甘肃紫花苜蓿黄酮提取条件的响应面法优化及不同生长时间苜蓿黄酮含量的测定

Optimization of Response Surface Method for Extraction Conditions of Flavone from Alfalfa of Gansu Province and Content Determination of Alfalfa Flavone in Different Growth Periods

目的:以甘肃榆中产紫花苜蓿为原料,研究苜蓿黄酮的提取工艺,并对不同采摘时间苜蓿中的黄酮含量进行对比。方法:在单因素试验基础上,根据Box-Behnken design(BBD)试验设计原理,选取乙醇浓度、料液比和提取时间三因素三水平进行响应面试验,建立黄酮提取率的二次回归方程,确定提取工艺的优化组合条件。结果:苜蓿黄酮提取工艺最佳条件为乙醇浓度68%,料液比1∶35(g/mL),提取时间60分钟。该条件下黄酮提取率预测值为1.7707mg/g,验证值为1.7643mg/g。不同采摘期苜蓿以5月10日采摘黄酮含量最高,达4.0490mg/g。结论:甘肃榆中苜蓿不同生长时间黄酮含量存在明显差异,5月中旬采摘黄酮含量最高。

Objective： To study the extraction technology for flavone from alfalfa（medicago sativa.）by taking alfalfa grew in Yuzhong of Gansu Province as the material, and to compare the contents of flavone in alfalfa in different picking times. Methods： Based on single-factor experiment, response surface method was performed from three factors and three levels of the concentrations of alcohol, solid to liquid ratio and extraction time according to design principle of Box-Behnken design（BBD）, quadratic regression equation of extraction rate of flavone was esta-blished to ensure the optimized combination conditions for extraction technology. Results： The optimal conditions for the extraction of flavone from alfalfa were the concentrations of alcohol 68%, solid to liquid ratio 1：35（g/m L） and extraction time 60 minutes. Under the condition, predicted extraction rate of flavone was 1.770 7 mg/g, the verification value was 1.764 3 mg/g. The contents of flavone contained in alfalfa which was picked on May, 10 was the highest and they were 4.049 0 mg/g among the alfalfa at different picking periods. Conclusion： There are notable difference existed in the comprison of the contents of flavone grew in Yuzhong of Gansu Province in different picking times, especially the contents of flavone the highest picked in the midmonth of May.