Species belonging to groups formed in PCA (Fig 1) and HCA (Fig 2).

<p>Species belonging to groups formed in PCA (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0190104#pone.0190104.g001" target="_blank">Fig 1</a>) and HCA (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0190104#pone.0190104.g002" target="_blank">Fig 2</a>).</p

Score scatter plots of principal component analysis (t1 versus t2) of <i>Lychnophora</i> species.

<p>Based on metabolic profiling obtained in LC-MS, in both positive and negative electrospray ionization modes, and in GC-MS. The obtained groups were respectively assigned 3A, 3B, 3C and 3D.</p

Comprehensive untargeted metabolomics of Lychnnophorinae subtribe (Asteraceae: Vernonieae) in a phylogenetic context

<div><p>Members of the subtribe Lychnophorinae occur mostly within the <i>Cerrado</i> domain of the Brazilian Central Plateau. The relationships between its 11 genera, as well as between Lychnophorinae and other subtribes belonging to the tribe Vernonieae, have recently been investigated upon a phylogeny based on molecular and morphological data. We report the use of a comprehensive untargeted metabolomics approach, combining HPLC-MS and GC-MS data, followed by multivariate analyses aiming to assess the congruence between metabolomics data and the phylogenetic hypothesis, as well as its potential as a chemotaxonomic tool. We analyzed 78 species by UHPLC-MS and GC-MS in both positive and negative ionization modes. The metabolic profiles obtained for these species were treated in <i>MetAlign</i> and in <i>MSClust</i> and the matrices generated were used in SIMCA for hierarchical cluster analyses, principal component analyses and orthogonal partial least square discriminant analysis. The results showed that metabolomic analyses are mostly congruent with the phylogenetic hypothesis especially at lower taxonomic levels (<i>Lychnophora</i> or <i>Eremanthus</i>). Our results confirm that data generated using metabolomics provide evidence for chemotaxonomical studies, especially for phylogenetic inference of the Lychnophorinae subtribe and insight into the evolution of the secondary metabolites of this group.</p></div

Score scatter plots of principal component analysis (t1 versus t2) of 78 analyzed species from the Lychnophorinae subtribe.

<p>Based on metabolic profiling obtained in LC-MS, in both positive and negative electrospray ionization modes, and in GC-MS. The obtained groups were respectively assigned 1A, 1B, 1C and 1D.</p

Score scatter plots of principal component analysis (t1 versus t2) of <i>Eremanthus</i> species.

<p>Based on metabolic profiling obtained in LC-MS, in both positive and negative electrospray ionization (ESI) modes, and in GC-MS. The obtained groups were respectively assigned 4A, 4B, 4C and 4D.</p

Identification of discriminant compounds of each group obtained in OPLS-DA of 78 species from the Lychnophorinae subtribe and data taken from UHPLC-MS and UHPLC-HCD MS/MS analyses.

<p>Identification of discriminant compounds of each group obtained in OPLS-DA of 78 species from the Lychnophorinae subtribe and data taken from UHPLC-MS and UHPLC-HCD MS/MS analyses.</p

Hierarchical cluster analysis of 78 analyzed species from the Lychnophorinae subtribe.

<p>Based on metabolic profiling obtained in LC-MS, in both positive and negative electrospray ionization modes, and in GC-MS.</p

Score scatter plots of principal component analysis (PCA1 versus PCA2) of <i>Vernonia</i> species.

<p>Based on untargeted metabolic fingerprints obtained in positive ionization mode.</p

Metabolomics as a Potential Chemotaxonomical Tool: Application in the Genus <i>Vernonia</i> Schreb

<div><p>The taxonomic classification of the genus <i>Vernonia</i> Schreb is complex and, as yet, unclear. We here report the use of untargeted metabolomics approaches, followed by multivariate analyses methods and a phytochemical characterization of ten <i>Vernonia</i> species. Metabolic fingerprints were obtained by accurate mass measurements and used to determine the phytochemical similarities and differences between species through multivariate analyses approaches. Principal component analysis based on the relative levels of 528 metabolites, indicated that the ten species could be clustered into four groups. Thereby, <i>V. polyanthes</i> was the only species with presence of flavones chrysoeriol-7<i>-O</i>-glycuronyl, acacetin-7<i>-O</i>-glycuronyl and sesquiterpenes lactones piptocarphin A and piptocarphin B, while glaucolide A was detected in both <i>V. brasiliana</i> and <i>V. polyanthes</i>, separating these species from the two other species of the <i>Vernonanthura</i> group. Species from the <i>Lessingianthus</i> group were unique in showing a positive response in the foam test, suggesting the presence of saponins, which could be confirmed by metabolite annotation. <i>V. rufogrisea</i> showed a great variety of sesquiterpene lactones, placing this species into a separate group. Species within the <i>Chrysolaena</i> group were unique in accumulating clovamide. Our results of LC-MS-based profiling combined with multivariate analyses suggest that metabolomics approaches, such as untargeted LC-MS, may be potentially used as a large-scale chemotaxonomical tool, in addition to classical morphological and cytotaxonomical approaches, in order to facilitate taxonomical classifications.</p></div

HPLC chromatographic peaks identified in species from <i>Vernonia</i> Schreb.

<p>Species <i>sensu</i> Robinson (1999). A: <i>Vernonanthura brasiliana</i>, B: <i>V. discolor</i>, C: <i>V. ferruginea</i>, D: <i>V. phosphorica</i>, E: <i>Lessingianthus glabratus</i>, F: <i>L. linearifolius</i>, G: <i>L. onoporoides</i>, H: <i>Chrysolaena herbacea</i>, I: <i>C. platensis</i>, J: <i>Lepidaploa rufogrisea</i>. Species <i>sensu</i> Baker (1873): A: <i>Vernonia brasiliana</i>, B: <i>V. discolor</i>, C: <i>V. ferruginea</i>, D: <i>V. phosphorica</i>, E: <i>V. glabrata</i>, F: <i>V. linearifolius</i>, G: <i>V. onopordioides</i>, H: <i>Chrysolaena herbacea</i>, I: <i>V. platensis</i>, J: <i>V. rufogrisea</i>.</p