Chemical composition and antimicrobial activity of Rosmarinus officinalis L. oils from Sardinia and Corsica

A detailed analysis of Rosmarinus officinalis L. essential oil from Sardinia and Corsica (α-pinene/verbenone/bornyl acetate chemotype) was carried out using GC–RI, GC–MS and 13C-NMR, on the bulk sample or after repeated chromatography. Fifty-eight compounds were identified. The antimicrobial activity of two Sardinian samples was investigated and both exhibited a moderate antibacterial activity. Gram-positive bacteria were more sensitive (MIC 2.5–4 mg/ml) than Gram-negative bacteria. Killing time experiments demonstrated that prolonged times (60 min) are needed to completely inactivate the bacterial inoculum.