Sesquiterpenoids from Dittrichia viscosa (L.) GREUTER. Their structure and deterrent activity

Abstract

In addition to the earlier described inuviscolide (II), the sesquiterpenic vachanic (V) and 2α-hydroxyisocostic (VII) acids, as well as carabron (VIII) and the so far undescribed sesquiterpenic lactone 11αH,13-dihydroconfertin were also isolated from Dittrichia viscosa (L.) GREUTER. For the last mentioned lactone the structure IX has been derived. The structure of vachanic acid (V) was confirmed by X-ray structural analysis. Compounds V to VII were tested for their deterrent (antifeedant) activity against selected insect pests living in corn stores, and they generally had a high activity.