Antifeedant activity of some polygodial derivatives

Polygodial (1) and its derivatives acetal 2 (propylene) and 3 (ethylene) were prepared and their antifeedant activity and toxic effects evaluated on several insect species with different feeding ecologies (Spodoptera littoralis, Leptinotarsa decemlineata, Myzus persicae and Rhopalosiphum padi) along with that of polygonone (4). We also tested their selective cytotoxic effects on insect-derived (Spodoptera frugiperda ovarian Sf9 cells) and mammalian Chinese hamster ovary (CHO) cells. The antifeedant activity of these compounds was consistent with the proposed mode of action for antifeedant drimanes, i. e. adduct formation with amino groups for M. persicae and R. padi (dialdehyde > ketoaldehyde > aldehydeacetal). This was not the case for L. decemlineata, and the cytotoxic effects on insect-derived Sf9 and mammalian CHO cells (aldehydeacetal > dialdehyde > ketoaldehyde).