Phytochemical Screening and Evaluation Antibacterial Efficiency of Artemisia and Myrtus communis Leaf Extracts from the Kurdistan Region, Iraq

This study compares the chemical fingerprints and antibacterial activities of 70 % ethanol leaf extracts from Artemisia sp. (S1) and Myrtus communis (S2) collected in Soran District, Kurdistan region, Iraq. Shade-dried leaves were macerated in 70% (v/v) ethanol (1:15 w/v; 4.00 g in 60.0 mL; 72 h) and profiled by untargeted gas chromatography–mass spectrometry and ATR-FTIR. Antibacterial efficacy was evaluated by agar-well diffusion against S. aureus, E. faecalis, E. coli, and P. aeruginosa at 100, 50, and 25 mg mL⁻¹ (50 µL per well; final EtOH ≤ 1 % (v/v); n = 3). Extraction yields were comparable (13.01 ± 0.29 % for S1; 13.38 ± 0.22 % for S2). Chemical fingerprints diverged sharply: S2 was rich in a bicyclic monoterpenol plus two imidazole alkaloids (≈ 46 % TIC), whereas S1 contained a sulfur‑bearing aziridine and azulene sesquiterpenes. Multivariate analysis associated these chemotypes with preferential antibacterial effects. Bioactivity mirrored composition: S2 produced very large zones against E. faecalis (30.7–34.3 mm) and retained Gram-positive potency on dilution, while S1 alone surpassed the 15 mm efficacy benchmark against P. aeruginosa (16.7 ± 0.5 mm at 25 mg mL⁻¹). A viscosity-dependent diffusion effect explained S1’s inverse dose–response. Given the shrubs’ abundance and low cost in Kurdistan, these extracts support Iraq’s One Health strategy and merit fractionation, mode-of-action and safety studies.