荷花不同部位总黄酮分布及荷叶黄酮提取工艺研究

Total Flavonoid Distribution in the Different Parts of Lotus and Study on the Extraction Technology of Flavonoid in Lotus Leaf

目的测定荷花不同部位总黄酮含量分布并探讨荷叶黄酮最佳提取工艺条件。方法采用索氏提取法对荷花五个不同部位(花瓣、荷叶、叶梗、莲蓬壳、雄蕊)的总黄酮进行提取,利用硝酸铝显色法测定提取总黄酮含量;采用超声波辅助回流法提取荷叶黄酮并通过正交实验设计进行工艺条件优化。结果荷花不同部位总黄酮含量分布:莲蓬壳>荷叶>雄蕊>花瓣>叶梗;超声波辅助回流法提取荷叶黄酮时用30倍量60%乙醇,70℃超声回流提取90min,其中超声时间为20min为佳。结论荷花不同部位总黄酮含量有一定差异;在超声波辅助回流法提取荷叶黄酮实验处理下,不同提取工艺条件对荷叶黄酮提取效果产生一定的影响。

OBJECTIVE To determine the total flavonoid distribution in the different parts of lotus and explore on the best extraction technology of flavonoid in lotus leaf. METHODS The total flavonoids of lotus petal, lotus leaf, lotus stalk, lotus receptaculu mloti and lotus stamen were extracted by Soxhlet＇s apparatus method, the NaNO2-Al （NO3 ）3-NaOH solution was adopted as development system and rutin as the standard sample, and the total flavonoids from the five parts of lotus were then determined through ultraviolet speetrophotometer and their distribution was calculated. The ultrasonic-assistant reflux extraction method was also used to extract the flavonoids of lotus leaf, and the optimum extraction condition was explored using orthogonal design. RESULTS The total flavonoid distribution in the different parts of lotus is as follows ： lotus receptaculu mloti 〉 lotus leaf 〉 lotus stamen 〉 lotus petal 〉 lotus stalk. The extraction technology of flavonoid in lotus leaf by using uhrasonic-assistant reflux extraction method was got to the optimum condition ： 30 fold of 60% alcohol solution proportion to the lotus leaf materials, ultrasonic-assistant reflux extraction 90 min under the temperature 70℃ ,and uhrasonic time 20 min. CONCLUSION The content of total flavonoid varies in the different parts of lotus; the extraction efficiency of flavonoid of lotus leaf has been influenced to some extent under different experimental condition using uhrasonic-assistant reflux extraction.