Phytochemical variability in essential oils of Juniperus communis var. saxatilis populations grow wild in western Himalaya, India

Abstract

Needle and berry samples of Juniperus communis L. var. saxatilis Pall. were sampled separately during post rainy season to comparatively investigate the essential oil (EO) yield and phytochemical variability in eight populations grow wild in western Himalaya, India. The EOs obtained from air-dried needle and berry samples separately by hydrodistillation method using Clevenger type apparatus varied in yield with geographic origin of populations, ranged between 2.5-3.4% and 1.8-2.8% (v/w, dried weight basis), respectively. GC-MS analysis of EO profiles resulted in identification of a total ninety-four phytochemicals, representing over 95% of total oil content. Both, needle as well as berry EO samples were dominated by monoterpene hydrocarbons α-pinene (18.52-30.65% and 14.31-27.37%), D-limonene (17.01-28.96% and 15.80-29.70%), β-myrcene (3.74-5.59% and 4.12-14.23%), followed by sesquiterpene hydrocarbons β-elemene (0.86-4.13% and 0.77-3.65%) and germacrene D (0.27-2.57% and 0.20-6.15%), respectively. The oxygenated sesquiterpenes α-cadinol (0.34-5.90% and to 5.63%) and α-bisabolol (to 3.39 and 0.95-6.71%) constituted the third most abundant group of terpenes while oxidized monoterpenes with α-terpineol (0.73-2.17% and 0.10-3.51%) and α-terpinyl acetate (2.10-4.76% and 0.05-3.54%) were the least dominant group. The principal component and hierarchical cluster analysis indicated that selective local environmental forces driving the microhabitat conditions appeared to be linked to high variability in essential oil composition of different common Juniper populations instead of their geographical proximity. The present study revealed that common Juniper essential oils from western Himalaya, India fulfil minimum requirements of European Pharmacopoeia and warrants its further exploitation as a natural resource of commercial significance for dietary and therapeutic applications.