Metabolomic Variability in the Volatile Composition of Essential Oils from Pinus pinea and P. pinaster

In the Mediterranean basin, Pinus pinaster (maritime pine) and P. pinea (stone pine) are highly economically important pine species. These species provide raw material for forest-based industries (e.g., wood, paper, and resin), as well as of other economically relevant products, such as pine nuts (stone pine) and essential oils (EOs). Previous studies described a large genetic and phenotypic intra-species variability that ultimately hinders the comparison between reports. The present work reviews the available literature on P. pinaster and P. pinea EO composition and pinpoints the compounds that showed the highest variation. The chemical profiles of EOs extracted from the aerial parts were obtained from a total of 30 publications. Cluster analysis revealed a higher influence of geographic location on P. pinaster EO composition, than on P. pinea. A high degree of chemical variability was detected for these species. Specifically, the EO components that showed the highest variations were limonene, α-pinene, β-pinene, trans-β-caryophyllene, germacrene D, and β-myrcene for P. pinea, and α-pinene, β-pinene, trans-β-caryophyllene, germacrene D, and β-myrcene for P. pinaster. Thus, it is highly recommended that research performed in field or greenhouse conditions should first ascertain pine chemical variability.