Leaf Essential Oil Compositions and Enantiomeric Distributions of Monoterpenoids in Pinus Species: Pinus albicaulis, Pinus flexilis, Pinus lambertiana, Pinus monticola, and Pinus sabiniana

Members of the <i>Pinus</i> genus are well known for their medicinal properties, which can be attributed to their essential oils. In this work, we have examined the leaf essential oils of five understudied <i>Pinus</i> species collected from various locations in western North America. The essential oils were obtained by hydrodistillation and analyzed by gas chromatographic methods, including enantioselective gas chromatography. <i>Pinus albicaulis</i> was dominated by (+)-δ-3-carene; <i>Pinus flexilis</i> was dominated by α-pinene (mostly (+)-α-pinene) and (-)-β-pinene; <i>Pinus lambertiana</i> was dominated by (-)-β-pinene; <i>Pinus monticola</i> was dominated by (-)-β-pinene, (+)-δ-3-carene, and (-)-α-pinene; and <i>Pinus sabiniana</i> was rich in (-)-α-pinene and limonene. While this work adds to our knowledge of <i>Pinus</i> essential oils, additional research is needed to more fully appreciate the geographic and altitudinal variations in the volatile compositions of these <i>Pinus</i> species.