Antifeedant activity of neo-clerodane diterpenes from Baccharis flabellata Hook & Arn var. flabellata toward Tribolium castaneum Herbst: structure-activity relationships.

In order to establish structure-activity relationships, nine neo-clerodane diterpenes isolated from the acetone extract of aerial parts of Baccharis flabellata Hook & Arn var. fabellata were assayed for antifeedant activity against Tribolium castaneum (Coleoptera: Tenebrionidae). Compounds exhibiting maximal antifeedant activities showed an alpha,beta-unsaturated carbonyl group on the decalin portion and a furan ring at the side chain.