Structure-activity relationship of isolated avenanthramide alkaloids and synthesized related compounds as oviposition deterrents for Pieris brassicae.

The structure-activity relationship was investigated of compounds isolated from the eggs of Pieris brassicae, the large white cabbage butterfly, and eight synthesized related compounds as oviposition deterrents for this insect. The activity of all compounds was tested in a dual-choice bioassay. The two most active oviposition deterrents for P. brassicae were trans-2- [3-(4-hydroxyphenylpropenoyl)amino]-3,5-dihydroxybenzoic acid [8] and trans-2-[3-(3,4-dihydroxyphenylpropenoyl)amino]-3,5-dihydroxybenzo ic acid [2]. Among members of this compound class, alteration of the substituents of the cinnamic acid part of the molecule affected the oviposition deterrent activity more profoundly than other structural changes. Modification of the anthranilic acid part of the molecule resulted in lower activity.