Detailed 1 H and 13 C NMR structural assignments of four sesquiterpene lactones isolated from Eremanthus elaeagnus (Asteraceae).

A complete 1 H and 13 C NMR analysis for a group of four sesquiterpene lactones isolated from Eremanthus elaeagnus (Asteraceae) is described in this work. 1 H NMR, 13 C {1 H} NMR, gCOSY, gHMQC and gHMBC experiments were performed to provide sufficient structural information to allow an unequivocal assignment. All hydrogen coupling constants were measured, clarifying all hydrogen signal multiplicities.