Du Yong-Hua, Li Jin-Liang, Jia Ren-Yong, Yin Zhong-Qiong, Li Xu-Ting, Lv Cheng, Ye Gang, Zhang Li, Zhang Yu-Qun
College of Animal Medicine, Sichuan Agricultural University, Ya'an, 625014, PR China.
Vet Parasitol. 2009 Jul 7;163(1-2):175-8. doi: 10.1016/j.vetpar.2009.04.002. Epub 2009 Apr 15.
Four fractions obtained from chloroform extracts of neem (Azadirachta indica) oil by column chromatography were investigated for acaricidal activity against Sarcoptes scabiei var. cuniculi larvae in vitro. Octadecanoic acid-tetrahydrofuran-3,4-diyl ester was isolated from an active fraction of the chloroform extract and its toxicity against S. scabiei larvae was tested in vitro. A complementary log-log model was used to analyse the toxicity data. Activity was found in the third fraction, with 100% corrected mortality after 4.5 h of exposure at a concentration of 200 mg ml(-1). This fraction was repeatedly re-crystallised in acetone to yield a white amorphous powder, identified as octadecanoic acid-tetrahydrofuran-3,4-diyl ester, with a median lethal concentration (LC(50)) of 0.1 mg ml(-1) at 24 h post-treatment. The median lethal time (LT(50)) for this compound was 15.3 h at a concentration of 7.5 mg ml(-1).
对通过柱色谱法从印楝（Azadirachta indica）油的氯仿提取物中获得的四个馏分进行了体外抗兔疥螨（Sarcoptes scabiei var. cuniculi）幼虫杀螨活性研究。从氯仿提取物的活性馏分中分离出十八烷酸 - 四氢呋喃 -3,4 - 二酯，并对其体外抗兔疥螨幼虫的毒性进行了测试。使用互补对数 - 对数模型分析毒性数据。在第三个馏分中发现了活性，在浓度为200 mg ml(-1) 暴露4.5小时后校正死亡率为100%。该馏分在丙酮中反复重结晶，得到一种白色无定形粉末，鉴定为十八烷酸 - 四氢呋喃 -3,4 - 二酯，处理后24小时的半数致死浓度（LC(50)）为0.1 mg ml(-1)。该化合物在浓度为7.5 mg ml(-1) 时的半数致死时间（LT(50)）为15.3小时。
