Abstract:

Objective To investigate the molluscicidal effects of extracts from five Eucalyptus leaves collected from Guang?
dong Province，China. Methods According to the WHO recommended indoor immersed method，the molluscicidal effects of ex?
tracts from five Eucalyptus leaves with 250，100，10 mg/L of water extraction，alcohol precipitation and organic solvent extraction
were investigated. Results The dose?effect relationship showed that all the mortality rates of Oncomelania hupensis reached 80%
with the volatile oil from five Eucalyptus leaves immersed at the concentrations of 100 mg/L for 48 h，and the mortality rates were
both 93.3% with the volatile oil from Corymbia citriodora and Eucalyptus urophylla leaves. The mortality rate was up to 95% with
the chloroform extract，and the mortality rate reached 60% at the concentrations of 10 mg/L for 48 h. Conclusion The volatile
oils from five Eucalyptus leaves and the chloroform extract in alcohol extraction from Eucalyptus urophylla leaves are better than
other solvents.

Key words: Oncomelania hupensis；Mounsicicidal effect；Eucalyptus leaves；Extract；Screening

摘要：

目的观察广东5种桉树叶提取物的杀灭钉螺效果。方法采用有机溶剂萃取法和水提醇沉法分别得到5种桉树叶的挥发油、水溶性挥发成分、醇提流浸膏和醇沉物样品，设置不同浓度处理液，以去氯水作为对照组，按WHO推荐的室内浸杀法进行杀螺药效试验，观察比较钉螺死亡率。结果5种桉树叶挥发油在浓度为100 mg/L时，浸杀48 h后钉螺死亡率均 80.0%，其中经柠檬桉和尾叶桉挥发油浸杀的钉螺死亡率均为93.3%；在浓度为10 mg/L时，浸杀48 h钉螺死亡率亦> 60.0%；尾叶桉叶醇提流浸膏及其石油醚萃取物和氯仿萃取物浸杀钉螺48 h的死亡率 65%，其中氯仿萃取物浸杀钉螺死亡率高达95%，且其浓度在10 mg/L时钉螺死亡率也高达60%。结论广东5种桉叶挥发油和尾叶桉的醇提流浸膏均有较好的杀钉螺效果，且尾叶桉醇提流浸膏氯仿萃取物的杀钉螺效果好于其他有机溶剂萃取物。

关键词: 钉螺；杀螺效果；桉树叶；萃取物；筛选