Nematocidal activity against pine wood nematode of (Bursaphelenchus xylophilus) 7-C-substituted 20-(S)-camptothecins

In an attempt to find the nematocidal activity against Bursaphelenchus xylophilus of 20-(S)-camptothecin derivatives,a series of 7-C-Substituted 20-(S)-camptothecin derivatives were synthesized via a simple modification,and their structures were identified by FT-IR,LC-MS and 1H NMR,among these compounds 14 is a novel compound.The nematocidal activity was tested by the immersion method and the results showed that these compounds exhibited more potent nematocidal activity than 20-(S)-camptothecin especially the compounds 6,9 and 12 which LC50 values were 2.28,2.21 and 1.37 mg/L respectively after 24 h.