Coriandrum sativum L. is one of the important colinarry herb of Apiaceae family, which widely cultivated in various countries of the world. The aims of this study are to analyze and compare the chemical composition of seed essential oil in several Iranian and Iraqi populations, and their biological activities again some the most important pathogenic bacteria. Therefore, we collected of C. sativum seeds from five localities of Iraq (Baghdad, Diyala, Karbala, Maysan, and Wasit) and four in Iran (Saveh, Lorestan, Urmia, and Dezful). Gas chromatography–mass spectrometry (GC/MS) analysis was employed to characterize the chemical constituents of the essential oils extracted from these seeds. Biological assays are conducted to evaluate the antibacterial activity of the oils against E. coli, S. aureus, an utilizing agar-based testing methodologies. The study reveals diverse chemical profiles in the essential oils, with linalool consistently dominating across all samples. Regional variations are observed, impacting the abundance of compounds such as α-pinene, β-pinene, γ-terpinene, and geranyl acetate. The inhibitory effects of essential oils from different cities on bacteria are closely tied to their distinctive chemical compositions. Linalool, α-Pinene, and γ-Terpinene are key antimicrobial components, with varying quantities in each oil. Baghdad, Dezful, and Wasit oils, rich in Linalool, exhibit robust antibacterial activity. Conversely, Diyala's oil, with limited Terpinen-4-ol, has weaker effects. Karbala's oil, featuring α-Pinene, inhibits effectively. Larestan, Maysan, and Saveh, with Linalool, inhibit different bacteria. Urmia's oil, containing α-Pinene and γ-Terpinene, displays potential, while Wasit's oil, abundant in Linalool and α-Pinene, effectively combats various bacteria.
