Synthesis and insecticidal activities of novel spin‐labeled derivatives of camptothecin

Abstract

Abstract Continuing our search for natural product based compounds for the control of Brontispa longissima larvae, eight spin‐labeled camptothecin derivatives 7a–h and the intermediate 2 were first tested for their insecticidal activities against fifth‐instar larvae of Brontispa longissima. Among all the tested compounds, especially compounds 7a and 2 showed promising insecticidal activities with the corrected mortality rates of 69.55% and 74.07% against fifth‐instar larvae of B. longissima , respectively. The different insecticidal activity ranges of these compounds indicated that the variation of the structures of l ‐amino acids in these compounds markedly affected the activity profiles of this compound class, and some important SAR information has been revealed from it. © 2011 Wiley Periodicals, Inc. Heteroatom Chem 22:687–691, 2011; View this article online at wileyonlinelibrary.com . DOI 10.1002/hc.20734