桑枝中槲皮素和绿原酸的薄层色谱鉴别及抗氧化活性筛选

目的：建立桑枝中槲皮素和绿原酸的薄层色谱（TLC）鉴别方法，并筛选其抗氧化活性。方法采用甲醇为溶剂，超声提取桑枝中的槲皮素和绿原酸，实验了用不同展开系统、显色剂、温度、检视方法及不同薄层板对桑枝中槲皮素及绿原酸薄层鉴别的影响，选择最佳薄层鉴别条件。以1，1-二苯基-2-苦肼基自由基（DPPH）显色，筛选其抗氧化活性。结果以乙酸乙酯∶水∶甲酸∶甲苯（17∶2∶2∶0.8）为展开剂在硅胶G板上展开，1%AlCl3为显色剂，366 nm下检视，桑枝中的槲皮素和绿原酸出现明显蓝色及蓝绿色斑点，薄层-生物自显影实验发现槲皮素和绿原酸的薄层板在紫色背景下呈现淡黄色斑点，证明二者具有抗氧化活性。结论本法操作简便，结果准确可靠，可用于桑枝的质量控制。

TLC identification of quercetin and chlorogenic acid in Ramulus mori and their antioxidant activity screening

Objective To establish a thin-layer chrometograrrgy(TLC)method for the identification of quercetin and chloro?genic acid in Ramulus mori,and to screen their antioxidant activity. Methods The quercetin and chlorogenic acid were extracted by ultrasonic method with methanol as a solvent. The effect of different developed system,reagent,temperature,view methods and differ?ent silica gel plate on the TLC of quercetin and chlorogenic acid in Ramulus mori were tested to select the best TLC conditions. The antioxidant activity of quercetin and chlorogenic acid was screened with DPPH as a reagent. Results The ethyl acetate∶water∶formic acid∶toluene(17∶2∶2∶0.8)was used as a developing system and 1%AlCl3 as a chromogenic reagent. Quercetin and chlorogenic acid in Ramulus mori were identified under 366 nm,with blue and blue-green spots on silica gel G plate,and yellowish spots under purple background by the test of TLC-bioautography. Both were proven to have antioxidant activity. Conclusion The method is simple,accu?rate and reliable,and can be used for quality control of Ramulus mori.