Chemical Composition and Antibacterial Activity of <i>Rosa villosa</i> subsp. <i>mollis</i> R. Keller &amp; Gams., <i>Rosa hemisphaerica</i> J. Herrm. and Natural Hybrid <i>Rosa ozcelikii</i> Korkmaz &amp; Kandemir Essential Oil

ABSTRACT This study explores the essential oils (EOs) of Rosa hemisphaerica (RH), Rosa villosa subsp. mollis (RV) and the newly identified hybrid Rosa ozcelikii (RO). The major components of the EOs were found to be nonadecane (22.45%), viridiflorol (19.37%) and heneicosane (11.72%) in RH; α ‐muurolene (14.72%), σ ‐cadinene (17.88%) and farnesol (9.94%) in RV; and heptacosane (27.63%), heneicosane (12.42%) and α ‐citronellol (11.90%) in RO. Antibacterial activities were evaluated using the disc diffusion method. The EOs demonstrated moderate antibacterial effects: RV and RH exhibited inhibition zones of 8.0 ± 0.4 mm against Pseudomonas aeruginosa , while RO showed stronger activity with inhibition zones of 11.0 ± 0.5 mm against Staphylococcus aureus , 12.0 ± 0.4 mm against Clostridium perfringens and 9.0 ± 0.5 mm against Bacillus cereus . These findings highlight the chemical diversity and potential therapeutic applications of these Rosa species, emphasising their relevance in the search for natural antimicrobial agents.