The Chemical Diversity of Eucalyptus spp. Essential Oils from Plants Grown in Brazil

A chemical analysis of essential oils from leaves of eleven Eucalyptus L'HERIT taxa, grown in Vicosa, Brazil were carried out. The identification and quantification of essential oils constituents were carried out by GC-FID and GC/MS. The leaves of E. camaldulensis and E. tereticornis presented the highest oil content (3.00% and 2.30% respectively). In total, 48 compounds were identified in the oils. Higher levels of 1,8-cineole were found for oils produced by E. microcorys (66.2%), E. urophylla (65.4%) and E. camaldulensis (44.8%) and the hybrid E. urophylla 9 E. grandis (33.0%). The oil from E. saligna was composed mainly by alpha-pinene (92.3%). High concentrations of a-phellandrene were found in the oils produced by E. camaldulensis (22.9%) and E. robusta (36.6%). The oils from E. grandis and E. pilularis were rich in p-cymene (59.5% and 46.0%, respectively). Samples with high levels of 1,8-cineole were classified by principal component analysis (PCA) using the accumulated variance of the PC1 and PC2 into major groups. Other samples were grouped based on their content of p-cymene; alpha-phellandrene, alpha- and beta-eudesmol; alpha-pinene. The PCA allowed the separation and classification of samples with the highest levels of different compounds, a procedure that can help in the decision of grouping oils from different sources for industrial use.