Metabolites profiling of five Eucalyptus species by gas chromatography-mass spectrometry and multivariate analysis

An untargeted metabolomic analysis of five Eucalyptus species was used to compare their chemical profiles. Gas chromatography-mass spectrometry (GC-MS) along with multivariate analyses including principal component analysis (PCA) and hierarchical cluster analysis (HCA) were applied to assess variations in the leaf chemical profiles of E. maidenii F. Muell, E. robusta Smith, E. citriodora Hook (syn Corymbia citriodora), E. tereticornis Smith and E. camaldulensis Dehnh. In total, 299 relevant metabolites were identified and subjected to statistical analyses in order to detect either the major common metabolites of the genus or the specific compounds contributing to the characteristic chemical composition of each species. Organic acids, nitrogenous compounds, and phenolic constituents were the main discriminatory groups between the investigated eucalypts. The cluster analysis revealed that fatty acids and fatty alcohols were more concentrated in the leaves of E. citriodora and distinguished it from other species, whereas sugars, polyols, and glycosides were characteristic to E. camaldulensis.