Abstract
The leaf oils from Sitka and Engelmann spruce were obtained in 0.36 and 0.094% yield respectively. The average percentage composition was determined by gas–liquid chromatography. Sitka spruce leaf oil was found to contain mainly d-myrcene (23.5%), l-piperitone (23.2%), and d-camphor (17.2%). Smaller amounts of 1,8-cineole, l-β-phellandrene, p-cymene, two aliphatic esters, d-bornyl acetate, d-borneol, and d-terpinen-4-ol were also isolated and several other esters appeared to be present in small amounts. Engelmann spruce leaf oil was found to contain mainly cis-hex-3-en-1-ol (18.5%), d-camphor (16.0%), d-bornyl acetate (8.6%), d-linalool (5.8%), and two unidentified compounds. Smaller amounts of myrcene, β-phellandrene, p-cymene, piperitone, and several sesquiterpenoids were also recorded. Tricyclene, α-pinene, camphene, β-pinene, 3-carene, limonene, γ-terpinene, and terpinolene were found in small amounts in both oils.Phylogenetic relationships between the different spruces and other conifers are discussed.