Structure of two new sesquiterpenoid insect antifeedants from Celastrus rosthornianus

Abstract

Two new sesquiterpene polyol esters have been isolated from the root bark of Celastrus rosthornianus. Their structures were elucidated, on the basis of ¹H NMR, ¹³C NMR, NOESY, ¹H–¹³C chemical-shift correlation, ¹H–¹³C long range correlation (COLOC) and mass spectrometry, as 1β-acetoxy-2β,8β,9α-tribenzoyloxy-4α,6α-dihydroxy-β-dihydroagarofuran 3 and 1β-acetoxy-8β,9α-dibenzoyloxy-2β-(furan-β-carbonyloxy)-4α,6α-dihydroxy-β-dihydroagarofuran 4. The complete assignment of ¹³C NMR chemical shifts of compounds 3 and 4 on the basis of ¹H–¹³C chemicalshift correlation spectral data and insecticidal tests on compound 3 against the larvae of Pieris rapae were also carried out.