gained from the leaves of L. dunnii by using methanol,elthanol and water as extracting reagent. The refined flavonoid powder in which the content of pure flavonoid reached 74. 8% was obtained after being purified by AB - 8 macroporous resin. All of the four kinds of flavonoid powders had some inhibition function against the six bacteria but there were great differences as the concentration of flavonoid powder and the category of bacteria changed. The abilities of L dunnii flavonoid inhibiting yeast, fusarium graminearum and colletotrichum gloeosporioides were much greater than those of staphyloccus, colibacillus and bacillus subtilis. The pH value had great effect and the inhibition activity of L dunnii flavonoid against bacteria declined sharply when the pH was above or under the optimistic pH range. Conclusion：The inhibition ablities against bacteria and the content of the crude flavonoid powder extracted by different reagent are different.