Combination of LC−MS and LC−NMR as a Tool for the Structure Determination of Natural Products

Abstract
Application of both LC−MS and LC−NMR to a partially purified extract of Vernonia fastigiata led to the direct identification of antibacterial sesquiterpene lactones 1−9 without isolation of individual compounds. The rapid structural analysis of both major and minor components of this class of compounds demonstrated the power of structure-guided screening as a complementary method to assay-guided screening.