不同分离方法对黄杜鹃叶提取物灭蚜活性的影响

黄杜鹃(Rhododendron molle)叶提取物对桔二叉蚜(Toxoptera aurantii)有较强的毒杀作用。用水提醇沉法和醇提水沉法获得的提取物对蚜虫的致死中浓度(LC₅₀)分别为4 030 mg／L和5 791 mg／L。水提醇沉提取物的乙酸乙酯萃取物对桔二叉蚜的毒力较其他萃取物强,其LC50为1 949 mg／L,表明黄杜鹃叶含有的杀虫活性物质主要存在于乙酸乙酯萃取物中。对水提醇沉提取物进行硅藻土柱层析分离,得到的第3组分得率和灭蚜效果均优于氧化铝柱层析分离到的第3组分。

Aphid-killing activity of the extracts from the leaves of Rhododendron molle using different separation methods

Aphid-killing activity of the extracts from the leaves of Rhododendron molle using different separation methods was studied. The results showed that the median lethal concentrations (LC50) of the water extraction and ethanol precipitate (WEP) and the ethanol extraction and water precipitate (EWP) to Toxoptera aurantii were 4 030 mg/L and 5 791 mg/L. Ethyl acetate extracts from the WEP extracts were more toxic to Toxoptera aurantii, the LC50 of which was 1 949 mg/L. The harvest rate and aphid-killing activity of the third fraction from WEP by diatomite column chromato graphy were better than those of the third fraction by alumina column chromatography.