Document Type : Research Paper

Authors

• Issa Hakimi Nia ¹
• Mohammad Mahmoudi Soursatani ²
• Gholamreza Abdi ³

¹ 1Department of Horticultural Science, Faculty of Agriculture, Shahid Chamran University of Ahvaz, Ahvaz, Iran

² , Department of Horticultural Science, Faculty of Agriculture, Shahid Chamran University of Ahvaz, Ahvaz, Iran

³ 3Department of Biotechnology, Persian Gulf Research Institute, Persian Gulf University, Bushehr, Iran

Abstract

     Background and objective: Vitex pseudo-negundo, a member of the Lamiaceae family, is valued in traditional medicine for its therapeutic properties and has been used to treat inflammation, pain, and hormonal disorders. Its essential oil contains bioactive compounds such as α-pinene and limonene, which may contribute to its medicinal properties. To investigate the variation in essential oil yield and composition of this valuable plant, 50 populations were collected from natural habitats across 12 provinces of Iran and analyzed.
Methodology: In this study, 50 seed samples of Vitex pseudo-negundo were collected from diverse geographical regions across Iran. The seeds were thoroughly cleaned and dried under shade at ambient temperature (approximately 25–30 °C) for two weeks to preserve their volatile constituents. Essential oils were extracted by hydrodistillation using a Clevenger-type apparatus. For each extraction, 170 g of dried seed powder was placed in a round-bottom flask and mixed with 500 mL of distilled water. The essential oil-containing vapor was condensed and collected in the graduated apparatus tube. The extracted oil was separated from the aqueous phase, dried over anhydrous sodium sulfate to remove residual moisture, and stored in sealed, dark-colored vials at 4 °C until further analysis. Essential oil yield was calculated based on the dry weight of the seeds. For chemical characterization, the essential oil samples were analyzed by gas chromatography–mass spectrometry (GC/MS) using an Agilent 7890A system equipped with an HP-5MS capillary column. Helium was used as a carrier gas at a constant flow rate. Individual compounds were identified by comparing their mass spectra with those in the Wiley and Adams libraries and by calculating and comparing their retention indices with those of a series of n-alkane standards. This approach enabled the identification and characterization of the major and minor volatile constituents in each population.
Results: Essential oil yield varied among the studied populations according to geographical origin, ranging from 0.29% to 0.59%. The highest essential oil yield (0.59%) was recorded in populations from Zarful, Dasht-e Mook, Tang-e Pirzal, and Simareh, whereas the lowest yield (0.29%) was recorded in 13 regions, including Tang-e Abolhayat, Karend, Sardasht, Farashband, Masjed Soleyman, Zeydun, Zeydun Behbahan, Pol-e Keshkan, Shush, Sheykhan, Gachgaran, Bouger, and Sorkheh Dizeh. Analysis of the essential oil composition of V. pseudo-negundo seeds identified eight major compounds, with considerable variation in their relative abundances among populations. These compounds included α-pinene (11.2–28.6%), limonene (4.6–17.6%), terpinyl acetate (1.2–13.2%), α-eudesmol acetate (4.4–10.6%), trans-caryophyllene (2.1–12.6%), β-eudesmol (1.1–8.2%), geranyl linalool (2.4–6.6%), and verbenene (1.5–4.7%). Overall, α-pinene and limonene were the predominant compounds across all populations. In addition, α-eudesmol acetate was consistently detected in most populations at relatively stable concentrations (5–10%). The highest concentrations of this compound were recorded in Pol-e Dokhtar (10.6%) and Lashkar Bolouki (10.2%), whereas the lowest concentration was recorded in Karend toward Sar Pol-e Zahab (4.4%). Trans-caryophyllene was also detected in most samples, with the highest (12.6%) and lowest (2.1%) concentrations recorded in Ghaemiyeh and Kashkoo Village, respectively. Cluster and biplot analyses based on essential oil yield and composition classified the V. pseudo-negundo habitats into five main groups.
Conclusion: The results indicate that both essential oil yield and chemical composition vary among populations and may be influenced by genetic origin, climatic conditions, and other environmental characteristics. Given the relatively high proportion of α-pinene in the essential oil of V. pseudo-negundo, this species may have considerable potential for pharmaceutical, food, and cosmetic applications.

Keywords

• Vitex pseudo-negundo
• α-pinene
• essential oil
• limonene
• monoterpene

Main Subjects

• Phytochemistry (extraction, identification and measurement of active components)