Natural product analogs: Stable mimics of aldehyde pheromones

Abstract

AbstractUnder field conditions, the aldehyde components of the pheromones of important lepidopteran and coleopteran pests undergo chemical transformations (oxidation, polymerization, etc.) resulting in behaviorally inactive compounds. In our search for pheromone analogs with favorable chemical and biological properties, a series of nitriles, oximes and isothiocyanates, as novel functional group mimics of some cyclic and long chain pheromones, were prepared and tested. The biological activities of these nitrogen‐containing analogs were studied by electrophysiological and field experiments with three different insect species showing the nitrile analogs to be the most potent mimics, but their activities were lower than those of the natural pheromones. Thus, a 1:1 mixture of pheromone analogs in place of the corresponding natural aldehyde components III and IV elicited dose‐dependent electroantennogram (EAG) responses of antennal preparations of the female boll weevil, Anthonomus grandis. In field trials, the nitrile analogs were poor substituents for the corresponding aldehydes. In EAG experiments with antennal preparations of males of the southwestern corn borer, Diatraea grandiosella, Z11‐16:Nitrile ((Z)‐11‐hexadecenonirile) elicited dose‐dependent responses while single neuron recording from antennal preparations of this species revealed that a neuron responsive to the pheromone component was also stimulated by the mimic Z11‐16:Nitrile. In field experiments, a 97:3 mixture of nitriles Z11‐16:Nitrile and Z9‐16:Nitrile ((Z)‐9‐hexadecenonitrile) effectively attracted males of the cranberry girdler moth, Chrysoteuchia topiaria. © 1993 Wiley‐Liss, Inc.