Antifeedant Activities of Secondary Metabolites from Hyssopus cuspidatus Against Plutella xylostella.

A new sesquiterpene hyssopusin A (1), together with four known compounds 2-5, was isolated from Hyssopus cuspidatus. The structure of hyssopusin A (1) was elucidated by physical and spectroscopic data analysis, including 1D NMR, 2D NMR, and HR-ESI-MS. Compounds 1-4 showed antifeedant effects against the third instar larvae of Plutella xylostella (Lepidoptera: Plutellidae) in a concentration-dependent manner with 50% antifeedant concentrations (AFC50) of 32.17, 38.33, 25.47, and 36.22 μg/cm2, respectively. [ABSTRACT FROM AUTHOR]