Impact of Geographical Distribution on Chemical Composition and Biological Potential of Juniperus communis L. Essential Oil: A Case Study From Western Himalayas

The current study was focused to assess the impact of geographical distribution (1325-3200 m, asl) on essential oils (EOs) yield, chemical composition, and biological activities of Juniperus communis leaves. Soil mineral content was also analyzed to understand its impact on chemical composition. EO yield variations were observed (0.22%-0.48%), with highest in J. communis collected from Thatri Dhaar (JCTH) (0.48%) sample. Further, refractive index, specific gravity, and optical rotation of EOs revealed notable differences among the samples. Six trace elements in soils were found, with iron being the most abundant at all locations. Total phenolic and flavonoid content indicated significant variations, with highest total phenolic content (TPC) in JCTH (6.100 ± 0.649 mg GAE/g) sample, whereas total flavonoid content (TFC) was in J. communis collected from Mooring (JCM) (1.126 ± 0.004 mgRE/g) sample. GC and GC/MS-based metabolite profiling had shown overall thirty metabolites, including terpenes and monoterpene hydrocarbons. Free radical scavenging assays showed strong antioxidant activity of JCCI and JCTH samples (IC₅₀-ABTS = 4.222 ± 0.166 µg/mL and IC₅₀-DPPH = 3.211 ± 0.307 µg/mL, respectively). Moreover, EOs significantly inhibit α-glucosidase and α-amylase enzymes, Gram-positive and Grnegative bacterial strains. These findings suggested its promising biological potential. Furthermore, identified metabolites-based statistical analysis (principal component analysis [PCA] and hierarchical clustering analysis [HCA]) highlighted similarities and discriminations of geographically impacted samples. This research will be helpful to understand the metabolite composition and their accumulation under different environmental conditions.