High-Resolution Liquid Chromatography-Mass Spectrometry-Based Metabolomics for the Classification of Chuquiraga (Barnadesioideae, Asteraceae): New Phenylpropanoid Derivatives as Chemical Markers for Chuquiraga spinosa .

Despite their relatively poorly investigated phytochemistry, species of the genus are widely commercialized. The present study reports the use of a high-resolution liquid chromatography-mass spectrometry-based metabolomics approach coupled with exploratory and supervised multivariate statistical analyses for species classification and chemical marker identification of four species of (, , , and sp.) from Ecuador and Peru. Based on these analyses, a high percentage of correct classifications (87% to 100%) allowed the prediction of the taxonomic identity of species. Through the metabolite selection process, several key constituents with the potential to be chemical markers were identified. Samples of displayed alkyl glycosides and triterpenoid glycosides as discriminating metabolites, while sp. displayed high concentrations of -hydroxyacetophenone, -hydroxyacetophenone 4--glucoside, -hydroxyacetophenone 4--(6--apiosyl)-glucoside, and quinic acid ester derivatives as the main metabolites. Caffeic acid was characteristic for samples, whereas displayed higher concentrations of the following new phenylpropanoid ester derivatives: 2--caffeoyl-4-hydroxypentanedioic acid (), 2---coumaroyl-4-hydroxypentanedioic acid (), 2--feruloyl-4-hydroxypentanedioic acid (), 2,4--dicaffeoylpentanedioic acid (), and 2--caffeoyl-4--feruloylpentanedioic acid ().