夹竹桃不同溶剂提取物对福寿螺的毒杀作用评价

Evaluation for toxic effects of different solvent extracts from Nerium indicum leaves on golden apple snail,Pomacea canaliculata

采用浸杀试验法,评价了夹竹桃叶不同溶剂提取物对10日龄福寿螺的毒杀作用。生物活性测定结果表明,夹竹桃鲜叶水提液和干叶水提液对福寿螺均有较高的毒杀作用,其中干叶水提液的杀螺作用更大。用鲜叶水提液和干叶水提液处理12 h,对福寿螺的LC50分别为10.98和1.20 g/L。夹竹桃叶五种有机溶剂(正己烷、甲醇、氯仿、乙酸乙酯、乙醇)提取物对福寿螺均有很高的杀螺活性,其中正己烷提取物的毒杀活性最高,甲醇提取物的毒杀活性最低。以各溶剂提取物200 mg/L处理12 h,死螺率均高于80%。正己烷、氯仿、乙酸乙酯、乙醇和甲醇提取物处理24 h,对福寿螺的LC50分别为32.98,83.62,71.71,75.78和117.07 mg/L。综合考虑各溶剂提取物的杀螺活性、提取效率、有机溶剂价格、毒性等因素,我们认为,乙醇是一种比较理想的提取夹竹桃叶中杀螺活性成分的有机溶剂。

The toxic effect of different solvent extracts from Nerium indicum leaves on golden apple snail （GAS）, Pomacea canaliculata （Lamarck）, was conducted acoording to the snail-immersed method. The bioactivity assay showed that both fresh and dry leaves aqueous extracts had significant molluscicidal effects on GAS, and the latter showed a better effect. The LC50 of fresh and dry leaves aqueous extracts on GAS was 10.98 and 1.20 g/L at 12 h after treatment, respectively. Five organic solvents （chloroform, ethyl acetate, methanol, ethanol,n-hexane） extracts all had higher moUuscicidal activity, among which n-hexane extracts showed the highest activity, and the methanol extracts indicated the lowest activity. When treated with five organic solvent extracts （200 mg/L） for 12 h, the mortalities of GAS were all higher than 80%. Treated with n-hexane, chloroform, ethyl acetate, ethanol, methanol extracts for 24 h, the LC50 were 32.98, 83.62, 71.71, 75.78 and 117.07 mg/L, respectively. Considering mulluscicidal activity of different solvent extracts, extraction efficien- cy, solvents＇ price and toxicity, it was suggested that ethanol was a relatively ideal organic solvent to extract the molluscicidal components from N. ind/cum leaves.