Variation of Secondary Metabolites (Essential Oils) in Various Plant Organs of Juniperus communis L. Wild Growing in Lithuania

Variation of some secondary metabolites of Juniperus communis among populations as well as at individual plant level was studied. Chemical composition and yield of the essential oils from branches, leaves (needles), sprouts, debarked wood and bark of common juniper collected in Eastern Lithuania was detailed. The oils of ten samples were obtained by hydrodistillation and analyzed by GC and GC-MS. A remarkable variation could be observed in the oil composition and yield depending on plant organs. The yield of the oils varied from 0.06% (v/w, on a dry weight basis) in wood to 0.46% - in the needles. alpha-Pinene was found to be the first major compound in the first-year sprout (43.5-57.1%), needle (31.0-44.7%) and shoot (25.4-46.3%) oils. Essential oil composition of bark and debarked wood differed drastically from oils of the other organs. Bark oil was characterized by predominance of longifolene (25.3-28.8%) and longiborneol (10.8-11.6%), while wood oil contained appreciable quantities of 1-epi-cubenol (up to 10.5%) and delta-cadinene (delta <= 13.4%). Data of J. communis (of Lithuanian origin) essential oils obtained from debarked wood and bark was presented for the first time. Altogether there were identified 160 components (one of them tentatively, 25 ones in quantity more than 3%), which made up 74.3-98.0% of total oil content. The most of the investigated material was characterized by monoterpene hydrocarbon fraction (31.3-72.8%) in the essential oils, with exception for wood and bark, where the main fraction was oxygenated sesquiterpenes. Compounds with pinane and cadinane skeletons predominated in the J. communis essential oils. Additionally, a detailed survey of the previous published data on essential oils from J. communis of Lithuanian origin was presented in the paper.