Abstract: To optimize the process of extracting and separating flavonoids from alfalfa, different methods were adopted to extract and separate the flavonoids systematically. Results showed that 30% ethanol solution and water (pH=7.5) had the best effect on alfalfa flavonoids extraction. Leaching efficiency of the flavonoids were 0.46% and 0.49%, respectively. The highest content of alfalfa flavonoids extracted with water was 1.61% when pH was 9.0. The optimum pH was 2.2 for separation of alfalfa flavonoids and the content of flavonoids in the extractive was 9.80%. Different macroporous resins were used to separate alfalfa flavonoids extracted with ethanol solution. DS-17 showed the best separation effect and the content of flavonoids was 5.87%. The effect of macroporous resins on the separation of alfalfa flavonoids extracted by acid-isolation was analyzed. DM130 had the best effect and the highest contents of alfalfa flavonoids in two treatments were 24.25% and 29.35%, respectively.

Key words: Alfalfa, Flavonoids, Extraction, Purify

摘要： 为探讨紫花苜蓿(Medicago sative L.)黄酮的提取与纯化工艺,采用不同乙醇浓度和不同pH进行提取,然后用不同来源和型号的大孔树脂进行纯化,以得出苜蓿黄酮的最佳提取和纯化方法。结果表明:30%乙醇、水浸提(pH为7.5)对紫花苜蓿黄酮的浸出率最高,分别为0.46%和0.49%,pH在9.0时所得提取物黄酮含量最高为1.61%;pH为2.2～2.4时,对紫花苜蓿黄酮有最好的沉淀效果,所得沉淀物中黄酮含量为9.80%;9种型号的大孔树脂中DS-17对乙醇提取物中紫花苜蓿黄酮有较好的分离效果,所得提取物黄酮为5.87%;在大孔树脂对碱溶酸沉提取物中黄酮的分离中,2组试验均以DM130的效果最好,所得分离物黄酮含量最高分别为24.25%和29.35%。

关键词: 紫花苜蓿, 黄酮类化合物, 提取, 纯化