Structural elucidation and absolute configuration of novel β-agarofuran (epoxyeudesmene) sesquiterpenes from Maytenus magellanica(Celastraceae)

Abstract

Six dihydro-β-agarofuran [5,11-epoxy-5β,10α-eudesm-4(14)-ene] sesquiterpenes with a novel substitution pattern were isolated from Maytenus magellanica and their structures were elucidated by means of ¹H and ¹³C NMR spectroscopic studies, including ¹H–¹³C heteronuclear correlation (HETCOR), long range correlation spectra with inverse detection (HMBC) and NOE experiments. Their absolute configurations were determined by application of the CD exciton chirality method while hydrolysis and preparation of derivatives provided additional information. One of the sesquiterpenes exhibited significant antifeedant activity against Spodoptera littoralis.