Antifeedant activity of sesquiterpenes from Celastraceae

Forty one sesquiterpenes with a dihydro-beta-agarofuran skeleton, and 14 related synthetic compounds are assayed for antifeedant and insecticidal activities against the Egyptian cotton leafworm Spodoptera littoralis using the leaf disk method. The antifeedant activity is measured in terms of feeding ratio (FRS,) and the insecticidal activity as lethal dose LD100. Thirty eight of the sesquiterpenes assayed show antifeedant activity, including 38 more active then triphenyl tin acetate used as a positive control in this assay. Three sesquiterpenes demonstrate insecticidal activity. Structure activity relations are examined. (C) 1997 Elsevier Science Ltd.