Phenolic Profiling of Medicinal Species of Chuquiraga, Asteraceae, by HPLC Fingerprinting

Species of the genus Chuquiraga Juss., Asteraceae, Barnadesioideae, are widely marketed in South America as medicinal plants, despite their relatively uncharacterized phytochemistry. The present study aimed to profile phenolic compounds in commercial samples of three Chuquiraga species (C. jussieui J.F.Gmel., C. spinosa Less., and C. weberbaueri Tovar) from Ecuador and Peru by a high-performance liquid chromatography with diode array detection fingerprinting method combined with multivariate statistical analyses for species classification. From the obtained HPLC fingerprint chromatograms, the traces at 270 nm were selected and submitted to time shifts of peak corrections using the parametric time warping algorithm. Hierarchical clustering analysis, principal components analysis, orthogonal partial least squares discriminant analysis, and k-nearest neighbor measurements were used to evaluate similarities and establish classification models for species discrimination. Based on these analyses, a high percentage of correct classifications (between 83 and 100%) allowed the prediction of the taxonomic identity of unlabeled commercial samples and its geographical origin. Acetophenones (p-hydroxyacetophenone, p-hydroxyacetophenone 4-O-glucoside, p-hydroxyacetophenone 4-O-(6-O-apiosyl)-glucoside), phenylpropanoids (3-O-caffeoylquinic acid, 5-O-caffeoylquinic acid), and flavonoids (quercetin 3-O-rutinoside, quercetin 3-O-glucoronide, kaempferol 3-O-rutinoside) were identified as main constituents of the investigated species. (AU)