报道牵牛子提取物对朱砂叶螨的生物活性。牵牛子石油醚提取物质量浓度为2mg·mL-1时,对朱砂叶螨的雌成螨和卵24h后的校正死亡率分别达到93.7%和77.3%,LC50分别为0.6979和1.3037mg·mL-1;对雌成螨24h后的产卵抑制率和驱避率分别达到82.51%和94.54%。萃取物中石油醚相的活性明显高于甲醇相,质量浓度为2mg·mL-1时,石油醚萃取物对朱砂叶螨的雌成螨和卵24h后的校正死亡率分别达到96.2%和82.1%,LC50分别为0.5042和1.1016mg·mL-1;对石油醚萃取物的柱层析分离最终得到流分12个,其中以第8流分杀螨效果最好,质量浓度为2mg·mL-1时,24h对雌成螨的校正死亡率达96.4%,LC50是0.4477mg·mL-1。
The extractants of semen pharbitidis was investigated for their biological activity against Tetranychus cinnabarinus. Slide-dip and Leaf-residue methods were used to measure the biological activity. Liquid-liquid distribution and the silica gel column were used to separate and purify active components. The results indicated that bioactivity (touch kill, oviposit inhibition, repellency) of petroleum ether extract of semen pharbitidis was higher than that of methanol extract. The adjusted mortalities of female mite and egg were respectively 93.7 % and 77.3 % with treatment of 2 mg·mL^-1 of the petroleum ether extract for 24 h, and their LC50 was 0.697 9 and 1.303 7 mg·mL^-1. And the treatment caused 82.51% and 94.54% of oviposition inhibition and repellency rate. The petroleum ether extract of semen pharbitidis was further separated and purified. The bioactivity of petroleum ether purified extracts of semen pharbitidis was higher with the adjusted mortalities of female mite and egg were 96.2 % and 82.1% ,their LC50 was 0.504 2 and 1.101 6 mg·mL^-1. The silica gel column was used to separate and purify active components of the crude purified extracts of petroleum ether. A total of 12 bands were seen with TLC analysis. The band 8 appeared the strongest acarocidal activity against Tetranychus cinnabarinus, and the adjusted mortalities of female mite was 96.4% at the concentration of 2 mg·mL^-1 , the LC50 was 0.447 7 mg·mL^-1 .