Investigating the phytochemical and physiological changes in juniper species is essential for identifying bioactive compounds and enhancing their medicinal uses. A 2022-2023 study evaluated the essential oil content and composition of three juniper species: Juniperus sabina, J. polycarpus, and J. communis. This research was conducted in the Salouk area of North Khorasan, Iran (37° 19.0242' N, 57° 32.7232' E). Herbarium numbers were assigned by the Agricultural Research Center of North Khorasan: J. communis (Khsh.CU/J. communis 101), J. polycarpus (Khsh.CU/J. polycarpus 102), and J. sabina (Khsh.CU/J. sabina 103). Essential oil content per 100 g of dried plant material was 0.5 g for J. polycarpus, 1.7 g for J. sabina, and 0.54 g for J. communis in branches; in fruits, the values were 2.36 g, 3.34 g, and 2.02 g, respectively. J. sabina had a significantly higher essential oil content compared to other species, with 29 compounds in its branches and 24 in its fruits identified through Gas Chromatography-Mass Spectrometry. In contrast, J. polycarpus contained 19 compounds in branches and 36 in fruits. The fruit extracts showed a significantly higher average percentage of essential oil than branch extracts across all species, with the fruit of J. communis containing the highest rate at 98.93%. In the species J. communis, the major compounds in the branch were Trans-pinene (15%), α-phellandrene (14.97%), α-pinene (11.28%) and terpinolene (6.66%) and the major compounds in the fruit were α-phellandrene (22.19%), Hexanoic acid (13.50%), β-pinene (8.93%) and sabinene (7.37%). In the species J. polycarpos, the major compounds in the branch were benzaldehyde (20.03%), δ-3-carene (5.48%) and Terpinolene (3.71%) and the major compounds in the fruit were Thuja-2,4(10)-diene (43.35%), n-heptanol (6.13%) and 1-octen-3-ol (5.40%). In the species J. sabina, the major compounds in the branch were sabinene (12.78%), camphene (12.12%), terpinolene (8.4%) and α-terpinene (6.78%) and the major compounds in the fruit were 1-octen-3-ol (35.27%), α-pinene (7.65%), camphene (5.78%) and Cis-sabinene hydrate (5.15%). This study highlights the potential of ripe fruits in Juniper species as a valuable source of essential oils and emphasizes the critical role of specific genes, particularly the pin gene, in enhancing their biosynthesis. |