Iranian Biology Society Journal of Plant Research (Iranian Journal of Biology) 2383-2592 Articles in Press 2025 11 27 Study of phytochemical properties and biological activity of Teucrium polium in different phonological stages in Chaharmahal va Bakhtiari province Study of phytochemical properties and biological activity of Teucrium polium in different phonological stages in Chaharmahal va Bakhtiari province 2481 10.22034/jpr.2025.8520.3372 FA Fatemeh Malekpoor Department of Biology, Shahrekord Azad University, Shahrekord, Iran 0000-0001-8692-0112 Abdollah Ghasemi Pirbalouti Tehran Islamic Azad University of Medical Sciences, Iran 0000-0002-8376-1854 Hadi Babamir Department of Medicinal Plants, Shahrekord Islamic Azad University, Shahrekord, Iran Journal Article 2024 08 21 Teucrium polium is a medicinal and aromatic plant, belonging to the Lamiaceae family, has many therapeutic effects. The present research was conducted, to investigate the antibacterial and antioxidant activity and phytochemical characteristics of this species in different phenological stages in Chaharmahal and Bakhtiari province. This plant was collected from three heights in Lordegan city, Sate village in three stages before flowering, 50% flowering and 100% flowering. The most important conditions of the region (such as altitude, longitude and latitude) were recorded. From the plant samples collected in three repetitions, essential oil was extracted by water distillation method. Essential oils were chemically analyzed by GC and GC/MS. The antibacterial activity of essential oil was performed using dilution method, and the antioxidant activity performed using the DPPH method. The results of phytochemical analysis showed the most important compounds identified in essential oil of T. polium, as beta-caryophyllene, alpha-humulene, spachunel, caryophyllene oxide. The results obtained from research showed habitat conditions and height difference caused a significant difference in the yield of essential oil as well as the amount of compounds. Also, the results showed that the plant has a better inhibitory activity against Pseudomonas aeruginosa, Escherichia coli, and Klebsiella pneumoniae at the 100% flowering stage. The highest antioxidant capacity is related to the 100% flowering stage. In general, in addition to genetic factors, phenological stages, play a main factor in the amount of secondary compounds of plants and properties essential oil of T. polium. Teucrium polium is a medicinal and aromatic plant, belonging to the Lamiaceae family, has many therapeutic effects. The present research was conducted, to investigate the antibacterial and antioxidant activity and phytochemical characteristics of this species in different phenological stages in Chaharmahal and Bakhtiari province. This plant was collected from three heights in Lordegan city, Sate village in three stages before flowering, 50% flowering and 100% flowering. The most important conditions of the region (such as altitude, longitude and latitude) were recorded. From the plant samples collected in three repetitions, essential oil was extracted by water distillation method. Essential oils were chemically analyzed by GC and GC/MS. The antibacterial activity of essential oil was performed using dilution method, and the antioxidant activity performed using the DPPH method. The results of phytochemical analysis showed the most important compounds identified in essential oil of T. polium, as beta-caryophyllene, alpha-humulene, spachunel, caryophyllene oxide. The results obtained from research showed habitat conditions and height difference caused a significant difference in the yield of essential oil as well as the amount of compounds. Also, the results showed that the plant has a better inhibitory activity against Pseudomonas aeruginosa, Escherichia coli, and Klebsiella pneumoniae at the 100% flowering stage. The highest antioxidant capacity is related to the 100% flowering stage. In general, in addition to genetic factors, phenological stages, play a main factor in the amount of secondary compounds of plants and properties essential oil of T. polium.